diff --git a/-Pg11JHzUTo.txt b/-Pg11JHzUTo.txt new file mode 100644 index 0000000000000000000000000000000000000000..3c992c083abaa15f21276c7f8694a80badb5cf8d --- /dev/null +++ b/-Pg11JHzUTo.txt @@ -0,0 +1,14459 @@ +align:start position:0% + +foreign + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so last time we ended on one of these + + align:start position:0% +so last time we ended on one of these + + + align:start position:0% +so last time we ended on one of these +Cliffhangers uh and uh so I rushed you + + align:start position:0% +Cliffhangers uh and uh so I rushed you + + + align:start position:0% +Cliffhangers uh and uh so I rushed you +through a bunch of Japanese data and + + align:start position:0% +through a bunch of Japanese data and + + + align:start position:0% +through a bunch of Japanese data and +then we got to + + align:start position:0% +then we got to + + + align:start position:0% +then we got to +um this new bit of linguistic technology + + align:start position:0% +um this new bit of linguistic technology + + + align:start position:0% +um this new bit of linguistic technology +that's going to be annoying + + align:start position:0% +that's going to be annoying + + + align:start position:0% +that's going to be annoying +um this new bit of linguistic technology + + align:start position:0% +um this new bit of linguistic technology + + + align:start position:0% +um this new bit of linguistic technology +and uh sort of went through it pretty + + align:start position:0% +and uh sort of went through it pretty + + + align:start position:0% +and uh sort of went through it pretty +fast so what I want to do is do the + + align:start position:0% +fast so what I want to do is do the + + + align:start position:0% +fast so what I want to do is do the +run-up to that again a little more + + align:start position:0% +run-up to that again a little more + + + align:start position:0% +run-up to that again a little more +carefully and show you what it is that + + align:start position:0% +carefully and show you what it is that + + + align:start position:0% +carefully and show you what it is that +we're talking about what we were talking + + align:start position:0% +we're talking about what we were talking + + + align:start position:0% +we're talking about what we were talking +about at the end was the position of + + align:start position:0% +about at the end was the position of + + + align:start position:0% +about at the end was the position of +accent and Japanese compounds so here + + align:start position:0% +accent and Japanese compounds so here + + + align:start position:0% +accent and Japanese compounds so here +are a bunch of compound nouns uh in + + align:start position:0% +are a bunch of compound nouns uh in + + + align:start position:0% +are a bunch of compound nouns uh in +Japanese and the observation was that + + align:start position:0% +Japanese and the observation was that + + + align:start position:0% +Japanese and the observation was that +when you have two compound consisting of + + align:start position:0% +when you have two compound consisting of + + + align:start position:0% +when you have two compound consisting of +two parts uh you the result always has + + align:start position:0% +two parts uh you the result always has + + + align:start position:0% +two parts uh you the result always has +one accent it has Accent on one + + align:start position:0% +one accent it has Accent on one + + + align:start position:0% +one accent it has Accent on one +particular syllable + + align:start position:0% +particular syllable + + + align:start position:0% +particular syllable +um the accented syllable doesn't have to + + align:start position:0% +um the accented syllable doesn't have to + + + align:start position:0% +um the accented syllable doesn't have to +be the accented syllable in either of + + align:start position:0% +be the accented syllable in either of + + + align:start position:0% +be the accented syllable in either of +the original you know parts of the + + align:start position:0% +the original you know parts of the + + + align:start position:0% +the original you know parts of the +compounds so like raw egg which is the + + align:start position:0% +compounds so like raw egg which is the + + + align:start position:0% +compounds so like raw egg which is the +first example on this slide + + align:start position:0% +first example on this slide + + + align:start position:0% +first example on this slide +raw and egg uh you know they have + + align:start position:0% +raw and egg uh you know they have + + + align:start position:0% +raw and egg uh you know they have +accents where they have accents raw has + + align:start position:0% +accents where they have accents raw has + + + align:start position:0% +accents where they have accents raw has +an accent on the first syllable egg has + + align:start position:0% +an accent on the first syllable egg has + + + align:start position:0% +an accent on the first syllable egg has +snacks in on the second syllable but raw + + align:start position:0% +snacks in on the second syllable but raw + + + align:start position:0% +snacks in on the second syllable but raw +egg has an accent on the syllable which + + align:start position:0% +egg has an accent on the syllable which + + + align:start position:0% +egg has an accent on the syllable which +is not normally accented in a + + align:start position:0% +is not normally accented in a + + + align:start position:0% +is not normally accented in a +um what we said was you know there is a + + align:start position:0% +um what we said was you know there is a + + + align:start position:0% +um what we said was you know there is a +set of rules for where accent goes in + + align:start position:0% +set of rules for where accent goes in + + + align:start position:0% +set of rules for where accent goes in +these compounds + + align:start position:0% +these compounds + + + align:start position:0% +these compounds +and the rules go something like this uh + + align:start position:0% +and the rules go something like this uh + + + align:start position:0% +and the rules go something like this uh +there's only going to be one accent it + + align:start position:0% +there's only going to be one accent it + + + align:start position:0% +there's only going to be one accent it +needs to be next to the boundary between + + align:start position:0% +needs to be next to the boundary between + + + align:start position:0% +needs to be next to the boundary between +the words + + align:start position:0% +the words + + + align:start position:0% +the words +um and if possible it should be on the + + align:start position:0% +um and if possible it should be on the + + + align:start position:0% +um and if possible it should be on the +second word that is it should be after + + align:start position:0% +second word that is it should be after + + + align:start position:0% +second word that is it should be after +the boundary between the words + + align:start position:0% +the boundary between the words + + + align:start position:0% +the boundary between the words +but you don't do that if that would + + align:start position:0% +but you don't do that if that would + + + align:start position:0% +but you don't do that if that would +result in the accident being on the last + + align:start position:0% +result in the accident being on the last + + + align:start position:0% +result in the accident being on the last +syllable so the sort of General pattern + + align:start position:0% +syllable so the sort of General pattern + + + align:start position:0% +syllable so the sort of General pattern +is the one you're getting in french + + align:start position:0% +is the one you're getting in french + + + align:start position:0% +is the one you're getting in french +fries + + align:start position:0% +fries + + + align:start position:0% +fries +where you get accent at the beginning of + + align:start position:0% +where you get accent at the beginning of + + + align:start position:0% +where you get accent at the beginning of +the second half of the compound potato + + align:start position:0% +the second half of the compound potato + + + align:start position:0% +the second half of the compound potato +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +um that's what you get in most of the + + align:start position:0% +um that's what you get in most of the + + + align:start position:0% +um that's what you get in most of the +examples on the preceding slide if we go + + align:start position:0% +examples on the preceding slide if we go + + + align:start position:0% +examples on the preceding slide if we go +back to the preceding slide you can see + + align:start position:0% +back to the preceding slide you can see + + + align:start position:0% +back to the preceding slide you can see +that in raw egg right it's at the + + align:start position:0% +that in raw egg right it's at the + + + align:start position:0% +that in raw egg right it's at the +beginning of egg you can see it in field + + align:start position:0% +beginning of egg you can see it in field + + + align:start position:0% +beginning of egg you can see it in field +mouse it's at the beginning of mouse and + + align:start position:0% +mouse it's at the beginning of mouse and + + + align:start position:0% +mouse it's at the beginning of mouse and +uh you're also getting it in French fry + + align:start position:0% +uh you're also getting it in French fry + + + align:start position:0% +uh you're also getting it in French fry +but there's this class sort of coherent + + align:start position:0% +but there's this class sort of coherent + + + align:start position:0% +but there's this class sort of coherent +class of exceptions if the second half + + align:start position:0% +class of exceptions if the second half + + + align:start position:0% +class of exceptions if the second half +of the compound is only one syllable + + align:start position:0% +of the compound is only one syllable + + + align:start position:0% +of the compound is only one syllable +long then you don't put accent on the + + align:start position:0% +long then you don't put accent on the + + + align:start position:0% +long then you don't put accent on the +second half you put it at the end of the + + align:start position:0% +second half you put it at the end of the + + + align:start position:0% +second half you put it at the end of the +first half so Kagawa prefecture uh + + align:start position:0% +first half so Kagawa prefecture uh + + + align:start position:0% +first half so Kagawa prefecture uh +Kagawa is uh its name of a place and + + align:start position:0% +Kagawa is uh its name of a place and + + + align:start position:0% +Kagawa is uh its name of a place and +it's got Accent on its first syllable + + align:start position:0% +it's got Accent on its first syllable + + + align:start position:0% +it's got Accent on its first syllable +but the expression for Kagawa prefecture + + align:start position:0% +but the expression for Kagawa prefecture + + + align:start position:0% +but the expression for Kagawa prefecture +has accent at almost at the boundary + + align:start position:0% +has accent at almost at the boundary + + + align:start position:0% +has accent at almost at the boundary +it's right before the boundary between + + align:start position:0% +it's right before the boundary between + + + align:start position:0% +it's right before the boundary between +them not on the second half of the + + align:start position:0% +them not on the second half of the + + + align:start position:0% +them not on the second half of the +compound unusually because the second + + align:start position:0% +compound unusually because the second + + + align:start position:0% +compound unusually because the second +half of the compound is only one + + align:start position:0% +half of the compound is only one + + + align:start position:0% +half of the compound is only one +syllable longs + + align:start position:0% + + + + align:start position:0% + +I'm telling you all this not just to + + align:start position:0% +I'm telling you all this not just to + + + align:start position:0% +I'm telling you all this not just to +educate you in what a cool and + + align:start position:0% +educate you in what a cool and + + + align:start position:0% +educate you in what a cool and +complicated language Japanese is uh but + + align:start position:0% +complicated language Japanese is uh but + + + align:start position:0% +complicated language Japanese is uh but +to show you that there are cases of cool + + align:start position:0% +to show you that there are cases of cool + + + align:start position:0% +to show you that there are cases of cool +and complicated phenomena uh that can be + + align:start position:0% +and complicated phenomena uh that can be + + + align:start position:0% +and complicated phenomena uh that can be +fruitfully thought of as a series of + + align:start position:0% +fruitfully thought of as a series of + + + align:start position:0% +fruitfully thought of as a series of +things that you're trying to do which + + align:start position:0% +things that you're trying to do which + + + align:start position:0% +things that you're trying to do which +are in conflict with each other + + align:start position:0% +are in conflict with each other + + + align:start position:0% +are in conflict with each other +sometimes so Japanese wants the accent + + align:start position:0% +sometimes so Japanese wants the accent + + + align:start position:0% +sometimes so Japanese wants the accent +to be on the second word right and next + + align:start position:0% +to be on the second word right and next + + + align:start position:0% +to be on the second word right and next +to the boundary between the words but it + + align:start position:0% +to the boundary between the words but it + + + align:start position:0% +to the boundary between the words but it +also wants it not to be final + + align:start position:0% +also wants it not to be final + + + align:start position:0% +also wants it not to be final +and if it can't have all of those things + + align:start position:0% +and if it can't have all of those things + + + align:start position:0% +and if it can't have all of those things +at once like in gagawa prefecture it has + + align:start position:0% +at once like in gagawa prefecture it has + + + align:start position:0% +at once like in gagawa prefecture it has +to decide do I care more about it not + + align:start position:0% +to decide do I care more about it not + + + align:start position:0% +to decide do I care more about it not +being final or do I care more about it + + align:start position:0% +being final or do I care more about it + + + align:start position:0% +being final or do I care more about it +being on the second word and Japanese + + align:start position:0% +being on the second word and Japanese + + + align:start position:0% +being on the second word and Japanese +cares more about it not about it uh not + + align:start position:0% +cares more about it not about it uh not + + + align:start position:0% +cares more about it not about it uh not +being final right so it retracts it from + + align:start position:0% +being final right so it retracts it from + + + align:start position:0% +being final right so it retracts it from +the second word to the end of the first + + align:start position:0% +the second word to the end of the first + + + align:start position:0% +the second word to the end of the first +word so this is this case does anybody + + align:start position:0% +word so this is this case does anybody + + + align:start position:0% +word so this is this case does anybody +still read Isaac Asimov had these + + align:start position:0% +still read Isaac Asimov had these + + + align:start position:0% +still read Isaac Asimov had these +stories the robot stories uh I had a + + align:start position:0% +stories the robot stories uh I had a + + + align:start position:0% +stories the robot stories uh I had a +book I Robot it was a series of stories + + align:start position:0% +book I Robot it was a series of stories + + + align:start position:0% +book I Robot it was a series of stories +some of you have heard of them at least + + align:start position:0% +some of you have heard of them at least + + + align:start position:0% +some of you have heard of them at least +yeah so they feature uh robots that uh + + align:start position:0% +yeah so they feature uh robots that uh + + + align:start position:0% +yeah so they feature uh robots that uh +have these laws governing how they work + + align:start position:0% +have these laws governing how they work + + + align:start position:0% +have these laws governing how they work +and the laws act like these kinds of + + align:start position:0% +and the laws act like these kinds of + + + align:start position:0% +and the laws act like these kinds of +laws so there's the first law uh and + + align:start position:0% +laws so there's the first law uh and + + + align:start position:0% +laws so there's the first law uh and +then there's the second law and the rule + + align:start position:0% +then there's the second law and the rule + + + align:start position:0% +then there's the second law and the rule +for the second law is you must obey the + + align:start position:0% +for the second law is you must obey the + + + align:start position:0% +for the second law is you must obey the +second law unless it comes in conflict + + align:start position:0% +second law unless it comes in conflict + + + align:start position:0% +second law unless it comes in conflict +with the first law then you disobey the + + align:start position:0% +with the first law then you disobey the + + + align:start position:0% +with the first law then you disobey the +second law and do the first law right + + align:start position:0% +second law and do the first law right + + + align:start position:0% +second law and do the first law right +and there's a third law which you should + + align:start position:0% +and there's a third law which you should + + + align:start position:0% +and there's a third law which you should +do unless it conflicts with the first or + + align:start position:0% +do unless it conflicts with the first or + + + align:start position:0% +do unless it conflicts with the first or +the second laws uh this is like that + + align:start position:0% +the second laws uh this is like that + + + align:start position:0% +the second laws uh this is like that +right so + + align:start position:0% +right so + + + align:start position:0% +right so +um Japanese wants the accent to be on + + align:start position:0% +um Japanese wants the accent to be on + + + align:start position:0% +um Japanese wants the accent to be on +the second word oh unless that's going + + align:start position:0% +the second word oh unless that's going + + + align:start position:0% +the second word oh unless that's going +to make the accent final then you don't + + align:start position:0% +to make the accent final then you don't + + + align:start position:0% +to make the accent final then you don't +do that + + align:start position:0% +do that + + + align:start position:0% +do that +does that make sense + + align:start position:0% +does that make sense + + + align:start position:0% +does that make sense +uh that's a way + + align:start position:0% +uh that's a way + + + align:start position:0% +uh that's a way +or to put that another way don't put the + + align:start position:0% +or to put that another way don't put the + + + align:start position:0% +or to put that another way don't put the +accent on the last syllable is more + + align:start position:0% +accent on the last syllable is more + + + align:start position:0% +accent on the last syllable is more +important than put the accent on the + + align:start position:0% +important than put the accent on the + + + align:start position:0% +important than put the accent on the +second word that's the picture so you + + align:start position:0% +second word that's the picture so you + + + align:start position:0% +second word that's the picture so you +get + + align:start position:0% +get + + + align:start position:0% +get +um uh Kagawa can with the accent at the + + align:start position:0% +um uh Kagawa can with the accent at the + + + align:start position:0% +um uh Kagawa can with the accent at the +end of Kagawa uh uh and not Kagawa King + + align:start position:0% +end of Kagawa uh uh and not Kagawa King + + + align:start position:0% +end of Kagawa uh uh and not Kagawa King +you know put accent on the at the end + + align:start position:0% +you know put accent on the at the end + + + align:start position:0% +you know put accent on the at the end +um + + align:start position:0% +um + + + align:start position:0% +um +there's a standard way of representing + + align:start position:0% +there's a standard way of representing + + + align:start position:0% +there's a standard way of representing +these kinds of facts these bodies of + + align:start position:0% +these kinds of facts these bodies of + + + align:start position:0% +these kinds of facts these bodies of +facts which involves this table that + + align:start position:0% +facts which involves this table that + + + align:start position:0% +facts which involves this table that +I've got here at the bottom of the uh + + align:start position:0% +I've got here at the bottom of the uh + + + align:start position:0% +I've got here at the bottom of the uh +the slide this was uh is an approach to + + align:start position:0% +the slide this was uh is an approach to + + + align:start position:0% +the slide this was uh is an approach to +phonology that was invented by people uh + + align:start position:0% +phonology that was invented by people uh + + + align:start position:0% +phonology that was invented by people uh +who + + align:start position:0% +who + + + align:start position:0% +who +um one of them in particular Ellen + + align:start position:0% +um one of them in particular Ellen + + + align:start position:0% +um one of them in particular Ellen +Prince is uh brilliant brilliant men but + + align:start position:0% +Prince is uh brilliant brilliant men but + + + align:start position:0% +Prince is uh brilliant brilliant men but +he enjoys intimidating people and so + + align:start position:0% +he enjoys intimidating people and so + + + align:start position:0% +he enjoys intimidating people and so +instead of calling this a table uh he + + align:start position:0% +instead of calling this a table uh he + + + align:start position:0% +instead of calling this a table uh he +decided to call it a tableau so he gives + + align:start position:0% +decided to call it a tableau so he gives + + + align:start position:0% +decided to call it a tableau so he gives +it a French name uh in order to be as + + align:start position:0% +it a French name uh in order to be as + + + align:start position:0% +it a French name uh in order to be as +intimidating as possible + + align:start position:0% +intimidating as possible + + + align:start position:0% +intimidating as possible +um so I'll I'll adopt that because + + align:start position:0% +um so I'll I'll adopt that because + + + align:start position:0% +um so I'll I'll adopt that because +that's what the tactician standard + + align:start position:0% +that's what the tactician standard + + + align:start position:0% +that's what the tactician standard +phonologists uh linguists standardly + + align:start position:0% +phonologists uh linguists standardly + + + align:start position:0% +phonologists uh linguists standardly +call these objects this is a tableau + + align:start position:0% +call these objects this is a tableau + + + align:start position:0% +call these objects this is a tableau +um and what the Tableau represents is + + align:start position:0% +um and what the Tableau represents is + + + align:start position:0% +um and what the Tableau represents is +this kind of interplay between the + + align:start position:0% +this kind of interplay between the + + + align:start position:0% +this kind of interplay between the +different laws that are governing uh + + align:start position:0% +different laws that are governing uh + + + align:start position:0% +different laws that are governing uh +where the accent goes the idea is the + + align:start position:0% +where the accent goes the idea is the + + + align:start position:0% +where the accent goes the idea is the +most important laws are toward the left + + align:start position:0% +most important laws are toward the left + + + align:start position:0% +most important laws are toward the left +and the least important laws are toward + + align:start position:0% +and the least important laws are toward + + + align:start position:0% +and the least important laws are toward +the right and what you do is Imagine + + align:start position:0% +the right and what you do is Imagine + + + align:start position:0% +the right and what you do is Imagine +imagine all of the places where you + + align:start position:0% +imagine all of the places where you + + + align:start position:0% +imagine all of the places where you +could put the accent and you ask + + align:start position:0% +could put the accent and you ask + + + align:start position:0% +could put the accent and you ask +yourself + + align:start position:0% +yourself + + + align:start position:0% +yourself +how does that placement of the accent + + align:start position:0% +how does that placement of the accent + + + align:start position:0% +how does that placement of the accent +you know square with the various + + align:start position:0% +you know square with the various + + + align:start position:0% +you know square with the various +different laws the little asterisks Mark + + align:start position:0% +different laws the little asterisks Mark + + + align:start position:0% +different laws the little asterisks Mark +places where one of the candidates one + + align:start position:0% +places where one of the candidates one + + + align:start position:0% +places where one of the candidates one +of the sort of options you're + + align:start position:0% +of the sort of options you're + + + align:start position:0% +of the sort of options you're +considering violates one of the laws so + + align:start position:0% +considering violates one of the laws so + + + align:start position:0% +considering violates one of the laws so +for example the first one which kept + + align:start position:0% +for example the first one which kept + + + align:start position:0% +for example the first one which kept +both of the Accents in in the parts of + + align:start position:0% +both of the Accents in in the parts of + + + align:start position:0% +both of the Accents in in the parts of +the compound just kept them both + + align:start position:0% +the compound just kept them both + + + align:start position:0% +the compound just kept them both +violates the most important law which is + + align:start position:0% +violates the most important law which is + + + align:start position:0% +violates the most important law which is +you may only have one accent so it gets + + align:start position:0% +you may only have one accent so it gets + + + align:start position:0% +you may only have one accent so it gets +a star right there yeah and that + + align:start position:0% +a star right there yeah and that + + + align:start position:0% +a star right there yeah and that +eliminates that one from competition + + align:start position:0% +eliminates that one from competition + + + align:start position:0% +eliminates that one from competition +because you know it's violated the most + + align:start position:0% +because you know it's violated the most + + + align:start position:0% +because you know it's violated the most +important law the one that's furthest on + + align:start position:0% +important law the one that's furthest on + + + align:start position:0% +important law the one that's furthest on +the left uh and then what what I've done + + align:start position:0% +the left uh and then what what I've done + + + align:start position:0% +the left uh and then what what I've done +is consider examples where the accent is + + align:start position:0% +is consider examples where the accent is + + + align:start position:0% +is consider examples where the accent is +a four-syllable word so we're + + align:start position:0% +a four-syllable word so we're + + + align:start position:0% +a four-syllable word so we're +considering putting the single accent in + + align:start position:0% +considering putting the single accent in + + + align:start position:0% +considering putting the single accent in +on any of the four syllables the first + + align:start position:0% +on any of the four syllables the first + + + align:start position:0% +on any of the four syllables the first +two uh which have the accent on the + + align:start position:0% +two uh which have the accent on the + + + align:start position:0% +two uh which have the accent on the +first or the second syllable violate the + + align:start position:0% +first or the second syllable violate the + + + align:start position:0% +first or the second syllable violate the +second law which says put the accent + + align:start position:0% +second law which says put the accent + + + align:start position:0% +second law which says put the accent +near the boundary between the two halves + + align:start position:0% +near the boundary between the two halves + + + align:start position:0% +near the boundary between the two halves +of the compound so uh those are ones in + + align:start position:0% +of the compound so uh those are ones in + + + align:start position:0% +of the compound so uh those are ones in +which uh the accent is not on a syllable + + align:start position:0% +which uh the accent is not on a syllable + + + align:start position:0% +which uh the accent is not on a syllable +that's next to the boundary + + align:start position:0% +that's next to the boundary + + + align:start position:0% +that's next to the boundary +um and then uh the the next last one + + align:start position:0% +um and then uh the the next last one + + + align:start position:0% +um and then uh the the next last one +which is the one that wins that's the + + align:start position:0% +which is the one that wins that's the + + + align:start position:0% +which is the one that wins that's the +one that obeys all of the conditions + + align:start position:0% +one that obeys all of the conditions + + + align:start position:0% +one that obeys all of the conditions +except for the least important one which + + align:start position:0% +except for the least important one which + + + align:start position:0% +except for the least important one which +is + + align:start position:0% +is + + + align:start position:0% +is +um uh it's best to put your accent on + + align:start position:0% +um uh it's best to put your accent on + + + align:start position:0% +um uh it's best to put your accent on +the last word right right that's not + + align:start position:0% +the last word right right that's not + + + align:start position:0% +the last word right right that's not +there there is no you notice there is no + + align:start position:0% +there there is no you notice there is no + + + align:start position:0% +there there is no you notice there is no +perfect candidate there isn't anything + + align:start position:0% +perfect candidate there isn't anything + + + align:start position:0% +perfect candidate there isn't anything +that doesn't have any stars + + align:start position:0% +that doesn't have any stars + + + align:start position:0% +that doesn't have any stars +um what the Tableau does is allow us to + + align:start position:0% +um what the Tableau does is allow us to + + + align:start position:0% +um what the Tableau does is allow us to +think in a you know formal kind of way + + align:start position:0% +think in a you know formal kind of way + + + align:start position:0% +think in a you know formal kind of way +about uh how you satisfy conditions that + + align:start position:0% +about uh how you satisfy conditions that + + + align:start position:0% +about uh how you satisfy conditions that +are not compatible with each other and I + + align:start position:0% +are not compatible with each other and I + + + align:start position:0% +are not compatible with each other and I +just realized I get to take this off I + + align:start position:0% +just realized I get to take this off I + + + align:start position:0% +just realized I get to take this off I +keep forgetting that + + align:start position:0% +keep forgetting that + + + align:start position:0% +keep forgetting that +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +so that's what the tip low is meant to + + align:start position:0% +so that's what the tip low is meant to + + + align:start position:0% +so that's what the tip low is meant to +represent are there questions about the + + align:start position:0% +represent are there questions about the + + + align:start position:0% +represent are there questions about the +tableau + + align:start position:0% +tableau + + + align:start position:0% +tableau +there's a standard way to represent the + + align:start position:0% +there's a standard way to represent the + + + align:start position:0% +there's a standard way to represent the +fact that the winner is that next last + + align:start position:0% +fact that the winner is that next last + + + align:start position:0% +fact that the winner is that next last +one there where the stress is on the + + align:start position:0% +one there where the stress is on the + + + align:start position:0% +one there where the stress is on the +next last syllable the accent is on the + + align:start position:0% +next last syllable the accent is on the + + + align:start position:0% +next last syllable the accent is on the +next last syllable which is to put a + + align:start position:0% +next last syllable which is to put a + + + align:start position:0% +next last syllable which is to put a +pointing finger next to it like that + + align:start position:0% +pointing finger next to it like that + + + align:start position:0% +pointing finger next to it like that +this is the one that wins + + align:start position:0% +this is the one that wins + + + align:start position:0% +this is the one that wins +optimality Theory this approach to to + + align:start position:0% +optimality Theory this approach to to + + + align:start position:0% +optimality Theory this approach to to +phonology is called optimality Theory + + align:start position:0% +phonology is called optimality Theory + + + align:start position:0% +phonology is called optimality Theory +and uh + + align:start position:0% +and uh + + + align:start position:0% +and uh +um I don't know I guess they just liked + + align:start position:0% +um I don't know I guess they just liked + + + align:start position:0% +um I don't know I guess they just liked +the font that had the pointing finger in + + align:start position:0% +the font that had the pointing finger in + + + align:start position:0% +the font that had the pointing finger in +it so they decided to use it + + align:start position:0% +it so they decided to use it + + + align:start position:0% +it so they decided to use it +okay this is an approach yeah + + align:start position:0% + + + + align:start position:0% + +Oh you mean why am I putting an accent + + align:start position:0% +Oh you mean why am I putting an accent + + + align:start position:0% +Oh you mean why am I putting an accent +on Ken over there + + align:start position:0% + + + + align:start position:0% + +yeah that's a very good point + + align:start position:0% +yeah that's a very good point + + + align:start position:0% +yeah that's a very good point +um it is possible to pronounce Ken by + + align:start position:0% +um it is possible to pronounce Ken by + + + align:start position:0% +um it is possible to pronounce Ken by +itself not as part of a compound so if + + align:start position:0% +itself not as part of a compound so if + + + align:start position:0% +itself not as part of a compound so if +you want to talk about the prefecture + + align:start position:0% +you want to talk about the prefecture + + + align:start position:0% +you want to talk about the prefecture +it's a word it means prefecture so it's + + align:start position:0% +it's a word it means prefecture so it's + + + align:start position:0% +it's a word it means prefecture so it's +which is a sort of kind of like a state + + align:start position:0% +which is a sort of kind of like a state + + + align:start position:0% +which is a sort of kind of like a state +it's an administrative subdivision of + + align:start position:0% +it's an administrative subdivision of + + + align:start position:0% +it's an administrative subdivision of +Japan + + align:start position:0% +Japan + + + align:start position:0% +Japan +um and it's possible to say that word by + + align:start position:0% +um and it's possible to say that word by + + + align:start position:0% +um and it's possible to say that word by +itself + + align:start position:0% +itself + + + align:start position:0% +itself +sorry + + align:start position:0% + + + + align:start position:0% + +it's + + align:start position:0% +it's + + + align:start position:0% +it's +um Ken is + + align:start position:0% +um Ken is + + + align:start position:0% +um Ken is +unbounded I don't think I know what you + + align:start position:0% +unbounded I don't think I know what you + + + align:start position:0% +unbounded I don't think I know what you +mean you could you oh it's not a bound + + align:start position:0% +mean you could you oh it's not a bound + + + align:start position:0% +mean you could you oh it's not a bound +morpheme that's right it can be it can + + align:start position:0% +morpheme that's right it can be it can + + + align:start position:0% +morpheme that's right it can be it can +be a free morphine yes yes that's right + + align:start position:0% +be a free morphine yes yes that's right + + + align:start position:0% +be a free morphine yes yes that's right +so so uh you can say in Japanese you + + align:start position:0% +so so uh you can say in Japanese you + + + align:start position:0% +so so uh you can say in Japanese you +know the the prefecture is large or + + align:start position:0% +know the the prefecture is large or + + + align:start position:0% +know the the prefecture is large or +whatever uh and then you can show that + + align:start position:0% +whatever uh and then you can show that + + + align:start position:0% +whatever uh and then you can show that +it's accented yeah + + align:start position:0% + + + + align:start position:0% + +yeah good question there are other + + align:start position:0% +yeah good question there are other + + + align:start position:0% +yeah good question there are other +questions people have about this + + align:start position:0% +questions people have about this + + + align:start position:0% +questions people have about this +okay so this is just meant to illustrate + + align:start position:0% +okay so this is just meant to illustrate + + + align:start position:0% +okay so this is just meant to illustrate +um the workings of optimality theory + + align:start position:0% +um the workings of optimality theory + + + align:start position:0% +um the workings of optimality theory +um why am i showing you this one + + align:start position:0% +um why am i showing you this one + + + align:start position:0% +um why am i showing you this one +sure + + align:start position:0% +sure + + + align:start position:0% +sure +okay oh I I see this is a similar + + align:start position:0% +okay oh I I see this is a similar + + + align:start position:0% +okay oh I I see this is a similar +Tableau for french fry + + align:start position:0% +Tableau for french fry + + + align:start position:0% +Tableau for french fry +so it says the same uh the same + + align:start position:0% +so it says the same uh the same + + + align:start position:0% +so it says the same uh the same +constraints these things that I put in + + align:start position:0% +constraints these things that I put in + + + align:start position:0% +constraints these things that I put in +in all caps up at the top uh in this + + align:start position:0% +in all caps up at the top uh in this + + + align:start position:0% +in all caps up at the top uh in this +case you do end up with Accent on the at + + align:start position:0% +case you do end up with Accent on the at + + + align:start position:0% +case you do end up with Accent on the at +the beginning of potato on the second + + align:start position:0% +the beginning of potato on the second + + + align:start position:0% +the beginning of potato on the second +word that actually is a perfect + + align:start position:0% +word that actually is a perfect + + + align:start position:0% +word that actually is a perfect +candidate so this is an example in which + + align:start position:0% +candidate so this is an example in which + + + align:start position:0% +candidate so this is an example in which +none of the laws are violated by uh by + + align:start position:0% +none of the laws are violated by uh by + + + align:start position:0% +none of the laws are violated by uh by +the best candidate the laws aren't doing + + align:start position:0% +the best candidate the laws aren't doing + + + align:start position:0% +the best candidate the laws aren't doing +conflict with each other so you can put + + align:start position:0% +conflict with each other so you can put + + + align:start position:0% +conflict with each other so you can put +accent at the beginning of the last word + + align:start position:0% +accent at the beginning of the last word + + + align:start position:0% +accent at the beginning of the last word +and potato and it won't be final yeah + + align:start position:0% + + + + align:start position:0% + +that's absolutely right so if for some + + align:start position:0% +that's absolutely right so if for some + + + align:start position:0% +that's absolutely right so if for some +reason that fourth candidate were + + align:start position:0% +reason that fourth candidate were + + + align:start position:0% +reason that fourth candidate were +impossible say there was another very + + align:start position:0% +impossible say there was another very + + + align:start position:0% +impossible say there was another very +high ranking constraint don't uh don't + + align:start position:0% +high ranking constraint don't uh don't + + + align:start position:0% +high ranking constraint don't uh don't +stress the first don't put accent on + + align:start position:0% +stress the first don't put accent on + + + align:start position:0% +stress the first don't put accent on +potato + + align:start position:0% +potato + + + align:start position:0% +potato +um then yes the third would win that's + + align:start position:0% +um then yes the third would win that's + + + align:start position:0% +um then yes the third would win that's +right and uh actually we can kind of see + + align:start position:0% +right and uh actually we can kind of see + + + align:start position:0% +right and uh actually we can kind of see +that by looking at the behavior of + + align:start position:0% +that by looking at the behavior of + + + align:start position:0% +that by looking at the behavior of +kagawaken so if we eliminate + + align:start position:0% +kagawaken so if we eliminate + + + align:start position:0% +kagawaken so if we eliminate +the option of putting Accent on the last + + align:start position:0% +the option of putting Accent on the last + + + align:start position:0% +the option of putting Accent on the last +word that's where the accent goes It + + align:start position:0% +word that's where the accent goes It + + + align:start position:0% +word that's where the accent goes It +goes at the end of the first word + + align:start position:0% +goes at the end of the first word + + + align:start position:0% +goes at the end of the first word +and so it's the best you can do right uh + + align:start position:0% +and so it's the best you can do right uh + + + align:start position:0% +and so it's the best you can do right uh +still near the boundary still only one + + align:start position:0% +still near the boundary still only one + + + align:start position:0% +still near the boundary still only one +accent uh just didn't manage to Accent + + align:start position:0% +accent uh just didn't manage to Accent + + + align:start position:0% +accent uh just didn't manage to Accent +the last word which is what you'd like + + align:start position:0% +the last word which is what you'd like + + + align:start position:0% +the last word which is what you'd like +to do but it's not high on your list of + + align:start position:0% +to do but it's not high on your list of + + + align:start position:0% +to do but it's not high on your list of +list of constraints yep + + align:start position:0% +list of constraints yep + + + align:start position:0% +list of constraints yep +does that make sense + + align:start position:0% +does that make sense + + + align:start position:0% +does that make sense +so this is an approach to thinking about + + align:start position:0% +so this is an approach to thinking about + + + align:start position:0% +so this is an approach to thinking about +phenology + + align:start position:0% + + + + align:start position:0% + +um optimality theory is the name for it + + align:start position:0% +um optimality theory is the name for it + + + align:start position:0% +um optimality theory is the name for it +it says you know in a way it's a kind of + + align:start position:0% +it says you know in a way it's a kind of + + + align:start position:0% +it says you know in a way it's a kind of +comforting Theory it says do the best + + align:start position:0% +comforting Theory it says do the best + + + align:start position:0% +comforting Theory it says do the best +you can you know you have all of these + + align:start position:0% +you can you know you have all of these + + + align:start position:0% +you can you know you have all of these +things probably all of you have + + align:start position:0% +things probably all of you have + + + align:start position:0% +things probably all of you have +encountered things like this in other + + align:start position:0% +encountered things like this in other + + + align:start position:0% +encountered things like this in other +domains at MIT if you've ever dealt with + + align:start position:0% +domains at MIT if you've ever dealt with + + + align:start position:0% +domains at MIT if you've ever dealt with +engineering problems there are probably + + align:start position:0% +engineering problems there are probably + + + align:start position:0% +engineering problems there are probably +cases where you know you have various + + align:start position:0% +cases where you know you have various + + + align:start position:0% +cases where you know you have various +things that you want to achieve and you + + align:start position:0% +things that you want to achieve and you + + + align:start position:0% +things that you want to achieve and you +can't optimize all of them you have to + + align:start position:0% +can't optimize all of them you have to + + + align:start position:0% +can't optimize all of them you have to +decide which ones are the most important + + align:start position:0% +decide which ones are the most important + + + align:start position:0% +decide which ones are the most important +and the idea here is that language is + + align:start position:0% +and the idea here is that language is + + + align:start position:0% +and the idea here is that language is +like that there are cases where + + align:start position:0% +like that there are cases where + + + align:start position:0% +like that there are cases where +you have to decide among your various uh + + align:start position:0% +you have to decide among your various uh + + + align:start position:0% +you have to decide among your various uh +your various desiderata which ones you + + align:start position:0% +your various desiderata which ones you + + + align:start position:0% +your various desiderata which ones you +care about the most + + align:start position:0% +care about the most + + + align:start position:0% +care about the most +The Hope in optimality theory is that + + align:start position:0% +The Hope in optimality theory is that + + + align:start position:0% +The Hope in optimality theory is that +we'll end up with a list of these + + align:start position:0% +we'll end up with a list of these + + + align:start position:0% +we'll end up with a list of these +constraints these laws these rules uh + + align:start position:0% +constraints these laws these rules uh + + + align:start position:0% +constraints these laws these rules uh +that'll be Universal and the differences + + align:start position:0% +that'll be Universal and the differences + + + align:start position:0% +that'll be Universal and the differences +between languages are just a matter of + + align:start position:0% +between languages are just a matter of + + + align:start position:0% +between languages are just a matter of +deciding what order the different + + align:start position:0% +deciding what order the different + + + align:start position:0% +deciding what order the different +constraints are in you know so that + + align:start position:0% +constraints are in you know so that + + + align:start position:0% +constraints are in you know so that +there could be uh uh languages in which + + align:start position:0% +there could be uh uh languages in which + + + align:start position:0% +there could be uh uh languages in which +you know uh the one accent rule is very + + align:start position:0% +you know uh the one accent rule is very + + + align:start position:0% +you know uh the one accent rule is very +low rank and the first uh the first + + align:start position:0% +low rank and the first uh the first + + + align:start position:0% +low rank and the first uh the first +candidate maybe wins right you could + + align:start position:0% +candidate maybe wins right you could + + + align:start position:0% +candidate maybe wins right you could +imagine a language like that uh Tokyo + + align:start position:0% +imagine a language like that uh Tokyo + + + align:start position:0% +imagine a language like that uh Tokyo +Japanese doesn't work that way yeah so + + align:start position:0% +Japanese doesn't work that way yeah so + + + align:start position:0% +Japanese doesn't work that way yeah so +differences between languages are all a + + align:start position:0% +differences between languages are all a + + + align:start position:0% +differences between languages are all a +matter of re-ranking the constraints + + align:start position:0% +matter of re-ranking the constraints + + + align:start position:0% +matter of re-ranking the constraints +that's sort of the the mission statement + + align:start position:0% +that's sort of the the mission statement + + + align:start position:0% +that's sort of the the mission statement +of optimality theories try to figure out + + align:start position:0% +of optimality theories try to figure out + + + align:start position:0% +of optimality theories try to figure out +how the world could work that way + + align:start position:0% +how the world could work that way + + + align:start position:0% +how the world could work that way +yep + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +um + + align:start position:0% +um + + + align:start position:0% +um +optimality theory was partly inspired by + + align:start position:0% +optimality theory was partly inspired by + + + align:start position:0% +optimality theory was partly inspired by +the discovery of these kinds of + + align:start position:0% +the discovery of these kinds of + + + align:start position:0% +the discovery of these kinds of +conspiracies that we started talking + + align:start position:0% +conspiracies that we started talking + + + align:start position:0% +conspiracies that we started talking +about when I was showing you some stuff + + align:start position:0% +about when I was showing you some stuff + + + align:start position:0% +about when I was showing you some stuff +about yellow money and now we've seen + + align:start position:0% +about yellow money and now we've seen + + + align:start position:0% +about yellow money and now we've seen +another example from Japanese for yellow + + align:start position:0% +another example from Japanese for yellow + + + align:start position:0% +another example from Japanese for yellow +money the conspiracy was uh I don't want + + align:start position:0% +money the conspiracy was uh I don't want + + + align:start position:0% +money the conspiracy was uh I don't want +three consonants in a row and I'll do + + align:start position:0% +three consonants in a row and I'll do + + + align:start position:0% +three consonants in a row and I'll do +various things to achieve that we said + + align:start position:0% +various things to achieve that we said + + + align:start position:0% +various things to achieve that we said +you know you could State rules governing + + align:start position:0% +you know you could State rules governing + + + align:start position:0% +you know you could State rules governing +the various things and maybe in a sense + + align:start position:0% +the various things and maybe in a sense + + + align:start position:0% +the various things and maybe in a sense +you should uh but you sort of the idea + + align:start position:0% +you should uh but you sort of the idea + + + align:start position:0% +you should uh but you sort of the idea +is let's try to keep sight of the fact + + align:start position:0% +is let's try to keep sight of the fact + + + align:start position:0% +is let's try to keep sight of the fact +that all of these rules are trying to + + align:start position:0% +that all of these rules are trying to + + + align:start position:0% +that all of these rules are trying to +achieve the same thing that's we want to + + align:start position:0% +achieve the same thing that's we want to + + + align:start position:0% +achieve the same thing that's we want to +also capture that kind of a fact and + + align:start position:0% +also capture that kind of a fact and + + + align:start position:0% +also capture that kind of a fact and +there's something similar going on here + + align:start position:0% +there's something similar going on here + + + align:start position:0% +there's something similar going on here +in Japanese uh one of the rules the + + align:start position:0% +in Japanese uh one of the rules the + + + align:start position:0% +in Japanese uh one of the rules the +highest ranking rule uh was uh don't + + align:start position:0% +highest ranking rule uh was uh don't + + + align:start position:0% +highest ranking rule uh was uh don't +have more than one accent in word yeah + + align:start position:0% +have more than one accent in word yeah + + + align:start position:0% +have more than one accent in word yeah +and what we saw last time was that there + + align:start position:0% +and what we saw last time was that there + + + align:start position:0% +and what we saw last time was that there +are various things that Japanese does to + + align:start position:0% +are various things that Japanese does to + + + align:start position:0% +are various things that Japanese does to +achieve this depending on the situation + + align:start position:0% +achieve this depending on the situation + + + align:start position:0% +achieve this depending on the situation +so there are + + align:start position:0% +so there are + + + align:start position:0% +so there are +words uh uh like gurai which I think I + + align:start position:0% +words uh uh like gurai which I think I + + + align:start position:0% +words uh uh like gurai which I think I +translated last time is even which are + + align:start position:0% +translated last time is even which are + + + align:start position:0% +translated last time is even which are +accented and if you attach them to + + align:start position:0% +accented and if you attach them to + + + align:start position:0% +accented and if you attach them to +another word that's also accented you + + align:start position:0% +another word that's also accented you + + + align:start position:0% +another word that's also accented you +delete the accent on the first word on + + align:start position:0% +delete the accent on the first word on + + + align:start position:0% +delete the accent on the first word on +the word you're attaching good eye to + + align:start position:0% +the word you're attaching good eye to + + + align:start position:0% +the word you're attaching good eye to +and there are other words like made + + align:start position:0% +and there are other words like made + + + align:start position:0% +and there are other words like made +which means to up to as far as uh which + + align:start position:0% +which means to up to as far as uh which + + + align:start position:0% +which means to up to as far as uh which +are accented but only if they are + + align:start position:0% +are accented but only if they are + + + align:start position:0% +are accented but only if they are +attached to unaccented words + + align:start position:0% +attached to unaccented words + + + align:start position:0% +attached to unaccented words +and then we've done all this talking + + align:start position:0% +and then we've done all this talking + + + align:start position:0% +and then we've done all this talking +about compounds uh these are all + + align:start position:0% +about compounds uh these are all + + + align:start position:0% +about compounds uh these are all +different kinds of examples in which + + align:start position:0% +different kinds of examples in which + + + align:start position:0% +different kinds of examples in which +different things happen there are + + align:start position:0% +different things happen there are + + + align:start position:0% +different things happen there are +different strategies right so for good I + + align:start position:0% +different strategies right so for good I + + + align:start position:0% +different strategies right so for good I +it's delete the accent on the word + + align:start position:0% +it's delete the accent on the word + + + align:start position:0% +it's delete the accent on the word +you've attached good eye to uh for a mad + + align:start position:0% +you've attached good eye to uh for a mad + + + align:start position:0% +you've attached good eye to uh for a mad +it's delete the accent on Monday for the + + align:start position:0% +it's delete the accent on Monday for the + + + align:start position:0% +it's delete the accent on Monday for the +compounds we've now talked about this + + align:start position:0% +compounds we've now talked about this + + + align:start position:0% +compounds we've now talked about this +computation that you go through to try + + align:start position:0% +computation that you go through to try + + + align:start position:0% +computation that you go through to try +to figure out where the single accent + + align:start position:0% +to figure out where the single accent + + + align:start position:0% +to figure out where the single accent +should go but what all of these things + + align:start position:0% +should go but what all of these things + + + align:start position:0% +should go but what all of these things +are doing is trying to arrange for there + + align:start position:0% +are doing is trying to arrange for there + + + align:start position:0% +are doing is trying to arrange for there +to just be a single accent and one of + + align:start position:0% +to just be a single accent and one of + + + align:start position:0% +to just be a single accent and one of +the virtues of optimality theory is that + + align:start position:0% +the virtues of optimality theory is that + + + align:start position:0% +the virtues of optimality theory is that +it allows us to sort of make that part + + align:start position:0% +it allows us to sort of make that part + + + align:start position:0% +it allows us to sort of make that part +of our analysis uh we don't if we just + + align:start position:0% +of our analysis uh we don't if we just + + + align:start position:0% +of our analysis uh we don't if we just +stated these rules we'd be sort of + + align:start position:0% +stated these rules we'd be sort of + + + align:start position:0% +stated these rules we'd be sort of +losing sight of the fact that these + + align:start position:0% +losing sight of the fact that these + + + align:start position:0% +losing sight of the fact that these +rules all seem to be trying to achieve + + align:start position:0% +rules all seem to be trying to achieve + + + align:start position:0% +rules all seem to be trying to achieve +the same thing + + align:start position:0% +the same thing + + + align:start position:0% +the same thing +things people who work on optimality + + align:start position:0% +things people who work on optimality + + + align:start position:0% +things people who work on optimality +Theory are trying to get and then of + + align:start position:0% +Theory are trying to get and then of + + + align:start position:0% +Theory are trying to get and then of +course the goal is to try to understand + + align:start position:0% +course the goal is to try to understand + + + align:start position:0% +course the goal is to try to understand +why we have the constraints that we have + + align:start position:0% +why we have the constraints that we have + + + align:start position:0% +why we have the constraints that we have +and not others it's another kind of + + align:start position:0% +and not others it's another kind of + + + align:start position:0% +and not others it's another kind of +thing people who work on this try to do + + align:start position:0% + + + + align:start position:0% + +uh yes I just said that + + align:start position:0% +uh yes I just said that + + + align:start position:0% +uh yes I just said that +and that so remember yellow money which + + align:start position:0% +and that so remember yellow money which + + + align:start position:0% +and that so remember yellow money which +was avoid strings of three consonants + + align:start position:0% +was avoid strings of three consonants + + + align:start position:0% +was avoid strings of three consonants +either by inserting vowels or by + + align:start position:0% +either by inserting vowels or by + + + align:start position:0% +either by inserting vowels or by +deleting H if you have an H + + align:start position:0% +deleting H if you have an H + + + align:start position:0% +deleting H if you have an H +um so uh + + align:start position:0% +um so uh + + + align:start position:0% +um so uh +I've been saying we could just State + + align:start position:0% +I've been saying we could just State + + + align:start position:0% +I've been saying we could just State +these rules but we'd be missing a + + align:start position:0% +these rules but we'd be missing a + + + align:start position:0% +these rules but we'd be missing a +generalization yellow money is trying to + + align:start position:0% +generalization yellow money is trying to + + + align:start position:0% +generalization yellow money is trying to +avoid three constants in a row Japanese + + align:start position:0% +avoid three constants in a row Japanese + + + align:start position:0% +avoid three constants in a row Japanese +is trying to avoid two Accents in a + + align:start position:0% +is trying to avoid two Accents in a + + + align:start position:0% +is trying to avoid two Accents in a +single word + + align:start position:0% +single word + + + align:start position:0% +single word +um uh maybe it's obvious we don't want + + align:start position:0% +um uh maybe it's obvious we don't want + + + align:start position:0% +um uh maybe it's obvious we don't want +to miss generalizations like that we + + align:start position:0% +to miss generalizations like that we + + + align:start position:0% +to miss generalizations like that we +want to find them and understand them + + align:start position:0% +want to find them and understand them + + + align:start position:0% +want to find them and understand them +um + + align:start position:0% +um + + + align:start position:0% +um +so similar kind of thing that we could + + align:start position:0% +so similar kind of thing that we could + + + align:start position:0% +so similar kind of thing that we could +think about here uh we've talked now a + + align:start position:0% +think about here uh we've talked now a + + + align:start position:0% +think about here uh we've talked now a +couple of times about Polish Polish is + + align:start position:0% +couple of times about Polish Polish is + + + align:start position:0% +couple of times about Polish Polish is +one of a number of languages in which uh + + align:start position:0% +one of a number of languages in which uh + + + align:start position:0% +one of a number of languages in which uh +if you have certain kinds of consonants + + align:start position:0% +if you have certain kinds of consonants + + + align:start position:0% +if you have certain kinds of consonants +at the ends of words uh consonants like + + align:start position:0% +at the ends of words uh consonants like + + + align:start position:0% +at the ends of words uh consonants like +B and D and G and Z we convinced + + align:start position:0% +B and D and G and Z we convinced + + + align:start position:0% +B and D and G and Z we convinced +ourselves that they devoice they become + + align:start position:0% +ourselves that they devoice they become + + + align:start position:0% +ourselves that they devoice they become +voiceless at the ends of words that + + align:start position:0% +voiceless at the ends of words that + + + align:start position:0% +voiceless at the ends of words that +allows us to capture various kinds of + + align:start position:0% +allows us to capture various kinds of + + + align:start position:0% +allows us to capture various kinds of +facts about what happens to polish words + + align:start position:0% +facts about what happens to polish words + + + align:start position:0% +facts about what happens to polish words +when they become plural namely but words + + align:start position:0% +when they become plural namely but words + + + align:start position:0% +when they become plural namely but words +that sound voiceless sound consonants + + align:start position:0% +that sound voiceless sound consonants + + + align:start position:0% +that sound voiceless sound consonants +that sound voiceless when they're at the + + align:start position:0% +that sound voiceless when they're at the + + + align:start position:0% +that sound voiceless when they're at the +ends of words uh become voiced sometimes + + align:start position:0% +ends of words uh become voiced sometimes + + + align:start position:0% +ends of words uh become voiced sometimes +when they're no longer at the end of + + align:start position:0% +when they're no longer at the end of + + + align:start position:0% +when they're no longer at the end of +words we decided that's because they're + + align:start position:0% +words we decided that's because they're + + + align:start position:0% +words we decided that's because they're +underlying the uh voiced and they they + + align:start position:0% +underlying the uh voiced and they they + + + align:start position:0% +underlying the uh voiced and they they +devoice when they're at the ends of + + align:start position:0% +devoice when they're at the ends of + + + align:start position:0% +devoice when they're at the ends of +words + + align:start position:0% +words + + + align:start position:0% +words +now so right this is all kind of + + align:start position:0% +now so right this is all kind of + + + align:start position:0% +now so right this is all kind of +familiar you all remember polish yeah + + align:start position:0% +familiar you all remember polish yeah + + + align:start position:0% +familiar you all remember polish yeah +it's not just polish there are lots of + + align:start position:0% +it's not just polish there are lots of + + + align:start position:0% +it's not just polish there are lots of +languages that do this + + align:start position:0% +languages that do this + + + align:start position:0% +languages that do this +um + + align:start position:0% +um + + + align:start position:0% +um +uh and so what I'm inviting you to do at + + align:start position:0% +uh and so what I'm inviting you to do at + + + align:start position:0% +uh and so what I'm inviting you to do at +the end of this slide is to imagine two + + align:start position:0% +the end of this slide is to imagine two + + + align:start position:0% +the end of this slide is to imagine two +kinds of stories about polish one that + + align:start position:0% +kinds of stories about polish one that + + + align:start position:0% +kinds of stories about polish one that +would say yeah final consonants the + + align:start position:0% +would say yeah final consonants the + + + align:start position:0% +would say yeah final consonants the +voice in Polish and another that would + + align:start position:0% +voice in Polish and another that would + + + align:start position:0% +voice in Polish and another that would +say well there are four rules actually + + align:start position:0% +say well there are four rules actually + + + align:start position:0% +say well there are four rules actually +there's a rule that says b d voices when + + align:start position:0% +there's a rule that says b d voices when + + + align:start position:0% +there's a rule that says b d voices when +it's final and a rule that says d d + + align:start position:0% +it's final and a rule that says d d + + + align:start position:0% +it's final and a rule that says d d +voices when it's final and a rule that + + align:start position:0% +voices when it's final and a rule that + + + align:start position:0% +voices when it's final and a rule that +says G devices yeah + + align:start position:0% +says G devices yeah + + + align:start position:0% +says G devices yeah +both of those would capture all of the + + align:start position:0% +both of those would capture all of the + + + align:start position:0% +both of those would capture all of the +Polish facts one of them is clearly + + align:start position:0% +Polish facts one of them is clearly + + + align:start position:0% +Polish facts one of them is clearly +better yeah uh so we want to understand + + align:start position:0% +better yeah uh so we want to understand + + + align:start position:0% +better yeah uh so we want to understand +why we get the particular phenomena that + + align:start position:0% +why we get the particular phenomena that + + + align:start position:0% +why we get the particular phenomena that +we do in Polish is it clear to everybody + + align:start position:0% +we do in Polish is it clear to everybody + + + align:start position:0% +we do in Polish is it clear to everybody +that that's that it would be better to + + align:start position:0% +that that's that it would be better to + + + align:start position:0% +that that's that it would be better to +do things that way + + align:start position:0% +do things that way + + + align:start position:0% +do things that way +and what we're doing here is uh sort of + + align:start position:0% +and what we're doing here is uh sort of + + + align:start position:0% +and what we're doing here is uh sort of +similar + + align:start position:0% +similar + + + align:start position:0% +similar +why would it be better + + align:start position:0% + + + + align:start position:0% + +what would be wrong why why is it better + + align:start position:0% +what would be wrong why why is it better + + + align:start position:0% +what would be wrong why why is it better +to be able to say final continent is The + + align:start position:0% +to be able to say final continent is The + + + align:start position:0% +to be able to say final continent is The +Voice + + align:start position:0% +Voice + + + align:start position:0% +Voice +than to say + + align:start position:0% +than to say + + + align:start position:0% +than to say +well we have these four rules yeah + + align:start position:0% + + + + align:start position:0% + +yeah so it might make it easier to make + + align:start position:0% +yeah so it might make it easier to make + + + align:start position:0% +yeah so it might make it easier to make +cross-linguistic comparisons so yeah + + align:start position:0% +cross-linguistic comparisons so yeah + + + align:start position:0% +cross-linguistic comparisons so yeah +that's a very good point yeah + + align:start position:0% +that's a very good point yeah + + + align:start position:0% +that's a very good point yeah +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +yeah + + align:start position:0% + + + + align:start position:0% + +we also maybe + + align:start position:0% +we also maybe + + + align:start position:0% +we also maybe +I don't know if this is a good way to + + align:start position:0% +I don't know if this is a good way to + + + align:start position:0% +I don't know if this is a good way to +say it maybe it is + + align:start position:0% +say it maybe it is + + + align:start position:0% +say it maybe it is +we want to understand why + + align:start position:0% +we want to understand why + + + align:start position:0% +we want to understand why +the sounds that become voiceless at the + + align:start position:0% +the sounds that become voiceless at the + + + align:start position:0% +the sounds that become voiceless at the +ends of words in Polish are bdg and z + + align:start position:0% +ends of words in Polish are bdg and z + + + align:start position:0% +ends of words in Polish are bdg and z +and not b d a and o right + + align:start position:0% +and not b d a and o right + + + align:start position:0% +and not b d a and o right +um + + align:start position:0% +um + + + align:start position:0% +um +if we're just making four rules for + + align:start position:0% +if we're just making four rules for + + + align:start position:0% +if we're just making four rules for +those four letters then uh it's not + + align:start position:0% +those four letters then uh it's not + + + align:start position:0% +those four letters then uh it's not +clear there's no reason why one of those + + align:start position:0% +clear there's no reason why one of those + + + align:start position:0% +clear there's no reason why one of those +rules is more natural than the other but + + align:start position:0% +rules is more natural than the other but + + + align:start position:0% +rules is more natural than the other but +as I keep saying + + align:start position:0% +as I keep saying + + + align:start position:0% +as I keep saying +What's Happening Here in Polish is + + align:start position:0% +What's Happening Here in Polish is + + + align:start position:0% +What's Happening Here in Polish is +extremely common uh so you get it in + + align:start position:0% +extremely common uh so you get it in + + + align:start position:0% +extremely common uh so you get it in +Turkish you get it in Russian you get it + + align:start position:0% +Turkish you get it in Russian you get it + + + align:start position:0% +Turkish you get it in Russian you get it +in a bunch of different languages German + + align:start position:0% +in a bunch of different languages German + + + align:start position:0% +in a bunch of different languages German +um and so we want to understand why it's + + align:start position:0% +um and so we want to understand why it's + + + align:start position:0% +um and so we want to understand why it's +common and part of understanding why + + align:start position:0% +common and part of understanding why + + + align:start position:0% +common and part of understanding why +it's common is being able to say that + + align:start position:0% +it's common is being able to say that + + + align:start position:0% +it's common is being able to say that +that's a common rule a standard rule + + align:start position:0% +that's a common rule a standard rule + + + align:start position:0% +that's a common rule a standard rule +that we see all over the place and then + + align:start position:0% +that we see all over the place and then + + + align:start position:0% +that we see all over the place and then +we can get to work on understanding it + + align:start position:0% +we can get to work on understanding it + + + align:start position:0% +we can get to work on understanding it +if we just have these four rules then + + align:start position:0% +if we just have these four rules then + + + align:start position:0% +if we just have these four rules then +it's unclear why those four rules are so + + align:start position:0% +it's unclear why those four rules are so + + + align:start position:0% +it's unclear why those four rules are so +common whereas uh b d a and o d voice at + + align:start position:0% +common whereas uh b d a and o d voice at + + + align:start position:0% +common whereas uh b d a and o d voice at +the ends of words is not at all common I + + align:start position:0% +the ends of words is not at all common I + + + align:start position:0% +the ends of words is not at all common I +don't know of any languages that do that + + align:start position:0% +don't know of any languages that do that + + + align:start position:0% +don't know of any languages that do that +that makes sense that's another sense in + + align:start position:0% +that makes sense that's another sense in + + + align:start position:0% +that makes sense that's another sense in +which yeah making generalizations is + + align:start position:0% +which yeah making generalizations is + + + align:start position:0% +which yeah making generalizations is +good this is this is becoming a + + align:start position:0% +good this is this is becoming a + + + align:start position:0% +good this is this is becoming a +philosophy of science question yeah it's + + align:start position:0% +philosophy of science question yeah it's + + + align:start position:0% +philosophy of science question yeah it's +like you know why why is science good + + align:start position:0% +like you know why why is science good + + + align:start position:0% +like you know why why is science good +why is it good to make generalizations + + align:start position:0% +why is it good to make generalizations + + + align:start position:0% +why is it good to make generalizations +um because it helps us to understand the + + align:start position:0% +um because it helps us to understand the + + + align:start position:0% +um because it helps us to understand the +world we're all better for Faith's + + align:start position:0% +world we're all better for Faith's + + + align:start position:0% +world we're all better for Faith's +reason as well as the reason I just + + align:start position:0% +reason as well as the reason I just + + + align:start position:0% +reason as well as the reason I just +offered yeah + + align:start position:0% + + + + align:start position:0% + +it's um yeah + + align:start position:0% +it's um yeah + + + align:start position:0% +it's um yeah +yes arguably so there are languages that + + align:start position:0% +yes arguably so there are languages that + + + align:start position:0% +yes arguably so there are languages that +D voice vowels + + align:start position:0% +D voice vowels + + + align:start position:0% +D voice vowels +um + + align:start position:0% +um + + + align:start position:0% +um +uh mokalis is one no Japanese is another + + align:start position:0% +uh mokalis is one no Japanese is another + + + align:start position:0% +uh mokalis is one no Japanese is another +um so Japanese has a general rule + + align:start position:0% +um so Japanese has a general rule + + + align:start position:0% +um so Japanese has a general rule +devoicing + + align:start position:0% +devoicing + + + align:start position:0% +devoicing +um it's High vowels + + align:start position:0% +um it's High vowels + + + align:start position:0% +um it's High vowels +when they are + + align:start position:0% +when they are + + + align:start position:0% +when they are +between voiceless consonants I guess so + + align:start position:0% +between voiceless consonants I guess so + + + align:start position:0% +between voiceless consonants I guess so +uh here's the Japanese word for like and + + align:start position:0% +uh here's the Japanese word for like and + + + align:start position:0% +uh here's the Japanese word for like and +it's pronounced ski ski so the uh isn't + + align:start position:0% +it's pronounced ski ski so the uh isn't + + + align:start position:0% +it's pronounced ski ski so the uh isn't +proud you can't you don't say Suki + + align:start position:0% +proud you can't you don't say Suki + + + align:start position:0% +proud you can't you don't say Suki +unless you're being very slow and + + align:start position:0% +unless you're being very slow and + + + align:start position:0% +unless you're being very slow and +careful + + align:start position:0% +careful + + + align:start position:0% +careful +and uh it's still a vowel in the sense + + align:start position:0% +and uh it's still a vowel in the sense + + + align:start position:0% +and uh it's still a vowel in the sense +that your tongue and the rest of your + + align:start position:0% +that your tongue and the rest of your + + + align:start position:0% +that your tongue and the rest of your +vocal tract is still in the + + align:start position:0% +vocal tract is still in the + + + align:start position:0% +vocal tract is still in the +configuration that it would be if your + + align:start position:0% +configuration that it would be if your + + + align:start position:0% +configuration that it would be if your +vocal cords were vibrating but they + + align:start position:0% +vocal cords were vibrating but they + + + align:start position:0% +vocal cords were vibrating but they +aren't yeah so so yeah they're arguably + + align:start position:0% +aren't yeah so so yeah they're arguably + + + align:start position:0% +aren't yeah so so yeah they're arguably +are voiceless vaults yeah yes Joseph + + align:start position:0% + + + + align:start position:0% + +oh + + align:start position:0% +oh + + + align:start position:0% +oh +um so in this particular example there + + align:start position:0% +um so in this particular example there + + + align:start position:0% +um so in this particular example there +aren't any affixes you can add to ski to + + align:start position:0% +aren't any affixes you can add to ski to + + + align:start position:0% +aren't any affixes you can add to ski to +to devoice the vowel + + align:start position:0% +to devoice the vowel + + + align:start position:0% +to devoice the vowel +um but uh + + align:start position:0% +um but uh + + + align:start position:0% +um but uh +um let me think of a of an example + + align:start position:0% +um let me think of a of an example + + + align:start position:0% +um let me think of a of an example +uh + + align:start position:0% +uh + + + align:start position:0% +uh +yeah so + + align:start position:0% +yeah so + + + align:start position:0% +yeah so +um + + align:start position:0% +um + + + align:start position:0% +um +uh + + align:start position:0% +uh + + + align:start position:0% +uh +Tatsu + + align:start position:0% +Tatsu + + + align:start position:0% +Tatsu +um so this is not high so it doesn't + + align:start position:0% +um so this is not high so it doesn't + + + align:start position:0% +um so this is not high so it doesn't +devoice this is the verb to stand + + align:start position:0% +devoice this is the verb to stand + + + align:start position:0% +devoice this is the verb to stand +um the more polite version of this + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% + + + + align:start position:0% + +let me try to think of an example let me + + align:start position:0% +let me try to think of an example let me + + + align:start position:0% +let me try to think of an example let me +try to think of an example that does + + align:start position:0% +try to think of an example that does + + + align:start position:0% +try to think of an example that does +what you want but there aren't any + + align:start position:0% +what you want but there aren't any + + + align:start position:0% +what you want but there aren't any +examples that will work with ski yeah + + align:start position:0% +examples that will work with ski yeah + + + align:start position:0% +examples that will work with ski yeah +um + + align:start position:0% +um + + + align:start position:0% +um +uh + + align:start position:0% +uh + + + align:start position:0% +uh +okay so when I think of an example at + + align:start position:0% +okay so when I think of an example at + + + align:start position:0% +okay so when I think of an example at +three in the morning I'll give you a + + align:start position:0% +three in the morning I'll give you a + + + align:start position:0% +three in the morning I'll give you a +call leave me your phone number and uh + + align:start position:0% +call leave me your phone number and uh + + + align:start position:0% +call leave me your phone number and uh +think of that + + align:start position:0% +think of that + + + align:start position:0% +think of that +it's got to be a straightforward way to + + align:start position:0% +it's got to be a straightforward way to + + + align:start position:0% +it's got to be a straightforward way to +do this it's going to bother me now uh + + align:start position:0% +do this it's going to bother me now uh + + + align:start position:0% +do this it's going to bother me now uh +yeah other questions about this + + align:start position:0% + + + + align:start position:0% + +ah + + align:start position:0% +ah + + + align:start position:0% +ah +try to think of questions while I tried + + align:start position:0% +try to think of questions while I tried + + + align:start position:0% +try to think of questions while I tried +to think of examples that do what Joseph + + align:start position:0% +to think of examples that do what Joseph + + + align:start position:0% +to think of examples that do what Joseph +wants because the past tense suffix in + + align:start position:0% +wants because the past tense suffix in + + + align:start position:0% +wants because the past tense suffix in +Japanese oh oh + + align:start position:0% +Japanese oh oh + + + align:start position:0% +Japanese oh oh +yeah yeah okay here's one + + align:start position:0% +yeah yeah okay here's one + + + align:start position:0% +yeah yeah okay here's one +um uh uh adjectives in Japanese + + align:start position:0% + + + + align:start position:0% + +so this is the the word for new + + align:start position:0% +so this is the the word for new + + + align:start position:0% +so this is the the word for new +atarashi + + align:start position:0% +atarashi + + + align:start position:0% +atarashi +um and uh + + align:start position:0% +um and uh + + + align:start position:0% +um and uh +negative of it + + align:start position:0% + + + + align:start position:0% + +and I + + align:start position:0% +and I + + + align:start position:0% +and I +uh and so there's a coup that you add to + + align:start position:0% +uh and so there's a coup that you add to + + + align:start position:0% +uh and so there's a coup that you add to +make the negative form + + align:start position:0% +make the negative form + + + align:start position:0% +make the negative form +um and it ends up putting this vowel + + align:start position:0% +um and it ends up putting this vowel + + + align:start position:0% +um and it ends up putting this vowel +between bracelets between voiceless + + align:start position:0% +between bracelets between voiceless + + + align:start position:0% +between bracelets between voiceless +sounds and then yeah City voices so it + + align:start position:0% +sounds and then yeah City voices so it + + + align:start position:0% +sounds and then yeah City voices so it +goes from atarashi to uh + + align:start position:0% + + + + align:start position:0% + +uh or the past tense actually so it was + + align:start position:0% +uh or the past tense actually so it was + + + align:start position:0% +uh or the past tense actually so it was +if you want to say something was new + + align:start position:0% +if you want to say something was new + + + align:start position:0% +if you want to say something was new +it's + + align:start position:0% + + + + align:start position:0% + +again the e that's after the voices + + align:start position:0% +again the e that's after the voices + + + align:start position:0% +again the e that's after the voices +because there's a voiceless sound good + + align:start position:0% +because there's a voiceless sound good + + + align:start position:0% +because there's a voiceless sound good +now I won't call you at two in the + + align:start position:0% +now I won't call you at two in the + + + align:start position:0% +now I won't call you at two in the +morning + + align:start position:0% +morning + + + align:start position:0% +morning +any other questions about this + + align:start position:0% + + + + align:start position:0% + +uh okay + + align:start position:0% +uh okay + + + align:start position:0% +uh okay +so + + align:start position:0% +so + + + align:start position:0% +so +um + + align:start position:0% +um + + + align:start position:0% +um +let's go back now to the English plural + + align:start position:0% +let's go back now to the English plural + + + align:start position:0% +let's go back now to the English plural +suffix + + align:start position:0% +suffix + + + align:start position:0% +suffix +um and kind of uh review something that + + align:start position:0% +um and kind of uh review something that + + + align:start position:0% +um and kind of uh review something that +we have talked about but in the in the + + align:start position:0% +we have talked about but in the in the + + + align:start position:0% +we have talked about but in the in the +light of all of the things that we've + + align:start position:0% +light of all of the things that we've + + + align:start position:0% +light of all of the things that we've +talked about since then I hope + + align:start position:0% +talked about since then I hope + + + align:start position:0% +talked about since then I hope +it'll become a little clearer so again + + align:start position:0% +it'll become a little clearer so again + + + align:start position:0% +it'll become a little clearer so again +we're talking about the regular English + + align:start position:0% +we're talking about the regular English + + + align:start position:0% +we're talking about the regular English +plural suffix stop thinking about oxen + + align:start position:0% +plural suffix stop thinking about oxen + + + align:start position:0% +plural suffix stop thinking about oxen +and fish and sheep + + align:start position:0% +and fish and sheep + + + align:start position:0% +and fish and sheep +um cats and dogs and bushes we decided + + align:start position:0% +um cats and dogs and bushes we decided + + + align:start position:0% +um cats and dogs and bushes we decided +the underlying form of the plural suffix + + align:start position:0% +the underlying form of the plural suffix + + + align:start position:0% +the underlying form of the plural suffix +is a z right and it undergoes various + + align:start position:0% +is a z right and it undergoes various + + + align:start position:0% +is a z right and it undergoes various +kinds of sound changes depending on + + align:start position:0% +kinds of sound changes depending on + + + align:start position:0% +kinds of sound changes depending on +what's before it so you add Z to all + + align:start position:0% +what's before it so you add Z to all + + + align:start position:0% +what's before it so you add Z to all +three of these underlyingly and then + + align:start position:0% +three of these underlyingly and then + + + align:start position:0% +three of these underlyingly and then +there are generalizations like English + + align:start position:0% +there are generalizations like English + + + align:start position:0% +there are generalizations like English +doesn't like words that end in a z + + align:start position:0% +doesn't like words that end in a z + + + align:start position:0% +doesn't like words that end in a z +that's preceded by a voiceless sound + + align:start position:0% +that's preceded by a voiceless sound + + + align:start position:0% +that's preceded by a voiceless sound +and words don't get to end in two + + align:start position:0% +and words don't get to end in two + + + align:start position:0% +and words don't get to end in two +strident consonants right where + + align:start position:0% +strident consonants right where + + + align:start position:0% +strident consonants right where +stridents or things like the Shu and the + + align:start position:0% +stridents or things like the Shu and the + + + align:start position:0% +stridents or things like the Shu and the +Z that's at the end of bushes yeah + + align:start position:0% +Z that's at the end of bushes yeah + + + align:start position:0% +Z that's at the end of bushes yeah +um + + align:start position:0% +um + + + align:start position:0% +um +so those are generalizations but we said + + align:start position:0% +so those are generalizations but we said + + + align:start position:0% +so those are generalizations but we said +one of the attractive things about this + + align:start position:0% +one of the attractive things about this + + + align:start position:0% +one of the attractive things about this +way of thinking about the English plural + + align:start position:0% +way of thinking about the English plural + + + align:start position:0% +way of thinking about the English plural +is that these are generalizations that + + align:start position:0% +is that these are generalizations that + + + align:start position:0% +is that these are generalizations that +just seem to hold about English + + align:start position:0% +just seem to hold about English + + + align:start position:0% +just seem to hold about English +generally English doesn't have any words + + align:start position:0% +generally English doesn't have any words + + + align:start position:0% +generally English doesn't have any words +that end in a z preceded by a voiceless + + align:start position:0% +that end in a z preceded by a voiceless + + + align:start position:0% +that end in a z preceded by a voiceless +sound and we can kind of rely on English + + align:start position:0% +sound and we can kind of rely on English + + + align:start position:0% +sound and we can kind of rely on English +phonology to demand that you do + + align:start position:0% +phonology to demand that you do + + + align:start position:0% +phonology to demand that you do +something if you add Z to cat yeah + + align:start position:0% +something if you add Z to cat yeah + + + align:start position:0% +something if you add Z to cat yeah +um + + align:start position:0% +um + + + align:start position:0% +um +and then + + align:start position:0% +and then + + + align:start position:0% +and then +again we've said this before I just want + + align:start position:0% +again we've said this before I just want + + + align:start position:0% +again we've said this before I just want +to say it again a little more clearly + + align:start position:0% +to say it again a little more clearly + + + align:start position:0% +to say it again a little more clearly +there are these conditions and then + + align:start position:0% +there are these conditions and then + + + align:start position:0% +there are these conditions and then +there are also these procedures for + + align:start position:0% +there are also these procedures for + + + align:start position:0% +there are also these procedures for +repairing these violations so you know + + align:start position:0% +repairing these violations so you know + + + align:start position:0% +repairing these violations so you know +what do you do about the fact that you + + align:start position:0% +what do you do about the fact that you + + + align:start position:0% +what do you do about the fact that you +added Z to cat well you D voice the Z + + align:start position:0% +added Z to cat well you D voice the Z + + + align:start position:0% +added Z to cat well you D voice the Z +if the condition just says you can't + + align:start position:0% +if the condition just says you can't + + + align:start position:0% +if the condition just says you can't +have a z preceded by something voiceless + + align:start position:0% +have a z preceded by something voiceless + + + align:start position:0% +have a z preceded by something voiceless +there are various things you could have + + align:start position:0% +there are various things you could have + + + align:start position:0% +there are various things you could have +done to fix that problem you could have + + align:start position:0% +done to fix that problem you could have + + + align:start position:0% +done to fix that problem you could have +voiced the D right so the plural of cat + + align:start position:0% +voiced the D right so the plural of cat + + + align:start position:0% +voiced the D right so the plural of cat +could be cads right that would be a good + + align:start position:0% +could be cads right that would be a good + + + align:start position:0% +could be cads right that would be a good +English word or you could add a vowel + + align:start position:0% +English word or you could add a vowel + + + align:start position:0% +English word or you could add a vowel +like you do in bushes right the plural + + align:start position:0% +like you do in bushes right the plural + + + align:start position:0% +like you do in bushes right the plural +of cat could be catas you know there are + + align:start position:0% +of cat could be catas you know there are + + + align:start position:0% +of cat could be catas you know there are +various things that would fix that + + align:start position:0% +various things that would fix that + + + align:start position:0% +various things that would fix that +problem if that's the problem but this + + align:start position:0% +problem if that's the problem but this + + + align:start position:0% +problem if that's the problem but this +is the thing that you do yeah it's kind + + align:start position:0% +is the thing that you do yeah it's kind + + + align:start position:0% +is the thing that you do yeah it's kind +of like when we were talking about yeah + + align:start position:0% +of like when we were talking about yeah + + + align:start position:0% +of like when we were talking about yeah +well money we said you can't have three + + align:start position:0% +well money we said you can't have three + + + align:start position:0% +well money we said you can't have three +consonants in a row what do you do about + + align:start position:0% +consonants in a row what do you do about + + + align:start position:0% +consonants in a row what do you do about +it well it depends on the situation + + align:start position:0% +it well it depends on the situation + + + align:start position:0% +it well it depends on the situation +right so if one of them is an H you get + + align:start position:0% +right so if one of them is an H you get + + + align:start position:0% +right so if one of them is an H you get +rid of the H if not then you insert a + + align:start position:0% +rid of the H if not then you insert a + + + align:start position:0% +rid of the H if not then you insert a +vowel in this position and not that + + align:start position:0% +vowel in this position and not that + + + align:start position:0% +vowel in this position and not that +position so a similar kind of thing + + align:start position:0% +position so a similar kind of thing + + + align:start position:0% +position so a similar kind of thing +um + + align:start position:0% +um + + + align:start position:0% +um +so this is all a way of saying what we + + align:start position:0% +so this is all a way of saying what we + + + align:start position:0% +so this is all a way of saying what we +it's it's uh worthwhile maybe to + + align:start position:0% +it's it's uh worthwhile maybe to + + + align:start position:0% +it's it's uh worthwhile maybe to +distinguish between uh the phonotactic + + align:start position:0% +distinguish between uh the phonotactic + + + align:start position:0% +distinguish between uh the phonotactic +considerations or the the well informed + + align:start position:0% +considerations or the the well informed + + + align:start position:0% +considerations or the the well informed +in this considerations that tell you + + align:start position:0% +in this considerations that tell you + + + align:start position:0% +in this considerations that tell you +this language doesn't like uh three + + align:start position:0% +this language doesn't like uh three + + + align:start position:0% +this language doesn't like uh three +consonants in a row or two accented + + align:start position:0% +consonants in a row or two accented + + + align:start position:0% +consonants in a row or two accented +syllables in your word or uh words + + align:start position:0% +syllables in your word or uh words + + + align:start position:0% +syllables in your word or uh words +ending in a z preceded by a voiceless + + align:start position:0% +ending in a z preceded by a voiceless + + + align:start position:0% +ending in a z preceded by a voiceless +sound there's that kind of condition and + + align:start position:0% +sound there's that kind of condition and + + + align:start position:0% +sound there's that kind of condition and +then there's how do you repair it what + + align:start position:0% +then there's how do you repair it what + + + align:start position:0% +then there's how do you repair it what +kind of a repair do you use + + align:start position:0% +kind of a repair do you use + + + align:start position:0% +kind of a repair do you use +um so there's the well-formed in this + + align:start position:0% +um so there's the well-formed in this + + + align:start position:0% +um so there's the well-formed in this +condition and then there's the repair + + align:start position:0% +condition and then there's the repair + + + align:start position:0% +condition and then there's the repair +yeah so in this particular case the + + align:start position:0% +yeah so in this particular case the + + + align:start position:0% +yeah so in this particular case the +procedures are devoice and insert schwa + + align:start position:0% +procedures are devoice and insert schwa + + + align:start position:0% +procedures are devoice and insert schwa +um there's a particularly sort of + + align:start position:0% +um there's a particularly sort of + + + align:start position:0% +um there's a particularly sort of +striking bit of evidence for this way of + + align:start position:0% +striking bit of evidence for this way of + + + align:start position:0% +striking bit of evidence for this way of +dividing things up uh this distinction + + align:start position:0% +dividing things up uh this distinction + + + align:start position:0% +dividing things up uh this distinction +that I'm drawing between well-formedness + + align:start position:0% +that I'm drawing between well-formedness + + + align:start position:0% +that I'm drawing between well-formedness +conditions on words on the one hand and + + align:start position:0% +conditions on words on the one hand and + + + align:start position:0% +conditions on words on the one hand and +uh types of possible repair on the other + + align:start position:0% +uh types of possible repair on the other + + + align:start position:0% +uh types of possible repair on the other +that we need to think about both of + + align:start position:0% +that we need to think about both of + + + align:start position:0% +that we need to think about both of +those things if we're going to describe + + align:start position:0% +those things if we're going to describe + + + align:start position:0% +those things if we're going to describe +what the language is doing + + align:start position:0% +what the language is doing + + + align:start position:0% +what the language is doing +this is a classic test in 1957 I + + align:start position:0% +this is a classic test in 1957 I + + + align:start position:0% +this is a classic test in 1957 I +mentioned it in class before but I + + align:start position:0% +mentioned it in class before but I + + + align:start position:0% +mentioned it in class before but I +wanted to talk about it a little more + + align:start position:0% +wanted to talk about it a little more + + + align:start position:0% +wanted to talk about it a little more +now that we've drawn this distinction uh + + align:start position:0% +now that we've drawn this distinction uh + + + align:start position:0% +now that we've drawn this distinction uh +so uh Gene burco later Jean burko + + align:start position:0% +so uh Gene burco later Jean burko + + + align:start position:0% +so uh Gene burco later Jean burko +Gleason uh did this work in 1957 with + + align:start position:0% +Gleason uh did this work in 1957 with + + + align:start position:0% +Gleason uh did this work in 1957 with +children she was demonstrating that they + + align:start position:0% +children she was demonstrating that they + + + align:start position:0% +children she was demonstrating that they +know these generalizations about plurals + + align:start position:0% +know these generalizations about plurals + + + align:start position:0% +know these generalizations about plurals +uh even with words they've never heard + + align:start position:0% +uh even with words they've never heard + + + align:start position:0% +uh even with words they've never heard +before so she would show them pictures + + align:start position:0% +before so she would show them pictures + + + align:start position:0% +before so she would show them pictures +like this one this is one of her + + align:start position:0% +like this one this is one of her + + + align:start position:0% +like this one this is one of her +pictures she said this is a wug + + align:start position:0% +pictures she said this is a wug + + + align:start position:0% +pictures she said this is a wug +um and then she would show them + + align:start position:0% +um and then she would show them + + + align:start position:0% +um and then she would show them +two pictures of the same thing and she + + align:start position:0% +two pictures of the same thing and she + + + align:start position:0% +two pictures of the same thing and she +would say now there are two of them + + align:start position:0% +would say now there are two of them + + + align:start position:0% +would say now there are two of them +there are two and children were supposed + + align:start position:0% +there are two and children were supposed + + + align:start position:0% +there are two and children were supposed +to say + + align:start position:0% +to say + + + align:start position:0% +to say +bugs yeah uh even though they'd never + + align:start position:0% +bugs yeah uh even though they'd never + + + align:start position:0% +bugs yeah uh even though they'd never +heard anybody say well before right so + + align:start position:0% +heard anybody say well before right so + + + align:start position:0% +heard anybody say well before right so +Jean Virgo Gleason Gene burko uh made up + + align:start position:0% +Jean Virgo Gleason Gene burko uh made up + + + align:start position:0% +Jean Virgo Gleason Gene burko uh made up +a bunch of words she worked hard to make + + align:start position:0% +a bunch of words she worked hard to make + + + align:start position:0% +a bunch of words she worked hard to make +sure they were not real words and then + + align:start position:0% +sure they were not real words and then + + + align:start position:0% +sure they were not real words and then +she Drew many cute pictures uh and + + align:start position:0% +she Drew many cute pictures uh and + + + align:start position:0% +she Drew many cute pictures uh and +showed children singulars and plurals + + align:start position:0% +showed children singulars and plurals + + + align:start position:0% +showed children singulars and plurals +and said okay here's the singular what's + + align:start position:0% +and said okay here's the singular what's + + + align:start position:0% +and said okay here's the singular what's +the plural right and the kids + + align:start position:0% +the plural right and the kids + + + align:start position:0% +the plural right and the kids +um responded and she wrote down their + + align:start position:0% +um responded and she wrote down their + + + align:start position:0% +um responded and she wrote down their +responses and their responses + + align:start position:0% +responses and their responses + + + align:start position:0% +responses and their responses +interestingly were accurate uh in one + + align:start position:0% +interestingly were accurate uh in one + + + align:start position:0% +interestingly were accurate uh in one +way and sometimes inaccurate in another + + align:start position:0% +way and sometimes inaccurate in another + + + align:start position:0% +way and sometimes inaccurate in another +um + + align:start position:0% +um + + + align:start position:0% +um +interesting to think about so she was + + align:start position:0% +interesting to think about so she was + + + align:start position:0% +interesting to think about so she was +working with children who were five + + align:start position:0% +working with children who were five + + + align:start position:0% +working with children who were five +years old and children who were seven + + align:start position:0% +years old and children who were seven + + + align:start position:0% +years old and children who were seven +years old uh what she discovered was + + align:start position:0% +years old uh what she discovered was + + + align:start position:0% +years old uh what she discovered was +that by the time they're five years old + + align:start position:0% +that by the time they're five years old + + + align:start position:0% +that by the time they're five years old +they are in a sense perfect uh in the + + align:start position:0% +they are in a sense perfect uh in the + + + align:start position:0% +they are in a sense perfect uh in the +sense that all of the words that they + + align:start position:0% +sense that all of the words that they + + + align:start position:0% +sense that all of the words that they +came up with were phonatactically + + align:start position:0% +came up with were phonatactically + + + align:start position:0% +came up with were phonatactically +well-formed English words uh so here are + + align:start position:0% +well-formed English words uh so here are + + + align:start position:0% +well-formed English words uh so here are +three of uh burko's words heaths and + + align:start position:0% +three of uh burko's words heaths and + + + align:start position:0% +three of uh burko's words heaths and +Muzz yeah and uh well I think everybody + + align:start position:0% +Muzz yeah and uh well I think everybody + + + align:start position:0% +Muzz yeah and uh well I think everybody +did well perfectly everybody said the + + align:start position:0% +did well perfectly everybody said the + + + align:start position:0% +did well perfectly everybody said the +plural bug is wugs + + align:start position:0% +plural bug is wugs + + + align:start position:0% +plural bug is wugs +um but there were other cases where you + + align:start position:0% +um but there were other cases where you + + + align:start position:0% +um but there were other cases where you +know uh children would say sometimes + + align:start position:0% +know uh children would say sometimes + + + align:start position:0% +know uh children would say sometimes +things like the plural Thief is heifas + + align:start position:0% +things like the plural Thief is heifas + + + align:start position:0% +things like the plural Thief is heifas +or the plural of fast is fast or the + + align:start position:0% +or the plural of fast is fast or the + + + align:start position:0% +or the plural of fast is fast or the +plural of Moses Muzz + + align:start position:0% + + + + align:start position:0% + +these are all words where + + align:start position:0% +these are all words where + + + align:start position:0% +these are all words where +um and then there were other kinds of + + align:start position:0% +um and then there were other kinds of + + + align:start position:0% +um and then there were other kinds of +mistakes that children didn't make so um + + align:start position:0% +mistakes that children didn't make so um + + + align:start position:0% +mistakes that children didn't make so um +nobody said that the plural of wug was + + align:start position:0% +nobody said that the plural of wug was + + + align:start position:0% +nobody said that the plural of wug was +wugs you know or that the plural of wook + + align:start position:0% +wugs you know or that the plural of wook + + + align:start position:0% +wugs you know or that the plural of wook +is right or that the plural fast as fast + + align:start position:0% +is right or that the plural fast as fast + + + align:start position:0% +is right or that the plural fast as fast +as + + align:start position:0% + + + + align:start position:0% + +what were children doing well children + + align:start position:0% +what were children doing well children + + + align:start position:0% +what were children doing well children +know if you show them something that's + + align:start position:0% +know if you show them something that's + + + align:start position:0% +know if you show them something that's +underlyingly you know you give them + + align:start position:0% +underlyingly you know you give them + + + align:start position:0% +underlyingly you know you give them +Heath + + align:start position:0% +Heath + + + align:start position:0% +Heath +for some reason I'm spelling backwards + + align:start position:0% +for some reason I'm spelling backwards + + + align:start position:0% +for some reason I'm spelling backwards +you give them Heath and you ask them the + + align:start position:0% +you give them Heath and you ask them the + + + align:start position:0% +you give them Heath and you ask them the +plural they know that you're supposed to + + align:start position:0% +plural they know that you're supposed to + + + align:start position:0% +plural they know that you're supposed to +add a z and they know that English + + align:start position:0% +add a z and they know that English + + + align:start position:0% +add a z and they know that English +doesn't allow words that end in a z + + align:start position:0% +doesn't allow words that end in a z + + + align:start position:0% +doesn't allow words that end in a z +preceded by a voiceless sound + + align:start position:0% +preceded by a voiceless sound + + + align:start position:0% +preceded by a voiceless sound +but some of these five and + + align:start position:0% +but some of these five and + + + align:start position:0% +but some of these five and +seven-year-olds were a little fuzzy on + + align:start position:0% +seven-year-olds were a little fuzzy on + + + align:start position:0% +seven-year-olds were a little fuzzy on +on the possible repairs + + align:start position:0% +on the possible repairs + + + align:start position:0% +on the possible repairs +so + + align:start position:0% +so + + + align:start position:0% +so +um they none of them said oh yeah it's + + align:start position:0% +um they none of them said oh yeah it's + + + align:start position:0% +um they none of them said oh yeah it's +he right + + align:start position:0% +he right + + + align:start position:0% +he right +but I just said this if the only problem + + align:start position:0% +but I just said this if the only problem + + + align:start position:0% +but I just said this if the only problem +is well this word ends in the voiceless + + align:start position:0% +is well this word ends in the voiceless + + + align:start position:0% +is well this word ends in the voiceless +sound followed by a z in fact what + + align:start position:0% +sound followed by a z in fact what + + + align:start position:0% +sound followed by a z in fact what +you're supposed to do is devoice the Z + + align:start position:0% +you're supposed to do is devoice the Z + + + align:start position:0% +you're supposed to do is devoice the Z +that's what an adult would do it's a + + align:start position:0% +that's what an adult would do it's a + + + align:start position:0% +that's what an adult would do it's a +plural Thief is heafs yeah but if you + + align:start position:0% +plural Thief is heafs yeah but if you + + + align:start position:0% +plural Thief is heafs yeah but if you +were instead to insert a schwa well that + + align:start position:0% +were instead to insert a schwa well that + + + align:start position:0% +were instead to insert a schwa well that +would fix it too right so uh now the Z + + align:start position:0% +would fix it too right so uh now the Z + + + align:start position:0% +would fix it too right so uh now the Z +is preceded by a voiced sound the plural + + align:start position:0% +is preceded by a voiced sound the plural + + + align:start position:0% +is preceded by a voiced sound the plural +Thief is yeah and there were some kids + + align:start position:0% +Thief is yeah and there were some kids + + + align:start position:0% +Thief is yeah and there were some kids +who were going through a stage who were + + align:start position:0% +who were going through a stage who were + + + align:start position:0% +who were going through a stage who were +entertaining that possibility you know + + align:start position:0% +entertaining that possibility you know + + + align:start position:0% +entertaining that possibility you know +that that was the correct repair for + + align:start position:0% +that that was the correct repair for + + + align:start position:0% +that that was the correct repair for +that so what what uh berko found was + + align:start position:0% +that so what what uh berko found was + + + align:start position:0% +that so what what uh berko found was +that children uh universally knew the + + align:start position:0% +that children uh universally knew the + + + align:start position:0% +that children uh universally knew the +phono tactics right they they knew that + + align:start position:0% +phono tactics right they they knew that + + + align:start position:0% +phono tactics right they they knew that +English doesn't allow words that end in + + align:start position:0% +English doesn't allow words that end in + + + align:start position:0% +English doesn't allow words that end in +the Z preceded by a voiceless sound but + + align:start position:0% +the Z preceded by a voiceless sound but + + + align:start position:0% +the Z preceded by a voiceless sound but +they made sort of uh intriguing mistakes + + align:start position:0% +they made sort of uh intriguing mistakes + + + align:start position:0% +they made sort of uh intriguing mistakes +of various kinds not very often most of + + align:start position:0% +of various kinds not very often most of + + + align:start position:0% +of various kinds not very often most of +the kids just did everything perfectly + + align:start position:0% +the kids just did everything perfectly + + + align:start position:0% +the kids just did everything perfectly +but every so often she would get kids + + align:start position:0% +but every so often she would get kids + + + align:start position:0% +but every so often she would get kids +who made some mistakes and the mistakes + + align:start position:0% +who made some mistakes and the mistakes + + + align:start position:0% +who made some mistakes and the mistakes +were of this class that is mistakes + + align:start position:0% +were of this class that is mistakes + + + align:start position:0% +were of this class that is mistakes +where they knew that there needed to be + + align:start position:0% +where they knew that there needed to be + + + align:start position:0% +where they knew that there needed to be +a repair but got the repair wrong + + align:start position:0% +a repair but got the repair wrong + + + align:start position:0% +a repair but got the repair wrong +similarly for Muzz this was a kid who + + align:start position:0% +similarly for Muzz this was a kid who + + + align:start position:0% +similarly for Muzz this was a kid who +you know the singular is Muzz and the + + align:start position:0% +you know the singular is Muzz and the + + + align:start position:0% +you know the singular is Muzz and the +kid knows that you need to add a z and + + align:start position:0% +kid knows that you need to add a z and + + + align:start position:0% +kid knows that you need to add a z and +the kid knows that you can't have two + + align:start position:0% +the kid knows that you can't have two + + + align:start position:0% +the kid knows that you can't have two +stridents at the end of a word the + + align:start position:0% +stridents at the end of a word the + + + align:start position:0% +stridents at the end of a word the +correct answer the adult's answer is to + + align:start position:0% +correct answer the adult's answer is to + + + align:start position:0% +correct answer the adult's answer is to +insert a schwa so the plural of Muzz + + align:start position:0% +insert a schwa so the plural of Muzz + + + align:start position:0% +insert a schwa so the plural of Muzz +will be muzzes but uh deleting the Z one + + align:start position:0% +will be muzzes but uh deleting the Z one + + + align:start position:0% +will be muzzes but uh deleting the Z one +of the Z is hard to know which one uh + + align:start position:0% +of the Z is hard to know which one uh + + + align:start position:0% +of the Z is hard to know which one uh +also fixes that problem and so uh that + + align:start position:0% +also fixes that problem and so uh that + + + align:start position:0% +also fixes that problem and so uh that +was a kid who thought yeah I'll delete a + + align:start position:0% +was a kid who thought yeah I'll delete a + + + align:start position:0% +was a kid who thought yeah I'll delete a +z yeah yeah Joseph + + align:start position:0% + + + + align:start position:0% + +as something that English does yeah no + + align:start position:0% +as something that English does yeah no + + + align:start position:0% +as something that English does yeah no +so English there aren't I don't think + + align:start position:0% +so English there aren't I don't think + + + align:start position:0% +so English there aren't I don't think +any English nouns + + align:start position:0% +any English nouns + + + align:start position:0% +any English nouns +that form their plural by adding a z and + + align:start position:0% +that form their plural by adding a z and + + + align:start position:0% +that form their plural by adding a z and +deleting something before the Z don't + + align:start position:0% +deleting something before the Z don't + + + align:start position:0% +deleting something before the Z don't +believe + + align:start position:0% +believe + + + align:start position:0% +believe +that ever happens yeah this is me + + align:start position:0% +that ever happens yeah this is me + + + align:start position:0% +that ever happens yeah this is me +slowing down while I tried to think of + + align:start position:0% +slowing down while I tried to think of + + + align:start position:0% +slowing down while I tried to think of +English nouns of which I know several + + align:start position:0% +English nouns of which I know several + + + align:start position:0% +English nouns of which I know several +but + + align:start position:0% +but + + + align:start position:0% +but +um I can't think of any of it I can't + + align:start position:0% +um I can't think of any of it I can't + + + align:start position:0% +um I can't think of any of it I can't +think of any to do that yeah + + align:start position:0% + + + + align:start position:0% + +um yeah so is this clear another reason + + align:start position:0% +um yeah so is this clear another reason + + + align:start position:0% +um yeah so is this clear another reason +to draw this distinction between on the + + align:start position:0% +to draw this distinction between on the + + + align:start position:0% +to draw this distinction between on the +one hand + + align:start position:0% +one hand + + + align:start position:0% +one hand +what I was calling phonotactics these + + align:start position:0% +what I was calling phonotactics these + + + align:start position:0% +what I was calling phonotactics these +rules for which kinds of sounds can be + + align:start position:0% +rules for which kinds of sounds can be + + + align:start position:0% +rules for which kinds of sounds can be +where uh and on the other hand the + + align:start position:0% +where uh and on the other hand the + + + align:start position:0% +where uh and on the other hand the +repairs so uh uh the kids that burka was + + align:start position:0% +repairs so uh uh the kids that burka was + + + align:start position:0% +repairs so uh uh the kids that burka was +working with uh knew the founder tactics + + align:start position:0% +working with uh knew the founder tactics + + + align:start position:0% +working with uh knew the founder tactics +but were sometimes fuzzy on what the + + align:start position:0% +but were sometimes fuzzy on what the + + + align:start position:0% +but were sometimes fuzzy on what the +correct repairs were um + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so moral yet again needed to distinguish + + align:start position:0% +so moral yet again needed to distinguish + + + align:start position:0% +so moral yet again needed to distinguish +between on the one hand the phony + + align:start position:0% +between on the one hand the phony + + + align:start position:0% +between on the one hand the phony +tactics and on the other hand the + + align:start position:0% +tactics and on the other hand the + + + align:start position:0% +tactics and on the other hand the +particular sound changes the repairs + + align:start position:0% +particular sound changes the repairs + + + align:start position:0% +particular sound changes the repairs +that enforce the phonotactics it's + + align:start position:0% +that enforce the phonotactics it's + + + align:start position:0% +that enforce the phonotactics it's +apparently possible to know one of those + + align:start position:0% +apparently possible to know one of those + + + align:start position:0% +apparently possible to know one of those +but not the other + + align:start position:0% + + + + align:start position:0% + +um okay that + + align:start position:0% +um okay that + + + align:start position:0% +um okay that +ends a chapter yeah now we're going to + + align:start position:0% +ends a chapter yeah now we're going to + + + align:start position:0% +ends a chapter yeah now we're going to +talk about something else + + align:start position:0% +talk about something else + + + align:start position:0% +talk about something else +so are there any questions about that is + + align:start position:0% +so are there any questions about that is + + + align:start position:0% +so are there any questions about that is +that clear + + align:start position:0% +that clear + + + align:start position:0% +that clear +um we've already done some of this but I + + align:start position:0% +um we've already done some of this but I + + + align:start position:0% +um we've already done some of this but I +want to do more + + align:start position:0% +want to do more + + + align:start position:0% +want to do more +we've been talking about how uh there + + align:start position:0% +we've been talking about how uh there + + + align:start position:0% +we've been talking about how uh there +are some kinds of sound changes that are + + align:start position:0% +are some kinds of sound changes that are + + + align:start position:0% +are some kinds of sound changes that are +natural because they apply to Natural + + align:start position:0% +natural because they apply to Natural + + + align:start position:0% +natural because they apply to Natural +classes of things uh sort of can be + + align:start position:0% +classes of things uh sort of can be + + + align:start position:0% +classes of things uh sort of can be +almost circular uh so you know I quickly + + align:start position:0% +almost circular uh so you know I quickly + + + align:start position:0% +almost circular uh so you know I quickly +introduced you to the word strivons + + align:start position:0% +introduced you to the word strivons + + + align:start position:0% +introduced you to the word strivons +because the generalization about English + + align:start position:0% +because the generalization about English + + + align:start position:0% +because the generalization about English +plurals is that two stridents can't end + + align:start position:0% +plurals is that two stridents can't end + + + align:start position:0% +plurals is that two stridents can't end +the word in English and that's why you + + align:start position:0% +the word in English and that's why you + + + align:start position:0% +the word in English and that's why you +introduce a schwa just in case you're in + + align:start position:0% +introduce a schwa just in case you're in + + + align:start position:0% +introduce a schwa just in case you're in +danger of having two stridents at the + + align:start position:0% +danger of having two stridents at the + + + align:start position:0% +danger of having two stridents at the +end of your word + + align:start position:0% +end of your word + + + align:start position:0% +end of your word +um uh straight in the word strident uh + + align:start position:0% +um uh straight in the word strident uh + + + align:start position:0% +um uh straight in the word strident uh +has an acoustic definition they are + + align:start position:0% +has an acoustic definition they are + + + align:start position:0% +has an acoustic definition they are +fricatives that have lots of high + + align:start position:0% +fricatives that have lots of high + + + align:start position:0% +fricatives that have lots of high +frequency noise uh but uh it's kind of + + align:start position:0% +frequency noise uh but uh it's kind of + + + align:start position:0% +frequency noise uh but uh it's kind of +of interest that there are phenomena + + align:start position:0% +of interest that there are phenomena + + + align:start position:0% +of interest that there are phenomena +like the alamorphy and English plurals + + align:start position:0% +like the alamorphy and English plurals + + + align:start position:0% +like the alamorphy and English plurals +that make reference to That acoustic + + align:start position:0% +that make reference to That acoustic + + + align:start position:0% +that make reference to That acoustic +fact that's apparently something that a + + align:start position:0% +fact that's apparently something that a + + + align:start position:0% +fact that's apparently something that a +language can care about uh how much high + + align:start position:0% +language can care about uh how much high + + + align:start position:0% +language can care about uh how much high +frequency noise you have at once + + align:start position:0% +frequency noise you have at once + + + align:start position:0% +frequency noise you have at once +um it's also something that varies from + + align:start position:0% +um it's also something that varies from + + + align:start position:0% +um it's also something that varies from +language to language there are certain + + align:start position:0% +language to language there are certain + + + align:start position:0% +language to language there are certain +languages that are perfectly happy to + + align:start position:0% +languages that are perfectly happy to + + + align:start position:0% +languages that are perfectly happy to +have long strings of stridents uh + + align:start position:0% +have long strings of stridents uh + + + align:start position:0% +have long strings of stridents uh +English just isn't one of them + + align:start position:0% +English just isn't one of them + + + align:start position:0% +English just isn't one of them +yep + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +we've already done as I said some + + align:start position:0% +we've already done as I said some + + + align:start position:0% +we've already done as I said some +talking about this so when I was first + + align:start position:0% +talking about this so when I was first + + + align:start position:0% +talking about this so when I was first +introducing you to consonants or + + align:start position:0% +introducing you to consonants or + + + align:start position:0% +introducing you to consonants or +introducing you to vowels I mean you'd + + align:start position:0% +introducing you to vowels I mean you'd + + + align:start position:0% +introducing you to vowels I mean you'd +already met Constance at some point in + + align:start position:0% +already met Constance at some point in + + + align:start position:0% +already met Constance at some point in +your life but we were talking about them + + align:start position:0% +your life but we were talking about them + + + align:start position:0% +your life but we were talking about them +in a particular systematic way uh we + + align:start position:0% +in a particular systematic way uh we + + + align:start position:0% +in a particular systematic way uh we +talked about various ways of classifying + + align:start position:0% +talked about various ways of classifying + + + align:start position:0% +talked about various ways of classifying +them uh saying you know there are some + + align:start position:0% +them uh saying you know there are some + + + align:start position:0% +them uh saying you know there are some +consonants that are fricatives and some + + align:start position:0% +consonants that are fricatives and some + + + align:start position:0% +consonants that are fricatives and some +consonants that are stops or saying + + align:start position:0% +consonants that are stops or saying + + + align:start position:0% +consonants that are stops or saying +there are some consonants that are + + align:start position:0% +there are some consonants that are + + + align:start position:0% +there are some consonants that are +voiced and some consonants that are + + align:start position:0% +voiced and some consonants that are + + + align:start position:0% +voiced and some consonants that are +voiceless so what I want to do today is + + align:start position:0% +voiceless so what I want to do today is + + + align:start position:0% +voiceless so what I want to do today is +to introduce you to some other kinds of + + align:start position:0% +to introduce you to some other kinds of + + + align:start position:0% +to introduce you to some other kinds of +classification and they'll as much as + + align:start position:0% +classification and they'll as much as + + + align:start position:0% +classification and they'll as much as +possible try to show you places where + + align:start position:0% +possible try to show you places where + + + align:start position:0% +possible try to show you places where +languages care about a particular class + + align:start position:0% +languages care about a particular class + + + align:start position:0% +languages care about a particular class +of sounds again this is all in the + + align:start position:0% +of sounds again this is all in the + + + align:start position:0% +of sounds again this is all in the +service of making it easier easier for + + align:start position:0% +service of making it easier easier for + + + align:start position:0% +service of making it easier easier for +us to understand why certain kinds of + + align:start position:0% +us to understand why certain kinds of + + + align:start position:0% +us to understand why certain kinds of +sound changes are natural and others uh + + align:start position:0% +sound changes are natural and others uh + + + align:start position:0% +sound changes are natural and others uh +are are not + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +here's one that we've already seen there + + align:start position:0% +here's one that we've already seen there + + + align:start position:0% +here's one that we've already seen there +are sounds that are nasal + + align:start position:0% +are sounds that are nasal + + + align:start position:0% +are sounds that are nasal +this is a contrast that I believe I have + + align:start position:0% +this is a contrast that I believe I have + + + align:start position:0% +this is a contrast that I believe I have +introduced you to before but let me + + align:start position:0% +introduced you to before but let me + + + align:start position:0% +introduced you to before but let me +introduce you to it again there's a + + align:start position:0% +introduce you to it again there's a + + + align:start position:0% +introduce you to it again there's a +distinction + + align:start position:0% +distinction + + + align:start position:0% +distinction +um I think I brought this up last time + + align:start position:0% +um I think I brought this up last time + + + align:start position:0% +um I think I brought this up last time +actually there's a distinction when we + + align:start position:0% +actually there's a distinction when we + + + align:start position:0% +actually there's a distinction when we +talk about consonants between what are + + align:start position:0% +talk about consonants between what are + + + align:start position:0% +talk about consonants between what are +called sonorants + + align:start position:0% +called sonorants + + + align:start position:0% +called sonorants +and what are called obstructs so these + + align:start position:0% +and what are called obstructs so these + + + align:start position:0% +and what are called obstructs so these +are opposites of each other I hope I + + align:start position:0% +are opposites of each other I hope I + + + align:start position:0% +are opposites of each other I hope I +have the word obstrand on a later slide + + align:start position:0% +have the word obstrand on a later slide + + + align:start position:0% +have the word obstrand on a later slide +but just in case I don't there are these + + align:start position:0% +but just in case I don't there are these + + + align:start position:0% +but just in case I don't there are these +two kinds of sounds obstruents + + align:start position:0% +two kinds of sounds obstruents + + + align:start position:0% +two kinds of sounds obstruents +and sonorants + + align:start position:0% +and sonorants + + + align:start position:0% +and sonorants +and the distinction between them has to + + align:start position:0% +and the distinction between them has to + + + align:start position:0% +and the distinction between them has to +do with whether you are building up + + align:start position:0% +do with whether you are building up + + + align:start position:0% +do with whether you are building up +pressure in the oral cavity so uh the + + align:start position:0% +pressure in the oral cavity so uh the + + + align:start position:0% +pressure in the oral cavity so uh the +sonorants are the nasals and the liquids + + align:start position:0% +sonorants are the nasals and the liquids + + + align:start position:0% +sonorants are the nasals and the liquids +and the Glides the the consonants in + + align:start position:0% +and the Glides the the consonants in + + + align:start position:0% +and the Glides the the consonants in +which there's no pressure building up in + + align:start position:0% +which there's no pressure building up in + + + align:start position:0% +which there's no pressure building up in +the oral cavity + + align:start position:0% +the oral cavity + + + align:start position:0% +the oral cavity +whereas the obstruents those are the + + align:start position:0% +whereas the obstruents those are the + + + align:start position:0% +whereas the obstruents those are the +stops and the fricatives the oral stops + + align:start position:0% +stops and the fricatives the oral stops + + + align:start position:0% +stops and the fricatives the oral stops +the fricatives those are the sounds in + + align:start position:0% +the fricatives those are the sounds in + + + align:start position:0% +the fricatives those are the sounds in +which there is pressure building up in + + align:start position:0% +which there is pressure building up in + + + align:start position:0% +which there is pressure building up in +the oral cavity for a stop it's because + + align:start position:0% +the oral cavity for a stop it's because + + + align:start position:0% +the oral cavity for a stop it's because +well you've stopped the flow there at + + align:start position:0% +well you've stopped the flow there at + + + align:start position:0% +well you've stopped the flow there at +the mouth and so pressure is building up + + align:start position:0% +the mouth and so pressure is building up + + + align:start position:0% +the mouth and so pressure is building up +and for a fricative uh well you haven't + + align:start position:0% +and for a fricative uh well you haven't + + + align:start position:0% +and for a fricative uh well you haven't +stopped the flow of air but you're + + align:start position:0% +stopped the flow of air but you're + + + align:start position:0% +stopped the flow of air but you're +constricting it that's how you make a + + align:start position:0% +constricting it that's how you make a + + + align:start position:0% +constricting it that's how you make a +fricative and so pressure is building up + + align:start position:0% +fricative and so pressure is building up + + + align:start position:0% +fricative and so pressure is building up +in the oral cavity and when I say + + align:start position:0% +in the oral cavity and when I say + + + align:start position:0% +in the oral cavity and when I say +pressure is building up in the oral + + align:start position:0% +pressure is building up in the oral + + + align:start position:0% +pressure is building up in the oral +cavity what I mean is that phoneticists + + align:start position:0% +cavity what I mean is that phoneticists + + + align:start position:0% +cavity what I mean is that phoneticists +have put instruments inside people's + + align:start position:0% +have put instruments inside people's + + + align:start position:0% +have put instruments inside people's +mouths to measure air pressure to find + + align:start position:0% +mouths to measure air pressure to find + + + align:start position:0% +mouths to measure air pressure to find +out what happens and they've discovered + + align:start position:0% +out what happens and they've discovered + + + align:start position:0% +out what happens and they've discovered +that this is true yeah so + + align:start position:0% +that this is true yeah so + + + align:start position:0% +that this is true yeah so +um I I try not to lie to you in this + + align:start position:0% +um I I try not to lie to you in this + + + align:start position:0% +um I I try not to lie to you in this +class any more than I can help it but in + + align:start position:0% +class any more than I can help it but in + + + align:start position:0% +class any more than I can help it but in +this particular case what I'm saying is + + align:start position:0% +this particular case what I'm saying is + + + align:start position:0% +this particular case what I'm saying is +absolutely true yeah + + align:start position:0% + + + + align:start position:0% + +um okay so there's honorance and there + + align:start position:0% +um okay so there's honorance and there + + + align:start position:0% +um okay so there's honorance and there +are obstrands uh we have already talked + + align:start position:0% +are obstrands uh we have already talked + + + align:start position:0% +are obstrands uh we have already talked +about the classification of sounds into + + align:start position:0% +about the classification of sounds into + + + align:start position:0% +about the classification of sounds into +voiced and voiceless sounds so the red + + align:start position:0% +voiced and voiceless sounds so the red + + + align:start position:0% +voiced and voiceless sounds so the red +sounds on this slide are voiced uh and + + align:start position:0% +sounds on this slide are voiced uh and + + + align:start position:0% +sounds on this slide are voiced uh and +as you can see this crosscuts some of + + align:start position:0% +as you can see this crosscuts some of + + + align:start position:0% +as you can see this crosscuts some of +the other classifications so you know + + align:start position:0% +the other classifications so you know + + + align:start position:0% +the other classifications so you know +you can be uh you can be an obstruent + + align:start position:0% +you can be uh you can be an obstruent + + + align:start position:0% +you can be uh you can be an obstruent +like a stop or a fricative and you can + + align:start position:0% +like a stop or a fricative and you can + + + align:start position:0% +like a stop or a fricative and you can +be either voiced or voiceless yeah so uh + + align:start position:0% +be either voiced or voiceless yeah so uh + + + align:start position:0% +be either voiced or voiceless yeah so uh +English stops can be voiced or voiceless + + align:start position:0% +English stops can be voiced or voiceless + + + align:start position:0% +English stops can be voiced or voiceless +English fricatives can be voiced or + + align:start position:0% +English fricatives can be voiced or + + + align:start position:0% +English fricatives can be voiced or +voiceless + + align:start position:0% +voiceless + + + align:start position:0% +voiceless +English sonorants interestingly can only + + align:start position:0% +English sonorants interestingly can only + + + align:start position:0% +English sonorants interestingly can only +be voiced they cannot be voiceless we + + align:start position:0% +be voiced they cannot be voiceless we + + + align:start position:0% +be voiced they cannot be voiceless we +have sonderance like like L like little + + align:start position:0% +have sonderance like like L like little + + + align:start position:0% +have sonderance like like L like little +but we don't have a voiceless version of + + align:start position:0% +but we don't have a voiceless version of + + + align:start position:0% +but we don't have a voiceless version of +L we talked about this when we were + + align:start position:0% +L we talked about this when we were + + + align:start position:0% +L we talked about this when we were +first going through uh sounds there are + + align:start position:0% +first going through uh sounds there are + + + align:start position:0% +first going through uh sounds there are +languages out there that have a + + align:start position:0% +languages out there that have a + + + align:start position:0% +languages out there that have a +voiceless version of L that have a sound + + align:start position:0% +voiceless version of L that have a sound + + + align:start position:0% +voiceless version of L that have a sound +uh Tibetan has one for example uh so if + + align:start position:0% +uh Tibetan has one for example uh so if + + + align:start position:0% +uh Tibetan has one for example uh so if +you go to Casa the capital of Tibet you + + align:start position:0% +you go to Casa the capital of Tibet you + + + align:start position:0% +you go to Casa the capital of Tibet you +must learn to make voiceless cells uh uh + + align:start position:0% +must learn to make voiceless cells uh uh + + + align:start position:0% +must learn to make voiceless cells uh uh +Welsh + + align:start position:0% +Welsh + + + align:start position:0% +Welsh +um has a voiceless L it's they spell it + + align:start position:0% +um has a voiceless L it's they spell it + + + align:start position:0% +um has a voiceless L it's they spell it +with two L's so if you look at Welsh + + align:start position:0% +with two L's so if you look at Welsh + + + align:start position:0% +with two L's so if you look at Welsh +words you'll see pairs of L's that's + + align:start position:0% +words you'll see pairs of L's that's + + + align:start position:0% +words you'll see pairs of L's that's +their way of spelling of voiceless a + + align:start position:0% +their way of spelling of voiceless a + + + align:start position:0% +their way of spelling of voiceless a +voiceless cell so there's a traditional + + align:start position:0% +voiceless cell so there's a traditional + + + align:start position:0% +voiceless cell so there's a traditional +Welsh name spelled like this and + + align:start position:0% +Welsh name spelled like this and + + + align:start position:0% +Welsh name spelled like this and +pronounced Floyd + + align:start position:0% +pronounced Floyd + + + align:start position:0% +pronounced Floyd +uh which has been borrowed into English + + align:start position:0% +uh which has been borrowed into English + + + align:start position:0% +uh which has been borrowed into English +twice as the name Lloyd and the name + + align:start position:0% +twice as the name Lloyd and the name + + + align:start position:0% +twice as the name Lloyd and the name +Floyd + + align:start position:0% +Floyd + + + align:start position:0% +Floyd +these are both attempts to pronounce + + align:start position:0% +these are both attempts to pronounce + + + align:start position:0% +these are both attempts to pronounce +Floyd which we can't pronounce because + + align:start position:0% +Floyd which we can't pronounce because + + + align:start position:0% +Floyd which we can't pronounce because +we don't have that sound + + align:start position:0% +we don't have that sound + + + align:start position:0% +we don't have that sound +um uh yeah so uh English has uh voiced + + align:start position:0% +um uh yeah so uh English has uh voiced + + + align:start position:0% +um uh yeah so uh English has uh voiced +and voiceless obstruents stops and + + align:start position:0% +and voiceless obstruents stops and + + + align:start position:0% +and voiceless obstruents stops and +fricatives but it only has voiced + + align:start position:0% +fricatives but it only has voiced + + + align:start position:0% +fricatives but it only has voiced +dishonorance that's a very common state + + align:start position:0% +dishonorance that's a very common state + + + align:start position:0% +dishonorance that's a very common state +of affairs uh if you're gonna have a + + align:start position:0% +of affairs uh if you're gonna have a + + + align:start position:0% +of affairs uh if you're gonna have a +voicing distinction in only one of these + + align:start position:0% +voicing distinction in only one of these + + + align:start position:0% +voicing distinction in only one of these +places it's in the obstrands uh language + + align:start position:0% +places it's in the obstrands uh language + + + align:start position:0% +places it's in the obstrands uh language +is only having voiced sonorants that's + + align:start position:0% +is only having voiced sonorants that's + + + align:start position:0% +is only having voiced sonorants that's +very common yeah + + align:start position:0% +very common yeah + + + align:start position:0% +very common yeah +though not Universal as we've said + + align:start position:0% + + + + align:start position:0% + +um quick interlude + + align:start position:0% +um quick interlude + + + align:start position:0% +um quick interlude +to use one of these features here are a + + align:start position:0% +to use one of these features here are a + + + align:start position:0% +to use one of these features here are a +bunch of uh verbs that you can make out + + align:start position:0% +bunch of uh verbs that you can make out + + + align:start position:0% +bunch of uh verbs that you can make out +of adjectives so you can take an + + align:start position:0% +of adjectives so you can take an + + + align:start position:0% +of adjectives so you can take an +adjective like black + + align:start position:0% +adjective like black + + + align:start position:0% +adjective like black +and you can make a verb blackened which + + align:start position:0% +and you can make a verb blackened which + + + align:start position:0% +and you can make a verb blackened which +can be either a transitive verb or an + + align:start position:0% +can be either a transitive verb or an + + + align:start position:0% +can be either a transitive verb or an +intrinsic verb I guess so uh you can you + + align:start position:0% +intrinsic verb I guess so uh you can you + + + align:start position:0% +intrinsic verb I guess so uh you can you +can blacken + + align:start position:0% +can blacken + + + align:start position:0% +can blacken +um the paper or blacken the fish I guess + + align:start position:0% +um the paper or blacken the fish I guess + + + align:start position:0% +um the paper or blacken the fish I guess +it means to make it black yeah + + align:start position:0% +it means to make it black yeah + + + align:start position:0% +it means to make it black yeah +similarly something can whiten or lessen + + align:start position:0% +similarly something can whiten or lessen + + + align:start position:0% +similarly something can whiten or lessen +or freshen or darkening you can offer to + + align:start position:0% +or freshen or darkening you can offer to + + + align:start position:0% +or freshen or darkening you can offer to +freshen a drink say yeah it means to + + align:start position:0% +freshen a drink say yeah it means to + + + align:start position:0% +freshen a drink say yeah it means to +make it fresh right so this is there's + + align:start position:0% +make it fresh right so this is there's + + + align:start position:0% +make it fresh right so this is there's +this um that you can add to adjectives + + align:start position:0% +this um that you can add to adjectives + + + align:start position:0% +this um that you can add to adjectives +to make verbs + + align:start position:0% +to make verbs + + + align:start position:0% +to make verbs +sound right + + align:start position:0% +sound right + + + align:start position:0% +sound right +on the other hand there are these other + + align:start position:0% +on the other hand there are these other + + + align:start position:0% +on the other hand there are these other +adjectives + + align:start position:0% + + + + align:start position:0% + +which can't happen yeah so + + align:start position:0% +which can't happen yeah so + + + align:start position:0% +which can't happen yeah so +um the the screen of a computer can + + align:start position:0% +um the the screen of a computer can + + + align:start position:0% +um the the screen of a computer can +darken but it cannot yellow in yeah a + + align:start position:0% +darken but it cannot yellow in yeah a + + + align:start position:0% +darken but it cannot yellow in yeah a +piece of paper uh that gets old uh you + + align:start position:0% +piece of paper uh that gets old uh you + + + align:start position:0% +piece of paper uh that gets old uh you +what you say is that it yellows it + + align:start position:0% +what you say is that it yellows it + + + align:start position:0% +what you say is that it yellows it +yellowed with age you don't say that it + + align:start position:0% +yellowed with age you don't say that it + + + align:start position:0% +yellowed with age you don't say that it +yellow end yeah similarly you can't + + align:start position:0% +yellow end yeah similarly you can't + + + align:start position:0% +yellow end yeah similarly you can't +demon or gray in or clearing or Browning + + align:start position:0% +demon or gray in or clearing or Browning + + + align:start position:0% +demon or gray in or clearing or Browning +yeah all of those things if you want to + + align:start position:0% +yeah all of those things if you want to + + + align:start position:0% +yeah all of those things if you want to +make them into verbs you just they're + + align:start position:0% +make them into verbs you just they're + + + align:start position:0% +make them into verbs you just they're +verbs yeah + + align:start position:0% +verbs yeah + + + align:start position:0% +verbs yeah +yeah does that sound right + + align:start position:0% +yeah does that sound right + + + align:start position:0% +yeah does that sound right +what's the difference between black + + align:start position:0% +what's the difference between black + + + align:start position:0% +what's the difference between black +white less fresh and dark on the one + + align:start position:0% +white less fresh and dark on the one + + + align:start position:0% +white less fresh and dark on the one +hand and yellow dim gray clear and brown + + align:start position:0% +hand and yellow dim gray clear and brown + + + align:start position:0% +hand and yellow dim gray clear and brown +on the other + + align:start position:0% +on the other + + + align:start position:0% +on the other +the endless voiceless + + align:start position:0% +the endless voiceless + + + align:start position:0% +the endless voiceless +stops on the first line in the first + + align:start position:0% +stops on the first line in the first + + + align:start position:0% +stops on the first line in the first +line black white and dark end with + + align:start position:0% +line black white and dark end with + + + align:start position:0% +line black white and dark end with +voiceless stops and less and fresh + + align:start position:0% +voiceless stops and less and fresh + + + align:start position:0% +voiceless stops and less and fresh +and with voiceless fricatives yeah yeah + + align:start position:0% +and with voiceless fricatives yeah yeah + + + align:start position:0% +and with voiceless fricatives yeah yeah +yeah yeah nice + + align:start position:0% + + + + align:start position:0% + +and yellow dim gray clear and brown + + align:start position:0% +and yellow dim gray clear and brown + + + align:start position:0% +and yellow dim gray clear and brown +and in voiced sounds + + align:start position:0% + + + + align:start position:0% + +what's the cover term for uh stops and + + align:start position:0% +what's the cover term for uh stops and + + + align:start position:0% +what's the cover term for uh stops and +fricatives + + align:start position:0% +fricatives + + + align:start position:0% +fricatives +obstreams yeah so um can be added to + + align:start position:0% +obstreams yeah so um can be added to + + + align:start position:0% +obstreams yeah so um can be added to +words ending and obstruents uh and it + + align:start position:0% +words ending and obstruents uh and it + + + align:start position:0% +words ending and obstruents uh and it +can't be added to two adjectives ending + + align:start position:0% +can't be added to two adjectives ending + + + align:start position:0% +can't be added to two adjectives ending +in sonorance yeah + + align:start position:0% +in sonorance yeah + + + align:start position:0% +in sonorance yeah +okay + + align:start position:0% +okay + + + align:start position:0% +okay +another place where it's useful to + + align:start position:0% +another place where it's useful to + + + align:start position:0% +another place where it's useful to +distinguish uh sonorants from uh + + align:start position:0% +distinguish uh sonorants from uh + + + align:start position:0% +distinguish uh sonorants from uh +obstruents polish plurals I think this + + align:start position:0% +obstruents polish plurals I think this + + + align:start position:0% +obstruents polish plurals I think this +is the last time I will say anything + + align:start position:0% +is the last time I will say anything + + + align:start position:0% +is the last time I will say anything +about polish plurals I can't promise + + align:start position:0% +about polish plurals I can't promise + + + align:start position:0% +about polish plurals I can't promise +because you know it's a very useful + + align:start position:0% +because you know it's a very useful + + + align:start position:0% +because you know it's a very useful +example but if you're getting tired of + + align:start position:0% +example but if you're getting tired of + + + align:start position:0% +example but if you're getting tired of +Polish plurals I apologize I think we're + + align:start position:0% +Polish plurals I apologize I think we're + + + align:start position:0% +Polish plurals I apologize I think we're +just about to the end on the other hand + + align:start position:0% +just about to the end on the other hand + + + align:start position:0% +just about to the end on the other hand +if you've become fond of Polish plurals + + align:start position:0% +if you've become fond of Polish plurals + + + align:start position:0% +if you've become fond of Polish plurals +please gaze at this this slide for a + + align:start position:0% +please gaze at this this slide for a + + + align:start position:0% +please gaze at this this slide for a +while you know because this is your last + + align:start position:0% +while you know because this is your last + + + align:start position:0% +while you know because this is your last +big chance + + align:start position:0% +big chance + + + align:start position:0% +big chance +um + + align:start position:0% +um + + + align:start position:0% +um +what we said about polish florals was + + align:start position:0% +what we said about polish florals was + + + align:start position:0% +what we said about polish florals was +that it's useful to say that there are + + align:start position:0% +that it's useful to say that there are + + + align:start position:0% +that it's useful to say that there are +words that end underlyingly in sounds + + align:start position:0% +words that end underlyingly in sounds + + + align:start position:0% +words that end underlyingly in sounds +like G and B and z and that those final + + align:start position:0% +like G and B and z and that those final + + + align:start position:0% +like G and B and z and that those final +sounds G and B and Z devoice when + + align:start position:0% +sounds G and B and Z devoice when + + + align:start position:0% +sounds G and B and Z devoice when +they're at the ends of words so + + align:start position:0% +they're at the ends of words so + + + align:start position:0% +they're at the ends of words so +underlying the word for lie becomes if + + align:start position:0% +underlying the word for lie becomes if + + + align:start position:0% +underlying the word for lie becomes if +you don't add anything to after it all + + align:start position:0% +you don't add anything to after it all + + + align:start position:0% +you don't add anything to after it all +right and same with the word for club + + align:start position:0% +right and same with the word for club + + + align:start position:0% +right and same with the word for club +and the word for Rubble and I have been + + align:start position:0% +and the word for Rubble and I have been + + + align:start position:0% +and the word for Rubble and I have been +in cautiously saying things like polish + + align:start position:0% +in cautiously saying things like polish + + + align:start position:0% +in cautiously saying things like polish +devoices its final consonants + + align:start position:0% +devoices its final consonants + + + align:start position:0% +devoices its final consonants +which was a lie I think I told you just + + align:start position:0% +which was a lie I think I told you just + + + align:start position:0% +which was a lie I think I told you just +now that I try not to lie to you any + + align:start position:0% +now that I try not to lie to you any + + + align:start position:0% +now that I try not to lie to you any +more than I have to + + align:start position:0% +more than I have to + + + align:start position:0% +more than I have to +um + + align:start position:0% +um + + + align:start position:0% +um +it doesn't devoice its final consonants + + align:start position:0% +it doesn't devoice its final consonants + + + align:start position:0% +it doesn't devoice its final consonants +right because uh polish has words like + + align:start position:0% +right because uh polish has words like + + + align:start position:0% +right because uh polish has words like +Dom which is the word for house and that + + align:start position:0% +Dom which is the word for house and that + + + align:start position:0% +Dom which is the word for house and that +ends in a voiced sound right Dom doesn't + + align:start position:0% +ends in a voiced sound right Dom doesn't + + + align:start position:0% +ends in a voiced sound right Dom doesn't +become Dom yeah + + align:start position:0% +become Dom yeah + + + align:start position:0% +become Dom yeah +right + + align:start position:0% +right + + + align:start position:0% +right +so it's not the case that final + + align:start position:0% +so it's not the case that final + + + align:start position:0% +so it's not the case that final +consonants become voiceless in Polish + + align:start position:0% +consonants become voiceless in Polish + + + align:start position:0% +consonants become voiceless in Polish +what are the things that become + + align:start position:0% +what are the things that become + + + align:start position:0% +what are the things that become +voiceless in Polish + + align:start position:0% + + + + align:start position:0% + +obstrands yeah stop centricatives yeah + + align:start position:0% +obstrands yeah stop centricatives yeah + + + align:start position:0% +obstrands yeah stop centricatives yeah +those are the things that become + + align:start position:0% +those are the things that become + + + align:start position:0% +those are the things that become +voiceless in Polish relatedly polish is + + align:start position:0% +voiceless in Polish relatedly polish is + + + align:start position:0% +voiceless in Polish relatedly polish is +like English in having voiced and + + align:start position:0% +like English in having voiced and + + + align:start position:0% +like English in having voiced and +voiceless obstruents but not in having + + align:start position:0% +voiceless obstruents but not in having + + + align:start position:0% +voiceless obstruents but not in having +voiced and not having voiced and + + align:start position:0% +voiced and not having voiced and + + + align:start position:0% +voiced and not having voiced and +voiceless honorings uh polish you know + + align:start position:0% +voiceless honorings uh polish you know + + + align:start position:0% +voiceless honorings uh polish you know +the m in a sense doesn't have anywhere + + align:start position:0% +the m in a sense doesn't have anywhere + + + align:start position:0% +the m in a sense doesn't have anywhere +to go + + align:start position:0% +to go + + + align:start position:0% +to go +polish doesn't have that sound + + align:start position:0% + + + + align:start position:0% + +common situation so it's really final + + align:start position:0% +common situation so it's really final + + + align:start position:0% +common situation so it's really final +obstruents that are becoming voiceless + + align:start position:0% + + + + align:start position:0% + +okay all right so that's that's that's a + + align:start position:0% +okay all right so that's that's that's a + + + align:start position:0% +okay all right so that's that's that's a +reason to want to care about the + + align:start position:0% +reason to want to care about the + + + align:start position:0% +reason to want to care about the +distinction between sunrings and + + align:start position:0% +distinction between sunrings and + + + align:start position:0% +distinction between sunrings and +obstrids uh not just because you want to + + align:start position:0% +obstrids uh not just because you want to + + + align:start position:0% +obstrids uh not just because you want to +understand why it's white and darkened + + align:start position:0% +understand why it's white and darkened + + + align:start position:0% +understand why it's white and darkened +and lessened but not yellowing yeah + + align:start position:0% +and lessened but not yellowing yeah + + + align:start position:0% +and lessened but not yellowing yeah +uh it seems to be a distinction that + + align:start position:0% +uh it seems to be a distinction that + + + align:start position:0% +uh it seems to be a distinction that +cares about sonorants and obstruents + + align:start position:0% +cares about sonorants and obstruents + + + align:start position:0% +cares about sonorants and obstruents +here's another one uh polish which as + + align:start position:0% +here's another one uh polish which as + + + align:start position:0% +here's another one uh polish which as +I've said now several times and I think + + align:start position:0% +I've said now several times and I think + + + align:start position:0% +I've said now several times and I think +this might be the last time uh polish is + + align:start position:0% +this might be the last time uh polish is + + + align:start position:0% +this might be the last time uh polish is +doing something that is very common in + + align:start position:0% +doing something that is very common in + + + align:start position:0% +doing something that is very common in +languages of the world it's devoicing + + align:start position:0% +languages of the world it's devoicing + + + align:start position:0% +languages of the world it's devoicing +final obstrands + + align:start position:0% +final obstrands + + + align:start position:0% +final obstrands +um uh uh that's a that's a thing that + + align:start position:0% +um uh uh that's a that's a thing that + + + align:start position:0% +um uh uh that's a that's a thing that +happens a lot + + align:start position:0% + + + + align:start position:0% + +all right so + + align:start position:0% +all right so + + + align:start position:0% +all right so +um phonology so far we've been doing + + align:start position:0% +um phonology so far we've been doing + + + align:start position:0% +um phonology so far we've been doing +phenology for a couple days now uh it's + + align:start position:0% +phenology for a couple days now uh it's + + + align:start position:0% +phenology for a couple days now uh it's +useful to think of sounds as undergoing + + align:start position:0% +useful to think of sounds as undergoing + + + align:start position:0% +useful to think of sounds as undergoing +changes uh sometimes uh driven by sounds + + align:start position:0% +changes uh sometimes uh driven by sounds + + + align:start position:0% +changes uh sometimes uh driven by sounds +coming in contact with each other + + align:start position:0% +coming in contact with each other + + + align:start position:0% +coming in contact with each other +um and we can describe these changes in + + align:start position:0% +um and we can describe these changes in + + + align:start position:0% +um and we can describe these changes in +terms of rules here's the formalism for + + align:start position:0% +terms of rules here's the formalism for + + + align:start position:0% +terms of rules here's the formalism for +rules that I've been showing you uh so + + align:start position:0% +rules that I've been showing you uh so + + + align:start position:0% +rules that I've been showing you uh so +we'll say you know sound a changes into + + align:start position:0% +we'll say you know sound a changes into + + + align:start position:0% +we'll say you know sound a changes into +sound B the slash introduces you to the + + align:start position:0% +sound B the slash introduces you to the + + + align:start position:0% +sound B the slash introduces you to the +environment this is a description of + + align:start position:0% +environment this is a description of + + + align:start position:0% +environment this is a description of +what's happening in Polish and Turkish + + align:start position:0% +what's happening in Polish and Turkish + + + align:start position:0% +what's happening in Polish and Turkish +and German Russian lots of other + + align:start position:0% +and German Russian lots of other + + + align:start position:0% +and German Russian lots of other +languages uh final obstruents so if you + + align:start position:0% +languages uh final obstruents so if you + + + align:start position:0% +languages uh final obstruents so if you +are an obstrom that is something which + + align:start position:0% +are an obstrom that is something which + + + align:start position:0% +are an obstrom that is something which +is now the sonorant you become something + + align:start position:0% +is now the sonorant you become something + + + align:start position:0% +is now the sonorant you become something +which is not voiced if you are at the + + align:start position:0% +which is not voiced if you are at the + + + align:start position:0% +which is not voiced if you are at the +end of a word that environment + + align:start position:0% +end of a word that environment + + + align:start position:0% +end of a word that environment +description is the way to write at the + + align:start position:0% +description is the way to write at the + + + align:start position:0% +description is the way to write at the +end of a word that hash symbol is the + + align:start position:0% +end of a word that hash symbol is the + + + align:start position:0% +end of a word that hash symbol is the +symbol for a boundary between words and + + align:start position:0% +symbol for a boundary between words and + + + align:start position:0% +symbol for a boundary between words and +and the underscore is where the change + + align:start position:0% +and the underscore is where the change + + + align:start position:0% +and the underscore is where the change +takes place so this rule says this + + align:start position:0% +takes place so this rule says this + + + align:start position:0% +takes place so this rule says this +change happens uh when the sound is + + align:start position:0% +change happens uh when the sound is + + + align:start position:0% +change happens uh when the sound is +before a word boundary or if there's + + align:start position:0% +before a word boundary or if there's + + + align:start position:0% +before a word boundary or if there's +another way when it is at the end of a + + align:start position:0% +another way when it is at the end of a + + + align:start position:0% +another way when it is at the end of a +word + + align:start position:0% +word + + + align:start position:0% +word +does that make sense this is a way of + + align:start position:0% +does that make sense this is a way of + + + align:start position:0% +does that make sense this is a way of +writing rules + + align:start position:0% +writing rules + + + align:start position:0% +writing rules +um + + align:start position:0% +um + + + align:start position:0% +um +these rules are part of our knowledge of + + align:start position:0% +these rules are part of our knowledge of + + + align:start position:0% +these rules are part of our knowledge of +a language so you know we've talked + + align:start position:0% +a language so you know we've talked + + + align:start position:0% +a language so you know we've talked +about this uh + + align:start position:0% +about this uh + + + align:start position:0% +about this uh +uh + + align:start position:0% +uh + + + align:start position:0% +uh +as adults uh all of anybody who is a + + align:start position:0% +as adults uh all of anybody who is a + + + align:start position:0% +as adults uh all of anybody who is a +native speaker of English knows how to + + align:start position:0% +native speaker of English knows how to + + + align:start position:0% +native speaker of English knows how to +make the plural of wug or how to make + + align:start position:0% +make the plural of wug or how to make + + + align:start position:0% +make the plural of wug or how to make +the plural of Bach even so uh how to + + align:start position:0% +the plural of Bach even so uh how to + + + align:start position:0% +the plural of Bach even so uh how to +make plurals of words you've never heard + + align:start position:0% +make plurals of words you've never heard + + + align:start position:0% +make plurals of words you've never heard +before and even words that end in sounds + + align:start position:0% +before and even words that end in sounds + + + align:start position:0% +before and even words that end in sounds +that your language doesn't have right + + align:start position:0% +that your language doesn't have right + + + align:start position:0% +that your language doesn't have right +so if I insist on calling the composer + + align:start position:0% +so if I insist on calling the composer + + + align:start position:0% +so if I insist on calling the composer +Bach if I insist on the original + + align:start position:0% +Bach if I insist on the original + + + align:start position:0% +Bach if I insist on the original +pronunciation of the word kayak which is + + align:start position:0% +pronunciation of the word kayak which is + + + align:start position:0% +pronunciation of the word kayak which is +you know kayaka a single-person vote + + align:start position:0% +you know kayaka a single-person vote + + + align:start position:0% +you know kayaka a single-person vote +which in in yupiak begins and ends with + + align:start position:0% +which in in yupiak begins and ends with + + + align:start position:0% +which in in yupiak begins and ends with +a uvular stop so if I'm trying to + + align:start position:0% +a uvular stop so if I'm trying to + + + align:start position:0% +a uvular stop so if I'm trying to +impress you with my ability to make + + align:start position:0% +impress you with my ability to make + + + align:start position:0% +impress you with my ability to make +uvular stops and I insist on calling a + + align:start position:0% +uvular stops and I insist on calling a + + + align:start position:0% +uvular stops and I insist on calling a +kayak a kayak then my plural for it is + + align:start position:0% +kayak a kayak then my plural for it is + + + align:start position:0% +kayak a kayak then my plural for it is +going to be kayaks right so I'm going to + + align:start position:0% +going to be kayaks right so I'm going to + + + align:start position:0% +going to be kayaks right so I'm going to +add an S sound I'm going to devoice it + + align:start position:0% +add an S sound I'm going to devoice it + + + align:start position:0% +add an S sound I'm going to devoice it +because that uvular stop although it's a + + align:start position:0% +because that uvular stop although it's a + + + align:start position:0% +because that uvular stop although it's a +sound we don't have in English it's + + align:start position:0% +sound we don't have in English it's + + + align:start position:0% +sound we don't have in English it's +voiceless and so we're going to devoice + + align:start position:0% +voiceless and so we're going to devoice + + + align:start position:0% +voiceless and so we're going to devoice +uh do voice after it yeah uh so these + + align:start position:0% +uh do voice after it yeah uh so these + + + align:start position:0% +uh do voice after it yeah uh so these +rules are part of our knowledge of a + + align:start position:0% +rules are part of our knowledge of a + + + align:start position:0% +rules are part of our knowledge of a +language and we can apply them to uh + + align:start position:0% +language and we can apply them to uh + + + align:start position:0% +language and we can apply them to uh +unfamiliar problems unfamiliar words and + + align:start position:0% +unfamiliar problems unfamiliar words and + + + align:start position:0% +unfamiliar problems unfamiliar words and +even unfamiliar sounds + + align:start position:0% +even unfamiliar sounds + + + align:start position:0% +even unfamiliar sounds +um and I've now tried to convince you + + align:start position:0% +um and I've now tried to convince you + + + align:start position:0% +um and I've now tried to convince you +the best way to State these rules + + align:start position:0% +the best way to State these rules + + + align:start position:0% +the best way to State these rules +sometimes at least is in terms of + + align:start position:0% +sometimes at least is in terms of + + + align:start position:0% +sometimes at least is in terms of +features that is + + align:start position:0% +features that is + + + align:start position:0% +features that is +um we don't just want to list the sounds + + align:start position:0% +um we don't just want to list the sounds + + + align:start position:0% +um we don't just want to list the sounds +that undergo a change we want to have + + align:start position:0% +that undergo a change we want to have + + + align:start position:0% +that undergo a change we want to have +these features which are ways of + + align:start position:0% +these features which are ways of + + + align:start position:0% +these features which are ways of +capturing sets of sounds we we think + + align:start position:0% +capturing sets of sounds we we think + + + align:start position:0% +capturing sets of sounds we we think +that there are natural classes of sounds + + align:start position:0% +that there are natural classes of sounds + + + align:start position:0% +that there are natural classes of sounds +that undergo particular changes so there + + align:start position:0% +that undergo particular changes so there + + + align:start position:0% +that undergo particular changes so there +are sound changes that apply say to + + align:start position:0% +are sound changes that apply say to + + + align:start position:0% +are sound changes that apply say to +obstruents to tolerance or to vowels or + + align:start position:0% +obstruents to tolerance or to vowels or + + + align:start position:0% +obstruents to tolerance or to vowels or +to voice sounds or to voiceless sounds + + align:start position:0% +to voice sounds or to voiceless sounds + + + align:start position:0% +to voice sounds or to voiceless sounds +we're not just going to list the sounds + + align:start position:0% +we're not just going to list the sounds + + + align:start position:0% +we're not just going to list the sounds +that undergo sound changes we're gonna + + align:start position:0% +that undergo sound changes we're gonna + + + align:start position:0% +that undergo sound changes we're gonna +we're gonna State these uh in terms of + + align:start position:0% +we're gonna State these uh in terms of + + + align:start position:0% +we're gonna State these uh in terms of +features okay + + align:start position:0% + + + + align:start position:0% + +all right + + align:start position:0% +all right + + + align:start position:0% +all right +and then the other thing that I've + + align:start position:0% +and then the other thing that I've + + + align:start position:0% +and then the other thing that I've +introduced you to is the idea that at + + align:start position:0% +introduced you to is the idea that at + + + align:start position:0% +introduced you to is the idea that at +least sometimes + + align:start position:0% +least sometimes + + + align:start position:0% +least sometimes +it's fruitful to model these as these + + align:start position:0% +it's fruitful to model these as these + + + align:start position:0% +it's fruitful to model these as these +kinds of sound changes as involving uh + + align:start position:0% +kinds of sound changes as involving uh + + + align:start position:0% +kinds of sound changes as involving uh +ranked constraints this was the the + + align:start position:0% +ranked constraints this was the the + + + align:start position:0% +ranked constraints this was the the +optimality theory tableaus uh that is to + + align:start position:0% +optimality theory tableaus uh that is to + + + align:start position:0% +optimality theory tableaus uh that is to +imagine that languages have a list of + + align:start position:0% +imagine that languages have a list of + + + align:start position:0% +imagine that languages have a list of +things that they are trying to achieve + + align:start position:0% +things that they are trying to achieve + + + align:start position:0% +things that they are trying to achieve +and it's a list that's ranked in order + + align:start position:0% +and it's a list that's ranked in order + + + align:start position:0% +and it's a list that's ranked in order +of priority + + align:start position:0% +of priority + + + align:start position:0% +of priority +and you get to observe the interplay + + align:start position:0% +and you get to observe the interplay + + + align:start position:0% +and you get to observe the interplay +between these different priorities uh in + + align:start position:0% +between these different priorities uh in + + + align:start position:0% +between these different priorities uh in +certain kinds of complicated cases uh + + align:start position:0% +certain kinds of complicated cases uh + + + align:start position:0% +certain kinds of complicated cases uh +the the Japanese accent case was one of + + align:start position:0% +the the Japanese accent case was one of + + + align:start position:0% +the the Japanese accent case was one of +the ones that we looked at + + align:start position:0% +the ones that we looked at + + + align:start position:0% +the ones that we looked at +okay + + align:start position:0% + + + + align:start position:0% + +and I think that's it for this review + + align:start position:0% +and I think that's it for this review + + + align:start position:0% +and I think that's it for this review +slide is there something else oh okay is + + align:start position:0% +slide is there something else oh okay is + + + align:start position:0% +slide is there something else oh okay is +everyone happy with all of this is there + + align:start position:0% +everyone happy with all of this is there + + + align:start position:0% +everyone happy with all of this is there +any of this that people are looking at + + align:start position:0% +any of this that people are looking at + + + align:start position:0% +any of this that people are looking at +and going no wait how did how did we see + + align:start position:0% +and going no wait how did how did we see + + + align:start position:0% +and going no wait how did how did we see +that or what does that mean or anything + + align:start position:0% +that or what does that mean or anything + + + align:start position:0% +that or what does that mean or anything +like that it's an attempt to make sure + + align:start position:0% +like that it's an attempt to make sure + + + align:start position:0% +like that it's an attempt to make sure +we're all + + align:start position:0% +we're all + + + align:start position:0% +we're all +in the same ballpark here yeah + + align:start position:0% +in the same ballpark here yeah + + + align:start position:0% +in the same ballpark here yeah +oh all I mean by feature are uh things + + align:start position:0% +oh all I mean by feature are uh things + + + align:start position:0% +oh all I mean by feature are uh things +like voiced or sonorant or you know + + align:start position:0% +like voiced or sonorant or you know + + + align:start position:0% +like voiced or sonorant or you know +those kinds of things yeah good question + + align:start position:0% +those kinds of things yeah good question + + + align:start position:0% +those kinds of things yeah good question +um and a standard way to write rules + + align:start position:0% +um and a standard way to write rules + + + align:start position:0% +um and a standard way to write rules +involves putting features in Brackets + + align:start position:0% +involves putting features in Brackets + + + align:start position:0% +involves putting features in Brackets +like that so you know the fancy way to + + align:start position:0% +like that so you know the fancy way to + + + align:start position:0% +like that so you know the fancy way to +say something is voiceless is to say + + align:start position:0% +say something is voiceless is to say + + + align:start position:0% +say something is voiceless is to say +that it's its value for the feature + + align:start position:0% +that it's its value for the feature + + + align:start position:0% +that it's its value for the feature +voice is minus right so it is not voiced + + align:start position:0% +voice is minus right so it is not voiced + + + align:start position:0% +voice is minus right so it is not voiced +yeah that's all that means + + align:start position:0% +yeah that's all that means + + + align:start position:0% +yeah that's all that means +yeah yeah + + align:start position:0% +yeah yeah + + + align:start position:0% +yeah yeah +okay when we ask you to do phonology we + + align:start position:0% +okay when we ask you to do phonology we + + + align:start position:0% +okay when we ask you to do phonology we +will tell you whether we want you to + + align:start position:0% +will tell you whether we want you to + + + align:start position:0% +will tell you whether we want you to +what extent we want you to be formal + + align:start position:0% +what extent we want you to be formal + + + align:start position:0% +what extent we want you to be formal +about how you write your rules yeah so I + + align:start position:0% +about how you write your rules yeah so I + + + align:start position:0% +about how you write your rules yeah so I +think the problem set that I just send + + align:start position:0% +think the problem set that I just send + + + align:start position:0% +think the problem set that I just send +out uh asks you to look around for + + align:start position:0% +out uh asks you to look around for + + + align:start position:0% +out uh asks you to look around for +possible rules in your in the + + align:start position:0% +possible rules in your in the + + + align:start position:0% +possible rules in your in the +what is it it's a green Landing data I + + align:start position:0% +what is it it's a green Landing data I + + + align:start position:0% +what is it it's a green Landing data I +think + + align:start position:0% +think + + + align:start position:0% +think +um uh you don't have to sweat this level + + align:start position:0% +um uh you don't have to sweat this level + + + align:start position:0% +um uh you don't have to sweat this level +of formality in your rules so if your + + align:start position:0% +of formality in your rules so if your + + + align:start position:0% +of formality in your rules so if your +rule for that problem said so if you + + align:start position:0% +rule for that problem said so if you + + + align:start position:0% +rule for that problem said so if you +think you've figured out what's going on + + align:start position:0% +think you've figured out what's going on + + + align:start position:0% +think you've figured out what's going on +you can just tell us more or less + + align:start position:0% +you can just tell us more or less + + + align:start position:0% +you can just tell us more or less +don't feel like we're going to count off + + align:start position:0% +don't feel like we're going to count off + + + align:start position:0% +don't feel like we're going to count off +for not using features or not not + + align:start position:0% +for not using features or not not + + + align:start position:0% +for not using features or not not +writing your rules this way + + align:start position:0% + + + + align:start position:0% + +all right then + + align:start position:0% +all right then + + + align:start position:0% +all right then +now I told you just now + + align:start position:0% +now I told you just now + + + align:start position:0% +now I told you just now +tried to convince you earlier that there + + align:start position:0% +tried to convince you earlier that there + + + align:start position:0% +tried to convince you earlier that there +are cases where uh the Japanese accent + + align:start position:0% +are cases where uh the Japanese accent + + + align:start position:0% +are cases where uh the Japanese accent +case was the one that we spent the most + + align:start position:0% +case was the one that we spent the most + + + align:start position:0% +case was the one that we spent the most +time on where uh it's sort of fruitful + + align:start position:0% +time on where uh it's sort of fruitful + + + align:start position:0% +time on where uh it's sort of fruitful +to think of the phenomenon as involving + + align:start position:0% +to think of the phenomenon as involving + + + align:start position:0% +to think of the phenomenon as involving +a bunch of ranked priorities a bunch of + + align:start position:0% +a bunch of ranked priorities a bunch of + + + align:start position:0% +a bunch of ranked priorities a bunch of +constraints that are all pulling in + + align:start position:0% +constraints that are all pulling in + + + align:start position:0% +constraints that are all pulling in +different directions and you sort of + + align:start position:0% +different directions and you sort of + + + align:start position:0% +different directions and you sort of +solve that problem by deciding which is + + align:start position:0% +solve that problem by deciding which is + + + align:start position:0% +solve that problem by deciding which is +the most important one + + align:start position:0% +the most important one + + + align:start position:0% +the most important one +uh which ones are more important than + + align:start position:0% +uh which ones are more important than + + + align:start position:0% +uh which ones are more important than +which other ones ranking your various + + align:start position:0% +which other ones ranking your various + + + align:start position:0% +which other ones ranking your various +constraints with respect to each other + + align:start position:0% +constraints with respect to each other + + + align:start position:0% +constraints with respect to each other +there are other cases though uh that are + + align:start position:0% +there are other cases though uh that are + + + align:start position:0% +there are other cases though uh that are +uh problematic for that way of thinking + + align:start position:0% +uh problematic for that way of thinking + + + align:start position:0% +uh problematic for that way of thinking +about things uh and there's a sort of + + align:start position:0% +about things uh and there's a sort of + + + align:start position:0% +about things uh and there's a sort of +big literature on trying to reconcile + + align:start position:0% +big literature on trying to reconcile + + + align:start position:0% +big literature on trying to reconcile +these kinds of observations on the one + + align:start position:0% +these kinds of observations on the one + + + align:start position:0% +these kinds of observations on the one +hand uh the observation that there do + + align:start position:0% +hand uh the observation that there do + + + align:start position:0% +hand uh the observation that there do +seem to be these conspiracies where a + + align:start position:0% +seem to be these conspiracies where a + + + align:start position:0% +seem to be these conspiracies where a +language is doing the same thing in a + + align:start position:0% +language is doing the same thing in a + + + align:start position:0% +language is doing the same thing in a +variety of ways which is the kind of + + align:start position:0% +variety of ways which is the kind of + + + align:start position:0% +variety of ways which is the kind of +thing that makes people want to think in + + align:start position:0% +thing that makes people want to think in + + + align:start position:0% +thing that makes people want to think in +terms of running to constraints and on + + align:start position:0% +terms of running to constraints and on + + + align:start position:0% +terms of running to constraints and on +the other hand the kinds of cases which + + align:start position:0% +the other hand the kinds of cases which + + + align:start position:0% +the other hand the kinds of cases which +we've talked about before where it looks + + align:start position:0% +we've talked about before where it looks + + + align:start position:0% +we've talked about before where it looks +more like what's happening is that you + + align:start position:0% +more like what's happening is that you + + + align:start position:0% +more like what's happening is that you +have a bunch of rules and they're + + align:start position:0% +have a bunch of rules and they're + + + align:start position:0% +have a bunch of rules and they're +applying in an order uh and you they + + align:start position:0% +applying in an order uh and you they + + + align:start position:0% +applying in an order uh and you they +they don't necessarily all get + + align:start position:0% +they don't necessarily all get + + + align:start position:0% +they don't necessarily all get +um get obeyed we did this on the board + + align:start position:0% +um get obeyed we did this on the board + + + align:start position:0% +um get obeyed we did this on the board +um when was it last time I think but + + align:start position:0% +um when was it last time I think but + + + align:start position:0% +um when was it last time I think but +let's let's do it on the slide a little + + align:start position:0% +let's let's do it on the slide a little + + + align:start position:0% +let's let's do it on the slide a little +more carefully so cast your minds back + + align:start position:0% +more carefully so cast your minds back + + + align:start position:0% +more carefully so cast your minds back +to when we were talking about Lardo I + + align:start position:0% +to when we were talking about Lardo I + + + align:start position:0% +to when we were talking about Lardo I +tried to convince you we worked out an + + align:start position:0% +tried to convince you we worked out an + + + align:start position:0% +tried to convince you we worked out an +analysis of Lardo + + align:start position:0% +analysis of Lardo + + + align:start position:0% +analysis of Lardo +in which again uh Bearer nominative + + align:start position:0% +in which again uh Bearer nominative + + + align:start position:0% +in which again uh Bearer nominative +singular lardol doesn't Mark number but + + align:start position:0% +singular lardol doesn't Mark number but + + + align:start position:0% +singular lardol doesn't Mark number but +uh bare nominative forms of uh nouns + + align:start position:0% +uh bare nominative forms of uh nouns + + + align:start position:0% +uh bare nominative forms of uh nouns +um undergo various kinds of sound + + align:start position:0% +um undergo various kinds of sound + + + align:start position:0% +um undergo various kinds of sound +changes so lardel has words that + + align:start position:0% +changes so lardel has words that + + + align:start position:0% +changes so lardel has words that +underlyingly end in a k for example and + + align:start position:0% +underlyingly end in a k for example and + + + align:start position:0% +underlyingly end in a k for example and +there was a a general rule in lardel + + align:start position:0% +there was a a general rule in lardel + + + align:start position:0% +there was a a general rule in lardel +that said uh if you have a word that + + align:start position:0% +that said uh if you have a word that + + + align:start position:0% +that said uh if you have a word that +ends in a k get rid of the K you know so + + align:start position:0% +ends in a k get rid of the K you know so + + + align:start position:0% +ends in a k get rid of the K you know so +I'll start writing these down uh some + + align:start position:0% +I'll start writing these down uh some + + + align:start position:0% +I'll start writing these down uh some +marital rules one of them was uh + + align:start position:0% +marital rules one of them was uh + + + align:start position:0% +marital rules one of them was uh +eliminate and I won't try to write them + + align:start position:0% +eliminate and I won't try to write them + + + align:start position:0% +eliminate and I won't try to write them +formally eliminate finally + + align:start position:0% +formally eliminate finally + + + align:start position:0% +formally eliminate finally +okay so the word that we think is + + align:start position:0% +okay so the word that we think is + + + align:start position:0% +okay so the word that we think is +underlying out the word for Boomerang uh + + align:start position:0% +underlying out the word for Boomerang uh + + + align:start position:0% +underlying out the word for Boomerang uh +in Islam and the form is the reason we + + align:start position:0% +in Islam and the form is the reason we + + + align:start position:0% +in Islam and the form is the reason we +think that it's underlying liuang is + + align:start position:0% +think that it's underlying liuang is + + + align:start position:0% +think that it's underlying liuang is +that if you add any suffixes to it you + + align:start position:0% +that if you add any suffixes to it you + + + align:start position:0% +that if you add any suffixes to it you +you get to see that K so the accusative + + align:start position:0% +you get to see that K so the accusative + + + align:start position:0% +you get to see that K so the accusative +I think I told you was + + align:start position:0% +I think I told you was + + + align:start position:0% +I think I told you was +um uh so you know the K shows up uh in + + align:start position:0% +um uh so you know the K shows up uh in + + + align:start position:0% +um uh so you know the K shows up uh in +and in other forms as well + + align:start position:0% +and in other forms as well + + + align:start position:0% +and in other forms as well +we thought there was another rule that + + align:start position:0% +we thought there was another rule that + + + align:start position:0% +we thought there was another rule that +said uh final + + align:start position:0% +said uh final + + + align:start position:0% +said uh final +U becomes ah + + align:start position:0% +U becomes ah + + + align:start position:0% +U becomes ah +uh and that was why uh gandu which is + + align:start position:0% +uh and that was why uh gandu which is + + + align:start position:0% +uh and that was why uh gandu which is +the word for blood uh underlyingly + + align:start position:0% +the word for blood uh underlyingly + + + align:start position:0% +the word for blood uh underlyingly +becomes Kanda uh in the nominative and + + align:start position:0% +becomes Kanda uh in the nominative and + + + align:start position:0% +becomes Kanda uh in the nominative and +in the excuse + + align:start position:0% +in the excuse + + + align:start position:0% +in the excuse +why we think it starts out as gandu + + align:start position:0% +why we think it starts out as gandu + + + align:start position:0% +why we think it starts out as gandu +um so we have these two rules and what + + align:start position:0% +um so we have these two rules and what + + + align:start position:0% +um so we have these two rules and what +we said when we were doing Laredo before + + align:start position:0% +we said when we were doing Laredo before + + + align:start position:0% +we said when we were doing Laredo before +was something like uh we might want + + align:start position:0% +was something like uh we might want + + + align:start position:0% +was something like uh we might want +these rules to apply in a particular + + align:start position:0% +these rules to apply in a particular + + + align:start position:0% +these rules to apply in a particular +order uh in fact I see that I have + + align:start position:0% +order uh in fact I see that I have + + + align:start position:0% +order uh in fact I see that I have +written them in the wrong order + + align:start position:0% +written them in the wrong order + + + align:start position:0% +written them in the wrong order +um if you were to uh take the word nalok + + align:start position:0% +um if you were to uh take the word nalok + + + align:start position:0% +um if you were to uh take the word nalok +which is the underlying form for story + + align:start position:0% +which is the underlying form for story + + + align:start position:0% +which is the underlying form for story +and apply this Rule and then this rule + + align:start position:0% +and apply this Rule and then this rule + + + align:start position:0% +and apply this Rule and then this rule +well then you know you would eliminate + + align:start position:0% +well then you know you would eliminate + + + align:start position:0% +well then you know you would eliminate +the final K that would get you Malu and + + align:start position:0% +the final K that would get you Malu and + + + align:start position:0% +the final K that would get you Malu and +then you would change the final uh + + align:start position:0% +then you would change the final uh + + + align:start position:0% +then you would change the final uh +but that's not in fact the nominative + + align:start position:0% +but that's not in fact the nominative + + + align:start position:0% +but that's not in fact the nominative +form for story The nominative form for + + align:start position:0% +form for story The nominative form for + + + align:start position:0% +form for story The nominative form for +story is yeah and so what I said at the + + align:start position:0% +story is yeah and so what I said at the + + + align:start position:0% +story is yeah and so what I said at the +time was one way of thinking about this + + align:start position:0% +time was one way of thinking about this + + + align:start position:0% +time was one way of thinking about this +a popular way of thinking about this is + + align:start position:0% +a popular way of thinking about this is + + + align:start position:0% +a popular way of thinking about this is +to think there are these rules and it's + + align:start position:0% +to think there are these rules and it's + + + align:start position:0% +to think there are these rules and it's +like an assembly line you know there's + + align:start position:0% +like an assembly line you know there's + + + align:start position:0% +like an assembly line you know there's +first the first station is the one where + + align:start position:0% +first the first station is the one where + + + align:start position:0% +first the first station is the one where +you do this where you get rid of final + + align:start position:0% +you do this where you get rid of final + + + align:start position:0% +you do this where you get rid of final +ooh and then after you're done with that + + align:start position:0% +ooh and then after you're done with that + + + align:start position:0% +ooh and then after you're done with that +you get handed off to another another + + align:start position:0% +you get handed off to another another + + + align:start position:0% +you get handed off to another another +place in the assembly line where they + + align:start position:0% +place in the assembly line where they + + + align:start position:0% +place in the assembly line where they +eliminate final K and what's happened + + align:start position:0% +eliminate final K and what's happened + + + align:start position:0% +eliminate final K and what's happened +with underlying is that it got handed to + + align:start position:0% +with underlying is that it got handed to + + + align:start position:0% +with underlying is that it got handed to +the first station first first station + + align:start position:0% +the first station first first station + + + align:start position:0% +the first station first first station +said well this word and I look it + + align:start position:0% +said well this word and I look it + + + align:start position:0% +said well this word and I look it +doesn't end in ooh I'm not going to do + + align:start position:0% +doesn't end in ooh I'm not going to do + + + align:start position:0% +doesn't end in ooh I'm not going to do +anything and then it gets handed to the + + align:start position:0% +anything and then it gets handed to the + + + align:start position:0% +anything and then it gets handed to the +second station the second station says + + align:start position:0% +second station the second station says + + + align:start position:0% +second station the second station says +oh I need to get rid of the final K + + align:start position:0% +oh I need to get rid of the final K + + + align:start position:0% +oh I need to get rid of the final K +it'll be Yeah by which point the people + + align:start position:0% +it'll be Yeah by which point the people + + + align:start position:0% +it'll be Yeah by which point the people +in the first station might have been + + align:start position:0% +in the first station might have been + + + align:start position:0% +in the first station might have been +saying wait wait let us have that back + + align:start position:0% +saying wait wait let us have that back + + + align:start position:0% +saying wait wait let us have that back +but it's too late it was the idea yes + + align:start position:0% +but it's too late it was the idea yes + + + align:start position:0% +but it's too late it was the idea yes +these are rules that apply in a + + align:start position:0% +these are rules that apply in a + + + align:start position:0% +these are rules that apply in a +particular order that's the way we were + + align:start position:0% +particular order that's the way we were + + + align:start position:0% +particular order that's the way we were +talking about lairdo + + align:start position:0% +talking about lairdo + + + align:start position:0% +talking about lairdo +does that all sound Vaguely Familiar no + + align:start position:0% +does that all sound Vaguely Familiar no + + + align:start position:0% +does that all sound Vaguely Familiar no +that there are these procedures and the + + align:start position:0% +that there are these procedures and the + + + align:start position:0% +that there are these procedures and the +procedures happen in an order + + align:start position:0% + + + + align:start position:0% + +but if we imagine thinking about things + + align:start position:0% +but if we imagine thinking about things + + + align:start position:0% +but if we imagine thinking about things +in an optimality theoretic kind of way + + align:start position:0% +in an optimality theoretic kind of way + + + align:start position:0% +in an optimality theoretic kind of way +well it's not hard to come up with + + align:start position:0% +well it's not hard to come up with + + + align:start position:0% +well it's not hard to come up with +constraints right that say this you know + + align:start position:0% +constraints right that say this you know + + + align:start position:0% +constraints right that say this you know +uh star final + + align:start position:0% +uh star final + + + align:start position:0% +uh star final +I have to write it in capital letters + + align:start position:0% +I have to write it in capital letters + + + align:start position:0% +I have to write it in capital letters +because that's what you do in optimality + + align:start position:0% +because that's what you do in optimality + + + align:start position:0% +because that's what you do in optimality +theory uh no final k no final + + align:start position:0% +theory uh no final k no final + + + align:start position:0% +theory uh no final k no final +oh yeah + + align:start position:0% +oh yeah + + + align:start position:0% +oh yeah +um and those constraints would look at + + align:start position:0% +um and those constraints would look at + + + align:start position:0% +um and those constraints would look at +and I look uh sorry it went out and they + + align:start position:0% +and I look uh sorry it went out and they + + + align:start position:0% +and I look uh sorry it went out and they +would say no we can't have the final K + + align:start position:0% +would say no we can't have the final K + + + align:start position:0% +would say no we can't have the final K +it'll be one now and they would look at + + align:start position:0% +it'll be one now and they would look at + + + align:start position:0% +it'll be one now and they would look at +gandu and they would say no can't have + + align:start position:0% +gandu and they would say no can't have + + + align:start position:0% +gandu and they would say no can't have +the final ooh it'll be uh it's got to be + + align:start position:0% +the final ooh it'll be uh it's got to be + + + align:start position:0% +the final ooh it'll be uh it's got to be +Kanda uh it might have other constraints + + align:start position:0% +Kanda uh it might have other constraints + + + align:start position:0% +Kanda uh it might have other constraints +that are responsible for helping you + + align:start position:0% +that are responsible for helping you + + + align:start position:0% +that are responsible for helping you +decide you know the best thing to do + + align:start position:0% +decide you know the best thing to do + + + align:start position:0% +decide you know the best thing to do +with kandu is to change it to Kanda + + align:start position:0% +with kandu is to change it to Kanda + + + align:start position:0% +with kandu is to change it to Kanda +instead of you know Kandi or kand or any + + align:start position:0% +instead of you know Kandi or kand or any + + + align:start position:0% +instead of you know Kandi or kand or any +of the variety of other things you could + + align:start position:0% +of the variety of other things you could + + + align:start position:0% +of the variety of other things you could +have done so it's not all that hard to + + align:start position:0% +have done so it's not all that hard to + + + align:start position:0% +have done so it's not all that hard to +have constraints that say there's + + align:start position:0% +have constraints that say there's + + + align:start position:0% +have constraints that say there's +something wrong with one Oak there's + + align:start position:0% +something wrong with one Oak there's + + + align:start position:0% +something wrong with one Oak there's +something wrong with kandu + + align:start position:0% + + + + align:start position:0% + +but it's not easy to figure out what to + + align:start position:0% +but it's not easy to figure out what to + + + align:start position:0% +but it's not easy to figure out what to +do next and so if you have those + + align:start position:0% +do next and so if you have those + + + align:start position:0% +do next and so if you have those +conditions that say that adult cannot + + align:start position:0% +conditions that say that adult cannot + + + align:start position:0% +conditions that say that adult cannot +stand words that end in K or words that + + align:start position:0% +stand words that end in K or words that + + + align:start position:0% +stand words that end in K or words that +end in you + + align:start position:0% +end in you + + + align:start position:0% +end in you +um that's the kind of thing we were + + align:start position:0% +um that's the kind of thing we were + + + align:start position:0% +um that's the kind of thing we were +saying about you know Japanese accent + + align:start position:0% +saying about you know Japanese accent + + + align:start position:0% +saying about you know Japanese accent +Japanese doesn't like Accent on the last + + align:start position:0% +Japanese doesn't like Accent on the last + + + align:start position:0% +Japanese doesn't like Accent on the last +syllable so avoid it if you're making a + + align:start position:0% +syllable so avoid it if you're making a + + + align:start position:0% +syllable so avoid it if you're making a +compound + + align:start position:0% +compound + + + align:start position:0% +compound +those generalizations hold for + + align:start position:0% +those generalizations hold for + + + align:start position:0% +those generalizations hold for +boomeranging for blood but they don't + + align:start position:0% +boomeranging for blood but they don't + + + align:start position:0% +boomeranging for blood but they don't +hold for story the one about not having + + align:start position:0% +hold for story the one about not having + + + align:start position:0% +hold for story the one about not having +a word ending in ooh doesn't hold yes + + align:start position:0% + + + + align:start position:0% + +are optimality Theory yeah + + align:start position:0% + + + + align:start position:0% + +it is + + align:start position:0% + + + + align:start position:0% + +both like + + align:start position:0% +both like + + + align:start position:0% +both like +like if it were to do not a lot + + align:start position:0% +like if it were to do not a lot + + + align:start position:0% +like if it were to do not a lot +um + + align:start position:0% + + + + align:start position:0% + +Theory like + + align:start position:0% +Theory like + + + align:start position:0% +Theory like +certain words each + + align:start position:0% +certain words each + + + align:start position:0% +certain words each +so that's just it it doesn't right so + + align:start position:0% +so that's just it it doesn't right so + + + align:start position:0% +so that's just it it doesn't right so +the conditions + + align:start position:0% +the conditions + + + align:start position:0% +the conditions +um the sense in which it has something + + align:start position:0% +um the sense in which it has something + + + align:start position:0% +um the sense in which it has something +like an order is that the conditions are + + align:start position:0% +like an order is that the conditions are + + + align:start position:0% +like an order is that the conditions are +ranked with respect to each other + + align:start position:0% +ranked with respect to each other + + + align:start position:0% +ranked with respect to each other +there's the one that's most important + + align:start position:0% +there's the one that's most important + + + align:start position:0% +there's the one that's most important +and the one that's next most important + + align:start position:0% +and the one that's next most important + + + align:start position:0% +and the one that's next most important +and so on + + align:start position:0% +and so on + + + align:start position:0% +and so on +um but if we were to build a tableau + + align:start position:0% +um but if we were to build a tableau + + + align:start position:0% +um but if we were to build a tableau +right we would have these two conditions + + align:start position:0% +right we would have these two conditions + + + align:start position:0% +right we would have these two conditions +don't have final k + + align:start position:0% +don't have final k + + + align:start position:0% +don't have final k +don't have + + align:start position:0% +don't have + + + align:start position:0% +don't have +final + + align:start position:0% +final + + + align:start position:0% +final +oh + + align:start position:0% +oh + + + align:start position:0% +oh +um and we would start off with the look + + align:start position:0% +um and we would start off with the look + + + align:start position:0% +um and we would start off with the look +and we'd consider keeping a look + + align:start position:0% +and we'd consider keeping a look + + + align:start position:0% +and we'd consider keeping a look +and we'd consider getting rid of + + align:start position:0% +and we'd consider getting rid of + + + align:start position:0% +and we'd consider getting rid of +the K at the end and maybe we consider + + align:start position:0% +the K at the end and maybe we consider + + + align:start position:0% +the K at the end and maybe we consider +right and this one would get knocked out + + align:start position:0% +right and this one would get knocked out + + + align:start position:0% +right and this one would get knocked out +by star final K right because it would + + align:start position:0% +by star final K right because it would + + + align:start position:0% +by star final K right because it would +end in K and this one would get knocked + + align:start position:0% +end in K and this one would get knocked + + + align:start position:0% +end in K and this one would get knocked +out by star final ooh yeah and this one + + align:start position:0% +out by star final ooh yeah and this one + + + align:start position:0% +out by star final ooh yeah and this one +would pass both of those conditions + + align:start position:0% +would pass both of those conditions + + + align:start position:0% +would pass both of those conditions +so if we just did a tableau like this if + + align:start position:0% +so if we just did a tableau like this if + + + align:start position:0% +so if we just did a tableau like this if +we said you know lardel seems to not + + align:start position:0% +we said you know lardel seems to not + + + align:start position:0% +we said you know lardel seems to not +like this and not like that and we have + + align:start position:0% +like this and not like that and we have + + + align:start position:0% +like this and not like that and we have +evidence for that in these other cases + + align:start position:0% +evidence for that in these other cases + + + align:start position:0% +evidence for that in these other cases +it seems as though + + align:start position:0% +it seems as though + + + align:start position:0% +it seems as though +but that's wrong yeah so the fact is + + align:start position:0% +but that's wrong yeah so the fact is + + + align:start position:0% +but that's wrong yeah so the fact is +this is the one we want to win and it's + + align:start position:0% +this is the one we want to win and it's + + + align:start position:0% +this is the one we want to win and it's +hard to see how once we've posited these + + align:start position:0% +hard to see how once we've posited these + + + align:start position:0% +hard to see how once we've posited these +conditions how we can get this to win + + align:start position:0% +conditions how we can get this to win + + + align:start position:0% +conditions how we can get this to win +this seems like it ought to be better + + align:start position:0% +this seems like it ought to be better + + + align:start position:0% +this seems like it ought to be better +once we posited these conditions so the + + align:start position:0% +once we posited these conditions so the + + + align:start position:0% +once we posited these conditions so the +puzzle and there's something people work + + align:start position:0% +puzzle and there's something people work + + + align:start position:0% +puzzle and there's something people work +on just try to figure out why why is + + align:start position:0% +on just try to figure out why why is + + + align:start position:0% +on just try to figure out why why is +that second one better than the third + + align:start position:0% +that second one better than the third + + + align:start position:0% +that second one better than the third +one + + align:start position:0% +one + + + align:start position:0% +one +yeah how about we rephrase yeah + + align:start position:0% + + + + align:start position:0% + +okay so we could have a rule that says + + align:start position:0% +okay so we could have a rule that says + + + align:start position:0% +okay so we could have a rule that says +that's nice we could say no final oh + + align:start position:0% +that's nice we could say no final oh + + + align:start position:0% +that's nice we could say no final oh +this is another way of saying what you + + align:start position:0% +this is another way of saying what you + + + align:start position:0% +this is another way of saying what you +just said uh no final ooh that was final + + align:start position:0% +just said uh no final ooh that was final + + + align:start position:0% +just said uh no final ooh that was final +in original form + + align:start position:0% + + + + align:start position:0% + +yep so we need more capital letters but + + align:start position:0% +yep so we need more capital letters but + + + align:start position:0% +yep so we need more capital letters but +it's okay so yes if we if we state it + + align:start position:0% +it's okay so yes if we if we state it + + + align:start position:0% +it's okay so yes if we if we state it +that way + + align:start position:0% +that way + + + align:start position:0% +that way +um then uh + + align:start position:0% +um then uh + + + align:start position:0% +um then uh +um this passes that version of it + + align:start position:0% +um this passes that version of it + + + align:start position:0% +um this passes that version of it +and as long as we have some other + + align:start position:0% +and as long as we have some other + + + align:start position:0% +and as long as we have some other +condition that says Don't Change vowels + + align:start position:0% +condition that says Don't Change vowels + + + align:start position:0% +condition that says Don't Change vowels +just for the fun of it don't change ooh + + align:start position:0% +just for the fun of it don't change ooh + + + align:start position:0% +just for the fun of it don't change ooh +because you you want to uh which we + + align:start position:0% +because you you want to uh which we + + + align:start position:0% +because you you want to uh which we +surely need right if you give lerdal uh + + align:start position:0% +surely need right if you give lerdal uh + + + align:start position:0% +surely need right if you give lerdal uh +a word that has an ooh in it that's not + + align:start position:0% +a word that has an ooh in it that's not + + + align:start position:0% +a word that has an ooh in it that's not +at the end uh it's not going to change + + align:start position:0% +at the end uh it's not going to change + + + align:start position:0% +at the end uh it's not going to change +um then yes uh then this would win + + align:start position:0% +um then yes uh then this would win + + + align:start position:0% +um then yes uh then this would win +that's right that is indeed one of the + + align:start position:0% +that's right that is indeed one of the + + + align:start position:0% +that's right that is indeed one of the +kinds of things people do in order to + + align:start position:0% +kinds of things people do in order to + + + align:start position:0% +kinds of things people do in order to +handle this kind of problem they make + + align:start position:0% +handle this kind of problem they make + + + align:start position:0% +handle this kind of problem they make +these conditions + + align:start position:0% +these conditions + + + align:start position:0% +these conditions +more complicated yeah because now the + + align:start position:0% +more complicated yeah because now the + + + align:start position:0% +more complicated yeah because now the +conditions the conditions we've had so + + align:start position:0% +conditions the conditions we've had so + + + align:start position:0% +conditions the conditions we've had so +far are all about the form that gets + + align:start position:0% +far are all about the form that gets + + + align:start position:0% +far are all about the form that gets +pronounced they say things like the form + + align:start position:0% +pronounced they say things like the form + + + align:start position:0% +pronounced they say things like the form +that gets pronounced had better not end + + align:start position:0% +that gets pronounced had better not end + + + align:start position:0% +that gets pronounced had better not end +in a k or the form that gets pronounced + + align:start position:0% +in a k or the form that gets pronounced + + + align:start position:0% +in a k or the form that gets pronounced +it better not end in a voiced obstrand + + align:start position:0% +it better not end in a voiced obstrand + + + align:start position:0% +it better not end in a voiced obstrand +if we're doing polish sure you know uh + + align:start position:0% +if we're doing polish sure you know uh + + + align:start position:0% +if we're doing polish sure you know uh +better not have two stridents at the end + + align:start position:0% +better not have two stridents at the end + + + align:start position:0% +better not have two stridents at the end +of the word in a language like English + + align:start position:0% +of the word in a language like English + + + align:start position:0% +of the word in a language like English +this is a more complicated constraint it + + align:start position:0% +this is a more complicated constraint it + + + align:start position:0% +this is a more complicated constraint it +says it had better not end in this kind + + align:start position:0% +says it had better not end in this kind + + + align:start position:0% +says it had better not end in this kind +of sound if it ended in this kind of + + align:start position:0% +of sound if it ended in this kind of + + + align:start position:0% +of sound if it ended in this kind of +sound if it originally you know before + + align:start position:0% +sound if it originally you know before + + + align:start position:0% +sound if it originally you know before +before we started so being so there's a + + align:start position:0% +before we started so being so there's a + + + align:start position:0% +before we started so being so there's a +a an actual debate going on an + + align:start position:0% +a an actual debate going on an + + + align:start position:0% +a an actual debate going on an +optimality theory about whether we want + + align:start position:0% +optimality theory about whether we want + + + align:start position:0% +optimality theory about whether we want +to allow ourselves that kind of power + + align:start position:0% +to allow ourselves that kind of power + + + align:start position:0% +to allow ourselves that kind of power +allowing constraints to make reference + + align:start position:0% +allowing constraints to make reference + + + align:start position:0% +allowing constraints to make reference +not just to the pronounced version but + + align:start position:0% +not just to the pronounced version but + + + align:start position:0% +not just to the pronounced version but +to an earlier version but you're + + align:start position:0% +to an earlier version but you're + + + align:start position:0% +to an earlier version but you're +absolutely right that's the kind of move + + align:start position:0% +absolutely right that's the kind of move + + + align:start position:0% +absolutely right that's the kind of move +people people make people argue for + + align:start position:0% +people people make people argue for + + + align:start position:0% +people people make people argue for +I'm bringing this up just to show you + + align:start position:0% +I'm bringing this up just to show you + + + align:start position:0% +I'm bringing this up just to show you +there's this tension between these two + + align:start position:0% +there's this tension between these two + + + align:start position:0% +there's this tension between these two +ways of thinking about uh phonology and + + align:start position:0% +ways of thinking about uh phonology and + + + align:start position:0% +ways of thinking about uh phonology and +you've just raised one of the ways one + + align:start position:0% +you've just raised one of the ways one + + + align:start position:0% +you've just raised one of the ways one +of the ways in that indeed is has been + + align:start position:0% +of the ways in that indeed is has been + + + align:start position:0% +of the ways in that indeed is has been +taken in the literature to try to figure + + align:start position:0% +taken in the literature to try to figure + + + align:start position:0% +taken in the literature to try to figure +out uh how to deal with this tension but + + align:start position:0% +out uh how to deal with this tension but + + + align:start position:0% +out uh how to deal with this tension but +if you thought that Linguistics was like + + align:start position:0% +if you thought that Linguistics was like + + + align:start position:0% +if you thought that Linguistics was like +finished like we understood everything + + align:start position:0% +finished like we understood everything + + + align:start position:0% +finished like we understood everything +no yeah so this is one of the kinds of + + align:start position:0% +no yeah so this is one of the kinds of + + + align:start position:0% +no yeah so this is one of the kinds of +things that linguists still fight about + + align:start position:0% +things that linguists still fight about + + + align:start position:0% +things that linguists still fight about +like how to how to deal with these kinds + + align:start position:0% +like how to how to deal with these kinds + + + align:start position:0% +like how to how to deal with these kinds +of tensions yes + + align:start position:0% +of tensions yes + + + align:start position:0% +of tensions yes +I think we can still think + + align:start position:0% + + + + align:start position:0% + +we can you know make it like Assembly + + align:start position:0% +we can you know make it like Assembly + + + align:start position:0% +we can you know make it like Assembly +Language + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% + + + + align:start position:0% + +yeah yeah + + align:start position:0% +yeah yeah + + + align:start position:0% +yeah yeah +so that is another kind of move that + + align:start position:0% +so that is another kind of move that + + + align:start position:0% +so that is another kind of move that +people make sorry this uh slide has gone + + align:start position:0% +people make sorry this uh slide has gone + + + align:start position:0% +people make sorry this uh slide has gone +away + + align:start position:0% + + + + align:start position:0% + +um that isn't another kind of move that + + align:start position:0% +um that isn't another kind of move that + + + align:start position:0% +um that isn't another kind of move that +people make where they say + + align:start position:0% +people make where they say + + + align:start position:0% +people make where they say +um well there are various ways of + + align:start position:0% +um well there are various ways of + + + align:start position:0% +um well there are various ways of +interpreting what you just said uh one + + align:start position:0% +interpreting what you just said uh one + + + align:start position:0% +interpreting what you just said uh one +thing that one move that people made + + align:start position:0% +thing that one move that people made + + + align:start position:0% +thing that one move that people made +especially early on when people were + + align:start position:0% +especially early on when people were + + + align:start position:0% +especially early on when people were +worried about this problem in optimality + + align:start position:0% +worried about this problem in optimality + + + align:start position:0% +worried about this problem in optimality +theory was to say uh we're going to do + + align:start position:0% +theory was to say uh we're going to do + + + align:start position:0% +theory was to say uh we're going to do +something an optimality theory that + + align:start position:0% +something an optimality theory that + + + align:start position:0% +something an optimality theory that +allows us to simulate having rules in + + align:start position:0% +allows us to simulate having rules in + + + align:start position:0% +allows us to simulate having rules in +order so what we'll do is we'll have a + + align:start position:0% +order so what we'll do is we'll have a + + + align:start position:0% +order so what we'll do is we'll have a +word go through the tableaus more than + + align:start position:0% +word go through the tableaus more than + + + align:start position:0% +word go through the tableaus more than +once + + align:start position:0% +once + + + align:start position:0% +once +and the or the conditions can be in + + align:start position:0% +and the or the conditions can be in + + + align:start position:0% +and the or the conditions can be in +different orders in the different + + align:start position:0% +different orders in the different + + + align:start position:0% +different orders in the different +tableaus so we'll have a tableau first + + align:start position:0% +tableaus so we'll have a tableau first + + + align:start position:0% +tableaus so we'll have a tableau first +that says uh you know final K is very + + align:start position:0% +that says uh you know final K is very + + + align:start position:0% +that says uh you know final K is very +bad let's say and it doesn't have + + align:start position:0% +bad let's say and it doesn't have + + + align:start position:0% +bad let's say and it doesn't have +final ooh is bad right and then we'll + + align:start position:0% +final ooh is bad right and then we'll + + + align:start position:0% +final ooh is bad right and then we'll +have another Tableau that maybe doesn't + + align:start position:0% +have another Tableau that maybe doesn't + + + align:start position:0% +have another Tableau that maybe doesn't +have final K is very bad but has final + + align:start position:0% +have final K is very bad but has final + + + align:start position:0% +have final K is very bad but has final +ooh is bad right and that's a way to + + align:start position:0% +ooh is bad right and that's a way to + + + align:start position:0% +ooh is bad right and that's a way to +simulate ordered rules basically is to + + align:start position:0% +simulate ordered rules basically is to + + + align:start position:0% +simulate ordered rules basically is to +say we go through tableaus multiple + + align:start position:0% +say we go through tableaus multiple + + + align:start position:0% +say we go through tableaus multiple +times and the the tableaus look + + align:start position:0% +times and the the tableaus look + + + align:start position:0% +times and the the tableaus look +different from each other they have + + align:start position:0% +different from each other they have + + + align:start position:0% +different from each other they have +different conditions in them or they + + align:start position:0% +different conditions in them or they + + + align:start position:0% +different conditions in them or they +have the conditions in different orders + + align:start position:0% +have the conditions in different orders + + + align:start position:0% +have the conditions in different orders +that's one way one way to talk about it + + align:start position:0% +that's one way one way to talk about it + + + align:start position:0% +that's one way one way to talk about it +you might have had a more clever idea + + align:start position:0% +you might have had a more clever idea + + + align:start position:0% +you might have had a more clever idea +though which was the tableaus I was + + align:start position:0% +though which was the tableaus I was + + + align:start position:0% +though which was the tableaus I was +talking as though these rules are uh + + align:start position:0% +talking as though these rules are uh + + + align:start position:0% +talking as though these rules are uh +ranked with respect to each other you + + align:start position:0% +ranked with respect to each other you + + + align:start position:0% +ranked with respect to each other you +know which ones are more important than + + align:start position:0% +know which ones are more important than + + + align:start position:0% +know which ones are more important than +which other ones but optimality Theory + + align:start position:0% +which other ones but optimality Theory + + + align:start position:0% +which other ones but optimality Theory +people are generally talking novice + + align:start position:0% +people are generally talking novice + + + align:start position:0% +people are generally talking novice +though those happen one at a time uh + + align:start position:0% +though those happen one at a time uh + + + align:start position:0% +though those happen one at a time uh +it's just you're considering all these + + align:start position:0% +it's just you're considering all these + + + align:start position:0% +it's just you're considering all these +possibilities and you decide which one + + align:start position:0% +possibilities and you decide which one + + + align:start position:0% +possibilities and you decide which one +is best by all of these conditions you + + align:start position:0% +is best by all of these conditions you + + + align:start position:0% +is best by all of these conditions you +sound like you're thinking about + + align:start position:0% +sound like you're thinking about + + + align:start position:0% +sound like you're thinking about +something different where you would say + + align:start position:0% +something different where you would say + + + align:start position:0% +something different where you would say +you'd go back to the simple one + + align:start position:0% +you'd go back to the simple one + + + align:start position:0% +you'd go back to the simple one +and you'd say we start with LA look + + align:start position:0% + + + + align:start position:0% + +um and uh what we want is something that + + align:start position:0% +um and uh what we want is something that + + + align:start position:0% +um and uh what we want is something that +says something like well I should have + + align:start position:0% +says something like well I should have + + + align:start position:0% +says something like well I should have +put star final ooh first + + align:start position:0% +put star final ooh first + + + align:start position:0% +put star final ooh first +maybe I'll just reverse these + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% +um + + + align:start position:0% +um +uh we have all of our all of our + + align:start position:0% +uh we have all of our all of our + + + align:start position:0% +uh we have all of our all of our +candidates here and we first consider + + align:start position:0% +candidates here and we first consider + + + align:start position:0% +candidates here and we first consider +star final ooh uh-oh but if we consider + + align:start position:0% +star final ooh uh-oh but if we consider + + + align:start position:0% +star final ooh uh-oh but if we consider +a star final ooh star final ooh we'll + + align:start position:0% +a star final ooh star final ooh we'll + + + align:start position:0% +a star final ooh star final ooh we'll +look at nalu and it will it will knock + + align:start position:0% +look at nalu and it will it will knock + + + align:start position:0% +look at nalu and it will it will knock +it out right right so that that will be + + align:start position:0% +it out right right so that that will be + + + align:start position:0% +it out right right so that that will be +bad right there and and we won't ever + + align:start position:0% +bad right there and and we won't ever + + + align:start position:0% +bad right there and and we won't ever +get it back if we do that so what we + + align:start position:0% +get it back if we do that so what we + + + align:start position:0% +get it back if we do that so what we +want is something more like using the + + align:start position:0% +want is something more like using the + + + align:start position:0% +want is something more like using the +teplo to to do something like ordered + + align:start position:0% +teplo to to do something like ordered + + + align:start position:0% +teplo to to do something like ordered +rules you know something that says + + align:start position:0% +rules you know something that says + + + align:start position:0% +rules you know something that says +um we look at this first thing and we we + + align:start position:0% +um we look at this first thing and we we + + + align:start position:0% +um we look at this first thing and we we +are now basically doing rules in an + + align:start position:0% +are now basically doing rules in an + + + align:start position:0% +are now basically doing rules in an +order uh we look at this first thing and + + align:start position:0% +order uh we look at this first thing and + + + align:start position:0% +order uh we look at this first thing and +we ask ourselves what's not look well uh + + align:start position:0% +we ask ourselves what's not look well uh + + + align:start position:0% +we ask ourselves what's not look well uh +it doesn't it doesn't violate this first + + align:start position:0% +it doesn't it doesn't violate this first + + + align:start position:0% +it doesn't it doesn't violate this first +rule and so we'll keep it + + align:start position:0% +rule and so we'll keep it + + + align:start position:0% +rule and so we'll keep it +and then we'll consider the next rule it + + align:start position:0% +and then we'll consider the next rule it + + + align:start position:0% +and then we'll consider the next rule it +does violate that rule and so we'll + + align:start position:0% +does violate that rule and so we'll + + + align:start position:0% +does violate that rule and so we'll +change it we'll make a minimal change to + + align:start position:0% +change it we'll make a minimal change to + + + align:start position:0% +change it we'll make a minimal change to +it this is a way of converting tableaus + + align:start position:0% +it this is a way of converting tableaus + + + align:start position:0% +it this is a way of converting tableaus +into ordered rules I think that's what + + align:start position:0% +into ordered rules I think that's what + + + align:start position:0% +into ordered rules I think that's what +we're now doing + + align:start position:0% +we're now doing + + + align:start position:0% +we're now doing +um and uh it could be yeah after all + + align:start position:0% +um and uh it could be yeah after all + + + align:start position:0% +um and uh it could be yeah after all +things things to think about open + + align:start position:0% +things things to think about open + + + align:start position:0% +things things to think about open +research questions + + align:start position:0% +research questions + + + align:start position:0% +research questions +cool + + align:start position:0% +cool + + + align:start position:0% +cool +okay so the goal here was to get all of + + align:start position:0% +okay so the goal here was to get all of + + + align:start position:0% +okay so the goal here was to get all of +you to try to do better than Linguistics + + align:start position:0% +you to try to do better than Linguistics + + + align:start position:0% +you to try to do better than Linguistics +is so far done so right now we have + + align:start position:0% +is so far done so right now we have + + + align:start position:0% +is so far done so right now we have +these two ways of thinking about + + align:start position:0% +these two ways of thinking about + + + align:start position:0% +these two ways of thinking about +phonology and there are in some kind of + + align:start position:0% +phonology and there are in some kind of + + + align:start position:0% +phonology and there are in some kind of +conflict with each other and there's + + align:start position:0% +conflict with each other and there's + + + align:start position:0% +conflict with each other and there's +active work on trying to figure out how + + align:start position:0% +active work on trying to figure out how + + + align:start position:0% +active work on trying to figure out how +to get them to mesh + + align:start position:0% +to get them to mesh + + + align:start position:0% +to get them to mesh +okay + + align:start position:0% + + + + align:start position:0% + +um okay + + align:start position:0% +um okay + + + align:start position:0% +um okay +cool + + align:start position:0% +cool + + + align:start position:0% +cool +where are we + + align:start position:0% +where are we + + + align:start position:0% +where are we +here we are Center and some obstruents + + align:start position:0% +here we are Center and some obstruents + + + align:start position:0% +here we are Center and some obstruents +we did that we did that + + align:start position:0% +we did that we did that + + + align:start position:0% +we did that we did that +okay so um let me introduce you we're + + align:start position:0% +okay so um let me introduce you we're + + + align:start position:0% +okay so um let me introduce you we're +running yeah yeah let me introduce you + + align:start position:0% +running yeah yeah let me introduce you + + + align:start position:0% +running yeah yeah let me introduce you +to another + + align:start position:0% +to another + + + align:start position:0% +to another +um + + align:start position:0% +um + + + align:start position:0% +um +uh another class of sounds uh again the + + align:start position:0% +uh another class of sounds uh again the + + + align:start position:0% +uh another class of sounds uh again the +the point is to show you uh ways in + + align:start position:0% +the point is to show you uh ways in + + + align:start position:0% +the point is to show you uh ways in +which it's useful to categorize sounds + + align:start position:0% +which it's useful to categorize sounds + + + align:start position:0% +which it's useful to categorize sounds +and the way to try to convince you of + + align:start position:0% +and the way to try to convince you of + + + align:start position:0% +and the way to try to convince you of +that is to show you phenomena that care + + align:start position:0% +that is to show you phenomena that care + + + align:start position:0% +that is to show you phenomena that care +about certain classes of sounds and not + + align:start position:0% +about certain classes of sounds and not + + + align:start position:0% +about certain classes of sounds and not +others uh here are a bunch of Arabic + + align:start position:0% +others uh here are a bunch of Arabic + + + align:start position:0% +others uh here are a bunch of Arabic +nouns together with their definite + + align:start position:0% +nouns together with their definite + + + align:start position:0% +nouns together with their definite +article which you can see is of uh + + align:start position:0% +article which you can see is of uh + + + align:start position:0% +article which you can see is of uh +English is borrowed a bunch of Arabic + + align:start position:0% +English is borrowed a bunch of Arabic + + + align:start position:0% +English is borrowed a bunch of Arabic +words uh that have kept this all so we + + align:start position:0% +words uh that have kept this all so we + + + align:start position:0% +words uh that have kept this all so we +have words like algebra for example or + + align:start position:0% +have words like algebra for example or + + + align:start position:0% +have words like algebra for example or +algorithm where the owl at the end is + + align:start position:0% +algorithm where the owl at the end is + + + align:start position:0% +algorithm where the owl at the end is +this word for the yeah + + align:start position:0% +this word for the yeah + + + align:start position:0% +this word for the yeah +uh so here are some Arabic nouns with + + align:start position:0% +uh so here are some Arabic nouns with + + + align:start position:0% +uh so here are some Arabic nouns with +the word for the in front of them + + align:start position:0% +the word for the in front of them + + + align:start position:0% +the word for the in front of them +but there's this other class of nouns + + align:start position:0% +but there's this other class of nouns + + + align:start position:0% +but there's this other class of nouns +where the word for the changes it's no + + align:start position:0% +where the word for the changes it's no + + + align:start position:0% +where the word for the changes it's no +longer Al + + align:start position:0% +longer Al + + + align:start position:0% +longer Al +um what it gets it still starts with ah + + align:start position:0% +um what it gets it still starts with ah + + + align:start position:0% +um what it gets it still starts with ah +that the consonant in it becomes a copy + + align:start position:0% +that the consonant in it becomes a copy + + + align:start position:0% +that the consonant in it becomes a copy +of the consonant that's after it + + align:start position:0% +of the consonant that's after it + + + align:start position:0% +of the consonant that's after it +so the word for sun which is Shams uh + + align:start position:0% +so the word for sun which is Shams uh + + + align:start position:0% +so the word for sun which is Shams uh +the sun is Ash it's not al-shams + + align:start position:0% +the sun is Ash it's not al-shams + + + align:start position:0% +the sun is Ash it's not al-shams +here I am pretending to speak Arabic is + + align:start position:0% +here I am pretending to speak Arabic is + + + align:start position:0% +here I am pretending to speak Arabic is +there anyone here who actually speaks + + align:start position:0% +there anyone here who actually speaks + + + align:start position:0% +there anyone here who actually speaks +Arabic + + align:start position:0% +Arabic + + + align:start position:0% +Arabic +okay cool I'll just keep pretending + + align:start position:0% +okay cool I'll just keep pretending + + + align:start position:0% +okay cool I'll just keep pretending +um + + align:start position:0% +um + + + align:start position:0% +um +okay uh this is a classic observation + + align:start position:0% +okay uh this is a classic observation + + + align:start position:0% +okay uh this is a classic observation +Arabic linguists noticed this about + + align:start position:0% +Arabic linguists noticed this about + + + align:start position:0% +Arabic linguists noticed this about +their language uh um they name uh and + + align:start position:0% +their language uh um they name uh and + + + align:start position:0% +their language uh um they name uh and +and noticed the relevant condition is + + align:start position:0% +and noticed the relevant condition is + + + align:start position:0% +and noticed the relevant condition is +that there are certain kinds of sounds + + align:start position:0% +that there are certain kinds of sounds + + + align:start position:0% +that there are certain kinds of sounds +that get the phenomenon on the right + + align:start position:0% +that get the phenomenon on the right + + + align:start position:0% +that get the phenomenon on the right +where the definite article ends in a + + align:start position:0% +where the definite article ends in a + + + align:start position:0% +where the definite article ends in a +copy of the first consonant of the uh + + align:start position:0% +copy of the first consonant of the uh + + + align:start position:0% +copy of the first consonant of the uh +the following noun and other consonants + + align:start position:0% +the following noun and other consonants + + + align:start position:0% +the following noun and other consonants +that don't do that they're they're + + align:start position:0% +that don't do that they're they're + + + align:start position:0% +that don't do that they're they're +called Moon letters and Sun letters + + align:start position:0% +called Moon letters and Sun letters + + + align:start position:0% +called Moon letters and Sun letters +um in the in the Arabic tradition + + align:start position:0% +um in the in the Arabic tradition + + + align:start position:0% +um in the in the Arabic tradition +because well moon is one of the words in + + align:start position:0% +because well moon is one of the words in + + + align:start position:0% +because well moon is one of the words in +the column on the left and sun is one of + + align:start position:0% +the column on the left and sun is one of + + + align:start position:0% +the column on the left and sun is one of +the words in the column on the right + + align:start position:0% +the words in the column on the right + + + align:start position:0% +the words in the column on the right +mnemonic these classes of sounds so the + + align:start position:0% +mnemonic these classes of sounds so the + + + align:start position:0% +mnemonic these classes of sounds so the +moon letters are letters like and K and + + align:start position:0% +moon letters are letters like and K and + + + align:start position:0% +moon letters are letters like and K and +H and Global stop + + align:start position:0% +H and Global stop + + + align:start position:0% +H and Global stop +and the sun letters are sounds like + + align:start position:0% + + + + align:start position:0% + +the moon letters + + align:start position:0% +the moon letters + + + align:start position:0% +the moon letters +no the sun letters yes the sun letters + + align:start position:0% +no the sun letters yes the sun letters + + + align:start position:0% +no the sun letters yes the sun letters +uh are the ones that I've got in the box + + align:start position:0% +uh are the ones that I've got in the box + + + align:start position:0% +uh are the ones that I've got in the box +there they are what are called coronals + + align:start position:0% +there they are what are called coronals + + + align:start position:0% +there they are what are called coronals +so coronals are the interdentals and the + + align:start position:0% +so coronals are the interdentals and the + + + align:start position:0% +so coronals are the interdentals and the +alveolars and the post alveolars if you + + align:start position:0% +alveolars and the post alveolars if you + + + align:start position:0% +alveolars and the post alveolars if you +think about them so you know feel free + + align:start position:0% +think about them so you know feel free + + + align:start position:0% +think about them so you know feel free +to sit there making those noises to + + align:start position:0% +to sit there making those noises to + + + align:start position:0% +to sit there making those noises to +yourself if you want to + + align:start position:0% +yourself if you want to + + + align:start position:0% +yourself if you want to +um what what all of them do is make a + + align:start position:0% +um what what all of them do is make a + + + align:start position:0% +um what what all of them do is make a +consonant sound that's articulated with + + align:start position:0% +consonant sound that's articulated with + + + align:start position:0% +consonant sound that's articulated with +the tip or the blade of your tongue sort + + align:start position:0% +the tip or the blade of your tongue sort + + + align:start position:0% +the tip or the blade of your tongue sort +of the front of your tongue is touching + + align:start position:0% +of the front of your tongue is touching + + + align:start position:0% +of the front of your tongue is touching +some part of the top of your mouth or or + + align:start position:0% +some part of the top of your mouth or or + + + align:start position:0% +some part of the top of your mouth or or +other places so the interdentals your + + align:start position:0% +other places so the interdentals your + + + align:start position:0% +other places so the interdentals your +tongue is sticking out between your + + align:start position:0% +tongue is sticking out between your + + + align:start position:0% +tongue is sticking out between your +teeth are the alveolars or the post + + align:start position:0% +teeth are the alveolars or the post + + + align:start position:0% +teeth are the alveolars or the post +alveolars the tip of your tongue or the + + align:start position:0% +alveolars the tip of your tongue or the + + + align:start position:0% +alveolars the tip of your tongue or the +blade of your tongue is coming into + + align:start position:0% +blade of your tongue is coming into + + + align:start position:0% +blade of your tongue is coming into +contact almost with the top of your + + align:start position:0% +contact almost with the top of your + + + align:start position:0% +contact almost with the top of your +mouth yeah + + align:start position:0% +mouth yeah + + + align:start position:0% +mouth yeah +as opposed to say bilabials where your + + align:start position:0% +as opposed to say bilabials where your + + + align:start position:0% +as opposed to say bilabials where your +tongue can do whatever the heck it feels + + align:start position:0% +tongue can do whatever the heck it feels + + + align:start position:0% +tongue can do whatever the heck it feels +like or veelers which involve your + + align:start position:0% +like or veelers which involve your + + + align:start position:0% +like or veelers which involve your +tongue or uvulus which involve your + + align:start position:0% +tongue or uvulus which involve your + + + align:start position:0% +tongue or uvulus which involve your +tongue but it's the back of your tongue + + align:start position:0% +tongue but it's the back of your tongue + + + align:start position:0% +tongue but it's the back of your tongue +as opposed to the front of your tongue + + align:start position:0% +as opposed to the front of your tongue + + + align:start position:0% +as opposed to the front of your tongue +which is what you're using for things + + align:start position:0% +which is what you're using for things + + + align:start position:0% +which is what you're using for things +like and + + align:start position:0% + + + + align:start position:0% + +is that clear the distinction clear and + + align:start position:0% +is that clear the distinction clear and + + + align:start position:0% +is that clear the distinction clear and +uh Arabic gives us a nice + + align:start position:0% +uh Arabic gives us a nice + + + align:start position:0% +uh Arabic gives us a nice +um uh sort of illustration of this the + + align:start position:0% +um uh sort of illustration of this the + + + align:start position:0% +um uh sort of illustration of this the +coronal sounds are the ones that are the + + align:start position:0% +coronal sounds are the ones that are the + + + align:start position:0% +coronal sounds are the ones that are the +the sun letters they're the ones where + + align:start position:0% +the sun letters they're the ones where + + + align:start position:0% +the sun letters they're the ones where +you uh the the last consonant of the + + align:start position:0% +you uh the the last consonant of the + + + align:start position:0% +you uh the the last consonant of the +definite article just becomes a copy of + + align:start position:0% +definite article just becomes a copy of + + + align:start position:0% +definite article just becomes a copy of +the following consonant notice that the + + align:start position:0% +the following consonant notice that the + + + align:start position:0% +the following consonant notice that the +last consonant of the indefinite article + + align:start position:0% +last consonant of the indefinite article + + + align:start position:0% +last consonant of the indefinite article +underlyingly is L which is itself + + align:start position:0% +underlyingly is L which is itself + + + align:start position:0% +underlyingly is L which is itself +coronal so uh it's like the end of the + + align:start position:0% +coronal so uh it's like the end of the + + + align:start position:0% +coronal so uh it's like the end of the +definite article is going to be coronal + + align:start position:0% +definite article is going to be coronal + + + align:start position:0% +definite article is going to be coronal +uh if nothing else happens it's going to + + align:start position:0% +uh if nothing else happens it's going to + + + align:start position:0% +uh if nothing else happens it's going to +be L but if there's a cardinal right + + align:start position:0% +be L but if there's a cardinal right + + + align:start position:0% +be L but if there's a cardinal right +after it it just becomes a copy of the + + align:start position:0% +after it it just becomes a copy of the + + + align:start position:0% +after it it just becomes a copy of the +following chordal does that make sense + + align:start position:0% +following chordal does that make sense + + + align:start position:0% +following chordal does that make sense +that's what's going on in all of these + + align:start position:0% +that's what's going on in all of these + + + align:start position:0% +that's what's going on in all of these +examples so with moon and Mare and book + + align:start position:0% +examples so with moon and Mare and book + + + align:start position:0% +examples so with moon and Mare and book +and more and father the L of the + + align:start position:0% +and more and father the L of the + + + align:start position:0% +and more and father the L of the +definite article can't become a copy of + + align:start position:0% +definite article can't become a copy of + + + align:start position:0% +definite article can't become a copy of +the following consonant and remain + + align:start position:0% +the following consonant and remain + + + align:start position:0% +the following consonant and remain +coronal yeah whereas in the sun letters + + align:start position:0% +coronal yeah whereas in the sun letters + + + align:start position:0% +coronal yeah whereas in the sun letters +the ones on the right by copying the + + align:start position:0% +the ones on the right by copying the + + + align:start position:0% +the ones on the right by copying the +following consonant the the L of the + + align:start position:0% +following consonant the the L of the + + + align:start position:0% +following consonant the the L of the +definite article is still a coronal + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +somebody had a great idea about that + + align:start position:0% + + + + align:start position:0% + +uh so that's what's going on in these uh + + align:start position:0% +uh so that's what's going on in these uh + + + align:start position:0% +uh so that's what's going on in these uh +in these Arabic examples + + align:start position:0% + + + + align:start position:0% + +um okay a rule that we could have for + + align:start position:0% +um okay a rule that we could have for + + + align:start position:0% +um okay a rule that we could have for +the Arabic definite article yes I just + + align:start position:0% +the Arabic definite article yes I just + + + align:start position:0% +the Arabic definite article yes I just +said this thank you L is also Cardinal + + align:start position:0% +said this thank you L is also Cardinal + + + align:start position:0% +said this thank you L is also Cardinal +uh a rule we could have for the Arabic + + align:start position:0% +uh a rule we could have for the Arabic + + + align:start position:0% +uh a rule we could have for the Arabic +definite article would say you know in + + align:start position:0% +definite article would say you know in + + + align:start position:0% +definite article would say you know in +the definite article and L becomes a + + align:start position:0% +the definite article and L becomes a + + + align:start position:0% +the definite article and L becomes a +copy of a following coronal consonant so + + align:start position:0% +copy of a following coronal consonant so + + + align:start position:0% +copy of a following coronal consonant so +you know we have sort of a variable + + align:start position:0% +you know we have sort of a variable + + + align:start position:0% +you know we have sort of a variable +consonants uh subscript I which says + + align:start position:0% +consonants uh subscript I which says + + + align:start position:0% +consonants uh subscript I which says +whatever the con following consonant is + + align:start position:0% +whatever the con following consonant is + + + align:start position:0% +whatever the con following consonant is +if it's coronal uh the L will also get + + align:start position:0% +if it's coronal uh the L will also get + + + align:start position:0% +if it's coronal uh the L will also get +the value consonant sub I but it'll + + align:start position:0% +the value consonant sub I but it'll + + + align:start position:0% +the value consonant sub I but it'll +it'll it'll have the same form as the + + align:start position:0% +it'll it'll have the same form as the + + + align:start position:0% +it'll it'll have the same form as the +following consonant yeah + + align:start position:0% + + + + align:start position:0% + +you know + + align:start position:0% +you know + + + align:start position:0% +you know +or like uh which means home yeah + + align:start position:0% +or like uh which means home yeah + + + align:start position:0% +or like uh which means home yeah +and uh Arabic actually has + + align:start position:0% +and uh Arabic actually has + + + align:start position:0% +and uh Arabic actually has +like which like duplicates uh one letter + + align:start position:0% +like which like duplicates uh one letter + + + align:start position:0% +like which like duplicates uh one letter +yeah so + + align:start position:0% +yeah so + + + align:start position:0% +yeah so +so I think is that when you can + + align:start position:0% +so I think is that when you can + + + align:start position:0% +so I think is that when you can +duplicate the letter you just duplicate + + align:start position:0% +duplicate the letter you just duplicate + + + align:start position:0% +duplicate the letter you just duplicate +it + + align:start position:0% +it + + + align:start position:0% +it +yeah yeah + + align:start position:0% +yeah yeah + + + align:start position:0% +yeah yeah +there's like the the moon yeah you can + + align:start position:0% +there's like the the moon yeah you can + + + align:start position:0% +there's like the the moon yeah you can +do that so yeah so but there are I see + + align:start position:0% +do that so yeah so but there are I see + + + align:start position:0% +do that so yeah so but there are I see +what you mean but look there there are + + align:start position:0% +what you mean but look there there are + + + align:start position:0% +what you mean but look there there are +uh consonants like uh p and t and K + + align:start position:0% +uh consonants like uh p and t and K + + + align:start position:0% +uh consonants like uh p and t and K +which are all stops but T is coronal and + + align:start position:0% +which are all stops but T is coronal and + + + align:start position:0% +which are all stops but T is coronal and +P and K are not right and so all of + + align:start position:0% +P and K are not right and so all of + + + align:start position:0% +P and K are not right and so all of +those are equally hard to maintain for a + + align:start position:0% +those are equally hard to maintain for a + + + align:start position:0% +those are equally hard to maintain for a +long time I think or similarly I think + + align:start position:0% +long time I think or similarly I think + + + align:start position:0% +long time I think or similarly I think +what we're hoping you can stop me if + + align:start position:0% +what we're hoping you can stop me if + + + align:start position:0% +what we're hoping you can stop me if +this is not true is that if there are + + align:start position:0% +this is not true is that if there are + + + align:start position:0% +this is not true is that if there are +Arabic words that start with M uh those + + align:start position:0% +Arabic words that start with M uh those + + + align:start position:0% +Arabic words that start with M uh those +you'll get Al before that before in M + + align:start position:0% +you'll get Al before that before in M + + + align:start position:0% +you'll get Al before that before in M +yeah but for Arabic words that start + + align:start position:0% +yeah but for Arabic words that start + + + align:start position:0% +yeah but for Arabic words that start +with n you get a copy of the N yeah and + + align:start position:0% +with n you get a copy of the N yeah and + + + align:start position:0% +with n you get a copy of the N yeah and +again those are all sort of equally easy + + align:start position:0% +again those are all sort of equally easy + + + align:start position:0% +again those are all sort of equally easy +to hold on for a long time so that's a + + align:start position:0% +to hold on for a long time so that's a + + + align:start position:0% +to hold on for a long time so that's a +good this is a good example of science + + align:start position:0% +good this is a good example of science + + + align:start position:0% +good this is a good example of science +you know you had a good hypothesis and + + align:start position:0% +you know you had a good hypothesis and + + + align:start position:0% +you know you had a good hypothesis and +now we're finding data yeah and you + + align:start position:0% +now we're finding data yeah and you + + + align:start position:0% +now we're finding data yeah and you +speak I should have called on you to do + + align:start position:0% +speak I should have called on you to do + + + align:start position:0% +speak I should have called on you to do +to to say these Arabic words yeah Joseph + + align:start position:0% + + + + align:start position:0% + +algebra + + align:start position:0% +algebra + + + align:start position:0% +algebra +at least the English pronunciation + + align:start position:0% +at least the English pronunciation + + + align:start position:0% +at least the English pronunciation +starts really oh yeah but in Arabic I + + align:start position:0% +starts really oh yeah but in Arabic I + + + align:start position:0% +starts really oh yeah but in Arabic I +think it doesn't so uh so the baby maybe + + align:start position:0% +think it doesn't so uh so the baby maybe + + + align:start position:0% +think it doesn't so uh so the baby maybe +you know do you know what algebra is in + + align:start position:0% +you know do you know what algebra is in + + + align:start position:0% +you know do you know what algebra is in +in Arabic + + align:start position:0% + + + + align:start position:0% + +oh okay + + align:start position:0% +oh okay + + + align:start position:0% +oh okay +so I got it backwards yeah so we we uh + + align:start position:0% +so I got it backwards yeah so we we uh + + + align:start position:0% +so I got it backwards yeah so we we uh +we kept the L we didn't do the change so + + align:start position:0% +we kept the L we didn't do the change so + + + align:start position:0% +we kept the L we didn't do the change so +it starts it starts with a J uh starts + + align:start position:0% +it starts it starts with a J uh starts + + + align:start position:0% +it starts it starts with a J uh starts +with a chord and I'll but it didn't do + + align:start position:0% +with a chord and I'll but it didn't do + + + align:start position:0% +with a chord and I'll but it didn't do +the change I wonder whether we borrowed + + align:start position:0% +the change I wonder whether we borrowed + + + align:start position:0% +the change I wonder whether we borrowed +it before Arabic did this sound change + + align:start position:0% +it before Arabic did this sound change + + + align:start position:0% +it before Arabic did this sound change +uh I have no idea I don't know enough + + align:start position:0% +uh I have no idea I don't know enough + + + align:start position:0% +uh I have no idea I don't know enough +about the history of Arabic + + align:start position:0% +about the history of Arabic + + + align:start position:0% +about the history of Arabic +cool + + align:start position:0% +cool + + + align:start position:0% +cool +yep + + align:start position:0% + + + + align:start position:0% + +all right + + align:start position:0% +all right + + + align:start position:0% +all right +um + + align:start position:0% +um + + + align:start position:0% +um +so this is one kind of rule uh it's a + + align:start position:0% +so this is one kind of rule uh it's a + + + align:start position:0% +so this is one kind of rule uh it's a +very common kind of rule where one sound + + align:start position:0% +very common kind of rule where one sound + + + align:start position:0% +very common kind of rule where one sound +becomes more like another sound it's + + align:start position:0% +becomes more like another sound it's + + + align:start position:0% +becomes more like another sound it's +called the simulation + + align:start position:0% +called the simulation + + + align:start position:0% +called the simulation +um and uh this particular case it's + + align:start position:0% +um and uh this particular case it's + + + align:start position:0% +um and uh this particular case it's +what's sometimes called total + + align:start position:0% +what's sometimes called total + + + align:start position:0% +what's sometimes called total +assimilation where uh one sound just + + align:start position:0% +assimilation where uh one sound just + + + align:start position:0% +assimilation where uh one sound just +becomes a complete copy of another sound + + align:start position:0% +becomes a complete copy of another sound + + + align:start position:0% +becomes a complete copy of another sound +we'll see other cases where one sound + + align:start position:0% +we'll see other cases where one sound + + + align:start position:0% +we'll see other cases where one sound +just kind of changes in ways that + + align:start position:0% +just kind of changes in ways that + + + align:start position:0% +just kind of changes in ways that +resemble a nearby sound + + align:start position:0% +resemble a nearby sound + + + align:start position:0% +resemble a nearby sound +um uh why do you do assimilation + + align:start position:0% +um uh why do you do assimilation + + + align:start position:0% +um uh why do you do assimilation +languages do assimilation all the time + + align:start position:0% +languages do assimilation all the time + + + align:start position:0% +languages do assimilation all the time +and you sort of not hard to have + + align:start position:0% +and you sort of not hard to have + + + align:start position:0% +and you sort of not hard to have +pre-theoretical Notions about why right + + align:start position:0% +pre-theoretical Notions about why right + + + align:start position:0% +pre-theoretical Notions about why right +that you're saving wear and tear on your + + align:start position:0% +that you're saving wear and tear on your + + + align:start position:0% +that you're saving wear and tear on your +articulators uh so you know making it so + + align:start position:0% +articulators uh so you know making it so + + + align:start position:0% +articulators uh so you know making it so +that your articulators your tongue your + + align:start position:0% +that your articulators your tongue your + + + align:start position:0% +that your articulators your tongue your +lips you know uh uh velum don't have to + + align:start position:0% +lips you know uh uh velum don't have to + + + align:start position:0% +lips you know uh uh velum don't have to +do as much moving around uh things uh + + align:start position:0% +do as much moving around uh things uh + + + align:start position:0% +do as much moving around uh things uh +don't move as far or don't move at all + + align:start position:0% +don't move as far or don't move at all + + + align:start position:0% +don't move as far or don't move at all +it probably also makes perception easier + + align:start position:0% +it probably also makes perception easier + + + align:start position:0% +it probably also makes perception easier +in the sense that + + align:start position:0% +in the sense that + + + align:start position:0% +in the sense that +um if you're speaking Arabic and you uh + + align:start position:0% +um if you're speaking Arabic and you uh + + + align:start position:0% +um if you're speaking Arabic and you uh +instead of an L so for uh let's take the + + align:start position:0% +instead of an L so for uh let's take the + + + align:start position:0% +instead of an L so for uh let's take the +Sun + + align:start position:0% + + + + align:start position:0% + +um uh you know if you know that the word + + align:start position:0% +um uh you know if you know that the word + + + align:start position:0% +um uh you know if you know that the word +for sun is shem's uh and you've got this + + align:start position:0% +for sun is shem's uh and you've got this + + + align:start position:0% +for sun is shem's uh and you've got this +thing before it + + align:start position:0% +thing before it + + + align:start position:0% +thing before it +um basically it's as though you only + + align:start position:0% +um basically it's as though you only + + + align:start position:0% +um basically it's as though you only +need to give your hearer enough + + align:start position:0% +need to give your hearer enough + + + align:start position:0% +need to give your hearer enough +information to help them to know that + + align:start position:0% +information to help them to know that + + + align:start position:0% +information to help them to know that +they're hearing a definite article + + align:start position:0% +they're hearing a definite article + + + align:start position:0% +they're hearing a definite article +before the word for sun + + align:start position:0% +before the word for sun + + + align:start position:0% +before the word for sun +um and Arabic has decided uh it's enough + + align:start position:0% +um and Arabic has decided uh it's enough + + + align:start position:0% +um and Arabic has decided uh it's enough +if you hear the glottal stop and the + + align:start position:0% +if you hear the glottal stop and the + + + align:start position:0% +if you hear the glottal stop and the +vowel and then a coronal yeah + + align:start position:0% +vowel and then a coronal yeah + + + align:start position:0% +vowel and then a coronal yeah +underlyingly that Cardinal maybe is an L + + align:start position:0% +underlyingly that Cardinal maybe is an L + + + align:start position:0% +underlyingly that Cardinal maybe is an L +but as long as we keep it coronal we've + + align:start position:0% +but as long as we keep it coronal we've + + + align:start position:0% +but as long as we keep it coronal we've +given the hearer enough uh that they get + + align:start position:0% +given the hearer enough uh that they get + + + align:start position:0% +given the hearer enough uh that they get +to hear it and in fact we give the + + align:start position:0% +to hear it and in fact we give the + + + align:start position:0% +to hear it and in fact we give the +hearer in a sense two shots of hearing + + align:start position:0% +hearer in a sense two shots of hearing + + + align:start position:0% +hearer in a sense two shots of hearing +the beginning of the word for sun you + + align:start position:0% +the beginning of the word for sun you + + + align:start position:0% +the beginning of the word for sun you +know so we'll have we'll we'll and we'll + + align:start position:0% +know so we'll have we'll we'll and we'll + + + align:start position:0% +know so we'll have we'll we'll and we'll +lengthen that sound right so we'll we'll + + align:start position:0% +lengthen that sound right so we'll we'll + + + align:start position:0% +lengthen that sound right so we'll we'll +pronounce it twice + + align:start position:0% +pronounce it twice + + + align:start position:0% +pronounce it twice +um so we're sort of redistributing the + + align:start position:0% +um so we're sort of redistributing the + + + align:start position:0% +um so we're sort of redistributing the +signal in a way uh to the hearer to make + + align:start position:0% +signal in a way uh to the hearer to make + + + align:start position:0% +signal in a way uh to the hearer to make +to make their life arguably easier + + align:start position:0% +to make their life arguably easier + + + align:start position:0% +to make their life arguably easier +giving up some of what makes the + + align:start position:0% +giving up some of what makes the + + + align:start position:0% +giving up some of what makes the +definite article distinctive in order to + + align:start position:0% +definite article distinctive in order to + + + align:start position:0% +definite article distinctive in order to +emphasize some of some the beginning of + + align:start position:0% +emphasize some of some the beginning of + + + align:start position:0% +emphasize some of some the beginning of +the word for sun no + + align:start position:0% +the word for sun no + + + align:start position:0% +the word for sun no +questions about any of this yes + + align:start position:0% + + + + align:start position:0% + +so I I was I was trying to to sort of + + align:start position:0% +so I I was I was trying to to sort of + + + align:start position:0% +so I I was I was trying to to sort of +float the idea that it's partly to make + + align:start position:0% +float the idea that it's partly to make + + + align:start position:0% +float the idea that it's partly to make +the pronunciation easier it's so that uh + + align:start position:0% +the pronunciation easier it's so that uh + + + align:start position:0% +the pronunciation easier it's so that uh +your articulators are not having to move + + align:start position:0% +your articulators are not having to move + + + align:start position:0% +your articulators are not having to move +as fast or as far + + align:start position:0% +as fast or as far + + + align:start position:0% +as fast or as far +um but it might also uh make perception + + align:start position:0% +um but it might also uh make perception + + + align:start position:0% +um but it might also uh make perception +in some ways easier in a case like this + + align:start position:0% +in some ways easier in a case like this + + + align:start position:0% +in some ways easier in a case like this +so uh the idea is we'll give up some of + + align:start position:0% +so uh the idea is we'll give up some of + + + align:start position:0% +so uh the idea is we'll give up some of +the special properties of the definite + + align:start position:0% +the special properties of the definite + + + align:start position:0% +the special properties of the definite +article in favor of emphasizing or + + align:start position:0% +article in favor of emphasizing or + + + align:start position:0% +article in favor of emphasizing or +holding for longer the special + + align:start position:0% +holding for longer the special + + + align:start position:0% +holding for longer the special +properties of the word for sun + + align:start position:0% +properties of the word for sun + + + align:start position:0% +properties of the word for sun +or whatever you know the consonant + + align:start position:0% +or whatever you know the consonant + + + align:start position:0% +or whatever you know the consonant +that's at the beginning of the of the + + align:start position:0% +that's at the beginning of the of the + + + align:start position:0% +that's at the beginning of the of the +following now + + align:start position:0% +following now + + + align:start position:0% +following now +um so we'll emphasize some parts of the + + align:start position:0% +um so we'll emphasize some parts of the + + + align:start position:0% +um so we'll emphasize some parts of the +in some ways least predictable part of + + align:start position:0% +in some ways least predictable part of + + + align:start position:0% +in some ways least predictable part of +this you presumably hear definite + + align:start position:0% +this you presumably hear definite + + + align:start position:0% +this you presumably hear definite +articles all the time it's not so + + align:start position:0% +articles all the time it's not so + + + align:start position:0% +articles all the time it's not so +important that you you know get lots of + + align:start position:0% +important that you you know get lots of + + + align:start position:0% +important that you you know get lots of +Clues to the fact that this is an + + align:start position:0% +Clues to the fact that this is an + + + align:start position:0% +Clues to the fact that this is an +infinite article the nouns are going to + + align:start position:0% +infinite article the nouns are going to + + + align:start position:0% +infinite article the nouns are going to +vary you know here are more different + + align:start position:0% +vary you know here are more different + + + align:start position:0% +vary you know here are more different +kinds of nouns + + align:start position:0% + + + + align:start position:0% + +yep okay cool uh this is probably a good + + align:start position:0% +yep okay cool uh this is probably a good + + + align:start position:0% +yep okay cool uh this is probably a good +place to stop so let's stop here and uh + + align:start position:0% +place to stop so let's stop here and uh + + + align:start position:0% +place to stop so let's stop here and uh +have a good weekend and I'll see you + + align:start position:0% +have a good weekend and I'll see you + + + align:start position:0% +have a good weekend and I'll see you +guys uh see you guys next week \ No newline at end of file diff --git a/-dAgY_AMqGk.txt b/-dAgY_AMqGk.txt new file mode 100644 index 0000000000000000000000000000000000000000..b7d126160fdbc44e3f218276eae22af198e67508 --- /dev/null +++ b/-dAgY_AMqGk.txt @@ -0,0 +1,14739 @@ +align:start position:0% + +the following content is provided by mit + + align:start position:0% +the following content is provided by mit + + + align:start position:0% +the following content is provided by mit +opencourseware under a creative commons + + align:start position:0% +opencourseware under a creative commons + + + align:start position:0% +opencourseware under a creative commons +license + + align:start position:0% +license + + + align:start position:0% +license +additional information about our license + + align:start position:0% +additional information about our license + + + align:start position:0% +additional information about our license +and mit opencourseware in general is + + align:start position:0% +and mit opencourseware in general is + + + align:start position:0% +and mit opencourseware in general is +available at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +and say look i'm writing a term paper + + align:start position:0% +and say look i'm writing a term paper + + + align:start position:0% +and say look i'm writing a term paper +on your article you know + + align:start position:0% +on your article you know + + + align:start position:0% +on your article you know +like to ask you a few questions + + align:start position:0% +like to ask you a few questions + + + align:start position:0% +like to ask you a few questions +uh because if when it comes to + + align:start position:0% +uh because if when it comes to + + + align:start position:0% +uh because if when it comes to +engineering ethics there's about a uh if + + align:start position:0% +engineering ethics there's about a uh if + + + align:start position:0% +engineering ethics there's about a uh if +it's strictly engineering ethics as + + align:start position:0% +it's strictly engineering ethics as + + + align:start position:0% +it's strictly engineering ethics as +opposed to + + align:start position:0% +opposed to + + + align:start position:0% +opposed to +other kinds of i mean the more general + + align:start position:0% +other kinds of i mean the more general + + + align:start position:0% +other kinds of i mean the more general +ethics + + align:start position:0% +ethics + + + align:start position:0% +ethics +there's a 90 chance that i will know who + + align:start position:0% +there's a 90 chance that i will know who + + + align:start position:0% +there's a 90 chance that i will know who +you're + + align:start position:0% +you're + + + align:start position:0% +you're +or the author of who you're talking + + align:start position:0% +or the author of who you're talking + + + align:start position:0% +or the author of who you're talking +about + + align:start position:0% +about + + + align:start position:0% +about +tell you a little bit where they're + + align:start position:0% +tell you a little bit where they're + + + align:start position:0% +tell you a little bit where they're +coming from and invite you to call them + + align:start position:0% + + + + align:start position:0% + +okay well uh we got a good day today + + align:start position:0% +okay well uh we got a good day today + + + align:start position:0% +okay well uh we got a good day today +uh what i'd like to do is to i'm giving + + align:start position:0% +uh what i'd like to do is to i'm giving + + + align:start position:0% +uh what i'd like to do is to i'm giving +your papers back what i'd like to do is + + align:start position:0% +your papers back what i'd like to do is + + + align:start position:0% +your papers back what i'd like to do is +to review the papers but i want your + + align:start position:0% +to review the papers but i want your + + + align:start position:0% +to review the papers but i want your +permission + + align:start position:0% +permission + + + align:start position:0% +permission +what i want to do is to make an + + align:start position:0% +what i want to do is to make an + + + align:start position:0% +what i want to do is to make an +anonymous review but i want to make it + + align:start position:0% +anonymous review but i want to make it + + + align:start position:0% +anonymous review but i want to make it +public i want to read it out to + + align:start position:0% +public i want to read it out to + + + align:start position:0% +public i want to read it out to +everybody nobody will know who said what + + align:start position:0% + + + + align:start position:0% + +there's only two of us + + align:start position:0% +there's only two of us + + + align:start position:0% +there's only two of us +well they don't know which one of you + + align:start position:0% +well they don't know which one of you + + + align:start position:0% +well they don't know which one of you +i'll tell you what it's not it doesn't i + + align:start position:0% +i'll tell you what it's not it doesn't i + + + align:start position:0% +i'll tell you what it's not it doesn't i +don't care + + align:start position:0% +don't care + + + align:start position:0% +don't care +well let's see let's see how it goes i i + + align:start position:0% +well let's see let's see how it goes i i + + + align:start position:0% +well let's see let's see how it goes i i +there's nothing in here that's gonna + + align:start position:0% +there's nothing in here that's gonna + + + align:start position:0% +there's nothing in here that's gonna +that i have to say that's gonna be you + + align:start position:0% +that i have to say that's gonna be you + + + align:start position:0% +that i have to say that's gonna be you +know + + align:start position:0% +know + + + align:start position:0% +know +um + + align:start position:0% +um + + + align:start position:0% +um +uh + + align:start position:0% +uh + + + align:start position:0% +uh +anything that's uh + + align:start position:0% + + + + align:start position:0% + +well let me use some judgment and see + + align:start position:0% +well let me use some judgment and see + + + align:start position:0% +well let me use some judgment and see +how it goes + + align:start position:0% +how it goes + + + align:start position:0% +how it goes +um + + align:start position:0% +um + + + align:start position:0% +um +and + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +now what i want you to do is i'm gonna + + align:start position:0% +now what i want you to do is i'm gonna + + + align:start position:0% +now what i want you to do is i'm gonna +the grade that i have put down here + + align:start position:0% +the grade that i have put down here + + + align:start position:0% +the grade that i have put down here +uh + + align:start position:0% +uh + + + align:start position:0% +uh +is not the grade for the paper you gave + + align:start position:0% +is not the grade for the paper you gave + + + align:start position:0% +is not the grade for the paper you gave +me + + align:start position:0% +me + + + align:start position:0% +me +the grade that i put down here is for + + align:start position:0% +the grade that i put down here is for + + + align:start position:0% +the grade that i put down here is for +your second draft + + align:start position:0% + + + + align:start position:0% + +that will respond to my comments + + align:start position:0% +that will respond to my comments + + + align:start position:0% +that will respond to my comments +and that you can save you don't give + + align:start position:0% +and that you can save you don't give + + + align:start position:0% +and that you can save you don't give +back to me but you can say but you can + + align:start position:0% +back to me but you can say but you can + + + align:start position:0% +back to me but you can say but you can +talk to me about it + + align:start position:0% +talk to me about it + + + align:start position:0% +talk to me about it +okay uh as we go along in other words i + + align:start position:0% +okay uh as we go along in other words i + + + align:start position:0% +okay uh as we go along in other words i +want to + + align:start position:0% +want to + + + align:start position:0% +want to +i said the beginning of class i want to + + align:start position:0% +i said the beginning of class i want to + + + align:start position:0% +i said the beginning of class i want to +see improve + + align:start position:0% +see improve + + + align:start position:0% +see improve +all right so i want you to feel like you + + align:start position:0% +all right so i want you to feel like you + + + align:start position:0% +all right so i want you to feel like you +can doctor this thing up a little bit + + align:start position:0% +can doctor this thing up a little bit + + + align:start position:0% +can doctor this thing up a little bit +okay uh i marked good in several cases + + align:start position:0% +okay uh i marked good in several cases + + + align:start position:0% +okay uh i marked good in several cases +on both papers because mainly because + + align:start position:0% + + + + align:start position:0% + +not because you made good uh + + align:start position:0% +not because you made good uh + + + align:start position:0% +not because you made good uh +observations which you did + + align:start position:0% +observations which you did + + + align:start position:0% +observations which you did +and good thoughts gave me some good + + align:start position:0% +and good thoughts gave me some good + + + align:start position:0% +and good thoughts gave me some good +thoughts but i was actually surprised + + align:start position:0% +thoughts but i was actually surprised + + + align:start position:0% +thoughts but i was actually surprised +positively surprised by the good + + align:start position:0% +positively surprised by the good + + + align:start position:0% +positively surprised by the good +thoughts that both of you had put in + + align:start position:0% +thoughts that both of you had put in + + + align:start position:0% +thoughts that both of you had put in +here + + align:start position:0% +here + + + align:start position:0% +here +but it was little things like + + align:start position:0% +but it was little things like + + + align:start position:0% +but it was little things like +that you did get a reference that i had + + align:start position:0% +that you did get a reference that i had + + + align:start position:0% +that you did get a reference that i had +not brought in and you did it on your + + align:start position:0% +not brought in and you did it on your + + + align:start position:0% +not brought in and you did it on your +own that was good okay and for example + + align:start position:0% +own that was good okay and for example + + + align:start position:0% +own that was good okay and for example +um i didn't make a distinction + + align:start position:0% +um i didn't make a distinction + + + align:start position:0% +um i didn't make a distinction +uh between um + + align:start position:0% +uh between um + + + align:start position:0% +uh between um +act and rule utilitarianism + + align:start position:0% +act and rule utilitarianism + + + align:start position:0% +act and rule utilitarianism +and you all figure that out + + align:start position:0% +and you all figure that out + + + align:start position:0% +and you all figure that out +that's the kind of stuff i'm looking for + + align:start position:0% +that's the kind of stuff i'm looking for + + + align:start position:0% +that's the kind of stuff i'm looking for +uh + + align:start position:0% +uh + + + align:start position:0% +uh +another one is an anomaly uh that's just + + align:start position:0% +another one is an anomaly uh that's just + + + align:start position:0% +another one is an anomaly uh that's just +in the field let me tell you let me give + + align:start position:0% +in the field let me tell you let me give + + + align:start position:0% +in the field let me tell you let me give +you something to remember that we that + + align:start position:0% +you something to remember that we that + + + align:start position:0% +you something to remember that we that +will cause you to remember it + + align:start position:0% +will cause you to remember it + + + align:start position:0% +will cause you to remember it +it's a little game that you can play + + align:start position:0% +it's a little game that you can play + + + align:start position:0% +it's a little game that you can play +with three-year-olds + + align:start position:0% +with three-year-olds + + + align:start position:0% +with three-year-olds +you ever play y'all play around with + + align:start position:0% +you ever play y'all play around with + + + align:start position:0% +you ever play y'all play around with +kids + + align:start position:0% +kids + + + align:start position:0% +kids +three-year-olds four-year-olds it's a + + align:start position:0% +three-year-olds four-year-olds it's a + + + align:start position:0% +three-year-olds four-year-olds it's a +little game but it is very my experience + + align:start position:0% +little game but it is very my experience + + + align:start position:0% +little game but it is very my experience +with telling it we're playing this game + + align:start position:0% +with telling it we're playing this game + + + align:start position:0% +with telling it we're playing this game +with these little kids is very + + align:start position:0% +with these little kids is very + + + align:start position:0% +with these little kids is very +very interesting + + align:start position:0% +very interesting + + + align:start position:0% +very interesting +and that is you sit you say + + align:start position:0% + + + + align:start position:0% + +what has a big head + + align:start position:0% +what has a big head + + + align:start position:0% +what has a big head +red eyes and each rocks + + align:start position:0% +red eyes and each rocks + + + align:start position:0% +red eyes and each rocks +kisses i don't know + + align:start position:0% +kisses i don't know + + + align:start position:0% +kisses i don't know +you say a big headed red eyed rock eater + + align:start position:0% +you say a big headed red eyed rock eater + + + align:start position:0% +you say a big headed red eyed rock eater +because it's okay + + align:start position:0% +because it's okay + + + align:start position:0% +because it's okay +then you say what has a big a big head + + align:start position:0% +then you say what has a big a big head + + + align:start position:0% +then you say what has a big a big head +yellow eyes at these rocks + + align:start position:0% +yellow eyes at these rocks + + + align:start position:0% +yellow eyes at these rocks +and the kid says a big-headed + + align:start position:0% +and the kid says a big-headed + + + align:start position:0% +and the kid says a big-headed +yellow-eyed + + align:start position:0% +yellow-eyed + + + align:start position:0% +yellow-eyed +rock eater + + align:start position:0% +rock eater + + + align:start position:0% +rock eater +you say no + + align:start position:0% +you say no + + + align:start position:0% +you say no +they only come in red + + align:start position:0% +they only come in red + + + align:start position:0% +they only come in red +now + + align:start position:0% +now + + + align:start position:0% +now +or + + align:start position:0% +or + + + align:start position:0% +or +my experience is that four-year-olds see + + align:start position:0% +my experience is that four-year-olds see + + + align:start position:0% +my experience is that four-year-olds see +the point to that that's just the way + + align:start position:0% +the point to that that's just the way + + + align:start position:0% +the point to that that's just the way +life is + + align:start position:0% +life is + + + align:start position:0% +life is +okay + + align:start position:0% +okay + + + align:start position:0% +okay +all right + + align:start position:0% + + + + align:start position:0% + +now in ethics you'll find a lot of this + + align:start position:0% +now in ethics you'll find a lot of this + + + align:start position:0% +now in ethics you'll find a lot of this +you'll find deontological ethics + + align:start position:0% +you'll find deontological ethics + + + align:start position:0% +you'll find deontological ethics +but nobody very few people not a lot of + + align:start position:0% +but nobody very few people not a lot of + + + align:start position:0% +but nobody very few people not a lot of +people talk about ontological ethics + + align:start position:0% +people talk about ontological ethics + + + align:start position:0% +people talk about ontological ethics +don't be bothered by that + + align:start position:0% +don't be bothered by that + + + align:start position:0% +don't be bothered by that +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and there'll be a lot of those + + align:start position:0% +and there'll be a lot of those + + + align:start position:0% +and there'll be a lot of those +there'll be a lot of uh let me see if i + + align:start position:0% +there'll be a lot of uh let me see if i + + + align:start position:0% +there'll be a lot of uh let me see if i +can think of another one um + + align:start position:0% + + + + align:start position:0% + +they'll talk about consequentialist and + + align:start position:0% +they'll talk about consequentialist and + + + align:start position:0% +they'll talk about consequentialist and +non-consequentials + + align:start position:0% +non-consequentials + + + align:start position:0% +non-consequentials +but there's another one i'll think of it + + align:start position:0% +but there's another one i'll think of it + + + align:start position:0% +but there's another one i'll think of it +before the class is over but there are a + + align:start position:0% +before the class is over but there are a + + + align:start position:0% +before the class is over but there are a +lot of these little anomaly anomalies + + align:start position:0% +lot of these little anomaly anomalies + + + align:start position:0% +lot of these little anomaly anomalies +just don't let them bother you but pick + + align:start position:0% +just don't let them bother you but pick + + + align:start position:0% +just don't let them bother you but pick +them up pick them up + + align:start position:0% +them up pick them up + + + align:start position:0% +them up pick them up +okay + + align:start position:0% +okay + + + align:start position:0% +okay +another thing is um + + align:start position:0% +another thing is um + + + align:start position:0% +another thing is um +that this case is more properly called + + align:start position:0% +that this case is more properly called + + + align:start position:0% +that this case is more properly called +the a7d case + + align:start position:0% +the a7d case + + + align:start position:0% +the a7d case +than the a7 case + + align:start position:0% + + + + align:start position:0% + +it's the nomenclature + + align:start position:0% +it's the nomenclature + + + align:start position:0% +it's the nomenclature +for the for the uh for the break + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% +um + + + align:start position:0% +um +the uh + + align:start position:0% +the uh + + + align:start position:0% +the uh +now here's here's one here's a very + + align:start position:0% +now here's here's one here's a very + + + align:start position:0% +now here's here's one here's a very +significant teaching point + + align:start position:0% + + + + align:start position:0% + +very significant + + align:start position:0% +very significant + + + align:start position:0% +very significant +teaching point for this kind of class + + align:start position:0% +teaching point for this kind of class + + + align:start position:0% +teaching point for this kind of class +on the one hand + + align:start position:0% +on the one hand + + + align:start position:0% +on the one hand +a prescription for behavior + + align:start position:0% +a prescription for behavior + + + align:start position:0% +a prescription for behavior +is made more compelling + + align:start position:0% +is made more compelling + + + align:start position:0% +is made more compelling +i agree + + align:start position:0% +i agree + + + align:start position:0% +i agree +if you use two very different approaches + + align:start position:0% +if you use two very different approaches + + + align:start position:0% +if you use two very different approaches +and come up with the same prescription + + align:start position:0% +and come up with the same prescription + + + align:start position:0% +and come up with the same prescription +that's very compelling + + align:start position:0% + + + + align:start position:0% + +but in ethics there's no reason + + align:start position:0% +but in ethics there's no reason + + + align:start position:0% +but in ethics there's no reason +that two prescriptions should be the + + align:start position:0% +that two prescriptions should be the + + + align:start position:0% +that two prescriptions should be the +same + + align:start position:0% + + + + align:start position:0% + +if you get different prescriptions you + + align:start position:0% +if you get different prescriptions you + + + align:start position:0% +if you get different prescriptions you +don't have to say you need more work + + align:start position:0% +don't have to say you need more work + + + align:start position:0% +don't have to say you need more work +that's that's the way it can end + + align:start position:0% +that's that's the way it can end + + + align:start position:0% +that's that's the way it can end +okay what you're really looking for is + + align:start position:0% +okay what you're really looking for is + + + align:start position:0% +okay what you're really looking for is +the defensibility of it + + align:start position:0% +the defensibility of it + + + align:start position:0% +the defensibility of it +so um i could give you a classic case + + align:start position:0% +so um i could give you a classic case + + + align:start position:0% +so um i could give you a classic case +one that i think you should think over + + align:start position:0% +one that i think you should think over + + + align:start position:0% +one that i think you should think over +if you had probably one that you thought + + align:start position:0% +if you had probably one that you thought + + + align:start position:0% +if you had probably one that you thought +of before + + align:start position:0% +of before + + + align:start position:0% +of before +it doesn't have a name but uh you've + + align:start position:0% +it doesn't have a name but uh you've + + + align:start position:0% +it doesn't have a name but uh you've +seen it in movies uh + + align:start position:0% +seen it in movies uh + + + align:start position:0% +seen it in movies uh +a + + align:start position:0% +a + + + align:start position:0% +a +ship sinks + + align:start position:0% +ship sinks + + + align:start position:0% +ship sinks +some people escape in a lifeboat + + align:start position:0% +some people escape in a lifeboat + + + align:start position:0% +some people escape in a lifeboat +there are 10 people in the lifeboat + + align:start position:0% +there are 10 people in the lifeboat + + + align:start position:0% +there are 10 people in the lifeboat +there's food enough + + align:start position:0% +there's food enough + + + align:start position:0% +there's food enough +for 10 people for a week but they don't + + align:start position:0% +for 10 people for a week but they don't + + + align:start position:0% +for 10 people for a week but they don't +expect to be picked up for a month + + align:start position:0% + + + + align:start position:0% + +well you can come up come up with a + + align:start position:0% +well you can come up come up with a + + + align:start position:0% +well you can come up come up with a +whole lot of solutions + + align:start position:0% +whole lot of solutions + + + align:start position:0% +whole lot of solutions +that are very different even opposite + + align:start position:0% +that are very different even opposite + + + align:start position:0% +that are very different even opposite +and all of them are equally defensible + + align:start position:0% + + + + align:start position:0% + +you can come up with some solutions you + + align:start position:0% +you can come up with some solutions you + + + align:start position:0% +you can come up with some solutions you +can come up + + align:start position:0% +can come up + + + align:start position:0% +can come up +you can come up with a solution + + align:start position:0% +you can come up with a solution + + + align:start position:0% +you can come up with a solution +that is defensible i can come up with + + align:start position:0% +that is defensible i can come up with + + + align:start position:0% +that is defensible i can come up with +the same solution that is not defensive + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +all right so i + + align:start position:0% +all right so i + + + align:start position:0% +all right so i +in an engineering class we + + align:start position:0% +in an engineering class we + + + align:start position:0% +in an engineering class we +um uh + + align:start position:0% +um uh + + + align:start position:0% +um uh +well let's put it this way in + + align:start position:0% +well let's put it this way in + + + align:start position:0% +well let's put it this way in +undergraduate engineering + + align:start position:0% + + + + align:start position:0% + +there is such a thing as the answer in + + align:start position:0% +there is such a thing as the answer in + + + align:start position:0% +there is such a thing as the answer in +the back of the book + + align:start position:0% +the back of the book + + + align:start position:0% +the back of the book +the operative word is the + + align:start position:0% +the operative word is the + + + align:start position:0% +the operative word is the +okay + + align:start position:0% +okay + + + align:start position:0% +okay +in graduate + + align:start position:0% +in graduate + + + align:start position:0% +in graduate +you're going to find you can get more + + align:start position:0% +you're going to find you can get more + + + align:start position:0% +you're going to find you can get more +than one answer + + align:start position:0% +than one answer + + + align:start position:0% +than one answer +and there's cost and benefits + + align:start position:0% +and there's cost and benefits + + + align:start position:0% +and there's cost and benefits +on either side + + align:start position:0% +on either side + + + align:start position:0% +on either side +out there + + align:start position:0% + + + + align:start position:0% + +a lot of good answers a lot of bad + + align:start position:0% +a lot of good answers a lot of bad + + + align:start position:0% +a lot of good answers a lot of bad +answers + + align:start position:0% +answers + + + align:start position:0% +answers +and what is going to count most in many + + align:start position:0% +and what is going to count most in many + + + align:start position:0% +and what is going to count most in many +situations + + align:start position:0% +situations + + + align:start position:0% +situations +is like it is here + + align:start position:0% +is like it is here + + + align:start position:0% +is like it is here +it's your argument + + align:start position:0% + + + + align:start position:0% + +uh and that's going to be because and + + align:start position:0% +uh and that's going to be because and + + + align:start position:0% +uh and that's going to be because and +and this is one thing that i try to + + align:start position:0% +and this is one thing that i try to + + + align:start position:0% +and this is one thing that i try to +direct my class to + + align:start position:0% +direct my class to + + + align:start position:0% +direct my class to +because + + align:start position:0% + + + + align:start position:0% + +people just will not know + + align:start position:0% + + + + align:start position:0% + +no matter what you say + + align:start position:0% +no matter what you say + + + align:start position:0% +no matter what you say +what the right answer is + + align:start position:0% +what the right answer is + + + align:start position:0% +what the right answer is +the question let me tell you a story i + + align:start position:0% +the question let me tell you a story i + + + align:start position:0% +the question let me tell you a story i +got another story let me just tell this + + align:start position:0% +got another story let me just tell this + + + align:start position:0% +got another story let me just tell this +story + + align:start position:0% +story + + + align:start position:0% +story +uh i'm a young assistant professor + + align:start position:0% +uh i'm a young assistant professor + + + align:start position:0% +uh i'm a young assistant professor +and i'm down there and i go down to um + + align:start position:0% +and i'm down there and i go down to um + + + align:start position:0% +and i'm down there and i go down to um +nasa langley research center this is in + + align:start position:0% +nasa langley research center this is in + + + align:start position:0% +nasa langley research center this is in +hampton virginia + + align:start position:0% +hampton virginia + + + align:start position:0% +hampton virginia +know about it + + align:start position:0% +know about it + + + align:start position:0% +know about it +oh + + align:start position:0% +oh + + + align:start position:0% +oh +two summer internships really what + + align:start position:0% +two summer internships really what + + + align:start position:0% +two summer internships really what +division + + align:start position:0% + + + + align:start position:0% + +branch uh + + align:start position:0% + + + + align:start position:0% + +yeah in the building where the mercury + + align:start position:0% +yeah in the building where the mercury + + + align:start position:0% +yeah in the building where the mercury +astronauts were trained whoa + + align:start position:0% +astronauts were trained whoa + + + align:start position:0% +astronauts were trained whoa +i was down there in the late 70s and + + align:start position:0% +i was down there in the late 70s and + + + align:start position:0% +i was down there in the late 70s and +almost all through the 80s + + align:start position:0% +almost all through the 80s + + + align:start position:0% +almost all through the 80s +i had grants with them for about 12 + + align:start position:0% +i had grants with them for about 12 + + + align:start position:0% +i had grants with them for about 12 +years + + align:start position:0% +years + + + align:start position:0% +years +uh + + align:start position:0% +uh + + + align:start position:0% +uh +and i and i had a relationship down + + align:start position:0% +and i and i had a relationship down + + + align:start position:0% +and i and i had a relationship down +there where + + align:start position:0% +there where + + + align:start position:0% +there where +i was going down there so often that + + align:start position:0% +i was going down there so often that + + + align:start position:0% +i was going down there so often that +what i do is rent a house i take + + align:start position:0% +what i do is rent a house i take + + + align:start position:0% +what i do is rent a house i take +students with me + + align:start position:0% +students with me + + + align:start position:0% +students with me +we live in the house + + align:start position:0% +we live in the house + + + align:start position:0% +we live in the house +work + + align:start position:0% +work + + + align:start position:0% +work +and um i did that uh + + align:start position:0% +and um i did that uh + + + align:start position:0% +and um i did that uh +eight or nine years i guess + + align:start position:0% + + + + align:start position:0% + +and so we would all get in the car + + align:start position:0% + + + + align:start position:0% + +and ride down there and + + align:start position:0% +and ride down there and + + + align:start position:0% +and ride down there and +i had this little speech i'd give + + align:start position:0% +i had this little speech i'd give + + + align:start position:0% +i had this little speech i'd give +and i was unmarried at the time + + align:start position:0% +and i was unmarried at the time + + + align:start position:0% +and i was unmarried at the time +and i would tell them + + align:start position:0% +and i would tell them + + + align:start position:0% +and i would tell them +whatever happens in hampton + + align:start position:0% +whatever happens in hampton + + + align:start position:0% +whatever happens in hampton +stays in him + + align:start position:0% +stays in him + + + align:start position:0% +stays in him +okay i don't want any students coming + + align:start position:0% +okay i don't want any students coming + + + align:start position:0% +okay i don't want any students coming +back to howard saying i saw dr broome + + align:start position:0% +back to howard saying i saw dr broome + + + align:start position:0% +back to howard saying i saw dr broome +i said whatever happens down there stays + + align:start position:0% +i said whatever happens down there stays + + + align:start position:0% +i said whatever happens down there stays +there + + align:start position:0% +there + + + align:start position:0% +there +so one year we were riding down there + + align:start position:0% +so one year we were riding down there + + + align:start position:0% +so one year we were riding down there +i was riding down there with four three + + align:start position:0% +i was riding down there with four three + + + align:start position:0% +i was riding down there with four three +students four students + + align:start position:0% +students four students + + + align:start position:0% +students four students +three students + + align:start position:0% +three students + + + align:start position:0% +three students +and uh i made my little speech + + align:start position:0% +and uh i made my little speech + + + align:start position:0% +and uh i made my little speech +they agreed with it + + align:start position:0% +they agreed with it + + + align:start position:0% +they agreed with it +and then one of them said does that go + + align:start position:0% +and then one of them said does that go + + + align:start position:0% +and then one of them said does that go +for us too + + align:start position:0% +for us too + + + align:start position:0% +for us too +and i thought there's never a case where + + align:start position:0% +and i thought there's never a case where + + + align:start position:0% +and i thought there's never a case where +i go back to howard deal with students + + align:start position:0% +i go back to howard deal with students + + + align:start position:0% +i go back to howard deal with students +you know i don't care what they did i + + align:start position:0% +you know i don't care what they did i + + + align:start position:0% +you know i don't care what they did i +just don't + + align:start position:0% +just don't + + + align:start position:0% +just don't +do it + + align:start position:0% +do it + + + align:start position:0% +do it +so + + align:start position:0% +so + + + align:start position:0% +so +i said yeah i guess it goes for you too + + align:start position:0% +i said yeah i guess it goes for you too + + + align:start position:0% +i said yeah i guess it goes for you too +so they started lighting up these reefs + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +i said oh my god what have i got myself + + align:start position:0% +i said oh my god what have i got myself + + + align:start position:0% +i said oh my god what have i got myself +into then the police came + + align:start position:0% +into then the police came + + + align:start position:0% +into then the police came +it was because they were speaking + + align:start position:0% +it was because they were speaking + + + align:start position:0% +it was because they were speaking +and + + align:start position:0% +and + + + align:start position:0% +and +we had they and there's a place in + + align:start position:0% +we had they and there's a place in + + + align:start position:0% +we had they and there's a place in +virginia i'm gonna tell you right now + + align:start position:0% +virginia i'm gonna tell you right now + + + align:start position:0% +virginia i'm gonna tell you right now +it's called uh + + align:start position:0% + + + + align:start position:0% + +it's called uh + + align:start position:0% +it's called uh + + + align:start position:0% +it's called uh +what's it called + + align:start position:0% +what's it called + + + align:start position:0% +what's it called +i can't think of anybody but there's a + + align:start position:0% +i can't think of anybody but there's a + + + align:start position:0% +i can't think of anybody but there's a +place in virginia where if the police + + align:start position:0% +place in virginia where if the police + + + align:start position:0% +place in virginia where if the police +get you for speeding they don't give you + + align:start position:0% +get you for speeding they don't give you + + + align:start position:0% +get you for speeding they don't give you +a ticket on the spot + + align:start position:0% +a ticket on the spot + + + align:start position:0% +a ticket on the spot +they take you about 10 miles off the + + align:start position:0% +they take you about 10 miles off the + + + align:start position:0% +they take you about 10 miles off the +road to a special place + + align:start position:0% +road to a special place + + + align:start position:0% +road to a special place +where you have to fill out a form + + align:start position:0% +where you have to fill out a form + + + align:start position:0% +where you have to fill out a form +and you have to pay in cash + + align:start position:0% +and you have to pay in cash + + + align:start position:0% +and you have to pay in cash +he took us off and i said i know i'm + + align:start position:0% +he took us off and i said i know i'm + + + align:start position:0% +he took us off and i said i know i'm +going to jail + + align:start position:0% +going to jail + + + align:start position:0% +going to jail +that was 30 years ago + + align:start position:0% +that was 30 years ago + + + align:start position:0% +that was 30 years ago +but um + + align:start position:0% +but um + + + align:start position:0% +but um +we got that the story is that that one + + align:start position:0% +we got that the story is that that one + + + align:start position:0% +we got that the story is that that one +day i went to what's called a division + + align:start position:0% +day i went to what's called a division + + + align:start position:0% +day i went to what's called a division +meeting this was the structures and + + align:start position:0% +meeting this was the structures and + + + align:start position:0% +meeting this was the structures and +dynamics division + + align:start position:0% +dynamics division + + + align:start position:0% +dynamics division +and i had to go to all of the division + + align:start position:0% +and i had to go to all of the division + + + align:start position:0% +and i had to go to all of the division +meetings + + align:start position:0% +meetings + + + align:start position:0% +meetings +and it got mean + + align:start position:0% +and it got mean + + + align:start position:0% +and it got mean +spirited in there that day so you + + align:start position:0% +spirited in there that day so you + + + align:start position:0% +spirited in there that day so you +imagine a room + + align:start position:0% +imagine a room + + + align:start position:0% +imagine a room +there's about 100 engineers + + align:start position:0% +there's about 100 engineers + + + align:start position:0% +there's about 100 engineers +95 of them have phd + + align:start position:0% +95 of them have phd + + + align:start position:0% +95 of them have phd +they call a place a campus when i was + + align:start position:0% +they call a place a campus when i was + + + align:start position:0% +they call a place a campus when i was +there + + align:start position:0% +there + + + align:start position:0% +there +and these engineers were up making a + + align:start position:0% +and these engineers were up making a + + + align:start position:0% +and these engineers were up making a +presentation + + align:start position:0% +presentation + + + align:start position:0% +presentation +and the chief was sitting on the side + + align:start position:0% +and the chief was sitting on the side + + + align:start position:0% +and the chief was sitting on the side +and started quizzing them about it + + align:start position:0% + + + + align:start position:0% + +and it got mean in there + + align:start position:0% +and it got mean in there + + + align:start position:0% +and it got mean in there +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and + + align:start position:0% +and + + + align:start position:0% +and +he hit his hand fist on the table + + align:start position:0% +he hit his hand fist on the table + + + align:start position:0% +he hit his hand fist on the table +and it kept going round and round + + align:start position:0% +and it kept going round and round + + + align:start position:0% +and it kept going round and round +and so uh that was my first meeting i + + align:start position:0% +and so uh that was my first meeting i + + + align:start position:0% +and so uh that was my first meeting i +think and i said my god + + align:start position:0% +think and i said my god + + + align:start position:0% +think and i said my god +if i have to make a presentation in here + + align:start position:0% +if i have to make a presentation in here + + + align:start position:0% +if i have to make a presentation in here +i'm just going to have it ready because + + align:start position:0% +i'm just going to have it ready because + + + align:start position:0% +i'm just going to have it ready because +that was it was awful + + align:start position:0% +that was it was awful + + + align:start position:0% +that was it was awful +awful is the word + + align:start position:0% +awful is the word + + + align:start position:0% +awful is the word +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so after that it was lunch time + + align:start position:0% +so after that it was lunch time + + + align:start position:0% +so after that it was lunch time +went to the cafeteria + + align:start position:0% + + + + align:start position:0% + +and this man + + align:start position:0% +and this man + + + align:start position:0% +and this man +sat at this long table + + align:start position:0% +sat at this long table + + + align:start position:0% +sat at this long table +after he got his tray set at this long + + align:start position:0% +after he got his tray set at this long + + + align:start position:0% +after he got his tray set at this long +table and nobody + + align:start position:0% +table and nobody + + + align:start position:0% +table and nobody +sat with him at that table not from the + + align:start position:0% +sat with him at that table not from the + + + align:start position:0% +sat with him at that table not from the +division + + align:start position:0% +division + + + align:start position:0% +division +not from anyplace else everybody went + + align:start position:0% +not from anyplace else everybody went + + + align:start position:0% +not from anyplace else everybody went +someplace else and said he's sitting + + align:start position:0% +someplace else and said he's sitting + + + align:start position:0% +someplace else and said he's sitting +over there by himself + + align:start position:0% +over there by himself + + + align:start position:0% +over there by himself +so i came up with my tray and i said i + + align:start position:0% +so i came up with my tray and i said i + + + align:start position:0% +so i came up with my tray and i said i +said look um + + align:start position:0% +said look um + + + align:start position:0% +said look um +i said would you mind some company + + align:start position:0% +i said would you mind some company + + + align:start position:0% +i said would you mind some company +no he said + + align:start position:0% +no he said + + + align:start position:0% +no he said +and so i said well i'm down here just + + align:start position:0% +and so i said well i'm down here just + + + align:start position:0% +and so i said well i'm down here just +for as you know just for the summer + + align:start position:0% +for as you know just for the summer + + + align:start position:0% +for as you know just for the summer +maybe next summer too but + + align:start position:0% +maybe next summer too but + + + align:start position:0% +maybe next summer too but +i said this is an opportunity for me to + + align:start position:0% +i said this is an opportunity for me to + + + align:start position:0% +i said this is an opportunity for me to +learn something + + align:start position:0% +learn something + + + align:start position:0% +learn something +i said it was a pretty + + align:start position:0% +i said it was a pretty + + + align:start position:0% +i said it was a pretty +pretty mean meeting you just had + + align:start position:0% +pretty mean meeting you just had + + + align:start position:0% +pretty mean meeting you just had +and i said to him i said + + align:start position:0% + + + + align:start position:0% + +not only that + + align:start position:0% +not only that + + + align:start position:0% +not only that +but + + align:start position:0% +but + + + align:start position:0% +but +it's called a state of space i said + + align:start position:0% +it's called a state of space i said + + + align:start position:0% +it's called a state of space i said +all those phds in there that you're + + align:start position:0% +all those phds in there that you're + + + align:start position:0% +all those phds in there that you're +tearing up and you don't even call the + + align:start position:0% +tearing up and you don't even call the + + + align:start position:0% +tearing up and you don't even call the +phd + + align:start position:0% + + + + align:start position:0% + +masters + + align:start position:0% +masters + + + align:start position:0% +masters +from mit + + align:start position:0% + + + + align:start position:0% + +i said how do you know when they're + + align:start position:0% +i said how do you know when they're + + + align:start position:0% +i said how do you know when they're +right or when they're wrong + + align:start position:0% +right or when they're wrong + + + align:start position:0% +right or when they're wrong +and he said being right or wrong is not + + align:start position:0% +and he said being right or wrong is not + + + align:start position:0% +and he said being right or wrong is not +the issue + + align:start position:0% +the issue + + + align:start position:0% +the issue +he said it's a question of commitment + + align:start position:0% +he said it's a question of commitment + + + align:start position:0% +he said it's a question of commitment +what are they willing to put their + + align:start position:0% +what are they willing to put their + + + align:start position:0% +what are they willing to put their +careers on + + align:start position:0% +careers on + + + align:start position:0% +careers on +he said so i put the heat on them + + align:start position:0% +he said so i put the heat on them + + + align:start position:0% +he said so i put the heat on them +and what i'm looking for is number one + + align:start position:0% +and what i'm looking for is number one + + + align:start position:0% +and what i'm looking for is number one +whether or not they're going to stand by + + align:start position:0% +whether or not they're going to stand by + + + align:start position:0% +whether or not they're going to stand by +what they said or whether they're going + + align:start position:0% +what they said or whether they're going + + + align:start position:0% +what they said or whether they're going +to start back back peddling + + align:start position:0% +to start back back peddling + + + align:start position:0% +to start back back peddling +and number two whether anybody sitting + + align:start position:0% +and number two whether anybody sitting + + + align:start position:0% +and number two whether anybody sitting +out there is going to join them or be + + align:start position:0% +out there is going to join them or be + + + align:start position:0% +out there is going to join them or be +glad it's not them + + align:start position:0% +glad it's not them + + + align:start position:0% +glad it's not them +he said you watched he said i put him + + align:start position:0% +he said you watched he said i put him + + + align:start position:0% +he said you watched he said i put him +under pressure + + align:start position:0% +under pressure + + + align:start position:0% +under pressure +after a while they started back peddling + + align:start position:0% +after a while they started back peddling + + + align:start position:0% +after a while they started back peddling +and nobody came to their aid so we're + + align:start position:0% +and nobody came to their aid so we're + + + align:start position:0% +and nobody came to their aid so we're +not going with those results + + align:start position:0% +not going with those results + + + align:start position:0% +not going with those results +they're probably right + + align:start position:0% +they're probably right + + + align:start position:0% +they're probably right +but we're not going with that + + align:start position:0% +but we're not going with that + + + align:start position:0% +but we're not going with that +he said if they stood up stood up to me + + align:start position:0% +he said if they stood up stood up to me + + + align:start position:0% +he said if they stood up stood up to me +he said he said this is government + + align:start position:0% +he said he said this is government + + + align:start position:0% +he said he said this is government +they know they're going to have there's + + align:start position:0% +they know they're going to have there's + + + align:start position:0% +they know they're going to have there's +going to be a rift coming around in a + + align:start position:0% +going to be a rift coming around in a + + + align:start position:0% +going to be a rift coming around in a +year or so + + align:start position:0% +year or so + + + align:start position:0% +year or so +okay + + align:start position:0% +okay + + + align:start position:0% +okay +these guys he's having fire now + + align:start position:0% + + + + align:start position:0% + +he said but look + + align:start position:0% +he said but look + + + align:start position:0% +he said but look +he said if they had stood up to me + + align:start position:0% +he said if they had stood up to me + + + align:start position:0% +he said if they had stood up to me +and if a couple of them out of the + + align:start position:0% +and if a couple of them out of the + + + align:start position:0% +and if a couple of them out of the +audience stood up and stood with them + + align:start position:0% +audience stood up and stood with them + + + align:start position:0% +audience stood up and stood with them +he said that's what we're going to go + + align:start position:0% +he said that's what we're going to go + + + align:start position:0% +he said that's what we're going to go +with the thing might go up and come back + + align:start position:0% +with the thing might go up and come back + + + align:start position:0% +with the thing might go up and come back +down + + align:start position:0% +down + + + align:start position:0% +down +explode he said but that's the business + + align:start position:0% +explode he said but that's the business + + + align:start position:0% +explode he said but that's the business +we're in this is the real world of + + align:start position:0% +we're in this is the real world of + + + align:start position:0% +we're in this is the real world of +engineering + + align:start position:0% +engineering + + + align:start position:0% +engineering +it's the commitment that counts + + align:start position:0% + + + + align:start position:0% + +and we got good people out here + + align:start position:0% +and we got good people out here + + + align:start position:0% +and we got good people out here +and if they are willing to commit + + align:start position:0% +and if they are willing to commit + + + align:start position:0% +and if they are willing to commit +then the united states will say + + align:start position:0% +then the united states will say + + + align:start position:0% +then the united states will say +when the thing goes up and explodes they + + align:start position:0% +when the thing goes up and explodes they + + + align:start position:0% +when the thing goes up and explodes they +will say here's some more money try it + + align:start position:0% +will say here's some more money try it + + + align:start position:0% +will say here's some more money try it +again + + align:start position:0% + + + + align:start position:0% + +but if we + + align:start position:0% +but if we + + + align:start position:0% +but if we +having the right answers is not the + + align:start position:0% +having the right answers is not the + + + align:start position:0% +having the right answers is not the +whole story not even the main story when + + align:start position:0% +whole story not even the main story when + + + align:start position:0% +whole story not even the main story when +you particularly talk about space + + align:start position:0% +you particularly talk about space + + + align:start position:0% +you particularly talk about space +where you don't have a tradition + + align:start position:0% +where you don't have a tradition + + + align:start position:0% +where you don't have a tradition +everything you're doing this for the + + align:start position:0% +everything you're doing this for the + + + align:start position:0% +everything you're doing this for the +first time + + align:start position:0% +first time + + + align:start position:0% +first time +okay so that's the real world + + align:start position:0% +okay so that's the real world + + + align:start position:0% +okay so that's the real world +now the good news is + + align:start position:0% +now the good news is + + + align:start position:0% +now the good news is +the bad news is that undergraduate + + align:start position:0% +the bad news is that undergraduate + + + align:start position:0% +the bad news is that undergraduate +education is not like that + + align:start position:0% +education is not like that + + + align:start position:0% +education is not like that +uh + + align:start position:0% +uh + + + align:start position:0% +uh +semi depends on who your major professor + + align:start position:0% +semi depends on who your major professor + + + align:start position:0% +semi depends on who your major professor +is graduate education is not like that + + align:start position:0% +is graduate education is not like that + + + align:start position:0% +is graduate education is not like that +in engineering + + align:start position:0% +in engineering + + + align:start position:0% +in engineering +but from day one ethics education is + + align:start position:0% +but from day one ethics education is + + + align:start position:0% +but from day one ethics education is +like that + + align:start position:0% +like that + + + align:start position:0% +like that +because we want we want a good answer + + align:start position:0% +because we want we want a good answer + + + align:start position:0% +because we want we want a good answer +now don't get to get me wrong okay + + align:start position:0% +now don't get to get me wrong okay + + + align:start position:0% +now don't get to get me wrong okay +but it's that i he made up to it and + + align:start position:0% +but it's that i he made up to it and + + + align:start position:0% +but it's that i he made up to it and +whether or not as i'm grading it and as + + align:start position:0% +whether or not as i'm grading it and as + + + align:start position:0% +whether or not as i'm grading it and as +any other professor with greater whether + + align:start position:0% +any other professor with greater whether + + + align:start position:0% +any other professor with greater whether +or not i would commit me + + align:start position:0% +or not i would commit me + + + align:start position:0% +or not i would commit me +and my kids + + align:start position:0% +and my kids + + + align:start position:0% +and my kids +to your answers + + align:start position:0% +to your answers + + + align:start position:0% +to your answers +to your analysis + + align:start position:0% +to your analysis + + + align:start position:0% +to your analysis +because my kids are going to have to + + align:start position:0% +because my kids are going to have to + + + align:start position:0% +because my kids are going to have to +cross that bridge + + align:start position:0% +cross that bridge + + + align:start position:0% +cross that bridge +okay and so uh now + + align:start position:0% +okay and so uh now + + + align:start position:0% +okay and so uh now +i'm interested that you got everything + + align:start position:0% +i'm interested that you got everything + + + align:start position:0% +i'm interested that you got everything +written down + + align:start position:0% +written down + + + align:start position:0% +written down +but there's got to be something under it + + align:start position:0% +but there's got to be something under it + + + align:start position:0% +but there's got to be something under it +that's compelling + + align:start position:0% +that's compelling + + + align:start position:0% +that's compelling +and that is impossible to grade + + align:start position:0% +and that is impossible to grade + + + align:start position:0% +and that is impossible to grade +but i can tell you whether or not it's + + align:start position:0% +but i can tell you whether or not it's + + + align:start position:0% +but i can tell you whether or not it's +there i can tell you whether or not i + + align:start position:0% +there i can tell you whether or not i + + + align:start position:0% +there i can tell you whether or not i +feel it + + align:start position:0% +feel it + + + align:start position:0% +feel it +and i and most importantly + + align:start position:0% +and i and most importantly + + + align:start position:0% +and i and most importantly +even if i don't feel it i've been out + + align:start position:0% +even if i don't feel it i've been out + + + align:start position:0% +even if i don't feel it i've been out +here long enough to know whether + + align:start position:0% +here long enough to know whether + + + align:start position:0% +here long enough to know whether +somebody else will + + align:start position:0% +somebody else will + + + align:start position:0% +somebody else will +i would say yeah there's some people out + + align:start position:0% +i would say yeah there's some people out + + + align:start position:0% +i would say yeah there's some people out +here that would really feel this + + align:start position:0% +here that would really feel this + + + align:start position:0% +here that would really feel this +but that takes time + + align:start position:0% +but that takes time + + + align:start position:0% +but that takes time +my objective in this class is not to + + align:start position:0% +my objective in this class is not to + + + align:start position:0% +my objective in this class is not to +meet that objective + + align:start position:0% +meet that objective + + + align:start position:0% +meet that objective +it's the first time you've had a + + align:start position:0% +it's the first time you've had a + + + align:start position:0% +it's the first time you've had a +engineering ethics course + + align:start position:0% +engineering ethics course + + + align:start position:0% +engineering ethics course +and if this was a sequence then i would + + align:start position:0% +and if this was a sequence then i would + + + align:start position:0% +and if this was a sequence then i would +expect it the next time + + align:start position:0% +expect it the next time + + + align:start position:0% +expect it the next time +it's my objective in this class to talk + + align:start position:0% +it's my objective in this class to talk + + + align:start position:0% +it's my objective in this class to talk +about it + + align:start position:0% +about it + + + align:start position:0% +about it +okay + + align:start position:0% +okay + + + align:start position:0% +okay +um + + align:start position:0% + + + + align:start position:0% + +let's see uh + + align:start position:0% + + + + align:start position:0% + +yes a few comments um + + align:start position:0% + + + + align:start position:0% + +emmanuel kant takes his + + align:start position:0% +emmanuel kant takes his + + + align:start position:0% +emmanuel kant takes his +uh categorical uh imperative + + align:start position:0% +uh categorical uh imperative + + + align:start position:0% +uh categorical uh imperative +and states it three or four different + + align:start position:0% +and states it three or four different + + + align:start position:0% +and states it three or four different +ways now i think you all picked that up + + align:start position:0% +ways now i think you all picked that up + + + align:start position:0% +ways now i think you all picked that up +there's a subtlety in one of them + + align:start position:0% + + + + align:start position:0% + +the golden rule is one of those + + align:start position:0% +the golden rule is one of those + + + align:start position:0% +the golden rule is one of those +statements + + align:start position:0% +statements + + + align:start position:0% +statements +so tie that in to comp + + align:start position:0% +so tie that in to comp + + + align:start position:0% +so tie that in to comp +go he explicitly says that the golden + + align:start position:0% +go he explicitly says that the golden + + + align:start position:0% +go he explicitly says that the golden +rule + + align:start position:0% +rule + + + align:start position:0% +rule +is a legitimate statement of the + + align:start position:0% +is a legitimate statement of the + + + align:start position:0% +is a legitimate statement of the +categorical imperative + + align:start position:0% + + + + align:start position:0% + +now so what that means is that out of + + align:start position:0% +now so what that means is that out of + + + align:start position:0% +now so what that means is that out of +the different + + align:start position:0% +the different + + + align:start position:0% +the different +formulations of his categorical + + align:start position:0% +formulations of his categorical + + + align:start position:0% +formulations of his categorical +imperative you can pick any one of them + + align:start position:0% +imperative you can pick any one of them + + + align:start position:0% +imperative you can pick any one of them +i'm not too sure that a philosopher + + align:start position:0% +i'm not too sure that a philosopher + + + align:start position:0% +i'm not too sure that a philosopher +would say that one is better than the + + align:start position:0% +would say that one is better than the + + + align:start position:0% +would say that one is better than the +other + + align:start position:0% +other + + + align:start position:0% +other +just different ways of stating the thing + + align:start position:0% +just different ways of stating the thing + + + align:start position:0% +just different ways of stating the thing +properly because it's a complicated sort + + align:start position:0% +properly because it's a complicated sort + + + align:start position:0% +properly because it's a complicated sort +of thing + + align:start position:0% +of thing + + + align:start position:0% +of thing +uh + + align:start position:0% +uh + + + align:start position:0% +uh +my i guess you all know which which one + + align:start position:0% +my i guess you all know which which one + + + align:start position:0% +my i guess you all know which which one +is my preference treating people is + + align:start position:0% +is my preference treating people is + + + align:start position:0% +is my preference treating people is +means to end + + align:start position:0% +means to end + + + align:start position:0% +means to end +that's my that's my preference um the + + align:start position:0% +that's my that's my preference um the + + + align:start position:0% +that's my that's my preference um the +first one + + align:start position:0% +first one + + + align:start position:0% +first one +uh is a little bit convoluted + + align:start position:0% +uh is a little bit convoluted + + + align:start position:0% +uh is a little bit convoluted +frankly i like it because he's really + + align:start position:0% +frankly i like it because he's really + + + align:start position:0% +frankly i like it because he's really +trying he's really saying what i think + + align:start position:0% +trying he's really saying what i think + + + align:start position:0% +trying he's really saying what i think +he really means and that is he's trying + + align:start position:0% +he really means and that is he's trying + + + align:start position:0% +he really means and that is he's trying +to connect + + align:start position:0% +to connect + + + align:start position:0% +to connect +his categorical imperative + + align:start position:0% +his categorical imperative + + + align:start position:0% +his categorical imperative +to first principles of logic + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +that's important to you + + align:start position:0% +that's important to you + + + align:start position:0% +that's important to you +um + + align:start position:0% +um + + + align:start position:0% +um +that's that i think the main importance + + align:start position:0% +that's that i think the main importance + + + align:start position:0% +that's that i think the main importance +of that to you + + align:start position:0% +of that to you + + + align:start position:0% +of that to you +is that now you can see what counts + + align:start position:0% +is that now you can see what counts + + + align:start position:0% +is that now you can see what counts +as a + + align:start position:0% +as a + + + align:start position:0% +as a +fundamental idea + + align:start position:0% +fundamental idea + + + align:start position:0% +fundamental idea +as opposed to a theory that's + + align:start position:0% +as opposed to a theory that's + + + align:start position:0% +as opposed to a theory that's +incremental + + align:start position:0% +incremental + + + align:start position:0% +incremental +uh you can now say that well now now i + + align:start position:0% +uh you can now say that well now now i + + + align:start position:0% +uh you can now say that well now now i +know what the nobel if there was a nobel + + align:start position:0% +know what the nobel if there was a nobel + + + align:start position:0% +know what the nobel if there was a nobel +prize for + + align:start position:0% +prize for + + + align:start position:0% +prize for +philosophy which there isn't + + align:start position:0% +philosophy which there isn't + + + align:start position:0% +philosophy which there isn't +even though philosophers have got nobel + + align:start position:0% +even though philosophers have got nobel + + + align:start position:0% +even though philosophers have got nobel +prizes + + align:start position:0% + + + + align:start position:0% + +for what for peace uh i think maybe + + align:start position:0% +for what for peace uh i think maybe + + + align:start position:0% +for what for peace uh i think maybe +you can count uh uh some of them all of + + align:start position:0% +you can count uh uh some of them all of + + + align:start position:0% +you can count uh uh some of them all of +them all of them who got it for peace + + align:start position:0% +them all of them who got it for peace + + + align:start position:0% +them all of them who got it for peace +were philosophers or doing philosophy + + align:start position:0% +were philosophers or doing philosophy + + + align:start position:0% +were philosophers or doing philosophy +even + + align:start position:0% +even + + + align:start position:0% +even +um + + align:start position:0% +um + + + align:start position:0% +um +some of the chemists + + align:start position:0% +some of the chemists + + + align:start position:0% +some of the chemists +who did it + + align:start position:0% +who did it + + + align:start position:0% +who did it +but uh + + align:start position:0% +but uh + + + align:start position:0% +but uh +sartre + + align:start position:0% +sartre + + + align:start position:0% +sartre +jean-paul + + align:start position:0% +jean-paul + + + align:start position:0% +jean-paul +from versace was a philosophy he got it + + align:start position:0% +from versace was a philosophy he got it + + + align:start position:0% +from versace was a philosophy he got it +he got it and some others but they got + + align:start position:0% +he got it and some others but they got + + + align:start position:0% +he got it and some others but they got +it for literature right + + align:start position:0% +it for literature right + + + align:start position:0% +it for literature right +but they were doing philosophy in the + + align:start position:0% +but they were doing philosophy in the + + + align:start position:0% +but they were doing philosophy in the +literature + + align:start position:0% +literature + + + align:start position:0% +literature +and sartre i think is where frenchmen + + align:start position:0% +and sartre i think is where frenchmen + + + align:start position:0% +and sartre i think is where frenchmen +can pronounce it i think i can get away + + align:start position:0% +can pronounce it i think i can get away + + + align:start position:0% +can pronounce it i think i can get away +with saying a song + + align:start position:0% +with saying a song + + + align:start position:0% +with saying a song +uh is uh someone that i would like to + + align:start position:0% +uh is uh someone that i would like to + + + align:start position:0% +uh is uh someone that i would like to +cover + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +um + + align:start position:0% +um + + + align:start position:0% +um +and uh we can read + + align:start position:0% +and uh we can read + + + align:start position:0% +and uh we can read +the good thing about doing sarc is that + + align:start position:0% +the good thing about doing sarc is that + + + align:start position:0% +the good thing about doing sarc is that +um + + align:start position:0% +um + + + align:start position:0% +um +his plays you can read these plays + + align:start position:0% +his plays you can read these plays + + + align:start position:0% +his plays you can read these plays +overnight they're real short + + align:start position:0% +overnight they're real short + + + align:start position:0% +overnight they're real short +and we can talk about one or two of them + + align:start position:0% + + + + align:start position:0% + +but he is + + align:start position:0% +but he is + + + align:start position:0% +but he is +started is a frenchman he's in a + + align:start position:0% +started is a frenchman he's in a + + + align:start position:0% +started is a frenchman he's in a +different category + + align:start position:0% +different category + + + align:start position:0% +different category +he's going to tell you things just by + + align:start position:0% +he's going to tell you things just by + + + align:start position:0% +he's going to tell you things just by +what i just did he's going to tell a + + align:start position:0% +what i just did he's going to tell a + + + align:start position:0% +what i just did he's going to tell a +story out of that you've got to + + align:start position:0% +story out of that you've got to + + + align:start position:0% +story out of that you've got to +synthesize what the message is + + align:start position:0% +synthesize what the message is + + + align:start position:0% +synthesize what the message is +that's good + + align:start position:0% +that's good + + + align:start position:0% +that's good +um + + align:start position:0% +um + + + align:start position:0% +um +let's see if i can make some more um + + align:start position:0% +let's see if i can make some more um + + + align:start position:0% +let's see if i can make some more um +so there are three ways to look at it + + align:start position:0% +so there are three ways to look at it + + + align:start position:0% +so there are three ways to look at it +if we're doing an analysis + + align:start position:0% +if we're doing an analysis + + + align:start position:0% +if we're doing an analysis +um i know we probably won't have an + + align:start position:0% +um i know we probably won't have an + + + align:start position:0% +um i know we probably won't have an +assignment like we do where we're + + align:start position:0% +assignment like we do where we're + + + align:start position:0% +assignment like we do where we're +specifically told to take this approach + + align:start position:0% +specifically told to take this approach + + + align:start position:0% +specifically told to take this approach +but is it okay just to choose our + + align:start position:0% +but is it okay just to choose our + + + align:start position:0% +but is it okay just to choose our +favorite and pick one and in theory + + align:start position:0% +favorite and pick one and in theory + + + align:start position:0% +favorite and pick one and in theory +should they all come to the same + + align:start position:0% +should they all come to the same + + + align:start position:0% +should they all come to the same +conclusion + + align:start position:0% +conclusion + + + align:start position:0% +conclusion +there's no reason that they should all + + align:start position:0% +there's no reason that they should all + + + align:start position:0% +there's no reason that they should all +come to the same conclusion okay so we + + align:start position:0% +come to the same conclusion okay so we + + + align:start position:0% +come to the same conclusion okay so we +could phrase it in a different way + + align:start position:0% +could phrase it in a different way + + + align:start position:0% +could phrase it in a different way +and come up with something completely + + align:start position:0% +and come up with something completely + + + align:start position:0% +and come up with something completely +different depending on which + + align:start position:0% +different depending on which + + + align:start position:0% +different depending on which +interpretation we'd like our jews to use + + align:start position:0% +interpretation we'd like our jews to use + + + align:start position:0% +interpretation we'd like our jews to use +or think is most appropriate what i hope + + align:start position:0% +or think is most appropriate what i hope + + + align:start position:0% +or think is most appropriate what i hope +is that you have enough experiences in + + align:start position:0% +is that you have enough experiences in + + + align:start position:0% +is that you have enough experiences in +this class that you will find + + align:start position:0% +this class that you will find + + + align:start position:0% +this class that you will find +that you can come up uh with two + + align:start position:0% +that you can come up uh with two + + + align:start position:0% +that you can come up uh with two +opposites even inclusions uh that are + + align:start position:0% +opposites even inclusions uh that are + + + align:start position:0% +opposites even inclusions uh that are +well grounded + + align:start position:0% +well grounded + + + align:start position:0% +well grounded +so and we should write about both of + + align:start position:0% +so and we should write about both of + + + align:start position:0% +so and we should write about both of +them and + + align:start position:0% +them and + + + align:start position:0% +them and +have the same defensibility for both of + + align:start position:0% +have the same defensibility for both of + + + align:start position:0% +have the same defensibility for both of +them okay you're putting me in + + align:start position:0% +them okay you're putting me in + + + align:start position:0% +them okay you're putting me in +my question is + + align:start position:0% +my question is + + + align:start position:0% +my question is +you know because you talked about + + align:start position:0% +you know because you talked about + + + align:start position:0% +you know because you talked about +wanting to have the passion behind the + + align:start position:0% +wanting to have the passion behind the + + + align:start position:0% +wanting to have the passion behind the +argue the conclusion yeah + + align:start position:0% +argue the conclusion yeah + + + align:start position:0% +argue the conclusion yeah +should we + + align:start position:0% +should we + + + align:start position:0% +should we +does that mean we should only write + + align:start position:0% +does that mean we should only write + + + align:start position:0% +does that mean we should only write +about + + align:start position:0% +about + + + align:start position:0% +about +the approach that gives us that passion + + align:start position:0% +the approach that gives us that passion + + + align:start position:0% +the approach that gives us that passion +no guys this thing takes time okay + + align:start position:0% +no guys this thing takes time okay + + + align:start position:0% +no guys this thing takes time okay +okay it takes time this is going to be + + align:start position:0% +okay it takes time this is going to be + + + align:start position:0% +okay it takes time this is going to be +an assignment that i'm going to make + + align:start position:0% +an assignment that i'm going to make + + + align:start position:0% +an assignment that i'm going to make +before the class is over + + align:start position:0% +before the class is over + + + align:start position:0% +before the class is over +uh + + align:start position:0% +uh + + + align:start position:0% +uh +and + + align:start position:0% +and + + + align:start position:0% +and +uh the most important thing um not the + + align:start position:0% +uh the most important thing um not the + + + align:start position:0% +uh the most important thing um not the +most important thing but what i'm going + + align:start position:0% +most important thing but what i'm going + + + align:start position:0% +most important thing but what i'm going +to take out of it today + + align:start position:0% +to take out of it today + + + align:start position:0% +to take out of it today +um is something that the office says uh + + align:start position:0% +um is something that the office says uh + + + align:start position:0% +um is something that the office says uh +early on + + align:start position:0% +early on + + + align:start position:0% +early on +um + + align:start position:0% +um + + + align:start position:0% +um +right at the end of his uh + + align:start position:0% +right at the end of his uh + + + align:start position:0% +right at the end of his uh +preface now he calls it forward rather + + align:start position:0% +preface now he calls it forward rather + + + align:start position:0% +preface now he calls it forward rather +damage forward + + align:start position:0% +damage forward + + + align:start position:0% +damage forward +um + + align:start position:0% +um + + + align:start position:0% +um +and + + align:start position:0% +and + + + align:start position:0% +and +this is a wolfram from the ocean box + + align:start position:0% +this is a wolfram from the ocean box + + + align:start position:0% +this is a wolfram from the ocean box +parcel + + align:start position:0% +parcel + + + align:start position:0% +parcel +okay + + align:start position:0% +okay + + + align:start position:0% +okay +um it's part of the ethereum mythology + + align:start position:0% + + + + align:start position:0% + +uh but this is a german + + align:start position:0% +uh but this is a german + + + align:start position:0% +uh but this is a german +uh who's writing it and um + + align:start position:0% +uh who's writing it and um + + + align:start position:0% +uh who's writing it and um +you're you're probably + + align:start position:0% +you're you're probably + + + align:start position:0% +you're you're probably +most familiar with thomas mallory's + + align:start position:0% +most familiar with thomas mallory's + + + align:start position:0% +most familiar with thomas mallory's +what's called mort arthur king arthur's + + align:start position:0% +what's called mort arthur king arthur's + + + align:start position:0% +what's called mort arthur king arthur's +story you know + + align:start position:0% +story you know + + + align:start position:0% +story you know +gwynevere and all of that you're + + align:start position:0% +gwynevere and all of that you're + + + align:start position:0% +gwynevere and all of that you're +probably most familiar with that + + align:start position:0% +probably most familiar with that + + + align:start position:0% +probably most familiar with that +they are pretty much different versions + + align:start position:0% +they are pretty much different versions + + + align:start position:0% +they are pretty much different versions +of the same story + + align:start position:0% +of the same story + + + align:start position:0% +of the same story +okay + + align:start position:0% +okay + + + align:start position:0% +okay +they're different and you'll find many + + align:start position:0% +they're different and you'll find many + + + align:start position:0% +they're different and you'll find many +of the same characters + + align:start position:0% +of the same characters + + + align:start position:0% +of the same characters +in in these stories + + align:start position:0% +in in these stories + + + align:start position:0% +in in these stories +uh but what this what these what what + + align:start position:0% +uh but what this what these what what + + + align:start position:0% +uh but what this what these what what +what the uh + + align:start position:0% +what the uh + + + align:start position:0% +what the uh +both the translators + + align:start position:0% +both the translators + + + align:start position:0% +both the translators +of both of the ones that i have this one + + align:start position:0% +of both of the ones that i have this one + + + align:start position:0% +of both of the ones that i have this one +and the one of mort arthur + + align:start position:0% +and the one of mort arthur + + + align:start position:0% +and the one of mort arthur +uh start out by telling you + + align:start position:0% +uh start out by telling you + + + align:start position:0% +uh start out by telling you +that well i could translate this thing + + align:start position:0% +that well i could translate this thing + + + align:start position:0% +that well i could translate this thing +back into + + align:start position:0% +back into + + + align:start position:0% +back into +plain english + + align:start position:0% + + + + align:start position:0% + +but i won't + + align:start position:0% +but i won't + + + align:start position:0% +but i won't +be just a few there + + align:start position:0% +be just a few there + + + align:start position:0% +be just a few there +says because if you just read it in + + align:start position:0% +says because if you just read it in + + + align:start position:0% +says because if you just read it in +the vernacular of the time + + align:start position:0% +the vernacular of the time + + + align:start position:0% +the vernacular of the time +that after why + + align:start position:0% +that after why + + + align:start position:0% +that after why +maybe page 30 + + align:start position:0% +maybe page 30 + + + align:start position:0% +maybe page 30 +maybe page 15. + + align:start position:0% +maybe page 15. + + + align:start position:0% +maybe page 15. +it'll sound right + + align:start position:0% +it'll sound right + + + align:start position:0% +it'll sound right +and you've already had that experience + + align:start position:0% +and you've already had that 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align:start position:0% +let's see many of the comments i have + + + align:start position:0% +let's see many of the comments i have +were pretty much the same um + + align:start position:0% + + + + align:start position:0% + +uh and + + align:start position:0% +uh and + + + align:start position:0% +uh and +[Music] + + align:start position:0% + + + + align:start position:0% + +oh another another issue is uh with the + + align:start position:0% +oh another another issue is uh with the + + + align:start position:0% +oh another another issue is uh with the +utilitarian approach + + align:start position:0% + + + + align:start position:0% + +it's a little bit forgiving in terms of + + align:start position:0% +it's a little bit forgiving in terms of + + + align:start position:0% +it's a little bit forgiving in terms of +your being able to predict consequences + + align:start position:0% +your being able to predict consequences + + + align:start position:0% +your being able to predict consequences +you don't have to be exact in this even + + align:start position:0% +you don't have to be exact in this even + + + align:start position:0% +you don't have to be exact in this even +if you read stuart milner what they're + + align:start position:0% +if you read stuart milner what they're + + + align:start position:0% +if you read stuart milner what they're +saying is your best judgment at the time + + align:start position:0% + + + + align:start position:0% + +so you make your judgment at the time + + align:start position:0% +so you make your judgment at the time + + + align:start position:0% +so you make your judgment at the time +you don't have to take into you know see + + align:start position:0% +you don't have to take into you know see + + + align:start position:0% +you don't have to take into you know see +that's what really + + align:start position:0% +that's what really + + + align:start position:0% +that's what really +comes into account + + align:start position:0% +comes into account + + + align:start position:0% +comes into account +with engineering + + align:start position:0% +with engineering + + + align:start position:0% +with engineering +you're gonna build a bridge + + align:start position:0% +you're gonna build a bridge + + + align:start position:0% +you're gonna build a bridge +you're gonna build that bridge for a + + align:start position:0% +you're gonna build that bridge for a + + + align:start position:0% +you're gonna build that bridge for a +life of a hundred years + + align:start position:0% +life of a hundred years + + + align:start position:0% +life of a hundred years +now you're supposed to exp tell me what + + align:start position:0% +now you're supposed to exp tell me what + + + align:start position:0% +now you're supposed to exp tell me what +the consequences are to everybody who + + align:start position:0% +the consequences are to everybody who + + + align:start position:0% +the consequences are to everybody who +crosses that bridge + + align:start position:0% + + + + align:start position:0% + +you got to make some kind of judgment + + align:start position:0% +you got to make some kind of judgment + + + align:start position:0% +you got to make some kind of judgment +reasonable judgment + + align:start position:0% +reasonable judgment + + + align:start position:0% +reasonable judgment +that + + align:start position:0% +that + + + align:start position:0% +that +is not so much defensible + + align:start position:0% +is not so much defensible + + + align:start position:0% +is not so much defensible +as it is i'm a user term committable + + align:start position:0% +as it is i'm a user term committable + + + align:start position:0% +as it is i'm a user term committable +you think that other people will say + + align:start position:0% +you think that other people will say + + + align:start position:0% +you think that other people will say +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +we'll go along with this + + align:start position:0% +we'll go along with this + + + align:start position:0% +we'll go along with this +and that's why there's a there now when + + align:start position:0% +and that's why there's a there now when + + + align:start position:0% +and that's why there's a there now when +it comes to engineering i'll you won't + + align:start position:0% +it comes to engineering i'll you won't + + + align:start position:0% +it comes to engineering i'll you won't +find this in many of the texts i don't + + align:start position:0% +find this in many of the texts i don't + + + align:start position:0% +find this in many of the texts i don't +think you'll find it in any of them + + align:start position:0% +think you'll find it in any of them + + + align:start position:0% +think you'll find it in any of them +but i'll tell you right now which is one + + align:start position:0% +but i'll tell you right now which is one + + + align:start position:0% +but i'll tell you right now which is one +of the most compelling + + align:start position:0% +of the most compelling + + + align:start position:0% +of the most compelling +uh + + align:start position:0% + + + + align:start position:0% + +rationales an engineer can give for + + align:start position:0% +rationales an engineer can give for + + + align:start position:0% +rationales an engineer can give for +doing x as opposed to y + + align:start position:0% +doing x as opposed to y + + + align:start position:0% +doing x as opposed to y +that works almost if if if it applies + + align:start position:0% +that works almost if if if it applies + + + align:start position:0% +that works almost if if if it applies +works almost all the time + + align:start position:0% + + + + align:start position:0% + +we always do it that way + + align:start position:0% +we always do it that way + + + align:start position:0% +we always do it that way +tradition + + align:start position:0% +tradition + + + align:start position:0% +tradition +okay so you got a citizen group in here + + align:start position:0% +okay so you got a citizen group in here + + + align:start position:0% +okay so you got a citizen group in here +and they want to know why you want to + + align:start position:0% +and they want to know why you want to + + + align:start position:0% +and they want to know why you want to +put the nuclear waste dump over there as + + align:start position:0% +put the nuclear waste dump over there as + + + align:start position:0% +put the nuclear waste dump over there as +opposed to over there + + align:start position:0% +opposed to over there + + + align:start position:0% +opposed to over there +and then you come up with some kind of a + + align:start position:0% +and then you come up with some kind of a + + + align:start position:0% +and then you come up with some kind of a +formula and they don't understand the + + align:start position:0% +formula and they don't understand the + + + align:start position:0% +formula and they don't understand the +formula + + align:start position:0% +formula + + + align:start position:0% +formula +and they're mad about it + + align:start position:0% +and they're mad about it + + + align:start position:0% +and they're mad about it +okay + + align:start position:0% +okay + + + align:start position:0% +okay +if you are able to tell them rightly and + + align:start position:0% +if you are able to tell them rightly and + + + align:start position:0% +if you are able to tell them rightly and +all the other engineers in the room go + + align:start position:0% +all the other engineers in the room go + + + align:start position:0% +all the other engineers in the room go +along with it that that formula is what + + align:start position:0% +along with it that that formula is what + + + align:start position:0% +along with it that that formula is what +we always use + + align:start position:0% + + + + align:start position:0% + +you're going to go a long way with that + + align:start position:0% +you're going to go a long way with that + + + align:start position:0% +you're going to go a long way with that +scientists can't get away with that + + align:start position:0% + + + + align:start position:0% + +there's always the formulas better than + + align:start position:0% +there's always the formulas better than + + + align:start position:0% +there's always the formulas better than +the old ones + + align:start position:0% +the old ones + + + align:start position:0% +the old ones +but engineers tradition is a good one + + align:start position:0% +but engineers tradition is a good one + + + align:start position:0% +but engineers tradition is a good one +and you can use that in ethics + + align:start position:0% + + + + align:start position:0% + +okay uh + + align:start position:0% +okay uh + + + align:start position:0% +okay uh +let's see oh uh lastly um + + align:start position:0% + + + + align:start position:0% + +the um + + align:start position:0% + + + + align:start position:0% + +story terms + + align:start position:0% + + + + align:start position:0% + +uh i'm gonna leave that one to + + align:start position:0% +uh i'm gonna leave that one to + + + align:start position:0% +uh i'm gonna leave that one to +more discussion as we go along the class + + align:start position:0% +more discussion as we go along the class + + + align:start position:0% +more discussion as we go along the class +because i plan to do more of that + + align:start position:0% +because i plan to do more of that + + + align:start position:0% +because i plan to do more of that +so when you do your draft two + + align:start position:0% +so when you do your draft two + + + align:start position:0% +so when you do your draft two +and i'm going to ask you to make draft + + align:start position:0% +and i'm going to ask you to make draft + + + align:start position:0% +and i'm going to ask you to make draft +to a copy + + align:start position:0% +to a copy + + + align:start position:0% +to a copy +of draft one + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% +um + + + align:start position:0% +um +so that you can look back and see your + + align:start position:0% +so that you can look back and see your + + + align:start position:0% +so that you can look back and see your +progress + + align:start position:0% +progress + + + align:start position:0% +progress +don't amend + + align:start position:0% +don't amend + + + align:start position:0% +don't amend +don't edit draft one + + align:start position:0% +don't edit draft one + + + align:start position:0% +don't edit draft one +okay + + align:start position:0% +okay + + + align:start position:0% +okay +um so as time goes along see if you will + + align:start position:0% +um so as time goes along see if you will + + + align:start position:0% +um so as time goes along see if you will +go back and change anything you said + + align:start position:0% +go back and change anything you said + + + align:start position:0% +go back and change anything you said +about the story terms + + align:start position:0% +about the story terms + + + align:start position:0% +about the story terms +okay + + align:start position:0% + + + + align:start position:0% + +okay did i step on anybody's toes + + align:start position:0% + + + + align:start position:0% + +any comments questions + + align:start position:0% +any comments questions + + + align:start position:0% +any comments questions +this was their homework + + align:start position:0% + + + + align:start position:0% + +okay let's do some unfinished well let + + align:start position:0% +okay let's do some unfinished well let + + + align:start position:0% +okay let's do some unfinished well let +me give you more time + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +uh unfinished business and then new + + align:start position:0% +uh unfinished business and then new + + + align:start position:0% +uh unfinished business and then new +business + + align:start position:0% +business + + + align:start position:0% +business +uh better stated since you all uh love + + align:start position:0% + + + + align:start position:0% + +parliamentary + + align:start position:0% + + + + align:start position:0% + +procedures so much + + align:start position:0% + + + + align:start position:0% + +you ever you have experience with + + align:start position:0% +you ever you have experience with + + + align:start position:0% +you ever you have experience with +parliamentary + + align:start position:0% +parliamentary + + + align:start position:0% +parliamentary +bodies + + align:start position:0% + + + + align:start position:0% + +maybe we should do more + + align:start position:0% + + + + align:start position:0% + +i was chair of the faculty senate at + + align:start position:0% +i was chair of the faculty senate at + + + align:start position:0% +i was chair of the faculty senate at +howard for six years now + + align:start position:0% +howard for six years now + + + align:start position:0% +howard for six years now +senates are usually + + align:start position:0% +senates are usually + + + align:start position:0% +senates are usually +if at universities either a senate + + align:start position:0% +if at universities either a senate + + + align:start position:0% +if at universities either a senate +a committee of the faculty that does + + align:start position:0% +a committee of the faculty that does + + + align:start position:0% +a committee of the faculty that does +certain things + + align:start position:0% +certain things + + + align:start position:0% +certain things +and represents the faculty to the + + align:start position:0% +and represents the faculty to the + + + align:start position:0% +and represents the faculty to the +president + + align:start position:0% +president + + + align:start position:0% +president +uh at howard the senate uh + + align:start position:0% +uh at howard the senate uh + + + align:start position:0% +uh at howard the senate uh +is + + align:start position:0% +is + + + align:start position:0% +is +a um + + align:start position:0% +a um + + + align:start position:0% +a um +consists of all of the fact all the + + align:start position:0% +consists of all of the fact all the + + + align:start position:0% +consists of all of the fact all the +full-time faculty + + align:start position:0% +full-time faculty + + + align:start position:0% +full-time faculty +and it also consists of the president + + align:start position:0% +and it also consists of the president + + + align:start position:0% +and it also consists of the president +and the jesus ex-official members + + align:start position:0% +and the jesus ex-official members + + + align:start position:0% +and the jesus ex-official members +without vote + + align:start position:0% + + + + align:start position:0% + +and it the senate all of its committees + + align:start position:0% +and it the senate all of its committees + + + align:start position:0% +and it the senate all of its committees +and all of its meetings are presided + + align:start position:0% +and all of its meetings are presided + + + align:start position:0% +and all of its meetings are presided +over by a faculty person + + align:start position:0% +over by a faculty person + + + align:start position:0% +over by a faculty person +and the senate reports to the board of + + align:start position:0% +and the senate reports to the board of + + + align:start position:0% +and the senate reports to the board of +trustees + + align:start position:0% +trustees + + + align:start position:0% +trustees +through the president + + align:start position:0% +through the president + + + align:start position:0% +through the president +so + + align:start position:0% +so + + + align:start position:0% +so +they give the document to the president + + align:start position:0% +they give the document to the president + + + align:start position:0% +they give the document to the president +and the president is compelled to give + + align:start position:0% +and the president is compelled to give + + + align:start position:0% +and the president is compelled to give +it to the board + + align:start position:0% +it to the board + + + align:start position:0% +it to the board +now the president decide how to give it + + align:start position:0% +now the president decide how to give it + + + align:start position:0% +now the president decide how to give it +to the board + + align:start position:0% +to the board + + + align:start position:0% +to the board +okay but nevertheless that's the way it + + align:start position:0% +okay but nevertheless that's the way it + + + align:start position:0% +okay but nevertheless that's the way it +operates the point i'm trying to make is + + align:start position:0% +operates the point i'm trying to make is + + + align:start position:0% +operates the point i'm trying to make is +that um + + align:start position:0% +that um + + + align:start position:0% +that um +try to imagine an engineer with the + + align:start position:0% +try to imagine an engineer with the + + + align:start position:0% +try to imagine an engineer with the +gavel + + align:start position:0% +gavel + + + align:start position:0% +gavel +parliamentary procedure + + align:start position:0% +parliamentary procedure + + + align:start position:0% +parliamentary procedure +at a university where you got a law + + align:start position:0% +at a university where you got a law + + + align:start position:0% +at a university where you got a law +school + + align:start position:0% + + + + align:start position:0% + +department of business + + align:start position:0% +department of business + + + align:start position:0% +department of business +and i'll tell you the hardest ones to + + align:start position:0% +and i'll tell you the hardest ones to + + + align:start position:0% +and i'll tell you the hardest ones to +present over + + align:start position:0% +present over + + + align:start position:0% +present over +we got a medical school surgeons + + align:start position:0% + + + + align:start position:0% + +every surgeon knows exactly + + align:start position:0% +every surgeon knows exactly + + + align:start position:0% +every surgeon knows exactly +the way he or she + + align:start position:0% +the way he or she + + + align:start position:0% +the way he or she +knows it's got to go + + align:start position:0% +knows it's got to go + + + align:start position:0% +knows it's got to go +and you can't tell + + align:start position:0% +and you can't tell + + + align:start position:0% +and you can't tell +one way + + align:start position:0% +one way + + + align:start position:0% +one way +the the lawyers there's a way to deal + + align:start position:0% +the the lawyers there's a way to deal + + + align:start position:0% +the the lawyers there's a way to deal +with them + + align:start position:0% +with them + + + align:start position:0% +with them +well + + align:start position:0% +well + + + align:start position:0% +well +they they they operate with the law just + + align:start position:0% +they they they operate with the law just + + + align:start position:0% +they they they operate with the law just +a lot like they do with ethics if one + + align:start position:0% +a lot like they do with ethics if one + + + align:start position:0% +a lot like they do with ethics if one +lawyer believes a another one believes b + + align:start position:0% +lawyer believes a another one believes b + + + align:start position:0% +lawyer believes a another one believes b +so when the one is believing a is + + align:start position:0% +so when the one is believing a is + + + align:start position:0% +so when the one is believing a is +tearing you up find one + + align:start position:0% + + + + align:start position:0% + +that will use approach b + + align:start position:0% +that will use approach b + + + align:start position:0% +that will use approach b +right so now you're beginning to see + + align:start position:0% +right so now you're beginning to see + + + align:start position:0% +right so now you're beginning to see +what the connection that i am going to + + align:start position:0% +what the connection that i am going to + + + align:start position:0% +what the connection that i am going to +make that is between law and ethics that + + align:start position:0% +make that is between law and ethics that + + + align:start position:0% +make that is between law and ethics that +there's a whole lot of connection and + + align:start position:0% +there's a whole lot of connection and + + + align:start position:0% +there's a whole lot of connection and +depending on what country you're in + + align:start position:0% + + + + align:start position:0% + +competing uh on what country you're in + + align:start position:0% +competing uh on what country you're in + + + align:start position:0% +competing uh on what country you're in +you may find that there's no difference + + align:start position:0% +you may find that there's no difference + + + align:start position:0% +you may find that there's no difference +between law and entities + + align:start position:0% + + + + align:start position:0% + +you may go to the middle + + align:start position:0% +you may go to the middle + + + align:start position:0% +you may go to the middle +east and the judges + + align:start position:0% +east and the judges + + + align:start position:0% +east and the judges +have on clerical + + align:start position:0% +have on clerical + + + align:start position:0% +have on clerical +uh outfits + + align:start position:0% +uh outfits + + + align:start position:0% +uh outfits +with the koran in front of them + + align:start position:0% +with the koran in front of them + + + align:start position:0% +with the koran in front of them +and they're doing + + align:start position:0% +and they're doing + + + align:start position:0% +and they're doing +they don't see any difference between + + align:start position:0% +they don't see any difference between + + + align:start position:0% +they don't see any difference between +law ethics and religion no difference + + align:start position:0% +law ethics and religion no difference + + + align:start position:0% +law ethics and religion no difference +it's all the same thing + + align:start position:0% +it's all the same thing + + + align:start position:0% +it's all the same thing +okay uh so where was i + + align:start position:0% +okay uh so where was i + + + align:start position:0% +okay uh so where was i +oh we don't want to do old business + + align:start position:0% +oh we don't want to do old business + + + align:start position:0% +oh we don't want to do old business +unfinished business uh what were we + + align:start position:0% +unfinished business uh what were we + + + align:start position:0% +unfinished business uh what were we +doing last i don't think we finished it + + align:start position:0% +doing last i don't think we finished it + + + align:start position:0% +doing last i don't think we finished it +oh + + align:start position:0% + + + + align:start position:0% + +now + + align:start position:0% +now + + + align:start position:0% +now +there's something i think is unfinished + + align:start position:0% +there's something i think is unfinished + + + align:start position:0% +there's something i think is unfinished +about that uh + + align:start position:0% +about that uh + + + align:start position:0% +about that uh +about our discussion on that + + align:start position:0% +about our discussion on that + + + align:start position:0% +about our discussion on that +we talked about ford + + align:start position:0% +we talked about ford + + + align:start position:0% +we talked about ford +but we didn't talk about any persons + + align:start position:0% + + + + align:start position:0% + +now i want to put the question to you + + align:start position:0% +now i want to put the question to you + + + align:start position:0% +now i want to put the question to you +uh first let me put a an observation to + + align:start position:0% +uh first let me put a an observation to + + + align:start position:0% +uh first let me put a an observation to +you + + align:start position:0% +you + + + align:start position:0% +you +that + + align:start position:0% +that + + + align:start position:0% +that +in + + align:start position:0% +in + + + align:start position:0% +in +law + + align:start position:0% +law + + + align:start position:0% +law +a corporation has the status of a person + + align:start position:0% + + + + align:start position:0% + +so that means a corporation can commit a + + align:start position:0% +so that means a corporation can commit a + + + align:start position:0% +so that means a corporation can commit a +crime + + align:start position:0% +crime + + + align:start position:0% +crime +a corporation can be punished for the + + align:start position:0% +a corporation can be punished for the + + + align:start position:0% +a corporation can be punished for the +prime crime + + align:start position:0% +prime crime + + + align:start position:0% +prime crime +even though nobody in the corporation + + align:start position:0% +even though nobody in the corporation + + + align:start position:0% +even though nobody in the corporation +has been found guilty of committing + + align:start position:0% +has been found guilty of committing + + + align:start position:0% +has been found guilty of committing +anyone + + align:start position:0% +anyone + + + align:start position:0% +anyone +okay we agree on that + + align:start position:0% +okay we agree on that + + + align:start position:0% +okay we agree on that +if you find a better sharper statement + + align:start position:0% +if you find a better sharper statement + + + align:start position:0% +if you find a better sharper statement +and bring it in next class and we'll + + align:start position:0% +and bring it in next class and we'll + + + align:start position:0% +and bring it in next class and we'll +amend it what i just said + + align:start position:0% +amend it what i just said + + + align:start position:0% +amend it what i just said +okay uh when engineering ethics was um + + align:start position:0% +okay uh when engineering ethics was um + + + align:start position:0% +okay uh when engineering ethics was um +really invented back in the early early + + align:start position:0% +really invented back in the early early + + + align:start position:0% +really invented back in the early early +70s + + align:start position:0% +70s + + + align:start position:0% +70s +did i give you a history of engineering + + align:start position:0% +did i give you a history of engineering + + + align:start position:0% +did i give you a history of engineering +ethics + + align:start position:0% +ethics + + + align:start position:0% +ethics +or the sts movement yes + + align:start position:0% + + + + align:start position:0% + +there were two great hopes + + align:start position:0% + + + + align:start position:0% + +of the scholars mainly the philosophers + + align:start position:0% +of the scholars mainly the philosophers + + + align:start position:0% +of the scholars mainly the philosophers +in in it + + align:start position:0% + + + + align:start position:0% + +one great hope was that they someone + + align:start position:0% +one great hope was that they someone + + + align:start position:0% +one great hope was that they someone +would be able to discover a new ethic + + align:start position:0% + + + + align:start position:0% + +maybe from a utilitarian + + align:start position:0% +maybe from a utilitarian + + + align:start position:0% +maybe from a utilitarian +variety maybe from + + align:start position:0% +variety maybe from + + + align:start position:0% +variety maybe from +a um + + align:start position:0% +a um + + + align:start position:0% +a um +categorical or + + align:start position:0% +categorical or + + + align:start position:0% +categorical or +deontological variety maybe a new + + align:start position:0% +deontological variety maybe a new + + + align:start position:0% +deontological variety maybe a new +variety but a lot of people thought they + + align:start position:0% +variety but a lot of people thought they + + + align:start position:0% +variety but a lot of people thought they +would be able to find a new ethic i'm + + align:start position:0% +would be able to find a new ethic i'm + + + align:start position:0% +would be able to find a new ethic i'm +not so sure that they did meaning a new + + align:start position:0% +not so sure that they did meaning a new + + + align:start position:0% +not so sure that they did meaning a new +moral + + align:start position:0% +moral + + + align:start position:0% +moral +standard on which to face + + align:start position:0% +standard on which to face + + + align:start position:0% +standard on which to face +decisions yeah + + align:start position:0% + + + + align:start position:0% + +uh + + align:start position:0% +uh + + + align:start position:0% +uh +actually they did i'll tell you about + + align:start position:0% +actually they did i'll tell you about + + + align:start position:0% +actually they did i'll tell you about +one or two two that i think they might + + align:start position:0% +one or two two that i think they might + + + align:start position:0% +one or two two that i think they might +have + + align:start position:0% +have + + + align:start position:0% +have +done or we might have done + + align:start position:0% +done or we might have done + + + align:start position:0% +done or we might have done +um so that was one of the great hopes + + align:start position:0% +um so that was one of the great hopes + + + align:start position:0% +um so that was one of the great hopes +another great hope + + align:start position:0% +another great hope + + + align:start position:0% +another great hope +was to be able to + + align:start position:0% +was to be able to + + + align:start position:0% +was to be able to +give a corporation + + align:start position:0% +give a corporation + + + align:start position:0% +give a corporation +moral agency + + align:start position:0% + + + + align:start position:0% + +that the hope was to be able to say that + + align:start position:0% +that the hope was to be able to say that + + + align:start position:0% +that the hope was to be able to say that +a corporation did the wrong thing + + align:start position:0% + + + + align:start position:0% + +and uh there was this paper that was + + align:start position:0% +and uh there was this paper that was + + + align:start position:0% +and uh there was this paper that was +written + + align:start position:0% + + + + align:start position:0% + +by + + align:start position:0% +by + + + align:start position:0% +by +uh one of the i'll call him out one of + + align:start position:0% +uh one of the i'll call him out one of + + + align:start position:0% +uh one of the i'll call him out one of +the giants in the field his name is john + + align:start position:0% +the giants in the field his name is john + + + align:start position:0% +the giants in the field his name is john +ladd l-a-d-d + + align:start position:0% + + + + align:start position:0% + +john ladd is uh + + align:start position:0% +john ladd is uh + + + align:start position:0% +john ladd is uh +in semi retirement he's uh i guess he's + + align:start position:0% +in semi retirement he's uh i guess he's + + + align:start position:0% +in semi retirement he's uh i guess he's +about 80 now + + align:start position:0% +about 80 now + + + align:start position:0% +about 80 now +but he's still active still writes still + + align:start position:0% +but he's still active still writes still + + + align:start position:0% +but he's still active still writes still +comes to meetings + + align:start position:0% +comes to meetings + + + align:start position:0% +comes to meetings +um john ladd wrote this paper + + align:start position:0% +um john ladd wrote this paper + + + align:start position:0% +um john ladd wrote this paper +and what it said was that there's + + align:start position:0% +and what it said was that there's + + + align:start position:0% +and what it said was that there's +nothing + + align:start position:0% +nothing + + + align:start position:0% +nothing +in + + align:start position:0% +in + + + align:start position:0% +in +uh any moral tradition that would allow + + align:start position:0% +uh any moral tradition that would allow + + + align:start position:0% +uh any moral tradition that would allow +the assignment of moral agency to a + + align:start position:0% +the assignment of moral agency to a + + + align:start position:0% +the assignment of moral agency to a +corporation + + align:start position:0% + + + + align:start position:0% + +as a matter of fact he said there's only + + align:start position:0% +as a matter of fact he said there's only + + + align:start position:0% +as a matter of fact he said there's only +one + + align:start position:0% +one + + + align:start position:0% +one +assignment that you can make + + align:start position:0% +assignment that you can make + + + align:start position:0% +assignment that you can make +to a group as opposed to an individual + + align:start position:0% +to a group as opposed to an individual + + + align:start position:0% +to a group as opposed to an individual +you want to take a wild guess as to what + + align:start position:0% +you want to take a wild guess as to what + + + align:start position:0% +you want to take a wild guess as to what +group that is + + align:start position:0% +group that is + + + align:start position:0% +group that is +a collection of persons that has moral + + align:start position:0% +a collection of persons that has moral + + + align:start position:0% +a collection of persons that has moral +that has a + + align:start position:0% +that has a + + + align:start position:0% +that has a +moral agency a collection as opposed to + + align:start position:0% +moral agency a collection as opposed to + + + align:start position:0% +moral agency a collection as opposed to +an individual + + align:start position:0% + + + + align:start position:0% + +if you make a wild guess you'll probably + + align:start position:0% +if you make a wild guess you'll probably + + + align:start position:0% +if you make a wild guess you'll probably +be right + + align:start position:0% +be right + + + align:start position:0% +be right +a religion + + align:start position:0% +a religion + + + align:start position:0% +a religion +nope + + align:start position:0% + + + + align:start position:0% + +nope + + align:start position:0% +nope + + + align:start position:0% +nope +that's a good one because you would + + align:start position:0% +that's a good one because you would + + + align:start position:0% +that's a good one because you would +think that because of the hierarchical + + align:start position:0% +think that because of the hierarchical + + + align:start position:0% +think that because of the hierarchical +arrangement that no + + align:start position:0% +arrangement that no + + + align:start position:0% +arrangement that no +family + + align:start position:0% + + + + align:start position:0% + +because the kids + + align:start position:0% +because the kids + + + align:start position:0% +because the kids +their parents are responsible for what + + align:start position:0% +their parents are responsible for what + + + align:start position:0% +their parents are responsible for what +morally responsible for the kids moral + + align:start position:0% +morally responsible for the kids moral + + + align:start position:0% +morally responsible for the kids moral +behavior he argued and i don't remember + + align:start position:0% +behavior he argued and i don't remember + + + align:start position:0% +behavior he argued and i don't remember +anybody arguing back on it now this is + + align:start position:0% +anybody arguing back on it now this is + + + align:start position:0% +anybody arguing back on it now this is +john ladd talking + + align:start position:0% +john ladd talking + + + align:start position:0% +john ladd talking +okay + + align:start position:0% +okay + + + align:start position:0% +okay +uh + + align:start position:0% +uh + + + align:start position:0% +uh +if you ever decide to do anything with + + align:start position:0% +if you ever decide to do anything with + + + align:start position:0% +if you ever decide to do anything with +john ladd uh i'll give you a phone + + align:start position:0% +john ladd uh i'll give you a phone + + + align:start position:0% +john ladd uh i'll give you a phone +number + + align:start position:0% +number + + + align:start position:0% +number +i have to look at that but i got it and + + align:start position:0% +i have to look at that but i got it and + + + align:start position:0% +i have to look at that but i got it and +i got his home phone number + + align:start position:0% +i got his home phone number + + + align:start position:0% +i got his home phone number +he'd really like to talk to you + + align:start position:0% +he'd really like to talk to you + + + align:start position:0% +he'd really like to talk to you +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so that pretty much killed it that uh + + align:start position:0% +so that pretty much killed it that uh + + + align:start position:0% +so that pretty much killed it that uh +corporations could not have moral agency + + align:start position:0% +corporations could not have moral agency + + + align:start position:0% +corporations could not have moral agency +now i'm going to talk about a way to + + align:start position:0% +now i'm going to talk about a way to + + + align:start position:0% +now i'm going to talk about a way to +make a corporation have moral agency but + + align:start position:0% +make a corporation have moral agency but + + + align:start position:0% +make a corporation have moral agency but +it's going to be new but i'm going to + + align:start position:0% +it's going to be new but i'm going to + + + align:start position:0% +it's going to be new but i'm going to +put that towards the end of the course + + align:start position:0% +put that towards the end of the course + + + align:start position:0% +put that towards the end of the course +all right + + align:start position:0% +all right + + + align:start position:0% +all right +uh + + align:start position:0% +uh + + + align:start position:0% +uh +so + + align:start position:0% +so + + + align:start position:0% +so +when we talked about the ford pinto case + + align:start position:0% +when we talked about the ford pinto case + + + align:start position:0% +when we talked about the ford pinto case +i remember us talking a lot about ford + + align:start position:0% +i remember us talking a lot about ford + + + align:start position:0% +i remember us talking a lot about ford +and the ford pinto + + align:start position:0% +and the ford pinto + + + align:start position:0% +and the ford pinto +but i don't remember us talking about + + align:start position:0% +but i don't remember us talking about + + + align:start position:0% +but i don't remember us talking about +individuals + + align:start position:0% + + + + align:start position:0% + +were there any individual behaviors in + + align:start position:0% +were there any individual behaviors in + + + align:start position:0% +were there any individual behaviors in +there that we should discuss + + align:start position:0% +there that we should discuss + + + align:start position:0% +there that we should discuss +and then + + align:start position:0% +and then + + + align:start position:0% +and then +characterize that behavior as either + + align:start position:0% +characterize that behavior as either + + + align:start position:0% +characterize that behavior as either +morally moral ethical or unethical + + align:start position:0% +morally moral ethical or unethical + + + align:start position:0% +morally moral ethical or unethical +any difference between moral and morals + + align:start position:0% +any difference between moral and morals + + + align:start position:0% +any difference between moral and morals +and ethics + + align:start position:0% + + + + align:start position:0% + +see that's one thing that uh is typical + + align:start position:0% +see that's one thing that uh is typical + + + align:start position:0% +see that's one thing that uh is typical +of this course + + align:start position:0% +of this course + + + align:start position:0% +of this course +typically you get halfway through the + + align:start position:0% +typically you get halfway through the + + + align:start position:0% +typically you get halfway through the +course before somebody will define what + + align:start position:0% +course before somebody will define what + + + align:start position:0% +course before somebody will define what +the course means + + align:start position:0% + + + + align:start position:0% + +okay that's not unusual at all but but + + align:start position:0% +okay that's not unusual at all but but + + + align:start position:0% +okay that's not unusual at all but but +it's about time for us to get a little + + align:start position:0% +it's about time for us to get a little + + + align:start position:0% +it's about time for us to get a little +sophisticated about + + align:start position:0% +sophisticated about + + + align:start position:0% +sophisticated about +those two words + + align:start position:0% +those two words + + + align:start position:0% +those two words +okay so i'll give you a chance to look + + align:start position:0% +okay so i'll give you a chance to look + + + align:start position:0% +okay so i'll give you a chance to look +them up first and then i'll tell you + + align:start position:0% +them up first and then i'll tell you + + + align:start position:0% +them up first and then i'll tell you +what's going on uh + + align:start position:0% +what's going on uh + + + align:start position:0% +what's going on uh +yeah uh + + align:start position:0% +yeah uh + + + align:start position:0% +yeah uh +are there any individuals that we need + + align:start position:0% +are there any individuals that we need + + + align:start position:0% +are there any individuals that we need +to talk about in this fourth pinto case + + align:start position:0% +to talk about in this fourth pinto case + + + align:start position:0% +to talk about in this fourth pinto case +do they name any or they just talk about + + align:start position:0% +do they name any or they just talk about + + + align:start position:0% +do they name any or they just talk about +engineers + + align:start position:0% +engineers + + + align:start position:0% +engineers +generally + + align:start position:0% + + + + align:start position:0% + +in our little blurb they name one they + + align:start position:0% +in our little blurb they name one they + + + align:start position:0% +in our little blurb they name one they +name + + align:start position:0% +name + + + align:start position:0% +name +echoed the director of automotive safety + + align:start position:0% +echoed the director of automotive safety + + + align:start position:0% +echoed the director of automotive safety +yeah what did they say about it he is + + align:start position:0% +yeah what did they say about it he is + + + align:start position:0% +yeah what did they say about it he is +the one who actually issued the study + + align:start position:0% +the one who actually issued the study + + + align:start position:0% +the one who actually issued the study +with the cost benefit analysis + + align:start position:0% +with the cost benefit analysis + + + align:start position:0% +with the cost benefit analysis +including that + + align:start position:0% +including that + + + align:start position:0% +including that +it was more costly to + + align:start position:0% +it was more costly to + + + align:start position:0% +it was more costly to +add in the safety feature okay + + align:start position:0% + + + + align:start position:0% + +so he's one character yeah i would say + + align:start position:0% +so he's one character yeah i would say + + + align:start position:0% +so he's one character yeah i would say +another one that's not mentioned in the + + align:start position:0% +another one that's not mentioned in the + + + align:start position:0% +another one that's not mentioned in the +article + + align:start position:0% +article + + + align:start position:0% +article +is um + + align:start position:0% +is um + + + align:start position:0% +is um +iacocca right here + + align:start position:0% +iacocca right here + + + align:start position:0% +iacocca right here +who said we need to make a vehicle + + align:start position:0% +who said we need to make a vehicle + + + align:start position:0% +who said we need to make a vehicle +that's less than two thousand dollars + + align:start position:0% +that's less than two thousand dollars + + + align:start position:0% +that's less than two thousand dollars +you gotta do it + + align:start position:0% +you gotta do it + + + align:start position:0% +you gotta do it +okay + + align:start position:0% +okay + + + align:start position:0% +okay +uh lee iacocca + + align:start position:0% +uh lee iacocca + + + align:start position:0% +uh lee iacocca +interestingly enough after that + + align:start position:0% +interestingly enough after that + + + align:start position:0% +interestingly enough after that +i think you all probably know better + + align:start position:0% +i think you all probably know better + + + align:start position:0% +i think you all probably know better +than i became quite a corporate hero in + + align:start position:0% +than i became quite a corporate hero in + + + align:start position:0% +than i became quite a corporate hero in +america + + align:start position:0% + + + + align:start position:0% + +well uh echols + + align:start position:0% +well uh echols + + + align:start position:0% +well uh echols +now what do you think echols would say + + align:start position:0% +now what do you think echols would say + + + align:start position:0% +now what do you think echols would say +if eccles came in here what do you think + + align:start position:0% +if eccles came in here what do you think + + + align:start position:0% +if eccles came in here what do you think +eccles + + align:start position:0% +eccles + + + align:start position:0% +eccles +would say how he would say would he + + align:start position:0% +would say how he would say would he + + + align:start position:0% +would say how he would say would he +defend what he did + + align:start position:0% + + + + align:start position:0% + +and could you defend what he did + + align:start position:0% +and could you defend what he did + + + align:start position:0% +and could you defend what he did +and could you consider uh criticize what + + align:start position:0% +and could you consider uh criticize what + + + align:start position:0% +and could you consider uh criticize what +he did + + align:start position:0% +he did + + + align:start position:0% +he did +and you can play devil's advocate you + + align:start position:0% +and you can play devil's advocate you + + + align:start position:0% +and you can play devil's advocate you +can give me both arguments + + align:start position:0% + + + + align:start position:0% + +so i assume he would defend what he did + + align:start position:0% +so i assume he would defend what he did + + + align:start position:0% +so i assume he would defend what he did +saying + + align:start position:0% +saying + + + align:start position:0% +saying +that it was that cost-benefit analysis + + align:start position:0% +that it was that cost-benefit analysis + + + align:start position:0% +that it was that cost-benefit analysis +which assigns the cost + + align:start position:0% +which assigns the cost + + + align:start position:0% +which assigns the cost +to human life + + align:start position:0% +to human life + + + align:start position:0% +to human life +is legitimate and it's a practice used + + align:start position:0% +is legitimate and it's a practice used + + + align:start position:0% +is legitimate and it's a practice used +is tradition + + align:start position:0% +is tradition + + + align:start position:0% +is tradition +yeah by + + align:start position:0% +yeah by + + + align:start position:0% +yeah by +engineers + + align:start position:0% +engineers + + + align:start position:0% +engineers +and engineering managers in deciding + + align:start position:0% +and engineering managers in deciding + + + align:start position:0% +and engineering managers in deciding +whether a risk is acceptable + + align:start position:0% +whether a risk is acceptable + + + align:start position:0% +whether a risk is acceptable +all right let's play a game suppose i + + align:start position:0% +all right let's play a game suppose i + + + align:start position:0% +all right let's play a game suppose i +have echoes and i hire you not as my + + align:start position:0% +have echoes and i hire you not as my + + + align:start position:0% +have echoes and i hire you not as my +lawyer but as my ethicist + + align:start position:0% +lawyer but as my ethicist + + + align:start position:0% +lawyer but as my ethicist +and i'm going before it before an + + align:start position:0% +and i'm going before it before an + + + align:start position:0% +and i'm going before it before an +ethical review and you've got to present + + align:start position:0% +ethical review and you've got to present + + + align:start position:0% +ethical review and you've got to present +my case + + align:start position:0% +my case + + + align:start position:0% +my case +to y'all + + align:start position:0% +to y'all + + + align:start position:0% +to y'all +uh and you got to ground us + + align:start position:0% +uh and you got to ground us + + + align:start position:0% +uh and you got to ground us +just can't say give me an opinion how + + align:start position:0% +just can't say give me an opinion how + + + align:start position:0% +just can't say give me an opinion how +would you ground it how can we ground it + + align:start position:0% +would you ground it how can we ground it + + + align:start position:0% +would you ground it how can we ground it +in the fact that + + align:start position:0% +in the fact that + + + align:start position:0% +in the fact that +managers that is their responsibility + + align:start position:0% +managers that is their responsibility + + + align:start position:0% +managers that is their responsibility +like i think we discussed this a little + + align:start position:0% +like i think we discussed this a little + + + align:start position:0% +like i think we discussed this a little +bit last time to worry about money as a + + align:start position:0% +bit last time to worry about money as a + + + align:start position:0% +bit last time to worry about money as a +manager + + align:start position:0% +manager + + + align:start position:0% +manager +that's my ethical responsibility + + align:start position:0% +that's my ethical responsibility + + + align:start position:0% +that's my ethical responsibility +to conduct a study that is going to + + align:start position:0% +to conduct a study that is going to + + + align:start position:0% +to conduct a study that is going to +accurately + + align:start position:0% +accurately + + + align:start position:0% +accurately +tell you how this is going to affect the + + align:start position:0% +tell you how this is going to affect the + + + align:start position:0% +tell you how this is going to affect the +company's finances okay so how can you + + align:start position:0% +company's finances okay so how can you + + + align:start position:0% +company's finances okay so how can you +justify what is that your personal + + align:start position:0% +justify what is that your personal + + + align:start position:0% +justify what is that your personal +theory or is there some out some theory + + align:start position:0% +theory or is there some out some theory + + + align:start position:0% +theory or is there some out some theory +out you can reference + + align:start position:0% + + + + align:start position:0% + +well you can probably use something of a + + align:start position:0% +well you can probably use something of a + + + align:start position:0% +well you can probably use something of a +content nature not exactly cons but talk + + align:start position:0% +content nature not exactly cons but talk + + + align:start position:0% +content nature not exactly cons but talk +about a contract do you have an + + align:start position:0% +about a contract do you have an + + + align:start position:0% +about a contract do you have an +obligation that's a principle is there a + + align:start position:0% +obligation that's a principle is there a + + + align:start position:0% +obligation that's a principle is there a +principle that you have to live up your + + align:start position:0% +principle that you have to live up your + + + align:start position:0% +principle that you have to live up your +to your contract right + + align:start position:0% +to your contract right + + + align:start position:0% +to your contract right +that is the contract that i have with + + align:start position:0% +that is the contract that i have with + + + align:start position:0% +that is the contract that i have with +the country with the company when i took + + align:start position:0% +the country with the company when i took + + + align:start position:0% +the country with the company when i took +this job + + align:start position:0% +this job + + + align:start position:0% +this job +um + + align:start position:0% +um + + + align:start position:0% +um +that was the contract i'm worrying about + + align:start position:0% +that was the contract i'm worrying about + + + align:start position:0% +that was the contract i'm worrying about +money bottom line making this thing work + + align:start position:0% +money bottom line making this thing work + + + align:start position:0% +money bottom line making this thing work +and that is my + + align:start position:0% +and that is my + + + align:start position:0% +and that is my +my confidence + + align:start position:0% +my confidence + + + align:start position:0% +my confidence +okay now we have to worry that after + + align:start position:0% +okay now we have to worry that after + + + align:start position:0% +okay now we have to worry that after +you've said that + + align:start position:0% +you've said that + + + align:start position:0% +you've said that +that there's a an opposing point of view + + align:start position:0% +that there's a an opposing point of view + + + align:start position:0% +that there's a an opposing point of view +that's going to give a different answer + + align:start position:0% +that's going to give a different answer + + + align:start position:0% +that's going to give a different answer +[Laughter] + + align:start position:0% +[Laughter] + + + align:start position:0% +[Laughter] +and that the interesting part about that + + align:start position:0% +and that the interesting part about that + + + align:start position:0% +and that the interesting part about that +is that your customers are most likely + + align:start position:0% +is that your customers are most likely + + + align:start position:0% +is that your customers are most likely +going to use your utilitarian because + + align:start position:0% +going to use your utilitarian because + + + align:start position:0% +going to use your utilitarian because +that affects them + + align:start position:0% +that affects them + + + align:start position:0% +that affects them +that's where they're going gonna see it + + align:start position:0% +that's where they're going gonna see it + + + align:start position:0% +that's where they're going gonna see it +um + + align:start position:0% +um + + + align:start position:0% +um +okay so + + align:start position:0% +okay so + + + align:start position:0% +okay so +probably uh echoes or somebody in eccles + + align:start position:0% +probably uh echoes or somebody in eccles + + + align:start position:0% +probably uh echoes or somebody in eccles +position + + align:start position:0% +position + + + align:start position:0% +position +would typically say what you just said + + align:start position:0% +would typically say what you just said + + + align:start position:0% +would typically say what you just said +but would say add something to it we've + + align:start position:0% +but would say add something to it we've + + + align:start position:0% +but would say add something to it we've +already said this in the class + + align:start position:0% +already said this in the class + + + align:start position:0% +already said this in the class +we've already seen it and that is + + align:start position:0% +we've already seen it and that is + + + align:start position:0% +we've already seen it and that is +that the ethical responsibility beyond + + align:start position:0% +that the ethical responsibility beyond + + + align:start position:0% +that the ethical responsibility beyond +that + + align:start position:0% +that + + + align:start position:0% +that +is at a higher level + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +now let me give you something + + align:start position:0% +now let me give you something + + + align:start position:0% +now let me give you something +that will come into play once you say + + align:start position:0% +that will come into play once you say + + + align:start position:0% +that will come into play once you say +that + + align:start position:0% +that + + + align:start position:0% +that +that i've done my job + + align:start position:0% +that i've done my job + + + align:start position:0% +that i've done my job +the utilitarian responsibility + + align:start position:0% +the utilitarian responsibility + + + align:start position:0% +the utilitarian responsibility +is at the higher level + + align:start position:0% + + + + align:start position:0% + +okay let's play that again + + align:start position:0% +okay let's play that again + + + align:start position:0% +okay let's play that again +my job + + align:start position:0% +my job + + + align:start position:0% +my job +is + + align:start position:0% +is + + + align:start position:0% +is +the ontology + + align:start position:0% +the ontology + + + align:start position:0% +the ontology +i have + + align:start position:0% +i have + + + align:start position:0% +i have +a principal + + align:start position:0% +a principal + + + align:start position:0% +a principal +live up to my contracts + + align:start position:0% + + + + align:start position:0% + +i made a deal + + align:start position:0% +i made a deal + + + align:start position:0% +i made a deal +the the contract was legal + + align:start position:0% +the the contract was legal + + + align:start position:0% +the the contract was legal +wait what's the + + align:start position:0% +wait what's the + + + align:start position:0% +wait what's the +what role are you playing now i don't + + align:start position:0% +what role are you playing now i don't + + + align:start position:0% +what role are you playing now i don't +know which world i'm i'm playing eckel's + + align:start position:0% +know which world i'm i'm playing eckel's + + + align:start position:0% +know which world i'm i'm playing eckel's +role okay and + + align:start position:0% +role okay and + + + align:start position:0% +role okay and +then what's the contract + + align:start position:0% +then what's the contract + + + align:start position:0% +then what's the contract +the contract is my job description + + align:start position:0% +the contract is my job description + + + align:start position:0% +the contract is my job description +uh which has legal force because the + + align:start position:0% +uh which has legal force because the + + + align:start position:0% +uh which has legal force because the +corporation + + align:start position:0% +corporation + + + align:start position:0% +corporation +is incorporated that is that it had that + + align:start position:0% +is incorporated that is that it had that + + + align:start position:0% +is incorporated that is that it had that +there is exists a contract between + + align:start position:0% +there is exists a contract between + + + align:start position:0% +there is exists a contract between +the entity and society + + align:start position:0% + + + + align:start position:0% + +so uh you can play that game straight + + align:start position:0% +so uh you can play that game straight + + + align:start position:0% +so uh you can play that game straight +down the line there's a contract between + + align:start position:0% +down the line there's a contract between + + + align:start position:0% +down the line there's a contract between +the entity and society in the articles + + align:start position:0% +the entity and society in the articles + + + align:start position:0% +the entity and society in the articles +of incorporation + + align:start position:0% + + + + align:start position:0% + +and that is a hierarchical + + align:start position:0% +and that is a hierarchical + + + align:start position:0% +and that is a hierarchical +organization + + align:start position:0% +organization + + + align:start position:0% +organization +and my position in the hierarchy has a + + align:start position:0% +and my position in the hierarchy has a + + + align:start position:0% +and my position in the hierarchy has a +name and a responsibility + + align:start position:0% +name and a responsibility + + + align:start position:0% +name and a responsibility +or mission + + align:start position:0% +or mission + + + align:start position:0% +or mission +and + + align:start position:0% +and + + + align:start position:0% +and +to live up to that principle i have to + + align:start position:0% +to live up to that principle i have to + + + align:start position:0% +to live up to that principle i have to +live up to that + + align:start position:0% +live up to that + + + align:start position:0% +live up to that +uh mission + + align:start position:0% + + + + align:start position:0% + +now to break a contract + + align:start position:0% + + + + align:start position:0% + +here's the tip + + align:start position:0% +here's the tip + + + align:start position:0% +here's the tip +now we're we're in the gray area between + + align:start position:0% +now we're we're in the gray area between + + + align:start position:0% +now we're we're in the gray area between +ethics and law + + align:start position:0% +ethics and law + + + align:start position:0% +ethics and law +and if we shift too much to the law area + + align:start position:0% +and if we shift too much to the law area + + + align:start position:0% +and if we shift too much to the law area +you'll know it because i won't know what + + align:start position:0% +you'll know it because i won't know what + + + align:start position:0% +you'll know it because i won't know what +i'm talking about + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +uh but i + + align:start position:0% +uh but i + + + align:start position:0% +uh but i +do know that uh to break a contract both + + align:start position:0% +do know that uh to break a contract both + + + align:start position:0% +do know that uh to break a contract both +parties to the contract have to agree to + + align:start position:0% +parties to the contract have to agree to + + + align:start position:0% +parties to the contract have to agree to +break + + align:start position:0% +break + + + align:start position:0% +break +unless you + + align:start position:0% +unless you + + + align:start position:0% +unless you +break a leg or something like that but + + align:start position:0% +break a leg or something like that but + + + align:start position:0% +break a leg or something like that but +it takes a it takes some agreement + + align:start position:0% +it takes a it takes some agreement + + + align:start position:0% +it takes a it takes some agreement +all right + + align:start position:0% +all right + + + align:start position:0% +all right +so your point is going to your point is + + align:start position:0% +so your point is going to your point is + + + align:start position:0% +so your point is going to your point is +going to be included in what i'm about + + align:start position:0% +going to be included in what i'm about + + + align:start position:0% +going to be included in what i'm about +to say + + align:start position:0% + + + + align:start position:0% + +uh + + align:start position:0% + + + + align:start position:0% + +i don't know if this is in this + + align:start position:0% +i don't know if this is in this + + + align:start position:0% +i don't know if this is in this +particular textbook or not but + + align:start position:0% + + + + align:start position:0% + +it's uh something that's in + + align:start position:0% +it's uh something that's in + + + align:start position:0% +it's uh something that's in +probably um + + align:start position:0% +probably um + + + align:start position:0% +probably um +enough + + align:start position:0% +enough + + + align:start position:0% +enough +engineering ethics textbooks or in + + align:start position:0% +engineering ethics textbooks or in + + + align:start position:0% +engineering ethics textbooks or in +enough + + align:start position:0% +enough + + + align:start position:0% +enough +ethics textbooks + + align:start position:0% +ethics textbooks + + + align:start position:0% +ethics textbooks +or in enough + + align:start position:0% +or in enough + + + align:start position:0% +or in enough +textbooks on science + + align:start position:0% +textbooks on science + + + align:start position:0% +textbooks on science +uh scientific ethics which is mostly + + align:start position:0% +uh scientific ethics which is mostly + + + align:start position:0% +uh scientific ethics which is mostly +research ethics + + align:start position:0% +research ethics + + + align:start position:0% +research ethics +that this is so this is something you + + align:start position:0% +that this is so this is something you + + + align:start position:0% +that this is so this is something you +have to know it's called + + align:start position:0% + + + + align:start position:0% + +the nuremberg principle + + align:start position:0% + + + + align:start position:0% + +anybody want to give a lecture + + align:start position:0% + + + + align:start position:0% + +all right + + align:start position:0% +all right + + + align:start position:0% +all right +nuremberg the nuremberg trials that's + + align:start position:0% +nuremberg the nuremberg trials that's + + + align:start position:0% +nuremberg the nuremberg trials that's +where it comes from + + align:start position:0% + + + + align:start position:0% + +that + + align:start position:0% +that + + + align:start position:0% +that +now this is interesting + + align:start position:0% +now this is interesting + + + align:start position:0% +now this is interesting +try to read some law i try to read law + + align:start position:0% +try to read some law i try to read law + + + align:start position:0% +try to read some law i try to read law +because i have to argue with lawyers at + + align:start position:0% +because i have to argue with lawyers at + + + align:start position:0% +because i have to argue with lawyers at +dinner all the time on weekends + + align:start position:0% + + + + align:start position:0% + +i just found + + align:start position:0% +i just found + + + align:start position:0% +i just found +when my wife and i go out with friends + + align:start position:0% +when my wife and i go out with friends + + + align:start position:0% +when my wife and i go out with friends +a third of them are lawyers and a third + + align:start position:0% +a third of them are lawyers and a third + + + align:start position:0% +a third of them are lawyers and a third +of them are psychiatrists + + align:start position:0% + + + + align:start position:0% + +the other third very + + align:start position:0% +the other third very + + + align:start position:0% +the other third very +but + + align:start position:0% +but + + + align:start position:0% +but +i don't defend myself against the + + align:start position:0% +i don't defend myself against the + + + align:start position:0% +i don't defend myself against the +psychiatrist + + align:start position:0% + + + + align:start position:0% + +and it just was + + align:start position:0% +and it just was + + + align:start position:0% +and it just was +very strange that uh my wife's first + + align:start position:0% +very strange that uh my wife's first + + + align:start position:0% +very strange that uh my wife's first +husband is the second + + align:start position:0% +husband is the second + + + align:start position:0% +husband is the second +but all of these other psychiatrists are + + align:start position:0% +but all of these other psychiatrists are + + + align:start position:0% +but all of these other psychiatrists are +friends that i had before i met him + + align:start position:0% +friends that i had before i met him + + + align:start position:0% +friends that i had before i met him +and i guess they like practicing on me + + align:start position:0% +and i guess they like practicing on me + + + align:start position:0% +and i guess they like practicing on me +second + + align:start position:0% +second + + + align:start position:0% +second +but this that's significant because + + align:start position:0% +but this that's significant because + + + align:start position:0% +but this that's significant because +uh when we talk about the nuremberg + + align:start position:0% +uh when we talk about the nuremberg + + + align:start position:0% +uh when we talk about the nuremberg +principle there's a there's some really + + align:start position:0% +principle there's a there's some really + + + align:start position:0% +principle there's a there's some really +fundamental stuff fundamental stuff in + + align:start position:0% +fundamental stuff fundamental stuff in + + + align:start position:0% +fundamental stuff fundamental stuff in +there about the law + + align:start position:0% +there about the law + + + align:start position:0% +there about the law +that + + align:start position:0% +that + + + align:start position:0% +that +uh is taken directly from ethics so + + align:start position:0% +uh is taken directly from ethics so + + + align:start position:0% +uh is taken directly from ethics so +there's two kinds of there's two kinds + + align:start position:0% +there's two kinds of there's two kinds + + + align:start position:0% +there's two kinds of there's two kinds +of law + + align:start position:0% +of law + + + align:start position:0% +of law +anybody know lawyers hang out with + + align:start position:0% +anybody know lawyers hang out with + + + align:start position:0% +anybody know lawyers hang out with +lawyers + + align:start position:0% +lawyers + + + align:start position:0% +lawyers +okay + + align:start position:0% +okay + + + align:start position:0% +okay + sometimes + + align:start position:0% + sometimes + + + align:start position:0% + sometimes +you get them to talk i mean if you can + + align:start position:0% +you get them to talk i mean if you can + + + align:start position:0% +you get them to talk i mean if you can +stop them from talking but uh + + align:start position:0% +stop them from talking but uh + + + align:start position:0% +stop them from talking but uh +the two kinds of law um + + align:start position:0% + + + + align:start position:0% + +one is called natural law + + align:start position:0% + + + + align:start position:0% + +and the other one is i'm trying to think + + align:start position:0% +and the other one is i'm trying to think + + + align:start position:0% +and the other one is i'm trying to think +of the name it's not exactly scientific + + align:start position:0% +of the name it's not exactly scientific + + + align:start position:0% +of the name it's not exactly scientific +law what's what's the other one + + align:start position:0% + + + + align:start position:0% + +i get these names i wouldn't prepare to + + align:start position:0% +i get these names i wouldn't prepare to + + + align:start position:0% +i get these names i wouldn't prepare to +talk about this today but now that this + + align:start position:0% +talk about this today but now that this + + + align:start position:0% +talk about this today but now that this +come up i'm gonna go through it and then + + align:start position:0% +come up i'm gonna go through it and then + + + align:start position:0% +come up i'm gonna go through it and then +we'll amend it next class or add to it + + align:start position:0% +we'll amend it next class or add to it + + + align:start position:0% +we'll amend it next class or add to it +or whatever we need to but look up the + + align:start position:0% +or whatever we need to but look up the + + + align:start position:0% +or whatever we need to but look up the +other kind + + align:start position:0% +other kind + + + align:start position:0% +other kind +uh uh + + align:start position:0% +uh uh + + + align:start position:0% +uh uh +the the + + align:start position:0% +the the + + + align:start position:0% +the the +natural law basically says that law and + + align:start position:0% +natural law basically says that law and + + + align:start position:0% +natural law basically says that law and +ethics law should never disobey ethical + + align:start position:0% +ethics law should never disobey ethical + + + align:start position:0% +ethics law should never disobey ethical +prisons + + align:start position:0% +prisons + + + align:start position:0% +prisons +should always be + + align:start position:0% +should always be + + + align:start position:0% +should always be +uh + + align:start position:0% +uh + + + align:start position:0% +uh +supported by ethical principles + + align:start position:0% +supported by ethical principles + + + align:start position:0% +supported by ethical principles +uh most most law that's done in the + + align:start position:0% +uh most most law that's done in the + + + align:start position:0% +uh most most law that's done in the +united states is not + + align:start position:0% +united states is not + + + align:start position:0% +united states is not +natural law + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +but both came up in the nuremberg + + align:start position:0% +but both came up in the nuremberg + + + align:start position:0% +but both came up in the nuremberg +principle + + align:start position:0% +principle + + + align:start position:0% +principle +now what happened in the nuremberg + + align:start position:0% +now what happened in the nuremberg + + + align:start position:0% +now what happened in the nuremberg +principle was that the defendants + + align:start position:0% +principle was that the defendants + + + align:start position:0% +principle was that the defendants +uh were nazis + + align:start position:0% + + + + align:start position:0% + +big nazis + + align:start position:0% +big nazis + + + align:start position:0% +big nazis +and + + align:start position:0% +and + + + align:start position:0% +and +their basic defense was + + align:start position:0% +their basic defense was + + + align:start position:0% +their basic defense was +that they were following orders + + align:start position:0% + + + + align:start position:0% + +that in their country + + align:start position:0% +that in their country + + + align:start position:0% +that in their country +they it's almost the same thing we're + + align:start position:0% +they it's almost the same thing we're + + + align:start position:0% +they it's almost the same thing we're +talking about now with the with with + + align:start position:0% +talking about now with the with with + + + align:start position:0% +talking about now with the with with +ford + + align:start position:0% +ford + + + align:start position:0% +ford +that the government + + align:start position:0% +that the government + + + align:start position:0% +that the government +had a + + align:start position:0% +had a + + + align:start position:0% +had a +but a responsibility to the people + + align:start position:0% +but a responsibility to the people + + + align:start position:0% +but a responsibility to the people +and that there was a hierarchy + + align:start position:0% +and that there was a hierarchy + + + align:start position:0% +and that there was a hierarchy +and that if anybody at the top did + + align:start position:0% +and that if anybody at the top did + + + align:start position:0% +and that if anybody at the top did +something that was morally wrong + + align:start position:0% +something that was morally wrong + + + align:start position:0% +something that was morally wrong +then punish him + + align:start position:0% +then punish him + + + align:start position:0% +then punish him +the rest of us were doing what we were + + align:start position:0% +the rest of us were doing what we were + + + align:start position:0% +the rest of us were doing what we were +legally + + align:start position:0% +legally + + + align:start position:0% +legally +required to do + + align:start position:0% + + + + align:start position:0% + +what they said again and what happened + + align:start position:0% +what they said again and what happened + + + align:start position:0% +what they said again and what happened +was in the end what happened was + + align:start position:0% +was in the end what happened was + + + align:start position:0% +was in the end what happened was +that they wound up into + + align:start position:0% + + + + align:start position:0% + +a + + align:start position:0% +a + + + align:start position:0% +a +quantry + + align:start position:0% + + + + align:start position:0% + +because + + align:start position:0% +because + + + align:start position:0% +because +the west + + align:start position:0% +the west + + + align:start position:0% +the west +wanted to + + align:start position:0% +wanted to + + + align:start position:0% +wanted to +say that what they had done + + align:start position:0% + + + + align:start position:0% + +was to commit a crime against humanity + + align:start position:0% +was to commit a crime against humanity + + + align:start position:0% +was to commit a crime against humanity +of which each person in the hierarchy + + align:start position:0% +of which each person in the hierarchy + + + align:start position:0% +of which each person in the hierarchy +was responsible + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +defense + + align:start position:0% + + + + align:start position:0% + +uh + + align:start position:0% +uh + + + align:start position:0% +uh +and + + align:start position:0% +and + + + align:start position:0% +and +not all of the defendants had the same + + align:start position:0% +not all of the defendants had the same + + + align:start position:0% +not all of the defendants had the same +lawyer + + align:start position:0% +lawyer + + + align:start position:0% +lawyer +there was this one lawyer + + align:start position:0% +there was this one lawyer + + + align:start position:0% +there was this one lawyer +as a matter of fact if you see this + + align:start position:0% +as a matter of fact if you see this + + + align:start position:0% +as a matter of fact if you see this +movement this movie called judgment at + + align:start position:0% +movement this movie called judgment at + + + align:start position:0% +movement this movie called judgment at +nuremberg + + align:start position:0% + + + + align:start position:0% + +the lawyer was played + + align:start position:0% +the lawyer was played + + + align:start position:0% +the lawyer was played +by max + + align:start position:0% +by max + + + align:start position:0% +by max +um + + align:start position:0% +um + + + align:start position:0% +um +anybody remember his last name + + align:start position:0% +anybody remember his last name + + + align:start position:0% +anybody remember his last name +lawyer + + align:start position:0% +lawyer + + + align:start position:0% +lawyer +god he got the academy award that year + + align:start position:0% +god he got the academy award that year + + + align:start position:0% +god he got the academy award that year +for best supporting actor okay + + align:start position:0% +for best supporting actor okay + + + align:start position:0% +for best supporting actor okay +the lawyer that said + + align:start position:0% +the lawyer that said + + + align:start position:0% +the lawyer that said +yes + + align:start position:0% + + + + align:start position:0% + +they committed they were not only + + align:start position:0% +they committed they were not only + + + align:start position:0% +they committed they were not only +following their orders but yes they + + align:start position:0% +following their orders but yes they + + + align:start position:0% +following their orders but yes they +committed each one of them a crime + + align:start position:0% +committed each one of them a crime + + + align:start position:0% +committed each one of them a crime +against humanity + + align:start position:0% + + + + align:start position:0% + +then he came up with a brilliant remark + + align:start position:0% +then he came up with a brilliant remark + + + align:start position:0% +then he came up with a brilliant remark +to that + + align:start position:0% + + + + align:start position:0% + +you can't punish a person + + align:start position:0% +you can't punish a person + + + align:start position:0% +you can't punish a person +for breaking a law + + align:start position:0% +for breaking a law + + + align:start position:0% +for breaking a law +that you just made + + align:start position:0% + + + + align:start position:0% + +at the time they did it there was no law + + align:start position:0% +at the time they did it there was no law + + + align:start position:0% +at the time they did it there was no law +called crime against humanity + + align:start position:0% + + + + align:start position:0% + +so what the west finally did was + + align:start position:0% +so what the west finally did was + + + align:start position:0% +so what the west finally did was +they came up with all of these films + + align:start position:0% +they came up with all of these films + + + align:start position:0% +they came up with all of these films +from the concentration camps + + align:start position:0% +from the concentration camps + + + align:start position:0% +from the concentration camps +and used those films + + align:start position:0% +and used those films + + + align:start position:0% +and used those films +pretty much like the oj case + + align:start position:0% +pretty much like the oj case + + + align:start position:0% +pretty much like the oj case +to just bear down on public opinion + + align:start position:0% +to just bear down on public opinion + + + align:start position:0% +to just bear down on public opinion +so that what it what they did in the end + + align:start position:0% +so that what it what they did in the end + + + align:start position:0% +so that what it what they did in the end +they got pretty much support from + + align:start position:0% +they got pretty much support from + + + align:start position:0% +they got pretty much support from +from the rest of the world + + align:start position:0% +from the rest of the world + + + align:start position:0% +from the rest of the world +that's the way that thing came down + + align:start position:0% +that's the way that thing came down + + + align:start position:0% +that's the way that thing came down +it came down + + align:start position:0% + + + + align:start position:0% + +check the spelling on this i had not uh + + align:start position:0% +check the spelling on this i had not uh + + + align:start position:0% +check the spelling on this i had not uh +uh + + align:start position:0% +uh + + + align:start position:0% +uh +prepared for this but it's called me lie + + align:start position:0% +prepared for this but it's called me lie + + + align:start position:0% +prepared for this but it's called me lie +uh it was in vietnam it was a vietnam + + align:start position:0% +uh it was in vietnam it was a vietnam + + + align:start position:0% +uh it was in vietnam it was a vietnam +case + + align:start position:0% +case + + + align:start position:0% +case +where an american where american + + align:start position:0% +where an american where american + + + align:start position:0% +where an american where american +soldiers killed these civilians + + align:start position:0% +soldiers killed these civilians + + + align:start position:0% +soldiers killed these civilians +men women and children + + align:start position:0% +men women and children + + + align:start position:0% +men women and children +and lieutenant cali + + align:start position:0% + + + + align:start position:0% + +said that he + + align:start position:0% +said that he + + + align:start position:0% +said that he +was merely following orders + + align:start position:0% + + + + align:start position:0% + +and what the scholars did i'm not going + + align:start position:0% +and what the scholars did i'm not going + + + align:start position:0% +and what the scholars did i'm not going +to talk about the law anymore + + align:start position:0% +to talk about the law anymore + + + align:start position:0% +to talk about the law anymore +what the scholars did was they came back + + align:start position:0% +what the scholars did was they came back + + + align:start position:0% +what the scholars did was they came back +to the nuremberg principle and said + + align:start position:0% +to the nuremberg principle and said + + + align:start position:0% +to the nuremberg principle and said +that an officer + + align:start position:0% +that an officer + + + align:start position:0% +that an officer +is responsible for what he or she does + + align:start position:0% +is responsible for what he or she does + + + align:start position:0% +is responsible for what he or she does +regardless of the orders + + align:start position:0% +regardless of the orders + + + align:start position:0% +regardless of the orders +the sergeant and the rest of the men + + align:start position:0% +the sergeant and the rest of the men + + + align:start position:0% +the sergeant and the rest of the men +should follow orders + + align:start position:0% +should follow orders + + + align:start position:0% +should follow orders +they divided the house + + align:start position:0% + + + + align:start position:0% + +so now if we apply this thinking to ford + + align:start position:0% +so now if we apply this thinking to ford + + + align:start position:0% +so now if we apply this thinking to ford +what we would tell eccles + + align:start position:0% +what we would tell eccles + + + align:start position:0% +what we would tell eccles +is + + align:start position:0% +is + + + align:start position:0% +is +that + + align:start position:0% +that + + + align:start position:0% +that +being and a professional employee + + align:start position:0% + + + + align:start position:0% + +as opposed to a technical or other kind + + align:start position:0% +as opposed to a technical or other kind + + + align:start position:0% +as opposed to a technical or other kind +of an employee + + align:start position:0% +of an employee + + + align:start position:0% +of an employee +you are responsible for what you do + + align:start position:0% +you are responsible for what you do + + + align:start position:0% +you are responsible for what you do +orders notwithstanding + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +all right so now what i'm going to do is + + align:start position:0% +all right so now what i'm going to do is + + + align:start position:0% +all right so now what i'm going to do is +i just thought rather than + + align:start position:0% +i just thought rather than + + + align:start position:0% +i just thought rather than +all of us just uh saying we'll revisit + + align:start position:0% +all of us just uh saying we'll revisit + + + align:start position:0% +all of us just uh saying we'll revisit +this the next time um + + align:start position:0% + + + + align:start position:0% + +i'm going to + + align:start position:0% +i'm going to + + + align:start position:0% +i'm going to +make a a lighthearted assignment and + + align:start position:0% +make a a lighthearted assignment and + + + align:start position:0% +make a a lighthearted assignment and +that is that you become familiar with + + align:start position:0% +that is that you become familiar with + + + align:start position:0% +that is that you become familiar with +the new nuremberg principle + + align:start position:0% +the new nuremberg principle + + + align:start position:0% +the new nuremberg principle +uh the cali case + + align:start position:0% +uh the cali case + + + align:start position:0% +uh the cali case +and see if you can apply it to the fort + + align:start position:0% +and see if you can apply it to the fort + + + align:start position:0% +and see if you can apply it to the fort +pinto case + + align:start position:0% +pinto case + + + align:start position:0% +pinto case +and whatever corrections need to be made + + align:start position:0% +and whatever corrections need to be made + + + align:start position:0% +and whatever corrections need to be made +at the next + + align:start position:0% +at the next + + + align:start position:0% +at the next +class uh on anything that i said in this + + align:start position:0% +class uh on anything that i said in this + + + align:start position:0% +class uh on anything that i said in this +class + + align:start position:0% +class + + + align:start position:0% +class +or that + + align:start position:0% +or that + + + align:start position:0% +or that +or even the following class that will + + align:start position:0% +or even the following class that will + + + align:start position:0% +or even the following class that will +make that that it will be everybody's + + align:start position:0% +make that that it will be everybody's + + + align:start position:0% +make that that it will be everybody's +responsibility to get it right + + align:start position:0% +responsibility to get it right + + + align:start position:0% +responsibility to get it right +okay + + align:start position:0% +okay + + + align:start position:0% +okay +uh but i think that i'm 99 + + align:start position:0% +uh but i think that i'm 99 + + + align:start position:0% +uh but i think that i'm 99 +on all of this + + align:start position:0% + + + + align:start position:0% + +yes + + align:start position:0% +yes + + + align:start position:0% +yes +which one this one + + align:start position:0% +which one this one + + + align:start position:0% +which one this one +this + + align:start position:0% +this + + + align:start position:0% +this +one it's in a lot of movies + + align:start position:0% + + + + align:start position:0% + +what's the name of it + + align:start position:0% +what's the name of it + + + align:start position:0% +what's the name of it +a few good man + + align:start position:0% + + + + align:start position:0% + +yes oh and guantanamo + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +basically + + align:start position:0% + + + + align:start position:0% + +uh there was another one that i didn't + + align:start position:0% +uh there was another one that i didn't + + + align:start position:0% +uh there was another one that i didn't +see + + align:start position:0% +see + + + align:start position:0% +see +uh starring gene hackman + + align:start position:0% +uh starring gene hackman + + + align:start position:0% +uh starring gene hackman +and denzel washington where denzel is + + align:start position:0% +and denzel washington where denzel is + + + align:start position:0% +and denzel washington where denzel is +captain of this nuclear sub + + align:start position:0% +captain of this nuclear sub + + + align:start position:0% +captain of this nuclear sub +and hackman gives him the order to fire + + align:start position:0% + + + + align:start position:0% + +uh i don't know the name of that film + + align:start position:0% + + + + align:start position:0% + +now + + align:start position:0% +now + + + align:start position:0% +now +i um i guess you know i'm susceptible to + + align:start position:0% +i um i guess you know i'm susceptible to + + + align:start position:0% +i um i guess you know i'm susceptible to +talking about films in class + + align:start position:0% +talking about films in class + + + align:start position:0% +talking about films in class +if you see any of these films and you + + align:start position:0% +if you see any of these films and you + + + align:start position:0% +if you see any of these films and you +want to make a five minute report on the + + align:start position:0% +want to make a five minute report on the + + + align:start position:0% +want to make a five minute report on the +film that is legitimate for this class + + align:start position:0% +film that is legitimate for this class + + + align:start position:0% +film that is legitimate for this class +okay + + align:start position:0% +okay + + + align:start position:0% +okay +uh + + align:start position:0% +uh + + + align:start position:0% +uh +that was another one um + + align:start position:0% + + + + align:start position:0% + +i'll tell you another one that goes + + align:start position:0% +i'll tell you another one that goes + + + align:start position:0% +i'll tell you another one that goes +back a little early for you all + + align:start position:0% + + + + align:start position:0% + +when + + align:start position:0% +when + + + align:start position:0% +when +ronald reagan was president + + align:start position:0% +ronald reagan was president + + + align:start position:0% +ronald reagan was president +there was a + + align:start position:0% +there was a + + + align:start position:0% +there was a +military event + + align:start position:0% +military event + + + align:start position:0% +military event +in the red sea + + align:start position:0% + + + + align:start position:0% + +and reagan came on national television + + align:start position:0% +and reagan came on national television + + + align:start position:0% +and reagan came on national television +and said that + + align:start position:0% +and said that + + + align:start position:0% +and said that +only he as president + + align:start position:0% +only he as president + + + align:start position:0% +only he as president +had the authority + + align:start position:0% +had the authority + + + align:start position:0% +had the authority +to order + + align:start position:0% +to order + + + align:start position:0% +to order +a + + align:start position:0% +a + + + align:start position:0% +a +person a military person in combat to + + align:start position:0% +person a military person in combat to + + + align:start position:0% +person a military person in combat to +use + + align:start position:0% +use + + + align:start position:0% +use +nuclear weapons + + align:start position:0% +nuclear weapons + + + align:start position:0% +nuclear weapons +but he was delegating his authority + + align:start position:0% +but he was delegating his authority + + + align:start position:0% +but he was delegating his authority +authority in the red sea + + align:start position:0% +authority in the red sea + + + align:start position:0% +authority in the red sea +to ship captains + + align:start position:0% + + + + align:start position:0% + +now i'll tell you why i remember that so + + align:start position:0% +now i'll tell you why i remember that so + + + align:start position:0% +now i'll tell you why i remember that so +well + + align:start position:0% + + + + align:start position:0% + +because when i saw him come on + + align:start position:0% +because when i saw him come on + + + align:start position:0% +because when i saw him come on +television and say that + + align:start position:0% +television and say that + + + align:start position:0% +television and say that +i was in an airplane that was getting + + align:start position:0% +i was in an airplane that was getting + + + align:start position:0% +i was in an airplane that was getting +ready to land at + + align:start position:0% +ready to land at + + + align:start position:0% +ready to land at +uh + + align:start position:0% +uh + + + align:start position:0% +uh +iran + + align:start position:0% +iran + + + align:start position:0% +iran +which is on in the red honduras + + align:start position:0% + + + + align:start position:0% + +i was on my way to china and we were + + align:start position:0% +i was on my way to china and we were + + + align:start position:0% +i was on my way to china and we were +actually it was dahren that's where i + + align:start position:0% +actually it was dahren that's where i + + + align:start position:0% +actually it was dahren that's where i +was going dahr rains + + align:start position:0% +was going dahr rains + + + align:start position:0% +was going dahr rains +and + + align:start position:0% +and + + + align:start position:0% +and +we were we were just about + + align:start position:0% +we were we were just about + + + align:start position:0% +we were we were just about +20 minutes out + + align:start position:0% +20 minutes out + + + align:start position:0% +20 minutes out +before they said prepare to land and + + align:start position:0% +before they said prepare to land and + + + align:start position:0% +before they said prepare to land and +we're getting laid out looking over + + align:start position:0% +we're getting laid out looking over + + + align:start position:0% +we're getting laid out looking over +there looking at the red sea my goddess + + align:start position:0% +there looking at the red sea my goddess + + + align:start position:0% +there looking at the red sea my goddess +am i gonna be in a nuclear war + + align:start position:0% +am i gonna be in a nuclear war + + + align:start position:0% +am i gonna be in a nuclear war +oh but i remember that um + + align:start position:0% +oh but i remember that um + + + align:start position:0% +oh but i remember that um +so uh yes uh + + align:start position:0% +so uh yes uh + + + align:start position:0% +so uh yes uh +these situations + + align:start position:0% +these situations + + + align:start position:0% +these situations +uh now + + align:start position:0% +uh now + + + align:start position:0% +uh now +i i i i i would like to call them real + + align:start position:0% +i i i i i would like to call them real + + + align:start position:0% +i i i i i would like to call them real +but uh i think that they are real more + + align:start position:0% +but uh i think that they are real more + + + align:start position:0% +but uh i think that they are real more +than realistic + + align:start position:0% + + + + align:start position:0% + +if you can follow my meaning in that + + align:start position:0% +if you can follow my meaning in that + + + align:start position:0% +if you can follow my meaning in that +that um + + align:start position:0% +that um + + + align:start position:0% +that um +what do you do when the delegation of + + align:start position:0% +what do you do when the delegation of + + + align:start position:0% +what do you do when the delegation of +authority + + align:start position:0% +authority + + + align:start position:0% +authority +goes down to ship commanders + + align:start position:0% +goes down to ship commanders + + + align:start position:0% +goes down to ship commanders +for a nuclear war to launch a nuclear + + align:start position:0% +for a nuclear war to launch a nuclear + + + align:start position:0% +for a nuclear war to launch a nuclear +weapon in defense + + align:start position:0% + + + + align:start position:0% + +now you begin to talk about these issues + + align:start position:0% +now you begin to talk about these issues + + + align:start position:0% +now you begin to talk about these issues +somebody is responsible no matter who + + align:start position:0% +somebody is responsible no matter who + + + align:start position:0% +somebody is responsible no matter who +gave them the authority + + align:start position:0% +gave them the authority + + + align:start position:0% +gave them the authority +well uh so um + + align:start position:0% +well uh so um + + + align:start position:0% +well uh so um +okay um + + align:start position:0% + + + + align:start position:0% + +i think i'm happy with this discussion + + align:start position:0% +i think i'm happy with this discussion + + + align:start position:0% +i think i'm happy with this discussion +on the ford pinto + + align:start position:0% + + + + align:start position:0% + +can i bring up one topic + + align:start position:0% +can i bring up one topic + + + align:start position:0% +can i bring up one topic +i'm going to bring up i just thought of + + align:start position:0% +i'm going to bring up i just thought of + + + align:start position:0% +i'm going to bring up i just thought of +another topic i'm going to bring up on + + align:start position:0% +another topic i'm going to bring up on + + + align:start position:0% +another topic i'm going to bring up on +it go ahead actually it's a story + + align:start position:0% +it go ahead actually it's a story + + + align:start position:0% +it go ahead actually it's a story +another time well + + align:start position:0% +another time well + + + align:start position:0% +another time well +so i've been trying to find a way to say + + align:start position:0% +so i've been trying to find a way to say + + + align:start position:0% +so i've been trying to find a way to say +that + + align:start position:0% +that + + + align:start position:0% +that +the + + align:start position:0% +the + + + align:start position:0% +the +actions of ford and producing and + + align:start position:0% +actions of ford and producing and + + + align:start position:0% +actions of ford and producing and +selling the pintos is not morally + + align:start position:0% +selling the pintos is not morally + + + align:start position:0% +selling the pintos is not morally +defensible + + align:start position:0% +defensible + + + align:start position:0% +defensible +and what i came up with was to say that + + align:start position:0% +and what i came up with was to say that + + + align:start position:0% +and what i came up with was to say that +even though + + align:start position:0% +even though + + + align:start position:0% +even though +the utilitarian cost benefit analysis + + align:start position:0% +the utilitarian cost benefit analysis + + + align:start position:0% +the utilitarian cost benefit analysis +said + + align:start position:0% +said + + + align:start position:0% +said +it was + + align:start position:0% +it was + + + align:start position:0% +it was +not worth it to add the safety feature + + align:start position:0% +not worth it to add the safety feature + + + align:start position:0% +not worth it to add the safety feature +and to sell the car what they didn't + + align:start position:0% +and to sell the car what they didn't + + + align:start position:0% +and to sell the car what they didn't +think about was informant was informed + + align:start position:0% +think about was informant was informed + + + align:start position:0% +think about was informant was informed +consent so like they didn't respect the + + align:start position:0% +consent so like they didn't respect the + + + align:start position:0% +consent so like they didn't respect the +moral agency of the public + + align:start position:0% +moral agency of the public + + + align:start position:0% +moral agency of the public +to decide about their best they were + + align:start position:0% +to decide about their best they were + + + align:start position:0% +to decide about their best they were +getting into it is that an appropriate + + align:start position:0% +getting into it is that an appropriate + + + align:start position:0% +getting into it is that an appropriate +issue + + align:start position:0% + + + + align:start position:0% + +that's a good question + + align:start position:0% +that's a good question + + + align:start position:0% +that's a good question +that's a good question + + align:start position:0% +that's a good question + + + align:start position:0% +that's a good question +uh now + + align:start position:0% +uh now + + + align:start position:0% +uh now +informed consent i want y'all to know + + align:start position:0% +informed consent i want y'all to know + + + align:start position:0% +informed consent i want y'all to know +that term + + align:start position:0% +that term + + + align:start position:0% +that term +uh informed consent + + align:start position:0% +uh informed consent + + + align:start position:0% +uh informed consent +uh + + align:start position:0% +uh + + + align:start position:0% +uh +comes out of medical ethics + + align:start position:0% +comes out of medical ethics + + + align:start position:0% +comes out of medical ethics +because now you're talking about + + align:start position:0% +because now you're talking about + + + align:start position:0% +because now you're talking about +your physician + + align:start position:0% + + + + align:start position:0% + +not only getting your consent + + align:start position:0% +not only getting your consent + + + align:start position:0% +not only getting your consent +for some kind of uh + + align:start position:0% +for some kind of uh + + + align:start position:0% +for some kind of uh +uh procedure + + align:start position:0% +uh procedure + + + align:start position:0% +uh procedure +but the physician giving you some + + align:start position:0% +but the physician giving you some + + + align:start position:0% +but the physician giving you some +lessons on what you're doing + + align:start position:0% + + + + align:start position:0% + +now a little bit of u.s history + + align:start position:0% +now a little bit of u.s history + + + align:start position:0% +now a little bit of u.s history +uh when i was a kid + + align:start position:0% + + + + align:start position:0% + +you just did not + + align:start position:0% + + + + align:start position:0% + +you just did not criticize what a doctor + + align:start position:0% +you just did not criticize what a doctor + + + align:start position:0% +you just did not criticize what a doctor +said + + align:start position:0% +said + + + align:start position:0% +said +just totally unheard of it was almost uh + + align:start position:0% +just totally unheard of it was almost uh + + + align:start position:0% +just totally unheard of it was almost uh +bordering on the religious you just did + + align:start position:0% +bordering on the religious you just did + + + align:start position:0% +bordering on the religious you just did +not question your doctor and getting a + + align:start position:0% +not question your doctor and getting a + + + align:start position:0% +not question your doctor and getting a +second opinion would have been + + align:start position:0% +second opinion would have been + + + align:start position:0% +second opinion would have been +would have been unthinkable + + align:start position:0% +would have been unthinkable + + + align:start position:0% +would have been unthinkable +uh during the late 60s + + align:start position:0% +uh during the late 60s + + + align:start position:0% +uh during the late 60s +uh that began to turn around + + align:start position:0% +uh that began to turn around + + + align:start position:0% +uh that began to turn around +uh + + align:start position:0% +uh + + + align:start position:0% +uh +mainly because now uh now that + + align:start position:0% +mainly because now uh now that + + + align:start position:0% +mainly because now uh now that +everything i've said is empirically + + align:start position:0% +everything i've said is empirically + + + align:start position:0% +everything i've said is empirically +testable i doubt if anybody would + + align:start position:0% +testable i doubt if anybody would + + + align:start position:0% +testable i doubt if anybody would +uh + + align:start position:0% +uh + + + align:start position:0% +uh +dispute what i just said + + align:start position:0% +dispute what i just said + + + align:start position:0% +dispute what i just said +now you might get a little dispute but + + align:start position:0% +now you might get a little dispute but + + + align:start position:0% +now you might get a little dispute but +anybody who would dispute what i'm about + + align:start position:0% +anybody who would dispute what i'm about + + + align:start position:0% +anybody who would dispute what i'm about +to say would understand clearly what i'm + + align:start position:0% +to say would understand clearly what i'm + + + align:start position:0% +to say would understand clearly what i'm +saying and why i said it + + align:start position:0% +saying and why i said it + + + align:start position:0% +saying and why i said it +and that is that things began to turn + + align:start position:0% +and that is that things began to turn + + + align:start position:0% +and that is that things began to turn +around + + align:start position:0% +around + + + align:start position:0% +around +uh when the women's movement + + align:start position:0% +uh when the women's movement + + + align:start position:0% +uh when the women's movement +began to give women more + + align:start position:0% + + + + align:start position:0% + +recognition + + align:start position:0% +recognition + + + align:start position:0% +recognition +for their um + + align:start position:0% +for their um + + + align:start position:0% +for their um +for their uh + + align:start position:0% +for their uh + + + align:start position:0% +for their uh +responsibilities and + + align:start position:0% +responsibilities and + + + align:start position:0% +responsibilities and +thoughts and abilities + + align:start position:0% +thoughts and abilities + + + align:start position:0% +thoughts and abilities +which meant that you now have women who + + align:start position:0% +which meant that you now have women who + + + align:start position:0% +which meant that you now have women who +had children and who were reading books + + align:start position:0% +had children and who were reading books + + + align:start position:0% +had children and who were reading books +about how to care for their children + + align:start position:0% +about how to care for their children + + + align:start position:0% +about how to care for their children +they just weren't + + align:start position:0% +they just weren't + + + align:start position:0% +they just weren't +consulting the doctors and if the doctor + + align:start position:0% +consulting the doctors and if the doctor + + + align:start position:0% +consulting the doctors and if the doctor +said something that they didn't believe + + align:start position:0% +said something that they didn't believe + + + align:start position:0% +said something that they didn't believe +they'd consult another one so out of + + align:start position:0% +they'd consult another one so out of + + + align:start position:0% +they'd consult another one so out of +that you get the sts movement + + align:start position:0% +that you get the sts movement + + + align:start position:0% +that you get the sts movement +and medical ethics then began to stop + + align:start position:0% +and medical ethics then began to stop + + + align:start position:0% +and medical ethics then began to stop +start talking about informed consent + + align:start position:0% +start talking about informed consent + + + align:start position:0% +start talking about informed consent +being a moral + + align:start position:0% +being a moral + + + align:start position:0% +being a moral +dimension to the relationship between + + align:start position:0% + + + + align:start position:0% + +physician and patient + + align:start position:0% + + + + align:start position:0% + +now + + align:start position:0% +now + + + align:start position:0% +now +if you apply informed consent to + + align:start position:0% +if you apply informed consent to + + + align:start position:0% +if you apply informed consent to +engineering + + align:start position:0% + + + + align:start position:0% + +uh + + align:start position:0% +uh + + + align:start position:0% +uh +you run into an not a theoretical but an + + align:start position:0% +you run into an not a theoretical but an + + + align:start position:0% +you run into an not a theoretical but an +applications problem + + align:start position:0% +applications problem + + + align:start position:0% +applications problem +that in most cases in utilitarianism + + align:start position:0% +that in most cases in utilitarianism + + + align:start position:0% +that in most cases in utilitarianism +uh + + align:start position:0% +uh + + + align:start position:0% +uh +that um + + align:start position:0% +that um + + + align:start position:0% +that um +you can't find + + align:start position:0% +you can't find + + + align:start position:0% +you can't find +all of the affected parties + + align:start position:0% +all of the affected parties + + + align:start position:0% +all of the affected parties +and informed consent is so easy because + + align:start position:0% +and informed consent is so easy because + + + align:start position:0% +and informed consent is so easy because +it's the it's the patient + + align:start position:0% +it's the it's the patient + + + align:start position:0% +it's the it's the patient +or the patient's mother + + align:start position:0% +or the patient's mother + + + align:start position:0% +or the patient's mother +could be the patient's father too but + + align:start position:0% +could be the patient's father too but + + + align:start position:0% +could be the patient's father too but +you see what i'm saying that we're + + align:start position:0% +you see what i'm saying that we're + + + align:start position:0% +you see what i'm saying that we're +talking about a role in the family they + + align:start position:0% +talking about a role in the family they + + + align:start position:0% +talking about a role in the family they +can play be played by the male 1 + + align:start position:0% +can play be played by the male 1 + + + align:start position:0% +can play be played by the male 1 +all right so uh informed consent then + + align:start position:0% +all right so uh informed consent then + + + align:start position:0% +all right so uh informed consent then +all uh + + align:start position:0% +all uh + + + align:start position:0% +all uh +except for one case but not one case but + + align:start position:0% +except for one case but not one case but + + + align:start position:0% +except for one case but not one case but +one case that i'm going to bring in the + + align:start position:0% +one case that i'm going to bring in the + + + align:start position:0% +one case that i'm going to bring in the +class + + align:start position:0% +class + + + align:start position:0% +class +and i'm going to i'm not going to tell + + align:start position:0% +and i'm going to i'm not going to tell + + + align:start position:0% +and i'm going to i'm not going to tell +you which one it is + + align:start position:0% +you which one it is + + + align:start position:0% +you which one it is +but i'm going to bring one in the class + + align:start position:0% +but i'm going to bring one in the class + + + align:start position:0% +but i'm going to bring one in the class +informed consent in engineering usually + + align:start position:0% +informed consent in engineering usually + + + align:start position:0% +informed consent in engineering usually +gets defused + + align:start position:0% +gets defused + + + align:start position:0% +gets defused +now in this case that you + + align:start position:0% +now in this case that you + + + align:start position:0% +now in this case that you +inform consent + + align:start position:0% +inform consent + + + align:start position:0% +inform consent +um + + align:start position:0% + + + + align:start position:0% + +how would you apply it to the ford pinto + + align:start position:0% +how would you apply it to the ford pinto + + + align:start position:0% +how would you apply it to the ford pinto +kit + + align:start position:0% + + + + align:start position:0% + +well + + align:start position:0% + + + + align:start position:0% + +i mean one + + align:start position:0% +i mean one + + + align:start position:0% +i mean one +option is that one of the engineers who + + align:start position:0% +option is that one of the engineers who + + + align:start position:0% +option is that one of the engineers who +knew of the test results knew that the + + align:start position:0% +knew of the test results knew that the + + + align:start position:0% +knew of the test results knew that the +car would explode + + align:start position:0% +car would explode + + + align:start position:0% +car would explode +hit in a certain way + + align:start position:0% +hit in a certain way + + + align:start position:0% +hit in a certain way +could + + align:start position:0% +could + + + align:start position:0% +could +at least write a memo to + + align:start position:0% +at least write a memo to + + + align:start position:0% +at least write a memo to +an authority that maybe wasn't being + + align:start position:0% +an authority that maybe wasn't being + + + align:start position:0% +an authority that maybe wasn't being +told about + + align:start position:0% +told about + + + align:start position:0% +told about +like a higher manager + + align:start position:0% +like a higher manager + + + align:start position:0% +like a higher manager +and + + align:start position:0% +and + + + align:start position:0% +and +hope that an action would be taken and + + align:start position:0% +hope that an action would be taken and + + + align:start position:0% +hope that an action would be taken and +then if that didn't do anything + + align:start position:0% + + + + align:start position:0% + +you know contact the new a news agency + + align:start position:0% +you know contact the new a news agency + + + align:start position:0% +you know contact the new a news agency +and + + align:start position:0% + + + + align:start position:0% + +all right now um + + align:start position:0% +all right now um + + + align:start position:0% +all right now um +i don't i've never heard that argument + + align:start position:0% +i don't i've never heard that argument + + + align:start position:0% +i don't i've never heard that argument +applied to the fourth pencil + + align:start position:0% +applied to the fourth pencil + + + align:start position:0% +applied to the fourth pencil +but what i'm saying is you're bringing + + align:start position:0% +but what i'm saying is you're bringing + + + align:start position:0% +but what i'm saying is you're bringing +up something that's causing me causing + + align:start position:0% +up something that's causing me causing + + + align:start position:0% +up something that's causing me causing +my my mind to turn around maybe this is + + align:start position:0% +my my mind to turn around maybe this is + + + align:start position:0% +my my mind to turn around maybe this is +a good project + + align:start position:0% +a good project + + + align:start position:0% +a good project +um + + align:start position:0% +um + + + align:start position:0% +um +whether or not there is + + align:start position:0% +whether or not there is + + + align:start position:0% +whether or not there is +some action + + align:start position:0% +some action + + + align:start position:0% +some action +that is short of whistleblower + + align:start position:0% + + + + align:start position:0% + +uh that gets in gets the consent of the + + align:start position:0% +uh that gets in gets the consent of the + + + align:start position:0% +uh that gets in gets the consent of the +affected parties + + align:start position:0% +affected parties + + + align:start position:0% +affected parties +um + + align:start position:0% +um + + + align:start position:0% +um +is appropriate to this case + + align:start position:0% +is appropriate to this case + + + align:start position:0% +is appropriate to this case +and my instincts tell me it is i mean + + align:start position:0% +and my instincts tell me it is i mean + + + align:start position:0% +and my instincts tell me it is i mean +now we have like the consumer reports so + + align:start position:0% +now we have like the consumer reports so + + + align:start position:0% +now we have like the consumer reports so +if a car is produced and really unsafe + + align:start position:0% +if a car is produced and really unsafe + + + align:start position:0% +if a car is produced and really unsafe +that word gets out and when people buy + + align:start position:0% +that word gets out and when people buy + + + align:start position:0% +that word gets out and when people buy +cars they can consult them + + align:start position:0% +cars they can consult them + + + align:start position:0% +cars they can consult them +and see how it is so maybe that's the + + align:start position:0% +and see how it is so maybe that's the + + + align:start position:0% +and see how it is so maybe that's the +correction on something like this why + + align:start position:0% +correction on something like this why + + + align:start position:0% +correction on something like this why +don't you give us some thought + + align:start position:0% +don't you give us some thought + + + align:start position:0% +don't you give us some thought +everybody give us some fun i think this + + align:start position:0% +everybody give us some fun i think this + + + align:start position:0% +everybody give us some fun i think this +requires a little thought i don't know + + align:start position:0% +requires a little thought i don't know + + + align:start position:0% +requires a little thought i don't know +that anybody has thought of that one + + align:start position:0% +that anybody has thought of that one + + + align:start position:0% +that anybody has thought of that one +i've not seen anything on it + + align:start position:0% +i've not seen anything on it + + + align:start position:0% +i've not seen anything on it +um + + align:start position:0% + + + + align:start position:0% + +i do know that let's put it this way + + align:start position:0% +i do know that let's put it this way + + + align:start position:0% +i do know that let's put it this way +there is what you're really bringing up + + align:start position:0% +there is what you're really bringing up + + + align:start position:0% +there is what you're really bringing up +is + + align:start position:0% + + + + align:start position:0% + +you're suggesting that there is a + + align:start position:0% +you're suggesting that there is a + + + align:start position:0% +you're suggesting that there is a +continuum somewhere between + + align:start position:0% +continuum somewhere between + + + align:start position:0% +continuum somewhere between +whistleblowing and what they call public + + align:start position:0% +whistleblowing and what they call public + + + align:start position:0% +whistleblowing and what they call public +understanding of engineering + + align:start position:0% +understanding of engineering + + + align:start position:0% +understanding of engineering +and that's a formal term there's an + + align:start position:0% +and that's a formal term there's an + + + align:start position:0% +and that's a formal term there's an +office at the national academy of + + align:start position:0% +office at the national academy of + + + align:start position:0% +office at the national academy of +engineering called public understanding + + align:start position:0% +engineering called public understanding + + + align:start position:0% +engineering called public understanding +of engineering there's a office at the + + align:start position:0% +of engineering there's a office at the + + + align:start position:0% +of engineering there's a office at the +national academy of sciences called + + align:start position:0% +national academy of sciences called + + + align:start position:0% +national academy of sciences called +public understanding of science + + align:start position:0% +public understanding of science + + + align:start position:0% +public understanding of science +uh and so + + align:start position:0% +uh and so + + + align:start position:0% +uh and so +a person could inform them + + align:start position:0% +a person could inform them + + + align:start position:0% +a person could inform them +you might say + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +uh + + align:start position:0% +uh + + + align:start position:0% +uh +uh which is not i don't know if this is + + align:start position:0% +uh which is not i don't know if this is + + + align:start position:0% +uh which is not i don't know if this is +the same thing as blowing i haven't + + align:start position:0% +the same thing as blowing i haven't + + + align:start position:0% +the same thing as blowing i haven't +given this thought + + align:start position:0% +given this thought + + + align:start position:0% +given this thought +i don't know who has given a thought my + + align:start position:0% +i don't know who has given a thought my + + + align:start position:0% +i don't know who has given a thought my +instincts tell me nobody's giving a + + align:start position:0% +instincts tell me nobody's giving a + + + align:start position:0% +instincts tell me nobody's giving a +thought + + align:start position:0% +thought + + + align:start position:0% +thought +because i would have read it by now + + align:start position:0% +because i would have read it by now + + + align:start position:0% +because i would have read it by now +so give it some fun + + align:start position:0% +so give it some fun + + + align:start position:0% +so give it some fun +and + + align:start position:0% +and + + + align:start position:0% +and +even if you don't come up with a + + align:start position:0% +even if you don't come up with a + + + align:start position:0% +even if you don't come up with a +conclusion uh if you come up with some + + align:start position:0% +conclusion uh if you come up with some + + + align:start position:0% +conclusion uh if you come up with some +more questions or comments as the as the + + align:start position:0% +more questions or comments as the as the + + + align:start position:0% +more questions or comments as the as the +course goes along + + align:start position:0% +course goes along + + + align:start position:0% +course goes along +throw them in + + align:start position:0% +throw them in + + + align:start position:0% +throw them in +okay + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +they passed the 20 mile per hour test + + align:start position:0% +they passed the 20 mile per hour test + + + align:start position:0% +they passed the 20 mile per hour test +but in two years there + + align:start position:0% + + + + align:start position:0% + +that was a federal standard right yeah + + align:start position:0% +that was a federal standard right yeah + + + align:start position:0% +that was a federal standard right yeah +that was not a professional + + align:start position:0% +that was not a professional + + + align:start position:0% +that was not a professional +engineering standard + + align:start position:0% + + + + align:start position:0% + +uh now there are two things i can say on + + align:start position:0% +uh now there are two things i can say on + + + align:start position:0% +uh now there are two things i can say on +it and probably what + + align:start position:0% +it and probably what + + + align:start position:0% +it and probably what +ever you have in mind if you if you have + + align:start position:0% +ever you have in mind if you if you have + + + align:start position:0% +ever you have in mind if you if you have +a thought on this + + align:start position:0% +a thought on this + + + align:start position:0% +a thought on this +put it on the table we'll properly buy + + align:start position:0% +put it on the table we'll properly buy + + + align:start position:0% +put it on the table we'll properly buy +it uh + + align:start position:0% +it uh + + + align:start position:0% +it uh +that well you you're in a case almost + + align:start position:0% +that well you you're in a case almost + + + align:start position:0% +that well you you're in a case almost +like this nuremberg case you know + + align:start position:0% +like this nuremberg case you know + + + align:start position:0% +like this nuremberg case you know +somebody's supposed to somebody guilty + + align:start position:0% +somebody's supposed to somebody guilty + + + align:start position:0% +somebody's supposed to somebody guilty +of a crime before + + align:start position:0% +of a crime before + + + align:start position:0% +of a crime before +the act was made a crime + + align:start position:0% +the act was made a crime + + + align:start position:0% +the act was made a crime +if they performed the act before it was + + align:start position:0% +if they performed the act before it was + + + align:start position:0% +if they performed the act before it was +made + + align:start position:0% +made + + + align:start position:0% +made +that's one + + align:start position:0% +that's one + + + align:start position:0% +that's one +uh + + align:start position:0% +uh + + + align:start position:0% +uh +then there's another one that i want to + + align:start position:0% +then there's another one that i want to + + + align:start position:0% +then there's another one that i want to +bring up in this class i was talking + + align:start position:0% +bring up in this class i was talking + + + align:start position:0% +bring up in this class i was talking +we got to get out of here but i was + + align:start position:0% +we got to get out of here but i was + + + align:start position:0% +we got to get out of here but i was +talking to somebody + + align:start position:0% + + + + align:start position:0% + +let me give you do we have an assignment + + align:start position:0% +let me give you do we have an assignment + + + align:start position:0% +let me give you do we have an assignment +we still have to do the two nuclear + + align:start position:0% +we still have to do the two nuclear + + + align:start position:0% +we still have to do the two nuclear +cases + + align:start position:0% +cases + + + align:start position:0% +cases +so that's your assignment we still have + + align:start position:0% +so that's your assignment we still have + + + align:start position:0% +so that's your assignment we still have +to do + + align:start position:0% +to do + + + align:start position:0% +to do +chernobyl and uh three mile hour + + align:start position:0% +chernobyl and uh three mile hour + + + align:start position:0% +chernobyl and uh three mile hour +okay so that's next time this is + + align:start position:0% +okay so that's next time this is + + + align:start position:0% +okay so that's next time this is +thursday + + align:start position:0% +thursday + + + align:start position:0% +thursday +all right um + + align:start position:0% + + + + align:start position:0% + +ah now let me do that and then let me + + align:start position:0% +ah now let me do that and then let me + + + align:start position:0% +ah now let me do that and then let me +put this if i have time to put this + + align:start position:0% +put this if i have time to put this + + + align:start position:0% +put this if i have time to put this +other issue on the board + + align:start position:0% +other issue on the board + + + align:start position:0% +other issue on the board +okay um + + align:start position:0% +okay um + + + align:start position:0% +okay um +i want everybody to read this book now + + align:start position:0% +i want everybody to read this book now + + + align:start position:0% +i want everybody to read this book now +i'm going to give you a month to do it + + align:start position:0% + + + + align:start position:0% + +um let me see a month a month a month + + align:start position:0% +um let me see a month a month a month + + + align:start position:0% +um let me see a month a month a month +where would a month put us + + align:start position:0% +where would a month put us + + + align:start position:0% +where would a month put us +how about three weeks + + align:start position:0% + + + + align:start position:0% + +because the first 50 pages is going to + + align:start position:0% +because the first 50 pages is going to + + + align:start position:0% +because the first 50 pages is going to +be + + align:start position:0% +be + + + align:start position:0% +be +like reading shakespeare it's going to + + align:start position:0% +like reading shakespeare it's going to + + + align:start position:0% +like reading shakespeare it's going to +be a little laborious that's why i'm + + align:start position:0% +be a little laborious that's why i'm + + + align:start position:0% +be a little laborious that's why i'm +giving you a lot of time + + align:start position:0% +giving you a lot of time + + + align:start position:0% +giving you a lot of time +but after that it rolls right on up + + align:start position:0% +but after that it rolls right on up + + + align:start position:0% +but after that it rolls right on up +right now + + align:start position:0% +right now + + + align:start position:0% +right now +uh + + align:start position:0% +uh + + + align:start position:0% +uh +today is the 9th + + align:start position:0% + + + + align:start position:0% + +what about uh april 1st + + align:start position:0% + + + + align:start position:0% + +april + + align:start position:0% + + + + align:start position:0% + +oh okay why not the first class after + + align:start position:0% +oh okay why not the first class after + + + align:start position:0% +oh okay why not the first class after +spring break + + align:start position:0% + + + + align:start position:0% + +so that april first is saturday so that + + align:start position:0% +so that april first is saturday so that + + + align:start position:0% +so that april first is saturday so that +will be uh + + align:start position:0% +will be uh + + + align:start position:0% +will be uh +april 4th + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +i'm gonna give you i'm gonna give you + + align:start position:0% +i'm gonna give you i'm gonna give you + + + align:start position:0% +i'm gonna give you i'm gonna give you +the uh + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +now + + align:start position:0% + + + + align:start position:0% + +it's important to get the spelling right + + align:start position:0% +it's important to get the spelling right + + + align:start position:0% +it's important to get the spelling right +because + + align:start position:0% +because + + + align:start position:0% +because +there is + + align:start position:0% +there is + + + align:start position:0% +there is +parzival + + align:start position:0% + + + + align:start position:0% + +and it's by + + align:start position:0% + + + + align:start position:0% + +wolf in front eshenbach + + align:start position:0% +wolf in front eshenbach + + + align:start position:0% +wolf in front eshenbach +and i would like for you to get there's + + align:start position:0% +and i would like for you to get there's + + + align:start position:0% +and i would like for you to get there's +more than one uh + + align:start position:0% +more than one uh + + + align:start position:0% +more than one uh +uh + + align:start position:0% +uh + + + align:start position:0% +uh +translation + + align:start position:0% +translation + + + align:start position:0% +translation +and the translations are different + + align:start position:0% +and the translations are different + + + align:start position:0% +and the translations are different +um + + align:start position:0% + + + + align:start position:0% + +but i would like for you to get the one + + align:start position:0% +but i would like for you to get the one + + + align:start position:0% +but i would like for you to get the one +that's uh penguin classic + + align:start position:0% + + + + align:start position:0% + +is one of the penguin classics + + align:start position:0% +is one of the penguin classics + + + align:start position:0% +is one of the penguin classics +and this particular + + align:start position:0% +and this particular + + + align:start position:0% +and this particular +translator is named hatto + + align:start position:0% +translator is named hatto + + + align:start position:0% +translator is named hatto +attao + + align:start position:0% + + + + align:start position:0% + +the main reason for choosing hato is to + + align:start position:0% +the main reason for choosing hato is to + + + align:start position:0% +the main reason for choosing hato is to +choose one so that we have the same one + + align:start position:0% +choose one so that we have the same one + + + align:start position:0% +choose one so that we have the same one +because the because the translations + + align:start position:0% +because the because the translations + + + align:start position:0% +because the because the translations +will vary + + align:start position:0% + + + + align:start position:0% + +okay so get that one and we'll discuss + + align:start position:0% +okay so get that one and we'll discuss + + + align:start position:0% +okay so get that one and we'll discuss +it first class after the spring break + + align:start position:0% +it first class after the spring break + + + align:start position:0% +it first class after the spring break +um + + align:start position:0% +um + + + align:start position:0% +um +don't like i said the first 50 pages + + align:start position:0% +don't like i said the first 50 pages + + + align:start position:0% +don't like i said the first 50 pages +don't be put off + + align:start position:0% +don't be put off + + + align:start position:0% +don't be put off +it's like reading shakespeare the first + + align:start position:0% +it's like reading shakespeare the first + + + align:start position:0% +it's like reading shakespeare the first +time it's a little bit + + align:start position:0% +time it's a little bit + + + align:start position:0% +time it's a little bit +you know + + align:start position:0% +you know + + + align:start position:0% +you know +let me just open a page up man + + align:start position:0% + + + + align:start position:0% + +there was a heathen named + + align:start position:0% +there was a heathen named + + + align:start position:0% +there was a heathen named +flagetman + + align:start position:0% + + + + align:start position:0% + +who was highly renowned for his + + align:start position:0% +who was highly renowned for his + + + align:start position:0% +who was highly renowned for his +requirements + + align:start position:0% +requirements + + + align:start position:0% +requirements +requirements + + align:start position:0% +requirements + + + align:start position:0% +requirements +the same + + align:start position:0% +the same + + + align:start position:0% +the same +physicist + + align:start position:0% +physicist + + + align:start position:0% +physicist +was descended from solomon + + align:start position:0% +was descended from solomon + + + align:start position:0% +was descended from solomon +don't worry about physics you'll get it + + align:start position:0% +don't worry about physics you'll get it + + + align:start position:0% +don't worry about physics you'll get it +okay + + align:start position:0% +okay + + + align:start position:0% +okay +in other words uh don't even look for a + + align:start position:0% +in other words uh don't even look for a + + + align:start position:0% +in other words uh don't even look for a +um + + align:start position:0% +um + + + align:start position:0% +um +for a + + align:start position:0% + + + + align:start position:0% + +for dictionary i mean a you know + + align:start position:0% +for dictionary i mean a you know + + + align:start position:0% +for dictionary i mean a you know +dictionary + + align:start position:0% +dictionary + + + align:start position:0% +dictionary +just read + + align:start position:0% +just read + + + align:start position:0% +just read +this author's forward + + align:start position:0% +this author's forward + + + align:start position:0% +this author's forward +he'll tell you how to get through this + + align:start position:0% +he'll tell you how to get through this + + + align:start position:0% +he'll tell you how to get through this +book + + align:start position:0% +book + + + align:start position:0% +book +and after this it'll knock your socks + + align:start position:0% +and after this it'll knock your socks + + + align:start position:0% +and after this it'll knock your socks +off + + align:start position:0% +off + + + align:start position:0% +off +don't get part + + align:start position:0% +don't get part + + + align:start position:0% +don't get part +if you get personable mixed up with + + align:start position:0% +if you get personable mixed up with + + + align:start position:0% +if you get personable mixed up with +parsifal p-a-r-s-i-f-a-l + + align:start position:0% + + + + align:start position:0% + +it's the same mythical character + + align:start position:0% +it's the same mythical character + + + align:start position:0% +it's the same mythical character +pretty much the same story + + align:start position:0% +pretty much the same story + + + align:start position:0% +pretty much the same story +but different + + align:start position:0% +but different + + + align:start position:0% +but different +very different uh which is part and + + align:start position:0% +very different uh which is part and + + + align:start position:0% +very different uh which is part and +parceval is um + + align:start position:0% +parceval is um + + + align:start position:0% +parceval is um +it's another time to go just about time + + align:start position:0% +it's another time to go just about time + + + align:start position:0% +it's another time to go just about time +ago parseval is + + align:start position:0% +ago parseval is + + + align:start position:0% +ago parseval is +the name of the great um + + align:start position:0% +the name of the great um + + + align:start position:0% +the name of the great um +german opera + + align:start position:0% + + + + align:start position:0% + +and uh + + align:start position:0% +and uh + + + align:start position:0% +and uh +he's one of the characters and lauren + + align:start position:0% +he's one of the characters and lauren + + + align:start position:0% +he's one of the characters and lauren +grin is his son + + align:start position:0% + + + + align:start position:0% + +and uh this that's a whole different + + align:start position:0% +and uh this that's a whole different + + + align:start position:0% +and uh this that's a whole different +uh + + align:start position:0% +uh + + + align:start position:0% +uh +thing + + align:start position:0% +thing + + + align:start position:0% +thing +it's been turned around + + align:start position:0% +it's been turned around + + + align:start position:0% +it's been turned around +then there's percival + + align:start position:0% + + + + align:start position:0% + +same + + align:start position:0% +same + + + align:start position:0% +same +at night + + align:start position:0% +at night + + + align:start position:0% +at night +pretty much you know there's a venn + + align:start position:0% +pretty much you know there's a venn + + + align:start position:0% +pretty much you know there's a venn +diagram there's overlapping stories a + + align:start position:0% +diagram there's overlapping stories a + + + align:start position:0% +diagram there's overlapping stories a +lot in the middle is the same but + + align:start position:0% +lot in the middle is the same but + + + align:start position:0% +lot in the middle is the same but +there's a lot on the edges that are + + align:start position:0% +there's a lot on the edges that are + + + align:start position:0% +there's a lot on the edges that are +different uh percival is the same night + + align:start position:0% +different uh percival is the same night + + + align:start position:0% +different uh percival is the same night +in + + align:start position:0% +in + + + align:start position:0% +in +uh + + align:start position:0% +uh + + + align:start position:0% +uh +king arthur's round tape + + align:start position:0% +king arthur's round tape + + + align:start position:0% +king arthur's round tape +that's partial + + align:start position:0% +that's partial + + + align:start position:0% +that's partial +but the stories tell it + + align:start position:0% +but the stories tell it + + + align:start position:0% +but the stories tell it +a little bit + + align:start position:0% +a little bit + + + align:start position:0% +a little bit +a little bit + + align:start position:0% +a little bit + + + align:start position:0% +a little bit +um + + align:start position:0% +um + + + align:start position:0% +um +but i want you to read that one + + align:start position:0% +but i want you to read that one + + + align:start position:0% +but i want you to read that one +and by the time you finished it you will + + align:start position:0% +and by the time you finished it you will + + + align:start position:0% +and by the time you finished it you will +we will start + + align:start position:0% +we will start + + + align:start position:0% +we will start +and i do have time to do this + + align:start position:0% + + + + align:start position:0% + +that what we have + + align:start position:0% +that what we have + + + align:start position:0% +that what we have +done + + align:start position:0% + + + + align:start position:0% + +so far is that we've looked at um in the + + align:start position:0% +so far is that we've looked at um in the + + + align:start position:0% +so far is that we've looked at um in the +greek tradition + + align:start position:0% + + + + align:start position:0% + +we've looked at + + align:start position:0% + + + + align:start position:0% + +consequentialist approaches + + align:start position:0% +consequentialist approaches + + + align:start position:0% +consequentialist approaches +we've at least one consequence of + + align:start position:0% +we've at least one consequence of + + + align:start position:0% +we've at least one consequence of +approach one non-consequentialist + + align:start position:0% +approach one non-consequentialist + + + align:start position:0% +approach one non-consequentialist +approach or principled approach or + + align:start position:0% +approach or principled approach or + + + align:start position:0% +approach or principled approach or +deontological approach + + align:start position:0% +deontological approach + + + align:start position:0% +deontological approach +uh then we're going to + + align:start position:0% +uh then we're going to + + + align:start position:0% +uh then we're going to +look at + + align:start position:0% +look at + + + align:start position:0% +look at +virtue + + align:start position:0% +virtue + + + align:start position:0% +virtue +ethics and under that we're going to + + align:start position:0% +ethics and under that we're going to + + + align:start position:0% +ethics and under that we're going to +look at + + align:start position:0% + + + + align:start position:0% + +narrative ethics + + align:start position:0% +narrative ethics + + + align:start position:0% +narrative ethics +and then + + align:start position:0% +and then + + + align:start position:0% +and then +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +actually what i'm going to do this gets + + align:start position:0% +actually what i'm going to do this gets + + + align:start position:0% +actually what i'm going to do this gets +a little complicated this narrative + + align:start position:0% +a little complicated this narrative + + + align:start position:0% +a little complicated this narrative +ethics is going to be non-greek + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and then we're going to remember the two + + align:start position:0% +and then we're going to remember the two + + + align:start position:0% +and then we're going to remember the two +paintings + + align:start position:0% +paintings + + + align:start position:0% +paintings +we have the school at athens all of this + + align:start position:0% +we have the school at athens all of this + + + align:start position:0% +we have the school at athens all of this +is in the school of athens + + align:start position:0% +is in the school of athens + + + align:start position:0% +is in the school of athens +except this one this one goes out and + + align:start position:0% +except this one this one goes out and + + + align:start position:0% +except this one this one goes out and +does something else + + align:start position:0% +does something else + + + align:start position:0% +does something else +then we're going to go look at the + + align:start position:0% +then we're going to go look at the + + + align:start position:0% +then we're going to go look at the +painting + + align:start position:0% +painting + + + align:start position:0% +painting +which is the massive bolsina + + align:start position:0% +which is the massive bolsina + + + align:start position:0% +which is the massive bolsina +and we're going to look at roman point + + align:start position:0% +and we're going to look at roman point + + + align:start position:0% +and we're going to look at roman point +of view + + align:start position:0% +of view + + + align:start position:0% +of view +and + + align:start position:0% +and + + + align:start position:0% +and +we're going to look at all of these + + align:start position:0% +we're going to look at all of these + + + align:start position:0% +we're going to look at all of these +cases + + align:start position:0% +cases + + + align:start position:0% +cases +but + + align:start position:0% +but + + + align:start position:0% +but +through the lens + + align:start position:0% +through the lens + + + align:start position:0% +through the lens +of codes + + align:start position:0% +of codes + + + align:start position:0% +of codes +of ethics + + align:start position:0% + + + + align:start position:0% + +we're going to go back to each one of + + align:start position:0% +we're going to go back to each one of + + + align:start position:0% +we're going to go back to each one of +these cases and see what the code has + + align:start position:0% +these cases and see what the code has + + + align:start position:0% +these cases and see what the code has +what a some code has to say about it + + align:start position:0% +what a some code has to say about it + + + align:start position:0% +what a some code has to say about it +so that will be towards the end and i do + + align:start position:0% +so that will be towards the end and i do + + + align:start position:0% +so that will be towards the end and i do +not + + align:start position:0% +not + + + align:start position:0% +not +plan to spend a whole lot of time on + + align:start position:0% +plan to spend a whole lot of time on + + + align:start position:0% +plan to spend a whole lot of time on +this + + align:start position:0% +this + + + align:start position:0% +this +but i plan to spend a whole lot of time + + align:start position:0% +but i plan to spend a whole lot of time + + + align:start position:0% +but i plan to spend a whole lot of time +on this a whole lot of time on this + + align:start position:0% +on this a whole lot of time on this + + + align:start position:0% +on this a whole lot of time on this +not so much on this not so much on that + + align:start position:0% +not so much on this not so much on that + + + align:start position:0% +not so much on this not so much on that +but a whole lot of time on that + + align:start position:0% + + + + align:start position:0% + +and when we start doing the narrative + + align:start position:0% +and when we start doing the narrative + + + align:start position:0% +and when we start doing the narrative +ethics + + align:start position:0% +ethics + + + align:start position:0% +ethics +we will need characters + + align:start position:0% +we will need characters + + + align:start position:0% +we will need characters +from mythology and we'll have at least + + align:start position:0% +from mythology and we'll have at least + + + align:start position:0% +from mythology and we'll have at least +one mythology that we can all anchor + + align:start position:0% +one mythology that we can all anchor + + + align:start position:0% +one mythology that we can all anchor +ourselves on + + align:start position:0% +ourselves on + + + align:start position:0% +ourselves on +and i would like to have some other + + align:start position:0% +and i would like to have some other + + + align:start position:0% +and i would like to have some other +mythologies + + align:start position:0% + + + + align:start position:0% + +and it would be fun for you + + align:start position:0% +and it would be fun for you + + + align:start position:0% +and it would be fun for you +to read some mythologies from some + + align:start position:0% +to read some mythologies from some + + + align:start position:0% +to read some mythologies from some +cultures that + + align:start position:0% +cultures that + + + align:start position:0% +cultures that +you don't know anything about + + align:start position:0% + + + + align:start position:0% + +or if you know something about them + + align:start position:0% +or if you know something about them + + + align:start position:0% +or if you know something about them +let's make sure they're not west + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +well that's it for today thank you \ No newline at end of file diff --git a/0cD-tcITuck.txt b/0cD-tcITuck.txt new file mode 100644 index 0000000000000000000000000000000000000000..b26e94470e3585d95c60bda1f619f7d333be1b34 --- /dev/null +++ b/0cD-tcITuck.txt @@ -0,0 +1,803 @@ +align:start position:0% + +conditional PDFs share most of the + + align:start position:0% +conditional PDFs share most of the + + + align:start position:0% +conditional PDFs share most of the +properties of conditional pmfs all facts + + align:start position:0% +properties of conditional pmfs all facts + + + align:start position:0% +properties of conditional pmfs all facts +for the discrete case have continuous + + align:start position:0% +for the discrete case have continuous + + + align:start position:0% +for the discrete case have continuous +analogs the intuition is more or less + + align:start position:0% +analogs the intuition is more or less + + + align:start position:0% +analogs the intuition is more or less +the same although it is much easier to + + align:start position:0% +the same although it is much easier to + + + align:start position:0% +the same although it is much easier to +grasp in the discrete case for example + + align:start position:0% +grasp in the discrete case for example + + + align:start position:0% +grasp in the discrete case for example +we have seen this version of the total + + align:start position:0% +we have seen this version of the total + + + align:start position:0% +we have seen this version of the total +probability theorem there is a + + align:start position:0% +probability theorem there is a + + + align:start position:0% +probability theorem there is a +continuous analogue in which we replace + + align:start position:0% +continuous analogue in which we replace + + + align:start position:0% +continuous analogue in which we replace +sums by integrals and we replace pmf's + + align:start position:0% +sums by integrals and we replace pmf's + + + align:start position:0% +sums by integrals and we replace pmf's +by pdfs the proof of this fact is + + align:start position:0% +by pdfs the proof of this fact is + + + align:start position:0% +by pdfs the proof of this fact is +actually pretty simple by the + + align:start position:0% +actually pretty simple by the + + + align:start position:0% +actually pretty simple by the +multiplication rule the integrand here + + align:start position:0% +multiplication rule the integrand here + + + align:start position:0% +multiplication rule the integrand here +is just the joint PDF of x and y and we + + align:start position:0% +is just the joint PDF of x and y and we + + + align:start position:0% +is just the joint PDF of x and y and we +know that if we take the joint PDF and + + align:start position:0% +know that if we take the joint PDF and + + + align:start position:0% +know that if we take the joint PDF and +integrate with respect to one variable + + align:start position:0% +integrate with respect to one variable + + + align:start position:0% +integrate with respect to one variable +then we recover the PDF the marginal PDF + + align:start position:0% +then we recover the PDF the marginal PDF + + + align:start position:0% +then we recover the PDF the marginal PDF +of the other random variable so this is + + align:start position:0% +of the other random variable so this is + + + align:start position:0% +of the other random variable so this is +one theorem that extends to the + + align:start position:0% +one theorem that extends to the + + + align:start position:0% +one theorem that extends to the +continuous case moving along we have + + align:start position:0% +continuous case moving along we have + + + align:start position:0% +continuous case moving along we have +defined the conditional expectation in + + align:start position:0% +defined the conditional expectation in + + + align:start position:0% +defined the conditional expectation in +this manner in the discrete case and we + + align:start position:0% +this manner in the discrete case and we + + + align:start position:0% +this manner in the discrete case and we +define it similarly for the continuous + + align:start position:0% +define it similarly for the continuous + + + align:start position:0% +define it similarly for the continuous +case so actually here we now have a new + + align:start position:0% +case so actually here we now have a new + + + align:start position:0% +case so actually here we now have a new +definition this definition is also + + align:start position:0% +definition this definition is also + + + align:start position:0% +definition this definition is also +consistent with the definition of the + + align:start position:0% +consistent with the definition of the + + + align:start position:0% +consistent with the definition of the +expectation of a continuous random + + align:start position:0% +expectation of a continuous random + + + align:start position:0% +expectation of a continuous random +variable the expected value of a + + align:start position:0% +variable the expected value of a + + + align:start position:0% +variable the expected value of a +continuous random variable is the + + align:start position:0% +continuous random variable is the + + + align:start position:0% +continuous random variable is the +integral of x times a density except + + align:start position:0% +integral of x times a density except + + + align:start position:0% +integral of x times a density except +that here we live in a conditional + + align:start position:0% +that here we live in a conditional + + + align:start position:0% +that here we live in a conditional +universe where we're conditioning on + + align:start position:0% +universe where we're conditioning on + + + align:start position:0% +universe where we're conditioning on +this event and therefore we need to use + + align:start position:0% +this event and therefore we need to use + + + align:start position:0% +this event and therefore we need to use +the corresponding conditional PDF + + align:start position:0% +the corresponding conditional PDF + + + align:start position:0% +the corresponding conditional PDF +finally we have the total expectation + + align:start position:0% +finally we have the total expectation + + + align:start position:0% +finally we have the total expectation +theorem in the discrete case and there + + align:start position:0% +theorem in the discrete case and there + + + align:start position:0% +theorem in the discrete case and there +is the obvious analogue in the + + align:start position:0% +is the obvious analogue in the + + + align:start position:0% +is the obvious analogue in the +continuous case where we are using an + + align:start position:0% +continuous case where we are using an + + + align:start position:0% +continuous case where we are using an +integral and a density the + + align:start position:0% +integral and a density the + + + align:start position:0% +integral and a density the +interpretation is that we consider all + + align:start position:0% +interpretation is that we consider all + + + align:start position:0% +interpretation is that we consider all +possibilities for Y under each + + align:start position:0% +possibilities for Y under each + + + align:start position:0% +possibilities for Y under each +possibility of Y we find the expected + + align:start position:0% +possibility of Y we find the expected + + + align:start position:0% +possibility of Y we find the expected +value of x and then we weigh those + + align:start position:0% +value of x and then we weigh those + + + align:start position:0% +value of x and then we weigh those +different possibilities according to the + + align:start position:0% +different possibilities according to the + + + align:start position:0% +different possibilities according to the +corresponding values of the density so + + align:start position:0% +corresponding values of the density so + + + align:start position:0% +corresponding values of the density so +we're taking a weighted average of these + + align:start position:0% +we're taking a weighted average of these + + + align:start position:0% +we're taking a weighted average of these +conditional expectations to obtain the + + align:start position:0% +conditional expectations to obtain the + + + align:start position:0% +conditional expectations to obtain the +overall expectation of the random + + align:start position:0% +overall expectation of the random + + + align:start position:0% +overall expectation of the random +variable X + + align:start position:0% +variable X + + + align:start position:0% +variable X +the derivation of this fact is maybe a + + align:start position:0% +the derivation of this fact is maybe a + + + align:start position:0% +the derivation of this fact is maybe a +little instructive because it uses + + align:start position:0% +little instructive because it uses + + + align:start position:0% +little instructive because it uses +various facts that we have in our hands + + align:start position:0% +various facts that we have in our hands + + + align:start position:0% +various facts that we have in our hands +so let's see how to derive it we start + + align:start position:0% +so let's see how to derive it we start + + + align:start position:0% +so let's see how to derive it we start +from this expression in the right hand + + align:start position:0% +from this expression in the right hand + + + align:start position:0% +from this expression in the right hand +side and we will show that it is equal + + align:start position:0% +side and we will show that it is equal + + + align:start position:0% +side and we will show that it is equal +to the expected value of X the + + align:start position:0% +to the expected value of X the + + + align:start position:0% +to the expected value of X the +expression on the right hand side is + + align:start position:0% +expression on the right hand side is + + + align:start position:0% +expression on the right hand side is +equal to the following it's the integral + + align:start position:0% +equal to the following it's the integral + + + align:start position:0% +equal to the following it's the integral +of the density of Y and then inside here + + align:start position:0% +of the density of Y and then inside here + + + align:start position:0% +of the density of Y and then inside here +we have the conditional expectation + + align:start position:0% +we have the conditional expectation + + + align:start position:0% +we have the conditional expectation +which is defined this way so we just + + align:start position:0% +which is defined this way so we just + + + align:start position:0% +which is defined this way so we just +plug in the definition + + align:start position:0% + + + + align:start position:0% + +and then what we do is we take this term + + align:start position:0% +and then what we do is we take this term + + + align:start position:0% +and then what we do is we take this term +and move it inside the integral which we + + align:start position:0% +and move it inside the integral which we + + + align:start position:0% +and move it inside the integral which we +can do because this integral is with + + align:start position:0% +can do because this integral is with + + + align:start position:0% +can do because this integral is with +respect to X and therefore this is like + + align:start position:0% +respect to X and therefore this is like + + + align:start position:0% +respect to X and therefore this is like +a constant + + align:start position:0% + + + + align:start position:0% + +and we also interchange the order of + + align:start position:0% +and we also interchange the order of + + + align:start position:0% +and we also interchange the order of +integration now the inner integration is + + align:start position:0% +integration now the inner integration is + + + align:start position:0% +integration now the inner integration is +with respect to Y as far as Y is + + align:start position:0% +with respect to Y as far as Y is + + + align:start position:0% +with respect to Y as far as Y is +concerned this term X is a constant so + + align:start position:0% +concerned this term X is a constant so + + + align:start position:0% +concerned this term X is a constant so +we can take it and move it outside this + + align:start position:0% +we can take it and move it outside this + + + align:start position:0% +we can take it and move it outside this +first integral and place it out there so + + align:start position:0% +first integral and place it out there so + + + align:start position:0% +first integral and place it out there so +this term disappears and goes out there + + align:start position:0% +this term disappears and goes out there + + + align:start position:0% +this term disappears and goes out there +what do we have here + + align:start position:0% +what do we have here + + + align:start position:0% +what do we have here +this part by the previous fact the total + + align:start position:0% +this part by the previous fact the total + + + align:start position:0% +this part by the previous fact the total +probability theorem is just the density + + align:start position:0% +probability theorem is just the density + + + align:start position:0% +probability theorem is just the density +of X so we're left with the integral of + + align:start position:0% +of X so we're left with the integral of + + + align:start position:0% +of X so we're left with the integral of +x times the density of X DX and this is + + align:start position:0% +x times the density of X DX and this is + + + align:start position:0% +x times the density of X DX and this is +the expected value of X finally we have + + align:start position:0% +the expected value of X finally we have + + + align:start position:0% +the expected value of X finally we have +various forms of the expected value rule + + align:start position:0% +various forms of the expected value rule + + + align:start position:0% +various forms of the expected value rule +which barely deserve writing down + + align:start position:0% +which barely deserve writing down + + + align:start position:0% +which barely deserve writing down +because they're exactly what you might + + align:start position:0% +because they're exactly what you might + + + align:start position:0% +because they're exactly what you might +expect consider for example an + + align:start position:0% +expect consider for example an + + + align:start position:0% +expect consider for example an +expression such as this one the expected + + align:start position:0% +expression such as this one the expected + + + align:start position:0% +expression such as this one the expected +value of a function of the random + + align:start position:0% +value of a function of the random + + + align:start position:0% +value of a function of the random +variable X but conditioned on the value + + align:start position:0% +variable X but conditioned on the value + + + align:start position:0% +variable X but conditioned on the value +of the random variable Y how do we + + align:start position:0% +of the random variable Y how do we + + + align:start position:0% +of the random variable Y how do we +calculate this quantity + + align:start position:0% +calculate this quantity + + + align:start position:0% +calculate this quantity +well the expected value rule tells us + + align:start position:0% +well the expected value rule tells us + + + align:start position:0% +well the expected value rule tells us +that we should integrate G of x times + + align:start position:0% +that we should integrate G of x times + + + align:start position:0% +that we should integrate G of x times +the density of X but because here we + + align:start position:0% +the density of X but because here we + + + align:start position:0% +the density of X but because here we +live in a conditional universe we should + + align:start position:0% +live in a conditional universe we should + + + align:start position:0% +live in a conditional universe we should +actually use the corresponding + + align:start position:0% +actually use the corresponding + + + align:start position:0% +actually use the corresponding +conditional PDF of X and there are many + + align:start position:0% +conditional PDF of X and there are many + + + align:start position:0% +conditional PDF of X and there are many +other versions of the expected value + + align:start position:0% +other versions of the expected value + + + align:start position:0% +other versions of the expected value +rule any version that we have seen for + + align:start position:0% +rule any version that we have seen for + + + align:start position:0% +rule any version that we have seen for +the discrete case has also a continuous + + align:start position:0% +the discrete case has also a continuous + + + align:start position:0% +the discrete case has also a continuous +analogue which looks about the same + + align:start position:0% +analogue which looks about the same + + + align:start position:0% +analogue which looks about the same +except that we integrate and that we use + + align:start position:0% +except that we integrate and that we use + + + align:start position:0% +except that we integrate and that we use +densities \ No newline at end of file diff --git a/0jljZRnHwOI.txt b/0jljZRnHwOI.txt new file mode 100644 index 0000000000000000000000000000000000000000..a77875a5b948f6a48da0dc32f94b2b3dae730d46 --- /dev/null +++ b/0jljZRnHwOI.txt @@ -0,0 +1,8027 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit MIT opencourseware + + align:start position:0% +of MIT courses visit MIT opencourseware + + + align:start position:0% +of MIT courses visit MIT opencourseware +at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu + + align:start position:0% +ocw.mit.edu + + + align:start position:0% +ocw.mit.edu +all + + align:start position:0% +all + + + align:start position:0% +all +right let's get started everyone so good + + align:start position:0% +right let's get started everyone so good + + + align:start position:0% +right let's get started everyone so good +afternoon welcome to the second lecture + + align:start position:0% +afternoon welcome to the second lecture + + + align:start position:0% +afternoon welcome to the second lecture +of 601 and also of 600 so as always if + + align:start position:0% +of 601 and also of 600 so as always if + + + align:start position:0% +of 601 and also of 600 so as always if +you'd like to follow along with the + + align:start position:0% +you'd like to follow along with the + + + align:start position:0% +you'd like to follow along with the +lecture with the lectures please go + + align:start position:0% +lecture with the lectures please go + + + align:start position:0% +lecture with the lectures please go +ahead and download the slides and the + + align:start position:0% +ahead and download the slides and the + + + align:start position:0% +ahead and download the slides and the +code that um that I'll provide uh at + + align:start position:0% +code that um that I'll provide uh at + + + align:start position:0% +code that um that I'll provide uh at +least an hour before class every day all + + align:start position:0% +least an hour before class every day all + + + align:start position:0% +least an hour before class every day all +right so quick recap of what we did last + + align:start position:0% +right so quick recap of what we did last + + + align:start position:0% +right so quick recap of what we did last +time so last time we talked a little bit + + align:start position:0% +time so last time we talked a little bit + + + align:start position:0% +time so last time we talked a little bit +about um what a computer is + + align:start position:0% +about um what a computer is + + + align:start position:0% +about um what a computer is +and I think the main takeaway from the + + align:start position:0% +and I think the main takeaway from the + + + align:start position:0% +and I think the main takeaway from the +last lecture is really that a computer + + align:start position:0% +last lecture is really that a computer + + + align:start position:0% +last lecture is really that a computer +only does what it is told right so it's + + align:start position:0% +only does what it is told right so it's + + + align:start position:0% +only does what it is told right so it's +not going to spontaneous spontaneously + + align:start position:0% +not going to spontaneous spontaneously + + + align:start position:0% +not going to spontaneous spontaneously +make decisions on its own you as the + + align:start position:0% +make decisions on its own you as the + + + align:start position:0% +make decisions on its own you as the +programmer have to tell it what you want + + align:start position:0% +programmer have to tell it what you want + + + align:start position:0% +programmer have to tell it what you want +it to do by writing programs okay so we + + align:start position:0% +it to do by writing programs okay so we + + + align:start position:0% +it to do by writing programs okay so we +talked about uh simple objects and um + + align:start position:0% +talked about uh simple objects and um + + + align:start position:0% +talked about uh simple objects and um +these objects were of different types so + + align:start position:0% +these objects were of different types so + + + align:start position:0% +these objects were of different types so +we saw integers floats and booleans and + + align:start position:0% +we saw integers floats and booleans and + + + align:start position:0% +we saw integers floats and booleans and +then we did a couple simple operations + + align:start position:0% +then we did a couple simple operations + + + align:start position:0% +then we did a couple simple operations +with + + align:start position:0% +with + + + align:start position:0% +with +them today we're going to look at a + + align:start position:0% +them today we're going to look at a + + + align:start position:0% +them today we're going to look at a +different a new a new type of object + + align:start position:0% +different a new a new type of object + + + align:start position:0% +different a new a new type of object +called a string and then we're going to + + align:start position:0% +called a string and then we're going to + + + align:start position:0% +called a string and then we're going to +introduce some um more powerful uh um + + align:start position:0% +introduce some um more powerful uh um + + + align:start position:0% +introduce some um more powerful uh um +things in our programming toolbox so + + align:start position:0% +things in our programming toolbox so + + + align:start position:0% +things in our programming toolbox so +we're going to look at how to how to + + align:start position:0% +we're going to look at how to how to + + + align:start position:0% +we're going to look at how to how to +Branch within a program and how to make + + align:start position:0% +Branch within a program and how to make + + + align:start position:0% +Branch within a program and how to make +things how to make the computer repeat + + align:start position:0% +things how to make the computer repeat + + + align:start position:0% +things how to make the computer repeat +certain tasks within our program all + + align:start position:0% +certain tasks within our program all + + + align:start position:0% +certain tasks within our program all +right so let's begin by looking at + + align:start position:0% +right so let's begin by looking at + + + align:start position:0% +right so let's begin by looking at +strings so strings are a new object type + + align:start position:0% +strings so strings are a new object type + + + align:start position:0% +strings so strings are a new object type +we've seen so far integers which were + + align:start position:0% +we've seen so far integers which were + + + align:start position:0% +we've seen so far integers which were +whole numbers floats + + align:start position:0% +whole numbers floats + + + align:start position:0% +whole numbers floats +which were decimal numbers and we have + + align:start position:0% +which were decimal numbers and we have + + + align:start position:0% +which were decimal numbers and we have +seen uh we've seen booleans which were + + align:start position:0% +seen uh we've seen booleans which were + + + align:start position:0% +seen uh we've seen booleans which were +true and false so strings are going to + + align:start position:0% +true and false so strings are going to + + + align:start position:0% +true and false so strings are going to +be uh sequences of characters and these + + align:start position:0% +be uh sequences of characters and these + + + align:start position:0% +be uh sequences of characters and these +characters can be anything they could be + + align:start position:0% +characters can be anything they could be + + + align:start position:0% +characters can be anything they could be +letters digits uh special characters and + + align:start position:0% +letters digits uh special characters and + + + align:start position:0% +letters digits uh special characters and +also + + align:start position:0% +also + + + align:start position:0% +also +spaces and you tell python that you're + + align:start position:0% +spaces and you tell python that you're + + + align:start position:0% +spaces and you tell python that you're +um you're talking about a string object + + align:start position:0% +um you're talking about a string object + + + align:start position:0% +um you're talking about a string object +by enclosing it in quotation marks so in + + align:start position:0% +by enclosing it in quotation marks so in + + + align:start position:0% +by enclosing it in quotation marks so in +this case I'm creating an object um + + align:start position:0% +this case I'm creating an object um + + + align:start position:0% +this case I'm creating an object um +whose value is h e l l space t h + + align:start position:0% +whose value is h e l l space t h + + + align:start position:0% +whose value is h e l l space t h +re and python knows it's a string object + + align:start position:0% +re and python knows it's a string object + + + align:start position:0% +re and python knows it's a string object +because we're enclosing it in quotations + + align:start position:0% +because we're enclosing it in quotations + + + align:start position:0% +because we're enclosing it in quotations +they could be either double quotes or + + align:start position:0% +they could be either double quotes or + + + align:start position:0% +they could be either double quotes or +single quotes but as long as you're + + align:start position:0% +single quotes but as long as you're + + + align:start position:0% +single quotes but as long as you're +consistent it doesn't matter and this + + align:start position:0% +consistent it doesn't matter and this + + + align:start position:0% +consistent it doesn't matter and this +object we're we're um we're binding it + + align:start position:0% +object we're we're um we're binding it + + + align:start position:0% +object we're we're um we're binding it +to this variable named high and we're + + align:start position:0% +to this variable named high and we're + + + align:start position:0% +to this variable named high and we're +using that using the equal sign which is + + align:start position:0% +using that using the equal sign which is + + + align:start position:0% +using that using the equal sign which is +the assignment + + align:start position:0% +the assignment + + + align:start position:0% +the assignment +operator okay so from now on whenever we + + align:start position:0% +operator okay so from now on whenever we + + + align:start position:0% +operator okay so from now on whenever we +refer to this variable High Python's + + align:start position:0% +refer to this variable High Python's + + + align:start position:0% +refer to this variable High Python's +going to say oh I know what the value is + + align:start position:0% +going to say oh I know what the value is + + + align:start position:0% +going to say oh I know what the value is +and it's that string of characters + + align:start position:0% +and it's that string of characters + + + align:start position:0% +and it's that string of characters +so we're going to learn about two things + + align:start position:0% +so we're going to learn about two things + + + align:start position:0% +so we're going to learn about two things +that you can do on strings today two + + align:start position:0% +that you can do on strings today two + + + align:start position:0% +that you can do on strings today two +operations one is to concatenate them + + align:start position:0% +operations one is to concatenate them + + + align:start position:0% +operations one is to concatenate them +and concatenation is really just a fancy + + align:start position:0% +and concatenation is really just a fancy + + + align:start position:0% +and concatenation is really just a fancy +word for using this plus operator which + + align:start position:0% +word for using this plus operator which + + + align:start position:0% +word for using this plus operator which +means put the strings + + align:start position:0% +means put the strings + + + align:start position:0% +means put the strings +together so I have this original um + + align:start position:0% +together so I have this original um + + + align:start position:0% +together so I have this original um +variable named high and I create a new + + align:start position:0% +variable named high and I create a new + + + align:start position:0% +variable named high and I create a new +variable called name and in it I'm going + + align:start position:0% +variable called name and in it I'm going + + + align:start position:0% +variable called name and in it I'm going +to assign I'm going to assign the string + + align:start position:0% +to assign I'm going to assign the string + + + align:start position:0% +to assign I'm going to assign the string +a Ana to the variable name and when I + + align:start position:0% +a Ana to the variable name and when I + + + align:start position:0% +a Ana to the variable name and when I +use the plus operator in between high + + align:start position:0% +use the plus operator in between high + + + align:start position:0% +use the plus operator in between high +and name those two variables python is + + align:start position:0% +and name those two variables python is + + + align:start position:0% +and name those two variables python is +going to look at the values of those two + + align:start position:0% +going to look at the values of those two + + + align:start position:0% +going to look at the values of those two +and it's going to just put them + + align:start position:0% +and it's going to just put them + + + align:start position:0% +and it's going to just put them +together okay I'm going to switch to Sky + + align:start position:0% +together okay I'm going to switch to Sky + + + align:start position:0% +together okay I'm going to switch to Sky +to + + align:start position:0% +to + + + align:start position:0% +to +spider and this is just that example + + align:start position:0% +spider and this is just that example + + + align:start position:0% +spider and this is just that example +from + + align:start position:0% +from + + + align:start position:0% +from +the uh from the slides so let's see what + + align:start position:0% +the uh from the slides so let's see what + + + align:start position:0% +the uh from the slides so let's see what +happens so I have the variable um High + + align:start position:0% +happens so I have the variable um High + + + align:start position:0% +happens so I have the variable um High +the variable name and I'm just + + align:start position:0% +the variable name and I'm just + + + align:start position:0% +the variable name and I'm just +concatenating those two together and + + align:start position:0% +concatenating those two together and + + + align:start position:0% +concatenating those two together and +then I'm going to print that out so if I + + align:start position:0% +then I'm going to print that out so if I + + + align:start position:0% +then I'm going to print that out so if I +I run the + + align:start position:0% +I run the + + + align:start position:0% +I run the +code notice it prints out hello there + + align:start position:0% +code notice it prints out hello there + + + align:start position:0% +code notice it prints out hello there +Anna right there's no space and there's + + align:start position:0% +Anna right there's no space and there's + + + align:start position:0% +Anna right there's no space and there's +no space because the concatenation + + align:start position:0% +no space because the concatenation + + + align:start position:0% +no space because the concatenation +operator the plus uh doesn't add any + + align:start position:0% +operator the plus uh doesn't add any + + + align:start position:0% +operator the plus uh doesn't add any +spaces implicitly so again another + + align:start position:0% +spaces implicitly so again another + + + align:start position:0% +spaces implicitly so again another +example of just computer just doing what + + align:start position:0% +example of just computer just doing what + + + align:start position:0% +example of just computer just doing what +it's told if we want to add a space we'd + + align:start position:0% +it's told if we want to add a space we'd + + + align:start position:0% +it's told if we want to add a space we'd +have to actually insert the space + + align:start position:0% +have to actually insert the space + + + align:start position:0% +have to actually insert the space +manually so that's this line here line + + align:start position:0% +manually so that's this line here line + + + align:start position:0% +manually so that's this line here line +eight and in this line we're + + align:start position:0% +eight and in this line we're + + + align:start position:0% +eight and in this line we're +concatenating the VAR the the value of + + align:start position:0% +concatenating the VAR the the value of + + + align:start position:0% +concatenating the VAR the the value of +the variable High with a space notice + + align:start position:0% +the variable High with a space notice + + + align:start position:0% +the variable High with a space notice +we're putting it in quotation marks just + + align:start position:0% +we're putting it in quotation marks just + + + align:start position:0% +we're putting it in quotation marks just +a space and then with + + align:start position:0% +a space and then with + + + align:start position:0% +a space and then with +name so if we go ahead and print that + + align:start position:0% +name so if we go ahead and print that + + + align:start position:0% +name so if we go ahead and print that +value notice this was + + align:start position:0% +value notice this was + + + align:start position:0% +value notice this was +that garbage greeting there and now we + + align:start position:0% +that garbage greeting there and now we + + + align:start position:0% +that garbage greeting there and now we +have a proper greeting + + align:start position:0% + + + + align:start position:0% + +right another so that's the + + align:start position:0% +right another so that's the + + + align:start position:0% +right another so that's the +concatenation um between strings and + + align:start position:0% +concatenation um between strings and + + + align:start position:0% +concatenation um between strings and +then the other thing we're going to look + + align:start position:0% +then the other thing we're going to look + + + align:start position:0% +then the other thing we're going to look +at uh related to Strings is the star + + align:start position:0% +at uh related to Strings is the star + + + align:start position:0% +at uh related to Strings is the star +operator so that's this one here on line + + align:start position:0% +operator so that's this one here on line + + + align:start position:0% +operator so that's this one here on line +10 so python allows you to use the star + + align:start position:0% +10 so python allows you to use the star + + + align:start position:0% +10 so python allows you to use the star +operator which is stands for + + align:start position:0% +operator which is stands for + + + align:start position:0% +operator which is stands for +multiplication between a string and a + + align:start position:0% +multiplication between a string and a + + + align:start position:0% +multiplication between a string and a +number and when you do that python + + align:start position:0% +number and when you do that python + + + align:start position:0% +number and when you do that python +interpret interprets it + + align:start position:0% +interpret interprets it + + + align:start position:0% +interpret interprets it +as repeat that string that many number + + align:start position:0% +as repeat that string that many number + + + align:start position:0% +as repeat that string that many number +of + + align:start position:0% +of + + + align:start position:0% +of +times so in this case I'm creating a + + align:start position:0% +times so in this case I'm creating a + + + align:start position:0% +times so in this case I'm creating a +silly greeting and I'm concatenating the + + align:start position:0% +silly greeting and I'm concatenating the + + + align:start position:0% +silly greeting and I'm concatenating the +value of high which is hello there with + + align:start position:0% +value of high which is hello there with + + + align:start position:0% +value of high which is hello there with +the space plus the name so notice here + + align:start position:0% +the space plus the name so notice here + + + align:start position:0% +the space plus the name so notice here +I'm using parentheses to tell python do + + align:start position:0% +I'm using parentheses to tell python do + + + align:start position:0% +I'm using parentheses to tell python do +this operation first and then multiply + + align:start position:0% +this operation first and then multiply + + + align:start position:0% +this operation first and then multiply +whatever the result of this is by + + align:start position:0% +whatever the result of this is by + + + align:start position:0% +whatever the result of this is by +three okay so if I print that + + align:start position:0% +three okay so if I print that + + + align:start position:0% +three okay so if I print that +out it's going to multiply the space + + align:start position:0% +out it's going to multiply the space + + + align:start position:0% +out it's going to multiply the space +with my name three times and it's going + + align:start position:0% +with my name three times and it's going + + + align:start position:0% +with my name three times and it's going +to concatenate that with hello there so + + align:start position:0% +to concatenate that with hello there so + + + align:start position:0% +to concatenate that with hello there so +that's exactly what it printed out + + align:start position:0% +that's exactly what it printed out + + + align:start position:0% +that's exactly what it printed out +there last lecture we talked a little + + align:start position:0% +there last lecture we talked a little + + + align:start position:0% +there last lecture we talked a little +bit about about print today I'm going to + + align:start position:0% +bit about about print today I'm going to + + + align:start position:0% +bit about about print today I'm going to +talk uh about some nuances related to + + align:start position:0% +talk uh about some nuances related to + + + align:start position:0% +talk uh about some nuances related to +print so you use print to interact with + + align:start position:0% +print so you use print to interact with + + + align:start position:0% +print so you use print to interact with +the user um it's cool to write programs + + align:start position:0% +the user um it's cool to write programs + + + align:start position:0% +the user um it's cool to write programs +that print things out to the user so the + + align:start position:0% +that print things out to the user so the + + + align:start position:0% +that print things out to the user so the +keyword here being print and then you + + align:start position:0% +keyword here being print and then you + + + align:start position:0% +keyword here being print and then you +put parentheses after print and in the + + align:start position:0% +put parentheses after print and in the + + + align:start position:0% +put parentheses after print and in the +parentheses you put in whatever you want + + align:start position:0% +parentheses you put in whatever you want + + + align:start position:0% +parentheses you put in whatever you want +to show the + + align:start position:0% +to show the + + + align:start position:0% +to show the +user so in this little program I have + + align:start position:0% +user so in this little program I have + + + align:start position:0% +user so in this little program I have +I create a variable named X I assign it + + align:start position:0% +I create a variable named X I assign it + + + align:start position:0% +I create a variable named X I assign it +the value one and then I print + + align:start position:0% +the value one and then I print + + + align:start position:0% +the value one and then I print +one here I'm + + align:start position:0% +one here I'm + + + align:start position:0% +one here I'm +casting so I'm taking the number one the + + align:start position:0% +casting so I'm taking the number one the + + + align:start position:0% +casting so I'm taking the number one the +integer one and I'm casting it to a + + align:start position:0% +integer one and I'm casting it to a + + + align:start position:0% +integer one and I'm casting it to a +string and you'll see why in a + + align:start position:0% +string and you'll see why in a + + + align:start position:0% +string and you'll see why in a +moment so I want to bring to your + + align:start position:0% +moment so I want to bring to your + + + align:start position:0% +moment so I want to bring to your +attention a couple things here so in the + + align:start position:0% +attention a couple things here so in the + + + align:start position:0% +attention a couple things here so in the +first print I'm using commas everywhere + + align:start position:0% +first print I'm using commas everywhere + + + align:start position:0% +first print I'm using commas everywhere +here and then the second print I'm using + + align:start position:0% +here and then the second print I'm using + + + align:start position:0% +here and then the second print I'm using +plus okay + + align:start position:0% +plus okay + + + align:start position:0% +plus okay +so by definition if you you can use + + align:start position:0% +so by definition if you you can use + + + align:start position:0% +so by definition if you you can use +print you can use commas inside a print + + align:start position:0% +print you can use commas inside a print + + + align:start position:0% +print you can use commas inside a print +inside the parenthesis of + + align:start position:0% +inside the parenthesis of + + + align:start position:0% +inside the parenthesis of +print and if you use a comma Python's + + align:start position:0% +print and if you use a comma Python's + + + align:start position:0% +print and if you use a comma Python's +going to automatically add a space in + + align:start position:0% +going to automatically add a space in + + + align:start position:0% +going to automatically add a space in +between the two things that the comma is + + align:start position:0% +between the two things that the comma is + + + align:start position:0% +between the two things that the comma is +in in between the values so my fav num + + align:start position:0% +in in between the values so my fav num + + + align:start position:0% +in in between the values so my fav num +is is the first thing and the second + + align:start position:0% +is is the first thing and the second + + + align:start position:0% +is is the first thing and the second +thing is whatever is after the + + align:start position:0% +thing is whatever is after the + + + align:start position:0% +thing is whatever is after the +comma let's take X so if you use a comma + + align:start position:0% +comma let's take X so if you use a comma + + + align:start position:0% +comma let's take X so if you use a comma +Python's going to automatically insert a + + align:start position:0% +Python's going to automatically insert a + + + align:start position:0% +Python's going to automatically insert a +space for you okay sometimes you might + + align:start position:0% +space for you okay sometimes you might + + + align:start position:0% +space for you okay sometimes you might +want that sometimes you might not if you + + align:start position:0% +want that sometimes you might not if you + + + align:start position:0% +want that sometimes you might not if you +don't want that you can use the + + align:start position:0% +don't want that you can use the + + + align:start position:0% +don't want that you can use the +concatenation operation the plus and you + + align:start position:0% +concatenation operation the plus and you + + + align:start position:0% +concatenation operation the plus and you +can add all of your little bits together + + align:start position:0% +can add all of your little bits together + + + align:start position:0% +can add all of your little bits together +to create one big + + align:start position:0% +to create one big + + + align:start position:0% +to create one big +string if you're using commas the the + + align:start position:0% +string if you're using commas the the + + + align:start position:0% +string if you're using commas the the +items the objects in between the commas + + align:start position:0% +items the objects in between the commas + + + align:start position:0% +items the objects in between the commas +do not all have to be strings that's the + + align:start position:0% +do not all have to be strings that's the + + + align:start position:0% +do not all have to be strings that's the +plus side of using commas but the noun + + align:start position:0% +plus side of using commas but the noun + + + align:start position:0% +plus side of using commas but the noun +side is you get spaces everywhere + + align:start position:0% +side is you get spaces everywhere + + + align:start position:0% +side is you get spaces everywhere +if you use + + align:start position:0% +if you use + + + align:start position:0% +if you use +plus operator the plus side is python + + align:start position:0% +plus operator the plus side is python + + + align:start position:0% +plus operator the plus side is python +does exactly what you tell it to do but + + align:start position:0% +does exactly what you tell it to do but + + + align:start position:0% +does exactly what you tell it to do but +everything has to be a string object so + + align:start position:0% +everything has to be a string object so + + + align:start position:0% +everything has to be a string object so +my fave num is is a string object you + + align:start position:0% +my fave num is is a string object you + + + align:start position:0% +my fave num is is a string object you +have to convert all of your numbers to + + align:start position:0% +have to convert all of your numbers to + + + align:start position:0% +have to convert all of your numbers to +string objects and so + + align:start position:0% +string objects and so + + + align:start position:0% +string objects and so +on so if we look at + + align:start position:0% + + + + align:start position:0% + +spider this is the same almost the same + + align:start position:0% +spider this is the same almost the same + + + align:start position:0% +spider this is the same almost the same +code so here I don't have spaces + + align:start position:0% +code so here I don't have spaces + + + align:start position:0% +code so here I don't have spaces +anywhere so you can see that the first + + align:start position:0% +anywhere so you can see that the first + + + align:start position:0% +anywhere so you can see that the first +line here has commas everywhere so I'm + + align:start position:0% +line here has commas everywhere so I'm + + + align:start position:0% +line here has commas everywhere so I'm +going to have spaces in between every + + align:start position:0% +going to have spaces in between every + + + align:start position:0% +going to have spaces in between every +one of the things that I'm um that I'm + + align:start position:0% +one of the things that I'm um that I'm + + + align:start position:0% +one of the things that I'm um that I'm +printing + + align:start position:0% +printing + + + align:start position:0% +printing +out this line here is sort of a + + align:start position:0% +out this line here is sort of a + + + align:start position:0% +out this line here is sort of a +combination between Comm commas and + + align:start position:0% +combination between Comm commas and + + + align:start position:0% +combination between Comm commas and +concatenation so depending on where I + + align:start position:0% +concatenation so depending on where I + + + align:start position:0% +concatenation so depending on where I +use the comma I'm going to have an extra + + align:start position:0% +use the comma I'm going to have an extra + + + align:start position:0% +use the comma I'm going to have an extra +space and this line here just has + + align:start position:0% +space and this line here just has + + + align:start position:0% +space and this line here just has +concatenation everywhere okay so if I + + align:start position:0% +concatenation everywhere okay so if I + + + align:start position:0% +concatenation everywhere okay so if I +run + + align:start position:0% +run + + + align:start position:0% +run +this notice this very first line added + + align:start position:0% +this notice this very first line added + + + align:start position:0% +this notice this very first line added +spaces everywhere in between all my + + align:start position:0% +spaces everywhere in between all my + + + align:start position:0% +spaces everywhere in between all my +objects the second one added spaces + + align:start position:0% +objects the second one added spaces + + + align:start position:0% +objects the second one added spaces +somewhere and you can sort of Trace + + align:start position:0% +somewhere and you can sort of Trace + + + align:start position:0% +somewhere and you can sort of Trace +through and see exactly where the spaces + + align:start position:0% +through and see exactly where the spaces + + + align:start position:0% +through and see exactly where the spaces +were added and the last line + + align:start position:0% +were added and the last line + + + align:start position:0% +were added and the last line +here didn't add spaces anywhere + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so printing things out to the console is + + align:start position:0% +so printing things out to the console is + + + align:start position:0% +so printing things out to the console is +nice but the second part of sort of + + align:start position:0% +nice but the second part of sort of + + + align:start position:0% +nice but the second part of sort of +writing an interactive program is + + align:start position:0% +writing an interactive program is + + + align:start position:0% +writing an interactive program is +getting input from the user and that's + + align:start position:0% +getting input from the user and that's + + + align:start position:0% +getting input from the user and that's +that's a more interesting part so if + + align:start position:0% +that's a more interesting part so if + + + align:start position:0% +that's a more interesting part so if +you've done problem set zero you might + + align:start position:0% +you've done problem set zero you might + + + align:start position:0% +you've done problem set zero you might +have sort of already tried to understand + + align:start position:0% +have sort of already tried to understand + + + align:start position:0% +have sort of already tried to understand +this on your own but here we are + + align:start position:0% +this on your own but here we are + + + align:start position:0% +this on your own but here we are +so the way you get input from the user + + align:start position:0% +so the way you get input from the user + + + align:start position:0% +so the way you get input from the user +is using this command function called + + align:start position:0% +is using this command function called + + + align:start position:0% +is using this command function called +input + + align:start position:0% +input + + + align:start position:0% +input +and inside the + + align:start position:0% +and inside the + + + align:start position:0% +and inside the +parentheses you type in whatever you'd + + align:start position:0% +parentheses you type in whatever you'd + + + align:start position:0% +parentheses you type in whatever you'd +like to prompt the user with so in this + + align:start position:0% +like to prompt the user with so in this + + + align:start position:0% +like to prompt the user with so in this +case in my example here I have input and + + align:start position:0% +case in my example here I have input and + + + align:start position:0% +case in my example here I have input and +then here I said type anything so the + + align:start position:0% +then here I said type anything so the + + + align:start position:0% +then here I said type anything so the +user is going to see this text here and + + align:start position:0% +user is going to see this text here and + + + align:start position:0% +user is going to see this text here and +then the program is just going to stop + + align:start position:0% +then the program is just going to stop + + + align:start position:0% +then the program is just going to stop +and it's going to wait for the user to + + align:start position:0% +and it's going to wait for the user to + + + align:start position:0% +and it's going to wait for the user to +type in something and hit + + align:start position:0% +type in something and hit + + + align:start position:0% +type in something and hit +enter as soon as the user types in + + align:start position:0% +enter as soon as the user types in + + + align:start position:0% +enter as soon as the user types in +enter whatever the user types in becomes + + align:start position:0% +enter whatever the user types in becomes + + + align:start position:0% +enter whatever the user types in becomes +a string okay if the user types in a + + align:start position:0% +a string okay if the user types in a + + + align:start position:0% +a string okay if the user types in a +number for example that becomes the + + align:start position:0% +number for example that becomes the + + + align:start position:0% +number for example that becomes the +string that number okay so everything + + align:start position:0% +string that number okay so everything + + + align:start position:0% +string that number okay so everything +that user types in is going to be made + + align:start position:0% +that user types in is going to be made + + + align:start position:0% +that user types in is going to be made +as a + + align:start position:0% + + + + align:start position:0% + +string in this line right here whatever + + align:start position:0% +string in this line right here whatever + + + align:start position:0% +string in this line right here whatever +the user types in becomes a string and + + align:start position:0% +the user types in becomes a string and + + + align:start position:0% +the user types in becomes a string and +we're going to bind that string object + + align:start position:0% +we're going to bind that string object + + + align:start position:0% +we're going to bind that string object +to this variable named uh called text + + align:start position:0% +to this variable named uh called text + + + align:start position:0% +to this variable named uh called text +okay so now further in my program I can + + align:start position:0% +okay so now further in my program I can + + + align:start position:0% +okay so now further in my program I can +do whatever I want with this variable + + align:start position:0% +do whatever I want with this variable + + + align:start position:0% +do whatever I want with this variable +text in this case I'm going to print + + align:start position:0% +text in this case I'm going to print + + + align:start position:0% +text in this case I'm going to print +five star + + align:start position:0% +five star + + + align:start position:0% +five star +text okay so if the user for example + + align:start position:0% +text okay so if the user for example + + + align:start position:0% +text okay so if the user for example +gave me ha I'm going to print ha five + + align:start position:0% +gave me ha I'm going to print ha five + + + align:start position:0% +gave me ha I'm going to print ha five +times if the user gave me + + align:start position:0% +times if the user gave me + + + align:start position:0% +times if the user gave me +five what do you think the user what do + + align:start position:0% +five what do you think the user what do + + + align:start position:0% +five what do you think the user what do +you think is going to be printed + + align:start position:0% +you think is going to be printed + + + align:start position:0% +you think is going to be printed +out 25 or five five + + align:start position:0% +out 25 or five five + + + align:start position:0% +out 25 or five five +times great yes exactly five five times + + align:start position:0% +times great yes exactly five five times + + + align:start position:0% +times great yes exactly five five times +okay often times you don't want to work + + align:start position:0% +okay often times you don't want to work + + + align:start position:0% +okay often times you don't want to work +with numbers as strings right you want + + align:start position:0% +with numbers as strings right you want + + + align:start position:0% +with numbers as strings right you want +to work with numbers as numbers right so + + align:start position:0% +to work with numbers as numbers right so + + + align:start position:0% +to work with numbers as numbers right so +you have to cast and we learned that + + align:start position:0% +you have to cast and we learned that + + + align:start position:0% +you have to cast and we learned that +last lecture you cast by just putting in + + align:start position:0% +last lecture you cast by just putting in + + + align:start position:0% +last lecture you cast by just putting in +this little bit right in front of the + + align:start position:0% +this little bit right in front of the + + + align:start position:0% +this little bit right in front of the +input and you can cast it to whatever + + align:start position:0% +input and you can cast it to whatever + + + align:start position:0% +input and you can cast it to whatever +type you want here I cast it to an INT + + align:start position:0% +type you want here I cast it to an INT + + + align:start position:0% +type you want here I cast it to an INT +but you can also cast to a float if you + + align:start position:0% +but you can also cast to a float if you + + + align:start position:0% +but you can also cast to a float if you +want to work with + + align:start position:0% +want to work with + + + align:start position:0% +want to work with +floats and that converts whatever the + + align:start position:0% +floats and that converts whatever the + + + align:start position:0% +floats and that converts whatever the +user typed in as long as it's some + + align:start position:0% +user typed in as long as it's some + + + align:start position:0% +user typed in as long as it's some +number that python knows how to how to + + align:start position:0% +number that python knows how to how to + + + align:start position:0% +number that python knows how to how to +convert into the number itself so in + + align:start position:0% +convert into the number itself so in + + + align:start position:0% +convert into the number itself so in +this case if the user gives me five I'm + + align:start position:0% +this case if the user gives me five I'm + + + align:start position:0% +this case if the user gives me five I'm +going to print out 5 * 5 instead of five + + align:start position:0% +going to print out 5 * 5 instead of five + + + align:start position:0% +going to print out 5 * 5 instead of five +five + + align:start position:0% +five + + + align:start position:0% +five +times + + align:start position:0% + + + + align:start position:0% + +so that's the code + + align:start position:0% +so that's the code + + + align:start position:0% +so that's the code +here so the first bit is I'm going to + + align:start position:0% +here so the first bit is I'm going to + + + align:start position:0% +here so the first bit is I'm going to +get the user to type in anything and I'm + + align:start position:0% +get the user to type in anything and I'm + + + align:start position:0% +get the user to type in anything and I'm +going + + align:start position:0% +going + + + align:start position:0% +going +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +to put 555 and then when I type in the + + align:start position:0% +to put 555 and then when I type in the + + + align:start position:0% +to put 555 and then when I type in the +number since I'm casting it I'm going to + + align:start position:0% +number since I'm casting it I'm going to + + + align:start position:0% +number since I'm casting it I'm going to +do operations with the number okay yeah + + align:start position:0% +do operations with the number okay yeah + + + align:start position:0% +do operations with the number okay yeah +question + + align:start position:0% + + + + align:start position:0% + +in why do you want to cast + + align:start position:0% + + + + align:start position:0% + +to oh uh the question is why do you want + + align:start position:0% +to oh uh the question is why do you want + + + align:start position:0% +to oh uh the question is why do you want +to cast to a + + align:start position:0% +to cast to a + + + align:start position:0% +to cast to a +string why do you want to cast a string + + align:start position:0% +string why do you want to cast a string + + + align:start position:0% +string why do you want to cast a string +to a + + align:start position:0% + + + + align:start position:0% + +number oh so python always whatever you + + align:start position:0% +number oh so python always whatever you + + + align:start position:0% +number oh so python always whatever you +whatever you type in just by default by + + align:start position:0% +whatever you type in just by default by + + + align:start position:0% +whatever you type in just by default by +definition of the input command python + + align:start position:0% +definition of the input command python + + + align:start position:0% +definition of the input command python +always makes it a + + align:start position:0% +always makes it a + + + align:start position:0% +always makes it a +string so if you want to work with + + align:start position:0% +string so if you want to work with + + + align:start position:0% +string so if you want to work with +numbers you have to explicitly tell it + + align:start position:0% +numbers you have to explicitly tell it + + + align:start position:0% +numbers you have to explicitly tell it +I'm going to work with a number so even + + align:start position:0% +I'm going to work with a number so even + + + align:start position:0% +I'm going to work with a number so even +if you give it the number five it's + + align:start position:0% +if you give it the number five it's + + + align:start position:0% +if you give it the number five it's +going to think it's the string + + align:start position:0% +going to think it's the string + + + align:start position:0% +going to think it's the string +five yeah that's just how input + + align:start position:0% + + + + align:start position:0% + +works the next thing it we're going to + + align:start position:0% +works the next thing it we're going to + + + align:start position:0% +works the next thing it we're going to +look at is ways that you can um start + + align:start position:0% +look at is ways that you can um start + + + align:start position:0% +look at is ways that you can um start +adding tests in your code and before you + + align:start position:0% +adding tests in your code and before you + + + align:start position:0% +adding tests in your code and before you +can start adding tests before you can + + align:start position:0% +can start adding tests before you can + + + align:start position:0% +can start adding tests before you can +start adding tests in your code you need + + align:start position:0% +start adding tests in your code you need + + + align:start position:0% +start adding tests in your code you need +to be able to do the actual tests + + align:start position:0% +to be able to do the actual tests + + + align:start position:0% +to be able to do the actual tests +so this is where comparison operators + + align:start position:0% +so this is where comparison operators + + + align:start position:0% +so this is where comparison operators +come + + align:start position:0% +come + + + align:start position:0% +come +in okay so here let's assume that I and + + align:start position:0% +in okay so here let's assume that I and + + + align:start position:0% +in okay so here let's assume that I and +J are variables okay the following + + align:start position:0% +J are variables okay the following + + + align:start position:0% +J are variables okay the following +comparisons are going to give you a + + align:start position:0% +comparisons are going to give you a + + + align:start position:0% +comparisons are going to give you a +Boolean so it's either going to say this + + align:start position:0% +Boolean so it's either going to say this + + + align:start position:0% +Boolean so it's either going to say this +is true or this is false so that's going + + align:start position:0% +is true or this is false so that's going + + + align:start position:0% +is true or this is false so that's going +to be your + + align:start position:0% +to be your + + + align:start position:0% +to be your +test so if I and J are variables you're + + align:start position:0% +test so if I and J are variables you're + + + align:start position:0% +test so if I and J are variables you're +allowed to compare ins with ins floats + + align:start position:0% +allowed to compare ins with ins floats + + + align:start position:0% +allowed to compare ins with ins floats +with floats strings with strings and + + align:start position:0% +with floats strings with strings and + + + align:start position:0% +with floats strings with strings and +you're allowed to compare ins and floats + + align:start position:0% +you're allowed to compare ins and floats + + + align:start position:0% +you're allowed to compare ins and floats +between themselves but you're not + + align:start position:0% +between themselves but you're not + + + align:start position:0% +between themselves but you're not +allowed to compare a string with a + + align:start position:0% +allowed to compare a string with a + + + align:start position:0% +allowed to compare a string with a +number in fact if you even try to do + + align:start position:0% +number in fact if you even try to do + + + align:start position:0% +number in fact if you even try to do +that in Python in spyer here if I try to + + align:start position:0% +that in Python in spyer here if I try to + + + align:start position:0% +that in Python in spyer here if I try to +say is the letter a greater than + + align:start position:0% +say is the letter a greater than + + + align:start position:0% +say is the letter a greater than +five I get some angry + + align:start position:0% +five I get some angry + + + align:start position:0% +five I get some angry +text right right here and this just + + align:start position:0% +text right right here and this just + + + align:start position:0% +text right right here and this just +tells me python doesn't understand the + + align:start position:0% +tells me python doesn't understand the + + + align:start position:0% +tells me python doesn't understand the +meaning of what how do I compare a + + align:start position:0% +meaning of what how do I compare a + + + align:start position:0% +meaning of what how do I compare a +string with a number right + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so just like in math we can do these + + align:start position:0% +so just like in math we can do these + + + align:start position:0% +so just like in math we can do these +usual comparisons we can say something's + + align:start position:0% +usual comparisons we can say something's + + + align:start position:0% +usual comparisons we can say something's +greater than something greater or equal + + align:start position:0% +greater than something greater or equal + + + align:start position:0% +greater than something greater or equal +to less than less than or equal to I'd + + align:start position:0% +to less than less than or equal to I'd + + + align:start position:0% +to less than less than or equal to I'd +like to bring to your attention the + + align:start position:0% +like to bring to your attention the + + + align:start position:0% +like to bring to your attention the +equality so the single equal sign is an + + align:start position:0% +equality so the single equal sign is an + + + align:start position:0% +equality so the single equal sign is an +assignment so you're taking a value and + + align:start position:0% +assignment so you're taking a value and + + + align:start position:0% +assignment so you're taking a value and +you're signing it to a variable but when + + align:start position:0% +you're signing it to a variable but when + + + align:start position:0% +you're signing it to a variable but when +you're doing the double equal sign this + + align:start position:0% +you're doing the double equal sign this + + + align:start position:0% +you're doing the double equal sign this +is the test for equality is the value of + + align:start position:0% +is the test for equality is the value of + + + align:start position:0% +is the test for equality is the value of +variable I the same as the value of the + + align:start position:0% +variable I the same as the value of the + + + align:start position:0% +variable I the same as the value of the +variable J okay and that's that's again + + align:start position:0% +variable J okay and that's that's again + + + align:start position:0% +variable J okay and that's that's again +also going to give you a Boolean either + + align:start position:0% +also going to give you a Boolean either + + + align:start position:0% +also going to give you a Boolean either +true or false and you can also test for + + align:start position:0% +true or false and you can also test for + + + align:start position:0% +true or false and you can also test for +inequality with the exclamation equal so + + align:start position:0% +inequality with the exclamation equal so + + + align:start position:0% +inequality with the exclamation equal so +that means is the V value of the + + align:start position:0% +that means is the V value of the + + + align:start position:0% +that means is the V value of the +variable I not equal to the value of the + + align:start position:0% +variable I not equal to the value of the + + + align:start position:0% +variable I not equal to the value of the +variable J true if yes false if + + align:start position:0% + + + + align:start position:0% + +no okay so those are comparison + + align:start position:0% +no okay so those are comparison + + + align:start position:0% +no okay so those are comparison +operators on Integer floats and strings + + align:start position:0% +operators on Integer floats and strings + + + align:start position:0% +operators on Integer floats and strings +on booleans you can do some logic + + align:start position:0% +on booleans you can do some logic + + + align:start position:0% +on booleans you can do some logic +operators + + align:start position:0% +operators + + + align:start position:0% +operators +and the simplest is just inverting so if + + align:start position:0% +and the simplest is just inverting so if + + + align:start position:0% +and the simplest is just inverting so if +a is a v if a is a variable that can + + align:start position:0% +a is a v if a is a variable that can + + + align:start position:0% +a is a v if a is a variable that can +that has a Boolean value not a is just + + align:start position:0% +that has a Boolean value not a is just + + + align:start position:0% +that has a Boolean value not a is just +going to invert it so if a is true then + + align:start position:0% +going to invert it so if a is true then + + + align:start position:0% +going to invert it so if a is true then +not a is false and vice + + align:start position:0% +not a is false and vice + + + align:start position:0% +not a is false and vice +versa this is a table that sort of + + align:start position:0% +versa this is a table that sort of + + + align:start position:0% +versa this is a table that sort of +represents what I've said here so you + + align:start position:0% +represents what I've said here so you + + + align:start position:0% +represents what I've said here so you +can do you can use and and or these are + + align:start position:0% +can do you can use and and or these are + + + align:start position:0% +can do you can use and and or these are +keywords in Python you can use those two + + align:start position:0% +keywords in Python you can use those two + + + align:start position:0% +keywords in Python you can use those two +keywords on variables on Boolean + + align:start position:0% +keywords on variables on Boolean + + + align:start position:0% +keywords on variables on Boolean +variables and you get the + + align:start position:0% +variables and you get the + + + align:start position:0% +variables and you get the +result A and B is only true if both A + + align:start position:0% +result A and B is only true if both A + + + align:start position:0% +result A and B is only true if both A +and B are + + align:start position:0% +and B are + + + align:start position:0% +and B are +true and A or B is only false if a and b + + align:start position:0% +true and A or B is only false if a and b + + + align:start position:0% +true and A or B is only false if a and b +are false okay and this is the complete + + align:start position:0% +are false okay and this is the complete + + + align:start position:0% +are false okay and this is the complete +table just in case you need to reference + + align:start position:0% + + + + align:start position:0% + +it all right so now that we have ways to + + align:start position:0% +it all right so now that we have ways to + + + align:start position:0% +it all right so now that we have ways to +do logical te Yeah question right there + + align:start position:0% +do logical te Yeah question right there + + + align:start position:0% +do logical te Yeah question right there +what does + + align:start position:0% + + + + align:start position:0% + +it yeah great question so what does it + + align:start position:0% +it yeah great question so what does it + + + align:start position:0% +it yeah great question so what does it +mean to compare string with a string + + align:start position:0% +mean to compare string with a string + + + align:start position:0% +mean to compare string with a string +with the greater than so that's just + + align:start position:0% +with the greater than so that's just + + + align:start position:0% +with the greater than so that's just +going to compare them uh + + align:start position:0% +going to compare them uh + + + align:start position:0% +going to compare them uh +lexicographically so does it come first + + align:start position:0% +lexicographically so does it come first + + + align:start position:0% +lexicographically so does it come first +in the + + align:start position:0% +in the + + + align:start position:0% +in the +alphabet so we can even test that out we + + align:start position:0% +alphabet so we can even test that out we + + + align:start position:0% +alphabet so we can even test that out we +can say is a greater than + + align:start position:0% +can say is a greater than + + + align:start position:0% +can say is a greater than +b and it's + + align:start position:0% + + + + align:start position:0% + +false so b b comes later in the alphabet + + align:start position:0% +false so b b comes later in the alphabet + + + align:start position:0% +false so b b comes later in the alphabet +than a + + align:start position:0% + + + + align:start position:0% + +right okay so now we have ways to do the + + align:start position:0% +right okay so now we have ways to do the + + + align:start position:0% +right okay so now we have ways to do the +tests so we can add + + align:start position:0% +tests so we can add + + + align:start position:0% +tests so we can add +um some branching to our programming + + align:start position:0% +um some branching to our programming + + + align:start position:0% +um some branching to our programming +toolbox now that we have ways to do + + align:start position:0% +toolbox now that we have ways to do + + + align:start position:0% +toolbox now that we have ways to do +tests okay this is a map of MIT I'm + + align:start position:0% +tests okay this is a map of MIT I'm + + + align:start position:0% +tests okay this is a map of MIT I'm +going to go through sort of a little + + align:start position:0% +going to go through sort of a little + + + align:start position:0% +going to go through sort of a little +example to motivate why we want to do + + align:start position:0% +example to motivate why we want to do + + + align:start position:0% +example to motivate why we want to do +branching in our in our um in our code + + align:start position:0% +branching in our in our um in our code + + + align:start position:0% +branching in our in our um in our code +and I think after this lecture you'll be + + align:start position:0% +and I think after this lecture you'll be + + + align:start position:0% +and I think after this lecture you'll be +able to sort of code up this algorithm + + align:start position:0% +able to sort of code up this algorithm + + + align:start position:0% +able to sort of code up this algorithm +that I'm going to explain so most of us + + align:start position:0% +that I'm going to explain so most of us + + + align:start position:0% +that I'm going to explain so most of us +see MIT as a maze I first did when I + + align:start position:0% +see MIT as a maze I first did when I + + + align:start position:0% +see MIT as a maze I first did when I +came + + align:start position:0% + + + + align:start position:0% + +here when I first came here obviously I + + align:start position:0% +here when I first came here obviously I + + + align:start position:0% +here when I first came here obviously I +signed up for the free food mailing list + + align:start position:0% +signed up for the free food mailing list + + + align:start position:0% +signed up for the free food mailing list +and MIT MIT being am maaz I had no idea + + align:start position:0% +and MIT MIT being am maaz I had no idea + + + align:start position:0% +and MIT MIT being am maaz I had no idea +where to go right what the shortest path + + align:start position:0% +where to go right what the shortest path + + + align:start position:0% +where to go right what the shortest path +was to free food so one way to to think + + align:start position:0% +was to free food so one way to to think + + + align:start position:0% +was to free food so one way to to think +about it is all I wanted to do was get + + align:start position:0% +about it is all I wanted to do was get + + + align:start position:0% +about it is all I wanted to do was get +to the free + + align:start position:0% +to the free + + + align:start position:0% +to the free +food a very simple algorithm to get + + align:start position:0% +food a very simple algorithm to get + + + align:start position:0% +food a very simple algorithm to get +there would be to say okay I'm going to + + align:start position:0% +there would be to say okay I'm going to + + + align:start position:0% +there would be to say okay I'm going to +take my right hand and I'm going to make + + align:start position:0% +take my right hand and I'm going to make + + + align:start position:0% +take my right hand and I'm going to make +sure that my right hand is always on a + + align:start position:0% +sure that my right hand is always on a + + + align:start position:0% +sure that my right hand is always on a +wall okay and I'm going to go around + + align:start position:0% +wall okay and I'm going to go around + + + align:start position:0% +wall okay and I'm going to go around +campus with my right hand always being + + align:start position:0% +campus with my right hand always being + + + align:start position:0% +campus with my right hand always being +at a wall and eventually I'll get to the + + align:start position:0% +at a wall and eventually I'll get to the + + + align:start position:0% +at a wall and eventually I'll get to the +where the free food is I might not there + + align:start position:0% +where the free food is I might not there + + + align:start position:0% +where the free food is I might not there +might not be any left right but I'll be + + align:start position:0% +might not be any left right but I'll be + + + align:start position:0% +might not be any left right but I'll be +there okay so the algorithm is as + + align:start position:0% +there okay so the algorithm is as + + + align:start position:0% +there okay so the algorithm is as +follows okay if my right hand always has + + align:start position:0% +follows okay if my right hand always has + + + align:start position:0% +follows okay if my right hand always has +to be on a wall then I'm going to say if + + align:start position:0% +to be on a wall then I'm going to say if + + + align:start position:0% +to be on a wall then I'm going to say if +there's no wall to my right side then + + align:start position:0% +there's no wall to my right side then + + + align:start position:0% +there's no wall to my right side then +I'm going to go right until I get to a + + align:start position:0% +I'm going to go right until I get to a + + + align:start position:0% +I'm going to go right until I get to a +wall + + align:start position:0% +wall + + + align:start position:0% +wall +Okay + + align:start position:0% +Okay + + + align:start position:0% +Okay +then if there's a wall to my right and I + + align:start position:0% +then if there's a wall to my right and I + + + align:start position:0% +then if there's a wall to my right and I +can go forward I'm just going to keep + + align:start position:0% +can go forward I'm just going to keep + + + align:start position:0% +can go forward I'm just going to keep +going forward + + align:start position:0% +going forward + + + align:start position:0% +going forward +okay if I keep going forward and there's + + align:start position:0% +okay if I keep going forward and there's + + + align:start position:0% +okay if I keep going forward and there's +a wall to my right in front of me I'm + + align:start position:0% +a wall to my right in front of me I'm + + + align:start position:0% +a wall to my right in front of me I'm +going to turn around and go left okay + + align:start position:0% +going to turn around and go left okay + + + align:start position:0% +going to turn around and go left okay +and then if there's a wall to my right + + align:start position:0% +and then if there's a wall to my right + + + align:start position:0% +and then if there's a wall to my right +in front of me and to the left then I'm + + align:start position:0% +in front of me and to the left then I'm + + + align:start position:0% +in front of me and to the left then I'm +going to turn around and go back so with + + align:start position:0% +going to turn around and go back so with + + + align:start position:0% +going to turn around and go back so with +this fairly simple + + align:start position:0% +this fairly simple + + + align:start position:0% +this fairly simple +algorithm I just follow the the path + + align:start position:0% +algorithm I just follow the the path + + + align:start position:0% +algorithm I just follow the the path +always keeping the wall to my + + align:start position:0% +always keeping the wall to my + + + align:start position:0% +always keeping the wall to my +right and eventually I end up where I + + align:start position:0% +right and eventually I end up where I + + + align:start position:0% +right and eventually I end up where I +need to be okay so notice I used just in + + align:start position:0% +need to be okay so notice I used just in + + + align:start position:0% +need to be okay so notice I used just in +plain English a few keywords okay if + + align:start position:0% +plain English a few keywords okay if + + + align:start position:0% +plain English a few keywords okay if +otherwise things like that so in program + + align:start position:0% +otherwise things like that so in program + + + align:start position:0% +otherwise things like that so in program +in we have those same + + align:start position:0% +in we have those same + + + align:start position:0% +in we have those same +constructs and those same sort of + + align:start position:0% +constructs and those same sort of + + + align:start position:0% +constructs and those same sort of +intuitive words can be used to tell + + align:start position:0% +intuitive words can be used to tell + + + align:start position:0% +intuitive words can be used to tell +python to do something or to do + + align:start position:0% +python to do something or to do + + + align:start position:0% +python to do something or to do +something else or to choose from a + + align:start position:0% +something else or to choose from a + + + align:start position:0% +something else or to choose from a +different um set of possibilities + + align:start position:0% +different um set of possibilities + + + align:start position:0% +different um set of possibilities +okay and this way we can get the + + align:start position:0% +okay and this way we can get the + + + align:start position:0% +okay and this way we can get the +computer to make decisions for us now + + align:start position:0% +computer to make decisions for us now + + + align:start position:0% +computer to make decisions for us now +you might be thinking well you said that + + align:start position:0% +you might be thinking well you said that + + + align:start position:0% +you might be thinking well you said that +computers can't make decisions on their + + align:start position:0% +computers can't make decisions on their + + + align:start position:0% +computers can't make decisions on their +own it's not us programmers are going to + + align:start position:0% +own it's not us programmers are going to + + + align:start position:0% +own it's not us programmers are going to +build these decisions into the program + + align:start position:0% +build these decisions into the program + + + align:start position:0% +build these decisions into the program +and all the computer is going to do is + + align:start position:0% +and all the computer is going to do is + + + align:start position:0% +and all the computer is going to do is +going to say is going to reach the + + align:start position:0% +going to say is going to reach the + + + align:start position:0% +going to say is going to reach the +decision point and say okay this is a + + align:start position:0% +decision point and say okay this is a + + + align:start position:0% +decision point and say okay this is a +decision point should I go left or + + align:start position:0% +decision point should I go left or + + + align:start position:0% +decision point should I go left or +should I go right or which one do I pick + + align:start position:0% +should I go right or which one do I pick + + + align:start position:0% +should I go right or which one do I pick +and these sort of decisions are created + + align:start position:0% +and these sort of decisions are created + + + align:start position:0% +and these sort of decisions are created +by you as a programmer and the computer + + align:start position:0% +by you as a programmer and the computer + + + align:start position:0% +by you as a programmer and the computer +just has to make make the decision and + + align:start position:0% +just has to make make the decision and + + + align:start position:0% +just has to make make the decision and +choose a path okay so in programming + + align:start position:0% +choose a path okay so in programming + + + align:start position:0% +choose a path okay so in programming +there's three sort of simple ways that + + align:start position:0% +there's three sort of simple ways that + + + align:start position:0% +there's three sort of simple ways that +you can add um control flow to your + + align:start position:0% +you can add um control flow to your + + + align:start position:0% +you can add um control flow to your +programs and that's making one decision + + align:start position:0% +programs and that's making one decision + + + align:start position:0% +programs and that's making one decision +and choosing whether to execute + + align:start position:0% +and choosing whether to execute + + + align:start position:0% +and choosing whether to execute +something or execute something + + align:start position:0% +something or execute something + + + align:start position:0% +something or execute something +else the first is the simple if + + align:start position:0% +else the first is the simple if + + + align:start position:0% +else the first is the simple if +okay and given a program that just + + align:start position:0% +okay and given a program that just + + + align:start position:0% +okay and given a program that just +linearly has statements that get + + align:start position:0% +linearly has statements that get + + + align:start position:0% +linearly has statements that get +executed whenever I reach an if + + align:start position:0% +executed whenever I reach an if + + + align:start position:0% +executed whenever I reach an if +statement you're going to check the + + align:start position:0% +statement you're going to check the + + + align:start position:0% +statement you're going to check the +condition the condition is going to be + + align:start position:0% +condition the condition is going to be + + + align:start position:0% +condition the condition is going to be +something that's going to get evaluated + + align:start position:0% +something that's going to get evaluated + + + align:start position:0% +something that's going to get evaluated +to either true or + + align:start position:0% +to either true or + + + align:start position:0% +to either true or +false okay so I've reached the condition + + align:start position:0% +false okay so I've reached the condition + + + align:start position:0% +false okay so I've reached the condition +here and if the condition's true then + + align:start position:0% +here and if the condition's true then + + + align:start position:0% +here and if the condition's true then +I'm going to additionally execute this + + align:start position:0% +I'm going to additionally execute this + + + align:start position:0% +I'm going to additionally execute this +extra set of + + align:start position:0% +extra set of + + + align:start position:0% +extra set of +Expressions but if the condition's false + + align:start position:0% +Expressions but if the condition's false + + + align:start position:0% +Expressions but if the condition's false +then I'm just going to keep going + + align:start position:0% +then I'm just going to keep going + + + align:start position:0% +then I'm just going to keep going +through the program and not execute that + + align:start position:0% +through the program and not execute that + + + align:start position:0% +through the program and not execute that +extra set of instructions + + align:start position:0% +extra set of instructions + + + align:start position:0% +extra set of instructions +okay how does python know which + + align:start position:0% +okay how does python know which + + + align:start position:0% +okay how does python know which +instructions to execute they're going to + + align:start position:0% +instructions to execute they're going to + + + align:start position:0% +instructions to execute they're going to +be inside this what we call code + + align:start position:0% +be inside this what we call code + + + align:start position:0% +be inside this what we call code +block and the code block is denoted by + + align:start position:0% +block and the code block is denoted by + + + align:start position:0% +block and the code block is denoted by +indentation so it's going to be + + align:start position:0% +indentation so it's going to be + + + align:start position:0% +indentation so it's going to be +everything that's indented is part of + + align:start position:0% +everything that's indented is part of + + + align:start position:0% +everything that's indented is part of +that if code + + align:start position:0% +that if code + + + align:start position:0% +that if code +block typic typically four spaces of + + align:start position:0% +block typic typically four spaces of + + + align:start position:0% +block typic typically four spaces of +dentation okay so + + align:start position:0% +dentation okay so + + + align:start position:0% +dentation okay so +that's that's how you'd write code that + + align:start position:0% +that's that's how you'd write code that + + + align:start position:0% +that's that's how you'd write code that +decides whether to execute this extra + + align:start position:0% +decides whether to execute this extra + + + align:start position:0% +decides whether to execute this extra +thing or + + align:start position:0% +thing or + + + align:start position:0% +thing or +not now let's say I don't just want to + + align:start position:0% +not now let's say I don't just want to + + + align:start position:0% +not now let's say I don't just want to +execute an extra thing I want to reach a + + align:start position:0% +execute an extra thing I want to reach a + + + align:start position:0% +execute an extra thing I want to reach a +condition I want to reach a point where + + align:start position:0% +condition I want to reach a point where + + + align:start position:0% +condition I want to reach a point where +I say I'll either go down this path or + + align:start position:0% +I say I'll either go down this path or + + + align:start position:0% +I say I'll either go down this path or +I'll do something else okay + + align:start position:0% + + + + align:start position:0% + +that's this right + + align:start position:0% +that's this right + + + align:start position:0% +that's this right +here so this if + + align:start position:0% +here so this if + + + align:start position:0% +here so this if +else construct says this is my code I've + + align:start position:0% +else construct says this is my code I've + + + align:start position:0% +else construct says this is my code I've +reached my decision Point here if the + + align:start position:0% +reached my decision Point here if the + + + align:start position:0% +reached my decision Point here if the +condition inside this if is + + align:start position:0% +condition inside this if is + + + align:start position:0% +condition inside this if is +true then I'm going to execute maybe + + align:start position:0% +true then I'm going to execute maybe + + + align:start position:0% +true then I'm going to execute maybe +this set of statements + + align:start position:0% + + + + align:start position:0% + +here okay but if the condition is not + + align:start position:0% +here okay but if the condition is not + + + align:start position:0% +here okay but if the condition is not +true then I'm not going to execute that + + align:start position:0% +true then I'm not going to execute that + + + align:start position:0% +true then I'm not going to execute that +set of statements and instead I'm going + + align:start position:0% +set of statements and instead I'm going + + + align:start position:0% +set of statements and instead I'm going +to execute under whatever + + align:start position:0% +to execute under whatever + + + align:start position:0% +to execute under whatever +else + + align:start position:0% +else + + + align:start position:0% +else +is so using this construct I'm either + + align:start position:0% +is so using this construct I'm either + + + align:start position:0% +is so using this construct I'm either +going to do one set of expressions or + + align:start position:0% +going to do one set of expressions or + + + align:start position:0% +going to do one set of expressions or +the other but never both okay and after + + align:start position:0% +the other but never both okay and after + + + align:start position:0% +the other but never both okay and after +I've executed one or the other I'm going + + align:start position:0% +I've executed one or the other I'm going + + + align:start position:0% +I've executed one or the other I'm going +to continue on with just the regular + + align:start position:0% +to continue on with just the regular + + + align:start position:0% +to continue on with just the regular +execution of the + + align:start position:0% + + + + align:start position:0% + +program all + + align:start position:0% +program all + + + align:start position:0% +program all +right okay so we're able to either + + align:start position:0% +right okay so we're able to either + + + align:start position:0% +right okay so we're able to either +choose one thing choose one thing or + + align:start position:0% +choose one thing choose one thing or + + + align:start position:0% +choose one thing choose one thing or +another but what if we want to have uh + + align:start position:0% +another but what if we want to have uh + + + align:start position:0% +another but what if we want to have uh +more than one choice so + + align:start position:0% +more than one choice so + + + align:start position:0% +more than one choice so +if some number is equal to zero I want + + align:start position:0% +if some number is equal to zero I want + + + align:start position:0% +if some number is equal to zero I want +to do this if it's equal to one I want + + align:start position:0% +to do this if it's equal to one I want + + + align:start position:0% +to do this if it's equal to one I want +to do this otherwi if it's equal to two + + align:start position:0% +to do this otherwi if it's equal to two + + + align:start position:0% +to do this otherwi if it's equal to two +I want to do this and so on that's where + + align:start position:0% +I want to do this and so on that's where + + + align:start position:0% +I want to do this and so on that's where +this last one comes in and we introduce + + align:start position:0% +this last one comes in and we introduce + + + align:start position:0% +this last one comes in and we introduce +this + + align:start position:0% +this + + + align:start position:0% +this +other keyword here called L + + align:start position:0% +other keyword here called L + + + align:start position:0% +other keyword here called L +if so that stands for short form for + + align:start position:0% +if so that stands for short form for + + + align:start position:0% +if so that stands for short form for +else + + align:start position:0% +else + + + align:start position:0% +else +if so first we check if this condition + + align:start position:0% +if so first we check if this condition + + + align:start position:0% +if so first we check if this condition +is true so we're going through our + + align:start position:0% +is true so we're going through our + + + align:start position:0% +is true so we're going through our +program we've reached our decision point + + align:start position:0% +program we've reached our decision point + + + align:start position:0% +program we've reached our decision point +if the condition is true we're going to + + align:start position:0% +if the condition is true we're going to + + + align:start position:0% +if the condition is true we're going to +execute maybe this set of + + align:start position:0% + + + + align:start position:0% + +instructions if the condition is not + + align:start position:0% +instructions if the condition is not + + + align:start position:0% +instructions if the condition is not +true maybe we'll + + align:start position:0% +true maybe we'll + + + align:start position:0% +true maybe we'll +check if the condition is not true we + + align:start position:0% +check if the condition is not true we + + + align:start position:0% +check if the condition is not true we +will check this next condition that's + + align:start position:0% +will check this next condition that's + + + align:start position:0% +will check this next condition that's +part of the L if right here and if that + + align:start position:0% +part of the L if right here and if that + + + align:start position:0% +part of the L if right here and if that +one's true we're going to execute a + + align:start position:0% +one's true we're going to execute a + + + align:start position:0% +one's true we're going to execute a +different set of instructions you can + + align:start position:0% +different set of instructions you can + + + align:start position:0% +different set of instructions you can +have more than one L if and depending on + + align:start position:0% +have more than one L if and depending on + + + align:start position:0% +have more than one L if and depending on +which one's true you're going to execute + + align:start position:0% +which one's true you're going to execute + + + align:start position:0% +which one's true you're going to execute +a different set of + + align:start position:0% +a different set of + + + align:start position:0% +a different set of +instructions and then this last else is + + align:start position:0% +instructions and then this last else is + + + align:start position:0% +instructions and then this last else is +sort of a c all where if none of the + + align:start position:0% +sort of a c all where if none of the + + + align:start position:0% +sort of a c all where if none of the +previous conditions were true then just + + align:start position:0% +previous conditions were true then just + + + align:start position:0% +previous conditions were true then just +do this this last set of Expressions so + + align:start position:0% +do this this last set of Expressions so + + + align:start position:0% +do this this last set of Expressions so +in this case you're going to choose + + align:start position:0% +in this case you're going to choose + + + align:start position:0% +in this case you're going to choose +between one of these three one of these + + align:start position:0% +between one of these three one of these + + + align:start position:0% +between one of these three one of these +four roots or however many you + + align:start position:0% +four roots or however many you + + + align:start position:0% +four roots or however many you +have and then when you're done making + + align:start position:0% +have and then when you're done making + + + align:start position:0% +have and then when you're done making +your choice you're going to execute the + + align:start position:0% +your choice you're going to execute the + + + align:start position:0% +your choice you're going to execute the +remaining set of + + align:start position:0% + + + + align:start position:0% + +instructions so the way this works is if + + align:start position:0% +instructions so the way this works is if + + + align:start position:0% +instructions so the way this works is if +more than one condition is true you're + + align:start position:0% +more than one condition is true you're + + + align:start position:0% +more than one condition is true you're +actually just going to enter one of them + + align:start position:0% +actually just going to enter one of them + + + align:start position:0% +actually just going to enter one of them +and you're going to enter the very first + + align:start position:0% +and you're going to enter the very first + + + align:start position:0% +and you're going to enter the very first +one that's true so you're never going to + + align:start position:0% +one that's true so you're never going to + + + align:start position:0% +one that's true so you're never going to +enter more than one of these code blocks + + align:start position:0% +enter more than one of these code blocks + + + align:start position:0% +enter more than one of these code blocks +you're always enter one and you enter + + align:start position:0% +you're always enter one and you enter + + + align:start position:0% +you're always enter one and you enter +the very the first one that's that + + align:start position:0% +the very the first one that's that + + + align:start position:0% +the very the first one that's that +evaluates to + + align:start position:0% + + + + align:start position:0% + +true so notice that we denoted code + + align:start position:0% +true so notice that we denoted code + + + align:start position:0% +true so notice that we denoted code +blocks using indentation and that's + + align:start position:0% +blocks using indentation and that's + + + align:start position:0% +blocks using indentation and that's +actually one of the things that I really + + align:start position:0% +actually one of the things that I really + + + align:start position:0% +actually one of the things that I really +like about python it sort of forces you + + align:start position:0% +like about python it sort of forces you + + + align:start position:0% +like about python it sort of forces you +to write pretty code and nice looking + + align:start position:0% +to write pretty code and nice looking + + + align:start position:0% +to write pretty code and nice looking +code um and just code that's very + + align:start position:0% +code um and just code that's very + + + align:start position:0% +code um and just code that's very +readable um and that forces you to + + align:start position:0% +readable um and that forces you to + + + align:start position:0% +readable um and that forces you to +indent everything that's a code block + + align:start position:0% +indent everything that's a code block + + + align:start position:0% +indent everything that's a code block +okay so you can easily see sort of where + + align:start position:0% +okay so you can easily see sort of where + + + align:start position:0% +okay so you can easily see sort of where +the flow of control is and where + + align:start position:0% +the flow of control is and where + + + align:start position:0% +the flow of control is and where +decision- making points are and and + + align:start position:0% +decision- making points are and and + + + align:start position:0% +decision- making points are and and +things like + + align:start position:0% +things like + + + align:start position:0% +things like +that okay so in this particular example + + align:start position:0% +that okay so in this particular example + + + align:start position:0% +that okay so in this particular example +we have one if statement here and it + + align:start position:0% +we have one if statement here and it + + + align:start position:0% +we have one if statement here and it +checks if two variables are + + align:start position:0% + + + + align:start position:0% + +equal and we have an if L if else + + align:start position:0% +equal and we have an if L if else + + + align:start position:0% +equal and we have an if L if else +and in this example we're going to enter + + align:start position:0% +and in this example we're going to enter + + + align:start position:0% +and in this example we're going to enter +either this code block or this one or + + align:start position:0% +either this code block or this one or + + + align:start position:0% +either this code block or this one or +this one depending on the variables of X + + align:start position:0% +this one depending on the variables of X + + + align:start position:0% +this one depending on the variables of X +and Y and we're only going to enter one + + align:start position:0% +and Y and we're only going to enter one + + + align:start position:0% +and Y and we're only going to enter one +code block and we'll enter the first one + + align:start position:0% +code block and we'll enter the first one + + + align:start position:0% +code block and we'll enter the first one +that that's + + align:start position:0% +that that's + + + align:start position:0% +that that's +true notice you can have nested + + align:start position:0% +true notice you can have nested + + + align:start position:0% +true notice you can have nested +conditionals so inside this first if we + + align:start position:0% +conditionals so inside this first if we + + + align:start position:0% +conditionals so inside this first if we +have another if + + align:start position:0% + + + + align:start position:0% + +here and this inner if is only going to + + align:start position:0% +here and this inner if is only going to + + + align:start position:0% +here and this inner if is only going to +be checked when + + align:start position:0% +be checked when + + + align:start position:0% +be checked when +we enter the first this outer + + align:start position:0% +we enter the first this outer + + + align:start position:0% +we enter the first this outer +if + + align:start position:0% + + + + align:start position:0% + +okay I do want to make one point though + + align:start position:0% +okay I do want to make one point though + + + align:start position:0% +okay I do want to make one point though +so sometimes you might forget to do the + + align:start position:0% +so sometimes you might forget to do the + + + align:start position:0% +so sometimes you might forget to do the +double equal sign when you do when you + + align:start position:0% +double equal sign when you do when you + + + align:start position:0% +double equal sign when you do when you +check when you're checking for equality + + align:start position:0% +check when you're checking for equality + + + align:start position:0% +check when you're checking for equality +and that's okay if you just use one + + align:start position:0% +and that's okay if you just use one + + + align:start position:0% +and that's okay if you just use one +equal sign Python's going to give you an + + align:start position:0% +equal sign Python's going to give you an + + + align:start position:0% +equal sign Python's going to give you an +error and it's going to say syntax error + + align:start position:0% +error and it's going to say syntax error + + + align:start position:0% +error and it's going to say syntax error +and it's going to highlight this line + + align:start position:0% +and it's going to highlight this line + + + align:start position:0% +and it's going to highlight this line +and then you're going to know that + + align:start position:0% +and then you're going to know that + + + align:start position:0% +and then you're going to know that +there's there's a there's a mistake + + align:start position:0% +there's there's a there's a mistake + + + align:start position:0% +there's there's a there's a mistake +there you should be using equality + + align:start position:0% +there you should be using equality + + + align:start position:0% +there you should be using equality +because it doesn't make sense to be + + align:start position:0% +because it doesn't make sense to be + + + align:start position:0% +because it doesn't make sense to be +using to to assign to be making an + + align:start position:0% +using to to assign to be making an + + + align:start position:0% +using to to assign to be making an +assignment inside the + + align:start position:0% +assignment inside the + + + align:start position:0% +assignment inside the +if + + align:start position:0% + + + + align:start position:0% + +okay all + + align:start position:0% +okay all + + + align:start position:0% +okay all +right so we've learned about branching + + align:start position:0% +right so we've learned about branching + + + align:start position:0% +right so we've learned about branching +and we know about + + align:start position:0% +and we know about + + + align:start position:0% +and we know about +conditionals let's try to apply this + + align:start position:0% +conditionals let's try to apply this + + + align:start position:0% +conditionals let's try to apply this +to uh to a little + + align:start position:0% +to uh to a little + + + align:start position:0% +to uh to a little +game and spoiler we won't be able to + + align:start position:0% +game and spoiler we won't be able to + + + align:start position:0% +game and spoiler we won't be able to +we'll have to learn about a new thing + + align:start position:0% +we'll have to learn about a new thing + + + align:start position:0% +we'll have to learn about a new thing +but back 1980s there was The Legend of + + align:start position:0% +but back 1980s there was The Legend of + + + align:start position:0% +but back 1980s there was The Legend of +Zelda cool + + align:start position:0% +Zelda cool + + + align:start position:0% +Zelda cool +graphics um where there was a scene with + + align:start position:0% +graphics um where there was a scene with + + + align:start position:0% +graphics um where there was a scene with +the Lost Woods okay oversimplification + + align:start position:0% +the Lost Woods okay oversimplification + + + align:start position:0% +the Lost Woods okay oversimplification +if anyone's a Zelda know D die hard fan + + align:start position:0% +if anyone's a Zelda know D die hard fan + + + align:start position:0% +if anyone's a Zelda know D die hard fan +but the basic idea was if you entered + + align:start position:0% +but the basic idea was if you entered + + + align:start position:0% +but the basic idea was if you entered +the woods you know you entered from the + + align:start position:0% +the woods you know you entered from the + + + align:start position:0% +the woods you know you entered from the +left to the right and then as long as + + align:start position:0% +left to the right and then as long as + + + align:start position:0% +left to the right and then as long as +you kept going right it would show you + + align:start position:0% +you kept going right it would show you + + + align:start position:0% +you kept going right it would show you +the same screen over and over again okay + + align:start position:0% +the same screen over and over again okay + + + align:start position:0% +the same screen over and over again okay +and the trick was you just had to go + + align:start position:0% +and the trick was you just had to go + + + align:start position:0% +and the trick was you just had to go +backward and then you'd exit exit the + + align:start position:0% +backward and then you'd exit exit the + + + align:start position:0% +backward and then you'd exit exit the +wood + + align:start position:0% +wood + + + align:start position:0% +wood +okay so very simple using what we know + + align:start position:0% +okay so very simple using what we know + + + align:start position:0% +okay so very simple using what we know +so far we could sort of code this + + align:start position:0% +so far we could sort of code this + + + align:start position:0% +so far we could sort of code this +up and we'd say something like this if + + align:start position:0% +up and we'd say something like this if + + + align:start position:0% +up and we'd say something like this if +the user exits right then set the + + align:start position:0% +the user exits right then set the + + + align:start position:0% +the user exits right then set the +background to the woods + + align:start position:0% +background to the woods + + + align:start position:0% +background to the woods +background otherwise set the background + + align:start position:0% +background otherwise set the background + + + align:start position:0% +background otherwise set the background +to the exit + + align:start position:0% +to the exit + + + align:start position:0% +to the exit +background okay now let's say the user + + align:start position:0% +background okay now let's say the user + + + align:start position:0% +background okay now let's say the user +and then and then in the else we're done + + align:start position:0% +and then and then in the else we're done + + + align:start position:0% +and then and then in the else we're done +let's say the user went right well you'd + + align:start position:0% +let's say the user went right well you'd + + + align:start position:0% +let's say the user went right well you'd +show them the woods background and now + + align:start position:0% +show them the woods background and now + + + align:start position:0% +show them the woods background and now +ask them again where do they want to go + + align:start position:0% +ask them again where do they want to go + + + align:start position:0% +ask them again where do they want to go +if they exit right set the background to + + align:start position:0% +if they exit right set the background to + + + align:start position:0% +if they exit right set the background to +the woods backgr otherwise set the + + align:start position:0% +the woods backgr otherwise set the + + + align:start position:0% +the woods backgr otherwise set the +background to the exit background and so + + align:start position:0% +background to the exit background and so + + + align:start position:0% +background to the exit background and so +on so you notice that there's sort of no + + align:start position:0% +on so you notice that there's sort of no + + + align:start position:0% +on so you notice that there's sort of no +end to this right how many time do you + + align:start position:0% +end to this right how many time do you + + + align:start position:0% +end to this right how many time do you +know do you know how many times the user + + align:start position:0% +know do you know how many times the user + + + align:start position:0% +know do you know how many times the user +might keep going right they might be + + align:start position:0% +might keep going right they might be + + + align:start position:0% +might keep going right they might be +really persistent right and they'll be + + align:start position:0% +really persistent right and they'll be + + + align:start position:0% +really persistent right and they'll be +like maybe maybe if I go a thousand + + align:start position:0% +like maybe maybe if I go a thousand + + + align:start position:0% +like maybe maybe if I go a thousand +times I'll get out of the woods you know + + align:start position:0% +times I'll get out of the woods you know + + + align:start position:0% +times I'll get out of the woods you know +or maybe a thousand one maybe so + + align:start position:0% +or maybe a thousand one maybe so + + + align:start position:0% +or maybe a thousand one maybe so +this this would probably be who knows + + align:start position:0% +this this would probably be who knows + + + align:start position:0% +this this would probably be who knows +how how deep this this nested these + + align:start position:0% +how how deep this this nested these + + + align:start position:0% +how how deep this this nested these +nested ifs okay okay so we don't + + align:start position:0% +nested ifs okay okay so we don't + + + align:start position:0% +nested ifs okay okay so we don't +know so with what we know so far we + + align:start position:0% +know so with what we know so far we + + + align:start position:0% +know so with what we know so far we +can't really code this this cute little + + align:start position:0% +can't really code this this cute little + + + align:start position:0% +can't really code this this cute little +game but enter loops and specifically a + + align:start position:0% +game but enter loops and specifically a + + + align:start position:0% +game but enter loops and specifically a +while + + align:start position:0% +while + + + align:start position:0% +while +loop so this code here that could be you + + align:start position:0% +loop so this code here that could be you + + + align:start position:0% +loop so this code here that could be you +know infinitely number of nested if + + align:start position:0% +know infinitely number of nested if + + + align:start position:0% +know infinitely number of nested if +statements deep can be Rewritten using + + align:start position:0% +statements deep can be Rewritten using + + + align:start position:0% +statements deep can be Rewritten using +these three + + align:start position:0% +these three + + + align:start position:0% +these three +lines so we say while the user exits + + align:start position:0% +lines so we say while the user exits + + + align:start position:0% +lines so we say while the user exits +right set the background to the woods + + align:start position:0% +right set the background to the woods + + + align:start position:0% +right set the background to the woods +background and with a while loop it's + + align:start position:0% +background and with a while loop it's + + + align:start position:0% +background and with a while loop it's +going to do what we tell it to do inside + + align:start position:0% +going to do what we tell it to do inside + + + align:start position:0% +going to do what we tell it to do inside +the loop and then it's going to check + + align:start position:0% +the loop and then it's going to check + + + align:start position:0% +the loop and then it's going to check +the condition again and then it's going + + align:start position:0% +the condition again and then it's going + + + align:start position:0% +the condition again and then it's going +to do what we what we say it should do + + align:start position:0% +to do what we what we say it should do + + + align:start position:0% +to do what we what we say it should do +inside the code block and then it's + + align:start position:0% +inside the code block and then it's + + + align:start position:0% +inside the code block and then it's +going to set the check the condition + + align:start position:0% +going to set the check the condition + + + align:start position:0% +going to set the check the condition +again and then when the condition as + + align:start position:0% +again and then when the condition as + + + align:start position:0% +again and then when the condition as +long as the condition is true it's going + + align:start position:0% +long as the condition is true it's going + + + align:start position:0% +long as the condition is true it's going +to keep doing that little Loop there and + + align:start position:0% +to keep doing that little Loop there and + + + align:start position:0% +to keep doing that little Loop there and +as soon as the condition becomes false + + align:start position:0% +as soon as the condition becomes false + + + align:start position:0% +as soon as the condition becomes false +it's going to stop doing the loop and do + + align:start position:0% +it's going to stop doing the loop and do + + + align:start position:0% +it's going to stop doing the loop and do +whatever is right after the + + align:start position:0% +whatever is right after the + + + align:start position:0% +whatever is right after the +while okay so that's basically how a + + align:start position:0% +while okay so that's basically how a + + + align:start position:0% +while okay so that's basically how a +while loop works we have while that's + + align:start position:0% +while loop works we have while that's + + + align:start position:0% +while loop works we have while that's +the keyword the condition is something + + align:start position:0% +the keyword the condition is something + + + align:start position:0% +the keyword the condition is something +that gets evaluated to true or false and + + align:start position:0% +that gets evaluated to true or false and + + + align:start position:0% +that gets evaluated to true or false and +once again we have a code block that's + + align:start position:0% +once again we have a code block that's + + + align:start position:0% +once again we have a code block that's +indented and it tells python these are + + align:start position:0% +indented and it tells python these are + + + align:start position:0% +indented and it tells python these are +the Expressions I want to do as long as + + align:start position:0% +the Expressions I want to do as long as + + + align:start position:0% +the Expressions I want to do as long as +the condition is + + align:start position:0% + + + + align:start position:0% + +true so the condition is true you + + align:start position:0% +true so the condition is true you + + + align:start position:0% +true so the condition is true you +evaluate every expression in the code + + align:start position:0% +evaluate every expression in the code + + + align:start position:0% +evaluate every expression in the code +block when you reach the end of the + + align:start position:0% +block when you reach the end of the + + + align:start position:0% +block when you reach the end of the +expression end of the code block you + + align:start position:0% +expression end of the code block you + + + align:start position:0% +expression end of the code block you +check the condition again if it's true + + align:start position:0% +check the condition again if it's true + + + align:start position:0% +check the condition again if it's true +still you keep doing the Expressions + + align:start position:0% +still you keep doing the Expressions + + + align:start position:0% +still you keep doing the Expressions +check again and so + + align:start position:0% + + + + align:start position:0% + +on so here's a little + + align:start position:0% +on so here's a little + + + align:start position:0% +on so here's a little +game and with these lines of code we + + align:start position:0% +game and with these lines of code we + + + align:start position:0% +game and with these lines of code we +were able you know we can code up the + + align:start position:0% +were able you know we can code up the + + + align:start position:0% +were able you know we can code up the +the Lost lwoods of uh of Zelda even + + align:start position:0% +the Lost lwoods of uh of Zelda even + + + align:start position:0% +the Lost lwoods of uh of Zelda even +worse Graphics by the way than the + + align:start position:0% +worse Graphics by the way than the + + + align:start position:0% +worse Graphics by the way than the +original Zelda is this one that I coated + + align:start position:0% +original Zelda is this one that I coated + + + align:start position:0% +original Zelda is this one that I coated +up here so I print out the following + + align:start position:0% +up here so I print out the following + + + align:start position:0% +up here so I print out the following +things you're in the L Forest go left or + + align:start position:0% +things you're in the L Forest go left or + + + align:start position:0% +things you're in the L Forest go left or +right and my program is going to say you + + align:start position:0% +right and my program is going to say you + + + align:start position:0% +right and my program is going to say you +know you're in the lost forest go left + + align:start position:0% +know you're in the lost forest go left + + + align:start position:0% +know you're in the lost forest go left +left or right it's going to get user + + align:start position:0% +left or right it's going to get user + + + align:start position:0% +left or right it's going to get user +input it's going to say while the user + + align:start position:0% +input it's going to say while the user + + + align:start position:0% +input it's going to say while the user +keeps typing in right show them this + + align:start position:0% +keeps typing in right show them this + + + align:start position:0% +keeps typing in right show them this +text and ask them again right so I'm + + align:start position:0% +text and ask them again right so I'm + + + align:start position:0% +text and ask them again right so I'm +asking them again by just saying input + + align:start position:0% +asking them again by just saying input + + + align:start position:0% +asking them again by just saying input +here + + align:start position:0% +here + + + align:start position:0% +here +again and that's it that's going to just + + align:start position:0% +again and that's it that's going to just + + + align:start position:0% +again and that's it that's going to just +keep getting input from the user and if + + align:start position:0% +keep getting input from the user and if + + + align:start position:0% +keep getting input from the user and if +the user doesn't type in right and maybe + + align:start position:0% +the user doesn't type in right and maybe + + + align:start position:0% +the user doesn't type in right and maybe +types in left you're going to exit out + + align:start position:0% +types in left you're going to exit out + + + align:start position:0% +types in left you're going to exit out +of this Loop and print out you got out + + align:start position:0% +of this Loop and print out you got out + + + align:start position:0% +of this Loop and print out you got out +of the last + + align:start position:0% +of the last + + + align:start position:0% +of the last +Force so I have to show you this because + + align:start position:0% +Force so I have to show you this because + + + align:start position:0% +Force so I have to show you this because +I spent + + align:start position:0% +I spent + + + align:start position:0% +I spent +too much time on + + align:start position:0% +too much time on + + + align:start position:0% +too much time on +it but I decided + + align:start position:0% +it but I decided + + + align:start position:0% +it but I decided +to improve on the code that's in the + + align:start position:0% +to improve on the code that's in the + + + align:start position:0% +to improve on the code that's in the +slides and I've written here ways that + + align:start position:0% +slides and I've written here ways that + + + align:start position:0% +slides and I've written here ways that +you guys can also improve it so if I run + + align:start position:0% +you guys can also improve it so if I run + + + align:start position:0% +you guys can also improve it so if I run +my code you you're in the lost forest go + + align:start position:0% +my code you you're in the lost forest go + + + align:start position:0% +my code you you're in the lost forest go +left or right so if I say left then yay + + align:start position:0% +left or right so if I say left then yay + + + align:start position:0% +left or right so if I say left then yay +I got out of the lost + + align:start position:0% +I got out of the lost + + + align:start position:0% +I got out of the lost +forest but if I go right then I'm stuck + + align:start position:0% +forest but if I go right then I'm stuck + + + align:start position:0% +forest but if I go right then I'm stuck +right I took down some trees you can see + + align:start position:0% +right I took down some trees you can see + + + align:start position:0% +right I took down some trees you can see +there's no more trees here I made a + + align:start position:0% +there's no more trees here I made a + + + align:start position:0% +there's no more trees here I made a +table and then I flipped it + + align:start position:0% +table and then I flipped it + + + align:start position:0% +table and then I flipped it +over + + align:start position:0% +over + + + align:start position:0% +over +okay so the expansion to this if you + + align:start position:0% +okay so the expansion to this if you + + + align:start position:0% +okay so the expansion to this if you +want to try it out I I put this in the + + align:start position:0% +want to try it out I I put this in the + + + align:start position:0% +want to try it out I I put this in the +comments here is try to use a counter + + align:start position:0% +comments here is try to use a counter + + + align:start position:0% +comments here is try to use a counter +okay if the user types in write the + + align:start position:0% +okay if the user types in write the + + + align:start position:0% +okay if the user types in write the +first two times just make that a sad + + align:start position:0% +first two times just make that a sad + + + align:start position:0% +first two times just make that a sad +face but if the user types in more than + + align:start position:0% +face but if the user types in more than + + + align:start position:0% +face but if the user types in more than +two times make them cut down some trees + + align:start position:0% +two times make them cut down some trees + + + align:start position:0% +two times make them cut down some trees +and build a table and flip it + + align:start position:0% +and build a table and flip it + + + align:start position:0% +and build a table and flip it +okay that's a cute little expansion if + + align:start position:0% +okay that's a cute little expansion if + + + align:start position:0% +okay that's a cute little expansion if +you want to test yourself to make sure + + align:start position:0% +you want to test yourself to make sure + + + align:start position:0% +you want to test yourself to make sure +you you're getting Loops + + align:start position:0% +you you're getting Loops + + + align:start position:0% +you you're getting Loops +okay so so far we've used while Loops to + + align:start position:0% +okay so so far we've used while Loops to + + + align:start position:0% +okay so so far we've used while Loops to +ask for user input and that's actually + + align:start position:0% +ask for user input and that's actually + + + align:start position:0% +ask for user input and that's actually +somewhere where it makes sense to use + + align:start position:0% +somewhere where it makes sense to use + + + align:start position:0% +somewhere where it makes sense to use +while Loops because you don't actually + + align:start position:0% +while Loops because you don't actually + + + align:start position:0% +while Loops because you don't actually +know how many times the user is going to + + align:start position:0% +know how many times the user is going to + + + align:start position:0% +know how many times the user is going to +type in + + align:start position:0% +type in + + + align:start position:0% +type in +something you can use y Loops to keep + + align:start position:0% +something you can use y Loops to keep + + + align:start position:0% +something you can use y Loops to keep +sort of a counter and to write code that + + align:start position:0% +sort of a counter and to write code that + + + align:start position:0% +sort of a counter and to write code that +counts + + align:start position:0% + + + + align:start position:0% + +something if you do that though there's + + align:start position:0% +something if you do that though there's + + + align:start position:0% +something if you do that though there's +two there's two things you need to take + + align:start position:0% +two there's two things you need to take + + + align:start position:0% +two there's two things you need to take +care of the first is this first line + + align:start position:0% +care of the first is this first line + + + align:start position:0% +care of the first is this first line +here which is sort of an initialization + + align:start position:0% +here which is sort of an initialization + + + align:start position:0% +here which is sort of an initialization +of this Loop + + align:start position:0% +of this Loop + + + align:start position:0% +of this Loop +counter and the second is this line here + + align:start position:0% +counter and the second is this line here + + + align:start position:0% +counter and the second is this line here +which is incrementing your Loop + + align:start position:0% + + + + align:start position:0% + +counter the reason why the second one's + + align:start position:0% +counter the reason why the second one's + + + align:start position:0% +counter the reason why the second one's +important is because let's look at our + + align:start position:0% +important is because let's look at our + + + align:start position:0% +important is because let's look at our +condition here so while n is less than + + align:start position:0% +condition here so while n is less than + + + align:start position:0% +condition here so while n is less than +five if you didn't have this line here + + align:start position:0% +five if you didn't have this line here + + + align:start position:0% +five if you didn't have this line here +you never increment n so every time + + align:start position:0% +you never increment n so every time + + + align:start position:0% +you never increment n so every time +through the loop you just keep printing + + align:start position:0% +through the loop you just keep printing + + + align:start position:0% +through the loop you just keep printing +zeros okay and you'd have an infinite + + align:start position:0% +zeros okay and you'd have an infinite + + + align:start position:0% +zeros okay and you'd have an infinite +loop I do want to show though what if + + align:start position:0% +loop I do want to show though what if + + + align:start position:0% +loop I do want to show though what if +you do have an infinite loop it's not + + align:start position:0% +you do have an infinite loop it's not + + + align:start position:0% +you do have an infinite loop it's not +the end of the world so I can say + + align:start position:0% +the end of the world so I can say + + + align:start position:0% +the end of the world so I can say +something + + align:start position:0% +something + + + align:start position:0% +something +like uh + + align:start position:0% +like uh + + + align:start position:0% +like uh +okay so while + + align:start position:0% +okay so while + + + align:start position:0% +okay so while +true + + align:start position:0% +true + + + align:start position:0% +true +print zero okay so this is going to give + + align:start position:0% +print zero okay so this is going to give + + + align:start position:0% +print zero okay so this is going to give +me an infinite Loop in my + + align:start position:0% +me an infinite Loop in my + + + align:start position:0% +me an infinite Loop in my +program + + align:start position:0% + + + + align:start position:0% + +and okay so notice it's just printing + + align:start position:0% +and okay so notice it's just printing + + + align:start position:0% +and okay so notice it's just printing +the letter P over and over again and if + + align:start position:0% +the letter P over and over again and if + + + align:start position:0% +the letter P over and over again and if +I let it go any longer it's going to + + align:start position:0% +I let it go any longer it's going to + + + align:start position:0% +I let it go any longer it's going to +slow down the computer so I'm going to + + align:start position:0% +slow down the computer so I'm going to + + + align:start position:0% +slow down the computer so I'm going to +hit control C or command C maybe and + + align:start position:0% +hit control C or command C maybe and + + + align:start position:0% +hit control C or command C maybe and +it's going to stop the program from + + align:start position:0% +it's going to stop the program from + + + align:start position:0% +it's going to stop the program from +printing okay so just in case you ever + + align:start position:0% +printing okay so just in case you ever + + + align:start position:0% +printing okay so just in case you ever +enter infinite Loops in your programs + + align:start position:0% +enter infinite Loops in your programs + + + align:start position:0% +enter infinite Loops in your programs +just go to the console and hit contrl C + + align:start position:0% +just go to the console and hit contrl C + + + align:start position:0% +just go to the console and hit contrl C +and that's going to stop it from sort of + + align:start position:0% +and that's going to stop it from sort of + + + align:start position:0% +and that's going to stop it from sort of +slowing down the + + align:start position:0% +slowing down the + + + align:start position:0% +slowing down the +computer okay so going back to this + + align:start position:0% +computer okay so going back to this + + + align:start position:0% +computer okay so going back to this +example I was saying that if you're + + align:start position:0% +example I was saying that if you're + + + align:start position:0% +example I was saying that if you're +using counters or variables in order to + + align:start position:0% +using counters or variables in order to + + + align:start position:0% +using counters or variables in order to +sort of count up inside the Y Loop you + + align:start position:0% +sort of count up inside the Y Loop you + + + align:start position:0% +sort of count up inside the Y Loop you +have to take care to initialize a count + + align:start position:0% +have to take care to initialize a count + + + align:start position:0% +have to take care to initialize a count +counter variable first and then to + + align:start position:0% +counter variable first and then to + + + align:start position:0% +counter variable first and then to +increment it otherwise you'll enter an + + align:start position:0% +increment it otherwise you'll enter an + + + align:start position:0% +increment it otherwise you'll enter an +infinite + + align:start position:0% +infinite + + + align:start position:0% +infinite +Loop that feels a little bit tedious and + + align:start position:0% +Loop that feels a little bit tedious and + + + align:start position:0% +Loop that feels a little bit tedious and +so there's a + + align:start position:0% +so there's a + + + align:start position:0% +so there's a +shortcut for doing that EX exact same + + align:start position:0% +shortcut for doing that EX exact same + + + align:start position:0% +shortcut for doing that EX exact same +thing so these four lines you can + + align:start position:0% +thing so these four lines you can + + + align:start position:0% +thing so these four lines you can +rewrite those into these two lines right + + align:start position:0% +rewrite those into these two lines right + + + align:start position:0% +rewrite those into these two lines right +here using this new type of loop called + + align:start position:0% +here using this new type of loop called + + + align:start position:0% +here using this new type of loop called +a four + + align:start position:0% +a four + + + align:start position:0% +a four +Loop so the for Loop says for some Loop + + align:start position:0% +Loop so the for Loop says for some Loop + + + align:start position:0% +Loop so the for Loop says for some Loop +variable in this case I named it n you + + align:start position:0% +variable in this case I named it n you + + + align:start position:0% +variable in this case I named it n you +can name it whatever you want in range + + align:start position:0% +can name it whatever you want in range + + + align:start position:0% +can name it whatever you want in range +five we're going to come back to what + + align:start position:0% +five we're going to come back to what + + + align:start position:0% +five we're going to come back to what +range means in a little bit print + + align:start position:0% +range means in a little bit print + + + align:start position:0% +range means in a little bit print +n + + align:start position:0% +n + + + align:start position:0% +n +okay so every time through the loop + + align:start position:0% +okay so every time through the loop + + + align:start position:0% +okay so every time through the loop +you're going to print out what the value + + align:start position:0% +you're going to print out what the value + + + align:start position:0% +you're going to print out what the value +of n + + align:start position:0% +of n + + + align:start position:0% +of n +is range five + + align:start position:0% +is range five + + + align:start position:0% +is range five +actually creates internally a sequence + + align:start position:0% +actually creates internally a sequence + + + align:start position:0% +actually creates internally a sequence +of numbers starting from zero and going + + align:start position:0% +of numbers starting from zero and going + + + align:start position:0% +of numbers starting from zero and going +to that number 5 - one so the sequence + + align:start position:0% +to that number 5 - one so the sequence + + + align:start position:0% +to that number 5 - one so the sequence +is going to be 0 1 2 3 and + + align:start position:0% +is going to be 0 1 2 3 and + + + align:start position:0% +is going to be 0 1 2 3 and +four the first time through the loop + + align:start position:0% +four the first time through the loop + + + align:start position:0% +four the first time through the loop +you're going to say n is equal to zero + + align:start position:0% +you're going to say n is equal to zero + + + align:start position:0% +you're going to say n is equal to zero +or internally this is what happens n + + align:start position:0% +or internally this is what happens n + + + align:start position:0% +or internally this is what happens n +gets the value zero you're going to + + align:start position:0% +gets the value zero you're going to + + + align:start position:0% +gets the value zero you're going to +print + + align:start position:0% +print + + + align:start position:0% +print +n then you're going to back go back to + + align:start position:0% +n then you're going to back go back to + + + align:start position:0% +n then you're going to back go back to +the to the top n gets the value one then + + align:start position:0% +the to the top n gets the value one then + + + align:start position:0% +the to the top n gets the value one then +you're going to go execute whatever + + align:start position:0% +you're going to go execute whatever + + + align:start position:0% +you're going to go execute whatever +inside so you're going to print + + align:start position:0% +inside so you're going to print + + + align:start position:0% +inside so you're going to print +one then you're going to increment that + + align:start position:0% +one then you're going to increment that + + + align:start position:0% +one then you're going to increment that +to the next value in the sequence you're + + align:start position:0% +to the next value in the sequence you're + + + align:start position:0% +to the next value in the sequence you're +going to print out two and so + + align:start position:0% +going to print out two and so + + + align:start position:0% +going to print out two and so +on so this is the + + align:start position:0% +on so this is the + + + align:start position:0% +on so this is the +general um look of a for Loop so we have + + align:start position:0% +general um look of a for Loop so we have + + + align:start position:0% +general um look of a for Loop so we have +four some uh loop variable again can be + + align:start position:0% +four some uh loop variable again can be + + + align:start position:0% +four some uh loop variable again can be +named whatever you want in range some + + align:start position:0% +named whatever you want in range some + + + align:start position:0% +named whatever you want in range some +number do a bunch of + + align:start position:0% +number do a bunch of + + + align:start position:0% +number do a bunch of +stuff and again these are part of this + + align:start position:0% +stuff and again these are part of this + + + align:start position:0% +stuff and again these are part of this +four Loop code block so you should + + align:start position:0% +four Loop code block so you should + + + align:start position:0% +four Loop code block so you should +indent them to tell python that these + + align:start position:0% +indent them to tell python that these + + + align:start position:0% +indent them to tell python that these +are the things that you should do okay + + align:start position:0% +are the things that you should do okay + + + align:start position:0% +are the things that you should do okay +so when you're using range some number + + align:start position:0% +so when you're using range some number + + + align:start position:0% +so when you're using range some number +you start + + align:start position:0% +you start + + + align:start position:0% +you start +out with variable getting the value + + align:start position:0% +out with variable getting the value + + + align:start position:0% +out with variable getting the value +zero okay with with variable having + + align:start position:0% +zero okay with with variable having + + + align:start position:0% +zero okay with with variable having +value zero you're going to execute all + + align:start position:0% +value zero you're going to execute all + + + align:start position:0% +value zero you're going to execute all +of these + + align:start position:0% +of these + + + align:start position:0% +of these +Expressions after all the expressions in + + align:start position:0% +Expressions after all the expressions in + + + align:start position:0% +Expressions after all the expressions in +the code block are done you're going to + + align:start position:0% +the code block are done you're going to + + + align:start position:0% +the code block are done you're going to +go on to the next value so + + align:start position:0% +go on to the next value so + + + align:start position:0% +go on to the next value so +one you're going to execute all these + + align:start position:0% +one you're going to execute all these + + + align:start position:0% +one you're going to execute all these +expressions with the variable being + + align:start position:0% +expressions with the variable being + + + align:start position:0% +expressions with the variable being +value one and then so on and so on until + + align:start position:0% +value one and then so on and so on until + + + align:start position:0% +value one and then so on and so on until +you go to Su num minus + + align:start position:0% + + + + align:start position:0% + +one that it so so using range in that + + align:start position:0% +one that it so so using range in that + + + align:start position:0% +one that it so so using range in that +way is a little bit con constraining + + align:start position:0% +way is a little bit con constraining + + + align:start position:0% +way is a little bit con constraining +because you're always going to get + + align:start position:0% +because you're always going to get + + + align:start position:0% +because you're always going to get +values starting from zero and ending at + + align:start position:0% +values starting from zero and ending at + + + align:start position:0% +values starting from zero and ending at +some num minus one okay whatever is in + + align:start position:0% +some num minus one okay whatever is in + + + align:start position:0% +some num minus one okay whatever is in +in the parentheses and range sometimes + + align:start position:0% +in the parentheses and range sometimes + + + align:start position:0% +in the parentheses and range sometimes +you might want to write programs that + + align:start position:0% +you might want to write programs that + + + align:start position:0% +you might want to write programs that +maybe start at a custom some value don't + + align:start position:0% +maybe start at a custom some value don't + + + align:start position:0% +maybe start at a custom some value don't +start at zero maybe they start at five + + align:start position:0% +start at zero maybe they start at five + + + align:start position:0% +start at zero maybe they start at five +maybe they start at minus + + align:start position:0% +maybe they start at minus + + + align:start position:0% +maybe they start at minus +10 and sometimes you might want to write + + align:start position:0% +10 and sometimes you might want to write + + + align:start position:0% +10 and sometimes you might want to write +programs that don't go with uh don't + + align:start position:0% +programs that don't go with uh don't + + + align:start position:0% +programs that don't go with uh don't +increment the numbers by one but maybe + + align:start position:0% +increment the numbers by one but maybe + + + align:start position:0% +increment the numbers by one but maybe +skip every other number or go every two + + align:start position:0% +skip every other number or go every two + + + align:start position:0% +skip every other number or go every two +numbers every three numbers and so on so + + align:start position:0% +numbers every three numbers and so on so + + + align:start position:0% +numbers every three numbers and so on so +you can customize range to your + + align:start position:0% +you can customize range to your + + + align:start position:0% +you can customize range to your +needs the one thing you do need to give + + align:start position:0% +needs the one thing you do need to give + + + align:start position:0% +needs the one thing you do need to give +it is this stop so if you give it only + + align:start position:0% +it is this stop so if you give it only + + + align:start position:0% +it is this stop so if you give it only +one value in the parenthesis that stands + + align:start position:0% +one value in the parenthesis that stands + + + align:start position:0% +one value in the parenthesis that stands +for stop and by default start is going + + align:start position:0% +for stop and by default start is going + + + align:start position:0% +for stop and by default start is going +to have value zero and step is going to + + align:start position:0% +to have value zero and step is going to + + + align:start position:0% +to have value zero and step is going to +have the value + + align:start position:0% +have the value + + + align:start position:0% +have the value +one if you give it two things in the + + align:start position:0% +one if you give it two things in the + + + align:start position:0% +one if you give it two things in the +parentheses you're giving it start and + + align:start position:0% +parentheses you're giving it start and + + + align:start position:0% +parentheses you're giving it start and +stop so the first being start the second + + align:start position:0% +stop so the first being start the second + + + align:start position:0% +stop so the first being start the second +being stop and step gets this value of + + align:start position:0% +being stop and step gets this value of + + + align:start position:0% +being stop and step gets this value of +one by default and if you give it three + + align:start position:0% +one by default and if you give it three + + + align:start position:0% +one by default and if you give it three +things in the parentheses you're giving + + align:start position:0% +things in the parentheses you're giving + + + align:start position:0% +things in the parentheses you're giving +it start stop and step in that + + align:start position:0% + + + + align:start position:0% + +order and you're always going to start + + align:start position:0% +order and you're always going to start + + + align:start position:0% +order and you're always going to start +at the start value and stop + + align:start position:0% +at the start value and stop + + + align:start position:0% +at the start value and stop +at or so you're going to start at the + + align:start position:0% +at or so you're going to start at the + + + align:start position:0% +at or so you're going to start at the +start value and you're going to go until + + align:start position:0% +start value and you're going to go until + + + align:start position:0% +start value and you're going to go until +stop minus one so those are the the + + align:start position:0% +stop minus one so those are the the + + + align:start position:0% +stop minus one so those are the the +sequences of + + align:start position:0% +sequences of + + + align:start position:0% +sequences of +numbers so in this first code right here + + align:start position:0% +numbers so in this first code right here + + + align:start position:0% +numbers so in this first code right here +my sum is going to get the value zero + + align:start position:0% +my sum is going to get the value zero + + + align:start position:0% +my sum is going to get the value zero +and you're going to have a for + + align:start position:0% +and you're going to have a for + + + align:start position:0% +and you're going to have a for +loop we're going to start from Seven + + align:start position:0% +loop we're going to start from Seven + + + align:start position:0% +loop we're going to start from Seven +right because we're giving it two + + align:start position:0% +right because we're giving it two + + + align:start position:0% +right because we're giving it two +numbers and when you give it two numbers + + align:start position:0% +numbers and when you give it two numbers + + + align:start position:0% +numbers and when you give it two numbers +it represents start and stop with step + + align:start position:0% +it represents start and stop with step + + + align:start position:0% +it represents start and stop with step +being one so you're starting at seven if + + align:start position:0% +being one so you're starting at seven if + + + align:start position:0% +being one so you're starting at seven if +step is one the next value is + + align:start position:0% +step is one the next value is + + + align:start position:0% +step is one the next value is +eight what's the value after + + align:start position:0% + + + + align:start position:0% + +that if we're incrementing by + + align:start position:0% + + + + align:start position:0% + +one + + align:start position:0% + + + + align:start position:0% + +nine and since we're going until stop + + align:start position:0% +nine and since we're going until stop + + + align:start position:0% +nine and since we're going until stop +minus + + align:start position:0% +minus + + + align:start position:0% +minus +one we're not actually going to pick up + + align:start position:0% +one we're not actually going to pick up + + + align:start position:0% +one we're not actually going to pick up +on + + align:start position:0% +on + + + align:start position:0% +on +10 okay so this Loop variable I the very + + align:start position:0% +10 okay so this Loop variable I the very + + + align:start position:0% +10 okay so this Loop variable I the very +first time through the loop is going to + + align:start position:0% +first time through the loop is going to + + + align:start position:0% +first time through the loop is going to +have the value seven + + align:start position:0% + + + + align:start position:0% + +so my sum is going to be 0 + + + align:start position:0% + + + + align:start position:0% + +7 that's everything that's inside the + + align:start position:0% +7 that's everything that's inside the + + + align:start position:0% +7 that's everything that's inside the +code + + align:start position:0% +code + + + align:start position:0% +code +block the next time through the loop I + + align:start position:0% +block the next time through the loop I + + + align:start position:0% +block the next time through the loop I +gets the value + + align:start position:0% +gets the value + + + align:start position:0% +gets the value +eight so + + align:start position:0% + + + + align:start position:0% + +inside inside the for Loop my sum gets + + align:start position:0% +inside inside the for Loop my sum gets + + + align:start position:0% +inside inside the for Loop my sum gets +whatever the previous value was which + + align:start position:0% +whatever the previous value was which + + + align:start position:0% +whatever the previous value was which +was 7 + 8 + + align:start position:0% + + + + align:start position:0% + +okay the next time through the loop my + + align:start position:0% +okay the next time through the loop my + + + align:start position:0% +okay the next time through the loop my +sum gets the value 7 + 8 + 9 obviously + + align:start position:0% +sum gets the value 7 + 8 + 9 obviously + + + align:start position:0% +sum gets the value 7 + 8 + 9 obviously +replacing that with the previous value + + align:start position:0% +replacing that with the previous value + + + align:start position:0% +replacing that with the previous value +so + + align:start position:0% +so + + + align:start position:0% +so +15 okay since we're not going through 10 + + align:start position:0% +15 okay since we're not going through 10 + + + align:start position:0% +15 okay since we're not going through 10 +that's where we stop and we're going to + + align:start position:0% +that's where we stop and we're going to + + + align:start position:0% +that's where we stop and we're going to +print out my sum which is going to be + + align:start position:0% +print out my sum which is going to be + + + align:start position:0% +print out my sum which is going to be +the value of 7 + 8 + + + align:start position:0% +the value of 7 + 8 + + + + align:start position:0% +the value of 7 + 8 + +9 oh + + align:start position:0% +9 oh + + + align:start position:0% +9 oh +yeah oh okay yeah start + + align:start position:0% +yeah oh okay yeah start + + + align:start position:0% +yeah oh okay yeah start +do they have to be integers + + align:start position:0% +do they have to be integers + + + align:start position:0% +do they have to be integers +um that's a great question we can try + + align:start position:0% +um that's a great question we can try + + + align:start position:0% +um that's a great question we can try +that out I'm not actually sure right off + + align:start position:0% +that out I'm not actually sure right off + + + align:start position:0% +that out I'm not actually sure right off +just off the top of my head so you can + + align:start position:0% +just off the top of my head so you can + + + align:start position:0% +just off the top of my head so you can +go in spider and + + align:start position:0% +go in spider and + + + align:start position:0% +go in spider and +say + + align:start position:0% +say + + + align:start position:0% +say +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +um let's say in this example here in + + align:start position:0% +um let's say in this example here in + + + align:start position:0% +um let's say in this example here in +this example + + align:start position:0% + + + + align:start position:0% + +here so we can say 7.1 + + align:start position:0% +here so we can say 7.1 + + + align:start position:0% +here so we can say 7.1 +10.3 + + align:start position:0% + + + + align:start position:0% + +yeah so they have to be + + align:start position:0% + + + + align:start position:0% + +integers okay so that's that's that + + align:start position:0% +integers okay so that's that's that + + + align:start position:0% +integers okay so that's that's that +example and let's erase that in this + + align:start position:0% +example and let's erase that in this + + + align:start position:0% +example and let's erase that in this +particular example we have start stop + + align:start position:0% +particular example we have start stop + + + align:start position:0% +particular example we have start stop +and step and here we're going going + + align:start position:0% +and step and here we're going going + + + align:start position:0% +and step and here we're going going +every other value so we're starting at + + align:start position:0% +every other value so we're starting at + + + align:start position:0% +every other value so we're starting at +five tell me what the next value is + + align:start position:0% +five tell me what the next value is + + + align:start position:0% +five tell me what the next value is +supposed to + + align:start position:0% +supposed to + + + align:start position:0% +supposed to +be if we're taking every other one seven + + align:start position:0% +be if we're taking every other one seven + + + align:start position:0% +be if we're taking every other one seven +and + + align:start position:0% +and + + + align:start position:0% +and +then nine and + + align:start position:0% +then nine and + + + align:start position:0% +then nine and +then are we doing 11 or not excellent + + align:start position:0% +then are we doing 11 or not excellent + + + align:start position:0% +then are we doing 11 or not excellent +nice yeah so we're going to the end + + align:start position:0% +nice yeah so we're going to the end + + + align:start position:0% +nice yeah so we're going to the end +minus + + align:start position:0% +minus + + + align:start position:0% +minus +one okay so it's possible that sometimes + + align:start position:0% +one okay so it's possible that sometimes + + + align:start position:0% +one okay so it's possible that sometimes +you write code where you might want to + + align:start position:0% +you write code where you might want to + + + align:start position:0% +you write code where you might want to +exit out of the loop early okay you + + align:start position:0% +exit out of the loop early okay you + + + align:start position:0% +exit out of the loop early okay you +don't want to go through all of the + + align:start position:0% +don't want to go through all of the + + + align:start position:0% +don't want to go through all of the +sequences of your numbers maybe there's + + align:start position:0% +sequences of your numbers maybe there's + + + align:start position:0% +sequences of your numbers maybe there's +a condition inside there where you just + + align:start position:0% +a condition inside there where you just + + + align:start position:0% +a condition inside there where you just +want to exit the loop early inside the Y + + align:start position:0% +want to exit the loop early inside the Y + + + align:start position:0% +want to exit the loop early inside the Y +Loop maybe you want to exit the loop + + align:start position:0% +Loop maybe you want to exit the loop + + + align:start position:0% +Loop maybe you want to exit the loop +before the condition becomes false so + + align:start position:0% +before the condition becomes false so + + + align:start position:0% +before the condition becomes false so +that's where the break statement comes + + align:start position:0% +that's where the break statement comes + + + align:start position:0% +that's where the break statement comes +in so the break works like this it's + + align:start position:0% +in so the break works like this it's + + + align:start position:0% +in so the break works like this it's +going to as soon as python sees this + + align:start position:0% +going to as soon as python sees this + + + align:start position:0% +going to as soon as python sees this +break + + align:start position:0% +break + + + align:start position:0% +break +statement it's going to say okay I'm + + align:start position:0% +statement it's going to say okay I'm + + + align:start position:0% +statement it's going to say okay I'm +going to look at whatever Loop I'm + + align:start position:0% +going to look at whatever Loop I'm + + + align:start position:0% +going to look at whatever Loop I'm +currently + + align:start position:0% +currently + + + align:start position:0% +currently +in I'm not evaluating any expression + + align:start position:0% +in I'm not evaluating any expression + + + align:start position:0% +in I'm not evaluating any expression +after it that comes within my + + align:start position:0% +after it that comes within my + + + align:start position:0% +after it that comes within my +Loop and I'm going to immediately exit + + align:start position:0% +Loop and I'm going to immediately exit + + + align:start position:0% +Loop and I'm going to immediately exit +the loop so I'm going inside this while + + align:start position:0% +the loop so I'm going inside this while + + + align:start position:0% +the loop so I'm going inside this while +this while I'm evaluating this one + + align:start position:0% +this while I'm evaluating this one + + + align:start position:0% +this while I'm evaluating this one +expression and then I suddenly see a + + align:start position:0% +expression and then I suddenly see a + + + align:start position:0% +expression and then I suddenly see a +break expression B does not get + + align:start position:0% +break expression B does not get + + + align:start position:0% +break expression B does not get +evaluated and break is going to + + align:start position:0% +evaluated and break is going to + + + align:start position:0% +evaluated and break is going to +immediately exit out of the innermost + + align:start position:0% +immediately exit out of the innermost + + + align:start position:0% +immediately exit out of the innermost +Loop that it's in so this y Loop that + + align:start position:0% +Loop that it's in so this y Loop that + + + align:start position:0% +Loop that it's in so this y Loop that +has condition two that's the innermost + + align:start position:0% +has condition two that's the innermost + + + align:start position:0% +has condition two that's the innermost +Loop that the brake is found found + + align:start position:0% +Loop that the brake is found found + + + align:start position:0% +Loop that the brake is found found +in so we're going to exit out of this + + align:start position:0% +in so we're going to exit out of this + + + align:start position:0% +in so we're going to exit out of this +innermost Loop here and we're evaluating + + align:start position:0% +innermost Loop here and we're evaluating + + + align:start position:0% +innermost Loop here and we're evaluating +expression C and notice we're evaluating + + align:start position:0% +expression C and notice we're evaluating + + + align:start position:0% +expression C and notice we're evaluating +expression C because it's expression C + + align:start position:0% +expression C because it's expression C + + + align:start position:0% +expression C because it's expression C +is part of the outer while + + align:start position:0% +is part of the outer while + + + align:start position:0% +is part of the outer while +loop it's at the same level as this one + + align:start position:0% +loop it's at the same level as this one + + + align:start position:0% +loop it's at the same level as this one +and these ones are part of the inner + + align:start position:0% +and these ones are part of the inner + + + align:start position:0% +and these ones are part of the inner +while loop + + align:start position:0% +while loop + + + align:start position:0% +while loop +okay okay last thing I want to say is + + align:start position:0% +okay okay last thing I want to say is + + + align:start position:0% +okay okay last thing I want to say is +just a little bit of a comparison + + align:start position:0% +just a little bit of a comparison + + + align:start position:0% +just a little bit of a comparison +between four and while Loops so when + + align:start position:0% +between four and while Loops so when + + + align:start position:0% +between four and while Loops so when +would you use one or the other um this + + align:start position:0% +would you use one or the other um this + + + align:start position:0% +would you use one or the other um this +might be useful in your problem sets so + + align:start position:0% +might be useful in your problem sets so + + + align:start position:0% +might be useful in your problem sets so +for Loops you usually use when you know + + align:start position:0% +for Loops you usually use when you know + + + align:start position:0% +for Loops you usually use when you know +the number of iterations + + align:start position:0% +the number of iterations + + + align:start position:0% +the number of iterations +okay y Loops are very useful when for + + align:start position:0% +okay y Loops are very useful when for + + + align:start position:0% +okay y Loops are very useful when for +example you're getting user input and + + align:start position:0% +example you're getting user input and + + + align:start position:0% +example you're getting user input and +user input is unpredictable right you + + align:start position:0% +user input is unpredictable right you + + + align:start position:0% +user input is unpredictable right you +don't know how many times they're going + + align:start position:0% +don't know how many times they're going + + + align:start position:0% +don't know how many times they're going +to do certain task for both four and Y + + align:start position:0% +to do certain task for both four and Y + + + align:start position:0% +to do certain task for both four and Y +Loops you can end out of the loop early + + align:start position:0% +Loops you can end out of the loop early + + + align:start position:0% +Loops you can end out of the loop early +using the break the four Loop uses this + + align:start position:0% +using the break the four Loop uses this + + + align:start position:0% +using the break the four Loop uses this +counter it's inherent inside the for + + align:start position:0% +counter it's inherent inside the for + + + align:start position:0% +counter it's inherent inside the for +Loop a while loop you can use a counter + + align:start position:0% +Loop a while loop you can use a counter + + + align:start position:0% +Loop a while loop you can use a counter +in order you can use a while loop to + + align:start position:0% +in order you can use a while loop to + + + align:start position:0% +in order you can use a while loop to +count things but you must initialize the + + align:start position:0% +count things but you must initialize the + + + align:start position:0% +count things but you must initialize the +counter before the Y Loop and you have + + align:start position:0% +counter before the Y Loop and you have + + + align:start position:0% +counter before the Y Loop and you have +to remember to increment it within the + + align:start position:0% +to remember to increment it within the + + + align:start position:0% +to remember to increment it within the +loop otherwise wise you'll you maybe + + align:start position:0% +loop otherwise wise you'll you maybe + + + align:start position:0% +loop otherwise wise you'll you maybe +lead to an infinite + + align:start position:0% +lead to an infinite + + + align:start position:0% +lead to an infinite +Loop we've seen in uh as the very first + + align:start position:0% +Loop we've seen in uh as the very first + + + align:start position:0% +Loop we've seen in uh as the very first +example of of a for Loop that the while + + align:start position:0% +example of of a for Loop that the while + + + align:start position:0% +example of of a for Loop that the while +loop the for Loop could be Rewritten as + + align:start position:0% +loop the for Loop could be Rewritten as + + + align:start position:0% +loop the for Loop could be Rewritten as +a while loop but the vice versa is not + + align:start position:0% +a while loop but the vice versa is not + + + align:start position:0% +a while loop but the vice versa is not +necessarily true and the counter example + + align:start position:0% +necessarily true and the counter example + + + align:start position:0% +necessarily true and the counter example +to that is just user input so you might + + align:start position:0% +to that is just user input so you might + + + align:start position:0% +to that is just user input so you might +not know how many times you might do a + + align:start position:0% +not know how many times you might do a + + + align:start position:0% +not know how many times you might do a +certain task all right great that's uh + + align:start position:0% +certain task all right great that's uh + + + align:start position:0% +certain task all right great that's uh +that's all for + + align:start position:0% + + + + align:start position:0% + +today \ No newline at end of file diff --git a/2f8CoFvB8uk.txt b/2f8CoFvB8uk.txt new file mode 100644 index 0000000000000000000000000000000000000000..7c31124f8bdcf6a0449d1415fc93efaad877d8e2 --- /dev/null +++ b/2f8CoFvB8uk.txt @@ -0,0 +1,1856 @@ +ANNOUNCER: The following content +is provided under a + +Creative Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high quality educational +resources for free. + +To make a donation or to view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +PROFESSOR: Hi. + +Our lecture for today I've +entitled 'Logarithms Without + +Exponents'. + +And before I try to clarify +that, let me make a couple of + +general remarks. + +First of all, we have now +completed the rudiments, the + +basics so to speak, of +both differential + +and integral calculus. + +Consequently, what our next +ambition will be is to take + +these principles and apply +them to special functions + +which are worthy of +investigation. + +And you see, in connection with +this, the first function + +that I've chosen to talk about +is called the logarithm. + +Now the other interesting thing +is that we are used to + +logarithms from high school +where they were viewed as + +being a different kind +of notation for + +talking about exponents. + +Now, in the same way when +we treated the circular + +functions, we mentioned that +one did not have to invent + +triangles to talk about +trigonometry. + +The interesting point is that +one does not have to talk + +about exponents to invent +the logarithm function. + +This is why I have entitled +the lesson, as I say, + +'Logarithms without +Exponents'. + +You see, what I would like to do +is try to mimic, especially + +from an engineering point of +view, how many of these + +mathematical topics +originated. + +Let's look at a rather +straightforward physical + +principle, a principle that I'm +sure we believe permeates + +many real life situations. + +It's what I call the rule +of compound interest. + +Namely, let's suppose we have a +physical situation in which + +the quantity that +we're measuring, + +which we'll call 'm'. + +In other words, the rate of +change of the quantity is + +proportional to the amount +present, 'dm/ dt' equals 'km'. + +Now notice that this is a pretty +harmless statement. + +The rate of change +is proportional + +to the amount present. + +We certainly would expect that +many experiments would run + +this way, and there seems to be +nothing at all supernatural + +about this kind of +an assumption. + +At any rate, let's apply our +previous principles, and see + +if we can't, from this +differential equation, figure + +out what 'm' has to be. + +Separating the variables, we +get that 'dm' over 'm' is + +equal to 'kdt'. + +And now integrating, meaning +taking the inverse derivative, + +we have what? + +That the integral of 'dm' +over 'm' is equal + +to 'kt' plus a constant. + +Now you see, the interesting +point is at this stage of the + +game, we do not know explicitly +how to find a + +function whose derivative with +respect to 'm' is '1 over m'. + +In fact, that's the +problem that + +underlies today's lecture. + +And we will try to answer this +question, showing how once we + +tackle this from a philosophic +point of view, the rest of the + +details follow from material +that we've already learned. + +At any rate, focusing our +attention on the problem, the + +question is this: to determine +a function, which I'll call + +capital 'L of x'-- + +the 'L' sort of to forewarn us +of the fact that we will + +somehow get a logarithm +out of this-- + +such that 'L prime of +x' is '1 over x'. + +And you see, what I want you to +notice is that if you write + +'1 over x' in exponential form, +in other words, if you + +try to write '1 over x' as 'x +to the n', notice that to + +solve this problem, 'L +of x' would be what? + +The integral of 'x' to +the 'minus 1 dx'. + +In other words, this is the case +of integral ''x to the n' + +dx', with 'n' equal +to minus 1. + +And you'll recall that when +we studied the recipe-- + +let me just write that over +here-- when we studied the + +recipe of how you integrate 'x +to the n', we saw that that + +was 'x to the 'n + 1'' over +'n + 1' plus a constant. + +And we then observed that this +doesn't even make sense when + +'n' is equal to minus 1, +because we have a 0 + +denominator. + +From the other point of view, +the way to look at + +this is we said what? + +That when you differentiate, you +lower the exponent by 1. + +Notice that to wind up with an +exponent of minus 1, we would + +have had to start with +an exponent of 0. + +But when you differentiate 'x' +to the 0, that being a + +constant, the derivative +of 'x' to the 0 is 0. + +It's not '1 over x'. + +You see, in other words, this +particular recipe that we're + +talking about, we don't +have working for us. + +In other words, this is an +interesting point again. + +You say gee whiz, if the recipe +for the integral ''x to + +the n' dx' works for everything +except 'n' equals + +minus 1, nothing's perfect. + +Let's be content. + +Since it works for every +number except + +that one, why worry? + +This is analogous to when +we talked about taking + +derivatives and saw that +we get a 0 over + +0 form every time. + +You see, if you pick a function +at random, the + +likelihood that the limit of +'f of x' as 'x' approaches + +'a', the likelihood of that +being 0 over 0 is very small, + +except when you form +the derivative, you + +always get 0 over 0. + +And in a similar way, granted +that integral ''x' to the + +minus 1 dx' is one very +special case. + +What we have seen is that this +comes up every single time + +that we want to solve a problem +of the form 'dm/ dt' + +equals 'km'. + +In other words then, what it +really boils down to is that + +unless we can come up with +a function 'L of x' whose + +derivative is '1 over x', we +cannot solve the problem that + +we started off today's +lesson with. + +In other words, we must leave +it in the form integral 'dm + +over m' equals 'kt' +plus a constant. + +Well at any rate, let's see what +such a function capital + +'L of x' must look like. + +I'm going to utilize both the +differential calculus approach + +and the integral calculus +approach. + +By differential calculus, +assuming that 'y' equals 'L of + +x', what do we know about +the function 'y'? + +By definition, we've defined it +to be that function whose + +derivative is '1 over x'. + +So we know its derivative +is '1 over x'. + +The next point is that knowing +that 'y prime' is '1 over x', + +and even though we can't +integrate '1 over x', we can + +certainly differentiate +'1 over x'. + +We can now differentiate +'1 over x'. + +The derivative of '1 over x' is +minus '1 over 'x squared'', + +and we find that 'y +double prime' is + +minus '1 over 'x squared''. + +By the way, we should observe +that we must shy away from 'x' + +equaling 0, because you see, we +would have a 0 denominator + +in that case. + +If we think of most physical +situations, notice that we + +talk about the amount-- + +the rate of change +is proportional + +to the amount present. + +From a physical point of view, +the amount present can't be + +negative, so let's put the +restriction on here that the + +domain of 'L' will be all +positive numbers. + +Now here's the interesting +thing. + +Intuitively, I can now visualize +how the function 'L + +of x' must look. + +Namely, since its first +derivative is '1 over x' and + +'x' is greater than 0, that +tells me that the curve is + +always rising. + +And secondly, since '1 over 'x +squared'' is always positive, + +minus '1 over 'x squared'' is +always negative, that tells me + +that my curve is always +spilling water. + +In essence then, what +must the curve do? + +The curve must be rising +but spilling water. + +In other words, the curve +'L of x' belongs to this + +particular family. + +Notice that once we have one +curve which we call 'y' equals + +'L of x', by any displacement +parallel-- + +vertical displacement, +we get what? + +A member called 'y' equals +'L of x' plus 'c'. + +All that changes is what? + +The point at which the curve +crosses the x-axis, but + +whichever member of the +family we pick, what + +typifies 'L of x'? + +Its derivative is '1 over x'. + +In other words, somehow or +other, we visualize that 'L of + +x' exists, and its graph +is something like this. + +Now suppose we want a more +tangible form, namely how do + +you compute 'L of x' +for a given 'x'? + +I thought what might be a nice +review now is to see how we + +can use our integral calculus +approach, and in particular + +the second fundamental theorem +of interval calculus. + +By the integral calculus +approach, we do is is we pick + +any positive number 'a', and +once picked, we fix it. + +You see, we have a great deal +of freedom in how we choose + +the positive number a. + +But let's pick one and +leave it here. + +Now what we'll do is in the +'y-t' plane, we'll draw the + +curve 'y' equals '1 over t'. + +And what we'll do now, we'll +study the area of the region + +'R' where 'R' is bounded above +by 'y' equals '1 over t', on + +the left by 't' equals 'a', on +the right by 't' equals 'x', + +and below by the t-axis. + +Now we've already seen that the +function that we get by + +taking the definite integral +from 'a' 'to x', 'dt over t', + +has the property that its +derivative is '1 over x'. + +In other words, recall from the +fundamental theorem, this + +is just a generalization of the +fact that if 'f of t' is a + +continuous function, then the +integral from 'a' to 'x', ''f + +of t' dt', is a function +of 'x'. + +And its derivative with +respect to 'x' + +is just 'f of x'. + +You see, in other words, I can +now view capital 'L of x' as + +being an area under the curve +'y' equals '1 over t'. + +Notice that I have a degree of +freedom here, namely what that + +area is depends on where +I choose 'a'. + +Notice that if I choose a +differently, changing 'a'-- + +let's call this 'a +prime', say-- + +changing 'a' changes the area +under the curve, but notice it + +changes it by a fixed amount. + +In other words, notice that +shifting 'a' just changes 'L + +of x' by a constant, +just like the + +ordinary in definite integral. + +At any rate, these are the two +approaches that we have. + +And if we superimpose them, +all we're saying is what? + +If you start with the +differential calculus + +approach, 'y' equals capital 'L +of x' must be a member of + +this family, crossing the axis +at some point (a,0) . + +And from the integral calculus +point of view, if you take the + +curve 'y' equals '1 over t' +and compute the area under + +that curve from 'a' +to 'x', that area + +function is 'L of x'. + +Now we'll let that rest for the +time being, and now have a + +brief digression. + +You see, sooner or later, I've +got to get to what a logarithm + +is, and we might just +as well do that now. + +So let's now take a look and +see what we mean by a + +logarithmic function. + +You see, quite frequently in +mathematics, what one does is + +one deals with a particular +special case in which one is + +interested. + +And having deduced very nice +results, he looks at this + +thing and says, you know, all +of these results came from a + +particular recipe, a particular +structure that this + +system obeyed. + +What he then does is he takes +this recipe or structure, + +gives it a general name, and +now is able to extend this + +property to a larger +class of objects. + +For example, let's +look at this way. + +What is the nice thing about +logarithms in the traditional + +sense of the word? + +Remember when we learned +logarithms in high school, by + +use of logarithms, we were able +to replace multiplication + +problems by addition problems, +et cetera. + +In other words, remember the +key structural property was + +that the logarithm of a product +was the sum of the + +logarithms. + +That was the structural thing +that we used over and over and + +over again. + +In fact, it's rather interesting +to point out that + +in many cases where we used the +properties of logarithms, + +we never really had to know +what a logarithm was. + +All we had to know was what? + +What properties did it obey, +and did we have a book of + +tables so we could look up the +logarithm when we had to. + +Well at any rate, using this as +motivation, we now define a + +logarithmic function, +specifically a function f is + +called logarithmic if for all +'x1', 'x2' in the domain of + +'f', 'f' of the product of 'x1' +and 'x2' is 'f of x1' + +plus 'f of x2'. + +In other words, since we know +what nice properties a + +logarithm has, let's define +any function 'f' to be + +logarithmic if 'f' of a +product is equal to + +the sum of the 'f's. + +Now you see, this may sound +like a pretty simple + +statement, but it's +quite demanding. + +In other words, notice-- + +by the way, somebody says, +I wonder if there are any + +logarithmic functions? + +You see, notice that by the way +we began, there must be at + +least one logarithmic function, + +namely the usual logarithm. + +We know there's at least one +function which has these + +properties. + +So the set of all logarithmic +functions is certainly + +not the empty set. + +At any rate, let's see what +we can deduce about any + +logarithmic function. + +Well for example, I claim that +if 'f' is logarithmic, 'f of + +1' must be 0. + +Why is that? + +Well, notice that 1 can be +written as 1 times 1. + +And since 'f of 1' times +1 is 'f of 1' plus 'f + +of 1', we have what? + +That 'f of 1' is equal to 'f of +1' plus 'f of 1', therefore + +twice 'f of 1' is 'f of 1', +and therefore by algebraic + +manipulation, 'f of 1' is 0. + +Which, by the way, does check +out with the usual logarithm, + +the logarithm of 1 to +any base 'b' is 0. + +Secondly, if 'f of '1 over x'' +is defined, you see in other + +words, I'm not sure whether '1 +over x' is in the domain of + +'f' just because 'x' is, but +suppose '1 over x' is in the + +domain of 'f'. + +Then 'f of '1 over x'' is +equal to minus 'f of x'. + +In other words, 'f' of a number +is minus 'f' of the + +reciprocal of that number. + +Again, a familiar logarithmic +property, why does it follow + +from our basic definition? + +Well notice that we already +know that 'f of 1' is 0. + +We also know that 1 is equal +to 'x' times '1 over x', + +provided 'x' is not 0. + +By the way, if 'x' were 0, 1 +over 0 wouldn't be defined, so + +we wouldn't be worrying +about that anyway. + +But notice now we have what? + +If 'x' is not 0, 'f of 'x times +'1 over x'' is 0, but by + +the logarithmic property, that's +also 'f of x' plus 'f + +of '1 over x''. + +Since these two together add up +to 0, 'f of '1 over x' must + +just be minus 'f of x'. + +And we'll just take a few more +properties like this just to + +make sure that you see what +properties logarithmic + +functions have. + +Remember again the ordinary +logarithm, the logarithm of a + +quotient was the difference +of the logarithms. + +Again, 'f of 'x over y'' +is equal to 'f of + +x' minus 'f of y'. + +Why is that the case? + +Well, look at 'f +of 'x over y''. + +That says 'f of x' +times '1 over y'. + +But again, by logarithmic +properties, 'f' of a product + +is the sum of the 'f's. + +Therefore 'f of 'x times '1 over +y''' is 'f of x' plus 'f + +of '1 over y''. + +But we just saw that 'f of '1 +over y' is minus 'f of y'. + +So we have this familiar +result now. + +And finally, by mathematical +induction, if 'n' is any + +positive integer, 'f of x' to +the n-th power is just 'n' + +times 'f of x'. + +And the proof is rather clear. + +Namely, 'f of x' to the n-th +power when 'n' is a positive + +integer means 'f of 'x' +times 'x' times 'x' + +times 'x'', 'n' times. + +And since the logarithmic +property says that 'f' of a + +product is a sum of the 'f's, +that's equal to 'f of x' plus + +'f of x' plus et cetera plus 'f +of x', 'n' times, and that + +precisely is just 'n' +times 'f of x'. + +In other words, notice that +our definition of a + +logarithmic function, simply +that 'f of 'x1 times x2'' is + +equal to 'f of x1' plus 'f of +x2' allows us to deduce all of + +the familiar properties that +were known to us in terms of + +the traditional meaning +of logarithm. + +And now we come to the most +important question of today's + +lecture, and that is what does +all of this discussion have to + +do with the function that we've +called capital 'L of x'? + +And that's what will +tackle next. + +Let's take a look and see +whether capital 'L of x' is + +indeed a logarithmic function. + +Well, if 'L' is to be a +logarithmic function, if 'b' + +is any constant, in particular +'L of 'b times x'' had better + +be equal to 'L of b' +plus 'L of x'. + +That's the definition +of logarithmic. + +Now we don't know +if that's true. + +What do we have at our disposal +to be able to see + +whether we can solve this +problem or not? + +How do we, using calculus, +check to see whether two + +functions are equal? + +Remember the standard +approach is what? + +Take the derivative +of both sides. + +If the derivatives are +equal, then the + +functions differ by a constant. + +And if we can show that that +constant is 0, then the two + +functions are equal. + +So let's take a look and see +how that works over here. + +First of all, let's see what the +derivative of 'L of bx' is + +with respect to 'x'. + +And by the way, here again is +the beauty of what we mean + +when we say that all of the +study that we're making allows + +us to utilize every fundamental +result that we've + +learned before. + +We've learned that the basic +definition of 'L' is what? + +That if you differentiate 'L' +with respect to the given + +variable, you get 1 over +that variable. + +We want the derivative of 'L +of bx' with respect to 'x'. + +Now, you see the idea is the +derivative of 'L of u' with + +respect to 'u' is '1 over u'. + +You see by the chain rule, if we +were differentiating 'L of + +bx' with respect to 'bx', that +would be '1 over bx'. + +I shouldn't say by the +chain rule yet. + +What I'm saying is if we +differentiate 'L of bx' with + +respect to 'bx', we would +have '1 over bx'. + +But we're not differentiating +with respect to 'bx', we're + +differentiating with +respect to 'x'. + +And this is where the +chain rule comes in. + +Namely, we rewrite the +derivative of 'L of bx' with + +respect to 'x' as the derivative +'L of bx' with + +respect to 'bx' times the +derivative of 'bx' with + +respect to 'b'. + +And in this way we get what? + +The first factor +is '1 over bx'. + +The second factor +is 'b' itself-- + +remember 'b' is a constant-- + +and therefore the derivative +of 'L of bx' is '1 over x'. + +On the other hand, what is +the derivative of 'L of + +b' plus 'L of x'? + +Since 'b' is a constant, the +derivative 'L of b' is 0. + +And by definition, the +derivative of 'L of x' with + +respect to 'x' is '1 over x'. + +And now you see, comparing these +two results, we see that + +'L of bx' and 'L of b' plus 'L +of x have the same derivative, + +hence they differ by a constant +which I'll call 'c'. + +In other words, notice that +capital 'L' is what I call + +almost logarithmic. + +If it weren't for this factor +constant 'c' in here, it would + +be a logarithmic function. + +Well at any rate, +what do we have? + +We know that capital 'L of bx' +is equal to capital 'L of b' + +plus capital 'L of x' plus +some constant 'c'. + +To evaluate the constant, we +only have to evaluate it at + +one element in the domain, let's +pick 'x' equal to 1. + +The motif being that if 'x' is +1, notice that on the left + +hand side you have an 'L of b' +term, on the right hand side + +you have an 'L of b' term, +and they will cancel. + +In other words, if 'x' is 1, +this equation becomes 'L of b' + +equals 'L of b' plus 'L of 1' +plus 'c', from which it + +follows that 'c' is +minus 'L of 1'. + +'c' is minus 'L of 1'. + +Now what do we want to 'c' to +be if 'c' were equal to 0? + +If 'c' where equal to 0, this +would be logarithmic, and all + +we need to make 'c' equal to 0 +is to set 'L of 1' equal to 0. + +In other words, summarizing this +result, capital 'L of x' + +is logarithmic if capital +'L of 1' is 0. + +Now remember, we have a whole +family of 'L's that work. + +What we're saying now is let's +pick the member of the family + +of 'L's that passes through +the point (1,0) . + +And because that's logarithmic, +let's give that a + +special name. + +In essence, we will define +this symbol. + +It's written 'ln of x'. + +It will later be called the +natural logarithm of 'x'. + +I'm trying to avoid the word +logarithm here as much as + +possible, because I want you to +see that we haven't had to + +use exponents at all in making +this kind of a definition. + +But let's define 'ln of x' to +be the member of the family + +capital 'L of x' plus +'c' which passes + +through the point (1,0). + +In essence then, what +is 'ln of x'? + +I'll call it natural log, it's +easier for me to say. + +The natural 'log of x' is that +function whose derivative with + +respect to 'x' is '1 over +x', and characterized by + +the fact that what? + +If the input is 1, +the output is 0. + +In other words, the graph +passes through + +the point (1 , 0). + +Again, notice that in terms +of what we said earlier in + +today's lesson, we talked about +the functions 'L of x', + +and talked about, in the +differential calculus + +approach, the curve could +go through any + +point on the x-axis. + +What we're saying is now if the +point on the x-axis that + +the curve crosses at is (1 , +0), that's what 'lnx' will + +mean, the natural +log function. + +In terms of the integral +calculus approach, if the + +particular 'a' value that we +choose, the fixed value that + +we're going to study the area +under, notice that all we're + +saying is pick 'a' to be 1. + +And by the way, as a +quick check, all + +we're saying is what? + +The 'natural log of x' is +defined to be the area under + +this curve as a function +of 'x'. + +In terms of the definite +integral, that's the integral + +from '1 to x,' 'dt over t'. + +And notice that if you pick 'x' +to be 1, the natural log + +of 1 is the integral from 1 to +1 'dt over t', and that's 0, + +just as it should be. + +So at any rate now, that +tells me how to + +define the natural log. + +Am I doing this in terms +of exponents? + +No. + +I am trying to do what? + +Find a function whose derivative +with respect to 'x' + +is '1 over x', and I'd also like +that function, since it's + +that close to being a +logarithmic function, to be a + +logarithmic function. + +In other words, this is how I +invented the function 'ln of + +x', the 'natural log of x'. + +It's derivative with respect to +'x' is '1 over x', and the + +natural log of a product is the +sum of the natural logs. + +And by the way, that's exactly +how we use this material. + +Let me just take a few minutes +and go over something that we + +already had an answer +for, just to show + +you how this works. + +Let me try to rederive the +product rule using logarithms. + +Suppose 'u' and 'v' are +differentiable functions of + +'x', and I want to find the +derivative of 'u' times 'v' + +with respect to 'x'. + +In other words, I'd like +to find 'dy dx'. + +OK, I take the natural +log of both sides. + +In other words, I say if 'y' +equals 'u' times 'v', the + +natural log 'y' equals natural +log 'u times v'. + +Now what is the property that +the natural log function has? + +I deliberately chose it to be +that member of the l family + +that was logarithmic. + +The natural log of 'u times +v' is 'natural log u' plus + +'natural log v'. + +Now, can I differentiate +this implicitly + +with respect to 'x'? + +You see how all of our +old stuff keeps + +coming up in new context. + +I take this equation and I +differentiate it implicitly + +with respect to 'x'. + +The derivative of the +left hand side is '1 + +over y', 'dy dx'. + +The derivative of the right +hand side is what? + +Well, the derivative of 'log u' +with respect to 'u' is '1 + +over u', but I'm differentiating +it with + +respect to 'x', so I must use +the correction factor by the + +chain rule 'du dx'. + +And similarly, the derivative of +'log v' with respect to 'x' + +is '1 over v', 'dv dx'. + +And now multiplying through by +'y', I have obtained that 'dy + +dx' is ''y over u' du dx' +plus ''y over v' dv dx'. + +But remembering that 'y' is +equal to 'u' times 'v', this + +becomes 'v 'du dx'' plus 'u 'dv +dx', and we have arrived + +at the familiar product +rule using logarithmic + +differentiation. + +You see the point that's really +important to stress + +here it that it wasn't important +whether the natural + +log was an exponent or not. + +The important thing that we used +about logarithms, whether + +it was our high school course, +whether it's going to be in + +our college calculus course, the +important thing was what? + +That when we wanted to write the +log of a product, it was + +the sum of the logs. + +And now the only additional +fact that we have from the + +calculus approach is that the +derivative of 'log x' with + +respect to 'x' was defined +to be '1 over x'. + +By the way, since there is +a tendency to think of + +traditional logarithms when one +uses the word logarithm, + +if we so wanted-- + +and there's no reason why +we have to do this-- + +if we wanted to associate +a base with + +the natural log system-- + +this is just a little aside, and +we'll talk about this more + +perhaps in the learning +exercises or in the + +supplementary notes +as need be-- + +but the idea is this. + +Notice that in a traditional +logarithm system, if the base + +is 'b', the base is +characterized by the fact that + +the 'log of 'b to the +base b'' is 1. + +Thus, if we use 'e' to denote +the base for the natural log, + +whatever 'e' is, it must be +characterized by the fact that + +the 'natural log of e' is 1. + +And the reason that I put the +word base in quotation marks + +here is that I would like you +to observe that again, if I + +have never heard of the word +exponent, it still makes sense + +to say find the number e +such that the 'natural + +log of e' is 1. + +In fact, I can give you two +interpretations for that + +number 'e', and as a byproduct, +even show you why + +the second fundamental theorem +of integral calculus is as + +powerful as it really is. + +See, the idea is this. + +To find what 'e' is, all we're +saying is take the curve 'y' + +equals 'natural log x'. + +Look to see where the +y-coordinate is 1. + +In other words, draw the +line 'y' equals 1. + +Where that line intercepts the +curve 'y' equals 'log x', that + +x-coordinate is 'e'. + +In other words, the 'natural log +of e' must be 1, so this + +is geometrically how I would +locate 'e' using + +differential calculus. + +If I wanted to use integral +calculus, notice that the 'log + +of e' by definition is what? + +The integral from 1 to +'e', 'dt over t'. + +That's the area of +this region 'R'. + +Now what do I want 'e' to be? + +I want 'e' to be that number +that makes this area 1. + +In other words, I want the +'natural log of e' to be 1. + +So again, in the same way that +one can think of pi as being + +geometrically constructed, +notice I can construct 'e' + +geometrically, namely +again what? + +I take the curve 'y' equals '1 +over t' from 't' equals 1, + +bounded below by the t-axis, +and I keep shifting over to + +the right until the area of this +region 'R' is exactly 1. + +The 't' value that makes this +area 1 is called 'e'. + +And by the way, notice again +the power of what I mean by + +the area approach. + +Notice I can start now to +get estimates on what + +'e' must look like. + +Let me show you what I'm +driving at over here. + +Let's suppose we take the curve +'y' equals '1 over t' + +from 1 to 2. + +Now what do we mean +by natural log 2? + +Natural log 2 is by definition +the area of this region here. + +Now notice that the smallest +height of this region, since + +the curve is 'y' equals '1 over +t', the smallest height + +of this region is 1/2, and the +tallest height, the highest + +height in this region is 1. + +Consequently, whatever the area +of this region is, it's + +less than the area of the +inscribed rectangle-- + +it's greater than the area of +the inscribed rectangle, and + +less than the area of the +circumscribed rectangle. + +Now notice that both of these +rectangles have base 1, and + +we're going from 1 to 2. + +The height of the inscribed +rectangle is 1/2, therefore + +the area of the small +rectangle is 1/2. + +The area of the big rectangle, +it's a 1 by 1 rectangle, is 1. + +And now what we have is that +whatever the natural log of 2 + +is, it being the area of this +region, it must be what? + +Less than 1 but greater +than 1/2. + +We also know that whatever +'e' is, the 'log of + +e' is equal to 1. + +Well, let's go on a little +bit further. + +What about the log of 4? + +The log of 4, natural log of +4, is the log of 2 squared. + +But we've already seen that +one of the properties of a + +logarithmic function is that +you can bring the exponent + +down as a multiplier. + +See, 'f of 'x to the n'' +is 'n 'f of x''. + +This becomes 2 log 2, and +because the natural log of 2 + +is greater than 1/2, twice +the natural log of 2 + +is more than 1. + +In other words, if log 2 is more +than 1/2, twice log 2 is + +more than 1. + +In other words, if we put these +three lines together, we + +have that the natural log of 2 +is less than the 'natural log + +of e', which in turn is less +than the natural log of 4. + +By the way, notice that since +the derivative of 'log x' with + +respect to 'x' is '1 over x', +and that's positive, 'log x' + +is a one to one function. + +Therefore, if the log of 2 is +less than the 'log of e' is + +less than the log of 4, it +follows that 2 must be less + +than 'e', which in turn +must be less than 4. + +In other words, even with this +crude approximation of just + +inscribing and circumscribing +rectangles, I can show again + +without reference to exponents +that whatever the number 'e' + +is, the number e defined by the +fact that 'ln of e' is 1, + +that number 'e' is some number +between 2 and 4. + +But again, we won't dwell +on this too long. + +What I want to do now is to come +back to a summary point, + +and at the same time, +lead into the + +lecture for next time. + +Recall that we began this +lecture with the problem of + +solving the situation where +the rate of change was + +proportional to the +amount present. + +Given 'dm/ dt' equals 'km', we +separated variables and got + +down to the stage where the +integral of 'dm over m' was + +'kt' plus a constant. + +And all we did in the rest of +today's lecture that was at + +all different, was we invented +and constructed the particular + +function whose derivative would +be '1 over m', and which + +had the logarithmic property. + +In other words, we can now +say that this is the + +answer to the problem. + +This problem is explicitly +solved because the natural log + +function can be viewed as +an area under a curve. + +We can construct it +for each 'm'. + +This is then what we +managed to do. + +And by the way, all I'm saying +now is that since the log is a + +one to one function-- + +see, its derivative is +always positive-- + +can't we talk about the +inverse function? + +In other words, notice that +another way of writing this is + +that id 'natural log m' is 'kt' +plus 'c', 'm' itself must + +be the 'inverse log +of kt' plus 'c'. + +And you see, next time what +we're going to do is to + +explore what we mean +by the inverse log. + +At any rate, in summarizing +today's lecture, to make sure + +that we didn't fall victim to +all the computational details, + +notice that all we did was +physically motivated the + +necessity for inventing a +function whose derivative with + +respect to 'x' was '1 over x'. + +And from that point on, +everything else that we did + +followed as applications of +material that came before. + +It's in this sense that the +course now picks up in tempo. + +That as we go on now, we're +going to be able to cover + +larger globs of material in one +sitting, because we will + +find, at least for the next +several lectures, that every + +new topic is basically one new +idea together with all of the + +old recipes. + +At any rate, until next +time, goodbye. + +ANNOUNCER: Funding for the +publication of this video was + +provided by the Gabriella and +Paul Rosenbaum Foundation. + +Help OCW continue to provide +free and open access to MIT + +courses by making a donation +at ocw.mit.edu/donate. \ No newline at end of file diff --git a/2jHK2MxGoio.txt b/2jHK2MxGoio.txt new file mode 100644 index 0000000000000000000000000000000000000000..80760b36f0864dacfc14d643c0978b0ef31d055d --- /dev/null +++ b/2jHK2MxGoio.txt @@ -0,0 +1,1475 @@ +align:start position:0% + +welcome back to special relativity 820. + + align:start position:0% +welcome back to special relativity 820. + + + align:start position:0% +welcome back to special relativity 820. +after discussing energy and momentum um + + align:start position:0% +after discussing energy and momentum um + + + align:start position:0% +after discussing energy and momentum um +and examples with collisions we now want + + align:start position:0% +and examples with collisions we now want + + + align:start position:0% +and examples with collisions we now want +to talk about forces + + align:start position:0% +to talk about forces + + + align:start position:0% +to talk about forces +and + + align:start position:0% +and + + + align:start position:0% +and +we get back to the example of alice + + align:start position:0% +we get back to the example of alice + + + align:start position:0% +we get back to the example of alice +traveling to the center of the galaxy + + align:start position:0% +traveling to the center of the galaxy + + + align:start position:0% +traveling to the center of the galaxy +and asking what does it mean in terms of + + align:start position:0% +and asking what does it mean in terms of + + + align:start position:0% +and asking what does it mean in terms of +acceleration + + align:start position:0% +acceleration + + + align:start position:0% +acceleration +so + + align:start position:0% +so + + + align:start position:0% +so +we start from newton's second law we + + align:start position:0% +we start from newton's second law we + + + align:start position:0% +we start from newton's second law we +know that a force is a change in + + align:start position:0% +know that a force is a change in + + + align:start position:0% +know that a force is a change in +momentum + + align:start position:0% +momentum + + + align:start position:0% +momentum +we can write this down as + + align:start position:0% +we can write this down as + + + align:start position:0% +we can write this down as +d + + align:start position:0% +d + + + align:start position:0% +d +d dt uh m naught + + align:start position:0% +d dt uh m naught + + + align:start position:0% +d dt uh m naught +over + + align:start position:0% +over + + + align:start position:0% +over +times u over square root 1 minus u + + align:start position:0% +times u over square root 1 minus u + + + align:start position:0% +times u over square root 1 minus u +square over c square + + align:start position:0% +square over c square + + + align:start position:0% +square over c square +or just with a gamma vector + + align:start position:0% +or just with a gamma vector + + + align:start position:0% +or just with a gamma vector +and the thing to consider here is that + + align:start position:0% +and the thing to consider here is that + + + align:start position:0% +and the thing to consider here is that +now the gamma factor + + align:start position:0% +now the gamma factor + + + align:start position:0% +now the gamma factor +and the velocity are actually time + + align:start position:0% +and the velocity are actually time + + + align:start position:0% +and the velocity are actually time +dependent so there's two components to + + align:start position:0% +dependent so there's two components to + + + align:start position:0% +dependent so there's two components to +this we'll come back to this + + align:start position:0% +this we'll come back to this + + + align:start position:0% +this we'll come back to this +the kinetic energy + + align:start position:0% +the kinetic energy + + + align:start position:0% +the kinetic energy +is the work done by an external force + + align:start position:0% +is the work done by an external force + + + align:start position:0% +is the work done by an external force +and you can get to the kinetic energy by + + align:start position:0% +and you can get to the kinetic energy by + + + align:start position:0% +and you can get to the kinetic energy by +just integrating let's say from a + + align:start position:0% +just integrating let's say from a + + + align:start position:0% +just integrating let's say from a +particle which is accelerated by an + + align:start position:0% +particle which is accelerated by an + + + align:start position:0% +particle which is accelerated by an +external force from a velocity zero to + + align:start position:0% +external force from a velocity zero to + + + align:start position:0% +external force from a velocity zero to +some velocity v + + align:start position:0% +some velocity v + + + align:start position:0% +some velocity v +that's the integral um over this over + + align:start position:0% +that's the integral um over this over + + + align:start position:0% +that's the integral um over this over +the path of the particle + + align:start position:0% +the path of the particle + + + align:start position:0% +the path of the particle +of the path of this object times the + + align:start position:0% +of the path of this object times the + + + align:start position:0% +of the path of this object times the +force + + align:start position:0% +force + + + align:start position:0% +force +if you just + + align:start position:0% +if you just + + + align:start position:0% +if you just +assume here uniform + + align:start position:0% +assume here uniform + + + align:start position:0% +assume here uniform +motion in x direction then this + + align:start position:0% +motion in x direction then this + + + align:start position:0% +motion in x direction then this +simplifies to just an f dx + + align:start position:0% +simplifies to just an f dx + + + align:start position:0% +simplifies to just an f dx +okay so as a first activity i want you + + align:start position:0% +okay so as a first activity i want you + + + align:start position:0% +okay so as a first activity i want you +to find the kinetic energy of an object + + align:start position:0% +to find the kinetic energy of an object + + + align:start position:0% +to find the kinetic energy of an object +with velocity v + + align:start position:0% +with velocity v + + + align:start position:0% +with velocity v +and the mass and mass m naught + + align:start position:0% +and the mass and mass m naught + + + align:start position:0% +and the mass and mass m naught +and as a second part i want you to test + + align:start position:0% +and as a second part i want you to test + + + align:start position:0% +and as a second part i want you to test +this result + + align:start position:0% +this result + + + align:start position:0% +this result +for velocities much much smaller than + + align:start position:0% +for velocities much much smaller than + + + align:start position:0% +for velocities much much smaller than +the speed of light where you used to + + align:start position:0% +the speed of light where you used to + + + align:start position:0% +the speed of light where you used to +doing this kind of calculation and + + align:start position:0% +doing this kind of calculation and + + + align:start position:0% +doing this kind of calculation and +you're familiar with the outcome + + align:start position:0% +you're familiar with the outcome + + + align:start position:0% +you're familiar with the outcome +so we just have to integrate just have + + align:start position:0% +so we just have to integrate just have + + + align:start position:0% +so we just have to integrate just have +to integrate so this is a little bit + + align:start position:0% +to integrate so this is a little bit + + + align:start position:0% +to integrate so this is a little bit +involved here + + align:start position:0% +involved here + + + align:start position:0% +involved here +so we have to integrate from zero to v m + + align:start position:0% +so we have to integrate from zero to v m + + + align:start position:0% +so we have to integrate from zero to v m +naught that's our constant you can take + + align:start position:0% +naught that's our constant you can take + + + align:start position:0% +naught that's our constant you can take +that out d dt of this u um + + align:start position:0% +that out d dt of this u um + + + align:start position:0% +that out d dt of this u um +u times gamma dx okay so you find those + + align:start position:0% +u times gamma dx okay so you find those + + + align:start position:0% +u times gamma dx okay so you find those +two components here + + align:start position:0% +two components here + + + align:start position:0% +two components here +um + + align:start position:0% +um + + + align:start position:0% +um +and then we do a trick where you know we + + align:start position:0% +and then we do a trick where you know we + + + align:start position:0% +and then we do a trick where you know we +introduce this du the x + + align:start position:0% +introduce this du the x + + + align:start position:0% +introduce this du the x +the x + + align:start position:0% +the x + + + align:start position:0% +the x +um and then the integral becomes an m + + align:start position:0% +um and then the integral becomes an m + + + align:start position:0% +um and then the integral becomes an m +times udu + + align:start position:0% +times udu + + + align:start position:0% +times udu +over one minus u square over c square + + align:start position:0% +over one minus u square over c square + + + align:start position:0% +over one minus u square over c square +third + + align:start position:0% +third + + + align:start position:0% +third +to the third + + align:start position:0% +to the third + + + align:start position:0% +to the third +to this + + align:start position:0% +to this + + + align:start position:0% +to this +third power half + + align:start position:0% +third power half + + + align:start position:0% +third power half +okay and then you can just look up the + + align:start position:0% +okay and then you can just look up the + + + align:start position:0% +okay and then you can just look up the +integral or work it out not that + + align:start position:0% +integral or work it out not that + + + align:start position:0% +integral or work it out not that +difficult actually but you find that + + align:start position:0% +difficult actually but you find that + + + align:start position:0% +difficult actually but you find that +this is equal to m naught times c square + + align:start position:0% +this is equal to m naught times c square + + + align:start position:0% +this is equal to m naught times c square +over + + align:start position:0% +over + + + align:start position:0% +over +square root 1 minus u square over c + + align:start position:0% +square root 1 minus u square over c + + + align:start position:0% +square root 1 minus u square over c +square which you have to evaluate for + + align:start position:0% +square which you have to evaluate for + + + align:start position:0% +square which you have to evaluate for +velocities v and 0. + + align:start position:0% +velocities v and 0. + + + align:start position:0% +velocities v and 0. +and when you do that you find those two + + align:start position:0% +and when you do that you find those two + + + align:start position:0% +and when you do that you find those two +components here okay the first one is m + + align:start position:0% +components here okay the first one is m + + + align:start position:0% +components here okay the first one is m +naught c square + + align:start position:0% +naught c square + + + align:start position:0% +naught c square +times gamma and the second one is m + + align:start position:0% +times gamma and the second one is m + + + align:start position:0% +times gamma and the second one is m +naught c square + + align:start position:0% +naught c square + + + align:start position:0% +naught c square +so that result is actually not too + + align:start position:0% +so that result is actually not too + + + align:start position:0% +so that result is actually not too +surprising as we saw + + align:start position:0% +surprising as we saw + + + align:start position:0% +surprising as we saw +that we can write the energy + + align:start position:0% + + + + align:start position:0% + +equal to + + align:start position:0% +equal to + + + align:start position:0% +equal to +m naught c square + + align:start position:0% +m naught c square + + + align:start position:0% +m naught c square +plus k + + align:start position:0% +plus k + + + align:start position:0% +plus k +and what we just calculated here from + + align:start position:0% +and what we just calculated here from + + + align:start position:0% +and what we just calculated here from +this example + + align:start position:0% +this example + + + align:start position:0% +this example +is k + + align:start position:0% +is k + + + align:start position:0% +is k +is equal to energy + + align:start position:0% +is equal to energy + + + align:start position:0% +is equal to energy +minus + + align:start position:0% +minus + + + align:start position:0% +minus +m naught c square + + align:start position:0% +m naught c square + + + align:start position:0% +m naught c square +okay so that result already makes sense + + align:start position:0% +okay so that result already makes sense + + + align:start position:0% +okay so that result already makes sense +in with respect to the discussion we had + + align:start position:0% +in with respect to the discussion we had + + + align:start position:0% +in with respect to the discussion we had +at this point + + align:start position:0% +at this point + + + align:start position:0% +at this point +okay or you can simplify this by saying + + align:start position:0% +okay or you can simplify this by saying + + + align:start position:0% +okay or you can simplify this by saying +the kinetic energy is gamma minus 1 + + align:start position:0% +the kinetic energy is gamma minus 1 + + + align:start position:0% +the kinetic energy is gamma minus 1 +times m naught c square + + align:start position:0% +times m naught c square + + + align:start position:0% +times m naught c square +okay so if we now evaluate this for + + align:start position:0% +okay so if we now evaluate this for + + + align:start position:0% +okay so if we now evaluate this for +small values of of v + + align:start position:0% +small values of of v + + + align:start position:0% +small values of of v +as we did before we find that the + + align:start position:0% +as we did before we find that the + + + align:start position:0% +as we did before we find that the +kinetic energy is one half m naught v + + align:start position:0% +kinetic energy is one half m naught v + + + align:start position:0% +kinetic energy is one half m naught v +square and + + align:start position:0% +square and + + + align:start position:0% +square and +i find it interesting illustrated what + + align:start position:0% +i find it interesting illustrated what + + + align:start position:0% +i find it interesting illustrated what +this means now so if you plot the + + align:start position:0% +this means now so if you plot the + + + align:start position:0% +this means now so if you plot the +kinetic energy of a particle as a + + align:start position:0% +kinetic energy of a particle as a + + + align:start position:0% +kinetic energy of a particle as a +function of its velocity we find that + + align:start position:0% +function of its velocity we find that + + + align:start position:0% +function of its velocity we find that +you know at for small values + + align:start position:0% +you know at for small values + + + align:start position:0% +you know at for small values +those two curves you know basically + + align:start position:0% +those two curves you know basically + + + align:start position:0% +those two curves you know basically +overlap because more values + + align:start position:0% +overlap because more values + + + align:start position:0% +overlap because more values +m naught c squared + + align:start position:0% +m naught c squared + + + align:start position:0% +m naught c squared +times gamma minus one is basically the + + align:start position:0% +times gamma minus one is basically the + + + align:start position:0% +times gamma minus one is basically the +same + + align:start position:0% +same + + + align:start position:0% +same +as one half mv square which is + + align:start position:0% +as one half mv square which is + + + align:start position:0% +as one half mv square which is +just derived here from the taylor + + align:start position:0% +just derived here from the taylor + + + align:start position:0% +just derived here from the taylor +expansion + + align:start position:0% +expansion + + + align:start position:0% +expansion +but for larger values this diverges and + + align:start position:0% +but for larger values this diverges and + + + align:start position:0% +but for larger values this diverges and +especially when you get closer to the + + align:start position:0% +especially when you get closer to the + + + align:start position:0% +especially when you get closer to the +speed of light + + align:start position:0% +speed of light + + + align:start position:0% +speed of light +um you know just to get a quantitative + + align:start position:0% +um you know just to get a quantitative + + + align:start position:0% +um you know just to get a quantitative +example i ask you to do another + + align:start position:0% +example i ask you to do another + + + align:start position:0% +example i ask you to do another +calculation here i want you to + + align:start position:0% +calculation here i want you to + + + align:start position:0% +calculation here i want you to +reinvestigate alice's journey to the + + align:start position:0% +reinvestigate alice's journey to the + + + align:start position:0% +reinvestigate alice's journey to the +center of the galaxy where she has a + + align:start position:0% +center of the galaxy where she has a + + + align:start position:0% +center of the galaxy where she has a +spacecraft which moves with a gamma + + align:start position:0% +spacecraft which moves with a gamma + + + align:start position:0% +spacecraft which moves with a gamma +factor of 15 000 + + align:start position:0% +factor of 15 000 + + + align:start position:0% +factor of 15 000 +an acceleration of 10 meters per second + + align:start position:0% +an acceleration of 10 meters per second + + + align:start position:0% +an acceleration of 10 meters per second +square and the mass of the spacecraft + + align:start position:0% +square and the mass of the spacecraft + + + align:start position:0% +square and the mass of the spacecraft +that says 10 000 metric tons or 10 000 + + align:start position:0% +that says 10 000 metric tons or 10 000 + + + align:start position:0% +that says 10 000 metric tons or 10 000 +but + + align:start position:0% +but + + + align:start position:0% +but +sorry 100 metric tons or 100 000 + + align:start position:0% +sorry 100 metric tons or 100 000 + + + align:start position:0% +sorry 100 metric tons or 100 000 +kilograms so compare the kinetic energy + + align:start position:0% +kilograms so compare the kinetic energy + + + align:start position:0% +kilograms so compare the kinetic energy +using newtonian mechanics or special + + align:start position:0% +using newtonian mechanics or special + + + align:start position:0% +using newtonian mechanics or special +military and you find that the + + align:start position:0% +military and you find that the + + + align:start position:0% +military and you find that the +difference + + align:start position:0% +difference + + + align:start position:0% +difference +is astonishingly large so if you just + + align:start position:0% +is astonishingly large so if you just + + + align:start position:0% +is astonishingly large so if you just +work this out one half m + + align:start position:0% +work this out one half m + + + align:start position:0% +work this out one half m +c square we can just use c square here + + align:start position:0% +c square we can just use c square here + + + align:start position:0% +c square we can just use c square here +because the velocity is basically + + align:start position:0% +because the velocity is basically + + + align:start position:0% +because the velocity is basically +c + + align:start position:0% +c + + + align:start position:0% +c +um + + align:start position:0% +um + + + align:start position:0% +um +5 times 10 to the + + align:start position:0% +5 times 10 to the + + + align:start position:0% +5 times 10 to the +22 kilograms meter square over second + + align:start position:0% +22 kilograms meter square over second + + + align:start position:0% +22 kilograms meter square over second +second square + + align:start position:0% +second square + + + align:start position:0% +second square +and in the relativistic terms + + align:start position:0% +and in the relativistic terms + + + align:start position:0% +and in the relativistic terms +the answer is 30 000 times larger + + align:start position:0% +the answer is 30 000 times larger + + + align:start position:0% +the answer is 30 000 times larger +so 30 000 times larger than the + + align:start position:0% +so 30 000 times larger than the + + + align:start position:0% +so 30 000 times larger than the +classical k so the huge difference + + align:start position:0% +classical k so the huge difference + + + align:start position:0% +classical k so the huge difference +between the classical evaluation and the + + align:start position:0% +between the classical evaluation and the + + + align:start position:0% +between the classical evaluation and the +evaluation and the special relativity + + align:start position:0% +evaluation and the special relativity + + + align:start position:0% +evaluation and the special relativity +one more uh word on m + + align:start position:0% +one more uh word on m + + + align:start position:0% +one more uh word on m +f equal m a + + align:start position:0% +f equal m a + + + align:start position:0% +f equal m a +uh the question is how does this + + align:start position:0% +uh the question is how does this + + + align:start position:0% +uh the question is how does this +transform on a learner's transformation + + align:start position:0% +transform on a learner's transformation + + + align:start position:0% +transform on a learner's transformation +is something we already halfway figured + + align:start position:0% +is something we already halfway figured + + + align:start position:0% +is something we already halfway figured +out so here you basically want to see + + align:start position:0% +out so here you basically want to see + + + align:start position:0% +out so here you basically want to see +how a + + align:start position:0% +how a + + + align:start position:0% +how a +uh transforms under loans transformation + + align:start position:0% +uh transforms under loans transformation + + + align:start position:0% +uh transforms under loans transformation +we have started the discussion by saying + + align:start position:0% +we have started the discussion by saying + + + align:start position:0% +we have started the discussion by saying +you know in galilean transformations + + align:start position:0% +you know in galilean transformations + + + align:start position:0% +you know in galilean transformations +acceleration is invariant + + align:start position:0% +acceleration is invariant + + + align:start position:0% +acceleration is invariant +while endurance transformation that's + + align:start position:0% +while endurance transformation that's + + + align:start position:0% +while endurance transformation that's +not the case but if you investigate + + align:start position:0% +not the case but if you investigate + + + align:start position:0% +not the case but if you investigate +again the second law of uh of physics + + align:start position:0% +again the second law of uh of physics + + + align:start position:0% +again the second law of uh of physics +and the force is a change in momentum + + align:start position:0% +and the force is a change in momentum + + + align:start position:0% +and the force is a change in momentum +you find that you get those two + + align:start position:0% +you find that you get those two + + + align:start position:0% +you find that you get those two +components here + + align:start position:0% +components here + + + align:start position:0% +components here +one + + align:start position:0% +one + + + align:start position:0% +one +is + + align:start position:0% +is + + + align:start position:0% +is +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +parallel to the acceleration so m times + + align:start position:0% +parallel to the acceleration so m times + + + align:start position:0% +parallel to the acceleration so m times +gamma a + + align:start position:0% +gamma a + + + align:start position:0% +gamma a +but the second one is not the second one + + align:start position:0% +but the second one is not the second one + + + align:start position:0% +but the second one is not the second one +is m naught times u + + align:start position:0% +is m naught times u + + + align:start position:0% +is m naught times u +times the change in time of the gamma + + align:start position:0% +times the change in time of the gamma + + + align:start position:0% +times the change in time of the gamma +factor and that's not parallel + + align:start position:0% +factor and that's not parallel + + + align:start position:0% +factor and that's not parallel +to f or to a + + align:start position:0% +to f or to a + + + align:start position:0% +to f or to a +and so you find that + + align:start position:0% +and so you find that + + + align:start position:0% +and so you find that +there's two the new vector the new force + + align:start position:0% +there's two the new vector the new force + + + align:start position:0% +there's two the new vector the new force +of a particle is not parallel to the + + align:start position:0% +of a particle is not parallel to the + + + align:start position:0% +of a particle is not parallel to the +acceleration anymore that's kind of + + align:start position:0% +acceleration anymore that's kind of + + + align:start position:0% +acceleration anymore that's kind of +content to + + align:start position:0% +content to + + + align:start position:0% +content to +content \ No newline at end of file diff --git a/3gxNrc_EEN8.txt b/3gxNrc_EEN8.txt new file mode 100644 index 0000000000000000000000000000000000000000..2832b17b47503818fe8e338769203b91e204a04a --- /dev/null +++ b/3gxNrc_EEN8.txt @@ -0,0 +1,3128 @@ +align:start position:0% + +on the evening of August 5th 2012 + + align:start position:0% +on the evening of August 5th 2012 + + + align:start position:0% +on the evening of August 5th 2012 +Pacific Daylight Time NASA's Mars Rover + + align:start position:0% +Pacific Daylight Time NASA's Mars Rover + + + align:start position:0% +Pacific Daylight Time NASA's Mars Rover +named curiosity entered Mars atmosphere + + align:start position:0% +named curiosity entered Mars atmosphere + + + align:start position:0% +named curiosity entered Mars atmosphere +at 20,000 km per hour drag slowed it + + align:start position:0% +at 20,000 km per hour drag slowed it + + + align:start position:0% +at 20,000 km per hour drag slowed it +down to around 1,600 km hour at which + + align:start position:0% +down to around 1,600 km hour at which + + + align:start position:0% +down to around 1,600 km hour at which +point a parachute opened this parachute + + align:start position:0% +point a parachute opened this parachute + + + align:start position:0% +point a parachute opened this parachute +slowed the Rover more to about 320 kmph + + align:start position:0% +slowed the Rover more to about 320 kmph + + + align:start position:0% +slowed the Rover more to about 320 kmph +or 90 + + align:start position:0% +or 90 + + + align:start position:0% +or 90 +m/s finally after Rockets decelerated it + + align:start position:0% +m/s finally after Rockets decelerated it + + + align:start position:0% +m/s finally after Rockets decelerated it +completely the Rover was lower to the + + align:start position:0% +completely the Rover was lower to the + + + align:start position:0% +completely the Rover was lower to the +surface of Mars every step of this dance + + align:start position:0% +surface of Mars every step of this dance + + + align:start position:0% +surface of Mars every step of this dance +was carefully choreographed and + + align:start position:0% +was carefully choreographed and + + + align:start position:0% +was carefully choreographed and +rehearsed in many experiments here on + + align:start position:0% +rehearsed in many experiments here on + + + align:start position:0% +rehearsed in many experiments here on +Earth but how could NASA Engineers be + + align:start position:0% +Earth but how could NASA Engineers be + + + align:start position:0% +Earth but how could NASA Engineers be +sure that their designs would work on a + + align:start position:0% +sure that their designs would work on a + + + align:start position:0% +sure that their designs would work on a +totally different planet the answer is a + + align:start position:0% +totally different planet the answer is a + + + align:start position:0% +totally different planet the answer is a +problem solving method called + + align:start position:0% +problem solving method called + + + align:start position:0% +problem solving method called +dimensional + + align:start position:0% +dimensional + + + align:start position:0% +dimensional +analysis this video is part of the + + align:start position:0% +analysis this video is part of the + + + align:start position:0% +analysis this video is part of the +problem solving video + + align:start position:0% +problem solving video + + + align:start position:0% +problem solving video +series problem solving skills in in + + align:start position:0% +series problem solving skills in in + + + align:start position:0% +series problem solving skills in in +combination with an understanding of the + + align:start position:0% +combination with an understanding of the + + + align:start position:0% +combination with an understanding of the +natural and human-made world are + + align:start position:0% +natural and human-made world are + + + align:start position:0% +natural and human-made world are +critical to the design and optimization + + align:start position:0% +critical to the design and optimization + + + align:start position:0% +critical to the design and optimization +of systems and + + align:start position:0% +of systems and + + + align:start position:0% +of systems and +processes hi my name is Ken Cameron and + + align:start position:0% +processes hi my name is Ken Cameron and + + + align:start position:0% +processes hi my name is Ken Cameron and +I'm a professor of mechanical + + align:start position:0% +I'm a professor of mechanical + + + align:start position:0% +I'm a professor of mechanical +engineering at + + align:start position:0% +engineering at + + + align:start position:0% +engineering at +MIT dimensional analysis is a powerful + + align:start position:0% +MIT dimensional analysis is a powerful + + + align:start position:0% +MIT dimensional analysis is a powerful +tool I use it Nasa uses it and you will + + align:start position:0% +tool I use it Nasa uses it and you will + + + align:start position:0% +tool I use it Nasa uses it and you will +too before watching this video you + + align:start position:0% +too before watching this video you + + + align:start position:0% +too before watching this video you +should be familiar with unit analysis + + align:start position:0% +should be familiar with unit analysis + + + align:start position:0% +should be familiar with unit analysis +and understand the difference between + + align:start position:0% +and understand the difference between + + + align:start position:0% +and understand the difference between +dependent and independent variables by + + align:start position:0% +dependent and independent variables by + + + align:start position:0% +dependent and independent variables by +the end of this video you will be able + + align:start position:0% +the end of this video you will be able + + + align:start position:0% +the end of this video you will be able +to use dimensional analysis to estimate + + align:start position:0% +to use dimensional analysis to estimate + + + align:start position:0% +to use dimensional analysis to estimate +the size of a parachute canopy that can + + align:start position:0% +the size of a parachute canopy that can + + + align:start position:0% +the size of a parachute canopy that can +slow the Rover down to 90 m/s on its + + align:start position:0% +slow the Rover down to 90 m/s on its + + + align:start position:0% +slow the Rover down to 90 m/s on its +descent to + + align:start position:0% + + + + align:start position:0% + +Mars before we talk about dimensional + + align:start position:0% +Mars before we talk about dimensional + + + align:start position:0% +Mars before we talk about dimensional +analysis we need to know what dimension + + align:start position:0% +analysis we need to know what dimension + + + align:start position:0% +analysis we need to know what dimension +is dimensions and units are related but + + align:start position:0% +is dimensions and units are related but + + + align:start position:0% +is dimensions and units are related but +different concepts physical quantities + + align:start position:0% +different concepts physical quantities + + + align:start position:0% +different concepts physical quantities +are measured in units the dimension of + + align:start position:0% +are measured in units the dimension of + + + align:start position:0% +are measured in units the dimension of +the physical quantity is independent of + + align:start position:0% +the physical quantity is independent of + + + align:start position:0% +the physical quantity is independent of +the particular unit chosen for example + + align:start position:0% +the particular unit chosen for example + + + align:start position:0% +the particular unit chosen for example +both gr and kilograms are units but they + + align:start position:0% +both gr and kilograms are units but they + + + align:start position:0% +both gr and kilograms are units but they +are units of mass and mass is what we'll + + align:start position:0% +are units of mass and mass is what we'll + + + align:start position:0% +are units of mass and mass is what we'll +call the dimension there are five + + align:start position:0% +call the dimension there are five + + + align:start position:0% +call the dimension there are five +fundamental Dimensions that we commonly + + align:start position:0% +fundamental Dimensions that we commonly + + + align:start position:0% +fundamental Dimensions that we commonly +deal with length mass time temperature + + align:start position:0% +deal with length mass time temperature + + + align:start position:0% +deal with length mass time temperature +and + + align:start position:0% +and + + + align:start position:0% +and +charge all other dimensions are obtained + + align:start position:0% +charge all other dimensions are obtained + + + align:start position:0% +charge all other dimensions are obtained +by taking products and powers of these + + align:start position:0% +by taking products and powers of these + + + align:start position:0% +by taking products and powers of these +fundamental + + align:start position:0% +fundamental + + + align:start position:0% +fundamental +dimensions in this video we'll be + + align:start position:0% +dimensions in this video we'll be + + + align:start position:0% +dimensions in this video we'll be +dealing with length which we denote by + + align:start position:0% +dealing with length which we denote by + + + align:start position:0% +dealing with length which we denote by +the letter L Mass denoted by m and time + + align:start position:0% +the letter L Mass denoted by m and time + + + align:start position:0% +the letter L Mass denoted by m and time +T for example no matter how you measure + + align:start position:0% +T for example no matter how you measure + + + align:start position:0% +T for example no matter how you measure +the physical quantity velocity it has + + align:start position:0% +the physical quantity velocity it has + + + align:start position:0% +the physical quantity velocity it has +the dimension which we denote with + + align:start position:0% +the dimension which we denote with + + + align:start position:0% +the dimension which we denote with +square brackets of length ID time or + + align:start position:0% +square brackets of length ID time or + + + align:start position:0% +square brackets of length ID time or +length time time to the 1 + + align:start position:0% +length time time to the 1 + + + align:start position:0% +length time time to the 1 +Power Pause the video here and determine + + align:start position:0% +Power Pause the video here and determine + + + align:start position:0% +Power Pause the video here and determine +the dimension of + + align:start position:0% + + + + align:start position:0% + +energy + + align:start position:0% + + + + align:start position:0% + +energy has Dimension mass time length + + align:start position:0% +energy has Dimension mass time length + + + align:start position:0% +energy has Dimension mass time length +squared over time + + align:start position:0% +squared over time + + + align:start position:0% +squared over time +squared okay great so what's the big + + align:start position:0% +squared okay great so what's the big + + + align:start position:0% +squared okay great so what's the big +deal how is this + + align:start position:0% +deal how is this + + + align:start position:0% +deal how is this +useful remember NASA's + + align:start position:0% +useful remember NASA's + + + align:start position:0% +useful remember NASA's +rover part of the landing sequence calls + + align:start position:0% +rover part of the landing sequence calls + + + align:start position:0% +rover part of the landing sequence calls +for a parachute to slow the vehicle down + + align:start position:0% +for a parachute to slow the vehicle down + + + align:start position:0% +for a parachute to slow the vehicle down +suppose it is our job to design the + + align:start position:0% +suppose it is our job to design the + + + align:start position:0% +suppose it is our job to design the +parachute to slow the Rover to exactly + + align:start position:0% +parachute to slow the Rover to exactly + + + align:start position:0% +parachute to slow the Rover to exactly +90 m/ second + + align:start position:0% +90 m/ second + + + align:start position:0% +90 m/ second +the terminal velocity of the Rover + + align:start position:0% +the terminal velocity of the Rover + + + align:start position:0% +the terminal velocity of the Rover +depends on the mass of the Rover itself + + align:start position:0% +depends on the mass of the Rover itself + + + align:start position:0% +depends on the mass of the Rover itself +and its heat shield and several + + align:start position:0% +and its heat shield and several + + + align:start position:0% +and its heat shield and several +different variables related to the + + align:start position:0% +different variables related to the + + + align:start position:0% +different variables related to the +parachute design the material of the + + align:start position:0% +parachute design the material of the + + + align:start position:0% +parachute design the material of the +canopy the diameter of the hemispherical + + align:start position:0% +canopy the diameter of the hemispherical + + + align:start position:0% +canopy the diameter of the hemispherical +parachute canopy the number of + + align:start position:0% +parachute canopy the number of + + + align:start position:0% +parachute canopy the number of +suspension lines + + align:start position:0% +suspension lines + + + align:start position:0% +suspension lines +etc for Simplicity let's suppose that + + align:start position:0% +etc for Simplicity let's suppose that + + + align:start position:0% +etc for Simplicity let's suppose that +all parachute parameters other than the + + align:start position:0% +all parachute parameters other than the + + + align:start position:0% +all parachute parameters other than the +diameter of the canopy have already been + + align:start position:0% +diameter of the canopy have already been + + + align:start position:0% +diameter of the canopy have already been +determined our goal is to find the + + align:start position:0% +determined our goal is to find the + + + align:start position:0% +determined our goal is to find the +canopy diameter that is as small as + + align:start position:0% +canopy diameter that is as small as + + + align:start position:0% +canopy diameter that is as small as +possible but will correspond to the + + align:start position:0% +possible but will correspond to the + + + align:start position:0% +possible but will correspond to the +desired terminal velocity of 90 + + align:start position:0% +desired terminal velocity of 90 + + + align:start position:0% +desired terminal velocity of 90 +m/s clearly we can't test our designs on + + align:start position:0% +m/s clearly we can't test our designs on + + + align:start position:0% +m/s clearly we can't test our designs on +Mars the question is how can we get + + align:start position:0% +Mars the question is how can we get + + + align:start position:0% +Mars the question is how can we get +meaningful data here on Earth that will + + align:start position:0% +meaningful data here on Earth that will + + + align:start position:0% +meaningful data here on Earth that will +allow us to appropriately size the + + align:start position:0% +allow us to appropriately size the + + + align:start position:0% +allow us to appropriately size the +parachute for use on + + align:start position:0% +parachute for use on + + + align:start position:0% +parachute for use on +Mars how do we predict the behavior of a + + align:start position:0% +Mars how do we predict the behavior of a + + + align:start position:0% +Mars how do we predict the behavior of a +parachute on Mars based on an earth + + align:start position:0% +parachute on Mars based on an earth + + + align:start position:0% +parachute on Mars based on an earth +experiment and what variables do we need + + align:start position:0% +experiment and what variables do we need + + + align:start position:0% +experiment and what variables do we need +to consider in designing our experiment + + align:start position:0% +to consider in designing our experiment + + + align:start position:0% +to consider in designing our experiment +on Earth + + align:start position:0% +on Earth + + + align:start position:0% +on Earth +this is where a problemsolving method + + align:start position:0% +this is where a problemsolving method + + + align:start position:0% +this is where a problemsolving method +called dimensional analysis can help + + align:start position:0% + + + + align:start position:0% + +us before we get started we must first + + align:start position:0% +us before we get started we must first + + + align:start position:0% +us before we get started we must first +determine what the dependent and + + align:start position:0% +determine what the dependent and + + + align:start position:0% +determine what the dependent and +independent variables are in our + + align:start position:0% +independent variables are in our + + + align:start position:0% +independent variables are in our +system the dependent variable is + + align:start position:0% +system the dependent variable is + + + align:start position:0% +system the dependent variable is +terminal velocity this is the quantity + + align:start position:0% +terminal velocity this is the quantity + + + align:start position:0% +terminal velocity this is the quantity +that we wish to constrain by our + + align:start position:0% +that we wish to constrain by our + + + align:start position:0% +that we wish to constrain by our +parachute + + align:start position:0% +parachute + + + align:start position:0% +parachute +design so what variables affect the + + align:start position:0% +design so what variables affect the + + + align:start position:0% +design so what variables affect the +terminal velocity of the parachute in + + align:start position:0% +terminal velocity of the parachute in + + + align:start position:0% +terminal velocity of the parachute in +the Rover + + align:start position:0% +the Rover + + + align:start position:0% +the Rover +system the diameter of the parachute + + align:start position:0% +system the diameter of the parachute + + + align:start position:0% +system the diameter of the parachute +canopy is one such independent variable + + align:start position:0% +canopy is one such independent variable + + + align:start position:0% +canopy is one such independent variable +take a moment to pause the video and + + align:start position:0% +take a moment to pause the video and + + + align:start position:0% +take a moment to pause the video and +identify + + align:start position:0% + + + + align:start position:0% + +others okay here's our list canopy + + align:start position:0% +others okay here's our list canopy + + + align:start position:0% +others okay here's our list canopy +diameter mass of the Rover we assume the + + align:start position:0% +diameter mass of the Rover we assume the + + + align:start position:0% +diameter mass of the Rover we assume the +mass of the parachute to be + + align:start position:0% +mass of the parachute to be + + + align:start position:0% +mass of the parachute to be +negligible acceleration due to gravity + + align:start position:0% +negligible acceleration due to gravity + + + align:start position:0% +negligible acceleration due to gravity +and the density and viscosity of the + + align:start position:0% +and the density and viscosity of the + + + align:start position:0% +and the density and viscosity of the +atmosphere for this problem we can + + align:start position:0% +atmosphere for this problem we can + + + align:start position:0% +atmosphere for this problem we can +assume that the dependence of the + + align:start position:0% +assume that the dependence of the + + + align:start position:0% +assume that the dependence of the +terminal velocity on atmospheric + + align:start position:0% +terminal velocity on atmospheric + + + align:start position:0% +terminal velocity on atmospheric +viscosity is negligible because the + + align:start position:0% +viscosity is negligible because the + + + align:start position:0% +viscosity is negligible because the +atmosphere on Mars like the atmosphere + + align:start position:0% +atmosphere on Mars like the atmosphere + + + align:start position:0% +atmosphere on Mars like the atmosphere +on Earth is not very + + align:start position:0% +on Earth is not very + + + align:start position:0% +on Earth is not very +viscous if we wanted to derive a + + align:start position:0% +viscous if we wanted to derive a + + + align:start position:0% +viscous if we wanted to derive a +functional relationship that would work + + align:start position:0% +functional relationship that would work + + + align:start position:0% +functional relationship that would work +for example underwater it would be + + align:start position:0% +for example underwater it would be + + + align:start position:0% +for example underwater it would be +important that we include viscosity as + + align:start position:0% +important that we include viscosity as + + + align:start position:0% +important that we include viscosity as +an independent + + align:start position:0% +an independent + + + align:start position:0% +an independent +variable why didn't we include the + + align:start position:0% +variable why didn't we include the + + + align:start position:0% +variable why didn't we include the +surface area of the parachute canopy in + + align:start position:0% +surface area of the parachute canopy in + + + align:start position:0% +surface area of the parachute canopy in +our list of independent + + align:start position:0% +our list of independent + + + align:start position:0% +our list of independent +variables pause the video and take a + + align:start position:0% +variables pause the video and take a + + + align:start position:0% +variables pause the video and take a +moment to discuss with a + + align:start position:0% + + + + align:start position:0% + +classmate we didn't include the surface + + align:start position:0% +classmate we didn't include the surface + + + align:start position:0% +classmate we didn't include the surface +area of the canopy because it is not + + align:start position:0% +area of the canopy because it is not + + + align:start position:0% +area of the canopy because it is not +independent from the diameter of the + + align:start position:0% +independent from the diameter of the + + + align:start position:0% +independent from the diameter of the +canopy in fact we can determine the area + + align:start position:0% +canopy in fact we can determine the area + + + align:start position:0% +canopy in fact we can determine the area +as a function of diameter so we don't + + align:start position:0% +as a function of diameter so we don't + + + align:start position:0% +as a function of diameter so we don't +need + + align:start position:0% +need + + + align:start position:0% +need +both question could we use the surface + + align:start position:0% +both question could we use the surface + + + align:start position:0% +both question could we use the surface +area instead of the diameter absolutely + + align:start position:0% +area instead of the diameter absolutely + + + align:start position:0% +area instead of the diameter absolutely +we need the variables to be independent + + align:start position:0% +we need the variables to be independent + + + align:start position:0% +we need the variables to be independent +but it doesn't matter which variables we + + align:start position:0% +but it doesn't matter which variables we + + + align:start position:0% +but it doesn't matter which variables we +use the key is to have identified all of + + align:start position:0% +use the key is to have identified all of + + + align:start position:0% +use the key is to have identified all of +the correct variables to begin with this + + align:start position:0% +the correct variables to begin with this + + + align:start position:0% +the correct variables to begin with this +is where human error can come into play + + align:start position:0% +is where human error can come into play + + + align:start position:0% +is where human error can come into play +if our list of variables isn't + + align:start position:0% +if our list of variables isn't + + + align:start position:0% +if our list of variables isn't +exhaustive the relationship we develop + + align:start position:0% +exhaustive the relationship we develop + + + align:start position:0% +exhaustive the relationship we develop +through dimensional analysis may not be + + align:start position:0% +through dimensional analysis may not be + + + align:start position:0% +through dimensional analysis may not be +correct once we have the full list of + + align:start position:0% +correct once we have the full list of + + + align:start position:0% +correct once we have the full list of +independent variables we can express the + + align:start position:0% +independent variables we can express the + + + align:start position:0% +independent variables we can express the +terminal velocity as some function of + + align:start position:0% +terminal velocity as some function of + + + align:start position:0% +terminal velocity as some function of +these independent variables + + align:start position:0% +these independent variables + + + align:start position:0% +these independent variables +in order to find the function that + + align:start position:0% +in order to find the function that + + + align:start position:0% +in order to find the function that +describes the relationship we need to do + + align:start position:0% +describes the relationship we need to do + + + align:start position:0% +describes the relationship we need to do +several experiments involving four + + align:start position:0% +several experiments involving four + + + align:start position:0% +several experiments involving four +independent variables and fit the + + align:start position:0% +independent variables and fit the + + + align:start position:0% +independent variables and fit the +data that's a lot of work especially + + align:start position:0% +data that's a lot of work especially + + + align:start position:0% +data that's a lot of work especially +because we don't know what the function + + align:start position:0% +because we don't know what the function + + + align:start position:0% +because we don't know what the function +might look + + align:start position:0% +might look + + + align:start position:0% +might look +like but whenever you have an equation + + align:start position:0% +like but whenever you have an equation + + + align:start position:0% +like but whenever you have an equation +all terms in the equations must have the + + align:start position:0% +all terms in the equations must have the + + + align:start position:0% +all terms in the equations must have the +same + + align:start position:0% +same + + + align:start position:0% +same +Dimension multiplying two terms + + align:start position:0% +Dimension multiplying two terms + + + align:start position:0% +Dimension multiplying two terms +multiplies the + + align:start position:0% +multiplies the + + + align:start position:0% +multiplies the +dimensions this restricts the possible + + align:start position:0% +dimensions this restricts the possible + + + align:start position:0% +dimensions this restricts the possible +form that a function describing the + + align:start position:0% +form that a function describing the + + + align:start position:0% +form that a function describing the +terminal velocity in terms of our four + + align:start position:0% +terminal velocity in terms of our four + + + align:start position:0% +terminal velocity in terms of our four +other variables can take because the + + align:start position:0% +other variables can take because the + + + align:start position:0% +other variables can take because the +function must combine the variables in + + align:start position:0% +function must combine the variables in + + + align:start position:0% +function must combine the variables in +some way that has the same Dimension as + + align:start position:0% +some way that has the same Dimension as + + + align:start position:0% +some way that has the same Dimension as +velocity and many functions exponential + + align:start position:0% +velocity and many functions exponential + + + align:start position:0% +velocity and many functions exponential +logarithmic + + align:start position:0% +logarithmic + + + align:start position:0% +logarithmic +trigonometric cannot have input + + align:start position:0% +trigonometric cannot have input + + + align:start position:0% +trigonometric cannot have input +variables that have Dimension what would + + align:start position:0% +variables that have Dimension what would + + + align:start position:0% +variables that have Dimension what would +e to the 1 kilogram mean what units + + align:start position:0% +e to the 1 kilogram mean what units + + + align:start position:0% +e to the 1 kilogram mean what units +could it possibly + + align:start position:0% +could it possibly + + + align:start position:0% +could it possibly +have where we're going to show you a + + align:start position:0% +have where we're going to show you a + + + align:start position:0% +have where we're going to show you a +problem solving method that will allow + + align:start position:0% +problem solving method that will allow + + + align:start position:0% +problem solving method that will allow +you to find the most general form of + + align:start position:0% +you to find the most general form of + + + align:start position:0% +you to find the most general form of +such a function this method is called + + align:start position:0% +such a function this method is called + + + align:start position:0% +such a function this method is called +dimensional + + align:start position:0% + + + + align:start position:0% + +analysis We Begin this process by + + align:start position:0% +analysis We Begin this process by + + + align:start position:0% +analysis We Begin this process by +creating dimensionless versions of the + + align:start position:0% +creating dimensionless versions of the + + + align:start position:0% +creating dimensionless versions of the +variables in our + + align:start position:0% +variables in our + + + align:start position:0% +variables in our +system we create these dimensionless + + align:start position:0% +system we create these dimensionless + + + align:start position:0% +system we create these dimensionless +Expressions out of the variables in our + + align:start position:0% +Expressions out of the variables in our + + + align:start position:0% +Expressions out of the variables in our +system so we don't introduce any new + + align:start position:0% +system so we don't introduce any new + + + align:start position:0% +system so we don't introduce any new +physical + + align:start position:0% +physical + + + align:start position:0% +physical +parameters the first step is to take our + + align:start position:0% +parameters the first step is to take our + + + align:start position:0% +parameters the first step is to take our +list of variables and distill them down + + align:start position:0% +list of variables and distill them down + + + align:start position:0% +list of variables and distill them down +to their fundamental Dimensions remember + + align:start position:0% +to their fundamental Dimensions remember + + + align:start position:0% +to their fundamental Dimensions remember +our fundamental dimensions are length + + align:start position:0% +our fundamental dimensions are length + + + align:start position:0% +our fundamental dimensions are length +mass and time distilling gravity to its + + align:start position:0% +mass and time distilling gravity to its + + + align:start position:0% +mass and time distilling gravity to its +fundamental Dimension we get length per + + align:start position:0% +fundamental Dimension we get length per + + + align:start position:0% +fundamental Dimension we get length per +time + + align:start position:0% +time + + + align:start position:0% +time +squared now you distill the remaining + + align:start position:0% +squared now you distill the remaining + + + align:start position:0% +squared now you distill the remaining +variables of velocity diameter mass and + + align:start position:0% +variables of velocity diameter mass and + + + align:start position:0% +variables of velocity diameter mass and +density into their fundamental + + align:start position:0% +density into their fundamental + + + align:start position:0% +density into their fundamental +Dimensions pause the video + + align:start position:0% + + + + align:start position:0% + +here + + align:start position:0% + + + + align:start position:0% + +velocity is length per time diameter is + + align:start position:0% +velocity is length per time diameter is + + + align:start position:0% +velocity is length per time diameter is +length mass is mass and density is mass + + align:start position:0% +length mass is mass and density is mass + + + align:start position:0% +length mass is mass and density is mass +per length + + align:start position:0% +per length + + + align:start position:0% +per length +cubed the second step is to express the + + align:start position:0% +cubed the second step is to express the + + + align:start position:0% +cubed the second step is to express the +fundamental dimensions of mass length + + align:start position:0% +fundamental dimensions of mass length + + + align:start position:0% +fundamental dimensions of mass length +and time in terms of our + + align:start position:0% +and time in terms of our + + + align:start position:0% +and time in terms of our +variables we can write M as Little M we + + align:start position:0% +variables we can write M as Little M we + + + align:start position:0% +variables we can write M as Little M we +can write L as mass / density to the 1/3 + + align:start position:0% +can write L as mass / density to the 1/3 + + + align:start position:0% +can write L as mass / density to the 1/3 +power we can write t as velocity div by + + align:start position:0% +power we can write t as velocity div by + + + align:start position:0% +power we can write t as velocity div by +gravity we had many choices as to how to + + align:start position:0% +gravity we had many choices as to how to + + + align:start position:0% +gravity we had many choices as to how to +write these fundamental dimensions in + + align:start position:0% +write these fundamental dimensions in + + + align:start position:0% +write these fundamental dimensions in +terms of our variables in the end it + + align:start position:0% +terms of our variables in the end it + + + align:start position:0% +terms of our variables in the end it +doesn't matter which Expressions you + + align:start position:0% +doesn't matter which Expressions you + + + align:start position:0% +doesn't matter which Expressions you +choose the third step is to use these + + align:start position:0% +choose the third step is to use these + + + align:start position:0% +choose the third step is to use these +fundamental Dimensions to turn all of + + align:start position:0% +fundamental Dimensions to turn all of + + + align:start position:0% +fundamental Dimensions to turn all of +the variables involved into + + align:start position:0% +the variables involved into + + + align:start position:0% +the variables involved into +dimensionless quantities for example the + + align:start position:0% +dimensionless quantities for example the + + + align:start position:0% +dimensionless quantities for example the +terminal velocity V has dimension of + + align:start position:0% +terminal velocity V has dimension of + + + align:start position:0% +terminal velocity V has dimension of +length over + + align:start position:0% +length over + + + align:start position:0% +length over +time so we multiply V + + align:start position:0% +time so we multiply V + + + align:start position:0% +time so we multiply V +by the dimension of + + align:start position:0% + + + + align:start position:0% + +time and divide by the dimension of + + align:start position:0% +time and divide by the dimension of + + + align:start position:0% +time and divide by the dimension of +length to get a dimension of + + align:start position:0% + + + + align:start position:0% + +one we Define a new dimensionless + + align:start position:0% +one we Define a new dimensionless + + + align:start position:0% +one we Define a new dimensionless +variable V bar as this dimensionless + + align:start position:0% +variable V bar as this dimensionless + + + align:start position:0% +variable V bar as this dimensionless +version of + + align:start position:0% + + + + align:start position:0% + +V now you try find D + + align:start position:0% +V now you try find D + + + align:start position:0% +V now you try find D +M Bar G bar and + + align:start position:0% +M Bar G bar and + + + align:start position:0% +M Bar G bar and +rowar pause the video + + align:start position:0% + + + + align:start position:0% + +here you should have found that D is D * + + align:start position:0% +here you should have found that D is D * + + + align:start position:0% +here you should have found that D is D * +row over m to the + + align:start position:0% +row over m to the + + + align:start position:0% +row over m to the +1/3 m is + + align:start position:0% +1/3 m is + + + align:start position:0% +1/3 m is +1 G bar is V ^2 over G * row over M the + + align:start position:0% +1 G bar is V ^2 over G * row over M the + + + align:start position:0% +1 G bar is V ^2 over G * row over M the +1/3 and rowar is + + align:start position:0% +1/3 and rowar is + + + align:start position:0% +1/3 and rowar is +one now we can rewrite the equation for + + align:start position:0% +one now we can rewrite the equation for + + + align:start position:0% +one now we can rewrite the equation for +velocity in terms of the new + + align:start position:0% +velocity in terms of the new + + + align:start position:0% +velocity in terms of the new +dimensionless variables it is a new + + align:start position:0% +dimensionless variables it is a new + + + align:start position:0% +dimensionless variables it is a new +function because the variables have been + + align:start position:0% +function because the variables have been + + + align:start position:0% +function because the variables have been +modified notice that V is equal to + + align:start position:0% +modified notice that V is equal to + + + align:start position:0% +modified notice that V is equal to +G this means that V bar and gar are not + + align:start position:0% +G this means that V bar and gar are not + + + align:start position:0% +G this means that V bar and gar are not +independent so our function for V bar + + align:start position:0% +independent so our function for V bar + + + align:start position:0% +independent so our function for V bar +cannot depend on G + + align:start position:0% +cannot depend on G + + + align:start position:0% +cannot depend on G +bar also notice that mbar and rowar are + + align:start position:0% +bar also notice that mbar and rowar are + + + align:start position:0% +bar also notice that mbar and rowar are +both equal to one so our function + + align:start position:0% +both equal to one so our function + + + align:start position:0% +both equal to one so our function +doesn't depend on them + + align:start position:0% +doesn't depend on them + + + align:start position:0% +doesn't depend on them +either this has simplified our + + align:start position:0% +either this has simplified our + + + align:start position:0% +either this has simplified our +relationship V bar is a function of only + + align:start position:0% +relationship V bar is a function of only + + + align:start position:0% +relationship V bar is a function of only +one variable + + align:start position:0% +one variable + + + align:start position:0% +one variable +dbar and remember that dbar is + + align:start position:0% +dbar and remember that dbar is + + + align:start position:0% +dbar and remember that dbar is +dimensionless so it's just a real number + + align:start position:0% +dimensionless so it's just a real number + + + align:start position:0% +dimensionless so it's just a real number +this means that Fe can be any + + align:start position:0% +this means that Fe can be any + + + align:start position:0% +this means that Fe can be any +function the fourth and final step is to + + align:start position:0% +function the fourth and final step is to + + + align:start position:0% +function the fourth and final step is to +rearrange to find a formula for the + + align:start position:0% +rearrange to find a formula for the + + + align:start position:0% +rearrange to find a formula for the +terminal + + align:start position:0% +terminal + + + align:start position:0% +terminal +velocity the key here is that the + + align:start position:0% +velocity the key here is that the + + + align:start position:0% +velocity the key here is that the +equation for the the terminal velocity + + align:start position:0% +equation for the the terminal velocity + + + align:start position:0% +equation for the the terminal velocity +has the correct + + align:start position:0% +has the correct + + + align:start position:0% +has the correct +Dimension and this formula is so General + + align:start position:0% +Dimension and this formula is so General + + + align:start position:0% +Dimension and this formula is so General +that any expression with dimension of + + align:start position:0% +that any expression with dimension of + + + align:start position:0% +that any expression with dimension of +length over time can be written in terms + + align:start position:0% +length over time can be written in terms + + + align:start position:0% +length over time can be written in terms +of this formula by defining fee in + + align:start position:0% +of this formula by defining fee in + + + align:start position:0% +of this formula by defining fee in +different ways let's see + + align:start position:0% +different ways let's see + + + align:start position:0% +different ways let's see +how first create an expression from the + + align:start position:0% +how first create an expression from the + + + align:start position:0% +how first create an expression from the +independent variables that has the same + + align:start position:0% +independent variables that has the same + + + align:start position:0% +independent variables that has the same +Dimension as velocity uh one such + + align:start position:0% +Dimension as velocity uh one such + + + align:start position:0% +Dimension as velocity uh one such +expression is the square root of G * + + align:start position:0% +expression is the square root of G * + + + align:start position:0% +expression is the square root of G * +d by setting the form formula for V + + align:start position:0% +d by setting the form formula for V + + + align:start position:0% +d by setting the form formula for V +equal to theare root of GD we see that + + align:start position:0% +equal to theare root of GD we see that + + + align:start position:0% +equal to theare root of GD we see that +by setting F equal to the identity + + align:start position:0% +by setting F equal to the identity + + + align:start position:0% +by setting F equal to the identity +function f of xals x the two sides of + + align:start position:0% +function f of xals x the two sides of + + + align:start position:0% +function f of xals x the two sides of +the equation can be made + + align:start position:0% +the equation can be made + + + align:start position:0% +the equation can be made +equal and in fact we claim that any + + align:start position:0% +equal and in fact we claim that any + + + align:start position:0% +equal and in fact we claim that any +expression with the correct dimension of + + align:start position:0% +expression with the correct dimension of + + + align:start position:0% +expression with the correct dimension of +length over time created using these + + align:start position:0% +length over time created using these + + + align:start position:0% +length over time created using these +variables can be written in terms of + + align:start position:0% +variables can be written in terms of + + + align:start position:0% +variables can be written in terms of +this formula simply by changing the + + align:start position:0% +this formula simply by changing the + + + align:start position:0% +this formula simply by changing the +definition of + + align:start position:0% +definition of + + + align:start position:0% +definition of +Fe it can be fun to try this this come + + align:start position:0% +Fe it can be fun to try this this come + + + align:start position:0% +Fe it can be fun to try this this come +up with different formulas that have the + + align:start position:0% +up with different formulas that have the + + + align:start position:0% +up with different formulas that have the +correct Dimension you can even add them + + align:start position:0% +correct Dimension you can even add them + + + align:start position:0% +correct Dimension you can even add them +together when you're done then see if + + align:start position:0% +together when you're done then see if + + + align:start position:0% +together when you're done then see if +you can find a way to define fee so that + + align:start position:0% +you can find a way to define fee so that + + + align:start position:0% +you can find a way to define fee so that +our formula is equal to the expression + + align:start position:0% +our formula is equal to the expression + + + align:start position:0% +our formula is equal to the expression +you wrote pause the video + + align:start position:0% + + + + align:start position:0% + +here now you may be concerned because + + align:start position:0% +here now you may be concerned because + + + align:start position:0% +here now you may be concerned because +this formula is not unique we made some + + align:start position:0% +this formula is not unique we made some + + + align:start position:0% +this formula is not unique we made some +choices about how to represent our + + align:start position:0% +choices about how to represent our + + + align:start position:0% +choices about how to represent our +fundamental + + align:start position:0% +fundamental + + + align:start position:0% +fundamental +Dimensions what happens if we make + + align:start position:0% +Dimensions what happens if we make + + + align:start position:0% +Dimensions what happens if we make +different choices + + align:start position:0% + + + + align:start position:0% + +here we chose M L and T this way M was + + align:start position:0% +here we chose M L and T this way M was + + + align:start position:0% +here we chose M L and T this way M was +Little M L was Little D and T was V over + + align:start position:0% +Little M L was Little D and T was V over + + + align:start position:0% +Little M L was Little D and T was V over +G running through the dimensional + + align:start position:0% +G running through the dimensional + + + align:start position:0% +G running through the dimensional +analysis process with this choice of + + align:start position:0% +analysis process with this choice of + + + align:start position:0% +analysis process with this choice of +fundamental Dimensions we obtain an + + align:start position:0% +fundamental Dimensions we obtain an + + + align:start position:0% +fundamental Dimensions we obtain an +equation for v that looks like + + align:start position:0% +equation for v that looks like + + + align:start position:0% +equation for v that looks like +this to see that these two formulas are + + align:start position:0% +this to see that these two formulas are + + + align:start position:0% +this to see that these two formulas are +equivalent we set the arguments under + + align:start position:0% +equivalent we set the arguments under + + + align:start position:0% +equivalent we set the arguments under +the square root equal and find that we + + align:start position:0% +the square root equal and find that we + + + align:start position:0% +the square root equal and find that we +can express f as a function of + + align:start position:0% + + + + align:start position:0% + +s so any formula with the correct + + align:start position:0% +s so any formula with the correct + + + align:start position:0% +s so any formula with the correct +Dimension can be expressed by this + + align:start position:0% +Dimension can be expressed by this + + + align:start position:0% +Dimension can be expressed by this +general + + align:start position:0% +general + + + align:start position:0% +general +formula and this general formula works + + align:start position:0% +formula and this general formula works + + + align:start position:0% +formula and this general formula works +for any Rover on any Planet whose + + align:start position:0% +for any Rover on any Planet whose + + + align:start position:0% +for any Rover on any Planet whose +terminal velocity through the atmosphere + + align:start position:0% +terminal velocity through the atmosphere + + + align:start position:0% +terminal velocity through the atmosphere +depends on the same variables because + + align:start position:0% +depends on the same variables because + + + align:start position:0% +depends on the same variables because +it's a general + + align:start position:0% + + + + align:start position:0% + +law of course we still don't know what + + align:start position:0% +law of course we still don't know what + + + align:start position:0% +law of course we still don't know what +this function fee is in order to find + + align:start position:0% +this function fee is in order to find + + + align:start position:0% +this function fee is in order to find +fee we can fit experimental data from + + align:start position:0% +fee we can fit experimental data from + + + align:start position:0% +fee we can fit experimental data from +any planet for example + + align:start position:0% +any planet for example + + + align:start position:0% +any planet for example +Earth on Earth we know the gravity and + + align:start position:0% +Earth on Earth we know the gravity and + + + align:start position:0% +Earth on Earth we know the gravity and +Atmospheric density we can specify the + + align:start position:0% +Atmospheric density we can specify the + + + align:start position:0% +Atmospheric density we can specify the +mass of a test Rover to be + + align:start position:0% +mass of a test Rover to be + + + align:start position:0% +mass of a test Rover to be + + align:start position:0% + + + align:start position:0% +kg then we might set up Earthbound + + align:start position:0% +kg then we might set up Earthbound + + + align:start position:0% +kg then we might set up Earthbound +experiments by varying the canopy + + align:start position:0% +experiments by varying the canopy + + + align:start position:0% +experiments by varying the canopy +diameter of a parachute between 1 M to + + align:start position:0% +diameter of a parachute between 1 M to + + + align:start position:0% +diameter of a parachute between 1 M to +20 M and measuring the terminal + + align:start position:0% +20 M and measuring the terminal + + + align:start position:0% +20 M and measuring the terminal +velocity for example suppose we obtain + + align:start position:0% +velocity for example suppose we obtain + + + align:start position:0% +velocity for example suppose we obtain +the following data on + + align:start position:0% + + + + align:start position:0% + +Earth then we could convert this data to + + align:start position:0% +Earth then we could convert this data to + + + align:start position:0% +Earth then we could convert this data to +the dbar V bar axes by scaling the + + align:start position:0% +the dbar V bar axes by scaling the + + + align:start position:0% +the dbar V bar axes by scaling the +variables V and D according to the Earth + + align:start position:0% +variables V and D according to the Earth + + + align:start position:0% +variables V and D according to the Earth +values for the mass gravity and at + + align:start position:0% +values for the mass gravity and at + + + align:start position:0% +values for the mass gravity and at +atmospheric + + align:start position:0% +atmospheric + + + align:start position:0% +atmospheric +density we can fit this data to some + + align:start position:0% +density we can fit this data to some + + + align:start position:0% +density we can fit this data to some +best fit curve and this best fit curve + + align:start position:0% +best fit curve and this best fit curve + + + align:start position:0% +best fit curve and this best fit curve +is our best approximation to that + + align:start position:0% +is our best approximation to that + + + align:start position:0% +is our best approximation to that +function + + align:start position:0% +function + + + align:start position:0% +function +Fe now that we have Fe we can transform + + align:start position:0% +Fe now that we have Fe we can transform + + + align:start position:0% +Fe now that we have Fe we can transform +the axes again to represent the canopy + + align:start position:0% +the axes again to represent the canopy + + + align:start position:0% +the axes again to represent the canopy +diameter and terminal velocity on + + align:start position:0% +diameter and terminal velocity on + + + align:start position:0% +diameter and terminal velocity on +Mars This is done by converting V bar + + align:start position:0% +Mars This is done by converting V bar + + + align:start position:0% +Mars This is done by converting V bar +and D Bar to V and D by scaling + + align:start position:0% +and D Bar to V and D by scaling + + + align:start position:0% +and D Bar to V and D by scaling +according to known values of the gravity + + align:start position:0% +according to known values of the gravity + + + align:start position:0% +according to known values of the gravity +atmospheric density and mass of the + + align:start position:0% +atmospheric density and mass of the + + + align:start position:0% +atmospheric density and mass of the +Rover on + + align:start position:0% +Rover on + + + align:start position:0% +Rover on +Mars to find the diameter we find the + + align:start position:0% +Mars to find the diameter we find the + + + align:start position:0% +Mars to find the diameter we find the +point on the V axis that corresponds to + + align:start position:0% +point on the V axis that corresponds to + + + align:start position:0% +point on the V axis that corresponds to +a terminal velocity of 90 + + align:start position:0% +a terminal velocity of 90 + + + align:start position:0% +a terminal velocity of 90 +m/s and use our curve to determine the + + align:start position:0% +m/s and use our curve to determine the + + + align:start position:0% +m/s and use our curve to determine the +diameter that corresponds to this + + align:start position:0% +diameter that corresponds to this + + + align:start position:0% +diameter that corresponds to this +terminal + + align:start position:0% +terminal + + + align:start position:0% +terminal +velocity now we have the specification + + align:start position:0% +velocity now we have the specification + + + align:start position:0% +velocity now we have the specification +we need to design the size of our + + align:start position:0% +we need to design the size of our + + + align:start position:0% +we need to design the size of our +parachute to be used on The Descent to + + align:start position:0% +parachute to be used on The Descent to + + + align:start position:0% +parachute to be used on The Descent to +Mars + + align:start position:0% + + + + align:start position:0% + +in this example we use dimensional + + align:start position:0% +in this example we use dimensional + + + align:start position:0% +in this example we use dimensional +analysis to restrict the possible form + + align:start position:0% +analysis to restrict the possible form + + + align:start position:0% +analysis to restrict the possible form +of a function describing the terminal + + align:start position:0% +of a function describing the terminal + + + align:start position:0% +of a function describing the terminal +velocity of the Mars rover as a function + + align:start position:0% +velocity of the Mars rover as a function + + + align:start position:0% +velocity of the Mars rover as a function +of the parachute canopy diameter + + align:start position:0% +of the parachute canopy diameter + + + align:start position:0% +of the parachute canopy diameter +gravitational acceleration atmospheric + + align:start position:0% +gravitational acceleration atmospheric + + + align:start position:0% +gravitational acceleration atmospheric +density and the mass of the + + align:start position:0% +density and the mass of the + + + align:start position:0% +density and the mass of the +Rover this allowed us to design a + + align:start position:0% +Rover this allowed us to design a + + + align:start position:0% +Rover this allowed us to design a +parachute for use on Mars based on + + align:start position:0% +parachute for use on Mars based on + + + align:start position:0% +parachute for use on Mars based on +Earthbound + + align:start position:0% + + + + align:start position:0% + +experiments in general the process of + + align:start position:0% +experiments in general the process of + + + align:start position:0% +experiments in general the process of +dimensional analysis involves + + align:start position:0% +dimensional analysis involves + + + align:start position:0% +dimensional analysis involves +one identifying the dependent variable + + align:start position:0% +one identifying the dependent variable + + + align:start position:0% +one identifying the dependent variable +and independent + + align:start position:0% +and independent + + + align:start position:0% +and independent +variables two expressing the relevant + + align:start position:0% +variables two expressing the relevant + + + align:start position:0% +variables two expressing the relevant +fundamental dimensions in terms of the + + align:start position:0% +fundamental dimensions in terms of the + + + align:start position:0% +fundamental dimensions in terms of the +variables found in step + + align:start position:0% +variables found in step + + + align:start position:0% +variables found in step +one three generating dimensionless + + align:start position:0% +one three generating dimensionless + + + align:start position:0% +one three generating dimensionless +expressions for all the variables using + + align:start position:0% +expressions for all the variables using + + + align:start position:0% +expressions for all the variables using +expressions from step two four producing + + align:start position:0% +expressions from step two four producing + + + align:start position:0% +expressions from step two four producing +a functional relationship between the + + align:start position:0% +a functional relationship between the + + + align:start position:0% +a functional relationship between the +dimensionless dependent variable in + + align:start position:0% +dimensionless dependent variable in + + + align:start position:0% +dimensionless dependent variable in +terms of the remaining independent + + align:start position:0% +terms of the remaining independent + + + align:start position:0% +terms of the remaining independent +dimensionless + + align:start position:0% +dimensionless + + + align:start position:0% +dimensionless +expressions five rearranging to + + align:start position:0% +expressions five rearranging to + + + align:start position:0% +expressions five rearranging to +determine a formula for the variable of + + align:start position:0% +determine a formula for the variable of + + + align:start position:0% +determine a formula for the variable of +interest and six performing experiments + + align:start position:0% +interest and six performing experiments + + + align:start position:0% +interest and six performing experiments +to determine the form of the general + + align:start position:0% +to determine the form of the general + + + align:start position:0% +to determine the form of the general +real valued function that appears in + + align:start position:0% +real valued function that appears in + + + align:start position:0% +real valued function that appears in +that + + align:start position:0% +that + + + align:start position:0% +that +formula we've just shown you a very + + align:start position:0% +formula we've just shown you a very + + + align:start position:0% +formula we've just shown you a very +powerful tool which can save you a lot + + align:start position:0% +powerful tool which can save you a lot + + + align:start position:0% +powerful tool which can save you a lot +of time so the next time you're faced + + align:start position:0% +of time so the next time you're faced + + + align:start position:0% +of time so the next time you're faced +with a difficult challenge you might + + align:start position:0% +with a difficult challenge you might + + + align:start position:0% +with a difficult challenge you might +just want to try dimensional + + align:start position:0% + + + + align:start position:0% + +analysis + + align:start position:0% + + + + align:start position:0% + +[Music] \ No newline at end of file diff --git a/58B5dEJReQ8.txt b/58B5dEJReQ8.txt new file mode 100644 index 0000000000000000000000000000000000000000..ac311d7e7025c5bd67e52e5399bd69ce1f07d2c8 --- /dev/null +++ b/58B5dEJReQ8.txt @@ -0,0 +1,10748 @@ +align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +so let's continue our discussion of + + align:start position:0% +so let's continue our discussion of + + + align:start position:0% +so let's continue our discussion of +uh + + align:start position:0% + + + + align:start position:0% + +norm spaces and bonnet spaces so last + + align:start position:0% +norm spaces and bonnet spaces so last + + + align:start position:0% +norm spaces and bonnet spaces so last +time + + align:start position:0% +time + + + align:start position:0% +time +i introduced the space of bounded linear + + align:start position:0% +i introduced the space of bounded linear + + + align:start position:0% +i introduced the space of bounded linear +operators from one + + align:start position:0% +operators from one + + + align:start position:0% +operators from one +uh norm space from another and we saw + + align:start position:0% +uh norm space from another and we saw + + + align:start position:0% +uh norm space from another and we saw +that when + + align:start position:0% +that when + + + align:start position:0% +that when +the target is a bonus base + + align:start position:0% +the target is a bonus base + + + align:start position:0% +the target is a bonus base +then this space of bounded linear + + align:start position:0% +then this space of bounded linear + + + align:start position:0% +then this space of bounded linear +operators is also a bonus space + + align:start position:0% + + + + align:start position:0% + +so now + + align:start position:0% +so now + + + align:start position:0% +so now +we'll look at another + + align:start position:0% + + + + align:start position:0% + +example of a way to obtain a norm space + + align:start position:0% +example of a way to obtain a norm space + + + align:start position:0% +example of a way to obtain a norm space +from a given norm space so + + align:start position:0% +from a given norm space so + + + align:start position:0% +from a given norm space so +i'll be talking about + + align:start position:0% + + + + align:start position:0% + +subspaces + + align:start position:0% + + + + align:start position:0% + +and quotients + + align:start position:0% + + + + align:start position:0% + +all right + + align:start position:0% + + + + align:start position:0% + +so let me just recall + + align:start position:0% +so let me just recall + + + align:start position:0% +so let me just recall +briefly what a subspace is you should + + align:start position:0% +briefly what a subspace is you should + + + align:start position:0% +briefly what a subspace is you should +remember this from linear algebra v will + + align:start position:0% +remember this from linear algebra v will + + + align:start position:0% +remember this from linear algebra v will +always be + + align:start position:0% +always be + + + align:start position:0% +always be +at least a vector space + + align:start position:0% +at least a vector space + + + align:start position:0% +at least a vector space +usually a norm's + + align:start position:0% +usually a norm's + + + align:start position:0% +usually a norm's +space so we say + + align:start position:0% +space so we say + + + align:start position:0% +space so we say +a subset and i've been using this + + align:start position:0% +a subset and i've been using this + + + align:start position:0% +a subset and i've been using this +notation it doesn't mean strict + + align:start position:0% +notation it doesn't mean strict + + + align:start position:0% +notation it doesn't mean strict +uh + + align:start position:0% +uh + + + align:start position:0% +uh +a strict subset i'm just kind of used to + + align:start position:0% +a strict subset i'm just kind of used to + + + align:start position:0% +a strict subset i'm just kind of used to +using this notation from + + align:start position:0% +using this notation from + + + align:start position:0% +using this notation from +18 100 a in the textbook use this + + align:start position:0% +18 100 a in the textbook use this + + + align:start position:0% +18 100 a in the textbook use this +notation for + + align:start position:0% +notation for + + + align:start position:0% +notation for +just being a subset not necessarily a + + align:start position:0% +just being a subset not necessarily a + + + align:start position:0% +just being a subset not necessarily a +strict subset so + + align:start position:0% +strict subset so + + + align:start position:0% +strict subset so +quick uh + + align:start position:0% +quick uh + + + align:start position:0% +quick uh +note about that so + + align:start position:0% +note about that so + + + align:start position:0% +note about that so +a subset of v is + + align:start position:0% + + + + align:start position:0% + +a subspace if + + align:start position:0% +a subspace if + + + align:start position:0% +a subspace if +raw + + align:start position:0% + + + + align:start position:0% + +elements two elements in the + + align:start position:0% +elements two elements in the + + + align:start position:0% +elements two elements in the +field of scalars + + align:start position:0% + + + + align:start position:0% + +and elements in w + + align:start position:0% + + + + align:start position:0% + +their linear combination + + align:start position:0% + + + + align:start position:0% + +is also in w okay so w is closed + + align:start position:0% +is also in w okay so w is closed + + + align:start position:0% +is also in w okay so w is closed +undertaking linear combinations + + align:start position:0% + + + + align:start position:0% + +and so it's + + align:start position:0% +and so it's + + + align:start position:0% +and so it's +quite easy to prove and i'll leave this + + align:start position:0% +quite easy to prove and i'll leave this + + + align:start position:0% +quite easy to prove and i'll leave this +to you that + + align:start position:0% + + + + align:start position:0% + +a subspace + + align:start position:0% +a subspace + + + align:start position:0% +a subspace +of a + + align:start position:0% +of a + + + align:start position:0% +of a +normed uh + + align:start position:0% +normed uh + + + align:start position:0% +normed uh +space of a of a bonus base sorry + + align:start position:0% + + + + align:start position:0% + +is itself a bonus space + + align:start position:0% +is itself a bonus space + + + align:start position:0% +is itself a bonus space +meaning it's complete with respect to + + align:start position:0% +meaning it's complete with respect to + + + align:start position:0% +meaning it's complete with respect to +the norm + + align:start position:0% +the norm + + + align:start position:0% +the norm +it inherits from v + + align:start position:0% + + + + align:start position:0% + +it's a bonus base if and only if + + align:start position:0% + + + + align:start position:0% + +it's a closed subset of v with respect + + align:start position:0% +it's a closed subset of v with respect + + + align:start position:0% +it's a closed subset of v with respect +to + + align:start position:0% +to + + + align:start position:0% +to +uh this metric we have induced by the + + align:start position:0% +uh this metric we have induced by the + + + align:start position:0% +uh this metric we have induced by the +norm + + align:start position:0% +norm + + + align:start position:0% +norm +okay + + align:start position:0% + + + + align:start position:0% + +i mean you know you can let me talk your + + align:start position:0% +i mean you know you can let me talk your + + + align:start position:0% +i mean you know you can let me talk your +our way through it real quick + + align:start position:0% +our way through it real quick + + + align:start position:0% +our way through it real quick +uh assuming w is a bonus space we want + + align:start position:0% +uh assuming w is a bonus space we want + + + align:start position:0% +uh assuming w is a bonus space we want +to show w is also a + + align:start position:0% +to show w is also a + + + align:start position:0% +to show w is also a +closed subset of v so that means you + + align:start position:0% +closed subset of v so that means you + + + align:start position:0% +closed subset of v so that means you +need to show for example that + + align:start position:0% +need to show for example that + + + align:start position:0% +need to show for example that +one equivalent way of showing this is + + align:start position:0% +one equivalent way of showing this is + + + align:start position:0% +one equivalent way of showing this is +that every sequence that converges + + align:start position:0% +that every sequence that converges + + + align:start position:0% +that every sequence that converges +every sequence of elements from w that + + align:start position:0% +every sequence of elements from w that + + + align:start position:0% +every sequence of elements from w that +converges converges to an element of w + + align:start position:0% +converges converges to an element of w + + + align:start position:0% +converges converges to an element of w +okay + + align:start position:0% +okay + + + align:start position:0% +okay +now + + align:start position:0% +now + + + align:start position:0% +now +uh take a sequence in w that converges + + align:start position:0% +uh take a sequence in w that converges + + + align:start position:0% +uh take a sequence in w that converges +to some element in v + + align:start position:0% +to some element in v + + + align:start position:0% +to some element in v +we now want to show that elements in w + + align:start position:0% +we now want to show that elements in w + + + align:start position:0% +we now want to show that elements in w +then that sequence converges + + align:start position:0% +then that sequence converges + + + align:start position:0% +then that sequence converges +in w or is cauchy in w + + align:start position:0% +in w or is cauchy in w + + + align:start position:0% +in w or is cauchy in w +and since w is a bonus space there must + + align:start position:0% +and since w is a bonus space there must + + + align:start position:0% +and since w is a bonus space there must +be an element in w which it converges to + + align:start position:0% +be an element in w which it converges to + + + align:start position:0% +be an element in w which it converges to +and therefore by uniqueness of limits + + align:start position:0% +and therefore by uniqueness of limits + + + align:start position:0% +and therefore by uniqueness of limits +that limit + + align:start position:0% +that limit + + + align:start position:0% +that limit +of that original sequence must lie in w + + align:start position:0% +of that original sequence must lie in w + + + align:start position:0% +of that original sequence must lie in w +okay + + align:start position:0% + + + + align:start position:0% + +and now going the opposite direction + + align:start position:0% +and now going the opposite direction + + + align:start position:0% +and now going the opposite direction +assuming + + align:start position:0% +assuming + + + align:start position:0% +assuming +the subset the subspace is closed + + align:start position:0% +the subset the subspace is closed + + + align:start position:0% +the subset the subspace is closed +you want to show that + + align:start position:0% +you want to show that + + + align:start position:0% +you want to show that +now this subspace is a banach space + + align:start position:0% +now this subspace is a banach space + + + align:start position:0% +now this subspace is a banach space +meaning it's complete + + align:start position:0% +meaning it's complete + + + align:start position:0% +meaning it's complete +well let's take a koshy sequence in w + + align:start position:0% +well let's take a koshy sequence in w + + + align:start position:0% +well let's take a koshy sequence in w +this is also a koshi sequence in v + + align:start position:0% +this is also a koshi sequence in v + + + align:start position:0% +this is also a koshi sequence in v +therefore it has a limit + + align:start position:0% +therefore it has a limit + + + align:start position:0% +therefore it has a limit +this limit has to be in w since w is + + align:start position:0% +this limit has to be in w since w is + + + align:start position:0% +this limit has to be in w since w is +closed and therefore every cochise + + align:start position:0% +closed and therefore every cochise + + + align:start position:0% +closed and therefore every cochise +sequence in w has a limit in w and + + align:start position:0% +sequence in w has a limit in w and + + + align:start position:0% +sequence in w has a limit in w and +therefore w is a bonus face + + align:start position:0% +therefore w is a bonus face + + + align:start position:0% +therefore w is a bonus face +okay so i didn't write out what uh i + + align:start position:0% +okay so i didn't write out what uh i + + + align:start position:0% +okay so i didn't write out what uh i +didn't write out the details but we + + align:start position:0% +didn't write out the details but we + + + align:start position:0% +didn't write out the details but we +talked our way through it + + align:start position:0% + + + + align:start position:0% + +so let me uh since we're taking a trip + + align:start position:0% +so let me uh since we're taking a trip + + + align:start position:0% +so let me uh since we're taking a trip +down memory lane + + align:start position:0% +down memory lane + + + align:start position:0% +down memory lane +i just recalled what a subspace is now + + align:start position:0% +i just recalled what a subspace is now + + + align:start position:0% +i just recalled what a subspace is now +given a subspace we can + + align:start position:0% +given a subspace we can + + + align:start position:0% +given a subspace we can +obtain a another vector space uh + + align:start position:0% +obtain a another vector space uh + + + align:start position:0% +obtain a another vector space uh +with the data of the the space and the + + align:start position:0% +with the data of the the space and the + + + align:start position:0% +with the data of the the space and the +subspace called the quotient so let me + + align:start position:0% +subspace called the quotient so let me + + + align:start position:0% +subspace called the quotient so let me +recall the quotient + + align:start position:0% + + + + align:start position:0% + +this is about + + align:start position:0% + + + + align:start position:0% + +briefly recalling what the quotient is + + align:start position:0% +briefly recalling what the quotient is + + + align:start position:0% +briefly recalling what the quotient is +so + + align:start position:0% + + + + align:start position:0% + +let's take a subspace of v + + align:start position:0% + + + + align:start position:0% + +we define + + align:start position:0% +we define + + + align:start position:0% +we define +an equivalence relation + + align:start position:0% + + + + align:start position:0% + +on b + + align:start position:0% +on b + + + align:start position:0% +on b +by + + align:start position:0% +by + + + align:start position:0% +by +saying that + + align:start position:0% + + + + align:start position:0% + +v is + + align:start position:0% +v is + + + align:start position:0% +v is +related to v prime + + align:start position:0% +related to v prime + + + align:start position:0% +related to v prime +if and only if + + align:start position:0% +if and only if + + + align:start position:0% +if and only if +v minus v prime + + align:start position:0% +v minus v prime + + + align:start position:0% +v minus v prime +is in + + align:start position:0% +is in + + + align:start position:0% +is in +w okay + + align:start position:0% +w okay + + + align:start position:0% +w okay +now + + align:start position:0% + + + + align:start position:0% + +what do i mean by equivalence relation + + align:start position:0% + + + + align:start position:0% + +v is always related to v because the + + align:start position:0% +v is always related to v because the + + + align:start position:0% +v is always related to v because the +difference of v is equal to 0 which is + + align:start position:0% +difference of v is equal to 0 which is + + + align:start position:0% +difference of v is equal to 0 which is +an element of w because w is a subspace + + align:start position:0% +an element of w because w is a subspace + + + align:start position:0% +an element of w because w is a subspace +and therefore + + align:start position:0% + + + + align:start position:0% + +a + + align:start position:0% +a + + + align:start position:0% +a +vector space in its own right + + align:start position:0% + + + + align:start position:0% + +if v is related to v prime then this + + align:start position:0% +if v is related to v prime then this + + + align:start position:0% +if v is related to v prime then this +impr implies v prime is related to v + + align:start position:0% +impr implies v prime is related to v + + + align:start position:0% +impr implies v prime is related to v +simply because we again if this is in w + + align:start position:0% +simply because we again if this is in w + + + align:start position:0% +simply because we again if this is in w +then its minus is also in w + + align:start position:0% +then its minus is also in w + + + align:start position:0% +then its minus is also in w +and + + align:start position:0% +and + + + align:start position:0% +and +uh + + align:start position:0% +uh + + + align:start position:0% +uh +this is reflexivity + + align:start position:0% +this is reflexivity + + + align:start position:0% +this is reflexivity +and then we also have + + align:start position:0% +and then we also have + + + align:start position:0% +and then we also have +transitivity that if v is related + + align:start position:0% +transitivity that if v is related + + + align:start position:0% +transitivity that if v is related +to v prime and v is related v prime is + + align:start position:0% +to v prime and v is related v prime is + + + align:start position:0% +to v prime and v is related v prime is +related to v double prime + + align:start position:0% +related to v double prime + + + align:start position:0% +related to v double prime +then v is related to v + + align:start position:0% +then v is related to v + + + align:start position:0% +then v is related to v +double prime + + align:start position:0% + + + + align:start position:0% + +okay just simply take v minus v double + + align:start position:0% +okay just simply take v minus v double + + + align:start position:0% +okay just simply take v minus v double +prime and add and subtract v prime + + align:start position:0% +prime and add and subtract v prime + + + align:start position:0% +prime and add and subtract v prime +then you obtain the sum of two elements + + align:start position:0% +then you obtain the sum of two elements + + + align:start position:0% +then you obtain the sum of two elements +in w which must be in w so this is an + + align:start position:0% +in w which must be in w so this is an + + + align:start position:0% +in w which must be in w so this is an +equivalence relation + + align:start position:0% +equivalence relation + + + align:start position:0% +equivalence relation +and + + align:start position:0% + + + + align:start position:0% + +so then + + align:start position:0% + + + + align:start position:0% + +we uh + + align:start position:0% + + + + align:start position:0% + +to find the equivalence class of v + + align:start position:0% +to find the equivalence class of v + + + align:start position:0% +to find the equivalence class of v +this is the set of all v prime and v + + align:start position:0% +this is the set of all v prime and v + + + align:start position:0% +this is the set of all v prime and v +such that + + align:start position:0% +such that + + + align:start position:0% +such that +uh v is + + align:start position:0% +uh v is + + + align:start position:0% +uh v is +v prime is related to v + + align:start position:0% + + + + align:start position:0% + +and then we define a new set v + + align:start position:0% +and then we define a new set v + + + align:start position:0% +and then we define a new set v +mod + + align:start position:0% + + + + align:start position:0% + +w + + align:start position:0% +w + + + align:start position:0% +w +to be the set of all equivalence classes + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +and instead of writing the equivalence + + align:start position:0% +and instead of writing the equivalence + + + align:start position:0% +and instead of writing the equivalence +class of v we typically write + + align:start position:0% + + + + align:start position:0% + +the plus w + + align:start position:0% + + + + align:start position:0% + +instead of the equivalence class of v + + align:start position:0% +instead of the equivalence class of v + + + align:start position:0% +instead of the equivalence class of v +okay so you think of these + + align:start position:0% +okay so you think of these + + + align:start position:0% +okay so you think of these +of the equivalence class of v as being v + + align:start position:0% +of the equivalence class of v as being v + + + align:start position:0% +of the equivalence class of v as being v +plus kind of all elements of w + + align:start position:0% +plus kind of all elements of w + + + align:start position:0% +plus kind of all elements of w +okay + + align:start position:0% +okay + + + align:start position:0% +okay +or two + + align:start position:0% +or two + + + align:start position:0% +or two +uh + + align:start position:0% +uh + + + align:start position:0% +uh +elements + + align:start position:0% +elements + + + align:start position:0% +elements +are the same if they differ by an + + align:start position:0% +are the same if they differ by an + + + align:start position:0% +are the same if they differ by an +element of w + + align:start position:0% +element of w + + + align:start position:0% +element of w +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so this is a set but we it becomes a + + align:start position:0% +so this is a set but we it becomes a + + + align:start position:0% +so this is a set but we it becomes a +vector space + + align:start position:0% + + + + align:start position:0% + +with the skate with the uh + + align:start position:0% +with the skate with the uh + + + align:start position:0% +with the skate with the uh +addition and scalar multiplication + + align:start position:0% +addition and scalar multiplication + + + align:start position:0% +addition and scalar multiplication +operations defined in a kind of natural + + align:start position:0% +operations defined in a kind of natural + + + align:start position:0% +operations defined in a kind of natural +way + + align:start position:0% +way + + + align:start position:0% +way +with v1 + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +scalar multiplication is just + + align:start position:0% +scalar multiplication is just + + + align:start position:0% +scalar multiplication is just +the equivalence class + + align:start position:0% +the equivalence class + + + align:start position:0% +the equivalence class +given by lambda times v okay + + align:start position:0% +given by lambda times v okay + + + align:start position:0% +given by lambda times v okay +now you know + + align:start position:0% +now you know + + + align:start position:0% +now you know +you have to take a second and make sure + + align:start position:0% +you have to take a second and make sure + + + align:start position:0% +you have to take a second and make sure +that these operations are well defined + + align:start position:0% +that these operations are well defined + + + align:start position:0% +that these operations are well defined +which i'm sure you did in linear algebra + + align:start position:0% +which i'm sure you did in linear algebra + + + align:start position:0% +which i'm sure you did in linear algebra +what do i mean by well-defined well + + align:start position:0% +what do i mean by well-defined well + + + align:start position:0% +what do i mean by well-defined well +these are two equivalence classes so if + + align:start position:0% +these are two equivalence classes so if + + + align:start position:0% +these are two equivalence classes so if +i take two other representatives say v + + align:start position:0% +i take two other representatives say v + + + align:start position:0% +i take two other representatives say v +one prime and v two prime do i get the + + align:start position:0% +one prime and v two prime do i get the + + + align:start position:0% +one prime and v two prime do i get the +same equivalence class + + align:start position:0% +same equivalence class + + + align:start position:0% +same equivalence class +uh + + align:start position:0% +uh + + + align:start position:0% +uh +as i did with the un prime meaning does + + align:start position:0% +as i did with the un prime meaning does + + + align:start position:0% +as i did with the un prime meaning does +v one prime plus v two prime plus w + + align:start position:0% +v one prime plus v two prime plus w + + + align:start position:0% +v one prime plus v two prime plus w +uh the same equivalence class as v one + + align:start position:0% +uh the same equivalence class as v one + + + align:start position:0% +uh the same equivalence class as v one +plus v two + + align:start position:0% +plus v two + + + align:start position:0% +plus v two +plus w and uh this is not too hard to + + align:start position:0% +plus w and uh this is not too hard to + + + align:start position:0% +plus w and uh this is not too hard to +say or to see + + align:start position:0% +say or to see + + + align:start position:0% +say or to see +okay + + align:start position:0% + + + + align:start position:0% + +all right + + align:start position:0% +all right + + + align:start position:0% +all right +so + + align:start position:0% +so + + + align:start position:0% +so +uh + + align:start position:0% + + + + align:start position:0% + +so v mod w which is typically uh how you + + align:start position:0% +so v mod w which is typically uh how you + + + align:start position:0% +so v mod w which is typically uh how you +pronounce this v slash w v mod w is a + + align:start position:0% +pronounce this v slash w v mod w is a + + + align:start position:0% +pronounce this v slash w v mod w is a +vector space + + align:start position:0% +vector space + + + align:start position:0% +vector space +and uh + + align:start position:0% +and uh + + + align:start position:0% +and uh +so + + align:start position:0% + + + + align:start position:0% + +note uh we can identify w + + align:start position:0% +note uh we can identify w + + + align:start position:0% +note uh we can identify w +so just the + + align:start position:0% +so just the + + + align:start position:0% +so just the +set w + + align:start position:0% +set w + + + align:start position:0% +set w +uh with the equivalence class zero plus + + align:start position:0% +uh with the equivalence class zero plus + + + align:start position:0% +uh with the equivalence class zero plus +w + + align:start position:0% +w + + + align:start position:0% +w +which + + align:start position:0% +which + + + align:start position:0% +which +um + + align:start position:0% +um + + + align:start position:0% +um +is also equal to w plus little w plus + + align:start position:0% +is also equal to w plus little w plus + + + align:start position:0% +is also equal to w plus little w plus +capital w + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +so um + + align:start position:0% + + + + align:start position:0% + +when we first started talking about + + align:start position:0% +when we first started talking about + + + align:start position:0% +when we first started talking about +norms we + + align:start position:0% +norms we + + + align:start position:0% +norms we +i also introduced what was called a + + align:start position:0% +i also introduced what was called a + + + align:start position:0% +i also introduced what was called a +seminorm now a semi norm recall + + align:start position:0% +seminorm now a semi norm recall + + + align:start position:0% +seminorm now a semi norm recall +satisfied + + align:start position:0% +satisfied + + + align:start position:0% +satisfied +not all three properties of norm + + align:start position:0% +not all three properties of norm + + + align:start position:0% +not all three properties of norm +satisfied it satisfies + + align:start position:0% +satisfied it satisfies + + + align:start position:0% +satisfied it satisfies +homogeneity meaning how scalars pull out + + align:start position:0% +homogeneity meaning how scalars pull out + + + align:start position:0% +homogeneity meaning how scalars pull out +and also the triangle + + align:start position:0% +and also the triangle + + + align:start position:0% +and also the triangle +inequality but it didn't satisfy + + align:start position:0% +inequality but it didn't satisfy + + + align:start position:0% +inequality but it didn't satisfy +positive definiteness meaning + + align:start position:0% +positive definiteness meaning + + + align:start position:0% +positive definiteness meaning +uh the semi norm + + align:start position:0% +uh the semi norm + + + align:start position:0% +uh the semi norm +could be zero for certain non-zero + + align:start position:0% +could be zero for certain non-zero + + + align:start position:0% +could be zero for certain non-zero +vectors + + align:start position:0% +vectors + + + align:start position:0% +vectors +okay + + align:start position:0% +okay + + + align:start position:0% +okay +um + + align:start position:0% + + + + align:start position:0% + +you know how + + align:start position:0% +you know how + + + align:start position:0% +you know how +how could that arise how could a + + align:start position:0% +how could that arise how could a + + + align:start position:0% +how could that arise how could a +semi-normal rise well think of taking + + align:start position:0% +semi-normal rise well think of taking + + + align:start position:0% +semi-normal rise well think of taking +um + + align:start position:0% +um + + + align:start position:0% +um +the maximum of the derivative of a + + align:start position:0% +the maximum of the derivative of a + + + align:start position:0% +the maximum of the derivative of a +function + + align:start position:0% +function + + + align:start position:0% +function +right as being a norm + + align:start position:0% +right as being a norm + + + align:start position:0% +right as being a norm +or as being a potential norm + + align:start position:0% +or as being a potential norm + + + align:start position:0% +or as being a potential norm +then + + align:start position:0% +then + + + align:start position:0% +then +uh it satisfies um homogeneity and a + + align:start position:0% +uh it satisfies um homogeneity and a + + + align:start position:0% +uh it satisfies um homogeneity and a +triangle inequality + + align:start position:0% +triangle inequality + + + align:start position:0% +triangle inequality +um but it is not + + align:start position:0% +um but it is not + + + align:start position:0% +um but it is not +uh + + align:start position:0% +uh + + + align:start position:0% +uh +a norm because the derivative of + + align:start position:0% +a norm because the derivative of + + + align:start position:0% +a norm because the derivative of +constant functions + + align:start position:0% +constant functions + + + align:start position:0% +constant functions +is zero + + align:start position:0% +is zero + + + align:start position:0% +is zero +but constant functions aren't + + align:start position:0% +but constant functions aren't + + + align:start position:0% +but constant functions aren't +identically zero if you think of them as + + align:start position:0% +identically zero if you think of them as + + + align:start position:0% +identically zero if you think of them as +elements of say the space of + + align:start position:0% +elements of say the space of + + + align:start position:0% +elements of say the space of +continuously differentiable functions + + align:start position:0% +continuously differentiable functions + + + align:start position:0% +continuously differentiable functions +okay um but this next theorem says that + + align:start position:0% +okay um but this next theorem says that + + + align:start position:0% +okay um but this next theorem says that +if you mod out by + + align:start position:0% +if you mod out by + + + align:start position:0% +if you mod out by +the elements in a vector space + + align:start position:0% +the elements in a vector space + + + align:start position:0% +the elements in a vector space +on which the semi norm is zero + + align:start position:0% +on which the semi norm is zero + + + align:start position:0% +on which the semi norm is zero +then you get + + align:start position:0% +then you get + + + align:start position:0% +then you get +essentially a norm space where the norm + + align:start position:0% +essentially a norm space where the norm + + + align:start position:0% +essentially a norm space where the norm +is given by the semi-norm so if you mod + + align:start position:0% +is given by the semi-norm so if you mod + + + align:start position:0% +is given by the semi-norm so if you mod +out by + + align:start position:0% +out by + + + align:start position:0% +out by +you know the elements with zero semi + + align:start position:0% +you know the elements with zero semi + + + align:start position:0% +you know the elements with zero semi +norm you get a actual norm space + + align:start position:0% +norm you get a actual norm space + + + align:start position:0% +norm you get a actual norm space +the statement is let + + align:start position:0% + + + + align:start position:0% + +let's take a semi-norm + + align:start position:0% + + + + align:start position:0% + +on a vector space v + + align:start position:0% + + + + align:start position:0% + +then + + align:start position:0% +then + + + align:start position:0% +then +we define e + + align:start position:0% + + + + align:start position:0% + +to be the set of all v and capital v + + align:start position:0% +to be the set of all v and capital v + + + align:start position:0% +to be the set of all v and capital v +such that + + align:start position:0% +such that + + + align:start position:0% +such that +this + + align:start position:0% +this + + + align:start position:0% +this +semi-norm + + align:start position:0% + + + + align:start position:0% + +of these vectors is zero + + align:start position:0% + + + + align:start position:0% + +this is + + align:start position:0% + + + + align:start position:0% + +a subspace of v + + align:start position:0% + + + + align:start position:0% + +and if i define + + align:start position:0% +and if i define + + + align:start position:0% +and if i define +the following function on + + align:start position:0% + + + + align:start position:0% + +v mod e + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +what is it + + align:start position:0% +what is it + + + align:start position:0% +what is it +this is simply + + align:start position:0% +this is simply + + + align:start position:0% +this is simply +the norm of + + align:start position:0% +the norm of + + + align:start position:0% +the norm of +the representative v + + align:start position:0% +the representative v + + + align:start position:0% +the representative v +of this equivalence + + align:start position:0% +of this equivalence + + + align:start position:0% +of this equivalence +class + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +if i define a function like this so + + align:start position:0% + + + + align:start position:0% + +then + + align:start position:0% +then + + + align:start position:0% +then +this function + + align:start position:0% +this function + + + align:start position:0% +this function +finds + + align:start position:0% +finds + + + align:start position:0% +finds +a norm + + align:start position:0% +a norm + + + align:start position:0% +a norm +on the space v mod e + + align:start position:0% +on the space v mod e + + + align:start position:0% +on the space v mod e +okay so + + align:start position:0% +okay so + + + align:start position:0% +okay so +in short if i have a semi norm and i mod + + align:start position:0% +in short if i have a semi norm and i mod + + + align:start position:0% +in short if i have a semi norm and i mod +out by all the elements + + align:start position:0% +out by all the elements + + + align:start position:0% +out by all the elements +uh with semi norm + + align:start position:0% +uh with semi norm + + + align:start position:0% +uh with semi norm +equal to zero then i get an actual norm + + align:start position:0% +equal to zero then i get an actual norm + + + align:start position:0% +equal to zero then i get an actual norm +space + + align:start position:0% +space + + + align:start position:0% +space +where this norm is + + align:start position:0% +where this norm is + + + align:start position:0% +where this norm is +you know essentially the semi-norm okay + + align:start position:0% + + + + align:start position:0% + +okay so let's prove this + + align:start position:0% +okay so let's prove this + + + align:start position:0% +okay so let's prove this +so why is + + align:start position:0% +so why is + + + align:start position:0% +so why is +why is this a subspace well + + align:start position:0% + + + + align:start position:0% + +if i take two elements + + align:start position:0% + + + + align:start position:0% + +in + + align:start position:0% +in + + + align:start position:0% +in +this space of + + align:start position:0% +this space of + + + align:start position:0% +this space of +elements that have zero semi norm + + align:start position:0% +elements that have zero semi norm + + + align:start position:0% +elements that have zero semi norm +and two scalars + + align:start position:0% + + + + align:start position:0% + +and if i take + + align:start position:0% + + + + align:start position:0% + +the semi-norm of its linear com the + + align:start position:0% +the semi-norm of its linear com the + + + align:start position:0% +the semi-norm of its linear com the +linear combination formed i want to show + + align:start position:0% +linear combination formed i want to show + + + align:start position:0% +linear combination formed i want to show +this is equal to zero and this follows + + align:start position:0% +this is equal to zero and this follows + + + align:start position:0% +this is equal to zero and this follows +essentially by + + align:start position:0% +essentially by + + + align:start position:0% +essentially by +uh homogeneity and the triangle + + align:start position:0% +uh homogeneity and the triangle + + + align:start position:0% +uh homogeneity and the triangle +inequality this is less than or equal to + + align:start position:0% +inequality this is less than or equal to + + + align:start position:0% +inequality this is less than or equal to +um if i apply the triangle inequality + + align:start position:0% +um if i apply the triangle inequality + + + align:start position:0% +um if i apply the triangle inequality +and then pull the scalars out this is + + align:start position:0% +and then pull the scalars out this is + + + align:start position:0% +and then pull the scalars out this is +less than or equal to + + align:start position:0% +less than or equal to + + + align:start position:0% +less than or equal to +plus + + align:start position:0% + + + + align:start position:0% + +and if these both have norm semi norm + + align:start position:0% +and if these both have norm semi norm + + + align:start position:0% +and if these both have norm semi norm +equal to zero this is equal to zero and + + align:start position:0% +equal to zero this is equal to zero and + + + align:start position:0% +equal to zero this is equal to zero and +now remember a semi norm is always + + align:start position:0% +now remember a semi norm is always + + + align:start position:0% +now remember a semi norm is always +non-negative so if i show something is + + align:start position:0% +non-negative so if i show something is + + + align:start position:0% +non-negative so if i show something is +less than or equal to zero it's also + + align:start position:0% +less than or equal to zero it's also + + + align:start position:0% +less than or equal to zero it's also +then it must be equal to zero + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +so first off + + align:start position:0% +so first off + + + align:start position:0% +so first off +we define this function + + align:start position:0% +we define this function + + + align:start position:0% +we define this function +so now let's show that this uh defines a + + align:start position:0% +so now let's show that this uh defines a + + + align:start position:0% +so now let's show that this uh defines a +norm on + + align:start position:0% +norm on + + + align:start position:0% +norm on +v mod e + + align:start position:0% +v mod e + + + align:start position:0% +v mod e +we need to first show it's well defined + + align:start position:0% +we need to first show it's well defined + + + align:start position:0% +we need to first show it's well defined +because you know i'm defining it in + + align:start position:0% +because you know i'm defining it in + + + align:start position:0% +because you know i'm defining it in +terms of + + align:start position:0% +terms of + + + align:start position:0% +terms of +um + + align:start position:0% +um + + + align:start position:0% +um +you know a representative of this + + align:start position:0% +you know a representative of this + + + align:start position:0% +you know a representative of this +equivalence class all right so + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +this + + align:start position:0% + + + + align:start position:0% + +and what does this mean i.e + + align:start position:0% +and what does this mean i.e + + + align:start position:0% +and what does this mean i.e +if uh + + align:start position:0% +if uh + + + align:start position:0% +if uh +b plus + + align:start position:0% +b plus + + + align:start position:0% +b plus +if i have two equivalence classes + + align:start position:0% +if i have two equivalence classes + + + align:start position:0% +if i have two equivalence classes +with + + align:start position:0% +with + + + align:start position:0% +with +or if i have the same equivalence class + + align:start position:0% +or if i have the same equivalence class + + + align:start position:0% +or if i have the same equivalence class +with two different representatives v and + + align:start position:0% +with two different representatives v and + + + align:start position:0% +with two different representatives v and +v prime + + align:start position:0% +v prime + + + align:start position:0% +v prime +then and i should write + + align:start position:0% +then and i should write + + + align:start position:0% +then and i should write +e + + align:start position:0% +e + + + align:start position:0% +e +not w + + align:start position:0% + + + + align:start position:0% + +then + + align:start position:0% +then + + + align:start position:0% +then +the norm of v + + align:start position:0% +the norm of v + + + align:start position:0% +the norm of v +equals the norm of v prime + + align:start position:0% +equals the norm of v prime + + + align:start position:0% +equals the norm of v prime +okay and therefore this function is well + + align:start position:0% +okay and therefore this function is well + + + align:start position:0% +okay and therefore this function is well +defined + + align:start position:0% +defined + + + align:start position:0% +defined +now + + align:start position:0% + + + + align:start position:0% + +how do we do that again it's going to be + + align:start position:0% +how do we do that again it's going to be + + + align:start position:0% +how do we do that again it's going to be +essentially the triangle inequality + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +suppose + + align:start position:0% + + + + align:start position:0% + +b plus e + + align:start position:0% +b plus e + + + align:start position:0% +b plus e +so + + align:start position:0% +so + + + align:start position:0% +so +equals v prime plus e meaning i have two + + align:start position:0% +equals v prime plus e meaning i have two + + + align:start position:0% +equals v prime plus e meaning i have two +representatives for the same equivalence + + align:start position:0% +representatives for the same equivalence + + + align:start position:0% +representatives for the same equivalence +class + + align:start position:0% + + + + align:start position:0% + +and that means there exists a little e + + align:start position:0% +and that means there exists a little e + + + align:start position:0% +and that means there exists a little e +capital e such that + + align:start position:0% +capital e such that + + + align:start position:0% +capital e such that +v is equal to v prime plus e + + align:start position:0% + + + + align:start position:0% + +then + + align:start position:0% +then + + + align:start position:0% +then +if i take the norm of v + + align:start position:0% +if i take the norm of v + + + align:start position:0% +if i take the norm of v +this is equal to norm of v prime plus e + + align:start position:0% +this is equal to norm of v prime plus e + + + align:start position:0% +this is equal to norm of v prime plus e +and by the triangle inequality this is + + align:start position:0% +and by the triangle inequality this is + + + align:start position:0% +and by the triangle inequality this is +less than or equal to + + align:start position:0% +less than or equal to + + + align:start position:0% +less than or equal to +norm of v prime + + align:start position:0% + + + + align:start position:0% + +plus norm of semi norm of e + + align:start position:0% +plus norm of semi norm of e + + + align:start position:0% +plus norm of semi norm of e +and now since e is coming from this set + + align:start position:0% +and now since e is coming from this set + + + align:start position:0% +and now since e is coming from this set +of all vectors with semi norm equal to 0 + + align:start position:0% +of all vectors with semi norm equal to 0 + + + align:start position:0% +of all vectors with semi norm equal to 0 +this is equal to 0 and therefore i get + + align:start position:0% +this is equal to 0 and therefore i get + + + align:start position:0% +this is equal to 0 and therefore i get +the semi norm of v prime + + align:start position:0% +the semi norm of v prime + + + align:start position:0% +the semi norm of v prime +so i've shown that the + + align:start position:0% +so i've shown that the + + + align:start position:0% +so i've shown that the +semi norm of v is less than or equal to + + align:start position:0% +semi norm of v is less than or equal to + + + align:start position:0% +semi norm of v is less than or equal to +the semi norm of v prime + + align:start position:0% +the semi norm of v prime + + + align:start position:0% +the semi norm of v prime +now there was nothing this argument is + + align:start position:0% +now there was nothing this argument is + + + align:start position:0% +now there was nothing this argument is +symmetric in v and v prime all right if + + align:start position:0% +symmetric in v and v prime all right if + + + align:start position:0% +symmetric in v and v prime all right if +v is equal to v prime plus e for some + + align:start position:0% +v is equal to v prime plus e for some + + + align:start position:0% +v is equal to v prime plus e for some +element in capital e so is v prime so i + + align:start position:0% +element in capital e so is v prime so i + + + align:start position:0% +element in capital e so is v prime so i +can also switch + + align:start position:0% +can also switch + + + align:start position:0% +can also switch +um + + align:start position:0% + + + + align:start position:0% + +the + + align:start position:0% +the + + + align:start position:0% +the +i can also switch v and v prime meaning + + align:start position:0% +i can also switch v and v prime meaning + + + align:start position:0% +i can also switch v and v prime meaning +i've shown that + + align:start position:0% +i've shown that + + + align:start position:0% +i've shown that +p is less than or equal to v prime + + align:start position:0% +p is less than or equal to v prime + + + align:start position:0% +p is less than or equal to v prime +and + + align:start position:0% +and + + + align:start position:0% +and +the norm of v prime is less than or + + align:start position:0% +the norm of v prime is less than or + + + align:start position:0% +the norm of v prime is less than or +equal to v + + align:start position:0% +equal to v + + + align:start position:0% +equal to v +and therefore + + align:start position:0% + + + + align:start position:0% + +there are two norms agree + + align:start position:0% +there are two norms agree + + + align:start position:0% +there are two norms agree +so this function here is + + align:start position:0% +so this function here is + + + align:start position:0% +so this function here is +um + + align:start position:0% +um + + + align:start position:0% +um +well-defined + + align:start position:0% + + + + align:start position:0% + +and so + + align:start position:0% +and so + + + align:start position:0% +and so +i'm going to leave it to you now to + + align:start position:0% +i'm going to leave it to you now to + + + align:start position:0% +i'm going to leave it to you now to +check + + align:start position:0% +check + + + align:start position:0% +check +that + + align:start position:0% +that + + + align:start position:0% +that +this function now which is well-defined + + align:start position:0% +this function now which is well-defined + + + align:start position:0% +this function now which is well-defined +on + + align:start position:0% +on + + + align:start position:0% +on +mod e is in fact does in fact satisfy + + align:start position:0% +mod e is in fact does in fact satisfy + + + align:start position:0% +mod e is in fact does in fact satisfy +all the the properties of a semi norm i + + align:start position:0% +all the the properties of a semi norm i + + + align:start position:0% +all the the properties of a semi norm i +mean it's non-negative + + align:start position:0% +mean it's non-negative + + + align:start position:0% +mean it's non-negative +uh so in + + align:start position:0% +uh so in + + + align:start position:0% +uh so in +from essentially + + align:start position:0% +from essentially + + + align:start position:0% +from essentially +um + + align:start position:0% + + + + align:start position:0% + +you know + + align:start position:0% + + + + align:start position:0% + +the homogeneity and triangle inequality + + align:start position:0% +the homogeneity and triangle inequality + + + align:start position:0% +the homogeneity and triangle inequality +property of + + align:start position:0% +property of + + + align:start position:0% +property of +the semi norm the triangle inequality + + align:start position:0% +the semi norm the triangle inequality + + + align:start position:0% +the semi norm the triangle inequality +and homogeneity of this function then + + align:start position:0% +and homogeneity of this function then + + + align:start position:0% +and homogeneity of this function then +follow + + align:start position:0% +follow + + + align:start position:0% +follow +and + + align:start position:0% +and + + + align:start position:0% +and +you know we've essentially + + align:start position:0% +you know we've essentially + + + align:start position:0% +you know we've essentially +equated all elements with semi norm + + align:start position:0% +equated all elements with semi norm + + + align:start position:0% +equated all elements with semi norm +equal to zero to zero so this is why + + align:start position:0% +equal to zero to zero so this is why + + + align:start position:0% +equal to zero to zero so this is why +it's also positive definite so i'm going + + align:start position:0% +it's also positive definite so i'm going + + + align:start position:0% +it's also positive definite so i'm going +to leave that to you + + align:start position:0% +to leave that to you + + + align:start position:0% +to leave that to you +okay + + align:start position:0% + + + + align:start position:0% + +okay now there's one other way + + align:start position:0% +okay now there's one other way + + + align:start position:0% +okay now there's one other way +uh if we're given + + align:start position:0% +uh if we're given + + + align:start position:0% +uh if we're given +so + + align:start position:0% +so + + + align:start position:0% +so +we + + align:start position:0% +we + + + align:start position:0% +we +in this process we started with a semi + + align:start position:0% +in this process we started with a semi + + + align:start position:0% +in this process we started with a semi +norm on the space + + align:start position:0% +norm on the space + + + align:start position:0% +norm on the space +identified the subspace of all + + align:start position:0% +identified the subspace of all + + + align:start position:0% +identified the subspace of all +you know if you'd like zero norm + + align:start position:0% +you know if you'd like zero norm + + + align:start position:0% +you know if you'd like zero norm +elements + + align:start position:0% +elements + + + align:start position:0% +elements +and obtained a new uh + + align:start position:0% +and obtained a new uh + + + align:start position:0% +and obtained a new uh +norm space + + align:start position:0% +norm space + + + align:start position:0% +norm space +but you could start off with a norm + + align:start position:0% +but you could start off with a norm + + + align:start position:0% +but you could start off with a norm +space + + align:start position:0% +space + + + align:start position:0% +space +a closed subspace of that norm space + + align:start position:0% +a closed subspace of that norm space + + + align:start position:0% +a closed subspace of that norm space +and obtain a new + + align:start position:0% +and obtain a new + + + align:start position:0% +and obtain a new +norm space + + align:start position:0% +norm space + + + align:start position:0% +norm space +uh on v + + align:start position:0% +uh on v + + + align:start position:0% +uh on v +mod w if w is at close space + + align:start position:0% +mod w if w is at close space + + + align:start position:0% +mod w if w is at close space +um + + align:start position:0% +um + + + align:start position:0% +um +you know in sort of similar fashion + + align:start position:0% +you know in sort of similar fashion + + + align:start position:0% +you know in sort of similar fashion +where i define this norm this way + + align:start position:0% +where i define this norm this way + + + align:start position:0% +where i define this norm this way +and um + + align:start position:0% + + + + align:start position:0% + +well the norm on that space won't be the + + align:start position:0% +well the norm on that space won't be the + + + align:start position:0% +well the norm on that space won't be the +same as this one but that'll be in the + + align:start position:0% +same as this one but that'll be in the + + + align:start position:0% +same as this one but that'll be in the +exercises okay + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +that's about + + align:start position:0% +that's about + + + align:start position:0% +that's about +uh + + align:start position:0% +uh + + + align:start position:0% +uh +you know + + align:start position:0% + + + + align:start position:0% + +this is kind of concluding the + + align:start position:0% +this is kind of concluding the + + + align:start position:0% +this is kind of concluding the +elementary section of functional + + align:start position:0% +elementary section of functional + + + align:start position:0% +elementary section of functional +analysis meaning uh the bare bones of + + align:start position:0% +analysis meaning uh the bare bones of + + + align:start position:0% +analysis meaning uh the bare bones of +of bonus spaces and norm spaces + + align:start position:0% +of bonus spaces and norm spaces + + + align:start position:0% +of bonus spaces and norm spaces +and now with the rest of this lecture + + align:start position:0% +and now with the rest of this lecture + + + align:start position:0% +and now with the rest of this lecture +and then uh next lecture we're going to + + align:start position:0% +and then uh next lecture we're going to + + + align:start position:0% +and then uh next lecture we're going to +get into + + align:start position:0% +get into + + + align:start position:0% +get into +you know kind of the fundamental + + align:start position:0% +you know kind of the fundamental + + + align:start position:0% +you know kind of the fundamental +results of functional analysis + + align:start position:0% +results of functional analysis + + + align:start position:0% +results of functional analysis +related to + + align:start position:0% +related to + + + align:start position:0% +related to +bonus spaces + + align:start position:0% +bonus spaces + + + align:start position:0% +bonus spaces +so these theorems that i'll now be + + align:start position:0% +so these theorems that i'll now be + + + align:start position:0% +so these theorems that i'll now be +stating and proving in the in the + + align:start position:0% +stating and proving in the in the + + + align:start position:0% +stating and proving in the in the +coming couple of lectures have names + + align:start position:0% +coming couple of lectures have names + + + align:start position:0% +coming couple of lectures have names +attached to them so + + align:start position:0% +attached to them so + + + align:start position:0% +attached to them so +you should definitely know what they are + + align:start position:0% +you should definitely know what they are + + + align:start position:0% +you should definitely know what they are +what they state what they don't state + + align:start position:0% +what they state what they don't state + + + align:start position:0% +what they state what they don't state +um + + align:start position:0% +um + + + align:start position:0% +um +but to prove them i first need a result + + align:start position:0% +but to prove them i first need a result + + + align:start position:0% +but to prove them i first need a result +from metric spaces + + align:start position:0% +from metric spaces + + + align:start position:0% +from metric spaces +which + + align:start position:0% + + + + align:start position:0% + +i did teach last semester + + align:start position:0% +i did teach last semester + + + align:start position:0% +i did teach last semester +but we didn't cover this theorem i can't + + align:start position:0% +but we didn't cover this theorem i can't + + + align:start position:0% +but we didn't cover this theorem i can't +remember if i covered it in when i + + align:start position:0% +remember if i covered it in when i + + + align:start position:0% +remember if i covered it in when i +taught 18 100 b + + align:start position:0% +taught 18 100 b + + + align:start position:0% +taught 18 100 b +i don't think i did + + align:start position:0% +i don't think i did + + + align:start position:0% +i don't think i did +but + + align:start position:0% + + + + align:start position:0% + +so this is about + + align:start position:0% +so this is about + + + align:start position:0% +so this is about +uh + + align:start position:0% + + + + align:start position:0% + +when can you write + + align:start position:0% + + + + align:start position:0% + +or in what way + + align:start position:0% + + + + align:start position:0% + +okay so let me let me + + align:start position:0% +okay so let me let me + + + align:start position:0% +okay so let me let me +let me just state the theorem and then + + align:start position:0% +let me just state the theorem and then + + + align:start position:0% +let me just state the theorem and then +i'll interpret it for you + + align:start position:0% +i'll interpret it for you + + + align:start position:0% +i'll interpret it for you +so this is bear's theorem + + align:start position:0% + + + + align:start position:0% + +it also goes by the name of bears uh the + + align:start position:0% +it also goes by the name of bears uh the + + + align:start position:0% +it also goes by the name of bears uh the +bear category theorem although it has + + align:start position:0% +bear category theorem although it has + + + align:start position:0% +bear category theorem although it has +nothing to do with you know category + + align:start position:0% +nothing to do with you know category + + + align:start position:0% +nothing to do with you know category +theory + + align:start position:0% +theory + + + align:start position:0% +theory +as is + + align:start position:0% +as is + + + align:start position:0% +as is +you know + + align:start position:0% +you know + + + align:start position:0% +you know +i guess used today i don't know if + + align:start position:0% +i guess used today i don't know if + + + align:start position:0% +i guess used today i don't know if +category theory gets used + + align:start position:0% +category theory gets used + + + align:start position:0% +category theory gets used +or if it just is created for itself + + align:start position:0% +or if it just is created for itself + + + align:start position:0% +or if it just is created for itself +um + + align:start position:0% +um + + + align:start position:0% +um +but + + align:start position:0% +but + + + align:start position:0% +but +you know bears + + align:start position:0% +you know bears + + + align:start position:0% +you know bears +bears category theorem is the only + + align:start position:0% +bears category theorem is the only + + + align:start position:0% +bears category theorem is the only +category + + align:start position:0% +category + + + align:start position:0% +category +theorem that i know + + align:start position:0% + + + + align:start position:0% + +so what does it state + + align:start position:0% + + + + align:start position:0% + +if m + + align:start position:0% +if m + + + align:start position:0% +if m +so this is again this is a theorem about + + align:start position:0% +so this is again this is a theorem about + + + align:start position:0% +so this is again this is a theorem about +metric spaces so + + align:start position:0% +metric spaces so + + + align:start position:0% +metric spaces so +uh not + + align:start position:0% +uh not + + + align:start position:0% +uh not +you know necessarily norm spaces so let + + align:start position:0% +you know necessarily norm spaces so let + + + align:start position:0% +you know necessarily norm spaces so let +if m is a + + align:start position:0% + + + + align:start position:0% + +complete + + align:start position:0% + + + + align:start position:0% + +metric space + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +cn + + align:start position:0% +cn + + + align:start position:0% +cn +is a collection of closed subsets + + align:start position:0% + + + + align:start position:0% + +of m + + align:start position:0% +of m + + + align:start position:0% +of m +such that + + align:start position:0% +such that + + + align:start position:0% +such that +m is their union + + align:start position:0% + + + + align:start position:0% + +so this is a uh + + align:start position:0% + + + + align:start position:0% + +so i have it in here so + + align:start position:0% + + + + align:start position:0% + +i should specify this is n is a natural + + align:start position:0% +i should specify this is n is a natural + + + align:start position:0% +i should specify this is n is a natural +number + + align:start position:0% + + + + align:start position:0% + +then + + align:start position:0% + + + + align:start position:0% + +at least one c in uh + + align:start position:0% + + + + align:start position:0% + +contains + + align:start position:0% +contains + + + align:start position:0% +contains +an open ball + + align:start position:0% + + + + align:start position:0% + +bxr which i'll recall this is + + align:start position:0% +bxr which i'll recall this is + + + align:start position:0% +bxr which i'll recall this is +uh instead of all y and m such that the + + align:start position:0% +uh instead of all y and m such that the + + + align:start position:0% +uh instead of all y and m such that the +distance from x to y + + align:start position:0% +distance from x to y + + + align:start position:0% +distance from x to y +is less than r + + align:start position:0% +is less than r + + + align:start position:0% +is less than r +uh + + align:start position:0% +uh + + + align:start position:0% +uh +so + + align:start position:0% +so + + + align:start position:0% +so +at least one c n contains an open ball + + align:start position:0% +at least one c n contains an open ball + + + align:start position:0% +at least one c n contains an open ball +could be stated uh you know more + + align:start position:0% +could be stated uh you know more + + + align:start position:0% +could be stated uh you know more +succinctly + + align:start position:0% +succinctly + + + align:start position:0% +succinctly +as + + align:start position:0% +as + + + align:start position:0% +as +at least one cn + + align:start position:0% + + + + align:start position:0% + +has + + align:start position:0% + + + + align:start position:0% + +an interior point + + align:start position:0% +an interior point + + + align:start position:0% +an interior point +okay + + align:start position:0% + + + + align:start position:0% + +so sometimes in applications these cns + + align:start position:0% +so sometimes in applications these cns + + + align:start position:0% +so sometimes in applications these cns +are not necessarily closed but you know + + align:start position:0% +are not necessarily closed but you know + + + align:start position:0% +are not necessarily closed but you know +if m is equal to the union of these sets + + align:start position:0% +if m is equal to the union of these sets + + + align:start position:0% +if m is equal to the union of these sets +and it's also equal to the union of + + align:start position:0% +and it's also equal to the union of + + + align:start position:0% +and it's also equal to the union of +their closures and so what this theorem + + align:start position:0% +their closures and so what this theorem + + + align:start position:0% +their closures and so what this theorem +says is that if you can write a metric + + align:start position:0% +says is that if you can write a metric + + + align:start position:0% +says is that if you can write a metric +space as a union of sets + + align:start position:0% +space as a union of sets + + + align:start position:0% +space as a union of sets +then the closure of one of those sets + + align:start position:0% +then the closure of one of those sets + + + align:start position:0% +then the closure of one of those sets +has to contain an open ball + + align:start position:0% +has to contain an open ball + + + align:start position:0% +has to contain an open ball +and this um + + align:start position:0% +and this um + + + align:start position:0% +and this um +now + + align:start position:0% +now + + + align:start position:0% +now +let's think a little bit of what it + + align:start position:0% +let's think a little bit of what it + + + align:start position:0% +let's think a little bit of what it +means for + + align:start position:0% +means for + + + align:start position:0% +means for +um + + align:start position:0% +um + + + align:start position:0% +um +or there's a specific terminology for + + align:start position:0% +or there's a specific terminology for + + + align:start position:0% +or there's a specific terminology for +when a closed + + align:start position:0% +when a closed + + + align:start position:0% +when a closed +when the closure of a set does not + + align:start position:0% +when the closure of a set does not + + + align:start position:0% +when the closure of a set does not +contain an open ball that means it's + + align:start position:0% +contain an open ball that means it's + + + align:start position:0% +contain an open ball that means it's +nowhere dense + + align:start position:0% +nowhere dense + + + align:start position:0% +nowhere dense +or that's + + align:start position:0% +or that's + + + align:start position:0% +or that's +the phrase we usually use for that is + + align:start position:0% +the phrase we usually use for that is + + + align:start position:0% +the phrase we usually use for that is +that it's nowhere dense + + align:start position:0% +that it's nowhere dense + + + align:start position:0% +that it's nowhere dense +so + + align:start position:0% +so + + + align:start position:0% +so +bears theorem says that if you have + + align:start position:0% +bears theorem says that if you have + + + align:start position:0% +bears theorem says that if you have +m equal to the union of + + align:start position:0% +m equal to the union of + + + align:start position:0% +m equal to the union of +a collection of sets then the closure of + + align:start position:0% +a collection of sets then the closure of + + + align:start position:0% +a collection of sets then the closure of +one of those sets has to be dense + + align:start position:0% +one of those sets has to be dense + + + align:start position:0% +one of those sets has to be dense +somewhere okay + + align:start position:0% +somewhere okay + + + align:start position:0% +somewhere okay +or you can't write m a complete metric + + align:start position:0% +or you can't write m a complete metric + + + align:start position:0% +or you can't write m a complete metric +space as the union of nowhere dense + + align:start position:0% +space as the union of nowhere dense + + + align:start position:0% +space as the union of nowhere dense +uh subsets + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +all right um + + align:start position:0% +all right um + + + align:start position:0% +all right um +and so this theorem is quite simple to + + align:start position:0% +and so this theorem is quite simple to + + + align:start position:0% +and so this theorem is quite simple to +state it's quite + + align:start position:0% +state it's quite + + + align:start position:0% +state it's quite +very useful and + + align:start position:0% + + + + align:start position:0% + +i mean quite powerful in applications in + + align:start position:0% +i mean quite powerful in applications in + + + align:start position:0% +i mean quite powerful in applications in +fact you can use this theorem to give an + + align:start position:0% +fact you can use this theorem to give an + + + align:start position:0% +fact you can use this theorem to give an +alternative proof to + + align:start position:0% +alternative proof to + + + align:start position:0% +alternative proof to +something that hopefully you saw in your + + align:start position:0% +something that hopefully you saw in your + + + align:start position:0% +something that hopefully you saw in your +analysis class which is that there + + align:start position:0% +analysis class which is that there + + + align:start position:0% +analysis class which is that there +exists a continuous function which is + + align:start position:0% +exists a continuous function which is + + + align:start position:0% +exists a continuous function which is +nowhere differentiable + + align:start position:0% + + + + align:start position:0% + +maybe i'll put that in the exercises + + align:start position:0% +maybe i'll put that in the exercises + + + align:start position:0% +maybe i'll put that in the exercises +maybe i'll just point you to it + + align:start position:0% +maybe i'll just point you to it + + + align:start position:0% +maybe i'll just point you to it +somewhere + + align:start position:0% +somewhere + + + align:start position:0% +somewhere +we'll see + + align:start position:0% +we'll see + + + align:start position:0% +we'll see +all right so the proof is by + + align:start position:0% +all right so the proof is by + + + align:start position:0% +all right so the proof is by +contradiction + + align:start position:0% + + + + align:start position:0% + +i believe this is the first + + align:start position:0% +i believe this is the first + + + align:start position:0% +i believe this is the first +contradiction proof that we've done in + + align:start position:0% +contradiction proof that we've done in + + + align:start position:0% +contradiction proof that we've done in +the class + + align:start position:0% +the class + + + align:start position:0% +the class +so in 18100 a and b i mean + + align:start position:0% +so in 18100 a and b i mean + + + align:start position:0% +so in 18100 a and b i mean +you start off everything is by + + align:start position:0% +you start off everything is by + + + align:start position:0% +you start off everything is by +contradiction + + align:start position:0% +contradiction + + + align:start position:0% +contradiction +um + + align:start position:0% +um + + + align:start position:0% +um +so + + align:start position:0% +so + + + align:start position:0% +so +um let's suppose not + + align:start position:0% +um let's suppose not + + + align:start position:0% +um let's suppose not +i.e you can find there is a + + align:start position:0% +i.e you can find there is a + + + align:start position:0% +i.e you can find there is a +collection of closed + + align:start position:0% +collection of closed + + + align:start position:0% +collection of closed +subsets of m such that m is equal to + + align:start position:0% +subsets of m such that m is equal to + + + align:start position:0% +subsets of m such that m is equal to +this union and what we're going to do is + + align:start position:0% +this union and what we're going to do is + + + align:start position:0% +this union and what we're going to do is +we're going to find a point that's not + + align:start position:0% +we're going to find a point that's not + + + align:start position:0% +we're going to find a point that's not +in this union and therefore not an m and + + align:start position:0% +in this union and therefore not an m and + + + align:start position:0% +in this union and therefore not an m and +that'll be our contradiction + + align:start position:0% +that'll be our contradiction + + + align:start position:0% +that'll be our contradiction +we'll use uh + + align:start position:0% +we'll use uh + + + align:start position:0% +we'll use uh +the completeness of m to obtain this + + align:start position:0% +the completeness of m to obtain this + + + align:start position:0% +the completeness of m to obtain this +point because this how we're going to + + align:start position:0% +point because this how we're going to + + + align:start position:0% +point because this how we're going to +obtain this point is + + align:start position:0% +obtain this point is + + + align:start position:0% +obtain this point is +as a limit of a certain sequence + + align:start position:0% +as a limit of a certain sequence + + + align:start position:0% +as a limit of a certain sequence +and + + align:start position:0% +and + + + align:start position:0% +and +to uh to be able to say that this limit + + align:start position:0% +to uh to be able to say that this limit + + + align:start position:0% +to uh to be able to say that this limit +exists we're going to show the sequences + + align:start position:0% +exists we're going to show the sequences + + + align:start position:0% +exists we're going to show the sequences +koshi + + align:start position:0% +koshi + + + align:start position:0% +koshi +all right + + align:start position:0% +all right + + + align:start position:0% +all right +so we're going to build up this sequence + + align:start position:0% +so we're going to build up this sequence + + + align:start position:0% +so we're going to build up this sequence +uh inductively + + align:start position:0% +uh inductively + + + align:start position:0% +uh inductively +and + + align:start position:0% +and + + + align:start position:0% +and +i will write this inductive proof kind + + align:start position:0% +i will write this inductive proof kind + + + align:start position:0% +i will write this inductive proof kind +of carefully this first time + + align:start position:0% +of carefully this first time + + + align:start position:0% +of carefully this first time +and then in the future i'm just going to + + align:start position:0% +and then in the future i'm just going to + + + align:start position:0% +and then in the future i'm just going to +say okay + + align:start position:0% +say okay + + + align:start position:0% +say okay +choose p1 this way choose p2 this way + + align:start position:0% +choose p1 this way choose p2 this way + + + align:start position:0% +choose p1 this way choose p2 this way +continuing in this manner we obtain a + + align:start position:0% +continuing in this manner we obtain a + + + align:start position:0% +continuing in this manner we obtain a +sequence of points this blah blah blah + + align:start position:0% +sequence of points this blah blah blah + + + align:start position:0% +sequence of points this blah blah blah +but this point at this stage i'll write + + align:start position:0% +but this point at this stage i'll write + + + align:start position:0% +but this point at this stage i'll write +this uh inductive proof kind of + + align:start position:0% +this uh inductive proof kind of + + + align:start position:0% +this uh inductive proof kind of +carefully + + align:start position:0% +carefully + + + align:start position:0% +carefully +okay so suppose + + align:start position:0% +okay so suppose + + + align:start position:0% +okay so suppose +not um + + align:start position:0% + + + + align:start position:0% + +since m + + align:start position:0% + + + + align:start position:0% + +certainly contains an open ball + + align:start position:0% +certainly contains an open ball + + + align:start position:0% +certainly contains an open ball +and c1 cannot + + align:start position:0% +and c1 cannot + + + align:start position:0% +and c1 cannot +contain an open ball + + align:start position:0% + + + + align:start position:0% + +this implies m does not equal to the + + align:start position:0% +this implies m does not equal to the + + + align:start position:0% +this implies m does not equal to the +first closed set otherwise the first + + align:start position:0% +first closed set otherwise the first + + + align:start position:0% +first closed set otherwise the first +closed set would contain an open ball + + align:start position:0% + + + + align:start position:0% + +thus there exists an element p1 + + align:start position:0% +thus there exists an element p1 + + + align:start position:0% +thus there exists an element p1 +and m take away c1 + + align:start position:0% +and m take away c1 + + + align:start position:0% +and m take away c1 +now c1 is closed + + align:start position:0% + + + + align:start position:0% + +this implies that its complement is open + + align:start position:0% + + + + align:start position:0% + +and therefore i can find + + align:start position:0% + + + + align:start position:0% + +a small epsilon 1 + + align:start position:0% +a small epsilon 1 + + + align:start position:0% +a small epsilon 1 +such that + + align:start position:0% +such that + + + align:start position:0% +such that +the ball centered at + + align:start position:0% +the ball centered at + + + align:start position:0% +the ball centered at +p1 + + align:start position:0% +p1 + + + align:start position:0% +p1 +of radius epsilon 1 + + align:start position:0% +of radius epsilon 1 + + + align:start position:0% +of radius epsilon 1 +intersects c1 uh + + align:start position:0% +intersects c1 uh + + + align:start position:0% +intersects c1 uh +equals + + align:start position:0% +equals + + + align:start position:0% +equals +the empty set + + align:start position:0% +the empty set + + + align:start position:0% +the empty set +okay + + align:start position:0% + + + + align:start position:0% + +now i'm going to pick c2 + + align:start position:0% + + + + align:start position:0% + +now the ball + + align:start position:0% + + + + align:start position:0% + +centered at p1 of radius + + align:start position:0% +centered at p1 of radius + + + align:start position:0% +centered at p1 of radius +epsilon 1 over + + align:start position:0% +epsilon 1 over + + + align:start position:0% +epsilon 1 over +three + + align:start position:0% +three + + + align:start position:0% +three +this is not contained in c2 because + + align:start position:0% +this is not contained in c2 because + + + align:start position:0% +this is not contained in c2 because +again this is by contradiction so we're + + align:start position:0% +again this is by contradiction so we're + + + align:start position:0% +again this is by contradiction so we're +assuming that m is written as a union of + + align:start position:0% +assuming that m is written as a union of + + + align:start position:0% +assuming that m is written as a union of +close sets and none of these close sets + + align:start position:0% +close sets and none of these close sets + + + align:start position:0% +close sets and none of these close sets +contain an open ball so this open ball + + align:start position:0% +contain an open ball so this open ball + + + align:start position:0% +contain an open ball so this open ball +cannot be contained in c2 + + align:start position:0% +cannot be contained in c2 + + + align:start position:0% +cannot be contained in c2 +okay + + align:start position:0% + + + + align:start position:0% + +and therefore + + align:start position:0% +and therefore + + + align:start position:0% +and therefore +there exists + + align:start position:0% + + + + align:start position:0% + +some point p2 in this open ball + + align:start position:0% +some point p2 in this open ball + + + align:start position:0% +some point p2 in this open ball +centered at p1 of radius epsilon 1 over + + align:start position:0% +centered at p1 of radius epsilon 1 over + + + align:start position:0% +centered at p1 of radius epsilon 1 over + + align:start position:0% + + + align:start position:0% +such that + + align:start position:0% +such that + + + align:start position:0% +such that +p2 + + align:start position:0% +p2 + + + align:start position:0% +p2 +is not in c2 + + align:start position:0% + + + + align:start position:0% + +now again + + align:start position:0% +now again + + + align:start position:0% +now again +c2 closed + + align:start position:0% + + + + align:start position:0% + +implies that + + align:start position:0% +implies that + + + align:start position:0% +implies that +there exists + + align:start position:0% +there exists + + + align:start position:0% +there exists +an epsilon + + align:start position:0% +an epsilon + + + align:start position:0% +an epsilon +2 less than + + align:start position:0% +2 less than + + + align:start position:0% +2 less than +epsilon over 3 so we can make it very + + align:start position:0% +epsilon over 3 so we can make it very + + + align:start position:0% +epsilon over 3 so we can make it very +small if we wish + + align:start position:0% +small if we wish + + + align:start position:0% +small if we wish +such that + + align:start position:0% + + + + align:start position:0% + +the ball + + align:start position:0% +the ball + + + align:start position:0% +the ball +centered at p2 of radius epsilon 2 + + align:start position:0% +centered at p2 of radius epsilon 2 + + + align:start position:0% +centered at p2 of radius epsilon 2 +intersects c2 equals + + align:start position:0% +intersects c2 equals + + + align:start position:0% +intersects c2 equals +the empty set + + align:start position:0% +the empty set + + + align:start position:0% +the empty set +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so now i've picked uh p2 + + align:start position:0% +so now i've picked uh p2 + + + align:start position:0% +so now i've picked uh p2 +p1 and p2 now + + align:start position:0% +p1 and p2 now + + + align:start position:0% +p1 and p2 now +at this point i would usually say + + align:start position:0% +at this point i would usually say + + + align:start position:0% +at this point i would usually say +continuing in this manner we obtain a + + align:start position:0% +continuing in this manner we obtain a + + + align:start position:0% +continuing in this manner we obtain a +sequence of points but let me write out + + align:start position:0% +sequence of points but let me write out + + + align:start position:0% +sequence of points but let me write out +the argument carefully + + align:start position:0% + + + + align:start position:0% + +suppose there exists + + align:start position:0% + + + + align:start position:0% + +k points + + align:start position:0% +k points + + + align:start position:0% +k points +p1 + + align:start position:0% +p1 + + + align:start position:0% +p1 +pk + + align:start position:0% + + + + align:start position:0% + +and positive + + align:start position:0% + + + + align:start position:0% + +epsilon 1 + + align:start position:0% +epsilon 1 + + + align:start position:0% +epsilon 1 +epsilon k + + align:start position:0% + + + + align:start position:0% + +such that + + align:start position:0% +such that + + + align:start position:0% +such that +such that + + align:start position:0% +such that + + + align:start position:0% +such that +two things occur + + align:start position:0% +two things occur + + + align:start position:0% +two things occur +so + + align:start position:0% +so + + + align:start position:0% +so +epsilon k is less than + + align:start position:0% +epsilon k is less than + + + align:start position:0% +epsilon k is less than +epsilon k minus one over three + + align:start position:0% +epsilon k minus one over three + + + align:start position:0% +epsilon k minus one over three +and + + align:start position:0% + + + + align:start position:0% + +which is + + align:start position:0% +which is + + + align:start position:0% +which is +less than epsilon k minus uh two over + + align:start position:0% +less than epsilon k minus uh two over + + + align:start position:0% +less than epsilon k minus uh two over +three and so on all the way down to + + align:start position:0% +three and so on all the way down to + + + align:start position:0% +three and so on all the way down to +epsilon 1 over + + align:start position:0% +epsilon 1 over + + + align:start position:0% +epsilon 1 over + + align:start position:0% + + + align:start position:0% +k minus 1. + + align:start position:0% + + + + align:start position:0% + +so if you like + + align:start position:0% +so if you like + + + align:start position:0% +so if you like +k here is bigger than or equal to 2. + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +uh pj + + align:start position:0% + + + + align:start position:0% + +satisfy + + align:start position:0% +satisfy + + + align:start position:0% +satisfy +pj is in the ball centered at p j minus + + align:start position:0% +pj is in the ball centered at p j minus + + + align:start position:0% +pj is in the ball centered at p j minus +one + + align:start position:0% +one + + + align:start position:0% +one +of radius epsilon j minus one over three + + align:start position:0% +of radius epsilon j minus one over three + + + align:start position:0% +of radius epsilon j minus one over three +and + + align:start position:0% +and + + + align:start position:0% +and +the ball + + align:start position:0% +the ball + + + align:start position:0% +the ball +of centered at p j + + align:start position:0% +of centered at p j + + + align:start position:0% +of centered at p j +epsilon j intersect c + + align:start position:0% +epsilon j intersect c + + + align:start position:0% +epsilon j intersect c +j equals + + align:start position:0% +j equals + + + align:start position:0% +j equals +the empty set + + align:start position:0% +the empty set + + + align:start position:0% +the empty set +okay + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% + + + + align:start position:0% + +let me start those uh + + align:start position:0% +let me start those uh + + + align:start position:0% +let me start those uh +two properties right there + + align:start position:0% +two properties right there + + + align:start position:0% +two properties right there +we're gonna obtain + + align:start position:0% +we're gonna obtain + + + align:start position:0% +we're gonna obtain +another point + + align:start position:0% +another point + + + align:start position:0% +another point +satisfying those two properties + + align:start position:0% +satisfying those two properties + + + align:start position:0% +satisfying those two properties +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and uh + + align:start position:0% + + + + align:start position:0% + +i don't know why i'm being a stickler it + + align:start position:0% +i don't know why i'm being a stickler it + + + align:start position:0% +i don't know why i'm being a stickler it +doesn't really matter but let me put a + + align:start position:0% +doesn't really matter but let me put a + + + align:start position:0% +doesn't really matter but let me put a +two + + align:start position:0% + + + + align:start position:0% + +because that's not necessarily satisfied + + align:start position:0% +because that's not necessarily satisfied + + + align:start position:0% +because that's not necessarily satisfied +for p1 but okay + + align:start position:0% +for p1 but okay + + + align:start position:0% +for p1 but okay +um + + align:start position:0% +um + + + align:start position:0% +um +now i want to show there exist i can + + align:start position:0% +now i want to show there exist i can + + + align:start position:0% +now i want to show there exist i can +obtain + + align:start position:0% +obtain + + + align:start position:0% +obtain +a k plus first point satisfying + + align:start position:0% +a k plus first point satisfying + + + align:start position:0% +a k plus first point satisfying +those two properties okay + + align:start position:0% +those two properties okay + + + align:start position:0% +those two properties okay +again this is just formally saying that + + align:start position:0% +again this is just formally saying that + + + align:start position:0% +again this is just formally saying that +once i've chosen p2 then i can choose a + + align:start position:0% +once i've chosen p2 then i can choose a + + + align:start position:0% +once i've chosen p2 then i can choose a +p3 + + align:start position:0% +p3 + + + align:start position:0% +p3 +doing this um + + align:start position:0% + + + + align:start position:0% + +argument again and it'll satisfy + + align:start position:0% +argument again and it'll satisfy + + + align:start position:0% +argument again and it'll satisfy +everything + + align:start position:0% +everything + + + align:start position:0% +everything +p2 satisfied with epsilon one except now + + align:start position:0% +p2 satisfied with epsilon one except now + + + align:start position:0% +p2 satisfied with epsilon one except now +with epsilon two but now i'm just making + + align:start position:0% +with epsilon two but now i'm just making + + + align:start position:0% +with epsilon two but now i'm just making +it more formal so + + align:start position:0% + + + + align:start position:0% + +now again m is the union of all these + + align:start position:0% +now again m is the union of all these + + + align:start position:0% +now again m is the union of all these +closed sets none of which contain an + + align:start position:0% +closed sets none of which contain an + + + align:start position:0% +closed sets none of which contain an +open ball + + align:start position:0% +open ball + + + align:start position:0% +open ball +so since + + align:start position:0% + + + + align:start position:0% + +the ball + + align:start position:0% +the ball + + + align:start position:0% +the ball +of radius p k + + align:start position:0% +of radius p k + + + align:start position:0% +of radius p k +epsilon k over 3 + + align:start position:0% +epsilon k over 3 + + + align:start position:0% +epsilon k over 3 +is not contained + + align:start position:0% +is not contained + + + align:start position:0% +is not contained +in + + align:start position:0% +in + + + align:start position:0% +in +c + + align:start position:0% +c + + + align:start position:0% +c +k plus 1. + + align:start position:0% +k plus 1. + + + align:start position:0% +k plus 1. +there exists + + align:start position:0% + + + + align:start position:0% + +element pk plus one + + align:start position:0% +element pk plus one + + + align:start position:0% +element pk plus one +not in + + align:start position:0% +not in + + + align:start position:0% +not in +ck plus one or i should say + + align:start position:0% + + + + align:start position:0% + + + align:start position:0% + + + + align:start position:0% + +such that + + align:start position:0% + + + + align:start position:0% + +p k plus 1 is not + + align:start position:0% + + + + align:start position:0% + +ck plus one + + align:start position:0% +ck plus one + + + align:start position:0% +ck plus one +okay so let me + + align:start position:0% + + + + align:start position:0% + +there's pk + + align:start position:0% +there's pk + + + align:start position:0% +there's pk +epsilon k + + align:start position:0% +epsilon k + + + align:start position:0% +epsilon k +over three + + align:start position:0% + + + + align:start position:0% + +c k plus one + + align:start position:0% +c k plus one + + + align:start position:0% +c k plus one +so maybe they're not disjoint maybe + + align:start position:0% +so maybe they're not disjoint maybe + + + align:start position:0% +so maybe they're not disjoint maybe +there's some overlap but then i can find + + align:start position:0% +there's some overlap but then i can find + + + align:start position:0% +there's some overlap but then i can find +a point p k plus one um + + align:start position:0% + + + + align:start position:0% + +in there that's not in ck plus one + + align:start position:0% + + + + align:start position:0% + +so then + + align:start position:0% + + + + align:start position:0% + +there exists an epsilon k plus one which + + align:start position:0% +there exists an epsilon k plus one which + + + align:start position:0% +there exists an epsilon k plus one which +i can choose very small say smaller than + + align:start position:0% +i can choose very small say smaller than + + + align:start position:0% +i can choose very small say smaller than +epsilon k over 3 + + align:start position:0% +epsilon k over 3 + + + align:start position:0% +epsilon k over 3 +such that + + align:start position:0% +such that + + + align:start position:0% +such that +again because ck plus 1 is closed + + align:start position:0% +again because ck plus 1 is closed + + + align:start position:0% +again because ck plus 1 is closed +pk plus 1 is not in ck plus 1. so i can + + align:start position:0% +pk plus 1 is not in ck plus 1. so i can + + + align:start position:0% +pk plus 1 is not in ck plus 1. so i can +find a small + + align:start position:0% +find a small + + + align:start position:0% +find a small +ball around pk plus 1 disjoint from ck + + align:start position:0% +ball around pk plus 1 disjoint from ck + + + align:start position:0% +ball around pk plus 1 disjoint from ck +plus one + + align:start position:0% + + + + align:start position:0% + +ball + + align:start position:0% + + + + align:start position:0% + +intersect ck + + align:start position:0% + + + + align:start position:0% + +equals + + align:start position:0% +equals + + + align:start position:0% +equals +the empty set + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +okay so then + + align:start position:0% +okay so then + + + align:start position:0% +okay so then +uh given k points i can then choose a k + + align:start position:0% +uh given k points i can then choose a k + + + align:start position:0% +uh given k points i can then choose a k +plus first point + + align:start position:0% +plus first point + + + align:start position:0% +plus first point +uh satisfying these two bullet points + + align:start position:0% +uh satisfying these two bullet points + + + align:start position:0% +uh satisfying these two bullet points +here + + align:start position:0% +here + + + align:start position:0% +here +all right + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% + + + + align:start position:0% + +by induction we have + + align:start position:0% + + + + align:start position:0% + +found a sequence of points + + align:start position:0% + + + + align:start position:0% + +pk + + align:start position:0% + + + + align:start position:0% + +and m + + align:start position:0% +and m + + + align:start position:0% +and m +such that and + + align:start position:0% + + + + align:start position:0% + +epsilon k so if you like k starts at 2 + + align:start position:0% + + + + align:start position:0% + +epsilon k and 0 + + align:start position:0% + + + + align:start position:0% + +epsilon 1. + + align:start position:0% + + + + align:start position:0% + +such that for all k + + align:start position:0% +such that for all k + + + align:start position:0% +such that for all k +those two bullet points hold such that + + align:start position:0% + + + + align:start position:0% + +which i denoted which i put a little + + align:start position:0% +which i denoted which i put a little + + + align:start position:0% +which i denoted which i put a little +star by star hold so i'm talking about + + align:start position:0% +star by star hold so i'm talking about + + + align:start position:0% +star by star hold so i'm talking about +these two points + + align:start position:0% + + + + align:start position:0% + +so when i say star i mean + + align:start position:0% +so when i say star i mean + + + align:start position:0% +so when i say star i mean +these two statements here + + align:start position:0% +these two statements here + + + align:start position:0% +these two statements here +okay + + align:start position:0% +okay + + + align:start position:0% +okay +[Applause] + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +now um + + align:start position:0% + + + + align:start position:0% + +now let's show that this sequence is + + align:start position:0% +now let's show that this sequence is + + + align:start position:0% +now let's show that this sequence is +koshy so now i claim + + align:start position:0% + + + + align:start position:0% + +how do we do that + + align:start position:0% + + + + align:start position:0% + +this + + align:start position:0% +this + + + align:start position:0% +this +follows so i'm not going to write out + + align:start position:0% +follows so i'm not going to write out + + + align:start position:0% +follows so i'm not going to write out +the full epsilon m argument but i'm just + + align:start position:0% +the full epsilon m argument but i'm just + + + align:start position:0% +the full epsilon m argument but i'm just +going to write down the crucial estimate + + align:start position:0% +going to write down the crucial estimate + + + align:start position:0% +going to write down the crucial estimate +that proves this this follows from + + align:start position:0% +that proves this this follows from + + + align:start position:0% +that proves this this follows from +the fact that for all + + align:start position:0% +the fact that for all + + + align:start position:0% +the fact that for all +okay + + align:start position:0% + + + + align:start position:0% + +for all l + + align:start position:0% +for all l + + + align:start position:0% +for all l +if i look at the distance between p k + + align:start position:0% +if i look at the distance between p k + + + align:start position:0% +if i look at the distance between p k +and p k a plus l because you know in the + + align:start position:0% +and p k a plus l because you know in the + + + align:start position:0% +and p k a plus l because you know in the +end when i look at um if i want to show + + align:start position:0% +end when i look at um if i want to show + + + align:start position:0% +end when i look at um if i want to show +something's koshy i need to take the + + align:start position:0% +something's koshy i need to take the + + + align:start position:0% +something's koshy i need to take the +difference of two or the distance + + align:start position:0% +difference of two or the distance + + + align:start position:0% +difference of two or the distance +between two points um + + align:start position:0% +between two points um + + + align:start position:0% +between two points um +one you know i can choose as uh the + + align:start position:0% +one you know i can choose as uh the + + + align:start position:0% +one you know i can choose as uh the +point occurring earlier in the sequence + + align:start position:0% +point occurring earlier in the sequence + + + align:start position:0% +point occurring earlier in the sequence +and then one occurring later + + align:start position:0% +and then one occurring later + + + align:start position:0% +and then one occurring later +anyways + + align:start position:0% +anyways + + + align:start position:0% +anyways +then by the triangle inequality repeated + + align:start position:0% +then by the triangle inequality repeated + + + align:start position:0% +then by the triangle inequality repeated +i can write that this is less than or + + align:start position:0% +i can write that this is less than or + + + align:start position:0% +i can write that this is less than or +equal to the distance from p k + + align:start position:0% +equal to the distance from p k + + + align:start position:0% +equal to the distance from p k +p k plus one + + align:start position:0% +p k plus one + + + align:start position:0% +p k plus one +plus the distance from p + + align:start position:0% +plus the distance from p + + + align:start position:0% +plus the distance from p +k plus one p k plus l + + align:start position:0% +k plus one p k plus l + + + align:start position:0% +k plus one p k plus l +and now i could do the triangle + + align:start position:0% +and now i could do the triangle + + + align:start position:0% +and now i could do the triangle +inequality again + + align:start position:0% +inequality again + + + align:start position:0% +inequality again +and + + align:start position:0% +and + + + align:start position:0% +and +so i get that this is less than or equal + + align:start position:0% +so i get that this is less than or equal + + + align:start position:0% +so i get that this is less than or equal +to + + align:start position:0% +to + + + align:start position:0% +to +the distance from p k to p k plus 1 plus + + align:start position:0% +the distance from p k to p k plus 1 plus + + + align:start position:0% +the distance from p k to p k plus 1 plus +the distance from p k + + align:start position:0% +the distance from p k + + + align:start position:0% +the distance from p k +plus 1 to p k plus 2 + + align:start position:0% + + + + align:start position:0% + +and so on until i get to the distance + + align:start position:0% +and so on until i get to the distance + + + align:start position:0% +and so on until i get to the distance +between p + + align:start position:0% +between p + + + align:start position:0% +between p +k plus l minus 1 + + align:start position:0% +k plus l minus 1 + + + align:start position:0% +k plus l minus 1 +and p k plus l + + align:start position:0% + + + + align:start position:0% + +now + + align:start position:0% +now + + + align:start position:0% +now +uh by star what's in yellow + + align:start position:0% +uh by star what's in yellow + + + align:start position:0% +uh by star what's in yellow +okay + + align:start position:0% +okay + + + align:start position:0% +okay +p k plus one is in the epsilon k over + + align:start position:0% +p k plus one is in the epsilon k over + + + align:start position:0% +p k plus one is in the epsilon k over +three ball + + align:start position:0% +three ball + + + align:start position:0% +three ball +uh centered at p k + + align:start position:0% +uh centered at p k + + + align:start position:0% +uh centered at p k +so this is less than epsilon k + + align:start position:0% +so this is less than epsilon k + + + align:start position:0% +so this is less than epsilon k +over three and the same thing here less + + align:start position:0% +over three and the same thing here less + + + align:start position:0% +over three and the same thing here less +than epsilon k plus one + + align:start position:0% +than epsilon k plus one + + + align:start position:0% +than epsilon k plus one +over three + + align:start position:0% +over three + + + align:start position:0% +over three +plus + + align:start position:0% +plus + + + align:start position:0% +plus +epsilon + + align:start position:0% +epsilon + + + align:start position:0% +epsilon +k plus l minus 1 + + align:start position:0% +k plus l minus 1 + + + align:start position:0% +k plus l minus 1 +over 3. + + align:start position:0% +over 3. + + + align:start position:0% +over 3. +and now all of those are less than uh + + align:start position:0% +and now all of those are less than uh + + + align:start position:0% +and now all of those are less than uh +if you go to the first one is less than + + align:start position:0% +if you go to the first one is less than + + + align:start position:0% +if you go to the first one is less than +epsilon 1 over 3k minus of 1 so then + + align:start position:0% +epsilon 1 over 3k minus of 1 so then + + + align:start position:0% +epsilon 1 over 3k minus of 1 so then +this is less than + + align:start position:0% + + + + align:start position:0% + +epsilon 1 over + + align:start position:0% +epsilon 1 over + + + align:start position:0% +epsilon 1 over +3 k plus + + align:start position:0% + + + + align:start position:0% + +epsilon 1 over 3 + + align:start position:0% +epsilon 1 over 3 + + + align:start position:0% +epsilon 1 over 3 +k plus l + + align:start position:0% +k plus l + + + align:start position:0% +k plus l +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +okay + + align:start position:0% + + + + align:start position:0% + +and now i can actually sum this up right + + align:start position:0% +and now i can actually sum this up right + + + align:start position:0% +and now i can actually sum this up right +this is equal to and this is + + align:start position:0% +this is equal to and this is + + + align:start position:0% +this is equal to and this is +strictly less than uh + + align:start position:0% +strictly less than uh + + + align:start position:0% +strictly less than uh +epsilon one and if i summed now from + + align:start position:0% +epsilon one and if i summed now from + + + align:start position:0% +epsilon one and if i summed now from +l equals k to infinity one over + + align:start position:0% +l equals k to infinity one over + + + align:start position:0% +l equals k to infinity one over +three k this is equal to + + align:start position:0% +three k this is equal to + + + align:start position:0% +three k this is equal to +one over + + align:start position:0% + + + + align:start position:0% + +epsilon 1 3 k + + align:start position:0% +epsilon 1 3 k + + + align:start position:0% +epsilon 1 3 k +1 over 1 minus 1 3 + + align:start position:0% +1 over 1 minus 1 3 + + + align:start position:0% +1 over 1 minus 1 3 +which equals + + align:start position:0% + + + + align:start position:0% + +epsilon 1 over 2 + + align:start position:0% +epsilon 1 over 2 + + + align:start position:0% +epsilon 1 over 2 +3 to the minus k + + align:start position:0% +3 to the minus k + + + align:start position:0% +3 to the minus k +plus one + + align:start position:0% +plus one + + + align:start position:0% +plus one +okay so the distance between a point p k + + align:start position:0% +okay so the distance between a point p k + + + align:start position:0% +okay so the distance between a point p k +and p k plus l + + align:start position:0% +and p k plus l + + + align:start position:0% +and p k plus l +is less than + + align:start position:0% +is less than + + + align:start position:0% +is less than +some constant times three to the minus k + + align:start position:0% +some constant times three to the minus k + + + align:start position:0% +some constant times three to the minus k +uh plus one so if k is very large this + + align:start position:0% +uh plus one so if k is very large this + + + align:start position:0% +uh plus one so if k is very large this +is very small independent of l okay so i + + align:start position:0% +is very small independent of l okay so i + + + align:start position:0% +is very small independent of l okay so i +shouldn't have used l here + + align:start position:0% +shouldn't have used l here + + + align:start position:0% +shouldn't have used l here +and that's uh + + align:start position:0% +and that's uh + + + align:start position:0% +and that's uh +m + + align:start position:0% +m + + + align:start position:0% +m +m + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so this shows that the sequence is koshy + + align:start position:0% + + + + align:start position:0% + +so since m is complete + + align:start position:0% + + + + align:start position:0% + +there exists + + align:start position:0% +there exists + + + align:start position:0% +there exists +p and m + + align:start position:0% +p and m + + + align:start position:0% +p and m +such that + + align:start position:0% +such that + + + align:start position:0% +such that +these elements p k + + align:start position:0% +these elements p k + + + align:start position:0% +these elements p k +converge to p + + align:start position:0% +converge to p + + + align:start position:0% +converge to p +and now we're going to show this point p + + align:start position:0% +and now we're going to show this point p + + + align:start position:0% +and now we're going to show this point p +does not lie + + align:start position:0% + + + + align:start position:0% + +in any of the cj's + + align:start position:0% + + + + align:start position:0% + +and we'll do it by showing it's + + align:start position:0% +and we'll do it by showing it's + + + align:start position:0% +and we'll do it by showing it's +essentially in all of these + + align:start position:0% +essentially in all of these + + + align:start position:0% +essentially in all of these +balls pj epsilon j + + align:start position:0% +balls pj epsilon j + + + align:start position:0% +balls pj epsilon j +okay + + align:start position:0% + + + + align:start position:0% + +all right and it's kind of a similar + + align:start position:0% +all right and it's kind of a similar + + + align:start position:0% +all right and it's kind of a similar +computation to what we just did + + align:start position:0% +computation to what we just did + + + align:start position:0% +computation to what we just did +so um + + align:start position:0% + + + + align:start position:0% + +now for all + + align:start position:0% + + + + align:start position:0% + +for all k + + align:start position:0% +for all k + + + align:start position:0% +for all k +natural number if we look at the + + align:start position:0% +natural number if we look at the + + + align:start position:0% +natural number if we look at the +distance between + + align:start position:0% +distance between + + + align:start position:0% +distance between +pk + + align:start position:0% +pk + + + align:start position:0% +pk +plus 1 + + align:start position:0% +plus 1 + + + align:start position:0% +plus 1 +pk plus 1 plus l + + align:start position:0% + + + + align:start position:0% + +again if i + + align:start position:0% +again if i + + + align:start position:0% +again if i +so if i just go back to + + align:start position:0% +so if i just go back to + + + align:start position:0% +so if i just go back to +this computation right here + + align:start position:0% +this computation right here + + + align:start position:0% +this computation right here +right this we proved was less than + + align:start position:0% +right this we proved was less than + + + align:start position:0% +right this we proved was less than +epsilon + + align:start position:0% +epsilon + + + align:start position:0% +epsilon +k plus one + + align:start position:0% +k plus one + + + align:start position:0% +k plus one +times one over three + + align:start position:0% +times one over three + + + align:start position:0% +times one over three +k plus one + + align:start position:0% +k plus one + + + align:start position:0% +k plus one +plus + + align:start position:0% +plus + + + align:start position:0% +plus +uh actually one over three + + align:start position:0% + + + + align:start position:0% + +plus one over three squared plus + + align:start position:0% +plus one over three squared plus + + + align:start position:0% +plus one over three squared plus +uh + + align:start position:0% +uh + + + align:start position:0% +uh +one over + + align:start position:0% +one over + + + align:start position:0% +one over +three k plus one um + + align:start position:0% +three k plus one um + + + align:start position:0% +three k plus one um +no k plus l + + align:start position:0% + + + + align:start position:0% + +or i'm sorry i think that's just l + + align:start position:0% + + + + align:start position:0% + +and now + + align:start position:0% +and now + + + align:start position:0% +and now +this thing is less than if i replace it + + align:start position:0% +this thing is less than if i replace it + + + align:start position:0% +this thing is less than if i replace it +by the infinite sum so this is less than + + align:start position:0% +by the infinite sum so this is less than + + + align:start position:0% +by the infinite sum so this is less than +epsilon k plus 1 + + align:start position:0% +epsilon k plus 1 + + + align:start position:0% +epsilon k plus 1 +times the infinite sum again + + align:start position:0% +times the infinite sum again + + + align:start position:0% +times the infinite sum again +m equals 0 to infinity + + align:start position:0% +m equals 0 to infinity + + + align:start position:0% +m equals 0 to infinity +3 to the minus m + + align:start position:0% +3 to the minus m + + + align:start position:0% +3 to the minus m +which equals + + align:start position:0% +which equals + + + align:start position:0% +which equals +what + + align:start position:0% + + + + align:start position:0% + +so this is again equal to + + align:start position:0% +so this is again equal to + + + align:start position:0% +so this is again equal to +epsilon k plus one times + + align:start position:0% +epsilon k plus one times + + + align:start position:0% +epsilon k plus one times +three halves + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +now um + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +okay so + + align:start position:0% +okay so + + + align:start position:0% +okay so +we've proven that uh the distance + + align:start position:0% +we've proven that uh the distance + + + align:start position:0% +we've proven that uh the distance +between pk plus one pk plus one plus l + + align:start position:0% +between pk plus one pk plus one plus l + + + align:start position:0% +between pk plus one pk plus one plus l +is less than uh epsilon + + align:start position:0% +is less than uh epsilon + + + align:start position:0% +is less than uh epsilon +k plus one um + + align:start position:0% +k plus one um + + + align:start position:0% +k plus one um +times three over two + + align:start position:0% + + + + align:start position:0% + +let me take the limit as l goes to + + align:start position:0% +let me take the limit as l goes to + + + align:start position:0% +let me take the limit as l goes to +infinity + + align:start position:0% + + + + align:start position:0% + +pk plus 1 plus l converges to the point + + align:start position:0% +pk plus 1 plus l converges to the point + + + align:start position:0% +pk plus 1 plus l converges to the point +p so i get that the distance + + align:start position:0% +p so i get that the distance + + + align:start position:0% +p so i get that the distance +between p k plus 1 + + align:start position:0% +between p k plus 1 + + + align:start position:0% +between p k plus 1 +and the point p + + align:start position:0% +and the point p + + + align:start position:0% +and the point p +is less than or equal to um + + align:start position:0% + + + + align:start position:0% + +three halves + + align:start position:0% +three halves + + + align:start position:0% +three halves +epsilon k plus one and remember epsilon + + align:start position:0% +epsilon k plus one and remember epsilon + + + align:start position:0% +epsilon k plus one and remember epsilon +k plus one is less than + + align:start position:0% +k plus one is less than + + + align:start position:0% +k plus one is less than +uh + + align:start position:0% +uh + + + align:start position:0% +uh +a third epsilon k so this is + + align:start position:0% +a third epsilon k so this is + + + align:start position:0% +a third epsilon k so this is +less than one half epsilon k + + align:start position:0% +less than one half epsilon k + + + align:start position:0% +less than one half epsilon k +all right + + align:start position:0% +all right + + + align:start position:0% +all right +and since pk plus one remember this is + + align:start position:0% +and since pk plus one remember this is + + + align:start position:0% +and since pk plus one remember this is +in the ball of radius one third epsilon + + align:start position:0% +in the ball of radius one third epsilon + + + align:start position:0% +in the ball of radius one third epsilon +k + + align:start position:0% +k + + + align:start position:0% +k +so i get that the distance between pk + + align:start position:0% +so i get that the distance between pk + + + align:start position:0% +so i get that the distance between pk +and p + + align:start position:0% +and p + + + align:start position:0% +and p +is + + align:start position:0% +is + + + align:start position:0% +is +less than or equal to + + align:start position:0% +less than or equal to + + + align:start position:0% +less than or equal to +the distance between pk and pk plus one + + align:start position:0% +the distance between pk and pk plus one + + + align:start position:0% +the distance between pk and pk plus one +plus + + align:start position:0% +plus + + + align:start position:0% +plus +plus one + + align:start position:0% +plus one + + + align:start position:0% +plus one +and p + + align:start position:0% +and p + + + align:start position:0% +and p +we get this is less than or equal to a + + align:start position:0% +we get this is less than or equal to a + + + align:start position:0% +we get this is less than or equal to a +third epsilon k + + align:start position:0% +third epsilon k + + + align:start position:0% +third epsilon k +plus a half epsilon k and this is less + + align:start position:0% +plus a half epsilon k and this is less + + + align:start position:0% +plus a half epsilon k and this is less +than + + align:start position:0% +than + + + align:start position:0% +than +epsilon k which means that + + align:start position:0% +epsilon k which means that + + + align:start position:0% +epsilon k which means that +p + + align:start position:0% +p + + + align:start position:0% +p +is in the ball of radius p k of radius + + align:start position:0% +is in the ball of radius p k of radius + + + align:start position:0% +is in the ball of radius p k of radius +epsilon k + + align:start position:0% + + + + align:start position:0% + +which + + align:start position:0% +which + + + align:start position:0% +which +by the second property up in star + + align:start position:0% + + + + align:start position:0% + +the fact that all these balls are + + align:start position:0% +the fact that all these balls are + + + align:start position:0% +the fact that all these balls are +disjoint from + + align:start position:0% +disjoint from + + + align:start position:0% +disjoint from +each of the balls that's disjoint from + + align:start position:0% +each of the balls that's disjoint from + + + align:start position:0% +each of the balls that's disjoint from +ck means p is not + + align:start position:0% +ck means p is not + + + align:start position:0% +ck means p is not +in ck now k was arbitrary here + + align:start position:0% +in ck now k was arbitrary here + + + align:start position:0% +in ck now k was arbitrary here +so + + align:start position:0% +so + + + align:start position:0% +so +we conclude that p + + align:start position:0% +we conclude that p + + + align:start position:0% +we conclude that p +is not in + + align:start position:0% +is not in + + + align:start position:0% +is not in +this union + + align:start position:0% +this union + + + align:start position:0% +this union +which gives me which is equal to m + + align:start position:0% +which gives me which is equal to m + + + align:start position:0% +which gives me which is equal to m +and that's a contradiction + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so i mean you know i said the strategy + + align:start position:0% +so i mean you know i said the strategy + + + align:start position:0% +so i mean you know i said the strategy +at the + + align:start position:0% +at the + + + align:start position:0% +at the +top of the proof + + align:start position:0% +top of the proof + + + align:start position:0% +top of the proof +you know we the technical argument maybe + + align:start position:0% +you know we the technical argument maybe + + + align:start position:0% +you know we the technical argument maybe +muddled what was going on but again the + + align:start position:0% +muddled what was going on but again the + + + align:start position:0% +muddled what was going on but again the +point is + + align:start position:0% + + + + align:start position:0% + +you know you can build + + align:start position:0% +you know you can build + + + align:start position:0% +you know you can build +if this conclusion does not hold you can + + align:start position:0% +if this conclusion does not hold you can + + + align:start position:0% +if this conclusion does not hold you can +build + + align:start position:0% +build + + + align:start position:0% +build +a sequence which has this uh + + align:start position:0% +a sequence which has this uh + + + align:start position:0% +a sequence which has this uh +disjointness property from this + + align:start position:0% +disjointness property from this + + + align:start position:0% +disjointness property from this +collection of open sets + + align:start position:0% +collection of open sets + + + align:start position:0% +collection of open sets +uh such that the sequence is koshi + + align:start position:0% +uh such that the sequence is koshi + + + align:start position:0% +uh such that the sequence is koshi +and because m is a complete metric space + + align:start position:0% +and because m is a complete metric space + + + align:start position:0% +and because m is a complete metric space +you can then extract a limit p this + + align:start position:0% +you can then extract a limit p this + + + align:start position:0% +you can then extract a limit p this +limit p will have all the properties + + align:start position:0% +limit p will have all the properties + + + align:start position:0% +limit p will have all the properties +that these pk's had namely that they're + + align:start position:0% +that these pk's had namely that they're + + + align:start position:0% +that these pk's had namely that they're +not in any of the c + + align:start position:0% +not in any of the c + + + align:start position:0% +not in any of the c +k's + + align:start position:0% +k's + + + align:start position:0% +k's +and therefore + + align:start position:0% +and therefore + + + align:start position:0% +and therefore +this point p does not lie in + + align:start position:0% +this point p does not lie in + + + align:start position:0% +this point p does not lie in +the metric space which is nonsense so we + + align:start position:0% +the metric space which is nonsense so we + + + align:start position:0% +the metric space which is nonsense so we +arrived at our contradiction and + + align:start position:0% +arrived at our contradiction and + + + align:start position:0% +arrived at our contradiction and +therefore + + align:start position:0% +therefore + + + align:start position:0% +therefore +bears category theorem is proven + + align:start position:0% + + + + align:start position:0% + +okay so + + align:start position:0% +okay so + + + align:start position:0% +okay so +that's uh + + align:start position:0% + + + + align:start position:0% + +let's bear categories theorem + + align:start position:0% +let's bear categories theorem + + + align:start position:0% +let's bear categories theorem +uh + + align:start position:0% + + + + align:start position:0% + +let's now use this to prove some some + + align:start position:0% +let's now use this to prove some some + + + align:start position:0% +let's now use this to prove some some +fundamental results of functional + + align:start position:0% +fundamental results of functional + + + align:start position:0% +fundamental results of functional +analysis so the first result we'll prove + + align:start position:0% +analysis so the first result we'll prove + + + align:start position:0% +analysis so the first result we'll prove +is + + align:start position:0% +is + + + align:start position:0% +is +what's called the uniform + + align:start position:0% + + + + align:start position:0% + +boundedness theorem + + align:start position:0% +boundedness theorem + + + align:start position:0% +boundedness theorem +which says that if you have a + + align:start position:0% +which says that if you have a + + + align:start position:0% +which says that if you have a +a sequence of linear bounded linear + + align:start position:0% +a sequence of linear bounded linear + + + align:start position:0% +a sequence of linear bounded linear +operators on a bonnet space + + align:start position:0% +operators on a bonnet space + + + align:start position:0% +operators on a bonnet space +then point wise boundedness implies sort + + align:start position:0% +then point wise boundedness implies sort + + + align:start position:0% +then point wise boundedness implies sort +of uniform boundedness + + align:start position:0% +of uniform boundedness + + + align:start position:0% +of uniform boundedness +okay + + align:start position:0% +okay + + + align:start position:0% +okay +or boundedness and a uniform boundedness + + align:start position:0% +or boundedness and a uniform boundedness + + + align:start position:0% +or boundedness and a uniform boundedness +in the operator norm + + align:start position:0% +in the operator norm + + + align:start position:0% +in the operator norm +so + + align:start position:0% +so + + + align:start position:0% +so +uh + + align:start position:0% +uh + + + align:start position:0% +uh +let b be + + align:start position:0% +let b be + + + align:start position:0% +let b be +bonux base + + align:start position:0% + + + + align:start position:0% + +and let t n + + align:start position:0% +and let t n + + + align:start position:0% +and let t n +be a sequence of bounded linear + + align:start position:0% +be a sequence of bounded linear + + + align:start position:0% +be a sequence of bounded linear +operators + + align:start position:0% + + + + align:start position:0% + +which we denoted last time by this + + align:start position:0% +which we denoted last time by this + + + align:start position:0% +which we denoted last time by this +script b + + align:start position:0% + + + + align:start position:0% + +to some other norm space v + + align:start position:0% +to some other norm space v + + + align:start position:0% +to some other norm space v +okay so i didn't write that but + + align:start position:0% +okay so i didn't write that but + + + align:start position:0% +okay so i didn't write that but +uh + + align:start position:0% +uh + + + align:start position:0% +uh +v is a norm space + + align:start position:0% + + + + align:start position:0% + +if + + align:start position:0% +if + + + align:start position:0% +if +for all b and capital b + + align:start position:0% + + + + align:start position:0% + +soup + + align:start position:0% +soup + + + align:start position:0% +soup +n + + align:start position:0% +n + + + align:start position:0% +n +of + + align:start position:0% +of + + + align:start position:0% +of +t n b + + align:start position:0% +t n b + + + align:start position:0% +t n b +norm + + align:start position:0% +norm + + + align:start position:0% +norm +is less than infinity so if i assume + + align:start position:0% +is less than infinity so if i assume + + + align:start position:0% +is less than infinity so if i assume +that + + align:start position:0% +that + + + align:start position:0% +that +this sequence is point wise bounded + + align:start position:0% +this sequence is point wise bounded + + + align:start position:0% +this sequence is point wise bounded +point-wise bounded + + align:start position:0% + + + + align:start position:0% + +then i can conclude that they're + + align:start position:0% +then i can conclude that they're + + + align:start position:0% +then i can conclude that they're +uniformly bounded namely the soup of the + + align:start position:0% +uniformly bounded namely the soup of the + + + align:start position:0% +uniformly bounded namely the soup of the +operator norms + + align:start position:0% + + + + align:start position:0% + +are bounded + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +all right + + align:start position:0% + + + + align:start position:0% + +so we're going to use the bear category + + align:start position:0% +so we're going to use the bear category + + + align:start position:0% +so we're going to use the bear category +theorem so we're going to write + + align:start position:0% +theorem so we're going to write + + + align:start position:0% +theorem so we're going to write +the binocular space b as a union of + + align:start position:0% +the binocular space b as a union of + + + align:start position:0% +the binocular space b as a union of +closed subsets what will be these closed + + align:start position:0% +closed subsets what will be these closed + + + align:start position:0% +closed subsets what will be these closed +subsets remember we're trying to find + + align:start position:0% +subsets remember we're trying to find + + + align:start position:0% +subsets remember we're trying to find +kind of a uniform + + align:start position:0% +kind of a uniform + + + align:start position:0% +kind of a uniform +bound on + + align:start position:0% +bound on + + + align:start position:0% +bound on +on the t end so + + align:start position:0% +on the t end so + + + align:start position:0% +on the t end so +kind of just playing around so let's + + align:start position:0% + + + + align:start position:0% + +define + + align:start position:0% +define + + + align:start position:0% +define +subset of b to be ck this is a set of + + align:start position:0% +subset of b to be ck this is a set of + + + align:start position:0% +subset of b to be ck this is a set of +all + + align:start position:0% +all + + + align:start position:0% +all +elements b and b + + align:start position:0% + + + + align:start position:0% + +such that the norm of b + + align:start position:0% +such that the norm of b + + + align:start position:0% +such that the norm of b +is less than or equal to 1 + + align:start position:0% +is less than or equal to 1 + + + align:start position:0% +is less than or equal to 1 +and + + align:start position:0% +and + + + align:start position:0% +and +soup n + + align:start position:0% +soup n + + + align:start position:0% +soup n +t n of b + + align:start position:0% +t n of b + + + align:start position:0% +t n of b +is less than or equal to k + + align:start position:0% + + + + align:start position:0% + +all right + + align:start position:0% + + + + align:start position:0% + +all right + + align:start position:0% +all right + + + align:start position:0% +all right +so first off + + align:start position:0% +so first off + + + align:start position:0% +so first off +uh these are closed + + align:start position:0% + + + + align:start position:0% + +so i should say what is k k here is a + + align:start position:0% +so i should say what is k k here is a + + + align:start position:0% +so i should say what is k k here is a +natural number + + align:start position:0% +natural number + + + align:start position:0% +natural number +ck is closed why is this well we need to + + align:start position:0% +ck is closed why is this well we need to + + + align:start position:0% +ck is closed why is this well we need to +show that a sequence converging a + + align:start position:0% +show that a sequence converging a + + + align:start position:0% +show that a sequence converging a +sequence of elements from ck that + + align:start position:0% +sequence of elements from ck that + + + align:start position:0% +sequence of elements from ck that +converges converges to an element of ck + + align:start position:0% +converges converges to an element of ck + + + align:start position:0% +converges converges to an element of ck +so + + align:start position:0% +so + + + align:start position:0% +so +if + + align:start position:0% +if + + + align:start position:0% +if +bn + + align:start position:0% +bn + + + align:start position:0% +bn +this is a sequence of elements in ck + + align:start position:0% +this is a sequence of elements in ck + + + align:start position:0% +this is a sequence of elements in ck +and b n converges to b + + align:start position:0% +and b n converges to b + + + align:start position:0% +and b n converges to b +then + + align:start position:0% + + + + align:start position:0% + +the norm + + align:start position:0% +the norm + + + align:start position:0% +the norm +of b is equal to limit as n goes to + + align:start position:0% +of b is equal to limit as n goes to + + + align:start position:0% +of b is equal to limit as n goes to +infinity of the norm of b n + + align:start position:0% +infinity of the norm of b n + + + align:start position:0% +infinity of the norm of b n +um and each of these is less than or + + align:start position:0% +um and each of these is less than or + + + align:start position:0% +um and each of these is less than or +equal to one so + + align:start position:0% +equal to one so + + + align:start position:0% +equal to one so +the limit has to be less than or equal + + align:start position:0% +the limit has to be less than or equal + + + align:start position:0% +the limit has to be less than or equal +to one + + align:start position:0% +to one + + + align:start position:0% +to one +okay + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +um + + align:start position:0% +um + + + align:start position:0% +um +so i shouldn't + + align:start position:0% +so i shouldn't + + + align:start position:0% +so i shouldn't +maybe i'll use a + + align:start position:0% +maybe i'll use a + + + align:start position:0% +maybe i'll use a +and the tns i have the b n so let me uh + + align:start position:0% +and the tns i have the b n so let me uh + + + align:start position:0% +and the tns i have the b n so let me uh +use m + + align:start position:0% +use m + + + align:start position:0% +use m +and for all + + align:start position:0% +and for all + + + align:start position:0% +and for all +m a natural number + + align:start position:0% +m a natural number + + + align:start position:0% +m a natural number +t m + + align:start position:0% +t m + + + align:start position:0% +t m +applied to b and norm + + align:start position:0% +applied to b and norm + + + align:start position:0% +applied to b and norm +this is equal to the limit + + align:start position:0% +this is equal to the limit + + + align:start position:0% +this is equal to the limit +as n goes to infinity of + + align:start position:0% +as n goes to infinity of + + + align:start position:0% +as n goes to infinity of +t m + + align:start position:0% +t m + + + align:start position:0% +t m +b n + + align:start position:0% +b n + + + align:start position:0% +b n +in norm because these are bounded linear + + align:start position:0% +in norm because these are bounded linear + + + align:start position:0% +in norm because these are bounded linear +operators and therefore + + align:start position:0% +operators and therefore + + + align:start position:0% +operators and therefore +continuous + + align:start position:0% +continuous + + + align:start position:0% +continuous +[Applause] + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +okay so + + align:start position:0% + + + + align:start position:0% + +tm of b is equal to the limit as n goes + + align:start position:0% +tm of b is equal to the limit as n goes + + + align:start position:0% +tm of b is equal to the limit as n goes +to infinity of t m of b + + align:start position:0% +to infinity of t m of b + + + align:start position:0% +to infinity of t m of b +n okay + + align:start position:0% +n okay + + + align:start position:0% +n okay +and now + + align:start position:0% +and now + + + align:start position:0% +and now +the norm of tm + + align:start position:0% +the norm of tm + + + align:start position:0% +the norm of tm +of bn is always well this is always less + + align:start position:0% +of bn is always well this is always less + + + align:start position:0% +of bn is always well this is always less +than or equal to k + + align:start position:0% +than or equal to k + + + align:start position:0% +than or equal to k +because the b ends are in c k + + align:start position:0% +because the b ends are in c k + + + align:start position:0% +because the b ends are in c k +and soup of all these guys is less than + + align:start position:0% +and soup of all these guys is less than + + + align:start position:0% +and soup of all these guys is less than +or equal to k so + + align:start position:0% +or equal to k so + + + align:start position:0% +or equal to k so +that's also less than or equal to k + + align:start position:0% +that's also less than or equal to k + + + align:start position:0% +that's also less than or equal to k +all right + + align:start position:0% + + + + align:start position:0% + +thus + + align:start position:0% + + + + align:start position:0% + +e is in ck which implies ck + + align:start position:0% + + + + align:start position:0% + +is closed + + align:start position:0% +is closed + + + align:start position:0% +is closed +okay + + align:start position:0% + + + + align:start position:0% + +now + + align:start position:0% +now + + + align:start position:0% +now +the closed ball + + align:start position:0% +the closed ball + + + align:start position:0% +the closed ball +or i shouldn't say it's not the closure + + align:start position:0% +or i shouldn't say it's not the closure + + + align:start position:0% +or i shouldn't say it's not the closure +of the open ball but the closed ball + + align:start position:0% +of the open ball but the closed ball + + + align:start position:0% +of the open ball but the closed ball +b in capital b such that + + align:start position:0% +b in capital b such that + + + align:start position:0% +b in capital b such that +b is less than or equal to one this is + + align:start position:0% +b is less than or equal to one this is + + + align:start position:0% +b is less than or equal to one this is +equal to the union + + align:start position:0% +equal to the union + + + align:start position:0% +equal to the union +over all k of c k y + + align:start position:0% +over all k of c k y + + + align:start position:0% +over all k of c k y +um + + align:start position:0% +um + + + align:start position:0% +um +so first off each of these is contained + + align:start position:0% +so first off each of these is contained + + + align:start position:0% +so first off each of these is contained +in this close ball but i'm assuming by + + align:start position:0% +in this close ball but i'm assuming by + + + align:start position:0% +in this close ball but i'm assuming by +star that + + align:start position:0% +star that + + + align:start position:0% +star that +uh no matter what b is in the bonnet + + align:start position:0% +uh no matter what b is in the bonnet + + + align:start position:0% +uh no matter what b is in the bonnet +space + + align:start position:0% +space + + + align:start position:0% +space +soup over n of these is less than + + align:start position:0% +soup over n of these is less than + + + align:start position:0% +soup over n of these is less than +infinity so there's always + + align:start position:0% +infinity so there's always + + + align:start position:0% +infinity so there's always +some integer k + + align:start position:0% +some integer k + + + align:start position:0% +some integer k +given a b so given a certain b in this + + align:start position:0% +given a b so given a certain b in this + + + align:start position:0% +given a b so given a certain b in this +set i can always find a large enough + + align:start position:0% +set i can always find a large enough + + + align:start position:0% +set i can always find a large enough +integer + + align:start position:0% +integer + + + align:start position:0% +integer +such that this + + align:start position:0% +such that this + + + align:start position:0% +such that this +is less than + + align:start position:0% +is less than + + + align:start position:0% +is less than +uh that integer so it has to + + align:start position:0% +uh that integer so it has to + + + align:start position:0% +uh that integer so it has to +every element in here has to lie in one + + align:start position:0% +every element in here has to lie in one + + + align:start position:0% +every element in here has to lie in one +of these sets c sub k so + + align:start position:0% +of these sets c sub k so + + + align:start position:0% +of these sets c sub k so +this is equal to the union + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +this uh + + align:start position:0% +this uh + + + align:start position:0% +this uh +is a complete metric space because it's + + align:start position:0% +is a complete metric space because it's + + + align:start position:0% +is a complete metric space because it's +a closed subset of m so + + align:start position:0% + + + + align:start position:0% + +this is a + + align:start position:0% + + + + align:start position:0% + +complete + + align:start position:0% +complete + + + align:start position:0% +complete +metric space + + align:start position:0% +metric space + + + align:start position:0% +metric space +written as the union of + + align:start position:0% +written as the union of + + + align:start position:0% +written as the union of +a sub uh union of closed subsets so by + + align:start position:0% +a sub uh union of closed subsets so by + + + align:start position:0% +a sub uh union of closed subsets so by +bears + + align:start position:0% +bears + + + align:start position:0% +bears +theorem + + align:start position:0% + + + + align:start position:0% + +there exists + + align:start position:0% +there exists + + + align:start position:0% +there exists +one of these sets containing an open + + align:start position:0% +one of these sets containing an open + + + align:start position:0% +one of these sets containing an open +ball + + align:start position:0% + + + + align:start position:0% + +of the form b naught + + align:start position:0% +of the form b naught + + + align:start position:0% +of the form b naught +delta naught + + align:start position:0% + + + + align:start position:0% + +so one of these c k's uh + + align:start position:0% +so one of these c k's uh + + + align:start position:0% +so one of these c k's uh +contains an open ball now we're going to + + align:start position:0% +contains an open ball now we're going to + + + align:start position:0% +contains an open ball now we're going to +show we're going to use this k and to + + align:start position:0% +show we're going to use this k and to + + + align:start position:0% +show we're going to use this k and to +derive a uniform bound + + align:start position:0% +derive a uniform bound + + + align:start position:0% +derive a uniform bound +so + + align:start position:0% +so + + + align:start position:0% +so +if + + align:start position:0% +if + + + align:start position:0% +if +e is in b + + align:start position:0% +e is in b + + + align:start position:0% +e is in b +and + + align:start position:0% +and + + + align:start position:0% +and +let's see + + align:start position:0% + + + + align:start position:0% + +so let's write it this way + + align:start position:0% + + + + align:start position:0% + +if b is in + + align:start position:0% + + + + align:start position:0% + +the open ball + + align:start position:0% +the open ball + + + align:start position:0% +the open ball +of radius delta 0 centered at 0. so this + + align:start position:0% +of radius delta 0 centered at 0. so this + + + align:start position:0% +of radius delta 0 centered at 0. so this +means + + align:start position:0% +means + + + align:start position:0% +means +ie the + + align:start position:0% +ie the + + + align:start position:0% +ie the +norm of b is less than delta 0 + + align:start position:0% + + + + align:start position:0% + +then + + align:start position:0% +then + + + align:start position:0% +then +b naught plus b + + align:start position:0% +b naught plus b + + + align:start position:0% +b naught plus b +is in + + align:start position:0% + + + + align:start position:0% + +this open ball uh + + align:start position:0% +this open ball uh + + + align:start position:0% +this open ball uh +centered at b naught + + align:start position:0% + + + + align:start position:0% + +and therefore uh + + align:start position:0% + + + + align:start position:0% + +soup n of + + align:start position:0% +soup n of + + + align:start position:0% +soup n of +t n + + align:start position:0% +t n + + + align:start position:0% +t n +of b naught plus b + + align:start position:0% +of b naught plus b + + + align:start position:0% +of b naught plus b +norm is less than or equal to + + align:start position:0% +norm is less than or equal to + + + align:start position:0% +norm is less than or equal to +k all right so this ball is contained in + + align:start position:0% +k all right so this ball is contained in + + + align:start position:0% +k all right so this ball is contained in +c k and therefore if i take the soup + + align:start position:0% +c k and therefore if i take the soup + + + align:start position:0% +c k and therefore if i take the soup +over n of t sub n applied to this thing + + align:start position:0% +over n of t sub n applied to this thing + + + align:start position:0% +over n of t sub n applied to this thing +this is less than or equal to k + + align:start position:0% +this is less than or equal to k + + + align:start position:0% +this is less than or equal to k +all right + + align:start position:0% + + + + align:start position:0% + +but then i conclude that + + align:start position:0% +but then i conclude that + + + align:start position:0% +but then i conclude that +soup over n + + align:start position:0% +soup over n + + + align:start position:0% +soup over n +of tn applied to b + + align:start position:0% +of tn applied to b + + + align:start position:0% +of tn applied to b +which is less than or equal to soup n + + align:start position:0% +which is less than or equal to soup n + + + align:start position:0% +which is less than or equal to soup n +so i'm gonna add and subtract b zero + + align:start position:0% +so i'm gonna add and subtract b zero + + + align:start position:0% +so i'm gonna add and subtract b zero +okay + + align:start position:0% +okay + + + align:start position:0% +okay +um + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +let me actually write this as soup + + align:start position:0% +let me actually write this as soup + + + align:start position:0% +let me actually write this as soup +of t and + + align:start position:0% +of t and + + + align:start position:0% +of t and +b zero plus + + align:start position:0% + + + + align:start position:0% + +t n + + align:start position:0% +t n + + + align:start position:0% +t n +b 0 plus b + + align:start position:0% +b 0 plus b + + + align:start position:0% +b 0 plus b +this is + + align:start position:0% +this is + + + align:start position:0% +this is +less than or equal to by the triangle + + align:start position:0% +less than or equal to by the triangle + + + align:start position:0% +less than or equal to by the triangle +inequality + + align:start position:0% +inequality + + + align:start position:0% +inequality +and then carrying the soup through this + + align:start position:0% +and then carrying the soup through this + + + align:start position:0% +and then carrying the soup through this +is less than or equal to soup n + + align:start position:0% +is less than or equal to soup n + + + align:start position:0% +is less than or equal to soup n +t n b 0 + + align:start position:0% +t n b 0 + + + align:start position:0% +t n b 0 +plus + + align:start position:0% +plus + + + align:start position:0% +plus +soup n + + align:start position:0% +soup n + + + align:start position:0% +soup n +t n + + align:start position:0% +t n + + + align:start position:0% +t n +d 0 plus b + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +so b0 + + align:start position:0% +so b0 + + + align:start position:0% +so b0 +is certainly in this ball which is + + align:start position:0% +is certainly in this ball which is + + + align:start position:0% +is certainly in this ball which is +contained in ck + + align:start position:0% +contained in ck + + + align:start position:0% +contained in ck +so this is less than or equal to + + align:start position:0% + + + + align:start position:0% + +okay and this is still in that ball um + + align:start position:0% +okay and this is still in that ball um + + + align:start position:0% +okay and this is still in that ball um +of radius delta 0 centered at b0 so it + + align:start position:0% +of radius delta 0 centered at b0 so it + + + align:start position:0% +of radius delta 0 centered at b0 so it +lies in ck + + align:start position:0% +lies in ck + + + align:start position:0% +lies in ck +and therefore this soup is also less + + align:start position:0% +and therefore this soup is also less + + + align:start position:0% +and therefore this soup is also less +than or equal to k equals 2k + + align:start position:0% +than or equal to k equals 2k + + + align:start position:0% +than or equal to k equals 2k +so i've shown + + align:start position:0% +so i've shown + + + align:start position:0% +so i've shown +that if i take any element in the open + + align:start position:0% +that if i take any element in the open + + + align:start position:0% +that if i take any element in the open +ball + + align:start position:0% +ball + + + align:start position:0% +ball +of radius delta 0 + + align:start position:0% + + + + align:start position:0% + +then the soup over n of t n of b + + align:start position:0% + + + + align:start position:0% + +is less than or equal to 2k + + align:start position:0% +is less than or equal to 2k + + + align:start position:0% +is less than or equal to 2k +all right + + align:start position:0% +all right + + + align:start position:0% +all right +and now it's just a simple rescaling + + align:start position:0% +and now it's just a simple rescaling + + + align:start position:0% +and now it's just a simple rescaling +argument to show that the soup of the + + align:start position:0% +argument to show that the soup of the + + + align:start position:0% +argument to show that the soup of the +norms are now bounded so + + align:start position:0% + + + + align:start position:0% + +suppose norm of b + + align:start position:0% +suppose norm of b + + + align:start position:0% +suppose norm of b +equals 1 + + align:start position:0% +equals 1 + + + align:start position:0% +equals 1 +then + + align:start position:0% + + + + align:start position:0% + +the norm of + + align:start position:0% +the norm of + + + align:start position:0% +the norm of +tn of + + align:start position:0% +tn of + + + align:start position:0% +tn of +delta 0 over 2 + + align:start position:0% +delta 0 over 2 + + + align:start position:0% +delta 0 over 2 +applied to b + + align:start position:0% + + + + align:start position:0% + +is less than or equal to + + align:start position:0% + + + + align:start position:0% + +so for all n + + align:start position:0% +so for all n + + + align:start position:0% +so for all n +certainly less than or equal to the soup + + align:start position:0% +certainly less than or equal to the soup + + + align:start position:0% +certainly less than or equal to the soup +over n of all of these which is less + + align:start position:0% +over n of all of these which is less + + + align:start position:0% +over n of all of these which is less +than or equal to 2k because this is an + + align:start position:0% +than or equal to 2k because this is an + + + align:start position:0% +than or equal to 2k because this is an +element with norm delta 0 over 2 which + + align:start position:0% +element with norm delta 0 over 2 which + + + align:start position:0% +element with norm delta 0 over 2 which +is less than delta 0 so this is less + + align:start position:0% +is less than delta 0 so this is less + + + align:start position:0% +is less than delta 0 so this is less +than or equal to 2k + + align:start position:0% +than or equal to 2k + + + align:start position:0% +than or equal to 2k +which implies + + align:start position:0% +which implies + + + align:start position:0% +which implies +so again tn is linear so + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% +um + + + align:start position:0% +um +i should have reversed this + + align:start position:0% + + + + align:start position:0% + +let n be a natural number + + align:start position:0% + + + + align:start position:0% + +let b + + align:start position:0% +let b + + + align:start position:0% +let b +equal to one + + align:start position:0% +equal to one + + + align:start position:0% +equal to one +then okay + + align:start position:0% +then okay + + + align:start position:0% +then okay +so then t n applied to b is less than or + + align:start position:0% +so then t n applied to b is less than or + + + align:start position:0% +so then t n applied to b is less than or +equal to uh four k over delta zero + + align:start position:0% +equal to uh four k over delta zero + + + align:start position:0% +equal to uh four k over delta zero +now this holds for all b with uh length + + align:start position:0% +now this holds for all b with uh length + + + align:start position:0% +now this holds for all b with uh length +equal to one + + align:start position:0% +equal to one + + + align:start position:0% +equal to one +and therefore the operator norm which is + + align:start position:0% +and therefore the operator norm which is + + + align:start position:0% +and therefore the operator norm which is +the soup over all b + + align:start position:0% +the soup over all b + + + align:start position:0% +the soup over all b +with norm equal to one is less than or + + align:start position:0% +with norm equal to one is less than or + + + align:start position:0% +with norm equal to one is less than or +equal to four k + + align:start position:0% +equal to four k + + + align:start position:0% +equal to four k +over delta zero this holds for all n and + + align:start position:0% +over delta zero this holds for all n and + + + align:start position:0% +over delta zero this holds for all n and +therefore the soup + + align:start position:0% +therefore the soup + + + align:start position:0% +therefore the soup +over n + + align:start position:0% +over n + + + align:start position:0% +over n +of the operator norm is less than or + + align:start position:0% +of the operator norm is less than or + + + align:start position:0% +of the operator norm is less than or +equal to 4k + + align:start position:0% +equal to 4k + + + align:start position:0% +equal to 4k +over delta 0 and therefore + + align:start position:0% +over delta 0 and therefore + + + align:start position:0% +over delta 0 and therefore +giving us the uniform bound + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% +um + + + align:start position:0% +um +i have time for this + + align:start position:0% + + + + align:start position:0% + +okay i don't think i have time for + + align:start position:0% +okay i don't think i have time for + + + align:start position:0% +okay i don't think i have time for +the entire proof of what's uh what's to + + align:start position:0% +the entire proof of what's uh what's to + + + align:start position:0% +the entire proof of what's uh what's to +come + + align:start position:0% +come + + + align:start position:0% +come +so i think we'll just stop there for now + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/5Pw5k0z1L4Q.txt b/5Pw5k0z1L4Q.txt new file mode 100644 index 0000000000000000000000000000000000000000..0e22cbc8adee88805ecceb633e75f6818221cb5c --- /dev/null +++ b/5Pw5k0z1L4Q.txt @@ -0,0 +1,8395 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +to view additional materials from + + align:start position:0% +to view additional materials from + + + align:start position:0% +to view additional materials from +hundreds of MIT courses visit MIT open + + align:start position:0% +hundreds of MIT courses visit MIT open + + + align:start position:0% +hundreds of MIT courses visit MIT open +courseware at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu okay so uh this is I could + + align:start position:0% +ocw.mit.edu okay so uh this is I could + + + align:start position:0% +ocw.mit.edu okay so uh this is I could +say Delta function day uh break from + + align:start position:0% +say Delta function day uh break from + + + align:start position:0% +say Delta function day uh break from +linear algebra mostly uh uh so it's + + align:start position:0% +linear algebra mostly uh uh so it's + + + align:start position:0% +linear algebra mostly uh uh so it's +we're looking at another type of right + + align:start position:0% +we're looking at another type of right + + + align:start position:0% +we're looking at another type of right +hand side before in the differential + + align:start position:0% +hand side before in the differential + + + align:start position:0% +hand side before in the differential +equation and in the difference equation + + align:start position:0% +equation and in the difference equation + + + align:start position:0% +equation and in the difference equation +so the right hand sides up to now uh the + + align:start position:0% +so the right hand sides up to now uh the + + + align:start position:0% +so the right hand sides up to now uh the +one we looked at was a + + align:start position:0% +one we looked at was a + + + align:start position:0% +one we looked at was a +uniform uh constant load second + + align:start position:0% +uniform uh constant load second + + + align:start position:0% +uniform uh constant load second +derivative equal one now uh a point + + align:start position:0% +derivative equal one now uh a point + + + align:start position:0% +derivative equal one now uh a point +load well in a way we're now solving a + + align:start position:0% +load well in a way we're now solving a + + + align:start position:0% +load well in a way we're now solving a +whole bunch of problems because the + + align:start position:0% +whole bunch of problems because the + + + align:start position:0% +whole bunch of problems because the +point load + + align:start position:0% +point load + + + align:start position:0% +point load +can be in different places so instead of + + align:start position:0% +can be in different places so instead of + + + align:start position:0% +can be in different places so instead of +solving one problem with with one on the + + align:start position:0% +solving one problem with with one on the + + + align:start position:0% +solving one problem with with one on the +right hand side we're solving with a + + align:start position:0% +right hand side we're solving with a + + + align:start position:0% +right hand side we're solving with a +Delta function okay now a Delta function + + align:start position:0% +Delta function okay now a Delta function + + + align:start position:0% +Delta function okay now a Delta function +is you you probably have seen the and + + align:start position:0% +is you you probably have seen the and + + + align:start position:0% +is you you probably have seen the and +heard the words and seen the symbol but + + align:start position:0% +heard the words and seen the symbol but + + + align:start position:0% +heard the words and seen the symbol but +uh maybe not done much with a Delta + + align:start position:0% +uh maybe not done much with a Delta + + + align:start position:0% +uh maybe not done much with a Delta +function so let's uh it takes a little + + align:start position:0% +function so let's uh it takes a little + + + align:start position:0% +function so let's uh it takes a little +practice but it's really worth it uh + + align:start position:0% +practice but it's really worth it uh + + + align:start position:0% +practice but it's really worth it uh +it's a great model of uh maybe what + + align:start position:0% +it's a great model of uh maybe what + + + align:start position:0% +it's a great model of uh maybe what +can't quite happen physically to have a + + align:start position:0% +can't quite happen physically to have a + + + align:start position:0% +can't quite happen physically to have a +load acting exactly at a point and + + align:start position:0% +load acting exactly at a point and + + + align:start position:0% +load acting exactly at a point and +nowhere else so the Delta function is + + align:start position:0% +nowhere else so the Delta function is + + + align:start position:0% +nowhere else so the Delta function is +let's I drew its picture the Delta + + align:start position:0% +let's I drew its picture the Delta + + + align:start position:0% +let's I drew its picture the Delta +function is zero this is Delta of X is + + align:start position:0% +function is zero this is Delta of X is + + + align:start position:0% +function is zero this is Delta of X is +zero except at that one point the origin + + align:start position:0% +zero except at that one point the origin + + + align:start position:0% +zero except at that one point the origin +x equals z and then along and back to + + align:start position:0% +x equals z and then along and back to + + + align:start position:0% +x equals z and then along and back to +zero again so nothing's happening no + + align:start position:0% +zero again so nothing's happening no + + + align:start position:0% +zero again so nothing's happening no +load uh except at that one point + + align:start position:0% +load uh except at that one point + + + align:start position:0% +load uh except at that one point +and let me just uh so there's no uh + + align:start position:0% +and let me just uh so there's no uh + + + align:start position:0% +and let me just uh so there's no uh +hesitation in when I change the from X + + align:start position:0% +hesitation in when I change the from X + + + align:start position:0% +hesitation in when I change the from X +to x minus a what does that do to a + + align:start position:0% +to x minus a what does that do to a + + + align:start position:0% +to x minus a what does that do to a +graph if I have a function of X and I + + align:start position:0% +graph if I have a function of X and I + + + align:start position:0% +graph if I have a function of X and I +instead think look at the shift the + + align:start position:0% +instead think look at the shift the + + + align:start position:0% +instead think look at the shift the +function to f of x minus a I shift X to + + align:start position:0% +function to f of x minus a I shift X to + + + align:start position:0% +function to f of x minus a I shift X to +x - a well in this case and in all cases + + align:start position:0% +x - a well in this case and in all cases + + + align:start position:0% +x - a well in this case and in all cases +it will just shift the graph so if I + + align:start position:0% +it will just shift the graph so if I + + + align:start position:0% +it will just shift the graph so if I +drew a picture of Delta of xus + + align:start position:0% +drew a picture of Delta of xus + + + align:start position:0% +drew a picture of Delta of xus +a the load now would happen when this is + + align:start position:0% +a the load now would happen when this is + + + align:start position:0% +a the load now would happen when this is +zero because it's Delta at zero is the + + align:start position:0% +zero because it's Delta at zero is the + + + align:start position:0% +zero because it's Delta at zero is the +impulse and now this is zero at x equal + + align:start position:0% +impulse and now this is zero at x equal + + + align:start position:0% +impulse and now this is zero at x equal +a in other words the load moved to the + + align:start position:0% +a in other words the load moved to the + + + align:start position:0% +a in other words the load moved to the +point a so there's a there's the the + + align:start position:0% +point a so there's a there's the the + + + align:start position:0% +point a so there's a there's the the +shifting load but the load could fall + + align:start position:0% +shifting load but the load could fall + + + align:start position:0% +shifting load but the load could fall +anywhere between 0 and + + align:start position:0% +anywhere between 0 and + + + align:start position:0% +anywhere between 0 and +one okay so Delta of X the load actually + + align:start position:0% +one okay so Delta of X the load actually + + + align:start position:0% +one okay so Delta of X the load actually +falls at zero well we don't quite want + + align:start position:0% +falls at zero well we don't quite want + + + align:start position:0% +falls at zero well we don't quite want +that load at the boundary so let's think + + align:start position:0% +that load at the boundary so let's think + + + align:start position:0% +that load at the boundary so let's think +of the point a the load point is + + align:start position:0% +of the point a the load point is + + + align:start position:0% +of the point a the load point is +somewhere between Zer and one okay can I + + align:start position:0% +somewhere between Zer and one okay can I + + + align:start position:0% +somewhere between Zer and one okay can I +just take a little time to recall the + + align:start position:0% +just take a little time to recall the + + + align:start position:0% +just take a little time to recall the +main facts about Delta functions well + + align:start position:0% +main facts about Delta functions well + + + align:start position:0% +main facts about Delta functions well +when I say recall I it could very well + + align:start position:0% +when I say recall I it could very well + + + align:start position:0% +when I say recall I it could very well +be new to you okay so that's what the + + align:start position:0% +be new to you okay so that's what the + + + align:start position:0% +be new to you okay so that's what the +Delta function that's my best graph of + + align:start position:0% +Delta function that's my best graph of + + + align:start position:0% +Delta function that's my best graph of +the Delta function but of course I'm in + + align:start position:0% +the Delta function but of course I'm in + + + align:start position:0% +the Delta function but of course I'm in +using the word function I'm kind of + + align:start position:0% +using the word function I'm kind of + + + align:start position:0% +using the word function I'm kind of +breaking the rules because no function I + + align:start position:0% +breaking the rules because no function I + + + align:start position:0% +breaking the rules because no function I +mean the function is functions can be + + align:start position:0% +mean the function is functions can be + + + align:start position:0% +mean the function is functions can be +zero there can be zero there but they're + + align:start position:0% +zero there can be zero there but they're + + + align:start position:0% +zero there can be zero there but they're +not supposed to be + + align:start position:0% +not supposed to be + + + align:start position:0% +not supposed to be +infinite at a single point in between + + align:start position:0% +infinite at a single point in between + + + align:start position:0% +infinite at a single point in between +but this one is let me go back to Delta + + align:start position:0% +but this one is let me go back to Delta + + + align:start position:0% +but this one is let me go back to Delta +of x to match the uh these figures + + align:start position:0% +of x to match the uh these figures + + + align:start position:0% +of x to match the uh these figures +of course they would also just shift + + align:start position:0% +of course they would also just shift + + + align:start position:0% +of course they would also just shift +Along by a Maybe yeah maybe no harm in + + align:start position:0% +Along by a Maybe yeah maybe no harm in + + + align:start position:0% +Along by a Maybe yeah maybe no harm in +that I I'll I'll sorry + + align:start position:0% +that I I'll I'll sorry + + + align:start position:0% +that I I'll I'll sorry +I'll I'll stay there and now I want to + + align:start position:0% +I'll I'll stay there and now I want to + + + align:start position:0% +I'll I'll stay there and now I want to +integrate it and that's when a Delta + + align:start position:0% +integrate it and that's when a Delta + + + align:start position:0% +integrate it and that's when a Delta +function comes to into its own it's it's + + align:start position:0% +function comes to into its own it's it's + + + align:start position:0% +function comes to into its own it's it's +it's its value of infinity is a little + + align:start position:0% +it's its value of infinity is a little + + + align:start position:0% +it's its value of infinity is a little +bit uncertain what does that mean but + + align:start position:0% +bit uncertain what does that mean but + + + align:start position:0% +bit uncertain what does that mean but +when we integrate it what's the key fact + + align:start position:0% +when we integrate it what's the key fact + + + align:start position:0% +when we integrate it what's the key fact +about Delta function that the integral + + align:start position:0% +about Delta function that the integral + + + align:start position:0% +about Delta function that the integral +of a Delta + + align:start position:0% +of a Delta + + + align:start position:0% +of a Delta +function from let's say let's integrate + + align:start position:0% +function from let's say let's integrate + + + align:start position:0% +function from let's say let's integrate +the whole thing we can safely start way + + align:start position:0% +the whole thing we can safely start way + + + align:start position:0% +the whole thing we can safely start way +at the far left and go way to the far + + align:start position:0% +at the far left and go way to the far + + + align:start position:0% +at the far left and go way to the far +right because it's zero all the time + + align:start position:0% +right because it's zero all the time + + + align:start position:0% +right because it's zero all the time +there except at one point and you know + + align:start position:0% +there except at one point and you know + + + align:start position:0% +there except at one point and you know +so what's the area under that spike it + + align:start position:0% +so what's the area under that spike it + + + align:start position:0% +so what's the area under that spike it +is one that's right so that's the fact + + align:start position:0% +is one that's right so that's the fact + + + align:start position:0% +is one that's right so that's the fact +the sort of central fact about a Delta + + align:start position:0% +the sort of central fact about a Delta + + + align:start position:0% +the sort of central fact about a Delta +function + + align:start position:0% +function + + + align:start position:0% +function +that the area is one oh well let me + + align:start position:0% +that the area is one oh well let me + + + align:start position:0% +that the area is one oh well let me +while I'm really writing down the + + align:start position:0% +while I'm really writing down the + + + align:start position:0% +while I'm really writing down the +central fact let me write let me write + + align:start position:0% +central fact let me write let me write + + + align:start position:0% +central fact let me write let me write +it more specifically more more yeah more + + align:start position:0% +it more specifically more more yeah more + + + align:start position:0% +it more specifically more more yeah more +more uh generally suppose I integrate + + align:start position:0% +more uh generally suppose I integrate + + + align:start position:0% +more uh generally suppose I integrate +and this is Delta functions now really + + align:start position:0% +and this is Delta functions now really + + + align:start position:0% +and this is Delta functions now really +showing up if I integrate a Delta + + align:start position:0% +showing up if I integrate a Delta + + + align:start position:0% +showing up if I integrate a Delta +function against some times some nice + + align:start position:0% +function against some times some nice + + + align:start position:0% +function against some times some nice +function now have you ever thought about + + align:start position:0% +function now have you ever thought about + + + align:start position:0% +function now have you ever thought about +that what will be the answer if I + + align:start position:0% +that what will be the answer if I + + + align:start position:0% +that what will be the answer if I +integrate the Delta function against + + align:start position:0% +integrate the Delta function against + + + align:start position:0% +integrate the Delta function against +some nice function okay so I'm still + + align:start position:0% +some nice function okay so I'm still + + + align:start position:0% +some nice function okay so I'm still +getting Zero from this + + align:start position:0% +getting Zero from this + + + align:start position:0% +getting Zero from this +term all the way along until I hit the + + align:start position:0% +term all the way along until I hit the + + + align:start position:0% +term all the way along until I hit the +spike and then after it goes back to + + align:start position:0% +spike and then after it goes back to + + + align:start position:0% +spike and then after it goes back to +zero again so + + align:start position:0% +zero again so + + + align:start position:0% +zero again so +whatever it's got to be at the spike at + + align:start position:0% +whatever it's got to be at the spike at + + + align:start position:0% +whatever it's got to be at the spike at +x equals zero because I'm put the spike + + align:start position:0% +x equals zero because I'm put the spike + + + align:start position:0% +x equals zero because I'm put the spike +here at zero the impulse so what do you + + align:start position:0% +here at zero the impulse so what do you + + + align:start position:0% +here at zero the impulse so what do you +think's the answer for that that + + align:start position:0% + + + + align:start position:0% + +one yeah it's the function so the yeah + + align:start position:0% +one yeah it's the function so the yeah + + + align:start position:0% +one yeah it's the function so the yeah +tell me again and I'll write it down G + + align:start position:0% +tell me again and I'll write it down G + + + align:start position:0% +tell me again and I'll write it down G +is zero g it's the it's a value of this + + align:start position:0% +is zero g it's the it's a value of this + + + align:start position:0% +is zero g it's the it's a value of this +function G we don't care what it is to + + align:start position:0% +function G we don't care what it is to + + + align:start position:0% +function G we don't care what it is to +the left and to the right at zero + + align:start position:0% +the left and to the right at zero + + + align:start position:0% +the left and to the right at zero +because it's really at zero that this + + align:start position:0% +because it's really at zero that this + + + align:start position:0% +because it's really at zero that this +thing turns on and that its value at + + align:start position:0% +thing turns on and that its value at + + + align:start position:0% +thing turns on and that its value at +that point is just uh gives us the + + align:start position:0% +that point is just uh gives us the + + + align:start position:0% +that point is just uh gives us the +amplitude of the impulse which is G of0 + + align:start position:0% +amplitude of the impulse which is G of0 + + + align:start position:0% +amplitude of the impulse which is G of0 +okay and of course if G is the constant + + align:start position:0% +okay and of course if G is the constant + + + align:start position:0% +okay and of course if G is the constant +function one I'm back to that formula + + align:start position:0% +function one I'm back to that formula + + + align:start position:0% +function one I'm back to that formula +but this is maybe the thing to watch for + + align:start position:0% +but this is maybe the thing to watch for + + + align:start position:0% +but this is maybe the thing to watch for +okay actually there's there's a lot + + align:start position:0% +okay actually there's there's a lot + + + align:start position:0% +okay actually there's there's a lot +built into that little thing we'll come + + align:start position:0% +built into that little thing we'll come + + + align:start position:0% +built into that little thing we'll come +back to that okay now so that's Delta + + align:start position:0% +back to that okay now so that's Delta + + + align:start position:0% +back to that okay now so that's Delta +functions uh integrated and now here are + + align:start position:0% +functions uh integrated and now here are + + + align:start position:0% +functions uh integrated and now here are +some pictures these are the good + + align:start position:0% +some pictures these are the good + + + align:start position:0% +some pictures these are the good +pictures + + align:start position:0% +pictures + + + align:start position:0% +pictures +okay so here is one integral of the + + align:start position:0% +okay so here is one integral of the + + + align:start position:0% +okay so here is one integral of the +delta + + align:start position:0% + + + + align:start position:0% + +function it's a step function okay and + + align:start position:0% +function it's a step function okay and + + + align:start position:0% +function it's a step function okay and +the step of course will occur at the + + align:start position:0% +the step of course will occur at the + + + align:start position:0% +the step of course will occur at the +point a if I the the integral of the + + align:start position:0% +point a if I the the integral of the + + + align:start position:0% +point a if I the the integral of the +Delta function at a point a will be the + + align:start position:0% +Delta function at a point a will be the + + + align:start position:0% +Delta function at a point a will be the +step + + align:start position:0% +step + + + align:start position:0% +step +function that where the action happens + + align:start position:0% +function that where the action happens + + + align:start position:0% +function that where the action happens +the jump happens I could call it a jump + + align:start position:0% +the jump happens I could call it a jump + + + align:start position:0% +the jump happens I could call it a jump +function at that point a because just + + align:start position:0% +function at that point a because just + + + align:start position:0% +function at that point a because just +for the reason we said that if we end + + align:start position:0% +for the reason we said that if we end + + + align:start position:0% +for the reason we said that if we end +integrate the integral is zero and then + + align:start position:0% +integrate the integral is zero and then + + + align:start position:0% +integrate the integral is zero and then +as soon as our integral passes this + + align:start position:0% +as soon as our integral passes this + + + align:start position:0% +as soon as our integral passes this +point so this is the integral of the + + align:start position:0% +point so this is the integral of the + + + align:start position:0% +point so this is the integral of the +this is I integrated it I I I + + align:start position:0% +this is I integrated it I I I + + + align:start position:0% +this is I integrated it I I I +integrate to get to this picture I start + + align:start position:0% +integrate to get to this picture I start + + + align:start position:0% +integrate to get to this picture I start +with that Delta function and I integrate + + align:start position:0% +with that Delta function and I integrate + + + align:start position:0% +with that Delta function and I integrate +and it suddenly jumps to one as soon as + + align:start position:0% +and it suddenly jumps to one as soon as + + + align:start position:0% +and it suddenly jumps to one as soon as +the integral goes past the spike the + + align:start position:0% +the integral goes past the spike the + + + align:start position:0% +the integral goes past the spike the +impulse okay so a step function very + + align:start position:0% +impulse okay so a step function very + + + align:start position:0% +impulse okay so a step function very +handy function step function + + align:start position:0% +handy function step function + + + align:start position:0% +handy function step function +sometimes called a heavys side function + + align:start position:0% +sometimes called a heavys side function + + + align:start position:0% +sometimes called a heavys side function +named after the guy who uh the + + align:start position:0% +named after the guy who uh the + + + align:start position:0% +named after the guy who uh the +electrical engineer I think who who + + align:start position:0% +electrical engineer I think who who + + + align:start position:0% +electrical engineer I think who who +started who first sort of worked out the + + align:start position:0% +started who first sort of worked out the + + + align:start position:0% +started who first sort of worked out the +rules for using these okay let's + + align:start position:0% +rules for using these okay let's + + + align:start position:0% +rules for using these okay let's +integrate one more time because we have + + align:start position:0% +integrate one more time because we have + + + align:start position:0% +integrate one more time because we have +second order equation second derivative + + align:start position:0% +second order equation second derivative + + + align:start position:0% +second order equation second derivative +so we better integrate twice to to to + + align:start position:0% +so we better integrate twice to to to + + + align:start position:0% +so we better integrate twice to to to +see what sort of answer we get Now + + align:start position:0% +see what sort of answer we get Now + + + align:start position:0% +see what sort of answer we get Now +integrate a step function so again the + + align:start position:0% +integrate a step function so again the + + + align:start position:0% +integrate a step function so again the +integral is zero all the way to the left + + align:start position:0% +integral is zero all the way to the left + + + align:start position:0% +integral is zero all the way to the left +so I'm still getting zero but now Beyond + + align:start position:0% +so I'm still getting zero but now Beyond + + + align:start position:0% +so I'm still getting zero but now Beyond +this point I'm integrating one and the + + align:start position:0% +this point I'm integrating one and the + + + align:start position:0% +this point I'm integrating one and the +integral of one is + + align:start position:0% +integral of one is + + + align:start position:0% +integral of one is +X so now that I would call a ramp + + align:start position:0% +X so now that I would call a ramp + + + align:start position:0% +X so now that I would call a ramp +function that's that's a nice short word + + align:start position:0% +function that's that's a nice short word + + + align:start position:0% +function that's that's a nice short word +for for this valuable function the ramp + + align:start position:0% +for for this valuable function the ramp + + + align:start position:0% +for for this valuable function the ramp +function is the function that's zero and + + align:start position:0% +function is the function that's zero and + + + align:start position:0% +function is the function that's zero and +then X so what oh now so what derivative + + align:start position:0% +then X so what oh now so what derivative + + + align:start position:0% +then X so what oh now so what derivative +of the tell me about about that ramp + + align:start position:0% +of the tell me about about that ramp + + + align:start position:0% +of the tell me about about that ramp +function just think + + align:start position:0% +function just think + + + align:start position:0% +function just think +about what happens to its derivative at + + align:start position:0% +about what happens to its derivative at + + + align:start position:0% +about what happens to its derivative at +the point a as I run along and I hit + + align:start position:0% +the point a as I run along and I hit + + + align:start position:0% +the point a as I run along and I hit +this key Point what happens to the + + align:start position:0% +this key Point what happens to the + + + align:start position:0% +this key Point what happens to the +derivative of the + + align:start position:0% +derivative of the + + + align:start position:0% +derivative of the +ramp + + align:start position:0% +ramp + + + align:start position:0% +ramp +it is does the what does the derivative + + align:start position:0% +it is does the what does the derivative + + + align:start position:0% +it is does the what does the derivative +do I'm look focus on that ramp now what + + align:start position:0% +do I'm look focus on that ramp now what + + + align:start position:0% +do I'm look focus on that ramp now what +does the derivative do at that + + align:start position:0% +does the derivative do at that + + + align:start position:0% +does the derivative do at that +point it jumps the derivative jumps the + + align:start position:0% +point it jumps the derivative jumps the + + + align:start position:0% +point it jumps the derivative jumps the +slope is the derivative the slope jumps + + align:start position:0% +slope is the derivative the slope jumps + + + align:start position:0% +slope is the derivative the slope jumps +from zero and here the slope is one and + + align:start position:0% +from zero and here the slope is one and + + + align:start position:0% +from zero and here the slope is one and +of course that's what that's telling us + + align:start position:0% +of course that's what that's telling us + + + align:start position:0% +of course that's what that's telling us +here's the picture of the derivative + + align:start position:0% +here's the picture of the derivative + + + align:start position:0% +here's the picture of the derivative +what does the second derivative + + align:start position:0% +what does the second derivative + + + align:start position:0% +what does the second derivative +do well since I integrate twice I + + align:start position:0% +do well since I integrate twice I + + + align:start position:0% +do well since I integrate twice I +guess going back two steps I'll find out + + align:start position:0% +guess going back two steps I'll find out + + + align:start position:0% +guess going back two steps I'll find out +what the second derivative is so the + + align:start position:0% +what the second derivative is so the + + + align:start position:0% +what the second derivative is so the +first derivative go it takes a + + align:start position:0% +first derivative go it takes a + + + align:start position:0% +first derivative go it takes a +jump the second derivative is the + + align:start position:0% +jump the second derivative is the + + + align:start position:0% +jump the second derivative is the +derivative of that jump + + align:start position:0% +derivative of that jump + + + align:start position:0% +derivative of that jump +so it's got the impulse so the second + + align:start position:0% +so it's got the impulse so the second + + + align:start position:0% +so it's got the impulse so the second +derivative this is straight line here + + align:start position:0% +derivative this is straight line here + + + align:start position:0% +derivative this is straight line here +second derivative straight line This is + + align:start position:0% +second derivative straight line This is + + + align:start position:0% +second derivative straight line This is +straight line here second derivative of + + align:start position:0% +straight line here second derivative of + + + align:start position:0% +straight line here second derivative of +a straight line is a straight line but + + align:start position:0% +a straight line is a straight line but + + + align:start position:0% +a straight line is a straight line but +at the at that point the first + + align:start position:0% +at the at that point the first + + + align:start position:0% +at the at that point the first +derivative jumps the second derivative + + align:start position:0% +derivative jumps the second derivative + + + align:start position:0% +derivative jumps the second derivative +has that Delta function in other words + + align:start position:0% +has that Delta function in other words + + + align:start position:0% +has that Delta function in other words +that's that that's the okay if I keep + + align:start position:0% +that's that that's the okay if I keep + + + align:start position:0% +that's that that's the okay if I keep +integrating and I don't need higher + + align:start position:0% +integrating and I don't need higher + + + align:start position:0% +integrating and I don't need higher +integrals in this in today lecture uh + + align:start position:0% +integrals in this in today lecture uh + + + align:start position:0% +integrals in this in today lecture uh +another integral would be what if I + + align:start position:0% +another integral would be what if I + + + align:start position:0% +another integral would be what if I +integrate this function then it's + + align:start position:0% +integrate this function then it's + + + align:start position:0% +integrate this function then it's +running along to zero what's the + + align:start position:0% +running along to zero what's the + + + align:start position:0% +running along to zero what's the +integral of this uh doesn't quite turn + + align:start position:0% +integral of this uh doesn't quite turn + + + align:start position:0% +integral of this uh doesn't quite turn +that steeply um what's that curve + + align:start position:0% +that steeply um what's that curve + + + align:start position:0% +that steeply um what's that curve +there if i' if I've integrated the ramp + + align:start position:0% +there if i' if I've integrated the ramp + + + align:start position:0% +there if i' if I've integrated the ramp +here's the integral first The Next Step + + align:start position:0% +here's the integral first The Next Step + + + align:start position:0% +here's the integral first The Next Step +Up the integral of the ramp would + + align:start position:0% +Up the integral of the ramp would + + + align:start position:0% +Up the integral of the ramp would +be it'll be x s yeah it'll be a parabola + + align:start position:0% +be it'll be x s yeah it'll be a parabola + + + align:start position:0% +be it'll be x s yeah it'll be a parabola +X2 over two the integral of that and now + + align:start position:0% +X2 over two the integral of that and now + + + align:start position:0% +X2 over two the integral of that and now +what do I get when I integrate this one + + align:start position:0% +what do I get when I integrate this one + + + align:start position:0% +what do I get when I integrate this one +I get something very important not + + align:start position:0% +I get something very important not + + + align:start position:0% +I get something very important not +important today but important in a few + + align:start position:0% +important today but important in a few + + + align:start position:0% +important today but important in a few +weeks it's it's and very useful in + + align:start position:0% +weeks it's it's and very useful in + + + align:start position:0% +weeks it's it's and very useful in +Computing these have turned out to be uh + + align:start position:0% +Computing these have turned out to be uh + + + align:start position:0% +Computing these have turned out to be uh +just the right thing so again now I'm + + align:start position:0% +just the right thing so again now I'm + + + align:start position:0% +just the right thing so again now I'm +integrating that everybody can tell me + + align:start position:0% +integrating that everybody can tell me + + + align:start position:0% +integrating that everybody can tell me +what is that what's that curve + + align:start position:0% +what is that what's that curve + + + align:start position:0% +what is that what's that curve +now it's the next integral of course the + + align:start position:0% +now it's the next integral of course the + + + align:start position:0% +now it's the next integral of course the +area under that will be X Cub over + + align:start position:0% +area under that will be X Cub over + + + align:start position:0% +area under that will be X Cub over +6 okay so now that is a function yeah + + align:start position:0% +6 okay so now that is a function yeah + + + align:start position:0% +6 okay so now that is a function yeah +it's worth maybe just for practice + + align:start position:0% +it's worth maybe just for practice + + + align:start position:0% +it's worth maybe just for practice +what's the deal with that + + align:start position:0% +what's the deal with that + + + align:start position:0% +what's the deal with that +function that's pretty smooth + + align:start position:0% +function that's pretty smooth + + + align:start position:0% +function that's pretty smooth +function because it certainly passes + + align:start position:0% +function because it certainly passes + + + align:start position:0% +function because it certainly passes +right it it meets at that point the + + align:start position:0% +right it it meets at that point the + + + align:start position:0% +right it it meets at that point the +first derivative meets at that point the + + align:start position:0% +first derivative meets at that point the + + + align:start position:0% +first derivative meets at that point the +second derivative meets at that point + + align:start position:0% +second derivative meets at that point + + + align:start position:0% +second derivative meets at that point +the third derivative does what of this + + align:start position:0% +the third derivative does what of this + + + align:start position:0% +the third derivative does what of this +blind the third derivative take three + + align:start position:0% +blind the third derivative take three + + + align:start position:0% +blind the third derivative take three +steps back down the line and you see + + align:start position:0% +steps back down the line and you see + + + align:start position:0% +steps back down the line and you see +that the third derivative jumps right + + align:start position:0% +that the third derivative jumps right + + + align:start position:0% +that the third derivative jumps right +the third derivative of that is the + + align:start position:0% +the third derivative of that is the + + + align:start position:0% +the third derivative of that is the +third derivative would be shall I for c + + align:start position:0% +third derivative would be shall I for c + + + align:start position:0% +third derivative would be shall I for c +for cubic spline or something the third + + align:start position:0% +for cubic spline or something the third + + + align:start position:0% +for cubic spline or something the third +derivative will be zero there and the + + align:start position:0% +derivative will be zero there and the + + + align:start position:0% +derivative will be zero there and the +third derivative of that is exactly like + + align:start position:0% +third derivative of that is exactly like + + + align:start position:0% +third derivative of that is exactly like +back to that back to that back to one is + + align:start position:0% +back to that back to that back to one is + + + align:start position:0% +back to that back to that back to one is +one + + align:start position:0% +one + + + align:start position:0% +one +so the third derivative so the cubic + + align:start position:0% +so the third derivative so the cubic + + + align:start position:0% +so the third derivative so the cubic +blinds so smooth your eye doesn't see + + align:start position:0% +blinds so smooth your eye doesn't see + + + align:start position:0% +blinds so smooth your eye doesn't see +that that that that they're very useful + + align:start position:0% +that that that that they're very useful + + + align:start position:0% +that that that that they're very useful +for drawing many many purposes uh CAD + + align:start position:0% +for drawing many many purposes uh CAD + + + align:start position:0% +for drawing many many purposes uh CAD +programs would use such things + + align:start position:0% +programs would use such things + + + align:start position:0% +programs would use such things +constantly because they're they're + + align:start position:0% +constantly because they're they're + + + align:start position:0% +constantly because they're they're +convenient they're piece they have nice + + align:start position:0% +convenient they're piece they have nice + + + align:start position:0% +convenient they're piece they have nice +pieces that you can fit together and + + align:start position:0% +pieces that you can fit together and + + + align:start position:0% +pieces that you can fit together and +they fit together very smoothly uh but + + align:start position:0% +they fit together very smoothly uh but + + + align:start position:0% +they fit together very smoothly uh but +they really are two separate functions + + align:start position:0% +they really are two separate functions + + + align:start position:0% +they really are two separate functions +okay so that's up to cubic spine but we + + align:start position:0% +okay so that's up to cubic spine but we + + + align:start position:0% +okay so that's up to cubic spine but we +our focus is these would solve what + + align:start position:0% +our focus is these would solve what + + + align:start position:0% +our focus is these would solve what +equations would those + + align:start position:0% +equations would those + + + align:start position:0% +equations would those +solve well that takes how many + + align:start position:0% +solve well that takes how many + + + align:start position:0% +solve well that takes how many +derivatives to get to a Delta so what + + align:start position:0% +derivatives to get to a Delta so what + + + align:start position:0% +derivatives to get to a Delta so what +what would be the equation uh what would + + align:start position:0% +what would be the equation uh what would + + + align:start position:0% +what would be the equation uh what would +be the the what would be the right hand + + align:start position:0% +be the the what would be the right hand + + + align:start position:0% +be the the what would be the right hand +side yeah let me take the fourth + + align:start position:0% +side yeah let me take the fourth + + + align:start position:0% +side yeah let me take the fourth +derivative yeah I just ask the question + + align:start position:0% +derivative yeah I just ask the question + + + align:start position:0% +derivative yeah I just ask the question +that way what would be the fourth + + align:start position:0% +that way what would be the fourth + + + align:start position:0% +that way what would be the fourth +derivative of that cubic + + align:start position:0% +derivative of that cubic + + + align:start position:0% +derivative of that cubic +spine a Delta right four steps back so + + align:start position:0% +spine a Delta right four steps back so + + + align:start position:0% +spine a Delta right four steps back so +what is physically what what are we + + align:start position:0% +what is physically what what are we + + + align:start position:0% +what is physically what what are we +seeing + + align:start position:0% +seeing + + + align:start position:0% +seeing +here do you do you recognize what what + + align:start position:0% +here do you do you recognize what what + + + align:start position:0% +here do you do you recognize what what +kind in if I ask now people in mechanics + + align:start position:0% +kind in if I ask now people in mechanics + + + align:start position:0% +kind in if I ask now people in mechanics +when will we meet a fourth order + + align:start position:0% +when will we meet a fourth order + + + align:start position:0% +when will we meet a fourth order +equation fourth derivative equals a + + align:start position:0% +equation fourth derivative equals a + + + align:start position:0% +equation fourth derivative equals a +load anybody know the the the physical + + align:start position:0% +load anybody know the the the physical + + + align:start position:0% +load anybody know the the the physical +situation where fourth der + + align:start position:0% + + + + align:start position:0% + +where beams yeah it's the equation for a + + align:start position:0% +where beams yeah it's the equation for a + + + align:start position:0% +where beams yeah it's the equation for a +beam a beam uh has uh the bending of a + + align:start position:0% +beam a beam uh has uh the bending of a + + + align:start position:0% +beam a beam uh has uh the bending of a +beam so it's a beam this eraser isn't + + align:start position:0% +beam so it's a beam this eraser isn't + + + align:start position:0% +beam so it's a beam this eraser isn't +too very much like a beam but anyway I + + align:start position:0% +too very much like a beam but anyway I + + + align:start position:0% +too very much like a beam but anyway I +put the chalk on well nothing happened + + align:start position:0% +put the chalk on well nothing happened + + + align:start position:0% +put the chalk on well nothing happened +um sit on it whatever uh it'll Bend and + + align:start position:0% +um sit on it whatever uh it'll Bend and + + + align:start position:0% +um sit on it whatever uh it'll Bend and +that bending will be given by a beam + + align:start position:0% +that bending will be given by a beam + + + align:start position:0% +that bending will be given by a beam +equation okay so let will meet the beam + + align:start position:0% +equation okay so let will meet the beam + + + align:start position:0% +equation okay so let will meet the beam +equation so it's the most most equations + + align:start position:0% +equation so it's the most most equations + + + align:start position:0% +equation so it's the most most equations +of uh physics + + align:start position:0% +of uh physics + + + align:start position:0% +of uh physics +mechanics uh biology everything are + + align:start position:0% +mechanics uh biology everything are + + + align:start position:0% +mechanics uh biology everything are +second + + align:start position:0% +second + + + align:start position:0% +second +order Newton's law is often the reason + + align:start position:0% +order Newton's law is often the reason + + + align:start position:0% +order Newton's law is often the reason +but uh we get up to fourth order + + align:start position:0% +but uh we get up to fourth order + + + align:start position:0% +but uh we get up to fourth order +sometimes okay and very seldom get + + align:start position:0% +sometimes okay and very seldom get + + + align:start position:0% +sometimes okay and very seldom get +higher hopefully yeah beams or plates + + align:start position:0% +higher hopefully yeah beams or plates + + + align:start position:0% +higher hopefully yeah beams or plates +that table would that that table would + + align:start position:0% +that table would that that table would + + + align:start position:0% +that table would that that table would +be a plate and it would have a fourth + + align:start position:0% +be a plate and it would have a fourth + + + align:start position:0% +be a plate and it would have a fourth +order equation + + align:start position:0% + + + + align:start position:0% + +okay let let's start solving this + + align:start position:0% +okay let let's start solving this + + + align:start position:0% +okay let let's start solving this +problem what's the solution what's the + + align:start position:0% +problem what's the solution what's the + + + align:start position:0% +problem what's the solution what's the +general solution to that equation minus + + align:start position:0% +general solution to that equation minus + + + align:start position:0% +general solution to that equation minus +the second derivative so notice the + + align:start position:0% +the second derivative so notice the + + + align:start position:0% +the second derivative so notice the +minus that I like and the load is now + + align:start position:0% +minus that I like and the load is now + + + align:start position:0% +minus that I like and the load is now +moved to the point a so the solution U + + align:start position:0% +moved to the point a so the solution U + + + align:start position:0% +moved to the point a so the solution U +of X let let's let's write down all + + align:start position:0% +of X let let's let's write down all + + + align:start position:0% +of X let let's let's write down all +solutions well tell me one solution + + align:start position:0% +solutions well tell me one solution + + + align:start position:0% +solutions well tell me one solution +first one particular solution what is + + align:start position:0% +first one particular solution what is + + + align:start position:0% +first one particular solution what is +one function for which minus the second + + align:start position:0% +one function for which minus the second + + + align:start position:0% +one function for which minus the second +derivative would be the + + align:start position:0% +derivative would be the + + + align:start position:0% +derivative would be the +Delta that's what we got over there so + + align:start position:0% +Delta that's what we got over there so + + + align:start position:0% +Delta that's what we got over there so +just bring that Blackboard over + + align:start position:0% +just bring that Blackboard over + + + align:start position:0% +just bring that Blackboard over +here change its sign because that minus + + align:start position:0% +here change its sign because that minus + + + align:start position:0% +here change its sign because that minus +and what are you going to tell me + + align:start position:0% +and what are you going to tell me + + + align:start position:0% +and what are you going to tell me +minus + + align:start position:0% +minus + + + align:start position:0% +minus +a ramp minus a ramp and the ramp of + + align:start position:0% +a ramp minus a ramp and the ramp of + + + align:start position:0% +a ramp minus a ramp and the ramp of +course will ramp up at the point a in + + align:start position:0% +course will ramp up at the point a in + + + align:start position:0% +course will ramp up at the point a in +order to match where the so that it's + + align:start position:0% +order to match where the so that it's + + + align:start position:0% +order to match where the so that it's +second the second derivative of that the + + align:start position:0% +second the second derivative of that the + + + align:start position:0% +second the second derivative of that the +second derivative of R will be Delta the + + align:start position:0% +second derivative of R will be Delta the + + + align:start position:0% +second derivative of R will be Delta the +minus is correct and the point is + + align:start position:0% +minus is correct and the point is + + + align:start position:0% +minus is correct and the point is +correct okay now does that solve our + + align:start position:0% + + + + align:start position:0% + +problem + + align:start position:0% +problem + + + align:start position:0% +problem +no no the ramp is going upwards it's not + + align:start position:0% +no no the ramp is going upwards it's not + + + align:start position:0% +no no the ramp is going upwards it's not +zero what am I + + align:start position:0% +zero what am I + + + align:start position:0% +zero what am I +forgetting what do I not yet have + + align:start position:0% +forgetting what do I not yet have + + + align:start position:0% +forgetting what do I not yet have +there's more to be more to this solution + + align:start position:0% +there's more to be more to this solution + + + align:start position:0% +there's more to be more to this solution +just as there was for a uniform load + + align:start position:0% +just as there was for a uniform load + + + align:start position:0% +just as there was for a uniform load +what what was the + + align:start position:0% +what what was the + + + align:start position:0% +what what was the +more constant + + align:start position:0% +more constant + + + align:start position:0% +more constant +and and I I want two two + + align:start position:0% +and and I I want two two + + + align:start position:0% +and and I I want two two +uh homogeneous Solutions null Solutions + + align:start position:0% +uh homogeneous Solutions null Solutions + + + align:start position:0% +uh homogeneous Solutions null Solutions +two solutions with derivative equ second + + align:start position:0% +two solutions with derivative equ second + + + align:start position:0% +two solutions with derivative equ second +derivative equals zero one of them is C + + align:start position:0% +derivative equals zero one of them is C + + + align:start position:0% +derivative equals zero one of them is C +and the other one is DX thanks okay + + align:start position:0% +and the other one is DX thanks okay + + + align:start position:0% +and the other one is DX thanks okay +that's the whole solution okay okay so + + align:start position:0% +that's the whole solution okay okay so + + + align:start position:0% +that's the whole solution okay okay so +what I want to I mean my we need that C+ + + align:start position:0% +what I want to I mean my we need that C+ + + + align:start position:0% +what I want to I mean my we need that C+ +DX we got two boundary conditions to + + align:start position:0% +DX we got two boundary conditions to + + + align:start position:0% +DX we got two boundary conditions to +satisfy just as before so I need two + + align:start position:0% +satisfy just as before so I need two + + + align:start position:0% +satisfy just as before so I need two +constants that'll do it perfectly and + + align:start position:0% +constants that'll do it perfectly and + + + align:start position:0% +constants that'll do it perfectly and +I'll get an exact answer okay and it it + + align:start position:0% +I'll get an exact answer okay and it it + + + align:start position:0% +I'll get an exact answer okay and it it +it well so this is a ramp + + align:start position:0% +it well so this is a ramp + + + align:start position:0% +it well so this is a ramp +what oh yeah before I go further let me + + align:start position:0% +what oh yeah before I go further let me + + + align:start position:0% +what oh yeah before I go further let me +just let's let's just how what I think + + align:start position:0% +just let's let's just how what I think + + + align:start position:0% +just let's let's just how what I think +about this this is a ramp that that + + align:start position:0% +about this this is a ramp that that + + + align:start position:0% +about this this is a ramp that that +turns which way down right this is a + + align:start position:0% +turns which way down right this is a + + + align:start position:0% +turns which way down right this is a +with that minus sign that ramp turns + + align:start position:0% +with that minus sign that ramp turns + + + align:start position:0% +with that minus sign that ramp turns +down at the point x equal a right it and + + align:start position:0% +down at the point x equal a right it and + + + align:start position:0% +down at the point x equal a right it and +it's its derivative goes from 0 to minus + + align:start position:0% +it's its derivative goes from 0 to minus + + + align:start position:0% +it's its derivative goes from 0 to minus +one the the derivative the slope of this + + align:start position:0% +one the the derivative the slope of this + + + align:start position:0% +one the the derivative the slope of this +guy drops by one because of the minus + + align:start position:0% +guy drops by one because of the minus + + + align:start position:0% +guy drops by one because of the minus +sign of sorry the slope yeah the slope + + align:start position:0% +sign of sorry the slope yeah the slope + + + align:start position:0% +sign of sorry the slope yeah the slope +of the of + + align:start position:0% +of the of + + + align:start position:0% +of the of +the sorry the slope of the yeah the + + align:start position:0% +the sorry the slope of the yeah the + + + align:start position:0% +the sorry the slope of the yeah the +slope of the ramp function of minus the + + align:start position:0% +slope of the ramp function of minus the + + + align:start position:0% +slope of the ramp function of minus the +ramp it goes at zero drops by one and + + align:start position:0% +ramp it goes at zero drops by one and + + + align:start position:0% +ramp it goes at zero drops by one and +and what this is going to do is take + + align:start position:0% +and what this is going to do is take + + + align:start position:0% +and what this is going to do is take +that ramp and adjust + + align:start position:0% +that ramp and adjust + + + align:start position:0% +that ramp and adjust +it to the to go through the fixed ends + + align:start position:0% +it to the to go through the fixed ends + + + align:start position:0% +it to the to go through the fixed ends +so let's just do it let's just do it + + align:start position:0% +so let's just do it let's just do it + + + align:start position:0% +so let's just do it let's just do it +what are C and D what are C and D my + + align:start position:0% +what are C and D what are C and D my + + + align:start position:0% +what are C and D what are C and D my +point a let let me draw a graph that's + + align:start position:0% +point a let let me draw a graph that's + + + align:start position:0% +point a let let me draw a graph that's +always the best thing always draw a + + align:start position:0% +always the best thing always draw a + + + align:start position:0% +always the best thing always draw a +graph of your of these Solutions + + align:start position:0% +graph of your of these Solutions + + + align:start position:0% +graph of your of these Solutions +okay so let me put in the point a okay + + align:start position:0% +okay so let me put in the point a okay + + + align:start position:0% +okay so let me put in the point a okay +so I'm drawing now a picture of the + + align:start position:0% +so I'm drawing now a picture of the + + + align:start position:0% +so I'm drawing now a picture of the +solution from zero to one I'll graph it + + align:start position:0% +solution from zero to one I'll graph it + + + align:start position:0% +solution from zero to one I'll graph it +it's + + align:start position:0% +it's + + + align:start position:0% +it's +got okay what what what do I have here + + align:start position:0% +got okay what what what do I have here + + + align:start position:0% +got okay what what what do I have here +well let should we just plug in plug in + + align:start position:0% +well let should we just plug in plug in + + + align:start position:0% +well let should we just plug in plug in +uh the boundary conditions and find c + + align:start position:0% +uh the boundary conditions and find c + + + align:start position:0% +uh the boundary conditions and find c +and d That's the direct way what is + + align:start position:0% +and d That's the direct way what is + + + align:start position:0% +and d That's the direct way what is +C see I'm going to plug in hopefully I + + align:start position:0% +C see I'm going to plug in hopefully I + + + align:start position:0% +C see I'm going to plug in hopefully I +might find it from just the first + + align:start position:0% +might find it from just the first + + + align:start position:0% +might find it from just the first +boundary condition if I if I'm starting + + align:start position:0% +boundary condition if I if I'm starting + + + align:start position:0% +boundary condition if I if I'm starting +from zero well this guy certainly starts + + align:start position:0% +from zero well this guy certainly starts + + + align:start position:0% +from zero well this guy certainly starts +at zero right it it the ramp hasn't done + + align:start position:0% +at zero right it it the ramp hasn't done + + + align:start position:0% +at zero right it it the ramp hasn't done +anything until it gets to a and this guy + + align:start position:0% +anything until it gets to a and this guy + + + align:start position:0% +anything until it gets to a and this guy +is certainly zero so what is C gone + + align:start position:0% +is certainly zero so what is C gone + + + align:start position:0% +is certainly zero so what is C gone +right okay good now what is + + align:start position:0% +right okay good now what is + + + align:start position:0% +right okay good now what is +D okay well all right what's + + align:start position:0% +D okay well all right what's + + + align:start position:0% +D okay well all right what's +d uh let's see let me draw the + + align:start position:0% +d uh let's see let me draw the + + + align:start position:0% +d uh let's see let me draw the +so there's a there's a DX and D D won't + + align:start position:0% +so there's a there's a DX and D D won't + + + align:start position:0% +so there's a there's a DX and D D won't +be zero I want that thing to be one to + + align:start position:0% +be zero I want that thing to be one to + + + align:start position:0% +be zero I want that thing to be one to +be zero at 0.1 so I I want to determine + + align:start position:0% +be zero at 0.1 so I I want to determine + + + align:start position:0% +be zero at 0.1 so I I want to determine +D okay let me let me determine D so what + + align:start position:0% +D okay let me let me determine D so what + + + align:start position:0% +D okay let me let me determine D so what +is the minus the ramp at x equal 1 I'm + + align:start position:0% +is the minus the ramp at x equal 1 I'm + + + align:start position:0% +is the minus the ramp at x equal 1 I'm +plugging in x equal 1 is that right I'm + + align:start position:0% +plugging in x equal 1 is that right I'm + + + align:start position:0% +plugging in x equal 1 is that right I'm +going straight forward here plugging in + + align:start position:0% +going straight forward here plugging in + + + align:start position:0% +going straight forward here plugging in +x equal one into this boundary condition + + align:start position:0% +x equal one into this boundary condition + + + align:start position:0% +x equal one into this boundary condition +ready for this guy okay what's the ramp + + align:start position:0% +ready for this guy okay what's the ramp + + + align:start position:0% +ready for this guy okay what's the ramp +so it's minus and the ramp + + align:start position:0% +so it's minus and the ramp + + + align:start position:0% +so it's minus and the ramp +is well if this ramp is if if a ramp is + + align:start position:0% +is well if this ramp is if if a ramp is + + + align:start position:0% +is well if this ramp is if if a ramp is +shifted over then that shifted over so + + align:start position:0% +shifted over then that shifted over so + + + align:start position:0% +shifted over then that shifted over so +at x equal to one what's the ramp how + + align:start position:0% +at x equal to one what's the ramp how + + + align:start position:0% +at x equal to one what's the ramp how +how high has that ramp gone one minus a + + align:start position:0% +how high has that ramp gone one minus a + + + align:start position:0% +how high has that ramp gone one minus a +right the ramp is xus a at that point x + + align:start position:0% +right the ramp is xus a at that point x + + + align:start position:0% +right the ramp is xus a at that point x +at at the point x = 1 it will be 1 - A + + align:start position:0% +at at the point x = 1 it will be 1 - A + + + align:start position:0% +at at the point x = 1 it will be 1 - A +so I think I get 1 - 1 - A + + align:start position:0% +so I think I get 1 - 1 - A + + + align:start position:0% +so I think I get 1 - 1 - A +minus the ramp plus d * + + align:start position:0% +minus the ramp plus d * + + + align:start position:0% +minus the ramp plus d * +what one I'm plugging in xal 1 and + + align:start position:0% +what one I'm plugging in xal 1 and + + + align:start position:0% +what one I'm plugging in xal 1 and +that's supposed to + + align:start position:0% +that's supposed to + + + align:start position:0% +that's supposed to +equal zero + + align:start position:0% +equal zero + + + align:start position:0% +equal zero +good so I'm doing I'm doing this the + + align:start position:0% +good so I'm doing I'm doing this the + + + align:start position:0% +good so I'm doing I'm doing this the +sort of the systematic way of writing + + align:start position:0% +sort of the systematic way of writing + + + align:start position:0% +sort of the systematic way of writing +down the general solution discovering + + align:start position:0% +down the general solution discovering + + + align:start position:0% +down the general solution discovering +that D what do I discover D is put it on + + align:start position:0% +that D what do I discover D is put it on + + + align:start position:0% +that D what do I discover D is put it on +the other side D is 1 - A and of course + + align:start position:0% +the other side D is 1 - A and of course + + + align:start position:0% +the other side D is 1 - A and of course +don't forget that it's multiplying the X + + align:start position:0% +don't forget that it's multiplying the X + + + align:start position:0% +don't forget that it's multiplying the X +so + + align:start position:0% + + + + align:start position:0% + +okay all right let me just draw the + + align:start position:0% +okay all right let me just draw the + + + align:start position:0% +okay all right let me just draw the +picture it's uh yeah here's how I think + + align:start position:0% +picture it's uh yeah here's how I think + + + align:start position:0% +picture it's uh yeah here's how I think +about + + align:start position:0% +about + + + align:start position:0% +about +it the solution is away from x equal a + + align:start position:0% +it the solution is away from x equal a + + + align:start position:0% +it the solution is away from x equal a +what does the solution look + + align:start position:0% +what does the solution look + + + align:start position:0% +what does the solution look +like to the left of x equal a What's My + + align:start position:0% +like to the left of x equal a What's My + + + align:start position:0% +like to the left of x equal a What's My +Graph going to be it's going to be + + align:start position:0% + + + + align:start position:0% + +be a straight line right to the left of + + align:start position:0% +be a straight line right to the left of + + + align:start position:0% +be a straight line right to the left of +here there is no + + align:start position:0% +here there is no + + + align:start position:0% +here there is no +load the the equation is second + + align:start position:0% +load the the equation is second + + + align:start position:0% +load the the equation is second +derivative + + align:start position:0% +derivative + + + align:start position:0% +derivative +equals zero the solution to that is the + + align:start position:0% +equals zero the solution to that is the + + + align:start position:0% +equals zero the solution to that is the +straight line in other words until I get + + align:start position:0% +straight line in other words until I get + + + align:start position:0% +straight line in other words until I get +to a this thing hasn't started it's only + + align:start position:0% +to a this thing hasn't started it's only + + + align:start position:0% +to a this thing hasn't started it's only +this straight line it the solution does + + align:start position:0% +this straight line it the solution does + + + align:start position:0% +this straight line it the solution does +something like that it's a straight line + + align:start position:0% +something like that it's a straight line + + + align:start position:0% +something like that it's a straight line +and I guess actually that's what it is + + align:start position:0% +and I guess actually that's what it is + + + align:start position:0% +and I guess actually that's what it is +because the C isn't here and that's all + + align:start position:0% +because the C isn't here and that's all + + + align:start position:0% +because the C isn't here and that's all +we've got left so that's that's that + + align:start position:0% +we've got left so that's that's that + + + align:start position:0% +we've got left so that's that's that +straight + + align:start position:0% +straight + + + align:start position:0% +straight +line what happens what is it for the + + align:start position:0% +line what happens what is it for the + + + align:start position:0% +line what happens what is it for the +second half tell me what the solution + + align:start position:0% +second half tell me what the solution + + + align:start position:0% +second half tell me what the solution +looks like in the second half in between + + align:start position:0% +looks like in the second half in between + + + align:start position:0% +looks like in the second half in between +a and + + align:start position:0% +a and + + + align:start position:0% +a and +one it's going downhill + + align:start position:0% +one it's going downhill + + + align:start position:0% +one it's going downhill +why because it got to get back to + + align:start position:0% +why because it got to get back to + + + align:start position:0% +why because it got to get back to +zero and it's how is it going + + align:start position:0% +zero and it's how is it going + + + align:start position:0% +zero and it's how is it going +downhills it has to be + + align:start position:0% +downhills it has to be + + + align:start position:0% +downhills it has to be +linear in this region has to be linear + + align:start position:0% +linear in this region has to be linear + + + align:start position:0% +linear in this region has to be linear +why how do I know it's linear here + + align:start position:0% +why how do I know it's linear here + + + align:start position:0% +why how do I know it's linear here +because one way is to say the equation + + align:start position:0% +because one way is to say the equation + + + align:start position:0% +because one way is to say the equation +in that region is second derivative + + align:start position:0% +in that region is second derivative + + + align:start position:0% +in that region is second derivative +equals z second derivative equals z + + align:start position:0% +equals z second derivative equals z + + + align:start position:0% +equals z second derivative equals z +straight line This is my solution it's 1 + + align:start position:0% +straight line This is my solution it's 1 + + + align:start position:0% +straight line This is my solution it's 1 +- ax here and it's whatever it is to get + + align:start position:0% +- ax here and it's whatever it is to get + + + align:start position:0% +- ax here and it's whatever it is to get +back to + + align:start position:0% +back to + + + align:start position:0% +back to +zero what what what what will it take to + + align:start position:0% +zero what what what what will it take to + + + align:start position:0% +zero what what what what will it take to +get back to + + align:start position:0% +get back to + + + align:start position:0% +get back to +zero let's see well we could plug in + + align:start position:0% +zero let's see well we could plug in + + + align:start position:0% +zero let's see well we could plug in +we've got one expression here or I could + + align:start position:0% +we've got one expression here or I could + + + align:start position:0% +we've got one expression here or I could +just look at that I could say okay + + align:start position:0% +just look at that I could say okay + + + align:start position:0% +just look at that I could say okay +what's the equation for the straight + + align:start position:0% +what's the equation for the straight + + + align:start position:0% +what's the equation for the straight +line that's at at this point what is the + + align:start position:0% +line that's at at this point what is the + + + align:start position:0% +line that's at at this point what is the +yeah it's 1 - + + align:start position:0% + + + + align:start position:0% + +ax + + align:start position:0% +ax + + + align:start position:0% +ax +H I want it to be + + align:start position:0% +H I want it to be + + + align:start position:0% +H I want it to be +linear I want it to + + align:start position:0% +linear I want it to + + + align:start position:0% +linear I want it to +get to + + align:start position:0% +get to + + + align:start position:0% +get to +zero let's see if I if I want that it + + align:start position:0% +zero let's see if I if I want that it + + + align:start position:0% +zero let's see if I if I want that it +would be great to have 1 - x * something + + align:start position:0% +would be great to have 1 - x * something + + + align:start position:0% +would be great to have 1 - x * something +I have to figure out + + align:start position:0% +I have to figure out + + + align:start position:0% +I have to figure out +what because with the one minus X at xal + + align:start position:0% +what because with the one minus X at xal + + + align:start position:0% +what because with the one minus X at xal +one that'll drop off that's linear what + + align:start position:0% +one that'll drop off that's linear what + + + align:start position:0% +one that'll drop off that's linear what +number what's the key here that that + + align:start position:0% +number what's the key here that that + + + align:start position:0% +number what's the key here that that +that that + + align:start position:0% +that that + + + align:start position:0% +that that +slope I want to match them up + + align:start position:0% + + + + align:start position:0% + +there think at at and that's the point x + + align:start position:0% +there think at at and that's the point x + + + align:start position:0% +there think at at and that's the point x +equal + + align:start position:0% +equal + + + align:start position:0% +equal +a this is supposed to match that at x + + align:start position:0% +a this is supposed to match that at x + + + align:start position:0% +a this is supposed to match that at x +equal a do you have an idea for what I + + align:start position:0% +equal a do you have an idea for what I + + + align:start position:0% +equal a do you have an idea for what I +should + + align:start position:0% +should + + + align:start position:0% +should +take what what what what do I put right + + align:start position:0% +take what what what what do I put right + + + align:start position:0% +take what what what what do I put right +there + + align:start position:0% +there + + + align:start position:0% +there +a + + align:start position:0% +a + + + align:start position:0% +a +a look at the Symmetry in those two + + align:start position:0% +a look at the Symmetry in those two + + + align:start position:0% +a look at the Symmetry in those two +sides 1 - A * X going up 1 - x * a going + + align:start position:0% +sides 1 - A * X going up 1 - x * a going + + + align:start position:0% +sides 1 - A * X going up 1 - x * a going +down at x equal a it hits that point + + align:start position:0% +down at x equal a it hits that point + + + align:start position:0% +down at x equal a it hits that point +right that so we've solved it we could + + align:start position:0% +right that so we've solved it we could + + + align:start position:0% +right that so we've solved it we could +think about this different ways I could + + align:start position:0% +think about this different ways I could + + + align:start position:0% +think about this different ways I could +have got that one - x + + align:start position:0% +have got that one - x + + + align:start position:0% +have got that one - x +uh let's see I could have got it from + + align:start position:0% +uh let's see I could have got it from + + + align:start position:0% +uh let's see I could have got it from +the + + align:start position:0% +the + + + align:start position:0% +the +formula in a way I like to get it from + + align:start position:0% +formula in a way I like to get it from + + + align:start position:0% +formula in a way I like to get it from +the picture I see it sort of I see the + + align:start position:0% +the picture I see it sort of I see the + + + align:start position:0% +the picture I see it sort of I see the +point what what happened at that point + + align:start position:0% +point what what happened at that point + + + align:start position:0% +point what what happened at that point +what what are the jump conditions this + + align:start position:0% +what what are the jump conditions this + + + align:start position:0% +what what are the jump conditions this +is another way to ask the see how the + + align:start position:0% +is another way to ask the see how the + + + align:start position:0% +is another way to ask the see how the +Delta function works what are the jump + + align:start position:0% +Delta function works what are the jump + + + align:start position:0% +Delta function works what are the jump +conditions I want to know when I ask + + align:start position:0% +conditions I want to know when I ask + + + align:start position:0% +conditions I want to know when I ask +about jump conditions I want to know + + align:start position:0% +about jump conditions I want to know + + + align:start position:0% +about jump conditions I want to know +what are the conditions on U of X the + + align:start position:0% +what are the conditions on U of X the + + + align:start position:0% +what are the conditions on U of X the +displacement what are the conditions on + + align:start position:0% +displacement what are the conditions on + + + align:start position:0% +displacement what are the conditions on +the slope U Prime of X that would be + + align:start position:0% +the slope U Prime of X that would be + + + align:start position:0% +the slope U Prime of X that would be +that'll be the strain when we're + + align:start position:0% +that'll be the strain when we're + + + align:start position:0% +that'll be the strain when we're +speaking about + + align:start position:0% +speaking about + + + align:start position:0% +speaking about +elasticity uh what's just for U of X + + align:start position:0% +elasticity uh what's just for U of X + + + align:start position:0% +elasticity uh what's just for U of X +what are what what's the statement about + + align:start position:0% +what are what what's the statement about + + + align:start position:0% +what are what what's the statement about +U of x from the left and from the right + + align:start position:0% +U of x from the left and from the right + + + align:start position:0% +U of x from the left and from the right +at that at that point of + + align:start position:0% +at that at that point of + + + align:start position:0% +at that at that point of +at that c critical point the point of + + align:start position:0% +at that c critical point the point of + + + align:start position:0% +at that c critical point the point of +the load from the left and from the + + align:start position:0% +the load from the left and from the + + + align:start position:0% +the load from the left and from the +right U of X + + align:start position:0% +right U of X + + + align:start position:0% +right U of X +is the same U of X matches up U of x + + align:start position:0% +is the same U of X matches up U of x + + + align:start position:0% +is the same U of X matches up U of x +from the left is that height U of x from + + align:start position:0% +from the left is that height U of x from + + + align:start position:0% +from the left is that height U of x from +the right is that I I want to write down + + align:start position:0% +the right is that I I want to write down + + + align:start position:0% +the right is that I I want to write down +those jump + + align:start position:0% +those jump + + + align:start position:0% +those jump +conditions because that's another way to + + align:start position:0% +conditions because that's another way to + + + align:start position:0% +conditions because that's another way to +see this U of X youu at + + align:start position:0% +see this U of X youu at + + + align:start position:0% +see this U of X youu at +a from + + align:start position:0% +a from + + + align:start position:0% +a from +the left + + align:start position:0% +the left + + + align:start position:0% +the left +should equal + + align:start position:0% +should equal + + + align:start position:0% +should equal +U how do you want me to just say U is + + align:start position:0% +U how do you want me to just say U is + + + align:start position:0% +U how do you want me to just say U is +continuous yeah I'll just say it in + + align:start position:0% +continuous yeah I'll just say it in + + + align:start position:0% +continuous yeah I'll just say it in +words U is U of X is + + align:start position:0% +words U is U of X is + + + align:start position:0% +words U is U of X is +continuous at that just means it doesn't + + align:start position:0% +continuous at that just means it doesn't + + + align:start position:0% +continuous at that just means it doesn't +jump at x equal + + align:start position:0% +jump at x equal + + + align:start position:0% +jump at x equal +a so that's you could say that's a non- + + align:start position:0% +a so that's you could say that's a non- + + + align:start position:0% +a so that's you could say that's a non- +jump condition the function itself + + align:start position:0% +jump condition the function itself + + + align:start position:0% +jump condition the function itself +doesn't jump why not because we're + + align:start position:0% +doesn't jump why not because we're + + + align:start position:0% +doesn't jump why not because we're +talking about some elastic bar on which + + align:start position:0% +talking about some elastic bar on which + + + align:start position:0% +talking about some elastic bar on which +we put a point load the thing isn't + + align:start position:0% +we put a point load the thing isn't + + + align:start position:0% +we put a point load the thing isn't +going to + + align:start position:0% +going to + + + align:start position:0% +going to +break the bar is going the displacement + + align:start position:0% +break the bar is going the displacement + + + align:start position:0% +break the bar is going the displacement +is going to be continuous but what's the + + align:start position:0% +is going to be continuous but what's the + + + align:start position:0% +is going to be continuous but what's the +condition on U Prime of X the the + + align:start position:0% +condition on U Prime of X the the + + + align:start position:0% +condition on U Prime of X the the +derivative the slope so that's the + + align:start position:0% +derivative the slope so that's the + + + align:start position:0% +derivative the slope so that's the +function and now tell me what's the deal + + align:start position:0% +function and now tell me what's the deal + + + align:start position:0% +function and now tell me what's the deal +on the slope what's the comparison + + align:start position:0% +on the slope what's the comparison + + + align:start position:0% +on the slope what's the comparison +between the I I have a slope of whatever + + align:start position:0% +between the I I have a slope of whatever + + + align:start position:0% +between the I I have a slope of whatever +it is going along here and I have a + + align:start position:0% +it is going along here and I have a + + + align:start position:0% +it is going along here and I have a +slope of a new slope so U Prime of x the + + align:start position:0% +slope of a new slope so U Prime of x the + + + align:start position:0% +slope of a new slope so U Prime of x the +slope jumps + + align:start position:0% +slope jumps + + + align:start position:0% +slope jumps +right and how much does it + + align:start position:0% +right and how much does it + + + align:start position:0% +right and how much does it +jump minus one it drops by one the slope + + align:start position:0% +jump minus one it drops by one the slope + + + align:start position:0% +jump minus one it drops by one the slope +because of because of my minus sign so + + align:start position:0% +because of because of my minus sign so + + + align:start position:0% +because of because of my minus sign so +this tells me that the yeah let me write + + align:start position:0% +this tells me that the yeah let me write + + + align:start position:0% +this tells me that the yeah let me write +that down the slope U Prime of X drops + + align:start position:0% +that down the slope U Prime of X drops + + + align:start position:0% +that down the slope U Prime of X drops +by + + align:start position:0% + + + + align:start position:0% + +one that would give me this is a + + align:start position:0% +one that would give me this is a + + + align:start position:0% +one that would give me this is a +different another way to say what the + + align:start position:0% +different another way to say what the + + + align:start position:0% +different another way to say what the +equation is + + align:start position:0% +equation is + + + align:start position:0% +equation is +asking the equation is looking for two + + align:start position:0% +asking the equation is looking for two + + + align:start position:0% +asking the equation is looking for two +pieces of straight lines that meet at a + + align:start position:0% +pieces of straight lines that meet at a + + + align:start position:0% +pieces of straight lines that meet at a +but their slope drops by one by the way + + align:start position:0% +but their slope drops by one by the way + + + align:start position:0% +but their slope drops by one by the way +what were the slopes it's good to graph + + align:start position:0% +what were the slopes it's good to graph + + + align:start position:0% +what were the slopes it's good to graph +the slopes too uh let me take out the + + align:start position:0% +the slopes too uh let me take out the + + + align:start position:0% +the slopes too uh let me take out the +let me graph the + + align:start position:0% + + + + align:start position:0% + +slopes the slope U Prime the derivative + + align:start position:0% + + + + align:start position:0% + +DX okay what what's the slope here slope + + align:start position:0% +DX okay what what's the slope here slope + + + align:start position:0% +DX okay what what's the slope here slope +is 1 - A in this point right the + + align:start position:0% +is 1 - A in this point right the + + + align:start position:0% +is 1 - A in this point right the +derivative is 1 - A along to here so + + align:start position:0% +derivative is 1 - A along to here so + + + align:start position:0% +derivative is 1 - A along to here so +slope is 1 minus a d d d d and now at x + + align:start position:0% +slope is 1 minus a d d d d and now at x + + + align:start position:0% +slope is 1 minus a d d d d and now at x +equal a the slope changes to this one + + align:start position:0% +equal a the slope changes to this one + + + align:start position:0% +equal a the slope changes to this one +and what's the slope of that second + + align:start position:0% +and what's the slope of that second + + + align:start position:0% +and what's the slope of that second +part minus a look it did it right minus + + align:start position:0% +part minus a look it did it right minus + + + align:start position:0% +part minus a look it did it right minus +a is the slope along + + align:start position:0% +a is the slope along + + + align:start position:0% +a is the slope along +here you see one minus a it dropped by + + align:start position:0% +here you see one minus a it dropped by + + + align:start position:0% +here you see one minus a it dropped by +one the one disappeared to leave a slope + + align:start position:0% +one the one disappeared to leave a slope + + + align:start position:0% +one the one disappeared to leave a slope +of minus a that's what the + + align:start position:0% +of minus a that's what the + + + align:start position:0% +of minus a that's what the +the you know I guess if I just imagine a + + align:start position:0% +the you know I guess if I just imagine a + + + align:start position:0% +the you know I guess if I just imagine a +imagine a bar I'm fixing it at both + + align:start position:0% +imagine a bar I'm fixing it at both + + + align:start position:0% +imagine a bar I'm fixing it at both +ends okay there's a + + align:start position:0% + + + + align:start position:0% + +bar and + + align:start position:0% +bar and + + + align:start position:0% +bar and +we'll I'm just thinking for people who + + align:start position:0% +we'll I'm just thinking for people who + + + align:start position:0% +we'll I'm just thinking for people who +like to see a physical picture of what's + + align:start position:0% +like to see a physical picture of what's + + + align:start position:0% +like to see a physical picture of what's +Happening that's what this is we'll do + + align:start position:0% +Happening that's what this is we'll do + + + align:start position:0% +Happening that's what this is we'll do +it properly very very soon okay I've got + + align:start position:0% +it properly very very soon okay I've got + + + align:start position:0% +it properly very very soon okay I've got +a + + align:start position:0% +a + + + align:start position:0% +a +bar it's a very light bar it's it's its + + align:start position:0% +bar it's a very light bar it's it's its + + + align:start position:0% +bar it's a very light bar it's it's its +weight is not a a problem here but it's + + align:start position:0% +weight is not a a problem here but it's + + + align:start position:0% +weight is not a a problem here but it's +got a load at the point so I'll measure + + align:start position:0% +got a load at the point so I'll measure + + + align:start position:0% +got a load at the point so I'll measure +X going downwards and at the point x + + align:start position:0% +X going downwards and at the point x + + + align:start position:0% +X going downwards and at the point x +equal a I'm hanging a heavy load + + align:start position:0% +equal a I'm hanging a heavy load + + + align:start position:0% +equal a I'm hanging a heavy load +okay a load how do I draw a + + align:start position:0% +okay a load how do I draw a + + + align:start position:0% +okay a load how do I draw a +load + + align:start position:0% + + + + align:start position:0% + +maybe a like a big weight or + + align:start position:0% + + + + align:start position:0% + +something okay that's a it's a + + align:start position:0% +something okay that's a it's a + + + align:start position:0% +something okay that's a it's a +he what what's going to happen to this + + align:start position:0% +he what what's going to happen to this + + + align:start position:0% +he what what's going to happen to this +dumb bar uh when when uh when I when I + + align:start position:0% +dumb bar uh when when uh when I when I + + + align:start position:0% +dumb bar uh when when uh when I when I +do + + align:start position:0% +do + + + align:start position:0% +do +that just tell me physically what's + + align:start position:0% +that just tell me physically what's + + + align:start position:0% +that just tell me physically what's +going to happen what's going to happen + + align:start position:0% +going to happen what's going to happen + + + align:start position:0% +going to happen what's going to happen +above the + + align:start position:0% +above the + + + align:start position:0% +above the +load it's going to stretch right tension + + align:start position:0% +load it's going to stretch right tension + + + align:start position:0% +load it's going to stretch right tension +the the the bar is going + + align:start position:0% +the the the bar is going + + + align:start position:0% +the the the bar is going +to the load is going to pull the bar + + align:start position:0% +to the load is going to pull the bar + + + align:start position:0% +to the load is going to pull the bar +down it's going to stretch this part and + + align:start position:0% +down it's going to stretch this part and + + + align:start position:0% +down it's going to stretch this part and +because nothing special is happening + + align:start position:0% +because nothing special is happening + + + align:start position:0% +because nothing special is happening +it's going to stretch it + + align:start position:0% +it's going to stretch it + + + align:start position:0% +it's going to stretch it +linearly and then what's going to happen + + align:start position:0% +linearly and then what's going to happen + + + align:start position:0% +linearly and then what's going to happen +below the + + align:start position:0% +below the + + + align:start position:0% +below the +load + + align:start position:0% +load + + + align:start position:0% +load +compression so the slope will go + + align:start position:0% +compression so the slope will go + + + align:start position:0% +compression so the slope will go +negative and nothing special happens so + + align:start position:0% +negative and nothing special happens so + + + align:start position:0% +negative and nothing special happens so +it the slope will be negative but it'll + + align:start position:0% +it the slope will be negative but it'll + + + align:start position:0% +it the slope will be negative but it'll +be constant the slope will drop from + + align:start position:0% +be constant the slope will drop from + + + align:start position:0% +be constant the slope will drop from +this to this the displacement the the + + align:start position:0% +this to this the displacement the the + + + align:start position:0% +this to this the displacement the the +that point will go down a little + + align:start position:0% + + + + align:start position:0% + +bit that little bit it goes down is + + align:start position:0% +bit that little bit it goes down is + + + align:start position:0% +bit that little bit it goes down is +actually the height of this is is that + + align:start position:0% +actually the height of this is is that + + + align:start position:0% +actually the height of this is is that +because that's the displacement that + + align:start position:0% +because that's the displacement that + + + align:start position:0% +because that's the displacement that +it'll go down a little bit it'll stretch + + align:start position:0% +it'll go down a little bit it'll stretch + + + align:start position:0% +it'll go down a little bit it'll stretch +above it'll compress below and we see + + align:start position:0% +above it'll compress below and we see + + + align:start position:0% +above it'll compress below and we see +that in that picture of the displacement + + align:start position:0% +that in that picture of the displacement + + + align:start position:0% +that in that picture of the displacement +displacements it the displacement is all + + align:start position:0% +displacements it the displacement is all + + + align:start position:0% +displacements it the displacement is all +down right displacement you know nature + + align:start position:0% +down right displacement you know nature + + + align:start position:0% +down right displacement you know nature +is still going to all the the bar is + + align:start position:0% +is still going to all the the bar is + + + align:start position:0% +is still going to all the the bar is +going to move down that's why this uh + + align:start position:0% +going to move down that's why this uh + + + align:start position:0% +going to move down that's why this uh +function doesn't this function the + + align:start position:0% +function doesn't this function the + + + align:start position:0% +function doesn't this function the +displacement function is positive it + + align:start position:0% +displacement function is positive it + + + align:start position:0% +displacement function is positive it +goes all down but the slope function is + + align:start position:0% +goes all down but the slope function is + + + align:start position:0% +goes all down but the slope function is +positive here so so tension is positive + + align:start position:0% +positive here so so tension is positive + + + align:start position:0% +positive here so so tension is positive +slope stretch a and compression is + + align:start position:0% +slope stretch a and compression is + + + align:start position:0% +slope stretch a and compression is +negative + + align:start position:0% +negative + + + align:start position:0% +negative +okay well all that to solve um this + + align:start position:0% +okay well all that to solve um this + + + align:start position:0% +okay well all that to solve um this +equation maybe while we're on a roll + + align:start position:0% +equation maybe while we're on a roll + + + align:start position:0% +equation maybe while we're on a roll +let's solve + + align:start position:0% +let's solve + + + align:start position:0% +let's solve +the free fixed guy so this is our we're + + align:start position:0% +the free fixed guy so this is our we're + + + align:start position:0% +the free fixed guy so this is our we're +might as well be systematic this was the + + align:start position:0% +might as well be systematic this was the + + + align:start position:0% +might as well be systematic this was the +fixed fixed problem let me below it + + align:start position:0% +fixed fixed problem let me below it + + + align:start position:0% +fixed fixed problem let me below it +solve the freef fix problem so it'll be + + align:start position:0% +solve the freef fix problem so it'll be + + + align:start position:0% +solve the freef fix problem so it'll be +minus U Prime that's the second + + align:start position:0% +minus U Prime that's the second + + + align:start position:0% +minus U Prime that's the second +derivative equals Delta at x minus a + + align:start position:0% +derivative equals Delta at x minus a + + + align:start position:0% +derivative equals Delta at x minus a +same same setup but now the top end + + align:start position:0% +same same setup but now the top end + + + align:start position:0% +same same setup but now the top end +is what's so it's free at the top what + + align:start position:0% +is what's so it's free at the top what + + + align:start position:0% +is what's so it's free at the top what +does that + + align:start position:0% +does that + + + align:start position:0% +does that +mean slope is + + align:start position:0% +mean slope is + + + align:start position:0% +mean slope is +zero at the top and the but it's still + + align:start position:0% +zero at the top and the but it's still + + + align:start position:0% +zero at the top and the but it's still +fixed at the bottom okay so this will be + + align:start position:0% +fixed at the bottom okay so this will be + + + align:start position:0% +fixed at the bottom okay so this will be +now + + align:start position:0% + + + + align:start position:0% + +free + + align:start position:0% + + + + align:start position:0% + +fixed let let me go straight to the + + align:start position:0% +fixed let let me go straight to the + + + align:start position:0% +fixed let let me go straight to the +picture let me go straight to the + + align:start position:0% +picture let me go straight to the + + + align:start position:0% +picture let me go straight to the +picture of U of + + align:start position:0% +picture of U of + + + align:start position:0% +picture of U of +X so there is x equal 0 there's xal 1 + + align:start position:0% +X so there is x equal 0 there's xal 1 + + + align:start position:0% +X so there is x equal 0 there's xal 1 +here's the load at a what's + + align:start position:0% +here's the load at a what's + + + align:start position:0% +here's the load at a what's +up and I can I I'll while you're + + align:start position:0% +up and I can I I'll while you're + + + align:start position:0% +up and I can I I'll while you're +thinking about that let me draw a + + align:start position:0% +thinking about that let me draw a + + + align:start position:0% +thinking about that let me draw a +picture to match this picture a + + align:start position:0% + + + + align:start position:0% + +bar fixed at the + + align:start position:0% +bar fixed at the + + + align:start position:0% +bar fixed at the +bottom but not at the top okay and it's + + align:start position:0% +bottom but not at the top okay and it's + + + align:start position:0% +bottom but not at the top okay and it's +got its load here hanging + + align:start position:0% +got its load here hanging + + + align:start position:0% +got its load here hanging +down okay but let's do it math first and + + align:start position:0% +down okay but let's do it math first and + + + align:start position:0% +down okay but let's do it math first and +then check with the + + align:start position:0% +then check with the + + + align:start position:0% +then check with the +picture + + align:start position:0% + + + + align:start position:0% + +okay what we got two or three ways now + + align:start position:0% +okay what we got two or three ways now + + + align:start position:0% +okay what we got two or three ways now +to try to get the answer the systematic + + align:start position:0% +to try to get the answer the systematic + + + align:start position:0% +to try to get the answer the systematic +way would be to write down this + + align:start position:0% +way would be to write down this + + + align:start position:0% +way would be to write down this +solution and plug in the two boundary + + align:start position:0% + + + + align:start position:0% + +conditions that'd be that'd be a + + align:start position:0% +conditions that'd be that'd be a + + + align:start position:0% +conditions that'd be that'd be a +straightforward way yeah let's we could + + align:start position:0% +straightforward way yeah let's we could + + + align:start position:0% +straightforward way yeah let's we could +even start by so u u of X + + align:start position:0% +even start by so u u of X + + + align:start position:0% +even start by so u u of X +is the particular solution the the ramp + + align:start position:0% +is the particular solution the the ramp + + + align:start position:0% +is the particular solution the the ramp +plus NE CX plus + + align:start position:0% +plus NE CX plus + + + align:start position:0% +plus NE CX plus +d and + + align:start position:0% + + + + align:start position:0% + +just plug in x equals z that shouldn't + + align:start position:0% +just plug in x equals z that shouldn't + + + align:start position:0% +just plug in x equals z that shouldn't +be that'll be easy if I plug in x equals + + align:start position:0% +be that'll be easy if I plug in x equals + + + align:start position:0% +be that'll be easy if I plug in x equals +0 in in the in the free condition what + + align:start position:0% +0 in in the in the free condition what + + + align:start position:0% +0 in in the in the free condition what +does that tell me at x equals z this + + align:start position:0% +does that tell me at x equals z this + + + align:start position:0% +does that tell me at x equals z this +corner this ramp hasn't started so the + + align:start position:0% +corner this ramp hasn't started so the + + + align:start position:0% +corner this ramp hasn't started so the +slope is zero the slope of the constant + + align:start position:0% +slope is zero the slope of the constant + + + align:start position:0% +slope is zero the slope of the constant +is zero what do I learn from this + + align:start position:0% +is zero what do I learn from this + + + align:start position:0% +is zero what do I learn from this +boundary condition U Prime of Z equals + + align:start position:0% +boundary condition U Prime of Z equals + + + align:start position:0% +boundary condition U Prime of Z equals +z that c is zero before I learned that D + + align:start position:0% +z that c is zero before I learned that D + + + align:start position:0% +z that c is zero before I learned that D +was Zero but now from that condition I'm + + align:start position:0% +was Zero but now from that condition I'm + + + align:start position:0% +was Zero but now from that condition I'm +going to learn C is + + align:start position:0% + + + + align:start position:0% + +zero do the picture for + + align:start position:0% +zero do the picture for + + + align:start position:0% +zero do the picture for +me do the picture for me the what's the + + align:start position:0% +me do the picture for me the what's the + + + align:start position:0% +me do the picture for me the what's the +graph of the this is a graph of of + + align:start position:0% + + + + align:start position:0% + +X remember now it starts from zero + + align:start position:0% +X remember now it starts from zero + + + align:start position:0% +X remember now it starts from zero +slope because it's free at the top what + + align:start position:0% +slope because it's free at the top what + + + align:start position:0% +slope because it's free at the top what +does the graph look like in the first + + align:start position:0% +does the graph look like in the first + + + align:start position:0% +does the graph look like in the first +part + + align:start position:0% +part + + + align:start position:0% +part +yep it's a straight line has to be a + + align:start position:0% +yep it's a straight line has to be a + + + align:start position:0% +yep it's a straight line has to be a +straight line because there's no + + align:start position:0% +straight line because there's no + + + align:start position:0% +straight line because there's no +force and what kind of a + + align:start position:0% +force and what kind of a + + + align:start position:0% +force and what kind of a +line it's going to be + + align:start position:0% +line it's going to be + + + align:start position:0% +line it's going to be +horizontal because it starts out + + align:start position:0% +horizontal because it starts out + + + align:start position:0% +horizontal because it starts out +horizontal the the slope has to be zero + + align:start position:0% +horizontal the the slope has to be zero + + + align:start position:0% +horizontal the the slope has to be zero +at zero and nothing changes until a so + + align:start position:0% +at zero and nothing changes until a so + + + align:start position:0% +at zero and nothing changes until a so +it comes along + + align:start position:0% +it comes along + + + align:start position:0% +it comes along +there right okay so that's now I've + + align:start position:0% +there right okay so that's now I've + + + align:start position:0% +there right okay so that's now I've +started out with the right left the + + align:start position:0% +started out with the right left the + + + align:start position:0% +started out with the right left the +correct boundary condition at zero which + + align:start position:0% +correct boundary condition at zero which + + + align:start position:0% +correct boundary condition at zero which +was no slope and now what's it going to + + align:start position:0% +was no slope and now what's it going to + + + align:start position:0% +was no slope and now what's it going to +do the other half from a to + + align:start position:0% +do the other half from a to + + + align:start position:0% +do the other half from a to +one it's going to be again it'll be a + + align:start position:0% +one it's going to be again it'll be a + + + align:start position:0% +one it's going to be again it'll be a +straight line right because there's no + + align:start position:0% +straight line right because there's no + + + align:start position:0% +straight line right because there's no +Force there and what happens at the all + + align:start position:0% +Force there and what happens at the all + + + align:start position:0% +Force there and what happens at the all +the action of course is at this point a + + align:start position:0% +the action of course is at this point a + + + align:start position:0% +the action of course is at this point a +and what action is it tell me what sort + + align:start position:0% +and what action is it tell me what sort + + + align:start position:0% +and what action is it tell me what sort +of a + + align:start position:0% +of a + + + align:start position:0% +of a +line how do I finish the + + align:start position:0% + + + + align:start position:0% + +picture what do I + + align:start position:0% +picture what do I + + + align:start position:0% +picture what do I +do I I start here right because the the + + align:start position:0% +do I I start here right because the the + + + align:start position:0% +do I I start here right because the the +bar the bar is not coming falling apart + + align:start position:0% +bar the bar is not coming falling apart + + + align:start position:0% +bar the bar is not coming falling apart +u u is continuous I don't get a gap + + align:start position:0% +u u is continuous I don't get a gap + + + align:start position:0% +u u is continuous I don't get a gap +suddenly and now what do I do from + + align:start position:0% +suddenly and now what do I do from + + + align:start position:0% +suddenly and now what do I do from +there only thing I can possibly do is I + + align:start position:0% +there only thing I can possibly do is I + + + align:start position:0% +there only thing I can possibly do is I +have to end up here and it has to be a + + align:start position:0% +have to end up here and it has to be a + + + align:start position:0% +have to end up here and it has to be a +straight line that's + + align:start position:0% + + + + align:start position:0% + +it that's what the picture will have to + + align:start position:0% +it that's what the picture will have to + + + align:start position:0% +it that's what the picture will have to +look like and what does that correspond + + align:start position:0% +look like and what does that correspond + + + align:start position:0% +look like and what does that correspond +to in the in the in the uh picture in + + align:start position:0% +to in the in the in the uh picture in + + + align:start position:0% +to in the in the in the uh picture in +the in the for the bar + + align:start position:0% +the in the for the bar + + + align:start position:0% +the in the for the bar +so well what happens with this bar the + + align:start position:0% +so well what happens with this bar the + + + align:start position:0% +so well what happens with this bar the +above the + + align:start position:0% +above the + + + align:start position:0% +above the +weight what's what happens to this top + + align:start position:0% +weight what's what happens to this top + + + align:start position:0% +weight what's what happens to this top +part of the bar in that + + align:start position:0% +part of the bar in that + + + align:start position:0% +part of the bar in that +picture and what happens to the lower + + align:start position:0% +picture and what happens to the lower + + + align:start position:0% +picture and what happens to the lower +part of the bar so this is this was at + + align:start position:0% +part of the bar so this is this was at + + + align:start position:0% +part of the bar so this is this was at +the point x equal a this is x equal Zer + + align:start position:0% +the point x equal a this is x equal Zer + + + align:start position:0% +the point x equal a this is x equal Zer +this is xal 1 what happens above the bar + + align:start position:0% +this is xal 1 what happens above the bar + + + align:start position:0% +this is xal 1 what happens above the bar +above the + + align:start position:0% +above the + + + align:start position:0% +above the +weight it just it just a rigid motion + + align:start position:0% +weight it just it just a rigid motion + + + align:start position:0% +weight it just it just a rigid motion +just goes down but because what happens + + align:start position:0% +just goes down but because what happens + + + align:start position:0% +just goes down but because what happens +below the weight is same compression or + + align:start position:0% +below the weight is same compression or + + + align:start position:0% +below the weight is same compression or +compression still happening this is + + align:start position:0% +compression still happening this is + + + align:start position:0% +compression still happening this is +still squeezed shall I try to draw + + align:start position:0% +still squeezed shall I try to draw + + + align:start position:0% +still squeezed shall I try to draw +it so this is after after the weight + + align:start position:0% +it so this is after after the weight + + + align:start position:0% +it so this is after after the weight +this is this got squeezed but this part + + align:start position:0% +this is this got squeezed but this part + + + align:start position:0% +this is this got squeezed but this part +did not get squeezed and that's what + + align:start position:0% +did not get squeezed and that's what + + + align:start position:0% +did not get squeezed and that's what +we're seeing + + align:start position:0% + + + + align:start position:0% + +here uh no fixed this displacement so + + align:start position:0% +here uh no fixed this displacement so + + + align:start position:0% +here uh no fixed this displacement so +this is this means that that picture + + align:start position:0% +this is this means that that picture + + + align:start position:0% +this is this means that that picture +means that all the all + + align:start position:0% +means that all the all + + + align:start position:0% +means that all the all +the pieces of the bar here got moved + + align:start position:0% +the pieces of the bar here got moved + + + align:start position:0% +the pieces of the bar here got moved +down by the same amount whatever this we + + align:start position:0% +down by the same amount whatever this we + + + align:start position:0% +down by the same amount whatever this we +don't know that number + + align:start position:0% +don't know that number + + + align:start position:0% +don't know that number +yet and then + + align:start position:0% +yet and then + + + align:start position:0% +yet and then +uh below it they got + + align:start position:0% +uh below it they got + + + align:start position:0% +uh below it they got +compressed well we're almost there but + + align:start position:0% +compressed well we're almost there but + + + align:start position:0% +compressed well we're almost there but +we don't get have that solution what's + + align:start position:0% +we don't get have that solution what's + + + align:start position:0% +we don't get have that solution what's +the how come back to this picture U of + + align:start position:0% +the how come back to this picture U of + + + align:start position:0% +the how come back to this picture U of +AIS is continuous got it and what's the + + align:start position:0% +AIS is continuous got it and what's the + + + align:start position:0% +AIS is continuous got it and what's the +what's the real condition that's going + + align:start position:0% +what's the real condition that's going + + + align:start position:0% +what's the real condition that's going +to + + align:start position:0% +to + + + align:start position:0% +to +determine where we are what that what + + align:start position:0% +determine where we are what that what + + + align:start position:0% +determine where we are what that what +those Heights are the the numbers in + + align:start position:0% +those Heights are the the numbers in + + + align:start position:0% +those Heights are the the numbers in +there it it's got to look like that but + + align:start position:0% +there it it's got to look like that but + + + align:start position:0% +there it it's got to look like that but +what what we got more than that we got + + align:start position:0% +what what we got more than that we got + + + align:start position:0% +what what we got more than that we got +to know what are the actual what is that + + align:start position:0% +to know what are the actual what is that + + + align:start position:0% +to know what are the actual what is that +height what is this what's the slope + + align:start position:0% +height what is this what's the slope + + + align:start position:0% +height what is this what's the slope +here the slope is + + align:start position:0% + + + + align:start position:0% + +zero here the slope is + + align:start position:0% + + + + align:start position:0% + +what what's the slope in the second part + + align:start position:0% +what what's the slope in the second part + + + align:start position:0% +what what's the slope in the second part +that's the + + align:start position:0% +that's the + + + align:start position:0% +that's the +key and you know what it has to be + + align:start position:0% +key and you know what it has to be + + + align:start position:0% +key and you know what it has to be +because what happens to the slope if if + + align:start position:0% +because what happens to the slope if if + + + align:start position:0% +because what happens to the slope if if +I have the second derivative as a Delta + + align:start position:0% +I have the second derivative as a Delta + + + align:start position:0% +I have the second derivative as a Delta +function with that minus sign the + + align:start position:0% +function with that minus sign the + + + align:start position:0% +function with that minus sign the +slope drops + + align:start position:0% +slope drops + + + align:start position:0% +slope drops +by + + align:start position:0% +by + + + align:start position:0% +by +one and the slope here is zero so the + + align:start position:0% +one and the slope here is zero so the + + + align:start position:0% +one and the slope here is zero so the +slope here + + align:start position:0% +slope here + + + align:start position:0% +slope here +isus one and now and it has to get + + align:start position:0% +isus one and now and it has to get + + + align:start position:0% +isus one and now and it has to get +through there so what is the + + align:start position:0% +through there so what is the + + + align:start position:0% +through there so what is the +function what's the function that has a + + align:start position:0% +function what's the function that has a + + + align:start position:0% +function what's the function that has a +slope of minus1 and comes down to + + align:start position:0% + + + + align:start position:0% + +zero + + align:start position:0% + + + + align:start position:0% + +it's it's it's got to have a minus X in + + align:start position:0% +it's it's it's got to have a minus X in + + + align:start position:0% +it's it's it's got to have a minus X in +it and what's the constant to make it + + align:start position:0% +it and what's the constant to make it + + + align:start position:0% +it and what's the constant to make it +come out right + + align:start position:0% + + + + align:start position:0% + +yeah what do I write now here for U of + + align:start position:0% +yeah what do I write now here for U of + + + align:start position:0% +yeah what do I write now here for U of +x- x 1 - x that has a slope of minus one + + align:start position:0% +x- x 1 - x that has a slope of minus one + + + align:start position:0% +x- x 1 - x that has a slope of minus one +the derivative is minus1 at x equal 1 it + + align:start position:0% +the derivative is minus1 at x equal 1 it + + + align:start position:0% +the derivative is minus1 at x equal 1 it +comes to zero that's it and what do I + + align:start position:0% +comes to zero that's it and what do I + + + align:start position:0% +comes to zero that's it and what do I +write what's U of X up + + align:start position:0% +write what's U of X up + + + align:start position:0% +write what's U of X up +here and therefore right there what + + align:start position:0% +here and therefore right there what + + + align:start position:0% +here and therefore right there what +what's what's the yeah what what's the + + align:start position:0% +what's what's the yeah what what's the + + + align:start position:0% +what's what's the yeah what what's the +displacement there of all this bit that + + align:start position:0% +displacement there of all this bit that + + + align:start position:0% +displacement there of all this bit that +moves down how much does it move + + align:start position:0% +moves down how much does it move + + + align:start position:0% +moves down how much does it move +down one minus a why one minus a that's + + align:start position:0% +down one minus a why one minus a that's + + + align:start position:0% +down one minus a why one minus a that's +the right answer one minus + + align:start position:0% +the right answer one minus + + + align:start position:0% +the right answer one minus +a why is + + align:start position:0% +a why is + + + align:start position:0% +a why is +that because it had to match up at x + + align:start position:0% +that because it had to match up at x + + + align:start position:0% +that because it had to match up at x +equal a at x equal a this and that match + + align:start position:0% +equal a at x equal a this and that match + + + align:start position:0% +equal a at x equal a this and that match +up at x equal a that slope that function + + align:start position:0% +up at x equal a that slope that function + + + align:start position:0% +up at x equal a that slope that function +and that function match up so the the + + align:start position:0% +and that function match up so the the + + + align:start position:0% +and that function match up so the the +slope the the slope picture is zero and + + align:start position:0% +slope the the slope picture is zero and + + + align:start position:0% +slope the the slope picture is zero and +oh I'm sorry this can't draw it because + + align:start position:0% +oh I'm sorry this can't draw it because + + + align:start position:0% +oh I'm sorry this can't draw it because +I got I'm at the bottom of the board the + + align:start position:0% +I got I'm at the bottom of the board the + + + align:start position:0% +I got I'm at the bottom of the board the +slope picture maybe I can draw it here + + align:start position:0% +slope picture maybe I can draw it here + + + align:start position:0% +slope picture maybe I can draw it here +the slope picture is zero along to here + + align:start position:0% +the slope picture is zero along to here + + + align:start position:0% +the slope picture is zero along to here +and then it drops by one to one minus a + + align:start position:0% +and then it drops by one to one minus a + + + align:start position:0% +and then it drops by one to one minus a +so that's a picture of U Prime zero and + + align:start position:0% +so that's a picture of U Prime zero and + + + align:start position:0% +so that's a picture of U Prime zero and +minus + + align:start position:0% +minus + + + align:start position:0% +minus +one this this is the thing to look + + align:start position:0% + + + + align:start position:0% + +at okay + + align:start position:0% +at okay + + + align:start position:0% +at okay +that's uh that's hard work when you were + + align:start position:0% +that's uh that's hard work when you were + + + align:start position:0% +that's uh that's hard work when you were +seeing Delta functions the first time + + align:start position:0% +seeing Delta functions the first time + + + align:start position:0% +seeing Delta functions the first time +but of course the functions did not get + + align:start position:0% +but of course the functions did not get + + + align:start position:0% +but of course the functions did not get +complicated we kept a clean uh uh + + align:start position:0% +complicated we kept a clean uh uh + + + align:start position:0% +complicated we kept a clean uh uh +example and from which which we man + + align:start position:0% +example and from which which we man + + + align:start position:0% +example and from which which we man +which we matched up with a figure and + + align:start position:0% +which we matched up with a figure and + + + align:start position:0% +which we matched up with a figure and +we've got the answer and we've got a + + align:start position:0% +we've got the answer and we've got a + + + align:start position:0% +we've got the answer and we've got a +couple of ways to do it one is this uh + + align:start position:0% +couple of ways to do it one is this uh + + + align:start position:0% +couple of ways to do it one is this uh +uh standard systematic plug-in boundary + + align:start position:0% +uh standard systematic plug-in boundary + + + align:start position:0% +uh standard systematic plug-in boundary +condition way the other way is + + align:start position:0% +condition way the other way is + + + align:start position:0% +condition way the other way is +this U of X does something here then the + + align:start position:0% +this U of X does something here then the + + + align:start position:0% +this U of X does something here then the +slope has to drop by one and that that's + + align:start position:0% +slope has to drop by one and that that's + + + align:start position:0% +slope has to drop by one and that that's +the that's the key to everything with + + align:start position:0% +the that's the key to everything with + + + align:start position:0% +the that's the key to everything with +the boundary condition so in a way we + + align:start position:0% +the boundary condition so in a way we + + + align:start position:0% +the boundary condition so in a way we +have a piece to the left and a piece to + + align:start position:0% +have a piece to the left and a piece to + + + align:start position:0% +have a piece to the left and a piece to +the right two constants here two + + align:start position:0% +the right two constants here two + + + align:start position:0% +the right two constants here two +constants here and somewhere there are + + align:start position:0% +constants here and somewhere there are + + + align:start position:0% +constants here and somewhere there are +four conditions that settle those four + + align:start position:0% +four conditions that settle those four + + + align:start position:0% +four conditions that settle those four +constants you know we could have a + + align:start position:0% +constants you know we could have a + + + align:start position:0% +constants you know we could have a +straight line here a straight line here + + align:start position:0% +straight line here a straight line here + + + align:start position:0% +straight line here a straight line here +that's two and two two but what are the + + align:start position:0% +that's two and two two but what are the + + + align:start position:0% +that's two and two two but what are the +four conditions that that settle those + + align:start position:0% +four conditions that that settle those + + + align:start position:0% +four conditions that that settle those +four constants well we have a boundary + + align:start position:0% +four constants well we have a boundary + + + align:start position:0% +four constants well we have a boundary +condition here that's one boundary + + align:start position:0% +condition here that's one boundary + + + align:start position:0% +condition here that's one boundary +condition here is two we need two more + + align:start position:0% +condition here is two we need two more + + + align:start position:0% +condition here is two we need two more +conditions to settle the the two pairs + + align:start position:0% +conditions to settle the the two pairs + + + align:start position:0% +conditions to settle the the two pairs +of constants and there they are that's + + align:start position:0% +of constants and there they are that's + + + align:start position:0% +of constants and there they are that's +the condition at the and that two two + + align:start position:0% +the condition at the and that two two + + + align:start position:0% +the condition at the and that two two +more two conditions at the at the uh + + align:start position:0% +more two conditions at the at the uh + + + align:start position:0% +more two conditions at the at the uh +jump at the at the uh discontinuity okay + + align:start position:0% + + + + align:start position:0% + +now I've got to do the discrete + + align:start position:0% +now I've got to do the discrete + + + align:start position:0% +now I've got to do the discrete +case are you up for the discrete + + align:start position:0% +case are you up for the discrete + + + align:start position:0% +case are you up for the discrete +case the case where uh we're doing we + + align:start position:0% +case the case where uh we're doing we + + + align:start position:0% +case the case where uh we're doing we +have a difference + + align:start position:0% +have a difference + + + align:start position:0% +have a difference +equation so we're doing KU equal a + + align:start position:0% +equation so we're doing KU equal a + + + align:start position:0% +equation so we're doing KU equal a +column of the identity column of + + align:start position:0% + + + + align:start position:0% + +I + + align:start position:0% +I + + + align:start position:0% +I +let let me just take it to be let me + + align:start position:0% +let let me just take it to be let me + + + align:start position:0% +let let me just take it to be let me +take a + + align:start position:0% +take a + + + align:start position:0% +take a +specific column say 0 1 Z Zer Zer let + + align:start position:0% +specific column say 0 1 Z Zer Zer let + + + align:start position:0% +specific column say 0 1 Z Zer Zer let +let let's suppose we have + + align:start position:0% +let let's suppose we have + + + align:start position:0% +let let's suppose we have +five I'm going to draw a picture + + align:start position:0% +five I'm going to draw a picture + + + align:start position:0% +five I'm going to draw a picture +now we have five because I made it five + + align:start position:0% +now we have five because I made it five + + + align:start position:0% +now we have five because I made it five +by five 1 two three four five here is + + align:start position:0% +by five 1 two three four five here is + + + align:start position:0% +by five 1 two three four five here is +zero and here is six so H is 1 over 5 + + + align:start position:0% +zero and here is six so H is 1 over 5 + + + + align:start position:0% +zero and here is six so H is 1 over 5 + +1 1 16 that's the Delta X + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +now and my equation says so what is my + + align:start position:0% +now and my equation says so what is my + + + align:start position:0% +now and my equation says so what is my +equation say remember what K is K + + align:start position:0% +equation say remember what K is K + + + align:start position:0% +equation say remember what K is K +is U is then U1 U2 u3 u4 and u5 the + + align:start position:0% +is U is then U1 U2 u3 u4 and u5 the + + + align:start position:0% +is U is then U1 U2 u3 u4 and u5 the +unknowns K is our old friend with + + align:start position:0% +unknowns K is our old friend with + + + align:start position:0% +unknowns K is our old friend with +twos and minus + + align:start position:0% +twos and minus + + + align:start position:0% +twos and minus +On's and minus + + align:start position:0% +On's and minus + + + align:start position:0% +On's and minus +On's + + align:start position:0% + + + + align:start position:0% + +okay I'm going to find the solution and + + align:start position:0% +okay I'm going to find the solution and + + + align:start position:0% +okay I'm going to find the solution and +this will be a partic this will be the + + align:start position:0% +this will be a partic this will be the + + + align:start position:0% +this will be a partic this will be the +solution that has a load at this point + + align:start position:0% +solution that has a load at this point + + + align:start position:0% +solution that has a load at this point +this is like my point a right here the + + align:start position:0% +this is like my point a right here the + + + align:start position:0% +this is like my point a right here the +point in the continuous case a could run + + align:start position:0% +point in the continuous case a could run + + + align:start position:0% +point in the continuous case a could run +anywhere between zero and one in the + + align:start position:0% +anywhere between zero and one in the + + + align:start position:0% +anywhere between zero and one in the +discrete case I've got five possible + + align:start position:0% +discrete case I've got five possible + + + align:start position:0% +discrete case I've got five possible +load points and I picked the second one + + align:start position:0% +load points and I picked the second one + + + align:start position:0% +load points and I picked the second one +five columns of the identity Matrix five + + align:start position:0% +five columns of the identity Matrix five + + + align:start position:0% +five columns of the identity Matrix five +places to put that one I put it there + + align:start position:0% +places to put that one I put it there + + + align:start position:0% +places to put that one I put it there +okay + + align:start position:0% +okay + + + align:start position:0% +okay +now can I draw the picture here should + + align:start position:0% +now can I draw the picture here should + + + align:start position:0% +now can I draw the picture here should +we do + + align:start position:0% +we do + + + align:start position:0% +we do +the which should we do first should we + + align:start position:0% +the which should we do first should we + + + align:start position:0% +the which should we do first should we +do freef fixed because that came + + align:start position:0% +do freef fixed because that came + + + align:start position:0% +do freef fixed because that came +out even easier than fixed fixed notice + + align:start position:0% +out even easier than fixed fixed notice + + + align:start position:0% +out even easier than fixed fixed notice +the the solution here had two parts this + + align:start position:0% +the the solution here had two parts this + + + align:start position:0% +the the solution here had two parts this +is the way I would write that + + align:start position:0% +is the way I would write that + + + align:start position:0% +is the way I would write that +answer because you could draw a picture + + align:start position:0% +answer because you could draw a picture + + + align:start position:0% +answer because you could draw a picture +but if you want to write the + + align:start position:0% +but if you want to write the + + + align:start position:0% +but if you want to write the +formula uh what would I do I would break + + align:start position:0% +formula uh what would I do I would break + + + align:start position:0% +formula uh what would I do I would break +it into two + + align:start position:0% +it into two + + + align:start position:0% +it into two +pieces uh 1 minus a up to the point + + align:start position:0% +pieces uh 1 minus a up to the point + + + align:start position:0% +pieces uh 1 minus a up to the point +a and because that's what it was running + + align:start position:0% +a and because that's what it was running + + + align:start position:0% +a and because that's what it was running +along here and then down here it was 1 + + align:start position:0% +along here and then down here it was 1 + + + align:start position:0% +along here and then down here it was 1 +minus + + align:start position:0% +minus + + + align:start position:0% +minus +x x greater or equal + + align:start position:0% +x x greater or equal + + + align:start position:0% +x x greater or equal +a + + align:start position:0% + + + + align:start position:0% + +yeah that's important to mention you you + + align:start position:0% +yeah that's important to mention you you + + + align:start position:0% +yeah that's important to mention you you +have to have some guidance on how to + + align:start position:0% +have to have some guidance on how to + + + align:start position:0% +have to have some guidance on how to +write the answer and when the answer has + + align:start position:0% +write the answer and when the answer has + + + align:start position:0% +write the answer and when the answer has +two parts this is a good way to write it + + align:start position:0% +two parts this is a good way to write it + + + align:start position:0% +two parts this is a good way to write it +in two parts it's a little too you're + + align:start position:0% +in two parts it's a little too you're + + + align:start position:0% +in two parts it's a little too you're +compressing it too much to write to use + + align:start position:0% +compressing it too much to write to use + + + align:start position:0% +compressing it too much to write to use +that ramp function you can better to + + align:start position:0% +that ramp function you can better to + + + align:start position:0% +that ramp function you can better to +split it apart into the into before a + + align:start position:0% +split it apart into the into before a + + + align:start position:0% +split it apart into the into before a +and above and after a what's going to + + align:start position:0% +and above and after a what's going to + + + align:start position:0% +and above and after a what's going to +happen happen + + align:start position:0% +happen happen + + + align:start position:0% +happen happen +over here oh yeah all right let let's + + align:start position:0% +over here oh yeah all right let let's + + + align:start position:0% +over here oh yeah all right let let's +just can we take a shot shot at this + + align:start position:0% +just can we take a shot shot at this + + + align:start position:0% +just can we take a shot shot at this +problem and let + + align:start position:0% +problem and let + + + align:start position:0% +problem and let +me mention again in the + + align:start position:0% +me mention again in the + + + align:start position:0% +me mention again in the +review this that'll be in here this + + align:start position:0% +review this that'll be in here this + + + align:start position:0% +review this that'll be in here this +afternoon and every Wednesday afternoon + + align:start position:0% +afternoon and every Wednesday afternoon + + + align:start position:0% +afternoon and every Wednesday afternoon +um I'll just be ready for questions + + align:start position:0% +um I'll just be ready for questions + + + align:start position:0% +um I'll just be ready for questions +please bring + + align:start position:0% +please bring + + + align:start position:0% +please bring +questions uh they can be questions on + + align:start position:0% +questions uh they can be questions on + + + align:start position:0% +questions uh they can be questions on +the homework even better if they're + + align:start position:0% +the homework even better if they're + + + align:start position:0% +the homework even better if they're +questions on on other problems questions + + align:start position:0% +questions on on other problems questions + + + align:start position:0% +questions on on other problems questions +on the lecture questions + + align:start position:0% +on the lecture questions + + + align:start position:0% +on the lecture questions +yeah questions are essential to make + + align:start position:0% +yeah questions are essential to make + + + align:start position:0% +yeah questions are essential to make +that help session um helpful okay all + + align:start position:0% +that help session um helpful okay all + + + align:start position:0% +that help session um helpful okay all +right what do you think's cooking + + align:start position:0% +right what do you think's cooking + + + align:start position:0% +right what do you think's cooking +here what at a typical a typical uh + + align:start position:0% +here what at a typical a typical uh + + + align:start position:0% +here what at a typical a typical uh +somewhere in the middle + + align:start position:0% +somewhere in the middle + + + align:start position:0% +somewhere in the middle +here I'm I'm going to draw the use I'm + + align:start position:0% +here I'm I'm going to draw the use I'm + + + align:start position:0% +here I'm I'm going to draw the use I'm +going to shall I just draw + + align:start position:0% +going to shall I just draw + + + align:start position:0% +going to shall I just draw +them and and now what's my condition + + align:start position:0% +them and and now what's my condition + + + align:start position:0% +them and and now what's my condition +going my I got to put the boundary + + align:start position:0% +going my I got to put the boundary + + + align:start position:0% +going my I got to put the boundary +conditions on oh I have put the boundary + + align:start position:0% +conditions on oh I have put the boundary + + + align:start position:0% +conditions on oh I have put the boundary +conditions on by by putting that two + + align:start position:0% +conditions on by by putting that two + + + align:start position:0% +conditions on by by putting that two +there I did the I I'm up to here okay + + align:start position:0% +there I did the I I'm up to here okay + + + align:start position:0% +there I did the I I'm up to here okay +let's let's do that + + align:start position:0% +let's let's do that + + + align:start position:0% +let's let's do that +one when I put when I chose + + align:start position:0% +one when I put when I chose + + + align:start position:0% +one when I put when I chose +K and put a two in there I was picking + + align:start position:0% +K and put a two in there I was picking + + + align:start position:0% +K and put a two in there I was picking +the fixed fixed boundary conditions + + align:start position:0% +the fixed fixed boundary conditions + + + align:start position:0% +the fixed fixed boundary conditions +so can can I just say it's going to be + + align:start position:0% +so can can I just say it's going to be + + + align:start position:0% +so can can I just say it's going to be +beautiful the solution over there is + + align:start position:0% +beautiful the solution over there is + + + align:start position:0% +beautiful the solution over there is +going to look like this the solution + + align:start position:0% +going to look like this the solution + + + align:start position:0% +going to look like this the solution +over here is going to be up up up it's + + align:start position:0% +over here is going to be up up up it's + + + align:start position:0% +over here is going to be up up up it's +going to be a straight line but only + + align:start position:0% +going to be a straight line but only + + + align:start position:0% +going to be a straight line but only +points in a line and it'll be straight + + align:start position:0% +points in a line and it'll be straight + + + align:start position:0% +points in a line and it'll be straight +line down that value that value that + + align:start position:0% +line down that value that value that + + + align:start position:0% +line down that value that value that +value those will be U1 U2 u3 u4 and + + align:start position:0% +value those will be U1 U2 u3 u4 and + + + align:start position:0% +value those will be U1 U2 u3 u4 and +u5 okay + + align:start position:0% +u5 okay + + + align:start position:0% +u5 okay +and what's more + + align:start position:0% +and what's more + + + align:start position:0% +and what's more +the this is going to drop by one + + align:start position:0% +the this is going to drop by one + + + align:start position:0% +the this is going to drop by one +again actually I didn't have to redraw + + align:start position:0% +again actually I didn't have to redraw + + + align:start position:0% +again actually I didn't have to redraw +the picture it falls right on I in case + + align:start position:0% +the picture it falls right on I in case + + + align:start position:0% +the picture it falls right on I in case +X is + + align:start position:0% + + + + align:start position:0% + +26 so that it fits that picture the I'm + + align:start position:0% +26 so that it fits that picture the I'm + + + align:start position:0% +26 so that it fits that picture the I'm +claiming we have another + + align:start position:0% +claiming we have another + + + align:start position:0% +claiming we have another +extremely lucky + + align:start position:0% +extremely lucky + + + align:start position:0% +extremely lucky +case if we can use the word lucky for + + align:start position:0% +case if we can use the word lucky for + + + align:start position:0% +case if we can use the word lucky for +for + + align:start position:0% +for + + + align:start position:0% +for +math uh that I'm claiming that the way + + align:start position:0% +math uh that I'm claiming that the way + + + align:start position:0% +math uh that I'm claiming that the way +the you remember for the uniform load + + align:start position:0% +the you remember for the uniform load + + + align:start position:0% +the you remember for the uniform load +with a one with when the when we had + + align:start position:0% +with a one with when the when we had + + + align:start position:0% +with a one with when the when we had +second derivative equal one the solution + + align:start position:0% +second derivative equal one the solution + + + align:start position:0% +second derivative equal one the solution +was a perfect + + align:start position:0% +was a perfect + + + align:start position:0% +was a perfect +Parabola and the discrete solution the + + align:start position:0% +Parabola and the discrete solution the + + + align:start position:0% +Parabola and the discrete solution the +difference equation was right on the + + align:start position:0% +difference equation was right on the + + + align:start position:0% +difference equation was right on the +parabola for this fixed fixed case it's + + align:start position:0% +parabola for this fixed fixed case it's + + + align:start position:0% +parabola for this fixed fixed case it's +going to happen again so it won't always + + align:start position:0% +going to happen again so it won't always + + + align:start position:0% +going to happen again so it won't always +happen those are the only two important + + align:start position:0% +happen those are the only two important + + + align:start position:0% +happen those are the only two important +right hand sides I know that there the + + align:start position:0% +right hand sides I know that there the + + + align:start position:0% +right hand sides I know that there the +two most important right hand sides and + + align:start position:0% +two most important right hand sides and + + + align:start position:0% +two most important right hand sides and +those are the two lucky + + align:start position:0% +those are the two lucky + + + align:start position:0% +those are the two lucky +ones if we have a constant that lies + + align:start position:0% +ones if we have a constant that lies + + + align:start position:0% +ones if we have a constant that lies +right on a parabola if if we have a + + align:start position:0% +right on a parabola if if we have a + + + align:start position:0% +right on a parabola if if we have a +Delta function it lies right on + + align:start position:0% +Delta function it lies right on + + + align:start position:0% +Delta function it lies right on +a + + align:start position:0% +a + + + align:start position:0% +a +ramp and there it is so that's the + + align:start position:0% +ramp and there it is so that's the + + + align:start position:0% +ramp and there it is so that's the +that's what the solution looks like now + + align:start position:0% +that's what the solution looks like now + + + align:start position:0% +that's what the solution looks like now +I have to figure out what these numbers + + align:start position:0% +I have to figure out what these numbers + + + align:start position:0% +I have to figure out what these numbers +are I + + align:start position:0% +are I + + + align:start position:0% +are I +guess yes what are those numbers oh well + + align:start position:0% +guess yes what are those numbers oh well + + + align:start position:0% +guess yes what are those numbers oh well +actually if it falls right on I know the + + align:start position:0% +actually if it falls right on I know the + + + align:start position:0% +actually if it falls right on I know the +numbers yeah so a + + align:start position:0% +numbers yeah so a + + + align:start position:0% +numbers yeah so a +is 2 six one 2 six yeah so let me let me + + align:start position:0% +is 2 six one 2 six yeah so let me let me + + + align:start position:0% +is 2 six one 2 six yeah so let me let me +keep 2 six okay so a is 26 that that's + + align:start position:0% +keep 2 six okay so a is 26 that that's + + + align:start position:0% +keep 2 six okay so a is 26 that that's +that's that value + + align:start position:0% +that's that value + + + align:start position:0% +that's that value +so I let me say what I think U + + align:start position:0% +so I let me say what I think U + + + align:start position:0% +so I let me say what I think U +is so this was a picture of U that's u 1 + + align:start position:0% +is so this was a picture of U that's u 1 + + + align:start position:0% +is so this was a picture of U that's u 1 +2 3 4 and five and now the I think it + + align:start position:0% +2 3 4 and five and now the I think it + + + align:start position:0% +2 3 4 and five and now the I think it +lies right on that so it's going to be 1 + + align:start position:0% +lies right on that so it's going to be 1 + + + align:start position:0% +lies right on that so it's going to be 1 +minus + + align:start position:0% +minus + + + align:start position:0% +minus +26 of X going up and 1 - x * 26 going + + align:start position:0% +26 of X going up and 1 - x * 26 going + + + align:start position:0% +26 of X going up and 1 - x * 26 going +down my my point is that I'll be able to + + align:start position:0% +down my my point is that I'll be able to + + + align:start position:0% +down my my point is that I'll be able to +figure out what that + + align:start position:0% +figure out what that + + + align:start position:0% +figure out what that +uh this is U then this is the U + + align:start position:0% +uh this is U then this is the U + + + align:start position:0% +uh this is U then this is the U +okay you're going to say + + align:start position:0% +okay you're going to say + + + align:start position:0% +okay you're going to say +why before I let me pause before putting + + align:start position:0% +why before I let me pause before putting + + + align:start position:0% +why before I let me pause before putting +in numbers and say why is it how do why + + align:start position:0% +in numbers and say why is it how do why + + + align:start position:0% +in numbers and say why is it how do why +how do I know that the solution is right + + align:start position:0% +how do I know that the solution is right + + + align:start position:0% +how do I know that the solution is right +on the function the the the continuous + + align:start position:0% +on the function the the the continuous + + + align:start position:0% +on the function the the the continuous +solution + + align:start position:0% +solution + + + align:start position:0% +solution +well can I draw a set of pictures just + + align:start position:0% +well can I draw a set of pictures just + + + align:start position:0% +well can I draw a set of pictures just +like those + + align:start position:0% +like those + + + align:start position:0% +like those +guys for discreet yeah let me just draw + + align:start position:0% +guys for discreet yeah let me just draw + + + align:start position:0% +guys for discreet yeah let me just draw +those for a discreete here that that's + + align:start position:0% +those for a discreete here that that's + + + align:start position:0% +those for a discreete here that that's +that's shows you the the magic okay so + + align:start position:0% +that's shows you the the magic okay so + + + align:start position:0% +that's shows you the the magic okay so +so there's + + align:start position:0% + + + + align:start position:0% + +a I'm going to draw a vector now so I'm + + align:start position:0% +a I'm going to draw a vector now so I'm + + + align:start position:0% +a I'm going to draw a vector now so I'm +not it's I'm going to have to lift the + + align:start position:0% +not it's I'm going to have to lift the + + + align:start position:0% +not it's I'm going to have to lift the +chalk it won't a function and it'll be + + align:start position:0% +chalk it won't a function and it'll be + + + align:start position:0% +chalk it won't a function and it'll be +the Delta Vector so it'll be the Delta + + align:start position:0% +the Delta Vector so it'll be the Delta + + + align:start position:0% +the Delta Vector so it'll be the Delta +Vector Delta with so there's 0.1 012 up + + align:start position:0% +Vector Delta with so there's 0.1 012 up + + + align:start position:0% +Vector Delta with so there's 0.1 012 up +to + + align:start position:0% +to + + + align:start position:0% +to +six it'll be the Delta + + align:start position:0% +six it'll be the Delta + + + align:start position:0% +six it'll be the Delta +Vector well if I just draw the Delta + + align:start position:0% +Vector well if I just draw the Delta + + + align:start position:0% +Vector well if I just draw the Delta +Vector the Delta Vector has a one there + + align:start position:0% +Vector the Delta Vector has a one there + + + align:start position:0% +Vector the Delta Vector has a one there +so the this is the Delta Vector do I + + align:start position:0% +so the this is the Delta Vector do I + + + align:start position:0% +so the this is the Delta Vector do I +need well you can see that it's it's the + + align:start position:0% +need well you can see that it's it's the + + + align:start position:0% +need well you can see that it's it's the +delta the vector is now going to be the + + align:start position:0% +delta the vector is now going to be the + + + align:start position:0% +delta the vector is now going to be the +the vector of all zeros and it's got a + + align:start position:0% +the vector of all zeros and it's got a + + + align:start position:0% +the vector of all zeros and it's got a +one at the key at the impulse and and + + align:start position:0% +one at the key at the impulse and and + + + align:start position:0% +one at the key at the impulse and and +then zero so it's a discrete impulse + + align:start position:0% +then zero so it's a discrete impulse + + + align:start position:0% +then zero so it's a discrete impulse +that would be a better word discrete + + align:start position:0% +that would be a better word discrete + + + align:start position:0% +that would be a better word discrete +impulse impulse at zero okay yeah so + + align:start position:0% +impulse impulse at zero okay yeah so + + + align:start position:0% +impulse impulse at zero okay yeah so +let's let's stay with an Impulse at zero + + align:start position:0% +let's let's stay with an Impulse at zero + + + align:start position:0% +let's let's stay with an Impulse at zero +all right what is + + align:start position:0% +all right what is + + + align:start position:0% +all right what is +the what's the next guy what's my next + + align:start position:0% + + + + align:start position:0% + +picture again let me put put in + + align:start position:0% +picture again let me put put in + + + align:start position:0% +picture again let me put put in +zero one two 3 onwards okay minus one so + + align:start position:0% +zero one two 3 onwards okay minus one so + + + align:start position:0% +zero one two 3 onwards okay minus one so +on um what do I want to do now what do I + + align:start position:0% +on um what do I want to do now what do I + + + align:start position:0% +on um what do I want to do now what do I +draw a second I always look over here + + align:start position:0% +draw a second I always look over here + + + align:start position:0% +draw a second I always look over here +what did I draw a second over + + align:start position:0% +what did I draw a second over + + + align:start position:0% +what did I draw a second over +here + + align:start position:0% +here + + + align:start position:0% +here +the step now what what why did I draw a + + align:start position:0% +the step now what what why did I draw a + + + align:start position:0% +the step now what what why did I draw a +step + + align:start position:0% +step + + + align:start position:0% +step +function what how did I get from here to + + align:start position:0% +function what how did I get from here to + + + align:start position:0% +function what how did I get from here to +here I integrated I took the integral + + align:start position:0% +here I integrated I took the integral + + + align:start position:0% +here I integrated I took the integral +okay so how will I get from here to this + + align:start position:0% +okay so how will I get from here to this + + + align:start position:0% +okay so how will I get from here to this +picture I don't integrate + + align:start position:0% +picture I don't integrate + + + align:start position:0% +picture I don't integrate +I add sum okay so coming along from the + + align:start position:0% +I add sum okay so coming along from the + + + align:start position:0% +I add sum okay so coming along from the +left all these all along here this sum + + align:start position:0% +left all these all along here this sum + + + align:start position:0% +left all these all along here this sum +is all zero because it was always zero + + align:start position:0% +is all zero because it was always zero + + + align:start position:0% +is all zero because it was always zero +so it's z0 Z + + align:start position:0% +so it's z0 Z + + + align:start position:0% +so it's z0 Z +zero and then oops wait a minute it's is + + align:start position:0% +zero and then oops wait a minute it's is + + + align:start position:0% +zero and then oops wait a minute it's is +it a one + + align:start position:0% +it a one + + + align:start position:0% +it a one +there yeah I think it must be so here it + + align:start position:0% +there yeah I think it must be so here it + + + align:start position:0% +there yeah I think it must be so here it +wasn't a zero + + align:start position:0% +wasn't a zero + + + align:start position:0% +wasn't a zero +wrong here it's a one and what is it + + align:start position:0% +wrong here it's a one and what is it + + + align:start position:0% +wrong here it's a one and what is it +next what's next to it one because I'm + + align:start position:0% +next what's next to it one because I'm + + + align:start position:0% +next what's next to it one because I'm +I'm adding more and more zeros but I + + align:start position:0% +I'm adding more and more zeros but I + + + align:start position:0% +I'm adding more and more zeros but I +have that one now okay a + + align:start position:0% +have that one now okay a + + + align:start position:0% +have that one now okay a +discrete step it's a discrete step zeros + + align:start position:0% +discrete step it's a discrete step zeros + + + align:start position:0% +discrete step it's a discrete step zeros +and then ones okay now comes the SE so + + align:start position:0% +and then ones okay now comes the SE so + + + align:start position:0% +and then ones okay now comes the SE so +what am I going to call that well a uh + + align:start position:0% +what am I going to call that well a uh + + + align:start position:0% +what am I going to call that well a uh +no a step right it'll be a step function + + align:start position:0% +no a step right it'll be a step function + + + align:start position:0% +no a step right it'll be a step function +step + + align:start position:0% +step + + + align:start position:0% +step +vector and the oh yeah if the sums of + + align:start position:0% +vector and the oh yeah if the sums of + + + align:start position:0% +vector and the oh yeah if the sums of +the Delta Vector gave me the step Vector + + align:start position:0% +the Delta Vector gave me the step Vector + + + align:start position:0% +the Delta Vector gave me the step Vector +how do I go the other + + align:start position:0% +how do I go the other + + + align:start position:0% +how do I go the other +way the what do I do with the step + + align:start position:0% +way the what do I do with the step + + + align:start position:0% +way the what do I do with the step +Vector to get back to the Delta + + align:start position:0% + + + + align:start position:0% + +Vector differences right sums in One + + align:start position:0% +Vector differences right sums in One + + + align:start position:0% +Vector differences right sums in One +Direction differences in the other so + + align:start position:0% +Direction differences in the other so + + + align:start position:0% +Direction differences in the other so +the D differences of the step Factor are + + align:start position:0% +the D differences of the step Factor are + + + align:start position:0% +the D differences of the step Factor are +the Delta Factor okay the step is the + + align:start position:0% +the Delta Factor okay the step is the + + + align:start position:0% +the Delta Factor okay the step is the +sum of the Deltas and the Delta is the + + align:start position:0% +sum of the Deltas and the Delta is the + + + align:start position:0% +sum of the Deltas and the Delta is the +differences of the step okay now for the + + align:start position:0% +differences of the step okay now for the + + + align:start position:0% +differences of the step okay now for the +crucial next guy what's it going to + + align:start position:0% +crucial next guy what's it going to + + + align:start position:0% +crucial next guy what's it going to +be I + + align:start position:0% +be I + + + align:start position:0% +be I +add wait a minute what's + + align:start position:0% + + + + align:start position:0% + +up I'm looking for that + + align:start position:0% + + + + align:start position:0% + +picture do I get it + + align:start position:0% + + + + align:start position:0% + +uh yeah I hope + + align:start position:0% +uh yeah I hope + + + align:start position:0% +uh yeah I hope +so or we oh look we ran out of time I + + align:start position:0% +so or we oh look we ran out of time I + + + align:start position:0% +so or we oh look we ran out of time I +don't have to do this but I will okay so + + align:start position:0% +don't have to do this but I will okay so + + + align:start position:0% +don't have to do this but I will okay so +uh so I'm get as I add I get zeros and + + align:start position:0% +uh so I'm get as I add I get zeros and + + + align:start position:0% +uh so I'm get as I add I get zeros and +then it's + + align:start position:0% +then it's + + + align:start position:0% +then it's +one and then I add on one more one + + align:start position:0% +one and then I add on one more one + + + align:start position:0% +one and then I add on one more one +look you see what's happening I I run + + align:start position:0% +look you see what's happening I I run + + + align:start position:0% +look you see what's happening I I run +along at zero but I I I'm going to look + + align:start position:0% +along at zero but I I I'm going to look + + + align:start position:0% +along at zero but I I I'm going to look +at the book to see + + align:start position:0% +at the book to see + + + align:start position:0% +at the book to see +um whether that jump should come here or + + align:start position:0% +um whether that jump should come here or + + + align:start position:0% +um whether that jump should come here or +here so I've got a little bit of this to + + align:start position:0% +here so I've got a little bit of this to + + + align:start position:0% +here so I've got a little bit of this to +finish next time and I'm open for any + + align:start position:0% +finish next time and I'm open for any + + + align:start position:0% +finish next time and I'm open for any +questions this afternoon okay thanks and + + align:start position:0% +questions this afternoon okay thanks and + + + align:start position:0% +questions this afternoon okay thanks and +sorry to keep you late \ No newline at end of file diff --git a/5s6rUYpVYjg.txt b/5s6rUYpVYjg.txt new file mode 100644 index 0000000000000000000000000000000000000000..1c0721598e9a7df694fa8473332b1d89d9ff2d2c --- /dev/null +++ b/5s6rUYpVYjg.txt @@ -0,0 +1,1947 @@ +align:start position:0% + +today we're going to finish our + + align:start position:0% +today we're going to finish our + + + align:start position:0% +today we're going to finish our +discussion of atoms and light in + + align:start position:0% +discussion of atoms and light in + + + align:start position:0% +discussion of atoms and light in +interaction and finally get some of + + align:start position:0% +interaction and finally get some of + + + align:start position:0% +interaction and finally get some of +those rates last time we reviewed the + + align:start position:0% +those rates last time we reviewed the + + + align:start position:0% +those rates last time we reviewed the +Einstein's argument I instead use his + + align:start position:0% +Einstein's argument I instead use his + + + align:start position:0% +Einstein's argument I instead use his +argument to discover spontaneous + + align:start position:0% +argument to discover spontaneous + + + align:start position:0% +argument to discover spontaneous +stimulated emission of radiation and how + + align:start position:0% +stimulated emission of radiation and how + + + align:start position:0% +stimulated emission of radiation and how +it accompanies the process of absorption + + align:start position:0% +it accompanies the process of absorption + + + align:start position:0% +it accompanies the process of absorption +all the time and there was also of + + align:start position:0% +all the time and there was also of + + + align:start position:0% +all the time and there was also of +course this process of spontaneous + + align:start position:0% +course this process of spontaneous + + + align:start position:0% +course this process of spontaneous +radiation that we found the formula for + + align:start position:0% +radiation that we found the formula for + + + align:start position:0% +radiation that we found the formula for +that transition rate in terms of the + + align:start position:0% +that transition rate in terms of the + + + align:start position:0% +that transition rate in terms of the +transition rate for stimulated radiation + + align:start position:0% +transition rate for stimulated radiation + + + align:start position:0% +transition rate for stimulated radiation +so let me review a couple of things that + + align:start position:0% +so let me review a couple of things that + + + align:start position:0% +so let me review a couple of things that +we had so we have an electric field that + + align:start position:0% +we had so we have an electric field that + + + align:start position:0% +we had so we have an electric field that +interacts with the atom there's a + + align:start position:0% +interacts with the atom there's a + + + align:start position:0% +interacts with the atom there's a +position vector that points to the + + align:start position:0% +position vector that points to the + + + align:start position:0% +position vector that points to the +charge Q and we have two levels level B + + align:start position:0% +charge Q and we have two levels level B + + + align:start position:0% +charge Q and we have two levels level B +with energy EB and level a with energy + + align:start position:0% +with energy EB and level a with energy + + + align:start position:0% +with energy EB and level a with energy +EA we introduce a dipole moment operator + + align:start position:0% +EA we introduce a dipole moment operator + + + align:start position:0% +EA we introduce a dipole moment operator +which was defined as Q times R and it's + + align:start position:0% +which was defined as Q times R and it's + + + align:start position:0% +which was defined as Q times R and it's +an operator because R is an operator the + + align:start position:0% +an operator because R is an operator the + + + align:start position:0% +an operator because R is an operator the +position is an operator in quantum + + align:start position:0% +position is an operator in quantum + + + align:start position:0% +position is an operator in quantum +mechanics so we observed and we've + + align:start position:0% +mechanics so we observed and we've + + + align:start position:0% +mechanics so we observed and we've +observed several times that the + + align:start position:0% +observed several times that the + + + align:start position:0% +observed several times that the +processes be going to a of stimulated + + align:start position:0% +processes be going to a of stimulated + + + align:start position:0% +processes be going to a of stimulated +emission and the process of a going to + + align:start position:0% +emission and the process of a going to + + + align:start position:0% +emission and the process of a going to +be of absorption are the same same to + + align:start position:0% +be of absorption are the same same to + + + align:start position:0% +be of absorption are the same same to +first order in perturbation theory and + + align:start position:0% +first order in perturbation theory and + + + align:start position:0% +first order in perturbation theory and +we wrote last time the formula for it + + align:start position:0% +we wrote last time the formula for it + + + align:start position:0% +we wrote last time the formula for it +using our general formula for harmonic + + align:start position:0% +using our general formula for harmonic + + + align:start position:0% +using our general formula for harmonic +transitions not Fermi's golden rule + + align:start position:0% +transitions not Fermi's golden rule + + + align:start position:0% +transitions not Fermi's golden rule +because + + align:start position:0% +because + + + align:start position:0% +because +this was a discrete transition + + align:start position:0% +this was a discrete transition + + + align:start position:0% +this was a discrete transition +apparently between these two levels so + + align:start position:0% +apparently between these two levels so + + + align:start position:0% +apparently between these two levels so +here is the formula let me remind you + + align:start position:0% +here is the formula let me remind you + + + align:start position:0% +here is the formula let me remind you +what it was there was an electric field + + align:start position:0% +what it was there was an electric field + + + align:start position:0% +what it was there was an electric field +was both of the farm to naught cosine + + align:start position:0% +was both of the farm to naught cosine + + + align:start position:0% +was both of the farm to naught cosine +Omega T times a vector n okay all our + + align:start position:0% +Omega T times a vector n okay all our + + + align:start position:0% +Omega T times a vector n okay all our +results from the discussion of light and + + align:start position:0% +results from the discussion of light and + + + align:start position:0% +results from the discussion of light and +atoms from previous lecture so here we + + align:start position:0% +atoms from previous lecture so here we + + + align:start position:0% +atoms from previous lecture so here we +go the transition probability as a + + align:start position:0% +go the transition probability as a + + + align:start position:0% +go the transition probability as a +function of time is given by this + + align:start position:0% +function of time is given by this + + + align:start position:0% +function of time is given by this +quantity in naught is half the peak + + align:start position:0% +quantity in naught is half the peak + + + align:start position:0% +quantity in naught is half the peak +amplitude of the electric field we + + align:start position:0% +amplitude of the electric field we + + + align:start position:0% +amplitude of the electric field we +always have this extra two here the a B + + align:start position:0% +always have this extra two here the a B + + + align:start position:0% +always have this extra two here the a B +is our the matrix elements of the + + align:start position:0% +is our the matrix elements of the + + + align:start position:0% +is our the matrix elements of the +operator D between the states here a and + + align:start position:0% +operator D between the states here a and + + + align:start position:0% +operator D between the states here a and +B so that's an inner product this is + + align:start position:0% +B so that's an inner product this is + + + align:start position:0% +B so that's an inner product this is +dotted with the vector n that refers to + + align:start position:0% +dotted with the vector n that refers to + + + align:start position:0% +dotted with the vector n that refers to +the polarization of the electric field + + align:start position:0% +the polarization of the electric field + + + align:start position:0% +the polarization of the electric field +that whole number is squared and then we + + align:start position:0% +that whole number is squared and then we + + + align:start position:0% +that whole number is squared and then we +have the sine squared over x squared + + align:start position:0% +have the sine squared over x squared + + + align:start position:0% +have the sine squared over x squared +function that we've usually had so this + + align:start position:0% +function that we've usually had so this + + + align:start position:0% +function that we've usually had so this +is our situation but what's gonna happen + + align:start position:0% +is our situation but what's gonna happen + + + align:start position:0% +is our situation but what's gonna happen +but we're interested and the situation + + align:start position:0% +but we're interested and the situation + + + align:start position:0% +but we're interested and the situation +that Einstein was considering was when + + align:start position:0% +that Einstein was considering was when + + + align:start position:0% +that Einstein was considering was when +you had a box + + align:start position:0% +you had a box + + + align:start position:0% +you had a box +you had thermal radiation and those + + align:start position:0% +you had thermal radiation and those + + + align:start position:0% +you had thermal radiation and those +atoms were there here we have a discrete + + align:start position:0% +atoms were there here we have a discrete + + + align:start position:0% +atoms were there here we have a discrete +process of transition from one state to + + align:start position:0% +process of transition from one state to + + + align:start position:0% +process of transition from one state to +another state neither one is a continuum + + align:start position:0% +another state neither one is a continuum + + + align:start position:0% +another state neither one is a continuum +when we had the ionization we were going + + align:start position:0% +when we had the ionization we were going + + + align:start position:0% +when we had the ionization we were going +from one state bound the continuum of + + align:start position:0% +from one state bound the continuum of + + + align:start position:0% +from one state bound the continuum of +flying electro + + align:start position:0% +flying electro + + + align:start position:0% +flying electro +and therefore a Fermi golden rule arose + + align:start position:0% +and therefore a Fermi golden rule arose + + + align:start position:0% +and therefore a Fermi golden rule arose +by integration here what are we to + + align:start position:0% +by integration here what are we to + + + align:start position:0% +by integration here what are we to +integrate well there is something to + + align:start position:0% +integrate well there is something to + + + align:start position:0% +integrate well there is something to +integrate the fact of the matter is that + + align:start position:0% +integrate the fact of the matter is that + + + align:start position:0% +integrate the fact of the matter is that +when you have this blood body radiation + + align:start position:0% +when you have this blood body radiation + + + align:start position:0% +when you have this blood body radiation +you will have a spectrum Omega of + + align:start position:0% +you will have a spectrum Omega of + + + align:start position:0% +you will have a spectrum Omega of +electric fields you don't just have one + + align:start position:0% +electric fields you don't just have one + + + align:start position:0% +electric fields you don't just have one +electric field at one specific frequency + + align:start position:0% +electric field at one specific frequency + + + align:start position:0% +electric field at one specific frequency +you will have many components of the + + align:start position:0% +you will have many components of the + + + align:start position:0% +you will have many components of the +electric field at different frequencies + + align:start position:0% +electric field at different frequencies + + + align:start position:0% +electric field at different frequencies +at different directions so in particular + + align:start position:0% +at different directions so in particular + + + align:start position:0% +at different directions so in particular +when you have blackbody radiation you + + align:start position:0% +when you have blackbody radiation you + + + align:start position:0% +when you have blackbody radiation you +will have in the spectrum here is omega + + align:start position:0% +will have in the spectrum here is omega + + + align:start position:0% +will have in the spectrum here is omega +be a that is the frequency for which the + + align:start position:0% +be a that is the frequency for which the + + + align:start position:0% +be a that is the frequency for which the +transitions tend to be more important + + align:start position:0% +transitions tend to be more important + + + align:start position:0% +transitions tend to be more important +remember when your Omega your frequency + + align:start position:0% +remember when your Omega your frequency + + + align:start position:0% +remember when your Omega your frequency +Omega is the frequency of the external + + align:start position:0% +Omega is the frequency of the external + + + align:start position:0% +Omega is the frequency of the external +light when your frequency Omega + + align:start position:0% +light when your frequency Omega + + + align:start position:0% +light when your frequency Omega +coincides with the Omega of this + + align:start position:0% +coincides with the Omega of this + + + align:start position:0% +coincides with the Omega of this +transition this stimulated emission or + + align:start position:0% +transition this stimulated emission or + + + align:start position:0% +transition this stimulated emission or +the absorption get enhanced so here is + + align:start position:0% +the absorption get enhanced so here is + + + align:start position:0% +the absorption get enhanced so here is +Omega be a that's one of the frequencies + + align:start position:0% +Omega be a that's one of the frequencies + + + align:start position:0% +Omega be a that's one of the frequencies +in the blackbody radiation but there are + + align:start position:0% +in the blackbody radiation but there are + + + align:start position:0% +in the blackbody radiation but there are +many many more nearby so and they are + + align:start position:0% +many many more nearby so and they are + + + align:start position:0% +many many more nearby so and they are +incoherent that is in the blackbody + + align:start position:0% +incoherent that is in the blackbody + + + align:start position:0% +incoherent that is in the blackbody +radiation + + align:start position:0% +radiation + + + align:start position:0% +radiation +each amplitude for a different frequency + + align:start position:0% +each amplitude for a different frequency + + + align:start position:0% +each amplitude for a different frequency +is independent of the other ones or like + + align:start position:0% +is independent of the other ones or like + + + align:start position:0% +is independent of the other ones or like +random so here is our sum therefore we + + align:start position:0% +random so here is our sum therefore we + + + align:start position:0% +random so here is our sum therefore we +must we know that when we have several + + align:start position:0% +must we know that when we have several + + + align:start position:0% +must we know that when we have several +inputs not just one electric field but + + align:start position:0% +inputs not just one electric field but + + + align:start position:0% +inputs not just one electric field but +many electric fields we will have to add + + align:start position:0% +many electric fields we will have to add + + + align:start position:0% +many electric fields we will have to add +the transition probability caused by the + + align:start position:0% +the transition probability caused by the + + + align:start position:0% +the transition probability caused by the +different electric fields and in this + + align:start position:0% +different electric fields and in this + + + align:start position:0% +different electric fields and in this +case we will have to sum the effects of + + align:start position:0% +case we will have to sum the effects of + + + align:start position:0% +case we will have to sum the effects of +the electric field squares of the main + + align:start position:0% +the electric field squares of the main + + + align:start position:0% +the electric field squares of the main +components of the blackbody radiation + + align:start position:0% +components of the blackbody radiation + + + align:start position:0% +components of the blackbody radiation +that lie near this Omega ba that is the + + align:start position:0% +that lie near this Omega ba that is the + + + align:start position:0% +that lie near this Omega ba that is the +one that would trigger a transition so + + align:start position:0% +one that would trigger a transition so + + + align:start position:0% +one that would trigger a transition so +this is how we're going to obtain + + align:start position:0% +this is how we're going to obtain + + + align:start position:0% +this is how we're going to obtain +something that will look like a Fermi + + align:start position:0% +something that will look like a Fermi + + + align:start position:0% +something that will look like a Fermi +golden rule as well here there's a + + align:start position:0% +golden rule as well here there's a + + + align:start position:0% +golden rule as well here there's a +transition the transition is between + + align:start position:0% +transition the transition is between + + + align:start position:0% +transition the transition is between +this great state but the trigger for the + + align:start position:0% +this great state but the trigger for the + + + align:start position:0% +this great state but the trigger for the +transition is a superposition of + + align:start position:0% +transition is a superposition of + + + align:start position:0% +transition is a superposition of +electromagnetic waves that we have to + + align:start position:0% +electromagnetic waves that we have to + + + align:start position:0% +electromagnetic waves that we have to +integrate over so one can say that the + + align:start position:0% +integrate over so one can say that the + + + align:start position:0% +integrate over so one can say that the +electric field electric field is a + + align:start position:0% +electric field electric field is a + + + align:start position:0% +electric field electric field is a +superposition of incoherent waves with + + align:start position:0% +superposition of incoherent waves with + + + align:start position:0% +superposition of incoherent waves with +different Omega + + align:start position:0% +different Omega + + + align:start position:0% +different Omega +eyes different frequencies different yz0 + + align:start position:0% +eyes different frequencies different yz0 + + + align:start position:0% +eyes different frequencies different yz0 +of omega i different amplitudes and + + align:start position:0% +of omega i different amplitudes and + + + align:start position:0% +of omega i different amplitudes and +different vectors unit vector so each + + align:start position:0% +different vectors unit vector so each + + + align:start position:0% +different vectors unit vector so each +mode of this blood body radiation has a + + align:start position:0% +mode of this blood body radiation has a + + + align:start position:0% +mode of this blood body radiation has a +different amplitude and a different + + align:start position:0% +different amplitude and a different + + + align:start position:0% +different amplitude and a different +Omega and a different polarization and + + align:start position:0% +Omega and a different polarization and + + + align:start position:0% +Omega and a different polarization and +we have to sum over those that are near + + align:start position:0% +we have to sum over those that are near + + + align:start position:0% +we have to sum over those that are near +Omega ba and we know the only over near + + align:start position:0% +Omega ba and we know the only over near + + + align:start position:0% +Omega ba and we know the only over near +ones because this function doesn't allow + + align:start position:0% +ones because this function doesn't allow + + + align:start position:0% +ones because this function doesn't allow +you to or it becomes too small when you + + align:start position:0% +you to or it becomes too small when you + + + align:start position:0% +you to or it becomes too small when you +get far away from that central frequency + + align:start position:0% +get far away from that central frequency + + + align:start position:0% +get far away from that central frequency +so as a first step I can rewrite this + + align:start position:0% +so as a first step I can rewrite this + + + align:start position:0% +so as a first step I can rewrite this +transition probability to make it a + + align:start position:0% +transition probability to make it a + + + align:start position:0% +transition probability to make it a +little clearer I would say here it is + + align:start position:0% +little clearer I would say here it is + + + align:start position:0% +little clearer I would say here it is +the + + align:start position:0% +the + + + align:start position:0% +the +transition probability for spontaneous + + align:start position:0% +transition probability for spontaneous + + + align:start position:0% +transition probability for spontaneous +emission of radiation associated to a + + align:start position:0% +emission of radiation associated to a + + + align:start position:0% +emission of radiation associated to a +particular mode of the radiation field + + align:start position:0% +particular mode of the radiation field + + + align:start position:0% +particular mode of the radiation field +would be given by four is zero of Omega + + align:start position:0% +would be given by four is zero of Omega + + + align:start position:0% +would be given by four is zero of Omega +I squared H squared + + align:start position:0% +I squared H squared + + + align:start position:0% +I squared H squared +Bab that is some matrix element in of + + align:start position:0% +Bab that is some matrix element in of + + + align:start position:0% +Bab that is some matrix element in of +the dipole operator in the atom that + + align:start position:0% +the dipole operator in the atom that + + + align:start position:0% +the dipole operator in the atom that +doesn't depend on anything having to do + + align:start position:0% +doesn't depend on anything having to do + + + align:start position:0% +doesn't depend on anything having to do +with the radiation M is possibly + + align:start position:0% +with the radiation M is possibly + + + align:start position:0% +with the radiation M is possibly +dependent on the radiation sine squared + + align:start position:0% +dependent on the radiation sine squared + + + align:start position:0% +dependent on the radiation sine squared +of 1/2 Omega B a minus Omega I the Omega + + align:start position:0% +of 1/2 Omega B a minus Omega I the Omega + + + align:start position:0% +of 1/2 Omega B a minus Omega I the Omega +I is the arming of the electric field so + + align:start position:0% + + + + align:start position:0% + +so I've put all these things to + + align:start position:0% +so I've put all these things to + + + align:start position:0% +so I've put all these things to +represent the contribution from the 8th + + align:start position:0% +represent the contribution from the 8th + + + align:start position:0% +represent the contribution from the 8th +mode of the radiation field to the + + align:start position:0% +mode of the radiation field to the + + + align:start position:0% +mode of the radiation field to the +transition amplitude that's what it does + + align:start position:0% +transition amplitude that's what it does + + + align:start position:0% +transition amplitude that's what it does +so you could say oh the eighth mode is + + align:start position:0% +so you could say oh the eighth mode is + + + align:start position:0% +so you could say oh the eighth mode is +one in which I would write to me not of + + align:start position:0% +one in which I would write to me not of + + + align:start position:0% +one in which I would write to me not of +I so here would be 2 e not of Omega I + + align:start position:0% +I so here would be 2 e not of Omega I + + + align:start position:0% +I so here would be 2 e not of Omega I +cosine of Omega I T times the vector n + + align:start position:0% +cosine of Omega I T times the vector n + + + align:start position:0% +cosine of Omega I T times the vector n +Omega I that's the ithe mode of the + + align:start position:0% +Omega I that's the ithe mode of the + + + align:start position:0% +Omega I that's the ithe mode of the +electric field and that ice mode of the + + align:start position:0% +electric field and that ice mode of the + + + align:start position:0% +electric field and that ice mode of the +electric field does this transition and + + align:start position:0% +electric field does this transition and + + + align:start position:0% +electric field does this transition and +we have to sum over all this modes that + + align:start position:0% +we have to sum over all this modes that + + + align:start position:0% +we have to sum over all this modes that +are nearby here ok this is a low non + + align:start position:0% +are nearby here ok this is a low non + + + align:start position:0% +are nearby here ok this is a low non +trivial things that we have to do now + + align:start position:0% +trivial things that we have to do now + + + align:start position:0% +trivial things that we have to do now +but the way to think about it is that + + align:start position:0% +but the way to think about it is that + + + align:start position:0% +but the way to think about it is that +we've seen from the einstein arguments + + align:start position:0% +we've seen from the einstein arguments + + + align:start position:0% +we've seen from the einstein arguments +and + + align:start position:0% +and + + + align:start position:0% +and +there's a function U of Omega which is + + align:start position:0% +there's a function U of Omega which is + + + align:start position:0% +there's a function U of Omega which is +the energy density per unit frequency so + + align:start position:0% +the energy density per unit frequency so + + + align:start position:0% +the energy density per unit frequency so +that when you multiply by the Omega this + + align:start position:0% +that when you multiply by the Omega this + + + align:start position:0% +that when you multiply by the Omega this +is the energy density contained in the + + align:start position:0% +is the energy density contained in the + + + align:start position:0% +is the energy density contained in the +part of the spectrum with a range the + + align:start position:0% +part of the spectrum with a range the + + + align:start position:0% +part of the spectrum with a range the +Amida that's your energy density so + + align:start position:0% +Amida that's your energy density so + + + align:start position:0% +Amida that's your energy density so +that's an important quantity because it + + align:start position:0% +that's an important quantity because it + + + align:start position:0% +that's an important quantity because it +represents a number of photons and + + align:start position:0% +represents a number of photons and + + + align:start position:0% +represents a number of photons and +that's how Einstein argued that that + + align:start position:0% +that's how Einstein argued that that + + + align:start position:0% +that's how Einstein argued that that +defines or is a part of the ingredients + + align:start position:0% +defines or is a part of the ingredients + + + align:start position:0% +defines or is a part of the ingredients +of constructing the rate at which + + align:start position:0% +of constructing the rate at which + + + align:start position:0% +of constructing the rate at which +transitions will be happening so we have + + align:start position:0% +transitions will be happening so we have + + + align:start position:0% +transitions will be happening so we have +to relay this to energy so let's try to + + align:start position:0% +to relay this to energy so let's try to + + + align:start position:0% +to relay this to energy so let's try to +relate it to energy so we use things + + align:start position:0% +relate it to energy so we use things + + + align:start position:0% +relate it to energy so we use things +from electromagnetism some basic facts + + align:start position:0% +from electromagnetism some basic facts + + + align:start position:0% +from electromagnetism some basic facts +from electromagnetism if you have so + + align:start position:0% +from electromagnetism if you have so + + + align:start position:0% +from electromagnetism if you have so +I'll go here if you have a wave in + + align:start position:0% +I'll go here if you have a wave in + + + align:start position:0% +I'll go here if you have a wave in +general for a wave you have an e field + + align:start position:0% +general for a wave you have an e field + + + align:start position:0% +general for a wave you have an e field +and a B field and you have energies you + + align:start position:0% +and a B field and you have energies you + + + align:start position:0% +and a B field and you have energies you +electric a new magnetic these are energy + + align:start position:0% +electric a new magnetic these are energy + + + align:start position:0% +electric a new magnetic these are energy +densities and there's a simple formula + + align:start position:0% +densities and there's a simple formula + + + align:start position:0% +densities and there's a simple formula +for them the electric energy is equal to + + align:start position:0% +for them the electric energy is equal to + + + align:start position:0% +for them the electric energy is equal to +the magnitude of the electric field + + align:start position:0% +the magnitude of the electric field + + + align:start position:0% +the magnitude of the electric field +squared over 8 pi and in our case the + + align:start position:0% +squared over 8 pi and in our case the + + + align:start position:0% +squared over 8 pi and in our case the +magnitude of the electric field is the + + align:start position:0% +magnitude of the electric field is the + + + align:start position:0% +magnitude of the electric field is the +electric field in our convention is to e + + align:start position:0% +electric field in our convention is to e + + + align:start position:0% +electric field in our convention is to e +naught cosine Omega T so what do we get + + align:start position:0% +naught cosine Omega T so what do we get + + + align:start position:0% +naught cosine Omega T so what do we get +here for a naught squared cosine squared + + align:start position:0% +here for a naught squared cosine squared + + + align:start position:0% +here for a naught squared cosine squared +Omega T over 8 pi so this is 1 over 2 pi + + align:start position:0% +Omega T over 8 pi so this is 1 over 2 pi + + + align:start position:0% +Omega T over 8 pi so this is 1 over 2 pi +e naught squared cosine squared of Omega + + align:start position:0% +e naught squared cosine squared of Omega + + + align:start position:0% +e naught squared cosine squared of Omega +T + + align:start position:0% +T + + + align:start position:0% +T +but nobody really cares about the + + align:start position:0% +but nobody really cares about the + + + align:start position:0% +but nobody really cares about the +fluctuation of the energy you need the + + align:start position:0% +fluctuation of the energy you need the + + + align:start position:0% +fluctuation of the energy you need the +average energy at the volume so the time + + align:start position:0% +average energy at the volume so the time + + + align:start position:0% +average energy at the volume so the time +dependence must be averaged so from here + + align:start position:0% +dependence must be averaged so from here + + + align:start position:0% +dependence must be averaged so from here +the average over time of the electric + + align:start position:0% +the average over time of the electric + + + align:start position:0% +the average over time of the electric +field energy density is the average over + + align:start position:0% +field energy density is the average over + + + align:start position:0% +field energy density is the average over +time of closing squared which is one + + align:start position:0% +time of closing squared which is one + + + align:start position:0% +time of closing squared which is one +half so we have 1 over 4 pi is zero + + align:start position:0% +half so we have 1 over 4 pi is zero + + + align:start position:0% +half so we have 1 over 4 pi is zero +squared so that's the average electric + + align:start position:0% +squared so that's the average electric + + + align:start position:0% +squared so that's the average electric +field energy for a wave and that's the + + align:start position:0% +field energy for a wave and that's the + + + align:start position:0% +field energy for a wave and that's the +average over time but in a + + align:start position:0% +average over time but in a + + + align:start position:0% +average over time but in a +electromagnetic wave the average + + align:start position:0% +electromagnetic wave the average + + + align:start position:0% +electromagnetic wave the average +electric energy and the average magnetic + + align:start position:0% +electric energy and the average magnetic + + + align:start position:0% +electric energy and the average magnetic +energy are the same so you be or um + + align:start position:0% +energy are the same so you be or um + + + align:start position:0% +energy are the same so you be or um +magnetic is equal to UE the averages are + + align:start position:0% +magnetic is equal to UE the averages are + + + align:start position:0% +magnetic is equal to UE the averages are +identical and then of the total energy + + align:start position:0% +identical and then of the total energy + + + align:start position:0% +identical and then of the total energy +density therefore is perfect total you + + align:start position:0% +density therefore is perfect total you + + + align:start position:0% +density therefore is perfect total you +it's already average energy density + + align:start position:0% +it's already average energy density + + + align:start position:0% +it's already average energy density +would be u e+ u m which is 2 you eat and + + align:start position:0% +would be u e+ u m which is 2 you eat and + + + align:start position:0% +would be u e+ u m which is 2 you eat and +it's therefore 1 over 2 pi e naught + + align:start position:0% +it's therefore 1 over 2 pi e naught + + + align:start position:0% +it's therefore 1 over 2 pi e naught +squared so our end result is that the + + align:start position:0% +squared so our end result is that the + + + align:start position:0% +squared so our end result is that the +energy density u is 1 over 2 pi e naught + + align:start position:0% +energy density u is 1 over 2 pi e naught + + + align:start position:0% +energy density u is 1 over 2 pi e naught +squared ok usually thing here that is + + align:start position:0% +squared ok usually thing here that is + + + align:start position:0% +squared ok usually thing here that is +important is that there's lots of + + align:start position:0% +important is that there's lots of + + + align:start position:0% +important is that there's lots of +factors of 2 as factors of 2 in defining + + align:start position:0% +factors of 2 as factors of 2 in defining + + + align:start position:0% +factors of 2 as factors of 2 in defining +the energy density in our + + align:start position:0% +the energy density in our + + + align:start position:0% +the energy density in our +in overtime in adding electric and + + align:start position:0% +in overtime in adding electric and + + + align:start position:0% +in overtime in adding electric and +magnetic contributions of this is + + align:start position:0% +magnetic contributions of this is + + + align:start position:0% +magnetic contributions of this is +correct + + align:start position:0% +correct + + + align:start position:0% +correct +it's important to get those factors of 2 + + align:start position:0% +it's important to get those factors of 2 + + + align:start position:0% +it's important to get those factors of 2 +right otherwise your final formulas will + + align:start position:0% +right otherwise your final formulas will + + + align:start position:0% +right otherwise your final formulas will +be off so here is a the end result is a + + align:start position:0% +be off so here is a the end result is a + + + align:start position:0% +be off so here is a the end result is a +nice formula that rep allows you to + + align:start position:0% +nice formula that rep allows you to + + + align:start position:0% +nice formula that rep allows you to +rewrite the amplitude of your + + align:start position:0% +rewrite the amplitude of your + + + align:start position:0% +rewrite the amplitude of your +oscillation in terms of its contribution + + align:start position:0% +oscillation in terms of its contribution + + + align:start position:0% +oscillation in terms of its contribution +to the energy density so here it goes we + + align:start position:0% +to the energy density so here it goes we + + + align:start position:0% +to the energy density so here it goes we +can now think of this by saying if I + + align:start position:0% +can now think of this by saying if I + + + align:start position:0% +can now think of this by saying if I +have an electric field squared at some + + align:start position:0% +have an electric field squared at some + + + align:start position:0% +have an electric field squared at some +frequency well that's 2 pi times the + + align:start position:0% +frequency well that's 2 pi times the + + + align:start position:0% +frequency well that's 2 pi times the +energy density contributing at that + + align:start position:0% +energy density contributing at that + + + align:start position:0% +energy density contributing at that +frequency that's just the specialization + + align:start position:0% +frequency that's just the specialization + + + align:start position:0% +frequency that's just the specialization +of this to an arbitrary frequency and + + align:start position:0% +of this to an arbitrary frequency and + + + align:start position:0% +of this to an arbitrary frequency and +Omega I and an Omega I here so with this + + align:start position:0% + + + + align:start position:0% + +we can now rewrite this transition + + align:start position:0% +we can now rewrite this transition + + + align:start position:0% +we can now rewrite this transition +amplitude the transition rebel can be + + align:start position:0% +amplitude the transition rebel can be + + + align:start position:0% +amplitude the transition rebel can be +now expressed in terms of energy + + align:start position:0% +now expressed in terms of energy + + + align:start position:0% +now expressed in terms of energy +densities so what do we have we have P B + + align:start position:0% +densities so what do we have we have P B + + + align:start position:0% +densities so what do we have we have P B +to a of P I would be equal to for that + + align:start position:0% +to a of P I would be equal to for that + + + align:start position:0% +to a of P I would be equal to for that +for remains there and then instead of + + align:start position:0% +for remains there and then instead of + + + align:start position:0% +for remains there and then instead of +Enochs squared we put two pi u of Omega + + align:start position:0% +Enochs squared we put two pi u of Omega + + + align:start position:0% +Enochs squared we put two pi u of Omega +I over H squared and not much changes + + align:start position:0% +I over H squared and not much changes + + + align:start position:0% +I over H squared and not much changes +anymore VAB and Omega I squared sine + + align:start position:0% +anymore VAB and Omega I squared sine + + + align:start position:0% +anymore VAB and Omega I squared sine +squared of 1/2 Omega B a minus Omega I P + + align:start position:0% +squared of 1/2 Omega B a minus Omega I P + + + align:start position:0% +squared of 1/2 Omega B a minus Omega I P +over Omega B a minus Omega I squared \ No newline at end of file diff --git a/6PxncdxIXNE.txt b/6PxncdxIXNE.txt new file mode 100644 index 0000000000000000000000000000000000000000..f1a59441809cd7680765d17d1ad9aa527fe898c9 --- /dev/null +++ b/6PxncdxIXNE.txt @@ -0,0 +1,13996 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit mitop courseware at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu I.E when multiple uh + + align:start position:0% +ocw.mit.edu I.E when multiple uh + + + align:start position:0% +ocw.mit.edu I.E when multiple uh +lineages of beneficial uh mutants are + + align:start position:0% +lineages of beneficial uh mutants are + + + align:start position:0% +lineages of beneficial uh mutants are +kind of spreading in the population at + + align:start position:0% +kind of spreading in the population at + + + align:start position:0% +kind of spreading in the population at +the same time right so when these clones + + align:start position:0% +the same time right so when these clones + + + align:start position:0% +the same time right so when these clones +are somehow interfering with each other + + align:start position:0% +are somehow interfering with each other + + + align:start position:0% +are somehow interfering with each other +in the population you know how is it + + align:start position:0% +in the population you know how is it + + + align:start position:0% +in the population you know how is it +that that clonal interference effect + + align:start position:0% +that that clonal interference effect + + + align:start position:0% +that that clonal interference effect +kind of plays out in the context of + + align:start position:0% +kind of plays out in the context of + + + align:start position:0% +kind of plays out in the context of +these microbial asexual populations and + + align:start position:0% +these microbial asexual populations and + + + align:start position:0% +these microbial asexual populations and +in particular in this uh in this paper + + align:start position:0% +in particular in this uh in this paper + + + align:start position:0% +in particular in this uh in this paper +what they were trying to measure was the + + align:start position:0% +what they were trying to measure was the + + + align:start position:0% +what they were trying to measure was the +distribution of effects of beneficial + + align:start position:0% +distribution of effects of beneficial + + + align:start position:0% +distribution of effects of beneficial +mutations right so you put a population + + align:start position:0% +mutations right so you put a population + + + align:start position:0% +mutations right so you put a population +into some new environment there may be + + align:start position:0% +into some new environment there may be + + + align:start position:0% +into some new environment there may be +some beneficial mutations that are + + align:start position:0% +some beneficial mutations that are + + + align:start position:0% +some beneficial mutations that are +possible the question is what is the + + align:start position:0% +possible the question is what is the + + + align:start position:0% +possible the question is what is the +probability distribution of effects of + + align:start position:0% +probability distribution of effects of + + + align:start position:0% +probability distribution of effects of +those benef beneficial mutations and + + align:start position:0% +those benef beneficial mutations and + + + align:start position:0% +those benef beneficial mutations and +this is uh as you might imagine a very + + align:start position:0% +this is uh as you might imagine a very + + + align:start position:0% +this is uh as you might imagine a very +basic quantity that we'd like to + + align:start position:0% +basic quantity that we'd like to + + + align:start position:0% +basic quantity that we'd like to +understand uh just to understand how + + align:start position:0% +understand uh just to understand how + + + align:start position:0% +understand uh just to understand how +Evolution Works in sort of new + + align:start position:0% +Evolution Works in sort of new + + + align:start position:0% +Evolution Works in sort of new +environments but it's actually something + + align:start position:0% +environments but it's actually something + + + align:start position:0% +environments but it's actually something +that's rather difficult to measure and + + align:start position:0% +that's rather difficult to measure and + + + align:start position:0% +that's rather difficult to measure and +and it's uh what's interesting here is + + align:start position:0% +and it's uh what's interesting here is + + + align:start position:0% +and it's uh what's interesting here is +it's difficult to measure in in kind of + + align:start position:0% +it's difficult to measure in in kind of + + + align:start position:0% +it's difficult to measure in in kind of +for for maybe a surprising reason um but + + align:start position:0% +for for maybe a surprising reason um but + + + align:start position:0% +for for maybe a surprising reason um but +I think that this is a wonderful example + + align:start position:0% +I think that this is a wonderful example + + + align:start position:0% +I think that this is a wonderful example +of how you you know if life gives you + + align:start position:0% +of how you you know if life gives you + + + align:start position:0% +of how you you know if life gives you +lemons that you make lemonade is that is + + align:start position:0% +lemons that you make lemonade is that is + + + align:start position:0% +lemons that you make lemonade is that is +that the expression + + align:start position:0% +that the expression + + + align:start position:0% +that the expression +okay right so in this paper they set out + + align:start position:0% +okay right so in this paper they set out + + + align:start position:0% +okay right so in this paper they set out +to try and measure the distribution of + + align:start position:0% +to try and measure the distribution of + + + align:start position:0% +to try and measure the distribution of +effects of beneficial limitations they + + align:start position:0% +effects of beneficial limitations they + + + align:start position:0% +effects of beneficial limitations they +were + + align:start position:0% +were + + + align:start position:0% +were +unsuccessful right but they were + + align:start position:0% +unsuccessful right but they were + + + align:start position:0% +unsuccessful right but they were +unsuccessful for an interesting reason + + align:start position:0% +unsuccessful for an interesting reason + + + align:start position:0% +unsuccessful for an interesting reason +so then they were able to write but I + + align:start position:0% +so then they were able to write but I + + + align:start position:0% +so then they were able to write but I +think it's a very nice uh s + + align:start position:0% +think it's a very nice uh s + + + align:start position:0% +think it's a very nice uh s +okay um are there any questions about uh + + align:start position:0% +okay um are there any questions about uh + + + align:start position:0% +okay um are there any questions about uh +where we are or administrative things + + align:start position:0% +where we are or administrative things + + + align:start position:0% +where we are or administrative things +before we get + + align:start position:0% + + + + align:start position:0% + +going all right all right so just to + + align:start position:0% +going all right all right so just to + + + align:start position:0% +going all right all right so just to +recap where we were from from last time + + align:start position:0% +recap where we were from from last time + + + align:start position:0% +recap where we were from from last time +right we introduced this Moran model in + + align:start position:0% +right we introduced this Moran model in + + + align:start position:0% +right we introduced this Moran model in +which there's a fixed population size n + + align:start position:0% +which there's a fixed population size n + + + align:start position:0% +which there's a fixed population size n +right then each of these sort of uh + + align:start position:0% +right then each of these sort of uh + + + align:start position:0% +right then each of these sort of uh +Cycles what we do is we uh we choose one + + align:start position:0% +Cycles what we do is we uh we choose one + + + align:start position:0% +Cycles what we do is we uh we choose one +individual to uh to divide and we choose + + align:start position:0% +individual to uh to divide and we choose + + + align:start position:0% +individual to uh to divide and we choose +uh one individual to be replaced and we + + align:start position:0% +uh one individual to be replaced and we + + + align:start position:0% +uh one individual to be replaced and we +have the daughter say cell replace the + + align:start position:0% +have the daughter say cell replace the + + + align:start position:0% +have the daughter say cell replace the +um replace the the cell that was chosen + + align:start position:0% +um replace the the cell that was chosen + + + align:start position:0% +um replace the the cell that was chosen +for + + align:start position:0% +for + + + align:start position:0% +for +replacement right now in that model uh + + align:start position:0% +replacement right now in that model uh + + + align:start position:0% +replacement right now in that model uh +what we found was that there's some + + align:start position:0% +what we found was that there's some + + + align:start position:0% +what we found was that there's some +probability + + align:start position:0% +probability + + + align:start position:0% +probability +X1 for a new Mutant with relative inness + + align:start position:0% +X1 for a new Mutant with relative inness + + + align:start position:0% +X1 for a new Mutant with relative inness +R to actually fix in the + + align:start position:0% +R to actually fix in the + + + align:start position:0% +R to actually fix in the +population and this uh this is in the + + align:start position:0% +population and this uh this is in the + + + align:start position:0% +population and this uh this is in the +case of no clonal + + align:start position:0% +case of no clonal + + + align:start position:0% +case of no clonal +interference okay so CI will in general + + align:start position:0% +interference okay so CI will in general + + + align:start position:0% +interference okay so CI will in general +be clonal interference today right so + + align:start position:0% +be clonal interference today right so + + + align:start position:0% +be clonal interference today right so +this is this is uh if there's just this + + align:start position:0% +this is this is uh if there's just this + + + align:start position:0% +this is this is uh if there's just this +one mutation that we're considering then + + align:start position:0% +one mutation that we're considering then + + + align:start position:0% +one mutation that we're considering then +the the question of surviving stochastic + + align:start position:0% +the the question of surviving stochastic + + + align:start position:0% +the the question of surviving stochastic +Extinction kind of at the beginning is + + align:start position:0% +Extinction kind of at the beginning is + + + align:start position:0% +Extinction kind of at the beginning is +equivalent to the question of um being + + align:start position:0% +equivalent to the question of um being + + + align:start position:0% +equivalent to the question of um being +able to fix in the population for uh for + + align:start position:0% +able to fix in the population for uh for + + + align:start position:0% +able to fix in the population for uh for +certainly for for a beneficial mutation + + align:start position:0% +certainly for for a beneficial mutation + + + align:start position:0% +certainly for for a beneficial mutation +with r greater than one okay so what we + + align:start position:0% +with r greater than one okay so what we + + + align:start position:0% +with r greater than one okay so what we +want to do today to just start is to try + + align:start position:0% +want to do today to just start is to try + + + align:start position:0% +want to do today to just start is to try +to think about how we can use this model + + align:start position:0% +to think about how we can use this model + + + align:start position:0% +to think about how we can use this model +and and and this equation uh in order to + + align:start position:0% +and and and this equation uh in order to + + + align:start position:0% +and and and this equation uh in order to +understand the probability of uh of + + align:start position:0% +understand the probability of uh of + + + align:start position:0% +understand the probability of uh of +fixation when there's more than one + + align:start position:0% +fixation when there's more than one + + + align:start position:0% +fixation when there's more than one +mutant in the + + align:start position:0% + + + + align:start position:0% + +population right so here what we found + + align:start position:0% +population right so here what we found + + + align:start position:0% +population right so here what we found +is that this thing there are two uh two + + align:start position:0% +is that this thing there are two uh two + + + align:start position:0% +is that this thing there are two uh two +limits that we might want to keep track + + align:start position:0% +limits that we might want to keep track + + + align:start position:0% +limits that we might want to keep track +of right so this thing goes to 1/ n for + + align:start position:0% +of right so this thing goes to 1/ n for + + + align:start position:0% +of right so this thing goes to 1/ n for +neutral + + align:start position:0% + + + + align:start position:0% + +mutations and it goes to uh s uh for um + + align:start position:0% +mutations and it goes to uh s uh for um + + + align:start position:0% +mutations and it goes to uh s uh for um +for moderately beneficial mutations okay + + align:start position:0% +for moderately beneficial mutations okay + + + align:start position:0% +for moderately beneficial mutations okay +for um so s is defined as R minus one + + align:start position:0% +for um so s is defined as R minus one + + + align:start position:0% +for um so s is defined as R minus one +okay so this it's this for S kind of + + align:start position:0% +okay so this it's this for S kind of + + + align:start position:0% +okay so this it's this for S kind of +greater than zero but for uh and for S * + + align:start position:0% +greater than zero but for uh and for S * + + + align:start position:0% +greater than zero but for uh and for S * +n uh much larger than + + align:start position:0% + + + + align:start position:0% + +one + + align:start position:0% +one + + + align:start position:0% +one +okay so I guess this already says that s + + align:start position:0% +okay so I guess this already says that s + + + align:start position:0% +okay so I guess this already says that s +is greater than zero so we could ignore + + align:start position:0% +is greater than zero so we could ignore + + + align:start position:0% +is greater than zero so we could ignore +that okay are there any questions about + + align:start position:0% +that okay are there any questions about + + + align:start position:0% +that okay are there any questions about +uh about this before we get going + + align:start position:0% +uh about this before we get going + + + align:start position:0% +uh about this before we get going +to practice using + + align:start position:0% +to practice using + + + align:start position:0% +to practice using +it all right so I just wanted to have us + + align:start position:0% +it all right so I just wanted to have us + + + align:start position:0% +it all right so I just wanted to have us +consider a few two possible + + align:start position:0% +consider a few two possible + + + align:start position:0% +consider a few two possible +situations + + align:start position:0% +situations + + + align:start position:0% +situations +right all right population size 10 what + + align:start position:0% +right all right population size 10 what + + + align:start position:0% +right all right population size 10 what +we want to do is consider a situation + + align:start position:0% +we want to do is consider a situation + + + align:start position:0% +we want to do is consider a situation +where there are uh two + + align:start position:0% +where there are uh two + + + align:start position:0% +where there are uh two +mutants + + align:start position:0% +mutants + + + align:start position:0% +mutants +uh and we're going to call them A and B + + align:start position:0% +uh and we're going to call them A and B + + + align:start position:0% +uh and we're going to call them A and B +all right with uh relative Fitness R A + + align:start position:0% +all right with uh relative Fitness R A + + + align:start position:0% +all right with uh relative Fitness R A +1.01 and + + align:start position:0% +1.01 and + + + align:start position:0% +1.01 and +RB + + align:start position:0% +RB + + + align:start position:0% +RB +099 so a is a beneficial mutant and B is + + align:start position:0% +099 so a is a beneficial mutant and B is + + + align:start position:0% +099 so a is a beneficial mutant and B is +a delerious mutant right uh and in all + + align:start position:0% +a delerious mutant right uh and in all + + + align:start position:0% +a delerious mutant right uh and in all +these problems we're going to assume + + align:start position:0% +these problems we're going to assume + + + align:start position:0% +these problems we're going to assume +that the rest of the population has uh + + align:start position:0% +that the rest of the population has uh + + + align:start position:0% +that the rest of the population has uh +has Fitness one right so these fitnesses + + align:start position:0% +has Fitness one right so these fitnesses + + + align:start position:0% +has Fitness one right so these fitnesses +of A and B they're uh as compared to the + + align:start position:0% +of A and B they're uh as compared to the + + + align:start position:0% +of A and B they're uh as compared to the +rest of population so in this case there + + align:start position:0% +rest of population so in this case there + + + align:start position:0% +rest of population so in this case there +are eight other individuals with + + align:start position:0% +are eight other individuals with + + + align:start position:0% +are eight other individuals with +relative Fitness + + align:start position:0% +relative Fitness + + + align:start position:0% +relative Fitness +one and so uh the question is what is + + align:start position:0% +one and so uh the question is what is + + + align:start position:0% +one and so uh the question is what is +the probability that a + + align:start position:0% + + + + align:start position:0% + +fixes all right takes over the + + align:start position:0% +fixes all right takes over the + + + align:start position:0% +fixes all right takes over the +population reaches uh + + align:start position:0% +population reaches uh + + + align:start position:0% +population reaches uh +number of a individuals equal to 10 + + align:start position:0% +number of a individuals equal to 10 + + + align:start position:0% +number of a individuals equal to 10 +right at that stage we're not allowing + + align:start position:0% +right at that stage we're not allowing + + + align:start position:0% +right at that stage we're not allowing +for any new mutations here so then + + align:start position:0% +for any new mutations here so then + + + align:start position:0% +for any new mutations here so then +that's the end of the Dynamics + + align:start position:0% + + + + align:start position:0% + +yeah so you can start thinking about it + + align:start position:0% +yeah so you can start thinking about it + + + align:start position:0% +yeah so you can start thinking about it +and I will give some options + + align:start position:0% + + + + align:start position:0% + +here + + align:start position:0% + + + + align:start position:0% + +all right so this is in the Moran model + + align:start position:0% +all right so this is in the Moran model + + + align:start position:0% +all right so this is in the Moran model +what is the probability that a + + align:start position:0% + + + + align:start position:0% + +fixes I'll give you 20 seconds to think + + align:start position:0% +fixes I'll give you 20 seconds to think + + + align:start position:0% +fixes I'll give you 20 seconds to think +about + + align:start position:0% + + + + align:start position:0% + +it + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +all right do you need more + + align:start position:0% + + + + align:start position:0% + +time all right let's go ahead and P and + + align:start position:0% +time all right let's go ahead and P and + + + align:start position:0% +time all right let's go ahead and P and +see where we are ready 3 2 + + align:start position:0% + + + + align:start position:0% + + + align:start position:0% + + + align:start position:0% +all right we got some uh I'd say B's C's + + align:start position:0% +all right we got some uh I'd say B's C's + + + align:start position:0% +all right we got some uh I'd say B's C's +is kind of the dominant all right so + + align:start position:0% +is kind of the dominant all right so + + + align:start position:0% +is kind of the dominant all right so +there there's there's generally a + + align:start position:0% +there there's there's generally a + + + align:start position:0% +there there's there's generally a +disagreement uh between B and + + align:start position:0% + + + + align:start position:0% + +C interesting okay uh yeah I think that + + align:start position:0% +C interesting okay uh yeah I think that + + + align:start position:0% +C interesting okay uh yeah I think that +there's I mean it's almost 50/50 uh it + + align:start position:0% +there's I mean it's almost 50/50 uh it + + + align:start position:0% +there's I mean it's almost 50/50 uh it +is a bit splotchy somehow you may need + + align:start position:0% +is a bit splotchy somehow you may need + + + align:start position:0% +is a bit splotchy somehow you may need +to uh make some effort to find something + + align:start position:0% +to uh make some effort to find something + + + align:start position:0% +to uh make some effort to find something +that disagrees with you but please do so + + align:start position:0% +that disagrees with you but please do so + + + align:start position:0% +that disagrees with you but please do so +all right turn to a neighbor and try to + + align:start position:0% +all right turn to a neighbor and try to + + + align:start position:0% +all right turn to a neighbor and try to +convince them that you're + + align:start position:0% + + + + align:start position:0% + +50 something else yeah so yeah go + + align:start position:0% + + + + align:start position:0% + +ahead + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +that's + + align:start position:0% +that's + + + align:start position:0% +that's +[Music] + + align:start position:0% + + + + align:start position:0% + +let's let's go ahead and Recon and see + + align:start position:0% +let's let's go ahead and Recon and see + + + align:start position:0% +let's let's go ahead and Recon and see +if uh see if + + align:start position:0% +if uh see if + + + align:start position:0% +if uh see if +anybody ready three two + + align:start position:0% + + + + align:start position:0% + +one all right okay so I'd say that + + align:start position:0% +one all right okay so I'd say that + + + align:start position:0% +one all right okay so I'd say that +there's some migration towards C but + + align:start position:0% +there's some migration towards C but + + + align:start position:0% +there's some migration towards C but +it's not U not not all the way okay can + + align:start position:0% +it's not U not not all the way okay can + + + align:start position:0% +it's not U not not all the way okay can +um all right different uh different + + align:start position:0% +um all right different uh different + + + align:start position:0% +um all right different uh different +arguments and uh you you may want to D + + align:start position:0% +arguments and uh you you may want to D + + + align:start position:0% +arguments and uh you you may want to D +is the is the argument being made over + + align:start position:0% +is the is the argument being made over + + + align:start position:0% +is the is the argument being made over +here D so if there's one individual from + + align:start position:0% +here D so if there's one individual from + + + align:start position:0% +here D so if there's one individual from +a and one individual from B and + + align:start position:0% +a and one individual from B and + + + align:start position:0% +a and one individual from B and +basically the they're about the same + + align:start position:0% +basically the they're about the same + + + align:start position:0% +basically the they're about the same +Fitness then the probability that they + + align:start position:0% +Fitness then the probability that they + + + align:start position:0% +Fitness then the probability that they +should I guess take over is 50% that + + align:start position:0% +should I guess take over is 50% that + + + align:start position:0% +should I guess take over is 50% that +assumes that one of them will take over + + align:start position:0% +assumes that one of them will take over + + + align:start position:0% +assumes that one of them will take over +yeah is there any reason to assume that + + align:start position:0% +yeah is there any reason to assume that + + + align:start position:0% +yeah is there any reason to assume that +one of them should take + + align:start position:0% + + + + align:start position:0% + +over I think that uh we may agree that + + align:start position:0% +over I think that uh we may agree that + + + align:start position:0% +over I think that uh we may agree that +the probability that a fixes is going to + + align:start position:0% +the probability that a fixes is going to + + + align:start position:0% +the probability that a fixes is going to +be approximately equal to the + + align:start position:0% +be approximately equal to the + + + align:start position:0% +be approximately equal to the +probability that b fixes that's going to + + align:start position:0% +probability that b fixes that's going to + + + align:start position:0% +probability that b fixes that's going to +be a useful Insight but but it may be + + align:start position:0% +be a useful Insight but but it may be + + + align:start position:0% +be a useful Insight but but it may be +that both F exct right so we have to + + align:start position:0% +that both F exct right so we have to + + + align:start position:0% +that both F exct right so we have to +keep track of that so that's the + + align:start position:0% +keep track of that so that's the + + + align:start position:0% +keep track of that so that's the +argument for why it's not + + align:start position:0% + + + + align:start position:0% + +deep you're welcome anytime we try all + + align:start position:0% +deep you're welcome anytime we try all + + + align:start position:0% +deep you're welcome anytime we try all +right yeah so between B and C where uh + + align:start position:0% +right yeah so between B and C where uh + + + align:start position:0% +right yeah so between B and C where uh +how to how can we think about + + align:start position:0% + + + + align:start position:0% + +this you can tell once again what your + + align:start position:0% +this you can tell once again what your + + + align:start position:0% +this you can tell once again what your +neighbor said that's fine yes um uh well + + align:start position:0% +neighbor said that's fine yes um uh well + + + align:start position:0% +neighbor said that's fine yes um uh well +my neigh as opposed to me made the made + + align:start position:0% +my neigh as opposed to me made the made + + + align:start position:0% +my neigh as opposed to me made the made +the um decision to try to think about it + + align:start position:0% +the um decision to try to think about it + + + align:start position:0% +the um decision to try to think about it +intuitively instead of trying to get + + align:start position:0% +intuitively instead of trying to get + + + align:start position:0% +intuitively instead of trying to get +through all the math yes always good to + + align:start position:0% +through all the math yes always good to + + + align:start position:0% +through all the math yes always good to +think about things intuitively rather + + align:start position:0% +think about things intuitively rather + + + align:start position:0% +think about things intuitively rather +you know + + align:start position:0% +you know + + + align:start position:0% +you know +that's so a is very slightly beneficial + + align:start position:0% +that's so a is very slightly beneficial + + + align:start position:0% +that's so a is very slightly beneficial +and so it it's just a little bit uh more + + align:start position:0% +and so it it's just a little bit uh more + + + align:start position:0% +and so it it's just a little bit uh more +likely to fix than a neutral commutation + + align:start position:0% +likely to fix than a neutral commutation + + + align:start position:0% +likely to fix than a neutral commutation +okay and how can we quantify this + + align:start position:0% +okay and how can we quantify this + + + align:start position:0% +okay and how can we quantify this +statement right that that I know I said + + align:start position:0% +statement right that that I know I said + + + align:start position:0% +statement right that that I know I said +that I didn't like math but you know + + align:start position:0% +that I didn't like math but you know + + + align:start position:0% +that I didn't like math but you know +every now and then we should look at it + + align:start position:0% +every now and then we should look at it + + + align:start position:0% +every now and then we should look at it +all right so yeah so the statement that + + align:start position:0% +all right so yeah so the statement that + + + align:start position:0% +all right so yeah so the statement that +a is + + align:start position:0% +a is + + + align:start position:0% +a is +approximately a neutral mutation how how + + align:start position:0% +approximately a neutral mutation how how + + + align:start position:0% +approximately a neutral mutation how how +is it that we can how do we know that I + + align:start position:0% +is it that we can how do we know that I + + + align:start position:0% +is it that we can how do we know that I +mean did we have a criteria for nearly + + align:start position:0% +mean did we have a criteria for nearly + + + align:start position:0% +mean did we have a criteria for nearly +neutral yes we have a criteria for + + align:start position:0% +neutral yes we have a criteria for + + + align:start position:0% +neutral yes we have a criteria for +nearly neutral right what what is that + + align:start position:0% +nearly neutral right what what is that + + + align:start position:0% +nearly neutral right what what is that +what does it mean to be nearly neutral + + align:start position:0% +what does it mean to be nearly neutral + + + align:start position:0% +what does it mean to be nearly neutral +uh the magnitude of s n is that's right + + align:start position:0% +uh the magnitude of s n is that's right + + + align:start position:0% +uh the magnitude of s n is that's right +s * n is much less than one means that + + align:start position:0% +s * n is much less than one means that + + + align:start position:0% +s * n is much less than one means that +it's nearly neutral and what that means + + align:start position:0% +it's nearly neutral and what that means + + + align:start position:0% +it's nearly neutral and what that means +is that the probability of fixing is the + + align:start position:0% +is that the probability of fixing is the + + + align:start position:0% +is that the probability of fixing is the +same as if it were a neutral + + align:start position:0% +same as if it were a neutral + + + align:start position:0% +same as if it were a neutral +mutation or approximately same and is + + align:start position:0% +mutation or approximately same and is + + + align:start position:0% +mutation or approximately same and is +that is that the case here yes yes s is + + align:start position:0% +that is that the case here yes yes s is + + + align:start position:0% +that is that the case here yes yes s is +0.01 so 1 100 and is 10 so s * n is + + align:start position:0% +0.01 so 1 100 and is 10 so s * n is + + + align:start position:0% +0.01 so 1 100 and is 10 so s * n is +equal to 0.1 + + align:start position:0% +equal to 0.1 + + + align:start position:0% +equal to 0.1 +right which means that both you know so + + align:start position:0% +right which means that both you know so + + + align:start position:0% +right which means that both you know so +a is maybe nearly neutral is B nearly + + align:start position:0% +a is maybe nearly neutral is B nearly + + + align:start position:0% +a is maybe nearly neutral is B nearly +neutral yes yes so both A and B are + + align:start position:0% +neutral yes yes so both A and B are + + + align:start position:0% +neutral yes yes so both A and B are +nearly neutral right one of them is an + + align:start position:0% +nearly neutral right one of them is an + + + align:start position:0% +nearly neutral right one of them is an +advantageous M one's aerious but in this + + align:start position:0% +advantageous M one's aerious but in this + + + align:start position:0% +advantageous M one's aerious but in this +population size they both behave as if + + align:start position:0% +population size they both behave as if + + + align:start position:0% +population size they both behave as if +they're nearly neutral right but in a + + align:start position:0% +they're nearly neutral right but in a + + + align:start position:0% +they're nearly neutral right but in a +larger population right so if we had a + + align:start position:0% +larger population right so if we had a + + + align:start position:0% +larger population right so if we had a +million individuals would these be + + align:start position:0% +million individuals would these be + + + align:start position:0% +million individuals would these be +neutral + + align:start position:0% +neutral + + + align:start position:0% +neutral +mutations no okay right so the question + + align:start position:0% +mutations no okay right so the question + + + align:start position:0% +mutations no okay right so the question +of whether something behaves as a + + align:start position:0% +of whether something behaves as a + + + align:start position:0% +of whether something behaves as a +neutral mutation depends upon the + + align:start position:0% +neutral mutation depends upon the + + + align:start position:0% +neutral mutation depends upon the +population size via this + + align:start position:0% + + + + align:start position:0% + +relation all right so then okay so + + align:start position:0% +relation all right so then okay so + + + align:start position:0% +relation all right so then okay so +that's that's and then and then how do + + align:start position:0% +that's that's and then and then how do + + + align:start position:0% +that's that's and then and then how do +we go from there well the the um the + + align:start position:0% +we go from there well the the um the + + + align:start position:0% +we go from there well the the um the +probability of a neutral mutation + + align:start position:0% +probability of a neutral mutation + + + align:start position:0% +probability of a neutral mutation +population that's right a neutral + + align:start position:0% +population that's right a neutral + + + align:start position:0% +population that's right a neutral +mutation will fix probability of one 10 + + align:start position:0% +mutation will fix probability of one 10 + + + align:start position:0% +mutation will fix probability of one 10 +right so indeed we're going to get this + + align:start position:0% +right so indeed we're going to get this + + + align:start position:0% +right so indeed we're going to get this +and and and you know and we need to + + align:start position:0% +and and and you know and we need to + + + align:start position:0% +and and and you know and we need to +highlight that we can you have to be + + align:start position:0% +highlight that we can you have to be + + + align:start position:0% +highlight that we can you have to be +very careful about just sticking things + + align:start position:0% +very careful about just sticking things + + + align:start position:0% +very careful about just sticking things +into formulas right so even though you + + align:start position:0% +into formulas right so even though you + + + align:start position:0% +into formulas right so even though you +know you may remember that the + + align:start position:0% +know you may remember that the + + + align:start position:0% +know you may remember that the +probability of a beneficial mutant + + align:start position:0% +probability of a beneficial mutant + + + align:start position:0% +probability of a beneficial mutant +fixing um in a population is is s but + + align:start position:0% +fixing um in a population is is s but + + + align:start position:0% +fixing um in a population is is s but +that's only for S * n being much larger + + align:start position:0% +that's only for S * n being much larger + + + align:start position:0% +that's only for S * n being much larger +than one and that's only when there's no + + align:start position:0% +than one and that's only when there's no + + + align:start position:0% +than one and that's only when there's no +clonal interference when there when + + align:start position:0% +clonal interference when there when + + + align:start position:0% +clonal interference when there when +you're when you don't have to compete + + align:start position:0% +you're when you don't have to compete + + + align:start position:0% +you're when you don't have to compete +with other beneficial mutants in the + + align:start position:0% +with other beneficial mutants in the + + + align:start position:0% +with other beneficial mutants in the +lineage right we're going to see an + + align:start position:0% +lineage right we're going to see an + + + align:start position:0% +lineage right we're going to see an +example of this in a moment okay but if + + align:start position:0% +example of this in a moment okay but if + + + align:start position:0% +example of this in a moment okay but if +you just have a single mutant in the + + align:start position:0% +you just have a single mutant in the + + + align:start position:0% +you just have a single mutant in the +population that's beneficial in the + + align:start position:0% +population that's beneficial in the + + + align:start position:0% +population that's beneficial in the +sense of it's not it's not neutral right + + align:start position:0% +sense of it's not it's not neutral right + + + align:start position:0% +sense of it's not it's not neutral right +then probably a fixation is s you know + + align:start position:0% +then probably a fixation is s you know + + + align:start position:0% +then probably a fixation is s you know +and of course this this is nonsensical + + align:start position:0% +and of course this this is nonsensical + + + align:start position:0% +and of course this this is nonsensical +right because you can't I it wouldn't + + align:start position:0% +right because you can't I it wouldn't + + + align:start position:0% +right because you can't I it wouldn't +make any it would certainly it would you + + align:start position:0% +make any it would certainly it would you + + + align:start position:0% +make any it would certainly it would you +know given that you say oh well if it + + align:start position:0% +know given that you say oh well if it + + + align:start position:0% +know given that you say oh well if it +were neutral it would fix with a + + align:start position:0% +were neutral it would fix with a + + + align:start position:0% +were neutral it would fix with a +probability of 10% and then you say oh + + align:start position:0% +probability of 10% and then you say oh + + + align:start position:0% +probability of 10% and then you say oh +but if it's advantageous mutant you know + + align:start position:0% +but if it's advantageous mutant you know + + + align:start position:0% +but if it's advantageous mutant you know +it can't fix with a probability less + + align:start position:0% +it can't fix with a probability less + + + align:start position:0% +it can't fix with a probability less +than that + + align:start position:0% +than that + + + align:start position:0% +than that +right so so this is NE neutral fixation + + align:start position:0% +right so so this is NE neutral fixation + + + align:start position:0% +right so so this is NE neutral fixation +probability is 10% are there any + + align:start position:0% +probability is 10% are there any + + + align:start position:0% +probability is 10% are there any +questions about that + + align:start position:0% + + + + align:start position:0% + +argument all right so let's consider a + + align:start position:0% +argument all right so let's consider a + + + align:start position:0% +argument all right so let's consider a +different + + align:start position:0% +different + + + align:start position:0% +different +problem all right all right so now we're + + align:start position:0% +problem all right all right so now we're + + + align:start position:0% +problem all right all right so now we're +going to consider a + + align:start position:0% +going to consider a + + + align:start position:0% +going to consider a +population + + align:start position:0% +population + + + align:start position:0% +population +larger so it's going to be the same + + align:start position:0% +larger so it's going to be the same + + + align:start position:0% +larger so it's going to be the same +situation where we have these two + + align:start position:0% +situation where we have these two + + + align:start position:0% +situation where we have these two +mutants present uh as as single single + + align:start position:0% + + + + align:start position:0% + +individuals so what we want to know now + + align:start position:0% +individuals so what we want to know now + + + align:start position:0% +individuals so what we want to know now +is the probability that b + + align:start position:0% + + + + align:start position:0% + +fixes once again you should start + + align:start position:0% +fixes once again you should start + + + align:start position:0% +fixes once again you should start +thinking about this while I type + + align:start position:0% +thinking about this while I type + + + align:start position:0% +thinking about this while I type +in okay oh but there was one other thing + + align:start position:0% +in okay oh but there was one other thing + + + align:start position:0% +in okay oh but there was one other thing +I wanted to say actually over here um if + + align:start position:0% +I wanted to say actually over here um if + + + align:start position:0% +I wanted to say actually over here um if +we modeled this these population + + align:start position:0% +we modeled this these population + + + align:start position:0% +we modeled this these population +Dynamics using differential + + align:start position:0% +Dynamics using differential + + + align:start position:0% +Dynamics using differential +equations right so instead of doing the + + align:start position:0% +equations right so instead of doing the + + + align:start position:0% +equations right so instead of doing the +Moran process where we have stochastic + + align:start position:0% +Moran process where we have stochastic + + + align:start position:0% +Moran process where we have stochastic +dynamics of of division replacement and + + align:start position:0% +dynamics of of division replacement and + + + align:start position:0% +dynamics of of division replacement and +so forth if you write down a + + align:start position:0% +so forth if you write down a + + + align:start position:0% +so forth if you write down a +differential equation describing this + + align:start position:0% +differential equation describing this + + + align:start position:0% +differential equation describing this +situation okay what is the probability + + align:start position:0% +situation okay what is the probability + + + align:start position:0% +situation okay what is the probability +that a fixes I'm going to give you five + + align:start position:0% +that a fixes I'm going to give you five + + + align:start position:0% +that a fixes I'm going to give you five +seconds one all right one + + align:start position:0% +seconds one all right one + + + align:start position:0% +seconds one all right one +okay okay so you don't get to vote + + align:start position:0% +okay okay so you don't get to vote + + + align:start position:0% +okay okay so you don't get to vote +indeed one + + align:start position:0% +indeed one + + + align:start position:0% +indeed one +okay right so if you had written down + + align:start position:0% +okay right so if you had written down + + + align:start position:0% +okay right so if you had written down +differential equation then there's no + + align:start position:0% +differential equation then there's no + + + align:start position:0% +differential equation then there's no +Randomness there whichever mutant has + + align:start position:0% +Randomness there whichever mutant has + + + align:start position:0% +Randomness there whichever mutant has +the largest Fitness will fix probability + + align:start position:0% +the largest Fitness will fix probability + + + align:start position:0% +the largest Fitness will fix probability +one + + align:start position:0% + + + + align:start position:0% + +okay okay probability D + + align:start position:0% + + + + align:start position:0% + +fixes + + align:start position:0% + + + + align:start position:0% + +so this you show me both + + align:start position:0% +so this you show me both + + + align:start position:0% +so this you show me both +cards yeah I'll give you uh I'll give + + align:start position:0% +cards yeah I'll give you uh I'll give + + + align:start position:0% +cards yeah I'll give you uh I'll give +you 20 30 seconds to + + align:start position:0% + + + + align:start position:0% + +take yes is there just one + + align:start position:0% + + + + align:start position:0% + +yes all right so this is kind that's why + + align:start position:0% +yes all right so this is kind that's why + + + align:start position:0% +yes all right so this is kind that's why +yeah so it's just the same thing so + + align:start position:0% +yeah so it's just the same thing so + + + align:start position:0% +yeah so it's just the same thing so +that's + + align:start position:0% +that's + + + align:start position:0% +that's +a yeah a single a mutant and a single B + + align:start position:0% +a yeah a single a mutant and a single B + + + align:start position:0% +a yeah a single a mutant and a single B +mutant yeah single + + align:start position:0% + + + + align:start position:0% + +a single B but you should know how to + + align:start position:0% +a single B but you should know how to + + + align:start position:0% +a single B but you should know how to +calculate these things if I tell you + + align:start position:0% +calculate these things if I tell you + + + align:start position:0% +calculate these things if I tell you +that they were other some other + + align:start position:0% + + + + align:start position:0% + +number + + align:start position:0% + + + + align:start position:0% + +all right do you need more + + align:start position:0% + + + + align:start position:0% + +time so in general if you don't look at + + align:start position:0% +time so in general if you don't look at + + + align:start position:0% +time so in general if you don't look at +me when I ask that question I'm going to + + align:start position:0% +me when I ask that question I'm going to + + + align:start position:0% +me when I ask that question I'm going to +take that as meaning that you're still + + align:start position:0% +take that as meaning that you're still + + + align:start position:0% +take that as meaning that you're still +thinking about it is that is that is + + align:start position:0% +thinking about it is that is that is + + + align:start position:0% +thinking about it is that is that is +that how I should interpret that + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +let's go ahead and vote just so that we + + align:start position:0% +let's go ahead and vote just so that we + + + align:start position:0% +let's go ahead and vote just so that we +can uh see where we are okay ready three + + align:start position:0% +can uh see where we are okay ready three + + + align:start position:0% +can uh see where we are okay ready three + + align:start position:0% + + + + align:start position:0% + +one oh right uh okay yeah we're we're + + align:start position:0% +one oh right uh okay yeah we're we're + + + align:start position:0% +one oh right uh okay yeah we're we're +all over the place that's great um + + align:start position:0% +all over the place that's great um + + + align:start position:0% +all over the place that's great um +because that that's that's that means + + align:start position:0% +because that that's that's that means + + + align:start position:0% +because that that's that's that means +your neighbor will either be able to + + align:start position:0% +your neighbor will either be able to + + + align:start position:0% +your neighbor will either be able to +help you or confuse you or do something + + align:start position:0% +help you or confuse you or do something + + + align:start position:0% +help you or confuse you or do something +all right so let's um let's go ahead all + + align:start position:0% +all right so let's um let's go ahead all + + + align:start position:0% +all right so let's um let's go ahead all +right so right there's a million yeah + + align:start position:0% +right so right there's a million yeah + + + align:start position:0% +right so right there's a million yeah +population size a million we have two + + align:start position:0% +population size a million we have two + + + align:start position:0% +population size a million we have two +mutants in the population one has + + align:start position:0% +mutants in the population one has + + + align:start position:0% +mutants in the population one has +relative Fitness to one has relative + + align:start position:0% +relative Fitness to one has relative + + + align:start position:0% +relative Fitness to one has relative +Fitness of um an advantage of of um + + align:start position:0% +Fitness of um an advantage of of um + + + align:start position:0% +Fitness of um an advantage of of um +1% okay uh one thing to be careful of + + align:start position:0% +1% okay uh one thing to be careful of + + + align:start position:0% +1% okay uh one thing to be careful of +here is uh + + align:start position:0% +here is uh + + + align:start position:0% +here is uh +the equation that we have for uh + + align:start position:0% +the equation that we have for uh + + + align:start position:0% +the equation that we have for uh +probability of fixation fixation + + align:start position:0% +probability of fixation fixation + + + align:start position:0% +probability of fixation fixation +here ah there's there's one more thing + + align:start position:0% +here ah there's there's one more thing + + + align:start position:0% +here ah there's there's one more thing +that I should say it's for um s well + + align:start position:0% +that I should say it's for um s well + + + align:start position:0% +that I should say it's for um s well +it's an S much less than + + align:start position:0% +it's an S much less than + + + align:start position:0% +it's an S much less than +one okay just + + align:start position:0% +one okay just + + + align:start position:0% +one okay just +for right so this is for a moderately + + align:start position:0% +for right so this is for a moderately + + + align:start position:0% +for right so this is for a moderately +beneficial mutation otherwise you have + + align:start position:0% +beneficial mutation otherwise you have + + + align:start position:0% +beneficial mutation otherwise you have +to use the full + + align:start position:0% +to use the full + + + align:start position:0% +to use the full +equation + + align:start position:0% +equation + + + align:start position:0% +equation +yes all right go ahead and turn to your + + align:start position:0% +yes all right go ahead and turn to your + + + align:start position:0% +yes all right go ahead and turn to your +neighbor and uh try to convince them + + align:start position:0% +neighbor and uh try to convince them + + + align:start position:0% +neighbor and uh try to convince them +that + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +you + + align:start position:0% + + + + align:start position:0% + +do + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +go RB + + align:start position:0% + + + + align:start position:0% + +Chang + + align:start position:0% + + + + align:start position:0% + +so everybody should be talking to + + align:start position:0% +so everybody should be talking to + + + align:start position:0% +so everybody should be talking to +somebody what do you + + align:start position:0% + + + + align:start position:0% + +think um well it's okay to not know but + + align:start position:0% +think um well it's okay to not know but + + + align:start position:0% +think um well it's okay to not know but +that's why you uh that's why you you can + + align:start position:0% +that's why you uh that's why you you can + + + align:start position:0% +that's why you uh that's why you you can +you uh you should either join them or um + + align:start position:0% +you uh you should either join them or um + + + align:start position:0% +you uh you should either join them or um +you know or if you look behind you + + align:start position:0% +you know or if you look behind you + + + align:start position:0% +you know or if you look behind you +there's someone else that looks very + + align:start position:0% + + + + align:start position:0% + +uh all right why don't let's okay let's + + align:start position:0% +uh all right why don't let's okay let's + + + align:start position:0% +uh all right why don't let's okay let's +what that my reasons are always that's + + align:start position:0% +what that my reasons are always that's + + + align:start position:0% +what that my reasons are always that's +always good reasons you it'll be they'll + + align:start position:0% +always good reasons you it'll be they'll + + + align:start position:0% +always good reasons you it'll be they'll +be + + align:start position:0% + + + + align:start position:0% + +educational all right let uh let's let's + + align:start position:0% +educational all right let uh let's let's + + + align:start position:0% +educational all right let uh let's let's +go ahead and reconvene okay I know that + + align:start position:0% +go ahead and reconvene okay I know that + + + align:start position:0% +go ahead and reconvene okay I know that +there there were a lot of different uh + + align:start position:0% +there there were a lot of different uh + + + align:start position:0% +there there were a lot of different uh +different guesses on this problem which + + align:start position:0% +different guesses on this problem which + + + align:start position:0% +different guesses on this problem which +means that it may be that the + + align:start position:0% +means that it may be that the + + + align:start position:0% +means that it may be that the +conversations were uh were scattered or + + align:start position:0% +conversations were uh were scattered or + + + align:start position:0% +conversations were uh were scattered or +difficult or it was difficult to uh + + align:start position:0% +difficult or it was difficult to uh + + + align:start position:0% +difficult or it was difficult to uh +converge but I I still let's see let's + + align:start position:0% +converge but I I still let's see let's + + + align:start position:0% +converge but I I still let's see let's +see if uh it made any difference ready + + align:start position:0% +see if uh it made any difference ready + + + align:start position:0% +see if uh it made any difference ready +three two + + align:start position:0% +three two + + + align:start position:0% +three two +one okay + + align:start position:0% +one okay + + + align:start position:0% +one okay +all right yeah so I'd say that the the + + align:start position:0% +all right yeah so I'd say that the the + + + align:start position:0% +all right yeah so I'd say that the the +conversations have helped uh but we but + + align:start position:0% +conversations have helped uh but we but + + + align:start position:0% +conversations have helped uh but we but +we're still you know a fair distribution + + align:start position:0% +we're still you know a fair distribution + + + align:start position:0% +we're still you know a fair distribution +between maybe a c and d still okay um + + align:start position:0% +between maybe a c and d still okay um + + + align:start position:0% +between maybe a c and d still okay um +but uh yeah somebody want to give an + + align:start position:0% +but uh yeah somebody want to give an + + + align:start position:0% +but uh yeah somebody want to give an +explanation for one of those three or + + align:start position:0% +explanation for one of those three or + + + align:start position:0% +explanation for one of those three or +something + + align:start position:0% +something + + + align:start position:0% +something +else yeah + + align:start position:0% + + + + align:start position:0% + +John right + + align:start position:0% +John right + + + align:start position:0% +John right +perfect okay I just want to make sure + + align:start position:0% +perfect okay I just want to make sure + + + align:start position:0% +perfect okay I just want to make sure +that we all agree on this logic all + + align:start position:0% +that we all agree on this logic all + + + align:start position:0% +that we all agree on this logic all +right so if the only thing we had was + + align:start position:0% +right so if the only thing we had was + + + align:start position:0% +right so if the only thing we had was +mutation B yeah then the probability + + align:start position:0% +mutation B yeah then the probability + + + align:start position:0% +mutation B yeah then the probability +fixation would be 1% because um in that + + align:start position:0% +fixation would be 1% because um in that + + + align:start position:0% +fixation would be 1% because um in that +case is this a nearly neutral mutation + + align:start position:0% +case is this a nearly neutral mutation + + + align:start position:0% +case is this a nearly neutral mutation +no right so that means that uh it's + + align:start position:0% +no right so that means that uh it's + + + align:start position:0% +no right so that means that uh it's +probability of fixation is going to be + + align:start position:0% +probability of fixation is going to be + + + align:start position:0% +probability of fixation is going to be +around s in this case one uh 01 okay but + + align:start position:0% +around s in this case one uh 01 okay but + + + align:start position:0% +around s in this case one uh 01 okay but +but now a is there so you like first you + + align:start position:0% +but now a is there so you like first you + + + align:start position:0% +but now a is there so you like first you +expect you expect the + + align:start position:0% +expect you expect the + + + align:start position:0% +expect you expect the +probility + + align:start position:0% + + + + align:start position:0% + +that's + + align:start position:0% +that's + + + align:start position:0% +that's +right + + align:start position:0% +right + + + align:start position:0% +right +exactly a yeah no no I mean it's uh uh + + align:start position:0% +exactly a yeah no no I mean it's uh uh + + + align:start position:0% +exactly a yeah no no I mean it's uh uh +no but that's that's that's precisely + + align:start position:0% +no but that's that's that's precisely + + + align:start position:0% +no but that's that's that's precisely +what's happening so the for B to fix it + + align:start position:0% +what's happening so the for B to fix it + + + align:start position:0% +what's happening so the for B to fix it +requires two things to happen right + + align:start position:0% +requires two things to happen right + + + align:start position:0% +requires two things to happen right +first B has to survive stochastic + + align:start position:0% + + + + align:start position:0% + +Extinction + + align:start position:0% +Extinction + + + align:start position:0% +Extinction +okay um + + align:start position:0% +okay um + + + align:start position:0% +okay um +you know and okay so we're going to + + align:start position:0% +you know and okay so we're going to + + + align:start position:0% +you know and okay so we're going to +multiply these probabilities um + + align:start position:0% +multiply these probabilities um + + + align:start position:0% +multiply these probabilities um +a doesn't + + align:start position:0% + + + + align:start position:0% + +survive we're going to discuss in a + + align:start position:0% +survive we're going to discuss in a + + + align:start position:0% +survive we're going to discuss in a +moment what this really means in terms + + align:start position:0% +moment what this really means in terms + + + align:start position:0% +moment what this really means in terms +of surviving stochast Extinction but the + + align:start position:0% +of surviving stochast Extinction but the + + + align:start position:0% +of surviving stochast Extinction but the +when a new mutation appears in the + + align:start position:0% +when a new mutation appears in the + + + align:start position:0% +when a new mutation appears in the +population it will either relatively + + align:start position:0% +population it will either relatively + + + align:start position:0% +population it will either relatively +quickly go extinct or it will relatively + + align:start position:0% +quickly go extinct or it will relatively + + + align:start position:0% +quickly go extinct or it will relatively +quickly become established that's what + + align:start position:0% +quickly become established that's what + + + align:start position:0% +quickly become established that's what +we call that what that means is that it + + align:start position:0% +we call that what that means is that it + + + align:start position:0% +we call that what that means is that it +will if it's a beneficial mutation it + + align:start position:0% +will if it's a beneficial mutation it + + + align:start position:0% +will if it's a beneficial mutation it +will take over unless it's Al by someone + + align:start position:0% +will take over unless it's Al by someone + + + align:start position:0% +will take over unless it's Al by someone +else okay so it has to be that b + + align:start position:0% +else okay so it has to be that b + + + align:start position:0% +else okay so it has to be that b +survives stochastic Extinction and a + + align:start position:0% +survives stochastic Extinction and a + + + align:start position:0% +survives stochastic Extinction and a +doesn't survive uh the this initial + + align:start position:0% +doesn't survive uh the this initial + + + align:start position:0% +doesn't survive uh the this initial +phase + + align:start position:0% +phase + + + align:start position:0% +phase +okay right and this thing all right so + + align:start position:0% +okay right and this thing all right so + + + align:start position:0% +okay right and this thing all right so +the pro so that means that the + + align:start position:0% +the pro so that means that the + + + align:start position:0% +the pro so that means that the +probability that b fixes is going to be + + align:start position:0% +probability that b fixes is going to be + + + align:start position:0% +probability that b fixes is going to be +well + + align:start position:0% +well + + + align:start position:0% +well +okay the probability that b survive + + align:start position:0% +okay the probability that b survive + + + align:start position:0% +okay the probability that b survive +stochastic Extinction is going to be + + align:start position:0% +stochastic Extinction is going to be + + + align:start position:0% +stochastic Extinction is going to be +1% right the probability that a survives + + align:start position:0% +1% right the probability that a survives + + + align:start position:0% +1% right the probability that a survives +is a half so the probability that it + + align:start position:0% +is a half so the probability that it + + + align:start position:0% +is a half so the probability that it +doesn't survive is also a half + + align:start position:0% + + + + align:start position:0% + +okay now the half just to remind + + align:start position:0% +okay now the half just to remind + + + align:start position:0% +okay now the half just to remind +ourselves comes from this thing X1 for a + + align:start position:0% +ourselves comes from this thing X1 for a + + + align:start position:0% +ourselves comes from this thing X1 for a +right there's this one + + align:start position:0% + + + + align:start position:0% + +over okay this + + align:start position:0% +over okay this + + + align:start position:0% +over okay this +thing is + + align:start position:0% +thing is + + + align:start position:0% +thing is +what right so right so this thing very + + align:start position:0% +what right so right so this thing very + + + align:start position:0% +what right so right so this thing very +quickly goes to zero right so this is 1 + + align:start position:0% +quickly goes to zero right so this is 1 + + + align:start position:0% +quickly goes to zero right so this is 1 +half to the millionth power okay so + + align:start position:0% +half to the millionth power okay so + + + align:start position:0% +half to the millionth power okay so +that's zero so we just get one minus a + + align:start position:0% +that's zero so we just get one minus a + + + align:start position:0% +that's zero so we just get one minus a +half + + align:start position:0% + + + + align:start position:0% + +okay yes what are we assuming it's to me + + align:start position:0% +okay yes what are we assuming it's to me + + + align:start position:0% +okay yes what are we assuming it's to me +this we're assuming they're completely + + align:start position:0% +this we're assuming they're completely + + + align:start position:0% +this we're assuming they're completely +independent can multip that's right + + align:start position:0% +independent can multip that's right + + + align:start position:0% +independent can multip that's right +together so yeah that's right uh and I + + align:start position:0% +together so yeah that's right uh and I + + + align:start position:0% +together so yeah that's right uh and I +would say that for from the standpoint + + align:start position:0% +would say that for from the standpoint + + + align:start position:0% +would say that for from the standpoint +of a population of a million these are + + align:start position:0% +of a population of a million these are + + + align:start position:0% +of a population of a million these are +totally non-interacting processes you + + align:start position:0% +totally non-interacting processes you + + + align:start position:0% +totally non-interacting processes you +know in in you know uh for all intents + + align:start position:0% +know in in you know uh for all intents + + + align:start position:0% +know in in you know uh for all intents +and purposes you know if you if you were + + align:start position:0% +and purposes you know if you if you were + + + align:start position:0% +and purposes you know if you if you were +down to a population size of 10 then you + + align:start position:0% +down to a population size of 10 then you + + + align:start position:0% +down to a population size of 10 then you +might have to worry that that um that + + align:start position:0% +might have to worry that that um that + + + align:start position:0% +might have to worry that that um that +they're going to interact more but you + + align:start position:0% +they're going to interact more but you + + + align:start position:0% +they're going to interact more but you +know in the in this process of um of you + + align:start position:0% +know in the in this process of um of you + + + align:start position:0% +know in the in this process of um of you +know this Moran process you know you + + align:start position:0% +know this Moran process you know you + + + align:start position:0% +know this Moran process you know you +have a million individuals if sure this + + align:start position:0% +have a million individuals if sure this + + + align:start position:0% +have a million individuals if sure this +is twice as likely to be chosen to + + align:start position:0% +is twice as likely to be chosen to + + + align:start position:0% +is twice as likely to be chosen to +divide as a normal cell but you're + + align:start position:0% +divide as a normal cell but you're + + + align:start position:0% +divide as a normal cell but you're +talking about a million cells in that + + align:start position:0% +talking about a million cells in that + + + align:start position:0% +talking about a million cells in that +population right so the the the + + align:start position:0% +population right so the the the + + + align:start position:0% +population right so the the the +correction to the things that you're + + align:start position:0% +correction to the things that you're + + + align:start position:0% +correction to the things that you're +worrying about is of order is a part in + + align:start position:0% +worrying about is of order is a part in + + + align:start position:0% +worrying about is of order is a part in +10 to the six so the thing the thing + + align:start position:0% +10 to the six so the thing the thing + + + align:start position:0% +10 to the six so the thing the thing +yeah um but if ra and RB were closer + + align:start position:0% +yeah um but if ra and RB were closer + + + align:start position:0% +yeah um but if ra and RB were closer +actually that correction no it's not + + align:start position:0% +actually that correction no it's not + + + align:start position:0% +actually that correction no it's not +about how how close ra and RB are to + + align:start position:0% +about how how close ra and RB are to + + + align:start position:0% +about how how close ra and RB are to +each other um you even if they had the + + align:start position:0% +each other um you even if they had the + + + align:start position:0% +each other um you even if they had the +exact + + align:start position:0% +exact + + + align:start position:0% +exact +same relative Fitness even if they were + + align:start position:0% +same relative Fitness even if they were + + + align:start position:0% +same relative Fitness even if they were +both two or both 1.01 then they would + + align:start position:0% +both two or both 1.01 then they would + + + align:start position:0% +both two or both 1.01 then they would +still be non-interacting that's just + + align:start position:0% +still be non-interacting that's just + + + align:start position:0% +still be non-interacting that's just +because they're in this sea of + + align:start position:0% +because they're in this sea of + + + align:start position:0% +because they're in this sea of +individuals but the thing that I'm + + align:start position:0% +individuals but the thing that I'm + + + align:start position:0% +individuals but the thing that I'm +worried about is for example ra could + + align:start position:0% +worried about is for example ra could + + + align:start position:0% +worried about is for example ra could +take over quickly and then RB take right + + align:start position:0% +take over quickly and then RB take right + + + align:start position:0% +take over quickly and then RB take right +and that okay uh would not be right + + align:start position:0% +and that okay uh would not be right + + + align:start position:0% +and that okay uh would not be right +okay so um and that's not reasonable + + align:start position:0% +okay so um and that's not reasonable + + + align:start position:0% +okay so um and that's not reasonable +this takes over RB the effective RB + + align:start position:0% +this takes over RB the effective RB + + + align:start position:0% +this takes over RB the effective RB +right okay so there is one problem right + + align:start position:0% +right okay so there is one problem right + + + align:start position:0% +right okay so there is one problem right +okay so I should be careful if if the + + align:start position:0% +okay so I should be careful if if the + + + align:start position:0% +okay so I should be careful if if the +two if the two mutants have exactly the + + align:start position:0% +two if the two mutants have exactly the + + + align:start position:0% +two if the two mutants have exactly the +same Fitness then if they both survive + + align:start position:0% +same Fitness then if they both survive + + + align:start position:0% +same Fitness then if they both survive +stas extinction they're going to then + + align:start position:0% +stas extinction they're going to then + + + align:start position:0% +stas extinction they're going to then +they then you can describe everything as + + align:start position:0% +they then you can describe everything as + + + align:start position:0% +they then you can describe everything as +a differential and this is this is the + + align:start position:0% +a differential and this is this is the + + + align:start position:0% +a differential and this is this is the +distinction between between this initial + + align:start position:0% +distinction between between this initial + + + align:start position:0% +distinction between between this initial +phase of trying to become established as + + align:start position:0% +phase of trying to become established as + + + align:start position:0% +phase of trying to become established as +compared to the later Dynamics and that + + align:start position:0% +compared to the later Dynamics and that + + + align:start position:0% +compared to the later Dynamics and that +uh the established means that if it's a + + align:start position:0% +uh the established means that if it's a + + + align:start position:0% +uh the established means that if it's a +beneficial mutation it will spread and + + align:start position:0% +beneficial mutation it will spread and + + + align:start position:0% +beneficial mutation it will spread and +basically determinist ically right so in + + align:start position:0% +basically determinist ically right so in + + + align:start position:0% +basically determinist ically right so in +that situation if you had two mutants + + align:start position:0% +that situation if you had two mutants + + + align:start position:0% +that situation if you had two mutants +both of relative Fitness uh 1.01 then + + align:start position:0% +both of relative Fitness uh 1.01 then + + + align:start position:0% +both of relative Fitness uh 1.01 then +they both would try to survive stas + + align:start position:0% +they both would try to survive stas + + + align:start position:0% +they both would try to survive stas +extinction and let's say that they both + + align:start position:0% +extinction and let's say that they both + + + align:start position:0% +extinction and let's say that they both +did then they would both uh spread in + + align:start position:0% +did then they would both uh spread in + + + align:start position:0% +did then they would both uh spread in +the population exponentially of course + + align:start position:0% +the population exponentially of course + + + align:start position:0% +the population exponentially of course +um given that the initial Dynamics are + + align:start position:0% +um given that the initial Dynamics are + + + align:start position:0% +um given that the initial Dynamics are +stochastic then um it would still be the + + align:start position:0% +stochastic then um it would still be the + + + align:start position:0% +stochastic then um it would still be the +case that one of them would just happen + + align:start position:0% +case that one of them would just happen + + + align:start position:0% +case that one of them would just happen +to be above the other one and then but + + align:start position:0% +to be above the other one and then but + + + align:start position:0% +to be above the other one and then but +then they would then they would grow + + align:start position:0% +then they would then they would grow + + + align:start position:0% +then they would then they would grow +exponentially together um that's a more + + align:start position:0% +exponentially together um that's a more + + + align:start position:0% +exponentially together um that's a more +complicated situation than what we're + + align:start position:0% +complicated situation than what we're + + + align:start position:0% +complicated situation than what we're +going to um discuss and that would + + align:start position:0% +going to um discuss and that would + + + align:start position:0% +going to um discuss and that would +actually be very rare right because each + + align:start position:0% +actually be very rare right because each + + + align:start position:0% +actually be very rare right because each +one of these mutants would only have a + + align:start position:0% +one of these mutants would only have a + + + align:start position:0% +one of these mutants would only have a +1% chance of surviving so only one and + + align:start position:0% +1% chance of surviving so only one and + + + align:start position:0% +1% chance of surviving so only one and +10 the four kind of times would you end + + align:start position:0% +10 the four kind of times would you end + + + align:start position:0% +10 the four kind of times would you end +up with both of these mutants surviving + + align:start position:0% +up with both of these mutants surviving + + + align:start position:0% +up with both of these mutants surviving +stochastic Extinction + + align:start position:0% + + + + align:start position:0% + +right any other questions about okay so + + align:start position:0% +right any other questions about okay so + + + align:start position:0% +right any other questions about okay so +I just want to be clear here so this is + + align:start position:0% +I just want to be clear here so this is + + + align:start position:0% +I just want to be clear here so this is +um you know this is when a is equal to + + align:start position:0% +um you know this is when a is equal to + + + align:start position:0% +um you know this is when a is equal to +you know the number of a individuals is + + align:start position:0% +you know the number of a individuals is + + + align:start position:0% +you know the number of a individuals is +one and number of B individuals equal to + + align:start position:0% +one and number of B individuals equal to + + + align:start position:0% +one and number of B individuals equal to +one + + align:start position:0% + + + + align:start position:0% + +right all there was a + + align:start position:0% + + + + align:start position:0% + +question what what if we started with a + + align:start position:0% +question what what if we started with a + + + align:start position:0% +question what what if we started with a +equal to 10 right so um let's say that + + align:start position:0% +equal to 10 right so um let's say that + + + align:start position:0% +equal to 10 right so um let's say that +yeah let's say actually let's say we + + align:start position:0% +yeah let's say actually let's say we + + + align:start position:0% +yeah let's say actually let's say we +start with 10 a and 10 B for + + align:start position:0% +start with 10 a and 10 B for + + + align:start position:0% +start with 10 a and 10 B for +example right so instead of starting + + align:start position:0% +example right so instead of starting + + + align:start position:0% +example right so instead of starting +with uh just one mutant a one mutant B + + align:start position:0% +with uh just one mutant a one mutant B + + + align:start position:0% +with uh just one mutant a one mutant B +now we have 10 of + + align:start position:0% +now we have 10 of + + + align:start position:0% +now we have 10 of +each right so we we're changing things + + align:start position:0% +each right so we we're changing things + + + align:start position:0% +each right so we we're changing things +symmetrically + + align:start position:0% +symmetrically + + + align:start position:0% +symmetrically +right what's going to be the probability + + align:start position:0% +right what's going to be the probability + + + align:start position:0% +right what's going to be the probability +that b + + align:start position:0% +that b + + + align:start position:0% +that b +fixes you know + + align:start position:0% +fixes you know + + + align:start position:0% +fixes you know +approximately all this is going to be a + + align:start position:0% +approximately all this is going to be a + + + align:start position:0% +approximately all this is going to be a +little funny somehow but okay + + align:start position:0% +little funny somehow but okay + + + align:start position:0% +little funny somehow but okay +well um just think about it for 15 + + align:start position:0% +well um just think about it for 15 + + + align:start position:0% +well um just think about it for 15 +seconds what's going to be the + + align:start position:0% +seconds what's going to be the + + + align:start position:0% +seconds what's going to be the +probability that b fixes if um in this + + align:start position:0% + + + + align:start position:0% + +case + + align:start position:0% + + + + align:start position:0% + +all right I'm worried you guys are not + + align:start position:0% +all right I'm worried you guys are not + + + align:start position:0% +all right I'm worried you guys are not +even + + align:start position:0% +even + + + align:start position:0% +even +[Laughter] + + align:start position:0% +[Laughter] + + + align:start position:0% +[Laughter] +trying sure yeah yeah yeah okay so what + + align:start position:0% +trying sure yeah yeah yeah okay so what + + + align:start position:0% +trying sure yeah yeah yeah okay so what +I want to know is so so we just did the + + align:start position:0% +I want to know is so so we just did the + + + align:start position:0% +I want to know is so so we just did the +problem when we had a single mutant a + + align:start position:0% +problem when we had a single mutant a + + + align:start position:0% +problem when we had a single mutant a +and a single mutant B and we found the + + align:start position:0% +and a single mutant B and we found the + + + align:start position:0% +and a single mutant B and we found the +probability that b fixes was + + align:start position:0% +probability that b fixes was + + + align:start position:0% +probability that b fixes was +0.5 now I want to know is does anything + + align:start position:0% +0.5 now I want to know is does anything + + + align:start position:0% +0.5 now I want to know is does anything +change if instead of having a single a + + align:start position:0% +change if instead of having a single a + + + align:start position:0% +change if instead of having a single a +and single B now what we have is 10 a 10 + + align:start position:0% +and single B now what we have is 10 a 10 + + + align:start position:0% +and single B now what we have is 10 a 10 +B and then the rest of them just being + + align:start position:0% +B and then the rest of them just being + + + align:start position:0% +B and then the rest of them just being +Rel of Fitness + + align:start position:0% + + + + align:start position:0% + +one all + + align:start position:0% +one all + + + align:start position:0% +one all +right so it's not fancy math but it + + align:start position:0% +right so it's not fancy math but it + + + align:start position:0% +right so it's not fancy math but it +still gets you a little confused + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +I just want to see where we are okay + + align:start position:0% +I just want to see where we are okay + + + align:start position:0% +I just want to see where we are okay +we'll use the same options here okay + + align:start position:0% +we'll use the same options here okay + + + align:start position:0% +we'll use the same options here okay +um you know whatever's + + align:start position:0% +um you know whatever's + + + align:start position:0% +um you know whatever's +closest and we can argue about what + + align:start position:0% +closest and we can argue about what + + + align:start position:0% +closest and we can argue about what +close means in a moment all right ready + + align:start position:0% +close means in a moment all right ready + + + align:start position:0% +close means in a moment all right ready +uh three two + + align:start position:0% +uh three two + + + align:start position:0% +uh three two +one okay I'd say yeah all right so it's + + align:start position:0% +one okay I'd say yeah all right so it's + + + align:start position:0% +one okay I'd say yeah all right so it's +kind of some A's and + + align:start position:0% +kind of some A's and + + + align:start position:0% +kind of some A's and +B's some e + + align:start position:0% + + + + align:start position:0% + +all right + + align:start position:0% +all right + + + align:start position:0% +all right +um okay well okay well we'll we'll talk + + align:start position:0% +um okay well okay well we'll we'll talk + + + align:start position:0% +um okay well okay well we'll we'll talk +about + + align:start position:0% +about + + + align:start position:0% +about +um all right I maybe I'll we'll jump + + align:start position:0% +um all right I maybe I'll we'll jump + + + align:start position:0% +um all right I maybe I'll we'll jump +ahead to the group discussion just + + align:start position:0% +ahead to the group discussion just + + + align:start position:0% +ahead to the group discussion just +because I don't want to spend too much + + align:start position:0% +because I don't want to spend too much + + + align:start position:0% +because I don't want to spend too much +time on this problem but these are these + + align:start position:0% +time on this problem but these are these + + + align:start position:0% +time on this problem but these are these +are the kinds of problems I think it's + + align:start position:0% +are the kinds of problems I think it's + + + align:start position:0% +are the kinds of problems I think it's +very important to to practice with + + align:start position:0% +very important to to practice with + + + align:start position:0% +very important to to practice with +because they just develop your intuition + + align:start position:0% +because they just develop your intuition + + + align:start position:0% +because they just develop your intuition +for the stochastic dynamics that occur + + align:start position:0% +for the stochastic dynamics that occur + + + align:start position:0% +for the stochastic dynamics that occur +in populations right um okay so let's + + align:start position:0% +in populations right um okay so let's + + + align:start position:0% +in populations right um okay so let's +let's you know it's G to be something + + align:start position:0% +let's you know it's G to be something + + + align:start position:0% +let's you know it's G to be something +like B you know that's not where I put + + align:start position:0% +like B you know that's not where I put + + + align:start position:0% +like B you know that's not where I put +why I put B in there because but okay + + align:start position:0% +why I put B in there because but okay + + + align:start position:0% +why I put B in there because but okay +but let's just see how it goes it's + + align:start position:0% +but let's just see how it goes it's + + + align:start position:0% +but let's just see how it goes it's +going to be all right and and the way to + + align:start position:0% +going to be all right and and the way to + + + align:start position:0% +going to be all right and and the way to +find the answer here is the same as what + + align:start position:0% +find the answer here is the same as what + + + align:start position:0% +find the answer here is the same as what +we did before except that now we have to + + align:start position:0% +we did before except that now we have to + + + align:start position:0% +we did before except that now we have to +think about these processes somewhat + + align:start position:0% +think about these processes somewhat + + + align:start position:0% +think about these processes somewhat +differently okay so first of all uh in + + align:start position:0% +differently okay so first of all uh in + + + align:start position:0% +differently okay so first of all uh in +order for B to fix it requires that b + + align:start position:0% +order for B to fix it requires that b + + + align:start position:0% +order for B to fix it requires that b +still B has to survive stochastic + + align:start position:0% +still B has to survive stochastic + + + align:start position:0% +still B has to survive stochastic +Extinction okay so we still have the the + + align:start position:0% +Extinction okay so we still have the the + + + align:start position:0% +Extinction okay so we still have the the +same 0.01 + + align:start position:0% +same 0.01 + + + align:start position:0% +same 0.01 +here okay but now we have to think about + + align:start position:0% +here okay but now we have to think about + + + align:start position:0% +here okay but now we have to think about +the probability that a doesn't survive + + align:start position:0% +the probability that a doesn't survive + + + align:start position:0% +the probability that a doesn't survive +okay and that's going to change now + + align:start position:0% +okay and that's going to change now + + + align:start position:0% +okay and that's going to change now +right oh I I I should be + + align:start position:0% +right oh I I I should be + + + align:start position:0% +right oh I I I should be +okay yeah okay no this is not okay I + + align:start position:0% +okay yeah okay no this is not okay I + + + align:start position:0% +okay yeah okay no this is not okay I +forgot that we had 10 here um + + align:start position:0% + + + + align:start position:0% + +it's and we could calculate what it is + + align:start position:0% +it's and we could calculate what it is + + + align:start position:0% +it's and we could calculate what it is +and actually maybe we should have okay + + align:start position:0% +and actually maybe we should have okay + + + align:start position:0% +and actually maybe we should have okay +let's just yeah no let's let's calculate + + align:start position:0% +let's just yeah no let's let's calculate + + + align:start position:0% +let's just yeah no let's let's calculate +that all right so this is X1 for + + align:start position:0% +that all right so this is X1 for + + + align:start position:0% +that all right so this is X1 for +b um we still have you know 1.01 to the + + align:start position:0% +b um we still have you know 1.01 to the + + + align:start position:0% +b um we still have you know 1.01 to the +million so this is we can still ignore + + align:start position:0% +million so this is we can still ignore + + + align:start position:0% +million so this is we can still ignore +this bottom part um right but what it's + + align:start position:0% +this bottom part um right but what it's + + + align:start position:0% +this bottom part um right but what it's +going to be is oh no but this is X10 of + + align:start position:0% +going to be is oh no but this is X10 of + + + align:start position:0% +going to be is oh no but this is X10 of +B right we have 10 individuals so this + + align:start position:0% +B right we have 10 individuals so this + + + align:start position:0% +B right we have 10 individuals so this +is 1 minus 1.01 to the 10th power + + align:start position:0% +is 1 minus 1.01 to the 10th power + + + align:start position:0% +is 1 minus 1.01 to the 10th power +yeah but we have interference right okay + + align:start position:0% +yeah but we have interference right okay + + + align:start position:0% +yeah but we have interference right okay +so this is this is this is as if this we + + align:start position:0% +so this is this is this is as if this we + + + align:start position:0% +so this is this is this is as if this we +right now what we're trying to + + align:start position:0% +right now what we're trying to + + + align:start position:0% +right now what we're trying to +understand is if only we had B you know + + align:start position:0% +understand is if only we had B you know + + + align:start position:0% +understand is if only we had B you know +this is the this is the + + align:start position:0% +this is the this is the + + + align:start position:0% +this is the this is the +probability that of we're trying to + + align:start position:0% +probability that of we're trying to + + + align:start position:0% +probability that of we're trying to +calculate this this part of it all right + + align:start position:0% +calculate this this part of it all right + + + align:start position:0% +calculate this this part of it all right +so if we ignore a what's probably B + + align:start position:0% +so if we ignore a what's probably B + + + align:start position:0% +so if we ignore a what's probably B +survive stochastic Extinction um right + + align:start position:0% +survive stochastic Extinction um right + + + align:start position:0% +survive stochastic Extinction um right +so this is + + align:start position:0% +so this is + + + align:start position:0% +so this is +uh oh this is fine okay so this is this + + align:start position:0% +uh oh this is fine okay so this is this + + + align:start position:0% +uh oh this is fine okay so this is this +is yeah so it's it's a modest it's a + + align:start position:0% +is yeah so it's it's a modest it's a + + + align:start position:0% +is yeah so it's it's a modest it's a +modest change right okay so this is + + align:start position:0% +modest change right okay so this is + + + align:start position:0% +modest change right okay so this is +because this is going to + + align:start position:0% +because this is going to + + + align:start position:0% +because this is going to +be one + + align:start position:0% +be one + + + align:start position:0% +be one +minus uh so this thing is + + align:start position:0% +minus uh so this thing is + + + align:start position:0% +minus uh so this thing is +around + + align:start position:0% +around + + + align:start position:0% +around +1.1 + + align:start position:0% +1.1 + + + align:start position:0% +1.1 +right + + align:start position:0% +right + + + align:start position:0% +right +because 1 + x to the + + align:start position:0% +because 1 + x to the + + + align:start position:0% +because 1 + x to the +N is around 1 + NX for NX much less than + + align:start position:0% +N is around 1 + NX for NX much less than + + + align:start position:0% +N is around 1 + NX for NX much less than +one right okay so this is + + align:start position:0% + + + + align:start position:0% + +1.19 okay so this + + align:start position:0% +1.19 okay so this + + + align:start position:0% +1.19 okay so this +is okay am I going correct okay okay + + align:start position:0% +is okay am I going correct okay okay + + + align:start position:0% +is okay am I going correct okay okay +okay so right right so we had to get rid + + align:start position:0% +okay so right right so we had to get rid + + + align:start position:0% +okay so right right so we had to get rid +of okay so this is around 0.1 + + align:start position:0% +of okay so this is around 0.1 + + + align:start position:0% +of okay so this is around 0.1 +right okay so indeed my you I'd + + align:start position:0% +right okay so indeed my you I'd + + + align:start position:0% +right okay so indeed my you I'd +forgotten that there was 10 + + align:start position:0% +forgotten that there was 10 + + + align:start position:0% +forgotten that there was 10 +okay so all right so so given that we + + align:start position:0% +okay so all right so so given that we + + + align:start position:0% +okay so all right so so given that we +have 10 of these B individuals starting + + align:start position:0% +have 10 of these B individuals starting + + + align:start position:0% +have 10 of these B individuals starting +right they may survive you know in the + + align:start position:0% +right they may survive you know in the + + + align:start position:0% +right they may survive you know in the +we're ignoring a right now just on their + + align:start position:0% +we're ignoring a right now just on their + + + align:start position:0% +we're ignoring a right now just on their +own Dynamics they they may survive or + + align:start position:0% +own Dynamics they they may survive or + + + align:start position:0% +own Dynamics they they may survive or +they may drift down to zero and go + + align:start position:0% +they may drift down to zero and go + + + align:start position:0% +they may drift down to zero and go +extinct right and indeed even starting + + align:start position:0% +extinct right and indeed even starting + + + align:start position:0% +extinct right and indeed even starting +with 10 individuals 10 B individuals you + + align:start position:0% +with 10 individuals 10 B individuals you + + + align:start position:0% +with 10 individuals 10 B individuals you +actually still expect them to go extinct + + align:start position:0% +actually still expect them to go extinct + + + align:start position:0% +actually still expect them to go extinct +okay this actually calculation is very + + align:start position:0% +okay this actually calculation is very + + + align:start position:0% +okay this actually calculation is very +relevant for what we're about to think + + align:start position:0% +relevant for what we're about to think + + + align:start position:0% +relevant for what we're about to think +about which is this question of what + + align:start position:0% +about which is this question of what + + + align:start position:0% +about which is this question of what +does it mean to be established in a + + align:start position:0% +does it mean to be established in a + + + align:start position:0% +does it mean to be established in a +population and already you can kind of + + align:start position:0% +population and already you can kind of + + + align:start position:0% +population and already you can kind of +see what it's going to mean right how + + align:start position:0% +see what it's going to mean right how + + + align:start position:0% +see what it's going to mean right how +big do you need to get in the population + + align:start position:0% +big do you need to get in the population + + + align:start position:0% +big do you need to get in the population +before you're likely to + + align:start position:0% + + + + align:start position:0% + +survive one/ s right this is because you + + align:start position:0% +survive one/ s right this is because you + + + align:start position:0% +survive one/ s right this is because you +can basically see how this is going to + + align:start position:0% +can basically see how this is going to + + + align:start position:0% +can basically see how this is going to +work out in this calculation that the + + align:start position:0% +work out in this calculation that the + + + align:start position:0% +work out in this calculation that the +number to be the number you have to get + + align:start position:0% +number to be the number you have to get + + + align:start position:0% +number to be the number you have to get +to to be established is around 1 over + + align:start position:0% +to to be established is around 1 over + + + align:start position:0% +to to be established is around 1 over +s okay so in this case you have to get + + align:start position:0% +s okay so in this case you have to get + + + align:start position:0% +s okay so in this case you have to get +to around 100 individuals before you are + + align:start position:0% +to around 100 individuals before you are + + + align:start position:0% +to around 100 individuals before you are +going to be more likely than not to + + align:start position:0% +going to be more likely than not to + + + align:start position:0% +going to be more likely than not to +survive okay + + align:start position:0% + + + + align:start position:0% + +okay let's see if we can figure out this + + align:start position:0% +okay let's see if we can figure out this + + + align:start position:0% +okay let's see if we can figure out this +problem all right so we had point one + + align:start position:0% +problem all right so we had point one + + + align:start position:0% +problem all right so we had point one +was the probability that b would survive + + align:start position:0% +was the probability that b would survive + + + align:start position:0% +was the probability that b would survive +stochastic Extinction okay but then in + + align:start position:0% +stochastic Extinction okay but then in + + + align:start position:0% +stochastic Extinction okay but then in +in order for B to fix it has to not only + + align:start position:0% +in order for B to fix it has to not only + + + align:start position:0% +in order for B to fix it has to not only +survive stochastic Extinction but also a + + align:start position:0% +survive stochastic Extinction but also a + + + align:start position:0% +survive stochastic Extinction but also a +has to not + + align:start position:0% +has to not + + + align:start position:0% +has to not +survive + + align:start position:0% +survive + + + align:start position:0% +survive +okay and uh we can figure out what that + + align:start position:0% +okay and uh we can figure out what that + + + align:start position:0% +okay and uh we can figure out what that +is going to be here right this this is + + align:start position:0% +is going to be here right this this is + + + align:start position:0% +is going to be here right this this is +that term right and then we uh we need + + align:start position:0% +that term right and then we uh we need + + + align:start position:0% +that term right and then we uh we need +another + + align:start position:0% +another + + + align:start position:0% +another +one all right so this is this is X of + + align:start position:0% +one all right so this is this is X of + + + align:start position:0% +one all right so this is this is X of +tan of a right and this is again going + + align:start position:0% +tan of a right and this is again going + + + align:start position:0% +tan of a right and this is again going +to be 1 minus 12 to the 10th + + align:start position:0% + + + + align:start position:0% + +power yeah right so it's always good to + + align:start position:0% +power yeah right so it's always good to + + + align:start position:0% +power yeah right so it's always good to +memorize a few of these things two to + + align:start position:0% +memorize a few of these things two to + + + align:start position:0% +memorize a few of these things two to +the 10 is approximately a + + align:start position:0% +the 10 is approximately a + + + align:start position:0% +the 10 is approximately a +thousand + + align:start position:0% + + + + align:start position:0% + +right but we want not this right so + + align:start position:0% +right but we want not this right so + + + align:start position:0% +right but we want not this right so +we're going to subtract this one away so + + align:start position:0% +we're going to subtract this one away so + + + align:start position:0% +we're going to subtract this one away so +we're going to get 10us + + align:start position:0% + + + + align:start position:0% + +3 do you guys see how that right so + + align:start position:0% +3 do you guys see how that right so + + + align:start position:0% +3 do you guys see how that right so +given that we start with 10 individuals + + align:start position:0% +given that we start with 10 individuals + + + align:start position:0% +given that we start with 10 individuals +of a with relative Fitness two then + + align:start position:0% +of a with relative Fitness two then + + + align:start position:0% +of a with relative Fitness two then +there's only a one in a thousand chance + + align:start position:0% +there's only a one in a thousand chance + + + align:start position:0% +there's only a one in a thousand chance +that that those a individuals are going + + align:start position:0% +that that those a individuals are going + + + align:start position:0% +that that those a individuals are going +to uh go + + align:start position:0% + + + + align:start position:0% + +extinct all right so the probability + + align:start position:0% +extinct all right so the probability + + + align:start position:0% +extinct all right so the probability +that b is going to fix in this situation + + align:start position:0% +that b is going to fix in this situation + + + align:start position:0% +that b is going to fix in this situation +is rather close to 10us 4 okay so I + + align:start position:0% +is rather close to 10us 4 okay so I + + + align:start position:0% +is rather close to 10us 4 okay so I +don't you know so it's somewhere in + + align:start position:0% +don't you know so it's somewhere in + + + align:start position:0% +don't you know so it's somewhere in +between there + + align:start position:0% + + + + align:start position:0% + +but + + align:start position:0% +but + + + align:start position:0% +but +are there any questions about how that + + align:start position:0% +are there any questions about how that + + + align:start position:0% +are there any questions about how that +came + + align:start position:0% + + + + align:start position:0% + +about I feel like there's a fair amount + + align:start position:0% +about I feel like there's a fair amount + + + align:start position:0% +about I feel like there's a fair amount +of + + align:start position:0% +of + + + align:start position:0% +of +unhappiness + + align:start position:0% + + + + align:start position:0% + +um so it could be the + + align:start position:0% +um so it could be the + + + align:start position:0% +um so it could be the +logic of this or it could be the + + align:start position:0% +logic of this or it could be the + + + align:start position:0% +logic of this or it could be the +calculation of one of the two terms or + + align:start position:0% +calculation of one of the two terms or + + + align:start position:0% +calculation of one of the two terms or +it could be something else + + align:start position:0% +it could be something else + + + align:start position:0% +it could be something else +yes + + align:start position:0% +yes + + + align:start position:0% +yes +sorry you + + align:start position:0% +sorry you + + + align:start position:0% +sorry you +get the probility of B surving again you + + align:start position:0% +get the probility of B surving again you + + + align:start position:0% +get the probility of B surving again you +you want to know this term or that term + + align:start position:0% +you want to know this term or that term + + + align:start position:0% +you want to know this term or that term +first term okay the first term right so + + align:start position:0% +first term okay the first term right so + + + align:start position:0% +first term okay the first term right so +the first term is just asking uh in if + + align:start position:0% +the first term is just asking uh in if + + + align:start position:0% +the first term is just asking uh in if +if there were no a okay what would be + + align:start position:0% +if there were no a okay what would be + + + align:start position:0% +if there were no a okay what would be +the probability that b would survive + + align:start position:0% +the probability that b would survive + + + align:start position:0% +the probability that b would survive +stochastic Extinction that's the same as + + align:start position:0% +stochastic Extinction that's the same as + + + align:start position:0% +stochastic Extinction that's the same as +the probability that it would um that it + + align:start position:0% +the probability that it would um that it + + + align:start position:0% +the probability that it would um that it +would fix because it's a beneficial + + align:start position:0% +would fix because it's a beneficial + + + align:start position:0% +would fix because it's a beneficial +mutation and if if B is the only thing + + align:start position:0% +mutation and if if B is the only thing + + + align:start position:0% +mutation and if if B is the only thing +right then so we use this + + align:start position:0% +right then so we use this + + + align:start position:0% +right then so we use this +okay yeah so we use we use this equation + + align:start position:0% +okay yeah so we use we use this equation + + + align:start position:0% +okay yeah so we use we use this equation +except this thing just goes to one so + + align:start position:0% +except this thing just goes to one so + + + align:start position:0% +except this thing just goes to one so +we're just left with this but we have to + + align:start position:0% +we're just left with this but we have to + + + align:start position:0% +we're just left with this but we have to +this equation is assuming that there's + + align:start position:0% +this equation is assuming that there's + + + align:start position:0% +this equation is assuming that there's +just one of the mutant individuals + + align:start position:0% +just one of the mutant individuals + + + align:start position:0% +just one of the mutant individuals +otherwise if we you know if you say x + + align:start position:0% +otherwise if we you know if you say x + + + align:start position:0% +otherwise if we you know if you say x +sub I then it's R to the I + + align:start position:0% + + + + align:start position:0% + +here all right so that was the equation + + align:start position:0% +here all right so that was the equation + + + align:start position:0% +here all right so that was the equation +that was derived in in chapter six of of + + align:start position:0% +that was derived in in chapter six of of + + + align:start position:0% +that was derived in in chapter six of of +evolutionary + + align:start position:0% +evolutionary + + + align:start position:0% +evolutionary +Dynamics + + align:start position:0% +Dynamics + + + align:start position:0% +Dynamics +okay but I think that that's not the + + align:start position:0% +okay but I think that that's not the + + + align:start position:0% +okay but I think that that's not the +only thing that people are unhappy about + + align:start position:0% +only thing that people are unhappy about + + + align:start position:0% +only thing that people are unhappy about +so + + align:start position:0% + + + + align:start position:0% + +please + + align:start position:0% +please + + + align:start position:0% +please +no yes question one why don't you need + + align:start position:0% +no yes question one why don't you need + + + align:start position:0% +no yes question one why don't you need +to take into account B doesn't survive + + align:start position:0% +to take into account B doesn't survive + + + align:start position:0% +to take into account B doesn't survive +that probability that doesn't survive + + align:start position:0% +that probability that doesn't survive + + + align:start position:0% +that probability that doesn't survive +for the question that's the right now + + align:start position:0% +for the question that's the right now + + + align:start position:0% +for the question that's the right now +guess for the near nearly + + align:start position:0% +guess for the near nearly + + + align:start position:0% +guess for the near nearly +neutral oh okay so this was the very + + align:start position:0% +neutral oh okay so this was the very + + + align:start position:0% +neutral oh okay so this was the very +first one that we did okay um all right + + align:start position:0% +first one that we did okay um all right + + + align:start position:0% +first one that we did okay um all right +so you want to know + + align:start position:0% + + + + align:start position:0% + +like why don't you need to take into + + align:start position:0% +like why don't you need to take into + + + align:start position:0% +like why don't you need to take into +account the that does survive all right + + align:start position:0% +account the that does survive all right + + + align:start position:0% +account the that does survive all right +so in in this problem it's just that + + align:start position:0% +so in in this problem it's just that + + + align:start position:0% +so in in this problem it's just that +they all behave as if they were just + + align:start position:0% +they all behave as if they were just + + + align:start position:0% +they all behave as if they were just +neutral so the probability of each of + + align:start position:0% +neutral so the probability of each of + + + align:start position:0% +neutral so the probability of each of +these 10 individuals fixing in the + + align:start position:0% +these 10 individuals fixing in the + + + align:start position:0% +these 10 individuals fixing in the +population is the same essentially right + + align:start position:0% +population is the same essentially right + + + align:start position:0% +population is the same essentially right +and so they each have a one and 10 + + align:start position:0% +and so they each have a one and 10 + + + align:start position:0% +and so they each have a one and 10 +probability of + + align:start position:0% +probability of + + + align:start position:0% +probability of +surviving and and in this case I would + + align:start position:0% +surviving and and in this case I would + + + align:start position:0% +surviving and and in this case I would +say that if if things are nearly neutral + + align:start position:0% +say that if if things are nearly neutral + + + align:start position:0% +say that if if things are nearly neutral +you don't talk about this idea of + + align:start position:0% +you don't talk about this idea of + + + align:start position:0% +you don't talk about this idea of +surviving stochastic extinction because + + align:start position:0% +surviving stochastic extinction because + + + align:start position:0% +surviving stochastic extinction because +it's all going to be it's you know you + + align:start position:0% +it's all going to be it's you know you + + + align:start position:0% +it's all going to be it's you know you +can't get big enough to the point where + + align:start position:0% +can't get big enough to the point where + + + align:start position:0% +can't get big enough to the point where +you will are guarant you know where + + align:start position:0% +you will are guarant you know where + + + align:start position:0% +you will are guarant you know where +you're really guaranteed to survive + + align:start position:0% +you're really guaranteed to survive + + + align:start position:0% +you're really guaranteed to survive +extinction because even if you've gone + + align:start position:0% +extinction because even if you've gone + + + align:start position:0% +extinction because even if you've gone +to occupy 75% of the + + align:start position:0% +to occupy 75% of the + + + align:start position:0% +to occupy 75% of the +population right what's your probability + + align:start position:0% +population right what's your probability + + + align:start position:0% +population right what's your probability +of fixing at that + + align:start position:0% +of fixing at that + + + align:start position:0% +of fixing at that +stage if you're nearly neutral and you + + align:start position:0% +stage if you're nearly neutral and you + + + align:start position:0% +stage if you're nearly neutral and you +get up to + + align:start position:0% +get up to + + + align:start position:0% +get up to +75% you have a 75% chance of fixing + + align:start position:0% +75% you have a 75% chance of fixing + + + align:start position:0% +75% you have a 75% chance of fixing +right so so there's no uh in the casee + + align:start position:0% +right so so there's no uh in the casee + + + align:start position:0% +right so so there's no uh in the casee +of neutral mutations uh there's no + + align:start position:0% +of neutral mutations uh there's no + + + align:start position:0% +of neutral mutations uh there's no +analogous idea of what it means to be um + + align:start position:0% +analogous idea of what it means to be um + + + align:start position:0% +analogous idea of what it means to be um +to be established because you could + + align:start position:0% +to be established because you could + + + align:start position:0% +to be established because you could +always just go back and go extinct with + + align:start position:0% +always just go back and go extinct with + + + align:start position:0% +always just go back and go extinct with +with finite + + align:start position:0% +with finite + + + align:start position:0% +with finite +probability + + align:start position:0% +probability + + + align:start position:0% +probability +okay okay + + align:start position:0% +okay okay + + + align:start position:0% +okay okay +right this + + align:start position:0% +right this + + + align:start position:0% +right this +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +question okay well you know it's looking + + align:start position:0% +question okay well you know it's looking + + + align:start position:0% +question okay well you know it's looking +more and more likely to show up on the + + align:start position:0% +more and more likely to show up on the + + + align:start position:0% +more and more likely to show up on the +midterm on in in two weeks all right so + + align:start position:0% +midterm on in in two weeks all right so + + + align:start position:0% +midterm on in in two weeks all right so +now is your opportunity to ask a + + align:start position:0% +now is your opportunity to ask a + + + align:start position:0% +now is your opportunity to ask a +question about it if + + align:start position:0% +question about it if + + + align:start position:0% +question about it if +um can you can you talk about and + + align:start position:0% +um can you can you talk about and + + + align:start position:0% +um can you can you talk about and +established how you got it what it yes + + align:start position:0% +established how you got it what it yes + + + align:start position:0% +established how you got it what it yes +okay this is a good question all right + + align:start position:0% +okay this is a good question all right + + + align:start position:0% +okay this is a good question all right +right so when we talk about a mutation + + align:start position:0% +right so when we talk about a mutation + + + align:start position:0% +right so when we talk about a mutation +becoming + + align:start position:0% +becoming + + + align:start position:0% +becoming +established that you know that's asking + + align:start position:0% + + + + align:start position:0% + +uh course we know that even a rather + + align:start position:0% +uh course we know that even a rather + + + align:start position:0% +uh course we know that even a rather +beneficial mutation say something that + + align:start position:0% +beneficial mutation say something that + + + align:start position:0% +beneficial mutation say something that +confers an advantage of a few percent + + align:start position:0% +confers an advantage of a few percent + + + align:start position:0% +confers an advantage of a few percent +will probably go extinct okay uh however + + align:start position:0% +will probably go extinct okay uh however + + + align:start position:0% +will probably go extinct okay uh however +if it gets up to be a large enough um + + align:start position:0% +if it gets up to be a large enough um + + + align:start position:0% +if it gets up to be a large enough um +fraction or number in the population + + align:start position:0% +fraction or number in the population + + + align:start position:0% +fraction or number in the population +then uh it should then the Dynamics are + + align:start position:0% +then uh it should then the Dynamics are + + + align:start position:0% +then uh it should then the Dynamics are +going to be well described by a + + align:start position:0% +going to be well described by a + + + align:start position:0% +going to be well described by a +differential equation where it won't go + + align:start position:0% +differential equation where it won't go + + + align:start position:0% +differential equation where it won't go +extinct so this is for um this is for um + + align:start position:0% +extinct so this is for um this is for um + + + align:start position:0% +extinct so this is for um this is for um +this is established mutation and this + + align:start position:0% +this is established mutation and this + + + align:start position:0% +this is established mutation and this +this again we we really talk about only + + align:start position:0% +this again we we really talk about only + + + align:start position:0% +this again we we really talk about only +for for beneficial mutations because + + align:start position:0% +for for beneficial mutations because + + + align:start position:0% +for for beneficial mutations because +other other mutations can't really get + + align:start position:0% +other other mutations can't really get + + + align:start position:0% +other other mutations can't really get +established they could still + + align:start position:0% +established they could still + + + align:start position:0% +established they could still +stochastically fix but it's stochastic + + align:start position:0% +stochastically fix but it's stochastic + + + align:start position:0% +stochastically fix but it's stochastic +up to the very + + align:start position:0% +up to the very + + + align:start position:0% +up to the very +end okay and right so the question is at + + align:start position:0% +end okay and right so the question is at + + + align:start position:0% +end okay and right so the question is at +what number + + align:start position:0% +what number + + + align:start position:0% +what number +in the population do you have to get + + align:start position:0% +in the population do you have to get + + + align:start position:0% +in the population do you have to get +before you are expected to take over the + + align:start position:0% +before you are expected to take over the + + + align:start position:0% +before you are expected to take over the +population okay assuming that other + + align:start position:0% +population okay assuming that other + + + align:start position:0% +population okay assuming that other +other New Mutants don't arise + + align:start position:0% +other New Mutants don't arise + + + align:start position:0% +other New Mutants don't arise +okay and let me + + align:start position:0% +okay and let me + + + align:start position:0% +okay and let me +um right so this we can ask that + + align:start position:0% +um right so this we can ask that + + + align:start position:0% +um right so this we can ask that +corresponds to asking okay what this is + + align:start position:0% +corresponds to asking okay what this is + + + align:start position:0% +corresponds to asking okay what this is +the probability of fixation when you + + align:start position:0% +the probability of fixation when you + + + align:start position:0% +the probability of fixation when you +have I individuals in the population so + + align:start position:0% +have I individuals in the population so + + + align:start position:0% +have I individuals in the population so +this is just I mean okay so and this is + + align:start position:0% +this is just I mean okay so and this is + + + align:start position:0% +this is just I mean okay so and this is +this is what we saw + + align:start position:0% + + + + align:start position:0% + +before + + align:start position:0% +before + + + align:start position:0% +before +okay this is permutation with relative + + align:start position:0% +okay this is permutation with relative + + + align:start position:0% +okay this is permutation with relative +Fitness R you have I individuals in the + + align:start position:0% +Fitness R you have I individuals in the + + + align:start position:0% +Fitness R you have I individuals in the +population total population size + + align:start position:0% +population total population size + + + align:start position:0% +population total population size +n right and what we want to know and and + + align:start position:0% +n right and what we want to know and and + + + align:start position:0% +n right and what we want to know and and +this becoming established means that XI + + align:start position:0% +this becoming established means that XI + + + align:start position:0% +this becoming established means that XI +is approximately equal to + + align:start position:0% + + + + align:start position:0% + +one + + align:start position:0% +one + + + align:start position:0% +one +right um now in in in these situations + + align:start position:0% +right um now in in in these situations + + + align:start position:0% +right um now in in in these situations +it's going to be R to the N is again + + align:start position:0% +it's going to be R to the N is again + + + align:start position:0% +it's going to be R to the N is again +very very large so this thing we can + + align:start position:0% +very very large so this thing we can + + + align:start position:0% +very very large so this thing we can +ignore so this is really the same thing + + align:start position:0% +ignore so this is really the same thing + + + align:start position:0% +ignore so this is really the same thing +is asking that 1 + + align:start position:0% + + + + align:start position:0% + +minus right and this never gets to be + + align:start position:0% +minus right and this never gets to be + + + align:start position:0% +minus right and this never gets to be +exactly equal to one but what then we're + + align:start position:0% +exactly equal to one but what then we're + + + align:start position:0% +exactly equal to one but what then we're +really asking is that this thing is + + align:start position:0% +really asking is that this thing is + + + align:start position:0% +really asking is that this thing is +close to one I.E we + + align:start position:0% +close to one I.E we + + + align:start position:0% +close to one I.E we +can this equivalent to saying that what + + align:start position:0% +can this equivalent to saying that what + + + align:start position:0% +can this equivalent to saying that what +do we want to say that 1 over R to the I + + align:start position:0% +do we want to say that 1 over R to the I + + + align:start position:0% +do we want to say that 1 over R to the I +is much less than + + align:start position:0% +is much less than + + + align:start position:0% +is much less than +one + + align:start position:0% + + + + align:start position:0% + +okay and uh right well that means the r + + align:start position:0% +okay and uh right well that means the r + + + align:start position:0% +okay and uh right well that means the r +to the I has much greater than + + align:start position:0% + + + + align:start position:0% + +one right so this is this is really + + align:start position:0% +one right so this is this is really + + + align:start position:0% +one right so this is this is really +saying that what you want is I * s to be + + align:start position:0% +saying that what you want is I * s to be + + + align:start position:0% +saying that what you want is I * s to be +much greater than + + align:start position:0% + + + + align:start position:0% + +one uh and this is then so so n + + align:start position:0% +one uh and this is then so so n + + + align:start position:0% +one uh and this is then so so n +established which is in this case this + + align:start position:0% +established which is in this case this + + + align:start position:0% +established which is in this case this +this it's the I such that this is true + + align:start position:0% + + + + align:start position:0% + +um right has to be much greater than one + + align:start position:0% +um right has to be much greater than one + + + align:start position:0% +um right has to be much greater than one +/ + + align:start position:0% +/ + + + align:start position:0% +/ +s + + align:start position:0% +s + + + align:start position:0% +s +okay and indeed I think that when when I + + align:start position:0% +okay and indeed I think that when when I + + + align:start position:0% +okay and indeed I think that when when I +is equal to 1 / + + align:start position:0% +is equal to 1 / + + + align:start position:0% +is equal to 1 / +s then the probability of fixation is + + align:start position:0% +s then the probability of fixation is + + + align:start position:0% +s then the probability of fixation is +um or I think it's the probability of + + align:start position:0% +um or I think it's the probability of + + + align:start position:0% +um or I think it's the probability of +Extinction is one over e if you kind of + + align:start position:0% +Extinction is one over e if you kind of + + + align:start position:0% +Extinction is one over e if you kind of +do the do the math okay so that means + + align:start position:0% +do the do the math okay so that means + + + align:start position:0% +do the do the math okay so that means +that this is kind of the crossing over + + align:start position:0% +that this is kind of the crossing over + + + align:start position:0% +that this is kind of the crossing over +point where you're more likely than not + + align:start position:0% +point where you're more likely than not + + + align:start position:0% +point where you're more likely than not +to + + align:start position:0% +to + + + align:start position:0% +to +survive + + align:start position:0% +survive + + + align:start position:0% +survive +okay and just to be concrete for many of + + align:start position:0% +okay and just to be concrete for many of + + + align:start position:0% +okay and just to be concrete for many of +the mutations we're going to be we're + + align:start position:0% +the mutations we're going to be we're + + + align:start position:0% +the mutations we're going to be we're +talking about and that you read about in + + align:start position:0% +talking about and that you read about in + + + align:start position:0% +talking about and that you read about in +Roy's paper uh s was a few percent right + + align:start position:0% +Roy's paper uh s was a few percent right + + + align:start position:0% +Roy's paper uh s was a few percent right +so this is saying that the population is + + align:start position:0% +so this is saying that the population is + + + align:start position:0% +so this is saying that the population is +established when the number of these + + align:start position:0% +established when the number of these + + + align:start position:0% +established when the number of these +mutant gets up to above 30 or you know a + + align:start position:0% +mutant gets up to above 30 or you know a + + + align:start position:0% +mutant gets up to above 30 or you know a +few times 30 so maybe 100 individuals + + align:start position:0% +few times 30 so maybe 100 individuals + + + align:start position:0% +few times 30 so maybe 100 individuals +means that it's unlikely to go extinct + + align:start position:0% + + + + align:start position:0% + +stochastically + + align:start position:0% +stochastically + + + align:start position:0% +stochastically +okay so it's really it's once you get to + + align:start position:0% +okay so it's really it's once you get to + + + align:start position:0% +okay so it's really it's once you get to +This n established then the population + + align:start position:0% +This n established then the population + + + align:start position:0% +This n established then the population +will grow exponentially in the + + align:start position:0% +will grow exponentially in the + + + align:start position:0% +will grow exponentially in the +population and it's going to spread + + align:start position:0% +population and it's going to spread + + + align:start position:0% +population and it's going to spread +exponentially with an advantage s + + align:start position:0% +exponentially with an advantage s + + + align:start position:0% +exponentially with an advantage s +relative to the rest of the + + align:start position:0% +relative to the rest of the + + + align:start position:0% +relative to the rest of the +population okay so this discussion is + + align:start position:0% +population okay so this discussion is + + + align:start position:0% +population okay so this discussion is +actually very useful for the next thing + + align:start position:0% +actually very useful for the next thing + + + align:start position:0% +actually very useful for the next thing +we want to talk about but yeah are there + + align:start position:0% +we want to talk about but yeah are there + + + align:start position:0% +we want to talk about but yeah are there +any questions about how we got + + align:start position:0% + + + + align:start position:0% + +this right + + align:start position:0% + + + + align:start position:0% + +yeah right so the probability of going + + align:start position:0% +yeah right so the probability of going + + + align:start position:0% +yeah right so the probability of going +extinct is um this is the probability of + + align:start position:0% +extinct is um this is the probability of + + + align:start position:0% +extinct is um this is the probability of +going + + align:start position:0% +going + + + align:start position:0% +going +extinct okay so the probability of going + + align:start position:0% +extinct okay so the probability of going + + + align:start position:0% +extinct okay so the probability of going +extinct here if you have I + + align:start position:0% +extinct here if you have I + + + align:start position:0% +extinct here if you have I +individuals is is is one over this guy + + align:start position:0% +individuals is is is one over this guy + + + align:start position:0% +individuals is is is one over this guy +so it's one over 1 plus s to the + + align:start position:0% +so it's one over 1 plus s to the + + + align:start position:0% +so it's one over 1 plus s to the +I right and then + + align:start position:0% +I right and then + + + align:start position:0% +I right and then +if I * s is 1 + + align:start position:0% +if I * s is 1 + + + align:start position:0% +if I * s is 1 +but s is + + align:start position:0% +but s is + + + align:start position:0% +but s is +small okay I mean this is you know this + + align:start position:0% +small okay I mean this is you know this + + + align:start position:0% +small okay I mean this is you know this +is one of those definitions of of e to + + align:start position:0% +is one of those definitions of of e to + + + align:start position:0% +is one of those definitions of of e to +the x that I don't know do you guys + + align:start position:0% +the x that I don't know do you guys + + + align:start position:0% +the x that I don't know do you guys +remember this is it it's like oh my + + align:start position:0% +remember this is it it's like oh my + + + align:start position:0% +remember this is it it's like oh my +goodness e to the + + align:start position:0% +goodness e to the + + + align:start position:0% +goodness e to the +x is the + + align:start position:0% + + + + align:start position:0% + +limit no no X is should be up there + + align:start position:0% +limit no no X is should be up there + + + align:start position:0% +limit no no X is should be up there +okay boy yeah and this you guys are + + align:start position:0% +okay boy yeah and this you guys are + + + align:start position:0% +okay boy yeah and this you guys are +taxing me all right um this is X over n + + align:start position:0% +taxing me all right um this is X over n + + + align:start position:0% +taxing me all right um this is X over n +to the + + align:start position:0% +to the + + + align:start position:0% +to the +n and this is limit as n goes to + + align:start position:0% +n and this is limit as n goes to + + + align:start position:0% +n and this is limit as n goes to +Infinity is this yes we agree + + align:start position:0% +Infinity is this yes we agree + + + align:start position:0% +Infinity is this yes we agree +okay this makes sense right um right so + + align:start position:0% +okay this makes sense right um right so + + + align:start position:0% +okay this makes sense right um right so +you I mean just if if right so this is + + align:start position:0% +you I mean just if if right so this is + + + align:start position:0% +you I mean just if if right so this is +this is just equivalent of saying that + + align:start position:0% +this is just equivalent of saying that + + + align:start position:0% +this is just equivalent of saying that +if I * s equal to 1 but s is small then + + align:start position:0% +if I * s equal to 1 but s is small then + + + align:start position:0% +if I * s equal to 1 but s is small then +this thing is around + + align:start position:0% + + + + align:start position:0% + +e + + align:start position:0% +e + + + align:start position:0% +e +okay um if you're confused by I I don't + + align:start position:0% +okay um if you're confused by I I don't + + + align:start position:0% +okay um if you're confused by I I don't +want I don't want to get into this too + + align:start position:0% +want I don't want to get into this too + + + align:start position:0% +want I don't want to get into this too +much because it's not quite Central to + + align:start position:0% +much because it's not quite Central to + + + align:start position:0% +much because it's not quite Central to +what we're talking about but uh come up + + align:start position:0% +what we're talking about but uh come up + + + align:start position:0% +what we're talking about but uh come up +and talk to me after the class and we'll + + align:start position:0% +and talk to me after the class and we'll + + + align:start position:0% +and talk to me after the class and we'll +derive this together okay but + + align:start position:0% +derive this together okay but + + + align:start position:0% +derive this together okay but +um right so the idea is that when when + + align:start position:0% +um right so the idea is that when when + + + align:start position:0% +um right so the idea is that when when +you've reached a population size of one + + align:start position:0% +you've reached a population size of one + + + align:start position:0% +you've reached a population size of one +/ s then you have a one over e + + align:start position:0% +/ s then you have a one over e + + + align:start position:0% +/ s then you have a one over e +probability of um going + + align:start position:0% +probability of um going + + + align:start position:0% +probability of um going +extinct okay so e pops up at all sorts + + align:start position:0% +extinct okay so e pops up at all sorts + + + align:start position:0% +extinct okay so e pops up at all sorts +of weird locations this is why you hear + + align:start position:0% +of weird locations this is why you hear + + + align:start position:0% +of weird locations this is why you hear +about it okay + + align:start position:0% +about it okay + + + align:start position:0% +about it okay +[Applause] + + align:start position:0% + + + + align:start position:0% + +um right so what I want to do now is I + + align:start position:0% +um right so what I want to do now is I + + + align:start position:0% +um right so what I want to do now is I +want to discuss this uh idea of uh + + align:start position:0% +want to discuss this uh idea of uh + + + align:start position:0% +want to discuss this uh idea of uh +clonal interference a little bit more in + + align:start position:0% +clonal interference a little bit more in + + + align:start position:0% +clonal interference a little bit more in +particular ask all right in what + + align:start position:0% +particular ask all right in what + + + align:start position:0% +particular ask all right in what +situation um will we have clonal + + align:start position:0% +situation um will we have clonal + + + align:start position:0% +situation um will we have clonal +interference or equivalently when can we + + align:start position:0% +interference or equivalently when can we + + + align:start position:0% +interference or equivalently when can we +ignore colonal + + align:start position:0% + + + + align:start position:0% + +interference all right can somebody say + + align:start position:0% +interference all right can somebody say + + + align:start position:0% +interference all right can somebody say +in words that when we're going to be + + align:start position:0% +in words that when we're going to be + + + align:start position:0% +in words that when we're going to be +able to ignore the effect of colonal + + align:start position:0% +able to ignore the effect of colonal + + + align:start position:0% +able to ignore the effect of colonal +interference + + align:start position:0% +interference + + + align:start position:0% +interference +yes size is large that there's very lied + + align:start position:0% +yes size is large that there's very lied + + + align:start position:0% +yes size is large that there's very lied +that those + + align:start position:0% +that those + + + align:start position:0% +that those +two okay I think we're goingon to have + + align:start position:0% +two okay I think we're goingon to have + + + align:start position:0% +two okay I think we're goingon to have +to be careful here all right so because + + align:start position:0% +to be careful here all right so because + + + align:start position:0% +to be careful here all right so because +you're saying oh well if the + + align:start position:0% +you're saying oh well if the + + + align:start position:0% +you're saying oh well if the +population is large enough then that + + align:start position:0% +population is large enough then that + + + align:start position:0% +population is large enough then that +you're saying oh the mutations won't + + align:start position:0% +you're saying oh the mutations won't + + + align:start position:0% +you're saying oh the mutations won't +interact right not in the beginning well + + align:start position:0% +interact right not in the beginning well + + + align:start position:0% +interact right not in the beginning well +they don't interact at the beginning I + + align:start position:0% +they don't interact at the beginning I + + + align:start position:0% +they don't interact at the beginning I +think that's that statement I'm very + + align:start position:0% +think that's that statement I'm very + + + align:start position:0% +think that's that statement I'm very +happy with but the problem is that if + + align:start position:0% +happy with but the problem is that if + + + align:start position:0% +happy with but the problem is that if +they both survive sastic extinction and + + align:start position:0% +they both survive sastic extinction and + + + align:start position:0% +they both survive sastic extinction and +they start spreading then they really do + + align:start position:0% +they start spreading then they really do + + + align:start position:0% +they start spreading then they really do +then they do start to interact in this + + align:start position:0% +then they do start to interact in this + + + align:start position:0% +then they do start to interact in this +large + + align:start position:0% +large + + + align:start position:0% +large +population right did you just say that + + align:start position:0% +population right did you just say that + + + align:start position:0% +population right did you just say that +once they survive sastic extinction they + + align:start position:0% +once they survive sastic extinction they + + + align:start position:0% +once they survive sastic extinction they +pretty much behave like they behave + + align:start position:0% +pretty much behave like they behave + + + align:start position:0% +pretty much behave like they behave +deterministically but the thing is that + + align:start position:0% +deterministically but the thing is that + + + align:start position:0% +deterministically but the thing is that +if you have two subpopulations that are + + align:start position:0% +if you have two subpopulations that are + + + align:start position:0% +if you have two subpopulations that are +exponentially growing and there are + + align:start position:0% +exponentially growing and there are + + + align:start position:0% +exponentially growing and there are +these very nice diagrams that I guess in + + align:start position:0% +these very nice diagrams that I guess in + + + align:start position:0% +these very nice diagrams that I guess in +Roy's paper they don't show which is if + + align:start position:0% +Roy's paper they don't show which is if + + + align:start position:0% +Roy's paper they don't show which is if +you if you look at the somehow the + + align:start position:0% +you if you look at the somehow the + + + align:start position:0% +you if you look at the somehow the +population okay um kind of changing as a + + align:start position:0% +population okay um kind of changing as a + + + align:start position:0% +population okay um kind of changing as a +function of time + + align:start position:0% + + + + align:start position:0% + +right you can think about okay well + + align:start position:0% +right you can think about okay well + + + align:start position:0% +right you can think about okay well +there's some this is we's say constant + + align:start position:0% +there's some this is we's say constant + + + align:start position:0% +there's some this is we's say constant +population size right and it starts out + + align:start position:0% +population size right and it starts out + + + align:start position:0% +population size right and it starts out +all being a particular type okay we'll + + align:start position:0% +all being a particular type okay we'll + + + align:start position:0% +all being a particular type okay we'll +say um there's you know some population + + align:start position:0% +say um there's you know some population + + + align:start position:0% +say um there's you know some population +of a and now new mutation arises and + + align:start position:0% +of a and now new mutation arises and + + + align:start position:0% +of a and now new mutation arises and +survives to C Extinction it starts + + align:start position:0% +survives to C Extinction it starts + + + align:start position:0% +survives to C Extinction it starts +spreading in the + + align:start position:0% +spreading in the + + + align:start position:0% +spreading in the +population all right this may be mutant + + align:start position:0% +population all right this may be mutant + + + align:start position:0% +population all right this may be mutant +B okay but then if another mutant + + align:start position:0% +B okay but then if another mutant + + + align:start position:0% +B okay but then if another mutant +appears over here that's even more + + align:start position:0% +appears over here that's even more + + + align:start position:0% +appears over here that's even more +fit + + align:start position:0% +fit + + + align:start position:0% +fit +then it can + + align:start position:0% +then it can + + + align:start position:0% +then it can +actually spread faster and indeed it can + + align:start position:0% +actually spread faster and indeed it can + + + align:start position:0% +actually spread faster and indeed it can +cause the B lineage to get out + + align:start position:0% +cause the B lineage to get out + + + align:start position:0% +cause the B lineage to get out +competed right so we start out with + + align:start position:0% +competed right so we start out with + + + align:start position:0% +competed right so we start out with +population a mutation B is more fit than + + align:start position:0% +population a mutation B is more fit than + + + align:start position:0% +population a mutation B is more fit than +a you know mutant B is more fit than a + + align:start position:0% +a you know mutant B is more fit than a + + + align:start position:0% +a you know mutant B is more fit than a +it's spreading exponentially but + + align:start position:0% +it's spreading exponentially but + + + align:start position:0% +it's spreading exponentially but +sometime later mutation C appears right + + align:start position:0% +sometime later mutation C appears right + + + align:start position:0% +sometime later mutation C appears right +now this C lineage is more fit than b so + + align:start position:0% +now this C lineage is more fit than b so + + + align:start position:0% +now this C lineage is more fit than b so +it's able to spread exponentially and + + align:start position:0% +it's able to spread exponentially and + + + align:start position:0% +it's able to spread exponentially and +indeed it out competes + + align:start position:0% + + + + align:start position:0% + +B okay so this is this is exactly what + + align:start position:0% +B okay so this is this is exactly what + + + align:start position:0% +B okay so this is this is exactly what +we mean by clonal interference these two + + align:start position:0% +we mean by clonal interference these two + + + align:start position:0% +we mean by clonal interference these two +lineages are interfering with each other + + align:start position:0% +lineages are interfering with each other + + + align:start position:0% +lineages are interfering with each other +okay so this thing is this is indeed + + align:start position:0% +okay so this thing is this is indeed + + + align:start position:0% +okay so this thing is this is indeed +colonal interference um and there have + + align:start position:0% +colonal interference um and there have + + + align:start position:0% +colonal interference um and there have +been these drawings out you know for + + align:start position:0% +been these drawings out you know for + + + align:start position:0% +been these drawings out you know for +maybe 20 years people have been thinking + + align:start position:0% +maybe 20 years people have been thinking + + + align:start position:0% +maybe 20 years people have been thinking +about this like lensky wrote some + + align:start position:0% +about this like lensky wrote some + + + align:start position:0% +about this like lensky wrote some +classic papers thinking about this uh + + align:start position:0% +classic papers thinking about this uh + + + align:start position:0% +classic papers thinking about this uh +recently Michael + + align:start position:0% +recently Michael + + + align:start position:0% +recently Michael +Desai at Harvard has done some really + + align:start position:0% +Desai at Harvard has done some really + + + align:start position:0% +Desai at Harvard has done some really +beautiful work where he takes these + + align:start position:0% +beautiful work where he takes these + + + align:start position:0% +beautiful work where he takes these +evolving yeast populations he does high + + align:start position:0% +evolving yeast populations he does high + + + align:start position:0% +evolving yeast populations he does high +resolution um now resolution in both + + align:start position:0% +resolution um now resolution in both + + + align:start position:0% +resolution um now resolution in both +senses temporal as well as deep kind of + + align:start position:0% +senses temporal as well as deep kind of + + + align:start position:0% +senses temporal as well as deep kind of +deep sequencing in the population where + + align:start position:0% +deep sequencing in the population where + + + align:start position:0% +deep sequencing in the population where +he can actually directly see uh see + + align:start position:0% +he can actually directly see uh see + + + align:start position:0% +he can actually directly see uh see +these these lineages spreading and then + + align:start position:0% +these these lineages spreading and then + + + align:start position:0% +these these lineages spreading and then +being out competed and he sees multiple + + align:start position:0% +being out competed and he sees multiple + + + align:start position:0% +being out competed and he sees multiple +mutations kind of spreading through the + + align:start position:0% +mutations kind of spreading through the + + + align:start position:0% +mutations kind of spreading through the +population together because they got + + align:start position:0% +population together because they got + + + align:start position:0% +population together because they got +they were attached on some genome it's + + align:start position:0% +they were attached on some genome it's + + + align:start position:0% +they were attached on some genome it's +really uh it's a very nice + + align:start position:0% +really uh it's a very nice + + + align:start position:0% +really uh it's a very nice +paper uh I almost had you guys read it + + align:start position:0% +paper uh I almost had you guys read it + + + align:start position:0% +paper uh I almost had you guys read it +so it's it's maybe nature in + + align:start position:0% +so it's it's maybe nature in + + + align:start position:0% +so it's it's maybe nature in + + align:start position:0% + + + align:start position:0% +[Music] + + align:start position:0% + + + + align:start position:0% + +13 I don't know possibly 12 + + align:start position:0% + + + + align:start position:0% + +okay right so this this is the idea of + + align:start position:0% +okay right so this this is the idea of + + + align:start position:0% +okay right so this this is the idea of +colonal interference okay so it's it's + + align:start position:0% +colonal interference okay so it's it's + + + align:start position:0% +colonal interference okay so it's it's +after the initial stochastic Dynamics + + align:start position:0% +after the initial stochastic Dynamics + + + align:start position:0% +after the initial stochastic Dynamics +have played out + + align:start position:0% + + + + align:start position:0% + +yes yeah so that is a result of clonal + + align:start position:0% +yes yeah so that is a result of clonal + + + align:start position:0% +yes yeah so that is a result of clonal +interference right because it's saying + + align:start position:0% +interference right because it's saying + + + align:start position:0% +interference right because it's saying +that that you know that half arises + + align:start position:0% +that that you know that half arises + + + align:start position:0% +that that you know that half arises +because if you know B maybe if it did + + align:start position:0% +because if you know B maybe if it did + + + align:start position:0% +because if you know B maybe if it did +survive it may still get out competed by + + align:start position:0% +survive it may still get out competed by + + + align:start position:0% +survive it may still get out competed by +a so that's that's that's clonal + + align:start position:0% +a so that's that's that's clonal + + + align:start position:0% +a so that's that's that's clonal +interference you say + + align:start position:0% + + + + align:start position:0% + +the right so the idea is that they don't + + align:start position:0% +the right so the idea is that they don't + + + align:start position:0% +the right so the idea is that they don't +interact initially because when they're + + align:start position:0% +interact initially because when they're + + + align:start position:0% +interact initially because when they're +when the mutations are present at very + + align:start position:0% +when the mutations are present at very + + + align:start position:0% +when the mutations are present at very +low frequency then they're really + + align:start position:0% +low frequency then they're really + + + align:start position:0% +low frequency then they're really +interacting with the bulk the rest of + + align:start position:0% +interacting with the bulk the rest of + + + align:start position:0% +interacting with the bulk the rest of +the population but 10 to the six there + + align:start position:0% +the population but 10 to the six there + + + align:start position:0% +the population but 10 to the six there +okay however if they survive stochastic + + align:start position:0% +okay however if they survive stochastic + + + align:start position:0% +okay however if they survive stochastic +Extinction and they start spreading in + + align:start position:0% +Extinction and they start spreading in + + + align:start position:0% +Extinction and they start spreading in +the population then there's the + + align:start position:0% +the population then there's the + + + align:start position:0% +the population then there's the +possibility of colonal + + align:start position:0% +possibility of colonal + + + align:start position:0% +possibility of colonal +interference + + align:start position:0% +interference + + + align:start position:0% +interference +would that change + + align:start position:0% +would that change + + + align:start position:0% +would that change +that no I think that's why it's a + + align:start position:0% +that no I think that's why it's a + + + align:start position:0% +that no I think that's why it's a +half right because this factor of half + + align:start position:0% +half right because this factor of half + + + align:start position:0% +half right because this factor of half +is really just saying that you know even + + align:start position:0% +is really just saying that you know even + + + align:start position:0% +is really just saying that you know even +if B survives stochastic Extinction it + + align:start position:0% +if B survives stochastic Extinction it + + + align:start position:0% +if B survives stochastic Extinction it +only has a 50-50 shot of actually being + + align:start position:0% +only has a 50-50 shot of actually being + + + align:start position:0% +only has a 50-50 shot of actually being +able to take over because there's a 50% + + align:start position:0% +able to take over because there's a 50% + + + align:start position:0% +able to take over because there's a 50% +chance it's going to be it's going to + + align:start position:0% +chance it's going to be it's going to + + + align:start position:0% +chance it's going to be it's going to +experience colonal interference with + + align:start position:0% +experience colonal interference with + + + align:start position:0% +experience colonal interference with +this a lineage that's going to + + align:start position:0% +this a lineage that's going to + + + align:start position:0% +this a lineage that's going to +outcompete + + align:start position:0% +outcompete + + + align:start position:0% +outcompete +it + + align:start position:0% + + + + align:start position:0% + +okay right uh you maybe if you know if + + align:start position:0% +okay right uh you maybe if you know if + + + align:start position:0% +okay right uh you maybe if you know if +there if you're unhappy about that + + align:start position:0% +there if you're unhappy about that + + + align:start position:0% +there if you're unhappy about that +statement harass me afterwards + + align:start position:0% +statement harass me afterwards + + + align:start position:0% +statement harass me afterwards +okay okay so but all right so from this + + align:start position:0% +okay okay so but all right so from this + + + align:start position:0% +okay okay so but all right so from this +discussion though um how can we think + + align:start position:0% +discussion though um how can we think + + + align:start position:0% +discussion though um how can we think +about the importance of colonal + + align:start position:0% +about the importance of colonal + + + align:start position:0% +about the importance of colonal +interference in particular um there are + + align:start position:0% +interference in particular um there are + + + align:start position:0% +interference in particular um there are +going to be two time scales and uh the + + align:start position:0% +going to be two time scales and uh the + + + align:start position:0% +going to be two time scales and uh the +question of whether there's going to be + + align:start position:0% +question of whether there's going to be + + + align:start position:0% +question of whether there's going to be +significant colon interference is + + align:start position:0% +significant colon interference is + + + align:start position:0% +significant colon interference is +related to which of these time scales is + + align:start position:0% +related to which of these time scales is + + + align:start position:0% +related to which of these time scales is +larger right all right so what what + + align:start position:0% +larger right all right so what what + + + align:start position:0% +larger right all right so what what +might the time scales + + align:start position:0% +might the time scales + + + align:start position:0% +might the time scales +be + + align:start position:0% + + + + align:start position:0% + +or at least one of the time + + align:start position:0% + + + + align:start position:0% + +scales I guess one should probably be + + align:start position:0% +scales I guess one should probably be + + + align:start position:0% +scales I guess one should probably be +the time to be established right to be + + align:start position:0% +the time to be established right to be + + + align:start position:0% +the time to be established right to be +established to reach the size + + align:start position:0% +established to reach the size + + + align:start position:0% +established to reach the size +established okay yeah as it turn yeah so + + align:start position:0% +established okay yeah as it turn yeah so + + + align:start position:0% +established okay yeah as it turn yeah so +this actually ends up not being um no + + align:start position:0% +this actually ends up not being um no + + + align:start position:0% +this actually ends up not being um no +but you know but it's very um right so + + align:start position:0% +but you know but it's very um right so + + + align:start position:0% +but you know but it's very um right so +the actual time that it takes from when + + align:start position:0% +the actual time that it takes from when + + + align:start position:0% +the actual time that it takes from when +a mutation appears to when it becomes + + align:start position:0% +a mutation appears to when it becomes + + + align:start position:0% +a mutation appears to when it becomes +established is um I mean there is a time + + align:start position:0% +established is um I mean there is a time + + + align:start position:0% +established is um I mean there is a time +time there but it's um it ends up not + + align:start position:0% +time there but it's um it ends up not + + + align:start position:0% +time there but it's um it ends up not +being the relevant thing because that's + + align:start position:0% +being the relevant thing because that's + + + align:start position:0% +being the relevant thing because that's +the regime where they're not actually uh + + align:start position:0% +the regime where they're not actually uh + + + align:start position:0% +the regime where they're not actually uh +interacting with that the mutant + + align:start position:0% +interacting with that the mutant + + + align:start position:0% +interacting with that the mutant +lineages are not interacting anyways + + align:start position:0% +lineages are not interacting anyways + + + align:start position:0% +lineages are not interacting anyways +right so there's a sense that it doesn't + + align:start position:0% +right so there's a sense that it doesn't + + + align:start position:0% +right so there's a sense that it doesn't +quite matter how long that takes at + + align:start position:0% +quite matter how long that takes at + + + align:start position:0% +quite matter how long that takes at +least to first + + align:start position:0% + + + + align:start position:0% + +order right okay so yeah so I think so + + align:start position:0% +order right okay so yeah so I think so + + + align:start position:0% +order right okay so yeah so I think so +one of them is going to be that the it's + + align:start position:0% +one of them is going to be that the it's + + + align:start position:0% +one of them is going to be that the it's +the time to go from + + align:start position:0% +the time to go from + + + align:start position:0% +the time to go from +established to + + align:start position:0% +established to + + + align:start position:0% +established to +fixation right so it's actually the next + + align:start position:0% +fixation right so it's actually the next + + + align:start position:0% +fixation right so it's actually the next +time scale there because and actually + + align:start position:0% +time scale there because and actually + + + align:start position:0% +time scale there because and actually +the time to get established is actually + + align:start position:0% +the time to get established is actually + + + align:start position:0% +the time to get established is actually +rather short because the lineages that + + align:start position:0% +rather short because the lineages that + + + align:start position:0% +rather short because the lineages that +you know so a mutation appears it most + + align:start position:0% +you know so a mutation appears it most + + + align:start position:0% +you know so a mutation appears it most +of the time goes extinct but the ones + + align:start position:0% +of the time goes extinct but the ones + + + align:start position:0% +of the time goes extinct but the ones +that don't go extinct actually get + + align:start position:0% +that don't go extinct actually get + + + align:start position:0% +that don't go extinct actually get +established rather quickly right you + + align:start position:0% +established rather quickly right you + + + align:start position:0% +established rather quickly right you +know because that's a biased sampling + + align:start position:0% +know because that's a biased sampling + + + align:start position:0% +know because that's a biased sampling +over the trajectories um right but but + + align:start position:0% +over the trajectories um right but but + + + align:start position:0% +over the trajectories um right but but +there is a rather significant time that + + align:start position:0% +there is a rather significant time that + + + align:start position:0% +there is a rather significant time that +it takes for the lineage to go from + + align:start position:0% +it takes for the lineage to go from + + + align:start position:0% +it takes for the lineage to go from +being established to actually fixing in + + align:start position:0% +being established to actually fixing in + + + align:start position:0% +being established to actually fixing in +the population so this is kind of how + + align:start position:0% +the population so this is kind of how + + + align:start position:0% +the population so this is kind of how +long it takes for a mutation to take + + align:start position:0% +long it takes for a mutation to take + + + align:start position:0% +long it takes for a mutation to take +over a population right so um we might + + align:start position:0% +over a population right so um we might + + + align:start position:0% +over a population right so um we might +call this the time to spread or + + align:start position:0% +call this the time to spread or + + + align:start position:0% +call this the time to spread or +so okay and it turns out that that time + + align:start position:0% +so okay and it turns out that that time + + + align:start position:0% +so okay and it turns out that that time +yeah what is it going to depend + + align:start position:0% +yeah what is it going to depend + + + align:start position:0% +yeah what is it going to depend +on it's going to depend on S right so as + + align:start position:0% +on it's going to depend on S right so as + + + align:start position:0% +on it's going to depend on S right so as +s goes up then this + + align:start position:0% +s goes up then this + + + align:start position:0% +s goes up then this +goes down okay all right Perfect all + + align:start position:0% +goes down okay all right Perfect all + + + align:start position:0% +goes down okay all right Perfect all +right let's just go put a one over s + + align:start position:0% +right let's just go put a one over s + + + align:start position:0% +right let's just go put a one over s +there right this and this be this is + + align:start position:0% +there right this and this be this is + + + align:start position:0% +there right this and this be this is +because it's going to grow exponentially + + align:start position:0% +because it's going to grow exponentially + + + align:start position:0% +because it's going to grow exponentially +in the population okay and then uh what + + align:start position:0% +in the population okay and then uh what + + + align:start position:0% +in the population okay and then uh what +how else is it going to depend on n n + + align:start position:0% +how else is it going to depend on n n + + + align:start position:0% +how else is it going to depend on n n +right and indeed uh this is going to be + + align:start position:0% +right and indeed uh this is going to be + + + align:start position:0% +right and indeed uh this is going to be +the log of n * s it's really n Over N + + align:start position:0% +the log of n * s it's really n Over N + + + align:start position:0% +the log of n * s it's really n Over N +established right because the idea is + + align:start position:0% +established right because the idea is + + + align:start position:0% +established right because the idea is +that you start out and established you + + align:start position:0% +that you start out and established you + + + align:start position:0% +that you start out and established you +grow exponentially with rate s until you + + align:start position:0% +grow exponentially with rate s until you + + + align:start position:0% +grow exponentially with rate s until you +kind of take over the population size + + align:start position:0% +kind of take over the population size + + + align:start position:0% +kind of take over the population size +n + + align:start position:0% +n + + + align:start position:0% +n +okay this this ass appears because it's + + align:start position:0% +okay this this ass appears because it's + + + align:start position:0% +okay this this ass appears because it's +one over n + + align:start position:0% +one over n + + + align:start position:0% +one over n +established because this in in the log + + align:start position:0% +established because this in in the log + + + align:start position:0% +established because this in in the log +is really like kind of the population + + align:start position:0% +is really like kind of the population + + + align:start position:0% +is really like kind of the population +size divided by n established okay okay + + align:start position:0% +size divided by n established okay okay + + + align:start position:0% +size divided by n established okay okay +so this is one time scale right do you + + align:start position:0% +so this is one time scale right do you + + + align:start position:0% +so this is one time scale right do you +guys understand why it should be like + + align:start position:0% +guys understand why it should be like + + + align:start position:0% +guys understand why it should be like +this + + align:start position:0% +this + + + align:start position:0% +this +okay + + align:start position:0% +okay + + + align:start position:0% +okay +all right and what's the other time + + align:start position:0% +all right and what's the other time + + + align:start position:0% +all right and what's the other time +scale that's relevant here + + align:start position:0% + + + + align:start position:0% + +yeah how fast mutation + + align:start position:0% +yeah how fast mutation + + + align:start position:0% +yeah how fast mutation +yes how long you have to wait from one + + align:start position:0% +yes how long you have to wait from one + + + align:start position:0% +yes how long you have to wait from one +mutation to the Next Mutation right okay + + align:start position:0% +mutation to the Next Mutation right okay + + + align:start position:0% +mutation to the Next Mutation right okay +so this is this is how long you have to + + align:start position:0% +so this is this is how long you have to + + + align:start position:0% +so this is this is how long you have to +wait for one mutation right so this is + + align:start position:0% +wait for one mutation right so this is + + + align:start position:0% +wait for one mutation right so this is +this is t t we call might call T + + align:start position:0% +this is t t we call might call T + + + align:start position:0% +this is t t we call might call T +mutation all right now it's a little bit + + align:start position:0% +mutation all right now it's a little bit + + + align:start position:0% +mutation all right now it's a little bit +subtle to think about what this is going + + align:start position:0% +subtle to think about what this is going + + + align:start position:0% +subtle to think about what this is going +to what what this should be right but it + + align:start position:0% +to what what this should be right but it + + + align:start position:0% +to what what this should be right but it +should say something about the time it + + align:start position:0% +should say something about the time it + + + align:start position:0% +should say something about the time it +takes for mutations to appear in the + + align:start position:0% +takes for mutations to appear in the + + + align:start position:0% +takes for mutations to appear in the +population right so we'll um let's go + + align:start position:0% +population right so we'll um let's go + + + align:start position:0% +population right so we'll um let's go +ahead and just guess what this might be + + align:start position:0% +ahead and just guess what this might be + + + align:start position:0% +ahead and just guess what this might be +for t- mutation should be equal to what + + align:start position:0% +for t- mutation should be equal to what + + + align:start position:0% +for t- mutation should be equal to what +all right so it could + + align:start position:0% + + + + align:start position:0% + +be + + align:start position:0% +be + + + align:start position:0% +be +um yeah right so yeah so I I you know so + + align:start position:0% +um yeah right so yeah so I I you know so + + + align:start position:0% +um yeah right so yeah so I I you know so +I guess I'm trying to get you to think + + align:start position:0% +I guess I'm trying to get you to think + + + align:start position:0% +I guess I'm trying to get you to think +about what this should mean to be + + align:start position:0% +about what this should mean to be + + + align:start position:0% +about what this should mean to be +relevant for determining the time scales + + align:start position:0% +relevant for determining the time scales + + + align:start position:0% +relevant for determining the time scales +of whether clonal interference is + + align:start position:0% +of whether clonal interference is + + + align:start position:0% +of whether clonal interference is +important mu is + + align:start position:0% +important mu is + + + align:start position:0% +important mu is +the probability per generation of having + + align:start position:0% +the probability per generation of having + + + align:start position:0% +the probability per generation of having +a beneficial mutation of magnitude s + + align:start position:0% +a beneficial mutation of magnitude s + + + align:start position:0% +a beneficial mutation of magnitude s +okay mu is the um is is you know is kind + + align:start position:0% +okay mu is the um is is you know is kind + + + align:start position:0% +okay mu is the um is is you know is kind +of the mutation rate is what you + + align:start position:0% + + + + align:start position:0% + +know right but we'll just assume that + + align:start position:0% +know right but we'll just assume that + + + align:start position:0% +know right but we'll just assume that +that that there's only one kind of + + align:start position:0% +that that there's only one kind of + + + align:start position:0% +that that there's only one kind of +beneficial mutation and every beneficial + + align:start position:0% +beneficial mutation and every beneficial + + + align:start position:0% +beneficial mutation and every beneficial +m mutation has magnitude s for + + align:start position:0% +m mutation has magnitude s for + + + align:start position:0% +m mutation has magnitude s for +Simplicity right so it's mutation rate + + align:start position:0% +Simplicity right so it's mutation rate + + + align:start position:0% +Simplicity right so it's mutation rate +per you know it's a beneficial mutation + + align:start position:0% +per you know it's a beneficial mutation + + + align:start position:0% +per you know it's a beneficial mutation +rate per generation of of leading to + + align:start position:0% +rate per generation of of leading to + + + align:start position:0% +rate per generation of of leading to +mutation s + + align:start position:0% + + + + align:start position:0% + +um and you can just also say if you're + + align:start position:0% +um and you can just also say if you're + + + align:start position:0% +um and you can just also say if you're +if you have no idea why what I'm talking + + align:start position:0% +if you have no idea why what I'm talking + + + align:start position:0% +if you have no idea why what I'm talking +about it's fine but I just you know it's + + align:start position:0% +about it's fine but I just you know it's + + + align:start position:0% +about it's fine but I just you know it's +worth spending a little bit bit of time + + align:start position:0% +worth spending a little bit bit of time + + + align:start position:0% +worth spending a little bit bit of time +thinking about what should be the + + align:start position:0% +thinking about what should be the + + + align:start position:0% +thinking about what should be the +relevant time scale to compare to this + + align:start position:0% + + + + align:start position:0% + +yes yes that's + + align:start position:0% + + + + align:start position:0% + +right and it's okay if you find this + + align:start position:0% +right and it's okay if you find this + + + align:start position:0% +right and it's okay if you find this +confusing because this is this is subtle + + align:start position:0% +confusing because this is this is subtle + + + align:start position:0% +confusing because this is this is subtle +but if you think about it for 30 seconds + + align:start position:0% +but if you think about it for 30 seconds + + + align:start position:0% +but if you think about it for 30 seconds +then maybe you'll be you know fertile + + align:start position:0% +then maybe you'll be you know fertile + + + align:start position:0% +then maybe you'll be you know fertile +ground to to for the disc discussion to + + align:start position:0% +ground to to for the disc discussion to + + + align:start position:0% +ground to to for the disc discussion to +follow + + align:start position:0% + + + + align:start position:0% + +maybe + + align:start position:0% + + + + align:start position:0% + +um all right let's go ahead and vote and + + align:start position:0% +um all right let's go ahead and vote and + + + align:start position:0% +um all right let's go ahead and vote and +see where we are ready three two + + align:start position:0% +see where we are ready three two + + + align:start position:0% +see where we are ready three two +one all right + + align:start position:0% +one all right + + + align:start position:0% +one all right +I I all right this is very nice okay + + align:start position:0% +I I all right this is very nice okay + + + align:start position:0% +I I all right this is very nice okay +almost everybody is saying C although um + + align:start position:0% +almost everybody is saying C although um + + + align:start position:0% +almost everybody is saying C although um +it really should be D okay + + align:start position:0% + + + + align:start position:0% + +um so s time and + + align:start position:0% + + + + align:start position:0% + +one okay that's an interesting statement + + align:start position:0% +one okay that's an interesting statement + + + align:start position:0% +one okay that's an interesting statement +um all right so uh S I mean I guess this + + align:start position:0% +um all right so uh S I mean I guess this + + + align:start position:0% +um all right so uh S I mean I guess this +is a relative + + align:start position:0% +is a relative + + + align:start position:0% +is a relative +Fitness but you right there you have S + + align:start position:0% +Fitness but you right there you have S + + + align:start position:0% +Fitness but you right there you have S +to time + + align:start position:0% +to time + + + align:start position:0% +to time +one of boy it's a good you know yeah so + + align:start position:0% +one of boy it's a good you know yeah so + + + align:start position:0% +one of boy it's a good you know yeah so +the problem is that this is this is all + + align:start position:0% +the problem is that this is this is all + + + align:start position:0% +the problem is that this is this is all +in unit it's a a generation time right + + align:start position:0% +in unit it's a a generation time right + + + align:start position:0% +in unit it's a a generation time right +so this is because this is really + + align:start position:0% +so this is because this is really + + + align:start position:0% +so this is because this is really +telling us about the number of + + align:start position:0% +telling us about the number of + + + align:start position:0% +telling us about the number of +generations + + align:start position:0% +generations + + + align:start position:0% +generations +um + + align:start position:0% +um + + + align:start position:0% +um +so um what is going on that's an + + align:start position:0% +so um what is going on that's an + + + align:start position:0% +so um what is going on that's an +interesting um because one of mu should + + align:start position:0% +interesting um because one of mu should + + + align:start position:0% +interesting um because one of mu should +also be a time right + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% + + + + align:start position:0% + +yeah yeah I I'm not sure if it yeah I + + align:start position:0% +yeah yeah I I'm not sure if it yeah I + + + align:start position:0% +yeah yeah I I'm not sure if it yeah I +mean since this is all in Generations + + align:start position:0% +mean since this is all in Generations + + + align:start position:0% +mean since this is all in Generations +I'm not sure if you even have to + + align:start position:0% + + + + align:start position:0% + +um yeah I think it's + + align:start position:0% + + + + align:start position:0% + +okay I I like that statement but then + + align:start position:0% +okay I I like that statement but then + + + align:start position:0% +okay I I like that statement but then +that's not cons you know yeah but then + + align:start position:0% +that's not cons you know yeah but then + + + align:start position:0% +that's not cons you know yeah but then +he you know I mean + + align:start position:0% +he you know I mean + + + align:start position:0% +he you know I mean +one yeah know but he but then he this + + align:start position:0% +one yeah know but he but then he this + + + align:start position:0% +one yeah know but he but then he this +should have units of I mean I guess the + + align:start position:0% +should have units of I mean I guess the + + + align:start position:0% +should have units of I mean I guess the +the I I I agree with your statement but + + align:start position:0% +the I I I agree with your statement but + + + align:start position:0% +the I I I agree with your statement but +I also you know sort of agree with his + + align:start position:0% +I also you know sort of agree with his + + + align:start position:0% +I also you know sort of agree with his +that one over asked you know that's the + + align:start position:0% +that one over asked you know that's the + + + align:start position:0% +that one over asked you know that's the +problem is phasically yeah but I think + + align:start position:0% +problem is phasically yeah but I think + + + align:start position:0% +problem is phasically yeah but I think +that it's really that it's all you know + + align:start position:0% +that it's really that it's all you know + + + align:start position:0% +that it's really that it's all you know +it's all because everything in units of + + align:start position:0% +it's all because everything in units of + + + align:start position:0% +it's all because everything in units of +generation so it's it's really that all + + align:start position:0% +generation so it's it's really that all + + + align:start position:0% +generation so it's it's really that all +it's all unitless except for me yeah + + align:start position:0% +it's all unitless except for me yeah + + + align:start position:0% +it's all unitless except for me yeah +what I don't understand is why the how + + align:start position:0% +what I don't understand is why the how + + + align:start position:0% +what I don't understand is why the how +beneficial the mutation is should play + + align:start position:0% +beneficial the mutation is should play + + + align:start position:0% +beneficial the mutation is should play +into how yeah yeah no I agree it's this + + align:start position:0% +into how yeah yeah no I agree it's this + + + align:start position:0% +into how yeah yeah no I agree it's this +is subtle okay right so let's imagine + + align:start position:0% +is subtle okay right so let's imagine + + + align:start position:0% +is subtle okay right so let's imagine +this is + + align:start position:0% + + + + align:start position:0% + +time okay now 1 over mu is telling us um + + align:start position:0% +time okay now 1 over mu is telling us um + + + align:start position:0% +time okay now 1 over mu is telling us um +how much how how how much time there is + + align:start position:0% +how much how how how much time there is + + + align:start position:0% +how much how how how much time there is +between the initial appearance of these + + align:start position:0% +between the initial appearance of these + + + align:start position:0% +between the initial appearance of these +beneficial + + align:start position:0% +beneficial + + + align:start position:0% +beneficial +mutants right all right so here we get a + + align:start position:0% +mutants right all right so here we get a + + + align:start position:0% +mutants right all right so here we get a +beneficial + + align:start position:0% +beneficial + + + align:start position:0% +beneficial +mutation all right but what do you what + + align:start position:0% +mutation all right but what do you what + + + align:start position:0% +mutation all right but what do you what +do you think is going to happen to that + + align:start position:0% +do you think is going to happen to that + + + align:start position:0% +do you think is going to happen to that +beneficial + + align:start position:0% +beneficial + + + align:start position:0% +beneficial +mutation ah yeah that guy's dead he + + align:start position:0% +mutation ah yeah that guy's dead he + + + align:start position:0% +mutation ah yeah that guy's dead he +comes up okay all right how long do we + + align:start position:0% +comes up okay all right how long do we + + + align:start position:0% +comes up okay all right how long do we +have to wait before the next beneficial + + align:start position:0% +have to wait before the next beneficial + + + align:start position:0% +have to wait before the next beneficial +mutation one over mu is it going to be + + align:start position:0% +mutation one over mu is it going to be + + + align:start position:0% +mutation one over mu is it going to be +exactly that is it going to be peaked + + align:start position:0% +exactly that is it going to be peaked + + + align:start position:0% +exactly that is it going to be peaked +around that + + align:start position:0% + + + + align:start position:0% + +all right the all right verbal answer + + align:start position:0% +all right the all right verbal answer + + + align:start position:0% +all right the all right verbal answer +what is going to be the probability + + align:start position:0% +what is going to be the probability + + + align:start position:0% +what is going to be the probability +distribution between successive + + align:start position:0% +distribution between successive + + + align:start position:0% +distribution between successive +appearances of this beneficial mutation + + align:start position:0% +appearances of this beneficial mutation + + + align:start position:0% +appearances of this beneficial mutation +ready three two one exponential + + align:start position:0% +ready three two one exponential + + + align:start position:0% +ready three two one exponential +exponentially distributed okay so there + + align:start position:0% +exponentially distributed okay so there + + + align:start position:0% +exponentially distributed okay so there +might be another one that's going to + + align:start position:0% +might be another one that's going to + + + align:start position:0% +might be another one that's going to +appear here what do you think is going + + align:start position:0% +appear here what do you think is going + + + align:start position:0% +appear here what do you think is going +to happen to that guy oh he's dead yeah + + align:start position:0% +to happen to that guy oh he's dead yeah + + + align:start position:0% +to happen to that guy oh he's dead yeah +okay um all right another one okay so + + align:start position:0% +okay um all right another one okay so + + + align:start position:0% +okay um all right another one okay so +these guys are appearing at right but if + + align:start position:0% +these guys are appearing at right but if + + + align:start position:0% +these guys are appearing at right but if +if the magnitude of s is is say 02 that + + align:start position:0% +if the magnitude of s is is say 02 that + + + align:start position:0% +if the magnitude of s is is say 02 that +means we have to wait for 50 of these + + align:start position:0% +means we have to wait for 50 of these + + + align:start position:0% +means we have to wait for 50 of these +things to appear before we expect that + + align:start position:0% +things to appear before we expect that + + + align:start position:0% +things to appear before we expect that +one of them is actually going to get + + align:start position:0% +one of them is actually going to get + + + align:start position:0% +one of them is actually going to get +established and established means it + + align:start position:0% +established and established means it + + + align:start position:0% +established and established means it +gets up to one / + + align:start position:0% +gets up to one / + + + align:start position:0% +gets up to one / +s + + align:start position:0% + + + + align:start position:0% + +right okay so this guy once he's + + align:start position:0% +right okay so this guy once he's + + + align:start position:0% +right okay so this guy once he's +established he's going to grow + + align:start position:0% +established he's going to grow + + + align:start position:0% +established he's going to grow +exponentially in the + + align:start position:0% +exponentially in the + + + align:start position:0% +exponentially in the +population okay but the idea is that the + + align:start position:0% +population okay but the idea is that the + + + align:start position:0% +population okay but the idea is that the +time scale + + align:start position:0% +time scale + + + align:start position:0% +time scale +here of 1/ mu is the time between + + align:start position:0% +here of 1/ mu is the time between + + + align:start position:0% +here of 1/ mu is the time between +successive appearances of this + + align:start position:0% +successive appearances of this + + + align:start position:0% +successive appearances of this +beneficial mutation whereas 1 / + + align:start position:0% + + + + align:start position:0% + +Ms is the time scale between successive + + align:start position:0% +Ms is the time scale between successive + + + align:start position:0% +Ms is the time scale between successive +establishments of these beneficial + + align:start position:0% +establishments of these beneficial + + + align:start position:0% +establishments of these beneficial +mutations and it's only if they get + + align:start position:0% +mutations and it's only if they get + + + align:start position:0% +mutations and it's only if they get +established that they're relevant + + align:start position:0% +established that they're relevant + + + align:start position:0% +established that they're relevant +okay so that's why what the T mutation + + align:start position:0% +okay so that's why what the T mutation + + + align:start position:0% +okay so that's why what the T mutation +established is one over + + align:start position:0% +established is one over + + + align:start position:0% +established is one over +Ms okay all right + + align:start position:0% + + + + align:start position:0% + +now no clonal interference means that + + align:start position:0% +now no clonal interference means that + + + align:start position:0% +now no clonal interference means that +one of these is larger than the other + + align:start position:0% +one of these is larger than the other + + + align:start position:0% +one of these is larger than the other +one okay which all right so which so no + + align:start position:0% +one okay which all right so which so no + + + align:start position:0% +one okay which all right so which so no +clonal interference means is it a this + + align:start position:0% +clonal interference means is it a this + + + align:start position:0% +clonal interference means is it a this +guy is larger or B this guy is + + align:start position:0% + + + + align:start position:0% + +larger okay this is larger question mark + + align:start position:0% +larger okay this is larger question mark + + + align:start position:0% +larger okay this is larger question mark +this one that one right think about this + + align:start position:0% +this one that one right think about this + + + align:start position:0% +this one that one right think about this +for 15 seconds just to make sure that + + align:start position:0% +for 15 seconds just to make sure that + + + align:start position:0% +for 15 seconds just to make sure that +we're right make sure we're asking if + + align:start position:0% +we're right make sure we're asking if + + + align:start position:0% +we're right make sure we're asking if +there's no clonal inference it means + + align:start position:0% +there's no clonal inference it means + + + align:start position:0% +there's no clonal inference it means +that one of these is much larger than + + align:start position:0% +that one of these is much larger than + + + align:start position:0% +that one of these is much larger than +the other one which one okay ready 3 2 + + align:start position:0% +the other one which one okay ready 3 2 + + + align:start position:0% +the other one which one okay ready 3 2 +1 okay it means that this thing is much + + align:start position:0% +1 okay it means that this thing is much + + + align:start position:0% +1 okay it means that this thing is much +larger than this one + + align:start position:0% +larger than this one + + + align:start position:0% +larger than this one +right so this thing has to be much + + align:start position:0% +right so this thing has to be much + + + align:start position:0% +right so this thing has to be much +larger + + align:start position:0% +larger + + + align:start position:0% +larger +than t t established to + + align:start position:0% +than t t established to + + + align:start position:0% +than t t established to +fix okay right because if it's the case + + align:start position:0% +fix okay right because if it's the case + + + align:start position:0% +fix okay right because if it's the case +this time scale is very large compared + + align:start position:0% +this time scale is very large compared + + + align:start position:0% +this time scale is very large compared +to this time scale of spreading then the + + align:start position:0% +to this time scale of spreading then the + + + align:start position:0% +to this time scale of spreading then the +patients don't ever uh clonally + + align:start position:0% +patients don't ever uh clonally + + + align:start position:0% +patients don't ever uh clonally +interfere + + align:start position:0% +interfere + + + align:start position:0% +interfere +okay I think it's very important that + + align:start position:0% +okay I think it's very important that + + + align:start position:0% +okay I think it's very important that +you uh can reconstruct this whole + + align:start position:0% +you uh can reconstruct this whole + + + align:start position:0% +you uh can reconstruct this whole +argument because + + align:start position:0% +argument because + + + align:start position:0% +argument because +it has all the ingredients of the + + align:start position:0% +it has all the ingredients of the + + + align:start position:0% +it has all the ingredients of the +Dynamics in terms of + + align:start position:0% +Dynamics in terms of + + + align:start position:0% +Dynamics in terms of +stochastic uh and then uh deterministic + + align:start position:0% +stochastic uh and then uh deterministic + + + align:start position:0% +stochastic uh and then uh deterministic +and and you know so uh if if you if you + + align:start position:0% +and and you know so uh if if you if you + + + align:start position:0% +and and you know so uh if if you if you +find this stuff confusing please uh go + + align:start position:0% +find this stuff confusing please uh go + + + align:start position:0% +find this stuff confusing please uh go +through it with a friend or uh come to + + align:start position:0% +through it with a friend or uh come to + + + align:start position:0% +through it with a friend or uh come to +me after + + align:start position:0% + + + + align:start position:0% + +class all right so what U what we want + + align:start position:0% +class all right so what U what we want + + + align:start position:0% +class all right so what U what we want +to do for the last 20 minutes is then uh + + align:start position:0% +to do for the last 20 minutes is then uh + + + align:start position:0% +to do for the last 20 minutes is then uh +is talk about Roy's paper Okay um and I + + align:start position:0% +is talk about Roy's paper Okay um and I + + + align:start position:0% +is talk about Roy's paper Okay um and I +I think that this this paper is is + + align:start position:0% +I think that this this paper is is + + + align:start position:0% +I think that this this paper is is +interesting and and um subtle it's a + + align:start position:0% +interesting and and um subtle it's a + + + align:start position:0% +interesting and and um subtle it's a +little bit hard to tell how much of it + + align:start position:0% +little bit hard to tell how much of it + + + align:start position:0% +little bit hard to tell how much of it +is uh is an experimental kind of + + align:start position:0% +is uh is an experimental kind of + + + align:start position:0% +is uh is an experimental kind of +straightup demonstration or how much of + + align:start position:0% +straightup demonstration or how much of + + + align:start position:0% +straightup demonstration or how much of +it is that it's just a way of getting + + align:start position:0% +it is that it's just a way of getting + + + align:start position:0% +it is that it's just a way of getting +you to think new thoughts I um it's + + align:start position:0% +you to think new thoughts I um it's + + + align:start position:0% +you to think new thoughts I um it's +certainly is a way to get you to think + + align:start position:0% +certainly is a way to get you to think + + + align:start position:0% +certainly is a way to get you to think +new thoughts at least it very much got I + + align:start position:0% +new thoughts at least it very much got I + + + align:start position:0% +new thoughts at least it very much got I +I felt that it had that effect on me and + + align:start position:0% +I felt that it had that effect on me and + + + align:start position:0% +I felt that it had that effect on me and +that um I you know after reading it I + + align:start position:0% +that um I you know after reading it I + + + align:start position:0% +that um I you know after reading it I +kind I just got you know very excited + + align:start position:0% +kind I just got you know very excited + + + align:start position:0% +kind I just got you know very excited +about all the Dynamics that we at play + + align:start position:0% +about all the Dynamics that we at play + + + align:start position:0% +about all the Dynamics that we at play +here and how I you know out of the + + align:start position:0% +here and how I you know out of the + + + align:start position:0% +here and how I you know out of the +complexity of this colonial interference + + align:start position:0% +complexity of this colonial interference + + + align:start position:0% +complexity of this colonial interference +process maybe in some cases there might + + align:start position:0% +process maybe in some cases there might + + + align:start position:0% +process maybe in some cases there might +be some uh even simpler phenomenological + + align:start position:0% +be some uh even simpler phenomenological + + + align:start position:0% +be some uh even simpler phenomenological +type description of what was going on uh + + align:start position:0% +type description of what was going on uh + + + align:start position:0% +type description of what was going on uh +but I think that what is very + + align:start position:0% +but I think that what is very + + + align:start position:0% +but I think that what is very +interesting about that paper is this + + align:start position:0% +interesting about that paper is this + + + align:start position:0% +interesting about that paper is this +idea that what they really wanted to + + align:start position:0% +idea that what they really wanted to + + + align:start position:0% +idea that what they really wanted to +measure was this probability + + align:start position:0% +measure was this probability + + + align:start position:0% +measure was this probability +distribution of beneficial mutations + + align:start position:0% +distribution of beneficial mutations + + + align:start position:0% +distribution of beneficial mutations +okay so what we mean by that is that + + align:start position:0% +okay so what we mean by that is that + + + align:start position:0% +okay so what we mean by that is that +different beneficial mutations will have + + align:start position:0% +different beneficial mutations will have + + + align:start position:0% +different beneficial mutations will have +different effects + + align:start position:0% + + + + align:start position:0% + +right and in particular you can imagine + + align:start position:0% +right and in particular you can imagine + + + align:start position:0% +right and in particular you can imagine +a thought experiment where you take any + + align:start position:0% +a thought experiment where you take any + + + align:start position:0% +a thought experiment where you take any +ecoli cell uh how um how big is thecoli + + align:start position:0% +ecoli cell uh how um how big is thecoli + + + align:start position:0% +ecoli cell uh how um how big is thecoli +genome roughly um this is an just like + + align:start position:0% +genome roughly um this is an just like + + + align:start position:0% +genome roughly um this is an just like +it's always good to have guide posts for + + align:start position:0% +it's always good to have guide posts for + + + align:start position:0% +it's always good to have guide posts for +how long ago things happened it's also + + align:start position:0% +how long ago things happened it's also + + + align:start position:0% +how long ago things happened it's also +good to have guide posts for things like + + align:start position:0% +good to have guide posts for things like + + + align:start position:0% +good to have guide posts for things like +a just good to have a few genome sizes + + align:start position:0% +a just good to have a few genome sizes + + + align:start position:0% +a just good to have a few genome sizes +kind of memorized right uh yeah does + + align:start position:0% +kind of memorized right uh yeah does + + + align:start position:0% +kind of memorized right uh yeah does +anybody know the coli + + align:start position:0% +anybody know the coli + + + align:start position:0% +anybody know the coli +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +genome 2,000 base + + align:start position:0% +genome 2,000 base + + + align:start position:0% +genome 2,000 base +pairs okay no no I just want to make + + align:start position:0% +pairs okay no no I just want to make + + + align:start position:0% +pairs okay no no I just want to make +sure that we're uh yeah yeah okay so + + align:start position:0% +sure that we're uh yeah yeah okay so + + + align:start position:0% +sure that we're uh yeah yeah okay so +yeah it's a bit more than that but yeah + + align:start position:0% +yeah it's a bit more than that but yeah + + + align:start position:0% +yeah it's a bit more than that but yeah +so it's um it's a it's a few million + + align:start position:0% +so it's um it's a it's a few million + + + align:start position:0% +so it's um it's a it's a few million +base pairs right three or four depending + + align:start position:0% +base pairs right three or four depending + + + align:start position:0% +base pairs right three or four depending +on the strain okay but you can imagine a + + align:start position:0% +on the strain okay but you can imagine a + + + align:start position:0% +on the strain okay but you can imagine a +thought experiment where you go in and + + align:start position:0% +thought experiment where you go in and + + + align:start position:0% +thought experiment where you go in and +for at every base pair you make um you + + align:start position:0% +for at every base pair you make um you + + + align:start position:0% +for at every base pair you make um you +make the three possible point mutations + + align:start position:0% +make the three possible point mutations + + + align:start position:0% +make the three possible point mutations +okay so then you can imagine having 10 + + align:start position:0% +okay so then you can imagine having 10 + + + align:start position:0% +okay so then you can imagine having 10 +million different strains that are each + + align:start position:0% +million different strains that are each + + + align:start position:0% +million different strains that are each +different at one site okay and then what + + align:start position:0% +different at one site okay and then what + + + align:start position:0% +different at one site okay and then what +we can do is we can plot + + align:start position:0% +we can do is we can plot + + + align:start position:0% +we can do is we can plot +the the rate of population growth in + + align:start position:0% +the the rate of population growth in + + + align:start position:0% +the the rate of population growth in +some environment right so this is + + align:start position:0% +some environment right so this is + + + align:start position:0% +some environment right so this is +gamma it's the 1/ N DN + + align:start position:0% +gamma it's the 1/ N DN + + + align:start position:0% +gamma it's the 1/ N DN +DT you know basically division rate + + align:start position:0% +DT you know basically division rate + + + align:start position:0% +DT you know basically division rate +normalized + + align:start position:0% +normalized + + + align:start position:0% +normalized +by um the Y type division right okay I'm + + align:start position:0% +by um the Y type division right okay I'm + + + align:start position:0% +by um the Y type division right okay I'm +sorry I'm that's supposed to be down + + align:start position:0% +sorry I'm that's supposed to be down + + + align:start position:0% +sorry I'm that's supposed to be down +there so this is this is gamma U over + + align:start position:0% +there so this is this is gamma U over + + + align:start position:0% +there so this is this is gamma U over +gamma of wild type and this could be you + + align:start position:0% +gamma of wild type and this could be you + + + align:start position:0% +gamma of wild type and this could be you +know eoli + + align:start position:0% +know eoli + + + align:start position:0% +know eoli +in lb or minimal Media or you know at + + align:start position:0% +in lb or minimal Media or you know at + + + align:start position:0% +in lb or minimal Media or you know at +30C pick some reasonable environment + + align:start position:0% +30C pick some reasonable environment + + + align:start position:0% +30C pick some reasonable environment +okay the question is if you draw the + + align:start position:0% +okay the question is if you draw the + + + align:start position:0% +okay the question is if you draw the +histogram of what this thing should look + + align:start position:0% +histogram of what this thing should look + + + align:start position:0% +histogram of what this thing should look +like you know what should it + + align:start position:0% +like you know what should it + + + align:start position:0% +like you know what should it +be + + align:start position:0% + + + + align:start position:0% + +all right now what I'm going to ask you + + align:start position:0% +all right now what I'm going to ask you + + + align:start position:0% +all right now what I'm going to ask you +to do is in 30 + + align:start position:0% +to do is in 30 + + + align:start position:0% +to do is in 30 +seconds draw something on your sheet of + + align:start position:0% +seconds draw something on your sheet of + + + align:start position:0% +seconds draw something on your sheet of +paper right so this is this is what I'm + + align:start position:0% +paper right so this is this is what I'm + + + align:start position:0% +paper right so this is this is what I'm +this I'm trying this is supposed to be a + + align:start position:0% +this I'm trying this is supposed to be a + + + align:start position:0% +this I'm trying this is supposed to be a +frequency or a + + align:start position:0% +frequency or a + + + align:start position:0% +frequency or a +histogram over those 10 million m point + + align:start position:0% +histogram over those 10 million m point + + + align:start position:0% +histogram over those 10 million m point +point mutations right so we haven't + + align:start position:0% +point mutations right so we haven't + + + align:start position:0% +point mutations right so we haven't +actually done this experiment but I + + align:start position:0% +actually done this experiment but I + + + align:start position:0% +actually done this experiment but I +think it's um people have been doing + + align:start position:0% +think it's um people have been doing + + + align:start position:0% +think it's um people have been doing +some they actually we have made all + + align:start position:0% +some they actually we have made all + + + align:start position:0% +some they actually we have made all +possible Gene Knockouts in in uh in eoli + + align:start position:0% +possible Gene Knockouts in in uh in eoli + + + align:start position:0% +possible Gene Knockouts in in uh in eoli +so removing each of each of the genes + + align:start position:0% +so removing each of each of the genes + + + align:start position:0% +so removing each of each of the genes +right U and we've we've done that in in + + align:start position:0% +right U and we've we've done that in in + + + align:start position:0% +right U and we've we've done that in in +eoli we've done it in yeast and indeed + + align:start position:0% +eoli we've done it in yeast and indeed + + + align:start position:0% +eoli we've done it in yeast and indeed +in yeast they're actually making and + + align:start position:0% +in yeast they're actually making and + + + align:start position:0% +in yeast they're actually making and +measuring the division rate for all + + align:start position:0% +measuring the division rate for all + + + align:start position:0% +measuring the division rate for all +pairwise + + align:start position:0% +pairwise + + + align:start position:0% +pairwise +Knockouts right so the their their some + + align:start position:0% +Knockouts right so the their their some + + + align:start position:0% +Knockouts right so the their their some +fraction of the way through they + + align:start position:0% +fraction of the way through they + + + align:start position:0% +fraction of the way through they +published their first 10 million + + align:start position:0% +published their first 10 million + + + align:start position:0% +published their first 10 million +measurements for the division rate of + + align:start position:0% +measurements for the division rate of + + + align:start position:0% +measurements for the division rate of +The pairwise Knockouts in East Charlie + + align:start position:0% +The pairwise Knockouts in East Charlie + + + align:start position:0% +The pairwise Knockouts in East Charlie +Boon at Toronto it's an amazing data set + + align:start position:0% +Boon at Toronto it's an amazing data set + + + align:start position:0% +Boon at Toronto it's an amazing data set +okay but right this is a sorry this is a + + align:start position:0% +okay but right this is a sorry this is a + + + align:start position:0% +okay but right this is a sorry this is a +simpler one right so this is just if we + + align:start position:0% +simpler one right so this is just if we + + + align:start position:0% +simpler one right so this is just if we +make a histogram of the growth rate of + + align:start position:0% +make a histogram of the growth rate of + + + align:start position:0% +make a histogram of the growth rate of +eoli all possible all 10 million + + align:start position:0% +eoli all possible all 10 million + + + align:start position:0% +eoli all possible all 10 million +possible point mutations in equal what + + align:start position:0% +possible point mutations in equal what + + + align:start position:0% +possible point mutations in equal what +do you think it's going to look + + align:start position:0% + + + + align:start position:0% + +like all right and I'm going to come by + + align:start position:0% +like all right and I'm going to come by + + + align:start position:0% +like all right and I'm going to come by +and if I don't see a distribution drawn + + align:start position:0% +and if I don't see a distribution drawn + + + align:start position:0% +and if I don't see a distribution drawn +on your sheet of paper then you can um + + align:start position:0% +on your sheet of paper then you can um + + + align:start position:0% +on your sheet of paper then you can um +you you'll get to draw it up here on the + + align:start position:0% +you you'll get to draw it up here on the + + + align:start position:0% +you you'll get to draw it up here on the +board for + + align:start position:0% +board for + + + align:start position:0% +board for +all of us okay + + align:start position:0% + + + + align:start position:0% + +um totally a distribution okay + + align:start position:0% + + + + align:start position:0% + +okay all + + align:start position:0% + + + + align:start position:0% + +right all right yeah what I find + + align:start position:0% +right all right yeah what I find + + + align:start position:0% +right all right yeah what I find +interesting about this exercise is that + + align:start position:0% +interesting about this exercise is that + + + align:start position:0% +interesting about this exercise is that +you get uh all possible + + align:start position:0% +you get uh all possible + + + align:start position:0% +you get uh all possible +distributions which is um no but it's + + align:start position:0% +distributions which is um no but it's + + + align:start position:0% +distributions which is um no but it's +funny because it's it's like a super + + align:start position:0% +funny because it's it's like a super + + + align:start position:0% +funny because it's it's like a super +basic question right um and somehow we + + align:start position:0% +basic question right um and somehow we + + + align:start position:0% +basic question right um and somehow we +don't necessarily think about it or + + align:start position:0% +don't necessarily think about it or + + + align:start position:0% +don't necessarily think about it or +whatnot right um all right can somebody + + align:start position:0% +whatnot right um all right can somebody + + + align:start position:0% +whatnot right um all right can somebody +throw out kind of what they think maybe + + align:start position:0% +throw out kind of what they think maybe + + + align:start position:0% +throw out kind of what they think maybe +should be going on + + align:start position:0% +should be going on + + + align:start position:0% +should be going on +yeah large + + align:start position:0% +yeah large + + + align:start position:0% +yeah large +Z okay right so it could be just + + align:start position:0% +Z okay right so it could be just + + + align:start position:0% +Z okay right so it could be just +that all right so it could be that + + align:start position:0% +that all right so it could be that + + + align:start position:0% +that all right so it could be that +they're all + + align:start position:0% +they're all + + + align:start position:0% +they're all +here you know most + + align:start position:0% +here you know most + + + align:start position:0% +here you know most +will large + + align:start position:0% +will large + + + align:start position:0% +will large +Frac right so it could be that a large + + align:start position:0% +Frac right so it could be that a large + + + align:start position:0% +Frac right so it could be that a large +fraction of these point mutations and + + align:start position:0% +fraction of these point mutations and + + + align:start position:0% +fraction of these point mutations and +the cell is just dead right yeah so this + + align:start position:0% +the cell is just dead right yeah so this + + + align:start position:0% +the cell is just dead right yeah so this +is this is what you call a pessimistic + + align:start position:0% +is this is what you call a pessimistic + + + align:start position:0% +is this is what you call a pessimistic +view of nature or of life you know he + + align:start position:0% +view of nature or of life you know he + + + align:start position:0% +view of nature or of life you know he +has trouble crossing the street because + + align:start position:0% +has trouble crossing the street because + + + align:start position:0% +has trouble crossing the street because +he's never sure you yeah what do you + + align:start position:0% +he's never sure you yeah what do you + + + align:start position:0% +he's never sure you yeah what do you +think I would actually think that + + align:start position:0% +think I would actually think that + + + align:start position:0% +think I would actually think that +there's a much larger traction where all + + align:start position:0% +there's a much larger traction where all + + + align:start position:0% +there's a much larger traction where all +of where it's exactly the same you've + + align:start position:0% +of where it's exactly the same you've + + + align:start position:0% +of where it's exactly the same you've +got a lot of Prim mutations that are + + align:start position:0% +got a lot of Prim mutations that are + + + align:start position:0% +got a lot of Prim mutations that are +just substitutions of yeah okay so lots + + align:start position:0% +just substitutions of yeah okay so lots + + + align:start position:0% +just substitutions of yeah okay so lots +of them maybe okay so may all right so + + align:start position:0% +of them maybe okay so may all right so + + + align:start position:0% +of them maybe okay so may all right so +all right so these are the two polar + + align:start position:0% +all right so these are the two polar + + + align:start position:0% +all right so these are the two polar +views of the world right that nothing + + align:start position:0% +views of the world right that nothing + + + align:start position:0% +views of the world right that nothing +matters or you're all dead + + align:start position:0% +matters or you're all dead + + + align:start position:0% +matters or you're all dead +um I think you can reconcile them I + + align:start position:0% +um I think you can reconcile them I + + + align:start position:0% +um I think you can reconcile them I +think you can say okay well now now I + + align:start position:0% +think you can say okay well now now I + + + align:start position:0% +think you can say okay well now now I +think you're being too uh how how we + + align:start position:0% +think you're being too uh how how we + + + align:start position:0% +think you're being too uh how how we +reconcile them so we know that there's + + align:start position:0% +reconcile them so we know that there's + + + align:start position:0% +reconcile them so we know that there's +the thiras right sure and so there's + + align:start position:0% +the thiras right sure and so there's + + + align:start position:0% +the thiras right sure and so there's +probably like at least one third of them + + align:start position:0% +probably like at least one third of them + + + align:start position:0% +probably like at least one third of them +where it just doesn't matter at all + + align:start position:0% +where it just doesn't matter at all + + + align:start position:0% +where it just doesn't matter at all +the same get the same code yeah yeah um + + align:start position:0% +the same get the same code yeah yeah um + + + align:start position:0% +the same get the same code yeah yeah um +although there are cases actually where + + align:start position:0% +although there are cases actually where + + + align:start position:0% +although there are cases actually where +even silent mutations end up changing + + align:start position:0% +even silent mutations end up changing + + + align:start position:0% +even silent mutations end up changing +protein expression level but yeah no + + align:start position:0% +protein expression level but yeah no + + + align:start position:0% +protein expression level but yeah no +right it's it I don't know if this + + align:start position:0% +right it's it I don't know if this + + + align:start position:0% +right it's it I don't know if this +reconciles the two views of the world + + align:start position:0% +reconciles the two views of the world + + + align:start position:0% +reconciles the two views of the world +but um right you know and then I'd say + + align:start position:0% +but um right you know and then I'd say + + + align:start position:0% +but um right you know and then I'd say +um you know and then some right so some + + align:start position:0% +um you know and then some right so some + + + align:start position:0% +um you know and then some right so some +people have drawn + + align:start position:0% +people have drawn + + + align:start position:0% +people have drawn +um you know things that look like this + + align:start position:0% +um you know things that look like this + + + align:start position:0% +um you know things that look like this +some or some people have drawn things + + align:start position:0% +some or some people have drawn things + + + align:start position:0% +some or some people have drawn things +that look like this sometime yeah so I'd + + align:start position:0% +that look like this sometime yeah so I'd + + + align:start position:0% +that look like this sometime yeah so I'd +say we have and we have a uniform + + align:start position:0% +say we have and we have a uniform + + + align:start position:0% +say we have and we have a uniform +distribution um you know if you're going + + align:start position:0% +distribution um you know if you're going + + + align:start position:0% +distribution um you know if you're going +to if you're going to make a null model + + align:start position:0% +to if you're going to make a null model + + + align:start position:0% +to if you're going to make a null model +I mean you I don't know okay right so + + align:start position:0% +I mean you I don't know okay right so + + + align:start position:0% +I mean you I don't know okay right so +IID say we we have enough information to + + align:start position:0% +IID say we we have enough information to + + + align:start position:0% +IID say we we have enough information to +say that something about what this thing + + align:start position:0% +say that something about what this thing + + + align:start position:0% +say that something about what this thing +should look like okay um right so first + + align:start position:0% +should look like okay um right so first + + + align:start position:0% +should look like okay um right so first +of all um you know some fraction of + + align:start position:0% +of all um you know some fraction of + + + align:start position:0% +of all um you know some fraction of +genes are indeed essential so you know + + align:start position:0% +genes are indeed essential so you know + + + align:start position:0% +genes are indeed essential so you know +we know that if you remove you know 10 + + align:start position:0% +we know that if you remove you know 10 + + + align:start position:0% +we know that if you remove you know 10 +20% of Gene you know for 10 or to 20% of + + align:start position:0% +20% of Gene you know for 10 or to 20% of + + + align:start position:0% +20% of Gene you know for 10 or to 20% of +the genes if you remove it the cell is + + align:start position:0% +the genes if you remove it the cell is + + + align:start position:0% +the genes if you remove it the cell is +dead okay that doesn't mean that 10 to + + align:start position:0% +dead okay that doesn't mean that 10 to + + + align:start position:0% +dead okay that doesn't mean that 10 to +20% of point mutations will lead to a + + align:start position:0% +20% of point mutations will lead to a + + + align:start position:0% +20% of point mutations will lead to a +lethal U lethal phenotype but it means + + align:start position:0% +lethal U lethal phenotype but it means + + + align:start position:0% +lethal U lethal phenotype but it means +that if you if you do um inactivate or + + align:start position:0% +that if you if you do um inactivate or + + + align:start position:0% +that if you if you do um inactivate or +knock out that uh Gene then it will be + + align:start position:0% +knock out that uh Gene then it will be + + + align:start position:0% +knock out that uh Gene then it will be +lethal okay so that means that there are + + align:start position:0% +lethal okay so that means that there are + + + align:start position:0% +lethal okay so that means that there are +indeed some set + + align:start position:0% +indeed some set + + + align:start position:0% +indeed some set +of U these point mutations that are + + align:start position:0% +of U these point mutations that are + + + align:start position:0% +of U these point mutations that are +going to be lethal but it's going to + + align:start position:0% +going to be lethal but it's going to + + + align:start position:0% +going to be lethal but it's going to +be small I you know I and I I don't know + + align:start position:0% +be small I you know I and I I don't know + + + align:start position:0% +be small I you know I and I I don't know +what the actual number would be but you + + align:start position:0% +what the actual number would be but you + + + align:start position:0% +what the actual number would be but you +know maybe 1 and 10 to + + align:start position:0% +know maybe 1 and 10 to + + + align:start position:0% +know maybe 1 and 10 to +the four + + align:start position:0% +the four + + + align:start position:0% +the four +something something small right because + + align:start position:0% +something something small right because + + + align:start position:0% +something something small right because +it might you know because it's probably + + align:start position:0% +it might you know because it's probably + + + align:start position:0% +it might you know because it's probably +only 10% of the locations on the gene + + align:start position:0% +only 10% of the locations on the gene + + + align:start position:0% +only 10% of the locations on the gene +would actually knock it out okay I'm + + align:start position:0% +would actually knock it out okay I'm + + + align:start position:0% +would actually knock it out okay I'm +making up that number uh the pro the + + align:start position:0% +making up that number uh the pro the + + + align:start position:0% +making up that number uh the pro the +protein guys would have a much better + + align:start position:0% +protein guys would have a much better + + + align:start position:0% +protein guys would have a much better +sense but it's going to be it's going to + + align:start position:0% +sense but it's going to be it's going to + + + align:start position:0% +sense but it's going to be it's going to +be a small number it might only be 1% of + + align:start position:0% +be a small number it might only be 1% of + + + align:start position:0% +be a small number it might only be 1% of +the mutations actually would actually + + align:start position:0% +the mutations actually would actually + + + align:start position:0% +the mutations actually would actually +would actually knock out function of the + + align:start position:0% +would actually knock out function of the + + + align:start position:0% +would actually knock out function of the +protein right and then um not all of the + + align:start position:0% +protein right and then um not all of the + + + align:start position:0% +protein right and then um not all of the +genome actually codes for proteins right + + align:start position:0% +genome actually codes for proteins right + + + align:start position:0% +genome actually codes for proteins right +so you start multiplying small numbers + + align:start position:0% +so you start multiplying small numbers + + + align:start position:0% +so you start multiplying small numbers +together and you get something that's + + align:start position:0% +together and you get something that's + + + align:start position:0% +together and you get something that's +rather small but there but there will be + + align:start position:0% +rather small but there but there will be + + + align:start position:0% +rather small but there but there will be +some number mutations there uh however + + align:start position:0% +some number mutations there uh however + + + align:start position:0% +some number mutations there uh however +the vast majority of mutations will have + + align:start position:0% +the vast majority of mutations will have + + + align:start position:0% +the vast majority of mutations will have +no measurable Fitness effect okay so + + align:start position:0% +no measurable Fitness effect okay so + + + align:start position:0% +no measurable Fitness effect okay so +indeed this thing kind of Peaks + + align:start position:0% +indeed this thing kind of Peaks + + + align:start position:0% +indeed this thing kind of Peaks +here um and and then rather sharply + + align:start position:0% +here um and and then rather sharply + + + align:start position:0% +here um and and then rather sharply +comes down this is on a linear scale or + + align:start position:0% +comes down this is on a linear scale or + + + align:start position:0% +comes down this is on a linear scale or +something like that right so the width + + align:start position:0% +something like that right so the width + + + align:start position:0% +something like that right so the width +might indeed be you know a few + + align:start position:0% + + + + align:start position:0% + +percent um but actually you know + + align:start position:0% +percent um but actually you know + + + align:start position:0% +percent um but actually you know +probably even less maybe 1% or half you + + align:start position:0% +probably even less maybe 1% or half you + + + align:start position:0% +probably even less maybe 1% or half you +know something small + + align:start position:0% +know something small + + + align:start position:0% +know something small +yeah howed is yeah uh so it's on a + + align:start position:0% +yeah howed is yeah uh so it's on a + + + align:start position:0% +yeah howed is yeah uh so it's on a +linear scale it doesn't look skewed on a + + align:start position:0% +linear scale it doesn't look skewed on a + + + align:start position:0% +linear scale it doesn't look skewed on a +log scale I think it does I mean the + + align:start position:0% +log scale I think it does I mean the + + + align:start position:0% +log scale I think it does I mean the +sense if if you um if you plot log + + align:start position:0% +sense if if you um if you plot log + + + align:start position:0% +sense if if you um if you plot log +frequency on this axis then there's a + + align:start position:0% +frequency on this axis then there's a + + + align:start position:0% +frequency on this axis then there's a +longer tail on the left than on the + + align:start position:0% +longer tail on the left than on the + + + align:start position:0% +longer tail on the left than on the +right but I'd say on a linear scale it's + + align:start position:0% +right but I'd say on a linear scale it's + + + align:start position:0% +right but I'd say on a linear scale it's +it's just pretty sharp function there so + + align:start position:0% +it's just pretty sharp function there so + + + align:start position:0% +it's just pretty sharp function there so +people have measured that all right so + + align:start position:0% +people have measured that all right so + + + align:start position:0% +people have measured that all right so +people have measured certainly for all + + align:start position:0% +people have measured certainly for all + + + align:start position:0% +people have measured certainly for all +the gene Knockouts we've we have + + align:start position:0% +the gene Knockouts we've we have + + + align:start position:0% +the gene Knockouts we've we have +measured this and that's that's things + + align:start position:0% +measured this and that's that's things + + + align:start position:0% +measured this and that's that's things +even that distribution is is sharply + + align:start position:0% +even that distribution is is sharply + + + align:start position:0% +even that distribution is is sharply +right so the point mutation distribution + + align:start position:0% +right so the point mutation distribution + + + align:start position:0% +right so the point mutation distribution +is going to be even more even more Ely + + align:start position:0% + + + + align:start position:0% + +Peak yeah yeah so so for most genes at + + align:start position:0% +Peak yeah yeah so so for most genes at + + + align:start position:0% +Peak yeah yeah so so for most genes at +least in many environments right and of + + align:start position:0% +least in many environments right and of + + + align:start position:0% +least in many environments right and of +course you it depends on what + + align:start position:0% +course you it depends on what + + + align:start position:0% +course you it depends on what +environment you measure then but for + + align:start position:0% +environment you measure then but for + + + align:start position:0% +environment you measure then but for +most genes you can you can knock them + + align:start position:0% +most genes you can you can knock them + + + align:start position:0% +most genes you can you can knock them +out certainly in rich media most gen you + + align:start position:0% +out certainly in rich media most gen you + + + align:start position:0% +out certainly in rich media most gen you +can knock out + + align:start position:0% +can knock out + + + align:start position:0% +can knock out +right okay right so this is + + align:start position:0% +right okay right so this is + + + align:start position:0% +right okay right so this is +um you know and then of course there you + + align:start position:0% +um you know and then of course there you + + + align:start position:0% +um you know and then of course there you +know yeah this as I said might be one + + align:start position:0% +know yeah this as I said might be one + + + align:start position:0% +know yeah this as I said might be one +10 to + + align:start position:0% + + + + align:start position:0% + +Theus 3 4 okay um you know it's I I + + align:start position:0% +Theus 3 4 okay um you know it's I I + + + align:start position:0% +Theus 3 4 okay um you know it's I I +might be off by a couple orders of + + align:start position:0% +might be off by a couple orders of + + + align:start position:0% +might be off by a couple orders of +magnitude okay but the point is that + + align:start position:0% +magnitude okay but the point is that + + + align:start position:0% +magnitude okay but the point is that +this is um it's it's a small fraction + + align:start position:0% +this is um it's it's a small fraction + + + align:start position:0% +this is um it's it's a small fraction +over here most most are here and there + + align:start position:0% +over here most most are here and there + + + align:start position:0% +over here most most are here and there +will be some point mutations that come + + align:start position:0% +will be some point mutations that come + + + align:start position:0% +will be some point mutations that come +down here but you know on a linear scale + + align:start position:0% +down here but you know on a linear scale + + + align:start position:0% +down here but you know on a linear scale +they're going to be it's going to be + + align:start position:0% +they're going to be it's going to be + + + align:start position:0% +they're going to be it's going to be +very small + + align:start position:0% +very small + + + align:start position:0% +very small +okay um okay now from the standpoint of + + align:start position:0% +okay um okay now from the standpoint of + + + align:start position:0% +okay um okay now from the standpoint of +a population evolving to a new + + align:start position:0% +a population evolving to a new + + + align:start position:0% +a population evolving to a new +environment which mutation are we most + + align:start position:0% +environment which mutation are we most + + + align:start position:0% +environment which mutation are we most +interested + + align:start position:0% +interested + + + align:start position:0% +interested +in the beneficial mutations right so + + align:start position:0% +in the beneficial mutations right so + + + align:start position:0% +in the beneficial mutations right so +we're most interested in uh in these + + align:start position:0% +we're most interested in uh in these + + + align:start position:0% +we're most interested in uh in these +guys okay um and indeed this is the + + align:start position:0% +guys okay um and indeed this is the + + + align:start position:0% +guys okay um and indeed this is the +distribution that that um heggerness and + + align:start position:0% +distribution that that um heggerness and + + + align:start position:0% +distribution that that um heggerness and +koni set out to try and measure in that + + align:start position:0% +koni set out to try and measure in that + + + align:start position:0% +koni set out to try and measure in that +experiment um that we just read about + + align:start position:0% +experiment um that we just read about + + + align:start position:0% +experiment um that we just read about +last night okay so he wanted to know if + + align:start position:0% +last night okay so he wanted to know if + + + align:start position:0% +last night okay so he wanted to know if +you plot if you kind of zoom in here + + align:start position:0% +you plot if you kind of zoom in here + + + align:start position:0% +you plot if you kind of zoom in here +because remember this this is even + + align:start position:0% +because remember this this is even + + + align:start position:0% +because remember this this is even +narrower than I've actually drawn right + + align:start position:0% +narrower than I've actually drawn right + + + align:start position:0% +narrower than I've actually drawn right +um but this distribtion + + align:start position:0% +um but this distribtion + + + align:start position:0% +um but this distribtion +the probability of a beneficial mutation + + align:start position:0% +the probability of a beneficial mutation + + + align:start position:0% +the probability of a beneficial mutation +of magnitude s s here is zero s um it's + + align:start position:0% +of magnitude s s here is zero s um it's + + + align:start position:0% +of magnitude s s here is zero s um it's +going + + align:start position:0% +going + + + align:start position:0% +going +to you know it's going to do + + align:start position:0% +to you know it's going to do + + + align:start position:0% +to you know it's going to do +something right many mutations that are + + align:start position:0% +something right many mutations that are + + + align:start position:0% +something right many mutations that are +nearly neutral but it's going to fall + + align:start position:0% +nearly neutral but it's going to fall + + + align:start position:0% +nearly neutral but it's going to fall +off in some way and they wanted to try + + align:start position:0% +off in some way and they wanted to try + + + align:start position:0% +off in some way and they wanted to try +and measure this right you know how many + + align:start position:0% +and measure this right you know how many + + + align:start position:0% +and measure this right you know how many +mutations caner a 2% Advantage 4% you + + align:start position:0% +mutations caner a 2% Advantage 4% you + + + align:start position:0% +mutations caner a 2% Advantage 4% you +know for this particular equ strain in + + align:start position:0% +know for this particular equ strain in + + + align:start position:0% +know for this particular equ strain in +that particular + + align:start position:0% +that particular + + + align:start position:0% +that particular +environment okay but it turned out being + + align:start position:0% +environment okay but it turned out being + + + align:start position:0% +environment okay but it turned out being +difficult to measure + + align:start position:0% +difficult to measure + + + align:start position:0% +difficult to measure +right and and what was the reason that + + align:start position:0% +right and and what was the reason that + + + align:start position:0% +right and and what was the reason that +they gave for why it was difficult to + + align:start position:0% + + + + align:start position:0% + +measure somebody anybody + + align:start position:0% + + + + align:start position:0% + +please yes okay but the equivalence + + align:start position:0% +please yes okay but the equivalence + + + align:start position:0% +please yes okay but the equivalence +principle doesn't say that they're all + + align:start position:0% +principle doesn't say that they're all + + + align:start position:0% +principle doesn't say that they're all +equivalent + + align:start position:0% + + + + align:start position:0% + +necessarily they each have + + align:start position:0% +necessarily they each have + + + align:start position:0% +necessarily they each have +their yeah you keep parameters for each + + align:start position:0% +their yeah you keep parameters for each + + + align:start position:0% +their yeah you keep parameters for each +of them that they will give you the + + align:start position:0% +of them that they will give you the + + + align:start position:0% +of them that they will give you the +same okay that's right right so what + + align:start position:0% +same okay that's right right so what + + + align:start position:0% +same okay that's right right so what +they found was that different underlying + + align:start position:0% +they found was that different underlying + + + align:start position:0% +they found was that different underlying +distributions this prob distribution for + + align:start position:0% +distributions this prob distribution for + + + align:start position:0% +distributions this prob distribution for +beneficial limitations function of s + + align:start position:0% +beneficial limitations function of s + + + align:start position:0% +beneficial limitations function of s +different underlying distributions could + + align:start position:0% +different underlying distributions could + + + align:start position:0% +different underlying distributions could +give you the same final output in their + + align:start position:0% +give you the same final output in their + + + align:start position:0% +give you the same final output in their +measurements okay but why was + + align:start position:0% + + + + align:start position:0% + +that yeah + + align:start position:0% + + + + align:start position:0% + +John right so you can only measure what + + align:start position:0% +John right so you can only measure what + + + align:start position:0% +John right so you can only measure what +fixes or what become uh or becomes + + align:start position:0% +fixes or what become uh or becomes + + + align:start position:0% +fixes or what become uh or becomes +significant fractional population 10% + + align:start position:0% +significant fractional population 10% + + + align:start position:0% +significant fractional population 10% +you know only measure what fixes or + + align:start position:0% + + + + align:start position:0% + +grows okay and what does that + + align:start position:0% +grows okay and what does that + + + align:start position:0% +grows okay and what does that +mean + + align:start position:0% +mean + + + align:start position:0% +mean +well it means that you're not + + align:start position:0% +well it means that you're not + + + align:start position:0% +well it means that you're not +prob right it means that we're not + + align:start position:0% +prob right it means that we're not + + + align:start position:0% +prob right it means that we're not +probing that distribution and why + + align:start position:0% + + + + align:start position:0% + +not yeah okay but yeah but why is it + + align:start position:0% +not yeah okay but yeah but why is it + + + align:start position:0% +not yeah okay but yeah but why is it +that we only see part of this + + align:start position:0% +that we only see part of this + + + align:start position:0% +that we only see part of this +distribution what what was there I mean + + align:start position:0% +distribution what what was there I mean + + + align:start position:0% +distribution what what was there I mean +don't see out we don't see the ones that + + align:start position:0% +don't see out we don't see the ones that + + + align:start position:0% +don't see out we don't see the ones that +die out and and and why is it that they + + align:start position:0% +die out and and and why is it that they + + + align:start position:0% +die out and and and why is it that they +die out or why is it that + + align:start position:0% +die out or why is it that + + + align:start position:0% +die out or why is it that +they okay right okay yeah so sto yeah um + + align:start position:0% +they okay right okay yeah so sto yeah um + + + align:start position:0% +they okay right okay yeah so sto yeah um +yes so the the effect of stochastic + + align:start position:0% +yes so the the effect of stochastic + + + align:start position:0% +yes so the the effect of stochastic +Extinction is very relevant here and I + + align:start position:0% +Extinction is very relevant here and I + + + align:start position:0% +Extinction is very relevant here and I +think that in this paper they a little + + align:start position:0% +think that in this paper they a little + + + align:start position:0% +think that in this paper they a little +bit underplay that aspect of it right + + align:start position:0% +bit underplay that aspect of it right + + + align:start position:0% +bit underplay that aspect of it right +because they're primarily arguing that + + align:start position:0% +because they're primarily arguing that + + + align:start position:0% +because they're primarily arguing that +it was another effect that Led Led to + + align:start position:0% +it was another effect that Led Led to + + + align:start position:0% +it was another effect that Led Led to +this equivalence + + align:start position:0% +this equivalence + + + align:start position:0% +this equivalence +principle right competition yeah clonal + + align:start position:0% +principle right competition yeah clonal + + + align:start position:0% +principle right competition yeah clonal +interference right I mean that's why we + + align:start position:0% +interference right I mean that's why we + + + align:start position:0% +interference right I mean that's why we +spent the last hour talking about clonal + + align:start position:0% +spent the last hour talking about clonal + + + align:start position:0% +spent the last hour talking about clonal +interference right so there their their + + align:start position:0% +interference right so there their their + + + align:start position:0% +interference right so there their their +argument that in this paper was that as + + align:start position:0% +argument that in this paper was that as + + + align:start position:0% +argument that in this paper was that as +a result of colonal interference + + align:start position:0% +a result of colonal interference + + + align:start position:0% +a result of colonal interference +competition between these different + + align:start position:0% +competition between these different + + + align:start position:0% +competition between these different +lineages then the distribution of + + align:start position:0% +lineages then the distribution of + + + align:start position:0% +lineages then the distribution of +Fitness effects that you measure that + + align:start position:0% +Fitness effects that you measure that + + + align:start position:0% +Fitness effects that you measure that +fix is not the distrib that was the + + align:start position:0% +fix is not the distrib that was the + + + align:start position:0% +fix is not the distrib that was the +underlying + + align:start position:0% +underlying + + + align:start position:0% +underlying +distribution okay because less fit + + align:start position:0% +distribution okay because less fit + + + align:start position:0% +distribution okay because less fit +mutations less fit beneficial mutations + + align:start position:0% +mutations less fit beneficial mutations + + + align:start position:0% +mutations less fit beneficial mutations +get out competed okay but there's a very + + align:start position:0% +get out competed okay but there's a very + + + align:start position:0% +get out competed okay but there's a very +important question which is let's + + align:start position:0% +important question which is let's + + + align:start position:0% +important question which is let's +imagine that we have let's have mu go to + + align:start position:0% +imagine that we have let's have mu go to + + + align:start position:0% +imagine that we have let's have mu go to +zero okay or we go to small populations + + align:start position:0% +zero okay or we go to small populations + + + align:start position:0% +zero okay or we go to small populations +let's let's uh let's uh let's say that + + align:start position:0% +let's let's uh let's uh let's say that + + + align:start position:0% +let's let's uh let's uh let's say that +uh after reading his paper I said okay + + align:start position:0% +uh after reading his paper I said okay + + + align:start position:0% +uh after reading his paper I said okay +well yeah because of Clone interference + + align:start position:0% +well yeah because of Clone interference + + + align:start position:0% +well yeah because of Clone interference +I can't measure this probability + + align:start position:0% +I can't measure this probability + + + align:start position:0% +I can't measure this probability +distribution in the setup that he used + + align:start position:0% +distribution in the setup that he used + + + align:start position:0% +distribution in the setup that he used +but maybe if I go to small population + + align:start position:0% +but maybe if I go to small population + + + align:start position:0% +but maybe if I go to small population +sizes or I reduce the mutation rate + + align:start position:0% +sizes or I reduce the mutation rate + + + align:start position:0% +sizes or I reduce the mutation rate +somehow magic okay then would this allow + + align:start position:0% +somehow magic okay then would this allow + + + align:start position:0% +somehow magic okay then would this allow +me to measure that distribution right so + + align:start position:0% +me to measure that distribution right so + + + align:start position:0% +me to measure that distribution right so +I'm going to ask you guys to vote so + + align:start position:0% +I'm going to ask you guys to vote so + + + align:start position:0% +I'm going to ask you guys to vote so +let's say I experimentally have mu go to + + align:start position:0% +let's say I experimentally have mu go to + + + align:start position:0% +let's say I experimentally have mu go to +zero does this mean that when I then go + + align:start position:0% +zero does this mean that when I then go + + + align:start position:0% +zero does this mean that when I then go +do my right cfp + + align:start position:0% +do my right cfp + + + align:start position:0% +do my right cfp +yfp right they're 50/50 and then you + + align:start position:0% +yfp right they're 50/50 and then you + + + align:start position:0% +yfp right they're 50/50 and then you +start doing this and we measure the + + align:start position:0% +start doing this and we measure the + + + align:start position:0% +start doing this and we measure the +slope to get S right + + align:start position:0% +slope to get S right + + + align:start position:0% +slope to get S right +just like in this experiment okay will I + + align:start position:0% +just like in this experiment okay will I + + + align:start position:0% +just like in this experiment okay will I +extract if I plot the distribution of + + align:start position:0% +extract if I plot the distribution of + + + align:start position:0% +extract if I plot the distribution of +resulting + + align:start position:0% + + + + align:start position:0% + +s's okay no colonal interference anymore + + align:start position:0% +s's okay no colonal interference anymore + + + align:start position:0% +s's okay no colonal interference anymore +right because I've set mu equal to zero + + align:start position:0% +right because I've set mu equal to zero + + + align:start position:0% +right because I've set mu equal to zero +so this thing goes to Infinity right do + + align:start position:0% +so this thing goes to Infinity right do + + + align:start position:0% +so this thing goes to Infinity right do +I recover this uh the underlying + + align:start position:0% +I recover this uh the underlying + + + align:start position:0% +I recover this uh the underlying +distribution okay ready okay so PB + + align:start position:0% +distribution okay ready okay so PB + + + align:start position:0% +distribution okay ready okay so PB +measured + + align:start position:0% +measured + + + align:start position:0% +measured +is it as a function of s is it equal to + + align:start position:0% +is it as a function of s is it equal to + + + align:start position:0% +is it as a function of s is it equal to +the underlying the true one question + + align:start position:0% + + + + align:start position:0% + +mark all right I'm going to give you 15 + + align:start position:0% +mark all right I'm going to give you 15 + + + align:start position:0% +mark all right I'm going to give you 15 +seconds to think about + + align:start position:0% + + + + align:start position:0% + +this + + align:start position:0% + + + + align:start position:0% + +all right ready three two + + align:start position:0% +all right ready three two + + + align:start position:0% +all right ready three two +one all right so we have many uh you + + align:start position:0% +one all right so we have many uh you + + + align:start position:0% +one all right so we have many uh you +know i' say majority of NOS okay and can + + align:start position:0% +know i' say majority of NOS okay and can + + + align:start position:0% +know i' say majority of NOS okay and can +somebody say why + + align:start position:0% +somebody say why + + + align:start position:0% +somebody say why +not we can only see the established mut + + align:start position:0% +not we can only see the established mut + + + align:start position:0% +not we can only see the established mut +that's right because even if you don't + + align:start position:0% +that's right because even if you don't + + + align:start position:0% +that's right because even if you don't +have clonal interference you still only + + align:start position:0% +have clonal interference you still only + + + align:start position:0% +have clonal interference you still only +see the mutations that survive + + align:start position:0% +see the mutations that survive + + + align:start position:0% +see the mutations that survive +stochastic Extinction okay and I think + + align:start position:0% +stochastic Extinction okay and I think + + + align:start position:0% +stochastic Extinction okay and I think +this is a really important point that at + + align:start position:0% +this is a really important point that at + + + align:start position:0% +this is a really important point that at +least in a first reading of the p paper + + align:start position:0% +least in a first reading of the p paper + + + align:start position:0% +least in a first reading of the p paper +you might not realize yeah + + align:start position:0% + + + + align:start position:0% + +John that's right so in principle we + + align:start position:0% +John that's right so in principle we + + + align:start position:0% +John that's right so in principle we +know that it it it that this probably + + align:start position:0% +know that it it it that this probably + + + align:start position:0% +know that it it it that this probably +survival goes as s right um but I'm just + + align:start position:0% +survival goes as s right um but I'm just + + + align:start position:0% +survival goes as s right um but I'm just +but you end up losing a fair amount of + + align:start position:0% +but you end up losing a fair amount of + + + align:start position:0% +but you end up losing a fair amount of +information right so for example let's + + align:start position:0% +information right so for example let's + + + align:start position:0% +information right so for example let's +say that this thing is an + + align:start position:0% +say that this thing is an + + + align:start position:0% +say that this thing is an +exponential okay so this is p b of s + + align:start position:0% +exponential okay so this is p b of s + + + align:start position:0% +exponential okay so this is p b of s +let's just say I it's an exponential um + + align:start position:0% +let's just say I it's an exponential um + + + align:start position:0% +let's just say I it's an exponential um +and indeed from some ideas from extreme + + align:start position:0% +and indeed from some ideas from extreme + + + align:start position:0% +and indeed from some ideas from extreme +value Theory there are arguments that + + align:start position:0% +value Theory there are arguments that + + + align:start position:0% +value Theory there are arguments that +that maybe this should be an exponential + + align:start position:0% +that maybe this should be an exponential + + + align:start position:0% +that maybe this should be an exponential +okay and if you're curious about this + + align:start position:0% +okay and if you're curious about this + + + align:start position:0% +okay and if you're curious about this +come and ask me after class okay all + + align:start position:0% +come and ask me after class okay all + + + align:start position:0% +come and ask me after class okay all +right but let's just imagine that this + + align:start position:0% +right but let's just imagine that this + + + align:start position:0% +right but let's just imagine that this +thing is exponential U now the question + + align:start position:0% +thing is exponential U now the question + + + align:start position:0% +thing is exponential U now the question +is what would we actually + + align:start position:0% +is what would we actually + + + align:start position:0% +is what would we actually +measure in the limit of in this + + align:start position:0% +measure in the limit of in this + + + align:start position:0% +measure in the limit of in this +experiment in the absence of clonal + + align:start position:0% + + + + align:start position:0% + +interference right would we measure a + + align:start position:0% +interference right would we measure a + + + align:start position:0% +interference right would we measure a +distribution that would be would the + + align:start position:0% +distribution that would be would the + + + align:start position:0% +distribution that would be would the +distribution + + align:start position:0% +distribution + + + align:start position:0% +distribution +be maximal at zero or at some other + + align:start position:0% +be maximal at zero or at some other + + + align:start position:0% +be maximal at zero or at some other +value + + align:start position:0% + + + + align:start position:0% + +verbally zero or other value ready three + + align:start position:0% +verbally zero or other value ready three + + + align:start position:0% +verbally zero or other value ready three +2 one other value right and indeed the + + align:start position:0% +2 one other value right and indeed the + + + align:start position:0% +2 one other value right and indeed the +probability of surviving Extinction + + align:start position:0% +probability of surviving Extinction + + + align:start position:0% +probability of surviving Extinction +remember this X1 goes as s means that + + align:start position:0% +remember this X1 goes as s means that + + + align:start position:0% +remember this X1 goes as s means that +the distribution you actually measure + + align:start position:0% +the distribution you actually measure + + + align:start position:0% +the distribution you actually measure +will start at zero grow + + align:start position:0% +will start at zero grow + + + align:start position:0% +will start at zero grow +linearly okay and then uh and then fall + + align:start position:0% +linearly okay and then uh and then fall + + + align:start position:0% +linearly okay and then uh and then fall +off okay so this distribution is + + align:start position:0% +off okay so this distribution is + + + align:start position:0% +off okay so this distribution is +essentially like this distribution of + + align:start position:0% +essentially like this distribution of + + + align:start position:0% +essentially like this distribution of +the convolution of two + + align:start position:0% +the convolution of two + + + align:start position:0% +the convolution of two +exponentials + + align:start position:0% +exponentials + + + align:start position:0% +exponentials +okay where um this thing should this + + align:start position:0% +okay where um this thing should this + + + align:start position:0% +okay where um this thing should this +thing goes up linearly and then and then + + align:start position:0% +thing goes up linearly and then and then + + + align:start position:0% +thing goes up linearly and then and then +curves off okay so I think that a very + + align:start position:0% +curves off okay so I think that a very + + + align:start position:0% +curves off okay so I think that a very +important point to realize in all this + + align:start position:0% +important point to realize in all this + + + align:start position:0% +important point to realize in all this +is that this is p this is prob + + align:start position:0% +is that this is p this is prob + + + align:start position:0% +is that this is p this is prob +distribution that's + + align:start position:0% +distribution that's + + + align:start position:0% +distribution that's +measured as a function of s with no + + align:start position:0% +measured as a function of s with no + + + align:start position:0% +measured as a function of s with no +colonal interference + + align:start position:0% +colonal interference + + + align:start position:0% +colonal interference +right right so the statement is that + + align:start position:0% +right right so the statement is that + + + align:start position:0% +right right so the statement is that +even if you don't have any colonal + + align:start position:0% +even if you don't have any colonal + + + align:start position:0% +even if you don't have any colonal +interference already you're going to + + align:start position:0% +interference already you're going to + + + align:start position:0% +interference already you're going to +measure a peak + + align:start position:0% +measure a peak + + + align:start position:0% +measure a peak +distribution right even if the under + + align:start position:0% +distribution right even if the under + + + align:start position:0% +distribution right even if the under +line distribution is you know it's going + + align:start position:0% +line distribution is you know it's going + + + align:start position:0% +line distribution is you know it's going +to be the underling distribution will be + + align:start position:0% +to be the underling distribution will be + + + align:start position:0% +to be the underling distribution will be +peaked at zero right and then um but the + + align:start position:0% +peaked at zero right and then um but the + + + align:start position:0% +peaked at zero right and then um but the +but what you measure is always going to + + align:start position:0% +but what you measure is always going to + + + align:start position:0% +but what you measure is always going to +be peaked somewhere else and indeed if + + align:start position:0% +be peaked somewhere else and indeed if + + + align:start position:0% +be peaked somewhere else and indeed if +you go and you look in the in the paper + + align:start position:0% +you go and you look in the in the paper + + + align:start position:0% +you go and you look in the in the paper +at the measured Alpha as a function of s + + align:start position:0% +at the measured Alpha as a function of s + + + align:start position:0% +at the measured Alpha as a function of s +what you see is something that looks + + align:start position:0% +what you see is something that looks + + + align:start position:0% +what you see is something that looks +kind of like this so uh it's a little + + align:start position:0% +kind of like this so uh it's a little + + + align:start position:0% +kind of like this so uh it's a little +bit difficult to be absolutely certain + + align:start position:0% +bit difficult to be absolutely certain + + + align:start position:0% +bit difficult to be absolutely certain +what's going on is that in the absence + + align:start position:0% +what's going on is that in the absence + + + align:start position:0% +what's going on is that in the absence +of Clone interference you get this with + + align:start position:0% +of Clone interference you get this with + + + align:start position:0% +of Clone interference you get this with +clone interference let's say you have + + align:start position:0% +clone interference let's say you have + + + align:start position:0% +clone interference let's say you have +two mutations and you want to know okay + + align:start position:0% +two mutations and you want to know okay + + + align:start position:0% +two mutations and you want to know okay +what are you going to measure well you + + align:start position:0% +what are you going to measure well you + + + align:start position:0% +what are you going to measure well you +sample from this distribution twice and + + align:start position:0% +sample from this distribution twice and + + + align:start position:0% +sample from this distribution twice and +you take the larger of the two + + align:start position:0% +you take the larger of the two + + + align:start position:0% +you take the larger of the two +right because this distribution is + + align:start position:0% +right because this distribution is + + + align:start position:0% +right because this distribution is +already the prob distribution of + + align:start position:0% +already the prob distribution of + + + align:start position:0% +already the prob distribution of +mutations that get established right so + + align:start position:0% +mutations that get established right so + + + align:start position:0% +mutations that get established right so +then this is going to grow as + + align:start position:0% +then this is going to grow as + + + align:start position:0% +then this is going to grow as +um as a quadratic here if you have more + + align:start position:0% +um as a quadratic here if you have more + + + align:start position:0% +um as a quadratic here if you have more +clonal interference then this thing + + align:start position:0% +clonal interference then this thing + + + align:start position:0% +clonal interference then this thing +shifts to the right and gets tighter + + align:start position:0% +shifts to the right and gets tighter + + + align:start position:0% +shifts to the right and gets tighter +right so this is the this is kind of the + + align:start position:0% +right so this is the this is kind of the + + + align:start position:0% +right so this is the this is kind of the +process by which you end up with a + + align:start position:0% +process by which you end up with a + + + align:start position:0% +process by which you end up with a +peaked + + align:start position:0% +peaked + + + align:start position:0% +peaked +distribution okay so what we're going to + + align:start position:0% +distribution okay so what we're going to + + + align:start position:0% +distribution okay so what we're going to +do is uh we're going to start uh by the + + align:start position:0% +do is uh we're going to start uh by the + + + align:start position:0% +do is uh we're going to start uh by the +first the first 15 minutes on Tuesday + + align:start position:0% +first the first 15 minutes on Tuesday + + + align:start position:0% +first the first 15 minutes on Tuesday +we'll um we'll talk about this + + align:start position:0% +we'll um we'll talk about this + + + align:start position:0% +we'll um we'll talk about this +experiment uh a bit more uh and then uh + + align:start position:0% +experiment uh a bit more uh and then uh + + + align:start position:0% +experiment uh a bit more uh and then uh +and then we'll go on to think about uh + + align:start position:0% +and then we'll go on to think about uh + + + align:start position:0% +and then we'll go on to think about uh +about Fitness Landscapes and uh and the + + align:start position:0% +about Fitness Landscapes and uh and the + + + align:start position:0% +about Fitness Landscapes and uh and the +rate of evolution if you have any + + align:start position:0% +rate of evolution if you have any + + + align:start position:0% +rate of evolution if you have any +questions about anything that we said uh + + align:start position:0% +questions about anything that we said uh + + + align:start position:0% +questions about anything that we said uh +please come on up okay \ No newline at end of file diff --git a/6UMv4vb4y7c.txt b/6UMv4vb4y7c.txt new file mode 100644 index 0000000000000000000000000000000000000000..49067067c0a3415ac1e70a36799c1904251ee4cc --- /dev/null +++ b/6UMv4vb4y7c.txt @@ -0,0 +1,1387 @@ +align:start position:0% + +we now introduce normal random variables + + align:start position:0% +we now introduce normal random variables + + + align:start position:0% +we now introduce normal random variables +which are also often called Gaussian + + align:start position:0% +which are also often called Gaussian + + + align:start position:0% +which are also often called Gaussian +random variables normal random variables + + align:start position:0% +random variables normal random variables + + + align:start position:0% +random variables normal random variables +are perhaps the most important ones in + + align:start position:0% +are perhaps the most important ones in + + + align:start position:0% +are perhaps the most important ones in +probability theory they play a key role + + align:start position:0% +probability theory they play a key role + + + align:start position:0% +probability theory they play a key role +in the theory of the subject as we will + + align:start position:0% +in the theory of the subject as we will + + + align:start position:0% +in the theory of the subject as we will +see later in this class in the context + + align:start position:0% +see later in this class in the context + + + align:start position:0% +see later in this class in the context +of the central limit theorem + + align:start position:0% +of the central limit theorem + + + align:start position:0% +of the central limit theorem +they are also prevalent in applications + + align:start position:0% +they are also prevalent in applications + + + align:start position:0% +they are also prevalent in applications +for two reasons they have some nice + + align:start position:0% +for two reasons they have some nice + + + align:start position:0% +for two reasons they have some nice +analytical properties and they are also + + align:start position:0% +analytical properties and they are also + + + align:start position:0% +analytical properties and they are also +the most common model of random noise in + + align:start position:0% +the most common model of random noise in + + + align:start position:0% +the most common model of random noise in +general they are a good model of noise + + align:start position:0% +general they are a good model of noise + + + align:start position:0% +general they are a good model of noise +or randomness whenever that noise is due + + align:start position:0% +or randomness whenever that noise is due + + + align:start position:0% +or randomness whenever that noise is due +to the addition of many small + + align:start position:0% +to the addition of many small + + + align:start position:0% +to the addition of many small +independent noise terms and this is a + + align:start position:0% +independent noise terms and this is a + + + align:start position:0% +independent noise terms and this is a +very common situation in the real world + + align:start position:0% + + + + align:start position:0% + +we define normal random variables by + + align:start position:0% +we define normal random variables by + + + align:start position:0% +we define normal random variables by +specifying their PDFs and we start with + + align:start position:0% +specifying their PDFs and we start with + + + align:start position:0% +specifying their PDFs and we start with +the simplest case of the so called + + align:start position:0% +the simplest case of the so called + + + align:start position:0% +the simplest case of the so called +standard normal the standard normal is + + align:start position:0% +standard normal the standard normal is + + + align:start position:0% +standard normal the standard normal is +indicated with this shorthand notation + + align:start position:0% +indicated with this shorthand notation + + + align:start position:0% +indicated with this shorthand notation +and we will see shortly why this + + align:start position:0% +and we will see shortly why this + + + align:start position:0% +and we will see shortly why this +notation is being used it is defined in + + align:start position:0% +notation is being used it is defined in + + + align:start position:0% +notation is being used it is defined in +terms of a PDF this PDF is defined for + + align:start position:0% +terms of a PDF this PDF is defined for + + + align:start position:0% +terms of a PDF this PDF is defined for +all values of X X can be any real number + + align:start position:0% +all values of X X can be any real number + + + align:start position:0% +all values of X X can be any real number +so this random variable takes values can + + align:start position:0% +so this random variable takes values can + + + align:start position:0% +so this random variable takes values can +take values anywhere on the real line + + align:start position:0% +take values anywhere on the real line + + + align:start position:0% +take values anywhere on the real line +and the formula for the PDF is this one + + align:start position:0% +and the formula for the PDF is this one + + + align:start position:0% +and the formula for the PDF is this one +let us try to understand this formula so + + align:start position:0% +let us try to understand this formula so + + + align:start position:0% +let us try to understand this formula so +we have the exponential of negative x + + align:start position:0% +we have the exponential of negative x + + + align:start position:0% +we have the exponential of negative x +squared over 2 now if we are to plot the + + align:start position:0% +squared over 2 now if we are to plot the + + + align:start position:0% +squared over 2 now if we are to plot the +x squared over 2 function it has a shape + + align:start position:0% +x squared over 2 function it has a shape + + + align:start position:0% +x squared over 2 function it has a shape +of this form and it is centered at 0 but + + align:start position:0% +of this form and it is centered at 0 but + + + align:start position:0% +of this form and it is centered at 0 but +then we take the negative exponential of + + align:start position:0% +then we take the negative exponential of + + + align:start position:0% +then we take the negative exponential of +this function now when you take the + + align:start position:0% +this function now when you take the + + + align:start position:0% +this function now when you take the +negative exponential whenever this thing + + align:start position:0% +negative exponential whenever this thing + + + align:start position:0% +negative exponential whenever this thing +is big the negative exponential is going + + align:start position:0% +is big the negative exponential is going + + + align:start position:0% +is big the negative exponential is going +to be small so the negative exponential + + align:start position:0% +to be small so the negative exponential + + + align:start position:0% +to be small so the negative exponential +would be equal to 1 when X is equal to 0 + + align:start position:0% +would be equal to 1 when X is equal to 0 + + + align:start position:0% +would be equal to 1 when X is equal to 0 +but then as x increases because x + + align:start position:0% +but then as x increases because x + + + align:start position:0% +but then as x increases because x +squared also increases the negative + + align:start position:0% +squared also increases the negative + + + align:start position:0% +squared also increases the negative +exponential will fall off + + align:start position:0% +exponential will fall off + + + align:start position:0% +exponential will fall off +and so we obtain a shape of this kind + + align:start position:0% +and so we obtain a shape of this kind + + + align:start position:0% +and so we obtain a shape of this kind +and symmetrically on the other side as + + align:start position:0% +and symmetrically on the other side as + + + align:start position:0% +and symmetrically on the other side as +well and finally there is this constant + + align:start position:0% +well and finally there is this constant + + + align:start position:0% +well and finally there is this constant +where does this constant is coming from + + align:start position:0% +where does this constant is coming from + + + align:start position:0% +where does this constant is coming from +well there's a nice and not completely + + align:start position:0% +well there's a nice and not completely + + + align:start position:0% +well there's a nice and not completely +straightforward calculus exercise that + + align:start position:0% +straightforward calculus exercise that + + + align:start position:0% +straightforward calculus exercise that +tells us that the integral from minus + + align:start position:0% +tells us that the integral from minus + + + align:start position:0% +tells us that the integral from minus +infinity to plus infinity of e to the + + align:start position:0% +infinity to plus infinity of e to the + + + align:start position:0% +infinity to plus infinity of e to the +negative x squared over 2 DX is equal to + + align:start position:0% +negative x squared over 2 DX is equal to + + + align:start position:0% +negative x squared over 2 DX is equal to +the square root of 2 pi now we need a + + align:start position:0% +the square root of 2 pi now we need a + + + align:start position:0% +the square root of 2 pi now we need a +PDF to integrate to 1 and so for this to + + align:start position:0% +PDF to integrate to 1 and so for this to + + + align:start position:0% +PDF to integrate to 1 and so for this to +happen this is the constant that we need + + align:start position:0% +happen this is the constant that we need + + + align:start position:0% +happen this is the constant that we need +to put in front of this expression so + + align:start position:0% +to put in front of this expression so + + + align:start position:0% +to put in front of this expression so +that the integral becomes 1 and that + + align:start position:0% +that the integral becomes 1 and that + + + align:start position:0% +that the integral becomes 1 and that +explains the presence of this particular + + align:start position:0% +explains the presence of this particular + + + align:start position:0% +explains the presence of this particular +constant what is the mean of this random + + align:start position:0% +constant what is the mean of this random + + + align:start position:0% +constant what is the mean of this random +variable well x squared is symmetric + + align:start position:0% +variable well x squared is symmetric + + + align:start position:0% +variable well x squared is symmetric +around 0 and for this reason the PDF + + align:start position:0% +around 0 and for this reason the PDF + + + align:start position:0% +around 0 and for this reason the PDF +itself is symmetric around 0 and + + align:start position:0% +itself is symmetric around 0 and + + + align:start position:0% +itself is symmetric around 0 and +therefore by symmetry the mean has to be + + align:start position:0% +therefore by symmetry the mean has to be + + + align:start position:0% +therefore by symmetry the mean has to be +equal to 0 and that explains this entry + + align:start position:0% +equal to 0 and that explains this entry + + + align:start position:0% +equal to 0 and that explains this entry +here how about the variance well to + + align:start position:0% +here how about the variance well to + + + align:start position:0% +here how about the variance well to +calculate the variance you need to solve + + align:start position:0% +calculate the variance you need to solve + + + align:start position:0% +calculate the variance you need to solve +a calculus problem again you need to + + align:start position:0% +a calculus problem again you need to + + + align:start position:0% +a calculus problem again you need to +integrate by parts and after you carry + + align:start position:0% +integrate by parts and after you carry + + + align:start position:0% +integrate by parts and after you carry +out the calculation then you find that + + align:start position:0% +out the calculation then you find that + + + align:start position:0% +out the calculation then you find that +the variance is equal to 1 and that + + align:start position:0% +the variance is equal to 1 and that + + + align:start position:0% +the variance is equal to 1 and that +explains this entry here in the notation + + align:start position:0% +explains this entry here in the notation + + + align:start position:0% +explains this entry here in the notation +that we have been using let us now + + align:start position:0% +that we have been using let us now + + + align:start position:0% +that we have been using let us now +define general normal random variables + + align:start position:0% +define general normal random variables + + + align:start position:0% +define general normal random variables +general normal random variables are once + + align:start position:0% +general normal random variables are once + + + align:start position:0% +general normal random variables are once +more specified in terms of the + + align:start position:0% +more specified in terms of the + + + align:start position:0% +more specified in terms of the +corresponding PDF but this PDF is a + + align:start position:0% +corresponding PDF but this PDF is a + + + align:start position:0% +corresponding PDF but this PDF is a +little more complicated and in the + + align:start position:0% +little more complicated and in the + + + align:start position:0% +little more complicated and in the +involves two parameters mu and Sigma + + align:start position:0% +involves two parameters mu and Sigma + + + align:start position:0% +involves two parameters mu and Sigma +squared where Sigma is a given positive + + align:start position:0% +squared where Sigma is a given positive + + + align:start position:0% +squared where Sigma is a given positive +parameter once more it will have a bell + + align:start position:0% +parameter once more it will have a bell + + + align:start position:0% +parameter once more it will have a bell +shape but this Bell is no longer + + align:start position:0% +shape but this Bell is no longer + + + align:start position:0% +shape but this Bell is no longer +symmetric around 0 and there is some + + align:start position:0% +symmetric around 0 and there is some + + + align:start position:0% +symmetric around 0 and there is some +control over the width of it let us + + align:start position:0% +control over the width of it let us + + + align:start position:0% +control over the width of it let us +understand + + align:start position:0% +understand + + + align:start position:0% +understand +the form of this PDF by focusing first + + align:start position:0% +the form of this PDF by focusing first + + + align:start position:0% +the form of this PDF by focusing first +on the exponent exactly as we did for + + align:start position:0% +on the exponent exactly as we did for + + + align:start position:0% +on the exponent exactly as we did for +the standard normal case the exponent is + + align:start position:0% +the standard normal case the exponent is + + + align:start position:0% +the standard normal case the exponent is +a quadratic and that quadratic is + + align:start position:0% +a quadratic and that quadratic is + + + align:start position:0% +a quadratic and that quadratic is +centered at X equal to MU so it vanishes + + align:start position:0% +centered at X equal to MU so it vanishes + + + align:start position:0% +centered at X equal to MU so it vanishes +when X is equal to MU and becomes + + align:start position:0% +when X is equal to MU and becomes + + + align:start position:0% +when X is equal to MU and becomes +positive L square then we take the + + align:start position:0% +positive L square then we take the + + + align:start position:0% +positive L square then we take the +negative exponential of this quadratic + + align:start position:0% +negative exponential of this quadratic + + + align:start position:0% +negative exponential of this quadratic +and we obtain a function which is + + align:start position:0% +and we obtain a function which is + + + align:start position:0% +and we obtain a function which is +largest at X equal to MU and falls off + + align:start position:0% +largest at X equal to MU and falls off + + + align:start position:0% +largest at X equal to MU and falls off +as we go further away from MU what is + + align:start position:0% +as we go further away from MU what is + + + align:start position:0% +as we go further away from MU what is +the mean of this random variable since + + align:start position:0% +the mean of this random variable since + + + align:start position:0% +the mean of this random variable since +this term is symmetric around mu the PDF + + align:start position:0% +this term is symmetric around mu the PDF + + + align:start position:0% +this term is symmetric around mu the PDF +is also symmetric around mu and + + align:start position:0% +is also symmetric around mu and + + + align:start position:0% +is also symmetric around mu and +therefore the mean is also equal to MU + + align:start position:0% +therefore the mean is also equal to MU + + + align:start position:0% +therefore the mean is also equal to MU +how about the variance it turns out and + + align:start position:0% +how about the variance it turns out and + + + align:start position:0% +how about the variance it turns out and +this is a calculus exercise that we will + + align:start position:0% +this is a calculus exercise that we will + + + align:start position:0% +this is a calculus exercise that we will +omit that the variance of this PDF is + + align:start position:0% +omit that the variance of this PDF is + + + align:start position:0% +omit that the variance of this PDF is +equal to Sigma squared and this explains + + align:start position:0% +equal to Sigma squared and this explains + + + align:start position:0% +equal to Sigma squared and this explains +this notation here we're dealing with a + + align:start position:0% +this notation here we're dealing with a + + + align:start position:0% +this notation here we're dealing with a +normal that has a mean of mu and the + + align:start position:0% +normal that has a mean of mu and the + + + align:start position:0% +normal that has a mean of mu and the +variance of Sigma squared to get a + + align:start position:0% +variance of Sigma squared to get a + + + align:start position:0% +variance of Sigma squared to get a +little bit of understanding of the role + + align:start position:0% +little bit of understanding of the role + + + align:start position:0% +little bit of understanding of the role +of Sigma in the form of this PDF let us + + align:start position:0% +of Sigma in the form of this PDF let us + + + align:start position:0% +of Sigma in the form of this PDF let us +consider the case where Sigma is small + + align:start position:0% +consider the case where Sigma is small + + + align:start position:0% +consider the case where Sigma is small +and see how the picture is going to + + align:start position:0% +and see how the picture is going to + + + align:start position:0% +and see how the picture is going to +change when Sigma is small and we plot + + align:start position:0% +change when Sigma is small and we plot + + + align:start position:0% +change when Sigma is small and we plot +the quadratic Sigma being small means + + align:start position:0% +the quadratic Sigma being small means + + + align:start position:0% +the quadratic Sigma being small means +that this quadratic becomes larger so it + + align:start position:0% +that this quadratic becomes larger so it + + + align:start position:0% +that this quadratic becomes larger so it +rises faster so we get a narrower + + align:start position:0% +rises faster so we get a narrower + + + align:start position:0% +rises faster so we get a narrower +quadratic and in that case the negative + + align:start position:0% +quadratic and in that case the negative + + + align:start position:0% +quadratic and in that case the negative +exponential is going to fall off much + + align:start position:0% +exponential is going to fall off much + + + align:start position:0% +exponential is going to fall off much +faster so when Sigma is small the PDF + + align:start position:0% +faster so when Sigma is small the PDF + + + align:start position:0% +faster so when Sigma is small the PDF +that we get is a narrower PDF and that + + align:start position:0% +that we get is a narrower PDF and that + + + align:start position:0% +that we get is a narrower PDF and that +will reflects itself in to the property + + align:start position:0% +will reflects itself in to the property + + + align:start position:0% +will reflects itself in to the property +that the variance will also be smaller + + align:start position:0% + + + + align:start position:0% + +an important property of normal random + + align:start position:0% +an important property of normal random + + + align:start position:0% +an important property of normal random +variables is that they behave very + + align:start position:0% +variables is that they behave very + + + align:start position:0% +variables is that they behave very +nicely when you form linear functions of + + align:start position:0% +nicely when you form linear functions of + + + align:start position:0% +nicely when you form linear functions of +them and this is one of the reasons why + + align:start position:0% +them and this is one of the reasons why + + + align:start position:0% +them and this is one of the reasons why +they're analytically tractable and + + align:start position:0% +they're analytically tractable and + + + align:start position:0% +they're analytically tractable and +analytically very convenient here is + + align:start position:0% +analytically very convenient here is + + + align:start position:0% +analytically very convenient here is +what I mean let us start with a normal + + align:start position:0% +what I mean let us start with a normal + + + align:start position:0% +what I mean let us start with a normal +random variable with a given mean and + + align:start position:0% +random variable with a given mean and + + + align:start position:0% +random variable with a given mean and +variance and let us form a linear + + align:start position:0% +variance and let us form a linear + + + align:start position:0% +variance and let us form a linear +function of that random variable what is + + align:start position:0% +function of that random variable what is + + + align:start position:0% +function of that random variable what is +the mean of Y well we know what it is + + align:start position:0% +the mean of Y well we know what it is + + + align:start position:0% +the mean of Y well we know what it is +linear we have a linear function of a + + align:start position:0% +linear we have a linear function of a + + + align:start position:0% +linear we have a linear function of a +random variable the mean is going to be + + align:start position:0% +random variable the mean is going to be + + + align:start position:0% +random variable the mean is going to be +a times the expected value of x which is + + align:start position:0% +a times the expected value of x which is + + + align:start position:0% +a times the expected value of x which is +mu plus B what is the variance of Y we + + align:start position:0% +mu plus B what is the variance of Y we + + + align:start position:0% +mu plus B what is the variance of Y we +know what is the variance of a linear + + align:start position:0% +know what is the variance of a linear + + + align:start position:0% +know what is the variance of a linear +function of a random variable it is a + + align:start position:0% +function of a random variable it is a + + + align:start position:0% +function of a random variable it is a +squared times the variance of X which in + + align:start position:0% +squared times the variance of X which in + + + align:start position:0% +squared times the variance of X which in +our case is Sigma squared so there is + + align:start position:0% +our case is Sigma squared so there is + + + align:start position:0% +our case is Sigma squared so there is +nothing new so far but there is an + + align:start position:0% +nothing new so far but there is an + + + align:start position:0% +nothing new so far but there is an +additional important fact the random + + align:start position:0% +additional important fact the random + + + align:start position:0% +additional important fact the random +variable Y of course has the mean and + + align:start position:0% +variable Y of course has the mean and + + + align:start position:0% +variable Y of course has the mean and +variance that we know it should have but + + align:start position:0% +variance that we know it should have but + + + align:start position:0% +variance that we know it should have but +there is an additional fact namely that + + align:start position:0% +there is an additional fact namely that + + + align:start position:0% +there is an additional fact namely that +Y is a normal random variable so + + align:start position:0% +Y is a normal random variable so + + + align:start position:0% +Y is a normal random variable so +normality is preserved when we form + + align:start position:0% +normality is preserved when we form + + + align:start position:0% +normality is preserved when we form +linear functions there is one special + + align:start position:0% +linear functions there is one special + + + align:start position:0% +linear functions there is one special +case that we need to pay some attention + + align:start position:0% +case that we need to pay some attention + + + align:start position:0% +case that we need to pay some attention +to suppose that a is equal to 0 in this + + align:start position:0% +to suppose that a is equal to 0 in this + + + align:start position:0% +to suppose that a is equal to 0 in this +case the random variable Y is just equal + + align:start position:0% +case the random variable Y is just equal + + + align:start position:0% +case the random variable Y is just equal +to B it's a constant random variable it + + align:start position:0% +to B it's a constant random variable it + + + align:start position:0% +to B it's a constant random variable it +does not have a PDF it is a degenerate + + align:start position:0% +does not have a PDF it is a degenerate + + + align:start position:0% +does not have a PDF it is a degenerate +discrete random variable so could this + + align:start position:0% +discrete random variable so could this + + + align:start position:0% +discrete random variable so could this +fact be correct that Y is also normal + + align:start position:0% +fact be correct that Y is also normal + + + align:start position:0% +fact be correct that Y is also normal +one will will adopt this as convention + + align:start position:0% +one will will adopt this as convention + + + align:start position:0% +one will will adopt this as convention +when we have a discrete random variable + + align:start position:0% +when we have a discrete random variable + + + align:start position:0% +when we have a discrete random variable +which is constant it takes a constant + + align:start position:0% +which is constant it takes a constant + + + align:start position:0% +which is constant it takes a constant +value we can think of this as a special + + align:start position:0% +value we can think of this as a special + + + align:start position:0% +value we can think of this as a special +degenerate case of the normal with mean + + align:start position:0% +degenerate case of the normal with mean + + + align:start position:0% +degenerate case of the normal with mean +equal to B and with variance equal to 0 + + align:start position:0% +equal to B and with variance equal to 0 + + + align:start position:0% +equal to B and with variance equal to 0 +even though it is discrete not + + align:start position:0% +even though it is discrete not + + + align:start position:0% +even though it is discrete not +continuous we will still think of it as + + align:start position:0% +continuous we will still think of it as + + + align:start position:0% +continuous we will still think of it as +a degenerate type of a normal random + + align:start position:0% +a degenerate type of a normal random + + + align:start position:0% +a degenerate type of a normal random +variable and by adopting this convention + + align:start position:0% +variable and by adopting this convention + + + align:start position:0% +variable and by adopting this convention +then + + align:start position:0% +then + + + align:start position:0% +then +we'll always be true that a linear + + align:start position:0% +we'll always be true that a linear + + + align:start position:0% +we'll always be true that a linear +function of a normal random variable is + + align:start position:0% +function of a normal random variable is + + + align:start position:0% +function of a normal random variable is +normal even if a is equal to zero now + + align:start position:0% +normal even if a is equal to zero now + + + align:start position:0% +normal even if a is equal to zero now +that we have the definition and some + + align:start position:0% +that we have the definition and some + + + align:start position:0% +that we have the definition and some +properties of normal random variables + + align:start position:0% +properties of normal random variables + + + align:start position:0% +properties of normal random variables +the next question is whether we can + + align:start position:0% +the next question is whether we can + + + align:start position:0% +the next question is whether we can +calculate probabilities associated with + + align:start position:0% +calculate probabilities associated with + + + align:start position:0% +calculate probabilities associated with +normal random variables this will be the + + align:start position:0% +normal random variables this will be the + + + align:start position:0% +normal random variables this will be the +subject of the next segment \ No newline at end of file diff --git a/6wbWEDAg3B0.txt b/6wbWEDAg3B0.txt new file mode 100644 index 0000000000000000000000000000000000000000..94b109f3c3149a13a60a661800e7e931af3d438c --- /dev/null +++ b/6wbWEDAg3B0.txt @@ -0,0 +1,6186 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT OpenCourseWare continue to + + align:start position:0% +will help MIT OpenCourseWare continue to + + + align:start position:0% +will help MIT OpenCourseWare continue to +offer high quality educational resources + + align:start position:0% +offer high quality educational resources + + + align:start position:0% +offer high quality educational resources +for free + + align:start position:0% +for free + + + align:start position:0% +for free +to make a donation or to view additional + + align:start position:0% +to make a donation or to view additional + + + align:start position:0% +to make a donation or to view additional +materials from hundreds of MIT courses + + align:start position:0% +materials from hundreds of MIT courses + + + align:start position:0% +materials from hundreds of MIT courses +visit MIT opencourseware at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +now this the main topic of this lecture + + align:start position:0% +now this the main topic of this lecture + + + align:start position:0% +now this the main topic of this lecture +is so important and so beautiful that I + + align:start position:0% +is so important and so beautiful that I + + + align:start position:0% +is so important and so beautiful that I +don't want to spend any time reviewing + + align:start position:0% +don't want to spend any time reviewing + + + align:start position:0% +don't want to spend any time reviewing +what I did last time at the beginning + + align:start position:0% +what I did last time at the beginning + + + align:start position:0% +what I did last time at the beginning +when we talked about the rigid rotor I + + align:start position:0% +when we talked about the rigid rotor I + + + align:start position:0% +when we talked about the rigid rotor I +said that this is a not just a simple + + align:start position:0% +said that this is a not just a simple + + + align:start position:0% +said that this is a not just a simple +exactly solve problem but it tells you + + align:start position:0% +exactly solve problem but it tells you + + + align:start position:0% +exactly solve problem but it tells you +about the angular part of every central + + align:start position:0% +about the angular part of every central + + + align:start position:0% +about the angular part of every central +force problem and it's even more than + + align:start position:0% +force problem and it's even more than + + + align:start position:0% +force problem and it's even more than +that it enables you to do a certain kind + + align:start position:0% +that it enables you to do a certain kind + + + align:start position:0% +that it enables you to do a certain kind +of algebra with operators which enables + + align:start position:0% +of algebra with operators which enables + + + align:start position:0% +of algebra with operators which enables +you to minimize the effort of + + align:start position:0% +you to minimize the effort of + + + align:start position:0% +you to minimize the effort of +calculating matrix elements and + + align:start position:0% +calculating matrix elements and + + + align:start position:0% +calculating matrix elements and +predicting selection rules simply by the + + align:start position:0% +predicting selection rules simply by the + + + align:start position:0% +predicting selection rules simply by the +basis of commutation rules of the + + align:start position:0% +basis of commutation rules of the + + + align:start position:0% +basis of commutation rules of the +operators without ever looking at wave + + align:start position:0% +operators without ever looking at wave + + + align:start position:0% +operators without ever looking at wave +functions without ever looking at + + align:start position:0% +functions without ever looking at + + + align:start position:0% +functions without ever looking at +differential operators this is a really + + align:start position:0% +differential operators this is a really + + + align:start position:0% +differential operators this is a really +beautiful thing about angular momentum + + align:start position:0% +beautiful thing about angular momentum + + + align:start position:0% +beautiful thing about angular momentum +that if we define the angular momentum + + align:start position:0% +that if we define the angular momentum + + + align:start position:0% +that if we define the angular momentum +in this abstract way and I'll describe + + align:start position:0% +in this abstract way and I'll describe + + + align:start position:0% +in this abstract way and I'll describe +what I mean by this epsilon ijk if we + + align:start position:0% +what I mean by this epsilon ijk if we + + + align:start position:0% +what I mean by this epsilon ijk if we +say we have an operator which obeys this + + align:start position:0% +say we have an operator which obeys this + + + align:start position:0% +say we have an operator which obeys this +sort of this commutation rule we will + + align:start position:0% +sort of this commutation rule we will + + + align:start position:0% +sort of this commutation rule we will +call it an angular momentum and we go + + align:start position:0% +call it an angular momentum and we go + + + align:start position:0% +call it an angular momentum and we go +through some arguments and we discover + + align:start position:0% +through some arguments and we discover + + + align:start position:0% +through some arguments and we discover +the properties of all angular momentum + + align:start position:0% +the properties of all angular momentum + + + align:start position:0% +the properties of all angular momentum +in quotes now we define an angular + + align:start position:0% +in quotes now we define an angular + + + align:start position:0% +in quotes now we define an angular +momentum classically it's R cross P it's + + align:start position:0% +momentum classically it's R cross P it's + + + align:start position:0% +momentum classically it's R cross P it's +a vector and now there are things where + + align:start position:0% +a vector and now there are things where + + + align:start position:0% +a vector and now there are things where +operators where there is no R or P what + + align:start position:0% +operators where there is no R or P what + + + align:start position:0% +operators where there is no R or P what +we would like to describe them as + + align:start position:0% +we would like to describe them as + + + align:start position:0% +we would like to describe them as +angular momenta one of them is electron + + align:start position:0% +angular momenta one of them is electron + + + align:start position:0% +angular momenta one of them is electron +spin something that we sort of take for + + align:start position:0% +spin something that we sort of take for + + + align:start position:0% +spin something that we sort of take for +granted and nuclear spin all of magnetic + + align:start position:0% +granted and nuclear spin all of magnetic + + + align:start position:0% +granted and nuclear spin all of magnetic +NMR + + align:start position:0% +NMR + + + align:start position:0% +NMR +is based on these things we call angular + + align:start position:0% +is based on these things we call angular + + + align:start position:0% +is based on these things we call angular +momenta because they obey some rules and + + align:start position:0% + + + + align:start position:0% + +so what I'm going to do is show the + + align:start position:0% +so what I'm going to do is show the + + + align:start position:0% +so what I'm going to do is show the +rules and show where all of this comes + + align:start position:0% +rules and show where all of this comes + + + align:start position:0% +rules and show where all of this comes +from and that this is an abstract and so + + align:start position:0% +from and that this is an abstract and so + + + align:start position:0% +from and that this is an abstract and so +kind of dry derivation but it has + + align:start position:0% +kind of dry derivation but it has + + + align:start position:0% +kind of dry derivation but it has +astonishing consequences and basically + + align:start position:0% +astonishing consequences and basically + + + align:start position:0% +astonishing consequences and basically +it means that if you've got angular + + align:start position:0% +it means that if you've got angular + + + align:start position:0% +it means that if you've got angular +momenta if you know these rules you're + + align:start position:0% +momenta if you know these rules you're + + + align:start position:0% +momenta if you know these rules you're +never going to evaluate another matrix + + align:start position:0% +never going to evaluate another matrix + + + align:start position:0% +never going to evaluate another matrix +of them in your life now it has another + + align:start position:0% +of them in your life now it has another + + + align:start position:0% +of them in your life now it has another +level of complexity sometimes you have + + align:start position:0% +level of complexity sometimes you have + + + align:start position:0% +level of complexity sometimes you have +operators that are made out of + + align:start position:0% +operators that are made out of + + + align:start position:0% +operators that are made out of +combinations of angular momenta and you + + align:start position:0% +combinations of angular momenta and you + + + align:start position:0% +combinations of angular momenta and you +can use these sorts of arguments to + + align:start position:0% +can use these sorts of arguments to + + + align:start position:0% +can use these sorts of arguments to +derive the matrix elements of them + + align:start position:0% +derive the matrix elements of them + + + align:start position:0% +derive the matrix elements of them +that's called the Vigna record theorem + + align:start position:0% +that's called the Vigna record theorem + + + align:start position:0% +that's called the Vigna record theorem +and it means that the angular part of + + align:start position:0% +and it means that the angular part of + + + align:start position:0% +and it means that the angular part of +every operator is in your hands without + + align:start position:0% +every operator is in your hands without + + + align:start position:0% +every operator is in your hands without +ever looking at a wave function or a + + align:start position:0% +ever looking at a wave function or a + + + align:start position:0% +ever looking at a wave function or a +differential operator now we're not + + align:start position:0% +differential operator now we're not + + + align:start position:0% +differential operator now we're not +going to go there but this is a very + + align:start position:0% +going to go there but this is a very + + + align:start position:0% +going to go there but this is a very +important area of quantum mechanics and + + align:start position:0% +important area of quantum mechanics and + + + align:start position:0% +important area of quantum mechanics and +you've heard of three J symbols and + + align:start position:0% +you've heard of three J symbols and + + + align:start position:0% +you've heard of three J symbols and +raqqa coefficients and maybe you haven't + + align:start position:0% +raqqa coefficients and maybe you haven't + + + align:start position:0% +raqqa coefficients and maybe you haven't +but there is just a rich literature of + + align:start position:0% +but there is just a rich literature of + + + align:start position:0% +but there is just a rich literature of +this sort of stuff ok so today I'm going + + align:start position:0% +this sort of stuff ok so today I'm going + + + align:start position:0% +this sort of stuff ok so today I'm going +to talk briefly about rotational spectra + + align:start position:0% +to talk briefly about rotational spectra + + + align:start position:0% +to talk briefly about rotational spectra +because I'm a spectroscopy and from + + align:start position:0% +because I'm a spectroscopy and from + + + align:start position:0% +because I'm a spectroscopy and from +rotational spectra we learn about + + align:start position:0% +rotational spectra we learn about + + + align:start position:0% +rotational spectra we learn about +molecular geometry now it's really + + align:start position:0% +molecular geometry now it's really + + + align:start position:0% +molecular geometry now it's really +strange + + align:start position:0% +strange + + + align:start position:0% +strange +because why don't we just look at a + + align:start position:0% +because why don't we just look at a + + + align:start position:0% +because why don't we just look at a +molecule and measure it well we can't + + align:start position:0% +molecule and measure it well we can't + + + align:start position:0% +molecule and measure it well we can't +because it's smaller than the wavelength + + align:start position:0% +because it's smaller than the wavelength + + + align:start position:0% +because it's smaller than the wavelength +of light that we use we would use to + + align:start position:0% +of light that we use we would use to + + + align:start position:0% +of light that we use we would use to +illuminate our ruler and so we get the + + align:start position:0% +illuminate our ruler and so we get the + + + align:start position:0% +illuminate our ruler and so we get the +structure of a molecule the geometric + + align:start position:0% +structure of a molecule the geometric + + + align:start position:0% +structure of a molecule the geometric +structure at least part of it from the + + align:start position:0% +structure at least part of it from the + + + align:start position:0% +structure at least part of it from the +rotational spectrum now I'm only going + + align:start position:0% +rotational spectrum now I'm only going + + + align:start position:0% +rotational spectrum now I'm only going +to talk about the rotational spectrum of + + align:start position:0% +to talk about the rotational spectrum of + + + align:start position:0% +to talk about the rotational spectrum of +a diatomic molecule you don't want me to + + align:start position:0% +a diatomic molecule you don't want me to + + + align:start position:0% +a diatomic molecule you don't want me to +go further because polyatomic molecules + + align:start position:0% +go further because polyatomic molecules + + + align:start position:0% +go further because polyatomic molecules +have extra complexity which you could + + align:start position:0% +have extra complexity which you could + + + align:start position:0% +have extra complexity which you could +understand but I don't want to go there + + align:start position:0% +understand but I don't want to go there + + + align:start position:0% +understand but I don't want to go there +because we got a lot of other stuff to + + align:start position:0% +because we got a lot of other stuff to + + + align:start position:0% +because we got a lot of other stuff to +do I also had promised to talk about + + align:start position:0% +do I also had promised to talk about + + + align:start position:0% +do I also had promised to talk about +visualization of wave functions and I'll + + align:start position:0% +visualization of wave functions and I'll + + + align:start position:0% +visualization of wave functions and I'll +leave that to your previous experience + + align:start position:0% +leave that to your previous experience + + + align:start position:0% +leave that to your previous experience +but I do want to comment we often take a + + align:start position:0% +but I do want to comment we often take a + + + align:start position:0% +but I do want to comment we often take a +sum of wave functions for positive and + + align:start position:0% +sum of wave functions for positive and + + + align:start position:0% +sum of wave functions for positive and +negative projection quantum numbers to + + align:start position:0% +negative projection quantum numbers to + + + align:start position:0% +negative projection quantum numbers to +make them real or pure imaginary when we + + align:start position:0% +make them real or pure imaginary when we + + + align:start position:0% +make them real or pure imaginary when we +do that there are still I can functions + + align:start position:0% +do that there are still I can functions + + + align:start position:0% +do that there are still I can functions +of the angular momentum squared but + + align:start position:0% +of the angular momentum squared but + + + align:start position:0% +of the angular momentum squared but +they're not eigenfunctions of a + + align:start position:0% +they're not eigenfunctions of a + + + align:start position:0% +they're not eigenfunctions of a +projection and you could in fact maybe + + align:start position:0% +projection and you could in fact maybe + + + align:start position:0% +projection and you could in fact maybe +you will on Thursday + + align:start position:0% +you will on Thursday + + + align:start position:0% +you will on Thursday +actually evaluate L Z times a + + align:start position:0% +actually evaluate L Z times a + + + align:start position:0% +actually evaluate L Z times a +symmetrized function so by symmetry + + align:start position:0% +symmetrized function so by symmetry + + + align:start position:0% +symmetrized function so by symmetry +seing them you'll get to see the nodal + + align:start position:0% +seing them you'll get to see the nodal + + + align:start position:0% +seing them you'll get to see the nodal +structure which is nice but you lose the + + align:start position:0% +structure which is nice but you lose the + + + align:start position:0% +structure which is nice but you lose the +fact that you have Augen functions of a + + align:start position:0% +fact that you have Augen functions of a + + + align:start position:0% +fact that you have Augen functions of a +projection angular momentum and that's + + align:start position:0% +projection angular momentum and that's + + + align:start position:0% +projection angular momentum and that's +that's kind of sad okay so spectra and + + align:start position:0% +that's kind of sad okay so spectra and + + + align:start position:0% +that's kind of sad okay so spectra and +so we have a a diatomic molecule ma MB + + align:start position:0% +so we have a a diatomic molecule ma MB + + + align:start position:0% +so we have a a diatomic molecule ma MB +we have a center of mass and and so + + align:start position:0% +we have a center of mass and and so + + + align:start position:0% +we have a center of mass and and so +we're going to be interested in the + + align:start position:0% +we're going to be interested in the + + + align:start position:0% +we're going to be interested in the +energy levels for rotation of the + + align:start position:0% +energy levels for rotation of the + + + align:start position:0% +energy levels for rotation of the +molecule around an axis which is + + align:start position:0% +molecule around an axis which is + + + align:start position:0% +molecule around an axis which is +perpendicular to the bond axis and when + + align:start position:0% +perpendicular to the bond axis and when + + + align:start position:0% +perpendicular to the bond axis and when +we do that we discovered that the energy + + align:start position:0% +we do that we discovered that the energy + + + align:start position:0% +we do that we discovered that the energy +levels are given by the rotational + + align:start position:0% +levels are given by the rotational + + + align:start position:0% +levels are given by the rotational +Hamiltonian and for rotation it's free + + align:start position:0% +Hamiltonian and for rotation it's free + + + align:start position:0% +Hamiltonian and for rotation it's free +rotation so there's no potential and the + + align:start position:0% +rotation so there's no potential and the + + + align:start position:0% +rotation so there's no potential and the +operator is l squared or Jase + + align:start position:0% +operator is l squared or Jase + + + align:start position:0% +operator is l squared or Jase +that's another thing you know you + + align:start position:0% +that's another thing you know you + + + align:start position:0% +that's another thing you know you +already have experienced my use of L and + + align:start position:0% +already have experienced my use of L and + + + align:start position:0% +already have experienced my use of L and +J and maybe some other things they're + + align:start position:0% +J and maybe some other things they're + + + align:start position:0% +J and maybe some other things they're +all angular momenta they're all the same + + align:start position:0% +all angular momenta they're all the same + + + align:start position:0% +all angular momenta they're all the same +sort of thing although L is usually + + align:start position:0% +sort of thing although L is usually + + + align:start position:0% +sort of thing although L is usually +referring to electronic coordinates and + + align:start position:0% +referring to electronic coordinates and + + + align:start position:0% +referring to electronic coordinates and +J is usually referring to nuclear + + align:start position:0% +J is usually referring to nuclear + + + align:start position:0% +J is usually referring to nuclear +coordinates + + align:start position:0% +coordinates + + + align:start position:0% +coordinates +Big D no but you get a sense that we're + + align:start position:0% +Big D no but you get a sense that we're + + + align:start position:0% +Big D no but you get a sense that we're +talking about a very rich rich idea + + align:start position:0% +talking about a very rich rich idea + + + align:start position:0% +talking about a very rich rich idea +where it doesn't matter what you name + + align:start position:0% +where it doesn't matter what you name + + + align:start position:0% +where it doesn't matter what you name +the things we they follow the same rules + + align:start position:0% +the things we they follow the same rules + + + align:start position:0% +the things we they follow the same rules +okay so we have a single term in the + + align:start position:0% +okay so we have a single term in the + + + align:start position:0% +okay so we have a single term in the +Hamiltonian you are zero squared or this + + align:start position:0% +Hamiltonian you are zero squared or this + + + align:start position:0% +Hamiltonian you are zero squared or this +might be the equilibrium instead of the + + align:start position:0% +might be the equilibrium instead of the + + + align:start position:0% +might be the equilibrium instead of the +the just affixed in your nuclear + + align:start position:0% +the just affixed in your nuclear + + + align:start position:0% +the just affixed in your nuclear +distance but we're talking about a rigid + + align:start position:0% +distance but we're talking about a rigid + + + align:start position:0% +distance but we're talking about a rigid +rotor so our zero is the inter nuclear + + align:start position:0% +rotor so our zero is the inter nuclear + + + align:start position:0% +rotor so our zero is the inter nuclear +distance and now I want to be able to + + align:start position:0% +distance and now I want to be able to + + + align:start position:0% +distance and now I want to be able to +the right okay so I want to have this + + align:start position:0% +the right okay so I want to have this + + + align:start position:0% +the right okay so I want to have this +quantity I want to have this quantity in + + align:start position:0% +quantity I want to have this quantity in + + + align:start position:0% +quantity I want to have this quantity in +reciprocal centimeter units because + + align:start position:0% +reciprocal centimeter units because + + + align:start position:0% +reciprocal centimeter units because +that's what all spectroscopy is do or + + align:start position:0% +that's what all spectroscopy is do or + + + align:start position:0% +that's what all spectroscopy is do or +sometimes they use megahertz in that + + align:start position:0% +sometimes they use megahertz in that + + + align:start position:0% +sometimes they use megahertz in that +case the the speed of light is gone and + + align:start position:0% +case the the speed of light is gone and + + + align:start position:0% +case the the speed of light is gone and +when I when I evaluate the effect of + + align:start position:0% +when I when I evaluate the effect of + + + align:start position:0% +when I when I evaluate the effect of +this operator on a wave function we get + + align:start position:0% +this operator on a wave function we get + + + align:start position:0% +this operator on a wave function we get +an H bar squared which cancels that we + + align:start position:0% +an H bar squared which cancels that we + + + align:start position:0% +an H bar squared which cancels that we +would like to have an energy level + + align:start position:0% +would like to have an energy level + + + align:start position:0% +would like to have an energy level +expression e JM is equal to HC be L so + + align:start position:0% +expression e JM is equal to HC be L so + + + align:start position:0% +expression e JM is equal to HC be L so +the units of be just accommodate the + + align:start position:0% +the units of be just accommodate the + + + align:start position:0% +the units of be just accommodate the +fact that we want it in wave numbers + + align:start position:0% +fact that we want it in wave numbers + + + align:start position:0% +fact that we want it in wave numbers +but this is energy so we need the HC and + + align:start position:0% +but this is energy so we need the HC and + + + align:start position:0% +but this is energy so we need the HC and +when the operator operates we get an H + + align:start position:0% +when the operator operates we get an H + + + align:start position:0% +when the operator operates we get an H +bar squared and that that's cancelled by + + align:start position:0% +bar squared and that that's cancelled by + + + align:start position:0% +bar squared and that that's cancelled by +this factor here and so the handy dandy + + align:start position:0% +this factor here and so the handy dandy + + + align:start position:0% +this factor here and so the handy dandy +expression for the rotational constant + + align:start position:0% +expression for the rotational constant + + + align:start position:0% +expression for the rotational constant +is sixteen point eight five six seven + + align:start position:0% +is sixteen point eight five six seven + + + align:start position:0% +is sixteen point eight five six seven +three times the reduced mass in a.m. + + align:start position:0% +three times the reduced mass in a.m. + + + align:start position:0% +three times the reduced mass in a.m. +units times the internuclear distance in + + align:start position:0% +units times the internuclear distance in + + + align:start position:0% +units times the internuclear distance in +angstrom units squared reciprocal so if + + align:start position:0% +angstrom units squared reciprocal so if + + + align:start position:0% +angstrom units squared reciprocal so if +you want to know the energy I want to + + align:start position:0% +you want to know the energy I want to + + + align:start position:0% +you want to know the energy I want to +know the rotational constant in wave + + align:start position:0% +know the rotational constant in wave + + + align:start position:0% +know the rotational constant in wave +number units this is the conversion big + + align:start position:0% +number units this is the conversion big + + + align:start position:0% +number units this is the conversion big +deal okay so the energy levels are + + align:start position:0% +deal okay so the energy levels are + + + align:start position:0% +deal okay so the energy levels are +simply well I'm gonna stick with a lemon + + align:start position:0% +simply well I'm gonna stick with a lemon + + + align:start position:0% +simply well I'm gonna stick with a lemon +even though I'm the hardwired to call it + + align:start position:0% +even though I'm the hardwired to call it + + + align:start position:0% +even though I'm the hardwired to call it +J now if I go back and forth between J + + align:start position:0% +J now if I go back and forth between J + + + align:start position:0% +J now if I go back and forth between J +and L have to forgive me because you + + align:start position:0% +and L have to forgive me because you + + + align:start position:0% +and L have to forgive me because you +know I just can't yes all right so we + + align:start position:0% +know I just can't yes all right so we + + + align:start position:0% +know I just can't yes all right so we +have the energy levels HC B times L L + + align:start position:0% +have the energy levels HC B times L L + + + align:start position:0% +have the energy levels HC B times L L +plus one now L is an integer and for the + + align:start position:0% +plus one now L is an integer and for the + + + align:start position:0% +plus one now L is an integer and for the +simple diatomic so you're going to deal + + align:start position:0% +simple diatomic so you're going to deal + + + align:start position:0% +simple diatomic so you're going to deal +with it's an injury can start at zero + + align:start position:0% +with it's an injury can start at zero + + + align:start position:0% +with it's an injury can start at zero +and so the energy levels be ll plus 1 B + + align:start position:0% +and so the energy levels be ll plus 1 B + + + align:start position:0% +and so the energy levels be ll plus 1 B +L plus 1 is 2 I want to make this look + + align:start position:0% +L plus 1 is 2 I want to make this look + + + align:start position:0% +L plus 1 is 2 I want to make this look +right + + align:start position:0% + + + + align:start position:0% + +this is 1 times 2 this is 2 times 3 and + + align:start position:0% +this is 1 times 2 this is 2 times 3 and + + + align:start position:0% +this is 1 times 2 this is 2 times 3 and +the 3 times 4 is 12 + + align:start position:0% +the 3 times 4 is 12 + + + align:start position:0% +the 3 times 4 is 12 +and the important thing is that this + + align:start position:0% +and the important thing is that this + + + align:start position:0% +and the important thing is that this +energy difference is 2p this energy + + align:start position:0% +energy difference is 2p this energy + + + align:start position:0% +energy difference is 2p this energy +differences for B this energy difference + + align:start position:0% +differences for B this energy difference + + + align:start position:0% +differences for B this energy difference +is 6p and so what happens in the + + align:start position:0% +is 6p and so what happens in the + + + align:start position:0% +is 6p and so what happens in the +spectrum + + align:start position:0% + + + + align:start position:0% + +here's energy here is 0 we have a line + + align:start position:0% +here's energy here is 0 we have a line + + + align:start position:0% +here's energy here is 0 we have a line +here it to be a line here at 4 b 6 b 8 b + + align:start position:0% +here it to be a line here at 4 b 6 b 8 b + + + align:start position:0% +here it to be a line here at 4 b 6 b 8 b +so if you were able to look at the + + align:start position:0% +so if you were able to look at the + + + align:start position:0% +so if you were able to look at the +rotational spectrum the lines in the + + align:start position:0% +rotational spectrum the lines in the + + + align:start position:0% +rotational spectrum the lines in the +spectrum would be evenly spaced the + + align:start position:0% +spectrum would be evenly spaced the + + + align:start position:0% +spectrum would be evenly spaced the +levels are not that's very important + + align:start position:0% +levels are not that's very important + + + align:start position:0% +levels are not that's very important +especially when you start doing + + align:start position:0% +especially when you start doing + + + align:start position:0% +especially when you start doing +perturbation theory because you're going + + align:start position:0% +perturbation theory because you're going + + + align:start position:0% +perturbation theory because you're going +to have energy denominators which are + + align:start position:0% +to have energy denominators which are + + + align:start position:0% +to have energy denominators which are +multiples of a common factor but they're + + align:start position:0% +multiples of a common factor but they're + + + align:start position:0% +multiples of a common factor but they're +not equal to each other okay but we have + + align:start position:0% +not equal to each other okay but we have + + + align:start position:0% +not equal to each other okay but we have +a spectrum and it looks really really + + align:start position:0% +a spectrum and it looks really really + + + align:start position:0% +a spectrum and it looks really really +trivial and textbooks don't talk about + + align:start position:0% +trivial and textbooks don't talk about + + + align:start position:0% +trivial and textbooks don't talk about +this but if you have a relatively light + + align:start position:0% +this but if you have a relatively light + + + align:start position:0% +this but if you have a relatively light +diatomic molecule and you have a + + align:start position:0% +diatomic molecule and you have a + + + align:start position:0% +diatomic molecule and you have a +laboratory which is equipped with a + + align:start position:0% +laboratory which is equipped with a + + + align:start position:0% +laboratory which is equipped with a +microwave spectrometer which is able to + + align:start position:0% +microwave spectrometer which is able to + + + align:start position:0% +microwave spectrometer which is able to +generate data that got you tenure and + + align:start position:0% +generate data that got you tenure and + + + align:start position:0% +generate data that got you tenure and +whatever it's it's probably a + + align:start position:0% +whatever it's it's probably a + + + align:start position:0% +whatever it's it's probably a +spectrometer where the tuning range of + + align:start position:0% +spectrometer where the tuning range of + + + align:start position:0% +spectrometer where the tuning range of +the microwave oscillator is about 30% + + align:start position:0% +the microwave oscillator is about 30% + + + align:start position:0% +the microwave oscillator is about 30% +that's a lot if you think about NMR the + + align:start position:0% +that's a lot if you think about NMR the + + + align:start position:0% +that's a lot if you think about NMR the +the tuning range is 30% is huge so you + + align:start position:0% +the tuning range is 30% is huge so you + + + align:start position:0% +the tuning range is 30% is huge so you +see this and you say oh yeah i could + + align:start position:0% +see this and you say oh yeah i could + + + align:start position:0% +see this and you say oh yeah i could +assign that spectrum because an obvious + + align:start position:0% +assign that spectrum because an obvious + + + align:start position:0% +assign that spectrum because an obvious +pattern but what happens in the spectrum + + align:start position:0% +pattern but what happens in the spectrum + + + align:start position:0% +pattern but what happens in the spectrum +is you get one line + + align:start position:0% + + + + align:start position:0% + +and so you say well what is you know I + + align:start position:0% +and so you say well what is you know I + + + align:start position:0% +and so you say well what is you know I +need to know the inter nuclear distance + + align:start position:0% +need to know the inter nuclear distance + + + align:start position:0% +need to know the inter nuclear distance +in this molecule to six or eight or ten + + align:start position:0% +in this molecule to six or eight or ten + + + align:start position:0% +in this molecule to six or eight or ten +digits but I get one line there's no + + align:start position:0% +digits but I get one line there's no + + + align:start position:0% +digits but I get one line there's no +pattern the textbooks are so full of + + align:start position:0% +pattern the textbooks are so full of + + + align:start position:0% +pattern the textbooks are so full of +formulas that you know they don't they + + align:start position:0% +formulas that you know they don't they + + + align:start position:0% +formulas that you know they don't they +don't indicate that in reality you've + + align:start position:0% +don't indicate that in reality you've + + + align:start position:0% +don't indicate that in reality you've +got a problem and in fact in reality + + align:start position:0% +got a problem and in fact in reality + + + align:start position:0% +got a problem and in fact in reality +you've got something that's also a gift + + align:start position:0% + + + + align:start position:0% + +so there's two things that happen + + align:start position:0% + + + + align:start position:0% + +isotopes and vibration so we have this + + align:start position:0% +isotopes and vibration so we have this + + + align:start position:0% +isotopes and vibration so we have this +one line we are very very strong very + + align:start position:0% +one line we are very very strong very + + + align:start position:0% +one line we are very very strong very +narrow you can measure the daylights out + + align:start position:0% +narrow you can measure the daylights out + + + align:start position:0% +narrow you can measure the daylights out +of it if you wanted to and then down + + align:start position:0% +of it if you wanted to and then down + + + align:start position:0% +of it if you wanted to and then down +here there's going to be well actually + + align:start position:0% +here there's going to be well actually + + + align:start position:0% +here there's going to be well actually +sometimes like in chlorine and bromine + + align:start position:0% +sometimes like in chlorine and bromine + + + align:start position:0% +sometimes like in chlorine and bromine +the there's a heavy isotope and a less + + align:start position:0% +the there's a heavy isotope and a less + + + align:start position:0% +the there's a heavy isotope and a less +and a light isotope and they have + + align:start position:0% +and a light isotope and they have + + + align:start position:0% +and a light isotope and they have +similar abundances and so you get + + align:start position:0% +similar abundances and so you get + + + align:start position:0% +similar abundances and so you get +isotope splittings and that's that's + + align:start position:0% +isotope splittings and that's that's + + + align:start position:0% +isotope splittings and that's that's +expressed in the reduced mass M a M B or + + align:start position:0% +expressed in the reduced mass M a M B or + + + align:start position:0% +expressed in the reduced mass M a M B or +M a plus MB now the isotope splittings + + align:start position:0% +M a plus MB now the isotope splittings + + + align:start position:0% +M a plus MB now the isotope splittings +can be really really small but these + + align:start position:0% +can be really really small but these + + + align:start position:0% +can be really really small but these +lines are I have a width of a partner + + align:start position:0% +lines are I have a width of a partner + + + align:start position:0% +lines are I have a width of a partner +million maybe maybe even never and so + + align:start position:0% +million maybe maybe even never and so + + + align:start position:0% +million maybe maybe even never and so +you can see isotope stuff that doesn't + + align:start position:0% +you can see isotope stuff that doesn't + + + align:start position:0% +you can see isotope stuff that doesn't +tell you anything at all that you didn't + + align:start position:0% +tell you anything at all that you didn't + + + align:start position:0% +tell you anything at all that you didn't +know except maybe that you were confused + + align:start position:0% +know except maybe that you were confused + + + align:start position:0% +know except maybe that you were confused +about what molecule it was because if + + align:start position:0% +about what molecule it was because if + + + align:start position:0% +about what molecule it was because if +you have a particular atom it's always + + align:start position:0% +you have a particular atom it's always + + + align:start position:0% +you have a particular atom it's always +born with the other with the normal + + align:start position:0% +born with the other with the normal + + + align:start position:0% +born with the other with the normal +isotope ratios except here we have a + + align:start position:0% +isotope ratios except here we have a + + + align:start position:0% +isotope ratios except here we have a +little problem where in sulfur if you + + align:start position:0% +little problem where in sulfur if you + + + align:start position:0% +little problem where in sulfur if you +look in minerals the isotope ratios are + + align:start position:0% +look in minerals the isotope ratios are + + + align:start position:0% +look in minerals the isotope ratios are +not the naturally abundant of sulfur + + align:start position:0% +not the naturally abundant of sulfur + + + align:start position:0% +not the naturally abundant of sulfur +isotope and this has to do with + + align:start position:0% +isotope and this has to do with + + + align:start position:0% +isotope and this has to do with +something really important that happened + + align:start position:0% +something really important that happened + + + align:start position:0% +something really important that happened +two and a half billion years ago right + + align:start position:0% +two and a half billion years ago right + + + align:start position:0% +two and a half billion years ago right +well oxygen happened was and and so + + align:start position:0% +well oxygen happened was and and so + + + align:start position:0% +well oxygen happened was and and so +isotope ratios are of some geological + + align:start position:0% +isotope ratios are of some geological + + + align:start position:0% +isotope ratios are of some geological +chemical significance but here you know + + align:start position:0% +chemical significance but here you know + + + align:start position:0% +chemical significance but here you know +if you know what the molecule is there + + align:start position:0% +if you know what the molecule is there + + + align:start position:0% +if you know what the molecule is there +will be isotope lines and they can be + + align:start position:0% +will be isotope lines and they can be + + + align:start position:0% +will be isotope lines and they can be +pretty strong because depending on the + + align:start position:0% +pretty strong because depending on the + + + align:start position:0% +pretty strong because depending on the +relative abundance of the different + + align:start position:0% +relative abundance of the different + + + align:start position:0% +relative abundance of the different +isotopes or they can be extremely weak + + align:start position:0% +isotopes or they can be extremely weak + + + align:start position:0% +isotopes or they can be extremely weak +but so there's their stuff there's some + + align:start position:0% +but so there's their stuff there's some + + + align:start position:0% +but so there's their stuff there's some +grass to be mowed on the base line in + + align:start position:0% +grass to be mowed on the base line in + + + align:start position:0% +grass to be mowed on the base line in +addition and this is something that + + align:start position:0% +addition and this is something that + + + align:start position:0% +addition and this is something that +really surprises people so here is V + + align:start position:0% +really surprises people so here is V + + + align:start position:0% +really surprises people so here is V +equals zero + + align:start position:0% +equals zero + + + align:start position:0% +equals zero +and way up high is V equals one + + align:start position:0% +and way up high is V equals one + + + align:start position:0% +and way up high is V equals one +typically the vibrational intervals are + + align:start position:0% +typically the vibrational intervals are + + + align:start position:0% +typically the vibrational intervals are +on the order of a thousand times bigger + + align:start position:0% +on the order of a thousand times bigger + + + align:start position:0% +on the order of a thousand times bigger +than the rotational intervals and + + align:start position:0% +than the rotational intervals and + + + align:start position:0% +than the rotational intervals and +typically the rotational constant + + align:start position:0% +typically the rotational constant + + + align:start position:0% +typically the rotational constant +decreases in steps of about a tenth of a + + align:start position:0% +decreases in steps of about a tenth of a + + + align:start position:0% +decreases in steps of about a tenth of a +percent for vibration now we do care + + align:start position:0% +percent for vibration now we do care + + + align:start position:0% +percent for vibration now we do care +about how much it decreases because that + + align:start position:0% +about how much it decreases because that + + + align:start position:0% +about how much it decreases because that +allows us to know a whole bunch of stuff + + align:start position:0% +allows us to know a whole bunch of stuff + + + align:start position:0% +allows us to know a whole bunch of stuff +about how rotation and vibration + + align:start position:0% + + + + align:start position:0% + +interact and I'm not probably going to + + align:start position:0% +interact and I'm not probably going to + + + align:start position:0% +interact and I'm not probably going to +do that the lecture on the rotation + + align:start position:0% +do that the lecture on the rotation + + + align:start position:0% +do that the lecture on the rotation +vibration interaction unless I have to + + align:start position:0% +vibration interaction unless I have to + + + align:start position:0% +vibration interaction unless I have to +give a lecture on something that I can't + + align:start position:0% +give a lecture on something that I can't + + + align:start position:0% +give a lecture on something that I can't +do I'll slip in that one okay so what + + align:start position:0% +do I'll slip in that one okay so what + + + align:start position:0% +do I'll slip in that one okay so what +happens is there is a there are + + align:start position:0% +happens is there is a there are + + + align:start position:0% +happens is there is a there are +vibrational satellites so here is V + + align:start position:0% +vibrational satellites so here is V + + + align:start position:0% +vibrational satellites so here is V +equals zero it has rotational structure + + align:start position:0% +equals zero it has rotational structure + + + align:start position:0% +equals zero it has rotational structure +and here is V equals one it has + + align:start position:0% +and here is V equals one it has + + + align:start position:0% +and here is V equals one it has +rotational structure the V equals one + + align:start position:0% +rotational structure the V equals one + + + align:start position:0% +rotational structure the V equals one +stuff is typically a hundred to a + + align:start position:0% +stuff is typically a hundred to a + + + align:start position:0% +stuff is typically a hundred to a +thousand times weaker than the V equals + + align:start position:0% +thousand times weaker than the V equals + + + align:start position:0% +thousand times weaker than the V equals +0 stuff and that's basically telling you + + align:start position:0% +0 stuff and that's basically telling you + + + align:start position:0% +0 stuff and that's basically telling you +how does the molecules change its + + align:start position:0% +how does the molecules change its + + + align:start position:0% +how does the molecules change its +average one over R squared as it + + align:start position:0% +average one over R squared as it + + + align:start position:0% +average one over R squared as it +vibrates and that's a useful thing may + + align:start position:0% +vibrates and that's a useful thing may + + + align:start position:0% +vibrates and that's a useful thing may +even be useful on Thursday + + align:start position:0% + + + + align:start position:0% + +so in addition to hyperfine there's + + align:start position:0% +so in addition to hyperfine there's + + + align:start position:0% +so in addition to hyperfine there's +other small stuff having to do with + + align:start position:0% +other small stuff having to do with + + + align:start position:0% +other small stuff having to do with +vibrations and in some experiments that + + align:start position:0% +vibrations and in some experiments that + + + align:start position:0% +vibrations and in some experiments that +I do we use UV light to break a molecule + + align:start position:0% +I do we use UV light to break a molecule + + + align:start position:0% +I do we use UV light to break a molecule +and the fragments that we make are borne + + align:start position:0% +and the fragments that we make are borne + + + align:start position:0% +and the fragments that we make are borne +vibrationally excited and so by looking + + align:start position:0% +vibrationally excited and so by looking + + + align:start position:0% +vibrationally excited and so by looking +at the the stuff near the v equals zero + + align:start position:0% +at the the stuff near the v equals zero + + + align:start position:0% +at the the stuff near the v equals zero +frequency you see a whole bunch of stuff + + align:start position:0% +frequency you see a whole bunch of stuff + + + align:start position:0% +frequency you see a whole bunch of stuff +which tells you the populations of the + + align:start position:0% +which tells you the populations of the + + + align:start position:0% +which tells you the populations of the +different vibrational levels and that's + + align:start position:0% +different vibrational levels and that's + + + align:start position:0% +different vibrational levels and that's +strange because vibration is not part of + + align:start position:0% +strange because vibration is not part of + + + align:start position:0% +strange because vibration is not part of +the rotational spectrum vibration is big + + align:start position:0% +the rotational spectrum vibration is big + + + align:start position:0% +the rotational spectrum vibration is big +but we get vibrational information from + + align:start position:0% +but we get vibrational information from + + + align:start position:0% +but we get vibrational information from +the rotational spectrum and because the + + align:start position:0% +the rotational spectrum and because the + + + align:start position:0% +the rotational spectrum and because the +rotational spectrum is at such high + + align:start position:0% +rotational spectrum is at such high + + + align:start position:0% +rotational spectrum is at such high +resolution it's trivial to resolve and + + align:start position:0% +resolution it's trivial to resolve and + + + align:start position:0% +resolution it's trivial to resolve and +to detect these weak other features so + + align:start position:0% +to detect these weak other features so + + + align:start position:0% +to detect these weak other features so +this is you know as much as I'm going to + + align:start position:0% +this is you know as much as I'm going to + + + align:start position:0% +this is you know as much as I'm going to +talk about spectroscopy it's a little + + align:start position:0% +talk about spectroscopy it's a little + + + align:start position:0% +talk about spectroscopy it's a little +bit more than I had originally planned + + align:start position:0% +bit more than I had originally planned + + + align:start position:0% +bit more than I had originally planned +and now we're going to move to this + + align:start position:0% +and now we're going to move to this + + + align:start position:0% +and now we're going to move to this +topic which is dear to my heart and it's + + align:start position:0% +topic which is dear to my heart and it's + + + align:start position:0% +topic which is dear to my heart and it's +an example of an abstract algebra that + + align:start position:0% +an example of an abstract algebra that + + + align:start position:0% +an example of an abstract algebra that +you use in quantum mechanics and there + + align:start position:0% +you use in quantum mechanics and there + + + align:start position:0% +you use in quantum mechanics and there +are people who only do this kind of + + align:start position:0% +are people who only do this kind of + + + align:start position:0% +are people who only do this kind of +thing as opposed to solving shorter + + align:start position:0% +thing as opposed to solving shorter + + + align:start position:0% +thing as opposed to solving shorter +equation or even just doing perturbation + + align:start position:0% +equation or even just doing perturbation + + + align:start position:0% +equation or even just doing perturbation +theory on on matrices okay so rest of + + align:start position:0% +theory on on matrices okay so rest of + + + align:start position:0% +theory on on matrices okay so rest of +today's lecture is going to be an + + align:start position:0% +today's lecture is going to be an + + + align:start position:0% +today's lecture is going to be an +excursion through here as much as I can + + align:start position:0% +excursion through here as much as I can + + + align:start position:0% +excursion through here as much as I can +do it's all clear in the notes but I + + align:start position:0% +do it's all clear in the notes but I + + + align:start position:0% +do it's all clear in the notes but I +think it's a little bit strange oh I + + align:start position:0% +think it's a little bit strange oh I + + + align:start position:0% +think it's a little bit strange oh I +want to say one more thing how do we + + align:start position:0% +want to say one more thing how do we + + + align:start position:0% +want to say one more thing how do we +make assignments you all took 511 1 or + + align:start position:0% +make assignments you all took 511 1 or + + + align:start position:0% +make assignments you all took 511 1 or +511 2 or or 309 1 and there are things + + align:start position:0% +511 2 or or 309 1 and there are things + + + align:start position:0% +511 2 or or 309 1 and there are things +that you learn about how big atoms are + + align:start position:0% +that you learn about how big atoms are + + + align:start position:0% +that you learn about how big atoms are +and so you can sort of estimate what the + + align:start position:0% +and so you can sort of estimate what the + + + align:start position:0% +and so you can sort of estimate what the +inter nuclear distance is and maybe 10 + + align:start position:0% +inter nuclear distance is and maybe 10 + + + align:start position:0% +inter nuclear distance is and maybe 10 +or 20 percent that's not of any chemical + + align:start position:0% +or 20 percent that's not of any chemical + + + align:start position:0% +or 20 percent that's not of any chemical +use but it's enough to assign the + + align:start position:0% +use but it's enough to assign the + + + align:start position:0% +use but it's enough to assign the +spectrum so what you do is you assign + + align:start position:0% +spectrum so what you do is you assign + + + align:start position:0% +spectrum so what you do is you assign +you say okay I guess the internuclear + + align:start position:0% +you say okay I guess the internuclear + + + align:start position:0% +you say okay I guess the internuclear +distance exists that determines what + + align:start position:0% +distance exists that determines what + + + align:start position:0% +distance exists that determines what +rotational transition you were observing + + align:start position:0% +rotational transition you were observing + + + align:start position:0% +rotational transition you were observing +and ask + + align:start position:0% +and ask + + + align:start position:0% +and ask +sequences on suppose you're observing L + + align:start position:0% +sequences on suppose you're observing L + + + align:start position:0% +sequences on suppose you're observing L +to L plus one + + align:start position:0% +to L plus one + + + align:start position:0% +to L plus one +well what about L plus 1 l plus 2 or L + + align:start position:0% +well what about L plus 1 l plus 2 or L + + + align:start position:0% +well what about L plus 1 l plus 2 or L +minus 1 to L so if you make an + + align:start position:0% +minus 1 to L so if you make an + + + align:start position:0% +minus 1 to L so if you make an +assignment you can predict where the + + align:start position:0% +assignment you can predict where the + + + align:start position:0% +assignment you can predict where the +other guys are and and that would + + align:start position:0% +other guys are and and that would + + + align:start position:0% +other guys are and and that would +require going to one of your friends who + + align:start position:0% +require going to one of your friends who + + + align:start position:0% +require going to one of your friends who +has a different spectrometer and getting + + align:start position:0% +has a different spectrometer and getting + + + align:start position:0% +has a different spectrometer and getting +him to record a spectrum for you and + + align:start position:0% +him to record a spectrum for you and + + + align:start position:0% +him to record a spectrum for you and +that's good good for human relations and + + align:start position:0% +that's good good for human relations and + + + align:start position:0% +that's good good for human relations and +that then enables you to make + + align:start position:0% +that then enables you to make + + + align:start position:0% +that then enables you to make +assignments and know the rotational + + align:start position:0% +assignments and know the rotational + + + align:start position:0% +assignments and know the rotational +constants to as many digits as you + + align:start position:0% +constants to as many digits as you + + + align:start position:0% +constants to as many digits as you +possibly could want include all the way + + align:start position:0% +possibly could want include all the way + + + align:start position:0% +possibly could want include all the way +up to ten you know it's just crazy you + + align:start position:0% +up to ten you know it's just crazy you + + + align:start position:0% +up to ten you know it's just crazy you +really don't care about inter nuclear + + align:start position:0% +really don't care about inter nuclear + + + align:start position:0% +really don't care about inter nuclear +distances beyond about a thousandth of + + align:start position:0% +distances beyond about a thousandth of + + + align:start position:0% +distances beyond about a thousandth of +an angstrom but you can have them okay + + align:start position:0% + + + + align:start position:0% + +so first of all you know we can define + + align:start position:0% +so first of all you know we can define + + + align:start position:0% +so first of all you know we can define +an angular momentum R cross P and we can + + align:start position:0% +an angular momentum R cross P and we can + + + align:start position:0% +an angular momentum R cross P and we can +write that as a vector a matrix okay now + + align:start position:0% +write that as a vector a matrix okay now + + + align:start position:0% +write that as a vector a matrix okay now +I suspect you've all seen this these are + + align:start position:0% +I suspect you've all seen this these are + + + align:start position:0% +I suspect you've all seen this these are +unit vectors along the x y&z directions + + align:start position:0% +unit vectors along the x y&z directions + + + align:start position:0% +unit vectors along the x y&z directions +and this is a vague amay tricked so I + + align:start position:0% +and this is a vague amay tricked so I + + + align:start position:0% +and this is a vague amay tricked so I +mean a vector so there are three + + align:start position:0% +mean a vector so there are three + + + align:start position:0% +mean a vector so there are three +components and we get three components + + align:start position:0% +components and we get three components + + + align:start position:0% +components and we get three components +here now you do want to make sure you + + align:start position:0% +here now you do want to make sure you + + + align:start position:0% +here now you do want to make sure you +know this notation and know how to use + + align:start position:0% +know this notation and know how to use + + + align:start position:0% +know this notation and know how to use +it okay so here is the magic equation L + + align:start position:0% + + + + align:start position:0% + +is equal to IH bar sum over K epsilon + + align:start position:0% +is equal to IH bar sum over K epsilon + + + align:start position:0% +is equal to IH bar sum over K epsilon +ijk okay well what is epsilon ijk well + + align:start position:0% +ijk okay well what is epsilon ijk well + + + align:start position:0% +ijk okay well what is epsilon ijk well +it's got many names but it's a really + + align:start position:0% +it's got many names but it's a really + + + align:start position:0% +it's got many names but it's a really +neat tool which is very wonderful in + + align:start position:0% +neat tool which is very wonderful in + + + align:start position:0% +neat tool which is very wonderful in +enabling you to to derive new equations + + align:start position:0% +enabling you to to derive new equations + + + align:start position:0% +enabling you to to derive new equations +so if I J and K correspond to XYZ in + + align:start position:0% +so if I J and K correspond to XYZ in + + + align:start position:0% +so if I J and K correspond to XYZ in +cyclic order in other words X Y Z Y + + align:start position:0% +cyclic order in other words X Y Z Y + + + align:start position:0% +cyclic order in other words X Y Z Y +the X etc then this is plus one if it's + + align:start position:0% +the X etc then this is plus one if it's + + + align:start position:0% +the X etc then this is plus one if it's +an anti cyclic order it's minus one and + + align:start position:0% +an anti cyclic order it's minus one and + + + align:start position:0% +an anti cyclic order it's minus one and +if any index is repeated it's zero so it + + align:start position:0% +if any index is repeated it's zero so it + + + align:start position:0% +if any index is repeated it's zero so it +packs a real punch but it enables you to + + align:start position:0% +packs a real punch but it enables you to + + + align:start position:0% +packs a real punch but it enables you to +do fantastic things + + align:start position:0% +do fantastic things + + + align:start position:0% +do fantastic things +so if we have LX ly it's equal to IH bar + + align:start position:0% +so if we have LX ly it's equal to IH bar + + + align:start position:0% +so if we have LX ly it's equal to IH bar +plus 1 times LZ ok and the point of this + + align:start position:0% +plus 1 times LZ ok and the point of this + + + align:start position:0% +plus 1 times LZ ok and the point of this +lecture is with this you can derive all + + align:start position:0% +lecture is with this you can derive all + + + align:start position:0% +lecture is with this you can derive all +of the matrix elements of an angular + + align:start position:0% +of the matrix elements of an angular + + + align:start position:0% +of the matrix elements of an angular +momentum l squared LC L plus minus and + + align:start position:0% +momentum l squared LC L plus minus and + + + align:start position:0% +momentum l squared LC L plus minus and +anything else but these are the + + align:start position:0% +anything else but these are the + + + align:start position:0% +anything else but these are the +important ones and this is what we want + + align:start position:0% +important ones and this is what we want + + + align:start position:0% +important ones and this is what we want +to derive from our excursion in matrix + + align:start position:0% +to derive from our excursion in matrix + + + align:start position:0% +to derive from our excursion in matrix +element land ok so the first thing we do + + align:start position:0% +element land ok so the first thing we do + + + align:start position:0% +element land ok so the first thing we do +is we extract some fundamental equations + + align:start position:0% +is we extract some fundamental equations + + + align:start position:0% +is we extract some fundamental equations +from this commutator so the first + + align:start position:0% +from this commutator so the first + + + align:start position:0% +from this commutator so the first +equation is that l squared L Z is equal + + align:start position:0% +equation is that l squared L Z is equal + + + align:start position:0% +equation is that l squared L Z is equal +to L x squared LC plus L Y squared LC + + align:start position:0% +to L x squared LC plus L Y squared LC + + + align:start position:0% +to L x squared LC plus L Y squared LC +plus L Z squared LZ + + align:start position:0% + + + + align:start position:0% + +well we see and we know this one is zero + + align:start position:0% +well we see and we know this one is zero + + + align:start position:0% +well we see and we know this one is zero +right + + align:start position:0% +right + + + align:start position:0% +right +ok this one there you have to do a + + align:start position:0% +ok this one there you have to do a + + + align:start position:0% +ok this one there you have to do a +little practice but you can write this + + align:start position:0% +little practice but you can write this + + + align:start position:0% +little practice but you can write this +angular this out of this commutation + + align:start position:0% +angular this out of this commutation + + + align:start position:0% +angular this out of this commutation +rule as LX x LX gamma L Z + LX gamma l z + + align:start position:0% +rule as LX x LX gamma L Z + LX gamma l z + + + align:start position:0% +rule as LX x LX gamma L Z + LX gamma l z +LX so if you have a square you take take + + align:start position:0% +LX so if you have a square you take take + + + align:start position:0% +LX so if you have a square you take take +it out front side and the back side and + + align:start position:0% +it out front side and the back side and + + + align:start position:0% +it out front side and the back side and +now we know with this + + align:start position:0% +now we know with this + + + align:start position:0% +now we know with this +this is minus IH bar know why and this + + align:start position:0% +this is minus IH bar know why and this + + + align:start position:0% +this is minus IH bar know why and this +is minus H bar ly and we do this one and + + align:start position:0% +is minus H bar ly and we do this one and + + + align:start position:0% +is minus H bar ly and we do this one and +we discover we have the same thing + + align:start position:0% +we discover we have the same thing + + + align:start position:0% +we discover we have the same thing +except with the opposite sign and so + + align:start position:0% +except with the opposite sign and so + + + align:start position:0% +except with the opposite sign and so +what we end up getting is that this is + + align:start position:0% +what we end up getting is that this is + + + align:start position:0% +what we end up getting is that this is +zero now I skip some steps I said them + + align:start position:0% +zero now I skip some steps I said them + + + align:start position:0% +zero now I skip some steps I said them +but I want you to just go through that + + align:start position:0% +but I want you to just go through that + + + align:start position:0% +but I want you to just go through that +and see okay so you know you know what + + align:start position:0% +and see okay so you know you know what + + + align:start position:0% +and see okay so you know you know what +this is it's gonna be ly and it's going + + align:start position:0% +this is it's gonna be ly and it's going + + + align:start position:0% +this is it's gonna be ly and it's going +to be minus ly x IH bar and you get the + + align:start position:0% +to be minus ly x IH bar and you get the + + + align:start position:0% +to be minus ly x IH bar and you get the +same thing here but then you have a LX + + align:start position:0% +same thing here but then you have a LX + + + align:start position:0% +same thing here but then you have a LX +ly and you have an LX ly oh yeah right + + align:start position:0% + + + + align:start position:0% + +and when you do this do the same trick + + align:start position:0% +and when you do this do the same trick + + + align:start position:0% +and when you do this do the same trick +with this you're gonna get an L Y and an + + align:start position:0% +with this you're gonna get an L Y and an + + + align:start position:0% +with this you're gonna get an L Y and an +L X again and they'll be the opposite + + align:start position:0% +L X again and they'll be the opposite + + + align:start position:0% +L X again and they'll be the opposite +side okay so this one is really + + align:start position:0% +side okay so this one is really + + + align:start position:0% +side okay so this one is really +important because what it says is that + + align:start position:0% + + + + align:start position:0% + +you can you can take any projection + + align:start position:0% +you can you can take any projection + + + align:start position:0% +you can you can take any projection +quantum number and it will commute with + + align:start position:0% +quantum number and it will commute with + + + align:start position:0% +quantum number and it will commute with +the magnitude squared the same argument + + align:start position:0% +the magnitude squared the same argument + + + align:start position:0% +the magnitude squared the same argument +works for ly you know LZ and LX so we + + align:start position:0% +works for ly you know LZ and LX so we + + + align:start position:0% +works for ly you know LZ and LX so we +have one really powerful commutator + + align:start position:0% +have one really powerful commutator + + + align:start position:0% +have one really powerful commutator +which is that l squared Li equals zero + + align:start position:0% +which is that l squared Li equals zero + + + align:start position:0% +which is that l squared Li equals zero +for x y and z which means since we like + + align:start position:0% +for x y and z which means since we like + + + align:start position:0% +for x y and z which means since we like +l squared and LZ we couldn't like LX + + align:start position:0% +l squared and LZ we couldn't like LX + + + align:start position:0% +l squared and LZ we couldn't like LX +instead of LZ but we tend to favor these + + align:start position:0% +instead of LZ but we tend to favor these + + + align:start position:0% +instead of LZ but we tend to favor these +that l squared and I'll see our + + align:start position:0% +that l squared and I'll see our + + + align:start position:0% +that l squared and I'll see our +operators that can have a common set of + + align:start position:0% +operators that can have a common set of + + + align:start position:0% +operators that can have a common set of +eigenfunctions if we have two operators + + align:start position:0% +eigenfunctions if we have two operators + + + align:start position:0% +eigenfunctions if we have two operators +that commute the eigenfunctions of one + + align:start position:0% +that commute the eigenfunctions of one + + + align:start position:0% +that commute the eigenfunctions of one +can be the eigenfunction of the other + + align:start position:0% +can be the eigenfunction of the other + + + align:start position:0% +can be the eigenfunction of the other +very convenient + + align:start position:0% + + + + align:start position:0% + +okay then there's another operator that + + align:start position:0% +okay then there's another operator that + + + align:start position:0% +okay then there's another operator that +we can derive and that is let's define + + align:start position:0% +we can derive and that is let's define + + + align:start position:0% +we can derive and that is let's define +this thing a step up or step down or or + + align:start position:0% +this thing a step up or step down or or + + + align:start position:0% +this thing a step up or step down or or +a raising or lowering operator we don't + + align:start position:0% +a raising or lowering operator we don't + + + align:start position:0% +a raising or lowering operator we don't +know that yet LX plus or minus ily so we + + align:start position:0% +know that yet LX plus or minus ily so we + + + align:start position:0% +know that yet LX plus or minus ily so we +we might want to know the commutation + + align:start position:0% +we might want to know the commutation + + + align:start position:0% +we might want to know the commutation +rule of LZ with L plus minus okay we + + align:start position:0% +rule of LZ with L plus minus okay we + + + align:start position:0% +rule of LZ with L plus minus okay we +know how to write this out because we + + align:start position:0% +know how to write this out because we + + + align:start position:0% +know how to write this out because we +have LZ with LX and we know that's going + + align:start position:0% +have LZ with LX and we know that's going + + + align:start position:0% +have LZ with LX and we know that's going +to be a minus IH bar ly and we have LZ + + align:start position:0% +to be a minus IH bar ly and we have LZ + + + align:start position:0% +to be a minus IH bar ly and we have LZ +with ily and that's going to be a minus + + align:start position:0% +with ily and that's going to be a minus + + + align:start position:0% +with ily and that's going to be a minus +LX anyway I'm going to just write down + + align:start position:0% +LX anyway I'm going to just write down + + + align:start position:0% +LX anyway I'm going to just write down +the final result that this is equal to + + align:start position:0% +the final result that this is equal to + + + align:start position:0% +the final result that this is equal to +plus or minus h-bar times L plus minus + + align:start position:0% + + + + align:start position:0% + +the algebra of this operator enables you + + align:start position:0% +the algebra of this operator enables you + + + align:start position:0% +the algebra of this operator enables you +to slice through any derivation at the + + align:start position:0% +to slice through any derivation at the + + + align:start position:0% +to slice through any derivation at the +speed as fast as you can right once + + align:start position:0% +speed as fast as you can right once + + + align:start position:0% +speed as fast as you can right once +you've loaded this into your head yes + + align:start position:0% + + + + align:start position:0% + +like ex-wife it's like I'm sorry they + + align:start position:0% +like ex-wife it's like I'm sorry they + + + align:start position:0% +like ex-wife it's like I'm sorry they +used to hate the epsilon D epsilon ijk + + align:start position:0% +used to hate the epsilon D epsilon ijk + + + align:start position:0% +used to hate the epsilon D epsilon ijk +yes + + align:start position:0% + + + + align:start position:0% + +okay let's just let's just do this a + + align:start position:0% +okay let's just let's just do this a + + + align:start position:0% +okay let's just let's just do this a +little bit let's say we have LX and ly + + align:start position:0% +little bit let's say we have LX and ly + + + align:start position:0% +little bit let's say we have LX and ly +well we know that that's going to give + + align:start position:0% +well we know that that's going to give + + + align:start position:0% +well we know that that's going to give +LZ okay and X Y Z IJ K that's cyclic + + align:start position:0% +LZ okay and X Y Z IJ K that's cyclic + + + align:start position:0% +LZ okay and X Y Z IJ K that's cyclic +order that's okay we say that's that's + + align:start position:0% +order that's okay we say that's that's + + + align:start position:0% +order that's okay we say that's that's +Homebase and if we have Y X Z that would + + align:start position:0% +Homebase and if we have Y X Z that would + + + align:start position:0% +Homebase and if we have Y X Z that would +be anti cyclic and so that would be a + + align:start position:0% +be anti cyclic and so that would be a + + + align:start position:0% +be anti cyclic and so that would be a +minus sign you know that just by looking + + align:start position:0% +minus sign you know that just by looking + + + align:start position:0% +minus sign you know that just by looking +at this and say oh if we switch this the + + align:start position:0% +at this and say oh if we switch this the + + + align:start position:0% +at this and say oh if we switch this the +sign of the commutator has to switch + + align:start position:0% +sign of the commutator has to switch + + + align:start position:0% +sign of the commutator has to switch +okay there's a lot of stuff loaded in + + align:start position:0% +okay there's a lot of stuff loaded in + + + align:start position:0% +okay there's a lot of stuff loaded in +there and once you've sort of processed + + align:start position:0% +there and once you've sort of processed + + + align:start position:0% +there and once you've sort of processed +it you know it becomes automatic and you + + align:start position:0% +it you know it becomes automatic and you + + + align:start position:0% +it you know it becomes automatic and you +forget the beauty of it okay so are you + + align:start position:0% +forget the beauty of it okay so are you + + + align:start position:0% +forget the beauty of it okay so are you +satisfied everybody else all right so + + align:start position:0% +satisfied everybody else all right so + + + align:start position:0% +satisfied everybody else all right so +now let's do another one let's look at L + + align:start position:0% +now let's do another one let's look at L + + + align:start position:0% +now let's do another one let's look at L +squared L plus minus well this one is + + align:start position:0% +squared L plus minus well this one is + + + align:start position:0% +squared L plus minus well this one is +super easy because we already know that + + align:start position:0% +super easy because we already know that + + + align:start position:0% +super easy because we already know that +l squared commutes with LX ly and LZ so + + align:start position:0% +l squared commutes with LX ly and LZ so + + + align:start position:0% +l squared commutes with LX ly and LZ so +I just need to just write zero here + + align:start position:0% +I just need to just write zero here + + + align:start position:0% +I just need to just write zero here +because this is LX plus or minus L ily + + align:start position:0% +because this is LX plus or minus L ily + + + align:start position:0% +because this is LX plus or minus L ily +and we know L does l squared commutes + + align:start position:0% +and we know L does l squared commutes + + + align:start position:0% +and we know L does l squared commutes +with both of them okay + + align:start position:0% + + + + align:start position:0% + +all right now comes the abstract and + + align:start position:0% +all right now comes the abstract and + + + align:start position:0% +all right now comes the abstract and +weird stuff we're starting to use the + + align:start position:0% +weird stuff we're starting to use the + + + align:start position:0% +weird stuff we're starting to use the +commutator z-- to derive the matrix + + align:start position:0% +commutator z-- to derive the matrix + + + align:start position:0% +commutator z-- to derive the matrix +elements and selection rules okay so let + + align:start position:0% +elements and selection rules okay so let + + + align:start position:0% +elements and selection rules okay so let +us say that we have some function which + + align:start position:0% +us say that we have some function which + + + align:start position:0% +us say that we have some function which +is an eigen function of l squared and LZ + + align:start position:0% +is an eigen function of l squared and LZ + + + align:start position:0% +is an eigen function of l squared and LZ +and so we're entitled to say that l + + align:start position:0% +and so we're entitled to say that l + + + align:start position:0% +and so we're entitled to say that l +squared operating on this function gives + + align:start position:0% +squared operating on this function gives + + + align:start position:0% +squared operating on this function gives +an eigenvalue we call L lambda and we + + align:start position:0% +an eigenvalue we call L lambda and we + + + align:start position:0% +an eigenvalue we call L lambda and we +can also say the LZ operating on the + + align:start position:0% +can also say the LZ operating on the + + + align:start position:0% +can also say the LZ operating on the +function gives a different a different + + align:start position:0% +function gives a different a different + + + align:start position:0% +function gives a different a different +constant mu now this lambda mu have no + + align:start position:0% +constant mu now this lambda mu have no + + + align:start position:0% +constant mu now this lambda mu have no +significance they're just numbers + + align:start position:0% +significance they're just numbers + + + align:start position:0% +significance they're just numbers +there's not something that's going to + + align:start position:0% +there's not something that's going to + + + align:start position:0% +there's not something that's going to +pop up here that says oh yeah that's + + align:start position:0% +pop up here that says oh yeah that's + + + align:start position:0% +pop up here that says oh yeah that's +this means something okay so now we're + + align:start position:0% +this means something okay so now we're + + + align:start position:0% +this means something okay so now we're +going to use the fact that this function + + align:start position:0% +going to use the fact that this function + + + align:start position:0% +going to use the fact that this function +which we're allowed to have as a + + align:start position:0% +which we're allowed to have as a + + + align:start position:0% +which we're allowed to have as a +simultaneous eigen function of l squared + + align:start position:0% +simultaneous eigen function of l squared + + + align:start position:0% +simultaneous eigen function of l squared +LC with its own set of eigen values this + + align:start position:0% +LC with its own set of eigen values this + + + align:start position:0% +LC with its own set of eigen values this +function we're going to operate on it + + align:start position:0% +function we're going to operate on it + + + align:start position:0% +function we're going to operate on it +and derive some useful results that all + + align:start position:0% +and derive some useful results that all + + + align:start position:0% +and derive some useful results that all +are based on the commutation rules so + + align:start position:0% +are based on the commutation rules so + + + align:start position:0% +are based on the commutation rules so +let us take L square operating on L plus + + align:start position:0% +let us take L square operating on L plus + + + align:start position:0% +let us take L square operating on L plus +minus times F and we know that L plus + + align:start position:0% +minus times F and we know that L plus + + + align:start position:0% +minus times F and we know that L plus +minus commutes with l squared so we can + + align:start position:0% +minus commutes with l squared so we can + + + align:start position:0% +minus commutes with l squared so we can +write L plus minus l squared F but l + + align:start position:0% +write L plus minus l squared F but l + + + align:start position:0% +write L plus minus l squared F but l +squared operating on F gives lambda we + + align:start position:0% +squared operating on F gives lambda we + + + align:start position:0% +squared operating on F gives lambda we +have L plus minus lambda + + align:start position:0% + + + + align:start position:0% + +oh isn't that interesting we have lambda + + align:start position:0% +oh isn't that interesting we have lambda + + + align:start position:0% +oh isn't that interesting we have lambda +times L plus minus F L plus minus F so + + align:start position:0% +times L plus minus F L plus minus F so + + + align:start position:0% +times L plus minus F L plus minus F so +it's saying that this thing is an + + align:start position:0% +it's saying that this thing is an + + + align:start position:0% +it's saying that this thing is an +eigenfunction of l squared with + + align:start position:0% +eigenfunction of l squared with + + + align:start position:0% +eigenfunction of l squared with +eigenvalue lambda well we knew that so L + + align:start position:0% +eigenvalue lambda well we knew that so L + + + align:start position:0% +eigenvalue lambda well we knew that so L +plus minus operating on F does not + + align:start position:0% + + + + align:start position:0% + +change lambda the eigenvalue l squared + + align:start position:0% + + + + align:start position:0% + +okay now let's use another one let's use + + align:start position:0% +okay now let's use another one let's use + + + align:start position:0% +okay now let's use another one let's use +LZ l plus - well I derived that it's + + align:start position:0% +LZ l plus - well I derived that it's + + + align:start position:0% +LZ l plus - well I derived that it's +plus or minus H bar times L plus - and + + align:start position:0% +plus or minus H bar times L plus - and + + + align:start position:0% +plus or minus H bar times L plus - and +if I didn't derive it I should have but + + align:start position:0% +if I didn't derive it I should have but + + + align:start position:0% +if I didn't derive it I should have but +I'm pretty sure I did and and so now + + align:start position:0% +I'm pretty sure I did and and so now + + + align:start position:0% +I'm pretty sure I did and and so now +what we can do is write LZ L plus minus + + align:start position:0% +what we can do is write LZ L plus minus + + + align:start position:0% +what we can do is write LZ L plus minus +minus L plus minus L Z is equal to h + + align:start position:0% +minus L plus minus L Z is equal to h + + + align:start position:0% +minus L plus minus L Z is equal to h +plus or minus H bar plus - and so + + align:start position:0% + + + + align:start position:0% + +let's stick in a function on the right F + + align:start position:0% +let's stick in a function on the right F + + + align:start position:0% +let's stick in a function on the right F +F F okay so now we have these operators + + align:start position:0% +F F okay so now we have these operators + + + align:start position:0% +F F okay so now we have these operators +operating on the same function and okay + + align:start position:0% +operating on the same function and okay + + + align:start position:0% +operating on the same function and okay +well we don't yet know what L plus minus + + align:start position:0% +well we don't yet know what L plus minus + + + align:start position:0% +well we don't yet know what L plus minus +does have but we know what LZ does to it + + align:start position:0% +does have but we know what LZ does to it + + + align:start position:0% +does have but we know what LZ does to it +and so what we can write immediately is + + align:start position:0% +and so what we can write immediately is + + + align:start position:0% +and so what we can write immediately is +that LZ operating on L plus - yeah is + + align:start position:0% +that LZ operating on L plus - yeah is + + + align:start position:0% +that LZ operating on L plus - yeah is +equal to plus or minus h-bar L plus + + align:start position:0% +equal to plus or minus h-bar L plus + + + align:start position:0% +equal to plus or minus h-bar L plus +minus F plus mu L plus minus F nice + + align:start position:0% +minus F plus mu L plus minus F nice + + + align:start position:0% +minus F plus mu L plus minus F nice +interesting so we see that we can + + align:start position:0% +interesting so we see that we can + + + align:start position:0% +interesting so we see that we can +rearrange this and we could write plus + + align:start position:0% +rearrange this and we could write plus + + + align:start position:0% +rearrange this and we could write plus +minus h-bar L plus minus F is equal to + + align:start position:0% +minus h-bar L plus minus F is equal to + + + align:start position:0% +minus h-bar L plus minus F is equal to +mu L plus minus F plus LZ L plus minus + + align:start position:0% + + + + align:start position:0% + +that's a tomorrow okay so oh I'm sorry + + align:start position:0% +that's a tomorrow okay so oh I'm sorry + + + align:start position:0% +that's a tomorrow okay so oh I'm sorry +L plus minus half in there okay what's + + align:start position:0% +L plus minus half in there okay what's + + + align:start position:0% +L plus minus half in there okay what's +this telling us so we can simply combine + + align:start position:0% +this telling us so we can simply combine + + + align:start position:0% +this telling us so we can simply combine +these terms we have the L plus minus F + + align:start position:0% +these terms we have the L plus minus F + + + align:start position:0% +these terms we have the L plus minus F +here and so we have + and so we can + + align:start position:0% +here and so we have + and so we can + + + align:start position:0% +here and so we have + and so we can +write mu plus h-bar times L plus minus F + + align:start position:0% +write mu plus h-bar times L plus minus F + + + align:start position:0% +write mu plus h-bar times L plus minus F +that's the point okay so we have this + + align:start position:0% +that's the point okay so we have this + + + align:start position:0% +that's the point okay so we have this +operator operating I'm sorry the first + + align:start position:0% +operator operating I'm sorry the first + + + align:start position:0% +operator operating I'm sorry the first +line goes straight there yep so I took + + align:start position:0% +line goes straight there yep so I took + + + align:start position:0% +line goes straight there yep so I took +this thing over to here but the so let's + + align:start position:0% +this thing over to here but the so let's + + + align:start position:0% +this thing over to here but the so let's +just rewrite that again we have L Z L + + align:start position:0% +just rewrite that again we have L Z L + + + align:start position:0% +just rewrite that again we have L Z L +plus minus F is equal to this and so + + align:start position:0% +plus minus F is equal to this and so + + + align:start position:0% +plus minus F is equal to this and so +here we have mu the eigenvalue and it's + + align:start position:0% +here we have mu the eigenvalue and it's + + + align:start position:0% +here we have mu the eigenvalue and it's +been increased by h-bar and so what that + + align:start position:0% +been increased by h-bar and so what that + + + align:start position:0% +been increased by h-bar and so what that +tells us is that we have a manifold of + + align:start position:0% +tells us is that we have a manifold of + + + align:start position:0% +tells us is that we have a manifold of +levels u etc so we get us a manifold of + + align:start position:0% +levels u etc so we get us a manifold of + + + align:start position:0% +levels u etc so we get us a manifold of +levels that are equally spaced spaced by + + align:start position:0% +levels that are equally spaced spaced by + + + align:start position:0% +levels that are equally spaced spaced by +H bars + + align:start position:0% + + + + align:start position:0% + +- right yeah okay so we have this + + align:start position:0% +- right yeah okay so we have this + + + align:start position:0% +- right yeah okay so we have this +manifold of levels and so what we could + + align:start position:0% +manifold of levels and so what we could + + + align:start position:0% +manifold of levels and so what we could +say as well this isn't going to go + + align:start position:0% +say as well this isn't going to go + + + align:start position:0% +say as well this isn't going to go +forever this is going to have a highest + + align:start position:0% +forever this is going to have a highest + + + align:start position:0% +forever this is going to have a highest +this is a ladder of equally spaced + + align:start position:0% +this is a ladder of equally spaced + + + align:start position:0% +this is a ladder of equally spaced +levels and it'll have a highest and the + + align:start position:0% +levels and it'll have a highest and the + + + align:start position:0% +levels and it'll have a highest and the +lowest member and so we can we can say + + align:start position:0% +lowest member and so we can we can say + + + align:start position:0% +lowest member and so we can we can say +alright well suppose we have F max you + + align:start position:0% +alright well suppose we have F max you + + + align:start position:0% +alright well suppose we have F max you +and we have L plus operating on it + + align:start position:0% +and we have L plus operating on it + + + align:start position:0% +and we have L plus operating on it +that's going to give zero and we at the + + align:start position:0% +that's going to give zero and we at the + + + align:start position:0% +that's going to give zero and we at the +same time we could say we have L minus + + align:start position:0% +same time we could say we have L minus + + + align:start position:0% +same time we could say we have L minus +min you that's gonna give zero we're + + align:start position:0% +min you that's gonna give zero we're + + + align:start position:0% +min you that's gonna give zero we're +gonna use both of these okay now I'm + + align:start position:0% +gonna use both of these okay now I'm + + + align:start position:0% +gonna use both of these okay now I'm +just gonna leave that there oh I'm not + + align:start position:0% +just gonna leave that there oh I'm not + + + align:start position:0% +just gonna leave that there oh I'm not +I'm gonna say all right so since since + + align:start position:0% +I'm gonna say all right so since since + + + align:start position:0% +I'm gonna say all right so since since +we have this arrangement all right I am + + align:start position:0% +we have this arrangement all right I am + + + align:start position:0% +we have this arrangement all right I am +skipping something and I don't want to + + align:start position:0% +skipping something and I don't want to + + + align:start position:0% +skipping something and I don't want to +skip it so if we have L plus operating + + align:start position:0% +skip it so if we have L plus operating + + + align:start position:0% +skip it so if we have L plus operating +on the maximum value of a view we get + + align:start position:0% +on the maximum value of a view we get + + + align:start position:0% +on the maximum value of a view we get +zero and the next one down is down by an + + align:start position:0% +zero and the next one down is down by an + + + align:start position:0% +zero and the next one down is down by an +integer number of L and so we can say + + align:start position:0% +integer number of L and so we can say + + + align:start position:0% +integer number of L and so we can say +that L Z operating on F max mu is equal + + align:start position:0% +that L Z operating on F max mu is equal + + + align:start position:0% +that L Z operating on F max mu is equal +to H bar L some integer now this this L + + align:start position:0% +to H bar L some integer now this this L + + + align:start position:0% +to H bar L some integer now this this L +is chosen with some prejudice yes + + align:start position:0% + + + + align:start position:0% + +okay now I have to cheat I'm going to + + align:start position:0% +okay now I have to cheat I'm going to + + + align:start position:0% +okay now I have to cheat I'm going to +apply an argument which is not based on + + align:start position:0% +apply an argument which is not based on + + + align:start position:0% +apply an argument which is not based on +just abstract vectors we have an angular + + align:start position:0% +just abstract vectors we have an angular + + + align:start position:0% +just abstract vectors we have an angular +momentum it has a certain length we know + + align:start position:0% +momentum it has a certain length we know + + + align:start position:0% +momentum it has a certain length we know +the projection of that angular momentum + + align:start position:0% +the projection of that angular momentum + + + align:start position:0% +the projection of that angular momentum +on some axis cannot be longer than its + + align:start position:0% +on some axis cannot be longer than its + + + align:start position:0% +on some axis cannot be longer than its +length okay that's so I'm you know I'm + + align:start position:0% +length okay that's so I'm you know I'm + + + align:start position:0% +length okay that's so I'm you know I'm +uncomfortable making an argument because + + align:start position:0% +uncomfortable making an argument because + + + align:start position:0% +uncomfortable making an argument because +I should be able to to say it you know + + align:start position:0% +I should be able to to say it you know + + + align:start position:0% +I should be able to to say it you know +in a more abstract way but this is in + + align:start position:0% +in a more abstract way but this is in + + + align:start position:0% +in a more abstract way but this is in +fact and you know if we we know there + + align:start position:0% +fact and you know if we we know there + + + align:start position:0% +fact and you know if we we know there +cannot be an infinite number of + + align:start position:0% +cannot be an infinite number of + + + align:start position:0% +cannot be an infinite number of +projection quantum numbers values of the + + align:start position:0% +projection quantum numbers values of the + + + align:start position:0% +projection quantum numbers values of the +projection quantum number that are + + align:start position:0% +projection quantum number that are + + + align:start position:0% +projection quantum number that are +reached by applying L plus and L - they + + align:start position:0% +reached by applying L plus and L - they + + + align:start position:0% +reached by applying L plus and L - they +must be limited and and so we're going + + align:start position:0% +must be limited and and so we're going + + + align:start position:0% +must be limited and and so we're going +to call the maximum value of mu H bar L + + align:start position:0% +to call the maximum value of mu H bar L + + + align:start position:0% +to call the maximum value of mu H bar L +or L okay now I have to derive a new + + align:start position:0% +or L okay now I have to derive a new + + + align:start position:0% +or L okay now I have to derive a new +commutation rule based on the original + + align:start position:0% +commutation rule based on the original + + + align:start position:0% +commutation rule based on the original +one no it's not let's not erase this we + + align:start position:0% +one no it's not let's not erase this we + + + align:start position:0% +one no it's not let's not erase this we +might want to see it again + + align:start position:0% + + + + align:start position:0% + +okay so let's ask well what does this + + align:start position:0% +okay so let's ask well what does this + + + align:start position:0% +okay so let's ask well what does this +combination of operators do okay well + + align:start position:0% +combination of operators do okay well + + + align:start position:0% +combination of operators do okay well +this is surely equal to LX squared and + + align:start position:0% +this is surely equal to LX squared and + + + align:start position:0% +this is surely equal to LX squared and +we get a might we get a plus I and a + + align:start position:0% +we get a might we get a plus I and a + + + align:start position:0% +we get a might we get a plus I and a +minus I and so it's going to be plus ly + + align:start position:0% +minus I and so it's going to be plus ly + + + align:start position:0% +minus I and so it's going to be plus ly +squared + + align:start position:0% +squared + + + align:start position:0% +squared +and then we get I times L by L X and we + + align:start position:0% +and then we get I times L by L X and we + + + align:start position:0% +and then we get I times L by L X and we +get a minus I times LX ly this is l + + align:start position:0% +get a minus I times LX ly this is l + + + align:start position:0% +get a minus I times LX ly this is l +squared minus LZ squared right we have + + align:start position:0% +squared minus LZ squared right we have + + + align:start position:0% +squared minus LZ squared right we have +the square of two components of l + + align:start position:0% +the square of two components of l + + + align:start position:0% +the square of two components of l +squared and so this is equal to the the + + align:start position:0% +squared and so this is equal to the the + + + align:start position:0% +squared and so this is equal to the the +difference and and so and now we we + + align:start position:0% +difference and and so and now we we + + + align:start position:0% +difference and and so and now we we +express this as I x ly LX right and what + + align:start position:0% +express this as I x ly LX right and what + + + align:start position:0% +express this as I x ly LX right and what +is this this is plus IH bar LZ l LX okay + + align:start position:0% +is this this is plus IH bar LZ l LX okay + + + align:start position:0% +is this this is plus IH bar LZ l LX okay +let's just this is yes X and that's LZ I + + align:start position:0% +let's just this is yes X and that's LZ I + + + align:start position:0% +let's just this is yes X and that's LZ I +didn't like what I wrote because I I + + align:start position:0% +didn't like what I wrote because I I + + + align:start position:0% +didn't like what I wrote because I I +want to have everything but the X but + + align:start position:0% +want to have everything but the X but + + + align:start position:0% +want to have everything but the X but +the Z and the l squared disappearing and + + align:start position:0% +the Z and the l squared disappearing and + + + align:start position:0% +the Z and the l squared disappearing and +so we get that we have l squared minus + + align:start position:0% +so we get that we have l squared minus + + + align:start position:0% +so we get that we have l squared minus +LZ squared and then we have plus IH bar + + align:start position:0% +LZ squared and then we have plus IH bar + + + align:start position:0% +LZ squared and then we have plus IH bar +LZ and I have a I lost the plus and + + align:start position:0% +LZ and I have a I lost the plus and + + + align:start position:0% +LZ and I have a I lost the plus and +minus + + align:start position:0% +minus + + + align:start position:0% +minus +no I didn't okay that's it and so we can + + align:start position:0% +no I didn't okay that's it and so we can + + + align:start position:0% +no I didn't okay that's it and so we can +rearrange this and say L squared is + + align:start position:0% +rearrange this and say L squared is + + + align:start position:0% +rearrange this and say L squared is +equal to LZ squared minus or plus h bar + + align:start position:0% +equal to LZ squared minus or plus h bar + + + align:start position:0% +equal to LZ squared minus or plus h bar +LZ plus plus minus minus plus e okay so + + align:start position:0% +LZ plus plus minus minus plus e okay so + + + align:start position:0% +LZ plus plus minus minus plus e okay so +we can use this equation + + align:start position:0% +we can use this equation + + + align:start position:0% +we can use this equation +okay they're not and to derive some good + + align:start position:0% +okay they're not and to derive some good + + + align:start position:0% +okay they're not and to derive some good +stuff I better erase some stuff for + + align:start position:0% +stuff I better erase some stuff for + + + align:start position:0% +stuff I better erase some stuff for +accessing okay we're actually pretty + + align:start position:0% +accessing okay we're actually pretty + + + align:start position:0% +accessing okay we're actually pretty +close to the end so I might actually + + align:start position:0% +close to the end so I might actually + + + align:start position:0% +close to the end so I might actually +finish this okay so we're gonna use this + + align:start position:0% +finish this okay so we're gonna use this + + + align:start position:0% +finish this okay so we're gonna use this +equation to find we want lamda the value + + align:start position:0% +equation to find we want lamda the value + + + align:start position:0% +equation to find we want lamda the value +of lambda for the top of the manifold + + align:start position:0% +of lambda for the top of the manifold + + + align:start position:0% +of lambda for the top of the manifold +over here so we yl squared F max mu and + + align:start position:0% +over here so we yl squared F max mu and + + + align:start position:0% +over here so we yl squared F max mu and +we know we have an equation here which + + align:start position:0% +we know we have an equation here which + + + align:start position:0% +we know we have an equation here which +enables us to evaluate what what the + + align:start position:0% +enables us to evaluate what what the + + + align:start position:0% +enables us to evaluate what what the +consequences of that will be in it the + + align:start position:0% +consequences of that will be in it the + + + align:start position:0% +consequences of that will be in it the +LZ squared F max u minus or plus h bar + + align:start position:0% +LZ squared F max u minus or plus h bar + + + align:start position:0% +LZ squared F max u minus or plus h bar +LZ F max okay so if we take the bottom + + align:start position:0% +LZ F max okay so if we take the bottom + + + align:start position:0% +LZ F max okay so if we take the bottom +sign then L plus on F max is going to + + align:start position:0% +sign then L plus on F max is going to + + + align:start position:0% +sign then L plus on F max is going to +give zero so we're looking at the bottom + + align:start position:0% +give zero so we're looking at the bottom + + + align:start position:0% +give zero so we're looking at the bottom +sign and we have a zero here and so we + + align:start position:0% +sign and we have a zero here and so we + + + align:start position:0% +sign and we have a zero here and so we +have L squared F max U is equal to L Z + + align:start position:0% +have L squared F max U is equal to L Z + + + align:start position:0% +have L squared F max U is equal to L Z +squared + + align:start position:0% +squared + + + align:start position:0% +squared +if max minus or plus h bar LZ max mu + + align:start position:0% +if max minus or plus h bar LZ max mu + + + align:start position:0% +if max minus or plus h bar LZ max mu +plus zero interesting okay so we know + + align:start position:0% +plus zero interesting okay so we know + + + align:start position:0% +plus zero interesting okay so we know +that LZ is going to give so we're going + + align:start position:0% +that LZ is going to give so we're going + + + align:start position:0% +that LZ is going to give so we're going +to get an H bar squared and mu max + + align:start position:0% + + + + align:start position:0% + +we're gonna get a minus H bar H bar mu + + align:start position:0% +we're gonna get a minus H bar H bar mu + + + align:start position:0% +we're gonna get a minus H bar H bar mu +max so what this is telling us is that l + + align:start position:0% +max so what this is telling us is that l + + + align:start position:0% +max so what this is telling us is that l +squared operate on FX + + align:start position:0% +squared operate on FX + + + align:start position:0% +squared operate on FX +mu is given by L because we we said that + + align:start position:0% +mu is given by L because we we said that + + + align:start position:0% +mu is given by L because we we said that +we're going to take the maximum value of + + align:start position:0% +we're going to take the maximum value of + + + align:start position:0% +we're going to take the maximum value of +mu to be H bar L so so I shouldn't have + + align:start position:0% +mu to be H bar L so so I shouldn't have + + + align:start position:0% +mu to be H bar L so so I shouldn't have +had an extra H bar here okay so we get + + align:start position:0% +had an extra H bar here okay so we get + + + align:start position:0% +had an extra H bar here okay so we get +this result so lambda so l squared + + align:start position:0% +this result so lambda so l squared + + + align:start position:0% +this result so lambda so l squared +operating this gives the U so it's + + align:start position:0% +operating this gives the U so it's + + + align:start position:0% +operating this gives the U so it's +telling us that l squared F max mu is + + align:start position:0% +telling us that l squared F max mu is + + + align:start position:0% +telling us that l squared F max mu is +equal to H bar squared ll plus 1 now + + align:start position:0% +equal to H bar squared ll plus 1 now + + + align:start position:0% +equal to H bar squared ll plus 1 now +that is why we chose that that constant + + align:start position:0% +that is why we chose that that constant + + + align:start position:0% +that is why we chose that that constant +to be L and we do a similar argument for + + align:start position:0% +to be L and we do a similar argument for + + + align:start position:0% +to be L and we do a similar argument for +the lowest rung of the ladder + + align:start position:0% + + + + align:start position:0% + +and for the lowest rung of the ladder we + + align:start position:0% +and for the lowest rung of the ladder we + + + align:start position:0% +and for the lowest rung of the ladder we +know there must be lowest rung and so we + + align:start position:0% +know there must be lowest rung and so we + + + align:start position:0% +know there must be lowest rung and so we +will simply say okay for the lowest rung + + align:start position:0% +will simply say okay for the lowest rung + + + align:start position:0% +will simply say okay for the lowest rung +of the ladder we're going to get that + + align:start position:0% +of the ladder we're going to get that + + + align:start position:0% +of the ladder we're going to get that +that mu is equal to H bar lambda bar mu + + align:start position:0% +that mu is equal to H bar lambda bar mu + + + align:start position:0% +that mu is equal to H bar lambda bar mu +min okay and we could do some stuff and + + align:start position:0% +min okay and we could do some stuff and + + + align:start position:0% +min okay and we could do some stuff and +we discover that lambda has to be equal + + align:start position:0% +we discover that lambda has to be equal + + + align:start position:0% +we discover that lambda has to be equal +to H bar squared ll plus 1 and using the + + align:start position:0% +to H bar squared ll plus 1 and using the + + + align:start position:0% +to H bar squared ll plus 1 and using the +other this other relationship and the + + align:start position:0% +other this other relationship and the + + + align:start position:0% +other this other relationship and the +top sign we get H bar squared L bar L + + align:start position:0% +top sign we get H bar squared L bar L + + + align:start position:0% +top sign we get H bar squared L bar L +bar minus 1 okay and there's two wages + + align:start position:0% +bar minus 1 okay and there's two wages + + + align:start position:0% +bar minus 1 okay and there's two wages +at two ways to solve this one is that L + + align:start position:0% +at two ways to solve this one is that L + + + align:start position:0% +at two ways to solve this one is that L +is equal to minus L bar and the other is + + align:start position:0% +is equal to minus L bar and the other is + + + align:start position:0% +is equal to minus L bar and the other is +that L bar is equal to L plus 1 well + + align:start position:0% +that L bar is equal to L plus 1 well + + + align:start position:0% +that L bar is equal to L plus 1 well +this is the lowest rung of the ladder + + align:start position:0% +this is the lowest rung of the ladder + + + align:start position:0% +this is the lowest rung of the ladder +and wait a minute let me just make sure + + align:start position:0% +and wait a minute let me just make sure + + + align:start position:0% +and wait a minute let me just make sure +I'm doing the logic correctly okay it's + + align:start position:0% +I'm doing the logic correctly okay it's + + + align:start position:0% +I'm doing the logic correctly okay it's +not this one okay here so this is the + + align:start position:0% +not this one okay here so this is the + + + align:start position:0% +not this one okay here so this is the +lowest rung of the ladder and L bar is + + align:start position:0% +lowest rung of the ladder and L bar is + + + align:start position:0% +lowest rung of the ladder and L bar is +supposedly larger than L can't be so + + align:start position:0% +supposedly larger than L can't be so + + + align:start position:0% +supposedly larger than L can't be so +this is impossible this is correct and + + align:start position:0% +this is impossible this is correct and + + + align:start position:0% +this is impossible this is correct and +what we end up getting is this + + align:start position:0% +what we end up getting is this + + + align:start position:0% +what we end up getting is this +relationship and so mu can be equal to + + align:start position:0% +relationship and so mu can be equal to + + + align:start position:0% +relationship and so mu can be equal to +and this is L L minus 1 minus L steps of + + align:start position:0% +and this is L L minus 1 minus L steps of + + + align:start position:0% +and this is L L minus 1 minus L steps of + + align:start position:0% + + + + align:start position:0% + +this seems very weird and not very + + align:start position:0% +this seems very weird and not very + + + align:start position:0% +this seems very weird and not very +interesting until you say well how do i + + align:start position:0% +interesting until you say well how do i + + + align:start position:0% +interesting until you say well how do i +satisfy this + + align:start position:0% +satisfy this + + + align:start position:0% +satisfy this +well if L is an integer it's obvious if + + align:start position:0% +well if L is an integer it's obvious if + + + align:start position:0% +well if L is an integer it's obvious if +L is a half integer it shouldn't be + + align:start position:0% +L is a half integer it shouldn't be + + + align:start position:0% +L is a half integer it shouldn't be +quite so obvious but it's true so we can + + align:start position:0% +quite so obvious but it's true so we can + + + align:start position:0% +quite so obvious but it's true so we can +have integer hell and half integer L + + align:start position:0% + + + + align:start position:0% + +that's weird + + align:start position:0% +that's weird + + + align:start position:0% +that's weird +we can show no connection between the + + align:start position:0% +we can show no connection between the + + + align:start position:0% +we can show no connection between the +integer ELLs and the have integer else + + align:start position:0% +integer ELLs and the have integer else + + + align:start position:0% +integer ELLs and the have integer else +they belong to completely different + + align:start position:0% +they belong to completely different + + + align:start position:0% +they belong to completely different +problems but this abstract argument says + + align:start position:0% +problems but this abstract argument says + + + align:start position:0% +problems but this abstract argument says +yeah we can have integer else and half + + align:start position:0% +yeah we can have integer else and half + + + align:start position:0% +yeah we can have integer else and half +integer else and if we have have + + align:start position:0% +integer else and if we have have + + + align:start position:0% +integer else and if we have have +electron we call it electron spin + + align:start position:0% +electron we call it electron spin + + + align:start position:0% +electron we call it electron spin +because we want it to be an angular + + align:start position:0% +because we want it to be an angular + + + align:start position:0% +because we want it to be an angular +momentum spin as sort of an angular + + align:start position:0% +momentum spin as sort of an angular + + + align:start position:0% +momentum spin as sort of an angular +momentum or nuclear spin and we discover + + align:start position:0% +momentum or nuclear spin and we discover + + + align:start position:0% +momentum or nuclear spin and we discover +that there are patterns of energy levels + + align:start position:0% +that there are patterns of energy levels + + + align:start position:0% +that there are patterns of energy levels +which enable us to count the number of + + align:start position:0% +which enable us to count the number of + + + align:start position:0% +which enable us to count the number of +projection components and if you have an + + align:start position:0% +projection components and if you have an + + + align:start position:0% +projection components and if you have an +integer al you get 2 L plus 1 components + + align:start position:0% +integer al you get 2 L plus 1 components + + + align:start position:0% +integer al you get 2 L plus 1 components +which is an odd number and if it's half + + align:start position:0% +which is an odd number and if it's half + + + align:start position:0% +which is an odd number and if it's half +integer you get 2 L plus 1 components + + align:start position:0% +integer you get 2 L plus 1 components + + + align:start position:0% +integer you get 2 L plus 1 components +which is an even number and so it turns + + align:start position:0% +which is an even number and so it turns + + + align:start position:0% +which is an even number and so it turns +out that our definition of an angular + + align:start position:0% +out that our definition of an angular + + + align:start position:0% +out that our definition of an angular +momentum is more general than we thought + + align:start position:0% +momentum is more general than we thought + + + align:start position:0% +momentum is more general than we thought +it allows there to be both integer and + + align:start position:0% +it allows there to be both integer and + + + align:start position:0% +it allows there to be both integer and +happen at your angular momenta and this + + align:start position:0% +happen at your angular momenta and this + + + align:start position:0% +happen at your angular momenta and this +means we can have angular momenta where + + align:start position:0% +means we can have angular momenta where + + + align:start position:0% +means we can have angular momenta where +we can't define it in terms of R cross P + + align:start position:0% +we can't define it in terms of R cross P + + + align:start position:0% +we can't define it in terms of R cross P +it's defined by the commutation rule + + align:start position:0% +it's defined by the commutation rule + + + align:start position:0% +it's defined by the commutation rule +it's more general it's more abstract + + align:start position:0% +it's more general it's more abstract + + + align:start position:0% +it's more general it's more abstract +it's beautiful + + align:start position:0% +it's beautiful + + + align:start position:0% +it's beautiful +and + + align:start position:0% +and + + + align:start position:0% +and +I don't have time to finish the job but + + align:start position:0% +I don't have time to finish the job but + + + align:start position:0% +I don't have time to finish the job but +in the notes you can see that we can + + align:start position:0% +in the notes you can see that we can + + + align:start position:0% +in the notes you can see that we can +derive the matrix elements for the + + align:start position:0% +derive the matrix elements for the + + + align:start position:0% +derive the matrix elements for the +raising and lowering operators too and + + align:start position:0% +raising and lowering operators too and + + + align:start position:0% +raising and lowering operators too and +the angular momentum matrix elements are + + align:start position:0% +the angular momentum matrix elements are + + + align:start position:0% +the angular momentum matrix elements are +that the L plus minus operating on a + + align:start position:0% +that the L plus minus operating on a + + + align:start position:0% +that the L plus minus operating on a +function gives this combination square + + align:start position:0% +function gives this combination square + + + align:start position:0% +function gives this combination square +root and it raises or lowers M so it's + + align:start position:0% +root and it raises or lowers M so it's + + + align:start position:0% +root and it raises or lowers M so it's +sort of like what we have for the A's + + align:start position:0% +sort of like what we have for the A's + + + align:start position:0% +sort of like what we have for the A's +and a daggers for the harmonic + + align:start position:0% +and a daggers for the harmonic + + + align:start position:0% +and a daggers for the harmonic +oscillator but it's not as good because + + align:start position:0% +oscillator but it's not as good because + + + align:start position:0% +oscillator but it's not as good because +you can't generate all the else you can + + align:start position:0% +you can't generate all the else you can + + + align:start position:0% +you can't generate all the else you can +generate the MC bells and that's great + + align:start position:0% +generate the MC bells and that's great + + + align:start position:0% +generate the MC bells and that's great +but you know there's there still + + align:start position:0% +but you know there's there still + + + align:start position:0% +but you know there's there still +something that remains to be done to + + align:start position:0% +something that remains to be done to + + + align:start position:0% +something that remains to be done to +generate the different else it's not a + + align:start position:0% +generate the different else it's not a + + + align:start position:0% +generate the different else it's not a +problem it's just there's not a simple + + align:start position:0% +problem it's just there's not a simple + + + align:start position:0% +problem it's just there's not a simple +way to do it at least not simple to me + + align:start position:0% +way to do it at least not simple to me + + + align:start position:0% +way to do it at least not simple to me +and so now anytime we're faced with a + + align:start position:0% +and so now anytime we're faced with a + + + align:start position:0% +and so now anytime we're faced with a +problem involving angular momenta we + + align:start position:0% +problem involving angular momenta we + + + align:start position:0% +problem involving angular momenta we +have a prayer of writing down the matrix + + align:start position:0% +have a prayer of writing down the matrix + + + align:start position:0% +have a prayer of writing down the matrix +elements without ever looking at the + + align:start position:0% +elements without ever looking at the + + + align:start position:0% +elements without ever looking at the +wave function without ever looking at a + + align:start position:0% +wave function without ever looking at a + + + align:start position:0% +wave function without ever looking at a +differential operator and we can also + + align:start position:0% +differential operator and we can also + + + align:start position:0% +differential operator and we can also +say well let's suppose we had you know + + align:start position:0% +say well let's suppose we had you know + + + align:start position:0% +say well let's suppose we had you know +some operator that involves L and s now + + align:start position:0% +some operator that involves L and s now + + + align:start position:0% +some operator that involves L and s now +that we know that we have this things + + align:start position:0% +that we know that we have this things + + + align:start position:0% +that we know that we have this things +and L plus s can be called J so now we + + align:start position:0% +and L plus s can be called J so now we + + + align:start position:0% +and L plus s can be called J so now we +have two different operators two + + align:start position:0% +have two different operators two + + + align:start position:0% +have two different operators two +different angular 1 we have s and we + + align:start position:0% +different angular 1 we have s and we + + + align:start position:0% +different angular 1 we have s and we +have the total of J well they're all + + align:start position:0% +have the total of J well they're all + + + align:start position:0% +have the total of J well they're all +angular momenta they're going to satisfy + + align:start position:0% +angular momenta they're going to satisfy + + + align:start position:0% +angular momenta they're going to satisfy +there's selection rules and matrix + + align:start position:0% +there's selection rules and matrix + + + align:start position:0% +there's selection rules and matrix +elements and we can calculate all of + + align:start position:0% +elements and we can calculate all of + + + align:start position:0% +elements and we can calculate all of +these matrix elements including things + + align:start position:0% +these matrix elements including things + + + align:start position:0% +these matrix elements including things +like l dot s and whatever and and so it + + align:start position:0% +like l dot s and whatever and and so it + + + align:start position:0% +like l dot s and whatever and and so it +just opens up a huge area where before + + align:start position:0% +just opens up a huge area where before + + + align:start position:0% +just opens up a huge area where before +you would say well I got a look at the + + align:start position:0% +you would say well I got a look at the + + + align:start position:0% +you would say well I got a look at the +wave function I got it a look at this + + align:start position:0% +wave function I got it a look at this + + + align:start position:0% +wave function I got it a look at this +integral no more but there's one thing + + align:start position:0% +integral no more but there's one thing + + + align:start position:0% +integral no more but there's one thing +and that is these arguments do not + + align:start position:0% +and that is these arguments do not + + + align:start position:0% +and that is these arguments do not +termen I mean when you take the square + + align:start position:0% +termen I mean when you take the square + + + align:start position:0% +termen I mean when you take the square +root of something you have a positive + + align:start position:0% +root of something you have a positive + + + align:start position:0% +root of something you have a positive +value in a negative value that + + align:start position:0% +value in a negative value that + + + align:start position:0% +value in a negative value that +corresponds to a phase ambiguity these + + align:start position:0% +corresponds to a phase ambiguity these + + + align:start position:0% +corresponds to a phase ambiguity these +arguments don't resolve that at some + + align:start position:0% +arguments don't resolve that at some + + + align:start position:0% +arguments don't resolve that at some +point you have to decide on the phase + + align:start position:0% +point you have to decide on the phase + + + align:start position:0% +point you have to decide on the phase +and be consistent and since you're never + + align:start position:0% +and be consistent and since you're never + + + align:start position:0% +and be consistent and since you're never +looking at wave functions that actually + + align:start position:0% +looking at wave functions that actually + + + align:start position:0% +looking at wave functions that actually +is a frequent source of error but that's + + align:start position:0% +is a frequent source of error but that's + + + align:start position:0% +is a frequent source of error but that's +the only defect in this this whole thing + + align:start position:0% +the only defect in this this whole thing + + + align:start position:0% +the only defect in this this whole thing +okay so that's it for the exam I will + + align:start position:0% +okay so that's it for the exam I will + + + align:start position:0% +okay so that's it for the exam I will +talk about something that will make you + + align:start position:0% +talk about something that will make you + + + align:start position:0% +talk about something that will make you +a little bit more comfortable about one + + align:start position:0% +a little bit more comfortable about one + + + align:start position:0% +a little bit more comfortable about one +of the exams some of these you have + + align:start position:0% +of the exams some of these you have + + + align:start position:0% +of the exams some of these you have +questions on Wednesday but it's not + + align:start position:0% +questions on Wednesday but it's not + + + align:start position:0% +questions on Wednesday but it's not +going to be tested \ No newline at end of file diff --git a/76dhtgZt38A.txt b/76dhtgZt38A.txt new file mode 100644 index 0000000000000000000000000000000000000000..fe80c71528fc18444e3e0096293e7b62a4f52d24 --- /dev/null +++ b/76dhtgZt38A.txt @@ -0,0 +1,9552 @@ +align:start position:0% + +all right let's get started + + align:start position:0% +all right let's get started + + + align:start position:0% +all right let's get started +welcome back to double06 today we are + + align:start position:0% +welcome back to double06 today we are + + + align:start position:0% +welcome back to double06 today we are +doing some of the coolest data + + align:start position:0% +doing some of the coolest data + + + align:start position:0% +doing some of the coolest data +structures we will see in this class + + align:start position:0% +structures we will see in this class + + + align:start position:0% +structures we will see in this class +maybe some of the coolest data + + align:start position:0% +maybe some of the coolest data + + + align:start position:0% +maybe some of the coolest data +structures ever binary trees + + align:start position:0% +structures ever binary trees + + + align:start position:0% +structures ever binary trees +uh you've certainly seen trees in many + + align:start position:0% +uh you've certainly seen trees in many + + + align:start position:0% +uh you've certainly seen trees in many +forms + + align:start position:0% +forms + + + align:start position:0% +forms +uh in the past including in this class + + align:start position:0% +uh in the past including in this class + + + align:start position:0% +uh in the past including in this class +we've talked to use trees as a lower + + align:start position:0% +we've talked to use trees as a lower + + + align:start position:0% +we've talked to use trees as a lower +bound tool + + align:start position:0% +bound tool + + + align:start position:0% +bound tool +for uh in the decision tree model + + align:start position:0% +for uh in the decision tree model + + + align:start position:0% +for uh in the decision tree model +but this lecture and the next lecture + + align:start position:0% +but this lecture and the next lecture + + + align:start position:0% +but this lecture and the next lecture +we're going to build + + align:start position:0% +we're going to build + + + align:start position:0% +we're going to build +one data structure that is almost + + align:start position:0% +one data structure that is almost + + + align:start position:0% +one data structure that is almost +superior to all data + + align:start position:0% +superior to all data + + + align:start position:0% +superior to all data +structures we have seen and can do + + align:start position:0% +structures we have seen and can do + + + align:start position:0% +structures we have seen and can do +almost anything + + align:start position:0% +almost anything + + + align:start position:0% +almost anything +really fast first recall all the data + + align:start position:0% +really fast first recall all the data + + + align:start position:0% +really fast first recall all the data +structures we've seen so far arrays + + align:start position:0% +structures we've seen so far arrays + + + align:start position:0% +structures we've seen so far arrays +linked lists + + align:start position:0% +linked lists + + + align:start position:0% +linked lists +dynamic arrays sorted arrays hash tables + + align:start position:0% +dynamic arrays sorted arrays hash tables + + + align:start position:0% +dynamic arrays sorted arrays hash tables +and the two sets of operations we're + + align:start position:0% +and the two sets of operations we're + + + align:start position:0% +and the two sets of operations we're +interested in supporting + + align:start position:0% +interested in supporting + + + align:start position:0% +interested in supporting +the two interfaces one was sequences + + align:start position:0% +the two interfaces one was sequences + + + align:start position:0% +the two interfaces one was sequences +where we're maintaining items in a + + align:start position:0% +where we're maintaining items in a + + + align:start position:0% +where we're maintaining items in a +specified order we want to be able to + + align:start position:0% +specified order we want to be able to + + + align:start position:0% +specified order we want to be able to +insert + + align:start position:0% +insert + + + align:start position:0% +insert +an item right after another item or + + align:start position:0% +an item right after another item or + + + align:start position:0% +an item right after another item or +delete an item in the middle of the list + + align:start position:0% +delete an item in the middle of the list + + + align:start position:0% +delete an item in the middle of the list +and always be able to access the ith + + align:start position:0% +and always be able to access the ith + + + align:start position:0% +and always be able to access the ith +item we haven't seen + + align:start position:0% +item we haven't seen + + + align:start position:0% +item we haven't seen +any good data structures for that + + align:start position:0% +any good data structures for that + + + align:start position:0% +any good data structures for that +problem we we're really good at + + align:start position:0% +problem we we're really good at + + + align:start position:0% +problem we we're really good at +inserting and deleting + + align:start position:0% +inserting and deleting + + + align:start position:0% +inserting and deleting +at the beginning or the end of the + + align:start position:0% +at the beginning or the end of the + + + align:start position:0% +at the beginning or the end of the +sequence but we haven't seen anything + + align:start position:0% +sequence but we haven't seen anything + + + align:start position:0% +sequence but we haven't seen anything +that's efficient at ins + + align:start position:0% +that's efficient at ins + + + align:start position:0% +that's efficient at ins +inserting in the middle of the list or + + align:start position:0% +inserting in the middle of the list or + + + align:start position:0% +inserting in the middle of the list or +deleting in the middle of the list + + align:start position:0% +deleting in the middle of the list + + + align:start position:0% +deleting in the middle of the list +linked list + + align:start position:0% +linked list + + + align:start position:0% +linked list +you can't even get to the middle in less + + align:start position:0% +you can't even get to the middle in less + + + align:start position:0% +you can't even get to the middle in less +than linear time + + align:start position:0% +than linear time + + + align:start position:0% +than linear time +uh array you can get to the middle but + + align:start position:0% +uh array you can get to the middle but + + + align:start position:0% +uh array you can get to the middle but +if you make any changes you have to do + + align:start position:0% +if you make any changes you have to do + + + align:start position:0% +if you make any changes you have to do +this shift which is very expensive + + align:start position:0% +this shift which is very expensive + + + align:start position:0% +this shift which is very expensive +so today or sorry next lecture for the + + align:start position:0% +so today or sorry next lecture for the + + + align:start position:0% +so today or sorry next lecture for the +first time we will see + + align:start position:0% +first time we will see + + + align:start position:0% +first time we will see +all of those operations efficient + + align:start position:0% + + + + align:start position:0% + +i'll mention our goal where efficient + + align:start position:0% +i'll mention our goal where efficient + + + align:start position:0% +i'll mention our goal where efficient +means + + align:start position:0% +means + + + align:start position:0% +means +logarithmic so we're not quite as good + + align:start position:0% +logarithmic so we're not quite as good + + + align:start position:0% +logarithmic so we're not quite as good +as linked lists and dynamic arrays at + + align:start position:0% +as linked lists and dynamic arrays at + + + align:start position:0% +as linked lists and dynamic arrays at +inserting and + + align:start position:0% +inserting and + + + align:start position:0% +inserting and +deleting at the ends those there that we + + align:start position:0% +deleting at the ends those there that we + + + align:start position:0% +deleting at the ends those there that we +achieve constant or constant amortized + + align:start position:0% +achieve constant or constant amortized + + + align:start position:0% +achieve constant or constant amortized +time + + align:start position:0% +time + + + align:start position:0% +time +but up to this log factor we're going to + + align:start position:0% +but up to this log factor we're going to + + + align:start position:0% +but up to this log factor we're going to +get the best of all worlds where we can + + align:start position:0% +get the best of all worlds where we can + + + align:start position:0% +get the best of all worlds where we can +solve + + align:start position:0% +solve + + + align:start position:0% +solve +all the things all the operations that + + align:start position:0% +all the things all the operations that + + + align:start position:0% +all the things all the operations that +don't + + align:start position:0% +don't + + + align:start position:0% +don't +build or iterate through the entire + + align:start position:0% +build or iterate through the entire + + + align:start position:0% +build or iterate through the entire +structure that of course takes linear + + align:start position:0% +structure that of course takes linear + + + align:start position:0% +structure that of course takes linear +time + + align:start position:0% +time + + + align:start position:0% +time +but we can do all the others in + + align:start position:0% +but we can do all the others in + + + align:start position:0% +but we can do all the others in +logarithmic time for sets + + align:start position:0% +logarithmic time for sets + + + align:start position:0% +logarithmic time for sets +sets were maintained maintaining a bunch + + align:start position:0% +sets were maintained maintaining a bunch + + + align:start position:0% +sets were maintained maintaining a bunch +of items which have + + align:start position:0% +of items which have + + + align:start position:0% +of items which have +intrinsic keys and we want to + + align:start position:0% +intrinsic keys and we want to + + + align:start position:0% +intrinsic keys and we want to +search by key so hash tables are great + + align:start position:0% +search by key so hash tables are great + + + align:start position:0% +search by key so hash tables are great +if you're only doing exact searches if + + align:start position:0% +if you're only doing exact searches if + + + align:start position:0% +if you're only doing exact searches if +you want to find a key + + align:start position:0% +you want to find a key + + + align:start position:0% +you want to find a key +and get yes or no is it in there and if + + align:start position:0% +and get yes or no is it in there and if + + + align:start position:0% +and get yes or no is it in there and if +it's in there give me the item + + align:start position:0% +it's in there give me the item + + + align:start position:0% +it's in there give me the item +that's what python dictionaries do and + + align:start position:0% +that's what python dictionaries do and + + + align:start position:0% +that's what python dictionaries do and +they're + + align:start position:0% +they're + + + align:start position:0% +they're +great at inserting and deleting but + + align:start position:0% +great at inserting and deleting but + + + align:start position:0% +great at inserting and deleting but +they're really bad + + align:start position:0% +they're really bad + + + align:start position:0% +they're really bad +at find previous and find next this is a + + align:start position:0% +at find previous and find next this is a + + + align:start position:0% +at find previous and find next this is a +the unsuccessful case if i search for a + + align:start position:0% +the unsuccessful case if i search for a + + + align:start position:0% +the unsuccessful case if i search for a +key and it's not in my structure + + align:start position:0% +key and it's not in my structure + + + align:start position:0% +key and it's not in my structure +i would like to know more than just the + + align:start position:0% +i would like to know more than just the + + + align:start position:0% +i would like to know more than just the +answer no i'd like to know what the + + align:start position:0% +answer no i'd like to know what the + + + align:start position:0% +answer no i'd like to know what the +previous and next items that are + + align:start position:0% +previous and next items that are + + + align:start position:0% +previous and next items that are +actually in the structure + + align:start position:0% +actually in the structure + + + align:start position:0% +actually in the structure +so what are my nearest matches when i + + align:start position:0% +so what are my nearest matches when i + + + align:start position:0% +so what are my nearest matches when i +search by key that's a natural query + + align:start position:0% +search by key that's a natural query + + + align:start position:0% +search by key that's a natural query +and the only data structure we have + + align:start position:0% +and the only data structure we have + + + align:start position:0% +and the only data structure we have +that's good at it is a sorted array + + align:start position:0% +that's good at it is a sorted array + + + align:start position:0% +that's good at it is a sorted array +because binary search gives this to us + + align:start position:0% +because binary search gives this to us + + + align:start position:0% +because binary search gives this to us +if we search for a key by binary search + + align:start position:0% +if we search for a key by binary search + + + align:start position:0% +if we search for a key by binary search +and we don't find it + + align:start position:0% +and we don't find it + + + align:start position:0% +and we don't find it +the position that we end up at is right + + align:start position:0% +the position that we end up at is right + + + align:start position:0% +the position that we end up at is right +between the previous and next one + + align:start position:0% +between the previous and next one + + + align:start position:0% +between the previous and next one +but of course sorted arrays are terrible + + align:start position:0% +but of course sorted arrays are terrible + + + align:start position:0% +but of course sorted arrays are terrible +for dynamic + + align:start position:0% +for dynamic + + + align:start position:0% +for dynamic +operations we don't know how to maintain + + align:start position:0% +operations we don't know how to maintain + + + align:start position:0% +operations we don't know how to maintain +we can't maintain a sorted array without + + align:start position:0% +we can't maintain a sorted array without + + + align:start position:0% +we can't maintain a sorted array without +any gaps + + align:start position:0% +any gaps + + + align:start position:0% +any gaps +when we're doing insertions and + + align:start position:0% +when we're doing insertions and + + + align:start position:0% +when we're doing insertions and +deletions in some sense today + + align:start position:0% +deletions in some sense today + + + align:start position:0% +deletions in some sense today +and next class binary trees let us + + align:start position:0% +and next class binary trees let us + + + align:start position:0% +and next class binary trees let us +represent + + align:start position:0% +represent + + + align:start position:0% +represent +a sorted order or in general an order of + + align:start position:0% +a sorted order or in general an order of + + + align:start position:0% +a sorted order or in general an order of +items + + align:start position:0% +items + + + align:start position:0% +items +dynamically and still allow us to do + + align:start position:0% +dynamically and still allow us to do + + + align:start position:0% +dynamically and still allow us to do +very fast things like get out of i and + + align:start position:0% +very fast things like get out of i and + + + align:start position:0% +very fast things like get out of i and +find previous of the key + + align:start position:0% +find previous of the key + + + align:start position:0% +find previous of the key +so that's our goal we're not going to + + align:start position:0% +so that's our goal we're not going to + + + align:start position:0% +so that's our goal we're not going to +quite get to this goal today + + align:start position:0% +quite get to this goal today + + + align:start position:0% +quite get to this goal today +we're going to get an incomparable thing + + align:start position:0% +we're going to get an incomparable thing + + + align:start position:0% +we're going to get an incomparable thing +called the height of the tree and then + + align:start position:0% +called the height of the tree and then + + + align:start position:0% +called the height of the tree and then +on thursday we'll be able to finish and + + align:start position:0% +on thursday we'll be able to finish and + + + align:start position:0% +on thursday we'll be able to finish and +achieve this goal today is just + + align:start position:0% +achieve this goal today is just + + + align:start position:0% +achieve this goal today is just +in service to that goal + + align:start position:0% + + + + align:start position:0% + +so what is a binary tree + + align:start position:0% +so what is a binary tree + + + align:start position:0% +so what is a binary tree +let me draw an example + + align:start position:0% +let me draw an example + + + align:start position:0% +let me draw an example +and then define it more precisely + + align:start position:0% +and then define it more precisely + + + align:start position:0% +and then define it more precisely +mathematicians will call this a rooted + + align:start position:0% +mathematicians will call this a rooted + + + align:start position:0% +mathematicians will call this a rooted +binary tree + + align:start position:0% +binary tree + + + align:start position:0% +binary tree +because in case you've seen that in o42 + + align:start position:0% +because in case you've seen that in o42 + + + align:start position:0% +because in case you've seen that in o42 +say + + align:start position:0% + + + + align:start position:0% + +here is a picture + + align:start position:0% + + + + align:start position:0% + +so this is an example of a binary tree + + align:start position:0% +so this is an example of a binary tree + + + align:start position:0% +so this is an example of a binary tree +it has a bunch of nodes which we're + + align:start position:0% +it has a bunch of nodes which we're + + + align:start position:0% +it has a bunch of nodes which we're +drawing in circles it has + + align:start position:0% +drawing in circles it has + + + align:start position:0% +drawing in circles it has +items in the nodes which were i'm + + align:start position:0% +items in the nodes which were i'm + + + align:start position:0% +items in the nodes which were i'm +writing as letters here + + align:start position:0% +writing as letters here + + + align:start position:0% +writing as letters here +so this is item a item b item c and it + + align:start position:0% +so this is item a item b item c and it + + + align:start position:0% +so this is item a item b item c and it +has these + + align:start position:0% +has these + + + align:start position:0% +has these +links between them this is like linked + + align:start position:0% +links between them this is like linked + + + align:start position:0% +links between them this is like linked +lists + + align:start position:0% +lists + + + align:start position:0% +lists +but in general a node + + align:start position:0% +but in general a node + + + align:start position:0% +but in general a node +x is going to have a parent pointer + + align:start position:0% + + + + align:start position:0% + +a left child + + align:start position:0% +a left child + + + align:start position:0% +a left child +left pointer and a right child + + align:start position:0% +left pointer and a right child + + + align:start position:0% +left pointer and a right child +right pointer and it also has + + align:start position:0% +right pointer and it also has + + + align:start position:0% +right pointer and it also has +an item inside of it so i'm going to + + align:start position:0% +an item inside of it so i'm going to + + + align:start position:0% +an item inside of it so i'm going to +talk about node.left + + align:start position:0% +talk about node.left + + + align:start position:0% +talk about node.left +is a pointer to the left + + align:start position:0% +is a pointer to the left + + + align:start position:0% +is a pointer to the left +the node down here node.right + + align:start position:0% +the node down here node.right + + + align:start position:0% +the node down here node.right +node.parent node.item + + align:start position:0% +node.parent node.item + + + align:start position:0% +node.parent node.item +gives me so if i + + align:start position:0% +gives me so if i + + + align:start position:0% +gives me so if i +look at the node a its item is + + align:start position:0% +look at the node a its item is + + + align:start position:0% +look at the node a its item is +a so let me draw for you + + align:start position:0% + + + + align:start position:0% + +some examples + + align:start position:0% +some examples + + + align:start position:0% +some examples +okay the parent of a is nothing so we + + align:start position:0% +okay the parent of a is nothing so we + + + align:start position:0% +okay the parent of a is nothing so we +call a + + align:start position:0% +call a + + + align:start position:0% +call a +the root node there's going to be a + + align:start position:0% +the root node there's going to be a + + + align:start position:0% +the root node there's going to be a +unique node that has no parent + + align:start position:0% +unique node that has no parent + + + align:start position:0% +unique node that has no parent +it's uh sad to have no parents but there + + align:start position:0% +it's uh sad to have no parents but there + + + align:start position:0% +it's uh sad to have no parents but there +you go + + align:start position:0% +you go + + + align:start position:0% +you go +then we have node b which whose parent + + align:start position:0% +then we have node b which whose parent + + + align:start position:0% +then we have node b which whose parent +is a + + align:start position:0% +is a + + + align:start position:0% +is a +node c is parent its apparent is a node + + align:start position:0% +node c is parent its apparent is a node + + + align:start position:0% +node c is parent its apparent is a node +d its parent is b + + align:start position:0% +d its parent is b + + + align:start position:0% +d its parent is b +node e its parent is b and node f its + + align:start position:0% +node e its parent is b and node f its + + + align:start position:0% +node e its parent is b and node f its +parent is d + + align:start position:0% +parent is d + + + align:start position:0% +parent is d +alphabetical order here happens to be + + align:start position:0% +alphabetical order here happens to be + + + align:start position:0% +alphabetical order here happens to be +ordered by parent + + align:start position:0% + + + + align:start position:0% + +then we have left pointers i'll just do + + align:start position:0% +then we have left pointers i'll just do + + + align:start position:0% +then we have left pointers i'll just do +a few of them so left pointer of + + align:start position:0% +a few of them so left pointer of + + + align:start position:0% +a few of them so left pointer of +a is b right pointer of a + + align:start position:0% +a is b right pointer of a + + + align:start position:0% +a is b right pointer of a +sorry b the node uh these should all be + + align:start position:0% +sorry b the node uh these should all be + + + align:start position:0% +sorry b the node uh these should all be +notes + + align:start position:0% + + + + align:start position:0% + +i'm circling for nodes and just writing + + align:start position:0% +i'm circling for nodes and just writing + + + align:start position:0% +i'm circling for nodes and just writing +the letter for the item + + align:start position:0% +the letter for the item + + + align:start position:0% +the letter for the item +make it clear that those are different + + align:start position:0% +make it clear that those are different + + + align:start position:0% +make it clear that those are different +things uh the right pointer for a + + align:start position:0% +things uh the right pointer for a + + + align:start position:0% +things uh the right pointer for a +is c left pointer for b is d + + align:start position:0% +is c left pointer for b is d + + + align:start position:0% +is c left pointer for b is d +right pointer for b is e and so on + + align:start position:0% +right pointer for b is e and so on + + + align:start position:0% +right pointer for b is e and so on +okay so in other words each of these + + align:start position:0% +okay so in other words each of these + + + align:start position:0% +okay so in other words each of these +lines is a bi-directional pointer + + align:start position:0% +lines is a bi-directional pointer + + + align:start position:0% +lines is a bi-directional pointer +uh in this direction it's the parent + + align:start position:0% +uh in this direction it's the parent + + + align:start position:0% +uh in this direction it's the parent +direction in this direction it's left in + + align:start position:0% +direction in this direction it's left in + + + align:start position:0% +direction in this direction it's left in +this case + + align:start position:0% +this case + + + align:start position:0% +this case +because it's bidirectional we don't draw + + align:start position:0% +because it's bidirectional we don't draw + + + align:start position:0% +because it's bidirectional we don't draw +the arrows we just draw + + align:start position:0% +the arrows we just draw + + + align:start position:0% +the arrows we just draw +undirected lines okay + + align:start position:0% +undirected lines okay + + + align:start position:0% +undirected lines okay +this is in general what a binary tree + + align:start position:0% +this is in general what a binary tree + + + align:start position:0% +this is in general what a binary tree +looks like + + align:start position:0% +looks like + + + align:start position:0% +looks like +a key invariant is that if you take a + + align:start position:0% +a key invariant is that if you take a + + + align:start position:0% +a key invariant is that if you take a +node + + align:start position:0% +node + + + align:start position:0% +node +and say go to its left pointer left + + align:start position:0% +and say go to its left pointer left + + + align:start position:0% +and say go to its left pointer left +child and then go to that node's parent + + align:start position:0% +child and then go to that node's parent + + + align:start position:0% +child and then go to that node's parent +this should be the same as node right so + + align:start position:0% +this should be the same as node right so + + + align:start position:0% +this should be the same as node right so +that's just saying these + + align:start position:0% +that's just saying these + + + align:start position:0% +that's just saying these +are in parent is always the inverse of a + + align:start position:0% +are in parent is always the inverse of a + + + align:start position:0% +are in parent is always the inverse of a +left or right operation + + align:start position:0% +left or right operation + + + align:start position:0% +left or right operation +this is also true for write + + align:start position:0% + + + + align:start position:0% + +okay and that's a binary tree now the + + align:start position:0% +okay and that's a binary tree now the + + + align:start position:0% +okay and that's a binary tree now the +intuition of what's going on here + + align:start position:0% +intuition of what's going on here + + + align:start position:0% +intuition of what's going on here +is you could you could say it's we're + + align:start position:0% +is you could you could say it's we're + + + align:start position:0% +is you could you could say it's we're +inspired by + + align:start position:0% +inspired by + + + align:start position:0% +inspired by +a linked list linked list had a very + + align:start position:0% +a linked list linked list had a very + + + align:start position:0% +a linked list linked list had a very +similar structure + + align:start position:0% +similar structure + + + align:start position:0% +similar structure +maybe an item or there's a node it had + + align:start position:0% +maybe an item or there's a node it had + + + align:start position:0% +maybe an item or there's a node it had +an item in it + + align:start position:0% +an item in it + + + align:start position:0% +an item in it +and it had a next pointer and it had a + + align:start position:0% +and it had a next pointer and it had a + + + align:start position:0% +and it had a next pointer and it had a +previous pointer + + align:start position:0% +previous pointer + + + align:start position:0% +previous pointer +so in some sense what we're if it's + + align:start position:0% +so in some sense what we're if it's + + + align:start position:0% +so in some sense what we're if it's +doubly linked we had a previous pointer + + align:start position:0% +doubly linked we had a previous pointer + + + align:start position:0% +doubly linked we had a previous pointer +it was singly linked we only had a next + + align:start position:0% +it was singly linked we only had a next + + + align:start position:0% +it was singly linked we only had a next +pointer + + align:start position:0% +pointer + + + align:start position:0% +pointer +and if you think about the limits of + + align:start position:0% +and if you think about the limits of + + + align:start position:0% +and if you think about the limits of +linked lists especially singly linked + + align:start position:0% +linked lists especially singly linked + + + align:start position:0% +linked lists especially singly linked +lists + + align:start position:0% +lists + + + align:start position:0% +lists +if you just have one pointer per node + + align:start position:0% +if you just have one pointer per node + + + align:start position:0% +if you just have one pointer per node +you can only build a list + + align:start position:0% +you can only build a list + + + align:start position:0% +you can only build a list +and so the result is uh + + align:start position:0% + + + + align:start position:0% + +you know this this node is going to have + + align:start position:0% +you know this this node is going to have + + + align:start position:0% +you know this this node is going to have +depth linear depth means how many + + align:start position:0% +depth linear depth means how many + + + align:start position:0% +depth linear depth means how many +pointers do i have to follow to get here + + align:start position:0% +pointers do i have to follow to get here + + + align:start position:0% +pointers do i have to follow to get here +from the root of the structure which for + + align:start position:0% +from the root of the structure which for + + + align:start position:0% +from the root of the structure which for +linked lists was the head + + align:start position:0% +linked lists was the head + + + align:start position:0% +linked lists was the head +it was doubly linked okay i can have a + + align:start position:0% +it was doubly linked okay i can have a + + + align:start position:0% +it was doubly linked okay i can have a +head and a tail and i can put + + align:start position:0% +head and a tail and i can put + + + align:start position:0% +head and a tail and i can put +bi-directions + + align:start position:0% +bi-directions + + + align:start position:0% +bi-directions +on here but then still the middle item + + align:start position:0% +on here but then still the middle item + + + align:start position:0% +on here but then still the middle item +has depth linear so there's no way to + + align:start position:0% +has depth linear so there's no way to + + + align:start position:0% +has depth linear so there's no way to +get there + + align:start position:0% +get there + + + align:start position:0% +get there +in less than linear time with binary + + align:start position:0% +in less than linear time with binary + + + align:start position:0% +in less than linear time with binary +trees because we use + + align:start position:0% +trees because we use + + + align:start position:0% +trees because we use +two types of next pointers left and + + align:start position:0% +two types of next pointers left and + + + align:start position:0% +two types of next pointers left and +right + + align:start position:0% +right + + + align:start position:0% +right +we can build a tree and we know trees in + + align:start position:0% +we can build a tree and we know trees in + + + align:start position:0% +we can build a tree and we know trees in +general have logarithmic + + align:start position:0% +general have logarithmic + + + align:start position:0% +general have logarithmic +can have logarithmic height + + align:start position:0% +can have logarithmic height + + + align:start position:0% +can have logarithmic height +and so it's possible in a tree to get to + + align:start position:0% +and so it's possible in a tree to get to + + + align:start position:0% +and so it's possible in a tree to get to +any node starting from the root in only + + align:start position:0% +any node starting from the root in only + + + align:start position:0% +any node starting from the root in only +log n traversals so that's the intuition + + align:start position:0% +log n traversals so that's the intuition + + + align:start position:0% +log n traversals so that's the intuition +of what's going on + + align:start position:0% +of what's going on + + + align:start position:0% +of what's going on +now today + + align:start position:0% + + + + align:start position:0% + +we're going to talk about the height of + + align:start position:0% +we're going to talk about the height of + + + align:start position:0% +we're going to talk about the height of +a tree + + align:start position:0% +a tree + + + align:start position:0% +a tree +so let me define + + align:start position:0% + + + + align:start position:0% + +i'm going to need a couple definitions + + align:start position:0% +i'm going to need a couple definitions + + + align:start position:0% +i'm going to need a couple definitions +here + + align:start position:0% + + + + align:start position:0% + +subtree and height + + align:start position:0% +subtree and height + + + align:start position:0% +subtree and height +of a node uh + + align:start position:0% +of a node uh + + + align:start position:0% +of a node uh +so a tree decomposes into sub trees + + align:start position:0% +so a tree decomposes into sub trees + + + align:start position:0% +so a tree decomposes into sub trees +so for example the subtree rooted at b + + align:start position:0% +so for example the subtree rooted at b + + + align:start position:0% +so for example the subtree rooted at b +or the subtree of b + + align:start position:0% +or the subtree of b + + + align:start position:0% +or the subtree of b +is this portion of the tree + + align:start position:0% + + + + align:start position:0% + +so it's that node and all of the + + align:start position:0% +so it's that node and all of the + + + align:start position:0% +so it's that node and all of the +descendants of this node so because we + + align:start position:0% +descendants of this node so because we + + + align:start position:0% +descendants of this node so because we +have parents and children + + align:start position:0% +have parents and children + + + align:start position:0% +have parents and children +we can generalize in the familial tree + + align:start position:0% +we can generalize in the familial tree + + + align:start position:0% +we can generalize in the familial tree +sense + + align:start position:0% +sense + + + align:start position:0% +sense +we can talk about ancestors of a node so + + align:start position:0% +we can talk about ancestors of a node so + + + align:start position:0% +we can talk about ancestors of a node so +the ancestors of f + + align:start position:0% +the ancestors of f + + + align:start position:0% +the ancestors of f +are its parent its grandparents its + + align:start position:0% +are its parent its grandparents its + + + align:start position:0% +are its parent its grandparents its +great grandparents and so on + + align:start position:0% +great grandparents and so on + + + align:start position:0% +great grandparents and so on +together all of these are called + + align:start position:0% +together all of these are called + + + align:start position:0% +together all of these are called +ancestors + + align:start position:0% +ancestors + + + align:start position:0% +ancestors +it's a it doesn't quite correspond to + + align:start position:0% +it's a it doesn't quite correspond to + + + align:start position:0% +it's a it doesn't quite correspond to +familiar trees because familial trees + + align:start position:0% +familiar trees because familial trees + + + align:start position:0% +familiar trees because familial trees +you have + + align:start position:0% +you have + + + align:start position:0% +you have +two parents here you only have a unique + + align:start position:0% +two parents here you only have a unique + + + align:start position:0% +two parents here you only have a unique +parent + + align:start position:0% +parent + + + align:start position:0% +parent +or the poor root has no parent + + align:start position:0% +or the poor root has no parent + + + align:start position:0% +or the poor root has no parent +we also talk about it's like mixed + + align:start position:0% +we also talk about it's like mixed + + + align:start position:0% +we also talk about it's like mixed +metaphors + + align:start position:0% +metaphors + + + align:start position:0% +metaphors +leaves of the tree + + align:start position:0% +leaves of the tree + + + align:start position:0% +leaves of the tree +these are + + align:start position:0% + + + + align:start position:0% + +people with no children parents will + + align:start position:0% +people with no children parents will + + + align:start position:0% +people with no children parents will +complain about this + + align:start position:0% +complain about this + + + align:start position:0% +complain about this +but many like many of us in this room we + + align:start position:0% +but many like many of us in this room we + + + align:start position:0% +but many like many of us in this room we +have no children yet so we were called + + align:start position:0% +have no children yet so we were called + + + align:start position:0% +have no children yet so we were called +leaves + + align:start position:0% +leaves + + + align:start position:0% +leaves +you can tell your parents hey i'm just a + + align:start position:0% +you can tell your parents hey i'm just a + + + align:start position:0% +you can tell your parents hey i'm just a +leaf you know blowing in the wind + + align:start position:0% +leaf you know blowing in the wind + + + align:start position:0% +leaf you know blowing in the wind +so uh you know like this it's so many + + align:start position:0% +so uh you know like this it's so many + + + align:start position:0% +so uh you know like this it's so many +mixed metaphors but we + + align:start position:0% +mixed metaphors but we + + + align:start position:0% +mixed metaphors but we +always draw trees downwards like the + + align:start position:0% +always draw trees downwards like the + + + align:start position:0% +always draw trees downwards like the +root structure of a tree + + align:start position:0% +root structure of a tree + + + align:start position:0% +root structure of a tree +yet we call the ends of the roots leaves + + align:start position:0% +yet we call the ends of the roots leaves + + + align:start position:0% +yet we call the ends of the roots leaves +which is upside down + + align:start position:0% +which is upside down + + + align:start position:0% +which is upside down +anyway that's trees for you lots of + + align:start position:0% +anyway that's trees for you lots of + + + align:start position:0% +anyway that's trees for you lots of +entertaining analogies okay but + + align:start position:0% +entertaining analogies okay but + + + align:start position:0% +entertaining analogies okay but +ancestors are useful descendants are + + align:start position:0% +ancestors are useful descendants are + + + align:start position:0% +ancestors are useful descendants are +also useful + + align:start position:0% +also useful + + + align:start position:0% +also useful +so the descendants of b are all of its + + align:start position:0% +so the descendants of b are all of its + + + align:start position:0% +so the descendants of b are all of its +children and all of its grandchildren + + align:start position:0% +children and all of its grandchildren + + + align:start position:0% +children and all of its grandchildren +and all the way down + + align:start position:0% +and all the way down + + + align:start position:0% +and all the way down +but just within the subtree so subtree + + align:start position:0% +but just within the subtree so subtree + + + align:start position:0% +but just within the subtree so subtree +of x + + align:start position:0% +of x + + + align:start position:0% +of x +consists of x and its descendants + + align:start position:0% + + + + align:start position:0% + +and we think of x being the root + + align:start position:0% +and we think of x being the root + + + align:start position:0% +and we think of x being the root +of that subtree so we're kind of + + align:start position:0% +of that subtree so we're kind of + + + align:start position:0% +of that subtree so we're kind of +forgetting about everything outside of + + align:start position:0% +forgetting about everything outside of + + + align:start position:0% +forgetting about everything outside of +the sub tree + + align:start position:0% +the sub tree + + + align:start position:0% +the sub tree +when we talk about sub tree of x let's + + align:start position:0% +when we talk about sub tree of x let's + + + align:start position:0% +when we talk about sub tree of x let's +talk about the + + align:start position:0% +talk about the + + + align:start position:0% +talk about the +depth of a node + + align:start position:0% + + + + align:start position:0% + +depth of the node is + + align:start position:0% + + + + align:start position:0% + +i guess the number of its ancestors + + align:start position:0% +i guess the number of its ancestors + + + align:start position:0% +i guess the number of its ancestors +right um but way i usually think of it + + align:start position:0% +right um but way i usually think of it + + + align:start position:0% +right um but way i usually think of it +is + + align:start position:0% +is + + + align:start position:0% +is +the number of number of edges + + align:start position:0% + + + + align:start position:0% + +and in the path from + + align:start position:0% +and in the path from + + + align:start position:0% +and in the path from +x up to the root + + align:start position:0% + + + + align:start position:0% + +so every node has a unique path that + + align:start position:0% +so every node has a unique path that + + + align:start position:0% +so every node has a unique path that +goes upwards + + align:start position:0% +goes upwards + + + align:start position:0% +goes upwards +until it can't go up anymore so the + + align:start position:0% +until it can't go up anymore so the + + + align:start position:0% +until it can't go up anymore so the +depth of e + + align:start position:0% +depth of e + + + align:start position:0% +depth of e +is two because there are two edges uh + + align:start position:0% +is two because there are two edges uh + + + align:start position:0% +is two because there are two edges uh +one two in the path from the root a to e + + align:start position:0% +one two in the path from the root a to e + + + align:start position:0% +one two in the path from the root a to e +so maybe i'll write some depths uh depth + + align:start position:0% +so maybe i'll write some depths uh depth + + + align:start position:0% +so maybe i'll write some depths uh depth +of e is two + + align:start position:0% +of e is two + + + align:start position:0% +of e is two +depth of these guys is one depth of the + + align:start position:0% +depth of these guys is one depth of the + + + align:start position:0% +depth of these guys is one depth of the +root is zero + + align:start position:0% +root is zero + + + align:start position:0% +root is zero +two three so those are + + align:start position:0% +two three so those are + + + align:start position:0% +two three so those are +depth i'm going to + + align:start position:0% +depth i'm going to + + + align:start position:0% +depth i'm going to +clean this up a little bit + + align:start position:0% +clean this up a little bit + + + align:start position:0% +clean this up a little bit +so we can focus on the image all right + + align:start position:0% +so we can focus on the image all right + + + align:start position:0% +so we can focus on the image all right +height so depth is measuring + + align:start position:0% +height so depth is measuring + + + align:start position:0% +height so depth is measuring +downwards because we you know if you + + align:start position:0% +downwards because we you know if you + + + align:start position:0% +downwards because we you know if you +imagine depth within water + + align:start position:0% +imagine depth within water + + + align:start position:0% +imagine depth within water +this is uh the surface of the water and + + align:start position:0% +this is uh the surface of the water and + + + align:start position:0% +this is uh the surface of the water and +then we measure how deep you are from + + align:start position:0% +then we measure how deep you are from + + + align:start position:0% +then we measure how deep you are from +the surface + + align:start position:0% +the surface + + + align:start position:0% +the surface +height is in the reverse direction we're + + align:start position:0% +height is in the reverse direction we're + + + align:start position:0% +height is in the reverse direction we're +going to measure from the leaf level + + align:start position:0% +going to measure from the leaf level + + + align:start position:0% +going to measure from the leaf level +up because leaves are the bottom of the + + align:start position:0% +up because leaves are the bottom of the + + + align:start position:0% +up because leaves are the bottom of the +tree so height + + align:start position:0% +tree so height + + + align:start position:0% +tree so height +of a node is going to be + + align:start position:0% +of a node is going to be + + + align:start position:0% +of a node is going to be +the number of edges + + align:start position:0% +the number of edges + + + align:start position:0% +the number of edges +in the longest downward path + + align:start position:0% + + + + align:start position:0% + +okay which is the same thing as the + + align:start position:0% +okay which is the same thing as the + + + align:start position:0% +okay which is the same thing as the +maximum depth of a node + + align:start position:0% +maximum depth of a node + + + align:start position:0% +maximum depth of a node +in x's subtree + + align:start position:0% + + + + align:start position:0% + +let's do height in red + + align:start position:0% +let's do height in red + + + align:start position:0% +let's do height in red +so uh how long is the longest path from + + align:start position:0% +so uh how long is the longest path from + + + align:start position:0% +so uh how long is the longest path from +f to a leaf well f is a leaf so all + + align:start position:0% +f to a leaf well f is a leaf so all + + + align:start position:0% +f to a leaf well f is a leaf so all +leaves have + + align:start position:0% +leaves have + + + align:start position:0% +leaves have +depth zero sorry height zero + + align:start position:0% +depth zero sorry height zero + + + align:start position:0% +depth zero sorry height zero +get it backwards um + + align:start position:0% +get it backwards um + + + align:start position:0% +get it backwards um +d here it's so there are two + + align:start position:0% +d here it's so there are two + + + align:start position:0% +d here it's so there are two +ways to go down this doesn't go to a + + align:start position:0% +ways to go down this doesn't go to a + + + align:start position:0% +ways to go down this doesn't go to a +leaf uh this one goes to a leaf + + align:start position:0% +leaf uh this one goes to a leaf + + + align:start position:0% +leaf uh this one goes to a leaf +and its height is zero so this height is + + align:start position:0% +and its height is zero so this height is + + + align:start position:0% +and its height is zero so this height is +one there's one edge to a leaf here b + + align:start position:0% +one there's one edge to a leaf here b + + + align:start position:0% +one there's one edge to a leaf here b +has two leaves it can get to we take the + + align:start position:0% +has two leaves it can get to we take the + + + align:start position:0% +has two leaves it can get to we take the +longest one so that's length two + + align:start position:0% +longest one so that's length two + + + align:start position:0% +longest one so that's length two +a similarly has height three + + align:start position:0% +a similarly has height three + + + align:start position:0% +a similarly has height three +okay so height we measure upward depth + + align:start position:0% +okay so height we measure upward depth + + + align:start position:0% +okay so height we measure upward depth +we measure + + align:start position:0% +we measure + + + align:start position:0% +we measure +downward well one thing we care about uh + + align:start position:0% +downward well one thing we care about uh + + + align:start position:0% +downward well one thing we care about uh +is just the height + + align:start position:0% +is just the height + + + align:start position:0% +is just the height +of the overall tree uh which + + align:start position:0% +of the overall tree uh which + + + align:start position:0% +of the overall tree uh which +is the height of the root + + align:start position:0% + + + + align:start position:0% + +and i'm going to call that h because + + align:start position:0% +and i'm going to call that h because + + + align:start position:0% +and i'm going to call that h because +we're going to use it a lot + + align:start position:0% + + + + align:start position:0% + +and what we're going to achieve today is + + align:start position:0% +and what we're going to achieve today is + + + align:start position:0% +and what we're going to achieve today is +all of these running times instead of + + align:start position:0% +all of these running times instead of + + + align:start position:0% +all of these running times instead of +being log n + + align:start position:0% +being log n + + + align:start position:0% +being log n +they're going to be order h + + align:start position:0% + + + + align:start position:0% + +so today our goal is to get all the + + align:start position:0% +so today our goal is to get all the + + + align:start position:0% +so today our goal is to get all the +operations we care about + + align:start position:0% +operations we care about + + + align:start position:0% +operations we care about +in order h type + + align:start position:0% + + + + align:start position:0% + +and then next lecture we're going to + + align:start position:0% +and then next lecture we're going to + + + align:start position:0% +and then next lecture we're going to +guarantee that h is always log n + + align:start position:0% +guarantee that h is always log n + + + align:start position:0% +guarantee that h is always log n +and then we'll get log n time so we need + + align:start position:0% +and then we'll get log n time so we need + + + align:start position:0% +and then we'll get log n time so we need +to do a bunch of work to achieve log n + + align:start position:0% +to do a bunch of work to achieve log n + + + align:start position:0% +to do a bunch of work to achieve log n +today we'll do the work that's all the + + align:start position:0% +today we'll do the work that's all the + + + align:start position:0% +today we'll do the work that's all the +tree manipulation + + align:start position:0% +tree manipulation + + + align:start position:0% +tree manipulation +and as long as your tree is nice and + + align:start position:0% +and as long as your tree is nice and + + + align:start position:0% +and as long as your tree is nice and +shallow it doesn't have high height + + align:start position:0% +shallow it doesn't have high height + + + align:start position:0% +shallow it doesn't have high height +if it has logarithmic height everything + + align:start position:0% +if it has logarithmic height everything + + + align:start position:0% +if it has logarithmic height everything +will be log n of course there are trees + + align:start position:0% +will be log n of course there are trees + + + align:start position:0% +will be log n of course there are trees +that are really bad + + align:start position:0% +that are really bad + + + align:start position:0% +that are really bad +right we can have a tree + + align:start position:0% + + + + align:start position:0% + +a tree like this which is basically a + + align:start position:0% +a tree like this which is basically a + + + align:start position:0% +a tree like this which is basically a +linked list + + align:start position:0% +linked list + + + align:start position:0% +linked list +where we only use right pointers and all + + align:start position:0% +where we only use right pointers and all + + + align:start position:0% +where we only use right pointers and all +the left pointers are none + + align:start position:0% +the left pointers are none + + + align:start position:0% +the left pointers are none +so there are height there are trees that + + align:start position:0% +so there are height there are trees that + + + align:start position:0% +so there are height there are trees that +are very high + + align:start position:0% +are very high + + + align:start position:0% +are very high +have high height um we want to avoid + + align:start position:0% +have high height um we want to avoid + + + align:start position:0% +have high height um we want to avoid +these but we won't worry about that till + + align:start position:0% +these but we won't worry about that till + + + align:start position:0% +these but we won't worry about that till +next lecture question + + align:start position:0% + + + + align:start position:0% + +what is the height of node c height of + + align:start position:0% +what is the height of node c height of + + + align:start position:0% +what is the height of node c height of +node c is zero + + align:start position:0% +node c is zero + + + align:start position:0% +node c is zero +because the length of the longest path + + align:start position:0% +because the length of the longest path + + + align:start position:0% +because the length of the longest path +the number of edges in the longest + + align:start position:0% +the number of edges in the longest + + + align:start position:0% +the number of edges in the longest +downward path is zero yeah we're + + align:start position:0% +downward path is zero yeah we're + + + align:start position:0% +downward path is zero yeah we're +counting edges not vertices + + align:start position:0% + + + + align:start position:0% + +uh yeah so the height of the tree is of + + align:start position:0% +uh yeah so the height of the tree is of + + + align:start position:0% +uh yeah so the height of the tree is of +course just the depth + + align:start position:0% +course just the depth + + + align:start position:0% +course just the depth +the maximum depth i think that's right + + align:start position:0% +the maximum depth i think that's right + + + align:start position:0% +the maximum depth i think that's right +so the height here is + + align:start position:0% +so the height here is + + + align:start position:0% +so the height here is +three and the maximum depth is this + + align:start position:0% +three and the maximum depth is this + + + align:start position:0% +three and the maximum depth is this +terribly drawn three + + align:start position:0% +terribly drawn three + + + align:start position:0% +terribly drawn three +so these happen to correspond in the + + align:start position:0% +so these happen to correspond in the + + + align:start position:0% +so these happen to correspond in the +maximum case + + align:start position:0% +maximum case + + + align:start position:0% +maximum case +but we use height to always mean maximum + + align:start position:0% +but we use height to always mean maximum + + + align:start position:0% +but we use height to always mean maximum +and so that's why + + align:start position:0% +and so that's why + + + align:start position:0% +and so that's why +we talk about the height of the tree + + align:start position:0% +we talk about the height of the tree + + + align:start position:0% +we talk about the height of the tree +depth of the tree is not defined + + align:start position:0% +depth of the tree is not defined + + + align:start position:0% +depth of the tree is not defined +just depths of notes okay + + align:start position:0% +just depths of notes okay + + + align:start position:0% +just depths of notes okay +um how do we use these trees to + + align:start position:0% +um how do we use these trees to + + + align:start position:0% +um how do we use these trees to +represent + + align:start position:0% +represent + + + align:start position:0% +represent +either a sequence or a set uh + + align:start position:0% +either a sequence or a set uh + + + align:start position:0% +either a sequence or a set uh +i claim that there is a natural order + + align:start position:0% +i claim that there is a natural order + + + align:start position:0% +i claim that there is a natural order +in trees called the traversal order + + align:start position:0% + + + + align:start position:0% + +of nodes or items + + align:start position:0% +of nodes or items + + + align:start position:0% +of nodes or items +and the tree so i'm going to define a + + align:start position:0% +and the tree so i'm going to define a + + + align:start position:0% +and the tree so i'm going to define a +particular order + + align:start position:0% +particular order + + + align:start position:0% +particular order +uh say in this example + + align:start position:0% +uh say in this example + + + align:start position:0% +uh say in this example +let's do the example first the + + align:start position:0% +let's do the example first the + + + align:start position:0% +let's do the example first the +traversal order + + align:start position:0% + + + + align:start position:0% + +is going to be f + + align:start position:0% +is going to be f + + + align:start position:0% +is going to be f +d b + + align:start position:0% + + + + align:start position:0% + +e a + + align:start position:0% +e a + + + align:start position:0% +e a +c i feel like i'm in music class this is + + align:start position:0% +c i feel like i'm in music class this is + + + align:start position:0% +c i feel like i'm in music class this is +my guitar or something but it's not i + + align:start position:0% +my guitar or something but it's not i + + + align:start position:0% +my guitar or something but it's not i +hope um + + align:start position:0% +hope um + + + align:start position:0% +hope um +if it is a coincidence so + + align:start position:0% +if it is a coincidence so + + + align:start position:0% +if it is a coincidence so +what is this order what i'd like to do + + align:start position:0% +what is this order what i'd like to do + + + align:start position:0% +what is this order what i'd like to do +is um + + align:start position:0% +is um + + + align:start position:0% +is um +recursively define an order where the + + align:start position:0% +recursively define an order where the + + + align:start position:0% +recursively define an order where the +root of the tree is somewhere in the + + align:start position:0% +root of the tree is somewhere in the + + + align:start position:0% +root of the tree is somewhere in the +middle + + align:start position:0% +middle + + + align:start position:0% +middle +and everything in the left subtree is + + align:start position:0% +and everything in the left subtree is + + + align:start position:0% +and everything in the left subtree is +left + + align:start position:0% +left + + + align:start position:0% +left +earlier in the order than the root and + + align:start position:0% +earlier in the order than the root and + + + align:start position:0% +earlier in the order than the root and +everything in the right subtree is later + + align:start position:0% +everything in the right subtree is later + + + align:start position:0% +everything in the right subtree is later +so you can see here c comes after a and + + align:start position:0% +so you can see here c comes after a and + + + align:start position:0% +so you can see here c comes after a and +then all the other nodes come before + + align:start position:0% +then all the other nodes come before + + + align:start position:0% +then all the other nodes come before +a and recursively if i look at a node b + + align:start position:0% +a and recursively if i look at a node b + + + align:start position:0% +a and recursively if i look at a node b +this node b which appears over here e is + + align:start position:0% +this node b which appears over here e is + + + align:start position:0% +this node b which appears over here e is +to the right of it + + align:start position:0% +to the right of it + + + align:start position:0% +to the right of it +but it's this is all to the left of a so + + align:start position:0% +but it's this is all to the left of a so + + + align:start position:0% +but it's this is all to the left of a so +e + + align:start position:0% +e + + + align:start position:0% +e +is between b and a would be on the left + + align:start position:0% +is between b and a would be on the left + + + align:start position:0% +is between b and a would be on the left +and then f and d are to the left of that + + align:start position:0% +and then f and d are to the left of that + + + align:start position:0% +and then f and d are to the left of that +and again f comes before d + + align:start position:0% +and again f comes before d + + + align:start position:0% +and again f comes before d +because f is in the left subtree of d + + align:start position:0% +because f is in the left subtree of d + + + align:start position:0% +because f is in the left subtree of d +okay so we say + + align:start position:0% + + + + align:start position:0% + +for every node + + align:start position:0% + + + + align:start position:0% + +the nodes + + align:start position:0% +the nodes + + + align:start position:0% +the nodes +in x dot left are before x + + align:start position:0% + + + + align:start position:0% + +and the nodes in x dot right are come + + align:start position:0% +and the nodes in x dot right are come + + + align:start position:0% +and the nodes in x dot right are come +after x + + align:start position:0% +after x + + + align:start position:0% +after x +and this uniquely defines an order + + align:start position:0% +and this uniquely defines an order + + + align:start position:0% +and this uniquely defines an order +called a traversal order + + align:start position:0% +called a traversal order + + + align:start position:0% +called a traversal order +it's also called the in-order traversal + + align:start position:0% +it's also called the in-order traversal + + + align:start position:0% +it's also called the in-order traversal +order it's called in order because it's + + align:start position:0% +order it's called in order because it's + + + align:start position:0% +order it's called in order because it's +in the traversal order so it's very + + align:start position:0% +in the traversal order so it's very + + + align:start position:0% +in the traversal order so it's very +circular but + + align:start position:0% +circular but + + + align:start position:0% +circular but +you may have seen inorder traversal this + + align:start position:0% +you may have seen inorder traversal this + + + align:start position:0% +you may have seen inorder traversal this +is the same thing + + align:start position:0% +is the same thing + + + align:start position:0% +is the same thing +there's a very simple algorithm for + + align:start position:0% +there's a very simple algorithm for + + + align:start position:0% +there's a very simple algorithm for +computing this + + align:start position:0% +computing this + + + align:start position:0% +computing this +if i want to iterate + + align:start position:0% +if i want to iterate + + + align:start position:0% +if i want to iterate +uh let's call this yeah if i want to + + align:start position:0% +uh let's call this yeah if i want to + + + align:start position:0% +uh let's call this yeah if i want to +iterate + + align:start position:0% +iterate + + + align:start position:0% +iterate +all the nodes within a subtree x rooted + + align:start position:0% +all the nodes within a subtree x rooted + + + align:start position:0% +all the nodes within a subtree x rooted +by x + + align:start position:0% +by x + + + align:start position:0% +by x +i just iterate on all of the + + align:start position:0% +i just iterate on all of the + + + align:start position:0% +i just iterate on all of the +nodes in the left subtree then i output + + align:start position:0% +nodes in the left subtree then i output + + + align:start position:0% +nodes in the left subtree then i output +x itself + + align:start position:0% + + + + align:start position:0% + +then i iterate on all the nodes in the + + align:start position:0% +then i iterate on all the nodes in the + + + align:start position:0% +then i iterate on all the nodes in the +right subtree + + align:start position:0% + + + + align:start position:0% + +okay you may have seen that algorithm + + align:start position:0% +okay you may have seen that algorithm + + + align:start position:0% +okay you may have seen that algorithm +before this is just another way to + + align:start position:0% +before this is just another way to + + + align:start position:0% +before this is just another way to +codify the same thing + + align:start position:0% +codify the same thing + + + align:start position:0% +codify the same thing +the result is all the nodes within a + + align:start position:0% +the result is all the nodes within a + + + align:start position:0% +the result is all the nodes within a +subtree appear continuously with no + + align:start position:0% +subtree appear continuously with no + + + align:start position:0% +subtree appear continuously with no +interruptions + + align:start position:0% +interruptions + + + align:start position:0% +interruptions +and then the parent parent's going to + + align:start position:0% +and then the parent parent's going to + + + align:start position:0% +and then the parent parent's going to +come before after depending on whether + + align:start position:0% +come before after depending on whether + + + align:start position:0% +come before after depending on whether +it's the left or right child + + align:start position:0% + + + + align:start position:0% + +okay so and now it's just a matter of + + align:start position:0% +okay so and now it's just a matter of + + + align:start position:0% +okay so and now it's just a matter of +connecting the dots because we're + + align:start position:0% +connecting the dots because we're + + + align:start position:0% +connecting the dots because we're +representing an order + + align:start position:0% +representing an order + + + align:start position:0% +representing an order +and for sequence that is going to be the + + align:start position:0% +and for sequence that is going to be the + + + align:start position:0% +and for sequence that is going to be the +sequence order if we want to store n + + align:start position:0% +sequence order if we want to store n + + + align:start position:0% +sequence order if we want to store n +items x0 through x1 + + align:start position:0% +items x0 through x1 + + + align:start position:0% +items x0 through x1 +we're going to build some kind of tree + + align:start position:0% +we're going to build some kind of tree + + + align:start position:0% +we're going to build some kind of tree +we're going to put x0 here + + align:start position:0% +we're going to put x0 here + + + align:start position:0% +we're going to put x0 here +x1 here x2 here x3 here x4 here x5 + + align:start position:0% +x1 here x2 here x3 here x4 here x5 + + + align:start position:0% +x1 here x2 here x3 here x4 here x5 +here you can see i'm very used to + + align:start position:0% +here you can see i'm very used to + + + align:start position:0% +here you can see i'm very used to +dealing with traversal orders it takes a + + align:start position:0% +dealing with traversal orders it takes a + + + align:start position:0% +dealing with traversal orders it takes a +little while + + align:start position:0% +little while + + + align:start position:0% +little while +uh you could also see it here we're + + align:start position:0% +uh you could also see it here we're + + + align:start position:0% +uh you could also see it here we're +going to put x1 on this node x2 + + align:start position:0% +going to put x1 on this node x2 + + + align:start position:0% +going to put x1 on this node x2 +sorry x0 here x1 here x2 here and so on + + align:start position:0% +sorry x0 here x1 here x2 here and so on + + + align:start position:0% +sorry x0 here x1 here x2 here and so on +that's the same order that i gave + + align:start position:0% +that's the same order that i gave + + + align:start position:0% +that's the same order that i gave +okay that's for sequences for sets that + + align:start position:0% +okay that's for sequences for sets that + + + align:start position:0% +okay that's for sequences for sets that +order is just going to be the sorted + + align:start position:0% +order is just going to be the sorted + + + align:start position:0% +order is just going to be the sorted +order + + align:start position:0% +order + + + align:start position:0% +order +and we're going to be effectively + + align:start position:0% +and we're going to be effectively + + + align:start position:0% +and we're going to be effectively +representing the sorted order of keys + + align:start position:0% +representing the sorted order of keys + + + align:start position:0% +representing the sorted order of keys +say increasing but before we get to that + + align:start position:0% +say increasing but before we get to that + + + align:start position:0% +say increasing but before we get to that +let's talk about different operations we + + align:start position:0% +let's talk about different operations we + + + align:start position:0% +let's talk about different operations we +can do + + align:start position:0% + + + + align:start position:0% + +just playing around with traversal order + + align:start position:0% + + + + align:start position:0% + +and then we're going to use these to + + align:start position:0% +and then we're going to use these to + + + align:start position:0% +and then we're going to use these to +build the sequence and set operations + + align:start position:0% +build the sequence and set operations + + + align:start position:0% +build the sequence and set operations +that we care about + + align:start position:0% +that we care about + + + align:start position:0% +that we care about +so first operation i'll call + + align:start position:0% +so first operation i'll call + + + align:start position:0% +so first operation i'll call +subtree first seems appropriate that + + align:start position:0% +subtree first seems appropriate that + + + align:start position:0% +subtree first seems appropriate that +it's called first + + align:start position:0% + + + + align:start position:0% + +it's the first one so given a node + + align:start position:0% +it's the first one so given a node + + + align:start position:0% +it's the first one so given a node +which i'll call node uh this defines + + align:start position:0% +which i'll call node uh this defines + + + align:start position:0% +which i'll call node uh this defines +a subtree + + align:start position:0% + + + + align:start position:0% + +which usually we draw subtrees as + + align:start position:0% +which usually we draw subtrees as + + + align:start position:0% +which usually we draw subtrees as +triangles hanging off of the node + + align:start position:0% +triangles hanging off of the node + + + align:start position:0% +triangles hanging off of the node +so here i would write x + + align:start position:0% +so here i would write x + + + align:start position:0% +so here i would write x +and then there's some subtree of all the + + align:start position:0% +and then there's some subtree of all the + + + align:start position:0% +and then there's some subtree of all the +descendants of x + + align:start position:0% +descendants of x + + + align:start position:0% +descendants of x +so with subtree first i would like to + + align:start position:0% +so with subtree first i would like to + + + align:start position:0% +so with subtree first i would like to +say among + + align:start position:0% +say among + + + align:start position:0% +say among +all the nodes in this subtree + + align:start position:0% + + + + align:start position:0% + +which comes first in traversal order + + align:start position:0% + + + + align:start position:0% + +so just restricting to + + align:start position:0% + + + + align:start position:0% + +that subtree so tree of that + + align:start position:0% + + + + align:start position:0% + +so where is it in this tree + + align:start position:0% + + + + align:start position:0% + +uh note is actually part of many sub + + align:start position:0% +uh note is actually part of many sub + + + align:start position:0% +uh note is actually part of many sub +trees good question uh + + align:start position:0% +trees good question uh + + + align:start position:0% +trees good question uh +f f is in its own in the sub tree of f + + align:start position:0% +f f is in its own in the sub tree of f + + + align:start position:0% +f f is in its own in the sub tree of f +uh + + align:start position:0% +uh + + + align:start position:0% +uh +f is also in the subtree of d f is in + + align:start position:0% +f is also in the subtree of d f is in + + + align:start position:0% +f is also in the subtree of d f is in +the sub tree of b like i drew + + align:start position:0% +the sub tree of b like i drew + + + align:start position:0% +the sub tree of b like i drew +f is in the subtree of a it's in the + + align:start position:0% +f is in the subtree of a it's in the + + + align:start position:0% +f is in the subtree of a it's in the +subtree of exactly its ancestors + + align:start position:0% + + + + align:start position:0% + +but in this operation when we define + + align:start position:0% +but in this operation when we define + + + align:start position:0% +but in this operation when we define +node + + align:start position:0% +node + + + align:start position:0% +node +our node only defines one sub-tree it is + + align:start position:0% +our node only defines one sub-tree it is + + + align:start position:0% +our node only defines one sub-tree it is +the root of only one sub-tree + + align:start position:0% +the root of only one sub-tree + + + align:start position:0% +the root of only one sub-tree +and that's the sub-tree we're talking + + align:start position:0% +and that's the sub-tree we're talking + + + align:start position:0% +and that's the sub-tree we're talking +about and then i want to know among all + + align:start position:0% +about and then i want to know among all + + + align:start position:0% +about and then i want to know among all +those nodes which includes node itself + + align:start position:0% +those nodes which includes node itself + + + align:start position:0% +those nodes which includes node itself +and other things uh which one comes + + align:start position:0% +and other things uh which one comes + + + align:start position:0% +and other things uh which one comes +first + + align:start position:0% +first + + + align:start position:0% +first +in this traversal order this is like + + align:start position:0% +in this traversal order this is like + + + align:start position:0% +in this traversal order this is like +practice with traversal orders + + align:start position:0% +practice with traversal orders + + + align:start position:0% +practice with traversal orders +so where should i look for this node + + align:start position:0% + + + + align:start position:0% + +yeah the leftmost leaf + + align:start position:0% +yeah the leftmost leaf + + + align:start position:0% +yeah the leftmost leaf +in the picture it's here but pictures + + align:start position:0% +in the picture it's here but pictures + + + align:start position:0% +in the picture it's here but pictures +can be deceiving + + align:start position:0% +can be deceiving + + + align:start position:0% +can be deceiving +we just want to go left + + align:start position:0% +we just want to go left + + + align:start position:0% +we just want to go left +as much as possible when i say go left i + + align:start position:0% +as much as possible when i say go left i + + + align:start position:0% +as much as possible when i say go left i +mean this iteration node equals + + align:start position:0% + + + + align:start position:0% + +node.left you just look at our + + align:start position:0% +node.left you just look at our + + + align:start position:0% +node.left you just look at our +definition + + align:start position:0% +definition + + + align:start position:0% +definition +all the nodes on the left come before x + + align:start position:0% +all the nodes on the left come before x + + + align:start position:0% +all the nodes on the left come before x +and all the nodes in the right so + + align:start position:0% +and all the nodes in the right so + + + align:start position:0% +and all the nodes in the right so +it's got to be in the left subtree if + + align:start position:0% +it's got to be in the left subtree if + + + align:start position:0% +it's got to be in the left subtree if +there is one uh + + align:start position:0% +there is one uh + + + align:start position:0% +there is one uh +of course we can't do this forever so + + align:start position:0% +of course we can't do this forever so + + + align:start position:0% +of course we can't do this forever so +say until we would fall off the tree + + align:start position:0% + + + + align:start position:0% + +which means uh node is none + + align:start position:0% + + + + align:start position:0% + +okay but we stopped uh before that would + + align:start position:0% +okay but we stopped uh before that would + + + align:start position:0% +okay but we stopped uh before that would +happen + + align:start position:0% +happen + + + align:start position:0% +happen +so this is like uh the directions like + + align:start position:0% +so this is like uh the directions like + + + align:start position:0% +so this is like uh the directions like +oh you keep driving until you see the + + align:start position:0% +oh you keep driving until you see the + + + align:start position:0% +oh you keep driving until you see the +store + + align:start position:0% +store + + + align:start position:0% +store +and it's the block right before that + + align:start position:0% +and it's the block right before that + + + align:start position:0% +and it's the block right before that +it's like well that's not very helpful + + align:start position:0% +it's like well that's not very helpful + + + align:start position:0% +it's like well that's not very helpful +so uh you keep iterating node equals no + + align:start position:0% +so uh you keep iterating node equals no + + + align:start position:0% +so uh you keep iterating node equals no +dot left until node becomes + + align:start position:0% +dot left until node becomes + + + align:start position:0% +dot left until node becomes +none and then you undo one step okay you + + align:start position:0% +none and then you undo one step okay you + + + align:start position:0% +none and then you undo one step okay you +all know how to program that it's not + + align:start position:0% +all know how to program that it's not + + + align:start position:0% +all know how to program that it's not +hard + + align:start position:0% +hard + + + align:start position:0% +hard +um so that last non-none + + align:start position:0% +um so that last non-none + + + align:start position:0% +um so that last non-none +node which might actually be the root it + + align:start position:0% +node which might actually be the root it + + + align:start position:0% +node which might actually be the root it +might be node + + align:start position:0% +might be node + + + align:start position:0% +might be node +maybe it has no left children but in + + align:start position:0% +maybe it has no left children but in + + + align:start position:0% +maybe it has no left children but in +that case i claim node is the very first + + align:start position:0% +that case i claim node is the very first + + + align:start position:0% +that case i claim node is the very first +in its in its subtree traversal order + + align:start position:0% +in its in its subtree traversal order + + + align:start position:0% +in its in its subtree traversal order +because + + align:start position:0% +because + + + align:start position:0% +because +if there are no nodes in the left that + + align:start position:0% +if there are no nodes in the left that + + + align:start position:0% +if there are no nodes in the left that +come before x then x is actually first + + align:start position:0% +come before x then x is actually first + + + align:start position:0% +come before x then x is actually first +okay and that so that's it uh return + + align:start position:0% +okay and that so that's it uh return + + + align:start position:0% +okay and that so that's it uh return +node + + align:start position:0% + + + + align:start position:0% + +so i'm modifying node in place here and + + align:start position:0% +so i'm modifying node in place here and + + + align:start position:0% +so i'm modifying node in place here and +the very last one before i hit none + + align:start position:0% +the very last one before i hit none + + + align:start position:0% +the very last one before i hit none +that's the minimum + + align:start position:0% +that's the minimum + + + align:start position:0% +that's the minimum +that's the first item in the traversal + + align:start position:0% +that's the first item in the traversal + + + align:start position:0% +that's the first item in the traversal +order similarly you can define subtree + + align:start position:0% +order similarly you can define subtree + + + align:start position:0% +order similarly you can define subtree +last + + align:start position:0% +last + + + align:start position:0% +last +okay let's do a more interesting one + + align:start position:0% +okay let's do a more interesting one + + + align:start position:0% +okay let's do a more interesting one +successor + + align:start position:0% + + + + align:start position:0% + +node so in this case i want to know what + + align:start position:0% +node so in this case i want to know what + + + align:start position:0% +node so in this case i want to know what +is + + align:start position:0% +is + + + align:start position:0% +is +the next + + align:start position:0% + + + + align:start position:0% + +after node in the + + align:start position:0% +after node in the + + + align:start position:0% +after node in the +overall tree's traversal order okay here + + align:start position:0% +overall tree's traversal order okay here + + + align:start position:0% +overall tree's traversal order okay here +i was restricting to + + align:start position:0% +i was restricting to + + + align:start position:0% +i was restricting to +uh a single sub tree now i'm thinking + + align:start position:0% +uh a single sub tree now i'm thinking + + + align:start position:0% +uh a single sub tree now i'm thinking +about the entire tree in the entire + + align:start position:0% +about the entire tree in the entire + + + align:start position:0% +about the entire tree in the entire +traversal order + + align:start position:0% +traversal order + + + align:start position:0% +traversal order +and given a node i want to know which + + align:start position:0% +and given a node i want to know which + + + align:start position:0% +and given a node i want to know which +one comes next + + align:start position:0% +one comes next + + + align:start position:0% +one comes next +call this the successor i feel like i + + align:start position:0% +call this the successor i feel like i + + + align:start position:0% +call this the successor i feel like i +should + + align:start position:0% +should + + + align:start position:0% +should +make some kind of royal family joke now + + align:start position:0% +make some kind of royal family joke now + + + align:start position:0% +make some kind of royal family joke now +but + + align:start position:0% +but + + + align:start position:0% +but +i don't know how um so + + align:start position:0% +i don't know how um so + + + align:start position:0% +i don't know how um so +every node has a unique successor let's + + align:start position:0% +every node has a unique successor let's + + + align:start position:0% +every node has a unique successor let's +do let's do some examples + + align:start position:0% +do let's do some examples + + + align:start position:0% +do let's do some examples +so we can start with f the successor of + + align:start position:0% +so we can start with f the successor of + + + align:start position:0% +so we can start with f the successor of +f if we just index into this + + align:start position:0% +f if we just index into this + + + align:start position:0% +f if we just index into this +list the successor is d okay + + align:start position:0% +list the successor is d okay + + + align:start position:0% +list the successor is d okay +successor of d is b successor b is ease + + align:start position:0% +successor of d is b successor b is ease + + + align:start position:0% +successor of d is b successor b is ease +okay it's very easy to read successors + + align:start position:0% +okay it's very easy to read successors + + + align:start position:0% +okay it's very easy to read successors +off + + align:start position:0% +off + + + align:start position:0% +off +when i have the traversal order written + + align:start position:0% +when i have the traversal order written + + + align:start position:0% +when i have the traversal order written +down but let's think about how to do it + + align:start position:0% +down but let's think about how to do it + + + align:start position:0% +down but let's think about how to do it +in the tree + + align:start position:0% +in the tree + + + align:start position:0% +in the tree +okay uh + + align:start position:0% + + + + align:start position:0% + +let's see there are going to be two + + align:start position:0% +let's see there are going to be two + + + align:start position:0% +let's see there are going to be two +cases + + align:start position:0% +cases + + + align:start position:0% +cases +if i look at the successor of a it has a + + align:start position:0% +if i look at the successor of a it has a + + + align:start position:0% +if i look at the successor of a it has a +right child + + align:start position:0% +right child + + + align:start position:0% +right child +and in this case the right child of a is + + align:start position:0% +and in this case the right child of a is + + + align:start position:0% +and in this case the right child of a is +the successor but that's not always the + + align:start position:0% +the successor but that's not always the + + + align:start position:0% +the successor but that's not always the +case + + align:start position:0% +case + + + align:start position:0% +case +i don't have a good example but if i had + + align:start position:0% +i don't have a good example but if i had + + + align:start position:0% +i don't have a good example but if i had +another node here let's call it + + align:start position:0% +another node here let's call it + + + align:start position:0% +another node here let's call it +g uh the successor of a + + align:start position:0% +g uh the successor of a + + + align:start position:0% +g uh the successor of a +is actually g right because + + align:start position:0% +is actually g right because + + + align:start position:0% +is actually g right because +all of these items come after a in the + + align:start position:0% +all of these items come after a in the + + + align:start position:0% +all of these items come after a in the +order + + align:start position:0% +order + + + align:start position:0% +order +but which one comes first the leftmost + + align:start position:0% +but which one comes first the leftmost + + + align:start position:0% +but which one comes first the leftmost +leaf + + align:start position:0% +leaf + + + align:start position:0% +leaf +okay that's the problem we just solved + + align:start position:0% +okay that's the problem we just solved + + + align:start position:0% +okay that's the problem we just solved +so if a has a right child + + align:start position:0% +so if a has a right child + + + align:start position:0% +so if a has a right child +what we want is the leftmost leaf the + + align:start position:0% +what we want is the leftmost leaf the + + + align:start position:0% +what we want is the leftmost leaf the +first + + align:start position:0% +first + + + align:start position:0% +first +thing in that subtree + + align:start position:0% + + + + align:start position:0% + +the right subtree right child sub tree + + align:start position:0% +the right subtree right child sub tree + + + align:start position:0% +the right subtree right child sub tree +so this is case one + + align:start position:0% +so this is case one + + + align:start position:0% +so this is case one +if uh node.right + + align:start position:0% +if uh node.right + + + align:start position:0% +if uh node.right +so if we have a right child then + + align:start position:0% +so if we have a right child then + + + align:start position:0% +so if we have a right child then +what we want is + + align:start position:0% + + + + align:start position:0% + +subtree first + + align:start position:0% + + + + align:start position:0% + +of the right child + + align:start position:0% + + + + align:start position:0% + +great we can reduce to this other + + align:start position:0% +great we can reduce to this other + + + align:start position:0% +great we can reduce to this other +operation + + align:start position:0% +operation + + + align:start position:0% +operation +but what if the node doesn't have a + + align:start position:0% +but what if the node doesn't have a + + + align:start position:0% +but what if the node doesn't have a +right child + + align:start position:0% +right child + + + align:start position:0% +right child +so for example it could be a leaf say + + align:start position:0% +so for example it could be a leaf say + + + align:start position:0% +so for example it could be a leaf say +we're taking + + align:start position:0% +we're taking + + + align:start position:0% +we're taking +the successor of i mean it doesn't have + + align:start position:0% +the successor of i mean it doesn't have + + + align:start position:0% +the successor of i mean it doesn't have +to be a leaf could be f which has no + + align:start position:0% +to be a leaf could be f which has no + + + align:start position:0% +to be a leaf could be f which has no +children it could be d which has one + + align:start position:0% +children it could be d which has one + + + align:start position:0% +children it could be d which has one +child but no right child + + align:start position:0% +child but no right child + + + align:start position:0% +child but no right child +so what's the successor of f well it's d + + align:start position:0% +so what's the successor of f well it's d + + + align:start position:0% +so what's the successor of f well it's d +which in this case is the parent but + + align:start position:0% +which in this case is the parent but + + + align:start position:0% +which in this case is the parent but +it's not always for example if we do + + align:start position:0% +it's not always for example if we do + + + align:start position:0% +it's not always for example if we do +successor of e + + align:start position:0% +successor of e + + + align:start position:0% +successor of e +its parent is actually earlier in the + + align:start position:0% +its parent is actually earlier in the + + + align:start position:0% +its parent is actually earlier in the +order because e was a right child + + align:start position:0% +order because e was a right child + + + align:start position:0% +order because e was a right child +here f was a left child and so its + + align:start position:0% +here f was a left child and so its + + + align:start position:0% +here f was a left child and so its +parent + + align:start position:0% +parent + + + align:start position:0% +parent +was after + + align:start position:0% + + + + align:start position:0% + +successor of d happens to be b because + + align:start position:0% +successor of d happens to be b because + + + align:start position:0% +successor of d happens to be b because +uh it's per it was the left child of its + + align:start position:0% +uh it's per it was the left child of its + + + align:start position:0% +uh it's per it was the left child of its +parent + + align:start position:0% +parent + + + align:start position:0% +parent +okay so that seems like the easy case if + + align:start position:0% +okay so that seems like the easy case if + + + align:start position:0% +okay so that seems like the easy case if +we're the left child of our parent + + align:start position:0% +we're the left child of our parent + + + align:start position:0% +we're the left child of our parent +then our successor is our parent okay + + align:start position:0% +then our successor is our parent okay + + + align:start position:0% +then our successor is our parent okay +basing on this small example but we can + + align:start position:0% +basing on this small example but we can + + + align:start position:0% +basing on this small example but we can +argue it generally in a moment + + align:start position:0% +argue it generally in a moment + + + align:start position:0% +argue it generally in a moment +what's the successor of e uh well it's + + align:start position:0% +what's the successor of e uh well it's + + + align:start position:0% +what's the successor of e uh well it's +not b because that comes earlier in fact + + align:start position:0% +not b because that comes earlier in fact + + + align:start position:0% +not b because that comes earlier in fact +all the things in this in b sub tree + + align:start position:0% +all the things in this in b sub tree + + + align:start position:0% +all the things in this in b sub tree +come earlier or equal to + + align:start position:0% +come earlier or equal to + + + align:start position:0% +come earlier or equal to +e um so we have to keep going up + + align:start position:0% +e um so we have to keep going up + + + align:start position:0% +e um so we have to keep going up +and then it turns out the successor of e + + align:start position:0% +and then it turns out the successor of e + + + align:start position:0% +and then it turns out the successor of e +is a because this subtree + + align:start position:0% +is a because this subtree + + + align:start position:0% +is a because this subtree +was the left child of a because b was a + + align:start position:0% +was the left child of a because b was a + + + align:start position:0% +was the left child of a because b was a +left child with a + + align:start position:0% +left child with a + + + align:start position:0% +left child with a +so the general strategy is walk up the + + align:start position:0% +so the general strategy is walk up the + + + align:start position:0% +so the general strategy is walk up the +tree + + align:start position:0% +tree + + + align:start position:0% +tree +until we are we we go + + align:start position:0% +until we are we we go + + + align:start position:0% +until we are we we go +up a traversal whose reverse direction + + align:start position:0% +up a traversal whose reverse direction + + + align:start position:0% +up a traversal whose reverse direction +would be left + + align:start position:0% +would be left + + + align:start position:0% +would be left +okay so um walk + + align:start position:0% +okay so um walk + + + align:start position:0% +okay so um walk +up the tree when i say walk up i mean + + align:start position:0% +up the tree when i say walk up i mean + + + align:start position:0% +up the tree when i say walk up i mean +node equals node.parent + + align:start position:0% +node equals node.parent + + + align:start position:0% +node equals node.parent +iteration + + align:start position:0% + + + + align:start position:0% + +until + + align:start position:0% + + + + align:start position:0% + +we go up a left + + align:start position:0% +we go up a left + + + align:start position:0% +we go up a left +branch + + align:start position:0% + + + + align:start position:0% + +so this would mean that node before we + + align:start position:0% +so this would mean that node before we + + + align:start position:0% +so this would mean that node before we +do the change + + align:start position:0% +do the change + + + align:start position:0% +do the change +node equals node.parent node.parent.left + + align:start position:0% + + + + align:start position:0% + +okay so we can check that and then after + + align:start position:0% +okay so we can check that and then after + + + align:start position:0% +okay so we can check that and then after +we do that traversal that parent + + align:start position:0% +we do that traversal that parent + + + align:start position:0% +we do that traversal that parent +is exactly the node we're looking for + + align:start position:0% +is exactly the node we're looking for + + + align:start position:0% +is exactly the node we're looking for +okay why is this true in general let me + + align:start position:0% +okay why is this true in general let me + + + align:start position:0% +okay why is this true in general let me +draw a more generic picture + + align:start position:0% +draw a more generic picture + + + align:start position:0% +draw a more generic picture +so we're starting at some node + + align:start position:0% + + + + align:start position:0% + +and let's say its parent is to the right + + align:start position:0% +and let's say its parent is to the right + + + align:start position:0% +and let's say its parent is to the right +so it comes later in the order + + align:start position:0% +so it comes later in the order + + + align:start position:0% +so it comes later in the order +for a while sorry get this backwards + + align:start position:0% +for a while sorry get this backwards + + + align:start position:0% +for a while sorry get this backwards +we're doing successor + + align:start position:0% + + + + align:start position:0% + +so it goes to left for a while + + align:start position:0% +so it goes to left for a while + + + align:start position:0% +so it goes to left for a while +so these are all these nodes will come + + align:start position:0% +so these are all these nodes will come + + + align:start position:0% +so these are all these nodes will come +earlier in the order because by the + + align:start position:0% +earlier in the order because by the + + + align:start position:0% +earlier in the order because by the +definition everything in the right + + align:start position:0% +definition everything in the right + + + align:start position:0% +definition everything in the right +subtree comes after + + align:start position:0% +subtree comes after + + + align:start position:0% +subtree comes after +and at some point we have a parent + + align:start position:0% +and at some point we have a parent + + + align:start position:0% +and at some point we have a parent +that's to the right meaning this node + + align:start position:0% +that's to the right meaning this node + + + align:start position:0% +that's to the right meaning this node +was the left + + align:start position:0% +was the left + + + align:start position:0% +was the left +child of this parent and that node by + + align:start position:0% +child of this parent and that node by + + + align:start position:0% +child of this parent and that node by +definition will come + + align:start position:0% +definition will come + + + align:start position:0% +definition will come +after all of the nodes in here + + align:start position:0% +after all of the nodes in here + + + align:start position:0% +after all of the nodes in here +and could there be anything in between + + align:start position:0% +and could there be anything in between + + + align:start position:0% +and could there be anything in between +node and this + + align:start position:0% +node and this + + + align:start position:0% +node and this +uh this parent grandparent ancestor + + align:start position:0% +uh this parent grandparent ancestor + + + align:start position:0% +uh this parent grandparent ancestor +only if there was something in this + + align:start position:0% +only if there was something in this + + + align:start position:0% +only if there was something in this +subtree and we're in the case here + + align:start position:0% +subtree and we're in the case here + + + align:start position:0% +subtree and we're in the case here +where there is no right subtree of our + + align:start position:0% +where there is no right subtree of our + + + align:start position:0% +where there is no right subtree of our +original node + + align:start position:0% +original node + + + align:start position:0% +original node +so this this is where all the nodes in + + align:start position:0% +so this this is where all the nodes in + + + align:start position:0% +so this this is where all the nodes in +between node and here would be + + align:start position:0% +between node and here would be + + + align:start position:0% +between node and here would be +but there aren't any and therefore this + + align:start position:0% +but there aren't any and therefore this + + + align:start position:0% +but there aren't any and therefore this +is the successor + + align:start position:0% +is the successor + + + align:start position:0% +is the successor +so that's sort of the general argument + + align:start position:0% +so that's sort of the general argument + + + align:start position:0% +so that's sort of the general argument +why this + + align:start position:0% +why this + + + align:start position:0% +why this +works i see a question yeah + + align:start position:0% +works i see a question yeah + + + align:start position:0% +works i see a question yeah +placed into the traverse order so the + + align:start position:0% +placed into the traverse order so the + + + align:start position:0% +placed into the traverse order so the +traversal order is never explicitly + + align:start position:0% +traversal order is never explicitly + + + align:start position:0% +traversal order is never explicitly +computed + + align:start position:0% +computed + + + align:start position:0% +computed +what we're taught it's always implicit + + align:start position:0% +what we're taught it's always implicit + + + align:start position:0% +what we're taught it's always implicit +we can't afford to maintain + + align:start position:0% +we can't afford to maintain + + + align:start position:0% +we can't afford to maintain +this as say an array this is just + + align:start position:0% +this as say an array this is just + + + align:start position:0% +this as say an array this is just +in our heads maybe i will draw it with a + + align:start position:0% +in our heads maybe i will draw it with a + + + align:start position:0% +in our heads maybe i will draw it with a +cloud around it we're just thinking this + + align:start position:0% +cloud around it we're just thinking this + + + align:start position:0% +cloud around it we're just thinking this +okay it's not in the computer explicitly + + align:start position:0% +okay it's not in the computer explicitly + + + align:start position:0% +okay it's not in the computer explicitly +in the computer all we store is this + + align:start position:0% +in the computer all we store is this + + + align:start position:0% +in the computer all we store is this +and the reason is this is expensive we + + align:start position:0% +and the reason is this is expensive we + + + align:start position:0% +and the reason is this is expensive we +don't we can't maintain an array of + + align:start position:0% +don't we can't maintain an array of + + + align:start position:0% +don't we can't maintain an array of +things and be able to insert in the + + align:start position:0% +things and be able to insert in the + + + align:start position:0% +things and be able to insert in the +middle + + align:start position:0% +middle + + + align:start position:0% +middle +whereas this is cheap i can afford to + + align:start position:0% +whereas this is cheap i can afford to + + + align:start position:0% +whereas this is cheap i can afford to +maintain this structure + + align:start position:0% +maintain this structure + + + align:start position:0% +maintain this structure +and do all these things and so the + + align:start position:0% +and do all these things and so the + + + align:start position:0% +and do all these things and so the +reason we're talking about these + + align:start position:0% +reason we're talking about these + + + align:start position:0% +reason we're talking about these +operations is they're letting us + + align:start position:0% +operations is they're letting us + + + align:start position:0% +operations is they're letting us +manipulate the order or in this case + + align:start position:0% +manipulate the order or in this case + + + align:start position:0% +manipulate the order or in this case +letting us + + align:start position:0% +letting us + + + align:start position:0% +letting us +iterate through the order so this was an + + align:start position:0% +iterate through the order so this was an + + + align:start position:0% +iterate through the order so this was an +algorithm for iterating through the + + align:start position:0% +algorithm for iterating through the + + + align:start position:0% +algorithm for iterating through the +entire order + + align:start position:0% +entire order + + + align:start position:0% +entire order +but that takes linear time this was + + align:start position:0% +but that takes linear time this was + + + align:start position:0% +but that takes linear time this was +getting started in the order find me the + + align:start position:0% +getting started in the order find me the + + + align:start position:0% +getting started in the order find me the +first + + align:start position:0% +first + + + align:start position:0% +first +first thing the order and this was given + + align:start position:0% +first thing the order and this was given + + + align:start position:0% +first thing the order and this was given +one node find me the next one + + align:start position:0% +one node find me the next one + + + align:start position:0% +one node find me the next one +how long do these operations take + + align:start position:0% + + + + align:start position:0% + +right at most the height of the entire + + align:start position:0% +right at most the height of the entire + + + align:start position:0% +right at most the height of the entire +tree in fact it's going to be + + align:start position:0% +tree in fact it's going to be + + + align:start position:0% +tree in fact it's going to be +the depth of that first node but in the + + align:start position:0% +the depth of that first node but in the + + + align:start position:0% +the depth of that first node but in the +worst case that's the height of the + + align:start position:0% +worst case that's the height of the + + + align:start position:0% +worst case that's the height of the +entire tree + + align:start position:0% +entire tree + + + align:start position:0% +entire tree +in general all of these operations are + + align:start position:0% +in general all of these operations are + + + align:start position:0% +in general all of these operations are +going to be order h + + align:start position:0% +going to be order h + + + align:start position:0% +going to be order h +we need to think about it in each case + + align:start position:0% +we need to think about it in each case + + + align:start position:0% +we need to think about it in each case +except for this one which is order n + + align:start position:0% +except for this one which is order n + + + align:start position:0% +except for this one which is order n +so iterating through the whole thing um + + align:start position:0% +so iterating through the whole thing um + + + align:start position:0% +so iterating through the whole thing um +this in this case we're just calling + + align:start position:0% +this in this case we're just calling + + + align:start position:0% +this in this case we're just calling +subtree first so + + align:start position:0% +subtree first so + + + align:start position:0% +subtree first so +that takes order h time here we're + + align:start position:0% +that takes order h time here we're + + + align:start position:0% +that takes order h time here we're +walking up the tree instead of down but + + align:start position:0% +walking up the tree instead of down but + + + align:start position:0% +walking up the tree instead of down but +that's going to cost + + align:start position:0% +that's going to cost + + + align:start position:0% +that's going to cost +exactly the height of the node we happen + + align:start position:0% +exactly the height of the node we happen + + + align:start position:0% +exactly the height of the node we happen +to stop early but worst case order h + + align:start position:0% +to stop early but worst case order h + + + align:start position:0% +to stop early but worst case order h +for all this all the operations we + + align:start position:0% +for all this all the operations we + + + align:start position:0% +for all this all the operations we +consider today we just want to get an + + align:start position:0% +consider today we just want to get an + + + align:start position:0% +consider today we just want to get an +order h bound + + align:start position:0% +order h bound + + + align:start position:0% +order h bound +and later we will bound h so the point + + align:start position:0% +and later we will bound h so the point + + + align:start position:0% +and later we will bound h so the point +is these are + + align:start position:0% +is these are + + + align:start position:0% +is these are +fast if h is small like log n these are + + align:start position:0% +fast if h is small like log n these are + + + align:start position:0% +fast if h is small like log n these are +almost instantaneous + + align:start position:0% +almost instantaneous + + + align:start position:0% +almost instantaneous +whereas if i had to update the explicit + + align:start position:0% +whereas if i had to update the explicit + + + align:start position:0% +whereas if i had to update the explicit +traversal order + + align:start position:0% +traversal order + + + align:start position:0% +traversal order +say as an array i would have to spend + + align:start position:0% +say as an array i would have to spend + + + align:start position:0% +say as an array i would have to spend +linear time every time i make a change + + align:start position:0% +linear time every time i make a change + + + align:start position:0% +linear time every time i make a change +and yes it would be fast to do successor + + align:start position:0% +and yes it would be fast to do successor + + + align:start position:0% +and yes it would be fast to do successor +if i had this stored explicitly + + align:start position:0% +if i had this stored explicitly + + + align:start position:0% +if i had this stored explicitly +but maintaining it would be impossible + + align:start position:0% +but maintaining it would be impossible + + + align:start position:0% +but maintaining it would be impossible +maintaining it efficiently would be + + align:start position:0% +maintaining it efficiently would be + + + align:start position:0% +maintaining it efficiently would be +impossible + + align:start position:0% +impossible + + + align:start position:0% +impossible +question questions + + align:start position:0% + + + + align:start position:0% + +yes okay + + align:start position:0% + + + + align:start position:0% + +cool um so these were queries + + align:start position:0% +cool um so these were queries + + + align:start position:0% +cool um so these were queries +where i want to follow + + align:start position:0% +where i want to follow + + + align:start position:0% +where i want to follow +see what's what's next in the traversal + + align:start position:0% +see what's what's next in the traversal + + + align:start position:0% +see what's what's next in the traversal +sequence now let's talk about actually + + align:start position:0% +sequence now let's talk about actually + + + align:start position:0% +sequence now let's talk about actually +changing the traversal sequence so these + + align:start position:0% +changing the traversal sequence so these + + + align:start position:0% +changing the traversal sequence so these +are insert and delete operations + + align:start position:0% +are insert and delete operations + + + align:start position:0% +are insert and delete operations +these will correspond roughly to insert + + align:start position:0% +these will correspond roughly to insert + + + align:start position:0% +these will correspond roughly to insert +at or delete at + + align:start position:0% +at or delete at + + + align:start position:0% +at or delete at +but they're not quite we're not quite in + + align:start position:0% +but they're not quite we're not quite in + + + align:start position:0% +but they're not quite we're not quite in +sequence world yet + + align:start position:0% +sequence world yet + + + align:start position:0% +sequence world yet +instead we're going to focus on + + align:start position:0% +instead we're going to focus on + + + align:start position:0% +instead we're going to focus on +inserting or deleting in the middle + + align:start position:0% +inserting or deleting in the middle + + + align:start position:0% +inserting or deleting in the middle +of a subtree + + align:start position:0% + + + + align:start position:0% + +so i'm going to have two nodes + + align:start position:0% + + + + align:start position:0% + +so the + + align:start position:0% + + + + align:start position:0% + +in the traversal order + + align:start position:0% +in the traversal order + + + align:start position:0% +in the traversal order +so node already exists in the tree new + + align:start position:0% +so node already exists in the tree new + + + align:start position:0% +so node already exists in the tree new +is a new node that does not yet exist in + + align:start position:0% +is a new node that does not yet exist in + + + align:start position:0% +is a new node that does not yet exist in +the tree hence i call it new + + align:start position:0% +the tree hence i call it new + + + align:start position:0% +the tree hence i call it new +and what i'd like to do is insert new + + align:start position:0% +and what i'd like to do is insert new + + + align:start position:0% +and what i'd like to do is insert new +right after node and there's a symmetric + + align:start position:0% +right after node and there's a symmetric + + + align:start position:0% +right after node and there's a symmetric +operation which is insert before + + align:start position:0% +operation which is insert before + + + align:start position:0% +operation which is insert before +it will be implemented almost + + align:start position:0% +it will be implemented almost + + + align:start position:0% +it will be implemented almost +identically so we'll just focus on after + + align:start position:0% +identically so we'll just focus on after + + + align:start position:0% +identically so we'll just focus on after +so i want to insert this new node in the + + align:start position:0% +so i want to insert this new node in the + + + align:start position:0% +so i want to insert this new node in the +traversal order which again is in our + + align:start position:0% +traversal order which again is in our + + + align:start position:0% +traversal order which again is in our +heads this is all + + align:start position:0% +heads this is all + + + align:start position:0% +heads this is all +in in our thought bubble + + align:start position:0% + + + + align:start position:0% + +that's what we want to achieve and we + + align:start position:0% +that's what we want to achieve and we + + + align:start position:0% +that's what we want to achieve and we +have to do it by manipulating + + align:start position:0% +have to do it by manipulating + + + align:start position:0% +have to do it by manipulating +this tree and however we change the tree + + align:start position:0% +this tree and however we change the tree + + + align:start position:0% +this tree and however we change the tree +it defines a new traversal order + + align:start position:0% +it defines a new traversal order + + + align:start position:0% +it defines a new traversal order +so maybe let's do an example first + + align:start position:0% + + + + align:start position:0% + +actually i probably want this universal + + align:start position:0% +actually i probably want this universal + + + align:start position:0% +actually i probably want this universal +order + + align:start position:0% +order + + + align:start position:0% +order +keep track of that so uh + + align:start position:0% +keep track of that so uh + + + align:start position:0% +keep track of that so uh +let's say the first thing we want to do + + align:start position:0% +let's say the first thing we want to do + + + align:start position:0% +let's say the first thing we want to do +uh is insert + + align:start position:0% + + + + align:start position:0% + +g before e + + align:start position:0% +g before e + + + align:start position:0% +g before e +i want to illustrate both of the + + align:start position:0% +i want to illustrate both of the + + + align:start position:0% +i want to illustrate both of the +operations + + align:start position:0% +operations + + + align:start position:0% +operations +insert h + + align:start position:0% +insert h + + + align:start position:0% +insert h +after e + + align:start position:0% +after e + + + align:start position:0% +after e +a + + align:start position:0% + + + + align:start position:0% + +okay um + + align:start position:0% + + + + align:start position:0% + +so insert g before e so conceptually + + align:start position:0% +so insert g before e so conceptually + + + align:start position:0% +so insert g before e so conceptually +what we want to do is insert g + + align:start position:0% +what we want to do is insert g + + + align:start position:0% +what we want to do is insert g +here and the way so we're given the node + + align:start position:0% +here and the way so we're given the node + + + align:start position:0% +here and the way so we're given the node +e + + align:start position:0% +e + + + align:start position:0% +e +and we're given a sort of empty node i + + align:start position:0% +and we're given a sort of empty node i + + + align:start position:0% +and we're given a sort of empty node i +mean a node that just contains g it + + align:start position:0% +mean a node that just contains g it + + + align:start position:0% +mean a node that just contains g it +doesn't have any pointers yet + + align:start position:0% +doesn't have any pointers yet + + + align:start position:0% +doesn't have any pointers yet +and we would like to put it before e + + align:start position:0% +and we would like to put it before e + + + align:start position:0% +and we would like to put it before e +where should i put it + + align:start position:0% +where should i put it + + + align:start position:0% +where should i put it +left child all right so that's + + align:start position:0% +left child all right so that's + + + align:start position:0% +left child all right so that's +this is an easy case if i'm trying to + + align:start position:0% +this is an easy case if i'm trying to + + + align:start position:0% +this is an easy case if i'm trying to +insert before and there's no left child + + align:start position:0% +insert before and there's no left child + + + align:start position:0% +insert before and there's no left child +stick it there if i'm trying to insert + + align:start position:0% +stick it there if i'm trying to insert + + + align:start position:0% +stick it there if i'm trying to insert +after and there's no right child + + align:start position:0% +after and there's no right child + + + align:start position:0% +after and there's no right child +stick it there easy so let me write down + + align:start position:0% +stick it there easy so let me write down + + + align:start position:0% +stick it there easy so let me write down +case one + + align:start position:0% + + + + align:start position:0% + +so here we're inserting after so if + + align:start position:0% +so here we're inserting after so if + + + align:start position:0% +so here we're inserting after so if +there's no + + align:start position:0% +there's no + + + align:start position:0% +there's no +uh right child + + align:start position:0% + + + + align:start position:0% + +put new + + align:start position:0% +put new + + + align:start position:0% +put new +there okay i'm using informal language + + align:start position:0% +there okay i'm using informal language + + + align:start position:0% +there okay i'm using informal language +here putting + + align:start position:0% +here putting + + + align:start position:0% +here putting +this new node there + + align:start position:0% +this new node there + + + align:start position:0% +this new node there +b instead of writing for example + + align:start position:0% +b instead of writing for example + + + align:start position:0% +b instead of writing for example +node.write equals new + + align:start position:0% +node.write equals new + + + align:start position:0% +node.write equals new +because that's only one operation you + + align:start position:0% +because that's only one operation you + + + align:start position:0% +because that's only one operation you +need to do one thing you would do is set + + align:start position:0% +need to do one thing you would do is set + + + align:start position:0% +need to do one thing you would do is set +node.write equals to new but you also + + align:start position:0% +node.write equals to new but you also + + + align:start position:0% +node.write equals to new but you also +have to set new's parent to be + + align:start position:0% +have to set new's parent to be + + + align:start position:0% +have to set new's parent to be +node.write + + align:start position:0% +node.write + + + align:start position:0% +node.write +so instead of worrying about those two + + align:start position:0% +so instead of worrying about those two + + + align:start position:0% +so instead of worrying about those two +pointer changes because we always do + + align:start position:0% +pointer changes because we always do + + + align:start position:0% +pointer changes because we always do +bi-directional pointer changes i'm just + + align:start position:0% +bi-directional pointer changes i'm just + + + align:start position:0% +bi-directional pointer changes i'm just +going to use + + align:start position:0% +going to use + + + align:start position:0% +going to use +pseudocode and then in recitation you'll + + align:start position:0% +pseudocode and then in recitation you'll + + + align:start position:0% +pseudocode and then in recitation you'll +see actual python code that does all + + align:start position:0% +see actual python code that does all + + + align:start position:0% +see actual python code that does all +this + + align:start position:0% +this + + + align:start position:0% +this +uh so then there's the other case + + align:start position:0% + + + + align:start position:0% + +so that should be the second example + + align:start position:0% +so that should be the second example + + + align:start position:0% +so that should be the second example +insert h + + align:start position:0% +insert h + + + align:start position:0% +insert h +after a right + + align:start position:0% +after a right + + + align:start position:0% +after a right +insert h after a so we already have a + + align:start position:0% +insert h after a so we already have a + + + align:start position:0% +insert h after a so we already have a +node after a + + align:start position:0% +node after a + + + align:start position:0% +node after a +in the right child in this right subtree + + align:start position:0% + + + + align:start position:0% + +so where do i want to put + + align:start position:0% +so where do i want to put + + + align:start position:0% +so where do i want to put +h relative to a + + align:start position:0% +h relative to a + + + align:start position:0% +h relative to a +well it should be to the right of a but + + align:start position:0% +well it should be to the right of a but + + + align:start position:0% +well it should be to the right of a but +it should be + + align:start position:0% +it should be + + + align:start position:0% +it should be +before c it should be to the left of c + + align:start position:0% +before c it should be to the left of c + + + align:start position:0% +before c it should be to the left of c +so that would mean we want to put it + + align:start position:0% +so that would mean we want to put it + + + align:start position:0% +so that would mean we want to put it +here okay in this case it was pretty + + align:start position:0% +here okay in this case it was pretty + + + align:start position:0% +here okay in this case it was pretty +easy because this tree was small + + align:start position:0% +easy because this tree was small + + + align:start position:0% +easy because this tree was small +where do i want to put it in general + + align:start position:0% +where do i want to put it in general + + + align:start position:0% +where do i want to put it in general +well wherever + + align:start position:0% + + + + align:start position:0% + +subtree first tells me to put it right + + align:start position:0% +subtree first tells me to put it right + + + align:start position:0% +subtree first tells me to put it right +subtree first is going to give me + + align:start position:0% +subtree first is going to give me + + + align:start position:0% +subtree first is going to give me +the successor these are all kind of + + align:start position:0% +the successor these are all kind of + + + align:start position:0% +the successor these are all kind of +parallel um + + align:start position:0% +parallel um + + + align:start position:0% +parallel um +we're in the case now where our node has + + align:start position:0% +we're in the case now where our node has + + + align:start position:0% +we're in the case now where our node has +a right child + + align:start position:0% +a right child + + + align:start position:0% +a right child +and then successor tells us where the + + align:start position:0% +and then successor tells us where the + + + align:start position:0% +and then successor tells us where the +successor is it is the first + + align:start position:0% +successor is it is the first + + + align:start position:0% +successor is it is the first +node which is the leftmost descendant in + + align:start position:0% +node which is the leftmost descendant in + + + align:start position:0% +node which is the leftmost descendant in +the + + align:start position:0% +the + + + align:start position:0% +the +right subtree of the node okay a lot of + + align:start position:0% +right subtree of the node okay a lot of + + + align:start position:0% +right subtree of the node okay a lot of +pointers to follow in that sentence but + + align:start position:0% +pointers to follow in that sentence but + + + align:start position:0% +pointers to follow in that sentence but +it's + + align:start position:0% +it's + + + align:start position:0% +it's +clear in the picture so this + + align:start position:0% +clear in the picture so this + + + align:start position:0% +clear in the picture so this +in this case we had node and there was + + align:start position:0% +in this case we had node and there was + + + align:start position:0% +in this case we had node and there was +no right child so we just added + + align:start position:0% +no right child so we just added + + + align:start position:0% +no right child so we just added +new to be its right child okay in the + + align:start position:0% +new to be its right child okay in the + + + align:start position:0% +new to be its right child okay in the +other case + + align:start position:0% +other case + + + align:start position:0% +other case +we had a right child so here is node + + align:start position:0% +we had a right child so here is node + + + align:start position:0% +we had a right child so here is node +there's uh there's this node here + + align:start position:0% +there's uh there's this node here + + + align:start position:0% +there's uh there's this node here +node.right + + align:start position:0% +node.right + + + align:start position:0% +node.right +which now we're supposing exists + + align:start position:0% + + + + align:start position:0% + +and it defines a whole subtree there's + + align:start position:0% +and it defines a whole subtree there's + + + align:start position:0% +and it defines a whole subtree there's +this one + + align:start position:0% +this one + + + align:start position:0% +this one +which is the first node in the traversal + + align:start position:0% +which is the first node in the traversal + + + align:start position:0% +which is the first node in the traversal +order of the subtree also known as the + + align:start position:0% +order of the subtree also known as the + + + align:start position:0% +order of the subtree also known as the +successor of node + + align:start position:0% +successor of node + + + align:start position:0% +successor of node +so i'll call this successor + + align:start position:0% + + + + align:start position:0% + +of node in the current traversal order + + align:start position:0% +of node in the current traversal order + + + align:start position:0% +of node in the current traversal order +but of course we'd like to make + + align:start position:0% +but of course we'd like to make + + + align:start position:0% +but of course we'd like to make +new the new successor of the node so + + align:start position:0% +new the new successor of the node so + + + align:start position:0% +new the new successor of the node so +where does it go + + align:start position:0% +where does it go + + + align:start position:0% +where does it go +here + + align:start position:0% + + + + align:start position:0% + +we want to add it as a left child + + align:start position:0% +we want to add it as a left child + + + align:start position:0% +we want to add it as a left child +to the old successor + + align:start position:0% + + + + align:start position:0% + +okay so put uh + + align:start position:0% +okay so put uh + + + align:start position:0% +okay so put uh +node as + + align:start position:0% + + + + align:start position:0% + +so take the successor and if you look at + + align:start position:0% +so take the successor and if you look at + + + align:start position:0% +so take the successor and if you look at +the code for successor we're in this + + align:start position:0% +the code for successor we're in this + + + align:start position:0% +the code for successor we're in this +case so we know it will just call + + align:start position:0% +case so we know it will just call + + + align:start position:0% +case so we know it will just call +subtree first of node.right and remember + + align:start position:0% +subtree first of node.right and remember + + + align:start position:0% +subtree first of node.right and remember +subtree first + + align:start position:0% +subtree first + + + align:start position:0% +subtree first +went left as much as it possibly could + + align:start position:0% +went left as much as it possibly could + + + align:start position:0% +went left as much as it possibly could +so what that means is this successor + + align:start position:0% +so what that means is this successor + + + align:start position:0% +so what that means is this successor +node is guaranteed to not + + align:start position:0% +node is guaranteed to not + + + align:start position:0% +node is guaranteed to not +have a left child right because it was + + align:start position:0% +have a left child right because it was + + + align:start position:0% +have a left child right because it was +defined by going right once and then + + align:start position:0% +defined by going right once and then + + + align:start position:0% +defined by going right once and then +going left as much as you could + + align:start position:0% +going left as much as you could + + + align:start position:0% +going left as much as you could +so there's no more left which means we + + align:start position:0% +so there's no more left which means we + + + align:start position:0% +so there's no more left which means we +can make one more left + + align:start position:0% +can make one more left + + + align:start position:0% +can make one more left +just add new there and we're done + + align:start position:0% +just add new there and we're done + + + align:start position:0% +just add new there and we're done +now if you look at the traversal order + + align:start position:0% +now if you look at the traversal order + + + align:start position:0% +now if you look at the traversal order +it will be node then new + + align:start position:0% +it will be node then new + + + align:start position:0% +it will be node then new +then the old successor and then the rest + + align:start position:0% +then the old successor and then the rest + + + align:start position:0% +then the old successor and then the rest +of that subtree + + align:start position:0% +of that subtree + + + align:start position:0% +of that subtree +okay it's kind of cool in all cases + + align:start position:0% +okay it's kind of cool in all cases + + + align:start position:0% +okay it's kind of cool in all cases +uh i mean this was constant time + + align:start position:0% +uh i mean this was constant time + + + align:start position:0% +uh i mean this was constant time +here we spent constant time after we + + align:start position:0% +here we spent constant time after we + + + align:start position:0% +here we spent constant time after we +called successor successor costs order h + + align:start position:0% +called successor successor costs order h + + + align:start position:0% +called successor successor costs order h +time + + align:start position:0% +time + + + align:start position:0% +time +so this is order h + + align:start position:0% + + + + align:start position:0% + +new new okay + + align:start position:0% +new new okay + + + align:start position:0% +new new okay +put new there + + align:start position:0% + + + + align:start position:0% + +clear okay that was insertion + + align:start position:0% +clear okay that was insertion + + + align:start position:0% +clear okay that was insertion +let's do deletion + + align:start position:0% + + + + align:start position:0% + +get the spec right and the example + + align:start position:0% + + + + align:start position:0% + +all of these are going to have two cases + + align:start position:0% +all of these are going to have two cases + + + align:start position:0% +all of these are going to have two cases +uh so let me + + align:start position:0% +uh so let me + + + align:start position:0% +uh so let me +oh i didn't update so now h is after a + + align:start position:0% +oh i didn't update so now h is after a + + + align:start position:0% +oh i didn't update so now h is after a +so it should be like this + + align:start position:0% +so it should be like this + + + align:start position:0% +so it should be like this +you can check the new traverse order of + + align:start position:0% +you can check the new traverse order of + + + align:start position:0% +you can check the new traverse order of +this tree is exactly that + + align:start position:0% + + + + align:start position:0% + +next i'm going to do a couple of + + align:start position:0% +next i'm going to do a couple of + + + align:start position:0% +next i'm going to do a couple of +deletions + + align:start position:0% +deletions + + + align:start position:0% +deletions +let's delete + + align:start position:0% + + + + align:start position:0% + +f first and then we're going to + + align:start position:0% +f first and then we're going to + + + align:start position:0% +f first and then we're going to +well this is + + align:start position:0% + + + + align:start position:0% + +confusing + + align:start position:0% + + + + align:start position:0% + +and then we're going to delete a so + + align:start position:0% +and then we're going to delete a so + + + align:start position:0% +and then we're going to delete a so +where's f we're supposing we're given a + + align:start position:0% +where's f we're supposing we're given a + + + align:start position:0% +where's f we're supposing we're given a +pointer to f this node + + align:start position:0% +pointer to f this node + + + align:start position:0% +pointer to f this node +well it's a leaf so if i want to delete + + align:start position:0% +well it's a leaf so if i want to delete + + + align:start position:0% +well it's a leaf so if i want to delete +it i just erase it + + align:start position:0% +it i just erase it + + + align:start position:0% +it i just erase it +easy leaves are easy to delete there's + + align:start position:0% +easy leaves are easy to delete there's + + + align:start position:0% +easy leaves are easy to delete there's +no work to do so what that means is i'm + + align:start position:0% +no work to do so what that means is i'm + + + align:start position:0% +no work to do so what that means is i'm +removing the pointer from d + + align:start position:0% +removing the pointer from d + + + align:start position:0% +removing the pointer from d +to f okay we just erase that guy + + align:start position:0% +to f okay we just erase that guy + + + align:start position:0% +to f okay we just erase that guy +uh okay now here's a trickier one + + align:start position:0% +uh okay now here's a trickier one + + + align:start position:0% +uh okay now here's a trickier one +suppose i want to delete the root of the + + align:start position:0% +suppose i want to delete the root of the + + + align:start position:0% +suppose i want to delete the root of the +tree this is kind of + + align:start position:0% +tree this is kind of + + + align:start position:0% +tree this is kind of +the hardest case but in general it would + + align:start position:0% +the hardest case but in general it would + + + align:start position:0% +the hardest case but in general it would +be somewhere in between leaf and root + + align:start position:0% +be somewhere in between leaf and root + + + align:start position:0% +be somewhere in between leaf and root +so if i want to delete a if i just + + align:start position:0% +so if i want to delete a if i just + + + align:start position:0% +so if i want to delete a if i just +erased it then suddenly there are these + + align:start position:0% +erased it then suddenly there are these + + + align:start position:0% +erased it then suddenly there are these +pointers to nowhere + + align:start position:0% +pointers to nowhere + + + align:start position:0% +pointers to nowhere +and i disconnect the tree into two parts + + align:start position:0% +and i disconnect the tree into two parts + + + align:start position:0% +and i disconnect the tree into two parts +i don't want to do that i need to keep + + align:start position:0% +i don't want to do that i need to keep + + + align:start position:0% +i don't want to do that i need to keep +my tree connected + + align:start position:0% +my tree connected + + + align:start position:0% +my tree connected +so i'm going to play this trick + + align:start position:0% +so i'm going to play this trick + + + align:start position:0% +so i'm going to play this trick +which is i forget if i use successor or + + align:start position:0% +which is i forget if i use successor or + + + align:start position:0% +which is i forget if i use successor or +predecessor + + align:start position:0% +predecessor + + + align:start position:0% +predecessor +predecessor + + align:start position:0% + + + + align:start position:0% + +so i'm going to uh look at a we already + + align:start position:0% +so i'm going to uh look at a we already + + + align:start position:0% +so i'm going to uh look at a we already +have defined successor and + + align:start position:0% +have defined successor and + + + align:start position:0% +have defined successor and +there by predecessor so i'm going to + + align:start position:0% +there by predecessor so i'm going to + + + align:start position:0% +there by predecessor so i'm going to +look at the predecessor of a + + align:start position:0% +look at the predecessor of a + + + align:start position:0% +look at the predecessor of a +which is e you can check that here the + + align:start position:0% +which is e you can check that here the + + + align:start position:0% +which is e you can check that here the +one before + + align:start position:0% +one before + + + align:start position:0% +one before +a is e this is in the left subtree + + align:start position:0% +a is e this is in the left subtree + + + align:start position:0% +a is e this is in the left subtree +uh find me the rightmost item keep going + + align:start position:0% +uh find me the rightmost item keep going + + + align:start position:0% +uh find me the rightmost item keep going +right until i can't that's e + + align:start position:0% +right until i can't that's e + + + align:start position:0% +right until i can't that's e +so now these guys are adjacent in the + + align:start position:0% +so now these guys are adjacent in the + + + align:start position:0% +so now these guys are adjacent in the +order and i'm about to remove a from the + + align:start position:0% +order and i'm about to remove a from the + + + align:start position:0% +order and i'm about to remove a from the +order + + align:start position:0% +order + + + align:start position:0% +order +so i can momentarily cheat and swap + + align:start position:0% +so i can momentarily cheat and swap + + + align:start position:0% +so i can momentarily cheat and swap +their labels + + align:start position:0% +their labels + + + align:start position:0% +their labels +i'm going to erase a and e here and put + + align:start position:0% +i'm going to erase a and e here and put + + + align:start position:0% +i'm going to erase a and e here and put +e + + align:start position:0% +e + + + align:start position:0% +e +after a why because it moves a + + align:start position:0% +after a why because it moves a + + + align:start position:0% +after a why because it moves a +down in the tree and if i get to the + + align:start position:0% +down in the tree and if i get to the + + + align:start position:0% +down in the tree and if i get to the +leaf i'm done + + align:start position:0% +leaf i'm done + + + align:start position:0% +leaf i'm done +so i'm not quite done because this is + + align:start position:0% +so i'm not quite done because this is + + + align:start position:0% +so i'm not quite done because this is +not a leaf so again i look at a's + + align:start position:0% +not a leaf so again i look at a's + + + align:start position:0% +not a leaf so again i look at a's +predecessor it's now + + align:start position:0% +predecessor it's now + + + align:start position:0% +predecessor it's now +g predecessor + + align:start position:0% +g predecessor + + + align:start position:0% +g predecessor +we hope is always in the uh + + align:start position:0% +we hope is always in the uh + + + align:start position:0% +we hope is always in the uh +farther down in the tree and then i swap + + align:start position:0% +farther down in the tree and then i swap + + + align:start position:0% +farther down in the tree and then i swap +a with g + + align:start position:0% + + + + align:start position:0% + +okay i have preserved the traversal + + align:start position:0% +okay i have preserved the traversal + + + align:start position:0% +okay i have preserved the traversal +order except where a + + align:start position:0% +order except where a + + + align:start position:0% +order except where a +falls just by moving a earlier in the + + align:start position:0% +falls just by moving a earlier in the + + + align:start position:0% +falls just by moving a earlier in the +order here + + align:start position:0% +order here + + + align:start position:0% +order here +and now a is a leaf and i can erase it + + align:start position:0% +and now a is a leaf and i can erase it + + + align:start position:0% +and now a is a leaf and i can erase it +okay so that's what we're going to + + align:start position:0% +okay so that's what we're going to + + + align:start position:0% +okay so that's what we're going to +follow now in actuality it's a little + + align:start position:0% +follow now in actuality it's a little + + + align:start position:0% +follow now in actuality it's a little +tricky sometimes we need to use + + align:start position:0% +tricky sometimes we need to use + + + align:start position:0% +tricky sometimes we need to use +predecessors sometimes we need to use + + align:start position:0% +predecessors sometimes we need to use + + + align:start position:0% +predecessors sometimes we need to use +successor okay so the cases are + + align:start position:0% +successor okay so the cases are + + + align:start position:0% +successor okay so the cases are +if the node is a leaf just + + align:start position:0% +if the node is a leaf just + + + align:start position:0% +if the node is a leaf just +detach it from the parent easy + + align:start position:0% + + + + align:start position:0% + +that's sort of our base case in the + + align:start position:0% +that's sort of our base case in the + + + align:start position:0% +that's sort of our base case in the +recursion otherwise + + align:start position:0% + + + + align:start position:0% + +there are two cases if + + align:start position:0% +there are two cases if + + + align:start position:0% +there are two cases if +so if we're not a leaf that means we + + align:start position:0% +so if we're not a leaf that means we + + + align:start position:0% +so if we're not a leaf that means we +have + + align:start position:0% +have + + + align:start position:0% +have +a left child or a right child or both + + align:start position:0% +a left child or a right child or both + + + align:start position:0% +a left child or a right child or both +both is going to be the easy case + + align:start position:0% +both is going to be the easy case + + + align:start position:0% +both is going to be the easy case +but in general i have either there's a + + align:start position:0% +but in general i have either there's a + + + align:start position:0% +but in general i have either there's a +left child + + align:start position:0% +left child + + + align:start position:0% +left child +or there's a right child in either case + + align:start position:0% +or there's a right child in either case + + + align:start position:0% +or there's a right child in either case +i'm going to be happy so i don't need a + + align:start position:0% +i'm going to be happy so i don't need a + + + align:start position:0% +i'm going to be happy so i don't need a +both case + + align:start position:0% +both case + + + align:start position:0% +both case +uh okay so what do i do in if i have a + + align:start position:0% +uh okay so what do i do in if i have a + + + align:start position:0% +uh okay so what do i do in if i have a +left child + + align:start position:0% +left child + + + align:start position:0% +left child +that guarantees to me that if the node's + + align:start position:0% +that guarantees to me that if the node's + + + align:start position:0% +that guarantees to me that if the node's +predecessor + + align:start position:0% +predecessor + + + align:start position:0% +predecessor +is inside that left sub-tree which means + + align:start position:0% +is inside that left sub-tree which means + + + align:start position:0% +is inside that left sub-tree which means +it's lower in the tree + + align:start position:0% +it's lower in the tree + + + align:start position:0% +it's lower in the tree +if i didn't have a left child the + + align:start position:0% +if i didn't have a left child the + + + align:start position:0% +if i didn't have a left child the +predecessor would actually be higher in + + align:start position:0% +predecessor would actually be higher in + + + align:start position:0% +predecessor would actually be higher in +the tree and i don't want to go higher + + align:start position:0% +the tree and i don't want to go higher + + + align:start position:0% +the tree and i don't want to go higher +okay so if i have a left child i know + + align:start position:0% +okay so if i have a left child i know + + + align:start position:0% +okay so if i have a left child i know +the predecessor is lower + + align:start position:0% +the predecessor is lower + + + align:start position:0% +the predecessor is lower +and so i'm going to swap + + align:start position:0% +and so i'm going to swap + + + align:start position:0% +and so i'm going to swap +my item the contents of my node + + align:start position:0% +my item the contents of my node + + + align:start position:0% +my item the contents of my node +with my predecessor's item + + align:start position:0% +with my predecessor's item + + + align:start position:0% +with my predecessor's item +and then i'm going to recursively delete + + align:start position:0% +and then i'm going to recursively delete + + + align:start position:0% +and then i'm going to recursively delete +the predecessor okay that's the case + + align:start position:0% +the predecessor okay that's the case + + + align:start position:0% +the predecessor okay that's the case +that we looked at in this code + + align:start position:0% +that we looked at in this code + + + align:start position:0% +that we looked at in this code +in this example because we always had a + + align:start position:0% +in this example because we always had a + + + align:start position:0% +in this example because we always had a +left child if we have a right child but + + align:start position:0% +left child if we have a right child but + + + align:start position:0% +left child if we have a right child but +no left child we just do the reverse we + + align:start position:0% +no left child we just do the reverse we + + + align:start position:0% +no left child we just do the reverse we +swap with our successors + + align:start position:0% +swap with our successors + + + align:start position:0% +swap with our successors +item and then delete the successor in + + align:start position:0% +item and then delete the successor in + + + align:start position:0% +item and then delete the successor in +either case we're going down + + align:start position:0% +either case we're going down + + + align:start position:0% +either case we're going down +and so if we start at some node like the + + align:start position:0% +and so if we start at some node like the + + + align:start position:0% +and so if we start at some node like the +route every time we do this operation + + align:start position:0% +route every time we do this operation + + + align:start position:0% +route every time we do this operation +we're walking down and then we're + + align:start position:0% +we're walking down and then we're + + + align:start position:0% +we're walking down and then we're +walking down + + align:start position:0% +walking down + + + align:start position:0% +walking down +and in general we'll keep walking down + + align:start position:0% +and in general we'll keep walking down + + + align:start position:0% +and in general we'll keep walking down +resuming where we left off which means + + align:start position:0% +resuming where we left off which means + + + align:start position:0% +resuming where we left off which means +total amount of time we spend is + + align:start position:0% +total amount of time we spend is + + + align:start position:0% +total amount of time we spend is +proportional to + + align:start position:0% +proportional to + + + align:start position:0% +proportional to +the height of the tree in the worst case + + align:start position:0% + + + + align:start position:0% + +question + + align:start position:0% +question + + + align:start position:0% +question +right so e didn't used to have a right + + align:start position:0% +right so e didn't used to have a right + + + align:start position:0% +right so e didn't used to have a right +child so we're changing identities of + + align:start position:0% +child so we're changing identities of + + + align:start position:0% +child so we're changing identities of +nodes when we do this + + align:start position:0% +nodes when we do this + + + align:start position:0% +nodes when we do this +because we uh this that we didn't + + align:start position:0% +because we uh this that we didn't + + + align:start position:0% +because we uh this that we didn't +actually move this + + align:start position:0% +actually move this + + + align:start position:0% +actually move this +circle the circle stayed in place and + + align:start position:0% +circle the circle stayed in place and + + + align:start position:0% +circle the circle stayed in place and +what we changed was the item that was + + align:start position:0% +what we changed was the item that was + + + align:start position:0% +what we changed was the item that was +stored in that circle + + align:start position:0% +stored in that circle + + + align:start position:0% +stored in that circle +so whether you call this node e or a + + align:start position:0% +so whether you call this node e or a + + + align:start position:0% +so whether you call this node e or a +it doesn't really matter it is just the + + align:start position:0% +it doesn't really matter it is just the + + + align:start position:0% +it doesn't really matter it is just the +root note + + align:start position:0% +root note + + + align:start position:0% +root note +okay so we're gonna play a lot of these + + align:start position:0% +okay so we're gonna play a lot of these + + + align:start position:0% +okay so we're gonna play a lot of these +tricks of moving the items around so far + + align:start position:0% +tricks of moving the items around so far + + + align:start position:0% +tricks of moving the items around so far +we hadn't been doing that we've just + + align:start position:0% +we hadn't been doing that we've just + + + align:start position:0% +we hadn't been doing that we've just +been creating + + align:start position:0% +been creating + + + align:start position:0% +been creating +nodes and placing them somewhere but now + + align:start position:0% +nodes and placing them somewhere but now + + + align:start position:0% +nodes and placing them somewhere but now +we're + + align:start position:0% +we're + + + align:start position:0% +we're +in this delete operation is the first + + align:start position:0% +in this delete operation is the first + + + align:start position:0% +in this delete operation is the first +time where we're changing what's stored + + align:start position:0% +time where we're changing what's stored + + + align:start position:0% +time where we're changing what's stored +in the nodes + + align:start position:0% +in the nodes + + + align:start position:0% +in the nodes +but we still can define the traversal + + align:start position:0% +but we still can define the traversal + + + align:start position:0% +but we still can define the traversal +order right the traverse order of this + + align:start position:0% +order right the traverse order of this + + + align:start position:0% +order right the traverse order of this +tree is dbgehc + + align:start position:0% +tree is dbgehc + + + align:start position:0% +tree is dbgehc +which should be what we get here if i + + align:start position:0% +which should be what we get here if i + + + align:start position:0% +which should be what we get here if i +delete f and + + align:start position:0% +delete f and + + + align:start position:0% +delete f and +a + + align:start position:0% + + + + align:start position:0% + +and sorry can f + + align:start position:0% +and sorry can f + + + align:start position:0% +and sorry can f +trees will not preserve connections + + align:start position:0% +trees will not preserve connections + + + align:start position:0% +trees will not preserve connections +that's just the name of the game we are + + align:start position:0% +that's just the name of the game we are + + + align:start position:0% +that's just the name of the game we are +we have to allow this otherwise we can't + + align:start position:0% +we have to allow this otherwise we can't + + + align:start position:0% +we have to allow this otherwise we can't +do anything that's the short + + align:start position:0% +do anything that's the short + + + align:start position:0% +do anything that's the short +version okay okay in the last few + + align:start position:0% +version okay okay in the last few + + + align:start position:0% +version okay okay in the last few +minutes let me talk about how we take + + align:start position:0% +minutes let me talk about how we take + + + align:start position:0% +minutes let me talk about how we take +these trees and implement a set + + align:start position:0% +these trees and implement a set + + + align:start position:0% +these trees and implement a set +or sequence okay i've already alluded to + + align:start position:0% +or sequence okay i've already alluded to + + + align:start position:0% +or sequence okay i've already alluded to +this + + align:start position:0% + + + + align:start position:0% + +so for a sequence + + align:start position:0% + + + + align:start position:0% + +we just make the traversal order + + align:start position:0% + + + + align:start position:0% + +equal to the the order that we're trying + + align:start position:0% +equal to the the order that we're trying + + + align:start position:0% +equal to the the order that we're trying +to represent + + align:start position:0% +to represent + + + align:start position:0% +to represent +the sequence order + + align:start position:0% +the sequence order + + + align:start position:0% +the sequence order +and if we're trying to source set items + + align:start position:0% +and if we're trying to source set items + + + align:start position:0% +and if we're trying to source set items +with keys we're going to make the + + align:start position:0% +with keys we're going to make the + + + align:start position:0% +with keys we're going to make the +traversal order + + align:start position:0% + + + + align:start position:0% + +equal to ordered by increasing key + + align:start position:0% +equal to ordered by increasing key + + + align:start position:0% +equal to ordered by increasing key +increasing item + + align:start position:0% +increasing item + + + align:start position:0% +increasing item +key + + align:start position:0% + + + + align:start position:0% + +some sense that's it but then we need to + + align:start position:0% +some sense that's it but then we need to + + + align:start position:0% +some sense that's it but then we need to +think about how do we implement + + align:start position:0% +think about how do we implement + + + align:start position:0% +think about how do we implement +all of these operations so maybe most + + align:start position:0% +all of these operations so maybe most + + + align:start position:0% +all of these operations so maybe most +enlightening is for starters is + + align:start position:0% +enlightening is for starters is + + + align:start position:0% +enlightening is for starters is +finding a key in a tree + + align:start position:0% +finding a key in a tree + + + align:start position:0% +finding a key in a tree +so this is going to correspond to binary + + align:start position:0% +so this is going to correspond to binary + + + align:start position:0% +so this is going to correspond to binary +search + + align:start position:0% +search + + + align:start position:0% +search +if i'm searching for a key let's say i'm + + align:start position:0% +if i'm searching for a key let's say i'm + + + align:start position:0% +if i'm searching for a key let's say i'm +searching for + + align:start position:0% +searching for + + + align:start position:0% +searching for +g's key and i know this + + align:start position:0% +g's key and i know this + + + align:start position:0% +g's key and i know this +may be hard in this example maybe i'll + + align:start position:0% +may be hard in this example maybe i'll + + + align:start position:0% +may be hard in this example maybe i'll +replace these all with numbers + + align:start position:0% +replace these all with numbers + + + align:start position:0% +replace these all with numbers +so i can think about key values + + align:start position:0% +so i can think about key values + + + align:start position:0% +so i can think about key values +okay so let's say 1 7 + + align:start position:0% +okay so let's say 1 7 + + + align:start position:0% +okay so let's say 1 7 +12 17 + + align:start position:0% +12 17 + + + align:start position:0% +12 17 +19 and 23. + + align:start position:0% +19 and 23. + + + align:start position:0% +19 and 23. +this is now in key order if you think of + + align:start position:0% +this is now in key order if you think of + + + align:start position:0% +this is now in key order if you think of +the traversal order + + align:start position:0% +the traversal order + + + align:start position:0% +the traversal order +the property is that all the keys in the + + align:start position:0% +the property is that all the keys in the + + + align:start position:0% +the property is that all the keys in the +left subtree of the root + + align:start position:0% +left subtree of the root + + + align:start position:0% +left subtree of the root +are less than the root and the root is + + align:start position:0% +are less than the root and the root is + + + align:start position:0% +are less than the root and the root is +less than all the keys in the right + + align:start position:0% +less than all the keys in the right + + + align:start position:0% +less than all the keys in the right +subtree and recursively all the way down + + align:start position:0% +subtree and recursively all the way down + + + align:start position:0% +subtree and recursively all the way down +this is something called the + + align:start position:0% +this is something called the + + + align:start position:0% +this is something called the +binary search tree property bst property + + align:start position:0% +binary search tree property bst property + + + align:start position:0% +binary search tree property bst property +these here we're calling them binary + + align:start position:0% +these here we're calling them binary + + + align:start position:0% +these here we're calling them binary +tree + + align:start position:0% +tree + + + align:start position:0% +tree +sets or set binary trees but they're + + align:start position:0% +sets or set binary trees but they're + + + align:start position:0% +sets or set binary trees but they're +also known in the literature as binary + + align:start position:0% +also known in the literature as binary + + + align:start position:0% +also known in the literature as binary +search trees term you may have heard + + align:start position:0% +search trees term you may have heard + + + align:start position:0% +search trees term you may have heard +before + + align:start position:0% +before + + + align:start position:0% +before +so this is a special case of what we're + + align:start position:0% +so this is a special case of what we're + + + align:start position:0% +so this is a special case of what we're +doing where we're storing the keys in + + align:start position:0% +doing where we're storing the keys in + + + align:start position:0% +doing where we're storing the keys in +order + + align:start position:0% +order + + + align:start position:0% +order +and then if i want to search for a key + + align:start position:0% +and then if i want to search for a key + + + align:start position:0% +and then if i want to search for a key +like uh 13 + + align:start position:0% +like uh 13 + + + align:start position:0% +like uh 13 +i compare that key with the root i see + + align:start position:0% +i compare that key with the root i see + + + align:start position:0% +i compare that key with the root i see +oh it's not + + align:start position:0% +oh it's not + + + align:start position:0% +oh it's not +equal and it's to the left because it's + + align:start position:0% +equal and it's to the left because it's + + + align:start position:0% +equal and it's to the left because it's +less than + + align:start position:0% +less than + + + align:start position:0% +less than +17. so 13 is left of here 13 is right of + + align:start position:0% +17. so 13 is left of here 13 is right of + + + align:start position:0% +17. so 13 is left of here 13 is right of + + align:start position:0% + + + align:start position:0% +13 is right of 12 and so i know that + + align:start position:0% +13 is right of 12 and so i know that + + + align:start position:0% +13 is right of 12 and so i know that +this is where 13 would belong + + align:start position:0% +this is where 13 would belong + + + align:start position:0% +this is where 13 would belong +but there's no right child there and so + + align:start position:0% +but there's no right child there and so + + + align:start position:0% +but there's no right child there and so +i know in find i just returned nothing + + align:start position:0% +i know in find i just returned nothing + + + align:start position:0% +i know in find i just returned nothing +if i was doing find previous i would + + align:start position:0% +if i was doing find previous i would + + + align:start position:0% +if i was doing find previous i would +return this note + + align:start position:0% +return this note + + + align:start position:0% +return this note +because i have tried to go to the right + + align:start position:0% +because i have tried to go to the right + + + align:start position:0% +because i have tried to go to the right +the last time before i fell off the tree + + align:start position:0% +the last time before i fell off the tree + + + align:start position:0% +the last time before i fell off the tree +i was trying to go to the right and + + align:start position:0% +i was trying to go to the right and + + + align:start position:0% +i was trying to go to the right and +therefore that last note i had was the + + align:start position:0% +therefore that last note i had was the + + + align:start position:0% +therefore that last note i had was the +previous item if i was trying to define + + align:start position:0% +previous item if i was trying to define + + + align:start position:0% +previous item if i was trying to define +next what would i do i would just take + + align:start position:0% +next what would i do i would just take + + + align:start position:0% +next what would i do i would just take +this node and compute its successor + + align:start position:0% +this node and compute its successor + + + align:start position:0% +this node and compute its successor +which we already know how to do and that + + align:start position:0% +which we already know how to do and that + + + align:start position:0% +which we already know how to do and that +happens to be the root + + align:start position:0% +happens to be the root + + + align:start position:0% +happens to be the root +okay so now i can do these inexact + + align:start position:0% +okay so now i can do these inexact + + + align:start position:0% +okay so now i can do these inexact +searches when i do find previous and + + align:start position:0% +searches when i do find previous and + + + align:start position:0% +searches when i do find previous and +find next + + align:start position:0% +find next + + + align:start position:0% +find next +when i fall off the tree i find either + + align:start position:0% +when i fall off the tree i find either + + + align:start position:0% +when i fall off the tree i find either +the previous or the next + + align:start position:0% +the previous or the next + + + align:start position:0% +the previous or the next +and then with predecessor or successor i + + align:start position:0% +and then with predecessor or successor i + + + align:start position:0% +and then with predecessor or successor i +can find the other one + + align:start position:0% +can find the other one + + + align:start position:0% +can find the other one +okay so that's how we can do find and + + align:start position:0% +okay so that's how we can do find and + + + align:start position:0% +okay so that's how we can do find and +find previous + + align:start position:0% +find previous + + + align:start position:0% +find previous +and find next to do + + align:start position:0% +and find next to do + + + align:start position:0% +and find next to do +uh sequences we need a little bit more + + align:start position:0% +uh sequences we need a little bit more + + + align:start position:0% +uh sequences we need a little bit more +work + + align:start position:0% +work + + + align:start position:0% +work +we'll do that next time + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/7Cvytz8rLLo.txt b/7Cvytz8rLLo.txt new file mode 100644 index 0000000000000000000000000000000000000000..05f43f2ae36f7996c9985e5ee360afe9a6a549f4 --- /dev/null +++ b/7Cvytz8rLLo.txt @@ -0,0 +1,3971 @@ +align:start position:0% + +all + + align:start position:0% +all + + + align:start position:0% +all +right I'd like to talk about this next + + align:start position:0% +right I'd like to talk about this next + + + align:start position:0% +right I'd like to talk about this next +project in + + align:start position:0% +project in + + + align:start position:0% +project in +um about four different + + align:start position:0% +um about four different + + + align:start position:0% +um about four different +ways and I'm going to break it down and + + align:start position:0% +ways and I'm going to break it down and + + + align:start position:0% +ways and I'm going to break it down and +you might take some notes if you + + align:start position:0% +you might take some notes if you + + + align:start position:0% +you might take some notes if you +would uh the first will be about the + + align:start position:0% +would uh the first will be about the + + + align:start position:0% +would uh the first will be about the +site the second is about the + + align:start position:0% +site the second is about the + + + align:start position:0% +site the second is about the +program uh the third is s of what we're + + align:start position:0% +program uh the third is s of what we're + + + align:start position:0% +program uh the third is s of what we're +doing in terms of the architecture the + + align:start position:0% +doing in terms of the architecture the + + + align:start position:0% +doing in terms of the architecture the +space the + + align:start position:0% +space the + + + align:start position:0% +space the +determinance and the fourth is this + + align:start position:0% +determinance and the fourth is this + + + align:start position:0% +determinance and the fourth is this +issue of nature if we call it that quote + + align:start position:0% +issue of nature if we call it that quote + + + align:start position:0% +issue of nature if we call it that quote +in the city so I'm going to start with + + align:start position:0% +in the city so I'm going to start with + + + align:start position:0% +in the city so I'm going to start with +the site Jen has uh for you and she'll + + align:start position:0% +the site Jen has uh for you and she'll + + + align:start position:0% +the site Jen has uh for you and she'll +be here a copy of of the section at 16th + + align:start position:0% +be here a copy of of the section at 16th + + + align:start position:0% +be here a copy of of the section at 16th +scale of the site this photo montage of + + align:start position:0% +scale of the site this photo montage of + + + align:start position:0% +scale of the site this photo montage of +the site a 16th scale plan and an NA + + align:start position:0% +the site a 16th scale plan and an NA + + + align:start position:0% +the site a 16th scale plan and an NA +scale + + align:start position:0% +scale + + + align:start position:0% +scale +plan uh she should have when she arrives + + align:start position:0% +plan uh she should have when she arrives + + + align:start position:0% +plan uh she should have when she arrives +copies of everything of + + align:start position:0% +copies of everything of + + + align:start position:0% +copies of everything of +this the site is no U stranger to you + + align:start position:0% +this the site is no U stranger to you + + + align:start position:0% +this the site is no U stranger to you +you do know it uh some of you + + align:start position:0% +you do know it uh some of you + + + align:start position:0% +you do know it uh some of you +intimately uh sorry well here and + + align:start position:0% +intimately uh sorry well here and + + + align:start position:0% +intimately uh sorry well here and +certainly these two guys um and many of + + align:start position:0% +certainly these two guys um and many of + + + align:start position:0% +certainly these two guys um and many of +them as you know looking into + + align:start position:0% +them as you know looking into + + + align:start position:0% +them as you know looking into +it the site is roughly an area that is + + align:start position:0% +it the site is roughly an area that is + + + align:start position:0% +it the site is roughly an area that is +like + + align:start position:0% + + + + align:start position:0% + +this and is + + align:start position:0% +this and is + + + align:start position:0% +this and is +a interesting site I won't call it + + align:start position:0% +a interesting site I won't call it + + + align:start position:0% +a interesting site I won't call it +difficult but it's an interesting site + + align:start position:0% +difficult but it's an interesting site + + + align:start position:0% +difficult but it's an interesting site +and there are some ways of describing + + align:start position:0% +and there are some ways of describing + + + align:start position:0% +and there are some ways of describing +it for the purposes of this project we + + align:start position:0% +it for the purposes of this project we + + + align:start position:0% +it for the purposes of this project we +are considering it to be completely + + align:start position:0% +are considering it to be completely + + + align:start position:0% +are considering it to be completely +flat it's it's not entirely flat but + + align:start position:0% +flat it's it's not entirely flat but + + + align:start position:0% +flat it's it's not entirely flat but +it's close enough to being + + align:start position:0% +it's close enough to being + + + align:start position:0% +it's close enough to being +flat there is a driveway that goes down + + align:start position:0% +flat there is a driveway that goes down + + + align:start position:0% +flat there is a driveway that goes down +to a garage here that we're considering + + align:start position:0% +to a garage here that we're considering + + + align:start position:0% +to a garage here that we're considering +isn't there it shouldn't have been there + + align:start position:0% +isn't there it shouldn't have been there + + + align:start position:0% +isn't there it shouldn't have been there +in the first place actually it's + + align:start position:0% +in the first place actually it's + + + align:start position:0% +in the first place actually it's +illegal but we're considering it's not + + align:start position:0% +illegal but we're considering it's not + + + align:start position:0% +illegal but we're considering it's not +there there is a and you can see on here + + align:start position:0% +there there is a and you can see on here + + + align:start position:0% +there there is a and you can see on here +called a lane lands + + align:start position:0% +called a lane lands + + + align:start position:0% +called a lane lands +Court um which I probably would guess + + align:start position:0% +Court um which I probably would guess + + + align:start position:0% +Court um which I probably would guess +originally + + align:start position:0% +originally + + + align:start position:0% +originally +there was houses like this here and then + + align:start position:0% +there was houses like this here and then + + + align:start position:0% +there was houses like this here and then +houses like this + + align:start position:0% +houses like this + + + align:start position:0% +houses like this +here and the tunnel came along and + + align:start position:0% +here and the tunnel came along and + + + align:start position:0% +here and the tunnel came along and +blasted everything away because they + + align:start position:0% +blasted everything away because they + + + align:start position:0% +blasted everything away because they +probably had to dig underneath this to + + align:start position:0% +probably had to dig underneath this to + + + align:start position:0% +probably had to dig underneath this to +do this because this is where the I + + align:start position:0% +do this because this is where the I + + + align:start position:0% +do this because this is where the I +think the tunnel goes down so that's why + + align:start position:0% +think the tunnel goes down so that's why + + + align:start position:0% +think the tunnel goes down so that's why +it's like this but for the purpose of + + align:start position:0% +it's like this but for the purpose of + + + align:start position:0% +it's like this but for the purpose of +our project this is part of our of our + + align:start position:0% +our project this is part of our of our + + + align:start position:0% +our project this is part of our of our +site and this is also part of our site + + align:start position:0% +site and this is also part of our site + + + align:start position:0% +site and this is also part of our site +therefore we don't worry about cars + + align:start position:0% +therefore we don't worry about cars + + + align:start position:0% +therefore we don't worry about cars +going back through here they don't do it + + align:start position:0% +going back through here they don't do it + + + align:start position:0% +going back through here they don't do it +it + + align:start position:0% +it + + + align:start position:0% +it +now this is parking this is nothing and + + align:start position:0% +now this is parking this is nothing and + + + align:start position:0% +now this is parking this is nothing and +this is playground and we're just going + + align:start position:0% +this is playground and we're just going + + + align:start position:0% +this is playground and we're just going +to forget about the playground for the + + align:start position:0% +to forget about the playground for the + + + align:start position:0% +to forget about the playground for the +time being I know Felix that you may not + + align:start position:0% +time being I know Felix that you may not + + + align:start position:0% +time being I know Felix that you may not +like that but you can move it over to + + align:start position:0% +like that but you can move it over to + + + align:start position:0% +like that but you can move it over to +here which is a nice playground space or + + align:start position:0% +here which is a nice playground space or + + + align:start position:0% +here which is a nice playground space or +in incorporated into your so keep paring + + align:start position:0% +in incorporated into your so keep paring + + + align:start position:0% +in incorporated into your so keep paring +so that's the first point is that that + + align:start position:0% +so that's the first point is that that + + + align:start position:0% +so that's the first point is that that +is flat and the and the rways and the + + align:start position:0% +is flat and the and the rways and the + + + align:start position:0% +is flat and the and the rways and the +driveways you can keep I mean you uh you + + align:start position:0% +driveways you can keep I mean you uh you + + + align:start position:0% +driveways you can keep I mean you uh you +ignore there are are however some nice + + align:start position:0% +ignore there are are however some nice + + + align:start position:0% +ignore there are are however some nice +trees that you have to think + + align:start position:0% +trees that you have to think + + + align:start position:0% +trees that you have to think +about I think two but oh + + align:start position:0% +about I think two but oh + + + align:start position:0% +about I think two but oh +wait oh they don't look very nice on + + align:start position:0% +wait oh they don't look very nice on + + + align:start position:0% +wait oh they don't look very nice on +this oh no here they are yeah two + + align:start position:0% +this oh no here they are yeah two + + + align:start position:0% +this oh no here they are yeah two +there's one here didn't + + align:start position:0% +there's one here didn't + + + align:start position:0% +there's one here didn't +know oh this little building you don't + + align:start position:0% +know oh this little building you don't + + + align:start position:0% +know oh this little building you don't +worry about either it's not on here + + align:start position:0% +worry about either it's not on here + + + align:start position:0% +worry about either it's not on here +there's a little building here but + + align:start position:0% +there's a little building here but + + + align:start position:0% +there's a little building here but +forget + + align:start position:0% +forget + + + align:start position:0% +forget +that whenever in architecture you + + align:start position:0% +that whenever in architecture you + + + align:start position:0% +that whenever in architecture you +destroy a tree think about it very + + align:start position:0% +destroy a tree think about it very + + + align:start position:0% +destroy a tree think about it very +seriously you can now transplant trees + + align:start position:0% +seriously you can now transplant trees + + + align:start position:0% +seriously you can now transplant trees +but they're expensive um these are not + + align:start position:0% +but they're expensive um these are not + + + align:start position:0% +but they're expensive um these are not +mature trees by any means but they have + + align:start position:0% +mature trees by any means but they have + + + align:start position:0% +mature trees by any means but they have +had a life of 20 probably 25 years that + + align:start position:0% +had a life of 20 probably 25 years that + + + align:start position:0% +had a life of 20 probably 25 years that +doesn't mean you can't take + + align:start position:0% +doesn't mean you can't take + + + align:start position:0% +doesn't mean you can't take +them or relocate them but think about it + + align:start position:0% +them or relocate them but think about it + + + align:start position:0% +them or relocate them but think about it +before you + + align:start position:0% + + + + align:start position:0% + +do I have the following um criteria for + + align:start position:0% +do I have the following um criteria for + + + align:start position:0% +do I have the following um criteria for +you that this wall which has Windows on + + align:start position:0% +you that this wall which has Windows on + + + align:start position:0% +you that this wall which has Windows on +it you have to keep those windows + + align:start position:0% +it you have to keep those windows + + + align:start position:0% +it you have to keep those windows +and therefore somehow you got to get + + align:start position:0% +and therefore somehow you got to get + + + align:start position:0% +and therefore somehow you got to get +light + + align:start position:0% +light + + + align:start position:0% +light +into these + + align:start position:0% +into these + + + align:start position:0% +into these +guys however this one which has Windows + + align:start position:0% +guys however this one which has Windows + + + align:start position:0% +guys however this one which has Windows +on it you don't have to keep because in + + align:start position:0% +on it you don't have to keep because in + + + align:start position:0% +on it you don't have to keep because in +the Northend vocabulary it's on the + + align:start position:0% +the Northend vocabulary it's on the + + + align:start position:0% +the Northend vocabulary it's on the +corner but most of the time it does not + + align:start position:0% +corner but most of the time it does not + + + align:start position:0% +corner but most of the time it does not +have Windows because it's a bearing wall + + align:start position:0% +have Windows because it's a bearing wall + + + align:start position:0% +have Windows because it's a bearing wall +this one may not have been because of + + align:start position:0% +this one may not have been because of + + + align:start position:0% +this one may not have been because of +the Lan but we can assume that there's + + align:start position:0% +the Lan but we can assume that there's + + + align:start position:0% +the Lan but we can assume that there's +no windows here + + align:start position:0% + + + + align:start position:0% + +you are welcome to build then up against + + align:start position:0% +you are welcome to build then up against + + + align:start position:0% +you are welcome to build then up against +this oops up against this but + + align:start position:0% +this oops up against this but + + + align:start position:0% +this oops up against this but +not not against this and of course + + align:start position:0% +not not against this and of course + + + align:start position:0% +not not against this and of course +you're welcome to build up against a + + align:start position:0% +you're welcome to build up against a + + + align:start position:0% +you're welcome to build up against a +ventilator building in anywhere you see + + align:start position:0% +ventilator building in anywhere you see + + + align:start position:0% +ventilator building in anywhere you see +fit as we've already done + + align:start position:0% +fit as we've already done + + + align:start position:0% +fit as we've already done +any well this class is a good poke + + align:start position:0% +any well this class is a good poke + + + align:start position:0% +any well this class is a good poke +through class you know there's been a + + align:start position:0% +through class you know there's been a + + + align:start position:0% +through class you know there's been a +lot of poking that's been going on here + + align:start position:0% +lot of poking that's been going on here + + + align:start position:0% +lot of poking that's been going on here +um everybody's three or four been poking + + align:start position:0% +um everybody's three or four been poking + + + align:start position:0% +um everybody's three or four been poking +um yes you can poke which I don't think + + align:start position:0% +um yes you can poke which I don't think + + + align:start position:0% +um yes you can poke which I don't think +you can poke in this territory just like + + align:start position:0% +you can poke in this territory just like + + + align:start position:0% +you can poke in this territory just like +to are we taking project into account + + align:start position:0% +to are we taking project into account + + + align:start position:0% +to are we taking project into account +assuming that all the ls are there well + + align:start position:0% +assuming that all the ls are there well + + + align:start position:0% +assuming that all the ls are there well +in theory uh yes this is your community + + align:start position:0% +in theory uh yes this is your community + + + align:start position:0% +in theory uh yes this is your community +you're all living here now and that + + align:start position:0% +you're all living here now and that + + + align:start position:0% +you're all living here now and that +relates to the + + align:start position:0% +relates to the + + + align:start position:0% +relates to the +program and you should be thinking about + + align:start position:0% +program and you should be thinking about + + + align:start position:0% +program and you should be thinking about +that um but you may have a discussion + + align:start position:0% +that um but you may have a discussion + + + align:start position:0% +that um but you may have a discussion +with her if you feel it's important um + + align:start position:0% +with her if you feel it's important um + + + align:start position:0% +with her if you feel it's important um +and there's one here that you need to + + align:start position:0% +and there's one here that you need to + + + align:start position:0% +and there's one here that you need to +have a discuss discussion with you just + + align:start position:0% +have a discuss discussion with you just + + + align:start position:0% +have a discuss discussion with you just +have like a little elevator right up to + + align:start position:0% +have like a little elevator right up to + + + align:start position:0% +have like a little elevator right up to +my house well in your in all these cases + + align:start position:0% +my house well in your in all these cases + + + align:start position:0% +my house well in your in all these cases +you're getting into your house in some + + align:start position:0% +you're getting into your house in some + + + align:start position:0% +you're getting into your house in some +way which we're not worrying about but + + align:start position:0% +way which we're not worrying about but + + + align:start position:0% +way which we're not worrying about but +it's not on the + + align:start position:0% +it's not on the + + + align:start position:0% +it's not on the +site uh except for + + align:start position:0% +site uh except for + + + align:start position:0% +site uh except for +her so she may have to mod modify it + + align:start position:0% + + + + align:start position:0% + +slightly + + align:start position:0% + + + + align:start position:0% + +so got it so far with + + align:start position:0% +so got it so far with + + + align:start position:0% +so got it so far with +me again uh just to put it in + + align:start position:0% +me again uh just to put it in + + + align:start position:0% +me again uh just to put it in +perspective this is at 16th this is at + + align:start position:0% +perspective this is at 16th this is at + + + align:start position:0% +perspective this is at 16th this is at +8th we're going to start working at 16th + + align:start position:0% +8th we're going to start working at 16th + + + align:start position:0% +8th we're going to start working at 16th +then we'll move to 8th and quarter and + + align:start position:0% +then we'll move to 8th and quarter and + + + align:start position:0% +then we'll move to 8th and quarter and +full size and + + align:start position:0% +full size and + + + align:start position:0% +full size and +so well we may I'm hoping that we're + + align:start position:0% +so well we may I'm hoping that we're + + + align:start position:0% +so well we may I'm hoping that we're +going to build a piece of this at four + + align:start position:0% +going to build a piece of this at four + + + align:start position:0% +going to build a piece of this at four +not the whole + + align:start position:0% +not the whole + + + align:start position:0% +not the whole +thing now there's another issue that I + + align:start position:0% +thing now there's another issue that I + + + align:start position:0% +thing now there's another issue that I +want to talk about which is what I call + + align:start position:0% +want to talk about which is what I call + + + align:start position:0% +want to talk about which is what I call +the ordinary and the + + align:start position:0% +the ordinary and the + + + align:start position:0% +the ordinary and the +extraordinary and that is that there's + + align:start position:0% +extraordinary and that is that there's + + + align:start position:0% +extraordinary and that is that there's +an ordinary environment coming down this + + align:start position:0% +an ordinary environment coming down this + + + align:start position:0% +an ordinary environment coming down this +street b b b b b b Bo and then there's + + align:start position:0% +street b b b b b b Bo and then there's + + + align:start position:0% +street b b b b b b Bo and then there's +some something that you might call + + align:start position:0% +some something that you might call + + + align:start position:0% +some something that you might call +extraordinary but not very nice the + + align:start position:0% +extraordinary but not very nice the + + + align:start position:0% +extraordinary but not very nice the +ventilator + + align:start position:0% +ventilator + + + align:start position:0% +ventilator +Tower and in the nature of this design + + align:start position:0% +Tower and in the nature of this design + + + align:start position:0% +Tower and in the nature of this design +I'd like to have you pay attention to + + align:start position:0% +I'd like to have you pay attention to + + + align:start position:0% +I'd like to have you pay attention to +the + + align:start position:0% +the + + + align:start position:0% +the +ordinary as it relates to the this if + + align:start position:0% +ordinary as it relates to the this if + + + align:start position:0% +ordinary as it relates to the this if +you so choose to work here which does + + align:start position:0% +you so choose to work here which does + + + align:start position:0% +you so choose to work here which does +not mean fake clonal whatever this is by + + align:start position:0% +not mean fake clonal whatever this is by + + + align:start position:0% +not mean fake clonal whatever this is by +any means but it means being compatible + + align:start position:0% +any means but it means being compatible + + + align:start position:0% +any means but it means being compatible +to it and then you might move into + + align:start position:0% +to it and then you might move into + + + align:start position:0% +to it and then you might move into +something that's more unusual + + align:start position:0% +something that's more unusual + + + align:start position:0% +something that's more unusual +extraordinary so we're going from the + + align:start position:0% +extraordinary so we're going from the + + + align:start position:0% +extraordinary so we're going from the +ordinary on this side to the + + align:start position:0% +ordinary on this side to the + + + align:start position:0% +ordinary on this side to the +extraordinary that make + + align:start position:0% + + + + align:start position:0% + +sense the site has one more interesting + + align:start position:0% +sense the site has one more interesting + + + align:start position:0% +sense the site has one more interesting +and difficult issue what is + + align:start position:0% + + + + align:start position:0% + +it + + align:start position:0% +it + + + align:start position:0% +it +yes it does have that too and that's an + + align:start position:0% +yes it does have that too and that's an + + + align:start position:0% +yes it does have that too and that's an +interesting issue but there's another + + align:start position:0% +interesting issue but there's another + + + align:start position:0% +interesting issue but there's another +one is it on a grade sorry is it on a + + align:start position:0% +one is it on a grade sorry is it on a + + + align:start position:0% +one is it on a grade sorry is it on a +grade no it's flat we're making it flat + + align:start position:0% +grade no it's flat we're making it flat + + + align:start position:0% +grade no it's flat we're making it flat +space huh space well it's a bunch of + + align:start position:0% +space huh space well it's a bunch of + + + align:start position:0% +space huh space well it's a bunch of +dead spaces and that's our point of + + align:start position:0% +dead spaces and that's our point of + + + align:start position:0% +dead spaces and that's our point of +taking it to make life to it what else + + align:start position:0% +taking it to make life to it what else + + + align:start position:0% +taking it to make life to it what else +about the site + + align:start position:0% +about the site + + + align:start position:0% +about the site +Street this is forget about this forget + + align:start position:0% +Street this is forget about this forget + + + align:start position:0% +Street this is forget about this forget +about + + align:start position:0% + + + + align:start position:0% + +this the height of it what about height + + align:start position:0% +this the height of it what about height + + + align:start position:0% +this the height of it what about height +well it it's sort of it's like the Cory + + align:start position:0% +well it it's sort of it's like the Cory + + + align:start position:0% +well it it's sort of it's like the Cory +because that's like the water part of it + + align:start position:0% +because that's like the water part of it + + + align:start position:0% +because that's like the water part of it +the lower part + + align:start position:0% +the lower part + + + align:start position:0% +the lower part +else yeah but and huh come on come on + + align:start position:0% +else yeah but and huh come on come on + + + align:start position:0% +else yeah but and huh come on come on +Southern the things BL the + + align:start position:0% +Southern the things BL the + + + align:start position:0% +Southern the things BL the +southern so you don't have a lot of + + align:start position:0% +southern so you don't have a lot of + + + align:start position:0% +southern so you don't have a lot of +light yeah it's not a nice sight I mean + + align:start position:0% +light yeah it's not a nice sight I mean + + + align:start position:0% +light yeah it's not a nice sight I mean +you got a it's uh the sun is in the + + align:start position:0% +you got a it's uh the sun is in the + + + align:start position:0% +you got a it's uh the sun is in the +let's do it the sun in the winter is is + + align:start position:0% +let's do it the sun in the winter is is + + + align:start position:0% +let's do it the sun in the winter is is +it's rising somewhere in + + align:start position:0% +it's rising somewhere in + + + align:start position:0% +it's rising somewhere in +here I think it might get a little light + + align:start position:0% +here I think it might get a little light + + + align:start position:0% +here I think it might get a little light +no not at rise but maybe at noon it's + + align:start position:0% +no not at rise but maybe at noon it's + + + align:start position:0% +no not at rise but maybe at noon it's +going to get some light and then it's + + align:start position:0% +going to get some light and then it's + + + align:start position:0% +going to get some light and then it's +coming around and setting probably about + + align:start position:0% +coming around and setting probably about + + + align:start position:0% +coming around and setting probably about +here and now you get a little light on + + align:start position:0% +here and now you get a little light on + + + align:start position:0% +here and now you get a little light on +here on the summer it's better it's + + align:start position:0% +here on the summer it's better it's + + + align:start position:0% +here on the summer it's better it's +rising over here and probably get some + + align:start position:0% +rising over here and probably get some + + + align:start position:0% +rising over here and probably get some +light and maybe get some light all day + + align:start position:0% +light and maybe get some light all day + + + align:start position:0% +light and maybe get some light all day +but clearly these guys being so tall are + + align:start position:0% +but clearly these guys being so tall are + + + align:start position:0% +but clearly these guys being so tall are +casting + + align:start position:0% +casting + + + align:start position:0% +casting +Shadows most sites that you get in + + align:start position:0% +Shadows most sites that you get in + + + align:start position:0% +Shadows most sites that you get in +architectural School are south facing + + align:start position:0% +architectural School are south facing + + + align:start position:0% +architectural School are south facing +with a beautiful view that's not the + + align:start position:0% +with a beautiful view that's not the + + + align:start position:0% +with a beautiful view that's not the +case here this is uh North facing with a + + align:start position:0% +case here this is uh North facing with a + + + align:start position:0% +case here this is uh North facing with a +great view because we're seeing Sarah's + + align:start position:0% +great view because we're seeing Sarah's + + + align:start position:0% +great view because we're seeing Sarah's +wonderful building across the + + align:start position:0% +wonderful building across the + + + align:start position:0% +wonderful building across the +street um but it's + + align:start position:0% +street um but it's + + + align:start position:0% +street um but it's +different so light is an extreme + + align:start position:0% +different so light is an extreme + + + align:start position:0% +different so light is an extreme +important + + align:start position:0% +important + + + align:start position:0% +important +issue how we bounce light around how we + + align:start position:0% +issue how we bounce light around how we + + + align:start position:0% +issue how we bounce light around how we +get sunlight down into it and that makes + + align:start position:0% +get sunlight down into it and that makes + + + align:start position:0% +get sunlight down into it and that makes +this site + + align:start position:0% +this site + + + align:start position:0% +this site +unique you have to think about + + align:start position:0% +unique you have to think about + + + align:start position:0% +unique you have to think about +that I want you to go back to the site + + align:start position:0% +that I want you to go back to the site + + + align:start position:0% +that I want you to go back to the site +and look at the site now from the eyes + + align:start position:0% +and look at the site now from the eyes + + + align:start position:0% +and look at the site now from the eyes +of this project which I'm going to give + + align:start position:0% +of this project which I'm going to give + + + align:start position:0% +of this project which I'm going to give +you uh and of course you're aware of it + + align:start position:0% +you uh and of course you're aware of it + + + align:start position:0% +you uh and of course you're aware of it +one of the things that did not come out + + align:start position:0% +one of the things that did not come out + + + align:start position:0% +one of the things that did not come out +in the last project which you might + + align:start position:0% +in the last project which you might + + + align:start position:0% +in the last project which you might +think about is views from this site that + + align:start position:0% +think about is views from this site that + + + align:start position:0% +think about is views from this site that +you might see custom house tower down + + align:start position:0% +you might see custom house tower down + + + align:start position:0% +you might see custom house tower down +the street Etc next question what are we + + align:start position:0% +the street Etc next question what are we + + + align:start position:0% +the street Etc next question what are we +going to do with + + align:start position:0% +going to do with + + + align:start position:0% +going to do with +it this is the most important part I + + align:start position:0% +it this is the most important part I + + + align:start position:0% +it this is the most important part I +think + + align:start position:0% +think + + + align:start position:0% +think +think we are going to make and design a + + align:start position:0% +think we are going to make and design a + + + align:start position:0% +think we are going to make and design a +place + + align:start position:0% +place + + + align:start position:0% +place +here that will bring together you guys + + align:start position:0% +here that will bring together you guys + + + align:start position:0% +here that will bring together you guys +in your community in the sky North + + align:start position:0% +in your community in the sky North + + + align:start position:0% +in your community in the sky North +Enders who are living here tourists and + + align:start position:0% +Enders who are living here tourists and + + + align:start position:0% +Enders who are living here tourists and +anyone else you might think of into a + + align:start position:0% +anyone else you might think of into a + + + align:start position:0% +anyone else you might think of into a +meeting + + align:start position:0% +meeting + + + align:start position:0% +meeting +place which used to be called a + + align:start position:0% +place which used to be called a + + + align:start position:0% +place which used to be called a +community center which of course is the + + align:start position:0% +community center which of course is the + + + align:start position:0% +community center which of course is the +kiss of death to making anything + + align:start position:0% +kiss of death to making anything + + + align:start position:0% +kiss of death to making anything +Community if you ever label Community + + align:start position:0% +Community if you ever label Community + + + align:start position:0% +Community if you ever label Community +Center nobody will go there so we're not + + align:start position:0% +Center nobody will go there so we're not + + + align:start position:0% +Center nobody will go there so we're not +making in the typical sense a community + + align:start position:0% +making in the typical sense a community + + + align:start position:0% +making in the typical sense a community +center but we are making a place for + + align:start position:0% +center but we are making a place for + + + align:start position:0% +center but we are making a place for +people to come together in our age in in + + align:start position:0% +people to come together in our age in in + + + align:start position:0% +people to come together in our age in in +this age you guys could sit here all day + + align:start position:0% +this age you guys could sit here all day + + + align:start position:0% +this age you guys could sit here all day +long in your + + align:start position:0% +long in your + + + align:start position:0% +long in your +computer uh and do something but there + + align:start position:0% +computer uh and do something but there + + + align:start position:0% +computer uh and do something but there +may be a question about the quality of + + align:start position:0% +may be a question about the quality of + + + align:start position:0% +may be a question about the quality of +life that you have that may want you to + + align:start position:0% +life that you have that may want you to + + + align:start position:0% +life that you have that may want you to +get out for some reason for work or for + + align:start position:0% +get out for some reason for work or for + + + align:start position:0% +get out for some reason for work or for +whatever we are making that place of + + align:start position:0% +whatever we are making that place of + + + align:start position:0% +whatever we are making that place of +bringing together not only you + + align:start position:0% +bringing together not only you + + + align:start position:0% +bringing together not only you +guys but also North Enders because life + + align:start position:0% +guys but also North Enders because life + + + align:start position:0% +guys but also North Enders because life +is about meeting other people and + + align:start position:0% +is about meeting other people and + + + align:start position:0% +is about meeting other people and +architecture is about bringing people + + align:start position:0% +architecture is about bringing people + + + align:start position:0% +architecture is about bringing people +together so we're making a coming + + align:start position:0% +together so we're making a coming + + + align:start position:0% +together so we're making a coming +together + + align:start position:0% +together + + + align:start position:0% +together +space that's our program + + align:start position:0% +space that's our program + + + align:start position:0% +space that's our program +basically and that's up to you to + + align:start position:0% +basically and that's up to you to + + + align:start position:0% +basically and that's up to you to +decide to be a good architect is + + align:start position:0% +decide to be a good architect is + + + align:start position:0% +decide to be a good architect is +important to be a good + + align:start position:0% +important to be a good + + + align:start position:0% +important to be a good +designer but to be a good programmer to + + align:start position:0% +designer but to be a good programmer to + + + align:start position:0% +designer but to be a good programmer to +think about the spirit of what the + + align:start position:0% +think about the spirit of what the + + + align:start position:0% +think about the spirit of what the +architecture is going to be is a real + + align:start position:0% +architecture is going to be is a real + + + align:start position:0% +architecture is going to be is a real +genius and that's what I'm asking you + + align:start position:0% +genius and that's what I'm asking you + + + align:start position:0% +genius and that's what I'm asking you +guys to + + align:start position:0% +guys to + + + align:start position:0% +guys to +be I'm asking you to be very creative in + + align:start position:0% +be I'm asking you to be very creative in + + + align:start position:0% +be I'm asking you to be very creative in +thinking about what brings people + + align:start position:0% +thinking about what brings people + + + align:start position:0% +thinking about what brings people +together and then design the most + + align:start position:0% +together and then design the most + + + align:start position:0% +together and then design the most +beautiful place for + + align:start position:0% +beautiful place for + + + align:start position:0% +beautiful place for +it I believe very much in this way of + + align:start position:0% +it I believe very much in this way of + + + align:start position:0% +it I believe very much in this way of +working because otherwise I think you + + align:start position:0% +working because otherwise I think you + + + align:start position:0% +working because otherwise I think you +come out to be teats in the way that you + + align:start position:0% +come out to be teats in the way that you + + + align:start position:0% +come out to be teats in the way that you +are just hired architects and do what + + align:start position:0% +are just hired architects and do what + + + align:start position:0% +are just hired architects and do what +somebody tells you and I believe that + + align:start position:0% +somebody tells you and I believe that + + + align:start position:0% +somebody tells you and I believe that +the architecture profession can offer + + align:start position:0% +the architecture profession can offer + + + align:start position:0% +the architecture profession can offer +more than that you're not Engineers + + align:start position:0% +more than that you're not Engineers + + + align:start position:0% +more than that you're not Engineers +you're not designing just a bridge to + + align:start position:0% +you're not designing just a bridge to + + + align:start position:0% +you're not designing just a bridge to +stay up you're designing life or an echo + + align:start position:0% +stay up you're designing life or an echo + + + align:start position:0% +stay up you're designing life or an echo +of life so in this case what is it that + + align:start position:0% +of life so in this case what is it that + + + align:start position:0% +of life so in this case what is it that +the echo + + align:start position:0% +the echo + + + align:start position:0% +the echo +is the program which I'll hand out in a + + align:start position:0% +is the program which I'll hand out in a + + + align:start position:0% +is the program which I'll hand out in a +second + + align:start position:0% + + + + align:start position:0% + +um is about 6,000 square feet of of + + align:start position:0% +um is about 6,000 square feet of of + + + align:start position:0% +um is about 6,000 square feet of of +stuff which is more than that's about uh + + align:start position:0% +stuff which is more than that's about uh + + + align:start position:0% +stuff which is more than that's about uh +well we all cheated but that's about six + + align:start position:0% +well we all cheated but that's about six + + + align:start position:0% +well we all cheated but that's about six +of these right five of + + align:start position:0% +of these right five of + + + align:start position:0% +of these right five of +these or it should + + align:start position:0% +these or it should + + + align:start position:0% +these or it should +be + + align:start position:0% +be + + + align:start position:0% +be +um so somehow you're going to get 6,000 + + align:start position:0% +um so somehow you're going to get 6,000 + + + align:start position:0% +um so somehow you're going to get 6,000 +roughly 6,000 it can be + + align:start position:0% +roughly 6,000 it can be + + + align:start position:0% +roughly 6,000 it can be +more there should be in that + + align:start position:0% +more there should be in that + + + align:start position:0% +more there should be in that +program no matter what you're doing some + + align:start position:0% +program no matter what you're doing some + + + align:start position:0% +program no matter what you're doing some +space in there where a good number of + + align:start position:0% +space in there where a good number of + + + align:start position:0% +space in there where a good number of +people can + + align:start position:0% +people can + + + align:start position:0% +people can +meet together a a meeting + + align:start position:0% +meet together a a meeting + + + align:start position:0% +meet together a a meeting +place I don't know what that is is that + + align:start position:0% +place I don't know what that is is that + + + align:start position:0% +place I don't know what that is is that +an exhibition hall for art is that a + + align:start position:0% +an exhibition hall for art is that a + + + align:start position:0% +an exhibition hall for art is that a +movie theater is that an ice skating + + align:start position:0% +movie theater is that an ice skating + + + align:start position:0% +movie theater is that an ice skating +rink I don't know what it is that's up + + align:start position:0% +rink I don't know what it is that's up + + + align:start position:0% +rink I don't know what it is that's up +to you to think + + align:start position:0% +to you to think + + + align:start position:0% +to you to think +about there should be some spaces in + + align:start position:0% +about there should be some spaces in + + + align:start position:0% +about there should be some spaces in +here that are mediumsized + + align:start position:0% +here that are mediumsized + + + align:start position:0% +here that are mediumsized +where people might come together to have + + align:start position:0% +where people might come together to have + + + align:start position:0% +where people might come together to have +meetings or + + align:start position:0% +meetings or + + + align:start position:0% +meetings or +daycare or elder + + align:start position:0% +daycare or elder + + + align:start position:0% +daycare or elder +care and there should be some small + + align:start position:0% +care and there should be some small + + + align:start position:0% +care and there should be some small +spaces in here here where you might work + + align:start position:0% +spaces in here here where you might work + + + align:start position:0% +spaces in here here where you might work +maybe you work all day on your computer + + align:start position:0% +maybe you work all day on your computer + + + align:start position:0% +maybe you work all day on your computer +and in virtual world but this is your + + align:start position:0% +and in virtual world but this is your + + + align:start position:0% +and in virtual world but this is your +true life is making + + align:start position:0% +true life is making + + + align:start position:0% +true life is making +furniture and we may be shifting in our + + align:start position:0% +furniture and we may be shifting in our + + + align:start position:0% +furniture and we may be shifting in our +ways of thinking about work and + + align:start position:0% +ways of thinking about work and + + + align:start position:0% +ways of thinking about work and +life uh as it's been before so maybe you + + align:start position:0% +life uh as it's been before so maybe you + + + align:start position:0% +life uh as it's been before so maybe you +make furniture there and you sell it on + + align:start position:0% +make furniture there and you sell it on + + + align:start position:0% +make furniture there and you sell it on +your computer in your house I don't know + + align:start position:0% +your computer in your house I don't know + + + align:start position:0% +your computer in your house I don't know +that's up to you so it might be + + align:start position:0% +that's up to you so it might be + + + align:start position:0% +that's up to you so it might be +workspaces there the point is there's + + align:start position:0% +workspaces there the point is there's + + + align:start position:0% +workspaces there the point is there's +some small there's some medium siiz and + + align:start position:0% +some small there's some medium siiz and + + + align:start position:0% +some small there's some medium siiz and +there's one big + + align:start position:0% + + + + align:start position:0% + +one as I said before all good + + align:start position:0% +one as I said before all good + + + align:start position:0% +one as I said before all good +architecture has a vertical connection + + align:start position:0% +architecture has a vertical connection + + + align:start position:0% +architecture has a vertical connection +and a horizontal connection of space + + align:start position:0% +and a horizontal connection of space + + + align:start position:0% +and a horizontal connection of space +this building should have that a + + align:start position:0% +this building should have that a + + + align:start position:0% +this building should have that a +vertical and a horizontal so therefore + + align:start position:0% +vertical and a horizontal so therefore + + + align:start position:0% +vertical and a horizontal so therefore +space in some way should be flowing + + align:start position:0% +space in some way should be flowing + + + align:start position:0% +space in some way should be flowing +through the building vertically and + + align:start position:0% +through the building vertically and + + + align:start position:0% +through the building vertically and +horizontally some part of the building + + align:start position:0% +horizontally some part of the building + + + align:start position:0% +horizontally some part of the building +but not all should get up to be a + + align:start position:0% +but not all should get up to be a + + + align:start position:0% +but not all should get up to be a +companion to these ever buildings which + + align:start position:0% +companion to these ever buildings which + + + align:start position:0% +companion to these ever buildings which +is three stories or so + + align:start position:0% +is three stories or so + + + align:start position:0% +is three stories or so +but the whole thing doesn't have to do + + align:start position:0% +but the whole thing doesn't have to do + + + align:start position:0% +but the whole thing doesn't have to do +that now let me just put in parenthesis + + align:start position:0% +that now let me just put in parenthesis + + + align:start position:0% +that now let me just put in parenthesis +part of this project is to get you to + + align:start position:0% +part of this project is to get you to + + + align:start position:0% +part of this project is to get you to +think about three-dimensional + + align:start position:0% +think about three-dimensional + + + align:start position:0% +think about three-dimensional +programming and how you express that + + align:start position:0% +programming and how you express that + + + align:start position:0% +programming and how you express that +architecturally because for the most + + align:start position:0% +architecturally because for the most + + + align:start position:0% +architecturally because for the most +part you've been doing it on in your + + align:start position:0% +part you've been doing it on in your + + + align:start position:0% +part you've been doing it on in your +head you're able to keep track of one or + + align:start position:0% +head you're able to keep track of one or + + + align:start position:0% +head you're able to keep track of one or +two or three stories but now you can't + + align:start position:0% +two or three stories but now you can't + + + align:start position:0% +two or three stories but now you can't +you're going to have to think + + align:start position:0% +you're going to have to think + + + align:start position:0% +you're going to have to think +three-dimensionally and work + + align:start position:0% +three-dimensionally and work + + + align:start position:0% +three-dimensionally and work +three-dimensionally so the program is + + align:start position:0% +three-dimensionally so the program is + + + align:start position:0% +three-dimensionally so the program is +intended not to be horizontal suburb + + align:start position:0% +intended not to be horizontal suburb + + + align:start position:0% +intended not to be horizontal suburb +Community Center right it's not + + align:start position:0% +Community Center right it's not + + + align:start position:0% +Community Center right it's not +that about 2third of the side should be + + align:start position:0% +that about 2third of the side should be + + + align:start position:0% +that about 2third of the side should be +left + + align:start position:0% +left + + + align:start position:0% +left +open or left + + align:start position:0% +open or left + + + align:start position:0% +open or left +untouched so that which is in the last + + align:start position:0% +untouched so that which is in the last + + + align:start position:0% +untouched so that which is in the last +part of + + align:start position:0% +part of + + + align:start position:0% +part of +this that wonderful experience that we + + align:start position:0% +this that wonderful experience that we + + + align:start position:0% +this that wonderful experience that we +had the very first day of going to the + + align:start position:0% +had the very first day of going to the + + + align:start position:0% +had the very first day of going to the +Quarry of nature call it nature water it + + align:start position:0% +Quarry of nature call it nature water it + + + align:start position:0% +Quarry of nature call it nature water it +wasn't nature but that's okay we in some + + align:start position:0% +wasn't nature but that's okay we in some + + + align:start position:0% +wasn't nature but that's okay we in some +form are bringing nature back into the + + align:start position:0% +form are bringing nature back into the + + + align:start position:0% +form are bringing nature back into the +city which is badly needed in this part + + align:start position:0% +city which is badly needed in this part + + + align:start position:0% +city which is badly needed in this part +of this city nothing is staying this + + align:start position:0% +of this city nothing is staying this + + + align:start position:0% +of this city nothing is staying this +here but I'm inviting you to think about + + align:start position:0% +here but I'm inviting you to think about + + + align:start position:0% +here but I'm inviting you to think about +what does it mean to bring nature back + + align:start position:0% +what does it mean to bring nature back + + + align:start position:0% +what does it mean to bring nature back +into the city for a place that's as + + align:start position:0% +into the city for a place that's as + + + align:start position:0% +into the city for a place that's as +dense as this that they have one tree + + align:start position:0% +dense as this that they have one tree + + + align:start position:0% +dense as this that they have one tree +here and one here and I guess some here + + align:start position:0% +here and one here and I guess some here + + + align:start position:0% +here and one here and I guess some here +no water anywhere in the except for the + + align:start position:0% +no water anywhere in the except for the + + + align:start position:0% +no water anywhere in the except for the +Fountain and and the PA R's + + align:start position:0% +Fountain and and the PA R's + + + align:start position:0% +Fountain and and the PA R's +wall to my knowledge no natural um stone + + align:start position:0% +wall to my knowledge no natural um stone + + + align:start position:0% +wall to my knowledge no natural um stone +or no natural so-call natural grass in + + align:start position:0% +or no natural so-call natural grass in + + + align:start position:0% +or no natural so-call natural grass in +anywhere in the nor fin for a community + + align:start position:0% +anywhere in the nor fin for a community + + + align:start position:0% +anywhere in the nor fin for a community +maybe + + align:start position:0% +maybe + + + align:start position:0% +maybe +private so what does that + + align:start position:0% + + + + align:start position:0% + +mean you might bring water into this + + align:start position:0% +mean you might bring water into this + + + align:start position:0% +mean you might bring water into this +site because it used to be Water by the + + align:start position:0% +site because it used to be Water by the + + + align:start position:0% +site because it used to be Water by the +way this was a short + + align:start position:0% +way this was a short + + + align:start position:0% +way this was a short +one you might bring trees into this site + + align:start position:0% +one you might bring trees into this site + + + align:start position:0% +one you might bring trees into this site +but if you're bring + + align:start position:0% +but if you're bring + + + align:start position:0% +but if you're bring +trees do not do what Architects do which + + align:start position:0% +trees do not do what Architects do which + + + align:start position:0% +trees do not do what Architects do which +is what I call throwing darts at the + + align:start position:0% +is what I call throwing darts at the + + + align:start position:0% +is what I call throwing darts at the +drawing 10 minutes before it's do and + + align:start position:0% +drawing 10 minutes before it's do and + + + align:start position:0% +drawing 10 minutes before it's do and +placing + + align:start position:0% +placing + + + align:start position:0% +placing +trees and then you know they you put + + align:start position:0% +trees and then you know they you put + + + align:start position:0% +trees and then you know they you put +trees and then you put little benches on + + align:start position:0% +trees and then you put little benches on + + + align:start position:0% +trees and then you put little benches on +it and you call it open space you think + + align:start position:0% +it and you call it open space you think + + + align:start position:0% +it and you call it open space you think +people are going to H live happily ever + + align:start position:0% +people are going to H live happily ever + + + align:start position:0% +people are going to H live happily ever +after and they're not it's going to have + + align:start position:0% +after and they're not it's going to have + + + align:start position:0% +after and they're not it's going to have +to be more than that if you do trees or + + align:start position:0% +to be more than that if you do trees or + + + align:start position:0% +to be more than that if you do trees or +any kind of + + align:start position:0% +any kind of + + + align:start position:0% +any kind of +vegetation it could be a way of using uh + + align:start position:0% +vegetation it could be a way of using uh + + + align:start position:0% +vegetation it could be a way of using uh +materials Stone from the Quarry maybe + + align:start position:0% +materials Stone from the Quarry maybe + + + align:start position:0% +materials Stone from the Quarry maybe +you go back to the quy and get some + + align:start position:0% +you go back to the quy and get some + + + align:start position:0% +you go back to the quy and get some +Quarry materials and bring it here and + + align:start position:0% +Quarry materials and bring it here and + + + align:start position:0% +Quarry materials and bring it here and +civilize it in some way combine it with + + align:start position:0% +civilize it in some way combine it with + + + align:start position:0% +civilize it in some way combine it with +water and trees + + align:start position:0% +water and trees + + + align:start position:0% +water and trees +that's up to you decide what that is but + + align:start position:0% +that's up to you decide what that is but + + + align:start position:0% +that's up to you decide what that is but +when you're + + align:start position:0% +when you're + + + align:start position:0% +when you're +done with this and + + align:start position:0% +done with this and + + + align:start position:0% +done with this and +this people no longer are going down the + + align:start position:0% +this people no longer are going down the + + + align:start position:0% +this people no longer are going down the +red line to see Paul R's house they're + + align:start position:0% +red line to see Paul R's house they're + + + align:start position:0% +red line to see Paul R's house they're +going down a purple line to see your + + align:start position:0% +going down a purple line to see your + + + align:start position:0% +going down a purple line to see your +place because it's much better than + + align:start position:0% +place because it's much better than + + + align:start position:0% +place because it's much better than +anything that they ever seen so those + + align:start position:0% +anything that they ever seen so those + + + align:start position:0% +anything that they ever seen so those +people coming from Ohio where I came + + align:start position:0% +people coming from Ohio where I came + + + align:start position:0% +people coming from Ohio where I came +from could care less about Paul's Place + + align:start position:0% +from could care less about Paul's Place + + + align:start position:0% +from could care less about Paul's Place +but they really care about your place + + align:start position:0% +but they really care about your place + + + align:start position:0% +but they really care about your place +such as a little Park in New York where + + align:start position:0% +such as a little Park in New York where + + + align:start position:0% +such as a little Park in New York where +there's a waterfall at the back you know + + align:start position:0% +there's a waterfall at the back you know + + + align:start position:0% +there's a waterfall at the back you know +and never know the name of it you + + align:start position:0% +and never know the name of it you + + + align:start position:0% +and never know the name of it you +another one yep wonderful little Oasis + + align:start position:0% +another one yep wonderful little Oasis + + + align:start position:0% +another one yep wonderful little Oasis +in the middle of Chaos in my opinion um + + align:start position:0% +in the middle of Chaos in my opinion um + + + align:start position:0% +in the middle of Chaos in my opinion um +those are special places that's what + + align:start position:0% +those are special places that's what + + + align:start position:0% +those are special places that's what +you're making a very special + + align:start position:0% +you're making a very special + + + align:start position:0% +you're making a very special +place + + align:start position:0% +place + + + align:start position:0% +place +so that's + + align:start position:0% +so that's + + + align:start position:0% +so that's +the turn or the complete James Joy cycle + + align:start position:0% +the turn or the complete James Joy cycle + + + align:start position:0% +the turn or the complete James Joy cycle +from the beginning of the quy back to + + align:start position:0% +from the beginning of the quy back to + + + align:start position:0% +from the beginning of the quy back to +something like the + + align:start position:0% +something like the + + + align:start position:0% +something like the +quy you with me + + align:start position:0% + + + + align:start position:0% + +guys + + align:start position:0% +guys + + + align:start position:0% +guys +um well I've already said that the + + align:start position:0% +um well I've already said that the + + + align:start position:0% +um well I've already said that the +ordinary and the extraordinary has to be + + align:start position:0% +ordinary and the extraordinary has to be + + + align:start position:0% +ordinary and the extraordinary has to be +combined somehow on the site so you're + + align:start position:0% +combined somehow on the site so you're + + + align:start position:0% +combined somehow on the site so you're +not parking a spaceship in here + + align:start position:0% +not parking a spaceship in here + + + align:start position:0% +not parking a spaceship in here +know that's not what you're doing it's + + align:start position:0% +know that's not what you're doing it's + + + align:start position:0% +know that's not what you're doing it's +not a landing field landing pad + + align:start position:0% +not a landing field landing pad + + + align:start position:0% +not a landing field landing pad +for sorry you thought I had forgotten + + align:start position:0% +for sorry you thought I had forgotten + + + align:start position:0% +for sorry you thought I had forgotten +but I will remember it for 20 + + align:start position:0% +but I will remember it for 20 + + + align:start position:0% +but I will remember it for 20 +years um so you're not doing that but + + align:start position:0% +years um so you're not doing that but + + + align:start position:0% +years um so you're not doing that but +you're also not imitating what's there + + align:start position:0% +you're also not imitating what's there + + + align:start position:0% +you're also not imitating what's there +it's it's a bore don't do that no you + + align:start position:0% +it's it's a bore don't do that no you + + + align:start position:0% +it's it's a bore don't do that no you +guys none of you guys did that in + + align:start position:0% +guys none of you guys did that in + + + align:start position:0% +guys none of you guys did that in +this um how can you make a billboard in + + align:start position:0% +this um how can you make a billboard in + + + align:start position:0% +this um how can you make a billboard in +there like that which I'm not suggesting + + align:start position:0% +there like that which I'm not suggesting + + + align:start position:0% +there like that which I'm not suggesting +you did but also relate incredible + + align:start position:0% +you did but also relate incredible + + + align:start position:0% +you did but also relate incredible +problems beautiful idea I mean how to do + + align:start position:0% +problems beautiful idea I mean how to do + + + align:start position:0% +problems beautiful idea I mean how to do +that I don't + + align:start position:0% +that I don't + + + align:start position:0% +that I don't +know but that's what your that's your + + align:start position:0% + + + + align:start position:0% + +challenge finally in my opinion in any + + align:start position:0% +challenge finally in my opinion in any + + + align:start position:0% +challenge finally in my opinion in any +good building it's the public space of + + align:start position:0% +good building it's the public space of + + + align:start position:0% +good building it's the public space of +paths and places + + align:start position:0% +paths and places + + + align:start position:0% +paths and places +which I will talk about the space + + align:start position:0% +which I will talk about the space + + + align:start position:0% +which I will talk about the space +between the U + + align:start position:0% +between the U + + + align:start position:0% +between the U +assignment number + + align:start position:0% +assignment number + + + align:start position:0% +assignment number +six uh in the sequence of things first + + align:start position:0% +six uh in the sequence of things first + + + align:start position:0% +six uh in the sequence of things first +for this which is due next + + align:start position:0% +for this which is due next + + + align:start position:0% +for this which is due next +Tuesday uh I'm going to read it for this + + align:start position:0% +Tuesday uh I'm going to read it for this + + + align:start position:0% +Tuesday uh I'm going to read it for this +assignment you are asked to think about + + align:start position:0% +assignment you are asked to think about + + + align:start position:0% +assignment you are asked to think about +what this building wants to + + align:start position:0% + + + + align:start position:0% + +be I'm asking you + + align:start position:0% +be I'm asking you + + + align:start position:0% +be I'm asking you +again what is the program that would + + align:start position:0% +again what is the program that would + + + align:start position:0% +again what is the program that would +satis ify your needs and bring people + + align:start position:0% +satis ify your needs and bring people + + + align:start position:0% +satis ify your needs and bring people +together in the + + align:start position:0% +together in the + + + align:start position:0% +together in the +community how can we get people to come + + align:start position:0% +community how can we get people to come + + + align:start position:0% +community how can we get people to come +together again I'm + + align:start position:0% +together again I'm + + + align:start position:0% +together again I'm +reiterating what kind of spaces for work + + align:start position:0% +reiterating what kind of spaces for work + + + align:start position:0% +reiterating what kind of spaces for work +would you want and + + align:start position:0% +would you want and + + + align:start position:0% +would you want and +need how can we design buildings in our + + align:start position:0% +need how can we design buildings in our + + + align:start position:0% +need how can we design buildings in our +present + + align:start position:0% +present + + + align:start position:0% +present +Society present Society being the + + align:start position:0% +Society present Society being the + + + align:start position:0% +Society present Society being the +Society of Technology of + + align:start position:0% +Society of Technology of + + + align:start position:0% +Society of Technology of +computers um that can bring people + + align:start position:0% +computers um that can bring people + + + align:start position:0% +computers um that can bring people +together and address the issue of + + align:start position:0% +together and address the issue of + + + align:start position:0% +together and address the issue of +community because we're still we still + + align:start position:0% +community because we're still we still + + + align:start position:0% +community because we're still we still +want to come together + + align:start position:0% +want to come together + + + align:start position:0% +want to come together +somehow yet the machine the technology + + align:start position:0% +somehow yet the machine the technology + + + align:start position:0% +somehow yet the machine the technology +age is pushing us away from each other + + align:start position:0% +age is pushing us away from each other + + + align:start position:0% +age is pushing us away from each other +to a certain + + align:start position:0% +to a certain + + + align:start position:0% +to a certain +extent what is the connection to + + align:start position:0% +extent what is the connection to + + + align:start position:0% +extent what is the connection to +nature which is also a basic need of + + align:start position:0% +nature which is also a basic need of + + + align:start position:0% +nature which is also a basic need of +us how can nature be introduced into the + + align:start position:0% +us how can nature be introduced into the + + + align:start position:0% +us how can nature be introduced into the +city these are all questions I'm asking + + align:start position:0% +city these are all questions I'm asking + + + align:start position:0% +city these are all questions I'm asking +you for the program + + align:start position:0% +you for the program + + + align:start position:0% +you for the program +I say it would be a good time to revisit + + align:start position:0% +I say it would be a good time to revisit + + + align:start position:0% +I say it would be a good time to revisit +the site and understand more of the + + align:start position:0% +the site and understand more of the + + + align:start position:0% +the site and understand more of the +community uh you might do this by being + + align:start position:0% +community uh you might do this by being + + + align:start position:0% +community uh you might do this by being +there at different times of the day by + + align:start position:0% +there at different times of the day by + + + align:start position:0% +there at different times of the day by +talking with people who live there or by + + align:start position:0% +talking with people who live there or by + + + align:start position:0% +talking with people who live there or by +understanding the history of the area + + align:start position:0% +understanding the history of the area + + + align:start position:0% +understanding the history of the area +which you do understand to a certain + + align:start position:0% +which you do understand to a certain + + + align:start position:0% +which you do understand to a certain +extent but more so so you might go down + + align:start position:0% +extent but more so so you might go down + + + align:start position:0% +extent but more so so you might go down +today go in the night go in the weekend + + align:start position:0% +today go in the night go in the weekend + + + align:start position:0% +today go in the night go in the weekend +with + + align:start position:0% +with + + + align:start position:0% +with +somebody from your observations ideas + + align:start position:0% +somebody from your observations ideas + + + align:start position:0% +somebody from your observations ideas +for the program and form should come + + align:start position:0% + + + + align:start position:0% + +got + + align:start position:0% +got + + + align:start position:0% +got +it for next + + align:start position:0% +it for next + + + align:start position:0% +it for next +Tuesday we're going to have a pin up the + + align:start position:0% +Tuesday we're going to have a pin up the + + + align:start position:0% +Tuesday we're going to have a pin up the +following should be done two 20x 50 + + align:start position:0% +following should be done two 20x 50 + + + align:start position:0% +following should be done two 20x 50 +boards to include your attitude quote + + align:start position:0% +boards to include your attitude quote + + + align:start position:0% +boards to include your attitude quote +attitude about the building program uses + + align:start position:0% +attitude about the building program uses + + + align:start position:0% +attitude about the building program uses +and + + align:start position:0% +and + + + align:start position:0% +and +sizes I'm looking for you to produce + + align:start position:0% +sizes I'm looking for you to produce + + + align:start position:0% +sizes I'm looking for you to produce +Montage boards again that express your + + align:start position:0% +Montage boards again that express your + + + align:start position:0% +Montage boards again that express your +idea about how we're going to come + + align:start position:0% +idea about how we're going to come + + + align:start position:0% +idea about how we're going to come +together on this site + + align:start position:0% +together on this site + + + align:start position:0% +together on this site +I'm also asking you to make areas of + + align:start position:0% +I'm also asking you to make areas of + + + align:start position:0% +I'm also asking you to make areas of +colored paper to show the sizes of the + + align:start position:0% +colored paper to show the sizes of the + + + align:start position:0% +colored paper to show the sizes of the +program at the scale of 16 which we're + + align:start position:0% +program at the scale of 16 which we're + + + align:start position:0% +program at the scale of 16 which we're +working at which is + + align:start position:0% +working at which is + + + align:start position:0% +working at which is +this um that talks about the size of the + + align:start position:0% +this um that talks about the size of the + + + align:start position:0% +this um that talks about the size of the +building remember this is a vertical + + align:start position:0% +building remember this is a vertical + + + align:start position:0% +building remember this is a vertical +building so that's on the boards that's + + align:start position:0% +building so that's on the boards that's + + + align:start position:0% +building so that's on the boards that's +on the + + align:start position:0% +on the + + + align:start position:0% +on the +boards and I'm asking you sketches about + + align:start position:0% +boards and I'm asking you sketches about + + + align:start position:0% +boards and I'm asking you sketches about +how you might use the + + align:start position:0% +how you might use the + + + align:start position:0% +how you might use the +site include at 116 scale at least one + + align:start position:0% +site include at 116 scale at least one + + + align:start position:0% +site include at 116 scale at least one +General SK sketch plan but more I'm + + align:start position:0% +General SK sketch plan but more I'm + + + align:start position:0% +General SK sketch plan but more I'm +looking for more than + + align:start position:0% + + + + align:start position:0% + +one \ No newline at end of file diff --git a/7eQ4Xt5mAXQ.txt b/7eQ4Xt5mAXQ.txt new file mode 100644 index 0000000000000000000000000000000000000000..8dc65cda1372edef52d20f0f217eae40f528c911 --- /dev/null +++ b/7eQ4Xt5mAXQ.txt @@ -0,0 +1,8427 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit MIT open courseware + + align:start position:0% +of MIT courses visit MIT open courseware + + + align:start position:0% +of MIT courses visit MIT open courseware +at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +so how does a writer like Butler + + align:start position:0% +so how does a writer like Butler + + + align:start position:0% +so how does a writer like Butler +sort hit upon this subject I mean is + + align:start position:0% +sort hit upon this subject I mean is + + + align:start position:0% +sort hit upon this subject I mean is +this + + align:start position:0% +this + + + align:start position:0% +this +um I mean Butler was + + align:start position:0% +um I mean Butler was + + + align:start position:0% +um I mean Butler was +U he was a generation younger than + + align:start position:0% +U he was a generation younger than + + + align:start position:0% +U he was a generation younger than +Darwin but you know not that not that + + align:start position:0% +Darwin but you know not that not that + + + align:start position:0% +Darwin but you know not that not that +much younger he had met Darwin Darwin + + align:start position:0% +much younger he had met Darwin Darwin + + + align:start position:0% +much younger he had met Darwin Darwin +after the this book was published Darwin + + align:start position:0% +after the this book was published Darwin + + + align:start position:0% +after the this book was published Darwin +invited him to his house he was very + + align:start position:0% +invited him to his house he was very + + + align:start position:0% +invited him to his house he was very +interested uh he wanted to explore this + + align:start position:0% +interested uh he wanted to explore this + + + align:start position:0% +interested uh he wanted to explore this +what you know what's going on in this + + align:start position:0% +what you know what's going on in this + + + align:start position:0% +what you know what's going on in this +guy's mind because there were lots of + + align:start position:0% +guy's mind because there were lots of + + + align:start position:0% +guy's mind because there were lots of +things going on here that uh uh you know + + align:start position:0% +things going on here that uh uh you know + + + align:start position:0% +things going on here that uh uh you know +Darwin found rather fascinating so why + + align:start position:0% +Darwin found rather fascinating so why + + + align:start position:0% +Darwin found rather fascinating so why +would Darwin even care about a book like + + align:start position:0% +would Darwin even care about a book like + + + align:start position:0% +would Darwin even care about a book like +this what's in this book + + align:start position:0% +this what's in this book + + + align:start position:0% +this what's in this book +that might interest uh you know great + + align:start position:0% +that might interest uh you know great + + + align:start position:0% +that might interest uh you know great +scientists like Charles + + align:start position:0% +scientists like Charles + + + align:start position:0% +scientists like Charles +Darwin I'm not saying that Butler and + + align:start position:0% +Darwin I'm not saying that Butler and + + + align:start position:0% +Darwin I'm not saying that Butler and +Darwin got along but Dar invited him + + align:start position:0% +Darwin got along but Dar invited him + + + align:start position:0% +Darwin got along but Dar invited him +down to his house for a weekend to um + + align:start position:0% +down to his house for a weekend to um + + + align:start position:0% +down to his house for a weekend to um +talk with him so what's here yeah TR + + align:start position:0% +talk with him so what's here yeah TR + + + align:start position:0% +talk with him so what's here yeah TR +well kind of um in in a way the + + align:start position:0% +well kind of um in in a way the + + + align:start position:0% +well kind of um in in a way the +professor like the professor did for + + align:start position:0% +professor like the professor did for + + + align:start position:0% +professor like the professor did for +machines what Darwin did for living + + align:start position:0% +machines what Darwin did for living + + + align:start position:0% +machines what Darwin did for living +living things in terms of + + align:start position:0% +living things in terms of + + + align:start position:0% +living things in terms of +how like the like machines can like they + + align:start position:0% +how like the like machines can like they + + + align:start position:0% +how like the like machines can like they +all have their own varieties there's + + align:start position:0% +all have their own varieties there's + + + align:start position:0% +all have their own varieties there's +like variation and then there's also + + align:start position:0% +like variation and then there's also + + + align:start position:0% +like variation and then there's also +like gradual increments how they just + + align:start position:0% +like gradual increments how they just + + + align:start position:0% +like gradual increments how they just +get better and better and then obviously + + align:start position:0% +get better and better and then obviously + + + align:start position:0% +get better and better and then obviously +like if they don't get + + align:start position:0% +like if they don't get + + + align:start position:0% +like if they don't get +better like they just like get discarded + + align:start position:0% +better like they just like get discarded + + + align:start position:0% +better like they just like get discarded +and so it's kind of like Evolution for + + align:start position:0% +and so it's kind of like Evolution for + + + align:start position:0% +and so it's kind of like Evolution for +machines yeah so it's really I mean we + + align:start position:0% +machines yeah so it's really I mean we + + + align:start position:0% +machines yeah so it's really I mean we +certainly all admit don't we that + + align:start position:0% +certainly all admit don't we that + + + align:start position:0% +certainly all admit don't we that +machines are constantly being improved + + align:start position:0% +machines are constantly being improved + + + align:start position:0% +machines are constantly being improved +upon and the first versions are rarely + + align:start position:0% +upon and the first versions are rarely + + + align:start position:0% +upon and the first versions are rarely +you know the ones that are the + + align:start position:0% +you know the ones that are the + + + align:start position:0% +you know the ones that are the +Contemporary ones yeah I think like up + + align:start position:0% +Contemporary ones yeah I think like up + + + align:start position:0% +Contemporary ones yeah I think like up +until this point obviously we've been + + align:start position:0% +until this point obviously we've been + + + align:start position:0% +until this point obviously we've been +controlling that progression and the + + align:start position:0% +controlling that progression and the + + + align:start position:0% +controlling that progression and the +book to a point where they're like + + align:start position:0% +book to a point where they're like + + + align:start position:0% +book to a point where they're like +almost evolving + + align:start position:0% +almost evolving + + + align:start position:0% +almost evolving +naturally and I don't yeah yeah no this + + align:start position:0% +naturally and I don't yeah yeah no this + + + align:start position:0% +naturally and I don't yeah yeah no this +is this is we we're not going to Grant + + align:start position:0% +is this is we we're not going to Grant + + + align:start position:0% +is this is we we're not going to Grant +this crazy Professor his his points here + + align:start position:0% +this crazy Professor his his points here + + + align:start position:0% +this crazy Professor his his points here +but we want to to sort of use these to + + align:start position:0% +but we want to to sort of use these to + + + align:start position:0% +but we want to to sort of use these to +sort of think about some of these + + align:start position:0% +sort of think about some of these + + + align:start position:0% +sort of think about some of these +questions uh and you know we're going to + + align:start position:0% +questions uh and you know we're going to + + + align:start position:0% +questions uh and you know we're going to +read some further works but uh somehow + + align:start position:0% +read some further works but uh somehow + + + align:start position:0% +read some further works but uh somehow +how does uh how does this whole subject + + align:start position:0% +how does uh how does this whole subject + + + align:start position:0% +how does uh how does this whole subject +of machines come into this book why why + + align:start position:0% +of machines come into this book why why + + + align:start position:0% +of machines come into this book why why +why are the aians Care One Way or + + align:start position:0% +why are the aians Care One Way or + + + align:start position:0% +why are the aians Care One Way or +Another about + + align:start position:0% +Another about + + + align:start position:0% +Another about +machines and in fact you know as The + + align:start position:0% +machines and in fact you know as The + + + align:start position:0% +machines and in fact you know as The +Story Goes they all rose up against + + align:start position:0% +Story Goes they all rose up against + + + align:start position:0% +Story Goes they all rose up against +machines and destroyed the machines + + align:start position:0% +machines and destroyed the machines + + + align:start position:0% +machines and destroyed the machines +because they were cons conc ered that + + align:start position:0% +because they were cons conc ered that + + + align:start position:0% +because they were cons conc ered that +the machines were evolving into + + align:start position:0% +the machines were evolving into + + + align:start position:0% +the machines were evolving into +something that uh was going to + + align:start position:0% +something that uh was going to + + + align:start position:0% +something that uh was going to +be uh you know they were going to + + align:start position:0% +be uh you know they were going to + + + align:start position:0% +be uh you know they were going to +compete so + + align:start position:0% +compete so + + + align:start position:0% +compete so +uh this this sort of came in so the + + align:start position:0% +uh this this sort of came in so the + + + align:start position:0% +uh this this sort of came in so the +aians uh what's their take what how did + + align:start position:0% +aians uh what's their take what how did + + + align:start position:0% +aians uh what's their take what how did +this all become so urgent for + + align:start position:0% + + + + align:start position:0% + +them + + align:start position:0% +them + + + align:start position:0% +them +I any sense why machines would bother + + align:start position:0% + + + + align:start position:0% + +ionians I'm not sure not sure okay I + + align:start position:0% +ionians I'm not sure not sure okay I + + + align:start position:0% +ionians I'm not sure not sure okay I +mean the Iranians are very concerned + + align:start position:0% +mean the Iranians are very concerned + + + align:start position:0% +mean the Iranians are very concerned +about you know + + align:start position:0% +about you know + + + align:start position:0% +about you know +being as fit as they possibly + + align:start position:0% +being as fit as they possibly + + + align:start position:0% +being as fit as they possibly +can how do machines influence in in this + + align:start position:0% +can how do machines influence in in this + + + align:start position:0% +can how do machines influence in in this +book how how do this book see machines + + align:start position:0% +book how how do this book see machines + + + align:start position:0% +book how how do this book see machines +as influencing + + align:start position:0% +as influencing + + + align:start position:0% +as influencing +Fitness there some kind + + align:start position:0% +Fitness there some kind + + + align:start position:0% +Fitness there some kind +of Yeah the more you have to rely on + + align:start position:0% +of Yeah the more you have to rely on + + + align:start position:0% +of Yeah the more you have to rely on +machines unless you have to rely on your + + align:start position:0% +machines unless you have to rely on your + + + align:start position:0% +machines unless you have to rely on your +own like abilities yeah yeah machines + + align:start position:0% +own like abilities yeah yeah machines + + + align:start position:0% +own like abilities yeah yeah machines +sort of uh as we were saying last class + + align:start position:0% +sort of uh as we were saying last class + + + align:start position:0% +sort of uh as we were saying last class +they kind of uh you know they make up + + align:start position:0% +they kind of uh you know they make up + + + align:start position:0% +they kind of uh you know they make up +for the + + align:start position:0% +for the + + + align:start position:0% +for the +defects that individual aeronian might + + align:start position:0% +defects that individual aeronian might + + + align:start position:0% +defects that individual aeronian might +have so the and aonian philosophy is to + + align:start position:0% +have so the and aonian philosophy is to + + + align:start position:0% +have so the and aonian philosophy is to +uh you know make humans uh absolutely + + align:start position:0% +uh you know make humans uh absolutely + + + align:start position:0% +uh you know make humans uh absolutely +the strongest and best and you know + + align:start position:0% +the strongest and best and you know + + + align:start position:0% +the strongest and best and you know +they're they're sort of self- selecting + + align:start position:0% +they're they're sort of self- selecting + + + align:start position:0% +they're they're sort of self- selecting +for strength and intelligence and so on + + align:start position:0% +for strength and intelligence and so on + + + align:start position:0% +for strength and intelligence and so on +not necessarily for Brilliance because + + align:start position:0% +not necessarily for Brilliance because + + + align:start position:0% +not necessarily for Brilliance because +they're not you know they don't + + align:start position:0% +they're not you know they don't + + + align:start position:0% +they're not you know they don't +like uh individuals who get too far + + align:start position:0% +like uh individuals who get too far + + + align:start position:0% +like uh individuals who get too far +beyond the average the + + align:start position:0% +beyond the average the + + + align:start position:0% +beyond the average the +aonian model and ideal is to fit within + + align:start position:0% +aonian model and ideal is to fit within + + + align:start position:0% +aonian model and ideal is to fit within +the + + align:start position:0% +the + + + align:start position:0% +the +average to be in the middle of the herd + + align:start position:0% +average to be in the middle of the herd + + + align:start position:0% +average to be in the middle of the herd +some + + align:start position:0% +some + + + align:start position:0% +some +place not too far behind and not too far + + align:start position:0% +place not too far behind and not too far + + + align:start position:0% +place not too far behind and not too far +ahead but you know a nice + + align:start position:0% +ahead but you know a nice + + + align:start position:0% +ahead but you know a nice +healthy uh member of the aonian herd if + + align:start position:0% +healthy uh member of the aonian herd if + + + align:start position:0% +healthy uh member of the aonian herd if +you will so machines uh take the uh they + + align:start position:0% +you will so machines uh take the uh they + + + align:start position:0% +you will so machines uh take the uh they +compensate they compensate for certain + + align:start position:0% +compensate they compensate for certain + + + align:start position:0% +compensate they compensate for certain +types of things that uh you know uh + + align:start position:0% +types of things that uh you know uh + + + align:start position:0% +types of things that uh you know uh +individuals might not be able to manage + + align:start position:0% +individuals might not be able to manage + + + align:start position:0% +individuals might not be able to manage +and so in compensating what is that what + + align:start position:0% +and so in compensating what is that what + + + align:start position:0% +and so in compensating what is that what +does that + + align:start position:0% + + + + align:start position:0% + +mean those individuals can have children + + align:start position:0% +mean those individuals can have children + + + align:start position:0% +mean those individuals can have children +and those children will inherit those + + align:start position:0% +and those children will inherit those + + + align:start position:0% +and those children will inherit those +those + + align:start position:0% +those + + + align:start position:0% +those +uh less well-developed or less + + align:start position:0% +uh less well-developed or less + + + align:start position:0% +uh less well-developed or less +competitive features so that's how this + + align:start position:0% +competitive features so that's how this + + + align:start position:0% +competitive features so that's how this +Society works so as I said last time + + align:start position:0% +Society works so as I said last time + + + align:start position:0% +Society works so as I said last time +it's it's uh it's the first kind of uh + + align:start position:0% +it's it's uh it's the first kind of uh + + + align:start position:0% +it's it's uh it's the first kind of uh +uh eugenical soci Society I + + align:start position:0% +uh eugenical soci Society I + + + align:start position:0% +uh eugenical soci Society I +mean the word isn't being used here and + + align:start position:0% +mean the word isn't being used here and + + + align:start position:0% +mean the word isn't being used here and +I don't think Butlers had the word in + + align:start position:0% +I don't think Butlers had the word in + + + align:start position:0% +I don't think Butlers had the word in +his + + align:start position:0% +his + + + align:start position:0% +his +vocabulary but you know it's it's it's + + align:start position:0% +vocabulary but you know it's it's it's + + + align:start position:0% +vocabulary but you know it's it's it's +there and it's being offered uh of + + align:start position:0% +there and it's being offered uh of + + + align:start position:0% +there and it's being offered uh of +course this this Society is being + + align:start position:0% +course this this Society is being + + + align:start position:0% +course this this Society is being +offered as a kind of a satire so it's + + align:start position:0% +offered as a kind of a satire so it's + + + align:start position:0% +offered as a kind of a satire so it's +it's not something he's recommending and + + align:start position:0% +it's not something he's recommending and + + + align:start position:0% +it's not something he's recommending and +you know he's + + align:start position:0% +you know he's + + + align:start position:0% +you know he's +obviously positioned this professor's + + align:start position:0% +obviously positioned this professor's + + + align:start position:0% +obviously positioned this professor's +Treatise the book of the machines + + align:start position:0% +Treatise the book of the machines + + + align:start position:0% +Treatise the book of the machines +how is that position in the book in + + align:start position:0% + + + + align:start position:0% + +Aran you know it's it comes from a + + align:start position:0% +Aran you know it's it comes from a + + + align:start position:0% +Aran you know it's it comes from a +professor in the colleges of + + align:start position:0% +professor in the colleges of + + + align:start position:0% +professor in the colleges of +unreason I didn't have you read all the + + align:start position:0% +unreason I didn't have you read all the + + + align:start position:0% +unreason I didn't have you read all the +chapters but uh this is uh these are + + align:start position:0% +chapters but uh this is uh these are + + + align:start position:0% +chapters but uh this is uh these are +colleges that uh uh Butler used to + + align:start position:0% +colleges that uh uh Butler used to + + + align:start position:0% +colleges that uh uh Butler used to +satire as a satire against camridge + + align:start position:0% +satire as a satire against camridge + + + align:start position:0% +satire as a satire against camridge +because they they uh he he spent a lot + + align:start position:0% +because they they uh he he spent a lot + + + align:start position:0% +because they they uh he he spent a lot +of time learning Latin + + align:start position:0% +of time learning Latin + + + align:start position:0% +of time learning Latin +and uh he couldn't figure out what the + + align:start position:0% +and uh he couldn't figure out what the + + + align:start position:0% +and uh he couldn't figure out what the +Latin was for what the use was going to + + align:start position:0% +Latin was for what the use was going to + + + align:start position:0% +Latin was for what the use was going to +be so in the colleges of + + align:start position:0% +be so in the colleges of + + + align:start position:0% +be so in the colleges of +unreason which uh you know he was making + + align:start position:0% +unreason which uh you know he was making + + + align:start position:0% +unreason which uh you know he was making +fun + + align:start position:0% +fun + + + align:start position:0% +fun +of um the students are taught what they + + align:start position:0% +of um the students are taught what they + + + align:start position:0% +of um the students are taught what they +call a quote hypothetical language and + + align:start position:0% +call a quote hypothetical language and + + + align:start position:0% +call a quote hypothetical language and +the hypothetical language was you know + + align:start position:0% +the hypothetical language was you know + + + align:start position:0% +the hypothetical language was you know +it really didn't have any application + + align:start position:0% +it really didn't have any application + + + align:start position:0% +it really didn't have any application +you just sort of learned it in order to + + align:start position:0% +you just sort of learned it in order to + + + align:start position:0% +you just sort of learned it in order to +learn it uh but not for any particular + + align:start position:0% +learn it uh but not for any particular + + + align:start position:0% +learn it uh but not for any particular +application so he was sort of making fun + + align:start position:0% +application so he was sort of making fun + + + align:start position:0% +application so he was sort of making fun +of the rigorous Latin course that he had + + align:start position:0% +of the rigorous Latin course that he had + + + align:start position:0% +of the rigorous Latin course that he had +to spend and you know he spent a lot of + + align:start position:0% +to spend and you know he spent a lot of + + + align:start position:0% +to spend and you know he spent a lot of +his undergraduate years mastering + + align:start position:0% +his undergraduate years mastering + + + align:start position:0% +his undergraduate years mastering +Latin some other things too but uh a lot + + align:start position:0% +Latin some other things too but uh a lot + + + align:start position:0% +Latin some other things too but uh a lot +of the work that he he felt that a lot + + align:start position:0% +of the work that he he felt that a lot + + + align:start position:0% +of the work that he he felt that a lot +of the work that he had done as an + + align:start position:0% +of the work that he had done as an + + + align:start position:0% +of the work that he had done as an +undergraduate was not really + + align:start position:0% +undergraduate was not really + + + align:start position:0% +undergraduate was not really +particularly useful for + + align:start position:0% +particularly useful for + + + align:start position:0% +particularly useful for +anything and that it was more or less + + align:start position:0% +anything and that it was more or less + + + align:start position:0% +anything and that it was more or less +that he was who's being expected to go + + align:start position:0% +that he was who's being expected to go + + + align:start position:0% +that he was who's being expected to go +go through hoops so uh it was a satire + + align:start position:0% +go through hoops so uh it was a satire + + + align:start position:0% +go through hoops so uh it was a satire +and I think we all have the experience + + align:start position:0% +and I think we all have the experience + + + align:start position:0% +and I think we all have the experience +of sometimes being in classes where in + + align:start position:0% +of sometimes being in classes where in + + + align:start position:0% +of sometimes being in classes where in +University where we wonder what is this + + align:start position:0% +University where we wonder what is this + + + align:start position:0% +University where we wonder what is this +for anyway you know exactly how am I + + align:start position:0% +for anyway you know exactly how am I + + + align:start position:0% +for anyway you know exactly how am I +going to use this so I mean this is a + + align:start position:0% +going to use this so I mean this is a + + + align:start position:0% +going to use this so I mean this is a +this is a you you might say a universal + + align:start position:0% +this is a you you might say a universal + + + align:start position:0% +this is a you you might say a universal +undergraduate experience of encountering + + align:start position:0% +undergraduate experience of encountering + + + align:start position:0% +undergraduate experience of encountering +certain types of things that you really + + align:start position:0% +certain types of things that you really + + + align:start position:0% +certain types of things that you really +wonder you know what's the value of + + align:start position:0% +wonder you know what's the value of + + + align:start position:0% +wonder you know what's the value of +this so so he's uh as I said this is a + + align:start position:0% +this so so he's uh as I said this is a + + + align:start position:0% +this so so he's uh as I said this is a +this book is a satire it it's really in + + align:start position:0% +this book is a satire it it's really in + + + align:start position:0% +this book is a satire it it's really in +many ways like candid only you know it's + + align:start position:0% +many ways like candid only you know it's + + + align:start position:0% +many ways like candid only you know it's +it's another + + align:start position:0% +it's another + + + align:start position:0% +it's another +generation a couple of generations down + + align:start position:0% +generation a couple of generations down + + + align:start position:0% +generation a couple of generations down +the line so it's much more in tune with + + align:start position:0% +the line so it's much more in tune with + + + align:start position:0% +the line so it's much more in tune with +the 19th century post darwinian + + align:start position:0% +the 19th century post darwinian + + + align:start position:0% +the 19th century post darwinian +world so this Treatise that that uh + + align:start position:0% +world so this Treatise that that uh + + + align:start position:0% +world so this Treatise that that uh +Chris was just giving us an introduction + + align:start position:0% +Chris was just giving us an introduction + + + align:start position:0% +Chris was just giving us an introduction +to uh is really A Treatise written by a + + align:start position:0% +to uh is really A Treatise written by a + + + align:start position:0% +to uh is really A Treatise written by a +professor who is a member of uh this + + align:start position:0% +professor who is a member of uh this + + + align:start position:0% +professor who is a member of uh this +this college of En reason and you know + + align:start position:0% +this college of En reason and you know + + + align:start position:0% +this college of En reason and you know +he's sort of giving a + + align:start position:0% +he's sort of giving a + + + align:start position:0% +he's sort of giving a +history um and he's articulating a + + align:start position:0% +history um and he's articulating a + + + align:start position:0% +history um and he's articulating a +theory of why and and this is A Treatise + + align:start position:0% +theory of why and and this is A Treatise + + + align:start position:0% +theory of why and and this is A Treatise +uh that convinced the Iranians to go up + + align:start position:0% +uh that convinced the Iranians to go up + + + align:start position:0% +uh that convinced the Iranians to go up +against machines and to battle against + + align:start position:0% +against machines and to battle against + + + align:start position:0% +against machines and to battle against +them and so they became the sort of an + + align:start position:0% +them and so they became the sort of an + + + align:start position:0% +them and so they became the sort of an +anti-machine + + align:start position:0% +anti-machine + + + align:start position:0% +anti-machine +uh uh group and they fought with the + + align:start position:0% +uh uh group and they fought with the + + + align:start position:0% +uh uh group and they fought with the +supporters of the machines and the + + align:start position:0% +supporters of the machines and the + + + align:start position:0% +supporters of the machines and the +anti-machine group + + align:start position:0% +anti-machine group + + + align:start position:0% +anti-machine group +W and so U and this is A Treatise that + + align:start position:0% +W and so U and this is A Treatise that + + + align:start position:0% +W and so U and this is A Treatise that +they that convinced them to go to war + + align:start position:0% +they that convinced them to go to war + + + align:start position:0% +they that convinced them to go to war +against all people who would uh use + + align:start position:0% +against all people who would uh use + + + align:start position:0% +against all people who would uh use +machines and that's why Butler uh the + + align:start position:0% +machines and that's why Butler uh the + + + align:start position:0% +machines and that's why Butler uh the +that's why the uh Butler's uh narrator + + align:start position:0% +that's why the uh Butler's uh narrator + + + align:start position:0% +that's why the uh Butler's uh narrator +in this + + align:start position:0% +in this + + + align:start position:0% +in this +book is jailed because because they find + + align:start position:0% +book is jailed because because they find + + + align:start position:0% +book is jailed because because they find +the watch that's that's what gets them + + align:start position:0% +the watch that's that's what gets them + + + align:start position:0% +the watch that's that's what gets them +into trouble with this these aonian okay + + align:start position:0% +into trouble with this these aonian okay + + + align:start position:0% +into trouble with this these aonian okay +so that's that's sort of the framework + + align:start position:0% +so that's that's sort of the framework + + + align:start position:0% +so that's that's sort of the framework +for this this + + align:start position:0% +for this this + + + align:start position:0% +for this this +piece okay so uh let me uh let me just + + align:start position:0% +piece okay so uh let me uh let me just + + + align:start position:0% +piece okay so uh let me uh let me just +say a little bit about the background + + align:start position:0% +say a little bit about the background + + + align:start position:0% +say a little bit about the background +because this book is in the middle of a + + align:start position:0% +because this book is in the middle of a + + + align:start position:0% +because this book is in the middle of a +you know there there's a very large + + align:start position:0% +you know there there's a very large + + + align:start position:0% +you know there there's a very large +context for some of the things that uh + + align:start position:0% +context for some of the things that uh + + + align:start position:0% +context for some of the things that uh +are being explored in the book and um I + + align:start position:0% +are being explored in the book and um I + + + align:start position:0% +are being explored in the book and um I +sent you out some slides and just say a + + align:start position:0% +sent you out some slides and just say a + + + align:start position:0% +sent you out some slides and just say a +few things about these but um uh you + + align:start position:0% +few things about these but um uh you + + + align:start position:0% +few things about these but um uh you +know the the existence of machines in + + align:start position:0% +know the the existence of machines in + + + align:start position:0% +know the the existence of machines in +Butler's day in in the 18 in the mid + + align:start position:0% +Butler's day in in the 18 in the mid + + + align:start position:0% +Butler's day in in the 18 in the mid +1800s machines had proliferated in many + + align:start position:0% +1800s machines had proliferated in many + + + align:start position:0% +1800s machines had proliferated in many +many different + + align:start position:0% +many different + + + align:start position:0% +many different +ways uh you know steam engines were + + align:start position:0% +ways uh you know steam engines were + + + align:start position:0% +ways uh you know steam engines were +quite common that's that's what he's + + align:start position:0% +quite common that's that's what he's + + + align:start position:0% +quite common that's that's what he's +referring to with uh when he talks about + + align:start position:0% +referring to with uh when he talks about + + + align:start position:0% +referring to with uh when he talks about +the vapor engine here uh and there had + + align:start position:0% +the vapor engine here uh and there had + + + align:start position:0% +the vapor engine here uh and there had +been an incredible amount of development + + align:start position:0% +been an incredible amount of development + + + align:start position:0% +been an incredible amount of development +of uh technology around Steam power I + + align:start position:0% +of uh technology around Steam power I + + + align:start position:0% +of uh technology around Steam power I +mean steam power was amazing addition to + + align:start position:0% +mean steam power was amazing addition to + + + align:start position:0% +mean steam power was amazing addition to +uh the possibilities for uh + + align:start position:0% +uh the possibilities for uh + + + align:start position:0% +uh the possibilities for uh +for using and dis for applying motive + + align:start position:0% +for using and dis for applying motive + + + align:start position:0% +for using and dis for applying motive +Force to various types of + + align:start position:0% +Force to various types of + + + align:start position:0% +Force to various types of +tasks and uh it was uh uh steam power + + align:start position:0% +tasks and uh it was uh uh steam power + + + align:start position:0% +tasks and uh it was uh uh steam power +was widely widely + + align:start position:0% +was widely widely + + + align:start position:0% +was widely widely +used um in in uh the Victorian + + align:start position:0% +used um in in uh the Victorian + + + align:start position:0% +used um in in uh the Victorian +era and it um it led to the development + + align:start position:0% +era and it um it led to the development + + + align:start position:0% +era and it um it led to the development +of all sorts of things including U the + + align:start position:0% +of all sorts of things including U the + + + align:start position:0% +of all sorts of things including U the +first + + align:start position:0% +first + + + align:start position:0% +first +Railways and as most people know the + + align:start position:0% +Railways and as most people know the + + + align:start position:0% +Railways and as most people know the +railways really began to develop in a + + align:start position:0% +railways really began to develop in a + + + align:start position:0% +railways really began to develop in a +big way in the + + align:start position:0% +big way in the + + + align:start position:0% +big way in the +1800s uh both in England in the + + align:start position:0% +1800s uh both in England in the + + + align:start position:0% +1800s uh both in England in the +US but uh in England uh the railway + + align:start position:0% +US but uh in England uh the railway + + + align:start position:0% +US but uh in England uh the railway +system uh just exploded it just + + align:start position:0% +system uh just exploded it just + + + align:start position:0% +system uh just exploded it just +developed and so much so that people + + align:start position:0% +developed and so much so that people + + + align:start position:0% +developed and so much so that people +began to feel you know railways were uh + + align:start position:0% +began to feel you know railways were uh + + + align:start position:0% +began to feel you know railways were uh +uh rather becoming rather + + align:start position:0% +uh rather becoming rather + + + align:start position:0% +uh rather becoming rather +intrusive Butler himself the + + align:start position:0% +intrusive Butler himself the + + + align:start position:0% +intrusive Butler himself the +author was a a tremendous user of + + align:start position:0% +author was a a tremendous user of + + + align:start position:0% +author was a a tremendous user of +Railways he traveled all over England + + align:start position:0% +Railways he traveled all over England + + + align:start position:0% +Railways he traveled all over England +and all over uh Europe on + + align:start position:0% +and all over uh Europe on + + + align:start position:0% +and all over uh Europe on +Railways um before that you had to hire + + align:start position:0% +Railways um before that you had to hire + + + align:start position:0% +Railways um before that you had to hire +a trap with a horse or something like + + align:start position:0% +a trap with a horse or something like + + + align:start position:0% +a trap with a horse or something like +that and uh in the years that Butler + + align:start position:0% +that and uh in the years that Butler + + + align:start position:0% +that and uh in the years that Butler +lived in New Zealand land a new Railway + + align:start position:0% +lived in New Zealand land a new Railway + + + align:start position:0% +lived in New Zealand land a new Railway +was put + + align:start position:0% +was put + + + align:start position:0% +was put +in uh to bring uh goods from the harbor + + align:start position:0% +in uh to bring uh goods from the harbor + + + align:start position:0% +in uh to bring uh goods from the harbor +up to the city of Christ Church where + + align:start position:0% +up to the city of Christ Church where + + + align:start position:0% +up to the city of Christ Church where +Butler went to on the south island of + + align:start position:0% +Butler went to on the south island of + + + align:start position:0% +Butler went to on the south island of +New Zealand so and he knew uh he knew uh + + align:start position:0% +New Zealand so and he knew uh he knew uh + + + align:start position:0% +New Zealand so and he knew uh he knew uh +the gentleman who developed the railway + + align:start position:0% +the gentleman who developed the railway + + + align:start position:0% +the gentleman who developed the railway +system and was one of the first people + + align:start position:0% +system and was one of the first people + + + align:start position:0% +system and was one of the first people +to ride on one of the first rides of the + + align:start position:0% +to ride on one of the first rides of the + + + align:start position:0% +to ride on one of the first rides of the +Railway so there is this sense of the + + align:start position:0% +Railway so there is this sense of the + + + align:start position:0% +Railway so there is this sense of the +presence of machines + + align:start position:0% +presence of machines + + + align:start position:0% +presence of machines +becoming rather + + align:start position:0% +becoming rather + + + align:start position:0% +becoming rather +extensive + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +uh there were other things happening in + + align:start position:0% +uh there were other things happening in + + + align:start position:0% +uh there were other things happening in +the in the time and he refers to some of + + align:start position:0% +the in the time and he refers to some of + + + align:start position:0% +the in the time and he refers to some of +this so I'm just I'm just uh uh giving + + align:start position:0% +this so I'm just I'm just uh uh giving + + + align:start position:0% +this so I'm just I'm just uh uh giving +you some background on some of he he + + align:start position:0% +you some background on some of he he + + + align:start position:0% +you some background on some of he he +talks about the power of machines in in + + align:start position:0% +talks about the power of machines in in + + + align:start position:0% +talks about the power of machines in in +in in in the book of the + + align:start position:0% +in in in the book of the + + + align:start position:0% +in in in the book of the +machines in aan there's a there's a + + align:start position:0% +machines in aan there's a there's a + + + align:start position:0% +machines in aan there's a there's a +mention to the power machines for + + align:start position:0% +mention to the power machines for + + + align:start position:0% +mention to the power machines for +calculating and uh + + align:start position:0% +calculating and uh + + + align:start position:0% +calculating and uh +Charles babage anybody here ever hear of + + align:start position:0% +Charles babage anybody here ever hear of + + + align:start position:0% +Charles babage anybody here ever hear of +Charles + + align:start position:0% +Charles + + + align:start position:0% +Charles +babage he a great Victorian thinker + + align:start position:0% +babage he a great Victorian thinker + + + align:start position:0% +babage he a great Victorian thinker +somebody who uh Darwin knew Darwin knew + + align:start position:0% +somebody who uh Darwin knew Darwin knew + + + align:start position:0% +somebody who uh Darwin knew Darwin knew +Charles + + align:start position:0% +Charles + + + align:start position:0% +Charles +babage and uh babage was known as uh the + + align:start position:0% +babage and uh babage was known as uh the + + + align:start position:0% +babage and uh babage was known as uh the +I mean he was a genius he was a + + align:start position:0% +I mean he was a genius he was a + + + align:start position:0% +I mean he was a genius he was a +wonderful + + align:start position:0% +wonderful + + + align:start position:0% +wonderful +incredible uh fertile mind just uh + + align:start position:0% +incredible uh fertile mind just uh + + + align:start position:0% +incredible uh fertile mind just uh +thinking about difference engines + + align:start position:0% +thinking about difference engines + + + align:start position:0% +thinking about difference engines +calculating engines and how to use + + align:start position:0% +calculating engines and how to use + + + align:start position:0% +calculating engines and how to use +mechanical Power + + align:start position:0% +mechanical Power + + + align:start position:0% +mechanical Power +to do numerical + + align:start position:0% +to do numerical + + + align:start position:0% +to do numerical +calculations and the whole notion that + + align:start position:0% +calculations and the whole notion that + + + align:start position:0% +calculations and the whole notion that +uh something like this could be + + align:start position:0% +uh something like this could be + + + align:start position:0% +uh something like this could be +um if this + + align:start position:0% +um if this + + + align:start position:0% +um if this +will well that's not the one I + + align:start position:0% +will well that's not the one I + + + align:start position:0% +will well that's not the one I +wanted + + align:start position:0% +wanted + + + align:start position:0% +wanted +um okay well I I I sent you an inset + + align:start position:0% +um okay well I I I sent you an inset + + + align:start position:0% +um okay well I I I sent you an inset +this machine um this Difference Engine + + align:start position:0% +this machine um this Difference Engine + + + align:start position:0% +this machine um this Difference Engine +uh babage designed and and + + align:start position:0% +uh babage designed and and + + + align:start position:0% +uh babage designed and and +sort of described how it should be built + + align:start position:0% +sort of described how it should be built + + + align:start position:0% +sort of described how it should be built +but he did not have the resources to + + align:start position:0% +but he did not have the resources to + + + align:start position:0% +but he did not have the resources to +build it so it was always a big question + + align:start position:0% +build it so it was always a big question + + + align:start position:0% +build it so it was always a big question +well do babies's machines really work + + align:start position:0% +well do babies's machines really work + + + align:start position:0% +well do babies's machines really work +and uh I sent you a clip in this so if + + align:start position:0% +and uh I sent you a clip in this so if + + + align:start position:0% +and uh I sent you a clip in this so if +you go back to the slides of uh a uh + + align:start position:0% +you go back to the slides of uh a uh + + + align:start position:0% +you go back to the slides of uh a uh +Professor out University of California + + align:start position:0% +Professor out University of California + + + align:start position:0% +Professor out University of California +Berkeley who actually built babies's + + align:start position:0% +Berkeley who actually built babies's + + + align:start position:0% +Berkeley who actually built babies's +machine and he has a + + align:start position:0% +machine and he has a + + + align:start position:0% +machine and he has a +actual a grinder for it and he actually + + align:start position:0% +actual a grinder for it and he actually + + + align:start position:0% +actual a grinder for it and he actually +had a recent conference demoed it and uh + + align:start position:0% +had a recent conference demoed it and uh + + + align:start position:0% +had a recent conference demoed it and uh +his uh Difference Engine Works quite + + align:start position:0% +his uh Difference Engine Works quite + + + align:start position:0% +his uh Difference Engine Works quite +beautifully so he actually built it to + + align:start position:0% +beautifully so he actually built it to + + + align:start position:0% +beautifully so he actually built it to +scale he babby didn't have the resources + + align:start position:0% +scale he babby didn't have the resources + + + align:start position:0% +scale he babby didn't have the resources +and he was one of these P people who + + align:start position:0% +and he was one of these P people who + + + align:start position:0% +and he was one of these P people who +worked and worked and worked and was + + align:start position:0% +worked and worked and worked and was + + + align:start position:0% +worked and worked and worked and was +always always short of money and never + + align:start position:0% +always always short of money and never + + + align:start position:0% +always always short of money and never +had quite enough to carry out all his + + align:start position:0% +had quite enough to carry out all his + + + align:start position:0% +had quite enough to carry out all his +different uh schemes but what he did + + align:start position:0% +different uh schemes but what he did + + + align:start position:0% +different uh schemes but what he did +show is machines Mechanical + + align:start position:0% +show is machines Mechanical + + + align:start position:0% +show is machines Mechanical +Devices could be used to process things + + align:start position:0% +Devices could be used to process things + + + align:start position:0% +Devices could be used to process things +that we think of as + + align:start position:0% +that we think of as + + + align:start position:0% +that we think of as +thought and so again this this notion of + + align:start position:0% +thought and so again this this notion of + + + align:start position:0% +thought and so again this this notion of +uh the mechanical + + align:start position:0% +uh the mechanical + + + align:start position:0% +uh the mechanical +world and is + + align:start position:0% +world and is + + + align:start position:0% +world and is +capabilities among many many victorians + + align:start position:0% +capabilities among many many victorians + + + align:start position:0% +capabilities among many many victorians +19th century people had become uh uh a + + align:start position:0% +19th century people had become uh uh a + + + align:start position:0% +19th century people had become uh uh a +very uh powerful and and uh + + align:start position:0% +very uh powerful and and uh + + + align:start position:0% +very uh powerful and and uh +compelling + + align:start position:0% +compelling + + + align:start position:0% +compelling +idea and people like + + align:start position:0% +idea and people like + + + align:start position:0% +idea and people like +Darwin and the technical + + align:start position:0% +Darwin and the technical + + + align:start position:0% +Darwin and the technical +um + + align:start position:0% +um + + + align:start position:0% +um +Elites were were quite familiar with + + align:start position:0% +Elites were were quite familiar with + + + align:start position:0% +Elites were were quite familiar with +with these + + align:start position:0% +with these + + + align:start position:0% +with these +possibilities and also these Notions of + + align:start position:0% +possibilities and also these Notions of + + + align:start position:0% +possibilities and also these Notions of +mechanical and the the the the the + + align:start position:0% +mechanical and the the the the the + + + align:start position:0% +mechanical and the the the the the +prevalence of the mechanical world and + + align:start position:0% +prevalence of the mechanical world and + + + align:start position:0% +prevalence of the mechanical world and +its its uh capabilities uh were not just + + align:start position:0% +its its uh capabilities uh were not just + + + align:start position:0% +its its uh capabilities uh were not just +Elites there were you know many many + + align:start position:0% +Elites there were you know many many + + + align:start position:0% +Elites there were you know many many +people in the middle class and in the + + align:start position:0% +people in the middle class and in the + + + align:start position:0% +people in the middle class and in the +working class + + align:start position:0% +working class + + + align:start position:0% +working class +were in the same environments and + + align:start position:0% +were in the same environments and + + + align:start position:0% +were in the same environments and +understood that these forms of progress + + align:start position:0% +understood that these forms of progress + + + align:start position:0% +understood that these forms of progress +were uh were uh Trend setting and and + + align:start position:0% +were uh were uh Trend setting and and + + + align:start position:0% +were uh were uh Trend setting and and +Incredibly important um and transforming + + align:start position:0% +Incredibly important um and transforming + + + align:start position:0% +Incredibly important um and transforming +the uh transforming the way people + + align:start position:0% +the uh transforming the way people + + + align:start position:0% +the uh transforming the way people +lived uh there were a number of people + + align:start position:0% +lived uh there were a number of people + + + align:start position:0% +lived uh there were a number of people +of bab's machines uh ad LEL uh Lord + + align:start position:0% +of bab's machines uh ad LEL uh Lord + + + align:start position:0% +of bab's machines uh ad LEL uh Lord +Byron's daughter the poet's daughter um + + align:start position:0% +Byron's daughter the poet's daughter um + + + align:start position:0% +Byron's daughter the poet's daughter um +she was one of the first programmers she + + align:start position:0% +she was one of the first programmers she + + + align:start position:0% +she was one of the first programmers she +was a mathematician and she wrote + + align:start position:0% +was a mathematician and she wrote + + + align:start position:0% +was a mathematician and she wrote +program for uh babbage's machines and + + align:start position:0% +program for uh babbage's machines and + + + align:start position:0% +program for uh babbage's machines and +she understood the whole notion of + + align:start position:0% +she understood the whole notion of + + + align:start position:0% +she understood the whole notion of +programming the idea that you would + + align:start position:0% +programming the idea that you would + + + align:start position:0% +programming the idea that you would +create instructions for machines then + + align:start position:0% +create instructions for machines then + + + align:start position:0% +create instructions for machines then +you could feed them into machines and + + align:start position:0% +you could feed them into machines and + + + align:start position:0% +you could feed them into machines and +machines could carry out your + + align:start position:0% +machines could carry out your + + + align:start position:0% +machines could carry out your +instructions so when we when we think of + + align:start position:0% +instructions so when we when we think of + + + align:start position:0% +instructions so when we when we think of +these uh these ravings of this professor + + align:start position:0% +these uh these ravings of this professor + + + align:start position:0% +these uh these ravings of this professor +here keep in mind that uh Butler's aware + + align:start position:0% +here keep in mind that uh Butler's aware + + + align:start position:0% +here keep in mind that uh Butler's aware +of all this world and you know he's not + + align:start position:0% +of all this world and you know he's not + + + align:start position:0% +of all this world and you know he's not +just kind of coming up out of nowhere + + align:start position:0% +just kind of coming up out of nowhere + + + align:start position:0% +just kind of coming up out of nowhere +with these these + + align:start position:0% +with these these + + + align:start position:0% +with these these +Notions uh but he's using them also in a + + align:start position:0% +Notions uh but he's using them also in a + + + align:start position:0% +Notions uh but he's using them also in a +kind of + + align:start position:0% +kind of + + + align:start position:0% +kind of +U you know it's it's a sort of satire + + align:start position:0% +U you know it's it's a sort of satire + + + align:start position:0% +U you know it's it's a sort of satire +he's not being totally serious but he's + + align:start position:0% +he's not being totally serious but he's + + + align:start position:0% +he's not being totally serious but he's +also you know trying to tweak your + + align:start position:0% +also you know trying to tweak your + + + align:start position:0% +also you know trying to tweak your +imagination into thinking about it and + + align:start position:0% +imagination into thinking about it and + + + align:start position:0% +imagination into thinking about it and +that's what the book for it's it's it's + + align:start position:0% +that's what the book for it's it's it's + + + align:start position:0% +that's what the book for it's it's it's +not to tell you that this is exactly + + align:start position:0% +not to tell you that this is exactly + + + align:start position:0% +not to tell you that this is exactly +what's going to happen it's just to make + + align:start position:0% +what's going to happen it's just to make + + + align:start position:0% +what's going to happen it's just to make +you think about it and think a little + + align:start position:0% +you think about it and think a little + + + align:start position:0% +you think about it and think a little +more deeply and get beyond your everyday + + align:start position:0% +more deeply and get beyond your everyday + + + align:start position:0% +more deeply and get beyond your everyday +assumptions and that's the spirit of the + + align:start position:0% +assumptions and that's the spirit of the + + + align:start position:0% +assumptions and that's the spirit of the +book so he says + + align:start position:0% + + + + align:start position:0% + +um at the start of chapter one uh of the + + align:start position:0% +um at the start of chapter one uh of the + + + align:start position:0% +um at the start of chapter one uh of the +uh chapter the first chapter on the book + + align:start position:0% +uh chapter the first chapter on the book + + + align:start position:0% +uh chapter the first chapter on the book +of the machines it runs + + align:start position:0% +of the machines it runs + + + align:start position:0% +of the machines it runs +through three chapters he says uh there + + align:start position:0% +through three chapters he says uh there + + + align:start position:0% +through three chapters he says uh there +was a time when the Earth was was to all + + align:start position:0% +was a time when the Earth was was to all + + + align:start position:0% +was a time when the Earth was was to all +appearance utterly destitute both of + + align:start position:0% +appearance utterly destitute both of + + + align:start position:0% +appearance utterly destitute both of +animal and vegetable life and when + + align:start position:0% +animal and vegetable life and when + + + align:start position:0% +animal and vegetable life and when +according to the opinion of our best + + align:start position:0% +according to the opinion of our best + + + align:start position:0% +according to the opinion of our best +philosophers it was simply a hot round + + align:start position:0% +philosophers it was simply a hot round + + + align:start position:0% +philosophers it was simply a hot round +ball with a crust gradually + + align:start position:0% +ball with a crust gradually + + + align:start position:0% +ball with a crust gradually +cooling now if a human being had existed + + align:start position:0% +cooling now if a human being had existed + + + align:start position:0% +cooling now if a human being had existed +while the Earth was in this state and + + align:start position:0% +while the Earth was in this state and + + + align:start position:0% +while the Earth was in this state and +had been allowed to see it as though it + + align:start position:0% +had been allowed to see it as though it + + + align:start position:0% +had been allowed to see it as though it +were some other world with which he had + + align:start position:0% +were some other world with which he had + + + align:start position:0% +were some other world with which he had +no concern and if at the same time he + + align:start position:0% +no concern and if at the same time he + + + align:start position:0% +no concern and if at the same time he +were entirely ignorant of all physical + + align:start position:0% +were entirely ignorant of all physical + + + align:start position:0% +were entirely ignorant of all physical +science would he not have pronounced it + + align:start position:0% +science would he not have pronounced it + + + align:start position:0% +science would he not have pronounced it +in possible that creatures possessed of + + align:start position:0% +in possible that creatures possessed of + + + align:start position:0% +in possible that creatures possessed of +anything like + + align:start position:0% +anything like + + + align:start position:0% +anything like +Consciousness should be evolved from the + + align:start position:0% +Consciousness should be evolved from the + + + align:start position:0% +Consciousness should be evolved from the +seeming Cinder which he was + + align:start position:0% +seeming Cinder which he was + + + align:start position:0% +seeming Cinder which he was +beholding would he not have denied that + + align:start position:0% +beholding would he not have denied that + + + align:start position:0% +beholding would he not have denied that +it contained any potentiality of + + align:start position:0% +it contained any potentiality of + + + align:start position:0% +it contained any potentiality of +Consciousness yet in the course of time + + align:start position:0% +Consciousness yet in the course of time + + + align:start position:0% +Consciousness yet in the course of time +Consciousness + + align:start position:0% +Consciousness + + + align:start position:0% +Consciousness +came is it not possible then that there + + align:start position:0% +came is it not possible then that there + + + align:start position:0% +came is it not possible then that there +may be even yet new channels dug out for + + align:start position:0% +may be even yet new channels dug out for + + + align:start position:0% +may be even yet new channels dug out for +Consciousness though we can detect no + + align:start position:0% +Consciousness though we can detect no + + + align:start position:0% +Consciousness though we can detect no +signs of them at + + align:start position:0% + + + + align:start position:0% + +present + + align:start position:0% +present + + + align:start position:0% +present +so what's he + + align:start position:0% +so what's he + + + align:start position:0% +so what's he +saying I mean how do we understand this + + align:start position:0% +saying I mean how do we understand this + + + align:start position:0% +saying I mean how do we understand this +what does it + + align:start position:0% + + + + align:start position:0% + +mean Jake what do you + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +think he says that Consciousness no one + + align:start position:0% +think he says that Consciousness no one + + + align:start position:0% +think he says that Consciousness no one +would imagine consciousness looking at + + align:start position:0% +would imagine consciousness looking at + + + align:start position:0% +would imagine consciousness looking at +the Earth before just as it was at the + + align:start position:0% +the Earth before just as it was at the + + + align:start position:0% +the Earth before just as it was at the +very earliest stage so well he's he's + + align:start position:0% +very earliest stage so well he's he's + + + align:start position:0% +very earliest stage so well he's he's +saying that if you look at the very + + align:start position:0% +saying that if you look at the very + + + align:start position:0% +saying that if you look at the very +stages not only is there no life at all + + align:start position:0% +stages not only is there no life at all + + + align:start position:0% +stages not only is there no life at all +MH but if you think you think of + + align:start position:0% +MH but if you think you think of + + + align:start position:0% +MH but if you think you think of +Consciousness as like a it's an advanced + + align:start position:0% +Consciousness as like a it's an advanced + + + align:start position:0% +Consciousness as like a it's an advanced +concept really and you look at the very + + align:start position:0% +concept really and you look at the very + + + align:start position:0% +concept really and you look at the very +basic Earth no life right you think well + + align:start position:0% +basic Earth no life right you think well + + + align:start position:0% +basic Earth no life right you think well +maybe some basic life + + align:start position:0% +maybe some basic life + + + align:start position:0% +maybe some basic life +bacteria viruses I mean the real basic + + align:start position:0% +bacteria viruses I mean the real basic + + + align:start position:0% +bacteria viruses I mean the real basic +stuff come out of that + + align:start position:0% +stuff come out of that + + + align:start position:0% +stuff come out of that +maybe but you think about complex things + + align:start position:0% +maybe but you think about complex things + + + align:start position:0% +maybe but you think about complex things +like self-awareness and cognizance and I + + align:start position:0% +like self-awareness and cognizance and I + + + align:start position:0% +like self-awareness and cognizance and I +mean you don't you really don't see that + + align:start position:0% +mean you don't you really don't see that + + + align:start position:0% +mean you don't you really don't see that +coming that's that's what his point is + + align:start position:0% +coming that's that's what his point is + + + align:start position:0% +coming that's that's what his point is +his point is that these complex things + + align:start position:0% +his point is that these complex things + + + align:start position:0% +his point is that these complex things +aren't justop s popping up all over the + + align:start position:0% +aren't justop s popping up all over the + + + align:start position:0% +aren't justop s popping up all over the +place that it just doesn't make sense to + + align:start position:0% +place that it just doesn't make sense to + + + align:start position:0% +place that it just doesn't make sense to +see that happen Okay and then I think he + + align:start position:0% +see that happen Okay and then I think he + + + align:start position:0% +see that happen Okay and then I think he +also leaves it open + + align:start position:0% +also leaves it open + + + align:start position:0% +also leaves it open +for kind of like the + + align:start position:0% +for kind of like the + + + align:start position:0% +for kind of like the +unfathomable you know Beyond like if our + + align:start position:0% +unfathomable you know Beyond like if our + + + align:start position:0% +unfathomable you know Beyond like if our +Consciousness came out of this nothing + + align:start position:0% +Consciousness came out of this nothing + + + align:start position:0% +Consciousness came out of this nothing +this you know ball of like + + align:start position:0% +this you know ball of like + + + align:start position:0% +this you know ball of like +magma then then in another you know + + align:start position:0% +magma then then in another you know + + + align:start position:0% +magma then then in another you know +however many Millennia what could + + align:start position:0% +however many Millennia what could + + + align:start position:0% +however many Millennia what could +Consciousness evolve to what's the next + + align:start position:0% +Consciousness evolve to what's the next + + + align:start position:0% +Consciousness evolve to what's the next +level of + + align:start position:0% +level of + + + align:start position:0% +level of +Consciousness yeah it's pretty + + align:start position:0% +Consciousness yeah it's pretty + + + align:start position:0% +Consciousness yeah it's pretty +impressive that uh you know I + + align:start position:0% +impressive that uh you know I + + + align:start position:0% +impressive that uh you know I +mean from a naturalistic point of view + + align:start position:0% +mean from a naturalistic point of view + + + align:start position:0% +mean from a naturalistic point of view +it's pretty impressive that uh + + align:start position:0% +it's pretty impressive that uh + + + align:start position:0% +it's pretty impressive that uh +self-awareness Consciousness and things + + align:start position:0% +self-awareness Consciousness and things + + + align:start position:0% +self-awareness Consciousness and things +of those sorts + + align:start position:0% +of those sorts + + + align:start position:0% +of those sorts +uh that level of activity emerged + + align:start position:0% +uh that level of activity emerged + + + align:start position:0% +uh that level of activity emerged +from a planet that was uh at least in + + align:start position:0% +from a planet that was uh at least in + + + align:start position:0% +from a planet that was uh at least in +the scientific framework of + + align:start position:0% +the scientific framework of + + + align:start position:0% +the scientific framework of +understanding pretty much a Barren + + align:start position:0% +understanding pretty much a Barren + + + align:start position:0% +understanding pretty much a Barren +planet with nothing on it so this notion + + align:start position:0% +planet with nothing on it so this notion + + + align:start position:0% +planet with nothing on it so this notion +of progress things I mean you know this + + align:start position:0% +of progress things I mean you know this + + + align:start position:0% +of progress things I mean you know this +this notion that change takes place + + align:start position:0% +this notion that change takes place + + + align:start position:0% +this notion that change takes place +somehow in this endlessly iterative + + align:start position:0% +somehow in this endlessly iterative + + + align:start position:0% +somehow in this endlessly iterative +process that's the key here + + align:start position:0% +process that's the key here + + + align:start position:0% +process that's the key here +and his his his application of it to + + align:start position:0% +and his his his application of it to + + + align:start position:0% +and his his his application of it to +machines can make us think back to what + + align:start position:0% +machines can make us think back to what + + + align:start position:0% +machines can make us think back to what +is it special about natural selection + + align:start position:0% +is it special about natural selection + + + align:start position:0% +is it special about natural selection +what is it about the selection + + align:start position:0% +what is it about the selection + + + align:start position:0% +what is it about the selection +process that delivers something not just + + align:start position:0% +process that delivers something not just + + + align:start position:0% +process that delivers something not just +the + + align:start position:0% +the + + + align:start position:0% +the +same but it + + align:start position:0% +same but it + + + align:start position:0% +same but it +delivers incremental change David well I + + align:start position:0% +delivers incremental change David well I + + + align:start position:0% +delivers incremental change David well I +think it's interesting that like if if + + align:start position:0% +think it's interesting that like if if + + + align:start position:0% +think it's interesting that like if if +something doesn't work if a mutation + + align:start position:0% +something doesn't work if a mutation + + + align:start position:0% +something doesn't work if a mutation +doesn't work if a change doesn't work it + + align:start position:0% +doesn't work if a change doesn't work it + + + align:start position:0% +doesn't work if a change doesn't work it +just disappears you know it it isn't + + align:start position:0% +just disappears you know it it isn't + + + align:start position:0% +just disappears you know it it isn't +allowed to progress at all + + align:start position:0% +allowed to progress at all + + + align:start position:0% +allowed to progress at all +um so I mean it keeps that from + + align:start position:0% +um so I mean it keeps that from + + + align:start position:0% +um so I mean it keeps that from +stagnating and it and it always drives + + align:start position:0% +stagnating and it and it always drives + + + align:start position:0% +stagnating and it and it always drives +something forward whether it's more + + align:start position:0% +something forward whether it's more + + + align:start position:0% +something forward whether it's more +complex and more you know works + + align:start position:0% +complex and more you know works + + + align:start position:0% +complex and more you know works +better so yeah so when you say drive + + align:start position:0% +better so yeah so when you say drive + + + align:start position:0% +better so yeah so when you say drive +forward what you're really referring to + + align:start position:0% +forward what you're really referring to + + + align:start position:0% +forward what you're really referring to +is the fact that you know there is a + + align:start position:0% +is the fact that you know there is a + + + align:start position:0% +is the fact that you know there is a +what we might call a figure of Merit or + + align:start position:0% +what we might call a figure of Merit or + + + align:start position:0% +what we might call a figure of Merit or +there's some concept of you know + + align:start position:0% +there's some concept of you know + + + align:start position:0% +there's some concept of you know +something can have + + align:start position:0% +something can have + + + align:start position:0% +something can have +more + + align:start position:0% +more + + + align:start position:0% +more +adaptation than something else so there + + align:start position:0% +adaptation than something else so there + + + align:start position:0% +adaptation than something else so there +there there's an incremental advantage + + align:start position:0% +there there's an incremental advantage + + + align:start position:0% +there there's an incremental advantage +or incremental there's a differential + + align:start position:0% +or incremental there's a differential + + + align:start position:0% +or incremental there's a differential +that + + align:start position:0% +that + + + align:start position:0% +that +favors A or B over a so there's some + + align:start position:0% +favors A or B over a so there's some + + + align:start position:0% +favors A or B over a so there's some +differential and through this iterative + + align:start position:0% +differential and through this iterative + + + align:start position:0% +differential and through this iterative +process and then + + align:start position:0% +process and then + + + align:start position:0% +process and then +the lack + + align:start position:0% +the lack + + + align:start position:0% +the lack +of uh resources to support everything + + align:start position:0% +of uh resources to support everything + + + align:start position:0% +of uh resources to support everything +you + + align:start position:0% +you + + + align:start position:0% +you +know as as as malus and Endor both said + + align:start position:0% +know as as as malus and Endor both said + + + align:start position:0% +know as as as malus and Endor both said +you know if everything were supported + + align:start position:0% +you know if everything were supported + + + align:start position:0% +you know if everything were supported +one single species would totally occupy + + align:start position:0% +one single species would totally occupy + + + align:start position:0% +one single species would totally occupy +the earth so there's not enough but + + align:start position:0% +the earth so there's not enough but + + + align:start position:0% +the earth so there's not enough but +there's there's something happening here + + align:start position:0% +there's there's something happening here + + + align:start position:0% +there's there's something happening here +right at the heart of this iterative + + align:start position:0% +right at the heart of this iterative + + + align:start position:0% +right at the heart of this iterative +process there is some kind of variation + + align:start position:0% +process there is some kind of variation + + + align:start position:0% +process there is some kind of variation +process that takes + + align:start position:0% +process that takes + + + align:start position:0% +process that takes +place and there's a selecting + + align:start position:0% +place and there's a selecting + + + align:start position:0% +place and there's a selecting +force and with that really really + + align:start position:0% +force and with that really really + + + align:start position:0% +force and with that really really +simple + + align:start position:0% +simple + + + align:start position:0% +simple +Dynamic over large periods of time you + + align:start position:0% +Dynamic over large periods of time you + + + align:start position:0% +Dynamic over large periods of time you +get dramatic + + align:start position:0% +get dramatic + + + align:start position:0% +get dramatic +changes but it's always uh not a known + + align:start position:0% +changes but it's always uh not a known + + + align:start position:0% +changes but it's always uh not a known +facet + + align:start position:0% +facet + + + align:start position:0% +facet +salum nature does not uh go through + + align:start position:0% +salum nature does not uh go through + + + align:start position:0% +salum nature does not uh go through +jumps or does not jump through its its + + align:start position:0% +jumps or does not jump through its its + + + align:start position:0% +jumps or does not jump through its its +development so so this is uh this this + + align:start position:0% +development so so this is uh this this + + + align:start position:0% +development so so this is uh this this +notion of Consciousness is a product of + + align:start position:0% +notion of Consciousness is a product of + + + align:start position:0% +notion of Consciousness is a product of +that I mean that's that's what he's he's + + align:start position:0% +that I mean that's that's what he's he's + + + align:start position:0% +that I mean that's that's what he's he's +pointing out this this notion of + + align:start position:0% +pointing out this this notion of + + + align:start position:0% +pointing out this this notion of +Consciousness is a product of that long + + align:start position:0% +Consciousness is a product of that long + + + align:start position:0% +Consciousness is a product of that long +iteration + + align:start position:0% +iteration + + + align:start position:0% +iteration +um so + + align:start position:0% +um so + + + align:start position:0% +um so +then our our uh our philosopher here + + align:start position:0% +then our our uh our philosopher here + + + align:start position:0% +then our our uh our philosopher here +says + + align:start position:0% +says + + + align:start position:0% +says +um if this can happen with materials + + align:start position:0% +um if this can happen with materials + + + align:start position:0% +um if this can happen with materials +that we would basic basic Bally consider + + align:start position:0% + + + + align:start position:0% + +non-living why why could it not happen + + align:start position:0% +non-living why why could it not happen + + + align:start position:0% +non-living why why could it not happen +with machines so what about this analogy + + align:start position:0% +with machines so what about this analogy + + + align:start position:0% +with machines so what about this analogy +with machines are we back into the the + + align:start position:0% +with machines are we back into the the + + + align:start position:0% +with machines are we back into the the +realm of U cleanthes with uh you know + + align:start position:0% +realm of U cleanthes with uh you know + + + align:start position:0% +realm of U cleanthes with uh you know +analogies that really don't + + align:start position:0% +analogies that really don't + + + align:start position:0% +analogies that really don't +work uh I mean + + align:start position:0% +work uh I mean + + + align:start position:0% +work uh I mean +is why does he apply this concept of + + align:start position:0% +is why does he apply this concept of + + + align:start position:0% +is why does he apply this concept of +machines what is it about + + align:start position:0% +machines what is it about + + + align:start position:0% +machines what is it about +machines uh as opposed to rocks or + + align:start position:0% +machines uh as opposed to rocks or + + + align:start position:0% +machines uh as opposed to rocks or +something + + align:start position:0% + + + + align:start position:0% + +like in terms of national selection + + align:start position:0% +like in terms of national selection + + + align:start position:0% +like in terms of national selection +machines are very very good at what they + + align:start position:0% +machines are very very good at what they + + + align:start position:0% +machines are very very good at what they +do so they're all like they they can all + + align:start position:0% +do so they're all like they they can all + + + align:start position:0% +do so they're all like they they can all +they can almost evolve by by by through + + align:start position:0% +they can almost evolve by by by through + + + align:start position:0% +they can almost evolve by by by through +through us and then they be start + + align:start position:0% +through us and then they be start + + + align:start position:0% +through us and then they be start +becoming the best of what they do to the + + align:start position:0% +becoming the best of what they do to the + + + align:start position:0% +becoming the best of what they do to the +point where they're even better than + + align:start position:0% +point where they're even better than + + + align:start position:0% +point where they're even better than +humans so I guess if you take it from + + align:start position:0% +humans so I guess if you take it from + + + align:start position:0% +humans so I guess if you take it from +that stance you could say that they + + align:start position:0% +that stance you could say that they + + + align:start position:0% +that stance you could say that they +could continue evolving what they better + + align:start position:0% +could continue evolving what they better + + + align:start position:0% +could continue evolving what they better +than hum by + + align:start position:0% +than hum by + + + align:start position:0% +than hum by +themselves + + align:start position:0% +themselves + + + align:start position:0% +themselves +yeah machines uh don't stay the same + + align:start position:0% +yeah machines uh don't stay the same + + + align:start position:0% +yeah machines uh don't stay the same +because we interact with them is that + + align:start position:0% +because we interact with them is that + + + align:start position:0% +because we interact with them is that +correct I mean that's that's how we put + + align:start position:0% +correct I mean that's that's how we put + + + align:start position:0% +correct I mean that's that's how we put +it so we are in some sense a selecting + + align:start position:0% +it so we are in some sense a selecting + + + align:start position:0% +it so we are in some sense a selecting +Force now in what way is this different + + align:start position:0% +Force now in what way is this different + + + align:start position:0% +Force now in what way is this different +from natural + + align:start position:0% +from natural + + + align:start position:0% +from natural +selection the human selecting force on + + align:start position:0% +selection the human selecting force on + + + align:start position:0% +selection the human selecting force on +machines making machines better that + + align:start position:0% +machines making machines better that + + + align:start position:0% +machines making machines better that +primitive uh steam machine of watt as we + + align:start position:0% +primitive uh steam machine of watt as we + + + align:start position:0% +primitive uh steam machine of watt as we +all know + + align:start position:0% +all know + + + align:start position:0% +all know +developed into this these incredible + + align:start position:0% +developed into this these incredible + + + align:start position:0% +developed into this these incredible +Railway + + align:start position:0% +Railway + + + align:start position:0% +Railway +engines so + + align:start position:0% +engines so + + + align:start position:0% +engines so +what how is that similar and different + + align:start position:0% +what how is that similar and different + + + align:start position:0% +what how is that similar and different +from natural + + align:start position:0% +from natural + + + align:start position:0% +from natural +selection well in the case of machines + + align:start position:0% +selection well in the case of machines + + + align:start position:0% +selection well in the case of machines +the humans are constantly adapting the + + align:start position:0% +the humans are constantly adapting the + + + align:start position:0% +the humans are constantly adapting the +machines um and I think Darwin said + + align:start position:0% +machines um and I think Darwin said + + + align:start position:0% +machines um and I think Darwin said +something about like how natural + + align:start position:0% +something about like how natural + + + align:start position:0% +something about like how natural +selection never occurs for one animal + + align:start position:0% +selection never occurs for one animal + + + align:start position:0% +selection never occurs for one animal +like one animal doesn't evolve + + align:start position:0% +like one animal doesn't evolve + + + align:start position:0% +like one animal doesn't evolve +to benefit another animal like it always + + align:start position:0% +to benefit another animal like it always + + + align:start position:0% +to benefit another animal like it always +evolves to benefit itself it always + + align:start position:0% +evolves to benefit itself it always + + + align:start position:0% +evolves to benefit itself it always +selects for things for itself yes I know + + align:start position:0% +selects for things for itself yes I know + + + align:start position:0% +selects for things for itself yes I know +that was in the Instinct chapter but I + + align:start position:0% +that was in the Instinct chapter but I + + + align:start position:0% +that was in the Instinct chapter but I +think it you're you're you're you're + + align:start position:0% +think it you're you're you're you're + + + align:start position:0% +think it you're you're you're you're +absolutely correct the whole he says if + + align:start position:0% +absolutely correct the whole he says if + + + align:start position:0% +absolutely correct the whole he says if +you can tell you can show me something + + align:start position:0% +you can tell you can show me something + + + align:start position:0% +you can tell you can show me something +that doesn't my whole Theory would have + + align:start position:0% +that doesn't my whole Theory would have + + + align:start position:0% +that doesn't my whole Theory would have +to be + + align:start position:0% +to be + + + align:start position:0% +to be +reconsidered so so the machines would + + align:start position:0% +reconsidered so so the machines would + + + align:start position:0% +reconsidered so so the machines would +have to reach some threshold where they + + align:start position:0% +have to reach some threshold where they + + + align:start position:0% +have to reach some threshold where they +could somehow Supply the change + + align:start position:0% +could somehow Supply the change + + + align:start position:0% +could somehow Supply the change +themselves okay okay other thoughts on + + align:start position:0% + + + + align:start position:0% + +this well + + align:start position:0% +this well + + + align:start position:0% +this well +uh is there an instance In Darwin's work + + align:start position:0% +uh is there an instance In Darwin's work + + + align:start position:0% +uh is there an instance In Darwin's work +in in the origin where we do have + + align:start position:0% +in in the origin where we do have + + + align:start position:0% +in in the origin where we do have +organisms that are changing for other + + align:start position:0% + + + + align:start position:0% + +organisms how about the first + + align:start position:0% + + + + align:start position:0% + +chapter domestication + + align:start position:0% +chapter domestication + + + align:start position:0% +chapter domestication +I mean those those organisms are + + align:start position:0% +I mean those those organisms are + + + align:start position:0% +I mean those those organisms are +changing for the benefit of other + + align:start position:0% +changing for the benefit of other + + + align:start position:0% +changing for the benefit of other +organisms + + align:start position:0% +organisms + + + align:start position:0% +organisms +I.E + + align:start position:0% +I.E + + + align:start position:0% +I.E +as yeah but we're select you know the + + align:start position:0% +as yeah but we're select you know the + + + align:start position:0% +as yeah but we're select you know the +the humans whether it's conscious + + align:start position:0% +the humans whether it's conscious + + + align:start position:0% +the humans whether it's conscious +selection or unconscious selection are + + align:start position:0% +selection or unconscious selection are + + + align:start position:0% +selection or unconscious selection are +selecting + + align:start position:0% +selecting + + + align:start position:0% +selecting +uh the + + align:start position:0% +uh the + + + align:start position:0% +uh the +individuals whether it's sheep or + + align:start position:0% +individuals whether it's sheep or + + + align:start position:0% +individuals whether it's sheep or +chickens or whatever they're breeding + + align:start position:0% +chickens or whatever they're breeding + + + align:start position:0% +chickens or whatever they're breeding +them into domestic species for their own + + align:start position:0% +them into domestic species for their own + + + align:start position:0% +them into domestic species for their own +purposes yes the difference between that + + align:start position:0% +purposes yes the difference between that + + + align:start position:0% +purposes yes the difference between that +and machines is that um machines aren't + + align:start position:0% +and machines is that um machines aren't + + + align:start position:0% +and machines is that um machines aren't +their own source of mutation okay the + + align:start position:0% +their own source of mutation okay the + + + align:start position:0% +their own source of mutation okay the +humans are what the selector and the + + align:start position:0% +humans are what the selector and the + + + align:start position:0% +humans are what the selector and the +source of mutation is in selection of + + align:start position:0% +source of mutation is in selection of + + + align:start position:0% +source of mutation is in selection of +animals they create Rand mutations than + + align:start position:0% +animals they create Rand mutations than + + + align:start position:0% +animals they create Rand mutations than +yeah yeah they're working with naturally + + align:start position:0% +yeah yeah they're working with naturally + + + align:start position:0% +yeah yeah they're working with naturally +yeah provid good point + + align:start position:0% +yeah provid good point + + + align:start position:0% +yeah provid good point +absolutely so maybe maybe we have + + align:start position:0% +absolutely so maybe maybe we have + + + align:start position:0% +absolutely so maybe maybe we have +to revise our theories somewhat does + + align:start position:0% +to revise our theories somewhat does + + + align:start position:0% +to revise our theories somewhat does +this and the question is does this is + + align:start position:0% +this and the question is does this is + + + align:start position:0% +this and the question is does this is +this enough to + + align:start position:0% +this enough to + + + align:start position:0% +this enough to +say uh these ideas don't work for + + align:start position:0% +say uh these ideas don't work for + + + align:start position:0% +say uh these ideas don't work for +machines Elisha you were going to + + align:start position:0% +machines Elisha you were going to + + + align:start position:0% +machines Elisha you were going to +say yeah + + align:start position:0% +say yeah + + + align:start position:0% +say yeah +okay about the difference between + + align:start position:0% +okay about the difference between + + + align:start position:0% +okay about the difference between +conscious and unconscious selection + + align:start position:0% +conscious and unconscious selection + + + align:start position:0% +conscious and unconscious selection +okay all right so yeah conscious and + + align:start position:0% +okay all right so yeah conscious and + + + align:start position:0% +okay all right so yeah conscious and +unconscious selection are in the + + align:start position:0% +unconscious selection are in the + + + align:start position:0% +unconscious selection are in the +background here and certainly um + + align:start position:0% +background here and certainly um + + + align:start position:0% +background here and certainly um +probably a lot of machine but but the + + align:start position:0% +probably a lot of machine but but the + + + align:start position:0% +probably a lot of machine but but the +fact is is humans are selecting + + align:start position:0% +fact is is humans are selecting + + + align:start position:0% +fact is is humans are selecting +machines + + align:start position:0% +machines + + + align:start position:0% +machines +and I I don't know maybe selecting is + + align:start position:0% +and I I don't know maybe selecting is + + + align:start position:0% +and I I don't know maybe selecting is +not all I mean selecting is not all are + + align:start position:0% +not all I mean selecting is not all are + + + align:start position:0% +not all I mean selecting is not all are +doing humans are building them too + + align:start position:0% +doing humans are building them too + + + align:start position:0% +doing humans are building them too +yeah the humans are coding the machine + + align:start position:0% +yeah the humans are coding the machine + + + align:start position:0% +yeah the humans are coding the machine +so so whereas you know DNA can vary on + + align:start position:0% +so so whereas you know DNA can vary on + + + align:start position:0% +so so whereas you know DNA can vary on +its own you know if if there's a + + align:start position:0% +its own you know if if there's a + + + align:start position:0% +its own you know if if there's a +variance in uh in like computer code + + align:start position:0% +variance in uh in like computer code + + + align:start position:0% +variance in uh in like computer code +then it's something that we've done and + + align:start position:0% +then it's something that we've done and + + + align:start position:0% +then it's something that we've done and +we can probably fix but we're not + + align:start position:0% +we can probably fix but we're not + + + align:start position:0% +we can probably fix but we're not +necessarily perfect in our programming + + align:start position:0% +necessarily perfect in our programming + + + align:start position:0% +necessarily perfect in our programming +ways what if we made an unconscious + + align:start position:0% + + + + align:start position:0% + +mistake you remember the Terminator uh + + align:start position:0% +mistake you remember the Terminator uh + + + align:start position:0% +mistake you remember the Terminator uh +film where I say uh what is it oh you + + align:start position:0% +film where I say uh what is it oh you + + + align:start position:0% +film where I say uh what is it oh you +haven't seen it yeah so there's this + + align:start position:0% +haven't seen it yeah so there's this + + + align:start position:0% +haven't seen it yeah so there's this +moment where there there's this this + + align:start position:0% +moment where there there's this this + + + align:start position:0% +moment where there there's this this +this this this sort of network of + + align:start position:0% +this this this sort of network of + + + align:start position:0% +this this this sort of network of +computers sky sky Skynet + + align:start position:0% +computers sky sky Skynet + + + align:start position:0% +computers sky sky Skynet +has achieved Consciousness at 10 + + align:start position:0% +has achieved Consciousness at 10 + + + align:start position:0% +has achieved Consciousness at 10 +something or they say and boom suddenly + + align:start position:0% +something or they say and boom suddenly + + + align:start position:0% +something or they say and boom suddenly +you know all this network computing is + + align:start position:0% +you know all this network computing is + + + align:start position:0% +you know all this network computing is +thinking for itself and you know it's + + align:start position:0% +thinking for itself and you know it's + + + align:start position:0% +thinking for itself and you know it's +like + + align:start position:0% +like + + + align:start position:0% +like +wow I mean that's that's science fiction + + align:start position:0% +wow I mean that's that's science fiction + + + align:start position:0% +wow I mean that's that's science fiction +but uh but it brings up uh one important + + align:start position:0% +but uh but it brings up uh one important + + + align:start position:0% +but uh but it brings up uh one important +thing and that is uh Butler's concept of + + align:start position:0% +thing and that is uh Butler's concept of + + + align:start position:0% +thing and that is uh Butler's concept of +machine and our more contemporary + + align:start position:0% +machine and our more contemporary + + + align:start position:0% +machine and our more contemporary +concept of machine how do they differ + + align:start position:0% +concept of machine how do they differ + + + align:start position:0% +concept of machine how do they differ +how are they similar + + align:start position:0% + + + + align:start position:0% + +I think Butler's concept of + + align:start position:0% +I think Butler's concept of + + + align:start position:0% +I think Butler's concept of +machine I don't think it's like + + align:start position:0% +machine I don't think it's like + + + align:start position:0% +machine I don't think it's like +impossible like in the future like given + + align:start position:0% +impossible like in the future like given + + + align:start position:0% +impossible like in the future like given +the way we've advanced + + align:start position:0% +the way we've advanced + + + align:start position:0% +the way we've advanced +technology I mean I don't think it's + + align:start position:0% +technology I mean I don't think it's + + + align:start position:0% +technology I mean I don't think it's +impossible to one day imagine machines + + align:start position:0% +impossible to one day imagine machines + + + align:start position:0% +impossible to one day imagine machines +at that level at you know like Butler's + + align:start position:0% +at that level at you know like Butler's + + + align:start position:0% +at that level at you know like Butler's +level at the science fiction level yeah + + align:start position:0% +level at the science fiction level yeah + + + align:start position:0% +level at the science fiction level yeah +yeah I mean he certainly is is uh aware + + align:start position:0% +yeah I mean he certainly is is uh aware + + + align:start position:0% +yeah I mean he certainly is is uh aware +of uh you know machines being capable of + + align:start position:0% +of uh you know machines being capable of + + + align:start position:0% +of uh you know machines being capable of +calculating + + align:start position:0% +calculating + + + align:start position:0% +calculating +things and thinking as he says as as as + + align:start position:0% +things and thinking as he says as as as + + + align:start position:0% +things and thinking as he says as as as +the writer in the book says the man + + align:start position:0% +the writer in the book says the man + + + align:start position:0% +the writer in the book says the man +professor says you know when we need to + + align:start position:0% +professor says you know when we need to + + + align:start position:0% +professor says you know when we need to +do numbers we fly to our machines + + align:start position:0% +do numbers we fly to our machines + + + align:start position:0% +do numbers we fly to our machines +they're faster they don't need to rest + + align:start position:0% +they're faster they don't need to rest + + + align:start position:0% +they're faster they don't need to rest +and they're more accurate than we + + align:start position:0% +and they're more accurate than we + + + align:start position:0% +and they're more accurate than we +are uh of course we build them and we + + align:start position:0% +are uh of course we build them and we + + + align:start position:0% +are uh of course we build them and we +keep them going and so forth but + + align:start position:0% +keep them going and so forth but + + + align:start position:0% +keep them going and so forth but +nevertheless they function better at + + align:start position:0% +nevertheless they function better at + + + align:start position:0% +nevertheless they function better at +certain levels + + align:start position:0% +certain levels + + + align:start position:0% +certain levels +so uh he's aware of this but most of his + + align:start position:0% +so uh he's aware of this but most of his + + + align:start position:0% +so uh he's aware of this but most of his +mechanical examples here are 19th + + align:start position:0% +mechanical examples here are 19th + + + align:start position:0% +mechanical examples here are 19th +century + + align:start position:0% +century + + + align:start position:0% +century +mechanical the computational + + align:start position:0% +mechanical the computational + + + align:start position:0% +mechanical the computational +world that we see coming in just in its + + align:start position:0% +world that we see coming in just in its + + + align:start position:0% +world that we see coming in just in its +early nent stage with + + align:start position:0% +early nent stage with + + + align:start position:0% +early nent stage with +babage is going to + + align:start position:0% +babage is going to + + + align:start position:0% +babage is going to +explode later but that's going to be + + align:start position:0% +explode later but that's going to be + + + align:start position:0% +explode later but that's going to be +after Butler's time but the concept of a + + align:start position:0% +after Butler's time but the concept of a + + + align:start position:0% +after Butler's time but the concept of a +machine as a device + + align:start position:0% +machine as a device + + + align:start position:0% +machine as a device +for achieving a certain end will become + + align:start position:0% +for achieving a certain end will become + + + align:start position:0% +for achieving a certain end will become +more + + align:start position:0% +more + + + align:start position:0% +more +complicated the early versions of + + align:start position:0% +complicated the early versions of + + + align:start position:0% +complicated the early versions of +machine the steam machines and things of + + align:start position:0% +machine the steam machines and things of + + + align:start position:0% +machine the steam machines and things of +that sort are you know powerful very + + align:start position:0% +that sort are you know powerful very + + + align:start position:0% +that sort are you know powerful very +very effective at what they do and + + align:start position:0% +very effective at what they do and + + + align:start position:0% +very effective at what they do and +prevalent but in that + + align:start position:0% +prevalent but in that + + + align:start position:0% +prevalent but in that +very evolution of things machines are + + align:start position:0% +very evolution of things machines are + + + align:start position:0% +very evolution of things machines are +going to be become vastly more + + align:start position:0% +going to be become vastly more + + + align:start position:0% +going to be become vastly more +complicated vastly more + + align:start position:0% +complicated vastly more + + + align:start position:0% +complicated vastly more +capable this is more what we would + + align:start position:0% +capable this is more what we would + + + align:start position:0% +capable this is more what we would +associate with a lamaran model of the + + align:start position:0% +associate with a lamaran model of the + + + align:start position:0% +associate with a lamaran model of the +the + + align:start position:0% +the + + + align:start position:0% +the +transmission of + + align:start position:0% +transmission of + + + align:start position:0% +transmission of +innovative features so this whole + + align:start position:0% +innovative features so this whole + + + align:start position:0% +innovative features so this whole +concept that uh uh inheritance actually + + align:start position:0% +concept that uh uh inheritance actually + + + align:start position:0% +concept that uh uh inheritance actually +works and + + align:start position:0% +works and + + + align:start position:0% +works and +transmits + + align:start position:0% +transmits + + + align:start position:0% +transmits +the uh the new + + align:start position:0% +the uh the new + + + align:start position:0% +the uh the new +level of adap adaptation of the parent + + align:start position:0% +level of adap adaptation of the parent + + + align:start position:0% +level of adap adaptation of the parent +that has been achieved by the parent + + align:start position:0% +that has been achieved by the parent + + + align:start position:0% +that has been achieved by the parent +that kind of model for uh that's a + + align:start position:0% +that kind of model for uh that's a + + + align:start position:0% +that kind of model for uh that's a +that's a model for very rapid change + + align:start position:0% +that's a model for very rapid change + + + align:start position:0% +that's a model for very rapid change +it's still + + align:start position:0% +it's still + + + align:start position:0% +it's still +systematic these these changes all seem + + align:start position:0% +systematic these these changes all seem + + + align:start position:0% +systematic these these changes all seem +to + + align:start position:0% +to + + + align:start position:0% +to +uh I mean they're made because they + + align:start position:0% +uh I mean they're made because they + + + align:start position:0% +uh I mean they're made because they +Advance functionality and adaptability + + align:start position:0% +Advance functionality and adaptability + + + align:start position:0% +Advance functionality and adaptability +if you will to the + + align:start position:0% +if you will to the + + + align:start position:0% +if you will to the +task so but there there's some kind of + + align:start position:0% +task so but there there's some kind of + + + align:start position:0% +task so but there there's some kind of +mechanism here and you know this this + + align:start position:0% +mechanism here and you know this this + + + align:start position:0% +mechanism here and you know this this +this + + align:start position:0% +this + + + align:start position:0% +this +um you know the the argument in in the + + align:start position:0% +um you know the the argument in in the + + + align:start position:0% +um you know the the argument in in the +book uh of machines here is yeah okay so + + align:start position:0% +book uh of machines here is yeah okay so + + + align:start position:0% +book uh of machines here is yeah okay so +machines evolve through the + + align:start position:0% +machines evolve through the + + + align:start position:0% +machines evolve through the +intermediary of + + align:start position:0% +intermediary of + + + align:start position:0% +intermediary of +humans but so + + align:start position:0% +humans but so + + + align:start position:0% +humans but so +what they still + + align:start position:0% +what they still + + + align:start position:0% +what they still +evolve and so yeah it's a different + + align:start position:0% +evolve and so yeah it's a different + + + align:start position:0% +evolve and so yeah it's a different +form but we would want to think of it at + + align:start position:0% +form but we would want to think of it at + + + align:start position:0% +form but we would want to think of it at +least in these terms because in many + + align:start position:0% +least in these terms because in many + + + align:start position:0% +least in these terms because in many +ways they're doing the same things as or + + align:start position:0% +ways they're doing the same things as or + + + align:start position:0% +ways they're doing the same things as or +they're they're performing functions and + + align:start position:0% +they're they're performing functions and + + + align:start position:0% +they're they're performing functions and +in many ways these these functions + + align:start position:0% +in many ways these these functions + + + align:start position:0% +in many ways these these functions +are + + align:start position:0% +are + + + align:start position:0% +are +um + + align:start position:0% +um + + + align:start position:0% +um +advancing + + align:start position:0% +advancing + + + align:start position:0% +advancing +in function in in in + + align:start position:0% +in function in in in + + + align:start position:0% +in function in in in +ability so it's it's Happ it + + align:start position:0% +ability so it's it's Happ it + + + align:start position:0% +ability so it's it's Happ it +and this this notion and of + + align:start position:0% + + + + align:start position:0% + +self-replication uh you know do things + + align:start position:0% +self-replication uh you know do things + + + align:start position:0% +self-replication uh you know do things +have to be uh + + align:start position:0% +have to be uh + + + align:start position:0% +have to be uh +intentional + + align:start position:0% +intentional + + + align:start position:0% +intentional +uh is you know is it necessary for + + align:start position:0% +uh is you know is it necessary for + + + align:start position:0% +uh is you know is it necessary for +self-consciousness to uh be part of + + align:start position:0% +self-consciousness to uh be part of + + + align:start position:0% +self-consciousness to uh be part of +self-replication um and what is the Mad + + align:start position:0% +self-replication um and what is the Mad + + + align:start position:0% +self-replication um and what is the Mad +professor + + align:start position:0% + + + + align:start position:0% + +argue well he says one thing what is + + align:start position:0% +argue well he says one thing what is + + + align:start position:0% +argue well he says one thing what is +consciousness I mean do we have a + + align:start position:0% +consciousness I mean do we have a + + + align:start position:0% +consciousness I mean do we have a +definition of Consciousness I mean we + + align:start position:0% +definition of Consciousness I mean we + + + align:start position:0% +definition of Consciousness I mean we +all think we know what Consciousness is + + align:start position:0% +all think we know what Consciousness is + + + align:start position:0% +all think we know what Consciousness is +but uh you know how do we know I mean + + align:start position:0% +but uh you know how do we know I mean + + + align:start position:0% +but uh you know how do we know I mean +how do I know you all aren't zombies who + + align:start position:0% +how do I know you all aren't zombies who + + + align:start position:0% +how do I know you all aren't zombies who +come here to my class to how do you know + + align:start position:0% +come here to my class to how do you know + + + align:start position:0% +come here to my class to how do you know +I'm not just some kind of programmed you + + align:start position:0% +I'm not just some kind of programmed you + + + align:start position:0% +I'm not just some kind of programmed you +know something that MIT is testing out + + align:start position:0% +know something that MIT is testing out + + + align:start position:0% +know something that MIT is testing out +and they have this guy showing up every + + align:start position:0% +and they have this guy showing up every + + + align:start position:0% +and they have this guy showing up every +every morning and he's he's trying to + + align:start position:0% +every morning and he's he's trying to + + + align:start position:0% +every morning and he's he's trying to +teach this class and you know there's + + align:start position:0% +teach this class and you know there's + + + align:start position:0% +teach this class and you know there's +some person just behind + + align:start position:0% +some person just behind + + + align:start position:0% +some person just behind +the the wall who's manipulating me you + + align:start position:0% +the the wall who's manipulating me you + + + align:start position:0% +the the wall who's manipulating me you +know I mean do you know do you know + + align:start position:0% +know I mean do you know do you know + + + align:start position:0% +know I mean do you know do you know +what's in somebody else's head yeah I + + align:start position:0% +what's in somebody else's head yeah I + + + align:start position:0% +what's in somebody else's head yeah I +think our ideas of Consciousness is like + + align:start position:0% +think our ideas of Consciousness is like + + + align:start position:0% +think our ideas of Consciousness is like +from earlier in the year it's one of + + align:start position:0% +from earlier in the year it's one of + + + align:start position:0% +from earlier in the year it's one of +those things that we only really know + + align:start position:0% +those things that we only really know + + + align:start position:0% +those things that we only really know +through our daily experience with it but + + align:start position:0% +through our daily experience with it but + + + align:start position:0% +through our daily experience with it but +when we get outside of sort of our + + align:start position:0% +when we get outside of sort of our + + + align:start position:0% +when we get outside of sort of our +comfort zone things get fuzzy MH okay so + + align:start position:0% +comfort zone things get fuzzy MH okay so + + + align:start position:0% +comfort zone things get fuzzy MH okay so +we sort of know what we + + align:start position:0% +we sort of know what we + + + align:start position:0% +we sort of know what we +know and you know + + align:start position:0% +know and you know + + + align:start position:0% +know and you know +uh as day cart says I think therefore I + + align:start position:0% +uh as day cart says I think therefore I + + + align:start position:0% +uh as day cart says I think therefore I +am that's a pretty confident + + align:start position:0% +am that's a pretty confident + + + align:start position:0% +am that's a pretty confident +statement but do you think and therefore + + align:start position:0% +statement but do you think and therefore + + + align:start position:0% +statement but do you think and therefore +are you I mean we we we we we can't + + align:start position:0% +are you I mean we we we we we can't + + + align:start position:0% +are you I mean we we we we we can't +absolutely + + align:start position:0% +absolutely + + + align:start position:0% +absolutely +verify you know the so and and even even + + align:start position:0% +verify you know the so and and even even + + + align:start position:0% +verify you know the so and and even even +then even if we can still what is what + + align:start position:0% +then even if we can still what is what + + + align:start position:0% +then even if we can still what is what +it what is the definition of + + align:start position:0% +it what is the definition of + + + align:start position:0% +it what is the definition of +self-consciousness + + align:start position:0% +self-consciousness + + + align:start position:0% +self-consciousness +you know we we we struggle with that + + align:start position:0% +you know we we we struggle with that + + + align:start position:0% +you know we we we struggle with that +especially when we try to I mean we + + align:start position:0% +especially when we try to I mean we + + + align:start position:0% +especially when we try to I mean we +don't struggle with it at the level of + + align:start position:0% +don't struggle with it at the level of + + + align:start position:0% +don't struggle with it at the level of +say the + + align:start position:0% +say the + + + align:start position:0% +say the +novel or I mean certainly some novels + + align:start position:0% +novel or I mean certainly some novels + + + align:start position:0% +novel or I mean certainly some novels +take up the questions of Consciousness + + align:start position:0% +take up the questions of Consciousness + + + align:start position:0% +take up the questions of Consciousness +PR was very into questions like this and + + align:start position:0% +PR was very into questions like this and + + + align:start position:0% +PR was very into questions like this and +but you + + align:start position:0% +but you + + + align:start position:0% +but you +know where where we really begin to + + align:start position:0% +know where where we really begin to + + + align:start position:0% +know where where we really begin to +struggle with self-consciousness when we + + align:start position:0% +struggle with self-consciousness when we + + + align:start position:0% +struggle with self-consciousness when we +begin to try to think of it in a + + align:start position:0% +begin to try to think of it in a + + + align:start position:0% +begin to try to think of it in a +scientific framework work of analyzing + + align:start position:0% +scientific framework work of analyzing + + + align:start position:0% +scientific framework work of analyzing +it and producing it I mean what would it + + align:start position:0% +it and producing it I mean what would it + + + align:start position:0% +it and producing it I mean what would it +mean to produce + + align:start position:0% +mean to produce + + + align:start position:0% +mean to produce +Consciousness well you got you have to + + align:start position:0% +Consciousness well you got you have to + + + align:start position:0% +Consciousness well you got you have to +come up with some definitions + + align:start position:0% +come up with some definitions + + + align:start position:0% +come up with some definitions +definitions aren't all that + + align:start position:0% +definitions aren't all that + + + align:start position:0% +definitions aren't all that +easy yeah David I think like part of us + + align:start position:0% +easy yeah David I think like part of us + + + align:start position:0% +easy yeah David I think like part of us +being unable to deal with you know with + + align:start position:0% +being unable to deal with you know with + + + align:start position:0% +being unable to deal with you know with +the concept of Consciousness with + + align:start position:0% +the concept of Consciousness with + + + align:start position:0% +the concept of Consciousness with +machines is if you look at you know as + + align:start position:0% +machines is if you look at you know as + + + align:start position:0% +machines is if you look at you know as +machines become more and + + align:start position:0% +machines become more and + + + align:start position:0% +machines become more and +more uh I guess used like in the home or + + align:start position:0% +more uh I guess used like in the home or + + + align:start position:0% +more uh I guess used like in the home or +whatever it + + align:start position:0% +whatever it + + + align:start position:0% +whatever it +okay a specific example like imagine you + + align:start position:0% +okay a specific example like imagine you + + + align:start position:0% +okay a specific example like imagine you +know the little robotic vacuums right um + + align:start position:0% +know the little robotic vacuums right um + + + align:start position:0% +know the little robotic vacuums right um +that kind of autonomously go around the + + align:start position:0% +that kind of autonomously go around the + + + align:start position:0% +that kind of autonomously go around the +house like like how many people do you + + align:start position:0% +house like like how many people do you + + + align:start position:0% +house like like how many people do you +know personify those vacuums like they + + align:start position:0% +know personify those vacuums like they + + + align:start position:0% +know personify those vacuums like they +consider like a pet like they you know + + align:start position:0% +consider like a pet like they you know + + + align:start position:0% +consider like a pet like they you know +it's it's easy for us to imagine that + + align:start position:0% +it's it's easy for us to imagine that + + + align:start position:0% +it's it's easy for us to imagine that +that + + align:start position:0% +that + + + align:start position:0% +that +vacuum has a little goal in mind while + + align:start position:0% +vacuum has a little goal in mind while + + + align:start position:0% +vacuum has a little goal in mind while +it's vacuuming just because we're so + + align:start position:0% +it's vacuuming just because we're so + + + align:start position:0% +it's vacuuming just because we're so +used to a Consciousness that it's hard + + align:start position:0% +used to a Consciousness that it's hard + + + align:start position:0% +used to a Consciousness that it's hard +for us to see a + + align:start position:0% +for us to see a + + + align:start position:0% +for us to see a +machine acting like a us or performing a + + align:start position:0% +machine acting like a us or performing a + + + align:start position:0% +machine acting like a us or performing a +task like us and not expected to have + + align:start position:0% +task like us and not expected to have + + + align:start position:0% +task like us and not expected to have +any type of right internal this is this + + align:start position:0% +any type of right internal this is this + + + align:start position:0% +any type of right internal this is this +is a big absolute I mean Turing would + + align:start position:0% +is a big absolute I mean Turing would + + + align:start position:0% +is a big absolute I mean Turing would +come up with the Turing test we're going + + align:start position:0% +come up with the Turing test we're going + + + align:start position:0% +come up with the Turing test we're going +to read Turing a little later but you + + align:start position:0% +to read Turing a little later but you + + + align:start position:0% +to read Turing a little later but you +know Alan Turing thought about these + + align:start position:0% +know Alan Turing thought about these + + + align:start position:0% +know Alan Turing thought about these +problems he tried to understand them and + + align:start position:0% +problems he tried to understand them and + + + align:start position:0% +problems he tried to understand them and +tried to come up with ways of thinking + + align:start position:0% +tried to come up with ways of thinking + + + align:start position:0% +tried to come up with ways of thinking +about them not always successful but + + align:start position:0% +about them not always successful but + + + align:start position:0% +about them not always successful but +pretty pretty + + align:start position:0% +pretty pretty + + + align:start position:0% +pretty pretty +penetrating + + align:start position:0% +penetrating + + + align:start position:0% +penetrating +um but uh certainly + + align:start position:0% +um but uh certainly + + + align:start position:0% +um but uh certainly +a lot of the things you know do you + + align:start position:0% +a lot of the things you know do you + + + align:start position:0% +a lot of the things you know do you +think we're all our all we are + + align:start position:0% +think we're all our all we are + + + align:start position:0% +think we're all our all we are +constantly self-conscious of everything + + align:start position:0% +constantly self-conscious of everything + + + align:start position:0% +constantly self-conscious of everything +that we do I mean we do a tremendous + + align:start position:0% +that we do I mean we do a tremendous + + + align:start position:0% +that we do I mean we do a tremendous +amount of work + + align:start position:0% +amount of work + + + align:start position:0% +amount of work +labor which we don't think consciously + + align:start position:0% +labor which we don't think consciously + + + align:start position:0% +labor which we don't think consciously +about it as we do it I mean so this + + align:start position:0% +about it as we do it I mean so this + + + align:start position:0% +about it as we do it I mean so this +whole notion of Consciousness is you + + align:start position:0% +whole notion of Consciousness is you + + + align:start position:0% +whole notion of Consciousness is you +know it's it's not always present in + + align:start position:0% +know it's it's not always present in + + + align:start position:0% +know it's it's not always present in +behavior and so you know it it sort of + + align:start position:0% +behavior and so you know it it sort of + + + align:start position:0% +behavior and so you know it it sort of +Glides it's it's it's uh and + + align:start position:0% +Glides it's it's it's uh and + + + align:start position:0% +Glides it's it's it's uh and +and the Book of the machines argues + + align:start position:0% +and the Book of the machines argues + + + align:start position:0% +and the Book of the machines argues +something to the effect that how can we + + align:start position:0% +something to the effect that how can we + + + align:start position:0% +something to the effect that how can we +know a potato doesn't have I mean a + + align:start position:0% +know a potato doesn't have I mean a + + + align:start position:0% +know a potato doesn't have I mean a +potato in a in a Cellar grows roots and + + align:start position:0% +potato in a in a Cellar grows roots and + + + align:start position:0% +potato in a in a Cellar grows roots and +tries + + align:start position:0% +tries + + + align:start position:0% +tries +to we say try uh these roots go toward + + align:start position:0% +to we say try uh these roots go toward + + + align:start position:0% +to we say try uh these roots go toward +uh they phototropic or whatever they are + + align:start position:0% +uh they phototropic or whatever they are + + + align:start position:0% +uh they phototropic or whatever they are +and they look for opportunities to uh + + align:start position:0% +and they look for opportunities to uh + + + align:start position:0% +and they look for opportunities to uh +implant themselves into some source of + + align:start position:0% +implant themselves into some source of + + + align:start position:0% +implant themselves into some source of +sustenance and uh as the professor says + + align:start position:0% +sustenance and uh as the professor says + + + align:start position:0% +sustenance and uh as the professor says +in the book he says isn't this a sort of + + align:start position:0% +in the book he says isn't this a sort of + + + align:start position:0% +in the book he says isn't this a sort of +low form of + + align:start position:0% +low form of + + + align:start position:0% +low form of +Consciousness I mean at what level does + + align:start position:0% +Consciousness I mean at what level does + + + align:start position:0% +Consciousness I mean at what level does +Consciousness start in the animal + + align:start position:0% +Consciousness start in the animal + + + align:start position:0% +Consciousness start in the animal +world or insex + + align:start position:0% + + + + align:start position:0% + +conscious what do you think + + align:start position:0% +conscious what do you think + + + align:start position:0% +conscious what do you think +Charles + + align:start position:0% +Charles + + + align:start position:0% +Charles +um I think coming up from the very + + align:start position:0% +um I think coming up from the very + + + align:start position:0% +um I think coming up from the very +bottom of nature where like there's + + align:start position:0% +bottom of nature where like there's + + + align:start position:0% +bottom of nature where like there's +always the question of the line between + + align:start position:0% +always the question of the line between + + + align:start position:0% +always the question of the line between +being conscious and not conscious and as + + align:start position:0% +being conscious and not conscious and as + + + align:start position:0% +being conscious and not conscious and as +we so very obviously like individual + + align:start position:0% +we so very obviously like individual + + + align:start position:0% +we so very obviously like individual +cells are not conscious because like + + align:start position:0% +cells are not conscious because like + + + align:start position:0% +cells are not conscious because like +it's just one cell and there's no + + align:start position:0% +it's just one cell and there's no + + + align:start position:0% +it's just one cell and there's no +different components that can allow for + + align:start position:0% +different components that can allow for + + + align:start position:0% +different components that can allow for +a cell to be like functioning but also + + align:start position:0% +a cell to be like functioning but also + + + align:start position:0% +a cell to be like functioning but also +other parts that can allow it to think + + align:start position:0% +other parts that can allow it to think + + + align:start position:0% +other parts that can allow it to think +but like obviously there's like I think + + align:start position:0% +but like obviously there's like I think + + + align:start position:0% +but like obviously there's like I think +Consciousness is just a man + + align:start position:0% +Consciousness is just a man + + + align:start position:0% +Consciousness is just a man +manifestation of natural + + align:start position:0% +manifestation of natural + + + align:start position:0% +manifestation of natural +response um that all organ organisms + + align:start position:0% +response um that all organ organisms + + + align:start position:0% +response um that all organ organisms +have to outside stimuli like if you + + align:start position:0% +have to outside stimuli like if you + + + align:start position:0% +have to outside stimuli like if you +stimulate a cell if you make like one + + align:start position:0% +stimulate a cell if you make like one + + + align:start position:0% +stimulate a cell if you make like one +region hot like things are going to like + + align:start position:0% +region hot like things are going to like + + + align:start position:0% +region hot like things are going to like +creatures small creatures are going to + + align:start position:0% +creatures small creatures are going to + + + align:start position:0% +creatures small creatures are going to +move away from it so you're saying + + align:start position:0% +move away from it so you're saying + + + align:start position:0% +move away from it so you're saying +protozone has a kind of a + + align:start position:0% +protozone has a kind of a + + + align:start position:0% +protozone has a kind of a +Consciousness it + + align:start position:0% +Consciousness it + + + align:start position:0% +Consciousness it +has has an + + align:start position:0% +has has an + + + align:start position:0% +has has an +instinct without actually being an + + align:start position:0% +instinct without actually being an + + + align:start position:0% +instinct without actually being an +instinct it has a tendency to want to + + align:start position:0% +instinct it has a tendency to want to + + + align:start position:0% +instinct it has a tendency to want to +survive and I think it Consciousness is + + align:start position:0% +survive and I think it Consciousness is + + + align:start position:0% +survive and I think it Consciousness is +just a manifestation of that and the + + align:start position:0% +just a manifestation of that and the + + + align:start position:0% +just a manifestation of that and the +line where like what we feel is + + align:start position:0% +line where like what we feel is + + + align:start position:0% +line where like what we feel is +consciousness is hard to + + align:start position:0% +consciousness is hard to + + + align:start position:0% +consciousness is hard to +nail well let me just read this quick + + align:start position:0% +nail well let me just read this quick + + + align:start position:0% +nail well let me just read this quick +but who can say that the vapor engine + + align:start position:0% +but who can say that the vapor engine + + + align:start position:0% +but who can say that the vapor engine +has not a kind of Consciousness where + + align:start position:0% +has not a kind of Consciousness where + + + align:start position:0% +has not a kind of Consciousness where +does Consciousness begin and where end + + align:start position:0% +does Consciousness begin and where end + + + align:start position:0% +does Consciousness begin and where end +who can draw the line who can draw any l + + align:start position:0% +who can draw the line who can draw any l + + + align:start position:0% +who can draw the line who can draw any l +line is not everything interwoven with + + align:start position:0% +line is not everything interwoven with + + + align:start position:0% +line is not everything interwoven with +everything well he's getting is not + + align:start position:0% +everything well he's getting is not + + + align:start position:0% +everything well he's getting is not +Machinery linked with animal life in an + + align:start position:0% +Machinery linked with animal life in an + + + align:start position:0% +Machinery linked with animal life in an +infinite variety of + + align:start position:0% +infinite variety of + + + align:start position:0% +infinite variety of +ways so David you had your hand on like + + align:start position:0% +ways so David you had your hand on like + + + align:start position:0% +ways so David you had your hand on like +there's a few lines there like instinct + + align:start position:0% +there's a few lines there like instinct + + + align:start position:0% +there's a few lines there like instinct +there's Consciousness and there's like + + align:start position:0% +there's Consciousness and there's like + + + align:start position:0% +there's Consciousness and there's like +self-awareness because I think we can + + align:start position:0% +self-awareness because I think we can + + + align:start position:0% +self-awareness because I think we can +okay I think we can agree that like most + + align:start position:0% +okay I think we can agree that like most + + + align:start position:0% +okay I think we can agree that like most +complex animals are conscious you know + + align:start position:0% +complex animals are conscious you know + + + align:start position:0% +complex animals are conscious you know +but you know like my cat is conscious + + align:start position:0% +but you know like my cat is conscious + + + align:start position:0% +but you know like my cat is conscious +but does my cat is my cat self-aware + + align:start position:0% +but does my cat is my cat self-aware + + + align:start position:0% +but does my cat is my cat self-aware +does it like consider its own existence + + align:start position:0% +does it like consider its own existence + + + align:start position:0% +does it like consider its own existence +you know I think that's a big line too + + align:start position:0% +you know I think that's a big line too + + + align:start position:0% +you know I think that's a big line too +so yeah people are studying the these + + align:start position:0% +so yeah people are studying the these + + + align:start position:0% +so yeah people are studying the these +questions even as we sit here um he says + + align:start position:0% +questions even as we sit here um he says + + + align:start position:0% +questions even as we sit here um he says +further on + + align:start position:0% +further on + + + align:start position:0% +further on +um uh you know he says uh whether those + + align:start position:0% +um uh you know he says uh whether those + + + align:start position:0% +um uh you know he says uh whether those +things which we deem most purely + + align:start position:0% +things which we deem most purely + + + align:start position:0% +things which we deem most purely +spiritual are anything but disturbances + + align:start position:0% +spiritual are anything but disturbances + + + align:start position:0% +spiritual are anything but disturbances +of equilibrium in an infinite series of + + align:start position:0% +of equilibrium in an infinite series of + + + align:start position:0% +of equilibrium in an infinite series of +levers so we're coming back to you + + align:start position:0% +levers so we're coming back to you + + + align:start position:0% +levers so we're coming back to you +remember py how beautifully he outlined + + align:start position:0% +remember py how beautifully he outlined + + + align:start position:0% +remember py how beautifully he outlined +the body as a as a mechanism in his + + align:start position:0% +the body as a as a mechanism in his + + + align:start position:0% +the body as a as a mechanism in his +effort to show that it had this + + align:start position:0% +effort to show that it had this + + + align:start position:0% +effort to show that it had this +wonderful design so so in some sense the + + align:start position:0% +wonderful design so so in some sense the + + + align:start position:0% +wonderful design so so in some sense the +design people now he's coming back to + + align:start position:0% +design people now he's coming back to + + + align:start position:0% +design people now he's coming back to +them because uh pale and showing and + + align:start position:0% +them because uh pale and showing and + + + align:start position:0% +them because uh pale and showing and +other people too I mean I showed you a + + align:start position:0% +other people too I mean I showed you a + + + align:start position:0% +other people too I mean I showed you a +lot of different but in showing the body + + align:start position:0% +lot of different but in showing the body + + + align:start position:0% +lot of different but in showing the body +as this + + align:start position:0% +as this + + + align:start position:0% +as this +mechanism and you know Gray's Anatomy + + align:start position:0% +mechanism and you know Gray's Anatomy + + + align:start position:0% +mechanism and you know Gray's Anatomy +showing all the parts of the body and + + align:start position:0% +showing all the parts of the body and + + + align:start position:0% +showing all the parts of the body and +beautifully dis seting it out and so + + align:start position:0% +beautifully dis seting it out and so + + + align:start position:0% +beautifully dis seting it out and so +forth we see you know body's really a + + align:start position:0% +forth we see you know body's really a + + + align:start position:0% +forth we see you know body's really a +incredible + + align:start position:0% +incredible + + + align:start position:0% +incredible +machine so now we're coming back to you + + align:start position:0% +machine so now we're coming back to you + + + align:start position:0% +machine so now we're coming back to you +know revisiting this from another point + + align:start position:0% +know revisiting this from another point + + + align:start position:0% +know revisiting this from another point +of view well this machine is indeed a + + align:start position:0% +of view well this machine is indeed a + + + align:start position:0% +of view well this machine is indeed a +machine and why should we think of it as + + align:start position:0% +machine and why should we think of it as + + + align:start position:0% +machine and why should we think of it as +a totally different machine from other + + align:start position:0% +a totally different machine from other + + + align:start position:0% +a totally different machine from other +machines yeah it has + + align:start position:0% +machines yeah it has + + + align:start position:0% +machines yeah it has +Consciousness an + + align:start position:0% +Consciousness an + + + align:start position:0% +Consciousness an +intentionality but as this thinker here + + align:start position:0% +intentionality but as this thinker here + + + align:start position:0% +intentionality but as this thinker here +is saying well what is consciousness and + + align:start position:0% +is saying well what is consciousness and + + + align:start position:0% +is saying well what is consciousness and +what is what is intention so he says + + align:start position:0% +what is what is intention so he says + + + align:start position:0% +what is what is intention so he says +here the disturbances + + align:start position:0% +here the disturbances + + + align:start position:0% +here the disturbances +uh those things which we deem most + + align:start position:0% +uh those things which we deem most + + + align:start position:0% +uh those things which we deem most +purely spiritual are anything but + + align:start position:0% +purely spiritual are anything but + + + align:start position:0% +purely spiritual are anything but +disturbances of equilibrium and an + + align:start position:0% +disturbances of equilibrium and an + + + align:start position:0% +disturbances of equilibrium and an +infinite series of levers beginning with + + align:start position:0% +infinite series of levers beginning with + + + align:start position:0% +infinite series of levers beginning with +those that are too small for microscopic + + align:start position:0% +those that are too small for microscopic + + + align:start position:0% +those that are too small for microscopic +detection and going up to the human arm + + align:start position:0% +detection and going up to the human arm + + + align:start position:0% +detection and going up to the human arm +and and the appliances which it makes + + align:start position:0% +and and the appliances which it makes + + + align:start position:0% +and and the appliances which it makes +use of whether there not be a molecular + + align:start position:0% +use of whether there not be a molecular + + + align:start position:0% +use of whether there not be a molecular +action of + + align:start position:0% +action of + + + align:start position:0% +action of +thought that was an outrageous statement + + align:start position:0% +thought that was an outrageous statement + + + align:start position:0% +thought that was an outrageous statement +in Butler's day is it outrageous + + align:start position:0% + + + + align:start position:0% + +today no cognitive scientists in here I + + align:start position:0% +today no cognitive scientists in here I + + + align:start position:0% +today no cognitive scientists in here I +can + + align:start position:0% +can + + + align:start position:0% +can +see brain and Cog go over and ask them + + align:start position:0% +see brain and Cog go over and ask them + + + align:start position:0% +see brain and Cog go over and ask them +is is thought process somehow mechanical + + align:start position:0% +is is thought process somehow mechanical + + + align:start position:0% +is is thought process somehow mechanical +are there mechanical + + align:start position:0% +are there mechanical + + + align:start position:0% +are there mechanical +electrical chemical aspects to it is it + + align:start position:0% +electrical chemical aspects to it is it + + + align:start position:0% +electrical chemical aspects to it is it +uh I'm sure nobody will give you + + align:start position:0% +uh I'm sure nobody will give you + + + align:start position:0% +uh I'm sure nobody will give you +a + + align:start position:0% +a + + + align:start position:0% +a +uh definitive answer but certainly it's + + align:start position:0% +uh definitive answer but certainly it's + + + align:start position:0% +uh definitive answer but certainly it's +it's it's the realm of of uh + + align:start position:0% +it's it's the realm of of uh + + + align:start position:0% +it's it's the realm of of uh +investigation today right here as we + + align:start position:0% +investigation today right here as we + + + align:start position:0% +investigation today right here as we +sit yeah CH well I mean the way the + + align:start position:0% +sit yeah CH well I mean the way the + + + align:start position:0% +sit yeah CH well I mean the way the +nerves work there are it is chemicals + + align:start position:0% +nerves work there are it is chemicals + + + align:start position:0% +nerves work there are it is chemicals +firing in and out of cell Cur electrical + + align:start position:0% +firing in and out of cell Cur electrical + + + align:start position:0% +firing in and out of cell Cur electrical +impulse but I don't know if there can be + + align:start position:0% +impulse but I don't know if there can be + + + align:start position:0% +impulse but I don't know if there can be +cuz I don't think again not not a + + align:start position:0% +cuz I don't think again not not a + + + align:start position:0% +cuz I don't think again not not a +Brandon Cod side but I don't think it's + + align:start position:0% +Brandon Cod side but I don't think it's + + + align:start position:0% +Brandon Cod side but I don't think it's +f understood how those electrical + + align:start position:0% +f understood how those electrical + + + align:start position:0% +f understood how those electrical +impulses translate into like thoughts + + align:start position:0% +impulses translate into like thoughts + + + align:start position:0% +impulses translate into like thoughts +and I mean not cognitive sence we're + + align:start position:0% +and I mean not cognitive sence we're + + + align:start position:0% +and I mean not cognitive sence we're +we're reading a novel but what's + + align:start position:0% +we're reading a novel but what's + + + align:start position:0% +we're reading a novel but what's +interesting is how this this uh this + + align:start position:0% +interesting is how this this uh this + + + align:start position:0% +interesting is how this this uh this +piece of speculation brings up + + align:start position:0% +piece of speculation brings up + + + align:start position:0% +piece of speculation brings up +questions that you know within the + + align:start position:0% +questions that you know within the + + + align:start position:0% +questions that you know within the +framework of evolutionary thinking I + + align:start position:0% +framework of evolutionary thinking I + + + align:start position:0% +framework of evolutionary thinking I +mean he he couldn't have come up with + + align:start position:0% +mean he he couldn't have come up with + + + align:start position:0% +mean he he couldn't have come up with +these questions + + align:start position:0% +these questions + + + align:start position:0% +these questions +without the evolutionary framework + + align:start position:0% +without the evolutionary framework + + + align:start position:0% +without the evolutionary framework +you understand that because he's + + align:start position:0% +you understand that because he's + + + align:start position:0% +you understand that because he's +thinking of it as this kind of + + align:start position:0% +thinking of it as this kind of + + + align:start position:0% +thinking of it as this kind of +incremental process that has delivered + + align:start position:0% +incremental process that has delivered + + + align:start position:0% +incremental process that has delivered +greater and greater functionality over + + align:start position:0% +greater and greater functionality over + + + align:start position:0% +greater and greater functionality over +time and he's saying why not for + + align:start position:0% +time and he's saying why not for + + + align:start position:0% +time and he's saying why not for +mechanical devices so he's jumping + + align:start position:0% +mechanical devices so he's jumping + + + align:start position:0% +mechanical devices so he's jumping +directly from organic to what we would + + align:start position:0% +directly from organic to what we would + + + align:start position:0% +directly from organic to what we would +call the inorganic + + align:start position:0% +call the inorganic + + + align:start position:0% +call the inorganic +world but he's saying look you know + + align:start position:0% +world but he's saying look you know + + + align:start position:0% +world but he's saying look you know +these + + align:start position:0% +these + + + align:start position:0% +these +parallels are not outr + + align:start position:0% +parallels are not outr + + + align:start position:0% +parallels are not outr +rageous and we can use one to think + + align:start position:0% +rageous and we can use one to think + + + align:start position:0% +rageous and we can use one to think +about the other so yeah we we can't come + + align:start position:0% +about the other so yeah we we can't come + + + align:start position:0% +about the other so yeah we we can't come +to a definitive answer here on you know + + align:start position:0% +to a definitive answer here on you know + + + align:start position:0% +to a definitive answer here on you know +the question but we know that the + + align:start position:0% +the question but we know that the + + + align:start position:0% +the question but we know that the +question is not an outrageous question + + align:start position:0% +question is not an outrageous question + + + align:start position:0% +question is not an outrageous question +any + + align:start position:0% +any + + + align:start position:0% +any +longer and the theories and arguments in + + align:start position:0% +longer and the theories and arguments in + + + align:start position:0% +longer and the theories and arguments in +this outrageous as they were in their + + align:start position:0% +this outrageous as they were in their + + + align:start position:0% +this outrageous as they were in their +time when he uh says man is a masate + + align:start position:0% +time when he uh says man is a masate + + + align:start position:0% +time when he uh says man is a masate +animal I mean yeah we are merging with + + align:start position:0% +animal I mean yeah we are merging with + + + align:start position:0% +animal I mean yeah we are merging with +machines we do all sorts of weird things + + align:start position:0% +machines we do all sorts of weird things + + + align:start position:0% +machines we do all sorts of weird things +with machines but certainly machines + + align:start position:0% +with machines but certainly machines + + + align:start position:0% +with machines but certainly machines +have U extended our + + align:start position:0% +have U extended our + + + align:start position:0% +have U extended our +functionality in dramatic + + align:start position:0% +functionality in dramatic + + + align:start position:0% +functionality in dramatic +ways and so there's a there's + + align:start position:0% +ways and so there's a there's + + + align:start position:0% +ways and so there's a there's +uh I mean this this uh limb here you + + align:start position:0% +uh I mean this this uh limb here you + + + align:start position:0% +uh I mean this this uh limb here you +know they're are people using artificial + + align:start position:0% +know they're are people using artificial + + + align:start position:0% +know they're are people using artificial +limbs that are highly + + align:start position:0% +limbs that are highly + + + align:start position:0% +limbs that are highly +functional and have merged with in you + + align:start position:0% +functional and have merged with in you + + + align:start position:0% +functional and have merged with in you +know I suppose you could do a thought + + align:start position:0% +know I suppose you could do a thought + + + align:start position:0% +know I suppose you could do a thought +experiment I'm going to have to break + + align:start position:0% +experiment I'm going to have to break + + + align:start position:0% +experiment I'm going to have to break +here soon because I I have to leave + + align:start position:0% +here soon because I I have to leave + + + align:start position:0% +here soon because I I have to leave +early today but uh a person could do a + + align:start position:0% +early today but uh a person could do a + + + align:start position:0% +early today but uh a person could do a +thought experiment and say well how many + + align:start position:0% +thought experiment and say well how many + + + align:start position:0% +thought experiment and say well how many +different + + align:start position:0% +different + + + align:start position:0% +different +artificial things do we have for the + + align:start position:0% +artificial things do we have for the + + + align:start position:0% +artificial things do we have for the +body today we have artificial hands we + + align:start position:0% +body today we have artificial hands we + + + align:start position:0% +body today we have artificial hands we +have artificial limbs we have AR we're + + align:start position:0% +have artificial limbs we have AR we're + + + align:start position:0% +have artificial limbs we have AR we're +working on artificial Hearts we're + + align:start position:0% +working on artificial Hearts we're + + + align:start position:0% +working on artificial Hearts we're +working on + + align:start position:0% +working on + + + align:start position:0% +working on +artificial I don't know all kinds of + + align:start position:0% +artificial I don't know all kinds of + + + align:start position:0% +artificial I don't know all kinds of +artificial things + + align:start position:0% +artificial things + + + align:start position:0% +artificial things +so if we did a thought experiment and we + + align:start position:0% +so if we did a thought experiment and we + + + align:start position:0% +so if we did a thought experiment and we +replaced a + + align:start position:0% +replaced a + + + align:start position:0% +replaced a +person every single part with something + + align:start position:0% +person every single part with something + + + align:start position:0% +person every single part with something +artificial if we could all make it if we + + align:start position:0% +artificial if we could all make it if we + + + align:start position:0% +artificial if we could all make it if we +can make it all work together we might + + align:start position:0% +can make it all work together we might + + + align:start position:0% +can make it all work together we might +eventually end up with entirely + + align:start position:0% +eventually end up with entirely + + + align:start position:0% +eventually end up with entirely +mechanical entity when do they actually + + align:start position:0% +mechanical entity when do they actually + + + align:start position:0% +mechanical entity when do they actually +die yeah that's a good + + align:start position:0% +die yeah that's a good + + + align:start position:0% +die yeah that's a good +question I mean dve would the like + + align:start position:0% +question I mean dve would the like + + + align:start position:0% +question I mean dve would the like +regrowth of organs be considered + + align:start position:0% +regrowth of organs be considered + + + align:start position:0% +regrowth of organs be considered +artificial as well well that's a that's + + align:start position:0% +artificial as well well that's a that's + + + align:start position:0% +artificial as well well that's a that's +a that's a good question um because we + + align:start position:0% +a that's a good question um because we + + + align:start position:0% +a that's a good question um because we +can + + align:start position:0% +can + + + align:start position:0% +can +start we can start making our + + align:start position:0% +start we can start making our + + + align:start position:0% +start we can start making our +own + + align:start position:0% +own + + + align:start position:0% +own +organic + + align:start position:0% +organic + + + align:start position:0% +organic +objects so uh this is a huge area of + + align:start position:0% +objects so uh this is a huge area of + + + align:start position:0% +objects so uh this is a huge area of +research that people are engaged in and + + align:start position:0% +research that people are engaged in and + + + align:start position:0% +research that people are engaged in and +so to what degree is that a human + + align:start position:0% +so to what degree is that a human + + + align:start position:0% +so to what degree is that a human +fabrication I.E in some sense of + + align:start position:0% +fabrication I.E in some sense of + + + align:start position:0% +fabrication I.E in some sense of +mechanical + + align:start position:0% +mechanical + + + align:start position:0% +mechanical +device only the mechanics are a bi + + align:start position:0% +device only the mechanics are a bi + + + align:start position:0% +device only the mechanics are a bi +biological mechanics that we have become + + align:start position:0% +biological mechanics that we have become + + + align:start position:0% +biological mechanics that we have become +so good at that we're beginning to + + align:start position:0% +so good at that we're beginning to + + + align:start position:0% +so good at that we're beginning to +build the biology and it's you know it's + + align:start position:0% +build the biology and it's you know it's + + + align:start position:0% +build the biology and it's you know it's +not made up of + + align:start position:0% +not made up of + + + align:start position:0% +not made up of +uh all these inorganic things we're + + align:start position:0% +uh all these inorganic things we're + + + align:start position:0% +uh all these inorganic things we're +building it out of organic tools and + + align:start position:0% +building it out of organic tools and + + + align:start position:0% +building it out of organic tools and +organic + + align:start position:0% +organic + + + align:start position:0% +organic +materials so you know where are the + + align:start position:0% +materials so you know where are the + + + align:start position:0% +materials so you know where are the +lines so that's that's what this is is + + align:start position:0% +lines so that's that's what this is is + + + align:start position:0% +lines so that's that's what this is is +is is is dealing about is dealing with + + align:start position:0% +is is is dealing about is dealing with + + + align:start position:0% +is is is dealing about is dealing with +is you know these lines that we think + + align:start position:0% +is you know these lines that we think + + + align:start position:0% +is you know these lines that we think +are so clear from a distance when we get + + align:start position:0% +are so clear from a distance when we get + + + align:start position:0% +are so clear from a distance when we get +closer and closer up aren't so + + align:start position:0% +closer and closer up aren't so + + + align:start position:0% +closer and closer up aren't so +clear and it's uh it's it's it's worth + + align:start position:0% +clear and it's uh it's it's it's worth + + + align:start position:0% +clear and it's uh it's it's it's worth +thinking about + + align:start position:0% + + + + align:start position:0% + +um okay + + align:start position:0% +um okay + + + align:start position:0% +um okay +well it's a you know it's it's a fun + + align:start position:0% +well it's a you know it's it's a fun + + + align:start position:0% +well it's a you know it's it's a fun +chapter three chapters mainly because + + align:start position:0% +chapter three chapters mainly because + + + align:start position:0% +chapter three chapters mainly because +you know he talks about reproduction you + + align:start position:0% +you know he talks about reproduction you + + + align:start position:0% +you know he talks about reproduction you +know yes the machine to be reproduced + + align:start position:0% +know yes the machine to be reproduced + + + align:start position:0% +know yes the machine to be reproduced +outside of the body of the other machine + + align:start position:0% +outside of the body of the other machine + + + align:start position:0% +outside of the body of the other machine +but you know there are precedents for + + align:start position:0% +but you know there are precedents for + + + align:start position:0% +but you know there are precedents for +things like this in + + align:start position:0% +things like this in + + + align:start position:0% +things like this in +nature just because reproduction takes + + align:start position:0% +nature just because reproduction takes + + + align:start position:0% +nature just because reproduction takes +place on the factory + + align:start position:0% +place on the factory + + + align:start position:0% +place on the factory +line uh it's you know things are being + + align:start position:0% +line uh it's you know things are being + + + align:start position:0% +line uh it's you know things are being +produced and they're following certain + + align:start position:0% +produced and they're following certain + + + align:start position:0% +produced and they're following certain +models and so uh and these models are + + align:start position:0% +models and so uh and these models are + + + align:start position:0% +models and so uh and these models are +evolving into greater and greater + + align:start position:0% +evolving into greater and greater + + + align:start position:0% +evolving into greater and greater +functionality uh according to our our + + align:start position:0% +functionality uh according to our our + + + align:start position:0% +functionality uh according to our our +desires so this is where the design part + + align:start position:0% +desires so this is where the design part + + + align:start position:0% +desires so this is where the design part +of the human and the design part of the + + align:start position:0% +of the human and the design part of the + + + align:start position:0% +of the human and the design part of the +natural sort of + + align:start position:0% + + + + align:start position:0% + +merge \ No newline at end of file diff --git a/8DlysThtgbM.txt b/8DlysThtgbM.txt new file mode 100644 index 0000000000000000000000000000000000000000..c72d3e0433a3e192355d87ae3f65ad7a0f9b7c81 --- /dev/null +++ b/8DlysThtgbM.txt @@ -0,0 +1,1211 @@ +align:start position:0% + +so just imagine that instead of this is + + align:start position:0% +so just imagine that instead of this is + + + align:start position:0% +so just imagine that instead of this is +for two choices two outcomes two stages + + align:start position:0% +for two choices two outcomes two stages + + + align:start position:0% +for two choices two outcomes two stages +just a match extension of three of each + + align:start position:0% +just a match extension of three of each + + + align:start position:0% +just a match extension of three of each +and you're now talking about a really + + align:start position:0% +and you're now talking about a really + + + align:start position:0% +and you're now talking about a really +really complicated and i have just to + + align:start position:0% +really complicated and i have just to + + + align:start position:0% +really complicated and i have just to +set up and i haven't deliberately i + + align:start position:0% +set up and i haven't deliberately i + + + align:start position:0% +set up and i haven't deliberately i +haven't tried to show you the way to + + align:start position:0% +haven't tried to show you the way to + + + align:start position:0% +haven't tried to show you the way to +calculate the revisions of the prior + + align:start position:0% +calculate the revisions of the prior + + + align:start position:0% +calculate the revisions of the prior +probabilities and learn about the future + + align:start position:0% +probabilities and learn about the future + + + align:start position:0% +probabilities and learn about the future +bottom line here is there's a good + + align:start position:0% +bottom line here is there's a good + + + align:start position:0% +bottom line here is there's a good +chance of a messy bush + + align:start position:0% +chance of a messy bush + + + align:start position:0% +chance of a messy bush +so + + align:start position:0% +so + + + align:start position:0% +so +uh + + align:start position:0% +uh + + + align:start position:0% +uh +it's uh + + align:start position:0% +it's uh + + + align:start position:0% +it's uh +something to warn you about + + align:start position:0% +something to warn you about + + + align:start position:0% +something to warn you about +and + + align:start position:0% +and + + + align:start position:0% +and +um + + align:start position:0% +um + + + align:start position:0% +um +there's a reason however to show you + + align:start position:0% +there's a reason however to show you + + + align:start position:0% +there's a reason however to show you +this and the which is one of which is + + align:start position:0% +this and the which is one of which is + + + align:start position:0% +this and the which is one of which is +because other people use it as + + align:start position:0% +because other people use it as + + + align:start position:0% +because other people use it as +chevron's this uh decision analysis + + align:start position:0% +chevron's this uh decision analysis + + + align:start position:0% +chevron's this uh decision analysis +manual but it also allows you at least + + align:start position:0% +manual but it also allows you at least + + + align:start position:0% +manual but it also allows you at least +to have some insight insights into + + align:start position:0% +to have some insight insights into + + + align:start position:0% +to have some insight insights into +something important which is the value + + align:start position:0% +something important which is the value + + + align:start position:0% +something important which is the value +of information which will be the topic + + align:start position:0% +of information which will be the topic + + + align:start position:0% +of information which will be the topic +of la of next time + + align:start position:0% +of la of next time + + + align:start position:0% +of la of next time +so + + align:start position:0% +so + + + align:start position:0% +so +um + + align:start position:0% +um + + + align:start position:0% +um +let's now step back a little bit from it + + align:start position:0% +let's now step back a little bit from it + + + align:start position:0% +let's now step back a little bit from it +but to realize that with the end + + align:start position:0% +but to realize that with the end + + + align:start position:0% +but to realize that with the end +as a result of the decision analysis we + + align:start position:0% +as a result of the decision analysis we + + + align:start position:0% +as a result of the decision analysis we +don't have a simple plan so and + + align:start position:0% +don't have a simple plan so and + + + align:start position:0% +don't have a simple plan so and +instead of saying all right + + align:start position:0% +instead of saying all right + + + align:start position:0% +instead of saying all right +we must our best approach is to listen + + align:start position:0% +we must our best approach is to listen + + + align:start position:0% +we must our best approach is to listen +to the weather forecast and then to take + + align:start position:0% +to the weather forecast and then to take + + + align:start position:0% +to the weather forecast and then to take +the raincoat + + align:start position:0% +the raincoat + + + align:start position:0% +the raincoat +no it's to listen to the weather + + align:start position:0% +no it's to listen to the weather + + + align:start position:0% +no it's to listen to the weather +forecast if one thing happens then maybe + + align:start position:0% +forecast if one thing happens then maybe + + + align:start position:0% +forecast if one thing happens then maybe +we take the raincoat if + + align:start position:0% +we take the raincoat if + + + align:start position:0% +we take the raincoat if +another thing happens then we don't take + + align:start position:0% +another thing happens then we don't take + + + align:start position:0% +another thing happens then we don't take +the raincoat so it is + + align:start position:0% +the raincoat so it is + + + align:start position:0% +the raincoat so it is +not okay + + align:start position:0% +not okay + + + align:start position:0% +not okay +step one phase one phase two phase three + + align:start position:0% +step one phase one phase two phase three + + + align:start position:0% +step one phase one phase two phase three +here is the right choice it is okay + + align:start position:0% +here is the right choice it is okay + + + align:start position:0% +here is the right choice it is okay +here is the right start + + align:start position:0% +here is the right start + + + align:start position:0% +here is the right start +and then we should + + align:start position:0% +and then we should + + + align:start position:0% +and then we should +do something else later on so for + + align:start position:0% +do something else later on so for + + + align:start position:0% +do something else later on so for +example + + align:start position:0% +example + + + align:start position:0% +example +you might say + + align:start position:0% +you might say + + + align:start position:0% +you might say +the first stage is to build your planet + + align:start position:0% +the first stage is to build your planet + + + align:start position:0% +the first stage is to build your planet +in the second phase if there's growth + + align:start position:0% +in the second phase if there's growth + + + align:start position:0% +in the second phase if there's growth +expand it + + align:start position:0% +expand it + + + align:start position:0% +expand it +if there's no particular growth + + align:start position:0% +if there's no particular growth + + + align:start position:0% +if there's no particular growth +don't do anything + + align:start position:0% +don't do anything + + + align:start position:0% +don't do anything +if it's failing + + align:start position:0% +if it's failing + + + align:start position:0% +if it's failing +then + + align:start position:0% +then + + + align:start position:0% +then +close it for example so you can you + + align:start position:0% +close it for example so you can you + + + align:start position:0% +close it for example so you can you +don't have one plan + + align:start position:0% +don't have one plan + + + align:start position:0% +don't have one plan +you have you have a strategy a dynamic + + align:start position:0% +you have you have a strategy a dynamic + + + align:start position:0% +you have you have a strategy a dynamic +plan that uh + + align:start position:0% +plan that uh + + + align:start position:0% +plan that uh +lasts through time + + align:start position:0% +lasts through time + + + align:start position:0% +lasts through time +now coming back to the decision analysis + + align:start position:0% +now coming back to the decision analysis + + + align:start position:0% +now coming back to the decision analysis +consequences + + align:start position:0% +consequences + + + align:start position:0% +consequences +is it going through this kind of process + + align:start position:0% +is it going through this kind of process + + + align:start position:0% +is it going through this kind of process +of showing the complexity of it is an + + align:start position:0% +of showing the complexity of it is an + + + align:start position:0% +of showing the complexity of it is an +education for the client + + align:start position:0% +education for the client + + + align:start position:0% +education for the client +for the person you're trying to do + + align:start position:0% +for the person you're trying to do + + + align:start position:0% +for the person you're trying to do +and it also shows a strategy a dynamic + + align:start position:0% +and it also shows a strategy a dynamic + + + align:start position:0% +and it also shows a strategy a dynamic +plan is better than having a step one + + align:start position:0% +plan is better than having a step one + + + align:start position:0% +plan is better than having a step one +step two step three a phased this is + + align:start position:0% +step two step three a phased this is + + + align:start position:0% +step two step three a phased this is +what we're going to do through time we + + align:start position:0% +what we're going to do through time we + + + align:start position:0% +what we're going to do through time we +just generally they don't work out that + + align:start position:0% +just generally they don't work out that + + + align:start position:0% +just generally they don't work out that +way anyway + + align:start position:0% +way anyway + + + align:start position:0% +way anyway +moreover often it's the second best + + align:start position:0% +moreover often it's the second best + + + align:start position:0% +moreover often it's the second best +strategy that is optimal for winning any + + align:start position:0% +strategy that is optimal for winning any + + + align:start position:0% +strategy that is optimal for winning any +one outcome for example it's best to buy + + align:start position:0% +one outcome for example it's best to buy + + + align:start position:0% +one outcome for example it's best to buy +insurance + + align:start position:0% +insurance + + + align:start position:0% +insurance +so thinking about + + align:start position:0% +so thinking about + + + align:start position:0% +so thinking about +um you can choose to have a car or not + + align:start position:0% +um you can choose to have a car or not + + + align:start position:0% +um you can choose to have a car or not +if you if it's within your means + + align:start position:0% +if you if it's within your means + + + align:start position:0% +if you if it's within your means +and then if you have an accident + + align:start position:0% +and then if you have an accident + + + align:start position:0% +and then if you have an accident +and you're + + align:start position:0% +and you're + + + align:start position:0% +and you're +really hurt and everything + + align:start position:0% +really hurt and everything + + + align:start position:0% +really hurt and everything +you could look back and say driving was + + align:start position:0% +you could look back and say driving was + + + align:start position:0% +you could look back and say driving was +not a good idea + + align:start position:0% +not a good idea + + + align:start position:0% +not a good idea +um + + align:start position:0% +um + + + align:start position:0% +um +and it would have been better not to + + align:start position:0% +and it would have been better not to + + + align:start position:0% +and it would have been better not to +drive at all + + align:start position:0% +drive at all + + + align:start position:0% +drive at all +if you have no accident you might say + + align:start position:0% +if you have no accident you might say + + + align:start position:0% +if you have no accident you might say +gee i did i + + align:start position:0% +gee i did i + + + align:start position:0% +gee i did i +my best choice would have been to + + align:start position:0% +my best choice would have been to + + + align:start position:0% +my best choice would have been to +not have insurance + + align:start position:0% +not have insurance + + + align:start position:0% +not have insurance +insurance was a bad idea to have because + + align:start position:0% +insurance was a bad idea to have because + + + align:start position:0% +insurance was a bad idea to have because +i didn't use it + + align:start position:0% +i didn't use it + + + align:start position:0% +i didn't use it +so the optimal choice would might be to + + align:start position:0% +so the optimal choice would might be to + + + align:start position:0% +so the optimal choice would might be to +drive with insurance which is never the + + align:start position:0% +drive with insurance which is never the + + + align:start position:0% +drive with insurance which is never the +best which would not be the best choice + + align:start position:0% +best which would not be the best choice + + + align:start position:0% +best which would not be the best choice +your first core choice in terms of the + + align:start position:0% +your first core choice in terms of the + + + align:start position:0% +your first core choice in terms of the +outcomes if the outcomes + + align:start position:0% +outcomes if the outcomes + + + align:start position:0% +outcomes if the outcomes +um were that you didn't have any + + align:start position:0% +um were that you didn't have any + + + align:start position:0% +um were that you didn't have any +accident you spent all that money that + + align:start position:0% +accident you spent all that money that + + + align:start position:0% +accident you spent all that money that +you didn't need to + + align:start position:0% +you didn't need to + + + align:start position:0% +you didn't need to +that would have been the better choice + + align:start position:0% +that would have been the better choice + + + align:start position:0% +that would have been the better choice +if you did have a bad accident then + + align:start position:0% +if you did have a bad accident then + + + align:start position:0% +if you did have a bad accident then +maybe you shouldn't have been into doing + + align:start position:0% +maybe you shouldn't have been into doing + + + align:start position:0% +maybe you shouldn't have been into doing +that kind of activity anyway + + align:start position:0% +that kind of activity anyway + + + align:start position:0% +that kind of activity anyway +so it's the idea that + + align:start position:0% +so it's the idea that + + + align:start position:0% +so it's the idea that +the better choice like to drive + + align:start position:0% +the better choice like to drive + + + align:start position:0% +the better choice like to drive +insurance is never the best choice for + + align:start position:0% +insurance is never the best choice for + + + align:start position:0% +insurance is never the best choice for +all is not necessarily the best choice + + align:start position:0% +all is not necessarily the best choice + + + align:start position:0% +all is not necessarily the best choice +for all the possible outcomes + + align:start position:0% + + + + align:start position:0% + +so let me now step back and put this + + align:start position:0% +so let me now step back and put this + + + align:start position:0% +so let me now step back and put this +decision analysis versus flexibility + + align:start position:0% +decision analysis versus flexibility + + + align:start position:0% +decision analysis versus flexibility +analysis so this decision analysis + + align:start position:0% +analysis so this decision analysis + + + align:start position:0% +analysis so this decision analysis +assumes you can + + align:start position:0% +assumes you can + + + align:start position:0% +assumes you can +define the choices to take in any stages + + align:start position:0% +define the choices to take in any stages + + + align:start position:0% +define the choices to take in any stages +that's essential to building your + + align:start position:0% +that's essential to building your + + + align:start position:0% +that's essential to building your +decision trees to say + + align:start position:0% +decision trees to say + + + align:start position:0% +decision trees to say +at stage two here's what i can do at + + align:start position:0% +at stage two here's what i can do at + + + align:start position:0% +at stage two here's what i can do at +stage three here's what i can do + + align:start position:0% +stage three here's what i can do + + + align:start position:0% +stage three here's what i can do +contrarily decision and flexibility + + align:start position:0% +contrarily decision and flexibility + + + align:start position:0% +contrarily decision and flexibility +encourage you to explore what decision + + align:start position:0% +encourage you to explore what decision + + + align:start position:0% +encourage you to explore what decision +to take and when to take them + + align:start position:0% +to take and when to take them + + + align:start position:0% +to take and when to take them +it doesn't tell you what you have to do + + align:start position:0% +it doesn't tell you what you have to do + + + align:start position:0% +it doesn't tell you what you have to do +and it doesn't tell you when to do it so + + align:start position:0% +and it doesn't tell you when to do it so + + + align:start position:0% +and it doesn't tell you when to do it so +the simulation analysis allows you to + + align:start position:0% +the simulation analysis allows you to + + + align:start position:0% +the simulation analysis allows you to +look at those + + align:start position:0% +look at those + + + align:start position:0% +look at those +easily + + align:start position:0% +easily + + + align:start position:0% +easily +secondly + + align:start position:0% +secondly + + + align:start position:0% +secondly +the decision analysis focuses on a few + + align:start position:0% +the decision analysis focuses on a few + + + align:start position:0% +the decision analysis focuses on a few +distinct choices we do this that or the + + align:start position:0% +distinct choices we do this that or the + + + align:start position:0% +distinct choices we do this that or the +other + + align:start position:0% +other + + + align:start position:0% +other +whereas a flexibility analysis + + align:start position:0% +whereas a flexibility analysis + + + align:start position:0% +whereas a flexibility analysis +allows you via excel to be as granular + + align:start position:0% +allows you via excel to be as granular + + + align:start position:0% +allows you via excel to be as granular +as you as desired you can look through 2 + + align:start position:0% +as you as desired you can look through 2 + + + align:start position:0% +as you as desired you can look through 2 +000 simulations and it's easy to do does + + align:start position:0% +000 simulations and it's easy to do does + + + align:start position:0% +000 simulations and it's easy to do does +it in seconds but + + align:start position:0% +it in seconds but + + + align:start position:0% +it in seconds but +this is not really possible on + + align:start position:0% +this is not really possible on + + + align:start position:0% +this is not really possible on +with decision analysis so + + align:start position:0% +with decision analysis so + + + align:start position:0% +with decision analysis so +having said that + + align:start position:0% +having said that + + + align:start position:0% +having said that +well it emphasizes the reasons why uh + + align:start position:0% +well it emphasizes the reasons why uh + + + align:start position:0% +well it emphasizes the reasons why uh +decision analysis which was popular um + + align:start position:0% +decision analysis which was popular um + + + align:start position:0% +decision analysis which was popular um +and + + align:start position:0% +and + + + align:start position:0% +and +was a breakthrough frankly speaking uh + + align:start position:0% +was a breakthrough frankly speaking uh + + + align:start position:0% +was a breakthrough frankly speaking uh +into thinking uh a long time ago for me + + align:start position:0% +into thinking uh a long time ago for me + + + align:start position:0% +into thinking uh a long time ago for me +a long time ago for before you were born + + align:start position:0% +a long time ago for before you were born + + + align:start position:0% +a long time ago for before you were born +even perhaps possibly um it is really + + align:start position:0% +even perhaps possibly um it is really + + + align:start position:0% +even perhaps possibly um it is really +not so relevant uh today although it + + align:start position:0% +not so relevant uh today although it + + + align:start position:0% +not so relevant uh today although it +does exist and is used and has some + + align:start position:0% +does exist and is used and has some + + + align:start position:0% +does exist and is used and has some +insights which + + align:start position:0% +insights which + + + align:start position:0% +insights which +i'll be sharing with you in terms of + + align:start position:0% +i'll be sharing with you in terms of + + + align:start position:0% +i'll be sharing with you in terms of +value of information \ No newline at end of file diff --git a/8O2EPwUtWyY.txt b/8O2EPwUtWyY.txt new file mode 100644 index 0000000000000000000000000000000000000000..dff99b4762d528d033e244d511ac19e82e780ce1 --- /dev/null +++ b/8O2EPwUtWyY.txt @@ -0,0 +1,3091 @@ +Hello, everyone. + +Welcome. + +I'm Krishna Rajagopal, MIT's +Dean for Digital Learning. + +And I'm here to welcome +everyone to this joyous occasion + +as OpenCourseWare turns 20. + +Today, we celebrate +OCW's first 20 years, + +and look ahead to the potential +and the plans for OCW, + +and the entire ecosystem of +open educational resources + +that OCW sits within, +in its next 20. + +The mission of OCW +since its founding + +was to unlock knowledge +and empower minds + +by publishing materials from +virtually all MIT courses, + +and extend the reach of those +materials via the OER movement + +which OCW played a +key role in seeding. + +Charles Vest, who is +the president of MIT who + +launched OCW 20 years +ago, spoke at that time + +about how surprising and +audacious the vision of OCW + +that came to him from a founding +group of MIT faculty members + +was. + +Put all of our materials +on the internet, openly? + +This came as a big surprise to +President Vest 20 years ago. + +One way to see how right +the faculty were back then, + +those founding faculty, +is to say that today, + +sharing our pedagogy, our +perspective, our insights, + +openly via OCW is simply +unquestioned at MIT. + +It's seen as just a +part of what we do. + +It comes from who we are. + +Of course we do this. + +And the fact that so much +has changed in 20 years + +is a sign that the +founders, the pioneers, + +were as right as +in fact, they were. + +So, jumping ahead today, +let's look at OCW today. + +2,500 courses on OCW. + +Material from 2,500 courses. + +From 1,700 MIT instructors. + +OCW is the largest .edu +YouTube channel in the world, + +with 2.97 million subscribers. + +And over the history of +that YouTube channel, + +more than 2 billion minutes +of learning on that YouTube + +channel. + +And I'll remind you that OCW +was founded long before YouTube. + +And the idea that OCW would +include video in this way + +was something that came after +the founding, it's more recent. + +And yet, here we are. + +What about the OCW website, +which is where it all began? + +To date, 210 million +visitors to the OCW website. + +And just time on +the website itself, + +more than a billion +minutes of learning. + +And really, untold +billions, we don't + +know how many more +billions, of minutes + +of learning that OCW has +made possible, as people + +use the materials +from the website. + +Download a problem +set, learn by doing. + +As people share the +materials from that website. + +As people teach +their own students + +using the materials +from that website. + +The learning that has resulted +as a consequence of OCW + +is inestimable. + +And furthermore, +the magic of OER + +is that these materials morph, +and get reshaped, and shared, + +and ripple outwards +in myriad ways, + +as educators and organizations +within the OER world + +take them and make +them their own. + +For all of this, we, and +millions around the world, + +owe our thanks to so many. + +Let me first thank the founding +generation, the faculty who + +were there at the +beginning who had + +the-- created the +vision of OCW, one of whom + +you'll be hearing +from later today. + +I also want to thank 1,700 +MIT faculty and instructors + +who have contributed, +and continue + +to contribute, their +insights from their teaching, + +the artifacts of their teaching, +the products of their labors, + +what they've created +as they teach + +on campus in MIT's classrooms. + +Next, I want to thank +thousands and thousands + +of generous supporters who +have made this all possible, + +including two key foundations, +the William and Flora Hewlett + +Foundation, and the Andrew +W. Mellon Foundation, + +without whom none of +this would have happened. + +I also want to thank key +corporate supporters, of whom + +there are a number, including +in particular Ab Initio + +and MathWorks, as well as +major individual supporters, + +including people like +MIT alum John Gruber, + +and thousands more. + +And some of the supporters, many +of these supporters, in fact, + +are here with us today, all of +whose generosity we gratefully + +acknowledge today as a +part of this celebration. + +And last but far from least, I +want to thank the devoted OCW + +team itself. + +17 devoted people who make +the magic of OCW happen. + +Their work, their +continuing efforts, + +realizes MIT's +sustained and ongoing + +institutional commitment to OCW, +for which we're also grateful. + +For the institutional +commitment to OCW, + +this wonderful incarnation +of MIT's mission and values. + +If you look at the +mission of MIT, + +you see creating, sharing, +and preserving knowledge. + +OCW does that in spades. + +And then you see a +phrase in the mission + +that says that MIT is committed +to working with others, + +to bring knowledge to bear on +the world's great challenges. + +As we look to the future, +now, to the evolving place + +of OCW in the OER landscape, +OER is the embodiment, for OCW, + +of working with others +to bring knowledge + +to bear on the great +challenges of the world. + +We see a path, as we +look ahead, to going + +from the magnificent access +that OCW has already created-- + +access to knowledge, +access to learning, + +access to MIT's teaching. + +Going forward, we see +a path from that access + +to greater equity. + +And the way to get +from access to equity + +involves collaboration. + +Collaboration with educators and +OER institutions, each of whom + +bring knowledge to people +whom they know well, + +to people in widely varying +contexts with widely + +varying starting points. + +This is a key part of our +vision for the future. + +So we will return to +the OCW of the future + +at the end of the hour, after +hearing from a distinguished + +panel. + +But first, let's kick +this birthday party + +off with a +magnificent video that + +was produced by Joe McMaster +and MIT Video Production. + +In creating OCW, MIT +launched a quiet but profound + +educational revolution. + +It unleashed the global +open-sharing movement, + +and helped pave the way for +the worldwide phenomenon + +of open digital learning. + +What are two or three +words to describe + +OpenCourseWare's impact? + +I would say knowledge and scale. + +Eye-opening. + +Enlightening. + +Choose your own adventure. + +A whole new world. + +Wow, 20 years of +MIT's OpenCourseWare. + +It's just amazing +to think about. + +We've had more than 200 +million people come to OCW + +and learn from the materials +that MIT is sharing. + +My initial introduction +to OpenCourseWare + +was actually at Bunker +Hill Community College. + +My linear algebra +professor would give us + +these weekly quizzes. + +We told her it was hard, +and she said, actually, + +this is an MIT quiz. + +And I was kind of blown away +that I did some part of it. + +And when I inquired how +she got the quiz, she said, + +oh, there's this thing +called MIT OpenCourseWare. + +It imparted me with +this confidence of oh, + +I can do this. + +I can survive an MIT course. + +And that drove me to say, +maybe I can thrive at MIT. + +OCW was the pioneer. + +It opened everybody's +eyes to the possibility + +of connecting to learners who +are in different countries, + +and different situations, +different ages. + +We are making MIT OCW available +in universities and community + +libraries which do not +have internet connection. + +It has encouraged me to learn, +to find out about things, + +to understand and to apply. + +There is so much that can be +achieved by just giving people + +complete, wide open +access to this knowledge + +that they can use +whenever, wherever. + +As much as they need, +as little as they need. + +It takes this very kind of +privileged and elite education + +that we make accessible +to our students, + +and opens it up to +a broader public. + +The very existence of MIT's +OpenCourseWare is inspiring. + +It's a shining example +for institutions of higher + +education around the world. + +I think there's also +great value in showing + +the range of disciplines +that are taught at MIT, + +and showing the fact that the +humanities and social sciences + +are as much a strength of what +MIT has to offer as the STEM + +disciplines. + +This course that I created +is now part of the record, + +and is now something that +someone else can build on. + +Everything is there, even the +syllabus, even the instructions + +of the teacher's, +thesis, assignments. + +OCW is, perhaps, one of the +best things that has happened + +to education Worldwide. + +It's like being so unselfish. + +You're giving everything +of what you have, + +and sharing it with +the other people, + +especially in developing +countries like the Philippines. + +OpenCourseWare quite +literally changed my life. + +It gave me the education +I needed when there wasn't + +another place to find it. + +You're giving people +the tools that + +will allow them to +achieve their potential. + +We have real problems in the +world that need to be solved, + +and we need problem solvers +from every area of the planet + +to work on these. + +We've created this powerful +foundation of free access + +to knowledge, and together +we'll keep growing it. + +We're creating better ways +for learners and teachers + +to find and to use +that OCW content. + +And we'll keep sharing +that vibrant reflection + +of the teaching and +creativity from MIT. + +As we think about equity, we +think about collaborators, + +so that we can bring +more people, starting + +from different starting points, +coming in different ways, + +to the point that they +can learn from OCW. + +Together, we're +forging new paths + +where everyone's contributing to +the world's growing knowledge. + +And we're all using and sharing +that knowledge every day + +to solve the world's +great challenges. + +I want OCW to attract people. + +So it's not just a neutral, +if you want it come get it, + +I want OCW to be calling on +people to educate themselves, + +to empower themselves, +to build and to have + +the necessary tools to do +what they think is important. + +And I'm hoping that, over time, +this snowball from 20 years ago + +becomes an avalanche of +intellectual exchange + +amongst humanity. + +All right, well that was +deeply inspiring for me + +to watch every time I see it. + +And I'm really glad that we +could share that with you. + +Next, we're going to +have a live conversation + +with several people +from the MIT community + +who've made this possible, +continue to make it possible, + +and are leading us +together into the future. + +My name is Curt Newton as +Director of OpenCourseWare. + +I joined the team shortly +after it launched in 2004, + +and I've been director +for the last few years. + +And I'm happy to introduce +now my four co-panelists, Hal + +Abelson, professor +of Computer Science + +and Engineering, part of +the original faculty team + +who conceived of OpenCourseWare. + +He was a very busy +guy around 2000, 2001, + +also helping launch things like +the Creative Commons, which + +we are so glad to be partners +in this enterprise with. + +Mussie Demisse, +current MIT undergrad + +who we were introduced +to in that video. + +As we heard, transferred to MIT +after studying computer science + +at Bunker Hill +Community College, + +and we've been really +glad to work with him + +this year on our +advisory committee. + +Anjali Sastry, senior lecturer +at Sloan School of Management + +and founder of MIT Sloan's +GlobalHealth Lab, where she's + +been building collaborations +engaging students + +around the world to +improve healthcare + +in places like sub-Saharan +Africa and South Asia. + +And last but not least, Mike +Short, Associate Professor + +of Nuclear Science +and Engineering. + +He started as a student at MIT +right when OCW was launched. + +Completed his master's in 2005, +completed a doctorate in 2010, + +and is now a professor +of nuclear science + +and engineering. + +Has produced a number +of courses on OCW, + +including the build-your-own +Geiger counter short course, + +lots of inspiration out there. + +So I'd like to ask +each of our panelists + +to take, maybe, another +minute to introduce yourself + +a little more fully, +and in particular maybe + +if you can share a reflection +on what OCW has meant to you. + +And I'd like to +start off with Hal, + +and then we'll +move on to Mussie. + +OK Curt, thanks a lot. + +And, Krishna, thank you for +that wonderful introduction. + +Today is a wonderful +20th anniversary, + +but actually it's a +triple 20th anniversary. + +Because there are +three initiatives that + +are interlinked, that all +have to do with this notion + +of open sharing. + +OCW is, I think, the +most revolutionary. + +But there's also +Creative Commons, + +which says, how do we +align this idea of sharing + +with the technicalities +of US copyright law? + +And then there is DSpace +in the MIT libraries, which + +is how do we take that same +vision of sharing, not just MIT + +educational courses, but +MIT research publications? + +These all sit +together, they all join + +in supporting this idea of +open sharing of knowledge + +and what is the right-- + +what's the appropriate +stance for a great world + +leading university +to take, in terms + +of benefiting humanity through +its intellectual productions? + +These all build +on the internet + +as a vision of sharing. + +And it's worth noting, +we talk about vision. + +There were other +initiatives 20 years ago + +that had the same vision. + +Almost none of +them survive today. + +And so the three things +that we're talking about + +are all there, are +all productive, + +and are all improving humanity. + +We often talk about MIT +as a wonderful vision. + +The reality is that visions at +this place are a dime a dozen. + +What's important is +that you carry through, + +and you make something +that's actually + +implemented and sustainable. + +And when I think about what MIT +started 20 years ago, the fact + +that we're still here, +and still producing, + +unlike so many +other initiatives, + +is something that makes me +enormously proud of MIT. + +Thank you, Hal. + +Thank you for helping +us get that kicked off. + +Mussie. + +All right. + +Me and OCW, I kind of wish +I knew OCW much earlier. + +I'm originally from +Ethiopia, and there + +were times where, being in +kind of a low-resource area, + +the issue is not that +you don't want to learn. + +It's not that you don't want +to build your capabilities. + +But you really don't see the +pathways and the roads that + +will allow you to get there. + +So, for me, what +OCW really means is, + +it's an opportunity for me +to accomplish the things + +that I want. + +It's a pathway. + +And it's not just for me, +but it's for my brothers + +and sisters all over the world. + +Thank you. + +Thank you. + +Anjali. + +Great comments. + +I was thinking about my +own youth, now long ago. + +And I would read books +and get an escape + +to the rest of the +world, from the novels + +and non-fiction books I read. + +And now, there's OCW. + +You can walk through +another door, + +and find out all +kinds of information + +that's presented +in ways that allow + +you to make your own path +through at the pace that + +works for you as an +instructor or as a learner. + +I benefit a ton from +teaching with OCW in my mind, + +because it encourages +me to reflect, + +to be conscious about +what I'm teaching. + +I now write all my +syllabi, for instance, + +with links to +open-source content, + +so that others can benefit +from it and I can share freely. + +I love that it +mirrors our commitment + +to a physically open campus. + +I also have gone to +other universities + +where you have to always +unlock every door, + +and it's pretty cool +that MIT's so open. + +Not amid COVID, but +soon we will be again. + +And finally, when I launched +my global health work, + +I went to Kenya and +met all kinds of folks. + +I was just learning +about the discipline. + +And somebody I +met very early on, + +just randomly on +the street, said, + +I use a mirror site in Rwanda. + +Thank you, thank you MIT for +sharing all this material. + +We use it all the time. + +I didn't even know. + +I didn't even know there were +people all over the world who + +were feeling part of MIT. + +So that's pretty cool. + +Thank you Anjali. + +And Mike. + +Sure. + +Well, I'd like to say that +I'm not just a contributor, + +but I was also a client of OCW. + +I started at MIT in 2001 as a +first year, and for me it's-- + +I've watched OCW give back to +the world, and even to MIT, + +in so many more dimensions +than I could have imagined. + +As a first year, I was +an example-based learner. + +And OpenCourseWare gave me the examples + +I needed to survive MIT, because +without them, I'm not sure + +I would have been able to. + +I started off, grade-wise, kind +of at the bottom of the pack, + +and once I found and +used OCW, that changed. + +And now, as a +faculty member, I've + +got the opportunity to +travel all over the world, + +despite not moving an +inch, in the past 20 years. + +I've been able to travel +outwards, and look back + +inwards. + +And to echo something +that was said before, + +the number of people around +the world that use and are + +thankful for OCW is incredible. + +I had an IAE mission +to the National University + +of Mongolia, and for +many of their courses + +their syllabus is the +OpenCourseWare syllabus. + +And to see ways that +not just students learn, + +and they feel amazing when +they conquer MIT problem + +sets of material, but how +instructors reinterpret + +our material gives +me inspiration + +to bring back, to make +the courses at MIT better. + +Thank you. + +I'm so glad that we're all +able to have this conversation + +together, and I'd like +to invite everybody who's + +watching this +session to please put + +your questions in the +chats, and in the places + +where you can enter questions, +and those will be fed back + +to us, and we'll definitely +spend a few minutes + +at the end of the +panel sharing thoughts + +on some of those questions. + +So I'd like to return +and ask each of you a bit + +of a follow up +question, if I could. + +Again, starting with Hal as +part of our founding team, what + +was in the water in 2001? + +What do you think led to +this flowering of openness + +at that time? + +What has it led to? + +So it's a little hard to +remember what 2001 was like. + +This was sort of the first +kind of explosion of enthusiasm + +around the internet. + +And Chuck Vest, president +of MIT at that time, + +would go around talking, and +alumni and other groups + +would say to him, +there's this internet. + +What's MIT going to do about it? + +And there was this +notion about, there's + +an enormous opportunity, but we +didn't really know what it was. + +And then there was a whole study +we took, first with McKinsey, + +and then with Booz Allen, trying +to come up with something. + +And this revolutionary idea, +that we should just open it up + +to the world, kind of emerged, +was extremely counterintuitive, + +because where universities were, +in those days by and large, + +was that their +courses were going + +to be enormous gold mines. + +That they were going to +sell to alumni and others, + +and we did a study +at MIT and said, + +well, know, that's not +really going to work for MIT. + +And then there was +this enormous insight, + +I think Dick Yue had it +when he was getting food out + +of the refrigerator +at night, that + +said, why don't we +just give it away? + +And the amazing thing is that +the MIT administration took it + +seriously. + +And really put MIT's +force behind it, + +and MIT's credibility behind it. + +And that's really +how it happened. + +As I mentioned before, many of +those other places, involving + +Stanford, and Princeton, +and Columbia, and all that, + +don't exist anymore. + +The one exception is eCornell. + +And we had this very, +very funny thing + +where MIT has been asked by some +of those organizations to join. + +Remember that person who was +running Fathom, which came out + +came out of Columbia, +came by to MIT, + +trying to get MIT to join +the commercial Fathom. + +And this was like +the day before we + +were going to announce +OpenCourseWare, + +and it was just +kind of funny, it + +was kind of + confidential, it was + +kind of funny, kind of sitting +there and saying, oh, yeah, + +well, you know, +about tomorrow, we're + +about to take all of this stuff, +and revolutionize and make it + +free. + +But it's a little hard to +appreciate the real fervent + +around the internet, and +I think we'll say later, + +when we talk about +the future, we're + +in the reflection of +that period today, + +and it's something we should +be thinking about very, very + +hard as we think about +the climate today, + +as compared to the +climate 20 years ago. + +Yeah, thank you. + +Yeah. + +Let's come back +to that, for sure. + +I'd like to ask Mussie, +as a beneficiary of some + +of that openness, what +would you like people + +to know about how open +education is affecting + +students' lives today? + +What did you experience, +and what do you + +see both at your community +college colleagues, + +and here at MIT? + +So before-- OER is the +solution to the problem + +of the cost of educational +resources becoming + +a barrier to education. + +And that happens at +different levels. + +There's the, I'm taking a +course, I want to know more, + +I want to get a more in-depth +knowledge, and I'm interested. + +That's one aspect that OCW +really tackles directly. + +You can just go to the website, +it's in an organized manner, + +which, in my +personal experience, + +the internet usually isn't. + +It's just like, hey, here's +bits and pieces of everything. + +The other aspect of it +is, in order for classes + +to get accreditation and so on, +professors in these community + +colleges are almost forced +to have these textbooks + +that larger organizations can-- + +the larger institutions, +educational institutions, use. + +So what, by MIT producing +open educational resources + +like this, basically +what it's saying is, + +it's putting its big name, +its big powerful name, + +behind open educational +resources, which really gives + +freedom back to instructors +in these community colleges + +to kind of say, hey, +there's this textbook, + +but MIT has kind +of validated this, + +and we can kind of approach it. + +So, for me and my friends and +all, the basic point is this. + +We're trying to +get an education. + +And OCW is just an easier way. + +It just removes certain +cost-based barriers. + +Yeah. + +That cost foundation has +become such a core issue + +in the open education +resources movement. + +We hear that, Mussie, a lot. + +Anjali, in your experience +trying to work globally, + +I'm curious how you see +open knowledge sharing + +playing out and helping people +build, achieve, solutions + +more rapidly, more +effectively, and to what extent + +is the free-ness and +the openness of it + +making that happen? + +So almost 15 years +ago, when I started + +working in global +health, I realized + +this is a domain in which we +are, by definition, neophytes. + +MIT doesn't have a +medical school or school + +of public health. + +So I already had to collaborate +in order to just get the course + +going, I set up collaborations +with Harvard Medical + +School, clinicians all over +the world that I could find, + +who would serve as guides, +as partners, help me source + +and develop projects. + +But the minute I +started doing that, I + +realized I need to share. + +So I am relying on others to +share with me, I need to share. + +So there was a really +nice fit with OCW, + +It's interesting, because you +think of online, I don't know, + +short videos being very kind +of procedural or instructional, + +but OCW can handle a +lot of complexity, too. + +And I've really been +wrestling over these years + +with how best to present +and frame that complexity. + +So I guess there's two +themes in my answer. + +One is I think we all +rely on many others + +to fuel our learning, and +being conscious of that + +when you share what +you've developed + +is, I think, just a really +good way to keep you + +honest about the +role of expertise + +from all over the place. + +And it also allows me to honor +everybody's contributions, + +because I can record +and share in OCW. + +And third, by kind of +archiving and building + +on work year-to-year, +it's really good for me + +as an instructor, for my +students over the years, + +to be able to see, how +has our thinking evolved? + +And I'll say to students, we're +going to be archiving this. + +And we put student work up. + +So we disguise it, we +get their permission, + +we remove any proprietary +or confidential information, + +but because we +share every year, we + +can generate an +amazing dialogue, + +not only with potential +students like Mussie, + +but also with alums and +with potential partners. + +We get to show our work +in a new way, which + +I think is really cool. + +Yeah. + +Yeah. + +I think this theme of opening +up the sharing of knowledge, + +the access to knowledge, +across all forms of expertise + +is so powerful. + +I'd like to ask Mike, +maybe, to start off. + +Having been a student +at MIT, and watched how + +this institute has evolved. + +What do you think about the way +that students are contributing + +to this knowledge, and +colleagues around the world + +are contributing to this +knowledge, all together mixed + +up with what the MIT +faculty are teaching? + +What does that indicate +to us about the power + +of this movement? + +Sure, I'd be happy +to answer that. + +So in terms of how does the +mere presence of OpenCourseWare + +enable students, and colleagues, +and other instructors + +from around the +world to contribute, + +just the very fact +that it exists + +in this purely open and +free environment, like Hal + +so well said, is +the deciding factor + +that just allows humanity +to share its knowledge. + +This, to me, is the single +best thing in education. + +It's the largest thing I know of +just free knowledge access to the world. + +And so, in every interaction +I have, from the emails + +I'm getting during the +pandemic of people saying, + +I've watched all your +lectures and they've + +kept me going and +intellectually stimulated, + +to hearing how other faculty at +the schools around the country + +and around the world have said, +hey, I took your lectures, + +and we added these +other new labs. + +Bring them back to MIT. + +This, the whole +idea of open sharing + +is infectious in the +best possible way. + +And once you get hooked, +it's hard to stop, + +which also gets at +one of the questions I + +saw on the chat, which is, +how do you convince faculty + +to participate? + +I think by participating. + +It's the single +biggest factor to me, + +as somebody who has both +benefited from and contributed + +to OCW, it's altruism. + +It's the desire for your, +what you learned + +and what you can teach to +impact humanity for the better. + +That's, to me, the whole +reason I get up in the morning, + +and I think that's the case +for most people in the world, + +they want to do good. + +They want to see +themselves do good. + +And OpenCourseWare provides +this enormous attractive force + +for everyone to see +a part of themselves + +in this rapidly +evolving and improving + +open educational space. + +Yeah. + +Yeah. + +Thanks. + +It's great to see that some +of the questions coming in, + +I'd like to encourage +people, again, + +to keep those questions coming. + +I think that question +of, what would you + +say to folks who are a little +unsure about participating + +in open sharing, they may +have some hesitations. + +I'd like to open that up to +the whole panel for a moment + +and invite other +reflections on that. + +Mussie, Anjali-- + +So, I would say that +the act of sharing + +gets you to be +reflective in a way + +that I think can serve your +goals as an instructor, + +and a teacher. + +So that's one reason to share. + +And the other is, to Mike's +point, it is pretty addictive. + +I keep coming up with new +ideas of things to share. + +Like, little +experiments I've tried. + +Let's put that up, +let's share that. + +Or reflections I have. + +I love the educator +version of courses + +that allows you, +as the instructor, + +to have a kind of sidebar +conversation with the audience, + +and talk through +your experience, + +and your philosophy. + +I think that's a +pretty cool feature. + +And OCW has not been +afraid to do all kinds + +of different experiments. + +So I had students +a few years ago + +who were from +Spanish-speaking countries + +and Portuguese-speaking +countries. + +We tried getting-- they recorded +their experience in English, + +but also in their +native languages. + +And that was pretty cool. + +We just gave that a shot. + +OCW was totally +willing to do it. + +And we didn't actually have +that capability hard-baked + +into the OCW +platform at the time, + +but that didn't stop you guys +from helping to figure it out. + +It's fun, figuring those +things out together. + +Yeah. + +Mussie? + +Yeah. + +So I kind of want to +answer this in two ways. + +The first is, to +a certain extent, + +it's really about +vulnerability, isn't it? + +You're putting all your +content out as an institution. + +You're kind of saying, +this is what I do. + +And you'll get feedback, +whether you like it or not. + +But that vulnerability +comes with a grain of, + +you can learn. + +You, as the +institution, can learn + +how to do what you're +supposed to be doing better. + +And the other part +of it is, and I + +think for a lot of +institutions, it's + +the fear of, well, the +value that students + +pay for will be open for free. + +And for institutions, +that fear that, I really + +want to pose the question +of, is that your only value? + +Is the content your only value? + +And if it is, there's a +world of content coming. + +Don't be Blockbuster when +Netflix came up and not adapt. + +Find and create value, +in education still, + +but find a way that's +not just only content, + +and ride the wave, +as opposed to-- + +Yeah. + +Good. + +Great. + +So I think there are enormous +opportunities for MIT, + +and as Mussie just +mentioned, you know, + +what's really MIT's value? + +It's not a kid sitting +down watching television. + +But I wanted to make +a more general point, + +that when we openly share +things, for anyone, not just + +MIT, we're enriching +the fount that's + +the source of our creativity. + +When we started MIT, when +we started OpenCourseWare, + +Chuck Vest wrote a +nice little piece + +of about that where he said, he +thought the image of students + +all over the world sitting and +all looking at presentations + +by the top faculty in the +world, that, for him, he said, + +was one of his +recurring nightmares. + +That's not what +OpenCourseWare is about. + +OpenCourseWare is enriching +the basis by which we all + +do creativity, not just a couple +of top classes, but everyone. + +I wanted to +introduce a word that + +comes from Jonathan Zittrain +at Harvard Law School called + +A Generative Platform. + +A generative platform +is where there are many, + +many, many people openly +collaborating and creating + +new things, +including things that + +were not anticipated +by the people who + +created the platform. + +So what I'm hoping, +and OpenCourseWare + +is doing so well, is really +being generative in that way. + +Because it's not that +MIT and five other places + +can make a vision of +education for all of humanity, + +it's that we can enable other +people to build on our work. + +Yeah Yeah. + +I'd love to use that +as a springboard + +into a reflection +on what we'd like + +to see from the future of OCW. + +If you can project 20 years out, +that's great, but I'll take 5. + +Where do you think we can go +with this generative potential? + +Maybe start with Mussie? + +So, I've had the opportunity +to be a user, and come to MIT + +and kind of see that +increase in value. + +And, again, I would +love if OCW drove that. + +So what I mean by +that is collaboration. + +A huge part of my MIT +experience has been the fact + +that I can work on +problems with people. + +I can see how they think, +they can see how I think, + +and we end up thinking better. + +So seeing OCW become a +platform for everyone + +in the world to kind +of come together. + +For people that +don't necessarily + +know each other to go on a +path of education together, + +I think, would be a huge help. + +Especially because +me, as a user, + +it was somewhat +difficult doing it alone. + +It's easy to kind of +fall off the wagon. + +Another vision of OCW I +have is that we, again, + +lead this movement of open +educational resources. + +And that goes back to my +very first point of we + +put our name behind it, and +we pull other institutions + +with us. + +We bring them in and we +sell them on the idea + +that if we open this +up, there is real value + +to be created for the whole. + +I like it. + +Yeah, and you sort of answered +a question we had from Mustaffa + +about getting students +to meet around the world, + +is there some way to +use OCW in that spirit? + +Yeah, we see great +potential in that. + +It's an area that we've +experimented with, + +off and on, over the years. + +Continue to be +working on, and yeah. + +I hope to see more take shape. + +Let's see, Anjali, +thoughts for the future? + +So I have many +conflicting thoughts. + +I'll just share a couple. + +I love the idea of +meetups of some kind. + +I think that a +recommendation engine + +of some kind, or a linkage +engine of some kind + +would be really interesting. + +And maybe not just a very +predictable, like, now that + +you've taken Linear Algebra I +take Linear Algebra II, + +but something that kind +of pushes us a little bit. + +And we know that +people are looking + +at using expert +systems and other methods + +to pull out content +from learners + +to figure out what they +need to learn next. + +I do like that idea. + +I also think we've +seen a huge growth + +in open educational materials, +and teaching management, + +I mean really, some +of it is not great. + +So I think we also need to +think about the quality piece. + +Do we just assume, because +it comes out of MIT, + +it's all great? + +What's our method for +figuring out and validating + +excellent content? + +If you teach a course at +MIT, you know it's good, + +but there may be ways in which-- + +maybe by stitching together +more meta information, + +we could round out +the picture more. + +So if you take a class +on, I don't know, + +financial models for +something, maybe you also + +learn about poverty, +or something. + +Something that kind of +rounds it out a little, + +so that we're getting +well-rounded views. + +I think we've sparked a +revolution in open education. + +I saw that a lot with medical +information, for instance. + +I think there's a lot +more work to be done. + +So I'm really excited +for the next chapter. + +Yeah. + +Me too. + +Thank you. + +Mike, any reflections +on the future? + +Sure. + +I'd sum it up with three +words, which would be renewal, + +enrichment, and humanization. + +I'll start with renewal, which +I think is the easiest one. + +We've created this +amazing engine + +for getting content out there, +and we need to keep it current. + +And that's not just +going to involve + +getting the next piece that's +up there every five years, + +but convincing new faculty +to have new interpretations + +of the courses, so that +there'll be multiple teaching + +styles for each +one, and students + +can look through some of +the lectures and ideas, + +and find the one +that suits them best. + +I'd say enrichment, +because there + +are things that OpenCourseWare +is doing now that I + +think we need to do more of. + +For example, podcasts with +some of the instructors + +on their educational philosophy. + +On how they design +courses, how they + +get hands-on elements +into what could + +be dry and boring courses. + +That also feeds into +humanization of knowledge. + +To build on something +Mussie was saying, + +if there's no downside +to contributing to OCW, + +and the upsides are +enormous besides the ones + +that we've talked about here. + +To me, it's the humanization of +not just knowledge in general, + +but of these supposedly lofty +MIT faculty in particular. + +Those of us here know that +we all make mistakes, and say + +stupid things, and the power +structure here is pretty flat, + +but I've come to +learn that's not + +how we're viewed +from the outside + +unless you already know us. + +And I think it's important +to be on YouTube, making + +occasional mistakes, +which I certainly + +did in my 22.01 Intro to +Nuclear Physics lectures. + +I had a couple of goofs on +the length of the control rods + +from Chernobyl, which +you might imagine + +is a pretty popular +topic to watch + +because of the TV +series going on now, + +and that's not a downside. + +There's an upside to be able +to crowdsource corrections, + +and project your own +humanity in the fact + +that, yeah, we're at MIT +but we make mistakes too, + +you can watch us do +it for all eternity. + +It doesn't scare me. + +To me, it's a bonus. + +Great. + +Yeah. + +Love that spirit. + +Hal, there's a question +in the chat that + +maybe sort of pertains to +one aspect of projecting + +the future, how you +had raised the three + +things at the beginning. + +Somebody has asked about +the future of open research + +and how, maybe, that +connects and supports + +the mission of OCW. + +If you care to respond +to that, or anything + +else about the future. + +Yeah, well, the future +is hard to predict. + +You talked about 20 +years, or 5 years. + +I would actually be happy, +now, with about 6 months. + +Because what's happening now +is, this is like 20 years ago, + +where there is this enormous +sense of possibility + +coming from the internet. + +And OpenCourseWare latched into +that, and when we look back, + +we're all delighted +with how that worked out + +and we say that what we did +then was counterintuitive, + +but it was right +and kind of obvious. + +But the world is changing. + +This is like 20 years +ago, but vastly different. + +When we thought +about OpenCourseWare, + +we thought about +new opportunities, + +we thought about changes, we +thought about what happened + +but what we didn't +think about is + +enormous change in +the very structure + +of tertiary education. + +And that's what we're +talking about now. + +You know, especially +accelerated by COVID, + +but coming before that. + +So I talked-- + +I mentioned a little bit about +how the founders of Columbia + +Fathom came to us and +in 2000, 2001, and said, + +you know, why don't you join +us, and we were going down + +this path of openness. + +I'll tell you another story. + +In 2012, the founders +of Coursera came to us + +and said, Stanford is +about to create Coursera, + +and would MIT like to partner +in making this tremendous thing + +about online courses? + +And we sort of said, +well, you know, + +they're thinking about a closed, +proprietary architecture, + +and not a thing that +people can contribute to. + +And at MIT, we sort +of said, well, no. + +OK. + +Last week, Coursera had its +IPO, it went up 45% at IPO, + +and it's valued now +at about $60 billion. + +That's something to think about. + +Are we still thinking +about openness? + +Are we still thinking +about the importance + +of generative platforms to +the extent that we were then? + +This is a real challenge. + +And it's really something +that we need to think about. + +And it is not obvious. + +So while we're celebrating +having made, certainly, + +the right choice 20 years ago, +what does that mean for today? + +I think we all need to think +about that very seriously. + +Thank you. + +Yeah, looking +forward to continuing + +to work with you +and everybody else + +around our community +on that one. + +Yeah, so thank you all for +a really great discussion. + +And I appreciate all the +points that you've raised. + +Lots more to keep talking about. + +In the last few +minutes, we're going + +to project forward into +our future in a more + +kind of concrete way, and +talk about the next generation + +OCW. + +And I'd like to welcome +my colleague Krishna back + +into the call to start sharing +some reflections and more + +information about the +next generation of OCW. + +Thank you very much, Curt. + +And thank you Hal, +Mussie, Anjali, and Mike + +for that great discussion. + +I, actually, I can't resist. + +I'll say to Hal the singular +moment in 2001 that you + +described is real and +critical, but I also + +think that in another way, what +you and others did back then + +flowed from 100 years +of history at MIT, + +and a sense of our +values and principles. + +And if you go back to +the very founding of MIT, + +President William Barton +Rogers, who founded MIT, + +thought he had a great way to +teach that was new at the time. + +This is in the 1870s. + +And he rode by train up +and down the East Coast, + +spreading his way of +teaching to places like Yale, + +and Princeton, and that place, +other place in Cambridge, + +Massachusetts. + +So this goes back to +the very beginning. + +Of course, the technological +means of sharing + +was completely different +in 2001 than in 1870. + +Curt, can you share your slide? + +I don't know if that has +already happened or not. + +So as we look to +the coming 20 years, + +as we celebrate +OCW's 20th birthday + +and look ahead to +its next 20 years, + +we are very excited +to be developing + +a next generation +platform and program + +that Curt and I are +going to tell you + +a little bit about now. + +And I want to emphasize, +platform and program. + +This is as much about +program as platform, + +although it's about both. + +Many of the things that I'll +say in the next few minutes + +actually come directly from +what was said by the panelists. + +One of our central +goals in thinking + +about the next generation +OCW platform and program, + +is to make sure +that we can offer + +the world a vibrant and +up-to-date sharing of the MIT + +curriculum, as it evolves. + +This is something +that Mike spoke about. + +Its content will +evolve as we at MIT + +address grand +challenges of today, + +like social justice, +and sustainability, + +and the future of computing. + +The means by which +we teach also evolve. + +It's our hope that going +into the future, as now, OCW + +will be the place that MIT +faculty can share openly + +the way that they +teach, how they teach, + +as well as what they teach. + +And that requires a new +platform in many, many senses. + +On the back end, it +requires a platform + +that will allow us to +update, and refresh, and keep + +vibrant hundreds and hundreds +of courses every year, + +which is something that +we're not able to do today, + +but we will be able +to do very soon. + +I'll also, for riff a minute +on Mussie, what Mussie said. + +What you come to MIT for, +which goes beyond the content + +that we can share through +OCW and many other means, + +is engagement. + +And what we want +to do with OCW is + +to give learners and +educators elsewhere, + +in their communities, +the ability + +to create their own magic, just +as MIT students and faculty + +create with the engagement +that they experience on campus. + +Engagement in so many +different senses. + +We hope that we empower that, +but the educators elsewhere + +who use these +materials to create + +the engagement +for their students + +are the key, actually, to that. + +Returning to the +platform side of it, + +the new platform which all of +you, Curt, is very exciting-- + +Curt is going to tell +you in a few minutes + +how you can get a sneak +peek, an early look, + +at our new platform, which +will offer a seamless discovery + +and learning experiences, +new modes of discovery, + +new modes of search, learning +experiences on mobile devices. + +Early look at this starting +today for all of you + +who are here. + +We anticipate launching this +new platform later this calendar + +year, and we look forward +to getting feedback from all + +of you, starting today in fact. + +Another aspect of +the new platform + +will be integrations with the +learning management systems + +that educational +institutions use, + +so that open content +from OCW can better + +flow into the +educational ecosystems + +of other institutions. + +Again, platform and program. + +And I already spoke +at the beginning + +about the importance of +collaborations across the OER + +ecosystem if we want to +build from access to equity. + +OCW has done a magnificent +job now for of offering access + +to the curriculum from MIT, +to the teaching from MIT, + +to the learning from MIT. + +I'll also mention that we +already have a podcast, + +it was mentioned by Mike. + +Chalk Radio is a podcast where +you can listen to MIT faculty + +as they tell you how +to use these materials + +in your teaching, because they +will describe how they use it + +in theirs. + +We have instructor insights, +but to really realize + +a vision of equity, we +need learning pathways + +that are different +for different people, + +because different people come +from different starting points. + +And that means we +need the entire OER + +ecosystem, a web of +institutions and entities + +across the ecosystem, +collaborating + +and working together to +realize this grand vision. + +That's a brief intro to this +vision behind NextGen OCW. + +Curt now it's going to +give you a sneak peek. + +Thanks Krishna. + +And I'd like to +invite people to drop + +your thoughts in the +chat of whatever you're + +using to watch this event. + +What would you wish for +from the future of OCW? + +We'd love to hear from you. + +Now, it is my great +pleasure to introduce to you + +the current working, +very early draft + +version of the next +generation OCW website. + +And as Krishna said, we're going +to invite people to join us + +in this process of working +with it, experimenting with it, + +and giving us your feedback. + +So this is the site, and +links should be going out + +in the chats of your streams +for how you can sign up to be + +a beta tester on this site. + +We are those 2,500 +courses to the site, + +and they're all up +here in various forms. + +And we're keeping up with +the latest hot topics + +out in the world. + +Let's take blockchain +for instance. + +Our blockchain course, taught +by Professor Gary Gensler + +is on here. + +And you can explore it not +only on the current regular + +ocw.mit.edu website, +but here on NextGen, + +and explore, for instance, the +very popular video lectures. + +They are all here for you to +watch and keep checking out. + +There's, again, all the courses +from across the collection + +that you'll find here. + +Courses, for instance, World +Water Day was last week, + +you want to learn about +the intersection of water + +and climate change. + +We've got great courses on +topics like this as well. + +What I'm showing you here is +kind of the laptop, or computer + +version. + +We're really excited that the +next generation platform will + +be able to work well on mobile, +and so I just shrink down + +the size of the window here, you +can see how the template adapts + +and you can continue +to work effectively + +on your mobile phone, +because we know, + +for many people around +the world, their phone, + +their smartphone is the device. + +And so giving people a really +good experience on the phone + +is an essential part of +what we're setting up + +to do with Next Generation. + +So, again, you have +an opportunity. + +We invite you to join +us in testing out + +this next generation platform +as it evolves through the summer + +and into the fall. + +And we're really excited +about what the future brings. + +Many of the things +that have been talked + +about in the panel, and +people have been asking about, + +we are actively working on. + +Anjali mentioned better +ways to discover content. + +We're exploring with bringing +the latest techniques + +in machine learning, and so on, +to make our search interface + +work better. + +Better ways for people to find +and collaborate with each other + +when they are users of OCW. + +Language translations. + +Continuing to run the podcast, +the Chalk Radio podcast. + +All of these things +will be continuing. + +So do, please do reach out to us-- + +If I can just jump in and just +say to everyone, first of all, + +thank you in advance +for all your feedback. + +But second of all, I +hope you're starting + +to see how we can respond +to some of the challenges + +from the questions +from the audience. + +In fact, one of you asked, +how do we motivate faculty + +to participate? + +I actually think, I think +what we, inside of MIT, + +will have the opposite problem. + +As we launch this NextGen +platform and program, + +we're going to have to +handle a flood of faculty who + +want to participate. + +And not only the +flood of faculty + +want to participate, but +actually the students of MIT. + +Mussie is a tremendous +example, but we + +are hearing from other +students how they, too, + +want to participate +in contributing + +to OCW, and in prompting +faculty to contribute. + +So we look forward +to taking advantage + +of this next platform, this +NextGen platform and program, + +to handle a flood of +interest, and this, I think, + +really does flow from +what everyone-- what's + +not to like about +sharing on OCW, + +given what you've heard +from Anjali and Mike? + +And Hal? We have to be +ready for a 1,000 faculty who + +want to do so, and we look +forward to this challenge. + +Well put. + +Yeah. + +The future is very +bright, thank you. + +Thank you, Krishna. + +So, we're so glad that +you joined us today + +to celebrate this +auspicious 20th anniversary, + +and look forward with +us into the future. + +We really value your +continued support, + +whether that's sharing +OCW with your networks, + +using it in whatever +learning capacity + +that you would like to. + +Please do join us, +if you're willing, + +as a beta tester for the +emergent next generation OCW + +site, and in any other +ways that you can see. + +We love to hear from you. + +Please sign up at our +monthly newsletter + +to stay on top of it. + +Follow us on all the +social media channels. + +And we very much look forward +to continuing to support you + +in your learning journeys. + +Yeah. + +Thank you so much. \ No newline at end of file diff --git a/8kM9quINTHI.txt b/8kM9quINTHI.txt new file mode 100644 index 0000000000000000000000000000000000000000..ecb715fee934a643c6ab9f1d95735fde422465a6 --- /dev/null +++ b/8kM9quINTHI.txt @@ -0,0 +1,5739 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT OpenCourseWare continue to + + align:start position:0% +will help MIT OpenCourseWare continue to + + + align:start position:0% +will help MIT OpenCourseWare continue to +offer high quality educational resources + + align:start position:0% +offer high quality educational resources + + + align:start position:0% +offer high quality educational resources +for free + + align:start position:0% +for free + + + align:start position:0% +for free +to make a donation or to view additional + + align:start position:0% +to make a donation or to view additional + + + align:start position:0% +to make a donation or to view additional +materials from hundreds of MIT courses + + align:start position:0% +materials from hundreds of MIT courses + + + align:start position:0% +materials from hundreds of MIT courses +visit MIT opencourseware at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +okay so we're now starting to get into + + align:start position:0% +okay so we're now starting to get into + + + align:start position:0% +okay so we're now starting to get into +really familiar territory which is the + + align:start position:0% +really familiar territory which is the + + + align:start position:0% +really familiar territory which is the +hydrogen atom and it's a short step from + + align:start position:0% +hydrogen atom and it's a short step from + + + align:start position:0% +hydrogen atom and it's a short step from +hydrogen atom to molecules and we're + + align:start position:0% +hydrogen atom to molecules and we're + + + align:start position:0% +hydrogen atom to molecules and we're +chemists we make molecules and so but + + align:start position:0% +chemists we make molecules and so but + + + align:start position:0% +chemists we make molecules and so but +one question would that would be a + + align:start position:0% +one question would that would be a + + + align:start position:0% +one question would that would be a +legitimate question to ask is what is + + align:start position:0% +legitimate question to ask is what is + + + align:start position:0% +legitimate question to ask is what is +the hydrogen atom have to do with + + align:start position:0% +the hydrogen atom have to do with + + + align:start position:0% +the hydrogen atom have to do with +molecules because it's an atom and it's + + align:start position:0% +molecules because it's an atom and it's + + + align:start position:0% +molecules because it's an atom and it's +a simplest atom and and what I hope to + + align:start position:0% +a simplest atom and and what I hope to + + + align:start position:0% +a simplest atom and and what I hope to +show is that what we learn from looking + + align:start position:0% +show is that what we learn from looking + + + align:start position:0% +show is that what we learn from looking +at the hydrogen atom has all sorts of + + align:start position:0% +at the hydrogen atom has all sorts of + + + align:start position:0% +at the hydrogen atom has all sorts of +good non textbook stuff that prepares + + align:start position:0% +good non textbook stuff that prepares + + + align:start position:0% +good non textbook stuff that prepares +you for understanding stuff in molecules + + align:start position:0% +you for understanding stuff in molecules + + + align:start position:0% +you for understanding stuff in molecules +and I am going to stress that because + + align:start position:0% +and I am going to stress that because + + + align:start position:0% +and I am going to stress that because +you're not going to see any macquarie + + align:start position:0% +you're not going to see any macquarie + + + align:start position:0% +you're not going to see any macquarie +and you've probably never seen it + + align:start position:0% +and you've probably never seen it + + + align:start position:0% +and you've probably never seen it +elsewhere except in freshman chemistry + + align:start position:0% +elsewhere except in freshman chemistry + + + align:start position:0% +elsewhere except in freshman chemistry +when they expect that you understand the + + align:start position:0% +when they expect that you understand the + + + align:start position:0% +when they expect that you understand the +periodic table based on some simple + + align:start position:0% +periodic table based on some simple + + + align:start position:0% +periodic table based on some simple +concepts and they come from the hydrogen + + align:start position:0% +concepts and they come from the hydrogen + + + align:start position:0% +concepts and they come from the hydrogen +atom and and so I've learned it attempt + + align:start position:0% +atom and and so I've learned it attempt + + + align:start position:0% +atom and and so I've learned it attempt +to make those connections my last + + align:start position:0% +to make those connections my last + + + align:start position:0% +to make those connections my last +lecture was I told you something we're + + align:start position:0% +lecture was I told you something we're + + + align:start position:0% +lecture was I told you something we're +not you're not going to be tested on but + + align:start position:0% +not you're not going to be tested on but + + + align:start position:0% +not you're not going to be tested on but +it's about spectroscopy that's how we + + align:start position:0% +it's about spectroscopy that's how we + + + align:start position:0% +it's about spectroscopy that's how we +learn almost everything we know about + + align:start position:0% +learn almost everything we know about + + + align:start position:0% +learn almost everything we know about +small molecules and a lot of stuff about + + align:start position:0% +small molecules and a lot of stuff about + + + align:start position:0% +small molecules and a lot of stuff about +big molecules - the crucial + + align:start position:0% +big molecules - the crucial + + + align:start position:0% +big molecules - the crucial +approximations in that were that the + + align:start position:0% +approximations in that were that the + + + align:start position:0% +approximations in that were that the +dipole approximation where the radiation + + align:start position:0% +dipole approximation where the radiation + + + align:start position:0% +dipole approximation where the radiation +field is such that the molecule fields a + + align:start position:0% +field is such that the molecule fields a + + + align:start position:0% +field is such that the molecule fields a +uniform but oscillating electromagnetic + + align:start position:0% +uniform but oscillating electromagnetic + + + align:start position:0% +uniform but oscillating electromagnetic +field in developing the theory that I + + align:start position:0% +field in developing the theory that I + + + align:start position:0% +field in developing the theory that I +presented we assumed that only one of + + align:start position:0% +presented we assumed that only one of + + + align:start position:0% +presented we assumed that only one of +the initial eigenstates is populated at + + align:start position:0% +the initial eigenstates is populated at + + + align:start position:0% +the initial eigenstates is populated at +T equals zero and only one final + + align:start position:0% +T equals zero and only one final + + + align:start position:0% +T equals zero and only one final +eigenstate gets tickled and so that it + + align:start position:0% +eigenstate gets tickled and so that it + + + align:start position:0% +eigenstate gets tickled and so that it +gets populated + + align:start position:0% +gets populated + + + align:start position:0% +gets populated +and so that even though there's an + + align:start position:0% +and so that even though there's an + + + align:start position:0% +and so that even though there's an +infinity of states the the theory's + + align:start position:0% +infinity of states the the theory's + + + align:start position:0% +infinity of states the the theory's +specifies we start with one definite one + + align:start position:0% +specifies we start with one definite one + + + align:start position:0% +specifies we start with one definite one +and only one final state gets selected + + align:start position:0% +and only one final state gets selected + + + align:start position:0% +and only one final state gets selected +because of resonance and this is what we + + align:start position:0% +because of resonance and this is what we + + + align:start position:0% +because of resonance and this is what we +do all the time we we have an infinite + + align:start position:0% +do all the time we we have an infinite + + + align:start position:0% +do all the time we we have an infinite +dimension problem and we we discover + + align:start position:0% +dimension problem and we we discover + + + align:start position:0% +dimension problem and we we discover +that we only really need to worry about + + align:start position:0% +that we only really need to worry about + + + align:start position:0% +that we only really need to worry about +a very small number of states and and + + align:start position:0% +a very small number of states and and + + + align:start position:0% +a very small number of states and and +then we deal with that there are a + + align:start position:0% +then we deal with that there are a + + + align:start position:0% +then we deal with that there are a +couple of other assumptions that were + + align:start position:0% +couple of other assumptions that were + + + align:start position:0% +couple of other assumptions that were +essential for this first step into a + + align:start position:0% +essential for this first step into a + + + align:start position:0% +essential for this first step into a +Hamiltonian and that is the field is + + align:start position:0% +Hamiltonian and that is the field is + + + align:start position:0% +Hamiltonian and that is the field is +weak and so you get linear response that + + align:start position:0% +weak and so you get linear response that + + + align:start position:0% +weak and so you get linear response that +means that the increase in the mixing + + align:start position:0% +means that the increase in the mixing + + + align:start position:0% +means that the increase in the mixing +coefficient for the final state is + + align:start position:0% +coefficient for the final state is + + + align:start position:0% +coefficient for the final state is +proportional to the coupling matrix + + align:start position:0% +proportional to the coupling matrix + + + align:start position:0% +proportional to the coupling matrix +element times time now mixing + + align:start position:0% +element times time now mixing + + + align:start position:0% +element times time now mixing +coefficients can't get larger than one + + align:start position:0% +coefficients can't get larger than one + + + align:start position:0% +coefficients can't get larger than one +and so clearly we can't use a simple + + align:start position:0% +and so clearly we can't use a simple + + + align:start position:0% +and so clearly we can't use a simple +theory without saying ok we don't care + + align:start position:0% +theory without saying ok we don't care + + + align:start position:0% +theory without saying ok we don't care +about the mixing coefficients we care + + align:start position:0% +about the mixing coefficients we care + + + align:start position:0% +about the mixing coefficients we care +about the rate of increase and so by + + align:start position:0% +about the rate of increase and so by + + + align:start position:0% +about the rate of increase and so by +going from amplitudes to rates we are + + align:start position:0% +going from amplitudes to rates we are + + + align:start position:0% +going from amplitudes to rates we are +able to have a theory that's generally + + align:start position:0% +able to have a theory that's generally + + + align:start position:0% +able to have a theory that's generally +applicable now what I did was to talk + + align:start position:0% +applicable now what I did was to talk + + + align:start position:0% +applicable now what I did was to talk +about a CW radiation field continuous + + align:start position:0% +about a CW radiation field continuous + + + align:start position:0% +about a CW radiation field continuous +many experiments use pulsed fields many + + align:start position:0% +many experiments use pulsed fields many + + + align:start position:0% +many experiments use pulsed fields many +experiments use an extremely strong + + align:start position:0% +experiments use an extremely strong + + + align:start position:0% +experiments use an extremely strong +pulsed field that I hope to revisit + + align:start position:0% +pulsed field that I hope to revisit + + + align:start position:0% +pulsed field that I hope to revisit +later in the course but the CW problem + + align:start position:0% +later in the course but the CW problem + + + align:start position:0% +later in the course but the CW problem +is the best way to begin ok so now let's + + align:start position:0% +is the best way to begin ok so now let's + + + align:start position:0% +is the best way to begin ok so now let's +talk about that regime + + align:start position:0% + + + + align:start position:0% + +we did the rigid rotor and that led to + + align:start position:0% +we did the rigid rotor and that led to + + + align:start position:0% +we did the rigid rotor and that led to +some angular momenta well it's just a + + align:start position:0% +some angular momenta well it's just a + + + align:start position:0% +some angular momenta well it's just a +picture so we have this rigid rotor and + + align:start position:0% +picture so we have this rigid rotor and + + + align:start position:0% +picture so we have this rigid rotor and +it's rotating about the center mass and + + align:start position:0% +it's rotating about the center mass and + + + align:start position:0% +it's rotating about the center mass and +the Schrodinger equation tells us the + + align:start position:0% +the Schrodinger equation tells us the + + + align:start position:0% +the Schrodinger equation tells us the +probability amplitudes of the rotor axis + + align:start position:0% +probability amplitudes of the rotor axis + + + align:start position:0% +probability amplitudes of the rotor axis +relative to the laboratory frame and we + + align:start position:0% +relative to the laboratory frame and we + + + align:start position:0% +relative to the laboratory frame and we +got angular momenta which we can we can + + align:start position:0% +got angular momenta which we can we can + + + align:start position:0% +got angular momenta which we can we can +denote by little L Big L J and many + + align:start position:0% +denote by little L Big L J and many + + + align:start position:0% +denote by little L Big L J and many +other things and this is important + + align:start position:0% +other things and this is important + + + align:start position:0% +other things and this is important +because if it's an angular momentum you + + align:start position:0% +because if it's an angular momentum you + + + align:start position:0% +because if it's an angular momentum you +know it you know everything about it and + + align:start position:0% +know it you know everything about it and + + + align:start position:0% +know it you know everything about it and +you don't know yet that if you have two + + align:start position:0% +you don't know yet that if you have two + + + align:start position:0% +you don't know yet that if you have two +angular momenta you could know + + align:start position:0% +angular momenta you could know + + + align:start position:0% +angular momenta you could know +everything about the interactions + + align:start position:0% +everything about the interactions + + + align:start position:0% +everything about the interactions +between them that's called the Vigna + + align:start position:0% +between them that's called the Vigna + + + align:start position:0% +between them that's called the Vigna +record theorem that's not in this course + + align:start position:0% +record theorem that's not in this course + + + align:start position:0% +record theorem that's not in this course +but the important thing is if you got + + align:start position:0% +but the important thing is if you got + + + align:start position:0% +but the important thing is if you got +angular momenta you're on solid ground + + align:start position:0% +angular momenta you're on solid ground + + + align:start position:0% +angular momenta you're on solid ground +and you can do stuff that doesn't ever + + align:start position:0% +and you can do stuff that doesn't ever + + + align:start position:0% +and you can do stuff that doesn't ever +need to be repeated and so you know one + + align:start position:0% +need to be repeated and so you know one + + + align:start position:0% +need to be repeated and so you know one +of the things that we learned about the + + align:start position:0% +of the things that we learned about the + + + align:start position:0% +of the things that we learned about the +angular momenta was that we have now I'm + + align:start position:0% +angular momenta was that we have now I'm + + + align:start position:0% +angular momenta was that we have now I'm +going to switch even though it's it's + + align:start position:0% +going to switch even though it's it's + + + align:start position:0% +going to switch even though it's it's +going to be L as the angular momentum + + align:start position:0% +going to be L as the angular momentum + + + align:start position:0% +going to be L as the angular momentum +mostly in the hydrogen atom I'm going to + + align:start position:0% +mostly in the hydrogen atom I'm going to + + + align:start position:0% +mostly in the hydrogen atom I'm going to +straight switch to J which is my + + align:start position:0% +straight switch to J which is my + + + align:start position:0% +straight switch to J which is my +favorite notation so J squared operating + + align:start position:0% +favorite notation so J squared operating + + + align:start position:0% +favorite notation so J squared operating +on a state now I can denote it like this + + align:start position:0% +on a state now I can denote it like this + + + align:start position:0% +on a state now I can denote it like this +or I can let a denote it like this it's + + align:start position:0% +or I can let a denote it like this it's + + + align:start position:0% +or I can let a denote it like this it's +the same general idea these are not + + align:start position:0% +the same general idea these are not + + + align:start position:0% +the same general idea these are not +quite equivalent things but we'll and + + align:start position:0% +quite equivalent things but we'll and + + + align:start position:0% +quite equivalent things but we'll and +and you get H bar squared J plus 1 J m + + align:start position:0% +and you get H bar squared J plus 1 J m + + + align:start position:0% +and you get H bar squared J plus 1 J m +and we have JZ operating on J M you get + + align:start position:0% +and we have JZ operating on J M you get + + + align:start position:0% +and we have JZ operating on J M you get +H bar m JM and we can have J plus minus + + align:start position:0% +H bar m JM and we can have J plus minus + + + align:start position:0% +H bar m JM and we can have J plus minus +operating on J M and that's H bar and + + align:start position:0% +operating on J M and that's H bar and + + + align:start position:0% +operating on J M and that's H bar and +it's just more complicated looking thing + + align:start position:0% +it's just more complicated looking thing + + + align:start position:0% +it's just more complicated looking thing +j j plus 1 is M and plus or minus 1 so + + align:start position:0% +j j plus 1 is M and plus or minus 1 so + + + align:start position:0% +j j plus 1 is M and plus or minus 1 so +that's the only bit you have to remember + + align:start position:0% + + + + align:start position:0% + +and you might say well is it plus or + + align:start position:0% +and you might say well is it plus or + + + align:start position:0% +and you might say well is it plus or +minus 1 or minus or plus 1 and so if you + + align:start position:0% +minus 1 or minus or plus 1 and so if you + + + align:start position:0% +minus 1 or minus or plus 1 and so if you +choose M is equal to J then you know + + align:start position:0% +choose M is equal to J then you know + + + align:start position:0% +choose M is equal to J then you know +that if if you you have m is equal to J + + align:start position:0% +that if if you you have m is equal to J + + + align:start position:0% +that if if you you have m is equal to J +this is going to be 0 if we're doing + + align:start position:0% +this is going to be 0 if we're doing + + + align:start position:0% +this is going to be 0 if we're doing +raising operator and so there's nothing + + align:start position:0% +raising operator and so there's nothing + + + align:start position:0% +raising operator and so there's nothing +to remember if you are willing to go to + + align:start position:0% +to remember if you are willing to go to + + + align:start position:0% +to remember if you are willing to go to +an extreme situation and decide whether + + align:start position:0% +an extreme situation and decide whether + + + align:start position:0% +an extreme situation and decide whether +it's plus minus or minus or plus + + align:start position:0% + + + + align:start position:0% + +okay now the rigid rotor is a universal + + align:start position:0% +okay now the rigid rotor is a universal + + + align:start position:0% +okay now the rigid rotor is a universal +problem which is solved it deals with + + align:start position:0% +problem which is solved it deals with + + + align:start position:0% +problem which is solved it deals with +all central force problems everything + + align:start position:0% +all central force problems everything + + + align:start position:0% +all central force problems everything +that's round in the original donor is a + + align:start position:0% +that's round in the original donor is a + + + align:start position:0% +that's round in the original donor is a +fantastic starting point so one electron + + align:start position:0% +fantastic starting point so one electron + + + align:start position:0% +fantastic starting point so one electron +atoms for sure many electron atoms maybe + + align:start position:0% +atoms for sure many electron atoms maybe + + + align:start position:0% +atoms for sure many electron atoms maybe +will see and but anything that's round + + align:start position:0% +will see and but anything that's round + + + align:start position:0% +will see and but anything that's round +the rigid rotor is a good zero point for + + align:start position:0% +the rigid rotor is a good zero point for + + + align:start position:0% +the rigid rotor is a good zero point for +dealing with the angular part of the + + align:start position:0% +dealing with the angular part of the + + + align:start position:0% +dealing with the angular part of the +problem so for the hydrogen atom we have + + align:start position:0% +problem so for the hydrogen atom we have + + + align:start position:0% +problem so for the hydrogen atom we have +a potential it looks like this and so + + align:start position:0% +a potential it looks like this and so + + + align:start position:0% +a potential it looks like this and so +the radial potential is new if for the + + align:start position:0% +the radial potential is new if for the + + + align:start position:0% +the radial potential is new if for the +for the rigid rotor the radial potential + + align:start position:0% +for the rigid rotor the radial potential + + + align:start position:0% +for the rigid rotor the radial potential +was it's it's just 0 for the R is equal + + align:start position:0% +was it's it's just 0 for the R is equal + + + align:start position:0% +was it's it's just 0 for the R is equal +to R 0 and not 0 then the potential is + + align:start position:0% +to R 0 and not 0 then the potential is + + + align:start position:0% +to R 0 and not 0 then the potential is +infinite now here we have potential + + align:start position:0% +infinite now here we have potential + + + align:start position:0% +infinite now here we have potential +which doesn't go to infinity here and it + + align:start position:0% +which doesn't go to infinity here and it + + + align:start position:0% +which doesn't go to infinity here and it +does something strange + + align:start position:0% +does something strange + + + align:start position:0% +does something strange +because you can't get to negative R in + + align:start position:0% +because you can't get to negative R in + + + align:start position:0% +because you can't get to negative R in +spherical polar coordinates so this is + + align:start position:0% +spherical polar coordinates so this is + + + align:start position:0% +spherical polar coordinates so this is +is it a boundary condition or is it just + + align:start position:0% +is it a boundary condition or is it just + + + align:start position:0% +is it a boundary condition or is it just +an accident of the way we use + + align:start position:0% +an accident of the way we use + + + align:start position:0% +an accident of the way we use +coordinates okay so we're going to talk + + align:start position:0% +coordinates okay so we're going to talk + + + align:start position:0% +coordinates okay so we're going to talk +we're going to apply what we know about + + align:start position:0% +we're going to apply what we know about + + + align:start position:0% +we're going to apply what we know about +angular momenta to the hydrogen atom so + + align:start position:0% +angular momenta to the hydrogen atom so + + + align:start position:0% +angular momenta to the hydrogen atom so +our potential the hydrogen atom is going + + align:start position:0% +our potential the hydrogen atom is going + + + align:start position:0% +our potential the hydrogen atom is going +to be expressed in terms of the distance + + align:start position:0% +to be expressed in terms of the distance + + + align:start position:0% +to be expressed in terms of the distance +of the electron from the nucleus and + + align:start position:0% +of the electron from the nucleus and + + + align:start position:0% +of the electron from the nucleus and +then the Theta Phi coordinates which you + + align:start position:0% +then the Theta Phi coordinates which you + + + align:start position:0% +then the Theta Phi coordinates which you +already know and the theta phi part is + + align:start position:0% +already know and the theta phi part is + + + align:start position:0% +already know and the theta phi part is +universal and the r part is unique is + + align:start position:0% +universal and the r part is unique is + + + align:start position:0% +universal and the r part is unique is +special to each problem that as + + align:start position:0% +special to each problem that as + + + align:start position:0% +special to each problem that as +spherical symmetry and there are + + align:start position:0% +spherical symmetry and there are + + + align:start position:0% +spherical symmetry and there are +different kinds of approximations you + + align:start position:0% +different kinds of approximations you + + + align:start position:0% +different kinds of approximations you +use to be able to deal with them the + + align:start position:0% +use to be able to deal with them the + + + align:start position:0% +use to be able to deal with them the +nice thing about it is it's + + align:start position:0% +nice thing about it is it's + + + align:start position:0% +nice thing about it is it's +one-dimensional and we're very good at + + align:start position:0% +one-dimensional and we're very good at + + + align:start position:0% +one-dimensional and we're very good at +thinking about one-dimensional problems + + align:start position:0% +thinking about one-dimensional problems + + + align:start position:0% +thinking about one-dimensional problems +and even if the problem isn't exactly + + align:start position:0% +and even if the problem isn't exactly + + + align:start position:0% +and even if the problem isn't exactly +one-dimensional it has some hidden stuff + + align:start position:0% +one-dimensional it has some hidden stuff + + + align:start position:0% +one-dimensional it has some hidden stuff +to it we can we can extend what we know + + align:start position:0% +to it we can we can extend what we know + + + align:start position:0% +to it we can we can extend what we know +from one-dimensional problems and get a + + align:start position:0% +from one-dimensional problems and get a + + + align:start position:0% +from one-dimensional problems and get a +great deal of insight and if you have a + + align:start position:0% +great deal of insight and if you have a + + + align:start position:0% +great deal of insight and if you have a +one-dimensional problem it's very easy + + align:start position:0% +one-dimensional problem it's very easy + + + align:start position:0% +one-dimensional problem it's very easy +to describe the potential in one + + align:start position:0% +to describe the potential in one + + + align:start position:0% +to describe the potential in one +dimension and the eigenfunctions in one + + align:start position:0% +dimension and the eigenfunctions in one + + + align:start position:0% +dimension and the eigenfunctions in one +dimension and so we can begin to really + + align:start position:0% +dimension and so we can begin to really + + + align:start position:0% +dimension and so we can begin to really +understand everything ok so we're going + + align:start position:0% +understand everything ok so we're going + + + align:start position:0% +understand everything ok so we're going +to have a wave function which is going + + align:start position:0% +to have a wave function which is going + + + align:start position:0% +to have a wave function which is going +to have quantum numbers and we're going + + align:start position:0% +to have quantum numbers and we're going + + + align:start position:0% +to have quantum numbers and we're going +to be able to write it as a product of + + align:start position:0% +to be able to write it as a product of + + + align:start position:0% +to be able to write it as a product of +two parts well this is the same thing we + + align:start position:0% +two parts well this is the same thing we + + + align:start position:0% +two parts well this is the same thing we +had before for the rigid rotor so we're + + align:start position:0% +had before for the rigid rotor so we're + + + align:start position:0% +had before for the rigid rotor so we're +going to be able to take this order + + align:start position:0% +going to be able to take this order + + + align:start position:0% +going to be able to take this order +equation and separate the wave function + + align:start position:0% +equation and separate the wave function + + + align:start position:0% +equation and separate the wave function +into two parts a radial part and an + + align:start position:0% +into two parts a radial part and an + + + align:start position:0% +into two parts a radial part and an +angular part + + align:start position:0% +angular part + + + align:start position:0% +angular part +and this is old and this is new because + + align:start position:0% +and this is old and this is new because + + + align:start position:0% +and this is old and this is new because +we've got this we can use all of that + + align:start position:0% +we've got this we can use all of that + + + align:start position:0% +we've got this we can use all of that +stuff without taking a breath except + + align:start position:0% +stuff without taking a breath except + + + align:start position:0% +stuff without taking a breath except +maybe getting the right number letter L + + align:start position:0% +maybe getting the right number letter L + + + align:start position:0% +maybe getting the right number letter L +J s whatever so that's that's so really + + align:start position:0% +J s whatever so that's that's so really + + + align:start position:0% +J s whatever so that's that's so really +the hydrogen atom it's just one thing + + align:start position:0% +the hydrogen atom it's just one thing + + + align:start position:0% +the hydrogen atom it's just one thing +with some curveballs thrown at you in in + + align:start position:0% +with some curveballs thrown at you in in + + + align:start position:0% +with some curveballs thrown at you in in +the latter stages okay one of the things + + align:start position:0% +the latter stages okay one of the things + + + align:start position:0% +the latter stages okay one of the things +you also want to be able to do because + + align:start position:0% +you also want to be able to do because + + + align:start position:0% +you also want to be able to do because +nodes are so important in determining + + align:start position:0% +nodes are so important in determining + + + align:start position:0% +nodes are so important in determining +both the names of the states and how + + align:start position:0% +both the names of the states and how + + + align:start position:0% +both the names of the states and how +they perform how they behave in various + + align:start position:0% +they perform how they behave in various + + + align:start position:0% +they perform how they behave in various +situations including external fields in + + align:start position:0% + + + + align:start position:0% + +excitation by electromagnetic radiation + + align:start position:0% +excitation by electromagnetic radiation + + + align:start position:0% +excitation by electromagnetic radiation +you want to be able to understand the + + align:start position:0% +you want to be able to understand the + + + align:start position:0% +you want to be able to understand the +nodal surfaces and you already know this + + align:start position:0% +nodal surfaces and you already know this + + + align:start position:0% +nodal surfaces and you already know this +one so how many nodal surfaces are there + + align:start position:0% +one so how many nodal surfaces are there + + + align:start position:0% +one so how many nodal surfaces are there +if you have a particular value of L yes + + align:start position:0% +if you have a particular value of L yes + + + align:start position:0% +if you have a particular value of L yes +right and if you have a particular value + + align:start position:0% +right and if you have a particular value + + + align:start position:0% +right and if you have a particular value +of M how many nodes are there in the XY + + align:start position:0% +of M how many nodes are there in the XY + + + align:start position:0% +of M how many nodes are there in the XY +plane + + align:start position:0% + + + + align:start position:0% + +your hot probability density is oriented + + align:start position:0% +your hot probability density is oriented + + + align:start position:0% +your hot probability density is oriented +along Z + + align:start position:0% + + + + align:start position:0% + +okay now you're saying things that I + + align:start position:0% +okay now you're saying things that I + + + align:start position:0% +okay now you're saying things that I +have to stop and think about because + + align:start position:0% +have to stop and think about because + + + align:start position:0% +have to stop and think about because +you're not telling me what I expected to + + align:start position:0% +you're not telling me what I expected to + + + align:start position:0% +you're not telling me what I expected to +know so if M M is equal to zero L is + + align:start position:0% +know so if M M is equal to zero L is + + + align:start position:0% +know so if M M is equal to zero L is +perpendicular to the quantization axis + + align:start position:0% +perpendicular to the quantization axis + + + align:start position:0% +perpendicular to the quantization axis +and there are no nodes that that's true + + align:start position:0% +and there are no nodes that that's true + + + align:start position:0% +and there are no nodes that that's true +but that's the where the axis is is + + align:start position:0% +but that's the where the axis is is + + + align:start position:0% +but that's the where the axis is is +determined by theta and when you're when + + align:start position:0% +determined by theta and when you're when + + + align:start position:0% +determined by theta and when you're when +theta is equal to PI over two you're in + + align:start position:0% +theta is equal to PI over two you're in + + + align:start position:0% +theta is equal to PI over two you're in +the XY plane and depending and then the + + align:start position:0% +the XY plane and depending and then the + + + align:start position:0% +the XY plane and depending and then the +number of nodes in the XY plane is M or + + align:start position:0% +number of nodes in the XY plane is M or + + + align:start position:0% +number of nodes in the XY plane is M or +absolute value of M the Phi part of the + + align:start position:0% +absolute value of M the Phi part of the + + + align:start position:0% +absolute value of M the Phi part of the +rigid rotor is simple it's a + + align:start position:0% +rigid rotor is simple it's a + + + align:start position:0% +rigid rotor is simple it's a +differential equation that everybody can + + align:start position:0% +differential equation that everybody can + + + align:start position:0% +differential equation that everybody can +solve we already know that one and we + + align:start position:0% +solve we already know that one and we + + + align:start position:0% +solve we already know that one and we +know what the wave functions look like + + align:start position:0% +know what the wave functions look like + + + align:start position:0% +know what the wave functions look like +okay so we can write the equation and + + align:start position:0% +okay so we can write the equation and + + + align:start position:0% +okay so we can write the equation and +it's very quick to show separation of + + align:start position:0% +it's very quick to show separation of + + + align:start position:0% +it's very quick to show separation of +variables I'll do that in a minute and + + align:start position:0% +variables I'll do that in a minute and + + + align:start position:0% +variables I'll do that in a minute and +then we have the pictures of the + + align:start position:0% +then we have the pictures of the + + + align:start position:0% +then we have the pictures of the +separated parts yr NLM and essential in + + align:start position:0% +separated parts yr NLM and essential in + + + align:start position:0% +separated parts yr NLM and essential in +these pictures is the number of nodes + + align:start position:0% +these pictures is the number of nodes + + + align:start position:0% +these pictures is the number of nodes +and the spacing between nodes remember + + align:start position:0% +and the spacing between nodes remember + + + align:start position:0% +and the spacing between nodes remember +the semi-classical approximation we know + + align:start position:0% +the semi-classical approximation we know + + + align:start position:0% +the semi-classical approximation we know +that mr. Dubrow I really hit it out of + + align:start position:0% +that mr. Dubrow I really hit it out of + + + align:start position:0% +that mr. Dubrow I really hit it out of +the park by saying the the the wave + + align:start position:0% +the park by saying the the the wave + + + align:start position:0% +the park by saying the the the wave +length is H over P for + + align:start position:0% +length is H over P for + + + align:start position:0% +length is H over P for +one dimensional problem we know what to + + align:start position:0% +one dimensional problem we know what to + + + align:start position:0% +one dimensional problem we know what to +do with that and we're going to discover + + align:start position:0% +do with that and we're going to discover + + + align:start position:0% +do with that and we're going to discover +that for the radial problem we have a + + align:start position:0% +that for the radial problem we have a + + + align:start position:0% +that for the radial problem we have a +very simple way of determining what the + + align:start position:0% +very simple way of determining what the + + + align:start position:0% +very simple way of determining what the +classical momentum is and so we know + + align:start position:0% +classical momentum is and so we know + + + align:start position:0% +classical momentum is and so we know +everything about the nodes and the node + + align:start position:0% +everything about the nodes and the node + + + align:start position:0% +everything about the nodes and the node +spacing and the amplitudes between nodes + + align:start position:0% +spacing and the amplitudes between nodes + + + align:start position:0% +spacing and the amplitudes between nodes +and how to evaluate every integral of + + align:start position:0% +and how to evaluate every integral of + + + align:start position:0% +and how to evaluate every integral of +some power of R or Z and and so there's + + align:start position:0% +some power of R or Z and and so there's + + + align:start position:0% +some power of R or Z and and so there's +just an enormous amount gotten from the + + align:start position:0% +just an enormous amount gotten from the + + + align:start position:0% +just an enormous amount gotten from the +semi-classical picture once you are + + align:start position:0% +semi-classical picture once you are + + + align:start position:0% +semi-classical picture once you are +familiar with this okay and so we can we + + align:start position:0% +familiar with this okay and so we can we + + + align:start position:0% +familiar with this okay and so we can we +can say that we have the classical wave + + align:start position:0% +can say that we have the classical wave + + + align:start position:0% +can say that we have the classical wave +length or the semi-classical wave length + + align:start position:0% +length or the semi-classical wave length + + + align:start position:0% +length or the semi-classical wave length +it has an index R and so we have a + + align:start position:0% +it has an index R and so we have a + + + align:start position:0% +it has an index R and so we have a +momentum a linear momentum with a + + align:start position:0% +momentum a linear momentum with a + + + align:start position:0% +momentum a linear momentum with a +quantum number on it for L you see + + align:start position:0% +quantum number on it for L you see + + + align:start position:0% +quantum number on it for L you see +that's a little strange but that tells + + align:start position:0% +that's a little strange but that tells + + + align:start position:0% +that's a little strange but that tells +us what the potential is going to be and + + align:start position:0% +us what the potential is going to be and + + + align:start position:0% +us what the potential is going to be and +that tells us what to use in order to + + align:start position:0% +that tells us what to use in order to + + + align:start position:0% +that tells us what to use in order to +determine the wave length and this is + + align:start position:0% +determine the wave length and this is + + + align:start position:0% +determine the wave length and this is +really the core of how we can go way + + align:start position:0% +really the core of how we can go way + + + align:start position:0% +really the core of how we can go way +beyond textbooks we can do in our heads + + align:start position:0% +beyond textbooks we can do in our heads + + + align:start position:0% +beyond textbooks we can do in our heads +or on a simple piece of paper we can do + + align:start position:0% +or on a simple piece of paper we can do + + + align:start position:0% +or on a simple piece of paper we can do +this and we can draw we can draw + + align:start position:0% +this and we can draw we can draw + + + align:start position:0% +this and we can draw we can draw +pictures and we can evaluate matrix + + align:start position:0% +pictures and we can evaluate matrix + + + align:start position:0% +pictures and we can evaluate matrix +elements very without any complicated + + align:start position:0% +elements very without any complicated + + + align:start position:0% +elements very without any complicated +integral tables just you can you can + + align:start position:0% +integral tables just you can you can + + + align:start position:0% +integral tables just you can you can +make estimates that are incredibly + + align:start position:0% +make estimates that are incredibly + + + align:start position:0% +make estimates that are incredibly +important and from that you can get + + align:start position:0% + + + + align:start position:0% + +expectation values and also non off + + align:start position:0% +expectation values and also non off + + + align:start position:0% +expectation values and also non off +diagonal matrix elements of integer + + align:start position:0% +diagonal matrix elements of integer + + + align:start position:0% +diagonal matrix elements of integer +powers of the coordinate and that it's + + align:start position:0% +powers of the coordinate and that it's + + + align:start position:0% +powers of the coordinate and that it's +an enormous amount of stuff that you can + + align:start position:0% +an enormous amount of stuff that you can + + + align:start position:0% +an enormous amount of stuff that you can +do now you can't do it yet but after - + + align:start position:0% +do now you can't do it yet but after - + + + align:start position:0% +do now you can't do it yet but after - +after Wednesday's lecture you will and + + align:start position:0% +after Wednesday's lecture you will and + + + align:start position:0% +after Wednesday's lecture you will and +so this will be Wednesday this and then + + align:start position:0% +so this will be Wednesday this and then + + + align:start position:0% +so this will be Wednesday this and then +we'll have evidence + + align:start position:0% + + + + align:start position:0% + +electron spin and I will get to that + + align:start position:0% +electron spin and I will get to that + + + align:start position:0% +electron spin and I will get to that +today okay so this is the menu and now + + align:start position:0% +today okay so this is the menu and now + + + align:start position:0% +today okay so this is the menu and now +let's let's start delivering some of + + align:start position:0% +let's let's start delivering some of + + + align:start position:0% +let's let's start delivering some of +this stuff I have to write some big + + align:start position:0% +this stuff I have to write some big + + + align:start position:0% +this stuff I have to write some big +equations so the Hamiltonian is kinetic + + align:start position:0% +equations so the Hamiltonian is kinetic + + + align:start position:0% +equations so the Hamiltonian is kinetic +energy plus potential energy and the + + align:start position:0% +energy plus potential energy and the + + + align:start position:0% +energy plus potential energy and the +kinetic energy was I'm sorry for the for + + align:start position:0% +kinetic energy was I'm sorry for the for + + + align:start position:0% +kinetic energy was I'm sorry for the for +the rigid rotor V was zero right and + + align:start position:0% +the rigid rotor V was zero right and + + + align:start position:0% +the rigid rotor V was zero right and +everything was in the kinetic energy + + align:start position:0% +everything was in the kinetic energy + + + align:start position:0% +everything was in the kinetic energy +well it's not quite true and so for + + align:start position:0% +well it's not quite true and so for + + + align:start position:0% +well it's not quite true and so for +hydrogen so we know this is P squared + + align:start position:0% +hydrogen so we know this is P squared + + + align:start position:0% +hydrogen so we know this is P squared +over 2m you and me'll for the hydrogen + + align:start position:0% +over 2m you and me'll for the hydrogen + + + align:start position:0% +over 2m you and me'll for the hydrogen +atom reduced mass and and and we know + + align:start position:0% +atom reduced mass and and and we know + + + align:start position:0% +atom reduced mass and and and we know +this is just Coulomb's law - e squared + + align:start position:0% +this is just Coulomb's law - e squared + + + align:start position:0% +this is just Coulomb's law - e squared +over 4 PI epsilon 0 H bar squared + + align:start position:0% +over 4 PI epsilon 0 H bar squared + + + align:start position:0% +over 4 PI epsilon 0 H bar squared +there's I'm sorry it was it was so this + + align:start position:0% +there's I'm sorry it was it was so this + + + align:start position:0% +there's I'm sorry it was it was so this +is the classical so these are the parts + + align:start position:0% +is the classical so these are the parts + + + align:start position:0% +is the classical so these are the parts +and but that since it's spherical we're + + align:start position:0% +and but that since it's spherical we're + + + align:start position:0% +and but that since it's spherical we're +not going to work in Cartesian + + align:start position:0% +not going to work in Cartesian + + + align:start position:0% +not going to work in Cartesian +coordinates and in fact that's a very + + align:start position:0% +coordinates and in fact that's a very + + + align:start position:0% +coordinates and in fact that's a very +strong statement if you have a spherical + + align:start position:0% +strong statement if you have a spherical + + + align:start position:0% +strong statement if you have a spherical +problem don't start in Cartesian + + align:start position:0% +problem don't start in Cartesian + + + align:start position:0% +problem don't start in Cartesian +coordinates because it's a horrible mess + + align:start position:0% +coordinates because it's a horrible mess + + + align:start position:0% +coordinates because it's a horrible mess +transforming to spherical polar + + align:start position:0% +transforming to spherical polar + + + align:start position:0% +transforming to spherical polar +coordinates just remember the spherical + + align:start position:0% +coordinates just remember the spherical + + + align:start position:0% +coordinates just remember the spherical +polar quit and okay so you know how + + align:start position:0% +polar quit and okay so you know how + + + align:start position:0% +polar quit and okay so you know how +spherical polar coordinates work I'm not + + align:start position:0% +spherical polar coordinates work I'm not + + + align:start position:0% +spherical polar coordinates work I'm not +going to draw it so the the kinetic + + align:start position:0% +going to draw it so the the kinetic + + + align:start position:0% +going to draw it so the the kinetic +energy term is + + align:start position:0% + + + + align:start position:0% + +and this is the laplacian and that's a + + align:start position:0% +and this is the laplacian and that's a + + + align:start position:0% +and this is the laplacian and that's a +terrible thing and del squared is it + + align:start position:0% +terrible thing and del squared is it + + + align:start position:0% +terrible thing and del squared is it +looks like it's going to be a real + + align:start position:0% +looks like it's going to be a real + + + align:start position:0% +looks like it's going to be a real +nightmare partial with respect to our + + align:start position:0% +nightmare partial with respect to our + + + align:start position:0% +nightmare partial with respect to our +our square parcel with respect to our + + align:start position:0% +our square parcel with respect to our + + + align:start position:0% +our square parcel with respect to our +then we have 1 over R squared sine + + align:start position:0% +then we have 1 over R squared sine + + + align:start position:0% +then we have 1 over R squared sine +squared theta partial with respect to + + align:start position:0% +squared theta partial with respect to + + + align:start position:0% +squared theta partial with respect to +theta sine theta partial with respect to + + align:start position:0% +theta sine theta partial with respect to + + + align:start position:0% +theta sine theta partial with respect to +theta and then a third term 1 over R + + align:start position:0% +theta and then a third term 1 over R + + + align:start position:0% +theta and then a third term 1 over R +squared sine squared I got the square + + align:start position:0% +squared sine squared I got the square + + + align:start position:0% +squared sine squared I got the square +here that's wrong and this is sine + + align:start position:0% +here that's wrong and this is sine + + + align:start position:0% +here that's wrong and this is sine +squared theta I heard a member of mumble + + align:start position:0% +squared theta I heard a member of mumble + + + align:start position:0% +squared theta I heard a member of mumble +over there yeah but I haven't I'm just + + align:start position:0% +over there yeah but I haven't I'm just + + + align:start position:0% +over there yeah but I haven't I'm just +doing del squared right oh yes it looks + + align:start position:0% +doing del squared right oh yes it looks + + + align:start position:0% +doing del squared right oh yes it looks +like a terrible thing all right and the + + align:start position:0% +like a terrible thing all right and the + + + align:start position:0% +like a terrible thing all right and the +last part is second derivative with + + align:start position:0% +last part is second derivative with + + + align:start position:0% +last part is second derivative with +respect to Phi ok this looks like a + + align:start position:0% +respect to Phi ok this looks like a + + + align:start position:0% +respect to Phi ok this looks like a +terrible thing to build to build on but + + align:start position:0% +terrible thing to build to build on but + + + align:start position:0% +terrible thing to build to build on but +with a little bit of trickery and that + + align:start position:0% +with a little bit of trickery and that + + + align:start position:0% +with a little bit of trickery and that +is suppose we multiply this equation by + + align:start position:0% +is suppose we multiply this equation by + + + align:start position:0% +is suppose we multiply this equation by +R squared then + + align:start position:0% + + + + align:start position:0% + +we have killed the r-squared terms here + + align:start position:0% +we have killed the r-squared terms here + + + align:start position:0% +we have killed the r-squared terms here +here and we're going to be able to + + align:start position:0% +here and we're going to be able to + + + align:start position:0% +here and we're going to be able to +separate it and so we are able to write + + align:start position:0% +separate it and so we are able to write + + + align:start position:0% +separate it and so we are able to write +an equation which as the separate ility + + align:start position:0% +an equation which as the separate ility + + + align:start position:0% +an equation which as the separate ility +built-in and so parcel with respect to + + align:start position:0% +built-in and so parcel with respect to + + + align:start position:0% +built-in and so parcel with respect to +our our squared partials with respect to + + align:start position:0% +our our squared partials with respect to + + + align:start position:0% +our our squared partials with respect to +r plus l squared plus 2 mu H R squared V + + align:start position:0% +r plus l squared plus 2 mu H R squared V + + + align:start position:0% +r plus l squared plus 2 mu H R squared V +of our that's a string equation so we + + align:start position:0% +of our that's a string equation so we + + + align:start position:0% +of our that's a string equation so we +have an R dependent term and another our + + align:start position:0% +have an R dependent term and another our + + + align:start position:0% +have an R dependent term and another our +dependent term and if they defy + + align:start position:0% +dependent term and if they defy + + + align:start position:0% +dependent term and if they defy +dependent term all in this one nice + + align:start position:0% +dependent term all in this one nice + + + align:start position:0% +dependent term all in this one nice +operator that we've understood so now + + align:start position:0% +operator that we've understood so now + + + align:start position:0% +operator that we've understood so now +there's one more trick in order for the + + align:start position:0% +there's one more trick in order for the + + + align:start position:0% +there's one more trick in order for the +shorter equation to be separated into a + + align:start position:0% +shorter equation to be separated into a + + + align:start position:0% +shorter equation to be separated into a +Theta Phi part and in our part is we + + align:start position:0% +Theta Phi part and in our part is we + + + align:start position:0% +Theta Phi part and in our part is we +need a commutator and so that commutator + + align:start position:0% +need a commutator and so that commutator + + + align:start position:0% +need a commutator and so that commutator +is this what is the commutator between l + + align:start position:0% +is this what is the commutator between l + + + align:start position:0% +is this what is the commutator between l +squared and any function of R yes + + align:start position:0% + + + + align:start position:0% + +absolutely that's really important we + + align:start position:0% +absolutely that's really important we + + + align:start position:0% +absolutely that's really important we +often encounter operators that depend on + + align:start position:0% +often encounter operators that depend on + + + align:start position:0% +often encounter operators that depend on +different variables and when they do + + align:start position:0% +different variables and when they do + + + align:start position:0% +different variables and when they do +they can do with each other which is an + + align:start position:0% +they can do with each other which is an + + + align:start position:0% +they can do with each other which is an +incredibly convenient thing because that + + align:start position:0% +incredibly convenient thing because that + + + align:start position:0% +incredibly convenient thing because that +means we can set up the problem as a + + align:start position:0% +means we can set up the problem as a + + + align:start position:0% +means we can set up the problem as a +product of eigenfunctions of the + + align:start position:0% +product of eigenfunctions of the + + + align:start position:0% +product of eigenfunctions of the +different operators so this means that + + align:start position:0% +different operators so this means that + + + align:start position:0% +different operators so this means that +we can write a theta phi term which we + + align:start position:0% +we can write a theta phi term which we + + + align:start position:0% +we can write a theta phi term which we +completely know and in our term which we + + align:start position:0% +completely know and in our term which we + + + align:start position:0% +completely know and in our term which we +don't know and contains all of the + + align:start position:0% +don't know and contains all of the + + + align:start position:0% +don't know and contains all of the +interesting stuff + + align:start position:0% + + + + align:start position:0% + +so let's forget about date and Phi let's + + align:start position:0% +so let's forget about date and Phi let's + + + align:start position:0% +so let's forget about date and Phi let's +just look at the the are part okay well + + align:start position:0% +just look at the the are part okay well + + + align:start position:0% +just look at the the are part okay well +the way we separated variables we had + + align:start position:0% +the way we separated variables we had + + + align:start position:0% +the way we separated variables we had +this written equation and we divided by + + align:start position:0% +this written equation and we divided by + + + align:start position:0% +this written equation and we divided by +the wave function which would be our of + + align:start position:0% +the wave function which would be our of + + + align:start position:0% +the wave function which would be our of +our y LM of Theta Phi and on one side of + + align:start position:0% +our y LM of Theta Phi and on one side of + + + align:start position:0% +our y LM of Theta Phi and on one side of +the equality we have only the the angle + + align:start position:0% +the equality we have only the the angle + + + align:start position:0% +the equality we have only the the angle +part and so when we do that when we + + align:start position:0% +part and so when we do that when we + + + align:start position:0% +part and so when we do that when we +divide by r we kill the are part on this + + align:start position:0% +divide by r we kill the are part on this + + + align:start position:0% +divide by r we kill the are part on this +side and on the other side it's the + + align:start position:0% +side and on the other side it's the + + + align:start position:0% +side and on the other side it's the +opposite and so we get a two pieces one + + align:start position:0% +opposite and so we get a two pieces one + + + align:start position:0% +opposite and so we get a two pieces one +or it's only dependent on theta and Phi + + align:start position:0% +or it's only dependent on theta and Phi + + + align:start position:0% +or it's only dependent on theta and Phi +and one is only dependent on our so they + + align:start position:0% +and one is only dependent on our so they + + + align:start position:0% +and one is only dependent on our so they +both have to be a constant so we get two + + align:start position:0% +both have to be a constant so we get two + + + align:start position:0% +both have to be a constant so we get two +separate differential equations and + + align:start position:0% +separate differential equations and + + + align:start position:0% +separate differential equations and +we've already dealt with one of them so + + align:start position:0% +we've already dealt with one of them so + + + align:start position:0% +we've already dealt with one of them so +well you end up getting is one over R + + align:start position:0% +well you end up getting is one over R + + + align:start position:0% +well you end up getting is one over R +times stuff is equal to times R Bar is + + align:start position:0% +times stuff is equal to times R Bar is + + + align:start position:0% +times stuff is equal to times R Bar is +equal to 1 over y LM L square y LM sorry + + align:start position:0% + + + + align:start position:0% + +ok so this is the separation this is all + + align:start position:0% +ok so this is the separation this is all + + + align:start position:0% +ok so this is the separation this is all +our stuff this is all theta stuff and + + align:start position:0% +our stuff this is all theta stuff and + + + align:start position:0% +our stuff this is all theta stuff and +separation constant + + align:start position:0% +separation constant + + + align:start position:0% +separation constant +well this one is inviting a separation + + align:start position:0% +well this one is inviting a separation + + + align:start position:0% +well this one is inviting a separation +constant because l squared operating on + + align:start position:0% +constant because l squared operating on + + + align:start position:0% +constant because l squared operating on +ylm is H bar squared ll plus 1 that's + + align:start position:0% +ylm is H bar squared ll plus 1 that's + + + align:start position:0% +ylm is H bar squared ll plus 1 that's +the separation constant + + align:start position:0% + + + + align:start position:0% + +okay so now let's look for the only time + + align:start position:0% +okay so now let's look for the only time + + + align:start position:0% +okay so now let's look for the only time +at the are part of the differential + + align:start position:0% +at the are part of the differential + + + align:start position:0% +at the are part of the differential +equation and so this is writing out all + + align:start position:0% +equation and so this is writing out all + + + align:start position:0% +equation and so this is writing out all +the pieces honestly we haven't one more + + align:start position:0% + + + + align:start position:0% + +so that's the shorter equation for the + + align:start position:0% +so that's the shorter equation for the + + + align:start position:0% +so that's the shorter equation for the +radial part it looks a little bit + + align:start position:0% +radial part it looks a little bit + + + align:start position:0% +radial part it looks a little bit +annoying the important trick is that + + align:start position:0% +annoying the important trick is that + + + align:start position:0% +annoying the important trick is that +we've we've taken the separator + + align:start position:0% +we've we've taken the separator + + + align:start position:0% +we've we've taken the separator +separation constant and it has an hour + + align:start position:0% +separation constant and it has an hour + + + align:start position:0% +separation constant and it has an hour +dependence but when we divide through by + + align:start position:0% +dependence but when we divide through by + + + align:start position:0% +dependence but when we divide through by +2 mu H R squared and we say oh well + + align:start position:0% +2 mu H R squared and we say oh well + + + align:start position:0% +2 mu H R squared and we say oh well +let's call these two things together the + + align:start position:0% +let's call these two things together the + + + align:start position:0% +let's call these two things together the +L of R this is the effective potential + + align:start position:0% +L of R this is the effective potential + + + align:start position:0% +L of R this is the effective potential +and it depends on the value of L so this + + align:start position:0% +and it depends on the value of L so this + + + align:start position:0% +and it depends on the value of L so this +is just like an ordinary one-dimensional + + align:start position:0% +is just like an ordinary one-dimensional + + + align:start position:0% +is just like an ordinary one-dimensional +problem except now for every value of L + + align:start position:0% +problem except now for every value of L + + + align:start position:0% +problem except now for every value of L +we have a different potential and this + + align:start position:0% +we have a different potential and this + + + align:start position:0% +we have a different potential and this +potential is okay it when L is not equal + + align:start position:0% +potential is okay it when L is not equal + + + align:start position:0% +potential is okay it when L is not equal +to 0 this potential goes to infinity at + + align:start position:0% +to 0 this potential goes to infinity at + + + align:start position:0% +to 0 this potential goes to infinity at +R equals 0 which is bad except it's good + + align:start position:0% +R equals 0 which is bad except it's good + + + align:start position:0% +R equals 0 which is bad except it's good +because it keeps the particle ever from + + align:start position:0% +because it keeps the particle ever from + + + align:start position:0% +because it keeps the particle ever from +getting close to the nucleus + + align:start position:0% + + + + align:start position:0% + +and that's what mr. Schrodinger I'm + + align:start position:0% +and that's what mr. Schrodinger I'm + + + align:start position:0% +and that's what mr. Schrodinger I'm +sorry what mr. Bora was thinking about + + align:start position:0% +sorry what mr. Bora was thinking about + + + align:start position:0% +sorry what mr. Bora was thinking about +that we have only circular orbits or we + + align:start position:0% +that we have only circular orbits or we + + + align:start position:0% +that we have only circular orbits or we +have only orbits that are you know are + + align:start position:0% +have only orbits that are you know are + + + align:start position:0% +have only orbits that are you know are +away from the eye from the place where + + align:start position:0% +away from the eye from the place where + + + align:start position:0% +away from the eye from the place where +the Coulomb interaction would be + + align:start position:0% +the Coulomb interaction would be + + + align:start position:0% +the Coulomb interaction would be +infinite and I mean there are several + + align:start position:0% +infinite and I mean there are several + + + align:start position:0% +infinite and I mean there are several +things is wrong with poor's picture one + + align:start position:0% +things is wrong with poor's picture one + + + align:start position:0% +things is wrong with poor's picture one +is that we have orbits and the other is + + align:start position:0% +is that we have orbits and the other is + + + align:start position:0% +is that we have orbits and the other is +that we don't include l equals zero but + + align:start position:0% +that we don't include l equals zero but + + + align:start position:0% +that we don't include l equals zero but +this is sort of telling you a lot of + + align:start position:0% +this is sort of telling you a lot of + + + align:start position:0% +this is sort of telling you a lot of +really important stuff because the value + + align:start position:0% +really important stuff because the value + + + align:start position:0% +really important stuff because the value +of L determines the importance of this + + align:start position:0% +of L determines the importance of this + + + align:start position:0% +of L determines the importance of this +thing that goes to infinity at R equals + + align:start position:0% +thing that goes to infinity at R equals + + + align:start position:0% +thing that goes to infinity at R equals +zero that has very significant + + align:start position:0% +zero that has very significant + + + align:start position:0% +zero that has very significant +consequences as far as which orbital + + align:start position:0% +consequences as far as which orbital + + + align:start position:0% +consequences as far as which orbital +angular momentum States we're dealing + + align:start position:0% +angular momentum States we're dealing + + + align:start position:0% +angular momentum States we're dealing +with okay so we're going to get the + + align:start position:0% +with okay so we're going to get the + + + align:start position:0% +with okay so we're going to get the +usual l ml a lot of numbers and we're + + align:start position:0% +usual l ml a lot of numbers and we're + + + align:start position:0% +usual l ml a lot of numbers and we're +going to get another one from the radial + + align:start position:0% +going to get another one from the radial + + + align:start position:0% +going to get another one from the radial +part and since this is a 1d equation + + align:start position:0% +part and since this is a 1d equation + + + align:start position:0% +part and since this is a 1d equation +there's only one quantum number and + + align:start position:0% +there's only one quantum number and + + + align:start position:0% +there's only one quantum number and +we're going to call it L and now there's + + align:start position:0% +we're going to call it L and now there's + + + align:start position:0% +we're going to call it L and now there's +this word principle and there's really + + align:start position:0% +this word principle and there's really + + + align:start position:0% +this word principle and there's really +two words principle with an le and + + align:start position:0% +two words principle with an le and + + + align:start position:0% +two words principle with an le and +principle with an al which one do you + + align:start position:0% +principle with an al which one do you + + + align:start position:0% +principle with an al which one do you +think is appropriate I'm sorry I can't + + align:start position:0% +think is appropriate I'm sorry I can't + + + align:start position:0% +think is appropriate I'm sorry I can't +hear hey al is there appropriate one + + align:start position:0% +hear hey al is there appropriate one + + + align:start position:0% +hear hey al is there appropriate one +principle has to do with something + + align:start position:0% +principle has to do with something + + + align:start position:0% +principle has to do with something +fundamental this is you know the + + align:start position:0% +fundamental this is you know the + + + align:start position:0% +fundamental this is you know the +principle has to do with something + + align:start position:0% +principle has to do with something + + + align:start position:0% +principle has to do with something +that's important okay and I can't tell + + align:start position:0% +that's important okay and I can't tell + + + align:start position:0% +that's important okay and I can't tell +you how many times people who should + + align:start position:0% +you how many times people who should + + + align:start position:0% +you how many times people who should +know better use the wrong principle + + align:start position:0% + + + + align:start position:0% + +okay you'll never do that now because + + align:start position:0% +okay you'll never do that now because + + + align:start position:0% +okay you'll never do that now because +you know it's like what's new C over + + align:start position:0% +you know it's like what's new C over + + + align:start position:0% +you know it's like what's new C over +lambda right okay so this is the right + + align:start position:0% +lambda right okay so this is the right + + + align:start position:0% +lambda right okay so this is the right +principle and now let us if we if we do + + align:start position:0% +principle and now let us if we if we do + + + align:start position:0% +principle and now let us if we if we do +something clever and we have the radial + + align:start position:0% +something clever and we have the radial + + + align:start position:0% +something clever and we have the radial +part and we say let us replace it by one + + align:start position:0% +part and we say let us replace it by one + + + align:start position:0% +part and we say let us replace it by one +of our times this new function Chi L bar + + align:start position:0% + + + + align:start position:0% + +well when we do that this equation + + align:start position:0% +well when we do that this equation + + + align:start position:0% +well when we do that this equation +becomes really simple so what we get + + align:start position:0% +becomes really simple so what we get + + + align:start position:0% +becomes really simple so what we get +when we make that substitution is H bar + + align:start position:0% +when we make that substitution is H bar + + + align:start position:0% +when we make that substitution is H bar +squared over 2 mu H second derivative + + align:start position:0% +squared over 2 mu H second derivative + + + align:start position:0% +squared over 2 mu H second derivative +with respect to R plus the L bar minus e + + align:start position:0% + + + + align:start position:0% + +equals 0 that looks like a differential + + align:start position:0% +equals 0 that looks like a differential + + + align:start position:0% +equals 0 that looks like a differential +equation we've seen before + + align:start position:0% +equation we've seen before + + + align:start position:0% +equation we've seen before +it's a simple one dimensional + + align:start position:0% +it's a simple one dimensional + + + align:start position:0% +it's a simple one dimensional +differential equation kinetic energy + + align:start position:0% +differential equation kinetic energy + + + align:start position:0% +differential equation kinetic energy +potential this is not there's some + + align:start position:0% +potential this is not there's some + + + align:start position:0% +potential this is not there's some +kinetic energy hidden in the potential + + align:start position:0% +kinetic energy hidden in the potential + + + align:start position:0% +kinetic energy hidden in the potential +energy but this is simple + + align:start position:0% +energy but this is simple + + + align:start position:0% +energy but this is simple +and we can deal with this a lot I'm not + + align:start position:0% +and we can deal with this a lot I'm not + + + align:start position:0% +and we can deal with this a lot I'm not +going to but if you're going to actually + + align:start position:0% +going to but if you're going to actually + + + align:start position:0% +going to but if you're going to actually +do stuff you're going to be wanting to + + align:start position:0% +do stuff you're going to be wanting to + + + align:start position:0% +do stuff you're going to be wanting to +look at this differential equation okay + + align:start position:0% +look at this differential equation okay + + + align:start position:0% +look at this differential equation okay +but I'm going to forego that pleasure + + align:start position:0% + + + + align:start position:0% + +one of the problems with the radial + + align:start position:0% +one of the problems with the radial + + + align:start position:0% +one of the problems with the radial +equation is the fact that r is a special + + align:start position:0% +equation is the fact that r is a special + + + align:start position:0% +equation is the fact that r is a special +kind of coordinate it can't go negative + + align:start position:0% +kind of coordinate it can't go negative + + + align:start position:0% +kind of coordinate it can't go negative +and so treating the boundary condition + + align:start position:0% +and so treating the boundary condition + + + align:start position:0% +and so treating the boundary condition +for R is equal to 0 is a little subtle + + align:start position:0% + + + + align:start position:0% + +and it turns out + + align:start position:0% +and it turns out + + + align:start position:0% +and it turns out +that when L is equal to zero then R of 0 + + align:start position:0% +that when L is equal to zero then R of 0 + + + align:start position:0% +that when L is equal to zero then R of 0 +is not 0 but for all other values of L R + + align:start position:0% +is not 0 but for all other values of L R + + + align:start position:0% +is not 0 but for all other values of L R +of 0 is 0 and all event of R depends on + + align:start position:0% +of 0 is 0 and all event of R depends on + + + align:start position:0% +of 0 is 0 and all event of R depends on +L being 0 because the electron feels the + + align:start position:0% +L being 0 because the electron feels the + + + align:start position:0% +L being 0 because the electron feels the +nucleus it doesn't experience an + + align:start position:0% +nucleus it doesn't experience an + + + align:start position:0% +nucleus it doesn't experience an +infinite singularity it it feels the + + align:start position:0% +infinite singularity it it feels the + + + align:start position:0% +infinite singularity it it feels the +nucleus and when L is not equal to 0 + + align:start position:0% +nucleus and when L is not equal to 0 + + + align:start position:0% +nucleus and when L is not equal to 0 +then it's sensing the nucleus at a + + align:start position:0% +then it's sensing the nucleus at a + + + align:start position:0% +then it's sensing the nucleus at a +distance and that leads to some very + + align:start position:0% +distance and that leads to some very + + + align:start position:0% +distance and that leads to some very +small splittings called hyperfine and so + + align:start position:0% +small splittings called hyperfine and so + + + align:start position:0% +small splittings called hyperfine and so +there's there's different kinds of + + align:start position:0% +there's there's different kinds of + + + align:start position:0% +there's there's different kinds of +hyperfine structure but anyway this is a + + align:start position:0% +hyperfine structure but anyway this is a + + + align:start position:0% +hyperfine structure but anyway this is a +really subtle and important point ok ok + + align:start position:0% +really subtle and important point ok ok + + + align:start position:0% +really subtle and important point ok ok +yes No ok so and now pictures of + + align:start position:0% +yes No ok so and now pictures of + + + align:start position:0% +yes No ok so and now pictures of +orbitals so we the problem with pictures + + align:start position:0% +orbitals so we the problem with pictures + + + align:start position:0% +orbitals so we the problem with pictures +of orbitals is now we have a function of + + align:start position:0% +of orbitals is now we have a function of + + + align:start position:0% +of orbitals is now we have a function of +three variables and it's equal to some + + align:start position:0% +three variables and it's equal to some + + + align:start position:0% +three variables and it's equal to some +complex number so we need sort of two + + align:start position:0% +complex number so we need sort of two + + + align:start position:0% +complex number so we need sort of two +degrees of freedom to represent a + + align:start position:0% +degrees of freedom to represent a + + + align:start position:0% +degrees of freedom to represent a +complex number and we have three + + align:start position:0% +complex number and we have three + + + align:start position:0% +complex number and we have three +variables and so you know representing + + align:start position:0% +variables and so you know representing + + + align:start position:0% +variables and so you know representing +that on a two-dimensional sheet of paper + + align:start position:0% +that on a two-dimensional sheet of paper + + + align:start position:0% +that on a two-dimensional sheet of paper +is horrible but we have this wonderful + + align:start position:0% +is horrible but we have this wonderful + + + align:start position:0% +is horrible but we have this wonderful +factorization where we have our R and we + + align:start position:0% +factorization where we have our R and we + + + align:start position:0% +factorization where we have our R and we +could draw that easily we don't need any + + align:start position:0% +could draw that easily we don't need any + + + align:start position:0% +could draw that easily we don't need any +special skill and we have ylm of theta + + align:start position:0% +special skill and we have ylm of theta + + + align:start position:0% +special skill and we have ylm of theta +phi and we've got lots of practice with + + align:start position:0% +phi and we've got lots of practice with + + + align:start position:0% +phi and we've got lots of practice with +that although what we've practiced with + + align:start position:0% +that although what we've practiced with + + + align:start position:0% +that although what we've practiced with +may not be completely understood yet but + + align:start position:0% +may not be completely understood yet but + + + align:start position:0% +may not be completely understood yet but +so we have ways of representing these + + align:start position:0% +so we have ways of representing these + + + align:start position:0% +so we have ways of representing these +and and so we go through the the + + align:start position:0% +and and so we go through the the + + + align:start position:0% +and and so we go through the the +understanding of the hydrogen atom + + align:start position:0% +understanding of the hydrogen atom + + + align:start position:0% +understanding of the hydrogen atom +by looking at these two things + + align:start position:0% +by looking at these two things + + + align:start position:0% +by looking at these two things +separately okay now for the radial part + + align:start position:0% +separately okay now for the radial part + + + align:start position:0% +separately okay now for the radial part +the energy levels where this is the + + align:start position:0% +the energy levels where this is the + + + align:start position:0% +the energy levels where this is the +Redbird constant it's a combination of + + align:start position:0% +Redbird constant it's a combination of + + + align:start position:0% +Redbird constant it's a combination of +fundamental constants and for hydrogen + + align:start position:0% +fundamental constants and for hydrogen + + + align:start position:0% +fundamental constants and for hydrogen +the Redbird constant is equal to 109 + + align:start position:0% +the Redbird constant is equal to 109 + + + align:start position:0% +the Redbird constant is equal to 109 +seven thirty seven point three one nine + + align:start position:0% +seven thirty seven point three one nine + + + align:start position:0% +seven thirty seven point three one nine +there's actually more digits wave + + align:start position:0% +there's actually more digits wave + + + align:start position:0% +there's actually more digits wave +numbers times nu eight over a mu + + align:start position:0% +numbers times nu eight over a mu + + + align:start position:0% +numbers times nu eight over a mu +infinite well this is actually the + + align:start position:0% +infinite well this is actually the + + + align:start position:0% +infinite well this is actually the +Redbird constant for an infinite mass + + align:start position:0% + + + + align:start position:0% + +now and so mu H is equal to the mass of + + align:start position:0% +now and so mu H is equal to the mass of + + + align:start position:0% +now and so mu H is equal to the mass of +the electron times the mass of the + + align:start position:0% +the electron times the mass of the + + + align:start position:0% +the electron times the mass of the +proton over the mass of the electron + + align:start position:0% +proton over the mass of the electron + + + align:start position:0% +proton over the mass of the electron +plus the mass of the proton now the mass + + align:start position:0% +plus the mass of the proton now the mass + + + align:start position:0% +plus the mass of the proton now the mass +of the proton is much bigger than the + + align:start position:0% +of the proton is much bigger than the + + + align:start position:0% +of the proton is much bigger than the +mass of the electron and so you can use + + align:start position:0% +mass of the electron and so you can use + + + align:start position:0% +mass of the electron and so you can use +this as a trick you can say well what is + + align:start position:0% +this as a trick you can say well what is + + + align:start position:0% +this as a trick you can say well what is +it well we know what this is it's easy + + align:start position:0% +it well we know what this is it's easy + + + align:start position:0% +it well we know what this is it's easy +to calculate but there are two limits + + align:start position:0% +to calculate but there are two limits + + + align:start position:0% +to calculate but there are two limits +what is the smallest possible reduced + + align:start position:0% +what is the smallest possible reduced + + + align:start position:0% +what is the smallest possible reduced +mass and that would be for if if the + + align:start position:0% +mass and that would be for if if the + + + align:start position:0% +mass and that would be for if if the +mass of the proton is infinite then we + + align:start position:0% +mass of the proton is infinite then we + + + align:start position:0% +mass of the proton is infinite then we +just get the mass of the electrons + + align:start position:0% +just get the mass of the electrons + + + align:start position:0% +just get the mass of the electrons +that's the biggest reduced mass and the + + align:start position:0% +that's the biggest reduced mass and the + + + align:start position:0% +that's the biggest reduced mass and the +smallest is if we have positronium where + + align:start position:0% +smallest is if we have positronium where + + + align:start position:0% +smallest is if we have positronium where +we have an electron bound to a to a + + align:start position:0% +we have an electron bound to a to a + + + align:start position:0% +we have an electron bound to a to a +proton and then when we do that we get + + align:start position:0% +proton and then when we do that we get + + + align:start position:0% +proton and then when we do that we get +1/2 I'm sorry it's not a proton it's to + + align:start position:0% +1/2 I'm sorry it's not a proton it's to + + + align:start position:0% +1/2 I'm sorry it's not a proton it's to +a positive positive positively charged + + align:start position:0% +a positive positive positively charged + + + align:start position:0% +a positive positive positively charged +particle which we call positive a + + align:start position:0% +particle which we call positive a + + + align:start position:0% +particle which we call positive a +positron and so it's electron pot and so + + align:start position:0% +positron and so it's electron pot and so + + + align:start position:0% +positron and so it's electron pot and so +each of the terms here is one is the + + align:start position:0% +each of the terms here is one is the + + + align:start position:0% +each of the terms here is one is the +mass of the electron and so the range is + + align:start position:0% +mass of the electron and so the range is + + + align:start position:0% +mass of the electron and so the range is +from 1/2 a me to Emmy the pending on + + align:start position:0% +from 1/2 a me to Emmy the pending on + + + align:start position:0% +from 1/2 a me to Emmy the pending on +what particles you're dealing with and + + align:start position:0% +what particles you're dealing with and + + + align:start position:0% +what particles you're dealing with and +so that's a useful thing and so the rid + + align:start position:0% +so that's a useful thing and so the rid + + + align:start position:0% +so that's a useful thing and so the rid +berg constant for hydrogen is smaller + + align:start position:0% +berg constant for hydrogen is smaller + + + align:start position:0% +berg constant for hydrogen is smaller +than the reduced mass of the infinite + + align:start position:0% +than the reduced mass of the infinite + + + align:start position:0% +than the reduced mass of the infinite +I'm sorry it's smaller than that for the + + align:start position:0% +I'm sorry it's smaller than that for the + + + align:start position:0% +I'm sorry it's smaller than that for the +infinite the mass nucleus and it is the + + align:start position:0% +infinite the mass nucleus and it is the + + + align:start position:0% +infinite the mass nucleus and it is the +value that made mr. four very happy 679 + + align:start position:0% +value that made mr. four very happy 679 + + + align:start position:0% +value that made mr. four very happy 679 +so the important thing is this mass + + align:start position:0% +so the important thing is this mass + + + align:start position:0% +so the important thing is this mass +killed or reduced mass scale dripper + + align:start position:0% +killed or reduced mass scale dripper + + + align:start position:0% +killed or reduced mass scale dripper +constant explains to a part in 10 to the + + align:start position:0% +constant explains to a part in 10 to the + + + align:start position:0% +constant explains to a part in 10 to the +10th all of the energy levels of one + + align:start position:0% +10th all of the energy levels of one + + + align:start position:0% +10th all of the energy levels of one +electron systems hydrogen helium plus + + align:start position:0% +electron systems hydrogen helium plus + + + align:start position:0% +electron systems hydrogen helium plus +lithium 2-plus + + align:start position:0% +lithium 2-plus + + + align:start position:0% +lithium 2-plus +that's it and that's fantastic + + align:start position:0% + + + + align:start position:0% + +okay now we have to talk to become + + align:start position:0% +okay now we have to talk to become + + + align:start position:0% +okay now we have to talk to become +really familiar with this rnl of our + + align:start position:0% +really familiar with this rnl of our + + + align:start position:0% +really familiar with this rnl of our +function + + align:start position:0% + + + + align:start position:0% + +and one of the questions is how many + + align:start position:0% +and one of the questions is how many + + + align:start position:0% +and one of the questions is how many +radial nodes and you know that for one s + + align:start position:0% +radial nodes and you know that for one s + + + align:start position:0% +radial nodes and you know that for one s +there aren't any nodes and you know for + + align:start position:0% +there aren't any nodes and you know for + + + align:start position:0% +there aren't any nodes and you know for +two P + + align:start position:0% +two P + + + align:start position:0% +two P +there aren't any radial nodes and so + + align:start position:0% +there aren't any radial nodes and so + + + align:start position:0% +there aren't any radial nodes and so +what we need is something that that goes + + align:start position:0% +what we need is something that that goes + + + align:start position:0% +what we need is something that that goes +like n minus L minus 1 the number of + + align:start position:0% +like n minus L minus 1 the number of + + + align:start position:0% +like n minus L minus 1 the number of +radial nodes which is all you need to + + align:start position:0% +radial nodes which is all you need to + + + align:start position:0% +radial nodes which is all you need to +know about the radio wave function is + + align:start position:0% +know about the radio wave function is + + + align:start position:0% +know about the radio wave function is +how many notes are are and how far they + + align:start position:0% +how many notes are are and how far they + + + align:start position:0% +how many notes are are and how far they +apart and what's the amplitude of each + + align:start position:0% +apart and what's the amplitude of each + + + align:start position:0% +apart and what's the amplitude of each +loop between nodes semi-classical theory + + align:start position:0% +loop between nodes semi-classical theory + + + align:start position:0% +loop between nodes semi-classical theory +gives you all of that and often when + + align:start position:0% +gives you all of that and often when + + + align:start position:0% +gives you all of that and often when +you're calculating an integral all you + + align:start position:0% +you're calculating an integral all you + + + align:start position:0% +you're calculating an integral all you +care about is the amplitude in the first + + align:start position:0% +care about is the amplitude in the first + + + align:start position:0% +care about is the amplitude in the first +loop and so instead of having to + + align:start position:0% +loop and so instead of having to + + + align:start position:0% +loop and so instead of having to +evaluate an integral you just uh you + + align:start position:0% +evaluate an integral you just uh you + + + align:start position:0% +evaluate an integral you just uh you +just figure out what is the the envelope + + align:start position:0% +just figure out what is the the envelope + + + align:start position:0% +just figure out what is the the envelope +function based on the classical momentum + + align:start position:0% +function based on the classical momentum + + + align:start position:0% +function based on the classical momentum +function okay now the thing that + + align:start position:0% +function okay now the thing that + + + align:start position:0% +function okay now the thing that +everybody's been waiting for spin + + align:start position:0% + + + + align:start position:0% + +so remember we know an angular momentum + + align:start position:0% +so remember we know an angular momentum + + + align:start position:0% +so remember we know an angular momentum +is our cross peak and we know that there + + align:start position:0% +is our cross peak and we know that there + + + align:start position:0% +is our cross peak and we know that there +isn't any internal structure or at least + + align:start position:0% +isn't any internal structure or at least + + + align:start position:0% +isn't any internal structure or at least +we don't know about internal structure + + align:start position:0% +we don't know about internal structure + + + align:start position:0% +we don't know about internal structure +of the electron or proton and so we + + align:start position:0% +of the electron or proton and so we + + + align:start position:0% +of the electron or proton and so we +can't somehow say well it's our cross P + + align:start position:0% +can't somehow say well it's our cross P + + + align:start position:0% +can't somehow say well it's our cross P +so we have the same on effect so we can + + align:start position:0% +so we have the same on effect so we can + + + align:start position:0% +so we have the same on effect so we can +look at the same on effect for an atom + + align:start position:0% +look at the same on effect for an atom + + + align:start position:0% +look at the same on effect for an atom +in a magnetic field and we have several + + align:start position:0% +in a magnetic field and we have several + + + align:start position:0% +in a magnetic field and we have several +things that we know so we have the + + align:start position:0% +things that we know so we have the + + + align:start position:0% +things that we know so we have the +magnetic moment of the electron is equal + + align:start position:0% +magnetic moment of the electron is equal + + + align:start position:0% +magnetic moment of the electron is equal +to minus the charge on the electron + + align:start position:0% +to minus the charge on the electron + + + align:start position:0% +to minus the charge on the electron +times 2m e times L well that's an + + align:start position:0% +times 2m e times L well that's an + + + align:start position:0% +times 2m e times L well that's an +angular momentum so if we had + + align:start position:0% +angular momentum so if we had + + + align:start position:0% +angular momentum so if we had +circulating charge + + align:start position:0% +circulating charge + + + align:start position:0% +circulating charge +well that circulating charge will + + align:start position:0% +well that circulating charge will + + + align:start position:0% +well that circulating charge will +produce a magnetic moment which has a + + align:start position:0% +produce a magnetic moment which has a + + + align:start position:0% +produce a magnetic moment which has a +magnitude which is related to the + + align:start position:0% +magnitude which is related to the + + + align:start position:0% +magnitude which is related to the +velocity and well what is L divided by + + align:start position:0% +velocity and well what is L divided by + + + align:start position:0% +velocity and well what is L divided by +mass it's a velocity and we have the + + align:start position:0% +mass it's a velocity and we have the + + + align:start position:0% +mass it's a velocity and we have the +charge here so this is a perfectly + + align:start position:0% +charge here so this is a perfectly + + + align:start position:0% +charge here so this is a perfectly +reasonable thing and so and that's good + + align:start position:0% +reasonable thing and so and that's good + + + align:start position:0% +reasonable thing and so and that's good +because we know that if we have + + align:start position:0% +because we know that if we have + + + align:start position:0% +because we know that if we have +electrons with some kind of internal + + align:start position:0% +electrons with some kind of internal + + + align:start position:0% +electrons with some kind of internal +structure we know what this is going to + + align:start position:0% +structure we know what this is going to + + + align:start position:0% +structure we know what this is going to +do so now a magnetic potential is equal + + align:start position:0% +do so now a magnetic potential is equal + + + align:start position:0% +do so now a magnetic potential is equal +to minus the magnetic moment times the + + align:start position:0% +to minus the magnetic moment times the + + + align:start position:0% +to minus the magnetic moment times the +external magnetic field and so what we + + align:start position:0% +external magnetic field and so what we + + + align:start position:0% +external magnetic field and so what we +have is e BC LZ + + align:start position:0% +have is e BC LZ + + + align:start position:0% +have is e BC LZ +over to me well this is another very + + align:start position:0% +over to me well this is another very + + + align:start position:0% +over to me well this is another very +good thing because not only do we know + + align:start position:0% +good thing because not only do we know + + + align:start position:0% +good thing because not only do we know +what this is we know that it has only + + align:start position:0% +what this is we know that it has only + + + align:start position:0% +what this is we know that it has only +diagonal elements and so we can do first + + align:start position:0% +diagonal elements and so we can do first + + + align:start position:0% +diagonal elements and so we can do first +order perturbation theory this is so + + align:start position:0% +order perturbation theory this is so + + + align:start position:0% +order perturbation theory this is so +easy this if this is the Hamiltonian we + + align:start position:0% +easy this if this is the Hamiltonian we + + + align:start position:0% +easy this if this is the Hamiltonian we +can just tack that on and it adds an + + align:start position:0% +can just tack that on and it adds an + + + align:start position:0% +can just tack that on and it adds an +extra splitting to our energy levels the + + align:start position:0% + + + + align:start position:0% + +only tricky thing is we don't know that + + align:start position:0% +only tricky thing is we don't know that + + + align:start position:0% +only tricky thing is we don't know that +it's LZ we just know that it has a + + align:start position:0% +it's LZ we just know that it has a + + + align:start position:0% +it's LZ we just know that it has a +magnetic moment or could have a magnetic + + align:start position:0% +magnetic moment or could have a magnetic + + + align:start position:0% +magnetic moment or could have a magnetic +net magnetic moment okay and so this + + align:start position:0% +net magnetic moment okay and so this + + + align:start position:0% +net magnetic moment okay and so this +wonderful experiment suppose you start + + align:start position:0% +wonderful experiment suppose you start + + + align:start position:0% +wonderful experiment suppose you start +with a 1s state and you go to a 2p State + + align:start position:0% +with a 1s state and you go to a 2p State + + + align:start position:0% +with a 1s state and you go to a 2p State +now this is the this implies that we + + align:start position:0% +now this is the this implies that we + + + align:start position:0% +now this is the this implies that we +know something about the selection rules + + align:start position:0% +know something about the selection rules + + + align:start position:0% +know something about the selection rules +for electromagnetic transitions and so + + align:start position:0% +for electromagnetic transitions and so + + + align:start position:0% +for electromagnetic transitions and so +for an electric dipole transition we go + + align:start position:0% +for an electric dipole transition we go + + + align:start position:0% +for an electric dipole transition we go +from s 1 s 2 2 P now this is not how it + + align:start position:0% +from s 1 s 2 2 P now this is not how it + + + align:start position:0% +from s 1 s 2 2 P now this is not how it +was done initially because that was this + + align:start position:0% +was done initially because that was this + + + align:start position:0% +was done initially because that was this +the frequency of this transition is well + + align:start position:0% +the frequency of this transition is well + + + align:start position:0% +the frequency of this transition is well +into the vacuum ultraviolet and then in + + align:start position:0% +into the vacuum ultraviolet and then in + + + align:start position:0% +into the vacuum ultraviolet and then in +the days when quantum mechanics was + + align:start position:0% +the days when quantum mechanics was + + + align:start position:0% +the days when quantum mechanics was +being developed that was a hard + + align:start position:0% +being developed that was a hard + + + align:start position:0% +being developed that was a hard +experiment so one used an s to P + + align:start position:0% +experiment so one used an s to P + + + align:start position:0% +experiment so one used an s to P +transition on some other atom like + + align:start position:0% +transition on some other atom like + + + align:start position:0% +transition on some other atom like +mercury but let's pretend it was + + align:start position:0% +mercury but let's pretend it was + + + align:start position:0% +mercury but let's pretend it was +hydrogen so this is an angular momentum + + align:start position:0% +hydrogen so this is an angular momentum + + + align:start position:0% +hydrogen so this is an angular momentum +of 0 so we would expect it would be ml + + align:start position:0% +of 0 so we would expect it would be ml + + + align:start position:0% +of 0 so we would expect it would be ml +equals 0 and here we have it could split + + align:start position:0% +equals 0 and here we have it could split + + + align:start position:0% +equals 0 and here we have it could split +into three components and this is ml + + align:start position:0% +into three components and this is ml + + + align:start position:0% +into three components and this is ml +equals 1 0 and minus 1 because this + + align:start position:0% +equals 1 0 and minus 1 because this + + + align:start position:0% +equals 1 0 and minus 1 because this +minus minus sign there was a minus sign + + align:start position:0% +minus minus sign there was a minus sign + + + align:start position:0% +minus minus sign there was a minus sign +somewhere anyway that's what we expect + + align:start position:0% +somewhere anyway that's what we expect + + + align:start position:0% +somewhere anyway that's what we expect +and so being naive + + align:start position:0% +and so being naive + + + align:start position:0% +and so being naive +you might expect transitions like this + + align:start position:0% + + + + align:start position:0% + +well the transitions where you do not + + align:start position:0% +well the transitions where you do not + + + align:start position:0% +well the transitions where you do not +change the projection quantum number are + + align:start position:0% +change the projection quantum number are + + + align:start position:0% +change the projection quantum number are +done with Z polarized radiation and so + + align:start position:0% +done with Z polarized radiation and so + + + align:start position:0% +done with Z polarized radiation and so +if it's Z polarize you get only Delta M + + align:start position:0% +if it's Z polarize you get only Delta M + + + align:start position:0% +if it's Z polarize you get only Delta M +L equals zero and if you're back some + + align:start position:0% +L equals zero and if you're back some + + + align:start position:0% +L equals zero and if you're back some +wine you have Delta ml equals plus minus + + align:start position:0% +wine you have Delta ml equals plus minus + + + align:start position:0% +wine you have Delta ml equals plus minus +one so depending on how the experiment + + align:start position:0% +one so depending on how the experiment + + + align:start position:0% +one so depending on how the experiment +was done you would expect to see one two + + align:start position:0% +was done you would expect to see one two + + + align:start position:0% +was done you would expect to see one two +or three is a mod components and they + + align:start position:0% +or three is a mod components and they + + + align:start position:0% +or three is a mod components and they +did the experiment and they saw more + + align:start position:0% +did the experiment and they saw more + + + align:start position:0% +did the experiment and they saw more +than three components they saw five + + align:start position:0% +than three components they saw five + + + align:start position:0% +than three components they saw five +components and that's puzzling for a + + align:start position:0% +components and that's puzzling for a + + + align:start position:0% +components and that's puzzling for a +number of reasons but they saw five + + align:start position:0% +number of reasons but they saw five + + + align:start position:0% +number of reasons but they saw five +components so they knew that there was + + align:start position:0% +components so they knew that there was + + + align:start position:0% +components so they knew that there was +something else going on and so you have + + align:start position:0% +something else going on and so you have + + + align:start position:0% +something else going on and so you have +to try to collect enough information to + + align:start position:0% +to try to collect enough information to + + + align:start position:0% +to try to collect enough information to +have a simple-minded picture that will + + align:start position:0% +have a simple-minded picture that will + + + align:start position:0% +have a simple-minded picture that will +will explain it all so one thing you + + align:start position:0% +will explain it all so one thing you + + + align:start position:0% +will explain it all so one thing you +might do is say okay suppose there is + + align:start position:0% +might do is say okay suppose there is + + + align:start position:0% +might do is say okay suppose there is +another quantum number another thing and + + align:start position:0% +another quantum number another thing and + + + align:start position:0% +another quantum number another thing and +we're going to call it spin and we don't + + align:start position:0% +we're going to call it spin and we don't + + + align:start position:0% +we're going to call it spin and we don't +know whether spin is integer or half + + align:start position:0% +know whether spin is integer or half + + + align:start position:0% +know whether spin is integer or half +integer we know from our exercise with + + align:start position:0% +integer we know from our exercise with + + + align:start position:0% +integer we know from our exercise with +commutation rules that both half integer + + align:start position:0% +commutation rules that both half integer + + + align:start position:0% +commutation rules that both half integer +and integer angular momenta are possible + + align:start position:0% +and integer angular momenta are possible + + + align:start position:0% +and integer angular momenta are possible +and so we can say we have a spin and it + + align:start position:0% +and so we can say we have a spin and it + + + align:start position:0% +and so we can say we have a spin and it +could be one half it could be one it + + align:start position:0% +could be one half it could be one it + + + align:start position:0% +could be one half it could be one it +could be anything and then we start + + align:start position:0% +could be anything and then we start + + + align:start position:0% +could be anything and then we start +looking at the details of what we + + align:start position:0% +looking at the details of what we + + + align:start position:0% +looking at the details of what we +observe and what we find is all we need + + align:start position:0% +observe and what we find is all we need + + + align:start position:0% +observe and what we find is all we need +to spin 1/2 to account for almost + + align:start position:0% +to spin 1/2 to account for almost + + + align:start position:0% +to spin 1/2 to account for almost +everything however if it were spend 1/2 + + align:start position:0% +everything however if it were spend 1/2 + + + align:start position:0% +everything however if it were spend 1/2 +then you get to here and you get you'd + + align:start position:0% +then you get to here and you get you'd + + + align:start position:0% +then you get to here and you get you'd +get to here to here and to here and + + align:start position:0% +get to here to here and to here and + + + align:start position:0% +get to here to here and to here and +six that's bigger than five so you need + + align:start position:0% +six that's bigger than five so you need + + + align:start position:0% +six that's bigger than five so you need +to know something else + + align:start position:0% +to know something else + + + align:start position:0% +to know something else +and one thing is quite reasonable you + + align:start position:0% +and one thing is quite reasonable you + + + align:start position:0% +and one thing is quite reasonable you +can say well the spin thing is + + align:start position:0% +can say well the spin thing is + + + align:start position:0% +can say well the spin thing is +mysterious and electromagnetic radiation + + align:start position:0% +mysterious and electromagnetic radiation + + + align:start position:0% +mysterious and electromagnetic radiation +acts on the spatial coordinates and + + align:start position:0% +acts on the spatial coordinates and + + + align:start position:0% +acts on the spatial coordinates and +there aren't any spatial coordinates of + + align:start position:0% +there aren't any spatial coordinates of + + + align:start position:0% +there aren't any spatial coordinates of +the internal structure of the electron + + align:start position:0% +the internal structure of the electron + + + align:start position:0% +the internal structure of the electron +and so we have a selection rule Delta M + + align:start position:0% +and so we have a selection rule Delta M + + + align:start position:0% +and so we have a selection rule Delta M +s equals zero that still doesn't do it + + align:start position:0% +s equals zero that still doesn't do it + + + align:start position:0% +s equals zero that still doesn't do it +you still need something else and that + + align:start position:0% +you still need something else and that + + + align:start position:0% +you still need something else and that +is that the proportionality constant + + align:start position:0% +is that the proportionality constant + + + align:start position:0% +is that the proportionality constant +between the angular momentum and the + + align:start position:0% +between the angular momentum and the + + + align:start position:0% +between the angular momentum and the +energy which is called the G factor for + + align:start position:0% +energy which is called the G factor for + + + align:start position:0% +energy which is called the G factor for +for any orbital angular momentum the G + + align:start position:0% +for any orbital angular momentum the G + + + align:start position:0% +for any orbital angular momentum the G +factor is one or the proportionality + + align:start position:0% +factor is one or the proportionality + + + align:start position:0% +factor is one or the proportionality +constant is one so the G factor is L and + + align:start position:0% +constant is one so the G factor is L and + + + align:start position:0% +constant is one so the G factor is L and +the G factor for the electron turns out + + align:start position:0% +the G factor for the electron turns out + + + align:start position:0% +the G factor for the electron turns out +to be - not exactly - just a little more + + align:start position:0% +to be - not exactly - just a little more + + + align:start position:0% +to be - not exactly - just a little more +than two Nobel Prize for that and and so + + align:start position:0% +than two Nobel Prize for that and and so + + + align:start position:0% +than two Nobel Prize for that and and so +with those extra little things then + + align:start position:0% +with those extra little things then + + + align:start position:0% +with those extra little things then +every detail of the same on effect is + + align:start position:0% +every detail of the same on effect is + + + align:start position:0% +every detail of the same on effect is +understood and we say oh the electron + + align:start position:0% +understood and we say oh the electron + + + align:start position:0% +understood and we say oh the electron +has a spin of 1/2 and it like it acts + + align:start position:0% +has a spin of 1/2 and it like it acts + + + align:start position:0% +has a spin of 1/2 and it like it acts +like an angular matter it obeys the + + align:start position:0% +like an angular matter it obeys the + + + align:start position:0% +like an angular matter it obeys the +angular momentum commutation rules it + + align:start position:0% +angular momentum commutation rules it + + + align:start position:0% +angular momentum commutation rules it +also obeys the commutation rules I won't + + align:start position:0% +also obeys the commutation rules I won't + + + align:start position:0% +also obeys the commutation rules I won't +say that ok so I should stop there are + + align:start position:0% +say that ok so I should stop there are + + + align:start position:0% +say that ok so I should stop there are +other things that provide us information + + align:start position:0% +other things that provide us information + + + align:start position:0% +other things that provide us information +that there is something else and one I'm + + align:start position:0% +that there is something else and one I'm + + + align:start position:0% +that there is something else and one I'm +I'm called by some people the spin orbit + + align:start position:0% +I'm called by some people the spin orbit + + + align:start position:0% +I'm called by some people the spin orbit +kid because I've made a whole lot of + + align:start position:0% +kid because I've made a whole lot of + + + align:start position:0% +kid because I've made a whole lot of +mileage on using spin orbit splittings + + align:start position:0% +mileage on using spin orbit splittings + + + align:start position:0% +mileage on using spin orbit splittings +and the spin orbit Hamiltonian has the + + align:start position:0% +and the spin orbit Hamiltonian has the + + + align:start position:0% +and the spin orbit Hamiltonian has the +form l dot s and this gives rise to + + align:start position:0% +form l dot s and this gives rise to + + + align:start position:0% +form l dot s and this gives rise to +splittings of a doublet P state for + + align:start position:0% +splittings of a doublet P state for + + + align:start position:0% +splittings of a doublet P state for +example as what you would see in the + + align:start position:0% +example as what you would see in the + + + align:start position:0% +example as what you would see in the +excited state of hydrogen into two + + align:start position:0% +excited state of hydrogen into two + + + align:start position:0% +excited state of hydrogen into two +components at zero field + + align:start position:0% +components at zero field + + + align:start position:0% +components at zero field +and so there's all sorts of really + + align:start position:0% +and so there's all sorts of really + + + align:start position:0% +and so there's all sorts of really +wonderful stuff and I'm going to cheat + + align:start position:0% +wonderful stuff and I'm going to cheat + + + align:start position:0% +wonderful stuff and I'm going to cheat +you out of almost all of it because + + align:start position:0% +you out of almost all of it because + + + align:start position:0% +you out of almost all of it because +we're going to go over to the + + align:start position:0% +we're going to go over to the + + + align:start position:0% +we're going to go over to the +semi-classical picture next time and + + align:start position:0% +semi-classical picture next time and + + + align:start position:0% +semi-classical picture next time and +we'll understand everything about rid + + align:start position:0% +we'll understand everything about rid + + + align:start position:0% +we'll understand everything about rid +Berk States and about how do we how do + + align:start position:0% +Berk States and about how do we how do + + + align:start position:0% +Berk States and about how do we how do +we estimate everything having to do with + + align:start position:0% +we estimate everything having to do with + + + align:start position:0% +we estimate everything having to do with +the radial part of the wave function and + + align:start position:0% +the radial part of the wave function and + + + align:start position:0% +the radial part of the wave function and +there are some astonishing things okay \ No newline at end of file diff --git a/A6Ud6oUCRak.txt b/A6Ud6oUCRak.txt new file mode 100644 index 0000000000000000000000000000000000000000..704f19700a1fb43b4712961ce0fa052061c5aa08 --- /dev/null +++ b/A6Ud6oUCRak.txt @@ -0,0 +1,2186 @@ +PATRICK WINSTON: Here we are, +down to the final sprint. + +Three to go. + +And we're going to take some of +the last three, maybe two + +of the last three, to talk a +little bit about stuff having + +to do with probabilistic +approaches-- + +use of probability in artificial +intelligence. + +Now, for many of you, this +will be kind of a review, + +because I know many of you +learned about probability over + +the [? sand ?] table and +every year since then. + +But maybe we'll put another +little twist into it, + +especially toward the end of +the hour when we get into a + +discussion of that which has +come to be called belief nets. + +But first, I was driving in this +morning, and I was quite + +astonished to see, as I drove +in, this thing here. + +And my first reaction was, oh +my god, it's the world's + +greatest hack. + +And then I decided, well, maybe +it's a piece of art. + +So I'd like to address the +question of how I could come + +to grips with that issue. + +There's a distinct possibility +that this thing is a + +consequence of a hat, possibly +the result of + +some kind of art show. + +And in any event, some sort of +statue appeared, and statues + +don't usually appear +like that. + +So I got the possibility of +thinking about how all these + +things might occur together +or not occur together. + +So the natural thing is to +build myself some sort of + +table to keep track of +my observations. + +So I have three columns +in my table. + +I've got the possibility of +a statue appearing, a hack + +having occurred, and some +sort of art show. + +And so I can make a table of all +the combinations of those + +things that might appear. + +And I happen to have already +guessed that there are going + +to be eight rows in my table. + +So it's going to +look like this. + +And this is the set of +combinations in this row where + +none of that occurs at all. + +And down here is the situation +where all of + +those things occur. + +After all, it's possible that +we can have an art show and + +have a hack be a legitimate +participant in the art show. + +That's why we have +that final row. + +So we have all manner of +combinations in between. + +So those are those +combinations. + +Then we have F, F, T, T, F, F, +T, T, F, T, F, T, F, T, F, T. + +So it's plain that the number of +rows in the table, or these + +binary possibilities, is 2 to +the number of variables. + +And that could be +a big number. + +In fact, I'd love to do a bigger +example, but I don't + +have the patience to do it. + +But anyhow, what we might do is +in order to figure out how + +likely any of these combinations +are, is we might + +have observed the area outside +the student center and rest of + +campus over a long period of +time and keep track of what + +happens on 1,000 days. + +Or maybe 1,000 months +or 1,000 years. + +I don't know. + +The trouble is, these events +don't happen very often. + +So the period of time that I use +for measurement needs to + +be fairly long. + +Probably a day is not +short enough. + +But in any case, I can keep a +tally of how often I see these + +various combinations. + +So this one might be, for +example, 405, this one might + +be 45, this one might be +225, this one might + +be 40, and so on. + +And so having done all those +measurements, kept track of + +all that data, then I could +say, well, the probability + +that at any given time period +one of these things occurs + +will just be the frequency-- + +the number of tallies +divided by the + +total number of tallies. + +So that would be a number +between 0 and 1. + +So that's the probability for +each of these events. + +And it's readily calculated +from my data. + +And once I do that, then I can +say that I got myself a joint + +probability table, and I could +perform all manner of miracles + +using that joint probability +table. + +So let me perform a few +of those miracles, + +while we're at it. + +There's the table. + +And now, what I want to do +is I want to count up the + +probability in all the rows +where the statue appears. + +So that's going to be +the probability + +of the statue appearing. + +So I'll just check off those +four boxes there. + +And it looks like the +probability of the statue + +appearing is about 0.355 +in my model. + +I don't think it's quite that +frequent, but this is a + +classroom exercise, right? + +So I can make up whatever +numbers I want. + +Now, I could say, well, what's +the probability of a statue + +occurring given that there's +an art show? + +Well, I can limit my tallies to +those in which art show is + +true, like so. + +And in that case, +the probability + +has just zoomed up. + +So if I know there's an art +show, there's a much higher + +probability that a statue +will appear. + +And if I know there's a hack as +well as an art show going + +on, it goes up higher +still to 0.9. + +We can also do other +kinds of things. + +For example, we can go back +to the original table. + +And instead of counting up the +probability we've got a + +statue, as we just did, we're +going to calculate the + +probability that there +is an art show. + +I guess that would be that one +and that one, not that one, + +but that one. + +So the probability there's an +art show is one chance in 10. + +Or we can do the same +thing with a hack. + +In that case, we get that one +off, that one on, that one + +off, that one on, that +one off, that one + +on, that one off. + +So the probability of a hack +on any given time period is + +about 50-50. + +So I've cooked up this little +demo so it does the "ands" of + +all these things. + +It could do "ors," too, with +a little more work. + +But these are just the "ands" of +these various combinations. + +Then you can ask more +complicated questions, like + +for example, you could say, what +is the probability of a + +hack given that there's +a statue? + +And that would be limiting the +calculations to those rows in + +which the statue +thing is true. + +And then what I get is 0.781. + +Now, what would happen to the +probability that it's a hack + +if I know that there's +an art show? + +Will that number +go up or down? + +Well, let's try it. + +Ah, it went down. + +So that's sort of because the +existence of the art show sort + +of explains why the statue +might be there. + +Now, just for fun, I'm going +to switch to another + +situation, very similar. + +And the situation here is that +a neighbor's dog often barks. + +It might be because +of a burglar. + +It might be because +of a raccoon. + +Sometimes, there's a burglar +and a raccoon. + +Sometimes, the damn +dog just barks. + +So let's do some calculations +there and calculate the + +probability that a raccoon +is true, similar to + +what we did last time. + +Looks like on any +given night-- + +it's kind of a wooded are-- +there's a high probability of + +a raccoon showing up. + +And then we can ask, well, what +is the probability of the + +dog barking given that +a raccoon shows up? + +Well, in that case, we want to +just limit the number of rows + +to those where a raccoon-- + +or where the dog is barking. + +Looks like the probability of +the dog barking, knowing + +nothing else, is about +[? 3/7. ?] + +But now we want to know the +probability of the raccoon-- + +that's these guys here +need to get checked. + +These are off. + +So that's the probability +of a raccoon. + +Did I get that right? + +Oh, that's probability +of a burglar. + +Sorry, that was too hard. + +So let me go back +and calculate-- + +I want to get the probability +of a raccoon. + +That's true, false, true, false, +true, false, true. + +So the probability of +a raccoon, as I + +said before is 0.5. + +Now, what happens to that +probability if I know the dog + +is barking? + +Well, all I need to do is limit +my rows to those where + +the dog is barking, +those bottom four. + +And I'll click that there, and +you'll notice all these + +tallies up above the midpoint +have gone to zero, because + +we're only considering +those cases + +where the dog is barking. + +In that case, the probability +that there's a raccoon-- + +just the number of +tallies over the + +total number of tallies-- + +gee, I guess it's 225 plus +50 divided by 370. + +That turns out to be 0.743. + +So about 75% of the time, the +dog barking is accounted for-- + +well, the probability of a +raccoon under those conditions + +is pretty high. + +And now, once again, I'm going +to ask, well, what is the + +probability of a raccoon, given +that the dog is barking + +and there's a burglar? + +Any guess what will +happen there? + +We did this once before +with the statue. + +Probability first went up when +we saw the statue and then + +went down when we saw +another explanation. + +Here's this one here. + +Wow, look at that. + +It went back to its original +condition, its a priori + +probability. + +So somehow, the existence of +the burglar and the dog + +barking means that the +probability of a raccoon is + +just what it was before +we started this game. + +So those are kind of interesting +questions, and + +there's a lot we can do when we +have this table by way of + +those kinds of calculations. + +And in fact, the whole miracle +of probabilistic inference is + +right in front of us. + +It's the table. + +So why don't we go home? + +Well, because there's a little +problem with this table-- + +with these two tables that +I've shown you by way of + +illustration. + +And the problem is that there +are a lot of rows. + +And I had a hard time making +up those numbers. + +I didn't have the patience to +wait and make observations. + +That would take too long. + +So I had to kind of +make some guesses. + +And I could kind of manage +it with eight rows-- + +those up there. + +I could put in some tallies. + +It wasn't that big of a deal. + +So I got myself all those +eight numbers + +up there like that. + +And similarly, for the art show +calculations, produced + +eight numbers. + +But what if I added something +else to the mix? + +What if I added the +day of the week or + +what I had for breakfast? + +Each of those things would +double the number of rows of + +their binary variables. + +So if I have to consider 10 +influences all working + +together, then I'd have +2 to the 10th. + +I'd have 1,000 numbers +to deal with. + +And that would be hard. + +But if I had a joint probability +table, then I can + +do these kinds of miracles. + +But Dave, if I could have this +little projector now, please. + +I just want to emphasize that +although we're talking about + +probabilistic inference, and +it's a very powerful tool, + +it's not the only tool +we need in our bag. + +Trouble with most ideas in +artificial intelligence is + +that their hardcore proponents +think that they're the only + +thing to do. + +And probabilistic inference +has a role to play in + +developing a theory of +human intelligence. + +And it certainly has a practical +value, but it's not + +the only thing. + +And to illustrate that point, +I'd like to imagine for a few + +moments that MIT were founded in +1861 BC instead of 1861 AD. + +And if that were so, then it +might be the case that there + +would be a research program +on what floats. + +And this, of course, would be +a problem in experimental + +physics, and we could imagine +that those people back there + +in that early MIT would, being +experimentally minded, try + +some things. + +Oh, I didn't know that's +what happened. + +It looks like chalk floats. + +Here's a rock. + +No, it didn't float. + +Here's some money. + +Doesn't float. + +Here's a pencil. + +No, it doesn't float. + +Here's a pen. + +Here's a piece of tin foil +I got from Kendra. + +That floats. + +That's a metal. + +The other stuff's metal, too. + +Now I'm really getting +confused. + +Here's a little wad of paper. + +Here's a cell ph-- +no, actually, + +I've tried that before. + +They don't float. + +And they also don't work +afterward, either. + +I don't need to do any of that +in the MIT of 1861 AD and + +beyond, because I know +that Archimedes + +worked this all out. + +And all I have to do is measure +the volume of the + +stuff, divide that by the +weight, and if that ratio is + +big enough, then the +thing will float. + +But back in the old days, I +would have to try a lot of + +stuff and make a big table, +taking into account such + +factors as how hard it is, how +big it is, how heavy it is, + +whether it's alive or not. + +Most things that are +alive float. + +Some don't. + +Fish don't, for instance. + +So it would be foolhardy +to do that. + +That's sort of a probabilistic +inference. + +On the other hand, there are +lots of things where I don't + +know all the stuff I need to +know in order to make the + +calculation. + +I know all the stuff I need to +know in order to decide if + +something floats, but not all +the stuff I need to know in + +order, for example, to decide +if the child of a Republican + +is likely to be a Republican. + +There are a lot of subtle +influences there, and it is + +the case that the children of +Republicans and the children + +of Democrats are more likely to +share the political party + +of their parents. + +But I don't have any direct +way of calculating whether + +that will be true or not. + +All I can do in that case is +what I've done over here, is + +do some measurements, get some +frequencies, take some + +snapshots of the way the world +is and incorporate that into a + +set of probabilities that can +help me determine if any given + +parent is a Republican, given +that I've observed the voting + +behavior their children. + +So probability has a place, +but it's not the + +only tool we need. + +And that is an important +preamble to all the stuff + +we're going to do today. + +Now, we're really through, +because this joint probability + +table is all that there is to +it, except for the fact we + +can't either record all those +numbers, and it becomes + +quickly a pain to +guess at them. + +There are two ways to think +about all this. + +We can think about these +probabilities as probabilities + +that come out of looking +at some data. + +That's a frequentist view +of the probabilities. + +Or we could say, well, we can't +do those measurements. + +So I can just make them up. + +That's sort of the subjective +view of where these + +probabilities come from. + +And in some cases, some people +like to talk about natural + +propensities, like in +quantum mechanics. + +But for our purposes, we either +make them up, or we do + +some tallying. + +Trouble is, we can't deal +with this kind of table. + +So as a consequence of not being +able to deal with this + +kind of table, a gigantic +industry has emerged for + +dealing with probabilities +without the need to work up + +this full table. + +And that's where we're +going to go for + +the rest of the hour. + +And here's the path we're +going to take. + +We're going to talk about some +basic overview of basic + +probability. + +Then we're going to move +ourselves step by step toward + +the so-called belief networks, +which make it possible to make + +this a practical tool. + +So let us begin. + +The first thing is basic +probability. + +Let us say basic. + +And basic probability-- + +all probability flows from +a small number of axioms. + +We have the probability of some +event a has got to be + +greater than 0 and +less than 1. + +That's axiom number one. + +In a binary world, things have +a probability of being true. + +Some have a probability +of being false. + +But the true event doesn't have +any possibility of being + +anything other than true, so +the probability of true is + +equal to 1, and the probability +of false-- + +the false event, the +false condition-- + +has no possibility of being +true, so that's 0. + +Then the third of the axioms +of probability is that the + +probability of a plus the +probability of b minus the + +probability of a and +b is equal to the + +probability of a or b. + +Yeah, that makes sense, right? + +I guess it would make more sense +if I didn't switch my + +notation in midstream-- + +a and b. + +So those are the axioms that +mathematicians love to start + +up that way, and they can derive +everything there is to + +derive from that. + +But I never can deal with +stuff that way. + +I have to draw a picture and +think of this stuff in a more + +intuitionist type of way. + +So that's the formal approach +to dealing with probability, + +and it's mirrored by intuitions +that have to do + +with discussions of spaces, +like so, in which we have + +circles, or areas, representing +a and b. + +And to keep my notation +consistent, + +I'll make those lowercase. + +So you can think of those as +spaces of all possible worlds + +in which these things +might occur. + +Or you can think of them +as sample spaces. + +But in any event, you associate +with the probability + +of a the size of this area here +relative to the total + +area in the rectangle-- + +the universe. + +So the probability of a is the +size of this circle divided by + +the size of this rectangle +in this picture. + +So now all these axioms +make sense. + +The probability that a is +certain is just when that + +fills up the whole thing, and +there's no other place for a + +sample to be, that means +it has to be a. + +So that probability goes +all the way up to 1. + +On the other hand, if the size +of a is just an infinitesimal + +dot, then the chances of landing +in that world is 0. + +That's the bound on +the other end. + +So this-- + +axiom number one-- makes +sense in terms of that + +picture over there. + +Likewise, axiom number two. + +What about axiom number three? + +Does that make sense in terms +of all this stuff? + +And the answer is, sure, because +we can just look at + +those areas with a little +bit of colored chalk. + +And so the probability of a +is just this area here. + +The probability of b +is this area here. + +And if we want to know the +probability that we're in + +either a or b, then we just have +to add up those areas. + +But when we add up those areas, +this intersection part + +is added in twice. + +So we've got to subtract that +off in order to make this + +thing make a rational equation, +so that makes sense. + +And axiom three makes +sense, just as + +axioms one and two did. + +So that's all there is +to basic probability. + +And now you could do all sorts +of algebra on that, and it's + +elegant, because it's like +circuit theory or + +electromagnetism, because +from a very + +small number of axioms-- + +in this case three-- + +you can build an elegant +mathematical system. + +And that's what probability +subjects do. + +But we're not going to go there, +because we're sort of + +focused on getting down to a +point where we can deal with + +that joint probability +table that we + +currently can't deal with. + +So we're not going to go into +a whole lot of algebra with + +these things. + +Just what we need in order to +go through that network. + +So the next thing we need to +deal with is conditional + +probability. + +And whereas those are axioms, +this is a definition. + +We say that the probability of +a given b is equal to, by + +definition, the probability +of a and b. + +I'm using that common notation +to mean [INAUDIBLE] + +as is conventional +in the field. + +And then we're going to divide +that by the probability of B. + +You can take that as a +definition, and then it's just + +a little bit of mysterious +algebra. + +Or you could do like we did up +there and take an intuitionist + +approach and ask what that +stuff means in terms of a + +circle diagram and some +sort of space. + +And let's see, what +does that mean? + +It means that we're trying to +restrict the probability of a + +to those circumstances where +b is known to be so. + +And we're going to say that-- + +we've got this part here, +and then we've got the + +intersection of a with b. + +And so it does make sense as a +definition, because it says + +that if you've got b, then the +probability that you're going + +to get a is the size of +that intersection-- + +the pink and orange stuff-- + +divided by the whole of b. + +So it's as if we restricted the +universe of consideration + +to just that part of the +original universe + +as covered by b. + +So that makes sense +as a definition. + +And we can rewrite that, of +course, as P of a and b is + +equal to the probability +of a given b times the + +probability of b. + +That's all basic stuff. + +Now, we do want to do a little +bit of algebra here, because I + +want to consider not just two +cases, but what if we divide + +this space up into +three parts? + +Then we'll say that the +probability of a, b, and c is + +equal to what? + +Well, there are lots of ways +to think about that. + +But one way to think about it is +that we are restricting the + +universe to that part +of the world where b + +and c are both true. + +So let's say that y is +equal to b and c-- + +the intersection of b and c, +where a and b are both true. + +Then we can use this formula +over here to say that + +probability of a, b, and c is +equal to the probability of a + +and y, which is equal to the +probability of a given y times + +the probability of y. + +And then we can expand that back +out and say that P of a + +given b and c is equal +to the probability-- + +sorry, times the probability +of y, but y is equal to the + +probability of b +and c, like so. + +Ah, but wait-- + +we can run this idea over that +one, too, and we can say that + +this whole works is equal to the +probability of a given b + +and c times the probability +of b given c times the + +probability of c. + +And now, when we stand back and +let that sing to us, we + +can see that some magic is +beginning to happen here, + +because we've taken this +probability of all things + +being so, and we've broken up +into a product of three + +probabilities. + +The first two are conditional +probabilities, so they're + +really all conditional +probabilities. + +The last one's conditional +on nothing. + +But look what happens as we +go from left to right. + +a is dependent on two things. + +b is only dependent on one thing +and nothing to the left. + +c is dependent on nothing +and nothing to the left. + +So you can sense a +generalization coming. + +So let's write it down. + +So let's go from here over +to here and say that the + +probability of a whole +bunch of things-- + +x1 through x10-- + +is equal to some product +of probabilities. + +We'll let the index +i run from n to 1. + +Probability of x to the last one +in the series, conditioned + +on all the other ones-- + +sorry, that's probability +of i, i minus 1 + +down to x1 like so. + +And for the first one in this +product, i will be equal to n. + +For the second one, i will +be equal to n minus 1. + +But you'll notice that as I +go from n toward 1, these + +conditionals get smaller-- + +the number of things on +condition get smaller, and + +none of these things +are on the left. + +They're only stuff that +I have on the right. + +So what I mean to say is all of +these things have an index + +that's smaller than +this index. + +None of the ones that have a +higher index are appearing in + +that conditional. + +So it's a way of taking a +probability of the end of a + +whole bunch of things and +writing it as a product of + +conditional probabilities. + +So we're making good progress. + +We've done one. + +We've done two. + +And now we've done three, +because this + +is the chain rule. + +And we're about halfway through +our diagram, halfway + +to the point where we can +do something fun. + +But we still have a couple more +concepts to deal with, + +and the next concept is the +concept of conditional + +probability. + +So that's all this +stuff up here-- + +oops. + +All this stuff here is the +definition of conditional + +probability. + +And now I want to go to the +definition of independence. + +So that's another definitional +deal. + +But it's another definitional +deal that makes some sense + +with a diagram as well. + +So the definition +goes like this. + +We say that P of a given b +is equal to P of a if a + +independent of b. + +So that says that the +probability of a doesn't + +depend on what's going +on with b. + +It's the same either way. + +So it's independent. + +b doesn't matter. + +So what does that look like +if we try to do an + +intuitionist diagram? + +Well, let's see. + +Here's a. + +Here's b. + +Now, the probability +of a given b-- + +well, let's see. + +That must be this part here +divided by this part here. + +So the ratio of those areas is +the probability of a given b. + +So that's the probability of +this way divided by the + +probability of both ways. + +So what's the probability of +a in terms of these areas? + +Well, probability of a in terms +of these areas is the + +probability-- + +let's see, have I +got this right? + +I've got this upside down. + +The probability of a given b +is the probability of the + +stuff in the intersection-- + +so that's both ways-- + +divided by the probability +of the stuff in b, which + +is going this way. + +And let's see, the probability +of a not conditioned on + +anything except being in this +universe is all these hash + +marks, like so, divided +by the universe. + +So when we say that something's +independent, it + +means that those two ratios +are the same. + +That's all it means in the +intuitionist's point of view. + +So it says that this little +area here divided by this + +whole area is the same as this +whole area for a divided by + +the size of the universe. + +So that's what independence +means. + +Now, that's quite +a lot of work. + +But we're not done with +independence, because we've + +got conditional independence +to deal with. + +And that, too, can be viewed +as a definition. + +And what we're going to say is +that the probability of a + +given b and z is equal to the +probability of a given z. + +What's that mean? + +That means that if you know +that we're dealing with z, + +then the probability of +a doesn't depend on b. + +b doesn't matter anymore +once you're + +restricted to being in z. + +So you can look at +that this way. + +Here's a, and here's +b, and here is z. + +So what we're saying is that +we're restricting the world to + +being in this part of the +universe where z is. + +So the probability of a given b +and z is this piece in here. + +a given b and z is +that part there. + +And the probability of a given +z is this part here + +divided by all of z. + +So we're saying that the ratio +of this little piece here to + +this part, which I'll mark that +way, ratio of this to + +this is the same as the +ratio of that to that. + +So that's conditional +independence. + +So you can infer from these +things, with a little bit of + +algebra, that P of a and b given +z is equal to P of a + +given z times P of b in z. + +Boy, that's been quite a +journey, but we got all the + +way through one, two, three, +four, and five. + +And now the next thing is belief +nets, and I'm going to + +ask you to forget everything +I've said for a minute or two. + +And we'll come back to it. + +I want to talk about the dog +and the burglar and the + +raccoon again. + +And now, forgetting about +probability, I can say, look, + +the dog barks if a +raccoon shows up. + +The dog barks if a +burglar shows up. + +A burglar doesn't show up +because the dog is barking. + +A raccoon doesn't show up +because the dog is barking. + +So the causality flows from the +burglar and the raccoon to + +the barking. + +So we can make a diagram +of that. + +And our diagram will +look like this. + +Here is the burglar, and +here is the raccoon. + +And these have causal relations +to the dog barking. + +So that's an interesting idea, +because now I can say that-- + +well, I can't say anything yet, +because I want to add a + +little more complexity to it. + +I'm going to add two +more variables. + +You might call the police, +depending on how vigorous the + +dog is barking, I guess. + +And the raccoon has a propensity +to knocking over + +the trash can. + +So now, I've got +five variables. + +How big a joint probability +table am I going to need to + +keep my tallies straight? + +Well, it'll be 2 to the 5th. + +That's 32. + +But what I'm going to say is +that this diagram is a + +statement, that every node in it +depends on its parents and + +nothing else that's +not a descendant. + +Now, I need to say that about +50 times, because you've got + +to say it right. + +Every node there is independent +of every + +non-descendant other +then its parents. + +No, that's not quite right. + +Given its parents, every node +is independent of all other + +non-descendants. + +Well, what does that mean? + +Here's the deal with +calling the police. + +Here's its one and +only parent. + +So given this parent, the +probability that they were + +going to call the police doesn't +depend on anything + +like B, R, or T. It's because +all of the causality is + +flowing through this +dog barking. + +I'm not going to call the +police in a way that's + +dependent on anything else other +than whether the dog is + +barking or not. + +Because this guy has this as +a parent, and these are not + +descendants of calling the +police, so this is independent + +of B, R, and T. + +So let's go walk through +the others. + +Here's the dog. + +The dog's parents are burger + +appearing and raccoon appearing. + +So the probability that the dog +appears is independent of + +that trash can over there, +because that's not a + +descendant. + +It is dependent on +these parents. + +How about the trash can? + +It depends only on +the raccoon. + +It doesn't depend on any other +non-descendant, so therefore, + +it doesn't depend on D, +B, or P. How about B? + +It has no parents. + +So it depends on nothing else, +because everything else is + +either a non-descendant, because +B does not dependent + +on R and T, because they're +not descendants. + +It's interesting that B might +depend on D and P, because + +those are descendants. + +So it's important to understand +that there's this + +business of independence given +the parents of all other + +non-descendants. + +And you'll see why that funny, +strange language is important + +in a minute. + +But now, let's see-- + +I want to make a model of what's +going to happen here. + +So let me see what kind of +probabilities I'm going to + +have to figure out. + +This guy doesn't depend +on anything upstream. + +So we could just say that +all we need there is the + +probability that a burglar +is going to appear. + +Let's say it's a fairly +high-crime neighborhood-- + +1 chance in 10-- + +1 day in 10, a burglar +appears. + +The raccoon doesn't depend on +anything other than its own + +propensity, so its probability, + +we'll say, is 0.5. + +Raccoons love the place, so it +shows up about 1 day in 2. + +So what about the dog barking? + +That depends on whether there's +a burglar, and the + +other parent is whether +there's a raccoon. + +So we need to keep track of the +probability that the dog + +will bark for all four +combinations. + +So this will be the burglar, and +this will be the raccoon. + +This will be false, false, +true, true-- + +oops-- false, false, +true, false, + +false, true, true, true. + +So let's say it's a wonderful +dog, and it always barks if + +there's a burglar. + +So that would say that the +probability here is 1.0, and + +the probability here is 1.0. + +And if there's neither a burglar +nor a raccoon, the dog + +still likes to bark +just for fun. + +So we'll say that's a +chance of 1 in 10. + +And then in case there's a +burglar, let's say this. + +There's no burglar, but +there is a raccoon-- + +he's tired of the raccoons, so +he only barks half the time. + +Do these numbers, by the way, +have to add up to 1? + +They clearly don't. + +These numbers don't +add up to one. + +What adds up to 1 is this +is the probability + +that the dog barks. + +And then the other phantom +probability is out here. + +And these have to add up to 1. + +So that would be 0.9, that would +be 0.0, that would be + +0.5, and this would be 0.0. + +So because those are just 1 +minus the numbers in these + +columns, I don't bother +to write them down. + +Well, we still have a couple +more things to do. + +The probability that we'll call +the police depends only + +on the dog. + +So we'll have a column for the +dog, and then we'll have a + +probability of calling +the police. + +There's a probability for that +being false and a probability + +for that being true. + +So if the dog doesn't bark, +there's really hardly any + +chance we'll call the police. + +So make that 0, 0, 1. + +If the dog is barking, if he +barks vigorously enough, maybe + +1 chance in 10. + +Here, we have the trash can-- +the final thing we have to + +think about. + +There's the trash can; +rather, the raccoon. + +And here's the trash +can probability. + +Depends on the raccoon being +either present or not present. + +If the raccoon is not present, +the probability the trash can + +is knocked over by, say, +the wind is 1 in 1,000. + +If the raccoon is there, oh man, +that guy always likes to + +go in there, so that's 0.8. + +So now I'm done specifying +this model. + +And the question is, how many +numbers did I have to specify? + +Well, let's see. + +I have to specify that one, that +one, that one, that one, + +that one, that one-- that's +6, 7, 8, 9, 10. + +So I had to specify +10 numbers. + +If I just try to build myself +a joint probability table + +straightaway, how many numbers +would I have to supply? + +Well, it's 2 to the n. + +So it's 2 to the +5th, that's 32. + +Considerable saving. + +By the way, how do you suppose +I made that table? + +Not by doing all +those numbers. + +By making this belief network +and then using the belief + +network to calculate +those numbers. + +And that's why this is a +miracle, because with these + +numbers, I can calculate those +numbers instead of making them + +up or making a whole lot of +tally-type measurements. + +So I'd like to make sure +that that's true. + +And I can use this stuff here +to calculate the full joint + +probability table. + +So here's how this works. + +I have the probability +of some combination-- + +let's say the police, the dog, +the burglar, the trash can, + +and the raccoon. + +All the combinations that are +possible there will give me an + +entry in the table-- one row. + +But let's see-- + +there's some miracle here. + +Oh, this chain rule. + +Let's use the chain rule. + +We can write that as a +probability that we call the + +police given d, b, t, and r. + +And then the next one in my +chain is probability of d + +given b, t, and r. + +Then the next one in the chain +is the probability of + +b given t and r. + +And the next one in my chain +is P of t given r. + +And the final one in +my chain is p of r. + +Now, we have some conditional +independence + +knowledge, too, don't we? + +We know that this probability +here depends only on d because + +there are no descendants. + +So therefore, we don't have to +think about that, and all the + +numbers we need here are +produced by this table. + +How about this one here? + +Probability that the dog barks +depends only on its parents, b + +and r, so it doesn't +depend on t. + +So b, in turn, depends on-- + +what does it depend on? + +It doesn't depend on anything. + +So we can scratch those. + +Probability of t given r, yeah, +there's a probability + +there, but we can get +that from the table. + +And finally, P or r. + +So that's why I went through +all that probability junk, + +because if we arrange things in +the expansion of this, from + +bottom to top, then we arrange +things so that none of these + +guys depends on a descendant +in this formula. + +And we have a limited number +of things that it + +depends on above it. + +So that's the way we can +calculate back the full joint + +probability table. + +And that brings us to the end +of the discussion today. + +But the thing we're going to +think about is, how much + +saving do we really +get out of this? + +In this particular case, we +only had to devise 10 + +numbers out of 32. + +What if we had 10 properties +or 100 properties? + +How much saving would +we get then? + +That's what we'll take +up next time, + +after the quiz on Wednesday. \ No newline at end of file diff --git a/Ayvwr28VKBk.txt b/Ayvwr28VKBk.txt new file mode 100644 index 0000000000000000000000000000000000000000..02262dba5c683c82889a9da2d89fadb56cee39bd --- /dev/null +++ b/Ayvwr28VKBk.txt @@ -0,0 +1,14643 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT OpenCourseWare continue to + + align:start position:0% +will help MIT OpenCourseWare continue to + + + align:start position:0% +will help MIT OpenCourseWare continue to +offer high quality educational resources + + align:start position:0% +offer high quality educational resources + + + align:start position:0% +offer high quality educational resources +for free + + align:start position:0% +for free + + + align:start position:0% +for free +to make a donation or to view additional + + align:start position:0% +to make a donation or to view additional + + + align:start position:0% +to make a donation or to view additional +materials from hundreds of MIT courses + + align:start position:0% +materials from hundreds of MIT courses + + + align:start position:0% +materials from hundreds of MIT courses +visit MIT opencourseware at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +all right let's jump ahead here let me + + align:start position:0% +all right let's jump ahead here let me + + + align:start position:0% +all right let's jump ahead here let me +talk a little bit about manufacturing in + + align:start position:0% +talk a little bit about manufacturing in + + + align:start position:0% +talk a little bit about manufacturing in +general and the competitive challenged + + align:start position:0% +general and the competitive challenged + + + align:start position:0% +general and the competitive challenged +us manufacturers of the 1990s + + align:start position:0% +us manufacturers of the 1990s + + + align:start position:0% +us manufacturers of the 1990s +manufacturing moves 30% of US economic + + align:start position:0% +manufacturing moves 30% of US economic + + + align:start position:0% +manufacturing moves 30% of US economic +growth it had men fight ran two times + + align:start position:0% +growth it had men fight ran two times + + + align:start position:0% +growth it had men fight ran two times +the productivity level of the services + + align:start position:0% +the productivity level of the services + + + align:start position:0% +the productivity level of the services +so manufacture almost invariably has a + + align:start position:0% +so manufacture almost invariably has a + + + align:start position:0% +so manufacture almost invariably has a +much higher productivity level than a + + align:start position:0% +much higher productivity level than a + + + align:start position:0% +much higher productivity level than a +service us 80% services so if you really + + align:start position:0% +service us 80% services so if you really + + + align:start position:0% +service us 80% services so if you really +want a high productivity growth and a + + align:start position:0% +want a high productivity growth and a + + + align:start position:0% +want a high productivity growth and a +factory is a way of scaling who is an + + align:start position:0% +factory is a way of scaling who is an + + + align:start position:0% +factory is a way of scaling who is an +effect product quickly service sector + + align:start position:0% +effect product quickly service sector + + + align:start position:0% +effect product quickly service sector +scale much more slowly has little more + + align:start position:0% +scale much more slowly has little more + + + align:start position:0% +scale much more slowly has little more +face to face so you probably want a + + align:start position:0% +face to face so you probably want a + + + align:start position:0% +face to face so you probably want a +significant component of your economy in + + align:start position:0% +significant component of your economy in + + + align:start position:0% +significant component of your economy in +something that scales three and it + + align:start position:0% +something that scales three and it + + + align:start position:0% +something that scales three and it +introduces productivity effectively and + + align:start position:0% +introduces productivity effectively and + + + align:start position:0% +introduces productivity effectively and +that tends to be manufactured so + + align:start position:0% +that tends to be manufactured so + + + align:start position:0% +that tends to be manufactured so +manufacturing is also traditionally and + + align:start position:0% +manufacturing is also traditionally and + + + align:start position:0% +manufacturing is also traditionally and +I are paying jobs in 2001 there were 23 + + align:start position:0% +I are paying jobs in 2001 there were 23 + + + align:start position:0% +I are paying jobs in 2001 there were 23 +percent higher than the services sector + + align:start position:0% +percent higher than the services sector + + + align:start position:0% +percent higher than the services sector +the ratio is not all that different + + align:start position:0% +the ratio is not all that different + + + align:start position:0% +the ratio is not all that different +today + + align:start position:0% +today + + + align:start position:0% +today +so it's manufacturing is an important + + align:start position:0% +so it's manufacturing is an important + + + align:start position:0% +so it's manufacturing is an important +part of you as it coming to be it's + + align:start position:0% +part of you as it coming to be it's + + + align:start position:0% +part of you as it coming to be it's +about 12% of GDP and it's it funds + + align:start position:0% +about 12% of GDP and it's it funds + + + align:start position:0% +about 12% of GDP and it's it funds +two-thirds industrial rd in funds + + align:start position:0% +two-thirds industrial rd in funds + + + align:start position:0% +two-thirds industrial rd in funds +three-quarters of industrial research + + align:start position:0% +three-quarters of industrial research + + + align:start position:0% +three-quarters of industrial research +development and about two-thirds of over + + align:start position:0% +development and about two-thirds of over + + + align:start position:0% +development and about two-thirds of over +you overall US army and manufacturing + + align:start position:0% +you overall US army and manufacturing + + + align:start position:0% +you overall US army and manufacturing +firms account for a greater percentage + + align:start position:0% +firms account for a greater percentage + + + align:start position:0% +firms account for a greater percentage +of real GDP than all these other kinds + + align:start position:0% +of real GDP than all these other kinds + + + align:start position:0% +of real GDP than all these other kinds +of cycles right so it remains a very + + align:start position:0% +of cycles right so it remains a very + + + align:start position:0% +of cycles right so it remains a very +significant player but it's also big + + align:start position:0% +significant player but it's also big + + + align:start position:0% +significant player but it's also big +enabler from the other sectors so + + align:start position:0% +enabler from the other sectors so + + + align:start position:0% +enabler from the other sectors so +manufacturing jobs and there's a lot of + + align:start position:0% +manufacturing jobs and there's a lot of + + + align:start position:0% +manufacturing jobs and there's a lot of +debate as to what the multiplier is a + + align:start position:0% +debate as to what the multiplier is a + + + align:start position:0% +debate as to what the multiplier is a +difference differs from sector to sector + + align:start position:0% +difference differs from sector to sector + + + align:start position:0% +difference differs from sector to sector +but it is the biggest job multiplying in + + align:start position:0% +but it is the biggest job multiplying in + + + align:start position:0% +but it is the biggest job multiplying in +our economy in other words a + + align:start position:0% +our economy in other words a + + + align:start position:0% +our economy in other words a +manufacturing job tends to create + + align:start position:0% +manufacturing job tends to create + + + align:start position:0% +manufacturing job tends to create +additional employment to be kind of + + align:start position:0% +additional employment to be kind of + + + align:start position:0% +additional employment to be kind of +value chains that is connected in a + + align:start position:0% +value chains that is connected in a + + + align:start position:0% +value chains that is connected in a +services sector and supplier sector + + align:start position:0% + + + + align:start position:0% + +so the US has been running frightening + + align:start position:0% +so the US has been running frightening + + + align:start position:0% +so the US has been running frightening +trade deficits in that effective goods + + align:start position:0% +trade deficits in that effective goods + + + align:start position:0% +trade deficits in that effective goods +for a significant period of time right + + align:start position:0% +for a significant period of time right + + + align:start position:0% +for a significant period of time right +and it began under President Nixon and + + align:start position:0% +and it began under President Nixon and + + + align:start position:0% +and it began under President Nixon and +has continued to grow since then the + + align:start position:0% +has continued to grow since then the + + + align:start position:0% +has continued to grow since then the +most problematic number is the trade + + align:start position:0% +most problematic number is the trade + + + align:start position:0% +most problematic number is the trade +deficit the US has in advanced + + align:start position:0% +deficit the US has in advanced + + + align:start position:0% +deficit the US has in advanced +manufacturing this no it's complete + + align:start position:0% +manufacturing this no it's complete + + + align:start position:0% +manufacturing this no it's complete +sight value goods the u.s. is running a + + align:start position:0% +sight value goods the u.s. is running a + + + align:start position:0% +sight value goods the u.s. is running a +hundred billion dollar trade deficit in + + align:start position:0% +hundred billion dollar trade deficit in + + + align:start position:0% +hundred billion dollar trade deficit in +those goods so the theory that weed seed + + align:start position:0% +those goods so the theory that weed seed + + + align:start position:0% +those goods so the theory that weed seed +low-end production but make it up by + + align:start position:0% +low-end production but make it up by + + + align:start position:0% +low-end production but make it up by +retaining I n production it's not + + align:start position:0% +retaining I n production it's not + + + align:start position:0% +retaining I n production it's not +working and manufacturing job loss you + + align:start position:0% +working and manufacturing job loss you + + + align:start position:0% +working and manufacturing job loss you +know has a pretty painful history 2.7 + + align:start position:0% +know has a pretty painful history 2.7 + + + align:start position:0% +know has a pretty painful history 2.7 +million jobs were lost in that 2002-2003 + + align:start position:0% +million jobs were lost in that 2002-2003 + + + align:start position:0% +million jobs were lost in that 2002-2003 +recession five point eight million jobs + + align:start position:0% +recession five point eight million jobs + + + align:start position:0% +recession five point eight million jobs +between 2000 2010 the majority of those + + align:start position:0% +between 2000 2010 the majority of those + + + align:start position:0% +between 2000 2010 the majority of those +focused on that 2008 recession in that + + align:start position:0% +focused on that 2008 recession in that + + + align:start position:0% +focused on that 2008 recession in that +2000 and 2010 timetable we shut down + + align:start position:0% +2000 and 2010 timetable we shut down + + + align:start position:0% +2000 and 2010 timetable we shut down +about 62,000 factories net the US has + + align:start position:0% +about 62,000 factories net the US has + + + align:start position:0% +about 62,000 factories net the US has +been moving its percentage of + + align:start position:0% +been moving its percentage of + + + align:start position:0% +been moving its percentage of +manufacturing employment ever downward + + align:start position:0% +manufacturing employment ever downward + + + align:start position:0% +manufacturing employment ever downward +so worried about 8 percent of US + + align:start position:0% +so worried about 8 percent of US + + + align:start position:0% +so worried about 8 percent of US +employment is the manufacturing sector + + align:start position:0% +employment is the manufacturing sector + + + align:start position:0% +employment is the manufacturing sector +other countries don't do that + + align:start position:0% +other countries don't do that + + + align:start position:0% +other countries don't do that +so Germany employs about 20 percent of + + align:start position:0% +so Germany employs about 20 percent of + + + align:start position:0% +so Germany employs about 20 percent of +its workforce in manufacturing Italy 19 + + align:start position:0% +its workforce in manufacturing Italy 19 + + + align:start position:0% +its workforce in manufacturing Italy 19 +Japan 22 South Korea 31 in other words + + align:start position:0% +Japan 22 South Korea 31 in other words + + + align:start position:0% +Japan 22 South Korea 31 in other words +other country you know it's + + align:start position:0% +other country you know it's + + + align:start position:0% +other country you know it's +manufacturing as a source of higher + + align:start position:0% +manufacturing as a source of higher + + + align:start position:0% +manufacturing as a source of higher +wages and it's a job multiplier right + + align:start position:0% +wages and it's a job multiplier right + + + align:start position:0% +wages and it's a job multiplier right +you can kind of see some of the + + align:start position:0% +you can kind of see some of the + + + align:start position:0% +you can kind of see some of the +potential competitive advantages for + + align:start position:0% +potential competitive advantages for + + + align:start position:0% +potential competitive advantages for +retaining a substantial make sure the + + align:start position:0% +retaining a substantial make sure the + + + align:start position:0% +retaining a substantial make sure the +search so those are kind of background + + align:start position:0% +search so those are kind of background + + + align:start position:0% +search so those are kind of background +points let me do a couple of pieces now + + align:start position:0% +points let me do a couple of pieces now + + + align:start position:0% +points let me do a couple of pieces now +I'll do Glen long and Lynn sue Kim + + align:start position:0% +I'll do Glen long and Lynn sue Kim + + + align:start position:0% +I'll do Glen long and Lynn sue Kim +so when teaches at Thunderbird in + + align:start position:0% +so when teaches at Thunderbird in + + + align:start position:0% +so when teaches at Thunderbird in +Arizona + + align:start position:0% +Arizona + + + align:start position:0% +Arizona +which is + + align:start position:0% +which is + + + align:start position:0% +which is +find school for International Business + + align:start position:0% +find school for International Business + + + align:start position:0% +find school for International Business +and he wrote a piece in 98 about what + + align:start position:0% +and he wrote a piece in 98 about what + + + align:start position:0% +and he wrote a piece in 98 about what +was happening in Japan so in that time + + align:start position:0% +was happening in Japan so in that time + + + align:start position:0% +was happening in Japan so in that time +so Japan is on a complete take off as a + + align:start position:0% +so Japan is on a complete take off as a + + + align:start position:0% +so Japan is on a complete take off as a +leading world economy until the 1990 + + align:start position:0% +leading world economy until the 1990 + + + align:start position:0% +leading world economy until the 1990 +timeframe and then it misses the IT + + align:start position:0% +timeframe and then it misses the IT + + + align:start position:0% +timeframe and then it misses the IT +Innovation Lab as we discussed earlier + + align:start position:0% +Innovation Lab as we discussed earlier + + + align:start position:0% +Innovation Lab as we discussed earlier +and it starts to have to reorganize its + + align:start position:0% +and it starts to have to reorganize its + + + align:start position:0% +and it starts to have to reorganize its +and rethink its innovation system so + + align:start position:0% +and rethink its innovation system so + + + align:start position:0% +and rethink its innovation system so +Glenn argues that there were essentially + + align:start position:0% +Glenn argues that there were essentially + + + align:start position:0% +Glenn argues that there were essentially +three historical stages to contain + + align:start position:0% +three historical stages to contain + + + align:start position:0% +three historical stages to contain +japan's competitive pattern so first it + + align:start position:0% +japan's competitive pattern so first it + + + align:start position:0% +japan's competitive pattern so first it +was the pursuer after the plan here with + + align:start position:0% +was the pursuer after the plan here with + + + align:start position:0% +was the pursuer after the plan here with +us being the kind of innovation plan in + + align:start position:0% +us being the kind of innovation plan in + + + align:start position:0% +us being the kind of innovation plan in +there then it's a follower right at the + + align:start position:0% +there then it's a follower right at the + + + align:start position:0% +there then it's a follower right at the +frontier with us and then it becomes a + + align:start position:0% +frontier with us and then it becomes a + + + align:start position:0% +frontier with us and then it becomes a +world-class competitor and he argues + + align:start position:0% +world-class competitor and he argues + + + align:start position:0% +world-class competitor and he argues +that as Japan became a world-class + + align:start position:0% +that as Japan became a world-class + + + align:start position:0% +that as Japan became a world-class +competitor and had to rethink its more + + align:start position:0% +competitor and had to rethink its more + + + align:start position:0% +competitor and had to rethink its more +centralized organization with its + + align:start position:0% +centralized organization with its + + + align:start position:0% +centralized organization with its +innovations so the old thesis about + + align:start position:0% +innovations so the old thesis about + + + align:start position:0% +innovations so the old thesis about +Japan Glenn argues is that it was + + align:start position:0% +Japan Glenn argues is that it was + + + align:start position:0% +Japan Glenn argues is that it was +focused on national industrial + + align:start position:0% +focused on national industrial + + + align:start position:0% +focused on national industrial +performance and a corresponding + + align:start position:0% +performance and a corresponding + + + align:start position:0% +performance and a corresponding +competitive balance between nations + + align:start position:0% +competitive balance between nations + + + align:start position:0% +competitive balance between nations +based on national industrial components + + align:start position:0% +based on national industrial components + + + align:start position:0% +based on national industrial components +and it was set by you know political + + align:start position:0% +and it was set by you know political + + + align:start position:0% +and it was set by you know political +economies really operating at the + + align:start position:0% +economies really operating at the + + + align:start position:0% +economies really operating at the +national scale event at the governmental + + align:start position:0% +national scale event at the governmental + + + align:start position:0% +national scale event at the governmental +kind of Steel is strong governmental + + align:start position:0% +kind of Steel is strong governmental + + + align:start position:0% +kind of Steel is strong governmental +role but then a more pragmatic kind of + + align:start position:0% +role but then a more pragmatic kind of + + + align:start position:0% +role but then a more pragmatic kind of +approach matter of law so meaty which I + + align:start position:0% +approach matter of law so meaty which I + + + align:start position:0% +approach matter of law so meaty which I +mentioned earlier was the key organizing + + align:start position:0% +mentioned earlier was the key organizing + + + align:start position:0% +mentioned earlier was the key organizing +institution around getting collaboration + + align:start position:0% +institution around getting collaboration + + + align:start position:0% +institution around getting collaboration +from government industry and setting + + align:start position:0% +from government industry and setting + + + align:start position:0% +from government industry and setting +industry agendas in Japan in its older + + align:start position:0% +industry agendas in Japan in its older + + + align:start position:0% +industry agendas in Japan in its older +period you know it would set technology + + align:start position:0% +period you know it would set technology + + + align:start position:0% +period you know it would set technology +initiatives that were selected by + + align:start position:0% +initiatives that were selected by + + + align:start position:0% +initiatives that were selected by +high-level governmental leaders + + align:start position:0% +high-level governmental leaders + + + align:start position:0% +high-level governmental leaders +including it immediately and then in a + + align:start position:0% +including it immediately and then in a + + + align:start position:0% +including it immediately and then in a +more recent period it's had to move + + align:start position:0% +more recent period it's had to move + + + align:start position:0% +more recent period it's had to move +or is technology initiatives they're + + align:start position:0% +or is technology initiatives they're + + + align:start position:0% +or is technology initiatives they're +really selectively industry in other + + align:start position:0% +really selectively industry in other + + + align:start position:0% +really selectively industry in other +words it's reached it at the frontier + + align:start position:0% +words it's reached it at the frontier + + + align:start position:0% +words it's reached it at the frontier +the ability of government to pick the + + align:start position:0% +the ability of government to pick the + + + align:start position:0% +the ability of government to pick the +technology menu becomes more problematic + + align:start position:0% +technology menu becomes more problematic + + + align:start position:0% +technology menu becomes more problematic +you've got to get that down to industry + + align:start position:0% +you've got to get that down to industry + + + align:start position:0% +you've got to get that down to industry +decision-makers that are much closer to + + align:start position:0% +decision-makers that are much closer to + + + align:start position:0% +decision-makers that are much closer to +markets and much less of the innovation + + align:start position:0% +markets and much less of the innovation + + + align:start position:0% +markets and much less of the innovation +system itself and that has evolved in + + align:start position:0% +system itself and that has evolved in + + + align:start position:0% +system itself and that has evolved in +Japan that high officials just can't + + align:start position:0% +Japan that high officials just can't + + + align:start position:0% +Japan that high officials just can't +keep an eye on the rapidly evolving + + align:start position:0% +keep an eye on the rapidly evolving + + + align:start position:0% +keep an eye on the rapidly evolving +critics technologies so that's kind of + + align:start position:0% +critics technologies so that's kind of + + + align:start position:0% +critics technologies so that's kind of +technology initiatives then there was + + align:start position:0% +technology initiatives then there was + + + align:start position:0% +technology initiatives then there was +technology targeting in the old period + + align:start position:0% +technology targeting in the old period + + + align:start position:0% +technology targeting in the old period +there was direct government targeting of + + align:start position:0% +there was direct government targeting of + + + align:start position:0% +there was direct government targeting of +one or two specific technologies right + + align:start position:0% +one or two specific technologies right + + + align:start position:0% +one or two specific technologies right +that we're going to be pursued by the + + align:start position:0% +that we're going to be pursued by the + + + align:start position:0% +that we're going to be pursued by the +government and the funding was a you + + align:start position:0% +government and the funding was a you + + + align:start position:0% +government and the funding was a you +know at the late development stages + + align:start position:0% +know at the late development stages + + + align:start position:0% +know at the late development stages +right the government funding was focused + + align:start position:0% +right the government funding was focused + + + align:start position:0% +right the government funding was focused +really on advanced prototyping and + + align:start position:0% +really on advanced prototyping and + + + align:start position:0% +really on advanced prototyping and +engineering development that's what the + + align:start position:0% +engineering development that's what the + + + align:start position:0% +engineering development that's what the +government support was going in the + + align:start position:0% +government support was going in the + + + align:start position:0% +government support was going in the +newer period Japan shifted towards more + + align:start position:0% +newer period Japan shifted towards more + + + align:start position:0% +newer period Japan shifted towards more +fundamental research money and along + + align:start position:0% +fundamental research money and along + + + align:start position:0% +fundamental research money and along +with it supplied and put to put a + + align:start position:0% +with it supplied and put to put a + + + align:start position:0% +with it supplied and put to put a +broader range of technology alternatives + + align:start position:0% +broader range of technology alternatives + + + align:start position:0% +broader range of technology alternatives +onto the table as Glenn characterizes it + + align:start position:0% +onto the table as Glenn characterizes it + + + align:start position:0% +onto the table as Glenn characterizes it +moved to a kind of shotgun approach not + + align:start position:0% +moved to a kind of shotgun approach not + + + align:start position:0% +moved to a kind of shotgun approach not +a kind of more narrow rifle shot and + + align:start position:0% +a kind of more narrow rifle shot and + + + align:start position:0% +a kind of more narrow rifle shot and +then finally industry targeting in the + + align:start position:0% +then finally industry targeting in the + + + align:start position:0% +then finally industry targeting in the +older period meanie would actually pick + + align:start position:0% +older period meanie would actually pick + + + align:start position:0% +older period meanie would actually pick +winning companies it would decide who's + + align:start position:0% +winning companies it would decide who's + + + align:start position:0% +winning companies it would decide who's +going to win designating specific + + align:start position:0% +going to win designating specific + + + align:start position:0% +going to win designating specific +companies for funding and it would you + + align:start position:0% +companies for funding and it would you + + + align:start position:0% +companies for funding and it would you +know attempt to influence corporate + + align:start position:0% +know attempt to influence corporate + + + align:start position:0% +know attempt to influence corporate +mergers and consolidations to develop + + align:start position:0% +mergers and consolidations to develop + + + align:start position:0% +mergers and consolidations to develop +strong companies so it's intervening at + + align:start position:0% +strong companies so it's intervening at + + + align:start position:0% +strong companies so it's intervening at +the company stage pretty systematically + + align:start position:0% +the company stage pretty systematically + + + align:start position:0% +the company stage pretty systematically +at critical areas and in newer period + + align:start position:0% +at critical areas and in newer period + + + align:start position:0% +at critical areas and in newer period +media became much more collaborative and + + align:start position:0% +media became much more collaborative and + + + align:start position:0% +media became much more collaborative and +its funding a range of companies at a + + align:start position:0% +its funding a range of companies at a + + + align:start position:0% +its funding a range of companies at a +range of collaboration models not + + align:start position:0% +range of collaboration models not + + + align:start position:0% +range of collaboration models not +attempting to target particular + + align:start position:0% +attempting to target particular + + + align:start position:0% +attempting to target particular +surviving firms and winners so you know + + align:start position:0% +surviving firms and winners so you know + + + align:start position:0% +surviving firms and winners so you know +in the in the computing area for example + + align:start position:0% +in the in the computing area for example + + + align:start position:0% +in the in the computing area for example +meeting goes from funding three firms + + align:start position:0% +meeting goes from funding three firms + + + align:start position:0% +meeting goes from funding three firms +over a 30-year period to 25 firms + + align:start position:0% +over a 30-year period to 25 firms + + + align:start position:0% +over a 30-year period to 25 firms +you know at the end of that period so + + align:start position:0% +you know at the end of that period so + + + align:start position:0% +you know at the end of that period so +it's moving towards a system that is + + align:start position:0% +it's moving towards a system that is + + + align:start position:0% +it's moving towards a system that is +less centralized and more reflective of + + align:start position:0% +less centralized and more reflective of + + + align:start position:0% +less centralized and more reflective of +industry leadership and away from an + + align:start position:0% +industry leadership and away from an + + + align:start position:0% +industry leadership and away from an +integral from an interventionist + + align:start position:0% +integral from an interventionist + + + align:start position:0% +integral from an interventionist +government kind of goal so that's kind + + align:start position:0% +government kind of goal so that's kind + + + align:start position:0% +government kind of goal so that's kind +of interesting Japan gets to the to the + + align:start position:0% +of interesting Japan gets to the to the + + + align:start position:0% +of interesting Japan gets to the to the +innovation frontier to its significant + + align:start position:0% +innovation frontier to its significant + + + align:start position:0% +innovation frontier to its significant +governmental role though when it's at + + align:start position:0% +governmental role though when it's at + + + align:start position:0% +governmental role though when it's at +the frontier and it's truly a world + + align:start position:0% +the frontier and it's truly a world + + + align:start position:0% +the frontier and it's truly a world +hence competitor it's got a development + + align:start position:0% +hence competitor it's got a development + + + align:start position:0% +hence competitor it's got a development +much more decentralized approach that + + align:start position:0% +much more decentralized approach that + + + align:start position:0% +much more decentralized approach that +allows ideas to rise up from that system + + align:start position:0% +allows ideas to rise up from that system + + + align:start position:0% +allows ideas to rise up from that system +so that may be an important + + align:start position:0% +so that may be an important + + + align:start position:0% +so that may be an important +organizational model for us to consider + + align:start position:0% +organizational model for us to consider + + + align:start position:0% +organizational model for us to consider +that organizational model course is more + + align:start position:0% +that organizational model course is more + + + align:start position:0% +that organizational model course is more +like like us had a whole one now let me + + align:start position:0% +like like us had a whole one now let me + + + align:start position:0% +like like us had a whole one now let me +put Lin sue Kim into this mix too and + + align:start position:0% +put Lin sue Kim into this mix too and + + + align:start position:0% +put Lin sue Kim into this mix too and +his book human innovation is kind of a + + align:start position:0% +his book human innovation is kind of a + + + align:start position:0% +his book human innovation is kind of a +classic in looking at the amazing + + align:start position:0% +classic in looking at the amazing + + + align:start position:0% +classic in looking at the amazing +evolution of the Korean product + + align:start position:0% + + + + align:start position:0% + +the thing to understand about the Korean + + align:start position:0% +the thing to understand about the Korean + + + align:start position:0% +the thing to understand about the Korean +economy is that the country was just + + align:start position:0% +economy is that the country was just + + + align:start position:0% +economy is that the country was just +totally destroyed + + align:start position:0% +totally destroyed + + + align:start position:0% +totally destroyed +and every inch of that nation was fought + + align:start position:0% +and every inch of that nation was fought + + + align:start position:0% +and every inch of that nation was fought +over over a multi-year period and + + align:start position:0% +over over a multi-year period and + + + align:start position:0% +over over a multi-year period and +because nothing was outstanding it's a + + align:start position:0% +because nothing was outstanding it's a + + + align:start position:0% +because nothing was outstanding it's a +complete tragedy and the population is + + align:start position:0% +complete tragedy and the population is + + + align:start position:0% +complete tragedy and the population is +completely disrupted it's forced to no + + align:start position:0% +completely disrupted it's forced to no + + + align:start position:0% +completely disrupted it's forced to no +move wall about the country families are + + align:start position:0% +move wall about the country families are + + + align:start position:0% +move wall about the country families are +disrupted communities and villages and + + align:start position:0% +disrupted communities and villages and + + + align:start position:0% +disrupted communities and villages and +we disrupted it's all thrown together + + align:start position:0% +we disrupted it's all thrown together + + + align:start position:0% +we disrupted it's all thrown together +and it's it's truly tragic and yet out + + align:start position:0% +and it's it's truly tragic and yet out + + + align:start position:0% +and it's it's truly tragic and yet out +of that tragedy is one of the most + + align:start position:0% +of that tragedy is one of the most + + + align:start position:0% +of that tragedy is one of the most +remarkable stories of you know + + align:start position:0% +remarkable stories of you know + + + align:start position:0% +remarkable stories of you know +industries scale-up and growth and + + align:start position:0% +industries scale-up and growth and + + + align:start position:0% +industries scale-up and growth and +growth of the country that it's an + + align:start position:0% +growth of the country that it's an + + + align:start position:0% +growth of the country that it's an +amazing story right and essentially in a + + align:start position:0% +amazing story right and essentially in a + + + align:start position:0% +amazing story right and essentially in a +thirty year period to construct an + + align:start position:0% +thirty year period to construct an + + + align:start position:0% +thirty year period to construct an +economy literally nothing that's right + + align:start position:0% +economy literally nothing that's right + + + align:start position:0% +economy literally nothing that's right +is pretty advanced so what's behind this + + align:start position:0% +is pretty advanced so what's behind this + + + align:start position:0% +is pretty advanced so what's behind this +so in the 1960s period + + align:start position:0% +so in the 1960s period + + + align:start position:0% +so in the 1960s period +Vincent Kim argues that you know Korean + + align:start position:0% +Vincent Kim argues that you know Korean + + + align:start position:0% +Vincent Kim argues that you know Korean +firms are on eight what he calls a + + align:start position:0% +firms are on eight what he calls a + + + align:start position:0% +firms are on eight what he calls a +leadership trajectory and the government + + align:start position:0% +leadership trajectory and the government + + + align:start position:0% +leadership trajectory and the government +is on a model of what he calls forced + + align:start position:0% +is on a model of what he calls forced + + + align:start position:0% +is on a model of what he calls forced +march industrialization so the + + align:start position:0% +march industrialization so the + + + align:start position:0% +march industrialization so the +government is supplying education + + align:start position:0% +government is supplying education + + + align:start position:0% +government is supplying education +through college on the demand side it's + + align:start position:0% +through college on the demand side it's + + + align:start position:0% +through college on the demand side it's +creating shape bowls which are somewhat + + align:start position:0% +creating shape bowls which are somewhat + + + align:start position:0% +creating shape bowls which are somewhat +akin to the Koretz of model we were + + align:start position:0% +akin to the Koretz of model we were + + + align:start position:0% +akin to the Koretz of model we were +threatening that of Japan other words + + align:start position:0% +threatening that of Japan other words + + + align:start position:0% +threatening that of Japan other words +these are major industry leaders and you + + align:start position:0% +these are major industry leaders and you + + + align:start position:0% +these are major industry leaders and you +know the difficulty in this mix in the + + align:start position:0% +know the difficulty in this mix in the + + + align:start position:0% +know the difficulty in this mix in the +government of the time was its + + align:start position:0% +government of the time was its + + + align:start position:0% +government of the time was its +corruption and this is Korean Korea + + align:start position:0% +corruption and this is Korean Korea + + + align:start position:0% +corruption and this is Korean Korea +still innate in the hands of a + + align:start position:0% +still innate in the hands of a + + + align:start position:0% +still innate in the hands of a +dictatorship with corruption problems + + align:start position:0% +dictatorship with corruption problems + + + align:start position:0% +dictatorship with corruption problems +and problem with corruption is creates + + align:start position:0% +and problem with corruption is creates + + + align:start position:0% +and problem with corruption is creates +two minutes uncertainty and your + + align:start position:0% +two minutes uncertainty and your + + + align:start position:0% +two minutes uncertainty and your +business and you know that was a you + + align:start position:0% +business and you know that was a you + + + align:start position:0% +business and you know that was a you +know kind of a difficult factor but + + align:start position:0% +know kind of a difficult factor but + + + align:start position:0% +know kind of a difficult factor but +nonetheless the government is planet key + + align:start position:0% +nonetheless the government is planet key + + + align:start position:0% +nonetheless the government is planet key +role and kind of pushing these major + + align:start position:0% +role and kind of pushing these major + + + align:start position:0% +role and kind of pushing these major +companies on a march to to strong + + align:start position:0% +companies on a march to to strong + + + align:start position:0% +companies on a march to to strong +Internet + + align:start position:0% +Internet + + + align:start position:0% +Internet +could you clarify what you mean by + + align:start position:0% +could you clarify what you mean by + + + align:start position:0% +could you clarify what you mean by +corruption creates tremendous business + + align:start position:0% +corruption creates tremendous business + + + align:start position:0% +corruption creates tremendous business +uncertainty you're not competing with + + align:start position:0% +uncertainty you're not competing with + + + align:start position:0% +uncertainty you're not competing with +other firms based upon your superior + + align:start position:0% +other firms based upon your superior + + + align:start position:0% +other firms based upon your superior +products and her superior ability to + + align:start position:0% +products and her superior ability to + + + align:start position:0% +products and her superior ability to +manufacture suddenly a wild card is + + align:start position:0% +manufacture suddenly a wild card is + + + align:start position:0% +manufacture suddenly a wild card is +thrown into the mix and you've got to + + align:start position:0% +thrown into the mix and you've got to + + + align:start position:0% +thrown into the mix and you've got to +you know cope with the government and + + align:start position:0% +you know cope with the government and + + + align:start position:0% +you know cope with the government and +buying off the government and buying + + align:start position:0% +buying off the government and buying + + + align:start position:0% +buying off the government and buying +government support if you want to stay + + align:start position:0% +government support if you want to stay + + + align:start position:0% +government support if you want to stay +ahead so it creates a whole new variable + + align:start position:0% +ahead so it creates a whole new variable + + + align:start position:0% +ahead so it creates a whole new variable +it's much less they can't be managed by + + align:start position:0% +it's much less they can't be managed by + + + align:start position:0% +it's much less they can't be managed by +your business processes and systems so + + align:start position:0% +your business processes and systems so + + + align:start position:0% +your business processes and systems so +that's why when we read the that world + + align:start position:0% +that's why when we read the that world + + + align:start position:0% +that's why when we read the that world +economic report that's why corruption + + align:start position:0% +economic report that's why corruption + + + align:start position:0% +economic report that's why corruption +was actually one of the factors that was + + align:start position:0% +was actually one of the factors that was + + + align:start position:0% +was actually one of the factors that was +considered in the strength of your + + align:start position:0% +considered in the strength of your + + + align:start position:0% +considered in the strength of your +economic is because it can be so + + align:start position:0% +economic is because it can be so + + + align:start position:0% +economic is because it can be so +disruptive but the ability to have a + + align:start position:0% +disruptive but the ability to have a + + + align:start position:0% +disruptive but the ability to have a +reasonable unfair competition system so + + align:start position:0% +reasonable unfair competition system so + + + align:start position:0% +reasonable unfair competition system so +the table's to go back to our discussion + + align:start position:0% +the table's to go back to our discussion + + + align:start position:0% +the table's to go back to our discussion +that J polls were key to building and + + align:start position:0% +that J polls were key to building and + + + align:start position:0% +that J polls were key to building and +capturing these large scale industries + + align:start position:0% +capturing these large scale industries + + + align:start position:0% +capturing these large scale industries +now Korea will increase these major + + align:start position:0% +now Korea will increase these major + + + align:start position:0% +now Korea will increase these major +companies that dominate industrial + + align:start position:0% +companies that dominate industrial + + + align:start position:0% +companies that dominate industrial +sectors they tend to flock entry by + + align:start position:0% +sectors they tend to flock entry by + + + align:start position:0% +sectors they tend to flock entry by +small and medium sized enterprises so + + align:start position:0% +small and medium sized enterprises so + + + align:start position:0% +small and medium sized enterprises so +Korea at the same time is not creating a + + align:start position:0% +Korea at the same time is not creating a + + + align:start position:0% +Korea at the same time is not creating a +system of strong small and mid-sized + + align:start position:0% +system of strong small and mid-sized + + + align:start position:0% +system of strong small and mid-sized +firms right it's really focused on + + align:start position:0% +firms right it's really focused on + + + align:start position:0% +firms right it's really focused on +creating these big tables that can + + align:start position:0% +creating these big tables that can + + + align:start position:0% +creating these big tables that can +really function in the international + + align:start position:0% +really function in the international + + + align:start position:0% +really function in the international +market places but that in turn can + + align:start position:0% +market places but that in turn can + + + align:start position:0% +market places but that in turn can +create inefficiencies as well their + + align:start position:0% +create inefficiencies as well their + + + align:start position:0% +create inefficiencies as well their +markets in education Korea hit on a + + align:start position:0% +markets in education Korea hit on a + + + align:start position:0% +markets in education Korea hit on a +model of widespread education and that + + align:start position:0% +model of widespread education and that + + + align:start position:0% +model of widespread education and that +is it's a dramatic story I mean the + + align:start position:0% +is it's a dramatic story I mean the + + + align:start position:0% +is it's a dramatic story I mean the +college completion right there is + + align:start position:0% +college completion right there is + + + align:start position:0% +college completion right there is +breathtaking and you know the focus is + + align:start position:0% +breathtaking and you know the focus is + + + align:start position:0% +breathtaking and you know the focus is +to get a very highly educated population + + align:start position:0% +to get a very highly educated population + + + align:start position:0% +to get a very highly educated population +which they have achieved right and then + + align:start position:0% +which they have achieved right and then + + + align:start position:0% +which they have achieved right and then +that highly educated population is able + + align:start position:0% +that highly educated population is able + + + align:start position:0% +that highly educated population is able +to staff ever more sophisticated + + align:start position:0% +to staff ever more sophisticated + + + align:start position:0% +to staff ever more sophisticated +industries right that's that's the model + + align:start position:0% +industries right that's that's the model + + + align:start position:0% +industries right that's that's the model +and it works the one thing they don't do + + align:start position:0% +and it works the one thing they don't do + + + align:start position:0% +and it works the one thing they don't do +is move their colleges into research + + align:start position:0% +is move their colleges into research + + + align:start position:0% +is move their colleges into research +universities + + align:start position:0% +universities + + + align:start position:0% +universities +which Kim argues is still a part of the + + align:start position:0% +which Kim argues is still a part of the + + + align:start position:0% +which Kim argues is still a part of the +model in Easton achieved there's a very + + align:start position:0% +model in Easton achieved there's a very + + + align:start position:0% +model in Easton achieved there's a very +strong export strategy in Korea and the + + align:start position:0% +strong export strategy in Korea and the + + + align:start position:0% +strong export strategy in Korea and the +Martino resource institutions do they + + align:start position:0% +Martino resource institutions do they + + + align:start position:0% +Martino resource institutions do they +just like to send their people to study + + align:start position:0% +just like to send their people to study + + + align:start position:0% +just like to send their people to study +at those institutions in yeah they have + + align:start position:0% +at those institutions in yeah they have + + + align:start position:0% +at those institutions in yeah they have +government only supported research + + align:start position:0% +government only supported research + + + align:start position:0% +government only supported research +institutions a little more on that in a + + align:start position:0% +institutions a little more on that in a + + + align:start position:0% +institutions a little more on that in a +second wisdom of the u.s. model is that + + align:start position:0% +second wisdom of the u.s. model is that + + + align:start position:0% +second wisdom of the u.s. model is that +you combine the education system with + + align:start position:0% +you combine the education system with + + + align:start position:0% +you combine the education system with +the resources and therefore you create a + + align:start position:0% +the resources and therefore you create a + + + align:start position:0% +the resources and therefore you create a +tremendous amount of learning by doing + + align:start position:0% +tremendous amount of learning by doing + + + align:start position:0% +tremendous amount of learning by doing +right seems to work pretty well if + + align:start position:0% +right seems to work pretty well if + + + align:start position:0% +right seems to work pretty well if +you're just supporting research in + + align:start position:0% +you're just supporting research in + + + align:start position:0% +you're just supporting research in +separate research entities you miss that + + align:start position:0% +separate research entities you miss that + + + align:start position:0% +separate research entities you miss that +the dynamics of that education + + align:start position:0% +the dynamics of that education + + + align:start position:0% +the dynamics of that education +connection time right doesn't work as + + align:start position:0% +connection time right doesn't work as + + + align:start position:0% +connection time right doesn't work as +smooth as I think it must be with + + align:start position:0% +smooth as I think it must be with + + + align:start position:0% +smooth as I think it must be with +resources might be more complex so they + + align:start position:0% +resources might be more complex so they + + + align:start position:0% +resources might be more complex so they +focus on making a really good college + + align:start position:0% +focus on making a really good college + + + align:start position:0% +focus on making a really good college +education that exporting their people to + + align:start position:0% +education that exporting their people to + + + align:start position:0% +education that exporting their people to +do research with in other countries they + + align:start position:0% +do research with in other countries they + + + align:start position:0% +do research with in other countries they +might just it just might be something to + + align:start position:0% +might just it just might be something to + + + align:start position:0% +might just it just might be something to +make it more efficient I think there's + + align:start position:0% + + + + align:start position:0% + +one thing that the Korean government did + + align:start position:0% +one thing that the Korean government did + + + align:start position:0% +one thing that the Korean government did +do was enforced its big companies in the + + align:start position:0% +do was enforced its big companies in the + + + align:start position:0% +do was enforced its big companies in the +international competition so they've got + + align:start position:0% +international competition so they've got + + + align:start position:0% +international competition so they've got +a you know freely mercantilist model of + + align:start position:0% +a you know freely mercantilist model of + + + align:start position:0% +a you know freely mercantilist model of +not allowing of protecting a domestic + + align:start position:0% +not allowing of protecting a domestic + + + align:start position:0% +not allowing of protecting a domestic +market for their companies but it's not + + align:start position:0% +market for their companies but it's not + + + align:start position:0% +market for their companies but it's not +that big a domestic market they've gotta + + align:start position:0% +that big a domestic market they've gotta + + + align:start position:0% +that big a domestic market they've gotta +force their companies out at the + + align:start position:0% +force their companies out at the + + + align:start position:0% +force their companies out at the +international competition and they do it + + align:start position:0% +international competition and they do it + + + align:start position:0% +international competition and they do it +right and that builds to mendes + + align:start position:0% +right and that builds to mendes + + + align:start position:0% +right and that builds to mendes +competitive strength in these firms and + + align:start position:0% +competitive strength in these firms and + + + align:start position:0% +competitive strength in these firms and +you know we look around and see the + + align:start position:0% +you know we look around and see the + + + align:start position:0% +you know we look around and see the +strong Korean firms it's pretty + + align:start position:0% +strong Korean firms it's pretty + + + align:start position:0% +strong Korean firms it's pretty +inaudible story in terms of tech trend + + align:start position:0% +inaudible story in terms of tech trend + + + align:start position:0% +inaudible story in terms of tech trend +transfer policy that policy was + + align:start position:0% +transfer policy that policy was + + + align:start position:0% +transfer policy that policy was +initially largely reverse engineering of + + align:start position:0% +initially largely reverse engineering of + + + align:start position:0% +initially largely reverse engineering of +technologies brought a broad but + + align:start position:0% +technologies brought a broad but + + + align:start position:0% +technologies brought a broad but +critical capabilities are being + + align:start position:0% +critical capabilities are being + + + align:start position:0% +critical capabilities are being +developed as part of this reverse + + align:start position:0% +developed as part of this reverse + + + align:start position:0% +developed as part of this reverse +engineering effort R&D policy it's + + align:start position:0% +engineering effort R&D policy it's + + + align:start position:0% +engineering effort R&D policy it's +focused as I mentioned before on these + + align:start position:0% +focused as I mentioned before on these + + + align:start position:0% +focused as I mentioned before on these +government research institutions the GRI + + align:start position:0% +government research institutions the GRI + + + align:start position:0% +government research institutions the GRI +is provide more of a rather than + + align:start position:0% +is provide more of a rather than + + + align:start position:0% +is provide more of a rather than +influencing industry R&D as much it's + + align:start position:0% +influencing industry R&D as much it's + + + align:start position:0% +influencing industry R&D as much it's +more of a + + align:start position:0% +more of a + + + align:start position:0% +more of a +talent base and support base as you were + + align:start position:0% +talent base and support base as you were + + + align:start position:0% +talent base and support base as you were +indeed suggesting martini for companies + + align:start position:0% +indeed suggesting martini for companies + + + align:start position:0% +indeed suggesting martini for companies +that Kim also has this very interesting + + align:start position:0% +that Kim also has this very interesting + + + align:start position:0% +that Kim also has this very interesting +discussion of Korean culture here and + + align:start position:0% +discussion of Korean culture here and + + + align:start position:0% +discussion of Korean culture here and +what's going woman that matches the + + align:start position:0% +what's going woman that matches the + + + align:start position:0% +what's going woman that matches the +evolution of this so he argues that in + + align:start position:0% +evolution of this so he argues that in + + + align:start position:0% +evolution of this so he argues that in +Korea this interesting blend of of an + + align:start position:0% +Korea this interesting blend of of an + + + align:start position:0% +Korea this interesting blend of of an +Asian Confucian culture of family and + + align:start position:0% +Asian Confucian culture of family and + + + align:start position:0% +Asian Confucian culture of family and +collective support and a collective + + align:start position:0% +collective support and a collective + + + align:start position:0% +collective support and a collective +orientation gets merged with a pretty + + align:start position:0% +orientation gets merged with a pretty + + + align:start position:0% +orientation gets merged with a pretty +high level of quite high level of + + align:start position:0% +high level of quite high level of + + + align:start position:0% +high level of quite high level of +Christianity and it's individualism for + + align:start position:0% +Christianity and it's individualism for + + + align:start position:0% +Christianity and it's individualism for +a very interesting combination effects + + align:start position:0% +a very interesting combination effects + + + align:start position:0% +a very interesting combination effects +strengths on both ends strengths them to + + align:start position:0% +strengths on both ends strengths them to + + + align:start position:0% +strengths on both ends strengths them to +call it pivot II side but also strengths + + align:start position:0% +call it pivot II side but also strengths + + + align:start position:0% +call it pivot II side but also strengths +on the individual inside some of you may + + align:start position:0% +on the individual inside some of you may + + + align:start position:0% +on the individual inside some of you may +have floods about that also the Korean + + align:start position:0% +have floods about that also the Korean + + + align:start position:0% +have floods about that also the Korean +War itself as we discussed love the + + align:start position:0% +War itself as we discussed love the + + + align:start position:0% +War itself as we discussed love the +country destroyed and you know ended + + align:start position:0% +country destroyed and you know ended + + + align:start position:0% +country destroyed and you know ended +village culture but amalgamated the + + align:start position:0% +village culture but amalgamated the + + + align:start position:0% +village culture but amalgamated the +population in a way that created a + + align:start position:0% +population in a way that created a + + + align:start position:0% +population in a way that created a +certain kind of flexibility as the old + + align:start position:0% +certain kind of flexibility as the old + + + align:start position:0% +certain kind of flexibility as the old +social and cultural barriers were swept + + align:start position:0% +social and cultural barriers were swept + + + align:start position:0% +social and cultural barriers were swept +away so that it wasn't all bad I guess + + align:start position:0% +away so that it wasn't all bad I guess + + + align:start position:0% +away so that it wasn't all bad I guess +what would be kim's conclusion and then + + align:start position:0% +what would be kim's conclusion and then + + + align:start position:0% +what would be kim's conclusion and then +because it's a country that has constant + + align:start position:0% +because it's a country that has constant + + + align:start position:0% +because it's a country that has constant +threat of war with North Korea the + + align:start position:0% +threat of war with North Korea the + + + align:start position:0% +threat of war with North Korea the +University Universal military service + + align:start position:0% +University Universal military service + + + align:start position:0% +University Universal military service +provides a huge training opportunity for + + align:start position:0% +provides a huge training opportunity for + + + align:start position:0% +provides a huge training opportunity for +a management class in effect and you + + align:start position:0% +a management class in effect and you + + + align:start position:0% +a management class in effect and you +know since military's to be affect it + + align:start position:0% +know since military's to be affect it + + + align:start position:0% +know since military's to be affect it +has to be pretty meritocratic right it + + align:start position:0% +has to be pretty meritocratic right it + + + align:start position:0% +has to be pretty meritocratic right it +introduces a whole meritocracy system + + align:start position:0% +introduces a whole meritocracy system + + + align:start position:0% +introduces a whole meritocracy system +into Korean society and culture you know + + align:start position:0% +into Korean society and culture you know + + + align:start position:0% +into Korean society and culture you know +replacing an older village more + + align:start position:0% +replacing an older village more + + + align:start position:0% +replacing an older village more +classroom culture so it tends to create + + align:start position:0% +classroom culture so it tends to create + + + align:start position:0% +classroom culture so it tends to create +a significant there's a series of forces + + align:start position:0% +a significant there's a series of forces + + + align:start position:0% +a significant there's a series of forces +here that tend to create a certain + + align:start position:0% +here that tend to create a certain + + + align:start position:0% +here that tend to create a certain +amount of social mobility and + + align:start position:0% +amount of social mobility and + + + align:start position:0% +amount of social mobility and +elimination of historic social classes + + align:start position:0% +elimination of historic social classes + + + align:start position:0% +elimination of historic social classes +which is part of the story that enables + + align:start position:0% + + + + align:start position:0% + +Kent Margot is Korea to to thrive you + + align:start position:0% +Kent Margot is Korea to to thrive you + + + align:start position:0% +Kent Margot is Korea to to thrive you +know that military services in an artist + + align:start position:0% +know that military services in an artist + + + align:start position:0% +know that military services in an artist +feature right I mean our military back + + align:start position:0% +feature right I mean our military back + + + align:start position:0% +feature right I mean our military back +in the days which I can remember you + + align:start position:0% +in the days which I can remember you + + + align:start position:0% +in the days which I can remember you +can't when they draft the US military + + align:start position:0% +can't when they draft the US military + + + align:start position:0% +can't when they draft the US military +was actually a very important integrated + + align:start position:0% +was actually a very important integrated + + + align:start position:0% +was actually a very important integrated +force in the society right that was a + + align:start position:0% +force in the society right that was a + + + align:start position:0% +force in the society right that was a +very critical step in the u.s. to + + align:start position:0% +very critical step in the u.s. to + + + align:start position:0% +very critical step in the u.s. to +promote racial integration when you add + + align:start position:0% +promote racial integration when you add + + + align:start position:0% +promote racial integration when you add +integrated military units the height of + + align:start position:0% +integrated military units the height of + + + align:start position:0% +integrated military units the height of +threats of warfare in combat it really + + align:start position:0% +threats of warfare in combat it really + + + align:start position:0% +threats of warfare in combat it really +changed a lot of things in the society + + align:start position:0% +changed a lot of things in the society + + + align:start position:0% +changed a lot of things in the society +so it's there's just an interesting side + + align:start position:0% +so it's there's just an interesting side + + + align:start position:0% +so it's there's just an interesting side +note there about what that kind of + + align:start position:0% +note there about what that kind of + + + align:start position:0% +note there about what that kind of +social organization can mean in a social + + align:start position:0% +social organization can mean in a social + + + align:start position:0% +social organization can mean in a social +context but if Kim argues that it's + + align:start position:0% +context but if Kim argues that it's + + + align:start position:0% +context but if Kim argues that it's +important in Korea so Korea develops he + + align:start position:0% +important in Korea so Korea develops he + + + align:start position:0% +important in Korea so Korea develops he +argues a learning technology culture so + + align:start position:0% +argues a learning technology culture so + + + align:start position:0% +argues a learning technology culture so +that firms go from what he calls + + align:start position:0% +that firms go from what he calls + + + align:start position:0% +that firms go from what he calls +poaching and kind of reverse engineering + + align:start position:0% +poaching and kind of reverse engineering + + + align:start position:0% +poaching and kind of reverse engineering +and then to reverse engineering then to + + align:start position:0% +and then to reverse engineering then to + + + align:start position:0% +and then to reverse engineering then to +R&D and then to true innovation right so + + align:start position:0% +R&D and then to true innovation right so + + + align:start position:0% +R&D and then to true innovation right so +Chris let me right at the technology + + align:start position:0% +Chris let me right at the technology + + + align:start position:0% +Chris let me right at the technology +front in our whole series of areas and + + align:start position:0% +front in our whole series of areas and + + + align:start position:0% +front in our whole series of areas and +they moved through a series of steps to + + align:start position:0% +they moved through a series of steps to + + + align:start position:0% +they moved through a series of steps to +get there and Kim artists that these are + + align:start position:0% +get there and Kim artists that these are + + + align:start position:0% +get there and Kim artists that these are +these are steps and you know we tend to + + align:start position:0% +these are steps and you know we tend to + + + align:start position:0% +these are steps and you know we tend to +frown on poaching reverse engineering + + align:start position:0% +frown on poaching reverse engineering + + + align:start position:0% +frown on poaching reverse engineering +but let me remind remind us that you + + align:start position:0% +but let me remind remind us that you + + + align:start position:0% +but let me remind remind us that you +know the first textile industry in the + + align:start position:0% +know the first textile industry in the + + + align:start position:0% +know the first textile industry in the +US was set up and popped up in Rhode + + align:start position:0% +US was set up and popped up in Rhode + + + align:start position:0% +US was set up and popped up in Rhode +Island by an English immigrant named + + align:start position:0% +Island by an English immigrant named + + + align:start position:0% +Island by an English immigrant named +Samuel Slater and Samuel Slater is + + align:start position:0% +Samuel Slater and Samuel Slater is + + + align:start position:0% +Samuel Slater and Samuel Slater is +working in the British textile factories + + align:start position:0% +working in the British textile factories + + + align:start position:0% +working in the British textile factories +and the British textile factories + + align:start position:0% +and the British textile factories + + + align:start position:0% +and the British textile factories +realize they've got a monopoly on + + align:start position:0% +realize they've got a monopoly on + + + align:start position:0% +realize they've got a monopoly on +textile production efficiency worldwide + + align:start position:0% +textile production efficiency worldwide + + + align:start position:0% +textile production efficiency worldwide +and they don't want anybody else to have + + align:start position:0% +and they don't want anybody else to have + + + align:start position:0% +and they don't want anybody else to have +it so you're subjected to a body search + + align:start position:0% +it so you're subjected to a body search + + + align:start position:0% +it so you're subjected to a body search +to make sure you're not walking out with + + align:start position:0% +to make sure you're not walking out with + + + align:start position:0% +to make sure you're not walking out with +plans if you're an employee in these + + align:start position:0% +plans if you're an employee in these + + + align:start position:0% +plans if you're an employee in these +factories + + align:start position:0% +factories + + + align:start position:0% +factories +and Slater is you know served every kind + + align:start position:0% +and Slater is you know served every kind + + + align:start position:0% +and Slater is you know served every kind +of Lisa Finn agree what his British + + align:start position:0% +of Lisa Finn agree what his British + + + align:start position:0% +of Lisa Finn agree what his British +employers didn't realize is that he had + + align:start position:0% +employers didn't realize is that he had + + + align:start position:0% +employers didn't realize is that he had +a photographic memory right so he worked + + align:start position:0% +a photographic memory right so he worked + + + align:start position:0% +a photographic memory right so he worked +for this textile equipment because the + + align:start position:0% +for this textile equipment because the + + + align:start position:0% +for this textile equipment because the +United States since up the seams and + + align:start position:0% +United States since up the seams and + + + align:start position:0% +United States since up the seams and +brings you know textile industry so talk + + align:start position:0% +brings you know textile industry so talk + + + align:start position:0% +brings you know textile industry so talk +about poaching that straight poaching so + + align:start position:0% +about poaching that straight poaching so + + + align:start position:0% +about poaching that straight poaching so +the textile industry the United States + + align:start position:0% +the textile industry the United States + + + align:start position:0% +the textile industry the United States +is organized essentially do the same + + align:start position:0% +is organized essentially do the same + + + align:start position:0% +is organized essentially do the same +model and that arguably the same stage + + align:start position:0% +model and that arguably the same stage + + + align:start position:0% +model and that arguably the same stage +we went through when Lawrence and Lowell + + align:start position:0% +we went through when Lawrence and Lowell + + + align:start position:0% +we went through when Lawrence and Lowell +are established here in Massachusetts + + align:start position:0% +are established here in Massachusetts + + + align:start position:0% +are established here in Massachusetts +we're definitely into technological + + align:start position:0% +we're definitely into technological + + + align:start position:0% +we're definitely into technological +advances at the frontier of textile + + align:start position:0% +advances at the frontier of textile + + + align:start position:0% +advances at the frontier of textile +commercial so in a way we went to + + align:start position:0% +commercial so in a way we went to + + + align:start position:0% +commercial so in a way we went to +similar stages are in the investment so + + align:start position:0% +similar stages are in the investment so + + + align:start position:0% +similar stages are in the investment so +that is very heavy aren't the + + align:start position:0% +that is very heavy aren't the + + + align:start position:0% +that is very heavy aren't the +investments by the trick in the industry + + align:start position:0% +investments by the trick in the industry + + + align:start position:0% +investments by the trick in the industry +che polls but the issue Kim raises is + + align:start position:0% +che polls but the issue Kim raises is + + + align:start position:0% +che polls but the issue Kim raises is +that there's not enough SME small and + + align:start position:0% +that there's not enough SME small and + + + align:start position:0% +that there's not enough SME small and +mid-sized enterprises to provide + + align:start position:0% +mid-sized enterprises to provide + + + align:start position:0% +mid-sized enterprises to provide +out-of-the-box kind of ideas of thinking + + align:start position:0% +out-of-the-box kind of ideas of thinking + + + align:start position:0% +out-of-the-box kind of ideas of thinking +in the next and that that's a problem in + + align:start position:0% +in the next and that that's a problem in + + + align:start position:0% +in the next and that that's a problem in +the system the argues things needs to be + + align:start position:0% +the system the argues things needs to be + + + align:start position:0% +the system the argues things needs to be +changed + + align:start position:0% +changed + + + align:start position:0% +changed +the creole overall it's got a very high + + align:start position:0% +the creole overall it's got a very high + + + align:start position:0% +the creole overall it's got a very high +R&D to gene information higher than us + + align:start position:0% +R&D to gene information higher than us + + + align:start position:0% +R&D to gene information higher than us +so the problems are limited university + + align:start position:0% +so the problems are limited university + + + align:start position:0% +so the problems are limited university +are in need of the need for a larger SME + + align:start position:0% +are in need of the need for a larger SME + + + align:start position:0% +are in need of the need for a larger SME +entrepreneurial base he argues that a + + align:start position:0% +entrepreneurial base he argues that a + + + align:start position:0% +entrepreneurial base he argues that a +more liberalized economy away from the + + align:start position:0% +more liberalized economy away from the + + + align:start position:0% +more liberalized economy away from the +kind of elite tribal control is an + + align:start position:0% +kind of elite tribal control is an + + + align:start position:0% +kind of elite tribal control is an +important step but there's a lot of + + align:start position:0% +important step but there's a lot of + + + align:start position:0% +important step but there's a lot of +lessons from korea the role of a strong + + align:start position:0% +lessons from korea the role of a strong + + + align:start position:0% +lessons from korea the role of a strong +governmental the leadership in creating + + align:start position:0% +governmental the leadership in creating + + + align:start position:0% +governmental the leadership in creating +strong firms but in effect of forcing + + align:start position:0% +strong firms but in effect of forcing + + + align:start position:0% +strong firms but in effect of forcing +them into international competition it's + + align:start position:0% +them into international competition it's + + + align:start position:0% +them into international competition it's +darling and the government education + + align:start position:0% +darling and the government education + + + align:start position:0% +darling and the government education +programs that facilitate + + align:start position:0% +programs that facilitate + + + align:start position:0% +programs that facilitate +very very strong talent base country + + align:start position:0% +very very strong talent base country + + + align:start position:0% +very very strong talent base country +were clearly key and the university of + + align:start position:0% +were clearly key and the university of + + + align:start position:0% +were clearly key and the university of +euclid a government used crisis to kind + + align:start position:0% +euclid a government used crisis to kind + + + align:start position:0% +euclid a government used crisis to kind +of force its firms would in effect force + + align:start position:0% +of force its firms would in effect force + + + align:start position:0% +of force its firms would in effect force +its firms into a crisis kind of + + align:start position:0% +its firms into a crisis kind of + + + align:start position:0% +its firms into a crisis kind of +circumstance + + align:start position:0% +circumstance + + + align:start position:0% +circumstance +so they really learn how to compete and + + align:start position:0% +so they really learn how to compete and + + + align:start position:0% +so they really learn how to compete and +survive so those are all kind of + + align:start position:0% +survive so those are all kind of + + + align:start position:0% +survive so those are all kind of +interesting lessons from Korea so who + + align:start position:0% +interesting lessons from Korea so who + + + align:start position:0% +interesting lessons from Korea so who +has got Lin sue Kim and who's got + + align:start position:0% +has got Lin sue Kim and who's got + + + align:start position:0% +has got Lin sue Kim and who's got +platforms I have okay and you've got + + align:start position:0% +platforms I have okay and you've got + + + align:start position:0% +platforms I have okay and you've got +plentiful so why don't we start with you + + align:start position:0% +plentiful so why don't we start with you + + + align:start position:0% +plentiful so why don't we start with you +Matt so I think this job covering a lot + + align:start position:0% +Matt so I think this job covering a lot + + + align:start position:0% +Matt so I think this job covering a lot +of his main points I think you know + + align:start position:0% +of his main points I think you know + + + align:start position:0% +of his main points I think you know +really interesting is when Fogg he kind + + align:start position:0% +really interesting is when Fogg he kind + + + align:start position:0% +really interesting is when Fogg he kind +of turns this argument instead where + + align:start position:0% +of turns this argument instead where + + + align:start position:0% +of turns this argument instead where +most people would think about your + + align:start position:0% +most people would think about your + + + align:start position:0% +most people would think about your +political structures kind of determining + + align:start position:0% +political structures kind of determining + + + align:start position:0% +political structures kind of determining +how competitive in economy is letting go + + align:start position:0% +how competitive in economy is letting go + + + align:start position:0% +how competitive in economy is letting go +Ted the competitiveness of the economy + + align:start position:0% +Ted the competitiveness of the economy + + + align:start position:0% +Ted the competitiveness of the economy +international competitive + + align:start position:0% +international competitive + + + align:start position:0% +international competitive +competitiveness driving the imperative + + align:start position:0% +competitiveness driving the imperative + + + align:start position:0% +competitiveness driving the imperative +of the political structure and how + + align:start position:0% +of the political structure and how + + + align:start position:0% +of the political structure and how +involved is he comes as the country + + align:start position:0% +involved is he comes as the country + + + align:start position:0% +involved is he comes as the country +moves from pursuer after the pioneer to + + align:start position:0% +moves from pursuer after the pioneer to + + + align:start position:0% +moves from pursuer after the pioneer to +follower at the frontier and he gives + + align:start position:0% +follower at the frontier and he gives + + + align:start position:0% +follower at the frontier and he gives +the example of Japan one one theme that + + align:start position:0% +the example of Japan one one theme that + + + align:start position:0% +the example of Japan one one theme that +I saw throughout the question is how + + align:start position:0% +I saw throughout the question is how + + + align:start position:0% +I saw throughout the question is how +much of that process is a conscious + + align:start position:0% +much of that process is a conscious + + + align:start position:0% +much of that process is a conscious +decision or how much of it just kind of + + align:start position:0% +decision or how much of it just kind of + + + align:start position:0% +decision or how much of it just kind of +happens naturally is there a certain + + align:start position:0% +happens naturally is there a certain + + + align:start position:0% +happens naturally is there a certain +point when they win the government says + + align:start position:0% +point when they win the government says + + + align:start position:0% +point when they win the government says +hey we are you know approaching your + + align:start position:0% +hey we are you know approaching your + + + align:start position:0% +hey we are you know approaching your +frontier now we should be hands-off or + + align:start position:0% +frontier now we should be hands-off or + + + align:start position:0% +frontier now we should be hands-off or +how does that end up happening in + + align:start position:0% +how does that end up happening in + + + align:start position:0% +how does that end up happening in +practice + + align:start position:0% + + + + align:start position:0% + +I think the approach is probably the + + align:start position:0% +I think the approach is probably the + + + align:start position:0% +I think the approach is probably the +most difficult part of the process just + + align:start position:0% +most difficult part of the process just + + + align:start position:0% +most difficult part of the process just +as you have to sort of set up and + + align:start position:0% +as you have to sort of set up and + + + align:start position:0% +as you have to sort of set up and +protect sort of the tables and systems + + align:start position:0% +protect sort of the tables and systems + + + align:start position:0% +protect sort of the tables and systems +have to be put in place that kind of + + align:start position:0% +have to be put in place that kind of + + + align:start position:0% +have to be put in place that kind of +borrow on eserve cultural values you + + align:start position:0% +borrow on eserve cultural values you + + + align:start position:0% +borrow on eserve cultural values you +mentioned the strong military service at + + align:start position:0% +mentioned the strong military service at + + + align:start position:0% +mentioned the strong military service at +this point and a lot of other things + + align:start position:0% +this point and a lot of other things + + + align:start position:0% +this point and a lot of other things +sort of have to come together and so I + + align:start position:0% +sort of have to come together and so I + + + align:start position:0% +sort of have to come together and so I +would peg the approaches or the hardest + + align:start position:0% +would peg the approaches or the hardest + + + align:start position:0% +would peg the approaches or the hardest +part but I think once you have your + + align:start position:0% +part but I think once you have your + + + align:start position:0% +part but I think once you have your +system set up and you're looking to sort + + align:start position:0% +system set up and you're looking to sort + + + align:start position:0% +system set up and you're looking to sort +of compete like internationally I think + + align:start position:0% +of compete like internationally I think + + + align:start position:0% +of compete like internationally I think +that's the point where you have to sort + + align:start position:0% +that's the point where you have to sort + + + align:start position:0% +that's the point where you have to sort +of kind of let go but I think you need + + align:start position:0% +of kind of let go but I think you need + + + align:start position:0% +of kind of let go but I think you need +to reach some sort of maturity and I + + align:start position:0% +to reach some sort of maturity and I + + + align:start position:0% +to reach some sort of maturity and I +think it's pretty easy to say like okay + + align:start position:0% +think it's pretty easy to say like okay + + + align:start position:0% +think it's pretty easy to say like okay +look we've copied everything we've you + + align:start position:0% +look we've copied everything we've you + + + align:start position:0% +look we've copied everything we've you +know been able to copy like what's next + + align:start position:0% +know been able to copy like what's next + + + align:start position:0% +know been able to copy like what's next +I would if you don't have anything + + align:start position:0% +I would if you don't have anything + + + align:start position:0% +I would if you don't have anything +that's like it might be tough to sort of + + align:start position:0% +that's like it might be tough to sort of + + + align:start position:0% +that's like it might be tough to sort of +kind of diversify and kind of like + + align:start position:0% +kind of diversify and kind of like + + + align:start position:0% +kind of diversify and kind of like +things go so is she just use conforms to + + align:start position:0% +things go so is she just use conforms to + + + align:start position:0% +things go so is she just use conforms to +terms and correct me if I've got this + + align:start position:0% +terms and correct me if I've got this + + + align:start position:0% +terms and correct me if I've got this +but when you move from pursuer of a + + align:start position:0% +but when you move from pursuer of a + + + align:start position:0% +but when you move from pursuer of a +pioneer to right at the technological + + align:start position:0% +pioneer to right at the technological + + + align:start position:0% +pioneer to right at the technological +frontier that's the moment where you + + align:start position:0% +frontier that's the moment where you + + + align:start position:0% +frontier that's the moment where you +ought to think about your organization a + + align:start position:0% +ought to think about your organization a + + + align:start position:0% +ought to think about your organization a +lot because to get to that world-class + + align:start position:0% +lot because to get to that world-class + + + align:start position:0% +lot because to get to that world-class +leadership like this may require you to + + align:start position:0% +leadership like this may require you to + + + align:start position:0% +leadership like this may require you to +decentralize and change your + + align:start position:0% +decentralize and change your + + + align:start position:0% +decentralize and change your +governmental role more collaborative + + align:start position:0% +governmental role more collaborative + + + align:start position:0% +governmental role more collaborative +model rely on larger number of players + + align:start position:0% +model rely on larger number of players + + + align:start position:0% +model rely on larger number of players +that be you agree Matt with that yeah I + + align:start position:0% +that be you agree Matt with that yeah I + + + align:start position:0% +that be you agree Matt with that yeah I +think well the way that you said it + + align:start position:0% +think well the way that you said it + + + align:start position:0% +think well the way that you said it +almost no implies that there's a very + + align:start position:0% +almost no implies that there's a very + + + align:start position:0% +almost no implies that there's a very +conscious decision about how how much + + align:start position:0% +conscious decision about how how much + + + align:start position:0% +conscious decision about how how much +the only thing he bought I think for + + align:start position:0% +the only thing he bought I think for + + + align:start position:0% +the only thing he bought I think for +Japan what happened was they realized + + align:start position:0% +Japan what happened was they realized + + + align:start position:0% +Japan what happened was they realized +the misty ID bush right that was lived + + align:start position:0% +the misty ID bush right that was lived + + + align:start position:0% +the misty ID bush right that was lived +by US companies and we'll read about + + align:start position:0% +by US companies and we'll read about + + + align:start position:0% +by US companies and we'll read about +DARPA and the IT revolution in the labor + + align:start position:0% +DARPA and the IT revolution in the labor + + + align:start position:0% +DARPA and the IT revolution in the labor +class but you'll see where that comes + + align:start position:0% +class but you'll see where that comes + + + align:start position:0% +class but you'll see where that comes +from + + align:start position:0% +from + + + align:start position:0% +from +by having an R&D system those refocused + + align:start position:0% +by having an R&D system those refocused + + + align:start position:0% +by having an R&D system those refocused +on applied work with industry + + align:start position:0% +on applied work with industry + + + align:start position:0% +on applied work with industry +as opposed to university search you get + + align:start position:0% +as opposed to university search you get + + + align:start position:0% +as opposed to university search you get +very good at the incremental advances + + align:start position:0% +very good at the incremental advances + + + align:start position:0% +very good at the incremental advances +but you made this fundamental + + align:start position:0% +but you made this fundamental + + + align:start position:0% +but you made this fundamental +breakthroughs and so I think Japan is + + align:start position:0% +breakthroughs and so I think Japan is + + + align:start position:0% +breakthroughs and so I think Japan is +waking up and 1998 to these realities + + align:start position:0% +waking up and 1998 to these realities + + + align:start position:0% +waking up and 1998 to these realities +and trying to think about its innovation + + align:start position:0% +and trying to think about its innovation + + + align:start position:0% +and trying to think about its innovation +organisation larger than you of + + align:start position:0% +organisation larger than you of + + + align:start position:0% +organisation larger than you of +innovation that would be my guess the + + align:start position:0% +innovation that would be my guess the + + + align:start position:0% +innovation that would be my guess the +other thing I had was uses Japan as an + + align:start position:0% +other thing I had was uses Japan as an + + + align:start position:0% +other thing I had was uses Japan as an +example I like looking at Korea and + + align:start position:0% +example I like looking at Korea and + + + align:start position:0% +example I like looking at Korea and +those seem to fit you know the motto but + + align:start position:0% +those seem to fit you know the motto but + + + align:start position:0% +those seem to fit you know the motto but +you know to what extent does does this + + align:start position:0% +you know to what extent does does this + + + align:start position:0% +you know to what extent does does this +model actually general and so rather top + + align:start position:0% +model actually general and so rather top + + + align:start position:0% +model actually general and so rather top +of my head if you think of like you know + + align:start position:0% +of my head if you think of like you know + + + align:start position:0% +of my head if you think of like you know +the u.s. space program with like the + + align:start position:0% +the u.s. space program with like the + + + align:start position:0% +the u.s. space program with like the +Manhattan Project but it's very much at + + align:start position:0% +Manhattan Project but it's very much at + + + align:start position:0% +Manhattan Project but it's very much at +the competitive frontier but strong + + align:start position:0% +the competitive frontier but strong + + + align:start position:0% +the competitive frontier but strong +government involvement and basically + + align:start position:0% +government involvement and basically + + + align:start position:0% +government involvement and basically +targeting technologies did lead to major + + align:start position:0% +targeting technologies did lead to major + + + align:start position:0% +targeting technologies did lead to major +advances + + align:start position:0% + + + + align:start position:0% + +I do do we think that it that the model + + align:start position:0% +I do do we think that it that the model + + + align:start position:0% +I do do we think that it that the model +actually works all the time or is it + + align:start position:0% +actually works all the time or is it + + + align:start position:0% +actually works all the time or is it +necessary use the best thing to be doing + + align:start position:0% + + + + align:start position:0% + +help out Matthew Jemaine I hear it's got + + align:start position:0% +help out Matthew Jemaine I hear it's got + + + align:start position:0% +help out Matthew Jemaine I hear it's got +a lifeline out there which won't drink + + align:start position:0% +a lifeline out there which won't drink + + + align:start position:0% +a lifeline out there which won't drink +since why me in the general discourse of + + align:start position:0% +since why me in the general discourse of + + + align:start position:0% +since why me in the general discourse of +innovation only pay attention take these + + align:start position:0% +innovation only pay attention take these + + + align:start position:0% +innovation only pay attention take these +Asian countries or largely pay attention + + align:start position:0% +Asian countries or largely pay attention + + + align:start position:0% +Asian countries or largely pay attention +to these Asian countries because you + + align:start position:0% +to these Asian countries because you + + + align:start position:0% +to these Asian countries because you +never hear about United States and + + align:start position:0% +never hear about United States and + + + align:start position:0% +never hear about United States and +innovations here being just supposed to + + align:start position:0% +innovations here being just supposed to + + + align:start position:0% +innovations here being just supposed to +say innovations in Central or South + + align:start position:0% +say innovations in Central or South + + + align:start position:0% +say innovations in Central or South +America or even Eastern Europe and + + align:start position:0% +America or even Eastern Europe and + + + align:start position:0% +America or even Eastern Europe and +perhaps you know technological advances + + align:start position:0% +perhaps you know technological advances + + + align:start position:0% +perhaps you know technological advances +are not as impressive this sort of + + align:start position:0% +are not as impressive this sort of + + + align:start position:0% +are not as impressive this sort of +breadth of their compact is not as + + align:start position:0% +breadth of their compact is not as + + + align:start position:0% +breadth of their compact is not as +extensive and at the same time I think + + align:start position:0% +extensive and at the same time I think + + + align:start position:0% +extensive and at the same time I think +there has to be innovation occurring in + + align:start position:0% +there has to be innovation occurring in + + + align:start position:0% +there has to be innovation occurring in +other parts of the world they're not + + align:start position:0% +other parts of the world they're not + + + align:start position:0% +other parts of the world they're not +South Korea Germany China and Japan so + + align:start position:0% +South Korea Germany China and Japan so + + + align:start position:0% +South Korea Germany China and Japan so +to what extent is that sort of premise + + align:start position:0% +to what extent is that sort of premise + + + align:start position:0% +to what extent is that sort of premise +Don that kind of American paranoia that + + align:start position:0% +Don that kind of American paranoia that + + + align:start position:0% +Don that kind of American paranoia that +was highlighted in the Hughes piece + + align:start position:0% +was highlighted in the Hughes piece + + + align:start position:0% +was highlighted in the Hughes piece +against East Asia yeah I think maybe + + align:start position:0% +against East Asia yeah I think maybe + + + align:start position:0% +against East Asia yeah I think maybe +good follow-up is like we don't have + + align:start position:0% +good follow-up is like we don't have + + + align:start position:0% +good follow-up is like we don't have +enough counter example for you just cuz + + align:start position:0% +enough counter example for you just cuz + + + align:start position:0% +enough counter example for you just cuz +the press in the highlight and the + + align:start position:0% +the press in the highlight and the + + + align:start position:0% +the press in the highlight and the +attention hasn't been put there and I + + align:start position:0% +attention hasn't been put there and I + + + align:start position:0% +attention hasn't been put there and I +would hope yeah in central South + + align:start position:0% +would hope yeah in central South + + + align:start position:0% +would hope yeah in central South +American and these Eastern European + + align:start position:0% +American and these Eastern European + + + align:start position:0% +American and these Eastern European +countries they're seeing sort of the + + align:start position:0% +countries they're seeing sort of the + + + align:start position:0% +countries they're seeing sort of the +pervasiveness of these different models + + align:start position:0% +pervasiveness of these different models + + + align:start position:0% +pervasiveness of these different models +and there's no way they're not thinking + + align:start position:0% +and there's no way they're not thinking + + + align:start position:0% +and there's no way they're not thinking +about these things are adapting their + + align:start position:0% +about these things are adapting their + + + align:start position:0% +about these things are adapting their +mouths + + align:start position:0% +mouths + + + align:start position:0% +mouths +these sort of things I mean I noticed + + align:start position:0% +these sort of things I mean I noticed + + + align:start position:0% +these sort of things I mean I noticed +him at the I was at the Charlie has + + align:start position:0% +him at the I was at the Charlie has + + + align:start position:0% +him at the I was at the Charlie has +meeting last week and some of the people + + align:start position:0% +meeting last week and some of the people + + + align:start position:0% +meeting last week and some of the people +who were coming in from Russia we're + + align:start position:0% +who were coming in from Russia we're + + + align:start position:0% +who were coming in from Russia we're +saying that they had found that some of + + align:start position:0% +saying that they had found that some of + + + align:start position:0% +saying that they had found that some of +the advances that were just being noted + + align:start position:0% +the advances that were just being noted + + + align:start position:0% +the advances that were just being noted +in North America had been made in Russia + + align:start position:0% +in North America had been made in Russia + + + align:start position:0% +in North America had been made in Russia +think a decade ago and they had just + + align:start position:0% +think a decade ago and they had just + + + align:start position:0% +think a decade ago and they had just +never transferred to the International + + align:start position:0% +never transferred to the International + + + align:start position:0% +never transferred to the International +constant community because they were + + align:start position:0% +constant community because they were + + + align:start position:0% +constant community because they were +Russian centric and I thought that that + + align:start position:0% +Russian centric and I thought that that + + + align:start position:0% +Russian centric and I thought that that +was a really fascinating component about + + align:start position:0% +was a really fascinating component about + + + align:start position:0% +was a really fascinating component about +knowledge transfer its knowledge sharing + + align:start position:0% +knowledge transfer its knowledge sharing + + + align:start position:0% +knowledge transfer its knowledge sharing +because if our focus is only on + + align:start position:0% +because if our focus is only on + + + align:start position:0% +because if our focus is only on +competing with East Asian countries and + + align:start position:0% +competing with East Asian countries and + + + align:start position:0% +competing with East Asian countries and +Germany to what extent to our team it's + + align:start position:0% +Germany to what extent to our team it's + + + align:start position:0% +Germany to what extent to our team it's +an opportunity and it's a pain of paying + + align:start position:0% +an opportunity and it's a pain of paying + + + align:start position:0% +an opportunity and it's a pain of paying +attention to other countries that who + + align:start position:0% +attention to other countries that who + + + align:start position:0% +attention to other countries that who +might have interesting innovation cycles + + align:start position:0% +might have interesting innovation cycles + + + align:start position:0% +might have interesting innovation cycles +are products that we can learn + + align:start position:0% + + + + align:start position:0% + +well against to add on to that so I + + align:start position:0% +well against to add on to that so I + + + align:start position:0% +well against to add on to that so I +think the reason we look into age lot + + align:start position:0% +think the reason we look into age lot + + + align:start position:0% +think the reason we look into age lot +because ha + + align:start position:0% +because ha + + + align:start position:0% +because ha +they were like economies that weren't + + align:start position:0% +they were like economies that weren't + + + align:start position:0% +they were like economies that weren't +doing great and they pretty much like + + align:start position:0% +doing great and they pretty much like + + + align:start position:0% +doing great and they pretty much like +did a 360 turn like I wouldn't a be like + + align:start position:0% +did a 360 turn like I wouldn't a be like + + + align:start position:0% +did a 360 turn like I wouldn't a be like +in less than like 30 years and there's a + + align:start position:0% +in less than like 30 years and there's a + + + align:start position:0% +in less than like 30 years and there's a +lot of factors to it a lot of that was + + align:start position:0% +lot of factors to it a lot of that was + + + align:start position:0% +lot of factors to it a lot of that was +having very strong leaders going from + + align:start position:0% +having very strong leaders going from + + + align:start position:0% +having very strong leaders going from +periods of like not doing too well so + + align:start position:0% +periods of like not doing too well so + + + align:start position:0% +periods of like not doing too well so +they're more unified and then having a + + align:start position:0% +they're more unified and then having a + + + align:start position:0% +they're more unified and then having a +strong young population so most the + + align:start position:0% +strong young population so most the + + + align:start position:0% +strong young population so most the +countries that did really well next + + align:start position:0% +countries that did really well next + + + align:start position:0% +countries that did really well next +period like for the age pyramid like + + align:start position:0% +period like for the age pyramid like + + + align:start position:0% +period like for the age pyramid like +this it's a lot of young people very few + + align:start position:0% +this it's a lot of young people very few + + + align:start position:0% +this it's a lot of young people very few +old people and they were they were able + + align:start position:0% +old people and they were they were able + + + align:start position:0% +old people and they were they were able +to move very quickly and it's just + + align:start position:0% +to move very quickly and it's just + + + align:start position:0% +to move very quickly and it's just +because they have these strong leaders + + align:start position:0% +because they have these strong leaders + + + align:start position:0% +because they have these strong leaders +these other countries I think a lot of + + align:start position:0% +these other countries I think a lot of + + + align:start position:0% +these other countries I think a lot of +in Latin America they they don't have + + align:start position:0% +in Latin America they they don't have + + + align:start position:0% +in Latin America they they don't have +these kind of strong leaders or these + + align:start position:0% +these kind of strong leaders or these + + + align:start position:0% +these kind of strong leaders or these +periods that come up beforehand so there + + align:start position:0% +periods that come up beforehand so there + + + align:start position:0% +periods that come up beforehand so there +hasn't been rapid growth like + + align:start position:0% +hasn't been rapid growth like + + + align:start position:0% +hasn't been rapid growth like +innovations you know there has been a + + align:start position:0% +innovations you know there has been a + + + align:start position:0% +innovations you know there has been a +lot of innovations especially + + align:start position:0% +lot of innovations especially + + + align:start position:0% +lot of innovations especially +manufacturing Raziel parts of Mexico so + + align:start position:0% +manufacturing Raziel parts of Mexico so + + + align:start position:0% +manufacturing Raziel parts of Mexico so +I think it's just we haven't we paid too + + align:start position:0% +I think it's just we haven't we paid too + + + align:start position:0% +I think it's just we haven't we paid too +much attention to it but it doesn't seem + + align:start position:0% +much attention to it but it doesn't seem + + + align:start position:0% +much attention to it but it doesn't seem +like a threat but II thought I cut + + align:start position:0% +like a threat but II thought I cut + + + align:start position:0% +like a threat but II thought I cut +through some hoops so quickly that it + + align:start position:0% +through some hoops so quickly that it + + + align:start position:0% +through some hoops so quickly that it +does see you can see more than threat + + align:start position:0% +does see you can see more than threat + + + align:start position:0% +does see you can see more than threat +because if you look at Singapore like it + + align:start position:0% +because if you look at Singapore like it + + + align:start position:0% +because if you look at Singapore like it +was a country that was privileged not + + align:start position:0% +was a country that was privileged not + + + align:start position:0% +was a country that was privileged not +there they had a very strong leader was + + align:start position:0% +there they had a very strong leader was + + + align:start position:0% +there they had a very strong leader was +able to make quick decisions that are + + align:start position:0% +able to make quick decisions that are + + + align:start position:0% +able to make quick decisions that are +very strong and be very strong saying + + align:start position:0% +very strong and be very strong saying + + + align:start position:0% +very strong and be very strong saying +this is what I believe this is what I + + align:start position:0% +this is what I believe this is what I + + + align:start position:0% +this is what I believe this is what I +think we should do and then going after + + align:start position:0% +think we should do and then going after + + + align:start position:0% +think we should do and then going after +it and they were able to completely get + + align:start position:0% +it and they were able to completely get + + + align:start position:0% +it and they were able to completely get +just 180 their economy and I think we're + + align:start position:0% +just 180 their economy and I think we're + + + align:start position:0% +just 180 their economy and I think we're +also talking about like the role over + + align:start position:0% +also talking about like the role over + + + align:start position:0% +also talking about like the role over +government the US has like committees + + align:start position:0% +government the US has like committees + + + align:start position:0% +government the US has like committees +making decisions for innovation but + + align:start position:0% +making decisions for innovation but + + + align:start position:0% +making decisions for innovation but +actually Charlie Munger who everyone + + align:start position:0% +actually Charlie Munger who everyone + + + align:start position:0% +actually Charlie Munger who everyone +knows Warren Buffett right more or less + + align:start position:0% +knows Warren Buffett right more or less + + + align:start position:0% +knows Warren Buffett right more or less +Charlie Munger's his right-hand person + + align:start position:0% +Charlie Munger's his right-hand person + + + align:start position:0% +Charlie Munger's his right-hand person +and he says like in the past in general + + align:start position:0% +and he says like in the past in general + + + align:start position:0% +and he says like in the past in general +its countries do better when it was once + + align:start position:0% +its countries do better when it was once + + + align:start position:0% +its countries do better when it was once +very smart talented leader because they + + align:start position:0% +very smart talented leader because they + + + align:start position:0% +very smart talented leader because they +can make these hard decisions in the US + + align:start position:0% +can make these hard decisions in the US + + + align:start position:0% +can make these hard decisions in the US +we do have kind of like an executive but + + align:start position:0% +we do have kind of like an executive but + + + align:start position:0% +we do have kind of like an executive but +I think everybody in this table career + + align:start position:0% +I think everybody in this table career + + + align:start position:0% +I think everybody in this table career +that people don't really like say oh he + + align:start position:0% +that people don't really like say oh he + + + align:start position:0% +that people don't really like say oh he +said that we should do it so like the + + align:start position:0% +said that we should do it so like the + + + align:start position:0% +said that we should do it so like the +benefit is like these are very credible + + align:start position:0% +benefit is like these are very credible + + + align:start position:0% +benefit is like these are very credible +leaders that most of the time when they + + align:start position:0% +leaders that most of the time when they + + + align:start position:0% +leaders that most of the time when they +make it to that position for a bear from + + align:start position:0% +make it to that position for a bear from + + + align:start position:0% +make it to that position for a bear from +a downturn period are very talented and + + align:start position:0% +a downturn period are very talented and + + + align:start position:0% +a downturn period are very talented and +skilled and they that you make bets like + + align:start position:0% +skilled and they that you make bets like + + + align:start position:0% +skilled and they that you make bets like +they can make things are about the + + align:start position:0% +they can make things are about the + + + align:start position:0% +they can make things are about the +saying you know what this is an industry + + align:start position:0% +saying you know what this is an industry + + + align:start position:0% +saying you know what this is an industry +that's gonna grow very quickly let's put + + align:start position:0% +that's gonna grow very quickly let's put + + + align:start position:0% +that's gonna grow very quickly let's put +three people there's like three 30 40 + + align:start position:0% +three people there's like three 30 40 + + + align:start position:0% +three people there's like three 30 40 +companies that could do well but I think + + align:start position:0% +companies that could do well but I think + + + align:start position:0% +companies that could do well but I think +these three are really gonna win + + align:start position:0% +these three are really gonna win + + + align:start position:0% +these three are really gonna win +we're gonna put all our eggs on this + + align:start position:0% +we're gonna put all our eggs on this + + + align:start position:0% +we're gonna put all our eggs on this +basket and we're gonna do well and + + align:start position:0% +basket and we're gonna do well and + + + align:start position:0% +basket and we're gonna do well and +that's something that's very I guess + + align:start position:0% +that's something that's very I guess + + + align:start position:0% +that's something that's very I guess +alcohol on American because we're very + + align:start position:0% +alcohol on American because we're very + + + align:start position:0% +alcohol on American because we're very +much like everybody can go about it we + + align:start position:0% +much like everybody can go about it we + + + align:start position:0% +much like everybody can go about it we +want to leave opportunity but these + + align:start position:0% +want to leave opportunity but these + + + align:start position:0% +want to leave opportunity but these +countries do have this capability and + + align:start position:0% +countries do have this capability and + + + align:start position:0% +countries do have this capability and +they have parties shows that they can + + align:start position:0% +they have parties shows that they can + + + align:start position:0% +they have parties shows that they can +grow so quickly versus other countries I + + align:start position:0% +grow so quickly versus other countries I + + + align:start position:0% +grow so quickly versus other countries I +think I think another thing too is like + + align:start position:0% +think I think another thing too is like + + + align:start position:0% +think I think another thing too is like +Latin America Russia we still see a lot + + align:start position:0% +Latin America Russia we still see a lot + + + align:start position:0% +Latin America Russia we still see a lot +of corruption these other countries to + + align:start position:0% +of corruption these other countries to + + + align:start position:0% +of corruption these other countries to +get rid of it like Singapore what Lee + + align:start position:0% +get rid of it like Singapore what Lee + + + align:start position:0% +get rid of it like Singapore what Lee +Kuan Yew did we'll say okay I'm gonna + + align:start position:0% +Kuan Yew did we'll say okay I'm gonna + + + align:start position:0% +Kuan Yew did we'll say okay I'm gonna +pay everyone about twice as much but if + + align:start position:0% +pay everyone about twice as much but if + + + align:start position:0% +pay everyone about twice as much but if +I find out that you're being corrupt you + + align:start position:0% +I find out that you're being corrupt you + + + align:start position:0% +I find out that you're being corrupt you +guys are pretty much done it was like a + + align:start position:0% +guys are pretty much done it was like a + + + align:start position:0% +guys are pretty much done it was like a +death penalty or it was like very severe + + align:start position:0% +death penalty or it was like very severe + + + align:start position:0% +death penalty or it was like very severe +sanctions but also severe sanctions upon + + align:start position:0% +sanctions but also severe sanctions upon + + + align:start position:0% +sanctions but also severe sanctions upon +them and their families so that's a + + align:start position:0% +them and their families so that's a + + + align:start position:0% +them and their families so that's a +completely different way of going about + + align:start position:0% +completely different way of going about + + + align:start position:0% +completely different way of going about +it + + align:start position:0% +it + + + align:start position:0% +it +so I think we did just all see other + + align:start position:0% +so I think we did just all see other + + + align:start position:0% +so I think we did just all see other +pensions a threat even though they have + + align:start position:0% +pensions a threat even though they have + + + align:start position:0% +pensions a threat even though they have +good capabilities but these funders + + align:start position:0% +good capabilities but these funders + + + align:start position:0% +good capabilities but these funders +didn't do amazing things + + align:start position:0% +didn't do amazing things + + + align:start position:0% +didn't do amazing things +30 20 years that can but you could also + + align:start position:0% +30 20 years that can but you could also + + + align:start position:0% +30 20 years that can but you could also +debate that was because there was very + + align:start position:0% +debate that was because there was very + + + align:start position:0% +debate that was because there was very +young populations because also Japan and + + align:start position:0% +young populations because also Japan and + + + align:start position:0% +young populations because also Japan and +South Korea had Steck nations right + + align:start position:0% +South Korea had Steck nations right + + + align:start position:0% +South Korea had Steck nations right +after so and finals like Martina it's a + + align:start position:0% +after so and finals like Martina it's a + + + align:start position:0% +after so and finals like Martina it's a +very it's a very political economy + + align:start position:0% +very it's a very political economy + + + align:start position:0% +very it's a very political economy +perspective right and I you know going + + align:start position:0% +perspective right and I you know going + + + align:start position:0% +perspective right and I you know going +back to some of the points that Matt was + + align:start position:0% +back to some of the points that Matt was + + + align:start position:0% +back to some of the points that Matt was +making earlier I think the central Glenn + + align:start position:0% +making earlier I think the central Glenn + + + align:start position:0% +making earlier I think the central Glenn +Forum argument is that that may get you + + align:start position:0% +Forum argument is that that may get you + + + align:start position:0% +Forum argument is that that may get you +a fair distance for a period of time as + + align:start position:0% +a fair distance for a period of time as + + + align:start position:0% +a fair distance for a period of time as +you're getting to the frontier but then + + align:start position:0% +you're getting to the frontier but then + + + align:start position:0% +you're getting to the frontier but then +when you get to the frontier you better + + align:start position:0% +when you get to the frontier you better + + + align:start position:0% +when you get to the frontier you better +figure out ain't more bottom-up more + + align:start position:0% +figure out ain't more bottom-up more + + + align:start position:0% +figure out ain't more bottom-up more +collaborative kind of model if you want + + align:start position:0% +collaborative kind of model if you want + + + align:start position:0% +collaborative kind of model if you want +to keep the ideas if you need that big + + align:start position:0% +to keep the ideas if you need that big + + + align:start position:0% +to keep the ideas if you need that big +mix of ideas that's going to enable you + + align:start position:0% +mix of ideas that's going to enable you + + + align:start position:0% +mix of ideas that's going to enable you +to go to a series of the next things + + align:start position:0% +to go to a series of the next things + + + align:start position:0% +to go to a series of the next things +that's that's phone's argument and that + + align:start position:0% +that's that's phone's argument and that + + + align:start position:0% +that's that's phone's argument and that +his point is that just hand really had + + align:start position:0% +his point is that just hand really had + + + align:start position:0% +his point is that just hand really had +to reorganize and since innovation + + align:start position:0% +to reorganize and since innovation + + + align:start position:0% +to reorganize and since innovation +system away from the political economy + + align:start position:0% +system away from the political economy + + + align:start position:0% +system away from the political economy +kind of approach to describing or to + + align:start position:0% +kind of approach to describing or to + + + align:start position:0% +kind of approach to describing or to +really a very different organization + + align:start position:0% +really a very different organization + + + align:start position:0% +really a very different organization +when it reached that you know innovation + + align:start position:0% +when it reached that you know innovation + + + align:start position:0% +when it reached that you know innovation +competition but it's + + align:start position:0% + + + + align:start position:0% + +mr. Anya this wants to your question you + + align:start position:0% +mr. Anya this wants to your question you + + + align:start position:0% +mr. Anya this wants to your question you +know I want to go back to what we talked + + align:start position:0% +know I want to go back to what we talked + + + align:start position:0% +know I want to go back to what we talked +about in the first class for a long time + + align:start position:0% +about in the first class for a long time + + + align:start position:0% +about in the first class for a long time +we thought that this innovation system + + align:start position:0% +we thought that this innovation system + + + align:start position:0% +we thought that this innovation system +stuff was the wing which the rich + + align:start position:0% +stuff was the wing which the rich + + + align:start position:0% +stuff was the wing which the rich +countries got Richmond right it was just + + align:start position:0% +countries got Richmond right it was just + + + align:start position:0% +countries got Richmond right it was just +a way to build further wealth you know + + align:start position:0% +a way to build further wealth you know + + + align:start position:0% +a way to build further wealth you know +relatively modest number of countries + + align:start position:0% +relatively modest number of countries + + + align:start position:0% +relatively modest number of countries +that figured out how to dominate and + + align:start position:0% +that figured out how to dominate and + + + align:start position:0% +that figured out how to dominate and +leave these these innovation systems but + + align:start position:0% +leave these these innovation systems but + + + align:start position:0% +leave these these innovation systems but +then other things start happening right + + align:start position:0% +then other things start happening right + + + align:start position:0% +then other things start happening right +Korea comes up from being totally + + align:start position:0% +Korea comes up from being totally + + + align:start position:0% +Korea comes up from being totally +destroyed right Taiwan somewhat you know + + align:start position:0% +destroyed right Taiwan somewhat you know + + + align:start position:0% +destroyed right Taiwan somewhat you know +economies like India which is obviously + + align:start position:0% +economies like India which is obviously + + + align:start position:0% +economies like India which is obviously +one of the forests of the world is able + + align:start position:0% +one of the forests of the world is able + + + align:start position:0% +one of the forests of the world is able +to start building a very significant + + align:start position:0% +to start building a very significant + + + align:start position:0% +to start building a very significant +middle class and you know China is the + + align:start position:0% +middle class and you know China is the + + + align:start position:0% +middle class and you know China is the +latest element in the story in other + + align:start position:0% +latest element in the story in other + + + align:start position:0% +latest element in the story in other +words an innovation based growth model + + align:start position:0% +words an innovation based growth model + + + align:start position:0% +words an innovation based growth model +can be pervasive and work in the + + align:start position:0% +can be pervasive and work in the + + + align:start position:0% +can be pervasive and work in the +development world now we've managed to + + align:start position:0% +development world now we've managed to + + + align:start position:0% +development world now we've managed to +translate that a pretty interesting + + align:start position:0% +translate that a pretty interesting + + + align:start position:0% +translate that a pretty interesting +scale you know get parts of Asia + + align:start position:0% +scale you know get parts of Asia + + + align:start position:0% +scale you know get parts of Asia +we haven't you're exactly like we + + align:start position:0% +we haven't you're exactly like we + + + align:start position:0% +we haven't you're exactly like we +haven't translated the possible + + align:start position:0% +haven't translated the possible + + + align:start position:0% +haven't translated the possible +exception of Brazil into a pervasive + + align:start position:0% +exception of Brazil into a pervasive + + + align:start position:0% +exception of Brazil into a pervasive +monogamous and so it's you know one of + + align:start position:0% +monogamous and so it's you know one of + + + align:start position:0% +monogamous and so it's you know one of +the options for doing a paper in this + + align:start position:0% +the options for doing a paper in this + + + align:start position:0% +the options for doing a paper in this +course is to look at national and other + + align:start position:0% +course is to look at national and other + + + align:start position:0% +course is to look at national and other +national innovation systems that dive + + align:start position:0% +national innovation systems that dive + + + align:start position:0% +national innovation systems that dive +into them and I really hope somebody + + align:start position:0% +into them and I really hope somebody + + + align:start position:0% +into them and I really hope somebody +will pursue this it's you know we don't + + align:start position:0% +will pursue this it's you know we don't + + + align:start position:0% +will pursue this it's you know we don't +particularly focus on this in this class + + align:start position:0% +particularly focus on this in this class + + + align:start position:0% +particularly focus on this in this class +so that we could but the Brazil stories + + align:start position:0% +so that we could but the Brazil stories + + + align:start position:0% +so that we could but the Brazil stories +absolutely fast and a remarkable story + + align:start position:0% +absolutely fast and a remarkable story + + + align:start position:0% +absolutely fast and a remarkable story +obviously they're in a fair amount of + + align:start position:0% +obviously they're in a fair amount of + + + align:start position:0% +obviously they're in a fair amount of +economic trouble from macro factors but + + align:start position:0% +economic trouble from macro factors but + + + align:start position:0% +economic trouble from macro factors but +nonetheless it's a very promising story + + align:start position:0% +nonetheless it's a very promising story + + + align:start position:0% +nonetheless it's a very promising story +yeah I think there are others and there + + align:start position:0% +yeah I think there are others and there + + + align:start position:0% +yeah I think there are others and there +are other parts of the culture so + + align:start position:0% +are other parts of the culture so + + + align:start position:0% +are other parts of the culture so +putting a much resume is longer talking + + align:start position:0% +putting a much resume is longer talking + + + align:start position:0% +putting a much resume is longer talking +about this + + align:start position:0% +about this + + + align:start position:0% +about this +I remember that there's sort of major + + align:start position:0% +I remember that there's sort of major + + + align:start position:0% +I remember that there's sort of major +airplane companies or if I manufacture + + align:start position:0% +airplane companies or if I manufacture + + + align:start position:0% +airplane companies or if I manufacture +so you think like Boeing I throw up on + + align:start position:0% +so you think like Boeing I throw up on + + + align:start position:0% +so you think like Boeing I throw up on +when this morning ever air yeah exactly + + align:start position:0% +when this morning ever air yeah exactly + + + align:start position:0% +when this morning ever air yeah exactly +and there Jase + + align:start position:0% +and there Jase + + + align:start position:0% +and there Jase +and they're from Brazil and basic result + + align:start position:0% +and they're from Brazil and basic result + + + align:start position:0% +and they're from Brazil and basic result +and they basically are really important + + align:start position:0% +and they basically are really important + + + align:start position:0% +and they basically are really important +sort of now and will be important in the + + align:start position:0% +sort of now and will be important in the + + + align:start position:0% +sort of now and will be important in the +coming years because going in everyone's + + align:start position:0% +coming years because going in everyone's + + + align:start position:0% +coming years because going in everyone's +dominate he's like very large big + + align:start position:0% +dominate he's like very large big + + + align:start position:0% +dominate he's like very large big +airplanes looks like 787's like these + + align:start position:0% +airplanes looks like 787's like these + + + align:start position:0% +airplanes looks like 787's like these +very large aircraft this sort of all + + align:start position:0% +very large aircraft this sort of all + + + align:start position:0% +very large aircraft this sort of all +tend to get bigger in scale Embraer is + + align:start position:0% +tend to get bigger in scale Embraer is + + + align:start position:0% +tend to get bigger in scale Embraer is +important because they focus on sort of + + align:start position:0% +important because they focus on sort of + + + align:start position:0% +important because they focus on sort of +shorter flight distances with smaller + + align:start position:0% +shorter flight distances with smaller + + + align:start position:0% +shorter flight distances with smaller +aircraft and developing out of that + + align:start position:0% +aircraft and developing out of that + + + align:start position:0% +aircraft and developing out of that +market but I just looked and they were + + align:start position:0% +market but I just looked and they were + + + align:start position:0% +market but I just looked and they were +actually in the 90s sort of this + + align:start position:0% +actually in the 90s sort of this + + + align:start position:0% +actually in the 90s sort of this +public-private partnership so came while + + align:start position:0% +public-private partnership so came while + + + align:start position:0% +public-private partnership so came while +Brazil is looking at sort of shorter + + align:start position:0% +Brazil is looking at sort of shorter + + + align:start position:0% +Brazil is looking at sort of shorter +distance flights and doing that a lot + + align:start position:0% +distance flights and doing that a lot + + + align:start position:0% +distance flights and doing that a lot +better but it does come sort of this + + align:start position:0% +better but it does come sort of this + + + align:start position:0% +better but it does come sort of this +pursue after pioneer and I think they're + + align:start position:0% +pursue after pioneer and I think they're + + + align:start position:0% +pursue after pioneer and I think they're +now probably shifting to build more + + align:start position:0% +now probably shifting to build more + + + align:start position:0% +now probably shifting to build more +aircrafts there's instead of like + + align:start position:0% +aircrafts there's instead of like + + + align:start position:0% +aircrafts there's instead of like +copying smaller aircraft designs they're + + align:start position:0% +copying smaller aircraft designs they're + + + align:start position:0% +copying smaller aircraft designs they're +sort of having to now become the + + align:start position:0% +sort of having to now become the + + + align:start position:0% +sort of having to now become the +pioneers and like really start building + + align:start position:0% +pioneers and like really start building + + + align:start position:0% +pioneers and like really start building +new just like smaller scale aircraft and + + align:start position:0% +new just like smaller scale aircraft and + + + align:start position:0% +new just like smaller scale aircraft and +take that market and Brazil is + + align:start position:0% +take that market and Brazil is + + + align:start position:0% +take that market and Brazil is +interesting just cuz they were allowed + + align:start position:0% +interesting just cuz they were allowed + + + align:start position:0% +interesting just cuz they were allowed +to do that and I don't know what sort of + + align:start position:0% +to do that and I don't know what sort of + + + align:start position:0% +to do that and I don't know what sort of +factors played into them being allowed + + align:start position:0% +factors played into them being allowed + + + align:start position:0% +factors played into them being allowed +to initially start that public-private + + align:start position:0% +to initially start that public-private + + + align:start position:0% +to initially start that public-private +partnership and about the 90s when + + align:start position:0% +partnership and about the 90s when + + + align:start position:0% +partnership and about the 90s when +Embraer started but I think now they're + + align:start position:0% +Embraer started but I think now they're + + + align:start position:0% +Embraer started but I think now they're +probably gonna have to ship pretty + + align:start position:0% +probably gonna have to ship pretty + + + align:start position:0% +probably gonna have to ship pretty +drastically radically and looking to do + + align:start position:0% +drastically radically and looking to do + + + align:start position:0% +drastically radically and looking to do +that so that's a place I don't think + + align:start position:0% +that so that's a place I don't think + + + align:start position:0% +that so that's a place I don't think +we've touched yet is presumably I think + + align:start position:0% +we've touched yet is presumably I think + + + align:start position:0% +we've touched yet is presumably I think +there was a lot of pushback from their + + align:start position:0% +there was a lot of pushback from their + + + align:start position:0% +there was a lot of pushback from their +competitors for that Emperor was getting + + align:start position:0% +competitors for that Emperor was getting + + + align:start position:0% +competitors for that Emperor was getting +unfair treatment from their government + + align:start position:0% +unfair treatment from their government + + + align:start position:0% +unfair treatment from their government +in terms of like other trade agreements + + align:start position:0% +in terms of like other trade agreements + + + align:start position:0% +in terms of like other trade agreements +and donar specifically but it does call + + align:start position:0% +and donar specifically but it does call + + + align:start position:0% +and donar specifically but it does call +a Chris Chris I'm going to shift over to + + align:start position:0% +a Chris Chris I'm going to shift over to + + + align:start position:0% +a Chris Chris I'm going to shift over to +you and we're gonna do let sue Kim so I + + align:start position:0% +you and we're gonna do let sue Kim so I + + + align:start position:0% +you and we're gonna do let sue Kim so I +think they'll really give a good + + align:start position:0% +think they'll really give a good + + + align:start position:0% +think they'll really give a good +background on the article but you don't + + align:start position:0% +background on the article but you don't + + + align:start position:0% +background on the article but you don't +have to say that but to go into a bit + + align:start position:0% +have to say that but to go into a bit + + + align:start position:0% +have to say that but to go into a bit +more about the process of how Korea kind + + align:start position:0% +more about the process of how Korea kind + + + align:start position:0% +more about the process of how Korea kind +of came up to speed on the forefront of + + align:start position:0% +of came up to speed on the forefront of + + + align:start position:0% +of came up to speed on the forefront of +the innovation frontier at that time + + align:start position:0% +the innovation frontier at that time + + + align:start position:0% +the innovation frontier at that time +they really went through this process of + + align:start position:0% +they really went through this process of + + + align:start position:0% +they really went through this process of +imitating what was out there and then + + align:start position:0% +imitating what was out there and then + + + align:start position:0% +imitating what was out there and then +from that basis going on to innovate and + + align:start position:0% +from that basis going on to innovate and + + + align:start position:0% +from that basis going on to innovate and +do their own R&D + + align:start position:0% +do their own R&D + + + align:start position:0% +do their own R&D +in Korea + + align:start position:0% +in Korea + + + align:start position:0% +in Korea +more advances for those problems those + + align:start position:0% +more advances for those problems those + + + align:start position:0% +more advances for those problems those +products and this trend was really + + align:start position:0% +products and this trend was really + + + align:start position:0% +products and this trend was really +supported by those clothes intertwine + + align:start position:0% +supported by those clothes intertwine + + + align:start position:0% +supported by those clothes intertwine +partnerships and almost interdependence + + align:start position:0% +partnerships and almost interdependence + + + align:start position:0% +partnerships and almost interdependence +between the government and the tables + + align:start position:0% +between the government and the tables + + + align:start position:0% +between the government and the tables +and the table still exists like even to + + align:start position:0% +and the table still exists like even to + + + align:start position:0% +and the table still exists like even to +this day they're really like family + + align:start position:0% +this day they're really like family + + + align:start position:0% +this day they're really like family +centric dynastic corporations like the + + align:start position:0% +centric dynastic corporations like the + + + align:start position:0% +centric dynastic corporations like the +Lee family has controlled Samsung for + + align:start position:0% +Lee family has controlled Samsung for + + + align:start position:0% +Lee family has controlled Samsung for +however long they've been in business + + align:start position:0% +however long they've been in business + + + align:start position:0% +however long they've been in business +and that centralist kind of government + + align:start position:0% +and that centralist kind of government + + + align:start position:0% +and that centralist kind of government +support and structure has really allowed + + align:start position:0% +support and structure has really allowed + + + align:start position:0% +support and structure has really allowed +them to enter really high capital + + align:start position:0% +them to enter really high capital + + + align:start position:0% +them to enter really high capital +industries and really get to the front + + align:start position:0% +industries and really get to the front + + + align:start position:0% +industries and really get to the front +really quickly as we've been discussing + + align:start position:0% +really quickly as we've been discussing + + + align:start position:0% +really quickly as we've been discussing +has been a factor also in Japan so just + + align:start position:0% +has been a factor also in Japan so just + + + align:start position:0% +has been a factor also in Japan so just +focusing on this right now we discussed + + align:start position:0% +focusing on this right now we discussed + + + align:start position:0% +focusing on this right now we discussed +how you know the focus on the + + align:start position:0% +how you know the focus on the + + + align:start position:0% +how you know the focus on the +partnerships between the table and the + + align:start position:0% +partnerships between the table and the + + + align:start position:0% +partnerships between the table and the +government has kind of stymied the + + align:start position:0% +government has kind of stymied the + + + align:start position:0% +government has kind of stymied the +ability of SMEs and the smaller funds to + + align:start position:0% +ability of SMEs and the smaller funds to + + + align:start position:0% +ability of SMEs and the smaller funds to +enter the space so one question that + + align:start position:0% +enter the space so one question that + + + align:start position:0% +enter the space so one question that +someone had was like how can the come to + + align:start position:0% +someone had was like how can the come to + + + align:start position:0% +someone had was like how can the come to +the country catch up the economy and + + align:start position:0% +the country catch up the economy and + + + align:start position:0% +the country catch up the economy and +foster both aspects of you know the + + align:start position:0% +foster both aspects of you know the + + + align:start position:0% +foster both aspects of you know the +larger corporations as well as the + + align:start position:0% +larger corporations as well as the + + + align:start position:0% +larger corporations as well as the +smaller businesses like do they have to + + align:start position:0% +smaller businesses like do they have to + + + align:start position:0% +smaller businesses like do they have to +partition funds kind of have different + + align:start position:0% +partition funds kind of have different + + + align:start position:0% +partition funds kind of have different +initiatives or approaches for both kind + + align:start position:0% +initiatives or approaches for both kind + + + align:start position:0% +initiatives or approaches for both kind +of sectors or how do you guys think they + + align:start position:0% +of sectors or how do you guys think they + + + align:start position:0% +of sectors or how do you guys think they +should approach that kind of growth + + align:start position:0% + + + + align:start position:0% + +I guess it seems like the tables are + + align:start position:0% +I guess it seems like the tables are + + + align:start position:0% +I guess it seems like the tables are +kind of focused in specific industries + + align:start position:0% +kind of focused in specific industries + + + align:start position:0% +kind of focused in specific industries +right now like construction and + + align:start position:0% +right now like construction and + + + align:start position:0% +right now like construction and +electronics so it's probably going to be + + align:start position:0% +electronics so it's probably going to be + + + align:start position:0% +electronics so it's probably going to be +harder to get smaller firms to get a + + align:start position:0% +harder to get smaller firms to get a + + + align:start position:0% +harder to get smaller firms to get a +footing in those industries so my + + align:start position:0% +footing in those industries so my + + + align:start position:0% +footing in those industries so my +opinion to make more sense to kind of + + align:start position:0% +opinion to make more sense to kind of + + + align:start position:0% +opinion to make more sense to kind of +pick something new and focus attention + + align:start position:0% +pick something new and focus attention + + + align:start position:0% +pick something new and focus attention +on developing those industries so I + + align:start position:0% +on developing those industries so I + + + align:start position:0% +on developing those industries so I +don't make this me get like I start up + + align:start position:0% +don't make this me get like I start up + + + align:start position:0% +don't make this me get like I start up +they can compete with Hyundai but maybe + + align:start position:0% +they can compete with Hyundai but maybe + + + align:start position:0% +they can compete with Hyundai but maybe +there's something and energy or IT that + + align:start position:0% +there's something and energy or IT that + + + align:start position:0% +there's something and energy or IT that +they have to grow more or maybe even + + align:start position:0% +they have to grow more or maybe even + + + align:start position:0% +they have to grow more or maybe even +focus SM needs are more domestic affairs + + align:start position:0% +focus SM needs are more domestic affairs + + + align:start position:0% +focus SM needs are more domestic affairs +like I don't know if agriculture or some + + align:start position:0% +like I don't know if agriculture or some + + + align:start position:0% +like I don't know if agriculture or some +industries in Korea might be a good + + align:start position:0% +industries in Korea might be a good + + + align:start position:0% +industries in Korea might be a good +target for them I think you just need to + + align:start position:0% +target for them I think you just need to + + + align:start position:0% +target for them I think you just need to +offer governmental support and financial + + align:start position:0% +offer governmental support and financial + + + align:start position:0% +offer governmental support and financial +protections probably a little bit + + align:start position:0% +protections probably a little bit + + + align:start position:0% +protections probably a little bit +different than obviously the tables need + + align:start position:0% +different than obviously the tables need + + + align:start position:0% +different than obviously the tables need +or don't need but you just have to + + align:start position:0% +or don't need but you just have to + + + align:start position:0% +or don't need but you just have to +decide what's the scale that you're + + align:start position:0% +decide what's the scale that you're + + + align:start position:0% +decide what's the scale that you're +trying to look and build that if you're + + align:start position:0% +trying to look and build that if you're + + + align:start position:0% +trying to look and build that if you're +trying to build a circus smaller sectors + + align:start position:0% +trying to build a circus smaller sectors + + + align:start position:0% +trying to build a circus smaller sectors +and my diner develop like agriculture + + align:start position:0% +and my diner develop like agriculture + + + align:start position:0% +and my diner develop like agriculture +for example I just have to look a little + + align:start position:0% +for example I just have to look a little + + + align:start position:0% +for example I just have to look a little +bit smaller I'm like it's trying to + + align:start position:0% +bit smaller I'm like it's trying to + + + align:start position:0% +bit smaller I'm like it's trying to +cater to you know one or two or three + + align:start position:0% +cater to you know one or two or three + + + align:start position:0% +cater to you know one or two or three +Chabot companies offer + + align:start position:0% + + + + align:start position:0% + +Chris do you think that from your + + align:start position:0% +Chris do you think that from your + + + align:start position:0% +Chris do you think that from your +reading of Kennedy do you agree with him + + align:start position:0% +reading of Kennedy do you agree with him + + + align:start position:0% +reading of Kennedy do you agree with him +that Korea needs to foster an SME + + align:start position:0% +that Korea needs to foster an SME + + + align:start position:0% +that Korea needs to foster an SME +startup kind of community you mean in + + align:start position:0% +startup kind of community you mean in + + + align:start position:0% +startup kind of community you mean in +the context of present-day present-day + + align:start position:0% +the context of present-day present-day + + + align:start position:0% +the context of present-day present-day +with is that can be an enhancement to + + align:start position:0% +with is that can be an enhancement to + + + align:start position:0% +with is that can be an enhancement to +Korea's innovation capable or do they do + + align:start position:0% +Korea's innovation capable or do they do + + + align:start position:0% +Korea's innovation capable or do they do +they really need to do this what do you + + align:start position:0% +they really need to do this what do you + + + align:start position:0% +they really need to do this what do you +think personally I think their structure + + align:start position:0% +think personally I think their structure + + + align:start position:0% +think personally I think their structure +that really focuses on the bigger + + align:start position:0% +that really focuses on the bigger + + + align:start position:0% +that really focuses on the bigger +corporations and their impact and their + + align:start position:0% +corporations and their impact and their + + + align:start position:0% +corporations and their impact and their +ability to really compete globally has + + align:start position:0% +ability to really compete globally has + + + align:start position:0% +ability to really compete globally has +been working so I do think that the + + align:start position:0% +been working so I do think that the + + + align:start position:0% +been working so I do think that the +corporation kind of push has been + + align:start position:0% +corporation kind of push has been + + + align:start position:0% +corporation kind of push has been +successful whether SM ease should be + + align:start position:0% +successful whether SM ease should be + + + align:start position:0% +successful whether SM ease should be +sort of supported from the government I + + align:start position:0% +sort of supported from the government I + + + align:start position:0% +sort of supported from the government I +think it's worth kind of exploring I do + + align:start position:0% +think it's worth kind of exploring I do + + + align:start position:0% +think it's worth kind of exploring I do +think that kind of finding them Anish is + + align:start position:0% +think that kind of finding them Anish is + + + align:start position:0% +think that kind of finding them Anish is +really important because there's kind of + + align:start position:0% +really important because there's kind of + + + align:start position:0% +really important because there's kind of +no point or kind of redundant for them + + align:start position:0% +no point or kind of redundant for them + + + align:start position:0% +no point or kind of redundant for them +to try to enter industries that the + + align:start position:0% +to try to enter industries that the + + + align:start position:0% +to try to enter industries that the +corporations have a hold on to the first + + align:start position:0% +corporations have a hold on to the first + + + align:start position:0% +corporations have a hold on to the first +digital camera but because of the way + + align:start position:0% +digital camera but because of the way + + + align:start position:0% +digital camera but because of the way +their supply chain and their current + + align:start position:0% +their supply chain and their current + + + align:start position:0% +their supply chain and their current +business was they couldn't they didn't + + align:start position:0% +business was they couldn't they didn't + + + align:start position:0% +business was they couldn't they didn't +want to make a factory be the ruler of + + align:start position:0% +want to make a factory be the ruler of + + + align:start position:0% +want to make a factory be the ruler of +existing business so danger of having a + + align:start position:0% +existing business so danger of having a + + + align:start position:0% +existing business so danger of having a +too big of giant is in order to innovate + + align:start position:0% +too big of giant is in order to innovate + + + align:start position:0% +too big of giant is in order to innovate +it takes so much effort on them that + + align:start position:0% +it takes so much effort on them that + + + align:start position:0% +it takes so much effort on them that +they won't do it and if your economy is + + align:start position:0% +they won't do it and if your economy is + + + align:start position:0% +they won't do it and if your economy is +based off of that and based on those + + align:start position:0% +based off of that and based on those + + + align:start position:0% +based off of that and based on those +four giants especially with rapid techno + + align:start position:0% +four giants especially with rapid techno + + + align:start position:0% +four giants especially with rapid techno +techno much motivation you really don't + + align:start position:0% +techno much motivation you really don't + + + align:start position:0% +techno much motivation you really don't +want to be in that position so have you + + align:start position:0% +want to be in that position so have you + + + align:start position:0% +want to be in that position so have you +got any special medicine yeah I kind of + + align:start position:0% +got any special medicine yeah I kind of + + + align:start position:0% +got any special medicine yeah I kind of +want to hit on both of those so with the + + align:start position:0% +want to hit on both of those so with the + + + align:start position:0% +want to hit on both of those so with the +cable over just SME the structure in + + align:start position:0% +cable over just SME the structure in + + + align:start position:0% +cable over just SME the structure in +Korea I'm wondering are the are the + + align:start position:0% +Korea I'm wondering are the are the + + + align:start position:0% +Korea I'm wondering are the are the +major major legacy sort of corporations + + align:start position:0% +major major legacy sort of corporations + + + align:start position:0% +major major legacy sort of corporations +are they profitable enough and large + + align:start position:0% +are they profitable enough and large + + + align:start position:0% +are they profitable enough and large +enough to be self-sufficient they don't + + align:start position:0% +enough to be self-sufficient they don't + + + align:start position:0% +enough to be self-sufficient they don't +really need the input from the + + align:start position:0% +really need the input from the + + + align:start position:0% +really need the input from the +government as they did decades ago could + + align:start position:0% +government as they did decades ago could + + + align:start position:0% +government as they did decades ago could +the government focus more on SMEs and + + align:start position:0% +the government focus more on SMEs and + + + align:start position:0% +the government focus more on SMEs and +would that be a more strategic way to go + + align:start position:0% +would that be a more strategic way to go + + + align:start position:0% +would that be a more strategic way to go +about things or do they + + align:start position:0% +about things or do they + + + align:start position:0% +about things or do they +have a situation in Korea I don't I + + align:start position:0% +have a situation in Korea I don't I + + + align:start position:0% +have a situation in Korea I don't I +don't know I haven't only been there + + align:start position:0% +don't know I haven't only been there + + + align:start position:0% +don't know I haven't only been there +once it was only for about a week so I + + align:start position:0% +once it was only for about a week so I + + + align:start position:0% +once it was only for about a week so I +don't really know do they have the + + align:start position:0% +don't really know do they have the + + + align:start position:0% +don't really know do they have the +situation similar to what I think we + + align:start position:0% +situation similar to what I think we + + + align:start position:0% +situation similar to what I think we +faced in the United States where we yes + + align:start position:0% +faced in the United States where we yes + + + align:start position:0% +faced in the United States where we yes +we have legacy technologies and sectors + + align:start position:0% +we have legacy technologies and sectors + + + align:start position:0% +we have legacy technologies and sectors +that are probably self-sufficient at + + align:start position:0% +that are probably self-sufficient at + + + align:start position:0% +that are probably self-sufficient at +this point and highly profitable but we + + align:start position:0% +this point and highly profitable but we + + + align:start position:0% +this point and highly profitable but we +are so ingrained the government still + + align:start position:0% +are so ingrained the government still + + + align:start position:0% +are so ingrained the government still +gives subsidies to fossil fuel + + align:start position:0% +gives subsidies to fossil fuel + + + align:start position:0% +gives subsidies to fossil fuel +industries subsidize their R&D and that + + align:start position:0% +industries subsidize their R&D and that + + + align:start position:0% +industries subsidize their R&D and that +although they shouldn't necessarily need + + align:start position:0% +although they shouldn't necessarily need + + + align:start position:0% +although they shouldn't necessarily need +that it's it's like that and they they + + align:start position:0% +that it's it's like that and they they + + + align:start position:0% +that it's it's like that and they they +have power so they can continue to get + + align:start position:0% +have power so they can continue to get + + + align:start position:0% +have power so they can continue to get +those funds so what is the situation in + + align:start position:0% +those funds so what is the situation in + + + align:start position:0% +those funds so what is the situation in +Korea today are they ingrained and can't + + align:start position:0% +Korea today are they ingrained and can't + + + align:start position:0% +Korea today are they ingrained and can't +really separate at this point or what I + + align:start position:0% +really separate at this point or what I + + + align:start position:0% +really separate at this point or what I +know + + align:start position:0% +know + + + align:start position:0% +know +definitely it's still very ingrained a + + align:start position:0% +definitely it's still very ingrained a + + + align:start position:0% +definitely it's still very ingrained a +lot of the Corporations have I don't + + align:start position:0% +lot of the Corporations have I don't + + + align:start position:0% +lot of the Corporations have I don't +know if it's soap I don't think it's + + align:start position:0% +know if it's soap I don't think it's + + + align:start position:0% +know if it's soap I don't think it's +corruption necessarily but close + + align:start position:0% +corruption necessarily but close + + + align:start position:0% +corruption necessarily but close +political ties to the government and + + align:start position:0% +political ties to the government and + + + align:start position:0% +political ties to the government and +power so it might be difficult I think + + align:start position:0% +power so it might be difficult I think + + + align:start position:0% +power so it might be difficult I think +to separate the two and going back to + + align:start position:0% +to separate the two and going back to + + + align:start position:0% +to separate the two and going back to +the point of whether SMEs could be like + + align:start position:0% +the point of whether SMEs could be like + + + align:start position:0% +the point of whether SMEs could be like +on the rise in the future I think it's + + align:start position:0% +on the rise in the future I think it's + + + align:start position:0% +on the rise in the future I think it's +also a cultural difference because in my + + align:start position:0% +also a cultural difference because in my + + + align:start position:0% +also a cultural difference because in my +Korean and Asian culture it's often like + + align:start position:0% +Korean and Asian culture it's often like + + + align:start position:0% +Korean and Asian culture it's often like +more traditional and that it's very + + align:start position:0% +more traditional and that it's very + + + align:start position:0% +more traditional and that it's very +prestigious obviously to go into these + + align:start position:0% +prestigious obviously to go into these + + + align:start position:0% +prestigious obviously to go into these +very developed and long-standing + + align:start position:0% +very developed and long-standing + + + align:start position:0% +very developed and long-standing +companies and there's not so much an + + align:start position:0% +companies and there's not so much an + + + align:start position:0% +companies and there's not so much an +innovation drive like there is here that + + align:start position:0% +innovation drive like there is here that + + + align:start position:0% +innovation drive like there is here that +like startup culture it's really + + align:start position:0% +like startup culture it's really + + + align:start position:0% +like startup culture it's really +attractive to a lot of the young + + align:start position:0% +attractive to a lot of the young + + + align:start position:0% +attractive to a lot of the young +Millennials I don't think that exists so + + align:start position:0% +Millennials I don't think that exists so + + + align:start position:0% +Millennials I don't think that exists so +much let's say in Korea so whether it be + + align:start position:0% +much let's say in Korea so whether it be + + + align:start position:0% +much let's say in Korea so whether it be +a job to like go to an SME or go to a + + align:start position:0% +a job to like go to an SME or go to a + + + align:start position:0% +a job to like go to an SME or go to a +big corporation I feel like that + + align:start position:0% +big corporation I feel like that + + + align:start position:0% +big corporation I feel like that +wouldn't even be a decision that would + + align:start position:0% +wouldn't even be a decision that would + + + align:start position:0% +wouldn't even be a decision that would +be like it'd be obvious to go to a big + + align:start position:0% +be like it'd be obvious to go to a big + + + align:start position:0% +be like it'd be obvious to go to a big +corporation so I don't know if kind of a + + align:start position:0% +corporation so I don't know if kind of a + + + align:start position:0% +corporation so I don't know if kind of a +cultural stigmas and the standards kind + + align:start position:0% +cultural stigmas and the standards kind + + + align:start position:0% +cultural stigmas and the standards kind +of a guided right so another attack + + align:start position:0% +of a guided right so another attack + + + align:start position:0% +of a guided right so another attack +another cultural point here we're + + align:start position:0% +another cultural point here we're + + + align:start position:0% +another cultural point here we're +dealing with about risk-taking really + + align:start position:0% +dealing with about risk-taking really + + + align:start position:0% +dealing with about risk-taking really +which is a pretty key element of us is + + align:start position:0% +which is a pretty key element of us is + + + align:start position:0% +which is a pretty key element of us is +pretty high tolerance resilient + + align:start position:0% +pretty high tolerance resilient + + + align:start position:0% +pretty high tolerance resilient +all right well good summaries to get + + align:start position:0% +all right well good summaries to get + + + align:start position:0% +all right well good summaries to get +through this I'm gonna push one to our + + align:start position:0% +through this I'm gonna push one to our + + + align:start position:0% +through this I'm gonna push one to our +next let me just do one short to see + + align:start position:0% +next let me just do one short to see + + + align:start position:0% +next let me just do one short to see +know what recessions look like in the US + + align:start position:0% +know what recessions look like in the US + + + align:start position:0% +know what recessions look like in the US +right and what's been going on and + + align:start position:0% +right and what's been going on and + + + align:start position:0% +right and what's been going on and +repeated sequences of recession here's + + align:start position:0% +repeated sequences of recession here's + + + align:start position:0% +repeated sequences of recession here's +the 1981 recession hit on fries right + + align:start position:0% +the 1981 recession hit on fries right + + + align:start position:0% +the 1981 recession hit on fries right +and jobs come back relatively quickly + + align:start position:0% +and jobs come back relatively quickly + + + align:start position:0% +and jobs come back relatively quickly +then 1919 start stretching it out + + align:start position:0% +then 1919 start stretching it out + + + align:start position:0% +then 1919 start stretching it out +further right then in 2001 you know the + + align:start position:0% +further right then in 2001 you know the + + + align:start position:0% +further right then in 2001 you know the +jobs recovery it's really slow markedly + + align:start position:0% +jobs recovery it's really slow markedly + + + align:start position:0% +jobs recovery it's really slow markedly +slow right and then 2008 9 recession you + + align:start position:0% +slow right and then 2008 9 recession you + + + align:start position:0% +slow right and then 2008 9 recession you +know even further out on the level of + + align:start position:0% +know even further out on the level of + + + align:start position:0% +know even further out on the level of +jaw reductions and now painful reality + + align:start position:0% +jaw reductions and now painful reality + + + align:start position:0% +jaw reductions and now painful reality +is that you still never recovered from + + align:start position:0% +is that you still never recovered from + + + align:start position:0% +is that you still never recovered from +the 2001 recession by the time in 2007 8 + + align:start position:0% +the 2001 recession by the time in 2007 8 + + + align:start position:0% +the 2001 recession by the time in 2007 8 +9 decision is among us right so there + + align:start position:0% +9 decision is among us right so there + + + align:start position:0% +9 decision is among us right so there +may be an argument that something + + align:start position:0% +may be an argument that something + + + align:start position:0% +may be an argument that something +fundamental is going on structurally and + + align:start position:0% +fundamental is going on structurally and + + + align:start position:0% +fundamental is going on structurally and +again money right when you see a chart + + align:start position:0% +again money right when you see a chart + + + align:start position:0% +again money right when you see a chart +like that + + align:start position:0% +like that + + + align:start position:0% +like that +right in each successive recession it's + + align:start position:0% +right in each successive recession it's + + + align:start position:0% +right in each successive recession it's +less of a business cycle it's more + + align:start position:0% +less of a business cycle it's more + + + align:start position:0% +less of a business cycle it's more +structural right and it looks like there + + align:start position:0% +structural right and it looks like there + + + align:start position:0% +structural right and it looks like there +are deep structural causes in these + + align:start position:0% +are deep structural causes in these + + + align:start position:0% +are deep structural causes in these +manufacturing employment Alliance when + + align:start position:0% +manufacturing employment Alliance when + + + align:start position:0% +manufacturing employment Alliance when +you starts with a chart like this we'll + + align:start position:0% +you starts with a chart like this we'll + + + align:start position:0% +you starts with a chart like this we'll +talk more about it next week + + align:start position:0% +talk more about it next week + + + align:start position:0% +talk more about it next week +but here's declining median income for + + align:start position:0% +but here's declining median income for + + + align:start position:0% +but here's declining median income for +us which we'll talk more about next week + + align:start position:0% +us which we'll talk more about next week + + + align:start position:0% +us which we'll talk more about next week +too so you know particularly pay + + align:start position:0% +too so you know particularly pay + + + align:start position:0% +too so you know particularly pay +attention to men who work tend to + + align:start position:0% +attention to men who work tend to + + + align:start position:0% +attention to men who work tend to +historically have played a larger role + + align:start position:0% +historically have played a larger role + + + align:start position:0% +historically have played a larger role +in manufacturing this really nice right + + align:start position:0% +in manufacturing this really nice right + + + align:start position:0% +in manufacturing this really nice right +so this is changing median real earnings + + align:start position:0% +so this is changing median real earnings + + + align:start position:0% +so this is changing median real earnings +for men with him from 1990 to 2015 + + align:start position:0% +for men with him from 1990 to 2015 + + + align:start position:0% +for men with him from 1990 to 2015 +so you know the extended period 9215 no + + align:start position:0% +so you know the extended period 9215 no + + + align:start position:0% +so you know the extended period 9215 no +high school diploma then median income + + align:start position:0% +high school diploma then median income + + + align:start position:0% +high school diploma then median income +decline in that + + align:start position:0% +decline in that + + + align:start position:0% +decline in that +20 high school diploma Wars some college + + align:start position:0% +20 high school diploma Wars some college + + + align:start position:0% +20 high school diploma Wars some college +13 and then advanced degrees 21 point + + align:start position:0% +13 and then advanced degrees 21 point + + + align:start position:0% +13 and then advanced degrees 21 point +rise bachelor's degrees 16 point for us + + align:start position:0% +rise bachelor's degrees 16 point for us + + + align:start position:0% +rise bachelor's degrees 16 point for us +this is a society that's going like this + + align:start position:0% +this is a society that's going like this + + + align:start position:0% +this is a society that's going like this +right and that's what we're dealing with + + align:start position:0% +right and that's what we're dealing with + + + align:start position:0% +right and that's what we're dealing with +and arguably is related to this let me + + align:start position:0% +and arguably is related to this let me + + + align:start position:0% +and arguably is related to this let me +let me move to Suzanne burger you should + + align:start position:0% +let me move to Suzanne burger you should + + + align:start position:0% +let me move to Suzanne burger you should +get to know her she's around here has + + align:start position:0% +get to know her she's around here has + + + align:start position:0% +get to know her she's around here has +been a great teacher for me this is her + + align:start position:0% +been a great teacher for me this is her + + + align:start position:0% +been a great teacher for me this is her +2005 book called how we compete and four + + align:start position:0% +2005 book called how we compete and four + + + align:start position:0% +2005 book called how we compete and four +essential point is that there are + + align:start position:0% +essential point is that there are + + + align:start position:0% +essential point is that there are +different varieties of capitalism we've + + align:start position:0% +different varieties of capitalism we've + + + align:start position:0% +different varieties of capitalism we've +been talking a lot about that today and + + align:start position:0% +been talking a lot about that today and + + + align:start position:0% +been talking a lot about that today and +the different approaches emerged between + + align:start position:0% +the different approaches emerged between + + + align:start position:0% +the different approaches emerged between +the u.s. and Asian economies in advanced + + align:start position:0% +the u.s. and Asian economies in advanced + + + align:start position:0% +the u.s. and Asian economies in advanced +technology goods in this later part of + + align:start position:0% +technology goods in this later part of + + + align:start position:0% +technology goods in this later part of +the 1990s early early 2000s time true so + + align:start position:0% +the 1990s early early 2000s time true so + + + align:start position:0% +the 1990s early early 2000s time true so +what's going on here + + align:start position:0% +what's going on here + + + align:start position:0% +what's going on here +IT as a driver and codable spec's + + align:start position:0% +IT as a driver and codable spec's + + + align:start position:0% +IT as a driver and codable spec's +time to you know computer driven + + align:start position:0% +time to you know computer driven + + + align:start position:0% +time to you know computer driven +equipment is enabling a divorce between + + align:start position:0% +equipment is enabling a divorce between + + + align:start position:0% +equipment is enabling a divorce between +production and design right so in the + + align:start position:0% +production and design right so in the + + + align:start position:0% +production and design right so in the +old time period right in the prior time + + align:start position:0% +old time period right in the prior time + + + align:start position:0% +old time period right in the prior time +period suzanne argues that manufacturing + + align:start position:0% +period suzanne argues that manufacturing + + + align:start position:0% +period suzanne argues that manufacturing +company's production firms were a lot + + align:start position:0% +company's production firms were a lot + + + align:start position:0% +company's production firms were a lot +like model airplanes right and you all + + align:start position:0% +like model airplanes right and you all + + + align:start position:0% +like model airplanes right and you all +probably don't remember fear of plastic + + align:start position:0% +probably don't remember fear of plastic + + + align:start position:0% +probably don't remember fear of plastic +model airplanes I do + + align:start position:0% +model airplanes I do + + + align:start position:0% +model airplanes I do +but you get this you know batch of + + align:start position:0% +but you get this you know batch of + + + align:start position:0% +but you get this you know batch of +plastic parts and they never you'd have + + align:start position:0% +plastic parts and they never you'd have + + + align:start position:0% +plastic parts and they never you'd have +to work them and you get glue all over + + align:start position:0% +to work them and you get glue all over + + + align:start position:0% +to work them and you get glue all over +them and a glue it's spillover right and + + align:start position:0% +them and a glue it's spillover right and + + + align:start position:0% +them and a glue it's spillover right and +it would just be a mess and you try and + + align:start position:0% +it would just be a mess and you try and + + + align:start position:0% +it would just be a mess and you try and +clean up the hood with clean accident + + align:start position:0% +clean up the hood with clean accident + + + align:start position:0% +clean up the hood with clean accident +you know and that and we've never and + + align:start position:0% +you know and that and we've never and + + + align:start position:0% +you know and that and we've never and +you'd put rubber bands around it to try + + align:start position:0% +you'd put rubber bands around it to try + + + align:start position:0% +you'd put rubber bands around it to try +and get it lock in place a new + + align:start position:0% +and get it lock in place a new + + + align:start position:0% +and get it lock in place a new +breakdancing try to fix it was just + + align:start position:0% +breakdancing try to fix it was just + + + align:start position:0% +breakdancing try to fix it was just +that's what manufacturing used to be + + align:start position:0% +that's what manufacturing used to be + + + align:start position:0% +that's what manufacturing used to be +like she argues right and to manage that + + align:start position:0% +like she argues right and to manage that + + + align:start position:0% +like she argues right and to manage that +you needed a very integrated vertical + + align:start position:0% +you needed a very integrated vertical + + + align:start position:0% +you needed a very integrated vertical +system with all parts of that system + + align:start position:0% +system with all parts of that system + + + align:start position:0% +system with all parts of that system +tied and connected together to get + + align:start position:0% +tied and connected together to get + + + align:start position:0% +tied and connected together to get +around that difficulty of the corrosion + + align:start position:0% +around that difficulty of the corrosion + + + align:start position:0% +around that difficulty of the corrosion +process but with codable IT based specs + + align:start position:0% +process but with codable IT based specs + + + align:start position:0% +process but with codable IT based specs +and computer equipment he moved to an + + align:start position:0% +and computer equipment he moved to an + + + align:start position:0% +and computer equipment he moved to an +ear up like us right it's all computer + + align:start position:0% +ear up like us right it's all computer + + + align:start position:0% +ear up like us right it's all computer +driven you're gonna be producing Legos + + align:start position:0% +driven you're gonna be producing Legos + + + align:start position:0% +driven you're gonna be producing Legos +and they are always gonna snap perfectly + + align:start position:0% +and they are always gonna snap perfectly + + + align:start position:0% +and they are always gonna snap perfectly +in place right that's how the production + + align:start position:0% +in place right that's how the production + + + align:start position:0% +in place right that's how the production +system changed she argued in these two + + align:start position:0% +system changed she argued in these two + + + align:start position:0% +system changed she argued in these two +from these two different eras and the + + align:start position:0% +from these two different eras and the + + + align:start position:0% +from these two different eras and the +classic example is the iPod you know + + align:start position:0% +classic example is the iPod you know + + + align:start position:0% +classic example is the iPod you know +Apple was able to pick a mix of mp3 best + + align:start position:0% +Apple was able to pick a mix of mp3 best + + + align:start position:0% +Apple was able to pick a mix of mp3 best +technologies and they tied it to a new + + align:start position:0% +technologies and they tied it to a new + + + align:start position:0% +technologies and they tied it to a new +software access system for music and + + align:start position:0% +software access system for music and + + + align:start position:0% +software access system for music and +database once you all know now I was + + align:start position:0% +database once you all know now I was + + + align:start position:0% +database once you all know now I was +video as well they're doing some you + + align:start position:0% +video as well they're doing some you + + + align:start position:0% +video as well they're doing some you +know a classic Apple movie right the + + align:start position:0% +know a classic Apple movie right the + + + align:start position:0% +know a classic Apple movie right the +problem mp3 players before Apple was + + align:start position:0% +problem mp3 players before Apple was + + + align:start position:0% +problem mp3 players before Apple was +that you had to commit a crime in order + + align:start position:0% +that you had to commit a crime in order + + + align:start position:0% +that you had to commit a crime in order +to use the mp3 player he was stealing + + align:start position:0% +to use the mp3 player he was stealing + + + align:start position:0% +to use the mp3 player he was stealing +someone's music right and you know this + + align:start position:0% +someone's music right and you know this + + + align:start position:0% +someone's music right and you know this +is a criminal act right what kind of + + align:start position:0% +is a criminal act right what kind of + + + align:start position:0% +is a criminal act right what kind of +product forces you to commit a criminal + + align:start position:0% +product forces you to commit a criminal + + + align:start position:0% +product forces you to commit a criminal +act and it's not a great product + + align:start position:0% +act and it's not a great product + + + align:start position:0% +act and it's not a great product +all right so Apple invents an entirely + + align:start position:0% +all right so Apple invents an entirely + + + align:start position:0% +all right so Apple invents an entirely +different way of organizing the music + + align:start position:0% +different way of organizing the music + + + align:start position:0% +different way of organizing the music +industry but it ties it to existing mp3 + + align:start position:0% +industry but it ties it to existing mp3 + + + align:start position:0% +industry but it ties it to existing mp3 +player technology which it precedes to + + align:start position:0% +player technology which it precedes to + + + align:start position:0% +player technology which it precedes to +perfect and how does it how is it able + + align:start position:0% +perfect and how does it how is it able + + + align:start position:0% +perfect and how does it how is it able +to do this we do this remarkably short + + align:start position:0% +to do this we do this remarkably short + + + align:start position:0% +to do this we do this remarkably short +period - it's a matter of months right + + align:start position:0% +period - it's a matter of months right + + + align:start position:0% +period - it's a matter of months right +so it figures out what the optimal mp3 + + align:start position:0% +so it figures out what the optimal mp3 + + + align:start position:0% +so it figures out what the optimal mp3 +player of technologies are who is + + align:start position:0% +player of technologies are who is + + + align:start position:0% +player of technologies are who is +producing them right and go to them and + + align:start position:0% +producing them right and go to them and + + + align:start position:0% +producing them right and go to them and +enter into contracts with all over the + + align:start position:0% +enter into contracts with all over the + + + align:start position:0% +enter into contracts with all over the +world to clean China but elsewhere as + + align:start position:0% +world to clean China but elsewhere as + + + align:start position:0% +world to clean China but elsewhere as +well and it knows that they're gonna + + align:start position:0% +well and it knows that they're gonna + + + align:start position:0% +well and it knows that they're gonna +snap together like Legos in the end + + align:start position:0% +snap together like Legos in the end + + + align:start position:0% +snap together like Legos in the end +because they are using credible specs on + + align:start position:0% +because they are using credible specs on + + + align:start position:0% +because they are using credible specs on +computer driven equipment right so you + + align:start position:0% +computer driven equipment right so you + + + align:start position:0% +computer driven equipment right so you +can now distribute your production model + + align:start position:0% +can now distribute your production model + + + align:start position:0% +can now distribute your production model +so Apple doesn't have can do this in a + + align:start position:0% +so Apple doesn't have can do this in a + + + align:start position:0% +so Apple doesn't have can do this in a +matter of months it doesn't have to go + + align:start position:0% +matter of months it doesn't have to go + + + align:start position:0% +matter of months it doesn't have to go +by you know green space right you know + + align:start position:0% +by you know green space right you know + + + align:start position:0% +by you know green space right you know +outside Wilmington North Carolina or + + align:start position:0% +outside Wilmington North Carolina or + + + align:start position:0% +outside Wilmington North Carolina or +something and build a new factory and + + align:start position:0% +something and build a new factory and + + + align:start position:0% +something and build a new factory and +get all the permitting and spend years + + align:start position:0% +get all the permitting and spend years + + + align:start position:0% +get all the permitting and spend years +doing this and raise a billion dollars + + align:start position:0% +doing this and raise a billion dollars + + + align:start position:0% +doing this and raise a billion dollars +to do it right instead it quickly enters + + align:start position:0% +to do it right instead it quickly enters + + + align:start position:0% +to do it right instead it quickly enters +into a deal a series of deals with + + align:start position:0% +into a deal a series of deals with + + + align:start position:0% +into a deal a series of deals with +existing producers but as knows that it + + align:start position:0% +existing producers but as knows that it + + + align:start position:0% +existing producers but as knows that it +can bring the product back right because + + align:start position:0% +can bring the product back right because + + + align:start position:0% +can bring the product back right because +it's going to be Legos and they're gonna + + align:start position:0% +it's going to be Legos and they're gonna + + + align:start position:0% +it's going to be Legos and they're gonna +snap into place right please all right + + align:start position:0% +snap into place right please all right + + + align:start position:0% +snap into place right please all right +absolutely and you know I was in Japan + + align:start position:0% +absolutely and you know I was in Japan + + + align:start position:0% +absolutely and you know I was in Japan +in 2006 and in January it's been a + + align:start position:0% +in 2006 and in January it's been a + + + align:start position:0% +in 2006 and in January it's been a +wonderful day as it was snowing in Kyoto + + align:start position:0% +wonderful day as it was snowing in Kyoto + + + align:start position:0% +wonderful day as it was snowing in Kyoto +which was completely it was mostly back + + align:start position:0% +which was completely it was mostly back + + + align:start position:0% +which was completely it was mostly back +in Tokyo and the headline in the leading + + align:start position:0% +in Tokyo and the headline in the leading + + + align:start position:0% +in Tokyo and the headline in the leading +english-language newspaper in Tokyo was + + align:start position:0% +english-language newspaper in Tokyo was + + + align:start position:0% +english-language newspaper in Tokyo was +Apple sells 14 million iPods in two + + align:start position:0% +Apple sells 14 million iPods in two + + + align:start position:0% +Apple sells 14 million iPods in two +weeks semicolon where is Sony + + align:start position:0% +weeks semicolon where is Sony + + + align:start position:0% +weeks semicolon where is Sony +exclamation point exclamation it was + + align:start position:0% +exclamation point exclamation it was + + + align:start position:0% +exclamation point exclamation it was +just you know a reality that Apple + + align:start position:0% +just you know a reality that Apple + + + align:start position:0% +just you know a reality that Apple +available to kind of spring to this + + align:start position:0% +available to kind of spring to this + + + align:start position:0% +available to kind of spring to this +whole new product plan + + align:start position:0% +whole new product plan + + + align:start position:0% +whole new product plan +remarkably short period of time by using + + align:start position:0% +remarkably short period of time by using + + + align:start position:0% +remarkably short period of time by using +a digital dispersed distributed + + align:start position:0% +a digital dispersed distributed + + + align:start position:0% +a digital dispersed distributed +production law and it's it's pretty + + align:start position:0% +production law and it's it's pretty + + + align:start position:0% +production law and it's it's pretty +irresistible because you get that level + + align:start position:0% +irresistible because you get that level + + + align:start position:0% +irresistible because you get that level +of time and investments you have to + + align:start position:0% +of time and investments you have to + + + align:start position:0% +of time and investments you have to +assemble ahead of time makes this really + + align:start position:0% +assemble ahead of time makes this really + + + align:start position:0% +assemble ahead of time makes this really +quite convenient so lots of US firms + + align:start position:0% +quite convenient so lots of US firms + + + align:start position:0% +quite convenient so lots of US firms +move to this model and they're in + + align:start position:0% +move to this model and they're in + + + align:start position:0% +move to this model and they're in +technologically enabled by these + + align:start position:0% +technologically enabled by these + + + align:start position:0% +technologically enabled by these +technological advances to do so now + + align:start position:0% +technological advances to do so now + + + align:start position:0% +technological advances to do so now +Suzanne also goes on to argue pay other + + align:start position:0% +Suzanne also goes on to argue pay other + + + align:start position:0% +Suzanne also goes on to argue pay other +people and she's looking at group of + + align:start position:0% +people and she's looking at group of + + + align:start position:0% +people and she's looking at group of +Asian countries and friends are not + + align:start position:0% +Asian countries and friends are not + + + align:start position:0% +Asian countries and friends are not +necessarily doing this right so in Korea + + align:start position:0% +necessarily doing this right so in Korea + + + align:start position:0% +necessarily doing this right so in Korea +samsung continues to control the key + + align:start position:0% +samsung continues to control the key + + + align:start position:0% +samsung continues to control the key +components it allows a certain amount of + + align:start position:0% +components it allows a certain amount of + + + align:start position:0% +components it allows a certain amount of +assembly offshore in Japan there is a + + align:start position:0% +assembly offshore in Japan there is a + + + align:start position:0% +assembly offshore in Japan there is a +conscious effort to keep integrated in + + align:start position:0% +conscious effort to keep integrated in + + + align:start position:0% +conscious effort to keep integrated in +an integrated innovation model and + + align:start position:0% +an integrated innovation model and + + + align:start position:0% +an integrated innovation model and +control all the critical stages so the + + align:start position:0% +control all the critical stages so the + + + align:start position:0% +control all the critical stages so the +risk in the Apple model is that your + + align:start position:0% +risk in the Apple model is that your + + + align:start position:0% +risk in the Apple model is that your +offshoring your production capability + + align:start position:0% +offshoring your production capability + + + align:start position:0% +offshoring your production capability +and a certain amount of the innovation + + align:start position:0% +and a certain amount of the innovation + + + align:start position:0% +and a certain amount of the innovation +capability is going to follow right + + align:start position:0% +capability is going to follow right + + + align:start position:0% +capability is going to follow right +that's the risk and to avoid that + + align:start position:0% +that's the risk and to avoid that + + + align:start position:0% +that's the risk and to avoid that +companies in Japan and Korea are moving + + align:start position:0% +companies in Japan and Korea are moving + + + align:start position:0% +companies in Japan and Korea are moving +in a very different kind of + + align:start position:0% +in a very different kind of + + + align:start position:0% +in a very different kind of +organizational model both models she + + align:start position:0% +organizational model both models she + + + align:start position:0% +organizational model both models she +argue argues may well work right so + + align:start position:0% +argue argues may well work right so + + + align:start position:0% +argue argues may well work right so +these are a varieties of capitalism at + + align:start position:0% +these are a varieties of capitalism at + + + align:start position:0% +these are a varieties of capitalism at +play here the important thing one should + + align:start position:0% +play here the important thing one should + + + align:start position:0% +play here the important thing one should +understand is that keeping now for the + + align:start position:0% +understand is that keeping now for the + + + align:start position:0% +understand is that keeping now for the +first time really historically several + + align:start position:0% +first time really historically several + + + align:start position:0% +first time really historically several +productions in design and it's pretty + + align:start position:0% +productions in design and it's pretty + + + align:start position:0% +productions in design and it's pretty +irresistible to do so because you + + align:start position:0% +irresistible to do so because you + + + align:start position:0% +irresistible to do so because you +significantly reduce your risk and + + align:start position:0% +significantly reduce your risk and + + + align:start position:0% +significantly reduce your risk and +exposure and your investment levels + + align:start position:0% +exposure and your investment levels + + + align:start position:0% +exposure and your investment levels +upfront so that's why she would argue US + + align:start position:0% +upfront so that's why she would argue US + + + align:start position:0% +upfront so that's why she would argue US +firms tend to pursue this problem and + + align:start position:0% +firms tend to pursue this problem and + + + align:start position:0% +firms tend to pursue this problem and +won't go to her next book next week and + + align:start position:0% +won't go to her next book next week and + + + align:start position:0% +won't go to her next book next week and +discover why the model may not + + align:start position:0% +discover why the model may not + + + align:start position:0% +discover why the model may not +necessarily be optimal till next week so + + align:start position:0% +necessarily be optimal till next week so + + + align:start position:0% +necessarily be optimal till next week so +who's got who's got Suzanne + + align:start position:0% +who's got who's got Suzanne + + + align:start position:0% +who's got who's got Suzanne +let's go ahead so in how we can keep + + align:start position:0% +let's go ahead so in how we can keep + + + align:start position:0% +let's go ahead so in how we can keep +basically they look at a whole bunch of + + align:start position:0% +basically they look at a whole bunch of + + + align:start position:0% +basically they look at a whole bunch of +different companies and many different + + align:start position:0% +different companies and many different + + + align:start position:0% +different companies and many different +industries and try to find what it is + + align:start position:0% +industries and try to find what it is + + + align:start position:0% +industries and try to find what it is +that + + align:start position:0% +that + + + align:start position:0% +that +he's competitive so they find that + + align:start position:0% +he's competitive so they find that + + + align:start position:0% +he's competitive so they find that +there's no single paradigm and I wanted + + align:start position:0% +there's no single paradigm and I wanted + + + align:start position:0% +there's no single paradigm and I wanted +the key lines there's that there's + + align:start position:0% +the key lines there's that there's + + + align:start position:0% +the key lines there's that there's +there's no sunset industries just sunset + + align:start position:0% +there's no sunset industries just sunset + + + align:start position:0% +there's no sunset industries just sunset +strategies so we need to be competitive + + align:start position:0% +strategies so we need to be competitive + + + align:start position:0% +strategies so we need to be competitive +with the house that companies kind of + + align:start position:0% +with the house that companies kind of + + + align:start position:0% +with the house that companies kind of +always need to be questioning that + + align:start position:0% +always need to be questioning that + + + align:start position:0% +always need to be questioning that +process he's looking for ways to + + align:start position:0% +process he's looking for ways to + + + align:start position:0% +process he's looking for ways to +innovate and then you know I got out of + + align:start position:0% +innovate and then you know I got out of + + + align:start position:0% +innovate and then you know I got out of +it were primarily two different balances + + align:start position:0% +it were primarily two different balances + + + align:start position:0% +it were primarily two different balances +one is this idea of intelligent + + align:start position:0% +one is this idea of intelligent + + + align:start position:0% +one is this idea of intelligent +offshoring where you know maybe option + + align:start position:0% +offshoring where you know maybe option + + + align:start position:0% +offshoring where you know maybe option +outsourcing all you're all here + + align:start position:0% +outsourcing all you're all here + + + align:start position:0% +outsourcing all you're all here +manufacturing is not the best idea + + align:start position:0% +manufacturing is not the best idea + + + align:start position:0% +manufacturing is not the best idea +because there's there are other costs + + align:start position:0% +because there's there are other costs + + + align:start position:0% +because there's there are other costs +involved with that and can create + + align:start position:0% +involved with that and can create + + + align:start position:0% +involved with that and can create +innovation gaps within within your own + + align:start position:0% +innovation gaps within within your own + + + align:start position:0% +innovation gaps within within your own +country and then the other balance being + + align:start position:0% +country and then the other balance being + + + align:start position:0% +country and then the other balance being +with IP and how do you create a a + + align:start position:0% +with IP and how do you create a a + + + align:start position:0% +with IP and how do you create a a +collaborative environment where that's + + align:start position:0% +collaborative environment where that's + + + align:start position:0% +collaborative environment where that's +conducive to growth and development but + + align:start position:0% +conducive to growth and development but + + + align:start position:0% +conducive to growth and development but +also kind of protecting your IP so that + + align:start position:0% +also kind of protecting your IP so that + + + align:start position:0% +also kind of protecting your IP so that +you don't create your own competitor and + + align:start position:0% +you don't create your own competitor and + + + align:start position:0% +you don't create your own competitor and +so I have some questions I think one of + + align:start position:0% +so I have some questions I think one of + + + align:start position:0% +so I have some questions I think one of +the first things is you know how do you + + align:start position:0% +the first things is you know how do you + + + align:start position:0% +the first things is you know how do you +companies in your sleep competitive + + align:start position:0% +companies in your sleep competitive + + + align:start position:0% +companies in your sleep competitive +sectors actually set themselves up so + + align:start position:0% +sectors actually set themselves up so + + + align:start position:0% +sectors actually set themselves up so +you constantly be innovating it's the + + align:start position:0% +you constantly be innovating it's the + + + align:start position:0% +you constantly be innovating it's the +tough thing to do yeah let me go to + + align:start position:0% +tough thing to do yeah let me go to + + + align:start position:0% +tough thing to do yeah let me go to +square the importance we push the number + + align:start position:0% +square the importance we push the number + + + align:start position:0% +square the importance we push the number +of companies that are 100 years old and + + align:start position:0% +of companies that are 100 years old and + + + align:start position:0% +of companies that are 100 years old and +they go through disruption that may + + align:start position:0% +they go through disruption that may + + + align:start position:0% +they go through disruption that may +change and they die and it's long + + align:start position:0% +change and they die and it's long + + + align:start position:0% +change and they die and it's long +lasting monitoring companies are rare + + align:start position:0% +lasting monitoring companies are rare + + + align:start position:0% +lasting monitoring companies are rare +and it's retaining this innovation + + align:start position:0% +and it's retaining this innovation + + + align:start position:0% +and it's retaining this innovation +capability that's so great so you're + + align:start position:0% +capability that's so great so you're + + + align:start position:0% +capability that's so great so you're +driving our really key questions + + align:start position:0% + + + + align:start position:0% + +because when you mention like innovative + + align:start position:0% +because when you mention like innovative + + + align:start position:0% +because when you mention like innovative +firms it burns a keep staying at the + + align:start position:0% +firms it burns a keep staying at the + + + align:start position:0% +firms it burns a keep staying at the +head I think my first thought is Apple + + align:start position:0% +head I think my first thought is Apple + + + align:start position:0% +head I think my first thought is Apple +and I think Apple so I like 30 years old + + align:start position:0% +and I think Apple so I like 30 years old + + + align:start position:0% +and I think Apple so I like 30 years old +now so it's like now give it and it + + align:start position:0% +now so it's like now give it and it + + + align:start position:0% +now so it's like now give it and it +hasn't even proven that it can would + + align:start position:0% +hasn't even proven that it can would + + + align:start position:0% +hasn't even proven that it can would +stay like the trend but so I'm trying to + + align:start position:0% +stay like the trend but so I'm trying to + + + align:start position:0% +stay like the trend but so I'm trying to +think of something that is actually like + + align:start position:0% +think of something that is actually like + + + align:start position:0% +think of something that is actually like +more than 50 years old as inconsistently + + align:start position:0% +more than 50 years old as inconsistently + + + align:start position:0% +more than 50 years old as inconsistently +I got talking things I think coke is + + align:start position:0% +I got talking things I think coke is + + + align:start position:0% +I got talking things I think coke is +probably my favorite example yeah I + + align:start position:0% +probably my favorite example yeah I + + + align:start position:0% +probably my favorite example yeah I +think IBM I know more about just as they + + align:start position:0% +think IBM I know more about just as they + + + align:start position:0% +think IBM I know more about just as they +develop sort of in the wave in the + + align:start position:0% +develop sort of in the wave in the + + + align:start position:0% +develop sort of in the wave in the +context of like the u.s. is looking for + + align:start position:0% +context of like the u.s. is looking for + + + align:start position:0% +context of like the u.s. is looking for +sort of answers in the semiconductor + + align:start position:0% +sort of answers in the semiconductor + + + align:start position:0% +sort of answers in the semiconductor +round but more importantly like they had + + align:start position:0% +round but more importantly like they had + + + align:start position:0% +round but more importantly like they had +to deal with the whole advent of + + align:start position:0% +to deal with the whole advent of + + + align:start position:0% +to deal with the whole advent of +personal computing and then they shifted + + align:start position:0% +personal computing and then they shifted + + + align:start position:0% +personal computing and then they shifted +now it's more like IT based services and + + align:start position:0% +now it's more like IT based services and + + + align:start position:0% +now it's more like IT based services and +so they just contract out and I solve + + align:start position:0% +so they just contract out and I solve + + + align:start position:0% +so they just contract out and I solve +your problems and I think it's like you + + align:start position:0% +your problems and I think it's like you + + + align:start position:0% +your problems and I think it's like you +have to be sensitive just sort of these + + align:start position:0% +have to be sensitive just sort of these + + + align:start position:0% +have to be sensitive just sort of these +big technological disruptions and then + + align:start position:0% +big technological disruptions and then + + + align:start position:0% +big technological disruptions and then +sort of ride the wave or like get out + + align:start position:0% +sort of ride the wave or like get out + + + align:start position:0% +sort of ride the wave or like get out +completely and sort of like being able + + align:start position:0% +completely and sort of like being able + + + align:start position:0% +completely and sort of like being able +to shut down kind of large sections of + + align:start position:0% +to shut down kind of large sections of + + + align:start position:0% +to shut down kind of large sections of +your like it was previously haven't ages + + align:start position:0% +your like it was previously haven't ages + + + align:start position:0% +your like it was previously haven't ages +maybe for coda to use disposable cameras + + align:start position:0% +maybe for coda to use disposable cameras + + + align:start position:0% +maybe for coda to use disposable cameras +but now we have digital cameras and so + + align:start position:0% +but now we have digital cameras and so + + + align:start position:0% +but now we have digital cameras and so +yeah it would be like okay we're gonna + + align:start position:0% +yeah it would be like okay we're gonna + + + align:start position:0% +yeah it would be like okay we're gonna +really radically change the course of + + align:start position:0% +really radically change the course of + + + align:start position:0% +really radically change the course of +our company in order to like sustain and + + align:start position:0% +our company in order to like sustain and + + + align:start position:0% +our company in order to like sustain and +stay alive and that's kind of our + + align:start position:0% +stay alive and that's kind of our + + + align:start position:0% +stay alive and that's kind of our +decision to have to be able to think and + + align:start position:0% +decision to have to be able to think and + + + align:start position:0% +decision to have to be able to think and +so I think the resistance to change + + align:start position:0% +so I think the resistance to change + + + align:start position:0% +so I think the resistance to change +piece + + align:start position:0% +piece + + + align:start position:0% +piece +it's probably the differentiates your + + align:start position:0% +it's probably the differentiates your + + + align:start position:0% +it's probably the differentiates your +cokes from survey maybe you're less all + + align:start position:0% +cokes from survey maybe you're less all + + + align:start position:0% +cokes from survey maybe you're less all +messing companies and next week you're + + align:start position:0% +messing companies and next week you're + + + align:start position:0% +messing companies and next week you're +gonna start to read our textbook which + + align:start position:0% +gonna start to read our textbook which + + + align:start position:0% +gonna start to read our textbook which +is about the difficulty of innovation in + + align:start position:0% +is about the difficulty of innovation in + + + align:start position:0% +is about the difficulty of innovation in +complex established legacy economics + + align:start position:0% + + + + align:start position:0% + +in answering your question I mean the + + align:start position:0% +in answering your question I mean the + + + align:start position:0% +in answering your question I mean the +question - is just like if there's these + + align:start position:0% +question - is just like if there's these + + + align:start position:0% +question - is just like if there's these +new capabilities and you don't use them + + align:start position:0% +new capabilities and you don't use them + + + align:start position:0% +new capabilities and you don't use them +somebody will so it's kind of like a + + align:start position:0% +somebody will so it's kind of like a + + + align:start position:0% +somebody will so it's kind of like a +Pandora's box because like I might not + + align:start position:0% +Pandora's box because like I might not + + + align:start position:0% +Pandora's box because like I might not +want to change my whole supply chain and + + align:start position:0% +want to change my whole supply chain and + + + align:start position:0% +want to change my whole supply chain and +like I was called get rid of a jobs for + + align:start position:0% +like I was called get rid of a jobs for + + + align:start position:0% +like I was called get rid of a jobs for +my employees because of the all things + + align:start position:0% +my employees because of the all things + + + align:start position:0% +my employees because of the all things +that will happen after but my + + align:start position:0% +that will happen after but my + + + align:start position:0% +that will happen after but my +competitors probably gonna do it and if + + align:start position:0% +competitors probably gonna do it and if + + + align:start position:0% +competitors probably gonna do it and if +I don't do it then he's gonna have lower + + align:start position:0% +I don't do it then he's gonna have lower + + + align:start position:0% +I don't do it then he's gonna have lower +prop like he's gonna lower this cost and + + align:start position:0% +prop like he's gonna lower this cost and + + + align:start position:0% +prop like he's gonna lower this cost and +he'll the most likely big me to market + + align:start position:0% +he'll the most likely big me to market + + + align:start position:0% +he'll the most likely big me to market +and there's a quote from Carnac from + + align:start position:0% +and there's a quote from Carnac from + + + align:start position:0% +and there's a quote from Carnac from +Andrew Carnegie where he goes like you + + align:start position:0% +Andrew Carnegie where he goes like you + + + align:start position:0% +Andrew Carnegie where he goes like you +should always use the best tools even if + + align:start position:0% +should always use the best tools even if + + + align:start position:0% +should always use the best tools even if +it's very hard to cheat your old tools + + align:start position:0% +it's very hard to cheat your old tools + + + align:start position:0% +it's very hard to cheat your old tools +because like as a Titan of industry if + + align:start position:0% +because like as a Titan of industry if + + + align:start position:0% +because like as a Titan of industry if +you don't somebody else + + align:start position:0% + + + + align:start position:0% + +the other thing I'd like to say so if + + align:start position:0% +the other thing I'd like to say so if + + + align:start position:0% +the other thing I'd like to say so if +you've got I know it goes a little bit + + align:start position:0% +you've got I know it goes a little bit + + + align:start position:0% +you've got I know it goes a little bit +into into next week's everything to get + + align:start position:0% +into into next week's everything to get + + + align:start position:0% +into into next week's everything to get +but I to what extent do you think that + + align:start position:0% +but I to what extent do you think that + + + align:start position:0% +but I to what extent do you think that +the design of manufacturing can actually + + align:start position:0% +the design of manufacturing can actually + + + align:start position:0% +the design of manufacturing can actually +be be separated I know yeah I might see + + align:start position:0% +be be separated I know yeah I might see + + + align:start position:0% +be be separated I know yeah I might see +like in the kind of engineering + + align:start position:0% +like in the kind of engineering + + + align:start position:0% +like in the kind of engineering +department you know there's so big + + align:start position:0% +department you know there's so big + + + align:start position:0% +department you know there's so big +emphasis on taking the manufacturing + + align:start position:0% +emphasis on taking the manufacturing + + + align:start position:0% +emphasis on taking the manufacturing +classes in terms of just understanding + + align:start position:0% +classes in terms of just understanding + + + align:start position:0% +classes in terms of just understanding +like when you're designing what is it + + align:start position:0% +like when you're designing what is it + + + align:start position:0% +like when you're designing what is it +feasible it is what is possible at the + + align:start position:0% +feasible it is what is possible at the + + + align:start position:0% +feasible it is what is possible at the +manufactures it may be with 3d printing + + align:start position:0% +manufactures it may be with 3d printing + + + align:start position:0% +manufactures it may be with 3d printing +like it's a little bit more separate + + align:start position:0% +like it's a little bit more separate + + + align:start position:0% +like it's a little bit more separate +you've basically said anything can be + + align:start position:0% +you've basically said anything can be + + + align:start position:0% +you've basically said anything can be +made but uh but there's just a lot of + + align:start position:0% +made but uh but there's just a lot of + + + align:start position:0% +made but uh but there's just a lot of +know-how kind of embodied in and having + + align:start position:0% +know-how kind of embodied in and having + + + align:start position:0% +know-how kind of embodied in and having +the manufacturing there to it I know I + + align:start position:0% +the manufacturing there to it I know I + + + align:start position:0% +the manufacturing there to it I know I +don't fully think that it can be like or + + align:start position:0% +don't fully think that it can be like or + + + align:start position:0% +don't fully think that it can be like or +it's wise to fully separate them I want + + align:start position:0% +it's wise to fully separate them I want + + + align:start position:0% +it's wise to fully separate them I want +to see if people also have some thoughts + + align:start position:0% +to see if people also have some thoughts + + + align:start position:0% +to see if people also have some thoughts +day I I was gonna say that maybe the + + align:start position:0% +day I I was gonna say that maybe the + + + align:start position:0% +day I I was gonna say that maybe the +separation is just a figment of our + + align:start position:0% +separation is just a figment of our + + + align:start position:0% +separation is just a figment of our +imaginations because I know that when + + align:start position:0% +imaginations because I know that when + + + align:start position:0% +imaginations because I know that when +Suzanne Berger was on the panel and the + + align:start position:0% +Suzanne Berger was on the panel and the + + + align:start position:0% +Suzanne Berger was on the panel and the +boot camp course I think it was Suzanne + + align:start position:0% +boot camp course I think it was Suzanne + + + align:start position:0% +boot camp course I think it was Suzanne +who said that the people who the + + align:start position:0% +who said that the people who the + + + align:start position:0% +who said that the people who the +designers for Apple spend most of their + + align:start position:0% +designers for Apple spend most of their + + + align:start position:0% +designers for Apple spend most of their +time not who's been their time in the + + align:start position:0% +time not who's been their time in the + + + align:start position:0% +time not who's been their time in the +menu back to the offshore manufacturing + + align:start position:0% +menu back to the offshore manufacturing + + + align:start position:0% +menu back to the offshore manufacturing +ship + + align:start position:0% +ship + + + align:start position:0% +ship +so they're not really separate although + + align:start position:0% +so they're not really separate although + + + align:start position:0% +so they're not really separate although +their quote-unquote separate yeah I + + align:start position:0% +their quote-unquote separate yeah I + + + align:start position:0% +their quote-unquote separate yeah I +think also objective is kind of + + align:start position:0% +think also objective is kind of + + + align:start position:0% +think also objective is kind of +important in like if you're trying to + + align:start position:0% +important in like if you're trying to + + + align:start position:0% +important in like if you're trying to +separate like what are you trying to + + align:start position:0% +separate like what are you trying to + + + align:start position:0% +separate like what are you trying to +separate in order to do if you're trying + + align:start position:0% +separate in order to do if you're trying + + + align:start position:0% +separate in order to do if you're trying +to separate or cut costs yeah like + + align:start position:0% +to separate or cut costs yeah like + + + align:start position:0% +to separate or cut costs yeah like +you'll find a way because it'll be more + + align:start position:0% +you'll find a way because it'll be more + + + align:start position:0% +you'll find a way because it'll be more +advantageous for you to kind of send + + align:start position:0% +advantageous for you to kind of send + + + align:start position:0% +advantageous for you to kind of send +your manufacturing section over it here + + align:start position:0% +your manufacturing section over it here + + + align:start position:0% +your manufacturing section over it here +Apple but like even if you do that + + align:start position:0% +Apple but like even if you do that + + + align:start position:0% +Apple but like even if you do that +you're gonna have to send your designers + + align:start position:0% +you're gonna have to send your designers + + + align:start position:0% +you're gonna have to send your designers +in order to do the next day and really + + align:start position:0% +in order to do the next day and really + + + align:start position:0% +in order to do the next day and really +consider how am I going to manufacture + + align:start position:0% +consider how am I going to manufacture + + + align:start position:0% +consider how am I going to manufacture +this thing that I've designed and I + + align:start position:0% +this thing that I've designed and I + + + align:start position:0% +this thing that I've designed and I +could never do that like you can't + + align:start position:0% +could never do that like you can't + + + align:start position:0% +could never do that like you can't +separate them so the mechanical + + align:start position:0% +separate them so the mechanical + + + align:start position:0% +separate them so the mechanical +engineering department I think it's + + align:start position:0% +engineering department I think it's + + + align:start position:0% +engineering department I think it's +probably pretty smart by like training + + align:start position:0% +probably pretty smart by like training + + + align:start position:0% +probably pretty smart by like training +when trading all the mechanical + + align:start position:0% +when trading all the mechanical + + + align:start position:0% +when trading all the mechanical +engineers we're then going to go out + + align:start position:0% +engineers we're then going to go out + + + align:start position:0% +engineers we're then going to go out +design and manufacture steel you might + + align:start position:0% +design and manufacture steel you might + + + align:start position:0% +design and manufacture steel you might +specialize and one of the other like you + + align:start position:0% +specialize and one of the other like you + + + align:start position:0% +specialize and one of the other like you +need to have a strong basis and a + + align:start position:0% +need to have a strong basis and a + + + align:start position:0% +need to have a strong basis and a +foundation of both and understand that + + align:start position:0% +foundation of both and understand that + + + align:start position:0% +foundation of both and understand that +both are critical in order to like do + + align:start position:0% +both are critical in order to like do + + + align:start position:0% +both are critical in order to like do +anything that's probably long last year + + align:start position:0% +anything that's probably long last year + + + align:start position:0% +anything that's probably long last year +meaningful + + align:start position:0% +meaningful + + + align:start position:0% +meaningful +I guess quote innovative let me talk + + align:start position:0% +I guess quote innovative let me talk + + + align:start position:0% +I guess quote innovative let me talk +about the design what do we do mean the + + align:start position:0% +about the design what do we do mean the + + + align:start position:0% +about the design what do we do mean the +designer of an industrial system do we + + align:start position:0% +designer of an industrial system do we + + + align:start position:0% +designer of an industrial system do we +mean the designer of an industrial + + align:start position:0% +mean the designer of an industrial + + + align:start position:0% +mean the designer of an industrial +appliance do mean the designer of + + align:start position:0% +appliance do mean the designer of + + + align:start position:0% +appliance do mean the designer of +hardware do me the designer of software + + align:start position:0% +hardware do me the designer of software + + + align:start position:0% +hardware do me the designer of software +what components and design are we + + align:start position:0% +what components and design are we + + + align:start position:0% +what components and design are we +concerned about and in what ways is this + + align:start position:0% +concerned about and in what ways is this + + + align:start position:0% +concerned about and in what ways is this +sort of relevant and the conversation + + align:start position:0% +sort of relevant and the conversation + + + align:start position:0% +sort of relevant and the conversation +we're having right now about integration + + align:start position:0% +we're having right now about integration + + + align:start position:0% +we're having right now about integration +processes + + align:start position:0% +processes + + + align:start position:0% +processes +oh I was viewing it when we see like + + align:start position:0% +oh I was viewing it when we see like + + + align:start position:0% +oh I was viewing it when we see like +we're comparing the design of + + align:start position:0% +we're comparing the design of + + + align:start position:0% +we're comparing the design of +manufacturing so I wouldn't think of it + + align:start position:0% +manufacturing so I wouldn't think of it + + + align:start position:0% +manufacturing so I wouldn't think of it +so much as like software and primarily + + align:start position:0% +so much as like software and primarily + + + align:start position:0% +so much as like software and primarily +Hardware where the design may be you + + align:start position:0% +Hardware where the design may be you + + + align:start position:0% +Hardware where the design may be you +know having a dream on or a you know way + + align:start position:0% +know having a dream on or a you know way + + + align:start position:0% +know having a dream on or a you know way +out of my my circuit board you know that + + align:start position:0% +out of my my circuit board you know that + + + align:start position:0% +out of my my circuit board you know that +I'm going to send to a manufacturer and + + align:start position:0% +I'm going to send to a manufacturer and + + + align:start position:0% +I'm going to send to a manufacturer and +the other side of the world who will you + + align:start position:0% +the other side of the world who will you + + + align:start position:0% +the other side of the world who will you +know actually make those components + + align:start position:0% +know actually make those components + + + align:start position:0% +know actually make those components +together that's what I guess a reason + + align:start position:0% +together that's what I guess a reason + + + align:start position:0% +together that's what I guess a reason +are concerned because it delight myself + + align:start position:0% +are concerned because it delight myself + + + align:start position:0% +are concerned because it delight myself +I think of myself as a design researcher + + align:start position:0% +I think of myself as a design researcher + + + align:start position:0% +I think of myself as a design researcher +right because I think about the ways in + + align:start position:0% +right because I think about the ways in + + + align:start position:0% +right because I think about the ways in +which you can take systems engineering + + align:start position:0% +which you can take systems engineering + + + align:start position:0% +which you can take systems engineering +approaches to social issues and there's + + align:start position:0% +approaches to social issues and there's + + + align:start position:0% +approaches to social issues and there's +a big debate right now in the design + + align:start position:0% +a big debate right now in the design + + + align:start position:0% +a big debate right now in the design +community about who gets to create it + + align:start position:0% +community about who gets to create it + + + align:start position:0% +community about who gets to create it +and there's even more of a debate about + + align:start position:0% +and there's even more of a debate about + + + align:start position:0% +and there's even more of a debate about +the sort of nuances and in exerting the + + align:start position:0% +the sort of nuances and in exerting the + + + align:start position:0% +the sort of nuances and in exerting the +power in creating something right like + + align:start position:0% +power in creating something right like + + + align:start position:0% +power in creating something right like +all of these partner choices are + + align:start position:0% +all of these partner choices are + + + align:start position:0% +all of these partner choices are +political choices and they have impacts + + align:start position:0% +political choices and they have impacts + + + align:start position:0% +political choices and they have impacts +on both the user and the society in + + align:start position:0% +on both the user and the society in + + + align:start position:0% +on both the user and the society in +which they're implemented so that's why + + align:start position:0% +which they're implemented so that's why + + + align:start position:0% +which they're implemented so that's why +I think it's important to really + + align:start position:0% +I think it's important to really + + + align:start position:0% +I think it's important to really +consider when both the author and we + + align:start position:0% +consider when both the author and we + + + align:start position:0% +consider when both the author and we +talk about design what kind of design + + align:start position:0% +talk about design what kind of design + + + align:start position:0% +talk about design what kind of design +were talking about and we view it not + + align:start position:0% +were talking about and we view it not + + + align:start position:0% +were talking about and we view it not +necessarily as a neutral and apolitical + + align:start position:0% +necessarily as a neutral and apolitical + + + align:start position:0% +necessarily as a neutral and apolitical +actually but very much as a reflection + + align:start position:0% +actually but very much as a reflection + + + align:start position:0% +actually but very much as a reflection +of what that's corporation values and + + align:start position:0% +of what that's corporation values and + + + align:start position:0% +of what that's corporation values and +what kind of the values they want to + + align:start position:0% +what kind of the values they want to + + + align:start position:0% +what kind of the values they want to +promote in a society so this you know + + align:start position:0% +promote in a society so this you know + + + align:start position:0% +promote in a society so this you know +when I look at this laptop I don't think + + align:start position:0% +when I look at this laptop I don't think + + + align:start position:0% +when I look at this laptop I don't think +oh this is you know beautiful this is an + + align:start position:0% +oh this is you know beautiful this is an + + + align:start position:0% +oh this is you know beautiful this is an +elegant this is functional I think this + + align:start position:0% +elegant this is functional I think this + + + align:start position:0% +elegant this is functional I think this +is how this company wants that + + align:start position:0% +is how this company wants that + + + align:start position:0% +is how this company wants that +look like and this is their long-lasting + + align:start position:0% +look like and this is their long-lasting + + + align:start position:0% +look like and this is their long-lasting +and material vision form of the world + + align:start position:0% +and material vision form of the world + + + align:start position:0% +and material vision form of the world +could look like for the long run + + align:start position:0% +could look like for the long run + + + align:start position:0% +could look like for the long run +eternally I think a lot of design + + align:start position:0% +eternally I think a lot of design + + + align:start position:0% +eternally I think a lot of design +thinking actually is pretty company's + + align:start position:0% +thinking actually is pretty company's + + + align:start position:0% +thinking actually is pretty company's +yeah that while we're looking at what + + align:start position:0% +yeah that while we're looking at what + + + align:start position:0% +yeah that while we're looking at what +they what we think their vision has been + + align:start position:0% +they what we think their vision has been + + + align:start position:0% +they what we think their vision has been +oh when we look at say math look and go + + align:start position:0% +oh when we look at say math look and go + + + align:start position:0% +oh when we look at say math look and go +out of them I looking to you and you + + align:start position:0% +out of them I looking to you and you + + + align:start position:0% +out of them I looking to you and you +know Apple wouldn't say and their design + + align:start position:0% +know Apple wouldn't say and their design + + + align:start position:0% +know Apple wouldn't say and their design +process they're going after users and + + align:start position:0% +process they're going after users and + + + align:start position:0% +process they're going after users and +seeing what what the users actually want + + align:start position:0% +seeing what what the users actually want + + + align:start position:0% +seeing what what the users actually want +awesome it's like a lot of looking both + + align:start position:0% +awesome it's like a lot of looking both + + + align:start position:0% +awesome it's like a lot of looking both +ways from up from a capitalist + + align:start position:0% +ways from up from a capitalist + + + align:start position:0% +ways from up from a capitalist +perspective look at it it's pretty much + + align:start position:0% +perspective look at it it's pretty much + + + align:start position:0% +perspective look at it it's pretty much +like okay one of the main fetching + + align:start position:0% +like okay one of the main fetching + + + align:start position:0% +like okay one of the main fetching +abilities how much does it cost me how + + align:start position:0% +abilities how much does it cost me how + + + align:start position:0% +abilities how much does it cost me how +long is going to take what can be the + + align:start position:0% +long is going to take what can be the + + + align:start position:0% +long is going to take what can be the +issues don't make it complicated some + + align:start position:0% +issues don't make it complicated some + + + align:start position:0% +issues don't make it complicated some +flights and why so funny because in the + + align:start position:0% +flights and why so funny because in the + + + align:start position:0% +flights and why so funny because in the +execution it's gonna be way more complex + + align:start position:0% +execution it's gonna be way more complex + + + align:start position:0% +execution it's gonna be way more complex +I'm not trying to deal with that and + + align:start position:0% +I'm not trying to deal with that and + + + align:start position:0% +I'm not trying to deal with that and +pretty much like okay I'll make it make + + align:start position:0% +pretty much like okay I'll make it make + + + align:start position:0% +pretty much like okay I'll make it make +sure it's slightly different in the my + + align:start position:0% +sure it's slightly different in the my + + + align:start position:0% +sure it's slightly different in the my +competitors make sure it follows the + + align:start position:0% +competitors make sure it follows the + + + align:start position:0% +competitors make sure it follows the +values of my company that's certain by + + align:start position:0% +values of my company that's certain by + + + align:start position:0% +values of my company that's certain by +the way and then when I market maybe you + + align:start position:0% +the way and then when I market maybe you + + + align:start position:0% +the way and then when I market maybe you +think it's something more than it + + align:start position:0% +think it's something more than it + + + align:start position:0% +think it's something more than it +actually is because they don't buy it + + align:start position:0% +actually is because they don't buy it + + + align:start position:0% +actually is because they don't buy it +because it's worth about I think maybe + + align:start position:0% +because it's worth about I think maybe + + + align:start position:0% +because it's worth about I think maybe +American Apparel and sort of what the + + align:start position:0% +American Apparel and sort of what the + + + align:start position:0% +American Apparel and sort of what the +internet like American Apparel a lot of + + align:start position:0% +internet like American Apparel a lot of + + + align:start position:0% +internet like American Apparel a lot of +brand jeans and some other companies + + align:start position:0% +brand jeans and some other companies + + + align:start position:0% +brand jeans and some other companies +they're like very heavy are their models + + align:start position:0% +they're like very heavy are their models + + + align:start position:0% +they're like very heavy are their models +are like particularly because they're + + align:start position:0% +are like particularly because they're + + + align:start position:0% +are like particularly because they're +based in the US and even though it might + + align:start position:0% +based in the US and even though it might + + + align:start position:0% +based in the US and even though it might +be less expensive to sort of like build + + align:start position:0% +be less expensive to sort of like build + + + align:start position:0% +be less expensive to sort of like build +and like manufacture your jeans or your + + align:start position:0% +and like manufacture your jeans or your + + + align:start position:0% +and like manufacture your jeans or your +t-shirts for example outside of Los + + align:start position:0% +t-shirts for example outside of Los + + + align:start position:0% +t-shirts for example outside of Los +Angeles + + align:start position:0% +Angeles + + + align:start position:0% +Angeles +you lose sort of other factors which is + + align:start position:0% +you lose sort of other factors which is + + + align:start position:0% +you lose sort of other factors which is +sort of like being able to say like + + align:start position:0% +sort of like being able to say like + + + align:start position:0% +sort of like being able to say like +maybe say well wha but also like you + + align:start position:0% +maybe say well wha but also like you + + + align:start position:0% +maybe say well wha but also like you +gain sort of production speed and like + + align:start position:0% +gain sort of production speed and like + + + align:start position:0% +gain sort of production speed and like +all these things of our team is talking + + align:start position:0% +all these things of our team is talking + + + align:start position:0% +all these things of our team is talking +about some kind of a couple you design + + align:start position:0% +about some kind of a couple you design + + + align:start position:0% +about some kind of a couple you design +in the manufacturing processes it like + + align:start position:0% +in the manufacturing processes it like + + + align:start position:0% +in the manufacturing processes it like +people in here but at the end of the day + + align:start position:0% +people in here but at the end of the day + + + align:start position:0% +people in here but at the end of the day +I think you do a cost-benefit analysis + + align:start position:0% +I think you do a cost-benefit analysis + + + align:start position:0% +I think you do a cost-benefit analysis +in Stalag Martine said and then just + + align:start position:0% +in Stalag Martine said and then just + + + align:start position:0% +in Stalag Martine said and then just +make sure that your company values is in + + align:start position:0% +make sure that your company values is in + + + align:start position:0% +make sure that your company values is in +line with sort of the product and like + + align:start position:0% +line with sort of the product and like + + + align:start position:0% +line with sort of the product and like +how do you want people to interface with + + align:start position:0% +how do you want people to interface with + + + align:start position:0% +how do you want people to interface with +the world through your problem going off + + align:start position:0% +the world through your problem going off + + + align:start position:0% +the world through your problem going off +that I'm curious how much of those + + align:start position:0% +that I'm curious how much of those + + + align:start position:0% +that I'm curious how much of those +advantages that you get from producing + + align:start position:0% +advantages that you get from producing + + + align:start position:0% +advantages that you get from producing +in the US can query like whatever + + align:start position:0% +in the US can query like whatever + + + align:start position:0% +in the US can query like whatever +they're kind of gimmick is how + + align:start position:0% +they're kind of gimmick is how + + + align:start position:0% +they're kind of gimmick is how +like along those last like American + + align:start position:0% +like along those last like American + + + align:start position:0% +like along those last like American +Apparel just closed all their stories + + align:start position:0% +Apparel just closed all their stories + + + align:start position:0% +Apparel just closed all their stories +like does that mean that that approach + + align:start position:0% +like does that mean that that approach + + + align:start position:0% +like does that mean that that approach +isn't sustainable and that they should + + align:start position:0% +isn't sustainable and that they should + + + align:start position:0% +isn't sustainable and that they should +have taken another look at outsourcing + + align:start position:0% +have taken another look at outsourcing + + + align:start position:0% +have taken another look at outsourcing +or is it just I mean there are other + + align:start position:0% +or is it just I mean there are other + + + align:start position:0% +or is it just I mean there are other +factors contributing to it but is that + + align:start position:0% +factors contributing to it but is that + + + align:start position:0% +factors contributing to it but is that +like do these companies have to pick + + align:start position:0% +like do these companies have to pick + + + align:start position:0% +like do these companies have to pick +like what society will watch as their + + align:start position:0% +like what society will watch as their + + + align:start position:0% +like what society will watch as their +special sauce and hope that it wants + + align:start position:0% +special sauce and hope that it wants + + + align:start position:0% +special sauce and hope that it wants +long enough or are they eventually going + + align:start position:0% +long enough or are they eventually going + + + align:start position:0% +long enough or are they eventually going +to need to think about these + + align:start position:0% +to need to think about these + + + align:start position:0% +to need to think about these +alternatives they definitely should + + align:start position:0% +alternatives they definitely should + + + align:start position:0% +alternatives they definitely should +consider the alternatives but I mean + + align:start position:0% +consider the alternatives but I mean + + + align:start position:0% +consider the alternatives but I mean +when at least for the American girl like + + align:start position:0% +when at least for the American girl like + + + align:start position:0% +when at least for the American girl like +you were saying yeah there's probably a + + align:start position:0% +you were saying yeah there's probably a + + + align:start position:0% +you were saying yeah there's probably a +ton of factors and I think just to + + align:start position:0% +ton of factors and I think just to + + + align:start position:0% +ton of factors and I think just to +answer that question we just need more + + align:start position:0% +answer that question we just need more + + + align:start position:0% +answer that question we just need more +data so we need to somehow control for + + align:start position:0% +data so we need to somehow control for + + + align:start position:0% +data so we need to somehow control for +the type of industry the time period the + + align:start position:0% +the type of industry the time period the + + + align:start position:0% +the type of industry the time period the +location etc etc and then you could + + align:start position:0% +location etc etc and then you could + + + align:start position:0% +location etc etc and then you could +compare just like based on the + + align:start position:0% +compare just like based on the + + + align:start position:0% +compare just like based on the +information that we have the question we + + align:start position:0% +information that we have the question we + + + align:start position:0% +information that we have the question we +just don't have those numbers to back up + + align:start position:0% +just don't have those numbers to back up + + + align:start position:0% +just don't have those numbers to back up +the other side or another example I + + align:start position:0% +the other side or another example I + + + align:start position:0% +the other side or another example I +think that this was written before Zahra + + align:start position:0% +think that this was written before Zahra + + + align:start position:0% +think that this was written before Zahra +came under fire for a bunch of basically + + align:start position:0% +came under fire for a bunch of basically + + + align:start position:0% +came under fire for a bunch of basically +human oh no I can't even afraid I can't + + align:start position:0% +human oh no I can't even afraid I can't + + + align:start position:0% +human oh no I can't even afraid I can't +articulate it well or Martine of you + + align:start position:0% +articulate it well or Martine of you + + + align:start position:0% +articulate it well or Martine of you +give mom and you it's it's an example + + align:start position:0% +give mom and you it's it's an example + + + align:start position:0% +give mom and you it's it's an example +that Suzanne Berger uses and the point + + align:start position:0% +that Suzanne Berger uses and the point + + + align:start position:0% +that Suzanne Berger uses and the point +about Zara is that by locating its + + align:start position:0% +about Zara is that by locating its + + + align:start position:0% +about Zara is that by locating its +production facilities very close to his + + align:start position:0% +production facilities very close to his + + + align:start position:0% +production facilities very close to his +markets is able to move from production + + align:start position:0% +markets is able to move from production + + + align:start position:0% +markets is able to move from production +to its sale system in a very very short + + align:start position:0% +to its sale system in a very very short + + + align:start position:0% +to its sale system in a very very short +period of time so by tracking fashion + + align:start position:0% +period of time so by tracking fashion + + + align:start position:0% +period of time so by tracking fashion +markets and what appears to be moving as + + align:start position:0% +markets and what appears to be moving as + + + align:start position:0% +markets and what appears to be moving as +selling is able to shift its production + + align:start position:0% +selling is able to shift its production + + + align:start position:0% +selling is able to shift its production +system quickly on to kind of new styles + + align:start position:0% +system quickly on to kind of new styles + + + align:start position:0% +system quickly on to kind of new styles +and emerge whereas if you're shipping + + align:start position:0% +and emerge whereas if you're shipping + + + align:start position:0% +and emerge whereas if you're shipping +that style across a 8,000 miles of ocean + + align:start position:0% +that style across a 8,000 miles of ocean + + + align:start position:0% +that style across a 8,000 miles of ocean +in a container ship that's moving + + align:start position:0% +in a container ship that's moving + + + align:start position:0% +in a container ship that's moving +that's right you're not in the game + + align:start position:0% +that's right you're not in the game + + + align:start position:0% +that's right you're not in the game +right so as our has figured out how to + + align:start position:0% +right so as our has figured out how to + + + align:start position:0% +right so as our has figured out how to +keep that relationship between + + align:start position:0% +keep that relationship between + + + align:start position:0% +keep that relationship between +production facility market and sales + + align:start position:0% +production facility market and sales + + + align:start position:0% +production facility market and sales +facility very tight and therefore be + + align:start position:0% +facility very tight and therefore be + + + align:start position:0% +facility very tight and therefore be +able to serve emerging markets and you + + align:start position:0% +able to serve emerging markets and you + + + align:start position:0% +able to serve emerging markets and you +know fashion is so much different in + + align:start position:0% +know fashion is so much different in + + + align:start position:0% +know fashion is so much different in +other areas but I think is still there + + align:start position:0% +other areas but I think is still there + + + align:start position:0% +other areas but I think is still there +but serve emerging markets very quickly + + align:start position:0% +but serve emerging markets very quickly + + + align:start position:0% +but serve emerging markets very quickly +so rising to you market opportunities + + align:start position:0% +so rising to you market opportunities + + + align:start position:0% +so rising to you market opportunities +integration roots of time how's that + + align:start position:0% +integration roots of time how's that + + + align:start position:0% +integration roots of time how's that +Martina said I was like pretty much what + + align:start position:0% +Martina said I was like pretty much what + + + align:start position:0% +Martina said I was like pretty much what +they do it's like big go into the + + align:start position:0% +they do it's like big go into the + + + align:start position:0% +they do it's like big go into the +Fashion Week like oh there's a really + + align:start position:0% +Fashion Week like oh there's a really + + + align:start position:0% +Fashion Week like oh there's a really +expensive thing we're gonna do is we're + + align:start position:0% +expensive thing we're gonna do is we're + + + align:start position:0% +expensive thing we're gonna do is we're +gonna find a very quick doing it they + + align:start position:0% +gonna find a very quick doing it they + + + align:start position:0% +gonna find a very quick doing it they +have it on the market like by two weeks + + align:start position:0% +have it on the market like by two weeks + + + align:start position:0% +have it on the market like by two weeks +pretty much of a like rapidly design and + + align:start position:0% +pretty much of a like rapidly design and + + + align:start position:0% +pretty much of a like rapidly design and +they go for a low price point and + + align:start position:0% +they go for a low price point and + + + align:start position:0% +they go for a low price point and +they'll put it into the market and then + + align:start position:0% +they'll put it into the market and then + + + align:start position:0% +they'll put it into the market and then +people will buy it but you're not really + + align:start position:0% +people will buy it but you're not really + + + align:start position:0% +people will buy it but you're not really +buying it because it's like you're not + + align:start position:0% +buying it because it's like you're not + + + align:start position:0% +buying it because it's like you're not +mine for value you're buying because + + align:start position:0% +mine for value you're buying because + + + align:start position:0% +mine for value you're buying because +this is trendy and I always spend that + + align:start position:0% +this is trendy and I always spend that + + + align:start position:0% +this is trendy and I always spend that +much and that's kind of their value + + align:start position:0% +much and that's kind of their value + + + align:start position:0% +much and that's kind of their value +problem right now because they're + + align:start position:0% +problem right now because they're + + + align:start position:0% +problem right now because they're +usually like slightly more than H&M but + + align:start position:0% +usually like slightly more than H&M but + + + align:start position:0% +usually like slightly more than H&M but +it just like that right model for like I + + align:start position:0% +it just like that right model for like I + + + align:start position:0% +it just like that right model for like I +want to buy a good amount now from like + + align:start position:0% +want to buy a good amount now from like + + + align:start position:0% +want to buy a good amount now from like +ten years ago said some people early + + align:start position:0% +ten years ago said some people early + + + align:start position:0% +ten years ago said some people early +because there's our there's H&M but like + + align:start position:0% +because there's our there's H&M but like + + + align:start position:0% +because there's our there's H&M but like +there's not too much of a difference and + + align:start position:0% +there's not too much of a difference and + + + align:start position:0% +there's not too much of a difference and +I'm pretty sure they have different + + align:start position:0% +I'm pretty sure they have different + + + align:start position:0% +I'm pretty sure they have different +products so much somebody might be like + + align:start position:0% +products so much somebody might be like + + + align:start position:0% +products so much somebody might be like +oh I really like this sweater from like + + align:start position:0% +oh I really like this sweater from like + + + align:start position:0% +oh I really like this sweater from like +bizarra so I'll definitely go that way I + + align:start position:0% +bizarra so I'll definitely go that way I + + + align:start position:0% +bizarra so I'll definitely go that way I +think it's a very I wouldn't debate that + + align:start position:0% +think it's a very I wouldn't debate that + + + align:start position:0% +think it's a very I wouldn't debate that +there's a very small percentage they'll + + align:start position:0% +there's a very small percentage they'll + + + align:start position:0% +there's a very small percentage they'll +be like oh I'm totally never gonna buy + + align:start position:0% +be like oh I'm totally never gonna buy + + + align:start position:0% +be like oh I'm totally never gonna buy +from the store again or I'm totally not + + align:start position:0% +from the store again or I'm totally not + + + align:start position:0% +from the store again or I'm totally not +gonna buy from the store again and then + + align:start position:0% +gonna buy from the store again and then + + + align:start position:0% +gonna buy from the store again and then +not go back to buy from it like two + + align:start position:0% +not go back to buy from it like two + + + align:start position:0% +not go back to buy from it like two +weeks later so I'm gonna bring us back + + align:start position:0% +weeks later so I'm gonna bring us back + + + align:start position:0% +weeks later so I'm gonna bring us back +the mats inside I'll go on offer to the + + align:start position:0% +the mats inside I'll go on offer to the + + + align:start position:0% +the mats inside I'll go on offer to the +fashion back this is more fundamental do + + align:start position:0% +fashion back this is more fundamental do + + + align:start position:0% +fashion back this is more fundamental do +you have some closing point you want to + + align:start position:0% +you have some closing point you want to + + + align:start position:0% +you have some closing point you want to +make on susan's but what I think is + + align:start position:0% +make on susan's but what I think is + + + align:start position:0% +make on susan's but what I think is +really key I think one key point that + + align:start position:0% +really key I think one key point that + + + align:start position:0% +really key I think one key point that +maybe get as much time to talk on is + + align:start position:0% +maybe get as much time to talk on is + + + align:start position:0% +maybe get as much time to talk on is +that maybe we have as Americans you know + + align:start position:0% +that maybe we have as Americans you know + + + align:start position:0% +that maybe we have as Americans you know +his idea of a birthright to being at the + + align:start position:0% +his idea of a birthright to being at the + + + align:start position:0% +his idea of a birthright to being at the +forefront of innovation and really + + align:start position:0% +forefront of innovation and really + + + align:start position:0% +forefront of innovation and really +pointing out that no one who's + + align:start position:0% +pointing out that no one who's + + + align:start position:0% +pointing out that no one who's +complacent and sitting + + align:start position:0% +complacent and sitting + + + align:start position:0% +complacent and sitting +or we'll stay in that position I think + + align:start position:0% +or we'll stay in that position I think + + + align:start position:0% +or we'll stay in that position I think +there's a good truck contrast to me may + + align:start position:0% +there's a good truck contrast to me may + + + align:start position:0% +there's a good truck contrast to me may +teach me her ideas on outsourcing + + align:start position:0% +teach me her ideas on outsourcing + + + align:start position:0% +teach me her ideas on outsourcing +where's it's versus burgers good good + + align:start position:0% +where's it's versus burgers good good + + + align:start position:0% +where's it's versus burgers good good +point + + align:start position:0% + + + + align:start position:0% + +all right that brings us to our closing + + align:start position:0% +all right that brings us to our closing + + + align:start position:0% +all right that brings us to our closing +reading this is what about might these + + align:start position:0% +reading this is what about might these + + + align:start position:0% +reading this is what about might these +great Provost Joel Moses who was deeply + + align:start position:0% +great Provost Joel Moses who was deeply + + + align:start position:0% +great Provost Joel Moses who was deeply +involved in the early and indeed later + + align:start position:0% +involved in the early and indeed later + + + align:start position:0% +involved in the early and indeed later +stages of the computing revolution so + + align:start position:0% +stages of the computing revolution so + + + align:start position:0% +stages of the computing revolution so +this is a young Joel at project Mac at + + align:start position:0% +this is a young Joel at project Mac at + + + align:start position:0% +this is a young Joel at project Mac at +MIT which just might ease implementation + + align:start position:0% +MIT which just might ease implementation + + + align:start position:0% +MIT which just might ease implementation +engine for a lot of the early computing + + align:start position:0% +engine for a lot of the early computing + + + align:start position:0% +engine for a lot of the early computing +advances so Jules steps back and likes + + align:start position:0% +advances so Jules steps back and likes + + + align:start position:0% +advances so Jules steps back and likes +this kind of fun piece which I wanted to + + align:start position:0% +this kind of fun piece which I wanted to + + + align:start position:0% +this kind of fun piece which I wanted to +throw in here at the end to pick up our + + align:start position:0% +throw in here at the end to pick up our + + + align:start position:0% +throw in here at the end to pick up our +determinism theme one more time + + align:start position:0% +determinism theme one more time + + + align:start position:0% +determinism theme one more time +we've been talking about different kinds + + align:start position:0% +we've been talking about different kinds + + + align:start position:0% +we've been talking about different kinds +of innovation systems and how different + + align:start position:0% +of innovation systems and how different + + + align:start position:0% +of innovation systems and how different +countries have varieties of capitalism + + align:start position:0% +countries have varieties of capitalism + + + align:start position:0% +countries have varieties of capitalism +and varieties of innovation systems and + + align:start position:0% +and varieties of innovation systems and + + + align:start position:0% +and varieties of innovation systems and +Joel takes us back a step and gives us + + align:start position:0% +Joel takes us back a step and gives us + + + align:start position:0% +Joel takes us back a step and gives us +more of a 10,000 foot kind of look which + + align:start position:0% +more of a 10,000 foot kind of look which + + + align:start position:0% +more of a 10,000 foot kind of look which +I was you know I was I've always been + + align:start position:0% +I was you know I was I've always been + + + align:start position:0% +I was you know I was I've always been +intrigued with he argues that there are + + align:start position:0% +intrigued with he argues that there are + + + align:start position:0% +intrigued with he argues that there are +three fundamentally different design + + align:start position:0% +three fundamentally different design + + + align:start position:0% +three fundamentally different design +methodologies so this is a design + + align:start position:0% +methodologies so this is a design + + + align:start position:0% +methodologies so this is a design +methodology and the societal sense + + align:start position:0% +methodology and the societal sense + + + align:start position:0% +methodology and the societal sense +rather than engineering design that map + + align:start position:0% +rather than engineering design that map + + + align:start position:0% +rather than engineering design that map +he was leading us to earlier and he + + align:start position:0% +he was leading us to earlier and he + + + align:start position:0% +he was leading us to earlier and he +argues that historically the US has used + + align:start position:0% +argues that historically the US has used + + + align:start position:0% +argues that historically the US has used +what he calls a tree and branch + + align:start position:0% +what he calls a tree and branch + + + align:start position:0% +what he calls a tree and branch +organization will attempt which creates + + align:start position:0% +organization will attempt which creates + + + align:start position:0% +organization will attempt which creates +very hierarchical firms and he argues + + align:start position:0% +very hierarchical firms and he argues + + + align:start position:0% +very hierarchical firms and he argues +that this very hierarchical system right + + align:start position:0% +that this very hierarchical system right + + + align:start position:0% +that this very hierarchical system right +and you can picture what the + + align:start position:0% +and you can picture what the + + + align:start position:0% +and you can picture what the +organization chart looks like it's like + + align:start position:0% +organization chart looks like it's like + + + align:start position:0% +organization chart looks like it's like +a tree right top management you know + + align:start position:0% +a tree right top management you know + + + align:start position:0% +a tree right top management you know +all the way down through many different + + align:start position:0% +all the way down through many different + + + align:start position:0% +all the way down through many different +hierarchies of levels that that fits a + + align:start position:0% +hierarchies of levels that that fits a + + + align:start position:0% +hierarchies of levels that that fits a +mass production economy this is the kind + + align:start position:0% +mass production economy this is the kind + + + align:start position:0% +mass production economy this is the kind +of economy that was compelled coming out + + align:start position:0% +of economy that was compelled coming out + + + align:start position:0% +of economy that was compelled coming out +of the Industrial Revolution and its + + align:start position:0% +of the Industrial Revolution and its + + + align:start position:0% +of the Industrial Revolution and its +organizing for manufacturing at a + + align:start position:0% +organizing for manufacturing at a + + + align:start position:0% +organizing for manufacturing at a +national scale for national markets + + align:start position:0% +national scale for national markets + + + align:start position:0% +national scale for national markets +where a lot of vertical integration is + + align:start position:0% +where a lot of vertical integration is + + + align:start position:0% +where a lot of vertical integration is +required so think about the big three us + + align:start position:0% +required so think about the big three us + + + align:start position:0% +required so think about the big three us +car companies now many makes an + + align:start position:0% +car companies now many makes an + + + align:start position:0% +car companies now many makes an +interesting additional point which is + + align:start position:0% +interesting additional point which is + + + align:start position:0% +interesting additional point which is +this by the way it's an Aristotelian a + + align:start position:0% +this by the way it's an Aristotelian a + + + align:start position:0% +this by the way it's an Aristotelian a +hierarchy of ordered knowledge right + + align:start position:0% +hierarchy of ordered knowledge right + + + align:start position:0% +hierarchy of ordered knowledge right +this is the way in which Western thought + + align:start position:0% +this is the way in which Western thought + + + align:start position:0% +this is the way in which Western thought +are organizes science right that's what + + align:start position:0% +are organizes science right that's what + + + align:start position:0% +are organizes science right that's what +Aristotle is doing he's creating these + + align:start position:0% +Aristotle is doing he's creating these + + + align:start position:0% +Aristotle is doing he's creating these +tree branch systems surprise it shows up + + align:start position:0% +tree branch systems surprise it shows up + + + align:start position:0% +tree branch systems surprise it shows up +in industrial organization in the West + + align:start position:0% +in industrial organization in the West + + + align:start position:0% +in industrial organization in the West +but he argues that the tree and branch + + align:start position:0% +but he argues that the tree and branch + + + align:start position:0% +but he argues that the tree and branch +hierarchy means tremendous in and + + align:start position:0% +hierarchy means tremendous in and + + + align:start position:0% +hierarchy means tremendous in and +flexibility and great difficulty and + + align:start position:0% +flexibility and great difficulty and + + + align:start position:0% +flexibility and great difficulty and +managing change because you've got to + + align:start position:0% +managing change because you've got to + + + align:start position:0% +managing change because you've got to +bring all those different systems all + + align:start position:0% +bring all those different systems all + + + align:start position:0% +bring all those different systems all +those different levels in line in order + + align:start position:0% +those different levels in line in order + + + align:start position:0% +those different levels in line in order +to pursue change so the second design + + align:start position:0% +to pursue change so the second design + + + align:start position:0% +to pursue change so the second design +methodology is around what he calls a + + align:start position:0% +methodology is around what he calls a + + + align:start position:0% +methodology is around what he calls a +layer system and he argues that Japan's + + align:start position:0% +layer system and he argues that Japan's + + + align:start position:0% +layer system and he argues that Japan's +incredible success of the 70s and 80s + + align:start position:0% +incredible success of the 70s and 80s + + + align:start position:0% +incredible success of the 70s and 80s +it's not just a different industrial + + align:start position:0% +it's not just a different industrial + + + align:start position:0% +it's not just a different industrial +right a quality production it's deeper + + align:start position:0% +right a quality production it's deeper + + + align:start position:0% +right a quality production it's deeper +than that there's a whole social + + align:start position:0% +than that there's a whole social + + + align:start position:0% +than that there's a whole social +organization so issues that's coming + + align:start position:0% +organization so issues that's coming + + + align:start position:0% +organization so issues that's coming +with it and it's tough it's tough on you + + align:start position:0% +with it and it's tough it's tough on you + + + align:start position:0% +with it and it's tough it's tough on you +you were driving towards some of these + + align:start position:0% +you were driving towards some of these + + + align:start position:0% +you were driving towards some of these +points I think so + + align:start position:0% +points I think so + + + align:start position:0% +points I think so +in Japan's system there are separate + + align:start position:0% +in Japan's system there are separate + + + align:start position:0% +in Japan's system there are separate +kind of layered levels and you tend to + + align:start position:0% +kind of layered levels and you tend to + + + align:start position:0% +kind of layered levels and you tend to +move through your career with your age + + align:start position:0% +move through your career with your age + + + align:start position:0% +move through your career with your age +cohort and as a group you move from + + align:start position:0% +cohort and as a group you move from + + + align:start position:0% +cohort and as a group you move from +level to level and there's obviously + + align:start position:0% +level to level and there's obviously + + + align:start position:0% +level to level and there's obviously +several levels here + + align:start position:0% +several levels here + + + align:start position:0% +several levels here +it's much less tree and branch + + align:start position:0% +it's much less tree and branch + + + align:start position:0% +it's much less tree and branch +hierarchical it is pretty flat within + + align:start position:0% +hierarchical it is pretty flat within + + + align:start position:0% +hierarchical it is pretty flat within +that age cohort right and you tend to + + align:start position:0% +that age cohort right and you tend to + + + align:start position:0% +that age cohort right and you tend to +know that you're going to move with your + + align:start position:0% +know that you're going to move with your + + + align:start position:0% +know that you're going to move with your +level in two successive positions so it + + align:start position:0% +level in two successive positions so it + + + align:start position:0% +level in two successive positions so it +forces a significant amount of consensus + + align:start position:0% +forces a significant amount of consensus + + + align:start position:0% +forces a significant amount of consensus +right so Joel's + + align:start position:0% +right so Joel's + + + align:start position:0% +right so Joel's +interesting comparison is you know this + + align:start position:0% +interesting comparison is you know this + + + align:start position:0% +interesting comparison is you know this +is Plato's Republic the philosopher king + + align:start position:0% +is Plato's Republic the philosopher king + + + align:start position:0% +is Plato's Republic the philosopher king +the Guardians the citizens those are + + align:start position:0% +the Guardians the citizens those are + + + align:start position:0% +the Guardians the citizens those are +kind of layers so not an Aristotelian + + align:start position:0% +kind of layers so not an Aristotelian + + + align:start position:0% +kind of layers so not an Aristotelian +but a they play tonic model and then he + + align:start position:0% +but a they play tonic model and then he + + + align:start position:0% +but a they play tonic model and then he +says there's a third right and this is + + align:start position:0% +says there's a third right and this is + + + align:start position:0% +says there's a third right and this is +the network model that the u.s. nurtured + + align:start position:0% +the network model that the u.s. nurtured + + + align:start position:0% +the network model that the u.s. nurtured +coming out of the IP refuge which is + + align:start position:0% +coming out of the IP refuge which is + + + align:start position:0% +coming out of the IP refuge which is +much flatter right much less + + align:start position:0% +much flatter right much less + + + align:start position:0% +much flatter right much less +hierarchical not even layer right it's + + align:start position:0% +hierarchical not even layer right it's + + + align:start position:0% +hierarchical not even layer right it's +pretty flat and it's driven by the kind + + align:start position:0% +pretty flat and it's driven by the kind + + + align:start position:0% +pretty flat and it's driven by the kind +of collaborative group innovation + + align:start position:0% +of collaborative group innovation + + + align:start position:0% +of collaborative group innovation +systems that are required for the + + align:start position:0% +systems that are required for the + + + align:start position:0% +systems that are required for the +development of the IT sector that a + + align:start position:0% +development of the IT sector that a + + + align:start position:0% +development of the IT sector that a +legit ranch hierarchy is just not going + + align:start position:0% +legit ranch hierarchy is just not going + + + align:start position:0% +legit ranch hierarchy is just not going +to work in that IT world which requires + + align:start position:0% +to work in that IT world which requires + + + align:start position:0% +to work in that IT world which requires +a tremendous amount of homos + + align:start position:0% +a tremendous amount of homos + + + align:start position:0% +a tremendous amount of homos +democratization workforce right so back + + align:start position:0% +democratization workforce right so back + + + align:start position:0% +democratization workforce right so back +Marteen to your to your Andy Grove + + align:start position:0% +Marteen to your to your Andy Grove + + + align:start position:0% +Marteen to your to your Andy Grove +analogy when the leaders of Intel when + + align:start position:0% +analogy when the leaders of Intel when + + + align:start position:0% +analogy when the leaders of Intel when +Bob Noyce and wove board more betting on + + align:start position:0% +Bob Noyce and wove board more betting on + + + align:start position:0% +Bob Noyce and wove board more betting on +Intel right there no offices right + + align:start position:0% +Intel right there no offices right + + + align:start position:0% +Intel right there no offices right +everybody's got a cubicle including + + align:start position:0% +everybody's got a cubicle including + + + align:start position:0% +everybody's got a cubicle including +noise and more rope right so + + align:start position:0% + + + + align:start position:0% + +Joel's complaint is that I mean the + + align:start position:0% +Joel's complaint is that I mean the + + + align:start position:0% +Joel's complaint is that I mean the +network model Joel argues is actually + + align:start position:0% +network model Joel argues is actually + + + align:start position:0% +network model Joel argues is actually +much faster and much more flexible and + + align:start position:0% +much faster and much more flexible and + + + align:start position:0% +much faster and much more flexible and +much more subject to change than fun the + + align:start position:0% +much more subject to change than fun the + + + align:start position:0% +much more subject to change than fun the +layered model that Japan presented and + + align:start position:0% +layered model that Japan presented and + + + align:start position:0% +layered model that Japan presented and +so you start thinking here geez no + + align:start position:0% +so you start thinking here geez no + + + align:start position:0% +so you start thinking here geez no +wonder the US auto ministry got rolled + + align:start position:0% +wonder the US auto ministry got rolled + + + align:start position:0% +wonder the US auto ministry got rolled +when it came up against Japan's layered + + align:start position:0% +when it came up against Japan's layered + + + align:start position:0% +when it came up against Japan's layered +model and then you start thinking oh no + + align:start position:0% +model and then you start thinking oh no + + + align:start position:0% +model and then you start thinking oh no +wonder Japan is the IT revolution if the + + align:start position:0% +wonder Japan is the IT revolution if the + + + align:start position:0% +wonder Japan is the IT revolution if the +organizational model required this + + align:start position:0% +organizational model required this + + + align:start position:0% +organizational model required this +network now what these are highly + + align:start position:0% +network now what these are highly + + + align:start position:0% +network now what these are highly +speculative we'll never beat these right + + align:start position:0% +speculative we'll never beat these right + + + align:start position:0% +speculative we'll never beat these right +they're really only for discussion + + align:start position:0% +they're really only for discussion + + + align:start position:0% +they're really only for discussion +purposes all of us kind of know that + + align:start position:0% +purposes all of us kind of know that + + + align:start position:0% +purposes all of us kind of know that +they're more complex stories be like wow + + align:start position:0% +they're more complex stories be like wow + + + align:start position:0% +they're more complex stories be like wow +but I think there is an idea right about + + align:start position:0% +but I think there is an idea right about + + + align:start position:0% +but I think there is an idea right about +the relationship between social + + align:start position:0% +the relationship between social + + + align:start position:0% +the relationship between social +organization and the kind of industrial + + align:start position:0% +organization and the kind of industrial + + + align:start position:0% +organization and the kind of industrial +developments that your society is going + + align:start position:0% +developments that your society is going + + + align:start position:0% +developments that your society is going +through and the kind of organizational + + align:start position:0% +through and the kind of organizational + + + align:start position:0% +through and the kind of organizational +models as those compel joel's great + + align:start position:0% +models as those compel joel's great + + + align:start position:0% +models as those compel joel's great +complaint is that engineering lacks the + + align:start position:0% +complaint is that engineering lacks the + + + align:start position:0% +complaint is that engineering lacks the +models to be able to grasp these + + align:start position:0% +models to be able to grasp these + + + align:start position:0% +models to be able to grasp these +different organizational structures + + align:start position:0% +different organizational structures + + + align:start position:0% +different organizational structures +though that you can't really fit that + + align:start position:0% +though that you can't really fit that + + + align:start position:0% +though that you can't really fit that +within a traditional kind of engineering + + align:start position:0% +within a traditional kind of engineering + + + align:start position:0% +within a traditional kind of engineering +analysis and that engineering therefore + + align:start position:0% +analysis and that engineering therefore + + + align:start position:0% +analysis and that engineering therefore +needs to rethink this that's part of the + + align:start position:0% +needs to rethink this that's part of the + + + align:start position:0% +needs to rethink this that's part of the +reason why he's a major leader might + + align:start position:0% +reason why he's a major leader might + + + align:start position:0% +reason why he's a major leader might +ease engineering systems division right + + align:start position:0% +ease engineering systems division right + + + align:start position:0% +ease engineering systems division right +which of course has now been closed but + + align:start position:0% +which of course has now been closed but + + + align:start position:0% +which of course has now been closed but +that's part of what Joel and some of his + + align:start position:0% +that's part of what Joel and some of his + + + align:start position:0% +that's part of what Joel and some of his +colleagues are trying to do when they + + align:start position:0% +colleagues are trying to do when they + + + align:start position:0% +colleagues are trying to do when they +set up ESD I mean that's you know I just + + align:start position:0% +set up ESD I mean that's you know I just + + + align:start position:0% +set up ESD I mean that's you know I just +want to kind of close out by saying that + + align:start position:0% +want to kind of close out by saying that + + + align:start position:0% +want to kind of close out by saying that +there's another thing that we'll need to + + align:start position:0% +there's another thing that we'll need to + + + align:start position:0% +there's another thing that we'll need to +consider as we move into next week's + + align:start position:0% +consider as we move into next week's + + + align:start position:0% +consider as we move into next week's +class that the whole nature of + + align:start position:0% +class that the whole nature of + + + align:start position:0% +class that the whole nature of +competition is changing and + + align:start position:0% +competition is changing and + + + align:start position:0% +competition is changing and +manufacturing that is no longer a world + + align:start position:0% +manufacturing that is no longer a world + + + align:start position:0% +manufacturing that is no longer a world +of manufacturing Goods is a world of + + align:start position:0% +of manufacturing Goods is a world of + + + align:start position:0% +of manufacturing Goods is a world of +manufactured goods that are fused but I + + align:start position:0% +manufactured goods that are fused but I + + + align:start position:0% +manufactured goods that are fused but I +t's technologies that in turn are + + align:start position:0% +t's technologies that in turn are + + + align:start position:0% +t's technologies that in turn are +service delivery models so that + + align:start position:0% +service delivery models so that + + + align:start position:0% +service delivery models so that +or fusion of services and manufacturing + + align:start position:0% +or fusion of services and manufacturing + + + align:start position:0% +or fusion of services and manufacturing +going one that makes some of the stories + + align:start position:0% +going one that makes some of the stories + + + align:start position:0% +going one that makes some of the stories +we've been talking about today it's more + + align:start position:0% +we've been talking about today it's more + + + align:start position:0% +we've been talking about today it's more +complicated in past decades the story + + align:start position:0% +complicated in past decades the story + + + align:start position:0% +complicated in past decades the story +was quality now there's a whole level of + + align:start position:0% +was quality now there's a whole level of + + + align:start position:0% +was quality now there's a whole level of +customization and speed and customer + + align:start position:0% +customization and speed and customer + + + align:start position:0% +customization and speed and customer +responsiveness that we have to think + + align:start position:0% +responsiveness that we have to think + + + align:start position:0% +responsiveness that we have to think +about as well and your ability to get on + + align:start position:0% +about as well and your ability to get on + + + align:start position:0% +about as well and your ability to get on +top of those as well as on quality + + align:start position:0% +top of those as well as on quality + + + align:start position:0% +top of those as well as on quality +becomes key it's not simply the best + + align:start position:0% +becomes key it's not simply the best + + + align:start position:0% +becomes key it's not simply the best +technology but it's the best technology + + align:start position:0% +technology but it's the best technology + + + align:start position:0% +technology but it's the best technology +plus the best business models and + + align:start position:0% +plus the best business models and + + + align:start position:0% +plus the best business models and +delivery models didn't have to be + + align:start position:0% +delivery models didn't have to be + + + align:start position:0% +delivery models didn't have to be +thought about you know there used to be + + align:start position:0% +thought about you know there used to be + + + align:start position:0% +thought about you know there used to be +trade in goods traded product now is + + align:start position:0% +trade in goods traded product now is + + + align:start position:0% +trade in goods traded product now is +traded all kinds of knowledge management + + align:start position:0% +traded all kinds of knowledge management + + + align:start position:0% +traded all kinds of knowledge management +and services they're tied to these + + align:start position:0% +and services they're tied to these + + + align:start position:0% +and services they're tied to these +products that becomes critical factors + + align:start position:0% +products that becomes critical factors + + + align:start position:0% +products that becomes critical factors +in your ability to in the past it was + + align:start position:0% +in your ability to in the past it was + + + align:start position:0% +in your ability to in the past it was +that workforce skills side now it's much + + align:start position:0% +that workforce skills side now it's much + + + align:start position:0% +that workforce skills side now it's much +more continuous learning in your course + + align:start position:0% +more continuous learning in your course + + + align:start position:0% +more continuous learning in your course +then it was low cost of capital now its + + align:start position:0% +then it was low cost of capital now its + + + align:start position:0% +then it was low cost of capital now its +efficiency in all the financial services + + align:start position:0% +efficiency in all the financial services + + + align:start position:0% +efficiency in all the financial services +stages that you've got to get through + + align:start position:0% +stages that you've got to get through + + + align:start position:0% +stages that you've got to get through +those right not just the initial capital + + align:start position:0% +those right not just the initial capital + + + align:start position:0% +those right not just the initial capital +goods so and there's a whole evolution + + align:start position:0% +goods so and there's a whole evolution + + + align:start position:0% +goods so and there's a whole evolution +of intangible capital as well so there's + + align:start position:0% +of intangible capital as well so there's + + + align:start position:0% +of intangible capital as well so there's +a whole new set of factors that's coming + + align:start position:0% +a whole new set of factors that's coming + + + align:start position:0% +a whole new set of factors that's coming +into the manufacturing world that we've + + align:start position:0% +into the manufacturing world that we've + + + align:start position:0% +into the manufacturing world that we've +only started to collapse from today's + + align:start position:0% +only started to collapse from today's + + + align:start position:0% +only started to collapse from today's +the special but let's go back to Joel + + align:start position:0% +the special but let's go back to Joel + + + align:start position:0% +the special but let's go back to Joel +and his three models Chris is all yours + + align:start position:0% +and his three models Chris is all yours + + + align:start position:0% +and his three models Chris is all yours +so that gets to summarize Joel is + + align:start position:0% +so that gets to summarize Joel is + + + align:start position:0% +so that gets to summarize Joel is +presenting these three models the + + align:start position:0% +presenting these three models the + + + align:start position:0% +presenting these three models the +hierarchical decomposition model where + + align:start position:0% +hierarchical decomposition model where + + + align:start position:0% +hierarchical decomposition model where +it's branched restructure the network + + align:start position:0% +it's branched restructure the network + + + align:start position:0% +it's branched restructure the network +design model and then the layered design + + align:start position:0% +design model and then the layered design + + + align:start position:0% +design model and then the layered design +model and then he basically goes on to + + align:start position:0% +model and then he basically goes on to + + + align:start position:0% +model and then he basically goes on to +outline a bunch of examples where you + + align:start position:0% +outline a bunch of examples where you + + + align:start position:0% +outline a bunch of examples where you +could present or sorry apply different + + align:start position:0% +could present or sorry apply different + + + align:start position:0% +could present or sorry apply different +methodologies into analyzing various + + align:start position:0% +methodologies into analyzing various + + + align:start position:0% +methodologies into analyzing various +systems so he goes through like + + align:start position:0% +systems so he goes through like + + + align:start position:0% +systems so he goes through like +philosophy example he goes through + + align:start position:0% +philosophy example he goes through + + + align:start position:0% +philosophy example he goes through +manufacturing even kind + + align:start position:0% +manufacturing even kind + + + align:start position:0% +manufacturing even kind +more science-based like the models the + + align:start position:0% +more science-based like the models the + + + align:start position:0% +more science-based like the models the +human mind and body and one of them I + + align:start position:0% +human mind and body and one of them I + + + align:start position:0% +human mind and body and one of them I +found particularly interesting was where + + align:start position:0% +found particularly interesting was where + + + align:start position:0% +found particularly interesting was where +he brought up culture and how the + + align:start position:0% +he brought up culture and how the + + + align:start position:0% +he brought up culture and how the +preconceptions of how engineering and + + align:start position:0% +preconceptions of how engineering and + + + align:start position:0% +preconceptions of how engineering and +manufacturing is viewed here versus + + align:start position:0% +manufacturing is viewed here versus + + + align:start position:0% +manufacturing is viewed here versus +let's say Germany or Japan has really + + align:start position:0% +let's say Germany or Japan has really + + + align:start position:0% +let's say Germany or Japan has really +impacted the way these countries have + + align:start position:0% +impacted the way these countries have + + + align:start position:0% +impacted the way these countries have +responded toward some ships + + align:start position:0% +responded toward some ships + + + align:start position:0% +responded toward some ships +manufacturing and how that industry + + align:start position:0% +manufacturing and how that industry + + + align:start position:0% +manufacturing and how that industry +develops and also have cooperation and + + align:start position:0% +develops and also have cooperation and + + + align:start position:0% +develops and also have cooperation and +japanese culture has really allowed the + + align:start position:0% +japanese culture has really allowed the + + + align:start position:0% +japanese culture has really allowed the +precipitous like rise of their industry + + align:start position:0% +precipitous like rise of their industry + + + align:start position:0% +precipitous like rise of their industry +manufacturing capabilities and how that + + align:start position:0% +manufacturing capabilities and how that + + + align:start position:0% +manufacturing capabilities and how that +shaped and kind of forced American firms + + align:start position:0% +shaped and kind of forced American firms + + + align:start position:0% +shaped and kind of forced American firms +to adopt a similar structure or + + align:start position:0% +to adopt a similar structure or + + + align:start position:0% +to adopt a similar structure or +methodology in order to compete so + + align:start position:0% +methodology in order to compete so + + + align:start position:0% +methodology in order to compete so +that's just one example of how + + align:start position:0% +that's just one example of how + + + align:start position:0% +that's just one example of how +interestingly enough a lot of the + + align:start position:0% +interestingly enough a lot of the + + + align:start position:0% +interestingly enough a lot of the +examples were not really engineering + + align:start position:0% +examples were not really engineering + + + align:start position:0% +examples were not really engineering +based even though he started from the + + align:start position:0% +based even though he started from the + + + align:start position:0% +based even though he started from the +hierarchical model which is seen very + + align:start position:0% +hierarchical model which is seen very + + + align:start position:0% +hierarchical model which is seen very +often in engineering and I thought that + + align:start position:0% +often in engineering and I thought that + + + align:start position:0% +often in engineering and I thought that +was really interesting + + align:start position:0% +was really interesting + + + align:start position:0% +was really interesting +you can definitely go into some of the + + align:start position:0% +you can definitely go into some of the + + + align:start position:0% +you can definitely go into some of the +examples more if anyone has a particular + + align:start position:0% +examples more if anyone has a particular + + + align:start position:0% +examples more if anyone has a particular +one to go into but to start off the + + align:start position:0% +one to go into but to start off the + + + align:start position:0% +one to go into but to start off the +discussion I thought this question was + + align:start position:0% +discussion I thought this question was + + + align:start position:0% +discussion I thought this question was +really interesting how does a country + + align:start position:0% +really interesting how does a country + + + align:start position:0% +really interesting how does a country +shift from a tree structure so the + + align:start position:0% +shift from a tree structure so the + + + align:start position:0% +shift from a tree structure so the +higher your hierarchy one to more + + align:start position:0% +higher your hierarchy one to more + + + align:start position:0% +higher your hierarchy one to more +layered or network structure once it's + + align:start position:0% +layered or network structure once it's + + + align:start position:0% +layered or network structure once it's +already been established so there's any + + align:start position:0% +already been established so there's any + + + align:start position:0% +already been established so there's any +thoughts don't be good + + align:start position:0% +thoughts don't be good + + + align:start position:0% +thoughts don't be good +throw them so a two class called like + + align:start position:0% +throw them so a two class called like + + + align:start position:0% +throw them so a two class called like +structural organizations and it talks + + align:start position:0% +structural organizations and it talks + + + align:start position:0% +structural organizations and it talks +about like so it's not like there's a + + align:start position:0% +about like so it's not like there's a + + + align:start position:0% +about like so it's not like there's a +right or wrong answer it's really + + align:start position:0% +right or wrong answer it's really + + + align:start position:0% +right or wrong answer it's really +recommend what you're trying to do + + align:start position:0% +recommend what you're trying to do + + + align:start position:0% +recommend what you're trying to do +so in general when it's more networked + + align:start position:0% +so in general when it's more networked + + + align:start position:0% +so in general when it's more networked +again it's one make better decisions but + + align:start position:0% +again it's one make better decisions but + + + align:start position:0% +again it's one make better decisions but +the drawback is I don't take a much + + align:start position:0% +the drawback is I don't take a much + + + align:start position:0% +the drawback is I don't take a much +longer time parallel you might not make + + align:start position:0% +longer time parallel you might not make + + + align:start position:0% +longer time parallel you might not make +great decisions but you make them very + + align:start position:0% +great decisions but you make them very + + + align:start position:0% +great decisions but you make them very +quickly and as long as people respect + + align:start position:0% +quickly and as long as people respect + + + align:start position:0% +quickly and as long as people respect +that the person who's making decision is + + align:start position:0% +that the person who's making decision is + + + align:start position:0% +that the person who's making decision is +ensured of you pretty much okay in terms + + align:start position:0% +ensured of you pretty much okay in terms + + + align:start position:0% +ensured of you pretty much okay in terms +of a comedy I think it really does + + align:start position:0% +of a comedy I think it really does + + + align:start position:0% +of a comedy I think it really does +depend it's like you know I think + + align:start position:0% +depend it's like you know I think + + + align:start position:0% +depend it's like you know I think +network structure works we're great for + + align:start position:0% +network structure works we're great for + + + align:start position:0% +network structure works we're great for +like a Facebook or like something with + + align:start position:0% +like a Facebook or like something with + + + align:start position:0% +like a Facebook or like something with +the internet base where you're really + + align:start position:0% +the internet base where you're really + + + align:start position:0% +the internet base where you're really +competing for ideas you're trying to + + align:start position:0% +competing for ideas you're trying to + + + align:start position:0% +competing for ideas you're trying to +come up with ideas things move quickly + + align:start position:0% +come up with ideas things move quickly + + + align:start position:0% +come up with ideas things move quickly +so you want to get irate quickly versus + + align:start position:0% +so you want to get irate quickly versus + + + align:start position:0% +so you want to get irate quickly versus +I think it was like manufacturing as + + align:start position:0% +I think it was like manufacturing as + + + align:start position:0% +I think it was like manufacturing as +much + + align:start position:0% + + + + align:start position:0% + +Chris did you agree with Joel's + + align:start position:0% +Chris did you agree with Joel's + + + align:start position:0% +Chris did you agree with Joel's +presentation here do these models make + + align:start position:0% +presentation here do these models make + + + align:start position:0% +presentation here do these models make +sense to you I thought it was + + align:start position:0% +sense to you I thought it was + + + align:start position:0% +sense to you I thought it was +interesting how he presented kind of + + align:start position:0% +interesting how he presented kind of + + + align:start position:0% +interesting how he presented kind of +three frameworks for looking at + + align:start position:0% +three frameworks for looking at + + + align:start position:0% +three frameworks for looking at +different firms and then went about kind + + align:start position:0% +different firms and then went about kind + + + align:start position:0% +different firms and then went about kind +of applying that model to different + + align:start position:0% +of applying that model to different + + + align:start position:0% +of applying that model to different +situations companies industries I + + align:start position:0% +situations companies industries I + + + align:start position:0% +situations companies industries I +thought that was interesting + + align:start position:0% +thought that was interesting + + + align:start position:0% +thought that was interesting +again just like some of you I had a + + align:start position:0% +again just like some of you I had a + + + align:start position:0% +again just like some of you I had a +little bit of trouble distinguishing + + align:start position:0% +little bit of trouble distinguishing + + + align:start position:0% +little bit of trouble distinguishing +between some of them as I was reading + + align:start position:0% +between some of them as I was reading + + + align:start position:0% +between some of them as I was reading +reading it so perhaps kind of going into + + align:start position:0% +reading it so perhaps kind of going into + + + align:start position:0% +reading it so perhaps kind of going into +more about defining the differences + + align:start position:0% +more about defining the differences + + + align:start position:0% +more about defining the differences +between the different models and also + + align:start position:0% +between the different models and also + + + align:start position:0% +between the different models and also +maybe even trying to generalize which + + align:start position:0% +maybe even trying to generalize which + + + align:start position:0% +maybe even trying to generalize which +model would be applicable to like what + + align:start position:0% +model would be applicable to like what + + + align:start position:0% +model would be applicable to like what +characteristics would be most amenable + + align:start position:0% +characteristics would be most amenable + + + align:start position:0% +characteristics would be most amenable +to these models that could be an + + align:start position:0% +to these models that could be an + + + align:start position:0% +to these models that could be an +interesting and additional step okay all + + align:start position:0% +interesting and additional step okay all + + + align:start position:0% +interesting and additional step okay all +right I think on that good note you will + + align:start position:0% +right I think on that good note you will + + + align:start position:0% +right I think on that good note you will +have a few minutes early \ No newline at end of file diff --git a/CKncVaiv_08.txt b/CKncVaiv_08.txt new file mode 100644 index 0000000000000000000000000000000000000000..eaeca85f81b62fad12b196f1e254086e442af509 --- /dev/null +++ b/CKncVaiv_08.txt @@ -0,0 +1,8739 @@ +align:start position:0% + +so what I'd like to do + + align:start position:0% +so what I'd like to do + + + align:start position:0% +so what I'd like to do +today is talk about an entirely + + align:start position:0% +today is talk about an entirely + + + align:start position:0% +today is talk about an entirely +different class of switching power + + align:start position:0% +different class of switching power + + + align:start position:0% +different class of switching power +converter than they've talked about + + align:start position:0% +converter than they've talked about + + + align:start position:0% +converter than they've talked about +before and um we are going + + align:start position:0% + + + + align:start position:0% + +to we are going to um look at this for + + align:start position:0% +to we are going to um look at this for + + + align:start position:0% +to we are going to um look at this for +this class and next class uh we're going + + align:start position:0% +this class and next class uh we're going + + + align:start position:0% +this class and next class uh we're going +to talk about switched capacitor + + align:start position:0% + + + + align:start position:0% + +converters and that's uh principles of + + align:start position:0% +converters and that's uh principles of + + + align:start position:0% +converters and that's uh principles of +Power + + align:start position:0% +Power + + + align:start position:0% +Power +Electronics chapter + + align:start position:0% + + + + align:start position:0% + +six + + align:start position:0% + + + + align:start position:0% + +okay most + + align:start position:0% +okay most + + + align:start position:0% +okay most +converters introduce magnetics in them + + align:start position:0% +converters introduce magnetics in them + + + align:start position:0% +converters introduce magnetics in them +right they have some magnetic component + + align:start position:0% +right they have some magnetic component + + + align:start position:0% +right they have some magnetic component +in why do you want why do you want say + + align:start position:0% +in why do you want why do you want say + + + align:start position:0% +in why do you want why do you want say +an inductor or an inductive energy + + align:start position:0% +an inductor or an inductive energy + + + align:start position:0% +an inductor or an inductive energy +storage El in your converter that's + + align:start position:0% +storage El in your converter that's + + + align:start position:0% +storage El in your converter that's +because if I put a voltage difference + + align:start position:0% +because if I put a voltage difference + + + align:start position:0% +because if I put a voltage difference +across it from say an input voltage or + + align:start position:0% +across it from say an input voltage or + + + align:start position:0% +across it from say an input voltage or +an output voltage or two voltages the + + align:start position:0% +an output voltage or two voltages the + + + align:start position:0% +an output voltage or two voltages the +inductor can instantaneously take that + + align:start position:0% +inductor can instantaneously take that + + + align:start position:0% +inductor can instantaneously take that +energy difference absorb the voltage + + align:start position:0% +energy difference absorb the voltage + + + align:start position:0% +energy difference absorb the voltage +difference absorb energy that then we + + align:start position:0% +difference absorb energy that then we + + + align:start position:0% +difference absorb energy that then we +can recover later right and that's sort + + align:start position:0% +can recover later right and that's sort + + + align:start position:0% +can recover later right and that's sort +of the principle we operate on and + + align:start position:0% +of the principle we operate on and + + + align:start position:0% +of the principle we operate on and +that's why almost all these converters + + align:start position:0% +that's why almost all these converters + + + align:start position:0% +that's why almost all these converters +use magnetics or something that acts + + align:start position:0% +use magnetics or something that acts + + + align:start position:0% +use magnetics or something that acts +like a magnetic component + + align:start position:0% +like a magnetic component + + + align:start position:0% +like a magnetic component +on the other hand sometimes you can get + + align:start position:0% +on the other hand sometimes you can get + + + align:start position:0% +on the other hand sometimes you can get +away + + align:start position:0% +away + + + align:start position:0% +away +without any magnetic components without + + align:start position:0% +without any magnetic components without + + + align:start position:0% +without any magnetic components without +any inductors in your circuit and why + + align:start position:0% +any inductors in your circuit and why + + + align:start position:0% +any inductors in your circuit and why +might you want to do that well because + + align:start position:0% +might you want to do that well because + + + align:start position:0% +might you want to do that well because +if you look at things that are on you + + align:start position:0% +if you look at things that are on you + + + align:start position:0% +if you look at things that are on you +know the scale of my thumb or something + + align:start position:0% +know the scale of my thumb or something + + + align:start position:0% +know the scale of my thumb or something +you know some some small element the + + align:start position:0% +you know some some small element the + + + align:start position:0% +you know some some small element the +energy density you can achieve with a + + align:start position:0% +energy density you can achieve with a + + + align:start position:0% +energy density you can achieve with a +capacitor is orders of magnitude higher + + align:start position:0% +capacitor is orders of magnitude higher + + + align:start position:0% +capacitor is orders of magnitude higher +than the energy density you can achieve + + align:start position:0% +than the energy density you can achieve + + + align:start position:0% +than the energy density you can achieve +with a a magnetic component at similar + + align:start position:0% +with a a magnetic component at similar + + + align:start position:0% +with a a magnetic component at similar +uh efficiencies and energy storage + + align:start position:0% +uh efficiencies and energy storage + + + align:start position:0% +uh efficiencies and energy storage +levels right so you know capacitors are + + align:start position:0% +levels right so you know capacitors are + + + align:start position:0% +levels right so you know capacitors are +just extremely highly energy dense so if + + align:start position:0% +just extremely highly energy dense so if + + + align:start position:0% +just extremely highly energy dense so if +I happen to have an application where I + + align:start position:0% +I happen to have an application where I + + + align:start position:0% +I happen to have an application where I +can get away with only capacitive energy + + align:start position:0% +can get away with only capacitive energy + + + align:start position:0% +can get away with only capacitive energy +storage you can build a much smaller + + align:start position:0% +storage you can build a much smaller + + + align:start position:0% +storage you can build a much smaller +more efficient converter okay but that + + align:start position:0% +more efficient converter okay but that + + + align:start position:0% +more efficient converter okay but that +application space is limited and we're + + align:start position:0% +application space is limited and we're + + + align:start position:0% +application space is limited and we're +going to get into why so switch + + align:start position:0% +going to get into why so switch + + + align:start position:0% +going to get into why so switch +capacitor converters are essentially you + + align:start position:0% +capacitor converters are essentially you + + + align:start position:0% +capacitor converters are essentially you +know to come back to their definition + + align:start position:0% +know to come back to their definition + + + align:start position:0% +know to come back to their definition +are essentially converters where I + + align:start position:0% +are essentially converters where I + + + align:start position:0% +are essentially converters where I +process all my energy using capacitors + + align:start position:0% +process all my energy using capacitors + + + align:start position:0% +process all my energy using capacitors +and so I have capacitors and switches to + + align:start position:0% +and so I have capacitors and switches to + + + align:start position:0% +and so I have capacitors and switches to +do the energy throughput I brought a + + align:start position:0% +do the energy throughput I brought a + + + align:start position:0% +do the energy throughput I brought a +couple of examples with these These are + + align:start position:0% +couple of examples with these These are + + + align:start position:0% +couple of examples with these These are +both uh kind of prototype designs this + + align:start position:0% +both uh kind of prototype designs this + + + align:start position:0% +both uh kind of prototype designs this +one is a very small power low power one + + align:start position:0% +one is a very small power low power one + + + align:start position:0% +one is a very small power low power one +you'll see much of it on the front and + + align:start position:0% +you'll see much of it on the front and + + + align:start position:0% +you'll see much of it on the front and +it has some energy storage capacitors on + + align:start position:0% +it has some energy storage capacitors on + + + align:start position:0% +it has some energy storage capacitors on +the back this is another overall circuit + + align:start position:0% +the back this is another overall circuit + + + align:start position:0% +the back this is another overall circuit +and this part over here is a switch + + align:start position:0% +and this part over here is a switch + + + align:start position:0% +and this part over here is a switch +capacitor converter of a certain type so + + align:start position:0% +capacitor converter of a certain type so + + + align:start position:0% +capacitor converter of a certain type so +just to kind of illustrate what we're + + align:start position:0% +just to kind of illustrate what we're + + + align:start position:0% +just to kind of illustrate what we're +talking about you can take a look at + + align:start position:0% +talking about you can take a look at + + + align:start position:0% +talking about you can take a look at +these okay and so let's in order to sort + + align:start position:0% +these okay and so let's in order to sort + + + align:start position:0% +these okay and so let's in order to sort +of illustrate their strengths and + + align:start position:0% +of illustrate their strengths and + + + align:start position:0% +of illustrate their strengths and +weaknesses let's look at the simplest + + align:start position:0% +weaknesses let's look at the simplest + + + align:start position:0% +weaknesses let's look at the simplest +switch capacitor converter I can think + + align:start position:0% +switch capacitor converter I can think + + + align:start position:0% +switch capacitor converter I can think +of and this is sometimes known as a two + + align:start position:0% +of and this is sometimes known as a two + + + align:start position:0% +of and this is sometimes known as a two +to1 step down converter although uh + + align:start position:0% +to1 step down converter although uh + + + align:start position:0% +to1 step down converter although uh +we'll come back to why people call it + + align:start position:0% +we'll come back to why people call it + + + align:start position:0% +we'll come back to why people call it +that but but what its tradeoffs are so + + align:start position:0% +that but but what its tradeoffs are so + + + align:start position:0% +that but but what its tradeoffs are so +here's the idea I had some input + + align:start position:0% + + + + align:start position:0% + +voltage okay from which I'm going to + + align:start position:0% +voltage okay from which I'm going to + + + align:start position:0% +voltage okay from which I'm going to +draw a power and I'm going to have a + + align:start position:0% +draw a power and I'm going to have a + + + align:start position:0% +draw a power and I'm going to have a +capacitor here and this capacitor is my + + align:start position:0% +capacitor here and this capacitor is my + + + align:start position:0% +capacitor here and this capacitor is my +energy transfer transfer capacitor so + + align:start position:0% +energy transfer transfer capacitor so + + + align:start position:0% +energy transfer transfer capacitor so +here c i and VC okay so in this example + + align:start position:0% +here c i and VC okay so in this example + + + align:start position:0% +here c i and VC okay so in this example +I'm going to do this is this element is + + align:start position:0% +I'm going to do this is this element is + + + align:start position:0% +I'm going to do this is this element is +where I'm storing the + + align:start position:0% +where I'm storing the + + + align:start position:0% +where I'm storing the +energy in the intermediate form to do + + align:start position:0% +energy in the intermediate form to do + + + align:start position:0% +energy in the intermediate form to do +this energy procing okay so I'll have uh + + align:start position:0% +this energy procing okay so I'll have uh + + + align:start position:0% +this energy procing okay so I'll have uh +switches okay and then I will have + + align:start position:0% +switches okay and then I will have + + + align:start position:0% +switches okay and then I will have +delivered some output I'm going to call + + align:start position:0% +delivered some output I'm going to call + + + align:start position:0% +delivered some output I'm going to call +this c big this is like my filter + + align:start position:0% +this c big this is like my filter + + + align:start position:0% +this c big this is like my filter +capacitor okay and then you know here I + + align:start position:0% +capacitor okay and then you know here I + + + align:start position:0% +capacitor okay and then you know here I +have some output current this is the + + align:start position:0% +have some output current this is the + + + align:start position:0% +have some output current this is the +load + + align:start position:0% +load + + + align:start position:0% +load +current okay and this is V + + align:start position:0% +current okay and this is V + + + align:start position:0% +current okay and this is V +out okay so + + align:start position:0% +out okay so + + + align:start position:0% +out okay so +I'm going to have these two capacitor + + align:start position:0% +I'm going to have these two capacitor + + + align:start position:0% +I'm going to have these two capacitor +these two switches and these are phase + + align:start position:0% +these two switches and these are phase + + + align:start position:0% +these two switches and these are phase +one switches okay then I'm going to put + + align:start position:0% +one switches okay then I'm going to put + + + align:start position:0% +one switches okay then I'm going to put +two more switches in I'm going to call + + align:start position:0% +two more switches in I'm going to call + + + align:start position:0% +two more switches in I'm going to call +these phase two switches okay so here's + + align:start position:0% +these phase two switches okay so here's + + + align:start position:0% +these phase two switches okay so here's +one one and 2 + + align:start position:0% +one one and 2 + + + align:start position:0% +one one and 2 +two okay and the idea here is that we're + + align:start position:0% +two okay and the idea here is that we're + + + align:start position:0% +two okay and the idea here is that we're +going to alternately take the + + align:start position:0% +going to alternately take the + + + align:start position:0% +going to alternately take the +switches that are labeled one and close + + align:start position:0% +switches that are labeled one and close + + + align:start position:0% +switches that are labeled one and close +them together and then at some other + + align:start position:0% +them together and then at some other + + + align:start position:0% +them together and then at some other +point in the we're going to open those + + align:start position:0% +point in the we're going to open those + + + align:start position:0% +point in the we're going to open those +switches and close the switches that are + + align:start position:0% +switches and close the switches that are + + + align:start position:0% +switches and close the switches that are +labeled two together okay what you're + + align:start position:0% +labeled two together okay what you're + + + align:start position:0% +labeled two together okay what you're +going to see one of the characteristics + + align:start position:0% +going to see one of the characteristics + + + align:start position:0% +going to see one of the characteristics +of switch capacitor converters they tend + + align:start position:0% +of switch capacitor converters they tend + + + align:start position:0% +of switch capacitor converters they tend +to have a lot of switches and in fact if + + align:start position:0% +to have a lot of switches and in fact if + + + align:start position:0% +to have a lot of switches and in fact if +you want High conversion ratios they + + align:start position:0% +you want High conversion ratios they + + + align:start position:0% +you want High conversion ratios they +have lots of switches and lots of + + align:start position:0% +have lots of switches and lots of + + + align:start position:0% +have lots of switches and lots of +capacitors we'll talk about that a + + align:start position:0% +capacitors we'll talk about that a + + + align:start position:0% +capacitors we'll talk about that a +little bit more so this is you know this + + align:start position:0% +little bit more so this is you know this + + + align:start position:0% +little bit more so this is you know this +beast in the Box here if you will I + + align:start position:0% +beast in the Box here if you will I + + + align:start position:0% +beast in the Box here if you will I +don't know you can include the output + + align:start position:0% +don't know you can include the output + + + align:start position:0% +don't know you can include the output +capacitor I suppose is a the simplest + + align:start position:0% +capacitor I suppose is a the simplest + + + align:start position:0% +capacitor I suppose is a the simplest +switch capacitor converter I can think + + align:start position:0% +switch capacitor converter I can think + + + align:start position:0% +switch capacitor converter I can think +of + + align:start position:0% +of + + + align:start position:0% +of +to analyze it let me just simplify it + + align:start position:0% +to analyze it let me just simplify it + + + align:start position:0% +to analyze it let me just simplify it +I'm going to think about this is a + + align:start position:0% +I'm going to think about this is a + + + align:start position:0% +I'm going to think about this is a +really big output capacitor so for the + + align:start position:0% +really big output capacitor so for the + + + align:start position:0% +really big output capacitor so for the +moment let me just replace him with a + + align:start position:0% +moment let me just replace him with a + + + align:start position:0% +moment let me just replace him with a +voltage source V out okay so for my + + align:start position:0% +voltage source V out okay so for my + + + align:start position:0% +voltage source V out okay so for my +analysis I'm going to uh simplify this + + align:start position:0% +analysis I'm going to uh simplify this + + + align:start position:0% +analysis I'm going to uh simplify this +just a little and I'll say we have um an + + align:start position:0% +just a little and I'll say we have um an + + + align:start position:0% +just a little and I'll say we have um an +input voltage + + align:start position:0% +input voltage + + + align:start position:0% +input voltage +VN + + align:start position:0% + + + + align:start position:0% + +okay here's my + + align:start position:0% +okay here's my + + + align:start position:0% +okay here's my +capacitor VC + + align:start position:0% +capacitor VC + + + align:start position:0% +capacitor VC +i + + align:start position:0% +i + + + align:start position:0% +i +c my two switches I'm just going to + + align:start position:0% +c my two switches I'm just going to + + + align:start position:0% +c my two switches I'm just going to +replace this with an output voltage V + + align:start position:0% +replace this with an output voltage V + + + align:start position:0% +replace this with an output voltage V +out okay and then I'm going to have this + + align:start position:0% +out okay and then I'm going to have this + + + align:start position:0% +out okay and then I'm going to have this +is switch one switch + + align:start position:0% +is switch one switch + + + align:start position:0% +is switch one switch +one switch + + align:start position:0% + + + + align:start position:0% + +two and switch + + align:start position:0% +two and switch + + + align:start position:0% +two and switch +two okay and this is the circuit we're + + align:start position:0% +two okay and this is the circuit we're + + + align:start position:0% +two okay and this is the circuit we're +going to + + align:start position:0% +going to + + + align:start position:0% +going to +analyze Okay so State + + align:start position:0% + + + + align:start position:0% + +one right I basically have these two + + align:start position:0% +one right I basically have these two + + + align:start position:0% +one right I basically have these two +switches closed so in state one the + + align:start position:0% +switches closed so in state one the + + + align:start position:0% +switches closed so in state one the +converter looks like this + + align:start position:0% +converter looks like this + + + align:start position:0% +converter looks like this +BN right a first switch is going to be + + align:start position:0% +BN right a first switch is going to be + + + align:start position:0% +BN right a first switch is going to be +on I'll call that R switch right then + + align:start position:0% +on I'll call that R switch right then + + + align:start position:0% +on I'll call that R switch right then +I'm going to have my + + align:start position:0% + + + + align:start position:0% + +capacitor and then I'm going to have my + + align:start position:0% +capacitor and then I'm going to have my + + + align:start position:0% +capacitor and then I'm going to have my +second s + + align:start position:0% +second s + + + align:start position:0% +second s +s and then that's going to go to the + + align:start position:0% + + + + align:start position:0% + +output okay and in my second state state + + align:start position:0% + + + + align:start position:0% + +two the input's now going to be + + align:start position:0% + + + + align:start position:0% + +disconnected okay but I am going to + + align:start position:0% +disconnected okay but I am going to + + + align:start position:0% +disconnected okay but I am going to +connect my capacitor + + align:start position:0% + + + + align:start position:0% + +through a resistor to the + + align:start position:0% + + + + align:start position:0% + +output like + + align:start position:0% + + + + align:start position:0% + +this okay any questions about the two + + align:start position:0% +this okay any questions about the two + + + align:start position:0% +this okay any questions about the two +switch + + align:start position:0% +switch + + + align:start position:0% +switch +configurations let's just for Simplicity + + align:start position:0% +configurations let's just for Simplicity + + + align:start position:0% +configurations let's just for Simplicity +assume I'm going to flop back and fourth + + align:start position:0% +assume I'm going to flop back and fourth + + + align:start position:0% +assume I'm going to flop back and fourth +at 50% duty cycle between these two + + align:start position:0% +at 50% duty cycle between these two + + + align:start position:0% +at 50% duty cycle between these two +states although we'll see in some cases + + align:start position:0% +states although we'll see in some cases + + + align:start position:0% +states although we'll see in some cases +the duty cycle matters and some cases it + + align:start position:0% +the duty cycle matters and some cases it + + + align:start position:0% +the duty cycle matters and some cases it +doesn't all right any + + align:start position:0% +doesn't all right any + + + align:start position:0% +doesn't all right any +questions yeah so in this case we can't + + align:start position:0% +questions yeah so in this case we can't + + + align:start position:0% +questions yeah so in this case we can't +deal with IDE switches we have to think + + align:start position:0% +deal with IDE switches we have to think + + + align:start position:0% +deal with IDE switches we have to think +about + + align:start position:0% +about + + + align:start position:0% +about +the + + align:start position:0% +the + + + align:start position:0% +the +uh it it helps to think about the + + align:start position:0% +uh it it helps to think about the + + + align:start position:0% +uh it it helps to think about the +parasitic resistance um because we were + + align:start position:0% +parasitic resistance um because we were + + + align:start position:0% +parasitic resistance um because we were +going to worry about how much energy we + + align:start position:0% +going to worry about how much energy we + + + align:start position:0% +going to worry about how much energy we +dissipate in the switches but if I let + + align:start position:0% +dissipate in the switches but if I let + + + align:start position:0% +dissipate in the switches but if I let +the switch resistances go to zero the + + align:start position:0% +the switch resistances go to zero the + + + align:start position:0% +the switch resistances go to zero the +answer doesn't change + + align:start position:0% +answer doesn't change + + + align:start position:0% +answer doesn't change +actually um so yeah we'll come back to + + align:start position:0% +actually um so yeah we'll come back to + + + align:start position:0% +actually um so yeah we'll come back to +that that + + align:start position:0% +that that + + + align:start position:0% +that that +point okay okay so let's think about + + align:start position:0% +point okay okay so let's think about + + + align:start position:0% +point okay okay so let's think about +this now in order to analyze this what + + align:start position:0% +this now in order to analyze this what + + + align:start position:0% +this now in order to analyze this what +I'd like to do is focus on uh here I + + align:start position:0% +I'd like to do is focus on uh here I + + + align:start position:0% +I'd like to do is focus on uh here I +have + + align:start position:0% + + + + align:start position:0% + +VN here's + + align:start position:0% +VN here's + + + align:start position:0% +VN here's +VN let me talk about the current I in + + align:start position:0% +VN let me talk about the current I in + + + align:start position:0% +VN let me talk about the current I in +going into + + align:start position:0% +going into + + + align:start position:0% +going into +VN okay and here I have V + + align:start position:0% +VN okay and here I have V + + + align:start position:0% +VN okay and here I have V +out and here's I + + align:start position:0% +out and here's I + + + align:start position:0% +out and here's I +out and then I have VC + + align:start position:0% +out and then I have VC + + + align:start position:0% +out and then I have VC +and + + align:start position:0% +and + + + align:start position:0% +and +I I guess I should have drawn this on + + align:start position:0% +I I guess I should have drawn this on + + + align:start position:0% +I I guess I should have drawn this on +the main circuit right so this is uh + + align:start position:0% +the main circuit right so this is uh + + + align:start position:0% +the main circuit right so this is uh +VN I + + align:start position:0% + + + + align:start position:0% + +in V + + align:start position:0% +in V + + + align:start position:0% +in V +out I + + align:start position:0% +out I + + + align:start position:0% +out I +out and + + align:start position:0% + + + + align:start position:0% + +vciic okay and what I would like to + + align:start position:0% +vciic okay and what I would like to + + + align:start position:0% +vciic okay and what I would like to +do is um track + + align:start position:0% +do is um track + + + align:start position:0% +do is um track +the charge flowing through this + + align:start position:0% +the charge flowing through this + + + align:start position:0% +the charge flowing through this +converter okay which is going to let me + + align:start position:0% +converter okay which is going to let me + + + align:start position:0% +converter okay which is going to let me +sort of understand what its conversion + + align:start position:0% +sort of understand what its conversion + + + align:start position:0% +sort of understand what its conversion +ratio is and analyzing any switch + + align:start position:0% +ratio is and analyzing any switch + + + align:start position:0% +ratio is and analyzing any switch +capacitor converter more or less comes + + align:start position:0% +capacitor converter more or less comes + + + align:start position:0% +capacitor converter more or less comes +down to the process I'm following there + + align:start position:0% +down to the process I'm following there + + + align:start position:0% +down to the process I'm following there +are ways that you we can sort of + + align:start position:0% +are ways that you we can sort of + + + align:start position:0% +are ways that you we can sort of +organize it to do the general case okay + + align:start position:0% +organize it to do the general case okay + + + align:start position:0% +organize it to do the general case okay +but let's just think about this case and + + align:start position:0% +but let's just think about this case and + + + align:start position:0% +but let's just think about this case and +what I'm going to think about is um + + align:start position:0% +what I'm going to think about is um + + + align:start position:0% +what I'm going to think about is um +let's suppose that when I close the + + align:start position:0% +let's suppose that when I close the + + + align:start position:0% +let's suppose that when I close the +switches and I have some switch + + align:start position:0% +switches and I have some switch + + + align:start position:0% +switches and I have some switch +resistances the values don't matter but + + align:start position:0% +resistances the values don't matter but + + + align:start position:0% +resistances the values don't matter but +let's ask what does the final voltage of + + align:start position:0% +let's ask what does the final voltage of + + + align:start position:0% +let's ask what does the final voltage of +the + + align:start position:0% +the + + + align:start position:0% +the +capacitor uh end up at right so at the + + align:start position:0% +capacitor uh end up at right so at the + + + align:start position:0% +capacitor uh end up at right so at the +end of State one what I'm going to + + align:start position:0% +end of State one what I'm going to + + + align:start position:0% +end of State one what I'm going to +assume for my first analysis and this is + + align:start position:0% +assume for my first analysis and this is + + + align:start position:0% +assume for my first analysis and this is +what's known as the slow switching limit + + align:start position:0% +what's known as the slow switching limit + + + align:start position:0% +what's known as the slow switching limit +is that you know I I close my switches + + align:start position:0% +is that you know I I close my switches + + + align:start position:0% +is that you know I I close my switches +and this capacitor charges to some final + + align:start position:0% +and this capacitor charges to some final + + + align:start position:0% +and this capacitor charges to some final +value and then stops + + align:start position:0% +value and then stops + + + align:start position:0% +value and then stops +charging okay so what would be the final + + align:start position:0% +charging okay so what would be the final + + + align:start position:0% +charging okay so what would be the final +value of the capacitor in this state one + + align:start position:0% +value of the capacitor in this state one + + + align:start position:0% +value of the capacitor in this state one +so + + align:start position:0% + + + + align:start position:0% + +VC um at the in state one at the + + align:start position:0% +VC um at the in state one at the + + + align:start position:0% +VC um at the in state one at the +N what what voltage would VC charge + + align:start position:0% + + + + align:start position:0% + +to has to be VN minus V + + align:start position:0% + + + + align:start position:0% + +out and in state + + align:start position:0% +out and in state + + + align:start position:0% +out and in state +two at the + + align:start position:0% +two at the + + + align:start position:0% +two at the +end correspond L VC has to go to V + + align:start position:0% +end correspond L VC has to go to V + + + align:start position:0% +end correspond L VC has to go to V +out okay so the idea is if I looked at + + align:start position:0% +out okay so the idea is if I looked at + + + align:start position:0% +out okay so the idea is if I looked at +what VC was going to + + align:start position:0% +what VC was going to + + + align:start position:0% +what VC was going to +do it's going to start off when I enter + + align:start position:0% +do it's going to start off when I enter + + + align:start position:0% +do it's going to start off when I enter +State one or if if they into state two + + align:start position:0% +State one or if if they into state two + + + align:start position:0% +State one or if if they into state two +I'm going to be at V out I'm going to + + align:start position:0% +I'm going to be at V out I'm going to + + + align:start position:0% +I'm going to be at V out I'm going to +flip my switches and then VC is going to + + align:start position:0% +flip my switches and then VC is going to + + + align:start position:0% +flip my switches and then VC is going to +charge to Vin minus V out and I'm going + + align:start position:0% +charge to Vin minus V out and I'm going + + + align:start position:0% +charge to Vin minus V out and I'm going +to switch my switches then VC is going + + align:start position:0% +to switch my switches then VC is going + + + align:start position:0% +to switch my switches then VC is going +to discharge in this case back to V out + + align:start position:0% +to discharge in this case back to V out + + + align:start position:0% +to discharge in this case back to V out +and it's going to repeat + + align:start position:0% +and it's going to repeat + + + align:start position:0% +and it's going to repeat +that make sense everybody so I'm sort of + + align:start position:0% +that make sense everybody so I'm sort of + + + align:start position:0% +that make sense everybody so I'm sort of +assuming and this is the slow switching + + align:start position:0% + + + + align:start position:0% + +limit that what my capacitor voltage is + + align:start position:0% +limit that what my capacitor voltage is + + + align:start position:0% +limit that what my capacitor voltage is +going to do versus time you know if this + + align:start position:0% +going to do versus time you know if this + + + align:start position:0% +going to do versus time you know if this +is sort of State + + align:start position:0% + + + + align:start position:0% + +one and this is sort of state two I'm + + align:start position:0% +one and this is sort of state two I'm + + + align:start position:0% +one and this is sort of state two I'm +going to have I'm going to basically my + + align:start position:0% +going to have I'm going to basically my + + + align:start position:0% +going to have I'm going to basically my +capacitor is going to charge from V + + align:start position:0% +capacitor is going to charge from V + + + align:start position:0% +capacitor is going to charge from V +out up to to V Inus V + + align:start position:0% +out up to to V Inus V + + + align:start position:0% +out up to to V Inus V +out and then it's going to charge from + + align:start position:0% +out and then it's going to charge from + + + align:start position:0% +out and then it's going to charge from +vnus V out down to V out and it's going + + align:start position:0% +vnus V out down to V out and it's going + + + align:start position:0% +vnus V out down to V out and it's going +to do something like this with some RC + + align:start position:0% +to do something like this with some RC + + + align:start position:0% +to do something like this with some RC +time charge constant and so I'm just + + align:start position:0% +time charge constant and so I'm just + + + align:start position:0% +time charge constant and so I'm just +assuming so this is going to at the end + + align:start position:0% +assuming so this is going to at the end + + + align:start position:0% +assuming so this is going to at the end +of State one it's going to V in minus V + + align:start position:0% + + + + align:start position:0% + +out and it's and it's then in the next + + align:start position:0% +out and it's and it's then in the next + + + align:start position:0% +out and it's and it's then in the next +state in state two is going to charge to + + align:start position:0% +state in state two is going to charge to + + + align:start position:0% +state in state two is going to charge to +V + + align:start position:0% +V + + + align:start position:0% +V +out okay so my only assumption is I'm + + align:start position:0% +out okay so my only assumption is I'm + + + align:start position:0% +out okay so my only assumption is I'm +going to sort of each cycle I'm going to + + align:start position:0% +going to sort of each cycle I'm going to + + + align:start position:0% +going to sort of each cycle I'm going to +charge up I'm going to charge down and + + align:start position:0% +charge up I'm going to charge down and + + + align:start position:0% +charge up I'm going to charge down and +I'm going to sort of finish the charging + + align:start position:0% +I'm going to sort of finish the charging + + + align:start position:0% +I'm going to sort of finish the charging +I'm going to let this RC time constant + + align:start position:0% +I'm going to let this RC time constant + + + align:start position:0% +I'm going to let this RC time constant +sort of go to where he's fully + + align:start position:0% +sort of go to where he's fully + + + align:start position:0% +sort of go to where he's fully +charged okay so let's think about how + + align:start position:0% +charged okay so let's think about how + + + align:start position:0% +charged okay so let's think about how +much charge I transfer in each component + + align:start position:0% +much charge I transfer in each component + + + align:start position:0% +much charge I transfer in each component +okay in state + + align:start position:0% + + + + align:start position:0% + +one right what do I have Delta + + align:start position:0% +one right what do I have Delta + + + align:start position:0% +one right what do I have Delta +QC in State One + + align:start position:0% +QC in State One + + + align:start position:0% +QC in State One +the amount of charge that gets put onto + + align:start position:0% +the amount of charge that gets put onto + + + align:start position:0% +the amount of charge that gets put onto +the capacitor in state one well what's + + align:start position:0% +the capacitor in state one well what's + + + align:start position:0% +the capacitor in state one well what's +that going to be that's going to be + + align:start position:0% +that going to be that's going to be + + + align:start position:0% +that going to be that's going to be +equal to Delta Q is C Delta + + align:start position:0% + + + + align:start position:0% + +V right which is going to be c times the + + align:start position:0% +V right which is going to be c times the + + + align:start position:0% +V right which is going to be c times the +change in voltage across state one he's + + align:start position:0% +change in voltage across state one he's + + + align:start position:0% +change in voltage across state one he's +starting at V out and he's going up to + + align:start position:0% +starting at V out and he's going up to + + + align:start position:0% +starting at V out and he's going up to +VN minus V out so it's going to be vnus + + align:start position:0% +VN minus V out so it's going to be vnus + + + align:start position:0% +VN minus V out so it's going to be vnus +V out minus V out is going to be C * + + align:start position:0% +V out minus V out is going to be C * + + + align:start position:0% +V out minus V out is going to be C * +vnus 2v + + align:start position:0% +vnus 2v + + + align:start position:0% +vnus 2v +out okay so that that's how much charge + + align:start position:0% +out okay so that that's how much charge + + + align:start position:0% +out okay so that that's how much charge +gets put on + + align:start position:0% +gets put on + + + align:start position:0% +gets put on +to uh this capacitor during State one in + + align:start position:0% +to uh this capacitor during State one in + + + align:start position:0% +to uh this capacitor during State one in +periodic steady + + align:start position:0% +periodic steady + + + align:start position:0% +periodic steady +state any questions about that because + + align:start position:0% +state any questions about that because + + + align:start position:0% +state any questions about that because +the rest of the analysis proceeds just + + align:start position:0% +the rest of the analysis proceeds just + + + align:start position:0% +the rest of the analysis proceeds just +like this so want to make sure people + + align:start position:0% +like this so want to make sure people + + + align:start position:0% +like this so want to make sure people +get what I'm + + align:start position:0% + + + + align:start position:0% + +calculating in PSS I charge and + + align:start position:0% +calculating in PSS I charge and + + + align:start position:0% +calculating in PSS I charge and +discharge between two points and I'm + + align:start position:0% +discharge between two points and I'm + + + align:start position:0% +discharge between two points and I'm +just saying how much charge went under + + align:start position:0% +just saying how much charge went under + + + align:start position:0% +just saying how much charge went under +the capacitor and State one and that's + + align:start position:0% +the capacitor and State one and that's + + + align:start position:0% +the capacitor and State one and that's +it okay well how much + + align:start position:0% + + + + align:start position:0% + +charge went into the input in state + + align:start position:0% +charge went into the input in state + + + align:start position:0% +charge went into the input in state +one okay well the way I've defined it + + align:start position:0% +one okay well the way I've defined it + + + align:start position:0% +one okay well the way I've defined it +here the input and and I've defined it + + align:start position:0% +here the input and and I've defined it + + + align:start position:0% +here the input and and I've defined it +here because the general analyses tend + + align:start position:0% +here because the general analyses tend + + + align:start position:0% +here because the general analyses tend +to do it this way is exact the current + + align:start position:0% +to do it this way is exact the current + + + align:start position:0% +to do it this way is exact the current +going in the capacitor is exactly the + + align:start position:0% +going in the capacitor is exactly the + + + align:start position:0% +going in the capacitor is exactly the +opposite of the current going into the + + align:start position:0% +opposite of the current going into the + + + align:start position:0% +opposite of the current going into the +input in state one right so the current + + align:start position:0% +input in state one right so the current + + + align:start position:0% +input in state one right so the current +the charge into the input just has to be + + align:start position:0% +the charge into the input just has to be + + + align:start position:0% +the charge into the input just has to be +the opposite this this going to be minus + + align:start position:0% +the opposite this this going to be minus + + + align:start position:0% +the opposite this this going to be minus +c v in minus 2v + + align:start position:0% +c v in minus 2v + + + align:start position:0% +c v in minus 2v +out okay and likewise the charge that + + align:start position:0% +out okay and likewise the charge that + + + align:start position:0% +out okay and likewise the charge that +got transferred into the output during + + align:start position:0% +got transferred into the output during + + + align:start position:0% +got transferred into the output during +State one is exactly equal to the charge + + align:start position:0% +State one is exactly equal to the charge + + + align:start position:0% +State one is exactly equal to the charge +in the Capac they transferred onto the + + align:start position:0% +in the Capac they transferred onto the + + + align:start position:0% +in the Capac they transferred onto the +capacitor and I get Delta Q out in state + + align:start position:0% +capacitor and I get Delta Q out in state + + + align:start position:0% +capacitor and I get Delta Q out in state +one is equal to C VN minus 2v + + align:start position:0% + + + + align:start position:0% + +out does that make sense everybody + + align:start position:0% +out does that make sense everybody + + + align:start position:0% +out does that make sense everybody +any + + align:start position:0% + + + + align:start position:0% + +questions let's think about state + + align:start position:0% + + + + align:start position:0% + +two okay Delta QC how much + + align:start position:0% +two okay Delta QC how much + + + align:start position:0% +two okay Delta QC how much +charge goes on the capacitor in state 2 + + align:start position:0% +charge goes on the capacitor in state 2 + + + align:start position:0% +charge goes on the capacitor in state 2 +is equal to C Delta V well in state 2 I + + align:start position:0% +is equal to C Delta V well in state 2 I + + + align:start position:0% +is equal to C Delta V well in state 2 I +started at V in minus V out and I ended + + align:start position:0% +started at V in minus V out and I ended + + + align:start position:0% +started at V in minus V out and I ended +V out so it's going to be V in minus V + + align:start position:0% +V out so it's going to be V in minus V + + + align:start position:0% +V out so it's going to be V in minus V +out minus V out + + align:start position:0% +out minus V out + + + align:start position:0% +out minus V out +is what I'm going to get right but + + align:start position:0% +is what I'm going to get right but + + + align:start position:0% +is what I'm going to get right but +um keep in mind + + align:start position:0% +um keep in mind + + + align:start position:0% +um keep in mind +that I could write this that this + + align:start position:0% +that I could write this that this + + + align:start position:0% +that I could write this that this +uh this is the charge is going to he's + + align:start position:0% +uh this is the charge is going to he's + + + align:start position:0% +uh this is the charge is going to he's +going to end up at V + + align:start position:0% +going to end up at V + + + align:start position:0% +going to end up at V +out minus VN minus V out so it's V out + + align:start position:0% +out minus VN minus V out so it's V out + + + align:start position:0% +out minus VN minus V out so it's V out +minus VN minus V out it's 2v out minus + + align:start position:0% +minus VN minus V out it's 2v out minus + + + align:start position:0% +minus VN minus V out it's 2v out minus +VN * C okay but I could write that as + + align:start position:0% +VN * C okay but I could write that as + + + align:start position:0% +VN * C okay but I could write that as +minus C * V in - 2v + + align:start position:0% +minus C * V in - 2v + + + align:start position:0% +minus C * V in - 2v +out okay and the reason I'm going to + + align:start position:0% +out okay and the reason I'm going to + + + align:start position:0% +out okay and the reason I'm going to +write first of all does everybody get + + align:start position:0% +write first of all does everybody get + + + align:start position:0% +write first of all does everybody get +what I just did all I did was I just + + align:start position:0% +what I just did all I did was I just + + + align:start position:0% +what I just did all I did was I just +expressed it as a with a minus sign out + + align:start position:0% +expressed it as a with a minus sign out + + + align:start position:0% +expressed it as a with a minus sign out +here I pulled the minus sign out here + + align:start position:0% +here I pulled the minus sign out here + + + align:start position:0% +here I pulled the minus sign out here +why did I pull the minus sign out here + + align:start position:0% +why did I pull the minus sign out here + + + align:start position:0% +why did I pull the minus sign out here +because I want to + + align:start position:0% +because I want to + + + align:start position:0% +because I want to +emphasize um that this is going to be a + + align:start position:0% +emphasize um that this is going to be a + + + align:start position:0% +emphasize um that this is going to be a +negative net charge or another way I + + align:start position:0% +negative net charge or another way I + + + align:start position:0% +negative net charge or another way I +ought to think about it is is look I'm + + align:start position:0% +ought to think about it is is look I'm + + + align:start position:0% +ought to think about it is is look I'm +running this converter back and forth + + align:start position:0% +running this converter back and forth + + + align:start position:0% +running this converter back and forth +between State 1 and state two in + + align:start position:0% +between State 1 and state two in + + + align:start position:0% +between State 1 and state two in +periodic steady state + + align:start position:0% +periodic steady state + + + align:start position:0% +periodic steady state +right what is the net charge that I'm + + align:start position:0% +right what is the net charge that I'm + + + align:start position:0% +right what is the net charge that I'm +going to transfer through the capacitor + + align:start position:0% +going to transfer through the capacitor + + + align:start position:0% +going to transfer through the capacitor +in periodic steady + + align:start position:0% +in periodic steady + + + align:start position:0% +in periodic steady +state zero right so that means that + + align:start position:0% +state zero right so that means that + + + align:start position:0% +state zero right so that means that +Delta + + align:start position:0% +Delta + + + align:start position:0% +Delta +qc1 the charge transferred onto the + + align:start position:0% +qc1 the charge transferred onto the + + + align:start position:0% +qc1 the charge transferred onto the +capacitor in state one plus Delta qc2 + + align:start position:0% +capacitor in state one plus Delta qc2 + + + align:start position:0% +capacitor in state one plus Delta qc2 +the charge transfer onto the capacitor + + align:start position:0% +the charge transfer onto the capacitor + + + align:start position:0% +the charge transfer onto the capacitor +State 2 better add to zero and you can + + align:start position:0% +State 2 better add to zero and you can + + + align:start position:0% +State 2 better add to zero and you can +see that it does if I write it this way + + align:start position:0% +see that it does if I write it this way + + + align:start position:0% +see that it does if I write it this way +right it's C vnus 2v out plus minus C + + align:start position:0% +right it's C vnus 2v out plus minus C + + + align:start position:0% +right it's C vnus 2v out plus minus C +vnus 2v out so they add to zero so + + align:start position:0% +vnus 2v out so they add to zero so + + + align:start position:0% +vnus 2v out so they add to zero so +indeed if I made the assumption that + + align:start position:0% +indeed if I made the assumption that + + + align:start position:0% +indeed if I made the assumption that +it's charged to its initial and final + + align:start position:0% +it's charged to its initial and final + + + align:start position:0% +it's charged to its initial and final +States um this does satisfy the periodic + + align:start position:0% +States um this does satisfy the periodic + + + align:start position:0% +States um this does satisfy the periodic +St state requirements on the + + align:start position:0% +St state requirements on the + + + align:start position:0% +St state requirements on the +capacitor okay any questions about + + align:start position:0% +capacitor okay any questions about + + + align:start position:0% +capacitor okay any questions about +that so let's just say what + + align:start position:0% +that so let's just say what + + + align:start position:0% +that so let's just say what +happens what's Delta Q in in state 2 + + align:start position:0% +happens what's Delta Q in in state 2 + + + align:start position:0% +happens what's Delta Q in in state 2 +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +anybody tell me + + align:start position:0% + + + + align:start position:0% + +that this is + + align:start position:0% +that this is + + + align:start position:0% +that this is +VN this is I in how much charge is + + align:start position:0% +VN this is I in how much charge is + + + align:start position:0% +VN this is I in how much charge is +transferred into the + + align:start position:0% +transferred into the + + + align:start position:0% +transferred into the +input in state + + align:start position:0% +input in state + + + align:start position:0% +input in state +two zero right no charge transfering the + + align:start position:0% +two zero right no charge transfering the + + + align:start position:0% +two zero right no charge transfering the +input okay how much charge is + + align:start position:0% +input okay how much charge is + + + align:start position:0% +input okay how much charge is +transferred to the + + align:start position:0% +transferred to the + + + align:start position:0% +transferred to the +output in state + + align:start position:0% + + + + align:start position:0% + +two well + + align:start position:0% +two well + + + align:start position:0% +two well +uh this is Let's Be careful about signs + + align:start position:0% +uh this is Let's Be careful about signs + + + align:start position:0% +uh this is Let's Be careful about signs +here here's V out here's I out right the + + align:start position:0% +here here's V out here's I out right the + + + align:start position:0% +here here's V out here's I out right the +negative of the capacitor current is + + align:start position:0% +negative of the capacitor current is + + + align:start position:0% +negative of the capacitor current is +going into the output so whatever charge + + align:start position:0% +going into the output so whatever charge + + + align:start position:0% +going into the output so whatever charge +went into the capacitor the negative of + + align:start position:0% +went into the capacitor the negative of + + + align:start position:0% +went into the capacitor the negative of +that charge went into the output right + + align:start position:0% +that charge went into the output right + + + align:start position:0% +that charge went into the output right +so Delta Q out2 must be positive + + align:start position:0% +so Delta Q out2 must be positive + + + align:start position:0% +so Delta Q out2 must be positive +c v in minus 2v out + + align:start position:0% + + + + align:start position:0% + +that make sense to + + align:start position:0% + + + + align:start position:0% + +everybody okay so uh what is the we know + + align:start position:0% +everybody okay so uh what is the we know + + + align:start position:0% +everybody okay so uh what is the we know +that the net total charge transferred on + + align:start position:0% +that the net total charge transferred on + + + align:start position:0% +that the net total charge transferred on +this energy storage capacitor in + + align:start position:0% +this energy storage capacitor in + + + align:start position:0% +this energy storage capacitor in +periodic steady state better be zero + + align:start position:0% +periodic steady state better be zero + + + align:start position:0% +periodic steady state better be zero +right but that's not true of the input + + align:start position:0% +right but that's not true of the input + + + align:start position:0% +right but that's not true of the input +of the output so why don't we just find + + align:start position:0% +of the output so why don't we just find + + + align:start position:0% +of the output so why don't we just find +out what that is um we could then + + align:start position:0% +out what that is um we could then + + + align:start position:0% +out what that is um we could then +write um Delta + + align:start position:0% +write um Delta + + + align:start position:0% +write um Delta +qn is equal to Q + + align:start position:0% +qn is equal to Q + + + align:start position:0% +qn is equal to Q +n in state 1 plus Delta Q in in state 2 + + align:start position:0% +n in state 1 plus Delta Q in in state 2 + + + align:start position:0% +n in state 1 plus Delta Q in in state 2 +and if I just add those up that's going + + align:start position:0% +and if I just add those up that's going + + + align:start position:0% +and if I just add those up that's going +to be 2 c v in minus 2v + + align:start position:0% +to be 2 c v in minus 2v + + + align:start position:0% +to be 2 c v in minus 2v +out okay and Delta Q + + align:start position:0% +out okay and Delta Q + + + align:start position:0% +out okay and Delta Q +out is going to be equal to Delta Q out + + align:start position:0% +out is going to be equal to Delta Q out + + + align:start position:0% +out is going to be equal to Delta Q out +in state one and Delta Q + + align:start position:0% +in state one and Delta Q + + + align:start position:0% +in state one and Delta Q +out in state two and if I add those up + + align:start position:0% +out in state two and if I add those up + + + align:start position:0% +out in state two and if I add those up +it's going to be + + align:start position:0% +it's going to be + + + align:start position:0% +it's going to be +minus c v Inus 2v + + align:start position:0% +minus c v Inus 2v + + + align:start position:0% +minus c v Inus 2v +out okay + + align:start position:0% +out okay + + + align:start position:0% +out okay +now how much what's the current at the + + align:start position:0% +now how much what's the current at the + + + align:start position:0% +now how much what's the current at the +input on average + + align:start position:0% + + + + align:start position:0% + +yeah uh yes thank + + align:start position:0% +yeah uh yes thank + + + align:start position:0% +yeah uh yes thank +you huh how did I do + + align:start position:0% +you huh how did I do + + + align:start position:0% +you huh how did I do +that well it's easier to do it this + + align:start position:0% + + + + align:start position:0% + +way thank you Somebody's Watching okay + + align:start position:0% +way thank you Somebody's Watching okay + + + align:start position:0% +way thank you Somebody's Watching okay +so um we have our input and output net + + align:start position:0% +so um we have our input and output net + + + align:start position:0% +so um we have our input and output net +charge okay if I wanted to talk about + + align:start position:0% +charge okay if I wanted to talk about + + + align:start position:0% +charge okay if I wanted to talk about +the average current going to the input + + align:start position:0% +the average current going to the input + + + align:start position:0% +the average current going to the input +or the output averaged over a + + align:start position:0% +or the output averaged over a + + + align:start position:0% +or the output averaged over a +cycle really it's the charge divided by + + align:start position:0% +cycle really it's the charge divided by + + + align:start position:0% +cycle really it's the charge divided by +the period or equivalently the charge + + align:start position:0% +the period or equivalently the charge + + + align:start position:0% +the period or equivalently the charge +times the switching frequency right so + + align:start position:0% +times the switching frequency right so + + + align:start position:0% +times the switching frequency right so +the local average in or the average in + + align:start position:0% +the local average in or the average in + + + align:start position:0% +the local average in or the average in +periodic steady state I could infer from + + align:start position:0% +periodic steady state I could infer from + + + align:start position:0% +periodic steady state I could infer from +this is that uh I + + align:start position:0% + + + + align:start position:0% + +in is equal to uh c times the switching + + align:start position:0% +in is equal to uh c times the switching + + + align:start position:0% +in is equal to uh c times the switching +frequency it's one over the period + + align:start position:0% +frequency it's one over the period + + + align:start position:0% +frequency it's one over the period +times uh V in minus 2v + + align:start position:0% + + + + align:start position:0% + +out and I should put my minus sign here + + align:start position:0% +out and I should put my minus sign here + + + align:start position:0% +out and I should put my minus sign here +and that's this is the current going + + align:start position:0% +and that's this is the current going + + + align:start position:0% +and that's this is the current going +into the input right uh and likewise I + + align:start position:0% +into the input right uh and likewise I + + + align:start position:0% +into the input right uh and likewise I +out is equal to 2 c f switch time vnus + + align:start position:0% +out is equal to 2 c f switch time vnus + + + align:start position:0% +out is equal to 2 c f switch time vnus +2v + + align:start position:0% +2v + + + align:start position:0% +2v +out okay so if you look at this the + + align:start position:0% +out okay so if you look at this the + + + align:start position:0% +out okay so if you look at this the +magnitude of I + + align:start position:0% +magnitude of I + + + align:start position:0% +magnitude of I +out is equal to 2 * the magnitude of I + + align:start position:0% +out is equal to 2 * the magnitude of I + + + align:start position:0% +out is equal to 2 * the magnitude of I +in okay why because what happens is + + align:start position:0% +in okay why because what happens is + + + align:start position:0% +in okay why because what happens is +essentially and and what's the re deal + + align:start position:0% +essentially and and what's the re deal + + + align:start position:0% +essentially and and what's the re deal +with the minus sign the minus sign is + + align:start position:0% +with the minus sign the minus sign is + + + align:start position:0% +with the minus sign the minus sign is +because I chose to Define I in going + + align:start position:0% +because I chose to Define I in going + + + align:start position:0% +because I chose to Define I in going +this way had I defined it going this way + + align:start position:0% +this way had I defined it going this way + + + align:start position:0% +this way had I defined it going this way +I'd have I out is equal to twice I in + + align:start position:0% +I'd have I out is equal to twice I in + + + align:start position:0% +I'd have I out is equal to twice I in +right but let's just worry about the + + align:start position:0% +right but let's just worry about the + + + align:start position:0% +right but let's just worry about the +magnitudes here so what's going on in + + align:start position:0% +magnitudes here so what's going on in + + + align:start position:0% +magnitudes here so what's going on in +the first part of the cycle I dump a + + align:start position:0% +the first part of the cycle I dump a + + + align:start position:0% +the first part of the cycle I dump a +certain amount of charge from the input + + align:start position:0% +certain amount of charge from the input + + + align:start position:0% +certain amount of charge from the input +to the output through the capacitor I + + align:start position:0% +to the output through the capacitor I + + + align:start position:0% +to the output through the capacitor I +charge the capacitor up so that's some + + align:start position:0% +charge the capacitor up so that's some + + + align:start position:0% +charge the capacitor up so that's some +amount of charge in the second part of + + align:start position:0% +amount of charge in the second part of + + + align:start position:0% +amount of charge in the second part of +the cycle this capacitor then dumps that + + align:start position:0% +the cycle this capacitor then dumps that + + + align:start position:0% +the cycle this capacitor then dumps that +same amount of charge into the output + + align:start position:0% +same amount of charge into the output + + + align:start position:0% +same amount of charge into the output +again so the output gets twice the + + align:start position:0% +again so the output gets twice the + + + align:start position:0% +again so the output gets twice the +amount of charge the input over the + + align:start position:0% +amount of charge the input over the + + + align:start position:0% +amount of charge the input over the +cycle and then I go back to the next + + align:start position:0% +cycle and then I go back to the next + + + align:start position:0% +cycle and then I go back to the next +cycle and I + + align:start position:0% +cycle and I + + + align:start position:0% +cycle and I +repeat okay so whatever the current + + align:start position:0% +repeat okay so whatever the current + + + align:start position:0% +repeat okay so whatever the current +coming in from coming coming into the + + align:start position:0% +coming in from coming coming into the + + + align:start position:0% +coming in from coming coming into the +converter from the input is exactly half + + align:start position:0% +converter from the input is exactly half + + + align:start position:0% +converter from the input is exactly half +the current going to the output by + + align:start position:0% +the current going to the output by + + + align:start position:0% +the current going to the output by +periodic steady state and charge balance + + align:start position:0% +periodic steady state and charge balance + + + align:start position:0% +periodic steady state and charge balance +on the + + align:start position:0% +on the + + + align:start position:0% +on the +capacitor okay any questions about that + + align:start position:0% + + + + align:start position:0% + +I should say that this is the defining + + align:start position:0% +I should say that this is the defining + + + align:start position:0% +I should say that this is the defining +feature of a switch capacitor converter + + align:start position:0% +feature of a switch capacitor converter + + + align:start position:0% +feature of a switch capacitor converter +okay you will always have some rational + + align:start position:0% +okay you will always have some rational + + + align:start position:0% +okay you will always have some rational +relationship rational meaning you know + + align:start position:0% +relationship rational meaning you know + + + align:start position:0% +relationship rational meaning you know +an actual fraction relating the current + + align:start position:0% +an actual fraction relating the current + + + align:start position:0% +an actual fraction relating the current +from the input to the current on the + + align:start position:0% +from the input to the current on the + + + align:start position:0% +from the input to the current on the +output why because this is a very simple + + align:start position:0% +output why because this is a very simple + + + align:start position:0% +output why because this is a very simple +converter we've got one capacitor that + + align:start position:0% +converter we've got one capacitor that + + + align:start position:0% +converter we've got one capacitor that +we're flipping around but generally + + align:start position:0% +we're flipping around but generally + + + align:start position:0% +we're flipping around but generally +you're going to be taking energy storing + + align:start position:0% +you're going to be taking energy storing + + + align:start position:0% +you're going to be taking energy storing +charge from the input doing something + + align:start position:0% +charge from the input doing something + + + align:start position:0% +charge from the input doing something +and throwing it to the output and those + + align:start position:0% +and throwing it to the output and those + + + align:start position:0% +and throwing it to the output and those +are always going to be related in some + + align:start position:0% +are always going to be related in some + + + align:start position:0% +are always going to be related in some +rational + + align:start position:0% +rational + + + align:start position:0% +rational +way okay um so that's what the core + + align:start position:0% +way okay um so that's what the core + + + align:start position:0% +way okay um so that's what the core +thing that a switch capacitor converter + + align:start position:0% +thing that a switch capacitor converter + + + align:start position:0% +thing that a switch capacitor converter +do is by charge balance it's going to + + align:start position:0% +do is by charge balance it's going to + + + align:start position:0% +do is by charge balance it's going to +give you some con current conversion + + align:start position:0% +give you some con current conversion + + + align:start position:0% +give you some con current conversion +ratio between the input and the output + + align:start position:0% +ratio between the input and the output + + + align:start position:0% +ratio between the input and the output +that's fixed by the topology and the + + align:start position:0% +that's fixed by the topology and the + + + align:start position:0% +that's fixed by the topology and the +switching sequence + + align:start position:0% +switching sequence + + + align:start position:0% +switching sequence +okay + + align:start position:0% + + + + align:start position:0% + +um all right um what else can we say + + align:start position:0% +um all right um what else can we say + + + align:start position:0% +um all right um what else can we say +about about this well look at this + + align:start position:0% +about about this well look at this + + + align:start position:0% +about about this well look at this +relationship + + align:start position:0% +relationship + + + align:start position:0% +relationship +here first of all any questions about + + align:start position:0% +here first of all any questions about + + + align:start position:0% +here first of all any questions about +what got me to + + align:start position:0% + + + + align:start position:0% + +that yeah is this assuming a 50% duty + + align:start position:0% +that yeah is this assuming a 50% duty + + + align:start position:0% +that yeah is this assuming a 50% duty +cycle oh that's a good question so long + + align:start position:0% +cycle oh that's a good question so long + + + align:start position:0% +cycle oh that's a good question so long +as the intervals are such that I fully + + align:start position:0% +as the intervals are such that I fully + + + align:start position:0% +as the intervals are such that I fully +charge and fully discharge in each sub + + align:start position:0% +charge and fully discharge in each sub + + + align:start position:0% +charge and fully discharge in each sub +interval in state one and state two the + + align:start position:0% +interval in state one and state two the + + + align:start position:0% +interval in state one and state two the +actual Duty ratio doesn't matter in this + + align:start position:0% +actual Duty ratio doesn't matter in this + + + align:start position:0% +actual Duty ratio doesn't matter in this +mode of operation + + align:start position:0% +mode of operation + + + align:start position:0% +mode of operation +so the only thing I've assumed is that + + align:start position:0% +so the only thing I've assumed is that + + + align:start position:0% +so the only thing I've assumed is that +I'm waiting long enough in state one for + + align:start position:0% +I'm waiting long enough in state one for + + + align:start position:0% +I'm waiting long enough in state one for +the cap passor to get to his final + + align:start position:0% +the cap passor to get to his final + + + align:start position:0% +the cap passor to get to his final +voltage and I'm waiting long enough in + + align:start position:0% +voltage and I'm waiting long enough in + + + align:start position:0% +voltage and I'm waiting long enough in +state two for the passor to get to its + + align:start position:0% +state two for the passor to get to its + + + align:start position:0% +state two for the passor to get to its +final voltage and as long as I've waited + + align:start position:0% +final voltage and as long as I've waited + + + align:start position:0% +final voltage and as long as I've waited +long enough in both States what their + + align:start position:0% +long enough in both States what their + + + align:start position:0% +long enough in both States what their +actual fraction of on times are doesn't + + align:start position:0% +actual fraction of on times are doesn't + + + align:start position:0% +actual fraction of on times are doesn't +matter we'll come back to that shortly + + align:start position:0% +matter we'll come back to that shortly + + + align:start position:0% +matter we'll come back to that shortly +yeah I a question this is called the + + align:start position:0% +yeah I a question this is called the + + + align:start position:0% +yeah I a question this is called the +slow + + align:start position:0% +slow + + + align:start position:0% +slow +switching yes and like that's why we + + align:start position:0% +switching yes and like that's why we + + + align:start position:0% +switching yes and like that's why we +didn't include the culations this + + align:start position:0% +didn't include the culations this + + + align:start position:0% +didn't include the culations this +effects + + align:start position:0% +effects + + + align:start position:0% +effects +or like those switches there are + + align:start position:0% +or like those switches there are + + + align:start position:0% +or like those switches there are +represented as resistors yeah so like + + align:start position:0% +represented as resistors yeah so like + + + align:start position:0% +represented as resistors yeah so like +the the Char doesn't see resistance well + + align:start position:0% +the the Char doesn't see resistance well + + + align:start position:0% +the the Char doesn't see resistance well +no it does we've we've included the + + align:start position:0% +no it does we've we've included the + + + align:start position:0% +no it does we've we've included the +resistance right all I've said is + + align:start position:0% +resistance right all I've said is + + + align:start position:0% +resistance right all I've said is +um the only thing you really need to + + align:start position:0% +um the only thing you really need to + + + align:start position:0% +um the only thing you really need to +know in this is where did the capacitor + + align:start position:0% +know in this is where did the capacitor + + + align:start position:0% +know in this is where did the capacitor +start in terms of its voltage and where + + align:start position:0% +start in terms of its voltage and where + + + align:start position:0% +start in terms of its voltage and where +did it end and if you know that then you + + align:start position:0% +did it end and if you know that then you + + + align:start position:0% +did it end and if you know that then you +know how much charge went into it so we + + align:start position:0% +know how much charge went into it so we + + + align:start position:0% +know how much charge went into it so we +have actually included the effect of the + + align:start position:0% +have actually included the effect of the + + + align:start position:0% +have actually included the effect of the +resistances it's those RC charging + + align:start position:0% +resistances it's those RC charging + + + align:start position:0% +resistances it's those RC charging +things if the r if the resistances get + + align:start position:0% +things if the r if the resistances get + + + align:start position:0% +things if the r if the resistances get +small I just make those RC chargings + + align:start position:0% +small I just make those RC chargings + + + align:start position:0% +small I just make those RC chargings +shorter okay I see thanks yeah but + + align:start position:0% +shorter okay I see thanks yeah but + + + align:start position:0% +shorter okay I see thanks yeah but +wouldn't wouldn't the on State and off + + align:start position:0% +wouldn't wouldn't the on State and off + + + align:start position:0% +wouldn't wouldn't the on State and off +State voltages + + align:start position:0% +State voltages + + + align:start position:0% +State voltages +change wouldn't there just wouldn't + + align:start position:0% +change wouldn't there just wouldn't + + + align:start position:0% +change wouldn't there just wouldn't +there be potential differences across + + align:start position:0% +there be potential differences across + + + align:start position:0% +there be potential differences across +the resistors well um if I've if I've + + align:start position:0% +the resistors well um if I've if I've + + + align:start position:0% +the resistors well um if I've if I've +assumed that the capacitor is fully + + align:start position:0% +assumed that the capacitor is fully + + + align:start position:0% +assumed that the capacitor is fully +charged the vol voltage across this + + align:start position:0% +charged the vol voltage across this + + + align:start position:0% +charged the vol voltage across this +resistor went to Zero by the end right + + align:start position:0% +resistor went to Zero by the end right + + + align:start position:0% +resistor went to Zero by the end right +so the only assumption I've made is you + + align:start position:0% +so the only assumption I've made is you + + + align:start position:0% +so the only assumption I've made is you +know this capacitor charges once the + + align:start position:0% +know this capacitor charges once the + + + align:start position:0% +know this capacitor charges once the +capacitor current goes to zero these + + align:start position:0% +capacitor current goes to zero these + + + align:start position:0% +capacitor current goes to zero these +voltage drops go to + + align:start position:0% +voltage drops go to + + + align:start position:0% +voltage drops go to +zero yeah we'll relax that assumption + + align:start position:0% +zero yeah we'll relax that assumption + + + align:start position:0% +zero yeah we'll relax that assumption +shortly okay so let me start from this + + align:start position:0% +shortly okay so let me start from this + + + align:start position:0% +shortly okay so let me start from this +relationship and let me see if I can + + align:start position:0% +relationship and let me see if I can + + + align:start position:0% +relationship and let me see if I can +give you what the voltage relationship + + align:start position:0% +give you what the voltage relationship + + + align:start position:0% +give you what the voltage relationship +is I've sort of told you here this is + + align:start position:0% +is I've sort of told you here this is + + + align:start position:0% +is I've sort of told you here this is +the current relationship of the + + align:start position:0% +the current relationship of the + + + align:start position:0% +the current relationship of the +converter right that's the fundamental + + align:start position:0% +converter right that's the fundamental + + + align:start position:0% +converter right that's the fundamental +thing that this converter does okay well + + align:start position:0% +thing that this converter does okay well + + + align:start position:0% +thing that this converter does okay well +how are the input and output voltage + + align:start position:0% +how are the input and output voltage + + + align:start position:0% +how are the input and output voltage +related well that's by this guy here + + align:start position:0% +related well that's by this guy here + + + align:start position:0% +related well that's by this guy here +okay and I can rearrange this so all I + + align:start position:0% +okay and I can rearrange this so all I + + + align:start position:0% +okay and I can rearrange this so all I +could do is maybe solve for V out and if + + align:start position:0% +could do is maybe solve for V out and if + + + align:start position:0% +could do is maybe solve for V out and if +I solve this equation for v out what I'm + + align:start position:0% +I solve this equation for v out what I'm + + + align:start position:0% +I solve this equation for v out what I'm +going to get is V + + align:start position:0% +going to get is V + + + align:start position:0% +going to get is V +out is equal to 12 of v + + align:start position:0% +out is equal to 12 of v + + + align:start position:0% +out is equal to 12 of v +in minus 1 + + align:start position:0% +in minus 1 + + + align:start position:0% +in minus 1 +over4 uh F switch C + + align:start position:0% +over4 uh F switch C + + + align:start position:0% +over4 uh F switch C +time I + + align:start position:0% + + + + align:start position:0% + +out okay this this is an equivalent + + align:start position:0% +out okay this this is an equivalent + + + align:start position:0% +out okay this this is an equivalent +statement as + + align:start position:0% +statement as + + + align:start position:0% +statement as +this + + align:start position:0% +this + + + align:start position:0% +this +okay so what does that mean in as a in a + + align:start position:0% +okay so what does that mean in as a in a + + + align:start position:0% +okay so what does that mean in as a in a +practical + + align:start position:0% +practical + + + align:start position:0% +practical +matter well let me create for you an + + align:start position:0% +matter well let me create for you an + + + align:start position:0% +matter well let me create for you an +equivalent circuit which does the same + + align:start position:0% +equivalent circuit which does the same + + + align:start position:0% +equivalent circuit which does the same +thing right so I told you you know this + + align:start position:0% +thing right so I told you you know this + + + align:start position:0% +thing right so I told you you know this +is + + align:start position:0% +is + + + align:start position:0% +is +my converter + + align:start position:0% +my converter + + + align:start position:0% +my converter +right if I wanted a periodic steady + + align:start position:0% +right if I wanted a periodic steady + + + align:start position:0% +right if I wanted a periodic steady +state model for what this thing does I + + align:start position:0% +state model for what this thing does I + + + align:start position:0% +state model for what this thing does I +have some input + + align:start position:0% + + + + align:start position:0% + +voltage right and then I have some load + + align:start position:0% +voltage right and then I have some load + + + align:start position:0% +voltage right and then I have some load +current connected to it that I'm going + + align:start position:0% +current connected to it that I'm going + + + align:start position:0% +current connected to it that I'm going +to call I out what is the relationship + + align:start position:0% +to call I out what is the relationship + + + align:start position:0% +to call I out what is the relationship +between what's in there it's defined by + + align:start position:0% +between what's in there it's defined by + + + align:start position:0% +between what's in there it's defined by +this well here's a circuit that gives + + align:start position:0% +this well here's a circuit that gives + + + align:start position:0% +this well here's a circuit that gives +you this same relationship right if I + + align:start position:0% +you this same relationship right if I + + + align:start position:0% +you this same relationship right if I +had an ideal 2:1 transform + + align:start position:0% + + + + align:start position:0% + +mer if this is VN this voltage would be + + align:start position:0% +mer if this is VN this voltage would be + + + align:start position:0% +mer if this is VN this voltage would be +half the + + align:start position:0% +half the + + + align:start position:0% +half the +in right because that's what the + + align:start position:0% +in right because that's what the + + + align:start position:0% +in right because that's what the +Transformer does and then I would have + + align:start position:0% +Transformer does and then I would have + + + align:start position:0% +Transformer does and then I would have +an equivalent + + align:start position:0% +an equivalent + + + align:start position:0% +an equivalent +resistance that would give me a voltage + + align:start position:0% +resistance that would give me a voltage + + + align:start position:0% +resistance that would give me a voltage +drop that was I out time 1 over4 F + + align:start position:0% +drop that was I out time 1 over4 F + + + align:start position:0% +drop that was I out time 1 over4 F +switch so I'd have an equivalent + + align:start position:0% +switch so I'd have an equivalent + + + align:start position:0% +switch so I'd have an equivalent +resistance of 1 over 4 F switch C + + align:start position:0% +resistance of 1 over 4 F switch C + + + align:start position:0% +resistance of 1 over 4 F switch C +okay and I could put this whole thing in + + align:start position:0% +okay and I could put this whole thing in + + + align:start position:0% +okay and I could put this whole thing in +a + + align:start position:0% + + + + align:start position:0% + +box and this is a + + align:start position:0% +box and this is a + + + align:start position:0% +box and this is a +DC equivalent model for how this thing + + align:start position:0% +DC equivalent model for how this thing + + + align:start position:0% +DC equivalent model for how this thing +behaves right in other words this is V + + align:start position:0% + + + + align:start position:0% + +out so this gives me the right + + align:start position:0% +out so this gives me the right + + + align:start position:0% +out so this gives me the right +relationships between V in and V out + + align:start position:0% +relationships between V in and V out + + + align:start position:0% +relationships between V in and V out +right V out is half VN + + align:start position:0% +right V out is half VN + + + align:start position:0% +right V out is half VN +minus um + + align:start position:0% +minus um + + + align:start position:0% +minus um +minus the uh voltage drop across this + + align:start position:0% +minus the uh voltage drop across this + + + align:start position:0% +minus the uh voltage drop across this +which is I out over 4 CF + + align:start position:0% +which is I out over 4 CF + + + align:start position:0% +which is I out over 4 CF +switch likewise if I have a current + + align:start position:0% +switch likewise if I have a current + + + align:start position:0% +switch likewise if I have a current +coming I out this way the current this + + align:start position:0% +coming I out this way the current this + + + align:start position:0% +coming I out this way the current this +way through the ideal Transformer is + + align:start position:0% +way through the ideal Transformer is + + + align:start position:0% +way through the ideal Transformer is +going to be exactly half of that right + + align:start position:0% +going to be exactly half of that right + + + align:start position:0% +going to be exactly half of that right +and that means the current this way is + + align:start position:0% +and that means the current this way is + + + align:start position:0% +and that means the current this way is +minus 12 I out all right so this model + + align:start position:0% +minus 12 I out all right so this model + + + align:start position:0% +minus 12 I out all right so this model +in yellow here precisely captures the + + align:start position:0% +in yellow here precisely captures the + + + align:start position:0% +in yellow here precisely captures the +the average circuit behavior of this + + align:start position:0% +the average circuit behavior of this + + + align:start position:0% +the average circuit behavior of this +system does that make sense + + align:start position:0% + + + + align:start position:0% + +everybody now this is this + + align:start position:0% +everybody now this is this + + + align:start position:0% +everybody now this is this +converter any other switch capacitor + + align:start position:0% +converter any other switch capacitor + + + align:start position:0% +converter any other switch capacitor +converter I want to model you can model + + align:start position:0% +converter I want to model you can model + + + align:start position:0% +converter I want to model you can model +likewise as + + align:start position:0% +likewise as + + + align:start position:0% +likewise as +some ideal Transformer + + align:start position:0% +some ideal Transformer + + + align:start position:0% +some ideal Transformer +relationship this gives me my current + + align:start position:0% +relationship this gives me my current + + + align:start position:0% +relationship this gives me my current +conversion ratio right this the the + + align:start position:0% +conversion ratio right this the the + + + align:start position:0% +conversion ratio right this the the +input and the output current are related + + align:start position:0% +input and the output current are related + + + align:start position:0% +input and the output current are related +by the ideal Transformer and then a + + align:start position:0% +by the ideal Transformer and then a + + + align:start position:0% +by the ideal Transformer and then a +voltage drop that's related by some uh + + align:start position:0% +voltage drop that's related by some uh + + + align:start position:0% +voltage drop that's related by some uh +equivalent resistance that's related to + + align:start position:0% +equivalent resistance that's related to + + + align:start position:0% +equivalent resistance that's related to +the energy transfer capacitors and the + + align:start position:0% +the energy transfer capacitors and the + + + align:start position:0% +the energy transfer capacitors and the +switching frequency okay so the details + + align:start position:0% +switching frequency okay so the details + + + align:start position:0% +switching frequency okay so the details +will vary but this model really captures + + align:start position:0% +will vary but this model really captures + + + align:start position:0% +will vary but this model really captures +what's going on okay now if I asked if I + + align:start position:0% +what's going on okay now if I asked if I + + + align:start position:0% +what's going on okay now if I asked if I +said well what's a what's an out you + + align:start position:0% +said well what's a what's an out you + + + align:start position:0% +said well what's a what's an out you +know if I wanted to just look back from + + align:start position:0% +know if I wanted to just look back from + + + align:start position:0% +know if I wanted to just look back from +the output and get a Fant equivalent + + align:start position:0% +the output and get a Fant equivalent + + + align:start position:0% +the output and get a Fant equivalent +looking backwards all I would see is + + align:start position:0% +looking backwards all I would see is + + + align:start position:0% +looking backwards all I would see is +another way to think about this is 1 12 + + align:start position:0% +another way to think about this is 1 12 + + + align:start position:0% +another way to think about this is 1 12 +VN right is a th in voltage and the F + + align:start position:0% +VN right is a th in voltage and the F + + + align:start position:0% +VN right is a th in voltage and the F +resistance would be + + align:start position:0% +resistance would be + + + align:start position:0% +resistance would be +req is equal to 1 over4 F switch + + align:start position:0% +req is equal to 1 over4 F switch + + + align:start position:0% +req is equal to 1 over4 F switch +C okay this is a Fant equivalent look + + align:start position:0% +C okay this is a Fant equivalent look + + + align:start position:0% +C okay this is a Fant equivalent look +model looking back into the switch + + align:start position:0% +model looking back into the switch + + + align:start position:0% +model looking back into the switch +capacitor converter from some at least + + align:start position:0% +capacitor converter from some at least + + + align:start position:0% +capacitor converter from some at least +the DC this is + + align:start position:0% +the DC this is + + + align:start position:0% +the DC this is +legitimate does that make sense + + align:start position:0% + + + + align:start position:0% + +everybody now we could say what's the + + align:start position:0% +everybody now we could say what's the + + + align:start position:0% +everybody now we could say what's the +efficiency of the + + align:start position:0% +efficiency of the + + + align:start position:0% +efficiency of the +converter okay well the + + align:start position:0% +converter okay well the + + + align:start position:0% +converter okay well the +efficiency is equal + + align:start position:0% +efficiency is equal + + + align:start position:0% +efficiency is equal +to um V out I + + align:start position:0% + + + + align:start position:0% + +out divided by VN or minus VN I in right + + align:start position:0% +out divided by VN or minus VN I in right + + + align:start position:0% +out divided by VN or minus VN I in right +and since I + + align:start position:0% +and since I + + + align:start position:0% +and since I +out is + + align:start position:0% +out is + + + align:start position:0% +out is +um I out is twice minus I in this would + + align:start position:0% +um I out is twice minus I in this would + + + align:start position:0% +um I out is twice minus I in this would +be equal to + + align:start position:0% +be equal to + + + align:start position:0% +be equal to +um + + align:start position:0% +um + + + align:start position:0% +um +2 time V out over + + align:start position:0% + + + + align:start position:0% + +VN + + align:start position:0% +VN + + + align:start position:0% +VN +right and we have an expression for V + + align:start position:0% +right and we have an expression for V + + + align:start position:0% +right and we have an expression for V +out right here I could write this as + + align:start position:0% +out right here I could write this as + + + align:start position:0% +out right here I could write this as +also equal to V out over 12 + + align:start position:0% +also equal to V out over 12 + + + align:start position:0% +also equal to V out over 12 +VN so to the extent that V out is + + align:start position:0% +VN so to the extent that V out is + + + align:start position:0% +VN so to the extent that V out is +smaller than half in the efficiency is + + align:start position:0% +smaller than half in the efficiency is + + + align:start position:0% +smaller than half in the efficiency is +less than one right well we can see see + + align:start position:0% +less than one right well we can see see + + + align:start position:0% +less than one right well we can see see +that the output is smaller than half in + + align:start position:0% +that the output is smaller than half in + + + align:start position:0% +that the output is smaller than half in +by whatever drop is across this + + align:start position:0% +by whatever drop is across this + + + align:start position:0% +by whatever drop is across this +resistor right so this model is actually + + align:start position:0% +resistor right so this model is actually + + + align:start position:0% +resistor right so this model is actually +useful for calculating eff this this + + align:start position:0% +useful for calculating eff this this + + + align:start position:0% +useful for calculating eff this this +model is actually useful for calculating + + align:start position:0% +model is actually useful for calculating + + + align:start position:0% +model is actually useful for calculating +efficiency as well and I could rewrite + + align:start position:0% +efficiency as well and I could rewrite + + + align:start position:0% +efficiency as well and I could rewrite +that if I plug that in what I would get + + align:start position:0% +that if I plug that in what I would get + + + align:start position:0% +that if I plug that in what I would get +is + + align:start position:0% +is + + + align:start position:0% +is +um I could rewrite this as what the + + align:start position:0% +um I could rewrite this as what the + + + align:start position:0% +um I could rewrite this as what the +efficiency simply is equal to 1 minus I + + align:start position:0% +efficiency simply is equal to 1 minus I + + + align:start position:0% +efficiency simply is equal to 1 minus I +out + + align:start position:0% +out + + + align:start position:0% +out +times + + align:start position:0% +times + + + align:start position:0% +times +req over + + align:start position:0% +req over + + + align:start position:0% +req over +12n okay this is just illustrating if my + + align:start position:0% +12n okay this is just illustrating if my + + + align:start position:0% +12n okay this is just illustrating if my +if my load current goes to zero the + + align:start position:0% +if my load current goes to zero the + + + align:start position:0% +if my load current goes to zero the +efficiency then goes to + + align:start position:0% +efficiency then goes to + + + align:start position:0% +efficiency then goes to +one if my load current gets really big + + align:start position:0% +one if my load current gets really big + + + align:start position:0% +one if my load current gets really big +the output droops down right as my + + align:start position:0% +the output droops down right as my + + + align:start position:0% +the output droops down right as my +output gets really big I get a bigger + + align:start position:0% +output gets really big I get a bigger + + + align:start position:0% +output gets really big I get a bigger +and bigger drop across this equivalent + + align:start position:0% +and bigger drop across this equivalent + + + align:start position:0% +and bigger drop across this equivalent +resistor and my efficiency starts to + + align:start position:0% +resistor and my efficiency starts to + + + align:start position:0% +resistor and my efficiency starts to +decline + + align:start position:0% +decline + + + align:start position:0% +decline +does that make sense everybody now when + + align:start position:0% +does that make sense everybody now when + + + align:start position:0% +does that make sense everybody now when +I'm saying this what what losses am i + + align:start position:0% +I'm saying this what what losses am i + + + align:start position:0% +I'm saying this what what losses am i +counting when I'm calculating this + + align:start position:0% +counting when I'm calculating this + + + align:start position:0% +counting when I'm calculating this +efficiency the losses I'm counting are + + align:start position:0% +efficiency the losses I'm counting are + + + align:start position:0% +efficiency the losses I'm counting are +essentially the resistor loss the losses + + align:start position:0% +essentially the resistor loss the losses + + + align:start position:0% +essentially the resistor loss the losses +in the switch resistances and in the + + align:start position:0% +in the switch resistances and in the + + + align:start position:0% +in the switch resistances and in the +Capac like any parasitics in the + + align:start position:0% +Capac like any parasitics in the + + + align:start position:0% +Capac like any parasitics in the +capacitor it's what we would call um + + align:start position:0% +capacitor it's what we would call um + + + align:start position:0% +capacitor it's what we would call um +sort of capacitor charging + + align:start position:0% +sort of capacitor charging + + + align:start position:0% +sort of capacitor charging +loss right so the only loss I'm I'm not + + align:start position:0% +loss right so the only loss I'm I'm not + + + align:start position:0% +loss right so the only loss I'm I'm not +counting like you know if these switch + + align:start position:0% +counting like you know if these switch + + + align:start position:0% +counting like you know if these switch +have gate drives and the Gate Drive gate + + align:start position:0% +have gate drives and the Gate Drive gate + + + align:start position:0% +have gate drives and the Gate Drive gate +capacit inside charge and discharge or + + align:start position:0% +capacit inside charge and discharge or + + + align:start position:0% +capacit inside charge and discharge or +other losses like that they're internal + + align:start position:0% +other losses like that they're internal + + + align:start position:0% +other losses like that they're internal +to the switches but the loss associated + + align:start position:0% +to the switches but the loss associated + + + align:start position:0% +to the switches but the loss associated +with Char the switches delivering + + align:start position:0% +with Char the switches delivering + + + align:start position:0% +with Char the switches delivering +current through to charge the capacitor + + align:start position:0% +current through to charge the capacitor + + + align:start position:0% +current through to charge the capacitor +and discharge the capacitor now it + + align:start position:0% +and discharge the capacitor now it + + + align:start position:0% +and discharge the capacitor now it +doesn't matter you notice the switch + + align:start position:0% +doesn't matter you notice the switch + + + align:start position:0% +doesn't matter you notice the switch +resistance isn't even in here anywhere + + align:start position:0% +resistance isn't even in here anywhere + + + align:start position:0% +resistance isn't even in here anywhere +it doesn't really matter what the switch + + align:start position:0% +it doesn't really matter what the switch + + + align:start position:0% +it doesn't really matter what the switch +resistance is okay the only constraint I + + align:start position:0% +resistance is okay the only constraint I + + + align:start position:0% +resistance is okay the only constraint I +have is that I have to finish charging + + align:start position:0% +have is that I have to finish charging + + + align:start position:0% +have is that I have to finish charging +and + + align:start position:0% +and + + + align:start position:0% +and +discharging okay and that's just because + + align:start position:0% +discharging okay and that's just because + + + align:start position:0% +discharging okay and that's just because +of you can do this by basically charge + + align:start position:0% +of you can do this by basically charge + + + align:start position:0% +of you can do this by basically charge +methods to to find out the + + align:start position:0% + + + + align:start position:0% + +efficiency could you could you say it + + align:start position:0% +efficiency could you could you say it + + + align:start position:0% +efficiency could you could you say it +again like where the power is being + + align:start position:0% +again like where the power is being + + + align:start position:0% +again like where the power is being +dissipated the power is being + + align:start position:0% +dissipated the power is being + + + align:start position:0% +dissipated the power is being +dissipated in if if if the + + align:start position:0% +dissipated in if if if the + + + align:start position:0% +dissipated in if if if the +only elements right I mean the power is + + align:start position:0% +only elements right I mean the power is + + + align:start position:0% +only elements right I mean the power is +being dissipated in any parasitic + + align:start position:0% +being dissipated in any parasitic + + + align:start position:0% +being dissipated in any parasitic +resistance in the charge and discharge + + align:start position:0% +resistance in the charge and discharge + + + align:start position:0% +resistance in the charge and discharge +path okay so if I turn the switch on it + + align:start position:0% +path okay so if I turn the switch on it + + + align:start position:0% +path okay so if I turn the switch on it +has some voltage drop across it or if + + align:start position:0% +has some voltage drop across it or if + + + align:start position:0% +has some voltage drop across it or if +the capacitor has some parasitic + + align:start position:0% +the capacitor has some parasitic + + + align:start position:0% +the capacitor has some parasitic +resistance + + align:start position:0% +resistance + + + align:start position:0% +resistance +it loses some energy in that what + + align:start position:0% +it loses some energy in that what + + + align:start position:0% +it loses some energy in that what +happens you you say well what happens if + + align:start position:0% +happens you you say well what happens if + + + align:start position:0% +happens you you say well what happens if +I make my switch resistance go to zero + + align:start position:0% +I make my switch resistance go to zero + + + align:start position:0% +I make my switch resistance go to zero +well all that happens is that the peak + + align:start position:0% +well all that happens is that the peak + + + align:start position:0% +well all that happens is that the peak +charging current gets + + align:start position:0% +charging current gets + + + align:start position:0% +charging current gets +higher and it goes for a shorter time + + align:start position:0% +higher and it goes for a shorter time + + + align:start position:0% +higher and it goes for a shorter time +and the total loss is the same thing + + align:start position:0% +and the total loss is the same thing + + + align:start position:0% +and the total loss is the same thing +okay so mathematically it works out the + + align:start position:0% +okay so mathematically it works out the + + + align:start position:0% +okay so mathematically it works out the +actual value of the resistance doesn't + + align:start position:0% +actual value of the resistance doesn't + + + align:start position:0% +actual value of the resistance doesn't +matter it doesn't even matter if the + + align:start position:0% +matter it doesn't even matter if the + + + align:start position:0% +matter it doesn't even matter if the +resistance is linear or nonlinear + + align:start position:0% +resistance is linear or nonlinear + + + align:start position:0% +resistance is linear or nonlinear +um but you get the same net loss so it's + + align:start position:0% +um but you get the same net loss so it's + + + align:start position:0% +um but you get the same net loss so it's +basically the CH the loss that I incur + + align:start position:0% +basically the CH the loss that I incur + + + align:start position:0% +basically the CH the loss that I incur +in putting the Capac charge on the + + align:start position:0% +in putting the Capac charge on the + + + align:start position:0% +in putting the Capac charge on the +capacitor and then taking the charge + + align:start position:0% +capacitor and then taking the charge + + + align:start position:0% +capacitor and then taking the charge +back off to the capacitor of the output + + align:start position:0% +back off to the capacitor of the output + + + align:start position:0% +back off to the capacitor of the output +that's the loss that's + + align:start position:0% +that's the loss that's + + + align:start position:0% +that's the loss that's +included yeah so if you use a smaller + + align:start position:0% +included yeah so if you use a smaller + + + align:start position:0% +included yeah so if you use a smaller +capacitor which takes less time to + + align:start position:0% +capacitor which takes less time to + + + align:start position:0% +capacitor which takes less time to +charge and charge can you see smaller + + align:start position:0% +charge and charge can you see smaller + + + align:start position:0% +charge and charge can you see smaller +losses + + align:start position:0% +losses + + + align:start position:0% +losses +ah so if I wanted to reduce my losses + + align:start position:0% +ah so if I wanted to reduce my losses + + + align:start position:0% +ah so if I wanted to reduce my losses +let's go back and look at my efficiency + + align:start position:0% +let's go back and look at my efficiency + + + align:start position:0% +let's go back and look at my efficiency +characteristic if I want smaller losses + + align:start position:0% +characteristic if I want smaller losses + + + align:start position:0% +characteristic if I want smaller losses +I should make req small right to make R + + align:start position:0% +I should make req small right to make R + + + align:start position:0% +I should make req small right to make R +equivalent small I should make either C + + align:start position:0% +equivalent small I should make either C + + + align:start position:0% +equivalent small I should make either C +big or switching frequency big and the + + align:start position:0% +big or switching frequency big and the + + + align:start position:0% +big or switching frequency big and the +notion is and we'll come we'll come back + + align:start position:0% +notion is and we'll come we'll come back + + + align:start position:0% +notion is and we'll come we'll come back +to this and we'll look at this next + + align:start position:0% +to this and we'll look at this next + + + align:start position:0% +to this and we'll look at this next +class it's sort of comes down to the + + align:start position:0% +class it's sort of comes down to the + + + align:start position:0% +class it's sort of comes down to the +amount I'm charging and discharging the + + align:start position:0% +amount I'm charging and discharging the + + + align:start position:0% +amount I'm charging and discharging the +capacitor when I when I charge the + + align:start position:0% +capacitor when I when I charge the + + + align:start position:0% +capacitor when I when I charge the +capacitor over a small tiny Delta + + align:start position:0% +capacitor over a small tiny Delta + + + align:start position:0% +capacitor over a small tiny Delta +voltage I don't lose much energy in + + align:start position:0% +voltage I don't lose much energy in + + + align:start position:0% +voltage I don't lose much energy in +doing it and so if I want lower loss + + align:start position:0% +doing it and so if I want lower loss + + + align:start position:0% +doing it and so if I want lower loss +it's a very great Insight on your part + + align:start position:0% +it's a very great Insight on your part + + + align:start position:0% +it's a very great Insight on your part +but if I want lower loss I want to make + + align:start position:0% +but if I want lower loss I want to make + + + align:start position:0% +but if I want lower loss I want to make +the capacitor bigger are not + + align:start position:0% +the capacitor bigger are not + + + align:start position:0% +the capacitor bigger are not +smaller for a given load + + align:start position:0% +smaller for a given load + + + align:start position:0% +smaller for a given load +current okay so this + + align:start position:0% +current okay so this + + + align:start position:0% +current okay so this +model + + align:start position:0% +model + + + align:start position:0% +model +um you know I in fact if I wanted if I + + align:start position:0% +um you know I in fact if I wanted if I + + + align:start position:0% +um you know I in fact if I wanted if I +put a resistive load on here the + + align:start position:0% +put a resistive load on here the + + + align:start position:0% +put a resistive load on here the +efficiency is exactly just the + + align:start position:0% +efficiency is exactly just the + + + align:start position:0% +efficiency is exactly just the +efficiency of a voltage + + align:start position:0% +efficiency of a voltage + + + align:start position:0% +efficiency of a voltage +divider right so it's it's um this is a + + align:start position:0% +divider right so it's it's um this is a + + + align:start position:0% +divider right so it's it's um this is a +very good model and the only thing that + + align:start position:0% +very good model and the only thing that + + + align:start position:0% +very good model and the only thing that +would Mo vary if I model any other + + align:start position:0% +would Mo vary if I model any other + + + align:start position:0% +would Mo vary if I model any other +switch capacitor converter would be this + + align:start position:0% +switch capacitor converter would be this + + + align:start position:0% +switch capacitor converter would be this +Transformer ratio which relates to that + + align:start position:0% +Transformer ratio which relates to that + + + align:start position:0% +Transformer ratio which relates to that +perfect current conversion ratio we + + align:start position:0% +perfect current conversion ratio we + + + align:start position:0% +perfect current conversion ratio we +calculated and what the exact value of + + align:start position:0% +calculated and what the exact value of + + + align:start position:0% +calculated and what the exact value of +this output resistance would look like + + align:start position:0% +this output resistance would look like + + + align:start position:0% +this output resistance would look like +okay which is again dictated by the + + align:start position:0% +okay which is again dictated by the + + + align:start position:0% +okay which is again dictated by the +losses okay + + align:start position:0% + + + + align:start position:0% + +questions + + align:start position:0% +questions + + + align:start position:0% +questions +so let's think about + + align:start position:0% +so let's think about + + + align:start position:0% +so let's think about +um what + + align:start position:0% +um what + + + align:start position:0% +um what +other uh case I might consider we said + + align:start position:0% +other uh case I might consider we said + + + align:start position:0% +other uh case I might consider we said +okay suppose I want to and by the way + + align:start position:0% +okay suppose I want to and by the way + + + align:start position:0% +okay suppose I want to and by the way +why do we like these converters because + + align:start position:0% +why do we like these converters because + + + align:start position:0% +why do we like these converters because +they can be hyper efficient if I go buy + + align:start position:0% +they can be hyper efficient if I go buy + + + align:start position:0% +they can be hyper efficient if I go buy +a a really big capacitor + + align:start position:0% +a a really big capacitor + + + align:start position:0% +a a really big capacitor +here or I switch really fast this + + align:start position:0% +here or I switch really fast this + + + align:start position:0% +here or I switch really fast this +equivalent resistance can be very small + + align:start position:0% +equivalent resistance can be very small + + + align:start position:0% +equivalent resistance can be very small +and I can get an almost perfect 2:1 + + align:start position:0% +and I can get an almost perfect 2:1 + + + align:start position:0% +and I can get an almost perfect 2:1 +voltage + + align:start position:0% +voltage + + + align:start position:0% +voltage +conversion okay and in fact people would + + align:start position:0% +conversion okay and in fact people would + + + align:start position:0% +conversion okay and in fact people would +call this thing a two to two to one step + + align:start position:0% +call this thing a two to two to one step + + + align:start position:0% +call this thing a two to two to one step +down switch capacitor converter why + + align:start position:0% +down switch capacitor converter why + + + align:start position:0% +down switch capacitor converter why +because they're thinking of the voltage + + align:start position:0% +because they're thinking of the voltage + + + align:start position:0% +because they're thinking of the voltage +right the the ideally speaking if I make + + align:start position:0% +right the the ideally speaking if I make + + + align:start position:0% +right the the ideally speaking if I make +this resist really small I'm really just + + align:start position:0% +this resist really small I'm really just + + + align:start position:0% +this resist really small I'm really just +doing sort of like an ideal Transformer + + align:start position:0% +doing sort of like an ideal Transformer + + + align:start position:0% +doing sort of like an ideal Transformer +2: + + align:start position:0% +2: + + + align:start position:0% +2: +one okay and so people would call that a + + align:start position:0% +one okay and so people would call that a + + + align:start position:0% +one okay and so people would call that a +2:1 on the other hand it's only + + align:start position:0% +2:1 on the other hand it's only + + + align:start position:0% +2:1 on the other hand it's only +approximately two: one because this is + + align:start position:0% +approximately two: one because this is + + + align:start position:0% +approximately two: one because this is +not zero this is some finite value of + + align:start position:0% +not zero this is some finite value of + + + align:start position:0% +not zero this is some finite value of +resistance what it is is a one to2 + + align:start position:0% +resistance what it is is a one to2 + + + align:start position:0% +resistance what it is is a one to2 +current converter switch capacitor + + align:start position:0% +current converter switch capacitor + + + align:start position:0% +current converter switch capacitor +converter and that relationship is + + align:start position:0% +converter and that relationship is + + + align:start position:0% +converter and that relationship is +precise right so you know what should + + align:start position:0% +precise right so you know what should + + + align:start position:0% +precise right so you know what should +people call this they should call this a + + align:start position:0% +people call this they should call this a + + + align:start position:0% +people call this they should call this a +one to two current conversion switch + + align:start position:0% +one to two current conversion switch + + + align:start position:0% +one to two current conversion switch +capacitor converter but that's not what + + align:start position:0% +capacitor converter but that's not what + + + align:start position:0% +capacitor converter but that's not what +they call it they call it a two to1 + + align:start position:0% +they call it they call it a two to1 + + + align:start position:0% +they call it they call it a two to1 +voltage converter because everybody + + align:start position:0% +voltage converter because everybody + + + align:start position:0% +voltage converter because everybody +likes to think about voltages okay so + + align:start position:0% +likes to think about voltages okay so + + + align:start position:0% +likes to think about voltages okay so +it's just you're stuck with the you're + + align:start position:0% +it's just you're stuck with the you're + + + align:start position:0% +it's just you're stuck with the you're +stuck with what people call things but + + align:start position:0% +stuck with what people call things but + + + align:start position:0% +stuck with what people call things but +maybe it's not fair um so what do I get + + align:start position:0% +maybe it's not fair um so what do I get + + + align:start position:0% +maybe it's not fair um so what do I get +um if I wanted to + + align:start position:0% +um if I wanted to + + + align:start position:0% +um if I wanted to +um go up in performance suppose I want + + align:start position:0% +um go up in performance suppose I want + + + align:start position:0% +um go up in performance suppose I want +so so when would I I should say when + + align:start position:0% +so so when would I I should say when + + + align:start position:0% +so so when would I I should say when +would I want to use a switch capacitor + + align:start position:0% +would I want to use a switch capacitor + + + align:start position:0% +would I want to use a switch capacitor +converter I'd want use switch capacitor + + align:start position:0% +converter I'd want use switch capacitor + + + align:start position:0% +converter I'd want use switch capacitor +converter for so for example I have you + + align:start position:0% +converter for so for example I have you + + + align:start position:0% +converter for so for example I have you +know 5 volts and I need 2.5 volts right + + align:start position:0% +know 5 volts and I need 2.5 volts right + + + align:start position:0% +know 5 volts and I need 2.5 volts right +I want exactly half the + + align:start position:0% +I want exactly half the + + + align:start position:0% +I want exactly half the +voltage then to the extent that I can + + align:start position:0% +voltage then to the extent that I can + + + align:start position:0% +voltage then to the extent that I can +make this equivalent resistance small + + align:start position:0% +make this equivalent resistance small + + + align:start position:0% +make this equivalent resistance small +this is a great converter on the other + + align:start position:0% +this is a great converter on the other + + + align:start position:0% +this is a great converter on the other +hand I wouldn't want to use this + + align:start position:0% +hand I wouldn't want to use this + + + align:start position:0% +hand I wouldn't want to use this +converter when my input voltage was 5 + + align:start position:0% +converter when my input voltage was 5 + + + align:start position:0% +converter when my input voltage was 5 +volts and my output voltage was 2 + + align:start position:0% +volts and my output voltage was 2 + + + align:start position:0% +volts and my output voltage was 2 +volts right because then my efficiency + + align:start position:0% +volts right because then my efficiency + + + align:start position:0% +volts right because then my efficiency +would be two 2 over 2.5 which isn't that + + align:start position:0% +would be two 2 over 2.5 which isn't that + + + align:start position:0% +would be two 2 over 2.5 which isn't that +high + + align:start position:0% +high + + + align:start position:0% +high +right so uh switch capacitors or + + align:start position:0% +right so uh switch capacitors or + + + align:start position:0% +right so uh switch capacitors or +converters are very efficient when your + + align:start position:0% +converters are very efficient when your + + + align:start position:0% +converters are very efficient when your +voltage conversion ratio is very close + + align:start position:0% +voltage conversion ratio is very close + + + align:start position:0% +voltage conversion ratio is very close +to the inverse of your intrinsic current + + align:start position:0% +to the inverse of your intrinsic current + + + align:start position:0% +to the inverse of your intrinsic current +conversion ratio and then their + + align:start position:0% +conversion ratio and then their + + + align:start position:0% +conversion ratio and then their +efficiency droops down outside of that + + align:start position:0% +efficiency droops down outside of that + + + align:start position:0% +efficiency droops down outside of that +range sometimes actually people use this + + align:start position:0% +range sometimes actually people use this + + + align:start position:0% +range sometimes actually people use this +and Vary this equivalent resistor to + + align:start position:0% +and Vary this equivalent resistor to + + + align:start position:0% +and Vary this equivalent resistor to +give yourself a linear regulator kind of + + align:start position:0% +give yourself a linear regulator kind of + + + align:start position:0% +give yourself a linear regulator kind of +action too so but instead of linear + + align:start position:0% +action too so but instead of linear + + + align:start position:0% +action too so but instead of linear +regulating down from VN you linear + + align:start position:0% +regulating down from VN you linear + + + align:start position:0% +regulating down from VN you linear +regulate down from half VN so you get an + + align:start position:0% +regulate down from half VN so you get an + + + align:start position:0% +regulate down from half VN so you get an +advantage that way but if you want to + + align:start position:0% +advantage that way but if you want to + + + align:start position:0% +advantage that way but if you want to +talk about pure switch mode operation + + align:start position:0% +talk about pure switch mode operation + + + align:start position:0% +talk about pure switch mode operation +you're usually trying to make this very + + align:start position:0% +you're usually trying to make this very + + + align:start position:0% +you're usually trying to make this very +small how do I make that small I either + + align:start position:0% +small how do I make that small I either + + + align:start position:0% +small how do I make that small I either +get big capacitors or I switch fast okay + + align:start position:0% +get big capacitors or I switch fast okay + + + align:start position:0% +get big capacitors or I switch fast okay +now there's an exception to what I + + align:start position:0% +now there's an exception to what I + + + align:start position:0% +now there's an exception to what I +said uh or a limit to what I said this + + align:start position:0% +said uh or a limit to what I said this + + + align:start position:0% +said uh or a limit to what I said this +operation is all in what I'm calling the + + align:start position:0% +operation is all in what I'm calling the + + + align:start position:0% +operation is all in what I'm calling the +what I've been calling the slow + + align:start position:0% +what I've been calling the slow + + + align:start position:0% +what I've been calling the slow +switching limit right this limit right + + align:start position:0% +switching limit right this limit right + + + align:start position:0% +switching limit right this limit right +here where I'm fully charging and fully + + align:start position:0% +here where I'm fully charging and fully + + + align:start position:0% +here where I'm fully charging and fully +discharging if I suppose I want to get + + align:start position:0% +discharging if I suppose I want to get + + + align:start position:0% +discharging if I suppose I want to get +higher efficiency and I'm for I'm + + align:start position:0% +higher efficiency and I'm for I'm + + + align:start position:0% +higher efficiency and I'm for I'm +forgetting about gate losses and + + align:start position:0% +forgetting about gate losses and + + + align:start position:0% +forgetting about gate losses and +capacitor discharge losses and stuff + + align:start position:0% +capacitor discharge losses and stuff + + + align:start position:0% +capacitor discharge losses and stuff +inside the switches I'm just talking + + align:start position:0% +inside the switches I'm just talking + + + align:start position:0% +inside the switches I'm just talking +about the charge transfer losses I can + + align:start position:0% +about the charge transfer losses I can + + + align:start position:0% +about the charge transfer losses I can +switch faster and faster and faster that + + align:start position:0% +switch faster and faster and faster that + + + align:start position:0% +switch faster and faster and faster that +output resistance keeps drooping right + + align:start position:0% +output resistance keeps drooping right + + + align:start position:0% +output resistance keeps drooping right +keeps getting smaller and that's better + + align:start position:0% +keeps getting smaller and that's better + + + align:start position:0% +keeps getting smaller and that's better +but eventually I get to the point where + + align:start position:0% +but eventually I get to the point where + + + align:start position:0% +but eventually I get to the point where +if I increase my switching frequency + + align:start position:0% +if I increase my switching frequency + + + align:start position:0% +if I increase my switching frequency +suppose I just keep each time period + + align:start position:0% +suppose I just keep each time period + + + align:start position:0% +suppose I just keep each time period +half + + align:start position:0% +half + + + align:start position:0% +half +that this time period is going to get so + + align:start position:0% +that this time period is going to get so + + + align:start position:0% +that this time period is going to get so +short that my capacitor doesn't fully + + align:start position:0% +short that my capacitor doesn't fully + + + align:start position:0% +short that my capacitor doesn't fully +charge + + align:start position:0% +charge + + + align:start position:0% +charge +up and he doesn't fully charge down + + align:start position:0% +up and he doesn't fully charge down + + + align:start position:0% +up and he doesn't fully charge down +right if I keep pushing my switching + + align:start position:0% +right if I keep pushing my switching + + + align:start position:0% +right if I keep pushing my switching +frequency up enough I'm going to violate + + align:start position:0% +frequency up enough I'm going to violate + + + align:start position:0% +frequency up enough I'm going to violate +the Assumption under which I did this + + align:start position:0% +the Assumption under which I did this + + + align:start position:0% +the Assumption under which I did this +analysis + + align:start position:0% +analysis + + + align:start position:0% +analysis +okay the extreme limit of that is the + + align:start position:0% +okay the extreme limit of that is the + + + align:start position:0% +okay the extreme limit of that is the +capacitor sitting close to some voltage + + align:start position:0% +capacitor sitting close to some voltage + + + align:start position:0% +capacitor sitting close to some voltage +and he only charges up and down a + + align:start position:0% +and he only charges up and down a + + + align:start position:0% +and he only charges up and down a +little right so in other words suppose I + + align:start position:0% +little right so in other words suppose I + + + align:start position:0% +little right so in other words suppose I +made my time scale really short and I + + align:start position:0% +made my time scale really short and I + + + align:start position:0% +made my time scale really short and I +will have you know here State one and + + align:start position:0% +will have you know here State one and + + + align:start position:0% +will have you know here State one and +here state + + align:start position:0% +here state + + + align:start position:0% +here state +two right and in state one he just does + + align:start position:0% +two right and in state one he just does + + + align:start position:0% +two right and in state one he just does +this he charges a tiny bit which is part + + align:start position:0% +this he charges a tiny bit which is part + + + align:start position:0% +this he charges a tiny bit which is part +of a much + + align:start position:0% +of a much + + + align:start position:0% +of a much +bigger RC + + align:start position:0% +bigger RC + + + align:start position:0% +bigger RC +charge and then in state two he + + align:start position:0% +charge and then in state two he + + + align:start position:0% +charge and then in state two he +discharges just a tiny + + align:start position:0% +discharges just a tiny + + + align:start position:0% +discharges just a tiny +bit which is part of a muchow longer RC + + align:start position:0% +bit which is part of a muchow longer RC + + + align:start position:0% +bit which is part of a muchow longer RC +time time charge right so I can almost + + align:start position:0% +time time charge right so I can almost + + + align:start position:0% +time time charge right so I can almost +think in the fast switching + + align:start position:0% + + + + align:start position:0% + +limit VC is almost + + align:start position:0% +limit VC is almost + + + align:start position:0% +limit VC is almost +constant right I don't have enough time + + align:start position:0% +constant right I don't have enough time + + + align:start position:0% +constant right I don't have enough time +to charge up or down substantially the + + align:start position:0% +to charge up or down substantially the + + + align:start position:0% +to charge up or down substantially the +Delta voltage I get is nowhere near the + + align:start position:0% +Delta voltage I get is nowhere near the + + + align:start position:0% +Delta voltage I get is nowhere near the +full + + align:start position:0% +full + + + align:start position:0% +full +swing okay and I can just start to think + + align:start position:0% +swing okay and I can just start to think + + + align:start position:0% +swing okay and I can just start to think +about the capacitor as being at constant + + align:start position:0% +about the capacitor as being at constant + + + align:start position:0% +about the capacitor as being at constant +voltage okay okay but it's a special + + align:start position:0% +voltage okay okay but it's a special + + + align:start position:0% +voltage okay okay but it's a special +constant voltage because nonetheless if + + align:start position:0% +constant voltage because nonetheless if + + + align:start position:0% +constant voltage because nonetheless if +I'm going to be in periodic steady state + + align:start position:0% +I'm going to be in periodic steady state + + + align:start position:0% +I'm going to be in periodic steady state +however much he charges in the first + + align:start position:0% +however much he charges in the first + + + align:start position:0% +however much he charges in the first +state must balance the Char amount of + + align:start position:0% +state must balance the Char amount of + + + align:start position:0% +state must balance the Char amount of +discharges in the second state right + + align:start position:0% +discharges in the second state right + + + align:start position:0% +discharges in the second state right +that I haven't gotten around that kind + + align:start position:0% +that I haven't gotten around that kind + + + align:start position:0% +that I haven't gotten around that kind +of rule uh but nonetheless we can think + + align:start position:0% +of rule uh but nonetheless we can think + + + align:start position:0% +of rule uh but nonetheless we can think +about this fast switching limit as the + + align:start position:0% +about this fast switching limit as the + + + align:start position:0% +about this fast switching limit as the +capacitor voltage almost becoming + + align:start position:0% +capacitor voltage almost becoming + + + align:start position:0% +capacitor voltage almost becoming +constant right so let's think about what + + align:start position:0% +constant right so let's think about what + + + align:start position:0% +constant right so let's think about what +would a converter do in the fast + + align:start position:0% +would a converter do in the fast + + + align:start position:0% +would a converter do in the fast +switching limit in the FSL + + align:start position:0% + + + + align:start position:0% + +um in state so so let me just think + + align:start position:0% +um in state so so let me just think + + + align:start position:0% +um in state so so let me just think +about I'm going to no now mentally + + align:start position:0% +about I'm going to no now mentally + + + align:start position:0% +about I'm going to no now mentally +replace this capacitor with just a fixed + + align:start position:0% +replace this capacitor with just a fixed + + + align:start position:0% +replace this capacitor with just a fixed +voltage + + align:start position:0% +voltage + + + align:start position:0% +voltage +VC and in this other state he's also + + align:start position:0% +VC and in this other state he's also + + + align:start position:0% +VC and in this other state he's also +going to be a fixed voltage VC and the + + align:start position:0% +going to be a fixed voltage VC and the + + + align:start position:0% +going to be a fixed voltage VC and the +only thing I need is the net charge that + + align:start position:0% +only thing I need is the net charge that + + + align:start position:0% +only thing I need is the net charge that +goes into VC over a cycle to be zero + + align:start position:0% +goes into VC over a cycle to be zero + + + align:start position:0% +goes into VC over a cycle to be zero +right so how much charge do I transfer + + align:start position:0% +right so how much charge do I transfer + + + align:start position:0% +right so how much charge do I transfer +in state + + align:start position:0% + + + + align:start position:0% + +one okay and I'm going to do FSL with + + align:start position:0% +one okay and I'm going to do FSL with + + + align:start position:0% +one okay and I'm going to do FSL with +50% Duty + + align:start position:0% + + + + align:start position:0% + +ratio in other words I'm going to assume + + align:start position:0% +ratio in other words I'm going to assume + + + align:start position:0% +ratio in other words I'm going to assume +that in state one I spend half a period + + align:start position:0% +that in state one I spend half a period + + + align:start position:0% +that in state one I spend half a period +and state two I'm going to spend half a + + align:start position:0% +and state two I'm going to spend half a + + + align:start position:0% +and state two I'm going to spend half a +period um because in the FSL the fast + + align:start position:0% +period um because in the FSL the fast + + + align:start position:0% +period um because in the FSL the fast +switching limit how much time I spend in + + align:start position:0% +switching limit how much time I spend in + + + align:start position:0% +switching limit how much time I spend in +the two and States matters but let's + + align:start position:0% +the two and States matters but let's + + + align:start position:0% +the two and States matters but let's +just assume I'm going to spend half in + + align:start position:0% +just assume I'm going to spend half in + + + align:start position:0% +just assume I'm going to spend half in +each state for purposes of this analysis + + align:start position:0% +each state for purposes of this analysis + + + align:start position:0% +each state for purposes of this analysis +so in state one what do I get for Delta + + align:start position:0% +so in state one what do I get for Delta + + + align:start position:0% +so in state one what do I get for Delta +qc1 okay well Delta + + align:start position:0% + + + + align:start position:0% + +qc1 is going to be what I'm going to say + + align:start position:0% +qc1 is going to be what I'm going to say + + + align:start position:0% +qc1 is going to be what I'm going to say +all right if he's a constant voltage I'm + + align:start position:0% +all right if he's a constant voltage I'm + + + align:start position:0% +all right if he's a constant voltage I'm +going to get a current that's going to + + align:start position:0% +going to get a current that's going to + + + align:start position:0% +going to get a current that's going to +be V in minus v c minus V out divid 2 + + align:start position:0% +be V in minus v c minus V out divid 2 + + + align:start position:0% +be V in minus v c minus V out divid 2 +our switch right that's the current + + align:start position:0% +our switch right that's the current + + + align:start position:0% +our switch right that's the current +current in state one so that's going to + + align:start position:0% +current in state one so that's going to + + + align:start position:0% +current in state one so that's going to +be uh + + align:start position:0% +be uh + + + align:start position:0% +be uh +VN minus VC minus V + + align:start position:0% +VN minus VC minus V + + + align:start position:0% +VN minus VC minus V +out divided by 2 R + + align:start position:0% +out divided by 2 R + + + align:start position:0% +out divided by 2 R +switch and that's going to happen for + + align:start position:0% +switch and that's going to happen for + + + align:start position:0% +switch and that's going to happen for +how long that's going to happen + + align:start position:0% +how long that's going to happen + + + align:start position:0% +how long that's going to happen +Fort or I could write that as 1 over 2f + + align:start position:0% +Fort or I could write that as 1 over 2f + + + align:start position:0% +Fort or I could write that as 1 over 2f +switch right this is times half a + + align:start position:0% +switch right this is times half a + + + align:start position:0% +switch right this is times half a +period okay what is Delta Q + + align:start position:0% +period okay what is Delta Q + + + align:start position:0% +period okay what is Delta Q +in1 look like that's just going to be + + align:start position:0% +in1 look like that's just going to be + + + align:start position:0% +in1 look like that's just going to be +minus Delta + + align:start position:0% + + + + align:start position:0% + +qc1 and what's Delta qn 2 look like + + align:start position:0% +qc1 and what's Delta qn 2 look like + + + align:start position:0% +qc1 and what's Delta qn 2 look like +that's just going to be equal to uh + + align:start position:0% +that's just going to be equal to uh + + + align:start position:0% +that's just going to be equal to uh +Delta + + align:start position:0% +Delta + + + align:start position:0% +Delta +qc1 right other words all I'm saying is + + align:start position:0% +qc1 right other words all I'm saying is + + + align:start position:0% +qc1 right other words all I'm saying is +that here the input got the negative of + + align:start position:0% +that here the input got the negative of + + + align:start position:0% +that here the input got the negative of +the charge of the capacitor and the + + align:start position:0% +the charge of the capacitor and the + + + align:start position:0% +the charge of the capacitor and the +output got the charge that went through + + align:start position:0% +output got the charge that went through + + + align:start position:0% +output got the charge that went through +the + + align:start position:0% +the + + + align:start position:0% +the +capacitor make sense to everybody + + align:start position:0% +capacitor make sense to everybody + + + align:start position:0% +capacitor make sense to everybody +if I if I do this for state + + align:start position:0% +if I if I do this for state + + + align:start position:0% +if I if I do this for state +two okay state + + align:start position:0% + + + + align:start position:0% + +two right what I'm going to get is Delta + + align:start position:0% +two right what I'm going to get is Delta + + + align:start position:0% +two right what I'm going to get is Delta +QC 2 is simply going to be what it's + + align:start position:0% +QC 2 is simply going to be what it's + + + align:start position:0% +QC 2 is simply going to be what it's +going to be + + align:start position:0% +going to be + + + align:start position:0% +going to be +um V out minus VC over 2R switch right + + align:start position:0% +um V out minus VC over 2R switch right + + + align:start position:0% +um V out minus VC over 2R switch right +or it's going to be be + + align:start position:0% +or it's going to be be + + + align:start position:0% +or it's going to be be +um V out minus VC over two our switch + + align:start position:0% +um V out minus VC over two our switch + + + align:start position:0% +um V out minus VC over two our switch +we're going to it's going to be + + align:start position:0% +we're going to it's going to be + + + align:start position:0% +we're going to it's going to be +minus + + align:start position:0% +minus + + + align:start position:0% +minus +uh VC minus V out over 2 R switch times + + align:start position:0% +uh VC minus V out over 2 R switch times + + + align:start position:0% +uh VC minus V out over 2 R switch times +1 over 2f + + align:start position:0% +1 over 2f + + + align:start position:0% +1 over 2f +switch right Delta + + align:start position:0% +switch right Delta + + + align:start position:0% +switch right Delta +Q in two is going to be zero and Delta Q + + align:start position:0% +Q in two is going to be zero and Delta Q + + + align:start position:0% +Q in two is going to be zero and Delta Q +out2 is going to be equal to the + + align:start position:0% +out2 is going to be equal to the + + + align:start position:0% +out2 is going to be equal to the +negative of this which is going to be + + align:start position:0% +negative of this which is going to be + + + align:start position:0% +negative of this which is going to be +minus Delta QC 2 does that make sense + + align:start position:0% +minus Delta QC 2 does that make sense + + + align:start position:0% +minus Delta QC 2 does that make sense +everybody yeah + + align:start position:0% + + + + align:start position:0% + +em yes + + align:start position:0% + + + + align:start position:0% + +uh that's what happens when I Rush thank + + align:start position:0% +uh that's what happens when I Rush thank + + + align:start position:0% +uh that's what happens when I Rush thank +you all + + align:start position:0% +you all + + + align:start position:0% +you all +right um what constraint do I get off of + + align:start position:0% +right um what constraint do I get off of + + + align:start position:0% +right um what constraint do I get off of +this well what I need is Delta QC of 1 + + align:start position:0% +this well what I need is Delta QC of 1 + + + align:start position:0% +this well what I need is Delta QC of 1 +plus Delta QC of 2 have to add up to + + align:start position:0% +plus Delta QC of 2 have to add up to + + + align:start position:0% +plus Delta QC of 2 have to add up to +zero right I mean that's a that's a + + align:start position:0% +zero right I mean that's a that's a + + + align:start position:0% +zero right I mean that's a that's a +constraint for periodic steady state + + align:start position:0% +constraint for periodic steady state + + + align:start position:0% +constraint for periodic steady state +right so what I get is for + + align:start position:0% + + + + align:start position:0% + +PSS um what I get is Delta Delta QC of 1 + + align:start position:0% +PSS um what I get is Delta Delta QC of 1 + + + align:start position:0% +PSS um what I get is Delta Delta QC of 1 +plus Delta QC for 2 is equal to zero + + align:start position:0% +plus Delta QC for 2 is equal to zero + + + align:start position:0% +plus Delta QC for 2 is equal to zero +which gives me um I can ignore the one + + align:start position:0% +which gives me um I can ignore the one + + + align:start position:0% +which gives me um I can ignore the one +over4 F switch R switch that gives me V + + align:start position:0% +over4 F switch R switch that gives me V + + + align:start position:0% +over4 F switch R switch that gives me V +in minus VC minus V + + align:start position:0% + + + + align:start position:0% + +out + + align:start position:0% +out + + + align:start position:0% +out +plus + + align:start position:0% +plus + + + align:start position:0% +plus +um V out minus + + align:start position:0% + + + + align:start position:0% + +VC plus v out minus VC is equal to + + align:start position:0% +VC plus v out minus VC is equal to + + + align:start position:0% +VC plus v out minus VC is equal to +zero okay and what this gives me is that + + align:start position:0% +zero okay and what this gives me is that + + + align:start position:0% +zero okay and what this gives me is that +um VC is going to be half + + align:start position:0% + + + + align:start position:0% + +VN so in periodic steady state I'm going + + align:start position:0% +VN so in periodic steady state I'm going + + + align:start position:0% +VN so in periodic steady state I'm going +to be charging and discharging the + + align:start position:0% +to be charging and discharging the + + + align:start position:0% +to be charging and discharging the +capacitor but he's going to sit in an + + align:start position:0% +capacitor but he's going to sit in an + + + align:start position:0% +capacitor but he's going to sit in an +average value of half + + align:start position:0% +average value of half + + + align:start position:0% +average value of half +VM okay I can then go and plug this + + align:start position:0% +VM okay I can then go and plug this + + + align:start position:0% +VM okay I can then go and plug this +value back in and I'm kind of running + + align:start position:0% +value back in and I'm kind of running + + + align:start position:0% +value back in and I'm kind of running +out of time here I can go plug this back + + align:start position:0% +out of time here I can go plug this back + + + align:start position:0% +out of time here I can go plug this back +in and find Q out one and Q in one right + + align:start position:0% +in and find Q out one and Q in one right + + + align:start position:0% +in and find Q out one and Q in one right +I can do the same game I do over here + + align:start position:0% +I can do the same game I do over here + + + align:start position:0% +I can do the same game I do over here +and um if you do that + + align:start position:0% +and um if you do that + + + align:start position:0% +and um if you do that +calculation it's it's pretty easy I can + + align:start position:0% +calculation it's it's pretty easy I can + + + align:start position:0% +calculation it's it's pretty easy I can +calculate I out as being the sum of q1 Q + + align:start position:0% +calculate I out as being the sum of q1 Q + + + align:start position:0% +calculate I out as being the sum of q1 Q +in and Q out and what I get is V + + align:start position:0% +in and Q out and what I get is V + + + align:start position:0% +in and Q out and what I get is V +out is equal to 12 + + align:start position:0% +out is equal to 12 + + + align:start position:0% +out is equal to 12 +VN + + align:start position:0% +VN + + + align:start position:0% +VN +minus uh 2 R switch I + + align:start position:0% + + + + align:start position:0% + +out okay so it's of the exact same + + align:start position:0% +out okay so it's of the exact same + + + align:start position:0% +out okay so it's of the exact same +format + + align:start position:0% +format + + + align:start position:0% +format +that I had up + + align:start position:0% +that I had up + + + align:start position:0% +that I had up +here so + + align:start position:0% +here so + + + align:start position:0% +here so +here I get this in the + + align:start position:0% + + + + align:start position:0% + +SSL and in the + + align:start position:0% + + + + align:start position:0% + +FSL in the + + align:start position:0% +FSL in the + + + align:start position:0% +FSL in the +FSL maybe I should use a different + + align:start position:0% +FSL maybe I should use a different + + + align:start position:0% +FSL maybe I should use a different +color in the + + align:start position:0% + + + + align:start position:0% + +FSL + + align:start position:0% +FSL + + + align:start position:0% +FSL +req is simply equal to 2R switch + + align:start position:0% +req is simply equal to 2R switch + + + align:start position:0% +req is simply equal to 2R switch +okay well that actually kind of feels + + align:start position:0% +okay well that actually kind of feels + + + align:start position:0% +okay well that actually kind of feels +good in some sense because you think + + align:start position:0% +good in some sense because you think + + + align:start position:0% +good in some sense because you think +about it in either of these two states + + align:start position:0% +about it in either of these two states + + + align:start position:0% +about it in either of these two states +I'm always dumping + + align:start position:0% +I'm always dumping + + + align:start position:0% +I'm always dumping +current through two + + align:start position:0% +current through two + + + align:start position:0% +current through two +switches right so so you know half the + + align:start position:0% +switches right so so you know half the + + + align:start position:0% +switches right so so you know half the +time I'm doing in this configuration + + align:start position:0% +time I'm doing in this configuration + + + align:start position:0% +time I'm doing in this configuration +half the time in that configuration but + + align:start position:0% +half the time in that configuration but + + + align:start position:0% +half the time in that configuration but +if I think of the capacitor current as + + align:start position:0% +if I think of the capacitor current as + + + align:start position:0% +if I think of the capacitor current as +being sort of a plus and minus Square + + align:start position:0% +being sort of a plus and minus Square + + + align:start position:0% +being sort of a plus and minus Square +wave of + + align:start position:0% +wave of + + + align:start position:0% +wave of +current uh the input current is constant + + align:start position:0% +current uh the input current is constant + + + align:start position:0% +current uh the input current is constant +coming here and the output currents I'm + + align:start position:0% +coming here and the output currents I'm + + + align:start position:0% +coming here and the output currents I'm +sorry the input current's a a pulse + + align:start position:0% +sorry the input current's a a pulse + + + align:start position:0% +sorry the input current's a a pulse +Square the output current is kind of + + align:start position:0% +Square the output current is kind of + + + align:start position:0% +Square the output current is kind of +constant um but the point is I'm always + + align:start position:0% +constant um but the point is I'm always + + + align:start position:0% +constant um but the point is I'm always +putting my charging and discharging + + align:start position:0% +putting my charging and discharging + + + align:start position:0% +putting my charging and discharging +current through two switch resistances + + align:start position:0% +current through two switch resistances + + + align:start position:0% +current through two switch resistances +so it's not maybe surprising that I get + + align:start position:0% +so it's not maybe surprising that I get + + + align:start position:0% +so it's not maybe surprising that I get +down to this equivalent resistance being + + align:start position:0% +down to this equivalent resistance being + + + align:start position:0% +down to this equivalent resistance being +two switch + + align:start position:0% +two switch + + + align:start position:0% +two switch +resistances okay so what happens in the + + align:start position:0% +resistances okay so what happens in the + + + align:start position:0% +resistances okay so what happens in the +real world is if I have a switch + + align:start position:0% +real world is if I have a switch + + + align:start position:0% +real world is if I have a switch +capacitor converter and I say I'm going + + align:start position:0% +capacitor converter and I say I'm going + + + align:start position:0% +capacitor converter and I say I'm going +to have this model for Its Behavior + + align:start position:0% +to have this model for Its Behavior + + + align:start position:0% +to have this model for Its Behavior +okay all I'm going to + + align:start position:0% +okay all I'm going to + + + align:start position:0% +okay all I'm going to +get is if I plotted our equivalent on a + + align:start position:0% +get is if I plotted our equivalent on a + + + align:start position:0% +get is if I plotted our equivalent on a +log + + align:start position:0% +log + + + align:start position:0% +log +scale versus switching frequency on a + + align:start position:0% +scale versus switching frequency on a + + + align:start position:0% +scale versus switching frequency on a +log scale what I'm going to get is + + align:start position:0% +log scale what I'm going to get is + + + align:start position:0% +log scale what I'm going to get is +something that falls + + align:start position:0% +something that falls + + + align:start position:0% +something that falls +linearly this is 1 over4 CF + + align:start position:0% +linearly this is 1 over4 CF + + + align:start position:0% +linearly this is 1 over4 CF +switch okay and then he's going to have + + align:start position:0% +switch okay and then he's going to have + + + align:start position:0% +switch okay and then he's going to have +some minimum + + align:start position:0% +some minimum + + + align:start position:0% +some minimum +value which is to our switch + + align:start position:0% +value which is to our switch + + + align:start position:0% +value which is to our switch +right and the actual value you're going + + align:start position:0% +right and the actual value you're going + + + align:start position:0% +right and the actual value you're going +to get is going to you know sort of do + + align:start position:0% +to get is going to you know sort of do + + + align:start position:0% +to get is going to you know sort of do +something like + + align:start position:0% +something like + + + align:start position:0% +something like +this all right so you kind of there's + + align:start position:0% +this all right so you kind of there's + + + align:start position:0% +this all right so you kind of there's +kind of some limiting efficiency you can + + align:start position:0% +kind of some limiting efficiency you can + + + align:start position:0% +kind of some limiting efficiency you can +get to well if I'm charging through two + + align:start position:0% +get to well if I'm charging through two + + + align:start position:0% +get to well if I'm charging through two +switches all the time I got to eat the + + align:start position:0% +switches all the time I got to eat the + + + align:start position:0% +switches all the time I got to eat the +loss of the on-state loss of those + + align:start position:0% +loss of the on-state loss of those + + + align:start position:0% +loss of the on-state loss of those +switches right I mean I can't have 100% + + align:start position:0% +switches right I mean I can't have 100% + + + align:start position:0% +switches right I mean I can't have 100% +efficiency but you know if I'm using 10 + + align:start position:0% +efficiency but you know if I'm using 10 + + + align:start position:0% +efficiency but you know if I'm using 10 +mli ohm switches maybe that's pretty + + align:start position:0% +mli ohm switches maybe that's pretty + + + align:start position:0% +mli ohm switches maybe that's pretty +damn low right so + + align:start position:0% +damn low right so + + + align:start position:0% +damn low right so +um essentially what I would tend to do + + align:start position:0% +um essentially what I would tend to do + + + align:start position:0% +um essentially what I would tend to do +is keep turning up the switching + + align:start position:0% +is keep turning up the switching + + + align:start position:0% +is keep turning up the switching +frequency until I get down to this + + align:start position:0% +frequency until I get down to this + + + align:start position:0% +frequency until I get down to this +regime where turning it up anymore + + align:start position:0% +regime where turning it up anymore + + + align:start position:0% +regime where turning it up anymore +doesn't reduce my output resistance + + align:start position:0% +doesn't reduce my output resistance + + + align:start position:0% +doesn't reduce my output resistance +because at that point there are other + + align:start position:0% +because at that point there are other + + + align:start position:0% +because at that point there are other +losses like Gate Drive losses and stuff + + align:start position:0% +losses like Gate Drive losses and stuff + + + align:start position:0% +losses like Gate Drive losses and stuff +which get worse with frequency so I + + align:start position:0% +which get worse with frequency so I + + + align:start position:0% +which get worse with frequency so I +ought to just go high enough that I can + + align:start position:0% +ought to just go high enough that I can + + + align:start position:0% +ought to just go high enough that I can +get to very high efficiencies and the + + align:start position:0% +get to very high efficiencies and the + + + align:start position:0% +get to very high efficiencies and the +result of this is if what I want is a + + align:start position:0% +result of this is if what I want is a + + + align:start position:0% +result of this is if what I want is a +fixed conversion ratio close to this I + + align:start position:0% +fixed conversion ratio close to this I + + + align:start position:0% +fixed conversion ratio close to this I +can get extraordinarily High + + align:start position:0% +can get extraordinarily High + + + align:start position:0% +can get extraordinarily High +efficiencies and power + + align:start position:0% +efficiencies and power + + + align:start position:0% +efficiencies and power +densities if I deviate the voltage + + align:start position:0% +densities if I deviate the voltage + + + align:start position:0% +densities if I deviate the voltage +conversion ratio away from that then the + + align:start position:0% +conversion ratio away from that then the + + + align:start position:0% +conversion ratio away from that then the +efficiencies start to droop but for what + + align:start position:0% +efficiencies start to droop but for what + + + align:start position:0% +efficiencies start to droop but for what +they're good at switch capacitor + + align:start position:0% +they're good at switch capacitor + + + align:start position:0% +they're good at switch capacitor +converters are very hard to beat and if + + align:start position:0% +converters are very hard to beat and if + + + align:start position:0% +converters are very hard to beat and if +I was to come back and analyze any other + + align:start position:0% +I was to come back and analyze any other + + + align:start position:0% +I was to come back and analyze any other +switch capacitor converter it's the same + + align:start position:0% +switch capacitor converter it's the same + + + align:start position:0% +switch capacitor converter it's the same +deal it's some charge transfer analysis + + align:start position:0% +deal it's some charge transfer analysis + + + align:start position:0% +deal it's some charge transfer analysis +through the different capacitors and I + + align:start position:0% +through the different capacitors and I + + + align:start position:0% +through the different capacitors and I +use charge balance and you can work that + + align:start position:0% +use charge balance and you can work that + + + align:start position:0% +use charge balance and you can work that +out to being a current conversion ratio + + align:start position:0% +out to being a current conversion ratio + + + align:start position:0% +out to being a current conversion ratio +and then some equivalent resistance with + + align:start position:0% +and then some equivalent resistance with + + + align:start position:0% +and then some equivalent resistance with +a slow switching limit and a fast + + align:start position:0% +a slow switching limit and a fast + + + align:start position:0% +a slow switching limit and a fast +switching + + align:start position:0% + + + + align:start position:0% + +we'll take this up again next class but + + align:start position:0% +we'll take this up again next class but + + + align:start position:0% +we'll take this up again next class but +are there any final + + align:start position:0% +are there any final + + + align:start position:0% +are there any final +questions yeah now that you're switching + + align:start position:0% +questions yeah now that you're switching + + + align:start position:0% +questions yeah now that you're switching +quickly can the duty ratio change the + + align:start position:0% +quickly can the duty ratio change the + + + align:start position:0% +quickly can the duty ratio change the +conversion + + align:start position:0% +conversion + + + align:start position:0% +conversion +ratio uh well the yes but only through + + align:start position:0% +ratio uh well the yes but only through + + + align:start position:0% +ratio uh well the yes but only through +the action of essentially what this + + align:start position:0% +the action of essentially what this + + + align:start position:0% +the action of essentially what this +resistance is so you can make the you + + align:start position:0% +resistance is so you can make the you + + + align:start position:0% +resistance is so you can make the you +know there's a duty ratio for any given + + align:start position:0% +know there's a duty ratio for any given + + + align:start position:0% +know there's a duty ratio for any given +converter there's a duty ratio that will + + align:start position:0% +converter there's a duty ratio that will + + + align:start position:0% +converter there's a duty ratio that will +sort of give you the lowest output + + align:start position:0% +sort of give you the lowest output + + + align:start position:0% +sort of give you the lowest output +resistance even in slow switching limit + + align:start position:0% +resistance even in slow switching limit + + + align:start position:0% +resistance even in slow switching limit +you can change the conversion ratio but + + align:start position:0% +you can change the conversion ratio but + + + align:start position:0% +you can change the conversion ratio but +you're doing it through a resistive drop + + align:start position:0% +you're doing it through a resistive drop + + + align:start position:0% +you're doing it through a resistive drop +it's sort of like you have an ideal + + align:start position:0% +it's sort of like you have an ideal + + + align:start position:0% +it's sort of like you have an ideal +Transformer and then a linear regulator + + align:start position:0% +Transformer and then a linear regulator + + + align:start position:0% +Transformer and then a linear regulator +kind of thing so you can always use + + align:start position:0% +kind of thing so you can always use + + + align:start position:0% +kind of thing so you can always use +switching frequency or D and in fast + + align:start position:0% +switching frequency or D and in fast + + + align:start position:0% +switching frequency or D and in fast +switching limit Duty ratio to change the + + align:start position:0% +switching limit Duty ratio to change the + + + align:start position:0% +switching limit Duty ratio to change the +conversion ratio but not in a perfectly + + align:start position:0% +conversion ratio but not in a perfectly + + + align:start position:0% +conversion ratio but not in a perfectly +efficient + + align:start position:0% +efficient + + + align:start position:0% +efficient +sense the voltage conversion ratio all + + align:start position:0% +sense the voltage conversion ratio all + + + align:start position:0% +sense the voltage conversion ratio all +right great we'll pick this up next + + align:start position:0% +right great we'll pick this up next + + + align:start position:0% +right great we'll pick this up next +class \ No newline at end of file diff --git a/Cn5K8R8cEiI.txt b/Cn5K8R8cEiI.txt new file mode 100644 index 0000000000000000000000000000000000000000..18cbbdc95e6978329fb903c24c923e829f7e959a --- /dev/null +++ b/Cn5K8R8cEiI.txt @@ -0,0 +1,14059 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit MIT opencourseware + + align:start position:0% +of MIT courses visit MIT opencourseware + + + align:start position:0% +of MIT courses visit MIT opencourseware +at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu okay so today what we want + + align:start position:0% +ocw.mit.edu okay so today what we want + + + align:start position:0% +ocw.mit.edu okay so today what we want +to do is uh we want to talk about uh + + align:start position:0% +to do is uh we want to talk about uh + + + align:start position:0% +to do is uh we want to talk about uh +kind of two related topics so the first + + align:start position:0% +kind of two related topics so the first + + + align:start position:0% +kind of two related topics so the first +is going to be this question of uh the + + align:start position:0% +is going to be this question of uh the + + + align:start position:0% +is going to be this question of uh the +evolution of variance and how to model + + align:start position:0% +evolution of variance and how to model + + + align:start position:0% +evolution of variance and how to model +host parasite and actions more broadly + + align:start position:0% +host parasite and actions more broadly + + + align:start position:0% +host parasite and actions more broadly +all right that's kind of modeled on + + align:start position:0% +all right that's kind of modeled on + + + align:start position:0% +all right that's kind of modeled on +chapter 11 of Martin's book we'll focus + + align:start position:0% +chapter 11 of Martin's book we'll focus + + + align:start position:0% +chapter 11 of Martin's book we'll focus +on the first half of it for the + + align:start position:0% +on the first half of it for the + + + align:start position:0% +on the first half of it for the +discussions today right this is in the + + align:start position:0% +discussions today right this is in the + + + align:start position:0% +discussions today right this is in the +context of when a given host can only + + align:start position:0% +context of when a given host can only + + + align:start position:0% +context of when a given host can only +have one uh one strain of the parasite + + align:start position:0% +have one uh one strain of the parasite + + + align:start position:0% +have one uh one strain of the parasite +or virus or whatnot uh inside um inside + + align:start position:0% +or virus or whatnot uh inside um inside + + + align:start position:0% +or virus or whatnot uh inside um inside +that body okay the the model presented + + align:start position:0% +that body okay the the model presented + + + align:start position:0% +that body okay the the model presented +in Martin's book is um is very similar + + align:start position:0% +in Martin's book is um is very similar + + + align:start position:0% +in Martin's book is um is very similar +to kind of classic models in + + align:start position:0% +to kind of classic models in + + + align:start position:0% +to kind of classic models in +epidemiology which are the so-called sir + + align:start position:0% +epidemiology which are the so-called sir + + + align:start position:0% +epidemiology which are the so-called sir +type models uh where you divide up the + + align:start position:0% +type models uh where you divide up the + + + align:start position:0% +type models uh where you divide up the +host population into whether the they + + align:start position:0% +host population into whether the they + + + align:start position:0% +host population into whether the they +are uh sensitive I.E non-infected + + align:start position:0% +are uh sensitive I.E non-infected + + + align:start position:0% +are uh sensitive I.E non-infected +infected or resistant okay and then + + align:start position:0% +infected or resistant okay and then + + + align:start position:0% +infected or resistant okay and then +we'll we'll kind of draw the parallels + + align:start position:0% +we'll we'll kind of draw the parallels + + + align:start position:0% +we'll we'll kind of draw the parallels +of how we get from the model that we + + align:start position:0% +of how we get from the model that we + + + align:start position:0% +of how we get from the model that we +talked about in Martin's book or that + + align:start position:0% +talked about in Martin's book or that + + + align:start position:0% +talked about in Martin's book or that +you read about in Martin's book to the + + align:start position:0% +you read about in Martin's book to the + + + align:start position:0% +you read about in Martin's book to the +classic sir models okay but in both of + + align:start position:0% +classic sir models okay but in both of + + + align:start position:0% +classic sir models okay but in both of +these cases the the fundamental + + align:start position:0% +these cases the the fundamental + + + align:start position:0% +these cases the the fundamental +parameter that drives these things is + + align:start position:0% +parameter that drives these things is + + + align:start position:0% +parameter that drives these things is +this R not parameter it tells us about + + align:start position:0% +this R not parameter it tells us about + + + align:start position:0% +this R not parameter it tells us about +uh the expected number of individuals + + align:start position:0% +uh the expected number of individuals + + + align:start position:0% +uh the expected number of individuals +that will be of new cases that will + + align:start position:0% +that will be of new cases that will + + + align:start position:0% +that will be of new cases that will +result when you introduce one infected + + align:start position:0% +result when you introduce one infected + + + align:start position:0% +result when you introduce one infected +member into the + + align:start position:0% +member into the + + + align:start position:0% +member into the +population + + align:start position:0% +population + + + align:start position:0% +population +talk uh only a little bit but uh I would + + align:start position:0% +talk uh only a little bit but uh I would + + + align:start position:0% +talk uh only a little bit but uh I would +say depending on time if if you're + + align:start position:0% +say depending on time if if you're + + + align:start position:0% +say depending on time if if you're +interested in in the super infection + + align:start position:0% +interested in in the super infection + + + align:start position:0% +interested in in the super infection +discussion more uh we can talk about it + + align:start position:0% +discussion more uh we can talk about it + + + align:start position:0% +discussion more uh we can talk about it +after class + + align:start position:0% + + + + align:start position:0% + +maybe right okay so for the second half + + align:start position:0% +maybe right okay so for the second half + + + align:start position:0% +maybe right okay so for the second half +of the class what we're going to do + + align:start position:0% +of the class what we're going to do + + + align:start position:0% +of the class what we're going to do +though is we're going to talk about the + + align:start position:0% +though is we're going to talk about the + + + align:start position:0% +though is we're going to talk about the +possible evolutionary benefit benefits + + align:start position:0% +possible evolutionary benefit benefits + + + align:start position:0% +possible evolutionary benefit benefits +of sex right and in particular we'll + + align:start position:0% +of sex right and in particular we'll + + + align:start position:0% +of sex right and in particular we'll +we'll talk about this hypothesis which + + align:start position:0% +we'll talk about this hypothesis which + + + align:start position:0% +we'll talk about this hypothesis which +is one of the reigning hypothesis for + + align:start position:0% +is one of the reigning hypothesis for + + + align:start position:0% +is one of the reigning hypothesis for +why it might be that sax is as + + align:start position:0% +why it might be that sax is as + + + align:start position:0% +why it might be that sax is as +widespread as it is which is this uh the + + align:start position:0% +widespread as it is which is this uh the + + + align:start position:0% +widespread as it is which is this uh the +Red Queen hypothesis right from uh from + + align:start position:0% +Red Queen hypothesis right from uh from + + + align:start position:0% +Red Queen hypothesis right from uh from +L Carol's novel is kind of uh and and + + align:start position:0% +L Carol's novel is kind of uh and and + + + align:start position:0% +L Carol's novel is kind of uh and and +and we're going to discuss this paper + + align:start position:0% +and we're going to discuss this paper + + + align:start position:0% +and we're going to discuss this paper +that you guys read about uh running with + + align:start position:0% +that you guys read about uh running with + + + align:start position:0% +that you guys read about uh running with +the Red Queen which I think is kind of a + + align:start position:0% +the Red Queen which I think is kind of a + + + align:start position:0% +the Red Queen which I think is kind of a +nice has a nice discussion of this + + align:start position:0% +nice has a nice discussion of this + + + align:start position:0% +nice has a nice discussion of this +debate and then some nice experiments + + align:start position:0% +debate and then some nice experiments + + + align:start position:0% +debate and then some nice experiments +looking at experimental coevolution + + align:start position:0% +looking at experimental coevolution + + + align:start position:0% +looking at experimental coevolution +between uh seelan worm and it's + + align:start position:0% +between uh seelan worm and it's + + + align:start position:0% +between uh seelan worm and it's +infecting parasite which is a sera + + align:start position:0% +infecting parasite which is a sera + + + align:start position:0% +infecting parasite which is a sera +bacterium + + align:start position:0% +bacterium + + + align:start position:0% +bacterium +any any questions before we get + + align:start position:0% + + + + align:start position:0% + +going okay what I want to do is is start + + align:start position:0% +going okay what I want to do is is start + + + align:start position:0% +going okay what I want to do is is start +by discussing + + align:start position:0% +by discussing + + + align:start position:0% +by discussing +uh this model in Martin's uh in Martin's + + align:start position:0% +uh this model in Martin's uh in Martin's + + + align:start position:0% +uh this model in Martin's uh in Martin's +book but also a little bit there's a + + align:start position:0% +book but also a little bit there's a + + + align:start position:0% +book but also a little bit there's a +little bit of this pH philosophical + + align:start position:0% +little bit of this pH philosophical + + + align:start position:0% +little bit of this pH philosophical +question you know anytime that you have + + align:start position:0% +question you know anytime that you have + + + align:start position:0% +question you know anytime that you have +uh you have you have modeling you you + + align:start position:0% +uh you have you have modeling you you + + + align:start position:0% +uh you have you have modeling you you +always have to make decisions about uh + + align:start position:0% +always have to make decisions about uh + + + align:start position:0% +always have to make decisions about uh +which of the details you want to try to + + align:start position:0% +which of the details you want to try to + + + align:start position:0% +which of the details you want to try to +model and which of the details you do + + align:start position:0% +model and which of the details you do + + + align:start position:0% +model and which of the details you do +not want to model and uh depending upon + + align:start position:0% +not want to model and uh depending upon + + + align:start position:0% +not want to model and uh depending upon +the the situation it may be that some + + align:start position:0% +the the situation it may be that some + + + align:start position:0% +the the situation it may be that some +assumptions are more or less appropriate + + align:start position:0% +assumptions are more or less appropriate + + + align:start position:0% +assumptions are more or less appropriate +than others right now in the model that + + align:start position:0% +than others right now in the model that + + + align:start position:0% +than others right now in the model that +uh that Martin wrote down uh you can uh + + align:start position:0% +uh that Martin wrote down uh you can uh + + + align:start position:0% +uh that Martin wrote down uh you can uh +well okay well we'll try to figure out + + align:start position:0% +well okay well we'll try to figure out + + + align:start position:0% +well okay well we'll try to figure out +what the assumptions are here okay so we + + align:start position:0% +what the assumptions are here okay so we + + + align:start position:0% +what the assumptions are here okay so we +have uh we have these what you might + + align:start position:0% +have uh we have these what you might + + + align:start position:0% +have uh we have these what you might +think of as some sensitive individuals + + align:start position:0% +think of as some sensitive individuals + + + align:start position:0% +think of as some sensitive individuals +uh plus the infected + + align:start position:0% +uh plus the infected + + + align:start position:0% +uh plus the infected +individuals are going to interact and + + align:start position:0% +individuals are going to interact and + + + align:start position:0% +individuals are going to interact and +some rate beta so this is how the + + align:start position:0% +some rate beta so this is how the + + + align:start position:0% +some rate beta so this is how the +sensitive become infected and it results + + align:start position:0% +sensitive become infected and it results + + + align:start position:0% +sensitive become infected and it results +in now two infected + + align:start position:0% +in now two infected + + + align:start position:0% +in now two infected +individuals okay now of course each of + + align:start position:0% +individuals okay now of course each of + + + align:start position:0% +individuals okay now of course each of +these individuals will uh say have some + + align:start position:0% +these individuals will uh say have some + + + align:start position:0% +these individuals will uh say have some +lifespan or die at some rate right so + + align:start position:0% +lifespan or die at some rate right so + + + align:start position:0% +lifespan or die at some rate right so +this we're going to say this die the + + align:start position:0% +this we're going to say this die the + + + align:start position:0% +this we're going to say this die the +sensitive or uninfected in individuals + + align:start position:0% +sensitive or uninfected in individuals + + + align:start position:0% +sensitive or uninfected in individuals +diet rate U whereas infected individuals + + align:start position:0% +diet rate U whereas infected individuals + + + align:start position:0% +diet rate U whereas infected individuals +uh there's uh an increase in the death + + align:start position:0% +uh there's uh an increase in the death + + + align:start position:0% +uh there's uh an increase in the death +rate described by some virulence V okay + + align:start position:0% + + + + align:start position:0% + +okay now uh the model as written what's + + align:start position:0% +okay now uh the model as written what's + + + align:start position:0% +okay now uh the model as written what's +going to be the fate of the + + align:start position:0% + + + + align:start position:0% + +population yeah yeah everyone's gonna + + align:start position:0% +population yeah yeah everyone's gonna + + + align:start position:0% +population yeah yeah everyone's gonna +die right and and that's even true in + + align:start position:0% +die right and and that's even true in + + + align:start position:0% +die right and and that's even true in +the ABS it's not even that the + + align:start position:0% +the ABS it's not even that the + + + align:start position:0% +the ABS it's not even that the +population is dying as a result of the + + align:start position:0% +population is dying as a result of the + + + align:start position:0% +population is dying as a result of the +infection right because even in the + + align:start position:0% +infection right because even in the + + + align:start position:0% +infection right because even in the +absence of any infected + + align:start position:0% +absence of any infected + + + align:start position:0% +absence of any infected +individuals you know you just have + + align:start position:0% +individuals you know you just have + + + align:start position:0% +individuals you know you just have +people dying right so you need to have + + align:start position:0% +people dying right so you need to have + + + align:start position:0% +people dying right so you need to have +some way of keeping the population going + + align:start position:0% +some way of keeping the population going + + + align:start position:0% +some way of keeping the population going +so that you can study it perhaps and + + align:start position:0% +so that you can study it perhaps and + + + align:start position:0% +so that you can study it perhaps and +what what we're going to assume is that + + align:start position:0% +what what we're going to assume is that + + + align:start position:0% +what what we're going to assume is that +that sensitive individuals or uninfected + + align:start position:0% +that sensitive individuals or uninfected + + + align:start position:0% +that sensitive individuals or uninfected +individuals will enter the population + + align:start position:0% +individuals will enter the population + + + align:start position:0% +individuals will enter the population +just at some rate + + align:start position:0% + + + + align:start position:0% + +K right now and okay right so in terms + + align:start position:0% +K right now and okay right so in terms + + + align:start position:0% +K right now and okay right so in terms +of in terms of the philosophical + + align:start position:0% +of in terms of the philosophical + + + align:start position:0% +of in terms of the philosophical +question uh that in the beginning of of + + align:start position:0% +question uh that in the beginning of of + + + align:start position:0% +question uh that in the beginning of of +the chapter Martin uh talks a bit about + + align:start position:0% +the chapter Martin uh talks a bit about + + + align:start position:0% +the chapter Martin uh talks a bit about +this question of micro parasites versus + + align:start position:0% +this question of micro parasites versus + + + align:start position:0% +this question of micro parasites versus +macro + + align:start position:0% +macro + + + align:start position:0% +macro +parasites and can can somebody remind us + + align:start position:0% +parasites and can can somebody remind us + + + align:start position:0% +parasites and can can somebody remind us +what what's the distinction and what + + align:start position:0% +what what's the distinction and what + + + align:start position:0% +what what's the distinction and what +kind of uh what kind of parasite might + + align:start position:0% +kind of uh what kind of parasite might + + + align:start position:0% +kind of uh what kind of parasite might +this be intended to + + align:start position:0% + + + + align:start position:0% + +model + + align:start position:0% + + + + align:start position:0% + +yes what I got from it is that micro + + align:start position:0% +yes what I got from it is that micro + + + align:start position:0% +yes what I got from it is that micro +micro parasites + + align:start position:0% +micro parasites + + + align:start position:0% +micro parasites +are on the order of + + align:start position:0% + + + + align:start position:0% + +that's + + align:start position:0% + + + + align:start position:0% + +right right and you know and I'd say + + align:start position:0% +right right and you know and I'd say + + + align:start position:0% +right right and you know and I'd say +that just given this distinction between + + align:start position:0% +that just given this distinction between + + + align:start position:0% +that just given this distinction between +the micro parasites that might be + + align:start position:0% +the micro parasites that might be + + + align:start position:0% +the micro parasites that might be +viruses and bacteria as compared to the + + align:start position:0% +viruses and bacteria as compared to the + + + align:start position:0% +viruses and bacteria as compared to the +macro parasites that are things like you + + align:start position:0% +macro parasites that are things like you + + + align:start position:0% +macro parasites that are things like you +know tapeworms and so forth + + align:start position:0% +know tapeworms and so forth + + + align:start position:0% +know tapeworms and so forth +it's not obvious from that that you + + align:start position:0% +it's not obvious from that that you + + + align:start position:0% +it's not obvious from that that you +would have two different kind of + + align:start position:0% +would have two different kind of + + + align:start position:0% +would have two different kind of +modeling Frameworks but what what is the + + align:start position:0% +modeling Frameworks but what what is the + + + align:start position:0% +modeling Frameworks but what what is the +argument that um that is made in in + + align:start position:0% +argument that um that is made in in + + + align:start position:0% +argument that um that is made in in +Martin's Martin's book or can you think + + align:start position:0% +Martin's Martin's book or can you think + + + align:start position:0% +Martin's Martin's book or can you think +up an argument for why it is that it + + align:start position:0% +up an argument for why it is that it + + + align:start position:0% +up an argument for why it is that it +might be this kind of model you would + + align:start position:0% +might be this kind of model you would + + + align:start position:0% +might be this kind of model you would +want to use for micro + + align:start position:0% + + + + align:start position:0% + +parasites + + align:start position:0% + + + + align:start position:0% + +yes large individual we don't have to + + align:start position:0% +yes large individual we don't have to + + + align:start position:0% +yes large individual we don't have to +keep track of the internal + + align:start position:0% +keep track of the internal + + + align:start position:0% +keep track of the internal +that's right I'd say that and some of + + align:start position:0% +that's right I'd say that and some of + + + align:start position:0% +that's right I'd say that and some of +it's maybe even a historical thing that + + align:start position:0% +it's maybe even a historical thing that + + + align:start position:0% +it's maybe even a historical thing that +we there might be right huge numbers of + + align:start position:0% +we there might be right huge numbers of + + + align:start position:0% +we there might be right huge numbers of +viruses you know a flu virus or so in in + + align:start position:0% +viruses you know a flu virus or so in in + + + align:start position:0% +viruses you know a flu virus or so in in +an infected individual and in some ways + + align:start position:0% +an infected individual and in some ways + + + align:start position:0% +an infected individual and in some ways +maybe the number of viruses that is in + + align:start position:0% +maybe the number of viruses that is in + + + align:start position:0% +maybe the number of viruses that is in +that host is not the most relevant thing + + align:start position:0% +that host is not the most relevant thing + + + align:start position:0% +that host is not the most relevant thing +uh and it certainly would be much more + + align:start position:0% +uh and it certainly would be much more + + + align:start position:0% +uh and it certainly would be much more +complicated to try to keep track of that + + align:start position:0% +complicated to try to keep track of that + + + align:start position:0% +complicated to try to keep track of that +right so if uh if you can get um kind of + + align:start position:0% +right so if uh if you can get um kind of + + + align:start position:0% +right so if uh if you can get um kind of +meaningful predictions by instead of + + align:start position:0% +meaningful predictions by instead of + + + align:start position:0% +meaningful predictions by instead of +keeping track rather than keeping track + + align:start position:0% +keeping track rather than keeping track + + + align:start position:0% +keeping track rather than keeping track +of the number of viruses say in each + + align:start position:0% +of the number of viruses say in each + + + align:start position:0% +of the number of viruses say in each +host instead you just put the hosts into + + align:start position:0% +host instead you just put the hosts into + + + align:start position:0% +host instead you just put the hosts into +different classes you know sensitive and + + align:start position:0% +different classes you know sensitive and + + + align:start position:0% +different classes you know sensitive and +infected for example later we'll talk + + align:start position:0% +infected for example later we'll talk + + + align:start position:0% +infected for example later we'll talk +about what happens if you have a + + align:start position:0% +about what happens if you have a + + + align:start position:0% +about what happens if you have a +resistant type of class right but but + + align:start position:0% +resistant type of class right but but + + + align:start position:0% +resistant type of class right but but +the idea there is that there's maybe + + align:start position:0% +the idea there is that there's maybe + + + align:start position:0% +the idea there is that there's maybe +even also some separation of time scales + + align:start position:0% +even also some separation of time scales + + + align:start position:0% +even also some separation of time scales +right because you get infected and kind + + align:start position:0% +right because you get infected and kind + + + align:start position:0% +right because you get infected and kind +of quickly you come to you're just sick + + align:start position:0% +of quickly you come to you're just sick + + + align:start position:0% +of quickly you come to you're just sick +and maybe + + align:start position:0% +and maybe + + + align:start position:0% +and maybe +infective and but at some rate you get + + align:start position:0% +infective and but at some rate you get + + + align:start position:0% +infective and but at some rate you get +you get better and it's not that uh it + + align:start position:0% +you get better and it's not that uh it + + + align:start position:0% +you get better and it's not that uh it +you'll necessarily gain very much by + + align:start position:0% +you'll necessarily gain very much by + + + align:start position:0% +you'll necessarily gain very much by +keeping track of the precise number of + + align:start position:0% +keeping track of the precise number of + + + align:start position:0% +keeping track of the precise number of +viruses in the h post okay of course + + align:start position:0% +viruses in the h post okay of course + + + align:start position:0% +viruses in the h post okay of course +this is ultimately an experimental + + align:start position:0% +this is ultimately an experimental + + + align:start position:0% +this is ultimately an experimental +observational question of whether this + + align:start position:0% +observational question of whether this + + + align:start position:0% +observational question of whether this +sort of model provides you the Insight + + align:start position:0% +sort of model provides you the Insight + + + align:start position:0% +sort of model provides you the Insight +that that you're going to need to make + + align:start position:0% +that that you're going to need to make + + + align:start position:0% +that that you're going to need to make +sense of these diseases + + align:start position:0% + + + + align:start position:0% + +right that's right so the mechanism of + + align:start position:0% +right that's right so the mechanism of + + + align:start position:0% +right that's right so the mechanism of +transmission and this this depends very + + align:start position:0% +transmission and this this depends very + + + align:start position:0% +transmission and this this depends very +much on uh on the disease that you're + + align:start position:0% +much on uh on the disease that you're + + + align:start position:0% +much on uh on the disease that you're +studying right uh and the macro + + align:start position:0% +studying right uh and the macro + + + align:start position:0% +studying right uh and the macro +parasites in many cases they're they're + + align:start position:0% +parasites in many cases they're they're + + + align:start position:0% +parasites in many cases they're they're +transmitted not from direct interactions + + align:start position:0% +transmitted not from direct interactions + + + align:start position:0% +transmitted not from direct interactions +between the hosts but through + + align:start position:0% +between the hosts but through + + + align:start position:0% +between the hosts but through +uh you know through the environment or + + align:start position:0% +uh you know through the environment or + + + align:start position:0% +uh you know through the environment or +something else + + align:start position:0% + + + + align:start position:0% + +yeah um it's also perhaps just worth + + align:start position:0% +yeah um it's also perhaps just worth + + + align:start position:0% +yeah um it's also perhaps just worth +pointing out that uh that parasites are + + align:start position:0% +pointing out that uh that parasites are + + + align:start position:0% +pointing out that uh that parasites are +just a ubiquitous aspect of life right + + align:start position:0% +just a ubiquitous aspect of life right + + + align:start position:0% +just a ubiquitous aspect of life right +so you can kind of uh name an organism + + align:start position:0% +so you can kind of uh name an organism + + + align:start position:0% +so you can kind of uh name an organism +and you can pretty much uh be guaranteed + + align:start position:0% +and you can pretty much uh be guaranteed + + + align:start position:0% +and you can pretty much uh be guaranteed +that there's going to be some notion of + + align:start position:0% +that there's going to be some notion of + + + align:start position:0% +that there's going to be some notion of +a parasite on on that organism and there + + align:start position:0% +a parasite on on that organism and there + + + align:start position:0% +a parasite on on that organism and there +can be multiple uh multiple layers of + + align:start position:0% +can be multiple uh multiple layers of + + + align:start position:0% +can be multiple uh multiple layers of +this right so U you know we certainly + + align:start position:0% +this right so U you know we certainly + + + align:start position:0% +this right so U you know we certainly +have many parasites we we we're infected + + align:start position:0% +have many parasites we we we're infected + + + align:start position:0% +have many parasites we we we're infected +by many viruses and bacteria and and + + align:start position:0% +by many viruses and bacteria and and + + + align:start position:0% +by many viruses and bacteria and and +other things right but uh but bacteria + + align:start position:0% +other things right but uh but bacteria + + + align:start position:0% +other things right but uh but bacteria +even though you know we think of them as + + align:start position:0% +even though you know we think of them as + + + align:start position:0% +even though you know we think of them as +being very small but they're also prayed + + align:start position:0% +being very small but they're also prayed + + + align:start position:0% +being very small but they're also prayed +upon by by these Fage right which are uh + + align:start position:0% +upon by by these Fage right which are uh + + + align:start position:0% +upon by by these Fage right which are uh +which is it's a it's a parasite that + + align:start position:0% +which is it's a it's a parasite that + + + align:start position:0% +which is it's a it's a parasite that +targets specifically bacteria right so + + align:start position:0% +targets specifically bacteria right so + + + align:start position:0% +targets specifically bacteria right so +it's not just that it's an incidental + + align:start position:0% +it's not just that it's an incidental + + + align:start position:0% +it's not just that it's an incidental +thing that but these are really uh + + align:start position:0% +thing that but these are really uh + + + align:start position:0% +thing that but these are really uh +viruses that have evolved specifically + + align:start position:0% +viruses that have evolved specifically + + + align:start position:0% +viruses that have evolved specifically +to to divide in bacteria right um and in + + align:start position:0% +to to divide in bacteria right um and in + + + align:start position:0% +to to divide in bacteria right um and in +uh we didn't really talk about this very + + align:start position:0% +uh we didn't really talk about this very + + + align:start position:0% +uh we didn't really talk about this very +much but one of the classic models for + + align:start position:0% +much but one of the classic models for + + + align:start position:0% +much but one of the classic models for +uh cooperation and cheating uh is based + + align:start position:0% +uh cooperation and cheating uh is based + + + align:start position:0% +uh cooperation and cheating uh is based +on what you could think about as some + + align:start position:0% +on what you could think about as some + + + align:start position:0% +on what you could think about as some +sort of uh parasitic subpopulation + + align:start position:0% +sort of uh parasitic subpopulation + + + align:start position:0% +sort of uh parasitic subpopulation +within phage right so this is a classic + + align:start position:0% +within phage right so this is a classic + + + align:start position:0% +within phage right so this is a classic +paper by lyncha where he showed that if + + align:start position:0% +paper by lyncha where he showed that if + + + align:start position:0% +paper by lyncha where he showed that if +you evolve phage in bacteria in a + + align:start position:0% +you evolve phage in bacteria in a + + + align:start position:0% +you evolve phage in bacteria in a +condition where many Fage infect a given + + align:start position:0% +condition where many Fage infect a given + + + align:start position:0% +condition where many Fage infect a given +bacteria then uh you can evolve what you + + align:start position:0% +bacteria then uh you can evolve what you + + + align:start position:0% +bacteria then uh you can evolve what you +could think of as cheater uh cheater + + align:start position:0% +could think of as cheater uh cheater + + + align:start position:0% +could think of as cheater uh cheater +strategies or cheater Fage because these + + align:start position:0% +strategies or cheater Fage because these + + + align:start position:0% +strategies or cheater Fage because these +are Fage that don't um they maybe can't + + align:start position:0% +are Fage that don't um they maybe can't + + + align:start position:0% +are Fage that don't um they maybe can't +reproduce on their own but have shorter + + align:start position:0% +reproduce on their own but have shorter + + + align:start position:0% +reproduce on their own but have shorter +genomes and can kind of out produ you + + align:start position:0% +genomes and can kind of out produ you + + + align:start position:0% +genomes and can kind of out produ you +know can out replicate the normal phage + + align:start position:0% +know can out replicate the normal phage + + + align:start position:0% +know can out replicate the normal phage +so if these both of these end up in a + + align:start position:0% +so if these both of these end up in a + + + align:start position:0% +so if these both of these end up in a +single bacterial cell then these cheater + + align:start position:0% +single bacterial cell then these cheater + + + align:start position:0% +single bacterial cell then these cheater +Fage can spread by by taking advantage + + align:start position:0% +Fage can spread by by taking advantage + + + align:start position:0% +Fage can spread by by taking advantage +of the say the replication Machinery + + align:start position:0% +of the say the replication Machinery + + + align:start position:0% +of the say the replication Machinery +from the rest of the Fage so this is in + + align:start position:0% +from the rest of the Fage so this is in + + + align:start position:0% +from the rest of the Fage so this is in +some ways you might call that a some + + align:start position:0% +some ways you might call that a some + + + align:start position:0% +some ways you might call that a some +sort of DNA parasite or or so right so + + align:start position:0% +sort of DNA parasite or or so right so + + + align:start position:0% +sort of DNA parasite or or so right so +there's really parasites at many many + + align:start position:0% +there's really parasites at many many + + + align:start position:0% +there's really parasites at many many +different levels + + align:start position:0% + + + + align:start position:0% + +okay yes + + align:start position:0% + + + + align:start position:0% + +yeah you know uh I I would say that yeah + + align:start position:0% +yeah you know uh I I would say that yeah + + + align:start position:0% +yeah you know uh I I would say that yeah +the K is in some ways not a very + + align:start position:0% +the K is in some ways not a very + + + align:start position:0% +the K is in some ways not a very +satisfying feature of this model because + + align:start position:0% +satisfying feature of this model because + + + align:start position:0% +satisfying feature of this model because +it makes it feel that the model is very + + align:start position:0% +it makes it feel that the model is very + + + align:start position:0% +it makes it feel that the model is very +special right but I mean in an actual + + align:start position:0% +special right but I mean in an actual + + + align:start position:0% +special right but I mean in an actual +population + + align:start position:0% + + + + align:start position:0% + +people uh yeah yes so I guess that that + + align:start position:0% +people uh yeah yes so I guess that that + + + align:start position:0% +people uh yeah yes so I guess that that +was the example I was going to give it's + + align:start position:0% +was the example I was going to give it's + + + align:start position:0% +was the example I was going to give it's +not clear that um that this is of course + + align:start position:0% +not clear that um that this is of course + + + align:start position:0% +not clear that um that this is of course +it requires Ires somebody to give birth + + align:start position:0% +it requires Ires somebody to give birth + + + align:start position:0% +it requires Ires somebody to give birth +to kids right so you know so in that + + align:start position:0% +to kids right so you know so in that + + + align:start position:0% +to kids right so you know so in that +sense modeling this is a constant number + + align:start position:0% +sense modeling this is a constant number + + + align:start position:0% +sense modeling this is a constant number +per unit time which is what we're doing + + align:start position:0% +per unit time which is what we're doing + + + align:start position:0% +per unit time which is what we're doing +this rate K right is is a little bit + + align:start position:0% +this rate K right is is a little bit + + + align:start position:0% +this rate K right is is a little bit +funny because then what you'd really + + align:start position:0% +funny because then what you'd really + + + align:start position:0% +funny because then what you'd really +want to do is say oh maybe that it's + + align:start position:0% +want to do is say oh maybe that it's + + + align:start position:0% +want to do is say oh maybe that it's +it's these guys that give birth at some + + align:start position:0% +it's these guys that give birth at some + + + align:start position:0% +it's these guys that give birth at some +rate or so if you really wanted it to be + + align:start position:0% +rate or so if you really wanted it to be + + + align:start position:0% +rate or so if you really wanted it to be +accurate so I'd say that this is u in + + align:start position:0% +accurate so I'd say that this is u in + + + align:start position:0% +accurate so I'd say that this is u in +some ways just a mathematical + + align:start position:0% +some ways just a mathematical + + + align:start position:0% +some ways just a mathematical +simplification so that we can uh get at + + align:start position:0% +simplification so that we can uh get at + + + align:start position:0% +simplification so that we can uh get at +the heart of the Dynamics and what we'll + + align:start position:0% +the heart of the Dynamics and what we'll + + + align:start position:0% +the heart of the Dynamics and what we'll +see is that in these sir models uh you + + align:start position:0% +see is that in these sir models uh you + + + align:start position:0% +see is that in these sir models uh you +don't invoke anything like uh like this + + align:start position:0% +don't invoke anything like uh like this + + + align:start position:0% +don't invoke anything like uh like this +but rather what you do is you assume + + align:start position:0% +but rather what you do is you assume + + + align:start position:0% +but rather what you do is you assume +that at some rate in infected + + align:start position:0% +that at some rate in infected + + + align:start position:0% +that at some rate in infected +individuals uh can um well they don't + + align:start position:0% +individuals uh can um well they don't + + + align:start position:0% +individuals uh can um well they don't +just die but they they become resistant + + align:start position:0% +just die but they they become resistant + + + align:start position:0% +just die but they they become resistant +and then maybe later they become + + align:start position:0% +and then maybe later they become + + + align:start position:0% +and then maybe later they become +sensitive again right so so you just + + align:start position:0% +sensitive again right so so you just + + + align:start position:0% +sensitive again right so so you just +need you need some way of making sure + + align:start position:0% +need you need some way of making sure + + + align:start position:0% +need you need some way of making sure +that it's not the case that everybody + + align:start position:0% +that it's not the case that everybody + + + align:start position:0% +that it's not the case that everybody +just always dies + + align:start position:0% +just always dies + + + align:start position:0% +just always dies +right so in some ways this is more + + align:start position:0% +right so in some ways this is more + + + align:start position:0% +right so in some ways this is more +mathematical convenience and uh the + + align:start position:0% +mathematical convenience and uh the + + + align:start position:0% +mathematical convenience and uh the +basic conclusions end up being very + + align:start position:0% +basic conclusions end up being very + + + align:start position:0% +basic conclusions end up being very +robust to these sorts of things + + align:start position:0% +robust to these sorts of things + + + align:start position:0% +robust to these sorts of things +okay all right + + align:start position:0% + + + + align:start position:0% + +right so it's uh you know in in these + + align:start position:0% +right so it's uh you know in in these + + + align:start position:0% +right so it's uh you know in in these +models it's always good to be clear + + align:start position:0% +models it's always good to be clear + + + align:start position:0% +models it's always good to be clear +about uh how we kind of go from this + + align:start position:0% +about uh how we kind of go from this + + + align:start position:0% +about uh how we kind of go from this +framework to something that is is more + + align:start position:0% +framework to something that is is more + + + align:start position:0% +framework to something that is is more +of a differential equation uh and what + + align:start position:0% +of a differential equation uh and what + + + align:start position:0% +of a differential equation uh and what +we're what we can do is we can think + + align:start position:0% +we're what we can do is we can think + + + align:start position:0% +we're what we can do is we can think +about the uh these uninfected + + align:start position:0% +about the uh these uninfected + + + align:start position:0% +about the uh these uninfected +individuals + + align:start position:0% +individuals + + + align:start position:0% +individuals +uninfected I.E the S's and as compared + + align:start position:0% +uninfected I.E the S's and as compared + + + align:start position:0% +uninfected I.E the S's and as compared +to the + + align:start position:0% + + + + align:start position:0% + +infected and we're going to have these + + align:start position:0% +infected and we're going to have these + + + align:start position:0% +infected and we're going to have these +guys be + + align:start position:0% +guys be + + + align:start position:0% +guys be +X right so first of all all the way that + + align:start position:0% +X right so first of all all the way that + + + align:start position:0% +X right so first of all all the way that +the and this is okay this is s and I + + align:start position:0% +the and this is okay this is s and I + + + align:start position:0% +the and this is okay this is s and I +right so the way that that the that X + + align:start position:0% +right so the way that that the that X + + + align:start position:0% +right so the way that that the that X +will be changing is that you we're + + align:start position:0% +will be changing is that you we're + + + align:start position:0% +will be changing is that you we're +assuming that that there's always some + + align:start position:0% +assuming that that there's always some + + + align:start position:0% +assuming that that there's always some +influx of individuals which could be + + align:start position:0% +influx of individuals which could be + + + align:start position:0% +influx of individuals which could be +birth or migration or something else + + align:start position:0% +birth or migration or something else + + + align:start position:0% +birth or migration or something else +right that are just always entering okay + + align:start position:0% +right that are just always entering okay + + + align:start position:0% +right that are just always entering okay +but then there's going to be two ways + + align:start position:0% +but then there's going to be two ways + + + align:start position:0% +but then there's going to be two ways +that uh that X is going to decrease + + align:start position:0% +that uh that X is going to decrease + + + align:start position:0% +that uh that X is going to decrease +right one is that there's just a death + + align:start position:0% +right one is that there's just a death + + + align:start position:0% +right one is that there's just a death +rate that is resulting uh in the absence + + align:start position:0% +rate that is resulting uh in the absence + + + align:start position:0% +rate that is resulting uh in the absence +of infection okay but then also there's + + align:start position:0% +of infection okay but then also there's + + + align:start position:0% +of infection okay but then also there's +going to be some of infection which is + + align:start position:0% +going to be some of infection which is + + + align:start position:0% +going to be some of infection which is +going to be proportional to Beta right + + align:start position:0% +going to be proportional to Beta right + + + align:start position:0% +going to be proportional to Beta right +so this is the simplest way that you can + + align:start position:0% +so this is the simplest way that you can + + + align:start position:0% +so this is the simplest way that you can +imagine uh uh capturing this this + + align:start position:0% +imagine uh uh capturing this this + + + align:start position:0% +imagine uh uh capturing this this +element that that the infected + + align:start position:0% +element that that the infected + + + align:start position:0% +element that that the infected +individuals uh can uh can transmit the + + align:start position:0% +individuals uh can uh can transmit the + + + align:start position:0% +individuals uh can uh can transmit the +infection to the sensitive individuals + + align:start position:0% +infection to the sensitive individuals + + + align:start position:0% +infection to the sensitive individuals +okay so it's proportional to someh we're + + align:start position:0% +okay so it's proportional to someh we're + + + align:start position:0% +okay so it's proportional to someh we're +we're modeling them as it's just a well- + + align:start position:0% +we're modeling them as it's just a well- + + + align:start position:0% +we're modeling them as it's just a well- +mixed population just like in chemical + + align:start position:0% +mixed population just like in chemical + + + align:start position:0% +mixed population just like in chemical +reactions and uh somehow the the rate of + + align:start position:0% +reactions and uh somehow the the rate of + + + align:start position:0% +reactions and uh somehow the the rate of +infection is proportional to the kind of + + align:start position:0% +infection is proportional to the kind of + + + align:start position:0% +infection is proportional to the kind of +frequency that they they hit each other + + align:start position:0% +frequency that they they hit each other + + + align:start position:0% +frequency that they they hit each other +right certainly the simplest simplest + + align:start position:0% +right certainly the simplest simplest + + + align:start position:0% +right certainly the simplest simplest +kind of model you can imagine okay all + + align:start position:0% +kind of model you can imagine okay all + + + align:start position:0% +kind of model you can imagine okay all +right whereas the infected individuals + + align:start position:0% +right whereas the infected individuals + + + align:start position:0% +right whereas the infected individuals +well what we're going to have is we're + + align:start position:0% +well what we're going to have is we're + + + align:start position:0% +well what we're going to have is we're +going to have an increased rate of death + + align:start position:0% +going to have an increased rate of death + + + align:start position:0% +going to have an increased rate of death +right uh so the simp all right this is a + + align:start position:0% +right uh so the simp all right this is a + + + align:start position:0% +right uh so the simp all right this is a +simplified way to write + + align:start position:0% + + + + align:start position:0% + +it okay right so this is really that + + align:start position:0% +it okay right so this is really that + + + align:start position:0% +it okay right so this is really that +there's a minus kind of a u plus v * y + + align:start position:0% +there's a minus kind of a u plus v * y + + + align:start position:0% +there's a minus kind of a u plus v * y +so this is just the death rate okay but + + align:start position:0% +so this is just the death rate okay but + + + align:start position:0% +so this is just the death rate okay but +then uh any individual that leaves the + + align:start position:0% +then uh any individual that leaves the + + + align:start position:0% +then uh any individual that leaves the +sensitive class this Min minus beta XY + + align:start position:0% +sensitive class this Min minus beta XY + + + align:start position:0% +sensitive class this Min minus beta XY +enters the uh infected + + align:start position:0% + + + + align:start position:0% + +class right right so this this makes a + + align:start position:0% +class right right so this this makes a + + + align:start position:0% +class right right so this this makes a +lot of sense I think and now the + + align:start position:0% +lot of sense I think and now the + + + align:start position:0% +lot of sense I think and now the +question is um can we can we kind of + + align:start position:0% +question is um can we can we kind of + + + align:start position:0% +question is um can we can we kind of +make make sense of what's going on now + + align:start position:0% +make make sense of what's going on now + + + align:start position:0% +make make sense of what's going on now +uh + + align:start position:0% +uh + + + align:start position:0% +uh +the right so you you saw in your reading + + align:start position:0% +the right so you you saw in your reading + + + align:start position:0% +the right so you you saw in your reading +what this R not parameter was right you + + align:start position:0% +what this R not parameter was right you + + + align:start position:0% +what this R not parameter was right you +should always remember that it's defined + + align:start position:0% +should always remember that it's defined + + + align:start position:0% +should always remember that it's defined +as this thing of if you kind of have one + + align:start position:0% +as this thing of if you kind of have one + + + align:start position:0% +as this thing of if you kind of have one +if you introduce one infected individual + + align:start position:0% +if you introduce one infected individual + + + align:start position:0% +if you introduce one infected individual +into a population of sensitive + + align:start position:0% +into a population of sensitive + + + align:start position:0% +into a population of sensitive +individuals what is the mean number of + + align:start position:0% +individuals what is the mean number of + + + align:start position:0% +individuals what is the mean number of +new infections that you get right and it + + align:start position:0% +new infections that you get right and it + + + align:start position:0% +new infections that you get right and it +makes sense that that the key thing is + + align:start position:0% +makes sense that that the key thing is + + + align:start position:0% +makes sense that that the key thing is +whether that that are not is kind of + + align:start position:0% +whether that that are not is kind of + + + align:start position:0% +whether that that are not is kind of +greater or less than one because if it's + + align:start position:0% +greater or less than one because if it's + + + align:start position:0% +greater or less than one because if it's +greater than one that leads to this + + align:start position:0% +greater than one that leads to this + + + align:start position:0% +greater than one that leads to this +exponential kind of explosion of the + + align:start position:0% +exponential kind of explosion of the + + + align:start position:0% +exponential kind of explosion of the +infected individuals doesn't mean that + + align:start position:0% +infected individuals doesn't mean that + + + align:start position:0% +infected individuals doesn't mean that +everyone's going to die necessarily + + align:start position:0% +everyone's going to die necessarily + + + align:start position:0% +everyone's going to die necessarily +because uh well we'll get into that but + + align:start position:0% +because uh well we'll get into that but + + + align:start position:0% +because uh well we'll get into that but +okay but if R not is less than one then + + align:start position:0% +okay but if R not is less than one then + + + align:start position:0% +okay but if R not is less than one then +then you expect that uh that infection + + align:start position:0% +then you expect that uh that infection + + + align:start position:0% +then you expect that uh that infection +to kind of die out right so why is it + + align:start position:0% +to kind of die out right so why is it + + + align:start position:0% +to kind of die out right so why is it +that that when you int if if R not is + + align:start position:0% +that that when you int if if R not is + + + align:start position:0% +that that when you int if if R not is +greater than one and you introduce one + + align:start position:0% +greater than one and you introduce one + + + align:start position:0% +greater than one and you introduce one +infected individual doesn't necessarily + + align:start position:0% +infected individual doesn't necessarily + + + align:start position:0% +infected individual doesn't necessarily +lead to you know kind of you know wipe + + align:start position:0% +lead to you know kind of you know wipe + + + align:start position:0% +lead to you know kind of you know wipe +out of the entire + + align:start position:0% + + + + align:start position:0% + +population or maybe it does + + align:start position:0% +population or maybe it does + + + align:start position:0% +population or maybe it does +I this model is a little funny because + + align:start position:0% +I this model is a little funny because + + + align:start position:0% +I this model is a little funny because +you always have individuals entering + + align:start position:0% +you always have individuals entering + + + align:start position:0% +you always have individuals entering +right + + align:start position:0% + + + + align:start position:0% + +but right okay so if it's very virent + + align:start position:0% +but right okay so if it's very virent + + + align:start position:0% +but right okay so if it's very virent +then the infected individuals may die + + align:start position:0% +then the infected individuals may die + + + align:start position:0% +then the infected individuals may die +quickly and this gets into this question + + align:start position:0% +quickly and this gets into this question + + + align:start position:0% +quickly and this gets into this question +of there may be some trade-offs in terms + + align:start position:0% +of there may be some trade-offs in terms + + + align:start position:0% +of there may be some trade-offs in terms +of veilance and we'll talk more about + + align:start position:0% +of veilance and we'll talk more about + + + align:start position:0% +of veilance and we'll talk more about +then the EV evolution of veilance but I + + align:start position:0% +then the EV evolution of veilance but I + + + align:start position:0% +then the EV evolution of veilance but I +guess the question is uh in in in + + align:start position:0% +guess the question is uh in in in + + + align:start position:0% +guess the question is uh in in in +there's a wide variety of classes of + + align:start position:0% +there's a wide variety of classes of + + + align:start position:0% +there's a wide variety of classes of +models not just where the ones where you + + align:start position:0% +models not just where the ones where you + + + align:start position:0% +models not just where the ones where you +have K entering but the the question + + align:start position:0% +have K entering but the the question + + + align:start position:0% +have K entering but the the question +somehow is um just because R not as + + align:start position:0% +somehow is um just because R not as + + + align:start position:0% +somehow is um just because R not as +greater than one that doesn't mean that + + align:start position:0% +greater than one that doesn't mean that + + + align:start position:0% +greater than one that doesn't mean that +the entire population will necessarily + + align:start position:0% +the entire population will necessarily + + + align:start position:0% +the entire population will necessarily +become infected right so because we have + + align:start position:0% +become infected right so because we have + + + align:start position:0% +become infected right so because we have +this idea of an exponential growth of + + align:start position:0% +this idea of an exponential growth of + + + align:start position:0% +this idea of an exponential growth of +the infected population if R kns greater + + align:start position:0% +the infected population if R kns greater + + + align:start position:0% +the infected population if R kns greater +than one + + align:start position:0% +than one + + + align:start position:0% +than one +right so why is it that it's not + + align:start position:0% +right so why is it that it's not + + + align:start position:0% +right so why is it that it's not +necessarily going to happen that the + + align:start position:0% +necessarily going to happen that the + + + align:start position:0% +necessarily going to happen that the +entire population + + align:start position:0% + + + + align:start position:0% + +is this question is a little bit ill + + align:start position:0% +is this question is a little bit ill + + + align:start position:0% +is this question is a little bit ill +posed in this + + align:start position:0% +posed in this + + + align:start position:0% +posed in this +model it + + align:start position:0% + + + + align:start position:0% + +because some that's right okay I think + + align:start position:0% +because some that's right okay I think + + + align:start position:0% +because some that's right okay I think +this is the basic intuition that as the + + align:start position:0% +this is the basic intuition that as the + + + align:start position:0% +this is the basic intuition that as the +infected as more and more uh members of + + align:start position:0% +infected as more and more uh members of + + + align:start position:0% +infected as more and more uh members of +the population become infected then that + + align:start position:0% +the population become infected then that + + + align:start position:0% +the population become infected then that +could in principle reduce the um the + + align:start position:0% +could in principle reduce the um the + + + align:start position:0% +could in principle reduce the um the +possibilities for uh for new individuals + + align:start position:0% +possibilities for uh for new individuals + + + align:start position:0% +possibilities for uh for new individuals +to be Su you know kind of + + align:start position:0% +to be Su you know kind of + + + align:start position:0% +to be Su you know kind of +susceptible + + align:start position:0% +susceptible + + + align:start position:0% +susceptible +okay right and I'm using susceptible and + + align:start position:0% +okay right and I'm using susceptible and + + + align:start position:0% +okay right and I'm using susceptible and +sensitive at the same you know + + align:start position:0% +sensitive at the same you know + + + align:start position:0% +sensitive at the same you know +interchangeably um right and and So So + + align:start position:0% +interchangeably um right and and So So + + + align:start position:0% +interchangeably um right and and So So +eventually this exponential rate of uh + + align:start position:0% +eventually this exponential rate of uh + + + align:start position:0% +eventually this exponential rate of uh +kind of growth of the population can be + + align:start position:0% +kind of growth of the population can be + + + align:start position:0% +kind of growth of the population can be +kind of limited in some way right we + + align:start position:0% +kind of limited in some way right we + + + align:start position:0% +kind of limited in some way right we +we'll maybe look at this a little bit + + align:start position:0% +we'll maybe look at this a little bit + + + align:start position:0% +we'll maybe look at this a little bit +more in this s model because it's more + + align:start position:0% +more in this s model because it's more + + + align:start position:0% +more in this s model because it's more +clear um the B the basic reproductive + + align:start position:0% +clear um the B the basic reproductive + + + align:start position:0% +clear um the B the basic reproductive +or not is a + + align:start position:0% +or not is a + + + align:start position:0% +or not is a +rate + + align:start position:0% +rate + + + align:start position:0% +rate +uh no it's it's it's it's it's a number + + align:start position:0% +uh no it's it's it's it's it's a number + + + align:start position:0% +uh no it's it's it's it's it's a number +right it's this expected number of new + + align:start position:0% +right it's this expected number of new + + + align:start position:0% +right it's this expected number of new +infections you get when you introduce + + align:start position:0% +infections you get when you introduce + + + align:start position:0% +infections you get when you introduce +one infected individual into the + + align:start position:0% +one infected individual into the + + + align:start position:0% +one infected individual into the +population all right and we like period + + align:start position:0% +population all right and we like period + + + align:start position:0% +population all right and we like period +so there's no not like per unit time or + + align:start position:0% +so there's no not like per unit time or + + + align:start position:0% +so there's no not like per unit time or +it's a number okay period so you expect + + align:start position:0% +it's a number okay period so you expect + + + align:start position:0% +it's a number okay period so you expect +that if you if you have r equal to one + + align:start position:0% +that if you if you have r equal to one + + + align:start position:0% +that if you if you have r equal to one +you expect that you introduce an + + align:start position:0% +you expect that you introduce an + + + align:start position:0% +you expect that you introduce an +infected individual into a population of + + align:start position:0% +infected individual into a population of + + + align:start position:0% +infected individual into a population of +sensive individuals you will get one + + align:start position:0% +sensive individuals you will get one + + + align:start position:0% +sensive individuals you will get one +other infected that's right so that's + + align:start position:0% +other infected that's right so that's + + + align:start position:0% +other infected that's right so that's +kind of the neutrally stable situation + + align:start position:0% +kind of the neutrally stable situation + + + align:start position:0% +kind of the neutrally stable situation +if R's one then you you add one + + align:start position:0% +if R's one then you you add one + + + align:start position:0% +if R's one then you you add one +infectant individual and you expect to + + align:start position:0% +infectant individual and you expect to + + + align:start position:0% +infectant individual and you expect to +get one other one so you have a random + + align:start position:0% +get one other one so you have a random + + + align:start position:0% +get one other one so you have a random +walk and it'll either it'll well in + + align:start position:0% +walk and it'll either it'll well in + + + align:start position:0% +walk and it'll either it'll well in +general it'll it'll randomly go extinct + + align:start position:0% +general it'll it'll randomly go extinct + + + align:start position:0% +general it'll it'll randomly go extinct +eventually yeah + + align:start position:0% + + + + align:start position:0% + +yes right so it depends upon a number + + align:start position:0% +yes right so it depends upon a number + + + align:start position:0% +yes right so it depends upon a number +yeah so let that's what we're going to + + align:start position:0% +yeah so let that's what we're going to + + + align:start position:0% +yeah so let that's what we're going to +do right now is is uh see if we can + + align:start position:0% +do right now is is uh see if we can + + + align:start position:0% +do right now is is uh see if we can +reconstruct what this R is equal to in + + align:start position:0% +reconstruct what this R is equal to in + + + align:start position:0% +reconstruct what this R is equal to in +in this model another question what's + + align:start position:0% +in this model another question what's + + + align:start position:0% +in this model another question what's +the + + align:start position:0% + + + + align:start position:0% + +distrib deterministic yes exactly right + + align:start position:0% +distrib deterministic yes exactly right + + + align:start position:0% +distrib deterministic yes exactly right +so this is this is very interesting uh + + align:start position:0% +so this is this is very interesting uh + + + align:start position:0% +so this is this is very interesting uh +right so the question is what is going + + align:start position:0% +right so the question is what is going + + + align:start position:0% +right so the question is what is going +to be the distribution of the number of + + align:start position:0% +to be the distribution of the number of + + + align:start position:0% +to be the distribution of the number of +infected individuals right and in this + + align:start position:0% +infected individuals right and in this + + + align:start position:0% +infected individuals right and in this +model we're assuming that every infected + + align:start position:0% +model we're assuming that every infected + + + align:start position:0% +model we're assuming that every infected +individual is the same right so we + + align:start position:0% +individual is the same right so we + + + align:start position:0% +individual is the same right so we +should be able to all right I wish that + + align:start position:0% +should be able to all right I wish that + + + align:start position:0% +should be able to all right I wish that +we just on the wall somewhere had our + + align:start position:0% +we just on the wall somewhere had our + + + align:start position:0% +we just on the wall somewhere had our +five different standard probability + + align:start position:0% +five different standard probability + + + align:start position:0% +five different standard probability +distributions right so that we could + + align:start position:0% +distributions right so that we could + + + align:start position:0% +distributions right so that we could +always go back to them right but what uh + + align:start position:0% +always go back to them right but what uh + + + align:start position:0% +always go back to them right but what uh +right so the question is in this model + + align:start position:0% +right so the question is in this model + + + align:start position:0% +right so the question is in this model +if you have if you introduce one + + align:start position:0% +if you have if you introduce one + + + align:start position:0% +if you have if you introduce one +infected individual in the population + + align:start position:0% +infected individual in the population + + + align:start position:0% +infected individual in the population +how many new infected individuals you + + align:start position:0% +how many new infected individuals you + + + align:start position:0% +how many new infected individuals you +get are not tells you about the mean + + align:start position:0% +get are not tells you about the mean + + + align:start position:0% +get are not tells you about the mean +right but will you always get the mean + + align:start position:0% +right but will you always get the mean + + + align:start position:0% +right but will you always get the mean +no right uh all right so let's let's all + + align:start position:0% +no right uh all right so let's let's all + + + align:start position:0% +no right uh all right so let's let's all +think about this for 10 seconds and we + + align:start position:0% +think about this for 10 seconds and we + + + align:start position:0% +think about this for 10 seconds and we +will verbally kind of yell out what we + + align:start position:0% +will verbally kind of yell out what we + + + align:start position:0% +will verbally kind of yell out what we +think the distribution will be of the + + align:start position:0% +think the distribution will be of the + + + align:start position:0% +think the distribution will be of the +number of new infections from a single + + align:start position:0% +number of new infections from a single + + + align:start position:0% +number of new infections from a single +infected + + align:start position:0% + + + + align:start position:0% + +individual okay + + align:start position:0% + + + + align:start position:0% + +all right we're verbally ready + + align:start position:0% + + + + align:start position:0% + +five all right everybody thinks it's Pon + + align:start position:0% +five all right everybody thinks it's Pon + + + align:start position:0% +five all right everybody thinks it's Pon +why why would it be + + align:start position:0% + + + + align:start position:0% + +Pon + + align:start position:0% +Pon + + + align:start position:0% +Pon +okay + + align:start position:0% +okay + + + align:start position:0% +okay +ini right okay okay so the idea is we + + align:start position:0% +ini right okay okay so the idea is we + + + align:start position:0% +ini right okay okay so the idea is we +have okay now we imagine we're infected + + align:start position:0% +have okay now we imagine we're infected + + + align:start position:0% +have okay now we imagine we're infected +individual and there's some rate that we + + align:start position:0% +individual and there's some rate that we + + + align:start position:0% +individual and there's some rate that we +are infecting others right okay now if I + + align:start position:0% +are infecting others right okay now if I + + + align:start position:0% +are infecting others right okay now if I +ask you the question oh H how many + + align:start position:0% +ask you the question oh H how many + + + align:start position:0% +ask you the question oh H how many +individuals will I infect in the + + align:start position:0% +individuals will I infect in the + + + align:start position:0% +individuals will I infect in the +next 10 days or we could do 21 days if + + align:start position:0% +next 10 days or we could do 21 days if + + + align:start position:0% +next 10 days or we could do 21 days if +you guys like that okay so uh right so + + align:start position:0% +you guys like that okay so uh right so + + + align:start position:0% +you guys like that okay so uh right so +if I ask okay how many do I infect in + + align:start position:0% +if I ask okay how many do I infect in + + + align:start position:0% +if I ask okay how many do I infect in +the next 10 days right now I'm assuming + + align:start position:0% +the next 10 days right now I'm assuming + + + align:start position:0% +the next 10 days right now I'm assuming +that I Stay Alive okay but let's say + + align:start position:0% +that I Stay Alive okay but let's say + + + align:start position:0% +that I Stay Alive okay but let's say +assuming I Stay Alive how many do I + + align:start position:0% +assuming I Stay Alive how many do I + + + align:start position:0% +assuming I Stay Alive how many do I +infect over the next 10 days that's + + align:start position:0% +infect over the next 10 days that's + + + align:start position:0% +infect over the next 10 days that's +going to be distributed + + align:start position:0% +going to be distributed + + + align:start position:0% +going to be distributed +as that is Plus on right but the + + align:start position:0% +as that is Plus on right but the + + + align:start position:0% +as that is Plus on right but the +question that you're asking is a + + align:start position:0% +question that you're asking is a + + + align:start position:0% +question that you're asking is a +different one you're asking what is + + align:start position:0% +different one you're asking what is + + + align:start position:0% +different one you're asking what is +going to be the total what is going to + + align:start position:0% +going to be the total what is going to + + + align:start position:0% +going to be the total what is going to +be the distribution of the total number + + align:start position:0% +be the distribution of the total number + + + align:start position:0% +be the distribution of the total number +of new infections that I cause right and + + align:start position:0% +of new infections that I cause right and + + + align:start position:0% +of new infections that I cause right and +this is precisely the + + align:start position:0% +this is precisely the + + + align:start position:0% +this is precisely the +same situation that we've analyzed lots + + align:start position:0% +same situation that we've analyzed lots + + + align:start position:0% +same situation that we've analyzed lots +and lots of times right what does it + + align:start position:0% +and lots of times right what does it + + + align:start position:0% +and lots of times right what does it +look + + align:start position:0% +look + + + align:start position:0% +look +like H geomet okay okay yes it's going + + align:start position:0% +like H geomet okay okay yes it's going + + + align:start position:0% +like H geomet okay okay yes it's going +to be a geometric distribution but why + + align:start position:0% +to be a geometric distribution but why + + + align:start position:0% +to be a geometric distribution but why +it well because like you can have an + + align:start position:0% +it well because like you can have an + + + align:start position:0% +it well because like you can have an +infection another infection like + + align:start position:0% +infection another infection like + + + align:start position:0% +infection another infection like +multiple that's right so what what we + + align:start position:0% +multiple that's right so what what we + + + align:start position:0% +multiple that's right so what what we +have is because we have we have an + + align:start position:0% +have is because we have we have an + + + align:start position:0% +have is because we have we have an +infected individual there's two things + + align:start position:0% +infected individual there's two things + + + align:start position:0% +infected individual there's two things +that can happen right where we have they + + align:start position:0% +that can happen right where we have they + + + align:start position:0% +that can happen right where we have they +he's going to die at some rate and he + + align:start position:0% +he's going to die at some rate and he + + + align:start position:0% +he's going to die at some rate and he +will also + + align:start position:0% + + + + align:start position:0% + +um have another there's this other rate + + align:start position:0% +um have another there's this other rate + + + align:start position:0% +um have another there's this other rate +which is going to go as beta time X or + + align:start position:0% +which is going to go as beta time X or + + + align:start position:0% +which is going to go as beta time X or +so right telling us about the rate of + + align:start position:0% +so right telling us about the rate of + + + align:start position:0% +so right telling us about the rate of +new infections and we want to know how + + align:start position:0% +new infections and we want to know how + + + align:start position:0% +new infections and we want to know how +many times we go around this Loop before + + align:start position:0% +many times we go around this Loop before + + + align:start position:0% +many times we go around this Loop before +we + + align:start position:0% +we + + + align:start position:0% +we +degrade or die or something you know + + align:start position:0% +degrade or die or something you know + + + align:start position:0% +degrade or die or something you know +disappear from the population does this + + align:start position:0% +disappear from the population does this + + + align:start position:0% +disappear from the population does this +look at all familiar all right were you + + align:start position:0% +look at all familiar all right were you + + + align:start position:0% +look at all familiar all right were you +guys the same same students that were + + align:start position:0% +guys the same same students that were + + + align:start position:0% +guys the same same students that were +here for the first half of the class + + align:start position:0% +here for the first half of the class + + + align:start position:0% +here for the first half of the class +yeah and so like + + align:start position:0% + + + + align:start position:0% + +the it's like + + align:start position:0% +the it's like + + + align:start position:0% +the it's like +number + + align:start position:0% + + + + align:start position:0% + +it's yeah evaluated when the all right + + align:start position:0% +it's yeah evaluated when the all right + + + align:start position:0% +it's yeah evaluated when the all right +so R KN is the mean size of protein + + align:start position:0% +so R KN is the mean size of protein + + + align:start position:0% +so R KN is the mean size of protein +bursts in the context of this other + + align:start position:0% +bursts in the context of this other + + + align:start position:0% +bursts in the context of this other +model which was what was the + + align:start position:0% +model which was what was the + + + align:start position:0% +model which was what was the +situation and this one's really good one + + align:start position:0% +situation and this one's really good one + + + align:start position:0% +situation and this one's really good one +for you guys to know it's going to be + + align:start position:0% + + + + align:start position:0% + +useful yeah so yeah what we saw this + + align:start position:0% +useful yeah so yeah what we saw this + + + align:start position:0% +useful yeah so yeah what we saw this +exact model in the context of gene + + align:start position:0% +exact model in the context of gene + + + align:start position:0% +exact model in the context of gene +expression and what was the what was the + + align:start position:0% +expression and what was the what was the + + + align:start position:0% +expression and what was the what was the +situation that + + align:start position:0% +situation that + + + align:start position:0% +situation that +we production of from yeah production of + + align:start position:0% +we production of from yeah production of + + + align:start position:0% +we production of from yeah production of +proteins from a single mRNA right + + align:start position:0% +proteins from a single mRNA right + + + align:start position:0% +proteins from a single mRNA right +because remember we had this thing where + + align:start position:0% +because remember we had this thing where + + + align:start position:0% +because remember we had this thing where +we had the M we and we said oh well the + + align:start position:0% +we had the M we and we said oh well the + + + align:start position:0% +we had the M we and we said oh well the +Mna is going to be degraded at some rate + + align:start position:0% +Mna is going to be degraded at some rate + + + align:start position:0% +Mna is going to be degraded at some rate +but there's also it's going to be trans + + align:start position:0% +but there's also it's going to be trans + + + align:start position:0% +but there's also it's going to be trans +it's going to be translated at some rate + + align:start position:0% +it's going to be translated at some rate + + + align:start position:0% +it's going to be translated at some rate +so the distribution number of times that + + align:start position:0% +so the distribution number of times that + + + align:start position:0% +so the distribution number of times that +it's translated before it degrades is + + align:start position:0% +it's translated before it degrades is + + + align:start position:0% +it's translated before it degrades is +going to be geometric because we go + + align:start position:0% +going to be geometric because we go + + + align:start position:0% +going to be geometric because we go +around this Loop some number of times + + align:start position:0% +around this Loop some number of times + + + align:start position:0% +around this Loop some number of times +right so this is the same same + + align:start position:0% +right so this is the same same + + + align:start position:0% +right so this is the same same +thing okay and the uh + + align:start position:0% +thing okay and the uh + + + align:start position:0% +thing okay and the uh +the right the paper that I um that I put + + align:start position:0% +the right the paper that I um that I put + + + align:start position:0% +the right the paper that I um that I put +a supplementary reading by Jam Lloyd + + align:start position:0% +a supplementary reading by Jam Lloyd + + + align:start position:0% +a supplementary reading by Jam Lloyd +Smith I always get his name and Jamie + + align:start position:0% +Smith I always get his name and Jamie + + + align:start position:0% +Smith I always get his name and Jamie +Lloyd right right something mixed up but + + align:start position:0% +Lloyd right right something mixed up but + + + align:start position:0% +Lloyd right right something mixed up but +yeah Jamie Smith um so he he was uh + + align:start position:0% +yeah Jamie Smith um so he he was uh + + + align:start position:0% +yeah Jamie Smith um so he he was uh +studying the the Dynamics of um of + + align:start position:0% +studying the the Dynamics of um of + + + align:start position:0% +studying the the Dynamics of um of +infections when you have this thing + + align:start position:0% +infections when you have this thing + + + align:start position:0% +infections when you have this thing +where there's there's intrinsic + + align:start position:0% +where there's there's intrinsic + + + align:start position:0% +where there's there's intrinsic +variation in say the infectivity of an + + align:start position:0% +variation in say the infectivity of an + + + align:start position:0% +variation in say the infectivity of an +individual right because here you get + + align:start position:0% +individual right because here you get + + + align:start position:0% +individual right because here you get +this geometric distribution even though + + align:start position:0% +this geometric distribution even though + + + align:start position:0% +this geometric distribution even though +all the individuals are principal + + align:start position:0% +all the individuals are principal + + + align:start position:0% +all the individuals are principal +identical right now the question is if + + align:start position:0% +identical right now the question is if + + + align:start position:0% +identical right now the question is if +you there's some distributions of say + + align:start position:0% +you there's some distributions of say + + + align:start position:0% +you there's some distributions of say +infectivities then you'll get an even uh + + align:start position:0% +infectivities then you'll get an even uh + + + align:start position:0% +infectivities then you'll get an even uh +kind of broader distribution of + + align:start position:0% +kind of broader distribution of + + + align:start position:0% +kind of broader distribution of +resulting number of new infections right + + align:start position:0% +resulting number of new infections right + + + align:start position:0% +resulting number of new infections right +uh right so there's this classic thing + + align:start position:0% +uh right so there's this classic thing + + + align:start position:0% +uh right so there's this classic thing +of Typhoid Mary who was she was a nurse + + align:start position:0% +of Typhoid Mary who was she was a nurse + + + align:start position:0% +of Typhoid Mary who was she was a nurse +that okay now I'm I don't remember the + + align:start position:0% +that okay now I'm I don't remember the + + + align:start position:0% +that okay now I'm I don't remember the +story um yeah she was a cook a cook cook + + align:start position:0% +story um yeah she was a cook a cook cook + + + align:start position:0% +story um yeah she was a cook a cook cook +she cooked for a lot of people okay so + + align:start position:0% +she cooked for a lot of people okay so + + + align:start position:0% +she cooked for a lot of people okay so +right so she was somehow resistant + + align:start position:0% +right so she was somehow resistant + + + align:start position:0% +right so she was somehow resistant +typhoid but then uh but then she was + + align:start position:0% +typhoid but then uh but then she was + + + align:start position:0% +typhoid but then uh but then she was +cooking for other people and so then + + align:start position:0% +cooking for other people and so then + + + align:start position:0% +cooking for other people and so then +caused a bunch of infections is that + + align:start position:0% +caused a bunch of infections is that + + + align:start position:0% +caused a bunch of infections is that +okay U yes so this would be an example + + align:start position:0% +okay U yes so this would be an example + + + align:start position:0% +okay U yes so this would be an example +of a very infective individual right + + align:start position:0% +of a very infective individual right + + + align:start position:0% +of a very infective individual right +that's beyond the beyond the assumptions + + align:start position:0% +that's beyond the beyond the assumptions + + + align:start position:0% +that's beyond the beyond the assumptions +in this model right and as you can + + align:start position:0% +in this model right and as you can + + + align:start position:0% +in this model right and as you can +imagine if you have variations in this + + align:start position:0% +imagine if you have variations in this + + + align:start position:0% +imagine if you have variations in this +infectivity then what it does is it for + + align:start position:0% +infectivity then what it does is it for + + + align:start position:0% +infectivity then what it does is it for +a given R not so if you fix R not then + + align:start position:0% +a given R not so if you fix R not then + + + align:start position:0% +a given R not so if you fix R not then +you have a broader distributions of + + align:start position:0% +you have a broader distributions of + + + align:start position:0% +you have a broader distributions of +infectivities what it means is that a + + align:start position:0% +infectivities what it means is that a + + + align:start position:0% +infectivities what it means is that a +larger fraction of the infections will + + align:start position:0% +larger fraction of the infections will + + + align:start position:0% +larger fraction of the infections will +go extinct but those that get going will + + align:start position:0% +go extinct but those that get going will + + + align:start position:0% +go extinct but those that get going will +kind of be + + align:start position:0% +kind of be + + + align:start position:0% +kind of be +explosive okay if you're curious about + + align:start position:0% +explosive okay if you're curious about + + + align:start position:0% +explosive okay if you're curious about +these sorts of ideas you should you + + align:start position:0% +these sorts of ideas you should you + + + align:start position:0% +these sorts of ideas you should you +should look at the uh this optional + + align:start position:0% +should look at the uh this optional + + + align:start position:0% +should look at the uh this optional +reading paper that I I put out + + align:start position:0% +reading paper that I I put out + + + align:start position:0% +reading paper that I I put out +there okay all right so I just want to + + align:start position:0% +there okay all right so I just want to + + + align:start position:0% +there okay all right so I just want to +be clear this is geometric geometric + + align:start position:0% +be clear this is geometric geometric + + + align:start position:0% +be clear this is geometric geometric +number of new + + align:start position:0% +number of new + + + align:start position:0% +number of new +infections + + align:start position:0% +infections + + + align:start position:0% +infections +distribution uh of new + + align:start position:0% + + + + align:start position:0% + +infections + + align:start position:0% + + + + align:start position:0% + +yes all right so this this is the right + + align:start position:0% +yes all right so this this is the right + + + align:start position:0% +yes all right so this this is the right +so we're talking about the number of + + align:start position:0% +so we're talking about the number of + + + align:start position:0% +so we're talking about the number of +infections that result when you just add + + align:start position:0% +infections that result when you just add + + + align:start position:0% +infections that result when you just add +one infected individual to the + + align:start position:0% + + + + align:start position:0% + +population well well U we are not yet + + align:start position:0% +population well well U we are not yet + + + align:start position:0% +population well well U we are not yet +thinking about them although in in this + + align:start position:0% +thinking about them although in in this + + + align:start position:0% +thinking about them although in in this +case those are all those are also + + align:start position:0% +case those are all those are also + + + align:start position:0% +case those are all those are also +geometrically distributed but what you + + align:start position:0% +geometrically distributed but what you + + + align:start position:0% +geometrically distributed but what you +expect is that the mean of those things + + align:start position:0% +expect is that the mean of those things + + + align:start position:0% +expect is that the mean of those things +will change because the number of uh uh + + align:start position:0% +will change because the number of uh uh + + + align:start position:0% +will change because the number of uh uh +susceptible or whatnot individuals + + align:start position:0% +susceptible or whatnot individuals + + + align:start position:0% +susceptible or whatnot individuals +that's going to change right but uh so + + align:start position:0% +that's going to change right but uh so + + + align:start position:0% +that's going to change right but uh so +so the the mean the mean number is going + + align:start position:0% +so the the mean the mean number is going + + + align:start position:0% +so the the mean the mean number is going +to change but the distributions will + + align:start position:0% +to change but the distributions will + + + align:start position:0% +to change but the distributions will +still be geometric but in total that + + align:start position:0% +still be geometric but in total that + + + align:start position:0% +still be geometric but in total that +will be + + align:start position:0% +will be + + + align:start position:0% +will be +geom + + align:start position:0% + + + + align:start position:0% + +number no so just because each of these + + align:start position:0% +number no so just because each of these + + + align:start position:0% +number no so just because each of these +substeps is geometric does not mean that + + align:start position:0% +substeps is geometric does not mean that + + + align:start position:0% +substeps is geometric does not mean that +um that you end up with a geometric + + align:start position:0% +um that you end up with a geometric + + + align:start position:0% +um that you end up with a geometric +distribution indeed if you add up many + + align:start position:0% +distribution indeed if you add up many + + + align:start position:0% +distribution indeed if you add up many +let's say that I put in 20 infected + + align:start position:0% +let's say that I put in 20 infected + + + align:start position:0% +let's say that I put in 20 infected +individuals into the population and I + + align:start position:0% +individuals into the population and I + + + align:start position:0% +individuals into the population and I +ask what's going to be the distribution + + align:start position:0% +ask what's going to be the distribution + + + align:start position:0% +ask what's going to be the distribution +of the number of infections caused + + align:start position:0% +of the number of infections caused + + + align:start position:0% +of the number of infections caused +immediately from those 20 that's going + + align:start position:0% +immediately from those 20 that's going + + + align:start position:0% +immediately from those 20 that's going +to be + + align:start position:0% +to be + + + align:start position:0% +to be +what gamma and and for 20 or it's going + + align:start position:0% +what gamma and and for 20 or it's going + + + align:start position:0% +what gamma and and for 20 or it's going +to be basically gaan or okay well if I + + align:start position:0% +to be basically gaan or okay well if I + + + align:start position:0% +to be basically gaan or okay well if I +said 100 then you know definitely gaan + + align:start position:0% +said 100 then you know definitely gaan + + + align:start position:0% +said 100 then you know definitely gaan +yeah yeah it's a gamma distribution that + + align:start position:0% +yeah yeah it's a gamma distribution that + + + align:start position:0% +yeah yeah it's a gamma distribution that +looks very much like a gaussian in that + + align:start position:0% +looks very much like a gaussian in that + + + align:start position:0% +looks very much like a gaussian in that +case + + align:start position:0% +case + + + align:start position:0% +case +okay all + + align:start position:0% + + + + align:start position:0% + +right okay we so we've been talking + + align:start position:0% +right okay we so we've been talking + + + align:start position:0% +right okay we so we've been talking +about the definition of this rot but of + + align:start position:0% +about the definition of this rot but of + + + align:start position:0% +about the definition of this rot but of +course we should figure out what it uh + + align:start position:0% +course we should figure out what it uh + + + align:start position:0% +course we should figure out what it uh +what it is right we want to know R KN is + + align:start position:0% +what it is right we want to know R KN is + + + align:start position:0% +what it is right we want to know R KN is +equal to and what I'm going to tell you + + align:start position:0% +equal to and what I'm going to tell you + + + align:start position:0% +equal to and what I'm going to tell you +is that it + + align:start position:0% +is that it + + + align:start position:0% +is that it +is uh there's a one over U plus b okay + + align:start position:0% +is uh there's a one over U plus b okay + + + align:start position:0% +is uh there's a one over U plus b okay +but then there are some other terms and + + align:start position:0% +but then there are some other terms and + + + align:start position:0% +but then there are some other terms and +I have un fortunately lost my notes + + align:start position:0% +I have un fortunately lost my notes + + + align:start position:0% +I have un fortunately lost my notes +right so uh you guys are going to have + + align:start position:0% +right so uh you guys are going to have + + + align:start position:0% +right so uh you guys are going to have +to help me figure this out all right um + + align:start position:0% +to help me figure this out all right um + + + align:start position:0% +to help me figure this out all right um +and what you're going to do is you're + + align:start position:0% +and what you're going to do is you're + + + align:start position:0% +and what you're going to do is you're +going to take advantage of your cards + + align:start position:0% +going to take advantage of your cards + + + align:start position:0% +going to take advantage of your cards +and again put things in the numerators + + align:start position:0% +and again put things in the numerators + + + align:start position:0% +and again put things in the numerators +and put things in the denominators + + align:start position:0% +and put things in the denominators + + + align:start position:0% +and put things in the denominators +corresponding to how I'm supposed to + + align:start position:0% +corresponding to how I'm supposed to + + + align:start position:0% +corresponding to how I'm supposed to +fill out this equation all + + align:start position:0% +fill out this equation all + + + align:start position:0% +fill out this equation all +right you can start thinking about it + + align:start position:0% +right you can start thinking about it + + + align:start position:0% +right you can start thinking about it +while I give you the options + + align:start position:0% + + + + align:start position:0% + +okay so what uh although I guess you + + align:start position:0% +okay so what uh although I guess you + + + align:start position:0% +okay so what uh although I guess you +could recapitulate this by just putting + + align:start position:0% +could recapitulate this by just putting + + + align:start position:0% +could recapitulate this by just putting +B and C although maybe you need it more + + align:start position:0% +B and C although maybe you need it more + + + align:start position:0% +B and C although maybe you need it more +than once I all right do what you will + + align:start position:0% +than once I all right do what you will + + + align:start position:0% +than once I all right do what you will +do you understand the do you understand + + align:start position:0% +do you understand the do you understand + + + align:start position:0% +do you understand the do you understand +the question right I'm going to have to + + align:start position:0% +the question right I'm going to have to + + + align:start position:0% +the question right I'm going to have to +there going to be something else I'm + + align:start position:0% +there going to be something else I'm + + + align:start position:0% +there going to be something else I'm +going to put right here and I want to + + align:start position:0% +going to put right here and I want to + + + align:start position:0% +going to put right here and I want to +know there going to be some things in + + align:start position:0% +know there going to be some things in + + + align:start position:0% +know there going to be some things in +the numerator or some things in the + + align:start position:0% +the numerator or some things in the + + + align:start position:0% +the numerator or some things in the +denominator okay I'm going to give you + + align:start position:0% +denominator okay I'm going to give you + + + align:start position:0% +denominator okay I'm going to give you +uh I'm going to give you 30 seconds to + + align:start position:0% +uh I'm going to give you 30 seconds to + + + align:start position:0% +uh I'm going to give you 30 seconds to +think about it because this is uh it's + + align:start position:0% +think about it because this is uh it's + + + align:start position:0% +think about it because this is uh it's +important to be able to reason your way + + align:start position:0% +important to be able to reason your way + + + align:start position:0% +important to be able to reason your way +through this um + + align:start position:0% + + + + align:start position:0% + +all right do you need more + + align:start position:0% + + + + align:start position:0% + +time I'll give you another 15 seconds + + align:start position:0% + + + + align:start position:0% + +all right let's go ahead and vote all + + align:start position:0% +all right let's go ahead and vote all + + + align:start position:0% +all right let's go ahead and vote all +right ready three two + + align:start position:0% +right ready three two + + + align:start position:0% +right ready three two +one all right I think I like it we're + + align:start position:0% +one all right I think I like it we're + + + align:start position:0% +one all right I think I like it we're +really looking quite nice all right so + + align:start position:0% +really looking quite nice all right so + + + align:start position:0% +really looking quite nice all right so +there's a claim that it's going to be a + + align:start position:0% +there's a claim that it's going to be a + + + align:start position:0% +there's a claim that it's going to be a +d over B I.E that it's going to be we + + align:start position:0% +d over B I.E that it's going to be we + + + align:start position:0% +d over B I.E that it's going to be we +should be writing a beta K over + + align:start position:0% +should be writing a beta K over + + + align:start position:0% +should be writing a beta K over +you all right can somebody can somebody + + align:start position:0% +you all right can somebody can somebody + + + align:start position:0% +you all right can somebody can somebody +explain how they got + + align:start position:0% + + + + align:start position:0% + +there yes please um well it's it's going + + align:start position:0% +there yes please um well it's it's going + + + align:start position:0% +there yes please um well it's it's going +to be uh + + align:start position:0% +to be uh + + + align:start position:0% +to be uh +these these two okay yeah this this + + align:start position:0% +these these two okay yeah this this + + + align:start position:0% +these these two okay yeah this this +helped right okay good right so perfect + + align:start position:0% +helped right okay good right so perfect + + + align:start position:0% +helped right okay good right so perfect +so exactly so what this this thing is + + align:start position:0% +so exactly so what this this thing is + + + align:start position:0% +so exactly so what this this thing is +what what is this term + + align:start position:0% + + + + align:start position:0% + +here right uh and which means that this + + align:start position:0% +here right uh and which means that this + + + align:start position:0% +here right uh and which means that this +whole the one over it is it's the it's + + align:start position:0% +whole the one over it is it's the it's + + + align:start position:0% +whole the one over it is it's the it's +the expected lifetime of an infected + + align:start position:0% +the expected lifetime of an infected + + + align:start position:0% +the expected lifetime of an infected +individual right so we the definition of + + align:start position:0% +individual right so we the definition of + + + align:start position:0% +individual right so we the definition of +AR not is you put an infected individual + + align:start position:0% +AR not is you put an infected individual + + + align:start position:0% +AR not is you put an infected individual +into a population right of of + + align:start position:0% +into a population right of of + + + align:start position:0% +into a population right of of +susceptibles right now we want okay well + + align:start position:0% +susceptibles right now we want okay well + + + align:start position:0% +susceptibles right now we want okay well +there's a lifetime expected lifetime of + + align:start position:0% +there's a lifetime expected lifetime of + + + align:start position:0% +there's a lifetime expected lifetime of +this infected individual which is given + + align:start position:0% +this infected individual which is given + + + align:start position:0% +this infected individual which is given +by this okay and then we have to think + + align:start position:0% +by this okay and then we have to think + + + align:start position:0% +by this okay and then we have to think +about okay well what's the rate that + + align:start position:0% +about okay well what's the rate that + + + align:start position:0% +about okay well what's the rate that +we're going to be infecting individuals + + align:start position:0% +we're going to be infecting individuals + + + align:start position:0% +we're going to be infecting individuals +and that's going to be beta time + + align:start position:0% +and that's going to be beta time + + + align:start position:0% +and that's going to be beta time +x right but what we want to know is that + + align:start position:0% +x right but what we want to know is that + + + align:start position:0% +x right but what we want to know is that +is X before there we add any infection + + align:start position:0% +is X before there we add any infection + + + align:start position:0% +is X before there we add any infection +right and without any infection then we + + align:start position:0% +right and without any infection then we + + + align:start position:0% +right and without any infection then we +just have a rate of entry and then a + + align:start position:0% +just have a rate of entry and then a + + + align:start position:0% +just have a rate of entry and then a +death rate so it's just K Over + + align:start position:0% +death rate so it's just K Over + + + align:start position:0% +death rate so it's just K Over +U + + align:start position:0% +U + + + align:start position:0% +U +okay right now the key thing in all of + + align:start position:0% +okay right now the key thing in all of + + + align:start position:0% +okay right now the key thing in all of +these epidem ological models is whether + + align:start position:0% +these epidem ological models is whether + + + align:start position:0% +these epidem ological models is whether +this R KN is greater or less than one + + align:start position:0% +this R KN is greater or less than one + + + align:start position:0% +this R KN is greater or less than one +and that's going to tell us whether the + + align:start position:0% +and that's going to tell us whether the + + + align:start position:0% +and that's going to tell us whether the +disease becomes uh endemic or not right + + align:start position:0% +disease becomes uh endemic or not right + + + align:start position:0% +disease becomes uh endemic or not right +whether at steady state we have uh you + + align:start position:0% +whether at steady state we have uh you + + + align:start position:0% +whether at steady state we have uh you +know we have a population of infected + + align:start position:0% +know we have a population of infected + + + align:start position:0% +know we have a population of infected +individuals okay so are not greater than + + align:start position:0% +individuals okay so are not greater than + + + align:start position:0% +individuals okay so are not greater than +one means it's an endemic + + align:start position:0% +one means it's an endemic + + + align:start position:0% +one means it's an endemic +population okay + + align:start position:0% + + + + align:start position:0% + +all right now from uh in this model we + + align:start position:0% +all right now from uh in this model we + + + align:start position:0% +all right now from uh in this model we +can then + + align:start position:0% + + + + align:start position:0% + +ask um + + align:start position:0% + + + + align:start position:0% + +that's all right so do you like a Donuts + + align:start position:0% +that's all right so do you like a Donuts + + + align:start position:0% +that's all right so do you like a Donuts +B cupcakes or C carrots um yeah that's + + align:start position:0% +B cupcakes or C carrots um yeah that's + + + align:start position:0% +B cupcakes or C carrots um yeah that's +quite nice does anybody have any notion + + align:start position:0% +quite nice does anybody have any notion + + + align:start position:0% +quite nice does anybody have any notion +of of why somebody might have all right + + align:start position:0% +of of why somebody might have all right + + + align:start position:0% +of of why somebody might have all right +so Sam likes cupcakes okay that's good + + align:start position:0% +so Sam likes cupcakes okay that's good + + + align:start position:0% +so Sam likes cupcakes okay that's good +to know I I I yeah they're so pretty + + align:start position:0% +to know I I I yeah they're so pretty + + + align:start position:0% +to know I I I yeah they're so pretty +that I actually feel bad erasing it uh + + align:start position:0% +that I actually feel bad erasing it uh + + + align:start position:0% +that I actually feel bad erasing it uh +okay well we'll go ahead we'll we'll + + align:start position:0% +okay well we'll go ahead we'll we'll + + + align:start position:0% +okay well we'll go ahead we'll we'll +we'll leave it up there for a little bit + + align:start position:0% +we'll leave it up there for a little bit + + + align:start position:0% +we'll leave it up there for a little bit +longer so that um you know everybody can + + align:start position:0% +longer so that um you know everybody can + + + align:start position:0% +longer so that um you know everybody can +just smile because they know that the + + align:start position:0% +just smile because they know that the + + + align:start position:0% +just smile because they know that the +the drawing is back there + + align:start position:0% +the drawing is back there + + + align:start position:0% +the drawing is back there +um all right uh okay + + align:start position:0% +um all right uh okay + + + align:start position:0% +um all right uh okay +so in this model uh the fact that that R + + align:start position:0% +so in this model uh the fact that that R + + + align:start position:0% +so in this model uh the fact that that R +nod is this parameter that tells us + + align:start position:0% +nod is this parameter that tells us + + + align:start position:0% +nod is this parameter that tells us +about whether there's going to be an + + align:start position:0% +about whether there's going to be an + + + align:start position:0% +about whether there's going to be an +epidemic and then indeed whether later + + align:start position:0% +epidemic and then indeed whether later + + + align:start position:0% +epidemic and then indeed whether later +it's go the disease will be endemic + + align:start position:0% +it's go the disease will be endemic + + + align:start position:0% +it's go the disease will be endemic +right does that does that already tell + + align:start position:0% +right does that does that already tell + + + align:start position:0% +right does that does that already tell +us that R not is what's maximized by + + align:start position:0% + + + + align:start position:0% + +selection no right what was the key + + align:start position:0% +selection no right what was the key + + + align:start position:0% +selection no right what was the key +thing that uh that Martin does in the + + align:start position:0% +thing that uh that Martin does in the + + + align:start position:0% +thing that uh that Martin does in the +chapter in order to try to understand + + align:start position:0% +chapter in order to try to understand + + + align:start position:0% +chapter in order to try to understand +something about what strain is selected + + align:start position:0% +something about what strain is selected + + + align:start position:0% +something about what strain is selected +for + + align:start position:0% + + + + align:start position:0% + +yes right okay + + align:start position:0% +yes right okay + + + align:start position:0% +yes right okay +so yes although the the part of the + + align:start position:0% +so yes although the the part of the + + + align:start position:0% +so yes although the the part of the +chapter you're thinking about is I think + + align:start position:0% +chapter you're thinking about is I think + + + align:start position:0% +chapter you're thinking about is I think +this the second half is talking about + + align:start position:0% +this the second half is talking about + + + align:start position:0% +this the second half is talking about +super infection where there's all these + + align:start position:0% +super infection where there's all these + + + align:start position:0% +super infection where there's all these +different types and their craziness and + + align:start position:0% +different types and their craziness and + + + align:start position:0% +different types and their craziness and +so forth but um the initial insight + + align:start position:0% +so forth but um the initial insight + + + align:start position:0% +so forth but um the initial insight +about what is going to be selected for + + align:start position:0% +about what is going to be selected for + + + align:start position:0% +about what is going to be selected for +comes from a simpler model than + + align:start position:0% + + + + align:start position:0% + +that yeah so you don't have to think + + align:start position:0% +that yeah so you don't have to think + + + align:start position:0% +that yeah so you don't have to think +about all those many parasites and those + + align:start position:0% +about all those many parasites and those + + + align:start position:0% +about all those many parasites and those +triangles and all the craziness instead + + align:start position:0% +triangles and all the craziness instead + + + align:start position:0% +triangles and all the craziness instead +there was a simple simpler model that + + align:start position:0% +there was a simple simpler model that + + + align:start position:0% +there was a simple simpler model that +yeah you have multiple + + align:start position:0% +yeah you have multiple + + + align:start position:0% +yeah you have multiple +parasites only + + align:start position:0% +parasites only + + + align:start position:0% +parasites only +one that's right and so what what what + + align:start position:0% +one that's right and so what what what + + + align:start position:0% +one that's right and so what what what +he does is he just writes down kind of + + align:start position:0% +he does is he just writes down kind of + + + align:start position:0% +he does is he just writes down kind of +this model where he now allows kind of + + align:start position:0% +this model where he now allows kind of + + + align:start position:0% +this model where he now allows kind of +two different parasites with and to to + + align:start position:0% +two different parasites with and to to + + + align:start position:0% +two different parasites with and to to +take uh to to be spreading the + + align:start position:0% +take uh to to be spreading the + + + align:start position:0% +take uh to to be spreading the +population and and at the beginning well + + align:start position:0% +population and and at the beginning well + + + align:start position:0% +population and and at the beginning well +we'll write we'll write it down and we + + align:start position:0% +we'll write we'll write it down and we + + + align:start position:0% +we'll write we'll write it down and we +want to be clear about what there's a + + align:start position:0% +want to be clear about what there's a + + + align:start position:0% +want to be clear about what there's a +very important assumption that he makes + + align:start position:0% +very important assumption that he makes + + + align:start position:0% +very important assumption that he makes +okay what what he's going to find is + + align:start position:0% +okay what what he's going to find is + + + align:start position:0% +okay what what he's going to find is +that uh + + align:start position:0% +that uh + + + align:start position:0% +that uh +selection maximizes R not the ba the the + + align:start position:0% +selection maximizes R not the ba the the + + + align:start position:0% +selection maximizes R not the ba the the +basic reproductive + + align:start position:0% + + + + align:start position:0% + +ratio right R not and it's going to be + + align:start position:0% +ratio right R not and it's going to be + + + align:start position:0% +ratio right R not and it's going to be +in this model that I'm writing down now + + align:start position:0% +in this model that I'm writing down now + + + align:start position:0% +in this model that I'm writing down now +so there's this x dot and things look + + align:start position:0% +so there's this x dot and things look + + + align:start position:0% +so there's this x dot and things look +very similar + + align:start position:0% + + + + align:start position:0% + +all right now the question is what is + + align:start position:0% +all right now the question is what is + + + align:start position:0% +all right now the question is what is +the key assumption that we're making in + + align:start position:0% +the key assumption that we're making in + + + align:start position:0% +the key assumption that we're making in +writing down these equations + + align:start position:0% + + + + align:start position:0% + +thought that's right a host cannot be + + align:start position:0% +thought that's right a host cannot be + + + align:start position:0% +thought that's right a host cannot be +infected by more than one type of strain + + align:start position:0% +infected by more than one type of strain + + + align:start position:0% +infected by more than one type of strain +right so that's very very important okay + + align:start position:0% +right so that's very very important okay + + + align:start position:0% +right so that's very very important okay +so there's no super infection as they + + align:start position:0% +so there's no super infection as they + + + align:start position:0% +so there's no super infection as they +say + + align:start position:0% + + + + align:start position:0% + +okay and and depending on the disease + + align:start position:0% +okay and and depending on the disease + + + align:start position:0% +okay and and depending on the disease +this could either be a better or worse + + align:start position:0% +this could either be a better or worse + + + align:start position:0% +this could either be a better or worse +assumption right uh but then what what + + align:start position:0% +assumption right uh but then what what + + + align:start position:0% +assumption right uh but then what what +is it that is defining that these two + + align:start position:0% +is it that is defining that these two + + + align:start position:0% +is it that is defining that these two +strains then in what ways are they + + align:start position:0% + + + + align:start position:0% + +different their virulence is different + + align:start position:0% +different their virulence is different + + + align:start position:0% +different their virulence is different +right and the virulence here is and and + + align:start position:0% +right and the virulence here is and and + + + align:start position:0% +right and the virulence here is and and +what what is veilance again how it is + + align:start position:0% +what what is veilance again how it is + + + align:start position:0% +what what is veilance again how it is +but it's K that's right it's the + + align:start position:0% +but it's K that's right it's the + + + align:start position:0% +but it's K that's right it's the +additional mortality that is caused by + + align:start position:0% +additional mortality that is caused by + + + align:start position:0% +additional mortality that is caused by +the being infected by that by that + + align:start position:0% +the being infected by that by that + + + align:start position:0% +the being infected by that by that +strain is that the only way that they're + + align:start position:0% +strain is that the only way that they're + + + align:start position:0% +strain is that the only way that they're +different no what else is + + align:start position:0% +different no what else is + + + align:start position:0% +different no what else is +different the infectivity right so the + + align:start position:0% +different the infectivity right so the + + + align:start position:0% +different the infectivity right so the +betas are also different okay and right + + align:start position:0% +betas are also different okay and right + + + align:start position:0% +betas are also different okay and right +so it's important to not that in this + + align:start position:0% +so it's important to not that in this + + + align:start position:0% +so it's important to not that in this +model it's a very simple model but we're + + align:start position:0% +model it's a very simple model but we're + + + align:start position:0% +model it's a very simple model but we're +allowing the the strains to be different + + align:start position:0% +allowing the the strains to be different + + + align:start position:0% +allowing the the strains to be different +in these two ways okay and I think that + + align:start position:0% +in these two ways okay and I think that + + + align:start position:0% +in these two ways okay and I think that +it's it's very intuitive to just say oh + + align:start position:0% +it's it's very intuitive to just say oh + + + align:start position:0% +it's it's very intuitive to just say oh +well the beta should s you want to have + + align:start position:0% +well the beta should s you want to have + + + align:start position:0% +well the beta should s you want to have +a larger beta all of the things equal + + align:start position:0% +a larger beta all of the things equal + + + align:start position:0% +a larger beta all of the things equal +right because you would like to spread + + align:start position:0% +right because you would like to spread + + + align:start position:0% +right because you would like to spread +okay but uh it's I'd say maybe it's not + + align:start position:0% +okay but uh it's I'd say maybe it's not + + + align:start position:0% +okay but uh it's I'd say maybe it's not +as obvious what happens in terms of + + align:start position:0% +as obvious what happens in terms of + + + align:start position:0% +as obvious what happens in terms of +variance and then of course if you if + + align:start position:0% +variance and then of course if you if + + + align:start position:0% +variance and then of course if you if +you think about these two parameters in + + align:start position:0% +you think about these two parameters in + + + align:start position:0% +you think about these two parameters in +any biological context may be coupled in + + align:start position:0% +any biological context may be coupled in + + + align:start position:0% +any biological context may be coupled in +which case uh in which case things are + + align:start position:0% +which case uh in which case things are + + + align:start position:0% +which case uh in which case things are +more subtle + + align:start position:0% + + + + align:start position:0% + +okay yeah I think that this very this + + align:start position:0% +okay yeah I think that this very this + + + align:start position:0% +okay yeah I think that this very this +depends on the disease + + align:start position:0% + + + + align:start position:0% + +right so that that would be the that's + + align:start position:0% +right so that that would be the that's + + + align:start position:0% +right so that that would be the that's +kind of somehow the argument that um you + + align:start position:0% +kind of somehow the argument that um you + + + align:start position:0% +kind of somehow the argument that um you +know and I'd say that there there's + + align:start position:0% +know and I'd say that there there's + + + align:start position:0% +know and I'd say that there there's +there this + + align:start position:0% + + + + align:start position:0% + +can depending on whether you're thinking + + align:start position:0% +can depending on whether you're thinking + + + align:start position:0% +can depending on whether you're thinking +about the host at the level of an + + align:start position:0% +about the host at the level of an + + + align:start position:0% +about the host at the level of an +organism or a cell then then this would + + align:start position:0% +organism or a cell then then this would + + + align:start position:0% +organism or a cell then then this would +correspond to very different worlds um + + align:start position:0% +correspond to very different worlds um + + + align:start position:0% +correspond to very different worlds um +there so certainly in the context of uh + + align:start position:0% +there so certainly in the context of uh + + + align:start position:0% +there so certainly in the context of uh +viral infections in individual cells + + align:start position:0% +viral infections in individual cells + + + align:start position:0% +viral infections in individual cells +there are various mechanisms where if + + align:start position:0% +there are various mechanisms where if + + + align:start position:0% +there are various mechanisms where if +one strain kind of gets in then other + + align:start position:0% +one strain kind of gets in then other + + + align:start position:0% +one strain kind of gets in then other +strains have trouble getting in right uh + + align:start position:0% +strains have trouble getting in right uh + + + align:start position:0% +strains have trouble getting in right uh +and or if they do get in they can't do + + align:start position:0% +and or if they do get in they can't do + + + align:start position:0% +and or if they do get in they can't do +anything right so then so yeah so I + + align:start position:0% +anything right so then so yeah so I + + + align:start position:0% +anything right so then so yeah so I +think it really this really depends on + + align:start position:0% +think it really this really depends on + + + align:start position:0% +think it really this really depends on +the biology of the situation whether + + align:start position:0% +the biology of the situation whether + + + align:start position:0% +the biology of the situation whether +this is a reasonable assumption or not + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +okay all right so I'm not going to go + + align:start position:0% +okay all right so I'm not going to go + + + align:start position:0% +okay all right so I'm not going to go +through all of the math because it ends + + align:start position:0% +through all of the math because it ends + + + align:start position:0% +through all of the math because it ends +up being a little uh a little bit + + align:start position:0% +up being a little uh a little bit + + + align:start position:0% +up being a little uh a little bit +involved but there's an in I think it's + + align:start position:0% +involved but there's an in I think it's + + + align:start position:0% +involved but there's an in I think it's +the condition for the mutual + + align:start position:0% +the condition for the mutual + + + align:start position:0% +the condition for the mutual +invasibility of the two strains is um is + + align:start position:0% +invasibility of the two strains is um is + + + align:start position:0% +invasibility of the two strains is um is +a little bit subtle so I do want to I do + + align:start position:0% +a little bit subtle so I do want to I do + + + align:start position:0% +a little bit subtle so I do want to I do +want to talk about that a little bit + + align:start position:0% +want to talk about that a little bit + + + align:start position:0% +want to talk about that a little bit +okay right so in general in this + + align:start position:0% +okay right so in general in this + + + align:start position:0% +okay right so in general in this +model there is some + + align:start position:0% + + + + align:start position:0% + +equilibrium + + align:start position:0% + + + + align:start position:0% + +xar and Y + + align:start position:0% +xar and Y + + + align:start position:0% +xar and Y +star and indeed there will generally be + + align:start position:0% +star and indeed there will generally be + + + align:start position:0% +star and indeed there will generally be +damped oscillations to this + + align:start position:0% + + + + align:start position:0% + +equilibrium okay this is in the model + + align:start position:0% +equilibrium okay this is in the model + + + align:start position:0% +equilibrium okay this is in the model +where there's just a single strain + + align:start position:0% +where there's just a single strain + + + align:start position:0% +where there's just a single strain +that's described by su beta and some V + + align:start position:0% +that's described by su beta and some V + + + align:start position:0% +that's described by su beta and some V +okay of course you can also think about + + align:start position:0% +okay of course you can also think about + + + align:start position:0% +okay of course you can also think about +the equilibria E1 and E2 that would + + align:start position:0% +the equilibria E1 and E2 that would + + + align:start position:0% +the equilibria E1 and E2 that would +result uh when you have so so E1 is kind + + align:start position:0% +result uh when you have so so E1 is kind + + + align:start position:0% +result uh when you have so so E1 is kind +of what would happen it's the + + align:start position:0% +of what would happen it's the + + + align:start position:0% +of what would happen it's the +equilibrium when you have X star + + align:start position:0% +equilibrium when you have X star + + + align:start position:0% +equilibrium when you have X star +evaluated at you know for for the + + align:start position:0% +evaluated at you know for for the + + + align:start position:0% +evaluated at you know for for the +particular parameters of strain one I.E + + align:start position:0% +particular parameters of strain one I.E + + + align:start position:0% +particular parameters of strain one I.E +evaluated for beta 1 and for V1 xar and + + align:start position:0% +evaluated for beta 1 and for V1 xar and + + + align:start position:0% +evaluated for beta 1 and for V1 xar and +that's also y Star right whereas you + + align:start position:0% +that's also y Star right whereas you + + + align:start position:0% +that's also y Star right whereas you +would have a different equilibrium E2 uh + + align:start position:0% +would have a different equilibrium E2 uh + + + align:start position:0% +would have a different equilibrium E2 uh +you so this is X star and a y + + align:start position:0% +you so this is X star and a y + + + align:start position:0% +you so this is X star and a y +star evaluated at beta 2 and V2 do do + + align:start position:0% +star evaluated at beta 2 and V2 do do + + + align:start position:0% +star evaluated at beta 2 and V2 do do +you understand what what I'm saying so + + align:start position:0% +you understand what what I'm saying so + + + align:start position:0% +you understand what what I'm saying so +these are the equili you would have if + + align:start position:0% +these are the equili you would have if + + + align:start position:0% +these are the equili you would have if +this was the only strain that was + + align:start position:0% +this was the only strain that was + + + align:start position:0% +this was the only strain that was +present in the population or if or if + + align:start position:0% +present in the population or if or if + + + align:start position:0% +present in the population or if or if +this was the only strain in the pop + + align:start position:0% +this was the only strain in the pop + + + align:start position:0% +this was the only strain in the pop +okay now it's not obvious that those are + + align:start position:0% +okay now it's not obvious that those are + + + align:start position:0% +okay now it's not obvious that those are +the equilibria that result when you have + + align:start position:0% +the equilibria that result when you have + + + align:start position:0% +the equilibria that result when you have +both strains present in the population + + align:start position:0% +both strains present in the population + + + align:start position:0% +both strains present in the population +and but that's what we kind of want to + + align:start position:0% +and but that's what we kind of want to + + + align:start position:0% +and but that's what we kind of want to +try to figure out + + align:start position:0% +try to figure out + + + align:start position:0% +try to figure out +right but certainly if you only added + + align:start position:0% +right but certainly if you only added + + + align:start position:0% +right but certainly if you only added +strain one and you didn't add strain two + + align:start position:0% +strain one and you didn't add strain two + + + align:start position:0% +strain one and you didn't add strain two +you would come to the equilibrium E1 + + align:start position:0% + + + + align:start position:0% + +okay right so the question is how can we + + align:start position:0% +okay right so the question is how can we + + + align:start position:0% +okay right so the question is how can we +determine that if we start out at + + align:start position:0% +determine that if we start out at + + + align:start position:0% +determine that if we start out at +equilibrium E1 how is it we can + + align:start position:0% +equilibrium E1 how is it we can + + + align:start position:0% +equilibrium E1 how is it we can +determine what happens if we now add uh + + align:start position:0% +determine what happens if we now add uh + + + align:start position:0% +determine what happens if we now add uh +an infected individual uh but infected + + align:start position:0% +an infected individual uh but infected + + + align:start position:0% +an infected individual uh but infected +by strain + + align:start position:0% + + + + align:start position:0% + +two right so what we want to know is all + + align:start position:0% +two right so what we want to know is all + + + align:start position:0% +two right so what we want to know is all +right strain two can + + align:start position:0% + + + + align:start position:0% + +invade right and and really what we're + + align:start position:0% +invade right and and really what we're + + + align:start position:0% +invade right and and really what we're +we're thinking about is a situation + + align:start position:0% +we're thinking about is a situation + + + align:start position:0% +we're thinking about is a situation +these These are the equilibria if it's + + align:start position:0% +these These are the equilibria if it's + + + align:start position:0% +these These are the equilibria if it's +the case that R1 is greater than one and + + align:start position:0% +the case that R1 is greater than one and + + + align:start position:0% +the case that R1 is greater than one and +R2 is greater than one right because in + + align:start position:0% +R2 is greater than one right because in + + + align:start position:0% +R2 is greater than one right because in +some ways it's clear what happens if the + + align:start position:0% +some ways it's clear what happens if the + + + align:start position:0% +some ways it's clear what happens if the +if if both of the R1 and R2 is are less + + align:start position:0% +if if both of the R1 and R2 is are less + + + align:start position:0% +if if both of the R1 and R2 is are less +than one then what + + align:start position:0% + + + + align:start position:0% + +happens they both die out right if one + + align:start position:0% +happens they both die out right if one + + + align:start position:0% +happens they both die out right if one +of them is greater than one one's less + + align:start position:0% +of them is greater than one one's less + + + align:start position:0% +of them is greater than one one's less +than one then you know right it's you + + align:start position:0% +than one then you know right it's you + + + align:start position:0% +than one then you know right it's you +know the strain that's below one goes + + align:start position:0% +know the strain that's below one goes + + + align:start position:0% +know the strain that's below one goes +out you know so the only interesting or + + align:start position:0% +out you know so the only interesting or + + + align:start position:0% +out you know so the only interesting or +the only the only non-obvious question + + align:start position:0% +the only the only non-obvious question + + + align:start position:0% +the only the only non-obvious question +somehow is what happens if they're both + + align:start position:0% +somehow is what happens if they're both + + + align:start position:0% +somehow is what happens if they're both +larger uh larger than one right what + + align:start position:0% +larger uh larger than one right what + + + align:start position:0% +larger uh larger than one right what +that means is that for example if you if + + align:start position:0% +that means is that for example if you if + + + align:start position:0% +that means is that for example if you if +you had a population of susceptible + + align:start position:0% +you had a population of susceptible + + + align:start position:0% +you had a population of susceptible +individuals and you added one strain one + + align:start position:0% +individuals and you added one strain one + + + align:start position:0% +individuals and you added one strain one +one stra you know one infected strain + + align:start position:0% +one stra you know one infected strain + + + align:start position:0% +one stra you know one infected strain +one one infected by strain two right + + align:start position:0% +one one infected by strain two right + + + align:start position:0% +one one infected by strain two right +then in the deterministic kind of + + align:start position:0% +then in the deterministic kind of + + + align:start position:0% +then in the deterministic kind of +differential equation limit they would + + align:start position:0% +differential equation limit they would + + + align:start position:0% +differential equation limit they would +both + + align:start position:0% +both + + + align:start position:0% +both +spread right so they're both + + align:start position:0% +spread right so they're both + + + align:start position:0% +spread right so they're both +exponentially growing right does that + + align:start position:0% +exponentially growing right does that + + + align:start position:0% +exponentially growing right does that +already tell us that they're going + + align:start position:0% +already tell us that they're going + + + align:start position:0% +already tell us that they're going +you're going to have coexistence of the + + align:start position:0% +you're going to have coexistence of the + + + align:start position:0% +you're going to have coexistence of the +two + + align:start position:0% +two + + + align:start position:0% +two +strains no right it means that you know + + align:start position:0% +strains no right it means that you know + + + align:start position:0% +strains no right it means that you know +they're both exponentially spreading who + + align:start position:0% +they're both exponentially spreading who + + + align:start position:0% +they're both exponentially spreading who +knows what's going to happen later right + + align:start position:0% +knows what's going to happen later right + + + align:start position:0% +knows what's going to happen later right +and indeed uh what you can show is that + + align:start position:0% +and indeed uh what you can show is that + + + align:start position:0% +and indeed uh what you can show is that +only one of the two strains is going to + + align:start position:0% +only one of the two strains is going to + + + align:start position:0% +only one of the two strains is going to +win and it's the strain with the higher + + align:start position:0% +win and it's the strain with the higher + + + align:start position:0% +win and it's the strain with the higher +reproductive ratio the higher r notd or + + align:start position:0% +reproductive ratio the higher r notd or + + + align:start position:0% +reproductive ratio the higher r notd or +in this + + align:start position:0% +in this + + + align:start position:0% +in this +case okay all right so how is it that we + + align:start position:0% +case okay all right so how is it that we + + + align:start position:0% +case okay all right so how is it that we +can determine if strain two can invade + + align:start position:0% +can determine if strain two can invade + + + align:start position:0% +can determine if strain two can invade +equilibrium + + align:start position:0% +equilibrium + + + align:start position:0% +equilibrium +one it's if and only if something does + + align:start position:0% +one it's if and only if something does + + + align:start position:0% +one it's if and only if something does +anybody remember what this condition + + align:start position:0% +anybody remember what this condition + + + align:start position:0% +anybody remember what this condition +ended up being + + align:start position:0% + + + + align:start position:0% + +all right Y2 dot at E1 has to be + + align:start position:0% +all right Y2 dot at E1 has to be + + + align:start position:0% +all right Y2 dot at E1 has to be +positive right okay yes and and this + + align:start position:0% +positive right okay yes and and this + + + align:start position:0% +positive right okay yes and and this +ends up being equivalent I think to what + + align:start position:0% +ends up being equivalent I think to what + + + align:start position:0% +ends up being equivalent I think to what +he writes and okay so let's write what + + align:start position:0% +he writes and okay so let's write what + + + align:start position:0% +he writes and okay so let's write what +let's I'll write tell you what so the + + align:start position:0% +let's I'll write tell you what so the + + + align:start position:0% +let's I'll write tell you what so the +way he wrote it is that it's it's it's + + align:start position:0% +way he wrote it is that it's it's it's + + + align:start position:0% +way he wrote it is that it's it's it's +Y2 dot with respect to + + align:start position:0% +Y2 dot with respect to + + + align:start position:0% +Y2 dot with respect to +Y2 um but I think that this is really + + align:start position:0% +Y2 um but I think that this is really + + + align:start position:0% +Y2 um but I think that this is really +equivalent to what you said though um + + align:start position:0% +equivalent to what you said though um + + + align:start position:0% +equivalent to what you said though um +but it's a little bit + + align:start position:0% +but it's a little bit + + + align:start position:0% +but it's a little bit +um right because you said okay it's Y2 + + align:start position:0% +um right because you said okay it's Y2 + + + align:start position:0% +um right because you said okay it's Y2 +dot has to be something right but then + + align:start position:0% +dot has to be something right but then + + + align:start position:0% +dot has to be something right but then +Y2 dot evaluated what and you would say + + align:start position:0% +Y2 dot evaluated what and you would say + + + align:start position:0% +Y2 dot evaluated what and you would say +oh evaluated at E1 but then at E1 yeah + + align:start position:0% +oh evaluated at E1 but then at E1 yeah + + + align:start position:0% +oh evaluated at E1 but then at E1 yeah +so what is Y2 dot evaluated at + + align:start position:0% +so what is Y2 dot evaluated at + + + align:start position:0% +so what is Y2 dot evaluated at +E1 zero right because at E1 there's zero + + align:start position:0% +E1 zero right because at E1 there's zero + + + align:start position:0% +E1 zero right because at E1 there's zero +Y2 so then of course Y2 do is zero right + + align:start position:0% +Y2 so then of course Y2 do is zero right + + + align:start position:0% +Y2 so then of course Y2 do is zero right +so it's almost what you want but not + + align:start position:0% +so it's almost what you want but not + + + align:start position:0% +so it's almost what you want but not +quite right and so this condition which + + align:start position:0% +quite right and so this condition which + + + align:start position:0% +quite right and so this condition which +looks very weird it's really saying that + + align:start position:0% +looks very weird it's really saying that + + + align:start position:0% +looks very weird it's really saying that +right if we are at we're at E1 at E1 so + + align:start position:0% +right if we are at we're at E1 at E1 so + + + align:start position:0% +right if we are at we're at E1 at E1 so +there's no um infected uh type two + + align:start position:0% +there's no um infected uh type two + + + align:start position:0% +there's no um infected uh type two +infections right what we want to do is + + align:start position:0% +infections right what we want to do is + + + align:start position:0% +infections right what we want to do is +kind of add a little bit of Y2 and then + + align:start position:0% +kind of add a little bit of Y2 and then + + + align:start position:0% +kind of add a little bit of Y2 and then +we want to ask what is Y2 dot right this + + align:start position:0% +we want to ask what is Y2 dot right this + + + align:start position:0% +we want to ask what is Y2 dot right this +derivative evaluated E1 somehow allows + + align:start position:0% +derivative evaluated E1 somehow allows + + + align:start position:0% +derivative evaluated E1 somehow allows +you to do + + align:start position:0% +you to do + + + align:start position:0% +you to do +that right and do we want this to be + + align:start position:0% +that right and do we want this to be + + + align:start position:0% +that right and do we want this to be +greater than zero or less than zero + + align:start position:0% +greater than zero or less than zero + + + align:start position:0% +greater than zero or less than zero +right we're going to do ver uh verbal + + align:start position:0% +right we're going to do ver uh verbal + + + align:start position:0% +right we're going to do ver uh verbal +answer ready three two one greater right + + align:start position:0% +answer ready three two one greater right + + + align:start position:0% +answer ready three two one greater right +because if it's saying you add a Y2 you + + align:start position:0% +because if it's saying you add a Y2 you + + + align:start position:0% +because if it's saying you add a Y2 you +want Y2 to start growing + + align:start position:0% +want Y2 to start growing + + + align:start position:0% +want Y2 to start growing +okay uh so you want this thing to be + + align:start position:0% +okay uh so you want this thing to be + + + align:start position:0% +okay uh so you want this thing to be +greater than zero and um this looks + + align:start position:0% +greater than zero and um this looks + + + align:start position:0% +greater than zero and um this looks +really crazy but it's actually pretty + + align:start position:0% +really crazy but it's actually pretty + + + align:start position:0% +really crazy but it's actually pretty +easy to do because you take the + + align:start position:0% +easy to do because you take the + + + align:start position:0% +easy to do because you take the +derivative of this thing with respect to + + align:start position:0% +derivative of this thing with respect to + + + align:start position:0% +derivative of this thing with respect to +Y2 and you just get the thing in + + align:start position:0% +Y2 and you just get the thing in + + + align:start position:0% +Y2 and you just get the thing in +parentheses right but you evaluate it at + + align:start position:0% +parentheses right but you evaluate it at + + + align:start position:0% +parentheses right but you evaluate it at +E1 so it's it's beta 2 and this is X + + align:start position:0% +E1 so it's it's beta 2 and this is X + + + align:start position:0% +E1 so it's it's beta 2 and this is X +star at um at + + align:start position:0% +star at um at + + + align:start position:0% +star at um at +E1 right minus uus V2 and this thing has + + align:start position:0% +E1 right minus uus V2 and this thing has + + + align:start position:0% +E1 right minus uus V2 and this thing has +to be greater than zero + + align:start position:0% +to be greater than zero + + + align:start position:0% +to be greater than zero +okay + + align:start position:0% +okay + + + align:start position:0% +okay +but this + + align:start position:0% +but this + + + align:start position:0% +but this +is X at E1 that's U plus V1 divid beta 1 + + align:start position:0% +is X at E1 that's U plus V1 divid beta 1 + + + align:start position:0% +is X at E1 that's U plus V1 divid beta 1 +okay so what we have is a beta 2 then U + + align:start position:0% +okay so what we have is a beta 2 then U + + + align:start position:0% +okay so what we have is a beta 2 then U ++ + + align:start position:0% ++ + + + align:start position:0% ++ +V1 divid beta + + align:start position:0% +V1 divid beta + + + align:start position:0% +V1 divid beta +1 and this thing has to be greater than + + align:start position:0% +1 and this thing has to be greater than + + + align:start position:0% +1 and this thing has to be greater than +and we'll move this over to the other + + align:start position:0% +and we'll move this over to the other + + + align:start position:0% +and we'll move this over to the other +side U + + + align:start position:0% +side U + + + + align:start position:0% +side U + +V2 okay so this is not so horrible right + + align:start position:0% +V2 okay so this is not so horrible right + + + align:start position:0% +V2 okay so this is not so horrible right +there's a u plus V1 beta 1 right I just + + align:start position:0% +there's a u plus V1 beta 1 right I just + + + align:start position:0% +there's a u plus V1 beta 1 right I just +want to make sure I write U plus + + align:start position:0% +want to make sure I write U plus + + + align:start position:0% +want to make sure I write U plus +V1 okay we have to put these in the + + align:start position:0% +V1 okay we have to put these in the + + + align:start position:0% +V1 okay we have to put these in the +denominators now somehow + + align:start position:0% +denominators now somehow + + + align:start position:0% +denominators now somehow +um okay so we'll put divide by both of + + align:start position:0% +um okay so we'll put divide by both of + + + align:start position:0% +um okay so we'll put divide by both of +these things so we have a 1 divid a u + + + align:start position:0% +these things so we have a 1 divid a u + + + + align:start position:0% +these things so we have a 1 divid a u + +V2 1id U + + + align:start position:0% +V2 1id U + + + + align:start position:0% +V2 1id U + +V1 right so we put these things in the + + align:start position:0% +V1 right so we put these things in the + + + align:start position:0% +V1 right so we put these things in the +denominator right and then now the beta + + align:start position:0% +denominator right and then now the beta + + + align:start position:0% +denominator right and then now the beta +one's going to come up here so we have a + + align:start position:0% +one's going to come up here so we have a + + + align:start position:0% +one's going to come up here so we have a +a beta 1 and a beta 2 and there still is + + align:start position:0% +a beta 1 and a beta 2 and there still is + + + align:start position:0% +a beta 1 and a beta 2 and there still is +a greater than sign did I did I screw + + align:start position:0% +a greater than sign did I did I screw + + + align:start position:0% +a greater than sign did I did I screw +anything up + + align:start position:0% +anything up + + + align:start position:0% +anything up +yet maybe no all + + align:start position:0% +yet maybe no all + + + align:start position:0% +yet maybe no all +right okay now we can do something + + align:start position:0% +right okay now we can do something + + + align:start position:0% +right okay now we can do something +wonderful which is we can just multiply + + align:start position:0% +wonderful which is we can just multiply + + + align:start position:0% +wonderful which is we can just multiply +by Kid by U + + align:start position:0% + + + + align:start position:0% + +right okay so what does this say + + align:start position:0% + + + + align:start position:0% + +R2 R2 is greater than R1 + + align:start position:0% + + + + align:start position:0% + +right and what were we trying to + + align:start position:0% + + + + align:start position:0% + +calculate how did we get started on this + + align:start position:0% + + + + align:start position:0% + +math right we wanted to ask strain two + + align:start position:0% +math right we wanted to ask strain two + + + align:start position:0% +math right we wanted to ask strain two +can invade the equilibrium one if and + + align:start position:0% +can invade the equilibrium one if and + + + align:start position:0% +can invade the equilibrium one if and +only + + align:start position:0% + + + + align:start position:0% + +if oh no no oh sorry R2 is greater than + + align:start position:0% +if oh no no oh sorry R2 is greater than + + + align:start position:0% +if oh no no oh sorry R2 is greater than +all right + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +now that's interesting right so that's + + align:start position:0% +now that's interesting right so that's + + + align:start position:0% +now that's interesting right so that's +saying that if you start out with the + + align:start position:0% +saying that if you start out with the + + + align:start position:0% +saying that if you start out with the +endemic strain one and you add the uh + + align:start position:0% +endemic strain one and you add the uh + + + align:start position:0% +endemic strain one and you add the uh +strain two in there it's going to be + + align:start position:0% +strain two in there it's going to be + + + align:start position:0% +strain two in there it's going to be +able to invade if its R2 is greater than + + align:start position:0% +able to invade if its R2 is greater than + + + align:start position:0% +able to invade if its R2 is greater than +R1 that's not obvious right because R2 + + align:start position:0% +R1 that's not obvious right because R2 + + + align:start position:0% +R1 that's not obvious right because R2 +and R1 that was tell that was telling us + + align:start position:0% +and R1 that was tell that was telling us + + + align:start position:0% +and R1 that was tell that was telling us +some a different situation right that + + align:start position:0% +some a different situation right that + + + align:start position:0% +some a different situation right that +was telling us about what happens when + + align:start position:0% +was telling us about what happens when + + + align:start position:0% +was telling us about what happens when +you add those infected uh individuals + + align:start position:0% +you add those infected uh individuals + + + align:start position:0% +you add those infected uh individuals +into a population of susceptibles okay + + align:start position:0% +into a population of susceptibles okay + + + align:start position:0% +into a population of susceptibles okay +but this also ends up telling us about + + align:start position:0% +but this also ends up telling us about + + + align:start position:0% +but this also ends up telling us about +the um about what happens when the + + align:start position:0% +the um about what happens when the + + + align:start position:0% +the um about what happens when the +strains are competing against each other + + align:start position:0% +strains are competing against each other + + + align:start position:0% +strains are competing against each other +right I think so this is I think it's + + align:start position:0% +right I think so this is I think it's + + + align:start position:0% +right I think so this is I think it's +not it's so simple that it feels trivial + + align:start position:0% +not it's so simple that it feels trivial + + + align:start position:0% +not it's so simple that it feels trivial +but + + align:start position:0% +but + + + align:start position:0% +but +I I I'm sure that if you understood it + + align:start position:0% +I I I'm sure that if you understood it + + + align:start position:0% +I I I'm sure that if you understood it +well enough it would be trivial but + + align:start position:0% +well enough it would be trivial but + + + align:start position:0% +well enough it would be trivial but +you'd have to think about it more than I + + align:start position:0% +you'd have to think about it more than I + + + align:start position:0% +you'd have to think about it more than I +have okay so I think this is surprising + + align:start position:0% +have okay so I think this is surprising + + + align:start position:0% +have okay so I think this is surprising +now you can also ask the same question + + align:start position:0% +now you can also ask the same question + + + align:start position:0% +now you can also ask the same question +which is that um + + align:start position:0% +which is that um + + + align:start position:0% +which is that um +is strain two can um about whether + + align:start position:0% +is strain two can um about whether + + + align:start position:0% +is strain two can um about whether +strain one can evade strain two right + + align:start position:0% +strain one can evade strain two right + + + align:start position:0% +strain one can evade strain two right +and that is kind of the same thing you + + align:start position:0% +and that is kind of the same thing you + + + align:start position:0% +and that is kind of the same thing you +know so it all comes down to the + + align:start position:0% +know so it all comes down to the + + + align:start position:0% +know so it all comes down to the +orderings of R2 and + + align:start position:0% +orderings of R2 and + + + align:start position:0% +orderings of R2 and +R1 okay and uh what you what you find is + + align:start position:0% +R1 okay and uh what you what you find is + + + align:start position:0% +R1 okay and uh what you what you find is +that uh is that strain two in this if + + align:start position:0% +that uh is that strain two in this if + + + align:start position:0% +that uh is that strain two in this if +this condition is satisfied strain two + + align:start position:0% +this condition is satisfied strain two + + + align:start position:0% +this condition is satisfied strain two +will drive strain one uh out of the + + align:start position:0% + + + + align:start position:0% + +population right so if they're the same + + align:start position:0% +population right so if they're the same + + + align:start position:0% +population right so if they're the same +then you can get + + align:start position:0% +then you can get + + + align:start position:0% +then you can get +coexistence um but it's it's as uh as + + align:start position:0% +coexistence um but it's it's as uh as + + + align:start position:0% +coexistence um but it's it's as uh as +Martin says it's non-generic in the + + align:start position:0% +Martin says it's non-generic in the + + + align:start position:0% +Martin says it's non-generic in the +sense that it's kind of a coincidence or + + align:start position:0% +sense that it's kind of a coincidence or + + + align:start position:0% +sense that it's kind of a coincidence or +you know it's of measure zero the + + align:start position:0% +you know it's of measure zero the + + + align:start position:0% +you know it's of measure zero the +situations in which the two will um have + + align:start position:0% +situations in which the two will um have + + + align:start position:0% +situations in which the two will um have +the same you know R + + align:start position:0% +the same you know R + + + align:start position:0% +the same you know R +parameters right but um but of course + + align:start position:0% +parameters right but um but of course + + + align:start position:0% +parameters right but um but of course +you can imagine just like we talked + + align:start position:0% +you can imagine just like we talked + + + align:start position:0% +you can imagine just like we talked +about this neutral Evolution business + + align:start position:0% +about this neutral Evolution business + + + align:start position:0% +about this neutral Evolution business +things are nearly neutral and so forth + + align:start position:0% +things are nearly neutral and so forth + + + align:start position:0% +things are nearly neutral and so forth +you can kind of invoke similar ideas + + align:start position:0% +you can kind of invoke similar ideas + + + align:start position:0% +you can kind of invoke similar ideas +because you can imagine that as these + + align:start position:0% +because you can imagine that as these + + + align:start position:0% +because you can imagine that as these +two become closer and closer to each + + align:start position:0% +two become closer and closer to each + + + align:start position:0% +two become closer and closer to each +other it's going to take longer and + + align:start position:0% +other it's going to take longer and + + + align:start position:0% +other it's going to take longer and +longer for the um for the sort of more + + align:start position:0% +longer for the um for the sort of more + + + align:start position:0% +longer for the um for the sort of more +fit strain to out compete the less fit + + align:start position:0% +fit strain to out compete the less fit + + + align:start position:0% +fit strain to out compete the less fit +strain + + align:start position:0% +strain + + + align:start position:0% +strain +okay right now um even though this is + + align:start position:0% +okay right now um even though this is + + + align:start position:0% +okay right now um even though this is +such a + + align:start position:0% +such a + + + align:start position:0% +such a +simple condition and the r parameters + + align:start position:0% +simple condition and the r parameters + + + align:start position:0% +simple condition and the r parameters +have such a simple kind of uh physical + + align:start position:0% +have such a simple kind of uh physical + + + align:start position:0% +have such a simple kind of uh physical +uh kind of origin or mathematical origin + + align:start position:0% +uh kind of origin or mathematical origin + + + align:start position:0% +uh kind of origin or mathematical origin +um the actual expression for the RS is + + align:start position:0% +um the actual expression for the RS is + + + align:start position:0% +um the actual expression for the RS is +is kind of complicated right so again + + align:start position:0% +is kind of complicated right so again + + + align:start position:0% +is kind of complicated right so again +it's it's a combination of all of these + + align:start position:0% +it's it's a combination of all of these + + + align:start position:0% +it's it's a combination of all of these +different parameters where it's the + + align:start position:0% +different parameters where it's the + + + align:start position:0% +different parameters where it's the +beta1 V1 or beta 2 + + align:start position:0% +beta1 V1 or beta 2 + + + align:start position:0% +beta1 V1 or beta 2 +V2 + + align:start position:0% +V2 + + + align:start position:0% +V2 +okay right so from from this you can + + align:start position:0% +okay right so from from this you can + + + align:start position:0% +okay right so from from this you can +start to think about + + align:start position:0% +start to think about + + + align:start position:0% +start to think about +um what will be okay + + align:start position:0% +um what will be okay + + + align:start position:0% +um what will be okay +which all + + align:start position:0% +which all + + + align:start position:0% +which all +right which board do you think is less + + align:start position:0% +right which board do you think is less + + + align:start position:0% +right which board do you think is less +uh least useful + + align:start position:0% + + + + align:start position:0% + +no all right well I don't like this one + + align:start position:0% +no all right well I don't like this one + + + align:start position:0% +no all right well I don't like this one +anymore uh but in particular we want to + + align:start position:0% +anymore uh but in particular we want to + + + align:start position:0% +anymore uh but in particular we want to +say something about the evolution of + + align:start position:0% +say something about the evolution of + + + align:start position:0% +say something about the evolution of +variance okay in this model and and what + + align:start position:0% +variance okay in this model and and what + + + align:start position:0% +variance okay in this model and and what +the expectation is okay so what we're + + align:start position:0% +the expectation is okay so what we're + + + align:start position:0% +the expectation is okay so what we're +going to do is I'm going to give you + + align:start position:0% +going to do is I'm going to give you + + + align:start position:0% +going to do is I'm going to give you +some different situations in terms of + + align:start position:0% +some different situations in terms of + + + align:start position:0% +some different situations in terms of +how the uh infectivity uh depends upon + + align:start position:0% +how the uh infectivity uh depends upon + + + align:start position:0% +how the uh infectivity uh depends upon +the virulence and then you get guys will + + align:start position:0% +the virulence and then you get guys will + + + align:start position:0% +the virulence and then you get guys will +get to tell me what um how the virence + + align:start position:0% +get to tell me what um how the virence + + + align:start position:0% +get to tell me what um how the virence +will + + align:start position:0% + + + + align:start position:0% + +evolve + + align:start position:0% + + + + align:start position:0% + +okay all + + align:start position:0% + + + + align:start position:0% + +right right this is a varul + + align:start position:0% + + + + align:start position:0% + +V all + + align:start position:0% + + + + align:start position:0% + +right all right so first situation is if + + align:start position:0% +right all right so first situation is if + + + align:start position:0% +right all right so first situation is if +um + + align:start position:0% +um + + + align:start position:0% +um +beta as a function of the veilance so + + align:start position:0% +beta as a function of the veilance so + + + align:start position:0% +beta as a function of the veilance so +the the infectivity as a function of + + align:start position:0% +the the infectivity as a function of + + + align:start position:0% +the the infectivity as a function of +veilance is some uh we'll say some beta + + align:start position:0% +veilance is some uh we'll say some beta + + + align:start position:0% +veilance is some uh we'll say some beta +knot right so it doesn't so first the + + align:start position:0% +knot right so it doesn't so first the + + + align:start position:0% +knot right so it doesn't so first the +question is if the infectivity does not + + align:start position:0% +question is if the infectivity does not + + + align:start position:0% +question is if the infectivity does not +depend upon the + + align:start position:0% + + + + align:start position:0% + +virulence right where will the where + + align:start position:0% +virulence right where will the where + + + align:start position:0% +virulence right where will the where +will variance go + + align:start position:0% + + + + align:start position:0% + +to you have + + align:start position:0% +to you have + + + align:start position:0% +to you have +equation various places that'll help you + + align:start position:0% + + + + align:start position:0% + +all right do you need more time no all + + align:start position:0% +all right do you need more time no all + + + align:start position:0% +all right do you need more time no all +right ready three two + + align:start position:0% + + + + align:start position:0% + +one okay we got many A's that's + + align:start position:0% + + + + align:start position:0% + +great right so if it's the case that it + + align:start position:0% +great right so if it's the case that it + + + align:start position:0% +great right so if it's the case that it +doesn't matter how you know that the the + + align:start position:0% +doesn't matter how you know that the the + + + align:start position:0% +doesn't matter how you know that the the +parasite regardless of how rapidly it's + + align:start position:0% +parasite regardless of how rapidly it's + + + align:start position:0% +parasite regardless of how rapidly it's +killing the individual if it has the + + align:start position:0% +killing the individual if it has the + + + align:start position:0% +killing the individual if it has the +same rate of getting to other + + align:start position:0% +same rate of getting to other + + + align:start position:0% +same rate of getting to other +individuals that case we want to make + + align:start position:0% +individuals that case we want to make + + + align:start position:0% +individuals that case we want to make +the rot get as uh as large as possible + + align:start position:0% +the rot get as uh as large as possible + + + align:start position:0% +the rot get as uh as large as possible +so then we make V go as small as + + align:start position:0% +so then we make V go as small as + + + align:start position:0% +so then we make V go as small as +possible right that's the mathematical + + align:start position:0% +possible right that's the mathematical + + + align:start position:0% +possible right that's the mathematical +thing you can look at and why does this + + align:start position:0% +thing you can look at and why does this + + + align:start position:0% +thing you can look at and why does this +make + + align:start position:0% + + + + align:start position:0% + +sense yeah right so from the standpoint + + align:start position:0% +sense yeah right so from the standpoint + + + align:start position:0% +sense yeah right so from the standpoint +of of the uh of the parasite if uh in + + align:start position:0% +of of the uh of the parasite if uh in + + + align:start position:0% +of of the uh of the parasite if uh in +this situation where the infectivity + + align:start position:0% +this situation where the infectivity + + + align:start position:0% +this situation where the infectivity +doesn't depend on the virulence well in + + align:start position:0% +doesn't depend on the virulence well in + + + align:start position:0% +doesn't depend on the virulence well in +that case uh you don't want to kill your + + align:start position:0% +that case uh you don't want to kill your + + + align:start position:0% +that case uh you don't want to kill your +host because uh the longer that the host + + align:start position:0% +host because uh the longer that the host + + + align:start position:0% +host because uh the longer that the host +lives the more other individuals you can + + align:start position:0% +lives the more other individuals you can + + + align:start position:0% +lives the more other individuals you can +infect + + align:start position:0% +infect + + + align:start position:0% +infect +right and this is the basic kind of + + align:start position:0% +right and this is the basic kind of + + + align:start position:0% +right and this is the basic kind of +statement underlying the the statement + + align:start position:0% +statement underlying the the statement + + + align:start position:0% +statement underlying the the statement +that you often hear that a well-adapted + + align:start position:0% +that you often hear that a well-adapted + + + align:start position:0% +that you often hear that a well-adapted +parasite does not harm its + + align:start position:0% +parasite does not harm its + + + align:start position:0% +parasite does not harm its +host and I think that this is one of + + align:start position:0% +host and I think that this is one of + + + align:start position:0% +host and I think that this is one of +those things + + align:start position:0% +those things + + + align:start position:0% +those things +that you can write down a simple model + + align:start position:0% +that you can write down a simple model + + + align:start position:0% +that you can write down a simple model +and convince yourself should be true uh + + align:start position:0% +and convince yourself should be true uh + + + align:start position:0% +and convince yourself should be true uh +you can maybe find a few case studies + + align:start position:0% +you can maybe find a few case studies + + + align:start position:0% +you can maybe find a few case studies +where it seems to be true uh but then uh + + align:start position:0% +where it seems to be true uh but then uh + + + align:start position:0% +where it seems to be true uh but then uh +you always have to be careful about what + + align:start position:0% +you always have to be careful about what + + + align:start position:0% +you always have to be careful about what +you know how strongly you should believe + + align:start position:0% +you know how strongly you should believe + + + align:start position:0% +you know how strongly you should believe +such a statement based on those kinds of + + align:start position:0% +such a statement based on those kinds of + + + align:start position:0% +such a statement based on those kinds of +evidence right because it's a very + + align:start position:0% +evidence right because it's a very + + + align:start position:0% +evidence right because it's a very +simple + + align:start position:0% +simple + + + align:start position:0% +simple +model it's a making assumption that is + + align:start position:0% +model it's a making assumption that is + + + align:start position:0% +model it's a making assumption that is +very likely not true and actually many + + align:start position:0% +very likely not true and actually many + + + align:start position:0% +very likely not true and actually many +assumptions that are very very likely + + align:start position:0% +assumptions that are very very likely + + + align:start position:0% +assumptions that are very very likely +not true and there are counter examples + + align:start position:0% +not true and there are counter examples + + + align:start position:0% +not true and there are counter examples +right so Martin talks about malaria + + align:start position:0% +right so Martin talks about malaria + + + align:start position:0% +right so Martin talks about malaria +which which is which humans have had for + + align:start position:0% +which which is which humans have had for + + + align:start position:0% +which which is which humans have had for +uh millions of years and uh and still + + align:start position:0% +uh millions of years and uh and still + + + align:start position:0% +uh millions of years and uh and still +caus us a lot of problems + + align:start position:0% +caus us a lot of problems + + + align:start position:0% +caus us a lot of problems +right and so you might imagine that well + + align:start position:0% +right and so you might imagine that well + + + align:start position:0% +right and so you might imagine that well +what would happen if um if the + + align:start position:0% +what would happen if um if the + + + align:start position:0% +what would happen if um if the +infectivity is a function of the + + align:start position:0% +infectivity is a function of the + + + align:start position:0% +infectivity is a function of the +veilance maybe it's just proportional to + + align:start position:0% +veilance maybe it's just proportional to + + + align:start position:0% +veilance maybe it's just proportional to +the variance right and this kind of + + align:start position:0% +the variance right and this kind of + + + align:start position:0% +the variance right and this kind of +would make me make sense because you + + align:start position:0% +would make me make sense because you + + + align:start position:0% +would make me make sense because you +could say oh well let's imagine that the + + align:start position:0% +could say oh well let's imagine that the + + + align:start position:0% +could say oh well let's imagine that the +number of viruses in the host right that + + align:start position:0% +number of viruses in the host right that + + + align:start position:0% +number of viruses in the host right that +somehow the the additional ver the + + align:start position:0% +somehow the the additional ver the + + + align:start position:0% +somehow the the additional ver the +veillance is just proportional to that + + align:start position:0% +veillance is just proportional to that + + + align:start position:0% +veillance is just proportional to that +number and also the infectivity is + + align:start position:0% +number and also the infectivity is + + + align:start position:0% +number and also the infectivity is +proportional to that number right in + + align:start position:0% +proportional to that number right in + + + align:start position:0% +proportional to that number right in +that case infectivity will just scale + + align:start position:0% +that case infectivity will just scale + + + align:start position:0% +that case infectivity will just scale +linearly with v right does that it's + + align:start position:0% +linearly with v right does that it's + + + align:start position:0% +linearly with v right does that it's +kind of another reasonable world + + align:start position:0% +kind of another reasonable world + + + align:start position:0% +kind of another reasonable world +right okay so in this situation where + + align:start position:0% +right okay so in this situation where + + + align:start position:0% +right okay so in this situation where +does uh where does the variance of all + + align:start position:0% +does uh where does the variance of all + + + align:start position:0% +does uh where does the variance of all +to all right we'll um think about this + + align:start position:0% +to all right we'll um think about this + + + align:start position:0% +to all right we'll um think about this +for 10 seconds + + align:start position:0% + + + + align:start position:0% + +all right ready three two + + align:start position:0% + + + + align:start position:0% + +one okay all right so now we actually + + align:start position:0% +one okay all right so now we actually + + + align:start position:0% +one okay all right so now we actually +have votes that are pretty distributed + + align:start position:0% +have votes that are pretty distributed + + + align:start position:0% +have votes that are pretty distributed +around + + align:start position:0% +around + + + align:start position:0% +around +um okay I I I'm just going to write down + + align:start position:0% +um okay I I I'm just going to write down + + + align:start position:0% +um okay I I I'm just going to write down +the expression just cuz I think we can + + align:start position:0% +the expression just cuz I think we can + + + align:start position:0% +the expression just cuz I think we can +do it quickly right so now the r KN is + + align:start position:0% +do it quickly right so now the r KN is + + + align:start position:0% +do it quickly right so now the r KN is +going to be given by we're going to be + + align:start position:0% +going to be given by we're going to be + + + align:start position:0% +going to be given by we're going to be +thinking about a one there's a u plus v + + align:start position:0% +thinking about a one there's a u plus v + + + align:start position:0% +thinking about a one there's a u plus v +down here but beta now there's a we're + + align:start position:0% +down here but beta now there's a we're + + + align:start position:0% +down here but beta now there's a we're +going to put beta here this is a a * V + + align:start position:0% +going to put beta here this is a a * V + + + align:start position:0% +going to put beta here this is a a * V +and then a k over + + align:start position:0% +and then a k over + + + align:start position:0% +and then a k over +U + + align:start position:0% +U + + + align:start position:0% +U +right so if we plot this as a function + + align:start position:0% +right so if we plot this as a function + + + align:start position:0% +right so if we plot this as a function +of v what does it look + + align:start position:0% + + + + align:start position:0% + +like monotonically increases this is a + + align:start position:0% +like monotonically increases this is a + + + align:start position:0% +like monotonically increases this is a +michis metan type form right + + align:start position:0% +michis metan type form right + + + align:start position:0% +michis metan type form right +where uh the r nod is a function of V + + align:start position:0% +where uh the r nod is a function of V + + + align:start position:0% +where uh the r nod is a function of V +starts out linear and then + + align:start position:0% +starts out linear and then + + + align:start position:0% +starts out linear and then +saturates right and we're trying + + align:start position:0% +saturates right and we're trying + + + align:start position:0% +saturates right and we're trying +to oops this is not V this is + + align:start position:0% +to oops this is not V this is + + + align:start position:0% +to oops this is not V this is +R okay right if we want to maximize R + + align:start position:0% +R okay right if we want to maximize R + + + align:start position:0% +R okay right if we want to maximize R +then V goes + + align:start position:0% +then V goes + + + align:start position:0% +then V goes +to Infinity + + align:start position:0% + + + + align:start position:0% + +right okay there was one other model + + align:start position:0% +right okay there was one other model + + + align:start position:0% +right okay there was one other model +that that Martin talked about which was + + align:start position:0% +that that Martin talked about which was + + + align:start position:0% +that that Martin talked about which was +the situation if the infectivity itself + + align:start position:0% +the situation if the infectivity itself + + + align:start position:0% +the situation if the infectivity itself +had a kind of M Menan type form right + + align:start position:0% +had a kind of M Menan type form right + + + align:start position:0% +had a kind of M Menan type form right +and this was again this was okay we + + align:start position:0% +and this was again this was okay we + + + align:start position:0% +and this was again this was okay we +still have an A there so it's some AV + + align:start position:0% +still have an A there so it's some AV + + + align:start position:0% +still have an A there so it's some AV +v c plus v right so this would be the + + align:start position:0% +v c plus v right so this would be the + + + align:start position:0% +v c plus v right so this would be the +situation where initially the + + align:start position:0% +situation where initially the + + + align:start position:0% +situation where initially the +infectivity increases with virence but + + align:start position:0% +infectivity increases with virence but + + + align:start position:0% +infectivity increases with virence but +um Beyond some uh some virence you no + + align:start position:0% +um Beyond some uh some virence you no + + + align:start position:0% +um Beyond some uh some virence you no +longer get an increased infectivity so + + align:start position:0% +longer get an increased infectivity so + + + align:start position:0% +longer get an increased infectivity so +for example if it's the case that every + + align:start position:0% +for example if it's the case that every + + + align:start position:0% +for example if it's the case that every +time you sneeze on somebody you're going + + align:start position:0% +time you sneeze on somebody you're going + + + align:start position:0% +time you sneeze on somebody you're going +to infect them then it doesn't matter if + + align:start position:0% +to infect them then it doesn't matter if + + + align:start position:0% +to infect them then it doesn't matter if +you double the number of viruses that + + align:start position:0% +you double the number of viruses that + + + align:start position:0% +you double the number of viruses that +you have you're still you still + + align:start position:0% +you have you're still you still + + + align:start position:0% +you have you're still you still +saturated the infe effectivity + + align:start position:0% +saturated the infe effectivity + + + align:start position:0% +saturated the infe effectivity +okay right + + align:start position:0% + + + + align:start position:0% + +now all right I I'll just tell you that + + align:start position:0% +now all right I I'll just tell you that + + + align:start position:0% +now all right I I'll just tell you that +in this case there ends up being uh some + + align:start position:0% +in this case there ends up being uh some + + + align:start position:0% +in this case there ends up being uh some +intermediate uh infectivity that you + + align:start position:0% +intermediate uh infectivity that you + + + align:start position:0% +intermediate uh infectivity that you +evolv to which comes here and indeed + + align:start position:0% +evolv to which comes here and indeed + + + align:start position:0% +evolv to which comes here and indeed +this kind of makes sense as + + align:start position:0% +this kind of makes sense as + + + align:start position:0% +this kind of makes sense as +as um C goes to + + align:start position:0% +as um C goes to + + + align:start position:0% +as um C goes to +Infinity then you end up wait what do I + + align:start position:0% +Infinity then you end up wait what do I + + + align:start position:0% +Infinity then you end up wait what do I +want right oh yeah so if C is very large + + align:start position:0% +want right oh yeah so if C is very large + + + align:start position:0% +want right oh yeah so if C is very large +then it just kind of looks like this all + + align:start position:0% +then it just kind of looks like this all + + + align:start position:0% +then it just kind of looks like this all +right it's divided by something large + + align:start position:0% +right it's divided by something large + + + align:start position:0% +right it's divided by something large +but in terms of the scaling with v it's + + align:start position:0% +but in terms of the scaling with v it's + + + align:start position:0% +but in terms of the scaling with v it's +just linear in V right and that means + + align:start position:0% +just linear in V right and that means + + + align:start position:0% +just linear in V right and that means +that the evolved virulence goes uh very + + align:start position:0% +that the evolved virulence goes uh very + + + align:start position:0% +that the evolved virulence goes uh very +large + + align:start position:0% +large + + + align:start position:0% +large +okay does that make + + align:start position:0% +okay does that make + + + align:start position:0% +okay does that make +sense no okay I'm so I guess all what I + + align:start position:0% +sense no okay I'm so I guess all what I + + + align:start position:0% +sense no okay I'm so I guess all what I +was saying is that if if C you know if + + align:start position:0% +was saying is that if if C you know if + + + align:start position:0% +was saying is that if if C you know if +you're in the region where C is somehow + + align:start position:0% +you're in the region where C is somehow + + + align:start position:0% +you're in the region where C is somehow +very large okay then um then you end up + + align:start position:0% +very large okay then um then you end up + + + align:start position:0% +very large okay then um then you end up +with the infectivity just being kind of + + align:start position:0% +with the infectivity just being kind of + + + align:start position:0% +with the infectivity just being kind of +proportional to the + + align:start position:0% +proportional to the + + + align:start position:0% +proportional to the +variance right because the the the + + align:start position:0% +variance right because the the the + + + align:start position:0% +variance right because the the the +virulence the V here in the denominator + + align:start position:0% +virulence the V here in the denominator + + + align:start position:0% +virulence the V here in the denominator +doesn't really contribute very much + + align:start position:0% +doesn't really contribute very much + + + align:start position:0% +doesn't really contribute very much +right and if you if you're in this that + + align:start position:0% +right and if you if you're in this that + + + align:start position:0% +right and if you if you're in this that +means that it's going to be the same + + align:start position:0% +means that it's going to be the same + + + align:start position:0% +means that it's going to be the same +kind of functional form as this except + + align:start position:0% +kind of functional form as this except + + + align:start position:0% +kind of functional form as this except +if it's a divided by C but it's still + + align:start position:0% +if it's a divided by C but it's still + + + align:start position:0% +if it's a divided by C but it's still +proportional to the variance and that + + align:start position:0% +proportional to the variance and that + + + align:start position:0% +proportional to the variance and that +that leads to a larger and larger + + align:start position:0% +that leads to a larger and larger + + + align:start position:0% +that leads to a larger and larger +evolved + + align:start position:0% +evolved + + + align:start position:0% +evolved +variance + + align:start position:0% +variance + + + align:start position:0% +variance +okay yep yes is it possible like + + align:start position:0% + + + + align:start position:0% + +than just yeah right right um so I think + + align:start position:0% +than just yeah right right um so I think + + + align:start position:0% +than just yeah right right um so I think +from real data I think people do uh + + align:start position:0% +from real data I think people do uh + + + align:start position:0% +from real data I think people do uh +people do argue about it but I think + + align:start position:0% +people do argue about it but I think + + + align:start position:0% +people do argue about it but I think +that it's + + align:start position:0% + + + + align:start position:0% + +um it seems to be you know I guess if + + align:start position:0% +um it seems to be you know I guess if + + + align:start position:0% +um it seems to be you know I guess if +you had to there is some sense that uh + + align:start position:0% +you had to there is some sense that uh + + + align:start position:0% +you had to there is some sense that uh +that it it does Plateau but it does but + + align:start position:0% +that it it does Plateau but it does but + + + align:start position:0% +that it it does Plateau but it does but +it's it is a function of it's an + + align:start position:0% +it's it is a function of it's an + + + align:start position:0% +it's it is a function of it's an +increasing fun of V but not sublinear + + align:start position:0% +increasing fun of V but not sublinear + + + align:start position:0% +increasing fun of V but not sublinear +right the question is how strong of a + + align:start position:0% +right the question is how strong of a + + + align:start position:0% +right the question is how strong of a +statement you can make there because + + align:start position:0% +statement you can make there because + + + align:start position:0% +statement you can make there because +also in many cases there is super + + align:start position:0% +also in many cases there is super + + + align:start position:0% +also in many cases there is super +infection and super infection tends to + + align:start position:0% +infection and super infection tends to + + + align:start position:0% +infection and super infection tends to +lead to even higher uh virulence than + + align:start position:0% +lead to even higher uh virulence than + + + align:start position:0% +lead to even higher uh virulence than +what you would expect from this um + + align:start position:0% +what you would expect from this um + + + align:start position:0% +what you would expect from this um +because you're competing against uh + + align:start position:0% +because you're competing against uh + + + align:start position:0% +because you're competing against uh +viruses in the same host right so you + + align:start position:0% +viruses in the same host right so you + + + align:start position:0% +viruses in the same host right so you +you kind of have to out comp out compete + + align:start position:0% +you kind of have to out comp out compete + + + align:start position:0% +you kind of have to out comp out compete +the other parasite in the host as well + + align:start position:0% +the other parasite in the host as well + + + align:start position:0% +the other parasite in the host as well +as kind of go on and you don't pay the + + align:start position:0% +as kind of go on and you don't pay the + + + align:start position:0% +as kind of go on and you don't pay the +full cost associated with keeping the + + align:start position:0% +full cost associated with keeping the + + + align:start position:0% +full cost associated with keeping the +host alive right so when you have super + + align:start position:0% +host alive right so when you have super + + + align:start position:0% +host alive right so when you have super +infection there's this notion that it it + + align:start position:0% +infection there's this notion that it it + + + align:start position:0% +infection there's this notion that it it +may the the better strategy from the + + align:start position:0% +may the the better strategy from the + + + align:start position:0% +may the the better strategy from the +standpoint of the parasite can be to + + align:start position:0% +standpoint of the parasite can be to + + + align:start position:0% +standpoint of the parasite can be to +just evolve very high virulence right so + + align:start position:0% +just evolve very high virulence right so + + + align:start position:0% +just evolve very high virulence right so +you're going to kill the host but you + + align:start position:0% +you're going to kill the host but you + + + align:start position:0% +you're going to kill the host but you +can get out quickly right so then then + + align:start position:0% +can get out quickly right so then then + + + align:start position:0% +can get out quickly right so then then +you can imagine that the the less + + align:start position:0% +you can imagine that the the less + + + align:start position:0% +you can imagine that the the less +virulent strain was kind of stranded in + + align:start position:0% +virulent strain was kind of stranded in + + + align:start position:0% +virulent strain was kind of stranded in +that host that died right uh so from + + align:start position:0% +that host that died right uh so from + + + align:start position:0% +that host that died right uh so from +that standpoint you can think about Evol + + align:start position:0% +that standpoint you can think about Evol + + + align:start position:0% +that standpoint you can think about Evol +you know in some cases for a parasite + + align:start position:0% +you know in some cases for a parasite + + + align:start position:0% +you know in some cases for a parasite +evolving low virulence is somehow like + + align:start position:0% +evolving low virulence is somehow like + + + align:start position:0% +evolving low virulence is somehow like +some Cooperative Behavior because uh + + align:start position:0% +some Cooperative Behavior because uh + + + align:start position:0% +some Cooperative Behavior because uh +you're you're keeping this host alive so + + align:start position:0% +you're you're keeping this host alive so + + + align:start position:0% +you're you're keeping this host alive so +that you can uh you're using the + + align:start position:0% +that you can uh you're using the + + + align:start position:0% +that you can uh you're using the +resources in a wise way so that you can + + align:start position:0% +resources in a wise way so that you can + + + align:start position:0% +resources in a wise way so that you can +uh you can infect other individuals but + + align:start position:0% +uh you can infect other individuals but + + + align:start position:0% +uh you can infect other individuals but +then uh that that kind of strategy is + + align:start position:0% +then uh that that kind of strategy is + + + align:start position:0% +then uh that that kind of strategy is +susceptible to these cheating strategies + + align:start position:0% +susceptible to these cheating strategies + + + align:start position:0% +susceptible to these cheating strategies +that just have high veilance and kill + + align:start position:0% +that just have high veilance and kill + + + align:start position:0% +that just have high veilance and kill +the host and then get get onto a new + + align:start position:0% +the host and then get get onto a new + + + align:start position:0% +the host and then get get onto a new +host right yeah so I think there are + + align:start position:0% +host right yeah so I think there are + + + align:start position:0% +host right yeah so I think there are +enough of these sorts of issues that + + align:start position:0% +enough of these sorts of issues that + + + align:start position:0% +enough of these sorts of issues that +it's hard to take any of this too + + align:start position:0% +it's hard to take any of this too + + + align:start position:0% +it's hard to take any of this too +seriously I would say that perhaps where + + align:start position:0% +seriously I would say that perhaps where + + + align:start position:0% +seriously I would say that perhaps where +this field has had the the biggest + + align:start position:0% +this field has had the the biggest + + + align:start position:0% +this field has had the the biggest +impact is in the context of of + + align:start position:0% +impact is in the context of of + + + align:start position:0% +impact is in the context of of +vaccinations all right + + align:start position:0% + + + + align:start position:0% + +because uh you can really measure our + + align:start position:0% +because uh you can really measure our + + + align:start position:0% +because uh you can really measure our +knot for many different uh many + + align:start position:0% +knot for many different uh many + + + align:start position:0% +knot for many different uh many +different diseases and I think that + + align:start position:0% +different diseases and I think that + + + align:start position:0% +different diseases and I think that +that's somehow easier to measure than + + align:start position:0% +that's somehow easier to measure than + + + align:start position:0% +that's somehow easier to measure than +many other things because you can uh try + + align:start position:0% +many other things because you can uh try + + + align:start position:0% +many other things because you can uh try +to do uh tracing of um of infections + + align:start position:0% +to do uh tracing of um of infections + + + align:start position:0% +to do uh tracing of um of infections +right so if you think about somebody + + align:start position:0% +right so if you think about somebody + + + align:start position:0% +right so if you think about somebody +that gets infected and moves to a new + + align:start position:0% +that gets infected and moves to a new + + + align:start position:0% +that gets infected and moves to a new +city or you know lands in a new city you + + align:start position:0% +city or you know lands in a new city you + + + align:start position:0% +city or you know lands in a new city you +can try to figure out who they who they + + align:start position:0% +can try to figure out who they who they + + + align:start position:0% +can try to figure out who they who they +infected right so then you can go and + + align:start position:0% +infected right so then you can go and + + + align:start position:0% +infected right so then you can go and +measure these R not parameters right and + + align:start position:0% +measure these R not parameters right and + + + align:start position:0% +measure these R not parameters right and +uh and of course the diseases that we we + + align:start position:0% +uh and of course the diseases that we we + + + align:start position:0% +uh and of course the diseases that we we +worry about tend to have AR knots larger + + align:start position:0% +worry about tend to have AR knots larger + + + align:start position:0% +worry about tend to have AR knots larger +than one right um and how large they are + + align:start position:0% +than one right um and how large they are + + + align:start position:0% +than one right um and how large they are +tells you about how difficult um kind of + + align:start position:0% +tells you about how difficult um kind of + + + align:start position:0% +tells you about how difficult um kind of +vaccination will be in order to um in + + align:start position:0% +vaccination will be in order to um in + + + align:start position:0% +vaccination will be in order to um in +order to be successful and and to remove + + align:start position:0% +order to be successful and and to remove + + + align:start position:0% +order to be successful and and to remove +um the disease from the population right + + align:start position:0% +um the disease from the population right + + + align:start position:0% +um the disease from the population right +so uh if you're if you're curious after + + align:start position:0% +so uh if you're if you're curious after + + + align:start position:0% +so uh if you're if you're curious after +class you can come up and there's a nice + + align:start position:0% +class you can come up and there's a nice + + + align:start position:0% +class you can come up and there's a nice +table uh that I have here for small poox + + align:start position:0% +table uh that I have here for small poox + + + align:start position:0% +table uh that I have here for small poox +measles whipping cough German Measles + + align:start position:0% +measles whipping cough German Measles + + + align:start position:0% +measles whipping cough German Measles +chickenpox diptheria scarlet fever mumps + + align:start position:0% +chickenpox diptheria scarlet fever mumps + + + align:start position:0% +chickenpox diptheria scarlet fever mumps +and poliomyelitis + + align:start position:0% +and poliomyelitis + + + align:start position:0% +and poliomyelitis +uh estimates of uh of R knots right and + + align:start position:0% +uh estimates of uh of R knots right and + + + align:start position:0% +uh estimates of uh of R knots right and +they they kind of range U they're kind + + align:start position:0% +they they kind of range U they're kind + + + align:start position:0% +they they kind of range U they're kind +of five to five to 15 to give you a + + align:start position:0% +of five to five to 15 to give you a + + + align:start position:0% +of five to five to 15 to give you a +sense right uh and so which diseases U + + align:start position:0% +sense right uh and so which diseases U + + + align:start position:0% +sense right uh and so which diseases U +right so if you want to remove the + + align:start position:0% +right so if you want to remove the + + + align:start position:0% +right so if you want to remove the +disease from the population what is it + + align:start position:0% +disease from the population what is it + + + align:start position:0% +disease from the population what is it +that changes in terms of + + align:start position:0% +that changes in terms of + + + align:start position:0% +that changes in terms of +vaccination uh in order to REM remove + + align:start position:0% +vaccination uh in order to REM remove + + + align:start position:0% +vaccination uh in order to REM remove +the + + align:start position:0% + + + + align:start position:0% + +disease yes are + + align:start position:0% + + + + align:start position:0% + +not that's right so you you um by + + align:start position:0% +not that's right so you you um by + + + align:start position:0% +not that's right so you you um by +vaccinating you're kind of removing + + align:start position:0% +vaccinating you're kind of removing + + + align:start position:0% +vaccinating you're kind of removing +susceptible individuals from the + + align:start position:0% +susceptible individuals from the + + + align:start position:0% +susceptible individuals from the +population and making them resistant + + align:start position:0% +population and making them resistant + + + align:start position:0% +population and making them resistant +somehow right and uh and the r not + + align:start position:0% +somehow right and uh and the r not + + + align:start position:0% +somehow right and uh and the r not +parameter tells you about what fraction + + align:start position:0% +parameter tells you about what fraction + + + align:start position:0% +parameter tells you about what fraction +of the population you have to vaccinate + + align:start position:0% +of the population you have to vaccinate + + + align:start position:0% +of the population you have to vaccinate +in order to remove the uh the parasite + + align:start position:0% +in order to remove the uh the parasite + + + align:start position:0% +in order to remove the uh the parasite +from the population right so there're + + align:start position:0% +from the population right so there're + + + align:start position:0% +from the population right so there're +basically you have to vaccinate a + + align:start position:0% +basically you have to vaccinate a + + + align:start position:0% +basically you have to vaccinate a +fraction of percentage or + + align:start position:0% +fraction of percentage or + + + align:start position:0% +fraction of percentage or +P that's greater than 1 minus one/ r KN + + align:start position:0% +P that's greater than 1 minus one/ r KN + + + align:start position:0% +P that's greater than 1 minus one/ r KN +okay so as R KN kind of gets very large + + align:start position:0% +okay so as R KN kind of gets very large + + + align:start position:0% +okay so as R KN kind of gets very large +it means that you have to vaccinate + + align:start position:0% +it means that you have to vaccinate + + + align:start position:0% +it means that you have to vaccinate +essentially + + align:start position:0% +essentially + + + align:start position:0% +essentially +everybody okay so if if you have R knot + + align:start position:0% +everybody okay so if if you have R knot + + + align:start position:0% +everybody okay so if if you have R knot +of say five which is typical of many of + + align:start position:0% +of say five which is typical of many of + + + align:start position:0% +of say five which is typical of many of +these diseases it's saying you kind of + + align:start position:0% +these diseases it's saying you kind of + + + align:start position:0% +these diseases it's saying you kind of +have to vaccinate uh kind of 80% of the + + align:start position:0% +have to vaccinate uh kind of 80% of the + + + align:start position:0% +have to vaccinate uh kind of 80% of the +population right you can never get to + + align:start position:0% +population right you can never get to + + + align:start position:0% +population right you can never get to +100% right and that that's why it's very + + align:start position:0% +100% right and that that's why it's very + + + align:start position:0% +100% right and that that's why it's very +difficult to get rid of these get rid of + + align:start position:0% +difficult to get rid of these get rid of + + + align:start position:0% +difficult to get rid of these get rid of +these diseases with large R + + align:start position:0% +these diseases with large R + + + align:start position:0% +these diseases with large R +knots and incidentally they note that + + align:start position:0% +knots and incidentally they note that + + + align:start position:0% +knots and incidentally they note that +small pox + + align:start position:0% +small pox + + + align:start position:0% +small pox +has an R knot of kind of three to + + align:start position:0% +has an R knot of kind of three to + + + align:start position:0% +has an R knot of kind of three to +five in and this is of this always + + align:start position:0% +five in and this is of this always + + + align:start position:0% +five in and this is of this always +depends on the environment but in the + + align:start position:0% +depends on the environment but in the + + + align:start position:0% +depends on the environment but in the +case where they measured uh small pox + + align:start position:0% +case where they measured uh small pox + + + align:start position:0% +case where they measured uh small pox +are not it's kind of three to five and + + align:start position:0% +are not it's kind of three to five and + + + align:start position:0% +are not it's kind of three to five and +and this is sort of small as compared to + + align:start position:0% +and this is sort of small as compared to + + + align:start position:0% +and this is sort of small as compared to +many of these diseases and this is + + align:start position:0% +many of these diseases and this is + + + align:start position:0% +many of these diseases and this is +telling us that that small pox is + + align:start position:0% +telling us that that small pox is + + + align:start position:0% +telling us that that small pox is +easier to get rid of via vaccinations + + align:start position:0% +easier to get rid of via vaccinations + + + align:start position:0% +easier to get rid of via vaccinations +than many of these other diseases and + + align:start position:0% +than many of these other diseases and + + + align:start position:0% +than many of these other diseases and +indeed we've um you know the the + + align:start position:0% +indeed we've um you know the the + + + align:start position:0% +indeed we've um you know the the +vaccination uh procedures have been more + + align:start position:0% +vaccination uh procedures have been more + + + align:start position:0% +vaccination uh procedures have been more +successful in small pox than it than the + + align:start position:0% +successful in small pox than it than the + + + align:start position:0% +successful in small pox than it than the +others right you + + align:start position:0% +others right you + + + align:start position:0% +others right you +know I I don't um but if you know maybe + + align:start position:0% +know I I don't um but if you know maybe + + + align:start position:0% +know I I don't um but if you know maybe +maybe in the next 20 minutes somebody + + align:start position:0% +maybe in the next 20 minutes somebody + + + align:start position:0% +maybe in the next 20 minutes somebody +can Google uh this and U at least I we + + align:start position:0% +can Google uh this and U at least I we + + + align:start position:0% +can Google uh this and U at least I we +can we can estimate this right right now + + align:start position:0% +can we can estimate this right right now + + + align:start position:0% +can we can estimate this right right now +though you know I mean we had we've had + + align:start position:0% +though you know I mean we had we've had + + + align:start position:0% +though you know I mean we had we've had +what you know five Ebola patients come + + align:start position:0% +what you know five Ebola patients come + + + align:start position:0% +what you know five Ebola patients come +to the United States and we've gotten + + align:start position:0% +to the United States and we've gotten + + + align:start position:0% +to the United States and we've gotten +two or three infections so I I'll say + + align:start position:0% +two or three infections so I I'll say + + + align:start position:0% +two or three infections so I I'll say +three + + align:start position:0% +three + + + align:start position:0% +three +fifths this it obviously depends on the + + align:start position:0% +fifths this it obviously depends on the + + + align:start position:0% +fifths this it obviously depends on the +environment right yeah + + align:start position:0% + + + + align:start position:0% + +guess in York City measure you how many + + align:start position:0% +guess in York City measure you how many + + + align:start position:0% +guess in York City measure you how many +that's + + align:start position:0% +that's + + + align:start position:0% +that's +right yeah no but but AR no the thing is + + align:start position:0% +right yeah no but but AR no the thing is + + + align:start position:0% +right yeah no but but AR no the thing is +you don't have to do you don't have to + + align:start position:0% +you don't have to do you don't have to + + + align:start position:0% +you don't have to do you don't have to +do anything that's so immoral because + + align:start position:0% +do anything that's so immoral because + + + align:start position:0% +do anything that's so immoral because +what you're interested in is the are not + + align:start position:0% +what you're interested in is the are not + + + align:start position:0% +what you're interested in is the are not +for an individual in an actual + + align:start position:0% +for an individual in an actual + + + align:start position:0% +for an individual in an actual +environment that they're actually going + + align:start position:0% +environment that they're actually going + + + align:start position:0% +environment that they're actually going +to be in right so this is a situation + + align:start position:0% +to be in right so this is a situation + + + align:start position:0% +to be in right so this is a situation +where you know the doctor comes back + + align:start position:0% +where you know the doctor comes back + + + align:start position:0% +where you know the doctor comes back +from Africa after working with Doctors + + align:start position:0% +from Africa after working with Doctors + + + align:start position:0% +from Africa after working with Doctors +Without Borders right he knows you know + + align:start position:0% +Without Borders right he knows you know + + + align:start position:0% +Without Borders right he knows you know +in this day you know he knows that he + + align:start position:0% +in this day you know he knows that he + + + align:start position:0% +in this day you know he knows that he +has to watch out for a fever and and + + align:start position:0% +has to watch out for a fever and and + + + align:start position:0% +has to watch out for a fever and and +then if he gets a fever he calls in and + + align:start position:0% +then if he gets a fever he calls in and + + + align:start position:0% +then if he gets a fever he calls in and +he's brought to the hospital right and + + align:start position:0% +he's brought to the hospital right and + + + align:start position:0% +he's brought to the hospital right and +that's the world that we're interested + + align:start position:0% +that's the world that we're interested + + + align:start position:0% +that's the world that we're interested +in of what the AR not is right it's not + + align:start position:0% +in of what the AR not is right it's not + + + align:start position:0% +in of what the AR not is right it's not +the world in which you know there's Fe + + align:start position:0% +the world in which you know there's Fe + + + align:start position:0% +the world in which you know there's Fe +fevers everywhere and nobody know you + + align:start position:0% +fevers everywhere and nobody know you + + + align:start position:0% +fevers everywhere and nobody know you +know and you know right so it's um so + + align:start position:0% +know and you know right so it's um so + + + align:start position:0% +know and you know right so it's um so +the the r not for in the United States + + align:start position:0% +the the r not for in the United States + + + align:start position:0% +the the r not for in the United States +is going to be much lower than the r not + + align:start position:0% +is going to be much lower than the r not + + + align:start position:0% +is going to be much lower than the r not +in you know somewhere else right yeah is + + align:start position:0% +in you know somewhere else right yeah is + + + align:start position:0% +in you know somewhere else right yeah is +there a of disase that you don't Transit + + align:start position:0% +there a of disase that you don't Transit + + + align:start position:0% +there a of disase that you don't Transit +between people you get + + align:start position:0% +between people you get + + + align:start position:0% +between people you get +yeah right so I I think + + align:start position:0% +yeah right so I I think + + + align:start position:0% +yeah right so I I think +that you could try to generate a similar + + align:start position:0% +that you could try to generate a similar + + + align:start position:0% +that you could try to generate a similar +kind of R not for those disease all it's + + align:start position:0% +kind of R not for those disease all it's + + + align:start position:0% +kind of R not for those disease all it's +going to be very muddled right in the + + align:start position:0% +going to be very muddled right in the + + + align:start position:0% +going to be very muddled right in the +case of where you have all the vectors + + align:start position:0% +case of where you have all the vectors + + + align:start position:0% +case of where you have all the vectors +and so forth because it's not even + + align:start position:0% + + + + align:start position:0% + +clear yeah I yeah I'm hesitant I'm + + align:start position:0% +clear yeah I yeah I'm hesitant I'm + + + align:start position:0% +clear yeah I yeah I'm hesitant I'm +hesitant to to say too much because I + + align:start position:0% +hesitant to to say too much because I + + + align:start position:0% +hesitant to to say too much because I +don't know + + align:start position:0% +don't know + + + align:start position:0% +don't know +anything it's 1.5 2.5 for Ebola here or + + align:start position:0% +anything it's 1.5 2.5 for Ebola here or + + + align:start position:0% +anything it's 1.5 2.5 for Ebola here or +in um + + align:start position:0% +in um + + + align:start position:0% +in um +it says the 2014 West + + align:start position:0% +it says the 2014 West + + + align:start position:0% +it says the 2014 West +Africa ah okay so this is this is in + + align:start position:0% +Africa ah okay so this is this is in + + + align:start position:0% +Africa ah okay so this is this is in +West Africa then okay right yeah and and + + align:start position:0% +West Africa then okay right yeah and and + + + align:start position:0% +West Africa then okay right yeah and and +the idea is that it has obviously spread + + align:start position:0% +the idea is that it has obviously spread + + + align:start position:0% +the idea is that it has obviously spread +exponentially which means it has it had + + align:start position:0% +exponentially which means it has it had + + + align:start position:0% +exponentially which means it has it had +to have been larger than one right but + + align:start position:0% +to have been larger than one right but + + + align:start position:0% +to have been larger than one right but +and I think it's important to remember + + align:start position:0% +and I think it's important to remember + + + align:start position:0% +and I think it's important to remember +that you know just because you have a + + align:start position:0% +that you know just because you have a + + + align:start position:0% +that you know just because you have a +chart with a bunch of rots this is not + + align:start position:0% +chart with a bunch of rots this is not + + + align:start position:0% +chart with a bunch of rots this is not +set in stone right public policy hygiene + + align:start position:0% +set in stone right public policy hygiene + + + align:start position:0% +set in stone right public policy hygiene +and everything changes this right and + + align:start position:0% +and everything changes this right and + + + align:start position:0% +and everything changes this right and +we'd like to drive it down yeah was + + align:start position:0% +we'd like to drive it down yeah was + + + align:start position:0% +we'd like to drive it down yeah was +there a question in the back I was just + + align:start position:0% +there a question in the back I was just + + + align:start position:0% +there a question in the back I was just +going to say + + align:start position:0% +going to say + + + align:start position:0% +going to say +same thing about two okay all right um + + align:start position:0% +same thing about two okay all right um + + + align:start position:0% +same thing about two okay all right um +right so that means that uh that we can + + align:start position:0% +right so that means that uh that we can + + + align:start position:0% +right so that means that uh that we can +actually in principle vaccinate against + + align:start position:0% +actually in principle vaccinate against + + + align:start position:0% +actually in principle vaccinate against +Ebola we only have to get you know over + + align:start position:0% +Ebola we only have to get you know over + + + align:start position:0% +Ebola we only have to get you know over +50% of the population vaccinated in West + + align:start position:0% +50% of the population vaccinated in West + + + align:start position:0% +50% of the population vaccinated in West +Africa and then we can maybe uh make it + + align:start position:0% +Africa and then we can maybe uh make it + + + align:start position:0% +Africa and then we can maybe uh make it +so it cannot spread and become an + + align:start position:0% +so it cannot spread and become an + + + align:start position:0% +so it cannot spread and become an +epidemic right of course we need to have + + align:start position:0% +epidemic right of course we need to have + + + align:start position:0% +epidemic right of course we need to have +a vaccine first + + align:start position:0% + + + + align:start position:0% + +right all right so I I think that I'm + + align:start position:0% +right all right so I I think that I'm + + + align:start position:0% +right all right so I I think that I'm +going to skip the discussion of Sir + + align:start position:0% +going to skip the discussion of Sir + + + align:start position:0% +going to skip the discussion of Sir +models because you are going to uh play + + align:start position:0% +models because you are going to uh play + + + align:start position:0% +models because you are going to uh play +with some of them in the context of your + + align:start position:0% +with some of them in the context of your + + + align:start position:0% +with some of them in the context of your +problem set um and if you just Google + + align:start position:0% +problem set um and if you just Google + + + align:start position:0% +problem set um and if you just Google +sir you can find it very similar uh kind + + align:start position:0% +sir you can find it very similar uh kind + + + align:start position:0% +sir you can find it very similar uh kind +of intuition that you get from this + + align:start position:0% +of intuition that you get from this + + + align:start position:0% +of intuition that you get from this +model + + align:start position:0% +model + + + align:start position:0% +model +okay um I do uh because I do want to + + align:start position:0% +okay um I do uh because I do want to + + + align:start position:0% +okay um I do uh because I do want to +spend the last 15 minutes at least uh + + align:start position:0% +spend the last 15 minutes at least uh + + + align:start position:0% +spend the last 15 minutes at least uh +talking about the evolution of sex + + align:start position:0% +talking about the evolution of sex + + + align:start position:0% +talking about the evolution of sex +because it is an interesting topic and + + align:start position:0% +because it is an interesting topic and + + + align:start position:0% +because it is an interesting topic and +and and I think the paper is kind of a + + align:start position:0% +and and I think the paper is kind of a + + + align:start position:0% +and and I think the paper is kind of a +nice disc uh discussion of + + align:start position:0% + + + + align:start position:0% + +it all + + align:start position:0% + + + + align:start position:0% + +right all right so can somebody say why + + align:start position:0% +right all right so can somebody say why + + + align:start position:0% +right all right so can somebody say why +is + + align:start position:0% +is + + + align:start position:0% +is +that this is a you know kind of a puzzle + + align:start position:0% +that this is a you know kind of a puzzle + + + align:start position:0% +that this is a you know kind of a puzzle +at + + align:start position:0% + + + + align:start position:0% + +all + + align:start position:0% + + + + align:start position:0% + +yeah almost all situations + + align:start position:0% + + + + align:start position:0% + +imag that's right um all right so + + align:start position:0% +imag that's right um all right so + + + align:start position:0% +imag that's right um all right so +so right so sex is costly and in + + align:start position:0% +so right so sex is costly and in + + + align:start position:0% +so right so sex is costly and in +particular if you have this obligate + + align:start position:0% +particular if you have this obligate + + + align:start position:0% +particular if you have this obligate +biparental sex right then there's in + + align:start position:0% +biparental sex right then there's in + + + align:start position:0% +biparental sex right then there's in +particular there's the so-called uh + + align:start position:0% +particular there's the so-called uh + + + align:start position:0% +particular there's the so-called uh +two-fold cost uh two-fold cost of + + align:start position:0% + + + + align:start position:0% + +males because you can imagine comparing + + align:start position:0% +males because you can imagine comparing + + + align:start position:0% +males because you can imagine comparing +uh kind of these two populations right + + align:start position:0% +uh kind of these two populations right + + + align:start position:0% +uh kind of these two populations right +one of which has both males and females + + align:start position:0% +one of which has both males and females + + + align:start position:0% +one of which has both males and females +and one of them is just maybe either + + align:start position:0% +and one of them is just maybe either + + + align:start position:0% +and one of them is just maybe either +reproducing uh asexually or + + align:start position:0% +reproducing uh asexually or + + + align:start position:0% +reproducing uh asexually or +parthenogenic or hermitically or whatnot + + align:start position:0% +parthenogenic or hermitically or whatnot + + + align:start position:0% +parthenogenic or hermitically or whatnot +yeah okay um and you know so you know + + align:start position:0% +yeah okay um and you know so you know + + + align:start position:0% +yeah okay um and you know so you know +you just imagine well if you have a male + + align:start position:0% +you just imagine well if you have a male + + + align:start position:0% +you just imagine well if you have a male +and a female then on average if they + + align:start position:0% +and a female then on average if they + + + align:start position:0% +and a female then on average if they +have two kids you end up with another + + align:start position:0% +have two kids you end up with another + + + align:start position:0% +have two kids you end up with another +male and a female right and you know of + + align:start position:0% +male and a female right and you know of + + + align:start position:0% +male and a female right and you know of +course this can be many different males + + align:start position:0% +course this can be many different males + + + align:start position:0% +course this can be many different males +and females so you don't have to have + + align:start position:0% +and females so you don't have to have + + + align:start position:0% +and females so you don't have to have +any sibling anything right okay but if + + align:start position:0% +any sibling anything right okay but if + + + align:start position:0% +any sibling anything right okay but if +everybody is having two gener if if + + align:start position:0% +everybody is having two gener if if + + + align:start position:0% +everybody is having two gener if if +every + + align:start position:0% +every + + + align:start position:0% +every +generation each uh each female is giving + + align:start position:0% +generation each uh each female is giving + + + align:start position:0% +generation each uh each female is giving +birth to two um two progyny then you end + + align:start position:0% +birth to two um two progyny then you end + + + align:start position:0% +birth to two um two progyny then you end +up with a constant population size right + + align:start position:0% +up with a constant population size right + + + align:start position:0% +up with a constant population size right +whereas if you started out in a + + align:start position:0% +whereas if you started out in a + + + align:start position:0% +whereas if you started out in a +population with just two females and + + align:start position:0% +population with just two females and + + + align:start position:0% +population with just two females and +they were reproducing uh hermitically + + align:start position:0% +they were reproducing uh hermitically + + + align:start position:0% +they were reproducing uh hermitically +then you end up + + align:start position:0% +then you end up + + + align:start position:0% +then you end up +with you know whatever more okay eight + + align:start position:0% +with you know whatever more okay eight + + + align:start position:0% +with you know whatever more okay eight +okay so you can see that you get a + + align:start position:0% +okay so you can see that you get a + + + align:start position:0% +okay so you can see that you get a +factor of two in the rate of exponential + + align:start position:0% +factor of two in the rate of exponential + + + align:start position:0% +factor of two in the rate of exponential +growth of the population yeah I mean it + + align:start position:0% +growth of the population yeah I mean it + + + align:start position:0% +growth of the population yeah I mean it +seems to the + + align:start position:0% +seems to the + + + align:start position:0% +seems to the +question why + + align:start position:0% +question why + + + align:start position:0% +question why +Mal yeah yes yeah okay right so I think + + align:start position:0% +Mal yeah yes yeah okay right so I think + + + align:start position:0% +Mal yeah yes yeah okay right so I think +that uh right so this is the most + + align:start position:0% +that uh right so this is the most + + + align:start position:0% +that uh right so this is the most +extreme cost of sex right but then also + + align:start position:0% +extreme cost of sex right but then also + + + align:start position:0% +extreme cost of sex right but then also +you can you can think about even just + + align:start position:0% +you can you can think about even just + + + align:start position:0% +you can you can think about even just +hor Al Gene transfer among bacteria that + + align:start position:0% +hor Al Gene transfer among bacteria that + + + align:start position:0% +hor Al Gene transfer among bacteria that +it's a costly behavior in some way or + + align:start position:0% +it's a costly behavior in some way or + + + align:start position:0% +it's a costly behavior in some way or +another it's not as costly as this right + + align:start position:0% +another it's not as costly as this right + + + align:start position:0% +another it's not as costly as this right +but if you're going to think about U + + align:start position:0% +but if you're going to think about U + + + align:start position:0% +but if you're going to think about U +bacteria that uh that in their competent + + align:start position:0% +bacteria that uh that in their competent + + + align:start position:0% +bacteria that uh that in their competent +State when bodus kind of pulls in DNA + + align:start position:0% +State when bodus kind of pulls in DNA + + + align:start position:0% +State when bodus kind of pulls in DNA +you know it stops dividing and then it + + align:start position:0% +you know it stops dividing and then it + + + align:start position:0% +you know it stops dividing and then it +enters a state where it kind of reels + + align:start position:0% +enters a state where it kind of reels + + + align:start position:0% +enters a state where it kind of reels +things in and it can pick up um you know + + align:start position:0% +things in and it can pick up um you know + + + align:start position:0% +things in and it can pick up um you know +DNA that may be harmful in some cases + + align:start position:0% +DNA that may be harmful in some cases + + + align:start position:0% +DNA that may be harmful in some cases +right so there there are various costs + + align:start position:0% +right so there there are various costs + + + align:start position:0% +right so there there are various costs +that are uh for um for the you know if + + align:start position:0% +that are uh for um for the you know if + + + align:start position:0% +that are uh for um for the you know if +you want to call horizontal Gene + + align:start position:0% +you want to call horizontal Gene + + + align:start position:0% +you want to call horizontal Gene +transfer sex right but in in um um right + + align:start position:0% +transfer sex right but in in um um right + + + align:start position:0% +transfer sex right but in in um um right +so the key thing of sexual reproduction + + align:start position:0% +so the key thing of sexual reproduction + + + align:start position:0% +so the key thing of sexual reproduction +is it's it's somehow is um is the + + align:start position:0% +is it's it's somehow is um is the + + + align:start position:0% +is it's it's somehow is um is the +sharing of the of the DNA and I'd say + + align:start position:0% +sharing of the of the DNA and I'd say + + + align:start position:0% +sharing of the of the DNA and I'd say +that this can either be uh relatively + + align:start position:0% +that this can either be uh relatively + + + align:start position:0% +that this can either be uh relatively +low cost or relatively high cost but + + align:start position:0% +low cost or relatively high cost but + + + align:start position:0% +low cost or relatively high cost but +this is the most extreme version of it + + align:start position:0% +this is the most extreme version of it + + + align:start position:0% +this is the most extreme version of it +and I'd say um as you know as a species + + align:start position:0% +and I'd say um as you know as a species + + + align:start position:0% +and I'd say um as you know as a species +that reproduces sexually obl with + + align:start position:0% +that reproduces sexually obl with + + + align:start position:0% +that reproduces sexually obl with +obligate biparental sex then I'd say + + align:start position:0% +obligate biparental sex then I'd say + + + align:start position:0% +obligate biparental sex then I'd say +that and you know not only humans but Mo + + align:start position:0% +that and you know not only humans but Mo + + + align:start position:0% +that and you know not only humans but Mo +almost all uh you know animals uh have + + align:start position:0% +almost all uh you know animals uh have + + + align:start position:0% +almost all uh you know animals uh have +uh this form of reproduction it's it's I + + align:start position:0% +uh this form of reproduction it's it's I + + + align:start position:0% +uh this form of reproduction it's it's I +would say it's sort of surprising given + + align:start position:0% +would say it's sort of surprising given + + + align:start position:0% +would say it's sort of surprising given +that this is a huge + + align:start position:0% +that this is a huge + + + align:start position:0% +that this is a huge +cost right yeah so it's but it's not + + align:start position:0% +cost right yeah so it's but it's not + + + align:start position:0% +cost right yeah so it's but it's not +that all species that engage in any sort + + align:start position:0% +that all species that engage in any sort + + + align:start position:0% +that all species that engage in any sort +of uh Gene transfer H bear this large + + align:start position:0% +of uh Gene transfer H bear this large + + + align:start position:0% +of uh Gene transfer H bear this large +cost but they they bear more modest + + align:start position:0% +cost but they they bear more modest + + + align:start position:0% +cost but they they bear more modest +costs although yeah of course + + align:start position:0% + + + + align:start position:0% + +likees this by just like having multiple + + align:start position:0% +likees this by just like having multiple + + + align:start position:0% +likees this by just like having multiple +children per + + align:start position:0% +children per + + + align:start position:0% +children per +sex you're you're just saying that they + + align:start position:0% +sex you're you're just saying that they + + + align:start position:0% +sex you're you're just saying that they +can just have more kids um yeah yeah + + align:start position:0% +can just have more kids um yeah yeah + + + align:start position:0% +can just have more kids um yeah yeah +although I mean the basic statement is + + align:start position:0% +although I mean the basic statement is + + + align:start position:0% +although I mean the basic statement is +still true though let's say that the + + align:start position:0% +still true though let's say that the + + + align:start position:0% +still true though let's say that the +these females all have three three kids + + align:start position:0% +these females all have three three kids + + + align:start position:0% +these females all have three three kids +they get to grow exponentially but then + + align:start position:0% +they get to grow exponentially but then + + + align:start position:0% +they get to grow exponentially but then +these guys grow faster and ultimately + + align:start position:0% +these guys grow faster and ultimately + + + align:start position:0% +these guys grow faster and ultimately +there there's going to be competition + + align:start position:0% +there there's going to be competition + + + align:start position:0% +there there's going to be competition +for resources and these ones will still + + align:start position:0% +for resources and these ones will still + + + align:start position:0% +for resources and these ones will still +win yeah right so the question is if you + + align:start position:0% +win yeah right so the question is if you + + + align:start position:0% +win yeah right so the question is if you +you can imagine you have a population + + align:start position:0% +you can imagine you have a population + + + align:start position:0% +you can imagine you have a population +that's reproducing sexually if there one + + align:start position:0% +that's reproducing sexually if there one + + + align:start position:0% +that's reproducing sexually if there one +female has a mutation that leads her to + + align:start position:0% +female has a mutation that leads her to + + + align:start position:0% +female has a mutation that leads her to +start reproducing parthenogenic that + + align:start position:0% +start reproducing parthenogenic that + + + align:start position:0% +start reproducing parthenogenic that +mutation you'd expect should spread + + align:start position:0% +mutation you'd expect should spread + + + align:start position:0% +mutation you'd expect should spread +throughout the population very rapidly + + align:start position:0% +throughout the population very rapidly + + + align:start position:0% +throughout the population very rapidly +right and indeed there there there are + + align:start position:0% +right and indeed there there there are + + + align:start position:0% +right and indeed there there there are +these cases of for example sharks held + + align:start position:0% +these cases of for example sharks held + + + align:start position:0% +these cases of for example sharks held +in captivity where a female held in + + align:start position:0% +in captivity where a female held in + + + align:start position:0% +in captivity where a female held in +captivity for for years EV gives birth + + align:start position:0% +captivity for for years EV gives birth + + + align:start position:0% +captivity for for years EV gives birth +to to you know to daughters right so + + align:start position:0% +to to you know to daughters right so + + + align:start position:0% +to to you know to daughters right so +this this and um as far as you know it's + + align:start position:0% +this this and um as far as you know it's + + + align:start position:0% +this this and um as far as you know it's +so so this sort of Virgin birth is is + + align:start position:0% +so so this sort of Virgin birth is is + + + align:start position:0% +so so this sort of Virgin birth is is +possible I'm not aware okay well I'm not + + align:start position:0% +possible I'm not aware okay well I'm not + + + align:start position:0% +possible I'm not aware okay well I'm not +going to talk okay okay but um but yeah + + align:start position:0% +going to talk okay okay but um but yeah + + + align:start position:0% +going to talk okay okay but um but yeah +so but it in some animals it is at least + + align:start position:0% +so but it in some animals it is at least + + + align:start position:0% +so but it in some animals it is at least +possible I'll say okay all right okay so + + align:start position:0% +possible I'll say okay all right okay so + + + align:start position:0% +possible I'll say okay all right okay so +then you you have to ask well okay well + + align:start position:0% +then you you have to ask well okay well + + + align:start position:0% +then you you have to ask well okay well +what's um what kind of selected + + align:start position:0% +what's um what kind of selected + + + align:start position:0% +what's um what kind of selected +Advantage could sexual reproduction have + + align:start position:0% +Advantage could sexual reproduction have + + + align:start position:0% +Advantage could sexual reproduction have +that could possibly compensate for this + + align:start position:0% +that could possibly compensate for this + + + align:start position:0% +that could possibly compensate for this +so-called twofold cost of sex or + + align:start position:0% +so-called twofold cost of sex or + + + align:start position:0% +so-called twofold cost of sex or +two-fold cost of + + align:start position:0% +two-fold cost of + + + align:start position:0% +two-fold cost of +males + + align:start position:0% +males + + + align:start position:0% +males +okay and what what is the + + align:start position:0% +okay and what what is the + + + align:start position:0% +okay and what what is the +uh what is the argument that's made in + + align:start position:0% +uh what is the argument that's made in + + + align:start position:0% +uh what is the argument that's made in +this uh this + + align:start position:0% +this uh this + + + align:start position:0% +this uh this +[Applause] + + align:start position:0% + + + + align:start position:0% + +paper anybody + + align:start position:0% + + + + align:start position:0% + +yes that's right right so this this + + align:start position:0% +yes that's right right so this this + + + align:start position:0% +yes that's right right so this this +recombination is favoring uh genetic + + align:start position:0% +recombination is favoring uh genetic + + + align:start position:0% +recombination is favoring uh genetic +diversity right so there are a number of + + align:start position:0% +diversity right so there are a number of + + + align:start position:0% +diversity right so there are a number of +different mechanisms um I say that the + + align:start position:0% +different mechanisms um I say that the + + + align:start position:0% +different mechanisms um I say that the +at the heart of it okay so this idea of + + align:start position:0% +at the heart of it okay so this idea of + + + align:start position:0% +at the heart of it okay so this idea of +the red the Red Queen hypothesis is um + + align:start position:0% +the red the Red Queen hypothesis is um + + + align:start position:0% +the red the Red Queen hypothesis is um +all right so let me see if I can find + + align:start position:0% +all right so let me see if I can find + + + align:start position:0% +all right so let me see if I can find +the actual quote for you guys U maybe + + align:start position:0% +the actual quote for you guys U maybe + + + align:start position:0% +the actual quote for you guys U maybe +not um so it's from a Lewis car novel + + align:start position:0% +not um so it's from a Lewis car novel + + + align:start position:0% +not um so it's from a Lewis car novel +Through the Looking Glass the quote was + + align:start position:0% +Through the Looking Glass the quote was + + + align:start position:0% +Through the Looking Glass the quote was +something you have to run is oh shoot + + align:start position:0% + + + + align:start position:0% + +um all right never mind okay I can't + + align:start position:0% +um all right never mind okay I can't + + + align:start position:0% +um all right never mind okay I can't +remember what the quote was um but + + align:start position:0% +remember what the quote was um but + + + align:start position:0% +remember what the quote was um but +um the idea the idea is that sexual + + align:start position:0% +um the idea the idea is that sexual + + + align:start position:0% +um the idea the idea is that sexual +reproduction may allow a population to + + align:start position:0% +reproduction may allow a population to + + + align:start position:0% +reproduction may allow a population to +adapt against say changing environments + + align:start position:0% +adapt against say changing environments + + + align:start position:0% +adapt against say changing environments +more rapidly okay and and this has a + + align:start position:0% +more rapidly okay and and this has a + + + align:start position:0% +more rapidly okay and and this has a +couple of reasons because you generate + + align:start position:0% +couple of reasons because you generate + + + align:start position:0% +couple of reasons because you generate +genetic diversity um you you don't have + + align:start position:0% +genetic diversity um you you don't have + + + align:start position:0% +genetic diversity um you you don't have +the same clone interference kinds of + + align:start position:0% +the same clone interference kinds of + + + align:start position:0% +the same clone interference kinds of +effects that we talked about earlier all + + align:start position:0% +effects that we talked about earlier all + + + align:start position:0% +effects that we talked about earlier all +right so if you have asexual lineages + + align:start position:0% +right so if you have asexual lineages + + + align:start position:0% +right so if you have asexual lineages +then if you have two beneficial + + align:start position:0% +then if you have two beneficial + + + align:start position:0% +then if you have two beneficial +mutations they cannot both fix right so + + align:start position:0% +mutations they cannot both fix right so + + + align:start position:0% +mutations they cannot both fix right so +the more fit version is going to fix and + + align:start position:0% +the more fit version is going to fix and + + + align:start position:0% +the more fit version is going to fix and +then you have to wait for the next one + + align:start position:0% +then you have to wait for the next one + + + align:start position:0% +then you have to wait for the next one +right whereas in sexually reproducing + + align:start position:0% +right whereas in sexually reproducing + + + align:start position:0% +right whereas in sexually reproducing +populations the um those genes can + + align:start position:0% +populations the um those genes can + + + align:start position:0% +populations the um those genes can +spread throughout the population sort of + + align:start position:0% +spread throughout the population sort of + + + align:start position:0% +spread throughout the population sort of +as genes rather than being tied to a + + align:start position:0% +as genes rather than being tied to a + + + align:start position:0% +as genes rather than being tied to a +particular individual okay so that means + + align:start position:0% +particular individual okay so that means + + + align:start position:0% +particular individual okay so that means +that if you find yourself in a new + + align:start position:0% +that if you find yourself in a new + + + align:start position:0% +that if you find yourself in a new +environment it may be the case that + + align:start position:0% +environment it may be the case that + + + align:start position:0% +environment it may be the case that +sexual reproduction can allow for the + + align:start position:0% +sexual reproduction can allow for the + + + align:start position:0% +sexual reproduction can allow for the +population to adapt more rapidly but + + align:start position:0% +population to adapt more rapidly but + + + align:start position:0% +population to adapt more rapidly but +what's you know on one hand you might + + align:start position:0% +what's you know on one hand you might + + + align:start position:0% +what's you know on one hand you might +say well the environment's always + + align:start position:0% +say well the environment's always + + + align:start position:0% +say well the environment's always +changing so that can always favor the + + align:start position:0% +changing so that can always favor the + + + align:start position:0% +changing so that can always favor the +sexually reproducing populations but + + align:start position:0% +sexually reproducing populations but + + + align:start position:0% +sexually reproducing populations but +then there's a feeling out there that + + align:start position:0% +then there's a feeling out there that + + + align:start position:0% +then there's a feeling out there that +maybe that's not enough in the sense + + align:start position:0% +maybe that's not enough in the sense + + + align:start position:0% +maybe that's not enough in the sense +that the environment is not changing + + align:start position:0% +that the environment is not changing + + + align:start position:0% +that the environment is not changing +rapidly enough and dramatically enough + + align:start position:0% +rapidly enough and dramatically enough + + + align:start position:0% +rapidly enough and dramatically enough +to force uh the population to um + + align:start position:0% +to force uh the population to um + + + align:start position:0% +to force uh the population to um +reproduce sexually as compared to + + align:start position:0% +reproduce sexually as compared to + + + align:start position:0% +reproduce sexually as compared to +asexually right um and so the the the + + align:start position:0% +asexually right um and so the the the + + + align:start position:0% +asexually right um and so the the the +proposal from the Red Queen hypothesis + + align:start position:0% +proposal from the Red Queen hypothesis + + + align:start position:0% +proposal from the Red Queen hypothesis +is that the the the constantly changing + + align:start position:0% +is that the the the constantly changing + + + align:start position:0% +is that the the the constantly changing +environment is a result of co-evolution + + align:start position:0% +environment is a result of co-evolution + + + align:start position:0% +environment is a result of co-evolution +between host + + align:start position:0% +between host + + + align:start position:0% +between host +and they're parasites right because + + align:start position:0% +and they're parasites right because + + + align:start position:0% +and they're parasites right because +parasites are always trying to Target uh + + align:start position:0% +parasites are always trying to Target uh + + + align:start position:0% +parasites are always trying to Target uh +kind of common host genotypes because + + align:start position:0% +kind of common host genotypes because + + + align:start position:0% +kind of common host genotypes because +that they can spread on those right so + + align:start position:0% +that they can spread on those right so + + + align:start position:0% +that they can spread on those right so +they're always the parasites are + + align:start position:0% +they're always the parasites are + + + align:start position:0% +they're always the parasites are +evolving but then the host is sort of + + align:start position:0% +evolving but then the host is sort of + + + align:start position:0% +evolving but then the host is sort of +being host population or genotypes are + + align:start position:0% +being host population or genotypes are + + + align:start position:0% +being host population or genotypes are +kind of being chased Away by those + + align:start position:0% +kind of being chased Away by those + + + align:start position:0% +kind of being chased Away by those +parasites that are targeting them right + + align:start position:0% +parasites that are targeting them right + + + align:start position:0% +parasites that are targeting them right +so the the notion is that parasites as a + + align:start position:0% +so the the notion is that parasites as a + + + align:start position:0% +so the the notion is that parasites as a +result of this coevolution can be the + + align:start position:0% +result of this coevolution can be the + + + align:start position:0% +result of this coevolution can be the +source for the constantly changing + + align:start position:0% +source for the constantly changing + + + align:start position:0% +source for the constantly changing +environment that may be driving U the + + align:start position:0% +environment that may be driving U the + + + align:start position:0% +environment that may be driving U the +evolution of sex yeah + + align:start position:0% +evolution of sex yeah + + + align:start position:0% +evolution of sex yeah +question I would isia + + align:start position:0% + + + + align:start position:0% + +also that's + + align:start position:0% + + + + align:start position:0% + +right yes right so so the question is + + align:start position:0% +right yes right so so the question is + + + align:start position:0% +right yes right so so the question is +why you know + + align:start position:0% +why you know + + + align:start position:0% +why you know +if yeah right um okay so I can give you + + align:start position:0% +if yeah right um okay so I can give you + + + align:start position:0% +if yeah right um okay so I can give you +my best guess on this all right first of + + align:start position:0% +my best guess on this all right first of + + + align:start position:0% +my best guess on this all right first of +all I saying not everybody agrees that + + align:start position:0% +all I saying not everybody agrees that + + + align:start position:0% +all I saying not everybody agrees that +that the Red Queen kind of hypothesis is + + align:start position:0% +that the Red Queen kind of hypothesis is + + + align:start position:0% +that the Red Queen kind of hypothesis is +the sort of true explanation if a true + + align:start position:0% +the sort of true explanation if a true + + + align:start position:0% +the sort of true explanation if a true +explanation even exists right um but + + align:start position:0% +explanation even exists right um but + + + align:start position:0% +explanation even exists right um but +within this framework uh you you you + + align:start position:0% +within this framework uh you you you + + + align:start position:0% +within this framework uh you you you +definitely want to try to explain why it + + align:start position:0% +definitely want to try to explain why it + + + align:start position:0% +definitely want to try to explain why it +is that uh kind of large life forms seem + + align:start position:0% +is that uh kind of large life forms seem + + + align:start position:0% +is that uh kind of large life forms seem +to have a lot of obligate sexual + + align:start position:0% +to have a lot of obligate sexual + + + align:start position:0% +to have a lot of obligate sexual +reproduction right because this is a + + align:start position:0% +reproduction right because this is a + + + align:start position:0% +reproduction right because this is a +very strong pattern that you see right + + align:start position:0% +very strong pattern that you see right + + + align:start position:0% +very strong pattern that you see right +uh and I guess what I would say is that + + align:start position:0% +uh and I guess what I would say is that + + + align:start position:0% +uh and I guess what I would say is that +there's certainly a correlation between + + align:start position:0% +there's certainly a correlation between + + + align:start position:0% +there's certainly a correlation between +size uh physical size and um and + + align:start position:0% +size uh physical size and um and + + + align:start position:0% +size uh physical size and um and +generation time right and that + + align:start position:0% +generation time right and that + + + align:start position:0% +generation time right and that +generation time tells you about + + align:start position:0% +generation time tells you about + + + align:start position:0% +generation time tells you about +something about the typical time scales + + align:start position:0% +something about the typical time scales + + + align:start position:0% +something about the typical time scales +over which you can evolve right so my + + align:start position:0% +over which you can evolve right so my + + + align:start position:0% +over which you can evolve right so my +sense of this is it just maybe that uh + + align:start position:0% +sense of this is it just maybe that uh + + + align:start position:0% +sense of this is it just maybe that uh +that animals you know in general you + + align:start position:0% +that animals you know in general you + + + align:start position:0% +that animals you know in general you +know large animals they by their nature + + align:start position:0% +know large animals they by their nature + + + align:start position:0% +know large animals they by their nature +will evolve rather slowly as compared to + + align:start position:0% +will evolve rather slowly as compared to + + + align:start position:0% +will evolve rather slowly as compared to +their their parasites and so that means + + align:start position:0% +their their parasites and so that means + + + align:start position:0% +their their parasites and so that means +that they are kind of the populations + + align:start position:0% +that they are kind of the populations + + + align:start position:0% +that they are kind of the populations +that are most in need of evolving um of + + align:start position:0% +that are most in need of evolving um of + + + align:start position:0% +that are most in need of evolving um of +of speeding up their + + align:start position:0% +of speeding up their + + + align:start position:0% +of speeding up their +evolution um and it's hard to know how + + align:start position:0% +evolution um and it's hard to know how + + + align:start position:0% +evolution um and it's hard to know how +convincing that argument should be but + + align:start position:0% +convincing that argument should be but + + + align:start position:0% +convincing that argument should be but +yeah yes what's the what's the + + align:start position:0% +yeah yes what's the what's the + + + align:start position:0% +yeah yes what's the what's the +difference in in + + align:start position:0% +difference in in + + + align:start position:0% +difference in in +reproductive time between + + align:start position:0% +reproductive time between + + + align:start position:0% +reproductive time between +bacteria yeah right uh okay so yeah so + + align:start position:0% +bacteria yeah right uh okay so yeah so + + + align:start position:0% +bacteria yeah right uh okay so yeah so +bacteria can well as we were discuss as + + align:start position:0% +bacteria can well as we were discuss as + + + align:start position:0% +bacteria can well as we were discuss as +we've discussed uh division times are + + align:start position:0% +we've discussed uh division times are + + + align:start position:0% +we've discussed uh division times are +kind of order hour and Fage uh I think + + align:start position:0% +kind of order hour and Fage uh I think + + + align:start position:0% +kind of order hour and Fage uh I think +yeah so when you get a Fage + + align:start position:0% +yeah so when you get a Fage + + + align:start position:0% +yeah so when you get a Fage +infection uh so what happens is the Fage + + align:start position:0% +infection uh so what happens is the Fage + + + align:start position:0% +infection uh so what happens is the Fage +you can infect as a single Fage and then + + align:start position:0% +you can infect as a single Fage and then + + + align:start position:0% +you can infect as a single Fage and then +uh they will generate uh burst they + + align:start position:0% +uh they will generate uh burst they + + + align:start position:0% +uh they will generate uh burst they +they'll kind of divide within the + + align:start position:0% +they'll kind of divide within the + + + align:start position:0% +they'll kind of divide within the +bacterial bacterial cell and then burst + + align:start position:0% +bacterial bacterial cell and then burst + + + align:start position:0% +bacterial bacterial cell and then burst +out as a population of um you know 100 + + align:start position:0% +out as a population of um you know 100 + + + align:start position:0% +out as a population of um you know 100 +200 kind of tle F and I think that that + + align:start position:0% +200 kind of tle F and I think that that + + + align:start position:0% +200 kind of tle F and I think that that +that might take you know four five hours + + align:start position:0% +that might take you know four five hours + + + align:start position:0% +that might take you know four five hours +is kind of my sense right so it's I'd + + align:start position:0% +is kind of my sense right so it's I'd + + + align:start position:0% +is kind of my sense right so it's I'd +say that um and then and then they go + + align:start position:0% +say that um and then and then they go + + + align:start position:0% +say that um and then and then they go +off and they find they find new bacteria + + align:start position:0% +off and they find they find new bacteria + + + align:start position:0% +off and they find they find new bacteria +so in that sense they they may have yeah + + align:start position:0% +so in that sense they they may have yeah + + + align:start position:0% +so in that sense they they may have yeah +so it's it's a little bit faster than + + align:start position:0% +so it's it's a little bit faster than + + + align:start position:0% +so it's it's a little bit faster than +the bacteria I'd say + + align:start position:0% + + + + align:start position:0% + +yeah okay right so what um Can somebody + + align:start position:0% +yeah okay right so what um Can somebody + + + align:start position:0% +yeah okay right so what um Can somebody +say what the core experiment was that + + align:start position:0% +say what the core experiment was that + + + align:start position:0% +say what the core experiment was that +they did in in this experiment + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +yes + + align:start position:0% + + + + align:start position:0% + +that's right so there there going to be + + align:start position:0% +that's right so there there going to be + + + align:start position:0% +that's right so there there going to be +um so this worm seagon it's sort of a + + align:start position:0% +um so this worm seagon it's sort of a + + + align:start position:0% +um so this worm seagon it's sort of a +millimeter in size right and they're + + align:start position:0% +millimeter in size right and they're + + + align:start position:0% +millimeter in size right and they're +going to be three different conditions + + align:start position:0% +going to be three different conditions + + + align:start position:0% +going to be three different conditions +one is there there's kind of the um the + + align:start position:0% +one is there there's kind of the um the + + + align:start position:0% +one is there there's kind of the um the +while type that can uh can outcross can + + align:start position:0% +while type that can uh can outcross can + + + align:start position:0% +while type that can uh can outcross can +can have males mate some that are then + + align:start position:0% +can have males mate some that are then + + + align:start position:0% +can have males mate some that are then +there's the + + align:start position:0% +there's the + + + align:start position:0% +there's the +obligate outcrossing which means there's + + align:start position:0% +obligate outcrossing which means there's + + + align:start position:0% +obligate outcrossing which means there's +they they're going to be it's they have + + align:start position:0% +they they're going to be it's they have + + + align:start position:0% +they they're going to be it's they have +to mate with males and then there's the + + align:start position:0% +to mate with males and then there's the + + + align:start position:0% +to mate with males and then there's the +uh the obligate um what do they call it + + align:start position:0% +uh the obligate um what do they call it + + + align:start position:0% +uh the obligate um what do they call it +not not obligate selfing obligate + + align:start position:0% +not not obligate selfing obligate + + + align:start position:0% +not not obligate selfing obligate +selfing + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +okay + + align:start position:0% + + + + align:start position:0% + +okay and then what do they do with those + + align:start position:0% +okay and then what do they do with those + + + align:start position:0% +okay and then what do they do with those +worms + + align:start position:0% + + + + align:start position:0% + +that's right so then there's a bacterial + + align:start position:0% +that's right so then there's a bacterial + + + align:start position:0% +that's right so then there's a bacterial +pathogen Sera morassin that um and + + align:start position:0% +pathogen Sera morassin that um and + + + align:start position:0% +pathogen Sera morassin that um and +they're going to have these three + + align:start position:0% +they're going to have these three + + + align:start position:0% +they're going to have these three +different conditions right where they're + + align:start position:0% +different conditions right where they're + + + align:start position:0% +different conditions right where they're +going to uh for the for the SM the + + align:start position:0% +going to uh for the for the SM the + + + align:start position:0% +going to uh for the for the SM the +bacteria they're either going to have uh + + align:start position:0% +bacteria they're either going to have uh + + + align:start position:0% +bacteria they're either going to have uh +they're going to allow for + + align:start position:0% + + + + align:start position:0% + +co-evolution uh where they take the + + align:start position:0% +co-evolution uh where they take the + + + align:start position:0% +co-evolution uh where they take the +bacteria from each of the infections and + + align:start position:0% +bacteria from each of the infections and + + + align:start position:0% +bacteria from each of the infections and +prop + + align:start position:0% +prop + + + align:start position:0% +prop +or they're going to do kind of the the + + align:start position:0% +or they're going to do kind of the the + + + align:start position:0% +or they're going to do kind of the the +no Evolution where you just compete + + align:start position:0% +no Evolution where you just compete + + + align:start position:0% +no Evolution where you just compete +against the the ancestor right and + + align:start position:0% +against the the ancestor right and + + + align:start position:0% +against the the ancestor right and +there's also control okay so there's + + align:start position:0% +there's also control okay so there's + + + align:start position:0% +there's also control okay so there's +coevolution there's kind of this no + + align:start position:0% +coevolution there's kind of this no + + + align:start position:0% +coevolution there's kind of this no +evolution of the of the bacteria and + + align:start position:0% +evolution of the of the bacteria and + + + align:start position:0% +evolution of the of the bacteria and +then there's also control where there's + + align:start position:0% +then there's also control where there's + + + align:start position:0% +then there's also control where there's +no + + align:start position:0% + + + + align:start position:0% + +bacteria + + align:start position:0% + + + + align:start position:0% + +right and what was the most striking + + align:start position:0% +right and what was the most striking + + + align:start position:0% +right and what was the most striking +thing that they saw in this experiment + + align:start position:0% + + + + align:start position:0% + +guess that's right right so if you + + align:start position:0% +guess that's right right so if you + + + align:start position:0% +guess that's right right so if you +allowed the bacteria to to be evolving + + align:start position:0% +allowed the bacteria to to be evolving + + + align:start position:0% +allowed the bacteria to to be evolving +against this obligately selfing + + align:start position:0% +against this obligately selfing + + + align:start position:0% +against this obligately selfing +population this this + + align:start position:0% +population this this + + + align:start position:0% +population this this +killed uh this killed the worms + + align:start position:0% +killed uh this killed the worms + + + align:start position:0% +killed uh this killed the worms +right and what was the other thing that + + align:start position:0% +right and what was the other thing that + + + align:start position:0% +right and what was the other thing that +was maybe very striking about their + + align:start position:0% +was maybe very striking about their + + + align:start position:0% +was maybe very striking about their +experiment + + align:start position:0% + + + + align:start position:0% + +yeah yeah so this was this was kind of + + align:start position:0% +yeah yeah so this was this was kind of + + + align:start position:0% +yeah yeah so this was this was kind of +amazing right so they saw as a function + + align:start position:0% +amazing right so they saw as a function + + + align:start position:0% +amazing right so they saw as a function +of time if you look at outc + + align:start position:0% +of time if you look at outc + + + align:start position:0% +of time if you look at outc +Crossing so kind of the rate of mating + + align:start position:0% +Crossing so kind of the rate of mating + + + align:start position:0% +Crossing so kind of the rate of mating +with the males this started out at kind + + align:start position:0% +with the males this started out at kind + + + align:start position:0% +with the males this started out at kind +of like 0 + + align:start position:0% +of like 0 + + + align:start position:0% +of like 0 +2 U and then in the presence of the + + align:start position:0% +2 U and then in the presence of the + + + align:start position:0% +2 U and then in the presence of the +co-evolution it kind of went up and it + + align:start position:0% +co-evolution it kind of went up and it + + + align:start position:0% +co-evolution it kind of went up and it +goes up to 80 you know maybe 80% + + align:start position:0% +goes up to 80 you know maybe 80% + + + align:start position:0% +goes up to 80 you know maybe 80% +okay and for Co Evolution it stayed up + + align:start position:0% +okay and for Co Evolution it stayed up + + + align:start position:0% +okay and for Co Evolution it stayed up +high whereas if the wild + + align:start position:0% +high whereas if the wild + + + align:start position:0% +high whereas if the wild +type uh if the wild type worms if they + + align:start position:0% +type uh if the wild type worms if they + + + align:start position:0% +type uh if the wild type worms if they +continued to be just challenged by The + + align:start position:0% +continued to be just challenged by The + + + align:start position:0% +continued to be just challenged by The +ancestral + + align:start position:0% +ancestral + + + align:start position:0% +ancestral +bacteria it initially came up but then + + align:start position:0% +bacteria it initially came up but then + + + align:start position:0% +bacteria it initially came up but then +it came back down so this is the + + align:start position:0% + + + + align:start position:0% + +co-evolution and this is um this is the + + align:start position:0% +co-evolution and this is um this is the + + + align:start position:0% +co-evolution and this is um this is the +ancestral uh the ancestral uh + + align:start position:0% +ancestral uh the ancestral uh + + + align:start position:0% +ancestral uh the ancestral uh +SM right so that there was a sense that + + align:start position:0% +SM right so that there was a sense that + + + align:start position:0% +SM right so that there was a sense that +that wild type population and initially + + align:start position:0% +that wild type population and initially + + + align:start position:0% +that wild type population and initially +out it evolved to outcross more but then + + align:start position:0% +out it evolved to outcross more but then + + + align:start position:0% +out it evolved to outcross more but then +once it had solved this problem of how + + align:start position:0% +once it had solved this problem of how + + + align:start position:0% +once it had solved this problem of how +to handle the ancestral sertia the + + align:start position:0% +to handle the ancestral sertia the + + + align:start position:0% +to handle the ancestral sertia the +outcrossing rate went back down right um + + align:start position:0% +outcrossing rate went back down right um + + + align:start position:0% +outcrossing rate went back down right um +so we we are um pretty much out of time + + align:start position:0% +so we we are um pretty much out of time + + + align:start position:0% +so we we are um pretty much out of time +but I do want to I don't know if you + + align:start position:0% +but I do want to I don't know if you + + + align:start position:0% +but I do want to I don't know if you +guys noticed the last sentence of the + + align:start position:0% +guys noticed the last sentence of the + + + align:start position:0% +guys noticed the last sentence of the +paper it is amazing that they got this + + align:start position:0% +paper it is amazing that they got this + + + align:start position:0% +paper it is amazing that they got this +through um through the publication + + align:start position:0% +through um through the publication + + + align:start position:0% +through um through the publication +process right + + align:start position:0% +process right + + + align:start position:0% +process right +um all right so you know so they say + + align:start position:0% +um all right so you know so they say + + + align:start position:0% +um all right so you know so they say +taken together the results demonstrate + + align:start position:0% +taken together the results demonstrate + + + align:start position:0% +taken together the results demonstrate +that sex can facilitate adaptation to + + align:start position:0% +that sex can facilitate adaptation to + + + align:start position:0% +that sex can facilitate adaptation to +novel envir ments but the long-term + + align:start position:0% +novel envir ments but the long-term + + + align:start position:0% +novel envir ments but the long-term +maintenance of sex requires that the + + align:start position:0% +maintenance of sex requires that the + + + align:start position:0% +maintenance of sex requires that the +novelty does not wear + + align:start position:0% +novelty does not wear + + + align:start position:0% +novelty does not wear +off I you know it's one it's one of + + align:start position:0% +off I you know it's one it's one of + + + align:start position:0% +off I you know it's one it's one of +those things that you read and you you + + align:start position:0% +those things that you read and you you + + + align:start position:0% +those things that you read and you you +you you you think okay so I will leave I + + align:start position:0% +you you you think okay so I will leave I + + + align:start position:0% +you you you think okay so I will leave I +will leave that sentence with you and + + align:start position:0% +will leave that sentence with you and + + + align:start position:0% +will leave that sentence with you and +then um we'll uh we'll uh meet on + + align:start position:0% +then um we'll uh we'll uh meet on + + + align:start position:0% +then um we'll uh we'll uh meet on +Tuesday okay \ No newline at end of file diff --git a/E7oR_JBgUzA.txt b/E7oR_JBgUzA.txt new file mode 100644 index 0000000000000000000000000000000000000000..860ab0fdea89d99aed0a8fb84bfd35ff688e0253 --- /dev/null +++ b/E7oR_JBgUzA.txt @@ -0,0 +1,3587 @@ +align:start position:0% + +welcome back to recitation in this video + + align:start position:0% +welcome back to recitation in this video + + + align:start position:0% +welcome back to recitation in this video +I'd like us to do two things the first + + align:start position:0% +I'd like us to do two things the first + + + align:start position:0% +I'd like us to do two things the first +thing we're going to do is we're going + + align:start position:0% +thing we're going to do is we're going + + + align:start position:0% +thing we're going to do is we're going +to graph the curve r equal 1 plus cosine + + align:start position:0% +to graph the curve r equal 1 plus cosine + + + align:start position:0% +to graph the curve r equal 1 plus cosine +Theta over 2 for Theta between 0 and 4 + + align:start position:0% +Theta over 2 for Theta between 0 and 4 + + + align:start position:0% +Theta over 2 for Theta between 0 and 4 +pi and we're going to graph it in the XY + + align:start position:0% +pi and we're going to graph it in the XY + + + align:start position:0% +pi and we're going to graph it in the XY +plane and then after we've done that + + align:start position:0% +plane and then after we've done that + + + align:start position:0% +plane and then after we've done that +we're going to take a look at some some + + align:start position:0% +we're going to take a look at some some + + + align:start position:0% +we're going to take a look at some some +components of that curve and we're going + + align:start position:0% +components of that curve and we're going + + + align:start position:0% +components of that curve and we're going +to calculate the area of some some + + align:start position:0% +to calculate the area of some some + + + align:start position:0% +to calculate the area of some some +components that close up so what I'd + + align:start position:0% +components that close up so what I'd + + + align:start position:0% +components that close up so what I'd +like you to do first is get a good + + align:start position:0% +like you to do first is get a good + + + align:start position:0% +like you to do first is get a good +picture of this curve uh in the XY plane + + align:start position:0% +picture of this curve uh in the XY plane + + + align:start position:0% +picture of this curve uh in the XY plane +I'll give you a little while to do that + + align:start position:0% +I'll give you a little while to do that + + + align:start position:0% +I'll give you a little while to do that +so why don't you pause the video get a + + align:start position:0% +so why don't you pause the video get a + + + align:start position:0% +so why don't you pause the video get a +good picture of that curve then come + + align:start position:0% +good picture of that curve then come + + + align:start position:0% +good picture of that curve then come +back when you're ready and I'll show you + + align:start position:0% +back when you're ready and I'll show you + + + align:start position:0% +back when you're ready and I'll show you +how I graph it and then we'll get into + + align:start position:0% +how I graph it and then we'll get into + + + align:start position:0% +how I graph it and then we'll get into +these area + + align:start position:0% + + + + align:start position:0% + +problems okay welcome back so the goal + + align:start position:0% +problems okay welcome back so the goal + + + align:start position:0% +problems okay welcome back so the goal +again was to graph a certain curve + + align:start position:0% +again was to graph a certain curve + + + align:start position:0% +again was to graph a certain curve +described by R and Theta but in the XY + + align:start position:0% +described by R and Theta but in the XY + + + align:start position:0% +described by R and Theta but in the XY +plane and for Theta between zero and pi + + align:start position:0% +plane and for Theta between zero and pi + + + align:start position:0% +plane and for Theta between zero and pi +over4 and when I do these problems we uh + + align:start position:0% +over4 and when I do these problems we uh + + + align:start position:0% +over4 and when I do these problems we uh +we want to we want to make sure that we + + align:start position:0% +we want to we want to make sure that we + + + align:start position:0% +we want to we want to make sure that we +understand how R depends on Theta that's + + align:start position:0% +understand how R depends on Theta that's + + + align:start position:0% +understand how R depends on Theta that's +sort of the main goal to graph this + + align:start position:0% +sort of the main goal to graph this + + + align:start position:0% +sort of the main goal to graph this +curve so what I do actually is I look at + + align:start position:0% +curve so what I do actually is I look at + + + align:start position:0% +curve so what I do actually is I look at +this not in the XY plane which was what + + align:start position:0% +this not in the XY plane which was what + + + align:start position:0% +this not in the XY plane which was what +I said to do in the problem but I first + + align:start position:0% +I said to do in the problem but I first + + + align:start position:0% +I said to do in the problem but I first +look at it and what we see as the r + + align:start position:0% +look at it and what we see as the r + + + align:start position:0% +look at it and what we see as the r +Theta plane and what we mean by that is + + align:start position:0% +Theta plane and what we mean by that is + + + align:start position:0% +Theta plane and what we mean by that is +we're going to graph this just like we + + align:start position:0% +we're going to graph this just like we + + + align:start position:0% +we're going to graph this just like we +would if these this variable was X and + + align:start position:0% +would if these this variable was X and + + + align:start position:0% +would if these this variable was X and +this variable was y so we move out of + + align:start position:0% +this variable was y so we move out of + + + align:start position:0% +this variable was y so we move out of +move out of the what we know about how R + + align:start position:0% +move out of the what we know about how R + + + align:start position:0% +move out of the what we know about how R +relates to X and Y and how Theta relates + + align:start position:0% +relates to X and Y and how Theta relates + + + align:start position:0% +relates to X and Y and how Theta relates +to X and Y and we just look at how R + + align:start position:0% +to X and Y and we just look at how R + + + align:start position:0% +to X and Y and we just look at how R +relates to Theta so let me draw that + + align:start position:0% +relates to Theta so let me draw that + + + align:start position:0% +relates to Theta so let me draw that +first and we'll see if we can sort of + + align:start position:0% +first and we'll see if we can sort of + + + align:start position:0% +first and we'll see if we can sort of +understand what I mean by that and then + + align:start position:0% +understand what I mean by that and then + + + align:start position:0% +understand what I mean by that and then +we'll put that picture use those use + + align:start position:0% +we'll put that picture use those use + + + align:start position:0% +we'll put that picture use those use +that curve to put that into the XY plane + + align:start position:0% +that curve to put that into the XY plane + + + align:start position:0% +that curve to put that into the XY plane +okay so the first thing we + + align:start position:0% +okay so the first thing we + + + align:start position:0% +okay so the first thing we +do is I'm going to let this be the Theta + + align:start position:0% +do is I'm going to let this be the Theta + + + align:start position:0% +do is I'm going to let this be the Theta +axis and this be the r AIS and let's + + align:start position:0% +axis and this be the r AIS and let's + + + align:start position:0% +axis and this be the r AIS and let's +look at I want to write down over here + + align:start position:0% +look at I want to write down over here + + + align:start position:0% +look at I want to write down over here +what the uh what the equation is so I + + align:start position:0% +what the uh what the equation is so I + + + align:start position:0% +what the uh what the equation is so I +don't have to keep turning + + align:start position:0% + + + + align:start position:0% + +around so again this is not I don't want + + align:start position:0% +around so again this is not I don't want + + + align:start position:0% +around so again this is not I don't want +to think about this as the XY plane + + align:start position:0% +to think about this as the XY plane + + + align:start position:0% +to think about this as the XY plane +because in the XY plane Theta has + + align:start position:0% +because in the XY plane Theta has + + + align:start position:0% +because in the XY plane Theta has +certain values at each point that are + + align:start position:0% +certain values at each point that are + + + align:start position:0% +certain values at each point that are +that are fixed based on the angle but + + align:start position:0% +that are fixed based on the angle but + + + align:start position:0% +that are fixed based on the angle but +now I'm letting Theta vary in this + + align:start position:0% +now I'm letting Theta vary in this + + + align:start position:0% +now I'm letting Theta vary in this +direction and R is varying in this + + align:start position:0% +direction and R is varying in this + + + align:start position:0% +direction and R is varying in this +direction + + align:start position:0% +direction + + + align:start position:0% +direction +and my Theta I said was between 0 and pi + + align:start position:0% +and my Theta I said was between 0 and pi + + + align:start position:0% +and my Theta I said was between 0 and pi +over + + align:start position:0% +over + + + align:start position:0% +over +4 sorry not pi over 4 4 Pi zero and four + + align:start position:0% +4 sorry not pi over 4 4 Pi zero and four + + + align:start position:0% +4 sorry not pi over 4 4 Pi zero and four +Pi Pi four would be a very small + + align:start position:0% +Pi Pi four would be a very small + + + align:start position:0% +Pi Pi four would be a very small +component of this that I'm interested in + + align:start position:0% +component of this that I'm interested in + + + align:start position:0% +component of this that I'm interested in +and let's think about what what happens + + align:start position:0% +and let's think about what what happens + + + align:start position:0% +and let's think about what what happens +what kind of Transformations have been + + align:start position:0% +what kind of Transformations have been + + + align:start position:0% +what kind of Transformations have been +done to the normal cosine function so if + + align:start position:0% +done to the normal cosine function so if + + + align:start position:0% +done to the normal cosine function so if +I took the normal cosine function and I + + align:start position:0% +I took the normal cosine function and I + + + align:start position:0% +I took the normal cosine function and I +and I take it instead of cosine Theta I + + align:start position:0% +and I take it instead of cosine Theta I + + + align:start position:0% +and I take it instead of cosine Theta I +look at cosine Theta over 2 what that's + + align:start position:0% +look at cosine Theta over 2 what that's + + + align:start position:0% +look at cosine Theta over 2 what that's +doing is that's stretching it + + align:start position:0% +doing is that's stretching it + + + align:start position:0% +doing is that's stretching it +horizontally out so think about the + + align:start position:0% +horizontally out so think about the + + + align:start position:0% +horizontally out so think about the +period of the cosine function usually is + + align:start position:0% +period of the cosine function usually is + + + align:start position:0% +period of the cosine function usually is +2 pi but notice what happens when I put + + align:start position:0% +2 pi but notice what happens when I put + + + align:start position:0% +2 pi but notice what happens when I put +in 2 pi for Theta I'm getting cosine of + + align:start position:0% +in 2 pi for Theta I'm getting cosine of + + + align:start position:0% +in 2 pi for Theta I'm getting cosine of +pi if I want to get cosine of 2 pi I + + align:start position:0% +pi if I want to get cosine of 2 pi I + + + align:start position:0% +pi if I want to get cosine of 2 pi I +have to let Theta go to 4 Pi which is + + align:start position:0% +have to let Theta go to 4 Pi which is + + + align:start position:0% +have to let Theta go to 4 Pi which is +why I'm letting Theta be between Zer and + + align:start position:0% +why I'm letting Theta be between Zer and + + + align:start position:0% +why I'm letting Theta be between Zer and +four Pi so dividing dividing the input + + align:start position:0% +four Pi so dividing dividing the input + + + align:start position:0% +four Pi so dividing dividing the input +value by two doubles your period so the + + align:start position:0% +value by two doubles your period so the + + + align:start position:0% +value by two doubles your period so the +period is now 4 Pi so to get all the way + + align:start position:0% +period is now 4 Pi so to get all the way + + + align:start position:0% +period is now 4 Pi so to get all the way +through I'm going to have to go up to 4 + + align:start position:0% +through I'm going to have to go up to 4 + + + align:start position:0% +through I'm going to have to go up to 4 +pi so let me just make a 2 pi here + + align:start position:0% +pi so let me just make a 2 pi here + + + align:start position:0% +pi so let me just make a 2 pi here +there's about a 4 Pi here so here's + + align:start position:0% +there's about a 4 Pi here so here's + + + align:start position:0% +there's about a 4 Pi here so here's +around 3 pi and here's around + + align:start position:0% +around 3 pi and here's around + + + align:start position:0% +around 3 pi and here's around +Pi so that now instead of instead of the + + align:start position:0% +Pi so that now instead of instead of the + + + align:start position:0% +Pi so that now instead of instead of the +usual cosine function it's going to take + + align:start position:0% +usual cosine function it's going to take + + + align:start position:0% +usual cosine function it's going to take +twice as long to get all the way through + + align:start position:0% +twice as long to get all the way through + + + align:start position:0% +twice as long to get all the way through +that's one thing we know what else have + + align:start position:0% +that's one thing we know what else have + + + align:start position:0% +that's one thing we know what else have +we done to the usual cosine function we + + align:start position:0% +we done to the usual cosine function we + + + align:start position:0% +we done to the usual cosine function we +moved it up by one and so instead of + + align:start position:0% +moved it up by one and so instead of + + + align:start position:0% +moved it up by one and so instead of +starting out when when your input is + + align:start position:0% +starting out when when your input is + + + align:start position:0% +starting out when when your input is +zero starting out at height one when + + align:start position:0% +zero starting out at height one when + + + align:start position:0% +zero starting out at height one when +your input is zero you start out at at + + align:start position:0% +your input is zero you start out at at + + + align:start position:0% +your input is zero you start out at at +height 1+ one you start out at height + + align:start position:0% +height 1+ one you start out at height + + + align:start position:0% +height 1+ one you start out at height +two so in fact this function let + + align:start position:0% +two so in fact this function let + + + align:start position:0% +two so in fact this function let +me let me point out it's going to start + + align:start position:0% +me let me point out it's going to start + + + align:start position:0% +me let me point out it's going to start +at two which means it also is going to + + align:start position:0% +at two which means it also is going to + + + align:start position:0% +at two which means it also is going to +end over here because it's periodic it's + + align:start position:0% +end over here because it's periodic it's + + + align:start position:0% +end over here because it's periodic it's +going to end at two and let's think + + align:start position:0% +going to end at two and let's think + + + align:start position:0% +going to end at two and let's think +about what else we know we know that the + + align:start position:0% +about what else we know we know that the + + + align:start position:0% +about what else we know we know that the +usual cosine function goes down to + + align:start position:0% +usual cosine function goes down to + + + align:start position:0% +usual cosine function goes down to +negative 1 but I've added one to it so + + align:start position:0% +negative 1 but I've added one to it so + + + align:start position:0% +negative 1 but I've added one to it so +now it only goes down to + + align:start position:0% +now it only goes down to + + + align:start position:0% +now it only goes down to +zero okay hopefully that makes sense + + align:start position:0% +zero okay hopefully that makes sense + + + align:start position:0% +zero okay hopefully that makes sense +maybe I should even uh even + + align:start position:0% +maybe I should even uh even + + + align:start position:0% +maybe I should even uh even +on H I don't want to draw the actual + + align:start position:0% +on H I don't want to draw the actual + + + align:start position:0% +on H I don't want to draw the actual +cosine function again right on here but + + align:start position:0% +cosine function again right on here but + + + align:start position:0% +cosine function again right on here but +let me draw the regular cosine function + + align:start position:0% +let me draw the regular cosine function + + + align:start position:0% +let me draw the regular cosine function +here so we have it the regular cosine + + align:start position:0% +here so we have it the regular cosine + + + align:start position:0% +here so we have it the regular cosine +function because I keep talking about it + + align:start position:0% +function because I keep talking about it + + + align:start position:0% +function because I keep talking about it +does does something like this it goes at + + align:start position:0% +does does something like this it goes at + + + align:start position:0% +does does something like this it goes at +one here and it's at one again here and + + align:start position:0% +one here and it's at one again here and + + + align:start position:0% +one here and it's at one again here and +so it's at minus one at + + align:start position:0% +so it's at minus one at + + + align:start position:0% +so it's at minus one at +pi and so very roughly it looks + + align:start position:0% +pi and so very roughly it looks + + + align:start position:0% +pi and so very roughly it looks +something like this right so I keep + + align:start position:0% +something like this right so I keep + + + align:start position:0% +something like this right so I keep +referencing the cosine function so this + + align:start position:0% +referencing the cosine function so this + + + align:start position:0% +referencing the cosine function so this +is the part part I'm referencing so we + + align:start position:0% +is the part part I'm referencing so we + + + align:start position:0% +is the part part I'm referencing so we +have to stretch it by two and then shift + + align:start position:0% +have to stretch it by two and then shift + + + align:start position:0% +have to stretch it by two and then shift +it up by one and so we see what was it + + align:start position:0% +it up by one and so we see what was it + + + align:start position:0% +it up by one and so we see what was it +Pi at + + align:start position:0% +Pi at + + + align:start position:0% +Pi at +pi1 I'm now going to be at 2 pi + + align:start position:0% +pi1 I'm now going to be at 2 pi + + + align:start position:0% +pi1 I'm now going to be at 2 pi +0 and then where do these points go this + + align:start position:0% +0 and then where do these points go this + + + align:start position:0% +0 and then where do these points go this +was pi over 2 the x value is going to be + + align:start position:0% +was pi over 2 the x value is going to be + + + align:start position:0% +was pi over 2 the x value is going to be +doubled I'm going to be at pi and the Y + + align:start position:0% +doubled I'm going to be at pi and the Y + + + align:start position:0% +doubled I'm going to be at pi and the Y +value is going to go up by one so I'm at + + align:start position:0% +value is going to go up by one so I'm at + + + align:start position:0% +value is going to go up by one so I'm at +Pi one and 3 Pi 1 and so the Curve will + + align:start position:0% +Pi one and 3 Pi 1 and so the Curve will + + + align:start position:0% +Pi one and 3 Pi 1 and so the Curve will +look something like this + + align:start position:0% +look something like this + + + align:start position:0% +look something like this +I'm not an expert here but hopefully + + align:start position:0% +I'm not an expert here but hopefully + + + align:start position:0% +I'm not an expert here but hopefully +that looks something like the cosine + + align:start position:0% +that looks something like the cosine + + + align:start position:0% +that looks something like the cosine +function + + align:start position:0% +function + + + align:start position:0% +function +but with a stretch and a and a shift so + + align:start position:0% +but with a stretch and a and a shift so + + + align:start position:0% +but with a stretch and a and a shift so +that is the curve r equal 1 + cosine + + align:start position:0% +that is the curve r equal 1 + cosine + + + align:start position:0% +that is the curve r equal 1 + cosine +Theta / 2 in what we consider the the r + + align:start position:0% +Theta / 2 in what we consider the the r + + + align:start position:0% +Theta / 2 in what we consider the the r +Theta plane so Theta is varying in this + + align:start position:0% +Theta plane so Theta is varying in this + + + align:start position:0% +Theta plane so Theta is varying in this +direction and R is varying in this + + align:start position:0% +direction and R is varying in this + + + align:start position:0% +direction and R is varying in this +direction but how do I transfer that to + + align:start position:0% +direction but how do I transfer that to + + + align:start position:0% +direction but how do I transfer that to +the XY plane that's the real point point + + align:start position:0% +the XY plane that's the real point point + + + align:start position:0% +the XY plane that's the real point point +that I I want to make about this problem + + align:start position:0% +that I I want to make about this problem + + + align:start position:0% +that I I want to make about this problem +so let's look at what's happening in the + + align:start position:0% +so let's look at what's happening in the + + + align:start position:0% +so let's look at what's happening in the +XY plane so this will be X and this will + + align:start position:0% +XY plane so this will be X and this will + + + align:start position:0% +XY plane so this will be X and this will +be y let's pick some points and try and + + align:start position:0% +be y let's pick some points and try and + + + align:start position:0% +be y let's pick some points and try and +figure out what's happening so where is + + align:start position:0% +figure out what's happening so where is + + + align:start position:0% +figure out what's happening so where is +this point this is the point 0 comma 2 + + align:start position:0% +this point this is the point 0 comma 2 + + + align:start position:0% +this point this is the point 0 comma 2 +when Theta is zero R equals 2 where is + + align:start position:0% +when Theta is zero R equals 2 where is + + + align:start position:0% +when Theta is zero R equals 2 where is +Theta equal to zero in this picture it's + + align:start position:0% +Theta equal to zero in this picture it's + + + align:start position:0% +Theta equal to zero in this picture it's +in the X direction right that's theta + + align:start position:0% +in the X direction right that's theta + + + align:start position:0% +in the X direction right that's theta +equals + + align:start position:0% +equals + + + align:start position:0% +equals +z and also 2 pi and 4 Pi any any uh + + align:start position:0% +z and also 2 pi and 4 Pi any any uh + + + align:start position:0% +z and also 2 pi and 4 Pi any any uh +multiple of 2 pi is Theta is pointing in + + align:start position:0% +multiple of 2 pi is Theta is pointing in + + + align:start position:0% +multiple of 2 pi is Theta is pointing in +this direction and R equals 2 there so + + align:start position:0% +this direction and R equals 2 there so + + + align:start position:0% +this direction and R equals 2 there so +in a strange twist this is the point two + + align:start position:0% +in a strange twist this is the point two + + + align:start position:0% +in a strange twist this is the point two +on the XY plane but that's not gonna + + align:start position:0% +on the XY plane but that's not gonna + + + align:start position:0% +on the XY plane but that's not gonna +that's just a coincidence okay don't + + align:start position:0% +that's just a coincidence okay don't + + + align:start position:0% +that's just a coincidence okay don't +think oh I'm just going to flip the + + align:start position:0% +think oh I'm just going to flip the + + + align:start position:0% +think oh I'm just going to flip the +values everywhere that's not going to + + align:start position:0% +values everywhere that's not going to + + + align:start position:0% +values everywhere that's not going to +happen okay actually and also before I + + align:start position:0% +happen okay actually and also before I + + + align:start position:0% +happen okay actually and also before I +make a mistake I'm going to make this a + + align:start position:0% +make a mistake I'm going to make this a + + + align:start position:0% +make a mistake I'm going to make this a +little bit bigger I want it to be + + align:start position:0% +little bit bigger I want it to be + + + align:start position:0% +little bit bigger I want it to be +bigger so I don't want this to be two I + + align:start position:0% +bigger so I don't want this to be two I + + + align:start position:0% +bigger so I don't want this to be two I +want this to be one I'm going to make + + align:start position:0% +want this to be one I'm going to make + + + align:start position:0% +want this to be one I'm going to make +this two + + align:start position:0% +this two + + + align:start position:0% +this two +Z I want to have a little bigger + + align:start position:0% +Z I want to have a little bigger + + + align:start position:0% +Z I want to have a little bigger +picture okay so it's going to be + + align:start position:0% +picture okay so it's going to be + + + align:start position:0% +picture okay so it's going to be +two at theta equals 0 and r equal 2 is + + align:start position:0% +two at theta equals 0 and r equal 2 is + + + align:start position:0% +two at theta equals 0 and r equal 2 is +it ever going to hit this point again + + align:start position:0% +it ever going to hit this point again + + + align:start position:0% +it ever going to hit this point again +well it is and it's going to hit that + + align:start position:0% +well it is and it's going to hit that + + + align:start position:0% +well it is and it's going to hit that +point again because it's periodic and + + align:start position:0% +point again because it's periodic and + + + align:start position:0% +point again because it's periodic and +I've gone out to four Pi if I rotate all + + align:start position:0% +I've gone out to four Pi if I rotate all + + + align:start position:0% +I've gone out to four Pi if I rotate all +the way around I'm at 2 pi for Theta if + + align:start position:0% +the way around I'm at 2 pi for Theta if + + + align:start position:0% +the way around I'm at 2 pi for Theta if +I rotate all the way around again I'm at + + align:start position:0% +I rotate all the way around again I'm at + + + align:start position:0% +I rotate all the way around again I'm at +4 Pi for Theta and my radius there is + + align:start position:0% +4 Pi for Theta and my radius there is + + + align:start position:0% +4 Pi for Theta and my radius there is +two also so this two 0 happens again + + align:start position:0% +two also so this two 0 happens again + + + align:start position:0% +two also so this two 0 happens again +when I have this point so it's going to + + align:start position:0% +when I have this point so it's going to + + + align:start position:0% +when I have this point so it's going to +close up okay and then what else happens + + align:start position:0% +close up okay and then what else happens + + + align:start position:0% +close up okay and then what else happens +well as Theta is rotating let's take + + align:start position:0% +well as Theta is rotating let's take + + + align:start position:0% +well as Theta is rotating let's take +Theta between zero and Pi Theta rotates + + align:start position:0% +Theta between zero and Pi Theta rotates + + + align:start position:0% +Theta between zero and Pi Theta rotates +from 0 to Pi going like this notice + + align:start position:0% +from 0 to Pi going like this notice + + + align:start position:0% +from 0 to Pi going like this notice +what's happening to the R value the R + + align:start position:0% +what's happening to the R value the R + + + align:start position:0% +what's happening to the R value the R +value is going from two down to one now + + align:start position:0% +value is going from two down to one now + + + align:start position:0% +value is going from two down to one now +I'm not going to be totally + + align:start position:0% +I'm not going to be totally + + + align:start position:0% +I'm not going to be totally +exact but here's minus one okay in the + + align:start position:0% +exact but here's minus one okay in the + + + align:start position:0% +exact but here's minus one okay in the +XY plane I'm not going to be totally but + + align:start position:0% +XY plane I'm not going to be totally but + + + align:start position:0% +XY plane I'm not going to be totally but +this curve is going to look something + + align:start position:0% +this curve is going to look something + + + align:start position:0% +this curve is going to look something +like see there's two it's going to look + + align:start position:0% +like see there's two it's going to look + + + align:start position:0% +like see there's two it's going to look +something + + align:start position:0% + + + + align:start position:0% + +like oops I overshot we'll make that + + align:start position:0% +like oops I overshot we'll make that + + + align:start position:0% +like oops I overshot we'll make that +negative one something like this okay + + align:start position:0% +negative one something like this okay + + + align:start position:0% +negative one something like this okay +and what's the point the point is that I + + align:start position:0% +and what's the point the point is that I + + + align:start position:0% +and what's the point the point is that I +start at Radius 2 and by the time I get + + align:start position:0% +start at Radius 2 and by the time I get + + + align:start position:0% +start at Radius 2 and by the time I get +to theta equals Pi I've gone down until + + align:start position:0% +to theta equals Pi I've gone down until + + + align:start position:0% +to theta equals Pi I've gone down until +my radius is one this has radius one and + + align:start position:0% +my radius is one this has radius one and + + + align:start position:0% +my radius is one this has radius one and +angle + + align:start position:0% +angle + + + align:start position:0% +angle +Pi so that represents this part of the + + align:start position:0% +Pi so that represents this part of the + + + align:start position:0% +Pi so that represents this part of the +curve that's this part of the + + align:start position:0% +curve that's this part of the + + + align:start position:0% +curve that's this part of the +curve now what's what's nice about this + + align:start position:0% +curve now what's what's nice about this + + + align:start position:0% +curve now what's what's nice about this +drawing is that we know this part of the + + align:start position:0% +drawing is that we know this part of the + + + align:start position:0% +drawing is that we know this part of the +curve and this part of the curve should + + align:start position:0% +curve and this part of the curve should + + + align:start position:0% +curve and this part of the curve should +look exactly the same so once I've drawn + + align:start position:0% +look exactly the same so once I've drawn + + + align:start position:0% +look exactly the same so once I've drawn +half of this I'm going to know I'm going + + align:start position:0% +half of this I'm going to know I'm going + + + align:start position:0% +half of this I'm going to know I'm going +to know everything once I've gone from + + align:start position:0% +to know everything once I've gone from + + + align:start position:0% +to know everything once I've gone from +Zer to 2 pi I can just reflect it + + align:start position:0% +Zer to 2 pi I can just reflect it + + + align:start position:0% +Zer to 2 pi I can just reflect it +basically we'll see what I mean by + + align:start position:0% +basically we'll see what I mean by + + + align:start position:0% +basically we'll see what I mean by +reflect in this case but the same radi + + align:start position:0% +reflect in this case but the same radi + + + align:start position:0% +reflect in this case but the same radi +are happening again in some sort of + + align:start position:0% +are happening again in some sort of + + + align:start position:0% +are happening again in some sort of +symmetric f fashion Okay so we've got 0 + + align:start position:0% +symmetric f fashion Okay so we've got 0 + + + align:start position:0% +symmetric f fashion Okay so we've got 0 +to Pi now what happens between pi and 2 + + align:start position:0% +to Pi now what happens between pi and 2 + + + align:start position:0% +to Pi now what happens between pi and 2 +pi notice pi to 2 pi in the Theta + + align:start position:0% +pi notice pi to 2 pi in the Theta + + + align:start position:0% +pi notice pi to 2 pi in the Theta +Direction on the XY plane is I start in + + align:start position:0% +Direction on the XY plane is I start in + + + align:start position:0% +Direction on the XY plane is I start in +this direction I don't know if you can + + align:start position:0% +this direction I don't know if you can + + + align:start position:0% +this direction I don't know if you can +see that I'm starting let me come over + + align:start position:0% +see that I'm starting let me come over + + + align:start position:0% +see that I'm starting let me come over +this side I start in in this direction + + align:start position:0% +this side I start in in this direction + + + align:start position:0% +this side I start in in this direction +for pi and I'm going to rotate down this + + align:start position:0% +for pi and I'm going to rotate down this + + + align:start position:0% +for pi and I'm going to rotate down this +is 3 pi over 2 and this is 2 pi those + + align:start position:0% +is 3 pi over 2 and this is 2 pi those + + + align:start position:0% +is 3 pi over 2 and this is 2 pi those +are my angles so what are my radi well I + + align:start position:0% +are my angles so what are my radi well I + + + align:start position:0% +are my angles so what are my radi well I +start at I start at radius one and I'm + + align:start position:0% +start at I start at radius one and I'm + + + align:start position:0% +start at I start at radius one and I'm +going to radius Z + + align:start position:0% +going to radius Z + + + align:start position:0% +going to radius Z +and so what happens is I'm coming + + align:start position:0% +and so what happens is I'm coming + + + align:start position:0% +and so what happens is I'm coming +through + + align:start position:0% +through + + + align:start position:0% +through +this1 and I'm coming + + align:start position:0% +this1 and I'm coming + + + align:start position:0% +this1 and I'm coming +around and then by the time I get it's + + align:start position:0% +around and then by the time I get it's + + + align:start position:0% +around and then by the time I get it's +going to be something like this by the + + align:start position:0% +going to be something like this by the + + + align:start position:0% +going to be something like this by the +time I get to 2 pi my radius is zero now + + align:start position:0% +time I get to 2 pi my radius is zero now + + + align:start position:0% +time I get to 2 pi my radius is zero now +just to make sure this curve makes sense + + align:start position:0% +just to make sure this curve makes sense + + + align:start position:0% +just to make sure this curve makes sense +to you you could pick a place an angle + + align:start position:0% +to you you could pick a place an angle + + + align:start position:0% +to you you could pick a place an angle +maybe like right here I don't know if + + align:start position:0% +maybe like right here I don't know if + + + align:start position:0% +maybe like right here I don't know if +that's easy to see but maybe that angle + + align:start position:0% +that's easy to see but maybe that angle + + + align:start position:0% +that's easy to see but maybe that angle +right there that angle is between 3 pi + + align:start position:0% +right there that angle is between 3 pi + + + align:start position:0% +right there that angle is between 3 pi +over 2 and 2 pi is there positive radius + + align:start position:0% +over 2 and 2 pi is there positive radius + + + align:start position:0% +over 2 and 2 pi is there positive radius +there yeah there is positive radius + + align:start position:0% +there yeah there is positive radius + + + align:start position:0% +there yeah there is positive radius +there so in fact this curve does come + + align:start position:0% +there so in fact this curve does come + + + align:start position:0% +there so in fact this curve does come +into this fourth quadrant here and then + + align:start position:0% +into this fourth quadrant here and then + + + align:start position:0% +into this fourth quadrant here and then +curve back + + align:start position:0% +curve back + + + align:start position:0% +curve back +in okay it does curve back in all right + + align:start position:0% +in okay it does curve back in all right + + + align:start position:0% +in okay it does curve back in all right +so then what happens between two pi and + + align:start position:0% +so then what happens between two pi and + + + align:start position:0% +so then what happens between two pi and +3 Pi okay hopefully this this picture is + + align:start position:0% +3 Pi okay hopefully this this picture is + + + align:start position:0% +3 Pi okay hopefully this this picture is +clear so far I'm going to come back to + + align:start position:0% +clear so far I'm going to come back to + + + align:start position:0% +clear so far I'm going to come back to +the other side okay what happens between + + align:start position:0% +the other side okay what happens between + + + align:start position:0% +the other side okay what happens between +2 pi and 3 Pi 2 pi were here and 3 Pi + + align:start position:0% +2 pi and 3 Pi 2 pi were here and 3 Pi + + + align:start position:0% +2 pi and 3 Pi 2 pi were here and 3 Pi +we're back over here again and notice + + align:start position:0% +we're back over here again and notice + + + align:start position:0% +we're back over here again and notice +that the radius is going to be doing the + + align:start position:0% +that the radius is going to be doing the + + + align:start position:0% +that the radius is going to be doing the +same kind of growth that it did between + + align:start position:0% +same kind of growth that it did between + + + align:start position:0% +same kind of growth that it did between +2 pi and 3 pi as it did Decay from from + + align:start position:0% +2 pi and 3 pi as it did Decay from from + + + align:start position:0% +2 pi and 3 pi as it did Decay from from +PI to 2 pi okay because the radi now + + align:start position:0% +PI to 2 pi okay because the radi now + + + align:start position:0% +PI to 2 pi okay because the radi now +there's a symmetry with how the radi + + align:start position:0% +there's a symmetry with how the radi + + + align:start position:0% +there's a symmetry with how the radi +behave so from 2 pi to 3 Pi I start off + + align:start position:0% +behave so from 2 pi to 3 Pi I start off + + + align:start position:0% +behave so from 2 pi to 3 Pi I start off +with a with radius zero and I have a + + align:start position:0% +with a with radius zero and I have a + + + align:start position:0% +with a with radius zero and I have a +small radius and then once I get to uh 3 + + align:start position:0% +small radius and then once I get to uh 3 + + + align:start position:0% +small radius and then once I get to uh 3 +pi over here I'm G to have radius one + + align:start position:0% +pi over here I'm G to have radius one + + + align:start position:0% +pi over here I'm G to have radius one +again I'm going to be at radius one + + align:start position:0% +again I'm going to be at radius one + + + align:start position:0% +again I'm going to be at radius one +which is going to correspond to this + + align:start position:0% +which is going to correspond to this + + + align:start position:0% +which is going to correspond to this +point so I'm G to have exactly the same + + align:start position:0% +point so I'm G to have exactly the same + + + align:start position:0% +point so I'm G to have exactly the same +picture which is dangerous because I + + align:start position:0% +picture which is dangerous because I + + + align:start position:0% +picture which is dangerous because I +probably would do it wrong but I'll try + + align:start position:0% +probably would do it wrong but I'll try + + + align:start position:0% +probably would do it wrong but I'll try +and draw it this way and then talk about + + align:start position:0% +and draw it this way and then talk about + + + align:start position:0% +and draw it this way and then talk about +it hopefully that looks about the + + align:start position:0% +it hopefully that looks about the + + + align:start position:0% +it hopefully that looks about the +same so this this curve coming through + + align:start position:0% +same so this this curve coming through + + + align:start position:0% +same so this this curve coming through +here was from PI to 2 pi this curve + + align:start position:0% +here was from PI to 2 pi this curve + + + align:start position:0% +here was from PI to 2 pi this curve +coming through here was from 2 pi to 3 + + align:start position:0% +coming through here was from 2 pi to 3 + + + align:start position:0% +coming through here was from 2 pi to 3 +pi and then to finish it off 3 pi to 4 + + align:start position:0% +pi and then to finish it off 3 pi to 4 + + + align:start position:0% +pi and then to finish it off 3 pi to 4 +Pi is going to look like this curve here + + align:start position:0% +Pi is going to look like this curve here + + + align:start position:0% +Pi is going to look like this curve here +so I come through o this is where it + + align:start position:0% +so I come through o this is where it + + + align:start position:0% +so I come through o this is where it +starts to get really dangerous but let's + + align:start position:0% +starts to get really dangerous but let's + + + align:start position:0% +starts to get really dangerous but let's +say that's pretty close + + align:start position:0% +say that's pretty close + + + align:start position:0% +say that's pretty close +so there's my 3 pi to 4 Pi it's again + + align:start position:0% +so there's my 3 pi to 4 Pi it's again + + + align:start position:0% +so there's my 3 pi to 4 Pi it's again +the same growth the way it was decaying + + align:start position:0% +the same growth the way it was decaying + + + align:start position:0% +the same growth the way it was decaying +between zero and Pi so this is your + + align:start position:0% +between zero and Pi so this is your + + + align:start position:0% +between zero and Pi so this is your +picture in the r in the XY plane of the + + align:start position:0% +picture in the r in the XY plane of the + + + align:start position:0% +picture in the r in the XY plane of the +curve Ral 1 + cosine Theta over 2 now we + + align:start position:0% +curve Ral 1 + cosine Theta over 2 now we + + + align:start position:0% +curve Ral 1 + cosine Theta over 2 now we +haven't calculated any area problems yet + + align:start position:0% +haven't calculated any area problems yet + + + align:start position:0% +haven't calculated any area problems yet +so what I'd like us to do is I'm going + + align:start position:0% +so what I'd like us to do is I'm going + + + align:start position:0% +so what I'd like us to do is I'm going +to shade two regions and I want us to + + align:start position:0% +to shade two regions and I want us to + + + align:start position:0% +to shade two regions and I want us to +just write down the form the integral + + align:start position:0% +just write down the form the integral + + + align:start position:0% +just write down the form the integral +form to find the area for each of these + + align:start position:0% +form to find the area for each of these + + + align:start position:0% +form to find the area for each of these +regions so the first region of + + align:start position:0% +regions so the first region of + + + align:start position:0% +regions so the first region of +interest is the pink region I'm going to + + align:start position:0% +interest is the pink region I'm going to + + + align:start position:0% +interest is the pink region I'm going to +ask us to find the area of the pink + + align:start position:0% +ask us to find the area of the pink + + + align:start position:0% +ask us to find the area of the pink +region and then I'm going to ask us to + + align:start position:0% +region and then I'm going to ask us to + + + align:start position:0% +region and then I'm going to ask us to +find the area of everything else the + + align:start position:0% +find the area of everything else the + + + align:start position:0% +find the area of everything else the +blue + + align:start position:0% + + + + align:start position:0% + +region so let's think about how to do + + align:start position:0% +region so let's think about how to do + + + align:start position:0% +region so let's think about how to do +that and I think I'm going to have to + + align:start position:0% +that and I think I'm going to have to + + + align:start position:0% +that and I think I'm going to have to +come over to the other side to write + + align:start position:0% +come over to the other side to write + + + align:start position:0% +come over to the other side to write +down the integrals but I'll be coming + + align:start position:0% +down the integrals but I'll be coming + + + align:start position:0% +down the integrals but I'll be coming +back and forth so just to remind you + + align:start position:0% +back and forth so just to remind you + + + align:start position:0% +back and forth so just to remind you +what you saw in lecture was that da is + + align:start position:0% +what you saw in lecture was that da is + + + align:start position:0% +what you saw in lecture was that da is +equal to r2/ 2 D + + align:start position:0% +equal to r2/ 2 D + + + align:start position:0% +equal to r2/ 2 D +Theta that's what da is and so this is + + align:start position:0% +Theta that's what da is and so this is + + + align:start position:0% +Theta that's what da is and so this is +going to be an integral in Theta and we + + align:start position:0% +going to be an integral in Theta and we + + + align:start position:0% +going to be an integral in Theta and we +know what R is as a function of theta + + align:start position:0% +know what R is as a function of theta + + + align:start position:0% +know what R is as a function of theta +and so if I want to find actually I + + align:start position:0% +and so if I want to find actually I + + + align:start position:0% +and so if I want to find actually I +should + + align:start position:0% +should + + + align:start position:0% +should +even use my colors appropriately I + + align:start position:0% +even use my colors appropriately I + + + align:start position:0% +even use my colors appropriately I +should + + align:start position:0% +should + + + align:start position:0% +should +say area the pink area is going to be + + align:start position:0% +say area the pink area is going to be + + + align:start position:0% +say area the pink area is going to be +equal to an integral and I'm going to + + align:start position:0% +equal to an integral and I'm going to + + + align:start position:0% +equal to an integral and I'm going to +and I'm going to write the uh r s I know + + align:start position:0% +and I'm going to write the uh r s I know + + + align:start position:0% +and I'm going to write the uh r s I know +what R squ is it's 1 + cosine Theta over + + align:start position:0% +what R squ is it's 1 + cosine Theta over + + + align:start position:0% +what R squ is it's 1 + cosine Theta over +2 squared and then an over two D Theta + + align:start position:0% +2 squared and then an over two D Theta + + + align:start position:0% +2 squared and then an over two D Theta +and then what is important about this + + align:start position:0% +and then what is important about this + + + align:start position:0% +and then what is important about this +it's our bounds right our bounds are + + align:start position:0% +it's our bounds right our bounds are + + + align:start position:0% +it's our bounds right our bounds are +what's important and so let's go back + + align:start position:0% +what's important and so let's go back + + + align:start position:0% +what's important and so let's go back +and let's look at our picture what are + + align:start position:0% +and let's look at our picture what are + + + align:start position:0% +and let's look at our picture what are +the bounds on Theta for the pink region + + align:start position:0% +the bounds on Theta for the pink region + + + align:start position:0% +the bounds on Theta for the pink region +okay so where does that pink region + + align:start position:0% +okay so where does that pink region + + + align:start position:0% +okay so where does that pink region +start and stop and maybe we even need to + + align:start position:0% +start and stop and maybe we even need to + + + align:start position:0% +start and stop and maybe we even need to +look at this top graph also so if we + + align:start position:0% +look at this top graph also so if we + + + align:start position:0% +look at this top graph also so if we +think about it we we went from zero to + + align:start position:0% +think about it we we went from zero to + + + align:start position:0% +think about it we we went from zero to +Pi to get this outer curve so how do we + + align:start position:0% +Pi to get this outer curve so how do we + + + align:start position:0% +Pi to get this outer curve so how do we +get the inner curve the inner curve + + align:start position:0% +get the inner curve the inner curve + + + align:start position:0% +get the inner curve the inner curve +started at theta equals Pi went to here + + align:start position:0% +started at theta equals Pi went to here + + + align:start position:0% +started at theta equals Pi went to here +went to here that was theta equals 3 Pi + + align:start position:0% +went to here that was theta equals 3 Pi + + + align:start position:0% +went to here that was theta equals 3 Pi +so it went all the way from PI to 3 Pi + + align:start position:0% +so it went all the way from PI to 3 Pi + + + align:start position:0% +so it went all the way from PI to 3 Pi +now if you're paying if you're paying + + align:start position:0% +now if you're paying if you're paying + + + align:start position:0% +now if you're paying if you're paying +good attention you can say well + + align:start position:0% +good attention you can say well + + + align:start position:0% +good attention you can say well +Christine we know that this region is + + align:start position:0% +Christine we know that this region is + + + align:start position:0% +Christine we know that this region is +totally symmetric trick so why don't I + + align:start position:0% +totally symmetric trick so why don't I + + + align:start position:0% +totally symmetric trick so why don't I +just take the area from PI to 2 pi and + + align:start position:0% +just take the area from PI to 2 pi and + + + align:start position:0% +just take the area from PI to 2 pi and +multiply by two and you can you can do + + align:start position:0% +multiply by two and you can you can do + + + align:start position:0% +multiply by two and you can you can do +it either way so you can either take the + + align:start position:0% +it either way so you can either take the + + + align:start position:0% +it either way so you can either take the +integral from all the way from PI to 3 + + align:start position:0% +integral from all the way from PI to 3 + + + align:start position:0% +integral from all the way from PI to 3 +Pi which corresponds to starting at this + + align:start position:0% +Pi which corresponds to starting at this + + + align:start position:0% +Pi which corresponds to starting at this +angle going all the way around and + + align:start position:0% +angle going all the way around and + + + align:start position:0% +angle going all the way around and +coming back to there which takes you all + + align:start position:0% +coming back to there which takes you all + + + align:start position:0% +coming back to there which takes you all +the way around this curve or you can go + + align:start position:0% +the way around this curve or you can go + + + align:start position:0% +the way around this curve or you can go +from PI to two pi and multiply that by + + align:start position:0% +from PI to two pi and multiply that by + + + align:start position:0% +from PI to two pi and multiply that by +two so let me come back and let me write + + align:start position:0% +two so let me come back and let me write + + + align:start position:0% +two so let me come back and let me write +that down it's either pi to 3 + + align:start position:0% +that down it's either pi to 3 + + + align:start position:0% +that down it's either pi to 3 +Pi of this or you just write it as + + align:start position:0% +Pi of this or you just write it as + + + align:start position:0% +Pi of this or you just write it as +integral from PI to 2 pi and If I + + align:start position:0% +integral from PI to 2 pi and If I + + + align:start position:0% +integral from PI to 2 pi and If I +multiply this by two the two drops out + + align:start position:0% +multiply this by two the two drops out + + + align:start position:0% +multiply this by two the two drops out +the two in the denominator drops + + align:start position:0% + + + + align:start position:0% + +out I'm not going to solve this problem + + align:start position:0% +out I'm not going to solve this problem + + + align:start position:0% +out I'm not going to solve this problem +for you but I do want to point out the + + align:start position:0% +for you but I do want to point out the + + + align:start position:0% +for you but I do want to point out the +kinds of terms you would have you would + + align:start position:0% +kinds of terms you would have you would + + + align:start position:0% +kinds of terms you would have you would +have a constant term when you square + + align:start position:0% +have a constant term when you square + + + align:start position:0% +have a constant term when you square +this you would have a term that was two + + align:start position:0% +this you would have a term that was two + + + align:start position:0% +this you would have a term that was two +cosine Theta over two which is easy to + + align:start position:0% +cosine Theta over two which is easy to + + + align:start position:0% +cosine Theta over two which is easy to +integrate by a u substitution and then + + align:start position:0% +integrate by a u substitution and then + + + align:start position:0% +integrate by a u substitution and then +you would have a cosine squared Theta + + align:start position:0% +you would have a cosine squared Theta + + + align:start position:0% +you would have a cosine squared Theta +over 2 which you want to use the double + + align:start position:0% +over 2 which you want to use the double + + + align:start position:0% +over 2 which you want to use the double +angle formula or the half angle formula + + align:start position:0% +angle formula or the half angle formula + + + align:start position:0% +angle formula or the half angle formula +that you've seen used to manipulate + + align:start position:0% +that you've seen used to manipulate + + + align:start position:0% +that you've seen used to manipulate +these integrals that involve just a + + align:start position:0% +these integrals that involve just a + + + align:start position:0% +these integrals that involve just a +cosine squared or a s squared so that + + align:start position:0% +cosine squared or a s squared so that + + + align:start position:0% +cosine squared or a s squared so that +would be your strategy okay now let's + + align:start position:0% +would be your strategy okay now let's + + + align:start position:0% +would be your strategy okay now let's +look at the Blue + + align:start position:0% + + + + align:start position:0% + +Area okay so to find the blue area again + + align:start position:0% +Area okay so to find the blue area again + + + align:start position:0% +Area okay so to find the blue area again +I know all that matters is really the + + align:start position:0% +I know all that matters is really the + + + align:start position:0% +I know all that matters is really the +bounds we're going to see we have to do + + align:start position:0% +bounds we're going to see we have to do + + + align:start position:0% +bounds we're going to see we have to do +a little extra work + + align:start position:0% + + + + align:start position:0% + +but this is our first setup and now + + align:start position:0% +but this is our first setup and now + + + align:start position:0% +but this is our first setup and now +let's go look at the bounds okay so we + + align:start position:0% +let's go look at the bounds okay so we + + + align:start position:0% +let's go look at the bounds okay so we +go back to the + + align:start position:0% +go back to the + + + align:start position:0% +go back to the +curve all right what is the Blue Area + + align:start position:0% +curve all right what is the Blue Area + + + align:start position:0% +curve all right what is the Blue Area +well the blue + + align:start position:0% +well the blue + + + align:start position:0% +well the blue +area that's a little harder so let's see + + align:start position:0% +area that's a little harder so let's see + + + align:start position:0% +area that's a little harder so let's see +what happens if I were to if I were to + + align:start position:0% +what happens if I were to if I were to + + + align:start position:0% +what happens if I were to if I were to +take Theta from zero to Pi what would + + align:start position:0% +take Theta from zero to Pi what would + + + align:start position:0% +take Theta from zero to Pi what would +happen I would not only pick up the blue + + align:start position:0% +happen I would not only pick up the blue + + + align:start position:0% +happen I would not only pick up the blue +area but I'd pick up this pink stuff + + align:start position:0% +area but I'd pick up this pink stuff + + + align:start position:0% +area but I'd pick up this pink stuff +inside but I don't want the pink stuff I + + align:start position:0% +inside but I don't want the pink stuff I + + + align:start position:0% +inside but I don't want the pink stuff I +just want the blue stuff so what am I + + align:start position:0% +just want the blue stuff so what am I + + + align:start position:0% +just want the blue stuff so what am I +going to have to do to find the Blue + + align:start position:0% +going to have to do to find the Blue + + + align:start position:0% +going to have to do to find the Blue +Area just say from0 up to Pi I'm going + + align:start position:0% +Area just say from0 up to Pi I'm going + + + align:start position:0% +Area just say from0 up to Pi I'm going +to have to find the area from 0 to Pi + + align:start position:0% +to have to find the area from 0 to Pi + + + align:start position:0% +to have to find the area from 0 to Pi +and then I'm going to have to subtract + + align:start position:0% +and then I'm going to have to subtract + + + align:start position:0% +and then I'm going to have to subtract +off the area of this component okay but + + align:start position:0% +off the area of this component okay but + + + align:start position:0% +off the area of this component okay but +we know actually how to find the area of + + align:start position:0% +we know actually how to find the area of + + + align:start position:0% +we know actually how to find the area of +this component okay so hopefully this + + align:start position:0% +this component okay so hopefully this + + + align:start position:0% +this component okay so hopefully this +makes sense because let's think about + + align:start position:0% +makes sense because let's think about + + + align:start position:0% +makes sense because let's think about +when I'm finding area I'm going from the + + align:start position:0% +when I'm finding area I'm going from the + + + align:start position:0% +when I'm finding area I'm going from the +origin and I'm coming out and I have the + + align:start position:0% +origin and I'm coming out and I have the + + + align:start position:0% +origin and I'm coming out and I have the +radius out there so when I integrate + + align:start position:0% +radius out there so when I integrate + + + align:start position:0% +radius out there so when I integrate +this da from 0 to Pi for Theta I'm + + align:start position:0% +this da from 0 to Pi for Theta I'm + + + align:start position:0% +this da from 0 to Pi for Theta I'm +picking up pieces that come out little + + align:start position:0% +picking up pieces that come out little + + + align:start position:0% +picking up pieces that come out little +sectors that come out like this between + + align:start position:0% +sectors that come out like this between + + + align:start position:0% +sectors that come out like this between +pi 2 and Pi so I'm getting more area + + align:start position:0% +pi 2 and Pi so I'm getting more area + + + align:start position:0% +pi 2 and Pi so I'm getting more area +than I want if I just let Theta go + + align:start position:0% +than I want if I just let Theta go + + + align:start position:0% +than I want if I just let Theta go +between zero and Pi so I have to + + align:start position:0% +between zero and Pi so I have to + + + align:start position:0% +between zero and Pi so I have to +calculate all of it and then I have to + + align:start position:0% +calculate all of it and then I have to + + + align:start position:0% +calculate all of it and then I have to +take away the extra stuff okay so the + + align:start position:0% +take away the extra stuff okay so the + + + align:start position:0% +take away the extra stuff okay so the +blue area is actually the bigger area + + align:start position:0% +blue area is actually the bigger area + + + align:start position:0% +blue area is actually the bigger area +subtracting the smaller area and so how + + align:start position:0% +subtracting the smaller area and so how + + + align:start position:0% +subtracting the smaller area and so how +I'm going to write this if we come back + + align:start position:0% +I'm going to write this if we come back + + + align:start position:0% +I'm going to write this if we come back +over I'm just going to take two times + + align:start position:0% +over I'm just going to take two times + + + align:start position:0% +over I'm just going to take two times +this whole thing so I'm going to take + + align:start position:0% +this whole thing so I'm going to take + + + align:start position:0% +this whole thing so I'm going to take +two times this and I know I have to + + align:start position:0% +two times this and I know I have to + + + align:start position:0% +two times this and I know I have to +integrate it from 0 to + + align:start position:0% +integrate it from 0 to + + + align:start position:0% +integrate it from 0 to +Pi and I'm taking two times cuz it's + + align:start position:0% +Pi and I'm taking two times cuz it's + + + align:start position:0% +Pi and I'm taking two times cuz it's +symmetric remember and then I'm going to + + align:start position:0% +symmetric remember and then I'm going to + + + align:start position:0% +symmetric remember and then I'm going to +subtract off this one that's two times + + align:start position:0% +subtract off this one that's two times + + + align:start position:0% +subtract off this one that's two times +the thing from PI to 2 pi now you might + + align:start position:0% +the thing from PI to 2 pi now you might + + + align:start position:0% +the thing from PI to 2 pi now you might +say well Christine the pink stuff I'm + + align:start position:0% +say well Christine the pink stuff I'm + + + align:start position:0% +say well Christine the pink stuff I'm +interested in between zero and Pi is + + align:start position:0% +interested in between zero and Pi is + + + align:start position:0% +interested in between zero and Pi is +actually Theta between not pi and two Pi + + align:start position:0% +actually Theta between not pi and two Pi + + + align:start position:0% +actually Theta between not pi and two Pi +but 2 pi and 3 Pi but again there's all + + align:start position:0% +but 2 pi and 3 Pi but again there's all + + + align:start position:0% +but 2 pi and 3 Pi but again there's all +this symmetry in the problem so it + + align:start position:0% +this symmetry in the problem so it + + + align:start position:0% +this symmetry in the problem so it +doesn't really matter but if you're a + + align:start position:0% +doesn't really matter but if you're a + + + align:start position:0% +doesn't really matter but if you're a +stickler I guess I'll even write it this + + align:start position:0% +stickler I guess I'll even write it this + + + align:start position:0% +stickler I guess I'll even write it this +way just to make sure so I'll write it + + align:start position:0% +way just to make sure so I'll write it + + + align:start position:0% +way just to make sure so I'll write it +as 2 pi to 3 Pi so that everyone's very + + align:start position:0% +as 2 pi to 3 Pi so that everyone's very + + + align:start position:0% +as 2 pi to 3 Pi so that everyone's very +happy + + align:start position:0% + + + + align:start position:0% + +okay so again what did I what do we + + align:start position:0% +okay so again what did I what do we + + + align:start position:0% +okay so again what did I what do we +do these twos divide out so from 0 to Pi + + align:start position:0% +do these twos divide out so from 0 to Pi + + + align:start position:0% +do these twos divide out so from 0 to Pi +of R 2 D Theta that's going to give me + + align:start position:0% +of R 2 D Theta that's going to give me + + + align:start position:0% +of R 2 D Theta that's going to give me +the area of the blue plus the + + align:start position:0% +the area of the blue plus the + + + align:start position:0% +the area of the blue plus the +pink and then 2 pi to 3 Pi of 1 plus + + align:start position:0% +pink and then 2 pi to 3 Pi of 1 plus + + + align:start position:0% +pink and then 2 pi to 3 Pi of 1 plus +cosine Theta over 2^ 2 D Theta is going + + align:start position:0% +cosine Theta over 2^ 2 D Theta is going + + + align:start position:0% +cosine Theta over 2^ 2 D Theta is going +to give me the area of the pink so the + + align:start position:0% +to give me the area of the pink so the + + + align:start position:0% +to give me the area of the pink so the +the blue plus the pink is over here and + + align:start position:0% +the blue plus the pink is over here and + + + align:start position:0% +the blue plus the pink is over here and +then the pink is over here so when I + + align:start position:0% +then the pink is over here so when I + + + align:start position:0% +then the pink is over here so when I +subtract that off I just get the + + align:start position:0% +subtract that off I just get the + + + align:start position:0% +subtract that off I just get the +blue okay let me again just uh go back + + align:start position:0% +blue okay let me again just uh go back + + + align:start position:0% +blue okay let me again just uh go back +one more time and point out what we did + + align:start position:0% +one more time and point out what we did + + + align:start position:0% +one more time and point out what we did +at the very beginning to remind us what + + align:start position:0% +at the very beginning to remind us what + + + align:start position:0% +at the very beginning to remind us what +was + + align:start position:0% +was + + + align:start position:0% +was +happening um and then I will finish so + + align:start position:0% +happening um and then I will finish so + + + align:start position:0% +happening um and then I will finish so +let's come back over here so the idea + + align:start position:0% +let's come back over here so the idea + + + align:start position:0% +let's come back over here so the idea +was to graph this curve that was in R as + + align:start position:0% +was to graph this curve that was in R as + + + align:start position:0% +was to graph this curve that was in R as +a function of theta and I was supposed + + align:start position:0% +a function of theta and I was supposed + + + align:start position:0% +a function of theta and I was supposed +to understand what that looked like in + + align:start position:0% +to understand what that looked like in + + + align:start position:0% +to understand what that looked like in +the XY + + align:start position:0% +the XY + + + align:start position:0% +the XY +plane and so my trick was to take the + + align:start position:0% +plane and so my trick was to take the + + + align:start position:0% +plane and so my trick was to take the +the relationship between R and Theta and + + align:start position:0% +the relationship between R and Theta and + + + align:start position:0% +the relationship between R and Theta and +graph that explicitly in in an R Theta + + align:start position:0% +graph that explicitly in in an R Theta + + + align:start position:0% +graph that explicitly in in an R Theta +plane so I let Theta vary in the + + align:start position:0% +plane so I let Theta vary in the + + + align:start position:0% +plane so I let Theta vary in the +horizontal Direction and R vary in the + + align:start position:0% +horizontal Direction and R vary in the + + + align:start position:0% +horizontal Direction and R vary in the +vertical Direction and I can do that + + align:start position:0% +vertical Direction and I can do that + + + align:start position:0% +vertical Direction and I can do that +very easily and then translate that into + + align:start position:0% +very easily and then translate that into + + + align:start position:0% +very easily and then translate that into +the XY plane so my curve again went the + + align:start position:0% +the XY plane so my curve again went the + + + align:start position:0% +the XY plane so my curve again went the +big part the little part here little + + align:start position:0% +big part the little part here little + + + align:start position:0% +big part the little part here little +part here big part here that was the + + align:start position:0% +part here big part here that was the + + + align:start position:0% +part here big part here that was the +order so if you need uh if you need + + align:start position:0% +order so if you need uh if you need + + + align:start position:0% +order so if you need uh if you need +arrows on it this was the order + + align:start position:0% + + + + align:start position:0% + +and then once I had that the problem was + + align:start position:0% +and then once I had that the problem was + + + align:start position:0% +and then once I had that the problem was +about areas and there was a lot of + + align:start position:0% +about areas and there was a lot of + + + align:start position:0% +about areas and there was a lot of +symmetry in this problem um but the main + + align:start position:0% +symmetry in this problem um but the main + + + align:start position:0% +symmetry in this problem um but the main +point I wanted to show was just knowing + + align:start position:0% +point I wanted to show was just knowing + + + align:start position:0% +point I wanted to show was just knowing +where uh where your Theta starts and + + align:start position:0% +where uh where your Theta starts and + + + align:start position:0% +where uh where your Theta starts and +stops is not enough to determine an area + + align:start position:0% +stops is not enough to determine an area + + + align:start position:0% +stops is not enough to determine an area +of a region if that region is excluding + + align:start position:0% +of a region if that region is excluding + + + align:start position:0% +of a region if that region is excluding +some part that's that would be + + align:start position:0% +some part that's that would be + + + align:start position:0% +some part that's that would be +potentially counted twice so that was + + align:start position:0% +potentially counted twice so that was + + + align:start position:0% +potentially counted twice so that was +the reason I wanted you to calculate not + + align:start position:0% +the reason I wanted you to calculate not + + + align:start position:0% +the reason I wanted you to calculate not +just the pink area but also see that the + + align:start position:0% +just the pink area but also see that the + + + align:start position:0% +just the pink area but also see that the +blue is not from Theta Theta from 0 to + + align:start position:0% +blue is not from Theta Theta from 0 to + + + align:start position:0% +blue is not from Theta Theta from 0 to +Pi but you have to subtract off this + + align:start position:0% +Pi but you have to subtract off this + + + align:start position:0% +Pi but you have to subtract off this +extra stuff that you + + align:start position:0% +extra stuff that you + + + align:start position:0% +extra stuff that you +counted and I guess that is where I will + + align:start position:0% +counted and I guess that is where I will + + + align:start position:0% +counted and I guess that is where I will +stop \ No newline at end of file diff --git a/EQjwWn-WrdI.txt b/EQjwWn-WrdI.txt new file mode 100644 index 0000000000000000000000000000000000000000..da6825d33a0482c754e17e496e72e39390e97204 --- /dev/null +++ b/EQjwWn-WrdI.txt @@ -0,0 +1,15168 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a creative commons license + + align:start position:0% +a creative commons license + + + align:start position:0% +a creative commons license +your support will help mit + + align:start position:0% +your support will help mit + + + align:start position:0% +your support will help mit +opencourseware continue to offer high + + align:start position:0% +opencourseware continue to offer high + + + align:start position:0% +opencourseware continue to offer high +quality educational resources for free + + align:start position:0% +quality educational resources for free + + + align:start position:0% +quality educational resources for free +to make a donation or view additional + + align:start position:0% +to make a donation or view additional + + + align:start position:0% +to make a donation or view additional +materials from hundreds of mit courses + + align:start position:0% +materials from hundreds of mit courses + + + align:start position:0% +materials from hundreds of mit courses +visit mit open courseware at ocw.mit.edu + + align:start position:0% +visit mit open courseware at ocw.mit.edu + + + align:start position:0% +visit mit open courseware at ocw.mit.edu +okay so welcome back this is the second + + align:start position:0% +okay so welcome back this is the second + + + align:start position:0% +okay so welcome back this is the second +half of our + + align:start position:0% +half of our + + + align:start position:0% +half of our +two lectures on distributed algorithms + + align:start position:0% +two lectures on distributed algorithms + + + align:start position:0% +two lectures on distributed algorithms +this week + + align:start position:0% +this week + + + align:start position:0% +this week +to turn that on all right so + + align:start position:0% +to turn that on all right so + + + align:start position:0% +to turn that on all right so +i'll start with a quick review this week + + align:start position:0% +i'll start with a quick review this week + + + align:start position:0% +i'll start with a quick review this week +we're just looking at synchronous and + + align:start position:0% +we're just looking at synchronous and + + + align:start position:0% +we're just looking at synchronous and +asynchronous distributed algorithms not + + align:start position:0% +asynchronous distributed algorithms not + + + align:start position:0% +asynchronous distributed algorithms not +worrying about + + align:start position:0% +worrying about + + + align:start position:0% +worrying about +interesting stuff like failures last + + align:start position:0% +interesting stuff like failures last + + + align:start position:0% +interesting stuff like failures last +time we + + align:start position:0% +time we + + + align:start position:0% +time we +looked at leader election maximal + + align:start position:0% +looked at leader election maximal + + + align:start position:0% +looked at leader election maximal +independence set + + align:start position:0% +independence set + + + align:start position:0% +independence set +breadth first spanning trees and we + + align:start position:0% +breadth first spanning trees and we + + + align:start position:0% +breadth first spanning trees and we +started + + align:start position:0% +started + + + align:start position:0% +started +looking at shortest paths trees we'll + + align:start position:0% +looking at shortest paths trees we'll + + + align:start position:0% +looking at shortest paths trees we'll +finish that today and then we'll move on + + align:start position:0% +finish that today and then we'll move on + + + align:start position:0% +finish that today and then we'll move on +to the main topic for today which is + + align:start position:0% +to the main topic for today which is + + + align:start position:0% +to the main topic for today which is +asynchronous distributed algorithms + + align:start position:0% +asynchronous distributed algorithms + + + align:start position:0% +asynchronous distributed algorithms +where things start getting much more + + align:start position:0% +where things start getting much more + + + align:start position:0% +where things start getting much more +complicated because not everything is + + align:start position:0% +complicated because not everything is + + + align:start position:0% +complicated because not everything is +going on + + align:start position:0% +going on + + + align:start position:0% +going on +in synchronous rounds and we'll revisit + + align:start position:0% +in synchronous rounds and we'll revisit + + + align:start position:0% +in synchronous rounds and we'll revisit +the same two problems breadth first and + + align:start position:0% +the same two problems breadth first and + + + align:start position:0% +the same two problems breadth first and +shortest paths uh spanning trees + + align:start position:0% + + + + align:start position:0% + +okay so a quick review uh all of our + + align:start position:0% +okay so a quick review uh all of our + + + align:start position:0% +okay so a quick review uh all of our +um algorithms are + + align:start position:0% +um algorithms are + + + align:start position:0% +um algorithms are +using a model that's based on an + + align:start position:0% +using a model that's based on an + + + align:start position:0% +using a model that's based on an +undirected graph + + align:start position:0% + + + + align:start position:0% + +we using this notation gamma for the + + align:start position:0% +we using this notation gamma for the + + + align:start position:0% +we using this notation gamma for the +neighbors of a vertex + + align:start position:0% +neighbors of a vertex + + + align:start position:0% +neighbors of a vertex +talk about the degree of a vertex we + + align:start position:0% +talk about the degree of a vertex we + + + align:start position:0% +talk about the degree of a vertex we +have a process + + align:start position:0% +have a process + + + align:start position:0% +have a process +then associated with every vertex in the + + align:start position:0% +then associated with every vertex in the + + + align:start position:0% +then associated with every vertex in the +graph + + align:start position:0% +graph + + + align:start position:0% +graph +and we associate communication channels + + align:start position:0% +and we associate communication channels + + + align:start position:0% +and we associate communication channels +in both directions + + align:start position:0% +in both directions + + + align:start position:0% +in both directions +on every edge okay + + align:start position:0% +on every edge okay + + + align:start position:0% +on every edge okay +so last time we looked at synchronous + + align:start position:0% +so last time we looked at synchronous + + + align:start position:0% +so last time we looked at synchronous +distributed algorithms in the + + align:start position:0% +distributed algorithms in the + + + align:start position:0% +distributed algorithms in the +synchronous model + + align:start position:0% +synchronous model + + + align:start position:0% +synchronous model +we have the processes of the graph + + align:start position:0% +we have the processes of the graph + + + align:start position:0% +we have the processes of the graph +vertices they communicate using messages + + align:start position:0% +vertices they communicate using messages + + + align:start position:0% +vertices they communicate using messages +the processes have local ports that they + + align:start position:0% +the processes have local ports that they + + + align:start position:0% +the processes have local ports that they +know by some kind of local name + + align:start position:0% +know by some kind of local name + + + align:start position:0% +know by some kind of local name +and the ports connect to their + + align:start position:0% +and the ports connect to their + + + align:start position:0% +and the ports connect to their +communication channel + + align:start position:0% +communication channel + + + align:start position:0% +communication channel +the algorithm executes in synchronous + + align:start position:0% +the algorithm executes in synchronous + + + align:start position:0% +the algorithm executes in synchronous +rounds where in every round + + align:start position:0% +rounds where in every round + + + align:start position:0% +rounds where in every round +every process is going to decide what to + + align:start position:0% +every process is going to decide what to + + + align:start position:0% +every process is going to decide what to +send on all of its ports + + align:start position:0% +send on all of its ports + + + align:start position:0% +send on all of its ports +and the messages then get put into the + + align:start position:0% +and the messages then get put into the + + + align:start position:0% +and the messages then get put into the +channel delivered to the processes at + + align:start position:0% +channel delivered to the processes at + + + align:start position:0% +channel delivered to the processes at +the other end + + align:start position:0% +the other end + + + align:start position:0% +the other end +and everybody looks at all the messages + + align:start position:0% +and everybody looks at all the messages + + + align:start position:0% +and everybody looks at all the messages +they get at that round all at once + + align:start position:0% +they get at that round all at once + + + align:start position:0% +they get at that round all at once +and they determine a new state to + + align:start position:0% +and they determine a new state to + + + align:start position:0% +and they determine a new state to +compute a new state + + align:start position:0% +compute a new state + + + align:start position:0% +compute a new state +based on all of those arriving messages + + align:start position:0% +based on all of those arriving messages + + + align:start position:0% +based on all of those arriving messages +okay um + + align:start position:0% +okay um + + + align:start position:0% +okay um +so we started with leader election i + + align:start position:0% +so we started with leader election i + + + align:start position:0% +so we started with leader election i +won't repeat the problem definition but + + align:start position:0% +won't repeat the problem definition but + + + align:start position:0% +won't repeat the problem definition but +here's the results that we got last time + + align:start position:0% +here's the results that we got last time + + + align:start position:0% +here's the results that we got last time +uh we looked at a special case of a + + align:start position:0% +uh we looked at a special case of a + + + align:start position:0% +uh we looked at a special case of a +graph that's just a + + align:start position:0% +graph that's just a + + + align:start position:0% +graph that's just a +simple clique and if the processes + + align:start position:0% +simple clique and if the processes + + + align:start position:0% +simple clique and if the processes +don't have any uh distinguishing + + align:start position:0% +don't have any uh distinguishing + + + align:start position:0% +don't have any uh distinguishing +information like unique identifiers + + align:start position:0% +information like unique identifiers + + + align:start position:0% +information like unique identifiers +and they're deterministic then there's + + align:start position:0% +and they're deterministic then there's + + + align:start position:0% +and they're deterministic then there's +no way to break the symmetry and you can + + align:start position:0% +no way to break the symmetry and you can + + + align:start position:0% +no way to break the symmetry and you can +prove an impossibility result + + align:start position:0% +prove an impossibility result + + + align:start position:0% +prove an impossibility result +that says that you can't in a + + align:start position:0% +that says that you can't in a + + + align:start position:0% +that says that you can't in a +deterministic indistinguishable case you + + align:start position:0% +deterministic indistinguishable case you + + + align:start position:0% +deterministic indistinguishable case you +can't guarantee to elect a leader + + align:start position:0% +can't guarantee to elect a leader + + + align:start position:0% +can't guarantee to elect a leader +in this kind of a graph just as an aside + + align:start position:0% +in this kind of a graph just as an aside + + + align:start position:0% +in this kind of a graph just as an aside +i should say that distributed computing + + align:start position:0% +i should say that distributed computing + + + align:start position:0% +i should say that distributed computing +theory is + + align:start position:0% +theory is + + + align:start position:0% +theory is +just filled with impossibility results + + align:start position:0% +just filled with impossibility results + + + align:start position:0% +just filled with impossibility results +and they're all based on this limitation + + align:start position:0% +and they're all based on this limitation + + + align:start position:0% +and they're all based on this limitation +of distributed computing where + + align:start position:0% +of distributed computing where + + + align:start position:0% +of distributed computing where +each node only knows what's happening to + + align:start position:0% +each node only knows what's happening to + + + align:start position:0% +each node only knows what's happening to +itself and + + align:start position:0% +itself and + + + align:start position:0% +itself and +in its neighborhood nobody knows what's + + align:start position:0% +in its neighborhood nobody knows what's + + + align:start position:0% +in its neighborhood nobody knows what's +happening in the entire + + align:start position:0% +happening in the entire + + + align:start position:0% +happening in the entire +uh system so that's a very strong + + align:start position:0% +uh system so that's a very strong + + + align:start position:0% +uh system so that's a very strong +limitation + + align:start position:0% +limitation + + + align:start position:0% +limitation +and as you might expect that would make + + align:start position:0% +and as you might expect that would make + + + align:start position:0% +and as you might expect that would make +a lot of things impossible or difficult + + align:start position:0% +a lot of things impossible or difficult + + + align:start position:0% +a lot of things impossible or difficult +okay then we went on and got two + + align:start position:0% +okay then we went on and got two + + + align:start position:0% +okay then we went on and got two +positive results a theorem that + + align:start position:0% +positive results a theorem that + + + align:start position:0% +positive results a theorem that +um well an algorithm that is + + align:start position:0% +um well an algorithm that is + + + align:start position:0% +um well an algorithm that is +deterministic but the processes have + + align:start position:0% +deterministic but the processes have + + + align:start position:0% +deterministic but the processes have +unique identifiers + + align:start position:0% +unique identifiers + + + align:start position:0% +unique identifiers +and then you can elect a leader quickly + + align:start position:0% +and then you can elect a leader quickly + + + align:start position:0% +and then you can elect a leader quickly +or if you don't have unique identifiers + + align:start position:0% +or if you don't have unique identifiers + + + align:start position:0% +or if you don't have unique identifiers +but you have a + + align:start position:0% +but you have a + + + align:start position:0% +but you have a +probability so you can make random + + align:start position:0% +probability so you can make random + + + align:start position:0% +probability so you can make random +choices you can essentially + + align:start position:0% +choices you can essentially + + + align:start position:0% +choices you can essentially +choose an identifier and then it works + + align:start position:0% +choose an identifier and then it works + + + align:start position:0% +choose an identifier and then it works +almost as well + + align:start position:0% +almost as well + + + align:start position:0% +almost as well +with those identifiers okay then we + + align:start position:0% +with those identifiers okay then we + + + align:start position:0% +with those identifiers okay then we +looked at maximal independent set + + align:start position:0% +looked at maximal independent set + + + align:start position:0% +looked at maximal independent set +um remember what it means no two + + align:start position:0% +um remember what it means no two + + + align:start position:0% +um remember what it means no two +neighbors should both be in the set but + + align:start position:0% +neighbors should both be in the set but + + + align:start position:0% +neighbors should both be in the set but +you don't want to be able to + + align:start position:0% +you don't want to be able to + + + align:start position:0% +you don't want to be able to +add any more nodes while keeping these + + align:start position:0% +add any more nodes while keeping these + + + align:start position:0% +add any more nodes while keeping these +nodes independent in other words every + + align:start position:0% +nodes independent in other words every + + + align:start position:0% +nodes independent in other words every +node is either in the set or has a + + align:start position:0% +node is either in the set or has a + + + align:start position:0% +node is either in the set or has a +neighbor in the set + + align:start position:0% +neighbor in the set + + + align:start position:0% +neighbor in the set +okay and we gave this algorithm i'm just + + align:start position:0% +okay and we gave this algorithm i'm just + + + align:start position:0% +okay and we gave this algorithm i'm just +including it here for as a reminder + + align:start position:0% +including it here for as a reminder + + + align:start position:0% +including it here for as a reminder +luby's algorithm which basically + + align:start position:0% +luby's algorithm which basically + + + align:start position:0% +luby's algorithm which basically +goes through a number of phases in each + + align:start position:0% +goes through a number of phases in each + + + align:start position:0% +goes through a number of phases in each +phase some processes + + align:start position:0% +phase some processes + + + align:start position:0% +phase some processes +decide to join the mis and their + + align:start position:0% +decide to join the mis and their + + + align:start position:0% +decide to join the mis and their +neighbors + + align:start position:0% +neighbors + + + align:start position:0% +neighbors +decide not to join and you just repeat + + align:start position:0% +decide not to join and you just repeat + + + align:start position:0% +decide not to join and you just repeat +this you do this + + align:start position:0% +this you do this + + + align:start position:0% +this you do this +based on choosing random ideas again + + align:start position:0% +based on choosing random ideas again + + + align:start position:0% +based on choosing random ideas again +okay and we proved that the theorem + + align:start position:0% +okay and we proved that the theorem + + + align:start position:0% +okay and we proved that the theorem +correctly computes an mis and + + align:start position:0% +correctly computes an mis and + + + align:start position:0% +correctly computes an mis and +with a good probability all the nodes + + align:start position:0% +with a good probability all the nodes + + + align:start position:0% +with a good probability all the nodes +decide within only + + align:start position:0% +decide within only + + + align:start position:0% +decide within only +logarithm logarithmic phases n here is + + align:start position:0% +logarithm logarithmic phases n here is + + + align:start position:0% +logarithm logarithmic phases n here is +the number of nodes + + align:start position:0% +the number of nodes + + + align:start position:0% +the number of nodes +okay all right then we went on to + + align:start position:0% +okay all right then we went on to + + + align:start position:0% +okay all right then we went on to +breadth first spanning trees + + align:start position:0% +breadth first spanning trees + + + align:start position:0% +breadth first spanning trees +here we have now a graph that already + + align:start position:0% +here we have now a graph that already + + + align:start position:0% +here we have now a graph that already +has a leader it has a distinguished + + align:start position:0% +has a leader it has a distinguished + + + align:start position:0% +has a leader it has a distinguished +vertex + + align:start position:0% +vertex + + + align:start position:0% +vertex +and the process that's sitting there + + align:start position:0% +and the process that's sitting there + + + align:start position:0% +and the process that's sitting there +knows that it's the leader + + align:start position:0% +knows that it's the leader + + + align:start position:0% +knows that it's the leader +uh the processes now are going to + + align:start position:0% +uh the processes now are going to + + + align:start position:0% +uh the processes now are going to +produce a breadth-first spanning tree + + align:start position:0% +produce a breadth-first spanning tree + + + align:start position:0% +produce a breadth-first spanning tree +rooted + + align:start position:0% +rooted + + + align:start position:0% +rooted +at that vertex now for the rest of the + + align:start position:0% +at that vertex now for the rest of the + + + align:start position:0% +at that vertex now for the rest of the +time we'll assume unique identifiers but + + align:start position:0% +time we'll assume unique identifiers but + + + align:start position:0% +time we'll assume unique identifiers but +the processes don't know anything about + + align:start position:0% +the processes don't know anything about + + + align:start position:0% +the processes don't know anything about +the graph except the + + align:start position:0% +the graph except the + + + align:start position:0% +the graph except the +their own id and their neighbor's ids + + align:start position:0% +their own id and their neighbor's ids + + + align:start position:0% +their own id and their neighbor's ids +and we want the processes to eventually + + align:start position:0% +and we want the processes to eventually + + + align:start position:0% +and we want the processes to eventually +output + + align:start position:0% +output + + + align:start position:0% +output +the id of their parent and here's + + align:start position:0% +the id of their parent and here's + + + align:start position:0% +the id of their parent and here's +uh just to repeat uh the simple + + align:start position:0% +uh just to repeat uh the simple + + + align:start position:0% +uh just to repeat uh the simple +algorithm that we used + + align:start position:0% +algorithm that we used + + + align:start position:0% +algorithm that we used +so basically it's uh processes just mark + + align:start position:0% +so basically it's uh processes just mark + + + align:start position:0% +so basically it's uh processes just mark +themselves as they get included in the + + align:start position:0% +themselves as they get included in the + + + align:start position:0% +themselves as they get included in the +tree + + align:start position:0% +tree + + + align:start position:0% +tree +starts out with just the root being + + align:start position:0% +starts out with just the root being + + + align:start position:0% +starts out with just the root being +marked he sends a special search message + + align:start position:0% +marked he sends a special search message + + + align:start position:0% +marked he sends a special search message +out to his neighbors and as soon as they + + align:start position:0% +out to his neighbors and as soon as they + + + align:start position:0% +out to his neighbors and as soon as they +get it they get marked + + align:start position:0% +get it they get marked + + + align:start position:0% +get it they get marked +and pass it on so everybody gets marked + + align:start position:0% +and pass it on so everybody gets marked + + + align:start position:0% +and pass it on so everybody gets marked +in a number of rounds that corresponds + + align:start position:0% +in a number of rounds that corresponds + + + align:start position:0% +in a number of rounds that corresponds +to + + align:start position:0% +to + + + align:start position:0% +to +their depth in the their distance from + + align:start position:0% +their depth in the their distance from + + + align:start position:0% +their depth in the their distance from +the uh the root of the tree depth in the + + align:start position:0% +the uh the root of the tree depth in the + + + align:start position:0% +the uh the root of the tree depth in the +tree + + align:start position:0% +tree + + + align:start position:0% +tree +okay we talked about correctness in + + align:start position:0% +okay we talked about correctness in + + + align:start position:0% +okay we talked about correctness in +terms of invariance so what this + + align:start position:0% +terms of invariance so what this + + + align:start position:0% +terms of invariance so what this +algorithm guarantees is + + align:start position:0% +algorithm guarantees is + + + align:start position:0% +algorithm guarantees is +at the end of any number r of rounds + + align:start position:0% +at the end of any number r of rounds + + + align:start position:0% +at the end of any number r of rounds +exactly the processes at distance up to + + align:start position:0% +exactly the processes at distance up to + + + align:start position:0% +exactly the processes at distance up to +r + + align:start position:0% +r + + + align:start position:0% +r +are marked and the processes + + align:start position:0% +are marked and the processes + + + align:start position:0% +are marked and the processes +that are marked have their parents + + align:start position:0% +that are marked have their parents + + + align:start position:0% +that are marked have their parents +defined + + align:start position:0% +defined + + + align:start position:0% +defined +and if your parents defined it's correct + + align:start position:0% +and if your parents defined it's correct + + + align:start position:0% +and if your parents defined it's correct +it's the uid of a process + + align:start position:0% +it's the uid of a process + + + align:start position:0% +it's the uid of a process +that has distance d minus one from + + align:start position:0% +that has distance d minus one from + + + align:start position:0% +that has distance d minus one from +the root if you're at distance d your + + align:start position:0% +the root if you're at distance d your + + + align:start position:0% +the root if you're at distance d your +parent should be somebody who's + + align:start position:0% +parent should be somebody who's + + + align:start position:0% +parent should be somebody who's +correct has the correct distance d minus + + align:start position:0% +correct has the correct distance d minus + + + align:start position:0% +correct has the correct distance d minus +one + + align:start position:0% +one + + + align:start position:0% +one +okay we analyze the complexity time + + align:start position:0% +okay we analyze the complexity time + + + align:start position:0% +okay we analyze the complexity time +is counting the number of rounds and + + align:start position:0% +is counting the number of rounds and + + + align:start position:0% +is counting the number of rounds and +that's going to be at worst the diameter + + align:start position:0% +that's going to be at worst the diameter + + + align:start position:0% +that's going to be at worst the diameter +of the network it's really + + align:start position:0% +of the network it's really + + + align:start position:0% +of the network it's really +the distance from a particular vertex v0 + + align:start position:0% +the distance from a particular vertex v0 + + + align:start position:0% +the distance from a particular vertex v0 +the message complexity uh there's only + + align:start position:0% +the message complexity uh there's only + + + align:start position:0% +the message complexity uh there's only +one message sent in each direction on + + align:start position:0% +one message sent in each direction on + + + align:start position:0% +one message sent in each direction on +each edge so that's going to be only + + align:start position:0% +each edge so that's going to be only + + + align:start position:0% +each edge so that's going to be only +order of the number of edges and we + + align:start position:0% +order of the number of edges and we + + + align:start position:0% +order of the number of edges and we +talked about how you can get + + align:start position:0% +talked about how you can get + + + align:start position:0% +talked about how you can get +child pointers this just gives you + + align:start position:0% +child pointers this just gives you + + + align:start position:0% +child pointers this just gives you +parents but if you want to also find out + + align:start position:0% +parents but if you want to also find out + + + align:start position:0% +parents but if you want to also find out +your children then every + + align:start position:0% +your children then every + + + align:start position:0% +your children then every +search message should get a response + + align:start position:0% +search message should get a response + + + align:start position:0% +search message should get a response +either saying you're my parent or you're + + align:start position:0% +either saying you're my parent or you're + + + align:start position:0% +either saying you're my parent or you're +not my parent + + align:start position:0% +not my parent + + + align:start position:0% +not my parent +and we can do uh termination using + + align:start position:0% +and we can do uh termination using + + + align:start position:0% +and we can do uh termination using +converge cast and + + align:start position:0% +converge cast and + + + align:start position:0% +converge cast and +there's some applications we talked + + align:start position:0% +there's some applications we talked + + + align:start position:0% +there's some applications we talked +about as well + + align:start position:0% +about as well + + + align:start position:0% +about as well +okay all right and then at the end of + + align:start position:0% +okay all right and then at the end of + + + align:start position:0% +okay all right and then at the end of +the hour we + + align:start position:0% +the hour we + + + align:start position:0% +the hour we +started talking about a generalization + + align:start position:0% +started talking about a generalization + + + align:start position:0% +started talking about a generalization +of breadth first spanning trees which + + align:start position:0% +of breadth first spanning trees which + + + align:start position:0% +of breadth first spanning trees which +adds weights + + align:start position:0% +adds weights + + + align:start position:0% +adds weights +so you have shortest paths trees okay so + + align:start position:0% +so you have shortest paths trees okay so + + + align:start position:0% +so you have shortest paths trees okay so +now you have weights on the edges + + align:start position:0% +now you have weights on the edges + + + align:start position:0% +now you have weights on the edges +processes still have unique identifiers + + align:start position:0% + + + + align:start position:0% + +they don't know anything about the graph + + align:start position:0% +they don't know anything about the graph + + + align:start position:0% +they don't know anything about the graph +except their immediate neighborhood + + align:start position:0% +except their immediate neighborhood + + + align:start position:0% +except their immediate neighborhood +information and they have to produce a + + align:start position:0% +information and they have to produce a + + + align:start position:0% +information and they have to produce a +shortest path spanning tree + + align:start position:0% +shortest path spanning tree + + + align:start position:0% +shortest path spanning tree +rooted at a vertex v zero + + align:start position:0% +rooted at a vertex v zero + + + align:start position:0% +rooted at a vertex v zero +okay so you know what a spanning tree is + + align:start position:0% +okay so you know what a spanning tree is + + + align:start position:0% +okay so you know what a spanning tree is +and shortest paths are in terms of the + + align:start position:0% +and shortest paths are in terms of the + + + align:start position:0% +and shortest paths are in terms of the +total weight of the path + + align:start position:0% +total weight of the path + + + align:start position:0% +total weight of the path +so now we want each node each process to + + align:start position:0% +so now we want each node each process to + + + align:start position:0% +so now we want each node each process to +output + + align:start position:0% +output + + + align:start position:0% +output +its parent in the shortest path and also + + align:start position:0% +its parent in the shortest path and also + + + align:start position:0% +its parent in the shortest path and also +the distance from + + align:start position:0% +the distance from + + + align:start position:0% +the distance from +the original vertex v0 + + align:start position:0% + + + + align:start position:0% + +okay so at the end of the hour we looked + + align:start position:0% +okay so at the end of the hour we looked + + + align:start position:0% +okay so at the end of the hour we looked +at + + align:start position:0% +at + + + align:start position:0% +at +a version of bellman ford which you've + + align:start position:0% +a version of bellman ford which you've + + + align:start position:0% +a version of bellman ford which you've +already seen + + align:start position:0% +already seen + + + align:start position:0% +already seen +for sequential algorithm as a sequential + + align:start position:0% +for sequential algorithm as a sequential + + + align:start position:0% +for sequential algorithm as a sequential +algorithm + + align:start position:0% +algorithm + + + align:start position:0% +algorithm +but as a distributed algorithm everybody + + align:start position:0% +but as a distributed algorithm everybody + + + align:start position:0% +but as a distributed algorithm everybody +keeps track of their best guess + + align:start position:0% +keeps track of their best guess + + + align:start position:0% +keeps track of their best guess +their best current guess of the distance + + align:start position:0% +their best current guess of the distance + + + align:start position:0% +their best current guess of the distance +from + + align:start position:0% +from + + + align:start position:0% +from +the initial vertex and they keep track + + align:start position:0% +the initial vertex and they keep track + + + align:start position:0% +the initial vertex and they keep track +of their + + align:start position:0% +of their + + + align:start position:0% +of their +parent on some path that gave it + + align:start position:0% +parent on some path that gave it + + + align:start position:0% +parent on some path that gave it +this distance estimate and they keep + + align:start position:0% +this distance estimate and they keep + + + align:start position:0% +this distance estimate and they keep +their unique identifier + + align:start position:0% +their unique identifier + + + align:start position:0% +their unique identifier +okay so the complete algorithm now is + + align:start position:0% +okay so the complete algorithm now is + + + align:start position:0% +okay so the complete algorithm now is +everybody's going to keep sending their + + align:start position:0% +everybody's going to keep sending their + + + align:start position:0% +everybody's going to keep sending their +distance around i mean we could optimize + + align:start position:0% +distance around i mean we could optimize + + + align:start position:0% +distance around i mean we could optimize +that but + + align:start position:0% +that but + + + align:start position:0% +that but +this is simple so at every round + + align:start position:0% +this is simple so at every round + + + align:start position:0% +this is simple so at every round +everybody sends + + align:start position:0% +everybody sends + + + align:start position:0% +everybody sends +their current distance estimate to all + + align:start position:0% +their current distance estimate to all + + + align:start position:0% +their current distance estimate to all +their neighbors they all they collect + + align:start position:0% +their neighbors they all they collect + + + align:start position:0% +their neighbors they all they collect +the distance estimates from all their + + align:start position:0% +the distance estimates from all their + + + align:start position:0% +the distance estimates from all their +neighbors + + align:start position:0% +neighbors + + + align:start position:0% +neighbors +and then they do a relaxation step if + + align:start position:0% +and then they do a relaxation step if + + + align:start position:0% +and then they do a relaxation step if +they get anything that's better than + + align:start position:0% +they get anything that's better than + + + align:start position:0% +they get anything that's better than +what they had before + + align:start position:0% +what they had before + + + align:start position:0% +what they had before +they look at the best new estimate they + + align:start position:0% +they look at the best new estimate they + + + align:start position:0% +they look at the best new estimate they +could get so they take the minimum of + + align:start position:0% +could get so they take the minimum of + + + align:start position:0% +could get so they take the minimum of +their old estimate + + align:start position:0% + + + + align:start position:0% + +stop shaking good and the minimum + + align:start position:0% +stop shaking good and the minimum + + + align:start position:0% +stop shaking good and the minimum +of uh all of the uh estimates they would + + align:start position:0% +of uh all of the uh estimates they would + + + align:start position:0% +of uh all of the uh estimates they would +get + + align:start position:0% +get + + + align:start position:0% +get +by looking at the incoming information + + align:start position:0% +by looking at the incoming information + + + align:start position:0% +by looking at the incoming information +plus adding the weight + + align:start position:0% +plus adding the weight + + + align:start position:0% +plus adding the weight +of the edge between the sender + + align:start position:0% +of the edge between the sender + + + align:start position:0% +of the edge between the sender +and and the note itself okay so this way + + align:start position:0% +and and the note itself okay so this way + + + align:start position:0% +and and the note itself okay so this way +you get a better + + align:start position:0% +you get a better + + + align:start position:0% +you get a better +you may get a better estimate and if you + + align:start position:0% +you may get a better estimate and if you + + + align:start position:0% +you may get a better estimate and if you +do you you would reset your parent + + align:start position:0% +do you you would reset your parent + + + align:start position:0% +do you you would reset your parent +to be the sender of this + + align:start position:0% +to be the sender of this + + + align:start position:0% +to be the sender of this +improved information and again you can + + align:start position:0% +improved information and again you can + + + align:start position:0% +improved information and again you can +pick + + align:start position:0% +pick + + + align:start position:0% +pick +if there's a tie you can pick um + + align:start position:0% +if there's a tie you can pick um + + + align:start position:0% +if there's a tie you can pick um +any of the the nodes that sends the the + + align:start position:0% +any of the the nodes that sends the the + + + align:start position:0% +any of the the nodes that sends the the +information leading to the the best + + align:start position:0% +information leading to the the best + + + align:start position:0% +information leading to the the best +new guess you can set your parent to any + + align:start position:0% +new guess you can set your parent to any + + + align:start position:0% +new guess you can set your parent to any +of those + + align:start position:0% +of those + + + align:start position:0% +of those +okay and then this just repeats + + align:start position:0% +okay and then this just repeats + + + align:start position:0% +okay and then this just repeats +okay so at the very end of the hour we + + align:start position:0% +okay so at the very end of the hour we + + + align:start position:0% +okay so at the very end of the hour we +we showed a + + align:start position:0% +we showed a + + + align:start position:0% +we showed a +an animation which i'm not going to + + align:start position:0% +an animation which i'm not going to + + + align:start position:0% +an animation which i'm not going to +repeat now which basically shows how you + + align:start position:0% +repeat now which basically shows how you + + + align:start position:0% +repeat now which basically shows how you +can get lots of + + align:start position:0% +can get lots of + + + align:start position:0% +can get lots of +corrections there you can have + + align:start position:0% +corrections there you can have + + + align:start position:0% +corrections there you can have +many pads that are set up that look good + + align:start position:0% +many pads that are set up that look good + + + align:start position:0% +many pads that are set up that look good +after just one round but then they get + + align:start position:0% +after just one round but then they get + + + align:start position:0% +after just one round but then they get +corrected + + align:start position:0% +corrected + + + align:start position:0% +corrected +as the rounds go on so you get much + + align:start position:0% +as the rounds go on so you get much + + + align:start position:0% +as the rounds go on so you get much +lower weight paths by having a + + align:start position:0% +lower weight paths by having a + + + align:start position:0% +lower weight paths by having a +roundabout + + align:start position:0% +roundabout + + + align:start position:0% +roundabout +multi-hop path to a node you can get a + + align:start position:0% +multi-hop path to a node you can get a + + + align:start position:0% +multi-hop path to a node you can get a +better total cost + + align:start position:0% +better total cost + + + align:start position:0% +better total cost +okay so here's where we got to last time + + align:start position:0% +okay so here's where we got to last time + + + align:start position:0% +okay so here's where we got to last time +so now why does this work well what we + + align:start position:0% +so now why does this work well what we + + + align:start position:0% +so now why does this work well what we +need is eventually + + align:start position:0% +need is eventually + + + align:start position:0% +need is eventually +every process should get the correct + + align:start position:0% +every process should get the correct + + + align:start position:0% +every process should get the correct +distance + + align:start position:0% +distance + + + align:start position:0% +distance +and the parent should be its predecessor + + align:start position:0% +and the parent should be its predecessor + + + align:start position:0% +and the parent should be its predecessor +on some shortest path + + align:start position:0% +on some shortest path + + + align:start position:0% +on some shortest path +in order to prove that okay so you + + align:start position:0% +in order to prove that okay so you + + + align:start position:0% +in order to prove that okay so you +always look for an invariant + + align:start position:0% +always look for an invariant + + + align:start position:0% +always look for an invariant +something that's true at intermediate + + align:start position:0% +something that's true at intermediate + + + align:start position:0% +something that's true at intermediate +steps of the algorithm that you can show + + align:start position:0% +steps of the algorithm that you can show + + + align:start position:0% +steps of the algorithm that you can show +by induction will hold and that will + + align:start position:0% +by induction will hold and that will + + + align:start position:0% +by induction will hold and that will +imply the result that you want at the + + align:start position:0% +imply the result that you want at the + + + align:start position:0% +imply the result that you want at the +end + + align:start position:0% +end + + + align:start position:0% +end +so here um what's the key invariant at + + align:start position:0% +so here um what's the key invariant at + + + align:start position:0% +so here um what's the key invariant at +the end + + align:start position:0% +the end + + + align:start position:0% +the end +of some number r of rounds + + align:start position:0% +of some number r of rounds + + + align:start position:0% +of some number r of rounds +what do processes have + + align:start position:0% + + + + align:start position:0% + +okay after r rounds have passed in this + + align:start position:0% +okay after r rounds have passed in this + + + align:start position:0% +okay after r rounds have passed in this +kind of algorithm + + align:start position:0% +kind of algorithm + + + align:start position:0% +kind of algorithm +what what do the estimates look like + + align:start position:0% + + + + align:start position:0% + +well after one round everybody's got + + align:start position:0% +well after one round everybody's got + + + align:start position:0% +well after one round everybody's got +their best + + align:start position:0% +their best + + + align:start position:0% +their best +estimate uh that could happen on a + + align:start position:0% +estimate uh that could happen on a + + + align:start position:0% +estimate uh that could happen on a +single + + align:start position:0% +single + + + align:start position:0% +single +that could result from a single hot path + + align:start position:0% +that could result from a single hot path + + + align:start position:0% +that could result from a single hot path +from v zero + + align:start position:0% +from v zero + + + align:start position:0% +from v zero +after two rounds you also get the best + + align:start position:0% +after two rounds you also get the best + + + align:start position:0% +after two rounds you also get the best +guesses from two hot pads + + align:start position:0% +guesses from two hot pads + + + align:start position:0% +guesses from two hot pads +and after r rounds in general um you + + align:start position:0% +and after r rounds in general um you + + + align:start position:0% +and after r rounds in general um you +have + + align:start position:0% +have + + + align:start position:0% +have +your distance and parent corresponding + + align:start position:0% +your distance and parent corresponding + + + align:start position:0% +your distance and parent corresponding +to a shortest path + + align:start position:0% +to a shortest path + + + align:start position:0% +to a shortest path +chosen from among those that have it + + align:start position:0% +chosen from among those that have it + + + align:start position:0% +chosen from among those that have it +most are hops + + align:start position:0% +most are hops + + + align:start position:0% +most are hops +yes that makes sense + + align:start position:0% + + + + align:start position:0% + +no yeah okay all right and + + align:start position:0% +no yeah okay all right and + + + align:start position:0% +no yeah okay all right and +if there is no path of our hops or fewer + + align:start position:0% +if there is no path of our hops or fewer + + + align:start position:0% +if there is no path of our hops or fewer +to get to a node they're still going to + + align:start position:0% +to get to a node they're still going to + + + align:start position:0% +to get to a node they're still going to +have their distance estimate be + + align:start position:0% +have their distance estimate be + + + align:start position:0% +have their distance estimate be +infinity after r rounds + + align:start position:0% +infinity after r rounds + + + align:start position:0% +infinity after r rounds +so this is not a complete proof but it's + + align:start position:0% +so this is not a complete proof but it's + + + align:start position:0% +so this is not a complete proof but it's +the key invariant that makes this work + + align:start position:0% +the key invariant that makes this work + + + align:start position:0% +the key invariant that makes this work +so you can see that after + + align:start position:0% +so you can see that after + + + align:start position:0% +so you can see that after +enough rounds corresponding to the + + align:start position:0% +enough rounds corresponding to the + + + align:start position:0% +enough rounds corresponding to the +number of nodes for example + + align:start position:0% +number of nodes for example + + + align:start position:0% +number of nodes for example +everybody will have the correct shortest + + align:start position:0% +everybody will have the correct shortest + + + align:start position:0% +everybody will have the correct shortest +path + + align:start position:0% +path + + + align:start position:0% +path +of any length okay + + align:start position:0% +of any length okay + + + align:start position:0% +of any length okay +so the number of rounds until every + + align:start position:0% +so the number of rounds until every + + + align:start position:0% +so the number of rounds until every +estimate stabilized all the estimates + + align:start position:0% +estimate stabilized all the estimates + + + align:start position:0% +estimate stabilized all the estimates +stabilize + + align:start position:0% + + + + align:start position:0% + +it's going to be n minus 1 right + + align:start position:0% +it's going to be n minus 1 right + + + align:start position:0% +it's going to be n minus 1 right +because the longest simple path + + align:start position:0% +because the longest simple path + + + align:start position:0% +because the longest simple path +to any node is going to be n minus 1 if + + align:start position:0% +to any node is going to be n minus 1 if + + + align:start position:0% +to any node is going to be n minus 1 if +it goes through all the nodes + + align:start position:0% +it goes through all the nodes + + + align:start position:0% +it goes through all the nodes +of the network before reaching it makes + + align:start position:0% +of the network before reaching it makes + + + align:start position:0% +of the network before reaching it makes +sense + + align:start position:0% +sense + + + align:start position:0% +sense +so if you want to make sure you have the + + align:start position:0% +so if you want to make sure you have the + + + align:start position:0% +so if you want to make sure you have the +best estimate you have to wait n + + align:start position:0% +best estimate you have to wait n + + + align:start position:0% +best estimate you have to wait n +minus 1 rounds to make sure the + + align:start position:0% +minus 1 rounds to make sure the + + + align:start position:0% +minus 1 rounds to make sure the +information has reached you + + align:start position:0% +information has reached you + + + align:start position:0% +information has reached you +the message complexity well that since + + align:start position:0% +the message complexity well that since + + + align:start position:0% +the message complexity well that since +there's all these repeated estimates + + align:start position:0% +there's all these repeated estimates + + + align:start position:0% +there's all these repeated estimates +it's no longer just + + align:start position:0% +it's no longer just + + + align:start position:0% +it's no longer just +proportional to the number of edges but + + align:start position:0% +proportional to the number of edges but + + + align:start position:0% +proportional to the number of edges but +you have to take into account that there + + align:start position:0% +you have to take into account that there + + + align:start position:0% +you have to take into account that there +can be many new estimates sent + + align:start position:0% +can be many new estimates sent + + + align:start position:0% +can be many new estimates sent +on on each edge in fact the way i've + + align:start position:0% +on on each edge in fact the way i've + + + align:start position:0% +on on each edge in fact the way i've +written this + + align:start position:0% +written this + + + align:start position:0% +written this +you just keep sending your distance at + + align:start position:0% +you just keep sending your distance at + + + align:start position:0% +you just keep sending your distance at +every round so it's going to be + + align:start position:0% + + + + align:start position:0% + +the number of edges times the number of + + align:start position:0% +the number of edges times the number of + + + align:start position:0% +the number of edges times the number of +rounds so + + align:start position:0% +rounds so + + + align:start position:0% +rounds so +you know you can do somewhat better than + + align:start position:0% +you know you can do somewhat better than + + + align:start position:0% +you know you can do somewhat better than +this but it's worse than + + align:start position:0% +this but it's worse than + + + align:start position:0% +this but it's worse than +than just the simple bfs case + + align:start position:0% +than just the simple bfs case + + + align:start position:0% +than just the simple bfs case +okay so this is more expensive because + + align:start position:0% +okay so this is more expensive because + + + align:start position:0% +okay so this is more expensive because +bfs just had + + align:start position:0% +bfs just had + + + align:start position:0% +bfs just had +diameter rounds and this now has n + + align:start position:0% +diameter rounds and this now has n + + + align:start position:0% +diameter rounds and this now has n +or n minus one rounds and bfs just had + + align:start position:0% +or n minus one rounds and bfs just had + + + align:start position:0% +or n minus one rounds and bfs just had +one message + + align:start position:0% +one message + + + align:start position:0% +one message +ever sent on each edge and now we have + + align:start position:0% +ever sent on each edge and now we have + + + align:start position:0% +ever sent on each edge and now we have +to send many + + align:start position:0% +to send many + + + align:start position:0% +to send many +comments questions + + align:start position:0% + + + + align:start position:0% + +okay okay so is it clear that the time + + align:start position:0% +okay okay so is it clear that the time + + + align:start position:0% +okay okay so is it clear that the time +bound really does depend on + + align:start position:0% +bound really does depend on + + + align:start position:0% +bound really does depend on +n and not on the diameter + + align:start position:0% + + + + align:start position:0% + +okay for breadth-first search it was + + align:start position:0% +okay for breadth-first search it was + + + align:start position:0% +okay for breadth-first search it was +enough just to + + align:start position:0% +enough just to + + + align:start position:0% +enough just to +um have enough rounds to correspond to + + align:start position:0% +um have enough rounds to correspond to + + + align:start position:0% +um have enough rounds to correspond to +the + + align:start position:0% +the + + + align:start position:0% +the +actual + + align:start position:0% + + + + align:start position:0% + +distance and hops to each node but now + + align:start position:0% +distance and hops to each node but now + + + align:start position:0% +distance and hops to each node but now +you need enough rounds to take care of + + align:start position:0% +you need enough rounds to take care of + + + align:start position:0% +you need enough rounds to take care of +these indirect pads that might go + + align:start position:0% +these indirect pads that might go + + + align:start position:0% +these indirect pads that might go +through + + align:start position:0% +through + + + align:start position:0% +through +many nodes but still end up with a + + align:start position:0% +many nodes but still end up with a + + + align:start position:0% +many nodes but still end up with a +shorter + + align:start position:0% +shorter + + + align:start position:0% +shorter +with a smaller total weight okay so is + + align:start position:0% +with a smaller total weight okay so is + + + align:start position:0% +with a smaller total weight okay so is +it clear to everybody why the bound + + align:start position:0% +it clear to everybody why the bound + + + align:start position:0% +it clear to everybody why the bound +depends on + + align:start position:0% +depends on + + + align:start position:0% +depends on +n actually the animation that i had last + + align:start position:0% +n actually the animation that i had last + + + align:start position:0% +n actually the animation that i had last +time + + align:start position:0% +time + + + align:start position:0% +time +showed uh how there were lots of + + align:start position:0% +showed uh how there were lots of + + + align:start position:0% +showed uh how there were lots of +corrections and and + + align:start position:0% +corrections and and + + + align:start position:0% +corrections and and +you had enough you had rounds that + + align:start position:0% +you had enough you had rounds that + + + align:start position:0% +you had enough you had rounds that +depended on the total number of nodes + + align:start position:0% +depended on the total number of nodes + + + align:start position:0% +depended on the total number of nodes +yes + + align:start position:0% + + + + align:start position:0% + +yeah um but like could you like keep + + align:start position:0% +yeah um but like could you like keep + + + align:start position:0% +yeah um but like could you like keep +track of like + + align:start position:0% +track of like + + + align:start position:0% +track of like +uh each round if if the values if any of + + align:start position:0% +uh each round if if the values if any of + + + align:start position:0% +uh each round if if the values if any of +the guys didn't + + align:start position:0% +the guys didn't + + + align:start position:0% +the guys didn't +relax so like if you if everything stops + + align:start position:0% +relax so like if you if everything stops + + + align:start position:0% +relax so like if you if everything stops +changing after less than n rounds + + align:start position:0% +changing after less than n rounds + + + align:start position:0% +changing after less than n rounds +you might not have to okay so you're + + align:start position:0% +you might not have to okay so you're + + + align:start position:0% +you might not have to okay so you're +asking about termination + + align:start position:0% +asking about termination + + + align:start position:0% +asking about termination +ah okay well so that's probably the next + + align:start position:0% +ah okay well so that's probably the next + + + align:start position:0% +ah okay well so that's probably the next +slide + + align:start position:0% +slide + + + align:start position:0% +slide +first let's deal with the child pointers + + align:start position:0% +first let's deal with the child pointers + + + align:start position:0% +first let's deal with the child pointers +and we'll come back to termination okay + + align:start position:0% +and we'll come back to termination okay + + + align:start position:0% +and we'll come back to termination okay +so first this just gives you your + + align:start position:0% +so first this just gives you your + + + align:start position:0% +so first this just gives you your +parents if you want your children you + + align:start position:0% +parents if you want your children you + + + align:start position:0% +parents if you want your children you +can + + align:start position:0% +can + + + align:start position:0% +can +do the same thing that we did last time + + align:start position:0% +do the same thing that we did last time + + + align:start position:0% +do the same thing that we did last time +when a process gets a message + + align:start position:0% +when a process gets a message + + + align:start position:0% +when a process gets a message +and the message doesn't make the sender + + align:start position:0% +and the message doesn't make the sender + + + align:start position:0% +and the message doesn't make the sender +its parent + + align:start position:0% +its parent + + + align:start position:0% +its parent +this is not giving it an improved + + align:start position:0% +this is not giving it an improved + + + align:start position:0% +this is not giving it an improved +distance + + align:start position:0% +distance + + + align:start position:0% +distance +then the node can just respond + + align:start position:0% +then the node can just respond + + + align:start position:0% +then the node can just respond +non-parent + + align:start position:0% +non-parent + + + align:start position:0% +non-parent +but if a process receives a message that + + align:start position:0% +but if a process receives a message that + + + align:start position:0% +but if a process receives a message that +does improve the distance it says + + align:start position:0% +does improve the distance it says + + + align:start position:0% +does improve the distance it says +ah okay you are my parent but + + align:start position:0% +ah okay you are my parent but + + + align:start position:0% +ah okay you are my parent but +it might have also told another node it + + align:start position:0% +it might have also told another node it + + + align:start position:0% +it might have also told another node it +might have another parent another node + + align:start position:0% +might have another parent another node + + + align:start position:0% +might have another parent another node +that previously it thought was + + align:start position:0% +that previously it thought was + + + align:start position:0% +that previously it thought was +his parent so it has to do more work in + + align:start position:0% +his parent so it has to do more work in + + + align:start position:0% +his parent so it has to do more work in +this case to correct the erroneous + + align:start position:0% +this case to correct the erroneous + + + align:start position:0% +this case to correct the erroneous +parent information + + align:start position:0% +parent information + + + align:start position:0% +parent information +so it has to send its previous + + align:start position:0% +so it has to send its previous + + + align:start position:0% +so it has to send its previous +parent a non-parent message to correct + + align:start position:0% +parent a non-parent message to correct + + + align:start position:0% +parent a non-parent message to correct +the previous parent message + + align:start position:0% +the previous parent message + + + align:start position:0% +the previous parent message +okay so things are getting a little bit + + align:start position:0% +okay so things are getting a little bit + + + align:start position:0% +okay so things are getting a little bit +trickier here + + align:start position:0% +trickier here + + + align:start position:0% +trickier here +on the other end if somebody is keeping + + align:start position:0% +on the other end if somebody is keeping + + + align:start position:0% +on the other end if somebody is keeping +track of its children it has to + + align:start position:0% +track of its children it has to + + + align:start position:0% +track of its children it has to +make adjustments to is because things + + align:start position:0% +make adjustments to is because things + + + align:start position:0% +make adjustments to is because things +can change during the algorithm + + align:start position:0% +can change during the algorithm + + + align:start position:0% +can change during the algorithm +okay so let's say a process keeps track + + align:start position:0% +okay so let's say a process keeps track + + + align:start position:0% +okay so let's say a process keeps track +of its children in some set + + align:start position:0% +of its children in some set + + + align:start position:0% +of its children in some set +it has a set children okay if it gets a + + align:start position:0% +it has a set children okay if it gets a + + + align:start position:0% +it has a set children okay if it gets a +non-parent message from a child + + align:start position:0% +non-parent message from a child + + + align:start position:0% +non-parent message from a child +even if that child that child might be + + align:start position:0% +even if that child that child might be + + + align:start position:0% +even if that child that child might be +or from a neighbor + + align:start position:0% +or from a neighbor + + + align:start position:0% +or from a neighbor +that neighbor might be and it set + + align:start position:0% +that neighbor might be and it set + + + align:start position:0% +that neighbor might be and it set +children and this could be a correction + + align:start position:0% +children and this could be a correction + + + align:start position:0% +children and this could be a correction +then the process has to take that + + align:start position:0% +then the process has to take that + + + align:start position:0% +then the process has to take that +neighbor out of the set of children + + align:start position:0% +neighbor out of the set of children + + + align:start position:0% +neighbor out of the set of children +okay and suppose the process + + align:start position:0% +okay and suppose the process + + + align:start position:0% +okay and suppose the process +improves its own distance well now it's + + align:start position:0% +improves its own distance well now it's + + + align:start position:0% +improves its own distance well now it's +kind of starting over + + align:start position:0% +kind of starting over + + + align:start position:0% +kind of starting over +it's going to send that distance to its + + align:start position:0% +it's going to send that distance to its + + + align:start position:0% +it's going to send that distance to its +all of its neighbors again + + align:start position:0% +all of its neighbors again + + + align:start position:0% +all of its neighbors again +and collect new information about + + align:start position:0% +and collect new information about + + + align:start position:0% +and collect new information about +whether they're children or not so + + align:start position:0% +whether they're children or not so + + + align:start position:0% +whether they're children or not so +the simple thing to do here is just + + align:start position:0% +the simple thing to do here is just + + + align:start position:0% +the simple thing to do here is just +empty + + align:start position:0% +empty + + + align:start position:0% +empty +zero out your children set and start + + align:start position:0% +zero out your children set and start + + + align:start position:0% +zero out your children set and start +over now you send + + align:start position:0% +over now you send + + + align:start position:0% +over now you send +your your new messages to your neighbors + + align:start position:0% +your your new messages to your neighbors + + + align:start position:0% +your your new messages to your neighbors +and wait for them to respond again + + align:start position:0% +and wait for them to respond again + + + align:start position:0% +and wait for them to respond again +so there's tricky bookkeeping to do to + + align:start position:0% +so there's tricky bookkeeping to do to + + + align:start position:0% +so there's tricky bookkeeping to do to +handle corrections + + align:start position:0% +handle corrections + + + align:start position:0% +handle corrections +as the structure of this tree changes so + + align:start position:0% +as the structure of this tree changes so + + + align:start position:0% +as the structure of this tree changes so +getting child pointers is a little more + + align:start position:0% +getting child pointers is a little more + + + align:start position:0% +getting child pointers is a little more +complicated than before + + align:start position:0% +complicated than before + + + align:start position:0% +complicated than before +make sense okay all right so now back to + + align:start position:0% +make sense okay all right so now back to + + + align:start position:0% +make sense okay all right so now back to +your question + + align:start position:0% +your question + + + align:start position:0% +your question +uh termination um + + align:start position:0% +uh termination um + + + align:start position:0% +uh termination um +so how do all the processes know when + + align:start position:0% +so how do all the processes know when + + + align:start position:0% +so how do all the processes know when +the tree + + align:start position:0% +the tree + + + align:start position:0% +the tree +is complete in fact we have a worse + + align:start position:0% +is complete in fact we have a worse + + + align:start position:0% +is complete in fact we have a worse +problem we this problem we hit for + + align:start position:0% +problem we this problem we hit for + + + align:start position:0% +problem we this problem we hit for +a breath first search but we have an + + align:start position:0% +a breath first search but we have an + + + align:start position:0% +a breath first search but we have an +even worse problem now what is that + + align:start position:0% + + + + align:start position:0% + +yeah yeah + + align:start position:0% +yeah yeah + + + align:start position:0% +yeah yeah +before we had each individual node once + + align:start position:0% +before we had each individual node once + + + align:start position:0% +before we had each individual node once +it + + align:start position:0% +it + + + align:start position:0% +it +figured out who its parent was it could + + align:start position:0% +figured out who its parent was it could + + + align:start position:0% +figured out who its parent was it could +just output that + + align:start position:0% +just output that + + + align:start position:0% +just output that +and now you can figure out your parent + + align:start position:0% +and now you can figure out your parent + + + align:start position:0% +and now you can figure out your parent +but it's just a guess + + align:start position:0% +but it's just a guess + + + align:start position:0% +but it's just a guess +and you don't know when you can output + + align:start position:0% +and you don't know when you can output + + + align:start position:0% +and you don't know when you can output +this so how does a process + + align:start position:0% +this so how does a process + + + align:start position:0% +this so how does a process +even an individual process even figure + + align:start position:0% +even an individual process even figure + + + align:start position:0% +even an individual process even figure +out its own parent and distance + + align:start position:0% +out its own parent and distance + + + align:start position:0% +out its own parent and distance +so there's two aspects here + + align:start position:0% +so there's two aspects here + + + align:start position:0% +so there's two aspects here +determination one is how do you know the + + align:start position:0% +determination one is how do you know the + + + align:start position:0% +determination one is how do you know the +whole thing is finished + + align:start position:0% +whole thing is finished + + + align:start position:0% +whole thing is finished +but the other one is even how do you + + align:start position:0% +but the other one is even how do you + + + align:start position:0% +but the other one is even how do you +know when you're done with your own + + align:start position:0% +know when you're done with your own + + + align:start position:0% +know when you're done with your own +parent and distance + + align:start position:0% +parent and distance + + + align:start position:0% +parent and distance +okay well you know if you knew something + + align:start position:0% +okay well you know if you knew something + + + align:start position:0% +okay well you know if you knew something +about the graph like an upper bound on + + align:start position:0% +about the graph like an upper bound on + + + align:start position:0% +about the graph like an upper bound on +the total number of nodes then you could + + align:start position:0% +the total number of nodes then you could + + + align:start position:0% +the total number of nodes then you could +just wait until that number of rounds + + align:start position:0% +just wait until that number of rounds + + + align:start position:0% +just wait until that number of rounds +and be done but what if you + + align:start position:0% +and be done but what if you + + + align:start position:0% +and be done but what if you +don't have that information about the + + align:start position:0% +don't have that information about the + + + align:start position:0% +don't have that information about the +graph + + align:start position:0% +graph + + + align:start position:0% +graph +what might you do + + align:start position:0% + + + + align:start position:0% + +we yeah down the information when we + + align:start position:0% +we yeah down the information when we + + + align:start position:0% +we yeah down the information when we +reach + + align:start position:0% +reach + + + align:start position:0% +reach +the size of the graph oh maybe i think + + align:start position:0% +the size of the graph oh maybe i think + + + align:start position:0% +the size of the graph oh maybe i think +okay what is the strategy we use for + + align:start position:0% +okay what is the strategy we use for + + + align:start position:0% +okay what is the strategy we use for +termination for bfs + + align:start position:0% +termination for bfs + + + align:start position:0% +termination for bfs +let's start with that one it's a little + + align:start position:0% +let's start with that one it's a little + + + align:start position:0% +let's start with that one it's a little +easier + + align:start position:0% +easier + + + align:start position:0% +easier +you did the subtree thing we call + + align:start position:0% +you did the subtree thing we call + + + align:start position:0% +you did the subtree thing we call +converge cast the information + + align:start position:0% +converge cast the information + + + align:start position:0% +converge cast the information +when you had a leaf he knew he was a + + align:start position:0% +when you had a leaf he knew he was a + + + align:start position:0% +when you had a leaf he knew he was a +leaf and he could send his done + + align:start position:0% +leaf and he could send his done + + + align:start position:0% +leaf and he could send his done +information up to his parent and that + + align:start position:0% +information up to his parent and that + + + align:start position:0% +information up to his parent and that +got + + align:start position:0% +got + + + align:start position:0% +got +converged cast up to the top of the tree + + align:start position:0% +converged cast up to the top of the tree + + + align:start position:0% +converged cast up to the top of the tree +okay so can we converge cast in this + + align:start position:0% +okay so can we converge cast in this + + + align:start position:0% +okay so can we converge cast in this +setting + + align:start position:0% +setting + + + align:start position:0% +setting +turns out we can but since things are + + align:start position:0% +turns out we can but since things are + + + align:start position:0% +turns out we can but since things are +changing + + align:start position:0% +changing + + + align:start position:0% +changing +um you're going to be sending done + + align:start position:0% +um you're going to be sending done + + + align:start position:0% +um you're going to be sending done +messages and then something might change + + align:start position:0% +messages and then something might change + + + align:start position:0% +messages and then something might change +you might be participating in the + + align:start position:0% +you might be participating in the + + + align:start position:0% +you might be participating in the +converged cast many times + + align:start position:0% +converged cast many times + + + align:start position:0% +converged cast many times +okay so since the tree structure is + + align:start position:0% +okay so since the tree structure is + + + align:start position:0% +okay so since the tree structure is +changing + + align:start position:0% +changing + + + align:start position:0% +changing +the main idea is anybody can send a done + + align:start position:0% +the main idea is anybody can send a done + + + align:start position:0% +the main idea is anybody can send a done +message + + align:start position:0% +message + + + align:start position:0% +message +to its current the parent that he + + align:start position:0% +to its current the parent that he + + + align:start position:0% +to its current the parent that he +the note he believes is his parent + + align:start position:0% +the note he believes is his parent + + + align:start position:0% +the note he believes is his parent +provided + + align:start position:0% +provided + + + align:start position:0% +provided +his received responses to all of its uh + + align:start position:0% +his received responses to all of its uh + + + align:start position:0% +his received responses to all of its uh +distance messages so it thinks it's no + + align:start position:0% +distance messages so it thinks it's no + + + align:start position:0% +distance messages so it thinks it's no +it knows who all its children are okay + + align:start position:0% +it knows who all its children are okay + + + align:start position:0% +it knows who all its children are okay +so it has a current estimate of all the + + align:start position:0% +so it has a current estimate of all the + + + align:start position:0% +so it has a current estimate of all the +children + + align:start position:0% +children + + + align:start position:0% +children +and okay so if it knows all its children + + align:start position:0% +and okay so if it knows all its children + + + align:start position:0% +and okay so if it knows all its children +and they have all sent him done messages + + align:start position:0% +and they have all sent him done messages + + + align:start position:0% +and they have all sent him done messages +so for all your current children your + + align:start position:0% +so for all your current children your + + + align:start position:0% +so for all your current children your +current belief or who your children are + + align:start position:0% +current belief or who your children are + + + align:start position:0% +current belief or who your children are +if they've all send you + + align:start position:0% +if they've all send you + + + align:start position:0% +if they've all send you +sent you done messages then you can send + + align:start position:0% +sent you done messages then you can send + + + align:start position:0% +sent you done messages then you can send +a done message up the tree + + align:start position:0% +a done message up the tree + + + align:start position:0% +a done message up the tree +okay but this can get a little more + + align:start position:0% +okay but this can get a little more + + + align:start position:0% +okay but this can get a little more +complicated than it sounds because + + align:start position:0% +complicated than it sounds because + + + align:start position:0% +complicated than it sounds because +you can change who your children are + + align:start position:0% +you can change who your children are + + + align:start position:0% +you can change who your children are +so this what this means is that the same + + align:start position:0% +so this what this means is that the same + + + align:start position:0% +so this what this means is that the same +process can be involved several times in + + align:start position:0% +process can be involved several times in + + + align:start position:0% +process can be involved several times in +the converge cast + + align:start position:0% +the converge cast + + + align:start position:0% +the converge cast +based on improving the estimates + + align:start position:0% +based on improving the estimates + + + align:start position:0% +based on improving the estimates +so here's an example um + + align:start position:0% +so here's an example um + + + align:start position:0% +so here's an example um +so of the kind of thing that can happen + + align:start position:0% +so of the kind of thing that can happen + + + align:start position:0% +so of the kind of thing that can happen +so let's say you start out + + align:start position:0% +so let's say you start out + + + align:start position:0% +so let's say you start out +you have these huge weights and then you + + align:start position:0% +you have these huge weights and then you + + + align:start position:0% +you have these huge weights and then you +have a long path with small weights so + + align:start position:0% +have a long path with small weights so + + + align:start position:0% +have a long path with small weights so +i zero starts out and sends + + align:start position:0% +i zero starts out and sends + + + align:start position:0% +i zero starts out and sends +its distance information on its three + + align:start position:0% +its distance information on its three + + + align:start position:0% +its distance information on its three +nodes three to its three neighbors + + align:start position:0% +nodes three to its three neighbors + + + align:start position:0% +nodes three to its three neighbors +and this guy at the bottom + + align:start position:0% + + + + align:start position:0% + +now has a distance estimate of 100 and + + align:start position:0% +now has a distance estimate of 100 and + + + align:start position:0% +now has a distance estimate of 100 and +it's going to decide it's a leaf + + align:start position:0% +it's going to decide it's a leaf + + + align:start position:0% +it's going to decide it's a leaf +why because when it sends + + align:start position:0% +why because when it sends + + + align:start position:0% +why because when it sends +messages to its children to its + + align:start position:0% +messages to its children to its + + + align:start position:0% +messages to its children to its +neighbors + + align:start position:0% +neighbors + + + align:start position:0% +neighbors +they're not able to improve their + + align:start position:0% +they're not able to improve their + + + align:start position:0% +they're not able to improve their +estimates based on the new information + + align:start position:0% +estimates based on the new information + + + align:start position:0% +estimates based on the new information +that he's sending + + align:start position:0% +that he's sending + + + align:start position:0% +that he's sending +so this guy decides that he's a leaf + + align:start position:0% +so this guy decides that he's a leaf + + + align:start position:0% +so this guy decides that he's a leaf +right away + + align:start position:0% +right away + + + align:start position:0% +right away +and he sends that information back to + + align:start position:0% +and he sends that information back to + + + align:start position:0% +and he sends that information back to +node i zero on the other hand this guy + + align:start position:0% +node i zero on the other hand this guy + + + align:start position:0% +node i zero on the other hand this guy +has the same estimate of a hundred + + align:start position:0% +has the same estimate of a hundred + + + align:start position:0% +has the same estimate of a hundred +and he's n he sends out his messages to + + align:start position:0% +and he's n he sends out his messages to + + + align:start position:0% +and he's n he sends out his messages to +try to find out if he's a leaf + + align:start position:0% +try to find out if he's a leaf + + + align:start position:0% +try to find out if he's a leaf +but he finds out when he sends a message + + align:start position:0% +but he finds out when he sends a message + + + align:start position:0% +but he finds out when he sends a message +this way that he's actually able to + + align:start position:0% +this way that he's actually able to + + + align:start position:0% +this way that he's actually able to +improve that neighbor's estimate because + + align:start position:0% +improve that neighbor's estimate because + + + align:start position:0% +improve that neighbor's estimate because +that was infinity up to + + align:start position:0% +that was infinity up to + + + align:start position:0% +that was infinity up to +till then so he doesn't think he's a + + align:start position:0% +till then so he doesn't think he's a + + + align:start position:0% +till then so he doesn't think he's a +leaf + + align:start position:0% +leaf + + + align:start position:0% +leaf +okay so we have this one guy who thinks + + align:start position:0% +okay so we have this one guy who thinks + + + align:start position:0% +okay so we have this one guy who thinks +he's a leaf and responds so this i zero + + align:start position:0% +he's a leaf and responds so this i zero + + + align:start position:0% +he's a leaf and responds so this i zero +is sitting there + + align:start position:0% +is sitting there + + + align:start position:0% +is sitting there +he has to wait to hear from his other + + align:start position:0% +he has to wait to hear from his other + + + align:start position:0% +he has to wait to hear from his other +children + + align:start position:0% +children + + + align:start position:0% +children +okay so far all right so in in the + + align:start position:0% +okay so far all right so in in the + + + align:start position:0% +okay so far all right so in in the +meantime the messages are going to + + align:start position:0% +meantime the messages are going to + + + align:start position:0% +meantime the messages are going to +eventually creep around + + align:start position:0% +eventually creep around + + + align:start position:0% +eventually creep around +and this node is going to get + + align:start position:0% +and this node is going to get + + + align:start position:0% +and this node is going to get +a smaller estimate based on the length + + align:start position:0% +a smaller estimate based on the length + + + align:start position:0% +a smaller estimate based on the length +of that long mini hop + + align:start position:0% +of that long mini hop + + + align:start position:0% +of that long mini hop +uh path okay so then he's going to + + align:start position:0% +uh path okay so then he's going to + + + align:start position:0% +uh path okay so then he's going to +decide he is not a child of + + align:start position:0% +decide he is not a child of + + + align:start position:0% +decide he is not a child of +i zero so he's going to tell i zero i am + + align:start position:0% +i zero so he's going to tell i zero i am + + + align:start position:0% +i zero so he's going to tell i zero i am +i'm really not your child which means + + align:start position:0% +i'm really not your child which means + + + align:start position:0% +i'm really not your child which means +that i zero stops waiting for it + + align:start position:0% +that i zero stops waiting for it + + + align:start position:0% +that i zero stops waiting for it +but also this guy decides he's not a + + align:start position:0% +but also this guy decides he's not a + + + align:start position:0% +but also this guy decides he's not a +child as well + + align:start position:0% +child as well + + + align:start position:0% +child as well +he becomes a child at the node right up + + align:start position:0% +he becomes a child at the node right up + + + align:start position:0% +he becomes a child at the node right up +right above him + + align:start position:0% +right above him + + + align:start position:0% +right above him +so i zero now will realize he only has + + align:start position:0% +so i zero now will realize he only has + + + align:start position:0% +so i zero now will realize he only has +one + + align:start position:0% +one + + + align:start position:0% +one +one child but this guy + + align:start position:0% +one child but this guy + + + align:start position:0% +one child but this guy +believes he's a leaf again after trying + + align:start position:0% +believes he's a leaf again after trying + + + align:start position:0% +believes he's a leaf again after trying +again + + align:start position:0% +again + + + align:start position:0% +again +to find children and now the done + + align:start position:0% +to find children and now the done + + + align:start position:0% +to find children and now the done +information propagates all the way up + + align:start position:0% +information propagates all the way up + + + align:start position:0% +information propagates all the way up +the tree which is now just this one long + + align:start position:0% +the tree which is now just this one long + + + align:start position:0% +the tree which is now just this one long +path + + align:start position:0% +path + + + align:start position:0% +path +okay so they start trying to converge + + align:start position:0% +okay so they start trying to converge + + + align:start position:0% +okay so they start trying to converge +cast + + align:start position:0% +cast + + + align:start position:0% +cast +but then oops they were wrong they have + + align:start position:0% +but then oops they were wrong they have + + + align:start position:0% +but then oops they were wrong they have +to make a correction + + align:start position:0% +to make a correction + + + align:start position:0% +to make a correction +and that they are forming a new tree + + align:start position:0% +and that they are forming a new tree + + + align:start position:0% +and that they are forming a new tree +eventually the tree is going to + + align:start position:0% +eventually the tree is going to + + + align:start position:0% +eventually the tree is going to +stabilize + + align:start position:0% +stabilize + + + align:start position:0% +stabilize +and eventually the done information will + + align:start position:0% +and eventually the done information will + + + align:start position:0% +and eventually the done information will +get all the way up to the top + + align:start position:0% +get all the way up to the top + + + align:start position:0% +get all the way up to the top +but there can be lots of false starts in + + align:start position:0% +but there can be lots of false starts in + + + align:start position:0% +but there can be lots of false starts in +the meantime + + align:start position:0% +the meantime + + + align:start position:0% +the meantime +okay it's sort of confusing but that's + + align:start position:0% +okay it's sort of confusing but that's + + + align:start position:0% +okay it's sort of confusing but that's +the kind of thing that happens yeah + + align:start position:0% +the kind of thing that happens yeah + + + align:start position:0% +the kind of thing that happens yeah +so + + align:start position:0% + + + + align:start position:0% + +yeah so the root note isn't going to + + align:start position:0% +yeah so the root note isn't going to + + + align:start position:0% +yeah so the root note isn't going to +terminate until it hears from everybody + + align:start position:0% +terminate until it hears from everybody + + + align:start position:0% +terminate until it hears from everybody +you kind of have to close out the whole + + align:start position:0% +you kind of have to close out the whole + + + align:start position:0% +you kind of have to close out the whole +process + + align:start position:0% +process + + + align:start position:0% +process +so it's always pending waiting for + + align:start position:0% +so it's always pending waiting for + + + align:start position:0% +so it's always pending waiting for +somebody if it hasn't heard from someone + + align:start position:0% +somebody if it hasn't heard from someone + + + align:start position:0% +somebody if it hasn't heard from someone +if things switch they'll join in on + + align:start position:0% +if things switch they'll join in on + + + align:start position:0% +if things switch they'll join in on +another part of the tree + + align:start position:0% +another part of the tree + + + align:start position:0% +another part of the tree +i think the best thing to do here is + + align:start position:0% +i think the best thing to do here is + + + align:start position:0% +i think the best thing to do here is +sort of construct some little examples + + align:start position:0% +sort of construct some little examples + + + align:start position:0% +sort of construct some little examples +by hand + + align:start position:0% +by hand + + + align:start position:0% +by hand +i mean we're not going to get into how + + align:start position:0% +i mean we're not going to get into how + + + align:start position:0% +i mean we're not going to get into how +you do formal proofs of things like this + + align:start position:0% +you do formal proofs of things like this + + + align:start position:0% +you do formal proofs of things like this +we don't even have right now a simulator + + align:start position:0% +we don't even have right now a simulator + + + align:start position:0% +we don't even have right now a simulator +you can use to play with these + + align:start position:0% +you can use to play with these + + + align:start position:0% +you can use to play with these +algorithms although if anybody's + + align:start position:0% +algorithms although if anybody's + + + align:start position:0% +algorithms although if anybody's +interested there + + align:start position:0% +interested there + + + align:start position:0% +interested there +some students in my class last term + + align:start position:0% +some students in my class last term + + + align:start position:0% +some students in my class last term +actually wrote a simulator it might be a + + align:start position:0% +actually wrote a simulator it might be a + + + align:start position:0% +actually wrote a simulator it might be a +belt + + align:start position:0% + + + + align:start position:0% + +okay so + + align:start position:0% +okay so + + + align:start position:0% +okay so +all right so that's uh what you get for + + align:start position:0% +all right so that's uh what you get for + + + align:start position:0% +all right so that's uh what you get for +a synchronous + + align:start position:0% +a synchronous + + + align:start position:0% +a synchronous +some example synchronous distributed + + align:start position:0% +some example synchronous distributed + + + align:start position:0% +some example synchronous distributed +algorithms + + align:start position:0% +algorithms + + + align:start position:0% +algorithms +so now let's look at something more + + align:start position:0% +so now let's look at something more + + + align:start position:0% +so now let's look at something more +complicated when you get into + + align:start position:0% +complicated when you get into + + + align:start position:0% +complicated when you get into +asynchronous algorithms + + align:start position:0% +asynchronous algorithms + + + align:start position:0% +asynchronous algorithms +okay so so far complications that you've + + align:start position:0% +okay so so far complications that you've + + + align:start position:0% +okay so so far complications that you've +seen over the rest of this course + + align:start position:0% +seen over the rest of this course + + + align:start position:0% +seen over the rest of this course +um you have now processes that are + + align:start position:0% +um you have now processes that are + + + align:start position:0% +um you have now processes that are +acting concurrently + + align:start position:0% +acting concurrently + + + align:start position:0% +acting concurrently +and we had a little bit of + + align:start position:0% +and we had a little bit of + + + align:start position:0% +and we had a little bit of +non-determinism nothing important + + align:start position:0% +non-determinism nothing important + + + align:start position:0% +non-determinism nothing important +but now things are about to get much + + align:start position:0% +but now things are about to get much + + + align:start position:0% +but now things are about to get much +worse um + + align:start position:0% +worse um + + + align:start position:0% +worse um +we don't have rounds anymore uh so now + + align:start position:0% +we don't have rounds anymore uh so now + + + align:start position:0% +we don't have rounds anymore uh so now +we're going to have processes taking + + align:start position:0% +we're going to have processes taking + + + align:start position:0% +we're going to have processes taking +steps + + align:start position:0% +steps + + + align:start position:0% +steps +messages getting delivered at absolutely + + align:start position:0% +messages getting delivered at absolutely + + + align:start position:0% +messages getting delivered at absolutely +arbitrary times arbitrary orders + + align:start position:0% +arbitrary times arbitrary orders + + + align:start position:0% +arbitrary times arbitrary orders +okay the processes can get completely + + align:start position:0% +okay the processes can get completely + + + align:start position:0% +okay the processes can get completely +out of sync + + align:start position:0% +out of sync + + + align:start position:0% +out of sync +um and so you have lots lots more + + align:start position:0% +um and so you have lots lots more + + + align:start position:0% +um and so you have lots lots more +non-determinism + + align:start position:0% +non-determinism + + + align:start position:0% +non-determinism +in the algorithm the non-determinism has + + align:start position:0% +in the algorithm the non-determinism has + + + align:start position:0% +in the algorithm the non-determinism has +to do with who's doing what in what + + align:start position:0% +to do with who's doing what in what + + + align:start position:0% +to do with who's doing what in what +order + + align:start position:0% +order + + + align:start position:0% +order +okay so understanding + + align:start position:0% +okay so understanding + + + align:start position:0% +okay so understanding +that type of algorithm is really + + align:start position:0% +that type of algorithm is really + + + align:start position:0% +that type of algorithm is really +different from understanding the + + align:start position:0% +different from understanding the + + + align:start position:0% +different from understanding the +algorithms that you've seen all term and + + align:start position:0% +algorithms that you've seen all term and + + + align:start position:0% +algorithms that you've seen all term and +even synchronous + + align:start position:0% +even synchronous + + + align:start position:0% +even synchronous +uh distributed algorithms because there + + align:start position:0% +uh distributed algorithms because there + + + align:start position:0% +uh distributed algorithms because there +isn't just one way the algorithm is + + align:start position:0% +isn't just one way the algorithm is + + + align:start position:0% +isn't just one way the algorithm is +going to + + align:start position:0% +going to + + + align:start position:0% +going to +execute the execution can proceed in + + align:start position:0% +execute the execution can proceed in + + + align:start position:0% +execute the execution can proceed in +many different ways + + align:start position:0% +many different ways + + + align:start position:0% +many different ways +uh just depending on the order of the + + align:start position:0% +uh just depending on the order of the + + + align:start position:0% +uh just depending on the order of the +steps + + align:start position:0% +steps + + + align:start position:0% +steps +okay so you can't ever hope to + + align:start position:0% +okay so you can't ever hope to + + + align:start position:0% +okay so you can't ever hope to +understand exactly how this kind of + + align:start position:0% +understand exactly how this kind of + + + align:start position:0% +understand exactly how this kind of +algorithm is + + align:start position:0% +algorithm is + + + align:start position:0% +algorithm is +executing so what can you do well you + + align:start position:0% +executing so what can you do well you + + + align:start position:0% +executing so what can you do well you +can play with it but + + align:start position:0% +can play with it but + + + align:start position:0% +can play with it but +in the end what you have to understand + + align:start position:0% +in the end what you have to understand + + + align:start position:0% +in the end what you have to understand +is some abstract properties some + + align:start position:0% +is some abstract properties some + + + align:start position:0% +is some abstract properties some +properties of the executions rather than + + align:start position:0% +properties of the executions rather than + + + align:start position:0% +properties of the executions rather than +exactly what happens at every step and + + align:start position:0% +exactly what happens at every step and + + + align:start position:0% +exactly what happens at every step and +that's a a jump it's a new way of + + align:start position:0% +that's a a jump it's a new way of + + + align:start position:0% +that's a a jump it's a new way of +thinking + + align:start position:0% +thinking + + + align:start position:0% +thinking +okay so we can look at asynchronous + + align:start position:0% +okay so we can look at asynchronous + + + align:start position:0% +okay so we can look at asynchronous +stuff if you want from my book + + align:start position:0% +stuff if you want from my book + + + align:start position:0% +stuff if you want from my book +uh now okay we still have processes at + + align:start position:0% +uh now okay we still have processes at + + + align:start position:0% +uh now okay we still have processes at +the nodes of a graph + + align:start position:0% +the nodes of a graph + + + align:start position:0% +the nodes of a graph +and now we have communication channels + + align:start position:0% +and now we have communication channels + + + align:start position:0% +and now we have communication channels +associated with the edges + + align:start position:0% +associated with the edges + + + align:start position:0% +associated with the edges +so now the processes are going to be + + align:start position:0% +so now the processes are going to be + + + align:start position:0% +so now the processes are going to be +some kind of automata + + align:start position:0% +some kind of automata + + + align:start position:0% +some kind of automata +but the channels will also be some kind + + align:start position:0% +but the channels will also be some kind + + + align:start position:0% +but the channels will also be some kind +of automata we'll have all these + + align:start position:0% +of automata we'll have all these + + + align:start position:0% +of automata we'll have all these +components + + align:start position:0% +components + + + align:start position:0% +components +and we'll be modeling all of them + + align:start position:0% +and we'll be modeling all of them + + + align:start position:0% +and we'll be modeling all of them +processes still have their ports they + + align:start position:0% +processes still have their ports they + + + align:start position:0% +processes still have their ports they +need not in general have uh + + align:start position:0% +need not in general have uh + + + align:start position:0% +need not in general have uh +identifiers okay so what's a channel + + align:start position:0% +identifiers okay so what's a channel + + + align:start position:0% +identifiers okay so what's a channel +okay so a channel is a kind of an + + align:start position:0% +okay so a channel is a kind of an + + + align:start position:0% +okay so a channel is a kind of an +automaton infinite state automaton that + + align:start position:0% +automaton infinite state automaton that + + + align:start position:0% +automaton infinite state automaton that +has some inputs + + align:start position:0% +has some inputs + + + align:start position:0% +has some inputs +and some outputs so here this is just a + + align:start position:0% +and some outputs so here this is just a + + + align:start position:0% +and some outputs so here this is just a +little picture of a channel from one + + align:start position:0% +little picture of a channel from one + + + align:start position:0% +little picture of a channel from one +node to + + align:start position:0% +node to + + + align:start position:0% +node to +from node u to node v + + align:start position:0% +from node u to node v + + + align:start position:0% +from node u to node v +so channel uv is just this cloud thing + + align:start position:0% +so channel uv is just this cloud thing + + + align:start position:0% +so channel uv is just this cloud thing +that delivers messages + + align:start position:0% +that delivers messages + + + align:start position:0% +that delivers messages +it has inputs the inputs are messages + + align:start position:0% +it has inputs the inputs are messages + + + align:start position:0% +it has inputs the inputs are messages +get sent on the channel + + align:start position:0% +get sent on the channel + + + align:start position:0% +get sent on the channel +so you can have one process at one end + + align:start position:0% +so you can have one process at one end + + + align:start position:0% +so you can have one process at one end +sending a message m + + align:start position:0% +sending a message m + + + align:start position:0% +sending a message m +and the outputs at the other end are the + + align:start position:0% +and the outputs at the other end are the + + + align:start position:0% +and the outputs at the other end are the +deliveries let's say receive + + align:start position:0% +deliveries let's say receive + + + align:start position:0% +deliveries let's say receive +message m uh at the other end + + align:start position:0% +message m uh at the other end + + + align:start position:0% +message m uh at the other end +node v okay + + align:start position:0% +node v okay + + + align:start position:0% +node v okay +um okay to model this the best thing is + + align:start position:0% +um okay to model this the best thing is + + + align:start position:0% +um okay to model this the best thing is +actually to + + align:start position:0% +actually to + + + align:start position:0% +actually to +instead of just describing what it does + + align:start position:0% +instead of just describing what it does + + + align:start position:0% +instead of just describing what it does +to give an explicit model of its state + + align:start position:0% +to give an explicit model of its state + + + align:start position:0% +to give an explicit model of its state +and what happens when the inputs and + + align:start position:0% +and what happens when the inputs and + + + align:start position:0% +and what happens when the inputs and +outputs occur + + align:start position:0% +outputs occur + + + align:start position:0% +outputs occur +so if you want these messages to be + + align:start position:0% +so if you want these messages to be + + + align:start position:0% +so if you want these messages to be +delivered say in fifo order + + align:start position:0% +delivered say in fifo order + + + align:start position:0% +delivered say in fifo order +fine so you can make the state of the + + align:start position:0% +fine so you can make the state of the + + + align:start position:0% +fine so you can make the state of the +channel be an actual cue + + align:start position:0% +channel be an actual cue + + + align:start position:0% +channel be an actual cue +mq would just be a fifo queue of + + align:start position:0% +mq would just be a fifo queue of + + + align:start position:0% +mq would just be a fifo queue of +messages + + align:start position:0% +messages + + + align:start position:0% +messages +it starts out empty then when messages + + align:start position:0% +it starts out empty then when messages + + + align:start position:0% +it starts out empty then when messages +get sent they get added to the end and + + align:start position:0% +get sent they get added to the end and + + + align:start position:0% +get sent they get added to the end and +get delivered they get removed from the + + align:start position:0% +get delivered they get removed from the + + + align:start position:0% +get delivered they get removed from the +beginning + + align:start position:0% +beginning + + + align:start position:0% +beginning +so all that we need to describe this is + + align:start position:0% +so all that we need to describe this is + + + align:start position:0% +so all that we need to describe this is +a sort of a pseudocode + + align:start position:0% +a sort of a pseudocode + + + align:start position:0% +a sort of a pseudocode +all we need to describe uh to write in + + align:start position:0% +all we need to describe uh to write in + + + align:start position:0% +all we need to describe uh to write in +order to describe what this + + align:start position:0% +order to describe what this + + + align:start position:0% +order to describe what this +channel does is what happens when a send + + align:start position:0% +channel does is what happens when a send + + + align:start position:0% +channel does is what happens when a send +occurs + + align:start position:0% +occurs + + + align:start position:0% +occurs +and when can this channel do uh deliver + + align:start position:0% +and when can this channel do uh deliver + + + align:start position:0% +and when can this channel do uh deliver +a message and what happens when it does + + align:start position:0% +a message and what happens when it does + + + align:start position:0% +a message and what happens when it does +that + + align:start position:0% +that + + + align:start position:0% +that +so ascend which can just come in at any + + align:start position:0% +so ascend which can just come in at any + + + align:start position:0% +so ascend which can just come in at any +time and the effect is just to add this + + align:start position:0% +time and the effect is just to add this + + + align:start position:0% +time and the effect is just to add this +message + + align:start position:0% +message + + + align:start position:0% +message +to the end of the queue the receive + + align:start position:0% +to the end of the queue the receive + + + align:start position:0% +to the end of the queue the receive +stop moving + + align:start position:0% + + + + align:start position:0% + +the receive + + align:start position:0% + + + + align:start position:0% + +that cannot be construction we'd hear + + align:start position:0% +that cannot be construction we'd hear + + + align:start position:0% +that cannot be construction we'd hear +noise + + align:start position:0% +noise + + + align:start position:0% +noise +it's gremlins we have + + align:start position:0% + + + + align:start position:0% + +a receive can occur only when this + + align:start position:0% +a receive can occur only when this + + + align:start position:0% +a receive can occur only when this +message is at the head of the queue + + align:start position:0% +message is at the head of the queue + + + align:start position:0% +message is at the head of the queue +and when it occurs it gets removed from + + align:start position:0% +and when it occurs it gets removed from + + + align:start position:0% +and when it occurs it gets removed from +the queue + + align:start position:0% +the queue + + + align:start position:0% +the queue +so does this make sense as a description + + align:start position:0% +so does this make sense as a description + + + align:start position:0% +so does this make sense as a description +of what a channel does + + align:start position:0% +of what a channel does + + + align:start position:0% +of what a channel does +messages come in get added to it and + + align:start position:0% +messages come in get added to it and + + + align:start position:0% +messages come in get added to it and +then messages can get delivered + + align:start position:0% +then messages can get delivered + + + align:start position:0% +then messages can get delivered +in certain situations and they get + + align:start position:0% +in certain situations and they get + + + align:start position:0% +in certain situations and they get +removed + + align:start position:0% +removed + + + align:start position:0% +removed +okay so that's a description of a + + align:start position:0% +okay so that's a description of a + + + align:start position:0% +okay so that's a description of a +channel in it to be used in asynchronous + + align:start position:0% +channel in it to be used in asynchronous + + + align:start position:0% +channel in it to be used in asynchronous +system + + align:start position:0% +system + + + align:start position:0% +system +okay a process the rest of the the + + align:start position:0% +okay a process the rest of the the + + + align:start position:0% +okay a process the rest of the the +system consists of processes + + align:start position:0% +system consists of processes + + + align:start position:0% +system consists of processes +associated with graph vertices so let's + + align:start position:0% +associated with graph vertices so let's + + + align:start position:0% +associated with graph vertices so let's +say p + + align:start position:0% +say p + + + align:start position:0% +say p +u is a process that's associated with + + align:start position:0% +u is a process that's associated with + + + align:start position:0% +u is a process that's associated with +vertex u + + align:start position:0% +vertex u + + + align:start position:0% +vertex u +but i'm writing that just sort of as a + + align:start position:0% +but i'm writing that just sort of as a + + + align:start position:0% +but i'm writing that just sort of as a +shorthand because u is the + + align:start position:0% +shorthand because u is the + + + align:start position:0% +shorthand because u is the +vertex in the graph and the process + + align:start position:0% +vertex in the graph and the process + + + align:start position:0% +vertex in the graph and the process +doesn't actually know + + align:start position:0% +doesn't actually know + + + align:start position:0% +doesn't actually know +the name of the vertex it just has like + + align:start position:0% +the name of the vertex it just has like + + + align:start position:0% +the name of the vertex it just has like +its own unique id + + align:start position:0% +its own unique id + + + align:start position:0% +its own unique id +or something but i'm going to be a + + align:start position:0% +or something but i'm going to be a + + + align:start position:0% +or something but i'm going to be a +little sloppy about that now + + align:start position:0% +little sloppy about that now + + + align:start position:0% +little sloppy about that now +okay so the process at vertex u + + align:start position:0% +okay so the process at vertex u + + + align:start position:0% +okay so the process at vertex u +can perform send outputs to put messages + + align:start position:0% +can perform send outputs to put messages + + + align:start position:0% +can perform send outputs to put messages +on the channel + + align:start position:0% +on the channel + + + align:start position:0% +on the channel +and it will get receive inputs for + + align:start position:0% +and it will get receive inputs for + + + align:start position:0% +and it will get receive inputs for +messages to come in on the channels + + align:start position:0% +messages to come in on the channels + + + align:start position:0% +messages to come in on the channels +but the processes might also have some + + align:start position:0% +but the processes might also have some + + + align:start position:0% +but the processes might also have some +external interface where somebody is + + align:start position:0% +external interface where somebody is + + + align:start position:0% +external interface where somebody is +submitting some inputs to the process + + align:start position:0% +submitting some inputs to the process + + + align:start position:0% +submitting some inputs to the process +and the process has to produce some + + align:start position:0% +and the process has to produce some + + + align:start position:0% +and the process has to produce some +output at the end + + align:start position:0% +output at the end + + + align:start position:0% +output at the end +so there can be other inputs and outputs + + align:start position:0% +so there can be other inputs and outputs + + + align:start position:0% +so there can be other inputs and outputs +okay uh and we'll model it with state + + align:start position:0% +okay uh and we'll model it with state + + + align:start position:0% +okay uh and we'll model it with state +variables + + align:start position:0% +variables + + + align:start position:0% +variables +okay process is supposed to keep taking + + align:start position:0% +okay process is supposed to keep taking + + + align:start position:0% +okay process is supposed to keep taking +steps the channel is supposed to keep + + align:start position:0% +steps the channel is supposed to keep + + + align:start position:0% +steps the channel is supposed to keep +delivering messages that's a + + align:start position:0% +delivering messages that's a + + + align:start position:0% +delivering messages that's a +it's a property called liveness you want + + align:start position:0% +it's a property called liveness you want + + + align:start position:0% +it's a property called liveness you want +to make sure that your components in + + align:start position:0% +to make sure that your components in + + + align:start position:0% +to make sure that your components in +your system all keep + + align:start position:0% +your system all keep + + + align:start position:0% +your system all keep +doing things they don't just do some + + align:start position:0% +doing things they don't just do some + + + align:start position:0% +doing things they don't just do some +steps and then stop + + align:start position:0% +steps and then stop + + + align:start position:0% +steps and then stop +okay so here's a simple example a + + align:start position:0% +okay so here's a simple example a + + + align:start position:0% +okay so here's a simple example a +process that + + align:start position:0% +process that + + + align:start position:0% +process that +that's remembering the maximum number + + align:start position:0% +that's remembering the maximum number + + + align:start position:0% +that's remembering the maximum number +it's ever seen + + align:start position:0% +it's ever seen + + + align:start position:0% +it's ever seen +so there's a max process automaton it + + align:start position:0% +so there's a max process automaton it + + + align:start position:0% +so there's a max process automaton it +receives + + align:start position:0% +receives + + + align:start position:0% +receives +some messages m some value + + align:start position:0% +some messages m some value + + + align:start position:0% +some messages m some value +and it will send it out it keeps track + + align:start position:0% +and it will send it out it keeps track + + + align:start position:0% +and it will send it out it keeps track +of the max that's a + + align:start position:0% +of the max that's a + + + align:start position:0% +of the max that's a +max state variable it starts out with + + align:start position:0% +max state variable it starts out with + + + align:start position:0% +max state variable it starts out with +its own initial value so x for u + + align:start position:0% +its own initial value so x for u + + + align:start position:0% +its own initial value so x for u +x sub u is its initial value + + align:start position:0% +x sub u is its initial value + + + align:start position:0% +x sub u is its initial value +and then it has for every neighbor + + align:start position:0% +and then it has for every neighbor + + + align:start position:0% +and then it has for every neighbor +it has a a little um hue + + align:start position:0% +it has a a little um hue + + + align:start position:0% +it has a a little um hue +here it's just a boolean uh asking + + align:start position:0% +here it's just a boolean uh asking + + + align:start position:0% +here it's just a boolean uh asking +whether it's supposed to send + + align:start position:0% +whether it's supposed to send + + + align:start position:0% +whether it's supposed to send +to that neighbor okay + + align:start position:0% +to that neighbor okay + + + align:start position:0% +to that neighbor okay +um so this is the pseudo code for uh the + + align:start position:0% +um so this is the pseudo code for uh the + + + align:start position:0% +um so this is the pseudo code for uh the +max process + + align:start position:0% +max process + + + align:start position:0% +max process +what does it do when it receives a + + align:start position:0% +what does it do when it receives a + + + align:start position:0% +what does it do when it receives a +message well it sees if that + + align:start position:0% +message well it sees if that + + + align:start position:0% +message well it sees if that +value is bigger than what it had before + + align:start position:0% +value is bigger than what it had before + + + align:start position:0% +value is bigger than what it had before +and if so it resets the max + + align:start position:0% +and if so it resets the max + + + align:start position:0% +and if so it resets the max +and it also makes a note that it's + + align:start position:0% +and it also makes a note that it's + + + align:start position:0% +and it also makes a note that it's +supposed to send this out to all its + + align:start position:0% +supposed to send this out to all its + + + align:start position:0% +supposed to send this out to all its +neighbors whenever it gets new + + align:start position:0% +neighbors whenever it gets new + + + align:start position:0% +neighbors whenever it gets new +information + + align:start position:0% +information + + + align:start position:0% +information +it will want to propagate it to its + + align:start position:0% +it will want to propagate it to its + + + align:start position:0% +it will want to propagate it to its +neighbors + + align:start position:0% +neighbors + + + align:start position:0% +neighbors +so you see how this is written you just + + align:start position:0% +so you see how this is written you just + + + align:start position:0% +so you see how this is written you just +say you know reset the max and + + align:start position:0% +say you know reset the max and + + + align:start position:0% +say you know reset the max and +then get ready to send to all your + + align:start position:0% +then get ready to send to all your + + + align:start position:0% +then get ready to send to all your +neighbors + + align:start position:0% +neighbors + + + align:start position:0% +neighbors +and the last part is just sort of + + align:start position:0% +and the last part is just sort of + + + align:start position:0% +and the last part is just sort of +trivial code it says if you + + align:start position:0% +trivial code it says if you + + + align:start position:0% +trivial code it says if you +are ready to send then you can send and + + align:start position:0% +are ready to send then you can send and + + + align:start position:0% +are ready to send then you can send and +then you you know you're done and you + + align:start position:0% +then you you know you're done and you + + + align:start position:0% +then you you know you're done and you +can set the send flags to false + + align:start position:0% +can set the send flags to false + + + align:start position:0% +can set the send flags to false +yeah um for every + + align:start position:0% +yeah um for every + + + align:start position:0% +yeah um for every +neighbor oh i wrote neighbor v before + + align:start position:0% +neighbor oh i wrote neighbor v before + + + align:start position:0% +neighbor oh i wrote neighbor v before +and then i + + align:start position:0% +and then i + + + align:start position:0% +and then i +yeah i wrote neighbor oh i know why i + + align:start position:0% +yeah i wrote neighbor oh i know why i + + + align:start position:0% +yeah i wrote neighbor oh i know why i +wrote w + + align:start position:0% +wrote w + + + align:start position:0% +wrote w +so here i'm talking about if you receive + + align:start position:0% +so here i'm talking about if you receive + + + align:start position:0% +so here i'm talking about if you receive +a message from a particular neighbor v + + align:start position:0% +a message from a particular neighbor v + + + align:start position:0% +a message from a particular neighbor v +then you have to send it to all your + + align:start position:0% +then you have to send it to all your + + + align:start position:0% +then you have to send it to all your +neighbors so before i + + align:start position:0% +neighbors so before i + + + align:start position:0% +neighbors so before i +i used v to denote a generic neighbor + + align:start position:0% +i used v to denote a generic neighbor + + + align:start position:0% +i used v to denote a generic neighbor +but now i can't do that anymore + + align:start position:0% +but now i can't do that anymore + + + align:start position:0% +but now i can't do that anymore +because v is the center of the message + + align:start position:0% +because v is the center of the message + + + align:start position:0% +because v is the center of the message +just technical + + align:start position:0% +just technical + + + align:start position:0% +just technical +okay + + align:start position:0% + + + + align:start position:0% + +okay so we we have these process + + align:start position:0% +okay so we we have these process + + + align:start position:0% +okay so we we have these process +automata we have these channel + + align:start position:0% +automata we have these channel + + + align:start position:0% +automata we have these channel +automata now we want to build the system + + align:start position:0% +automata now we want to build the system + + + align:start position:0% +automata now we want to build the system +we paste them together + + align:start position:0% +we paste them together + + + align:start position:0% +we paste them together +okay so how we paste them is just we + + align:start position:0% +okay so how we paste them is just we + + + align:start position:0% +okay so how we paste them is just we +have + + align:start position:0% +have + + + align:start position:0% +have +outputs from processes that can match up + + align:start position:0% +outputs from processes that can match up + + + align:start position:0% +outputs from processes that can match up +with inputs to channels + + align:start position:0% +with inputs to channels + + + align:start position:0% +with inputs to channels +and vice versa if a process has a send + + align:start position:0% +and vice versa if a process has a send + + + align:start position:0% +and vice versa if a process has a send +output + + align:start position:0% +output + + + align:start position:0% +output +let's say send from u to v that will + + align:start position:0% +let's say send from u to v that will + + + align:start position:0% +let's say send from u to v that will +match up with + + align:start position:0% +match up with + + + align:start position:0% +match up with +the channel that has send uv as an input + + align:start position:0% +the channel that has send uv as an input + + + align:start position:0% +the channel that has send uv as an input +and the receive from the channel matches + + align:start position:0% +and the receive from the channel matches + + + align:start position:0% +and the receive from the channel matches +up with the process that has that + + align:start position:0% +up with the process that has that + + + align:start position:0% +up with the process that has that +received as an input + + align:start position:0% +received as an input + + + align:start position:0% +received as an input +okay so all i'm doing is matching up + + align:start position:0% +okay so all i'm doing is matching up + + + align:start position:0% +okay so all i'm doing is matching up +these um + + align:start position:0% +these um + + + align:start position:0% +these um +components i'm hooking together these + + align:start position:0% +components i'm hooking together these + + + align:start position:0% +components i'm hooking together these +components by matching up their action + + align:start position:0% +components by matching up their action + + + align:start position:0% +components by matching up their action +names + + align:start position:0% +names + + + align:start position:0% +names +does that make sense so i'm + + align:start position:0% +does that make sense so i'm + + + align:start position:0% +does that make sense so i'm +saying how i build a system out of all + + align:start position:0% +saying how i build a system out of all + + + align:start position:0% +saying how i build a system out of all +these components and i just have a + + align:start position:0% +these components and i just have a + + + align:start position:0% +these components and i just have a +syntactic way of saying + + align:start position:0% +syntactic way of saying + + + align:start position:0% +syntactic way of saying +what actions match up in different + + align:start position:0% +what actions match up in different + + + align:start position:0% +what actions match up in different +components + + align:start position:0% +components + + + align:start position:0% +components +questions this is all new + + align:start position:0% + + + + align:start position:0% + +okay so when when this system takes a + + align:start position:0% +okay so when when this system takes a + + + align:start position:0% +okay so when when this system takes a +step well + + align:start position:0% +step well + + + align:start position:0% +step well +if there's um if somebody's performing + + align:start position:0% +if there's um if somebody's performing + + + align:start position:0% +if there's um if somebody's performing +an action + + align:start position:0% +an action + + + align:start position:0% +an action +and someone else has that same action + + align:start position:0% +and someone else has that same action + + + align:start position:0% +and someone else has that same action +let's say a process is doing ascend the + + align:start position:0% +let's say a process is doing ascend the + + + align:start position:0% +let's say a process is doing ascend the +channel has ascend + + align:start position:0% +channel has ascend + + + align:start position:0% +channel has ascend +they both take their transitions at the + + align:start position:0% +they both take their transitions at the + + + align:start position:0% +they both take their transitions at the +same time the process sends a message + + align:start position:0% +same time the process sends a message + + + align:start position:0% +same time the process sends a message +it gets put into the channel at the end + + align:start position:0% +it gets put into the channel at the end + + + align:start position:0% +it gets put into the channel at the end +of its queue + + align:start position:0% + + + + align:start position:0% + +makes sense okay + + align:start position:0% +makes sense okay + + + align:start position:0% +makes sense okay +so how does this thing execute well + + align:start position:0% +so how does this thing execute well + + + align:start position:0% +so how does this thing execute well +there's no synchronous rounds + + align:start position:0% +there's no synchronous rounds + + + align:start position:0% +there's no synchronous rounds +so the the system just operates by the + + align:start position:0% +so the the system just operates by the + + + align:start position:0% +so the the system just operates by the +processes and the channels just perform + + align:start position:0% +processes and the channels just perform + + + align:start position:0% +processes and the channels just perform +their steps in any order + + align:start position:0% +their steps in any order + + + align:start position:0% +their steps in any order +one at a time but it can be in any order + + align:start position:0% +one at a time but it can be in any order + + + align:start position:0% +one at a time but it can be in any order +so it's a sequence model you just have a + + align:start position:0% +so it's a sequence model you just have a + + + align:start position:0% +so it's a sequence model you just have a +sequence of individual steps + + align:start position:0% +sequence of individual steps + + + align:start position:0% +sequence of individual steps +um there's no concurrency here in the + + align:start position:0% +um there's no concurrency here in the + + + align:start position:0% +um there's no concurrency here in the +the synchronous model we had + + align:start position:0% +the synchronous model we had + + + align:start position:0% +the synchronous model we had +everybody taking their steps in one big + + align:start position:0% +everybody taking their steps in one big + + + align:start position:0% +everybody taking their steps in one big +block and here it's just + + align:start position:0% +block and here it's just + + + align:start position:0% +block and here it's just +uh they take steps one at a time but it + + align:start position:0% +uh they take steps one at a time but it + + + align:start position:0% +uh they take steps one at a time but it +could be in any order + + align:start position:0% +could be in any order + + + align:start position:0% +could be in any order +okay and we have to make sure that + + align:start position:0% +okay and we have to make sure that + + + align:start position:0% +okay and we have to make sure that +everybody keeps taking steps that + + align:start position:0% +everybody keeps taking steps that + + + align:start position:0% +everybody keeps taking steps that +every channel continues to deliver + + align:start position:0% +every channel continues to deliver + + + align:start position:0% +every channel continues to deliver +messages + + align:start position:0% +messages + + + align:start position:0% +messages +and every process always performs + + align:start position:0% +and every process always performs + + + align:start position:0% +and every process always performs +some step that's enabled + + align:start position:0% + + + + align:start position:0% + +so for the max processes well we can + + align:start position:0% +so for the max processes well we can + + + align:start position:0% +so for the max processes well we can +just + + align:start position:0% + + + + align:start position:0% + +have a bunch of processes each one now + + align:start position:0% +have a bunch of processes each one now + + + align:start position:0% +have a bunch of processes each one now +starting with its initial value + + align:start position:0% +starting with its initial value + + + align:start position:0% +starting with its initial value +and what happens when we plug them + + align:start position:0% +and what happens when we plug them + + + align:start position:0% +and what happens when we plug them +together with all their channels between + + align:start position:0% +together with all their channels between + + + align:start position:0% +together with all their channels between +them + + align:start position:0% +them + + + align:start position:0% +them +in you know for what corresponding to + + align:start position:0% +in you know for what corresponding to + + + align:start position:0% +in you know for what corresponding to +whatever graph they're in they just have + + align:start position:0% +whatever graph they're in they just have + + + align:start position:0% +whatever graph they're in they just have +channels on the edges + + align:start position:0% +channels on the edges + + + align:start position:0% +channels on the edges +so what's the behavior of this if + + align:start position:0% +so what's the behavior of this if + + + align:start position:0% +so what's the behavior of this if +everybo + + align:start position:0% +everybo + + + align:start position:0% +everybo +all the processes are like the ones i + + align:start position:0% +all the processes are like the ones i + + + align:start position:0% +all the processes are like the ones i +just showed you + + align:start position:0% +just showed you + + + align:start position:0% +just showed you +they wait till they hear some new max + + align:start position:0% +they wait till they hear some new max + + + align:start position:0% +they wait till they hear some new max +and then they send it out + + align:start position:0% + + + + align:start position:0% + +yeah okay um all all across the seats + + align:start position:0% +yeah okay um all all across the seats + + + align:start position:0% +yeah okay um all all across the seats +eventually have a global impact + + align:start position:0% +eventually have a global impact + + + align:start position:0% +eventually have a global impact +yep they'll all eventually get the + + align:start position:0% +yep they'll all eventually get the + + + align:start position:0% +yep they'll all eventually get the +global max they'll keep propagating + + align:start position:0% +global max they'll keep propagating + + + align:start position:0% +global max they'll keep propagating +until everybody receives it so here's a + + align:start position:0% +until everybody receives it so here's a + + + align:start position:0% +until everybody receives it so here's a +animation if everybody starts with the + + align:start position:0% +animation if everybody starts with the + + + align:start position:0% +animation if everybody starts with the +values that are written in these circles + + align:start position:0% +values that are written in these circles + + + align:start position:0% +values that are written in these circles +um okay so now remember before they were + + align:start position:0% +um okay so now remember before they were + + + align:start position:0% +um okay so now remember before they were +all sending it once now + + align:start position:0% +all sending it once now + + + align:start position:0% +all sending it once now +no more let's say the first thing that + + align:start position:0% +no more let's say the first thing that + + + align:start position:0% +no more let's say the first thing that +happens is the process that started with + + align:start position:0% +happens is the process that started with + + + align:start position:0% +happens is the process that started with +five sends its message out + + align:start position:0% +five sends its message out + + + align:start position:0% +five sends its message out +on one of its channels okay so the five + + align:start position:0% +on one of its channels okay so the five + + + align:start position:0% +on one of its channels okay so the five +goes out + + align:start position:0% +goes out + + + align:start position:0% +goes out +the next thing that might happen is the + + align:start position:0% +the next thing that might happen is the + + + align:start position:0% +the next thing that might happen is the +other process with the seven might send + + align:start position:0% +other process with the seven might send + + + align:start position:0% +other process with the seven might send +the seven out on one of its channels + + align:start position:0% +the seven out on one of its channels + + + align:start position:0% +the seven out on one of its channels +and these are three more steps somebody + + align:start position:0% +and these are three more steps somebody + + + align:start position:0% +and these are three more steps somebody +sends a ten somebody sends a seven + + align:start position:0% +sends a ten somebody sends a seven + + + align:start position:0% +sends a ten somebody sends a seven +uh somebody um received a message and + + align:start position:0% +uh somebody um received a message and + + + align:start position:0% +uh somebody um received a message and +updated + + align:start position:0% +updated + + + align:start position:0% +updated +its value as a result and we continue + + align:start position:0% +its value as a result and we continue + + + align:start position:0% +its value as a result and we continue +i'm + + align:start position:0% +i'm + + + align:start position:0% +i'm +depicting several steps at once because + + align:start position:0% +depicting several steps at once because + + + align:start position:0% +depicting several steps at once because +it's boring to really do them one at a + + align:start position:0% +it's boring to really do them one at a + + + align:start position:0% +it's boring to really do them one at a +time but + + align:start position:0% +time but + + + align:start position:0% +time but +the model really says they take steps in + + align:start position:0% +the model really says they take steps in + + + align:start position:0% +the model really says they take steps in +some order + + align:start position:0% +some order + + + align:start position:0% +some order +so everybody's propagating the largest + + align:start position:0% +so everybody's propagating the largest + + + align:start position:0% +so everybody's propagating the largest +thing you've seen + + align:start position:0% +thing you've seen + + + align:start position:0% +thing you've seen +and eventually + + align:start position:0% + + + + align:start position:0% + +you wind up with everybody having the + + align:start position:0% +you wind up with everybody having the + + + align:start position:0% +you wind up with everybody having the +maximum value the 10. + + align:start position:0% +maximum value the 10. + + + align:start position:0% +maximum value the 10. +okay + + align:start position:0% + + + + align:start position:0% + +all right so that's how an asynchronous + + align:start position:0% +all right so that's how an asynchronous + + + align:start position:0% +all right so that's how an asynchronous +system operates + + align:start position:0% +system operates + + + align:start position:0% +system operates +um we can analyze the message complexity + + align:start position:0% +um we can analyze the message complexity + + + align:start position:0% +um we can analyze the message complexity +of this uh the total number of messages + + align:start position:0% +of this uh the total number of messages + + + align:start position:0% +of this uh the total number of messages +sent during the entire execution at + + align:start position:0% +sent during the entire execution at + + + align:start position:0% +sent during the entire execution at +worst + + align:start position:0% +worst + + + align:start position:0% +worst +on every edge you can send the + + align:start position:0% +on every edge you can send the + + + align:start position:0% +on every edge you can send the +successively improved estimates so + + align:start position:0% +successively improved estimates so + + + align:start position:0% +successively improved estimates so +that's again + + align:start position:0% +that's again + + + align:start position:0% +that's again +order n times the number of edges + + align:start position:0% +order n times the number of edges + + + align:start position:0% +order n times the number of edges +time complexity is an issue okay so + + align:start position:0% +time complexity is an issue okay so + + + align:start position:0% +time complexity is an issue okay so +when we had synchronous algorithms we + + align:start position:0% +when we had synchronous algorithms we + + + align:start position:0% +when we had synchronous algorithms we +just counted the number of rounds and + + align:start position:0% +just counted the number of rounds and + + + align:start position:0% +just counted the number of rounds and +that was easy + + align:start position:0% +that was easy + + + align:start position:0% +that was easy +but what do we measure now how do we + + align:start position:0% +but what do we measure now how do we + + + align:start position:0% +but what do we measure now how do we +count the time + + align:start position:0% +count the time + + + align:start position:0% +count the time +when you know you have all these + + align:start position:0% +when you know you have all these + + + align:start position:0% +when you know you have all these +processes and channels taking steps + + align:start position:0% +processes and channels taking steps + + + align:start position:0% +processes and channels taking steps +whenever they want + + align:start position:0% +whenever they want + + + align:start position:0% +whenever they want +yeah so this really isn't obvious + + align:start position:0% +yeah so this really isn't obvious + + + align:start position:0% +yeah so this really isn't obvious +there's a solution that's commonly used + + align:start position:0% +there's a solution that's commonly used + + + align:start position:0% +there's a solution that's commonly used +which is + + align:start position:0% +which is + + + align:start position:0% +which is +okay we're going to use real time + + align:start position:0% +okay we're going to use real time + + + align:start position:0% +okay we're going to use real time +and we're going to make some assumptions + + align:start position:0% +and we're going to make some assumptions + + + align:start position:0% +and we're going to make some assumptions +about + + align:start position:0% +about + + + align:start position:0% +about +um certain basic steps taking at most + + align:start position:0% +um certain basic steps taking at most + + + align:start position:0% +um certain basic steps taking at most +a certain amount of time like + + align:start position:0% +a certain amount of time like + + + align:start position:0% +a certain amount of time like +let's say that local computation time + + align:start position:0% +let's say that local computation time + + + align:start position:0% +let's say that local computation time +for a process to perform + + align:start position:0% +for a process to perform + + + align:start position:0% +for a process to perform +its next step is little l you just give + + align:start position:0% +its next step is little l you just give + + + align:start position:0% +its next step is little l you just give +a + + align:start position:0% +a + + + align:start position:0% +a +a local time bound and then you have d + + align:start position:0% +a local time bound and then you have d + + + align:start position:0% +a local time bound and then you have d +for a channel to deliver + + align:start position:0% +for a channel to deliver + + + align:start position:0% +for a channel to deliver +one message the first message that's + + align:start position:0% +one message the first message that's + + + align:start position:0% +one message the first message that's +currently in the channel + + align:start position:0% +currently in the channel + + + align:start position:0% +currently in the channel +if you have assumptions like that you + + align:start position:0% +if you have assumptions like that you + + + align:start position:0% +if you have assumptions like that you +could use those to infer + + align:start position:0% +could use those to infer + + + align:start position:0% +could use those to infer +a real-time upper bound for solving the + + align:start position:0% +a real-time upper bound for solving the + + + align:start position:0% +a real-time upper bound for solving the +whole problem i mean if you know + + align:start position:0% +whole problem i mean if you know + + + align:start position:0% +whole problem i mean if you know +it takes no longer than d to deliver one + + align:start position:0% +it takes no longer than d to deliver one + + + align:start position:0% +it takes no longer than d to deliver one +message + + align:start position:0% +message + + + align:start position:0% +message +then you can bound how long it takes to + + align:start position:0% +then you can bound how long it takes to + + + align:start position:0% +then you can bound how long it takes to +deliver to empty out a cue + + align:start position:0% +deliver to empty out a cue + + + align:start position:0% +deliver to empty out a cue +a channel and how long it takes for + + align:start position:0% +a channel and how long it takes for + + + align:start position:0% +a channel and how long it takes for +messages to propagate through the + + align:start position:0% +messages to propagate through the + + + align:start position:0% +messages to propagate through the +network + + align:start position:0% +network + + + align:start position:0% +network +okay so this is + + align:start position:0% +okay so this is + + + align:start position:0% +okay so this is +it's tricky but this is uh about the + + align:start position:0% +it's tricky but this is uh about the + + + align:start position:0% +it's tricky but this is uh about the +only thing you can do in a setting where + + align:start position:0% +only thing you can do in a setting where + + + align:start position:0% +only thing you can do in a setting where +you don't actually have rounds to + + align:start position:0% +you don't actually have rounds to + + + align:start position:0% +you don't actually have rounds to +measure + + align:start position:0% +measure + + + align:start position:0% +measure +okay so then for the max system how long + + align:start position:0% +okay so then for the max system how long + + + align:start position:0% +okay so then for the max system how long +does it take well let's just ignore the + + align:start position:0% +does it take well let's just ignore the + + + align:start position:0% +does it take well let's just ignore the +local processing time + + align:start position:0% +local processing time + + + align:start position:0% +local processing time +usually that's assumed to be very small + + align:start position:0% +usually that's assumed to be very small + + + align:start position:0% +usually that's assumed to be very small +so let's say it's zero + + align:start position:0% +so let's say it's zero + + + align:start position:0% +so let's say it's zero +we can get a very simple pessimistic + + align:start position:0% +we can get a very simple pessimistic + + + align:start position:0% +we can get a very simple pessimistic +really + + align:start position:0% +really + + + align:start position:0% +really +upper bound that says the real time + + align:start position:0% +upper bound that says the real time + + + align:start position:0% +upper bound that says the real time +for finishing the whole thing is the + + align:start position:0% +for finishing the whole thing is the + + + align:start position:0% +for finishing the whole thing is the +order of the diameter of the network + + align:start position:0% +order of the diameter of the network + + + align:start position:0% +order of the diameter of the network +times the number of nodes times + + align:start position:0% +times the number of nodes times + + + align:start position:0% +times the number of nodes times +little d is the amount of time for a + + align:start position:0% +little d is the amount of time for a + + + align:start position:0% +little d is the amount of time for a +message queue to deliver its first + + align:start position:0% +message queue to deliver its first + + + align:start position:0% +message queue to deliver its first +message + + align:start position:0% + + + + align:start position:0% + +okay so as a naive way of analyzing this + + align:start position:0% +okay so as a naive way of analyzing this + + + align:start position:0% +okay so as a naive way of analyzing this +you just consider how long it takes for + + align:start position:0% +you just consider how long it takes for + + + align:start position:0% +you just consider how long it takes for +the max to reach some particular vertex + + align:start position:0% +the max to reach some particular vertex + + + align:start position:0% +the max to reach some particular vertex +u along the shortest path well it has to + + align:start position:0% +u along the shortest path well it has to + + + align:start position:0% +u along the shortest path well it has to +go through all the + + align:start position:0% +go through all the + + + align:start position:0% +go through all the +hops on the path so + + align:start position:0% +hops on the path so + + + align:start position:0% +hops on the path so +that would be the diameter and + + align:start position:0% +that would be the diameter and + + + align:start position:0% +that would be the diameter and +how long does it have to wait in each + + align:start position:0% +how long does it have to wait in each + + + align:start position:0% +how long does it have to wait in each +channel before it gets to + + align:start position:0% +channel before it gets to + + + align:start position:0% +channel before it gets to +move another hop well it might be at the + + align:start position:0% +move another hop well it might be at the + + + align:start position:0% +move another hop well it might be at the +end of a q + + align:start position:0% +end of a q + + + align:start position:0% +end of a q +how big could the q be well at worst end + + align:start position:0% +how big could the q be well at worst end + + + align:start position:0% +how big could the q be well at worst end +for the improved estimates + + align:start position:0% +for the improved estimates + + + align:start position:0% +for the improved estimates +so let's say it's n times the delivery + + align:start position:0% +so let's say it's n times the delivery + + + align:start position:0% +so let's say it's n times the delivery +time on the channel + + align:start position:0% +time on the channel + + + align:start position:0% +time on the channel +just to traverse one channel what i'm + + align:start position:0% +just to traverse one channel what i'm + + + align:start position:0% +just to traverse one channel what i'm +doing is modeling + + align:start position:0% +doing is modeling + + + align:start position:0% +doing is modeling +possible congestion on the queue to see + + align:start position:0% +possible congestion on the queue to see + + + align:start position:0% +possible congestion on the queue to see +how long it takes for + + align:start position:0% +how long it takes for + + + align:start position:0% +how long it takes for +for a message to traverse one channel + + align:start position:0% +for a message to traverse one channel + + + align:start position:0% +for a message to traverse one channel +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +are we just assuming that processes + + align:start position:0% +are we just assuming that processes + + + align:start position:0% +are we just assuming that processes +process things and messages are + + align:start position:0% +process things and messages are + + + align:start position:0% +process things and messages are +delivered as soon as they can possibly + + align:start position:0% +delivered as soon as they can possibly + + + align:start position:0% +delivered as soon as they can possibly +happen + + align:start position:0% +happen + + + align:start position:0% +happen +um good yeah so and we we normally have + + align:start position:0% +um good yeah so and we we normally have + + + align:start position:0% +um good yeah so and we we normally have +i'm sort of skipping over some things in + + align:start position:0% +i'm sort of skipping over some things in + + + align:start position:0% +i'm sort of skipping over some things in +the model but you have + + align:start position:0% +the model but you have + + + align:start position:0% +the model but you have +a um a liveness assumption that says + + align:start position:0% +a um a liveness assumption that says + + + align:start position:0% +a um a liveness assumption that says +that a process keeps taking steps + + align:start position:0% +that a process keeps taking steps + + + align:start position:0% +that a process keeps taking steps +as long as it has anything to do and so + + align:start position:0% +as long as it has anything to do and so + + + align:start position:0% +as long as it has anything to do and so +we would be putting time bounds + + align:start position:0% +we would be putting time bounds + + + align:start position:0% +we would be putting time bounds +on how long it takes between those steps + + align:start position:0% +on how long it takes between those steps + + + align:start position:0% +on how long it takes between those steps +that'd be the local processing + + align:start position:0% +that'd be the local processing + + + align:start position:0% +that'd be the local processing +time here i'm saying that zero so we can + + align:start position:0% +time here i'm saying that zero so we can + + + align:start position:0% +time here i'm saying that zero so we can +do that wouldn't you be able to like + + align:start position:0% +do that wouldn't you be able to like + + + align:start position:0% +do that wouldn't you be able to like +get some amount of information about + + align:start position:0% +get some amount of information about + + + align:start position:0% +get some amount of information about +what were things happening + + align:start position:0% +what were things happening + + + align:start position:0% +what were things happening +ah okay so here's this is a very subtle + + align:start position:0% +ah okay so here's this is a very subtle + + + align:start position:0% +ah okay so here's this is a very subtle +point + + align:start position:0% +point + + + align:start position:0% +point +so what you think is that if i'm making + + align:start position:0% +so what you think is that if i'm making + + + align:start position:0% +so what you think is that if i'm making +all these timing assumptions the + + align:start position:0% +all these timing assumptions the + + + align:start position:0% +all these timing assumptions the +processes should be able to figure that + + align:start position:0% +processes should be able to figure that + + + align:start position:0% +processes should be able to figure that +out + + align:start position:0% +out + + + align:start position:0% +out +but actually you can't figure anything + + align:start position:0% +but actually you can't figure anything + + + align:start position:0% +but actually you can't figure anything +out just based on + + align:start position:0% +out just based on + + + align:start position:0% +out just based on +these assumptions about these upper + + align:start position:0% +these assumptions about these upper + + + align:start position:0% +these assumptions about these upper +bounds + + align:start position:0% +bounds + + + align:start position:0% +bounds +putting upper bounds on the time between + + align:start position:0% +putting upper bounds on the time between + + + align:start position:0% +putting upper bounds on the time between +steps does not in any way restrict the + + align:start position:0% +steps does not in any way restrict the + + + align:start position:0% +steps does not in any way restrict the +orderings + + align:start position:0% +orderings + + + align:start position:0% +orderings +you still have all the same possible + + align:start position:0% +you still have all the same possible + + + align:start position:0% +you still have all the same possible +orderings of steps + + align:start position:0% +orderings of steps + + + align:start position:0% +orderings of steps +so nobody can see anything different + + align:start position:0% +so nobody can see anything different + + + align:start position:0% +so nobody can see anything different +these times are not visible in any sense + + align:start position:0% +these times are not visible in any sense + + + align:start position:0% +these times are not visible in any sense +they're not marked anywhere for the + + align:start position:0% +they're not marked anywhere for the + + + align:start position:0% +they're not marked anywhere for the +processes to read + + align:start position:0% +processes to read + + + align:start position:0% +processes to read +they're just something that we're using + + align:start position:0% +they're just something that we're using + + + align:start position:0% +they're just something that we're using +to evaluate the cost the time + + align:start position:0% +to evaluate the cost the time + + + align:start position:0% +to evaluate the cost the time +cost of the execution + + align:start position:0% +cost of the execution + + + align:start position:0% +cost of the execution +and you're not um you're not restricting + + align:start position:0% +and you're not um you're not restricting + + + align:start position:0% +and you're not um you're not restricting +the execution by putting just + + align:start position:0% +the execution by putting just + + + align:start position:0% +the execution by putting just +upper bounds on the time if you were + + align:start position:0% +upper bounds on the time if you were + + + align:start position:0% +upper bounds on the time if you were +restricting the execution like you had + + align:start position:0% +restricting the execution like you had + + + align:start position:0% +restricting the execution like you had +upper bounds and lower bounds on the + + align:start position:0% +upper bounds and lower bounds on the + + + align:start position:0% +upper bounds and lower bounds on the +time + + align:start position:0% +time + + + align:start position:0% +time +then the processes might know a lot more + + align:start position:0% +then the processes might know a lot more + + + align:start position:0% +then the processes might know a lot more +they might in fact be acting more like a + + align:start position:0% +they might in fact be acting more like a + + + align:start position:0% +they might in fact be acting more like a +synchronous + + align:start position:0% +synchronous + + + align:start position:0% +synchronous +system okay so these are times that are + + align:start position:0% +system okay so these are times that are + + + align:start position:0% +system okay so these are times that are +just used for analyzing complexity + + align:start position:0% +just used for analyzing complexity + + + align:start position:0% +just used for analyzing complexity +they're not anything known to the + + align:start position:0% +they're not anything known to the + + + align:start position:0% +they're not anything known to the +processes in the system + + align:start position:0% +processes in the system + + + align:start position:0% +processes in the system +okay all right so now let's revisit the + + align:start position:0% +okay all right so now let's revisit the + + + align:start position:0% +okay all right so now let's revisit the +breadth first spanning tree problem + + align:start position:0% +breadth first spanning tree problem + + + align:start position:0% +breadth first spanning tree problem +we want to now compute a breadth first + + align:start position:0% +we want to now compute a breadth first + + + align:start position:0% +we want to now compute a breadth first +spanning tree in an asynchronous network + + align:start position:0% +spanning tree in an asynchronous network + + + align:start position:0% +spanning tree in an asynchronous network +connected graph distinguished root + + align:start position:0% +connected graph distinguished root + + + align:start position:0% +connected graph distinguished root +vertex processes have no knowledge of + + align:start position:0% +vertex processes have no knowledge of + + + align:start position:0% +vertex processes have no knowledge of +the graph + + align:start position:0% +the graph + + + align:start position:0% +the graph +they have uids all this is the same as + + align:start position:0% +they have uids all this is the same as + + + align:start position:0% +they have uids all this is the same as +before + + align:start position:0% +before + + + align:start position:0% +before +in the synchronous case everybody's + + align:start position:0% +in the synchronous case everybody's + + + align:start position:0% +in the synchronous case everybody's +supposed to output + + align:start position:0% +supposed to output + + + align:start position:0% +supposed to output +its parent information when it's done + + align:start position:0% +its parent information when it's done + + + align:start position:0% +its parent information when it's done +okay so here's + + align:start position:0% +okay so here's + + + align:start position:0% +okay so here's +here's an idea suppose we just take that + + align:start position:0% +here's an idea suppose we just take that + + + align:start position:0% +here's an idea suppose we just take that +nice simple + + align:start position:0% +nice simple + + + align:start position:0% +nice simple +synchronous algorithm that i reviewed at + + align:start position:0% +synchronous algorithm that i reviewed at + + + align:start position:0% +synchronous algorithm that i reviewed at +the beginning of the hour + + align:start position:0% +the beginning of the hour + + + align:start position:0% +the beginning of the hour +where everybody just sends a search + + align:start position:0% +where everybody just sends a search + + + align:start position:0% +where everybody just sends a search +message as soon as they get it and they + + align:start position:0% +message as soon as they get it and they + + + align:start position:0% +message as soon as they get it and they +just adopt the first parent they see + + align:start position:0% +just adopt the first parent they see + + + align:start position:0% +just adopt the first parent they see +okay what happens if i run that + + align:start position:0% +okay what happens if i run that + + + align:start position:0% +okay what happens if i run that +asynchronously + + align:start position:0% + + + + align:start position:0% + +i just send it and i get a search + + align:start position:0% +i just send it and i get a search + + + align:start position:0% +i just send it and i get a search +message then i send it out to my parents + + align:start position:0% +message then i send it out to my parents + + + align:start position:0% +message then i send it out to my parents +whenever and everybody's doing this + + align:start position:0% +whenever and everybody's doing this + + + align:start position:0% +whenever and everybody's doing this +whatever they get whenever they get + + align:start position:0% +whatever they get whenever they get + + + align:start position:0% +whatever they get whenever they get +their first search message they decide + + align:start position:0% +their first search message they decide + + + align:start position:0% +their first search message they decide +the sender is its parent + + align:start position:0% + + + + align:start position:0% + +keeps yeah not moving not obeying the + + align:start position:0% +keeps yeah not moving not obeying the + + + align:start position:0% +keeps yeah not moving not obeying the +fanning property of the vfs + + align:start position:0% +fanning property of the vfs + + + align:start position:0% +fanning property of the vfs +yeah it could be that because we don't + + align:start position:0% +yeah it could be that because we don't + + + align:start position:0% +yeah it could be that because we don't +have any restriction on how + + align:start position:0% +have any restriction on how + + + align:start position:0% +have any restriction on how +fast the messages might be sent and + + align:start position:0% +fast the messages might be sent and + + + align:start position:0% +fast the messages might be sent and +the order of steps it could be that some + + align:start position:0% +the order of steps it could be that some + + + align:start position:0% +the order of steps it could be that some +messages + + align:start position:0% +messages + + + align:start position:0% +messages +get sent very quickly on some long path + + align:start position:0% +get sent very quickly on some long path + + + align:start position:0% +get sent very quickly on some long path +so someone + + align:start position:0% +so someone + + + align:start position:0% +so someone +sitting at the far end of the network + + align:start position:0% +sitting at the far end of the network + + + align:start position:0% +sitting at the far end of the network +might get a message first on a long path + + align:start position:0% +might get a message first on a long path + + + align:start position:0% +might get a message first on a long path +and later on a short path + + align:start position:0% +and later on a short path + + + align:start position:0% +and later on a short path +and the first one it gets if it decides + + align:start position:0% +and the first one it gets if it decides + + + align:start position:0% +and the first one it gets if it decides +that's its parent + + align:start position:0% +that's its parent + + + align:start position:0% +that's its parent +then it's stuck this is not an algorithm + + align:start position:0% +then it's stuck this is not an algorithm + + + align:start position:0% +then it's stuck this is not an algorithm +that makes corrections + + align:start position:0% +that makes corrections + + + align:start position:0% +that makes corrections +okay so all right + + align:start position:0% +okay so all right + + + align:start position:0% +okay so all right +well we before we had a little bit of + + align:start position:0% +well we before we had a little bit of + + + align:start position:0% +well we before we had a little bit of +non-determinism when we had this + + align:start position:0% +non-determinism when we had this + + + align:start position:0% +non-determinism when we had this +algorithm + + align:start position:0% +algorithm + + + align:start position:0% +algorithm +in the synchronous case because we could + + align:start position:0% +in the synchronous case because we could + + + align:start position:0% +in the synchronous case because we could +have two + + align:start position:0% +have two + + + align:start position:0% +have two +messages arriving at once and you have + + align:start position:0% +messages arriving at once and you have + + + align:start position:0% +messages arriving at once and you have +to pick one to be your parent + + align:start position:0% +to pick one to be your parent + + + align:start position:0% +to pick one to be your parent +now that doesn't happen because you only + + align:start position:0% +now that doesn't happen because you only + + + align:start position:0% +now that doesn't happen because you only +get one message at a time + + align:start position:0% +get one message at a time + + + align:start position:0% +get one message at a time +but you have a lot more non-determinism + + align:start position:0% +but you have a lot more non-determinism + + + align:start position:0% +but you have a lot more non-determinism +now okay now you have + + align:start position:0% +now okay now you have + + + align:start position:0% +now okay now you have +all this non-determinism from the order + + align:start position:0% +all this non-determinism from the order + + + align:start position:0% +all this non-determinism from the order +in which the messages get + + align:start position:0% +in which the messages get + + + align:start position:0% +in which the messages get +sent and processes take their steps so + + align:start position:0% +sent and processes take their steps so + + + align:start position:0% +sent and processes take their steps so +there's plenty of non-determinism and + + align:start position:0% +there's plenty of non-determinism and + + + align:start position:0% +there's plenty of non-determinism and +remember the way we treat + + align:start position:0% +remember the way we treat + + + align:start position:0% +remember the way we treat +non-determinism + + align:start position:0% +non-determinism + + + align:start position:0% +non-determinism +for distributed algorithms is it's + + align:start position:0% +for distributed algorithms is it's + + + align:start position:0% +for distributed algorithms is it's +supposed to work regardless of how those + + align:start position:0% +supposed to work regardless of how those + + + align:start position:0% +supposed to work regardless of how those +non-deterministic choices get made + + align:start position:0% +non-deterministic choices get made + + + align:start position:0% +non-deterministic choices get made +okay so how would we describe i'll just + + align:start position:0% +okay so how would we describe i'll just + + + align:start position:0% +okay so how would we describe i'll just +write some pseudo code here for + + align:start position:0% +write some pseudo code here for + + + align:start position:0% +write some pseudo code here for +a process that's just mimicking the + + align:start position:0% +a process that's just mimicking the + + + align:start position:0% +a process that's just mimicking the +trivial algorithm + + align:start position:0% +trivial algorithm + + + align:start position:0% +trivial algorithm +it can receive a search message that's + + align:start position:0% +it can receive a search message that's + + + align:start position:0% +it can receive a search message that's +the inputs and it can + + align:start position:0% +the inputs and it can + + + align:start position:0% +the inputs and it can +send a search message as its output + + align:start position:0% +send a search message as its output + + + align:start position:0% +send a search message as its output +it can also output parent when it's + + align:start position:0% +it can also output parent when it's + + + align:start position:0% +it can also output parent when it's +ready to do that + + align:start position:0% +ready to do that + + + align:start position:0% +ready to do that +okay so what does it have to keep track + + align:start position:0% +okay so what does it have to keep track + + + align:start position:0% +okay so what does it have to keep track +of well keeps track of its + + align:start position:0% +of well keeps track of its + + + align:start position:0% +of well keeps track of its +its parent keeps track of whether it's + + align:start position:0% +its parent keeps track of whether it's + + + align:start position:0% +its parent keeps track of whether it's +reported its parent + + align:start position:0% +reported its parent + + + align:start position:0% +reported its parent +and it has some send buffers with + + align:start position:0% +and it has some send buffers with + + + align:start position:0% +and it has some send buffers with +messages + + align:start position:0% +messages + + + align:start position:0% +messages +it's ready to send to its neighbors + + align:start position:0% +it's ready to send to its neighbors + + + align:start position:0% +it's ready to send to its neighbors +could be search messages or nothing + + align:start position:0% + + + + align:start position:0% + +this bottom symbol is just a placeholder + + align:start position:0% +this bottom symbol is just a placeholder + + + align:start position:0% +this bottom symbol is just a placeholder +symbol + + align:start position:0% + + + + align:start position:0% + +okay so what happens when + + align:start position:0% +okay so what happens when + + + align:start position:0% +okay so what happens when +the process receives a search message + + align:start position:0% +the process receives a search message + + + align:start position:0% +the process receives a search message +just following the simple algorithm + + align:start position:0% +just following the simple algorithm + + + align:start position:0% +just following the simple algorithm +well if it doesn't have a parent yet + + align:start position:0% +well if it doesn't have a parent yet + + + align:start position:0% +well if it doesn't have a parent yet +then it sets its parent to be the sender + + align:start position:0% +then it sets its parent to be the sender + + + align:start position:0% +then it sets its parent to be the sender +of that search message + + align:start position:0% +of that search message + + + align:start position:0% +of that search message +and it gets ready to send the search + + align:start position:0% +and it gets ready to send the search + + + align:start position:0% +and it gets ready to send the search +message to all of its neighbors + + align:start position:0% +message to all of its neighbors + + + align:start position:0% +message to all of its neighbors +so that's really the heart of the + + align:start position:0% +so that's really the heart of the + + + align:start position:0% +so that's really the heart of the +algorithm that you saw + + align:start position:0% +algorithm that you saw + + + align:start position:0% +algorithm that you saw +for the simple algorithm for the the + + align:start position:0% +for the simple algorithm for the the + + + align:start position:0% +for the simple algorithm for the the +synchronous case so that's the same code + + align:start position:0% +synchronous case so that's the same code + + + align:start position:0% +synchronous case so that's the same code +the rest of the code is it just sends + + align:start position:0% +the rest of the code is it just sends + + + align:start position:0% +the rest of the code is it just sends +the search messages out when it's got + + align:start position:0% +the search messages out when it's got + + + align:start position:0% +the search messages out when it's got +them in + + align:start position:0% +them in + + + align:start position:0% +them in +the send buffers and it can announce its + + align:start position:0% +the send buffers and it can announce its + + + align:start position:0% +the send buffers and it can announce its +parent once the parent is set + + align:start position:0% +parent once the parent is set + + + align:start position:0% +parent once the parent is set +and uh then it doesn't this flag just + + align:start position:0% +and uh then it doesn't this flag just + + + align:start position:0% +and uh then it doesn't this flag just +means it doesn't keep announcing it over + + align:start position:0% +means it doesn't keep announcing it over + + + align:start position:0% +means it doesn't keep announcing it over +and over again + + align:start position:0% +and over again + + + align:start position:0% +and over again +okay so it makes sense that this + + align:start position:0% +okay so it makes sense that this + + + align:start position:0% +okay so it makes sense that this +describes that simple algorithm + + align:start position:0% +describes that simple algorithm + + + align:start position:0% +describes that simple algorithm +it's pretty concise just what does it do + + align:start position:0% +it's pretty concise just what does it do + + + align:start position:0% +it's pretty concise just what does it do +in all these different steps + + align:start position:0% + + + + align:start position:0% + +okay okay so now if you run this + + align:start position:0% +okay okay so now if you run this + + + align:start position:0% +okay okay so now if you run this +asynchronously + + align:start position:0% +asynchronously + + + align:start position:0% +asynchronously +as you already noted it isn't going to + + align:start position:0% +as you already noted it isn't going to + + + align:start position:0% +as you already noted it isn't going to +necessarily work right + + align:start position:0% +necessarily work right + + + align:start position:0% +necessarily work right +so you can have this guy sending search + + align:start position:0% +so you can have this guy sending search + + + align:start position:0% +so you can have this guy sending search +messages + + align:start position:0% +messages + + + align:start position:0% +messages +but some are going to arrive faster than + + align:start position:0% +but some are going to arrive faster than + + + align:start position:0% +but some are going to arrive faster than +others + + align:start position:0% +others + + + align:start position:0% +others +and you see you can have the search + + align:start position:0% +and you see you can have the search + + + align:start position:0% +and you see you can have the search +messages creeping around + + align:start position:0% +messages creeping around + + + align:start position:0% +messages creeping around +in an indirect path which causes a + + align:start position:0% +in an indirect path which causes a + + + align:start position:0% +in an indirect path which causes a +spanning tree like this one to be + + align:start position:0% +spanning tree like this one to be + + + align:start position:0% +spanning tree like this one to be +created + + align:start position:0% +created + + + align:start position:0% +created +which is definitely not a breadth for a + + align:start position:0% +which is definitely not a breadth for a + + + align:start position:0% +which is definitely not a breadth for a +spanning tree the bread first tree is + + align:start position:0% +spanning tree the bread first tree is + + + align:start position:0% +spanning tree the bread first tree is +this one + + align:start position:0% +this one + + + align:start position:0% +this one +a breath first tree okay so you have + + align:start position:0% +a breath first tree okay so you have + + + align:start position:0% +a breath first tree okay so you have +these roundabout pads + + align:start position:0% +these roundabout pads + + + align:start position:0% +these roundabout pads +okay so this doesn't work so what do we + + align:start position:0% +okay so this doesn't work so what do we + + + align:start position:0% +okay so this doesn't work so what do we +do + + align:start position:0% + + + + align:start position:0% + +you're going to try to synchronize them + + align:start position:0% + + + + align:start position:0% + +basically + + align:start position:0% +basically + + + align:start position:0% +basically +that is related to a homework question + + align:start position:0% +that is related to a homework question + + + align:start position:0% +that is related to a homework question +this week very good + + align:start position:0% +this week very good + + + align:start position:0% +this week very good +we're going to do something different + + align:start position:0% +we're going to do something different + + + align:start position:0% +we're going to do something different +other suggestions + + align:start position:0% +other suggestions + + + align:start position:0% +other suggestions +yeah we could like keep a variable + + align:start position:0% +yeah we could like keep a variable + + + align:start position:0% +yeah we could like keep a variable +in each process that so like you can do + + align:start position:0% +in each process that so like you can do + + + align:start position:0% +in each process that so like you can do +something like down and forward + + align:start position:0% +something like down and forward + + + align:start position:0% +something like down and forward +yeah so you can do what we did for + + align:start position:0% +yeah so you can do what we did for + + + align:start position:0% +yeah so you can do what we did for +bellman ford but now the setting is + + align:start position:0% +bellman ford but now the setting is + + + align:start position:0% +bellman ford but now the setting is +completely different we did it for + + align:start position:0% +completely different we did it for + + + align:start position:0% +completely different we did it for +bellman ford + + align:start position:0% +bellman ford + + + align:start position:0% +bellman ford +when it was synchronous and we had + + align:start position:0% +when it was synchronous and we had + + + align:start position:0% +when it was synchronous and we had +weights now it's asynchronous and there + + align:start position:0% +weights now it's asynchronous and there + + + align:start position:0% +weights now it's asynchronous and there +are no weights + + align:start position:0% +are no weights + + + align:start position:0% +are no weights +okay so oh there's some remarks on + + align:start position:0% +okay so oh there's some remarks on + + + align:start position:0% +okay so oh there's some remarks on +a couple of slides here so this is just + + align:start position:0% +a couple of slides here so this is just + + + align:start position:0% +a couple of slides here so this is just +belaboring the point that the paths that + + align:start position:0% +belaboring the point that the paths that + + + align:start position:0% +belaboring the point that the paths that +you get by this algorithm can be longer + + align:start position:0% +you get by this algorithm can be longer + + + align:start position:0% +you get by this algorithm can be longer +than the shortest paths + + align:start position:0% +than the shortest paths + + + align:start position:0% +than the shortest paths +and yeah you can analyze the + + align:start position:0% +and yeah you can analyze the + + + align:start position:0% +and yeah you can analyze the +message and time complexity + + align:start position:0% + + + + align:start position:0% + +complexity + + align:start position:0% + + + + align:start position:0% + +okay so the complexity here is order of + + align:start position:0% +okay so the complexity here is order of + + + align:start position:0% +okay so the complexity here is order of +the diameter + + align:start position:0% +the diameter + + + align:start position:0% +the diameter +times the message delay on one uh + + align:start position:0% +times the message delay on one uh + + + align:start position:0% +times the message delay on one uh +link and um + + align:start position:0% +link and um + + + align:start position:0% +link and um +why is it diameter even though the path + + align:start position:0% +why is it diameter even though the path + + + align:start position:0% +why is it diameter even though the path +some paths may be very long + + align:start position:0% +some paths may be very long + + + align:start position:0% +some paths may be very long +this is a real-time upper bound that + + align:start position:0% +this is a real-time upper bound that + + + align:start position:0% +this is a real-time upper bound that +is that depends on the the actual + + align:start position:0% +is that depends on the the actual + + + align:start position:0% +is that depends on the the actual +diameter of the graph + + align:start position:0% +diameter of the graph + + + align:start position:0% +diameter of the graph +not on the total number of nodes + + align:start position:0% + + + + align:start position:0% + +why would the an upper bound on the + + align:start position:0% +why would the an upper bound on the + + + align:start position:0% +why would the an upper bound on the +running time for this simple algorithm + + align:start position:0% +running time for this simple algorithm + + + align:start position:0% +running time for this simple algorithm +depend + + align:start position:0% +depend + + + align:start position:0% +depend +on the diameter + + align:start position:0% + + + + align:start position:0% + +yeah because you only have a longer + + align:start position:0% +yeah because you only have a longer + + + align:start position:0% +yeah because you only have a longer +packet that's faster than that + + align:start position:0% +packet that's faster than that + + + align:start position:0% +packet that's faster than that +exactly the way we're modeling it it's a + + align:start position:0% +exactly the way we're modeling it it's a + + + align:start position:0% +exactly the way we're modeling it it's a +little strange maybe but we're saying + + align:start position:0% +little strange maybe but we're saying + + + align:start position:0% +little strange maybe but we're saying +that + + align:start position:0% +that + + + align:start position:0% +that +something can travel on a long path only + + align:start position:0% +something can travel on a long path only + + + align:start position:0% +something can travel on a long path only +if it's going very fast + + align:start position:0% +if it's going very fast + + + align:start position:0% +if it's going very fast +but the actual uh shortest paths still + + align:start position:0% +but the actual uh shortest paths still + + + align:start position:0% +but the actual uh shortest paths still +move along at worst at the you know + + align:start position:0% +move along at worst at the you know + + + align:start position:0% +move along at worst at the you know +d time per hop so at worst + + align:start position:0% +d time per hop so at worst + + + align:start position:0% +d time per hop so at worst +the shortest path information would get + + align:start position:0% +the shortest path information would get + + + align:start position:0% +the shortest path information would get +there within time d + + align:start position:0% +there within time d + + + align:start position:0% +there within time d +so something's going to get there within + + align:start position:0% +so something's going to get there within + + + align:start position:0% +so something's going to get there within +time d even though something else might + + align:start position:0% +time d even though something else might + + + align:start position:0% +time d even though something else might +get there faster + + align:start position:0% +get there faster + + + align:start position:0% +get there faster +okay all right + + align:start position:0% +okay all right + + + align:start position:0% +okay all right +so yeah so we can set up the child + + align:start position:0% +so yeah so we can set up the child + + + align:start position:0% +so yeah so we can set up the child +pointers and + + align:start position:0% +pointers and + + + align:start position:0% +pointers and +um we can do termination using converge + + align:start position:0% +um we can do termination using converge + + + align:start position:0% +um we can do termination using converge +cast + + align:start position:0% +cast + + + align:start position:0% +cast +it's just one tree there's nothing + + align:start position:0% +it's just one tree there's nothing + + + align:start position:0% +it's just one tree there's nothing +changing here + + align:start position:0% +changing here + + + align:start position:0% +changing here +okay and application same as before okay + + align:start position:0% +okay and application same as before okay + + + align:start position:0% +okay and application same as before okay +but that didn't work so we're going to + + align:start position:0% +but that didn't work so we're going to + + + align:start position:0% +but that didn't work so we're going to +back to the point we were talking about + + align:start position:0% +back to the point we were talking about + + + align:start position:0% +back to the point we were talking about +a minute ago we're going to use a + + align:start position:0% +a minute ago we're going to use a + + + align:start position:0% +a minute ago we're going to use a +relaxation algorithm like bellman ford + + align:start position:0% +relaxation algorithm like bellman ford + + + align:start position:0% +relaxation algorithm like bellman ford +so in the synchronous case we corrected + + align:start position:0% +so in the synchronous case we corrected + + + align:start position:0% +so in the synchronous case we corrected +for pads that had many hops but low + + align:start position:0% +for pads that had many hops but low + + + align:start position:0% +for pads that had many hops but low +weight + + align:start position:0% +weight + + + align:start position:0% +weight +but now we're going to correct for the + + align:start position:0% +but now we're going to correct for the + + + align:start position:0% +but now we're going to correct for the +asynchrony errors + + align:start position:0% +asynchrony errors + + + align:start position:0% +asynchrony errors +all the errors that you get because of + + align:start position:0% +all the errors that you get because of + + + align:start position:0% +all the errors that you get because of +things traveling fast on long paths + + align:start position:0% +things traveling fast on long paths + + + align:start position:0% +things traveling fast on long paths +we're going to correct for those using + + align:start position:0% +we're going to correct for those using + + + align:start position:0% +we're going to correct for those using +the same strategy + + align:start position:0% +the same strategy + + + align:start position:0% +the same strategy +okay so everybody is going to keep track + + align:start position:0% +okay so everybody is going to keep track + + + align:start position:0% +okay so everybody is going to keep track +of the hop distance + + align:start position:0% +of the hop distance + + + align:start position:0% +of the hop distance +no weights now just the hop distance and + + align:start position:0% +no weights now just the hop distance and + + + align:start position:0% +no weights now just the hop distance and +they will change the parent when they + + align:start position:0% +they will change the parent when they + + + align:start position:0% +they will change the parent when they +learn of a shorter path + + align:start position:0% +learn of a shorter path + + + align:start position:0% +learn of a shorter path +okay and then they will propagate the + + align:start position:0% +okay and then they will propagate the + + + align:start position:0% +okay and then they will propagate the +improved distance so it's exactly like + + align:start position:0% +improved distance so it's exactly like + + + align:start position:0% +improved distance so it's exactly like +bellman ford + + align:start position:0% +bellman ford + + + align:start position:0% +bellman ford +and eventually this will stabilize to an + + align:start position:0% +and eventually this will stabilize to an + + + align:start position:0% +and eventually this will stabilize to an +actual breadth first spanning tree + + align:start position:0% +actual breadth first spanning tree + + + align:start position:0% +actual breadth first spanning tree +okay so here's a description of this new + + align:start position:0% +okay so here's a description of this new + + + align:start position:0% +okay so here's a description of this new +algorithm + + align:start position:0% +algorithm + + + align:start position:0% +algorithm +everybody keeps track of their parent + + align:start position:0% +everybody keeps track of their parent + + + align:start position:0% +everybody keeps track of their parent +and now they keep track of their hop + + align:start position:0% +and now they keep track of their hop + + + align:start position:0% +and now they keep track of their hop +distance + + align:start position:0% +distance + + + align:start position:0% +distance +and they have their channels okay so + + align:start position:0% +and they have their channels okay so + + + align:start position:0% +and they have their channels okay so +here's the key when you get + + align:start position:0% +here's the key when you get + + + align:start position:0% +here's the key when you get +new information you receive some new + + align:start position:0% +new information you receive some new + + + align:start position:0% +new information you receive some new +information this m + + align:start position:0% +information this m + + + align:start position:0% +information this m +is a number of hops that your neighbor + + align:start position:0% +is a number of hops that your neighbor + + + align:start position:0% +is a number of hops that your neighbor +is telling you + + align:start position:0% +is telling you + + + align:start position:0% +is telling you +well if m plus one which would be your + + align:start position:0% +well if m plus one which would be your + + + align:start position:0% +well if m plus one which would be your +new estimate for a number of hops if + + align:start position:0% +new estimate for a number of hops if + + + align:start position:0% +new estimate for a number of hops if +that's better + + align:start position:0% +that's better + + + align:start position:0% +that's better +than what you already have then you just + + align:start position:0% +than what you already have then you just + + + align:start position:0% +than what you already have then you just +replace your estimate by this + + align:start position:0% +replace your estimate by this + + + align:start position:0% +replace your estimate by this +new number of hops and you + + align:start position:0% +new number of hops and you + + + align:start position:0% +new number of hops and you +set your you know to a new parent you + + align:start position:0% +set your you know to a new parent you + + + align:start position:0% +set your you know to a new parent you +set your parent pointer to the + + align:start position:0% +set your parent pointer to the + + + align:start position:0% +set your parent pointer to the +the sender and you propagate this + + align:start position:0% +the sender and you propagate this + + + align:start position:0% +the sender and you propagate this +information + + align:start position:0% +information + + + align:start position:0% +information +so it's exactly the same as what we had + + align:start position:0% +so it's exactly the same as what we had + + + align:start position:0% +so it's exactly the same as what we had +before but now we're correcting + + align:start position:0% +before but now we're correcting + + + align:start position:0% +before but now we're correcting +for the asynchrony + + align:start position:0% +for the asynchrony + + + align:start position:0% +for the asynchrony +we get shorter hop paths later make + + align:start position:0% +we get shorter hop paths later make + + + align:start position:0% +we get shorter hop paths later make +sense + + align:start position:0% +sense + + + align:start position:0% +sense +okay so and the rest of this is just you + + align:start position:0% +okay so and the rest of this is just you + + + align:start position:0% +okay so and the rest of this is just you +send the message okay and notice we + + align:start position:0% +send the message okay and notice we + + + align:start position:0% +send the message okay and notice we +don't have any terminating actions why + + align:start position:0% +don't have any terminating actions why + + + align:start position:0% +don't have any terminating actions why +because we have the same problem that we + + align:start position:0% +because we have the same problem that we + + + align:start position:0% +because we have the same problem that we +had before + + align:start position:0% +had before + + + align:start position:0% +had before +with having processes no know when + + align:start position:0% +with having processes no know when + + + align:start position:0% +with having processes no know when +they're done + + align:start position:0% +they're done + + + align:start position:0% +they're done +if you keep get getting corrections how + + align:start position:0% +if you keep get getting corrections how + + + align:start position:0% +if you keep get getting corrections how +do you know when you're finished + + align:start position:0% +do you know when you're finished + + + align:start position:0% +do you know when you're finished +and how do you know this is going to + + align:start position:0% +and how do you know this is going to + + + align:start position:0% +and how do you know this is going to +work in the synchronous case + + align:start position:0% +work in the synchronous case + + + align:start position:0% +work in the synchronous case +we could get an exact characterization + + align:start position:0% +we could get an exact characterization + + + align:start position:0% +we could get an exact characterization +of of + + align:start position:0% +of of + + + align:start position:0% +of of +what exactly the situation is after any + + align:start position:0% +what exactly the situation is after any + + + align:start position:0% +what exactly the situation is after any +number + + align:start position:0% +number + + + align:start position:0% +number +of rounds and we can't do that now + + align:start position:0% +of rounds and we can't do that now + + + align:start position:0% +of rounds and we can't do that now +because things can happen in so many + + align:start position:0% +because things can happen in so many + + + align:start position:0% +because things can happen in so many +orders so we we have to instead + + align:start position:0% +orders so we we have to instead + + + align:start position:0% +orders so we we have to instead +state some higher level abstract + + align:start position:0% +state some higher level abstract + + + align:start position:0% +state some higher level abstract +properties + + align:start position:0% +properties + + + align:start position:0% +properties +either in variants or you'll see some + + align:start position:0% +either in variants or you'll see some + + + align:start position:0% +either in variants or you'll see some +other kinds of + + align:start position:0% +other kinds of + + + align:start position:0% +other kinds of +properties as well + + align:start position:0% + + + + align:start position:0% + +we could say for instance as an + + align:start position:0% +we could say for instance as an + + + align:start position:0% +we could say for instance as an +invariant that all the distance + + align:start position:0% +invariant that all the distance + + + align:start position:0% +invariant that all the distance +information you get + + align:start position:0% +information you get + + + align:start position:0% +information you get +is correct okay + + align:start position:0% +is correct okay + + + align:start position:0% +is correct okay +if you ever have your distance set to + + align:start position:0% +if you ever have your distance set to + + + align:start position:0% +if you ever have your distance set to +something it's the actual distance on + + align:start position:0% +something it's the actual distance on + + + align:start position:0% +something it's the actual distance on +some path and your parent is + + align:start position:0% +some path and your parent is + + + align:start position:0% +some path and your parent is +correct um correctly set to be your + + align:start position:0% +correct um correctly set to be your + + + align:start position:0% +correct um correctly set to be your +predecessor on such a path + + align:start position:0% +predecessor on such a path + + + align:start position:0% +predecessor on such a path +okay so this is just saying whatever you + + align:start position:0% +okay so this is just saying whatever you + + + align:start position:0% +okay so this is just saying whatever you +get is correct information this doesn't + + align:start position:0% +get is correct information this doesn't + + + align:start position:0% +get is correct information this doesn't +say that eventually you're going to + + align:start position:0% +say that eventually you're going to + + + align:start position:0% +say that eventually you're going to +finish though it just says what you get + + align:start position:0% +finish though it just says what you get + + + align:start position:0% +finish though it just says what you get +is correct okay so if + + align:start position:0% +is correct okay so if + + + align:start position:0% +is correct okay so if +if you want to show that eventually you + + align:start position:0% +if you want to show that eventually you + + + align:start position:0% +if you want to show that eventually you +get the right answer you have to do + + align:start position:0% +get the right answer you have to do + + + align:start position:0% +get the right answer you have to do +something with the timing you have to + + align:start position:0% +something with the timing you have to + + + align:start position:0% +something with the timing you have to +say something like + + align:start position:0% + + + + align:start position:0% + +by a certain time that depends on on + + align:start position:0% +by a certain time that depends on on + + + align:start position:0% +by a certain time that depends on on +the distance well if there's an at most + + align:start position:0% +the distance well if there's an at most + + + align:start position:0% +the distance well if there's an at most +r hop path to a node then it will learn + + align:start position:0% +r hop path to a node then it will learn + + + align:start position:0% +r hop path to a node then it will learn +about that + + align:start position:0% +about that + + + align:start position:0% +about that +by a certain time but that depends on + + align:start position:0% +by a certain time but that depends on + + + align:start position:0% +by a certain time but that depends on +the length of the path + + align:start position:0% +the length of the path + + + align:start position:0% +the length of the path +and um the message delivery time and the + + align:start position:0% +and um the message delivery time and the + + + align:start position:0% +and um the message delivery time and the +number of nodes because there can be + + align:start position:0% +number of nodes because there can be + + + align:start position:0% +number of nodes because there can be +congestion + + align:start position:0% +congestion + + + align:start position:0% +congestion +okay so you have to not only say things + + align:start position:0% +okay so you have to not only say things + + + align:start position:0% +okay so you have to not only say things +are correct but you have to say + + align:start position:0% +are correct but you have to say + + + align:start position:0% +are correct but you have to say +eventually + + align:start position:0% +eventually + + + align:start position:0% +eventually +you get the right result and here it + + align:start position:0% +you get the right result and here it + + + align:start position:0% +you get the right result and here it +will say by a certain time you get the + + align:start position:0% +will say by a certain time you get the + + + align:start position:0% +will say by a certain time you get the +right result + + align:start position:0% +right result + + + align:start position:0% +right result +makes sense so this is how you would + + align:start position:0% +makes sense so this is how you would + + + align:start position:0% +makes sense so this is how you would +understand an algorithm like this one + + align:start position:0% +understand an algorithm like this one + + + align:start position:0% +understand an algorithm like this one +okay message complexity + + align:start position:0% +okay message complexity + + + align:start position:0% +okay message complexity +since there's all these corrections + + align:start position:0% +since there's all these corrections + + + align:start position:0% +since there's all these corrections +you're back in number of edges times + + align:start position:0% +you're back in number of edges times + + + align:start position:0% +you're back in number of edges times +possibly the number of nodes + + align:start position:0% +possibly the number of nodes + + + align:start position:0% +possibly the number of nodes +and the time complexity till all the + + align:start position:0% +and the time complexity till all the + + + align:start position:0% +and the time complexity till all the +the distances and parent values + + align:start position:0% +the distances and parent values + + + align:start position:0% +the distances and parent values +stabilize + + align:start position:0% +stabilize + + + align:start position:0% +stabilize +could be this is pessimistic again the + + align:start position:0% +could be this is pessimistic again the + + + align:start position:0% +could be this is pessimistic again the +diameter times the number of nodes times + + align:start position:0% +diameter times the number of nodes times + + + align:start position:0% +diameter times the number of nodes times +d + + align:start position:0% +d + + + align:start position:0% +d +because uh there can be congestion in + + align:start position:0% +because uh there can be congestion in + + + align:start position:0% +because uh there can be congestion in +each of the links + + align:start position:0% +each of the links + + + align:start position:0% +each of the links +because of the corrections okay + + align:start position:0% +because of the corrections okay + + + align:start position:0% +because of the corrections okay +so how do you know when this is done how + + align:start position:0% +so how do you know when this is done how + + + align:start position:0% +so how do you know when this is done how +can a process know when it can finish + + align:start position:0% + + + + align:start position:0% + +idea + + align:start position:0% +idea + + + align:start position:0% +idea +before we we had said well if you knew n + + align:start position:0% +before we we had said well if you knew n + + + align:start position:0% +before we we had said well if you knew n +if you knew the number of nodes you + + align:start position:0% +if you knew the number of nodes you + + + align:start position:0% +if you knew the number of nodes you +could weight that number of rounds + + align:start position:0% +could weight that number of rounds + + + align:start position:0% +could weight that number of rounds +that doesn't even help you here even if + + align:start position:0% +that doesn't even help you here even if + + + align:start position:0% +that doesn't even help you here even if +you know then + + align:start position:0% +you know then + + + align:start position:0% +you know then +have a good upper bound on the number of + + align:start position:0% +have a good upper bound on the number of + + + align:start position:0% +have a good upper bound on the number of +nodes in the network + + align:start position:0% +nodes in the network + + + align:start position:0% +nodes in the network +there's no rounds to count + + align:start position:0% + + + + align:start position:0% + +so you can't tell even knowing the + + align:start position:0% +so you can't tell even knowing the + + + align:start position:0% +so you can't tell even knowing the +number of nodes you can't tell so how + + align:start position:0% +number of nodes you can't tell so how + + + align:start position:0% +number of nodes you can't tell so how +might you detect termination + + align:start position:0% + + + + align:start position:0% + +yeah well but even if you know that + + align:start position:0% +yeah well but even if you know that + + + align:start position:0% +yeah well but even if you know that +you can't count time see this is the + + align:start position:0% +you can't count time see this is the + + + align:start position:0% +you can't count time see this is the +thing about asynchronous algorithms you + + align:start position:0% +thing about asynchronous algorithms you + + + align:start position:0% +thing about asynchronous algorithms you +don't have + + align:start position:0% +don't have + + + align:start position:0% +don't have +although we're using time to measure how + + align:start position:0% +although we're using time to measure how + + + align:start position:0% +although we're using time to measure how +long its + + align:start position:0% +long its + + + align:start position:0% +long its +termination takes we the processes in + + align:start position:0% +termination takes we the processes in + + + align:start position:0% +termination takes we the processes in +there don't have that + + align:start position:0% +there don't have that + + + align:start position:0% +there don't have that +they're just these asynchronous guys who + + align:start position:0% +they're just these asynchronous guys who + + + align:start position:0% +they're just these asynchronous guys who +just take their steps they're ignorant + + align:start position:0% +just take their steps they're ignorant + + + align:start position:0% +just take their steps they're ignorant +of any + + align:start position:0% +of any + + + align:start position:0% +of any +anything to do with time + + align:start position:0% + + + + align:start position:0% + +other ideas yeah can you use the same + + align:start position:0% +other ideas yeah can you use the same + + + align:start position:0% +other ideas yeah can you use the same +convergence + + align:start position:0% +convergence + + + align:start position:0% +convergence +same thing we're just going to use + + align:start position:0% +same thing we're just going to use + + + align:start position:0% +same thing we're just going to use +converge cast again same idea + + align:start position:0% +converge cast again same idea + + + align:start position:0% +converge cast again same idea +you just compute and you recompute your + + align:start position:0% +you just compute and you recompute your + + + align:start position:0% +you just compute and you recompute your +child pointers + + align:start position:0% +child pointers + + + align:start position:0% +child pointers +you send a done to your current parent + + align:start position:0% +you send a done to your current parent + + + align:start position:0% +you send a done to your current parent +after you've gotten responses to all + + align:start position:0% +after you've gotten responses to all + + + align:start position:0% +after you've gotten responses to all +your messages so you think you know your + + align:start position:0% +your messages so you think you know your + + + align:start position:0% +your messages so you think you know your +children and they've all told you + + align:start position:0% +children and they've all told you + + + align:start position:0% +children and they've all told you +they're done + + align:start position:0% +they're done + + + align:start position:0% +they're done +and but then you might have to make + + align:start position:0% +and but then you might have to make + + + align:start position:0% +and but then you might have to make +corrections so as in + + align:start position:0% +corrections so as in + + + align:start position:0% +corrections so as in +what we saw before you can be involved + + align:start position:0% +what we saw before you can be involved + + + align:start position:0% +what we saw before you can be involved +in this converge cast several times till + + align:start position:0% +in this converge cast several times till + + + align:start position:0% +in this converge cast several times till +it finally + + align:start position:0% +it finally + + + align:start position:0% +it finally +reaches all the way to the root okay + + align:start position:0% + + + + align:start position:0% + +once you have these you can use them the + + align:start position:0% +once you have these you can use them the + + + align:start position:0% +once you have these you can use them the +same way as before you + + align:start position:0% +same way as before you + + + align:start position:0% +same way as before you +now have costs that are better than this + + align:start position:0% +now have costs that are better than this + + + align:start position:0% +now have costs that are better than this +simple tree that didn't have shortest + + align:start position:0% +simple tree that didn't have shortest + + + align:start position:0% +simple tree that didn't have shortest +paths because it now takes you less time + + align:start position:0% +paths because it now takes you less time + + + align:start position:0% +paths because it now takes you less time +to use the tree for computing functions + + align:start position:0% +to use the tree for computing functions + + + align:start position:0% +to use the tree for computing functions +or + + align:start position:0% +or + + + align:start position:0% +or +disseminating information because the + + align:start position:0% +disseminating information because the + + + align:start position:0% +disseminating information because the +tree is is shallower + + align:start position:0% +tree is is shallower + + + align:start position:0% +tree is is shallower +okay so finally + + align:start position:0% + + + + align:start position:0% + +what happens when we want to find + + align:start position:0% +what happens when we want to find + + + align:start position:0% +what happens when we want to find +shortest path trees + + align:start position:0% +shortest path trees + + + align:start position:0% +shortest path trees +in an asynchronous setting + + align:start position:0% +in an asynchronous setting + + + align:start position:0% +in an asynchronous setting +so now we're going to add to the + + align:start position:0% +so now we're going to add to the + + + align:start position:0% +so now we're going to add to the +complications that we just saw of all + + align:start position:0% +complications that we just saw of all + + + align:start position:0% +complications that we just saw of all +the asynchrony + + align:start position:0% +the asynchrony + + + align:start position:0% +the asynchrony +the uh complications of having weights + + align:start position:0% +the uh complications of having weights + + + align:start position:0% +the uh complications of having weights +on the edges + + align:start position:0% +on the edges + + + align:start position:0% +on the edges +right so the problem is get a shortest + + align:start position:0% +right so the problem is get a shortest + + + align:start position:0% +right so the problem is get a shortest +path spanning tree + + align:start position:0% +path spanning tree + + + align:start position:0% +path spanning tree +now in an asynchronous network + + align:start position:0% +now in an asynchronous network + + + align:start position:0% +now in an asynchronous network +weighted graph + + align:start position:0% + + + + align:start position:0% + +processes don't know about the graph + + align:start position:0% +processes don't know about the graph + + + align:start position:0% +processes don't know about the graph +again + + align:start position:0% +again + + + align:start position:0% +again +they have uids + + align:start position:0% + + + + align:start position:0% + +and everybody's supposed to output its + + align:start position:0% +and everybody's supposed to output its + + + align:start position:0% +and everybody's supposed to output its +distance and parent in the tree + + align:start position:0% + + + + align:start position:0% + +okay so um + + align:start position:0% +okay so um + + + align:start position:0% +okay so um +we're going to use another relaxation + + align:start position:0% +we're going to use another relaxation + + + align:start position:0% +we're going to use another relaxation +algorithm + + align:start position:0% +algorithm + + + align:start position:0% +algorithm +okay so now think about what the + + align:start position:0% +okay so now think about what the + + + align:start position:0% +okay so now think about what the +relaxation is going to be doing for you + + align:start position:0% + + + + align:start position:0% + +we have two kinds of corrections to make + + align:start position:0% + + + + align:start position:0% + +you could have long paths that have + + align:start position:0% +you could have long paths that have + + + align:start position:0% +you could have long paths that have +small weight + + align:start position:0% +small weight + + + align:start position:0% +small weight +that showed up for bellman ford in the + + align:start position:0% +that showed up for bellman ford in the + + + align:start position:0% +that showed up for bellman ford in the +synchronous setting + + align:start position:0% +synchronous setting + + + align:start position:0% +synchronous setting +so we have to correct for those but you + + align:start position:0% +so we have to correct for those but you + + + align:start position:0% +so we have to correct for those but you +could also have because of asynchrony + + align:start position:0% +could also have because of asynchrony + + + align:start position:0% +could also have because of asynchrony +you could have information traveling + + align:start position:0% +you could have information traveling + + + align:start position:0% +you could have information traveling +fast on uh + + align:start position:0% +fast on uh + + + align:start position:0% +fast on uh +many hops and you have to correct for + + align:start position:0% +many hops and you have to correct for + + + align:start position:0% +many hops and you have to correct for +that as well so there's like two kinds + + align:start position:0% +that as well so there's like two kinds + + + align:start position:0% +that as well so there's like two kinds +of things you're going to be correcting + + align:start position:0% +of things you're going to be correcting + + + align:start position:0% +of things you're going to be correcting +for in one algorithm + + align:start position:0% + + + + align:start position:0% + +okay so this is going to and this is + + align:start position:0% +okay so this is going to and this is + + + align:start position:0% +okay so this is going to and this is +pretty surprising it's going to lead to + + align:start position:0% +pretty surprising it's going to lead to + + + align:start position:0% +pretty surprising it's going to lead to +ridiculously high + + align:start position:0% +ridiculously high + + + align:start position:0% +ridiculously high +complexity message and time complexity + + align:start position:0% +complexity message and time complexity + + + align:start position:0% +complexity message and time complexity +if you really have unbridled asynchrony + + align:start position:0% +if you really have unbridled asynchrony + + + align:start position:0% +if you really have unbridled asynchrony +and weights + + align:start position:0% +and weights + + + align:start position:0% +and weights +this is going to give you a very costly + + align:start position:0% +this is going to give you a very costly + + + align:start position:0% +this is going to give you a very costly +algorithm you're going to + + align:start position:0% +algorithm you're going to + + + align:start position:0% +algorithm you're going to +see some exponential is going to creep + + align:start position:0% +see some exponential is going to creep + + + align:start position:0% +see some exponential is going to creep +in there + + align:start position:0% +in there + + + align:start position:0% +in there +okay so here's the the algorithm for the + + align:start position:0% +okay so here's the the algorithm for the + + + align:start position:0% +okay so here's the the algorithm for the +asynchronous bellman ford + + align:start position:0% +asynchronous bellman ford + + + align:start position:0% +asynchronous bellman ford +algorithm everyone keeps track of their + + align:start position:0% +algorithm everyone keeps track of their + + + align:start position:0% +algorithm everyone keeps track of their +parent + + align:start position:0% +parent + + + align:start position:0% +parent +their conjecture distance and + + align:start position:0% +their conjecture distance and + + + align:start position:0% +their conjecture distance and +they have now messages that they're + + align:start position:0% +they have now messages that they're + + + align:start position:0% +they have now messages that they're +going + + align:start position:0% +going + + + align:start position:0% +going +to send to the neighbors let's say you + + align:start position:0% +to send to the neighbors let's say you + + + align:start position:0% +to send to the neighbors let's say you +have a queue because there could be + + align:start position:0% +have a queue because there could be + + + align:start position:0% +have a queue because there could be +successive + + align:start position:0% +successive + + + align:start position:0% +successive +estimates so we'll have a queue there + + align:start position:0% +estimates so we'll have a queue there + + + align:start position:0% +estimates so we'll have a queue there +um key step the relaxation step is what + + align:start position:0% +um key step the relaxation step is what + + + align:start position:0% +um key step the relaxation step is what +happens when you receive + + align:start position:0% +happens when you receive + + + align:start position:0% +happens when you receive +a new um estimate of the best distance + + align:start position:0% +a new um estimate of the best distance + + + align:start position:0% +a new um estimate of the best distance +this is weighted distance now from a + + align:start position:0% +this is weighted distance now from a + + + align:start position:0% +this is weighted distance now from a +neighbor + + align:start position:0% +neighbor + + + align:start position:0% +neighbor +well you look at that distance plus the + + align:start position:0% +well you look at that distance plus the + + + align:start position:0% +well you look at that distance plus the +weight of the edge in between + + align:start position:0% +weight of the edge in between + + + align:start position:0% +weight of the edge in between +and you see if that's better than your + + align:start position:0% +and you see if that's better than your + + + align:start position:0% +and you see if that's better than your +current distance + + align:start position:0% +current distance + + + align:start position:0% +current distance +just like synchronous bellman ford and + + align:start position:0% +just like synchronous bellman ford and + + + align:start position:0% +just like synchronous bellman ford and +if it is + + align:start position:0% +if it is + + + align:start position:0% +if it is +then you improve your distance + + align:start position:0% +then you improve your distance + + + align:start position:0% +then you improve your distance +reset your parent and send this the + + align:start position:0% +reset your parent and send this the + + + align:start position:0% +reset your parent and send this the +distance out to your neighbors + + align:start position:0% +distance out to your neighbors + + + align:start position:0% +distance out to your neighbors +so it's exactly like the synchronous + + align:start position:0% +so it's exactly like the synchronous + + + align:start position:0% +so it's exactly like the synchronous +case + + align:start position:0% +case + + + align:start position:0% +case +but we're going to be running this + + align:start position:0% +but we're going to be running this + + + align:start position:0% +but we're going to be running this +asynchronously + + align:start position:0% +asynchronously + + + align:start position:0% +asynchronously +and since you're going to be correcting + + align:start position:0% +and since you're going to be correcting + + + align:start position:0% +and since you're going to be correcting +um every time you see a new estimate + + align:start position:0% +um every time you see a new estimate + + + align:start position:0% +um every time you see a new estimate +this is actually going to handle both + + align:start position:0% +this is actually going to handle both + + + align:start position:0% +this is actually going to handle both +kinds of corrections + + align:start position:0% +kinds of corrections + + + align:start position:0% +kinds of corrections +whether it comes because of you know + + align:start position:0% +whether it comes because of you know + + + align:start position:0% +whether it comes because of you know +a mini hop path with a smaller weight or + + align:start position:0% +a mini hop path with a smaller weight or + + + align:start position:0% +a mini hop path with a smaller weight or +whether + + align:start position:0% +whether + + + align:start position:0% +whether +it just comes because of the asynchrony + + align:start position:0% +it just comes because of the asynchrony + + + align:start position:0% +it just comes because of the asynchrony +whenever you get a better estimate + + align:start position:0% +whenever you get a better estimate + + + align:start position:0% +whenever you get a better estimate +you're going to make the correction + + align:start position:0% +you're going to make the correction + + + align:start position:0% +you're going to make the correction +okay is it clear this is all you really + + align:start position:0% +okay is it clear this is all you really + + + align:start position:0% +okay is it clear this is all you really +need to do in the algorithm just what's + + align:start position:0% +need to do in the algorithm just what's + + + align:start position:0% +need to do in the algorithm just what's +in this + + align:start position:0% +in this + + + align:start position:0% +in this +this code + + align:start position:0% + + + + align:start position:0% + +okay so that's the receive and then the + + align:start position:0% +okay so that's the receive and then the + + + align:start position:0% +okay so that's the receive and then the +rest of the algorithm is just you send + + align:start position:0% +rest of the algorithm is just you send + + + align:start position:0% +rest of the algorithm is just you send +it out + + align:start position:0% +it out + + + align:start position:0% +it out +when it's when you're ready to send + + align:start position:0% + + + + align:start position:0% + +okay and then we have the same uh issue + + align:start position:0% +okay and then we have the same uh issue + + + align:start position:0% +okay and then we have the same uh issue +about termination + + align:start position:0% +about termination + + + align:start position:0% +about termination +there's no uh no termination + + align:start position:0% +there's no uh no termination + + + align:start position:0% +there's no uh no termination +terminating actions we'll come back to + + align:start position:0% +terminating actions we'll come back to + + + align:start position:0% +terminating actions we'll come back to +that + + align:start position:0% +that + + + align:start position:0% +that +so you know it's really hard to come up + + align:start position:0% +so you know it's really hard to come up + + + align:start position:0% +so you know it's really hard to come up +with invariance and timing properties + + align:start position:0% +with invariance and timing properties + + + align:start position:0% +with invariance and timing properties +now for this + + align:start position:0% +now for this + + + align:start position:0% +now for this +setting you can certainly have an + + align:start position:0% +setting you can certainly have an + + + align:start position:0% +setting you can certainly have an +invariant like the one that we just had + + align:start position:0% +invariant like the one that we just had + + + align:start position:0% +invariant like the one that we just had +for asynchronous breadth first search + + align:start position:0% +for asynchronous breadth first search + + + align:start position:0% +for asynchronous breadth first search +you can say that at any point whatever + + align:start position:0% +you can say that at any point whatever + + + align:start position:0% +you can say that at any point whatever +distance you have + + align:start position:0% +distance you have + + + align:start position:0% +distance you have +is an actual distance it's achievable + + align:start position:0% +is an actual distance it's achievable + + + align:start position:0% +is an actual distance it's achievable +along some path + + align:start position:0% +along some path + + + align:start position:0% +along some path +and the parent is correct + + align:start position:0% +and the parent is correct + + + align:start position:0% +and the parent is correct +we'd also like to have something that + + align:start position:0% +we'd also like to have something that + + + align:start position:0% +we'd also like to have something that +says eventually you get the right + + align:start position:0% +says eventually you get the right + + + align:start position:0% +says eventually you get the right +distance + + align:start position:0% + + + + align:start position:0% + +so you want to state a timing property + + align:start position:0% +so you want to state a timing property + + + align:start position:0% +so you want to state a timing property +that says fine if you have an at most + + align:start position:0% +that says fine if you have an at most + + + align:start position:0% +that says fine if you have an at most +r hop path by a certain time you'd like + + align:start position:0% +r hop path by a certain time you'd like + + + align:start position:0% +r hop path by a certain time you'd like +to know that your distance + + align:start position:0% +to know that your distance + + + align:start position:0% +to know that your distance +is at least as good as what you could + + align:start position:0% +is at least as good as what you could + + + align:start position:0% +is at least as good as what you could +get on that path + + align:start position:0% +get on that path + + + align:start position:0% +get on that path +the quest the problem is what are you + + align:start position:0% +the quest the problem is what are you + + + align:start position:0% +the quest the problem is what are you +going to + + align:start position:0% +going to + + + align:start position:0% +going to +have here for the amount of time how + + align:start position:0% +have here for the amount of time how + + + align:start position:0% +have here for the amount of time how +long would it possibly + + align:start position:0% +long would it possibly + + + align:start position:0% +long would it possibly +take in order to get + + align:start position:0% +take in order to get + + + align:start position:0% +take in order to get +the best estimate that you could for + + align:start position:0% +the best estimate that you could for + + + align:start position:0% +the best estimate that you could for +a path of at most our hops + + align:start position:0% + + + + align:start position:0% + +okay a guess + + align:start position:0% +okay a guess + + + align:start position:0% +okay a guess +i was able to calculate something + + align:start position:0% +i was able to calculate something + + + align:start position:0% +i was able to calculate something +reasonable for the breadth first search + + align:start position:0% +reasonable for the breadth first search + + + align:start position:0% +reasonable for the breadth first search +case + + align:start position:0% +case + + + align:start position:0% +case +but now this is going to be much much + + align:start position:0% +but now this is going to be much much + + + align:start position:0% +but now this is going to be much much +worse + + align:start position:0% +worse + + + align:start position:0% +worse +it's not obvious at all it's actually + + align:start position:0% +it's not obvious at all it's actually + + + align:start position:0% +it's not obvious at all it's actually +going to + + align:start position:0% +going to + + + align:start position:0% +going to +depend on how many messages could pile + + align:start position:0% +depend on how many messages could pile + + + align:start position:0% +depend on how many messages could pile +up in a channel + + align:start position:0% +up in a channel + + + align:start position:0% +up in a channel +and that can be an awful lot an + + align:start position:0% +and that can be an awful lot an + + + align:start position:0% +and that can be an awful lot an +exponential number + + align:start position:0% +exponential number + + + align:start position:0% +exponential number +exponential and the number of nodes in + + align:start position:0% +exponential and the number of nodes in + + + align:start position:0% +exponential and the number of nodes in +the network + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so here's um + + align:start position:0% + + + + align:start position:0% + +i'm going to produce an execution for + + align:start position:0% +i'm going to produce an execution for + + + align:start position:0% +i'm going to produce an execution for +you that + + align:start position:0% + + + + align:start position:0% + +can generate a huge number of messages + + align:start position:0% +can generate a huge number of messages + + + align:start position:0% +can generate a huge number of messages +which then will take a long + + align:start position:0% +which then will take a long + + + align:start position:0% +which then will take a long +time to deliver and delay the + + align:start position:0% +time to deliver and delay the + + + align:start position:0% +time to deliver and delay the +termination of the algorithm + + align:start position:0% +termination of the algorithm + + + align:start position:0% +termination of the algorithm +first let's look at an upper bound what + + align:start position:0% +first let's look at an upper bound what + + + align:start position:0% +first let's look at an upper bound what +can we say for an upper bound + + align:start position:0% +can we say for an upper bound + + + align:start position:0% +can we say for an upper bound +well there's many different paths from + + align:start position:0% +well there's many different paths from + + + align:start position:0% +well there's many different paths from +v0 + + align:start position:0% +v0 + + + align:start position:0% +v0 +to any other particular node so + + align:start position:0% +to any other particular node so + + + align:start position:0% +to any other particular node so +we might have to traverse + + align:start position:0% + + + + align:start position:0% + +all the simple paths in the graph + + align:start position:0% +all the simple paths in the graph + + + align:start position:0% +all the simple paths in the graph +perhaps + + align:start position:0% +perhaps + + + align:start position:0% +perhaps +and how many are there well + + align:start position:0% +and how many are there well + + + align:start position:0% +and how many are there well +as an upper bound you could say order n + + align:start position:0% +as an upper bound you could say order n + + + align:start position:0% +as an upper bound you could say order n +factorial for the number of different + + align:start position:0% +factorial for the number of different + + + align:start position:0% +factorial for the number of different +paths that you can + + align:start position:0% +paths that you can + + + align:start position:0% +paths that you can +traverse to get from v0 to some + + align:start position:0% +traverse to get from v0 to some + + + align:start position:0% +traverse to get from v0 to some +particular other node + + align:start position:0% +particular other node + + + align:start position:0% +particular other node +so that's exponential in n certainly + + align:start position:0% +so that's exponential in n certainly + + + align:start position:0% +so that's exponential in n certainly +it's order n to the n + + align:start position:0% + + + + align:start position:0% + +okay so this says that the number of + + align:start position:0% +okay so this says that the number of + + + align:start position:0% +okay so this says that the number of +messages that you might send on any + + align:start position:0% +messages that you might send on any + + + align:start position:0% +messages that you might send on any +channel could correspond to + + align:start position:0% +channel could correspond to + + + align:start position:0% +channel could correspond to +doing that many corrections so this can + + align:start position:0% +doing that many corrections so this can + + + align:start position:0% +doing that many corrections so this can +blow up your message complexity + + align:start position:0% +blow up your message complexity + + + align:start position:0% +blow up your message complexity +into n to the n times the number of + + align:start position:0% +into n to the n times the number of + + + align:start position:0% +into n to the n times the number of +edges and your time complexity + + align:start position:0% +edges and your time complexity + + + align:start position:0% +edges and your time complexity +in uh to n to the n times + + align:start position:0% +in uh to n to the n times + + + align:start position:0% +in uh to n to the n times +um n times d because on every edge + + align:start position:0% +um n times d because on every edge + + + align:start position:0% +um n times d because on every edge +you might have to wait for that many + + align:start position:0% +you might have to wait for that many + + + align:start position:0% +you might have to wait for that many +messages + + align:start position:0% +messages + + + align:start position:0% +messages +corrected messages sitting in front of + + align:start position:0% +corrected messages sitting in front of + + + align:start position:0% +corrected messages sitting in front of +you + + align:start position:0% +you + + + align:start position:0% +you +okay so you know that seems pretty awful + + align:start position:0% +okay so you know that seems pretty awful + + + align:start position:0% +okay so you know that seems pretty awful +does it actually happen can you actually + + align:start position:0% +does it actually happen can you actually + + + align:start position:0% +does it actually happen can you actually +construct an execution of this algorithm + + align:start position:0% +construct an execution of this algorithm + + + align:start position:0% +construct an execution of this algorithm +where you get exponential bounds like + + align:start position:0% +where you get exponential bounds like + + + align:start position:0% +where you get exponential bounds like +that + + align:start position:0% +that + + + align:start position:0% +that +and we'll see that yes uh you can any + + align:start position:0% +and we'll see that yes uh you can any + + + align:start position:0% +and we'll see that yes uh you can any +questions so far + + align:start position:0% +questions so far + + + align:start position:0% +questions so far +okay so here's a bad example + + align:start position:0% +okay so here's a bad example + + + align:start position:0% +okay so here's a bad example +so this is a network consists of a + + align:start position:0% +so this is a network consists of a + + + align:start position:0% +so this is a network consists of a +sequence of + + align:start position:0% +sequence of + + + align:start position:0% +sequence of +let's say k k plus 1 no k plus 2 i guess + + align:start position:0% +let's say k k plus 1 no k plus 2 i guess + + + align:start position:0% +let's say k k plus 1 no k plus 2 i guess +nodes in a line + + align:start position:0% +nodes in a line + + + align:start position:0% +nodes in a line +and i'm going to throw in + + align:start position:0% +and i'm going to throw in + + + align:start position:0% +and i'm going to throw in +some little detour nodes in between each + + align:start position:0% +some little detour nodes in between each + + + align:start position:0% +some little detour nodes in between each +consecutive pair of nodes + + align:start position:0% +consecutive pair of nodes + + + align:start position:0% +consecutive pair of nodes +in this graph and now let me play with + + align:start position:0% +in this graph and now let me play with + + + align:start position:0% +in this graph and now let me play with +the weights + + align:start position:0% +the weights + + + align:start position:0% +the weights +let's say on this path this direct path + + align:start position:0% +let's say on this path this direct path + + + align:start position:0% +let's say on this path this direct path +from v 0 to v k plus 1 all the weights + + align:start position:0% +from v 0 to v k plus 1 all the weights + + + align:start position:0% +from v 0 to v k plus 1 all the weights +are zero + + align:start position:0% +are zero + + + align:start position:0% +are zero +so that's going to be the the shortest + + align:start position:0% +so that's going to be the the shortest + + + align:start position:0% +so that's going to be the the shortest +path the best weight path + + align:start position:0% +path the best weight path + + + align:start position:0% +path the best weight path +from v zero to v k plus one + + align:start position:0% +from v zero to v k plus one + + + align:start position:0% +from v zero to v k plus one +but now i'm going to have some detours + + align:start position:0% +but now i'm going to have some detours + + + align:start position:0% +but now i'm going to have some detours +and on on the detours i have two edges + + align:start position:0% +and on on the detours i have two edges + + + align:start position:0% +and on on the detours i have two edges +one of weight zero and the other one of + + align:start position:0% +one of weight zero and the other one of + + + align:start position:0% +one of weight zero and the other one of +weight that's the power of two + + align:start position:0% +weight that's the power of two + + + align:start position:0% +weight that's the power of two +i'm going to start with high powers of 2 + + align:start position:0% +i'm going to start with high powers of 2 + + + align:start position:0% +i'm going to start with high powers of 2 +2 to the k minus 1 then go down + + align:start position:0% +2 to the k minus 1 then go down + + + align:start position:0% +2 to the k minus 1 then go down +2 to the k minus 2 down to 2 to the 1 2 + + align:start position:0% +2 to the k minus 2 down to 2 to the 1 2 + + + align:start position:0% +2 to the k minus 2 down to 2 to the 1 2 +to the 0. + + align:start position:0% +to the 0. + + + align:start position:0% +to the 0. +okay so you see what this graph is is + + align:start position:0% +okay so you see what this graph is is + + + align:start position:0% +okay so you see what this graph is is +doing it has a very fast path in the + + align:start position:0% +doing it has a very fast path in the + + + align:start position:0% +doing it has a very fast path in the +bottom + + align:start position:0% +bottom + + + align:start position:0% +bottom +if you'd like to hear about as soon as + + align:start position:0% +if you'd like to hear about as soon as + + + align:start position:0% +if you'd like to hear about as soon as +you can but + + align:start position:0% +you can but + + + align:start position:0% +you can but +actually there's detours which could + + align:start position:0% +actually there's detours which could + + + align:start position:0% +actually there's detours which could +give you much worse paths + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +so let's see how this might execute to + + align:start position:0% +so let's see how this might execute to + + + align:start position:0% +so let's see how this might execute to +make a lot of messages pile up in a + + align:start position:0% +make a lot of messages pile up in a + + + align:start position:0% +make a lot of messages pile up in a +channel + + align:start position:0% +channel + + + align:start position:0% +channel +okay so my claim is that there's an + + align:start position:0% +okay so my claim is that there's an + + + align:start position:0% +okay so my claim is that there's an +execution of that network + + align:start position:0% +execution of that network + + + align:start position:0% +execution of that network +in which the last node vk + + align:start position:0% +in which the last node vk + + + align:start position:0% +in which the last node vk +sends two to the k + + align:start position:0% +sends two to the k + + + align:start position:0% +sends two to the k +messages to the next node v k plus one + + align:start position:0% +messages to the next node v k plus one + + + align:start position:0% +messages to the next node v k plus one +so he's really going to send an + + align:start position:0% +so he's really going to send an + + + align:start position:0% +so he's really going to send an +exponential number of messages + + align:start position:0% +exponential number of messages + + + align:start position:0% +exponential number of messages +corresponding to his + + align:start position:0% +corresponding to his + + + align:start position:0% +corresponding to his +corrections he's going to keep making + + align:start position:0% +corrections he's going to keep making + + + align:start position:0% +corrections he's going to keep making +corrections for better and better + + align:start position:0% +corrections for better and better + + + align:start position:0% +corrections for better and better +estimates + + align:start position:0% +estimates + + + align:start position:0% +estimates +okay and if all this happens relatively + + align:start position:0% +okay and if all this happens relatively + + + align:start position:0% +okay and if all this happens relatively +fast + + align:start position:0% +fast + + + align:start position:0% +fast +that just means you have a channel with + + align:start position:0% +that just means you have a channel with + + + align:start position:0% +that just means you have a channel with +an exponential number of messages in it + + align:start position:0% +an exponential number of messages in it + + + align:start position:0% +an exponential number of messages in it +emptying that will take exponential time + + align:start position:0% +emptying that will take exponential time + + + align:start position:0% +emptying that will take exponential time +okay okay so + + align:start position:0% +okay okay so + + + align:start position:0% +okay okay so +you have an idea how this might happen + + align:start position:0% +you have an idea how this might happen + + + align:start position:0% +you have an idea how this might happen +how could this node + + align:start position:0% +how could this node + + + align:start position:0% +how could this node +be k get so many successively improved + + align:start position:0% +be k get so many successively improved + + + align:start position:0% +be k get so many successively improved +estimates one after the other + + align:start position:0% + + + + align:start position:0% + +well what's the biggest estimate it + + align:start position:0% +well what's the biggest estimate it + + + align:start position:0% +well what's the biggest estimate it +might get + + align:start position:0% + + + + align:start position:0% + +could get two to the k minus one well + + align:start position:0% +could get two to the k minus one well + + + align:start position:0% +could get two to the k minus one well +let's see could do that + + align:start position:0% +let's see could do that + + + align:start position:0% +let's see could do that +and it could do that plus 2 plus 2 to + + align:start position:0% +and it could do that plus 2 plus 2 to + + + align:start position:0% +and it could do that plus 2 plus 2 to +the k minus 2 plus + + align:start position:0% +the k minus 2 plus + + + align:start position:0% +the k minus 2 plus +all the way down to plus 2 to the zero + + align:start position:0% +all the way down to plus 2 to the zero + + + align:start position:0% +all the way down to plus 2 to the zero +so you could be following this really + + align:start position:0% +so you could be following this really + + + align:start position:0% +so you could be following this really +inefficient path just all the detours + + align:start position:0% +inefficient path just all the detours + + + align:start position:0% +inefficient path just all the detours +before the messages actually arrive on + + align:start position:0% +before the messages actually arrive on + + + align:start position:0% +before the messages actually arrive on +the edges on the spine yeah so + + align:start position:0% +the edges on the spine yeah so + + + align:start position:0% +the edges on the spine yeah so +you follow all oh oh you said two to the + + align:start position:0% +you follow all oh oh you said two to the + + + align:start position:0% +you follow all oh oh you said two to the +k + + align:start position:0% +k + + + align:start position:0% +k +minus one parentheses yeah that's + + align:start position:0% +minus one parentheses yeah that's + + + align:start position:0% +minus one parentheses yeah that's +exactly right + + align:start position:0% +exactly right + + + align:start position:0% +exactly right +that's all right we can't + + align:start position:0% +that's all right we can't + + + align:start position:0% +that's all right we can't +parenthesize our speech so all right + + align:start position:0% +parenthesize our speech so all right + + + align:start position:0% +parenthesize our speech so all right +so the possible estimates that bk can + + align:start position:0% +so the possible estimates that bk can + + + align:start position:0% +so the possible estimates that bk can +take on + + align:start position:0% +take on + + + align:start position:0% +take on +are actually 2 to the k + + align:start position:0% +are actually 2 to the k + + + align:start position:0% +are actually 2 to the k +as you said 2 to the k minus 1 + + align:start position:0% +as you said 2 to the k minus 1 + + + align:start position:0% +as you said 2 to the k minus 1 +which you would get by taking all the + + align:start position:0% +which you would get by taking all the + + + align:start position:0% +which you would get by taking all the +detours adding up the powers of 2 + + align:start position:0% + + + + align:start position:0% + +but it could also have an estimate which + + align:start position:0% +but it could also have an estimate which + + + align:start position:0% +but it could also have an estimate which +is 2 to the k minus 2 + + align:start position:0% +is 2 to the k minus 2 + + + align:start position:0% +is 2 to the k minus 2 +or 2 to the k minus 3. all of those are + + align:start position:0% +or 2 to the k minus 3. all of those are + + + align:start position:0% +or 2 to the k minus 3. all of those are +possible + + align:start position:0% +possible + + + align:start position:0% +possible +moreover you can have a single execution + + align:start position:0% +moreover you can have a single execution + + + align:start position:0% +moreover you can have a single execution +of this asynchronous algorithm + + align:start position:0% +of this asynchronous algorithm + + + align:start position:0% +of this asynchronous algorithm +in which node bk actually acquires + + align:start position:0% +in which node bk actually acquires + + + align:start position:0% +in which node bk actually acquires +all those estimates in sequence one at a + + align:start position:0% +all those estimates in sequence one at a + + + align:start position:0% +all those estimates in sequence one at a +time + + align:start position:0% +time + + + align:start position:0% +time +so how much that work first the messages + + align:start position:0% +so how much that work first the messages + + + align:start position:0% +so how much that work first the messages +travel all the detours + + align:start position:0% +travel all the detours + + + align:start position:0% +travel all the detours +fine v k gets two to the k minus one + + align:start position:0% +fine v k gets two to the k minus one + + + align:start position:0% +fine v k gets two to the k minus one +then there's a message traveling + + align:start position:0% +then there's a message traveling + + + align:start position:0% +then there's a message traveling +well this guy sends a message on the + + align:start position:0% +well this guy sends a message on the + + + align:start position:0% +well this guy sends a message on the +lower link + + align:start position:0% +lower link + + + align:start position:0% +lower link +so this guy has only heard about the + + align:start position:0% +so this guy has only heard about the + + + align:start position:0% +so this guy has only heard about the +messages on the detours up to that point + + align:start position:0% +messages on the detours up to that point + + + align:start position:0% +messages on the detours up to that point +but he sends that on this lower link + + align:start position:0% +but he sends that on this lower link + + + align:start position:0% +but he sends that on this lower link +which means you've kind of bypassed this + + align:start position:0% +which means you've kind of bypassed this + + + align:start position:0% +which means you've kind of bypassed this +weight of one + + align:start position:0% +weight of one + + + align:start position:0% +weight of one +so vk gets a little bit of an + + align:start position:0% +so vk gets a little bit of an + + + align:start position:0% +so vk gets a little bit of an +improvement + + align:start position:0% +improvement + + + align:start position:0% +improvement +which gives it 2 to the k minus 2 as its + + align:start position:0% +which gives it 2 to the k minus 2 as its + + + align:start position:0% +which gives it 2 to the k minus 2 as its +estimate + + align:start position:0% +estimate + + + align:start position:0% +estimate +okay so what happens next + + align:start position:0% + + + + align:start position:0% + +well we step one back and the node from + + align:start position:0% +well we step one back and the node from + + + align:start position:0% +well we step one back and the node from +node k minus two can send a message + + align:start position:0% +node k minus two can send a message + + + align:start position:0% +node k minus two can send a message +on the lower link + + align:start position:0% +on the lower link + + + align:start position:0% +on the lower link +which has weight zero uh to be k minus + + align:start position:0% +which has weight zero uh to be k minus + + + align:start position:0% +which has weight zero uh to be k minus +one + + align:start position:0% +one + + + align:start position:0% +one +but that corrected estimate might then + + align:start position:0% +but that corrected estimate might then + + + align:start position:0% +but that corrected estimate might then +traverse + + align:start position:0% +traverse + + + align:start position:0% +traverse +the detour to get to + + align:start position:0% +the detour to get to + + + align:start position:0% +the detour to get to +node vk so if you get the correction + + align:start position:0% +node vk so if you get the correction + + + align:start position:0% +node vk so if you get the correction +for node bk minus 1 but then you follow + + align:start position:0% +for node bk minus 1 but then you follow + + + align:start position:0% +for node bk minus 1 but then you follow +the detour + + align:start position:0% +the detour + + + align:start position:0% +the detour +you haven't improved that much you've + + align:start position:0% +you haven't improved that much you've + + + align:start position:0% +you haven't improved that much you've +just improved by + + align:start position:0% +just improved by + + + align:start position:0% +just improved by +1. so this way you get 2 to the k minus + + align:start position:0% +1. so this way you get 2 to the k minus + + + align:start position:0% +1. so this way you get 2 to the k minus + + align:start position:0% + + + align:start position:0% +as the new estimate but then again on + + align:start position:0% +as the new estimate but then again on + + + align:start position:0% +as the new estimate but then again on +the lower link + + align:start position:0% +the lower link + + + align:start position:0% +the lower link +the message eventually arrives which + + align:start position:0% +the message eventually arrives which + + + align:start position:0% +the message eventually arrives which +gives you + + align:start position:0% +gives you + + + align:start position:0% +gives you +2 to the k minus 4. so you see the + + align:start position:0% +2 to the k minus 4. so you see the + + + align:start position:0% +2 to the k minus 4. so you see the +pattern sort of + + align:start position:0% +pattern sort of + + + align:start position:0% +pattern sort of +you're going to be counting down in + + align:start position:0% +you're going to be counting down in + + + align:start position:0% +you're going to be counting down in +binary by + + align:start position:0% +binary by + + + align:start position:0% +binary by +successively having nodes further to the + + align:start position:0% +successively having nodes further to the + + + align:start position:0% +successively having nodes further to the +left + + align:start position:0% +left + + + align:start position:0% +left +deliver their messages but then they do + + align:start position:0% +deliver their messages but then they do + + + align:start position:0% +deliver their messages but then they do +the worst possible thing of getting the + + align:start position:0% +the worst possible thing of getting the + + + align:start position:0% +the worst possible thing of getting the +information + + align:start position:0% +information + + + align:start position:0% +information +to vk he has to deal with all those + + align:start position:0% +to vk he has to deal with all those + + + align:start position:0% +to vk he has to deal with all those +other estimates in between + + align:start position:0% +other estimates in between + + + align:start position:0% +other estimates in between +so if this happens quickly what you get + + align:start position:0% +so if this happens quickly what you get + + + align:start position:0% +so if this happens quickly what you get +is a pile up of + + align:start position:0% +is a pile up of + + + align:start position:0% +is a pile up of +an exponential number of search messages + + align:start position:0% +an exponential number of search messages + + + align:start position:0% +an exponential number of search messages +in one channel + + align:start position:0% +in one channel + + + align:start position:0% +in one channel +and then that information has to go on + + align:start position:0% +and then that information has to go on + + + align:start position:0% +and then that information has to go on +to the next node or the rest of the + + align:start position:0% +to the next node or the rest of the + + + align:start position:0% +to the next node or the rest of the +network whatever it's going to take an + + align:start position:0% +network whatever it's going to take an + + + align:start position:0% +network whatever it's going to take an +exponential amount of time in the worst + + align:start position:0% +exponential amount of time in the worst + + + align:start position:0% +exponential amount of time in the worst +case to empty that + + align:start position:0% +case to empty that + + + align:start position:0% +case to empty that +all out okay + + align:start position:0% +all out okay + + + align:start position:0% +all out okay +so this is pretty bad + + align:start position:0% + + + + align:start position:0% + +okay but the algorithm is correct + + align:start position:0% +okay but the algorithm is correct + + + align:start position:0% +okay but the algorithm is correct +and so how do you learn when + + align:start position:0% +and so how do you learn when + + + align:start position:0% +and so how do you learn when +everything is finished and how does a + + align:start position:0% +everything is finished and how does a + + + align:start position:0% +everything is finished and how does a +process know when it it can + + align:start position:0% +process know when it it can + + + align:start position:0% +process know when it it can +output its own correct distance + + align:start position:0% +output its own correct distance + + + align:start position:0% +output its own correct distance +information + + align:start position:0% +information + + + align:start position:0% +information +how can we figure out when this is all + + align:start position:0% +how can we figure out when this is all + + + align:start position:0% +how can we figure out when this is all +stabilized + + align:start position:0% + + + + align:start position:0% + +same thing as before so okay + + align:start position:0% +same thing as before so okay + + + align:start position:0% +same thing as before so okay +we can just do a converge cast i mean + + align:start position:0% +we can just do a converge cast i mean + + + align:start position:0% +we can just do a converge cast i mean +this is more corrections but it's still + + align:start position:0% +this is more corrections but it's still + + + align:start position:0% +this is more corrections but it's still +the same kind of corrections so we can + + align:start position:0% +the same kind of corrections so we can + + + align:start position:0% +the same kind of corrections so we can +converge casts and eventually + + align:start position:0% +converge casts and eventually + + + align:start position:0% +converge casts and eventually +this is going to converge cast all the + + align:start position:0% +this is going to converge cast all the + + + align:start position:0% +this is going to converge cast all the +way up to the root + + align:start position:0% +way up to the root + + + align:start position:0% +way up to the root +and then the root knows it's done and + + align:start position:0% +and then the root knows it's done and + + + align:start position:0% +and then the root knows it's done and +can tell everyone else + + align:start position:0% +can tell everyone else + + + align:start position:0% +can tell everyone else +okay okay so a moral here + + align:start position:0% +okay okay so a moral here + + + align:start position:0% +okay okay so a moral here +and you've had a quick dose of a lot of + + align:start position:0% +and you've had a quick dose of a lot of + + + align:start position:0% +and you've had a quick dose of a lot of +asynchrony + + align:start position:0% +asynchrony + + + align:start position:0% +asynchrony +so yeah if you don't do anything about + + align:start position:0% +so yeah if you don't do anything about + + + align:start position:0% +so yeah if you don't do anything about +it if you just use unrestrained + + align:start position:0% +it if you just use unrestrained + + + align:start position:0% +it if you just use unrestrained +asynchrony in the worst case + + align:start position:0% +asynchrony in the worst case + + + align:start position:0% +asynchrony in the worst case +uh you're going to have some pretty bad + + align:start position:0% +uh you're going to have some pretty bad + + + align:start position:0% +uh you're going to have some pretty bad +performance so + + align:start position:0% +performance so + + + align:start position:0% +performance so +the question is what do you do about + + align:start position:0% +the question is what do you do about + + + align:start position:0% +the question is what do you do about +that and there are various techniques + + align:start position:0% +that and there are various techniques + + + align:start position:0% +that and there are various techniques +and if you want to take my course next + + align:start position:0% +and if you want to take my course next + + + align:start position:0% +and if you want to take my course next +fall so we'll + + align:start position:0% +fall so we'll + + + align:start position:0% +fall so we'll +cover some of those okay if i'll say a + + align:start position:0% +cover some of those okay if i'll say a + + + align:start position:0% +cover some of those okay if i'll say a +little bit about the course + + align:start position:0% + + + + align:start position:0% + +so it's a basic it's a tqe level uh + + align:start position:0% +so it's a basic it's a tqe level uh + + + align:start position:0% +so it's a basic it's a tqe level uh +basic + + align:start position:0% +basic + + + align:start position:0% +basic +uh grad course we do synchronous + + align:start position:0% +uh grad course we do synchronous + + + align:start position:0% +uh grad course we do synchronous +asynchronous and some + + align:start position:0% +asynchronous and some + + + align:start position:0% +asynchronous and some +other stuff where the nodes really know + + align:start position:0% +other stuff where the nodes really know + + + align:start position:0% +other stuff where the nodes really know +about something about time + + align:start position:0% +about something about time + + + align:start position:0% +about something about time +um here's some of the synchronous + + align:start position:0% +um here's some of the synchronous + + + align:start position:0% +um here's some of the synchronous +problems some + + align:start position:0% +problems some + + + align:start position:0% +problems some +like the ones you've already seen but + + align:start position:0% +like the ones you've already seen but + + + align:start position:0% +like the ones you've already seen but +building many other kinds of structures + + align:start position:0% +building many other kinds of structures + + + align:start position:0% +building many other kinds of structures +in graphs and then we get into fall + + align:start position:0% +in graphs and then we get into fall + + + align:start position:0% +in graphs and then we get into fall +tolerance + + align:start position:0% +tolerance + + + align:start position:0% +tolerance +so there's a lot of questions about what + + align:start position:0% +so there's a lot of questions about what + + + align:start position:0% +so there's a lot of questions about what +happens when some of the + + align:start position:0% +happens when some of the + + + align:start position:0% +happens when some of the +components can fail or they're even + + align:start position:0% +components can fail or they're even + + + align:start position:0% +components can fail or they're even +malicious + + align:start position:0% +malicious + + + align:start position:0% +malicious +and you know you have to deal with the + + align:start position:0% +and you know you have to deal with the + + + align:start position:0% +and you know you have to deal with the +effects of of malicious + + align:start position:0% +effects of of malicious + + + align:start position:0% +effects of of malicious +processes in your system and then + + align:start position:0% +processes in your system and then + + + align:start position:0% +processes in your system and then +for asynchronous algorithms um we'll do + + align:start position:0% +for asynchronous algorithms um we'll do + + + align:start position:0% +for asynchronous algorithms um we'll do +not only + + align:start position:0% +not only + + + align:start position:0% +not only +individual problems like the ones you've + + align:start position:0% +individual problems like the ones you've + + + align:start position:0% +individual problems like the ones you've +just seen but there's some general + + align:start position:0% +just seen but there's some general + + + align:start position:0% +just seen but there's some general +techniques like synchronizers + + align:start position:0% +techniques like synchronizers + + + align:start position:0% +techniques like synchronizers +um notion of logical time that's um + + align:start position:0% +um notion of logical time that's um + + + align:start position:0% +um notion of logical time that's um +leslie lamport's first and biggest + + align:start position:0% +leslie lamport's first and biggest + + + align:start position:0% +leslie lamport's first and biggest +contribution he won the touring award + + align:start position:0% +contribution he won the touring award + + + align:start position:0% +contribution he won the touring award +last year other techniques like taking + + align:start position:0% +last year other techniques like taking + + + align:start position:0% +last year other techniques like taking +global snapshots of the of the entire + + align:start position:0% +global snapshots of the of the entire + + + align:start position:0% +global snapshots of the of the entire +system while it's running + + align:start position:0% +system while it's running + + + align:start position:0% +system while it's running +in addition to talking about networks as + + align:start position:0% +in addition to talking about networks as + + + align:start position:0% +in addition to talking about networks as +we've been doing this week + + align:start position:0% +we've been doing this week + + + align:start position:0% +we've been doing this week +we'll talk about shared memory + + align:start position:0% +we'll talk about shared memory + + + align:start position:0% +we'll talk about shared memory +multiprocessors + + align:start position:0% +multiprocessors + + + align:start position:0% +multiprocessors +accessing shared memory and + + align:start position:0% +accessing shared memory and + + + align:start position:0% +accessing shared memory and +solving problems that are of use in + + align:start position:0% +solving problems that are of use in + + + align:start position:0% +solving problems that are of use in +multiprocessors like mutual exclusion + + align:start position:0% +multiprocessors like mutual exclusion + + + align:start position:0% +multiprocessors like mutual exclusion +and again fault tolerance fault + + align:start position:0% +and again fault tolerance fault + + + align:start position:0% +and again fault tolerance fault +tolerance then + + align:start position:0% +tolerance then + + + align:start position:0% +tolerance then +gets us into a study of data objects + + align:start position:0% +gets us into a study of data objects + + + align:start position:0% +gets us into a study of data objects +with consistency conditions which is the + + align:start position:0% +with consistency conditions which is the + + + align:start position:0% +with consistency conditions which is the +sort of stuff that's + + align:start position:0% +sort of stuff that's + + + align:start position:0% +sort of stuff that's +useful in cloud computing if you want to + + align:start position:0% +useful in cloud computing if you want to + + + align:start position:0% +useful in cloud computing if you want to +have coherent access to data that's + + align:start position:0% +have coherent access to data that's + + + align:start position:0% +have coherent access to data that's +stored at many locations you need to + + align:start position:0% +stored at many locations you need to + + + align:start position:0% +stored at many locations you need to +have some + + align:start position:0% +have some + + + align:start position:0% +have some +um interesting distributed algorithms + + align:start position:0% +um interesting distributed algorithms + + + align:start position:0% +um interesting distributed algorithms +self-stabilization if you plunge your + + align:start position:0% +self-stabilization if you plunge your + + + align:start position:0% +self-stabilization if you plunge your +system into some arbitrary state and + + align:start position:0% +system into some arbitrary state and + + + align:start position:0% +system into some arbitrary state and +you'd like it to converge to a good + + align:start position:0% +you'd like it to converge to a good + + + align:start position:0% +you'd like it to converge to a good +state + + align:start position:0% +state + + + align:start position:0% +state +that's the topic of self-stabilization + + align:start position:0% +that's the topic of self-stabilization + + + align:start position:0% +that's the topic of self-stabilization +and depending on time there's things + + align:start position:0% +and depending on time there's things + + + align:start position:0% +and depending on time there's things +that use use time in the algorithms + + align:start position:0% +that use use time in the algorithms + + + align:start position:0% +that use use time in the algorithms +and the newer work that we're working on + + align:start position:0% +and the newer work that we're working on + + + align:start position:0% +and the newer work that we're working on +in research is very dynamic you have + + align:start position:0% +in research is very dynamic you have + + + align:start position:0% +in research is very dynamic you have +distributed algorithms where the network + + align:start position:0% +distributed algorithms where the network + + + align:start position:0% +distributed algorithms where the network +itself is changing during the execution + + align:start position:0% +itself is changing during the execution + + + align:start position:0% +itself is changing during the execution +that comes up in wireless networks and + + align:start position:0% +that comes up in wireless networks and + + + align:start position:0% +that comes up in wireless networks and +lately we're actually looking at insect + + align:start position:0% +lately we're actually looking at insect + + + align:start position:0% +lately we're actually looking at insect +colony algorithms + + align:start position:0% +colony algorithms + + + align:start position:0% +colony algorithms +where what distributed algorithms do + + align:start position:0% +where what distributed algorithms do + + + align:start position:0% +where what distributed algorithms do +ants use to + + align:start position:0% +ants use to + + + align:start position:0% +ants use to +decide on how to select a new nest when + + align:start position:0% +decide on how to select a new nest when + + + align:start position:0% +decide on how to select a new nest when +the researchers smash their old nest in + + align:start position:0% +the researchers smash their old nest in + + + align:start position:0% +the researchers smash their old nest in +the laboratory + + align:start position:0% +the laboratory + + + align:start position:0% +the laboratory +so that kind of question okay + + align:start position:0% +so that kind of question okay + + + align:start position:0% +so that kind of question okay +so so that's it for the distributed + + align:start position:0% +so so that's it for the distributed + + + align:start position:0% +so so that's it for the distributed +algorithms week + + align:start position:0% +algorithms week + + + align:start position:0% +algorithms week +and we'll see you next next week is um + + align:start position:0% +and we'll see you next next week is um + + + align:start position:0% +and we'll see you next next week is um +security okay yep + + align:start position:0% +security okay yep + + + align:start position:0% +security okay yep +whoa \ No newline at end of file diff --git a/Ehteu_SG3tI.txt b/Ehteu_SG3tI.txt new file mode 100644 index 0000000000000000000000000000000000000000..c5874475e92786f617d5741a7871f78722a88e2a --- /dev/null +++ b/Ehteu_SG3tI.txt @@ -0,0 +1,1789 @@ +align:start position:0% + +hi welcome to recitation today's problem + + align:start position:0% +hi welcome to recitation today's problem + + + align:start position:0% +hi welcome to recitation today's problem +is about change of bases it says the + + align:start position:0% +is about change of bases it says the + + + align:start position:0% +is about change of bases it says the +vector space of polinomial in X of + + align:start position:0% +vector space of polinomial in X of + + + align:start position:0% +vector space of polinomial in X of +degree up to two has a basis 1 x and x + + align:start position:0% +degree up to two has a basis 1 x and x + + + align:start position:0% +degree up to two has a basis 1 x and x +squ that's the obvious basis that you + + align:start position:0% +squ that's the obvious basis that you + + + align:start position:0% +squ that's the obvious basis that you +would write for that space Vector space + + align:start position:0% +would write for that space Vector space + + + align:start position:0% +would write for that space Vector space +but today we're going to consider + + align:start position:0% +but today we're going to consider + + + align:start position:0% +but today we're going to consider +another basis W1 W2 and W3 and we don't + + align:start position:0% +another basis W1 W2 and W3 and we don't + + + align:start position:0% +another basis W1 W2 and W3 and we don't +know what W1 W2 and W3 are explicitly + + align:start position:0% +know what W1 W2 and W3 are explicitly + + + align:start position:0% +know what W1 W2 and W3 are explicitly +what we know is that their values at X = + + align:start position:0% +what we know is that their values at X = + + + align:start position:0% +what we know is that their values at X = +Min -1 0 and 1 are given by this this + + align:start position:0% +Min -1 0 and 1 are given by this this + + + align:start position:0% +Min -1 0 and 1 are given by this this +table here so there are 1 0 0 0 1 0 and + + align:start position:0% +table here so there are 1 0 0 0 1 0 and + + + align:start position:0% +table here so there are 1 0 0 0 1 0 and +0 0 1 we're asked to do the following + + align:start position:0% +0 0 1 we're asked to do the following + + + align:start position:0% +0 0 1 we're asked to do the following +we're asked to express this polinomial + + align:start position:0% +we're asked to express this polinomial + + + align:start position:0% +we're asked to express this polinomial +so y of X is - x + 5 in this Bas is W1 + + align:start position:0% +so y of X is - x + 5 in this Bas is W1 + + + align:start position:0% +so y of X is - x + 5 in this Bas is W1 +W2 W3 we're asked to find the change of + + align:start position:0% +W2 W3 we're asked to find the change of + + + align:start position:0% +W2 W3 we're asked to find the change of +basis matrices between these two bases 1 + + align:start position:0% +basis matrices between these two bases 1 + + + align:start position:0% +basis matrices between these two bases 1 +x x² and W1 W2 W3 and finally we're + + align:start position:0% +x x² and W1 W2 W3 and finally we're + + + align:start position:0% +x x² and W1 W2 W3 and finally we're +asked to find the Matrix of taking + + align:start position:0% +asked to find the Matrix of taking + + + align:start position:0% +asked to find the Matrix of taking +derivatives which is a linear map on + + align:start position:0% +derivatives which is a linear map on + + + align:start position:0% +derivatives which is a linear map on +this space in both of these bases and + + align:start position:0% +this space in both of these bases and + + + align:start position:0% +this space in both of these bases and +let me give you an extra level of of of + + align:start position:0% +let me give you an extra level of of of + + + align:start position:0% +let me give you an extra level of of of +um challenge which is to try to do as + + align:start position:0% +um challenge which is to try to do as + + + align:start position:0% +um challenge which is to try to do as +much of this as possible without + + align:start position:0% +much of this as possible without + + + align:start position:0% +much of this as possible without +explicitly finding W1 W2 and W3 uh I'll + + align:start position:0% +explicitly finding W1 W2 and W3 uh I'll + + + align:start position:0% +explicitly finding W1 W2 and W3 uh I'll +let you think about the problem and then + + align:start position:0% +let you think about the problem and then + + + align:start position:0% +let you think about the problem and then +you can come back and compare Your + + align:start position:0% +you can come back and compare Your + + + align:start position:0% +you can come back and compare Your +solution with mine + + align:start position:0% + + + + align:start position:0% + +hi welcome back + + align:start position:0% + + + + align:start position:0% + +so to start with a problem a we need to + + align:start position:0% + + + + align:start position:0% + +find we need to find coefficients + + align:start position:0% + + + + align:start position:0% + +Alpha + + align:start position:0% + + + + align:start position:0% + +Beta And GMA + + align:start position:0% + + + + align:start position:0% + +so that y of X is expressed through with + + align:start position:0% +so that y of X is expressed through with + + + align:start position:0% +so that y of X is expressed through with +this coefficients in this new basis W1 + + align:start position:0% +this coefficients in this new basis W1 + + + align:start position:0% +this coefficients in this new basis W1 +W2 and W3 now one way to do that would + + align:start position:0% +W2 and W3 now one way to do that would + + + align:start position:0% +W2 and W3 now one way to do that would +be to look at this look at this table of + + align:start position:0% +be to look at this look at this table of + + + align:start position:0% +be to look at this look at this table of +values explicitly find W1 W2 and W3 so a + + align:start position:0% +values explicitly find W1 W2 and W3 so a + + + align:start position:0% +values explicitly find W1 W2 and W3 so a +quadratic polinomial is um all the + + align:start position:0% +quadratic polinomial is um all the + + + align:start position:0% +quadratic polinomial is um all the +information we need about it is in three + + align:start position:0% +information we need about it is in three + + + align:start position:0% +information we need about it is in three +Val is in values at three points so say + + align:start position:0% +Val is in values at three points so say + + + align:start position:0% +Val is in values at three points so say +W1 is A1 Plus B * X plus C * um x^2 find + + align:start position:0% +W1 is A1 Plus B * X plus C * um x^2 find + + + align:start position:0% +W1 is A1 Plus B * X plus C * um x^2 find +a b and c find W1 W2 W3 explicitly and + + align:start position:0% +a b and c find W1 W2 W3 explicitly and + + + align:start position:0% +a b and c find W1 W2 W3 explicitly and +then go back to this system and try to + + align:start position:0% +then go back to this system and try to + + + align:start position:0% +then go back to this system and try to +find it and try to find alpha beta and + + align:start position:0% +find it and try to find alpha beta and + + + align:start position:0% +find it and try to find alpha beta and +gamma however there's a trick let's try + + align:start position:0% +gamma however there's a trick let's try + + + align:start position:0% +gamma however there's a trick let's try +to do let's try to see if we can do it + + align:start position:0% +to do let's try to see if we can do it + + + align:start position:0% +to do let's try to see if we can do it +without finding W1 W2 and W3 explicitly + + align:start position:0% +without finding W1 W2 and W3 explicitly + + + align:start position:0% +without finding W1 W2 and W3 explicitly +so let me try to see what are the values + + align:start position:0% +so let me try to see what are the values + + + align:start position:0% +so let me try to see what are the values +of Y at these points so Y is - x + 5 so + + align:start position:0% +of Y at these points so Y is - x + 5 so + + + align:start position:0% +of Y at these points so Y is - x + 5 so +the values are six + + align:start position:0% +the values are six + + + align:start position:0% +the values are six + + align:start position:0% + + + align:start position:0% +5 and + + align:start position:0% +5 and + + + align:start position:0% +5 and +four and let me instead of considering + + align:start position:0% +four and let me instead of considering + + + align:start position:0% +four and let me instead of considering +this this equation let me evaluate it at + + align:start position:0% +this this equation let me evaluate it at + + + align:start position:0% +this this equation let me evaluate it at +X is minus one x + + align:start position:0% +X is minus one x + + + align:start position:0% +X is minus one x +is0 and x is + + align:start position:0% +is0 and x is + + + align:start position:0% +is0 and x is +one what I get through this + + align:start position:0% +one what I get through this + + + align:start position:0% +one what I get through this +is + + align:start position:0% +is + + + align:start position:0% +is +that w at at minus one um actually let + + align:start position:0% +that w at at minus one um actually let + + + align:start position:0% +that w at at minus one um actually let +me write this + + align:start position:0% + + + + align:start position:0% + +I get that W minus1 which is a number + + align:start position:0% +I get that W minus1 which is a number + + + align:start position:0% +I get that W minus1 which is a number +equals Alpha * + + align:start position:0% +equals Alpha * + + + align:start position:0% +equals Alpha * +W1 at Min -1 which is a number plus beta + + align:start position:0% +W1 at Min -1 which is a number plus beta + + + align:start position:0% +W1 at Min -1 which is a number plus beta +* W2 at minus1 plus GMA * + + align:start position:0% +* W2 at minus1 plus GMA * + + + align:start position:0% +* W2 at minus1 plus GMA * +W3 at minus + + align:start position:0% +W3 at minus + + + align:start position:0% +W3 at minus +one and similarly at + + align:start position:0% + + + + align:start position:0% + +zero and similarly at one and now let me + + align:start position:0% +zero and similarly at one and now let me + + + align:start position:0% +zero and similarly at one and now let me +think of this as a linear system that + + align:start position:0% +think of this as a linear system that + + + align:start position:0% +think of this as a linear system that +has unknowns alpha beta and gamma + + align:start position:0% +has unknowns alpha beta and gamma + + + align:start position:0% +has unknowns alpha beta and gamma +coefficient these values here at + + align:start position:0% +coefficient these values here at + + + align:start position:0% +coefficient these values here at +minus10 and 1 and the right hand side + + align:start position:0% +minus10 and 1 and the right hand side + + + align:start position:0% +minus10 and 1 and the right hand side +well what's written here on the left + + align:start position:0% +well what's written here on the left + + + align:start position:0% +well what's written here on the left +hand side Y at minus one Y at zero and Y + + align:start position:0% +hand side Y at minus one Y at zero and Y + + + align:start position:0% +hand side Y at minus one Y at zero and Y +at + + align:start position:0% +at + + + align:start position:0% +at +one if you write + + align:start position:0% +one if you write + + + align:start position:0% +one if you write +this in a matrix and read off + + align:start position:0% +this in a matrix and read off + + + align:start position:0% +this in a matrix and read off +coefficients from there you get the + + align:start position:0% +coefficients from there you get the + + + align:start position:0% +coefficients from there you get the +following system + + align:start position:0% + + + + align:start position:0% + +so this is the Matrix of the system read + + align:start position:0% +so this is the Matrix of the system read + + + align:start position:0% +so this is the Matrix of the system read +of from + + align:start position:0% +of from + + + align:start position:0% +of from +here these are the + + align:start position:0% + + + + align:start position:0% + +unknowns and these are the + + align:start position:0% + + + + align:start position:0% + +values of the right hand side and I hope + + align:start position:0% +values of the right hand side and I hope + + + align:start position:0% +values of the right hand side and I hope +you'll agree that this is a very easy + + align:start position:0% +you'll agree that this is a very easy + + + align:start position:0% +you'll agree that this is a very easy +system to solve we just get Alpha is 6 + + align:start position:0% +system to solve we just get Alpha is 6 + + + align:start position:0% +system to solve we just get Alpha is 6 +beta is 5 and GMA is four so the + + align:start position:0% +beta is 5 and GMA is four so the + + + align:start position:0% +beta is 5 and GMA is four so the +solution to the first part is y equal + + align:start position:0% +solution to the first part is y equal + + + align:start position:0% +solution to the first part is y equal + + align:start position:0% + + + align:start position:0% +W1 + 5 + + align:start position:0% +W1 + 5 + + + align:start position:0% +W1 + 5 +W2 + 4 + + align:start position:0% +W2 + 4 + + + align:start position:0% +W2 + 4 +W3 and let's notice another thing no + + align:start position:0% +W3 and let's notice another thing no + + + align:start position:0% +W3 and let's notice another thing no +matter what we what values we put here + + align:start position:0% +matter what we what values we put here + + + align:start position:0% +matter what we what values we put here +this Matrix is always going to stay the + + align:start position:0% +this Matrix is always going to stay the + + + align:start position:0% +this Matrix is always going to stay the +same it's only the right hand side + + align:start position:0% +same it's only the right hand side + + + align:start position:0% +same it's only the right hand side +that's going to change so if we're given + + align:start position:0% +that's going to change so if we're given + + + align:start position:0% +that's going to change so if we're given +any other polinomial now to express in a + + align:start position:0% +any other polinomial now to express in a + + + align:start position:0% +any other polinomial now to express in a +basis W1 W2 and W3 we don't have to do + + align:start position:0% +basis W1 W2 and W3 we don't have to do + + + align:start position:0% +basis W1 W2 and W3 we don't have to do +any thinking we don't have to do any + + align:start position:0% +any thinking we don't have to do any + + + align:start position:0% +any thinking we don't have to do any +computations what we do is go back to + + align:start position:0% +computations what we do is go back to + + + align:start position:0% +computations what we do is go back to +our table at the beginning and just read + + align:start position:0% +our table at the beginning and just read + + + align:start position:0% +our table at the beginning and just read +off let's go back to the table and just + + align:start position:0% +off let's go back to the table and just + + + align:start position:0% +off let's go back to the table and just +read off this values so in this case Y + + align:start position:0% +read off this values so in this case Y + + + align:start position:0% +read off this values so in this case Y +is 6 * W1 5 * W2 and 3 * + + align:start position:0% +is 6 * W1 5 * W2 and 3 * + + + align:start position:0% +is 6 * W1 5 * W2 and 3 * +W3 and that's already a hint to solving + + align:start position:0% +W3 and that's already a hint to solving + + + align:start position:0% +W3 and that's already a hint to solving +the B part which is find the change of + + align:start position:0% +the B part which is find the change of + + + align:start position:0% +the B part which is find the change of +basis matrices between 1 x x^2 and W1 W2 + + align:start position:0% +basis matrices between 1 x x^2 and W1 W2 + + + align:start position:0% +basis matrices between 1 x x^2 and W1 W2 +W3 change of basis matrices means + + align:start position:0% +W3 change of basis matrices means + + + align:start position:0% +W3 change of basis matrices means +expressing one basis in terms of another + + align:start position:0% +expressing one basis in terms of another + + + align:start position:0% +expressing one basis in terms of another +so as a part part of the problem we will + + align:start position:0% +so as a part part of the problem we will + + + align:start position:0% +so as a part part of the problem we will +have to express 1 x and x2 in terms of + + align:start position:0% +have to express 1 x and x2 in terms of + + + align:start position:0% +have to express 1 x and x2 in terms of +W1 W2 and W3 so let's just find their + + align:start position:0% +W1 W2 and W3 so let's just find their + + + align:start position:0% +W1 W2 and W3 so let's just find their +values at these three points one is a + + align:start position:0% +values at these three points one is a + + + align:start position:0% +values at these three points one is a +constant it just takes value one + + align:start position:0% +constant it just takes value one + + + align:start position:0% +constant it just takes value one +everywhere X takes value minus one at + + align:start position:0% +everywhere X takes value minus one at + + + align:start position:0% +everywhere X takes value minus one at +minus one 0 at 0 and one at 1 and X squ + + align:start position:0% +minus one 0 at 0 and one at 1 and X squ + + + align:start position:0% +minus one 0 at 0 and one at 1 and X squ +takes values 1 0 and 1 at minus one 0 + + align:start position:0% +takes values 1 0 and 1 at minus one 0 + + + align:start position:0% +takes values 1 0 and 1 at minus one 0 +and + + align:start position:0% +and + + + align:start position:0% +and +one and from this we can already + + align:start position:0% +one and from this we can already + + + align:start position:0% +one and from this we can already +conclude let's go the B here we can + + align:start position:0% +conclude let's go the B here we can + + + align:start position:0% +conclude let's go the B here we can +conclude that 1 equal W1 + W2 + + + align:start position:0% +conclude that 1 equal W1 + W2 + + + + align:start position:0% +conclude that 1 equal W1 + W2 + +W3 that x equals um - W1 + W3 and that + + align:start position:0% +W3 that x equals um - W1 + W3 and that + + + align:start position:0% +W3 that x equals um - W1 + W3 and that +x^2 = + + align:start position:0% +x^2 = + + + align:start position:0% +x^2 = +W1 + + + align:start position:0% +W1 + + + + align:start position:0% +W1 + +W3 and from this we can immediately + + align:start position:0% +W3 and from this we can immediately + + + align:start position:0% +W3 and from this we can immediately +write one change of basis Matrix + + align:start position:0% + + + + align:start position:0% + +namely since we know how to express One + + align:start position:0% +namely since we know how to express One + + + align:start position:0% +namely since we know how to express One +X and X squ in terms of W1 + + align:start position:0% +X and X squ in terms of W1 + + + align:start position:0% +X and X squ in terms of W1 +W2 and W3 we can just copy this + + align:start position:0% +W2 and W3 we can just copy this + + + align:start position:0% +W2 and W3 we can just copy this +information over to this Matrix getting + + align:start position:0% +information over to this Matrix getting + + + align:start position:0% +information over to this Matrix getting +1 1 1 - 1 0 1 and 1 0 one so which + + align:start position:0% +1 1 1 - 1 0 1 and 1 0 one so which + + + align:start position:0% +1 1 1 - 1 0 1 and 1 0 one so which +Matrix is this this is a matrix so so we + + align:start position:0% +Matrix is this this is a matrix so so we + + + align:start position:0% +Matrix is this this is a matrix so so we +have 1 x and x squar um expressed in + + align:start position:0% +have 1 x and x squar um expressed in + + + align:start position:0% +have 1 x and x squar um expressed in +terms of W1 W2 and W3 so if we feed this + + align:start position:0% +terms of W1 W2 and W3 so if we feed this + + + align:start position:0% +terms of W1 W2 and W3 so if we feed this +Matrix something expressed in the bases + + align:start position:0% +Matrix something expressed in the bases + + + align:start position:0% +Matrix something expressed in the bases +1 x and x squ say a b and c what it's + + align:start position:0% +1 x and x squ say a b and c what it's + + + align:start position:0% +1 x and x squ say a b and c what it's +going to throw out is the same + + align:start position:0% +going to throw out is the same + + + align:start position:0% +going to throw out is the same +polinomial expressed in this basis here + + align:start position:0% +polinomial expressed in this basis here + + + align:start position:0% +polinomial expressed in this basis here +W1 W2 and W3 so I'm going to just write + + align:start position:0% +W1 W2 and W3 so I'm going to just write + + + align:start position:0% +W1 W2 and W3 so I'm going to just write +that this is + + align:start position:0% + + + + align:start position:0% + +a a matrix of this basis change + + align:start position:0% + + + + align:start position:0% + +okay how do we get the other one well + + align:start position:0% +okay how do we get the other one well + + + align:start position:0% +okay how do we get the other one well +very + + align:start position:0% +very + + + align:start position:0% +very +easy we know it's just the + + align:start position:0% +easy we know it's just the + + + align:start position:0% +easy we know it's just the +inverse of a so this is going to + + align:start position:0% +inverse of a so this is going to + + + align:start position:0% +inverse of a so this is going to +be the + + align:start position:0% + + + + align:start position:0% + +Matrix that takes + + align:start position:0% + + + + align:start position:0% + +something written in this basis and + + align:start position:0% +something written in this basis and + + + align:start position:0% +something written in this basis and +transfers it to this basis I'm not going + + align:start position:0% +transfers it to this basis I'm not going + + + align:start position:0% +transfers it to this basis I'm not going +to calculate the inverse of a matrix in + + align:start position:0% +to calculate the inverse of a matrix in + + + align:start position:0% +to calculate the inverse of a matrix in +front of you instead I'm going to + + align:start position:0% +front of you instead I'm going to + + + align:start position:0% +front of you instead I'm going to +consult my + + align:start position:0% +consult my + + + align:start position:0% +consult my +Oracle sorry about + + align:start position:0% +Oracle sorry about + + + align:start position:0% +Oracle sorry about +that and my Oracle says that the inverse + + align:start position:0% +that and my Oracle says that the inverse + + + align:start position:0% +that and my Oracle says that the inverse +should be 0 1 + + align:start position:0% +should be 0 1 + + + align:start position:0% +should be 0 1 +0 um Min - 12 0 1 12 + + align:start position:0% +0 um Min - 12 0 1 12 + + + align:start position:0% +0 um Min - 12 0 1 12 +and 12 minus one + + align:start position:0% +and 12 minus one + + + align:start position:0% +and 12 minus one +12 and that solves the B + + align:start position:0% +12 and that solves the B + + + align:start position:0% +12 and that solves the B +part let's go on to the C part the C + + align:start position:0% +part let's go on to the C part the C + + + align:start position:0% +part let's go on to the C part the C +part required us to find the Matrix of + + align:start position:0% +part required us to find the Matrix of + + + align:start position:0% +part required us to find the Matrix of +taking derivatives which is a linear map + + align:start position:0% +taking derivatives which is a linear map + + + align:start position:0% +taking derivatives which is a linear map +on the spa on the space of polinomial in + + align:start position:0% +on the spa on the space of polinomial in + + + align:start position:0% +on the spa on the space of polinomial in +both of these + + align:start position:0% +both of these + + + align:start position:0% +both of these +bases so let's first do the One X X squ + + align:start position:0% +bases so let's first do the One X X squ + + + align:start position:0% +bases so let's first do the One X X squ +basis because that one's + + align:start position:0% +basis because that one's + + + align:start position:0% +basis because that one's +easier I'm going to call it + + align:start position:0% + + + + align:start position:0% + +DX so I'm going to work in basis 1 x X2 + + align:start position:0% +DX so I'm going to work in basis 1 x X2 + + + align:start position:0% +DX so I'm going to work in basis 1 x X2 +and what I want to what I want to + + align:start position:0% +and what I want to what I want to + + + align:start position:0% +and what I want to what I want to +express is the transformation of taking + + align:start position:0% +express is the transformation of taking + + + align:start position:0% +express is the transformation of taking +derivatives so here I'm going to write + + align:start position:0% +derivatives so here I'm going to write + + + align:start position:0% +derivatives so here I'm going to write +the vector to which taking derivatives + + align:start position:0% +the vector to which taking derivatives + + + align:start position:0% +the vector to which taking derivatives +Maps the polinomial one which is + + align:start position:0% +Maps the polinomial one which is + + + align:start position:0% +Maps the polinomial one which is +zero and that's this expressed in the + + align:start position:0% +zero and that's this expressed in the + + + align:start position:0% +zero and that's this expressed in the +basis 1 x + + align:start position:0% +basis 1 x + + + align:start position:0% +basis 1 x +x^2 in the second column I'm going to + + align:start position:0% +x^2 in the second column I'm going to + + + align:start position:0% +x^2 in the second column I'm going to +write X Prime the the vector to which DX + + align:start position:0% +write X Prime the the vector to which DX + + + align:start position:0% +write X Prime the the vector to which DX +send the vector X and that's equal to + + align:start position:0% +send the vector X and that's equal to + + + align:start position:0% +send the vector X and that's equal to +one which expressed in this basis is one + + align:start position:0% +one which expressed in this basis is one + + + align:start position:0% +one which expressed in this basis is one +0 0 and here I'm going to write x 2 x^2 + + align:start position:0% +0 0 and here I'm going to write x 2 x^2 + + + align:start position:0% +0 0 and here I'm going to write x 2 x^2 +Prime which is 2x which expressed in + + align:start position:0% +Prime which is 2x which expressed in + + + align:start position:0% +Prime which is 2x which expressed in +this + + align:start position:0% +this + + + align:start position:0% +this +basis is just + + align:start position:0% +basis is just + + + align:start position:0% +basis is just +this okay that one was easy for the + + align:start position:0% +this okay that one was easy for the + + + align:start position:0% +this okay that one was easy for the +other one well we could calculate W1 W2 + + align:start position:0% +other one well we could calculate W1 W2 + + + align:start position:0% +other one well we could calculate W1 W2 +W3 explicitly take their derivatives go + + align:start position:0% +W3 explicitly take their derivatives go + + + align:start position:0% +W3 explicitly take their derivatives go +back to the table and try to find and + + align:start position:0% +back to the table and try to find and + + + align:start position:0% +back to the table and try to find and +repeat the procedure that we did already + + align:start position:0% +repeat the procedure that we did already + + + align:start position:0% +repeat the procedure that we did already +so expressing these derivatives in terms + + align:start position:0% +so expressing these derivatives in terms + + + align:start position:0% +so expressing these derivatives in terms +of W1 W2 W3 and that's a lot of work but + + align:start position:0% +of W1 W2 W3 and that's a lot of work but + + + align:start position:0% +of W1 W2 W3 and that's a lot of work but +we pretty much already did most of this + + align:start position:0% +we pretty much already did most of this + + + align:start position:0% +we pretty much already did most of this +work so we know how to take derivatives + + align:start position:0% +work so we know how to take derivatives + + + align:start position:0% +work so we know how to take derivatives +in this basis and we know how to go + + align:start position:0% +in this basis and we know how to go + + + align:start position:0% +in this basis and we know how to go +between these two bases so if we want to + + align:start position:0% +between these two bases so if we want to + + + align:start position:0% +between these two bases so if we want to +take a derivative of something written + + align:start position:0% +take a derivative of something written + + + align:start position:0% +take a derivative of something written +in the basis W1 W2 W3 well let's + + align:start position:0% + + + + align:start position:0% + +first write this something in basis 1 x + + align:start position:0% +first write this something in basis 1 x + + + align:start position:0% +first write this something in basis 1 x +x^2 then let's take a derivative of + + align:start position:0% +x^2 then let's take a derivative of + + + align:start position:0% +x^2 then let's take a derivative of +it and then let's write it back in the + + align:start position:0% +it and then let's write it back in the + + + align:start position:0% +it and then let's write it back in the +original basis that we want so it's + + align:start position:0% +original basis that we want so it's + + + align:start position:0% +original basis that we want so it's +multiplication of three + + align:start position:0% +multiplication of three + + + align:start position:0% +multiplication of three +matrices we have all three matrix + + align:start position:0% +matrices we have all three matrix + + + align:start position:0% +matrices we have all three matrix +multiplication is easy and my Oracle + + align:start position:0% +multiplication is easy and my Oracle + + + align:start position:0% +multiplication is easy and my Oracle +again says that this should be - 3 over + + align:start position:0% +again says that this should be - 3 over + + + align:start position:0% +again says that this should be - 3 over +2 2 - 1 / + + align:start position:0% +2 2 - 1 / + + + align:start position:0% +2 2 - 1 / +2 - 1 / 2 0 1 / 2 and 1 / 2 - + + align:start position:0% +2 - 1 / 2 0 1 / 2 and 1 / 2 - + + + align:start position:0% +2 - 1 / 2 0 1 / 2 and 1 / 2 - +2 3 + + align:start position:0% +2 3 + + + align:start position:0% +2 3 +over2 and that solves the problem + + align:start position:0% +over2 and that solves the problem + + + align:start position:0% +over2 and that solves the problem +now one thing that I would want to + + align:start position:0% +now one thing that I would want to + + + align:start position:0% +now one thing that I would want to +discuss in the end is how did we do with + + align:start position:0% +discuss in the end is how did we do with + + + align:start position:0% +discuss in the end is how did we do with +respect to my challenge which was let's + + align:start position:0% +respect to my challenge which was let's + + + align:start position:0% +respect to my challenge which was let's +try to do as much of it as possible + + align:start position:0% +try to do as much of it as possible + + + align:start position:0% +try to do as much of it as possible +without finding W1 W2 and W3 explicitly + + align:start position:0% +without finding W1 W2 and W3 explicitly + + + align:start position:0% +without finding W1 W2 and W3 explicitly +and it seems like we did really well + + align:start position:0% +and it seems like we did really well + + + align:start position:0% +and it seems like we did really well +there's nowhere on the board written W1 + + align:start position:0% +there's nowhere on the board written W1 + + + align:start position:0% +there's nowhere on the board written W1 +equals W2 equals and W3 equals but is it + + align:start position:0% +equals W2 equals and W3 equals but is it + + + align:start position:0% +equals W2 equals and W3 equals but is it +really so it's not we calculated the + + align:start position:0% +really so it's not we calculated the + + + align:start position:0% +really so it's not we calculated the +Matrix of a inverse here and what this + + align:start position:0% +Matrix of a inverse here and what this + + + align:start position:0% +Matrix of a inverse here and what this +really means is that W1 W2 and W3 + + align:start position:0% +really means is that W1 W2 and W3 + + + align:start position:0% +really means is that W1 W2 and W3 +written in the basis 1 x and x^2 are as + + align:start position:0% +written in the basis 1 x and x^2 are as + + + align:start position:0% +written in the basis 1 x and x^2 are as +follows W1 is - 12 x +2 x^2 W2 is 1 - + + align:start position:0% +follows W1 is - 12 x +2 x^2 W2 is 1 - + + + align:start position:0% +follows W1 is - 12 x +2 x^2 W2 is 1 - +x^2 and W3 is 12 x +2 x^2 so you can + + align:start position:0% +x^2 and W3 is 12 x +2 x^2 so you can + + + align:start position:0% +x^2 and W3 is 12 x +2 x^2 so you can +check your work with with the help of + + align:start position:0% +check your work with with the help of + + + align:start position:0% +check your work with with the help of +this Matrix in case you did find W1 W2 + + align:start position:0% +this Matrix in case you did find W1 W2 + + + align:start position:0% +this Matrix in case you did find W1 W2 +and W3 explicitly and that's all I + + align:start position:0% +and W3 explicitly and that's all I + + + align:start position:0% +and W3 explicitly and that's all I +wanted to say today \ No newline at end of file diff --git a/EsiGSf2bt9k.txt b/EsiGSf2bt9k.txt new file mode 100644 index 0000000000000000000000000000000000000000..e0e7673b2d82ec0635fca59d0c02407e96d3d8f8 --- /dev/null +++ b/EsiGSf2bt9k.txt @@ -0,0 +1,4137 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high-quality educational +resources for free. + +To make a donation or view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at MIT.edu. + +PROFESSOR: Ladies and gentlemen, +welcome to this + +lecture on non-linear finite +element analysis of solids and + +structures. + +In this lecture, I'd like to +continue with our discussion + +of structural elements, and +in particular, I'd like to + +concentrate our attention first +on the formulation of + +beam elements. + +After that, I'd like to talk +more about the formulation of + +shell elements, and then +show you applications. + +When we talk about beam +elements, we might think about + +the usual Hermitian beam +elements, in which the + +transverse placements cubically +interpolated, and + +the longitudinal displacements +are linearly interpolated. + +This is an element that is +usually used in linear + +analysis, and very +widely used-- + +you might have used it quite +a bit yourself-- + +and it is also very effective +in the analysis of linear + +response of structures. + +However, in my discussion now, +I will talk about the + +isoparametric beam element, +and how we formulate the + +isoparametric beam element, in +other words, and how we apply + +it in the analysis +of structures. + +So when I talk about the beam +element, I really mean this + +isoparametric beam element that +we are formulating in + +this lecture. + +The isoparametric beam +formulation can be very + +effective for the analysis of +curve themes, for the analysis + +of geometrically nonlinear +problems, and for the analysis + +of stiffened shell structures, +where we couple the + +isoparametric beam with the +isoparametrically formulated + +shell elements. + +The formulation is quite +analogous to the formulation + +of the isoparametric degenerate +shell elements that + +we discussed in the previous +lecture, and so we can go a + +bit fast over the formulation +of the beam element here. + +I'm showing a typical +beam element, + +rectangular cross section. + +Here we show three nodes. + +Actually, the beam element can +be used with two nodes, three + +nodes, or four nodes, as we will +discuss further later on. + +We notice that the depth off +the element is ak, the + +thickness of the +element is bk. + +And notice that at these nodes, +we measure certain + +nodal point variables. + +and here I'm showing the nodal +point variables that we do + +measure at the nodes. + +Three displacements, incremental +displacements, and + +three incremental rotations. + +Notice that the description of +the beam element follows much + +the same as the geometric +description of the beam + +element follows, much the same +way as we are dealing with the + +shell element. + +We introduce director vectors. + +Now we have two director +vectors. + +In the shell, of course, +we had only one + +director vector per node. + +Now we have two. + +Here we show tvsk, the director +vector at time t into + +the S-direction, corresponding +to node k. + +Notice here tvtk. + +The director vector at time t +corresponding to node k into + +the t direction. + +this t means direction t that +t opting out means time t + +Notice that corresponding to +this direction t here, we have + +the t isoparametric +coordinate. + +And of course, this t +isoparametric coordinate also + +runs into the thickness ak. + +Notice that corresponding to +bk, we have the s-direction + +coordinate, and that s-direction +coordinate, + +s-isoparametric coordinate, runs +into the direction of the + +director vector, tvsk. + +So these are the variables used +to describe the geometry + +and the displacement of +the beam element. + +We start with the general +equation for the + +geometry at time t. + +Here we have txi. + +The coordinates of a material +particle within the + +element at time t-- + +and remember, these are the +coordinates measured in the + +stationary coordinate system. + +And these coordinates are +obtained as shown on the + +right-hand side. + +Let's have a close look +at what we see on + +the right-hand side. + +We have the hk interpolation +function. + +This is the interpolation +function corresponding to the + +r-direction running through +the nodes of the element, + +along the mid-surface +of the element. + +And it's a one-dimensional +interpolation function, the + +same one that we used to see +for the truss element. + +These are the nodal point +coordinates at time t. + +We are summing over all the +nodal points, k from 1 to n, + +and n can be equal to 2, 3, or +4, as I mentioned earlier. + +Then we add to this term a term +that comes in because of + +the sickness of the beam into +the t-direction, ak, thickness + +off the beam into the +t-direction-- + +here is a t-coordinate. + +The isoparametric coordinates +going from minus 1 to plus 1. + +Here we have hk, same +interpolation function as + +there, and here we have the +direction, cosines of the + +director vector in the +t-direction at time t. + +A similar term, similar to this +one, is added for the + +f-direction. + +s, the isoparametric coordinate, +running from minus + +1 to plus 1, bk being the +thickness into the s-direction + +at node k, hk, same +interpolation function that we + +have seen up here already, and +these are the direction + +cosines of the director vector +in the s-direction, + +corresponding to node +k at time t. + +This equation is very similar +to the equation that we used + +in the shell element +formation. + +Of course, in the shell element +formulation, we + +interpolated here in a +two-dimensional domain over + +the shell mid-surface. + +Now we only run along the +neutral axis of the beam. + +And we had only one term in the +shell corresponding to the + +director vector. + +There was only one direction, +namely, the one normal to the + +mid-surface of the shell. + +Here we have two directions +to deal with. + +Since the displacements can +directly be obtained from the + +geometry interpolation at time +t minus the geometry + +interpolation at time 0, +of course this geometry + +interpolation is obtained by +simply substituting in the + +equation that we just looked +at for time t, the time 0. + +Since we obtain tui, as shown +here, this is the result. + +We simply apply our geometry +interpolation at time t, and + +at time 0, subtract. + +This is what you get on +the right-hand side. + +Nodal point displacement from +time 0 to time t, measured in + +the stationary global Cartesian +coordinate system. + +Here change in the director +vector cosines, or I should + +say, more precisely maybe, the +change in the cosine of the + +angle director vector time 0, +director vector time t. + +Of course, remember here we +have direction cosines + +corresponding to time t. + +Here we have direction cosines +corresponding to time 0. + +We subtract, and that +goes in here. + +Here, same kind of term, +but for direction s. + +Also the incremental +displacements are obtained + +from this relationship here, and +if you apply the geometry + +interpolation at time t plus +delta t and at time t, you + +directly obtain this +right-hand side. + +These are the increment in the +direction cosine from time t + +to time t plus delta t of the +director vector in the + +t-direction. + +Similar here for the +s-direction. + +Of course, we are used very well +to deal with increment + +and nodal point displacement, +but we cannot very well deal + +with these quantities +here, vti and vsi. + +We want to deal with nodal +point rotation. + +And so what we do is, we express +this quantity and that + +quantity in terms of nodal +point rotations, and that + +those expressions are +given down here. + +These are the two expressions. + +You can simply multiply out, and +you would immediately see + +that they indeed hold. + +With these geometry and +displacement interpolations + +established, we can now +directly calculate or + +establish the strain +displacement matrices + +corresponding to the Cartesian +strain components, and then a + +simple transformation, standard +transformation gives + +us the strain displacement +matrices corresponding to the + +eta zeta psi directions. + +Of course, these are the +directions with the components + +of strains and stresses that we +need to deal with for the + +beam formulation. + +Notice that zeta here is a +physical coordinate running + +into the direction, so to say, +of the a thickness of the + +beam, and zeta corresponds to +the t-isoparametric coordinate + +that we just talked about. + +Psi here corresponds to the +s-isoparametric coordinate, + +and runs into the b width, +so to say, of the beam. + +Eta here corresponds to the +r-isoparametric coordinate. + +Of course, these zeta, eta, and +psi are actual physical + +coordinates that we +are dealing with. + +We have to, of course, calculate +the tau psi eta, the + +tau eta eta, and the tau vita +psi stress components and + +corresponding strain components +for the beam + +formulation. + +And the stress-strain law, +corresponding to these + +components, is given here. + +Notice tau eta eta is obtained +by taking the Young's modulus + +and multiplying the Young's +modulus by epsilon + +eta eta, and so on. + +Notice here we have one share +component and another share + +component corresponding to this +column and corresponding + +to that column, and here we +have k factor, the share + +correction factor, that we +already used from the shell + +analysis formulation that +we discussed earlier. + +Notice that via the same +approach, we can also directly + +obtain a beam element for + +elastoplastic and creep analysis. + +In this particular case, of +course, the only stress + +component that would be non-zero +again would be tau + +eta eta, tau eta zeta, +and tau eta psi. + +The approach here is very +similar to what we have + +discussed earlier regarding the +shell element formation. + +There is one important point +in the beam element + +formulation. + +Namely that with the kinematic +assumptions used so far for + +the beam element, we do not +allow cross-sectional + +out-of-plane displacement. + +We do not allow warping. + +Our interpolation does not +contain the effect of warping. + +In torsion or loading, however, +we know that warping + +is very important, and for that +reason, we need to amend + +our displacement assumptions +by two or more displacement + +patterns, so to say. + +We allow these displacements to +take place in the element. + +u eta is equal to alpha +times psi beta. + +This is the exact warping +displacement for infinitely + +narrow sections. + +And this term here, with beta +a constant, is the exact + +warping displacement for +a square cross section. + +Now the actual section might +not be infinitely narrow, + +might not be square, but we can +easily test, and I will + +show you just now an example +of that in fact, a + +superposition of these functions +and the evaluation + +of alpha and beta by static +condensation actually yields + +good results, even for +cross-sections that are not + +infinitely narrow, and that +are not exactly square. + +Let's look at an example, +linear elasticity. + +If we take a section and simply +put it into torsion + +with b/a equal to 1, the +analytical value given by + +Timoshenko for this k constant +here in that formula is 0.141. + +And we obtain with +this formulation + +exactly that same value. + +We need to get it, because we +have embedded the proper + +interpolation for u eta into +our formulation, and then u + +static condensation, of course, +to condense out these + +two constants, alpha and beta, +that I just talked about. + +For b/a, a very large, very +narrow section, we also get + +the exact result in our finite +element solution, the exact + +analytical result. + +In between, we have a small +arrow, an arrow that, however, + +we believe is quite +acceptable. + +Let's look at one example that +I'd like to show you the + +results of. + +You might be interested +in this example. + +Here we have a narrow ring. + +Here you have a plan view of +that ring with the dimensions + +given, and Young's modulus and +Poisson's ratio given for that + +ring, subject to these +bending moments. + +Of course, the twisting +capability or capacity of the + +beam is of utmost importance +now, has to be properly + +modelled under this +loading condition. + +The model that we use +to analyze the + +problem is shown here. + +And you can see, at one side of +the ring, we have fixed it, + +and at the other side, +we prescribed a + +rotation, see eta x. + +We use here four node +elements as shown. + +This analysis was actually +inspired by us looking around + +in our office and seeing a +magnetic tape lying there. + +And if you look around, you +might have yourself a magnetic + +tape there. + +And you pick up this little ring +from the magnetic tape. + +And here I'd like to just +demonstrate to you briefly + +what we are doing. + +You see here, we have this ring, +much alike of what I've + +shown you on the view graph. + +I'm fixing it on the one side, +and on my right hand now, + +these two fingers, I'm going +to put a rotation onto that + +ring, and I'm going to turn +my fingers 180 degrees. + +So please watch closely. + +This is what I'm doing. + +I'm just turning my fingers +180 degrees. + +And by turning my fingers 180 +degrees, if you watch very + +closely, you can see that the +top of the ring does not touch + +the bottom of the ring. + +There is actually a little gap +in between, of course, because + +of the elasticity in the ring. + +So this is what I've tried to +do now on the computer. + +And what I'm particularly +interested to see is the + +amount of moment required in my +right hand, so to say, to + +be transmitted to the ring +in order to twist it. + +Well, here we have the results +for the computer solution. + +Notice here, we have a force +deflection, curve, rotation + +here, up to 180 degrees. + +Moment plotted here +in pounds, inch. + +And you can see that there's +fairly linear behavior first, + +but then a highly non-linear +behavior as the rotation + +becomes very large. + +Here we use the TL formulation +for the beam element. + +And once again, we rotated it +180 degrees, as I have shown + +you with my little +experiment here. + +If you look at the beam, you see +a top view like that, and + +the side view looks this way. + +I've pointed out that +top and bottom do + +not touch each other. + +There's a little air +gap in between. + +I'd like to show you now another +solution regarding the + +torsion in an analysis. + +And let me walk over to the +slides here, where I actually + +have two slides regarding +that solution. + +The interesting part of this +problem is that we now, in + +this particular analysis, are +using the same displacement + +interpolation functions for +which I've shown you already-- + +two analyses in which the +material remained elastic. + +The same interpolation functions +are now also used to + +analyze an elastoplastic +problem. + +And the problem is described +here, where we have now a + +square section subjected +to a torque. + +The material data that Greenberg +used are given here. + +And in our analysis, we used +this material data, where the + +yield stress and the +strain-hardening modulus are + +matched to this stress-strain +law here. + +Now notice what is going to +happen is, we are increasing + +this torque incrementally, and +we want to bring, of course, + +this section into the +elastoplastic regime to see + +how the section will +take the torque. + +On this slide now, we have +plotted the torque vertically + +and the rotation horizontally, +both quantities with some + +constants attached, +as you can see. + +And the Greenberg result and +the Adina result are indeed + +very close. + +Please look at the reference +that is given in the study + +guide if you're interested in +seeing and reading more about + +this problem. + +Let me now walk back to the view +graph and continue with + +the discussion of the material +relating to isoparametric + +beams and shell elements. + +The next topic that I like to +talk to you about is the + +actual use of these elements. + +Of course, the shell element +that I'm here talking about, + +or that I will share some more +experiences with you upon, is + +the shell element that I have +been already discussing in the + +earlier lecture. + +So please refer back to that +lecture with respect to this + +discussion. + +One interesting point is that +these elements can all be + +programmed for use with +different numbers of nodes. + +For the beam, we can have two, +three, or four nodes, as + +already mentioned earlier, and +for the shell, we could have + +4, 8, 9, up to 16 nodes, +as I mentioned also + +in the earlier lecture. + +The elements with these nodal +point configurations can be + +employed for analysis of +moderately thick structures. + +Remember, shear deformations +are + +approximately taken into account. + +However, if the sink of the +analysis of thin structures, + +then we have to be very careful, +and only certain + +elements of the ones that +I just referred + +to should be employed. + +For shells, we can only +recommend to use a 16-node + +element with 4-by-4 Gauss +integration over the + +mid-surface. + +This element is depicted here. + +1, 2, 3, 4, 4 times gives +us 16 nodes, and 4-by-4 + +integration indicated +by the blue crosses. + +For beams, we'd best use the +2-node beam element with + +1-point integration along the +r-direction, or the 3-node + +beam element with 2-point +integration along the + +r-direction, all or with Gauss +integration, or the 4-node + +beam element with 3-point Gauss +integration along the + +r-direction. + +We have to ask, of course, +now, why is that so? + +Well, the reason is that the +other elements become overly + +and artificially stiff when we +use them to model thin and + +curved structures. + +Two phenomena occur-- + +shear locking and membrane +locking. + +Most interesting phenomena. + +And I'd like to share with you +now some information regarding + +these phenomena. + +The 2-, 3-, and 4-node beam +elements with 1-, 2-, and + +3-point Gauss integration along +the beam axes do not + +display these phenomena, +these shear- and + +membrane-locking phenomena. + +But please notice, I'm using +1-, 2-, and 3-point Gauss + +integration corresponding +to the 2-, 3-, + +and 4-node beam element. + +The 16-node element with 4-by-4 +integration, Gauss + +integration, is also relatively +immune to shear and + +membrane locking. + +However, we have to +be careful here. + +The element should not be +distorted for best predictive + +capability. + +Let us study what this shear +locking phenomenon is. + +And to do so, let us look at a +2-noded beam, a very simple + +beam, in just 2-dimensional +action. + +So we have one node here and +one node here, and the + +defomations of the beam are +described by w1 and theta 1 at + +this node, and w2 and theta +2 at this node. + +Notice the deformations of the +beam, of course, are given by + +w, the transverse displacement, +and beta, the + +section rotation. + +The transverse displacement and +section rotation, w and + +beta, are interpolated linearly, +as shown here, via + +the nodal point displacements +and rotations. + +Notice the linear interpolation, +of course, is + +given here via this expression +and that expression, and + +similarly here via this +expression and that + +expression. + +Now there's one important point, +namely that w and beta + +are independent quantities. + +If you are familiar, as +you probably are, with + +Euler-Bernoulli beam theory, +you recognize that in + +Euler-Bernoulli beam theory, +they are not independent + +quantities. + +In fact, beta is dw dr, or dw +dx, x being the physical + +coordinate. + +Here in our formation, +isoparametric degenerate + +element, we have that beta and +w, these two quantities, once + +again, are independent and +linearly interpolated in this + +particular beam element. + +Of course, these two quantities +are tied together + +by the physics, and that is +by the shear deformation. + +So let's look at that next. + +Here we have that gamma shear +strain is equal to a del w del + +x minus beta. + +And this is shown here +on the picture. + +Notice this is a neutral axis of +the beam, which originally + +of course was horizontal. + +Here we have a vertical line +shown in green, and the + +section rotation is shown +at the angle beta here. + +These are the material particles +shown in red that + +were originally, of course, at +right angles to the neutral + +axes, and that were originally +lying vertically up. + +In other words, this line here, +this red line was a + +vertical line originally, and +was originally at right angles + +to the neutral axis. + +That right angle is not +preserved because gamma is + +there, and gamma is, in +general, a non-zero. + +This is here of course dw dx. + +So this picture here +shows what we are + +calculating up here. + +And you can see that gamma +ties together w and beta, + +which are, however, by +themselves, interpolated + +independently. + +Consider now the simple case of +a cantilever subjected to a + +tip-bending moment. + +And we use one 2-node beam +element to model the + +cantilever. + +Clearly at this end, the section +rotation is 0, and w1, + +the transverse displacement +is also 0. + +So these are the bounded +conditions at this end of the + +cantilever. + +And if we use these bounded +conditions and put them into + +our general equation, we get +directly that beta is given as + +shown here, and gamma is +given as shown here. + +Now look at this equation +carefully. + +We have a constant term and +a linear varying term. + +The exact solution to this +problem, analytical solution + +to this problem, if we use +elementary beam theory, we + +would immediately recognize that +the shear strain must be + +0 for this element, or for +this beam situation. + +The shear strain should be 0. + +Now, if we look at this +carefully, we can see that + +gamma can only be 0 if w2 +is 0, and theta 2 is 0. + +But if theta 2 and w2 are 0, +rotation and transverse + +displacement right here at this +end, then the beam would + +have not deflected. + +Of course, that is not +borne out in physics. + +We know that if we take a beam +and put a bending moment on + +it, then we get a deflection +here and a + +rotation at this end. + +So you can see already from this +equation here that there + +will be some difficulty. + +There will be some difficulty +because gamma should be 0 + +physically, and this equation +tells us that gamma can't + +really be exactly 0. + +Well, that is once more +summarized in + +this sentence here-- + +clearly, gamma cannot be 0 at +all the points along the beam + +unless theta 2 and +w2 are both 0. + +But then also beta would be 0, +and there would be no bending + +of the beam. + +Let's look now at this point. + +Since for the beam, the bending +strain energy is + +proportional to h cubed, +elementary beam theory again, + +the shear strain energy +is proportional to h-- + +elementary beam theory-- + +we see immediately that any +arrow in the shear strains due + +to the finite element +interpolation functions + +becomes increasingly +more detrimental + +is h becomes small. + +Why is that the case? + +If h becomes small, then +this number becomes + +very rapidly small. + +This number here become small, +but this one goes much faster + +to us, very small, so to say. + +And if there's an error in the +shear strain energy, that + +error, because of this +proportionality sign, is going + +to be magnified relative to any +error that we would see + +here, and it's going to be +detrimental in our solution. + +Let's look at an example. + +For the cantilever example, this +very simple example that + +we just studied already a bit, +the shear strain energy should + +be 0, and as h decreases, the +relative error in the shear + +strain increases rapidly, and +in effect introduces an + +artificial stiffness which +we identify as + +locking of the model. + +This is the terminology that +is quite widely used now. + +We say that the model locks. + +Let's look at some results. + +In this table, we show the +results for h/L with L equal + +to 100 for these three values. + +The analytical value for the +rotation at the end where the + +bending moment is applied +is given here. + +Bernoulli beam theory. + +The finite element solution, +using, of course, exact + +integration-- + +I always assume I should +maybe point that very + +strongly still out. + +We assume that we use exact +integration of the K matrix. + +Meaning in this particular +case, we're using 2-point + +Gauss integration along the +length of the beam. + +With that scheme then, we obtain +with a h/L being 0.5. + +Well, an error, but something +still reasonable. + +After all, we're only +using one element. + +Of course, we are pretty far +off, but still something + +reasonable. + +But now notice, as you decrease +h, h/L, of course, + +becomes much smaller. + +Theta analytical goes up. + +The beam basically +bends, is very + +flexible as it gets thinner. + +And the finite element solution +also becomes more + +flexible, gives us a more +flexible beam, but is much too + +stiff when compared to the +analytical solution. + +Notice for orders of magnitudes +difference. + +If you plot it, this is +basically 0 compared to that + +value, and that means +the beam locks. + +It doesn't really at all +bend anymore as h + +becomes very thin. + +This behavior is, of course, +also observed when you take + +more than 1 element +to model the beam. + +Here we show more elements than +just one, and notice that + +each of these elements +should still carry a + +constant bending moment. + +If it cannot do so, it develops, +in other words, + +these furious shear strains. + +We are going to have a very +stiff model, even when we use + +that many elements. + +Let's look at this particular +example close off. + +And here we have an example +beam, in other words, + +cantilever beam, subjected +to the bending moment. + +l equals 10 meter. + +Square cross section, +height 0.1 meter. + +We use the 2-noded beam +elements to model this + +cantilever, and we plot the tip +deflection as a function + +of the number of elements. + +A most interesting graph. + +Look, here is the beam +theory solution. + +And here we plot the number +of elements-- + +here we talk about 400 elements, +because there's + +times 10 to the 2 down here. + +400 elements at this point. + +600 elements, 800 elements, +200 elements. + +At this point we have +100 elements. + +The height of an element +is equal to the + +length of the element. + +And at this point, we still +don't even get a good + +approximation to the beam +theory solution. + +We need basically something like +400 to 500, 600 elements + +to get close to the beam +theory solution. + +However, if we take a very large +number of elements, we + +actually do converge, but we +need a lot of elements, as you + +can see here. + +Of course, it is quite +impractical to use this kind + +of 2-noded beam element to model +thin structures, then + +beams. Once again, I must point +out that we use 2-point + +Gauss integration into the +r-direction, and therefore, + +we're dealing with the exact K +matrix corresponding to the + +interpolation that we have +embedded into the element. + +In fact, if we look in this +regime down here, we find that + +as shown on this view graph, +the solution really becomes + +beta very slowly as the number +of elements is increased. + +Notice that the solution really +doesn't increase in + +accuracy much at all as we go +from 10, 20, to 30 elements. + +A remedy for the 2-node beam +element is to only use 1-point + +integration along +the beam axis. + +This then corresponds to +assuming a constant transverse + +shear strain. + +However, by using 1-point +integration, we still + +integrate the bending +strain exactly. + +Because remember, beta is +linear, del beta del x is + +constant, and 1-point +integration will pick up that + +term exactly. + +If we look at the results, now +once again, of this problem, + +cantilever problem, the +cantilever beam is subjected + +to an end moment, +tip end moment. + +We find now which h/l, as shown +here, theta analytical, + +shown here, and our finite +elements solution with just + +one element, using one element, +of course now with + +1-point integration in +r-direction, gives us + +excellent results. + +In fact, the exact results, +as you can see here. + +The 3- and 4-note beam elements, +evaluated using 2- + +and 3-point integration, +are similarly affected. + +In fact, they give us also the +exact results for this problem + +that we've considered. + +We should note now that these +theme elements, based on what + +one might reduced integration, +are actually reliable + +elements, because they do not +possess any spurious zero + +energy modes. + +They have, in other words, only +six zero energy modes + +corresponding to the actual +physical rigid body mode that + +the elements should contain, +should be able to represent, + +in its three-dimensional +space. + +So they only have those six zero +eigenvalues in this 3D + +analysis that they should have, +and no spurious zero + +energy modes. + +The formulation can actually +be interpreted as a mixed + +interpolation of displacements +and transferred shear strains. + +And this is really the key for +developing all the low-order + +effective shell elements. + +I will get back to that in +just a little while. + +So far, we have talked +about shear locking. + +I mentioned earlier also that +there is a phenomenon of + +membrane-locking. + +Membrane-locking means that in +addition to not exhibiting + +erroneous shear strains, the +beam model must also not + +contain erroneous mid-surface +membrane strains, particularly + +when we analyze curved +structures. + +The beam elements that I just +mentioned, 2-noded beam with + +1-point r-integration, 3-noded +beam with 2-point + +r-integration, 4-noded beam with +3-point r-integration, do + +also not membrane-lock. + +Let's consider here, once again, +a simple example-- + +a simple curve beam subjected +to a bending moment, + +tip-bending moment, fixed +at the other end. + +Here is an angle alpha that +the beam spans out. + +The exactly integrated 3-noded +beam element, when curved, + +does contain erroneous shear +strains and erroneous + +mid-surface membrane strains. + +In other words, shear locks +and membrane locks. + +And that is shown in +this table here, at + +least to some extent. + +What I can't show is how much +there is shear-locking and how + +much there is membrane-locking. + +You would see that both effects +are very significant. + +If you were to run, for example, +this beam element + +with a computer program, using, +for this beam element, + +3-point integration into the r +direction and printing out the + +stresses, print out all the +stress components and look at + +the shear component and the +membrane components, in other + +words, the normal stress +components, + +along the neutral axes. + +If you do so, you would see that +they are very significant + +shear stresses and very +significant membrane stresses, + +which of course should be +0 for this problem. + +And these are, of course, +causing the locking effect. + +Here we have the results in +terms of just rotations, h/R + +now, with R equal to 100, given +here, analytical value + +given here, finite element +solutions, 3-node element with + +3-point integration, you can +see we have a locking + +phenomenon right here. + +Once again, how much there is +membrane, and how much shear + +locking you would see by +actually running as a problem + +and looking at the +shear stress and + +the membrane stress. + +And the finite element +solution with 2-point + +integration gives excellent +results. + +So this is, of course, the +element that we would be using + +in engineering practice. + +Similarly, we can study +the use of the + +4-node cubic beam element. + +And here we find that for h/R, +these values, analytical value + +once more listed here, we find +that the 4-node element with + +4-point integration gives also +very good results, and the + +3-point integration gives +also excellent results. + +So we note that the cubic beam +element performs well, even + +when using full integration. + +It is not susceptible to +membrane and shear locking. + +But notice, we have our +third-point node exactly at + +the third point of +the elements. + +Once we start shifting these +nodes, then we would also not + +get as good results +as shown here. + +We would not get these good +results once you shift the + +node at the third point away +from their physical third + +point locations. + +Now, considering the analysis +of shells, the phenomenon of + +shear and membrane locking +are also present, but the + +difficulty lies in that this +simple reduced integration + +approach that we're using for +the beam elements cannot be + +directly applied, because the +resulting elements contain + +spurious zero energy modes. + +For example, if you integrate +the 4-node shell element just + +with 1-point integration, +contains 6 spurious zero + +energy modes. + +In other words, it has +altogether 12 zero eigenvalues + +where it should only have 6. + +The 6 of them are +spurious modes. + +And such spurious energy modes +can lead to very large errors + +in the solution that, unless +we have a comparison with + +accurate results, are not known, +and therefore, it can + +be very dangerous to +use such elements. + +We want to have elements that +are reliable in general + +applications, and these elements +should only contain + +the actual physical rigid +body modes, no + +spurious zero energy modes. + +And of course, should also +have high predictive + +capability, not have any shear +or membrane locking. + +For this reason, we can only +recommend the 16-node shell + +element with 4-by-4 +Gauss integration. + +The cubic beam element result +that I just showed you + +regarding the analysis of the +curve beam already indicated + +that the cubic element +does quite well. + +In fact, that is also +borne out by the + +16-node shell element. + +Using 4-by-4 Gauss integration +on the shell mid-surface, we + +have an element that is +relatively immune to membrane + +and shear locking, but I +mentioned already that the + +element should not +be distorted. + +And if it's not distorted, +it performs best. + +I'd just like to share now +with you some thoughts + +regarding development that +we have recently pursued. + +Namely, recently we have +developed elements based on + +the mixed interpolation of +tensorial components. + +This sounds very complicated. + +Actually, if you look closely at +what we're doing, it is not + +that complicated. + +The elements, however, do not +lock in shear or membrane + +action, and also do not contain +any spurious zero + +energy mode. + +And of course, that is the key +of success of an element. + +We will use later on in the +example solutions a 4-node + +element that is based on this +mixed interpolation of + +tensorial components. + +We call that element the MITC4, +Mixed Interpolation + +Tensorial Component with 4 nodes +element, and I want to + +discuss this element just +briefly with you now. + +We also have developed +an element that + +we call MITC8 element. + +It's an 8-node element based +on mixed interpolation of + +tensorial components. + +A most interesting +development. + +If you're interested in that +development, please refer to + +the paper that is given, or that +is being referred to, in + +the study guide. + +I'd like to discuss with you +now the MITC4 element, and + +then show you example +solutions. + +However, we have, in order to be +able to do that, to change + +now the reel, so let us just do +so, and then continue with + +this discussion. + +So let us look then at the MITC4 +element briefly, the + +element that I mentioned before +we had the break. + +The element is described +using four nodes. + +We have the same isoparametric +coordinate system that we are + +usually having. + +Notice here director vector, +same description as for the + +shell element that we discussed + +in the earlier lecture. + +Each node has 5 degrees of +freedom, 2 rotational degrees + +of freedom, and 3 + +translational degrees of freedom. + +Once again, the way we have +been discussing it in the + +earlier lecture. + +We use the element for analysis +of plates and for the + +analysis of moderately thick +shells, and also thin shells. + +And that is the important +point. + +This element is directly +applicable in a very effective + +manner to thin shell analysis. + +The key step in the formulation +of the element is + +to interpolate the geometry +and the displacement as + +earlier described, +as we discussed + +in the earlier lecture. + +But to interpret the transverse +shear strain tensor + +components separately, and +these interpolations are + +selected judiciously, to tie, +then, the intensities of these + +components to the values +evaluated using the + +displacement interpolations. + +Let's look at what I'm saying +here now pictorially. + +The strain tensor interpolation +that we are + +using is shown here in blue +on the black element. + +These are the rt transfer +shear strain tensor + +components. + +This is one interpolation +function, and this is the + +other interpolation function. + +Notice that if we look at the +r- and s-axes, the rt strain + +tensor component is constant +in r, but varies + +linearly with s. + +Here, too, constant in 4, +varying linearly with s. + +Now it's these intensities, one +here and one there, that + +we tie to the nodal point +displacements and rotations. + +Here for this intensity, we +use these nodal point + +descriptions, and for this +intensity, we use these nodal + +point descriptions, or nodal +point degrees of freedom. + +So if you recognize that these +are, it seems, unknown + +quantities that enter into the +formulation since we're using + +these two interpolations-- + +this one is an unknown quantity +that enters into the + +formulation, that one is an +unknown quantity that enters + +into the formulation-- + +if you recognize that, then you +have to ask yourself, what + +do we do with these unknown +quantities? + +Well, we eliminate these +unknown quantities by + +expressing them in terms of +the nodal point degrees of + +freedom, these two nodes here +and these two nodes. + +And thus we eliminate these +tensor component intensities. + +And in the K matrix and the F +vector, we end up having then + +only the nodal point + +displacement degrees of freedom. + +And that's the key part. + +For the ft transfer shear strain +tensor components, we + +use these two interpolations. + +Now we notice that we have a +linear description in r and + +constant in s for both of +these two components. + +We proceed, of course, to +eliminate this intensity and + +that intensity in terms +of the nodal + +point degrees of freedom. + +Same way as we are +proceeding here. + +This element, the MITC4 element, +has only 6 zero + +eigenvalues, no spurious +zero energy modes. + +It passes a patch test. And +this is a very important + +point-- that the element process +the patch test. What + +do we mean by the patch test? + +Well, the idea in the patch +test is that any arbitrary + +patch of elements should be +able to represent constant + +stress conditions. + +Let's see how we perform that +patch test. Here we take an + +arbitrary patch of elements. + +Some of the elements in that +patch of elements would be + +geometrically distorted. + +And we subject this patch to +the minimum displacement + +rotation boundary conditions +to eliminate the physical + +rigid body molds, and then +constant boundary tractions + +corresponding to the +constant stress + +condition that is tested. + +These two items we apply to +the patch of elements, and + +then we calculate +all nodal point + +displacement and element stresses. + +The patch test is passed if +the calculated element + +internal stresses +and nodal point + +displacements are correct. + +In other words, let's +go through this + +thought once again. + +What we're doing, +really, is we're + +looking at this structure. + +In essence, we are taking out +of this big mesh of elements + +in the structure a certain +set of elements. + +We call that set of elements +a patch of elements. + +We apply to this patch of +elements the minimum boundary + +conditions to eliminate the +rigid body molds and traction + +along the boundary that should +result in constant stress + +conditions within +the elements. + +If in fact, our solution for +that patch of elements gives + +us constant stress conditions +and nodal point displacement + +that correspond to these +constant stress conditions, + +then the patch test is passed. + +and this means that we would +have an element that + +ultimately, as the mesh is made +finer and finer with that + +element, the solution +will converge + +to the correct solution. + +That's the patch test, and +the most important test, + +particularly for shell elements, +when we have these + +complications of various kinds +of interpolations in the + +element formulation, +and so on. + +Well, here, schematically, I +show such patch of elements. + +x1-axis, x2-axes, flat +patch of elements. + +Notice the elements +not distorted, + +not rectangular elements. + +We take certain material +properties, + +assign a certain thickness. + +We make it a thin patch +of elements. + +The plate that we're looking at +here is, in essence, thin. + +Notice thickness 0.01, width +10 in both directions. + +And so if the elements would +lock do to shear or membrane + +locking, the way we discussed +earlier, we would certainly + +see it by subjecting this patch +of elements to bending + +moment boundary conditions. + +The membrane test would +correspond to these stress + +conditions. + +The bending twisting test would +correspond to these + +stress conditions. + +These are the externally applied +forces, tractions that + +the patch of element is +subjected for bending twisting + +tests, here for membrane +tests. + +And once again, we adjust the +rigid body modes from the + +patch of elements by setting +the appropriate number of + +degrees of freedom, nodal point +degrees of freedom, + +equal to zero, and then subject +that patch of elements + +to the tractions corresponding +to these stress conditions, + +the six ones that I'm +showing here. + +And we measure the internal +stresses, and find whether + +these internal stresses indeed +correspond to the constant + +stress situation. + +Also, since only those nodal +point degrees of freedom have + +been removed on the boundary +that take out the rigid body + +modes, we should also see that +the other nodal point degrees + +of freedom, of course, have +taken on the exact analytical + +value corresponding to +the constant stress + +condition that is tested. + +This one, that one, that one, +or the other three here. + +That's the patch test. + +Well, let us now to look at some +examples regarding the + +elements that we have discussed +in the previous + +lecture and this lecture. + +And the first example that I +like to look at with you is + +the analysis of a spherical +shell with a hole. + +There's a hole here, and you +see the sphere here. + +Here's the backside +of the sphere, + +shown by a dashed line. + +And this sphere is subjected to +concentrated forces, shown + +by these arrows. + +Radius given here, thickness +given here, and the material + +property of the sphere +given right there. + +The first step is to select +director vectors. + +We talked in the previous +lecture very heavily about the + +fact that we use director +vectors, and we have to define + +these director vectors. + +The initial director vectors, +or the director vectors for + +the initial configuration. + +And we in fact, in this +particular case, can quite + +easily generate the director +vectors for each node. + +The director vector for each +node, in this particular case, + +is chosen to be parallel +to the radial vector. + +So if we look, this is the skin +of the shell from the + +midpoint out via the radial +vector, we would see the + +director vector right here +in two dimensions, of + +course, x and y. + +So we generate these +director vectors. + +In ADINA, that can be +done automatically. + +And then we would select the +boundary, displacement + +boundary conditions. + +If we look at what happens, for +example, in the zx phase, + +using symmetry conditions, of +course we would only look at a + +particular part of the shell. + +The part of the shell, in fact, +maybe I should show you + +that one first, that we want +to look at is shown here. + +Notice here we have the part of +the shell that we analyze + +because of symmetry +conditions. + +We have here a symmetry +boundary and + +there a symmetry boundary. + +Notice that we have x, y, and z, +the coordinate system used + +here, and that this part of the +shell really lies in the + +part of the coordinate system +that we're looking at. + +In other words, zy, y here, +z up there, xz, x + +here, z comes out there. + +So here we have y equal to 0 on +this face, and on this face + +here, we have x equal to 0. + +And what I'd like to now talk +briefly about is about the + +selection of the boundary +conditions + +along these two faces. + +Well, these boundary conditions, +if we look at the + +zx face, in other words, this +face here, we see on this view + +graph here the x face-- +here is the shell. + +Here we would have our director +vector at time 0, and + +at time t, that director vector +would have moved as + +indicated by the red here. + +Notice that with this movement, +the only rotation + +that we can have is the +theta y rotation. + +And that is now shown on +the next view graph. + +Notice theta y here is free, +a free rotation. + +Theta x must be 0. + +Theta z must be 0. + +And of course uy must be 0, +because these are material + +particles, and in particular +that one there is a material + +particle on the zx phase. + +So uy is 0. + +uz and ux are have free. + +The free degrees of freedom, +once again, uz, + +ux, and theta y. + +Well, to impose, then, the +boundary condition, we would + +proceed as shown for this +material particle along all + +the nodes on this face, and +similarly, of course, on the + +other face-- + +the face on the zy. + +To prevent the rigid body +translations, we would also + +have to take 1 degree of freedom +out, namely one z + +degree of freedom out, one +displacement degree of freedom + +corresponding to the +z-direction out. + +And that then would basically +give us all the boundary + +conditions that we have to +apply for this problem. + +So let's look at this view graph +here to show the mesh + +that we are Using. + +And we show here that at this +node, we set uz equal to 0 to + +prevent the rigid body motion +into this direction. + +The linear elastic analysis +results for this problem are + +given here. + +Notice displacement at +the point of load + +application is 0.0936. + +The analytical value +is shown here. + +Pictorially, the original mesh +is shown in black, and the + +deformed mesh is shown in red. + +The important point of this +problem, and I'd like to go + +back to it once more, is really +that when we look at + +this mesh, that we define the +director vectors at each of + +these nodes-- + +and that can be done +automatically, they can be + +generated-- + +that at each all of these +internal nodes, we use 5 + +degrees of freedom, we have two +locally aligned alpha and + +beta degrees of freedom, the one +that I talked about in the + +earlier lecture, at each of +these internal nodes. + +I like to distinguish the +internal nodes here from the + +boundary nodes. + +On the boundary nodes, we of +course have also only 5 + +natural degrees of freedom, but +we assign now 6 degrees of + +freedom there. + +Meaning that the alpha and beta +degrees of freedom are + +rotated into the three Cartesian +coordinate axes so + +as to have three rotations at +each of these nodes on the + +symmetry faces. + +And then we can very easily +impose the symmetry boundary + +condition that I just +talked about. + +That's the important point +of this problem, really-- + +how we model the boundary +conditions, and what degrees + +of freedom are assigned +to each of the nodes. + +Well as a second example, I'd +like to consider with you the + +analysis of an open box, +a 5-sided open box. + +Here we show the box upside +down, or open site down. + +The open side, in other +words, is down here. + +And the box lies on a rigid, +frictionless surface. + +On top here, we have pressure +applied to the face. + +The box is modelled using +shell elements. + +The point of this problem is to +discuss with you how we are + +modelling this box using the +concept of director vectors, 5 + +degrees of freedom, 6 degrees of +freedom, that we discussed + +in the earlier lecture. + +So what we need to do here is +choose initial director + +vectors, choose 5 or 6 degrees +of freedom for each node, and + +choose the appropriate +boundary conditions. + +The way we proceed there +is as follows. + +We recognize that we could deal +with director vectors at + +every one of the nodes, but if +we do so, at a corner, you + +would have no unique +director vectors. + +You could, of course, assign +there a mean normal. + +In other words, if you look +closely here, my hands show + +the corner, and the pointer +shows the mean + +normal at that corner. + +And that mean normal, mean in +quotes, would be the direction + +of the director vector. + +Let me show it from +up like that. + +Here you have the right angle +between my hands, and you have + +the pointer giving you +the director vector. + +That would be one possibility. + +However, if you use ADINA, then, +in this particular case, + +it is more effective to not +input director vectors. + +Because if you don't do so +with ADINA, then for each + +node, ADINA will generate +automatically a mid-surface + +normal vector. + +In other words, if no director +vector has input for a node, + +then ADINA generates for each +element connected to the node + +a nodal point mid-surface this +normal vector at that node + +from the element geometry. + +Now, what does this mean? + +It means that if you use this +option, there will then be as + +many different nodal point +mid-surface normal vectors at + +the node as there are elements +connected to the node. + +Now we will have to look at +this statement much more + +closely for this particular +example. + +In this particular case, using +the option of automatic + +generation of element nodal +point mid-surface normal + +vectors, we find that at a node +away from an edge, we + +will end up with just one +mid-surface normal vector. + +Because see, this is a flat +surface, and the program will + +calculate for this element and +that element and that element + +and this element, corresponding +to that node, + +the same normal vector. + +And that is the normal +vector that the + +program will then use. + +However, if we look at an edge, +along an edge, and pick + +a node there, then at this node, +there will be 1 normal + +vector calculated for this +element and that element at + +that node, shown by this red +arrow, and one normal vector + +at this node calculated for this +element and that element, + +shown by this red arrow. + +Of course here, you would have +three normal vectors. + +One on that phase, that +phase, and this phase. + +Well, with these normal vectors, +then, given, you + +recognize that there will be no +stiffness corresponding to + +the rotation about this vector, +because these elements + +don't carry stiffness in this +rotational degree of freedom. + +We have to be careful with that, +and we have got to make + +sure that we solve the problem +with this rotation, the + +rotation corresponding to this +vector here or about this + +vector, being deleted +in the model. + +Whereas at this node here, we +assign 6 degrees of freedom to + +the model, because the rotation +corresponding around + +this vector will have stiffness, +around this vector + +will have stiffness, and if you +think of a rotation in the + +direction of that vector but +at this node, about this + +direction, you will have +also stiffness. + +So we need 6 degrees of freedom +being assigned at a + +node that corresponds to +an edge or corner. + +We have 5 degrees of freedom +to be assigned + +to all other nodes. + +This is once more +summarized here. + +5 degrees of freedom at all +the nodes inside a face. + +6 degrees of freedom along +an edge, and of + +course also at a corner. + +Let us look now overall at the +boundary conditions that we + +have to assign to the box +in order to be able + +to solve the problem. + +Here we show now the +box open side up. + +So this is really the side on +which the box is placed, but + +we just switch the box around +so that we can more easily + +look at what happens on +this boundary here. + +Well, we have nodes that we +might call internal nodes + +along here, nodes that +are not corner nodes. + +And these nodes would have the +following boundary condition. + +First of all, all the rotational +degrees of freedom + +shown by this arrow, +this double arrow, + +must have been deleted. + +This I just discussed. + +It is due to the fact that +there is no stiffness + +corresponding to this rotation +at that node, because all the + +elements coming into that node +don't have stiffness + +corresponding to this rotational +degree of freedom. + +This degree of freedom +is free. + +That one is free. + +This rotation is free. + +That rotation is free. + +This translation is +also deleted. + +That is due to the fact that the +box can't move vertically. + +It's placed on the +rigid surface. + +If we look at a node that is a +corner node-- and let's pick a + +more typical one. + +Here we have one. + +Then at this node, we only take +out, as you can see, the + +z displacement degree +of freedom. + +Because, once again, +the box lies on + +the rigid flat surface. + +But notice that these +rotations, all three + +rotations, are left free. + +They all carry stiffness the +way I already discussed it. + +Also these translations +are free. + +Typical corner node, another +typical corner node, the same + +action as this corner node. + +Now here we see something +in addition. + +We see that this degree of +freedom is taken out, the same + +way as over there. + +But we also see that +this degree of + +freedom is taken out. + +This one is taken out in order +to prevent a rigid body + +rotation about my +pointer here. + +That's why we take +this one out. + +And we take this one out and +that one out to also prevent + +the rigid body rotation that I +just mentioned, and to prevent + +the rigid body translation. + +See, this translation has to be +taken out as well, and that + +translation has to be taken out, +and this rotation has to + +be taken out. + +I repeat, this translation, +that translation, and that + +rotation, all of those +have to be taken out. + +And that is achieved by knocking +out this degree of + +freedom, that one, +and that one. + +So these are the boundary +conditions that we apply to + +the nodes on the edges +that are lying + +on the rigid surface. + +If we perform now a linear +elastic static analysis of the + +box with a uniform pressure +applied to the top off the + +box, using our 4-node MITC4 +element, here is a typical + +element shown, this is +[? the measure ?] + +that we use, we find that the +deformations are magnified, + +quite highly magnified, +looking like that. + +Very reasonable deformation. + +We could not compare here +with any other solution. + +But it's still a very +interesting demonstrative + +example, because of the way we +are dealing with the director + +vectors, which actually +we don't define. + +We let the program generate + +mid-surface nodal point vectors. + +And because we could discuss the +use of the shell element + +degrees of freedom, freedom is +the imposition of boundary + +conditions, and other aspects. + +This, then, brings me to the +end of what I wanted to + +discuss this you related to the +view graph, and I'd like + +to now share some further +experiences with you that I + +documented on the slides. + +So let me walk over here and let +us discuss the information + +that is even on the slides. + +The first slide here relates +to the analysis of a simply + +supported plate under +uniform pressure. + +This plate is modelled +as shown here. + +We only model 1/4 of the plate +because of symmetry + +conditions. + +And as you can see here, n is +equal to 2 for 4 elements. + +We analyze this plate and +we calculate the center + +displacement, which means the +displacement at that point, + +and compare that center +displacement to + +the analytical solution. + +Notice that in this particular +case, l/H is equal to 1000, so + +it's a very thin plate. + +And certainly we would get very +bad results if we had a + +shear locking phenomenon in the +element that we're using. + +As I pointed out earlier, the +MITC4 element does not have + +any shear locking. + +And as you can see now here, as +we increase N, as shown in + +this axes, we get excellent +convergence behavior to the + +analytical solution. + +Now the next slide shows +the analysis of a + +very similar plate. + +Again, a square plate, l/H +still being 1,000. + +Simply supported plate. + +But now the plate is subjected +to a concentrated load. + +And in this particular case, +we see the solution results + +obtained with the MITC4 element +as a function of N-- + +same number N that I referred +to in the earlier slide. + +We see that we get also very +good convergence behavior in + +this particular case. + +Not quite as good as for the +uniformly distributed pressure + +case, but still very +good as well here. + +The next slide shows the plate +now clamped at its edges. + +Not any more simply supported. + +l/H still 1,000, so still +a very thin plate. + +And here we once again +calculate the center + +displacement as a function +of N, the + +number of elements used. + +Remember, N equal 1 +means 4 elements. + +Remember N equals 4 +means 16 elements. + +Once again, we see excellent +convergence behavior to the + +exact analytical solution. + +And finally, this was a case +for uniform pressure. + +Now we look at the case for a +concentrated load applied at + +the center. + +And here we see this convergence +behavior. + +Of course, this is quite a +complicated, difficult problem + +to analyze, because of the +concentrated load and the + +clamp boundary conditions. + +Here in this analysis, we used +nice square elements. + +A very important consideration +in a practical analysis is to + +identify how well an +element performs + +when it becomes distorted. + +And the next slides now relates +to that question. + +Here we now model 1/4 of the +plate using mesh 1, shown + +here, and using mesh +2, shown here. + +Notice the elements that we're +now using in these analyses is + +still the MITC4 element. + +Each of these elements is an +MITC4 element, but it's a + +distorted element. + +And our objective is really to +identify what displacement + +predictions we obtain at the +center, at point c of the + +plate, when the plate is subject +to uniform pressure, + +and the plate is also +simply supported. + +And what displacement +predictions do we obtain for + +these two measures at +these two points? + +How much do they deteriorate +when compared to the usage of + +nice square elements? + +Well, the displacement +predictions are given here. + +Finite element over Kirchhoff +theory results. + +Mesh 1, 0.93, mesh 2, 1.01. + +Notice mesh 2 has +just 1% error. + +Mesh 1 has 7% error. + +But with mesh 1, we have a very +coarse mesh, and highly + +distorted elements. + +It's of course also of interest +to see what moment + +predictions one obtains, and +here we compare the finite + +element moment versus the +Kirchhoff moment at point c. + +And you can see 15% error for +mesh 1, 2% error for mesh 2. + +Actually also very good +results for moment + +prediction, as well. + +I should also emphasize, please, +that l/H is equal to + +1,000, so we are still talking +about this very thin plate. + +The next slide now shows how +the element behaves in the + +analysis of a skew plate. + +It's also now a distorted +element mesh, or rather, the + +elements used in the meshing +of this plate are distorted + +elements, but they're a little +bit more regular distorted. + +In fact, they are parallelogram +elements. + +Notice, please, that this is a +top view, so we are seeing a + +plan view of the plate. + +And-- + +SPEAKER: Pick up lecture +20, tape B, slide + +20-7, time code 20:33:18. + +Take one. + +PROFESSOR: The next analysis +that I like to consider now is + +the analysis of the +skew plate. + +Here we show a top view of the +skew plate with an angle of + +skew of 30 degrees. + +So it's a highly skewed plate. + +And this is the kind of +mesh we want to use. + +Here we show the 4-by-4 mesh +of MITC4 elements. + +Notice the elements are +distorted, but sort of + +regularly distorted, because +they are having a + +parallelogram shape. + +The boundary conditions on the +plate are simply supported + +boundary conditions, which I +should point out are modelled + +using the isoparametric +degenerate plate elements, + +shell elements, that +we talked about. + +These boundary conditions are +modelled by simply setting + +only the transverse displacement +at the nodes, on + +the boundary equal to 0. + +In other words, the +displacements corresponding to + +the z-axis, pointing out of the +slide, are set equal to 0, + +but the rotations on the +boundary nodes are left free. + +This is a very interesting +point, most interesting point. + +And if you like to read up on +it, please refer to the + +reference that is given +in the study guide + +related to this slide. + +Well, we use these kinds of +meshes to analyze the plate. + +Notice the material data +are given here. + +The thickness of the plate +is given here. + +B is equal to 1, so we have a +thickness with ratio of 1/100. + +It's a fairly thin plate. + +And we are considering uniform +pressure applied to the plate. + +The next slide now shows +analysis results. + +4-by-4 mesh, 8-by-8, 16-by-16, +32-by-32 meshes were used. + +We compare our finite element +solution at the point C, the + +midpoint of the plate, +versus the Morley + +solution at that point. + +And you can see that we really +have obtained very nice + +conversions to the +Morley solution. + +Notice here, we're looking +at the principal moments, + +actually the maximum and the +minimum moments, at that + +midpoint of the plate again, +point C, and we're comparing + +finite element solutions +with Morley solutions. + +And here once again, quite +good convergence for the + +moment, as well. + +Now in this analysis, we use the +kind of mesh, this 4-by-4 + +mesh, that we had on +the previous slide. + +And one can ask, of course, is +that a good mesh to use? + +Well, we deliberately wanted +to use this mesh in this + +analysis to test the capability +of the element. + +Of course, one could use +a different mesh. + +And on the next slide now, I'm +showing the results obtained + +by using just four elements, +a 2-by-2 mesh, to + +model 1/4 of the plate. + +And you can see, with this +2-by-2 mesh, we get already + +excellent predictions of the +displacement at the point C. + +This is where point +C is, once again. + +Excellent prediction of the +displacement at point C when + +compared with Morley solution. + +The moment is quite poorly +predicted, still. + +The two moments that +I defined earlier. + +If we go to a finer mesh, 4-by-4 +mesh, the moments, of + +course, are much better, and +so is the displacement + +prediction. + +But the displacement prediction +was already goods, + +so there is not that much +of an improvement. + +But in general, one can say, +this here, certainly for + +displacement predictions, is a +much better mesh to use than + +the earlier meshes that +we used for the + +earlier table results. + +Now I'd like to look at another +problem, the analysis + +of a cantilever subjected to +an end-bending moment, and + +undergoing very large +displacement. + +Here are the data given +corresponding to the + +cantilever, an elastic +structure that + +we're looking at. + +And we will be measuring v, phi, +and u, and u, v, and phi + +would take on large values. + +In fact, we will actually +normalize u and v to the + +length of the cantilever. + +The next slide now shows +the results obtained. + +v/l, u/l, and phi over +2 pi as a function + +of the moment applied. + +We're using here moment +parameter, but of course, the + +moment increases along this +axis, and here we are plotting + +u/l, v/l, and phi over 2 pi. + +Notice that even for very large +displacement, v/l being + +0.7, with 1 cubic element, cubic +in the direction of the + +cantilever, excellent results. + +This is, in other words, the use +of the cubic element, in + +general the 16-node +shell element, for + +these types of analyses. + +And it shows that the 16-node +shell element is + +really quite effective. + +The next slide now shows +how we would + +apply the MITC4 element. + +Here we use just two elements +to model the cantilever, + +bending moment applied +here, clamped + +boundary conditions here. + +And you can see that here we +are plotting u/l, w/l, phi + +over 2 pi, as before, moment +parameter along here. + +And you can see that we're +getting really excellent + +results just with 2 elements for +w/l 0.6, or certainly up + +0.5, very close to the +analytical solution. + +The analytical solution is +given by the solid line. + +The next slide now shows the +result obtained using three + +MITC4 elements to model +the same cantilever. + +Notice these are now the nodes +that we also have used when + +using the cubic element +in our first result. + +And note this excellent +comparison with the analytical + +solution for u/l, w/l, +and phi over 2 pi. + +Very large displacement under +very large displacement + +conditions. + +The next slide now shows the +analysis of an I-section + +clamped at this end +and subjected to a + +torque at this end. + +This is actually quite a +complicated problem if you + +think deeper about the problem +and recognize that you have + +torsional conditions, restrained +warping here, + +[UNINTELLIGIBLE] + +torsion here, then of course you +have bending in the beam, + +et cetera, et cetera. + +It's not a very easy +problem if you look + +deeply into the problem. + +And we wanted to obtain some +relatively good prediction for + +this structural response when +the structure goes into the + +elastoplastic regime. + +Here we have the material data +used in the analysis. + +You can see perfectly plastic +conditions by using tangent + +material modulus equal to 0. + +The slide here now shows one +model that we use, namely the + +use of altogether 9 +isoparametric cubic elements. + +These are rectangular +elements. + +Notice this is 1 isoparametric +element. + +This is the mid-surface or the +neutral axis of that one + +isoparametric cubic rectangular +section element. + +We are modeling the whole +I-beam by assembling the + +I-beam using 9 such elements. + +Of course we discussed earlier +that these elements contain + +the proper warping conditions. + +We have supplemented our +isoparametric interpolation by + +warping functions, and those +now of course will be + +activated in picking up the +torsional response, or + +modelling the torsional +response. + +This is a free end, that's +the fixed end. + +This was one model that we used, +and in addition, we used + +another model, which +is shown here-- + +a model of shell elements, +9-node shell + +elements, 9 such elements. + +Of course, a better response +would have been obtained by + +using the 16-node element, but +that of course would have been + +a more expensive analysis. + +So in this particular case, we +wanted to test this model + +versus the isoparametric beam +model that I just showed you. + +Notice one interesting point, +how we are modelling this + +connection here. + +You see a blown-up +figure of it. + +At this point node c, we have +just 5 degrees of freedom. + +No rotational stiffness about +this vector here. + +So that is not a degree +of freedom. + +Here we have 6 degrees of +freedom, 3 translational + +degrees of freedom and 3 +rotational degrees of freedom. + +Here we have 5 degrees +of freedom. + +No degree of freedom, no +stiffness corresponding to the + +rotation about this +vector here. + +That's one of the important +points that we discussed + +earlier already. + +Well, to proceed with the +analysis, we actually use the + +longitudinal element dimensions +shown here. + +Notice that we use a shorter +element at the fixed end than + +here at the free end, because we +anticipate heavy plasticity + +here that we wanted to model +quite accurately. + +Once again, the torque is +applied here, and theta x is + +measured here. + +And on the next slide now, we +show the variation of the + +torque as a function of +the theta x [? rate ?] + +rotation. + +Notice here you have the isobeam +model solution, and + +here you have the shell +model solution. + +We compare our results with +a sand heap solution and a + +Merchant's upper +bound solution. + +These are simplified analytical + +solutions to this problem. + +Our results here are somewhat +close, but not very close. + +Of course, one could make a +much deeper study of this + +problem, a very interesting +problem. + +But the way we now already have +concluded our study and + +the way I show you the results, +see, I think it's + +already quite valuable, because +we have learned a bit + +regarding the modeling of +this type of problem. + +Well, the next slide now shows +a final problem for which I + +wanted to show you some +solution results. + +Here we have a cylindrical +shell supported on rigid + +diaphragms at the end, +and the shell is + +subjected to uniform pressure. + +We measure here wB, the +displacement at that + +particular point B. The data +corresponding to the shell are + +given here. + +Notice that we model the shell +as an elastic, perfectly + +plastic material, and notice +that in the shell, we modeled + +only this part of the shell, +this quarter part of the + +shell, using a 9-by-9 +uniform mesh of the + +4-node MITC4 element. + +The results are now given +on the slide shown here. + +Pressure applied plotted along +this axis, wB plotted along + +this axis, and this is a +non-linear solution response + +we have obtained using the MITC4 +element, and we compare + +our solution with the solution +given by Krakeland. + +I might point out that in this +analysis, we used our + +automatic load-stepping scheme +that we discussed when we + +talked about the solution of the +non-linear finite element + +equations in an earlier +lecture. + +Very good comparison +up to this point + +with Krakeland's solution. + +We did not go much further +than that solution given, + +because we could not +compare with any + +other solution anyway. + +Well, this brings me now to the +end of what I wanted to + +discuss with you regarding +shell elements. + +Of course, please remember +there is a lot more + +information that we could have +discussed and that we could + +have studied together, but we +only have two lectures, and + +this is the information that I +wanted to share with you in + +these two lectures. + +I hope you enjoyed it. + +Please also refer to the papers +that are given as + +references for these two +lectures, particularly for the + +slides, where you will find much +more information, many + +more details regarding this +material that we discussed. + +Thank you very much for +your attention. \ No newline at end of file diff --git a/Fj1OICPboCU.txt b/Fj1OICPboCU.txt new file mode 100644 index 0000000000000000000000000000000000000000..77e2f709b93fa97b67d485fed8c6980cf4887eca --- /dev/null +++ b/Fj1OICPboCU.txt @@ -0,0 +1,4723 @@ +align:start position:0% + +alexa + + align:start position:0% +alexa + + + align:start position:0% +alexa +turn off the lights + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +alexa turn on the lights + + align:start position:0% +alexa turn on the lights + + + align:start position:0% +alexa turn on the lights +okay + + align:start position:0% +okay + + + align:start position:0% +okay +today on chalk radio robots and humans + + align:start position:0% +today on chalk radio robots and humans + + + align:start position:0% +today on chalk radio robots and humans +become collaborative partners + + align:start position:0% +become collaborative partners + + + align:start position:0% +become collaborative partners +it's not about let's build machines that + + align:start position:0% +it's not about let's build machines that + + + align:start position:0% +it's not about let's build machines that +look like people and act like people + + align:start position:0% +look like people and act like people + + + align:start position:0% +look like people and act like people +it's let's build machines that dovetail + + align:start position:0% +it's let's build machines that dovetail + + + align:start position:0% +it's let's build machines that dovetail +with us in a way that we can bring forth + + align:start position:0% +with us in a way that we can bring forth + + + align:start position:0% +with us in a way that we can bring forth +all of ourselves to help us achieve the + + align:start position:0% +all of ourselves to help us achieve the + + + align:start position:0% +all of ourselves to help us achieve the +goals that are really important to us + + align:start position:0% +goals that are really important to us + + + align:start position:0% +goals that are really important to us +i'm your host sarah hansen + + align:start position:0% +i'm your host sarah hansen + + + align:start position:0% +i'm your host sarah hansen +this week we're talking with a + + align:start position:0% +this week we're talking with a + + + align:start position:0% +this week we're talking with a +researcher and educator who's working to + + align:start position:0% +researcher and educator who's working to + + + align:start position:0% +researcher and educator who's working to +bridge the gap between human well-being + + align:start position:0% +bridge the gap between human well-being + + + align:start position:0% +bridge the gap between human well-being +and artificial intelligence + + align:start position:0% +and artificial intelligence + + + align:start position:0% +and artificial intelligence +from kindergarten to college classrooms + + align:start position:0% +from kindergarten to college classrooms + + + align:start position:0% +from kindergarten to college classrooms +she's preparing the next generation of + + align:start position:0% +she's preparing the next generation of + + + align:start position:0% +she's preparing the next generation of +informed technology users and empathetic + + align:start position:0% +informed technology users and empathetic + + + align:start position:0% +informed technology users and empathetic +designers + + align:start position:0% +designers + + + align:start position:0% +designers +i'm cynthia brazil i'm a professor at + + align:start position:0% +i'm cynthia brazil i'm a professor at + + + align:start position:0% +i'm cynthia brazil i'm a professor at +mit at the media lab + + align:start position:0% +mit at the media lab + + + align:start position:0% +mit at the media lab +i'm also director of a new mit wide + + align:start position:0% +i'm also director of a new mit wide + + + align:start position:0% +i'm also director of a new mit wide +initiative + + align:start position:0% +initiative + + + align:start position:0% +initiative +called responsible ai for social + + align:start position:0% +called responsible ai for social + + + align:start position:0% +called responsible ai for social +empowerment and education we call it + + align:start position:0% +empowerment and education we call it + + + align:start position:0% +empowerment and education we call it +raise for short + + align:start position:0% +raise for short + + + align:start position:0% +raise for short +and i very recently am the dean for + + align:start position:0% +and i very recently am the dean for + + + align:start position:0% +and i very recently am the dean for +digital learning + + align:start position:0% +digital learning + + + align:start position:0% +digital learning +cynthia's fascination with artificial + + align:start position:0% +cynthia's fascination with artificial + + + align:start position:0% +cynthia's fascination with artificial +intelligence began a long time ago in a + + align:start position:0% +intelligence began a long time ago in a + + + align:start position:0% +intelligence began a long time ago in a +galaxy far far away + + align:start position:0% +galaxy far far away + + + align:start position:0% +galaxy far far away +when i was 10 i saw star wars and + + align:start position:0% +when i was 10 i saw star wars and + + + align:start position:0% +when i was 10 i saw star wars and +that forever shaped my + + align:start position:0% +that forever shaped my + + + align:start position:0% +that forever shaped my +i guess vision of what a robot could be + + align:start position:0% +i guess vision of what a robot could be + + + align:start position:0% +i guess vision of what a robot could be +for us i mean it wasn't just a mindless + + align:start position:0% +for us i mean it wasn't just a mindless + + + align:start position:0% +for us i mean it wasn't just a mindless +automaton it was an entity that had you + + align:start position:0% +automaton it was an entity that had you + + + align:start position:0% +automaton it was an entity that had you +know in the movie like they were + + align:start position:0% +know in the movie like they were + + + align:start position:0% +know in the movie like they were +full-fledged characters right they had + + align:start position:0% +full-fledged characters right they had + + + align:start position:0% +full-fledged characters right they had +friendships they were mission driven to + + align:start position:0% +friendships they were mission driven to + + + align:start position:0% +friendships they were mission driven to +save the universe i mean all of that and + + align:start position:0% +save the universe i mean all of that and + + + align:start position:0% +save the universe i mean all of that and +of course they had relationships not + + align:start position:0% +of course they had relationships not + + + align:start position:0% +of course they had relationships not +just with you know the robots but with + + align:start position:0% +just with you know the robots but with + + + align:start position:0% +just with you know the robots but with +people + + align:start position:0% +people + + + align:start position:0% +people +cynthia followed that vision of complex + + align:start position:0% +cynthia followed that vision of complex + + + align:start position:0% +cynthia followed that vision of complex +human-machine relationships all the way + + align:start position:0% +human-machine relationships all the way + + + align:start position:0% +human-machine relationships all the way +to a phd program at mit + + align:start position:0% +to a phd program at mit + + + align:start position:0% +to a phd program at mit +there she designed kismet the world's + + align:start position:0% +there she designed kismet the world's + + + align:start position:0% +there she designed kismet the world's +first social robot + + align:start position:0% +first social robot + + + align:start position:0% +first social robot +that kind of started this whole question + + align:start position:0% +that kind of started this whole question + + + align:start position:0% +that kind of started this whole question +of socially and emotionally intelligent + + align:start position:0% +of socially and emotionally intelligent + + + align:start position:0% +of socially and emotionally intelligent +interaction with machines because we + + align:start position:0% +interaction with machines because we + + + align:start position:0% +interaction with machines because we +are profoundly socially and emotional + + align:start position:0% +are profoundly socially and emotional + + + align:start position:0% +are profoundly socially and emotional +creatures if we want design technologies + + align:start position:0% +creatures if we want design technologies + + + align:start position:0% +creatures if we want design technologies +that can interact with us and treat us + + align:start position:0% +that can interact with us and treat us + + + align:start position:0% +that can interact with us and treat us +again as people we need to understand + + align:start position:0% +again as people we need to understand + + + align:start position:0% +again as people we need to understand +that dimension + + align:start position:0% +that dimension + + + align:start position:0% +that dimension +you know a lot of the early work was + + align:start position:0% +you know a lot of the early work was + + + align:start position:0% +you know a lot of the early work was +pushing on i would say the algorithmic + + align:start position:0% +pushing on i would say the algorithmic + + + align:start position:0% +pushing on i would say the algorithmic +side of that we looked at a lot of + + align:start position:0% +side of that we looked at a lot of + + + align:start position:0% +side of that we looked at a lot of +models of emotion and people and animals + + align:start position:0% +models of emotion and people and animals + + + align:start position:0% +models of emotion and people and animals +and like what is the function of it and + + align:start position:0% +and like what is the function of it and + + + align:start position:0% +and like what is the function of it and +how might you implement aspects of that + + align:start position:0% +how might you implement aspects of that + + + align:start position:0% +how might you implement aspects of that +for intelligent communication and + + align:start position:0% +for intelligent communication and + + + align:start position:0% +for intelligent communication and +interaction with machines + + align:start position:0% +interaction with machines + + + align:start position:0% +interaction with machines +and then we started thinking about okay + + align:start position:0% +and then we started thinking about okay + + + align:start position:0% +and then we started thinking about okay +so what's this really good for so it's + + align:start position:0% +so what's this really good for so it's + + + align:start position:0% +so what's this really good for so it's +fascinating you know from a scientific + + align:start position:0% +fascinating you know from a scientific + + + align:start position:0% +fascinating you know from a scientific +perspective it's fascinating from a + + align:start position:0% +perspective it's fascinating from a + + + align:start position:0% +perspective it's fascinating from a +technical perspective + + align:start position:0% +technical perspective + + + align:start position:0% +technical perspective +but what does this mean about how + + align:start position:0% +but what does this mean about how + + + align:start position:0% +but what does this mean about how +we will interact with + + align:start position:0% +we will interact with + + + align:start position:0% +we will interact with +robots with intelligent machines in our + + align:start position:0% +robots with intelligent machines in our + + + align:start position:0% +robots with intelligent machines in our +lives in our future and so then we + + align:start position:0% +lives in our future and so then we + + + align:start position:0% +lives in our future and so then we +started thinking about so what are what + + align:start position:0% +started thinking about so what are what + + + align:start position:0% +started thinking about so what are what +are these big societal challenges that + + align:start position:0% +are these big societal challenges that + + + align:start position:0% +are these big societal challenges that +we face where + + align:start position:0% +we face where + + + align:start position:0% +we face where +potentially an ai cut more from this + + align:start position:0% +potentially an ai cut more from this + + + align:start position:0% +potentially an ai cut more from this +kind of cloth or this philosophy might + + align:start position:0% +kind of cloth or this philosophy might + + + align:start position:0% +kind of cloth or this philosophy might +really make a difference + + align:start position:0% +really make a difference + + + align:start position:0% +really make a difference +after kismet cynthia began working on a + + align:start position:0% +after kismet cynthia began working on a + + + align:start position:0% +after kismet cynthia began working on a +new social robot named gebo + + align:start position:0% +new social robot named gebo + + + align:start position:0% +new social robot named gebo +gebo is actually these concentric + + align:start position:0% +gebo is actually these concentric + + + align:start position:0% +gebo is actually these concentric +rotating circles that are kind of off + + align:start position:0% +rotating circles that are kind of off + + + align:start position:0% +rotating circles that are kind of off +axis + + align:start position:0% +axis + + + align:start position:0% +axis +and with that he can kind of + + align:start position:0% +and with that he can kind of + + + align:start position:0% +and with that he can kind of +create what's called an animational line + + align:start position:0% +create what's called an animational line + + + align:start position:0% +create what's called an animational line +of action so he can change his posture + + align:start position:0% +of action so he can change his posture + + + align:start position:0% +of action so he can change his posture +right so he can look like he's upright + + align:start position:0% +right so he can look like he's upright + + + align:start position:0% +right so he can look like he's upright +or he can like stoop over or lean to the + + align:start position:0% +or he can like stoop over or lean to the + + + align:start position:0% +or he can like stoop over or lean to the +side and [ __ ] his head like he can go + + align:start position:0% +side and [ __ ] his head like he can go + + + align:start position:0% +side and [ __ ] his head like he can go +through all of these kind of expressive + + align:start position:0% +through all of these kind of expressive + + + align:start position:0% +through all of these kind of expressive +postures that are + + align:start position:0% +postures that are + + + align:start position:0% +postures that are +really foundational to an animator when + + align:start position:0% +really foundational to an animator when + + + align:start position:0% +really foundational to an animator when +they want to express something through + + align:start position:0% +they want to express something through + + + align:start position:0% +they want to express something through +characters + + align:start position:0% +characters + + + align:start position:0% +characters +technologies tend to move in rectilinear + + align:start position:0% +technologies tend to move in rectilinear + + + align:start position:0% +technologies tend to move in rectilinear +trajectories + + align:start position:0% +trajectories + + + align:start position:0% +trajectories +living things move in arcs + + align:start position:0% +living things move in arcs + + + align:start position:0% +living things move in arcs +and so all of gebo's motions was based + + align:start position:0% +and so all of gebo's motions was based + + + align:start position:0% +and so all of gebo's motions was based +on arcs right so he naturally moved in a + + align:start position:0% +on arcs right so he naturally moved in a + + + align:start position:0% +on arcs right so he naturally moved in a +way that she seemed much more lifelike + + align:start position:0% +way that she seemed much more lifelike + + + align:start position:0% +way that she seemed much more lifelike +and expressive because he fundamentally + + align:start position:0% +and expressive because he fundamentally + + + align:start position:0% +and expressive because he fundamentally +was designed to move in arcs you have to + + align:start position:0% +was designed to move in arcs you have to + + + align:start position:0% +was designed to move in arcs you have to +see gebo move you have to actually watch + + align:start position:0% +see gebo move you have to actually watch + + + align:start position:0% +see gebo move you have to actually watch +him dance because like he's like it's + + align:start position:0% +him dance because like he's like it's + + + align:start position:0% +him dance because like he's like it's +incredible to watch this robot dance + + align:start position:0% +incredible to watch this robot dance + + + align:start position:0% +incredible to watch this robot dance +gebo didn't just look and move + + align:start position:0% +gebo didn't just look and move + + + align:start position:0% +gebo didn't just look and move +differently from other robots he + + align:start position:0% +differently from other robots he + + + align:start position:0% +differently from other robots he +functioned differently too + + align:start position:0% +functioned differently too + + + align:start position:0% +functioned differently too +i often use the language of there's like + + align:start position:0% +i often use the language of there's like + + + align:start position:0% +i often use the language of there's like +the + + align:start position:0% +the + + + align:start position:0% +the +digital assistant like this is what like + + align:start position:0% +digital assistant like this is what like + + + align:start position:0% +digital assistant like this is what like +google and like they're all called + + align:start position:0% +google and like they're all called + + + align:start position:0% +google and like they're all called +digital assistants and they're kind of + + align:start position:0% +digital assistants and they're kind of + + + align:start position:0% +digital assistants and they're kind of +modeled after the executive assistant + + align:start position:0% +modeled after the executive assistant + + + align:start position:0% +modeled after the executive assistant +we talk about jib as being a helpful + + align:start position:0% +we talk about jib as being a helpful + + + align:start position:0% +we talk about jib as being a helpful +companion + + align:start position:0% +companion + + + align:start position:0% +companion +so that speaks more to the social + + align:start position:0% +so that speaks more to the social + + + align:start position:0% +so that speaks more to the social +emotional the relational aspects of it + + align:start position:0% +emotional the relational aspects of it + + + align:start position:0% +emotional the relational aspects of it +but jibo is also helpful right he can + + align:start position:0% +but jibo is also helpful right he can + + + align:start position:0% +but jibo is also helpful right he can +actually do things + + align:start position:0% +actually do things + + + align:start position:0% +actually do things +but it's the way he does things are much + + align:start position:0% +but it's the way he does things are much + + + align:start position:0% +but it's the way he does things are much +more + + align:start position:0% +more + + + align:start position:0% +more +humanistic i would say human centered in + + align:start position:0% +humanistic i would say human centered in + + + align:start position:0% +humanistic i would say human centered in +its design less transactional you know + + align:start position:0% +its design less transactional you know + + + align:start position:0% +its design less transactional you know +the way he expresses himself through + + align:start position:0% +the way he expresses himself through + + + align:start position:0% +the way he expresses himself through +movement and also just the language he + + align:start position:0% +movement and also just the language he + + + align:start position:0% +movement and also just the language he +uses + + align:start position:0% +uses + + + align:start position:0% +uses +it's much more + + align:start position:0% +it's much more + + + align:start position:0% +it's much more +warm i would say like there's cool tech + + align:start position:0% +warm i would say like there's cool tech + + + align:start position:0% +warm i would say like there's cool tech +jima was warm tech + + align:start position:0% +jima was warm tech + + + align:start position:0% +jima was warm tech +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +one exciting new application for jibo + + align:start position:0% +one exciting new application for jibo + + + align:start position:0% +one exciting new application for jibo +that's currently being explored + + align:start position:0% +that's currently being explored + + + align:start position:0% +that's currently being explored +is how he might help provide mental + + align:start position:0% +is how he might help provide mental + + + align:start position:0% +is how he might help provide mental +health care + + align:start position:0% +health care + + + align:start position:0% +health care +one of the studies we did we we + + align:start position:0% +one of the studies we did we we + + + align:start position:0% +one of the studies we did we we +literally designed a emotional wellness + + align:start position:0% +literally designed a emotional wellness + + + align:start position:0% +literally designed a emotional wellness +coach skill + + align:start position:0% +coach skill + + + align:start position:0% +coach skill +for gebo and we deployed jivo in mit + + align:start position:0% +for gebo and we deployed jivo in mit + + + align:start position:0% +for gebo and we deployed jivo in mit +student dorms because as you probably + + align:start position:0% +student dorms because as you probably + + + align:start position:0% +student dorms because as you probably +know mental health is like a huge issue + + align:start position:0% +know mental health is like a huge issue + + + align:start position:0% +know mental health is like a huge issue +i mean even before the pandemic + + align:start position:0% +i mean even before the pandemic + + + align:start position:0% +i mean even before the pandemic +mental health emotional wellness of + + align:start position:0% +mental health emotional wellness of + + + align:start position:0% +mental health emotional wellness of +students at a lot of top colleges was + + align:start position:0% +students at a lot of top colleges was + + + align:start position:0% +students at a lot of top colleges was +like really concerning + + align:start position:0% +like really concerning + + + align:start position:0% +like really concerning +so we decided to explore whether gebo as + + align:start position:0% +so we decided to explore whether gebo as + + + align:start position:0% +so we decided to explore whether gebo as +an emotional wellness coach could + + align:start position:0% +an emotional wellness coach could + + + align:start position:0% +an emotional wellness coach could +actually help + + align:start position:0% +actually help + + + align:start position:0% +actually help +mitigate the stress and anxiety that + + align:start position:0% +mitigate the stress and anxiety that + + + align:start position:0% +mitigate the stress and anxiety that +students experience when they're at a + + align:start position:0% +students experience when they're at a + + + align:start position:0% +students experience when they're at a +you know an elite university like mit + + align:start position:0% +you know an elite university like mit + + + align:start position:0% +you know an elite university like mit +so we developed some best in breed + + align:start position:0% +so we developed some best in breed + + + align:start position:0% +so we developed some best in breed +therapeutic interactions that typically + + align:start position:0% +therapeutic interactions that typically + + + align:start position:0% +therapeutic interactions that typically +a human would do like a coach would do + + align:start position:0% +a human would do like a coach would do + + + align:start position:0% +a human would do like a coach would do +with their client or whatever right so + + align:start position:0% +with their client or whatever right so + + + align:start position:0% +with their client or whatever right so +typically it's human human + + align:start position:0% +typically it's human human + + + align:start position:0% +typically it's human human +we took these proven methods and we just + + align:start position:0% +we took these proven methods and we just + + + align:start position:0% +we took these proven methods and we just +now gebo was just doing it with the + + align:start position:0% +now gebo was just doing it with the + + + align:start position:0% +now gebo was just doing it with the +person and you know we published that + + align:start position:0% +person and you know we published that + + + align:start position:0% +person and you know we published that +work and basically the punchline is we + + align:start position:0% +work and basically the punchline is we + + + align:start position:0% +work and basically the punchline is we +were able to show that yeah jebos seemed + + align:start position:0% +were able to show that yeah jebos seemed + + + align:start position:0% +were able to show that yeah jebos seemed +to make a positive difference so in + + align:start position:0% +to make a positive difference so in + + + align:start position:0% +to make a positive difference so in +terms of the future of health right + + align:start position:0% +terms of the future of health right + + + align:start position:0% +terms of the future of health right +people could go into hospitals + + align:start position:0% +people could go into hospitals + + + align:start position:0% +people could go into hospitals +potentially and get you know world + + align:start position:0% +potentially and get you know world + + + align:start position:0% +potentially and get you know world +quality care but what happens when they + + align:start position:0% +quality care but what happens when they + + + align:start position:0% +quality care but what happens when they +go home + + align:start position:0% +go home + + + align:start position:0% +go home +so again something like ajibo or social + + align:start position:0% +so again something like ajibo or social + + + align:start position:0% +so again something like ajibo or social +robot or whatever the idea that they can + + align:start position:0% +robot or whatever the idea that they can + + + align:start position:0% +robot or whatever the idea that they can +extend the quality of care and support + + align:start position:0% +extend the quality of care and support + + + align:start position:0% +extend the quality of care and support +from the doctors and nurses in the + + align:start position:0% +from the doctors and nurses in the + + + align:start position:0% +from the doctors and nurses in the +hospital to the home where patients are + + align:start position:0% +hospital to the home where patients are + + + align:start position:0% +hospital to the home where patients are +living every day + + align:start position:0% +living every day + + + align:start position:0% +living every day +that's a huge unmet need + + align:start position:0% +that's a huge unmet need + + + align:start position:0% +that's a huge unmet need +and that's a role where potentially i + + align:start position:0% +and that's a role where potentially i + + + align:start position:0% +and that's a role where potentially i +think an intelligent + + align:start position:0% +think an intelligent + + + align:start position:0% +think an intelligent +kind of again collaborative allied agent + + align:start position:0% +kind of again collaborative allied agent + + + align:start position:0% +kind of again collaborative allied agent +with this different kind of interaction + + align:start position:0% +with this different kind of interaction + + + align:start position:0% +with this different kind of interaction +paradigm could make a big difference + + align:start position:0% +paradigm could make a big difference + + + align:start position:0% +paradigm could make a big difference +one of the fascinating design decisions + + align:start position:0% +one of the fascinating design decisions + + + align:start position:0% +one of the fascinating design decisions +behind jibo was choosing just how human + + align:start position:0% +behind jibo was choosing just how human + + + align:start position:0% +behind jibo was choosing just how human +to make him + + align:start position:0% +to make him + + + align:start position:0% +to make him +when we + + align:start position:0% +when we + + + align:start position:0% +when we +developed g-bow we + + align:start position:0% +developed g-bow we + + + align:start position:0% +developed g-bow we +were very intentional in saying there's + + align:start position:0% +were very intentional in saying there's + + + align:start position:0% +were very intentional in saying there's +the character of gebo + + align:start position:0% +the character of gebo + + + align:start position:0% +the character of gebo +when you talk about + + align:start position:0% +when you talk about + + + align:start position:0% +when you talk about +the perception of how + + align:start position:0% +the perception of how + + + align:start position:0% +the perception of how +children or adults perceive these agents + + align:start position:0% +children or adults perceive these agents + + + align:start position:0% +children or adults perceive these agents +jibo was what you know as the character + + align:start position:0% +jibo was what you know as the character + + + align:start position:0% +jibo was what you know as the character +was very aware that jibo was a robot and + + align:start position:0% +was very aware that jibo was a robot and + + + align:start position:0% +was very aware that jibo was a robot and +you know if you tried to ask jibo things + + align:start position:0% +you know if you tried to ask jibo things + + + align:start position:0% +you know if you tried to ask jibo things +that really a robot would have no + + align:start position:0% +that really a robot would have no + + + align:start position:0% +that really a robot would have no +business answering like things around + + align:start position:0% +business answering like things around + + + align:start position:0% +business answering like things around +religion or whatnot like jeeba would say + + align:start position:0% +religion or whatnot like jeeba would say + + + align:start position:0% +religion or whatnot like jeeba would say +this like hey i'm just a robot you know + + align:start position:0% +this like hey i'm just a robot you know + + + align:start position:0% +this like hey i'm just a robot you know +it's probably something that'd be good + + align:start position:0% +it's probably something that'd be good + + + align:start position:0% +it's probably something that'd be good +to talk about another person with but + + align:start position:0% +to talk about another person with but + + + align:start position:0% +to talk about another person with but +like + + align:start position:0% +like + + + align:start position:0% +like +i'm just a robot so jiba was very + + align:start position:0% +i'm just a robot so jiba was very + + + align:start position:0% +i'm just a robot so jiba was very +upfront and like transparent about his + + align:start position:0% +upfront and like transparent about his + + + align:start position:0% +upfront and like transparent about his +robotness + + align:start position:0% +robotness + + + align:start position:0% +robotness +collaborative allied agents like gebo + + align:start position:0% +collaborative allied agents like gebo + + + align:start position:0% +collaborative allied agents like gebo +have huge potential to improve the lives + + align:start position:0% +have huge potential to improve the lives + + + align:start position:0% +have huge potential to improve the lives +of humans + + align:start position:0% +of humans + + + align:start position:0% +of humans +but as cynthia pointed out they can't + + align:start position:0% +but as cynthia pointed out they can't + + + align:start position:0% +but as cynthia pointed out they can't +replace the power of real human social + + align:start position:0% +replace the power of real human social + + + align:start position:0% +replace the power of real human social +networks + + align:start position:0% +networks + + + align:start position:0% +networks +this gets into the ethics and the + + align:start position:0% +this gets into the ethics and the + + + align:start position:0% +this gets into the ethics and the +responsible design of these things i + + align:start position:0% +responsible design of these things i + + + align:start position:0% +responsible design of these things i +think + + align:start position:0% +think + + + align:start position:0% +think +first and foremost + + align:start position:0% +first and foremost + + + align:start position:0% +first and foremost +people need people we need + + align:start position:0% +people need people we need + + + align:start position:0% +people need people we need +our human social networks are in person + + align:start position:0% +our human social networks are in person + + + align:start position:0% +our human social networks are in person +caring human social networks to come + + align:start position:0% +caring human social networks to come + + + align:start position:0% +caring human social networks to come +around us when we're in trouble + + align:start position:0% +around us when we're in trouble + + + align:start position:0% +around us when we're in trouble +social media companies that will try to + + align:start position:0% +social media companies that will try to + + + align:start position:0% +social media companies that will try to +tell you like your network of 5000 + + align:start position:0% +tell you like your network of 5000 + + + align:start position:0% +tell you like your network of 5000 +people you don't know is just as + + align:start position:0% +people you don't know is just as + + + align:start position:0% +people you don't know is just as +important as your actual like real + + align:start position:0% +important as your actual like real + + + align:start position:0% +important as your actual like real +in-person relationships + + align:start position:0% +in-person relationships + + + align:start position:0% +in-person relationships +real in-person relationships are + + align:start position:0% +real in-person relationships are + + + align:start position:0% +real in-person relationships are +absolutely essential they're essential + + align:start position:0% +absolutely essential they're essential + + + align:start position:0% +absolutely essential they're essential +for our well-being + + align:start position:0% +for our well-being + + + align:start position:0% +for our well-being +they're essential for children's + + align:start position:0% +they're essential for children's + + + align:start position:0% +they're essential for children's +development i mean they're just critical + + align:start position:0% +development i mean they're just critical + + + align:start position:0% +development i mean they're just critical +and so + + align:start position:0% +and so + + + align:start position:0% +and so +it signals i think we're living in this + + align:start position:0% +it signals i think we're living in this + + + align:start position:0% +it signals i think we're living in this +time when + + align:start position:0% +time when + + + align:start position:0% +time when +people's time and attention has become + + align:start position:0% +people's time and attention has become + + + align:start position:0% +people's time and attention has become +like this incredibly precious resource + + align:start position:0% +like this incredibly precious resource + + + align:start position:0% +like this incredibly precious resource +where the fact that someone will stop + + align:start position:0% +where the fact that someone will stop + + + align:start position:0% +where the fact that someone will stop +and take that time out for you + + align:start position:0% +and take that time out for you + + + align:start position:0% +and take that time out for you +signals something of like you're you're + + align:start position:0% +signals something of like you're you're + + + align:start position:0% +signals something of like you're you're +valued you are really valued and you're + + align:start position:0% +valued you are really valued and you're + + + align:start position:0% +valued you are really valued and you're +you're meaningful + + align:start position:0% + + + + align:start position:0% + +as a parent the importance of real + + align:start position:0% +as a parent the importance of real + + + align:start position:0% +as a parent the importance of real +social networks for children really + + align:start position:0% +social networks for children really + + + align:start position:0% +social networks for children really +feels true to me + + align:start position:0% +feels true to me + + + align:start position:0% +feels true to me +but i also know that my child is growing + + align:start position:0% +but i also know that my child is growing + + + align:start position:0% +but i also know that my child is growing +up in a world where digital interactions + + align:start position:0% +up in a world where digital interactions + + + align:start position:0% +up in a world where digital interactions +are becoming more and more common and + + align:start position:0% +are becoming more and more common and + + + align:start position:0% +are becoming more and more common and +potentially fraught with ethical + + align:start position:0% +potentially fraught with ethical + + + align:start position:0% +potentially fraught with ethical +implications + + align:start position:0% +implications + + + align:start position:0% +implications +so i shared with cynthia a recording of + + align:start position:0% +so i shared with cynthia a recording of + + + align:start position:0% +so i shared with cynthia a recording of +my child talking with our home executive + + align:start position:0% +my child talking with our home executive + + + align:start position:0% +my child talking with our home executive +assistant + + align:start position:0% +assistant + + + align:start position:0% +assistant +alexa what's your favorite + + align:start position:0% +alexa what's your favorite + + + align:start position:0% +alexa what's your favorite +color i like ultra violet + + align:start position:0% +color i like ultra violet + + + align:start position:0% +color i like ultra violet +it glows with everything + + align:start position:0% +it glows with everything + + + align:start position:0% +it glows with everything +and here's another fun fact about me + + align:start position:0% +and here's another fun fact about me + + + align:start position:0% +and here's another fun fact about me +if you'd like i can learn your voice to + + align:start position:0% +if you'd like i can learn your voice to + + + align:start position:0% +if you'd like i can learn your voice to +do all sorts of neat things like + + align:start position:0% +do all sorts of neat things like + + + align:start position:0% +do all sorts of neat things like +greeting you by name + + align:start position:0% +greeting you by name + + + align:start position:0% +greeting you by name +you'll need your own profile i can + + align:start position:0% +you'll need your own profile i can + + + align:start position:0% +you'll need your own profile i can +create one for you now + + align:start position:0% +create one for you now + + + align:start position:0% +create one for you now +what's your name + + align:start position:0% +what's your name + + + align:start position:0% +what's your name +alexa off + + align:start position:0% +alexa off + + + align:start position:0% +alexa off +i'll create a new profile + + align:start position:0% +i'll create a new profile + + + align:start position:0% +i'll create a new profile +and send information about alexa terms + + align:start position:0% +and send information about alexa terms + + + align:start position:0% +and send information about alexa terms +and our privacy notice to your app + + align:start position:0% +and our privacy notice to your app + + + align:start position:0% +and our privacy notice to your app +should i go ahead and create a profile + + align:start position:0% +should i go ahead and create a profile + + + align:start position:0% +should i go ahead and create a profile +with the name off alexa off + + align:start position:0% + + + + align:start position:0% + +yeah so + + align:start position:0% +yeah so + + + align:start position:0% +yeah so +as illustrated by that that clip + + align:start position:0% +as illustrated by that that clip + + + align:start position:0% +as illustrated by that that clip +kids are growing up + + align:start position:0% +kids are growing up + + + align:start position:0% +kids are growing up +in a time when they will have always + + align:start position:0% +in a time when they will have always + + + align:start position:0% +in a time when they will have always +been able to talk and interact with + + align:start position:0% +been able to talk and interact with + + + align:start position:0% +been able to talk and interact with +intelligent machines and not just you + + align:start position:0% +intelligent machines and not just you + + + align:start position:0% +intelligent machines and not just you +know in this verbal way that we heard in + + align:start position:0% +know in this verbal way that we heard in + + + align:start position:0% +know in this verbal way that we heard in +the clip but + + align:start position:0% +the clip but + + + align:start position:0% +the clip but +hidden ways right so + + align:start position:0% +hidden ways right so + + + align:start position:0% +hidden ways right so +when you're on social media and it's + + align:start position:0% +when you're on social media and it's + + + align:start position:0% +when you're on social media and it's +trying to + + align:start position:0% +trying to + + + align:start position:0% +trying to +learn your kind of what your preferences + + align:start position:0% +learn your kind of what your preferences + + + align:start position:0% +learn your kind of what your preferences +are and giving you recommendations that + + align:start position:0% +are and giving you recommendations that + + + align:start position:0% +are and giving you recommendations that +are not trying to + + align:start position:0% +are not trying to + + + align:start position:0% +are not trying to +broaden your perspective but if anything + + align:start position:0% +broaden your perspective but if anything + + + align:start position:0% +broaden your perspective but if anything +narrow and narrow and narrow narrow + + align:start position:0% +narrow and narrow and narrow narrow + + + align:start position:0% +narrow and narrow and narrow narrow +or you know of course what we're + + align:start position:0% +or you know of course what we're + + + align:start position:0% +or you know of course what we're +learning is what gets your attention + + align:start position:0% +learning is what gets your attention + + + align:start position:0% +learning is what gets your attention +what tends to get shared + + align:start position:0% +what tends to get shared + + + align:start position:0% +what tends to get shared +things that really upset you + + align:start position:0% +things that really upset you + + + align:start position:0% +things that really upset you +you know those are the things that + + align:start position:0% +you know those are the things that + + + align:start position:0% +you know those are the things that +really you know so that's what it tends + + align:start position:0% +really you know so that's what it tends + + + align:start position:0% +really you know so that's what it tends +to feed you + + align:start position:0% +to feed you + + + align:start position:0% +to feed you +surprisingly quickly right you know so + + align:start position:0% +surprisingly quickly right you know so + + + align:start position:0% +surprisingly quickly right you know so +it's important for people of all ages + + align:start position:0% +it's important for people of all ages + + + align:start position:0% +it's important for people of all ages +but i think it's important for kids + + align:start position:0% +but i think it's important for kids + + + align:start position:0% +but i think it's important for kids +because like + + align:start position:0% +because like + + + align:start position:0% +because like +the average age of when kids get their + + align:start position:0% +the average age of when kids get their + + + align:start position:0% +the average age of when kids get their +first smartphone right it's like 10 + + align:start position:0% +first smartphone right it's like 10 + + + align:start position:0% +first smartphone right it's like 10 +years old right + + align:start position:0% +years old right + + + align:start position:0% +years old right +and + + align:start position:0% +and + + + align:start position:0% +and +social interaction + + align:start position:0% +social interaction + + + align:start position:0% +social interaction +through technology becomes + + align:start position:0% +through technology becomes + + + align:start position:0% +through technology becomes +such a + + align:start position:0% +such a + + + align:start position:0% +such a +key way + + align:start position:0% +key way + + + align:start position:0% +key way +they interact with each other so the + + align:start position:0% +they interact with each other so the + + + align:start position:0% +they interact with each other so 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position:0% +is there a fee associated so it's it's + + + align:start position:0% +is there a fee associated so it's it's +free again one of the great things about + + align:start position:0% +free again one of the great things about + + + align:start position:0% +free again one of the great things about +mit is we want to + + align:start position:0% +mit is we want to + + + align:start position:0% +mit is we want to +lower the barrier as much as humanly + + align:start position:0% +lower the barrier as much as humanly + + + align:start position:0% +lower the barrier as much as humanly +possible so all the materials are free + + align:start position:0% +possible so all the materials are free + + + align:start position:0% +possible so all the materials are free +you can go to + + align:start position:0% +you can go to + + + align:start position:0% +you can go to +dayofai.org + + align:start position:0% +dayofai.org + + + align:start position:0% +dayofai.org +you can + + align:start position:0% +you can + + + align:start position:0% +you can +look at the curriculum right there we + + align:start position:0% +look at the curriculum right there we + + + align:start position:0% +look at the curriculum right there we +also offer free teacher training you can + + align:start position:0% +also offer free teacher training you can + + + align:start position:0% +also offer free teacher training you can +register and you can sign up + + align:start position:0% +register and you can sign up + + + align:start position:0% +register and you can sign up +for a online training session we are + + align:start position:0% +for a online training session we are + + + align:start position:0% +for a online training session we are +collaborating with itu learning this is + + align:start position:0% +collaborating with itu learning this is + + + align:start position:0% +collaborating with itu learning this is +a company that what they do is train + + align:start position:0% +a company 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align:start position:0% +for again a broad general teacher + + + align:start position:0% +for again a broad general teacher +audience and they are running the + + align:start position:0% +audience and they are running the + + + align:start position:0% +audience and they are running the +teacher training sessions and again it's + + align:start position:0% +teacher training sessions and again it's + + + align:start position:0% +teacher training sessions and again it's +it's completely free + + align:start position:0% +it's completely free + + + align:start position:0% +it's completely free +so we would love for teachers to sign up + + align:start position:0% +so we would love for teachers to sign up + + + align:start position:0% +so we would love for teachers to sign up +we are in almost all 50 states now + + align:start position:0% +we are in almost all 50 states now + + + align:start position:0% +we are in almost all 50 states now +raise and the day of ai are increasing + + align:start position:0% +raise and the day of ai are increasing + + + align:start position:0% +raise and the day of ai are increasing +access to ai education + + align:start position:0% +access to ai education + + + align:start position:0% +access to ai education +and they're also informing how we teach + + align:start position:0% +and they're also informing how we teach + + + align:start position:0% +and they're also informing how we teach +it + + align:start position:0% +it + + + align:start position:0% +it +it is an open question still about what + + align:start position:0% +it is an open question still about what + + + align:start position:0% +it is an open question still about what +are the most effective ways of + + align:start position:0% +are the most effective ways of + + + align:start position:0% +are the most effective ways of +educating students at variety of ages + + align:start position:0% +educating students at variety of ages + + + align:start position:0% +educating students at 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align:start position:0% +ai and these computational methods in a + + + align:start position:0% +ai and these computational methods in a +way that's great and age-appropriate how + + align:start position:0% +way that's great and age-appropriate how + + + align:start position:0% +way that's great and age-appropriate how +we can prepare teachers there's a whole + + align:start position:0% +we can prepare teachers there's a whole + + + align:start position:0% +we can prepare teachers there's a whole +bunch of research questions there what + + align:start position:0% +bunch of research questions there what + + + align:start position:0% +bunch of research questions there what +are the right approaches + + align:start position:0% +are the right approaches + + + align:start position:0% +are the right approaches +methods of professional development for + + align:start position:0% +methods of professional development for + + + align:start position:0% +methods of professional development for +teachers who i mean i can tell you they + + align:start position:0% +teachers who i mean i can tell you they + + + align:start position:0% +teachers who i mean i can tell you they +didn't major in ai + + align:start position:0% +didn't major in ai + + + align:start position:0% +didn't major in ai +in college right so this is new to them + + align:start position:0% +in college right so this is new to them + + + align:start position:0% +in college right so this is new to them +too so how do we do that effectively + + align:start position:0% +too so how do we do that effectively + + + align:start position:0% +too so how do we do that effectively +what are the longer impacts of this in + + align:start position:0% +what are the longer impacts of this in + + + align:start position:0% +what are the longer impacts of this in +terms of + + align:start position:0% +terms of + + + align:start position:0% +terms of +attitudes and dispositions that students + + align:start position:0% +attitudes and dispositions that students + + + align:start position:0% +attitudes and dispositions that students +may form about these technologies and + + align:start position:0% +may form about these technologies and + + + align:start position:0% +may form about these technologies and +about kind of themselves and their + + align:start position:0% +about kind of themselves and their + + + align:start position:0% +about kind of themselves and their +relationship to these technologies + + align:start position:0% +relationship to these technologies + + + align:start position:0% +relationship to these technologies +and then as we do this you know how do + + align:start position:0% +and then as we do this you know how do + + + align:start position:0% +and then as we do this you know how do +we again holistically develop the whole + + align:start position:0% +we again holistically develop the whole + + + align:start position:0% +we again holistically develop the whole +person as well so teamwork collaboration + + align:start position:0% +person as well so teamwork collaboration + + + align:start position:0% +person as well so teamwork collaboration +communication critical thinking creative + + align:start position:0% +communication critical thinking creative + + + align:start position:0% +communication critical thinking creative +you know they all are they can all be + + align:start position:0% +you know they all are they can all be + + + align:start position:0% +you know they all are they can all be +kind of woven into this tapestry of how + + align:start position:0% +kind of woven into this tapestry of how + + + align:start position:0% +kind of woven into this tapestry of how +we try to address ai literacy + + align:start position:0% +we try to address ai literacy + + + align:start position:0% +we try to address ai literacy +through positioning students as the + + align:start position:0% +through positioning students as the + + + align:start position:0% +through positioning students as the +designers and creators and makers of the + + align:start position:0% +designers and creators and makers of the + + + align:start position:0% +designers and creators and makers of the +solutions with these technologies + + align:start position:0% +solutions with these technologies + + + align:start position:0% +solutions with these technologies +so + + align:start position:0% +so + + + align:start position:0% +so +we + + align:start position:0% +we + + + align:start position:0% +we +design these activities and then we + + align:start position:0% +design these activities and then we + + + align:start position:0% +design these activities and then we +evaluate them right so we will reach out + + align:start position:0% +evaluate them right so we will reach out + + + align:start position:0% +evaluate them right so we will reach out +and recruit + + align:start position:0% +and recruit + + + align:start position:0% +and recruit +students and teachers and we will engage + + align:start position:0% +students and teachers and we will engage + + + align:start position:0% +students and teachers and we will engage +them we often engage in co-design with + + align:start position:0% +them we often engage in co-design with + + + align:start position:0% +them we often engage in co-design with +them so even as we're developing these + + align:start position:0% +them so even as we're developing these + + + align:start position:0% +them so even as we're developing these +materials we will work with teachers and + + align:start position:0% +materials we will work with teachers and + + + align:start position:0% +materials we will work with teachers and +students as we develop them to make sure + + align:start position:0% +students as we develop them to make sure + + + align:start position:0% +students as we develop them to make sure +that + + align:start position:0% +that + + + align:start position:0% +that +they're you know effective in responding + + align:start position:0% +they're you know effective in responding + + + align:start position:0% +they're you know effective in responding +and engaging + + align:start position:0% +and engaging + + + align:start position:0% +and engaging +and then we go do rigorous + + align:start position:0% +and then we go do rigorous + + + align:start position:0% +and then we go do rigorous +of + + align:start position:0% +of + + + align:start position:0% +of +what are they understanding or not + + align:start position:0% +what are they understanding or not + + + align:start position:0% +what are they understanding or not +understanding what is their pathway to + + align:start position:0% +understanding what is their pathway to + + + align:start position:0% +understanding what is their pathway to +understanding and what is the + + align:start position:0% +understanding and what is the + + + align:start position:0% +understanding and what is the +implication of that for how we think + + align:start position:0% +implication of that for how we think + + + align:start position:0% +implication of that for how we think +about staging these concepts and ideas + + align:start position:0% +about staging these concepts and ideas + + + align:start position:0% +about staging these concepts and ideas +are we seeing evidence that they are + + align:start position:0% +are we seeing evidence that they are + + + align:start position:0% +are we seeing evidence that they are +developing dispositions about ai that + + align:start position:0% +developing dispositions about ai that + + + align:start position:0% +developing dispositions about ai that +are empowering for them or do they find + + align:start position:0% +are empowering for them or do they find + + + align:start position:0% +are empowering for them or do they find +it as being intimidating or not for them + + align:start position:0% +it as being intimidating or not for them + + + align:start position:0% +it as being intimidating or not for them +right so there's a lot of questions that + + align:start position:0% +right so there's a lot of questions that + + + align:start position:0% +right so there's a lot of questions that +we're trying to assess + + align:start position:0% +we're trying to assess + + + align:start position:0% +we're trying to assess +and then when we have something we think + + align:start position:0% +and then when we have something we think + + + align:start position:0% +and then when we have something we think +is solid you know then we + + align:start position:0% +is solid you know then we + + + align:start position:0% +is solid you know then we +we make it available for free it's all + + align:start position:0% +we make it available for free it's all + + + align:start position:0% +we make it available for free it's all +creative commons we're like our goal is + + align:start position:0% +creative commons we're like our goal is + + + align:start position:0% +creative commons we're like our goal is +just + + align:start position:0% +just + + + align:start position:0% +just +to help empower teachers + + align:start position:0% +to help empower teachers + + + align:start position:0% +to help empower teachers +non-profits you know like get these + + align:start position:0% +non-profits you know like get these + + + align:start position:0% +non-profits you know like get these +materials out there and share them + + align:start position:0% +materials out there and share them + + + align:start position:0% +materials out there and share them +freely + + align:start position:0% +freely + + + align:start position:0% +freely +but again no matter how good robots or + + align:start position:0% +but again no matter how good robots or + + + align:start position:0% +but again no matter how good robots or +ai get + + align:start position:0% +ai get + + + align:start position:0% +ai get +they're no replacement for the real + + align:start position:0% +they're no replacement for the real + + + align:start position:0% +they're no replacement for the real +thing + + align:start position:0% +thing + + + align:start position:0% +thing +i think a lot of ai has assumed when + + align:start position:0% +i think a lot of ai has assumed when + + + align:start position:0% +i think a lot of ai has assumed when +you're trying to build these social and + + align:start position:0% +you're trying to build these social and + + + align:start position:0% +you're trying to build these social and +emotional qualities into technology it's + + align:start position:0% +emotional qualities into technology it's + + + align:start position:0% +emotional qualities into technology it's +about the robot + + align:start position:0% +about the robot + + + align:start position:0% +about the robot +and i'm like no it's about the people + + align:start position:0% +and i'm like no it's about the people + + + align:start position:0% +and i'm like no it's about the people +because this is what people need to + + align:start position:0% +because this is what people need to + + + align:start position:0% +because this is what people need to +engage the more deeply we can engage + + align:start position:0% +engage the more deeply we can engage + + + align:start position:0% +engage the more deeply we can engage +of our holistic self not just our + + align:start position:0% +of our holistic self not just our + + + align:start position:0% +of our holistic self not just our +cognitive selves but our social selves + + align:start position:0% +cognitive selves but our social selves + + + align:start position:0% +cognitive selves but our social selves +our emotional selves our physical self + + align:start position:0% +our emotional selves our physical self + + + align:start position:0% +our emotional selves our physical self +so more deeply we can engage not + + align:start position:0% +so more deeply we can engage not + + + align:start position:0% +so more deeply we can engage not +surprisingly the more successful we are + + align:start position:0% +surprisingly the more successful we are + + + align:start position:0% +surprisingly the more successful we are +the better our outcome so it's to say + + align:start position:0% +the better our outcome so it's to say + + + align:start position:0% +the better our outcome so it's to say +it's not about let's build machines that + + align:start position:0% +it's not about let's build machines that + + + align:start position:0% +it's not about let's build machines that +look like people and act like people + + align:start position:0% +look like people and act like people + + + align:start position:0% +look like people and act like people +it's let's build machines that dovetail + + align:start position:0% +it's let's build machines that dovetail + + + align:start position:0% +it's let's build machines that dovetail +with us in a way that we can bring forth + + align:start position:0% +with us in a way that we can bring forth + + + align:start position:0% +with us in a way that we can bring forth +all of ourselves to help us achieve the + + align:start position:0% +all of ourselves to help us achieve the + + + align:start position:0% +all of ourselves to help us achieve the +goals that are really important to us + + align:start position:0% +goals that are really important to us + + + align:start position:0% +goals that are really important to us +this is why i like when we talk about + + align:start position:0% +this is why i like when we talk about + + + align:start position:0% +this is why i like when we talk about +ai as pedagogical agents right i'm like + + align:start position:0% +ai as pedagogical agents right i'm like + + + align:start position:0% +ai as pedagogical agents right i'm like +we will never get rid of human teachers + + align:start position:0% +we will never get rid of human teachers + + + align:start position:0% +we will never get rid of human teachers +because + + align:start position:0% +because + + + align:start position:0% +because +they are essential for children to know + + align:start position:0% +they are essential for children to know + + + align:start position:0% +they are essential for children to know +that in this community of human beings + + align:start position:0% +that in this community of human beings + + + align:start position:0% +that in this community of human beings +adults + + align:start position:0% +adults + + + align:start position:0% +adults +invest their time + + align:start position:0% +invest their time + + + align:start position:0% +invest their time +in children's learning and development + + align:start position:0% +in children's learning and development + + + align:start position:0% +in children's learning and development +like you matter i'm taking time and + + align:start position:0% +like you matter i'm taking time and + + + align:start position:0% +like you matter i'm taking time and +energy to do this because it's that + + align:start position:0% +energy to do this because it's that + + + align:start position:0% +energy to do this because it's that +important and you are that important + + align:start position:0% +important and you are that important + + + align:start position:0% +important and you are that important +yeah you just can't underestimate that + + align:start position:0% +yeah you just can't underestimate that + + + align:start position:0% +yeah you just can't underestimate that +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +to take part in the day of ai on may + + align:start position:0% +to take part in the day of ai on may + + + align:start position:0% +to take part in the day of ai on may +13th go to + + align:start position:0% +13th go to + + + align:start position:0% +13th go to +dayofai.org + + align:start position:0% +dayofai.org + + + align:start position:0% +dayofai.org +you can access free teacher training and + + align:start position:0% +you can access free teacher training and + + + align:start position:0% +you can access free teacher training and +other creative commons educational + + align:start position:0% +other creative commons educational + + + align:start position:0% +other creative commons educational +materials at raise.mit.edu + + align:start position:0% +materials at raise.mit.edu + + + align:start position:0% +materials at raise.mit.edu +or you can access them through our + + align:start position:0% +or you can access them through our + + + align:start position:0% +or you can access them through our +website at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +you can also find cynthia's free and + + align:start position:0% +you can also find cynthia's free and + + + align:start position:0% +you can also find cynthia's free and +open teaching materials from our mit + + align:start position:0% +open teaching materials from our mit + + + align:start position:0% +open teaching materials from our mit +courses on our website + + align:start position:0% +courses on our website + + + align:start position:0% +courses on our website +thank you so much for listening + + align:start position:0% +thank you so much for listening + + + align:start position:0% +thank you so much for listening +until next time signing off from a + + align:start position:0% +until next time signing off from a + + + align:start position:0% +until next time signing off from a +galaxy not too far away i'm sarah hansen + + align:start position:0% +galaxy not too far away i'm sarah hansen + + + align:start position:0% +galaxy not too far away i'm sarah hansen +from mit opencourseware + + align:start position:0% +from mit opencourseware + + + align:start position:0% +from mit opencourseware +chalk radio's producers include myself + + align:start position:0% +chalk radio's producers include myself + + + align:start position:0% +chalk radio's producers include myself +red pachy and dave lashansky + + align:start position:0% +red pachy and dave lashansky + + + align:start position:0% +red pachy and dave lashansky +scriptwriting assistance from aubry + + align:start position:0% +scriptwriting assistance from aubry + + + align:start position:0% +scriptwriting assistance from aubry +callaway + + align:start position:0% +callaway + + + align:start position:0% +callaway +show notes for this episode were written + + align:start position:0% +show notes for this episode were written + + + align:start position:0% +show notes for this episode were written +by peter chipman + + align:start position:0% +by peter chipman + + + align:start position:0% +by peter chipman +the rey's online publication was shared + + align:start position:0% +the rey's online publication was shared + + + align:start position:0% +the rey's online publication was shared +on mit open courseware by sharon lin + + align:start position:0% +on mit open courseware by sharon lin + + + align:start position:0% +on mit open courseware by sharon lin +we're funded by mit open learning and + + align:start position:0% +we're funded by mit open learning and + + + align:start position:0% +we're funded by mit open learning and +supporters like you \ No newline at end of file diff --git a/GCFd0VVnWTw.txt b/GCFd0VVnWTw.txt new file mode 100644 index 0000000000000000000000000000000000000000..b569aeb36d37cf1f4ccf5a4588af8ea9d2ea97cc --- /dev/null +++ b/GCFd0VVnWTw.txt @@ -0,0 +1,3550 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high-quality educational +resources for free. + +To make a donation or view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +PROFESSOR: OK, let's get started +again on finite-state + +Markov chains. + +Sorry I was away last week. + +It was a long-term commitment +that I had to honor. + +But I think I will +be around for all + +the rest of the lectures. + +So I want to start out by +reviewing just a little bit. + +I'm spending a lot more time on +finite-state Markov chains + +than we usually do in this +course, partly because I've + +rewritten this section, partly +because I think the material + +is very important. + +It's sort of bread-and-butter +stuff, of + +discrete stochastic processes. + +You use it all the time. + +It's a foundation for almost +everything else. + +And after thinking about it +for a long time, it really + +isn't all that complicated. + +I used to think that all these +details of finding eigenvalues + +and eigenvectors and so on +was extremely tedious. + +And it turns out that +there's a very nice + +pleasant theory there. + +You can find all of these things +after you know what + +you're doing by very simple +computer packages. + +But they don't help if you don't +know what's going on. + +So here, we're trying to figure +out what's going on. + +So let's start out by reviewing +what we know about + +ergodic unit chains and +proceed from there. + +An ergodic finite-state Markov +chain has transition + +probabilities which, if you look +at the transition matrix + +raised to the nth power, what +that gives you is the + +transition probabilities of +an n-step Markov chain. + +In other words, you start at +time 0, and at time n, you + +look at what state you're in. + +P sub ij to the nth power is +then the probability that + +you're in state j at time +n, given that you're in + +state i at time 0. + +So this has all the information +that you want + +about what happens to Markov +chain as time gets large. + +One of the things we're most +concerned with is, do you go + +to steady state? + +And if you do go to steady +state, how fast do you go to + +steady state? + +And of course, this matrix +tells you the whole story + +there, because if you go to +steady state, and the Markov + +chain forgets where it started, +then P sub ij to the + +n goes to some constant, pi sub +j, which is independent of + +the starting state, i, +and independent of m, + +asymptotically, as n gets big. + +So this pi is a strictly +positive probability vector. + +I shouldn't say so it is. + +That's something that +was shown last time. + +If you multiply both sides of +this equation by P sub jk in + +sum over k, then what +do you get? + +You get P sub ik to +the n plus 1. + +That goes to a limit also. + +If the limit in n +goes to infin-- + +then the limit as n plus 1 goes +to infinity is clearly + +the same thing. + +So this quantity here is +the sum over j, of pi + +sub j, P sub jk. + +And this quantity is equal to +pi sub k, just by definition + +of this quantity. + +So P sub k is equal +to sum of pi j. + +Pjk, what does that say? + +That's the definition of +a steady state vector. + +That's the definition of, if +your probabilities of being in + +state k satisfy this equation, +then one step later, you still + +have the same probability +of being in state k. + +Two steps later, you still have +the same probability of + +being in state k. + +So this is called the steady +state equation. + +And a solution to that is called +a steady state vector. + +And that satisfies this. + +In matrix terms, if you rate +this out, what does it say? + +It says the limit as n +approaches infinity of p to + +the n is equal to the column +vector, e of all 1s. + +The transpose here means +it's a column vector. + +So you have a column vector +times a row vector. + +Now, you know if you have a +row vector times a column + +vector, that just gives +you a number. + +If you have a column +vector times a row + +vector, what happens? + +Well, for each element +of the column, you + +get this whole row. + +And for the next element of the +column, you get the whole + +row down beneath it multiplied +by the element of the column, + +and so forth, day on. + +So a column vector times +a row vector is, in + +fact, a whole matrix. + +It's a j by j matrix. + +And since e is all 1s, what +that matrix is is a matrix + +where every row is a steady +state vector pi. + +So we're saying not only does +this pi that we're talking + +about satisfy this steady +state equation, but more + +important, it's this limiting +vector here. + +And as n goes to infinity, +you in fact do + +forget where you were. + +And the entire matrix of where +you are at time n, given where + +you were at time 0, goes to +just this fixed vector pi. + +So this is a column vector, and +pi is a row vector then. + +The same result almost holds +for ergodic unit chains. + +What's an ergodic unit chain? + +An ergodic unit chain is an +ergodic set of states plus a + +whole bunch of transient +states. + +Doesn't matter whether the +transient states are one class + +of transient states or whether +it's multiple classes of + +transient states. + +It's just transient states. + +And there's one recurrent +class. + +And we're assuming here +that it's recurrent. + +So you can almost see +intuitively that if you start + +out in any one of these +transient states, you bum + +around through the transient +states for a while. + +And eventually, you flop off +into the recurrent class. + +And once you're in +the recurrent + +class, there's no return. + +So you stay there forever. + +Now, that's something that +has to be proven. + +And it's proven in the notes. + +It was probably proven +last time. + +But anyway, what happens then +is that the sole difference + +between ergodic unit chains and +just having a completely + +ergodic Markov chain is that the +steady state factor is now + +positive for all ergodic states +and it's 0 for all + +transient states. + +And aside from that, you still +get the same behavior still. + +As n gets large, you go to the +steady state vector, which is + +the steady state vector +of the ergodic chain. + +If you're doing this stuff by +hand, how do you do it? + +Well, you start out just +with the ergodic class. + +I mean, you might as well +ignore everything else, + +because you know that eventually +you're in that + +ergodic class. + +And you find the steady state +vector in that ergodic class, + +and that's the steady +state vector you're + +going to wind up with. + +This is one advantage of +understanding what you're + +doing, because if you don't +understand what you're doing + +and you're just using computer +programs, then you never have + +any idea what's ergodic, +what's not + +ergodic or anything else. + +You just plug it, you grind +away, you get some answer and + +say, ah, I'll publish a paper. + +And you put down exactly what +the computer says, but you + +have no interpretation +of it at all. + +So the other way of looking at +this is, when you have a bunch + +of transient states, and you +also have an ergodic class, + +you can represent a matrix if +the recurrent states are at + +the end of the chain and the +transient states are at the + +beginning of the chain. + +This matrix here is the matrix +of transition probabilities + +within the recurrent class. + +These are the probabilities for +going from the transient + +states to the recurrent class. + +And once you get over +here, the only place + +to go is down here. + +And the transient class is +just a t by t class. + +And the recurrent class +is just a j minus t + +by j minus t matrix. + +So the idea is that each +transient state eventually has + +a transition to a recurrent +state, and the class of + +recurrent states leads to +study state as before. + +So that really, all that +analysis of ergodic unit + +chains, if you look at it +intuitively, it's all obvious. + +Now, as in much of mathematics, +knowing that + +something is obvious does not +relieve you of the need to + +prove it, because sometimes you +find that something that + +looks obvious is true +most of the time but + +not all of the time. + +And that's the purpose of +doing these things. + +There's another way to express +this eigenvalue, eigenvector + +equation we have here. + +And that is that the transition +matrix minus lambda + +times the identity matrix times +the column vector v is + +equal to 0. + +That's the same as the equation +p times v is equal to + +v. That's the same as +a right eigenvector. + +Well, this is the equation +for an eigenvalue 1. + +This is an equation for an +arbitrary eigenvalue lambda. + +But p times v equals lambda +times v is the same as p minus + +lambda i times v equals 0. + +Why do we even bother to say +something so obvious? + +Well, because when you look at +linear algebra, how many of + +you have never studied any +linear algebra at all or have + +only studied completely +mathematical linear algebra, + +where you never deal with +n-tuples as vectors or + +matrices or any things +like this? + +Is there anyone? + +If you don't have this +background, pick up-- + +what's his name? + +AUDIENCE: Strang. + +PROFESSOR: Strang. + +Strang's book. + +It's a remarkably simple-minded +book which says + +everything as clearly +as it can be stated. + +And it tells you everything +you have to know. + +And it does it in a very +straightforward way. + +So I highly recommend it to get +any of the background that + +you might need. + +Most of you, I'm sure, are very + +familiar with these things. + +So I'm just reminding +you of then. + +Now, a square matrix is singular +if there's a vector + +v, such that a times +v is equal to 0. + +That's just a definition +as a singularity. + +Now, lambda is an eigenvalue of +a matrix p if and only if p + +minus lambda times +i is singular. + +In other words, if there's +some v for which p minus + +lambda i times v is equal to +0, that's what this says. + +You put p minus lambda i in +for a, and it says it's + +singular if there's some v +for which this matrix-- + +this matrix is singular if +there's some v such that p + +minus lambda i times +v is equal to 0. + +So let a1 to am be +the columns of a. + +Then a is going to be +singular if a1 to am + +are linearly dependent. + +In other words, if there's some +set of coefficients you + +can attach to a1 times v1 plus +a2 times v2, plus up to am + +times vm such that that sum is +equal to 0, that means that a1 + +to am are linearly dependent. + +It also means that the matrix a +times that v is equal to 0. + +So those two things say +the same thing again. + +So the square matrix, a, is +singular if and only if the + +rows of a are linearly +independent. + +We set columns here. + +Here, we're doing the +same thing for rows. + +It still holds true. + +And one new thing, if and only +if the determinant of a is + +equal to 0. + +One of the nice things about +determinants is that + +determinants are 0 if the matrix +is singular, if and + +only if the matrix +is singular. + +So the summary of all of this +for a matrix which is a + +transition matrix-- + +namely, a stochastic matrix-- + +is lambda, is an eigenvalue of +p, if and only if p minus + +lambda i is singular, if and +only if the determinant of p + +minus lambda i is equal to 0, +if and only if p times some + +vector v equals lambda v, and +if and only if u times p + +equals lambda u for some u. + +Yes? + +AUDIENCE: The second to last +statement is actually linearly + +independent, you said? + +The second to last. + +Square matrix a. + +No, above that. + +PROFESSOR: Oh, above that. + +A square matrix a is singular +if and only if the rows of a + +are linearly dependent, yes. + +AUDIENCE: Dependent. + +PROFESSOR: Dependent, yes. + +In other words, if there's +some vector v such that a + +times v is equal to 0, that +means that those columns are + +linearly dependent. + +So we need all of those +relationships. + +It says for every stochastic +matrix-- + +oh, now this is something new. + +For every stochastic matrix, +P times e is equal to e. + +Obviously, because if you sum +up the sum of Pij over j is + +equal to 1. + +P sub ij is the probability, +given that you start in state + +i, that in the next step, +you'll be in state j. + +You have to be somewhere +in the next step. + +So if you sum these quantities +up, you have to get 1, which + +says you have to +be some place. + +So that's all this is saying. + +That's true for every +finite-state Markov chain in + +the world, no matter how ugly +it is, how many sets of + +recurrent states it has, how +much periodicity it has. + +A complete generality, P +times e is equal to e. + +So lambda is always an +eigenvalue of a stochastic + +matrix, and e is always +a right eigenvector. + +Well, from what we've just said, +that means there has to + +be a left eigenvector also. + +So there has to be some +pi such that pi times + +P is equal to pi. + +So suddenly, we find there's +also a left eigenvector. + +What we haven't shown yet is +that that pi that satisfies + +this equation is a probability +vector. + +Namely, we haven't shown that +all the components of pi are + +greater than or equal to 0. + +We still have to do that. + +And in fact, that's not +completely trivial. + +If we can find such a vector +that is a probability vector, + +the compound in sum to 1 and +they're not negative, then + +this is the equation for +a steady state vector. + +So what we don't know yet +is whether a steady + +state vector exists. + +We do know that a left +eigenvector exists. + +We're going to show later +that there is a steady + +state vector pi. + +In other words, a non-negative +vector which sums to 1 for all + +finite-state Markov chains. + +In other words, no matter how +messy it is, just like e, the + +column vector of all 1s is +always a right eigenvector of + +eigenvalue 1. + +There is always a non-negative +vector pi whose components sum + +to 1, which is a left +eigenvector with eigenvalue 1. + +So these two relationships +hold everywhere. + +Incidentally, the notes +at one point claim + +to have shown this. + +And the notes really +don't show it. + +I'm going to show +it to you today. + +I'm sorry for that. + +It's something I've known for so +long that I find it hard to + +say is this true or not. + +Of course it's true. + +But it does have to be shown, +and I will show it + +to you later on. + +Chapter three of the notes is +largely rewritten this year. + +And it has a few more typos +in it than most + +of the other chapters. + +And a few of the typos +are fairly important. + +I'll try to point some +of them out as we go. + +But I'm sure I haven't +caught them all yet. + +Now, what is the determinant +of an M by M matrix? + +It's this very simple-looking +but rather messy formula, + +which says the determinant of +a square matrix A is the sum + +over all partitions-- + +and then there's a plus +minus here, which + +I'll talk about later-- + +of the product from i equals +1 to M. M is the number of + +states of A sub i. + +This is the component +of the ij position. + +And we're taking A sub i. + +And then the partition that +we're dealing with, mu sub i. + +So what we're doing is taking +a matrix with all sorts of + +terms in it-- + +A11 up to A1j on to Aj1 +up to A sub jj. + +And these partitions we're +talking about are ways of + +selecting one element from each +row and one element from + +each column. + +Namely, that first sum there is +talking about one element + +from each row. + +And then when we're talking +about a permutation here, + +we're doing something like, for +this row, we're looking + +at, say, this element. + +For this row, we might be +looking at this element. + +For this row, we might be +looking at this element, and + +so forth down, until finally, +we're looking at some + +element down here. + +Now, we've picked out every +column and every row in doing + +this, but we only have one +element in each row and one + +element in each column. + +If you've studied linear algebra +and you're at all + +interested in computation, the +first thing that everybody + +tells you is that this is a +god-awful way to ever compute + +a determinant, because the +number of permutations grows + +very, very fast with the +size of the matrix. + +And therefore you don't +want to use this + +formula very often. + +It's a very useful formula +conceptually, though, because + +if we look at the determinant +of p minus lambda i, if we + +want to ask the question, how +many eigenvalues does this + +transition matrix have? + +well, the number of eigenvalues +it has is the + +number of values of lambda such +that the determinant of p + +minus lambda i is 0. + +Now, how many such +values are there? + +Well, you look the matrix for +that, and you get A11 minus + +lambda A12 and A22 minus lambda +Ajj minus lambda. + +And none of the other elements +have lambda in it. + +So when you're looking at this +formula for finding the + +determinant, one of the +partitions is this partition, + +which is a polynomial of +degree j in lambda. + +All of the others are +polynomials of degree less + +than j in lambda. + +And therefore this whole +bloody mess here is a + +polynomial of degree +j and lambda. + +So the equation, determinant of +p minus lambda i, which is + +a polynomial of degree j +in lambda, equals 0. + +How many roots does it have? + +Well, the fundamental theorem +of algebra says that a + +polynomial of degree j, +of complex numbers-- + +and real is a special +case of complex-- + +that it has exactly j roots. + +So there are exactly, +in this case, M-- + +excuse me, I've been +calling it j + +sometimes and M sometimes. + +This equation here has exactly +M roots to it. + +And since it has exactly M +roots, that's the number of + +eigenvalues there are. + +There's one flaw in +that argument. + +And that is, some of the roots +might be repeated. + +Say you have M roots +altogether. + +Some of them appear more than +one time, so you'll have roots + +of multiplicity, something +or other. + +And when you add up the +multiplicities of each of the + +distinct eigenvalues, you +get capital M, which is + +the number of states. + +So the number of different +eigenvalues is less than or + +equal to M. And the number of +distinct eigenvalues times the + +multiplicity of each eigenvalue +is equal to M. + +That's a simple, straightforward +fact. + +And it's worth remembering. + +So there are M roots +to the equation. + +Determinant p minus +lambda i equals 0. + +And therefore there are +M eigenvalues of p. + +And therefore you might think +that there are M eigenvectors. + +That, unfortunately, is +not true necessarily. + +That's one of the really-- + +it's probably the only really +ugly thing in linear algebra. + +I mean, linear algebra is +a beautiful theory. + +I mean, it's like Poisson's +stochastic processes. + +Everything that can +be true is true. + +And if something isn't true, +there's a simple + +counter-example of why +it can't be true. + +This thing is just +a bloody mess. + +But unfortunately, if you have +M states in a finite-state + +Markov chain, you might not have +M different eigenvectors. + +And that's unfortunate, but we +will forget about that for as + +long as we can, and we'll +finally come back to it + +towards the end. + +AUDIENCE: [INAUDIBLE]? + +PROFESSOR: What? + +AUDIENCE: Why would we care +about all the eigenvectors if + +we are only concerned with the +ones that [INAUDIBLE]? + +PROFESSOR: Well, because we're +interested in the other ones + +because that tells us how fast +p to the M converges to what + +it should be. + +I mean, all those other +eigenvalues, as we'll see, are + +the error terms in p to the +M as it approaches this + +asymptotic value. + +And therefore we want to know +what those eigenvalues are. + +At least we want to +know what the + +second-biggest eigenvalue is. + +Now, let's look at just +a case of two states. + +Most of the things that can +happen will happen with two + +states, except for this ugly +thing that I told you about + +that can't happen +with two states. + +And therefore two states is a +good thing to look at, because + +with two states, you can +calculate everything very + +easily and you don't have to +use any linear algebra. + +So if we look at a Markov chain +with two states, P sub + +ij is this set of transition +probabilities. + +The left eigenvector equation +is pi 1 times P11 times pi 2 + +times P21 is equal +to lambda pi 1. + +And so this is writing out +what we said before. + +The vector pi times the matrix +P is equal to lambda + +times the vector pi. + +That covers both of +these equations. + +Since M is only 2, +we only have to + +write things out twice. + +Same thing for the right +eigenvector equation. + +That's this. + +The determinant of P minus +lambda i, if we use this + +formula that we talked about +here, you put A11 minus + +lambda, A22 minus lambda. + +Well, then you're done. + +So all you need is P11 minus +lambda times P22 minus lambda. + +That's this permutation there. + +And then you have an odd +permutation, A12 times A21. + +How do you know which +permutations are even and + +which permutations are odd? + +It's how many flips +you have to do. + +But to see that that's +consistent, you really have to + +look at Strang or some book on +linear algebra, because it's + +not relevant here. + +But anyway, that determinant +is equal to + +this quantity here. + +That's a polynomial of +degree 2 in lambda. + +If you solve it, you find +out that one solution is + +lambda 1 equals 1. + +The other solution is lambda +2 is 1 minus P12 minus P21. + +Now, there are a bunch of +cases to look at here. + +If the off-diagonal transition +probabilities are both 0, what + +does that mean? + +It means if you start in state +0, you stay there. + +If you start in state 1, +you stay there forever. + +If you start in state 2, +you stay there forever. + +That's a very boring Markov +chain, but it's not very nice + +for the theory. + +So we're going to leave that +case out for the time being. + +But anyway, if you have that +case, then the chain has two + +recurrent classes. + +Lambda equals 1, has +multiplicity 2. + +You have two eigenvalues of +algebraic multiplicity 2. + +I mean, it's just one number, +but it appears twice in this + +determinant equation. + +And it also appears twice in +the sense that you have two + +recurrent classes. + +And you will find that there are +two linearly independent + +left eigenvectors, two linearly +independent right + +eigenvectors. + +And how do you find those? + +You use your common sense and +you say, well, if you start in + +state 1, you're always there. + +If you start in state 2, +you're always there. + +Why do I even look at +these two states? + +This is a crazy thing where +wherever I start, I stay there + +and I only look at state +1 or state 2. + +It's scarcely even +a Markov chain. + +If P12 and P21 are both 1, what +it means is you can never + +go from state 1 to state 1. + +You always go from state +1 to state 2. + +And you always go from +state 2 to state 1. + +It means you have a two-state +periodic chain. + +And that's the other +crazy case. + +The other case is not +very interesting. + +There's nothing stochastic +about it at all. + +So the chain is periodic. + +And if you look at this equation +here, the second + +eigenvalue is equal +to minus 1. + +I might as well tell you that, +in general, if you have a + +periodic Markov chain, just one +recurrent class and it's + +periodic, a period d, then the +eigenvalues turn out to be the + +uniformly spaced eigenvalues +around the unit circle. + +One is one of the eigenvalues. + +We've already seen that. + +And the other d minus 1 +eigenvalues are those + +uniformly spaced around +the unit circle. + +So they add up to 360 degrees +when you get all done with it. + +So that's an easy case. + +Proving that is tedious. + +It's done in the notes. + +It's not even done +in the notes. + +It's done in one of +the exercises. + +And you can do it +if you choose. + +So let's look at these +eigenvector equations and the + +eigenvalue equations. + +Incidentally, if you don't know +what the eigenvalues are, + +is this a linear set +of equations? + +No, it's a nonlinear +set of equations. + +This is a nonlinear set +of equations in pi + +1, pi 2, and lambda. + +How do you solve non-linear +equations like that? + +Well, if you have much sense, +you first find out what lambda + +is and then you solve +linear equations. + +And you can always do that. + +We've said that these solutions +for lambda, there + +can only be M of them. + +And you can find +them by solving + +this polynomial equation. + +Then you can solve the linear +equation by finding the + +eigenvectors. + +There are packages to do all +of these things, so there's + +nothing you should waste +time on doing here. + +It's just knowing what the +results are that's important. + +From now on, I'm going to assume +that P12 or P21 are + +greater than 0. + +In other words, I'm going to +assume that we don't have the + +periodic case and we don't have +the case where you have + +two classes of states. + +In other words, I'm going to +assume that our Markov chain + +is actually ergodic. + +That's the assumption that +I'm making here. + +If you then solve these +equations using lambda 1 + +equals 1, you'll find +out that pi 1 is the + +component sum to 1. + +First component is +P21 over the sum. + +Second component is +P12 over the sum. + +Not very interesting. + +Why is the steady state +probability weighted towards + +the largest of these transition +probabilities? + +If P21 is bigger than P12, how +do you know intuitively that + +you're going to be in state 1 +more than you're in state 2? + +Is this intuitively +obvious to-- yeah? + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: Because you make more +transistors from 2 to 1. + +Well, actually you don't make +more transitions from 2 to 1. + +You make exactly the same number +of transitions, but + +since the probability is higher, +it means you have to + +be in state 1 more +of the time. + +Good. + +So these are the two. + +And this is the left eigenvector +for the second + +eigenvalue-- + +namely, the smaller +eigenvalue. + +Now, if you look at these +equations, you'll notice that + +the vector pi, the left i-th +eigenvector, multiplied by the + +right j-th eigenvector, is +always equal to delta ij. + +In other words, the left +eigenvectors are orthogonal to + +the right eigenvectors. + +I mean, you can see this just +by multiplying it out. + +You multiply pi 1 times nu +1, and what do you get? + +You get this plus this, +which is 1. + +Delta 11 means there's something +which is 1 when i is + +equal j and 0 when i +is unequal to j. + +You take this and you +multiply it by this, + +and what do you get? + +You get P21 times P12 +over the square. + +Minus P12 times P21, it's 0. + +Same thing here. + +1 minus 1, that vector times +this vector, is 0 again. + +So the cross-terms are 0. + +The diagonal terms are 1. + +That's the way it is. + +So let's move on with this. + +These right eigenvector +equations, you can write them + +in matrix form. + +I'm doing this slowly. + +I hope I'm not boring those who +have done a lot of linear + +algebra too much. + +But they won't go on forever, +and it gets us to where we + +want to go. + +So if you take these two +equations and you write them + +in matrix form, what you get +is P times u, where u is a + +matrix whose columns are +the vector nu 1 and + +the vector nu 2. + +And capital lambda is the +diagonal matrix of the + +eigenvalues. + +If you multiply P times the +first column of u, and then + +you look at the first column of +this matrix, what you get-- + +yes, that's exactly the +right way to do it. + +And if you're not doing that, +you're probably not + +understanding it. + +But if you just think of +ordinary matrix vector + +multiplication, this +all works out. + +Because of this orthogonality +relationship, we see that the + +matrix whose rows are the left +eigenvectors times the matrix + +whose columns are the +right eigenvectors, + +that's equal to i. + +Namely, it's equal to +the identity matrix. + +That's what this orthogonality +relationship means. + +This means that this matrix is +the inverse of this matrix. + +This proves that u +is invertible. + +And in fact, we've done this +just for m equals 2. + +But in fact, this proof is +general and holds for + +arbitrary Markov chains if the +eigenvectors span the space. + +And we'll see that later. + +We're doing this for m equals +2 now, so we how to proceed + +when we have an arbitrary +Markov chain. + +u is invertible. + +u to the minus 1 has pi +1 and pi 2 as rows. + +And thus P is going +to be equal to-- + +I guess we should-- + +oh, we set it up here. + +P times u is equal to +u times lambda. + +We've shown here that u is +invertible, therefore we can + +multiply this equation +by u to the minus 1. + +And we get the transition matrix +P is equal to u times + +the diagonal matrix lambda +times the matrix u + +to the minus 1. + +What happens if we try +to find P squared? + +Well, it's u times lambda +times u to the minus 1. + +One of the nice things about +matrices is you can multiply + +them, if you don't +worry about the + +details, almost like numbers. + +Times u times lambda times +u to the minus 1. + +Except you don't have +commutativity. + +That's the only thing +that you don't have. + +But anyway, you have u times +lambda times u to the minus 1 + +times u times lambda times +u to t he minus 1. + +This and this turn out to be +the identity matrix, so you + +have u times lambda times +lambda, which is lambda + +squared, times u +to the minus 1. + +You still have this diagonal +matrix here, but the + +eigenvalues have all +been doubled. + +If you keep doing that +repeatedly, you find out that + +P to the n-- namely, this +long-term transition matrix, + +which is the thing we're +interested in-- + +is the matrix u times this +diagonal matrix, lambda to the + +n, times u to the minus 1. + +Equation 329 in the text has a +typo, and it should be this. + +It's given as u to the minus 1 +times lambda to the n times u, + +which is not at all right. + +That's probably the worst typo, +because if you try to + +say something from that, you'll +get very confused. + +You can solve one in general if +all the M eigenvalues are + +distinct as easily as +for M equals 2. + +This is still valid +so long as the + +eigenvectors span the space. + +So now the thing we want to +do is relatively simple. + +This lambda to the n is +a diagonal matrix. + +I can represent it as the sum +of M different matrices. + +And each of those matrices +has only one + +diagonal element, non-0. + +In other words, for the case +here, what we're doing is + +taking lambda 1, 0 to the n, +0 lambda 2 to the n, and + +representing this as lambda 1 to +the n, 0, 0, 0, plus 0, 0, + +0 lambda 2 to the n. + +So we have those trivial +matrices with u on the left + +side and u to the minus +1 on the right side. + +And we think of how to multiply +the matrix u, which + +is a matrix whose columns are +the eigenvectors, times this + +matrix with only one non-0 +element, times the matrix + +here, whose elements are +the left eigenvectors. + +And how do you do that? + +Well, if you do this for a +while, and you think of what + +this one element here times +a matrix whose rows are + +eigenvectors does, this non-0 +term in here picks out the + +appropriate row here. + +And this non-0 element +picks out the + +appropriate column here. + +So what that gives you is p to +the n is equal to the sum over + +the number of states in the +Markov chain times lambda sub + +i-- the i-th value to +the nth power-- + +times nu to the i times +pi to the i. + +pi to the i is the i-th +eigenvector of p. + +nu to the i is the i-th right +eigenvector of p. + +They have nothing +to do with n. + +The only thing that n affects +is this eigenvalue here. + +And what this is saying is that +p to the n is just the + +sum of eigenvalues which are, +if lambda is bigger than 1, + +this is exploding. + +If lambda 1 is less than +1, it's going to 0. + +And if lambda 1 is equal to +1, it's staying constant. + +If lambda 1 is complex but has +magnitude 1, then it's just + +gradually rotating around and +not doing much of interest at + +all, but it's going away. + +So that's what this +equation means. + +It says that we've converted the +problem of finding the nth + +power of p just to this problem +of finding the nth + +power of these eigenvalues. + +So we've made some +real progress. + +AUDIENCE: Professor, what +is nu i right here? + +PROFESSOR: What? + +AUDIENCE: What is nu i? + +PROFESSOR: nu sub i is the i-th +of the right eigenvectors + +of the matrix p. + +AUDIENCE: And pi i? + +PROFESSOR: And pi i is the +i-th left eigenvector. + +And what we've shown is that +these are orthogonal to each + +other, orthonormal. + +AUDIENCE: Can you please say +again what happens when lambda + +is complex? + +PROFESSOR: What? + +AUDIENCE: When lambda is +complex, what exactly happens? + +PROFESSOR: Oh, if lambda i is +complex and the magnitude is + +less than 1, it just +dies away. + +if the magnitude is bigger than +1, it explodes, which + +will be very strange. + +And we'll see that +can't happen. + +And if the magnitude is 1, as +you take powers of a complex + +number of magnitude 1, I mean, +it start out here, it goes + +here, then here. + +I mean, it just rotates around +in some crazy way. + +But it maintains its magnitude +as being equal + +to 1 all the time. + +So this is just repeating +what we had before. + +These are the eigenvectors. + +If you calculate this very +quickly using this and this, + +and if you recognize that the +right eigenvector, nu 2, is + +the first part of it is pi sub +2, the second part of it minus + +pi sub 1, where pi is just this +first eigenvector here. + +So if you do this +multiplication, you find that + +nu to the 1-- + +oh, I thought I had all +of these things out. + +This should be nu. + +The first right eigenvector +times the first left + +eigenvector. + +Oh, but this is all right, +because I'm saying the first + +left eigenvector is a steady +state vector, which is the + +thing we're interested in. + +That's pi 1, pi 2, pi 1, +pi 2, where pi 1 is + +this and pi 2 is this. + +nu 2 times pi 2 is just this. + +So when we calculate p sub n, +we get pi 1 plus pi 2 times + +this eigenvalue to +the nth power. + +Pi 1 minus pi 1, lambda +2 to the nth power. + +pi 2 and pi 2 is what we get +for the main eigenvalue. + +This is what we get for +the little eigenvalue. + +This little eigenvalue here is +1 minus P12 minus P21, which + +has magnitude less than 1, +unless we either have the + +situation where P12 is equal to +P21 is equal to 0, or both + +of them are 1. + +So these are the terms +that go to 0. + +This solution is exact. + +There were no approximations +in here. + +Before, when we analyzed what +happened to P to the n, we saw + +that we converged, but +we didn't really + +see how fast we converged. + +Now we know how fast +we converge. + +The rate of convergence is +the value of this second + +eigenvalue here. + +And that's a pretty +general result. + +You converged like the +second-largest eigenvalue. + +And we'll see how +that works out. + +Now, let's go on to the case +where you have an arbitrary + +number of states. + +We've almost solved that +already, because as we were + +looking at the case with two +states, we were doing most of + +the things in general. + +If you have an n state Markov +chain, a determinant of P + +minus lambda is a polynomial +of degree M in lambda. + +That was what we said +a while ago. + +It has M roots, eigenvalues. + +And here, we're going to assume +that those roots are + +all distinct. + +So we don't have to worry +about what happens with + +repeated roots. + +Each eigenvalue lambda sub i-- +there are M of them now-- + +has a right eigenvector, +nu sub i, and a left + +eigenvector, pi sub i. + +And we have seen that-- + +well, we haven't seen it yet. + +We're going to show +it in a second. + +pi super i times nu super +j is equal to j for each + +ij unequal to i. + +If you scale either this or +that, when you saw this + +eigenvector equation, you have +a pi on both sides or a nu on + +both sides, and you have a scale +factor which can't be + +determined from the eigenvector +equation. + +So you have to choose that +scaling factor somehow. + +If we choose the scaling factor +appropriately, we get + +pi, the i-th left eigenvector, +times the i-th right + +eigenvector. + +This is just a number now. + +It's that times that. + +We can scale things, so +that's equal to 1. + +Then as before, let u be the +matrix with columns nu 1 to nu + +M, and let v have the rows, pi +1 to pi M. Because of this + +orthogonality relationship we've +set up, v times u is + +equal to i. + +So again, the left eigenvector +rows forms a matrix which is + +the inverse of the right +eigenvector columns. + +So that says v is equal +to u to the minus 1. + +Thus the eigenvector is nu, the +first right eigenvector up + +to the nth right eigenvector, +these are linearly + +independent. + +And they span M space. + +That's a very peculiar +thing we've done. + +We've said we have all these +M right eigenvectors. + +We don't know anything about +them, but what we do know is + +we also have M left +eigenvectors. + +And the left eigenvectors, as +we're going to show in just a + +second, are orthogonal to +the right eigenvectors. + +And therefore, when we look at +these two matrices, we can + +multiply them and get +the identity matrix. + +And that means that the right +eigenvectors have to be-- + +when we look at the matrix of +the right eigenvectors, is + +non-singular. + +Very, very peculiar argument. + +I mean, we find out that those +right eigenvectors span the + +space, not by looking at the +right eigenvectors, but by + +looking at how they relate +to the left eigenvectors. + +But anyway, that's perfectly +all right. + +And so long as we can show +that we can satisfy this + +orthogonality condition, then in +fact all this works out. v + +is equal to u to the minus 1. + +These eigenvectors are linearly +independent and they + +span M space. + +Same here. + +And putting these equations +together, P times u equals u + +times lambda. + +This is exactly what +we did before. + +Post-multiplying by u to the +minus 1, we get P equals u + +times lambda times +u to the minus 1. + +P to the n is then u times +lambda to the n times u + +to the minus 1. + +All this stuff about convergence +is all revolving + +down to simply the question +of what happens to these + +eigenvalues. + +I mean, there's a mess first, +finding out what all these + +right eigenvectors are and +what all these left + +eigenvectors are. + +But once you do that, P to the +n is just looking at this + +quantity, breaking up +lambda to the n + +the way we did before. + +P to the n is just +this sum here. + +Now, each row of P sums to 1, so +e is a right eigenvector of + +eigenvalue 1. + +So we have a theorem that says +the left eigenvector pi of + +eigenvalue 1 is a steady state +vector if it's normalized to + +pi times e equals 1. + +So we almost did that before, +but now we want to be a little + +more careful about it. + +Oh, excuse me. + +The theorem is that the left +eigenvector pi is a steady + +state vector if it's normalized +in this way. + +In other words, we know that +there is a left eigenvector + +pi, which has eigenvalue 1, +because there's a right + +eigenvector. + +If there's a right eigenvector, +there has to be a + +left eigenvector. + +What we don't know is +that pi actually has + +non-negative terms. + +So that's the thing +we want to show. + +The proof is, there must be +a left eigenvector pi for + +eigenvalue 1. + +We already know that. + +For every j, Pi sub j is equal +to the sum over k times pi sub + +k times p sub kj. + +We don't know whether these +are complex or real. + +We don't know whether they're +positive or negative, if + +they're real. + +But we do know that since they +satisfy this eigenvector + +equation, they satisfy +this equation. + +If I take the magnitudes +of all of these + +things, what do I get? + +The magnitude on this side +is pi sub j magnitude. + +This is less than or equal to +the sum of the magnitudes of + +these terms. + +If you take two complex numbers +and you add them up, + +you get something which, in +magnitude, is less than or + +equal to the sum of +the magnitudes. + +It might sound strange, +but if you look + +in the complex plane-- + +imaginary, real-- + +and you look at one complex +number, and you add it to + +another complex number, this +distance here is less than or + +equal to this magnitude +plus this magnitude. + +That's all that equation +is saying. + +And this is equal to this +distance plus this distance if + +and only if each of these +components of the eigenvector + +that we're talking about, if and +only if those components + +are all heading off in +the same direction + +in the complex plane. + +Now what do we do? + +Well, you look at this for a +while and you say, OK, what + +happens if I sum this +inequality over j? + +Well, if I sum this +over j, I get one. + +And therefore when I sum both +sides over j, the sum over j + +of the magnitudes of these +eigenvector components is less + +than or equal to the sum over +k of the magnitude. + +This is the same as this. + +This j is just a dummy +index of summation. + +This is a dummy index +of summation. + +Obviously, this is less +than or equal to this. + +But what's interesting here is +that this is equal to this. + +And the only way this can be +equal to this is if every one + +of these things are satisfied +with equality. + +If any one of these are +satisfied with inequality, + +then when you add them all up, +this will be satisfied with + +inequality also, which +is impossible. + +So all of these are satisfied +with equality, which says that + +the magnitude of pi sub j, the +vector whose elements are the + +magnitudes of this thing we +started with, in fact form a + +steady state vector if we +normalize them to 1. + +It says these magnitudes +satisfy the + +steady state equation. + +These magnitudes are real +and they're positive. + +So when we normalize them to +sum to 1, we have a steady + +state vector. + +And therefore the left +eigenvector pi of eigenvalue 1 + +is a steady state vector if it's +normalized to pi times e + +equals 1, which is the way we +want to normalize them. + +So there always is a steady +state vector for every + +finite-state Markov chain. + +So this is a non-negative vector +satisfying a steady + +state vector equation. + +And normalizing it, we have +a steady state vector. + +So we've demonstrated the +existence of a left + +eigenvector which is a +steady state vector. + +Another theorem is that every +eigenvalue satisfies lambda, + +magnitude of the eigenvalue is +less than or equal to 1. + +This, again, is sort of obvious, +because if you have + +an eigenvalue which is bigger +than 1 and you start taking + +powers of it, it starts marching +off to infinity. + +Now, you might say, maybe +something else + +is balancing that. + +But since you only have a finite +number of these things, + +that sounds pretty weird. + +And in fact, it is. + +So the proof of this is, we want +to assume that pi super l + +is the l-th of these +eigenvectors of P. Its + +eigenvalue is lambda sub l. + +It also is a left eigenvector of +P to the n with eigenvalue + +lambda to the n. + +That's what we've +shown before. + +I mean, you can multiply this +matrix P, and all you're doing + +is just taking powers +of the eigenvalue. + +So if we start out with lambda +to the n, let's forget about + +the l's, because we're just +looking at a fixed l now. + +Lambda to the nth power times +the j-th component of pi is + +equal to the sum over i of the +i-th component of pi times Pij + +to the n, for all j. + +Now I take the magnitude of +everything is before. + +The magnitude of this is, again, +less than or equal to + +the magnitude of this. + +I want to let beta be the +largest of these quantities. + +And when I put that maximizing +j in here, lambda to the l + +times beta is less than or equal +to the sum over i of-- + +I can upper-bound +these by beta. + +So I wind up with lambda to the +l times beta is less than + +or equal to the sum over i of +beta times Pij to the n. + +I don't know what these powers +are, but they're certainly + +less than or equal to 1. + +So lambda sub l is less +than or equal to n. + +That's what this said. + +When you take this magnitude of +the l-th eigenvalue, it's + +less than or equal +to this number n. + +Now, if this number were larger +than 1, if it was 1 + +plus 10 to the minus sixth, +and you multiplied it by a + +large enough number n, that +this would grow to be + +arbitrarily large. + +It can't grow to be arbitrarily +large, therefore + +the magnitude of lambda +sub l has to be less + +than or equal to 1. + +Tedious proof, but +unfortunately, the notes just + +assume this. + +Maybe I had some good, simple +reason for it before. + +I don't have any now, so I have +to go through a proof. + +Anyway, these two theorems, if +you look at them, are valid + +for all finite-state +Markov chains. + +There was no place that we +used the fact that we had + +anything with distinct +eigenvalues or anything. + +But now when we had distinct +eigenvalues, we have the nth + +power of P is the sum here again +over right eigenvectors + +times left eigenvectors. + +When you take a right +eigenvector, which is a column + +vector, times a left +eigenvector, which is a row + +vector, you get an +M by M matrix. + +I don't know what that matrix +is, but it's a matrix. + +It's a fixed matrix +independent of n. + +And the only thing that's +varying with n is these + +eigenvalues. + +These quantities are less +than or equal to 1. + +So if the chain is an ergodic +unit chain, we've already seen + +that one eigenvalue is 1, and +the rest of the eigenvalues + +are strictly less than +1 in magnitude. + +We saw that by showing that for +an ergodic unit chain, P + +to the n converged. + +So the rate at which P to the +n approaches e times pi is + +going to be determined +by the second-largest + +eigenvalue in here. + +And that second-largest +eigenvalue is going to be less + +than 1, strictly less than 1. + +We don't know what it is. + +Before, we knew this convergence +here for an + +ergodic unit chain +is exponential. + +Now we know that it's +exponential and we know + +exactly how fast it goes, +because the speed of + +convergence is just the +second-largest eigenvalue. + +If you want to know how fast P +to the n approaches e times + +the steady state vector pi, +all you have to do is find + +that second-largest eigenvalue, +and that tells you + +how fast the convergence is, +except for calculating these + +things, which are just fixed. + +If P is a periodic unit chain +with period d, then if you + +read the notes-- + +you should read the notes-- + +there are d eigenvalues +equally spaced + +around the unit circle. + +P to the n doesn't converge. + +The only thing you can say here +is, what happens if you + +look at P to the d-th power? + +And you can imagine what happens +if you look at P to + +the d-th power without +doing any analysis. + +I mean, we know that what +happens in a periodic chain is + +that you rotate from one set +of states to another set of + +states to another set of states +to another set of + +states, and then back +to the set of + +states you started with. + +And you keep rotating around. + +Now, there are d sets of states +going around here. + +What happens if I +take P to the d? + +P to the d is looking at +the d-step transitions. + +So it's looking at, if you start +here, after d steps, + +you're back here again, +after d steps, + +you're back here again. + +So the matrix, P to the d, is +in fact the matrix of d + +ergodic subclasses. + +And for each one of them, +whatever subclass you start + +in, you stay in that +subclass forever. + +So the analysis of a periodic +unit chain, really the classy + +way to do it is to look +at P to the d and see + +what happens there. + +And you see that you get +convergence within each + +subclass, but you just keep +rotating among subclasses. + +So there's nothing very +fancy going on there. + +You just rotate from one +subclass to another. + +And that's the way it is. + +And P to the n doesn't +converge. + +But P to the d times +n does converge. + +Now, let's look at the next-most +complicated state. + +Suppose we have M states and +we have M independent + +eigenvectors. + +OK, remember I told you that +there was a very ugly thing in + +linear algebra that said, when +you had an eigenvalue of + +multiplicity k, you might not +have k linearly independent + +eigenvectors. + +You might have a smaller +number of them. + +We'll look at an example +of that later. + +But here, I'm saying, let's +forget about that case, + +because it's ugly. + +Let's assume that whatever +multiplicity each of these + +eigenvalues has, if you have +an eigenvalue with + +multiplicity k, then you have +k linearly independent right + +eigenvectors and k linearly +independent left eigenvectors + +to correspond to that. + +And then when you add up all of +the eigenvectors, you have + +M linearly independent +eigenvectors. + +And what happens when you have M +linearly independent vectors + +in a space of dimension M? + +If you have M linearly +independent vectors in a space + +of dimension N, you expand the +whole space, which says that + +the vector of these eigenvectors +is in fact + +non-singular, which says, again, +we can do all of the + +stuff we did before. + +There's a little bit of a trick +in showing that the left + +eigenvectors and the right +eigenvectors can be made + +orthogonal. + +But aside from that, +P to the n is again + +equal to the same form. + +And what this form says is, if +all of the eigenvalues except + +one are less than 1, then you're +again going to approach + +steady state. + +What does that mean? + +Suppose I have more than one +ergodic chain, more than one + +ergodic class, or suppose I +have a periodic class or + +something else. + +Is it possible to have one +eigenvalue equal to 1 and all + +the other eigenvalues +be smaller? + +If there's one eigenvalue that's +equal to 1, according + +to this formula here, eventually +P to the n + +converges to that one +value equal to 1. + +And right eigenvector +can be taken as e. + +Left eigenvector can be taken +as a steady state vector pi. + +And we have the case +of convergence. + +Can you have convergence to all +the rows being the same if + +you have multiple +ergodic classes? + +No. + +If you have multiple ergodic +classes and you start out in + +one class, you stay there. + +You can't get out of it. + +If you have a periodic class +and you start out in that + +periodic class, you can't +have convergence there. + +So in this situation here, where +all the eigenvalues are + +distinct, you can only have +one eigenvalue equal to 1. + +Here, when we're going to this +more general case, we might + +have more than one eigenvalue +equal to 1. + +But if in fact we only have one +eigenvalue equal to 1, and + +all the others are strictly +smaller in magnitude, then in + +fact you're just talking about +this case of an ergodic unit + +chain again. + +It's the only place +you can be. + +So let's look at an +example of this. + +Suppose you have a Markov +chain which has l + +ergodic sets of states. + +You have one set of states. + +So we have one set of states +over here, which will all go + +back and forth to each other. + +Then another set of +states over here. + +Let's let l equal +2 in this case. + +So what happens in +this situation? + +We'll have to work quickly +before it gets up. + +Anybody with any sense, faced +with a Markov chain like this, + +would say if we start here, +we're going to stay here, if + +we start here, we're +going to stay here. + +Let's just analyze this first. + +And then after we're done +analyzing this, + +we'll analyze this. + +And then we'll put the +whole thing together. + +And what we will find is +a transition matrix + +which looks like this. + +And if you're here, +you stay here. + +If you're here, you stay here. + +We can find the eigenvalues +and eigenvectors of this. + +We can find the eigenvalues +and eigenvectors of this. + +If you look at this crazy +formula for finding + +determinants, what you're stuck +with is permutations + +within here times permutations +within here. + +So the eigenvalues that you wind +up with are products of + +the two eigenvalues. + +Or any eigenvalue here is an +eigenvalue of the whole thing. + +Any eigenvalue here is an +eigenvalue of the whole thing. + +And we just look at the sum of +the number of eigenvalues here + +and the number there. + +So we have a very boring +case here. + +Each ergodic set has an +eigenvalue equal to 1, has a + +right eigenvector equal to 1. + +When the steps of that state +and 0 elsewhere. + +There's also a steady state +vector on that set of states. + +We've already seen that. + +So P to the n converges to a +block diagonal matrix, where + +for each ergodic set, the rows +within that set are the same. + +So P to the n then +is pi 1, pi 1. + +And then here, we have +pi 2, pi 2, pi 2. + +So that's all that +can happen here. + +This is limit. + +So one message of this is that, +after you understand + +ergodic unit chains, you +understand almost everything. + +You still have to worry about +periodic unit chains. + +But you just take a power of +them, and then you have + +ergodic sets of states. + +one final thing. + +Good, I have five minutes +to talk about this. + +I don't want any more time to +talk about it, because I'll + +get terribly confused if I do. + +And it's a topic which, if you +want to read more about it, + +read about it in Strang. + +He obviously doesn't like +the topic either. + +Nobody likes the topic. + +Strang at least was driven to +say something clear about it. + +Most people don't even +bother to say + +something clear about it. + +There's a theorem, due to, I +guess, Jordan, because it's + +called a Jordan form. + +And what Jordan said is, in +the nice cases we talked + +about, you have this +decomposition of the + +transition matrix in P into a +matrix here whose columns are + +the right eigenvectors times +a matrix here, which is a + +diagonal matrix with the +eigenvalues along it. + +And this, finally, is a matrix +which is the inverse of this, + +and, which properly normalized, +is the left + +eigenvectors of P. And you can +replace this form by what's + +called a Jordan form, where P +is equal to some matrix u + +times the Jordan form matrix +j times the inverse of u. + +Now, u is no longer the +right eigenvectors. + +It can't be the right +eigenvectors, because when we + +needed Jordan form, we don't +have enough right eigenvectors + +to span the space. + +So it has to be something +else. + +And like everyone else, +we say, I don't care + +what that matrix is. + +Jordan proved that there is such +a matrix, and that's all + +we want to know. + +The important thing is that this +matrix j in here is as + +close as you can get it. + +It's a matrix, which along the +main diagonal, has all the + +eigenvalues with their +appropriate multiplicity. + +Namely, lambda 1 is +an eigenvalue with + +multiplicity 2. + +Lambda 2 is an eigenvalue +of multiplicity 3. + +And in this situation, you have +two eigenvectors here, so + +nothing appears up there. + +With this multiplicity 3 +eigenvalue, there are only two + +linearly independent +eigenvectors. + +And therefore Jordan says, why +don't we stick a 1 in here and + +then solve everything else? + +And his theorem says, if you +do that, it in fact works. + +So every time-- + +well, the eigenvalue is on the +main diagonal, the ones on the + +next diagonal up, the only place +would be anything non-0 + +is on the main diagonal in this +form, and on the next + +diagonal up, where you +occasionally have a 1. + +And the 1 is to replace +the need for deficient + +eigenvectors. + +So every time you have a +deficient eigenvector, you + +have some 1 appearing there. + +And then there's a way +to solve for u. + +And I don't have any idea what +it is, and I don't care. + +But if you get interested in it, +I think that's wonderful. + +But please don't tell +me about it. + +Nice example of this is +this matrix here. + +What happens if you try to +take the determinant of P + +minus lambda i? + +Well, you have 1/2 minus lambda, +1/2 minus lambda, 1 + +minus lambda. + +What are all the permutations +here that you can take? + +There's the permutation of +the main diagonal itself. + +If I try to include that +element, there's nothing I can + +do but have some element +down here. + +And all these elements are 0. + +So those elements don't +contribute to a + +determinant at all. + +So I have one eigenvalue +which is equal to 1. + +I have two values at +multiplicity 2, eigenvalue + +which is 1/2. + +If you try to find the +eigenvector here, you find + +there is only one. + +So in fact, this corresponds +to a Jordan form, + +where you have 1/2. + +1, and a 0, and a 1 here, +and 0 everywhere else. + +And now if I want to find P to +the n, I have u times this j + +times u to the minus +1 times u. + +All the u's in the middle +cancel out, so I wind up + +eventually with u times j +to the nth power times u + +to the minus 1. + +What is j to the nth power? + +What happens if I multiply this +matrix by itself n times? + +Well, it turns out that what +happens is that this main + +diagonal here, you wind +up with a 1/4 and + +then 1/8 and so forth. + +This term here, it goes +down exponential. + +Well, if you multiply this by +itself, eventually, you can + +see what's going on here more +easily if you draw the Markov + +chain for it. + +You have state 1, state +2, and state 3. + +State 1, there's a transition +1/2 and a transition 1/2. + +State 2, there's a transition +1/2 and a transition 1/2, And + +state 3, you just stay there. + +So the amount of time that it +takes you to get to steady + +state is the amount of +time it takes you-- + +you start in state 1. + +You've got to make this +transition eventually, and + +then you've got to make this +transition eventually. + +And the amount of time that it +takes you to do that is the + +sum of the amount of time it +takes you to go there, plus + +the amount of time that +it takes to go there. + +So you have two random +variables. + +One is the time to go here. + +The other is the time +to go here. + +Both of those are geometrically +decreasing + +random variables. + +When we convolve those things +with each other, what we get + +is an extra term n. + +So we get an n times +1/2 to the n. + +So the thing which is different +in the Jordan form + +is, instead of having an +eigenvalue to the nth power, + +you have an eigenvalue times-- + +if there's only a single one +there, there's an n there. + +If there are two 1s both +together, you get an n times n + +minus 1, and so forth. + +So worst case, you've got a +polynomial to the nth power + +times an eigenvalue. + +For all practical purposes, this +is still the eigenvalue + +going down exponentially. + +So for all practical purposes, +what you wind up with is the + +second-largest eigenvalue still +determines how fast you + +get convergence. + +Sorry, I took eight minutes +talking about the Jordan form. + +I wanted to take five minutes +talking about it. + +You can read more about +it in the notes. \ No newline at end of file diff --git a/GOmLwHaa8Ik.txt b/GOmLwHaa8Ik.txt new file mode 100644 index 0000000000000000000000000000000000000000..4d0a928719017a443b5547d41b749ca90122627b --- /dev/null +++ b/GOmLwHaa8Ik.txt @@ -0,0 +1,1051 @@ +align:start position:0% + +by now we have defined the notion of + + align:start position:0% +by now we have defined the notion of + + + align:start position:0% +by now we have defined the notion of +independence of events and also the + + align:start position:0% +independence of events and also the + + + align:start position:0% +independence of events and also the +notion of independence of random + + align:start position:0% +notion of independence of random + + + align:start position:0% +notion of independence of random +variables the two definitions look + + align:start position:0% +variables the two definitions look + + + align:start position:0% +variables the two definitions look +fairly similar but the details are not + + align:start position:0% +fairly similar but the details are not + + + align:start position:0% +fairly similar but the details are not +exactly the same because the two + + align:start position:0% +exactly the same because the two + + + align:start position:0% +exactly the same because the two +definitions refer to different + + align:start position:0% +definitions refer to different + + + align:start position:0% +definitions refer to different +situations for two events we know what + + align:start position:0% +situations for two events we know what + + + align:start position:0% +situations for two events we know what +it means for them to be independence the + + align:start position:0% +it means for them to be independence the + + + align:start position:0% +it means for them to be independence the +probability of their intersection is the + + align:start position:0% +probability of their intersection is the + + + align:start position:0% +probability of their intersection is the +product of their individual + + align:start position:0% +product of their individual + + + align:start position:0% +product of their individual +probabilities now to make a relation + + align:start position:0% +probabilities now to make a relation + + + align:start position:0% +probabilities now to make a relation +with random variables we introduced the + + align:start position:0% +with random variables we introduced the + + + align:start position:0% +with random variables we introduced the +so called indicator random variables so + + align:start position:0% +so called indicator random variables so + + + align:start position:0% +so called indicator random variables so +for example the random variable X is + + align:start position:0% +for example the random variable X is + + + align:start position:0% +for example the random variable X is +defined to be equal to 1 if event a + + align:start position:0% +defined to be equal to 1 if event a + + + align:start position:0% +defined to be equal to 1 if event a +occurs and to be equal to 0 if event + + align:start position:0% +occurs and to be equal to 0 if event + + + align:start position:0% +occurs and to be equal to 0 if event +does not occur and there is a similar + + align:start position:0% +does not occur and there is a similar + + + align:start position:0% +does not occur and there is a similar +definition for random variable Y in + + align:start position:0% +definition for random variable Y in + + + align:start position:0% +definition for random variable Y in +particular the probability that random + + align:start position:0% +particular the probability that random + + + align:start position:0% +particular the probability that random +variable X takes the value of 1 this is + + align:start position:0% +variable X takes the value of 1 this is + + + align:start position:0% +variable X takes the value of 1 this is +the probability that event a occurs it + + align:start position:0% +the probability that event a occurs it + + + align:start position:0% +the probability that event a occurs it +turns out that the independence of the + + align:start position:0% +turns out that the independence of the + + + align:start position:0% +turns out that the independence of the +two events a and B is equivalent to the + + align:start position:0% +two events a and B is equivalent to the + + + align:start position:0% +two events a and B is equivalent to the +independence of the two indicator random + + align:start position:0% +independence of the two indicator random + + + align:start position:0% +independence of the two indicator random +variables and there is a similar + + align:start position:0% +variables and there is a similar + + + align:start position:0% +variables and there is a similar +statement which is true more generally + + align:start position:0% +statement which is true more generally + + + align:start position:0% +statement which is true more generally +that is and events are independent if + + align:start position:0% +that is and events are independent if + + + align:start position:0% +that is and events are independent if +and only if be associated an indicator + + align:start position:0% +and only if be associated an indicator + + + align:start position:0% +and only if be associated an indicator +random variables are independent this is + + align:start position:0% +random variables are independent this is + + + align:start position:0% +random variables are independent this is +a useful statement because it allows us + + align:start position:0% +a useful statement because it allows us + + + align:start position:0% +a useful statement because it allows us +to sometimes instead of manipulating + + align:start position:0% +to sometimes instead of manipulating + + + align:start position:0% +to sometimes instead of manipulating +events to manipulate random variables + + align:start position:0% +events to manipulate random variables + + + align:start position:0% +events to manipulate random variables +and vice versa and depending on the + + align:start position:0% +and vice versa and depending on the + + + align:start position:0% +and vice versa and depending on the +context one may be easier than the other + + align:start position:0% +context one may be easier than the other + + + align:start position:0% +context one may be easier than the other +now the intuitive content is that event + + align:start position:0% +now the intuitive content is that event + + + align:start position:0% +now the intuitive content is that event +a and B are independent if the + + align:start position:0% +a and B are independent if the + + + align:start position:0% +a and B are independent if the +occurrence of event a does not change + + align:start position:0% +occurrence of event a does not change + + + align:start position:0% +occurrence of event a does not change +your beliefs about B and in terms of + + align:start position:0% +your beliefs about B and in terms of + + + align:start position:0% +your beliefs about B and in terms of +random variables one random variable + + align:start position:0% +random variables one random variable + + + align:start position:0% +random variables one random variable +taking a certain value which indicates + + align:start position:0% +taking a certain value which indicates + + + align:start position:0% +taking a certain value which indicates +whether event a has occurred or not does + + align:start position:0% +whether event a has occurred or not does + + + align:start position:0% +whether event a has occurred or not does +not give you any information about the + + align:start position:0% +not give you any information about the + + + align:start position:0% +not give you any information about the +other random variable which would tell + + align:start position:0% +other random variable which would tell + + + align:start position:0% +other random variable which would tell +you whether event B has occurred or not + + align:start position:0% +you whether event B has occurred or not + + + align:start position:0% +you whether event B has occurred or not +it is instructive now to go through the + + align:start position:0% +it is instructive now to go through the + + + align:start position:0% +it is instructive now to go through the +derivation of this + + align:start position:0% +derivation of this + + + align:start position:0% +derivation of this +at least for the case of two events + + align:start position:0% +at least for the case of two events + + + align:start position:0% +at least for the case of two events +because it gives us perhaps some + + align:start position:0% +because it gives us perhaps some + + + align:start position:0% +because it gives us perhaps some +additional understanding about the + + align:start position:0% +additional understanding about the + + + align:start position:0% +additional understanding about the +precise content of the definitions we + + align:start position:0% +precise content of the definitions we + + + align:start position:0% +precise content of the definitions we +have introduced so let us suppose that + + align:start position:0% +have introduced so let us suppose that + + + align:start position:0% +have introduced so let us suppose that +random variables x and y are independent + + align:start position:0% +random variables x and y are independent + + + align:start position:0% +random variables x and y are independent +what does that mean independence means + + align:start position:0% +what does that mean independence means + + + align:start position:0% +what does that mean independence means +that the joint pmf of the two random + + align:start position:0% +that the joint pmf of the two random + + + align:start position:0% +that the joint pmf of the two random +variables x and y factors as a product + + align:start position:0% +variables x and y factors as a product + + + align:start position:0% +variables x and y factors as a product +of the corresponding marginal pmfs and + + align:start position:0% +of the corresponding marginal pmfs and + + + align:start position:0% +of the corresponding marginal pmfs and +this factorization must be true no + + align:start position:0% +this factorization must be true no + + + align:start position:0% +this factorization must be true no +matter what arguments we use inside the + + align:start position:0% +matter what arguments we use inside the + + + align:start position:0% +matter what arguments we use inside the +joint pmf and the combination of x and y + + align:start position:0% +joint pmf and the combination of x and y + + + align:start position:0% +joint pmf and the combination of x and y +in this instance have a total of four + + align:start position:0% +in this instance have a total of four + + + align:start position:0% +in this instance have a total of four +possible values these are the + + align:start position:0% +possible values these are the + + + align:start position:0% +possible values these are the +combinations of zeros and ones that we + + align:start position:0% +combinations of zeros and ones that we + + + align:start position:0% +combinations of zeros and ones that we +can form and for this reason we have a + + align:start position:0% +can form and for this reason we have a + + + align:start position:0% +can form and for this reason we have a +total of four equations these four + + align:start position:0% +total of four equations these four + + + align:start position:0% +total of four equations these four +equality's are what is required for x + + align:start position:0% +equality's are what is required for x + + + align:start position:0% +equality's are what is required for x +and y to be independent so suppose that + + align:start position:0% +and y to be independent so suppose that + + + align:start position:0% +and y to be independent so suppose that +this is true the trend that the random + + align:start position:0% +this is true the trend that the random + + + align:start position:0% +this is true the trend that the random +variables are independent let us take + + align:start position:0% +variables are independent let us take + + + align:start position:0% +variables are independent let us take +this first relation and write it in + + align:start position:0% +this first relation and write it in + + + align:start position:0% +this first relation and write it in +probability notation the random variable + + align:start position:0% +probability notation the random variable + + + align:start position:0% +probability notation the random variable +X taking the value of 1 that's the same + + align:start position:0% +X taking the value of 1 that's the same + + + align:start position:0% +X taking the value of 1 that's the same +as event a occurring and random variable + + align:start position:0% +as event a occurring and random variable + + + align:start position:0% +as event a occurring and random variable +Y taking the value of 1 that's the same + + align:start position:0% +Y taking the value of 1 that's the same + + + align:start position:0% +Y taking the value of 1 that's the same +as event B occurring so the joint PMF + + align:start position:0% +as event B occurring so the joint PMF + + + align:start position:0% +as event B occurring so the joint PMF +evaluated at 1 1 is the probability that + + align:start position:0% +evaluated at 1 1 is the probability that + + + align:start position:0% +evaluated at 1 1 is the probability that +events a and B both occur on the other + + align:start position:0% +events a and B both occur on the other + + + align:start position:0% +events a and B both occur on the other +side of the equation we have the + + align:start position:0% +side of the equation we have the + + + align:start position:0% +side of the equation we have the +probability that X is equal to 1 which + + align:start position:0% +probability that X is equal to 1 which + + + align:start position:0% +probability that X is equal to 1 which +is a probability that a occurs and + + align:start position:0% +is a probability that a occurs and + + + align:start position:0% +is a probability that a occurs and +similarly the probability that B occurs + + align:start position:0% +similarly the probability that B occurs + + + align:start position:0% +similarly the probability that B occurs +but if this is true then by definition a + + align:start position:0% +but if this is true then by definition a + + + align:start position:0% +but if this is true then by definition a +and B are independent events so we have + + align:start position:0% +and B are independent events so we have + + + align:start position:0% +and B are independent events so we have +verified one direction of the statement + + align:start position:0% +verified one direction of the statement + + + align:start position:0% +verified one direction of the statement +if the random variables are independent + + align:start position:0% +if the random variables are independent + + + align:start position:0% +if the random variables are independent +then events a and B are independent now + + align:start position:0% +then events a and B are independent now + + + align:start position:0% +then events a and B are independent now +we would like to verify the reverse + + align:start position:0% +we would like to verify the reverse + + + align:start position:0% +we would like to verify the reverse +statement so suppose that events a and B + + align:start position:0% +statement so suppose that events a and B + + + align:start position:0% +statement so suppose that events a and B +are independent in that case this + + align:start position:0% +are independent in that case this + + + align:start position:0% +are independent in that case this +relation is true and as we just argued + + align:start position:0% +relation is true and as we just argued + + + align:start position:0% +relation is true and as we just argued +this relation is the + + align:start position:0% +this relation is the + + + align:start position:0% +this relation is the +as this relation but just written in + + align:start position:0% +as this relation but just written in + + + align:start position:0% +as this relation but just written in +different notation so we have song that + + align:start position:0% +different notation so we have song that + + + align:start position:0% +different notation so we have song that +if a and B are independent this relation + + align:start position:0% +if a and B are independent this relation + + + align:start position:0% +if a and B are independent this relation +will be true but how about the remaining + + align:start position:0% +will be true but how about the remaining + + + align:start position:0% +will be true but how about the remaining +three relations we have more work to do + + align:start position:0% +three relations we have more work to do + + + align:start position:0% +three relations we have more work to do +here's how we can proceed if a and B are + + align:start position:0% +here's how we can proceed if a and B are + + + align:start position:0% +here's how we can proceed if a and B are +independent we have shown some time ago + + align:start position:0% +independent we have shown some time ago + + + align:start position:0% +independent we have shown some time ago +that events a and B complement will also + + align:start position:0% +that events a and B complement will also + + + align:start position:0% +that events a and B complement will also +be independent intuitively a doesn't + + align:start position:0% +be independent intuitively a doesn't + + + align:start position:0% +be independent intuitively a doesn't +tell you anything about B occurring or + + align:start position:0% +tell you anything about B occurring or + + + align:start position:0% +tell you anything about B occurring or +not + + align:start position:0% +not + + + align:start position:0% +not +so a does not tell you anything about + + align:start position:0% +so a does not tell you anything about + + + align:start position:0% +so a does not tell you anything about +whether B complement will occur or not + + align:start position:0% +whether B complement will occur or not + + + align:start position:0% +whether B complement will occur or not +now these two events being independent + + align:start position:0% +now these two events being independent + + + align:start position:0% +now these two events being independent +by the definition of Independence we + + align:start position:0% +by the definition of Independence we + + + align:start position:0% +by the definition of Independence we +have that the probability of a + + align:start position:0% +have that the probability of a + + + align:start position:0% +have that the probability of a +intersection with B complement is the + + align:start position:0% +intersection with B complement is the + + + align:start position:0% +intersection with B complement is the +product of the probabilities of a and of + + align:start position:0% +product of the probabilities of a and of + + + align:start position:0% +product of the probabilities of a and of +B complement and then we realize that + + align:start position:0% +B complement and then we realize that + + + align:start position:0% +B complement and then we realize that +this equality is written in PMF notation + + align:start position:0% +this equality is written in PMF notation + + + align:start position:0% +this equality is written in PMF notation +corresponds exactly to this equation + + align:start position:0% +corresponds exactly to this equation + + + align:start position:0% +corresponds exactly to this equation +here a event a corresponds to X taking + + align:start position:0% +here a event a corresponds to X taking + + + align:start position:0% +here a event a corresponds to X taking +the value of one event B complement + + align:start position:0% +the value of one event B complement + + + align:start position:0% +the value of one event B complement +corresponds to the event that Y takes + + align:start position:0% +corresponds to the event that Y takes + + + align:start position:0% +corresponds to the event that Y takes +the value of zero by similar arguments B + + align:start position:0% +the value of zero by similar arguments B + + + align:start position:0% +the value of zero by similar arguments B +and a complement will be independent and + + align:start position:0% +and a complement will be independent and + + + align:start position:0% +and a complement will be independent and +we translate that into probability + + align:start position:0% +we translate that into probability + + + align:start position:0% +we translate that into probability +notation + + align:start position:0% + + + + align:start position:0% + +and then we translate this equality into + + align:start position:0% +and then we translate this equality into + + + align:start position:0% +and then we translate this equality into +PMF notation and we get this relation + + align:start position:0% +PMF notation and we get this relation + + + align:start position:0% +PMF notation and we get this relation +finally using the same property that we + + align:start position:0% +finally using the same property that we + + + align:start position:0% +finally using the same property that we +use to do the first step here we have + + align:start position:0% +use to do the first step here we have + + + align:start position:0% +use to do the first step here we have +that a compliment and B complement are + + align:start position:0% +that a compliment and B complement are + + + align:start position:0% +that a compliment and B complement are +also independent and by following the + + align:start position:0% +also independent and by following the + + + align:start position:0% +also independent and by following the +same line of reasoning this applies the + + align:start position:0% +same line of reasoning this applies the + + + align:start position:0% +same line of reasoning this applies the +fourth relation as well so we have + + align:start position:0% +fourth relation as well so we have + + + align:start position:0% +fourth relation as well so we have +verified that if events a and B are + + align:start position:0% +verified that if events a and B are + + + align:start position:0% +verified that if events a and B are +independent then we can argue that all + + align:start position:0% +independent then we can argue that all + + + align:start position:0% +independent then we can argue that all +of these four equations will be true and + + align:start position:0% +of these four equations will be true and + + + align:start position:0% +of these four equations will be true and +therefore random variables x and y will + + align:start position:0% +therefore random variables x and y will + + + align:start position:0% +therefore random variables x and y will +also be independent \ No newline at end of file diff --git a/Hz1S82W8F04.txt b/Hz1S82W8F04.txt new file mode 100644 index 0000000000000000000000000000000000000000..33d88785ecdafb50d108802b30997a8656770f29 --- /dev/null +++ b/Hz1S82W8F04.txt @@ -0,0 +1,4806 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high quality educational +resources for free. + +To make a donation or to view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +So for the course, we have +four days of lectures. + +Today we'll try to convince +you that it was actually a + +good idea to come here, why +randomized evaluation is such + +a useful tool and why it's +superior to many other kinds + +of impact evaluation. + +Once we've convinced you that +it's a good idea to come here, + +then we'll start going through +the nuts and bolts of actually + +how to run randomized +evaluations. + +Tomorrow we'll go over some +of the general design + +possibilities. + +The following day we'll go +into some more of the + +technical aspects like sample +size and measurement. + +The last day we'll kind of +discuss the fact that even in + +randomized evaluations, things +can go wrong, and how + +you deal with that. + +And throughout the entire course +as you're learning + +this, you'll be incorporating +what you learn by designing in + +step with the lectures your own +randomized evaluation in + +the groups that you've +been preassigned. + +So if you check out your name +tags, you'll see that you have + +a group number. + +Find other people with the +same color and number and + +those will be your +group members. + +We tried to put you together +in ways that made sense. + +So we tried to have people who +were interested in agriculture + +work with other people +within agriculture. + +And over the course of the four +days, you'll be designing + +your own randomized +evaluation. + +And on the last day, on +Saturday, you will be + +presenting your evaluation +to the entire group. + +So that is pretty much +what to expect over + +the next five days. + +Have I forgotten anything? + +Then let me reintroduce +Rachel who will start + +five minutes early. + +RACHEL GLENNERSTER: The group +the Mark was talking about is + +a really integral part +of the course. + +So unfortunately that is not +something that you'll be able + +to get online. + +But hopefully it's a chance for +you to go through, each + +time we present an idea in the +lecture, you then need to go + +and apply it in the case that +you're developing in your + +evaluation you're developing +in your group. + +And that's what all the teaching +assistants are here, + +to help you go through the +case studies, but also to + +develop your own evaluations. + +So I'm going to start with the +general question of what is an + +impact evaluation and when +should we do one. + +One of the objectives of this +lecture is just to make sure + +that we're all on the same page +when we start using terms + +like process evaluation +and impact evaluation. + +Because I realize the more I +spend time with people who are + +kind of professional evaluators, +I realize that + +economists and professional +evaluators use the same terms + +but to mean different things, +which is incredibly confusing. + +So I'm sure a lot of this will +be familiar to you, but on the + +other hand, we need to make sure +that every one is at the + +same level in using the terms in +the same way before we kind + +of head into the +nuts and bolts. + +But I also have incorporated in +this discussion about when + +you should do an impact +evaluation, which is something + +that comes up an awful lot +when I go and talk to + +organizations who are trying +to think through their + +evaluation strategy. + +They've heard that they ought +to be doing more impact + +evaluations. + +There's lots of focus on this. + +But they're expensive. + +So how do they decide which of +their programs to evaluate and + +at what stage to evaluate it. + +They're getting pressure +from donors to do this. + +But they're not quite sure +when it's appropriate. + +So we'll try and cover +those ideas. + +So we'll start with why is it +that we here at J-PAL are + +focused on impact evaluation. + +Because there's lots of other +things in evaluating our + +programs that are important. + +But we just do impact +evaluation. + +We also only do randomized +impact evaluation. + +And that's not to say that's +the only thing + +that's worth doing. + +We certainly don't think that. + +That's what we do. + +There's a reason we +do it, because + +we think it's important. + +But it's certainly not the only +thing that you should be + +doing in your organizations. + +So step back and look at the +objectives of evaluation and a + +model of change, which is very +important in terms of how to + +think about your evaluation, +how to design it, different + +types of evaluation, how +evaluation feeds into cost + +benefit analysis, and then +into why to do an impact + +evaluation, and putting +it all together into + +an evaluation strategy. + +And then coming back +to how do we learn. + +How do we make an organization +that learns from its + +evaluation strategy rather +than just doing this as + +something a funder wants +me to do or I have to + +do to tick a box. + +How do I develop an organization +that learns from + +its evaluations and makes it +a better organization? + +So this is the motivation +for what we do. + +And I think this point is sort +of the main point here. + +If you step back and you think +about how much evidence we + +have in development, to make the +decisions that we need to + +make, it's really quite +appalling how little + +information we have. + +If you think about some of the +biggest challenges in the + +world in development about how +to prevent the spread of + +HIV/AIDS in Sub-Saharan Africa, +how to improve the + +productivity of small farmers +across the world, it's really + +amazing how little really +rigorous evidence we have to + +make those decisions. + +And we may know that this +project may work or that + +project may work, but we very +rarely know what is the most + +cost-effective place to put +a dollar that I have. + +If I'm choosing in HIV +prevention, if I've got to + +choose between a lot of +different seemingly great + +projects, what is the project +that's going to give me the + +most bang for my buck? + +And we really don't have that +kind of consistent rigorous + +impact evaluation data in order +to make those decisions. + +And that was really the reason +why J-PAL was started, because + +of the feeling that we could +do so much better if we had + +that kind of data. + +And it's also too often the +case that decisions about + +development are based on emotion +rather than data. + +You can see this in proposals +that people write and the + +discussions that people have, +very compelling, personal + +stories, which are important, +but aren't really what we + +should be making all +our decisions on. + +That may be very motivating +to get people involved. + +But when you're talking about +trade-offs, you've got to have + +a lot more rigorous evidence. + +If we had that kind of evidence, +we could be a lot + +more effective with the +money that we have. + +I also think it's true, +sometimes people say oh, well + +you're just talking about +passing a dollar and spending + +it in a slightly more marginally +effective way. + +But what we really need +is more money going + +into poverty really. + +But arguably, potentially one of +the most important ways to + +get more money to go into +poverty relief is to convince + +people that the money that's +going in is actually used + +effectively. + +So I don't see these +as either/or. + +Using the money effectively +and raising more money, I + +think, both can come from +having more evidence. + +So it's also important, I think, +in a way, to move from + +what I think is a very damaging +and nonconstructive + +debate between the aid +optimists and the aid + +pessimists. + +It's a very kind of polarized +debate with Jeff Sachs on one + +side and Bill Easterly +on the other. + +This is a quote from Jeff Sachs: +"I've identified the + +specific investments +that are needed"-- + +from the previous sentence, +you know that + +this is to end poverty-- + +"found ways to plan and +implement them and show that + +they can be affordable." + +Now if you think we +know everything + +about development already-- + +we know what's needed, we know +how to implement it-- then, + +kind of, this is the wrong +course for you. + +But I think most of us would +agree that that's slightly + +overstating how much information +we have about how + +to end poverty. + +There's a lot more questions out +there than that suggests. + +His argument is, but we have +to get people motivated. + +So we have got to say that +we know everything. + +I don't think we have to be +quite that optimistic. + +On the other hand, I think this +is way too pessimistic. + +After $2.3 trillion over five +decades, why the desperate + +needs of the world's poor still +so tragically unmet? + +Isn't it finally time to end the +impunity of foreign aid? + +So Bill Easterly is kind of +saying, oh, it has not worked. + +So let's throw it all away. + +We've got to find a middle +ground here. + +It's just about time that +we have a development. + +And they're talking about aid. + +And I would argue it's +much more about + +development than aid. + +Aid is only a small fraction of +the money that's spent on + +reducing poverty in developing +countries. + +Development pessimism +is just as bad. + +We've got to think more +strategically about not just + +that all aid is bad or +development funding is wasted, + +but how do we focus the money +on the right things. + +So that's kind of +the motivation + +for what we're doing. + +But if you think on a very +grand scale, but thinking + +about the objective of +evaluation in general, you can + +think of it as three things. + +Accountability, did we do what +we say we were going to do? + +And again, this is true of aid +agencies, NGOs, government. + +And did we have a positive +impact on people's lives? + +So those are two different +aspects of accountability that + +evaluation needs to speak to. + +Evaluation isn't only about +accountability though. + +I think it's very importantly +about lesson learning so we do + +better in the future. + +And that's about does a +particular program work or + +not, and what's the most +effective route to achieve a + +certain outcome? + +Are there similarities? + +Are there lessons that you can +learn across projects? + +Are there similarities about +what we're finding in the + +evaluation of this project +and that project? + +For example, are there are +ways that you're learning + +about how to change people's +behavior in health, and + +agriculture, and education? + +Are there similarities, sort of +underlying principles, that + +we're learning about that we can +use in different contexts? + +And ultimately, to reduce +poverty through more effective + +programs is the ultimate +objective of evaluation. + +So using that as a framework, +what makes a good evaluation? + +Well, the key thing is +it's got to answer + +an important question. + +But it's no good if it answers +an important question but it + +answers it badly. + +It's got to answer it +in an unbiased way. + +What do I mean by that? + +I mean that it's got to +find the truthful + +answer to the question. + +And really to do that, you +need to have a model or a + +theory of change about how the +project is working so that you + +can test the different +steps in the model. + +And that's the best way to +then learn the most. + +If we simply say, we test +whether the project worked or + +didn't work, we learned +something, but we learn an + +awful lot more if you have a +specific model of how the + +project is going to work and you +test the different steps + +along the way. + +Sometimes people say-- + +this is something that drives +me mad in the evaluation + +literature-- + +you hear people saying, +well, randomized + +evaluations are a black box. + +They can tell you whether +something works or not, but + +they can't tell you why. + +I hope in the next few days, +we're going show to you how + +you design an evaluation that +tells you not just whether it + +works or not at the end, but +why and how, and the steps + +along the way, and design it +cleverly so that you learn as + +much as you possibly can from +the evaluation about the + +fundamental question. + +And that's about getting +the questions + +right at the beginning. + +And it's about doing your model +correctly and thinking + +of indicators along the way that +are going to allow you to + +get to all those steps and +really understand the theory + +of change that's happening. + +The model is going to start with +what is it we're trying + +to do, who are the targets, +and what are their needs. + +So in an evaluation in +development, this would often + +be called a needs assessment. + +And what are their needs? + +But then what's the program +seeking to change? + +And looking at precise and +individual bits of the + +program, what's the precise +program or part of the program + +that's being evaluation, +so asking + +very specific questions. + +So let's look at an example. + +And all of this we're going +to come back to + +and do in more detail. + +How do you do a logframe? + +Again, maybe some of you +have done that before. + +Maybe you haven't. + +But hopefully you'll learn more +about how we think about + +doing a logframe. + +So here's an example of an +evaluation that looked, a very + +simple one, does giving +textbooks to children in Kenya + +improve test scores was +the evaluation. + +But what was the need? + +What was the problem that the +program was trying to test? + +Well poor children in Busia +District in Kenya had low + +learning levels. + +They also had low incomes. + +They had few books. + +That meant that they couldn't +take the books home, and that, + +the theory was, made +it hard to learn. + +So it was hard to learn because +they didn't have a + +book in front of them in class, +but also because there + +were so few, they couldn't take +them home and read up + +more and do exercises at home. + +So what was the input? + +The input was that a local NGO +bought additional textbooks. + +In order to get to your +long-term goal, you not only + +need the books, you +need to make sure + +that they're delivered. + +Because, again, making this +chain along the way will help + +you understand if it doesn't +work, where did it go wrong, + +if the books were bought but +they never got there, or they + +were stuck in the cupboard. + +How many times have we been to +schools and oh, yes, we have + +lots of books. + +And we don't want them to get +messy when the children are + +using them. + +So they're all nicely in +their sealed package. + +Well you need to be able to +distinguish if something + +doesn't work, is it because it's +stuck in the cupboard? + +Or was it because even when the +books are out there they + +didn't get used or +they didn't help? + +So the books are delivered +and used. + +The children use the books and +they're able to study better. + +And finally, the impact, which +is what we're about here, is + +yes, you got all of +those steps done. + +But did it actually change +their lives? + +Did it actually achieve the +impact you are hoping to get + +is high test scores? + +The long-term goal would be not +just high test scores but + +higher income. + +And that long-term goal may be +very difficult to test in the + +evaluation. + +And you may use some other +work that may have linked + +these in previous studies in the +same country to make the + +assumption that if we got higher +test scores, it will + +have a positive impact. + +So again, that's a decision +when you make in your + +evaluation how far along this +chain you go, if it's a + +process evaluation you +may stop here. + +If it's an impact evaluation +you have to stop here. + +But you may not have enough +money to take it all the way + +through to the finest, finest +level that you would like to. + +Oh, I didn't do my little red +triangles at right point. + +OK. + +So I've already, in a +sense, introduced + +some of these concepts. + +But again, let's review them so +we know we're talking about + +the same thing. + +There are many different +kinds of evaluation. + +And needs assessment is where +you go in and look at a + +population, see what +are the issues. + +How many of them +have bed nets? + +What are test scores +at the moment? + +How many books are there? + +What's class size? + +What are the problems in +your target population? + +In our process evaluation, does +someone want to tell me + +what they would see as +a process evaluation? + +We talked a little +bit about it. + +Someone? + +Yeah. + +AUDIENCE: +[UNINTELLIGIBLE PHRASE] the + +chain that you just presented +to see how you get from the + +input to the output from the +output to the outcome of this + +RACHEL GLENNERSTER: Right. + +AUDIENCE: Are we successful in +doing that in transforming our + +input into output? + +RACHEL GLENNERSTER: Right. + +So process evaluation looks at +did we buy the textbooks? + +Were they delivered? + +Were they used? + +So moving inputs, outputs, +outcomes, but stopping short + +before we get to the impact. + +And that's a very useful thing +to do, and should be done + +basically everywhere you do a +program, or at least some of + +those steps need to be measured +almost every time you + +do a program. + +But it kind of stops short +before you get + +to the impact stage. + +Have we actually changed +people's lives? + +We wanted to build a school. + +Did we build a school? + +We wanted to build a bridge. + +Did we build a bridge? + +We wanted to deliver things? + +Did we deliver things? + +But it's stopping before you +get the point of knowing + +whether this has actually +changed people's lives. + +So an impact evaluation then +goes to the next stage and + +says, given that we have done +what we said we're going to + +do, has that actually +changed things? + +And this is where there +was a big gap in + +terms of what we know. + +There's a lot of +lesson learning + +you can do from process. + +But in terms of knowing what +kind of project is going to be + +successful in reducing poverty, +you really need to go + +this next step. + +Now we used to just talk +about those three. + +But increasingly, as I say as +I have more contact outside + +economics and the more research +side of evaluation to + +work a lot with DFID and other +organizations, other + +foundations, and other agencies, +I realize a lot of + +what people outside the academic +community call + +evaluation I would +call review. + +It's very weird. + +Because they would often call +what I call something else. + +But what I mean by review is, +it's sort of an assessment. + +It's sending a knowledgeable +person in and reviewing the + +program and giving their +comments on it, which can be + +extremely helpful if you have +a good person going and + +talking to the people involved, +and saying, well, in + +my experience, it could have +been done differently. + +But it doesn't quite actually +do any of these things. + +It's not just focused in +did I build the school. + +But it's asking questions +about was there enough + +participation. + +How well organized +was the NGO? + +And a lot of this is +very subjective. + +So I'm not saying that +this is bad. + +It's just kind of different. + +And if you have someone +very good doing it, + +it can be very useful. + +My concern with it, is that it's +very subjective to the + +person who's going. + +Yeah. + +Logan? + +AUDIENCE: I think that you see +so many reviews simply because + +the way-- you just +mentioned DFID. + +USAID, I think, is +the same way. + +It's all retroactive. + +The way that contracts are +awarded and things like that, + +usually it's because it's a +requirement to evaluate a + +certain number of programs. + +And it's not until after the +program is actually done that + +they decide they're going +to evaluate it. + +And it's obviously cheaper to +send one person over and do + +the simple review. + +I think it would +be interesting. + +We'll probably get to this when +we talk about how you can + +apply some of the randomized +control test methodology to + +something that you're +doing retroactively. + +RACHEL GLENNERSTER: So just to +repeat, the argument is we do + +a lot of reviews because a +lot of evaluation is done + +retroactively. + +What you can do at that +point is very limited. + +Yes. + +So this is a big distinction +between the kinds of + +evaluations, is one that's set +up beforehand and one that is + +after the event. + +We've got this program. + +We want to know whether +it works. + +Basically it's really +hard to do that. + +You've already kind of shot +yourself in the foot if you + +haven't set it up beforehand. + +If we think about what I was +saying about it's crucial to + +have a theory of change, a model +about what we're trying + +to achieve and how we're going +to try and achieve it, and + +measuring each of those steps, +if you're coming in + +afterwards, then you're kind +of adhoc-ly making up what + +your theory of change is. + +And you haven't set up systems +to measure those steps along + +the way, it's going to +be very hard to do. + +And that's exactly why you end +up with a lot of reviews. + +You're in this mess. + +And so you just send someone +knowledgeable and hope they + +can figure it out. + +To answer your specific question +though, you can't do + +a randomized evaluation +after the event. + +Because the whole point is +you're moving people into + +treatment and control based +on a flip of the coin. + +And then after the event, people +have been allocated to + +the treatment or not +the treatment. + +And it's very difficult to know +afterwards were these + +people similar beforehand. + +It's impossible to +distinguish. + +They may look different now. + +But you don't know whether +they look different now + +because they were different in +the beginning or because + +they're different because +of the program. + +Yeah? + +AUDIENCE: I was really +interested to read the first + +case study because it seemed +that you were applying + +randomized control +methodology. + +But it seemed to be actually +done retroactively. + +RACHEL GLENNERSTER: No. + +It wasn't. + +It might look that way. + +But it was set up so the first +case study uses a lot of + +different methodologies, +compares different + +methodologies. + +But they couldn't use all those +methodologies if they + +hadn't designed it as a +randomized study at the + +beginning actually. + +If you've set up a randomized +evaluation, you can always do + +a non-randomized evaluation +of it. + +But if you haven't done it as +a randomized to start with, + +you can't make it randomized. + +Prospective evaluation, setting +up the evaluation from + +the beginning, is very important +I would say in any + +methodology you use. + +But it's impossible to do it. + +There are a couple of examples +where people have done a + +randomized evaluation afterwards +or an evaluation + +afterwards. + +And that is because the +randomization happened + +beforehand. + +But it wasn't done because +it was an evaluation. + +So if you look at the case on +the women's empowerment in + +India, you will do later in the +week, that was not set up + +as an evaluation. + +It was set up as a randomized +program. + +And the rationale was they +wanted to be fair. + +So where there's limited +resources, sometimes + +governments are the people who +randomized in order to be fair + +to the different participants. + +Some people, in this +case, will have to + +get a women's leader. + +In Colombia Project, that you'll +find on our website, + +the Colombian government wanted +to provide vouchers to + +go to private school. + +But they couldn't afford +it for every one. + +So they randomized who +would get them. + +So that's the one case where +you can do a randomized + +evaluation after the event, +when somebody else is + +randomized beforehand, but they +weren't actually thinking + +of it as an evaluation. + +But even then, it would've +been nice to have data + +beforehand. + +So the last thing on this list +is cost-benefit analysis, + +which is something that you can +do with the input from all + +of these other things. + +As they say, the piece of +information that we have so + +little of is what's the effect +of a dollar here versus a + +dollar here. + +And you can only do that if +that's one of your ultimate + +objectives when you're doing +these other impact evaluations + +or these other evaluation +methodologies. + +Because you need to be +collecting data about costs. + +And the benefits will come from +your impact evaluation. + +But you need to get your costs +from your process evaluation. + +And you can put the +two together. + +And you can do a cost +effectiveness. + +Then if somebody else has done +that in their other study, you + +can do a cost effectiveness +comparison across studies. + +Or even you can evaluate a range +of different options on + +your impact evaluation. + +And that will give +you comparative + +cost-effectiveness across. + +So going into a bit more detail +in some of these, needs + +assessment. + +We'll look at who's the +target population. + +Is it all children or are we +particularly focused on + +helping the lowest-achieving +in the group? + +What's the nature of the +problem being solved? + +Many of these communities will +have lots of problems. + +So what are we particularly +trying to focus on here? + +Is a test schools? + +Is it attendance at school? + +How will textbooks solve +the problem? + +I was talking about textbooks. + +Maybe it's because they +can take them home. + +Well, if that's part of your +model, your theory of change, + +you need to be actually +measuring that, not just did + +they arrive. + +How does the service fit +into the environment? + +How many times have we sat +in an office and designed + +something that we thought made +complete sense, and gone out + +to the field and thought, +what was I thinking? + +This isn't going to work. + +How does it feel for +the teachers? + +Do they understand +the new books? + +Do they know how to +teach from them? + +How do the books fit +into the curricula? + +What are you trying to +get out of this? + +As they say, you want a clear +sense of the target + +population. + +So then you want to see are +the students responding? + +If you're particularly worried +about low-performing kids, are + +they responding to +the textbooks? + +Students who are falling behind, +a sense of the needs + +the program will fill, what +are the teachers lacking? + +How are we going to deliver +the textbooks? + +How many textbooks are +we going to deliver? + +And what are the potential +barriers for people learning + +from the textbooks? + +Then a clear articulation of +the program benefits, and a + +sense of alternatives. + +And as I say, if you want to +look at cost-effectiveness of + +alternative approaches, it's +very important to think + +through not just this program in +isolation, but what are the + +alternatives that we +could be doing? + +And how does that +fit with them? + +Is this one is the most +expensive things we're going + +to try, one of the cheapest +things we want to try, and + +everything in between? + +So you may be thinking in this +context, is this a replicable + +program that I'm going to +be able to do elsewhere? + +Is this the gold-plated version +that I'll do if I get + +lots of funding? + +Or is this something that +I can replicate in + +lots of other places? + +Process evaluation, I've really +sort of talked quite a + +bit about these. + +So I'm going through +them faster. + +And when you do an impact +evaluation, because the impact + +evaluation is the last thing on +that chain, you need to do + +all the other bits on +the chain as well. + +You can't do an impact +evaluation without a process + +evaluation or you won't +understand what the hell your + +answer is meaning at the end. + +So as we say, a process +evaluation is asking are the + +services being delivered? + +Is the money being spent? + +Are the textbooks reaching +the classroom? + +Are they being used? + +And it's also, as I say, +important to be asking + +yourself, what are +the alternatives. + +Could you do this +in a better way? + +Just like a company is always +thinking are there ways to + +reduce costs. + +You should be thinking +are their ways to + +do this more cheaply. + +Are the services reaching +the right populations? + +Which students are +taking them home? + +Is it the ones that I'm +targeting or only the most + +motivated ones? + +And also, are the clients +satisfied? + +What's their response +to the program? + +So an impact evaluation, am +i missing a top bit here? + +No. + +OK. + +Here we go. + +We're out of order. + +So an impact evaluation +is, as they say, + +taking it from there. + +So assuming once you've got all +the processes working, and + +it's all happening, but +if it happens, does + +it produce an impact? + +Take our theory of +change seriously. + +And say what we might expect +to change if that theory of + +change is happening. + +So we've got this theory of +change that says, this is how + +we expect things to change. + +These are the processes by which +we expect, like the kids + +taking the books home. + +So we want to design some +intermediate indicators and + +final outcomes that will +trace out that model. + +So our primary focus is going to +be, did the textbooks cause + +children to learn more. + +But we might also be +interested in some + +distributional issues. + +Not just on average, we might +also be interested in was it + +the high achieving kids +that learned more? + +Was it the low-achieving kids? + +Because very often in +development, we're just as + +interested in the distributional +implications of + +a project as the average. + +So who is it who learned? + +How does impact differ +from process? + +In the process, we describe +what happened. + +And you can do that from +reading documents, + +interviewing people in +administrative records. + +In an impact question, we need +to compare what happened to + +the people who got the program +with what would have happened. + +This is the fundamental question +that Dan is going to + +hammer on about in his lecture +about why do we use randomized + +evaluations. + +We talk about this is +the counterfactual. + +What would have happened if the +program hadn't happened? + +That's the fundamental +question that we're + +trying to get at. + +Obviously it's impossible to +know exactly what would have + +happened if the program +hadn't happened. + +But that's what we're +trying to get at. + +Just one second. + +Yeah? + +AUDIENCE: So one thing that +would seem to fit in somewhere + +with the impact thing but +doesn't quite meet the + +criteria that you've just +described that we've use + +sometimes is this +pre-post test. + +And that isn't necessarily +going to say + +what would have happened. + +But it will say, well, +what were the + +conditions when you started? + +And we extrapolate from that +looking at where we are when + +we ended, what can we say +about the impact of the + +intervention? + +RACHEL GLENNERSTER: Right. + +So that is one way that people +often try and do an impact + +evaluation and measure are +they having an impact. + +And I guess it can give you some +sense of whether you're + +having an impact or +flag problems. + +It's to say, well, what were +conditions at the beginning? + +What are they like now? + +Then you have this assumption, +which is that all the + +difference between then and +now is due to the program. + +And often that's not a very +appropriate assumption. + +Often things happen. + +If we take our example of +schools, the kids will know + +more at the end of +the year then + +they knew at the beginning. + +Well would they have known more +even if we hadn't given + +them more textbooks. + +Probably. + +So that's kind of +the fundamental + +assumption you're making. + +And it's a difficult +one to make. + +It's also the case that we +talked to people who were + +doing a project in Gujarat. + +And they were tearing their hair +out and saying, well, we + +seem to be doing terribly. + +Our program is doing terribly. + +People now are worse off +than when we started. + +This was, well Mark will know +the years of the riots and + +earthquake in Gujarat. + +They'd basically taken data +when they started. + +In the meantime, there had been +a massive earthquake and + +massive ethnic riots against +Muslims in Gujarat. + +Of course people +were worse off. + +And that's not because of you. + +So if can go either +way actually. + +You can assume that your program +is doing much better + +because other things are coming + +along and helping people. + +And you're attributing all the +change to your program. + +Or it could be the case in +this extreme example. + +There's a massive earthquake +and massive religious and + +ethnic riots and you +attribute all the + +negative to your program. + +So it's a way that sometimes +people use of + +trying to get an impact. + +It's not a very accurate way of +getting your impact, which + +is why a randomized evaluation +would help. + +So, as you say, it doesn't +quite fit this criteria. + +Because it doesn't +quite answer. + +It says what happened +over the period. + +It doesn't say what would +have happened. + +It is not a comparison of what +would have happened with what + +actually had. + +And that's how you want +to get at your impact. + +So there are various +ways to get at it. + +But some of them are more +effective than others. + +So let's go back to our +objectives and see if we get a + +match these different kinds of +evaluations to our different + +objectives for evaluation and +find out which evaluation will + +answer which question. + +So accountability: the first +question for accountability is + +just did we do what we said +we were going to do. + +Now that you can use a process +evaluation to do that. + +Because did I do what I said +I was going to do. + +I promised to deliver books. + +Did I actually deliver books? + +Process evaluation is fine +for that kind of level of + +accountability. + +If my accountability is not just +did I do what I said, but + +did what I do help? + +Ultimately I'm there +to help people. + +Am I actually helping people? + +That's a deeper level +of accountability. + +And that, you can only answer +with an impact evaluation. + +Did I actually make the change +that I wanted to happen? + +If we look at lesson learning, +the first kind of lesson + +learning is, does a particular +program work or not work. + +So an impact evaluation can tell +you whether a particular + +program worked. + +If you look at different +impact evaluations of + +different programs, you can +start saying which ones + +worked, whether they work in +different situations, or + +whether a particular kind of +program works in different + +situations or not. + +Now what is the most effective +route for achieving a certain + +outcome is kind of an even +deeper level of learning. + +What kind of thing is the best +thing to do in this situation? + +And there you want to have +a cost-benefit analysis + +comparing several programs based +on a number of different + +impact evaluations. + +And then we said an even +deeper level is, can I + +understand how we +change behavior? + +Understand deep parameters of +what makes a successful + +program, of how do we change +behavior from health to + +agriculture? + +What are some similarities and +understanding of how people + +tick, and how we can use that +to design better programs? + +And again, that's linking our +results back to theories. + +You have got to have a deeper +theory understanding it, and + +then test that with different +impact evaluations. + +And you can get some kind of +general lessons from looking + +across impact evaluations. + +And then if we want to have our +reduced poverty through + +more effective programs, which +is our ultimate objective of + +doing evaluations, we've got to +say, did we learn from our + +impact evaluations? + +Because if we don't learn from +them and change our programs + +as a result, then we're not +going to achieve that. + +And I guess to say that solid, +reliable impact evaluations + +are a building block. + +You're not going to get +everything out of one impact + +evaluation. + +But if you build up enough, you +can generate the general + +lessons that you need +to do that. + +I've said quite a lot +of this already. + +But needs assessments give you +the metric for defining the + +cost-benefit ratio. + +So when we're looking at +cost-benefit analysis, we're + +looking at what's the most +cost-effective way of + +achieving x? + +Well, you need a needs +assessment to + +say what's the x? + +What's the thing that I should +be really trying to solve? + +Process evaluation gives you the +costs for your inputs to + +do a cost-benefit analysis. + +And an impact evaluation +tells you the benefit. + +So all of these different inputs +and needed to be able + +to do an effective cost-benefit +analysis. + +AUDIENCE: Rachel? + +RACHEL GLENNERSTER: Yeah? + +AUDIENCE: The needs assessment +seems to be more of a program + +design sort of a +[UNINTELLIGIBLE], whereas the + +remaining three are more like +the program has already been + +designed and we are being +cautious, we have thought that + +this is the right program +to go with. + +Please design a process +evaluation for this or a + +program evaluation for this. + +How has that needs assessment +different from the one that + +feeds into program design? + +RACHEL GLENNERSTER: Well, in a +sense, there's two different + +concepts here. + +You're right. + +There's a needs assessment +for a particular project. + +We're working with an NGO in +India called [UNINTELLIGIBLE] + +working in rural Rajasthan. + +And they said, we want to +do more on health in our + +communities. + +We've done a lot of education +and community building. + +But we want to do a lot +more in health. + +But before we start, we want +to know what are the health + +problems in this community? + +It doesn't make sense +to design the + +project until you know. + +So we went in and did., what +are the health problems? + +What's the level of services? + +Who are they getting +their health from? + +We did a very comprehensive +analysis of the issues. + +And that was a needs assessment +for that particular + +NGO in that particular area. + +But you can kind of think of +that in a wider context of + +saying, what are the key +problems in health in India or + +in developing countries? + +What are the top priority +things that we should be + +focusing on? + +Because again-- + +and I'm going to get on to +strategy in a minute-- if + +you're thinking as an +organization, you can't do an + +impact evaluation +for everything. + +You can't look at comparative +cost-effectiveness for + +outcomes in the world. + +Or at least you've got +to start somewhere. + +You've got to start on, what +do I most want to know? + +What's the main thing I want +to change to see what's the + +cost of changing that thing? + +So is it test scores +in schools? + +Or is it attendance? + +Am I most concerned about +improving attendance? + +If you look at the Millennium +Development Goals, in the + +sense, that's the world's +prioritizing. + +They're saying, these are the +things that I most want to + +change in the world. + +And there they made the +decision, rightly or wrongly, + +on education, that they wanted +to get kids in school. + +And there isn't anything about +actually learning. + +And whether your needs is +getting kids in school or + +learning, you would design +very different projects. + +But you would also design +different impact evaluations, + +because those are two very +different questions. + +So the needs assessment +is telling you + +what are the problems? + +What am I prioritizing for my +programs, but also for my + +impact evaluations? + +Yeah? + +AUDIENCE: Do you need to make +a decision early on whether + +you're interested in actually +doing a cost-effectiveness + +analysis as opposed +to a cost-benefit. + +RACHEL GLENNERSTER: +[INTERPOSING VOICE] + +AUDIENCE: +[UNINTELLIGIBLE PHRASE]. + +efficiency measure, where as +cost [UNINTELLIGIBLE}-- + +RACHEL GLENNERSTER: So I'm kind +of using those too easily + +interchangeably. + +I don't think it's so +important here. + +How would you define the +difference between them? + +AUDIENCE: As I understand it, +but [UNINTELLIGIBLE PHRASE] + +they getting a better answer. + +But cost-effectiveness is +a productivity measure. + +And it would mean that you +would have to, in an + +evaluation say, OK, I'm going to +look at I put one buck into + +this program and I get +how many more days of + +schooling out of it. + +Right? + +RACHEL GLENNERSTER: Right. + +AUDIENCE: Whereas cost-benefit +requires that it all be in + +dollars or some other +[UNINTELLIGIBLE]. + +RACHEL GLENNERSTER: So you've +got to change your benefit + +into dollars. + +So I'll give you an example +of the difference. + +AUDIENCE: Like +[INAUDIBLE PHRASE]. + +RACHEL GLENNERSTER: Let's make +sure everybody's following + +this discussion. + +A cost-effectiveness question +would be to say, I want to + +increase the number +of kids in school. + +How much would it cost to get +an additional year of + +schooling from all of these +different programs? + +And I'm just assuming that +getting kids in school is a + +good thing to do. + +Right? + +I want to do it. + +So I'm asking what's the cost +per additional year of + +schooling from conditional cash +transfer, from making it + +cheaper to go to school by +giving free school uniforms, + +or providing school meals. + +There are many different things +I could that will + +encourage children to +come to school. + +But I know I want children +to come to school. + +I'm not questioning that goal. + +So I just want to +know the cost of + +getting a child in school. + +Cost-benefit kind of +squishes is it all. + +And it really asks the question, +is it worth getting + +kids in school? + +Because then you can say, if I +get kids in school, they will + +earn more and that will +generate income. + +So if I put a dollar in, am +I going to get more than a + +dollar out at the end? + +I'm not going to flick all +the way back to it. + +But if you remember that chart +that went through the process + +and impact, and then the final +thing of high test scores was + +higher income, ultimately am I +getting more money out of it + +than I'm putting in? + +I think that's sort of a +philosophical decision for the + +organization to make. + +It's very convincing to be able +to say, for every dollar + +we put in, I think for the +deworming case that you've got + +and you do later in the +week, they do both, + +cost-effectiveness +and cost-benefit. + +And the cost-effectiveness +says, this is the most + +cost-effective way to get +children in school. + +But they also then go further +and say, assuming that these + +studies that look at children in +school in Kenya earn higher + +incomes are correct, then given +how much it costs to get + +an additional year of schooling, +and given an + +assumption about how much extra +kids will in the future + +because they went to school, +then for every dollar we put + +in, I think it's you +get $30 back. + +So you kind of have to make an +awful lot more assumptions. + +You have to go to that +final thing and put + +everything on income. + +Now if I was doing the women's +empowerment study, then I'm + +not sure that I would want +to reduce women's + +empowerment to dollars. + +I might just care about it. + +I might care that women are more +empowered whether or not + +it actually leads to +higher incomes. + +So it kind of depends on the +argument that you're making. + +If you want to try and make a +this is really worth it, this + +is a great program, not just +because it's more effective + +than another program, but that +it generates more income then + +I'm putting in. + +That's a great motivation. + +But I wouldn't say you always +have to reduce it to dollars. + +Because you have to make an +awful lot of assumptions. + +And we don't necessarily +always want to reduce + +everything to dollars. + +So here it is. + +We've just been talking +about it. + +So this is a cost-effectiveness. + +So this is the cost per +additional year + +of schooling induced. + +We're not linking it back to +dollars we're measuring. + +We're just assuming that +we want kids in school. + +Millennium Development Goals +have it as a goal. + +we just think it's a good +thing, whether or not it + +generates income. + +What we did is take all the +randomized impact evaluations + +that had as an outcome getting +more children in school and + +calculated the cost per +additional year of schooling + +the resulted. + +So you see a very wide range +of different things. + +Now conditional cash transfers +turn out to be by far the most + +expensive way of getting an +additional year of schooling. + +Now that's partly because mainly +they're done in Latin + +America where enrollment rates +are already very high. + +So it's often more expensive to +get the last kid in school + +than the 50th percentile +kid in school. + +And then the other thing, of +course, in general, things + +cost more in Mexico than in +Kenya, especially when you're + +talking about people. + +Teacher's wages or +wages outside of + +school are more expensive. + +But the thing that was amazing +was that providing children + +with deworming tablets +was just unbelievably + +cost-effective. + +So $3.50 for an additional year +of schooling induced. + +And putting it this way I think +really brought out that + +difference. + +The other thing I should say +in comparing this is, there + +were other benefits +to these programs. + +So Progresa actually gave +people cash as well. + +So it wasn't just about getting +kids in school. + +So of course it was +expensive, right? + +And we haven't calculated +in those costs. + +In cost-benefit, if we reduced +everything to dollars, it + +would look very different +because you've got a value of + +all these other benefits. + +But again, deworming +had other benefits. + +It had health benefits as well +as education benefits. + +So we're just looking at one +measure of outcomes here. + +AUDIENCE: Excuse me. + +RACHEL GLENNERSTER: Yeah? + +AUDIENCE: Are these being +adjusted for Purchasing Power + +Parity, PPP? + +RACHEL GLENNERSTER: So +this is not PPP. + +This is absolute. + +So again, we've sort +of debated it + +backwards and forwards. + +So if you're a country, you +care more about PPP. + +But if you're a donor and you're +wondering whether to + +send a dollar or a pound to +Mexico or Kenya, you don't + +care about PPP. + +You care about where your dollar +is going to get most + +kids in school. + +So there's different ways +of thinking about it. + +It sort of depends on the +question you're asking and + +who's the person. + +For a donor, I think this +is the relevant way. + +If you're a donor who only cares +about getting kids in + +school, this is what +you care about. + +We also can redo this taking +out the transfers. + +There's this other benefit, +the families, + +of getting the money. + +So this is the cost +to a donor. + +So that's one way of +presenting it. + +But you can present it +in other ways too. + +AUDIENCE: Can you also sometimes +do a cost-benefit of + +the evaluation itself? + +RACHEL GLENNERSTER: That's kind +of hard to do because the + +benefits may come +ten years later. + +The way to think about that is +to think about who's going to + +use it, and only do it if you +think it's going to actually + +have some benefits in terms of +being used and not just maybe + +within the organization. + +But if it's expensive, +is it going to be + +useful for other people? + +Is it answering a general +question that lots of people + +will find useful? + +So often evaluations are +expensive in the context of a + +particular program. + +But they're answering a question +the lots of other + +people will benefit from. + +So the Progresa evaluation has +spurred not just the expansion + +of Progresa in Mexico, but it +has spurred it in many other + +countries as well because it +did prove very effective. + +Although it's slightly less +cost-effective in these terms. + +But it led to an awful +lot of learning in + +many, many other countries. + +So, I think, in that sense, it +was an extremely effective + +program evaluation. + +AUDIENCE: Excuse me, I just have +a question on that very + +last item there. + +RACHEL GLENNERSTER: OK, so this +one is even cheaper and + +it's a relatively new result. + +But it only works in certain +circumstances. + +When people don't know the +benefits of staying on in + +school, ie., how much higher +wages they're going to get if + +they have a primary education, +then telling them that + +information is very cheap. + +And both in the Dominican +Republic and Madagascar-- + +so two completely different +contexts, different rates of + +staying on in school, different +continents, very + +different schooling systems-- + +in both cases it was extremely +effective at increasing the + +number of kids staying +on in school. + +But that only works if people +are underestimating the + +returns of staying +on in school. + +If they're overestimating them, +then it would reduce + +staying on in school or if they +know already, then it's + +not going to be effective. + +So this is something that I +think is a very interesting + +thing ti do, and again, +is worth doing. + +But you need to first go in and +test whether people know + +what the benefits of staying +on in school are. + +Basically they just told them +what's the wage if you + +complete primary education +versus what's the wage if you + +don't complete primary +education. + +It's very cheap. + +So if it changes anything, it's +incredibly effective. + +AUDIENCE: Is the issue of +marginal returns a problem? + +Do you have to say that every +program is only relevant to + +places where it's +at same level of + +enrollment or admission? + +RACHEL GLENNERSTER: Well this is +a sort of wider question of + +external validity. + +When we do a randomized +evaluation, we look at what's + +the impact of a project +in that situation. + +Now at least you know whether +it worked in that situation, + +which is better than not really +knowing whether it + +worked in that situation. + +Then you've got to make a +decision about whether you + +think that is useful to +another situation. + +A great way of doing that is +to test it in a couple of + +different places. + +So again, this was tested in two +very different situations. + +The deworming had very +similar effects. + +In rural primary schools in +Kenya, it works through + +reducing anemia. + +Reducing anemia in preschool +urban India had almost + +identical effects. + +Getting rid of worms in a +non-randomized evaluation to + +be true, but kind of a really +nicely designed one in the + +south of the United +States had almost + +exactly the same effect. + +So they got rid of hookworm +in the 1900s. + +And again, it would increase +school attendance, increase + +test scores, and actually +increase wages just from + +getting rid of hookworm. + +And they reckoned a quite +substantial percentage. + +This paper by Hoyt Bleakley at +Chicago found that quite a + +substantial difference in the +income of the North and the + +South of United States in 1900 +was simply due to hookworm. + +So this is being tested. + +So ideally you test something +in very different + +environments. + +But you also think about whether +it makes sense that it + +replicates. + +So if I take the findings of the +women's empowerment study + +in India where it works through +local governance + +bodies that are quite active in +India and have quite a lot + +of power, and tried to replicate +in Bangladesh where + +there is no equivalent system, +I would worry about it. + +Whereas worms cause anemia +around the world. + +And anemia causes +you to be tired. + +And being tired is likely to +affect you going to school. + +That's something that seems +like it would replicate. + +So you have to think through +these things and + +ideally test them. + +If I'm doing microfinance, +would I assume it has + +identical effects in Africa, or +Asia, and Latin American? + +No. + +Because it's very dependent +on what are the learning + +opportunities in those +environments. + +And they're likely to +be very different. + +So I'd want to test it in those +different environments. + +We're falling a bit behind. + +So I promised to do when to +do an impact evaluation. + +So there are important +questions you need to + +know the answer to. + +So that might be because there's +a program that you do + +in lots of places, and you have +no idea whether it works. + +That would be a reason +to do one. + +You're very uncertain about +which strategy to + +use to solve a problem. + +Or there are key questions that +underline a lot of your + +programs, for example, adding +beneficiary control, having + +some participatory element +to your program. + +It might be something that you +do in lots of different + +programs when you don't know +what's the best way to do it + +or whether it's being +effective. + +An opportunity to do it is when +you're rolling out a big + +new program. + +And you're going to invest an +awful lot of money in this + +program, you want to know +whether it works. + +This is a tricky one. + +You're developing a new +program and you + +want to scale it up. + +At what point in that process +should you do the impact + +evaluation? + +Well you don't want to do it +once you've scaled it up for + +everywhere. + +Because then you find out it +doesn't work, and you've just + +spend millions of dollars +scaling it up. + +Well that's not a good idea. + +On the other hand, you don't +want to do it when it's your + +very first designs. + +Because often it changes an +awful lot in the first couple + +of years as your tweaking it, +and developing it, and + +understanding how to make +it work on the ground. + +So you want to wait until you've +got the basic kinks + +ironed out. + +But you want to do it before +you scale it up too far. + +We've done a lot of work +with this NGO in + +India called Pratham. + +And we started doing +some work for them. + +And by the time we finished +doing an evaluation, their + +program had completely +changed. + +So we kind of did another one. + +So we probably did that one +a little bit too early. + +But on the other hand, now +they're scaling up massively. + +And it would be silly to wait +until they'd done the whole of + +India before we evaluated it. + +AUDIENCE: You said it may be +more appropriate to do a + +process evaluation initially to +get a program to the point + +where it can be fully +implemented and all the kinks + +are worked out. + +RACHEL GLENNERSTER: +Yeah, exactly. + +If we're going back to our +textbook example again, you + +don't want to be doing it until +you've got your delivery + +system for the textbooks worked +out, and you've made + +sure you've got the +right textbook. + +It's a bit of a waste of money +until you've got those things. + +And exactly, a process +evaluation can tell you + +whether you've got those +things working. + +The other thing that makes it a +good time or a good program + +to do an impact evaluation of +is one that's representative + +and not gold-plated. + +Because if Millennium +Development Villages, $1 + +million per village. + +If we find that that has an +impact on people's lives, + +that's great. + +But what do we do with that? + +We can't give $1 million to +every village in Africa. + +So it's not quite, +what's the point? + +But it's less useful than +testing something that you + +could replicate across the whole +of Africa, that you have + +enough money to replicate +in a big scale. + +So that's interesting because +you can use it more. + +Because if you throw everything +at a community, + +yes, you can probably +change things. + +But what are you learning +from it? + +So it takes time, and +expertise, and + +money to do it right. + +So it's very important to think +about when you're going + +to do it and designing the right +evaluation to answer the + +right question that you're +going to learn from. + +AUDIENCE: If a program hasn't +been successful, have you + +found that the NGO's have +abandoned that program? + +RACHEL GLENNERSTER: +Yes, mainly. + +We worked with an NGO in +Kenya that didn't work. + +They just moved on to +something else. + +Pratham, we actually did two +things, both of which worked, + +but one which was more +cost-effective than the other. + +And they dumped the computer +assisted learning even though + +it was like phenomenally +successful. + +But the other one was +even cheaper. + +So they really scaled that up. + +And they haven't really done +computer assisted learning + +even though it had a very big +effect on math test scores. + +And compared to anybody else +doing education, it was very + +cost-effective But compared to +their other approach, which + +was even more cost-effective, +they were like, OK. + +We'll do the one that's +most cost-effective. + +Now there are some organizations +that + +kind of do one thing. + +And it's much harder for them +to stop doing that one thing + +if you find it doesn't work. + +They tend to think, well, +how can I adapt it? + +But these organizations that do +many things are often very + +happy to, OK, that +didn't work. + +We'll go this direction. + +So we want to develop an +evaluation strategy to help us + +prioritize what evaluations +to do when. + +So the first thing to do is step +back and ask, what are + +the key questions for +your organization? + +What are the things that I +really, really need to know? + +What are the things that would +make me be more successful, + +that I'm spending lots of money +on but I don't know the + +answer, or some of these more +fundamental questions, as they + +say, about how do I get +beneficiary control across my + +different programs. + +The other key thing is you're +not going to be able to answer + +all of them by your own +impact evaluations. + +And as they say, it's expensive +to do them. + +So the first thing to do is to +go out and see if somebody + +else has done a really good +impact evaluation that's + +relevant to you to answer +your questions already. + +Or half answer or more gives you +the hypotheses to look at. + +How many can I answer just +from improved process? + +Because if my problems are about +logistics, and getting + +things to people, and getting +cooperation from people, then + +I can get that from process +evaluation. + +So from that you can select your +top priority questions + +for an impact evaluation +and establish a plan + +for answering them. + +So then you've go to look for +opportunities where you can + +develop an impact evaluation +that will enable you to answer + +those questions. + +So am I rolling out a new +program in a new area? + +And I can do an impact +evaluation there. + +Or you might even want to +say, I want to set up an + +experimental site. + +I don't really know whether to +go this way or that way. + +So I'm just going to +take a place and + +try different things. + +And it's not going to be really +part of my general + +rollout But I'm going to focus +in on the questions. + +Should I be charging +for this or not? + +How much should I charge? + +Or how should I present +this to people? + +And you can take a site and +kind of try a bunch of + +different things against each +other, figure out your design, + +really hone it down, and +then roll that out. + +So those are two kinds of +different options of thinking + +about how to do it. + +And then, when you've got those +key questions of your + +impact, you can combine that +with process evaluations to + +get your global impact. + +What do I mean by that? + +Let's go back to our +textbook example. + +If you're giving out textbooks +across many states or + +throughout the country, +you've evaluated it + +carefully in one region. + +And you find that the impact +on test scores + +is whatever it is. + +And then you know very +carefully, and maybe you've + +tested it in two different +locations in the country and + +you've got very similar +results. + +So then you can say, well I know +that every time I give a + +textbook, I get this impact +on test schools. + +Then from the process +evaluation, you know how many + +textbooks are getting in +the hands of kids. + +Then you can combine the two, +multiply up your impact + +numbers by the number of +textbooks you give out. + +Malaria control with bed nets, +if I hand out this many bed + +nets, then I'm saving +this many lives. + +I've done that through a careful +impact evaluation. + +And then all I need to do is +just count the number of bed + +nets that are getting +to people and I + +know my overall impact. + +So that's a way that you +can combine the two. + +You don't have to do an impact +evaluation for every single + +bed net you hand out. + +Because you've really got the +underlying evaluation impact + +model, and you can +extrapolate. + +AUDIENCE: Rachel? + +RACHEL GLENNERSTER: Yeah? + +AUDIENCE: Do you think in the +beginning when you got a + +program that you're interested +in, do you think that's the + +moment to think about the size +of the impact that you're + +looking at that people expect? + +And also, as part of that, +what's going to be the + +audience, the ultimate audience +that you're trying to + +get to if you're successful +with a scale-up. + +And those two things, I think, +frequently come together. + +Because it's the scaling up +process where people are going + +to start to look at those +cost-effectiveness measures + +and cost-benefit. + +RACHEL GLENNERSTER: I mean, I +would argue that you've always + +got to be thinking about your +ultimate plans for scaling it + +up when you're designing +the project. + +Because you design a project +very differently if you're + +just trying to treat a small +area than if you're thinking + +about, if I get this right, +I want to do it on + +a much wider area. + +If you've always got that in +mind, you're thinking a lot + +about is this scalable? + +Am I using a resource that is +either money or expertise that + +is in very short supply, in +which case there's no point in + +designing it this way because +I won't able to scale it + +beyond this small study area. + +So if that's your ultimate +objective, you need to be + +putting that into the impact +evaluation from the moment. + +Because there's no point in +doing the impact evaluation, + +very resource-intensive +project, and + +say, well, that works. + +But I can't do that +everywhere. + +Well then what have +you learned? + +You want to be testing the thing +that ultimately you're + +going to be able to +bring everywhere. + +So in a lot of our cases, we're +encouraging our partners + +to scale it back. + +Because you won't be able to +do this on a big scale. + +So scale it back to what you +would actually be doing if + +you're trying to do the +whole of India or the + +whole of this state. + +Because that's what's +useful to learn. + +And you want to be able +to sell to someone + +to finance the scale-up. + +So I think having those ideas in +your mind at the beginning + +is very important, and as they +say, making it into a + +strategy, not a project by +project evaluation, but + +thinking about where do I want +to go as an organization. + +What's the evidence I need to +get there, and then designing + +the impact evaluations to +get you that evidence. + +And people often ask me about +how do you make sure that + +people use the evidence from +impact evaluations. + +And I think the main +answer to that is + +ask the right question. + +Because it's not about +browbeating people to make + +them read studies afterwards. + +If you find the answer to an +interesting question, it'll + +take off like wildfire. + +It will be used. + +But if you answer a stupid +question, then nobody is going + +to want to read your results. + +So we're learning from an impact +evaluation, so learning + +from in a single study did the +program work in this context? + +Should we expand it to +a similar population? + +Learning from an accumulation +of studies, which is what we + +want to get to eventually, is +did the same program work in a + +range of different contexts, +India, Kenya, south of the + +United States? + +And that's incredibly valuable +because then your learning is + +much wider and you can take +it to many more places. + +Did some variation in the same +program work differently, ie., + +take one program and try +different variants of it and + +test it out so that we know +how to design it. + +Did this same mechanism +seem to be present + +in different areas? + +So there's a lot of studies +looking at the impact of user + +fees in education and health. + +You seem to get some very +similar results. + +And again, that's even +more useful. + +Because then you're not just +talking about moving deworming + +to another country. + +You're talking about +user fees. + +What have we learned about +user fees across a lot of + +different sectors? + +There's some common +understandings and learnings + +to take to even a sector +that we may not + +have studied before. + +And then, as they say, putting +these learnings in the place, + +in filling in an overall +strategy of what were my gaps + +in knowledge? + +And am I slowly filling +them in? + +So, I think that's it. + +So I'm sorry the last bit +was a little bit rushed. + +The idea was to kind of +motivate why we're + +doing all of this. + +Today you're going to +be in your groups. + +The task for your groups today, +as well as doing the + +case, is to decide on a question +for an evaluation + +that you're going to design +over the next five days. + +So hopefully that's made you +think about what's an + +interesting question. + +What should we be testing? + +Because I think often an +underlooked element of + +designing an evaluation is +what's the question that we + +want to be answering with +this evaluation? + +Is it a useful question? + +How am I going to use it? + +What's it going to tell me for +making my program, my whole + +organization more effective +in the future? + +So any questions? + +AUDIENCE: What would you say +are some of the main + +limitations of randomization? + +So I assume one of them is +extrapolate the populations + +that are different? + +Are there other main ones +that you can think of? + +RACHEL GLENNERSTER: So it's +important to distinguish when + +we talk about limitations. + +One is just general, what's +the limitation to say, + +extrapolating beyond? + +But the other thing is to think +of it in the context of + +what's the limitation versus +other mechanisms? + +Because, for example, the +extrapolating to other + +populations is not really a +limitation of randomized + +evaluations compared to +any other impact. + +Any impact evaluation is done +on a particular population. + +And so there's always a question +as to whether it + +generalizes to another +population. + +And the way to deal with that is +to design it in a way that + +you learn as much as you +possibly can about the + +mechanisms, about the routes +through which it worked. + +And then you can ask yourself +when you bring it to another + +population, do those routes +seem like they might be + +applicable, or is there +an obvious gap? + +This worked through the +local organization. + +But if that organization isn't +there, is there another + +organization that it could work +through there or not? + +If you think that deworming +works through the mechanism of + +anemia, well it works between +the mechanism of there being + +worms and of anemia, you +can go out and test. + +Are there worms in the area? + +Is the population anemic because +there may be worms and + +they're not anemic. + +So that's a way to design the +evaluation to limit that + +limitation or reduce the problem +of that limitation. + +But it's not like the very +active flipping a coin and + +randomizing causes the +problem of not being + +able to extend it. + +It's true of any impact +evaluation. + +I think one limitation which +you will find in your + +frustration as you want to try +and answer every single + +question that you have, and you +get into the mechanics of + +sample size and how much +sample size do I need-- + +and again, that's not +necessarily just of a + +randomized evaluation, but any +quantitative evaluation-- + +you can test a limited +number of hypotheses. + +And every hypothesis you want +to test needs more sample. + +And so the number of questions +you can answer very rigorously + +is limited. + +And I think that's the +limitation that we often find + +very binding. + +Again, any rigorous quantitative +evaluation will + +have that limitation. + +We'll talk a lot tomorrow +about sometimes + +you just can't randomize. + +Freedom of the press is not +something that you can + +randomize except by country. + +And then we'd need every +country in the world. + +It's just not going to happen. + +So we'll look at a lot of new +techniques or different + +techniques that you can use to +bring randomization to areas + +where you think it would be +impossible to bring it to. + +Compared to other quantitative +evaluations, you sometimes + +have political constraints about +where you can randomize. + +But as I say, quantitative +versus qualitative, the + +qualitative isn't so limited +by sample size constraints. + +And you're not so limited +to answer very specific + +hypotheses. + +The flip side is you don't +answer any specific + +hypotheses. + +And it's the same +rigorous way. + +But it's much more open. + +So very often what we do is we +combine a qualitative and + +quantitative, and spend a lot +of time doing qualitative + +before to hone our hypotheses, +and then use a randomized + +impact evaluation to test +those specific. + +But if you sit in your office +and design your hypotheses + +without any going out into the +field, you will almost + +certainly waste your money +because you won't have asked + +the right question. + +You won't have designed it. + +So you need some element of +qualitative to make sure some + +needs assessment, some work on +the ground to make sure that + +you are asking, you're designing +your hypotheses + +correctly because you've +only got a few shots. + +Yeah? + +AUDIENCE: I was wondering, +do you know of some good + +evaluation or randomized +impact evaluation on + +conservation programs? + +RACHEL GLENNERSTER: On +conservation programs? + +I can't think of any, I'm +afraid, but eminently doable. + +But we can talk about that if +you can persuade your group to + +think about designing one. + +Anyone else think of a +conservation program? + +Yes? + +AUDIENCE: I don't +have an example. + +I wish I did. + +And you've mentioned this. + +I just need to really underline +it for myself. + +A lot of the programs that +my organization does are + +comprehensive in nature. + +So they have lots of different +elements meant to in the end, + +collectively, +[UNINTELLIGIBLE PHRASE]. + +What I'm understanding here is +that you could do an impact + +evaluation of all of +those collectively. + +But really it would be more +useful to pull them out and + +look at the different +interventions + +side by side or something. + +Because that way you'll +get a more targeted-- + +RACHEL GLENNERSTER: It's true. + +The question was, if you have a +big package of programs that + +does lots of things, you can do +an evaluation of the whole + +package and see whether +it works as a package. + +But in terms of learning about +how you should design future + +programs, you would probably +learn more by trying to tease + +out, take one away, or +try them separately. + +Because there might be elements +of the package that + +are very expensive but are not +generating as much benefit as + +they are cost. + +And you would get more effect by +doing a smaller package in + +more places. + +You don't know unless you +take the package apart. + +Now then if you test each one +individually, that's a very + +expensive process. + +Because it needs a lot of +sample size to test each + +individually. + +There's also a very interesting +hypothesis that's + +true in lots of different +areas. + +People often feel, where there +are lots of barriers, so we + +have to attack all of them. + +It only makes sense. + +You won't get any movement +unless you do. + +There are lots of things +stopping kids going to school. + +There's stopping, say, girls +going to school. + +They're needed a home. + +There are attitudes. + +There is their own health. + +There's maybe they +are sick a lot. + +So we have to address all +of those if we're + +going to have an impact. + +We don't know, the answer is. + +And indeed, in that example +where we're working with Save + +the Children in Bangladesh, +they had this + +comprehensive approach. + +Where there are all +these problems. + +So let's tackle them all. + +We convinced them to divide it +up a bit, and test different + +things, and see some of their +own worked, or whether you + +needed to do all of them +together before you changed + +anything, which is a perfectly +possible hypotheses and one + +that a lot of people have, but +hasn't really been tested. + +The idea that you've got to get +over a critical threshold. + +And you've got to +build up to it. + +And only once you're over there +do you see any movement. + +Well actually on girls going +to school, it's quite + +interesting. + +Most of the evaluations that +have looked at, just + +generally, improving attendance +at school, have had + +their biggest impact on girls. + +I should say most of those were +not done in the toughest + +environments for girls +going to school. + +They're not in Afghanistan +or somewhere where it's + +particularly difficult. + +But it is interesting. + +Just general things and +approaches in Africa and India + +have had their biggest impacts +on girls, which suggests that + +you've got a hit every +possible thing + +is maybe not right. + +Yeah? + +AUDIENCE: [INAUDIBLE PHRASE] + +and the political constraints +[INAUDIBLE PHRASE]. + +RACHEL GLENNERSTER: Right. + +So we'll talk actually tomorrow +quite a lot about the + +politics of introducing an +evaluation or at least the + +different ways that you can +introduce randomization to + +make it more politically +acceptable. + +That's slightly different from +whether the senior political + +figures want to know whether +the program works or are + +willing to fund an evaluation. + +I've actually been amazingly +surprised. + +Obviously we find that +some places. + +There are certain partners +or people we've + +started talking with. + +And you can see the moment the +penny drops that they're not + +going to have any control. + +Because you're going to do +a treatment comparison. + +You're going to stand back. + +At the end of the day the +results going to be that. + +There's no fiddling with it, +which is one of the beauties + +of the design. + +But it will be what it will be, +which is kind of why it's + +convincing. + +But there are certain groups who +kind of figure that out. + +And they run for the exit +because there's going to be an + +MIT stamp of approval evaluation +potentially saying + +their program doesn't work. + +That's life. + +Some people don't +want to know. + +The best thing I can say in +that situation is test + +alternatives. + +It's much less threatening +to test alternatives. + +Because there's always some +alternative of this versus + +that, that people don't know. + +And then you're not raising +the does it work. + +You're saying well, does this +work better than that? + +And that is much less +threatening. + +It doesn't tell you +quite as much. + +But it's much less +threatening. + +There's a report called When +Will We Ever Learn, looking at + +the politics of why don't we +have more impact evaluations, + +which was very pessimistic. + +But if you look at somewhere +like the World Bank that just + +put a purse of money for +doing randomized impact + +evaluations out there. + +And anybody in the +bank could apply. + +And people were like why? + +There's no incentives +for them to do it. + +Program office's, they've +already got a + +lot on their plate. + +Why would they add doing this? + +It's going to find out that +they're opening themselves to + +all these risks because maybe +their program doesn't work. + +Massively oversubscribed, first +year, six times more + +applicants then there +was money. + +It just came out of the woodwork +as soon as there was + +some money to do it. + +So I'm not saying every +organization is like that. + +Obviously not everybody in +their bank did that. + +But it was, to me, actually +quite surprising how many + +people were willing +to come forward. + +Now we have the luxury of +working with the willing, + +which if you're working within +an organization, you don't + +necessarily have that luxury. + +You will see as you get into the +details of these things, + +that you need absolutely full +cooperation and complete + +dedication on the part of the +practitioners who were doing + +these evaluations alongside +the evaluators. + +You can't do this with +a partner who + +doesn't want to be evaluated. + +It just doesn't work. + +They are so able to throw monkey +wrenches in there if + +they don't want to find +out the answer. + +Then it's just not worth +doing it because it's a + +partnership like that. + +It's not someone coming along +afterwards and interviewing. + +It is the practitioners and the +evaluators working hand in + +hand throughout the +whole process. + +And therefore if the +practitioners don't want to be + +evaluated, there's not a hope +in hell of getting a result. + +We should wrap up. + +A lot of these things we're +going to talk about. + +But I'll take one more. + +Yeah? + +AUDIENCE: How important, or +how relevant is it, or how + +much skepticism can there be +about a case where the + +evaluators and the practitioners +work for the + +same people or are funded +by the same people? + +RACHEL GLENNERSTER: Yeah, we've +even got practitioners + +as co-authors on our studies. + +This is another place where I +kind of part company from the + +classic evaluation guidelines, +which say that it's very + +important to be independent. + +I'd argue if your methodology is +independent, what you want + +is not independence. + +You want objectivity. + +And the methodology of a +randomized evaluation can + +provide you the objectivity. + +And therefore you don't have to +worry about independence. + +Now there's one caveat +to that. + +The beauty of the design is +you set it up, as I say. + +Well you don't stand +back in the sense. + +You've got to manage all your +threats and things. + +But you can't fiddle very +much with it at the end. + +The one exception +to that is that + +you can look at subgroups. + +So there was an evaluation in +UK of a welfare program. + +And it was a randomized +evaluation. + +And there was some +complaining. + +Because at the end, they went +through and looked at every + +ethnic minority. + +and then you know I can't +remember whether it did work + +in general. + +But it didn't work for one +minority, or it didn't work. + +But anyway, you can find one +subgroup for whom the result + +was flipped. + +And that was the thing on the +front page of the newspapers, + +rather than the overall +effect. + +So there's a way to deal with +that, which is increasingly + +being stressed by people who are +kind of looking over the + +shoulder and making sure that +what is done in randomized + +evaluations is done properly, +which is to say that you need + +to set out in advance-- + +we'll talk about this a bit +later on-- but you need to set + +out in advance what you're +going to do. + +So if you want to look at a +subgroup like does it affect + +the lowest performing kids in +the school differently from + +the highest performing kids-- + +do I care most about the +lowest performing kid-- + +if you want to do that, you need +to say you're going to do + +that before you actually +look at the numbers. + +Because even with a randomized +evaluation, you can data mine + +to some extent. + +Well if I look at least ten +kids, does it work for them? + +If I look at least ten kids, +does it work for them? + +Statistically you will be able +to find some subset of your + +sample for whom it does work. + +So you can't just keep trying +100 different subgroups. + +Because eventually it will +work for one of them. + +So on the whole, you +need to look at the + +main average effect. + +What's the average effect +for the whole sample? + +If you are particularly +interested in a special group + +within the whole sample, you +need to say that before you + +start looking at the data. + +So that's the only way in which +you get to fiddle with + +the results. + +And otherwise it provides an +enormous amount of objectivity + +in the methodology. + +And therefore, you don't have +to worry so much about a + +Chinese wall between the +evaluators and the + +practitioners, which, I think, +is incredibly important. + +Because we couldn't do the work +that we do if we had that + +Chinese wall. + +It just wouldn't make sense, +doing your theory of change, + +finding out how it's working, +designing it so it asks the + +right questions. + +None of that would be possible +if you had wall between you. + +So it just wouldn't be anything +like as useful. + +So getting your objectivity from +the methodology allows + +you to be very integrated +with the evaluation, and + +practitioners to be +very integrated. \ No newline at end of file diff --git a/ICa_4xUr8BA.txt b/ICa_4xUr8BA.txt new file mode 100644 index 0000000000000000000000000000000000000000..6500d889af8774d158800c2ca177f9c8a501898f --- /dev/null +++ b/ICa_4xUr8BA.txt @@ -0,0 +1,89 @@ +MIT OpenCourseWare is a publication of MIT +course materials. There is no registration + +for the site, and all materials are completely +free to use. + +Courses are published on OpenCourseWare after +they have been taught at MIT. + +You'll find courses that were taught ten years +ago, but are just as relevant today, such + +as Classical Mechanics. But you'll also find +courses taught recently on timely issues like + +repairing the Hubble telescope. 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It's all the same material as +what you see online, except we leave out video + +and audio files to keep the file from getting +too large. + +You can download those files from our partner +sites, like iTunes U. + +We have collected all courses that have video +or audio resources in one list here. + +With more than one million visitors each month, +we can't answer all of the questions you might + +have while using the site, and we can't connect +you directly to MIT faculty. But a lot of + +your questions may be answered in our Help +section. + +We publish 50 new courses every year, and +update 100 older courses with new material. + +So check back frequently for updates. + +Many of our course lists are available as +RSS feeds. You can subscribe to these feeds + +and get an alert whenever we publish new content +in the areas that interest you. + +Our monthly newsletter contains a list of +recently-published courses, alerts about site + +features, and stories of how our content is +used by people around the world. + +OpenCourseWare is free to use, but we rely +on donations from users like you to support + +the publication. + +Explore the site. Watch a video lecture. Try +a practice problem. We always appreciate feedback + +or suggestions for improvement. You can contact +us by emailing ocw@mit.edu. \ No newline at end of file diff --git a/JB2HgohNHYQ.txt b/JB2HgohNHYQ.txt new file mode 100644 index 0000000000000000000000000000000000000000..338994bf8361ef70e4e3c53113f153dd6cafcfc2 --- /dev/null +++ b/JB2HgohNHYQ.txt @@ -0,0 +1,1570 @@ +All right, let's get moving. +Good morning. + +Let me take a quick poll. +So, how many of you have + +completed Lab 4. +Completed Lab 4? + +Wow, that's great. +So, how many people have begun + +Lab 4? +OK, well that's good. + +I won't ask the last question. +OK so, well I hope you're + +having fun with this lab. +Lab 4 was designed to be almost + +like a mini-project. +And, it sort of ties together a + +lot of the content of the entire +course. + +And, it's not unlike the kind +of systems that people design in + +industry, in systems that go +into a variety of devices like, + +say, for example, +digital CD players and stuff + +like that. +A lot of mixed signal stuff + +goes in. +OK, so today, + +I'm going to continue with our +discussion of energy and CMOS. + +CMOS will be a new topic that I +will introduce. + +So, the last lecture, +we spent a fair bit of time + +talking about energy, +and how to compute the energy + +of our inverter. +So, let me start from where I + +left off, and I've given you a +couple of extra pages of notes + +today just to sort of tie it to +the previous lecture. + +Right now, I'm going to start +off on page three. + +So, what we saw last time was +an inverter of this sort, + +Vs, VIN, and we said, +let's study the situation where + +this inverter was driving a load +capacitor, C. + +Where did this load capacitor +come from? + +Well, this inverter could be +driving one, or two, + +or three, or four other larger +gates, OK? + +So, this C is lumped value of +the gate capacitances of all of + +those inverters. +This may also include some + +component due to wiring +capacitance and stuff like that. + +So, for an inverter like this, +we showed in the last lecture + +that the formula for the average +power was, + +so this was a static power +independent of frequency, + +and this was called dynamic +power, and it had some bearing, + +it's related to the frequency +at which you clocked your + +circuit. +So, this was related to standby + +power, and this to dynamic. +So, what I also said is that I + +gave you a bunch of numbers so +you could compute the power + +consumption of a chip that +included 10^8 gates, + +100 million gates, +and at a frequency of 1 GHz, + +and a bunch of other numbers. +C was given to be 0.1 + +femtofarads. +Femto is 10^-15. + +So, F was 10^9. +VS was 5V, and for these + +numbers, if you plonk them down +in something like this, + +for 10^8 gates on a chip, +the average power would be 10^8 + +times these two. +So, this would be five squared, + +which is 25, +divided by twice. + +RL was given to be 10 +kilo-ohms, so, + +twice, 10^4. +And here we had CVS^2. + +So, C was 10^-16, +0.1 femtofarads. + +Vs^2 was 25, +and F was 10^9. + +So, if you commence through the +numbers here, + +what you end up getting is +something that looks like this, + +10^8 times this guy here. +This is 1.25mW plus this guy + +ends up being 2.5 microwatts. +So, this should come as a bit + +of a shocker. +If I take 1.25mW, + +and multiply that out by 10^8, +this says that each gate + +suffers a standby power loss of +1.25mW. + +So times 10^8, +I get 125kW, + +and this guy yields 250W. +OK, the 250W is manageable. + +It's still high, +and just so you don't think + +that this is unreasonable, +when the Pentium 4 first came + +out, it was consuming 170W of +power. + +OK, you should see the heat +sinks on there. + +There's actually a huge heat +sink with a fan built into the + +top of the heat sink. +OK, today it's down to more + +reasonable numbers like 100W and +so on, but when it came out it + +was in this range. +So it's high but not + +unreasonable. +But this, of course, + +is totally wacko. +OK, imagine carrying a laptop + +around, and the sucker is +blowing 125kW. + +That'll be fun. +So, clearly there's something + +wrong here. +What this is saying is that + +this gate here consumes 125kW, +there are 10^8 of these on a + +single chip. +OK, so we clearly have to do + +something about this, +otherwise the semiconductor + +industry would fail. +So, anybody have any ideas? + +What do you think you might do +here? + +What do you think you might do +to this inverter to make this + +look better, to bring it down? +What can I do? + +Anybody? +Any ideas? + +What do you think? +Well, the problem is that if I + +look at this 125kW, +well, there's a VS term here + +and an RL term here. +So, I can increase RL. + +OK, I can make RL four times or +eight times as large. + +That'll bring the power down +somewhat. + +Can anybody think of any +problem with increasing RL? + +If I make RL really, +really large, + +will I run into other problems? +Yes? + +Exactly, the slowdown of the +inverter. + +Remember, the rise time of the +inverter depends on how quickly + +I can charge this capacitor +through RL. + +So, if I make my RL really +large, I will consume less + +standby power from hundreds of +kilowatts to merely tens of + +kilowatts. +But my gates will run as slow + +as molasses. +So, clearly that's not a + +tradeoff I would like to make. +So, I can reduce my voltage to + +maybe a volt. +But that just reduces it by a + +factor of 25, +VS squared. + +So clearly, this is not going +to work. + +I have to somehow do something +else, and that will be the topic + +of today's lecture. +Also, I will dwell for a moment + +on this term. +So, if you look at the spec + +sheet for the IBM's ASIC +processor that we handed out, + +if you recall, +we talked about power + +dissipation of 0.006 microwatts +per MHz per gate. + +OK, now you see where this is +coming from. + +Per MHz, that's because it's a +multiple of f, + +the power. +Second is that it's per gate, + +so this is the power per gate. +So, as I have more gates, + +I just have that much more +power dissipation. + +It also says power supply +voltage in the range of 0.7 to + +1.3 right next to the power +expression. + +So, you can see why they tell +you all of that, + +because both voltage, +and the frequency, + +and the number of gates come +into the power of equation. + +OK, this really simple +expression here, + +it's amazing how close this is +to what people use for the + +dynamic power in chips. +OK, so as the next step, + +what I'd like to do is, +this guy, what do we do about + +that? +OK, so we've taught you to + +build gates in a particular +matter, but it's a non-starter. + +So, how do we get rid of static +power? + +How do we get rid of static +power? + +OK, to do so, +let's build up a little bit of + +intuition. +OK, so the intuition goes as + +follows. +So let's say I take my + +inverter. +Let me draw the circuit both on + +the on state and in the off +state. + +So, when VIN is high, +when VIN is high, + +I get the MOSFET turning on and +has a resistance, + +RON, and Vo is the output +voltage. + +Similarly, when VIN is low, +so when VIN was high, + +Vo was low because RON is much +less than RL. + +So, this voltage was low, +while here, when VIN is low, + +the MOSFET is off, +and so I have an open circuit + +out here. +And because of that open + +circuit, the voltage here was +going to be high because VS + +would simply appear there. +So let's tailor this and see if + +we can build up some intuition +as to what to do. + +So, when VIN is low, +I don't have any static power + +being dissipated because I don't +have a connection from VS to + +ground. +OK, the current, + +i, is zero. +And, VS simply appears at the + +output. +The reason this is so is have a + +switch here. +So when this is low, + +the switch opens up and cuts +the path from power to ground. + +This is a nice situation. +Here, when VIN was high, + +there was no switch that turns +off. + +Rather, I get a connection from +VS to ground. + +OK, so think about this +situation here. + +The insight here is, +just imagine if I could do the + +following. +Imagine if I could somehow + +magically elevate RL to be a +very, very, very large number, + +if I could make this so high as +to make the power really low + +only in the situation when the +input was high, + +OK? +So, imagine if I could do + +something like this. +Imagine I could open circuit + +this guy, RON, +so when VIN was high, + +if I could, instead of having +an RL here, what if somehow I + +could make this RL become +infinity? + +OK, so in this case, +output VO would be low. + +OK, I get many benefits by +doing this. + +One benefit is that, +look, I have opened this switch + +here so I don't have any standby +current. + +OK, the standby current is +zero. + +The second benefit is that my +output gets dragged down to + +ground, OK? +Out here, my output was VS + +multiplied by RON divided by the +sum of these two. + +Out here, I have a direct +connection to ground, + +and nothing to the power +supply, VS, and so therefore I + +have a nice, solid low. +So the question is that, + +can I get this situation? +OK, that is a key insight. + +So, imagine that somehow, +when this was high, + +I could get this to open up, +much like when this was low, + +I got this to open up. +OK, so think about it. + +So, the intuition is that what +I need instead of a resistor + +here, what if I have something +like the MOSFET that I have + +here? +So, I have a MOSFET here that + +turned off when VIN was low. +OK, what if I did the + +complementary thing? +What if I put in some kind of + +MOSFET here that would turn off +when VIN was high? + +OK, so, much like the MOSFET +turned off when VIN was low down + +here, imagine if I could find a +device that could turn off when + +VIN was high? +OK, this would be on, + +but this would be off. +So the behavior of this device + +would have to be complementary +to this device. + +So, we need some sort of a +switch to introduce this new, + +little MOSFET device with +slightly different properties, + +let me quickly review for you +the properties of the MOSFET + +that we know about, +so our N channel MOSFET, + +also called the NFET, +this is what we've been seeing + +all this while, +is drawn like this. + +I have a gate; +I have a drain; + +I have a source. +And this guy is on when VGS is + +greater than or equal to VT, +OK, and off when VGS is less + +than VT. +You saw this before, + +OK, nothing new here. +So, what I need is a device + +that behaves in a complementary +manner. + +OK, so the device is a P +channel MOSFET. + +By the way, I must point out, +till about 1983-84 until the + +early '80s, that's exactly +pretty much how chips were + +designed, OK, +using an NFET for the switch + +looking down here, +and a variety of different + +kinds of devices to be used as +resistors. + +OK, that's when technology +began moving towards this new + +kind of technology I'm going to +talk about, and that + +dramatically reducing the power +consumed. + +And, the P channel MOSFET was +created, and this guy's called + +the PFET. +It's a complementary device + +that looks as follows. +OK, the difference here is + +that, to show this is +complementary, + +I'll put a little circle here. +It has a gate. + +Just to make things a little +clearer, flip the drain and + +source terminals, +and this guy is on at a + +distinguished threshold voltage +of this with the NFET device, + +let me put an N here to say +that this is the VT for the N + +channel device. +And for this guy, + +this guy came on when VGS was +greater than some voltage. + +So, VTN could be, +for example, + +one volt. +So, VGS was more than one. + +This turned on. +In this case, + +I wanted this to turn on when +VGS is some value which is lower + +than, or much lower than, +the source voltage. + +OK, so this guy turns on when +the gate voltage is higher. + +This guy should turn on when +the gate voltage is + +significantly lower than the +source voltage, + +just the complementary +behavior. + +OK, so when VGS is less than or +equal to VTP. + +And in this case, +the threshold voltage for the + +PMOS device, say, +just as an example, + +maybe -1V. +So this means that if the + +source is at, +say, 5V, OK, + +then this device would turn on +if the gate, for example, + +using that example was less +than 4V. + +So, this is five. +If the gate fell below 4V, + +this guy would turn on. +In this situation, + +remember, if this was at zero, +the gate would have to be + +greater than 1V to turn on. +In this situation, + +the gate has to be less than 4V +if the source was at five to + +turn on. +And, it's off. + +OK, so this is a complementary +device that I postulate that + +behaves in a complementary +manner. + +So, the gate voltage rises, +this guy turns on, + +and in this situation, +when the gate voltage drops + +below the source voltage, +this guy turns on. + +OK, so when there's a rising +guy that turns on in this + +particular situation when it +falls, the gate turns on and + +shows some resistance. +In this case, + +the resistance would be RON. +And to show that it's N + +channel, let me say N. +And in this case, + +the resistance, +when it turns on, + +would be RONp to represent P +channel. + +OK, so now consider the +following circuit for the + +inverter. +So, instead of my resistor, + +I put a complementary device, +OK, and that's it. + +So all I've done here is +replace my resistor with a + +MOSFET that behaves +complementary to the N channel + +MOSFET. +So this is my gate, + +my drain. +This is my source, + +my gate, my source, +and my drain. + +OK, and this guy is called a +pull up, and this guy is called + +a pull down. +OK, and the reason is that this + +guy pulls the output to ground +when it's turned on, + +while this guy, +when switched on, + +will pull this node up to VS. +So, I pull it down or pull it + +up based on when the VIN is high +or low. + +So, let's look at the two +situations. + +So, let's say, +as an example, + +my VS is 5V, +and let's say VIN in one + +situation being 5V, +and another situation being + +equal to 0V. +Let's draw the equivalent + +circuit in both these cases. +So, when VIN is high, + +I have my usual circuit. +When VIN is high, + +this MOSFET, +as before, when VIN is 5V, + +the N channel MOSFET below is +turned on, and so I have an RON + +resistance here. +But remember, + +VIN is 5, and VS is 5V, +then the voltage across the + +source and the gate of this P +channel FET is now equal, + +five and five. +OK, so this one would turn off. + +And that's the circuit that I +get. + +The output is suitably low. +In this situation, + +if VIN is zero, +what happens in this situation? + +Here's my output. +If VIN is 0V, + +the lower device turns off. +This is zero. + +This is zero. +This guy turns off, + +and that's the situation for +the N channel MOSFET. + +How about this guy here? +What happens here? + +This is at 5. +So let me just, + +this is at 5V. +OK, and VIN is at 0V. + +OK, so therefore, +the GS of this is -5V. + +If this is zero and this is +five, G, source, + +and drain, GS is -5V, +and -5V is significantly less + +than the threshold -1V in our +example. + +So, this one will switch on. +And if this one switches on, + +what I end up getting is RONp +out there. + +So, when this one kicks in, +it pulls the output high and VO + +goes high. +So, all I've done is replaced + +my resistor with a complementary +device, which switches off when + +the input is high, +and switches on when the input + +is low. +And the beauty of this is that + +at no point, assuming all the +devices are ideal here, + +at no point do I have a short +circuit between the output, + +do I have a current path from +the output to the ground from + +the supply to ground, +OK, I have this turned off or + +this turned off. +So, this type of logic + +involving a PMOS transistor +here, and the N channel + +transistor here is called CMOS +logic for, OK, + +it's called complementary MOS +logic. + +That's what CMOS comes from. +OK, so I'm sure you've read in + +a number of places that most +digital chips today use CMOS + +technology. +It comes from complementary + +MOS, and complementary comes +from the use of complementary + +transistors: N channel, +P channel, turns on when high, + +turns off when high, +turns off when low, + +turns on when low. +OK, that's exactly + +complementary to each other. +OK, so what you've seen here + +has been the workhorse of the +digital industry for the past + +two decades, 20 years, +CMOS logic. + +OK, and even the most advanced +chip from Intel has an inverter + +that looks exactly like that. +OK, if you count all the + +inverters in the universe today, +I would say a significant + +fraction of those look exactly +like that, no difference, + +just so simple. +So, the key with something like + +that is there is no path from +the power supply to the ground, + +and so by that model, +I did not consume any standby + +power. +OK, my standby power in that + +idealized model is zero. +So, let's compute P. + +So, what is P dynamic? +Let's use the method that we + +adopted in the last lecture, +and draw the equivalent + +circuit, and compute the power. +OK, so I'm going to model the + +following situation, +and assume that I drive a + +capacitive load, +C. + +OK, and as an input, +as I did the last time, + +I'm going to assume I have some +input voltage, + +VIN, that looks like this. +The cycle time, + +T, and the frequency is 1/t, +and let me assume that this is + +T1, and this is T2. +OK, and I'm assuming that T1 + +and T2 are both much larger than +the respective time constants. + +OK, the time constants when, +for discharging here, + +is C RONn, and here the +relevant resistance is RONp. + +The charging time constant is +RONp times C. + +OK, so T1 and T2 are assumed to +be much greater than these two. + +So when you look at this, +there's one other benefit + +besides the power benefit, +OK, of using CMOS logic + +compared to using NMOS. +OK, it not only cuts out my + +standby power, +but there is another + +significant advantage which is +almost equal to the power + +advantage of this kind of CMOS +technology. + +Anybody have any ideas? +What's the advantage? + +What does intuition tell you? +Is CMOS going to be faster or + +slower than NMOS? +Why? + +That's right. +The key here is that the NMOS + +design I showed you earlier was +relatively slow because it took + +me a while to charge up the load +capacitor from RL. + +In this situation, +RL will become really, + +really small; +it's RONp. + +It's roughly the same magnitude +as RONm. + +OK, if so both of these on +resistances are more or less + +equal and small, +then the rise time will be of + +the same order of magnitude as +the fall time, + +which makes this much faster +than the NMOS. + +In NMOS, my time constant was +RLC, and RL was pretty large. + +In this case it's RONp C, +and RONp can be made to be very + +small because when it's switched +off, the resistance here is + +infinity. +So, in this situation, + +if I assume T1 and T2 are much +larger than the respective time + +constants, I can go ahead and +draw my equivalent circuit. + +So, here's VS. +So, for charging up, + +let's say this one is going to +a one, or to a high. + +So, I have VS going through a +resistor, RONp, + +to a capacitor, +and this thing is a switch. + +So I have RONp, +an ideal switch, + +going to a capacitor, +C, this is my V out node, + +OK, so it's VS going through a +resistance, RONp, + +an ideal switch, +to a capacitor, + +C. +That's a charging circuit. + +For discharging, +I have C, discharging through + +an ideal switch with RONn. +So, this situation, + +I have an ideal switch, +RONn. + +OK, so that's the equivalent +circuit for something like this. + +So, in this circuit, +during T1, this guy's off, + +and this guy's on, +on during T1, + +and off otherwise. +This guy is on during T2, + +and off otherwise. +OK, so just imagine, + +this guy switches on, +this guy switches off, + +this guy switches on, +this guy switches off, + +OK? +And remember, + +this is exactly the circuit I +had analyzed last time in the + +last lecture, +and the result given by v + +double asterisk. +And that result was simply + +average power being CVS^2f. +That's the exact circuit we + +used to compute the dynamic +power, CVS^2f. + +OK, so we're done. +And how did this come about? + +This came about because the +intuition here is that I'm + +charging up the capacitor fully, +and then I'm discharging the + +capacitor through this other +side, OK, and I'm consuming + +power, dissipating power, +in these two resistances during + +charge up and during the +discharge. + +Half the power gets consumed +during charge up, + +and half during the discharge. +So, I'd like to go back to + +doing a few numbers here, +and taking a look at how, + +even with this expression, +life can get pretty thorny as + +we go ahead into the next +decade. + +OK, so for our previous +example, we assumed that 10^8 + +gates, F=1 GHz, +C=0.1 femtofarads, + +VS was 5V, and I don't need RL +anymore. + +OK, why is it that I don't have +any resistance component here? + +I don't have it here because +the power consumed by this + +circuit is independent of those +resistances, provided T1 and T2 + +are long enough, +are much longer than the two + +time constants, +RONp C, and RONn C. + +OK, so I don't have RL in my +equation anymore. + +I don't have any standby power. +So, based on this calculation, + +the calculation I did up there +showed that I had 2.5 microwatts + +per gate, and for 10^8 gates I +had 250W for a chip with 10^8 + +gates. +So, I'd like to dwell on this, + +if you can move over to page +eight in your notes, + +here. +Let me dwell on this for some + +time, and pontificate on a few +things. + +First of all, +this number, + +as I said before, +is high, but not a disaster. + +OK, so you can't use this in +laptops, but it's quite OK for a + +desktop or a server, +and so on. + +If you just go and put your ear +to a pedestal computer, + +you'll always hear it making a +sound, and that sound is because + +of a big fan that's inside it. +And, if you have a big enough + +fan, 250W is not such a big +deal. + +But, this is certainly a real +problem for mobile devices. + +For a laptop, +this is unthinkable. + +OK, so we have to deal with +this. + +The second issue is the +following, that it's 250W for + +1GHz. +Now, the fastest Pentium 4s + +that money can by today are, +what, how many GHz? + +What's the fastest Pentium 4 +you can buy today? + +What's that? +Does anybody have a 4GHz + +Pentium 4 here? +Oh, darn, you beat me. + +Anybody have a 3? +3GHz? + +A couple. +So, I have a couple of 3GHz + +machines, and our lab has a +whole ton of them. + +So, if Intel comes out with +4GHz machines today, + +they've been going up by about +1GHz roughly every year for the + +past couple of years. +And, within three or four + +years, you're going to see +chips, microprocessors that are + +in the 5-10GHz range, +OK, assuming that all other + +things stay equal, +which of course they're not, + +but just to give you some +insight here, + +if I clock these guys and build +circuits that are ten times + +faster, I very soon go up to +2.5kW, again as I said, + +all things being equal which +they're not. + +But just to give you a sense, +as I increase my frequency, + +so does the power consumed by +the chip, OK? + +So, I really have to do +something here. + +So, if I stare at this +equation, CVS^2f, + +I want to increase f because +people will buy computers if I + +have higher frequencies. +And, Intel has managed to use + +its marketing campaigns to +pretty much convince consumers + +that high frequencies are a good +thing. + +OK, and whether they really +mean anything or not, + +that's a different issue. +So, we've got this huge power + +for assuming 5V, +OK, so it turns out that + +microprocessors, +as they come out, + +newer and newer versions run at +lower and lower voltages. + +OK, they invent technologies +that use lower and lower + +voltages, and go from VS 5V to, +today, VS on the order of 1.5 + +to 1V, somewhere in that range. +So the moment you do that, + +you get a 25x reduction in +power. + +OK, so in going from 2.5kW, +you would now come down to + +something on the order of 100W, +which is, again, + +much more reasonable, +again, all other things being + +equal. +It turns out that the + +capacitance of devices also +changes as you go to smaller and + +smaller devices. +And, 100W is also pretty high, + +and still not good enough for +mobile computers. + +So, there are many, +many other tricks that people + +use to get even lower powers. +One trick is to play games with + +the clock. +OK, what you do is, + +let's say for example in some +computation you are not going to + +be using your floating point +unit. + +Or let's say I'm going to be +using your integer adder unit. + +OK, so what you can do is you +can turn off the clock to those + +devices so that those devices do +not even switch when they're not + +working. +OK, if I turn off the clock to + +a device, the device isn't even +going to switch, + +it's just going to sit there in +limbo without consuming any + +power. +It's equivalent to turning off + +both transistors. +If you turn off both the PMOS + +and NMOS somehow, +OK, it's not consuming any + +power. +And by doing that, + +you can further cut down the +power. + +So, if you can idle some of +your function units, + +it's called idling a function +unit, idle a function unit for, + +let's say, half the time. +OK, you would cut down power by + +another factor of two. +We can idle, + +then, 75% of the time, +come down to 25W. + +So, those are the classes of +tricks that people play. + +I'm going to stop here and +allow the underground guide + +folks to do the survey. +But, suffice it to say that the + +power discussion that I've gone +through with you is a very high + +level discussion as to the real +thing. + +In real life, +what actually happens is that + +there is a fair amount of +standby power even for CMOS + +logic. +It turns out that although I + +don't have a path from VS to +ground for my two transistors, + +it turns out that there are +many leakage currents. + +OK, currents leak through all +kinds of places through the + +drain of the inverter, +and so on and so forth. + +And so, there is some standby +power. + +So, let me show you a quick +demo while, I guess, + +the review handouts are going +around. + +And this shows the temperature +of my CMOS inverter, + +and as I increase the +frequency, you can just watch + +the temperature go up, +and hopefully we'll blow this + +transistor. +So, I'm increasing the + +frequency as you can see on the +side here, and higher frequency + +implies more power consumption, +more temperature, + +OK, and hopefully you will see +some smoke coming out of, + +OK, I think I blew the +inverter. + +So, the output is gone. +So, it's at 110 degrees there, + +and that blew it. +Sometimes we see smoke come + +out, but I guess today is not +one of our lucky days. + +OK, so let me stop here and +have the underground guide folks + +go through the reviews. \ No newline at end of file diff --git a/JZ19Eot3lPc.txt b/JZ19Eot3lPc.txt new file mode 100644 index 0000000000000000000000000000000000000000..77317d15edc477304122ae3618a825d6e71a7aac --- /dev/null +++ b/JZ19Eot3lPc.txt @@ -0,0 +1,14235 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT 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+ align:start position:0% +evening lecture what I'd like to do is + + + align:start position:0% +evening lecture what I'd like to do is +continue a bit to expand on and + + align:start position:0% +continue a bit to expand on and + + + align:start position:0% +continue a bit to expand on and +complicate and maybe also deepen + + align:start position:0% +complicate and maybe also deepen + + + align:start position:0% +complicate and maybe also deepen +this idea I've been suggesting to you + + align:start position:0% +this idea I've been suggesting to you + + + align:start position:0% +this idea I've been suggesting to you +that I'm labeling the fedot principle + + align:start position:0% +that I'm labeling the fedot principle + + + align:start position:0% +that I'm labeling the fedot principle +really a shorthand way of describing the + + align:start position:0% +really a shorthand way of describing the + + + align:start position:0% +really a shorthand way of describing the +immensely complex and from an + + align:start position:0% +immensely complex and from an + + + align:start position:0% +immensely complex and from an +intellectual standpoint to historical + + align:start position:0% +intellectual standpoint to historical + + + align:start position:0% +intellectual standpoint to historical +standpoint immensely exciting and + + align:start position:0% +standpoint immensely exciting and + + + align:start position:0% +standpoint immensely exciting and +astonishing process whereby film went in + + align:start position:0% +astonishing process whereby film went in + + + align:start position:0% +astonishing process whereby film went in +an in an incredibly short time from + + align:start position:0% +an in an incredibly short time from + + + align:start position:0% +an in an incredibly short time from +being a mere novelty to being an + + align:start position:0% +being a mere novelty to being an + + + align:start position:0% +being a mere novelty to being an +embedded social formation in the United + + align:start position:0% +embedded social formation in the United + + + align:start position:0% +embedded social formation in the United +States and and in other industrialized + + align:start position:0% +States and and in other industrialized + + + align:start position:0% +States and and in other industrialized +societies and and not just only a so + + align:start position:0% +societies and and not just only a so + + + align:start position:0% +societies and and not just only a so +embedded social formation becoming by + + align:start position:0% +embedded social formation becoming by + + + align:start position:0% +embedded social formation becoming by +the end of the 1920s one of the central + + align:start position:0% +the end of the 1920s one of the central + + + align:start position:0% +the end of the 1920s one of the central +media for the expression of art an an + + align:start position:0% +media for the expression of art an an + + + align:start position:0% +media for the expression of art an an +artistic medium so that it went from + + align:start position:0% +artistic medium so that it went from + + + align:start position:0% +artistic medium so that it went from +being a mere novelty from Fred artne in + + align:start position:0% +being a mere novelty from Fred artne in + + + align:start position:0% +being a mere novelty from Fred artne in +20 years or so 25 years to being a + + align:start position:0% +20 years or so 25 years to being a + + + align:start position:0% +20 years or so 25 years to being a +medium of astonishingly rich and complex + + align:start position:0% +medium of astonishingly rich and complex + + + align:start position:0% +medium of astonishingly rich and complex +narrative art that progress uh is part + + align:start position:0% +narrative art that progress uh is part + + + align:start position:0% +narrative art that progress uh is part +of what I mean by the um Fred art + + align:start position:0% +of what I mean by the um Fred art + + + align:start position:0% +of what I mean by the um Fred art +principle and and it might be helpful if + + align:start position:0% +principle and and it might be helpful if + + + align:start position:0% +principle and and it might be helpful if +I if I concretize that a little bit more + + align:start position:0% +I if I concretize that a little bit more + + + align:start position:0% +I if I concretize that a little bit more +by mentioning a bit more about what I + + align:start position:0% +by mentioning a bit more about what I + + + align:start position:0% +by mentioning a bit more about what I +mean about the what I was implying or + + align:start position:0% +mean about the what I was implying or + + + align:start position:0% +mean about the what I was implying or +referring to when I spoke about that + + align:start position:0% +referring to when I spoke about that + + + align:start position:0% +referring to when I spoke about that +moment of imitation remember I said that + + align:start position:0% +moment of imitation remember I said that + + + align:start position:0% +moment of imitation remember I said that +there were essentially that the that the + + align:start position:0% +there were essentially that the that the + + + align:start position:0% +there were essentially that the that the +that silent film and incidentally I take + + align:start position:0% +that silent film and incidentally I take + + + align:start position:0% +that silent film and incidentally I take +it as a model for the way in which most + + align:start position:0% +it as a model for the way in which most + + + align:start position:0% +it as a model for the way in which most +New Media systems uh develop in culture + + align:start position:0% +New Media systems uh develop in culture + + + align:start position:0% +New Media systems uh develop in culture +you can apply this same basic schema to + + align:start position:0% +you can apply this same basic schema to + + + align:start position:0% +you can apply this same basic schema to +other forms of of popular entertainment + + align:start position:0% +other forms of of popular entertainment + + + align:start position:0% +other forms of of popular entertainment +including + + align:start position:0% +including + + + align:start position:0% +including +shocking as it may seem Shakespeare's + + align:start position:0% +shocking as it may seem Shakespeare's + + + align:start position:0% +shocking as it may seem Shakespeare's +public theater and I'll come back to the + + align:start position:0% +public theater and I'll come back to the + + + align:start position:0% +public theater and I'll come back to the +implications of that analogy the idea + + align:start position:0% +implications of that analogy the idea + + + align:start position:0% +implications of that analogy the idea +that Shakespeare was the movie of his + + align:start position:0% +that Shakespeare was the movie of his + + + align:start position:0% +that Shakespeare was the movie of his +time that Shakespeare's theater was the + + align:start position:0% +time that Shakespeare's theater was the + + + align:start position:0% +time that Shakespeare's theater was the +Hollywood studio system of of of the of + + align:start position:0% +Hollywood studio system of of of the of + + + align:start position:0% +Hollywood studio system of of of the of +the Elizabethan era is a very + + align:start position:0% +the Elizabethan era is a very + + + align:start position:0% +the Elizabethan era is a very +complicated one it's a very inspiring + + align:start position:0% +complicated one it's a very inspiring + + + align:start position:0% +complicated one it's a very inspiring +one and it's it's complicated because it + + align:start position:0% +one and it's it's complicated because it + + + align:start position:0% +one and it's it's complicated because it +makes us reassess our inherited Notions + + align:start position:0% +makes us reassess our inherited Notions + + + align:start position:0% +makes us reassess our inherited Notions +about what art is and where art comes + + align:start position:0% +about what art is and where art comes + + + align:start position:0% +about what art is and where art comes +from one of the subtexts in this course + + align:start position:0% +from one of the subtexts in this course + + + align:start position:0% +from one of the subtexts in this course +is precisely that the has to do with + + align:start position:0% +is precisely that the has to do with + + + align:start position:0% +is precisely that the has to do with +what I call the enabling conditions of + + align:start position:0% +what I call the enabling conditions of + + + align:start position:0% +what I call the enabling conditions of +Art and I'll come back to that again as + + align:start position:0% +Art and I'll come back to that again as + + + align:start position:0% +Art and I'll come back to that again as +a theme again and again in in the course + + align:start position:0% +a theme again and again in in the course + + + align:start position:0% +a theme again and again in in the course +so part of what I mean by the Fred art + + align:start position:0% +so part of what I mean by the Fred art + + + align:start position:0% +so part of what I mean by the Fred art +principle is this is this uh roing + + align:start position:0% +principle is this is this uh roing + + + align:start position:0% +principle is this is this uh roing +complex uh U um uh partly unpredictable + + align:start position:0% +complex uh U um uh partly unpredictable + + + align:start position:0% +complex uh U um uh partly unpredictable +process whereby uh a PO an enlarging + + align:start position:0% +process whereby uh a PO an enlarging + + + align:start position:0% +process whereby uh a PO an enlarging +population incredibly hungry for the + + align:start position:0% +population incredibly hungry for the + + + align:start position:0% +population incredibly hungry for the +Novelties being produced by this new + + align:start position:0% +Novelties being produced by this new + + + align:start position:0% +Novelties being produced by this new +technology create uh a kind of symbiotic + + align:start position:0% +technology create uh a kind of symbiotic + + + align:start position:0% +technology create uh a kind of symbiotic +relationship between the audience and + + align:start position:0% +relationship between the audience and + + + align:start position:0% +relationship between the audience and +the emerging medium so that as the + + align:start position:0% +the emerging medium so that as the + + + align:start position:0% +the emerging medium so that as the +medium be the medium grows more + + align:start position:0% +medium be the medium grows more + + + align:start position:0% +medium be the medium grows more +complicated in part because the audience + + align:start position:0% +complicated in part because the audience + + + align:start position:0% +complicated in part because the audience +okay after five or 10 or 15 visits to + + align:start position:0% +okay after five or 10 or 15 visits to + + + align:start position:0% +okay after five or 10 or 15 visits to +the to the Nickelodeon or uh or to the + + align:start position:0% +the to the Nickelodeon or uh or to the + + + align:start position:0% +the to the Nickelodeon or uh or to the +the after the movies moved out of after + + align:start position:0% +the after the movies moved out of after + + + align:start position:0% +the after the movies moved out of after +the movies moved out of the penny + + align:start position:0% +the movies moved out of the penny + + + align:start position:0% +the movies moved out of the penny +arcades and began to take their own + + align:start position:0% +arcades and began to take their own + + + align:start position:0% +arcades and began to take their own +space as some of you know and as as is + + align:start position:0% +space as some of you know and as as is + + + align:start position:0% +space as some of you know and as as is +recounted in our reading for this for + + align:start position:0% +recounted in our reading for this for + + + align:start position:0% +recounted in our reading for this for +these early weeks the movies first moved + + align:start position:0% +these early weeks the movies first moved + + + align:start position:0% +these early weeks the movies first moved +out into what were called Nickelodeon + + align:start position:0% +out into what were called Nickelodeon + + + align:start position:0% +out into what were called Nickelodeon +right they were they were uh storefronts + + align:start position:0% +right they were they were uh storefronts + + + align:start position:0% +right they were they were uh storefronts +in the for the most part in which + + align:start position:0% +in the for the most part in which + + + align:start position:0% +in the for the most part in which +mission was a nickel that's why they + + align:start position:0% +mission was a nickel that's why they + + + align:start position:0% +mission was a nickel that's why they +were called Nickelodeons uh and uh you + + align:start position:0% +were called Nickelodeons uh and uh you + + + align:start position:0% +were called Nickelodeons uh and uh you +sat in many of these on benches without + + align:start position:0% +sat in many of these on benches without + + + align:start position:0% +sat in many of these on benches without +backs next to strangers you didn't have + + align:start position:0% +backs next to strangers you didn't have + + + align:start position:0% +backs next to strangers you didn't have +private seats and you would sit in there + + align:start position:0% +private seats and you would sit in there + + + align:start position:0% +private seats and you would sit in there +and see a series of short films so but + + align:start position:0% +and see a series of short films so but + + + align:start position:0% +and see a series of short films so but +the fact that the Nickelodeons emerged + + align:start position:0% +the fact that the Nickelodeons emerged + + + align:start position:0% +the fact that the Nickelodeons emerged +so quickly is a mark of how popular an a + + align:start position:0% +so quickly is a mark of how popular an a + + + align:start position:0% +so quickly is a mark of how popular an a +film became even even in the even in its + + align:start position:0% +film became even even in the even in its + + + align:start position:0% +film became even even in the even in its +relatively primitive early form uh and + + align:start position:0% +relatively primitive early form uh and + + + align:start position:0% +relatively primitive early form uh and +and then of course within a few years of + + align:start position:0% +and then of course within a few years of + + + align:start position:0% +and then of course within a few years of +the Nickelodeon's appearing what else + + align:start position:0% +the Nickelodeon's appearing what else + + + align:start position:0% +the Nickelodeon's appearing what else +began to happen theaters made specially + + align:start position:0% +began to happen theaters made specially + + + align:start position:0% +began to happen theaters made specially +for the showing of motion pictures that + + align:start position:0% +for the showing of motion pictures that + + + align:start position:0% +for the showing of motion pictures that +were longer than the early shorts + + align:start position:0% +were longer than the early shorts + + + align:start position:0% +were longer than the early shorts +because film began to expand its length + + align:start position:0% +because film began to expand its length + + + align:start position:0% +because film began to expand its length +all through the period from 1910 through + + align:start position:0% +all through the period from 1910 through + + + align:start position:0% +all through the period from 1910 through +1920 right what what's the great moment + + align:start position:0% +1920 right what what's the great moment + + + align:start position:0% +1920 right what what's the great moment +when the feature film is born in the + + align:start position:0% +when the feature film is born in the + + + align:start position:0% +when the feature film is born in the +United States 1915 who's the director DW + + align:start position:0% +United States 1915 who's the director DW + + + align:start position:0% +United States 1915 who's the director DW +Griffith who's the what's the film Birth + + align:start position:0% +Griffith who's the what's the film Birth + + + align:start position:0% +Griffith who's the what's the film Birth +of a Nation Birth of a Nation a very + + align:start position:0% +of a Nation Birth of a Nation a very + + + align:start position:0% +of a Nation Birth of a Nation a very +complicated uh example because its + + align:start position:0% +complicated uh example because its + + + align:start position:0% +complicated uh example because its +content is disturbing in some ways it's + + align:start position:0% +content is disturbing in some ways it's + + + align:start position:0% +content is disturbing in some ways it's +a very reactionary and in some respects + + align:start position:0% +a very reactionary and in some respects + + + align:start position:0% +a very reactionary and in some respects +racist film it it it it it absorbs and + + align:start position:0% +racist film it it it it it absorbs and + + + align:start position:0% +racist film it it it it it absorbs and +Carries forward what we might think of + + align:start position:0% +Carries forward what we might think of + + + align:start position:0% +Carries forward what we might think of +as the the racial prejudices that were + + align:start position:0% +as the the racial prejudices that were + + + align:start position:0% +as the the racial prejudices that were +uh very widespread in American Society + + align:start position:0% +uh very widespread in American Society + + + align:start position:0% +uh very widespread in American Society +at the turn of the century and + + align:start position:0% +at the turn of the century and + + + align:start position:0% +at the turn of the century and +especially in the south from which + + align:start position:0% +especially in the south from which + + + align:start position:0% +especially in the south from which +Griffith himself was was a southerner + + align:start position:0% +Griffith himself was was a southerner + + + align:start position:0% +Griffith himself was was a southerner +and was born in the South and what his + + align:start position:0% +and was born in the South and what his + + + align:start position:0% +and was born in the South and what his +film was deeply influenced by a + + align:start position:0% +film was deeply influenced by a + + + align:start position:0% +film was deeply influenced by a +bestselling novel called the clansmen + + align:start position:0% +bestselling novel called the clansmen + + + align:start position:0% +bestselling novel called the clansmen +which was a celebration of the luux Clan + + align:start position:0% +which was a celebration of the luux Clan + + + align:start position:0% +which was a celebration of the luux Clan +uh and the uh Birth of a Nation so so + + align:start position:0% +uh and the uh Birth of a Nation so so + + + align:start position:0% +uh and the uh Birth of a Nation so so +the content of Birth of a Nation is very + + align:start position:0% +the content of Birth of a Nation is very + + + align:start position:0% +the content of Birth of a Nation is very +unsettling and disturbing and even when + + align:start position:0% +unsettling and disturbing and even when + + + align:start position:0% +unsettling and disturbing and even when +it was first uh um released to the + + align:start position:0% +it was first uh um released to the + + + align:start position:0% +it was first uh um released to the +public to great a claim because it it it + + align:start position:0% +public to great a claim because it it it + + + align:start position:0% +public to great a claim because it it it +it it expanded the possibilities of + + align:start position:0% +it it expanded the possibilities of + + + align:start position:0% +it it expanded the possibilities of +movies in all kinds of ways from a + + align:start position:0% +movies in all kinds of ways from a + + + align:start position:0% +movies in all kinds of ways from a +technical standpoint it is an + + align:start position:0% +technical standpoint it is an + + + align:start position:0% +technical standpoint it is an +astonishingly important film and from a + + align:start position:0% +astonishingly important film and from a + + + align:start position:0% +astonishingly important film and from a +Content standpoint it's a very + + align:start position:0% +Content standpoint it's a very + + + align:start position:0% +Content standpoint it's a very +disturbing film It's a Wonderful + + align:start position:0% +disturbing film It's a Wonderful + + + align:start position:0% +disturbing film It's a Wonderful +reminder of the fact that this progress + + align:start position:0% +reminder of the fact that this progress + + + align:start position:0% +reminder of the fact that this progress +I'm describing to you is not an + + align:start position:0% +I'm describing to you is not an + + + align:start position:0% +I'm describing to you is not an +unalloyed triumphal story story uh even + + align:start position:0% +unalloyed triumphal story story uh even + + + align:start position:0% +unalloyed triumphal story story uh even +as the movies became more technically + + align:start position:0% +as the movies became more technically + + + align:start position:0% +as the movies became more technically +complicated and and uh more demanding + + align:start position:0% +complicated and and uh more demanding + + + align:start position:0% +complicated and and uh more demanding +and longer and more interested in + + align:start position:0% +and longer and more interested in + + + align:start position:0% +and longer and more interested in +character they also nonetheless carried + + align:start position:0% +character they also nonetheless carried + + + align:start position:0% +character they also nonetheless carried +the lies and prejudices and and um um um + + align:start position:0% +the lies and prejudices and and um um um + + + align:start position:0% +the lies and prejudices and and um um um +hierarchic assumptions that were + + align:start position:0% +hierarchic assumptions that were + + + align:start position:0% +hierarchic assumptions that were +embedded in the society from which they + + align:start position:0% +embedded in the society from which they + + + align:start position:0% +embedded in the society from which they +arose how could it be otherwise every + + align:start position:0% +arose how could it be otherwise every + + + align:start position:0% +arose how could it be otherwise every +media form does this but it's but it's + + align:start position:0% +media form does this but it's but it's + + + align:start position:0% +media form does this but it's but it's +important to make this point as a way of + + align:start position:0% +important to make this point as a way of + + + align:start position:0% +important to make this point as a way of +reminding us that the story we're + + align:start position:0% +reminding us that the story we're + + + align:start position:0% +reminding us that the story we're +telling is not uh in some simple sense + + align:start position:0% +telling is not uh in some simple sense + + + align:start position:0% +telling is not uh in some simple sense +just a kind of a kind of progress myth + + align:start position:0% +just a kind of a kind of progress myth + + + align:start position:0% +just a kind of a kind of progress myth +in which we're celebrating development + + align:start position:0% +in which we're celebrating development + + + align:start position:0% +in which we're celebrating development +and and and genius we we're we're we're + + align:start position:0% +and and and genius we we're we're we're + + + align:start position:0% +and and and genius we we're we're we're +identifying and locating something more + + align:start position:0% +identifying and locating something more + + + align:start position:0% +identifying and locating something more +complicated than that the process + + align:start position:0% +complicated than that the process + + + align:start position:0% +complicated than that the process +whereby these cultural myths uh and + + align:start position:0% +whereby these cultural myths uh and + + + align:start position:0% +whereby these cultural myths uh and +these stories that are drawn from + + align:start position:0% +these stories that are drawn from + + + align:start position:0% +these stories that are drawn from +inherited older stories and from and + + align:start position:0% +inherited older stories and from and + + + align:start position:0% +inherited older stories and from and +from the lore of the society more + + align:start position:0% +from the lore of the society more + + + align:start position:0% +from the lore of the society more +broadly more generally uh uh are are + + align:start position:0% +broadly more generally uh uh are are + + + align:start position:0% +broadly more generally uh uh are are +transformed into this new medium and + + align:start position:0% +transformed into this new medium and + + + align:start position:0% +transformed into this new medium and +they have a tremendous technical + + align:start position:0% +they have a tremendous technical + + + align:start position:0% +they have a tremendous technical +interest but very often they also have a + + align:start position:0% +interest but very often they also have a + + + align:start position:0% +interest but very often they also have a +kind of cultural or sociological + + align:start position:0% +kind of cultural or sociological + + + align:start position:0% +kind of cultural or sociological +interest of a negative kind in the sense + + align:start position:0% +interest of a negative kind in the sense + + + align:start position:0% +interest of a negative kind in the sense +that what they reveal are the prejudices + + align:start position:0% +that what they reveal are the prejudices + + + align:start position:0% +that what they reveal are the prejudices +the lies the limitations uh of the + + align:start position:0% +the lies the limitations uh of the + + + align:start position:0% +the lies the limitations uh of the +society that's given the the mythologies + + align:start position:0% +society that's given the the mythologies + + + align:start position:0% +society that's given the the mythologies +that sustain the society again this is a + + align:start position:0% +that sustain the society again this is a + + + align:start position:0% +that sustain the society again this is a +matter to which we'll return one of the + + align:start position:0% +matter to which we'll return one of the + + + align:start position:0% +matter to which we'll return one of the +deep cultural functions of American + + align:start position:0% +deep cultural functions of American + + + align:start position:0% +deep cultural functions of American +movies especially was to promulgate a + + align:start position:0% +movies especially was to promulgate a + + + align:start position:0% +movies especially was to promulgate a +kind of Mythology of America and we'll + + align:start position:0% +kind of Mythology of America and we'll + + + align:start position:0% +kind of Mythology of America and we'll +talk more about this when we when we + + align:start position:0% +talk more about this when we when we + + + align:start position:0% +talk more about this when we when we +when we reach certain genre forms in the + + align:start position:0% +when we reach certain genre forms in the + + + align:start position:0% +when we reach certain genre forms in the +second segment of the course + + align:start position:0% +second segment of the course + + + align:start position:0% +second segment of the course +I said something earlier this morning + + align:start position:0% +I said something earlier this morning + + + align:start position:0% +I said something earlier this morning +that I want to make uh + + align:start position:0% +that I want to make uh + + + align:start position:0% +that I want to make uh +explicit uh because I think it's an + + align:start position:0% +explicit uh because I think it's an + + + align:start position:0% +explicit uh because I think it's an +important another way of qualifying this + + align:start position:0% +important another way of qualifying this + + + align:start position:0% +important another way of qualifying this +triumphal story it's hard because I'm + + align:start position:0% +triumphal story it's hard because I'm + + + align:start position:0% +triumphal story it's hard because I'm +enthusiastic about what I'm looking at + + align:start position:0% +enthusiastic about what I'm looking at + + + align:start position:0% +enthusiastic about what I'm looking at +and there is some material That's so + + align:start position:0% +and there is some material That's so + + + align:start position:0% +and there is some material That's so +exciting here to watch in a way what + + align:start position:0% +exciting here to watch in a way what + + + align:start position:0% +exciting here to watch in a way what +we're watching is we're watching the + + align:start position:0% +we're watching is we're watching the + + + align:start position:0% +we're watching is we're watching the +birth of the movies we're watching the + + align:start position:0% +birth of the movies we're watching the + + + align:start position:0% +birth of the movies we're watching the +the the discovery of the language of + + align:start position:0% +the the discovery of the language of + + + align:start position:0% +the the discovery of the language of +Cinema in these early films and that's + + align:start position:0% +Cinema in these early films and that's + + + align:start position:0% +Cinema in these early films and that's +why even though from an artistic + + align:start position:0% +why even though from an artistic + + + align:start position:0% +why even though from an artistic +standpoint some of these shorts are not + + align:start position:0% +standpoint some of these shorts are not + + + align:start position:0% +standpoint some of these shorts are not +very rich I hope they're interesting + + align:start position:0% +very rich I hope they're interesting + + + align:start position:0% +very rich I hope they're interesting +enough that I've made them interesting + + align:start position:0% +enough that I've made them interesting + + + align:start position:0% +enough that I've made them interesting +to you from a historical standpoint if + + align:start position:0% +to you from a historical standpoint if + + + align:start position:0% +to you from a historical standpoint if +you look at them closely you can see you + + align:start position:0% +you look at them closely you can see you + + + align:start position:0% +you look at them closely you can see you +can see the movies being born you can + + align:start position:0% +can see the movies being born you can + + + align:start position:0% +can see the movies being born you can +see a language a Syntax for speaking in + + align:start position:0% +see a language a Syntax for speaking in + + + align:start position:0% +see a language a Syntax for speaking in +pictures for for this new new visual + + align:start position:0% +pictures for for this new new visual + + + align:start position:0% +pictures for for this new new visual +language being this new visual medium + + align:start position:0% +language being this new visual medium + + + align:start position:0% +language being this new visual medium +being developed uh and and I I'll if I + + align:start position:0% +being developed uh and and I I'll if I + + + align:start position:0% +being developed uh and and I I'll if I +have time this evening I'll give you a + + align:start position:0% +have time this evening I'll give you a + + + align:start position:0% +have time this evening I'll give you a +few more concrete examples of that but + + align:start position:0% +few more concrete examples of that but + + + align:start position:0% +few more concrete examples of that but +another way in which one can qualify + + align:start position:0% +another way in which one can qualify + + + align:start position:0% +another way in which one can qualify +this apparently triumphal story it's not + + align:start position:0% +this apparently triumphal story it's not + + + align:start position:0% +this apparently triumphal story it's not +a triumphal story even though it is a + + align:start position:0% +a triumphal story even though it is a + + + align:start position:0% +a triumphal story even though it is a +story of refinement development and + + align:start position:0% +story of refinement development and + + + align:start position:0% +story of refinement development and +evolution of a of a kind that involves + + align:start position:0% +evolution of a of a kind that involves + + + align:start position:0% +evolution of a of a kind that involves +increasing complexity and Technical + + align:start position:0% +increasing complexity and Technical + + + align:start position:0% +increasing complexity and Technical +Perfection technical uh uh Mastery uh + + align:start position:0% +Perfection technical uh uh Mastery uh + + + align:start position:0% +Perfection technical uh uh Mastery uh +it's not merely that or not or not or + + align:start position:0% +it's not merely that or not or not or + + + align:start position:0% +it's not merely that or not or not or +not even primarily that it's very + + align:start position:0% +not even primarily that it's very + + + align:start position:0% +not even primarily that it's very +important to recognize among other + + align:start position:0% +important to recognize among other + + + align:start position:0% +important to recognize among other +things as I implied this afternoon that + + align:start position:0% +things as I implied this afternoon that + + + align:start position:0% +things as I implied this afternoon that +uh not all the possibilities that are + + align:start position:0% +uh not all the possibilities that are + + + align:start position:0% +uh not all the possibilities that are +inherent in the in the in the nent + + align:start position:0% +inherent in the in the in the nent + + + align:start position:0% +inherent in the in the in the nent +medium AR necessarily exploited in a + + align:start position:0% +medium AR necessarily exploited in a + + + align:start position:0% +medium AR necessarily exploited in a +particular cultural moment or + + align:start position:0% +particular cultural moment or + + + align:start position:0% +particular cultural moment or +or maybe ever exploited depending on how + + align:start position:0% +or maybe ever exploited depending on how + + + align:start position:0% +or maybe ever exploited depending on how +things develop that is to say uh I + + align:start position:0% +things develop that is to say uh I + + + align:start position:0% +things develop that is to say uh I +mentioned this this afternoon uh how for + + align:start position:0% +mentioned this this afternoon uh how for + + + align:start position:0% +mentioned this this afternoon uh how for +instance when Edison first conceived the + + align:start position:0% +instance when Edison first conceived the + + + align:start position:0% +instance when Edison first conceived the +apparatus before it was actually + + align:start position:0% +apparatus before it was actually + + + align:start position:0% +apparatus before it was actually +invented of the mo of the motion picture + + align:start position:0% +invented of the mo of the motion picture + + + align:start position:0% +invented of the mo of the motion picture +projector and the motion picture camera + + align:start position:0% +projector and the motion picture camera + + + align:start position:0% +projector and the motion picture camera +his first idea was that he would create + + align:start position:0% +his first idea was that he would create + + + align:start position:0% +his first idea was that he would create +an an item that would be a consumer what + + align:start position:0% +an an item that would be a consumer what + + + align:start position:0% +an an item that would be a consumer what +we would today call a consumer item that + + align:start position:0% +we would today call a consumer item that + + + align:start position:0% +we would today call a consumer item that +would be sold to individual families and + + align:start position:0% +would be sold to individual families and + + + align:start position:0% +would be sold to individual families and +the film would become you know the an + + align:start position:0% +the film would become you know the an + + + align:start position:0% +the film would become you know the an +equivalent of a kind of a photo album + + align:start position:0% +equivalent of a kind of a photo album + + + align:start position:0% +equivalent of a kind of a photo album +although it would it would have Motion + + align:start position:0% +although it would it would have Motion + + + align:start position:0% +although it would it would have Motion +in it and and and as I suggested this + + align:start position:0% +in it and and and as I suggested this + + + align:start position:0% +in it and and and as I suggested this +this morning this afternoon there's no + + align:start position:0% +this morning this afternoon there's no + + + align:start position:0% +this morning this afternoon there's no +reason why given the nature of the + + align:start position:0% +reason why given the nature of the + + + align:start position:0% +reason why given the nature of the +technology itself that that vision of + + align:start position:0% +technology itself that that vision of + + + align:start position:0% +technology itself that that vision of +how film might develop was impossible in + + align:start position:0% +how film might develop was impossible in + + + align:start position:0% +how film might develop was impossible in +fact it wasn't impossible it was just + + align:start position:0% +fact it wasn't impossible it was just + + + align:start position:0% +fact it wasn't impossible it was just +incredibly ahead of its time it took it + + align:start position:0% +incredibly ahead of its time it took it + + + align:start position:0% +incredibly ahead of its time it took it +took half a century before something + + align:start position:0% +took half a century before something + + + align:start position:0% +took half a century before something +like that actually became available in + + align:start position:0% +like that actually became available in + + + align:start position:0% +like that actually became available in +society but there was no reason in terms + + align:start position:0% +society but there was no reason in terms + + + align:start position:0% +society but there was no reason in terms +of the the possibilities of the + + align:start position:0% +of the the possibilities of the + + + align:start position:0% +of the the possibilities of the +technology that that that that needed to + + align:start position:0% +technology that that that that needed to + + + align:start position:0% +technology that that that that needed to +happen what I'm calling your attention + + align:start position:0% +happen what I'm calling your attention + + + align:start position:0% +happen what I'm calling your attention +to is what is a very widespread myth + + align:start position:0% +to is what is a very widespread myth + + + align:start position:0% +to is what is a very widespread myth +it's especially pernicious and + + align:start position:0% +it's especially pernicious and + + + align:start position:0% +it's especially pernicious and +widespread at MIT and it's very for + + align:start position:0% +widespread at MIT and it's very for + + + align:start position:0% +widespread at MIT and it's very for +reasons that are obvious and + + align:start position:0% +reasons that are obvious and + + + align:start position:0% +reasons that are obvious and +understandable we at MIT love to believe + + align:start position:0% +understandable we at MIT love to believe + + + align:start position:0% +understandable we at MIT love to believe +that technology will solve all problems + + align:start position:0% +that technology will solve all problems + + + align:start position:0% +that technology will solve all problems +the truth of the matter is technology + + align:start position:0% +the truth of the matter is technology + + + align:start position:0% +the truth of the matter is technology +doesn't solve problems uh it it it + + align:start position:0% +doesn't solve problems uh it it it + + + align:start position:0% +doesn't solve problems uh it it it +solves some problems but it creates an + + align:start position:0% +solves some problems but it creates an + + + align:start position:0% +solves some problems but it creates an +equal number of new problems at a + + align:start position:0% +equal number of new problems at a + + + align:start position:0% +equal number of new problems at a +minimum the the fact of the matter is + + align:start position:0% +minimum the the fact of the matter is + + + align:start position:0% +minimum the the fact of the matter is +that when that that that uh it is not + + align:start position:0% +that when that that that uh it is not + + + align:start position:0% +that when that that that uh it is not +merely the case that that uh technology + + align:start position:0% +merely the case that that uh technology + + + align:start position:0% +merely the case that that uh technology +by itself is never a solution to any + + align:start position:0% +by itself is never a solution to any + + + align:start position:0% +by itself is never a solution to any +social or political problem even though + + align:start position:0% +social or political problem even though + + + align:start position:0% +social or political problem even though +it may have a may be a potential + + align:start position:0% +it may have a may be a potential + + + align:start position:0% +it may have a may be a potential +instrument for certain kinds of social + + align:start position:0% +instrument for certain kinds of social + + + align:start position:0% +instrument for certain kinds of social +or or or or or or or political outcomes + + align:start position:0% +or or or or or or or political outcomes + + + align:start position:0% +or or or or or or or political outcomes +but only a potential one the technology + + align:start position:0% +but only a potential one the technology + + + align:start position:0% +but only a potential one the technology +will always all new technologies will + + align:start position:0% +will always all new technologies will + + + align:start position:0% +will always all new technologies will +contain latencies possibilities that are + + align:start position:0% +contain latencies possibilities that are + + + align:start position:0% +contain latencies possibilities that are +not exploited uh roads not taken by the + + align:start position:0% +not exploited uh roads not taken by the + + + align:start position:0% +not exploited uh roads not taken by the +technology and we we have some very + + align:start position:0% +technology and we we have some very + + + align:start position:0% +technology and we we have some very +interesting alternative possibilities + + align:start position:0% +interesting alternative possibilities + + + align:start position:0% +interesting alternative possibilities +I'll give you one really scary one think + + align:start position:0% +I'll give you one really scary one think + + + align:start position:0% +I'll give you one really scary one think +about the way a movie is actually + + align:start position:0% +about the way a movie is actually + + + align:start position:0% +about the way a movie is actually +developed in the United States that + + align:start position:0% +developed in the United States that + + + align:start position:0% +developed in the United States that +basic that basic pattern with certain + + align:start position:0% +basic that basic pattern with certain + + + align:start position:0% +basic that basic pattern with certain +significant variations held pretty much + + align:start position:0% +significant variations held pretty much + + + align:start position:0% +significant variations held pretty much +in in other societies as well even in an + + align:start position:0% +in in other societies as well even in an + + + align:start position:0% +in in other societies as well even in an +odd way in societies where the + + align:start position:0% +odd way in societies where the + + + align:start position:0% +odd way in societies where the +production process was controlled more + + align:start position:0% +production process was controlled more + + + align:start position:0% +production process was controlled more +by government than it was by private + + align:start position:0% +by government than it was by private + + + align:start position:0% +by government than it was by private +Enterprise there was still a system in + + align:start position:0% +Enterprise there was still a system in + + + align:start position:0% +Enterprise there was still a system in +which audiences who were amateurs would + + align:start position:0% +which audiences who were amateurs would + + + align:start position:0% +which audiences who were amateurs would +go to a theater collect in the theater + + align:start position:0% +go to a theater collect in the theater + + + align:start position:0% +go to a theater collect in the theater +to watch a product that was made by + + align:start position:0% +to watch a product that was made by + + + align:start position:0% +to watch a product that was made by +profession by a professional Elite and + + align:start position:0% +profession by a professional Elite and + + + align:start position:0% +profession by a professional Elite and +again there's nothing in the technology + + align:start position:0% +again there's nothing in the technology + + + align:start position:0% +again there's nothing in the technology +that requires that right well what + + align:start position:0% +that requires that right well what + + + align:start position:0% +that requires that right well what +explains what explains it are the + + align:start position:0% +explains what explains it are the + + + align:start position:0% +explains what explains it are the +economic demographic social + + align:start position:0% +economic demographic social + + + align:start position:0% +economic demographic social +circumstances of the society at the + + align:start position:0% +circumstances of the society at the + + + align:start position:0% +circumstances of the society at the +moment when that technology became + + align:start position:0% +moment when that technology became + + + align:start position:0% +moment when that technology became +partly viable so the choices that are + + align:start position:0% +partly viable so the choices that are + + + align:start position:0% +partly viable so the choices that are +made are for how a technology will be + + align:start position:0% +made are for how a technology will be + + + align:start position:0% +made are for how a technology will be +used are always narrowing ones you all + + align:start position:0% +used are always narrowing ones you all + + + align:start position:0% +used are always narrowing ones you all +have have experience with this with w w + + align:start position:0% +have have experience with this with w w + + + align:start position:0% +have have experience with this with w w +w with with this process think of it + + align:start position:0% +w with with this process think of it + + + align:start position:0% +w with with this process think of it +think of for example the way cell phones + + align:start position:0% +think of for example the way cell phones + + + align:start position:0% +think of for example the way cell phones +have changed and the way uh and the or + + align:start position:0% +have changed and the way uh and the or + + + align:start position:0% +have changed and the way uh and the or +in fact in your it's an interesting + + align:start position:0% +in fact in your it's an interesting + + + align:start position:0% +in fact in your it's an interesting +thing because in your all of you have + + align:start position:0% +thing because in your all of you have + + + align:start position:0% +thing because in your all of you have +been alive in the period when cell + + align:start position:0% +been alive in the period when cell + + + align:start position:0% +been alive in the period when cell +phones essentially came into society and + + align:start position:0% +phones essentially came into society and + + + align:start position:0% +phones essentially came into society and +were elaborated but is there anyone here + + align:start position:0% +were elaborated but is there anyone here + + + align:start position:0% +were elaborated but is there anyone here +who can remember a time cannot remember + + align:start position:0% +who can remember a time cannot remember + + + align:start position:0% +who can remember a time cannot remember +a time before cell phones see all of you + + align:start position:0% +a time before cell phones see all of you + + + align:start position:0% +a time before cell phones see all of you +remember that right well you can think + + align:start position:0% +remember that right well you can think + + + align:start position:0% +remember that right well you can think +of what happened to the you can think of + + align:start position:0% +of what happened to the you can think of + + + align:start position:0% +of what happened to the you can think of +the elaboration and and the the + + align:start position:0% +the elaboration and and the the + + + align:start position:0% +the elaboration and and the the +development of cell phones as a as a as + + align:start position:0% +development of cell phones as a as a as + + + align:start position:0% +development of cell phones as a as a as +a kind of in some sense perverse model + + align:start position:0% +a kind of in some sense perverse model + + + align:start position:0% +a kind of in some sense perverse model +for what I'm talking about I say + + align:start position:0% +for what I'm talking about I say + + + align:start position:0% +for what I'm talking about I say +perverse because you can see how + + align:start position:0% +perverse because you can see how + + + align:start position:0% +perverse because you can see how +counterproductive in many ways some of + + align:start position:0% +counterproductive in many ways some of + + + align:start position:0% +counterproductive in many ways some of +the technological add-ons that are being + + align:start position:0% +the technological add-ons that are being + + + align:start position:0% +the technological add-ons that are being +created for cell phones are it's as if + + align:start position:0% +created for cell phones are it's as if + + + align:start position:0% +created for cell phones are it's as if +the industry in so far as it's a single + + align:start position:0% +the industry in so far as it's a single + + + align:start position:0% +the industry in so far as it's a single +industry can't exactly figure out what + + align:start position:0% +industry can't exactly figure out what + + + align:start position:0% +industry can't exactly figure out what +to do because the audience for the what + + align:start position:0% +to do because the audience for the what + + + align:start position:0% +to do because the audience for the what +the what we call the cell phone is such + + align:start position:0% +the what we call the cell phone is such + + + align:start position:0% +the what we call the cell phone is such +a diverse one and you know uh illiterate + + align:start position:0% +a diverse one and you know uh illiterate + + + align:start position:0% +a diverse one and you know uh illiterate +teenagers love to text message right so + + align:start position:0% +teenagers love to text message right so + + + align:start position:0% +teenagers love to text message right so +so you know even though it's not in in + + align:start position:0% +so you know even though it's not in in + + + align:start position:0% +so you know even though it's not in in +the English language anymore you can see + + align:start position:0% +the English language anymore you can see + + + align:start position:0% +the English language anymore you can see +and you can see the cell phone companies + + align:start position:0% +and you can see the cell phone companies + + + align:start position:0% +and you can see the cell phone companies +trying to teach the population how to + + align:start position:0% +trying to teach the population how to + + + align:start position:0% +trying to teach the population how to +how to speak in text message right in + + align:start position:0% +how to speak in text message right in + + + align:start position:0% +how to speak in text message right in +text M mesga or whatever you would say + + align:start position:0% +text M mesga or whatever you would say + + + align:start position:0% +text M mesga or whatever you would say +right have you ever seen the uh the + + align:start position:0% +right have you ever seen the uh the + + + align:start position:0% +right have you ever seen the uh the +stupid ad in which you see the old + + align:start position:0% +stupid ad in which you see the old + + + align:start position:0% +stupid ad in which you see the old +grandmother trying to say uh uh what did + + align:start position:0% +grandmother trying to say uh uh what did + + + align:start position:0% +grandmother trying to say uh uh what did +she say what she says mind your own + + align:start position:0% +she say what she says mind your own + + + align:start position:0% +she say what she says mind your own +business in texe what would she my yob B + + align:start position:0% +business in texe what would she my yob B + + + align:start position:0% +business in texe what would she my yob B +she says to her daughter as if + + align:start position:0% +she says to her daughter as if + + + align:start position:0% +she says to her daughter as if +grandmothers are going to begin to start + + align:start position:0% +grandmothers are going to begin to start + + + align:start position:0% +grandmothers are going to begin to start +texting uh I mean and the and of course + + align:start position:0% +texting uh I mean and the and of course + + + align:start position:0% +texting uh I mean and the and of course +if you think about it if you think about + + align:start position:0% +if you think about it if you think about + + + align:start position:0% +if you think about it if you think about +it from a technological standpoint it's + + align:start position:0% +it from a technological standpoint it's + + + align:start position:0% +it from a technological standpoint it's +actually a very inefficient use of the + + align:start position:0% +actually a very inefficient use of the + + + align:start position:0% +actually a very inefficient use of the +medium isn't it think how hard it is to + + align:start position:0% +medium isn't it think how hard it is to + + + align:start position:0% +medium isn't it think how hard it is to +type to type uh uh messages of any kind + + align:start position:0% +type to type uh uh messages of any kind + + + align:start position:0% +type to type uh uh messages of any kind +on cell phones what what what inadequate + + align:start position:0% +on cell phones what what what inadequate + + + align:start position:0% +on cell phones what what what inadequate +what inadequate uh uh environments they + + align:start position:0% +what inadequate uh uh environments they + + + align:start position:0% +what inadequate uh uh environments they +are for that and what one could say is + + align:start position:0% +are for that and what one could say is + + + align:start position:0% +are for that and what one could say is +that certain kinds of decisions are + + align:start position:0% +that certain kinds of decisions are + + + align:start position:0% +that certain kinds of decisions are +being made uh that don't really have to + + align:start position:0% +being made uh that don't really have to + + + align:start position:0% +being made uh that don't really have to +do with with uh uh the the uses to which + + align:start position:0% +do with with uh uh the the uses to which + + + align:start position:0% +do with with uh uh the the uses to which +you might put this tiny little device + + align:start position:0% +you might put this tiny little device + + + align:start position:0% +you might put this tiny little device +but have to do with the fact that there + + align:start position:0% +but have to do with the fact that there + + + align:start position:0% +but have to do with the fact that there +are so many latent possibilities in the + + align:start position:0% +are so many latent possibilities in the + + + align:start position:0% +are so many latent possibilities in the +digital technology that people are play + + align:start position:0% +digital technology that people are play + + + align:start position:0% +digital technology that people are play +playing that that that we're trying that + + align:start position:0% +playing that that that we're trying that + + + align:start position:0% +playing that that that we're trying that +that manufacturers are trying out a + + align:start position:0% +that manufacturers are trying out a + + + align:start position:0% +that manufacturers are trying out a +whole range of things some of which will + + align:start position:0% +whole range of things some of which will + + + align:start position:0% +whole range of things some of which will +definitely Fall by the wayside will be + + align:start position:0% +definitely Fall by the wayside will be + + + align:start position:0% +definitely Fall by the wayside will be +will disappear uh and in fact some I + + align:start position:0% +will disappear uh and in fact some I + + + align:start position:0% +will disappear uh and in fact some I +guess many of you may not know this but + + align:start position:0% +guess many of you may not know this but + + + align:start position:0% +guess many of you may not know this but +uh in the 1930s uh the American AT&T + + align:start position:0% +uh in the 1930s uh the American AT&T + + + align:start position:0% +uh in the 1930s uh the American AT&T +which then was the main Telephone + + align:start position:0% +which then was the main Telephone + + + align:start position:0% +which then was the main Telephone +Company in the society um uh decided + + align:start position:0% +Company in the society um uh decided + + + align:start position:0% +Company in the society um uh decided +that of course what what was needed more + + align:start position:0% +that of course what what was needed more + + + align:start position:0% +that of course what what was needed more +than anything else was a picture phone + + align:start position:0% +than anything else was a picture phone + + + align:start position:0% +than anything else was a picture phone +and they invested millions and millions + + align:start position:0% +and they invested millions and millions + + + align:start position:0% +and they invested millions and millions +of dollars in something called a picture + + align:start position:0% +of dollars in something called a picture + + + align:start position:0% +of dollars in something called a picture +phone and they tried to Market it there + + align:start position:0% +phone and they tried to Market it there + + + align:start position:0% +phone and they tried to Market it there +were elaborate marketing campaigns it + + align:start position:0% +were elaborate marketing campaigns it + + + align:start position:0% +were elaborate marketing campaigns it +didn't occur to them that you know when + + align:start position:0% +didn't occur to them that you know when + + + align:start position:0% +didn't occur to them that you know when +people are on the telephone they often + + align:start position:0% +people are on the telephone they often + + + align:start position:0% +people are on the telephone they often +don't want to be seen right and but it + + align:start position:0% +don't want to be seen right and but it + + + align:start position:0% +don't want to be seen right and but it +was because it was technologically + + align:start position:0% +was because it was technologically + + + align:start position:0% +was because it was technologically +possible to create a telephone that + + align:start position:0% +possible to create a telephone that + + + align:start position:0% +possible to create a telephone that +showed a person's + + align:start position:0% +showed a person's + + + align:start position:0% +showed a person's +features when they remember this was a + + align:start position:0% +features when they remember this was a + + + align:start position:0% +features when they remember this was a +time when all phones were Tethered to a + + align:start position:0% +time when all phones were Tethered to a + + + align:start position:0% +time when all phones were Tethered to a +line so you couldn't walk around and + + align:start position:0% +line so you couldn't walk around and + + + align:start position:0% +line so you couldn't walk around and +take pictures outside the the camera in + + align:start position:0% +take pictures outside the the camera in + + + align:start position:0% +take pictures outside the the camera in +the cell phone is a more interesting + + align:start position:0% +the cell phone is a more interesting + + + align:start position:0% +the cell phone is a more interesting +device because the cell phone itself is + + align:start position:0% +device because the cell phone itself is + + + align:start position:0% +device because the cell phone itself is +portable and it allows you to do certain + + align:start position:0% +portable and it allows you to do certain + + + align:start position:0% +portable and it allows you to do certain +kinds of certain kinds of things what + + align:start position:0% +kinds of certain kinds of things what + + + align:start position:0% +kinds of certain kinds of things what +and in fact the uses to which the cell + + align:start position:0% +and in fact the uses to which the cell + + + align:start position:0% +and in fact the uses to which the cell +phone camera is being put certainly are + + align:start position:0% +phone camera is being put certainly are + + + align:start position:0% +phone camera is being put certainly are +much more complicated now than they were + + align:start position:0% +much more complicated now than they were + + + align:start position:0% +much more complicated now than they were +when the people who who decided to put + + align:start position:0% +when the people who who decided to put + + + align:start position:0% +when the people who who decided to put +cameras in cell phones could have + + align:start position:0% +cameras in cell phones could have + + + align:start position:0% +cameras in cell phones could have +imagined right it's an example of how + + align:start position:0% +imagined right it's an example of how + + + align:start position:0% +imagined right it's an example of how +the audience begins to take the new + + align:start position:0% +the audience begins to take the new + + + align:start position:0% +the audience begins to take the new +technology and find new uses for uh uh + + align:start position:0% +technology and find new uses for uh uh + + + align:start position:0% +technology and find new uses for uh uh +uh possibilities that are embedded in + + align:start position:0% +uh possibilities that are embedded in + + + align:start position:0% +uh possibilities that are embedded in +the in the technology but to come back + + align:start position:0% +the in the technology but to come back + + + align:start position:0% +the in the technology but to come back +to the primary point the primary point + + align:start position:0% +to the primary point the primary point + + + align:start position:0% +to the primary point the primary point +is that is that every technology will + + align:start position:0% +is that is that every technology will + + + align:start position:0% +is that is that every technology will +have latent possibilities that are that + + align:start position:0% +have latent possibilities that are that + + + align:start position:0% +have latent possibilities that are that +are not exploited and the reasons that + + align:start position:0% +are not exploited and the reasons that + + + align:start position:0% +are not exploited and the reasons that +they're not exploited do not necessarily + + align:start position:0% +they're not exploited do not necessarily + + + align:start position:0% +they're not exploited do not necessarily +have to do with with uh uh intellectual + + align:start position:0% +have to do with with uh uh intellectual + + + align:start position:0% +have to do with with uh uh intellectual +or artistic questions or or or the best + + align:start position:0% +or artistic questions or or or the best + + + align:start position:0% +or artistic questions or or or the best +way to deploy this technology for the + + align:start position:0% +way to deploy this technology for the + + + align:start position:0% +way to deploy this technology for the +social good the reasons have to do with + + align:start position:0% +social good the reasons have to do with + + + align:start position:0% +social good the reasons have to do with +Market possibilities the American Market + + align:start position:0% +Market possibilities the American Market + + + align:start position:0% +Market possibilities the American Market +is so diverse that one of the things + + align:start position:0% +is so diverse that one of the things + + + align:start position:0% +is so diverse that one of the things +that encourages is an immense amount of + + align:start position:0% +that encourages is an immense amount of + + + align:start position:0% +that encourages is an immense amount of +duplication overlap and unnecessary + + align:start position:0% +duplication overlap and unnecessary + + + align:start position:0% +duplication overlap and unnecessary +competition in which different + + align:start position:0% +competition in which different + + + align:start position:0% +competition in which different +Technologies which perform the same + + align:start position:0% +Technologies which perform the same + + + align:start position:0% +Technologies which perform the same +function are at war with each other all + + align:start position:0% +function are at war with each other all + + + align:start position:0% +function are at war with each other all +the time we now have a new one having to + + align:start position:0% +the time we now have a new one having to + + + align:start position:0% +the time we now have a new one having to +do with the with the High defition + + align:start position:0% +do with the with the High defition + + + align:start position:0% +do with the with the High defition +movies and television right there are + + align:start position:0% +movies and television right there are + + + align:start position:0% +movies and television right there are +competing systems right that now the + + align:start position:0% +competing systems right that now the + + + align:start position:0% +competing systems right that now the +reason there are competing systems + + align:start position:0% +reason there are competing systems + + + align:start position:0% +reason there are competing systems +doesn't have to do with what's best for + + align:start position:0% +doesn't have to do with what's best for + + + align:start position:0% +doesn't have to do with what's best for +the consumer uh it has to do it has to + + align:start position:0% +the consumer uh it has to do it has to + + + align:start position:0% +the consumer uh it has to do it has to +do with the fact of of market and so so + + align:start position:0% +do with the fact of of market and so so + + + align:start position:0% +do with the fact of of market and so so +one of the things I'm suggesting to you + + align:start position:0% +one of the things I'm suggesting to you + + + align:start position:0% +one of the things I'm suggesting to you +what what the primary thing I'm + + align:start position:0% +what what the primary thing I'm + + + align:start position:0% +what what the primary thing I'm +suggesting to is that the evolution of + + align:start position:0% +suggesting to is that the evolution of + + + align:start position:0% +suggesting to is that the evolution of +the movies that I want you to be aware + + align:start position:0% +the movies that I want you to be aware + + + align:start position:0% +the movies that I want you to be aware +of this process of increasing complexity + + align:start position:0% +of this process of increasing complexity + + + align:start position:0% +of this process of increasing complexity +and and uh uh uh compression in which in + + align:start position:0% +and and uh uh uh compression in which in + + + align:start position:0% +and and uh uh uh compression in which in +in which the movies become a more and + + align:start position:0% +in which the movies become a more and + + + align:start position:0% +in which the movies become a more and +more independent form of expression in + + align:start position:0% +more independent form of expression in + + + align:start position:0% +more independent form of expression in +which the movies begin to discover the + + align:start position:0% +which the movies begin to discover the + + + align:start position:0% +which the movies begin to discover the +unique characteristics of the motion + + align:start position:0% +unique characteristics of the motion + + + align:start position:0% +unique characteristics of the motion +picture camera and of the environment of + + align:start position:0% +picture camera and of the environment of + + + align:start position:0% +picture camera and of the environment of +the movie theater that that the movie + + align:start position:0% +the movie theater that that the movie + + + align:start position:0% +the movie theater that that the movie +that the movies begin to explore those + + align:start position:0% +that the movies begin to explore those + + + align:start position:0% +that the movies begin to explore those +qualities in this new medium that are + + align:start position:0% +qualities in this new medium that are + + + align:start position:0% +qualities in this new medium that are +unique and special that process is + + align:start position:0% +unique and special that process is + + + align:start position:0% +unique and special that process is +important and I want you to be aware of + + align:start position:0% +important and I want you to be aware of + + + align:start position:0% +important and I want you to be aware of +it but I don't want you to embrace that + + align:start position:0% +it but I don't want you to embrace that + + + align:start position:0% +it but I don't want you to embrace that +principle too uncritically because I + + align:start position:0% +principle too uncritically because I + + + align:start position:0% +principle too uncritically because I +want you to recognize that what that + + align:start position:0% +want you to recognize that what that + + + align:start position:0% +want you to recognize that what that +that the technology itself does not + + align:start position:0% +that the technology itself does not + + + align:start position:0% +that the technology itself does not +explain this process the process is + + align:start position:0% +explain this process the process is + + + align:start position:0% +explain this process the process is +explained by cultural factors and social + + align:start position:0% +explained by cultural factors and social + + + align:start position:0% +explained by cultural factors and social +factors and even individual uh sometimes + + align:start position:0% +factors and even individual uh sometimes + + + align:start position:0% +factors and even individual uh sometimes +individual psychological factors right + + align:start position:0% +individual psychological factors right + + + align:start position:0% +individual psychological factors right +uh what we're talking about here is the + + align:start position:0% +uh what we're talking about here is the + + + align:start position:0% +uh what we're talking about here is the +myth of technological determinism the + + align:start position:0% +myth of technological determinism the + + + align:start position:0% +myth of technological determinism the +myth that technology drives culture the + + align:start position:0% +myth that technology drives culture the + + + align:start position:0% +myth that technology drives culture the +myth that the new invention obliterates + + align:start position:0% +myth that the new invention obliterates + + + align:start position:0% +myth that the new invention obliterates +old inventions the truth is much more + + align:start position:0% +old inventions the truth is much more + + + align:start position:0% +old inventions the truth is much more +complicated than that in fact even when + + align:start position:0% +complicated than that in fact even when + + + align:start position:0% +complicated than that in fact even when +new technologies come into a society and + + align:start position:0% +new technologies come into a society and + + + align:start position:0% +new technologies come into a society and +are successfully embedded in the social + + align:start position:0% +are successfully embedded in the social + + + align:start position:0% +are successfully embedded in the social +practices of a society very different + + align:start position:0% +practices of a society very different + + + align:start position:0% +practices of a society very different +from the new technology becoming + + align:start position:0% +from the new technology becoming + + + align:start position:0% +from the new technology becoming +available right and you can all think in + + align:start position:0% +available right and you can all think in + + + align:start position:0% +available right and you can all think in +your own lifetimes of certain + + align:start position:0% +your own lifetimes of certain + + + align:start position:0% +your own lifetimes of certain +technologies that are no longer around + + align:start position:0% +technologies that are no longer around + + + align:start position:0% +technologies that are no longer around +uh uh eight do you any of you remember + + align:start position:0% +uh uh eight do you any of you remember + + + align:start position:0% +uh uh eight do you any of you remember +uh eight track tapes that used they used + + align:start position:0% +uh eight track tapes that used they used + + + align:start position:0% +uh eight track tapes that used they used +to have in cars some of you are nodding + + align:start position:0% +to have in cars some of you are nodding + + + align:start position:0% +to have in cars some of you are nodding +right you can't find them anymore but in + + align:start position:0% +right you can't find them anymore but in + + + align:start position:0% +right you can't find them anymore but in +fact think think about what's happened + + align:start position:0% +fact think think about what's happened + + + align:start position:0% +fact think think about what's happened +just to computers I mean some of you + + align:start position:0% +just to computers I mean some of you + + + align:start position:0% +just to computers I mean some of you +must have old floppies that you can't + + align:start position:0% +must have old floppies that you can't + + + align:start position:0% +must have old floppies that you can't +use in your computers anymore I still I + + align:start position:0% +use in your computers anymore I still I + + + align:start position:0% +use in your computers anymore I still I +I still have an old computer that didn't + + align:start position:0% +I still have an old computer that didn't + + + align:start position:0% +I still have an old computer that didn't +have floppies that had a 256 uh uh uh uh + + align:start position:0% +have floppies that had a 256 uh uh uh uh + + + align:start position:0% +have floppies that had a 256 uh uh uh uh +kilobyte hard drive and that was the + + align:start position:0% +kilobyte hard drive and that was the + + + align:start position:0% +kilobyte hard drive and that was the +machine it was the first IBM machine uh + + align:start position:0% +machine it was the first IBM machine uh + + + align:start position:0% +machine it was the first IBM machine uh +so everything and you and then and what + + align:start position:0% +so everything and you and then and what + + + align:start position:0% +so everything and you and then and what +they they gave it to you with these + + align:start position:0% +they they gave it to you with these + + + align:start position:0% +they they gave it to you with these +giant big real floppies that's why they + + align:start position:0% +giant big real floppies that's why they + + + align:start position:0% +giant big real floppies that's why they +were called floppies they were very you + + align:start position:0% +were called floppies they were very you + + + align:start position:0% +were called floppies they were very you +could bend them you could and and that's + + align:start position:0% +could bend them you could and and that's + + + align:start position:0% +could bend them you could and and that's +become obsolete very quickly as well so + + align:start position:0% +become obsolete very quickly as well so + + + align:start position:0% +become obsolete very quickly as well so +so there's there's there's there's a + + align:start position:0% +so there's there's there's there's a + + + align:start position:0% +so there's there's there's there's a +principle of obsolescence that's built + + align:start position:0% +principle of obsolescence that's built + + + align:start position:0% +principle of obsolescence that's built +that's that that's built into the + + align:start position:0% +that's that that's built into the + + + align:start position:0% +that's that that's built into the +process uh as well but the primary point + + align:start position:0% +process uh as well but the primary point + + + align:start position:0% +process uh as well but the primary point +is the myth of technological determinism + + align:start position:0% +is the myth of technological determinism + + + align:start position:0% +is the myth of technological determinism +reminds us that it is not technological + + align:start position:0% +reminds us that it is not technological + + + align:start position:0% +reminds us that it is not technological +uh uh discoveries themselves that that + + align:start position:0% +uh uh discoveries themselves that that + + + align:start position:0% +uh uh discoveries themselves that that +explain uh why a particular technology + + align:start position:0% +explain uh why a particular technology + + + align:start position:0% +explain uh why a particular technology +becomes an embedded social form that has + + align:start position:0% +becomes an embedded social form that has + + + align:start position:0% +becomes an embedded social form that has +to do with the with the culture and the + + align:start position:0% +to do with the with the culture and the + + + align:start position:0% +to do with the with the culture and the +historical circumstances of the society + + align:start position:0% +historical circumstances of the society + + + align:start position:0% +historical circumstances of the society +in which the technology is + + align:start position:0% +in which the technology is + + + align:start position:0% +in which the technology is +embedded one of the most remarkable + + align:start position:0% +embedded one of the most remarkable + + + align:start position:0% +embedded one of the most remarkable +things about this evolutionary process + + align:start position:0% +things about this evolutionary process + + + align:start position:0% +things about this evolutionary process +I've been describing as I said earlier + + align:start position:0% +I've been describing as I said earlier + + + align:start position:0% +I've been describing as I said earlier +is how swift it is how fast it is how we + + align:start position:0% +is how swift it is how fast it is how we + + + align:start position:0% +is how swift it is how fast it is how we +go from being a mere novelty to becoming + + align:start position:0% +go from being a mere novelty to becoming + + + align:start position:0% +go from being a mere novelty to becoming +a a significant social form by 1910 or + + align:start position:0% +a a significant social form by 1910 or + + + align:start position:0% +a a significant social form by 1910 or +so and to becoming a a virtually + + align:start position:0% +so and to becoming a a virtually + + + align:start position:0% +so and to becoming a a virtually +Universal aesthetic and entertainment + + align:start position:0% +Universal aesthetic and entertainment + + + align:start position:0% +Universal aesthetic and entertainment +experience for the majority of the + + align:start position:0% +experience for the majority of the + + + align:start position:0% +experience for the majority of the +population in the country by 1920 so in + + align:start position:0% +population in the country by 1920 so in + + + align:start position:0% +population in the country by 1920 so in +something like 20 or 25 years the movies + + align:start position:0% +something like 20 or 25 years the movies + + + align:start position:0% +something like 20 or 25 years the movies +go from being an absolutely unknown or + + align:start position:0% +go from being an absolutely unknown or + + + align:start position:0% +go from being an absolutely unknown or +trivial novelty sharing space with + + align:start position:0% +trivial novelty sharing space with + + + align:start position:0% +trivial novelty sharing space with +fortune tellers and strip and and strip + + align:start position:0% +fortune tellers and strip and and strip + + + align:start position:0% +fortune tellers and strip and and strip +shows in the penny arcades to becoming + + align:start position:0% +shows in the penny arcades to becoming + + + align:start position:0% +shows in the penny arcades to becoming +not just an embedded social form but one + + align:start position:0% +not just an embedded social form but one + + + align:start position:0% +not just an embedded social form but one +of the dominant economic engines of the + + align:start position:0% +of the dominant economic engines of the + + + align:start position:0% +of the dominant economic engines of the +society employing tens of thousands of + + align:start position:0% +society employing tens of thousands of + + + align:start position:0% +society employing tens of thousands of +people in various uh direct and + + align:start position:0% +people in various uh direct and + + + align:start position:0% +people in various uh direct and +ancillary positions and mobilizing + + align:start position:0% +ancillary positions and mobilizing + + + align:start position:0% +ancillary positions and mobilizing +virtually the entire population of the + + align:start position:0% +virtually the entire population of the + + + align:start position:0% +virtually the entire population of the +country in an an in a regular routine + + align:start position:0% +country in an an in a regular routine + + + align:start position:0% +country in an an in a regular routine +and habitual experience uh um uh to + + align:start position:0% +and habitual experience uh um uh to + + + align:start position:0% +and habitual experience uh um uh to +which they return again and again and + + align:start position:0% +which they return again and again and + + + align:start position:0% +which they return again and again and +because the audience is returning again + + align:start position:0% +because the audience is returning again + + + align:start position:0% +because the audience is returning again +and again I remember I said there's a + + align:start position:0% +and again I remember I said there's a + + + align:start position:0% +and again I remember I said there's a +kind of symbiotic relation between the + + align:start position:0% +kind of symbiotic relation between the + + + align:start position:0% +kind of symbiotic relation between the +audience and the because the audience is + + align:start position:0% +audience and the because the audience is + + + align:start position:0% +audience and the because the audience is +returning again and again what happens + + align:start position:0% +returning again and again what happens + + + align:start position:0% +returning again and again what happens +that's also an aspect of the resources + + align:start position:0% +that's also an aspect of the resources + + + align:start position:0% +that's also an aspect of the resources +that are available to the medium what + + align:start position:0% +that are available to the medium what + + + align:start position:0% +that are available to the medium what +begins then to develop our form our are + + align:start position:0% +begins then to develop our form our are + + + align:start position:0% +begins then to develop our form our are +forms of Storytelling that rely on the + + align:start position:0% +forms of Storytelling that rely on the + + + align:start position:0% +forms of Storytelling that rely on the +audiences prior memory of other shows + + align:start position:0% +audiences prior memory of other shows + + + align:start position:0% +audiences prior memory of other shows +right so that one thing that emerges + + align:start position:0% +right so that one thing that emerges + + + align:start position:0% +right so that one thing that emerges +very quickly is what we might call a + + align:start position:0% +very quickly is what we might call a + + + align:start position:0% +very quickly is what we might call a +star system in which particular actors + + align:start position:0% +star system in which particular actors + + + align:start position:0% +star system in which particular actors +are become identified with particular + + align:start position:0% +are become identified with particular + + + align:start position:0% +are become identified with particular +kinds of roles and audiences want to I + + align:start position:0% +kinds of roles and audiences want to I + + + align:start position:0% +kinds of roles and audiences want to I +come back to see those Stars again and + + align:start position:0% +come back to see those Stars again and + + + align:start position:0% +come back to see those Stars again and +again what also begins to happen is the + + align:start position:0% +again what also begins to happen is the + + + align:start position:0% +again what also begins to happen is the +establishment of a very rigorous kind of + + align:start position:0% +establishment of a very rigorous kind of + + + align:start position:0% +establishment of a very rigorous kind of +genre system what's a + + align:start position:0% +genre system what's a + + + align:start position:0% +genre system what's a +genre a category of story The Western is + + align:start position:0% +genre a category of story The Western is + + + align:start position:0% +genre a category of story The Western is +a genre the detective story is a genre + + align:start position:0% +a genre the detective story is a genre + + + align:start position:0% +a genre the detective story is a genre +the elegy is a poetic genre right that + + align:start position:0% +the elegy is a poetic genre right that + + + align:start position:0% +the elegy is a poetic genre right that +so so genres so and and the movies the + + align:start position:0% +so so genres so and and the movies the + + + align:start position:0% +so so genres so and and the movies the +typical the fundamental movie genres + + align:start position:0% +typical the fundamental movie genres + + + align:start position:0% +typical the fundamental movie genres +begin to emerge relatively early There's + + align:start position:0% +begin to emerge relatively early There's + + + align:start position:0% +begin to emerge relatively early There's +a western adventure story there's a + + align:start position:0% +a western adventure story there's a + + + align:start position:0% +a western adventure story there's a +historical spectacle uh there are + + align:start position:0% +historical spectacle uh there are + + + align:start position:0% +historical spectacle uh there are +certain for of urban crime narrative + + align:start position:0% +certain for of urban crime narrative + + + align:start position:0% +certain for of urban crime narrative +that that became our detective and crime + + align:start position:0% +that that became our detective and crime + + + align:start position:0% +that that became our detective and crime +films at a later at a later stage and + + align:start position:0% +films at a later at a later stage and + + + align:start position:0% +films at a later at a later stage and +there are certain and there emerge + + align:start position:0% +there are certain and there emerge + + + align:start position:0% +there are certain and there emerge +especially certain forms of satire and + + align:start position:0% +especially certain forms of satire and + + + align:start position:0% +especially certain forms of satire and +comedy so so a genre system begins to + + align:start position:0% +comedy so so a genre system begins to + + + align:start position:0% +comedy so so a genre system begins to +emerge as well and there there are + + align:start position:0% +emerge as well and there there are + + + align:start position:0% +emerge as well and there there are +reasons of course why this kind of thing + + align:start position:0% +reasons of course why this kind of thing + + + align:start position:0% +reasons of course why this kind of thing +is useful to a mass production system to + + align:start position:0% +is useful to a mass production system to + + + align:start position:0% +is useful to a mass production system to +a system an assembly line system because + + align:start position:0% +a system an assembly line system because + + + align:start position:0% +a system an assembly line system because +look if you make seven westerns uh if + + align:start position:0% +look if you make seven westerns uh if + + + align:start position:0% +look if you make seven westerns uh if +the same uh movie studio makes seven + + align:start position:0% +the same uh movie studio makes seven + + + align:start position:0% +the same uh movie studio makes seven +westerns they can use the same horses + + align:start position:0% +westerns they can use the same horses + + + align:start position:0% +westerns they can use the same horses +again and again they can use the same + + align:start position:0% +again and again they can use the same + + + align:start position:0% +again and again they can use the same +set they can use the same hats they + + align:start position:0% +set they can use the same hats they + + + align:start position:0% +set they can use the same hats they +might even be and this in fact happened + + align:start position:0% +might even be and this in fact happened + + + align:start position:0% +might even be and this in fact happened +they might even be be able to use the + + align:start position:0% +they might even be be able to use the + + + align:start position:0% +they might even be be able to use the +same clip of film that shows a cattle + + align:start position:0% +same clip of film that shows a cattle + + + align:start position:0% +same clip of film that shows a cattle +Stampede in seven different movies + + align:start position:0% +Stampede in seven different movies + + + align:start position:0% +Stampede in seven different movies +because nobody would actually see it so + + align:start position:0% +because nobody would actually see it so + + + align:start position:0% +because nobody would actually see it so +economies of scale become possible uh as + + align:start position:0% +economies of scale become possible uh as + + + align:start position:0% +economies of scale become possible uh as +the system begins to regularize itself + + align:start position:0% +the system begins to regularize itself + + + align:start position:0% +the system begins to regularize itself +once it stabilizes after that period of + + align:start position:0% +once it stabilizes after that period of + + + align:start position:0% +once it stabilizes after that period of +imitation and patent Warfare right so + + align:start position:0% +imitation and patent Warfare right so + + + align:start position:0% +imitation and patent Warfare right so +one of the things and there's and + + align:start position:0% +one of the things and there's and + + + align:start position:0% +one of the things and there's and +there's nothing Noble or artistic or or + + align:start position:0% +there's nothing Noble or artistic or or + + + align:start position:0% +there's nothing Noble or artistic or or +or conscious + + align:start position:0% +or conscious + + + align:start position:0% +or conscious +uh about this development that's part of + + align:start position:0% +uh about this development that's part of + + + align:start position:0% +uh about this development that's part of +what makes it so remarkable and it puts + + align:start position:0% +what makes it so remarkable and it puts + + + align:start position:0% +what makes it so remarkable and it puts +us in touch with a paradox that's at the + + align:start position:0% +us in touch with a paradox that's at the + + + align:start position:0% +us in touch with a paradox that's at the +very heart of what I hope to make you + + align:start position:0% +very heart of what I hope to make you + + + align:start position:0% +very heart of what I hope to make you +aware of in this course it's a paradox + + align:start position:0% +aware of in this course it's a paradox + + + align:start position:0% +aware of in this course it's a paradox +that I guess it animates my transition + + align:start position:0% +that I guess it animates my transition + + + align:start position:0% +that I guess it animates my transition +many years ago now from a traditional + + align:start position:0% +many years ago now from a traditional + + + align:start position:0% +many years ago now from a traditional +literary scholar into someone interested + + align:start position:0% +literary scholar into someone interested + + + align:start position:0% +literary scholar into someone interested +in film and media and it's this Paradox + + align:start position:0% +in film and media and it's this Paradox + + + align:start position:0% +in film and media and it's this Paradox +that based on what I've been telling you + + align:start position:0% +that based on what I've been telling you + + + align:start position:0% +that based on what I've been telling you +about this Evolution this evolution of + + align:start position:0% +about this Evolution this evolution of + + + align:start position:0% +about this Evolution this evolution of +the medium of of the film medium it's + + align:start position:0% +the medium of of the film medium it's + + + align:start position:0% +the medium of of the film medium it's +the Paradox that capitalist + + align:start position:0% +the Paradox that capitalist + + + align:start position:0% +the Paradox that capitalist +greed the crassest of alliances between + + align:start position:0% +greed the crassest of alliances between + + + align:start position:0% +greed the crassest of alliances between +Commerce and modern + + align:start position:0% +Commerce and modern + + + align:start position:0% +Commerce and modern +technology might be the enabling + + align:start position:0% +technology might be the enabling + + + align:start position:0% +technology might be the enabling +conditions of a complex narrative art + + align:start position:0% +conditions of a complex narrative art + + + align:start position:0% +conditions of a complex narrative art +right where does art come from it's + + align:start position:0% +right where does art come from it's + + + align:start position:0% +right where does art come from it's +about the it's not just about art though + + align:start position:0% +about the it's not just about art though + + + align:start position:0% +about the it's not just about art though +even about sort of social even if even + + align:start position:0% +even about sort of social even if even + + + align:start position:0% +even about sort of social even if even +if we forget the question of Art and + + align:start position:0% +if we forget the question of Art and + + + align:start position:0% +if we forget the question of Art and +just talk about sort of the the social + + align:start position:0% +just talk about sort of the the social + + + align:start position:0% +just talk about sort of the the social +and cultural importance of movieo in + + align:start position:0% +and cultural importance of movieo in + + + align:start position:0% +and cultural importance of movieo in +modern societies leave out the question + + align:start position:0% +modern societies leave out the question + + + align:start position:0% +modern societies leave out the question +of whether it's an aesthetically + + align:start position:0% +of whether it's an aesthetically + + + align:start position:0% +of whether it's an aesthetically +valuable experience it's so Central to + + align:start position:0% +valuable experience it's so Central to + + + align:start position:0% +valuable experience it's so Central to +Human Experience remain so Central to + + align:start position:0% +Human Experience remain so Central to + + + align:start position:0% +Human Experience remain so Central to +Human Experience that there's a + + align:start position:0% +Human Experience that there's a + + + align:start position:0% +Human Experience that there's a +tremendous par that there's a tremendous + + align:start position:0% +tremendous par that there's a tremendous + + + align:start position:0% +tremendous par that there's a tremendous +Paradox in this that the that the crest + + align:start position:0% +Paradox in this that the that the crest + + + align:start position:0% +Paradox in this that the that the crest +of alliances between Commerce and + + align:start position:0% +of alliances between Commerce and + + + align:start position:0% +of alliances between Commerce and +Technology right nothing Noble or + + align:start position:0% +Technology right nothing Noble or + + + align:start position:0% +Technology right nothing Noble or +admirable about it nobody's sitting down + + align:start position:0% +admirable about it nobody's sitting down + + + align:start position:0% +admirable about it nobody's sitting down +thinking I want to make a new great + + align:start position:0% +thinking I want to make a new great + + + align:start position:0% +thinking I want to make a new great +medium for art nonetheless become these + + align:start position:0% +medium for art nonetheless become these + + + align:start position:0% +medium for art nonetheless become these +this Alliance becomes the enabling + + align:start position:0% +this Alliance becomes the enabling + + + align:start position:0% +this Alliance becomes the enabling +conditions for a complex form of social + + align:start position:0% +conditions for a complex form of social + + + align:start position:0% +conditions for a complex form of social +experience and of narrative art well + + align:start position:0% +experience and of narrative art well + + + align:start position:0% +experience and of narrative art well +that Paradox is at the heart of a lot of + + align:start position:0% +that Paradox is at the heart of a lot of + + + align:start position:0% +that Paradox is at the heart of a lot of +what we will be looking at in this + + align:start position:0% +what we will be looking at in this + + + align:start position:0% +what we will be looking at in this +course so I hope you'll keep it in mind + + align:start position:0% +course so I hope you'll keep it in mind + + + align:start position:0% +course so I hope you'll keep it in mind +as we go on I'd like to say a couple of + + align:start position:0% +as we go on I'd like to say a couple of + + + align:start position:0% +as we go on I'd like to say a couple of +words not too many a couple of words + + align:start position:0% +words not too many a couple of words + + + align:start position:0% +words not too many a couple of words +about the um The Great Train Robbery the + + align:start position:0% +about the um The Great Train Robbery the + + + align:start position:0% +about the um The Great Train Robbery the +very first uh film that you've seen uh + + align:start position:0% +very first uh film that you've seen uh + + + align:start position:0% +very first uh film that you've seen uh +this The Great Train Robbery is + + align:start position:0% +this The Great Train Robbery is + + + align:start position:0% +this The Great Train Robbery is +discussed in some helpful detail in + + align:start position:0% +discussed in some helpful detail in + + + align:start position:0% +discussed in some helpful detail in +David Cook's history of narrative film + + align:start position:0% +David Cook's history of narrative film + + + align:start position:0% +David Cook's history of narrative film +and I urge you to look closely at his + + align:start position:0% +and I urge you to look closely at his + + + align:start position:0% +and I urge you to look closely at his +account of it but I want to remind you + + align:start position:0% +account of it but I want to remind you + + + align:start position:0% +account of it but I want to remind you +of about a couple of highlights one is + + align:start position:0% +of about a couple of highlights one is + + + align:start position:0% +of about a couple of highlights one is +that that although The Great Train + + align:start position:0% +that that although The Great Train + + + align:start position:0% +that that although The Great Train +Robbery seems very primitive to us it's + + align:start position:0% +Robbery seems very primitive to us it's + + + align:start position:0% +Robbery seems very primitive to us it's +important to realize that even The Great + + align:start position:0% +important to realize that even The Great + + + align:start position:0% +important to realize that even The Great +Train Robbery is already a refined text + + align:start position:0% +Train Robbery is already a refined text + + + align:start position:0% +Train Robbery is already a refined text +a almost most most of the most + + align:start position:0% +a almost most most of the most + + + align:start position:0% +a almost most most of the most +fundamental principles of what we might + + align:start position:0% +fundamental principles of what we might + + + align:start position:0% +fundamental principles of what we might +call the syntax or grammar of the movies + + align:start position:0% +call the syntax or grammar of the movies + + + align:start position:0% +call the syntax or grammar of the movies +is already embedded in The Great Train + + align:start position:0% +is already embedded in The Great Train + + + align:start position:0% +is already embedded in The Great Train +Robbery and what that means is that the + + align:start position:0% +Robbery and what that means is that the + + + align:start position:0% +Robbery and what that means is that the +period the five or six year period + + align:start position:0% +period the five or six year period + + + align:start position:0% +period the five or six year period +before that when there is all this + + align:start position:0% +before that when there is all this + + + align:start position:0% +before that when there is all this +practice in with non-narrative forms uh + + align:start position:0% +practice in with non-narrative forms uh + + + align:start position:0% +practice in with non-narrative forms uh +lies behind The Great Train Robbery and + + align:start position:0% +lies behind The Great Train Robbery and + + + align:start position:0% +lies behind The Great Train Robbery and +some and what also lies behind The Great + + align:start position:0% +some and what also lies behind The Great + + + align:start position:0% +some and what also lies behind The Great +Train Robbery is this experience of + + align:start position:0% +Train Robbery is this experience of + + + align:start position:0% +Train Robbery is this experience of +audiences going in to the to first to + + align:start position:0% +audiences going in to the to first to + + + align:start position:0% +audiences going in to the to first to +the penny arcades then to the + + align:start position:0% +the penny arcades then to the + + + align:start position:0% +the penny arcades then to the +Nickelodeons begin to open up in the in + + align:start position:0% +Nickelodeons begin to open up in the in + + + align:start position:0% +Nickelodeons begin to open up in the in +in the by the turn of the 20th century + + align:start position:0% +in the by the turn of the 20th century + + + align:start position:0% +in the by the turn of the 20th century +uh and becoming impatient with repeated + + align:start position:0% +uh and becoming impatient with repeated + + + align:start position:0% +uh and becoming impatient with repeated +scenes that simply show uh jokes uh + + align:start position:0% +scenes that simply show uh jokes uh + + + align:start position:0% +scenes that simply show uh jokes uh +hoses going off in people's faces or + + align:start position:0% +hoses going off in people's faces or + + + align:start position:0% +hoses going off in people's faces or +trains coming into a state after a while + + align:start position:0% +trains coming into a state after a while + + + align:start position:0% +trains coming into a state after a while +the novelty wears off the audience wants + + align:start position:0% +the novelty wears off the audience wants + + + align:start position:0% +the novelty wears off the audience wants +but of course the people who are making + + align:start position:0% +but of course the people who are making + + + align:start position:0% +but of course the people who are making +films are also interested in what + + align:start position:0% +films are also interested in what + + + align:start position:0% +films are also interested in what +they're doing you can feel especially if + + align:start position:0% +they're doing you can feel especially if + + + align:start position:0% +they're doing you can feel especially if +you look at DW Griffith's shorts and + + align:start position:0% +you look at DW Griffith's shorts and + + + align:start position:0% +you look at DW Griffith's shorts and +you've looked at two you will have + + align:start position:0% +you've looked at two you will have + + + align:start position:0% +you've looked at two you will have +looked at two of them in this course uh + + align:start position:0% +looked at two of them in this course uh + + + align:start position:0% +looked at two of them in this course uh +the uh a beast at Bay from last time and + + align:start position:0% +the uh a beast at Bay from last time and + + + align:start position:0% +the uh a beast at Bay from last time and +the Londale operator which you'll see + + align:start position:0% +the Londale operator which you'll see + + + align:start position:0% +the Londale operator which you'll see +tonight before we turn to the Kon films + + align:start position:0% +tonight before we turn to the Kon films + + + align:start position:0% +tonight before we turn to the Kon films +uh and you'll see in these are just a + + align:start position:0% +uh and you'll see in these are just a + + + align:start position:0% +uh and you'll see in these are just a +sampling of his of his early work but if + + align:start position:0% +sampling of his of his early work but if + + + align:start position:0% +sampling of his of his early work but if +you look closely at those where you can + + align:start position:0% +you look closely at those where you can + + + align:start position:0% +you look closely at those where you can +feel Griffith's own excitement at + + align:start position:0% +feel Griffith's own excitement at + + + align:start position:0% +feel Griffith's own excitement at +discovering the possibilities of the + + align:start position:0% +discovering the possibilities of the + + + align:start position:0% +discovering the possibilities of the +cinema learn in many cases these F you + + align:start position:0% +cinema learn in many cases these F you + + + align:start position:0% +cinema learn in many cases these F you +Griffith is doing what doing some things + + align:start position:0% +Griffith is doing what doing some things + + + align:start position:0% +Griffith is doing what doing some things +with the camera doing some things with + + align:start position:0% +with the camera doing some things with + + + align:start position:0% +with the camera doing some things with +narrative shape with the shaping of + + align:start position:0% +narrative shape with the shaping of + + + align:start position:0% +narrative shape with the shaping of +narrative in in cinema that had never + + align:start position:0% +narrative in in cinema that had never + + + align:start position:0% +narrative in in cinema that had never +been done before and you can feel his + + align:start position:0% +been done before and you can feel his + + + align:start position:0% +been done before and you can feel his +own excitement at the possibility of + + align:start position:0% +own excitement at the possibility of + + + align:start position:0% +own excitement at the possibility of +this of this astonishing of this + + align:start position:0% +this of this astonishing of this + + + align:start position:0% +this of this astonishing of this +astonishing technology well The Great + + align:start position:0% +astonishing technology well The Great + + + align:start position:0% +astonishing technology well The Great +Train Robbery the most important + + align:start position:0% +Train Robbery the most important + + + align:start position:0% +Train Robbery the most important +discovery that The Great Train Robbery + + align:start position:0% +discovery that The Great Train Robbery + + + align:start position:0% +discovery that The Great Train Robbery +shows us and again it seems so obvious + + align:start position:0% +shows us and again it seems so obvious + + + align:start position:0% +shows us and again it seems so obvious +and so embedded that we wouldn't even + + align:start position:0% +and so embedded that we wouldn't even + + + align:start position:0% +and so embedded that we wouldn't even +think about it today we've absorbed + + align:start position:0% +think about it today we've absorbed + + + align:start position:0% +think about it today we've absorbed +these principles so deeply into our DNA + + align:start position:0% +these principles so deeply into our DNA + + + align:start position:0% +these principles so deeply into our DNA +that we don't even think of we're we're + + align:start position:0% +that we don't even think of we're we're + + + align:start position:0% +that we don't even think of we're we're +we learn how to watch movies in this way + + align:start position:0% +we learn how to watch movies in this way + + + align:start position:0% +we learn how to watch movies in this way +from the gra from the cradle in some + + align:start position:0% +from the gra from the cradle in some + + + align:start position:0% +from the gra from the cradle in some +ways be because we we're but by the time + + align:start position:0% +ways be because we we're but by the time + + + align:start position:0% +ways be because we we're but by the time +most most people today are five or six + + align:start position:0% +most most people today are five or six + + + align:start position:0% +most most people today are five or six +years old they've been subjected + + align:start position:0% +years old they've been subjected + + + align:start position:0% +years old they've been subjected +probably to more audiovisual images than + + align:start position:0% +probably to more audiovisual images than + + + align:start position:0% +probably to more audiovisual images than +anyone alive in 1900 and that's you know + + align:start position:0% +anyone alive in 1900 and that's you know + + + align:start position:0% +anyone alive in 1900 and that's you know +we're we're just cognitively different + + align:start position:0% +we're we're just cognitively different + + + align:start position:0% +we're we're just cognitively different +from from the in terms of our capacity + + align:start position:0% +from from the in terms of our capacity + + + align:start position:0% +from from the in terms of our capacity +to process audiovisual information uh we + + align:start position:0% +to process audiovisual information uh we + + + align:start position:0% +to process audiovisual information uh we +and but imagine an audience that's + + align:start position:0% +and but imagine an audience that's + + + align:start position:0% +and but imagine an audience that's +completely illiterate in these things + + align:start position:0% +completely illiterate in these things + + + align:start position:0% +completely illiterate in these things +that has to learn this system as the + + align:start position:0% +that has to learn this system as the + + + align:start position:0% +that has to learn this system as the +system itself is evolving that's part of + + align:start position:0% +system itself is evolving that's part of + + + align:start position:0% +system itself is evolving that's part of +the excitement of looking at these at at + + align:start position:0% +the excitement of looking at these at at + + + align:start position:0% +the excitement of looking at these at at +these early films and the most important + + align:start position:0% +these early films and the most important + + + align:start position:0% +these early films and the most important +Discovery in the in the Great Train + + align:start position:0% +Discovery in the in the Great Train + + + align:start position:0% +Discovery in the in the Great Train +Robbery is the discovery that the shot + + align:start position:0% +Robbery is the discovery that the shot + + + align:start position:0% +Robbery is the discovery that the shot +the single + + align:start position:0% +the single + + + align:start position:0% +the single +the + + align:start position:0% +the + + + align:start position:0% +the +single uncut shot of film however long + + align:start position:0% +single uncut shot of film however long + + + align:start position:0% +single uncut shot of film however long +it lasts and its length is dependent on + + align:start position:0% +it lasts and its length is dependent on + + + align:start position:0% +it lasts and its length is dependent on +on the decision you make about when to + + align:start position:0% +on the decision you make about when to + + + align:start position:0% +on the decision you make about when to +edit it right uh so it can it can go on + + align:start position:0% +edit it right uh so it can it can go on + + + align:start position:0% +edit it right uh so it can it can go on +for a long time or it can be very short + + align:start position:0% +for a long time or it can be very short + + + align:start position:0% +for a long time or it can be very short +and and the length or the shortness of a + + align:start position:0% +and and the length or the shortness of a + + + align:start position:0% +and and the length or the shortness of a +of of of cuts also affects sort of the + + align:start position:0% +of of of cuts also affects sort of the + + + align:start position:0% +of of of cuts also affects sort of the +rhythm of your experience in the film + + align:start position:0% +rhythm of your experience in the film + + + align:start position:0% +rhythm of your experience in the film +this is something that you can see + + align:start position:0% +this is something that you can see + + + align:start position:0% +this is something that you can see +Griffith practicing with even as as as + + align:start position:0% +Griffith practicing with even as as as + + + align:start position:0% +Griffith practicing with even as as as +early as a beast at Bay if you think + + align:start position:0% +early as a beast at Bay if you think + + + align:start position:0% +early as a beast at Bay if you think +about the great climax of the beast at + + align:start position:0% +about the great climax of the beast at + + + align:start position:0% +about the great climax of the beast at +bay where you have the where you have + + align:start position:0% +bay where you have the where you have + + + align:start position:0% +bay where you have the where you have +the uh uh + + align:start position:0% +the uh uh + + + align:start position:0% +the uh uh +um uh the the woman the woman being + + align:start position:0% +um uh the the woman the woman being + + + align:start position:0% +um uh the the woman the woman being +threatened but you also have this sort + + align:start position:0% +threatened but you also have this sort + + + align:start position:0% +threatened but you also have this sort +of this sort of race in the automobile + + align:start position:0% +of this sort of race in the automobile + + + align:start position:0% +of this sort of race in the automobile +to try to to try to get there on time + + align:start position:0% +to try to to try to get there on time + + + align:start position:0% +to try to to try to get there on time +and then and then the race to rescue her + + align:start position:0% +and then and then the race to rescue her + + + align:start position:0% +and then and then the race to rescue her +by a variety of people you could what + + align:start position:0% +by a variety of people you could what + + + align:start position:0% +by a variety of people you could what +what Griffith does is he cuts back and + + align:start position:0% +what Griffith does is he cuts back and + + + align:start position:0% +what Griffith does is he cuts back and +forth he creates the principle of + + align:start position:0% +forth he creates the principle of + + + align:start position:0% +forth he creates the principle of +parallel action what he realized what he + + align:start position:0% +parallel action what he realized what he + + + align:start position:0% +parallel action what he realized what he +discovered was that the audience will + + align:start position:0% +discovered was that the audience will + + + align:start position:0% +discovered was that the audience will +recognize this kind of cutting as + + align:start position:0% +recognize this kind of cutting as + + + align:start position:0% +recognize this kind of cutting as +showing you simultaneity showing you + + align:start position:0% +showing you simultaneity showing you + + + align:start position:0% +showing you simultaneity showing you +things that are going on at the same + + align:start position:0% +things that are going on at the same + + + align:start position:0% +things that are going on at the same +time and was what he what he discovered + + align:start position:0% +time and was what he what he discovered + + + align:start position:0% +time and was what he what he discovered +were in a certain sense how the mind how + + align:start position:0% +were in a certain sense how the mind how + + + align:start position:0% +were in a certain sense how the mind how +how we would cognitively process certain + + align:start position:0% +how we would cognitively process certain + + + align:start position:0% +how we would cognitively process certain +kinds of gestures on film and what he + + align:start position:0% +kinds of gestures on film and what he + + + align:start position:0% +kinds of gestures on film and what he +discovered of course is that if he cuts + + align:start position:0% +discovered of course is that if he cuts + + + align:start position:0% +discovered of course is that if he cuts +if he edits more quickly if he creates a + + align:start position:0% +if he edits more quickly if he creates a + + + align:start position:0% +if he edits more quickly if he creates a +fast Rhythm he creates excitement and if + + align:start position:0% +fast Rhythm he creates excitement and if + + + align:start position:0% +fast Rhythm he creates excitement and if +he create and what he began to discover + + align:start position:0% +he create and what he began to discover + + + align:start position:0% +he create and what he began to discover +was something that in later directors + + align:start position:0% +was something that in later directors + + + align:start position:0% +was something that in later directors +like Hitchcock would carry to an to an + + align:start position:0% +like Hitchcock would carry to an to an + + + align:start position:0% +like Hitchcock would carry to an to an +almost evil pitch a capacity to + + align:start position:0% +almost evil pitch a capacity to + + + align:start position:0% +almost evil pitch a capacity to +manipulate and control the audience's + + align:start position:0% +manipulate and control the audience's + + + align:start position:0% +manipulate and control the audience's +reaction by the speed with which + + align:start position:0% +reaction by the speed with which + + + align:start position:0% +reaction by the speed with which +particular images appear or disappear so + + align:start position:0% +particular images appear or disappear so + + + align:start position:0% +particular images appear or disappear so +so Griffith even if this early stage you + + align:start position:0% +so Griffith even if this early stage you + + + align:start position:0% +so Griffith even if this early stage you +can see Griffith discovering important + + align:start position:0% +can see Griffith discovering important + + + align:start position:0% +can see Griffith discovering important +principles the most fundamental + + align:start position:0% +principles the most fundamental + + + align:start position:0% +principles the most fundamental +principle in a Great Train Robbery which + + align:start position:0% +principle in a Great Train Robbery which + + + align:start position:0% +principle in a Great Train Robbery which +is not a Griffith film precedes Griffith + + align:start position:0% +is not a Griffith film precedes Griffith + + + align:start position:0% +is not a Griffith film precedes Griffith +is the discovery that the shot is the + + align:start position:0% +is the discovery that the shot is the + + + align:start position:0% +is the discovery that the shot is the +basic unit of action why is that a great + + align:start position:0% +basic unit of action why is that a great + + + align:start position:0% +basic unit of action why is that a great +discovery well if you think of the if + + align:start position:0% +discovery well if you think of the if + + + align:start position:0% +discovery well if you think of the if +you think of the movies as as a as a + + align:start position:0% +you think of the movies as as a as a + + + align:start position:0% +you think of the movies as as a as a +device or as a as a as a medium that + + align:start position:0% +device or as a as a as a medium that + + + align:start position:0% +device or as a as a as a medium that +grows out of especially a theatrical + + align:start position:0% +grows out of especially a theatrical + + + align:start position:0% +grows out of especially a theatrical +dispensation grows out of other things + + align:start position:0% +dispensation grows out of other things + + + align:start position:0% +dispensation grows out of other things +as well novels feed into it visual art + + align:start position:0% +as well novels feed into it visual art + + + align:start position:0% +as well novels feed into it visual art +feeds into the movie + + align:start position:0% +feeds into the movie + + + align:start position:0% +feeds into the movie +but it's certainly true that most of the + + align:start position:0% +but it's certainly true that most of the + + + align:start position:0% +but it's certainly true that most of the +major sort of ways in which directors + + align:start position:0% +major sort of ways in which directors + + + align:start position:0% +major sort of ways in which directors +first conceived how to think about the + + align:start position:0% +first conceived how to think about the + + + align:start position:0% +first conceived how to think about the +experience of what's of what the camera + + align:start position:0% +experience of what's of what the camera + + + align:start position:0% +experience of what's of what the camera +is looking at they would they would have + + align:start position:0% +is looking at they would they would have + + + align:start position:0% +is looking at they would they would have +been influenced by their own experience + + align:start position:0% +been influenced by their own experience + + + align:start position:0% +been influenced by their own experience +of theater and if you think about it for + + align:start position:0% +of theater and if you think about it for + + + align:start position:0% +of theater and if you think about it for +a moment what you can see even in The + + align:start position:0% +a moment what you can see even in The + + + align:start position:0% +a moment what you can see even in The +Great Train Robbery and uh the an + + align:start position:0% +Great Train Robbery and uh the an + + + align:start position:0% +Great Train Robbery and uh the an +Impulse to treat the camera as a stable + + align:start position:0% +Impulse to treat the camera as a stable + + + align:start position:0% +Impulse to treat the camera as a stable +thing the camera doesn't move very the + + align:start position:0% +thing the camera doesn't move very the + + + align:start position:0% +thing the camera doesn't move very the +camera there are panning shots in which + + align:start position:0% +camera there are panning shots in which + + + align:start position:0% +camera there are panning shots in which +the camera will go like this right but + + align:start position:0% +the camera will go like this right but + + + align:start position:0% +the camera will go like this right but +the camera will not track it will not + + align:start position:0% +the camera will not track it will not + + + align:start position:0% +the camera will not track it will not +move back and forth or sideways off its + + align:start position:0% +move back and forth or sideways off its + + + align:start position:0% +move back and forth or sideways off its +off its in in The Great Train Robbery + + align:start position:0% +off its in in The Great Train Robbery + + + align:start position:0% +off its in in The Great Train Robbery +it's that's a discover that's a + + align:start position:0% +it's that's a discover that's a + + + align:start position:0% +it's that's a discover that's a +discovery that Griffith is going to make + + align:start position:0% +discovery that Griffith is going to make + + + align:start position:0% +discovery that Griffith is going to make +and will exploit uh and you can see it + + align:start position:0% +and will exploit uh and you can see it + + + align:start position:0% +and will exploit uh and you can see it +in in in a beast at Bay but in The Great + + align:start position:0% +in in in a beast at Bay but in The Great + + + align:start position:0% +in in in a beast at Bay but in The Great +Train Robbery we haven't got that far + + align:start position:0% +Train Robbery we haven't got that far + + + align:start position:0% +Train Robbery we haven't got that far +yet but what we have discovered what + + align:start position:0% +yet but what we have discovered what + + + align:start position:0% +yet but what we have discovered what +what Porter Edwin Porter did discover + + align:start position:0% +what Porter Edwin Porter did discover + + + align:start position:0% +what Porter Edwin Porter did discover +was that the shot is the basic unit of + + align:start position:0% +was that the shot is the basic unit of + + + align:start position:0% +was that the shot is the basic unit of +action and that and what this means is + + align:start position:0% +action and that and what this means is + + + align:start position:0% +action and that and what this means is +it's not simply what the camera sees but + + align:start position:0% +it's not simply what the camera sees but + + + align:start position:0% +it's not simply what the camera sees but +then how the shots are edited afterwards + + align:start position:0% +then how the shots are edited afterwards + + + align:start position:0% +then how the shots are edited afterwards +that is so crucial so what it what it + + align:start position:0% +that is so crucial so what it what it + + + align:start position:0% +that is so crucial so what it what it +came to understand was that the making + + align:start position:0% +came to understand was that the making + + + align:start position:0% +came to understand was that the making +of of any movie is always a two-stage + + align:start position:0% +of of any movie is always a two-stage + + + align:start position:0% +of of any movie is always a two-stage +process there's the shooting of the film + + align:start position:0% +process there's the shooting of the film + + + align:start position:0% +process there's the shooting of the film +and then there's the editing of the film + + align:start position:0% +and then there's the editing of the film + + + align:start position:0% +and then there's the editing of the film +right and that that itself is a + + align:start position:0% +right and that that itself is a + + + align:start position:0% +right and that that itself is a +fundamental disc but the idea that the + + align:start position:0% +fundamental disc but the idea that the + + + align:start position:0% +fundamental disc but the idea that the +shot is the unit of action instead of + + align:start position:0% +shot is the unit of action instead of + + + align:start position:0% +shot is the unit of action instead of +the scene was hard for Movie Makers to + + align:start position:0% +the scene was hard for Movie Makers to + + + align:start position:0% +the scene was hard for Movie Makers to +get because and what they would do they + + align:start position:0% +get because and what they would do they + + + align:start position:0% +get because and what they would do they +would set the camera up and then actors + + align:start position:0% +would set the camera up and then actors + + + align:start position:0% +would set the camera up and then actors +would walk in front of the camera they + + align:start position:0% +would walk in front of the camera they + + + align:start position:0% +would walk in front of the camera they +would do what they had to do and they + + align:start position:0% +would do what they had to do and they + + + align:start position:0% +would do what they had to do and they +would walk off what's going on there + + align:start position:0% +would walk off what's going on there + + + align:start position:0% +would walk off what's going on there +they're conceiving of cinematic space in + + align:start position:0% +they're conceiving of cinematic space in + + + align:start position:0% +they're conceiving of cinematic space in +Theatrical terms as soon as the camera + + align:start position:0% +Theatrical terms as soon as the camera + + + align:start position:0% +Theatrical terms as soon as the camera +is liberated taken off its Tri pod moved + + align:start position:0% +is liberated taken off its Tri pod moved + + + align:start position:0% +is liberated taken off its Tri pod moved +around in some way uh allowed to back up + + align:start position:0% +around in some way uh allowed to back up + + + align:start position:0% +around in some way uh allowed to back up +or or or or Come Close even allowed to + + align:start position:0% +or or or or Come Close even allowed to + + + align:start position:0% +or or or or Come Close even allowed to +move laterally or uh uh what we're + + align:start position:0% +move laterally or uh uh what we're + + + align:start position:0% +move laterally or uh uh what we're +beginning to do is to explore more + + align:start position:0% +beginning to do is to explore more + + + align:start position:0% +beginning to do is to explore more +systematically what the camera's unique + + align:start position:0% +systematically what the camera's unique + + + align:start position:0% +systematically what the camera's unique +features are how the theater is + + align:start position:0% +features are how the theater is + + + align:start position:0% +features are how the theater is +different from the movies how H how how + + align:start position:0% +different from the movies how H how how + + + align:start position:0% +different from the movies how H how how +certain effects are possible in the + + align:start position:0% +certain effects are possible in the + + + align:start position:0% +certain effects are possible in the +movies that would not be possible in the + + align:start position:0% +movies that would not be possible in the + + + align:start position:0% +movies that would not be possible in the +theater when you watch the Katon films + + align:start position:0% +theater when you watch the Katon films + + + align:start position:0% +theater when you watch the Katon films +that you're going to see tonight watch + + align:start position:0% +that you're going to see tonight watch + + + align:start position:0% +that you're going to see tonight watch +for the ways in which Katon repeatedly + + align:start position:0% +for the ways in which Katon repeatedly + + + align:start position:0% +for the ways in which Katon repeatedly +sets up situations so that such that + + align:start position:0% +sets up situations so that such that + + + align:start position:0% +sets up situations so that such that +when you see a particular gag of his a + + align:start position:0% +when you see a particular gag of his a + + + align:start position:0% +when you see a particular gag of his a +joke what you realize is that the joke + + align:start position:0% +joke what you realize is that the joke + + + align:start position:0% +joke what you realize is that the joke +could not have happened in the theater + + align:start position:0% +could not have happened in the theater + + + align:start position:0% +could not have happened in the theater +it could not have been told to you + + align:start position:0% +it could not have been told to you + + + align:start position:0% +it could not have been told to you +verbally the joke is visual the joke + + align:start position:0% +verbally the joke is visual the joke + + + align:start position:0% +verbally the joke is visual the joke +involves motion the the joke in the joke + + align:start position:0% +involves motion the the joke in the joke + + + align:start position:0% +involves motion the the joke in the joke +involves uh a recognition of the powers + + align:start position:0% +involves uh a recognition of the powers + + + align:start position:0% +involves uh a recognition of the powers +of the C of the powers of of of + + align:start position:0% +of the C of the powers of of of + + + align:start position:0% +of the C of the powers of of of +cinematic representation to tell stories + + align:start position:0% +cinematic representation to tell stories + + + align:start position:0% +cinematic representation to tell stories +uh and you'll see many examples of this + + align:start position:0% +uh and you'll see many examples of this + + + align:start position:0% +uh and you'll see many examples of this +in the in the in the uh Katon materials + + align:start position:0% +in the in the in the uh Katon materials + + + align:start position:0% +in the in the in the uh Katon materials +that you'll that you'll be looking at + + align:start position:0% +that you'll that you'll be looking at + + + align:start position:0% +that you'll that you'll be looking at +tonight so the so the one of the very + + align:start position:0% +tonight so the so the one of the very + + + align:start position:0% +tonight so the so the one of the very +first first discoveries that's made is + + align:start position:0% +first first discoveries that's made is + + + align:start position:0% +first first discoveries that's made is +the discovery that the shot is the basic + + align:start position:0% +the discovery that the shot is the basic + + + align:start position:0% +the discovery that the shot is the basic +unit of action uh a second Discovery is + + align:start position:0% +unit of action uh a second Discovery is + + + align:start position:0% +unit of action uh a second Discovery is +the recognition that you have to cut + + align:start position:0% +the recognition that you have to cut + + + align:start position:0% +the recognition that you have to cut +between scenes you do your editing + + align:start position:0% +between scenes you do your editing + + + align:start position:0% +between scenes you do your editing +between shots rather rather than and Mo + + align:start position:0% +between shots rather rather than and Mo + + + align:start position:0% +between shots rather rather than and Mo +and mostly what you do is you let scenes + + align:start position:0% +and mostly what you do is you let scenes + + + align:start position:0% +and mostly what you do is you let scenes +play out even though you might abruptly + + align:start position:0% +play out even though you might abruptly + + + align:start position:0% +play out even though you might abruptly +cut a scene before the action is + + align:start position:0% +cut a scene before the action is + + + align:start position:0% +cut a scene before the action is +completed one of that's another + + align:start position:0% +completed one of that's another + + + align:start position:0% +completed one of that's another +discovery that was made if you cut the + + align:start position:0% +discovery that was made if you cut the + + + align:start position:0% +discovery that was made if you cut the +scene if a person starts to walk toward + + align:start position:0% +scene if a person starts to walk toward + + + align:start position:0% +scene if a person starts to walk toward +the door the first earliest films they + + align:start position:0% +the door the first earliest films they + + + align:start position:0% +the door the first earliest films they +would show the person walking all the + + align:start position:0% +would show the person walking all the + + + align:start position:0% +would show the person walking all the +way to the end walking out of the door + + align:start position:0% +way to the end walking out of the door + + + align:start position:0% +way to the end walking out of the door +then filmmakers discovered way there's a + + align:start position:0% +then filmmakers discovered way there's a + + + align:start position:0% +then filmmakers discovered way there's a +way of creating a kind of quickness here + + align:start position:0% +way of creating a kind of quickness here + + + align:start position:0% +way of creating a kind of quickness here +because if I show thorburn walking + + align:start position:0% +because if I show thorburn walking + + + align:start position:0% +because if I show thorburn walking +toward the door starting and I cut and + + align:start position:0% +toward the door starting and I cut and + + + align:start position:0% +toward the door starting and I cut and +he knocks his glasses off uh and then I + + align:start position:0% +he knocks his glasses off uh and then I + + + align:start position:0% +he knocks his glasses off uh and then I +and then I cut and I wait till he gets + + align:start position:0% +and then I cut and I wait till he gets + + + align:start position:0% +and then I cut and I wait till he gets +to the door and we see him leaving the + + align:start position:0% +to the door and we see him leaving the + + + align:start position:0% +to the door and we see him leaving the +door I don't have to watch him take + + align:start position:0% +door I don't have to watch him take + + + align:start position:0% +door I don't have to watch him take +those 17 steps that right so what what + + align:start position:0% +those 17 steps that right so what what + + + align:start position:0% +those 17 steps that right so what what +what's been discovered is a basic + + align:start position:0% +what's been discovered is a basic + + + align:start position:0% +what's been discovered is a basic +principle of cinematic syntax right and + + align:start position:0% +principle of cinematic syntax right and + + + align:start position:0% +principle of cinematic syntax right and +but what but but it seems so obvious to + + align:start position:0% +but what but but it seems so obvious to + + + align:start position:0% +but what but but it seems so obvious to +us but of course it's really a great + + align:start position:0% +us but of course it's really a great + + + align:start position:0% +us but of course it's really a great +discovery it's a uh in words the the + + align:start position:0% +discovery it's a uh in words the the + + + align:start position:0% +discovery it's a uh in words the the +properties of the medium have to be + + align:start position:0% +properties of the medium have to be + + + align:start position:0% +properties of the medium have to be +understood before you can really begin + + align:start position:0% +understood before you can really begin + + + align:start position:0% +understood before you can really begin +to exploit it and that's why uh I've + + align:start position:0% +to exploit it and that's why uh I've + + + align:start position:0% +to exploit it and that's why uh I've +asked you to look at some of these short + + align:start position:0% +asked you to look at some of these short + + + align:start position:0% +asked you to look at some of these short +films none of the short films I've shown + + align:start position:0% +films none of the short films I've shown + + + align:start position:0% +films none of the short films I've shown +you are completely without uh some uh uh + + align:start position:0% +you are completely without uh some uh uh + + + align:start position:0% +you are completely without uh some uh uh +technical interest and uh even though of + + align:start position:0% +technical interest and uh even though of + + + align:start position:0% +technical interest and uh even though of +course they're the only films I'm + + align:start position:0% +course they're the only films I'm + + + align:start position:0% +course they're the only films I'm +showing you that I wouldn't sort of make + + align:start position:0% +showing you that I wouldn't sort of make + + + align:start position:0% +showing you that I wouldn't sort of make +arguments uh to defend them as works of + + align:start position:0% +arguments uh to defend them as works of + + + align:start position:0% +arguments uh to defend them as works of +art but I certainly would make Arguments + + align:start position:0% +art but I certainly would make Arguments + + + align:start position:0% +art but I certainly would make Arguments +for them as technically fascinating + + align:start position:0% +for them as technically fascinating + + + align:start position:0% +for them as technically fascinating +documents and I hope you'll I hope + + align:start position:0% +documents and I hope you'll I hope + + + align:start position:0% +documents and I hope you'll I hope +you'll look at them in in that light so + + align:start position:0% +you'll look at them in in that light so + + + align:start position:0% +you'll look at them in in that light so +the shot as a basic unit of Action + + align:start position:0% +the shot as a basic unit of Action + + + align:start position:0% +the shot as a basic unit of Action +cutting between scenes + + align:start position:0% +cutting between scenes + + + align:start position:0% +cutting between scenes +a couple of other things in the in the + + align:start position:0% +a couple of other things in the in the + + + align:start position:0% +a couple of other things in the in the +that I think are important in The Great + + align:start position:0% +that I think are important in The Great + + + align:start position:0% +that I think are important in The Great +Train Rob one is that you can see in The + + align:start position:0% +Train Rob one is that you can see in The + + + align:start position:0% +Train Rob one is that you can see in The +Great Train Robbery they're beginning to + + align:start position:0% +Great Train Robbery they're beginning to + + + align:start position:0% +Great Train Robbery they're beginning to +discover the value of camera placement + + align:start position:0% +discover the value of camera placement + + + align:start position:0% +discover the value of camera placement +what happens when you place the camera + + align:start position:0% +what happens when you place the camera + + + align:start position:0% +what happens when you place the camera +in a particular position that if the + + align:start position:0% +in a particular position that if the + + + align:start position:0% +in a particular position that if the +camera uh especially if action is coming + + align:start position:0% +camera uh especially if action is coming + + + align:start position:0% +camera uh especially if action is coming +toward the camera if you that you might + + align:start position:0% +toward the camera if you that you might + + + align:start position:0% +toward the camera if you that you might +not want to place the camera directly in + + align:start position:0% +not want to place the camera directly in + + + align:start position:0% +not want to place the camera directly in +front of the action that's coming toward + + align:start position:0% +front of the action that's coming toward + + + align:start position:0% +front of the action that's coming toward +you that something happens if you place + + align:start position:0% +you that something happens if you place + + + align:start position:0% +you that something happens if you place +it slightly awart it so it can see it at + + align:start position:0% +it slightly awart it so it can see it at + + + align:start position:0% +it slightly awart it so it can see it at +a slight angle it creates a greater + + align:start position:0% +a slight angle it creates a greater + + + align:start position:0% +a slight angle it creates a greater +illusion of depth in the image for + + align:start position:0% +illusion of depth in the image for + + + align:start position:0% +illusion of depth in the image for +example and it does other kinds of it + + align:start position:0% +example and it does other kinds of it + + + align:start position:0% +example and it does other kinds of it +lets the action get closer to you before + + align:start position:0% +lets the action get closer to you before + + + align:start position:0% +lets the action get closer to you before +before the uh scene has to be cut uh so + + align:start position:0% +before the uh scene has to be cut uh so + + + align:start position:0% +before the uh scene has to be cut uh so +camera placement is something that you + + align:start position:0% +camera placement is something that you + + + align:start position:0% +camera placement is something that you +can see is is beginning to be learned + + align:start position:0% +can see is is beginning to be learned + + + align:start position:0% +can see is is beginning to be learned +beginning to be mastered in the great in + + align:start position:0% +beginning to be mastered in the great in + + + align:start position:0% +beginning to be mastered in the great in +The Great Train Robbery and F camera or + + align:start position:0% +The Great Train Robbery and F camera or + + + align:start position:0% +The Great Train Robbery and F camera or +or camera position so there are other + + align:start position:0% +or camera position so there are other + + + align:start position:0% +or camera position so there are other +thing and finally one might mention one + + align:start position:0% +thing and finally one might mention one + + + align:start position:0% +thing and finally one might mention one +other thing that again establishes a + + align:start position:0% +other thing that again establishes a + + + align:start position:0% +other thing that again establishes a +principle that begins that that that + + align:start position:0% +principle that begins that that that + + + align:start position:0% +principle that begins that that that +then is continued continues in use for + + align:start position:0% +then is continued continues in use for + + + align:start position:0% +then is continued continues in use for +50 or 75 years and that's the principle + + align:start position:0% +50 or 75 years and that's the principle + + + align:start position:0% +50 or 75 years and that's the principle +of the process shot you can see in the + + align:start position:0% +of the process shot you can see in the + + + align:start position:0% +of the process shot you can see in the +Great Train Robbery that he that some + + align:start position:0% +Great Train Robbery that he that some + + + align:start position:0% +Great Train Robbery that he that some +effects have been created by tricks that + + align:start position:0% +effects have been created by tricks that + + + align:start position:0% +effects have been created by tricks that +there's a that there's back projection + + align:start position:0% +there's a that there's back projection + + + align:start position:0% +there's a that there's back projection +going used in that it's it looks crude + + align:start position:0% +going used in that it's it looks crude + + + align:start position:0% +going used in that it's it looks crude +to us we can see through it but the + + align:start position:0% +to us we can see through it but the + + + align:start position:0% +to us we can see through it but the +early audiences would would not have + + align:start position:0% +early audiences would would not have + + + align:start position:0% +early audiences would would not have +recognized that we we we're so used to + + align:start position:0% +recognized that we we we're so used to + + + align:start position:0% +recognized that we we we're so used to +location filming that we can pick out uh + + align:start position:0% +location filming that we can pick out uh + + + align:start position:0% +location filming that we can pick out uh +we today can see through the process + + align:start position:0% +we today can see through the process + + + align:start position:0% +we today can see through the process +shots of earlier films this in fact + + align:start position:0% +shots of earlier films this in fact + + + align:start position:0% +shots of earlier films this in fact +damages some of Hitchcock's films very + + align:start position:0% +damages some of Hitchcock's films very + + + align:start position:0% +damages some of Hitchcock's films very +badly today because Hitchcock used a lot + + align:start position:0% +badly today because Hitchcock used a lot + + + align:start position:0% +badly today because Hitchcock used a lot +of processed shot effects in his films + + align:start position:0% +of processed shot effects in his films + + + align:start position:0% +of processed shot effects in his films +when he made them the audiences were + + align:start position:0% +when he made them the audiences were + + + align:start position:0% +when he made them the audiences were +used to there was a Convention of film + + align:start position:0% +used to there was a Convention of film + + + align:start position:0% +used to there was a Convention of film +going today everything because cameras + + align:start position:0% +going today everything because cameras + + + align:start position:0% +going today everything because cameras +are so much more more mobile and light + + align:start position:0% +are so much more more mobile and light + + + align:start position:0% +are so much more more mobile and light +and so so much has been uh learned about + + align:start position:0% +and so so much has been uh learned about + + + align:start position:0% +and so so much has been uh learned about +how to even about filming in in low + + align:start position:0% +how to even about filming in in low + + + align:start position:0% +how to even about filming in in low +light and so forth that they + + align:start position:0% +light and so forth that they + + + align:start position:0% +light and so forth that they +that there's much less use of process + + align:start position:0% +that there's much less use of process + + + align:start position:0% +that there's much less use of process +shots so well a new kind of process shot + + align:start position:0% +shots so well a new kind of process shot + + + align:start position:0% +shots so well a new kind of process shot +I suppose is emerging with digital + + align:start position:0% +I suppose is emerging with digital + + + align:start position:0% +I suppose is emerging with digital +animation and one could say it's sort of + + align:start position:0% +animation and one could say it's sort of + + + align:start position:0% +animation and one could say it's sort of +a return to the idea of manipulating the + + align:start position:0% +a return to the idea of manipulating the + + + align:start position:0% +a return to the idea of manipulating the +image in illegitimate ways um but the + + align:start position:0% +image in illegitimate ways um but the + + + align:start position:0% +image in illegitimate ways um but the +but but we can see even in The Great + + align:start position:0% +but but we can see even in The Great + + + align:start position:0% +but but we can see even in The Great +Train Robbery we we we can even see the + + align:start position:0% +Train Robbery we we we can even see the + + + align:start position:0% +Train Robbery we we we can even see the +beginnings of the use of process shots + + align:start position:0% +beginnings of the use of process shots + + + align:start position:0% +beginnings of the use of process shots +of recognizing that you can create + + align:start position:0% +of recognizing that you can create + + + align:start position:0% +of recognizing that you can create +effects in the movies that are unique + + align:start position:0% +effects in the movies that are unique + + + align:start position:0% +effects in the movies that are unique +and special that no other medium would + + align:start position:0% +and special that no other medium would + + + align:start position:0% +and special that no other medium would +allow you to do and what's embedded + + align:start position:0% +allow you to do and what's embedded + + + align:start position:0% +allow you to do and what's embedded +there is science fiction what's embedded + + align:start position:0% +there is science fiction what's embedded + + + align:start position:0% +there is science fiction what's embedded +there are all the kinds of imaginative + + align:start position:0% +there are all the kinds of imaginative + + + align:start position:0% +there are all the kinds of imaginative +not just science fiction all the kinds + + align:start position:0% +not just science fiction all the kinds + + + align:start position:0% +not just science fiction all the kinds +of imaginative movies that have been + + align:start position:0% +of imaginative movies that have been + + + align:start position:0% +of imaginative movies that have been +made that maybe take you inside people's + + align:start position:0% +made that maybe take you inside people's + + + align:start position:0% +made that maybe take you inside people's +nightmares or dreams where what the film + + align:start position:0% +nightmares or dreams where what the film + + + align:start position:0% +nightmares or dreams where what the film +is showing you now what in other words + + align:start position:0% +is showing you now what in other words + + + align:start position:0% +is showing you now what in other words +what what is embedded in that process + + align:start position:0% +what what is embedded in that process + + + align:start position:0% +what what is embedded in that process +shot even more fully embedded in in + + align:start position:0% +shot even more fully embedded in in + + + align:start position:0% +shot even more fully embedded in in +meles's the French directors films like + + align:start position:0% +meles's the French directors films like + + + align:start position:0% +meles's the French directors films like +trip to the moon where he explicitly + + align:start position:0% +trip to the moon where he explicitly + + + align:start position:0% +trip to the moon where he explicitly +goes into a realm of + + align:start position:0% +goes into a realm of + + + align:start position:0% +goes into a realm of +fantasy is not only that the film is the + + align:start position:0% +fantasy is not only that the film is the + + + align:start position:0% +fantasy is not only that the film is the +most profoundly realistic medium that + + align:start position:0% +most profoundly realistic medium that + + + align:start position:0% +most profoundly realistic medium that +was ever invented it may also be the + + align:start position:0% +was ever invented it may also be the + + + align:start position:0% +was ever invented it may also be the +most the the the the most expressive + + align:start position:0% +most the the the the most expressive + + + align:start position:0% +most the the the the most expressive +medium for the for the rendering of + + align:start position:0% +medium for the for the rendering of + + + align:start position:0% +medium for the for the rendering of +non-realistic states of dream of + + align:start position:0% +non-realistic states of dream of + + + align:start position:0% +non-realistic states of dream of +nightmare of fantasy uh exactly be + + align:start position:0% +nightmare of fantasy uh exactly be + + + align:start position:0% +nightmare of fantasy uh exactly be +because of the freedom that that uh the + + align:start position:0% +because of the freedom that that uh the + + + align:start position:0% +because of the freedom that that uh the +film medium allows and it even these + + align:start position:0% +film medium allows and it even these + + + align:start position:0% +film medium allows and it even these +implications are at least embedded in + + align:start position:0% +implications are at least embedded in + + + align:start position:0% +implications are at least embedded in +the use of the process shots in uh + + align:start position:0% +the use of the process shots in uh + + + align:start position:0% +the use of the process shots in uh +Porters The Great Train Robbery the the + + align:start position:0% +Porters The Great Train Robbery the the + + + align:start position:0% +Porters The Great Train Robbery the the +the other short that you're going to see + + align:start position:0% +the other short that you're going to see + + + align:start position:0% +the other short that you're going to see +tonight that is not by Keaton is called + + align:start position:0% +tonight that is not by Keaton is called + + + align:start position:0% +tonight that is not by Keaton is called +the lone Dale operator it's it's it was + + align:start position:0% +the lone Dale operator it's it's it was + + + align:start position:0% +the lone Dale operator it's it's it was +made in + + align:start position:0% +made in + + + align:start position:0% +made in +1911 um and uh it in a way it's the most + + align:start position:0% +1911 um and uh it in a way it's the most + + + align:start position:0% +1911 um and uh it in a way it's the most +it's the most advanced film of its time + + align:start position:0% +it's the most advanced film of its time + + + align:start position:0% +it's the most advanced film of its time +and that that's one re and I what I hope + + align:start position:0% +and that that's one re and I what I hope + + + align:start position:0% +and that that's one re and I what I hope +when you look at it you you'll watch + + align:start position:0% +when you look at it you you'll watch + + + align:start position:0% +when you look at it you you'll watch +especially for how much more complex it + + align:start position:0% +especially for how much more complex it + + + align:start position:0% +especially for how much more complex it +is than let's say The Great Train + + align:start position:0% +is than let's say The Great Train + + + align:start position:0% +is than let's say The Great Train +Robbery and it'll be a kind of small + + align:start position:0% +Robbery and it'll be a kind of small + + + align:start position:0% +Robbery and it'll be a kind of small +measure of this treed out principle I've + + align:start position:0% +measure of this treed out principle I've + + + align:start position:0% +measure of this treed out principle I've +been talking about let me mention a + + align:start position:0% +been talking about let me mention a + + + align:start position:0% +been talking about let me mention a +couple of things about uh the Londale + + align:start position:0% +couple of things about uh the Londale + + + align:start position:0% +couple of things about uh the Londale +operator between 1907 and 1911 most + + align:start position:0% +operator between 1907 and 1911 most + + + align:start position:0% +operator between 1907 and 1911 most +films consisted of no more than 24 + + align:start position:0% +films consisted of no more than 24 + + + align:start position:0% +films consisted of no more than 24 +separate shots right between 1908 and + + align:start position:0% +separate shots right between 1908 and + + + align:start position:0% +separate shots right between 1908 and +1913 led by DW Griffith and his company + + align:start position:0% +1913 led by DW Griffith and his company + + + align:start position:0% +1913 led by DW Griffith and his company +the Biograph company many more shots + + align:start position:0% +the Biograph company many more shots + + + align:start position:0% +the Biograph company many more shots +were introduced into in into a single + + align:start position:0% +were introduced into in into a single + + + align:start position:0% +were introduced into in into a single +reel of film and in the lone Dale + + align:start position:0% +reel of film and in the lone Dale + + + align:start position:0% +reel of film and in the lone Dale +operator there are 98 shots six + + align:start position:0% +operator there are 98 shots six + + + align:start position:0% +operator there are 98 shots six +intertitles one main title and two + + align:start position:0% +intertitles one main title and two + + + align:start position:0% +intertitles one main title and two +written inserts all within a 17-minute + + align:start position:0% +written inserts all within a 17-minute + + + align:start position:0% +written inserts all within a 17-minute +length but think of the just the ad the + + align:start position:0% +length but think of the just the ad the + + + align:start position:0% +length but think of the just the ad the +the access of complexity that has + + align:start position:0% +the access of complexity that has + + + align:start position:0% +the access of complexity that has +occurred just in less than 10 years + + align:start position:0% +occurred just in less than 10 years + + + align:start position:0% +occurred just in less than 10 years +right uh + + align:start position:0% +right uh + + + align:start position:0% +right uh +um it's such a complicated film that one + + align:start position:0% +um it's such a complicated film that one + + + align:start position:0% +um it's such a complicated film that one +of the things we realize even looking at + + align:start position:0% +of the things we realize even looking at + + + align:start position:0% +of the things we realize even looking at +it if we look closely is that it + + align:start position:0% +it if we look closely is that it + + + align:start position:0% +it if we look closely is that it +actually required uh a kind of + + align:start position:0% +actually required uh a kind of + + + align:start position:0% +actually required uh a kind of +attentiveness that earlier films did not + + align:start position:0% +attentiveness that earlier films did not + + + align:start position:0% +attentiveness that earlier films did not +as filmmakers began to make these things + + align:start position:0% +as filmmakers began to make these things + + + align:start position:0% +as filmmakers began to make these things +and began to make them longer and began + + align:start position:0% +and began to make them longer and began + + + align:start position:0% +and began to make them longer and began +to make them more complicated they + + align:start position:0% +to make them more complicated they + + + align:start position:0% +to make them more complicated they +realized that they couldn't just bring + + align:start position:0% +realized that they couldn't just bring + + + align:start position:0% +realized that they couldn't just bring +the camera out and start shooting they + + align:start position:0% +the camera out and start shooting they + + + align:start position:0% +the camera out and start shooting they +began to develop the the the formal + + align:start position:0% +began to develop the the the formal + + + align:start position:0% +began to develop the the the formal +rationalizing strategies that led to the + + align:start position:0% +rationalizing strategies that led to the + + + align:start position:0% +rationalizing strategies that led to the +making of movies as we understand them + + align:start position:0% +making of movies as we understand them + + + align:start position:0% +making of movies as we understand them +there was a 4-day shooting schedule + + align:start position:0% +there was a 4-day shooting schedule + + + align:start position:0% +there was a 4-day shooting schedule +created for the Londale operator it was + + align:start position:0% +created for the Londale operator it was + + + align:start position:0% +created for the Londale operator it was +one of the first films to to to have uh + + align:start position:0% +one of the first films to to to have uh + + + align:start position:0% +one of the first films to to to have uh +this format and of course it's the + + align:start position:0% +this format and of course it's the + + + align:start position:0% +this format and of course it's the +format that is followed today with + + align:start position:0% +format that is followed today with + + + align:start position:0% +format that is followed today with +virtually every film uh in in in + + align:start position:0% +virtually every film uh in in in + + + align:start position:0% +virtually every film uh in in in +different in different uh aspects um uh + + align:start position:0% +different in different uh aspects um uh + + + align:start position:0% +different in different uh aspects um uh +and this also required a pre-planned + + align:start position:0% +and this also required a pre-planned + + + align:start position:0% +and this also required a pre-planned +shooting script A they had to they had + + align:start position:0% +shooting script A they had to they had + + + align:start position:0% +shooting script A they had to they had +to plan what they would pre plan all of + + align:start position:0% +to plan what they would pre plan all of + + + align:start position:0% +to plan what they would pre plan all of +their shooting all of their shots all of + + align:start position:0% +their shooting all of their shots all of + + + align:start position:0% +their shooting all of their shots all of +their camera angles they needed a + + align:start position:0% +their camera angles they needed a + + + align:start position:0% +their camera angles they needed a +shooting script a written script films + + align:start position:0% +shooting script a written script films + + + align:start position:0% +shooting script a written script films +didn't have written scripts at first but + + align:start position:0% +didn't have written scripts at first but + + + align:start position:0% +didn't have written scripts at first but +Londale did uh and it also required in + + align:start position:0% +Londale did uh and it also required in + + + align:start position:0% +Londale did uh and it also required in +order for them to make their schedule + + align:start position:0% +order for them to make their schedule + + + align:start position:0% +order for them to make their schedule +outof order shooting that is to say they + + align:start position:0% +outof order shooting that is to say they + + + align:start position:0% +outof order shooting that is to say they +had to shoot certain things not in the + + align:start position:0% +had to shoot certain things not in the + + + align:start position:0% +had to shoot certain things not in the +sequential order of the film and that's + + align:start position:0% +sequential order of the film and that's + + + align:start position:0% +sequential order of the film and that's +one of the most basic principles of film + + align:start position:0% +one of the most basic principles of film + + + align:start position:0% +one of the most basic principles of film +making because once you set up the + + align:start position:0% +making because once you set up the + + + align:start position:0% +making because once you set up the +camera for a for a a shot of a + + align:start position:0% +camera for a for a a shot of a + + + align:start position:0% +camera for a for a a shot of a +particular environment if that + + align:start position:0% +particular environment if that + + + align:start position:0% +particular environment if that +environment shows up later in the film + + align:start position:0% +environment shows up later in the film + + + align:start position:0% +environment shows up later in the film +it's unbelievably more expensive than + + align:start position:0% +it's unbelievably more expensive than + + + align:start position:0% +it's unbelievably more expensive than +timec consuming to reconstitute that + + align:start position:0% +timec consuming to reconstitute that + + + align:start position:0% +timec consuming to reconstitute that +whole set so the the B almost all films + + align:start position:0% +whole set so the the B almost all films + + + align:start position:0% +whole set so the the B almost all films +to this very day are still shot out of + + align:start position:0% +to this very day are still shot out of + + + align:start position:0% +to this very day are still shot out of +sequence in order to maximize the the uh + + align:start position:0% +sequence in order to maximize the the uh + + + align:start position:0% +sequence in order to maximize the the uh +uh the the the the the time you have in + + align:start position:0% +uh the the the the the time you have in + + + align:start position:0% +uh the the the the the time you have in +in order to work at your most efficient + + align:start position:0% +in order to work at your most efficient + + + align:start position:0% +in order to work at your most efficient +and was it's not an efficient way to + + align:start position:0% +and was it's not an efficient way to + + + align:start position:0% +and was it's not an efficient way to +make a movie to shoot it sequentially to + + align:start position:0% +make a movie to shoot it sequentially to + + + align:start position:0% +make a movie to shoot it sequentially to +follow the to follow the script in its + + align:start position:0% +follow the to follow the script in its + + + align:start position:0% +follow the to follow the script in its +chronological sequence uh and the lone + + align:start position:0% +chronological sequence uh and the lone + + + align:start position:0% +chronological sequence uh and the lone +Dale operator is one of the is maybe the + + align:start position:0% +Dale operator is one of the is maybe the + + + align:start position:0% +Dale operator is one of the is maybe the +first film to to have all of these + + align:start position:0% +first film to to have all of these + + + align:start position:0% +first film to to have all of these +features that we would associate with + + align:start position:0% +features that we would associate with + + + align:start position:0% +features that we would associate with +with uh W with a mo with a modern or a + + align:start position:0% +with uh W with a mo with a modern or a + + + align:start position:0% +with uh W with a mo with a modern or a +contemporary film uh you might notice in + + align:start position:0% +contemporary film uh you might notice in + + + align:start position:0% +contemporary film uh you might notice in +the it's a it's an immensely complex + + align:start position:0% +the it's a it's an immensely complex + + + align:start position:0% +the it's a it's an immensely complex +film even in terms of its content and I + + align:start position:0% +film even in terms of its content and I + + + align:start position:0% +film even in terms of its content and I +might leave that I I won't talk about + + align:start position:0% +might leave that I I won't talk about + + + align:start position:0% +might leave that I I won't talk about +that much now except to say this watch + + align:start position:0% +that much now except to say this watch + + + align:start position:0% +that much now except to say this watch +the way in which the film tries to deal + + align:start position:0% +the way in which the film tries to deal + + + align:start position:0% +the way in which the film tries to deal +with what we might call uh hierarchies + + align:start position:0% +with what we might call uh hierarchies + + + align:start position:0% +with what we might call uh hierarchies +of gender I mean the film is partly + + align:start position:0% +of gender I mean the film is partly + + + align:start position:0% +of gender I mean the film is partly +about how a woman takes on a man's job + + align:start position:0% +about how a woman takes on a man's job + + + align:start position:0% +about how a woman takes on a man's job +mean her I guess it's her father isn't + + align:start position:0% +mean her I guess it's her father isn't + + + align:start position:0% +mean her I guess it's her father isn't +it her father is ill and she has to take + + align:start position:0% +it her father is ill and she has to take + + + align:start position:0% +it her father is ill and she has to take +over running the the train station and + + align:start position:0% +over running the the train station and + + + align:start position:0% +over running the the train station and +she run runs in and and so there's a + + align:start position:0% +she run runs in and and so there's a + + + align:start position:0% +she run runs in and and so there's a +certain sense in which one of the things + + align:start position:0% +certain sense in which one of the things + + + align:start position:0% +certain sense in which one of the things +that's dramatized socially is is a woman + + align:start position:0% +that's dramatized socially is is a woman + + + align:start position:0% +that's dramatized socially is is a woman +sort of moving into a kind of masculine + + align:start position:0% +sort of moving into a kind of masculine + + + align:start position:0% +sort of moving into a kind of masculine +realm taking on a role that's more + + align:start position:0% +realm taking on a role that's more + + + align:start position:0% +realm taking on a role that's more +aggressive than is appropriate for for + + align:start position:0% +aggressive than is appropriate for for + + + align:start position:0% +aggressive than is appropriate for for +the for the gender ideologies that are + + align:start position:0% +the for the gender ideologies that are + + + align:start position:0% +the for the gender ideologies that are +dominant at the end of the 19th century + + align:start position:0% +dominant at the end of the 19th century + + + align:start position:0% +dominant at the end of the 19th century +in the United States but the film is + + align:start position:0% +in the United States but the film is + + + align:start position:0% +in the United States but the film is +pretty clever about this like many such + + align:start position:0% +pretty clever about this like many such + + + align:start position:0% +pretty clever about this like many such +popular texts because although it does + + align:start position:0% +popular texts because although it does + + + align:start position:0% +popular texts because although it does +Grant this woman a certain kind of + + align:start position:0% +Grant this woman a certain kind of + + + align:start position:0% +Grant this woman a certain kind of +masculine Authority and competence it + + align:start position:0% +masculine Authority and competence it + + + align:start position:0% +masculine Authority and competence it +also has other things in the film that + + align:start position:0% +also has other things in the film that + + + align:start position:0% +also has other things in the film that +balance that that remind us that she is + + align:start position:0% +balance that that remind us that she is + + + align:start position:0% +balance that that remind us that she is +still nonetheless uh a weak vessel that + + align:start position:0% +still nonetheless uh a weak vessel that + + + align:start position:0% +still nonetheless uh a weak vessel that +she is still a damsel in distress like + + align:start position:0% +she is still a damsel in distress like + + + align:start position:0% +she is still a damsel in distress like +the typical Victorian construction of + + align:start position:0% +the typical Victorian construction of + + + align:start position:0% +the typical Victorian construction of +women uh in words what you can see is + + align:start position:0% +women uh in words what you can see is + + + align:start position:0% +women uh in words what you can see is +that the movie exhibits an anxiety about + + align:start position:0% +that the movie exhibits an anxiety about + + + align:start position:0% +that the movie exhibits an anxiety about +gender roles that's also an anxiety + + align:start position:0% +gender roles that's also an anxiety + + + align:start position:0% +gender roles that's also an anxiety +that's resident in the society itself uh + + align:start position:0% +that's resident in the society itself uh + + + align:start position:0% +that's resident in the society itself uh +and I I won't talk more about this now + + align:start position:0% +and I I won't talk more about this now + + + align:start position:0% +and I I won't talk more about this now +it's something we will develop this + + align:start position:0% +it's something we will develop this + + + align:start position:0% +it's something we will develop this +aspect of the movies the movies as a + + align:start position:0% +aspect of the movies the movies as a + + + align:start position:0% +aspect of the movies the movies as a +reflection of social anxieties and + + align:start position:0% +reflection of social anxieties and + + + align:start position:0% +reflection of social anxieties and +social and social problems as the as the + + align:start position:0% +social and social problems as the as the + + + align:start position:0% +social and social problems as the as the +course goes on but I do want to call + + align:start position:0% +course goes on but I do want to call + + + align:start position:0% +course goes on but I do want to call +your attention to certain technical + + align:start position:0% +your attention to certain technical + + + align:start position:0% +your attention to certain technical +things that you can watch for to at + + align:start position:0% +things that you can watch for to at + + + align:start position:0% +things that you can watch for to at +least one technical item in the film it + + align:start position:0% +least one technical item in the film it + + + align:start position:0% +least one technical item in the film it +it contains what might be called rhyming + + align:start position:0% +it contains what might be called rhyming + + + align:start position:0% +it contains what might be called rhyming +scenes in which at one point in the film + + align:start position:0% +scenes in which at one point in the film + + + align:start position:0% +scenes in which at one point in the film +you'll see a sequence of scenes in a + + align:start position:0% +you'll see a sequence of scenes in a + + + align:start position:0% +you'll see a sequence of scenes in a +particular shot and then later in the + + align:start position:0% +particular shot and then later in the + + + align:start position:0% +particular shot and then later in the +film almost exactly the same shot will + + align:start position:0% +film almost exactly the same shot will + + + align:start position:0% +film almost exactly the same shot will +reappear and the effect of this of + + align:start position:0% +reappear and the effect of this of + + + align:start position:0% +reappear and the effect of this of +course is to create a sense of coherence + + align:start position:0% +course is to create a sense of coherence + + + align:start position:0% +course is to create a sense of coherence +and a sense of familiarity in the + + align:start position:0% +and a sense of familiarity in the + + + align:start position:0% +and a sense of familiarity in the +audience it's actually a very subtle and + + align:start position:0% +audience it's actually a very subtle and + + + align:start position:0% +audience it's actually a very subtle and +careful strategy that Griffith himself + + align:start position:0% +careful strategy that Griffith himself + + + align:start position:0% +careful strategy that Griffith himself +devised uh it creates a kind of + + align:start position:0% +devised uh it creates a kind of + + + align:start position:0% +devised uh it creates a kind of +continuity and Clarity to the whole film + + align:start position:0% +continuity and Clarity to the whole film + + + align:start position:0% +continuity and Clarity to the whole film +watch for example how the doorway to the + + align:start position:0% +watch for example how the doorway to the + + + align:start position:0% +watch for example how the doorway to the +Londale station is photographed when you + + align:start position:0% +Londale station is photographed when you + + + align:start position:0% +Londale station is photographed when you +first see it how this image anchors the + + align:start position:0% +first see it how this image anchors the + + + align:start position:0% +first see it how this image anchors the +film's spatial relationships and how the + + align:start position:0% +film's spatial relationships and how the + + + align:start position:0% +film's spatial relationships and how the +film has a certain trajectory of + + align:start position:0% +film has a certain trajectory of + + + align:start position:0% +film has a certain trajectory of +movement that is repeated as the film + + align:start position:0% +movement that is repeated as the film + + + align:start position:0% +movement that is repeated as the film +goes on so that for example early in the + + align:start position:0% +goes on so that for example early in the + + + align:start position:0% +goes on so that for example early in the +film we see the heroin go from the + + align:start position:0% +film we see the heroin go from the + + + align:start position:0% +film we see the heroin go from the +exterior to the interior of the ticket + + align:start position:0% +exterior to the interior of the ticket + + + align:start position:0% +exterior to the interior of the ticket +office and then to the inner Office of + + align:start position:0% +office and then to the inner Office of + + + align:start position:0% +office and then to the inner Office of +the telegraph operator and we see her do + + align:start position:0% +the telegraph operator and we see her do + + + align:start position:0% +the telegraph operator and we see her do +this right and then this sets up a kind + + align:start position:0% +this right and then this sets up a kind + + + align:start position:0% +this right and then this sets up a kind +of basic location and basic action for + + align:start position:0% +of basic location and basic action for + + + align:start position:0% +of basic location and basic action for +the entire film it's as if what happens + + align:start position:0% +the entire film it's as if what happens + + + align:start position:0% +the entire film it's as if what happens +in that moment sets up creates a + + align:start position:0% +in that moment sets up creates a + + + align:start position:0% +in that moment sets up creates a +familiarity with the for the audience + + align:start position:0% +familiarity with the for the audience + + + align:start position:0% +familiarity with the for the audience +with the sort of geography of the movie + + align:start position:0% +with the sort of geography of the movie + + + align:start position:0% +with the sort of geography of the movie +because a lot of the action then will + + align:start position:0% +because a lot of the action then will + + + align:start position:0% +because a lot of the action then will +depend on our understanding of that + + align:start position:0% +depend on our understanding of that + + + align:start position:0% +depend on our understanding of that +geography and then there are at least + + align:start position:0% +geography and then there are at least + + + align:start position:0% +geography and then there are at least +four different times that Griffith + + align:start position:0% +four different times that Griffith + + + align:start position:0% +four different times that Griffith +repeats that basic three shot trajectory + + align:start position:0% +repeats that basic three shot trajectory + + + align:start position:0% +repeats that basic three shot trajectory +from the um exterior to the interior of + + align:start position:0% +from the um exterior to the interior of + + + align:start position:0% +from the um exterior to the interior of +the ticket office and then from the + + align:start position:0% +the ticket office and then from the + + + align:start position:0% +the ticket office and then from the +inner to the inner Office of the + + align:start position:0% +inner to the inner Office of the + + + align:start position:0% +inner to the inner Office of the +telegraph operator it happens four times + + align:start position:0% +telegraph operator it happens four times + + + align:start position:0% +telegraph operator it happens four times +in the film so it so the film has a kind + + align:start position:0% +in the film so it so the film has a kind + + + align:start position:0% +in the film so it so the film has a kind +of visual coherence by the time you come + + align:start position:0% +of visual coherence by the time you come + + + align:start position:0% +of visual coherence by the time you come +to it the third or fourth time it's as + + align:start position:0% +to it the third or fourth time it's as + + + align:start position:0% +to it the third or fourth time it's as +if you intimate with the physical + + align:start position:0% +if you intimate with the physical + + + align:start position:0% +if you intimate with the physical +geography of the movie This is actually + + align:start position:0% +geography of the movie This is actually + + + align:start position:0% +geography of the movie This is actually +a structural feature that it's easy to + + align:start position:0% +a structural feature that it's easy to + + + align:start position:0% +a structural feature that it's easy to +miss it but it's it it's actually very + + align:start position:0% +miss it but it's it it's actually very + + + align:start position:0% +miss it but it's it it's actually very +Artful and we can see it's a it's a mark + + align:start position:0% +Artful and we can see it's a it's a mark + + + align:start position:0% +Artful and we can see it's a it's a mark +of how far film has come even by 1911 + + align:start position:0% +of how far film has come even by 1911 + + + align:start position:0% +of how far film has come even by 1911 +this level of attentiveness uh is is + + align:start position:0% +this level of attentiveness uh is is + + + align:start position:0% +this level of attentiveness uh is is +available to us in the film there's much + + align:start position:0% +available to us in the film there's much + + + align:start position:0% +available to us in the film there's much +more that could be said about the lone + + align:start position:0% +more that could be said about the lone + + + align:start position:0% +more that could be said about the lone +Dale operator but I will leave it to + + align:start position:0% +Dale operator but I will leave it to + + + align:start position:0% +Dale operator but I will leave it to +your intelligence and your attentiveness + + align:start position:0% +your intelligence and your attentiveness + + + align:start position:0% +your intelligence and your attentiveness +to try to pick out more thing and again + + align:start position:0% +to try to pick out more thing and again + + + align:start position:0% +to try to pick out more thing and again +we're only talking about a 17 minute a + + align:start position:0% +we're only talking about a 17 minute a + + + align:start position:0% +we're only talking about a 17 minute a +17-minute film well + + align:start position:0% +17-minute film well + + + align:start position:0% +17-minute film well +uh Buster Keaton's career could be said + + align:start position:0% +uh Buster Keaton's career could be said + + + align:start position:0% +uh Buster Keaton's career could be said +in some degree to enact in small the + + align:start position:0% +in some degree to enact in small the + + + align:start position:0% +in some degree to enact in small the +larger processes I've been describing he + + align:start position:0% +larger processes I've been describing he + + + align:start position:0% +larger processes I've been describing he +comes into film late and in fact if we + + align:start position:0% +comes into film late and in fact if we + + + align:start position:0% +comes into film late and in fact if we +were working perfectly chronologically + + align:start position:0% +were working perfectly chronologically + + + align:start position:0% +were working perfectly chronologically +in terms of when chaplain became a + + align:start position:0% +in terms of when chaplain became a + + + align:start position:0% +in terms of when chaplain became a +director he would precede Katon but I've + + align:start position:0% +director he would precede Katon but I've + + + align:start position:0% +director he would precede Katon but I've +organized the film according to the + + align:start position:0% +organized the film according to the + + + align:start position:0% +organized the film according to the +feature the dates of the feature films + + align:start position:0% +feature the dates of the feature films + + + align:start position:0% +feature the dates of the feature films +and the general is an ear much a decade + + align:start position:0% +and the general is an ear much a decade + + + align:start position:0% +and the general is an ear much a decade +earlier than modern times which is the + + align:start position:0% +earlier than modern times which is the + + + align:start position:0% +earlier than modern times which is the +last quote silent film it's not really a + + align:start position:0% +last quote silent film it's not really a + + + align:start position:0% +last quote silent film it's not really a +silent film but it's the last silent + + align:start position:0% +silent film but it's the last silent + + + align:start position:0% +silent film but it's the last silent +film in a deep sense that was ever made + + align:start position:0% +film in a deep sense that was ever made + + + align:start position:0% +film in a deep sense that was ever made +it was made in the sound era in 1936 and + + align:start position:0% +it was made in the sound era in 1936 and + + + align:start position:0% +it was made in the sound era in 1936 and +when we next week we'll talk more about + + align:start position:0% +when we next week we'll talk more about + + + align:start position:0% +when we next week we'll talk more about +the implications of that and why that + + align:start position:0% +the implications of that and why that + + + align:start position:0% +the implications of that and why that +was a very daring thing for chaplain to + + align:start position:0% +was a very daring thing for chaplain to + + + align:start position:0% +was a very daring thing for chaplain to +to do something like almost a decade + + align:start position:0% +to do something like almost a decade + + + align:start position:0% +to do something like almost a decade +after the Advent of sound he made a + + align:start position:0% +after the Advent of sound he made a + + + align:start position:0% +after the Advent of sound he made a +movie that essentially had no dialogue + + align:start position:0% +movie that essentially had no dialogue + + + align:start position:0% +movie that essentially had no dialogue +in it and that recalled the silent film + + align:start position:0% +in it and that recalled the silent film + + + align:start position:0% +in it and that recalled the silent film +and everyone predicted that the film + + align:start position:0% +and everyone predicted that the film + + + align:start position:0% +and everyone predicted that the film +would be a flop that chaplain was M but + + align:start position:0% +would be a flop that chaplain was M but + + + align:start position:0% +would be a flop that chaplain was M but +of course they underestimated the + + align:start position:0% +of course they underestimated the + + + align:start position:0% +of course they underestimated the +affection and uh deep intimate Regard in + + align:start position:0% +affection and uh deep intimate Regard in + + + align:start position:0% +affection and uh deep intimate Regard in +which the in which the population of the + + align:start position:0% +which the in which the population of the + + + align:start position:0% +which the in which the population of the +world held the Charlie Chaplain + + align:start position:0% +world held the Charlie Chaplain + + + align:start position:0% +world held the Charlie Chaplain +character who by now was an icon more + + align:start position:0% +character who by now was an icon more + + + align:start position:0% +character who by now was an icon more +widely known in the world than any than + + align:start position:0% +widely known in the world than any than + + + align:start position:0% +widely known in the world than any than +any person in previous history I think + + align:start position:0% +any person in previous history I think + + + align:start position:0% +any person in previous history I think +even greater than more than Alexander + + align:start position:0% +even greater than more than Alexander + + + align:start position:0% +even greater than more than Alexander +the Great or any prior figure Charlie + + align:start position:0% +the Great or any prior figure Charlie + + + align:start position:0% +the Great or any prior figure Charlie +Chaplain was the first Global movie star + + align:start position:0% +Chaplain was the first Global movie star + + + align:start position:0% +Chaplain was the first Global movie star +was known virtually all over the world + + align:start position:0% +was known virtually all over the world + + + align:start position:0% +was known virtually all over the world +by the time he came to make modern times + + align:start position:0% +by the time he came to make modern times + + + align:start position:0% +by the time he came to make modern times +uh um um so Keaton came a little later + + align:start position:0% +uh um um so Keaton came a little later + + + align:start position:0% +uh um um so Keaton came a little later +comes into movie making uh after uh a + + align:start position:0% +comes into movie making uh after uh a + + + align:start position:0% +comes into movie making uh after uh a +little a few years after uh uh chaplain + + align:start position:0% +little a few years after uh uh chaplain + + + align:start position:0% +little a few years after uh uh chaplain +but his but his career has a similar + + align:start position:0% +but his but his career has a similar + + + align:start position:0% +but his but his career has a similar +trajectory he began his career in + + align:start position:0% +trajectory he began his career in + + + align:start position:0% +trajectory he began his career in +legitimate theater in Vaudeville and in + + align:start position:0% +legitimate theater in Vaudeville and in + + + align:start position:0% +legitimate theater in Vaudeville and in +and in and in on the performance circuit + + align:start position:0% +and in and in on the performance circuit + + + align:start position:0% +and in and in on the performance circuit +uh and and uh was an acrobat from a very + + align:start position:0% +uh and and uh was an acrobat from a very + + + align:start position:0% +uh and and uh was an acrobat from a very +young age from the age of two or three + + align:start position:0% +young age from the age of two or three + + + align:start position:0% +young age from the age of two or three +was in his parents stage act he was + + align:start position:0% +was in his parents stage act he was + + + align:start position:0% +was in his parents stage act he was +actually uh uh uh and in fact he learned + + align:start position:0% +actually uh uh uh and in fact he learned + + + align:start position:0% +actually uh uh uh and in fact he learned +a lot of his acrobatic Feats on his + + align:start position:0% +a lot of his acrobatic Feats on his + + + align:start position:0% +a lot of his acrobatic Feats on his +parents stage act one very famous uh + + align:start position:0% +parents stage act one very famous uh + + + align:start position:0% +parents stage act one very famous uh +passage in his his father used to take + + align:start position:0% +passage in his his father used to take + + + align:start position:0% +passage in his his father used to take +him he was just a young kid three or + + align:start position:0% +him he was just a young kid three or + + + align:start position:0% +him he was just a young kid three or +four years old five years old would take + + align:start position:0% +four years old five years old would take + + + align:start position:0% +four years old five years old would take +him by the legs and swing him back and + + align:start position:0% +him by the legs and swing him back and + + + align:start position:0% +him by the legs and swing him back and +forth like this he had very long hair + + align:start position:0% +forth like this he had very long hair + + + align:start position:0% +forth like this he had very long hair +and he would sweep the floor with his + + align:start position:0% +and he would sweep the floor with his + + + align:start position:0% +and he would sweep the floor with his +hair and then swing him two or three + + align:start position:0% +hair and then swing him two or three + + + align:start position:0% +hair and then swing him two or three +times this would happen live he would + + align:start position:0% +times this would happen live he would + + + align:start position:0% +times this would happen live he would +swing him like this and let him go and + + align:start position:0% +swing him like this and let him go and + + + align:start position:0% +swing him like this and let him go and +the kid 5 years old would fly against + + align:start position:0% +the kid 5 years old would fly against + + + align:start position:0% +the kid 5 years old would fly against +the wall and fall down it would look + + align:start position:0% +the wall and fall down it would look + + + align:start position:0% +the wall and fall down it would look +terrible and Keaton later in his life + + align:start position:0% +terrible and Keaton later in his life + + + align:start position:0% +terrible and Keaton later in his life +Katon talked about this there were + + align:start position:0% +Katon talked about this there were + + + align:start position:0% +Katon talked about this there were +actually some cities in which the the uh + + align:start position:0% +actually some cities in which the the uh + + + align:start position:0% +actually some cities in which the the uh +uh societies for the for for the + + align:start position:0% +uh societies for the for for the + + + align:start position:0% +uh societies for the for for the +Prevention of Cruelty to Children came + + align:start position:0% +Prevention of Cruelty to Children came + + + align:start position:0% +Prevention of Cruelty to Children came +in and shut down the shut down the ACT + + align:start position:0% +in and shut down the shut down the ACT + + + align:start position:0% +in and shut down the shut down the ACT +wouldn't allow the ACT to go on not + + align:start position:0% +wouldn't allow the ACT to go on not + + + align:start position:0% +wouldn't allow the ACT to go on not +stupid because his father was a drunkard + + align:start position:0% +stupid because his father was a drunkard + + + align:start position:0% +stupid because his father was a drunkard +and sometimes performed drunk and Keaton + + align:start position:0% +and sometimes performed drunk and Keaton + + + align:start position:0% +and sometimes performed drunk and Keaton +was sometimes injured he was also + + align:start position:0% +was sometimes injured he was also + + + align:start position:0% +was sometimes injured he was also +injured when he made his own movies for + + align:start position:0% +injured when he made his own movies for + + + align:start position:0% +injured when he made his own movies for +because he was such daring acrobat uh + + align:start position:0% +because he was such daring acrobat uh + + + align:start position:0% +because he was such daring acrobat uh +and uh Keaton recounts that when he + + align:start position:0% +and uh Keaton recounts that when he + + + align:start position:0% +and uh Keaton recounts that when he +first began to perform in this he would + + align:start position:0% +first began to perform in this he would + + + align:start position:0% +first began to perform in this he would +make faces you know faces that indicated + + align:start position:0% +make faces you know faces that indicated + + + align:start position:0% +make faces you know faces that indicated +pain or happiness or relief when his + + align:start position:0% +pain or happiness or relief when his + + + align:start position:0% +pain or happiness or relief when his +father was manipulating him this way but + + align:start position:0% +father was manipulating him this way but + + + align:start position:0% +father was manipulating him this way but +he found that the audience responded + + align:start position:0% +he found that the audience responded + + + align:start position:0% +he found that the audience responded +Much More comically Much More + + align:start position:0% +Much More comically Much More + + + align:start position:0% +Much More comically Much More +immediately if he just kept his face + + align:start position:0% +immediately if he just kept his face + + + align:start position:0% +immediately if he just kept his face +expressionless and that's where there + + align:start position:0% +expressionless and that's where there + + + align:start position:0% +expressionless and that's where there +developed the probably mistaken uh uh + + align:start position:0% +developed the probably mistaken uh uh + + + align:start position:0% +developed the probably mistaken uh uh +label for Katon of the great Stone face + + align:start position:0% +label for Katon of the great Stone face + + + align:start position:0% +label for Katon of the great Stone face +and in his films very often you'll see + + align:start position:0% +and in his films very often you'll see + + + align:start position:0% +and in his films very often you'll see +this young man facing Monumental + + align:start position:0% +this young man facing Monumental + + + align:start position:0% +this young man facing Monumental +catastrophe his face will look out at + + align:start position:0% +catastrophe his face will look out at + + + align:start position:0% +catastrophe his face will look out at +things without Ever Changing expression + + align:start position:0% +things without Ever Changing expression + + + align:start position:0% +things without Ever Changing expression +and there is something kind of kind of + + align:start position:0% +and there is something kind of kind of + + + align:start position:0% +and there is something kind of kind of +comical about that you'll see some + + align:start position:0% +comical about that you'll see some + + + align:start position:0% +comical about that you'll see some +examples of this in the in the general + + align:start position:0% +examples of this in the in the general + + + align:start position:0% +examples of this in the in the general +well you'll you'll see in the two short + + align:start position:0% +well you'll you'll see in the two short + + + align:start position:0% +well you'll you'll see in the two short +films that Keaton began to make that he + + align:start position:0% +films that Keaton began to make that he + + + align:start position:0% +films that Keaton began to make that he +enters film at already a relatively + + align:start position:0% +enters film at already a relatively + + + align:start position:0% +enters film at already a relatively +sophisticated time and and the shorts + + align:start position:0% +sophisticated time and and the shorts + + + align:start position:0% +sophisticated time and and the shorts +I'm asking you to look at are very + + align:start position:0% +I'm asking you to look at are very + + + align:start position:0% +I'm asking you to look at are very +interesting uh uh remarkable films in in + + align:start position:0% +interesting uh uh remarkable films in in + + + align:start position:0% +interesting uh uh remarkable films in in +their own way and one of the things they + + align:start position:0% +their own way and one of the things they + + + align:start position:0% +their own way and one of the things they +teach us and one of the reasons I want + + align:start position:0% +teach us and one of the reasons I want + + + align:start position:0% +teach us and one of the reasons I want +you to look closely at at at at uh + + align:start position:0% +you to look closely at at at at uh + + + align:start position:0% +you to look closely at at at at uh +Keaton is they is they show us yet again + + align:start position:0% +Keaton is they is they show us yet again + + + align:start position:0% +Keaton is they is they show us yet again +another aspect of what I mean when I + + align:start position:0% +another aspect of what I mean when I + + + align:start position:0% +another aspect of what I mean when I +talk about the Fred art principle this + + align:start position:0% +talk about the Fred art principle this + + + align:start position:0% +talk about the Fred art principle this +development of evolution and and and and + + align:start position:0% +development of evolution and and and and + + + align:start position:0% +development of evolution and and and and +and increasing and increasing complexity + + align:start position:0% +and increasing and increasing complexity + + + align:start position:0% +and increasing and increasing complexity +because if you look at cops or if you + + align:start position:0% +because if you look at cops or if you + + + align:start position:0% +because if you look at cops or if you +look at one week what you will see Katon + + align:start position:0% +look at one week what you will see Katon + + + align:start position:0% +look at one week what you will see Katon +doing in those films is learning how to + + align:start position:0% +doing in those films is learning how to + + + align:start position:0% +doing in those films is learning how to +link jokes together in some sort of a + + align:start position:0% +link jokes together in some sort of a + + + align:start position:0% +link jokes together in some sort of a +coherent way + + align:start position:0% +coherent way + + + align:start position:0% +coherent way +but the films and and there are + + align:start position:0% +but the films and and there are + + + align:start position:0% +but the films and and there are +wonderful coherent sequences in these + + align:start position:0% +wonderful coherent sequences in these + + + align:start position:0% +wonderful coherent sequences in these +films but still one doesn't feel that + + align:start position:0% +films but still one doesn't feel that + + + align:start position:0% +films but still one doesn't feel that +there's a real character in them that + + align:start position:0% +there's a real character in them that + + + align:start position:0% +there's a real character in them that +there's a sustained coherent uh + + align:start position:0% +there's a sustained coherent uh + + + align:start position:0% +there's a sustained coherent uh +fictional Universe being dramatized + + align:start position:0% +fictional Universe being dramatized + + + align:start position:0% +fictional Universe being dramatized +maybe in cops one does feel this there's + + align:start position:0% +maybe in cops one does feel this there's + + + align:start position:0% +maybe in cops one does feel this there's +much more sort of textural coherence in + + align:start position:0% +much more sort of textural coherence in + + + align:start position:0% +much more sort of textural coherence in +cops but what we can see Katon doing is + + align:start position:0% +cops but what we can see Katon doing is + + + align:start position:0% +cops but what we can see Katon doing is +beginning to move from the idea of a + + align:start position:0% +beginning to move from the idea of a + + + align:start position:0% +beginning to move from the idea of a +single joke to a sequence of jokes and + + align:start position:0% +single joke to a sequence of jokes and + + + align:start position:0% +single joke to a sequence of jokes and +then by the time we get to the general + + align:start position:0% +then by the time we get to the general + + + align:start position:0% +then by the time we get to the general +moving from a sequence of from a single + + align:start position:0% +moving from a sequence of from a single + + + align:start position:0% +moving from a sequence of from a single +joke to a sequence of jokes to a + + align:start position:0% +joke to a sequence of jokes to a + + + align:start position:0% +joke to a sequence of jokes to a +sustained narrative which incorporates + + align:start position:0% +sustained narrative which incorporates + + + align:start position:0% +sustained narrative which incorporates +within it various kinds of comical jokes + + align:start position:0% +within it various kinds of comical jokes + + + align:start position:0% +within it various kinds of comical jokes +and also sequence jokes because Keaton's + + align:start position:0% +and also sequence jokes because Keaton's + + + align:start position:0% +and also sequence jokes because Keaton's +best jokes are not single jokes at all + + align:start position:0% +best jokes are not single jokes at all + + + align:start position:0% +best jokes are not single jokes at all +not on liners but the the joke will be + + align:start position:0% +not on liners but the the joke will be + + + align:start position:0% +not on liners but the the joke will be +told again and again or what or really + + align:start position:0% +told again and again or what or really + + + align:start position:0% +told again and again or what or really +what will happen is he will do something + + align:start position:0% +what will happen is he will do something + + + align:start position:0% +what will happen is he will do something +he'll think how could and then he The + + align:start position:0% +he'll think how could and then he The + + + align:start position:0% +he'll think how could and then he The +Next Step will Top what he's done before + + align:start position:0% +Next Step will Top what he's done before + + + align:start position:0% +Next Step will Top what he's done before +and the next step will Top you think + + align:start position:0% +and the next step will Top you think + + + align:start position:0% +and the next step will Top you think +that he got to a point where it would be + + align:start position:0% +that he got to a point where it would be + + + align:start position:0% +that he got to a point where it would be +impossible to add another comic + + align:start position:0% +impossible to add another comic + + + align:start position:0% +impossible to add another comic +complication to what he's done when he + + align:start position:0% +complication to what he's done when he + + + align:start position:0% +complication to what he's done when he +of course does it uh and this becomes + + align:start position:0% +of course does it uh and this becomes + + + align:start position:0% +of course does it uh and this becomes +one of the deep principles of chaplain + + align:start position:0% +one of the deep principles of chaplain + + + align:start position:0% +one of the deep principles of chaplain +of of Keaton's comedy there are numerous + + align:start position:0% +of of Keaton's comedy there are numerous + + + align:start position:0% +of of Keaton's comedy there are numerous +examples of it in both the two shorts + + align:start position:0% +examples of it in both the two shorts + + + align:start position:0% +examples of it in both the two shorts +and in this in the longer film that I + + align:start position:0% +and in this in the longer film that I + + + align:start position:0% +and in this in the longer film that I +that uh the the general but let me + + align:start position:0% +that uh the the general but let me + + + align:start position:0% +that uh the the general but let me +mention an example from the general very + + align:start position:0% +mention an example from the general very + + + align:start position:0% +mention an example from the general very +early in the general there's a sequence + + align:start position:0% +early in the general there's a sequence + + + align:start position:0% +early in the general there's a sequence +it's probably the quintessential Katon + + align:start position:0% +it's probably the quintessential Katon + + + align:start position:0% +it's probably the quintessential Katon +sequence and I won't go into such detail + + align:start position:0% +sequence and I won't go into such detail + + + align:start position:0% +sequence and I won't go into such detail +as to spoil the film for you uh but let + + align:start position:0% +as to spoil the film for you uh but let + + + align:start position:0% +as to spoil the film for you uh but let +me just say it involves a Canon and it + + align:start position:0% +me just say it involves a Canon and it + + + align:start position:0% +me just say it involves a Canon and it +involves Katon uh who's chasing after + + align:start position:0% +involves Katon uh who's chasing after + + + align:start position:0% +involves Katon uh who's chasing after +Katon plays a uh the engineer of a of of + + align:start position:0% +Katon plays a uh the engineer of a of of + + + align:start position:0% +Katon plays a uh the engineer of a of of +a locomotive a locomotive engineer the + + align:start position:0% +a locomotive a locomotive engineer the + + + align:start position:0% +a locomotive a locomotive engineer the +general of the title is not a a a + + align:start position:0% +general of the title is not a a a + + + align:start position:0% +general of the title is not a a a +military General it's a locomotive the + + align:start position:0% +military General it's a locomotive the + + + align:start position:0% +military General it's a locomotive the +locomotive is called the general and + + align:start position:0% +locomotive is called the general and + + + align:start position:0% +locomotive is called the general and +this and the film recounts a + + align:start position:0% +this and the film recounts a + + + align:start position:0% +this and the film recounts a +historically true story of a of a time + + align:start position:0% +historically true story of a of a time + + + align:start position:0% +historically true story of a of a time +when the Union Army um he me uh that uh + + align:start position:0% +when the Union Army um he me uh that uh + + + align:start position:0% +when the Union Army um he me uh that uh +the Confederate Army uh the Union Army + + align:start position:0% +the Confederate Army uh the Union Army + + + align:start position:0% +the Confederate Army uh the Union Army +came into Confederate territory and + + align:start position:0% +came into Confederate territory and + + + align:start position:0% +came into Confederate territory and +stole a locomotive belonging to the + + align:start position:0% +stole a locomotive belonging to the + + + align:start position:0% +stole a locomotive belonging to the +Confederacy and this and and he was and + + align:start position:0% +Confederacy and this and and he was and + + + align:start position:0% +Confederacy and this and and he was and +Keaton in a comic vein retells retells + + align:start position:0% +Keaton in a comic vein retells retells + + + align:start position:0% +Keaton in a comic vein retells retells +this this story when you watch this + + align:start position:0% +this this story when you watch this + + + align:start position:0% +this this story when you watch this +Canon sequence you'll see exactly what I + + align:start position:0% +Canon sequence you'll see exactly what I + + + align:start position:0% +Canon sequence you'll see exactly what I +mean you'll and this sequence is at the + + align:start position:0% +mean you'll and this sequence is at the + + + align:start position:0% +mean you'll and this sequence is at the +heart of James AG's essay on the silent + + align:start position:0% +heart of James AG's essay on the silent + + + align:start position:0% +heart of James AG's essay on the silent +film comedy and when you read that essay + + align:start position:0% +film comedy and when you read that essay + + + align:start position:0% +film comedy and when you read that essay +you'll see even more clearly what I mean + + align:start position:0% +you'll see even more clearly what I mean + + + align:start position:0% +you'll see even more clearly what I mean +by a trajectory joke or a sequence joke + + align:start position:0% +by a trajectory joke or a sequence joke + + + align:start position:0% +by a trajectory joke or a sequence joke +which builds and builds and builds and + + align:start position:0% +which builds and builds and builds and + + + align:start position:0% +which builds and builds and builds and +keeps topping itself well this Canon + + align:start position:0% +keeps topping itself well this Canon + + + align:start position:0% +keeps topping itself well this Canon +sequence is a perfect example of that + + align:start position:0% +sequence is a perfect example of that + + + align:start position:0% +sequence is a perfect example of that +and it's a perfect example of it not + + align:start position:0% +and it's a perfect example of it not + + + align:start position:0% +and it's a perfect example of it not +only because we see the joke getting + + align:start position:0% +only because we see the joke getting + + + align:start position:0% +only because we see the joke getting +more complicated as it goes on but as + + align:start position:0% +more complicated as it goes on but as + + + align:start position:0% +more complicated as it goes on but as +the joke becomes more complicated + + align:start position:0% +the joke becomes more complicated + + + align:start position:0% +the joke becomes more complicated +something else happens + + align:start position:0% +something else happens + + + align:start position:0% +something else happens +the joke becomes more than a joke it + + align:start position:0% +the joke becomes more than a joke it + + + align:start position:0% +the joke becomes more than a joke it +becomes a kind of comment on experience + + align:start position:0% +becomes a kind of comment on experience + + + align:start position:0% +becomes a kind of comment on experience +it becomes a kind of comment on on on on + + align:start position:0% +it becomes a kind of comment on on on on + + + align:start position:0% +it becomes a kind of comment on on on on +on what life is like that is to say we + + align:start position:0% +on what life is like that is to say we + + + align:start position:0% +on what life is like that is to say we +move from something that simply makes us + + align:start position:0% +move from something that simply makes us + + + align:start position:0% +move from something that simply makes us +smile to something that makes us think + + align:start position:0% +smile to something that makes us think + + + align:start position:0% +smile to something that makes us think +about the world that comments on the + + align:start position:0% +about the world that comments on the + + + align:start position:0% +about the world that comments on the +world that imagines the world in a + + align:start position:0% +world that imagines the world in a + + + align:start position:0% +world that imagines the world in a +coherent way I'll try to be more + + align:start position:0% +coherent way I'll try to be more + + + align:start position:0% +coherent way I'll try to be more +explicit about this in a in a in in a + + align:start position:0% +explicit about this in a in a in in a + + + align:start position:0% +explicit about this in a in a in in a +moment so in Keaton's career we see him + + align:start position:0% +moment so in Keaton's career we see him + + + align:start position:0% +moment so in Keaton's career we see him +doing astonishing things as an acrobat + + align:start position:0% +doing astonishing things as an acrobat + + + align:start position:0% +doing astonishing things as an acrobat +and we would admire him just for + + align:start position:0% +and we would admire him just for + + + align:start position:0% +and we would admire him just for +acrobatic performances in these films + + align:start position:0% +acrobatic performances in these films + + + align:start position:0% +acrobatic performances in these films +watching this film in the in the general + + align:start position:0% +watching this film in the in the general + + + align:start position:0% +watching this film in the in the general +for example the way in which when he's + + align:start position:0% +for example the way in which when he's + + + align:start position:0% +for example the way in which when he's +piloting his locomotive chasing the + + align:start position:0% +piloting his locomotive chasing the + + + align:start position:0% +piloting his locomotive chasing the +people who have stolen his original + + align:start position:0% +people who have stolen his original + + + align:start position:0% +people who have stolen his original +locomotive how he's the only one on the + + align:start position:0% +locomotive how he's the only one on the + + + align:start position:0% +locomotive how he's the only one on the +train and he crawls all over the train + + align:start position:0% +train and he crawls all over the train + + + align:start position:0% +train and he crawls all over the train +he almost every while the train is + + align:start position:0% +he almost every while the train is + + + align:start position:0% +he almost every while the train is +running he'll crawl up to the front of + + align:start position:0% +running he'll crawl up to the front of + + + align:start position:0% +running he'll crawl up to the front of +it he'll run to the back of it to put + + align:start position:0% +it he'll run to the back of it to put + + + align:start position:0% +it he'll run to the back of it to put +more fuel in you what you can what you + + align:start position:0% +more fuel in you what you can what you + + + align:start position:0% +more fuel in you what you can what you +can see is and and also you can see this + + align:start position:0% +can see is and and also you can see this + + + align:start position:0% +can see is and and also you can see this +stuff happening in really happening it's + + align:start position:0% +stuff happening in really happening it's + + + align:start position:0% +stuff happening in really happening it's +not faked in any way because there's a + + align:start position:0% +not faked in any way because there's a + + + align:start position:0% +not faked in any way because there's a +there is a a camera following the train + + align:start position:0% +there is a a camera following the train + + + align:start position:0% +there is a a camera following the train +as it's moving you can see it's really + + align:start position:0% +as it's moving you can see it's really + + + align:start position:0% +as it's moving you can see it's really +moving because you can you can see it + + align:start position:0% +moving because you can you can see it + + + align:start position:0% +moving because you can you can see it +you can see it moving on the track and + + align:start position:0% +you can see it moving on the track and + + + align:start position:0% +you can see it moving on the track and +you can see the World Behind it and you + + align:start position:0% +you can see the World Behind it and you + + + align:start position:0% +you can see the World Behind it and you +can you can tell that Katon is not + + align:start position:0% +can you can tell that Katon is not + + + align:start position:0% +can you can tell that Katon is not +faking these effects well this Canon + + align:start position:0% +faking these effects well this Canon + + + align:start position:0% +faking these effects well this Canon +sequence is a is a is a sublimely rich + + align:start position:0% +sequence is a is a is a sublimely rich + + + align:start position:0% +sequence is a is a is a sublimely rich +example of this complex process I've + + align:start position:0% +example of this complex process I've + + + align:start position:0% +example of this complex process I've +been describing and it it has to do in + + align:start position:0% +been describing and it it has to do in + + + align:start position:0% +been describing and it it has to do in +part with what I call the multiplicity + + align:start position:0% +part with what I call the multiplicity + + + align:start position:0% +part with what I call the multiplicity +principle which I will Define in a + + align:start position:0% +principle which I will Define in a + + + align:start position:0% +principle which I will Define in a +moment so we see Katon as an actor as an + + align:start position:0% +moment so we see Katon as an actor as an + + + align:start position:0% +moment so we see Katon as an actor as an +acrobat as an acrobat actor as an + + align:start position:0% +acrobat as an acrobat actor as an + + + align:start position:0% +acrobat as an acrobat actor as an +incredibly in as a man much more than CH + + align:start position:0% +incredibly in as a man much more than CH + + + align:start position:0% +incredibly in as a man much more than CH +chaplain interested in the technology of + + align:start position:0% +chaplain interested in the technology of + + + align:start position:0% +chaplain interested in the technology of +Motion Pictures and of Cinema and you'll + + align:start position:0% +Motion Pictures and of Cinema and you'll + + + align:start position:0% +Motion Pictures and of Cinema and you'll +see a couple of examples in the films + + align:start position:0% +see a couple of examples in the films + + + align:start position:0% +see a couple of examples in the films +you're going to look at tonight in which + + align:start position:0% +you're going to look at tonight in which + + + align:start position:0% +you're going to look at tonight in which +we see Katon exploring uh in a somewhat + + align:start position:0% +we see Katon exploring uh in a somewhat + + + align:start position:0% +we see Katon exploring uh in a somewhat +systematic way the nature of the + + align:start position:0% +systematic way the nature of the + + + align:start position:0% +systematic way the nature of the +illusion of the Motion Pictures there's + + align:start position:0% +illusion of the Motion Pictures there's + + + align:start position:0% +illusion of the Motion Pictures there's +one remarkable moment comical moment in + + align:start position:0% +one remarkable moment comical moment in + + + align:start position:0% +one remarkable moment comical moment in +one week in which uh the heroin gets + + align:start position:0% +one week in which uh the heroin gets + + + align:start position:0% +one week in which uh the heroin gets +into a bathtub and it looks like you and + + align:start position:0% +into a bathtub and it looks like you and + + + align:start position:0% +into a bathtub and it looks like you and +she's sitting in the bathtub she's + + align:start position:0% +she's sitting in the bathtub she's + + + align:start position:0% +she's sitting in the bathtub she's +starting to get up and it looks like + + align:start position:0% +starting to get up and it looks like + + + align:start position:0% +starting to get up and it looks like +you're actually about to see some + + align:start position:0% +you're actually about to see some + + + align:start position:0% +you're actually about to see some +unmentioned able parts of her body and + + align:start position:0% +unmentioned able parts of her body and + + + align:start position:0% +unmentioned able parts of her body and +just as that's about to happen a hand + + align:start position:0% +just as that's about to happen a hand + + + align:start position:0% +just as that's about to happen a hand +comes in front of the camera and blocks + + align:start position:0% +comes in front of the camera and blocks + + + align:start position:0% +comes in front of the camera and blocks +you and it's actually a very disturbing + + align:start position:0% +you and it's actually a very disturbing + + + align:start position:0% +you and it's actually a very disturbing +moment in a way because it interrupts + + align:start position:0% +moment in a way because it interrupts + + + align:start position:0% +moment in a way because it interrupts +The Narrative flow it's it's a it's an + + align:start position:0% +The Narrative flow it's it's a it's an + + + align:start position:0% +The Narrative flow it's it's a it's an +intervention from the outside whose hand + + align:start position:0% +intervention from the outside whose hand + + + align:start position:0% +intervention from the outside whose hand +it is it's not a character in the film + + align:start position:0% +it is it's not a character in the film + + + align:start position:0% +it is it's not a character in the film +it's the director or so right it's very + + align:start position:0% +it's the director or so right it's very + + + align:start position:0% +it's the director or so right it's very +bold moment because what it does is it + + align:start position:0% +bold moment because what it does is it + + + align:start position:0% +bold moment because what it does is it +reminds you of the film as an artifact + + align:start position:0% +reminds you of the film as an artifact + + + align:start position:0% +reminds you of the film as an artifact +it reminds you that the film is uh an + + align:start position:0% +it reminds you that the film is uh an + + + align:start position:0% +it reminds you that the film is uh an +artifact in other words it's a moment of + + align:start position:0% +artifact in other words it's a moment of + + + align:start position:0% +artifact in other words it's a moment of +self-reflexiveness or self-consciousness + + align:start position:0% +self-reflexiveness or self-consciousness + + + align:start position:0% +self-reflexiveness or self-consciousness +that you would never see in a chaplain + + align:start position:0% +that you would never see in a chaplain + + + align:start position:0% +that you would never see in a chaplain +film but shows + + align:start position:0% +film but shows + + + align:start position:0% +film but shows +Keaton's astonishing interest in the + + align:start position:0% +Keaton's astonishing interest in the + + + align:start position:0% +Keaton's astonishing interest in the +technology of motion pictures uh I had + + align:start position:0% +technology of motion pictures uh I had + + + align:start position:0% +technology of motion pictures uh I had +many examples that Greg and I had ready + + align:start position:0% +many examples that Greg and I had ready + + + align:start position:0% +many examples that Greg and I had ready +but I don't have time to show them to + + align:start position:0% +but I don't have time to show them to + + + align:start position:0% +but I don't have time to show them to +you maybe you can put up while I'm + + align:start position:0% +you maybe you can put up while I'm + + + align:start position:0% +you maybe you can put up while I'm +talking the the playhouse one of his + + align:start position:0% +talking the the playhouse one of his + + + align:start position:0% +talking the the playhouse one of his +most famous examples of this is a film + + align:start position:0% +most famous examples of this is a film + + + align:start position:0% +most famous examples of this is a film +called the playhouse in which he ends up + + align:start position:0% +called the playhouse in which he ends up + + + align:start position:0% +called the playhouse in which he ends up +playing every role in the movie and the + + align:start position:0% +playing every role in the movie and the + + + align:start position:0% +playing every role in the movie and the +way he did this was incred was + + align:start position:0% +way he did this was incred was + + + align:start position:0% +way he did this was incred was +incredibly interesting he would shoot + + align:start position:0% +incredibly interesting he would shoot + + + align:start position:0% +incredibly interesting he would shoot +the film uh and then he he would shoot + + align:start position:0% +the film uh and then he he would shoot + + + align:start position:0% +the film uh and then he he would shoot +the film but he would but he put a he + + align:start position:0% +the film but he would but he put a he + + + align:start position:0% +the film but he would but he put a he +put masking tape over the lens of the + + align:start position:0% +put masking tape over the lens of the + + + align:start position:0% +put masking tape over the lens of the +camera and only one little tiny part of + + align:start position:0% +camera and only one little tiny part of + + + align:start position:0% +camera and only one little tiny part of +the of the lens of the camera was was + + align:start position:0% +the of the lens of the camera was was + + + align:start position:0% +the of the lens of the camera was was +would expose the film and he would he + + align:start position:0% +would expose the film and he would he + + + align:start position:0% +would expose the film and he would he +would shoot that then he would rewind + + align:start position:0% +would shoot that then he would rewind + + + align:start position:0% +would shoot that then he would rewind +the film and then if he were over in + + align:start position:0% +the film and then if he were over in + + + align:start position:0% +the film and then if he were over in +this corner for that shot then he'd move + + align:start position:0% +this corner for that shot then he'd move + + + align:start position:0% +this corner for that shot then he'd move +over and sit in the other corner he put + + align:start position:0% +over and sit in the other corner he put + + + align:start position:0% +over and sit in the other corner he put +a new kind of tape on the camera film it + + align:start position:0% +a new kind of tape on the camera film it + + + align:start position:0% +a new kind of tape on the camera film it +again and the film you're going to see + + align:start position:0% +again and the film you're going to see + + + align:start position:0% +again and the film you're going to see +will show this and you can see they're + + align:start position:0% +will show this and you can see they're + + + align:start position:0% +will show this and you can see they're +all Buster right it's a it's an it's a + + align:start position:0% +all Buster right it's a it's an it's a + + + align:start position:0% +all Buster right it's a it's an it's a +it's again what it shows is he's a + + align:start position:0% +it's again what it shows is he's a + + + align:start position:0% +it's again what it shows is he's a +technician he's interested in the + + align:start position:0% +technician he's interested in the + + + align:start position:0% +technician he's interested in the +technology of motion P of of of the of + + align:start position:0% +technology of motion P of of of the of + + + align:start position:0% +technology of motion P of of of the of +the uh motion picture camera and what + + align:start position:0% +the uh motion picture camera and what + + + align:start position:0% +the uh motion picture camera and what +kinds of manipulations are possible + + align:start position:0% +kinds of manipulations are possible + + + align:start position:0% +kinds of manipulations are possible +because he's the conductor right he's + + align:start position:0% +because he's the conductor right he's + + + align:start position:0% +because he's the conductor right he's +you'll as it turns out he's going to + + align:start position:0% +you'll as it turns out he's going to + + + align:start position:0% +you'll as it turns out he's going to +also end up being the the only person in + + align:start position:0% +also end up being the the only person in + + + align:start position:0% +also end up being the the only person in +the audience well um and then finally + + align:start position:0% +the audience well um and then finally + + + align:start position:0% +the audience well um and then finally +what what I've already implied is that + + align:start position:0% +what what I've already implied is that + + + align:start position:0% +what what I've already implied is that +Keaton's jokes and his technical + + align:start position:0% +Keaton's jokes and his technical + + + align:start position:0% +Keaton's jokes and his technical +interests also end up making him a + + align:start position:0% +interests also end up making him a + + + align:start position:0% +interests also end up making him a +metaphysician a philosopher an artist + + align:start position:0% +metaphysician a philosopher an artist + + + align:start position:0% +metaphysician a philosopher an artist +now Keaton himself could never + + align:start position:0% +now Keaton himself could never + + + align:start position:0% +now Keaton himself could never +articulate his own Ambitions in this way + + align:start position:0% +articulate his own Ambitions in this way + + + align:start position:0% +articulate his own Ambitions in this way +if you said Mr Keaton your vision of the + + align:start position:0% +if you said Mr Keaton your vision of the + + + align:start position:0% +if you said Mr Keaton your vision of the +Absurd universe is more complex and Rich + + align:start position:0% +Absurd universe is more complex and Rich + + + align:start position:0% +Absurd universe is more complex and Rich +than Jean Paul Sarge as in fact it is + + align:start position:0% +than Jean Paul Sarge as in fact it is + + + align:start position:0% +than Jean Paul Sarge as in fact it is +incidentally he would laugh he wouldn't + + align:start position:0% +incidentally he would laugh he wouldn't + + + align:start position:0% +incidentally he would laugh he wouldn't +even understand what you were talking + + align:start position:0% +even understand what you were talking + + + align:start position:0% +even understand what you were talking +about not only because he'd never read + + align:start position:0% +about not only because he'd never read + + + align:start position:0% +about not only because he'd never read +sart since he died before he would well + + align:start position:0% +sart since he died before he would well + + + align:start position:0% +sart since he died before he would well +s he was alive when s was alive actually + + align:start position:0% +s he was alive when s was alive actually + + + align:start position:0% +s he was alive when s was alive actually +but but he undoubtedly he did not re but + + align:start position:0% +but but he undoubtedly he did not re but + + + align:start position:0% +but but he undoubtedly he did not re but +the universe that he projects uh has has + + align:start position:0% +the universe that he projects uh has has + + + align:start position:0% +the universe that he projects uh has has +a kind of content or a meaning that's a + + align:start position:0% +a kind of content or a meaning that's a + + + align:start position:0% +a kind of content or a meaning that's a +function of how intelligent he is about + + align:start position:0% +function of how intelligent he is about + + + align:start position:0% +function of how intelligent he is about +exploiting his medium and telling his + + align:start position:0% +exploiting his medium and telling his + + + align:start position:0% +exploiting his medium and telling his +stories as if his jokes Express a vision + + align:start position:0% +stories as if his jokes Express a vision + + + align:start position:0% +stories as if his jokes Express a vision +of Life a sense of experience now this + + align:start position:0% +of Life a sense of experience now this + + + align:start position:0% +of Life a sense of experience now this +so you um and of course this is what + + align:start position:0% +so you um and of course this is what + + + align:start position:0% +so you um and of course this is what +you're looking at is sort of minor + + align:start position:0% +you're looking at is sort of minor + + + align:start position:0% +you're looking at is sort of minor +Keaton here but it but it shows his it + + align:start position:0% +Keaton here but it but it shows his it + + + align:start position:0% +Keaton here but it but it shows his it +shows his technical his technical + + align:start position:0% +shows his technical his technical + + + align:start position:0% +shows his technical his technical +interests well so what I mean so let me + + align:start position:0% +interests well so what I mean so let me + + + align:start position:0% +interests well so what I mean so let me +explain what I mean basically by the + + align:start position:0% +explain what I mean basically by the + + + align:start position:0% +explain what I mean basically by the +multiplicity principle this process of + + align:start position:0% +multiplicity principle this process of + + + align:start position:0% +multiplicity principle this process of +accretion and complexity I've described + + align:start position:0% +accretion and complexity I've described + + + align:start position:0% +accretion and complexity I've described +at a certain point you get to a + + align:start position:0% +at a certain point you get to a + + + align:start position:0% +at a certain point you get to a +situation you get to a point okay look + + align:start position:0% +situation you get to a point okay look + + + align:start position:0% +situation you get to a point okay look +I'm let's shut it off great because I + + align:start position:0% +I'm let's shut it off great because I + + + align:start position:0% +I'm let's shut it off great because I +can see it's just people are paying too + + align:start position:0% +can see it's just people are paying too + + + align:start position:0% +can see it's just people are paying too +much attention to this great artist and + + align:start position:0% +much attention to this great artist and + + + align:start position:0% +much attention to this great artist and +not to me and I want to end it U at a + + align:start position:0% +not to me and I want to end it U at a + + + align:start position:0% +not to me and I want to end it U at a +certain point you get to point where + + align:start position:0% +certain point you get to point where + + + align:start position:0% +certain point you get to point where +what what began as a gag or as a mere + + align:start position:0% +what what began as a gag or as a mere + + + align:start position:0% +what what began as a gag or as a mere +entertainment takes on a density or a + + align:start position:0% +entertainment takes on a density or a + + + align:start position:0% +entertainment takes on a density or a +texture that makes you think wait a + + align:start position:0% +texture that makes you think wait a + + + align:start position:0% +texture that makes you think wait a +second the vision of experience that's + + align:start position:0% +second the vision of experience that's + + + align:start position:0% +second the vision of experience that's +projected in this text is intrinsically + + align:start position:0% +projected in this text is intrinsically + + + align:start position:0% +projected in this text is intrinsically +interesting that is to say there's an + + align:start position:0% +interesting that is to say there's an + + + align:start position:0% +interesting that is to say there's an +understanding of life that's embedded in + + align:start position:0% +understanding of life that's embedded in + + + align:start position:0% +understanding of life that's embedded in +the story when you reach the point where + + align:start position:0% +the story when you reach the point where + + + align:start position:0% +the story when you reach the point where +the text itself embodies some sort of + + align:start position:0% +the text itself embodies some sort of + + + align:start position:0% +the text itself embodies some sort of +understanding of life and it's coherent + + align:start position:0% +understanding of life and it's coherent + + + align:start position:0% +understanding of life and it's coherent +an understanding of life that's + + align:start position:0% +an understanding of life that's + + + align:start position:0% +an understanding of life that's +coherently presented powerfully + + align:start position:0% +coherently presented powerfully + + + align:start position:0% +coherently presented powerfully +presented what you're what you're + + align:start position:0% +presented what you're what you're + + + align:start position:0% +presented what you're what you're +looking at is what I call Art there you + + align:start position:0% +looking at is what I call Art there you + + + align:start position:0% +looking at is what I call Art there you +might just call it more intelligent + + align:start position:0% +might just call it more intelligent + + + align:start position:0% +might just call it more intelligent +entertainment but this is a way of + + align:start position:0% +entertainment but this is a way of + + + align:start position:0% +entertainment but this is a way of +distinguishing between entertainment and + + align:start position:0% +distinguishing between entertainment and + + + align:start position:0% +distinguishing between entertainment and +art in other words there's a certain + + align:start position:0% +art in other words there's a certain + + + align:start position:0% +art in other words there's a certain +point at which entertainment becomes so + + align:start position:0% +point at which entertainment becomes so + + + align:start position:0% +point at which entertainment becomes so +complicated that it's more than mere + + align:start position:0% +complicated that it's more than mere + + + align:start position:0% +complicated that it's more than mere +entertainment when does that occur well + + align:start position:0% +entertainment when does that occur well + + + align:start position:0% +entertainment when does that occur well +one way to tell when it occurs is to + + align:start position:0% +one way to tell when it occurs is to + + + align:start position:0% +one way to tell when it occurs is to +watch for what I call the multiplicity + + align:start position:0% +watch for what I call the multiplicity + + + align:start position:0% +watch for what I call the multiplicity +principle when events in the film play + + align:start position:0% +principle when events in the film play + + + align:start position:0% +principle when events in the film play +more than one function do more than one + + align:start position:0% +more than one function do more than one + + + align:start position:0% +more than one function do more than one +job when they forward the story but also + + align:start position:0% +job when they forward the story but also + + + align:start position:0% +job when they forward the story but also +declare for character when they express + + align:start position:0% +declare for character when they express + + + align:start position:0% +declare for character when they express +when they make you laugh but also + + align:start position:0% +when they make you laugh but also + + + align:start position:0% +when they make you laugh but also +Express a vision of life and at the same + + align:start position:0% +Express a vision of life and at the same + + + align:start position:0% +Express a vision of life and at the same +time ex uh are consistent with the + + align:start position:0% +time ex uh are consistent with the + + + align:start position:0% +time ex uh are consistent with the +character psychological nature that + + align:start position:0% +character psychological nature that + + + align:start position:0% +character psychological nature that +multiplicity that density that texture + + align:start position:0% +multiplicity that density that texture + + + align:start position:0% +multiplicity that density that texture +is what we associate with works of art + + align:start position:0% +is what we associate with works of art + + + align:start position:0% +is what we associate with works of art +right uh a a bad example would be you're + + align:start position:0% +right uh a a bad example would be you're + + + align:start position:0% +right uh a a bad example would be you're +all familiar I hope with the kind of bad + + align:start position:0% +all familiar I hope with the kind of bad + + + align:start position:0% +all familiar I hope with the kind of bad +soap opera line in which a character + + align:start position:0% +soap opera line in which a character + + + align:start position:0% +soap opera line in which a character +comes in and says something like this oh + + align:start position:0% +comes in and says something like this oh + + + align:start position:0% +comes in and says something like this oh +hello John my long lost brother who just + + align:start position:0% +hello John my long lost brother who just + + + align:start position:0% +hello John my long lost brother who just +got out of the insane asylum after 15 + + align:start position:0% +got out of the insane asylum after 15 + + + align:start position:0% +got out of the insane asylum after 15 +years of unfair misery right what's + + align:start position:0% +years of unfair misery right what's + + + align:start position:0% +years of unfair misery right what's +wrong with that line why is that a + + align:start position:0% +wrong with that line why is that a + + + align:start position:0% +wrong with that line why is that a +stupid line although we hear them all + + align:start position:0% +stupid line although we hear them all + + + align:start position:0% +stupid line although we hear them all +the time what what's wrong with it exed + + align:start position:0% +the time what what's wrong with it exed + + + align:start position:0% +the time what what's wrong with it exed +an awkward Exposition it's it's very + + align:start position:0% +an awkward Exposition it's it's very + + + align:start position:0% +an awkward Exposition it's it's very +awkward Exposition but why is it so + + align:start position:0% +awkward Exposition but why is it so + + + align:start position:0% +awkward Exposition but why is it so +awkward what makes it so awkward it's + + align:start position:0% +awkward what makes it so awkward it's + + + align:start position:0% +awkward what makes it so awkward it's +it's its intention is clear it wants to + + align:start position:0% +it's its intention is clear it wants to + + + align:start position:0% +it's its intention is clear it wants to +present information to the audience but + + align:start position:0% +present information to the audience but + + + align:start position:0% +present information to the audience but +in order to do that what what is it + + align:start position:0% +in order to do that what what is it + + + align:start position:0% +in order to do that what what is it +violated um it ceases to be something + + align:start position:0% +violated um it ceases to be something + + + align:start position:0% +violated um it ceases to be something +that follows the nature of the character + + align:start position:0% +that follows the nature of the character + + + align:start position:0% +that follows the nature of the character +it ceases to be something that is that + + align:start position:0% +it ceases to be something that is that + + + align:start position:0% +it ceases to be something that is that +honors the character's nature exactly + + align:start position:0% +honors the character's nature exactly + + + align:start position:0% +honors the character's nature exactly +right that's a very good answer what's + + align:start position:0% +right that's a very good answer what's + + + align:start position:0% +right that's a very good answer what's +your name Michael Michael thank Michael + + align:start position:0% +your name Michael Michael thank Michael + + + align:start position:0% +your name Michael Michael thank Michael +that's very good and what what happened + + align:start position:0% +that's very good and what what happened + + + align:start position:0% +that's very good and what what happened +okay I want to give information to the + + align:start position:0% +okay I want to give information to the + + + align:start position:0% +okay I want to give information to the +audience in order to do that I'll + + align:start position:0% +audience in order to do that I'll + + + align:start position:0% +audience in order to do that I'll +compromise the character's basic nature + + align:start position:0% +compromise the character's basic nature + + + align:start position:0% +compromise the character's basic nature +because no brother to no sister talking + + align:start position:0% +because no brother to no sister talking + + + align:start position:0% +because no brother to no sister talking +to a brother would recount the brother's + + align:start position:0% +to a brother would recount the brother's + + + align:start position:0% +to a brother would recount the brother's +history to the brother right that just + + align:start position:0% +history to the brother right that just + + + align:start position:0% +history to the brother right that just +wouldn't happen right so in order to + + align:start position:0% +wouldn't happen right so in order to + + + align:start position:0% +wouldn't happen right so in order to +accomplish one task the text has + + align:start position:0% +accomplish one task the text has + + + align:start position:0% +accomplish one task the text has +compromised itself on another test but + + align:start position:0% +compromised itself on another test but + + + align:start position:0% +compromised itself on another test but +imagine a story in which this + + align:start position:0% +imagine a story in which this + + + align:start position:0% +imagine a story in which this +information emerges in D in dramatic + + align:start position:0% +information emerges in D in dramatic + + + align:start position:0% +information emerges in D in dramatic +ways two characters are talking and Mary + + align:start position:0% +ways two characters are talking and Mary + + + align:start position:0% +ways two characters are talking and Mary +says to Joan oh Joan my brother's coming + + align:start position:0% +says to Joan oh Joan my brother's coming + + + align:start position:0% +says to Joan oh Joan my brother's coming +back from the Asylum and she says really + + align:start position:0% +back from the Asylum and she says really + + + align:start position:0% +back from the Asylum and she says really +I didn't even know he was in in the + + align:start position:0% +I didn't even know he was in in the + + + align:start position:0% +I didn't even know he was in in the +Asylum and Mary pulls back and says I + + align:start position:0% +Asylum and Mary pulls back and says I + + + align:start position:0% +Asylum and Mary pulls back and says I +don't know if I should tell you okay so + + align:start position:0% +don't know if I should tell you okay so + + + align:start position:0% +don't know if I should tell you okay so +we have a we have a dramatic scene in + + align:start position:0% +we have a we have a dramatic scene in + + + align:start position:0% +we have a we have a dramatic scene in +which what in which the information that + + align:start position:0% +which what in which the information that + + + align:start position:0% +which what in which the information that +the audience is supposed to have is + + align:start position:0% +the audience is supposed to have is + + + align:start position:0% +the audience is supposed to have is +presented in a way that maybe tells us + + align:start position:0% +presented in a way that maybe tells us + + + align:start position:0% +presented in a way that maybe tells us +something about Mary's nature and maybe + + align:start position:0% +something about Mary's nature and maybe + + + align:start position:0% +something about Mary's nature and maybe +tells us something about Joan's nature + + align:start position:0% +tells us something about Joan's nature + + + align:start position:0% +tells us something about Joan's nature +that is multiplicity right more that's + + align:start position:0% +that is multiplicity right more that's + + + align:start position:0% +that is multiplicity right more that's +what I mean by the multiplicity + + align:start position:0% +what I mean by the multiplicity + + + align:start position:0% +what I mean by the multiplicity +principle you will see many many + + align:start position:0% +principle you will see many many + + + align:start position:0% +principle you will see many many +instances of what of what I'm calling + + align:start position:0% +instances of what of what I'm calling + + + align:start position:0% +instances of what of what I'm calling +the multiplicity principle in Keaton's + + align:start position:0% +the multiplicity principle in Keaton's + + + align:start position:0% +the multiplicity principle in Keaton's +work and you will especially see it in + + align:start position:0% +work and you will especially see it in + + + align:start position:0% +work and you will especially see it in +these astonishing repeat + + align:start position:0% +these astonishing repeat + + + align:start position:0% +these astonishing repeat +um uh uh sequences in which we + + align:start position:0% +um uh uh sequences in which we + + + align:start position:0% +um uh uh sequences in which we +see in which we see the and I'm talking + + align:start position:0% +see in which we see the and I'm talking + + + align:start position:0% +see in which we see the and I'm talking +now in a way about the General in which + + align:start position:0% +now in a way about the General in which + + + align:start position:0% +now in a way about the General in which +we see the Keaton hero who sort of uh is + + align:start position:0% +we see the Keaton hero who sort of uh is + + + align:start position:0% +we see the Keaton hero who sort of uh is +steadfast but also a muddler he keeps he + + align:start position:0% +steadfast but also a muddler he keeps he + + + align:start position:0% +steadfast but also a muddler he keeps he +keeps doing the same things they're not + + align:start position:0% +keeps doing the same things they're not + + + align:start position:0% +keeps doing the same things they're not +really likely to help him and then he + + align:start position:0% +really likely to help him and then he + + + align:start position:0% +really likely to help him and then he +gets help from the outside and was what + + align:start position:0% +gets help from the outside and was what + + + align:start position:0% +gets help from the outside and was what +the what Keaton's jokes repeatedly + + align:start position:0% +the what Keaton's jokes repeatedly + + + align:start position:0% +the what Keaton's jokes repeatedly +depend upon the idea of of uh accident + + align:start position:0% +depend upon the idea of of uh accident + + + align:start position:0% +depend upon the idea of of uh accident +in a certain way and I I'll come back to + + align:start position:0% +in a certain way and I I'll come back to + + + align:start position:0% +in a certain way and I I'll come back to +that + + align:start position:0% +that + + + align:start position:0% +that +finally in a second so so think about + + align:start position:0% +finally in a second so so think about + + + align:start position:0% +finally in a second so so think about +the multiplicity principle the + + align:start position:0% +the multiplicity principle the + + + align:start position:0% +the multiplicity principle the +difference between entertainment and art + + align:start position:0% +difference between entertainment and art + + + align:start position:0% +difference between entertainment and art +again this is a principle I'll come back + + align:start position:0% +again this is a principle I'll come back + + + align:start position:0% +again this is a principle I'll come back +to and try to illustrate with greater uh + + align:start position:0% +to and try to illustrate with greater uh + + + align:start position:0% +to and try to illustrate with greater uh +uh concreteness and greater leisure in + + align:start position:0% +uh concreteness and greater leisure in + + + align:start position:0% +uh concreteness and greater leisure in +later lectures but I want you to be + + align:start position:0% +later lectures but I want you to be + + + align:start position:0% +later lectures but I want you to be +aware of these of these issues so the + + align:start position:0% +aware of these of these issues so the + + + align:start position:0% +aware of these of these issues so the +general made in 1927 can be seen as a + + align:start position:0% +general made in 1927 can be seen as a + + + align:start position:0% +general made in 1927 can be seen as a +kind of culminating text I'm sorry I'm + + align:start position:0% +kind of culminating text I'm sorry I'm + + + align:start position:0% +kind of culminating text I'm sorry I'm +running over again I won't do it after + + align:start position:0% +running over again I won't do it after + + + align:start position:0% +running over again I won't do it after +today but what I've what I've tried to + + align:start position:0% +today but what I've what I've tried to + + + align:start position:0% +today but what I've what I've tried to +do you please forgive me about this but + + align:start position:0% +do you please forgive me about this but + + + align:start position:0% +do you please forgive me about this but +I I'm very respectful of the fact that + + align:start position:0% +I I'm very respectful of the fact that + + + align:start position:0% +I I'm very respectful of the fact that +you guys guys have schedules so I + + align:start position:0% +you guys guys have schedules so I + + + align:start position:0% +you guys guys have schedules so I +normally would not will not run over but + + align:start position:0% +normally would not will not run over but + + + align:start position:0% +normally would not will not run over but +I'm I I've condensed into into only two + + align:start position:0% +I'm I I've condensed into into only two + + + align:start position:0% +I'm I I've condensed into into only two +lectures what I normally do in four + + align:start position:0% +lectures what I normally do in four + + + align:start position:0% +lectures what I normally do in four +that's why I'm a little oppressed and + + align:start position:0% +that's why I'm a little oppressed and + + + align:start position:0% +that's why I'm a little oppressed and +not quite saying as much as I had hoped + + align:start position:0% +not quite saying as much as I had hoped + + + align:start position:0% +not quite saying as much as I had hoped +to say here um so the general can be + + align:start position:0% +to say here um so the general can be + + + align:start position:0% +to say here um so the general can be +understood as a kind of culminating text + + align:start position:0% +understood as a kind of culminating text + + + align:start position:0% +understood as a kind of culminating text +in at least two ways it's a culmination + + align:start position:0% +in at least two ways it's a culmination + + + align:start position:0% +in at least two ways it's a culmination +of Keaton's career that is to say the + + align:start position:0% +of Keaton's career that is to say the + + + align:start position:0% +of Keaton's career that is to say the +jokes and gags that are enacted in in uh + + align:start position:0% +jokes and gags that are enacted in in uh + + + align:start position:0% +jokes and gags that are enacted in in uh +in the film recall many earlier Katon + + align:start position:0% +in the film recall many earlier Katon + + + align:start position:0% +in the film recall many earlier Katon +films and the basic character of the + + align:start position:0% +films and the basic character of the + + + align:start position:0% +films and the basic character of the +general is the basic character of the + + align:start position:0% +general is the basic character of the + + + align:start position:0% +general is the basic character of the +Katon hero a steadfast unremarkable + + align:start position:0% +Katon hero a steadfast unremarkable + + + align:start position:0% +Katon hero a steadfast unremarkable +young man who perseveres in the face of + + align:start position:0% +young man who perseveres in the face of + + + align:start position:0% +young man who perseveres in the face of +catastrophic difficulties with mostly + + align:start position:0% +catastrophic difficulties with mostly + + + align:start position:0% +catastrophic difficulties with mostly +comic expectations very small + + align:start position:0% +comic expectations very small + + + align:start position:0% +comic expectations very small +expectations of success who often + + align:start position:0% +expectations of success who often + + + align:start position:0% +expectations of success who often +muddles through almost despite himself + + align:start position:0% +muddles through almost despite himself + + + align:start position:0% +muddles through almost despite himself +right now but it isn't merely but I say + + align:start position:0% +right now but it isn't merely but I say + + + align:start position:0% +right now but it isn't merely but I say +almost despite himself and this is where + + align:start position:0% +almost despite himself and this is where + + + align:start position:0% +almost despite himself and this is where +the complexity of Keaton's vision of + + align:start position:0% +the complexity of Keaton's vision of + + + align:start position:0% +the complexity of Keaton's vision of +Life comes in why I'm saying that Keaton + + align:start position:0% +Life comes in why I'm saying that Keaton + + + align:start position:0% +Life comes in why I'm saying that Keaton +moves from being merely a jokester or + + align:start position:0% +moves from being merely a jokester or + + + align:start position:0% +moves from being merely a jokester or +being merely a great Entertainer to + + align:start position:0% +being merely a great Entertainer to + + + align:start position:0% +being merely a great Entertainer to +being an artist his jokes embody an idea + + align:start position:0% +being an artist his jokes embody an idea + + + align:start position:0% +being an artist his jokes embody an idea +of what experience is like and it's a + + align:start position:0% +of what experience is like and it's a + + + align:start position:0% +of what experience is like and it's a +very powerful Morant mature idea of + + align:start position:0% +very powerful Morant mature idea of + + + align:start position:0% +very powerful Morant mature idea of +experience because what happens again + + align:start position:0% +experience because what happens again + + + align:start position:0% +experience because what happens again +and again in the small jokes the sequenc + + align:start position:0% +and again in the small jokes the sequenc + + + align:start position:0% +and again in the small jokes the sequenc +jokes in Keaton's work especially in the + + align:start position:0% +jokes in Keaton's work especially in the + + + align:start position:0% +jokes in Keaton's work especially in the +general and in the larger film what + + align:start position:0% +general and in the larger film what + + + align:start position:0% +general and in the larger film what +happens again and again is a is a a an + + align:start position:0% +happens again and again is a is a a an + + + align:start position:0% +happens again and again is a is a a an +adventure in which a steadfast + + align:start position:0% +adventure in which a steadfast + + + align:start position:0% +adventure in which a steadfast +Relentless young hero does everything he + + align:start position:0% +Relentless young hero does everything he + + + align:start position:0% +Relentless young hero does everything he +can to to uh accomplish his goal and + + align:start position:0% +can to to uh accomplish his goal and + + + align:start position:0% +can to to uh accomplish his goal and +it's obvious that he's up against forces + + align:start position:0% +it's obvious that he's up against forces + + + align:start position:0% +it's obvious that he's up against forces +far beyond himself that he could never + + align:start position:0% +far beyond himself that he could never + + + align:start position:0% +far beyond himself that he could never +that there's a unbelievable Mis mismatch + + align:start position:0% +that there's a unbelievable Mis mismatch + + + align:start position:0% +that there's a unbelievable Mis mismatch +between this minuscule tiny figure and + + align:start position:0% +between this minuscule tiny figure and + + + align:start position:0% +between this minuscule tiny figure and +the and his powers and the forces he's + + align:start position:0% +the and his powers and the forces he's + + + align:start position:0% +the and his powers and the forces he's +he's fighting against there's one Katon + + align:start position:0% +he's fighting against there's one Katon + + + align:start position:0% +he's fighting against there's one Katon +film called The Navigator in which the + + align:start position:0% +film called The Navigator in which the + + + align:start position:0% +film called The Navigator in which the +Katon character even more than with the + + align:start position:0% +Katon character even more than with the + + + align:start position:0% +Katon character even more than with the +locomotive in the general has to + + align:start position:0% +locomotive in the general has to + + + align:start position:0% +locomotive in the general has to +navigate an ocean liner and he's alone + + align:start position:0% +navigate an ocean liner and he's alone + + + align:start position:0% +navigate an ocean liner and he's alone +on the ocean liner and you see him + + align:start position:0% +on the ocean liner and you see him + + + align:start position:0% +on the ocean liner and you see him +running up and down into the engine room + + align:start position:0% +running up and down into the engine room + + + align:start position:0% +running up and down into the engine room +back up to the up to the bridge that + + align:start position:0% +back up to the up to the bridge that + + + align:start position:0% +back up to the up to the bridge that +running all over the ocean liner in a in + + align:start position:0% +running all over the ocean liner in a in + + + align:start position:0% +running all over the ocean liner in a in +in in great difficulties there's a + + align:start position:0% +in in great difficulties there's a + + + align:start position:0% +in in great difficulties there's a +Wonder Beau film late film made in 1928 + + align:start position:0% +Wonder Beau film late film made in 1928 + + + align:start position:0% +Wonder Beau film late film made in 1928 +just his last silent film called + + align:start position:0% +just his last silent film called + + + align:start position:0% +just his last silent film called +Steamboat Bill Jr in which he dramatizes + + align:start position:0% +Steamboat Bill Jr in which he dramatizes + + + align:start position:0% +Steamboat Bill Jr in which he dramatizes +an astonishing song an astonishing an + + align:start position:0% +an astonishing song an astonishing an + + + align:start position:0% +an astonishing song an astonishing an +astonishing um uh hurricane uh a long + + align:start position:0% +astonishing um uh hurricane uh a long + + + align:start position:0% +astonishing um uh hurricane uh a long +extended sequence in which we see him + + align:start position:0% +extended sequence in which we see him + + + align:start position:0% +extended sequence in which we see him +trying to escape the hurricane uh trying + + align:start position:0% +trying to escape the hurricane uh trying + + + align:start position:0% +trying to escape the hurricane uh trying +to contend against this natural force + + align:start position:0% +to contend against this natural force + + + align:start position:0% +to contend against this natural force +that's so gigantic so the the so so the + + align:start position:0% +that's so gigantic so the the so so the + + + align:start position:0% +that's so gigantic so the the so so the +the general is a culmination in the + + align:start position:0% +the general is a culmination in the + + + align:start position:0% +the general is a culmination in the +sense that it gives us another version + + align:start position:0% +sense that it gives us another version + + + align:start position:0% +sense that it gives us another version +and the richest the richest version so + + align:start position:0% +and the richest the richest version so + + + align:start position:0% +and the richest the richest version so +far of the of The Adventures of this + + align:start position:0% +far of the of The Adventures of this + + + align:start position:0% +far of the of The Adventures of this +kind of Katon hero but what makes it a + + align:start position:0% +kind of Katon hero but what makes it a + + + align:start position:0% +kind of Katon hero but what makes it a +what makes it sort of metaphysical or + + align:start position:0% +what makes it sort of metaphysical or + + + align:start position:0% +what makes it sort of metaphysical or +philosophically interesting is that what + + align:start position:0% +philosophically interesting is that what + + + align:start position:0% +philosophically interesting is that what +what this joke repeatedly does and what + + align:start position:0% +what this joke repeatedly does and what + + + align:start position:0% +what this joke repeatedly does and what +the structure of the whole film + + align:start position:0% +the structure of the whole film + + + align:start position:0% +the structure of the whole film +repeatedly says is something like this + + align:start position:0% +repeatedly says is something like this + + + align:start position:0% +repeatedly says is something like this +we get through we make it through life + + align:start position:0% +we get through we make it through life + + + align:start position:0% +we get through we make it through life +not Mo mostly it's a it's a great comic + + align:start position:0% +not Mo mostly it's a it's a great comic + + + align:start position:0% +not Mo mostly it's a it's a great comic +more comic video we get through life + + align:start position:0% +more comic video we get through life + + + align:start position:0% +more comic video we get through life +mostly not because of anything we've + + align:start position:0% +mostly not because of anything we've + + + align:start position:0% +mostly not because of anything we've +done but because of accident we live in + + align:start position:0% +done but because of accident we live in + + + align:start position:0% +done but because of accident we live in +a contingent Universe right the idea of + + align:start position:0% +a contingent Universe right the idea of + + + align:start position:0% +a contingent Universe right the idea of +contingency is at the heart part of what + + align:start position:0% +contingency is at the heart part of what + + + align:start position:0% +contingency is at the heart part of what +of of of Keaton's jokes we could we + + align:start position:0% +of of of Keaton's jokes we could we + + + align:start position:0% +of of of Keaton's jokes we could we +could call them jokes about contingency + + align:start position:0% +could call them jokes about contingency + + + align:start position:0% +could call them jokes about contingency +the word contingent is interesting + + align:start position:0% +the word contingent is interesting + + + align:start position:0% +the word contingent is interesting +remember it means both Li it means + + align:start position:0% +remember it means both Li it means + + + align:start position:0% +remember it means both Li it means +liable but not certain but not certain + + align:start position:0% +liable but not certain but not certain + + + align:start position:0% +liable but not certain but not certain +to occur it means possible right so so + + align:start position:0% +to occur it means possible right so so + + + align:start position:0% +to occur it means possible right so so +uh for it's means dependent upon subject + + align:start position:0% +uh for it's means dependent upon subject + + + align:start position:0% +uh for it's means dependent upon subject +to conditioned by right in law you can + + align:start position:0% +to conditioned by right in law you can + + + align:start position:0% +to conditioned by right in law you can +say something uh you can say that + + align:start position:0% +say something uh you can say that + + + align:start position:0% +say something uh you can say that +something that is contingent is + + align:start position:0% +something that is contingent is + + + align:start position:0% +something that is contingent is +dependent for its effect on something + + align:start position:0% +dependent for its effect on something + + + align:start position:0% +dependent for its effect on something +that may or may not occur as in a + + align:start position:0% +that may or may not occur as in a + + + align:start position:0% +that may or may not occur as in a +contingent estate or Legacy right in + + align:start position:0% +contingent estate or Legacy right in + + + align:start position:0% +contingent estate or Legacy right in +Logic the same thing dependent upon some + + align:start position:0% +Logic the same thing dependent upon some + + + align:start position:0% +Logic the same thing dependent upon some +condition or upon the truth of something + + align:start position:0% +condition or upon the truth of something + + + align:start position:0% +condition or upon the truth of something +else not true a priori not necessary so + + align:start position:0% +else not true a priori not necessary so + + + align:start position:0% +else not true a priori not necessary so +what Keaton's jokes constantly do is + + align:start position:0% +what Keaton's jokes constantly do is + + + align:start position:0% +what Keaton's jokes constantly do is +they show us two things they show us a + + align:start position:0% +they show us two things they show us a + + + align:start position:0% +they show us two things they show us a +world in which human agency matters + + align:start position:0% +world in which human agency matters + + + align:start position:0% +world in which human agency matters +because if this schmendrick didn't keep + + align:start position:0% +because if this schmendrick didn't keep + + + align:start position:0% +because if this schmendrick didn't keep +that's a Jewish word for + + align:start position:0% +that's a Jewish word for + + + align:start position:0% +that's a Jewish word for +schlamazel it's a clown if this + + align:start position:0% +schlamazel it's a clown if this + + + align:start position:0% +schlamazel it's a clown if this +schmendrick did not if this schmendrick + + align:start position:0% +schmendrick did not if this schmendrick + + + align:start position:0% +schmendrick did not if this schmendrick +did not um keep on so Stead fastly he + + align:start position:0% +did not um keep on so Stead fastly he + + + align:start position:0% +did not um keep on so Stead fastly he +wouldn't survive but his keeping on so + + align:start position:0% +wouldn't survive but his keeping on so + + + align:start position:0% +wouldn't survive but his keeping on so +steadfastly still wouldn't make him + + align:start position:0% +steadfastly still wouldn't make him + + + align:start position:0% +steadfastly still wouldn't make him +survive if there weren't the + + align:start position:0% +survive if there weren't the + + + align:start position:0% +survive if there weren't the +intervention of mere accidents stuff he + + align:start position:0% +intervention of mere accidents stuff he + + + align:start position:0% +intervention of mere accidents stuff he +has no control over there's one + + align:start position:0% +has no control over there's one + + + align:start position:0% +has no control over there's one +magnificent moment in the in in one week + + align:start position:0% +magnificent moment in the in in one week + + + align:start position:0% +magnificent moment in the in in one week +for example where I think it's one week + + align:start position:0% +for example where I think it's one week + + + align:start position:0% +for example where I think it's one week +where he's standing in a certain place + + align:start position:0% +where he's standing in a certain place + + + align:start position:0% +where he's standing in a certain place +and the house and the house behind him + + align:start position:0% +and the house and the house behind him + + + align:start position:0% +and the house and the house behind him +falls down and he happens just by + + align:start position:0% +falls down and he happens just by + + + align:start position:0% +falls down and he happens just by +accident to be standing so that by the + + align:start position:0% +accident to be standing so that by the + + + align:start position:0% +accident to be standing so that by the +open window the house Falls so he + + align:start position:0% +open window the house Falls so he + + + align:start position:0% +open window the house Falls so he +doesn't get hurt he used this joke more + + align:start position:0% +doesn't get hurt he used this joke more + + + align:start position:0% +doesn't get hurt he used this joke more +than once in other films because such a + + align:start position:0% +than once in other films because such a + + + align:start position:0% +than once in other films because such a +great one but it's a perfect example of + + align:start position:0% +great one but it's a perfect example of + + + align:start position:0% +great one but it's a perfect example of +what I mean + + align:start position:0% +what I mean + + + align:start position:0% +what I mean +a partial example of what I mean because + + align:start position:0% +a partial example of what I mean because + + + align:start position:0% +a partial example of what I mean because +he's not responsible for the fact that + + align:start position:0% +he's not responsible for the fact that + + + align:start position:0% +he's not responsible for the fact that +he escaped on the other hand because he + + align:start position:0% +he escaped on the other hand because he + + + align:start position:0% +he escaped on the other hand because he +was trying to get away from difficulties + + align:start position:0% +was trying to get away from difficulties + + + align:start position:0% +was trying to get away from difficulties +maybe he was in that particular position + + align:start position:0% +maybe he was in that particular position + + + align:start position:0% +maybe he was in that particular position +because of Acts of his own so so what it + + align:start position:0% +because of Acts of his own so so what it + + + align:start position:0% +because of Acts of his own so so what it +says what what so what this joking + + align:start position:0% +says what what so what this joking + + + align:start position:0% +says what what so what this joking +Vision says about the world is something + + align:start position:0% +Vision says about the world is something + + + align:start position:0% +Vision says about the world is something +that's true we all love the idea that + + align:start position:0% +that's true we all love the idea that + + + align:start position:0% +that's true we all love the idea that +we've gotten to where we are by our own + + align:start position:0% +we've gotten to where we are by our own + + + align:start position:0% +we've gotten to where we are by our own +acts by our own conscious control the + + align:start position:0% +acts by our own conscious control the + + + align:start position:0% +acts by our own conscious control the +truth of the matter is that life that + + align:start position:0% +truth of the matter is that life that + + + align:start position:0% +truth of the matter is that life that +life is much more contingent than that + + align:start position:0% +life is much more contingent than that + + + align:start position:0% +life is much more contingent than that +it's partly accident it's partly luck + + align:start position:0% +it's partly accident it's partly luck + + + align:start position:0% +it's partly accident it's partly luck +and something deeper than that + + align:start position:0% +and something deeper than that + + + align:start position:0% +and something deeper than that +Keaton's vision of the universe is one + + align:start position:0% +Keaton's vision of the universe is one + + + align:start position:0% +Keaton's vision of the universe is one +which suggests that while the universe + + align:start position:0% +which suggests that while the universe + + + align:start position:0% +which suggests that while the universe +may screw you up sometimes it won't + + align:start position:0% +may screw you up sometimes it won't + + + align:start position:0% +may screw you up sometimes it won't +always do that that is to say it's not + + align:start position:0% +always do that that is to say it's not + + + align:start position:0% +always do that that is to say it's not +the universe in Keaton's world is not + + align:start position:0% +the universe in Keaton's world is not + + + align:start position:0% +the universe in Keaton's world is not +angry at us it's indifferent to us it + + align:start position:0% +angry at us it's indifferent to us it + + + align:start position:0% +angry at us it's indifferent to us it +doesn't give a damn about us it's not + + align:start position:0% +doesn't give a damn about us it's not + + + align:start position:0% +doesn't give a damn about us it's not +aware of us it's too big for us right + + align:start position:0% +aware of us it's too big for us right + + + align:start position:0% +aware of us it's too big for us right +you can't come away from Keaton's films + + align:start position:0% +you can't come away from Keaton's films + + + align:start position:0% +you can't come away from Keaton's films +without a simultaneous sense of the + + align:start position:0% +without a simultaneous sense of the + + + align:start position:0% +without a simultaneous sense of the +importance of Human Action of human + + align:start position:0% +importance of Human Action of human + + + align:start position:0% +importance of Human Action of human +agency but also of the inadequacy of + + align:start position:0% +agency but also of the inadequacy of + + + align:start position:0% +agency but also of the inadequacy of +human agency of how contingent every + + align:start position:0% +human agency of how contingent every + + + align:start position:0% +human agency of how contingent every +experience every Adventure every + + align:start position:0% +experience every Adventure every + + + align:start position:0% +experience every Adventure every +personality is and that and that meaning + + align:start position:0% +personality is and that and that meaning + + + align:start position:0% +personality is and that and that meaning +that idea of the world is a profound one + + align:start position:0% +that idea of the world is a profound one + + + align:start position:0% +that idea of the world is a profound one +I think it tells so that so that even + + align:start position:0% +I think it tells so that so that even + + + align:start position:0% +I think it tells so that so that even +though Keaton is telling a joke embedded + + align:start position:0% +though Keaton is telling a joke embedded + + + align:start position:0% +though Keaton is telling a joke embedded +in the joke is a kind of interpretation + + align:start position:0% +in the joke is a kind of interpretation + + + align:start position:0% +in the joke is a kind of interpretation +of life and embedded in the film is a + + align:start position:0% +of life and embedded in the film is a + + + align:start position:0% +of life and embedded in the film is a +kind of interpretation of Life uh when + + align:start position:0% +kind of interpretation of Life uh when + + + align:start position:0% +kind of interpretation of Life uh when +you're looking at the general I think + + align:start position:0% +you're looking at the general I think + + + align:start position:0% +you're looking at the general I think +you will see multiple examples of this + + align:start position:0% +you will see multiple examples of this + + + align:start position:0% +you will see multiple examples of this +kind of thing let me say one last thing + + align:start position:0% +kind of thing let me say one last thing + + + align:start position:0% +kind of thing let me say one last thing +I haven't mentioned anything about the + + align:start position:0% +I haven't mentioned anything about the + + + align:start position:0% +I haven't mentioned anything about the +structure of the film I'm a little out + + align:start position:0% +structure of the film I'm a little out + + + align:start position:0% +structure of the film I'm a little out +of of order watch how the film is + + align:start position:0% +of of order watch how the film is + + + align:start position:0% +of of order watch how the film is +structured it it's a it's a much more + + align:start position:0% +structured it it's a it's a much more + + + align:start position:0% +structured it it's a it's a much more +complex variation on what I said about + + align:start position:0% +complex variation on what I said about + + + align:start position:0% +complex variation on what I said about +Londale operator the film begins with + + align:start position:0% +Londale operator the film begins with + + + align:start position:0% +Londale operator the film begins with +him going up the track and then the + + align:start position:0% +him going up the track and then the + + + align:start position:0% +him going up the track and then the +second half of the film has him going + + align:start position:0% +second half of the film has him going + + + align:start position:0% +second half of the film has him going +back down the track you may not be aware + + align:start position:0% +back down the track you may not be aware + + + align:start position:0% +back down the track you may not be aware +of it but actually the film in a certain + + align:start position:0% +of it but actually the film in a certain + + + align:start position:0% +of it but actually the film in a certain +sense has its tail in its mouth when it + + align:start position:0% +sense has its tail in its mouth when it + + + align:start position:0% +sense has its tail in its mouth when it +goes up the track he has a series of + + align:start position:0% +goes up the track he has a series of + + + align:start position:0% +goes up the track he has a series of +Adventures when he comes back down he + + align:start position:0% +Adventures when he comes back down he + + + align:start position:0% +Adventures when he comes back down he +has a series of Adventures that in a + + align:start position:0% +has a series of Adventures that in a + + + align:start position:0% +has a series of Adventures that in a +certain sense replicate what's happened + + align:start position:0% +certain sense replicate what's happened + + + align:start position:0% +certain sense replicate what's happened +before the film mirrors itself in a way + + align:start position:0% +before the film mirrors itself in a way + + + align:start position:0% +before the film mirrors itself in a way +repeats itself what + + align:start position:0% +repeats itself what + + + align:start position:0% +repeats itself what +it's an incredibly elegant structure + + align:start position:0% +it's an incredibly elegant structure + + + align:start position:0% +it's an incredibly elegant structure +it's incred and and the Elegance of the + + align:start position:0% +it's incred and and the Elegance of the + + + align:start position:0% +it's incred and and the Elegance of the +structure reminds us also of the in its + + align:start position:0% +structure reminds us also of the in its + + + align:start position:0% +structure reminds us also of the in its +own way also reminds us of this + + align:start position:0% +own way also reminds us of this + + + align:start position:0% +own way also reminds us of this +principle of contingency that's at the + + align:start position:0% +principle of contingency that's at the + + + align:start position:0% +principle of contingency that's at the +heart of Keaton's vision of the world + + align:start position:0% +heart of Keaton's vision of the world + + + align:start position:0% +heart of Keaton's vision of the world +let me conclude by reminding you again + + align:start position:0% +let me conclude by reminding you again + + + align:start position:0% +let me conclude by reminding you again +of what I said earlier when I call + + align:start position:0% +of what I said earlier when I call + + + align:start position:0% +of what I said earlier when I call +Keaton a philosopher and a metaphysician + + align:start position:0% +Keaton a philosopher and a metaphysician + + + align:start position:0% +Keaton a philosopher and a metaphysician +and a wise person about the world I do + + align:start position:0% +and a wise person about the world I do + + + align:start position:0% +and a wise person about the world I do +not at all mean to suggest that if you + + align:start position:0% +not at all mean to suggest that if you + + + align:start position:0% +not at all mean to suggest that if you +asked Katon to explain how he thought + + align:start position:0% +asked Katon to explain how he thought + + + align:start position:0% +asked Katon to explain how he thought +about the world he could do this that's + + align:start position:0% +about the world he could do this that's + + + align:start position:0% +about the world he could do this that's +that's the job of professors and + + align:start position:0% +that's the job of professors and + + + align:start position:0% +that's the job of professors and +literary and film critics right what I'm + + align:start position:0% +literary and film critics right what I'm + + + align:start position:0% +literary and film critics right what I'm +saying to you is that Keaton like many + + align:start position:0% +saying to you is that Keaton like many + + + align:start position:0% +saying to you is that Keaton like many +great artists had an intuitive + + align:start position:0% +great artists had an intuitive + + + align:start position:0% +great artists had an intuitive +understanding of the world which he + + align:start position:0% +understanding of the world which he + + + align:start position:0% +understanding of the world which he +expressed with greater and greater + + align:start position:0% +expressed with greater and greater + + + align:start position:0% +expressed with greater and greater +complexity in the medium of the cinema + + align:start position:0% +complexity in the medium of the cinema + + + align:start position:0% +complexity in the medium of the cinema +and in the general we have what is + + align:start position:0% +and in the general we have what is + + + align:start position:0% +and in the general we have what is +ultimately a culminating instance of + + align:start position:0% +ultimately a culminating instance of + + + align:start position:0% +ultimately a culminating instance of +that one last point about the film as a + + align:start position:0% +that one last point about the film as a + + + align:start position:0% +that one last point about the film as a +culminating example it's not just a + + align:start position:0% +culminating example it's not just a + + + align:start position:0% +culminating example it's not just a +culmination of Keaton's career it's a + + align:start position:0% +culmination of Keaton's career it's a + + + align:start position:0% +culmination of Keaton's career it's a +culmination of silent film in in it in + + align:start position:0% +culmination of silent film in in it in + + + align:start position:0% +culmination of silent film in in it in +as a whole Katon would have expected his + + align:start position:0% +as a whole Katon would have expected his + + + align:start position:0% +as a whole Katon would have expected his +audience to recognize the degree to + + align:start position:0% +audience to recognize the degree to + + + align:start position:0% +audience to recognize the degree to +which this film was a parody or a + + align:start position:0% +which this film was a parody or a + + + align:start position:0% +which this film was a parody or a +mockery of famous historical films made + + align:start position:0% +mockery of famous historical films made + + + align:start position:0% +mockery of famous historical films made +by DW Griffith it puts down the + + align:start position:0% +by DW Griffith it puts down the + + + align:start position:0% +by DW Griffith it puts down the +pretentiousness and the Marshal Valor + + align:start position:0% +pretentiousness and the Marshal Valor + + + align:start position:0% +pretentiousness and the Marshal Valor +that's celebrated in so many of the + + align:start position:0% +that's celebrated in so many of the + + + align:start position:0% +that's celebrated in so many of the +historical spectacles that Griffith and + + align:start position:0% +historical spectacles that Griffith and + + + align:start position:0% +historical spectacles that Griffith and +other serious directors were making at + + align:start position:0% +other serious directors were making at + + + align:start position:0% +other serious directors were making at +the time uh and it and it also goes back + + align:start position:0% +the time uh and it and it also goes back + + + align:start position:0% +the time uh and it and it also goes back +in a certain way to the very roots of + + align:start position:0% +in a certain way to the very roots of + + + align:start position:0% +in a certain way to the very roots of +film what was the very first narrative + + align:start position:0% +film what was the very first narrative + + + align:start position:0% +film what was the very first narrative +film or one of the very first the the + + align:start position:0% +film or one of the very first the the + + + align:start position:0% +film or one of the very first the the +also a film about a train robbery right + + align:start position:0% +also a film about a train robbery right + + + align:start position:0% +also a film about a train robbery right +called The Great Train Robbery well this + + align:start position:0% +called The Great Train Robbery well this + + + align:start position:0% +called The Great Train Robbery well this +is about a train robbery too and who is + + align:start position:0% +is about a train robbery too and who is + + + align:start position:0% +is about a train robbery too and who is +the central character in this film + + align:start position:0% +the central character in this film + + + align:start position:0% +the central character in this film +really a a train is the central object + + align:start position:0% +really a a train is the central object + + + align:start position:0% +really a a train is the central object +the central more more interesting in + + align:start position:0% +the central more more interesting in + + + align:start position:0% +the central more more interesting in +some ways than the character himself + + align:start position:0% +some ways than the character himself + + + align:start position:0% +some ways than the character himself +there and there are many other ways in + + align:start position:0% +there and there are many other ways in + + + align:start position:0% +there and there are many other ways in +which the particular features of the + + align:start position:0% +which the particular features of the + + + align:start position:0% +which the particular features of the +general allude to and in some sense + + align:start position:0% +general allude to and in some sense + + + align:start position:0% +general allude to and in some sense +summarize the history of silent film and + + align:start position:0% +summarize the history of silent film and + + + align:start position:0% +summarize the history of silent film and +all of the original audience coming to + + align:start position:0% +all of the original audience coming to + + + align:start position:0% +all of the original audience coming to +see the general would have been of + + align:start position:0% +see the general would have been of + + + align:start position:0% +see the general would have been of +course alert to these connections would + + align:start position:0% +course alert to these connections would + + + align:start position:0% +course alert to these connections would +have been literate in these connections + + align:start position:0% +have been literate in these connections + + + align:start position:0% +have been literate in these connections +wouldn't needed footnotes or professors + + align:start position:0% +wouldn't needed footnotes or professors + + + align:start position:0% +wouldn't needed footnotes or professors +to tell them about it because they would + + align:start position:0% +to tell them about it because they would + + + align:start position:0% +to tell them about it because they would +have lived through the history they + + align:start position:0% +have lived through the history they + + + align:start position:0% +have lived through the history they +would have lived through the history of + + align:start position:0% +would have lived through the history of + + + align:start position:0% +would have lived through the history of +the previous 20 years they would have + + align:start position:0% +the previous 20 years they would have + + + align:start position:0% +the previous 20 years they would have +seen other Katon films they would have + + align:start position:0% +seen other Katon films they would have + + + align:start position:0% +seen other Katon films they would have +seen DW Griffith they would have the + + align:start position:0% +seen DW Griffith they would have the + + + align:start position:0% +seen DW Griffith they would have the +history of the of the uh medium of + + align:start position:0% +history of the of the uh medium of + + + align:start position:0% +history of the of the uh medium of +movies in their heads when they sat down + + align:start position:0% +movies in their heads when they sat down + + + align:start position:0% +movies in their heads when they sat down +to watch the general so that's another + + align:start position:0% +to watch the general so that's another + + + align:start position:0% +to watch the general so that's another +way in which the general is a profoundly + + align:start position:0% +way in which the general is a profoundly + + + align:start position:0% +way in which the general is a profoundly +culminating text I'm sorry I ran over I + + align:start position:0% +culminating text I'm sorry I ran over I + + + align:start position:0% +culminating text I'm sorry I ran over I +will not do it hereafter \ No newline at end of file diff --git a/K1dbnQDAG8Q.txt b/K1dbnQDAG8Q.txt new file mode 100644 index 0000000000000000000000000000000000000000..866ac31cfa602288ad629ad344bf83071ad1e728 --- /dev/null +++ b/K1dbnQDAG8Q.txt @@ -0,0 +1,233 @@ +Serial point-to-point links +are the modern replacement + +for the parallel +communications bus + +with all its electrical +and timing issues. + +0..08 Each link is +unidirectional and has only + +a single driver and the receiver +recovers the clock signal from + +the data stream, so there are +no complications from sharing + +the channel, clock skew, +and electrical problems. + +The very controlled electrical +environment enables very high + +signaling rates, well up into +the gigahertz range using + +today’s technologies. + +If more throughput +is needed, you + +can use multiple serial +links in parallel. + +Extra logic is needed to +reassemble the original data + +from multiple packets sent in +parallel over multiple links, + +but the cost of the +required logic gates + +is very modest in +current technologies. + +Note that the expansion +strategy of modern systems + +still uses the notion +of an add-in card that + +plugs into the motherboard. + +But instead of connecting +to a parallel bus, + +the add-in card +connects to one or more + +point-to-point +communication links. + +Here’s the system-level +communications diagram + +for a recent system based on +an Intel Core i7 CPU chip. + +The CPU is connected +directly to the memories + +for the highest-possible +memory bandwidth, + +but talks to all +the other components + +over the QuickPath +Interconnect (QPI), + +which has 20 +differential signaling + +paths in each direction. + +QPI supports up to 6.4 +billion 20-bit transfers + +in each direction every second. + +All the other +communication channels + +(USB, PCIe, networks, +Serial ATA, Audio, etc.) + +are also serial links, +providing various communication + +bandwidths depending +on the application. + +Reading about the QPI +channel used by the CPU + +reminded me a lot +of the one ring + +that could be used +to control all + +of Middle Earth in the Tolkien +trilogy Lord of the Rings. + +Why mess around with a lot +of specialized communication + +channels when you have a single +solution that’s powerful enough + +to solve all your +communication needs? + +PCI Express (PCIe) is often +used as the communication + +link between components +on the system motherboard. + +A single PCIe version 2 “lane” +transmits data at 5 Gb/sec + +using low-voltage differential +signaling (LVDS) over wires + +designed to have a 100-Ohm +characteristic impedance. + +The PCIe lane is +under the control + +of the same sort of network +stack as described earlier. + +The physical layer transmits +packet data through the wire. + +Each packet starts with +a training sequence + +to synchronize the receiver’s +clock-recovery circuitry, + +followed by a unique +start sequence, + +then the packet’s data payload, +and ends with a unique end + +sequence. + +The physical layer payload is +organized as a sequence number, + +a transaction-layer payload +and a cyclical redundancy check + +sequence that’s used +to validate the data. + +Using the sequence number, +the data link layer + +can tell when a packet +has been dropped + +and request the transmitter +restart transmission + +at the missing packet. + +It also deals with +flow control issues. + +Finally, the transaction +layer reassembles the message + +from the transaction layer +payloads from all the lanes + +and uses the header to identify +the intended recipient at the + +receive end. + +Altogether, a significant amount +of logic is needed to send + +and receive messages +on multiple PCIe lanes, + +but the cost is quite acceptable +when using today’s integrated + +circuit technologies. + +Using 8 lanes, the maximum +transfer rate is 4 GB/sec, + +capable of satisfying the needs +of high-performance peripherals + +such as graphics cards. + +So knowledge from +the networking world + +has reshaped how components +communicate on the motherboard, + +driving the transition +from parallel buses + +to a handful of serial +point-to-point links. + +As a result today’s systems +are faster, more reliable, + +more energy-efficient and +smaller than ever before. \ No newline at end of file diff --git a/KKj4FAMF1Bk.txt b/KKj4FAMF1Bk.txt new file mode 100644 index 0000000000000000000000000000000000000000..eb33fc71ff6cc1ce7481ae6112bf023ff4c21331 --- /dev/null +++ b/KKj4FAMF1Bk.txt @@ -0,0 +1,251 @@ +align:start position:0% + +really good really good yeah yeah very + + align:start position:0% +really good really good yeah yeah very + + + align:start position:0% +really good really good yeah yeah very +very excited um I have like three most + + align:start position:0% +very excited um I have like three most + + + align:start position:0% +very excited um I have like three most +useful things so I don't know what what + + align:start position:0% +useful things so I don't know what what + + + align:start position:0% +useful things so I don't know what what +that counts is but I think you have like + + align:start position:0% +that counts is but I think you have like + + + align:start position:0% +that counts is but I think you have like +firstly you have preparation like I + + align:start position:0% +firstly you have preparation like I + + + align:start position:0% +firstly you have preparation like I +learned a lot about the preparation + + align:start position:0% +learned a lot about the preparation + + + align:start position:0% +learned a lot about the preparation +process in a video which I previously + + align:start position:0% +process in a video which I previously + + + align:start position:0% +process in a video which I previously +did actually consider I used to think of + + align:start position:0% +did actually consider I used to think of + + + align:start position:0% +did actually consider I used to think of +people with their shaky cameras I didn't + + align:start position:0% +people with their shaky cameras I didn't + + + align:start position:0% +people with their shaky cameras I didn't +actually have an idea of what they're + + align:start position:0% +actually have an idea of what they're + + + align:start position:0% +actually have an idea of what they're +doing but most of the time they probably + + align:start position:0% +doing but most of the time they probably + + + align:start position:0% +doing but most of the time they probably +had a storyboard and it's not like by + + align:start position:0% +had a storyboard and it's not like by + + + align:start position:0% +had a storyboard and it's not like by +accident and then eventually becomes the + + align:start position:0% +accident and then eventually becomes the + + + align:start position:0% +accident and then eventually becomes the +idea of iteration so you have to keep + + align:start position:0% +idea of iteration so you have to keep + + + align:start position:0% +idea of iteration so you have to keep +keep trying different scenes many many + + align:start position:0% +keep trying different scenes many many + + + align:start position:0% +keep trying different scenes many many +takes and never never came to my mind + + align:start position:0% +takes and never never came to my mind + + + align:start position:0% +takes and never never came to my mind +and lastly like you have to have the + + align:start position:0% +and lastly like you have to have the + + + align:start position:0% +and lastly like you have to have the +passion for this if because you would do + + align:start position:0% +passion for this if because you would do + + + align:start position:0% +passion for this if because you would do +a lot of takes you'll be pretty sleepy + + align:start position:0% +a lot of takes you'll be pretty sleepy + + + align:start position:0% +a lot of takes you'll be pretty sleepy +after a while but you pretty you you + + align:start position:0% +after a while but you pretty you you + + + align:start position:0% +after a while but you pretty you you +love what you're done and I'm kind of + + align:start position:0% +love what you're done and I'm kind of + + + align:start position:0% +love what you're done and I'm kind of +excited to show what I have yeah yeah I + + align:start position:0% +excited to show what I have yeah yeah I + + + align:start position:0% +excited to show what I have yeah yeah I +guess the hardest part is there's so + + align:start position:0% +guess the hardest part is there's so + + + align:start position:0% +guess the hardest part is there's so +much content and there's a lot of + + align:start position:0% +much content and there's a lot of + + + align:start position:0% +much content and there's a lot of +technical stuff that I wish I knew like + + align:start position:0% +technical stuff that I wish I knew like + + + align:start position:0% +technical stuff that I wish I knew like +I wish I knew more about the the + + align:start position:0% +I wish I knew more about the the + + + align:start position:0% +I wish I knew more about the the +creative suite and like the software so + + align:start position:0% +creative suite and like the software so + + + align:start position:0% +creative suite and like the software so +i guess i was a limited in that + + align:start position:0% +i guess i was a limited in that + + + align:start position:0% +i guess i was a limited in that +department but other than that I think + + align:start position:0% +department but other than that I think + + + align:start position:0% +department but other than that I think +the preparation part gives me that + + align:start position:0% +the preparation part gives me that + + + align:start position:0% +the preparation part gives me that +background helps me to do a lot of + + align:start position:0% +background helps me to do a lot of + + + align:start position:0% +background helps me to do a lot of +different things yeah yeah thank you \ No newline at end of file diff --git a/KlAjiDivJoQ.txt b/KlAjiDivJoQ.txt new file mode 100644 index 0000000000000000000000000000000000000000..56a99aca1563e83fdf724da423bea88ad4d400cf --- /dev/null +++ b/KlAjiDivJoQ.txt @@ -0,0 +1,10747 @@ +align:start position:0% + +foreign + + align:start position:0% + + + + align:start position:0% + +today we are going to prove + + align:start position:0% +today we are going to prove + + + align:start position:0% +today we are going to prove +uh the theorem that I mentioned last + + align:start position:0% +uh the theorem that I mentioned last + + + align:start position:0% +uh the theorem that I mentioned last +time the Han banak theorem which is + + align:start position:0% +time the Han banak theorem which is + + + align:start position:0% +time the Han banak theorem which is +um a theorem about + + align:start position:0% +um a theorem about + + + align:start position:0% +um a theorem about +being able to extend uh bounded linear + + align:start position:0% +being able to extend uh bounded linear + + + align:start position:0% +being able to extend uh bounded linear +functionals on some Subspace of a norm + + align:start position:0% +functionals on some Subspace of a norm + + + align:start position:0% +functionals on some Subspace of a norm +space to all of the norm space and this + + align:start position:0% +space to all of the norm space and this + + + align:start position:0% +space to all of the norm space and this +will therefore you know answer the + + align:start position:0% +will therefore you know answer the + + + align:start position:0% +will therefore you know answer the +question that we posed at the beginning + + align:start position:0% +question that we posed at the beginning + + + align:start position:0% +question that we posed at the beginning +of this topic + + align:start position:0% +of this topic + + + align:start position:0% +of this topic +whether or not uh + + align:start position:0% +whether or not uh + + + align:start position:0% +whether or not uh +the Dual which is the space of all + + align:start position:0% +the Dual which is the space of all + + + align:start position:0% +the Dual which is the space of all +bounded linear functionals on a norm + + align:start position:0% +bounded linear functionals on a norm + + + align:start position:0% +bounded linear functionals on a norm +space is non-trivial for for every Norm + + align:start position:0% +space is non-trivial for for every Norm + + + align:start position:0% +space is non-trivial for for every Norm +space + + align:start position:0% +space + + + align:start position:0% +space +now one of the tools we're going to need + + align:start position:0% +now one of the tools we're going to need + + + align:start position:0% +now one of the tools we're going to need +is this uh + + align:start position:0% +is this uh + + + align:start position:0% +is this uh +Axiom or Lemma from set theory which is + + align:start position:0% +Axiom or Lemma from set theory which is + + + align:start position:0% +Axiom or Lemma from set theory which is +due to Zorn which is as following so + + align:start position:0% +due to Zorn which is as following so + + + align:start position:0% +due to Zorn which is as following so +um I'm gonna have to recall from the + + align:start position:0% +um I'm gonna have to recall from the + + + align:start position:0% +um I'm gonna have to recall from the +last lecture what some of these words + + align:start position:0% +last lecture what some of these words + + + align:start position:0% +last lecture what some of these words +mean but so Zorn's limma states that if + + align:start position:0% +mean but so Zorn's limma states that if + + + align:start position:0% +mean but so Zorn's limma states that if +every chain in a non-empty partially + + align:start position:0% +every chain in a non-empty partially + + + align:start position:0% +every chain in a non-empty partially +ordered set e has an upper bound then e + + align:start position:0% +ordered set e has an upper bound then e + + + align:start position:0% +ordered set e has an upper bound then e +has a maximal element so a partially + + align:start position:0% +has a maximal element so a partially + + + align:start position:0% +has a maximal element so a partially +ordered set e that means to set e with a + + align:start position:0% +ordered set e that means to set e with a + + + align:start position:0% +ordered set e that means to set e with a +relation that's basically like a less + + align:start position:0% +relation that's basically like a less + + + align:start position:0% +relation that's basically like a less +than or equal to okay that satisfies + + align:start position:0% +than or equal to okay that satisfies + + + align:start position:0% +than or equal to okay that satisfies +three properties so that it's like a + + align:start position:0% +three properties so that it's like a + + + align:start position:0% +three properties so that it's like a +extended less than or equal to + + align:start position:0% +extended less than or equal to + + + align:start position:0% +extended less than or equal to +and a chain is a subset of e so that any + + align:start position:0% +and a chain is a subset of e so that any + + + align:start position:0% +and a chain is a subset of e so that any +two elements in that subset can be + + align:start position:0% +two elements in that subset can be + + + align:start position:0% +two elements in that subset can be +um + + align:start position:0% +um + + + align:start position:0% +um +can be compared okay one is either + + align:start position:0% +can be compared okay one is either + + + align:start position:0% +can be compared okay one is either +bigger than or equal to the other + + align:start position:0% +bigger than or equal to the other + + + align:start position:0% +bigger than or equal to the other +or one is always bigger than or equal to + + align:start position:0% +or one is always bigger than or equal to + + + align:start position:0% +or one is always bigger than or equal to +the other okay + + align:start position:0% +the other okay + + + align:start position:0% +the other okay +and so this theorem says that if every + + align:start position:0% +and so this theorem says that if every + + + align:start position:0% +and so this theorem says that if every +chain of a partially ordered set has an + + align:start position:0% +chain of a partially ordered set has an + + + align:start position:0% +chain of a partially ordered set has an +upper bound that has a pretty uh + + align:start position:0% +upper bound that has a pretty uh + + + align:start position:0% +upper bound that has a pretty uh +you know + + align:start position:0% +you know + + + align:start position:0% +you know +clear meaning then e has a maximal + + align:start position:0% +clear meaning then e has a maximal + + + align:start position:0% +clear meaning then e has a maximal +element so a maximal element of e that + + align:start position:0% +element so a maximal element of e that + + + align:start position:0% +element so a maximal element of e that +means an element that is not less than + + align:start position:0% +means an element that is not less than + + + align:start position:0% +means an element that is not less than +or equal to something + + align:start position:0% +or equal to something + + + align:start position:0% +or equal to something +other than itself + + align:start position:0% +other than itself + + + align:start position:0% +other than itself +okay so anything bigger than or equal to + + align:start position:0% +okay so anything bigger than or equal to + + + align:start position:0% +okay so anything bigger than or equal to +this maximal element has to be that + + align:start position:0% +this maximal element has to be that + + + align:start position:0% +this maximal element has to be that +element + + align:start position:0% +element + + + align:start position:0% +element +okay a maximal element is not + + align:start position:0% +okay a maximal element is not + + + align:start position:0% +okay a maximal element is not +necessarily an upper bound okay a + + align:start position:0% +necessarily an upper bound okay a + + + align:start position:0% +necessarily an upper bound okay a +maximal element just means it cannot be + + align:start position:0% +maximal element just means it cannot be + + + align:start position:0% +maximal element just means it cannot be +uh you know nothing can get it get over + + align:start position:0% +uh you know nothing can get it get over + + + align:start position:0% +uh you know nothing can get it get over +its head + + align:start position:0% + + + + align:start position:0% + +all right and so as a warm-up we're + + align:start position:0% +all right and so as a warm-up we're + + + align:start position:0% +all right and so as a warm-up we're +going to use Zorn's Lemma to prove a + + align:start position:0% +going to use Zorn's Lemma to prove a + + + align:start position:0% +going to use Zorn's Lemma to prove a +fact about + + align:start position:0% +fact about + + + align:start position:0% +fact about +Vector spaces + + align:start position:0% +Vector spaces + + + align:start position:0% +Vector spaces +so + + align:start position:0% +so + + + align:start position:0% +so +a Hammel basis and I think I went over + + align:start position:0% +a Hammel basis and I think I went over + + + align:start position:0% +a Hammel basis and I think I went over +this at the end of class last time of a + + align:start position:0% +this at the end of class last time of a + + + align:start position:0% +this at the end of class last time of a +vector space V + + align:start position:0% +vector space V + + + align:start position:0% +vector space V +this is a linear independent set + + align:start position:0% +this is a linear independent set + + + align:start position:0% +this is a linear independent set +h + + align:start position:0% +h + + + align:start position:0% +h +such that every element of V is a finite + + align:start position:0% +such that every element of V is a finite + + + align:start position:0% +such that every element of V is a finite +linear combination of the elements from + + align:start position:0% +linear combination of the elements from + + + align:start position:0% +linear combination of the elements from +H so for example this set consisting of + + align:start position:0% +H so for example this set consisting of + + + align:start position:0% +H so for example this set consisting of +uh you know the vector 1 0 and the other + + align:start position:0% +uh you know the vector 1 0 and the other + + + align:start position:0% +uh you know the vector 1 0 and the other +and the vector 0 1 this is a Hamel basis + + align:start position:0% +and the vector 0 1 this is a Hamel basis + + + align:start position:0% +and the vector 0 1 this is a Hamel basis +for R2 every element in R2 can be + + align:start position:0% +for R2 every element in R2 can be + + + align:start position:0% +for R2 every element in R2 can be +written as a finite linear combination + + align:start position:0% +written as a finite linear combination + + + align:start position:0% +written as a finite linear combination +of these guys okay but you know + + align:start position:0% +of these guys okay but you know + + + align:start position:0% +of these guys okay but you know +and this is something uh + + align:start position:0% +and this is something uh + + + align:start position:0% +and this is something uh +you know the fact that finite + + align:start position:0% +you know the fact that finite + + + align:start position:0% +you know the fact that finite +dimensional spaces have bases is you + + align:start position:0% +dimensional spaces have bases is you + + + align:start position:0% +dimensional spaces have bases is you +know something you discuss in linear + + align:start position:0% +know something you discuss in linear + + + align:start position:0% +know something you discuss in linear +algebra but now we're in functional + + align:start position:0% +algebra but now we're in functional + + + align:start position:0% +algebra but now we're in functional +analysis which is linear algebra in + + align:start position:0% +analysis which is linear algebra in + + + align:start position:0% +analysis which is linear algebra in +infinite Dimensions + + align:start position:0% +infinite Dimensions + + + align:start position:0% +infinite Dimensions +um it's not so clear that every + + align:start position:0% +um it's not so clear that every + + + align:start position:0% +um it's not so clear that every +Vector space has a Hammel basis + + align:start position:0% +Vector space has a Hammel basis + + + align:start position:0% +Vector space has a Hammel basis +and so what we're going to do is we're + + align:start position:0% +and so what we're going to do is we're + + + align:start position:0% +and so what we're going to do is we're +going to apply Zorn's Lemma to prove + + align:start position:0% +going to apply Zorn's Lemma to prove + + + align:start position:0% +going to apply Zorn's Lemma to prove +that every Vector space does have a heml + + align:start position:0% +that every Vector space does have a heml + + + align:start position:0% +that every Vector space does have a heml +basis so this is the following theorem + + align:start position:0% +basis so this is the following theorem + + + align:start position:0% +basis so this is the following theorem +and this argument will kind of + + align:start position:0% +and this argument will kind of + + + align:start position:0% +and this argument will kind of +um + + align:start position:0% +um + + + align:start position:0% +um +be a warm-up for how we'll apply Zorn to + + align:start position:0% +be a warm-up for how we'll apply Zorn to + + + align:start position:0% +be a warm-up for how we'll apply Zorn to +to prove the Han banak theorem so + + align:start position:0% + + + + align:start position:0% + +if B is a vector space + + align:start position:0% +if B is a vector space + + + align:start position:0% +if B is a vector space +then V has + + align:start position:0% +then V has + + + align:start position:0% +then V has +a + + align:start position:0% + + + + align:start position:0% + +Hammel basis + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so + + align:start position:0% + + + + align:start position:0% + +for the proof + + align:start position:0% +for the proof + + + align:start position:0% +for the proof +um + + align:start position:0% +um + + + align:start position:0% +um +I am going to apply Zorn so I need to + + align:start position:0% +I am going to apply Zorn so I need to + + + align:start position:0% +I am going to apply Zorn so I need to +have some ordered set and my ordered set + + align:start position:0% +have some ordered set and my ordered set + + + align:start position:0% +have some ordered set and my ordered set +is going to be + + align:start position:0% +is going to be + + + align:start position:0% +is going to be +uh + + align:start position:0% +uh + + + align:start position:0% +uh +let e be the set of all uh + + align:start position:0% + + + + align:start position:0% + +linearly + + align:start position:0% + + + + align:start position:0% + +independent + + align:start position:0% + + + + align:start position:0% + +subsets of V + + align:start position:0% + + + + align:start position:0% + +and we're going to Define an order on E + + align:start position:0% +and we're going to Define an order on E + + + align:start position:0% +and we're going to Define an order on E +so e is the set of all subsets of V that + + align:start position:0% +so e is the set of all subsets of V that + + + align:start position:0% +so e is the set of all subsets of V that +are linearly independent + + align:start position:0% +are linearly independent + + + align:start position:0% +are linearly independent +and we Define + + align:start position:0% + + + + align:start position:0% + +partial order on E + + align:start position:0% + + + + align:start position:0% + +by + + align:start position:0% + + + + align:start position:0% + +inclusion so these are just the elements + + align:start position:0% +inclusion so these are just the elements + + + align:start position:0% +inclusion so these are just the elements +of e are subsets of V so we'll say one + + align:start position:0% +of e are subsets of V so we'll say one + + + align:start position:0% +of e are subsets of V so we'll say one +subset is less than or equal to another + + align:start position:0% +subset is less than or equal to another + + + align:start position:0% +subset is less than or equal to another +subset if one is included in the other + + align:start position:0% +subset if one is included in the other + + + align:start position:0% +subset if one is included in the other +so uh + + align:start position:0% + + + + align:start position:0% + +e and e Prime and E + + align:start position:0% + + + + align:start position:0% + +then we'll say e is less than or equal + + align:start position:0% +then we'll say e is less than or equal + + + align:start position:0% +then we'll say e is less than or equal +to e Prime if and only if this subset of + + align:start position:0% +to e Prime if and only if this subset of + + + align:start position:0% +to e Prime if and only if this subset of +e this subset of v e is a subset of e + + align:start position:0% +e this subset of v e is a subset of e + + + align:start position:0% +e this subset of v e is a subset of e +Prime + + align:start position:0% +Prime + + + align:start position:0% +Prime +okay and again so I think I said this in + + align:start position:0% +okay and again so I think I said this in + + + align:start position:0% +okay and again so I think I said this in +a previous lecture I'm kind of used to + + align:start position:0% +a previous lecture I'm kind of used to + + + align:start position:0% +a previous lecture I'm kind of used to +using this notation for + + align:start position:0% +using this notation for + + + align:start position:0% +using this notation for +a subset not necessarily a strict subset + + align:start position:0% +a subset not necessarily a strict subset + + + align:start position:0% +a subset not necessarily a strict subset +just from teaching 18100a last semester + + align:start position:0% +just from teaching 18100a last semester + + + align:start position:0% +just from teaching 18100a last semester +so this does not mean a strict subset so + + align:start position:0% +so this does not mean a strict subset so + + + align:start position:0% +so this does not mean a strict subset so +maybe you know you know put that in + + align:start position:0% +maybe you know you know put that in + + + align:start position:0% +maybe you know you know put that in +there + + align:start position:0% + + + + align:start position:0% + +okay so this is my partially ordered set + + align:start position:0% +okay so this is my partially ordered set + + + align:start position:0% +okay so this is my partially ordered set +which I hope to apply the Zorn Zorn's + + align:start position:0% +which I hope to apply the Zorn Zorn's + + + align:start position:0% +which I hope to apply the Zorn Zorn's +Lemma on and then what I will show is + + align:start position:0% +Lemma on and then what I will show is + + + align:start position:0% +Lemma on and then what I will show is +that the maximal element of this set + + align:start position:0% +that the maximal element of this set + + + align:start position:0% +that the maximal element of this set +once I show it exists in fact has to be + + align:start position:0% +once I show it exists in fact has to be + + + align:start position:0% +once I show it exists in fact has to be +a hammer basis for V + + align:start position:0% +a hammer basis for V + + + align:start position:0% +a hammer basis for V +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so now we'll apply Zorn + + align:start position:0% + + + + align:start position:0% + +towards + + align:start position:0% + + + + align:start position:0% + +find Zorn + + align:start position:0% + + + + align:start position:0% + +let's see + + align:start position:0% + + + + align:start position:0% + +be a chain in e + + align:start position:0% +be a chain in e + + + align:start position:0% +be a chain in e +okay that means any two elements of C + + align:start position:0% +okay that means any two elements of C + + + align:start position:0% +okay that means any two elements of C +can be compared + + align:start position:0% + + + + align:start position:0% + +to find little C to be equal to + + align:start position:0% +to find little C to be equal to + + + align:start position:0% +to find little C to be equal to +Union overall + + align:start position:0% +Union overall + + + align:start position:0% +Union overall +e and capital c e + + align:start position:0% +e and capital c e + + + align:start position:0% +e and capital c e +all right so each of these Little E's + + align:start position:0% +all right so each of these Little E's + + + align:start position:0% +all right so each of these Little E's +this is a subset of V consisting of + + align:start position:0% +this is a subset of V consisting of + + + align:start position:0% +this is a subset of V consisting of +linearly independent elements and now + + align:start position:0% +linearly independent elements and now + + + align:start position:0% +linearly independent elements and now +what I'm taking little C to B is the + + align:start position:0% +what I'm taking little C to B is the + + + align:start position:0% +what I'm taking little C to B is the +union of all these subsets of linearly + + align:start position:0% +union of all these subsets of linearly + + + align:start position:0% +union of all these subsets of linearly +independent elements + + align:start position:0% +independent elements + + + align:start position:0% +independent elements +okay and I claim that this is a a + + align:start position:0% +okay and I claim that this is a a + + + align:start position:0% +okay and I claim that this is a a +linearly independent subset + + align:start position:0% + + + + align:start position:0% + +which you know since + + align:start position:0% +which you know since + + + align:start position:0% +which you know since +this + + align:start position:0% +this + + + align:start position:0% +this +subset or of V contains every element of + + align:start position:0% +subset or of V contains every element of + + + align:start position:0% +subset or of V contains every element of +c means C is bigger than or equal to all + + align:start position:0% +c means C is bigger than or equal to all + + + align:start position:0% +c means C is bigger than or equal to all +of E + + align:start position:0% + + + + align:start position:0% + +thus + + align:start position:0% + + + + align:start position:0% + +C is + + align:start position:0% +C is + + + align:start position:0% +C is +an upper bound + + align:start position:0% + + + + align:start position:0% + +for C okay + + align:start position:0% + + + + align:start position:0% + +so we just need to show that little c is + + align:start position:0% +so we just need to show that little c is + + + align:start position:0% +so we just need to show that little c is +now linearly independent subset and + + align:start position:0% +now linearly independent subset and + + + align:start position:0% +now linearly independent subset and +therefore + + align:start position:0% +therefore + + + align:start position:0% +therefore +um all of these e's in this Capital C + + align:start position:0% +um all of these e's in this Capital C + + + align:start position:0% +um all of these e's in this Capital C +are bounded above by C and therefore C + + align:start position:0% +are bounded above by C and therefore C + + + align:start position:0% +are bounded above by C and therefore C +is an upper Bound for Capital C + + align:start position:0% + + + + align:start position:0% + +now + + align:start position:0% +now + + + align:start position:0% +now +to show it's a linearly independent + + align:start position:0% +to show it's a linearly independent + + + align:start position:0% +to show it's a linearly independent +subset we're going to use the fact that + + align:start position:0% +subset we're going to use the fact that + + + align:start position:0% +subset we're going to use the fact that +Capital C is a chain that you can always + + align:start position:0% +Capital C is a chain that you can always + + + align:start position:0% +Capital C is a chain that you can always +compare two things all right so let's + + align:start position:0% +compare two things all right so let's + + + align:start position:0% +compare two things all right so let's +show that little C is a linearly + + align:start position:0% +show that little C is a linearly + + + align:start position:0% +show that little C is a linearly +independent subset that's uh something + + align:start position:0% +independent subset that's uh something + + + align:start position:0% +independent subset that's uh something +very specific so let B1 up to V in + + align:start position:0% +very specific so let B1 up to V in + + + align:start position:0% +very specific so let B1 up to V in +be in + + align:start position:0% +be in + + + align:start position:0% +be in +um + + align:start position:0% +um + + + align:start position:0% +um +little C + + align:start position:0% + + + + align:start position:0% + +then there exists E1 E2 + + align:start position:0% +then there exists E1 E2 + + + align:start position:0% +then there exists E1 E2 +be in in capital c + + align:start position:0% +be in in capital c + + + align:start position:0% +be in in capital c +so little C is the union of all the E's + + align:start position:0% +so little C is the union of all the E's + + + align:start position:0% +so little C is the union of all the E's +so these have to come from somewhere + + align:start position:0% +so these have to come from somewhere + + + align:start position:0% +so these have to come from somewhere +such that uh for all J + + align:start position:0% +such that uh for all J + + + align:start position:0% +such that uh for all J +B J is in EJ + + align:start position:0% + + + + align:start position:0% + +now + + align:start position:0% +now + + + align:start position:0% +now +um it's not difficult to show by + + align:start position:0% +um it's not difficult to show by + + + align:start position:0% +um it's not difficult to show by +induction that since I can compare any + + align:start position:0% +induction that since I can compare any + + + align:start position:0% +induction that since I can compare any +two elements in C I can compare + + align:start position:0% +two elements in C I can compare + + + align:start position:0% +two elements in C I can compare +uh any n elements + + align:start position:0% +uh any n elements + + + align:start position:0% +uh any n elements +of C meaning I can actually order any + + align:start position:0% +of C meaning I can actually order any + + + align:start position:0% +of C meaning I can actually order any +finitely many elements in C right so + + align:start position:0% +finitely many elements in C right so + + + align:start position:0% +finitely many elements in C right so +again linear so to say this is a + + align:start position:0% +again linear so to say this is a + + + align:start position:0% +again linear so to say this is a +chain means I can always order two + + align:start position:0% +chain means I can always order two + + + align:start position:0% +chain means I can always order two +elements + + align:start position:0% +elements + + + align:start position:0% +elements +but by induction it's not difficult to + + align:start position:0% +but by induction it's not difficult to + + + align:start position:0% +but by induction it's not difficult to +show I can always order n elements of C + + align:start position:0% +show I can always order n elements of C + + + align:start position:0% +show I can always order n elements of C +so I'm just going to skip to that and + + align:start position:0% +so I'm just going to skip to that and + + + align:start position:0% +so I'm just going to skip to that and +I'll leave it to you + + align:start position:0% +I'll leave it to you + + + align:start position:0% +I'll leave it to you +um + + align:start position:0% +um + + + align:start position:0% +um +meaning that I can always find a biggest + + align:start position:0% +meaning that I can always find a biggest + + + align:start position:0% +meaning that I can always find a biggest +element out of any finite collection of + + align:start position:0% +element out of any finite collection of + + + align:start position:0% +element out of any finite collection of +these guys + + align:start position:0% +these guys + + + align:start position:0% +these guys +all right + + align:start position:0% +all right + + + align:start position:0% +all right +so + + align:start position:0% +so + + + align:start position:0% +so +since C is + + align:start position:0% + + + + align:start position:0% + +chain + + align:start position:0% +chain + + + align:start position:0% +chain +there exists capital j + + align:start position:0% +there exists capital j + + + align:start position:0% +there exists capital j +such that for all J equals one up to n + + align:start position:0% +such that for all J equals one up to n + + + align:start position:0% +such that for all J equals one up to n +e j + + align:start position:0% +e j + + + align:start position:0% +e j +is less than or equal to E capital j + + align:start position:0% +is less than or equal to E capital j + + + align:start position:0% +is less than or equal to E capital j +which again remember this means that e j + + align:start position:0% +which again remember this means that e j + + + align:start position:0% +which again remember this means that e j +is a subset of E capital J just by how + + align:start position:0% +is a subset of E capital J just by how + + + align:start position:0% +is a subset of E capital J just by how +we've defined this partial order + + align:start position:0% + + + + align:start position:0% + +and therefore + + align:start position:0% +and therefore + + + align:start position:0% +and therefore +since all of these ejs for J from 1 to n + + align:start position:0% +since all of these ejs for J from 1 to n + + + align:start position:0% +since all of these ejs for J from 1 to n +are contained in this e sub capital j + + align:start position:0% +are contained in this e sub capital j + + + align:start position:0% +are contained in this e sub capital j +that means that V1 up to VN are n e + + align:start position:0% +that means that V1 up to VN are n e + + + align:start position:0% +that means that V1 up to VN are n e +capital j + + align:start position:0% +capital j + + + align:start position:0% +capital j +all right + + align:start position:0% + + + + align:start position:0% + +so I had this uh finitely many from C I + + align:start position:0% +so I had this uh finitely many from C I + + + align:start position:0% +so I had this uh finitely many from C I +can always compare any two of them and + + align:start position:0% +can always compare any two of them and + + + align:start position:0% +can always compare any two of them and +therefore I pick the biggest linearly + + align:start position:0% +therefore I pick the biggest linearly + + + align:start position:0% +therefore I pick the biggest linearly +independent subset out of this finitely + + align:start position:0% +independent subset out of this finitely + + + align:start position:0% +independent subset out of this finitely +mini and all of these vectors have to + + align:start position:0% +mini and all of these vectors have to + + + align:start position:0% +mini and all of these vectors have to +then come from that linearly independent + + align:start position:0% +then come from that linearly independent + + + align:start position:0% +then come from that linearly independent +subset + + align:start position:0% +subset + + + align:start position:0% +subset +and therefore + + align:start position:0% +and therefore + + + align:start position:0% +and therefore +since this is a linearly independent + + align:start position:0% +since this is a linearly independent + + + align:start position:0% +since this is a linearly independent +subset that means these are linearly + + align:start position:0% +subset that means these are linearly + + + align:start position:0% +subset that means these are linearly +independent + + align:start position:0% + + + + align:start position:0% + +or linearly + + align:start position:0% +or linearly + + + align:start position:0% +or linearly +independent + + align:start position:0% + + + + align:start position:0% + +since e j + + align:start position:0% +since e j + + + align:start position:0% +since e j +is a linearly independent subset okay + + align:start position:0% + + + + align:start position:0% + +and so we've shown every finite + + align:start position:0% +and so we've shown every finite + + + align:start position:0% +and so we've shown every finite +collection of vectors and C is linearly + + align:start position:0% +collection of vectors and C is linearly + + + align:start position:0% +collection of vectors and C is linearly +independent so we've concluded that + + align:start position:0% +independent so we've concluded that + + + align:start position:0% +independent so we've concluded that +little C is a + + align:start position:0% + + + + align:start position:0% + +collection of linearly independent + + align:start position:0% +collection of linearly independent + + + align:start position:0% +collection of linearly independent +vectors + + align:start position:0% + + + + align:start position:0% + +Okay so we've now shown that the + + align:start position:0% +Okay so we've now shown that the + + + align:start position:0% +Okay so we've now shown that the +hypotheses of Zorn are verified that + + align:start position:0% +hypotheses of Zorn are verified that + + + align:start position:0% +hypotheses of Zorn are verified that +every chain has an upper bound + + align:start position:0% +every chain has an upper bound + + + align:start position:0% +every chain has an upper bound +and therefore this set e has a maximal + + align:start position:0% +and therefore this set e has a maximal + + + align:start position:0% +and therefore this set e has a maximal +element + + align:start position:0% + + + + align:start position:0% + +Max + + align:start position:0% + + + + align:start position:0% + +element which I'll call H + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so I claim that H now + + align:start position:0% +so I claim that H now + + + align:start position:0% +so I claim that H now +spans uh the vector space V meaning + + align:start position:0% +spans uh the vector space V meaning + + + align:start position:0% +spans uh the vector space V meaning +every element of V is can be written as + + align:start position:0% +every element of V is can be written as + + + align:start position:0% +every element of V is can be written as +a finite linear combination of of + + align:start position:0% +a finite linear combination of of + + + align:start position:0% +a finite linear combination of of +elements of H + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% + + + + align:start position:0% + +claim + + align:start position:0% +claim + + + align:start position:0% +claim +and H + + align:start position:0% +and H + + + align:start position:0% +and H +spans V so when I say h spans V that's + + align:start position:0% +spans V so when I say h spans V that's + + + align:start position:0% +spans V so when I say h spans V that's +just a short way of saying that every + + align:start position:0% +just a short way of saying that every + + + align:start position:0% +just a short way of saying that every +element of V can be written as a finite + + align:start position:0% +element of V can be written as a finite + + + align:start position:0% +element of V can be written as a finite +linear combination of elements of H + + align:start position:0% +linear combination of elements of H + + + align:start position:0% +linear combination of elements of H +so suppose not + + align:start position:0% + + + + align:start position:0% + +then + + align:start position:0% +then + + + align:start position:0% +then +there exists an element V in capital V + + align:start position:0% + + + + align:start position:0% + +such that + + align:start position:0% +such that + + + align:start position:0% +such that +uh + + align:start position:0% +uh + + + align:start position:0% +uh +the + + align:start position:0% + + + + align:start position:0% + +cannot be + + align:start position:0% + + + + align:start position:0% + +written as a + + align:start position:0% + + + + align:start position:0% + +finite + + align:start position:0% +finite + + + align:start position:0% +finite +linear combination + + align:start position:0% + + + + align:start position:0% + +of elements + + align:start position:0% +of elements + + + align:start position:0% +of elements +h + + align:start position:0% +h + + + align:start position:0% +h +now it's you know something from linear + + align:start position:0% +now it's you know something from linear + + + align:start position:0% +now it's you know something from linear +algebra I'm sure they went over this + + align:start position:0% +algebra I'm sure they went over this + + + align:start position:0% +algebra I'm sure they went over this +before but if I have a linearly + + align:start position:0% +before but if I have a linearly + + + align:start position:0% +before but if I have a linearly +independent subset and an element that + + align:start position:0% +independent subset and an element that + + + align:start position:0% +independent subset and an element that +can't be written as a finite linear + + align:start position:0% +can't be written as a finite linear + + + align:start position:0% +can't be written as a finite linear +combination of elements from that subset + + align:start position:0% +combination of elements from that subset + + + align:start position:0% +combination of elements from that subset +than just by adding that element I now + + align:start position:0% +than just by adding that element I now + + + align:start position:0% +than just by adding that element I now +obtain a new linearly independent subset + + align:start position:0% + + + + align:start position:0% + +and therefore I conclude that the + + align:start position:0% + + + + align:start position:0% + +set H Union B + + align:start position:0% +set H Union B + + + align:start position:0% +set H Union B +is linearly independent + + align:start position:0% + + + + align:start position:0% + +linearly independent + + align:start position:0% + + + + align:start position:0% + +subset + + align:start position:0% +subset + + + align:start position:0% +subset +of V + + align:start position:0% + + + + align:start position:0% + +but then + + align:start position:0% + + + + align:start position:0% + +H will be less than meaning it is less + + align:start position:0% +H will be less than meaning it is less + + + align:start position:0% +H will be less than meaning it is less +than or equal to but not equal to + + align:start position:0% + + + + align:start position:0% + +which implies h + + align:start position:0% +which implies h + + + align:start position:0% +which implies h +is not maximal + + align:start position:0% + + + + align:start position:0% + +which is a contradiction right remember + + align:start position:0% +which is a contradiction right remember + + + align:start position:0% +which is a contradiction right remember +H was supposed to be the maximal element + + align:start position:0% +H was supposed to be the maximal element + + + align:start position:0% +H was supposed to be the maximal element +of e nothing sits above H and if we + + align:start position:0% +of e nothing sits above H and if we + + + align:start position:0% +of e nothing sits above H and if we +assume that H does not span V then we + + align:start position:0% +assume that H does not span V then we + + + align:start position:0% +assume that H does not span V then we +can tack on to H something making a + + align:start position:0% +can tack on to H something making a + + + align:start position:0% +can tack on to H something making a +bigger linearly independent subset of v + + align:start position:0% +bigger linearly independent subset of v + + + align:start position:0% +bigger linearly independent subset of v +and that uh + + align:start position:0% +and that uh + + + align:start position:0% +and that uh +results in a contradiction so thus that + + align:start position:0% +results in a contradiction so thus that + + + align:start position:0% +results in a contradiction so thus that +must contradict our initial assumption + + align:start position:0% +must contradict our initial assumption + + + align:start position:0% +must contradict our initial assumption +initial assumption + + align:start position:0% +initial assumption + + + align:start position:0% +initial assumption +that H did not span V so + + align:start position:0% + + + + align:start position:0% + +and therefore by definition it's a + + align:start position:0% +and therefore by definition it's a + + + align:start position:0% +and therefore by definition it's a +handle basis + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +all right + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% +um + + + align:start position:0% +um +Okay so we've seen this kind of exercise + + align:start position:0% +Okay so we've seen this kind of exercise + + + align:start position:0% +Okay so we've seen this kind of exercise +first exercise of using this very uh + + align:start position:0% +first exercise of using this very uh + + + align:start position:0% +first exercise of using this very uh +powerful weapon Zorn + + align:start position:0% +powerful weapon Zorn + + + align:start position:0% +powerful weapon Zorn +Zorn's Lemma to to prove this fact that + + align:start position:0% +Zorn's Lemma to to prove this fact that + + + align:start position:0% +Zorn's Lemma to to prove this fact that +every Vector space has a Hammel basis + + align:start position:0% +every Vector space has a Hammel basis + + + align:start position:0% +every Vector space has a Hammel basis +and now we're going to use it to prove + + align:start position:0% +and now we're going to use it to prove + + + align:start position:0% +and now we're going to use it to prove +the harmonic theorem so let me State uh + + align:start position:0% +the harmonic theorem so let me State uh + + + align:start position:0% +the harmonic theorem so let me State uh +the Han banak theorem for you + + align:start position:0% +the Han banak theorem for you + + + align:start position:0% +the Han banak theorem for you +and then we're going to discuss the + + align:start position:0% +and then we're going to discuss the + + + align:start position:0% +and then we're going to discuss the +strategy actually what I'm going to do + + align:start position:0% +strategy actually what I'm going to do + + + align:start position:0% +strategy actually what I'm going to do +is I'm going to State the hanbanek + + align:start position:0% +is I'm going to State the hanbanek + + + align:start position:0% +is I'm going to State the hanbanek +theorem I'm going to State a limma and + + align:start position:0% +theorem I'm going to State a limma and + + + align:start position:0% +theorem I'm going to State a limma and +then I'm going to give you how uh + + align:start position:0% +then I'm going to give you how uh + + + align:start position:0% +then I'm going to give you how uh +what the the plan is to proving for + + align:start position:0% +what the the plan is to proving for + + + align:start position:0% +what the the plan is to proving for +proving the harmonic theorem + + align:start position:0% +proving the harmonic theorem + + + align:start position:0% +proving the harmonic theorem +so the harmonic theorem is + + align:start position:0% +so the harmonic theorem is + + + align:start position:0% +so the harmonic theorem is +V + + align:start position:0% +V + + + align:start position:0% +V +is a + + align:start position:0% + + + + align:start position:0% + +Norm space + + align:start position:0% + + + + align:start position:0% + +m is a + + align:start position:0% + + + + align:start position:0% + +Subspace of V + + align:start position:0% + + + + align:start position:0% + +and U going from m + + align:start position:0% +and U going from m + + + align:start position:0% +and U going from m +to see + + align:start position:0% + + + + align:start position:0% + +is linear + + align:start position:0% +is linear + + + align:start position:0% +is linear +such that so it's a bounded linear + + align:start position:0% +such that so it's a bounded linear + + + align:start position:0% +such that so it's a bounded linear +functional + + align:start position:0% + + + + align:start position:0% + +well T and M + + align:start position:0% +well T and M + + + align:start position:0% +well T and M +U of T + + align:start position:0% +U of T + + + align:start position:0% +U of T +so this is now a complex number it's + + align:start position:0% +so this is now a complex number it's + + + align:start position:0% +so this is now a complex number it's +absolute value is less than or equal to + + align:start position:0% +absolute value is less than or equal to + + + align:start position:0% +absolute value is less than or equal to +constant times + + align:start position:0% +constant times + + + align:start position:0% +constant times +Norm of t + + align:start position:0% + + + + align:start position:0% + +then there exists + + align:start position:0% +then there exists + + + align:start position:0% +then there exists +a continuous extension of you to the + + align:start position:0% +a continuous extension of you to the + + + align:start position:0% +a continuous extension of you to the +entire space and a continuous extension + + align:start position:0% +entire space and a continuous extension + + + align:start position:0% +entire space and a continuous extension +that has the same constant here so + + align:start position:0% +that has the same constant here so + + + align:start position:0% +that has the same constant here so +remember this is think of this as being + + align:start position:0% +remember this is think of this as being + + + align:start position:0% +remember this is think of this as being +the norm of little U and so we can + + align:start position:0% +the norm of little U and so we can + + + align:start position:0% +the norm of little U and so we can +extend it to a bounded linear functional + + align:start position:0% +extend it to a bounded linear functional + + + align:start position:0% +extend it to a bounded linear functional +with the same Norm essentially and there + + align:start position:0% +with the same Norm essentially and there + + + align:start position:0% +with the same Norm essentially and there +exists a capital u + + align:start position:0% + + + + align:start position:0% + +which is a + + align:start position:0% + + + + align:start position:0% + +bounded linear functional from V to C so + + align:start position:0% +bounded linear functional from V to C so + + + align:start position:0% +bounded linear functional from V to C so +it's an element of the Dual space + + align:start position:0% + + + + align:start position:0% + +such that now for all + + align:start position:0% +such that now for all + + + align:start position:0% +such that now for all +T and V + + align:start position:0% + + + + align:start position:0% + +U of T is less than or equal to the same + + align:start position:0% +U of T is less than or equal to the same + + + align:start position:0% +U of T is less than or equal to the same +constant T and I should have said before + + align:start position:0% +constant T and I should have said before + + + align:start position:0% +constant T and I should have said before +such that capital u when I restrict to M + + align:start position:0% +such that capital u when I restrict to M + + + align:start position:0% +such that capital u when I restrict to M +gives me little U + + align:start position:0% +gives me little U + + + align:start position:0% +gives me little U +and for all T and V Capital U of T is + + align:start position:0% +and for all T and V Capital U of T is + + + align:start position:0% +and for all T and V Capital U of T is +less than or equal to a constant times + + align:start position:0% +less than or equal to a constant times + + + align:start position:0% +less than or equal to a constant times +the norm of t + + align:start position:0% +the norm of t + + + align:start position:0% +the norm of t +all right so this is a + + align:start position:0% +all right so this is a + + + align:start position:0% +all right so this is a +I should have put this here at the start + + align:start position:0% +I should have put this here at the start + + + align:start position:0% +I should have put this here at the start +of the theorem but this is the + + align:start position:0% + + + + align:start position:0% + +on bionic theorem + + align:start position:0% +on bionic theorem + + + align:start position:0% +on bionic theorem +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and you know this is a very very useful + + align:start position:0% +and you know this is a very very useful + + + align:start position:0% +and you know this is a very very useful +theorem to have + + align:start position:0% +theorem to have + + + align:start position:0% +theorem to have +in fact in the exercises you can use + + align:start position:0% +in fact in the exercises you can use + + + align:start position:0% +in fact in the exercises you can use +this theorem to prove that the Dual of + + align:start position:0% +this theorem to prove that the Dual of + + + align:start position:0% +this theorem to prove that the Dual of +little L Infinity is not little L1 + + align:start position:0% +little L Infinity is not little L1 + + + align:start position:0% +little L Infinity is not little L1 +okay so remember we from the second + + align:start position:0% +okay so remember we from the second + + + align:start position:0% +okay so remember we from the second +assignment and from what I've said in + + align:start position:0% +assignment and from what I've said in + + + align:start position:0% +assignment and from what I've said in +lectures you know the Duel of little LP + + align:start position:0% +lectures you know the Duel of little LP + + + align:start position:0% +lectures you know the Duel of little LP +is little lq where one over P plus one + + align:start position:0% +is little lq where one over P plus one + + + align:start position:0% +is little lq where one over P plus one +over Q equals one as long as p is bigger + + align:start position:0% +over Q equals one as long as p is bigger + + + align:start position:0% +over Q equals one as long as p is bigger +than or equal to one and less than + + align:start position:0% +than or equal to one and less than + + + align:start position:0% +than or equal to one and less than +infinity and it doesn't work for p + + align:start position:0% +infinity and it doesn't work for p + + + align:start position:0% +infinity and it doesn't work for p +equals infinity so using the harmonic + + align:start position:0% +equals infinity so using the harmonic + + + align:start position:0% +equals infinity so using the harmonic +theorem you can show that why it doesn't + + align:start position:0% +theorem you can show that why it doesn't + + + align:start position:0% +theorem you can show that why it doesn't +work for for little L infinity and + + align:start position:0% +work for for little L infinity and + + + align:start position:0% +work for for little L infinity and +that'll be in the assignment + + align:start position:0% +that'll be in the assignment + + + align:start position:0% +that'll be in the assignment +foreign + + align:start position:0% + + + + align:start position:0% + +so um + + align:start position:0% +so um + + + align:start position:0% +so um +now just for I'm gonna so I don't have + + align:start position:0% +now just for I'm gonna so I don't have + + + align:start position:0% +now just for I'm gonna so I don't have +to keep writing all of this over and + + align:start position:0% +to keep writing all of this over and + + + align:start position:0% +to keep writing all of this over and +over again + + align:start position:0% +over again + + + align:start position:0% +over again +I'm going to refer to this as + + align:start position:0% +I'm going to refer to this as + + + align:start position:0% +I'm going to refer to this as +U is + + align:start position:0% + + + + align:start position:0% + +a continuous + + align:start position:0% + + + + align:start position:0% + +extension + + align:start position:0% +extension + + + align:start position:0% +extension +of little U okay although that's not + + align:start position:0% +of little U okay although that's not + + + align:start position:0% +of little U okay although that's not +quite precise because we are extending + + align:start position:0% +quite precise because we are extending + + + align:start position:0% +quite precise because we are extending +little U + + align:start position:0% +little U + + + align:start position:0% +little U +to a continuous + + align:start position:0% +to a continuous + + + align:start position:0% +to a continuous +so a bounded linear operator on V but + + align:start position:0% +so a bounded linear operator on V but + + + align:start position:0% +so a bounded linear operator on V but +we're also + + align:start position:0% +we're also + + + align:start position:0% +we're also +extending it so that the + + align:start position:0% +extending it so that the + + + align:start position:0% +extending it so that the +capital u satisfies the same bound as + + align:start position:0% +capital u satisfies the same bound as + + + align:start position:0% +capital u satisfies the same bound as +little U + + align:start position:0% +little U + + + align:start position:0% +little U +okay + + align:start position:0% + + + + align:start position:0% + +all right so this is a little imprecise + + align:start position:0% +all right so this is a little imprecise + + + align:start position:0% +all right so this is a little imprecise +but I think you should you know get my + + align:start position:0% +but I think you should you know get my + + + align:start position:0% +but I think you should you know get my +meaning + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +um so + + align:start position:0% +um so + + + align:start position:0% +um so +this assumption let me denote by star + + align:start position:0% +this assumption let me denote by star + + + align:start position:0% +this assumption let me denote by star +namely that we have a Subspace and we + + align:start position:0% +namely that we have a Subspace and we + + + align:start position:0% +namely that we have a Subspace and we +have a bounded linear functional on this + + align:start position:0% +have a bounded linear functional on this + + + align:start position:0% +have a bounded linear functional on this +Subspace that satisfies this bound so + + align:start position:0% +Subspace that satisfies this bound so + + + align:start position:0% +Subspace that satisfies this bound so +um + + align:start position:0% +um + + + align:start position:0% +um +I'm not going to prove the harmonic + + align:start position:0% +I'm not going to prove the harmonic + + + align:start position:0% +I'm not going to prove the harmonic +theorem just yet I'm going to prove a + + align:start position:0% +theorem just yet I'm going to prove a + + + align:start position:0% +theorem just yet I'm going to prove a +Lemma or I'm going to State a Lima and + + align:start position:0% +Lemma or I'm going to State a Lima and + + + align:start position:0% +Lemma or I'm going to State a Lima and +then tell you how we're going to prove + + align:start position:0% +then tell you how we're going to prove + + + align:start position:0% +then tell you how we're going to prove +use it to prove the harmonic theorem so + + align:start position:0% +use it to prove the harmonic theorem so + + + align:start position:0% +use it to prove the harmonic theorem so +um + + align:start position:0% + + + + align:start position:0% + +actually you know what we'll say that uh + + align:start position:0% +actually you know what we'll say that uh + + + align:start position:0% +actually you know what we'll say that uh +slightly different I'm not going to use + + align:start position:0% +slightly different I'm not going to use + + + align:start position:0% +slightly different I'm not going to use +that + + align:start position:0% + + + + align:start position:0% + +so if V is a normed + + align:start position:0% +so if V is a normed + + + align:start position:0% +so if V is a normed +space + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% +um + + + align:start position:0% +um +a subset of V is a Subspace + + align:start position:0% + + + + align:start position:0% + +and you + + align:start position:0% +and you + + + align:start position:0% +and you +from M to C is + + align:start position:0% +from M to C is + + + align:start position:0% +from M to C is +linear + + align:start position:0% +linear + + + align:start position:0% +linear +such that + + align:start position:0% +such that + + + align:start position:0% +such that +little U of T + + align:start position:0% +little U of T + + + align:start position:0% +little U of T +is less than or equal to + + align:start position:0% +is less than or equal to + + + align:start position:0% +is less than or equal to +constant times the norm of T So for all + + align:start position:0% +constant times the norm of T So for all + + + align:start position:0% +constant times the norm of T So for all +T and M + + align:start position:0% + + + + align:start position:0% + +um and you know what let me + + align:start position:0% + + + + align:start position:0% + +I think the difference between capital u + + align:start position:0% +I think the difference between capital u + + + align:start position:0% +I think the difference between capital u +and little U is clear enough + + align:start position:0% +and little U is clear enough + + + align:start position:0% +and little U is clear enough +then I can extend it at least + + align:start position:0% +then I can extend it at least + + + align:start position:0% +then I can extend it at least +in One Direction so in other words + + align:start position:0% +in One Direction so in other words + + + align:start position:0% +in One Direction so in other words +um + + align:start position:0% + + + + align:start position:0% + +then + + align:start position:0% + + + + align:start position:0% + +so if + + align:start position:0% + + + + align:start position:0% + +m is + + align:start position:0% +m is + + + align:start position:0% +m is +and one last assumption and I take + + align:start position:0% +and one last assumption and I take + + + align:start position:0% +and one last assumption and I take +something that's not in the linear + + align:start position:0% +something that's not in the linear + + + align:start position:0% +something that's not in the linear +Subspace + + align:start position:0% + + + + align:start position:0% + +then I can extend it to uh the Subspace + + align:start position:0% +then I can extend it to uh the Subspace + + + align:start position:0% +then I can extend it to uh the Subspace +of V consisting of M and also the + + align:start position:0% +of V consisting of M and also the + + + align:start position:0% +of V consisting of M and also the +Direction X so then + + align:start position:0% +Direction X so then + + + align:start position:0% +Direction X so then +um + + align:start position:0% + + + + align:start position:0% + +there exists U Prime + + align:start position:0% +there exists U Prime + + + align:start position:0% +there exists U Prime +and + + align:start position:0% +and + + + align:start position:0% +and +uh + + align:start position:0% +uh + + + align:start position:0% +uh +so + + align:start position:0% +so + + + align:start position:0% +so +and the dull so I shouldn't use U Prime + + align:start position:0% +and the dull so I shouldn't use U Prime + + + align:start position:0% +and the dull so I shouldn't use U Prime +let's say V + + align:start position:0% + + + + align:start position:0% + +okay well let's use U Prime + + align:start position:0% +okay well let's use U Prime + + + align:start position:0% +okay well let's use U Prime +U Prime + + align:start position:0% + + + + align:start position:0% + +from + + align:start position:0% +from + + + align:start position:0% +from +M Prime to C + + align:start position:0% + + + + align:start position:0% + +which is + + align:start position:0% +which is + + + align:start position:0% +which is +linear and here M Prime + + align:start position:0% + + + + align:start position:0% + +is defined to be the subset or the + + align:start position:0% +is defined to be the subset or the + + + align:start position:0% +is defined to be the subset or the +Subspace M plus so this should be this + + align:start position:0% +Subspace M plus so this should be this + + + align:start position:0% +Subspace M plus so this should be this +does not mean + + align:start position:0% +does not mean + + + align:start position:0% +does not mean +um + + align:start position:0% +um + + + align:start position:0% +um +you know quotient space we were using + + align:start position:0% +you know quotient space we were using + + + align:start position:0% +you know quotient space we were using +pluses for for quotient spaces but this + + align:start position:0% +pluses for for quotient spaces but this + + + align:start position:0% +pluses for for quotient spaces but this +is the Subspace of V consisting of M + + align:start position:0% +is the Subspace of V consisting of M + + + align:start position:0% +is the Subspace of V consisting of M +plus elements of the form + + align:start position:0% +plus elements of the form + + + align:start position:0% +plus elements of the form +uh + + align:start position:0% +uh + + + align:start position:0% +uh +constant times x so this is + + align:start position:0% + + + + align:start position:0% + +elements of the form t plus + + align:start position:0% +elements of the form t plus + + + align:start position:0% +elements of the form t plus +a x where + + align:start position:0% +a x where + + + align:start position:0% +a x where +T is in m + + align:start position:0% +T is in m + + + align:start position:0% +T is in m +a is in C + + align:start position:0% + + + + align:start position:0% + +such that + + align:start position:0% + + + + align:start position:0% + +U Prime when we're stick restricted to M + + align:start position:0% +U Prime when we're stick restricted to M + + + align:start position:0% +U Prime when we're stick restricted to M +gives me U + + align:start position:0% +gives me U + + + align:start position:0% +gives me U +and + + align:start position:0% +and + + + align:start position:0% +and +for all T Prime and M Prime + + align:start position:0% +for all T Prime and M Prime + + + align:start position:0% +for all T Prime and M Prime +uh + + align:start position:0% +uh + + + align:start position:0% +uh +U Prime of T Prime absolute value is + + align:start position:0% +U Prime of T Prime absolute value is + + + align:start position:0% +U Prime of T Prime absolute value is +less than or equal to the same constant + + align:start position:0% + + + + align:start position:0% + +times the norm of T Prime Okay so + + align:start position:0% +times the norm of T Prime Okay so + + + align:start position:0% +times the norm of T Prime Okay so +maybe I made a mess of that uh speaking + + align:start position:0% +maybe I made a mess of that uh speaking + + + align:start position:0% +maybe I made a mess of that uh speaking +while I was riding the limo but anyways + + align:start position:0% +while I was riding the limo but anyways + + + align:start position:0% +while I was riding the limo but anyways +so let's say you have a bounded linear + + align:start position:0% +so let's say you have a bounded linear + + + align:start position:0% +so let's say you have a bounded linear +functional on a Subspace of V and you + + align:start position:0% +functional on a Subspace of V and you + + + align:start position:0% +functional on a Subspace of V and you +take an element that's not an m + + align:start position:0% +take an element that's not an m + + + align:start position:0% +take an element that's not an m +so the way I'll draw the picture is + + align:start position:0% +so the way I'll draw the picture is + + + align:start position:0% +so the way I'll draw the picture is +there's m + + align:start position:0% +there's m + + + align:start position:0% +there's m +and here's something + + align:start position:0% +and here's something + + + align:start position:0% +and here's something +so + + align:start position:0% +so + + + align:start position:0% +so +X then + + align:start position:0% +X then + + + align:start position:0% +X then +I can extend this + + align:start position:0% +I can extend this + + + align:start position:0% +I can extend this +bounded linear functional which lives on + + align:start position:0% +bounded linear functional which lives on + + + align:start position:0% +bounded linear functional which lives on +M to now + + align:start position:0% +M to now + + + align:start position:0% +M to now +uh + + align:start position:0% +uh + + + align:start position:0% +uh +the Subspace consisting of all elements + + align:start position:0% +the Subspace consisting of all elements + + + align:start position:0% +the Subspace consisting of all elements +of M plus elements uh plus scalar + + align:start position:0% +of M plus elements uh plus scalar + + + align:start position:0% +of M plus elements uh plus scalar +multiple multiples of x + + align:start position:0% +multiple multiples of x + + + align:start position:0% +multiple multiples of x +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and I can do this in a continuous way + + align:start position:0% +and I can do this in a continuous way + + + align:start position:0% +and I can do this in a continuous way +meaning I get a bounded linear + + align:start position:0% +meaning I get a bounded linear + + + align:start position:0% +meaning I get a bounded linear +functional on M Prime which satisfies + + align:start position:0% +functional on M Prime which satisfies + + + align:start position:0% +functional on M Prime which satisfies +the same bound as you did okay + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +all right so what's the strategy for + + align:start position:0% +all right so what's the strategy for + + + align:start position:0% +all right so what's the strategy for +using this to prove uh the hunbonic + + align:start position:0% +using this to prove uh the hunbonic + + + align:start position:0% +using this to prove uh the hunbonic +theorem so + + align:start position:0% +theorem so + + + align:start position:0% +theorem so +just so that we're clear on + + align:start position:0% +just so that we're clear on + + + align:start position:0% +just so that we're clear on +why we would be interested in such a + + align:start position:0% +why we would be interested in such a + + + align:start position:0% +why we would be interested in such a +such a thing + + align:start position:0% +such a thing + + + align:start position:0% +such a thing +um + + align:start position:0% +um + + + align:start position:0% +um +so + + align:start position:0% + + + + align:start position:0% + +we apply Zorn's Lima to all + + align:start position:0% + + + + align:start position:0% + +continuous extensions of little use so + + align:start position:0% +continuous extensions of little use so + + + align:start position:0% +continuous extensions of little use so +now I'm talking about how we prove Han + + align:start position:0% +now I'm talking about how we prove Han + + + align:start position:0% +now I'm talking about how we prove Han +Bonnet theorem okay + + align:start position:0% +Bonnet theorem okay + + + align:start position:0% +Bonnet theorem okay +so we Define as our linearly or as our + + align:start position:0% +so we Define as our linearly or as our + + + align:start position:0% +so we Define as our linearly or as our +partially ordered set would be the set + + align:start position:0% +partially ordered set would be the set + + + align:start position:0% +partially ordered set would be the set +of all continuous extensions of U and + + align:start position:0% +of all continuous extensions of U and + + + align:start position:0% +of all continuous extensions of U and +then we would put a partial order on + + align:start position:0% +then we would put a partial order on + + + align:start position:0% +then we would put a partial order on +that where + + align:start position:0% +that where + + + align:start position:0% +that where +one extension is bigger than or equal to + + align:start position:0% +one extension is bigger than or equal to + + + align:start position:0% +one extension is bigger than or equal to +another extension if that extension + + align:start position:0% +another extension if that extension + + + align:start position:0% +another extension if that extension +extends the smaller extension okay + + align:start position:0% +extends the smaller extension okay + + + align:start position:0% +extends the smaller extension okay +and using kind of the argument we did + + align:start position:0% +and using kind of the argument we did + + + align:start position:0% +and using kind of the argument we did +for uh proving the vector space has a + + align:start position:0% +for uh proving the vector space has a + + + align:start position:0% +for uh proving the vector space has a +Hamel basis we can then show that Zorn's + + align:start position:0% +Hamel basis we can then show that Zorn's + + + align:start position:0% +Hamel basis we can then show that Zorn's +Lemma applies okay and then we'll have a + + align:start position:0% +Lemma applies okay and then we'll have a + + + align:start position:0% +Lemma applies okay and then we'll have a +maximal element of this set of + + align:start position:0% +maximal element of this set of + + + align:start position:0% +maximal element of this set of +continuous extensions + + align:start position:0% +continuous extensions + + + align:start position:0% +continuous extensions +um + + align:start position:0% +um + + + align:start position:0% +um +of you now what we would like to + + align:start position:0% +of you now what we would like to + + + align:start position:0% +of you now what we would like to +conclude is that this maximal element + + align:start position:0% +conclude is that this maximal element + + + align:start position:0% +conclude is that this maximal element +this maximal continuous extension is + + align:start position:0% +this maximal continuous extension is + + + align:start position:0% +this maximal continuous extension is +defined on all of V + + align:start position:0% +defined on all of V + + + align:start position:0% +defined on all of V +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and + + align:start position:0% +and + + + align:start position:0% +and +so how would we prove uh that well we + + align:start position:0% +so how would we prove uh that well we + + + align:start position:0% +so how would we prove uh that well we +would do it just kind of like we did for + + align:start position:0% +would do it just kind of like we did for + + + align:start position:0% +would do it just kind of like we did for +the Hammel basis case we would suppose + + align:start position:0% +the Hammel basis case we would suppose + + + align:start position:0% +the Hammel basis case we would suppose +not and then we would show that if it + + align:start position:0% +not and then we would show that if it + + + align:start position:0% +not and then we would show that if it +was not defined on the entire Norm space + + align:start position:0% +was not defined on the entire Norm space + + + align:start position:0% +was not defined on the entire Norm space +then we can extend that maximal element + + align:start position:0% +then we can extend that maximal element + + + align:start position:0% +then we can extend that maximal element +again using this Lemma + + align:start position:0% +again using this Lemma + + + align:start position:0% +again using this Lemma +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and therefore contradicting the fact + + align:start position:0% +and therefore contradicting the fact + + + align:start position:0% +and therefore contradicting the fact +that that extension was a maximal + + align:start position:0% +that that extension was a maximal + + + align:start position:0% +that that extension was a maximal +element + + align:start position:0% +element + + + align:start position:0% +element +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so in short we apply Zorn's Lemma to all + + align:start position:0% +so in short we apply Zorn's Lemma to all + + + align:start position:0% +so in short we apply Zorn's Lemma to all +continuous extensions of view uh + + align:start position:0% + + + + align:start position:0% + +to get a maximal element + + align:start position:0% +to get a maximal element + + + align:start position:0% +to get a maximal element +capital u + + align:start position:0% +capital u + + + align:start position:0% +capital u +two + + align:start position:0% +two + + + align:start position:0% +two +we use the Lima + + align:start position:0% + + + + align:start position:0% + +to show you + + align:start position:0% +to show you + + + align:start position:0% +to show you +is + + align:start position:0% +is + + + align:start position:0% +is +this extension is defined on + + align:start position:0% +this extension is defined on + + + align:start position:0% +this extension is defined on +all of capital B so these extensions + + align:start position:0% +all of capital B so these extensions + + + align:start position:0% +all of capital B so these extensions +will come with two pieces of information + + align:start position:0% +will come with two pieces of information + + + align:start position:0% +will come with two pieces of information +uh one is the Subspace which you know is + + align:start position:0% +uh one is the Subspace which you know is + + + align:start position:0% +uh one is the Subspace which you know is +bigger than M and then also the + + align:start position:0% +bigger than M and then also the + + + align:start position:0% +bigger than M and then also the +functional itself and so we'll use the + + align:start position:0% +functional itself and so we'll use the + + + align:start position:0% +functional itself and so we'll use the +limit to show that the Subspace that + + align:start position:0% +limit to show that the Subspace that + + + align:start position:0% +limit to show that the Subspace that +this capital u is defined on is all of V + + align:start position:0% +this capital u is defined on is all of V + + + align:start position:0% +this capital u is defined on is all of V +okay by showing that if it's not then we + + align:start position:0% +okay by showing that if it's not then we + + + align:start position:0% +okay by showing that if it's not then we +can extend it to a slightly bigger + + align:start position:0% +can extend it to a slightly bigger + + + align:start position:0% +can extend it to a slightly bigger +Subspace using the Lemma which would + + align:start position:0% +Subspace using the Lemma which would + + + align:start position:0% +Subspace using the Lemma which would +contradict the fact that this is a + + align:start position:0% +contradict the fact that this is a + + + align:start position:0% +contradict the fact that this is a +maximal element okay so that's that's + + align:start position:0% +maximal element okay so that's that's + + + align:start position:0% +maximal element okay so that's that's +the that's the plan + + align:start position:0% + + + + align:start position:0% + +so uh in fact + + align:start position:0% + + + + align:start position:0% + +you know since we have this limb already + + align:start position:0% +you know since we have this limb already + + + align:start position:0% +you know since we have this limb already +here and since I've said it so many + + align:start position:0% +here and since I've said it so many + + + align:start position:0% +here and since I've said it so many +times let's go ahead and just prove the + + align:start position:0% +times let's go ahead and just prove the + + + align:start position:0% +times let's go ahead and just prove the +hanbanek theorem assuming this Lima + + align:start position:0% +hanbanek theorem assuming this Lima + + + align:start position:0% +hanbanek theorem assuming this Lima +holds okay + + align:start position:0% +holds okay + + + align:start position:0% +holds okay +uh we don't need the proof of this Lima + + align:start position:0% +uh we don't need the proof of this Lima + + + align:start position:0% +uh we don't need the proof of this Lima +to to + + align:start position:0% +to to + + + align:start position:0% +to to +actually prove the harmonic theorem we + + align:start position:0% +actually prove the harmonic theorem we + + + align:start position:0% +actually prove the harmonic theorem we +just need this statement so that's what + + align:start position:0% +just need this statement so that's what + + + align:start position:0% +just need this statement so that's what +we're going to do first and then we'll + + align:start position:0% +we're going to do first and then we'll + + + align:start position:0% +we're going to do first and then we'll +prove go back and prove this Lemma okay + + align:start position:0% + + + + align:start position:0% + +so this is the proof of the Han banek + + align:start position:0% +so this is the proof of the Han banek + + + align:start position:0% +so this is the proof of the Han banek +theorem we'll go back and prove the limb + + align:start position:0% +theorem we'll go back and prove the limb + + + align:start position:0% +theorem we'll go back and prove the limb +in a second + + align:start position:0% +in a second + + + align:start position:0% +in a second +so + + align:start position:0% + + + + align:start position:0% + +let e like I said this will be the set + + align:start position:0% +let e like I said this will be the set + + + align:start position:0% +let e like I said this will be the set +of all continuous extensions of little U + + align:start position:0% +of all continuous extensions of little U + + + align:start position:0% +of all continuous extensions of little U +so V comma uh + + align:start position:0% +so V comma uh + + + align:start position:0% +so V comma uh +say n + + align:start position:0% +say n + + + align:start position:0% +say n +such that + + align:start position:0% +such that + + + align:start position:0% +such that +uh + + align:start position:0% +uh + + + align:start position:0% +uh +n is + + align:start position:0% + + + + align:start position:0% + +a Subspace of V + + align:start position:0% +a Subspace of V + + + align:start position:0% +a Subspace of V +m is contained in N not strictly but + + align:start position:0% +m is contained in N not strictly but + + + align:start position:0% +m is contained in N not strictly but +it's a subset of n + + align:start position:0% + + + + align:start position:0% + +and V is a + + align:start position:0% + + + + align:start position:0% + +continuous extension + + align:start position:0% + + + + align:start position:0% + +of U + + align:start position:0% +of U + + + align:start position:0% +of U +to capital N okay meaning it satisfies + + align:start position:0% +to capital N okay meaning it satisfies + + + align:start position:0% +to capital N okay meaning it satisfies +you know it's a bounded linear + + align:start position:0% +you know it's a bounded linear + + + align:start position:0% +you know it's a bounded linear +functional and Cat on capital N + + align:start position:0% +functional and Cat on capital N + + + align:start position:0% +functional and Cat on capital N +when you restrict it to capital M it + + align:start position:0% +when you restrict it to capital M it + + + align:start position:0% +when you restrict it to capital M it +equals U and it satisfies the same bound + + align:start position:0% +equals U and it satisfies the same bound + + + align:start position:0% +equals U and it satisfies the same bound +that little U does on the uh + + align:start position:0% +that little U does on the uh + + + align:start position:0% +that little U does on the uh +sub Vigor Subspace in okay + + align:start position:0% + + + + align:start position:0% + +and note this is non + + align:start position:0% +and note this is non + + + align:start position:0% +and note this is non +empty because well U and M are in this + + align:start position:0% +empty because well U and M are in this + + + align:start position:0% +empty because well U and M are in this +okay I'm not saying M has to be a strict + + align:start position:0% +okay I'm not saying M has to be a strict + + + align:start position:0% +okay I'm not saying M has to be a strict +Subspace of capital n + + align:start position:0% + + + + align:start position:0% + +and so we'll Define a partial order on E + + align:start position:0% + + + + align:start position:0% + +by the following definition + + align:start position:0% + + + + align:start position:0% + +we will say V1 N1 + + align:start position:0% +we will say V1 N1 + + + align:start position:0% +we will say V1 N1 +is less than or equal to V2 + + align:start position:0% +is less than or equal to V2 + + + align:start position:0% +is less than or equal to V2 +into + + align:start position:0% + + + + align:start position:0% + +if + + align:start position:0% +if + + + align:start position:0% +if +N1 is contained in N2 + + align:start position:0% +N1 is contained in N2 + + + align:start position:0% +N1 is contained in N2 +and V2 + + align:start position:0% +and V2 + + + align:start position:0% +and V2 +uh when restricted to N1 gives me V1 + + align:start position:0% +uh when restricted to N1 gives me V1 + + + align:start position:0% +uh when restricted to N1 gives me V1 +okay so + + align:start position:0% +okay so + + + align:start position:0% +okay so +V2 is if you'd like a continuous + + align:start position:0% +V2 is if you'd like a continuous + + + align:start position:0% +V2 is if you'd like a continuous +extension of V1 + + align:start position:0% +extension of V1 + + + align:start position:0% +extension of V1 +okay + + align:start position:0% +okay + + + align:start position:0% +okay +remember all of these functionals are + + align:start position:0% +remember all of these functionals are + + + align:start position:0% +remember all of these functionals are +set assumed to be satisfying the same + + align:start position:0% +set assumed to be satisfying the same + + + align:start position:0% +set assumed to be satisfying the same +bound as you did okay so with the same + + align:start position:0% +bound as you did okay so with the same + + + align:start position:0% +bound as you did okay so with the same +constant + + align:start position:0% + + + + align:start position:0% + +so it's not difficult to check just like + + align:start position:0% +so it's not difficult to check just like + + + align:start position:0% +so it's not difficult to check just like +you know I didn't check it for for uh + + align:start position:0% +you know I didn't check it for for uh + + + align:start position:0% +you know I didn't check it for for uh +inclusion but it's not hard to to check + + align:start position:0% +inclusion but it's not hard to to check + + + align:start position:0% +inclusion but it's not hard to to check +that + + align:start position:0% +that + + + align:start position:0% +that +um + + align:start position:0% + + + + align:start position:0% + +that this is in fact + + align:start position:0% +that this is in fact + + + align:start position:0% +that this is in fact +is a partial order + + align:start position:0% + + + + align:start position:0% + +so now we want to apply Zorn's Lemma to + + align:start position:0% +so now we want to apply Zorn's Lemma to + + + align:start position:0% +so now we want to apply Zorn's Lemma to +get a maximal element of e which we want + + align:start position:0% +get a maximal element of e which we want + + + align:start position:0% +get a maximal element of e which we want +to show is in fact uh + + align:start position:0% +to show is in fact uh + + + align:start position:0% +to show is in fact uh +uh this uh that we say exists + + align:start position:0% +uh this uh that we say exists + + + align:start position:0% +uh this uh that we say exists +so we have to show every chain in E has + + align:start position:0% +so we have to show every chain in E has + + + align:start position:0% +so we have to show every chain in E has +an upper bound so let's see + + align:start position:0% + + + + align:start position:0% + +which I'll + + align:start position:0% +which I'll + + + align:start position:0% +which I'll +um + + align:start position:0% +um + + + align:start position:0% +um +to note as + + align:start position:0% +to note as + + + align:start position:0% +to note as +b i + + align:start position:0% +b i + + + align:start position:0% +b i +n i for I in some index + + align:start position:0% + + + + align:start position:0% + +B + + align:start position:0% + + + + align:start position:0% + +chain and E so this is a set of a set of + + align:start position:0% +chain and E so this is a set of a set of + + + align:start position:0% +chain and E so this is a set of a set of +extensions and we can always compare any + + align:start position:0% +extensions and we can always compare any + + + align:start position:0% +extensions and we can always compare any +two extensions in there + + align:start position:0% +two extensions in there + + + align:start position:0% +two extensions in there +so let me just repeat or write down + + align:start position:0% +so let me just repeat or write down + + + align:start position:0% +so let me just repeat or write down +again what this means to be a chain this + + align:start position:0% +again what this means to be a chain this + + + align:start position:0% +again what this means to be a chain this +means then for all + + align:start position:0% +means then for all + + + align:start position:0% +means then for all +I won + + align:start position:0% +I won + + + align:start position:0% +I won +I2 + + align:start position:0% +I2 + + + align:start position:0% +I2 +in this index that I'm using just to + + align:start position:0% +in this index that I'm using just to + + + align:start position:0% +in this index that I'm using just to +index these elements of the chain + + align:start position:0% + + + + align:start position:0% + +either + + align:start position:0% + + + + align:start position:0% + +bi1 + + align:start position:0% +bi1 + + + align:start position:0% +bi1 +in i1 is less than or equal to + + align:start position:0% +in i1 is less than or equal to + + + align:start position:0% +in i1 is less than or equal to +bi2 + + align:start position:0% +bi2 + + + align:start position:0% +bi2 +in I2 + + align:start position:0% +in I2 + + + align:start position:0% +in I2 +or + + align:start position:0% + + + + align:start position:0% + +vice versa I can't remember if a c goes + + align:start position:0% +vice versa I can't remember if a c goes + + + align:start position:0% +vice versa I can't remember if a c goes +there or an S so I'm going to put an S + + align:start position:0% +there or an S so I'm going to put an S + + + align:start position:0% +there or an S so I'm going to put an S +okay so one is either bigger than + + align:start position:0% +okay so one is either bigger than + + + align:start position:0% +okay so one is either bigger than +whenever I have two elements or I can + + align:start position:0% +whenever I have two elements or I can + + + align:start position:0% +whenever I have two elements or I can +always compare them + + align:start position:0% +always compare them + + + align:start position:0% +always compare them +um + + align:start position:0% +um + + + align:start position:0% +um +okay + + align:start position:0% + + + + align:start position:0% + +let N be + + align:start position:0% +let N be + + + align:start position:0% +let N be +uh the union of all these subspaces + + align:start position:0% +uh the union of all these subspaces + + + align:start position:0% +uh the union of all these subspaces +coming from this collection + + align:start position:0% +coming from this collection + + + align:start position:0% +coming from this collection +okay + + align:start position:0% + + + + align:start position:0% + +now + + align:start position:0% +now + + + align:start position:0% +now +um + + align:start position:0% +um + + + align:start position:0% +um +it's again it's it's not difficult to + + align:start position:0% +it's again it's it's not difficult to + + + align:start position:0% +it's again it's it's not difficult to +show that end is in fact a Subspace so I + + align:start position:0% +show that end is in fact a Subspace so I + + + align:start position:0% +show that end is in fact a Subspace so I +claim + + align:start position:0% + + + + align:start position:0% + +in is a Subspace and again we're going + + align:start position:0% +in is a Subspace and again we're going + + + align:start position:0% +in is a Subspace and again we're going +to use the fact that c is a chain to be + + align:start position:0% +to use the fact that c is a chain to be + + + align:start position:0% +to use the fact that c is a chain to be +able to verify this + + align:start position:0% + + + + align:start position:0% + +let V1 + + align:start position:0% +let V1 + + + align:start position:0% +let V1 +V2 B and N + + align:start position:0% +V2 B and N + + + align:start position:0% +V2 B and N +and + + align:start position:0% +and + + + align:start position:0% +and +uh let's take two scalars A1 + + align:start position:0% +uh let's take two scalars A1 + + + align:start position:0% +uh let's take two scalars A1 +A2 and C + + align:start position:0% +A2 and C + + + align:start position:0% +A2 and C +I want to show that A1 times V1 plus A2 + + align:start position:0% +I want to show that A1 times V1 plus A2 + + + align:start position:0% +I want to show that A1 times V1 plus A2 +times V2 remains an n + + align:start position:0% + + + + align:start position:0% + +then there exists i1 + + align:start position:0% +then there exists i1 + + + align:start position:0% +then there exists i1 +i22 indices such that V1 is in uh + + align:start position:0% +i22 indices such that V1 is in uh + + + align:start position:0% +i22 indices such that V1 is in uh +in i1 + + align:start position:0% + + + + align:start position:0% + +and V2 is in in + + align:start position:0% +and V2 is in in + + + align:start position:0% +and V2 is in in +all right too + + align:start position:0% +all right too + + + align:start position:0% +all right too +now I can always compare + + align:start position:0% +now I can always compare + + + align:start position:0% +now I can always compare +any two uh subspaces + + align:start position:0% +any two uh subspaces + + + align:start position:0% +any two uh subspaces +that are appearing in this + + align:start position:0% +that are appearing in this + + + align:start position:0% +that are appearing in this +you know set of ordered pairs forming + + align:start position:0% +you know set of ordered pairs forming + + + align:start position:0% +you know set of ordered pairs forming +this chain so one of these subspaces is + + align:start position:0% +this chain so one of these subspaces is + + + align:start position:0% +this chain so one of these subspaces is +bigger than the other + + align:start position:0% + + + + align:start position:0% + +then uh just by you know flipping + + align:start position:0% +then uh just by you know flipping + + + align:start position:0% +then uh just by you know flipping +one and two if I need to + + align:start position:0% + + + + align:start position:0% + +and since C is a chain + + align:start position:0% + + + + align:start position:0% + +uh in i1 is contained in ni2 + + align:start position:0% +uh in i1 is contained in ni2 + + + align:start position:0% +uh in i1 is contained in ni2 +without loss of generality so it's you + + align:start position:0% +without loss of generality so it's you + + + align:start position:0% +without loss of generality so it's you +know it will either be in i1 will be + + align:start position:0% +know it will either be in i1 will be + + + align:start position:0% +know it will either be in i1 will be +contained in ni2 or the other way around + + align:start position:0% +contained in ni2 or the other way around + + + align:start position:0% +contained in ni2 or the other way around +and if it's the other way around just + + align:start position:0% +and if it's the other way around just + + + align:start position:0% +and if it's the other way around just +flip the numbers one and two uh so I'm + + align:start position:0% +flip the numbers one and two uh so I'm + + + align:start position:0% +flip the numbers one and two uh so I'm +going to assume ni1 is contained in ni2 + + align:start position:0% +going to assume ni1 is contained in ni2 + + + align:start position:0% +going to assume ni1 is contained in ni2 +then that mean that means both of these + + align:start position:0% +then that mean that means both of these + + + align:start position:0% +then that mean that means both of these +elements are contained in ni2 + + align:start position:0% + + + + align:start position:0% + +and V2 are both in the bigger one and + + align:start position:0% +and V2 are both in the bigger one and + + + align:start position:0% +and V2 are both in the bigger one and +since this is a Subspace this means that + + align:start position:0% +since this is a Subspace this means that + + + align:start position:0% +since this is a Subspace this means that +A1 V1 plus A2 V2 is in in I2 + + align:start position:0% +A1 V1 plus A2 V2 is in in I2 + + + align:start position:0% +A1 V1 plus A2 V2 is in in I2 +which remember is a subset of + + align:start position:0% +which remember is a subset of + + + align:start position:0% +which remember is a subset of +n + + align:start position:0% + + + + align:start position:0% + +and therefore N is a Subspace + + align:start position:0% + + + + align:start position:0% + +so I now have a Subspace which contains + + align:start position:0% +so I now have a Subspace which contains + + + align:start position:0% +so I now have a Subspace which contains +all of these subspaces coming from the + + align:start position:0% +all of these subspaces coming from the + + + align:start position:0% +all of these subspaces coming from the +chain now I need to Define a linear + + align:start position:0% +chain now I need to Define a linear + + + align:start position:0% +chain now I need to Define a linear +functional on this Subspace in that + + align:start position:0% +functional on this Subspace in that + + + align:start position:0% +functional on this Subspace in that +extends all the VIS in a continuous way + + align:start position:0% +extends all the VIS in a continuous way + + + align:start position:0% +extends all the VIS in a continuous way +and therefore and this would give me an + + align:start position:0% +and therefore and this would give me an + + + align:start position:0% +and therefore and this would give me an +upper Bound for this chain but it's not + + align:start position:0% +upper Bound for this chain but it's not + + + align:start position:0% +upper Bound for this chain but it's not +difficult to to + + align:start position:0% +difficult to to + + + align:start position:0% +difficult to to +guess what that linear functional will + + align:start position:0% +guess what that linear functional will + + + align:start position:0% +guess what that linear functional will +be + + align:start position:0% + + + + align:start position:0% + +we Define + + align:start position:0% +we Define + + + align:start position:0% +we Define +V or not I don't think I use V + + align:start position:0% +V or not I don't think I use V + + + align:start position:0% +V or not I don't think I use V +yeah I do well let's not do that + + align:start position:0% +yeah I do well let's not do that + + + align:start position:0% +yeah I do well let's not do that +uh + + align:start position:0% +uh + + + align:start position:0% +uh +let's say + + align:start position:0% + + + + align:start position:0% + +okay so I mean I shouldn't have used V1 + + align:start position:0% +okay so I mean I shouldn't have used V1 + + + align:start position:0% +okay so I mean I shouldn't have used V1 +and V2 when talking about this Subspace + + align:start position:0% +and V2 when talking about this Subspace + + + align:start position:0% +and V2 when talking about this Subspace +uh + + align:start position:0% +uh + + + align:start position:0% +uh +business that was poor choice of of + + align:start position:0% +business that was poor choice of of + + + align:start position:0% +business that was poor choice of of +notation + + align:start position:0% + + + + align:start position:0% + +you know so let's let's make that X1 X2 + + align:start position:0% +you know so let's let's make that X1 X2 + + + align:start position:0% +you know so let's let's make that X1 X2 +and + + align:start position:0% + + + + align:start position:0% + +the chain blah blah blah + + align:start position:0% +the chain blah blah blah + + + align:start position:0% +the chain blah blah blah +X1 X2 and therefore + + align:start position:0% +X1 X2 and therefore + + + align:start position:0% +X1 X2 and therefore +X1 + + align:start position:0% +X1 + + + align:start position:0% +X1 +X2 is ending okay + + align:start position:0% +X2 is ending okay + + + align:start position:0% +X2 is ending okay +so + + align:start position:0% +so + + + align:start position:0% +so +so I just don't want to mix up the + + align:start position:0% +so I just don't want to mix up the + + + align:start position:0% +so I just don't want to mix up the +elements of the vector space with these + + align:start position:0% +elements of the vector space with these + + + align:start position:0% +elements of the vector space with these +functionals which I'm labeling by V + + align:start position:0% +functionals which I'm labeling by V + + + align:start position:0% +functionals which I'm labeling by V +okay so now we Define + + align:start position:0% + + + + align:start position:0% + +a function V from n to C + + align:start position:0% + + + + align:start position:0% + +by the following + + align:start position:0% + + + + align:start position:0% + +so if T is an element of this Union it + + align:start position:0% +so if T is an element of this Union it + + + align:start position:0% +so if T is an element of this Union it +has to be an element of one of these N + + align:start position:0% +has to be an element of one of these N + + + align:start position:0% +has to be an element of one of these N +Sub I's + + align:start position:0% +Sub I's + + + align:start position:0% +Sub I's +then I Define V of T to be simply + + align:start position:0% +then I Define V of T to be simply + + + align:start position:0% +then I Define V of T to be simply +V of t v sub I which is defined on this + + align:start position:0% +V of t v sub I which is defined on this + + + align:start position:0% +V of t v sub I which is defined on this +linear Subspace + + align:start position:0% + + + + align:start position:0% + +and so I take V of T to be the value of + + align:start position:0% +and so I take V of T to be the value of + + + align:start position:0% +and so I take V of T to be the value of +B sub I evaluated at T so now one + + align:start position:0% +B sub I evaluated at T so now one + + + align:start position:0% +B sub I evaluated at T so now one +question is is this well defined right + + align:start position:0% +question is is this well defined right + + + align:start position:0% +question is is this well defined right +because an element T in N Sub I + + align:start position:0% +because an element T in N Sub I + + + align:start position:0% +because an element T in N Sub I +could also have been an element of a + + align:start position:0% +could also have been an element of a + + + align:start position:0% +could also have been an element of a +different N Sub I + + align:start position:0% + + + + align:start position:0% + +so is this well defined so we have to + + align:start position:0% +so is this well defined so we have to + + + align:start position:0% +so is this well defined so we have to +check + + align:start position:0% + + + + align:start position:0% + +if it's in two of these + + align:start position:0% + + + + align:start position:0% + +does this imply question mark + + align:start position:0% +does this imply question mark + + + align:start position:0% +does this imply question mark +vi1 of T equals v i 2 of t + + align:start position:0% +vi1 of T equals v i 2 of t + + + align:start position:0% +vi1 of T equals v i 2 of t +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and again we're going to use the fact + + align:start position:0% +and again we're going to use the fact + + + align:start position:0% +and again we're going to use the fact +that this is a chain to verify this + + align:start position:0% +that this is a chain to verify this + + + align:start position:0% +that this is a chain to verify this +so suppose + + align:start position:0% +so suppose + + + align:start position:0% +so suppose +T is In N Sub i1 + + align:start position:0% + + + + align:start position:0% + +intersect N Sub I2 + + align:start position:0% +intersect N Sub I2 + + + align:start position:0% +intersect N Sub I2 +and uh + + align:start position:0% +and uh + + + align:start position:0% +and uh +you know again for any two elements of + + align:start position:0% +you know again for any two elements of + + + align:start position:0% +you know again for any two elements of +this chain we can compare them so let's + + align:start position:0% +this chain we can compare them so let's + + + align:start position:0% +this chain we can compare them so let's +assume I2 corresponds to the bigger + + align:start position:0% +assume I2 corresponds to the bigger + + + align:start position:0% +assume I2 corresponds to the bigger +index so + + align:start position:0% +index so + + + align:start position:0% +index so +vi1 in i1 is less than or equal to + + align:start position:0% +vi1 in i1 is less than or equal to + + + align:start position:0% +vi1 in i1 is less than or equal to +the I2 + + align:start position:0% +the I2 + + + align:start position:0% +the I2 +and I2 + + align:start position:0% +and I2 + + + align:start position:0% +and I2 +okay + + align:start position:0% + + + + align:start position:0% + +now + + align:start position:0% +now + + + align:start position:0% +now +this order not only is defined in terms + + align:start position:0% +this order not only is defined in terms + + + align:start position:0% +this order not only is defined in terms +of the subspaces remember but in terms + + align:start position:0% +of the subspaces remember but in terms + + + align:start position:0% +of the subspaces remember but in terms +of the functionals defined on these + + align:start position:0% +of the functionals defined on these + + + align:start position:0% +of the functionals defined on these +subspaces and it's defined by the fact + + align:start position:0% +subspaces and it's defined by the fact + + + align:start position:0% +subspaces and it's defined by the fact +that this functional is an extension of + + align:start position:0% +that this functional is an extension of + + + align:start position:0% +that this functional is an extension of +this functional and therefore + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% + + + + align:start position:0% + +since vi2 is the bigger one it extends + + align:start position:0% + + + + align:start position:0% + +smaller one + + align:start position:0% +smaller one + + + align:start position:0% +smaller one +this implies V I2 of T equals v i 1 of t + + align:start position:0% +this implies V I2 of T equals v i 1 of t + + + align:start position:0% +this implies V I2 of T equals v i 1 of t +and therefore uh + + align:start position:0% + + + + align:start position:0% + +B is + + align:start position:0% + + + + align:start position:0% + +well defined + + align:start position:0% +well defined + + + align:start position:0% +well defined +and not only that it's it's uh you know + + align:start position:0% +and not only that it's it's uh you know + + + align:start position:0% +and not only that it's it's uh you know +you can also so I wrote this out + + align:start position:0% +you can also so I wrote this out + + + align:start position:0% +you can also so I wrote this out +carefully + + align:start position:0% +carefully + + + align:start position:0% +carefully +um + + align:start position:0% +um + + + align:start position:0% +um +showing it's well defined but by a + + align:start position:0% +showing it's well defined but by a + + + align:start position:0% +showing it's well defined but by a +similar arguments you can then show that + + align:start position:0% +similar arguments you can then show that + + + align:start position:0% +similar arguments you can then show that +V is in fact linear and + + align:start position:0% +V is in fact linear and + + + align:start position:0% +V is in fact linear and +see do I do that or do I stop there + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so + + align:start position:0% +so + + + align:start position:0% +so +um + + align:start position:0% +um + + + align:start position:0% +um +it's well defined on N it's also an + + align:start position:0% +it's well defined on N it's also an + + + align:start position:0% +it's well defined on N it's also an +extension of every single functional + + align:start position:0% +extension of every single functional + + + align:start position:0% +extension of every single functional +defined on each N Sub I so the last + + align:start position:0% +defined on each N Sub I so the last + + + align:start position:0% +defined on each N Sub I so the last +thing to check is that it's linear and + + align:start position:0% +thing to check is that it's linear and + + + align:start position:0% +thing to check is that it's linear and +it's a continuous extension of all these + + align:start position:0% +it's a continuous extension of all these + + + align:start position:0% +it's a continuous extension of all these +VI's meaning it satisfies the same bound + + align:start position:0% +VI's meaning it satisfies the same bound + + + align:start position:0% +VI's meaning it satisfies the same bound +but all of the VI's satisfy that bound V + + align:start position:0% +but all of the VI's satisfy that bound V + + + align:start position:0% +but all of the VI's satisfy that bound V +is defined in terms of the V I's + + align:start position:0% +is defined in terms of the V I's + + + align:start position:0% +is defined in terms of the V I's +so I mean we can just read off from here + + align:start position:0% +so I mean we can just read off from here + + + align:start position:0% +so I mean we can just read off from here +that V will satisfy that same bound + + align:start position:0% + + + + align:start position:0% + +then + + align:start position:0% + + + + align:start position:0% + +so I will leave it to you that you can + + align:start position:0% +so I will leave it to you that you can + + + align:start position:0% +so I will leave it to you that you can +check + + align:start position:0% +check + + + align:start position:0% +check +that + + align:start position:0% +that + + + align:start position:0% +that +um + + align:start position:0% +um + + + align:start position:0% +um +V is an element of + + align:start position:0% +V is an element of + + + align:start position:0% +V is an element of +the Dual space of this Subspace in so + + align:start position:0% +the Dual space of this Subspace in so + + + align:start position:0% +the Dual space of this Subspace in so +it's a bounded linear functional on n + + align:start position:0% +it's a bounded linear functional on n + + + align:start position:0% +it's a bounded linear functional on n +and + + align:start position:0% +and + + + align:start position:0% +and +a continuous + + align:start position:0% +a continuous + + + align:start position:0% +a continuous +extension + + align:start position:0% +extension + + + align:start position:0% +extension +of all + + align:start position:0% +of all + + + align:start position:0% +of all +VIs + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +ual okay + + align:start position:0% +ual okay + + + align:start position:0% +ual okay +um + + align:start position:0% +um + + + align:start position:0% +um +so + + align:start position:0% + + + + align:start position:0% + +for all eye and little for little I and + + align:start position:0% +for all eye and little for little I and + + + align:start position:0% +for all eye and little for little I and +capital I we conclude b i + + align:start position:0% +capital I we conclude b i + + + align:start position:0% +capital I we conclude b i +n i is less than or equal to V in + + align:start position:0% +n i is less than or equal to V in + + + align:start position:0% +n i is less than or equal to V in +and therefore + + align:start position:0% +and therefore + + + align:start position:0% +and therefore +v n is an upper bound of C + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +um + + align:start position:0% +um + + + align:start position:0% +um +all right so we've verified the + + align:start position:0% +all right so we've verified the + + + align:start position:0% +all right so we've verified the +hypotheses of Zorn's Lima which I've + + align:start position:0% +hypotheses of Zorn's Lima which I've + + + align:start position:0% +hypotheses of Zorn's Lima which I've +already which I just erased so that + + align:start position:0% +already which I just erased so that + + + align:start position:0% +already which I just erased so that +means the set e has a maximal element + + align:start position:0% +means the set e has a maximal element + + + align:start position:0% +means the set e has a maximal element +so by Zorn's + + align:start position:0% + + + + align:start position:0% + +by Zorn + + align:start position:0% +by Zorn + + + align:start position:0% +by Zorn +uh the set e + + align:start position:0% +uh the set e + + + align:start position:0% +uh the set e +has + + align:start position:0% + + + + align:start position:0% + +a maximal + + align:start position:0% +a maximal + + + align:start position:0% +a maximal +element capital u + + align:start position:0% + + + + align:start position:0% + +n + + align:start position:0% +n + + + align:start position:0% +n +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so I claim in + + align:start position:0% + + + + align:start position:0% + +equals V and therefore capital u does + + align:start position:0% +equals V and therefore capital u does + + + align:start position:0% +equals V and therefore capital u does +the job because remember U Capital uh + + align:start position:0% + + + + align:start position:0% + +so since capital u capital N is an + + align:start position:0% +so since capital u capital N is an + + + align:start position:0% +so since capital u capital N is an +element of e that means capital u is a + + align:start position:0% +element of e that means capital u is a + + + align:start position:0% +element of e that means capital u is a +continuous extension of little U all + + align:start position:0% +continuous extension of little U all + + + align:start position:0% +continuous extension of little U all +right + + align:start position:0% +right + + + align:start position:0% +right +and now we just want to conclude that + + align:start position:0% +and now we just want to conclude that + + + align:start position:0% +and now we just want to conclude that +for this maximal element the Subspace on + + align:start position:0% +for this maximal element the Subspace on + + + align:start position:0% +for this maximal element the Subspace on +which it's defined is the entire space V + + align:start position:0% +which it's defined is the entire space V + + + align:start position:0% +which it's defined is the entire space V +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so + + align:start position:0% +so + + + align:start position:0% +so +suppose not + + align:start position:0% + + + + align:start position:0% + +let X + + align:start position:0% +let X + + + align:start position:0% +let X +be an element not an n + + align:start position:0% + + + + align:start position:0% + +by + + align:start position:0% +by + + + align:start position:0% +by +the Lemma + + align:start position:0% +the Lemma + + + align:start position:0% +the Lemma +um + + align:start position:0% + + + + align:start position:0% + +there exists a + + align:start position:0% + + + + align:start position:0% + +continuous + + align:start position:0% +continuous + + + align:start position:0% +continuous +extension + + align:start position:0% +extension + + + align:start position:0% +extension +of U capital u + + align:start position:0% +of U capital u + + + align:start position:0% +of U capital u +to the Subspace + + align:start position:0% +to the Subspace + + + align:start position:0% +to the Subspace +in Plus + + align:start position:0% + + + + align:start position:0% + +the span of x + + align:start position:0% + + + + align:start position:0% + +and this is a continuous extension of + + align:start position:0% +and this is a continuous extension of + + + align:start position:0% +and this is a continuous extension of +capital u which is a continuous + + align:start position:0% +capital u which is a continuous + + + align:start position:0% +capital u which is a continuous +extension of little U and therefore it's + + align:start position:0% +extension of little U and therefore it's + + + align:start position:0% +extension of little U and therefore it's +a continuous extension of little U + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% + + + + align:start position:0% + +continuous extension let's call this + + align:start position:0% +continuous extension let's call this + + + align:start position:0% +continuous extension let's call this +something let's call it V Little V + + align:start position:0% + + + + align:start position:0% + +n Plus + + align:start position:0% + + + + align:start position:0% + +so uh if the Subspace that capital u is + + align:start position:0% +so uh if the Subspace that capital u is + + + align:start position:0% +so uh if the Subspace that capital u is +defined on is not all of V then by the + + align:start position:0% +defined on is not all of V then by the + + + align:start position:0% +defined on is not all of V then by the +Lima we can extend capital u + + align:start position:0% +Lima we can extend capital u + + + align:start position:0% +Lima we can extend capital u +continuously to n plus uh the span of x + + align:start position:0% +continuously to n plus uh the span of x + + + align:start position:0% +continuously to n plus uh the span of x +and therefore this element will be a + + align:start position:0% +and therefore this element will be a + + + align:start position:0% +and therefore this element will be a +continuous extension of little U + + align:start position:0% +continuous extension of little U + + + align:start position:0% +continuous extension of little U +and therefore it's an element of E + + align:start position:0% + + + + align:start position:0% + +but then + + align:start position:0% +but then + + + align:start position:0% +but then +u n is smaller than + + align:start position:0% +u n is smaller than + + + align:start position:0% +u n is smaller than +B + + align:start position:0% +B + + + align:start position:0% +B +n Plus + + align:start position:0% + + + + align:start position:0% + +uh + + align:start position:0% +uh + + + align:start position:0% +uh +this span of x + + align:start position:0% +this span of x + + + align:start position:0% +this span of x +right this is a bigger Subspace than + + align:start position:0% +right this is a bigger Subspace than + + + align:start position:0% +right this is a bigger Subspace than +this + + align:start position:0% +this + + + align:start position:0% +this +because X is not an n + + align:start position:0% + + + + align:start position:0% + +which implies + + align:start position:0% +which implies + + + align:start position:0% +which implies +u n is + + align:start position:0% + + + + align:start position:0% + +not a maximal element and that's a + + align:start position:0% +not a maximal element and that's a + + + align:start position:0% +not a maximal element and that's a +contradiction and what do we contradict + + align:start position:0% +contradiction and what do we contradict + + + align:start position:0% +contradiction and what do we contradict +uh are what was the assumption that led + + align:start position:0% +uh are what was the assumption that led + + + align:start position:0% +uh are what was the assumption that led +us astray is the fact that uh we assume + + align:start position:0% +us astray is the fact that uh we assume + + + align:start position:0% +us astray is the fact that uh we assume +that this maximal element is not defined + + align:start position:0% +that this maximal element is not defined + + + align:start position:0% +that this maximal element is not defined +on uh all of the entire Norm space + + align:start position:0% + + + + align:start position:0% + +thus + + align:start position:0% +thus + + + align:start position:0% +thus +um + + align:start position:0% +um + + + align:start position:0% +um +you + + align:start position:0% +you + + + align:start position:0% +you +is defined + + align:start position:0% + + + + align:start position:0% + +on the entire Norm space and it's a + + align:start position:0% +on the entire Norm space and it's a + + + align:start position:0% +on the entire Norm space and it's a +continuous + + align:start position:0% + + + + align:start position:0% + +of little you + + align:start position:0% +of little you + + + align:start position:0% +of little you +and that's the proof of hanbana + + align:start position:0% +and that's the proof of hanbana + + + align:start position:0% +and that's the proof of hanbana +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so I hope that the proof uh was you know + + align:start position:0% +so I hope that the proof uh was you know + + + align:start position:0% +so I hope that the proof uh was you know +clear + + align:start position:0% +clear + + + align:start position:0% +clear +if you followed the Hammel basis + + align:start position:0% +if you followed the Hammel basis + + + align:start position:0% +if you followed the Hammel basis +argument this should be + + align:start position:0% +argument this should be + + + align:start position:0% +argument this should be +um + + align:start position:0% +um + + + align:start position:0% +um +you know + + align:start position:0% + + + + align:start position:0% + +reasonable to expect too it's just you + + align:start position:0% +reasonable to expect too it's just you + + + align:start position:0% +reasonable to expect too it's just you +know this argument is almost the same as + + align:start position:0% +know this argument is almost the same as + + + align:start position:0% +know this argument is almost the same as +the Hamilton basis argument except now + + align:start position:0% +the Hamilton basis argument except now + + + align:start position:0% +the Hamilton basis argument except now +you know instead of the handle basis + + align:start position:0% +you know instead of the handle basis + + + align:start position:0% +you know instead of the handle basis +where the elements of our partially + + align:start position:0% +where the elements of our partially + + + align:start position:0% +where the elements of our partially +ordered set are just subsets we also + + align:start position:0% +ordered set are just subsets we also + + + align:start position:0% +ordered set are just subsets we also +have two pieces of data for our + + align:start position:0% +have two pieces of data for our + + + align:start position:0% +have two pieces of data for our +partially ordered set here one being the + + align:start position:0% +partially ordered set here one being the + + + align:start position:0% +partially ordered set here one being the +Subspace and the second being the + + align:start position:0% +Subspace and the second being the + + + align:start position:0% +Subspace and the second being the +functional that's defined on that + + align:start position:0% +functional that's defined on that + + + align:start position:0% +functional that's defined on that +Subspace that extends the original uh + + align:start position:0% +Subspace that extends the original uh + + + align:start position:0% +Subspace that extends the original uh +continuous linear functional that we + + align:start position:0% +continuous linear functional that we + + + align:start position:0% +continuous linear functional that we +wanted to to extend okay + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +um so let's + + align:start position:0% +um so let's + + + align:start position:0% +um so let's +let's prove dilemma and that'll conclude + + align:start position:0% +let's prove dilemma and that'll conclude + + + align:start position:0% +let's prove dilemma and that'll conclude +the proof of the harmonic theorem + + align:start position:0% +the proof of the harmonic theorem + + + align:start position:0% +the proof of the harmonic theorem +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so now we're going to + + align:start position:0% + + + + align:start position:0% + +proof of dilemma + + align:start position:0% + + + + align:start position:0% + +so that limb up there if V is the norm + + align:start position:0% +so that limb up there if V is the norm + + + align:start position:0% +so that limb up there if V is the norm +space and and uh + + align:start position:0% +space and and uh + + + align:start position:0% +space and and uh +you take something that's not in uh + + align:start position:0% +you take something that's not in uh + + + align:start position:0% +you take something that's not in uh +the Subspace and you can extend you + + align:start position:0% +the Subspace and you can extend you + + + align:start position:0% +the Subspace and you can extend you +continuously to this bigger + + align:start position:0% +continuously to this bigger + + + align:start position:0% +continuously to this bigger +Subspace all right + + align:start position:0% + + + + align:start position:0% + +so first off + + align:start position:0% +so first off + + + align:start position:0% +so first off +you know even though I keep saying that + + align:start position:0% +you know even though I keep saying that + + + align:start position:0% +you know even though I keep saying that +this is a Subspace I mean this is kind + + align:start position:0% +this is a Subspace I mean this is kind + + + align:start position:0% +this is a Subspace I mean this is kind +of something that needs to be I mean + + align:start position:0% +of something that needs to be I mean + + + align:start position:0% +of something that needs to be I mean +it's not difficult to check but still + + align:start position:0% +it's not difficult to check but still + + + align:start position:0% +it's not difficult to check but still +check but also so one thing we need is + + align:start position:0% +check but also so one thing we need is + + + align:start position:0% +check but also so one thing we need is +that every element in uh you know a + + align:start position:0% +that every element in uh you know a + + + align:start position:0% +that every element in uh you know a +Subspace plus + + align:start position:0% +Subspace plus + + + align:start position:0% +Subspace plus +um + + align:start position:0% +um + + + align:start position:0% +um +this constant times x can be written + + align:start position:0% +this constant times x can be written + + + align:start position:0% +this constant times x can be written +uniquely so we first note + + align:start position:0% + + + + align:start position:0% + +if T Prime + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +equals t + + align:start position:0% +equals t + + + align:start position:0% +equals t +so T Prime is in M Prime which remember + + align:start position:0% +so T Prime is in M Prime which remember + + + align:start position:0% +so T Prime is in M Prime which remember +is M plus + + align:start position:0% +is M plus + + + align:start position:0% +is M plus +constant times x + + align:start position:0% + + + + align:start position:0% + +then + + align:start position:0% +then + + + align:start position:0% +then +there exists unique T and M + + align:start position:0% +there exists unique T and M + + + align:start position:0% +there exists unique T and M +and a and complex numbers + + align:start position:0% +and a and complex numbers + + + align:start position:0% +and a and complex numbers +such that t Prime equals t plus a times + + align:start position:0% +such that t Prime equals t plus a times + + + align:start position:0% +such that t Prime equals t plus a times +x okay + + align:start position:0% +x okay + + + align:start position:0% +x okay +uh + + align:start position:0% +uh + + + align:start position:0% +uh +all right so why is that + + align:start position:0% +all right so why is that + + + align:start position:0% +all right so why is that +so why can an element of this space not + + align:start position:0% +so why can an element of this space not + + + align:start position:0% +so why can an element of this space not +have two different representations not + + align:start position:0% +have two different representations not + + + align:start position:0% +have two different representations not +be written as you know two different + + align:start position:0% +be written as you know two different + + + align:start position:0% +be written as you know two different +elements of M plus two different scalars + + align:start position:0% +elements of M plus two different scalars + + + align:start position:0% +elements of M plus two different scalars +times x well + + align:start position:0% +times x well + + + align:start position:0% +times x well +if + + align:start position:0% +if + + + align:start position:0% +if +t plus a x equals T tilde plus a tilde X + + align:start position:0% +t plus a x equals T tilde plus a tilde X + + + align:start position:0% +t plus a x equals T tilde plus a tilde X +then this implies that a minus a tilde + + align:start position:0% +then this implies that a minus a tilde + + + align:start position:0% +then this implies that a minus a tilde +times x is equal to + + align:start position:0% + + + + align:start position:0% + +T tilde minus t which is in M okay m is + + align:start position:0% +T tilde minus t which is in M okay m is + + + align:start position:0% +T tilde minus t which is in M okay m is +the Subspace so the difference of two + + align:start position:0% +the Subspace so the difference of two + + + align:start position:0% +the Subspace so the difference of two +elements of uh m is in m + + align:start position:0% + + + + align:start position:0% + +and therefore + + align:start position:0% + + + + align:start position:0% + +if a does not equal a tilde then that + + align:start position:0% +if a does not equal a tilde then that + + + align:start position:0% +if a does not equal a tilde then that +means X is equal to a constant multiple + + align:start position:0% +means X is equal to a constant multiple + + + align:start position:0% +means X is equal to a constant multiple +of something in m and therefore X is an + + align:start position:0% +of something in m and therefore X is an + + + align:start position:0% +of something in m and therefore X is an +m + + align:start position:0% +m + + + align:start position:0% +m +so we conclude that a must equal a tilde + + align:start position:0% +so we conclude that a must equal a tilde + + + align:start position:0% +so we conclude that a must equal a tilde +which implies from assuming they're + + align:start position:0% +which implies from assuming they're + + + align:start position:0% +which implies from assuming they're +equal that t equals T tilde + + align:start position:0% +equal that t equals T tilde + + + align:start position:0% +equal that t equals T tilde +all right so every element in this + + align:start position:0% +all right so every element in this + + + align:start position:0% +all right so every element in this +larger Subspace can be written uniquely + + align:start position:0% +larger Subspace can be written uniquely + + + align:start position:0% +larger Subspace can be written uniquely +as an element of M plus a scalar + + align:start position:0% +as an element of M plus a scalar + + + align:start position:0% +as an element of M plus a scalar +multiple of x + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +now why do we need this fact we need + + align:start position:0% +now why do we need this fact we need + + + align:start position:0% +now why do we need this fact we need +this fact to be able to + + align:start position:0% +this fact to be able to + + + align:start position:0% +this fact to be able to +say that this linear functional that + + align:start position:0% +say that this linear functional that + + + align:start position:0% +say that this linear functional that +we're gonna + + align:start position:0% +we're gonna + + + align:start position:0% +we're gonna +Define that we hope to say extends you + + align:start position:0% +Define that we hope to say extends you + + + align:start position:0% +Define that we hope to say extends you +continuously + + align:start position:0% +continuously + + + align:start position:0% +continuously +um you know it is in fact well defined + + align:start position:0% +um you know it is in fact well defined + + + align:start position:0% +um you know it is in fact well defined +so + + align:start position:0% + + + + align:start position:0% + +thus + + align:start position:0% + + + + align:start position:0% + +upon choosing + + align:start position:0% +upon choosing + + + align:start position:0% +upon choosing +a number Lambda + + align:start position:0% +a number Lambda + + + align:start position:0% +a number Lambda +in the complex numbers + + align:start position:0% + + + + align:start position:0% + +the map + + align:start position:0% + + + + align:start position:0% + +U Prime of + + align:start position:0% +U Prime of + + + align:start position:0% +U Prime of +t plus + + align:start position:0% +t plus + + + align:start position:0% +t plus +ax + + align:start position:0% +ax + + + align:start position:0% +ax +given by U of T Plus + + align:start position:0% +given by U of T Plus + + + align:start position:0% +given by U of T Plus +a Lambda + + align:start position:0% + + + + align:start position:0% + +is + + align:start position:0% +is + + + align:start position:0% +is +well defined + + align:start position:0% + + + + align:start position:0% + +because we've shown every + + align:start position:0% + + + + align:start position:0% + +on M Prime + + align:start position:0% +on M Prime + + + align:start position:0% +on M Prime +because we've shown every element of + + align:start position:0% +because we've shown every element of + + + align:start position:0% +because we've shown every element of +imprime can be written uniquely in this + + align:start position:0% +imprime can be written uniquely in this + + + align:start position:0% +imprime can be written uniquely in this +way + + align:start position:0% +way + + + align:start position:0% +way +is well defined on M Prime + + align:start position:0% + + + + align:start position:0% + +and U Prime going from M Prime to C + + align:start position:0% +and U Prime going from M Prime to C + + + align:start position:0% +and U Prime going from M Prime to C +is linear + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +if the + + align:start position:0% +if the + + + align:start position:0% +if the +original uh functional U little U is if + + align:start position:0% +original uh functional U little U is if + + + align:start position:0% +original uh functional U little U is if +that constant C is equal to zero then + + align:start position:0% +that constant C is equal to zero then + + + align:start position:0% +that constant C is equal to zero then +little U is just identically zero and we + + align:start position:0% +little U is just identically zero and we + + + align:start position:0% +little U is just identically zero and we +know how to extend the zero functional + + align:start position:0% +know how to extend the zero functional + + + align:start position:0% +know how to extend the zero functional +so let's suppose Capital C uh is + + align:start position:0% +so let's suppose Capital C uh is + + + align:start position:0% +so let's suppose Capital C uh is +non-zero + + align:start position:0% +non-zero + + + align:start position:0% +non-zero +and if I divide little U by Capital C I + + align:start position:0% +and if I divide little U by Capital C I + + + align:start position:0% +and if I divide little U by Capital C I +can then extend that functional uh + + align:start position:0% +can then extend that functional uh + + + align:start position:0% +can then extend that functional uh +with the case Capital C equals one and + + align:start position:0% +with the case Capital C equals one and + + + align:start position:0% +with the case Capital C equals one and +obtain an extension satisfying uh the + + align:start position:0% +obtain an extension satisfying uh the + + + align:start position:0% +obtain an extension satisfying uh the +bound I want + + align:start position:0% +bound I want + + + align:start position:0% +bound I want +and + + align:start position:0% +and + + + align:start position:0% +and +uh so what I'm saying + + align:start position:0% +uh so what I'm saying + + + align:start position:0% +uh so what I'm saying +kind of poorly is that + + align:start position:0% + + + + align:start position:0% + +I'll leave you a second to think about + + align:start position:0% +I'll leave you a second to think about + + + align:start position:0% +I'll leave you a second to think about +it it's not + + align:start position:0% +it it's not + + + align:start position:0% +it it's not +difficult to understand why without loss + + align:start position:0% +difficult to understand why without loss + + + align:start position:0% +difficult to understand why without loss +of generality + + align:start position:0% + + + + align:start position:0% + +we can assume + + align:start position:0% +we can assume + + + align:start position:0% +we can assume +C equals one okay + + align:start position:0% +C equals one okay + + + align:start position:0% +C equals one okay +you know if C is not equal to one so if + + align:start position:0% +you know if C is not equal to one so if + + + align:start position:0% +you know if C is not equal to one so if +we do this equals one case then for the + + align:start position:0% +we do this equals one case then for the + + + align:start position:0% +we do this equals one case then for the +KC not equal to one we extend U over + + align:start position:0% +KC not equal to one we extend U over + + + align:start position:0% +KC not equal to one we extend U over +capital c + + align:start position:0% +capital c + + + align:start position:0% +capital c +using the C equals one case and then the + + align:start position:0% +using the C equals one case and then the + + + align:start position:0% +using the C equals one case and then the +result follows so we'll just do the case + + align:start position:0% +result follows so we'll just do the case + + + align:start position:0% +result follows so we'll just do the case +C equals capital or Capital C equals one + + align:start position:0% +C equals capital or Capital C equals one + + + align:start position:0% +C equals capital or Capital C equals one +uh so + + align:start position:0% + + + + align:start position:0% + +now our one free parameter is Lambda + + align:start position:0% +now our one free parameter is Lambda + + + align:start position:0% +now our one free parameter is Lambda +okay + + align:start position:0% + + + + align:start position:0% + +and this is for + + align:start position:0% + + + + align:start position:0% + +and we want to be able to choose Lambda + + align:start position:0% +and we want to be able to choose Lambda + + + align:start position:0% +and we want to be able to choose Lambda +so that so this is already an extension + + align:start position:0% +so that so this is already an extension + + + align:start position:0% +so that so this is already an extension +of little U right if I take a equals 0 + + align:start position:0% +of little U right if I take a equals 0 + + + align:start position:0% +of little U right if I take a equals 0 +so I'm just taking elements in M this is + + align:start position:0% +so I'm just taking elements in M this is + + + align:start position:0% +so I'm just taking elements in M this is +U Prime of what of T is equal to U of T + + align:start position:0% +U Prime of what of T is equal to U of T + + + align:start position:0% +U Prime of what of T is equal to U of T +so it's already an extension of little U + + align:start position:0% +so it's already an extension of little U + + + align:start position:0% +so it's already an extension of little U +to this bigger Subspace and now what we + + align:start position:0% +to this bigger Subspace and now what we + + + align:start position:0% +to this bigger Subspace and now what we +want to be able to choose Lambda so that + + align:start position:0% +want to be able to choose Lambda so that + + + align:start position:0% +want to be able to choose Lambda so that +it extends it in a continuous way with + + align:start position:0% +it extends it in a continuous way with + + + align:start position:0% +it extends it in a continuous way with +the same constant being one and that + + align:start position:0% +the same constant being one and that + + + align:start position:0% +the same constant being one and that +inequality up there okay so I keep + + align:start position:0% +inequality up there okay so I keep + + + align:start position:0% +inequality up there okay so I keep +pointing up there I don't think the + + align:start position:0% +pointing up there I don't think the + + + align:start position:0% +pointing up there I don't think the +camera's like + + align:start position:0% +camera's like + + + align:start position:0% +camera's like +looking up there so you'll have to + + align:start position:0% +looking up there so you'll have to + + + align:start position:0% +looking up there so you'll have to +um + + align:start position:0% + + + + align:start position:0% + +hopefully + + align:start position:0% +hopefully + + + align:start position:0% +hopefully +interpret my meaning correctly so we + + align:start position:0% +interpret my meaning correctly so we + + + align:start position:0% +interpret my meaning correctly so we +want to choose Lambda + + align:start position:0% +want to choose Lambda + + + align:start position:0% +want to choose Lambda +complex number + + align:start position:0% +complex number + + + align:start position:0% +complex number +such that the following holds + + align:start position:0% +such that the following holds + + + align:start position:0% +such that the following holds +for all T and M A and C + + align:start position:0% +for all T and M A and C + + + align:start position:0% +for all T and M A and C +uh + + align:start position:0% +uh + + + align:start position:0% +uh +uh + + align:start position:0% +uh + + + align:start position:0% +uh +so + + align:start position:0% +so + + + align:start position:0% +so +U Prime of + + align:start position:0% +U Prime of + + + align:start position:0% +U Prime of +t plus ax which is just U of T plus a + + align:start position:0% +t plus ax which is just U of T plus a + + + align:start position:0% +t plus ax which is just U of T plus a +Lambda and absolute value is less than + + align:start position:0% +Lambda and absolute value is less than + + + align:start position:0% +Lambda and absolute value is less than +or equal to + + align:start position:0% +or equal to + + + align:start position:0% +or equal to +the + + align:start position:0% +the + + + align:start position:0% +the +Norm of t plus a Lambda if we're able to + + align:start position:0% +Norm of t plus a Lambda if we're able to + + + align:start position:0% +Norm of t plus a Lambda if we're able to +do that then U Prime is then our + + align:start position:0% +do that then U Prime is then our + + + align:start position:0% +do that then U Prime is then our +continuous extension that we're looking + + align:start position:0% +continuous extension that we're looking + + + align:start position:0% +continuous extension that we're looking +for + + align:start position:0% +for + + + align:start position:0% +for +okay + + align:start position:0% + + + + align:start position:0% + +is our + + align:start position:0% +is our + + + align:start position:0% +is our +continuous extension + + align:start position:0% +continuous extension + + + align:start position:0% +continuous extension +so all that we need to do now + + align:start position:0% +so all that we need to do now + + + align:start position:0% +so all that we need to do now +is find + + align:start position:0% +is find + + + align:start position:0% +is find +a Lambda + + align:start position:0% +a Lambda + + + align:start position:0% +a Lambda +so that this holds + + align:start position:0% +so that this holds + + + align:start position:0% +so that this holds +okay and once we've done that we've + + align:start position:0% +okay and once we've done that we've + + + align:start position:0% +okay and once we've done that we've +finished the proof + + align:start position:0% + + + + align:start position:0% + +now that thing I boxed in a minute ago + + align:start position:0% +now that thing I boxed in a minute ago + + + align:start position:0% +now that thing I boxed in a minute ago +uh we're gonna reduce it to kind of a + + align:start position:0% +uh we're gonna reduce it to kind of a + + + align:start position:0% +uh we're gonna reduce it to kind of a +simplest form + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +now + + align:start position:0% +now + + + align:start position:0% +now +um + + align:start position:0% +um + + + align:start position:0% +um +what's in the box holds regardless what + + align:start position:0% +what's in the box holds regardless what + + + align:start position:0% +what's in the box holds regardless what +Lambda is when a is equal to zero okay + + align:start position:0% +Lambda is when a is equal to zero okay + + + align:start position:0% +Lambda is when a is equal to zero okay +and now what I'm going to do is + + align:start position:0% +and now what I'm going to do is + + + align:start position:0% +and now what I'm going to do is +basically remove the fact that a can + + align:start position:0% +basically remove the fact that a can + + + align:start position:0% +basically remove the fact that a can +change + + align:start position:0% +change + + + align:start position:0% +change +so uh + + align:start position:0% + + + + align:start position:0% + +the estimate U + + align:start position:0% +the estimate U + + + align:start position:0% +the estimate U +t plus a Lambda + + align:start position:0% + + + + align:start position:0% + +less than or equal to t plus a Lambda + + align:start position:0% + + + + align:start position:0% + +holds + + align:start position:0% + + + + align:start position:0% + +when a equals zero + + align:start position:0% +when a equals zero + + + align:start position:0% +when a equals zero +regardless of how we've chosen Lambda so + + align:start position:0% +regardless of how we've chosen Lambda so + + + align:start position:0% +regardless of how we've chosen Lambda so +we just need to be able to choose Lambda + + align:start position:0% +we just need to be able to choose Lambda + + + align:start position:0% +we just need to be able to choose Lambda +so that this holds for a non-zero + + align:start position:0% + + + + align:start position:0% + +consider + + align:start position:0% +consider + + + align:start position:0% +consider +trying to choose Lambda so that this + + align:start position:0% +trying to choose Lambda so that this + + + align:start position:0% +trying to choose Lambda so that this +holds for all uh a non-zero okay now let + + align:start position:0% +holds for all uh a non-zero okay now let + + + align:start position:0% +holds for all uh a non-zero okay now let +me take this inequality here + + align:start position:0% +me take this inequality here + + + align:start position:0% +me take this inequality here +and divide it by uh the absolute value + + align:start position:0% +and divide it by uh the absolute value + + + align:start position:0% +and divide it by uh the absolute value +of a + + align:start position:0% + + + + align:start position:0% + +then + + align:start position:0% +then + + + align:start position:0% +then +that inequality + + align:start position:0% +that inequality + + + align:start position:0% +that inequality +or a not equal to so so for all a not + + align:start position:0% +or a not equal to so so for all a not + + + align:start position:0% +or a not equal to so so for all a not +equal to zero this is equivalent to uh + + align:start position:0% +equal to zero this is equivalent to uh + + + align:start position:0% +equal to zero this is equivalent to uh +if I divide by + + align:start position:0% +if I divide by + + + align:start position:0% +if I divide by +the norm of a and bring this inside the + + align:start position:0% +the norm of a and bring this inside the + + + align:start position:0% +the norm of a and bring this inside the +module inside the norm + + align:start position:0% +module inside the norm + + + align:start position:0% +module inside the norm +U of + + align:start position:0% +U of + + + align:start position:0% +U of +t + + align:start position:0% +t + + + align:start position:0% +t +minus a + + align:start position:0% +minus a + + + align:start position:0% +minus a +minus Lambda + + align:start position:0% +minus Lambda + + + align:start position:0% +minus Lambda +is less than or equal to + + align:start position:0% + + + + align:start position:0% + +or I should say this is the absolute + + align:start position:0% +or I should say this is the absolute + + + align:start position:0% +or I should say this is the absolute +value + + align:start position:0% +value + + + align:start position:0% +value +and that's the absolute value + + align:start position:0% + + + + align:start position:0% + +less than or equal to uh + + align:start position:0% +less than or equal to uh + + + align:start position:0% +less than or equal to uh +T over minus a minus Lambda + + align:start position:0% +T over minus a minus Lambda + + + align:start position:0% +T over minus a minus Lambda +for all t + + align:start position:0% +for all t + + + align:start position:0% +for all t +in M now + + align:start position:0% +in M now + + + align:start position:0% +in M now +if T is an m t over minus a is also an m + + align:start position:0% +if T is an m t over minus a is also an m + + + align:start position:0% +if T is an m t over minus a is also an m +so this bound here + + align:start position:0% +so this bound here + + + align:start position:0% +so this bound here +is equivalent to showing that we can + + align:start position:0% +is equivalent to showing that we can + + + align:start position:0% +is equivalent to showing that we can +choose Lambda so that U of + + align:start position:0% +choose Lambda so that U of + + + align:start position:0% +choose Lambda so that U of +T minus Lambda is less than or equal to + + align:start position:0% +T minus Lambda is less than or equal to + + + align:start position:0% +T minus Lambda is less than or equal to +the norm of T minus Lambda + + align:start position:0% +the norm of T minus Lambda + + + align:start position:0% +the norm of T minus Lambda +for all T in M okay so since T is the + + align:start position:0% +for all T in M okay so since T is the + + + align:start position:0% +for all T in M okay so since T is the +Subspace proving this bound or choosing + + align:start position:0% +Subspace proving this bound or choosing + + + align:start position:0% +Subspace proving this bound or choosing +Lambda so that this bound holds is + + align:start position:0% +Lambda so that this bound holds is + + + align:start position:0% +Lambda so that this bound holds is +equivalent to choosing Lambda so that + + align:start position:0% +equivalent to choosing Lambda so that + + + align:start position:0% +equivalent to choosing Lambda so that +this bound holds Okay so + + align:start position:0% +this bound holds Okay so + + + align:start position:0% +this bound holds Okay so +in sum + + align:start position:0% + + + + align:start position:0% + +or in summary + + align:start position:0% +or in summary + + + align:start position:0% +or in summary +say In Sum it's + + align:start position:0% +say In Sum it's + + + align:start position:0% +say In Sum it's +I'm thinking in terms of + + align:start position:0% + + + + align:start position:0% + +notation + + align:start position:0% +notation + + + align:start position:0% +notation +um + + align:start position:0% +um + + + align:start position:0% +um +so in summary the thing that we wanted + + align:start position:0% +so in summary the thing that we wanted + + + align:start position:0% +so in summary the thing that we wanted +to show originally that we can choose + + align:start position:0% +to show originally that we can choose + + + align:start position:0% +to show originally that we can choose +Lambda so that for all T and M a complex + + align:start position:0% +Lambda so that for all T and M a complex + + + align:start position:0% +Lambda so that for all T and M a complex +number that inequality holds is + + align:start position:0% +number that inequality holds is + + + align:start position:0% +number that inequality holds is +equivalent to showing that we can choose + + align:start position:0% +equivalent to showing that we can choose + + + align:start position:0% +equivalent to showing that we can choose +Lambda so that this inequality holds + + align:start position:0% +Lambda so that this inequality holds + + + align:start position:0% +Lambda so that this inequality holds +okay + + align:start position:0% +okay + + + align:start position:0% +okay +that's the point + + align:start position:0% + + + + align:start position:0% + +and now what we're going to do is we're + + align:start position:0% +and now what we're going to do is we're + + + align:start position:0% +and now what we're going to do is we're +going to choose the real and imaginary + + align:start position:0% +going to choose the real and imaginary + + + align:start position:0% +going to choose the real and imaginary +parts of Lambda okay and we'll choose + + align:start position:0% +parts of Lambda okay and we'll choose + + + align:start position:0% +parts of Lambda okay and we'll choose +the real part of Lambda first + + align:start position:0% +the real part of Lambda first + + + align:start position:0% +the real part of Lambda first +so we first prove + + align:start position:0% + + + + align:start position:0% + +weird I gotta get a different one + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +we first proved that there exists an + + align:start position:0% +we first proved that there exists an + + + align:start position:0% +we first proved that there exists an +alpha and r + + align:start position:0% +alpha and r + + + align:start position:0% +alpha and r +such that + + align:start position:0% +such that + + + align:start position:0% +such that +uh W of t + + align:start position:0% +uh W of t + + + align:start position:0% +uh W of t +minus Alpha + + align:start position:0% +minus Alpha + + + align:start position:0% +minus Alpha +an absolute value is less than or equal + + align:start position:0% +an absolute value is less than or equal + + + align:start position:0% +an absolute value is less than or equal +to + + align:start position:0% +to + + + align:start position:0% +to +T minus Alpha + + align:start position:0% +T minus Alpha + + + align:start position:0% +T minus Alpha +for all T and M + + align:start position:0% +for all T and M + + + align:start position:0% +for all T and M +and what is w of t + + align:start position:0% + + + + align:start position:0% + +this is equal to the real part + + align:start position:0% +this is equal to the real part + + + align:start position:0% +this is equal to the real part +of U of T + + align:start position:0% +of U of T + + + align:start position:0% +of U of T +okay + + align:start position:0% + + + + align:start position:0% + +which let me + + align:start position:0% +which let me + + + align:start position:0% +which let me +mind you this is just equal to U of T + + align:start position:0% +mind you this is just equal to U of T + + + align:start position:0% +mind you this is just equal to U of T +Plus + + align:start position:0% +Plus + + + align:start position:0% +Plus +u t complex conjugate over 2. + + align:start position:0% +u t complex conjugate over 2. + + + align:start position:0% +u t complex conjugate over 2. +all right + + align:start position:0% + + + + align:start position:0% + +okay now + + align:start position:0% +okay now + + + align:start position:0% +okay now +the real part of any complex number is + + align:start position:0% +the real part of any complex number is + + + align:start position:0% +the real part of any complex number is +always less than or equal to uh the + + align:start position:0% +always less than or equal to uh the + + + align:start position:0% +always less than or equal to uh the +absolute value of that complex number so + + align:start position:0% + + + + align:start position:0% + +then + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% + + + + align:start position:0% + +we haven't chosen what Alpha is yet I'll + + align:start position:0% +we haven't chosen what Alpha is yet I'll + + + align:start position:0% +we haven't chosen what Alpha is yet I'll +show you how to choose Alpha in just a + + align:start position:0% +show you how to choose Alpha in just a + + + align:start position:0% +show you how to choose Alpha in just a +minute note that for all T and M + + align:start position:0% +minute note that for all T and M + + + align:start position:0% +minute note that for all T and M +W of t + + align:start position:0% +W of t + + + align:start position:0% +W of t +an absolute value which remember is + + align:start position:0% +an absolute value which remember is + + + align:start position:0% +an absolute value which remember is +defined to be the real part of U of T + + align:start position:0% +defined to be the real part of U of T + + + align:start position:0% +defined to be the real part of U of T +this is less than or equal to + + align:start position:0% + + + + align:start position:0% + +absolute value of U of T because + + align:start position:0% +absolute value of U of T because + + + align:start position:0% +absolute value of U of T because +I should say the modulus of U of T the + + align:start position:0% +I should say the modulus of U of T the + + + align:start position:0% +I should say the modulus of U of T the +modulus of a complex number is the + + align:start position:0% +modulus of a complex number is the + + + align:start position:0% +modulus of a complex number is the +square root of the sum of the real part + + align:start position:0% +square root of the sum of the real part + + + align:start position:0% +square root of the sum of the real part +squared and the imaginary part squared + + align:start position:0% +squared and the imaginary part squared + + + align:start position:0% +squared and the imaginary part squared +so that's always less than or equal + + align:start position:0% +so that's always less than or equal + + + align:start position:0% +so that's always less than or equal +to that and by assumption this is less + + align:start position:0% +to that and by assumption this is less + + + align:start position:0% +to that and by assumption this is less +than or equal to + + align:start position:0% +than or equal to + + + align:start position:0% +than or equal to +the norm of t + + align:start position:0% +the norm of t + + + align:start position:0% +the norm of t +okay + + align:start position:0% +okay + + + align:start position:0% +okay +now we're going to use the part that + + align:start position:0% +now we're going to use the part that + + + align:start position:0% +now we're going to use the part that +we're going to use the fact that W is + + align:start position:0% +we're going to use the fact that W is + + + align:start position:0% +we're going to use the fact that W is +real valued + + align:start position:0% +real valued + + + align:start position:0% +real valued +then W of T1 minus w + + align:start position:0% +then W of T1 minus w + + + align:start position:0% +then W of T1 minus w +of T2 so let me say for all T1 T2 and M + + align:start position:0% +of T2 so let me say for all T1 T2 and M + + + align:start position:0% +of T2 so let me say for all T1 T2 and M +if I look at w of T1 minus W of T2 this + + align:start position:0% +if I look at w of T1 minus W of T2 this + + + align:start position:0% +if I look at w of T1 minus W of T2 this +is equal to and Since U is linear and + + align:start position:0% +is equal to and Since U is linear and + + + align:start position:0% +is equal to and Since U is linear and +taking the real part is linear it's + + align:start position:0% +taking the real part is linear it's + + + align:start position:0% +taking the real part is linear it's +this is equal to W of T1 + + align:start position:0% +this is equal to W of T1 + + + align:start position:0% +this is equal to W of T1 +minus W of T2 this is less than or equal + + align:start position:0% +minus W of T2 this is less than or equal + + + align:start position:0% +minus W of T2 this is less than or equal +to its absolute value this is where I'm + + align:start position:0% +to its absolute value this is where I'm + + + align:start position:0% +to its absolute value this is where I'm +using the fact that it's real valued + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and as we've just shown that this is + + align:start position:0% +and as we've just shown that this is + + + align:start position:0% +and as we've just shown that this is +always less than or equal to the + + align:start position:0% +always less than or equal to the + + + align:start position:0% +always less than or equal to the +absolute value + + align:start position:0% + + + + align:start position:0% + +we have that + + align:start position:0% +we have that + + + align:start position:0% +we have that +okay + + align:start position:0% + + + + align:start position:0% + +and now I'm going to do one more thing + + align:start position:0% +and now I'm going to do one more thing + + + align:start position:0% +and now I'm going to do one more thing +and add and subtract X so this is you + + align:start position:0% +and add and subtract X so this is you + + + align:start position:0% +and add and subtract X so this is you +know in the end we want + + align:start position:0% +know in the end we want + + + align:start position:0% +know in the end we want +um + + align:start position:0% +um + + + align:start position:0% +um +whoa whoa whoa whoa + + align:start position:0% +whoa whoa whoa whoa + + + align:start position:0% +whoa whoa whoa whoa +this should have been X + + align:start position:0% +this should have been X + + + align:start position:0% +this should have been X +this should have been X sorry sorry I + + align:start position:0% +this should have been X sorry sorry I + + + align:start position:0% +this should have been X sorry sorry I +hope uh you fast forward forwarded to + + align:start position:0% +hope uh you fast forward forwarded to + + + align:start position:0% +hope uh you fast forward forwarded to +this point and saw that this should have + + align:start position:0% +this point and saw that this should have + + + align:start position:0% +this point and saw that this should have +been x and x okay + + align:start position:0% +been x and x okay + + + align:start position:0% +been x and x okay +so you know in the end we want to + + align:start position:0% +so you know in the end we want to + + + align:start position:0% +so you know in the end we want to +somehow connect + + align:start position:0% +somehow connect + + + align:start position:0% +somehow connect +uh + + align:start position:0% +uh + + + align:start position:0% +uh +this to and I did it again here x + + align:start position:0% +this to and I did it again here x + + + align:start position:0% +this to and I did it again here x +to the norm of T minus X so what I'm + + align:start position:0% +to the norm of T minus X so what I'm + + + align:start position:0% +to the norm of T minus X so what I'm +going to do is add and subtract X and + + align:start position:0% +going to do is add and subtract X and + + + align:start position:0% +going to do is add and subtract X and +use the triangle inequality and this is + + align:start position:0% +use the triangle inequality and this is + + + align:start position:0% +use the triangle inequality and this is +less than or equal to + + align:start position:0% +less than or equal to + + + align:start position:0% +less than or equal to +T1 minus X Plus + + align:start position:0% +T1 minus X Plus + + + align:start position:0% +T1 minus X Plus +T2 minus X + + align:start position:0% +T2 minus X + + + align:start position:0% +T2 minus X +okay + + align:start position:0% + + + + align:start position:0% + +and therefore W of T1 minus the norm of + + align:start position:0% +and therefore W of T1 minus the norm of + + + align:start position:0% +and therefore W of T1 minus the norm of +T1 minus X + + align:start position:0% +T1 minus X + + + align:start position:0% +T1 minus X +is less than or equal to W of T2 plus + + align:start position:0% +is less than or equal to W of T2 plus + + + align:start position:0% +is less than or equal to W of T2 plus +Norm of + + align:start position:0% +Norm of + + + align:start position:0% +Norm of +T minus T2 minus X + + align:start position:0% +T minus T2 minus X + + + align:start position:0% +T minus T2 minus X +for all T1 and T2 and M + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +and now + + align:start position:0% +and now + + + align:start position:0% +and now +um + + align:start position:0% +um + + + align:start position:0% +um +so this holds for all T1 and T2 so I + + align:start position:0% +so this holds for all T1 and T2 so I + + + align:start position:0% +so this holds for all T1 and T2 so I +could fix uh T2 and take the soup over + + align:start position:0% +could fix uh T2 and take the soup over + + + align:start position:0% +could fix uh T2 and take the soup over +all t1s + + align:start position:0% + + + + align:start position:0% + +which implies that + + align:start position:0% +which implies that + + + align:start position:0% +which implies that +soup of + + align:start position:0% + + + + align:start position:0% + +so let's not make that a T1 I could just + + align:start position:0% +so let's not make that a T1 I could just + + + align:start position:0% +so let's not make that a T1 I could just +say t + + align:start position:0% + + + + align:start position:0% + +is always less than or equal to W of T2 + + align:start position:0% +is always less than or equal to W of T2 + + + align:start position:0% +is always less than or equal to W of T2 +Plus + + align:start position:0% +Plus + + + align:start position:0% +Plus +T2 minus X and this holds for all + + align:start position:0% +T2 minus X and this holds for all + + + align:start position:0% +T2 minus X and this holds for all +T2 and M + + align:start position:0% +T2 and M + + + align:start position:0% +T2 and M +so the fact that this holds for all T1 + + align:start position:0% +so the fact that this holds for all T1 + + + align:start position:0% +so the fact that this holds for all T1 +tells you this thing is an upper bound + + align:start position:0% +tells you this thing is an upper bound + + + align:start position:0% +tells you this thing is an upper bound +of this for all T and M and therefore + + align:start position:0% +of this for all T and M and therefore + + + align:start position:0% +of this for all T and M and therefore +it's supremum is less than or equal to + + align:start position:0% +it's supremum is less than or equal to + + + align:start position:0% +it's supremum is less than or equal to +this thing for all T2 and M and + + align:start position:0% +this thing for all T2 and M and + + + align:start position:0% +this thing for all T2 and M and +therefore this quantity on the left is a + + align:start position:0% +therefore this quantity on the left is a + + + align:start position:0% +therefore this quantity on the left is a +lower Bound for this thing on the right + + align:start position:0% +lower Bound for this thing on the right + + + align:start position:0% +lower Bound for this thing on the right +for all T 2 and M + + align:start position:0% +for all T 2 and M + + + align:start position:0% +for all T 2 and M +and therefore + + align:start position:0% +and therefore + + + align:start position:0% +and therefore +we conclude that the soup of T and M of + + align:start position:0% +we conclude that the soup of T and M of + + + align:start position:0% +we conclude that the soup of T and M of +w of T minus Norm of T minus X + + align:start position:0% +w of T minus Norm of T minus X + + + align:start position:0% +w of T minus Norm of T minus X +is all is less than or equal to + + align:start position:0% +is all is less than or equal to + + + align:start position:0% +is all is less than or equal to +the emph over all D and M + + align:start position:0% +the emph over all D and M + + + align:start position:0% +the emph over all D and M +uh W of t + + align:start position:0% +uh W of t + + + align:start position:0% +uh W of t +Plus + + align:start position:0% +Plus + + + align:start position:0% +Plus +T minus X + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +how do I choose Alpha so I have these + + align:start position:0% +how do I choose Alpha so I have these + + + align:start position:0% +how do I choose Alpha so I have these +two numbers here which are related in + + align:start position:0% +two numbers here which are related in + + + align:start position:0% +two numbers here which are related in +this way + + align:start position:0% + + + + align:start position:0% + +I choose Alpha + + align:start position:0% +I choose Alpha + + + align:start position:0% +I choose Alpha +between these two numbers between this + + align:start position:0% +between these two numbers between this + + + align:start position:0% +between these two numbers between this +number + + align:start position:0% +number + + + align:start position:0% +number +and this number so there's a less than + + align:start position:0% +and this number so there's a less than + + + align:start position:0% +and this number so there's a less than +or equal to sign so I can pick some + + align:start position:0% +or equal to sign so I can pick some + + + align:start position:0% +or equal to sign so I can pick some +number uh in between them maybe these + + align:start position:0% +number uh in between them maybe these + + + align:start position:0% +number uh in between them maybe these +two things are equal and therefore Alpha + + align:start position:0% +two things are equal and therefore Alpha + + + align:start position:0% +two things are equal and therefore Alpha +is equal to the to both of them or I + + align:start position:0% +is equal to the to both of them or I + + + align:start position:0% +is equal to the to both of them or I +could just choose Alpha to be this one + + align:start position:0% +could just choose Alpha to be this one + + + align:start position:0% +could just choose Alpha to be this one +it doesn't matter so uh + + align:start position:0% +it doesn't matter so uh + + + align:start position:0% +it doesn't matter so uh +okay + + align:start position:0% + + + + align:start position:0% + +all right and the proof is uh just about + + align:start position:0% +all right and the proof is uh just about + + + align:start position:0% +all right and the proof is uh just about +completed + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +now I show that now I'm going to show + + align:start position:0% +now I show that now I'm going to show + + + align:start position:0% +now I show that now I'm going to show +that this Alpha works + + align:start position:0% +that this Alpha works + + + align:start position:0% +that this Alpha works +so then + + align:start position:0% + + + + align:start position:0% + +we're all T in capital M + + align:start position:0% +we're all T in capital M + + + align:start position:0% +we're all T in capital M +I have W of t + + align:start position:0% +I have W of t + + + align:start position:0% +I have W of t +minus + + align:start position:0% +minus + + + align:start position:0% +minus +Norm of T minus X is less than or equal + + align:start position:0% +Norm of T minus X is less than or equal + + + align:start position:0% +Norm of T minus X is less than or equal +to Alpha + + align:start position:0% +to Alpha + + + align:start position:0% +to Alpha +is less than or equal to + + align:start position:0% +is less than or equal to + + + align:start position:0% +is less than or equal to +W of t uh + + align:start position:0% +W of t uh + + + align:start position:0% +W of t uh +plus Norm of T minus X + + align:start position:0% + + + + align:start position:0% + +and therefore + + align:start position:0% + + + + align:start position:0% + +it's less than or equal to Alpha minus W + + align:start position:0% +it's less than or equal to Alpha minus W + + + align:start position:0% +it's less than or equal to Alpha minus W +of t + + align:start position:0% +of t + + + align:start position:0% +of t +is less than or equal to Norm of T minus + + align:start position:0% +is less than or equal to Norm of T minus + + + align:start position:0% +is less than or equal to Norm of T minus +X + + align:start position:0% + + + + align:start position:0% + +which is the same as Alpha minus W of t + + align:start position:0% +which is the same as Alpha minus W of t + + + align:start position:0% +which is the same as Alpha minus W of t +um I should say + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +all right so we showed how to do it for + + align:start position:0% +all right so we showed how to do it for + + + align:start position:0% +all right so we showed how to do it for +we're able to choose an alpha so that + + align:start position:0% +we're able to choose an alpha so that + + + align:start position:0% +we're able to choose an alpha so that +essentially this inequality holds for + + align:start position:0% +essentially this inequality holds for + + + align:start position:0% +essentially this inequality holds for +the real part we can do that also for + + align:start position:0% +the real part we can do that also for + + + align:start position:0% +the real part we can do that also for +the imaginary part \ No newline at end of file diff --git a/LvI6V3VbL9Q.txt b/LvI6V3VbL9Q.txt new file mode 100644 index 0000000000000000000000000000000000000000..79acace452fda87fe147034bff4faa6733e9442c --- /dev/null +++ b/LvI6V3VbL9Q.txt @@ -0,0 +1,17491 @@ +align:start position:0% + +so last week i talked about + + align:start position:0% +so last week i talked about + + + align:start position:0% +so last week i talked about +uh what did i talk about i talked about + + align:start position:0% +uh what did i talk about i talked about + + + align:start position:0% +uh what did i talk about i talked about +uh an introduction to molecular biology + + align:start position:0% +uh an introduction to molecular biology + + + align:start position:0% +uh an introduction to molecular biology +for about 10 or 12 slides and then since + + align:start position:0% +for about 10 or 12 slides and then since + + + align:start position:0% +for about 10 or 12 slides and then since +we're going pretty quickly i covered + + align:start position:0% +we're going pretty quickly i covered + + + align:start position:0% +we're going pretty quickly i covered +a lot of this material on gene + + align:start position:0% +a lot of this material on gene + + + align:start position:0% +a lot of this material on gene +measurement techniques + + align:start position:0% + + + + align:start position:0% + +and uh so we've already had one question + + align:start position:0% +and uh so we've already had one question + + + align:start position:0% +and uh so we've already had one question +or one request to talk about something + + align:start position:0% +or one request to talk about something + + + align:start position:0% +or one request to talk about something +i've actually flipped pretty quickly + + align:start position:0% +i've actually flipped pretty quickly + + + align:start position:0% +i've actually flipped pretty quickly +through this concept of sage and how + + align:start position:0% +through this concept of sage and how + + + align:start position:0% +through this concept of sage and how +does sage use two metro microwaves and + + align:start position:0% +does sage use two metro microwaves and + + + align:start position:0% +does sage use two metro microwaves and +actually it's uh measure rna and it's + + align:start position:0% +actually it's uh measure rna and it's + + + align:start position:0% +actually it's uh measure rna and it's +quite important that we actually talk + + align:start position:0% +quite important that we actually talk + + + align:start position:0% +quite important that we actually talk +about sage i think but i'm going to + + align:start position:0% +about sage i think but i'm going to + + + align:start position:0% +about sage i think but i'm going to +start the discussion with sage talking + + align:start position:0% +start the discussion with sage talking + + + align:start position:0% +start the discussion with sage talking +about microarrays again for a second + + align:start position:0% +about microarrays again for a second + + + align:start position:0% +about microarrays again for a second +okay so i already talked about + + align:start position:0% +okay so i already talked about + + + align:start position:0% +okay so i already talked about +microarrays how these are man-made grids + + align:start position:0% +microarrays how these are man-made grids + + + align:start position:0% +microarrays how these are man-made grids +of dna each spot in the grid is looking + + align:start position:0% +of dna each spot in the grid is looking + + + align:start position:0% +of dna each spot in the grid is looking +for one particular + + align:start position:0% +for one particular + + + align:start position:0% +for one particular +rna + + align:start position:0% +rna + + + align:start position:0% +rna +and in fact more than one spot might be + + align:start position:0% +and in fact more than one spot might be + + + align:start position:0% +and in fact more than one spot might be +actually hybridizing to one rna it + + align:start position:0% +actually hybridizing to one rna it + + + align:start position:0% +actually hybridizing to one rna it +doesn't have to be one to one it could + + align:start position:0% +doesn't have to be one to one it could + + + align:start position:0% +doesn't have to be one to one it could +be many to one + + align:start position:0% +be many to one + + + align:start position:0% +be many to one +and i just want to talk about the + + align:start position:0% +and i just want to talk about the + + + align:start position:0% +and i just want to talk about the +differences of the two technologies for + + align:start position:0% +differences of the two technologies for + + + align:start position:0% +differences of the two technologies for +microarrays and then talk about how that + + align:start position:0% +microarrays and then talk about how that + + + align:start position:0% +microarrays and then talk about how that +actually leads itself to the sage + + align:start position:0% +actually leads itself to the sage + + + align:start position:0% +actually leads itself to the sage +discussion + + align:start position:0% +discussion + + + align:start position:0% +discussion +so for the past uh coming up on 10 years + + align:start position:0% +so for the past uh coming up on 10 years + + + align:start position:0% +so for the past uh coming up on 10 years +now there have been two technologies to + + align:start position:0% +now there have been two technologies to + + + align:start position:0% +now there have been two technologies to +make microarrays okay there's an + + align:start position:0% +make microarrays okay there's an + + + align:start position:0% +make microarrays okay there's an +oligonucleotide approach in the cdna + + align:start position:0% +oligonucleotide approach in the cdna + + + align:start position:0% +oligonucleotide approach in the cdna +approach the analogy i like to use is + + align:start position:0% +approach the analogy i like to use is + + + align:start position:0% +approach the analogy i like to use is +this okay if you think of a microwave as + + align:start position:0% +this okay if you think of a microwave as + + + align:start position:0% +this okay if you think of a microwave as +say + + align:start position:0% +say + + + align:start position:0% +say +manhattan with all the skyscrapers okay + + align:start position:0% +manhattan with all the skyscrapers okay + + + align:start position:0% +manhattan with all the skyscrapers okay +if you had to rebuild manhattan there's + + align:start position:0% +if you had to rebuild manhattan there's + + + align:start position:0% +if you had to rebuild manhattan there's +two ways you could do it + + align:start position:0% +two ways you could do it + + + align:start position:0% +two ways you could do it +you could take one skyscraper at a time + + align:start position:0% +you could take one skyscraper at a time + + + align:start position:0% +you could take one skyscraper at a time +and put them into place + + align:start position:0% +and put them into place + + + align:start position:0% +and put them into place +or you could just build all the first + + align:start position:0% +or you could just build all the first + + + align:start position:0% +or you could just build all the first +floors all the second floors all the + + align:start position:0% +floors all the second floors all the + + + align:start position:0% +floors all the second floors all the +third floors all the fourth floors and + + align:start position:0% +third floors all the fourth floors and + + + align:start position:0% +third floors all the fourth floors and +that's essentially the differences + + align:start position:0% +that's essentially the differences + + + align:start position:0% +that's essentially the differences +between these two technologies okay so + + align:start position:0% +between these two technologies okay so + + + align:start position:0% +between these two technologies okay so +the oligonucleotide arrays primarily + + align:start position:0% +the oligonucleotide arrays primarily + + + align:start position:0% +the oligonucleotide arrays primarily +made by femetrix they're made each of + + align:start position:0% +made by femetrix they're made each of + + + align:start position:0% +made by femetrix they're made each of +the skyscrapers the equivalent that each + + align:start position:0% +the skyscrapers the equivalent that each + + + align:start position:0% +the skyscrapers the equivalent that each +of the strands of dna are only 25 + + align:start position:0% +of the strands of dna are only 25 + + + align:start position:0% +of the strands of dna are only 25 +nucleotides long but they're built one + + align:start position:0% +nucleotides long but they're built one + + + align:start position:0% +nucleotides long but they're built one +base pair at a time + + align:start position:0% +base pair at a time + + + align:start position:0% +base pair at a time +because they're only 25 nucleotides long + + align:start position:0% +because they're only 25 nucleotides long + + + align:start position:0% +because they're only 25 nucleotides long +and genes are much longer than that + + align:start position:0% +and genes are much longer than that + + + align:start position:0% +and genes are much longer than that +that's why they have multiple probes + + align:start position:0% +that's why they have multiple probes + + + align:start position:0% +that's why they have multiple probes +going against a particular gene + + align:start position:0% +going against a particular gene + + + align:start position:0% +going against a particular gene +the cdna on the other hand are + + align:start position:0% +the cdna on the other hand are + + + align:start position:0% +the cdna on the other hand are +essentially strands of dna that will + + align:start position:0% +essentially strands of dna that will + + + align:start position:0% +essentially strands of dna that will +hybridize the rna but the strands of dna + + align:start position:0% +hybridize the rna but the strands of dna + + + align:start position:0% +hybridize the rna but the strands of dna +that are just put into place using + + align:start position:0% +that are just put into place using + + + align:start position:0% +that are just put into place using +primarily using something like a robotic + + align:start position:0% +primarily using something like a robotic + + + align:start position:0% +primarily using something like a robotic +spotter so it might pick up four at a + + align:start position:0% +spotter so it might pick up four at a + + + align:start position:0% +spotter so it might pick up four at a +time or 16 at a time or just one at a + + align:start position:0% +time or 16 at a time or just one at a + + + align:start position:0% +time or 16 at a time or just one at a +time but that's how these two are made + + align:start position:0% +time but that's how these two are made + + + align:start position:0% +time but that's how these two are made +from beyond the technology difference + + align:start position:0% +from beyond the technology difference + + + align:start position:0% +from beyond the technology difference +here + + align:start position:0% +here + + + align:start position:0% +here +there's a major difference in what + + align:start position:0% +there's a major difference in what + + + align:start position:0% +there's a major difference in what +exactly these microwaves are measuring + + align:start position:0% +exactly these microwaves are measuring + + + align:start position:0% +exactly these microwaves are measuring +okay the cdna arrays are measuring + + align:start position:0% +okay the cdna arrays are measuring + + + align:start position:0% +okay the cdna arrays are measuring +relative expression amounts so you have + + align:start position:0% +relative expression amounts so you have + + + align:start position:0% +relative expression amounts so you have +to put two samples on there + + align:start position:0% +to put two samples on there + + + align:start position:0% +to put two samples on there +okay one of which the rna might be + + align:start position:0% +okay one of which the rna might be + + + align:start position:0% +okay one of which the rna might be +colored red another which the rna might + + align:start position:0% +colored red another which the rna might + + + align:start position:0% +colored red another which the rna might +be colored green + + align:start position:0% +be colored green + + + align:start position:0% +be colored green +and you'll look at the you know what + + align:start position:0% +and you'll look at the you know what + + + align:start position:0% +and you'll look at the you know what +people will do is after they've + + align:start position:0% +people will do is after they've + + + align:start position:0% +people will do is after they've +hybridized it they've taken the tiff + + align:start position:0% +hybridized it they've taken the tiff + + + align:start position:0% +hybridized it they've taken the tiff +image of this to look at the relative + + align:start position:0% +image of this to look at the relative + + + align:start position:0% +image of this to look at the relative +ratio of how much red is there compared + + align:start position:0% +ratio of how much red is there compared + + + align:start position:0% +ratio of how much red is there compared +to how much green so in that you always + + align:start position:0% +to how much green so in that you always + + + align:start position:0% +to how much green so in that you always +have a relative expression level + + align:start position:0% +have a relative expression level + + + align:start position:0% +have a relative expression level +in theory the oligonucleotide approach + + align:start position:0% +in theory the oligonucleotide approach + + + align:start position:0% +in theory the oligonucleotide approach +is different now this is relative + + align:start position:0% +is different now this is relative + + + align:start position:0% +is different now this is relative +because each of the strands of cd dna + + align:start position:0% +because each of the strands of cd dna + + + align:start position:0% +because each of the strands of cd dna +has its own properties okay each of the + + align:start position:0% +has its own properties okay each of the + + + align:start position:0% +has its own properties okay each of the +strands might have a different set of + + align:start position:0% +strands might have a different set of + + + align:start position:0% +strands might have a different set of +g's and a's and t's and c's different + + align:start position:0% +g's and a's and t's and c's different + + + align:start position:0% +g's and a's and t's and c's different +melting temperatures and that's why you + + align:start position:0% +melting temperatures and that's why you + + + align:start position:0% +melting temperatures and that's why you +can't really use that as an absolute + + align:start position:0% +can't really use that as an absolute + + + align:start position:0% +can't really use that as an absolute +measurement an intensity might be lower + + align:start position:0% +measurement an intensity might be lower + + + align:start position:0% +measurement an intensity might be lower +on one of these arrays not because + + align:start position:0% +on one of these arrays not because + + + align:start position:0% +on one of these arrays not because +there's less of a gene present just only + + align:start position:0% +there's less of a gene present just only + + + align:start position:0% +there's less of a gene present just only +because the actual cdna had a little bit + + align:start position:0% +because the actual cdna had a little bit + + + align:start position:0% +because the actual cdna had a little bit +different biochemical properties and + + align:start position:0% +different biochemical properties and + + + align:start position:0% +different biochemical properties and +wasn't hybridizing efficiently + + align:start position:0% +wasn't hybridizing efficiently + + + align:start position:0% +wasn't hybridizing efficiently +the oligonucleotide arrays on the other + + align:start position:0% +the oligonucleotide arrays on the other + + + align:start position:0% +the oligonucleotide arrays on the other +hand are in theory designed so that each + + align:start position:0% +hand are in theory designed so that each + + + align:start position:0% +hand are in theory designed so that each +of the probes + + align:start position:0% +of the probes + + + align:start position:0% +of the probes +has similar characteristics in terms of + + align:start position:0% +has similar characteristics in terms of + + + align:start position:0% +has similar characteristics in terms of +melting temperature and some of these + + align:start position:0% +melting temperature and some of these + + + align:start position:0% +melting temperature and some of these +other characteristics so in theory you + + align:start position:0% +other characteristics so in theory you + + + align:start position:0% +other characteristics so in theory you +can compare one spot to another spot and + + align:start position:0% +can compare one spot to another spot and + + + align:start position:0% +can compare one spot to another spot and +because of that these are made + + align:start position:0% +because of that these are made + + + align:start position:0% +because of that these are made +these are hybridized using a single + + align:start position:0% +these are hybridized using a single + + + align:start position:0% +these are hybridized using a single +sample so you put one sample on one + + align:start position:0% +sample so you put one sample on one + + + align:start position:0% +sample so you put one sample on one +array here if you want to do a relative + + align:start position:0% +array here if you want to do a relative + + + align:start position:0% +array here if you want to do a relative +difference you use two arrays + + align:start position:0% +difference you use two arrays + + + align:start position:0% +difference you use two arrays +now again in theory this is an absolute + + align:start position:0% +now again in theory this is an absolute + + + align:start position:0% +now again in theory this is an absolute +expression amount if people want to get + + align:start position:0% +expression amount if people want to get + + + align:start position:0% +expression amount if people want to get +to the most absolute measure like how + + align:start position:0% +to the most absolute measure like how + + + align:start position:0% +to the most absolute measure like how +many strands of rna is present okay or + + align:start position:0% +many strands of rna is present okay or + + + align:start position:0% +many strands of rna is present okay or +present + + align:start position:0% +present + + + align:start position:0% +present +then there's another technology called + + align:start position:0% +then there's another technology called + + + align:start position:0% +then there's another technology called +sage and that's well that's how i just + + align:start position:0% +sage and that's well that's how i just + + + align:start position:0% +sage and that's well that's how i just +want to introduce that discussion here + + align:start position:0% + + + + align:start position:0% + +so sage stands for serial analysis of + + align:start position:0% +so sage stands for serial analysis of + + + align:start position:0% +so sage stands for serial analysis of +gene expression i think the paper the + + align:start position:0% +gene expression i think the paper the + + + align:start position:0% +gene expression i think the paper the +original paper on this was in science it + + align:start position:0% +original paper on this was in science it + + + align:start position:0% +original paper on this was in science it +was like a one or two page paper back in + + align:start position:0% +was like a one or two page paper back in + + + align:start position:0% +was like a one or two page paper back in +1995 by uh it was victor velkalescu + + align:start position:0% +1995 by uh it was victor velkalescu + + + align:start position:0% +1995 by uh it was victor velkalescu +at hopkins and so this actually was + + align:start position:0% +at hopkins and so this actually was + + + align:start position:0% +at hopkins and so this actually was +developed around the same time as + + align:start position:0% +developed around the same time as + + + align:start position:0% +developed around the same time as +microwaves but actually gained a lot of + + align:start position:0% +microwaves but actually gained a lot of + + + align:start position:0% +microwaves but actually gained a lot of +popularity before microwaves became so + + align:start position:0% +popularity before microwaves became so + + + align:start position:0% +popularity before microwaves became so +commonly available essentially the way + + align:start position:0% +commonly available essentially the way + + + align:start position:0% +commonly available essentially the way +sage works is that it gives you an + + align:start position:0% +sage works is that it gives you an + + + align:start position:0% +sage works is that it gives you an +absolute expression level for a + + align:start position:0% +absolute expression level for a + + + align:start position:0% +absolute expression level for a +particular gene but it measures gene + + align:start position:0% +particular gene but it measures gene + + + align:start position:0% +particular gene but it measures gene +expression by sequencing and automated + + align:start position:0% +expression by sequencing and automated + + + align:start position:0% +expression by sequencing and automated +sequences were just coming around at the + + align:start position:0% +sequences were just coming around at the + + + align:start position:0% +sequences were just coming around at the +time and people realized that you can + + align:start position:0% +time and people realized that you can + + + align:start position:0% +time and people realized that you can +use this technique to use them to + + align:start position:0% +use this technique to use them to + + + align:start position:0% +use this technique to use them to +measure rna expression levels + + align:start position:0% +measure rna expression levels + + + align:start position:0% +measure rna expression levels +so the way this works is this is that in + + align:start position:0% +so the way this works is this is that in + + + align:start position:0% +so the way this works is this is that in +theory every rna or let's say every + + align:start position:0% +theory every rna or let's say every + + + align:start position:0% +theory every rna or let's say every +sequence every gene + + align:start position:0% +sequence every gene + + + align:start position:0% +sequence every gene +has what they call a is a sage tag here + + align:start position:0% +has what they call a is a sage tag here + + + align:start position:0% +has what they call a is a sage tag here +okay and all sage tag is is let's say 10 + + align:start position:0% +okay and all sage tag is is let's say 10 + + + align:start position:0% +okay and all sage tag is is let's say 10 +nucleotides + + align:start position:0% +nucleotides + + + align:start position:0% +nucleotides +that hopefully uniquely identify that + + align:start position:0% +that hopefully uniquely identify that + + + align:start position:0% +that hopefully uniquely identify that +gene + + align:start position:0% +gene + + + align:start position:0% +gene +but the catch is it has to be after a + + align:start position:0% +but the catch is it has to be after a + + + align:start position:0% +but the catch is it has to be after a +catg and we'll see why in a moment okay + + align:start position:0% +catg and we'll see why in a moment okay + + + align:start position:0% +catg and we'll see why in a moment okay +so look at a gene you look for catg and + + align:start position:0% +so look at a gene you look for catg and + + + align:start position:0% +so look at a gene you look for catg and +the most downstream 10 nucleotides are + + align:start position:0% +the most downstream 10 nucleotides are + + + align:start position:0% +the most downstream 10 nucleotides are +going to be the tag for that gene + + align:start position:0% +going to be the tag for that gene + + + align:start position:0% +going to be the tag for that gene +hopefully that's enough to make it + + align:start position:0% +hopefully that's enough to make it + + + align:start position:0% +hopefully that's enough to make it +unique + + align:start position:0% +unique + + + align:start position:0% +unique +but that's not always going to be the + + align:start position:0% +but that's not always going to be the + + + align:start position:0% +but that's not always going to be the +case + + align:start position:0% +case + + + align:start position:0% +case +so the way this works is this if you + + align:start position:0% +so the way this works is this if you + + + align:start position:0% +so the way this works is this if you +start with the strands of rna that + + align:start position:0% +start with the strands of rna that + + + align:start position:0% +start with the strands of rna that +you're going to measure + + align:start position:0% +you're going to measure + + + align:start position:0% +you're going to measure +the first thing you want to do is to + + align:start position:0% +the first thing you want to do is to + + + align:start position:0% +the first thing you want to do is to +make a strand of dna okay rna is very + + align:start position:0% +make a strand of dna okay rna is very + + + align:start position:0% +make a strand of dna okay rna is very +fragile you want to convert it to dna as + + align:start position:0% +fragile you want to convert it to dna as + + + align:start position:0% +fragile you want to convert it to dna as +quickly as you can otherwise it's going + + align:start position:0% +quickly as you can otherwise it's going + + + align:start position:0% +quickly as you can otherwise it's going +to start to degrade + + align:start position:0% +to start to degrade + + + align:start position:0% +to start to degrade +so the techniques for taking a strand of + + align:start position:0% +so the techniques for taking a strand of + + + align:start position:0% +so the techniques for taking a strand of +rna and making a strand of dna are + + align:start position:0% +rna and making a strand of dna are + + + align:start position:0% +rna and making a strand of dna are +commonly available it's a reverse + + align:start position:0% +commonly available it's a reverse + + + align:start position:0% +commonly available it's a reverse +transcriptase you can buy this off the + + align:start position:0% +transcriptase you can buy this off the + + + align:start position:0% +transcriptase you can buy this off the +shelf or you can buy from the store + + align:start position:0% +shelf or you can buy from the store + + + align:start position:0% +shelf or you can buy from the store +essentially it's going to start by going + + align:start position:0% +essentially it's going to start by going + + + align:start position:0% +essentially it's going to start by going +at one end you might give it a primer to + + align:start position:0% +at one end you might give it a primer to + + + align:start position:0% +at one end you might give it a primer to +get started and then it's just going to + + align:start position:0% +get started and then it's just going to + + + align:start position:0% +get started and then it's just going to +go all the way until it falls off the + + align:start position:0% +go all the way until it falls off the + + + align:start position:0% +go all the way until it falls off the +end so now you've made a cdna copy of + + align:start position:0% +end so now you've made a cdna copy of + + + align:start position:0% +end so now you've made a cdna copy of +this + + align:start position:0% +this + + + align:start position:0% +this +and what you do now is you can do that + + align:start position:0% +and what you do now is you can do that + + + align:start position:0% +and what you do now is you can do that +for the other strand as well so you have + + align:start position:0% +for the other strand as well so you have + + + align:start position:0% +for the other strand as well so you have +now you've gotten rid of the rna and you + + align:start position:0% +now you've gotten rid of the rna and you + + + align:start position:0% +now you've gotten rid of the rna and you +have two you have a double strand of dna + + align:start position:0% +have two you have a double strand of dna + + + align:start position:0% +have two you have a double strand of dna +representing the rna that you had in + + align:start position:0% +representing the rna that you had in + + + align:start position:0% +representing the rna that you had in +your original sample + + align:start position:0% +your original sample + + + align:start position:0% +your original sample +now it gets a little tricky + + align:start position:0% +now it gets a little tricky + + + align:start position:0% +now it gets a little tricky +because now we're essentially going to + + align:start position:0% +because now we're essentially going to + + + align:start position:0% +because now we're essentially going to +use a lot of molecular tools that + + align:start position:0% +use a lot of molecular tools that + + + align:start position:0% +use a lot of molecular tools that +bacteria have to actually do this kind + + align:start position:0% +bacteria have to actually do this kind + + + align:start position:0% +bacteria have to actually do this kind +of fancy cutting and pasting so that we + + align:start position:0% +of fancy cutting and pasting so that we + + + align:start position:0% +of fancy cutting and pasting so that we +can sequence this and figure out what + + align:start position:0% +can sequence this and figure out what + + + align:start position:0% +can sequence this and figure out what +the genes are what the gene expression + + align:start position:0% +the genes are what the gene expression + + + align:start position:0% +the genes are what the gene expression +level is there's a particular + + align:start position:0% +level is there's a particular + + + align:start position:0% +level is there's a particular +restriction enzyme so a restriction + + align:start position:0% +restriction enzyme so a restriction + + + align:start position:0% +restriction enzyme so a restriction +enzyme is actually a component it's a + + align:start position:0% +enzyme is actually a component it's a + + + align:start position:0% +enzyme is actually a component it's a +it's a protein certainly but it's an + + align:start position:0% +it's a protein certainly but it's an + + + align:start position:0% +it's a protein certainly but it's an +enzyme that's present in bacteria that + + align:start position:0% +enzyme that's present in bacteria that + + + align:start position:0% +enzyme that's present in bacteria that +goes around cutting dna at particular + + align:start position:0% +goes around cutting dna at particular + + + align:start position:0% +goes around cutting dna at particular +sequences + + align:start position:0% +sequences + + + align:start position:0% +sequences +there's a lot of restriction enzymes out + + align:start position:0% +there's a lot of restriction enzymes out + + + align:start position:0% +there's a lot of restriction enzymes out +there if you get the current catalog or + + align:start position:0% +there if you get the current catalog or + + + align:start position:0% +there if you get the current catalog or +the current poster they might be on the + + align:start position:0% +the current poster they might be on the + + + align:start position:0% +the current poster they might be on the +order of let's say about 300 of these + + align:start position:0% +order of let's say about 300 of these + + + align:start position:0% +order of let's say about 300 of these +restriction enzymes there are there are + + align:start position:0% +restriction enzymes there are there are + + + align:start position:0% +restriction enzymes there are there are +many ways to define them but one way + + align:start position:0% +many ways to define them but one way + + + align:start position:0% +many ways to define them but one way +people define restriction enzymes is + + align:start position:0% +people define restriction enzymes is + + + align:start position:0% +people define restriction enzymes is +based on the sequence it cuts + + align:start position:0% +based on the sequence it cuts + + + align:start position:0% +based on the sequence it cuts +and so there's some that cut dna giving + + align:start position:0% +and so there's some that cut dna giving + + + align:start position:0% +and so there's some that cut dna giving +absolutely flat ends and there's some + + align:start position:0% +absolutely flat ends and there's some + + + align:start position:0% +absolutely flat ends and there's some +that actually cut leaving sticky ends + + align:start position:0% +that actually cut leaving sticky ends + + + align:start position:0% +that actually cut leaving sticky ends +and so here this particular restriction + + align:start position:0% +and so here this particular restriction + + + align:start position:0% +and so here this particular restriction +enzyme called nla + + align:start position:0% +enzyme called nla + + + align:start position:0% +enzyme called nla +nla3 + + align:start position:0% +nla3 + + + align:start position:0% +nla3 +takes any strand of double-stranded dna + + align:start position:0% +takes any strand of double-stranded dna + + + align:start position:0% +takes any strand of double-stranded dna +and cuts it at the catg but it leaves + + align:start position:0% +and cuts it at the catg but it leaves + + + align:start position:0% +and cuts it at the catg but it leaves +the catg as an overhang it doesn't cut + + align:start position:0% +the catg as an overhang it doesn't cut + + + align:start position:0% +the catg as an overhang it doesn't cut +it flat okay + + align:start position:0% +it flat okay + + + align:start position:0% +it flat okay +so these guys saw this and they said + + align:start position:0% +so these guys saw this and they said + + + align:start position:0% +so these guys saw this and they said +well we could do some interesting things + + align:start position:0% +well we could do some interesting things + + + align:start position:0% +well we could do some interesting things +a little bit of cutting and basically + + align:start position:0% +a little bit of cutting and basically + + + align:start position:0% +a little bit of cutting and basically +actually take advantage of this + + align:start position:0% +actually take advantage of this + + + align:start position:0% +actually take advantage of this +so to be clear here's this here's the + + align:start position:0% +so to be clear here's this here's the + + + align:start position:0% +so to be clear here's this here's the +sequence here's the citg and the unique + + align:start position:0% +sequence here's the citg and the unique + + + align:start position:0% +sequence here's the citg and the unique +tag and basically we're gonna even + + align:start position:0% +tag and basically we're gonna even + + + align:start position:0% +tag and basically we're gonna even +though the strand might be longer than + + align:start position:0% +though the strand might be longer than + + + align:start position:0% +though the strand might be longer than +this it's gonna get cut like this + + align:start position:0% +this it's gonna get cut like this + + + align:start position:0% +this it's gonna get cut like this +okay + + align:start position:0% +okay + + + align:start position:0% +okay +now to use more fancy parts to this + + align:start position:0% +now to use more fancy parts to this + + + align:start position:0% +now to use more fancy parts to this +remember how i told you most messenger + + align:start position:0% +remember how i told you most messenger + + + align:start position:0% +remember how i told you most messenger +rna has a strand of a at the end right + + align:start position:0% +rna has a strand of a at the end right + + + align:start position:0% +rna has a strand of a at the end right +because as it's being copied off the dna + + align:start position:0% +because as it's being copied off the dna + + + align:start position:0% +because as it's being copied off the dna +it starts to stutter in some ways and + + align:start position:0% +it starts to stutter in some ways and + + + align:start position:0% +it starts to stutter in some ways and +just leaves a poly a + + align:start position:0% +just leaves a poly a + + + align:start position:0% +just leaves a poly a +and that you can cut you can bind to it + + align:start position:0% +and that you can cut you can bind to it + + + align:start position:0% +and that you can cut you can bind to it +or you can actually find it by using a + + align:start position:0% +or you can actually find it by using a + + + align:start position:0% +or you can actually find it by using a +poly t + + align:start position:0% +poly t + + + align:start position:0% +poly t +what they're using their technique what + + align:start position:0% +what they're using their technique what + + + align:start position:0% +what they're using their technique what +you can do is instead of just starting + + align:start position:0% +you can do is instead of just starting + + + align:start position:0% +you can do is instead of just starting +with p start it with something that's + + align:start position:0% +with p start it with something that's + + + align:start position:0% +with p start it with something that's +with peas and something sticky on the + + align:start position:0% +with peas and something sticky on the + + + align:start position:0% +with peas and something sticky on the +end okay in other words it's labeled in + + align:start position:0% +end okay in other words it's labeled in + + + align:start position:0% +end okay in other words it's labeled in +such a way that we can then fish these + + align:start position:0% +such a way that we can then fish these + + + align:start position:0% +such a way that we can then fish these +out + + align:start position:0% +out + + + align:start position:0% +out +after we apply a magnet to it for + + align:start position:0% +after we apply a magnet to it for + + + align:start position:0% +after we apply a magnet to it for +example or up uh or + + align:start position:0% +example or up uh or + + + align:start position:0% +example or up uh or +some people use uh streptavidin and + + align:start position:0% +some people use uh streptavidin and + + + align:start position:0% +some people use uh streptavidin and +biotinylation as a common way to + + align:start position:0% +biotinylation as a common way to + + + align:start position:0% +biotinylation as a common way to +actually pull fish these things out when + + align:start position:0% +actually pull fish these things out when + + + align:start position:0% +actually pull fish these things out when +you run through a column for example or + + align:start position:0% +you run through a column for example or + + + align:start position:0% +you run through a column for example or +spin it with particular beads however + + align:start position:0% +spin it with particular beads however + + + align:start position:0% +spin it with particular beads however +you do it so now we have a whole bunch + + align:start position:0% +you do it so now we have a whole bunch + + + align:start position:0% +you do it so now we have a whole bunch +of + + align:start position:0% +of + + + align:start position:0% +of +the double stranded dnase except we have + + align:start position:0% +the double stranded dnase except we have + + + align:start position:0% +the double stranded dnase except we have +this little overhang here we've got all + + align:start position:0% +this little overhang here we've got all + + + align:start position:0% +this little overhang here we've got all +the a's and t's on that end we've fished + + align:start position:0% +the a's and t's on that end we've fished + + + align:start position:0% +the a's and t's on that end we've fished +them out of this big cellular pool + + align:start position:0% +them out of this big cellular pool + + + align:start position:0% +them out of this big cellular pool +cellular mess + + align:start position:0% +cellular mess + + + align:start position:0% +cellular mess +now what we're going to do okay it + + align:start position:0% +now what we're going to do okay it + + + align:start position:0% +now what we're going to do okay it +starts to get a little tricky but now so + + align:start position:0% +starts to get a little tricky but now so + + + align:start position:0% +starts to get a little tricky but now so +we have this tag here keep your eye on + + align:start position:0% +we have this tag here keep your eye on + + + align:start position:0% +we have this tag here keep your eye on +the red that's all i can say here in + + align:start position:0% +the red that's all i can say here in + + + align:start position:0% +the red that's all i can say here in +this technique okay because what you're + + align:start position:0% +this technique okay because what you're + + + align:start position:0% +this technique okay because what you're +going to do is in the end you're going + + align:start position:0% +going to do is in the end you're going + + + align:start position:0% +going to do is in the end you're going +to see + + align:start position:0% +to see + + + align:start position:0% +to see +how we're going to be able to use a + + align:start position:0% +how we're going to be able to use a + + + align:start position:0% +how we're going to be able to use a +sequencer to tell these rnas how much of + + align:start position:0% +sequencer to tell these rnas how much of + + + align:start position:0% +sequencer to tell these rnas how much of +each rna is present so we've got one rna + + align:start position:0% +each rna is present so we've got one rna + + + align:start position:0% +each rna is present so we've got one rna +going this way and we actually got this + + align:start position:0% +going this way and we actually got this + + + align:start position:0% +going this way and we actually got this +light blue for another rna going this + + align:start position:0% +light blue for another rna going this + + + align:start position:0% +light blue for another rna going this +way and you can see how they're going to + + align:start position:0% +way and you can see how they're going to + + + align:start position:0% +way and you can see how they're going to +end up being next to each other + + align:start position:0% +end up being next to each other + + + align:start position:0% +end up being next to each other +so what we have to do then is add an + + align:start position:0% +so what we have to do then is add an + + + align:start position:0% +so what we have to do then is add an +adapter that has another sticky end here + + align:start position:0% +adapter that has another sticky end here + + + align:start position:0% +adapter that has another sticky end here +and add it to this side here + + align:start position:0% +and add it to this side here + + + align:start position:0% +and add it to this side here +and we're going to use another + + align:start position:0% +and we're going to use another + + + align:start position:0% +and we're going to use another +restriction enzyme + + align:start position:0% +restriction enzyme + + + align:start position:0% +restriction enzyme +that's going to cut + + align:start position:0% +that's going to cut + + + align:start position:0% +that's going to cut +at the catg but it's going to cut after + + align:start position:0% +at the catg but it's going to cut after + + + align:start position:0% +at the catg but it's going to cut after +the tag there's one particular + + align:start position:0% +the tag there's one particular + + + align:start position:0% +the tag there's one particular +restriction enzyme called bsm f1 + + align:start position:0% +restriction enzyme called bsm f1 + + + align:start position:0% +restriction enzyme called bsm f1 +that looks it for catg but doesn't cut + + align:start position:0% +that looks it for catg but doesn't cut + + + align:start position:0% +that looks it for catg but doesn't cut +at the ctg it cuts 14 base pairs + + align:start position:0% +at the ctg it cuts 14 base pairs + + + align:start position:0% +at the ctg it cuts 14 base pairs +downstream from there that's why our + + align:start position:0% +downstream from there that's why our + + + align:start position:0% +downstream from there that's why our +tags have to be 10 nucleotides long + + align:start position:0% +tags have to be 10 nucleotides long + + + align:start position:0% +tags have to be 10 nucleotides long +okay a lot of fancy biochemistry here to + + align:start position:0% +okay a lot of fancy biochemistry here to + + + align:start position:0% +okay a lot of fancy biochemistry here to +get this to work right + + align:start position:0% +get this to work right + + + align:start position:0% +get this to work right +so you got a tag here and you got a tag + + align:start position:0% +so you got a tag here and you got a tag + + + align:start position:0% +so you got a tag here and you got a tag +here and you got a little adapter here + + align:start position:0% +here and you got a little adapter here + + + align:start position:0% +here and you got a little adapter here +that we've added on on this side + + align:start position:0% +that we've added on on this side + + + align:start position:0% +that we've added on on this side +and then finally what we're gonna do + + align:start position:0% +and then finally what we're gonna do + + + align:start position:0% +and then finally what we're gonna do +we've cut + + align:start position:0% +we've cut + + + align:start position:0% +we've cut +we've cut it here and we've cut it here + + align:start position:0% +we've cut it here and we've cut it here + + + align:start position:0% +we've cut it here and we've cut it here +what we can do is add something called a + + align:start position:0% +what we can do is add something called a + + + align:start position:0% +what we can do is add something called a +ligase that basically takes all blunt + + align:start position:0% +ligase that basically takes all blunt + + + align:start position:0% +ligase that basically takes all blunt +ends and just tries to make + + align:start position:0% +ends and just tries to make + + + align:start position:0% +ends and just tries to make +pairs together tries to bring any small + + align:start position:0% +pairs together tries to bring any small + + + align:start position:0% +pairs together tries to bring any small +strands of dna with blunt ends and tries + + align:start position:0% +strands of dna with blunt ends and tries + + + align:start position:0% +strands of dna with blunt ends and tries +to attach them together so we have a + + align:start position:0% +to attach them together so we have a + + + align:start position:0% +to attach them together so we have a +blunt end that was here and a blend end + + align:start position:0% +blunt end that was here and a blend end + + + align:start position:0% +blunt end that was here and a blend end +that was here here's the first tag and + + align:start position:0% +that was here here's the first tag and + + + align:start position:0% +that was here here's the first tag and +here's the second tag + + align:start position:0% +here's the second tag + + + align:start position:0% +here's the second tag +and we're going to have a whole bunch of + + align:start position:0% +and we're going to have a whole bunch of + + + align:start position:0% +and we're going to have a whole bunch of +these and what we can do is just run it + + align:start position:0% +these and what we can do is just run it + + + align:start position:0% +these and what we can do is just run it +through a sequencer basically okay we're + + align:start position:0% +through a sequencer basically okay we're + + + align:start position:0% +through a sequencer basically okay we're +going to do some more fancy footwork to + + align:start position:0% +going to do some more fancy footwork to + + + align:start position:0% +going to do some more fancy footwork to +get these to be as compact as possible + + align:start position:0% +get these to be as compact as possible + + + align:start position:0% +get these to be as compact as possible +and in the end we'll have one stretch of + + align:start position:0% +and in the end we'll have one stretch of + + + align:start position:0% +and in the end we'll have one stretch of +dna + + align:start position:0% +dna + + + align:start position:0% +dna +with just one tag after another with + + align:start position:0% +with just one tag after another with + + + align:start position:0% +with just one tag after another with +some capg's in the middle as spacers so + + align:start position:0% +some capg's in the middle as spacers so + + + align:start position:0% +some capg's in the middle as spacers so +we can make sure we're getting we're + + align:start position:0% +we can make sure we're getting we're + + + align:start position:0% +we can make sure we're getting we're +staying synchronized + + align:start position:0% +staying synchronized + + + align:start position:0% +staying synchronized +now what you do is you run this through + + align:start position:0% +now what you do is you run this through + + + align:start position:0% +now what you do is you run this through +an automated sequencer and then you can + + align:start position:0% +an automated sequencer and then you can + + + align:start position:0% +an automated sequencer and then you can +just get you can read off the sequence + + align:start position:0% +just get you can read off the sequence + + + align:start position:0% +just get you can read off the sequence +just like this + + align:start position:0% +just like this + + + align:start position:0% +just like this +one then the other than the one the + + align:start position:0% +one then the other than the one the + + + align:start position:0% +one then the other than the one the +other and then search databases + + align:start position:0% +other and then search databases + + + align:start position:0% +other and then search databases +to see what gene do we think this is + + align:start position:0% +to see what gene do we think this is + + + align:start position:0% +to see what gene do we think this is +now the reason why this is an absolute + + align:start position:0% +now the reason why this is an absolute + + + align:start position:0% +now the reason why this is an absolute +gene expression measurement for sure is + + align:start position:0% +gene expression measurement for sure is + + + align:start position:0% +gene expression measurement for sure is +that if this gene is overrepresented two + + align:start position:0% +that if this gene is overrepresented two + + + align:start position:0% +that if this gene is overrepresented two +times more than this one you're sure + + align:start position:0% +times more than this one you're sure + + + align:start position:0% +times more than this one you're sure +you're going to see two times more tags + + align:start position:0% +you're going to see two times more tags + + + align:start position:0% +you're going to see two times more tags +than this one in theory + + align:start position:0% +than this one in theory + + + align:start position:0% +than this one in theory +okay there are efficiencies to each one + + align:start position:0% +okay there are efficiencies to each one + + + align:start position:0% +okay there are efficiencies to each one +of these steps that we talked about and + + align:start position:0% +of these steps that we talked about and + + + align:start position:0% +of these steps that we talked about and +this is not as simple as a microarray + + align:start position:0% +this is not as simple as a microarray + + + align:start position:0% +this is not as simple as a microarray +right + + align:start position:0% +right + + + align:start position:0% +right +literally you can take the sample if + + align:start position:0% +literally you can take the sample if + + + align:start position:0% +literally you can take the sample if +you're a physician at brigham's house or + + align:start position:0% +you're a physician at brigham's house or + + + align:start position:0% +you're a physician at brigham's house or +any of these hospitals essentially take + + align:start position:0% +any of these hospitals essentially take + + + align:start position:0% +any of these hospitals essentially take +it to a core and get a microarray done + + align:start position:0% +it to a core and get a microarray done + + + align:start position:0% +it to a core and get a microarray done +sage is a lot more involved + + align:start position:0% +sage is a lot more involved + + + align:start position:0% +sage is a lot more involved +but in theory this is a great way to + + align:start position:0% +but in theory this is a great way to + + + align:start position:0% +but in theory this is a great way to +pick up low expression + + align:start position:0% +pick up low expression + + + align:start position:0% +pick up low expression +genes with very low expression levels + + align:start position:0% +genes with very low expression levels + + + align:start position:0% +genes with very low expression levels +okay so that's why it was worth at least + + align:start position:0% +okay so that's why it was worth at least + + + align:start position:0% +okay so that's why it was worth at least +talking about sage because if you're + + align:start position:0% +talking about sage because if you're + + + align:start position:0% +talking about sage because if you're +looking at absolute expression levels + + align:start position:0% +looking at absolute expression levels + + + align:start position:0% +looking at absolute expression levels +this is where it's going + + align:start position:0% +this is where it's going + + + align:start position:0% +this is where it's going +for now this is a back burner kind of + + align:start position:0% +for now this is a back burner kind of + + + align:start position:0% +for now this is a back burner kind of +technology people still use it they're + + align:start position:0% +technology people still use it they're + + + align:start position:0% +technology people still use it they're +people who are religiously devoted to it + + align:start position:0% +people who are religiously devoted to it + + + align:start position:0% +people who are religiously devoted to it +but most people you end up using + + align:start position:0% +but most people you end up using + + + align:start position:0% +but most people you end up using +microrace today + + align:start position:0% + + + + align:start position:0% + +the tag is just happens to be a sequence + + align:start position:0% +the tag is just happens to be a sequence + + + align:start position:0% +the tag is just happens to be a sequence +so what we're calling a tag here is + + align:start position:0% +so what we're calling a tag here is + + + align:start position:0% +so what we're calling a tag here is +nothing we put there okay okay it's + + align:start position:0% +nothing we put there okay okay it's + + + align:start position:0% +nothing we put there okay okay it's +something that is next to a catg that's + + align:start position:0% +something that is next to a catg that's + + + align:start position:0% +something that is next to a catg that's +on this end of the gene + + align:start position:0% +on this end of the gene + + + align:start position:0% +on this end of the gene +okay + + align:start position:0% +okay + + + align:start position:0% +okay +if there's nothing there like that then + + align:start position:0% +if there's nothing there like that then + + + align:start position:0% +if there's nothing there like that then +we're not gonna find it okay so that's + + align:start position:0% +we're not gonna find it okay so that's + + + align:start position:0% +we're not gonna find it okay so that's +another catch okay if the first one is + + align:start position:0% +another catch okay if the first one is + + + align:start position:0% +another catch okay if the first one is +all the way up here we might not even + + align:start position:0% +all the way up here we might not even + + + align:start position:0% +all the way up here we might not even +get it so they're saying the average + + align:start position:0% +get it so they're saying the average + + + align:start position:0% +get it so they're saying the average +if you do the math there's at least one + + align:start position:0% +if you do the math there's at least one + + + align:start position:0% +if you do the math there's at least one +of these within 256 base pairs right + + align:start position:0% +of these within 256 base pairs right + + + align:start position:0% +of these within 256 base pairs right +because it's like four to the fourth + + align:start position:0% +because it's like four to the fourth + + + align:start position:0% +because it's like four to the fourth +so there should be one there but there + + align:start position:0% +so there should be one there but there + + + align:start position:0% +so there should be one there but there +might be degeneracies where it might not + + align:start position:0% +might be degeneracies where it might not + + + align:start position:0% +might be degeneracies where it might not +be there + + align:start position:0% +be there + + + align:start position:0% +be there +so that's the whole technique it's 10 + + align:start position:0% +so that's the whole technique it's 10 + + + align:start position:0% +so that's the whole technique it's 10 +it's ctg only because of the + + align:start position:0% +it's ctg only because of the + + + align:start position:0% +it's ctg only because of the +peculiarities of the enzymes being used + + align:start position:0% +peculiarities of the enzymes being used + + + align:start position:0% +peculiarities of the enzymes being used +to actually cut these things apart and + + align:start position:0% +to actually cut these things apart and + + + align:start position:0% +to actually cut these things apart and +then just look at the tags + + align:start position:0% +then just look at the tags + + + align:start position:0% +then just look at the tags +any questions about that + + align:start position:0% +any questions about that + + + align:start position:0% +any questions about that +so that's basically that was the last + + align:start position:0% +so that's basically that was the last + + + align:start position:0% +so that's basically that was the last +thing i want to talk about in this + + align:start position:0% +thing i want to talk about in this + + + align:start position:0% +thing i want to talk about in this +section of uh gene measurement + + align:start position:0% +section of uh gene measurement + + + align:start position:0% +section of uh gene measurement +technologies or gene measurement + + align:start position:0% +technologies or gene measurement + + + align:start position:0% +technologies or gene measurement +techniques + + align:start position:0% +techniques + + + align:start position:0% +techniques +so now zach was suggesting that i talk + + align:start position:0% +so now zach was suggesting that i talk + + + align:start position:0% +so now zach was suggesting that i talk +about uh + + align:start position:0% +about uh + + + align:start position:0% +about uh +some of the stuff that we've been doing + + align:start position:0% +some of the stuff that we've been doing + + + align:start position:0% +some of the stuff that we've been doing +with diabetes only because this is + + align:start position:0% +with diabetes only because this is + + + align:start position:0% +with diabetes only because this is +supposed to be genomic medicine + + align:start position:0% +supposed to be genomic medicine + + + align:start position:0% +supposed to be genomic medicine +we can give you a real world example of + + align:start position:0% +we can give you a real world example of + + + align:start position:0% +we can give you a real world example of +how we've used microarrays to help us + + align:start position:0% +how we've used microarrays to help us + + + align:start position:0% +how we've used microarrays to help us +with diabetes + + align:start position:0% + + + + align:start position:0% + +so i'm a pediatric endocrinologist i + + align:start position:0% +so i'm a pediatric endocrinologist i + + + align:start position:0% +so i'm a pediatric endocrinologist i +spent most of my time over at the joslin + + align:start position:0% +spent most of my time over at the joslin + + + align:start position:0% +spent most of my time over at the joslin +diabetes center studying type 2 diabetes + + align:start position:0% +diabetes center studying type 2 diabetes + + + align:start position:0% +diabetes center studying type 2 diabetes +currently affects about 15 million + + align:start position:0% +currently affects about 15 million + + + align:start position:0% +currently affects about 15 million +people in the united states and in fact + + align:start position:0% +people in the united states and in fact + + + align:start position:0% +people in the united states and in fact +the cdc just estimated a couple months + + align:start position:0% +the cdc just estimated a couple months + + + align:start position:0% +the cdc just estimated a couple months +ago that a child born in the year 2000 + + align:start position:0% +ago that a child born in the year 2000 + + + align:start position:0% +ago that a child born in the year 2000 +now has a 1-3 risk of getting type 2 + + align:start position:0% +now has a 1-3 risk of getting type 2 + + + align:start position:0% +now has a 1-3 risk of getting type 2 +diabetes okay so it's 33 likelihood now + + align:start position:0% +diabetes okay so it's 33 likelihood now + + + align:start position:0% +diabetes okay so it's 33 likelihood now +of a child born just two years ago to + + align:start position:0% +of a child born just two years ago to + + + align:start position:0% +of a child born just two years ago to +get type 2 diabetes why because of the + + align:start position:0% +get type 2 diabetes why because of the + + + align:start position:0% +get type 2 diabetes why because of the +obesity problem okay so we all know kids + + align:start position:0% +obesity problem okay so we all know kids + + + align:start position:0% +obesity problem okay so we all know kids +the kids have less exercise today in + + align:start position:0% +the kids have less exercise today in + + + align:start position:0% +the kids have less exercise today in +school because they have to pass these + + align:start position:0% +school because they have to pass these + + + align:start position:0% +school because they have to pass these +tests and now schools have to give more + + align:start position:0% +tests and now schools have to give more + + + align:start position:0% +tests and now schools have to give more +courses so that they pass the m cases + + align:start position:0% +courses so that they pass the m cases + + + align:start position:0% +courses so that they pass the m cases +and things like that there's more tv + + align:start position:0% +and things like that there's more tv + + + align:start position:0% +and things like that there's more tv +there's more channels there's internet + + align:start position:0% +there's more channels there's internet + + + align:start position:0% +there's more channels there's internet +there's all these things that cause kids + + align:start position:0% +there's all these things that cause kids + + + align:start position:0% +there's all these things that cause kids +to basically sit in one place they don't + + align:start position:0% +to basically sit in one place they don't + + + align:start position:0% +to basically sit in one place they don't +get much exercise i think there was + + align:start position:0% +get much exercise i think there was + + + align:start position:0% +get much exercise i think there was +something on cnn last week about how + + align:start position:0% +something on cnn last week about how + + + align:start position:0% +something on cnn last week about how +even toddlers one or two years or just + + align:start position:0% +even toddlers one or two years or just + + + align:start position:0% +even toddlers one or two years or just +not getting as much exercise as they + + align:start position:0% +not getting as much exercise as they + + + align:start position:0% +not getting as much exercise as they +used to okay so this isn't even school + + align:start position:0% +used to okay so this isn't even school + + + align:start position:0% +used to okay so this isn't even school +age this is starting at basically age + + align:start position:0% +age this is starting at basically age + + + align:start position:0% +age this is starting at basically age +one or two + + align:start position:0% +one or two + + + align:start position:0% +one or two +so question we had here was this okay we + + align:start position:0% +so question we had here was this okay we + + + align:start position:0% +so question we had here was this okay we +know how to define i mean the diagnosis + + align:start position:0% +know how to define i mean the diagnosis + + + align:start position:0% +know how to define i mean the diagnosis +of diabetes is actually sort of + + align:start position:0% +of diabetes is actually sort of + + + align:start position:0% +of diabetes is actually sort of +arbitrary okay in fact the definition of + + align:start position:0% +arbitrary okay in fact the definition of + + + align:start position:0% +arbitrary okay in fact the definition of +diabetes keeps changing it turns out but + + align:start position:0% +diabetes keeps changing it turns out but + + + align:start position:0% +diabetes keeps changing it turns out but +for example at one point the definition + + align:start position:0% +for example at one point the definition + + + align:start position:0% +for example at one point the definition +of diabetes was having a fasting blood + + align:start position:0% +of diabetes was having a fasting blood + + + align:start position:0% +of diabetes was having a fasting blood +sugar so morning blood sugar greater + + align:start position:0% +sugar so morning blood sugar greater + + + align:start position:0% +sugar so morning blood sugar greater +than 127 i think it was milligrams per + + align:start position:0% +than 127 i think it was milligrams per + + + align:start position:0% +than 127 i think it was milligrams per +deciliter qualified you for having + + align:start position:0% +deciliter qualified you for having + + + align:start position:0% +deciliter qualified you for having +diabetes + + align:start position:0% +diabetes + + + align:start position:0% +diabetes +but what we know is that it's not just + + align:start position:0% +but what we know is that it's not just + + + align:start position:0% +but what we know is that it's not just +an on and off type of thing like you all + + align:start position:0% +an on and off type of thing like you all + + + align:start position:0% +an on and off type of thing like you all +of a sudden you don't have diabetes and + + align:start position:0% +of a sudden you don't have diabetes and + + + align:start position:0% +of a sudden you don't have diabetes and +now all of a sudden you do + + align:start position:0% +now all of a sudden you do + + + align:start position:0% +now all of a sudden you do +because diabetes is a very heritable + + align:start position:0% +because diabetes is a very heritable + + + align:start position:0% +because diabetes is a very heritable +trait okay + + align:start position:0% +trait okay + + + align:start position:0% +trait okay +it's controversial but some people say + + align:start position:0% +it's controversial but some people say + + + align:start position:0% +it's controversial but some people say +for example it's a very genetic trait + + align:start position:0% +for example it's a very genetic trait + + + align:start position:0% +for example it's a very genetic trait +let's put it that way + + align:start position:0% +let's put it that way + + + align:start position:0% +let's put it that way +there are some studies that show that in + + align:start position:0% +there are some studies that show that in + + + align:start position:0% +there are some studies that show that in +twin twin studies okay if you have one + + align:start position:0% +twin twin studies okay if you have one + + + align:start position:0% +twin twin studies okay if you have one +twin that has type 2 diabetes you have a + + align:start position:0% +twin that has type 2 diabetes you have a + + + align:start position:0% +twin that has type 2 diabetes you have a +98 likelihood that the other twins gonna + + align:start position:0% +98 likelihood that the other twins gonna + + + align:start position:0% +98 likelihood that the other twins gonna +get it if they don't already have it + + align:start position:0% +get it if they don't already have it + + + align:start position:0% +get it if they don't already have it +okay so it makes you think that it's + + align:start position:0% +okay so it makes you think that it's + + + align:start position:0% +okay so it makes you think that it's +incredibly genetic but the problem is + + align:start position:0% +incredibly genetic but the problem is + + + align:start position:0% +incredibly genetic but the problem is +the incidence is so high this is a + + align:start position:0% +the incidence is so high this is a + + + align:start position:0% +the incidence is so high this is a +common disease it's not very easy at all + + align:start position:0% +common disease it's not very easy at all + + + align:start position:0% +common disease it's not very easy at all +to find a particular mutation that + + align:start position:0% +to find a particular mutation that + + + align:start position:0% +to find a particular mutation that +causes this we haven't been that lucky + + align:start position:0% +causes this we haven't been that lucky + + + align:start position:0% +causes this we haven't been that lucky +so far + + align:start position:0% +so far + + + align:start position:0% +so far +we have found the field has found a + + align:start position:0% +we have found the field has found a + + + align:start position:0% +we have found the field has found a +number of mutations that do lead to + + align:start position:0% +number of mutations that do lead to + + + align:start position:0% +number of mutations that do lead to +diabetes but they might explain + + align:start position:0% +diabetes but they might explain + + + align:start position:0% +diabetes but they might explain +the sum total of maybe 0.01 of the + + align:start position:0% +the sum total of maybe 0.01 of the + + + align:start position:0% +the sum total of maybe 0.01 of the +people who have diabetes those are very + + align:start position:0% +people who have diabetes those are very + + + align:start position:0% +people who have diabetes those are very +rare forms the common form which seems + + align:start position:0% +rare forms the common form which seems + + + align:start position:0% +rare forms the common form which seems +like it's incredibly genetic is still a + + align:start position:0% +like it's incredibly genetic is still a + + + align:start position:0% +like it's incredibly genetic is still a +big mystery + + align:start position:0% +big mystery + + + align:start position:0% +big mystery +the point of what we were going to use + + align:start position:0% +the point of what we were going to use + + + align:start position:0% +the point of what we were going to use +genomic medicine for here was trying to + + align:start position:0% +genomic medicine for here was trying to + + + align:start position:0% +genomic medicine for here was trying to +define the patterns of how people might + + align:start position:0% +define the patterns of how people might + + + align:start position:0% +define the patterns of how people might +go from non-diabetes to diabetes there's + + align:start position:0% +go from non-diabetes to diabetes there's + + + align:start position:0% +go from non-diabetes to diabetes there's +a middle group in there okay in fact the + + align:start position:0% +a middle group in there okay in fact the + + + align:start position:0% +a middle group in there okay in fact the +ada the diabetes association now calls + + align:start position:0% +ada the diabetes association now calls + + + align:start position:0% +ada the diabetes association now calls +us pre-diabetes people who don't have a + + align:start position:0% +us pre-diabetes people who don't have a + + + align:start position:0% +us pre-diabetes people who don't have a +normal handling of sugar + + align:start position:0% +normal handling of sugar + + + align:start position:0% +normal handling of sugar +but don't strictly meet the criteria for + + align:start position:0% +but don't strictly meet the criteria for + + + align:start position:0% +but don't strictly meet the criteria for +diabetes today + + align:start position:0% +diabetes today + + + align:start position:0% +diabetes today +so question we had here + + align:start position:0% +so question we had here + + + align:start position:0% +so question we had here +using microarrays can we define patterns + + align:start position:0% +using microarrays can we define patterns + + + align:start position:0% +using microarrays can we define patterns +of gene expression in human subjects + + align:start position:0% +of gene expression in human subjects + + + align:start position:0% +of gene expression in human subjects +with diabetes specifically in their + + align:start position:0% +with diabetes specifically in their + + + align:start position:0% +with diabetes specifically in their +muscle samples + + align:start position:0% +muscle samples + + + align:start position:0% +muscle samples +to identify those that are at higher + + align:start position:0% +to identify those that are at higher + + + align:start position:0% +to identify those that are at higher +not just + + align:start position:0% +not just + + + align:start position:0% +not just +define what genes are different between + + align:start position:0% +define what genes are different between + + + align:start position:0% +define what genes are different between +diabetes and non-diabetes but also what + + align:start position:0% +diabetes and non-diabetes but also what + + + align:start position:0% +diabetes and non-diabetes but also what +genes were also different already + + align:start position:0% +genes were also different already + + + align:start position:0% +genes were also different already +different in those that were at high + + align:start position:0% +different in those that were at high + + + align:start position:0% +different in those that were at high +risk of getting diabetes specifically + + align:start position:0% +risk of getting diabetes specifically + + + align:start position:0% +risk of getting diabetes specifically +these are offspring of type 2 diabetics + + align:start position:0% +these are offspring of type 2 diabetics + + + align:start position:0% +these are offspring of type 2 diabetics +so this particular study that we did was + + align:start position:0% +so this particular study that we did was + + + align:start position:0% +so this particular study that we did was +in mexican-american subjects we have + + align:start position:0% +in mexican-american subjects we have + + + align:start position:0% +in mexican-american subjects we have +diabetes and family history of diabetes + + align:start position:0% +diabetes and family history of diabetes + + + align:start position:0% +diabetes and family history of diabetes +so we basically have three groups family + + align:start position:0% +so we basically have three groups family + + + align:start position:0% +so we basically have three groups family +history negative + + align:start position:0% +history negative + + + align:start position:0% +history negative +diabetes that's what obviously these are + + align:start position:0% +diabetes that's what obviously these are + + + align:start position:0% +diabetes that's what obviously these are +control and then we have family history + + align:start position:0% +control and then we have family history + + + align:start position:0% +control and then we have family history +positive okay so we've got three groups + + align:start position:0% +positive okay so we've got three groups + + + align:start position:0% +positive okay so we've got three groups +here + + align:start position:0% +here + + + align:start position:0% +here +and you can look at the + + align:start position:0% +and you can look at the + + + align:start position:0% +and you can look at the +the subjects uh that we use for this + + align:start position:0% +the subjects uh that we use for this + + + align:start position:0% +the subjects uh that we use for this +particular study we had one that we used + + align:start position:0% +particular study we had one that we used + + + align:start position:0% +particular study we had one that we used +that we used for the arrays and we had + + align:start position:0% +that we used for the arrays and we had + + + align:start position:0% +that we used for the arrays and we had +another that we actually did validation + + align:start position:0% +another that we actually did validation + + + align:start position:0% +another that we actually did validation +were on some of the hypotheses that we + + align:start position:0% +were on some of the hypotheses that we + + + align:start position:0% +were on some of the hypotheses that we +came up with + + align:start position:0% +came up with + + + align:start position:0% +came up with +and so most of these characteristics are + + align:start position:0% +and so most of these characteristics are + + + align:start position:0% +and so most of these characteristics are +not different but they are different in + + align:start position:0% +not different but they are different in + + + align:start position:0% +not different but they are different in +a number of important ways so fasting + + align:start position:0% +a number of important ways so fasting + + + align:start position:0% +a number of important ways so fasting +glucose + + align:start position:0% +glucose + + + align:start position:0% +glucose +is 99 92 but 200 in the diabetics + + align:start position:0% +is 99 92 but 200 in the diabetics + + + align:start position:0% +is 99 92 but 200 in the diabetics +obviously because they have diabetes + + align:start position:0% +obviously because they have diabetes + + + align:start position:0% +obviously because they have diabetes +the two hour glucose was higher in the + + align:start position:0% +the two hour glucose was higher in the + + + align:start position:0% +the two hour glucose was higher in the +diet in the diabetics but the hemoglobin + + align:start position:0% +diet in the diabetics but the hemoglobin + + + align:start position:0% +diet in the diabetics but the hemoglobin +a1c was already high in the family + + align:start position:0% +a1c was already high in the family + + + align:start position:0% +a1c was already high in the family +history positives what is the hemoglobin + + align:start position:0% +history positives what is the hemoglobin + + + align:start position:0% +history positives what is the hemoglobin +a1c + + align:start position:0% +a1c + + + align:start position:0% +a1c +well that's one of our measurements for + + align:start position:0% +well that's one of our measurements for + + + align:start position:0% +well that's one of our measurements for +how high the blood sugar levels are over + + align:start position:0% +how high the blood sugar levels are over + + + align:start position:0% +how high the blood sugar levels are over +a span of 120 days okay so in fact most + + align:start position:0% +a span of 120 days okay so in fact most + + + align:start position:0% +a span of 120 days okay so in fact most +uh physicians now who take care of + + align:start position:0% +uh physicians now who take care of + + + align:start position:0% +uh physicians now who take care of +patients with diabetes we measure this + + align:start position:0% +patients with diabetes we measure this + + + align:start position:0% +patients with diabetes we measure this +hemoglobin a1c + + align:start position:0% +hemoglobin a1c + + + align:start position:0% +hemoglobin a1c +at least four times a year so that we + + align:start position:0% +at least four times a year so that we + + + align:start position:0% +at least four times a year so that we +can get a gauge as to what the blood + + align:start position:0% +can get a gauge as to what the blood + + + align:start position:0% +can get a gauge as to what the blood +sugars are like over the past 120 days + + align:start position:0% +sugars are like over the past 120 days + + + align:start position:0% +sugars are like over the past 120 days +because that's the lifespan of an + + align:start position:0% +because that's the lifespan of an + + + align:start position:0% +because that's the lifespan of an +erythrocyte for a red cell and as the + + align:start position:0% +erythrocyte for a red cell and as the + + + align:start position:0% +erythrocyte for a red cell and as the +glucose levels are higher in the blood + + align:start position:0% +glucose levels are higher in the blood + + + align:start position:0% +glucose levels are higher in the blood +that actually glycosylates the + + align:start position:0% +that actually glycosylates the + + + align:start position:0% +that actually glycosylates the +hemoglobin in the red cell so it's a + + align:start position:0% +hemoglobin in the red cell so it's a + + + align:start position:0% +hemoglobin in the red cell so it's a +byproduct of this + + align:start position:0% +byproduct of this + + + align:start position:0% +byproduct of this +but it's already high in the family + + align:start position:0% +but it's already high in the family + + + align:start position:0% +but it's already high in the family +history positive they're not exactly + + align:start position:0% +history positive they're not exactly + + + align:start position:0% +history positive they're not exactly +like the family history negatives here + + align:start position:0% +like the family history negatives here + + + align:start position:0% +like the family history negatives here +okay + + align:start position:0% +okay + + + align:start position:0% +okay +fasting insulin already high okay so the + + align:start position:0% +fasting insulin already high okay so the + + + align:start position:0% +fasting insulin already high okay so the +problem with type 2 diabetes just to + + align:start position:0% +problem with type 2 diabetes just to + + + align:start position:0% +problem with type 2 diabetes just to +make sure everyone's on the same page + + align:start position:0% +make sure everyone's on the same page + + + align:start position:0% +make sure everyone's on the same page +here it's not a problem with making the + + align:start position:0% +here it's not a problem with making the + + + align:start position:0% +here it's not a problem with making the +insulin from the pancreas the problem is + + align:start position:0% +insulin from the pancreas the problem is + + + align:start position:0% +insulin from the pancreas the problem is +that insulin is there it just doesn't + + align:start position:0% +that insulin is there it just doesn't + + + align:start position:0% +that insulin is there it just doesn't +act like it's supposed to in the target + + align:start position:0% +act like it's supposed to in the target + + + align:start position:0% +act like it's supposed to in the target +tissues + + align:start position:0% +tissues + + + align:start position:0% +tissues +okay now to use my analogy from last + + align:start position:0% +okay now to use my analogy from last + + + align:start position:0% +okay now to use my analogy from last +week i just had this great food from the + + align:start position:0% +week i just had this great food from the + + + align:start position:0% +week i just had this great food from the +chinese truck again okay + + align:start position:0% +chinese truck again okay + + + align:start position:0% +chinese truck again okay +my glucose levels are going up my + + align:start position:0% +my glucose levels are going up my + + + align:start position:0% +my glucose levels are going up my +insulin levels are going up and so + + align:start position:0% +insulin levels are going up and so + + + align:start position:0% +insulin levels are going up and so +insulin is now telling number of my + + align:start position:0% +insulin is now telling number of my + + + align:start position:0% +insulin is now telling number of my +tissues to do a number of things it's + + align:start position:0% +tissues to do a number of things it's + + + align:start position:0% +tissues to do a number of things it's +telling my liver to stop making sugar + + align:start position:0% +telling my liver to stop making sugar + + + align:start position:0% +telling my liver to stop making sugar +okay i just ate a whole huge meal i + + align:start position:0% +okay i just ate a whole huge meal i + + + align:start position:0% +okay i just ate a whole huge meal i +don't need the liver to start making + + align:start position:0% +don't need the liver to start making + + + align:start position:0% +don't need the liver to start making +more sugar because i just ate a whole + + align:start position:0% +more sugar because i just ate a whole + + + align:start position:0% +more sugar because i just ate a whole +bunch but more importantly it's telling + + align:start position:0% +bunch but more importantly it's telling + + + align:start position:0% +bunch but more importantly it's telling +that my muscle and my fat cells to start + + align:start position:0% +that my muscle and my fat cells to start + + + align:start position:0% +that my muscle and my fat cells to start +taking in the sugar + + align:start position:0% +taking in the sugar + + + align:start position:0% +taking in the sugar +okay and what happens with type 2 + + align:start position:0% +okay and what happens with type 2 + + + align:start position:0% +okay and what happens with type 2 +diabetes is that that signal from the + + align:start position:0% +diabetes is that that signal from the + + + align:start position:0% +diabetes is that that signal from the +insulin to what the tissues are supposed + + align:start position:0% +insulin to what the tissues are supposed + + + align:start position:0% +insulin to what the tissues are supposed +to do is muted for some some reason we + + align:start position:0% +to do is muted for some some reason we + + + align:start position:0% +to do is muted for some some reason we +just don't know exactly why + + align:start position:0% +just don't know exactly why + + + align:start position:0% +just don't know exactly why +but that's the problem insulin is there + + align:start position:0% +but that's the problem insulin is there + + + align:start position:0% +but that's the problem insulin is there +in fact now these guys have a higher + + align:start position:0% +in fact now these guys have a higher + + + align:start position:0% +in fact now these guys have a higher +insulin level because already their + + align:start position:0% +insulin level because already their + + + align:start position:0% +insulin level because already their +bodies are realizing + + align:start position:0% +bodies are realizing + + + align:start position:0% +bodies are realizing +the same amount of insulin isn't doing + + align:start position:0% +the same amount of insulin isn't doing + + + align:start position:0% +the same amount of insulin isn't doing +what it's supposed to okay so pancreas + + align:start position:0% +what it's supposed to okay so pancreas + + + align:start position:0% +what it's supposed to okay so pancreas +sees that the sugar levels are not going + + align:start position:0% +sees that the sugar levels are not going + + + align:start position:0% +sees that the sugar levels are not going +down after the meals for example and + + align:start position:0% +down after the meals for example and + + + align:start position:0% +down after the meals for example and +it's saying oh i need to ramp up the + + align:start position:0% +it's saying oh i need to ramp up the + + + align:start position:0% +it's saying oh i need to ramp up the +amount of insulin i'm making + + align:start position:0% +amount of insulin i'm making + + + align:start position:0% +amount of insulin i'm making +but the primary problem is felt to be in + + align:start position:0% +but the primary problem is felt to be in + + + align:start position:0% +but the primary problem is felt to be in +the target tissues insulin resistance + + align:start position:0% +the target tissues insulin resistance + + + align:start position:0% +the target tissues insulin resistance +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so the group's already different and + + align:start position:0% +so the group's already different and + + + align:start position:0% +so the group's already different and +that's going to actually make this com + + align:start position:0% +that's going to actually make this com + + + align:start position:0% +that's going to actually make this com +analysis sort of complicated + + align:start position:0% +analysis sort of complicated + + + align:start position:0% +analysis sort of complicated +so we have five diabetics there + + align:start position:0% +so we have five diabetics there + + + align:start position:0% +so we have five diabetics there +four without diabetes with the family + + align:start position:0% +four without diabetes with the family + + + align:start position:0% +four without diabetes with the family +history of diabetes and six controls + + align:start position:0% +history of diabetes and six controls + + + align:start position:0% +history of diabetes and six controls +here + + align:start position:0% +here + + + align:start position:0% +here +and when you do this you can compare + + align:start position:0% +and when you do this you can compare + + + align:start position:0% +and when you do this you can compare +each group to each other group so we can + + align:start position:0% +each group to each other group so we can + + + align:start position:0% +each group to each other group so we can +we took muscle samples from these + + align:start position:0% +we took muscle samples from these + + + align:start position:0% +we took muscle samples from these +individuals uh if they were on medicines + + align:start position:0% +individuals uh if they were on medicines + + + align:start position:0% +individuals uh if they were on medicines +for the diabetics they were actually + + align:start position:0% +for the diabetics they were actually + + + align:start position:0% +for the diabetics they were actually +taken off for a number of days they had + + align:start position:0% +taken off for a number of days they had + + + align:start position:0% +taken off for a number of days they had +no strenuous exercise beforehand + + align:start position:0% +no strenuous exercise beforehand + + + align:start position:0% +no strenuous exercise beforehand +and it's all informed consent and you + + align:start position:0% +and it's all informed consent and you + + + align:start position:0% +and it's all informed consent and you +get the + + align:start position:0% +get the + + + align:start position:0% +get the +muscle samples you extract out the rna + + align:start position:0% +muscle samples you extract out the rna + + + align:start position:0% +muscle samples you extract out the rna +we put them on these microarrays the + + align:start position:0% +we put them on these microarrays the + + + align:start position:0% +we put them on these microarrays the +microwaves at this when we did these + + align:start position:0% +microwaves at this when we did these + + + align:start position:0% +microwaves at this when we did these +experiments measured about 7000 genes + + align:start position:0% +experiments measured about 7000 genes + + + align:start position:0% +experiments measured about 7000 genes +today when you do this for the same + + align:start position:0% +today when you do this for the same + + + align:start position:0% +today when you do this for the same +price you get 44 000 genes okay + + align:start position:0% +price you get 44 000 genes okay + + + align:start position:0% +price you get 44 000 genes okay +and so + + align:start position:0% +and so + + + align:start position:0% +and so +we can use a number of different + + align:start position:0% +we can use a number of different + + + align:start position:0% +we can use a number of different +analytic techniques that you're going to + + align:start position:0% +analytic techniques that you're going to + + + align:start position:0% +analytic techniques that you're going to +be learning about over the next over the + + align:start position:0% +be learning about over the next over the + + + align:start position:0% +be learning about over the next over the +rest of the semester exactly how we make + + align:start position:0% +rest of the semester exactly how we make + + + align:start position:0% +rest of the semester exactly how we make +the distinction of which genes might be + + align:start position:0% +the distinction of which genes might be + + + align:start position:0% +the distinction of which genes might be +different what genes are not changing + + align:start position:0% +different what genes are not changing + + + align:start position:0% +different what genes are not changing +but if you compare family history + + align:start position:0% +but if you compare family history + + + align:start position:0% +but if you compare family history +negative to diabetes we found 187 genes + + align:start position:0% +negative to diabetes we found 187 genes + + + align:start position:0% +negative to diabetes we found 187 genes +that are different even if even if you + + align:start position:0% +that are different even if even if you + + + align:start position:0% +that are different even if even if you +compare family history positive to + + align:start position:0% +compare family history positive to + + + align:start position:0% +compare family history positive to +diabetes is 166 genes that are different + + align:start position:0% +diabetes is 166 genes that are different + + + align:start position:0% +diabetes is 166 genes that are different +so fewer and there's some overlap so 55 + + align:start position:0% +so fewer and there's some overlap so 55 + + + align:start position:0% +so fewer and there's some overlap so 55 +genes between there are 55 genes that + + align:start position:0% +genes between there are 55 genes that + + + align:start position:0% +genes between there are 55 genes that +were in this list added this list + + align:start position:0% +were in this list added this list + + + align:start position:0% +were in this list added this list +and most of them coded for all sorts of + + align:start position:0% +and most of them coded for all sorts of + + + align:start position:0% +and most of them coded for all sorts of +interesting proteins okay for example + + align:start position:0% +interesting proteins okay for example + + + align:start position:0% +interesting proteins okay for example +mitochondrial proteins that are involved + + align:start position:0% +mitochondrial proteins that are involved + + + align:start position:0% +mitochondrial proteins that are involved +in actually energy metabolism or uh atp + + align:start position:0% +in actually energy metabolism or uh atp + + + align:start position:0% +in actually energy metabolism or uh atp +synthesis oxidative phosphorylation + + align:start position:0% +synthesis oxidative phosphorylation + + + align:start position:0% +synthesis oxidative phosphorylation +which we'll talk about in a moment + + align:start position:0% +which we'll talk about in a moment + + + align:start position:0% +which we'll talk about in a moment +and so this is one common way of how we + + align:start position:0% +and so this is one common way of how we + + + align:start position:0% +and so this is one common way of how we +actually like to look at these genes + + align:start position:0% +actually like to look at these genes + + + align:start position:0% +actually like to look at these genes +okay it's called a heat map or even a + + align:start position:0% +okay it's called a heat map or even a + + + align:start position:0% +okay it's called a heat map or even a +dendrogram depending on + + align:start position:0% +dendrogram depending on + + + align:start position:0% +dendrogram depending on +the different programs that you use but + + align:start position:0% +the different programs that you use but + + + align:start position:0% +the different programs that you use but +the green indicates so each of the rows + + align:start position:0% +the green indicates so each of the rows + + + align:start position:0% +the green indicates so each of the rows +indicates a gene each of the columns + + align:start position:0% +indicates a gene each of the columns + + + align:start position:0% +indicates a gene each of the columns +typically represents a sample and the + + align:start position:0% +typically represents a sample and the + + + align:start position:0% +typically represents a sample and the +green indicates a gene that's higher + + align:start position:0% +green indicates a gene that's higher + + + align:start position:0% +green indicates a gene that's higher +than the mean + + align:start position:0% +than the mean + + + align:start position:0% +than the mean +and the red indicates a gene that's + + align:start position:0% +and the red indicates a gene that's + + + align:start position:0% +and the red indicates a gene that's +lower than the mean + + align:start position:0% +lower than the mean + + + align:start position:0% +lower than the mean +and what we're showing here are + + align:start position:0% +and what we're showing here are + + + align:start position:0% +and what we're showing here are +a subset of those 55 genes that actually + + align:start position:0% +a subset of those 55 genes that actually + + + align:start position:0% +a subset of those 55 genes that actually +have something to do with energy + + align:start position:0% +have something to do with energy + + + align:start position:0% +have something to do with energy +metabolism + + align:start position:0% +metabolism + + + align:start position:0% +metabolism +and primarily most of the genes that + + align:start position:0% +and primarily most of the genes that + + + align:start position:0% +and primarily most of the genes that +have something to do with energy + + align:start position:0% +have something to do with energy + + + align:start position:0% +have something to do with energy +metabolism are higher in the family + + align:start position:0% +metabolism are higher in the family + + + align:start position:0% +metabolism are higher in the family +history negative they're lower in the + + align:start position:0% +history negative they're lower in the + + + align:start position:0% +history negative they're lower in the +diabetics and they're already low in the + + align:start position:0% +diabetics and they're already low in the + + + align:start position:0% +diabetics and they're already low in the +family history positive so the ones that + + align:start position:0% +family history positive so the ones that + + + align:start position:0% +family history positive so the ones that +are at risk for getting diabetes + + align:start position:0% + + + + align:start position:0% + +so now we've got a piece of this puzzle + + align:start position:0% +so now we've got a piece of this puzzle + + + align:start position:0% +so now we've got a piece of this puzzle +we see that transcription of some of + + align:start position:0% +we see that transcription of some of + + + align:start position:0% +we see that transcription of some of +these mitochondrial genes metabolic + + align:start position:0% +these mitochondrial genes metabolic + + + align:start position:0% +these mitochondrial genes metabolic +related genes are is down + + align:start position:0% +related genes are is down + + + align:start position:0% +related genes are is down +that might be causing decreased + + align:start position:0% +that might be causing decreased + + + align:start position:0% +that might be causing decreased +oxidative phosphorylation so what + + align:start position:0% +oxidative phosphorylation so what + + + align:start position:0% +oxidative phosphorylation so what +happens is fat might fat is building up + + align:start position:0% +happens is fat might fat is building up + + + align:start position:0% +happens is fat might fat is building up +in the muscle and the fat cells and if + + align:start position:0% +in the muscle and the fat cells and if + + + align:start position:0% +in the muscle and the fat cells and if +you have less of these genes and + + align:start position:0% +you have less of these genes and + + + align:start position:0% +you have less of these genes and +presumably less of the proteins that + + align:start position:0% +presumably less of the proteins that + + + align:start position:0% +presumably less of the proteins that +we're using them as a proxy for we're + + align:start position:0% +we're using them as a proxy for we're + + + align:start position:0% +we're using them as a proxy for we're +getting decreased lipid oxidation + + align:start position:0% +getting decreased lipid oxidation + + + align:start position:0% +getting decreased lipid oxidation +as fat or lipid builds up in muscle it + + align:start position:0% +as fat or lipid builds up in muscle it + + + align:start position:0% +as fat or lipid builds up in muscle it +actually can cause the insulin to not + + align:start position:0% +actually can cause the insulin to not + + + align:start position:0% +actually can cause the insulin to not +work as well so maybe that's how we're + + align:start position:0% +work as well so maybe that's how we're + + + align:start position:0% +work as well so maybe that's how we're +getting to insulin resistance because of + + align:start position:0% +getting to insulin resistance because of + + + align:start position:0% +getting to insulin resistance because of +the increase in the lipid in the muscle + + align:start position:0% +the increase in the lipid in the muscle + + + align:start position:0% +the increase in the lipid in the muscle +well there's a huge half of this that's + + align:start position:0% +well there's a huge half of this that's + + + align:start position:0% +well there's a huge half of this that's +still unknown today okay and that's + + align:start position:0% +still unknown today okay and that's + + + align:start position:0% +still unknown today okay and that's +that's the part i want to focus on for a + + align:start position:0% +that's the part i want to focus on for a + + + align:start position:0% +that's the part i want to focus on for a +second + + align:start position:0% +second + + + align:start position:0% +second +okay people show this slide all the time + + align:start position:0% +okay people show this slide all the time + + + align:start position:0% +okay people show this slide all the time +in all sorts of different contexts right + + align:start position:0% +in all sorts of different contexts right + + + align:start position:0% +in all sorts of different contexts right +huge formula here huge formula here the + + align:start position:0% +huge formula here huge formula here the + + + align:start position:0% +huge formula here huge formula here the +miracle occurs in the middle right + + align:start position:0% +miracle occurs in the middle right + + + align:start position:0% +miracle occurs in the middle right +and still the biggest problem with this + + align:start position:0% +and still the biggest problem with this + + + align:start position:0% +and still the biggest problem with this +type of study + + align:start position:0% +type of study + + + align:start position:0% +type of study +is that this miracle still has to occur + + align:start position:0% +is that this miracle still has to occur + + + align:start position:0% +is that this miracle still has to occur +to figure out why + + align:start position:0% +to figure out why + + + align:start position:0% +to figure out why +do we have this list of genes okay what + + align:start position:0% +do we have this list of genes okay what + + + align:start position:0% +do we have this list of genes okay what +is it about this list of genes that's + + align:start position:0% +is it about this list of genes that's + + + align:start position:0% +is it about this list of genes that's +special + + align:start position:0% +special + + + align:start position:0% +special +right how are we getting to this set of + + align:start position:0% +right how are we getting to this set of + + + align:start position:0% +right how are we getting to this set of +genes + + align:start position:0% +genes + + + align:start position:0% +genes +what's the biology behind it + + align:start position:0% +what's the biology behind it + + + align:start position:0% +what's the biology behind it +so although many of my colleagues will + + align:start position:0% +so although many of my colleagues will + + + align:start position:0% +so although many of my colleagues will +argue with me about this you cannot + + align:start position:0% +argue with me about this you cannot + + + align:start position:0% +argue with me about this you cannot +ignore the biology here okay + + align:start position:0% +ignore the biology here okay + + + align:start position:0% +ignore the biology here okay +it's getting harder and harder to just + + align:start position:0% +it's getting harder and harder to just + + + align:start position:0% +it's getting harder and harder to just +say here's my list of genes go run with + + align:start position:0% +say here's my list of genes go run with + + + align:start position:0% +say here's my list of genes go run with +this okay you need to know what is it + + align:start position:0% +this okay you need to know what is it + + + align:start position:0% +this okay you need to know what is it +about this list what's causing this list + + align:start position:0% +about this list what's causing this list + + + align:start position:0% +about this list what's causing this list +of genes to be so special and + + align:start position:0% +of genes to be so special and + + + align:start position:0% +of genes to be so special and +unfortunate right now to informaticist + + align:start position:0% +unfortunate right now to informaticist + + + align:start position:0% +unfortunate right now to informaticist +it looks like a miracle occurs that + + align:start position:0% +it looks like a miracle occurs that + + + align:start position:0% +it looks like a miracle occurs that +someone has the insight to look at one + + align:start position:0% +someone has the insight to look at one + + + align:start position:0% +someone has the insight to look at one +particular factor and you actually get a + + align:start position:0% +particular factor and you actually get a + + + align:start position:0% +particular factor and you actually get a +causal chain of events and then you can + + align:start position:0% +causal chain of events and then you can + + + align:start position:0% +causal chain of events and then you can +get your list of genes here what we + + align:start position:0% +get your list of genes here what we + + + align:start position:0% +get your list of genes here what we +realized + + align:start position:0% +realized + + + align:start position:0% +realized +is that most of these genes are + + align:start position:0% +is that most of these genes are + + + align:start position:0% +is that most of these genes are +downstream of a transcription factor + + align:start position:0% +downstream of a transcription factor + + + align:start position:0% +downstream of a transcription factor +called nrf1 and another one called pgc1 + + align:start position:0% +called nrf1 and another one called pgc1 + + + align:start position:0% +called nrf1 and another one called pgc1 +alpha + + align:start position:0% +alpha + + + align:start position:0% +alpha +it would be great if we had some + + align:start position:0% +it would be great if we had some + + + align:start position:0% +it would be great if we had some +database of these things of course we + + align:start position:0% +database of these things of course we + + + align:start position:0% +database of these things of course we +don't it'd be great if nrf1 was even on + + align:start position:0% +don't it'd be great if nrf1 was even on + + + align:start position:0% +don't it'd be great if nrf1 was even on +the chip it's not + + align:start position:0% +the chip it's not + + + align:start position:0% +the chip it's not +it's on today's chip but it wasn't on + + align:start position:0% +it's on today's chip but it wasn't on + + + align:start position:0% +it's on today's chip but it wasn't on +these chips from three generations ago + + align:start position:0% +these chips from three generations ago + + + align:start position:0% +these chips from three generations ago +so no amount of informatics and network + + align:start position:0% +so no amount of informatics and network + + + align:start position:0% +so no amount of informatics and network +building and bayes networks or any of + + align:start position:0% +building and bayes networks or any of + + + align:start position:0% +building and bayes networks or any of +that would have got us to this + + align:start position:0% +that would have got us to this + + + align:start position:0% +that would have got us to this +particular hypothesis because the gene + + align:start position:0% +particular hypothesis because the gene + + + align:start position:0% +particular hypothesis because the gene +wasn't even being measured at the time + + align:start position:0% +wasn't even being measured at the time + + + align:start position:0% +wasn't even being measured at the time +but all of these genes that i'm showing + + align:start position:0% +but all of these genes that i'm showing + + + align:start position:0% +but all of these genes that i'm showing +here again the subset of the previous + + align:start position:0% +here again the subset of the previous + + + align:start position:0% +here again the subset of the previous +subset are all downstream of nrf1 so + + align:start position:0% +subset are all downstream of nrf1 so + + + align:start position:0% +subset are all downstream of nrf1 so +that led us to actually think about the + + align:start position:0% +that led us to actually think about the + + + align:start position:0% +that led us to actually think about the +hypothesis maybe nrf1 is down and that's + + align:start position:0% +hypothesis maybe nrf1 is down and that's + + + align:start position:0% +hypothesis maybe nrf1 is down and that's +why all these other genes are down + + align:start position:0% +why all these other genes are down + + + align:start position:0% +why all these other genes are down +because it's much easier to come up with + + align:start position:0% +because it's much easier to come up with + + + align:start position:0% +because it's much easier to come up with +a causal explanation requiring just one + + align:start position:0% +a causal explanation requiring just one + + + align:start position:0% +a causal explanation requiring just one +thing to be wrong then 50 things to be + + align:start position:0% +thing to be wrong then 50 things to be + + + align:start position:0% +thing to be wrong then 50 things to be +wrong right that's occam's razor right + + align:start position:0% +wrong right that's occam's razor right + + + align:start position:0% +wrong right that's occam's razor right +simpler explanations so when you look at + + align:start position:0% +simpler explanations so when you look at + + + align:start position:0% +simpler explanations so when you look at +nrf levels again this is measuring a + + align:start position:0% +nrf levels again this is measuring a + + + align:start position:0% +nrf levels again this is measuring a +different population using a different + + align:start position:0% +different population using a different + + + align:start position:0% +different population using a different +technology rtpcr + + align:start position:0% +technology rtpcr + + + align:start position:0% +technology rtpcr +yeah the family has three negatives here + + align:start position:0% +yeah the family has three negatives here + + + align:start position:0% +yeah the family has three negatives here +positives here diabetics again and the + + align:start position:0% +positives here diabetics again and the + + + align:start position:0% +positives here diabetics again and the +gene actually has a significantly + + align:start position:0% +gene actually has a significantly + + + align:start position:0% +gene actually has a significantly +statistically significant drop in the + + align:start position:0% +statistically significant drop in the + + + align:start position:0% +statistically significant drop in the +diabetics + + align:start position:0% +diabetics + + + align:start position:0% +diabetics +but what's puzzling is that it's not + + align:start position:0% +but what's puzzling is that it's not + + + align:start position:0% +but what's puzzling is that it's not +dropping in the middle group but we saw + + align:start position:0% +dropping in the middle group but we saw + + + align:start position:0% +dropping in the middle group but we saw +those genes were down in the middle + + align:start position:0% +those genes were down in the middle + + + align:start position:0% +those genes were down in the middle +group so this isn't the perfect + + align:start position:0% +group so this isn't the perfect + + + align:start position:0% +group so this isn't the perfect +explanation at all + + align:start position:0% +explanation at all + + + align:start position:0% +explanation at all +another piece of biological knowledge + + align:start position:0% +another piece of biological knowledge + + + align:start position:0% +another piece of biological knowledge +led us to realize that nrf is actually + + align:start position:0% +led us to realize that nrf is actually + + + align:start position:0% +led us to realize that nrf is actually +itself is downstream or actually is + + align:start position:0% +itself is downstream or actually is + + + align:start position:0% +itself is downstream or actually is +co-activated by pgc1 alpha so when you + + align:start position:0% +co-activated by pgc1 alpha so when you + + + align:start position:0% +co-activated by pgc1 alpha so when you +actually measure that that you also get + + align:start position:0% +actually measure that that you also get + + + align:start position:0% +actually measure that that you also get +the clue that pgc1 alpha is down in both + + align:start position:0% +the clue that pgc1 alpha is down in both + + + align:start position:0% +the clue that pgc1 alpha is down in both +of these two groups as well as another + + align:start position:0% +of these two groups as well as another + + + align:start position:0% +of these two groups as well as another +form pgc1 beta which is down in these + + align:start position:0% +form pgc1 beta which is down in these + + + align:start position:0% +form pgc1 beta which is down in these +two groups + + align:start position:0% +two groups + + + align:start position:0% +two groups +the biggest problem though + + align:start position:0% +the biggest problem though + + + align:start position:0% +the biggest problem though +okay so now the hypothesis is that drops + + align:start position:0% +okay so now the hypothesis is that drops + + + align:start position:0% +okay so now the hypothesis is that drops +in pgc1 alpha and nrf are actually + + align:start position:0% +in pgc1 alpha and nrf are actually + + + align:start position:0% +in pgc1 alpha and nrf are actually +what's causing the difference between + + align:start position:0% +what's causing the difference between + + + align:start position:0% +what's causing the difference between +diabetics and non-diabetics and it's + + align:start position:0% +diabetics and non-diabetics and it's + + + align:start position:0% +diabetics and non-diabetics and it's +already showing a difference in the + + align:start position:0% +already showing a difference in the + + + align:start position:0% +already showing a difference in the +pre-diabetics + + align:start position:0% +pre-diabetics + + + align:start position:0% +pre-diabetics +the biggest problem though okay with + + align:start position:0% +the biggest problem though okay with + + + align:start position:0% +the biggest problem though okay with +this study is that what's the cause and + + align:start position:0% +this study is that what's the cause and + + + align:start position:0% +this study is that what's the cause and +what's the effect here okay + + align:start position:0% +what's the effect here okay + + + align:start position:0% +what's the effect here okay +already showing you that the glucose + + align:start position:0% +already showing you that the glucose + + + align:start position:0% +already showing you that the glucose +levels and insulin levels already high + + align:start position:0% +levels and insulin levels already high + + + align:start position:0% +levels and insulin levels already high +in that middle group + + align:start position:0% +in that middle group + + + align:start position:0% +in that middle group +how do i know this isn't just an effect + + align:start position:0% +how do i know this isn't just an effect + + + align:start position:0% +how do i know this isn't just an effect +of having high sugar levels + + align:start position:0% +of having high sugar levels + + + align:start position:0% +of having high sugar levels +how do i know this is causing the high + + align:start position:0% +how do i know this is causing the high + + + align:start position:0% +how do i know this is causing the high +sugar levels + + align:start position:0% +sugar levels + + + align:start position:0% +sugar levels +and that's the problem with this type of + + align:start position:0% +and that's the problem with this type of + + + align:start position:0% +and that's the problem with this type of +approach okay we can easily get samples + + align:start position:0% +approach okay we can easily get samples + + + align:start position:0% +approach okay we can easily get samples +now okay + + align:start position:0% +now okay + + + align:start position:0% +now okay +samples aren't the hard part + + align:start position:0% +samples aren't the hard part + + + align:start position:0% +samples aren't the hard part +the arrays are not the hard part + + align:start position:0% +the arrays are not the hard part + + + align:start position:0% +the arrays are not the hard part +the analysis is not the hard part + + align:start position:0% +the analysis is not the hard part + + + align:start position:0% +the analysis is not the hard part +informatics is not the hardware there's + + align:start position:0% +informatics is not the hardware there's + + + align:start position:0% +informatics is not the hardware there's +plenty of people around now plenty of + + align:start position:0% +plenty of people around now plenty of + + + align:start position:0% +plenty of people around now plenty of +software you can download + + align:start position:0% +software you can download + + + align:start position:0% +software you can download +the hard parts the interpretation in the + + align:start position:0% +the hard parts the interpretation in the + + + align:start position:0% +the hard parts the interpretation in the +end okay + + align:start position:0% +end okay + + + align:start position:0% +end okay +even though we have all these genome + + align:start position:0% +even though we have all these genome + + + align:start position:0% +even though we have all these genome +scale tools + + align:start position:0% +scale tools + + + align:start position:0% +scale tools +we still have nothing that makes the + + align:start position:0% +we still have nothing that makes the + + + align:start position:0% +we still have nothing that makes the +interpretation that much faster but that + + align:start position:0% +interpretation that much faster but that + + + align:start position:0% +interpretation that much faster but that +much easier + + align:start position:0% +much easier + + + align:start position:0% +much easier +so now it's still routine if i go to the + + align:start position:0% +so now it's still routine if i go to the + + + align:start position:0% +so now it's still routine if i go to the +johnson diabetes center look at their + + align:start position:0% +johnson diabetes center look at their + + + align:start position:0% +johnson diabetes center look at their +core facility i mean i'm just there a + + align:start position:0% +core facility i mean i'm just there a + + + align:start position:0% +core facility i mean i'm just there a +couple days ago they've literally built + + align:start position:0% +couple days ago they've literally built + + + align:start position:0% +couple days ago they've literally built +a pyramid of all the arrays they've done + + align:start position:0% +a pyramid of all the arrays they've done + + + align:start position:0% +a pyramid of all the arrays they've done +so far okay on the order of about + + align:start position:0% +so far okay on the order of about + + + align:start position:0% +so far okay on the order of about +fifteen hundred almost two thousand + + align:start position:0% +fifteen hundred almost two thousand + + + align:start position:0% +fifteen hundred almost two thousand +microarrays already done at the thousand + + align:start position:0% +microarrays already done at the thousand + + + align:start position:0% +microarrays already done at the thousand +diabetes center + + align:start position:0% +diabetes center + + + align:start position:0% +diabetes center +there's maybe been about two papers + + align:start position:0% +there's maybe been about two papers + + + align:start position:0% +there's maybe been about two papers +published so far + + align:start position:0% +published so far + + + align:start position:0% +published so far +with all of this array data okay you + + align:start position:0% +with all of this array data okay you + + + align:start position:0% +with all of this array data okay you +know this one which had about 30 samples + + align:start position:0% +know this one which had about 30 samples + + + align:start position:0% +know this one which had about 30 samples +another one that had about 10 samples + + align:start position:0% +another one that had about 10 samples + + + align:start position:0% +another one that had about 10 samples +and still there are thousands of arrays + + align:start position:0% +and still there are thousands of arrays + + + align:start position:0% +and still there are thousands of arrays +that have already been collected the + + align:start position:0% +that have already been collected the + + + align:start position:0% +that have already been collected the +data is already sitting there + + align:start position:0% +data is already sitting there + + + align:start position:0% +data is already sitting there +analysis has already been done but + + align:start position:0% +analysis has already been done but + + + align:start position:0% +analysis has already been done but +people cannot make the leap to the next + + align:start position:0% +people cannot make the leap to the next + + + align:start position:0% +people cannot make the leap to the next +step why is it this list of genes why is + + align:start position:0% +step why is it this list of genes why is + + + align:start position:0% +step why is it this list of genes why is +what's so interesting about that list of + + align:start position:0% +what's so interesting about that list of + + + align:start position:0% +what's so interesting about that list of +genes + + align:start position:0% +genes + + + align:start position:0% +genes +i think that's going to be the hard part + + align:start position:0% +i think that's going to be the hard part + + + align:start position:0% +i think that's going to be the hard part +now + + align:start position:0% +now + + + align:start position:0% +now +in the next few years okay this is not + + align:start position:0% +in the next few years okay this is not + + + align:start position:0% +in the next few years okay this is not +that novel to take samples and put them + + align:start position:0% +that novel to take samples and put them + + + align:start position:0% +that novel to take samples and put them +on a race it's not that's not what the + + align:start position:0% +on a race it's not that's not what the + + + align:start position:0% +on a race it's not that's not what the +medicine part of it is going to be about + + align:start position:0% +medicine part of it is going to be about + + + align:start position:0% +medicine part of it is going to be about +it's going to be trying to get down to + + align:start position:0% +it's going to be trying to get down to + + + align:start position:0% +it's going to be trying to get down to +simpler explanations for what we're + + align:start position:0% +simpler explanations for what we're + + + align:start position:0% +simpler explanations for what we're +seeing here + + align:start position:0% + + + + align:start position:0% + +so this is a final hypothesis here + + align:start position:0% +so this is a final hypothesis here + + + align:start position:0% +so this is a final hypothesis here +perhaps that pgc1 is down and that along + + align:start position:0% +perhaps that pgc1 is down and that along + + + align:start position:0% +perhaps that pgc1 is down and that along +with nrf is actually causing this list + + align:start position:0% +with nrf is actually causing this list + + + align:start position:0% +with nrf is actually causing this list +of genes to be different + + align:start position:0% + + + + align:start position:0% + +any questions about that so far any + + align:start position:0% +any questions about that so far any + + + align:start position:0% +any questions about that so far any +thoughts + + align:start position:0% + + + + align:start position:0% + +would you um + + align:start position:0% +would you um + + + align:start position:0% +would you um +[Music] + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +a great question okay so this question + + align:start position:0% +a great question okay so this question + + + align:start position:0% +a great question okay so this question +is have we looked at the amp kinase + + align:start position:0% +is have we looked at the amp kinase + + + align:start position:0% +is have we looked at the amp kinase +pathway okay so we know for example when + + align:start position:0% +pathway okay so we know for example when + + + align:start position:0% +pathway okay so we know for example when +people exercise + + align:start position:0% +people exercise + + + align:start position:0% +people exercise +their sensitivity to insulin improves + + align:start position:0% +their sensitivity to insulin improves + + + align:start position:0% +their sensitivity to insulin improves +okay even if they have diabetes you can + + align:start position:0% +okay even if they have diabetes you can + + + align:start position:0% +okay even if they have diabetes you can +people who exercise the same molecule of + + align:start position:0% +people who exercise the same molecule of + + + align:start position:0% +people who exercise the same molecule of +insulin has more of an effect + + align:start position:0% +insulin has more of an effect + + + align:start position:0% +insulin has more of an effect +and that's media through a different + + align:start position:0% +and that's media through a different + + + align:start position:0% +and that's media through a different +pathway okay through the amp kinase + + align:start position:0% +pathway okay through the amp kinase + + + align:start position:0% +pathway okay through the amp kinase +pathway + + align:start position:0% +pathway + + + align:start position:0% +pathway +did we look at ap kinase levels here no + + align:start position:0% +did we look at ap kinase levels here no + + + align:start position:0% +did we look at ap kinase levels here no +did we look at the expression levels + + align:start position:0% +did we look at the expression levels + + + align:start position:0% +did we look at the expression levels +they might have been on the chip but + + align:start position:0% +they might have been on the chip but + + + align:start position:0% +they might have been on the chip but +they weren't different did we look at + + align:start position:0% +they weren't different did we look at + + + align:start position:0% +they weren't different did we look at +activity levels of protein levels no + + align:start position:0% +activity levels of protein levels no + + + align:start position:0% +activity levels of protein levels no +but you can bet in that towering pile of + + align:start position:0% +but you can bet in that towering pile of + + + align:start position:0% +but you can bet in that towering pile of +a thousand arrays laurie goodyear and + + align:start position:0% +a thousand arrays laurie goodyear and + + + align:start position:0% +a thousand arrays laurie goodyear and +others have done these arrays already + + align:start position:0% +others have done these arrays already + + + align:start position:0% +others have done these arrays already +but they're still stuck the same way + + align:start position:0% +but they're still stuck the same way + + + align:start position:0% +but they're still stuck the same way +okay i mean so how what what is it about + + align:start position:0% +okay i mean so how what what is it about + + + align:start position:0% +okay i mean so how what what is it about +these lists of genes + + align:start position:0% +these lists of genes + + + align:start position:0% +these lists of genes +that's going to get us to a hypothesis + + align:start position:0% +that's going to get us to a hypothesis + + + align:start position:0% +that's going to get us to a hypothesis +here okay + + align:start position:0% +here okay + + + align:start position:0% +here okay +it's very unwieldy it's very hard to + + align:start position:0% +it's very unwieldy it's very hard to + + + align:start position:0% +it's very unwieldy it's very hard to +deal with these lists of hundreds of + + align:start position:0% +deal with these lists of hundreds of + + + align:start position:0% +deal with these lists of hundreds of +genes okay + + align:start position:0% +genes okay + + + align:start position:0% +genes okay +it's not very validating anymore it's + + align:start position:0% +it's not very validating anymore it's + + + align:start position:0% +it's not very validating anymore it's +not very fun to work with these genes + + align:start position:0% +not very fun to work with these genes + + + align:start position:0% +not very fun to work with these genes +the hard part is to get down to the + + align:start position:0% +the hard part is to get down to the + + + align:start position:0% +the hard part is to get down to the +causal mechanism for those genes and + + align:start position:0% +causal mechanism for those genes and + + + align:start position:0% +causal mechanism for those genes and +that's where we have the least + + align:start position:0% +that's where we have the least + + + align:start position:0% +that's where we have the least +information right now what what's + + align:start position:0% +information right now what what's + + + align:start position:0% +information right now what what's +upstream of what for example + + align:start position:0% +upstream of what for example + + + align:start position:0% +upstream of what for example +you go back to the chicken and egg + + align:start position:0% +you go back to the chicken and egg + + + align:start position:0% +you go back to the chicken and egg +right + + align:start position:0% + + + + align:start position:0% + +i was just wondering now you're saying + + align:start position:0% +i was just wondering now you're saying + + + align:start position:0% +i was just wondering now you're saying +that you have a decrease in the ox loss + + align:start position:0% +that you have a decrease in the ox loss + + + align:start position:0% +that you have a decrease in the ox loss +lipid + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +you're not uh primarily you're not + + align:start position:0% +you're not uh primarily you're not + + + align:start position:0% +you're not uh primarily you're not +generating atp as efficiently as you + + align:start position:0% +generating atp as efficiently as you + + + align:start position:0% +generating atp as efficiently as you +could okay or + + align:start position:0% +could okay or + + + align:start position:0% +could okay or +in a muscle yeah well if you're if + + align:start position:0% +in a muscle yeah well if you're if + + + align:start position:0% +in a muscle yeah well if you're if +you're if you're generating atp + + align:start position:0% +you're if you're generating atp + + + align:start position:0% +you're if you're generating atp +inefficiently + + align:start position:0% +inefficiently + + + align:start position:0% +inefficiently +that's the equivalent of like having off + + align:start position:0% +that's the equivalent of like having off + + + align:start position:0% +that's the equivalent of like having off +spots decoupling or something right + + align:start position:0% +spots decoupling or something right + + + align:start position:0% +spots decoupling or something right +exactly this is you're actually not + + align:start position:0% +exactly this is you're actually not + + + align:start position:0% +exactly this is you're actually not +generating the atp and instead yeah the + + align:start position:0% +generating the atp and instead yeah the + + + align:start position:0% +generating the atp and instead yeah the +pipe is straight exactly the pipe is not + + align:start position:0% +pipe is straight exactly the pipe is not + + + align:start position:0% +pipe is straight exactly the pipe is not +being full exactly the pipe is not being + + align:start position:0% +being full exactly the pipe is not being + + + align:start position:0% +being full exactly the pipe is not being +filled as efficiently as it can be right + + align:start position:0% +filled as efficiently as it can be right + + + align:start position:0% +filled as efficiently as it can be right +so absolutely if you use that and you go + + align:start position:0% +so absolutely if you use that and you go + + + align:start position:0% +so absolutely if you use that and you go +back and use your sort of backwards + + align:start position:0% +back and use your sort of backwards + + + align:start position:0% +back and use your sort of backwards +reasoning okay + + align:start position:0% +reasoning okay + + + align:start position:0% +reasoning okay +wouldn't that basically suggest that + + align:start position:0% +wouldn't that basically suggest that + + + align:start position:0% +wouldn't that basically suggest that +the initial perturbation is in + + align:start position:0% +the initial perturbation is in + + + align:start position:0% +the initial perturbation is in +nrf and uh + + align:start position:0% +nrf and uh + + + align:start position:0% +nrf and uh +dpar + + align:start position:0% + + + + align:start position:0% + +so there's other ways we can there's + + align:start position:0% +so there's other ways we can there's + + + align:start position:0% +so there's other ways we can there's +other pieces of information that we can + + align:start position:0% +other pieces of information that we can + + + align:start position:0% +other pieces of information that we can +bring to this to try to figure out the + + align:start position:0% +bring to this to try to figure out the + + + align:start position:0% +bring to this to try to figure out the +ordering of them right so there are + + align:start position:0% +ordering of them right so there are + + + align:start position:0% +ordering of them right so there are +sequence polymorphisms that are known in + + align:start position:0% +sequence polymorphisms that are known in + + + align:start position:0% +sequence polymorphisms that are known in +these genes okay like uh specifically in + + align:start position:0% +these genes okay like uh specifically in + + + align:start position:0% +these genes okay like uh specifically in +pgc1 that go along to having diabetes + + align:start position:0% +pgc1 that go along to having diabetes + + + align:start position:0% +pgc1 that go along to having diabetes +okay so we think well if people if + + align:start position:0% +okay so we think well if people if + + + align:start position:0% +okay so we think well if people if +there's people have an abnormal sequence + + align:start position:0% +there's people have an abnormal sequence + + + align:start position:0% +there's people have an abnormal sequence +and they get diabetes maybe that's + + align:start position:0% +and they get diabetes maybe that's + + + align:start position:0% +and they get diabetes maybe that's +what's causing it + + align:start position:0% +what's causing it + + + align:start position:0% +what's causing it +okay right that's what puts this + + align:start position:0% +okay right that's what puts this + + + align:start position:0% +okay right that's what puts this +upstream of the actual having the high + + align:start position:0% +upstream of the actual having the high + + + align:start position:0% +upstream of the actual having the high +sugar levels + + align:start position:0% +sugar levels + + + align:start position:0% +sugar levels +but in this sample without without that + + align:start position:0% +but in this sample without without that + + + align:start position:0% +but in this sample without without that +a priori knowledge you can't tell that + + align:start position:0% +a priori knowledge you can't tell that + + + align:start position:0% +a priori knowledge you can't tell that +that's the issue but doesn't it suggest + + align:start position:0% +that's the issue but doesn't it suggest + + + align:start position:0% +that's the issue but doesn't it suggest +that now or is that a giant leap in + + align:start position:0% +that now or is that a giant leap in + + + align:start position:0% +that now or is that a giant leap in +other words in other words + + align:start position:0% +other words in other words + + + align:start position:0% +other words in other words +if the glucose level was high if the + + align:start position:0% +if the glucose level was high if the + + + align:start position:0% +if the glucose level was high if the +initial + + align:start position:0% +initial + + + align:start position:0% +initial +perturbation for the elevated blood was + + align:start position:0% +perturbation for the elevated blood was + + + align:start position:0% +perturbation for the elevated blood was +though okay yep if it were that + + align:start position:0% +though okay yep if it were that + + + align:start position:0% +though okay yep if it were that +and that doesn't + + align:start position:0% +and that doesn't + + + align:start position:0% +and that doesn't +explain why you have + + align:start position:0% +explain why you have + + + align:start position:0% +explain why you have +uh up regulation of uh + + align:start position:0% +uh up regulation of uh + + + align:start position:0% +uh up regulation of uh +down regulation nrf and uh + + align:start position:0% +down regulation nrf and uh + + + align:start position:0% +down regulation nrf and uh +whatever it is is it up or down + + align:start position:0% +whatever it is is it up or down + + + align:start position:0% +whatever it is is it up or down +the nrf is down all i'm saying is with + + align:start position:0% +the nrf is down all i'm saying is with + + + align:start position:0% +the nrf is down all i'm saying is with +just this experiment i could put this + + align:start position:0% +just this experiment i could put this + + + align:start position:0% +just this experiment i could put this +square up here + + align:start position:0% +square up here + + + align:start position:0% +square up here +and say that is leading to this leading + + align:start position:0% +and say that is leading to this leading + + + align:start position:0% +and say that is leading to this leading +to this leading to this list of this + + align:start position:0% +to this leading to this list of this + + + align:start position:0% +to this leading to this list of this +right + + align:start position:0% +right + + + align:start position:0% +right +i can't make that leap that this is + + align:start position:0% +i can't make that leap that this is + + + align:start position:0% +i can't make that leap that this is +causal + + align:start position:0% +causal + + + align:start position:0% +causal +it's more suggestive that the square is + + align:start position:0% +it's more suggestive that the square is + + + align:start position:0% +it's more suggestive that the square is +down there where am i not thinking about + + align:start position:0% +down there where am i not thinking about + + + align:start position:0% +down there where am i not thinking about +with the sequence by morphisms and + + align:start position:0% +with the sequence by morphisms and + + + align:start position:0% +with the sequence by morphisms and +things it makes me think that it's down + + align:start position:0% +things it makes me think that it's down + + + align:start position:0% +things it makes me think that it's down +here but just the experiment by itself + + align:start position:0% +here but just the experiment by itself + + + align:start position:0% +here but just the experiment by itself +without the a priori knowledge okay + + align:start position:0% +without the a priori knowledge okay + + + align:start position:0% +without the a priori knowledge okay +without knowing what the literature + + align:start position:0% +without knowing what the literature + + + align:start position:0% +without knowing what the literature +tells you + + align:start position:0% +tells you + + + align:start position:0% +tells you +how would you know that because these + + align:start position:0% +how would you know that because these + + + align:start position:0% +how would you know that because these +patients already have some degree of + + align:start position:0% +patients already have some degree of + + + align:start position:0% +patients already have some degree of +resistance + + align:start position:0% +resistance + + + align:start position:0% +resistance +that's the issue here right you need to + + align:start position:0% +that's the issue here right you need to + + + align:start position:0% +that's the issue here right you need to +know what the the biology cannot ignore + + align:start position:0% +know what the the biology cannot ignore + + + align:start position:0% +know what the the biology cannot ignore +the biology + + align:start position:0% +the biology + + + align:start position:0% +the biology +there's no question + + align:start position:0% +there's no question + + + align:start position:0% +there's no question +what's + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +absolutely + + align:start position:0% +absolutely + + + align:start position:0% +absolutely +exactly right so right and so you picked + + align:start position:0% +exactly right so right and so you picked + + + align:start position:0% +exactly right so right and so you picked +up on that as well i mean so um + + align:start position:0% +up on that as well i mean so um + + + align:start position:0% +up on that as well i mean so um +yeah body mass index is different too + + align:start position:0% +yeah body mass index is different too + + + align:start position:0% +yeah body mass index is different too +because it's hard to find + + align:start position:0% +because it's hard to find + + + align:start position:0% +because it's hard to find +i mean that's life in america now + + align:start position:0% +i mean that's life in america now + + + align:start position:0% +i mean that's life in america now +everyone is obese okay + + align:start position:0% +everyone is obese okay + + + align:start position:0% +everyone is obese okay +and so even teenagers that are obese + + align:start position:0% +and so even teenagers that are obese + + + align:start position:0% +and so even teenagers that are obese +have some would would might be in this + + align:start position:0% +have some would would might be in this + + + align:start position:0% +have some would would might be in this +middle group now they will have some + + align:start position:0% +middle group now they will have some + + + align:start position:0% +middle group now they will have some +impaired glucose tolerance + + align:start position:0% + + + + align:start position:0% + +the control group was uh i mean their + + align:start position:0% +the control group was uh i mean their + + + align:start position:0% +the control group was uh i mean their +body mass index is still 30 okay that + + align:start position:0% +body mass index is still 30 okay that + + + align:start position:0% +body mass index is still 30 okay that +qualifies as obese today + + align:start position:0% +qualifies as obese today + + + align:start position:0% +qualifies as obese today +and the family history was actually + + align:start position:0% +and the family history was actually + + + align:start position:0% +and the family history was actually +slightly less but they're all obese + + align:start position:0% +slightly less but they're all obese + + + align:start position:0% +slightly less but they're all obese +basically right especially the controls + + align:start position:0% + + + + align:start position:0% + +absolutely + + align:start position:0% +absolutely + + + align:start position:0% +absolutely +yeah absolutely + + align:start position:0% +yeah absolutely + + + align:start position:0% +yeah absolutely +uh this one here + + align:start position:0% +uh this one here + + + align:start position:0% +uh this one here +yep exactly + + align:start position:0% +yep exactly + + + align:start position:0% +yep exactly +this is a one gene versus the other and + + align:start position:0% +this is a one gene versus the other and + + + align:start position:0% +this is a one gene versus the other and +you can see the body mass index here + + align:start position:0% +you can see the body mass index here + + + align:start position:0% +you can see the body mass index here +exactly and you got one all the way over + + align:start position:0% +exactly and you got one all the way over + + + align:start position:0% +exactly and you got one all the way over +here exactly that's destroying the mean + + align:start position:0% +here exactly that's destroying the mean + + + align:start position:0% +here exactly that's destroying the mean +so these are not otherwise equal groups + + align:start position:0% +so these are not otherwise equal groups + + + align:start position:0% +so these are not otherwise equal groups +that's the problem + + align:start position:0% +that's the problem + + + align:start position:0% +that's the problem +now you have to so + + align:start position:0% +now you have to so + + + align:start position:0% +now you have to so +why am i even showing all this if i'm if + + align:start position:0% +why am i even showing all this if i'm if + + + align:start position:0% +why am i even showing all this if i'm if +i have all these problems with this + + align:start position:0% +i have all these problems with this + + + align:start position:0% +i have all these problems with this +analysis and this data the whole point + + align:start position:0% +analysis and this data the whole point + + + align:start position:0% +analysis and this data the whole point +of this kind of course is not just to + + align:start position:0% +of this kind of course is not just to + + + align:start position:0% +of this kind of course is not just to +teach you how to + + align:start position:0% +teach you how to + + + align:start position:0% +teach you how to +look at how to do these types of + + align:start position:0% +look at how to do these types of + + + align:start position:0% +look at how to do these types of +experiments to me it would be great if + + align:start position:0% +experiments to me it would be great if + + + align:start position:0% +experiments to me it would be great if +you knew how to interpret these things + + align:start position:0% +you knew how to interpret these things + + + align:start position:0% +you knew how to interpret these things +that come out in the new england journal + + align:start position:0% +that come out in the new england journal + + + align:start position:0% +that come out in the new england journal +every day okay + + align:start position:0% +every day okay + + + align:start position:0% +every day okay +because every every month now we see a + + align:start position:0% +because every every month now we see a + + + align:start position:0% +because every every month now we see a +microwave paper say the new england + + align:start position:0% +microwave paper say the new england + + + align:start position:0% +microwave paper say the new england +journal or jama or other equivalent + + align:start position:0% +journal or jama or other equivalent + + + align:start position:0% +journal or jama or other equivalent +publications + + align:start position:0% +publications + + + align:start position:0% +publications +and i think we have to teach people to + + align:start position:0% +and i think we have to teach people to + + + align:start position:0% +and i think we have to teach people to +how to read these things with a critical + + align:start position:0% +how to read these things with a critical + + + align:start position:0% +how to read these things with a critical +eye + + align:start position:0% +eye + + + align:start position:0% +eye +okay because it looks so fancy to come + + align:start position:0% +okay because it looks so fancy to come + + + align:start position:0% +okay because it looks so fancy to come +out with 44 000 genes and these are the + + align:start position:0% +out with 44 000 genes and these are the + + + align:start position:0% +out with 44 000 genes and these are the +ones actually diagnostic but there's + + align:start position:0% +ones actually diagnostic but there's + + + align:start position:0% +ones actually diagnostic but there's +actually problems with experimental + + align:start position:0% +actually problems with experimental + + + align:start position:0% +actually problems with experimental +design if the experiment was not + + align:start position:0% +design if the experiment was not + + + align:start position:0% +design if the experiment was not +designed in exactly the way that the + + align:start position:0% +designed in exactly the way that the + + + align:start position:0% +designed in exactly the way that the +answer the question that was being asked + + align:start position:0% +answer the question that was being asked + + + align:start position:0% +answer the question that was being asked +no amount of fancy arrays is going to be + + align:start position:0% +no amount of fancy arrays is going to be + + + align:start position:0% +no amount of fancy arrays is going to be +able to help you can't salvage that okay + + align:start position:0% +able to help you can't salvage that okay + + + align:start position:0% +able to help you can't salvage that okay +that's what i'm trying to get across is + + align:start position:0% +that's what i'm trying to get across is + + + align:start position:0% +that's what i'm trying to get across is +to be how to be critical here + + align:start position:0% + + + + align:start position:0% + +think the same thing okay when you see a + + align:start position:0% +think the same thing okay when you see a + + + align:start position:0% +think the same thing okay when you see a +bunch of genes that distinguishes a-l-l + + align:start position:0% +bunch of genes that distinguishes a-l-l + + + align:start position:0% +bunch of genes that distinguishes a-l-l +from aml + + align:start position:0% +from aml + + + align:start position:0% +from aml +okay just think about all the other + + align:start position:0% +okay just think about all the other + + + align:start position:0% +okay just think about all the other +things in their context that could be + + align:start position:0% +things in their context that could be + + + align:start position:0% +things in their context that could be +making a difference here okay + + align:start position:0% +making a difference here okay + + + align:start position:0% +making a difference here okay +when were the samples acquired where + + align:start position:0% +when were the samples acquired where + + + align:start position:0% +when were the samples acquired where +were they acquired you know our patients + + align:start position:0% +were they acquired you know our patients + + + align:start position:0% +were they acquired you know our patients +with aml preferentially sent to one + + align:start position:0% +with aml preferentially sent to one + + + align:start position:0% +with aml preferentially sent to one +center and the ones with all sent to + + align:start position:0% +center and the ones with all sent to + + + align:start position:0% +center and the ones with all sent to +another center + + align:start position:0% +another center + + + align:start position:0% +another center +okay + + align:start position:0% +okay + + + align:start position:0% +okay +my favorite example i'd love to give is + + align:start position:0% +my favorite example i'd love to give is + + + align:start position:0% +my favorite example i'd love to give is +this okay let's say you're looking at a + + align:start position:0% +this okay let's say you're looking at a + + + align:start position:0% +this okay let's say you're looking at a +solid tumor and you're trying to + + align:start position:0% +solid tumor and you're trying to + + + align:start position:0% +solid tumor and you're trying to +distinguish the genes that are different + + align:start position:0% +distinguish the genes that are different + + + align:start position:0% +distinguish the genes that are different +between the metastatic form of this + + align:start position:0% +between the metastatic form of this + + + align:start position:0% +between the metastatic form of this +cancer and the non-metastatic form + + align:start position:0% +cancer and the non-metastatic form + + + align:start position:0% +cancer and the non-metastatic form +okay have you spent any time in the + + align:start position:0% +okay have you spent any time in the + + + align:start position:0% +okay have you spent any time in the +wards you know how surgeons work okay if + + align:start position:0% +wards you know how surgeons work okay if + + + align:start position:0% +wards you know how surgeons work okay if +you have a patient if a surgeon is + + align:start position:0% +you have a patient if a surgeon is + + + align:start position:0% +you have a patient if a surgeon is +looking at their caseload for the next + + align:start position:0% +looking at their caseload for the next + + + align:start position:0% +looking at their caseload for the next +day and they have a patient with + + align:start position:0% +day and they have a patient with + + + align:start position:0% +day and they have a patient with +metastatic and patient non-metastatic + + align:start position:0% +metastatic and patient non-metastatic + + + align:start position:0% +metastatic and patient non-metastatic +they're basically metastatic it's + + align:start position:0% +they're basically metastatic it's + + + align:start position:0% +they're basically metastatic it's +already metastasized the surgery is + + align:start position:0% +already metastasized the surgery is + + + align:start position:0% +already metastasized the surgery is +going to be a hell of a lot longer let's + + align:start position:0% +going to be a hell of a lot longer let's + + + align:start position:0% +going to be a hell of a lot longer let's +say okay because i have to go check this + + align:start position:0% +say okay because i have to go check this + + + align:start position:0% +say okay because i have to go check this +check that clean this out clean that out + + align:start position:0% +check that clean this out clean that out + + + align:start position:0% +check that clean this out clean that out +the surgeon might say i'm going to put + + align:start position:0% +the surgeon might say i'm going to put + + + align:start position:0% +the surgeon might say i'm going to put +that patient as the first case of the + + align:start position:0% +that patient as the first case of the + + + align:start position:0% +that patient as the first case of the +day + + align:start position:0% +day + + + align:start position:0% +day +okay and the simpler case i'm going to + + align:start position:0% +okay and the simpler case i'm going to + + + align:start position:0% +okay and the simpler case i'm going to +put on as a follow-on or an add-on case + + align:start position:0% +put on as a follow-on or an add-on case + + + align:start position:0% +put on as a follow-on or an add-on case +keep them waiting in the waiting room or + + align:start position:0% +keep them waiting in the waiting room or + + + align:start position:0% +keep them waiting in the waiting room or +in the recovery room ready to go and + + align:start position:0% +in the recovery room ready to go and + + + align:start position:0% +in the recovery room ready to go and +then we're going to do them after this + + align:start position:0% +then we're going to do them after this + + + align:start position:0% +then we're going to do them after this +first case is done + + align:start position:0% +first case is done + + + align:start position:0% +first case is done +so now imagine a study where you look at + + align:start position:0% +so now imagine a study where you look at + + + align:start position:0% +so now imagine a study where you look at +the difference between metastatic and + + align:start position:0% +the difference between metastatic and + + + align:start position:0% +the difference between metastatic and +non-metastatic forms of this particular + + align:start position:0% +non-metastatic forms of this particular + + + align:start position:0% +non-metastatic forms of this particular +cancer + + align:start position:0% +cancer + + + align:start position:0% +cancer +they got these samples from these + + align:start position:0% +they got these samples from these + + + align:start position:0% +they got these samples from these +surgeons who preferentially put the hard + + align:start position:0% +surgeons who preferentially put the hard + + + align:start position:0% +surgeons who preferentially put the hard +cases in the morning and the easy cases + + align:start position:0% +cases in the morning and the easy cases + + + align:start position:0% +cases in the morning and the easy cases +in the afternoon + + align:start position:0% +in the afternoon + + + align:start position:0% +in the afternoon +okay i'm an endocrinologist i know that + + align:start position:0% +okay i'm an endocrinologist i know that + + + align:start position:0% +okay i'm an endocrinologist i know that +they're hormones that are different + + align:start position:0% +they're hormones that are different + + + align:start position:0% +they're hormones that are different +between morning and evening right with + + align:start position:0% +between morning and evening right with + + + align:start position:0% +between morning and evening right with +insulin growth hormone cortisol + + align:start position:0% +insulin growth hormone cortisol + + + align:start position:0% +insulin growth hormone cortisol +who knows how many genes are downstream + + align:start position:0% +who knows how many genes are downstream + + + align:start position:0% +who knows how many genes are downstream +of those hormones + + align:start position:0% +of those hormones + + + align:start position:0% +of those hormones +and how do you know that the signal that + + align:start position:0% +and how do you know that the signal that + + + align:start position:0% +and how do you know that the signal that +you're seeing isn't because of that bias + + align:start position:0% +you're seeing isn't because of that bias + + + align:start position:0% +you're seeing isn't because of that bias +or the confounding there + + align:start position:0% +or the confounding there + + + align:start position:0% +or the confounding there +now this is not revolutionary stuff + + align:start position:0% +now this is not revolutionary stuff + + + align:start position:0% +now this is not revolutionary stuff +right if we looked at clinical tests or + + align:start position:0% +right if we looked at clinical tests or + + + align:start position:0% +right if we looked at clinical tests or +clinical trials in the past we need to + + align:start position:0% +clinical trials in the past we need to + + + align:start position:0% +clinical trials in the past we need to +look for these things but all of a + + align:start position:0% +look for these things but all of a + + + align:start position:0% +look for these things but all of a +sudden now that we have these fancy red + + align:start position:0% +sudden now that we have these fancy red + + + align:start position:0% +sudden now that we have these fancy red +grenograms and we have these microwaves + + align:start position:0% +grenograms and we have these microwaves + + + align:start position:0% +grenograms and we have these microwaves +people have forgotten about all of this + + align:start position:0% +people have forgotten about all of this + + + align:start position:0% +people have forgotten about all of this +traditional these traditional + + align:start position:0% +traditional these traditional + + + align:start position:0% +traditional these traditional +confounders + + align:start position:0% +confounders + + + align:start position:0% +confounders +okay we're measuring across the entire + + align:start position:0% +okay we're measuring across the entire + + + align:start position:0% +okay we're measuring across the entire +measurable genome the signal that you + + align:start position:0% +measurable genome the signal that you + + + align:start position:0% +measurable genome the signal that you +get just from endocrinology from + + align:start position:0% +get just from endocrinology from + + + align:start position:0% +get just from endocrinology from +circadian cycles might be stronger than + + align:start position:0% +circadian cycles might be stronger than + + + align:start position:0% +circadian cycles might be stronger than +the signal that you actually think + + align:start position:0% +the signal that you actually think + + + align:start position:0% +the signal that you actually think +you're measuring + + align:start position:0% +you're measuring + + + align:start position:0% +you're measuring +now you go back and look at the last + + align:start position:0% +now you go back and look at the last + + + align:start position:0% +now you go back and look at the last +three microarray papers that are in the + + align:start position:0% +three microarray papers that are in the + + + align:start position:0% +three microarray papers that are in the +new england journal medicine and just + + align:start position:0% +new england journal medicine and just + + + align:start position:0% +new england journal medicine and just +look to see if you can figure out what + + align:start position:0% +look to see if you can figure out what + + + align:start position:0% +look to see if you can figure out what +time of day these samples were acquired + + align:start position:0% +time of day these samples were acquired + + + align:start position:0% +time of day these samples were acquired +no way + + align:start position:0% +no way + + + align:start position:0% +no way +i know sensitive is something like that + + align:start position:0% +i know sensitive is something like that + + + align:start position:0% +i know sensitive is something like that +and well two part questions one you know + + align:start position:0% +and well two part questions one you know + + + align:start position:0% +and well two part questions one you know +it's a matter of like between 8 a.m and + + align:start position:0% +it's a matter of like between 8 a.m and + + + align:start position:0% +it's a matter of like between 8 a.m and +8 30 and that sort of thing and + + align:start position:0% +8 30 and that sort of thing and + + + align:start position:0% +8 30 and that sort of thing and +it's not even known + + align:start position:0% +it's not even known + + + align:start position:0% +it's not even known +right so it might not be known but then + + align:start position:0% +right so it might not be known but then + + + align:start position:0% +right so it might not be known but then +what i would say is we should randomize + + align:start position:0% +what i would say is we should randomize + + + align:start position:0% +what i would say is we should randomize +across that variable + + align:start position:0% +across that variable + + + align:start position:0% +across that variable +okay + + align:start position:0% +okay + + + align:start position:0% +okay +you could turn the lights on there + + align:start position:0% +you could turn the lights on there + + + align:start position:0% +you could turn the lights on there +we should randomize across that variable + + align:start position:0% +we should randomize across that variable + + + align:start position:0% +we should randomize across that variable +okay so for example someone should be + + align:start position:0% +okay so for example someone should be + + + align:start position:0% +okay so for example someone should be +looking at the clock and say well these + + align:start position:0% +looking at the clock and say well these + + + align:start position:0% +looking at the clock and say well these +are all acquired there's some that are + + align:start position:0% +are all acquired there's some that are + + + align:start position:0% +are all acquired there's some that are +here some that are here some that are + + align:start position:0% +here some that are here some that are + + + align:start position:0% +here some that are here some that are +here and just convince yourself that + + align:start position:0% +here and just convince yourself that + + + align:start position:0% +here and just convince yourself that +it's not just a gross bias + + align:start position:0% +it's not just a gross bias + + + align:start position:0% +it's not just a gross bias +i'm just making a fake you know a fake + + align:start position:0% +i'm just making a fake you know a fake + + + align:start position:0% +i'm just making a fake you know a fake +story here that's believable + + align:start position:0% +story here that's believable + + + align:start position:0% +story here that's believable +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +in the morning of the afternoon sure you + + align:start position:0% +in the morning of the afternoon sure you + + + align:start position:0% +in the morning of the afternoon sure you +can try to compensate from support some + + align:start position:0% +can try to compensate from support some + + + align:start position:0% +can try to compensate from support some +other way + + align:start position:0% +other way + + + align:start position:0% +other way +but it's going to be relative to their + + align:start position:0% +but it's going to be relative to their + + + align:start position:0% +but it's going to be relative to their +hormone levels too probably + + align:start position:0% +hormone levels too probably + + + align:start position:0% +hormone levels too probably +i guess the example that you gave in + + align:start position:0% +i guess the example that you gave in + + + align:start position:0% +i guess the example that you gave in +that is it's just sort of going out + + align:start position:0% +that is it's just sort of going out + + + align:start position:0% +that is it's just sort of going out +there + + align:start position:0% +there + + + align:start position:0% +there +uh but + + align:start position:0% +uh but + + + align:start position:0% +uh but +you know i i guess + + align:start position:0% +you know i i guess + + + align:start position:0% +you know i i guess +it's different than like in a laboratory + + align:start position:0% +it's different than like in a laboratory + + + align:start position:0% +it's different than like in a laboratory +setting + + align:start position:0% +setting + + + align:start position:0% +setting +exactly cells in a dish and you you know + + align:start position:0% +exactly cells in a dish and you you know + + + align:start position:0% +exactly cells in a dish and you you know +if they die it's like yeah + + align:start position:0% +if they die it's like yeah + + + align:start position:0% +if they die it's like yeah +exactly you know + + align:start position:0% +exactly you know + + + align:start position:0% +exactly you know +i mean + + align:start position:0% +i mean + + + align:start position:0% +i mean +exactly we've taken this technology that + + align:start position:0% +exactly we've taken this technology that + + + align:start position:0% +exactly we've taken this technology that +we've used in micro of using cells in + + align:start position:0% +we've used in micro of using cells in + + + align:start position:0% +we've used in micro of using cells in +cell culture from cell lines and rapidly + + align:start position:0% +cell culture from cell lines and rapidly + + + align:start position:0% +cell culture from cell lines and rapidly +moved it to patients right + + align:start position:0% +moved it to patients right + + + align:start position:0% +moved it to patients right +that exist in a context okay even the + + align:start position:0% +that exist in a context okay even the + + + align:start position:0% +that exist in a context okay even the +middle ground of just using them in lab + + align:start position:0% +middle ground of just using them in lab + + + align:start position:0% +middle ground of just using them in lab +mice okay look at the same mice same + + align:start position:0% +mice okay look at the same mice same + + + align:start position:0% +mice okay look at the same mice same +condition same everything there's genes + + align:start position:0% +condition same everything there's genes + + + align:start position:0% +condition same everything there's genes +that are different right + + align:start position:0% +that are different right + + + align:start position:0% +that are different right +one of the mice was an alpha male in + + align:start position:0% +one of the mice was an alpha male in + + + align:start position:0% +one of the mice was an alpha male in +that little cage and one wasn't you know + + align:start position:0% +that little cage and one wasn't you know + + + align:start position:0% +that little cage and one wasn't you know +there's differences between things that + + align:start position:0% +there's differences between things that + + + align:start position:0% +there's differences between things that +we think are otherwise the same but now + + align:start position:0% +we think are otherwise the same but now + + + align:start position:0% +we think are otherwise the same but now +we've taken to this extreme because + + align:start position:0% +we've taken to this extreme because + + + align:start position:0% +we've taken to this extreme because +there's a course you're in a course + + align:start position:0% +there's a course you're in a course + + + align:start position:0% +there's a course you're in a course +called genomic medicine and that's what + + align:start position:0% +called genomic medicine and that's what + + + align:start position:0% +called genomic medicine and that's what +we're doing today + + align:start position:0% +we're doing today + + + align:start position:0% +we're doing today +these are the problems that we have with + + align:start position:0% +these are the problems that we have with + + + align:start position:0% +these are the problems that we have with +that type of approach + + align:start position:0% +that type of approach + + + align:start position:0% +that type of approach +okay i i kid you not go back to the last + + align:start position:0% +okay i i kid you not go back to the last + + + align:start position:0% +okay i i kid you not go back to the last +few microwave papers in england journal + + align:start position:0% +few microwave papers in england journal + + + align:start position:0% +few microwave papers in england journal +you will not see what time of day + + align:start position:0% +you will not see what time of day + + + align:start position:0% +you will not see what time of day +if you go to supplemental material + + align:start position:0% +if you go to supplemental material + + + align:start position:0% +if you go to supplemental material +nobody might not i think people don't + + align:start position:0% +nobody might not i think people don't + + + align:start position:0% +nobody might not i think people don't +even write that stuff down + + align:start position:0% +even write that stuff down + + + align:start position:0% +even write that stuff down +and it's a problem i've only seen one + + align:start position:0% +and it's a problem i've only seen one + + + align:start position:0% +and it's a problem i've only seen one +paper so far address this issue so what + + align:start position:0% +paper so far address this issue so what + + + align:start position:0% +paper so far address this issue so what +would your suggestion be i mean + + align:start position:0% +would your suggestion be i mean + + + align:start position:0% +would your suggestion be i mean +obviously to us + + align:start position:0% +obviously to us + + + align:start position:0% +obviously to us +control for that it's a control for it + + align:start position:0% +control for that it's a control for it + + + align:start position:0% +control for that it's a control for it +but in that injury why there's labs that + + align:start position:0% +but in that injury why there's labs that + + + align:start position:0% +but in that injury why there's labs that +you know really maybe aren't speaking + + align:start position:0% +you know really maybe aren't speaking + + + align:start position:0% +you know really maybe aren't speaking +about this yep + + align:start position:0% +about this yep + + + align:start position:0% +about this yep +you can do whatever + + align:start position:0% +you can do whatever + + + align:start position:0% +you can do whatever +is saying + + align:start position:0% +is saying + + + align:start position:0% +is saying +no but you can try to model that okay so + + align:start position:0% +no but you can try to model that okay so + + + align:start position:0% +no but you can try to model that okay so +so take some other tissue that's related + + align:start position:0% +so take some other tissue that's related + + + align:start position:0% +so take some other tissue that's related +and see just across a sampling of time + + align:start position:0% +and see just across a sampling of time + + + align:start position:0% +and see just across a sampling of time +points what genes are different and + + align:start position:0% +points what genes are different and + + + align:start position:0% +points what genes are different and +maybe you can then subtract out that + + align:start position:0% +maybe you can then subtract out that + + + align:start position:0% +maybe you can then subtract out that +effect but more importantly what i would + + align:start position:0% +effect but more importantly what i would + + + align:start position:0% +effect but more importantly what i would +say is if you're going to make a list of + + align:start position:0% +say is if you're going to make a list of + + + align:start position:0% +say is if you're going to make a list of +genes that you think are diagnostic + + align:start position:0% +genes that you think are diagnostic + + + align:start position:0% +genes that you think are diagnostic +we're going to have to be as physicians + + align:start position:0% +we're going to have to be as physicians + + + align:start position:0% +we're going to have to be as physicians +we're going to have to look at that with + + align:start position:0% +we're going to have to look at that with + + + align:start position:0% +we're going to have to look at that with +a very skeptical eye okay because you + + align:start position:0% +a very skeptical eye okay because you + + + align:start position:0% +a very skeptical eye okay because you +cannot control for everything here + + align:start position:0% +cannot control for everything here + + + align:start position:0% +cannot control for everything here +right but we're measuring across so many + + align:start position:0% +right but we're measuring across so many + + + align:start position:0% +right but we're measuring across so many +genes + + align:start position:0% +genes + + + align:start position:0% +genes +and have so few samples + + align:start position:0% +and have so few samples + + + align:start position:0% +and have so few samples +okay that no matter what we're going to + + align:start position:0% +okay that no matter what we're going to + + + align:start position:0% +okay that no matter what we're going to +be over fitting the data here that's + + align:start position:0% +be over fitting the data here that's + + + align:start position:0% +be over fitting the data here that's +what i'm worried about okay we're going + + align:start position:0% +what i'm worried about okay we're going + + + align:start position:0% +what i'm worried about okay we're going +to be over fitting what we have + + align:start position:0% +to be over fitting what we have + + + align:start position:0% +to be over fitting what we have +no amount of control samples is going to + + align:start position:0% +no amount of control samples is going to + + + align:start position:0% +no amount of control samples is going to +help us + + align:start position:0% +help us + + + align:start position:0% +help us +fix that problem i think + + align:start position:0% + + + + align:start position:0% + +what are we doing for time okay + + align:start position:0% + + + + align:start position:0% + +let's talk uh + + align:start position:0% +let's talk uh + + + align:start position:0% +let's talk uh +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +let's go let's go a little bit more into + + align:start position:0% +let's go let's go a little bit more into + + + align:start position:0% +let's go let's go a little bit more into +the diabetes so what i was planning to + + align:start position:0% +the diabetes so what i was planning to + + + align:start position:0% +the diabetes so what i was planning to +do is talk about uh one more diabetes + + align:start position:0% +do is talk about uh one more diabetes + + + align:start position:0% +do is talk about uh one more diabetes +project that we've been doing + + align:start position:0% +project that we've been doing + + + align:start position:0% +project that we've been doing +then i'm going to talk about some web + + align:start position:0% +then i'm going to talk about some web + + + align:start position:0% +then i'm going to talk about some web +based resources for doing some + + align:start position:0% +based resources for doing some + + + align:start position:0% +based resources for doing some +interesting hypothesis generation and + + align:start position:0% +interesting hypothesis generation and + + + align:start position:0% +interesting hypothesis generation and +we'll just end it at that point + + align:start position:0% +we'll just end it at that point + + + align:start position:0% +we'll just end it at that point +so our all you are so not all of you are + + align:start position:0% +so our all you are so not all of you are + + + align:start position:0% +so our all you are so not all of you are +actually in the uh are physicians or + + align:start position:0% +actually in the uh are physicians or + + + align:start position:0% +actually in the uh are physicians or +medical students but nonetheless i'll + + align:start position:0% +medical students but nonetheless i'll + + + align:start position:0% +medical students but nonetheless i'll +present this case of a patient that i + + align:start position:0% +present this case of a patient that i + + + align:start position:0% +present this case of a patient that i +saw okay + + align:start position:0% +saw okay + + + align:start position:0% +saw okay +it's a female presented with acanthosis + + align:start position:0% +it's a female presented with acanthosis + + + align:start position:0% +it's a female presented with acanthosis +nigricans random glucose of 162. so + + align:start position:0% +nigricans random glucose of 162. so + + + align:start position:0% +nigricans random glucose of 162. so +acanthosis niagara fans do you know what + + align:start position:0% +acanthosis niagara fans do you know what + + + align:start position:0% +acanthosis niagara fans do you know what +that is there's a dark patch that you + + align:start position:0% +that is there's a dark patch that you + + + align:start position:0% +that is there's a dark patch that you +can get in the back of your neck and + + align:start position:0% +can get in the back of your neck and + + + align:start position:0% +can get in the back of your neck and +your elbows and your underarms and what + + align:start position:0% +your elbows and your underarms and what + + + align:start position:0% +your elbows and your underarms and what +that means is that your insulin is too + + align:start position:0% +that means is that your insulin is too + + + align:start position:0% +that means is that your insulin is too +high + + align:start position:0% +high + + + align:start position:0% +high +okay because insulin is telling the + + align:start position:0% +okay because insulin is telling the + + + align:start position:0% +okay because insulin is telling the +melanocytes for for some through some + + align:start position:0% +melanocytes for for some through some + + + align:start position:0% +melanocytes for for some through some +unknown mechanism so + + align:start position:0% +unknown mechanism so + + + align:start position:0% +unknown mechanism so +melanocytes become darker + + align:start position:0% +melanocytes become darker + + + align:start position:0% +melanocytes become darker +so you you look just look at people on + + align:start position:0% +so you you look just look at people on + + + align:start position:0% +so you you look just look at people on +the street now and look to see if they + + align:start position:0% +the street now and look to see if they + + + align:start position:0% +the street now and look to see if they +have a dark patch here it's not dirt you + + align:start position:0% +have a dark patch here it's not dirt you + + + align:start position:0% +have a dark patch here it's not dirt you +can't scrub it off but that's a sign of + + align:start position:0% +can't scrub it off but that's a sign of + + + align:start position:0% +can't scrub it off but that's a sign of +acanthosis negative cancer someone's + + align:start position:0% +acanthosis negative cancer someone's + + + align:start position:0% +acanthosis negative cancer someone's +having a problem with insulin and it's + + align:start position:0% +having a problem with insulin and it's + + + align:start position:0% +having a problem with insulin and it's +too high + + align:start position:0% +too high + + + align:start position:0% +too high +did more studies the ldl is sky high i + + align:start position:0% +did more studies the ldl is sky high i + + + align:start position:0% +did more studies the ldl is sky high i +mean ldl is high total cholesterol sky + + align:start position:0% +mean ldl is high total cholesterol sky + + + align:start position:0% +mean ldl is high total cholesterol sky +high triglycerides are very high hdl is + + align:start position:0% +high triglycerides are very high hdl is + + + align:start position:0% +high triglycerides are very high hdl is +low + + align:start position:0% +low + + + align:start position:0% +low +so it's a metabolic syndrome or color + + align:start position:0% +so it's a metabolic syndrome or color + + + align:start position:0% +so it's a metabolic syndrome or color +it's called syndrome x + + align:start position:0% +it's called syndrome x + + + align:start position:0% +it's called syndrome x +fasting glucose 133 that meets criteria + + align:start position:0% +fasting glucose 133 that meets criteria + + + align:start position:0% +fasting glucose 133 that meets criteria +for diabetes insulin is 27 which means + + align:start position:0% +for diabetes insulin is 27 which means + + + align:start position:0% +for diabetes insulin is 27 which means +this is high but this is very high + + align:start position:0% +this is high but this is very high + + + align:start position:0% +this is high but this is very high +bringing that glucose trying to + + align:start position:0% +bringing that glucose trying to + + + align:start position:0% +bringing that glucose trying to +compensate for that hemoglobin a1c is + + align:start position:0% +compensate for that hemoglobin a1c is + + + align:start position:0% +compensate for that hemoglobin a1c is +7.3 the normal range is 4 to 6. + + align:start position:0% +7.3 the normal range is 4 to 6. + + + align:start position:0% +7.3 the normal range is 4 to 6. +and again to drive the whole point home + + align:start position:0% +and again to drive the whole point home + + + align:start position:0% +and again to drive the whole point home +there's a 12 year old girl with adult + + align:start position:0% +there's a 12 year old girl with adult + + + align:start position:0% +there's a 12 year old girl with adult +onset diabetes okay so this is her body + + align:start position:0% +onset diabetes okay so this is her body + + + align:start position:0% +onset diabetes okay so this is her body +mass index + + align:start position:0% +mass index + + + align:start position:0% +mass index +this is a 97th percentile curve and this + + align:start position:0% +this is a 97th percentile curve and this + + + align:start position:0% +this is a 97th percentile curve and this +is where she is well over the curve here + + align:start position:0% +is where she is well over the curve here + + + align:start position:0% +is where she is well over the curve here +and now she has type 2 diabetes she + + align:start position:0% +and now she has type 2 diabetes she + + + align:start position:0% +and now she has type 2 diabetes she +meets criteria for type 2 diabetes she + + align:start position:0% +meets criteria for type 2 diabetes she + + + align:start position:0% +meets criteria for type 2 diabetes she +was not even entering seventh grade when + + align:start position:0% +was not even entering seventh grade when + + + align:start position:0% +was not even entering seventh grade when +i started doing summer vacation last + + align:start position:0% +i started doing summer vacation last + + + align:start position:0% +i started doing summer vacation last +year one in three kids is going to be + + align:start position:0% +year one in three kids is going to be + + + align:start position:0% +year one in three kids is going to be +like this okay that's the problem so one + + align:start position:0% +like this okay that's the problem so one + + + align:start position:0% +like this okay that's the problem so one +way to study this problem is to study + + align:start position:0% +way to study this problem is to study + + + align:start position:0% +way to study this problem is to study +obesity and one way to think about and + + align:start position:0% +obesity and one way to think about and + + + align:start position:0% +obesity and one way to think about and +obesity related to diabetes so one way + + align:start position:0% +obesity related to diabetes so one way + + + align:start position:0% +obesity related to diabetes so one way +to study obesity is to think about the + + align:start position:0% +to study obesity is to think about the + + + align:start position:0% +to study obesity is to think about the +specifically what i'm interested in + + align:start position:0% +specifically what i'm interested in + + + align:start position:0% +specifically what i'm interested in +studying is how adipogenesis + + align:start position:0% +studying is how adipogenesis + + + align:start position:0% +studying is how adipogenesis +or the process of making fat cells might + + align:start position:0% +or the process of making fat cells might + + + align:start position:0% +or the process of making fat cells might +be related to how insulin works + + align:start position:0% +be related to how insulin works + + + align:start position:0% +be related to how insulin works +and the best established way to study + + align:start position:0% +and the best established way to study + + + align:start position:0% +and the best established way to study +that is to look at the insulin receptor + + align:start position:0% +that is to look at the insulin receptor + + + align:start position:0% +that is to look at the insulin receptor +okay so now we're zooming into one of + + align:start position:0% +okay so now we're zooming into one of + + + align:start position:0% +okay so now we're zooming into one of +these target tissues remember liver + + align:start position:0% +these target tissues remember liver + + + align:start position:0% +these target tissues remember liver +muscle and fat and the insulin receptor + + align:start position:0% +muscle and fat and the insulin receptor + + + align:start position:0% +muscle and fat and the insulin receptor +is a protein that sticks in the membrane + + align:start position:0% +is a protein that sticks in the membrane + + + align:start position:0% +is a protein that sticks in the membrane +of the cell okay like any other protein + + align:start position:0% +of the cell okay like any other protein + + + align:start position:0% +of the cell okay like any other protein +it's got a gene coding for it in the dna + + align:start position:0% +it's got a gene coding for it in the dna + + + align:start position:0% +it's got a gene coding for it in the dna +gets transcribed gets translated the + + align:start position:0% +gets transcribed gets translated the + + + align:start position:0% +gets transcribed gets translated the +protein goes out to the surface + + align:start position:0% +protein goes out to the surface + + + align:start position:0% +protein goes out to the surface +there are known mutations in the insulin + + align:start position:0% +there are known mutations in the insulin + + + align:start position:0% +there are known mutations in the insulin +receptor that can cause you to have + + align:start position:0% +receptor that can cause you to have + + + align:start position:0% +receptor that can cause you to have +problems with glucose handling and + + align:start position:0% +problems with glucose handling and + + + align:start position:0% +problems with glucose handling and +diabetes in fact there's a syndrome + + align:start position:0% +diabetes in fact there's a syndrome + + + align:start position:0% +diabetes in fact there's a syndrome +called leprechaunism + + align:start position:0% +called leprechaunism + + + align:start position:0% +called leprechaunism +where these kids look like leprechauns + + align:start position:0% +where these kids look like leprechauns + + + align:start position:0% +where these kids look like leprechauns +actually they die pretty quickly after + + align:start position:0% +actually they die pretty quickly after + + + align:start position:0% +actually they die pretty quickly after +birth but they have mutations in the + + align:start position:0% +birth but they have mutations in the + + + align:start position:0% +birth but they have mutations in the +insulin receptor + + align:start position:0% +insulin receptor + + + align:start position:0% +insulin receptor +it turns out you can actually be born + + align:start position:0% +it turns out you can actually be born + + + align:start position:0% +it turns out you can actually be born +without an insulin receptor there's been + + align:start position:0% +without an insulin receptor there's been + + + align:start position:0% +without an insulin receptor there's been +a null person there's been a one patient + + align:start position:0% +a null person there's been a one patient + + + align:start position:0% +a null person there's been a one patient +i think that was found to have no + + align:start position:0% +i think that was found to have no + + + align:start position:0% +i think that was found to have no +insulin receptors and obviously the + + align:start position:0% +insulin receptors and obviously the + + + align:start position:0% +insulin receptors and obviously the +insulin level was sky high in this baby + + align:start position:0% +insulin level was sky high in this baby + + + align:start position:0% +insulin level was sky high in this baby +at birth because it's not acting + + align:start position:0% +at birth because it's not acting + + + align:start position:0% +at birth because it's not acting +anywhere + + align:start position:0% +anywhere + + + align:start position:0% +anywhere +but what happens is what's supposed to + + align:start position:0% +but what happens is what's supposed to + + + align:start position:0% +but what happens is what's supposed to +happen is insulin binds to the insulin + + align:start position:0% +happen is insulin binds to the insulin + + + align:start position:0% +happen is insulin binds to the insulin +receptor and then these phosphate groups + + align:start position:0% +receptor and then these phosphate groups + + + align:start position:0% +receptor and then these phosphate groups +are added to itself + + align:start position:0% +are added to itself + + + align:start position:0% +are added to itself +and that changes the shape of this + + align:start position:0% +and that changes the shape of this + + + align:start position:0% +and that changes the shape of this +molecule in such a way + + align:start position:0% +molecule in such a way + + + align:start position:0% +molecule in such a way +that it can actually start to interact + + align:start position:0% +that it can actually start to interact + + + align:start position:0% +that it can actually start to interact +with other molecules and in fact the + + align:start position:0% +with other molecules and in fact the + + + align:start position:0% +with other molecules and in fact the +insulin receptor also adds phosphate + + align:start position:0% +insulin receptor also adds phosphate + + + align:start position:0% +insulin receptor also adds phosphate +groups to other things okay in fact + + align:start position:0% +groups to other things okay in fact + + + align:start position:0% +groups to other things okay in fact +these are insulin insulin receptor + + align:start position:0% +these are insulin insulin receptor + + + align:start position:0% +these are insulin insulin receptor +substrate one insulin receptor substrate + + align:start position:0% +substrate one insulin receptor substrate + + + align:start position:0% +substrate one insulin receptor substrate +two three and four and there's some + + align:start position:0% +two three and four and there's some + + + align:start position:0% +two three and four and there's some +others here + + align:start position:0% +others here + + + align:start position:0% +others here +so in collaboration with ron khan + + align:start position:0% +so in collaboration with ron khan + + + align:start position:0% +so in collaboration with ron khan +president of the dawson diabetes center + + align:start position:0% +president of the dawson diabetes center + + + align:start position:0% +president of the dawson diabetes center +he's created some mice where they've + + align:start position:0% +he's created some mice where they've + + + align:start position:0% +he's created some mice where they've +basically knocked out irs one two three + + align:start position:0% +basically knocked out irs one two three + + + align:start position:0% +basically knocked out irs one two three +and four in separate mice so these are + + align:start position:0% +and four in separate mice so these are + + + align:start position:0% +and four in separate mice so these are +otherwise normal mice missing this one + + align:start position:0% +otherwise normal mice missing this one + + + align:start position:0% +otherwise normal mice missing this one +particular gene + + align:start position:0% +particular gene + + + align:start position:0% +particular gene +if you take fat cells from these mice + + align:start position:0% +if you take fat cells from these mice + + + align:start position:0% +if you take fat cells from these mice +and trus in fact if you take pre-fat + + align:start position:0% +and trus in fact if you take pre-fat + + + align:start position:0% +and trus in fact if you take pre-fat +cells or pre-adipocytes + + align:start position:0% +cells or pre-adipocytes + + + align:start position:0% +cells or pre-adipocytes +you can make them go into fat cells + + align:start position:0% +you can make them go into fat cells + + + align:start position:0% +you can make them go into fat cells +using a standard cocktail of hormones + + align:start position:0% +using a standard cocktail of hormones + + + align:start position:0% +using a standard cocktail of hormones +okay this has been done for the past two + + align:start position:0% +okay this has been done for the past two + + + align:start position:0% +okay this has been done for the past two +decades you take three pre-fat cells and + + align:start position:0% +decades you take three pre-fat cells and + + + align:start position:0% +decades you take three pre-fat cells and +make them into fat cells with a + + align:start position:0% +make them into fat cells with a + + + align:start position:0% +make them into fat cells with a +particular cocktail and what happens is + + align:start position:0% +particular cocktail and what happens is + + + align:start position:0% +particular cocktail and what happens is +if you take normal pre-fat cells and + + align:start position:0% +if you take normal pre-fat cells and + + + align:start position:0% +if you take normal pre-fat cells and +make them into fat cells and stain for + + align:start position:0% +make them into fat cells and stain for + + + align:start position:0% +make them into fat cells and stain for +the fat or the lipid you get a big red + + align:start position:0% +the fat or the lipid you get a big red + + + align:start position:0% +the fat or the lipid you get a big red +circle here this is a dish of the cells + + align:start position:0% +circle here this is a dish of the cells + + + align:start position:0% +circle here this is a dish of the cells +if you knock out irs1 and try to do this + + align:start position:0% +if you knock out irs1 and try to do this + + + align:start position:0% +if you knock out irs1 and try to do this +you cannot get the fat cells to form so + + align:start position:0% +you cannot get the fat cells to form so + + + align:start position:0% +you cannot get the fat cells to form so +again pre-fat cells the same cocktail + + align:start position:0% +again pre-fat cells the same cocktail + + + align:start position:0% +again pre-fat cells the same cocktail +you don't get fat cells in the end + + align:start position:0% +you don't get fat cells in the end + + + align:start position:0% +you don't get fat cells in the end +there's no stain there's barely a stain + + align:start position:0% +there's no stain there's barely a stain + + + align:start position:0% +there's no stain there's barely a stain +for any red here and it turns out if you + + align:start position:0% +for any red here and it turns out if you + + + align:start position:0% +for any red here and it turns out if you +knock out iris three two and four in the + + align:start position:0% +knock out iris three two and four in the + + + align:start position:0% +knock out iris three two and four in the +middle here you get a gradation of the + + align:start position:0% +middle here you get a gradation of the + + + align:start position:0% +middle here you get a gradation of the +phenotype interestingly + + align:start position:0% +phenotype interestingly + + + align:start position:0% +phenotype interestingly +so it's not all or none these are if you + + align:start position:0% +so it's not all or none these are if you + + + align:start position:0% +so it's not all or none these are if you +knock out the other irs molecules you + + align:start position:0% +knock out the other irs molecules you + + + align:start position:0% +knock out the other irs molecules you +get a gradation of the phenotype + + align:start position:0% +get a gradation of the phenotype + + + align:start position:0% +get a gradation of the phenotype +curiously + + align:start position:0% +curiously + + + align:start position:0% +curiously +so what we did is in collaboration with + + align:start position:0% +so what we did is in collaboration with + + + align:start position:0% +so what we did is in collaboration with +ron khan we actually made a list of + + align:start position:0% +ron khan we actually made a list of + + + align:start position:0% +ron khan we actually made a list of +genes that behaved in this pattern okay + + align:start position:0% +genes that behaved in this pattern okay + + + align:start position:0% +genes that behaved in this pattern okay +now we don't have numbers here right but + + align:start position:0% +now we don't have numbers here right but + + + align:start position:0% +now we don't have numbers here right but +we're just trying to find genes that go + + align:start position:0% +we're just trying to find genes that go + + + align:start position:0% +we're just trying to find genes that go +along with that pattern so let me show + + align:start position:0% +along with that pattern so let me show + + + align:start position:0% +along with that pattern so let me show +you an example one of these things + + align:start position:0% +you an example one of these things + + + align:start position:0% +you an example one of these things +here's a gene here's wild type one + + align:start position:0% +here's a gene here's wild type one + + + align:start position:0% +here's a gene here's wild type one +here's wild type here's irs one knockout + + align:start position:0% +here's wild type here's irs one knockout + + + align:start position:0% +here's wild type here's irs one knockout +so no fat cells + + align:start position:0% +so no fat cells + + + align:start position:0% +so no fat cells +easy to make fat cells and we're taking + + align:start position:0% +easy to make fat cells and we're taking + + + align:start position:0% +easy to make fat cells and we're taking +the genes + + align:start position:0% +the genes + + + align:start position:0% +the genes +we're taking rna before we try to make + + align:start position:0% +we're taking rna before we try to make + + + align:start position:0% +we're taking rna before we try to make +them into fat cells okay the hypothesis + + align:start position:0% +them into fat cells okay the hypothesis + + + align:start position:0% +them into fat cells okay the hypothesis +here is + + align:start position:0% +here is + + + align:start position:0% +here is +what genes are different + + align:start position:0% +what genes are different + + + align:start position:0% +what genes are different +before we try to make them into fat + + align:start position:0% +before we try to make them into fat + + + align:start position:0% +before we try to make them into fat +cells that might be impacting the + + align:start position:0% +cells that might be impacting the + + + align:start position:0% +cells that might be impacting the +process of making fat cells + + align:start position:0% +process of making fat cells + + + align:start position:0% +process of making fat cells +okay + + align:start position:0% +okay + + + align:start position:0% +okay +now i'm going to take a second here i'm + + align:start position:0% +now i'm going to take a second here i'm + + + align:start position:0% +now i'm going to take a second here i'm +going to you're probably asking wait + + align:start position:0% +going to you're probably asking wait + + + align:start position:0% +going to you're probably asking wait +we're just talking about humans we're + + align:start position:0% +we're just talking about humans we're + + + align:start position:0% +we're just talking about humans we're +just talking about this kid that was + + align:start position:0% +just talking about this kid that was + + + align:start position:0% +just talking about this kid that was +obese and now we're talking about mice + + align:start position:0% +obese and now we're talking about mice + + + align:start position:0% +obese and now we're talking about mice +here okay i'm going to bring this back + + align:start position:0% +here okay i'm going to bring this back + + + align:start position:0% +here okay i'm going to bring this back +to the humans in a minute okay + + align:start position:0% +to the humans in a minute okay + + + align:start position:0% +to the humans in a minute okay +because i'm going to intersect this with + + align:start position:0% +because i'm going to intersect this with + + + align:start position:0% +because i'm going to intersect this with +other data sets and show you where i'm + + align:start position:0% +other data sets and show you where i'm + + + align:start position:0% +other data sets and show you where i'm +going + + align:start position:0% +going + + + align:start position:0% +going +but suffice it to say we have about 80 + + align:start position:0% +but suffice it to say we have about 80 + + + align:start position:0% +but suffice it to say we have about 80 +genes that follow this kind of pattern + + align:start position:0% +genes that follow this kind of pattern + + + align:start position:0% +genes that follow this kind of pattern +they're high + + align:start position:0% +they're high + + + align:start position:0% +they're high +in the normals they're low in the irs1 + + align:start position:0% +in the normals they're low in the irs1 + + + align:start position:0% +in the normals they're low in the irs1 +knockouts before adipogenesis and + + align:start position:0% +knockouts before adipogenesis and + + + align:start position:0% +knockouts before adipogenesis and +they're in this kind of monotonic + + align:start position:0% +they're in this kind of monotonic + + + align:start position:0% +they're in this kind of monotonic +pattern here or vice versa going down or + + align:start position:0% +pattern here or vice versa going down or + + + align:start position:0% +pattern here or vice versa going down or +up came up with listed about 88 genes + + align:start position:0% +up came up with listed about 88 genes + + + align:start position:0% +up came up with listed about 88 genes +that fit this kind of pattern + + align:start position:0% +that fit this kind of pattern + + + align:start position:0% +that fit this kind of pattern +now put those 88 genes + + align:start position:0% +now put those 88 genes + + + align:start position:0% +now put those 88 genes +on hold for a second + + align:start position:0% +on hold for a second + + + align:start position:0% +on hold for a second +let's talk about second disease + + align:start position:0% +let's talk about second disease + + + align:start position:0% +let's talk about second disease +i have been involved studying this + + align:start position:0% +i have been involved studying this + + + align:start position:0% +i have been involved studying this +particular syndrome called progeria + + align:start position:0% +particular syndrome called progeria + + + align:start position:0% +particular syndrome called progeria +progeria's advanced aging syndrome in + + align:start position:0% +progeria's advanced aging syndrome in + + + align:start position:0% +progeria's advanced aging syndrome in +children in fact it makes it very rare + + align:start position:0% +children in fact it makes it very rare + + + align:start position:0% +children in fact it makes it very rare +it's about one in eight million births + + align:start position:0% +it's about one in eight million births + + + align:start position:0% +it's about one in eight million births +and makes children look like they're + + align:start position:0% +and makes children look like they're + + + align:start position:0% +and makes children look like they're +getting older okay we've all heard of + + align:start position:0% +getting older okay we've all heard of + + + align:start position:0% +getting older okay we've all heard of +these kids and these this kind of story + + align:start position:0% +these kids and these this kind of story + + + align:start position:0% +these kids and these this kind of story +and specifically they lose their hair + + align:start position:0% +and specifically they lose their hair + + + align:start position:0% +and specifically they lose their hair +they have alopecia they're certainly + + align:start position:0% +they have alopecia they're certainly + + + align:start position:0% +they have alopecia they're certainly +short they're shorter than age-matched + + align:start position:0% +short they're shorter than age-matched + + + align:start position:0% +short they're shorter than age-matched +kids they have these skin changes that + + align:start position:0% +kids they have these skin changes that + + + align:start position:0% +kids they have these skin changes that +make them look old they don't go through + + align:start position:0% +make them look old they don't go through + + + align:start position:0% +make them look old they don't go through +puberty they have poor weight gain + + align:start position:0% +puberty they have poor weight gain + + + align:start position:0% +puberty they have poor weight gain +and usually they die at age 15 because + + align:start position:0% +and usually they die at age 15 because + + + align:start position:0% +and usually they die at age 15 because +of cardiovascular problems + + align:start position:0% +of cardiovascular problems + + + align:start position:0% +of cardiovascular problems +atherosclerosis gets strokes they get + + align:start position:0% +atherosclerosis gets strokes they get + + + align:start position:0% +atherosclerosis gets strokes they get +heart attacks now even though they look + + align:start position:0% +heart attacks now even though they look + + + align:start position:0% +heart attacks now even though they look +older + + align:start position:0% +older + + + align:start position:0% +older +they don't get everything associated + + align:start position:0% +they don't get everything associated + + + align:start position:0% +they don't get everything associated +with being old they don't get + + align:start position:0% +with being old they don't get + + + align:start position:0% +with being old they don't get +alzheimer's they don't get cancer + + align:start position:0% +alzheimer's they don't get cancer + + + align:start position:0% +alzheimer's they don't get cancer +it's only the atherosclerosis and these + + align:start position:0% +it's only the atherosclerosis and these + + + align:start position:0% +it's only the atherosclerosis and these +other changes here that they get + + align:start position:0% +other changes here that they get + + + align:start position:0% +other changes here that they get +now as you might know the gene for this + + align:start position:0% +now as you might know the gene for this + + + align:start position:0% +now as you might know the gene for this +was just recently discovered okay + + align:start position:0% +was just recently discovered okay + + + align:start position:0% +was just recently discovered okay +very amazing that they found this gene + + align:start position:0% +very amazing that they found this gene + + + align:start position:0% +very amazing that they found this gene +okay i got involved with this particular + + align:start position:0% +okay i got involved with this particular + + + align:start position:0% +okay i got involved with this particular +syndrome only because of my friend + + align:start position:0% +syndrome only because of my friend + + + align:start position:0% +syndrome only because of my friend +leslie gordon who was a medical school + + align:start position:0% +leslie gordon who was a medical school + + + align:start position:0% +leslie gordon who was a medical school +classmate of mine and who has a son with + + align:start position:0% +classmate of mine and who has a son with + + + align:start position:0% +classmate of mine and who has a son with +this + + align:start position:0% +this + + + align:start position:0% +this +and she's got an mvp she instead of just + + align:start position:0% +and she's got an mvp she instead of just + + + align:start position:0% +and she's got an mvp she instead of just +studying this disease herself she built + + align:start position:0% +studying this disease herself she built + + + align:start position:0% +studying this disease herself she built +a + + align:start position:0% +a + + + align:start position:0% +a +foundation called the progeria research + + align:start position:0% +foundation called the progeria research + + + align:start position:0% +foundation called the progeria research +foundation got francis collins + + align:start position:0% +foundation got francis collins + + + align:start position:0% +foundation got francis collins +interested you know the guy who's + + align:start position:0% +interested you know the guy who's + + + align:start position:0% +interested you know the guy who's +basically doing the genome project the + + align:start position:0% +basically doing the genome project the + + + align:start position:0% +basically doing the genome project the +head of nhgri and within 18 months of + + align:start position:0% +head of nhgri and within 18 months of + + + align:start position:0% +head of nhgri and within 18 months of +forming this foundation they found the + + align:start position:0% +forming this foundation they found the + + + align:start position:0% +forming this foundation they found the +gene for this + + align:start position:0% +gene for this + + + align:start position:0% +gene for this +incredibly difficult problem okay there + + align:start position:0% +incredibly difficult problem okay there + + + align:start position:0% +incredibly difficult problem okay there +are people who on the first date would + + align:start position:0% +are people who on the first date would + + + align:start position:0% +are people who on the first date would +not believe this is still a genetic + + align:start position:0% +not believe this is still a genetic + + + align:start position:0% +not believe this is still a genetic +syndrome + + align:start position:0% +syndrome + + + align:start position:0% +syndrome +one in eight million births is way less + + align:start position:0% +one in eight million births is way less + + + align:start position:0% +one in eight million births is way less +than the mutation frequency + + align:start position:0% +than the mutation frequency + + + align:start position:0% +than the mutation frequency +okay i mean we have a whole bunch of + + align:start position:0% +okay i mean we have a whole bunch of + + + align:start position:0% +okay i mean we have a whole bunch of +diseases that at one forty thousand one + + align:start position:0% +diseases that at one forty thousand one + + + align:start position:0% +diseases that at one forty thousand one +in a hundred thousand + + align:start position:0% +in a hundred thousand + + + align:start position:0% +in a hundred thousand +one eight million seems like it's so + + align:start position:0% +one eight million seems like it's so + + + align:start position:0% +one eight million seems like it's so +rare how where how could a mutation be + + align:start position:0% +rare how where how could a mutation be + + + align:start position:0% +rare how where how could a mutation be +that rare so it was very questionable + + align:start position:0% +that rare so it was very questionable + + + align:start position:0% +that rare so it was very questionable +and second they had a very hard time + + align:start position:0% +and second they had a very hard time + + + align:start position:0% +and second they had a very hard time +finding any families where two of these + + align:start position:0% +finding any families where two of these + + + align:start position:0% +finding any families where two of these +kids were in the same family + + align:start position:0% +kids were in the same family + + + align:start position:0% +kids were in the same family +so it was dumb luck that they were able + + align:start position:0% +so it was dumb luck that they were able + + + align:start position:0% +so it was dumb luck that they were able +to find this gene because in one of the + + align:start position:0% +to find this gene because in one of the + + + align:start position:0% +to find this gene because in one of the +individuals okay at any point there's + + align:start position:0% +individuals okay at any point there's + + + align:start position:0% +individuals okay at any point there's +only about 50 of these kids on the + + align:start position:0% +only about 50 of these kids on the + + + align:start position:0% +only about 50 of these kids on the +planet really okay and one of these kids + + align:start position:0% +planet really okay and one of these kids + + + align:start position:0% +planet really okay and one of these kids +in one of the samples someone with a + + align:start position:0% +in one of the samples someone with a + + + align:start position:0% +in one of the samples someone with a +sharp eye saw a piece of chromosome 1 + + align:start position:0% +sharp eye saw a piece of chromosome 1 + + + align:start position:0% +sharp eye saw a piece of chromosome 1 +was actually inverted the bands those + + align:start position:0% +was actually inverted the bands those + + + align:start position:0% +was actually inverted the bands those +banding patterns was actually different + + align:start position:0% +banding patterns was actually different + + + align:start position:0% +banding patterns was actually different +in that one individual + + align:start position:0% +in that one individual + + + align:start position:0% +in that one individual +and that got francis collins to think + + align:start position:0% +and that got francis collins to think + + + align:start position:0% +and that got francis collins to think +maybe it's something on that particular + + align:start position:0% +maybe it's something on that particular + + + align:start position:0% +maybe it's something on that particular +arm of chromosome 1 and they sequence + + align:start position:0% +arm of chromosome 1 and they sequence + + + align:start position:0% +arm of chromosome 1 and they sequence +all the genes there and they found the + + align:start position:0% +all the genes there and they found the + + + align:start position:0% +all the genes there and they found the +particular mutation machine called lamin + + align:start position:0% +particular mutation machine called lamin + + + align:start position:0% +particular mutation machine called lamin +a + + align:start position:0% +a + + + align:start position:0% +a +and it's not just laminate that causes + + align:start position:0% +and it's not just laminate that causes + + + align:start position:0% +and it's not just laminate that causes +it vitamin a has actually been involved + + align:start position:0% +it vitamin a has actually been involved + + + align:start position:0% +it vitamin a has actually been involved +in a lot of other diseases which we'll + + align:start position:0% +in a lot of other diseases which we'll + + + align:start position:0% +in a lot of other diseases which we'll +talk about in a second it's just this + + align:start position:0% +talk about in a second it's just this + + + align:start position:0% +talk about in a second it's just this +one mutation in this one gene that + + align:start position:0% +one mutation in this one gene that + + + align:start position:0% +one mutation in this one gene that +causes it + + align:start position:0% +causes it + + + align:start position:0% +causes it +now amazingly enough in the same issue + + align:start position:0% +now amazingly enough in the same issue + + + align:start position:0% +now amazingly enough in the same issue +of nature + + align:start position:0% +of nature + + + align:start position:0% +of nature +less than a year ago + + align:start position:0% +less than a year ago + + + align:start position:0% +less than a year ago +the mouse model for this was published + + align:start position:0% +the mouse model for this was published + + + align:start position:0% +the mouse model for this was published +how is that okay because this group at + + align:start position:0% +how is that okay because this group at + + + align:start position:0% +how is that okay because this group at +national cancer institute + + align:start position:0% +national cancer institute + + + align:start position:0% +national cancer institute +realized i mean lemon a is known to be + + align:start position:0% +realized i mean lemon a is known to be + + + align:start position:0% +realized i mean lemon a is known to be +involved in certain forms of muscular + + align:start position:0% +involved in certain forms of muscular + + + align:start position:0% +involved in certain forms of muscular +dystrophy they said well + + align:start position:0% +dystrophy they said well + + + align:start position:0% +dystrophy they said well +they wanted to create a mouse model of a + + align:start position:0% +they wanted to create a mouse model of a + + + align:start position:0% +they wanted to create a mouse model of a +particular form of muscular dystrophy + + align:start position:0% +particular form of muscular dystrophy + + + align:start position:0% +particular form of muscular dystrophy +they accidentally created a mouse model + + align:start position:0% +they accidentally created a mouse model + + + align:start position:0% +they accidentally created a mouse model +for progeria + + align:start position:0% +for progeria + + + align:start position:0% +for progeria +so the same issue you got the gene that + + align:start position:0% +so the same issue you got the gene that + + + align:start position:0% +so the same issue you got the gene that +causes it you got diagnostic tests and + + align:start position:0% +causes it you got diagnostic tests and + + + align:start position:0% +causes it you got diagnostic tests and +you got a mouse model to study it okay + + align:start position:0% +you got a mouse model to study it okay + + + align:start position:0% +you got a mouse model to study it okay +and just in a tour de force issue there + + align:start position:0% +and just in a tour de force issue there + + + align:start position:0% +and just in a tour de force issue there +okay + + align:start position:0% +okay + + + align:start position:0% +okay +imagine how long it takes for these + + align:start position:0% +imagine how long it takes for these + + + align:start position:0% +imagine how long it takes for these +things to happen for a disease + + align:start position:0% +things to happen for a disease + + + align:start position:0% +things to happen for a disease +start to finish 18 months here okay for + + align:start position:0% +start to finish 18 months here okay for + + + align:start position:0% +start to finish 18 months here okay for +something that affects maybe 50 people + + align:start position:0% +something that affects maybe 50 people + + + align:start position:0% +something that affects maybe 50 people +okay so if you put your mind to it you + + align:start position:0% +okay so if you put your mind to it you + + + align:start position:0% +okay so if you put your mind to it you +can solve these diseases it's amazing + + align:start position:0% +can solve these diseases it's amazing + + + align:start position:0% +can solve these diseases it's amazing +what the tools and the people can do + + align:start position:0% +what the tools and the people can do + + + align:start position:0% +what the tools and the people can do +today + + align:start position:0% +today + + + align:start position:0% +today +so in collaboration with the progeria + + align:start position:0% +so in collaboration with the progeria + + + align:start position:0% +so in collaboration with the progeria +foundation what we've done is this it + + align:start position:0% +foundation what we've done is this it + + + align:start position:0% +foundation what we've done is this it +turns out over the past 20 years when + + align:start position:0% +turns out over the past 20 years when + + + align:start position:0% +turns out over the past 20 years when +people thought they had kids with + + align:start position:0% +people thought they had kids with + + + align:start position:0% +people thought they had kids with +progeria that they were trying to treat + + align:start position:0% +progeria that they were trying to treat + + + align:start position:0% +progeria that they were trying to treat +kids with progeria they had no idea what + + align:start position:0% +kids with progeria they had no idea what + + + align:start position:0% +kids with progeria they had no idea what +to do so one thing they did is they took + + align:start position:0% +to do so one thing they did is they took + + + align:start position:0% +to do so one thing they did is they took +fibroblasts and they saved them in + + align:start position:0% +fibroblasts and they saved them in + + + align:start position:0% +fibroblasts and they saved them in +national repositories + + align:start position:0% +national repositories + + + align:start position:0% +national repositories +so there's a cor there's a cell + + align:start position:0% +so there's a cor there's a cell + + + align:start position:0% +so there's a cor there's a cell +repository called the corial cell + + align:start position:0% +repository called the corial cell + + + align:start position:0% +repository called the corial cell +repository where you can order + + align:start position:0% +repository where you can order + + + align:start position:0% +repository where you can order +fibroblast cell lines from patients with + + align:start position:0% +fibroblast cell lines from patients with + + + align:start position:0% +fibroblast cell lines from patients with +exceedingly rare disorders including + + align:start position:0% +exceedingly rare disorders including + + + align:start position:0% +exceedingly rare disorders including +progeria + + align:start position:0% +progeria + + + align:start position:0% +progeria +so we've gotten three cell lines from + + align:start position:0% +so we've gotten three cell lines from + + + align:start position:0% +so we've gotten three cell lines from +patients that were stored in the coriol + + align:start position:0% +patients that were stored in the coriol + + + align:start position:0% +patients that were stored in the coriol +collection over the past 10 years + + align:start position:0% +collection over the past 10 years + + + align:start position:0% +collection over the past 10 years +and we ordered them three times to make + + align:start position:0% +and we ordered them three times to make + + + align:start position:0% +and we ordered them three times to make +sure that we're controlling at least for + + align:start position:0% +sure that we're controlling at least for + + + align:start position:0% +sure that we're controlling at least for +passage number and things like that and + + align:start position:0% +passage number and things like that and + + + align:start position:0% +passage number and things like that and +we compare them to age match normal + + align:start position:0% +we compare them to age match normal + + + align:start position:0% +we compare them to age match normal +fibroblasts from the same coriol + + align:start position:0% +fibroblasts from the same coriol + + + align:start position:0% +fibroblasts from the same coriol +repository look at what genes are + + align:start position:0% +repository look at what genes are + + + align:start position:0% +repository look at what genes are +different between progeria and + + align:start position:0% +different between progeria and + + + align:start position:0% +different between progeria and +non-progeria + + align:start position:0% +non-progeria + + + align:start position:0% +non-progeria +and these are more up-to-date arrays + + align:start position:0% +and these are more up-to-date arrays + + + align:start position:0% +and these are more up-to-date arrays +there's a u-133 race on two the whole + + align:start position:0% +there's a u-133 race on two the whole + + + align:start position:0% +there's a u-133 race on two the whole +genome with two chips it gave us about + + align:start position:0% +genome with two chips it gave us about + + + align:start position:0% +genome with two chips it gave us about +33 000 genes and used a particular + + align:start position:0% +33 000 genes and used a particular + + + align:start position:0% +33 000 genes and used a particular +analytic technique and we got about a + + align:start position:0% +analytic technique and we got about a + + + align:start position:0% +analytic technique and we got about a +list of about 366 genes that were + + align:start position:0% +list of about 366 genes that were + + + align:start position:0% +list of about 366 genes that were +different between fibroblasts in + + align:start position:0% +different between fibroblasts in + + + align:start position:0% +different between fibroblasts in +progeria and fibroblasts from age match + + align:start position:0% +progeria and fibroblasts from age match + + + align:start position:0% +progeria and fibroblasts from age match +controls + + align:start position:0% +controls + + + align:start position:0% +controls +okay + + align:start position:0% + + + + align:start position:0% + +and so if you look at where these genes + + align:start position:0% +and so if you look at where these genes + + + align:start position:0% +and so if you look at where these genes +are what categories they're involved + + align:start position:0% +are what categories they're involved + + + align:start position:0% +are what categories they're involved +with you see interesting things like + + align:start position:0% +with you see interesting things like + + + align:start position:0% +with you see interesting things like +development signal transduction cell + + align:start position:0% +development signal transduction cell + + + align:start position:0% +development signal transduction cell +adhesion the only thing i want to point + + align:start position:0% +adhesion the only thing i want to point + + + align:start position:0% +adhesion the only thing i want to point +out is this okay these tables are made + + align:start position:0% +out is this okay these tables are made + + + align:start position:0% +out is this okay these tables are made +using a catalog called gene ontology + + align:start position:0% +using a catalog called gene ontology + + + align:start position:0% +using a catalog called gene ontology +you're going to learn about that in more + + align:start position:0% +you're going to learn about that in more + + + align:start position:0% +you're going to learn about that in more +in the future + + align:start position:0% +in the future + + + align:start position:0% +in the future +and every week or every other week the + + align:start position:0% +and every week or every other week the + + + align:start position:0% +and every week or every other week the +list of known properties of genes and + + align:start position:0% +list of known properties of genes and + + + align:start position:0% +list of known properties of genes and +proteins gets updated + + align:start position:0% +proteins gets updated + + + align:start position:0% +proteins gets updated +but still the majority of genes + + align:start position:0% +but still the majority of genes + + + align:start position:0% +but still the majority of genes +unclassified 161 okay no matter how + + align:start position:0% +unclassified 161 okay no matter how + + + align:start position:0% +unclassified 161 okay no matter how +interesting or how comprehensive we + + align:start position:0% +interesting or how comprehensive we + + + align:start position:0% +interesting or how comprehensive we +think gene ontology is the vast majority + + align:start position:0% +think gene ontology is the vast majority + + + align:start position:0% +think gene ontology is the vast majority +of genes are just have no i we have no + + align:start position:0% +of genes are just have no i we have no + + + align:start position:0% +of genes are just have no i we have no +idea where they are what they do what + + align:start position:0% +idea where they are what they do what + + + align:start position:0% +idea where they are what they do what +roles they play + + align:start position:0% +roles they play + + + align:start position:0% +roles they play +these are where the proteins that + + align:start position:0% +these are where the proteins that + + + align:start position:0% +these are where the proteins that +they're coding for actually are take + + align:start position:0% +they're coding for actually are take + + + align:start position:0% +they're coding for actually are take +place + + align:start position:0% +place + + + align:start position:0% +place +nucleus membrane unclassified 131 again + + align:start position:0% +nucleus membrane unclassified 131 again + + + align:start position:0% +nucleus membrane unclassified 131 again +no idea where these proteins even are in + + align:start position:0% +no idea where these proteins even are in + + + align:start position:0% +no idea where these proteins even are in +the cell that's life today okay we have + + align:start position:0% +the cell that's life today okay we have + + + align:start position:0% +the cell that's life today okay we have +a great taxonomy here of all of these + + align:start position:0% +a great taxonomy here of all of these + + + align:start position:0% +a great taxonomy here of all of these +terms and structure vocabulary but we + + align:start position:0% +terms and structure vocabulary but we + + + align:start position:0% +terms and structure vocabulary but we +have no there's very little data for + + align:start position:0% +have no there's very little data for + + + align:start position:0% +have no there's very little data for +most genes in this still + + align:start position:0% + + + + align:start position:0% + +and there's a bunch of genes that were + + align:start position:0% +and there's a bunch of genes that were + + + align:start position:0% +and there's a bunch of genes that were +upregulated that seem to already be + + align:start position:0% +upregulated that seem to already be + + + align:start position:0% +upregulated that seem to already be +known to play a role in atherosclerosis + + align:start position:0% +known to play a role in atherosclerosis + + + align:start position:0% +known to play a role in atherosclerosis +okay so this paper again talk about + + align:start position:0% +okay so this paper again talk about + + + align:start position:0% +okay so this paper again talk about +genome medicine this paper is going to + + align:start position:0% +genome medicine this paper is going to + + + align:start position:0% +genome medicine this paper is going to +end with this list + + align:start position:0% +end with this list + + + align:start position:0% +end with this list +only because a number of these are + + align:start position:0% +only because a number of these are + + + align:start position:0% +only because a number of these are +targets and pharmaceutical companies + + align:start position:0% +targets and pharmaceutical companies + + + align:start position:0% +targets and pharmaceutical companies +actually have drugs against a number of + + align:start position:0% +actually have drugs against a number of + + + align:start position:0% +actually have drugs against a number of +these already + + align:start position:0% +these already + + + align:start position:0% +these already +for kids with progeria it's basically a + + align:start position:0% +for kids with progeria it's basically a + + + align:start position:0% +for kids with progeria it's basically a +death sentence today we have no + + align:start position:0% +death sentence today we have no + + + align:start position:0% +death sentence today we have no +medicines we have not we treat them with + + align:start position:0% +medicines we have not we treat them with + + + align:start position:0% +medicines we have not we treat them with +nothing today there's maybe some people + + align:start position:0% +nothing today there's maybe some people + + + align:start position:0% +nothing today there's maybe some people +treat one or two kids with growth + + align:start position:0% +treat one or two kids with growth + + + align:start position:0% +treat one or two kids with growth +hormone to see if growth hormone does + + align:start position:0% +hormone to see if growth hormone does + + + align:start position:0% +hormone to see if growth hormone does +something but that's basically like a + + align:start position:0% +something but that's basically like a + + + align:start position:0% +something but that's basically like a +voodoo medicine kind of thing we have no + + align:start position:0% +voodoo medicine kind of thing we have no + + + align:start position:0% +voodoo medicine kind of thing we have no +proof of that doing anything + + align:start position:0% +proof of that doing anything + + + align:start position:0% +proof of that doing anything +now we can at least get to some + + align:start position:0% +now we can at least get to some + + + align:start position:0% +now we can at least get to some +information to possibly even think about + + align:start position:0% +information to possibly even think about + + + align:start position:0% +information to possibly even think about +clinical trials here + + align:start position:0% +clinical trials here + + + align:start position:0% +clinical trials here +but let's be let's be frank here these + + align:start position:0% +but let's be let's be frank here these + + + align:start position:0% +but let's be let's be frank here these +were fibroblasts that were frozen for + + align:start position:0% +were fibroblasts that were frozen for + + + align:start position:0% +were fibroblasts that were frozen for +years in the cell repository and we're + + align:start position:0% +years in the cell repository and we're + + + align:start position:0% +years in the cell repository and we're +now we're making a claim as to what + + align:start position:0% +now we're making a claim as to what + + + align:start position:0% +now we're making a claim as to what +their blood vessels look like not just + + align:start position:0% +their blood vessels look like not just + + + align:start position:0% +their blood vessels look like not just +their blood vessels but the intima of + + align:start position:0% +their blood vessels but the intima of + + + align:start position:0% +their blood vessels but the intima of +their blood vessels right this is not + + align:start position:0% +their blood vessels right this is not + + + align:start position:0% +their blood vessels right this is not +the same cell but fiberglass might have + + align:start position:0% +the same cell but fiberglass might have + + + align:start position:0% +the same cell but fiberglass might have +been taken from their cheek + + align:start position:0% +been taken from their cheek + + + align:start position:0% +been taken from their cheek +right but we're just making a claim here + + align:start position:0% +right but we're just making a claim here + + + align:start position:0% +right but we're just making a claim here +because we don't have access to the real + + align:start position:0% +because we don't have access to the real + + + align:start position:0% +because we don't have access to the real +tissue + + align:start position:0% + + + + align:start position:0% + +so one of the reasons why i'm mentioning + + align:start position:0% +so one of the reasons why i'm mentioning + + + align:start position:0% +so one of the reasons why i'm mentioning +progeria here is remember that picture + + align:start position:0% +progeria here is remember that picture + + + align:start position:0% +progeria here is remember that picture +you just saw one of the ways that these + + align:start position:0% +you just saw one of the ways that these + + + align:start position:0% +you just saw one of the ways that these +kids get diagnosed is because by the + + align:start position:0% +kids get diagnosed is because by the + + + align:start position:0% +kids get diagnosed is because by the +time they get to age two they start to + + align:start position:0% +time they get to age two they start to + + + align:start position:0% +time they get to age two they start to +lose their hair but even more + + align:start position:0% +lose their hair but even more + + + align:start position:0% +lose their hair but even more +interestingly is they lose all their fat + + align:start position:0% +interestingly is they lose all their fat + + + align:start position:0% +interestingly is they lose all their fat +cells + + align:start position:0% +cells + + + align:start position:0% +cells +okay it turns out in progeria you lose + + align:start position:0% +okay it turns out in progeria you lose + + + align:start position:0% +okay it turns out in progeria you lose +all your subcutaneous fat + + align:start position:0% +all your subcutaneous fat + + + align:start position:0% +all your subcutaneous fat +and by death and autopsy it's very tough + + align:start position:0% +and by death and autopsy it's very tough + + + align:start position:0% +and by death and autopsy it's very tough +to find any fat in the body + + align:start position:0% +to find any fat in the body + + + align:start position:0% +to find any fat in the body +okay + + align:start position:0% +okay + + + align:start position:0% +okay +makes you think something is up with the + + align:start position:0% +makes you think something is up with the + + + align:start position:0% +makes you think something is up with the +actual process of making fat cells in + + align:start position:0% +actual process of making fat cells in + + + align:start position:0% +actual process of making fat cells in +these kids + + align:start position:0% +these kids + + + align:start position:0% +these kids +in one study these kids have been known + + align:start position:0% +in one study these kids have been known + + + align:start position:0% +in one study these kids have been known +to have some insulin resistance but it's + + align:start position:0% +to have some insulin resistance but it's + + + align:start position:0% +to have some insulin resistance but it's +just one study almost 10 years ago + + align:start position:0% +just one study almost 10 years ago + + + align:start position:0% +just one study almost 10 years ago +and the mouse model the last paragraph + + align:start position:0% +and the mouse model the last paragraph + + + align:start position:0% +and the mouse model the last paragraph +of that nature paper says that they saw + + align:start position:0% +of that nature paper says that they saw + + + align:start position:0% +of that nature paper says that they saw +some process where muscle was + + align:start position:0% +some process where muscle was + + + align:start position:0% +some process where muscle was +redifferentiating the fat basically + + align:start position:0% +redifferentiating the fat basically + + + align:start position:0% +redifferentiating the fat basically +there's some developmental problem going + + align:start position:0% +there's some developmental problem going + + + align:start position:0% +there's some developmental problem going +on but it's not very clear + + align:start position:0% +on but it's not very clear + + + align:start position:0% +on but it's not very clear +other mutations in lamin a cause + + align:start position:0% +other mutations in lamin a cause + + + align:start position:0% +other mutations in lamin a cause +lipodystrophy which is a syndrome where + + align:start position:0% +lipodystrophy which is a syndrome where + + + align:start position:0% +lipodystrophy which is a syndrome where +you lose all your fat cells + + align:start position:0% +you lose all your fat cells + + + align:start position:0% +you lose all your fat cells +so it makes us think that there is + + align:start position:0% +so it makes us think that there is + + + align:start position:0% +so it makes us think that there is +legitimately something wrong with fat + + align:start position:0% +legitimately something wrong with fat + + + align:start position:0% +legitimately something wrong with fat +cell development in kids with progeria + + align:start position:0% +cell development in kids with progeria + + + align:start position:0% +cell development in kids with progeria +so now i told you + + align:start position:0% +so now i told you + + + align:start position:0% +so now i told you +about where are we here hold on + + align:start position:0% +about where are we here hold on + + + align:start position:0% +about where are we here hold on +sorry about 80 or 90 genes that were in + + align:start position:0% +sorry about 80 or 90 genes that were in + + + align:start position:0% +sorry about 80 or 90 genes that were in +the mouse models going along with fat + + align:start position:0% +the mouse models going along with fat + + + align:start position:0% +the mouse models going along with fat +so about 360 genes that are different + + align:start position:0% +so about 360 genes that are different + + + align:start position:0% +so about 360 genes that are different +between progeria kids and age max + + align:start position:0% +between progeria kids and age max + + + align:start position:0% +between progeria kids and age max +controls and they have some problem with + + align:start position:0% +controls and they have some problem with + + + align:start position:0% +controls and they have some problem with +that + + align:start position:0% +that + + + align:start position:0% +that +i have a third data set here which was + + align:start position:0% +i have a third data set here which was + + + align:start position:0% +i have a third data set here which was +published by gary robkins group over at + + align:start position:0% +published by gary robkins group over at + + + align:start position:0% +published by gary robkins group over at +mass general hospital this came out + + align:start position:0% +mass general hospital this came out + + + align:start position:0% +mass general hospital this came out +about last year and now this is in a + + align:start position:0% +about last year and now this is in a + + + align:start position:0% +about last year and now this is in a +totally different species this is in the + + align:start position:0% +totally different species this is in the + + + align:start position:0% +totally different species this is in the +worm to give you an idea of what we can + + align:start position:0% +worm to give you an idea of what we can + + + align:start position:0% +worm to give you an idea of what we can +do today what this group did is there + + align:start position:0% +do today what this group did is there + + + align:start position:0% +do today what this group did is there +they knocked out every single gene in + + align:start position:0% +they knocked out every single gene in + + + align:start position:0% +they knocked out every single gene in +the worm genome okay so worm has about + + align:start position:0% +the worm genome okay so worm has about + + + align:start position:0% +the worm genome okay so worm has about +16 17 000 genes + + align:start position:0% +16 17 000 genes + + + align:start position:0% +16 17 000 genes +and they basically serially knocked out + + align:start position:0% +and they basically serially knocked out + + + align:start position:0% +and they basically serially knocked out +each and every one of these genes to + + align:start position:0% +each and every one of these genes to + + + align:start position:0% +each and every one of these genes to +look at what happens to the one + + align:start position:0% +look at what happens to the one + + + align:start position:0% +look at what happens to the one +now worm it's actually pretty easy to do + + align:start position:0% +now worm it's actually pretty easy to do + + + align:start position:0% +now worm it's actually pretty easy to do +you can actually get bacteria to make a + + align:start position:0% +you can actually get bacteria to make a + + + align:start position:0% +you can actually get bacteria to make a +particular sequence called an rnai that + + align:start position:0% +particular sequence called an rnai that + + + align:start position:0% +particular sequence called an rnai that +interferes with the worms ability to + + align:start position:0% +interferes with the worms ability to + + + align:start position:0% +interferes with the worms ability to +make that gene so you don't even have to + + align:start position:0% +make that gene so you don't even have to + + + align:start position:0% +make that gene so you don't even have to +change the dna you could just + + align:start position:0% +change the dna you could just + + + align:start position:0% +change the dna you could just +effectively shut down the amount of that + + align:start position:0% +effectively shut down the amount of that + + + align:start position:0% +effectively shut down the amount of that +gene that's being made in the worm + + align:start position:0% +gene that's being made in the worm + + + align:start position:0% +gene that's being made in the worm +and basically it's very easy you don't + + align:start position:0% +and basically it's very easy you don't + + + align:start position:0% +and basically it's very easy you don't +even have to inject these worms you set + + align:start position:0% +even have to inject these worms you set + + + align:start position:0% +even have to inject these worms you set +up essentially set of 16 700 buckets of + + align:start position:0% +up essentially set of 16 700 buckets of + + + align:start position:0% +up essentially set of 16 700 buckets of +bacteria and just put the worms in it + + align:start position:0% +bacteria and just put the worms in it + + + align:start position:0% +bacteria and just put the worms in it +and they eat the bacteria and basically + + align:start position:0% +and they eat the bacteria and basically + + + align:start position:0% +and they eat the bacteria and basically +they knock out the gene + + align:start position:0% +they knock out the gene + + + align:start position:0% +they knock out the gene +themselves that's literally how it works + + align:start position:0% +themselves that's literally how it works + + + align:start position:0% +themselves that's literally how it works +all you have to do is get the worm to + + align:start position:0% +all you have to do is get the worm to + + + align:start position:0% +all you have to do is get the worm to +eat the bacteria that makes the rnai + + align:start position:0% +eat the bacteria that makes the rnai + + + align:start position:0% +eat the bacteria that makes the rnai +it's very easy it knocks out the g in + + align:start position:0% +it's very easy it knocks out the g in + + + align:start position:0% +it's very easy it knocks out the g in +that worm + + align:start position:0% +that worm + + + align:start position:0% +that worm +so what these guys did is they had + + align:start position:0% +so what these guys did is they had + + + align:start position:0% +so what these guys did is they had +back-to-back nature papers on this + + align:start position:0% +back-to-back nature papers on this + + + align:start position:0% +back-to-back nature papers on this +process the first one was on a whole + + align:start position:0% +process the first one was on a whole + + + align:start position:0% +process the first one was on a whole +bunch of different phenotypes but the + + align:start position:0% +bunch of different phenotypes but the + + + align:start position:0% +bunch of different phenotypes but the +second paper was looking at fat + + align:start position:0% +second paper was looking at fat + + + align:start position:0% +second paper was looking at fat +amazingly enough and here there's a + + align:start position:0% +amazingly enough and here there's a + + + align:start position:0% +amazingly enough and here there's a +picture of a worm and they're using the + + align:start position:0% +picture of a worm and they're using the + + + align:start position:0% +picture of a worm and they're using the +same stain for lipid that i showed you + + align:start position:0% +same stain for lipid that i showed you + + + align:start position:0% +same stain for lipid that i showed you +two or three slides ago okay what we + + align:start position:0% +two or three slides ago okay what we + + + align:start position:0% +two or three slides ago okay what we +were using in the mouse and basically + + align:start position:0% +were using in the mouse and basically + + + align:start position:0% +were using in the mouse and basically +they're saying for example if you knock + + align:start position:0% +they're saying for example if you knock + + + align:start position:0% +they're saying for example if you knock +out daf2 you get an increase in the fat + + align:start position:0% +out daf2 you get an increase in the fat + + + align:start position:0% +out daf2 you get an increase in the fat +if you're not gonna have to end that + + align:start position:0% +if you're not gonna have to end that + + + align:start position:0% +if you're not gonna have to end that +succeed you get a subsequent decrease + + align:start position:0% +succeed you get a subsequent decrease + + + align:start position:0% +succeed you get a subsequent decrease +the afternoon that three slightly more + + align:start position:0% +the afternoon that three slightly more + + + align:start position:0% +the afternoon that three slightly more +and they can quantitate the amount of + + align:start position:0% +and they can quantitate the amount of + + + align:start position:0% +and they can quantitate the amount of +fat that have that results after you've + + align:start position:0% +fat that have that results after you've + + + align:start position:0% +fat that have that results after you've +knocked out any of these genes and + + align:start position:0% +knocked out any of these genes and + + + align:start position:0% +knocked out any of these genes and +essentially they've made a list it's + + align:start position:0% +essentially they've made a list it's + + + align:start position:0% +essentially they've made a list it's +available on the internet amazingly + + align:start position:0% +available on the internet amazingly + + + align:start position:0% +available on the internet amazingly +you're not get any of these 112 genes it + + align:start position:0% +you're not get any of these 112 genes it + + + align:start position:0% +you're not get any of these 112 genes it +increases the amount of fat in the worm + + align:start position:0% +increases the amount of fat in the worm + + + align:start position:0% +increases the amount of fat in the worm +you're not getting any of these 305 + + align:start position:0% +you're not getting any of these 305 + + + align:start position:0% +you're not getting any of these 305 +genes a decrease in the amount of fat in + + align:start position:0% +genes a decrease in the amount of fat in + + + align:start position:0% +genes a decrease in the amount of fat in +the worm + + align:start position:0% +the worm + + + align:start position:0% +the worm +so now we have three big data sets + + align:start position:0% +so now we have three big data sets + + + align:start position:0% +so now we have three big data sets +one in the mouse one in the human + + align:start position:0% +one in the mouse one in the human + + + align:start position:0% +one in the mouse one in the human +one in the worm + + align:start position:0% +one in the worm + + + align:start position:0% +one in the worm +two microarrays one rnai + + align:start position:0% +two microarrays one rnai + + + align:start position:0% +two microarrays one rnai +okay spanning all these but they all + + align:start position:0% +okay spanning all these but they all + + + align:start position:0% +okay spanning all these but they all +have something to do with each other + + align:start position:0% +have something to do with each other + + + align:start position:0% +have something to do with each other +because they're all thinking about fat + + align:start position:0% +because they're all thinking about fat + + + align:start position:0% +because they're all thinking about fat +and fat storage + + align:start position:0% +and fat storage + + + align:start position:0% +and fat storage +okay that storage in the worm is very + + align:start position:0% +okay that storage in the worm is very + + + align:start position:0% +okay that storage in the worm is very +different than the human but still a + + align:start position:0% +different than the human but still a + + + align:start position:0% +different than the human but still a +number of the genes are actually + + align:start position:0% +number of the genes are actually + + + align:start position:0% +number of the genes are actually +intersecting and really what we're + + align:start position:0% +intersecting and really what we're + + + align:start position:0% +intersecting and really what we're +talking about is intersecting these + + align:start position:0% +talking about is intersecting these + + + align:start position:0% +talking about is intersecting these +three data sets + + align:start position:0% +three data sets + + + align:start position:0% +three data sets +we've got the worm we've got the mouse + + align:start position:0% +we've got the worm we've got the mouse + + + align:start position:0% +we've got the worm we've got the mouse +we've got the progeria and we're looking + + align:start position:0% +we've got the progeria and we're looking + + + align:start position:0% +we've got the progeria and we're looking +at the intersection of all these three + + align:start position:0% +at the intersection of all these three + + + align:start position:0% +at the intersection of all these three +so this is what i've been working on + + align:start position:0% +so this is what i've been working on + + + align:start position:0% +so this is what i've been working on +over the past six months actually and + + align:start position:0% +over the past six months actually and + + + align:start position:0% +over the past six months actually and +this is what we're calling integrative + + align:start position:0% +this is what we're calling integrative + + + align:start position:0% +this is what we're calling integrative +biology or integrative genomics + + align:start position:0% +biology or integrative genomics + + + align:start position:0% +biology or integrative genomics +okay because these large data sets are + + align:start position:0% +okay because these large data sets are + + + align:start position:0% +okay because these large data sets are +not only they don't just exist in a + + align:start position:0% +not only they don't just exist in a + + + align:start position:0% +not only they don't just exist in a +large majority they are actually + + align:start position:0% +large majority they are actually + + + align:start position:0% +large majority they are actually +publicly available you could go to the + + align:start position:0% +publicly available you could go to the + + + align:start position:0% +publicly available you could go to the +national center for biotechnology + + align:start position:0% +national center for biotechnology + + + align:start position:0% +national center for biotechnology +information than ncbi geo + + align:start position:0% +information than ncbi geo + + + align:start position:0% +information than ncbi geo +and pull down any number of these kinds + + align:start position:0% +and pull down any number of these kinds + + + align:start position:0% +and pull down any number of these kinds +of data sets + + align:start position:0% +of data sets + + + align:start position:0% +of data sets +okay you could do it today as for your + + align:start position:0% +okay you could do it today as for your + + + align:start position:0% +okay you could do it today as for your +final project you can go download any of + + align:start position:0% +final project you can go download any of + + + align:start position:0% +final project you can go download any of +600 experiments with the micros already + + align:start position:0% +600 experiments with the micros already + + + align:start position:0% +600 experiments with the micros already +been collected + + align:start position:0% +been collected + + + align:start position:0% +been collected +the only hard part now is to have the + + align:start position:0% +the only hard part now is to have the + + + align:start position:0% +the only hard part now is to have the +interesting question + + align:start position:0% +interesting question + + + align:start position:0% +interesting question +okay you can't just pair something with + + align:start position:0% +okay you can't just pair something with + + + align:start position:0% +okay you can't just pair something with +something else you want to have to + + align:start position:0% +something else you want to have to + + + align:start position:0% +something else you want to have to +actually think about an interesting + + align:start position:0% +actually think about an interesting + + + align:start position:0% +actually think about an interesting +question because the resources in all + + align:start position:0% +question because the resources in all + + + align:start position:0% +question because the resources in all +likelihood are already there to actually + + align:start position:0% +likelihood are already there to actually + + + align:start position:0% +likelihood are already there to actually +try to answer your question whether + + align:start position:0% +try to answer your question whether + + + align:start position:0% +try to answer your question whether +you're interested in circadian rhythms + + align:start position:0% +you're interested in circadian rhythms + + + align:start position:0% +you're interested in circadian rhythms +or fat development or anything + + align:start position:0% +or fat development or anything + + + align:start position:0% +or fat development or anything +that's the hard part now is knowing + + align:start position:0% +that's the hard part now is knowing + + + align:start position:0% +that's the hard part now is knowing +enough biology to actually ask an + + align:start position:0% +enough biology to actually ask an + + + align:start position:0% +enough biology to actually ask an +interesting question in this way + + align:start position:0% + + + + align:start position:0% + +such as if you look at the genes in + + align:start position:0% +such as if you look at the genes in + + + align:start position:0% +such as if you look at the genes in +intersection just to give you an idea + + align:start position:0% +intersection just to give you an idea + + + align:start position:0% +intersection just to give you an idea +these winch genes wind is actually a + + align:start position:0% +these winch genes wind is actually a + + + align:start position:0% +these winch genes wind is actually a +hormone that's made + + align:start position:0% +hormone that's made + + + align:start position:0% +hormone that's made +wink genes are actually well known to be + + align:start position:0% +wink genes are actually well known to be + + + align:start position:0% +wink genes are actually well known to be +involved with adipogenesis and they are + + align:start position:0% +involved with adipogenesis and they are + + + align:start position:0% +involved with adipogenesis and they are +actually living in the intersection of + + align:start position:0% +actually living in the intersection of + + + align:start position:0% +actually living in the intersection of +these lists so the worm egl2 which is + + align:start position:0% +these lists so the worm egl2 which is + + + align:start position:0% +these lists so the worm egl2 which is +called wind 7b increases uh the amount + + align:start position:0% +called wind 7b increases uh the amount + + + align:start position:0% +called wind 7b increases uh the amount +of fat if it's knocked out the mouse + + align:start position:0% +of fat if it's knocked out the mouse + + + align:start position:0% +of fat if it's knocked out the mouse +wins 6 and 10a increase with + + align:start position:0% +wins 6 and 10a increase with + + + align:start position:0% +wins 6 and 10a increase with +dysadipogenesis depending on the irs + + align:start position:0% +dysadipogenesis depending on the irs + + + align:start position:0% +dysadipogenesis depending on the irs +knockouts and when 5a and wind 7b are + + align:start position:0% +knockouts and when 5a and wind 7b are + + + align:start position:0% +knockouts and when 5a and wind 7b are +down in progeria so that's an example of + + align:start position:0% +down in progeria so that's an example of + + + align:start position:0% +down in progeria so that's an example of +a gene that lives in the intersection of + + align:start position:0% +a gene that lives in the intersection of + + + align:start position:0% +a gene that lives in the intersection of +these three data sets i'm just amazed + + align:start position:0% +these three data sets i'm just amazed + + + align:start position:0% +these three data sets i'm just amazed +that we got any of these things to + + align:start position:0% +that we got any of these things to + + + align:start position:0% +that we got any of these things to +intersect because they're so different + + align:start position:0% +intersect because they're so different + + + align:start position:0% +intersect because they're so different +three different species we're not even + + align:start position:0% +three different species we're not even + + + align:start position:0% +three different species we're not even +looking at the fat cells here right but + + align:start position:0% +looking at the fat cells here right but + + + align:start position:0% +looking at the fat cells here right but +the progeria kids we're looking at a + + align:start position:0% +the progeria kids we're looking at a + + + align:start position:0% +the progeria kids we're looking at a +fibroblast which is a proxy for the + + align:start position:0% +fibroblast which is a proxy for the + + + align:start position:0% +fibroblast which is a proxy for the +pre-adipocyte which is a proxy for the + + align:start position:0% +pre-adipocyte which is a proxy for the + + + align:start position:0% +pre-adipocyte which is a proxy for the +adipocyte okay but still you can get + + align:start position:0% +adipocyte okay but still you can get + + + align:start position:0% +adipocyte okay but still you can get +some signal this way + + align:start position:0% + + + + align:start position:0% + +this is this picture is just the same + + align:start position:0% +this is this picture is just the same + + + align:start position:0% +this is this picture is just the same +even my own daughter knows the + + align:start position:0% +even my own daughter knows the + + + align:start position:0% +even my own daughter knows the +difference between a human a mouse and a + + align:start position:0% +difference between a human a mouse and a + + + align:start position:0% +difference between a human a mouse and a +worm + + align:start position:0% +worm + + + align:start position:0% +worm +okay so there's caveats to all of this + + align:start position:0% +okay so there's caveats to all of this + + + align:start position:0% +okay so there's caveats to all of this +so we're doing a lot of this validation + + align:start position:0% +so we're doing a lot of this validation + + + align:start position:0% +so we're doing a lot of this validation +ourselves now in the bioinformatics + + align:start position:0% +ourselves now in the bioinformatics + + + align:start position:0% +ourselves now in the bioinformatics +group over at children's but this is the + + align:start position:0% +group over at children's but this is the + + + align:start position:0% +group over at children's but this is the +point here is integrated biology to me + + align:start position:0% +point here is integrated biology to me + + + align:start position:0% +point here is integrated biology to me +this is where i think a lot of fun is + + align:start position:0% +this is where i think a lot of fun is + + + align:start position:0% +this is where i think a lot of fun is +going to happen for me in the next few + + align:start position:0% +going to happen for me in the next few + + + align:start position:0% +going to happen for me in the next few +years + + align:start position:0% +years + + + align:start position:0% +years +okay we have a lot of these data sets + + align:start position:0% +okay we have a lot of these data sets + + + align:start position:0% +okay we have a lot of these data sets +and now i'm trying to come up with + + align:start position:0% +and now i'm trying to come up with + + + align:start position:0% +and now i'm trying to come up with +interesting questions so i can put these + + align:start position:0% +interesting questions so i can put these + + + align:start position:0% +interesting questions so i can put these +together to try to get a massive handle + + align:start position:0% +together to try to get a massive handle + + + align:start position:0% +together to try to get a massive handle +on these on these processes other people + + align:start position:0% +on these on these processes other people + + + align:start position:0% +on these on these processes other people +are just using one of these data might + + align:start position:0% +are just using one of these data might + + + align:start position:0% +are just using one of these data might +not be able to get a grasp on we've got + + align:start position:0% +not be able to get a grasp on we've got + + + align:start position:0% +not be able to get a grasp on we've got +gene expression we've got proteomic data + + align:start position:0% +gene expression we've got proteomic data + + + align:start position:0% +gene expression we've got proteomic data +we've talked about that we've got genome + + align:start position:0% +we've talked about that we've got genome + + + align:start position:0% +we've talked about that we've got genome +scans so we have uh joel hirschhorn's + + align:start position:0% +scans so we have uh joel hirschhorn's + + + align:start position:0% +scans so we have uh joel hirschhorn's +going to be talking about how you + + align:start position:0% +going to be talking about how you + + + align:start position:0% +going to be talking about how you +actually try to find genes that are + + align:start position:0% +actually try to find genes that are + + + align:start position:0% +actually try to find genes that are +associated with particular phenotype + + align:start position:0% +associated with particular phenotype + + + align:start position:0% +associated with particular phenotype +using snips + + align:start position:0% +using snips + + + align:start position:0% +using snips +they have the clinical measurements okay + + align:start position:0% +they have the clinical measurements okay + + + align:start position:0% +they have the clinical measurements okay +we have all of these data points that + + align:start position:0% +we have all of these data points that + + + align:start position:0% +we have all of these data points that +are collected all of these hospitals + + align:start position:0% +are collected all of these hospitals + + + align:start position:0% +are collected all of these hospitals +we have uh i'll talk about i'll talk + + align:start position:0% +we have uh i'll talk about i'll talk + + + align:start position:0% +we have uh i'll talk about i'll talk +about each of these separately + + align:start position:0% +about each of these separately + + + align:start position:0% +about each of these separately +enumetogenesis is a new technique where + + align:start position:0% +enumetogenesis is a new technique where + + + align:start position:0% +enumetogenesis is a new technique where +it's actually not so new but you could + + align:start position:0% +it's actually not so new but you could + + + align:start position:0% +it's actually not so new but you could +take mice + + align:start position:0% +take mice + + + align:start position:0% +take mice +and give them this particular chemical + + align:start position:0% +and give them this particular chemical + + + align:start position:0% +and give them this particular chemical +ethyl nitrosyl urea and causes mutations + + align:start position:0% +ethyl nitrosyl urea and causes mutations + + + align:start position:0% +ethyl nitrosyl urea and causes mutations +in their gametes so then all of their + + align:start position:0% +in their gametes so then all of their + + + align:start position:0% +in their gametes so then all of their +offspring basically are mutants + + align:start position:0% +offspring basically are mutants + + + align:start position:0% +offspring basically are mutants +and you do this for a couple generations + + align:start position:0% +and you do this for a couple generations + + + align:start position:0% +and you do this for a couple generations +and you find the interesting phenotype + + align:start position:0% +and you find the interesting phenotype + + + align:start position:0% +and you find the interesting phenotype +that you're that wow all of a sudden + + align:start position:0% +that you're that wow all of a sudden + + + align:start position:0% +that you're that wow all of a sudden +this one has diabetes you go back and + + align:start position:0% +this one has diabetes you go back and + + + align:start position:0% +this one has diabetes you go back and +see what do we mutate + + align:start position:0% +see what do we mutate + + + align:start position:0% +see what do we mutate +okay you're basically mutagenizing as + + align:start position:0% +okay you're basically mutagenizing as + + + align:start position:0% +okay you're basically mutagenizing as +much as you can you characterize the + + align:start position:0% +much as you can you characterize the + + + align:start position:0% +much as you can you characterize the +output and then go back to see what + + align:start position:0% +output and then go back to see what + + + align:start position:0% +output and then go back to see what +exactly where do we put the mutation in + + align:start position:0% +exactly where do we put the mutation in + + + align:start position:0% +exactly where do we put the mutation in +that's enu meteogenesis grade rnai we + + align:start position:0% +that's enu meteogenesis grade rnai we + + + align:start position:0% +that's enu meteogenesis grade rnai we +start to talk about with the worm where + + align:start position:0% +start to talk about with the worm where + + + align:start position:0% +start to talk about with the worm where +you basically can just knock out any + + align:start position:0% +you basically can just knock out any + + + align:start position:0% +you basically can just knock out any +particular gene very quickly people are + + align:start position:0% +particular gene very quickly people are + + + align:start position:0% +particular gene very quickly people are +starting to do this with humans and + + align:start position:0% +starting to do this with humans and + + + align:start position:0% +starting to do this with humans and +specifically with mouse models but it's + + align:start position:0% +specifically with mouse models but it's + + + align:start position:0% +specifically with mouse models but it's +already a number of pharmaceutical + + align:start position:0% +already a number of pharmaceutical + + + align:start position:0% +already a number of pharmaceutical +companies within a five mile radius if + + align:start position:0% +companies within a five mile radius if + + + align:start position:0% +companies within a five mile radius if +you're trying to come up with drugs like + + align:start position:0% +you're trying to come up with drugs like + + + align:start position:0% +you're trying to come up with drugs like +that + + align:start position:0% +that + + + align:start position:0% +that +and of course most importantly the prior + + align:start position:0% +and of course most importantly the prior + + + align:start position:0% +and of course most importantly the prior +biological knowledge this is what's + + align:start position:0% +biological knowledge this is what's + + + align:start position:0% +biological knowledge this is what's +going to drive the interesting questions + + align:start position:0% +going to drive the interesting questions + + + align:start position:0% +going to drive the interesting questions +here + + align:start position:0% + + + + align:start position:0% + +any questions about that so far + + align:start position:0% + + + + align:start position:0% + +all right + + align:start position:0% + + + + align:start position:0% + +i'm going to talk about something + + align:start position:0% +i'm going to talk about something + + + align:start position:0% +i'm going to talk about something +just to bring this home so we can + + align:start position:0% + + + + align:start position:0% + +we can talk about at least you can see + + align:start position:0% +we can talk about at least you can see + + + align:start position:0% +we can talk about at least you can see +how easy it is to actually do this + + align:start position:0% +how easy it is to actually do this + + + align:start position:0% +how easy it is to actually do this +okay let me skip a couple slides here + + align:start position:0% + + + + align:start position:0% + +okay so yeah we can actually talk about + + align:start position:0% +okay so yeah we can actually talk about + + + align:start position:0% +okay so yeah we can actually talk about +some of this + + align:start position:0% +some of this + + + align:start position:0% +some of this +so let's say you're interested in doing + + align:start position:0% +so let's say you're interested in doing + + + align:start position:0% +so let's say you're interested in doing +some of this for a final project okay + + align:start position:0% +some of this for a final project okay + + + align:start position:0% +some of this for a final project okay +that you want to actually put some of + + align:start position:0% +that you want to actually put some of + + + align:start position:0% +that you want to actually put some of +these data sets together + + align:start position:0% +these data sets together + + + align:start position:0% +these data sets together +there are quite a number of sources + + align:start position:0% +there are quite a number of sources + + + align:start position:0% +there are quite a number of sources +where you can get web + + align:start position:0% +where you can get web + + + align:start position:0% +where you can get web +get microarray data and other genome + + align:start position:0% +get microarray data and other genome + + + align:start position:0% +get microarray data and other genome +size data today + + align:start position:0% + + + + align:start position:0% + +and if you see some things in the + + align:start position:0% +and if you see some things in the + + + align:start position:0% +and if you see some things in the +description that you're actually + + align:start position:0% +description that you're actually + + + align:start position:0% +description that you're actually +biologically interested in you might be + + align:start position:0% +biologically interested in you might be + + + align:start position:0% +biologically interested in you might be +able to run with that for a final + + align:start position:0% +able to run with that for a final + + + align:start position:0% +able to run with that for a final +project i just want to point out a few + + align:start position:0% +project i just want to point out a few + + + align:start position:0% +project i just want to point out a few +of these data sources + + align:start position:0% +of these data sources + + + align:start position:0% +of these data sources +and then talk about one way how you can + + align:start position:0% +and then talk about one way how you can + + + align:start position:0% +and then talk about one way how you can +put this together using a web even just + + align:start position:0% +put this together using a web even just + + + align:start position:0% +put this together using a web even just +using a web browser + + align:start position:0% +using a web browser + + + align:start position:0% +using a web browser +so the cardiogenomics program is a + + align:start position:0% +so the cardiogenomics program is a + + + align:start position:0% +so the cardiogenomics program is a +source where i think there's over 150 + + align:start position:0% +source where i think there's over 150 + + + align:start position:0% +source where i think there's over 150 +microarrays now + + align:start position:0% +microarrays now + + + align:start position:0% +microarrays now +this is over the headquarters of this is + + align:start position:0% +this is over the headquarters of this is + + + align:start position:0% +this is over the headquarters of this is +over at the bethesda deaconess across + + align:start position:0% +over at the bethesda deaconess across + + + align:start position:0% +over at the bethesda deaconess across +the street they have mass models of + + align:start position:0% +the street they have mass models of + + + align:start position:0% +the street they have mass models of +cardiac development so basically they + + align:start position:0% +cardiac development so basically they + + + align:start position:0% +cardiac development so basically they +have embryos and they have sections of + + align:start position:0% +have embryos and they have sections of + + + align:start position:0% +have embryos and they have sections of +their heart and basically all the genes + + align:start position:0% +their heart and basically all the genes + + + align:start position:0% +their heart and basically all the genes +are turned on and off at different parts + + align:start position:0% +are turned on and off at different parts + + + align:start position:0% +are turned on and off at different parts +during development + + align:start position:0% +during development + + + align:start position:0% +during development +there's all sorts of different + + align:start position:0% +there's all sorts of different + + + align:start position:0% +there's all sorts of different +components of cardiac growth so for + + align:start position:0% +components of cardiac growth so for + + + align:start position:0% +components of cardiac growth so for +example people know that if you one + + align:start position:0% +example people know that if you one + + + align:start position:0% +example people know that if you one +pathway or another pathway is involved + + align:start position:0% +pathway or another pathway is involved + + + align:start position:0% +pathway or another pathway is involved +in heart failure they have mouse models + + align:start position:0% +in heart failure they have mouse models + + + align:start position:0% +in heart failure they have mouse models +where those components are already + + align:start position:0% +where those components are already + + + align:start position:0% +where those components are already +knocked out + + align:start position:0% +knocked out + + + align:start position:0% +knocked out +they have a bunch of measures made in + + align:start position:0% +they have a bunch of measures made in + + + align:start position:0% +they have a bunch of measures made in +time series so they take a normal mice + + align:start position:0% +time series so they take a normal mice + + + align:start position:0% +time series so they take a normal mice +and they put them in this tank to swim + + align:start position:0% +and they put them in this tank to swim + + + align:start position:0% +and they put them in this tank to swim +and make them practice swimming certain + + align:start position:0% +and make them practice swimming certain + + + align:start position:0% +and make them practice swimming certain +number of hours for weeks then look at + + align:start position:0% +number of hours for weeks then look at + + + align:start position:0% +number of hours for weeks then look at +their hearts and this is what swimming + + align:start position:0% +their hearts and this is what swimming + + + align:start position:0% +their hearts and this is what swimming +does your heart for example they have + + align:start position:0% +does your heart for example they have + + + align:start position:0% +does your heart for example they have +those lists of genes available today + + align:start position:0% + + + + align:start position:0% + +these slides are going to be online so + + align:start position:0% +these slides are going to be online so + + + align:start position:0% +these slides are going to be online so +you don't have to copy down every single + + align:start position:0% +you don't have to copy down every single + + + align:start position:0% +you don't have to copy down every single +uh url but if you just even write down + + align:start position:0% +uh url but if you just even write down + + + align:start position:0% +uh url but if you just even write down +the heading then you know which one to + + align:start position:0% +the heading then you know which one to + + + align:start position:0% +the heading then you know which one to +look for + + align:start position:0% +look for + + + align:start position:0% +look for +the whitehead institute obviously mother + + align:start position:0% +the whitehead institute obviously mother + + + align:start position:0% +the whitehead institute obviously mother +lode of diesel race okay at least 12 + + align:start position:0% +lode of diesel race okay at least 12 + + + align:start position:0% +lode of diesel race okay at least 12 +maybe probably 14 publications now + + align:start position:0% +maybe probably 14 publications now + + + align:start position:0% +maybe probably 14 publications now +many different types of cancer that's + + align:start position:0% +many different types of cancer that's + + + align:start position:0% +many different types of cancer that's +their primary focus there a lot of + + align:start position:0% +their primary focus there a lot of + + + align:start position:0% +their primary focus there a lot of +clinical measurements with some i mean a + + align:start position:0% +clinical measurements with some i mean a + + + align:start position:0% +clinical measurements with some i mean a +lot of these are clinical samples but + + align:start position:0% +lot of these are clinical samples but + + + align:start position:0% +lot of these are clinical samples but +they might have one or two columns of + + align:start position:0% +they might have one or two columns of + + + align:start position:0% +they might have one or two columns of +clinical measurements like once it's a + + align:start position:0% +clinical measurements like once it's a + + + align:start position:0% +clinical measurements like once it's a +smoker was this a non-smoker + + align:start position:0% +smoker was this a non-smoker + + + align:start position:0% +smoker was this a non-smoker +that kind of thing how long does this + + align:start position:0% +that kind of thing how long does this + + + align:start position:0% +that kind of thing how long does this +patient relapse and not relapse but you + + align:start position:0% +patient relapse and not relapse but you + + + align:start position:0% +patient relapse and not relapse but you +got leukemias you got solid tumors here + + align:start position:0% +got leukemias you got solid tumors here + + + align:start position:0% +got leukemias you got solid tumors here +so + + align:start position:0% +so + + + align:start position:0% +so +brain cancers things like that are in + + align:start position:0% +brain cancers things like that are in + + + align:start position:0% +brain cancers things like that are in +this data set + + align:start position:0% + + + + align:start position:0% + +dc children's or children's national + + align:start position:0% +dc children's or children's national + + + align:start position:0% +dc children's or children's national +medical center + + align:start position:0% +medical center + + + align:start position:0% +medical center +500 arrays for many interesting human + + align:start position:0% +500 arrays for many interesting human + + + align:start position:0% +500 arrays for many interesting human +diseases muscular dystrophy + + align:start position:0% +diseases muscular dystrophy + + + align:start position:0% +diseases muscular dystrophy +dermatomyositis so it's rare types of + + align:start position:0% +dermatomyositis so it's rare types of + + + align:start position:0% +dermatomyositis so it's rare types of +rheumatological things heart failure as + + align:start position:0% +rheumatological things heart failure as + + + align:start position:0% +rheumatological things heart failure as +well as mouse rat and dog models of + + align:start position:0% +well as mouse rat and dog models of + + + align:start position:0% +well as mouse rat and dog models of +spinal cord injury if you want to see + + align:start position:0% +spinal cord injury if you want to see + + + align:start position:0% +spinal cord injury if you want to see +what are the similarities and + + align:start position:0% +what are the similarities and + + + align:start position:0% +what are the similarities and +differences there pulmonary disease + + align:start position:0% +differences there pulmonary disease + + + align:start position:0% +differences there pulmonary disease +including asthma and heart failure i + + align:start position:0% +including asthma and heart failure i + + + align:start position:0% +including asthma and heart failure i +mentioned heart failure twice there + + align:start position:0% +mentioned heart failure twice there + + + align:start position:0% +mentioned heart failure twice there +so that's dc children's and johns + + align:start position:0% +so that's dc children's and johns + + + align:start position:0% +so that's dc children's and johns +hopkins the human gene expression index + + align:start position:0% +hopkins the human gene expression index + + + align:start position:0% +hopkins the human gene expression index +i think it's the best is brigham and + + align:start position:0% +i think it's the best is brigham and + + + align:start position:0% +i think it's the best is brigham and +women's 121 microarrays just from normal + + align:start position:0% +women's 121 microarrays just from normal + + + align:start position:0% +women's 121 microarrays just from normal +tissues 19 normal human tissues it's + + align:start position:0% +tissues 19 normal human tissues it's + + + align:start position:0% +tissues 19 normal human tissues it's +also an interesting list to think about + + align:start position:0% + + + + align:start position:0% + +stanford's microwave is probably the + + align:start position:0% +stanford's microwave is probably the + + + align:start position:0% +stanford's microwave is probably the +largest besides the + + align:start position:0% +largest besides the + + + align:start position:0% +largest besides the +geo which we'll talk about a second + + align:start position:0% +geo which we'll talk about a second + + + align:start position:0% +geo which we'll talk about a second +stanford has probably close to 4 000 + + align:start position:0% +stanford has probably close to 4 000 + + + align:start position:0% +stanford has probably close to 4 000 +arrays now measure across 11 species + + align:start position:0% +arrays now measure across 11 species + + + align:start position:0% +arrays now measure across 11 species +covering more than 80 publications + + align:start position:0% +covering more than 80 publications + + + align:start position:0% +covering more than 80 publications +okay many different fields most of which + + align:start position:0% +okay many different fields most of which + + + align:start position:0% +okay many different fields most of which +are yeast by the whole bunch of human + + align:start position:0% +are yeast by the whole bunch of human + + + align:start position:0% +are yeast by the whole bunch of human +ones as well + + align:start position:0% +ones as well + + + align:start position:0% +ones as well +the national ncbi gl + + align:start position:0% +the national ncbi gl + + + align:start position:0% +the national ncbi gl +it's basically right next to pubmed now + + align:start position:0% +it's basically right next to pubmed now + + + align:start position:0% +it's basically right next to pubmed now +it's the same website + + align:start position:0% +it's the same website + + + align:start position:0% +it's the same website +over 8 000 arrays from over 100 + + align:start position:0% +over 8 000 arrays from over 100 + + + align:start position:0% +over 8 000 arrays from over 100 +different types of microarrays okay + + align:start position:0% +different types of microarrays okay + + + align:start position:0% +different types of microarrays okay +never mind how many experiments their + + align:start position:0% +never mind how many experiments their + + + align:start position:0% +never mind how many experiments their +database can handle over 100 different + + align:start position:0% +database can handle over 100 different + + + align:start position:0% +database can handle over 100 different +companies 100 different + + align:start position:0% +companies 100 different + + + align:start position:0% +companies 100 different +actual microwave products they can + + align:start position:0% +actual microwave products they can + + + align:start position:0% +actual microwave products they can +integrate across all of these + + align:start position:0% +integrate across all of these + + + align:start position:0% +integrate across all of these +t-rex is from + + align:start position:0% +t-rex is from + + + align:start position:0% +t-rex is from +tiger which is the institute for genome + + align:start position:0% +tiger which is the institute for genome + + + align:start position:0% +tiger which is the institute for genome +research over in gaithersburg and + + align:start position:0% +research over in gaithersburg and + + + align:start position:0% +research over in gaithersburg and +maryland outside of nih + + align:start position:0% +maryland outside of nih + + + align:start position:0% +maryland outside of nih +500 600 arrays for mouse and mouse and + + align:start position:0% +500 600 arrays for mouse and mouse and + + + align:start position:0% +500 600 arrays for mouse and mouse and +wrap models of sleep infection + + align:start position:0% +wrap models of sleep infection + + + align:start position:0% +wrap models of sleep infection +hypertension pulmonary disease + + align:start position:0% +hypertension pulmonary disease + + + align:start position:0% +hypertension pulmonary disease +it's all like for example if you're + + align:start position:0% +it's all like for example if you're + + + align:start position:0% +it's all like for example if you're +interested in asthma and you want to see + + align:start position:0% +interested in asthma and you want to see + + + align:start position:0% +interested in asthma and you want to see +differences between human asthma and the + + align:start position:0% +differences between human asthma and the + + + align:start position:0% +differences between human asthma and the +mouse model the data is there today + + align:start position:0% +mouse model the data is there today + + + align:start position:0% +mouse model the data is there today +i will guarantee you no one else has + + align:start position:0% +i will guarantee you no one else has + + + align:start position:0% +i will guarantee you no one else has +done that intersection okay if you find + + align:start position:0% +done that intersection okay if you find + + + align:start position:0% +done that intersection okay if you find +some interesting genes + + align:start position:0% +some interesting genes + + + align:start position:0% +some interesting genes +that you think might code for proteins + + align:start position:0% +that you think might code for proteins + + + align:start position:0% +that you think might code for proteins +that might be in the blood and you can + + align:start position:0% +that might be in the blood and you can + + + align:start position:0% +that might be in the blood and you can +use that as a measurement you can get + + align:start position:0% +use that as a measurement you can get + + + align:start position:0% +use that as a measurement you can get +some interesting part one of any + + align:start position:0% +some interesting part one of any + + + align:start position:0% +some interesting part one of any +collaborator in the longwood area to + + align:start position:0% +collaborator in the longwood area to + + + align:start position:0% +collaborator in the longwood area to +actually measure this in the blood + + align:start position:0% +actually measure this in the blood + + + align:start position:0% +actually measure this in the blood +that's it you have a finding right there + + align:start position:0% +that's it you have a finding right there + + + align:start position:0% +that's it you have a finding right there +okay because the data is there hardly + + align:start position:0% +okay because the data is there hardly + + + align:start position:0% +okay because the data is there hardly +anyone knows how to intersect these + + align:start position:0% +anyone knows how to intersect these + + + align:start position:0% +anyone knows how to intersect these +things at all + + align:start position:0% +things at all + + + align:start position:0% +things at all +and so what i'm going to talk about here + + align:start position:0% +and so what i'm going to talk about here + + + align:start position:0% +and so what i'm going to talk about here +for the last few minutes is this concept + + align:start position:0% +for the last few minutes is this concept + + + align:start position:0% +for the last few minutes is this concept +of discovery portal okay so what do i + + align:start position:0% +of discovery portal okay so what do i + + + align:start position:0% +of discovery portal okay so what do i +mean by that let me skip this part + + align:start position:0% + + + + align:start position:0% + +we start with in vivo right experiments + + align:start position:0% +we start with in vivo right experiments + + + align:start position:0% +we start with in vivo right experiments +done in humans and mice then we had in + + align:start position:0% +done in humans and mice then we had in + + + align:start position:0% +done in humans and mice then we had in +vitro and cell culture now we have in + + align:start position:0% +vitro and cell culture now we have in + + + align:start position:0% +vitro and cell culture now we have in +http okay so here's an idea okay here's + + align:start position:0% +http okay so here's an idea okay here's + + + align:start position:0% +http okay so here's an idea okay here's +how you can go from uh actual thought to + + align:start position:0% +how you can go from uh actual thought to + + + align:start position:0% +how you can go from uh actual thought to +a pretty well established hypothesis + + align:start position:0% +a pretty well established hypothesis + + + align:start position:0% +a pretty well established hypothesis +without even leaving your web browser + + align:start position:0% +without even leaving your web browser + + + align:start position:0% +without even leaving your web browser +because all of these tools are available + + align:start position:0% +because all of these tools are available + + + align:start position:0% +because all of these tools are available +today + + align:start position:0% +today + + + align:start position:0% +today +over the next maybe 15 slides i'm going + + align:start position:0% +over the next maybe 15 slides i'm going + + + align:start position:0% +over the next maybe 15 slides i'm going +to flip through them pretty quickly i'm + + align:start position:0% +to flip through them pretty quickly i'm + + + align:start position:0% +to flip through them pretty quickly i'm +going to cover a number of different + + align:start position:0% +going to cover a number of different + + + align:start position:0% +going to cover a number of different +databases where you could get all sorts + + align:start position:0% +databases where you could get all sorts + + + align:start position:0% +databases where you could get all sorts +of inspirational ideas from so let's + + align:start position:0% +of inspirational ideas from so let's + + + align:start position:0% +of inspirational ideas from so let's +start with an interest move to a rat + + align:start position:0% +start with an interest move to a rat + + + align:start position:0% +start with an interest move to a rat +model + + align:start position:0% +model + + + align:start position:0% +model +we're going to cover qtls while we're + + align:start position:0% +we're going to cover qtls while we're + + + align:start position:0% +we're going to cover qtls while we're +there and physiological findings go to a + + align:start position:0% +there and physiological findings go to a + + + align:start position:0% +there and physiological findings go to a +rat genome map go to multiple species + + align:start position:0% +rat genome map go to multiple species + + + align:start position:0% +rat genome map go to multiple species +expression data and then end with the + + align:start position:0% +expression data and then end with the + + + align:start position:0% +expression data and then end with the +hypothesis here okay this is live you + + align:start position:0% +hypothesis here okay this is live you + + + align:start position:0% +hypothesis here okay this is live you +could do this yourself today + + align:start position:0% +could do this yourself today + + + align:start position:0% +could do this yourself today +we're going to start a website called + + align:start position:0% +we're going to start a website called + + + align:start position:0% +we're going to start a website called +fizzgen okay some of us in the room know + + align:start position:0% +fizzgen okay some of us in the room know + + + align:start position:0% +fizzgen okay some of us in the room know +about this this is uh at the uh this is + + align:start position:0% +about this this is uh at the uh this is + + + align:start position:0% +about this this is uh at the uh this is +a medical medical college of wisconsin + + align:start position:0% +a medical medical college of wisconsin + + + align:start position:0% +a medical medical college of wisconsin +what these guys do is they have a huge + + align:start position:0% +what these guys do is they have a huge + + + align:start position:0% +what these guys do is they have a huge +pipeline of things they do to mice and + + align:start position:0% +pipeline of things they do to mice and + + + align:start position:0% +pipeline of things they do to mice and +rats to measure things uh measure all + + align:start position:0% +rats to measure things uh measure all + + + align:start position:0% +rats to measure things uh measure all +sorts of different quantities how much + + align:start position:0% +sorts of different quantities how much + + + align:start position:0% +sorts of different quantities how much +does this rat pee versus that rat how + + align:start position:0% +does this rat pee versus that rat how + + + align:start position:0% +does this rat pee versus that rat how +much does this mouse breathe compared to + + align:start position:0% +much does this mouse breathe compared to + + + align:start position:0% +much does this mouse breathe compared to +this mouse etcetera etcetera and they + + align:start position:0% +this mouse etcetera etcetera and they + + + align:start position:0% +this mouse etcetera etcetera and they +have tables of all this data publicly + + align:start position:0% +have tables of all this data publicly + + + align:start position:0% +have tables of all this data publicly +available + + align:start position:0% +available + + + align:start position:0% +available +so if you go to fizzgen if you click on + + align:start position:0% +so if you go to fizzgen if you click on + + + align:start position:0% +so if you go to fizzgen if you click on +data + + align:start position:0% +data + + + align:start position:0% +data +if you click on animal model so genotype + + align:start position:0% +if you click on animal model so genotype + + + align:start position:0% +if you click on animal model so genotype +information for all strains + + align:start position:0% +information for all strains + + + align:start position:0% +information for all strains +if i scroll down a little + + align:start position:0% +if i scroll down a little + + + align:start position:0% +if i scroll down a little +i see a whole bunch of the rats + + align:start position:0% +i see a whole bunch of the rats + + + align:start position:0% +i see a whole bunch of the rats +okay + + align:start position:0% +okay + + + align:start position:0% +okay +now i might remember because i went to + + align:start position:0% +now i might remember because i went to + + + align:start position:0% +now i might remember because i went to +the diabetes association conference last + + align:start position:0% +the diabetes association conference last + + + align:start position:0% +the diabetes association conference last +year i remember hearing that the brown + + align:start position:0% +year i remember hearing that the brown + + + align:start position:0% +year i remember hearing that the brown +norway has some problem with diabetes + + align:start position:0% +norway has some problem with diabetes + + + align:start position:0% +norway has some problem with diabetes +okay i might not have even gone to the + + align:start position:0% +okay i might not have even gone to the + + + align:start position:0% +okay i might not have even gone to the +seminars on the brown or but everyone + + align:start position:0% +seminars on the brown or but everyone + + + align:start position:0% +seminars on the brown or but everyone +kept talking about brown noir brown + + align:start position:0% +kept talking about brown noir brown + + + align:start position:0% +kept talking about brown noir brown +norway i remember brown orange has a + + align:start position:0% +norway i remember brown orange has a + + + align:start position:0% +norway i remember brown orange has a +problem with the seed let's go click on + + align:start position:0% +problem with the seed let's go click on + + + align:start position:0% +problem with the seed let's go click on +the brown norway strain report + + align:start position:0% +the brown norway strain report + + + align:start position:0% +the brown norway strain report +scroll down this is the bn or brown + + align:start position:0% +scroll down this is the bn or brown + + + align:start position:0% +scroll down this is the bn or brown +norway and i can see yes it does it has + + align:start position:0% +norway and i can see yes it does it has + + + align:start position:0% +norway and i can see yes it does it has +diabetes on here diabetes qtl so what is + + align:start position:0% +diabetes on here diabetes qtl so what is + + + align:start position:0% +diabetes on here diabetes qtl so what is +a qtl + + align:start position:0% +a qtl + + + align:start position:0% +a qtl +so + + align:start position:0% +so + + + align:start position:0% +so +got the rat and it's got its own genome + + align:start position:0% +got the rat and it's got its own genome + + + align:start position:0% +got the rat and it's got its own genome +like any other creature + + align:start position:0% +like any other creature + + + align:start position:0% +like any other creature +and what the qtl is is a quantitative + + align:start position:0% +and what the qtl is is a quantitative + + + align:start position:0% +and what the qtl is is a quantitative +trait loci so a particular portion + + align:start position:0% +trait loci so a particular portion + + + align:start position:0% +trait loci so a particular portion +of a particular chromosome + + align:start position:0% +of a particular chromosome + + + align:start position:0% +of a particular chromosome +appears to be statistically + + align:start position:0% +appears to be statistically + + + align:start position:0% +appears to be statistically +significantly associated with a + + align:start position:0% +significantly associated with a + + + align:start position:0% +significantly associated with a +particular phenotypic measurement + + align:start position:0% +particular phenotypic measurement + + + align:start position:0% +particular phenotypic measurement +that's a quantitative trait loci so in + + align:start position:0% +that's a quantitative trait loci so in + + + align:start position:0% +that's a quantitative trait loci so in +other words this particular region which + + align:start position:0% +other words this particular region which + + + align:start position:0% +other words this particular region which +we're going to look at in a second on + + align:start position:0% +we're going to look at in a second on + + + align:start position:0% +we're going to look at in a second on +chromosome 2 is statistically associated + + align:start position:0% +chromosome 2 is statistically associated + + + align:start position:0% +chromosome 2 is statistically associated +with the insulin level + + align:start position:0% +with the insulin level + + + align:start position:0% +with the insulin level +the fasting insulin level of a rat + + align:start position:0% +the fasting insulin level of a rat + + + align:start position:0% +the fasting insulin level of a rat +okay so notice if you have one version + + align:start position:0% +okay so notice if you have one version + + + align:start position:0% +okay so notice if you have one version +of this + + align:start position:0% +of this + + + align:start position:0% +of this +you might have a low fasting insulin if + + align:start position:0% +you might have a low fasting insulin if + + + align:start position:0% +you might have a low fasting insulin if +you have another version you have a high + + align:start position:0% +you have another version you have a high + + + align:start position:0% +you have another version you have a high +fashion level but something in this + + align:start position:0% +fashion level but something in this + + + align:start position:0% +fashion level but something in this +region of a chromosome + + align:start position:0% +region of a chromosome + + + align:start position:0% +region of a chromosome +is associated okay we're not at the gene + + align:start position:0% +is associated okay we're not at the gene + + + align:start position:0% +is associated okay we're not at the gene +level yet but we're just in a region of + + align:start position:0% +level yet but we're just in a region of + + + align:start position:0% +level yet but we're just in a region of +a chromosome there's a starting point an + + align:start position:0% +a chromosome there's a starting point an + + + align:start position:0% +a chromosome there's a starting point an +ending point of this chromosome and some + + align:start position:0% +ending point of this chromosome and some + + + align:start position:0% +ending point of this chromosome and some +piece in the middle is associated + + align:start position:0% +piece in the middle is associated + + + align:start position:0% +piece in the middle is associated +there's all sorts of other measurements + + align:start position:0% +there's all sorts of other measurements + + + align:start position:0% +there's all sorts of other measurements +here you got x-ray hypersensitivity what + + align:start position:0% +here you got x-ray hypersensitivity what + + + align:start position:0% +here you got x-ray hypersensitivity what +does that mean well something on this + + align:start position:0% +does that mean well something on this + + + align:start position:0% +does that mean well something on this +region + + align:start position:0% +region + + + align:start position:0% +region +of chromosome one + + align:start position:0% +of chromosome one + + + align:start position:0% +of chromosome one +means you get more sensitive to x-rays + + align:start position:0% +means you get more sensitive to x-rays + + + align:start position:0% +means you get more sensitive to x-rays +okay you think about how esoteric these + + align:start position:0% +okay you think about how esoteric these + + + align:start position:0% +okay you think about how esoteric these +measurements are okay if you're + + align:start position:0% +measurements are okay if you're + + + align:start position:0% +measurements are okay if you're +interested in radiation effects there's + + align:start position:0% +interested in radiation effects there's + + + align:start position:0% +interested in radiation effects there's +your measure right there arthritis + + align:start position:0% +your measure right there arthritis + + + align:start position:0% +your measure right there arthritis +severity blood pressure body weight + + align:start position:0% +severity blood pressure body weight + + + align:start position:0% +severity blood pressure body weight +blood pressure blood pressure + + align:start position:0% +blood pressure blood pressure + + + align:start position:0% +blood pressure blood pressure +they're all sitting there waiting to be + + align:start position:0% +they're all sitting there waiting to be + + + align:start position:0% +they're all sitting there waiting to be +tapped into okay no one has enough time + + align:start position:0% +tapped into okay no one has enough time + + + align:start position:0% +tapped into okay no one has enough time +to look at every single one of these but + + align:start position:0% +to look at every single one of these but + + + align:start position:0% +to look at every single one of these but +we're mandated by nih to just put them + + align:start position:0% +we're mandated by nih to just put them + + + align:start position:0% +we're mandated by nih to just put them +out on the internet for people like you + + align:start position:0% +out on the internet for people like you + + + align:start position:0% +out on the internet for people like you +to study okay if you're interested in + + align:start position:0% +to study okay if you're interested in + + + align:start position:0% +to study okay if you're interested in +blood pressure there's three qtls right + + align:start position:0% +blood pressure there's three qtls right + + + align:start position:0% +blood pressure there's three qtls right +there that people by chance but people + + align:start position:0% +there that people by chance but people + + + align:start position:0% +there that people by chance but people +probably never even looked at + + align:start position:0% +probably never even looked at + + + align:start position:0% +probably never even looked at +let's click on this particular qtl to + + align:start position:0% +let's click on this particular qtl to + + + align:start position:0% +let's click on this particular qtl to +see what it looks like + + align:start position:0% +see what it looks like + + + align:start position:0% +see what it looks like +here's the name of the qtl nidd gk2 + + align:start position:0% +here's the name of the qtl nidd gk2 + + + align:start position:0% +here's the name of the qtl nidd gk2 +it's in the brown norway + + align:start position:0% +it's in the brown norway + + + align:start position:0% +it's in the brown norway +and here's the marker for this + + align:start position:0% +and here's the marker for this + + + align:start position:0% +and here's the marker for this +particular peak so a marker + + align:start position:0% +particular peak so a marker + + + align:start position:0% +particular peak so a marker +means this is a unique sequence in the + + align:start position:0% +means this is a unique sequence in the + + + align:start position:0% +means this is a unique sequence in the +chromosome that it's going to tell me + + align:start position:0% +chromosome that it's going to tell me + + + align:start position:0% +chromosome that it's going to tell me +whether i have the one version of this + + align:start position:0% +whether i have the one version of this + + + align:start position:0% +whether i have the one version of this +or the other + + align:start position:0% +or the other + + + align:start position:0% +or the other +let me click on that marker + + align:start position:0% +let me click on that marker + + + align:start position:0% +let me click on that marker +d2 lux 23 and here is the pcr test i + + align:start position:0% +d2 lux 23 and here is the pcr test i + + + align:start position:0% +d2 lux 23 and here is the pcr test i +would need to do + + align:start position:0% +would need to do + + + align:start position:0% +would need to do +in the rat to tell me do i have the one + + align:start position:0% +in the rat to tell me do i have the one + + + align:start position:0% +in the rat to tell me do i have the one +letter or the other letter okay or in + + align:start position:0% +letter or the other letter okay or in + + + align:start position:0% +letter or the other letter okay or in +other words do i have the one do i have + + align:start position:0% +other words do i have the one do i have + + + align:start position:0% +other words do i have the one do i have +the high insulin version or the low + + align:start position:0% +the high insulin version or the low + + + align:start position:0% +the high insulin version or the low +insulin version of this particular peak + + align:start position:0% +insulin version of this particular peak + + + align:start position:0% +insulin version of this particular peak +so it even gives you the test you could + + align:start position:0% +so it even gives you the test you could + + + align:start position:0% +so it even gives you the test you could +just go order those oligonucleotides + + align:start position:0% +just go order those oligonucleotides + + + align:start position:0% +just go order those oligonucleotides +find a rat that's walking down longwood + + align:start position:0% +find a rat that's walking down longwood + + + align:start position:0% +find a rat that's walking down longwood +avenue at night and just test to see if + + align:start position:0% +avenue at night and just test to see if + + + align:start position:0% +avenue at night and just test to see if +there's a high insulin on low insulin + + align:start position:0% +there's a high insulin on low insulin + + + align:start position:0% +there's a high insulin on low insulin +you can do it today + + align:start position:0% +you can do it today + + + align:start position:0% +you can do it today +now out of dumb luck it just so happens + + align:start position:0% +now out of dumb luck it just so happens + + + align:start position:0% +now out of dumb luck it just so happens +that they've already done the work and + + align:start position:0% +that they've already done the work and + + + align:start position:0% +that they've already done the work and +they've told us in this region of the + + align:start position:0% +they've told us in this region of the + + + align:start position:0% +they've told us in this region of the +chromosome + + align:start position:0% +chromosome + + + align:start position:0% +chromosome +we know there's a gene there + + align:start position:0% +we know there's a gene there + + + align:start position:0% +we know there's a gene there +okay it doesn't have to be but there is + + align:start position:0% +okay it doesn't have to be but there is + + + align:start position:0% +okay it doesn't have to be but there is +a gene there s 100 a4 + + align:start position:0% +a gene there s 100 a4 + + + align:start position:0% +a gene there s 100 a4 +okay that's a that's a gene that exists + + align:start position:0% +okay that's a that's a gene that exists + + + align:start position:0% +okay that's a that's a gene that exists +in this peak of significance + + align:start position:0% +in this peak of significance + + + align:start position:0% +in this peak of significance +now what we're going to do is go take + + align:start position:0% +now what we're going to do is go take + + + align:start position:0% +now what we're going to do is go take +that piece of information that name of + + align:start position:0% +that piece of information that name of + + + align:start position:0% +that piece of information that name of +that gene let's look more at that qtl + + align:start position:0% +that gene let's look more at that qtl + + + align:start position:0% +that gene let's look more at that qtl +region that region on the chromosome + + align:start position:0% +region that region on the chromosome + + + align:start position:0% +region that region on the chromosome +we're going to go to national center + + align:start position:0% +we're going to go to national center + + + align:start position:0% +we're going to go to national center +biotechnology information click on + + align:start position:0% +biotechnology information click on + + + align:start position:0% +biotechnology information click on +genomic biology + + align:start position:0% +genomic biology + + + align:start position:0% +genomic biology +i'm going to click on the rat + + align:start position:0% +i'm going to click on the rat + + + align:start position:0% +i'm going to click on the rat +and i'm going to just type in s100 a4 + + align:start position:0% +and i'm going to just type in s100 a4 + + + align:start position:0% +and i'm going to just type in s100 a4 +the name of that gene that i told us was + + align:start position:0% +the name of that gene that i told us was + + + align:start position:0% +the name of that gene that i told us was +in that region + + align:start position:0% +in that region + + + align:start position:0% +in that region +where is it in the right chromosome here + + align:start position:0% +where is it in the right chromosome here + + + align:start position:0% +where is it in the right chromosome here +it is on chromosome 2. + + align:start position:0% +it is on chromosome 2. + + + align:start position:0% +it is on chromosome 2. +it's telling us s100a4 if i click on + + align:start position:0% +it's telling us s100a4 if i click on + + + align:start position:0% +it's telling us s100a4 if i click on +that + + align:start position:0% +that + + + align:start position:0% +that +if i zoom out a little + + align:start position:0% +if i zoom out a little + + + align:start position:0% +if i zoom out a little +here's s1 here a4 and here are all the + + align:start position:0% +here's s1 here a4 and here are all the + + + align:start position:0% +here's s1 here a4 and here are all the +neighboring genes + + align:start position:0% +neighboring genes + + + align:start position:0% +neighboring genes +okay + + align:start position:0% +okay + + + align:start position:0% +okay +that's interesting there's a bunch of + + align:start position:0% +that's interesting there's a bunch of + + + align:start position:0% +that's interesting there's a bunch of +other interesting genes first s1 or a4 + + align:start position:0% +other interesting genes first s1 or a4 + + + align:start position:0% +other interesting genes first s1 or a4 +there's an a3 a6 a8 a9 this gene is one + + align:start position:0% +there's an a3 a6 a8 a9 this gene is one + + + align:start position:0% +there's an a3 a6 a8 a9 this gene is one +in many of a gene family okay so how new + + align:start position:0% +in many of a gene family okay so how new + + + align:start position:0% +in many of a gene family okay so how new +genes are often form it's through + + align:start position:0% +genes are often form it's through + + + align:start position:0% +genes are often form it's through +duplication events like this but to me + + align:start position:0% +duplication events like this but to me + + + align:start position:0% +duplication events like this but to me +more interestingly i see things like + + align:start position:0% +more interestingly i see things like + + + align:start position:0% +more interestingly i see things like +naturetic peptide receptor naturetic + + align:start position:0% +naturetic peptide receptor naturetic + + + align:start position:0% +naturetic peptide receptor naturetic +peptide is made in a number of different + + align:start position:0% +peptide is made in a number of different + + + align:start position:0% +peptide is made in a number of different +sources clean the heart has to do with + + align:start position:0% +sources clean the heart has to do with + + + align:start position:0% +sources clean the heart has to do with +blood pressure and blood volume + + align:start position:0% +blood pressure and blood volume + + + align:start position:0% +blood pressure and blood volume +regulation that's an interesting hormone + + align:start position:0% +regulation that's an interesting hormone + + + align:start position:0% +regulation that's an interesting hormone +i see some others interleukin-6 there + + align:start position:0% +i see some others interleukin-6 there + + + align:start position:0% +i see some others interleukin-6 there +might be some interesting things there + + align:start position:0% +might be some interesting things there + + + align:start position:0% +might be some interesting things there +but let's just keep running with this + + align:start position:0% +but let's just keep running with this + + + align:start position:0% +but let's just keep running with this +s100 a4 here + + align:start position:0% +s100 a4 here + + + align:start position:0% +s100 a4 here +now what i'm going to do is i'm going to + + align:start position:0% +now what i'm going to do is i'm going to + + + align:start position:0% +now what i'm going to do is i'm going to +look at where is this gene expressed + + align:start position:0% +look at where is this gene expressed + + + align:start position:0% +look at where is this gene expressed +okay i got it in a statistical peak + + align:start position:0% +okay i got it in a statistical peak + + + align:start position:0% +okay i got it in a statistical peak +i've seen what its neighbors are in the + + align:start position:0% +i've seen what its neighbors are in the + + + align:start position:0% +i've seen what its neighbors are in the +genome now i want to know why is it that + + align:start position:0% +genome now i want to know why is it that + + + align:start position:0% +genome now i want to know why is it that +this particular gene is associated with + + align:start position:0% +this particular gene is associated with + + + align:start position:0% +this particular gene is associated with +diabetes or insulin level + + align:start position:0% +diabetes or insulin level + + + align:start position:0% +diabetes or insulin level +well let's see where is that gene + + align:start position:0% +well let's see where is that gene + + + align:start position:0% +well let's see where is that gene +expressed in a whole bunch of different + + align:start position:0% +expressed in a whole bunch of different + + + align:start position:0% +expressed in a whole bunch of different +samples this is one particular search + + align:start position:0% +samples this is one particular search + + + align:start position:0% +samples this is one particular search +engine where you can just type in the + + align:start position:0% +engine where you can just type in the + + + align:start position:0% +engine where you can just type in the +name of the gene and see where is this + + align:start position:0% +name of the gene and see where is this + + + align:start position:0% +name of the gene and see where is this +gene expressed and about 1200 different + + align:start position:0% +gene expressed and about 1200 different + + + align:start position:0% +gene expressed and about 1200 different +samples + + align:start position:0% +samples + + + align:start position:0% +samples +this is specific cardiovascular + + align:start position:0% +this is specific cardiovascular + + + align:start position:0% +this is specific cardiovascular +i type in s184 it says which do you mean + + align:start position:0% +i type in s184 it says which do you mean + + + align:start position:0% +i type in s184 it says which do you mean +the human the mouse and the rat well we + + align:start position:0% +the human the mouse and the rat well we + + + align:start position:0% +the human the mouse and the rat well we +started with the wrap but let's see + + align:start position:0% +started with the wrap but let's see + + + align:start position:0% +started with the wrap but let's see +where the human ones are expressed click + + align:start position:0% +where the human ones are expressed click + + + align:start position:0% +where the human ones are expressed click +on that + + align:start position:0% +on that + + + align:start position:0% +on that +is measured in 10 microarrays by johns + + align:start position:0% +is measured in 10 microarrays by johns + + + align:start position:0% +is measured in 10 microarrays by johns +hopkins that's not that many let's go + + align:start position:0% +hopkins that's not that many let's go + + + align:start position:0% +hopkins that's not that many let's go +back let's look at the mouse one mouse + + align:start position:0% +back let's look at the mouse one mouse + + + align:start position:0% +back let's look at the mouse one mouse +is measured 142 by this group 100 by + + align:start position:0% +is measured 142 by this group 100 by + + + align:start position:0% +is measured 142 by this group 100 by +this group 84 by this group let's look + + align:start position:0% +this group 84 by this group let's look + + + align:start position:0% +this group 84 by this group let's look +at the 84 first + + align:start position:0% +at the 84 first + + + align:start position:0% +at the 84 first +and we can see the top samples okay this + + align:start position:0% +and we can see the top samples okay this + + + align:start position:0% +and we can see the top samples okay this +is the expression level this is the + + align:start position:0% +is the expression level this is the + + + align:start position:0% +is the expression level this is the +percentile of that gene on that chip on + + align:start position:0% +percentile of that gene on that chip on + + + align:start position:0% +percentile of that gene on that chip on +each chip + + align:start position:0% +each chip + + + align:start position:0% +each chip +muscle muscle muscle muscle muscle + + align:start position:0% +muscle muscle muscle muscle muscle + + + align:start position:0% +muscle muscle muscle muscle muscle +muscle muscle muscle + + align:start position:0% +muscle muscle muscle + + + align:start position:0% +muscle muscle muscle +at least for johns hopkins this gene is + + align:start position:0% +at least for johns hopkins this gene is + + + align:start position:0% +at least for johns hopkins this gene is +most highly expressed in their muscle + + align:start position:0% +most highly expressed in their muscle + + + align:start position:0% +most highly expressed in their muscle +samples specifically regenerating muscle + + align:start position:0% +samples specifically regenerating muscle + + + align:start position:0% +samples specifically regenerating muscle +we can look to see exactly what sample + + align:start position:0% +we can look to see exactly what sample + + + align:start position:0% +we can look to see exactly what sample +there is but let's go on let's hit the + + align:start position:0% +there is but let's go on let's hit the + + + align:start position:0% +there is but let's go on let's hit the +back button + + align:start position:0% +back button + + + align:start position:0% +back button +and let's look at cardiogenomics this is + + align:start position:0% +and let's look at cardiogenomics this is + + + align:start position:0% +and let's look at cardiogenomics this is +these guys at the beth israel + + align:start position:0% +these guys at the beth israel + + + align:start position:0% +these guys at the beth israel +and again + + align:start position:0% +and again + + + align:start position:0% +and again +it's highly expressed in banded smooth + + align:start position:0% +it's highly expressed in banded smooth + + + align:start position:0% +it's highly expressed in banded smooth +muscle now it says band here + + align:start position:0% +muscle now it says band here + + + align:start position:0% +muscle now it says band here +that's banned 48 hours banned 48 hours + + align:start position:0% +that's banned 48 hours banned 48 hours + + + align:start position:0% +that's banned 48 hours banned 48 hours +24 hours what exactly did they do what + + align:start position:0% +24 hours what exactly did they do what + + + align:start position:0% +24 hours what exactly did they do what +exactly are these samples you click on + + align:start position:0% +exactly are these samples you click on + + + align:start position:0% +exactly are these samples you click on +overview it takes you to their website + + align:start position:0% +overview it takes you to their website + + + align:start position:0% +overview it takes you to their website +that tells you what was the experiment + + align:start position:0% +that tells you what was the experiment + + + align:start position:0% +that tells you what was the experiment +they did they actually did an experiment + + align:start position:0% +they did they actually did an experiment + + + align:start position:0% +they did they actually did an experiment +where they took these mice + + align:start position:0% +where they took these mice + + + align:start position:0% +where they took these mice +they opened them up + + align:start position:0% +they opened them up + + + align:start position:0% +they opened them up +and they put a little rubber band on + + align:start position:0% +and they put a little rubber band on + + + align:start position:0% +and they put a little rubber band on +their aortics + + align:start position:0% +their aortics + + + align:start position:0% +their aortics +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and half of them the other have to just + + align:start position:0% +and half of them the other have to just + + + align:start position:0% +and half of them the other have to just +sew them up again they didn't do + + align:start position:0% +sew them up again they didn't do + + + align:start position:0% +sew them up again they didn't do +anything and so they made a list of + + align:start position:0% +anything and so they made a list of + + + align:start position:0% +anything and so they made a list of +genes that go up in the heart + + align:start position:0% +genes that go up in the heart + + + align:start position:0% +genes that go up in the heart +as a response to this pressure overload + + align:start position:0% +as a response to this pressure overload + + + align:start position:0% +as a response to this pressure overload +the genes are sitting there and i can + + align:start position:0% +the genes are sitting there and i can + + + align:start position:0% +the genes are sitting there and i can +guarantee you again not a single paper + + align:start position:0% +guarantee you again not a single paper + + + align:start position:0% +guarantee you again not a single paper +has been published on this list + + align:start position:0% +has been published on this list + + + align:start position:0% +has been published on this list +because we're so busy creating more data + + align:start position:0% +because we're so busy creating more data + + + align:start position:0% +because we're so busy creating more data +we have not had time to publish anything + + align:start position:0% +we have not had time to publish anything + + + align:start position:0% +we have not had time to publish anything +on this data + + align:start position:0% +on this data + + + align:start position:0% +on this data +so they were studying trying to study + + align:start position:0% +so they were studying trying to study + + + align:start position:0% +so they were studying trying to study +pressure overload induced cardiac + + align:start position:0% +pressure overload induced cardiac + + + align:start position:0% +pressure overload induced cardiac +hypertrophy so now here's the hypothesis + + align:start position:0% +hypertrophy so now here's the hypothesis + + + align:start position:0% +hypertrophy so now here's the hypothesis +i started + + align:start position:0% +i started + + + align:start position:0% +i started +with the brown orange rat and the brown + + align:start position:0% +with the brown orange rat and the brown + + + align:start position:0% +with the brown orange rat and the brown +already rat has signs of diabetes + + align:start position:0% +already rat has signs of diabetes + + + align:start position:0% +already rat has signs of diabetes +because of this gene s1 or a4 that's + + align:start position:0% +because of this gene s1 or a4 that's + + + align:start position:0% +because of this gene s1 or a4 that's +because s100 a4 was under that + + align:start position:0% +because s100 a4 was under that + + + align:start position:0% +because s100 a4 was under that +significance peak but i think it's + + align:start position:0% +significance peak but i think it's + + + align:start position:0% +significance peak but i think it's +because s1 or a4 is expressed in muscle + + align:start position:0% +because s1 or a4 is expressed in muscle + + + align:start position:0% +because s1 or a4 is expressed in muscle +under a variety of different conditions + + align:start position:0% +under a variety of different conditions + + + align:start position:0% +under a variety of different conditions +and i know muscle is an insulin target + + align:start position:0% +and i know muscle is an insulin target + + + align:start position:0% +and i know muscle is an insulin target +tissue + + align:start position:0% +tissue + + + align:start position:0% +tissue +so now i can get some clue as to what + + align:start position:0% +so now i can get some clue as to what + + + align:start position:0% +so now i can get some clue as to what +experiment i can do next maybe i should + + align:start position:0% +experiment i can do next maybe i should + + + align:start position:0% +experiment i can do next maybe i should +go look at muscle cells for s1 or a4 + + align:start position:0% +go look at muscle cells for s1 or a4 + + + align:start position:0% +go look at muscle cells for s1 or a4 +if you actually do pubmed searches you + + align:start position:0% +if you actually do pubmed searches you + + + align:start position:0% +if you actually do pubmed searches you +can see s194 is associated at least it's + + align:start position:0% +can see s194 is associated at least it's + + + align:start position:0% +can see s194 is associated at least it's +being studied in diabetes today + + align:start position:0% +being studied in diabetes today + + + align:start position:0% +being studied in diabetes today +now i just picked the first peak i saw + + align:start position:0% +now i just picked the first peak i saw + + + align:start position:0% +now i just picked the first peak i saw +on that website okay you can go back and + + align:start position:0% +on that website okay you can go back and + + + align:start position:0% +on that website okay you can go back and +find any number of new genes there and + + align:start position:0% +find any number of new genes there and + + + align:start position:0% +find any number of new genes there and +come up with hypotheses and we didn't + + align:start position:0% +come up with hypotheses and we didn't + + + align:start position:0% +come up with hypotheses and we didn't +even leave the web browser + + align:start position:0% +even leave the web browser + + + align:start position:0% +even leave the web browser +okay you didn't even have to download a + + align:start position:0% +okay you didn't even have to download a + + + align:start position:0% +okay you didn't even have to download a +file to do any of this so you could do + + align:start position:0% +file to do any of this so you could do + + + align:start position:0% +file to do any of this so you could do +this today yourself just surfing from + + align:start position:0% +this today yourself just surfing from + + + align:start position:0% +this today yourself just surfing from +one of these sites to another from + + align:start position:0% +one of these sites to another from + + + align:start position:0% +one of these sites to another from +something you might have heard down the + + align:start position:0% +something you might have heard down the + + + align:start position:0% +something you might have heard down the +hall it's my actual hypothesis + + align:start position:0% + + + + align:start position:0% + +we have about 10 minutes i'm just going + + align:start position:0% +we have about 10 minutes i'm just going + + + align:start position:0% +we have about 10 minutes i'm just going +to call it quits now to see if you have + + align:start position:0% +to call it quits now to see if you have + + + align:start position:0% +to call it quits now to see if you have +any questions + + align:start position:0% + + + + align:start position:0% + +or thoughts + + align:start position:0% + + + + align:start position:0% + +so what at what point + + align:start position:0% +so what at what point + + + align:start position:0% +so what at what point +these various websites after data what + + align:start position:0% +these various websites after data what + + + align:start position:0% +these various websites after data what +point does that data get put on the + + align:start position:0% +point does that data get put on the + + + align:start position:0% +point does that data get put on the +website or after publication + + align:start position:0% +website or after publication + + + align:start position:0% +website or after publication +good question + + align:start position:0% + + + + align:start position:0% + +great question so ncbi geo you can + + align:start position:0% +great question so ncbi geo you can + + + align:start position:0% +great question so ncbi geo you can +submit data to them and then they'll + + align:start position:0% +submit data to them and then they'll + + + align:start position:0% +submit data to them and then they'll +keep it hidden until you say it's been + + align:start position:0% +keep it hidden until you say it's been + + + align:start position:0% +keep it hidden until you say it's been +published and then they can turn it on + + align:start position:0% +published and then they can turn it on + + + align:start position:0% +published and then they can turn it on +these other personal websites like the + + align:start position:0% +these other personal websites like the + + + align:start position:0% +these other personal websites like the +whitehead one stanford they typically + + align:start position:0% +whitehead one stanford they typically + + + align:start position:0% +whitehead one stanford they typically +appear after publication + + align:start position:0% +appear after publication + + + align:start position:0% +appear after publication +for these other websites in this pga + + align:start position:0% +for these other websites in this pga + + + align:start position:0% +for these other websites in this pga +these the the cardiovascular data keep + + align:start position:0% +these the the cardiovascular data keep + + + align:start position:0% +these the the cardiovascular data keep +showing you that data appears within 60 + + align:start position:0% +showing you that data appears within 60 + + + align:start position:0% +showing you that data appears within 60 +days of its creation regardless of + + align:start position:0% +days of its creation regardless of + + + align:start position:0% +days of its creation regardless of +publication + + align:start position:0% +publication + + + align:start position:0% +publication +nih is more and more mandating that to + + align:start position:0% +nih is more and more mandating that to + + + align:start position:0% +nih is more and more mandating that to +be the model now okay + + align:start position:0% +be the model now okay + + + align:start position:0% +be the model now okay +because if they're paying for all this + + align:start position:0% +because if they're paying for all this + + + align:start position:0% +because if they're paying for all this +genomic work + + align:start position:0% +genomic work + + + align:start position:0% +genomic work +they don't want just one lab to to + + align:start position:0% +they don't want just one lab to to + + + align:start position:0% +they don't want just one lab to to +really be able to run with it because + + align:start position:0% +really be able to run with it because + + + align:start position:0% +really be able to run with it because +there's too much data for any one lab to + + align:start position:0% +there's too much data for any one lab to + + + align:start position:0% +there's too much data for any one lab to +deal with so they as for some of their + + align:start position:0% +deal with so they as for some of their + + + align:start position:0% +deal with so they as for some of their +grants they actually insist that this + + align:start position:0% +grants they actually insist that this + + + align:start position:0% +grants they actually insist that this +data be made available well before + + align:start position:0% +data be made available well before + + + align:start position:0% +data be made available well before +publication + + align:start position:0% +publication + + + align:start position:0% +publication +so right now cardiovascular and lung + + align:start position:0% +so right now cardiovascular and lung + + + align:start position:0% +so right now cardiovascular and lung +disease + + align:start position:0% +disease + + + align:start position:0% +disease +and some a little bit of sleep as well + + align:start position:0% +and some a little bit of sleep as well + + + align:start position:0% +and some a little bit of sleep as well +you can get a lot of data + + align:start position:0% +you can get a lot of data + + + align:start position:0% +you can get a lot of data +1500 arrays + + align:start position:0% + + + + align:start position:0% + +yep these pga these programs and genomic + + align:start position:0% +yep these pga these programs and genomic + + + align:start position:0% +yep these pga these programs and genomic +applications pga was funded by the heart + + align:start position:0% +applications pga was funded by the heart + + + align:start position:0% +applications pga was funded by the heart +lung and blood institute that in + + align:start position:0% +lung and blood institute that in + + + align:start position:0% +lung and blood institute that in +particular has a lot of data that's + + align:start position:0% +particular has a lot of data that's + + + align:start position:0% +particular has a lot of data that's +already available hasn't been published + + align:start position:0% +already available hasn't been published + + + align:start position:0% +already available hasn't been published +on \ No newline at end of file diff --git a/MeFCYYCATw0.txt b/MeFCYYCATw0.txt new file mode 100644 index 0000000000000000000000000000000000000000..5aa936717432c5beaf17f25e9cb9c9d313488822 --- /dev/null +++ b/MeFCYYCATw0.txt @@ -0,0 +1,14055 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +to view additional materials from + + align:start position:0% +to view additional materials from + + + align:start position:0% +to view additional materials from +hundreds of MIT courses visit MIT open + + align:start position:0% +hundreds of MIT courses visit MIT open + + + align:start position:0% +hundreds of MIT courses visit MIT open +courseware at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu okay as you'll see with + + align:start position:0% +ocw.mit.edu okay as you'll see with + + + align:start position:0% +ocw.mit.edu okay as you'll see with +today's uh lecture I made a small change + + align:start position:0% +today's uh lecture I made a small change + + + align:start position:0% +today's uh lecture I made a small change +in the uh lecture sequence I basically + + align:start position:0% +in the uh lecture sequence I basically + + + align:start position:0% +in the uh lecture sequence I basically +combined the last part of of Tuesday's + + align:start position:0% +combined the last part of of Tuesday's + + + align:start position:0% +combined the last part of of Tuesday's +lecture with what I was going to talk + + align:start position:0% +lecture with what I was going to talk + + + align:start position:0% +lecture with what I was going to talk +about next week because they really go + + align:start position:0% +about next week because they really go + + + align:start position:0% +about next week because they really go +together better anyway which is multiv + + align:start position:0% +together better anyway which is multiv + + + align:start position:0% +together better anyway which is multiv +at SPC together with a couple of the + + align:start position:0% +at SPC together with a couple of the + + + align:start position:0% +at SPC together with a couple of the +advanced control charting and so next + + align:start position:0% +advanced control charting and so next + + + align:start position:0% +advanced control charting and so next +week we'll do the uh yield modeling uh + + align:start position:0% +week we'll do the uh yield modeling uh + + + align:start position:0% +week we'll do the uh yield modeling uh +lecture rather than uh rather than try + + align:start position:0% +lecture rather than uh rather than try + + + align:start position:0% +lecture rather than uh rather than try +to squish that in today so what I want + + align:start position:0% +to squish that in today so what I want + + + align:start position:0% +to squish that in today so what I want +to do today is first have a very brief + + align:start position:0% +to do today is first have a very brief + + + align:start position:0% +to do today is first have a very brief +warmup just get us back into the swing + + align:start position:0% +warmup just get us back into the swing + + + align:start position:0% +warmup just get us back into the swing +of things with conventional control + + align:start position:0% +of things with conventional control + + + align:start position:0% +of things with conventional control +charts and then talk a little bit about + + align:start position:0% +charts and then talk a little bit about + + + align:start position:0% +charts and then talk a little bit about +these alternative control charts with a + + align:start position:0% +these alternative control charts with a + + + align:start position:0% +these alternative control charts with a +little bit of increased sensitivity for + + align:start position:0% +little bit of increased sensitivity for + + + align:start position:0% +little bit of increased sensitivity for +Rapid detection of of of shifts uh as + + align:start position:0% +Rapid detection of of of shifts uh as + + + align:start position:0% +Rapid detection of of of shifts uh as +well as as drifts but primarily uh + + align:start position:0% +well as as drifts but primarily uh + + + align:start position:0% +well as as drifts but primarily uh +targeted at shifts and these are the + + align:start position:0% +targeted at shifts and these are the + + + align:start position:0% +targeted at shifts and these are the +moving average exponentially weighted + + align:start position:0% +moving average exponentially weighted + + + align:start position:0% +moving average exponentially weighted +moving average in the cumulative sum + + align:start position:0% +moving average in the cumulative sum + + + align:start position:0% +moving average in the cumulative sum +chart and then we'll move into uh + + align:start position:0% +chart and then we'll move into uh + + + align:start position:0% +chart and then we'll move into uh +multivariate + + align:start position:0% +multivariate + + + align:start position:0% +multivariate +SPC uh which is a little bit of a + + align:start position:0% +SPC uh which is a little bit of a + + + align:start position:0% +SPC uh which is a little bit of a +tutorial on multivariate uh statistics + + align:start position:0% +tutorial on multivariate uh statistics + + + align:start position:0% +tutorial on multivariate uh statistics +in general + + align:start position:0% +in general + + + align:start position:0% +in general +so that's the plan so to get us warmed + + align:start position:0% +so that's the plan so to get us warmed + + + align:start position:0% +so that's the plan so to get us warmed +up we'll do a rapid design of a control + + align:start position:0% +up we'll do a rapid design of a control + + + align:start position:0% +up we'll do a rapid design of a control +chart how to do this uh relatively + + align:start position:0% +chart how to do this uh relatively + + + align:start position:0% +chart how to do this uh relatively +quickly I will tell you what that we + + align:start position:0% +quickly I will tell you what that we + + + align:start position:0% +quickly I will tell you what that we +have a model based on lots of historical + + align:start position:0% +have a model based on lots of historical + + + align:start position:0% +have a model based on lots of historical +data of this process that when it is in + + align:start position:0% +data of this process that when it is in + + + align:start position:0% +data of this process that when it is in +control it's operating as a normally + + align:start position:0% +control it's operating as a normally + + + align:start position:0% +control it's operating as a normally +distributed process with a mean of one + + align:start position:0% +distributed process with a mean of one + + + align:start position:0% +distributed process with a mean of one +and a variance of one we're going to be + + align:start position:0% +and a variance of one we're going to be + + + align:start position:0% +and a variance of one we're going to be +taking samples every nine parts then the + + align:start position:0% +taking samples every nine parts then the + + + align:start position:0% +taking samples every nine parts then the +next nine and so on + + align:start position:0% +next nine and so on + + + align:start position:0% +next nine and so on +so what should the here's the easy one + + align:start position:0% +so what should the here's the easy one + + + align:start position:0% +so what should the here's the easy one +to make wake you up in the morning what + + align:start position:0% +to make wake you up in the morning what + + + align:start position:0% +to make wake you up in the morning what +should the center line + + align:start position:0% +should the center line + + + align:start position:0% +should the center line +be five okay everybody how about the + + align:start position:0% +be five okay everybody how about the + + + align:start position:0% +be five okay everybody how about the +plusus 3 Sigma we're quite quite happy + + align:start position:0% +plusus 3 Sigma we're quite quite happy + + + align:start position:0% +plusus 3 Sigma we're quite quite happy +with the uh 1 and 370 + + align:start position:0% +with the uh 1 and 370 + + + align:start position:0% +with the uh 1 and 370 +ARL uh with normal typical plusus 3 + + align:start position:0% +ARL uh with normal typical plusus 3 + + + align:start position:0% +ARL uh with normal typical plusus 3 +Sigma control limits where should the + + align:start position:0% +Sigma control limits where should the + + + align:start position:0% +Sigma control limits where should the +plusus 3 Sigma control limits be + + align:start position:0% + + + + align:start position:0% + +I I hear a six and four + + align:start position:0% + + + + align:start position:0% + +why I'm + + align:start position:0% +why I'm + + + align:start position:0% +why I'm +sorry okay which + + align:start position:0% + + + + align:start position:0% + +is uh mu plus Sigma plusus three + + align:start position:0% +is uh mu plus Sigma plusus three + + + align:start position:0% +is uh mu plus Sigma plusus three +sigma three sigma over square root of + + align:start position:0% +sigma three sigma over square root of + + + align:start position:0% +sigma three sigma over square root of +sample size n so the three sigma and the + + align:start position:0% +sample size n so the three sigma and the + + + align:start position:0% +sample size n so the three sigma and the +three which comes from the root n and + + align:start position:0% +three which comes from the root n and + + + align:start position:0% +three which comes from the root n and +make it a nice uh plusus one and there's + + align:start position:0% +make it a nice uh plusus one and there's + + + align:start position:0% +make it a nice uh plusus one and there's +some data okay so i' I've plotted 99 we + + align:start position:0% +some data okay so i' I've plotted 99 we + + + align:start position:0% +some data okay so i' I've plotted 99 we +we ran the process 99 runs they have 11 + + align:start position:0% +we ran the process 99 runs they have 11 + + + align:start position:0% +we ran the process 99 runs they have 11 +samples here's the question is the + + align:start position:0% +samples here's the question is the + + + align:start position:0% +samples here's the question is the +process in + + align:start position:0% + + + + align:start position:0% + +control we have a + + align:start position:0% +control we have a + + + align:start position:0% +control we have a +yes we have another yes + + align:start position:0% + + + + align:start position:0% + +I contend you don't + + align:start position:0% + + + + align:start position:0% + +know it's a little bit tricky + + align:start position:0% +know it's a little bit tricky + + + align:start position:0% +know it's a little bit tricky +here liit and + + align:start position:0% +here liit and + + + align:start position:0% +here liit and +see yeah I guess uh that's actually not + + align:start position:0% +see yeah I guess uh that's actually not + + + align:start position:0% +see yeah I guess uh that's actually not +what I have in mind you could go in and + + align:start position:0% +what I have in mind you could go in and + + + align:start position:0% +what I have in mind you could go in and +start uh down the path of looking and + + align:start position:0% +start uh down the path of looking and + + + align:start position:0% +start uh down the path of looking and +saying okay what's the probability of + + align:start position:0% +saying okay what's the probability of + + + align:start position:0% +saying okay what's the probability of +having for example three Rising points + + align:start position:0% +having for example three Rising points + + + align:start position:0% +having for example three Rising points +in a row and all the other Western but + + align:start position:0% +in a row and all the other Western but + + + align:start position:0% +in a row and all the other Western but +but uh I'll I'll + + align:start position:0% +but uh I'll I'll + + + align:start position:0% +but uh I'll I'll +say none of that's + + align:start position:0% +say none of that's + + + align:start position:0% +say none of that's +happening so I I will say that the + + align:start position:0% +happening so I I will say that the + + + align:start position:0% +happening so I I will say that the +mean there's nothing too strange + + align:start position:0% +mean there's nothing too strange + + + align:start position:0% +mean there's nothing too strange +happening with the mean that you can + + align:start position:0% +happening with the mean that you can + + + align:start position:0% +happening with the mean that you can +tell with this chart is the process in + + align:start position:0% +tell with this chart is the process in + + + align:start position:0% +tell with this chart is the process in +control like a + + align:start position:0% +control like a + + + align:start position:0% +control like a +Vari yeah Vari is getting compar to + + align:start position:0% +Vari yeah Vari is getting compar to + + + align:start position:0% +Vari yeah Vari is getting compar to +earlier points oh so you're saying the + + align:start position:0% +earlier points oh so you're saying the + + + align:start position:0% +earlier points oh so you're saying the +variance is getting + + align:start position:0% +variance is getting + + + align:start position:0% +variance is getting +larger maybe it's hard to tell with this + + align:start position:0% +larger maybe it's hard to tell with this + + + align:start position:0% +larger maybe it's hard to tell with this +this is a mean chart all it's telling + + align:start position:0% +this is a mean chart all it's telling + + + align:start position:0% +this is a mean chart all it's telling +you is a tracking of the mean we said + + align:start position:0% +you is a tracking of the mean we said + + + align:start position:0% +you is a tracking of the mean we said +that the process model is that we have + + align:start position:0% +that the process model is that we have + + + align:start position:0% +that the process model is that we have +this mean and this variance and so I + + align:start position:0% +this mean and this variance and so I + + + align:start position:0% +this mean and this variance and so I +guess the main point here is you don't + + align:start position:0% +guess the main point here is you don't + + + align:start position:0% +guess the main point here is you don't +really know if you're just tracking the + + align:start position:0% +really know if you're just tracking the + + + align:start position:0% +really know if you're just tracking the +mean what's happening also with the + + align:start position:0% +mean what's happening also with the + + + align:start position:0% +mean what's happening also with the +variance within your + + align:start position:0% +variance within your + + + align:start position:0% +variance within your +sample in fact uh on the next page this + + align:start position:0% +sample in fact uh on the next page this + + + align:start position:0% +sample in fact uh on the next page this +is the raw data all 99 points where we + + align:start position:0% +is the raw data all 99 points where we + + + align:start position:0% +is the raw data all 99 points where we +grouped 9 by 9 by9 to get the + + align:start position:0% +grouped 9 by 9 by9 to get the + + + align:start position:0% +grouped 9 by 9 by9 to get the +sample and if you saw this you might be + + align:start position:0% +sample and if you saw this you might be + + + align:start position:0% +sample and if you saw this you might be +a little less comfortable huh + + align:start position:0% +a little less comfortable huh + + + align:start position:0% +a little less comfortable huh +now you could always go back and look at + + align:start position:0% +now you could always go back and look at + + + align:start position:0% +now you could always go back and look at +Raw data and raw data is always really + + align:start position:0% +Raw data and raw data is always really + + + align:start position:0% +Raw data and raw data is always really +good to do but what you would also want + + align:start position:0% +good to do but what you would also want + + + align:start position:0% +good to do but what you would also want +to do is a typical s chart or a range + + align:start position:0% +to do is a typical s chart or a range + + + align:start position:0% +to do is a typical s chart or a range +chart something like that and in this + + align:start position:0% +chart something like that and in this + + + align:start position:0% +chart something like that and in this +case if you design the S chart with + + align:start position:0% +case if you design the S chart with + + + align:start position:0% +case if you design the S chart with +those AR + + align:start position:0% +those AR + + + align:start position:0% +those AR +priori um pieces of data sample size is + + align:start position:0% +priori um pieces of data sample size is + + + align:start position:0% +priori um pieces of data sample size is +nine and the uh process variance is + + align:start position:0% +nine and the uh process variance is + + + align:start position:0% +nine and the uh process variance is +one with the C4 correction factor and so + + align:start position:0% +one with the C4 correction factor and so + + + align:start position:0% +one with the C4 correction factor and so +on all of that just out of the the + + align:start position:0% +on all of that just out of the the + + + align:start position:0% +on all of that just out of the the +formula uh you get these control + + align:start position:0% +formula uh you get these control + + + align:start position:0% +formula uh you get these control +limits and uh sure enough at about uh + + align:start position:0% +limits and uh sure enough at about uh + + + align:start position:0% +limits and uh sure enough at about uh +sample 10 we're above the control limit + + align:start position:0% +sample 10 we're above the control limit + + + align:start position:0% +sample 10 we're above the control limit +sample 11 is even more above the control + + align:start position:0% +sample 11 is even more above the control + + + align:start position:0% +sample 11 is even more above the control +limit and that's indicative of + + align:start position:0% +limit and that's indicative of + + + align:start position:0% +limit and that's indicative of +essentially The increased variance of + + align:start position:0% +essentially The increased variance of + + + align:start position:0% +essentially The increased variance of +those two groups and I will tell you I + + align:start position:0% +those two groups and I will tell you I + + + align:start position:0% +those two groups and I will tell you I +generated this data with jump and sure + + align:start position:0% +generated this data with jump and sure + + + align:start position:0% +generated this data with jump and sure +enough right at the uh whatever it was + + align:start position:0% +enough right at the uh whatever it was + + + align:start position:0% +enough right at the uh whatever it was +the 77th uh point I resampled with a + + align:start position:0% +the 77th uh point I resampled with a + + + align:start position:0% +the 77th uh point I resampled with a +from a normal distribution with + + align:start position:0% +from a normal distribution with + + + align:start position:0% +from a normal distribution with +something like a variance of 1.9 or two + + align:start position:0% +something like a variance of 1.9 or two + + + align:start position:0% +something like a variance of 1.9 or two +or something like that so the main point + + align:start position:0% +or something like that so the main point + + + align:start position:0% +or something like that so the main point +here was you need to monitor both + + align:start position:0% +here was you need to monitor both + + + align:start position:0% +here was you need to monitor both +aspects uh both the mean and the + + align:start position:0% +aspects uh both the mean and the + + + align:start position:0% +aspects uh both the mean and the +variance to know whether your process + + align:start position:0% +variance to know whether your process + + + align:start position:0% +variance to know whether your process +model is is is still operative are we uh + + align:start position:0% +model is is is still operative are we uh + + + align:start position:0% +model is is is still operative are we uh +we're saying that for a normal + + align:start position:0% +we're saying that for a normal + + + align:start position:0% +we're saying that for a normal +distribution the mean and variance are + + align:start position:0% +distribution the mean and variance are + + + align:start position:0% +distribution the mean and variance are +really telling you + + align:start position:0% +really telling you + + + align:start position:0% +really telling you +everything now the other subo in here is + + align:start position:0% +everything now the other subo in here is + + + align:start position:0% +everything now the other subo in here is +that if you were actually looking at + + align:start position:0% +that if you were actually looking at + + + align:start position:0% +that if you were actually looking at +this run data there is a lot of noise + + align:start position:0% +this run data there is a lot of noise + + + align:start position:0% +this run data there is a lot of noise +there's inherent process noise and part + + align:start position:0% +there's inherent process noise and part + + + align:start position:0% +there's inherent process noise and part +of the goal here is you're you're trying + + align:start position:0% +of the goal here is you're you're trying + + + align:start position:0% +of the goal here is you're you're trying +to detect a mean in the face of that + + align:start position:0% +to detect a mean in the face of that + + + align:start position:0% +to detect a mean in the face of that +noise and so one way of thinking about + + align:start position:0% +noise and so one way of thinking about + + + align:start position:0% +noise and so one way of thinking about +sampling and calculating xar is that + + align:start position:0% +sampling and calculating xar is that + + + align:start position:0% +sampling and calculating xar is that +indeed you are + + align:start position:0% +indeed you are + + + align:start position:0% +indeed you are +filtering okay so you want to filter to + + align:start position:0% +filtering okay so you want to filter to + + + align:start position:0% +filtering okay so you want to filter to +suppress the additional variance effect + + align:start position:0% +suppress the additional variance effect + + + align:start position:0% +suppress the additional variance effect +when you're looking for the mean Trace + + align:start position:0% +when you're looking for the mean Trace + + + align:start position:0% +when you're looking for the mean Trace +but again you got to also monitor for + + align:start position:0% +but again you got to also monitor for + + + align:start position:0% +but again you got to also monitor for +for the variants but this noise makes it + + align:start position:0% +for the variants but this noise makes it + + + align:start position:0% +for the variants but this noise makes it +a little bit tricky in terms of uh being + + align:start position:0% +a little bit tricky in terms of uh being + + + align:start position:0% +a little bit tricky in terms of uh being +able to detect the mean so you want to + + align:start position:0% +able to detect the mean so you want to + + + align:start position:0% +able to detect the mean so you want to +filter and one of the ideas of these + + align:start position:0% +filter and one of the ideas of these + + + align:start position:0% +filter and one of the ideas of these +alternative control charts is explicitly + + align:start position:0% +alternative control charts is explicitly + + + align:start position:0% +alternative control charts is explicitly +think about the filtering action that + + align:start position:0% +think about the filtering action that + + + align:start position:0% +think about the filtering action that +you're doing a little bit almost from a + + align:start position:0% +you're doing a little bit almost from a + + + align:start position:0% +you're doing a little bit almost from a +more signal processing kind of uh point + + align:start position:0% +more signal processing kind of uh point + + + align:start position:0% +more signal processing kind of uh point +of view but not necessarily have to uh + + align:start position:0% +of view but not necessarily have to uh + + + align:start position:0% +of view but not necessarily have to uh +wait for an additional say nine runs + + align:start position:0% +wait for an additional say nine runs + + + align:start position:0% +wait for an additional say nine runs +before you call that a sample aggregate + + align:start position:0% +before you call that a sample aggregate + + + align:start position:0% +before you call that a sample aggregate +it and then plot it and then wait for + + align:start position:0% +it and then plot it and then wait for + + + align:start position:0% +it and then plot it and then wait for +another nine runs one alternative + + align:start position:0% +another nine runs one alternative + + + align:start position:0% +another nine runs one alternative +approach here is to take a running + + align:start position:0% +approach here is to take a running + + + align:start position:0% +approach here is to take a running +average so I take a window say of nine + + align:start position:0% +average so I take a window say of nine + + + align:start position:0% +average so I take a window say of nine +points and measurements calculate my + + align:start position:0% +points and measurements calculate my + + + align:start position:0% +points and measurements calculate my +statistics and then for each new run + + align:start position:0% +statistics and then for each new run + + + align:start position:0% +statistics and then for each new run +move my window over and recalculate my + + align:start position:0% +move my window over and recalculate my + + + align:start position:0% +move my window over and recalculate my +statistics so that I'm in some sense up + + align:start position:0% +statistics so that I'm in some sense up + + + align:start position:0% +statistics so that I'm in some sense up +dating what uh my best guess of the + + align:start position:0% +dating what uh my best guess of the + + + align:start position:0% +dating what uh my best guess of the +current state of the process is after + + align:start position:0% +current state of the process is after + + + align:start position:0% +current state of the process is after +every after every run and the advantages + + align:start position:0% +every after every run and the advantages + + + align:start position:0% +every after every run and the advantages +of this are that you can get more + + align:start position:0% +of this are that you can get more + + + align:start position:0% +of this are that you can get more +averages per unit of + + align:start position:0% +averages per unit of + + + align:start position:0% +averages per unit of +data okay um you can go ahead and run uh + + align:start position:0% +data okay um you can go ahead and run uh + + + align:start position:0% +data okay um you can go ahead and run uh +use the Run data + + align:start position:0% +use the Run data + + + align:start position:0% +use the Run data +Alone um if you wanted to you could + + align:start position:0% +Alone um if you wanted to you could + + + align:start position:0% +Alone um if you wanted to you could +actually plot for + + align:start position:0% +actually plot for + + + align:start position:0% +actually plot for +example uh the individual measurements + + align:start position:0% +example uh the individual measurements + + + align:start position:0% +example uh the individual measurements +and even do a hybrid sort of thing where + + align:start position:0% +and even do a hybrid sort of thing where + + + align:start position:0% +and even do a hybrid sort of thing where +you you did a running average just for + + align:start position:0% +you you did a running average just for + + + align:start position:0% +you you did a running average just for +the standard + + align:start position:0% +the standard + + + align:start position:0% +the standard +deviation but the real advantage of + + align:start position:0% +deviation but the real advantage of + + + align:start position:0% +deviation but the real advantage of +these is they essentially improve your + + align:start position:0% +these is they essentially improve your + + + align:start position:0% +these is they essentially improve your +ability to detect they improve the + + align:start position:0% +ability to detect they improve the + + + align:start position:0% +ability to detect they improve the +filtering action potentially because you + + align:start position:0% +filtering action potentially because you + + + align:start position:0% +filtering action potentially because you +can play with that window size to uh + + align:start position:0% +can play with that window size to uh + + + align:start position:0% +can play with that window size to uh +filter more but also be able to react + + align:start position:0% +filter more but also be able to react + + + align:start position:0% +filter more but also be able to react +potentially faster so I'm going to + + align:start position:0% +potentially faster so I'm going to + + + align:start position:0% +potentially faster so I'm going to +describe a couple of these alternative + + align:start position:0% +describe a couple of these alternative + + + align:start position:0% +describe a couple of these alternative +uh charts and I'm going to focus really + + align:start position:0% +uh charts and I'm going to focus really + + + align:start position:0% +uh charts and I'm going to focus really +on the running average average detection + + align:start position:0% +on the running average average detection + + + align:start position:0% +on the running average average detection +of the mean but the same idea also + + align:start position:0% +of the mean but the same idea also + + + align:start position:0% +of the mean but the same idea also +applies to filtering of the variant + + align:start position:0% +applies to filtering of the variant + + + align:start position:0% +applies to filtering of the variant +across multiple runs so there's + + align:start position:0% +across multiple runs so there's + + + align:start position:0% +across multiple runs so there's +also running s charts or running moving + + align:start position:0% +also running s charts or running moving + + + align:start position:0% +also running s charts or running moving +uh range charts and those sorts of + + align:start position:0% +uh range charts and those sorts of + + + align:start position:0% +uh range charts and those sorts of +things uh so don't forget the lesson we + + align:start position:0% +things uh so don't forget the lesson we + + + align:start position:0% +things uh so don't forget the lesson we +just learned a minute ago you got to + + align:start position:0% +just learned a minute ago you got to + + + align:start position:0% +just learned a minute ago you got to +monitor both mean and variance but for + + align:start position:0% +monitor both mean and variance but for + + + align:start position:0% +monitor both mean and variance but for +the for the next 10 15 slides I'm only + + align:start position:0% +the for the next 10 15 slides I'm only + + + align:start position:0% +the for the next 10 15 slides I'm only +going to talk talk about running + + align:start position:0% +going to talk talk about running + + + align:start position:0% +going to talk talk about running +averages on the on the + + align:start position:0% +averages on the on the + + + align:start position:0% +averages on the on the +average so one uh idea of the running + + align:start position:0% +average so one uh idea of the running + + + align:start position:0% +average so one uh idea of the running +average is a simple running average or + + align:start position:0% +average is a simple running average or + + + align:start position:0% +average is a simple running average or +or moving average where we'd simply take + + align:start position:0% +or moving average where we'd simply take + + + align:start position:0% +or moving average where we'd simply take +some uh n values of the past and + + align:start position:0% +some uh n values of the past and + + + align:start position:0% +some uh n values of the past and +calculate say a simple average and + + align:start position:0% +calculate say a simple average and + + + align:start position:0% +calculate say a simple average and +similarly we could do that for the + + align:start position:0% +similarly we could do that for the + + + align:start position:0% +similarly we could do that for the +variance so in that case this simplest + + align:start position:0% +variance so in that case this simplest + + + align:start position:0% +variance so in that case this simplest +picture this simple moving average is + + align:start position:0% +picture this simple moving average is + + + align:start position:0% +picture this simple moving average is +just a an equally weighted window you + + align:start position:0% +just a an equally weighted window you + + + align:start position:0% +just a an equally weighted window you +you pick your window size maybe it's + + align:start position:0% +you pick your window size maybe it's + + + align:start position:0% +you pick your window size maybe it's +a window size of nine and you calculate + + align:start position:0% +a window size of nine and you calculate + + + align:start position:0% +a window size of nine and you calculate +a new moving average statistic which + + align:start position:0% +a new moving average statistic which + + + align:start position:0% +a new moving average statistic which +I've labeled M subi here and so that's + + align:start position:0% +I've labeled M subi here and so that's + + + align:start position:0% +I've labeled M subi here and so that's +pretty trivial formula now how do you + + align:start position:0% +pretty trivial formula now how do you + + + align:start position:0% +pretty trivial formula now how do you +set the control limits on a moving + + align:start position:0% +set the control limits on a moving + + + align:start position:0% +set the control limits on a moving +average + + align:start position:0% +average + + + align:start position:0% +average +chart well you want plusus 3 Sigma say + + align:start position:0% +chart well you want plusus 3 Sigma say + + + align:start position:0% +chart well you want plusus 3 Sigma say +control limits based on the variance + + align:start position:0% +control limits based on the variance + + + align:start position:0% +control limits based on the variance +that you expect in your statistic right + + align:start position:0% +that you expect in your statistic right + + + align:start position:0% +that you expect in your statistic right +so previously would have sample + + align:start position:0% +so previously would have sample + + + align:start position:0% +so previously would have sample +size of of nine and we'd say well what + + align:start position:0% +size of of nine and we'd say well what + + + align:start position:0% +size of of nine and we'd say well what +the what's the variance it's one over + + align:start position:0% +the what's the variance it's one over + + + align:start position:0% +the what's the variance it's one over +it's Sigma over root n is the standard + + align:start position:0% +it's Sigma over root n is the standard + + + align:start position:0% +it's Sigma over root n is the standard +deviation associated with that move with + + align:start position:0% +deviation associated with that move with + + + align:start position:0% +deviation associated with that move with +with our normal sample size and that + + align:start position:0% +with our normal sample size and that + + + align:start position:0% +with our normal sample size and that +same formula ends up working here + + align:start position:0% +same formula ends up working here + + + align:start position:0% +same formula ends up working here +because we've got equal weighting right + + align:start position:0% +because we've got equal weighting right + + + align:start position:0% +because we've got equal weighting right +so if we simply + + align:start position:0% +so if we simply + + + align:start position:0% +so if we simply +apply uh again assuming uh not assuming + + align:start position:0% +apply uh again assuming uh not assuming + + + align:start position:0% +apply uh again assuming uh not assuming +each of the points are truly in process + + align:start position:0% +each of the points are truly in process + + + align:start position:0% +each of the points are truly in process +control and I do not have correlation in + + align:start position:0% +control and I do not have correlation in + + + align:start position:0% +control and I do not have correlation in +time between them uh it's it's very easy + + align:start position:0% +time between them uh it's it's very easy + + + align:start position:0% +time between them uh it's it's very easy +to see what the variance is now you'll + + align:start position:0% +to see what the variance is now you'll + + + align:start position:0% +to see what the variance is now you'll +notice something a little strange right + + align:start position:0% +notice something a little strange right + + + align:start position:0% +notice something a little strange right +here at the + + align:start position:0% +here at the + + + align:start position:0% +here at the +beginning this is kind of an artifact of + + align:start position:0% +beginning this is kind of an artifact of + + + align:start position:0% +beginning this is kind of an artifact of +the startup of the of the chart let's + + align:start position:0% +the startup of the of the chart let's + + + align:start position:0% +the startup of the of the chart let's +say I have just started the use of the + + align:start position:0% +say I have just started the use of the + + + align:start position:0% +say I have just started the use of the +control chart and I've only got five + + align:start position:0% +control chart and I've only got five + + + align:start position:0% +control chart and I've only got five +samples so far but I've got a moving + + align:start position:0% +samples so far but I've got a moving + + + align:start position:0% +samples so far but I've got a moving +average window of + + align:start position:0% +average window of + + + align:start position:0% +average window of +nine well I don't have nine data points + + align:start position:0% +nine well I don't have nine data points + + + align:start position:0% +nine well I don't have nine data points +yet I have to my moving average really + + align:start position:0% +yet I have to my moving average really + + + align:start position:0% +yet I have to my moving average really +with a window size only of five so far + + align:start position:0% +with a window size only of five so far + + + align:start position:0% +with a window size only of five so far +and because I'm taking the variance + + align:start position:0% +and because I'm taking the variance + + + align:start position:0% +and because I'm taking the variance +divided by five instead of divided by + + align:start position:0% +divided by five instead of divided by + + + align:start position:0% +divided by five instead of divided by +9 the variance of my average of a + + align:start position:0% +9 the variance of my average of a + + + align:start position:0% +9 the variance of my average of a +fivepoint sample is larger and you can + + align:start position:0% +fivepoint sample is larger and you can + + + align:start position:0% +fivepoint sample is larger and you can +see essentially each sample until I get + + align:start position:0% +see essentially each sample until I get + + + align:start position:0% +see essentially each sample until I get +to my full window size of nine has + + align:start position:0% +to my full window size of nine has + + + align:start position:0% +to my full window size of nine has +slightly larger control chart limits + + align:start position:0% +slightly larger control chart limits + + + align:start position:0% +slightly larger control chart limits +okay so that's what's going on + + align:start position:0% +okay so that's what's going on + + + align:start position:0% +okay so that's what's going on +there okay and you can also sort of see + + align:start position:0% +there okay and you can also sort of see + + + align:start position:0% +there okay and you can also sort of see +here now the filtering action at work + + align:start position:0% +here now the filtering action at work + + + align:start position:0% +here now the filtering action at work +notice + + align:start position:0% +notice + + + align:start position:0% +notice +that uh each of these each of these + + align:start position:0% +that uh each of these each of these + + + align:start position:0% +that uh each of these each of these +samples don't vary dramatically from the + + align:start position:0% +samples don't vary dramatically from the + + + align:start position:0% +samples don't vary dramatically from the +from the previous one they are no longer + + align:start position:0% +from the previous one they are no longer + + + align:start position:0% +from the previous one they are no longer +uncorrelated from one sample to the next + + align:start position:0% +uncorrelated from one sample to the next + + + align:start position:0% +uncorrelated from one sample to the next +in fact with this equal waiting you know + + align:start position:0% +in fact with this equal waiting you know + + + align:start position:0% +in fact with this equal waiting you know +every new time Point + + align:start position:0% +every new time Point + + + align:start position:0% +every new time Point +shares + + align:start position:0% +shares + + + align:start position:0% +shares +88% of the data with the pr previous + + align:start position:0% +88% of the data with the pr previous + + + align:start position:0% +88% of the data with the pr previous +uh data point so there's a huge amount + + align:start position:0% +uh data point so there's a huge amount + + + align:start position:0% +uh data point so there's a huge amount +of correlation from one point in time + + align:start position:0% +of correlation from one point in time + + + align:start position:0% +of correlation from one point in time +and the next so you should + + align:start position:0% +and the next so you should + + + align:start position:0% +and the next so you should +not try to use things like the weo rules + + align:start position:0% +not try to use things like the weo rules + + + align:start position:0% +not try to use things like the weo rules +associated with three data points in a + + align:start position:0% +associated with three data points in a + + + align:start position:0% +associated with three data points in a +row or four or five data points in a row + + align:start position:0% +row or four or five data points in a row + + + align:start position:0% +row or four or five data points in a row +Rising those things are right out + + align:start position:0% +Rising those things are right out + + + align:start position:0% +Rising those things are right out +because this is a running control chart + + align:start position:0% +because this is a running control chart + + + align:start position:0% +because this is a running control chart +or moving average control chart and + + align:start position:0% +or moving average control chart and + + + align:start position:0% +or moving average control chart and +you've now got correlation its benefit + + align:start position:0% +you've now got correlation its benefit + + + align:start position:0% +you've now got correlation its benefit +though is that it is doing that + + align:start position:0% +though is that it is doing that + + + align:start position:0% +though is that it is doing that +filtering and you + + align:start position:0% +filtering and you + + + align:start position:0% +filtering and you +can take whatever current point that you + + align:start position:0% +can take whatever current point that you + + + align:start position:0% +can take whatever current point that you +get as a sort of your best guess of what + + align:start position:0% +get as a sort of your best guess of what + + + align:start position:0% +get as a sort of your best guess of what +the current state of the uh overall mean + + align:start position:0% +the current state of the uh overall mean + + + align:start position:0% +the current state of the uh overall mean +is and so you would trigger on alarms uh + + align:start position:0% +is and so you would trigger on alarms uh + + + align:start position:0% +is and so you would trigger on alarms uh +above or below the control + + align:start position:0% +above or below the control + + + align:start position:0% +above or below the control +limits + + align:start position:0% +limits + + + align:start position:0% +limits +okay so simple moving average this is + + align:start position:0% +okay so simple moving average this is + + + align:start position:0% +okay so simple moving average this is +relatively simple any questions on this + + align:start position:0% +relatively simple any questions on this + + + align:start position:0% +relatively simple any questions on this +before we do a + + align:start position:0% +before we do a + + + align:start position:0% +before we do a +unequally weighted moving + + align:start position:0% +unequally weighted moving + + + align:start position:0% +unequally weighted moving +average pretty + + align:start position:0% +average pretty + + + align:start position:0% +average pretty +clear I have a question Professor yes + + align:start position:0% +clear I have a question Professor yes + + + align:start position:0% +clear I have a question Professor yes +good these these questions have been + + align:start position:0% +good these these questions have been + + + align:start position:0% +good these these questions have been +wonderful by the way like the last + + align:start position:0% +wonderful by the way like the last + + + align:start position:0% +wonderful by the way like the last +couple of classes uh I think the + + align:start position:0% +couple of classes uh I think the + + + align:start position:0% +couple of classes uh I think the +questions have really uh been right on + + align:start position:0% +questions have really uh been right on + + + align:start position:0% +questions have really uh been right on +Target and it's been a lot of fun so we + + align:start position:0% +Target and it's been a lot of fun so we + + + align:start position:0% +Target and it's been a lot of fun so we +have high expectations for your + + align:start position:0% + + + + align:start position:0% + +question okay so that's a lot of + + align:start position:0% +question okay so that's a lot of + + + align:start position:0% +question okay so that's a lot of +pressure but my question is that for the + + align:start position:0% +pressure but my question is that for the + + + align:start position:0% +pressure but my question is that for the +window size of nine so do do the two uh + + align:start position:0% +window size of nine so do do the two uh + + + align:start position:0% +window size of nine so do do the two uh +Windows next to each other they overlap + + align:start position:0% +Windows next to each other they overlap + + + align:start position:0% +Windows next to each other they overlap +by uh eight data points + + align:start position:0% +by uh eight data points + + + align:start position:0% +by uh eight data points +right okay that's it that's exactly + + align:start position:0% +right okay that's it that's exactly + + + align:start position:0% +right okay that's it that's exactly +right so okay thank + + align:start position:0% +right so okay thank + + + align:start position:0% +right so okay thank +you now one problem with that overlap of + + align:start position:0% +you now one problem with that overlap of + + + align:start position:0% +you now one problem with that overlap of +eight data points is by the time you get + + align:start position:0% +eight data points is by the time you get + + + align:start position:0% +eight data points is by the time you get +to uh you know eight points in the past + + align:start position:0% +to uh you know eight points in the past + + + align:start position:0% +to uh you know eight points in the past +it may be you + + align:start position:0% +it may be you + + + align:start position:0% +it may be you +know that's a long time ago depending on + + align:start position:0% +know that's a long time ago depending on + + + align:start position:0% +know that's a long time ago depending on +on you know how rapidly you're sampling + + align:start position:0% +on you know how rapidly you're sampling + + + align:start position:0% +on you know how rapidly you're sampling +or whatever and compared to the data + + align:start position:0% +or whatever and compared to the data + + + align:start position:0% +or whatever and compared to the data +point that you just took you might think + + align:start position:0% +point that you just took you might think + + + align:start position:0% +point that you just took you might think +that the data point you just took + + align:start position:0% +that the data point you just took + + + align:start position:0% +that the data point you just took +represents the current state of the + + align:start position:0% +represents the current state of the + + + align:start position:0% +represents the current state of the +process a lot better than the 789 time + + align:start position:0% +process a lot better than the 789 time + + + align:start position:0% +process a lot better than the 789 time +points ago and so there is a more + + align:start position:0% +points ago and so there is a more + + + align:start position:0% +points ago and so there is a more +General approach here where you can pick + + align:start position:0% +General approach here where you can pick + + + align:start position:0% +General approach here where you can pick +some waiting for how much you want to + + align:start position:0% +some waiting for how much you want to + + + align:start position:0% +some waiting for how much you want to +fold in data from different points in + + align:start position:0% +fold in data from different points in + + + align:start position:0% +fold in data from different points in +time okay and a classic way way to do + + align:start position:0% +time okay and a classic way way to do + + + align:start position:0% +time okay and a classic way way to do +the waiting is to use an exponentially + + align:start position:0% +the waiting is to use an exponentially + + + align:start position:0% +the waiting is to use an exponentially +weighted moving average where you might + + align:start position:0% +weighted moving average where you might + + + align:start position:0% +weighted moving average where you might +Define The Waiting function these a + + align:start position:0% +Define The Waiting function these a + + + align:start position:0% +Define The Waiting function these a +subis here I guess I've switched + + align:start position:0% +subis here I guess I've switched + + + align:start position:0% +subis here I guess I've switched +notation to a w here um when I'm at the + + align:start position:0% +notation to a w here um when I'm at the + + + align:start position:0% +notation to a w here um when I'm at the +current sample point or the current time + + align:start position:0% +current sample point or the current time + + + align:start position:0% +current sample point or the current time +Point T I might wait points backwards in + + align:start position:0% +Point T I might wait points backwards in + + + align:start position:0% +Point T I might wait points backwards in +time by index I I going from 1 to 9 to a + + align:start position:0% +time by index I I going from 1 to 9 to a + + + align:start position:0% +time by index I I going from 1 to 9 to a +th whatever uh by a function looking + + align:start position:0% +th whatever uh by a function looking + + + align:start position:0% +th whatever uh by a function looking +something like this with some + + align:start position:0% +something like this with some + + + align:start position:0% +something like this with some +r factor this where where R is sort of + + align:start position:0% +r factor this where where R is sort of + + + align:start position:0% +r factor this where where R is sort of +the waiting the waiting Factor so what + + align:start position:0% +the waiting the waiting Factor so what + + + align:start position:0% +the waiting the waiting Factor so what +happens here as I might think of r as + + align:start position:0% +happens here as I might think of r as + + + align:start position:0% +happens here as I might think of r as +being how much I believe my current data + + align:start position:0% +being how much I believe my current data + + + align:start position:0% +being how much I believe my current data +point and it might be I believe my + + align:start position:0% +point and it might be I believe my + + + align:start position:0% +point and it might be I believe my +current data point by + + align:start position:0% +current data point by + + + align:start position:0% +current data point by +90% And then the next data point one + + align:start position:0% +90% And then the next data point one + + + align:start position:0% +90% And then the next data point one +minus r is only 10% so I'm only mixing + + align:start position:0% +minus r is only 10% so I'm only mixing + + + align:start position:0% +minus r is only 10% so I'm only mixing +in 10% of that and then the next data + + align:start position:0% +in 10% of that and then the next data + + + align:start position:0% +in 10% of that and then the next data +point beyond that that it's maybe 0.1 + + align:start position:0% +point beyond that that it's maybe 0.1 + + + align:start position:0% +point beyond that that it's maybe 0.1 +time 0.1 it's only 0.01 so I'm only + + align:start position:0% +time 0.1 it's only 0.01 so I'm only + + + align:start position:0% +time 0.1 it's only 0.01 so I'm only +mixing in 1% of the the previous data + + align:start position:0% +mixing in 1% of the the previous data + + + align:start position:0% +mixing in 1% of the the previous data +point so very rapidly I have this drop + + align:start position:0% +point so very rapidly I have this drop + + + align:start position:0% +point so very rapidly I have this drop +off as a function of uh data points in + + align:start position:0% +off as a function of uh data points in + + + align:start position:0% +off as a function of uh data points in +the + + align:start position:0% +the + + + align:start position:0% +the +past this is my I + + align:start position:0% + + + + align:start position:0% + +index so that so that I much more + + align:start position:0% +index so that so that I much more + + + align:start position:0% +index so that so that I much more +heavily wait recent history and then + + align:start position:0% +heavily wait recent history and then + + + align:start position:0% +heavily wait recent history and then +exponentially Decay uh in into the + + align:start position:0% +exponentially Decay uh in into the + + + align:start position:0% +exponentially Decay uh in into the +past okay but I still have this degree + + align:start position:0% +past okay but I still have this degree + + + align:start position:0% +past okay but I still have this degree +of Freedom how much do I want to I can I + + align:start position:0% +of Freedom how much do I want to I can I + + + align:start position:0% +of Freedom how much do I want to I can I +can pick r i can sort of pick the + + align:start position:0% +can pick r i can sort of pick the + + + align:start position:0% +can pick r i can sort of pick the +relative weighting of of more recent + + align:start position:0% +relative weighting of of more recent + + + align:start position:0% +relative weighting of of more recent +data compared to compared to old + + align:start position:0% +data compared to compared to old + + + align:start position:0% +data compared to compared to old +data now one way of looking at this is + + align:start position:0% +data now one way of looking at this is + + + align:start position:0% +data now one way of looking at this is +actually I have access to all past + + align:start position:0% +actually I have access to all past + + + align:start position:0% +actually I have access to all past +data and I would apply this out to you + + align:start position:0% +data and I would apply this out to you + + + align:start position:0% +data and I would apply this out to you +know 20 data points or 50 or 100 with + + align:start position:0% +know 20 data points or 50 or 100 with + + + align:start position:0% +know 20 data points or 50 or 100 with +the appropriate waiting + + align:start position:0% +the appropriate waiting + + + align:start position:0% +the appropriate waiting +function right and I guess with computer + + align:start position:0% +function right and I guess with computer + + + align:start position:0% +function right and I guess with computer +systems these days it would be no + + align:start position:0% +systems these days it would be no + + + align:start position:0% +systems these days it would be no +problem to actually apply it in that in + + align:start position:0% +problem to actually apply it in that in + + + align:start position:0% +problem to actually apply it in that in +that fashion there's a beautiful thing + + align:start position:0% +that fashion there's a beautiful thing + + + align:start position:0% +that fashion there's a beautiful thing +about the exponentially weighted moving + + align:start position:0% +about the exponentially weighted moving + + + align:start position:0% +about the exponentially weighted moving +average which is I actually don't have + + align:start position:0% +average which is I actually don't have + + + align:start position:0% +average which is I actually don't have +to keep track of all of the raw + + align:start position:0% +to keep track of all of the raw + + + align:start position:0% +to keep track of all of the raw +data there's another way of thinking + + align:start position:0% +data there's another way of thinking + + + align:start position:0% +data there's another way of thinking +about what the ewma this exponential + + align:start position:0% +about what the ewma this exponential + + + align:start position:0% +about what the ewma this exponential +weighted moving average is doing and + + align:start position:0% +weighted moving average is doing and + + + align:start position:0% +weighted moving average is doing and +that's that I have my previous best + + align:start position:0% +that's that I have my previous best + + + align:start position:0% +that's that I have my previous best +estimate of the state of my variable my + + align:start position:0% +estimate of the state of my variable my + + + align:start position:0% +estimate of the state of my variable my +previous best estimate of the mean and + + align:start position:0% +previous best estimate of the mean and + + + align:start position:0% +previous best estimate of the mean and +now I have one new data point and I use + + align:start position:0% +now I have one new data point and I use + + + align:start position:0% +now I have one new data point and I use +that one new data point to update my + + align:start position:0% +that one new data point to update my + + + align:start position:0% +that one new data point to update my +best estimate my best estimate had + + align:start position:0% +best estimate my best estimate had + + + align:start position:0% +best estimate my best estimate had +embedded in it all of the past history + + align:start position:0% +embedded in it all of the past history + + + align:start position:0% +embedded in it all of the past history +so now with the additional new weight I + + align:start position:0% +so now with the additional new weight I + + + align:start position:0% +so now with the additional new weight I +can just do a simple update of my best + + align:start position:0% +can just do a simple update of my best + + + align:start position:0% +can just do a simple update of my best +state estimate and there is essentially + + align:start position:0% +state estimate and there is essentially + + + align:start position:0% +state estimate and there is essentially +a recursive formula that makes this + + align:start position:0% +a recursive formula that makes this + + + align:start position:0% +a recursive formula that makes this +explicit and it's exactly the same thing + + align:start position:0% +explicit and it's exactly the same thing + + + align:start position:0% +explicit and it's exactly the same thing +if you now apply it iteratively out to + + align:start position:0% +if you now apply it iteratively out to + + + align:start position:0% +if you now apply it iteratively out to +all history as actually performing that + + align:start position:0% +all history as actually performing that + + + align:start position:0% +all history as actually performing that +comp computation of applying the weights + + align:start position:0% +comp computation of applying the weights + + + align:start position:0% +comp computation of applying the weights +on all all past data so that is to say + + align:start position:0% +on all all past data so that is to say + + + align:start position:0% +on all all past data so that is to say +let's say a subi is my best estimate of + + align:start position:0% +let's say a subi is my best estimate of + + + align:start position:0% +let's say a subi is my best estimate of +of whatever my statistic is my mean + + align:start position:0% +of whatever my statistic is my mean + + + align:start position:0% +of whatever my statistic is my mean +again I might wait my current data point + + align:start position:0% +again I might wait my current data point + + + align:start position:0% +again I might wait my current data point +my most recent data point say 90% which + + align:start position:0% +my most recent data point say 90% which + + + align:start position:0% +my most recent data point say 90% which +would be you know really rapid update I + + align:start position:0% +would be you know really rapid update I + + + align:start position:0% +would be you know really rapid update I +really believe my most recent data and + + align:start position:0% +really believe my most recent data and + + + align:start position:0% +really believe my most recent data and +then my one minus r applies to my + + align:start position:0% +then my one minus r applies to my + + + align:start position:0% +then my one minus r applies to my +previous + + align:start position:0% + + + + align:start position:0% + +oops to to my previous + + align:start position:0% + + + + align:start position:0% + +estimate right so I'm believing only 10% + + align:start position:0% +estimate right so I'm believing only 10% + + + align:start position:0% +estimate right so I'm believing only 10% +my previous estimate and 90% my new + + align:start position:0% +my previous estimate and 90% my new + + + align:start position:0% +my previous estimate and 90% my new +estimate + + align:start position:0% +estimate + + + align:start position:0% +estimate +okay so it makes it a little bit easier + + align:start position:0% +okay so it makes it a little bit easier + + + align:start position:0% +okay so it makes it a little bit easier +in terms of uh the computation but I + + align:start position:0% +in terms of uh the computation but I + + + align:start position:0% +in terms of uh the computation but I +think it's also conceptually nice in + + align:start position:0% +think it's also conceptually nice in + + + align:start position:0% +think it's also conceptually nice in +terms of what the action here + + align:start position:0% +terms of what the action here + + + align:start position:0% +terms of what the action here +is now one can go through and do a + + align:start position:0% +is now one can go through and do a + + + align:start position:0% +is now one can go through and do a +little bit of the uh the the mathematics + + align:start position:0% +little bit of the uh the the mathematics + + + align:start position:0% +little bit of the uh the the mathematics +it's actually a little easier to do it + + align:start position:0% +it's actually a little easier to do it + + + align:start position:0% +it's actually a little easier to do it +on the full summation version but you + + align:start position:0% +on the full summation version but you + + + align:start position:0% +on the full summation version but you +just do basic uh expectation math on the + + align:start position:0% +just do basic uh expectation math on the + + + align:start position:0% +just do basic uh expectation math on the +variance of an + + align:start position:0% +variance of an + + + align:start position:0% +variance of an +ewma again drawing from a normal normal + + align:start position:0% +ewma again drawing from a normal normal + + + align:start position:0% +ewma again drawing from a normal normal +distribution that is in control and one + + align:start position:0% +distribution that is in control and one + + + align:start position:0% +distribution that is in control and one +can estimate the standard deviation of + + align:start position:0% +can estimate the standard deviation of + + + align:start position:0% +can estimate the standard deviation of +this a + + align:start position:0% +this a + + + align:start position:0% +this a +statistic and it's kind of a little bit + + align:start position:0% +statistic and it's kind of a little bit + + + align:start position:0% +statistic and it's kind of a little bit +messy it's got the underlying process + + align:start position:0% +messy it's got the underlying process + + + align:start position:0% +messy it's got the underlying process +variation in it the fact that you are + + align:start position:0% +variation in it the fact that you are + + + align:start position:0% +variation in it the fact that you are +still um you you can still be doing + + align:start position:0% +still um you you can still be doing + + + align:start position:0% +still um you you can still be doing +sampling for each x sub I that might be + + align:start position:0% +sampling for each x sub I that might be + + + align:start position:0% +sampling for each x sub I that might be +a sample of end data points very often + + align:start position:0% +a sample of end data points very often + + + align:start position:0% +a sample of end data points very often +you might simply be doing it one data + + align:start position:0% +you might simply be doing it one data + + + align:start position:0% +you might simply be doing it one data +point so n very often is just one and + + align:start position:0% +point so n very often is just one and + + + align:start position:0% +point so n very often is just one and +then this formula with r in it including + + align:start position:0% +then this formula with r in it including + + + align:start position:0% +then this formula with r in it including +this one - one - R to the 2T where T is + + align:start position:0% +this one - one - R to the 2T where T is + + + align:start position:0% +this one - one - R to the 2T where T is +how far along you are so it's kind of + + align:start position:0% +how far along you are so it's kind of + + + align:start position:0% +how far along you are so it's kind of +nasty but one thing that's nice is once + + align:start position:0% +nasty but one thing that's nice is once + + + align:start position:0% +nasty but one thing that's nice is once +you started up your control chart and + + align:start position:0% +you started up your control chart and + + + align:start position:0% +you started up your control chart and +you're away from that little artifact + + align:start position:0% +you're away from that little artifact + + + align:start position:0% +you're away from that little artifact +that we saw with the moving average + + align:start position:0% +that we saw with the moving average + + + align:start position:0% +that we saw with the moving average +where the variance limits sort of change + + align:start position:0% +where the variance limits sort of change + + + align:start position:0% +where the variance limits sort of change +once you get far enough away from that + + align:start position:0% +once you get far enough away from that + + + align:start position:0% +once you get far enough away from that +that startup your T is is large and that + + align:start position:0% +that startup your T is is large and that + + + align:start position:0% +that startup your T is is large and that +this whole term just drops + + align:start position:0% +this whole term just drops + + + align:start position:0% +this whole term just drops +out drops out more fast when or more + + align:start position:0% +out drops out more fast when or more + + + align:start position:0% +out drops out more fast when or more +rapidly you know for for uh large values + + align:start position:0% +rapidly you know for for uh large values + + + align:start position:0% +rapidly you know for for uh large values +of R because I'm really waiting more + + align:start position:0% +of R because I'm really waiting more + + + align:start position:0% +of R because I'm really waiting more +towards recent history but even for + + align:start position:0% +towards recent history but even for + + + align:start position:0% +towards recent history but even for +small or modest values of R after you + + align:start position:0% +small or modest values of R after you + + + align:start position:0% +small or modest values of R after you +get out you know 10 20 data points it + + align:start position:0% +get out you know 10 20 data points it + + + align:start position:0% +get out you know 10 20 data points it +typically drops away so now you've got + + align:start position:0% +typically drops away so now you've got + + + align:start position:0% +typically drops away so now you've got +an estimate for large t for the variance + + align:start position:0% +an estimate for large t for the variance + + + align:start position:0% +an estimate for large t for the variance +Sigma a of your statistic and you can + + align:start position:0% +Sigma a of your statistic and you can + + + align:start position:0% +Sigma a of your statistic and you can +simply plot plus minus 3 Sigma or + + align:start position:0% +simply plot plus minus 3 Sigma or + + + align:start position:0% +simply plot plus minus 3 Sigma or +whatever control limits you want + + align:start position:0% +whatever control limits you want + + + align:start position:0% +whatever control limits you want +depending on your false alarm rate + + align:start position:0% +depending on your false alarm rate + + + align:start position:0% +depending on your false alarm rate +Alpha so this is pretty + + align:start position:0% +Alpha so this is pretty + + + align:start position:0% +Alpha so this is pretty +cool uh one quick observation here is + + align:start position:0% +cool uh one quick observation here is + + + align:start position:0% +cool uh one quick observation here is +again we still have a lot of degrees of + + align:start position:0% +again we still have a lot of degrees of + + + align:start position:0% +again we still have a lot of degrees of +flexibility around the choice of R and + + align:start position:0% +flexibility around the choice of R and + + + align:start position:0% +flexibility around the choice of R and +if we look at this formula + + align:start position:0% +if we look at this formula + + + align:start position:0% +if we look at this formula +here and the effect of R i' sort of + + align:start position:0% +here and the effect of R i' sort of + + + align:start position:0% +here and the effect of R i' sort of +plotted uh this this out in this next + + align:start position:0% +plotted uh this this out in this next + + + align:start position:0% +plotted uh this this out in this next +chart this effect of r on the sigma + + align:start position:0% +chart this effect of r on the sigma + + + align:start position:0% +chart this effect of r on the sigma +multiplier oops sorry is this this + + align:start position:0% +multiplier oops sorry is this this + + + align:start position:0% +multiplier oops sorry is this this +Factor right here so in other words as R + + align:start position:0% +Factor right here so in other words as R + + + align:start position:0% +Factor right here so in other words as R +changes how do my control limits move + + align:start position:0% +changes how do my control limits move + + + align:start position:0% +changes how do my control limits move +what is this multiplier of my Sigma over + + align:start position:0% +what is this multiplier of my Sigma over + + + align:start position:0% +what is this multiplier of my Sigma over +root n from from my normal + + align:start position:0% +root n from from my normal + + + align:start position:0% +root n from from my normal +sampling and you can sort of look at it + + align:start position:0% +sampling and you can sort of look at it + + + align:start position:0% +sampling and you can sort of look at it +here and as R gets larger well that gets + + align:start position:0% +here and as R gets larger well that gets + + + align:start position:0% +here and as R gets larger well that gets +larger this gets a as R approaches one + + align:start position:0% +larger this gets a as R approaches one + + + align:start position:0% +larger this gets a as R approaches one +typically you don't ever go above one + + align:start position:0% +typically you don't ever go above one + + + align:start position:0% +typically you don't ever go above one +you can't believe your most recent data + + align:start position:0% +you can't believe your most recent data + + + align:start position:0% +you can't believe your most recent data +point more than 100 percent it's sort of + + align:start position:0% +point more than 100 percent it's sort of + + + align:start position:0% +point more than 100 percent it's sort of +a a ratio U or fraction of the percent + + align:start position:0% +a a ratio U or fraction of the percent + + + align:start position:0% +a a ratio U or fraction of the percent +you can see that as R gets uh + + align:start position:0% +you can see that as R gets uh + + + align:start position:0% +you can see that as R gets uh +larger this uh multiplier starts to + + align:start position:0% +larger this uh multiplier starts to + + + align:start position:0% +larger this uh multiplier starts to +approach uh approach some limit and + + align:start position:0% +approach uh approach some limit and + + + align:start position:0% +approach uh approach some limit and +finally when R is equal to one this + + align:start position:0% +finally when R is equal to one this + + + align:start position:0% +finally when R is equal to one this +multiplier is simply one right in the + + align:start position:0% +multiplier is simply one right in the + + + align:start position:0% +multiplier is simply one right in the +limit when R is equal to one what are we + + align:start position:0% +limit when R is equal to one what are we + + + align:start position:0% +limit when R is equal to one what are we +doing we're doing a 100% up update based + + align:start position:0% +doing we're doing a 100% up update based + + + align:start position:0% +doing we're doing a 100% up update based +on my most recent data point in other + + align:start position:0% +on my most recent data point in other + + + align:start position:0% +on my most recent data point in other +words I'm only looking at my most recent + + align:start position:0% +words I'm only looking at my most recent + + + align:start position:0% +words I'm only looking at my most recent +data point my variance is simply the + + align:start position:0% +data point my variance is simply the + + + align:start position:0% +data point my variance is simply the +process variance coming from sampling + + align:start position:0% +process variance coming from sampling + + + align:start position:0% +process variance coming from sampling +this all reduces to simple Sigma a being + + align:start position:0% +this all reduces to simple Sigma a being + + + align:start position:0% +this all reduces to simple Sigma a being +my sampling variance whatever size + + align:start position:0% +my sampling variance whatever size + + + align:start position:0% +my sampling variance whatever size +sample I was doing within each + + align:start position:0% +sample I was doing within each + + + align:start position:0% +sample I was doing within each +formulation so so in that case I I have + + align:start position:0% +formulation so so in that case I I have + + + align:start position:0% +formulation so so in that case I I have +no uh no factor or no multiplier on that + + align:start position:0% +no uh no factor or no multiplier on that + + + align:start position:0% +no uh no factor or no multiplier on that +Sigma a but for other values of r + + align:start position:0% +Sigma a but for other values of r + + + align:start position:0% +Sigma a but for other values of r +what's happening for smaller values of + + align:start position:0% + + + + align:start position:0% + +R what do we + + align:start position:0% +R what do we + + + align:start position:0% +R what do we +see the sigma a is smaller than the + + align:start position:0% +see the sigma a is smaller than the + + + align:start position:0% +see the sigma a is smaller than the +sigma X over root n we're getting + + align:start position:0% +sigma X over root n we're getting + + + align:start position:0% +sigma X over root n we're getting +reduction in the variance because of + + align:start position:0% +reduction in the variance because of + + + align:start position:0% +reduction in the variance because of +filtering the variance of our estimate + + align:start position:0% +filtering the variance of our estimate + + + align:start position:0% +filtering the variance of our estimate +right so that was the whole idea is I + + align:start position:0% +right so that was the whole idea is I + + + align:start position:0% +right so that was the whole idea is I +can tighten my control limits + + align:start position:0% +can tighten my control limits + + + align:start position:0% +can tighten my control limits +essentially by by the filtering action + + align:start position:0% +essentially by by the filtering action + + + align:start position:0% +essentially by by the filtering action +okay so as I get smaller and smaller RS + + align:start position:0% +okay so as I get smaller and smaller RS + + + align:start position:0% +okay so as I get smaller and smaller RS +I we I do more and more aggressive + + align:start position:0% +I we I do more and more aggressive + + + align:start position:0% +I we I do more and more aggressive +filtering with lots of past data I get + + align:start position:0% +filtering with lots of past data I get + + + align:start position:0% +filtering with lots of past data I get +Tighter and Tighter limits but of course + + align:start position:0% +Tighter and Tighter limits but of course + + + align:start position:0% +Tighter and Tighter limits but of course +I'm also + + align:start position:0% +I'm also + + + align:start position:0% +I'm also +suppressing recent data a little bit a + + align:start position:0% +suppressing recent data a little bit a + + + align:start position:0% +suppressing recent data a little bit a +little bit more heavily so there is this + + align:start position:0% +little bit more heavily so there is this + + + align:start position:0% +little bit more heavily so there is this +so there is this tradeoff let's look at + + align:start position:0% +so there is this tradeoff let's look at + + + align:start position:0% +so there is this tradeoff let's look at +some + + align:start position:0% +some + + + align:start position:0% +some +examples oh well I guess I made these + + align:start position:0% +examples oh well I guess I made these + + + align:start position:0% +examples oh well I guess I made these +points already here again um the + + align:start position:0% +points already here again um the + + + align:start position:0% +points already here again um the +variance of this estimate for the mean + + align:start position:0% +variance of this estimate for the mean + + + align:start position:0% +variance of this estimate for the mean +for the your best guess of the of the + + align:start position:0% +for the your best guess of the of the + + + align:start position:0% +for the your best guess of the of the +mean is smaller uh than than you would + + align:start position:0% +mean is smaller uh than than you would + + + align:start position:0% +mean is smaller uh than than you would +have had with an xar chart because the + + align:start position:0% +have had with an xar chart because the + + + align:start position:0% +have had with an xar chart because the +xar chart remember for a sample size of + + align:start position:0% +xar chart remember for a sample size of + + + align:start position:0% +xar chart remember for a sample size of +n is simply is simply that so we do get + + align:start position:0% +n is simply is simply that so we do get + + + align:start position:0% +n is simply is simply that so we do get +this suppression and it is very nice + + align:start position:0% +this suppression and it is very nice + + + align:start position:0% +this suppression and it is very nice +that it also in the limit works out for + + align:start position:0% +that it also in the limit works out for + + + align:start position:0% +that it also in the limit works out for +both the sample size of one case these + + align:start position:0% +both the sample size of one case these + + + align:start position:0% +both the sample size of one case these +formulas still hold and also the full + + align:start position:0% +formulas still hold and also the full + + + align:start position:0% +formulas still hold and also the full +update case or the R equals 1 where we + + align:start position:0% +update case or the R equals 1 where we + + + align:start position:0% +update case or the R equals 1 where we +have completely unfiltered data you're + + align:start position:0% +have completely unfiltered data you're + + + align:start position:0% +have completely unfiltered data you're +just plotting your your pure run data uh + + align:start position:0% +just plotting your your pure run data uh + + + align:start position:0% +just plotting your your pure run data uh +on your chart so if what happens if I + + align:start position:0% +on your chart so if what happens if I + + + align:start position:0% +on your chart so if what happens if I +use much smaller RS like + + align:start position:0% +use much smaller RS like + + + align:start position:0% +use much smaller RS like +0.1 right I got much tighter control + + align:start position:0% +0.1 right I got much tighter control + + + align:start position:0% +0.1 right I got much tighter control +limits but I've got long delays + + align:start position:0% +limits but I've got long delays + + + align:start position:0% +limits but I've got long delays +potentially then in in detecting I've + + align:start position:0% +potentially then in in detecting I've + + + align:start position:0% +potentially then in in detecting I've +got a lot of noise supression but again + + align:start position:0% +got a lot of noise supression but again + + + align:start position:0% +got a lot of noise supression but again +I get back to Long delays in detecting + + align:start position:0% +I get back to Long delays in detecting + + + align:start position:0% +I get back to Long delays in detecting +or responding to a true shift in the + + align:start position:0% +or responding to a true shift in the + + + align:start position:0% +or responding to a true shift in the +mean so I want to look at a few examples + + align:start position:0% +mean so I want to look at a few examples + + + align:start position:0% +mean so I want to look at a few examples +here uh to give you a feel of the + + align:start position:0% +here uh to give you a feel of the + + + align:start position:0% +here uh to give you a feel of the +tradeoff between different RS for for + + align:start position:0% +tradeoff between different RS for for + + + align:start position:0% +tradeoff between different RS for for +some + + align:start position:0% +some + + + align:start position:0% +some +data and compare it as well to a typical + + align:start position:0% +data and compare it as well to a typical + + + align:start position:0% +data and compare it as well to a typical +xar + + align:start position:0% +xar + + + align:start position:0% +xar +chart okay so here's a uh set of data + + align:start position:0% +chart okay so here's a uh set of data + + + align:start position:0% +chart okay so here's a uh set of data +and we're seeing a comparison here + + align:start position:0% +and we're seeing a comparison here + + + align:start position:0% +and we're seeing a comparison here +between the xbar + + align:start position:0% +between the xbar + + + align:start position:0% +between the xbar +chart um so you can see let's see here + + align:start position:0% +chart um so you can see let's see here + + + align:start position:0% +chart um so you can see let's see here +are the up + + align:start position:0% +are the up + + + align:start position:0% +are the up +xbar uh upper and lower control limits + + align:start position:0% +xbar uh upper and lower control limits + + + align:start position:0% +xbar uh upper and lower control limits +and sure enough after 15 + + align:start position:0% +and sure enough after 15 + + + align:start position:0% +and sure enough after 15 +runs where at uh I don't know about run + + align:start position:0% +runs where at uh I don't know about run + + + align:start position:0% +runs where at uh I don't know about run +90 we we make this shift in the process + + align:start position:0% +90 we we make this shift in the process + + + align:start position:0% +90 we we make this shift in the process +so we shift the whole process by a uh a + + align:start position:0% +so we shift the whole process by a uh a + + + align:start position:0% +so we shift the whole process by a uh a +half a standard deviation of the + + align:start position:0% +half a standard deviation of the + + + align:start position:0% +half a standard deviation of the +underlying process and sure enough by + + align:start position:0% +underlying process and sure enough by + + + align:start position:0% +underlying process and sure enough by +about I don't know run 140 we finally + + align:start position:0% +about I don't know run 140 we finally + + + align:start position:0% +about I don't know run 140 we finally +got a data point in the tail of the mean + + align:start position:0% +got a data point in the tail of the mean + + + align:start position:0% +got a data point in the tail of the mean +distribution the regular xar that fell + + align:start position:0% +distribution the regular xar that fell + + + align:start position:0% +distribution the regular xar that fell +out and we could actually calculate the + + align:start position:0% +out and we could actually calculate the + + + align:start position:0% +out and we could actually calculate the +average run length to detect a mean + + align:start position:0% +average run length to detect a mean + + + align:start position:0% +average run length to detect a mean +shift of 0.5 using some of the + + align:start position:0% +shift of 0.5 using some of the + + + align:start position:0% +shift of 0.5 using some of the +techniques we talked about last + + align:start position:0% +techniques we talked about last + + + align:start position:0% +techniques we talked about last +time and we might not be happy with that + + align:start position:0% +time and we might not be happy with that + + + align:start position:0% +time and we might not be happy with that +very long ARL and the question is would + + align:start position:0% +very long ARL and the question is would + + + align:start position:0% +very long ARL and the question is would +an ewma chart help us with this and this + + align:start position:0% +an ewma chart help us with this and this + + + align:start position:0% +an ewma chart help us with this and this +is an example where we're using about a + + align:start position:0% +is an example where we're using about a + + + align:start position:0% +is an example where we're using about a +30% update based on each new new data + + align:start position:0% +30% update based on each new new data + + + align:start position:0% +30% update based on each new new data +point and plotted in purple with the + + align:start position:0% +point and plotted in purple with the + + + align:start position:0% +point and plotted in purple with the +blue and the yellow uh are the upper and + + align:start position:0% +blue and the yellow uh are the upper and + + + align:start position:0% +blue and the yellow uh are the upper and +lower control limits for the + + align:start position:0% +lower control limits for the + + + align:start position:0% +lower control limits for the +ewma and what you see is the effect + + align:start position:0% +ewma and what you see is the effect + + + align:start position:0% +ewma and what you see is the effect +of averaging now I always + + align:start position:0% +of averaging now I always + + + align:start position:0% +of averaging now I always +find it easiest for me to conceptualize + + align:start position:0% +find it easiest for me to conceptualize + + + align:start position:0% +find it easiest for me to conceptualize +the action of an ewma chart as just kind + + align:start position:0% +the action of an ewma chart as just kind + + + align:start position:0% +the action of an ewma chart as just kind +of like a moving average the equally + + align:start position:0% +of like a moving average the equally + + + align:start position:0% +of like a moving average the equally +weighted moving average but weighted a + + align:start position:0% +weighted moving average but weighted a + + + align:start position:0% +weighted moving average but weighted a +little bit more towards recent history + + align:start position:0% +little bit more towards recent history + + + align:start position:0% +little bit more towards recent history +but the whole idea is I get that + + align:start position:0% +but the whole idea is I get that + + + align:start position:0% +but the whole idea is I get that +aggregation from a any kind of a moving + + align:start position:0% +aggregation from a any kind of a moving + + + align:start position:0% +aggregation from a any kind of a moving +average so that right after this shift + + align:start position:0% +average so that right after this shift + + + align:start position:0% +average so that right after this shift +right here now when I take into account + + align:start position:0% +right here now when I take into account + + + align:start position:0% +right here now when I take into account +with an R of3 you know I'm taking into + + align:start position:0% +with an R of3 you know I'm taking into + + + align:start position:0% +with an R of3 you know I'm taking into +account you know three four five data + + align:start position:0% +account you know three four five data + + + align:start position:0% +account you know three four five data +points I've got kind of an effective + + align:start position:0% +points I've got kind of an effective + + + align:start position:0% +points I've got kind of an effective +window weighted about 30% towards my + + align:start position:0% +window weighted about 30% towards my + + + align:start position:0% +window weighted about 30% towards my +most recent but including some past + + align:start position:0% +most recent but including some past + + + align:start position:0% +most recent but including some past +history that all of the plus Delta new + + align:start position:0% +history that all of the plus Delta new + + + align:start position:0% +history that all of the plus Delta new +data points all average and then my my + + align:start position:0% +data points all average and then my my + + + align:start position:0% +data points all average and then my my +normal process variation you know just + + align:start position:0% +normal process variation you know just + + + align:start position:0% +normal process variation you know just +cancels out each other and so it's + + align:start position:0% +cancels out each other and so it's + + + align:start position:0% +cancels out each other and so it's +very intuitive I think that this ewma is + + align:start position:0% +very intuitive I think that this ewma is + + + align:start position:0% +very intuitive I think that this ewma is +going to aggregate or respond to or + + align:start position:0% +going to aggregate or respond to or + + + align:start position:0% +going to aggregate or respond to or +sense the Delta shift in the mean more + + align:start position:0% +sense the Delta shift in the mean more + + + align:start position:0% +sense the Delta shift in the mean more +than an individual + + align:start position:0% +than an individual + + + align:start position:0% +than an individual +um uh xar chart would have been doing so + + align:start position:0% +um uh xar chart would have been doing so + + + align:start position:0% +um uh xar chart would have been doing so +that it responds in this case I don't + + align:start position:0% +that it responds in this case I don't + + + align:start position:0% +that it responds in this case I don't +know after about I don't know 15 or 20 + + align:start position:0% +know after about I don't know 15 or 20 + + + align:start position:0% +know after about I don't know 15 or 20 +data points you you can start to see + + align:start position:0% +data points you you can start to see + + + align:start position:0% +data points you you can start to see +excursions beyond the the control + + align:start position:0% +excursions beyond the the control + + + align:start position:0% +excursions beyond the the control +limits question um at the beginning of + + align:start position:0% +limits question um at the beginning of + + + align:start position:0% +limits question um at the beginning of +the shark why are the control limits now + + align:start position:0% +the shark why are the control limits now + + + align:start position:0% +the shark why are the control limits now +spreading out and last time they + + align:start position:0% + + + + align:start position:0% + +were I think we had another sh + + align:start position:0% +were I think we had another sh + + + align:start position:0% +were I think we had another sh +wait why are the control limits I think + + align:start position:0% +wait why are the control limits I think + + + align:start position:0% +wait why are the control limits I think +you can go back to this formula and see + + align:start position:0% +you can go back to this formula and see + + + align:start position:0% +you can go back to this formula and see +if that + + align:start position:0% +if that + + + align:start position:0% +if that +works I think essentially what you've + + align:start position:0% + + + + align:start position:0% + +got I bet if you look at the effect of + + align:start position:0% +got I bet if you look at the effect of + + + align:start position:0% +got I bet if you look at the effect of +the T + + align:start position:0% +the T + + + align:start position:0% +the T +action + + align:start position:0% + + + + align:start position:0% + +uh formulaically or analytically I think + + align:start position:0% +uh formulaically or analytically I think + + + align:start position:0% +uh formulaically or analytically I think +that as T starts out being very small + + align:start position:0% +that as T starts out being very small + + + align:start position:0% +that as T starts out being very small +so if T is very + + align:start position:0% + + + + align:start position:0% + +small see so if T is zero this is + + align:start position:0% +small see so if T is zero this is + + + align:start position:0% +small see so if T is zero this is +essentially one if + + align:start position:0% +essentially one if + + + align:start position:0% +essentially one if +T is large well let's say t was one and + + align:start position:0% +T is large well let's say t was one and + + + align:start position:0% +T is large well let's say t was one and +R was3 i' got 7 so I've got a smaller + + align:start position:0% +R was3 i' got 7 so I've got a smaller + + + align:start position:0% +R was3 i' got 7 so I've got a smaller +I've got a reduction so I think for + + align:start position:0% +I've got a reduction so I think for + + + align:start position:0% +I've got a reduction so I think for +small + + align:start position:0% +small + + + align:start position:0% +small +T I've only got a limited amount of data + + align:start position:0% +T I've only got a limited amount of data + + + align:start position:0% +T I've only got a limited amount of data +and so I I'm not I don't have the long + + align:start position:0% +and so I I'm not I don't have the long + + + align:start position:0% +and so I I'm not I don't have the long +tail in the ewma so I think I'm I've + + align:start position:0% +tail in the ewma so I think I'm I've + + + align:start position:0% +tail in the ewma so I think I'm I've +only got a small amount of data with a + + align:start position:0% +only got a small amount of data with a + + + align:start position:0% +only got a small amount of data with a +larger weight and my control limits I + + align:start position:0% +larger weight and my control limits I + + + align:start position:0% +larger weight and my control limits I +think are smaller but then as T gets + + align:start position:0% +think are smaller but then as T gets + + + align:start position:0% +think are smaller but then as T gets +larger I've got a little bit + + align:start position:0% +larger I've got a little bit + + + align:start position:0% +larger I've got a little bit +more more data until T so I think if I + + align:start position:0% +more more data until T so I think if I + + + align:start position:0% +more more data until T so I think if I +were to plot this one - one minus r to + + align:start position:0% +were to plot this one - one minus r to + + + align:start position:0% +were to plot this one - one minus r to +the 2T kind of has a funky + + align:start position:0% +the 2T kind of has a funky + + + align:start position:0% +the 2T kind of has a funky +shape that that that that dies + + align:start position:0% +shape that that that that dies + + + align:start position:0% +shape that that that that dies +out but I wouldn't worry too much about + + align:start position:0% +out but I wouldn't worry too much about + + + align:start position:0% +out but I wouldn't worry too much about +the startup times I mean there're sort + + align:start position:0% +the startup times I mean there're sort + + + align:start position:0% +the startup times I mean there're sort +of artifacts when you start up a control + + align:start position:0% +of artifacts when you start up a control + + + align:start position:0% +of artifacts when you start up a control +chart but once you just start a control + + align:start position:0% +chart but once you just start a control + + + align:start position:0% +chart but once you just start a control +chart anyway you're you're still feeling + + align:start position:0% +chart anyway you're you're still feeling + + + align:start position:0% +chart anyway you're you're still feeling +out the process so I wouldn't I wouldn't + + align:start position:0% +out the process so I wouldn't I wouldn't + + + align:start position:0% +out the process so I wouldn't I wouldn't +worry too much about about the the + + align:start position:0% +worry too much about about the the + + + align:start position:0% +worry too much about about the the +startup times on these + + align:start position:0% + + + + align:start position:0% + +yeah how do you decide + + align:start position:0% + + + + align:start position:0% + +between yeah so so the question so if + + align:start position:0% +between yeah so so the question so if + + + align:start position:0% +between yeah so so the question so if +you didn't hear that uh in Singapore was + + align:start position:0% +you didn't hear that uh in Singapore was + + + align:start position:0% +you didn't hear that uh in Singapore was +when would you use an ewma or what are + + align:start position:0% +when would you use an ewma or what are + + + align:start position:0% +when would you use an ewma or what are +the factors in using an ew from an xar + + align:start position:0% +the factors in using an ew from an xar + + + align:start position:0% +the factors in using an ew from an xar +chart + + align:start position:0% +chart + + + align:start position:0% +chart +and um I think if you've got a lot of a + + align:start position:0% +and um I think if you've got a lot of a + + + align:start position:0% +and um I think if you've got a lot of a +lot of noise and you're + + align:start position:0% +lot of noise and you're + + + align:start position:0% +lot of noise and you're +really worried about detecting rapidly a + + align:start position:0% +really worried about detecting rapidly a + + + align:start position:0% +really worried about detecting rapidly a +shift in the process an ewma or and + + align:start position:0% +shift in the process an ewma or and + + + align:start position:0% +shift in the process an ewma or and +we'll see the in a minute has + + align:start position:0% +we'll see the in a minute has + + + align:start position:0% +we'll see the in a minute has +improved sensitivity to Rapid detection + + align:start position:0% +improved sensitivity to Rapid detection + + + align:start position:0% +improved sensitivity to Rapid detection +of the shift but it comes at one really + + align:start position:0% +of the shift but it comes at one really + + + align:start position:0% +of the shift but it comes at one really +important cost which is a loss in + + align:start position:0% +important cost which is a loss in + + + align:start position:0% +important cost which is a loss in +transparency in what's going on + + align:start position:0% +transparency in what's going on + + + align:start position:0% +transparency in what's going on +um the xar I think conceptually is a lot + + align:start position:0% +um the xar I think conceptually is a lot + + + align:start position:0% +um the xar I think conceptually is a lot +easier to understand have everybody on + + align:start position:0% +easier to understand have everybody on + + + align:start position:0% +easier to understand have everybody on +the line understand what it is the data + + align:start position:0% +the line understand what it is the data + + + align:start position:0% +the line understand what it is the data +if you also explode out and show the + + align:start position:0% +if you also explode out and show the + + + align:start position:0% +if you also explode out and show the +full data the xar and the and the the S + + align:start position:0% +full data the xar and the and the the S + + + align:start position:0% +full data the xar and the and the the S +gives you a good feel directly to the + + align:start position:0% +gives you a good feel directly to the + + + align:start position:0% +gives you a good feel directly to the +statistics of the process here you look + + align:start position:0% +statistics of the process here you look + + + align:start position:0% +statistics of the process here you look +at this and you lose touch I think a + + align:start position:0% +at this and you lose touch I think a + + + align:start position:0% +at this and you lose touch I think a +little bit with with the statistics of + + align:start position:0% +little bit with with the statistics of + + + align:start position:0% +little bit with with the statistics of +of uh uh and the Rel relationship to + + align:start position:0% +of uh uh and the Rel relationship to + + + align:start position:0% +of uh uh and the Rel relationship to +your raw data it's a little harder to + + align:start position:0% +your raw data it's a little harder to + + + align:start position:0% +your raw data it's a little harder to +get your mind around but if you're I um + + align:start position:0% +get your mind around but if you're I um + + + align:start position:0% +get your mind around but if you're I um +I + + align:start position:0% +I + + + align:start position:0% +I +find well I don't know 101 15 years ago + + align:start position:0% +find well I don't know 101 15 years ago + + + align:start position:0% +find well I don't know 101 15 years ago +I fell in love with the ewma uh chart + + align:start position:0% +I fell in love with the ewma uh chart + + + align:start position:0% +I fell in love with the ewma uh chart +and and approach not only for charting + + align:start position:0% +and and approach not only for charting + + + align:start position:0% +and and approach not only for charting +but also for doing Simple runby Run + + align:start position:0% +but also for doing Simple runby Run + + + align:start position:0% +but also for doing Simple runby Run +control and so I kind of like it but I + + align:start position:0% +control and so I kind of like it but I + + + align:start position:0% +control and so I kind of like it but I +can empathize with uh it being a little + + align:start position:0% +can empathize with uh it being a little + + + align:start position:0% +can empathize with uh it being a little +bit harder to explain and maintain on on + + align:start position:0% +bit harder to explain and maintain on on + + + align:start position:0% +bit harder to explain and maintain on on +the line + + align:start position:0% +the line + + + align:start position:0% +the line +um it's also got a little bit more + + align:start position:0% +um it's also got a little bit more + + + align:start position:0% +um it's also got a little bit more +calculation so you know if back in the + + align:start position:0% +calculation so you know if back in the + + + align:start position:0% +calculation so you know if back in the +days + + align:start position:0% +days + + + align:start position:0% +days +of and it's still true in some of the + + align:start position:0% +of and it's still true in some of the + + + align:start position:0% +of and it's still true in some of the +manufacturing lines I know when we went + + align:start position:0% +manufacturing lines I know when we went + + + align:start position:0% +manufacturing lines I know when we went +on the tour and some of the plants uh + + align:start position:0% +on the tour and some of the plants uh + + + align:start position:0% +on the tour and some of the plants uh +very very you know up-to-date plants in + + align:start position:0% +very very you know up-to-date plants in + + + align:start position:0% +very very you know up-to-date plants in +in in uh Singapore and other places + + align:start position:0% +in in uh Singapore and other places + + + align:start position:0% +in in uh Singapore and other places +around the world people are still often + + align:start position:0% +around the world people are still often + + + align:start position:0% +around the world people are still often +taking measurements by hand and doing + + align:start position:0% +taking measurements by hand and doing + + + align:start position:0% +taking measurements by hand and doing +the hand calculation and writing it on a + + align:start position:0% +the hand calculation and writing it on a + + + align:start position:0% +the hand calculation and writing it on a +chart this has an extra step you got to + + align:start position:0% +chart this has an extra step you got to + + + align:start position:0% +chart this has an extra step you got to +do an extra average you know the so + + align:start position:0% +do an extra average you know the so + + + align:start position:0% +do an extra average you know the so +so in modern day when almost all the uh + + align:start position:0% +so in modern day when almost all the uh + + + align:start position:0% +so in modern day when almost all the uh +calculations are are are automated the + + align:start position:0% +calculations are are are automated the + + + align:start position:0% +calculations are are are automated the +data collection is automated I think + + align:start position:0% +data collection is automated I think + + + align:start position:0% +data collection is automated I think +there's even more reason to go with an + + align:start position:0% +there's even more reason to go with an + + + align:start position:0% +there's even more reason to go with an +ewma so the thing I like about the best + + align:start position:0% +ewma so the thing I like about the best + + + align:start position:0% +ewma so the thing I like about the best +about the + + align:start position:0% +about the + + + align:start position:0% +about the +ewma is I think of it as giving me my + + align:start position:0% +ewma is I think of it as giving me my + + + align:start position:0% +ewma is I think of it as giving me my +best current estimate based not only on + + align:start position:0% +best current estimate based not only on + + + align:start position:0% +best current estimate based not only on +on just my last data point but a little + + align:start position:0% +on just my last data point but a little + + + align:start position:0% +on just my last data point but a little +bit of filtering including past history + + align:start position:0% +bit of filtering including past history + + + align:start position:0% +bit of filtering including past history +is giving my my best educated state of + + align:start position:0% +is giving my my best educated state of + + + align:start position:0% +is giving my my best educated state of +the current + + align:start position:0% +the current + + + align:start position:0% +the current +process and why I liked that for then + + align:start position:0% +process and why I liked that for then + + + align:start position:0% +process and why I liked that for then +runby run control is based on my current + + align:start position:0% +runby run control is based on my current + + + align:start position:0% +runby run control is based on my current +model my updated on a recursive basis + + align:start position:0% +model my updated on a recursive basis + + + align:start position:0% +model my updated on a recursive basis +updated model of the current state of + + align:start position:0% +updated model of the current state of + + + align:start position:0% +updated model of the current state of +the process I can make a decision so + + align:start position:0% +the process I can make a decision so + + + align:start position:0% +the process I can make a decision so +here the decision in SPC is is the + + align:start position:0% +here the decision in SPC is is the + + + align:start position:0% +here the decision in SPC is is the +process in control or not but if you + + align:start position:0% +process in control or not but if you + + + align:start position:0% +process in control or not but if you +think of this being not just the ewma + + align:start position:0% +think of this being not just the ewma + + + align:start position:0% +think of this being not just the ewma +not giving you more information it's not + + align:start position:0% +not giving you more information it's not + + + align:start position:0% +not giving you more information it's not +just giving you am I in control or not + + align:start position:0% +just giving you am I in control or not + + + align:start position:0% +just giving you am I in control or not +given the random spread but if you + + align:start position:0% +given the random spread but if you + + + align:start position:0% +given the random spread but if you +interpret this little purple dat data + + align:start position:0% +interpret this little purple dat data + + + align:start position:0% +interpret this little purple dat data +point here + + align:start position:0% +point here + + + align:start position:0% +point here +as my best estimate of where the mean in + + align:start position:0% +as my best estimate of where the mean in + + + align:start position:0% +as my best estimate of where the mean in +the recent past has been if there is a + + align:start position:0% +the recent past has been if there is a + + + align:start position:0% +the recent past has been if there is a +little bit of drift or or movement maybe + + align:start position:0% +little bit of drift or or movement maybe + + + align:start position:0% +little bit of drift or or movement maybe +I do active control and not pure SPC + + align:start position:0% +I do active control and not pure SPC + + + align:start position:0% +I do active control and not pure SPC +control I'm not making any longer just + + align:start position:0% +control I'm not making any longer just + + + align:start position:0% +control I'm not making any longer just +the decision nothing has changed I'm + + align:start position:0% +the decision nothing has changed I'm + + + align:start position:0% +the decision nothing has changed I'm +saying there are small changes and maybe + + align:start position:0% +saying there are small changes and maybe + + + align:start position:0% +saying there are small changes and maybe +I want to go and make a small + + align:start position:0% +I want to go and make a small + + + align:start position:0% +I want to go and make a small +modification or an adjustment on the + + align:start position:0% +modification or an adjustment on the + + + align:start position:0% +modification or an adjustment on the +equipment now if you are in true + + align:start position:0% +equipment now if you are in true + + + align:start position:0% +equipment now if you are in true +statistical process control that would + + align:start position:0% +statistical process control that would + + + align:start position:0% +statistical process control that would +be the wrong thing to do you'd be over + + align:start position:0% +be the wrong thing to do you'd be over + + + align:start position:0% +be the wrong thing to do you'd be over +adjusting and we'll talk about that + + align:start position:0% +adjusting and we'll talk about that + + + align:start position:0% +adjusting and we'll talk about that +later but that's another thing I like + + align:start position:0% +later but that's another thing I like + + + align:start position:0% +later but that's another thing I like +about the ewma is very often there is a + + align:start position:0% +about the ewma is very often there is a + + + align:start position:0% +about the ewma is very often there is a +little bit of time correlation in the + + align:start position:0% +little bit of time correlation in the + + + align:start position:0% +little bit of time correlation in the +process and the ewma is tracking those + + align:start position:0% +process and the ewma is tracking those + + + align:start position:0% +process and the ewma is tracking those +small + + align:start position:0% +small + + + align:start position:0% +small +changes uh and filtering out some of the + + align:start position:0% +changes uh and filtering out some of the + + + align:start position:0% +changes uh and filtering out some of the +noise it's a good question uh I'll take + + align:start position:0% +noise it's a good question uh I'll take + + + align:start position:0% +noise it's a good question uh I'll take +a question there was somebody had a + + align:start position:0% +a question there was somebody had a + + + align:start position:0% +a question there was somebody had a +question in + + align:start position:0% +question in + + + align:start position:0% +question in +Singapore uh yes so uh I wonder smaller + + align:start position:0% +Singapore uh yes so uh I wonder smaller + + + align:start position:0% +Singapore uh yes so uh I wonder smaller +R will lead to the narrow control limit + + align:start position:0% +R will lead to the narrow control limit + + + align:start position:0% +R will lead to the narrow control limit +right that's right so the narrow control + + align:start position:0% +right that's right so the narrow control + + + align:start position:0% +right that's right so the narrow control +limit you will have a uh smaller + + align:start position:0% + + + + align:start position:0% + +beta + + align:start position:0% +beta + + + align:start position:0% +beta +uh so a smaller beta would be less + + align:start position:0% +uh so a smaller beta would be less + + + align:start position:0% +uh so a smaller beta would be less +chance smaller beta yes yeah t to error + + align:start position:0% +chance smaller beta yes yeah t to error + + + align:start position:0% +chance smaller beta yes yeah t to error +right but its power is uh then larger so + + align:start position:0% +right but its power is uh then larger so + + + align:start position:0% +right but its power is uh then larger so +the chance of detecting a true outof + + align:start position:0% +the chance of detecting a true outof + + + align:start position:0% +the chance of detecting a true outof +control Point + + align:start position:0% +control Point + + + align:start position:0% +control Point +increases but yeah so but there's a a + + align:start position:0% +increases but yeah so but there's a a + + + align:start position:0% +increases but yeah so but there's a a +very important additional factor which + + align:start position:0% +very important additional factor which + + + align:start position:0% +very important additional factor which +is there's additional time lag so I'm + + align:start position:0% +is there's additional time lag so I'm + + + align:start position:0% +is there's additional time lag so I'm +going to show a couple of examples + + align:start position:0% +going to show a couple of examples + + + align:start position:0% +going to show a couple of examples +because you can see uh in other examples + + align:start position:0% +because you can see uh in other examples + + + align:start position:0% +because you can see uh in other examples +the effect of the filtering and the time + + align:start position:0% +the effect of the filtering and the time + + + align:start position:0% +the effect of the filtering and the time +response that it takes to detect can go + + align:start position:0% +response that it takes to detect can go + + + align:start position:0% +response that it takes to detect can go +up + + align:start position:0% + + + + align:start position:0% + +okay so another question here I was just + + align:start position:0% +okay so another question here I was just + + + align:start position:0% +okay so another question here I was just +curious what sample size were you using + + align:start position:0% +curious what sample size were you using + + + align:start position:0% +curious what sample size were you using +for the xar I don't know I I'm not sure + + align:start position:0% +for the xar I don't know I I'm not sure + + + align:start position:0% +for the xar I don't know I I'm not sure +what was used in the in the in the uh as + + align:start position:0% +what was used in the in the in the uh as + + + align:start position:0% +what was used in the in the in the uh as +a sample size I think you're just seeing + + align:start position:0% +a sample size I think you're just seeing + + + align:start position:0% +a sample size I think you're just seeing +the plot of the sample so the sample + + align:start position:0% +the plot of the sample so the sample + + + align:start position:0% +the plot of the sample so the sample +size is actually the same in both + + align:start position:0% +size is actually the same in both + + + align:start position:0% +size is actually the same in both +cases um but + + align:start position:0% +cases um but + + + align:start position:0% +cases um but +uh but I I don't know what was what was + + align:start position:0% +uh but I I don't know what was what was + + + align:start position:0% +uh but I I don't know what was what was +being + + align:start position:0% +being + + + align:start position:0% +being +used in some sense it doesn't actually + + align:start position:0% +used in some sense it doesn't actually + + + align:start position:0% +used in some sense it doesn't actually +matter too much the ewma is looking is + + align:start position:0% +matter too much the ewma is looking is + + + align:start position:0% +matter too much the ewma is looking is +an ewma over sample so I might still be + + align:start position:0% +an ewma over sample so I might still be + + + align:start position:0% +an ewma over sample so I might still be +forming I might have a thousand Parts an + + align:start position:0% +forming I might have a thousand Parts an + + + align:start position:0% +forming I might have a thousand Parts an +hour and every 15 minutes I might do a + + align:start position:0% +hour and every 15 minutes I might do a + + + align:start position:0% +hour and every 15 minutes I might do a +sample size of + + align:start position:0% +sample size of + + + align:start position:0% +sample size of +10 so I'm only getting sample size 10 + + align:start position:0% +10 so I'm only getting sample size 10 + + + align:start position:0% +10 so I'm only getting sample size 10 +lots more and what's being plotted here + + align:start position:0% +lots more and what's being plotted here + + + align:start position:0% +lots more and what's being plotted here +in some sense is the + + align:start position:0% +in some sense is the + + + align:start position:0% +in some sense is the +sample so I have an xar where I might + + align:start position:0% +sample so I have an xar where I might + + + align:start position:0% +sample so I have an xar where I might +plot those samples here what I'm doing + + align:start position:0% +plot those samples here what I'm doing + + + align:start position:0% +plot those samples here what I'm doing +the ewma has enough it has the + + align:start position:0% +the ewma has enough it has the + + + align:start position:0% +the ewma has enough it has the +flexibility to extend to n equals 1 + + align:start position:0% +flexibility to extend to n equals 1 + + + align:start position:0% +flexibility to extend to n equals 1 +sampling if that's what I'm doing but + + align:start position:0% +sampling if that's what I'm doing but + + + align:start position:0% +sampling if that's what I'm doing but +but in some sense it could also be used + + align:start position:0% +but in some sense it could also be used + + + align:start position:0% +but in some sense it could also be used +where instead of each of those nals 10 + + align:start position:0% +where instead of each of those nals 10 + + + align:start position:0% +where instead of each of those nals 10 +samples was the only data I looked at + + align:start position:0% +samples was the only data I looked at + + + align:start position:0% +samples was the only data I looked at +each one of those is my T point in T and + + align:start position:0% +each one of those is my T point in T and + + + align:start position:0% +each one of those is my T point in T and +my previous sample of size 10 is T minus + + align:start position:0% +my previous sample of size 10 is T minus + + + align:start position:0% +my previous sample of size 10 is T minus +one my previous one but so so in some + + align:start position:0% +one my previous one but so so in some + + + align:start position:0% +one my previous one but so so in some +sense it's doing + + align:start position:0% +sense it's doing + + + align:start position:0% +sense it's doing +the whole sample by sample + + align:start position:0% +the whole sample by sample + + + align:start position:0% +the whole sample by sample +comparison so my point here was both the + + align:start position:0% +comparison so my point here was both the + + + align:start position:0% +comparison so my point here was both the +ewma and and the xar are using in this + + align:start position:0% +ewma and and the xar are using in this + + + align:start position:0% +ewma and and the xar are using in this +derivation the same sample size I'm not + + align:start position:0% +derivation the same sample size I'm not + + + align:start position:0% +derivation the same sample size I'm not +differentiating in that all I'm doing in + + align:start position:0% +differentiating in that all I'm doing in + + + align:start position:0% +differentiating in that all I'm doing in +this case really with the ewma is using + + align:start position:0% +this case really with the ewma is using + + + align:start position:0% +this case really with the ewma is using +multiple samples back in time and the + + align:start position:0% +multiple samples back in time and the + + + align:start position:0% +multiple samples back in time and the +xar only uses + + align:start position:0% +xar only uses + + + align:start position:0% +xar only uses +one so so so in fact + + align:start position:0% +one so so so in fact + + + align:start position:0% +one so so so in fact +if I go to R equals 1 the two converge + + align:start position:0% +if I go to R equals 1 the two converge + + + align:start position:0% +if I go to R equals 1 the two converge +they are the same the R equals 1 ewma is + + align:start position:0% +they are the same the R equals 1 ewma is + + + align:start position:0% +they are the same the R equals 1 ewma is +exactly the same as the xar but the + + align:start position:0% +exactly the same as the xar but the + + + align:start position:0% +exactly the same as the xar but the +larger my sample size is the less of a + + align:start position:0% +larger my sample size is the less of a + + + align:start position:0% +larger my sample size is the less of a +spread I get between my two they would + + align:start position:0% +spread I get between my two they would + + + align:start position:0% +spread I get between my two they would +all they would they would they would + + align:start position:0% +all they would they would they would + + + align:start position:0% +all they would they would they would +both go together though because I'd have + + align:start position:0% +both go together though because I'd have + + + align:start position:0% +both go together though because I'd have +the factor so back here on slide 12 if I + + align:start position:0% +the factor so back here on slide 12 if I + + + align:start position:0% +the factor so back here on slide 12 if I +change my sample size both Sigma a and + + align:start position:0% +change my sample size both Sigma a and + + + align:start position:0% +change my sample size both Sigma a and +my upper control limits and lower + + align:start position:0% +my upper control limits and lower + + + align:start position:0% +my upper control limits and lower +control limits the xar shrink exactly + + align:start position:0% +control limits the xar shrink exactly + + + align:start position:0% +control limits the xar shrink exactly +the same so I would scale both of them + + align:start position:0% +the same so I would scale both of them + + + align:start position:0% +the same so I would scale both of them +if I + + align:start position:0% +if I + + + align:start position:0% +if I +increased okay so what I was talking + + align:start position:0% +increased okay so what I was talking + + + align:start position:0% +increased okay so what I was talking +about here is with different values of + + align:start position:0% +about here is with different values of + + + align:start position:0% +about here is with different values of +of + + align:start position:0% +of + + + align:start position:0% +of +R so um this was an r equal 0.3 here's a + + align:start position:0% +R so um this was an r equal 0.3 here's a + + + align:start position:0% +R so um this was an r equal 0.3 here's a +smaller R R equals 0.1 so what's + + align:start position:0% +smaller R R equals 0.1 so what's + + + align:start position:0% +smaller R R equals 0.1 so what's +happening here I'm only accepting my + + align:start position:0% +happening here I'm only accepting my + + + align:start position:0% +happening here I'm only accepting my +most recent data 10% and mixing past + + align:start position:0% +most recent data 10% and mixing past + + + align:start position:0% +most recent data 10% and mixing past +history in 90% that's more averaging of + + align:start position:0% +history in 90% that's more averaging of + + + align:start position:0% +history in 90% that's more averaging of +the past I'm using more past history and + + align:start position:0% +the past I'm using more past history and + + + align:start position:0% +the past I'm using more past history and +so in this case what you see is kind of + + align:start position:0% +so in this case what you see is kind of + + + align:start position:0% +so in this case what you see is kind of +a more slowly + + align:start position:0% + + + + align:start position:0% + +drifting a more heavily excuse me a more + + align:start position:0% +drifting a more heavily excuse me a more + + + align:start position:0% +drifting a more heavily excuse me a more +heavily filtered version and here with + + align:start position:0% +heavily filtered version and here with + + + align:start position:0% +heavily filtered version and here with +the mean shift occurring about here you + + align:start position:0% +the mean shift occurring about here you + + + align:start position:0% +the mean shift occurring about here you +can start to see in this case a big mean + + align:start position:0% +can start to see in this case a big mean + + + align:start position:0% +can start to see in this case a big mean +shift of 0.5 with a I guess a sample + + align:start position:0% +shift of 0.5 with a I guess a sample + + + align:start position:0% +shift of 0.5 with a I guess a sample +size of of of five + + align:start position:0% +size of of of five + + + align:start position:0% +size of of of five +you do need to know the sample size in + + align:start position:0% +you do need to know the sample size in + + + align:start position:0% +you do need to know the sample size in +order to know the effect of the mean + + align:start position:0% +order to know the effect of the mean + + + align:start position:0% +order to know the effect of the mean +shift um and the ability to detect with + + align:start position:0% +shift um and the ability to detect with + + + align:start position:0% +shift um and the ability to detect with +either either + + align:start position:0% +either either + + + align:start position:0% +either either +chart so somewhere in here I guess + + align:start position:0% +chart so somewhere in here I guess + + + align:start position:0% +chart so somewhere in here I guess +around there I got I got lucky and I'm + + align:start position:0% +around there I got I got lucky and I'm + + + align:start position:0% +around there I got I got lucky and I'm +starting the sample + + align:start position:0% +starting the sample + + + align:start position:0% +starting the sample +now with the + + align:start position:0% +now with the + + + align:start position:0% +now with the +xar picking up that detection but with + + align:start position:0% +xar picking up that detection but with + + + align:start position:0% +xar picking up that detection but with +the ewma in some sense I've still got + + align:start position:0% +the ewma in some sense I've still got + + + align:start position:0% +the ewma in some sense I've still got +90% it takes you know nine or 10 days + + align:start position:0% +90% it takes you know nine or 10 days + + + align:start position:0% +90% it takes you know nine or 10 days +data points for the more recent data to + + align:start position:0% +data points for the more recent data to + + + align:start position:0% +data points for the more recent data to +outweigh the past data and so I've + + align:start position:0% +outweigh the past data and so I've + + + align:start position:0% +outweigh the past data and so I've +actually got in this case a time lag in + + align:start position:0% +actually got in this case a time lag in + + + align:start position:0% +actually got in this case a time lag in +in detecting the mean shift with the + + align:start position:0% +in detecting the mean shift with the + + + align:start position:0% +in detecting the mean shift with the +ewma compared to + + align:start position:0% +ewma compared to + + + align:start position:0% +ewma compared to +the uh + + align:start position:0% +the uh + + + align:start position:0% +the uh +xar so a question here + + align:start position:0% + + + + align:start position:0% + +first different + + align:start position:0% +first different + + + align:start position:0% +first different +sces on the xar will effectively let us + + align:start position:0% +sces on the xar will effectively let us + + + align:start position:0% +sces on the xar will effectively let us +save the sample sizes by effectively + + align:start position:0% +save the sample sizes by effectively + + + align:start position:0% +save the sample sizes by effectively +moving for five time SC the other moving + + align:start position:0% + + + + align:start position:0% + +one uh so the question was how do you + + align:start position:0% +one uh so the question was how do you + + + align:start position:0% +one uh so the question was how do you +compare the time scales on these so + + align:start position:0% +compare the time scales on these so + + + align:start position:0% +compare the time scales on these so +here's what I think is going on uh and + + align:start position:0% +here's what I think is going on uh and + + + align:start position:0% +here's what I think is going on uh and +this is sort of what I was talking about + + align:start position:0% +this is sort of what I was talking about + + + align:start position:0% +this is sort of what I was talking about +a second ago but it's it's probably + + align:start position:0% +a second ago but it's it's probably + + + align:start position:0% +a second ago but it's it's probably +still a little confusing I believe that + + align:start position:0% +still a little confusing I believe that + + + align:start position:0% +still a little confusing I believe that +this n equals 5 sample size means that + + align:start position:0% +this n equals 5 sample size means that + + + align:start position:0% +this n equals 5 sample size means that +inside of this data point if I were to + + align:start position:0% +inside of this data point if I were to + + + align:start position:0% +inside of this data point if I were to +explode that it actually has five five + + align:start position:0% +explode that it actually has five five + + + align:start position:0% +explode that it actually has five five +data points inside of it and I'm only + + align:start position:0% +data points inside of it and I'm only + + + align:start position:0% +data points inside of it and I'm only +plotting the average of those five on + + align:start position:0% +plotting the average of those five on + + + align:start position:0% +plotting the average of those five on +here this data point also has those same + + align:start position:0% +here this data point also has those same + + + align:start position:0% +here this data point also has those same +five data points but then it also + + align:start position:0% +five data points but then it also + + + align:start position:0% +five data points but then it also +grabbed the data that was lurking in the + + align:start position:0% +grabbed the data that was lurking in the + + + align:start position:0% +grabbed the data that was lurking in the +previous one and it has its five data + + align:start position:0% +previous one and it has its five data + + + align:start position:0% +previous one and it has its five data +points and it's five so it's + + align:start position:0% +points and it's five so it's + + + align:start position:0% +points and it's five so it's +whoops yeah + + align:start position:0% + + + + align:start position:0% + +don't want + + align:start position:0% + + + + align:start position:0% + +to I think it was trying to uh exit me + + align:start position:0% +to I think it was trying to uh exit me + + + align:start position:0% +to I think it was trying to uh exit me +out + + align:start position:0% +out + + + align:start position:0% +out +here so while it's doing that the the + + align:start position:0% +here so while it's doing that the the + + + align:start position:0% +here so while it's doing that the the +point here was that that uh the N equals + + align:start position:0% +point here was that that uh the N equals + + + align:start position:0% +point here was that that uh the N equals +5 is not is not looking back five data + + align:start position:0% +5 is not is not looking back five data + + + align:start position:0% +5 is not is not looking back five data +points in the xar it's buried in each of + + align:start position:0% +points in the xar it's buried in each of + + + align:start position:0% +points in the xar it's buried in each of +the individual points so that both both + + align:start position:0% +the individual points so that both both + + + align:start position:0% +the individual points so that both both +ewma + + align:start position:0% +ewma + + + align:start position:0% +ewma +and both ewma and uh uh + + align:start position:0% +and both ewma and uh uh + + + align:start position:0% +and both ewma and uh uh +xbar are are are not affected by this n + + align:start position:0% +xbar are are are not affected by this n + + + align:start position:0% +xbar are are are not affected by this n +equals 5 sampling differently but then + + align:start position:0% +equals 5 sampling differently but then + + + align:start position:0% +equals 5 sampling differently but then +the time scale is correct in terms of + + align:start position:0% +the time scale is correct in terms of + + + align:start position:0% +the time scale is correct in terms of +xar only looks at my most recent sample + + align:start position:0% +xar only looks at my most recent sample + + + align:start position:0% +xar only looks at my most recent sample +the ewma does look back in history and + + align:start position:0% +the ewma does look back in history and + + + align:start position:0% +the ewma does look back in history and +that's why you've got this additional + + align:start position:0% +that's why you've got this additional + + + align:start position:0% +that's why you've got this additional +time lag was that getting at your + + align:start position:0% +time lag was that getting at your + + + align:start position:0% +time lag was that getting at your +question or your observation or is your + + align:start position:0% +question or your observation or is your + + + align:start position:0% +question or your observation or is your +question a little + + align:start position:0% +question a little + + + align:start position:0% +question a little +different okay okay and there was a + + align:start position:0% +different okay okay and there was a + + + align:start position:0% +different okay okay and there was a +question in + + align:start position:0% +question in + + + align:start position:0% +question in +Singapore yes so uh my question is sort + + align:start position:0% +Singapore yes so uh my question is sort + + + align:start position:0% +Singapore yes so uh my question is sort +of built on what Steven was asking so + + align:start position:0% +of built on what Steven was asking so + + + align:start position:0% +of built on what Steven was asking so +for a smaller R uh you have a higher + + align:start position:0% +for a smaller R uh you have a higher + + + align:start position:0% +for a smaller R uh you have a higher +probability of detecting the mean shift + + align:start position:0% +probability of detecting the mean shift + + + align:start position:0% +probability of detecting the mean shift +but at the same time for a smaller R the + + align:start position:0% +but at the same time for a smaller R the + + + align:start position:0% +but at the same time for a smaller R the +time it takes for you to detect the mean + + align:start position:0% +time it takes for you to detect the mean + + + align:start position:0% +time it takes for you to detect the mean +shift is longer how does these two + + align:start position:0% +shift is longer how does these two + + + align:start position:0% +shift is longer how does these two +coexist + + align:start position:0% +coexist + + + align:start position:0% +coexist +while you know it's you have higher + + align:start position:0% +while you know it's you have higher + + + align:start position:0% +while you know it's you have higher +chance of detecting it but it takes + + align:start position:0% +chance of detecting it but it takes + + + align:start position:0% +chance of detecting it but it takes +longer as well yes uh they're a + + align:start position:0% +longer as well yes uh they're a + + + align:start position:0% +longer as well yes uh they're a +trade-off and so so what you are + + align:start position:0% +trade-off and so so what you are + + + align:start position:0% +trade-off and so so what you are +basically given is a degree of Freedom + + align:start position:0% +basically given is a degree of Freedom + + + align:start position:0% +basically given is a degree of Freedom +that you get to play with or experiment + + align:start position:0% +that you get to play with or experiment + + + align:start position:0% +that you get to play with or experiment +with or adapt to your process so what + + align:start position:0% +with or adapt to your process so what + + + align:start position:0% +with or adapt to your process so what +are the factors in adapting to your + + align:start position:0% +are the factors in adapting to your + + + align:start position:0% +are the factors in adapting to your +process if your process is really noisy + + align:start position:0% +process if your process is really noisy + + + align:start position:0% +process if your process is really noisy +and you think it's going to be hard to + + align:start position:0% +and you think it's going to be hard to + + + align:start position:0% +and you think it's going to be hard to +detect a mean shift in the face of that + + align:start position:0% +detect a mean shift in the face of that + + + align:start position:0% +detect a mean shift in the face of that +noise then you do more averaging you'd + + align:start position:0% +noise then you do more averaging you'd + + + align:start position:0% +noise then you do more averaging you'd +have a smaller R if you're trying to + + align:start position:0% +have a smaller R if you're trying to + + + align:start position:0% +have a smaller R if you're trying to +detect maybe with a higher risk of a + + align:start position:0% +detect maybe with a higher risk of a + + + align:start position:0% +detect maybe with a higher risk of a +false alarm but you're trying to detect + + align:start position:0% +false alarm but you're trying to detect + + + align:start position:0% +false alarm but you're trying to detect +more quickly then I'd have a larger R so + + align:start position:0% +more quickly then I'd have a larger R so + + + align:start position:0% +more quickly then I'd have a larger R so +it it responds faster but doesn't filter + + align:start position:0% +it it responds faster but doesn't filter + + + align:start position:0% +it it responds faster but doesn't filter +as much so you can see here with the R + + align:start position:0% +as much so you can see here with the R + + + align:start position:0% +as much so you can see here with the R +equals + + align:start position:0% +equals + + + align:start position:0% +equals +0.1 versus the R equals 0.3 this is the + + align:start position:0% +0.1 versus the R equals 0.3 this is the + + + align:start position:0% +0.1 versus the R equals 0.3 this is the +same data I believe is this the same + + align:start position:0% +same data I believe is this the same + + + align:start position:0% +same data I believe is this the same +data I I guess not it's just another + + align:start position:0% +data I I guess not it's just another + + + align:start position:0% +data I I guess not it's just another +example here's an r equal 0.3 uh kind of + + align:start position:0% +example here's an r equal 0.3 uh kind of + + + align:start position:0% +example here's an r equal 0.3 uh kind of +case + + align:start position:0% +case + + + align:start position:0% +case +where um you know for this data this + + align:start position:0% +where um you know for this data this + + + align:start position:0% +where um you know for this data this +looks like about the right tradeoff I'm + + align:start position:0% +looks like about the right tradeoff I'm + + + align:start position:0% +looks like about the right tradeoff I'm +getting reasonable filtering the black + + align:start position:0% +getting reasonable filtering the black + + + align:start position:0% +getting reasonable filtering the black +dots are my + + align:start position:0% +dots are my + + + align:start position:0% +dots are my +ewma and for a a mean shift here I've + + align:start position:0% +ewma and for a a mean shift here I've + + + align:start position:0% +ewma and for a a mean shift here I've +got very + + align:start position:0% +got very + + + align:start position:0% +got very +rapid I've got sort of Rapid + + align:start position:0% +rapid I've got sort of Rapid + + + align:start position:0% +rapid I've got sort of Rapid +detection much more rapid than in fact + + align:start position:0% +detection much more rapid than in fact + + + align:start position:0% +detection much more rapid than in fact +the uh xar which doesn't really trigger + + align:start position:0% +the uh xar which doesn't really trigger + + + align:start position:0% +the uh xar which doesn't really trigger +finally until way you know another 20 25 + + align:start position:0% +finally until way you know another 20 25 + + + align:start position:0% +finally until way you know another 20 25 +runs + + align:start position:0% +runs + + + align:start position:0% +runs +later um so i' I I I think what you'd + + align:start position:0% +later um so i' I I I think what you'd + + + align:start position:0% +later um so i' I I I think what you'd +have to do is again make the tradeoffs + + align:start position:0% +have to do is again make the tradeoffs + + + align:start position:0% +have to do is again make the tradeoffs +between + + align:start position:0% +between + + + align:start position:0% +between +responsivity the size of the shift that + + align:start position:0% +responsivity the size of the shift that + + + align:start position:0% +responsivity the size of the shift that +you're trying to detect and how much + + align:start position:0% +you're trying to detect and how much + + + align:start position:0% +you're trying to detect and how much +costs you to uh have different delays in + + align:start position:0% +costs you to uh have different delays in + + + align:start position:0% +costs you to uh have different delays in +detecting the shift so we got two + + align:start position:0% +detecting the shift so we got two + + + align:start position:0% +detecting the shift so we got two +questions here one one here first is + + align:start position:0% +questions here one one here first is + + + align:start position:0% +questions here one one here first is +that ESS because it's almost like taking + + align:start position:0% +that ESS because it's almost like taking + + + align:start position:0% +that ESS because it's almost like taking +lar + + align:start position:0% + + + + align:start position:0% + +samples you're taking five samples per + + align:start position:0% +samples you're taking five samples per + + + align:start position:0% +samples you're taking five samples per +five measurements per sample plus five + + align:start position:0% +five measurements per sample plus five + + + align:start position:0% +five measurements per sample plus five +previously at a slightly lower weight + + align:start position:0% +previously at a slightly lower weight + + + align:start position:0% +previously at a slightly lower weight +plus five at a lower weight plus five at + + align:start position:0% +plus five at a lower weight plus five at + + + align:start position:0% +plus five at a lower weight plus five at +a low weight so you're just taking more + + align:start position:0% +a low weight so you're just taking more + + + align:start position:0% +a low weight so you're just taking more +samples per more measurements per data + + align:start position:0% +samples per more measurements per data + + + align:start position:0% +samples per more measurements per data +point right yes so that that's a fair + + align:start position:0% +point right yes so that that's a fair + + + align:start position:0% +point right yes so that that's a fair +way of looking at it I that's a good way + + align:start position:0% +way of looking at it I that's a good way + + + align:start position:0% +way of looking at it I that's a good way +of looking at it so just so everybody + + align:start position:0% +of looking at it so just so everybody + + + align:start position:0% +of looking at it so just so everybody +could hear with the xar I'd take my n + + align:start position:0% +could hear with the xar I'd take my n + + + align:start position:0% +could hear with the xar I'd take my n +equals whatever sample but with the + + align:start position:0% +equals whatever sample but with the + + + align:start position:0% +equals whatever sample but with the +ewma I've still got that from my most + + align:start position:0% +ewma I've still got that from my most + + + align:start position:0% +ewma I've still got that from my most +recent update but I'm doing additional + + align:start position:0% +recent update but I'm doing additional + + + align:start position:0% +recent update but I'm doing additional +filtering or averaging of past history + + align:start position:0% +filtering or averaging of past history + + + align:start position:0% +filtering or averaging of past history +in and the net effect of that is I've + + align:start position:0% +in and the net effect of that is I've + + + align:start position:0% +in and the net effect of that is I've +got a net aggregate more number of + + align:start position:0% +got a net aggregate more number of + + + align:start position:0% +got a net aggregate more number of +samples if you will unequally weighted + + align:start position:0% +samples if you will unequally weighted + + + align:start position:0% +samples if you will unequally weighted +but a more and therefore that makes + + align:start position:0% +but a more and therefore that makes + + + align:start position:0% +but a more and therefore that makes +perfect sense that your control limits + + align:start position:0% +perfect sense that your control limits + + + align:start position:0% +perfect sense that your control limits +come down that's exactly a good that's a + + align:start position:0% +come down that's exactly a good that's a + + + align:start position:0% +come down that's exactly a good that's a +very good way of looking at it so in the + + align:start position:0% +very good way of looking at it so in the + + + align:start position:0% +very good way of looking at it so in the +previous example does EW also trigger + + align:start position:0% +previous example does EW also trigger + + + align:start position:0% +previous example does EW also trigger +before X oh yes good point good point + + align:start position:0% +before X oh yes good point good point + + + align:start position:0% +before X oh yes good point good point +yes is there ever a case when X + + align:start position:0% +yes is there ever a case when X + + + align:start position:0% +yes is there ever a case when X +trigger good question is there are there + + align:start position:0% +trigger good question is there are there + + + align:start position:0% +trigger good question is there are there +ever situations where xbar might trigger + + align:start position:0% +ever situations where xbar might trigger + + + align:start position:0% +ever situations where xbar might trigger +still before an ewma for an xar + + align:start position:0% +still before an ewma for an xar + + + align:start position:0% +still before an ewma for an xar +chart um I don't quite know the + + align:start position:0% +chart um I don't quite know the + + + align:start position:0% +chart um I don't quite know the +tradeoffs and where what where where you + + align:start position:0% +tradeoffs and where what where where you + + + align:start position:0% +tradeoffs and where what where where you +get in the limits of the tradeoff I + + align:start position:0% +get in the limits of the tradeoff I + + + align:start position:0% +get in the limits of the tradeoff I +suspect you know you've always got ch + + align:start position:0% +suspect you know you've always got ch + + + align:start position:0% +suspect you know you've always got ch +at work and I suspect that with a large + + align:start position:0% +at work and I suspect that with a large + + + align:start position:0% +at work and I suspect that with a large +enough so I the following scenario + + align:start position:0% +enough so I the following scenario + + + align:start position:0% +enough so I the following scenario +probably comes closest let's say you had + + align:start position:0% +probably comes closest let's say you had + + + align:start position:0% +probably comes closest let's say you had +a very large mean shift but a very small + + align:start position:0% +a very large mean shift but a very small + + + align:start position:0% +a very large mean shift but a very small +R okay with an xar I react entirely to a + + align:start position:0% +R okay with an xar I react entirely to a + + + align:start position:0% +R okay with an xar I react entirely to a +sample drawn from the very large mean + + align:start position:0% +sample drawn from the very large mean + + + align:start position:0% +sample drawn from the very large mean +shift let's say it was a two Sigma or a + + align:start position:0% +shift let's say it was a two Sigma or a + + + align:start position:0% +shift let's say it was a two Sigma or a +three sigma mean shift but I have a very + + align:start position:0% +three sigma mean shift but I have a very + + + align:start position:0% +three sigma mean shift but I have a very +small R maybe I'm only calling that + + align:start position:0% +small R maybe I'm only calling that + + + align:start position:0% +small R maybe I'm only calling that +05 that 5% mix in of that most recent + + align:start position:0% +05 that 5% mix in of that most recent + + + align:start position:0% +05 that 5% mix in of that most recent +data point is probably swamped out by my + + align:start position:0% +data point is probably swamped out by my + + + align:start position:0% +data point is probably swamped out by my +past data still and so in that case I + + align:start position:0% +past data still and so in that case I + + + align:start position:0% +past data still and so in that case I +think my ewma would likely not detect + + align:start position:0% +think my ewma would likely not detect + + + align:start position:0% +think my ewma would likely not detect +the mean + + align:start position:0% +the mean + + + align:start position:0% +the mean +shift so I think of the ewma is + + align:start position:0% +shift so I think of the ewma is + + + align:start position:0% +shift so I think of the ewma is +especially good for improving + + align:start position:0% +especially good for improving + + + align:start position:0% +especially good for improving +responsivity and detection ability for + + align:start position:0% +responsivity and detection ability for + + + align:start position:0% +responsivity and detection ability for +small effects because it's aggregating + + align:start position:0% +small effects because it's aggregating + + + align:start position:0% +small effects because it's aggregating +just like the qon that we'll see in a + + align:start position:0% +just like the qon that we'll see in a + + + align:start position:0% +just like the qon that we'll see in a +second but I think if there are really + + align:start position:0% +second but I think if there are really + + + align:start position:0% +second but I think if there are really +big bigger effects you lose by the f in + + align:start position:0% +big bigger effects you lose by the f in + + + align:start position:0% +big bigger effects you lose by the f in +in the time time + + align:start position:0% +in the time time + + + align:start position:0% +in the time time +response was that an example you're + + align:start position:0% +response was that an example you're + + + align:start position:0% +response was that an example you're +going to + + align:start position:0% +going to + + + align:start position:0% +going to +suggest + + align:start position:0% + + + + align:start position:0% + +think oh good + + align:start position:0% + + + + align:start position:0% + +point + + align:start position:0% + + + + align:start position:0% + +yeah yeah yeah so so other rules here + + align:start position:0% +yeah yeah yeah so so other rules here + + + align:start position:0% +yeah yeah yeah so so other rules here +would help yeah + + align:start position:0% +would help yeah + + + align:start position:0% +would help yeah +absolutely okay so + + align:start position:0% + + + + align:start position:0% + +I guess this is sort of saying a little + + align:start position:0% +I guess this is sort of saying a little + + + align:start position:0% +I guess this is sort of saying a little +bit the same thing this I think is + + align:start position:0% +bit the same thing this I think is + + + align:start position:0% +bit the same thing this I think is +really good for small mean shifts um + + align:start position:0% +really good for small mean shifts um + + + align:start position:0% +really good for small mean shifts um +that are persistent it's not a onetime + + align:start position:0% +that are persistent it's not a onetime + + + align:start position:0% +that are persistent it's not a onetime +shot but I've got a a Delta Mu mean + + align:start position:0% +shot but I've got a a Delta Mu mean + + + align:start position:0% +shot but I've got a a Delta Mu mean +shift and this allows us to aggregate + + align:start position:0% +shift and this allows us to aggregate + + + align:start position:0% +shift and this allows us to aggregate +but there are additional ideas we can + + align:start position:0% +but there are additional ideas we can + + + align:start position:0% +but there are additional ideas we can +use Yeah question first electric + + align:start position:0% +use Yeah question first electric + + + align:start position:0% +use Yeah question first electric +don't no you would not want to Al so uh + + align:start position:0% +don't no you would not want to Al so uh + + + align:start position:0% +don't no you would not want to Al so uh +I think Hayden's Point here was on the + + align:start position:0% +I think Hayden's Point here was on the + + + align:start position:0% +I think Hayden's Point here was on the +purple data points you might apply which + + align:start position:0% +purple data points you might apply which + + + align:start position:0% +purple data points you might apply which +was just a an xar you might apply the + + align:start position:0% +was just a an xar you might apply the + + + align:start position:0% +was just a an xar you might apply the +weo rules but you should not there might + + align:start position:0% +weo rules but you should not there might + + + align:start position:0% +weo rules but you should not there might +be variants you could derive of some of + + align:start position:0% +be variants you could derive of some of + + + align:start position:0% +be variants you could derive of some of +the other weo + + align:start position:0% +the other weo + + + align:start position:0% +the other weo +rules but I don't know how you would how + + align:start position:0% +rules but I don't know how you would how + + + align:start position:0% +rules but I don't know how you would how +you would do that it's not intuitive I + + align:start position:0% +you would do that it's not intuitive I + + + align:start position:0% +you would do that it's not intuitive I +think for the ewma you pretty much are + + align:start position:0% +think for the ewma you pretty much are + + + align:start position:0% +think for the ewma you pretty much are +just trying to track the the mean and + + align:start position:0% +just trying to track the the mean and + + + align:start position:0% +just trying to track the the mean and +not additional Trends or + + align:start position:0% +not additional Trends or + + + align:start position:0% +not additional Trends or +so so I wouldn't I would not use any of + + align:start position:0% +so so I wouldn't I would not use any of + + + align:start position:0% +so so I wouldn't I would not use any of +the additional weo rules with an ewma + + align:start position:0% +the additional weo rules with an ewma + + + align:start position:0% +the additional weo rules with an ewma +chart so there's another chart that is + + align:start position:0% +chart so there's another chart that is + + + align:start position:0% +chart so there's another chart that is +very often used that's called a q sum + + align:start position:0% +very often used that's called a q sum + + + align:start position:0% +very often used that's called a q sum +and I just want to give you a quick feel + + align:start position:0% +and I just want to give you a quick feel + + + align:start position:0% +and I just want to give you a quick feel +for that and then move to some + + align:start position:0% +for that and then move to some + + + align:start position:0% +for that and then move to some +multivariate issues um which is + + align:start position:0% +multivariate issues um which is + + + align:start position:0% +multivariate issues um which is +also targeted at this idea that when I + + align:start position:0% +also targeted at this idea that when I + + + align:start position:0% +also targeted at this idea that when I +have a small mean shift what I'd like to + + align:start position:0% +have a small mean shift what I'd like to + + + align:start position:0% +have a small mean shift what I'd like to +do is use the fact that it is a + + align:start position:0% +do is use the fact that it is a + + + align:start position:0% +do is use the fact that it is a +persistent mean shift that I'm then + + align:start position:0% +persistent mean shift that I'm then + + + align:start position:0% +persistent mean shift that I'm then +sampling around within the process noise + + align:start position:0% +sampling around within the process noise + + + align:start position:0% +sampling around within the process noise +and if there were a simple way to + + align:start position:0% +and if there were a simple way to + + + align:start position:0% +and if there were a simple way to +aggregate the mean shift over many data + + align:start position:0% +aggregate the mean shift over many data + + + align:start position:0% +aggregate the mean shift over many data +points in the past I build up a signal + + align:start position:0% +points in the past I build up a signal + + + align:start position:0% +points in the past I build up a signal +that's larger and might improve my + + align:start position:0% +that's larger and might improve my + + + align:start position:0% +that's larger and might improve my +ability to uh detect that effect and + + align:start position:0% +ability to uh detect that effect and + + + align:start position:0% +ability to uh detect that effect and +reduce the average run length for for + + align:start position:0% +reduce the average run length for for + + + align:start position:0% +reduce the average run length for for +detecting that effect and this Q sum or + + align:start position:0% +detecting that effect and this Q sum or + + + align:start position:0% +detecting that effect and this Q sum or +cumulative sum is another way of + + align:start position:0% +cumulative sum is another way of + + + align:start position:0% +cumulative sum is another way of +thinking of it as a filter and in this + + align:start position:0% +thinking of it as a filter and in this + + + align:start position:0% +thinking of it as a filter and in this +case just a discrete time integrator + + align:start position:0% +case just a discrete time integrator + + + align:start position:0% +case just a discrete time integrator +which is looking at the sum of + + align:start position:0% +which is looking at the sum of + + + align:start position:0% +which is looking at the sum of +deviations of each of my sample point + + align:start position:0% +deviations of each of my sample point + + + align:start position:0% +deviations of each of my sample point +from the assumed grand mean so I'm not + + align:start position:0% +from the assumed grand mean so I'm not + + + align:start position:0% +from the assumed grand mean so I'm not +just filtering and plotting the average + + align:start position:0% +just filtering and plotting the average + + + align:start position:0% +just filtering and plotting the average +but I'm saying asking the question am I + + align:start position:0% +but I'm saying asking the question am I + + + align:start position:0% +but I'm saying asking the question am I +still in control at my assumed xbar bar + + align:start position:0% +still in control at my assumed xbar bar + + + align:start position:0% +still in control at my assumed xbar bar +my my mu not and if I'm not then this + + align:start position:0% +my my mu not and if I'm not then this + + + align:start position:0% +my my mu not and if I'm not then this +statistic this sum of being to one side + + align:start position:0% +statistic this sum of being to one side + + + align:start position:0% +statistic this sum of being to one side +of it the C subj here will grow if I've + + align:start position:0% +of it the C subj here will grow if I've + + + align:start position:0% +of it the C subj here will grow if I've +got a plus mean shift or it'll become + + align:start position:0% +got a plus mean shift or it'll become + + + align:start position:0% +got a plus mean shift or it'll become +more and more negative and grow if I've + + align:start position:0% +more and more negative and grow if I've + + + align:start position:0% +more and more negative and grow if I've +got a negative uh mean shift so that + + align:start position:0% +got a negative uh mean shift so that + + + align:start position:0% +got a negative uh mean shift so that +I'll convert a mean shift to an + + align:start position:0% +I'll convert a mean shift to an + + + align:start position:0% +I'll convert a mean shift to an +integration of a mean shift the mean + + align:start position:0% +integration of a mean shift the mean + + + align:start position:0% +integration of a mean shift the mean +shift is a step the integration of a + + align:start position:0% +shift is a step the integration of a + + + align:start position:0% +shift is a step the integration of a +step response is + + align:start position:0% +step response is + + + align:start position:0% +step response is +a ramp right so what we would hope to do + + align:start position:0% +a ramp right so what we would hope to do + + + align:start position:0% +a ramp right so what we would hope to do +with a Q sum chart is in improve our + + align:start position:0% +with a Q sum chart is in improve our + + + align:start position:0% +with a Q sum chart is in improve our +mean shift sensitivity and basically + + align:start position:0% +mean shift sensitivity and basically + + + align:start position:0% +mean shift sensitivity and basically +have charts that look like this when + + align:start position:0% +have charts that look like this when + + + align:start position:0% +have charts that look like this when +when I'm in + + align:start position:0% +when I'm in + + + align:start position:0% +when I'm in +control I might wander around the + + align:start position:0% +control I might wander around the + + + align:start position:0% +control I might wander around the +mean you know sometimes I'll be above + + align:start position:0% +mean you know sometimes I'll be above + + + align:start position:0% +mean you know sometimes I'll be above +sometimes below so this C subj this + + align:start position:0% +sometimes below so this C subj this + + + align:start position:0% +sometimes below so this C subj this +cumulative statistic does wander around + + align:start position:0% +cumulative statistic does wander around + + + align:start position:0% +cumulative statistic does wander around +a bit but if I do have a mean shift on + + align:start position:0% +a bit but if I do have a mean shift on + + + align:start position:0% +a bit but if I do have a mean shift on +average I keep adding to that that c + + align:start position:0% +average I keep adding to that that c + + + align:start position:0% +average I keep adding to that that c +subj sometimes I might go down a little + + align:start position:0% +subj sometimes I might go down a little + + + align:start position:0% +subj sometimes I might go down a little +bit because I'm still have something a + + align:start position:0% +bit because I'm still have something a + + + align:start position:0% +bit because I'm still have something a +little bit below the mean and so what + + align:start position:0% +little bit below the mean and so what + + + align:start position:0% +little bit below the mean and so what +you create is this this ramp you create + + align:start position:0% +you create is this this ramp you create + + + align:start position:0% +you create is this this ramp you create +a a slope caused by that that mean + + align:start position:0% +a a slope caused by that that mean + + + align:start position:0% +a a slope caused by that that mean +shift now one can also now apply some + + align:start position:0% +shift now one can also now apply some + + + align:start position:0% +shift now one can also now apply some +statistics and + + align:start position:0% +statistics and + + + align:start position:0% +statistics and +design uh control limits for that c subj + + align:start position:0% +design uh control limits for that c subj + + + align:start position:0% +design uh control limits for that c subj +statistic or use a couple of other uh uh + + align:start position:0% +statistic or use a couple of other uh uh + + + align:start position:0% +statistic or use a couple of other uh uh +approaches and one approach is this + + align:start position:0% +approaches and one approach is this + + + align:start position:0% +approaches and one approach is this +so-called + + align:start position:0% +so-called + + + align:start position:0% +so-called +vask that says + + align:start position:0% +vask that says + + + align:start position:0% +vask that says +say it what I would like to do is if if + + align:start position:0% +say it what I would like to do is if if + + + align:start position:0% +say it what I would like to do is if if +in fact I've got a mean shift this + + align:start position:0% +in fact I've got a mean shift this + + + align:start position:0% +in fact I've got a mean shift this +slope let me let me erase a little bit + + align:start position:0% + + + + align:start position:0% + +here + + align:start position:0% + + + + align:start position:0% + +whoops there's so there's sort of two + + align:start position:0% +whoops there's so there's sort of two + + + align:start position:0% +whoops there's so there's sort of two +different approaches and I I I just want + + align:start position:0% +different approaches and I I I just want + + + align:start position:0% +different approaches and I I I just want +to briefly mention both of those for + + align:start position:0% +to briefly mention both of those for + + + align:start position:0% +to briefly mention both of those for +detecting things on these on these + + align:start position:0% +detecting things on these on these + + + align:start position:0% +detecting things on these on these +charts one is draw control limit for the + + align:start position:0% +charts one is draw control limit for the + + + align:start position:0% +charts one is draw control limit for the +aggregate of the C + + align:start position:0% +aggregate of the C + + + align:start position:0% +aggregate of the C +subj okay the other is to look and say + + align:start position:0% +subj okay the other is to look and say + + + align:start position:0% +subj okay the other is to look and say +once I've got a mean shift I start + + align:start position:0% +once I've got a mean shift I start + + + align:start position:0% +once I've got a mean shift I start +building data points with on average + + align:start position:0% +building data points with on average + + + align:start position:0% +building data points with on average +some slope that is different than a + + align:start position:0% +some slope that is different than a + + + align:start position:0% +some slope that is different than a +slope that I would + + align:start position:0% +slope that I would + + + align:start position:0% +slope that I would +expect by random chance alone just form + + align:start position:0% +expect by random chance alone just form + + + align:start position:0% +expect by random chance alone just form +form forming the sum statistic from a + + align:start position:0% +form forming the sum statistic from a + + + align:start position:0% +form forming the sum statistic from a +normally sampled uh process + + align:start position:0% + + + + align:start position:0% + +the tabular Q sum this idea of actually + + align:start position:0% +the tabular Q sum this idea of actually + + + align:start position:0% +the tabular Q sum this idea of actually +looking at the statistics of of let me + + align:start position:0% +looking at the statistics of of let me + + + align:start position:0% +looking at the statistics of of let me +skip this for a second uh this + + align:start position:0% +skip this for a second uh this + + + align:start position:0% +skip this for a second uh this +normalized statistic Z and S and looking + + align:start position:0% +normalized statistic Z and S and looking + + + align:start position:0% +normalized statistic Z and S and looking +and deciding on what control limits are + + align:start position:0% +and deciding on what control limits are + + + align:start position:0% +and deciding on what control limits are +and so on I'm actually going to skip + + align:start position:0% +and so on I'm actually going to skip + + + align:start position:0% +and so on I'm actually going to skip +that there's about five slides in here + + align:start position:0% +that there's about five slides in here + + + align:start position:0% +that there's about five slides in here +but it's described very nicely and I + + align:start position:0% +but it's described very nicely and I + + + align:start position:0% +but it's described very nicely and I +think chapter 8.1 in mon gum rate and I + + align:start position:0% +think chapter 8.1 in mon gum rate and I + + + align:start position:0% +think chapter 8.1 in mon gum rate and I +think that's pretty natur natural it's + + align:start position:0% +think that's pretty natur natural it's + + + align:start position:0% +think that's pretty natur natural it's +just sort of a statistic you know a + + align:start position:0% +just sort of a statistic you know a + + + align:start position:0% +just sort of a statistic you know a +little bit nag um you know confusing um + + align:start position:0% +little bit nag um you know confusing um + + + align:start position:0% +little bit nag um you know confusing um +uh derivation of the statistics that I + + align:start position:0% +uh derivation of the statistics that I + + + align:start position:0% +uh derivation of the statistics that I +just trust the statisticians to have + + align:start position:0% +just trust the statisticians to have + + + align:start position:0% +just trust the statisticians to have +done right um but there's also another + + align:start position:0% +done right um but there's also another + + + align:start position:0% +done right um but there's also another +picture here which is based on the slope + + align:start position:0% +picture here which is based on the slope + + + align:start position:0% +picture here which is based on the slope +idea and you can similarly derive some + + align:start position:0% +idea and you can similarly derive some + + + align:start position:0% +idea and you can similarly derive some +formulas based on uh Alpha and beta + + align:start position:0% +formulas based on uh Alpha and beta + + + align:start position:0% +formulas based on uh Alpha and beta +risks what size the Delta shift in the + + align:start position:0% +risks what size the Delta shift in the + + + align:start position:0% +risks what size the Delta shift in the +mean you would hope to uh detect and + + align:start position:0% +mean you would hope to uh detect and + + + align:start position:0% +mean you would hope to uh detect and +what kind of a slope you would expect to + + align:start position:0% +what kind of a slope you would expect to + + + align:start position:0% +what kind of a slope you would expect to +see uh in those cases and so you've got + + align:start position:0% +see uh in those cases and so you've got + + + align:start position:0% +see uh in those cases and so you've got +these two parameters that go towards the + + align:start position:0% +these two parameters that go towards the + + + align:start position:0% +these two parameters that go towards the +formulation of this V mask that you + + align:start position:0% +formulation of this V mask that you + + + align:start position:0% +formulation of this V mask that you +overlay on your data + + align:start position:0% +overlay on your data + + + align:start position:0% +overlay on your data +points based on an expected slope and + + align:start position:0% +points based on an expected slope and + + + align:start position:0% +points based on an expected slope and +you need a certain number of data points + + align:start position:0% +you need a certain number of data points + + + align:start position:0% +you need a certain number of data points +in order to be able to build up your + + align:start position:0% +in order to be able to build up your + + + align:start position:0% +in order to be able to build up your +estimate of the slope that's the Dead + + align:start position:0% +estimate of the slope that's the Dead + + + align:start position:0% +estimate of the slope that's the Dead +Zone and what you do for each data point + + align:start position:0% +Zone and what you do for each data point + + + align:start position:0% +Zone and what you do for each data point +here is overlay sort of the V mask and + + align:start position:0% +here is overlay sort of the V mask and + + + align:start position:0% +here is overlay sort of the V mask and +say look back in time and see did any of + + align:start position:0% +say look back in time and see did any of + + + align:start position:0% +say look back in time and see did any of +these points intersect with the The + + align:start position:0% +these points intersect with the The + + + align:start position:0% +these points intersect with the The +Mask have a higher slope than you would + + align:start position:0% +Mask have a higher slope than you would + + + align:start position:0% +Mask have a higher slope than you would +have expected and then you update that + + align:start position:0% +have expected and then you update that + + + align:start position:0% +have expected and then you update that +on a running basis so in this case here + + align:start position:0% +on a running basis so in this case here + + + align:start position:0% +on a running basis so in this case here +at time Point 18 or 19 whatever that is + + align:start position:0% +at time Point 18 or 19 whatever that is + + + align:start position:0% +at time Point 18 or 19 whatever that is +everything looks fine I go up everything + + align:start position:0% +everything looks fine I go up everything + + + align:start position:0% +everything looks fine I go up everything +is still looking fine still here I'm + + align:start position:0% +is still looking fine still here I'm + + + align:start position:0% +is still looking fine still here I'm +starting to get some evidence maybe that + + align:start position:0% +starting to get some evidence maybe that + + + align:start position:0% +starting to get some evidence maybe that +that things have changed but + + align:start position:0% +that things have changed but + + + align:start position:0% +that things have changed but +statistically speaking that's still + + align:start position:0% +statistically speaking that's still + + + align:start position:0% +statistically speaking that's still +within the range that I would expect + + align:start position:0% +within the range that I would expect + + + align:start position:0% +within the range that I would expect +with some Alpha + + align:start position:0% +with some Alpha + + + align:start position:0% +with some Alpha +error but then finally I get to a a a + + align:start position:0% +error but then finally I get to a a a + + + align:start position:0% +error but then finally I get to a a a +new data point here at time 23 where in + + align:start position:0% +new data point here at time 23 where in + + + align:start position:0% +new data point here at time 23 where in +aggregate I've got some indication that + + align:start position:0% +aggregate I've got some indication that + + + align:start position:0% +aggregate I've got some indication that +the slope is is too large so this is + + align:start position:0% +the slope is is too large so this is + + + align:start position:0% +the slope is is too large so this is +kind of a intuitive graphical approach + + align:start position:0% +kind of a intuitive graphical approach + + + align:start position:0% +kind of a intuitive graphical approach +that's talking about the slope + + align:start position:0% +that's talking about the slope + + + align:start position:0% +that's talking about the slope +associated with uh + + align:start position:0% +associated with uh + + + align:start position:0% +associated with uh +um a mean shift in the qm statistic yes + + align:start position:0% +um a mean shift in the qm statistic yes + + + align:start position:0% +um a mean shift in the qm statistic yes +would you also um perform a lar + + align:start position:0% +would you also um perform a lar + + + align:start position:0% +would you also um perform a lar +regression for the + + align:start position:0% +regression for the + + + align:start position:0% +regression for the +last so the question is can you perform + + align:start position:0% +last so the question is can you perform + + + align:start position:0% +last so the question is can you perform +a linear regression and and uh calculate + + align:start position:0% +a linear regression and and uh calculate + + + align:start position:0% +a linear regression and and uh calculate +the slope of that and I think that's + + align:start position:0% +the slope of that and I think that's + + + align:start position:0% +the slope of that and I think that's +identical to what this is doing + + align:start position:0% +identical to what this is doing + + + align:start position:0% +identical to what this is doing +graphically so in fact if you were + + align:start position:0% +graphically so in fact if you were + + + align:start position:0% +graphically so in fact if you were +numerically or you know implementing an + + align:start position:0% +numerically or you know implementing an + + + align:start position:0% +numerically or you know implementing an +automatic version of this that that + + align:start position:0% +automatic version of this that that + + + align:start position:0% +automatic version of this that that +would probably be how you would how you + + align:start position:0% +would probably be how you would how you + + + align:start position:0% +would probably be how you would how you +would implement + + align:start position:0% +would implement + + + align:start position:0% +would implement +it that might even give you some more + + align:start position:0% +it that might even give you some more + + + align:start position:0% +it that might even give you some more +flexibility in terms of looking at the + + align:start position:0% +flexibility in terms of looking at the + + + align:start position:0% +flexibility in terms of looking at the +goodness of that fit um but I think it's + + align:start position:0% +goodness of that fit um but I think it's + + + align:start position:0% +goodness of that fit um but I think it's +essentially identical to + + align:start position:0% +essentially identical to + + + align:start position:0% +essentially identical to +this okay so just to summarize these + + align:start position:0% +this okay so just to summarize these + + + align:start position:0% +this okay so just to summarize these +alternative charts there's a few simple + + align:start position:0% +alternative charts there's a few simple + + + align:start position:0% +alternative charts there's a few simple +messages uh noisy data if you're trying + + align:start position:0% +messages uh noisy data if you're trying + + + align:start position:0% +messages uh noisy data if you're trying +to detect a mean in the noisy data you + + align:start position:0% +to detect a mean in the noisy data you + + + align:start position:0% +to detect a mean in the noisy data you +might want to use some filtering we have + + align:start position:0% +might want to use some filtering we have + + + align:start position:0% +might want to use some filtering we have +the sample size that does some filtering + + align:start position:0% +the sample size that does some filtering + + + align:start position:0% +the sample size that does some filtering +but I might want to use more data in the + + align:start position:0% +but I might want to use more data in the + + + align:start position:0% +but I might want to use more data in the +past and uh sort of this linear discrete + + align:start position:0% +past and uh sort of this linear discrete + + + align:start position:0% +past and uh sort of this linear discrete +filtering either with the Q sum as a + + align:start position:0% +filtering either with the Q sum as a + + + align:start position:0% +filtering either with the Q sum as a +running integrator or an + + align:start position:0% +running integrator or an + + + align:start position:0% +running integrator or an +ewma um uh which is an iterative uh + + align:start position:0% +ewma um uh which is an iterative uh + + + align:start position:0% +ewma um uh which is an iterative uh +discrete filter uh can be applied and I + + align:start position:0% +discrete filter uh can be applied and I + + + align:start position:0% +discrete filter uh can be applied and I +think conceptually uh they're fairly + + align:start position:0% +think conceptually uh they're fairly + + + align:start position:0% +think conceptually uh they're fairly +nice in terms of that noise suppression + + align:start position:0% +nice in terms of that noise suppression + + + align:start position:0% +nice in terms of that noise suppression +for detecting detecting of the mean got + + align:start position:0% +for detecting detecting of the mean got + + + align:start position:0% +for detecting detecting of the mean got +to remember that your choice of factors + + align:start position:0% +to remember that your choice of factors + + + align:start position:0% +to remember that your choice of factors +like R in the ewma depends on your + + align:start position:0% +like R in the ewma depends on your + + + align:start position:0% +like R in the ewma depends on your +process the mix of noise and how fast + + align:start position:0% +process the mix of noise and how fast + + + align:start position:0% +process the mix of noise and how fast +you want to respond to be able to detect + + align:start position:0% +you want to respond to be able to detect + + + align:start position:0% +you want to respond to be able to detect +a mean shift and then going back to what + + align:start position:0% +a mean shift and then going back to what + + + align:start position:0% +a mean shift and then going back to what +we started with our little example at + + align:start position:0% +we started with our little example at + + + align:start position:0% +we started with our little example at +the very + + align:start position:0% +the very + + + align:start position:0% +the very +beginning noisy data needs some + + align:start position:0% +beginning noisy data needs some + + + align:start position:0% +beginning noisy data needs some +filtering we've talked about it with + + align:start position:0% +filtering we've talked about it with + + + align:start position:0% +filtering we've talked about it with +respect to the mean but if I'm filtering + + align:start position:0% +respect to the mean but if I'm filtering + + + align:start position:0% +respect to the mean but if I'm filtering +that data you also still want to look + + align:start position:0% +that data you also still want to look + + + align:start position:0% +that data you also still want to look +back and monitor the variance as well so + + align:start position:0% +back and monitor the variance as well so + + + align:start position:0% +back and monitor the variance as well so +you can apply these charts also to + + align:start position:0% +you can apply these charts also to + + + align:start position:0% +you can apply these charts also to +moving uh sbar charts uh and so + + align:start position:0% +moving uh sbar charts uh and so + + + align:start position:0% +moving uh sbar charts uh and so +on so what I want to do next is move a + + align:start position:0% +on so what I want to do next is move a + + + align:start position:0% +on so what I want to do next is move a +little bit to multivariate process + + align:start position:0% +little bit to multivariate process + + + align:start position:0% +little bit to multivariate process +control control charting when I've got + + align:start position:0% +control control charting when I've got + + + align:start position:0% +control control charting when I've got +more than one parameter that I I may be + + align:start position:0% +more than one parameter that I I may be + + + align:start position:0% +more than one parameter that I I may be +monitoring on the unit process or on the + + align:start position:0% +monitoring on the unit process or on the + + + align:start position:0% +monitoring on the unit process or on the +product and what's really interesting + + align:start position:0% +product and what's really interesting + + + align:start position:0% +product and what's really interesting +here is there are essentially two + + align:start position:0% +here is there are essentially two + + + align:start position:0% +here is there are essentially two +classic + + align:start position:0% +classic + + + align:start position:0% +classic +mistakes that are made again and again + + align:start position:0% +mistakes that are made again and again + + + align:start position:0% +mistakes that are made again and again +and I want to give you a feel for those + + align:start position:0% +and I want to give you a feel for those + + + align:start position:0% +and I want to give you a feel for those +two mistakes and strategies for avoiding + + align:start position:0% +two mistakes and strategies for avoiding + + + align:start position:0% +two mistakes and strategies for avoiding +them + + align:start position:0% +them + + + align:start position:0% +them +okay one classic problem is you've got + + align:start position:0% +okay one classic problem is you've got + + + align:start position:0% +okay one classic problem is you've got +more than one parameter you're + + align:start position:0% +more than one parameter you're + + + align:start position:0% +more than one parameter you're +monitoring you implement more than one + + align:start position:0% +monitoring you implement more than one + + + align:start position:0% +monitoring you implement more than one +control + + align:start position:0% +control + + + align:start position:0% +control +chart right seems natural but the + + align:start position:0% +chart right seems natural but the + + + align:start position:0% +chart right seems natural but the +problem is you can get many many many + + align:start position:0% +problem is you can get many many many + + + align:start position:0% +problem is you can get many many many +more false + + align:start position:0% +more false + + + align:start position:0% +more false +alarms than you might have expected or + + align:start position:0% +alarms than you might have expected or + + + align:start position:0% +alarms than you might have expected or +or or or believed you were going to to + + align:start position:0% +or or or believed you were going to to + + + align:start position:0% +or or or believed you were going to to +get because you're just monitoring more + + align:start position:0% +get because you're just monitoring more + + + align:start position:0% +get because you're just monitoring more +parameters and so I want to talk a + + align:start position:0% +parameters and so I want to talk a + + + align:start position:0% +parameters and so I want to talk a +little bit about that that's even if + + align:start position:0% +little bit about that that's even if + + + align:start position:0% +little bit about that that's even if +there's no correlation between your + + align:start position:0% +there's no correlation between your + + + align:start position:0% +there's no correlation between your +parameters okay or especially if there's + + align:start position:0% +parameters okay or especially if there's + + + align:start position:0% +parameters okay or especially if there's +no correlation between your parameters + + align:start position:0% +no correlation between your parameters + + + align:start position:0% +no correlation between your parameters +you can get just by the fact that you're + + align:start position:0% +you can get just by the fact that you're + + + align:start position:0% +you can get just by the fact that you're +you're monitoring more than one thing + + align:start position:0% +you're monitoring more than one thing + + + align:start position:0% +you're monitoring more than one thing +you got to think about false alarm rate + + align:start position:0% +you got to think about false alarm rate + + + align:start position:0% +you got to think about false alarm rate +a little bit differently and then the + + align:start position:0% +a little bit differently and then the + + + align:start position:0% +a little bit differently and then the +second classic problem is well there is + + align:start position:0% +second classic problem is well there is + + + align:start position:0% +second classic problem is well there is +correlation among the + + align:start position:0% +correlation among the + + + align:start position:0% +correlation among the +parameters the multiple parameters how + + align:start position:0% +parameters the multiple parameters how + + + align:start position:0% +parameters the multiple parameters how +do you deal with that and in fact in + + align:start position:0% +do you deal with that and in fact in + + + align:start position:0% +do you deal with that and in fact in +this case you often run into the + + align:start position:0% +this case you often run into the + + + align:start position:0% +this case you often run into the +opposite + + align:start position:0% +opposite + + + align:start position:0% +opposite +risk instead of too many false alarms + + align:start position:0% +risk instead of too many false alarms + + + align:start position:0% +risk instead of too many false alarms +you may have have points of data or + + align:start position:0% +you may have have points of data or + + + align:start position:0% +you may have have points of data or +product that is truly out of out of + + align:start position:0% +product that is truly out of out of + + + align:start position:0% +product that is truly out of out of +normal operation that you may not detect + + align:start position:0% +normal operation that you may not detect + + + align:start position:0% +normal operation that you may not detect +it's a highly unusual point that may in + + align:start position:0% +it's a highly unusual point that may in + + + align:start position:0% +it's a highly unusual point that may in +indicate something has changed in your + + align:start position:0% +indicate something has changed in your + + + align:start position:0% +indicate something has changed in your +process but if you're just monitoring + + align:start position:0% +process but if you're just monitoring + + + align:start position:0% +process but if you're just monitoring +with univariate control charts you'll + + align:start position:0% +with univariate control charts you'll + + + align:start position:0% +with univariate control charts you'll +never see it okay and so I want to talk + + align:start position:0% +never see it okay and so I want to talk + + + align:start position:0% +never see it okay and so I want to talk +about that as a common mistake number + + align:start position:0% +about that as a common mistake number + + + align:start position:0% +about that as a common mistake number +two let me talk about multiple charts as + + align:start position:0% +two let me talk about multiple charts as + + + align:start position:0% +two let me talk about multiple charts as +common mistake number one first + + align:start position:0% +common mistake number one first + + + align:start position:0% +common mistake number one first +if I truly have independent parameters + + align:start position:0% +if I truly have independent parameters + + + align:start position:0% +if I truly have independent parameters +being modeled monitored at my process + + align:start position:0% +being modeled monitored at my process + + + align:start position:0% +being modeled monitored at my process +step and I set each one of them up to + + align:start position:0% +step and I set each one of them up to + + + align:start position:0% +step and I set each one of them up to +have some acceptable Alpha rate false + + align:start position:0% +have some acceptable Alpha rate false + + + align:start position:0% +have some acceptable Alpha rate false +alarm rate one out of every 370 process + + align:start position:0% +alarm rate one out of every 370 process + + + align:start position:0% +alarm rate one out of every 370 process +steps sort of going with a plusus 3 + + align:start position:0% + + + + align:start position:0% + +Sigma right three sigma control limits + + align:start position:0% +Sigma right three sigma control limits + + + align:start position:0% +Sigma right three sigma control limits +Alpha is about + + align:start position:0% +Alpha is about + + + align:start position:0% +Alpha is about +027 sometimes talked about 03 as an + + align:start position:0% +027 sometimes talked about 03 as an + + + align:start position:0% +027 sometimes talked about 03 as an +approximation + + align:start position:0% +approximation + + + align:start position:0% +approximation +but now I've got P of those separate + + align:start position:0% +but now I've got P of those separate + + + align:start position:0% +but now I've got P of those separate +charts what is the aggregate false alarm + + align:start position:0% +charts what is the aggregate false alarm + + + align:start position:0% +charts what is the aggregate false alarm +probability well to be careful about it + + align:start position:0% +probability well to be careful about it + + + align:start position:0% +probability well to be careful about it +if they are in fact independent that + + align:start position:0% +if they are in fact independent that + + + align:start position:0% +if they are in fact independent that +Alpha Prime my aggregate false alarm is + + align:start position:0% +Alpha Prime my aggregate false alarm is + + + align:start position:0% +Alpha Prime my aggregate false alarm is +1 minus 1 minus Alpha to the P right + + align:start position:0% +1 minus 1 minus Alpha to the P right + + + align:start position:0% +1 minus 1 minus Alpha to the P right +this is the + + align:start position:0% +this is the + + + align:start position:0% +this is the +probability um that I don't get a false + + align:start position:0% +probability um that I don't get a false + + + align:start position:0% +probability um that I don't get a false +alarm for each of for all of the other P + + align:start position:0% +alarm for each of for all of the other P + + + align:start position:0% +alarm for each of for all of the other P +control + + align:start position:0% +control + + + align:start position:0% +control +charts all at the same time and then + + align:start position:0% +charts all at the same time and then + + + align:start position:0% +charts all at the same time and then +oneus that is the chance that I did get + + align:start position:0% +oneus that is the chance that I did get + + + align:start position:0% +oneus that is the chance that I did get +one of them now for very small Alpha you + + align:start position:0% +one of them now for very small Alpha you + + + align:start position:0% +one of them now for very small Alpha you +do that expansion one minus X for small + + align:start position:0% +do that expansion one minus X for small + + + align:start position:0% +do that expansion one minus X for small +x to the p is simply 1 minus PX so you + + align:start position:0% +x to the p is simply 1 minus PX so you + + + align:start position:0% +x to the p is simply 1 minus PX so you +do that and you get sort of the nice + + align:start position:0% +do that and you get sort of the nice + + + align:start position:0% +do that and you get sort of the nice +intuitive result that if I've got 10 + + align:start position:0% +intuitive result that if I've got 10 + + + align:start position:0% +intuitive result that if I've got 10 +independent control charts I've got + + align:start position:0% +independent control charts I've got + + + align:start position:0% +independent control charts I've got +about 10 times the rate of false alarm + + align:start position:0% +about 10 times the rate of false alarm + + + align:start position:0% +about 10 times the rate of false alarm +that I would have from + + align:start position:0% + + + + align:start position:0% + +one so what do you do + + align:start position:0% + + + + align:start position:0% + +what would you + + align:start position:0% +what would you + + + align:start position:0% +what would you +do let me let me say it this way um + + align:start position:0% +do let me let me say it this way um + + + align:start position:0% +do let me let me say it this way um +you've decided based on your cost + + align:start position:0% +you've decided based on your cost + + + align:start position:0% +you've decided based on your cost +analysis or whatever that you're willing + + align:start position:0% +analysis or whatever that you're willing + + + align:start position:0% +analysis or whatever that you're willing +about once every + + align:start position:0% +about once every + + + align:start position:0% +about once every + + align:start position:0% + + + align:start position:0% +runs + + align:start position:0% +runs + + + align:start position:0% +runs +to have a false alarm somewhere on this + + align:start position:0% +to have a false alarm somewhere on this + + + align:start position:0% +to have a false alarm somewhere on this +process that you want to at least look + + align:start position:0% +process that you want to at least look + + + align:start position:0% +process that you want to at least look +at maybe you look at it real quickly it + + align:start position:0% +at maybe you look at it real quickly it + + + align:start position:0% +at maybe you look at it real quickly it +doesn't take a long time but but that's + + align:start position:0% +doesn't take a long time but but that's + + + align:start position:0% +doesn't take a long time but but that's +about how often you want the operator to + + align:start position:0% +about how often you want the operator to + + + align:start position:0% +about how often you want the operator to +stop and take a look on average even + + align:start position:0% +stop and take a look on average even + + + align:start position:0% +stop and take a look on average even +when the process is in control so that's + + align:start position:0% +when the process is in control so that's + + + align:start position:0% +when the process is in control so that's +your false alarm rate that you're + + align:start position:0% +your false alarm rate that you're + + + align:start position:0% +your false alarm rate that you're +willing to accept but you're monitoring + + align:start position:0% +willing to accept but you're monitoring + + + align:start position:0% +willing to accept but you're monitoring + + align:start position:0% + + + + align:start position:0% + +parameters there are some approaches you + + align:start position:0% +parameters there are some approaches you + + + align:start position:0% +parameters there are some approaches you +would + + align:start position:0% + + + + align:start position:0% + +use um you have to increase your control + + align:start position:0% +use um you have to increase your control + + + align:start position:0% +use um you have to increase your control +limits right perfect you would increase + + align:start position:0% +limits right perfect you would increase + + + align:start position:0% +limits right perfect you would increase +your control limits if I expand my + + align:start position:0% +your control limits if I expand my + + + align:start position:0% +your control limits if I expand my +control limits out a little bit I have + + align:start position:0% +control limits out a little bit I have + + + align:start position:0% +control limits out a little bit I have +smaller false alarm rate on each on each + + align:start position:0% +smaller false alarm rate on each on each + + + align:start position:0% +smaller false alarm rate on each on each +uh on each chart well I can basically + + align:start position:0% +uh on each chart well I can basically + + + align:start position:0% +uh on each chart well I can basically +decide what + + align:start position:0% +decide what + + + align:start position:0% +decide what +my + + align:start position:0% +my + + + align:start position:0% +my +um my + + align:start position:0% +um my + + + align:start position:0% +um my +aggregate false alarm rate would + + align:start position:0% +aggregate false alarm rate would + + + align:start position:0% +aggregate false alarm rate would +be 1 out of 370 and to set my false + + align:start position:0% +be 1 out of 370 and to set my false + + + align:start position:0% +be 1 out of 370 and to set my false +alarm rate on each individual chart just + + align:start position:0% +alarm rate on each individual chart just + + + align:start position:0% +alarm rate on each individual chart just +divide by how many charts I have now I + + align:start position:0% +divide by how many charts I have now I + + + align:start position:0% +divide by how many charts I have now I +might have a one in 300 + + align:start position:0% +might have a one in 300 + + + align:start position:0% +might have a one in 300 +3,700 false alarm rate on each chart and + + align:start position:0% +3,700 false alarm rate on each chart and + + + align:start position:0% +3,700 false alarm rate on each chart and +I use that new Alpha to set my control + + align:start position:0% +I use that new Alpha to set my control + + + align:start position:0% +I use that new Alpha to set my control +limits they might end up being in that + + align:start position:0% +limits they might end up being in that + + + align:start position:0% +limits they might end up being in that +case plusus 3.4 Sigma control + + align:start position:0% +case plusus 3.4 Sigma control + + + align:start position:0% +case plusus 3.4 Sigma control +limits okay so the individual uh false + + align:start position:0% +limits okay so the individual uh false + + + align:start position:0% +limits okay so the individual uh false +alarm rate + + align:start position:0% +alarm rate + + + align:start position:0% +alarm rate +is is lower on each one because really + + align:start position:0% +is is lower on each one because really + + + align:start position:0% +is is lower on each one because really +the question you were asking the key + + align:start position:0% +the question you were asking the key + + + align:start position:0% +the question you were asking the key +question was not you know that + + align:start position:0% +question was not you know that + + + align:start position:0% +question was not you know that +individual parameter one you know but + + align:start position:0% +individual parameter one you know but + + + align:start position:0% +individual parameter one you know but +rather the question is my process in + + align:start position:0% +rather the question is my process in + + + align:start position:0% +rather the question is my process in +control in aggregate do I have an event + + align:start position:0% +control in aggregate do I have an event + + + align:start position:0% +control in aggregate do I have an event +that looks + + align:start position:0% +that looks + + + align:start position:0% +that looks +unlikely so unlikely that I + + align:start position:0% +unlikely so unlikely that I + + + align:start position:0% +unlikely so unlikely that I +have oneus Alpha + + align:start position:0% +have oneus Alpha + + + align:start position:0% +have oneus Alpha +confidence oneus Alpha Prime confidence + + align:start position:0% +confidence oneus Alpha Prime confidence + + + align:start position:0% +confidence oneus Alpha Prime confidence +evence that in fact something unusual is + + align:start position:0% +evence that in fact something unusual is + + + align:start position:0% +evence that in fact something unusual is +going on in the process okay so that's + + align:start position:0% +going on in the process okay so that's + + + align:start position:0% +going on in the process okay so that's +the that's the strategy I want to also + + align:start position:0% +the that's the strategy I want to also + + + align:start position:0% +the that's the strategy I want to also +point out and this is kind of a a neat + + align:start position:0% +point out and this is kind of a a neat + + + align:start position:0% +point out and this is kind of a a neat +little article that I found uh uh last + + align:start position:0% +little article that I found uh uh last + + + align:start position:0% +little article that I found uh uh last +year that this is a more generic problem + + align:start position:0% +year that this is a more generic problem + + + align:start position:0% +year that this is a more generic problem +a more generic common mistake than just + + align:start position:0% +a more generic common mistake than just + + + align:start position:0% +a more generic common mistake than just +control charting it applies all the time + + align:start position:0% +control charting it applies all the time + + + align:start position:0% +control charting it applies all the time +when people are doing significance tests + + align:start position:0% +when people are doing significance tests + + + align:start position:0% +when people are doing significance tests +or hypothesis tests but doing more than + + align:start position:0% +or hypothesis tests but doing more than + + + align:start position:0% +or hypothesis tests but doing more than +one of them at a time + + align:start position:0% +one of them at a time + + + align:start position:0% +one of them at a time +time right control chart is just a + + align:start position:0% +time right control chart is just a + + + align:start position:0% +time right control chart is just a +running hypothesis test now if I'm + + align:start position:0% +running hypothesis test now if I'm + + + align:start position:0% +running hypothesis test now if I'm +checking 10 hypotheses 10 control charts + + align:start position:0% +checking 10 hypotheses 10 control charts + + + align:start position:0% +checking 10 hypotheses 10 control charts +and 10 + + align:start position:0% +and 10 + + + align:start position:0% +and 10 +parameters um my aggregate you know + + align:start position:0% +parameters um my aggregate you know + + + align:start position:0% +parameters um my aggregate you know +false alarm rate is is higher and + + align:start position:0% +false alarm rate is is higher and + + + align:start position:0% +false alarm rate is is higher and +there's this neat little article pulled + + align:start position:0% +there's this neat little article pulled + + + align:start position:0% +there's this neat little article pulled +from that I found in the economist uh + + align:start position:0% +from that I found in the economist uh + + + align:start position:0% +from that I found in the economist uh +last February that's called medical + + align:start position:0% +last February that's called medical + + + align:start position:0% +last February that's called medical +statistics signs of the times the + + align:start position:0% +statistics signs of the times the + + + align:start position:0% +statistics signs of the times the +subtitle here you may not be able to + + align:start position:0% +subtitle here you may not be able to + + + align:start position:0% +subtitle here you may not be able to +read it is why so much medical research + + align:start position:0% +read it is why so much medical research + + + align:start position:0% +read it is why so much medical research +is + + align:start position:0% +is + + + align:start position:0% +is +rot and uh the first I'll read you the + + align:start position:0% +rot and uh the first I'll read you the + + + align:start position:0% +rot and uh the first I'll read you the +first couple of sentences here people + + align:start position:0% +first couple of sentences here people + + + align:start position:0% +first couple of sentences here people +born under the astrological sign of Leo + + align:start position:0% +born under the astrological sign of Leo + + + align:start position:0% +born under the astrological sign of Leo +are 15% more likely to be admitted to + + align:start position:0% +are 15% more likely to be admitted to + + + align:start position:0% +are 15% more likely to be admitted to +hospital with gastric bleeding than + + align:start position:0% +hospital with gastric bleeding than + + + align:start position:0% +hospital with gastric bleeding than +those born with the other 11 signs + + align:start position:0% +those born with the other 11 signs + + + align:start position:0% +those born with the other 11 signs +sagittarians are 38% more likely than + + align:start position:0% +sagittarians are 38% more likely than + + + align:start position:0% +sagittarians are 38% more likely than +others to land up there because of a + + align:start position:0% +others to land up there because of a + + + align:start position:0% +others to land up there because of a +broken + + align:start position:0% +broken + + + align:start position:0% +broken +arm those are the conclusions that many + + align:start position:0% +arm those are the conclusions that many + + + align:start position:0% +arm those are the conclusions that many +medical researchers would be forced to + + align:start position:0% +medical researchers would be forced to + + + align:start position:0% +medical researchers would be forced to +make from a set of data presented to the + + align:start position:0% +make from a set of data presented to the + + + align:start position:0% +make from a set of data presented to the +American Association for the advancement + + align:start position:0% +American Association for the advancement + + + align:start position:0% +American Association for the advancement +of science um at least they would be + + align:start position:0% +of science um at least they would be + + + align:start position:0% +of science um at least they would be +forced to draw them if they applied the + + align:start position:0% +forced to draw them if they applied the + + + align:start position:0% +forced to draw them if they applied the +lack statistical methods of their own + + align:start position:0% +lack statistical methods of their own + + + align:start position:0% +lack statistical methods of their own +work to the records of Hospital + + align:start position:0% +work to the records of Hospital + + + align:start position:0% +work to the records of Hospital +admissions in Ontario + + align:start position:0% +admissions in Ontario + + + align:start position:0% +admissions in Ontario +Canada and the basic confusion drawn + + align:start position:0% +Canada and the basic confusion drawn + + + align:start position:0% +Canada and the basic confusion drawn +here in the in the red arises because + + align:start position:0% +here in the in the red arises because + + + align:start position:0% +here in the in the red arises because +each result is tested separately to see + + align:start position:0% +each result is tested separately to see + + + align:start position:0% +each result is tested separately to see +how likely in statistical terms it was + + align:start position:0% +how likely in statistical terms it was + + + align:start position:0% +how likely in statistical terms it was +to have happened by Chance the + + align:start position:0% +to have happened by Chance the + + + align:start position:0% +to have happened by Chance the +likelihood is below a certain threshold + + align:start position:0% +likelihood is below a certain threshold + + + align:start position:0% +likelihood is below a certain threshold +typically n uh 5% so we got a 95% + + align:start position:0% +typically n uh 5% so we got a 95% + + + align:start position:0% +typically n uh 5% so we got a 95% +confidence + + align:start position:0% +confidence + + + align:start position:0% +confidence +which says one in 20 times by chance + + align:start position:0% +which says one in 20 times by chance + + + align:start position:0% +which says one in 20 times by chance +alone I might see a signal that big by + + align:start position:0% +alone I might see a signal that big by + + + align:start position:0% +alone I might see a signal that big by +chance alone and now I check 12 maybe + + align:start position:0% +chance alone and now I check 12 maybe + + + align:start position:0% +chance alone and now I check 12 maybe +astrological sign is your 12 things I'm + + align:start position:0% +astrological sign is your 12 things I'm + + + align:start position:0% +astrological sign is your 12 things I'm +checking for as factors and I've got a + + align:start position:0% +checking for as factors and I've got a + + + align:start position:0% +checking for as factors and I've got a +one in 20 one in 20 chance and I check + + align:start position:0% +one in 20 one in 20 chance and I check + + + align:start position:0% +one in 20 one in 20 chance and I check +12 of them probably I'm going to pop up + + align:start position:0% +12 of them probably I'm going to pop up + + + align:start position:0% +12 of them probably I'm going to pop up +and say ah that one's + + align:start position:0% +and say ah that one's + + + align:start position:0% +and say ah that one's +significant right and so that's exactly + + align:start position:0% +significant right and so that's exactly + + + align:start position:0% +significant right and so that's exactly +the same common mistake that you can see + + align:start position:0% +the same common mistake that you can see + + + align:start position:0% +the same common mistake that you can see +with multiple control charts and so the + + align:start position:0% +with multiple control charts and so the + + + align:start position:0% +with multiple control charts and so the +point here would simply be you should if + + align:start position:0% +point here would simply be you should if + + + align:start position:0% +point here would simply be you should if +you're checking multiple factors you got + + align:start position:0% +you're checking multiple factors you got + + + align:start position:0% +you're checking multiple factors you got +to have a a stronger indication than any + + align:start position:0% +to have a a stronger indication than any + + + align:start position:0% +to have a a stronger indication than any +one factor otherwise you're just fishing + + align:start position:0% +one factor otherwise you're just fishing + + + align:start position:0% +one factor otherwise you're just fishing +and by chance alone you're going to find + + align:start position:0% +and by chance alone you're going to find + + + align:start position:0% +and by chance alone you're going to find +stuff okay so it's kind of a neat + + align:start position:0% +stuff okay so it's kind of a neat + + + align:start position:0% +stuff okay so it's kind of a neat +example and so here was the point I made + + align:start position:0% +example and so here was the point I made + + + align:start position:0% +example and so here was the point I made +about how you fix it you just fix your + + align:start position:0% +about how you fix it you just fix your + + + align:start position:0% +about how you fix it you just fix your +aggregate Alpha Prime you have your + + align:start position:0% +aggregate Alpha Prime you have your + + + align:start position:0% +aggregate Alpha Prime you have your +individual Alpha and then you pick your + + align:start position:0% +individual Alpha and then you pick your + + + align:start position:0% +individual Alpha and then you pick your +upper and lower control limits based on + + align:start position:0% +upper and lower control limits based on + + + align:start position:0% +upper and lower control limits based on +that Al + + align:start position:0% +that Al + + + align:start position:0% +that Al +Alpha there's a second common problem + + align:start position:0% +Alpha there's a second common problem + + + align:start position:0% +Alpha there's a second common problem +and and as I said it's the obverse of + + align:start position:0% +and and as I said it's the obverse of + + + align:start position:0% +and and as I said it's the obverse of +this which is you very often assume that + + align:start position:0% +this which is you very often assume that + + + align:start position:0% +this which is you very often assume that +if I'm monitoring 10 process control + + align:start position:0% +if I'm monitoring 10 process control + + + align:start position:0% +if I'm monitoring 10 process control +parameters I assume they're all + + align:start position:0% +parameters I assume they're all + + + align:start position:0% +parameters I assume they're all +independent but very often they are not + + align:start position:0% +independent but very often they are not + + + align:start position:0% +independent but very often they are not +there is correlation among those + + align:start position:0% +there is correlation among those + + + align:start position:0% +there is correlation among those +parameters and I want to give you a + + align:start position:0% +parameters and I want to give you a + + + align:start position:0% +parameters and I want to give you a +little bit of a feel for what that looks + + align:start position:0% +little bit of a feel for what that looks + + + align:start position:0% +little bit of a feel for what that looks +like and what the risk is and what + + align:start position:0% +like and what the risk is and what + + + align:start position:0% +like and what the risk is and what +approaches are for control charting in + + align:start position:0% +approaches are for control charting in + + + align:start position:0% +approaches are for control charting in +particular of this so here's an example + + align:start position:0% +particular of this so here's an example + + + align:start position:0% +particular of this so here's an example +drawn from some data that came from an + + align:start position:0% +drawn from some data that came from an + + + align:start position:0% +drawn from some data that came from an +lfm thesis a few years ago a body and + + align:start position:0% +lfm thesis a few years ago a body and + + + align:start position:0% +lfm thesis a few years ago a body and +white assembly so in body and white this + + align:start position:0% +white assembly so in body and white this + + + align:start position:0% +white assembly so in body and white this +is when they are basically uh putting + + align:start position:0% +is when they are basically uh putting + + + align:start position:0% +is when they are basically uh putting +together all of the different panels uh + + align:start position:0% +together all of the different panels uh + + + align:start position:0% +together all of the different panels uh +on the car and measuring uh many many + + align:start position:0% +on the car and measuring uh many many + + + align:start position:0% +on the car and measuring uh many many +points with all kinds of laser uh uh + + align:start position:0% +points with all kinds of laser uh uh + + + align:start position:0% +points with all kinds of laser uh uh +automated apparatus to be able to look + + align:start position:0% +automated apparatus to be able to look + + + align:start position:0% +automated apparatus to be able to look +at dimensional control of these panels + + align:start position:0% +at dimensional control of these panels + + + align:start position:0% +at dimensional control of these panels +in the assembly + + align:start position:0% +in the assembly + + + align:start position:0% +in the assembly +uh of some of these panels other + + align:start position:0% +uh of some of these panels other + + + align:start position:0% +uh of some of these panels other +correlated data comes up all over the + + align:start position:0% +correlated data comes up all over the + + + align:start position:0% +correlated data comes up all over the +place uh injection molding I think uh oh + + align:start position:0% +place uh injection molding I think uh oh + + + align:start position:0% +place uh injection molding I think uh oh +we're + + align:start position:0% +we're + + + align:start position:0% +we're +missing I can't remember his name he he + + align:start position:0% +missing I can't remember his name he he + + + align:start position:0% +missing I can't remember his name he he +asked a question last time about + + align:start position:0% +asked a question last time about + + + align:start position:0% +asked a question last time about +critical dimensions on a semiconductor + + align:start position:0% +critical dimensions on a semiconductor + + + align:start position:0% +critical dimensions on a semiconductor +wafer yes they are often correlated um + + align:start position:0% +wafer yes they are often correlated um + + + align:start position:0% +wafer yes they are often correlated um +but here's the body and white example + + align:start position:0% +but here's the body and white example + + + align:start position:0% +but here's the body and white example +and what I'm sort of showing are these + + align:start position:0% +and what I'm sort of showing are these + + + align:start position:0% +and what I'm sort of showing are these +little coordinate measuring machine uh + + align:start position:0% +little coordinate measuring machine uh + + + align:start position:0% +little coordinate measuring machine uh +CMM kinds of U measurements of a few of + + align:start position:0% +CMM kinds of U measurements of a few of + + + align:start position:0% +CMM kinds of U measurements of a few of +these uh different different data points + + align:start position:0% +these uh different different data points + + + align:start position:0% +these uh different different data points +points and the point is if I think of + + align:start position:0% +points and the point is if I think of + + + align:start position:0% +points and the point is if I think of +this as a metal panel in some way and + + align:start position:0% +this as a metal panel in some way and + + + align:start position:0% +this as a metal panel in some way and +I'm measuring the position say of these + + align:start position:0% +I'm measuring the position say of these + + + align:start position:0% +I'm measuring the position say of these +four corner + + align:start position:0% + + + + align:start position:0% + +points right you would expect there to + + align:start position:0% +points right you would expect there to + + + align:start position:0% +points right you would expect there to +be correlation among them and certain + + align:start position:0% +be correlation among them and certain + + + align:start position:0% +be correlation among them and certain +kinds of distortion might change + + align:start position:0% +kinds of distortion might change + + + align:start position:0% +kinds of distortion might change +relationships between them and in fact + + align:start position:0% +relationships between them and in fact + + + align:start position:0% +relationships between them and in fact +you might even come up with other + + align:start position:0% +you might even come up with other + + + align:start position:0% +you might even come up with other +statistics like a y1 and a Y3 and a y4 + + align:start position:0% +statistics like a y1 and a Y3 and a y4 + + + align:start position:0% +statistics like a y1 and a Y3 and a y4 +that try to DET detect or look at + + align:start position:0% +that try to DET detect or look at + + + align:start position:0% +that try to DET detect or look at +tracking of a couple of these parameters + + align:start position:0% +tracking of a couple of these parameters + + + align:start position:0% +tracking of a couple of these parameters +and deviations but the point is I + + align:start position:0% +and deviations but the point is I + + + align:start position:0% +and deviations but the point is I +wouldn't necessarily want to monitor + + align:start position:0% +wouldn't necessarily want to monitor + + + align:start position:0% +wouldn't necessarily want to monitor +those four corner locations as + + align:start position:0% +those four corner locations as + + + align:start position:0% +those four corner locations as +independent + + align:start position:0% + + + + align:start position:0% + +parameters here's another example this + + align:start position:0% +parameters here's another example this + + + align:start position:0% +parameters here's another example this +comes from an ultrasonic uh welding set + + align:start position:0% +comes from an ultrasonic uh welding set + + + align:start position:0% +comes from an ultrasonic uh welding set +of data and you may not be able to see + + align:start position:0% +of data and you may not be able to see + + + align:start position:0% +of data and you may not be able to see +this this is a wonderful correlation + + align:start position:0% +this this is a wonderful correlation + + + align:start position:0% +this this is a wonderful correlation +plot of three four five six seven eight + + align:start position:0% +plot of three four five six seven eight + + + align:start position:0% +plot of three four five six seven eight +10 different parameters against each + + align:start position:0% +10 different parameters against each + + + align:start position:0% +10 different parameters against each +other uh there's different things like + + align:start position:0% +other uh there's different things like + + + align:start position:0% +other uh there's different things like +P2 weld energy P2 Peak power these are + + align:start position:0% +P2 weld energy P2 Peak power these are + + + align:start position:0% +P2 weld energy P2 Peak power these are +simply Scatter Plots of data drawn from + + align:start position:0% +simply Scatter Plots of data drawn from + + + align:start position:0% +simply Scatter Plots of data drawn from +that process you can see some of these + + align:start position:0% +that process you can see some of these + + + align:start position:0% +that process you can see some of these +parameters if I track down that's total + + align:start position:0% +parameters if I track down that's total + + + align:start position:0% +parameters if I track down that's total +weld energy versus P2 weld + + align:start position:0% +weld energy versus P2 weld + + + align:start position:0% +weld energy versus P2 weld +energy just I don't even know what those + + align:start position:0% +energy just I don't even know what those + + + align:start position:0% +energy just I don't even know what those +things mean but they sure sound like + + align:start position:0% +things mean but they sure sound like + + + align:start position:0% +things mean but they sure sound like +they're going to be correlated don't + + align:start position:0% +they're going to be correlated don't + + + align:start position:0% +they're going to be correlated don't +they and sure enough there's extremely + + align:start position:0% +they and sure enough there's extremely + + + align:start position:0% +they and sure enough there's extremely +strong correlation in that data there's + + align:start position:0% +strong correlation in that data there's + + + align:start position:0% +strong correlation in that data there's +other cases where there's + + align:start position:0% +other cases where there's + + + align:start position:0% +other cases where there's +also fairly strong correlation so again + + align:start position:0% +also fairly strong correlation so again + + + align:start position:0% +also fairly strong correlation so again +these these kinds of correlated data + + align:start position:0% +these these kinds of correlated data + + + align:start position:0% +these these kinds of correlated data +where knowing something about one of the + + align:start position:0% +where knowing something about one of the + + + align:start position:0% +where knowing something about one of the +measurements tells you about the + + align:start position:0% +measurements tells you about the + + + align:start position:0% +measurements tells you about the +likelihood of the other + + align:start position:0% +likelihood of the other + + + align:start position:0% +likelihood of the other +measurement uh uh occur all the + + align:start position:0% +measurement uh uh occur all the + + + align:start position:0% +measurement uh uh occur all the +time so what if you have truly random + + align:start position:0% +time so what if you have truly random + + + align:start position:0% +time so what if you have truly random +independent variables what would a + + align:start position:0% +independent variables what would a + + + align:start position:0% +independent variables what would a +scatter plot look like and how do we go + + align:start position:0% +scatter plot look like and how do we go + + + align:start position:0% +scatter plot look like and how do we go +about setting the control limits that's + + align:start position:0% +about setting the control limits that's + + + align:start position:0% +about setting the control limits that's +pretty natural right so here's an + + align:start position:0% +pretty natural right so here's an + + + align:start position:0% +pretty natural right so here's an +example where we had X1 and X2 the + + align:start position:0% +example where we had X1 and X2 the + + + align:start position:0% +example where we had X1 and X2 the +scatter plot you know it kind of + + align:start position:0% +scatter plot you know it kind of + + + align:start position:0% +scatter plot you know it kind of +basically looks like a cloud of data and + + align:start position:0% +basically looks like a cloud of data and + + + align:start position:0% +basically looks like a cloud of data and +if I added more data you start to + + align:start position:0% +if I added more data you start to + + + align:start position:0% +if I added more data you start to +depending on the scaling if I were + + align:start position:0% +depending on the scaling if I were + + + align:start position:0% +depending on the scaling if I were +simply to draw uh say a a joint 95% + + align:start position:0% +simply to draw uh say a a joint 95% + + + align:start position:0% +simply to draw uh say a a joint 95% +confidence interval it's just kind of a + + align:start position:0% +confidence interval it's just kind of a + + + align:start position:0% +confidence interval it's just kind of a +cloud of data but there's + + align:start position:0% +cloud of data but there's + + + align:start position:0% +cloud of data but there's +no cross information between X1 and x2 + + align:start position:0% +no cross information between X1 and x2 + + + align:start position:0% +no cross information between X1 and x2 +in other words if I told you that X1 was + + align:start position:0% +in other words if I told you that X1 was + + + align:start position:0% +in other words if I told you that X1 was +right here the value of X1 was this + + align:start position:0% +right here the value of X1 was this + + + align:start position:0% +right here the value of X1 was this +value that really doesn't tell me very + + align:start position:0% +value that really doesn't tell me very + + + align:start position:0% +value that really doesn't tell me very +much about what value of X2 could be it + + align:start position:0% +much about what value of X2 could be it + + + align:start position:0% +much about what value of X2 could be it +it still + + align:start position:0% +it still + + + align:start position:0% +it still +Falls anywhere within its distribution + + align:start position:0% +Falls anywhere within its distribution + + + align:start position:0% +Falls anywhere within its distribution +these are two independent random + + align:start position:0% +these are two independent random + + + align:start position:0% +these are two independent random +variables and you can decide what the + + align:start position:0% +variables and you can decide what the + + + align:start position:0% +variables and you can decide what the +proper limits are now you know enough + + align:start position:0% +proper limits are now you know enough + + + align:start position:0% +proper limits are now you know enough +about picking X1 and X2 and I would do + + align:start position:0% +about picking X1 and X2 and I would do + + + align:start position:0% +about picking X1 and X2 and I would do +the alpha Prime idea to pick independent + + align:start position:0% +the alpha Prime idea to pick independent + + + align:start position:0% +the alpha Prime idea to pick independent +limits on those two + + align:start position:0% +limits on those two + + + align:start position:0% +limits on those two +cases this is an example scatter plot + + align:start position:0% +cases this is an example scatter plot + + + align:start position:0% +cases this is an example scatter plot +for correlated random variables in in + + align:start position:0% +for correlated random variables in in + + + align:start position:0% +for correlated random variables in in +this case you know it starts to look + + align:start position:0% +this case you know it starts to look + + + align:start position:0% +this case you know it starts to look +like an oval or a football kind of kind + + align:start position:0% +like an oval or a football kind of kind + + + align:start position:0% +like an oval or a football kind of kind +of shape where there is statistical + + align:start position:0% +of shape where there is statistical + + + align:start position:0% +of shape where there is statistical +correlation between these two parameters + + align:start position:0% +correlation between these two parameters + + + align:start position:0% +correlation between these two parameters +by which I mean if I tell you that X1 is + + align:start position:0% +by which I mean if I tell you that X1 is + + + align:start position:0% +by which I mean if I tell you that X1 is +in this range that tells you something + + align:start position:0% +in this range that tells you something + + + align:start position:0% +in this range that tells you something +about where the value of X2 is likely to + + align:start position:0% +about where the value of X2 is likely to + + + align:start position:0% +about where the value of X2 is likely to +fall it might not fall within its full + + align:start position:0% +fall it might not fall within its full + + + align:start position:0% +fall it might not fall within its full +natural range there is cross information + + align:start position:0% +natural range there is cross information + + + align:start position:0% +natural range there is cross information +or cross correlation between the two now + + align:start position:0% +or cross correlation between the two now + + + align:start position:0% +or cross correlation between the two now +if I were to plot X1 and X2 + + align:start position:0% +if I were to plot X1 and X2 + + + align:start position:0% +if I were to plot X1 and X2 +separately it looks an awful lot like + + align:start position:0% +separately it looks an awful lot like + + + align:start position:0% +separately it looks an awful lot like +the uncorrelated case so if I had + + align:start position:0% +the uncorrelated case so if I had + + + align:start position:0% +the uncorrelated case so if I had +independent control charts for the two + + align:start position:0% +independent control charts for the two + + + align:start position:0% +independent control charts for the two +the two variables essentially what I'm + + align:start position:0% +the two variables essentially what I'm + + + align:start position:0% +the two variables essentially what I'm +doing is just + + align:start position:0% +doing is just + + + align:start position:0% +doing is just +projecting all of these data points I + + align:start position:0% +projecting all of these data points I + + + align:start position:0% +projecting all of these data points I +project all of these data points to get + + align:start position:0% +project all of these data points to get + + + align:start position:0% +project all of these data points to get +my range for X2 and I project all of + + align:start position:0% +my range for X2 and I project all of + + + align:start position:0% +my range for X2 and I project all of +these data points and in fact if I plot + + align:start position:0% +these data points and in fact if I plot + + + align:start position:0% +these data points and in fact if I plot +both of those X1 and X2 + + align:start position:0% +both of those X1 and X2 + + + align:start position:0% +both of those X1 and X2 +I would likely get yikes want to do that + + align:start position:0% +I would likely get yikes want to do that + + + align:start position:0% +I would likely get yikes want to do that +I would likely get two + + align:start position:0% +I would likely get two + + + align:start position:0% +I would likely get two +separate normally distributed variables + + align:start position:0% +separate normally distributed variables + + + align:start position:0% +separate normally distributed variables +and I might be inclined to Simply plot + + align:start position:0% +and I might be inclined to Simply plot + + + align:start position:0% +and I might be inclined to Simply plot +them both + + align:start position:0% +them both + + + align:start position:0% +them both +as + + align:start position:0% +as + + + align:start position:0% +as +xbar uh and S kinds of control + + align:start position:0% +xbar uh and S kinds of control + + + align:start position:0% +xbar uh and S kinds of control +charts the risk + + align:start position:0% +charts the risk + + + align:start position:0% +charts the risk +here though when you do that is you + + align:start position:0% +here though when you do that is you + + + align:start position:0% +here though when you do that is you +might miss outliers + + align:start position:0% +might miss outliers + + + align:start position:0% +might miss outliers +data points that do not fall in the nor + + align:start position:0% +data points that do not fall in the nor + + + align:start position:0% +data points that do not fall in the nor +in the normal or the natural variation + + align:start position:0% +in the normal or the natural variation + + + align:start position:0% +in the normal or the natural variation +of the process this being the natural + + align:start position:0% +of the process this being the natural + + + align:start position:0% +of the process this being the natural +variation of the process that I will not + + align:start position:0% +variation of the process that I will not + + + align:start position:0% +variation of the process that I will not +detect right this data point still looks + + align:start position:0% +detect right this data point still looks + + + align:start position:0% +detect right this data point still looks +like it's within that distribution in + + align:start position:0% +like it's within that distribution in + + + align:start position:0% +like it's within that distribution in +fact it's very close to the mean of + + align:start position:0% +fact it's very close to the mean of + + + align:start position:0% +fact it's very close to the mean of +X2 and it's still within this + + align:start position:0% +X2 and it's still within this + + + align:start position:0% +X2 and it's still within this +distribution but within the natural + + align:start position:0% +distribution but within the natural + + + align:start position:0% +distribution but within the natural +variation of the process within that + + align:start position:0% +variation of the process within that + + + align:start position:0% +variation of the process within that +oval its + + align:start position:0% +oval its + + + align:start position:0% +oval its +distance in some sense from the from the + + align:start position:0% +distance in some sense from the from the + + + align:start position:0% +distance in some sense from the from the +central moments of that of that + + align:start position:0% +central moments of that of that + + + align:start position:0% +central moments of that of that +distribution it's pretty distant it's + + align:start position:0% +distribution it's pretty distant it's + + + align:start position:0% +distribution it's pretty distant it's +not indicative of the normal operation + + align:start position:0% +not indicative of the normal operation + + + align:start position:0% +not indicative of the normal operation +it's a highly unlikely by chance alone + + align:start position:0% +it's a highly unlikely by chance alone + + + align:start position:0% +it's a highly unlikely by chance alone +data point and I would never see it on + + align:start position:0% +data point and I would never see it on + + + align:start position:0% +data point and I would never see it on +the control + + align:start position:0% +the control + + + align:start position:0% +the control +chart so there are multivariate + + align:start position:0% +chart so there are multivariate + + + align:start position:0% +chart so there are multivariate +charts + + align:start position:0% +charts + + + align:start position:0% +charts +that let us get at and chart on the + + align:start position:0% +that let us get at and chart on the + + + align:start position:0% +that let us get at and chart on the +single + + align:start position:0% +single + + + align:start position:0% +single +chart multiple + + align:start position:0% +chart multiple + + + align:start position:0% +chart multiple +factors that are correlated together and + + align:start position:0% +factors that are correlated together and + + + align:start position:0% +factors that are correlated together and +detect those kinds of kinds of uh + + align:start position:0% +detect those kinds of kinds of uh + + + align:start position:0% +detect those kinds of kinds of uh +problems what I want to give you is a + + align:start position:0% +problems what I want to give you is a + + + align:start position:0% +problems what I want to give you is a +notion first of a + + align:start position:0% +notion first of a + + + align:start position:0% +notion first of a +statistic that Aggregates in some sense + + align:start position:0% +statistic that Aggregates in some sense + + + align:start position:0% +statistic that Aggregates in some sense +uh numerically Aggregates exactly what I + + align:start position:0% +uh numerically Aggregates exactly what I + + + align:start position:0% +uh numerically Aggregates exactly what I +was talking about qualitatively here + + align:start position:0% +was talking about qualitatively here + + + align:start position:0% +was talking about qualitatively here +that tells you this notion of what is + + align:start position:0% +that tells you this notion of what is + + + align:start position:0% +that tells you this notion of what is +the distance from the + + align:start position:0% +the distance from the + + + align:start position:0% +the distance from the +correlated variation cloud of each of my + + align:start position:0% +correlated variation cloud of each of my + + + align:start position:0% +correlated variation cloud of each of my +measurement points and if I have a + + align:start position:0% +measurement points and if I have a + + + align:start position:0% +measurement points and if I have a +statistic and I know it's + + align:start position:0% +statistic and I know it's + + + align:start position:0% +statistic and I know it's +PDF then I can set control limits on + + align:start position:0% +PDF then I can set control limits on + + + align:start position:0% +PDF then I can set control limits on +that statistic and that statistic is the + + align:start position:0% +that statistic and that statistic is the + + + align:start position:0% +that statistic and that statistic is the +hoteling t^2 is is one very important + + align:start position:0% +hoteling t^2 is is one very important + + + align:start position:0% +hoteling t^2 is is one very important +one we can also monitor uh + + align:start position:0% +one we can also monitor uh + + + align:start position:0% +one we can also monitor uh +um have ewma and Q some extensions of + + align:start position:0% +um have ewma and Q some extensions of + + + align:start position:0% +um have ewma and Q some extensions of +these which I'm not really going to talk + + align:start position:0% +these which I'm not really going to talk + + + align:start position:0% +these which I'm not really going to talk +much + + align:start position:0% +much + + + align:start position:0% +much +about so what we have to do here is have + + align:start position:0% +about so what we have to do here is have + + + align:start position:0% +about so what we have to do here is have +a slight extension to our notion of a + + align:start position:0% +a slight extension to our notion of a + + + align:start position:0% +a slight extension to our notion of a +probability density function to have + + align:start position:0% +probability density function to have + + + align:start position:0% +probability density function to have +joint probability density functions that + + align:start position:0% +joint probability density functions that + + + align:start position:0% +joint probability density functions that +tell me if I've got say two variables or + + align:start position:0% +tell me if I've got say two variables or + + + align:start position:0% +tell me if I've got say two variables or +three or four or whatever what is the + + align:start position:0% +three or four or whatever what is the + + + align:start position:0% +three or four or whatever what is the +probability density associated with + + align:start position:0% +probability density associated with + + + align:start position:0% +probability density associated with +those and what we want is a single scale + + align:start position:0% +those and what we want is a single scale + + + align:start position:0% +those and what we want is a single scale +control chart that Aggregates + + align:start position:0% +control chart that Aggregates + + + align:start position:0% +control chart that Aggregates +these now I've got uh a little bit of + + align:start position:0% +these now I've got uh a little bit of + + + align:start position:0% +these now I've got uh a little bit of +mathematical notation in here that uh + + align:start position:0% +mathematical notation in here that uh + + + align:start position:0% +mathematical notation in here that uh +I'm not going to go through the careful + + align:start position:0% +I'm not going to go through the careful + + + align:start position:0% +I'm not going to go through the careful +full explanation derivation of what I + + align:start position:0% +full explanation derivation of what I + + + align:start position:0% +full explanation derivation of what I +want to Simply show you is how a + + align:start position:0% +want to Simply show you is how a + + + align:start position:0% +want to Simply show you is how a +multivariate expression of the same + + align:start position:0% +multivariate expression of the same + + + align:start position:0% +multivariate expression of the same +variables we've been using all along + + align:start position:0% +variables we've been using all along + + + align:start position:0% +variables we've been using all along +gives you a nice qualitative feel for + + align:start position:0% +gives you a nice qualitative feel for + + + align:start position:0% +gives you a nice qualitative feel for +what this statistic looks like so if we + + align:start position:0% +what this statistic looks like so if we + + + align:start position:0% +what this statistic looks like so if we +have a vector of measurements let's say + + align:start position:0% +have a vector of measurements let's say + + + align:start position:0% +have a vector of measurements let's say +I have P parameters I'm measuring 10 + + align:start position:0% +I have P parameters I'm measuring 10 + + + align:start position:0% +I have P parameters I'm measuring 10 +different parameters body and white or + + align:start position:0% +different parameters body and white or + + + align:start position:0% +different parameters body and white or +or or whatever it is for for for that + + align:start position:0% +or or whatever it is for for for that + + + align:start position:0% +or or whatever it is for for for that +particular process and put those in an X + + align:start position:0% +particular process and put those in an X + + + align:start position:0% +particular process and put those in an X +underscore an X X vector and then I can + + align:start position:0% +underscore an X X vector and then I can + + + align:start position:0% +underscore an X X vector and then I can +define a vector of means so I have a set + + align:start position:0% +define a vector of means so I have a set + + + align:start position:0% +define a vector of means so I have a set +of means for all 10 parameters and I can + + align:start position:0% +of means for all 10 parameters and I can + + + align:start position:0% +of means for all 10 parameters and I can +also + + align:start position:0% +also + + + align:start position:0% +also +calculate if I have lots and lots of + + align:start position:0% +calculate if I have lots and lots of + + + align:start position:0% +calculate if I have lots and lots of +historical data there is an a true + + align:start position:0% +historical data there is an a true + + + align:start position:0% +historical data there is an a true +underlying covariance Matrix that talks + + align:start position:0% +underlying covariance Matrix that talks + + + align:start position:0% +underlying covariance Matrix that talks +about or characterizes how these data go + + align:start position:0% +about or characterizes how these data go + + + align:start position:0% +about or characterizes how these data go +together with each other now I can + + align:start position:0% +together with each other now I can + + + align:start position:0% +together with each other now I can +estimate that covariance Matrix based on + + align:start position:0% +estimate that covariance Matrix based on + + + align:start position:0% +estimate that covariance Matrix based on +Sample data so I similarly have a true + + align:start position:0% +Sample data so I similarly have a true + + + align:start position:0% +Sample data so I similarly have a true +mean and a true covariance that I might + + align:start position:0% +mean and a true covariance that I might + + + align:start position:0% +mean and a true covariance that I might +estimate with an + + align:start position:0% +estimate with an + + + align:start position:0% +estimate with an +xbar and an S here I'm using a capital S + + align:start position:0% +xbar and an S here I'm using a capital S + + + align:start position:0% +xbar and an S here I'm using a capital S +to be a sample covariance Matrix and + + align:start position:0% +to be a sample covariance Matrix and + + + align:start position:0% +to be a sample covariance Matrix and +there are formulas in the in the book + + align:start position:0% +there are formulas in the in the book + + + align:start position:0% +there are formulas in the in the book +using a very you know simple uh linear + + align:start position:0% +using a very you know simple uh linear + + + align:start position:0% +using a very you know simple uh linear +Matrix uh linear algebra for for how you + + align:start position:0% +Matrix uh linear algebra for for how you + + + align:start position:0% +Matrix uh linear algebra for for how you +would do that given a a particular set + + align:start position:0% +would do that given a a particular set + + + align:start position:0% +would do that given a a particular set +of + + align:start position:0% +of + + + align:start position:0% +of +data they look a lot like sort of the + + align:start position:0% +data they look a lot like sort of the + + + align:start position:0% +data they look a lot like sort of the +univariate + + align:start position:0% +univariate + + + align:start position:0% +univariate +example but I did want to point out that + + align:start position:0% +example but I did want to point out that + + + align:start position:0% +example but I did want to point out that +there's both embedded in this the notion + + align:start position:0% +there's both embedded in this the notion + + + align:start position:0% +there's both embedded in this the notion +of variance how variable two varies + + align:start position:0% +of variance how variable two varies + + + align:start position:0% +of variance how variable two varies +together with variable two that's sort + + align:start position:0% +together with variable two that's sort + + + align:start position:0% +together with variable two that's sort +of just our normal notion of variance + + align:start position:0% +of just our normal notion of variance + + + align:start position:0% +of just our normal notion of variance +and there's also co-variance that is a + + align:start position:0% +and there's also co-variance that is a + + + align:start position:0% +and there's also co-variance that is a +measure of how these two variables move + + align:start position:0% +measure of how these two variables move + + + align:start position:0% +measure of how these two variables move +together we can actually write out and + + align:start position:0% +together we can actually write out and + + + align:start position:0% +together we can actually write out and +what the uh PDF + + align:start position:0% +what the uh PDF + + + align:start position:0% +what the uh PDF +probability density functions are in + + align:start position:0% +probability density functions are in + + + align:start position:0% +probability density functions are in +these joint cases and if you write it in + + align:start position:0% +these joint cases and if you write it in + + + align:start position:0% +these joint cases and if you write it in +Matrix form using this covariance Matrix + + align:start position:0% +Matrix form using this covariance Matrix + + + align:start position:0% +Matrix form using this covariance Matrix +and the MU + + align:start position:0% +and the MU + + + align:start position:0% +and the MU +Vector it looks almost exactly the same + + align:start position:0% +Vector it looks almost exactly the same + + + align:start position:0% +Vector it looks almost exactly the same +as the univariate case notice that + + align:start position:0% +as the univariate case notice that + + + align:start position:0% +as the univariate case notice that +instead of variance in the univariant + + align:start position:0% +instead of variance in the univariant + + + align:start position:0% +instead of variance in the univariant +case now we have the + + align:start position:0% +case now we have the + + + align:start position:0% +case now we have the +co-variance oops The covariance Matrix + + align:start position:0% +co-variance oops The covariance Matrix + + + align:start position:0% +co-variance oops The covariance Matrix +right and + + align:start position:0% +right and + + + align:start position:0% +right and +similarly instead of you know just X and + + align:start position:0% +similarly instead of you know just X and + + + align:start position:0% +similarly instead of you know just X and +U being univariate values I've got those + + align:start position:0% +U being univariate values I've got those + + + align:start position:0% +U being univariate values I've got those +as + + align:start position:0% +as + + + align:start position:0% +as +vectors but the + + align:start position:0% +vectors but the + + + align:start position:0% +vectors but the +PDF looks almost exactly the + + align:start position:0% +PDF looks almost exactly the + + + align:start position:0% +PDF looks almost exactly the +same and qualitatively you're + + align:start position:0% +same and qualitatively you're + + + align:start position:0% +same and qualitatively you're +getting an + + align:start position:0% +getting an + + + align:start position:0% +getting an +exponential drop off this e drop off + + align:start position:0% +exponential drop off this e drop off + + + align:start position:0% +exponential drop off this e drop off +with the square of the distance of a + + align:start position:0% +with the square of the distance of a + + + align:start position:0% +with the square of the distance of a +point from the mean right the normalized + + align:start position:0% +point from the mean right the normalized + + + align:start position:0% +point from the mean right the normalized +distance from the point so if we look + + align:start position:0% +distance from the point so if we look + + + align:start position:0% +distance from the point so if we look +back at the univariate the whole idea is + + align:start position:0% +back at the univariate the whole idea is + + + align:start position:0% +back at the univariate the whole idea is +I subtract off the mean when I + + align:start position:0% +I subtract off the mean when I + + + align:start position:0% +I subtract off the mean when I +standardize divide by the natural + + align:start position:0% +standardize divide by the natural + + + align:start position:0% +standardize divide by the natural +variation and that tells me the shape of + + align:start position:0% +variation and that tells me the shape of + + + align:start position:0% +variation and that tells me the shape of +the bell curve shape of the normal curve + + align:start position:0% +the bell curve shape of the normal curve + + + align:start position:0% +the bell curve shape of the normal curve +how fast things drop off and I can also + + align:start position:0% +how fast things drop off and I can also + + + align:start position:0% +how fast things drop off and I can also +for any particular multivariate U + + align:start position:0% +for any particular multivariate U + + + align:start position:0% +for any particular multivariate U +multivariate data point x that has you + + align:start position:0% +multivariate data point x that has you + + + align:start position:0% +multivariate data point x that has you +know its 10 parameters in it what's + + align:start position:0% +know its 10 parameters in it what's + + + align:start position:0% +know its 10 parameters in it what's +really cool is this formulation here of + + align:start position:0% +really cool is this formulation here of + + + align:start position:0% +really cool is this formulation here of +the distance of that X vector from the + + align:start position:0% +the distance of that X vector from the + + + align:start position:0% +the distance of that X vector from the +mean point the mean + + align:start position:0% +mean point the mean + + + align:start position:0% +mean point the mean +Vector squared that squared distance but + + align:start position:0% +Vector squared that squared distance but + + + align:start position:0% +Vector squared that squared distance but +weighted then or normalized to the + + align:start position:0% +weighted then or normalized to the + + + align:start position:0% +weighted then or normalized to the +Natural spread that natural spread or + + align:start position:0% +Natural spread that natural spread or + + + align:start position:0% +Natural spread that natural spread or +width of that cloud is just a distance + + align:start position:0% +width of that cloud is just a distance + + + align:start position:0% +width of that cloud is just a distance +measure a squared distance measure of + + align:start position:0% +measure a squared distance measure of + + + align:start position:0% +measure a squared distance measure of +each data point from the central moment + + align:start position:0% +each data point from the central moment + + + align:start position:0% +each data point from the central moment +of the central point of the distribution + + align:start position:0% +of the central point of the distribution + + + align:start position:0% +of the central point of the distribution +scaled to how much natural spread or + + align:start position:0% +scaled to how much natural spread or + + + align:start position:0% +scaled to how much natural spread or +scatter there is in the data + + align:start position:0% +scatter there is in the data + + + align:start position:0% +scatter there is in the data +okay so that's the PDF and now I can go + + align:start position:0% +okay so that's the PDF and now I can go + + + align:start position:0% +okay so that's the PDF and now I can go +in those are just the formulas for the + + align:start position:0% +in those are just the formulas for the + + + align:start position:0% +in those are just the formulas for the +samples in these cases what I can now go + + align:start position:0% +samples in these cases what I can now go + + + align:start position:0% +samples in these cases what I can now go +in and do + + align:start position:0% +in and do + + + align:start position:0% +in and do +is ask the question what is + + align:start position:0% +is ask the question what is + + + align:start position:0% +is ask the question what is +the distribution associated with that + + align:start position:0% +the distribution associated with that + + + align:start position:0% +the distribution associated with that +distance + + align:start position:0% +distance + + + align:start position:0% +distance +metric and that distance metric is + + align:start position:0% +metric and that distance metric is + + + align:start position:0% +metric and that distance metric is +essentially if I expand out um that + + align:start position:0% +essentially if I expand out um that + + + align:start position:0% +essentially if I expand out um that +distance + + align:start position:0% +distance + + + align:start position:0% +distance +formula it is a sum of squared distances + + align:start position:0% +formula it is a sum of squared distances + + + align:start position:0% +formula it is a sum of squared distances +normalized to to the uh the + + align:start position:0% +normalized to to the uh the + + + align:start position:0% +normalized to to the uh the +correlation which starts to sound like + + align:start position:0% +correlation which starts to sound like + + + align:start position:0% +correlation which starts to sound like +sum of + + align:start position:0% +sum of + + + align:start position:0% +sum of +squared unit normal + + align:start position:0% +squared unit normal + + + align:start position:0% +squared unit normal +variables which was our Ki squar + + align:start position:0% +variables which was our Ki squar + + + align:start position:0% +variables which was our Ki squar +distribution sum of squared + + align:start position:0% +distribution sum of squared + + + align:start position:0% +distribution sum of squared +normal so what's cool here is that the + + align:start position:0% +normal so what's cool here is that the + + + align:start position:0% +normal so what's cool here is that the +Ki squar + + align:start position:0% +Ki squar + + + align:start position:0% +Ki squar +distribution with P parameters P degrees + + align:start position:0% +distribution with P parameters P degrees + + + align:start position:0% +distribution with P parameters P degrees +of fre freedom is the right statistic + + align:start position:0% +of fre freedom is the right statistic + + + align:start position:0% +of fre freedom is the right statistic +for measuring How likely it is to see + + align:start position:0% +for measuring How likely it is to see + + + align:start position:0% +for measuring How likely it is to see +those distance that t^2 those distance + + align:start position:0% +those distance that t^2 those distance + + + align:start position:0% +those distance that t^2 those distance +metrics okay so one can actually have + + align:start position:0% +metrics okay so one can actually have + + + align:start position:0% +metrics okay so one can actually have +the PDF one can have the distribution + + align:start position:0% +the PDF one can have the distribution + + + align:start position:0% +the PDF one can have the distribution +for that PDF and based on that you can + + align:start position:0% +for that PDF and based on that you can + + + align:start position:0% +for that PDF and based on that you can +formulate or form a that statistic based + + align:start position:0% +formulate or form a that statistic based + + + align:start position:0% +formulate or form a that statistic based +on my actual data X and then I can have + + align:start position:0% +on my actual data X and then I can have + + + align:start position:0% +on my actual data X and then I can have +Alpha squared that I can pick my cut off + + align:start position:0% +Alpha squared that I can pick my cut off + + + align:start position:0% +Alpha squared that I can pick my cut off +points from appropriately oops I thought + + align:start position:0% +points from appropriately oops I thought + + + align:start position:0% +points from appropriately oops I thought +I had a PDF in here somewhere yeah well + + align:start position:0% +I had a PDF in here somewhere yeah well + + + align:start position:0% +I had a PDF in here somewhere yeah well +so when + + align:start position:0% +so when + + + align:start position:0% +so when +I'm making a control chart I use the + + align:start position:0% +I'm making a control chart I use the + + + align:start position:0% +I'm making a control chart I use the +same ideas that we saw before I have a + + align:start position:0% +same ideas that we saw before I have a + + + align:start position:0% +same ideas that we saw before I have a +false alarm rate in this case I'm going + + align:start position:0% +false alarm rate in this case I'm going + + + align:start position:0% +false alarm rate in this case I'm going +to aggregate all my data onto a single + + align:start position:0% +to aggregate all my data onto a single + + + align:start position:0% +to aggregate all my data onto a single +control chart so I can just use my + + align:start position:0% +control chart so I can just use my + + + align:start position:0% +control chart so I can just use my +aggregate Alpha and I pick the uh tail + + align:start position:0% +aggregate Alpha and I pick the uh tail + + + align:start position:0% +aggregate Alpha and I pick the uh tail +points on the kais squ distribution + + align:start position:0% +points on the kais squ distribution + + + align:start position:0% +points on the kais squ distribution +remember a Kai squar might have looked + + align:start position:0% +remember a Kai squar might have looked + + + align:start position:0% +remember a Kai squar might have looked +something like this and I might pick way + + align:start position:0% +something like this and I might pick way + + + align:start position:0% +something like this and I might pick way +out here as my Kai + + align:start position:0% +out here as my Kai + + + align:start position:0% +out here as my Kai +squar so that I've got my Alpha out + + align:start position:0% +squar so that I've got my Alpha out + + + align:start position:0% +squar so that I've got my Alpha out +there in the tail that picks my my cut + + align:start position:0% +there in the tail that picks my my cut + + + align:start position:0% +there in the tail that picks my my cut +off point for my upper control + + align:start position:0% +off point for my upper control + + + align:start position:0% +off point for my upper control +limit um + + align:start position:0% +limit um + + + align:start position:0% +limit um +generally uh you you can also do that + + align:start position:0% +generally uh you you can also do that + + + align:start position:0% +generally uh you you can also do that +for a lower control limit very often if + + align:start position:0% +for a lower control limit very often if + + + align:start position:0% +for a lower control limit very often if +you do some apply some of these formulas + + align:start position:0% +you do some apply some of these formulas + + + align:start position:0% +you do some apply some of these formulas +the lower control limit is is negative + + align:start position:0% +the lower control limit is is negative + + + align:start position:0% +the lower control limit is is negative +and you can't have negative squares so + + align:start position:0% +and you can't have negative squares so + + + align:start position:0% +and you can't have negative squares so +you pick zero as your your lower control + + align:start position:0% +you pick zero as your your lower control + + + align:start position:0% +you pick zero as your your lower control +limit and you're really only monitoring + + align:start position:0% +limit and you're really only monitoring + + + align:start position:0% +limit and you're really only monitoring +for data points that + + align:start position:0% +for data points that + + + align:start position:0% +for data points that +are larger than I've got more variation + + align:start position:0% +are larger than I've got more variation + + + align:start position:0% +are larger than I've got more variation +uh in my system than I + + align:start position:0% +uh in my system than I + + + align:start position:0% +uh in my system than I +expected so just to sort of close up on + + align:start position:0% +expected so just to sort of close up on + + + align:start position:0% +expected so just to sort of close up on +on this sort of univariate versus Ki + + align:start position:0% +on this sort of univariate versus Ki + + + align:start position:0% +on this sort of univariate versus Ki +squar + + align:start position:0% +squar + + + align:start position:0% +squar +chart here's an example sort of + + align:start position:0% +chart here's an example sort of + + + align:start position:0% +chart here's an example sort of +comparing the univariate case up here to + + align:start position:0% +comparing the univariate case up here to + + + align:start position:0% +comparing the univariate case up here to +the multivariate case down here and what + + align:start position:0% +the multivariate case down here and what + + + align:start position:0% +the multivariate case down here and what +I'm plotting here is again the scatter + + align:start position:0% +I'm plotting here is again the scatter + + + align:start position:0% +I'm plotting here is again the scatter +of + + align:start position:0% +of + + + align:start position:0% +of +data you might see there's a slight + + align:start position:0% +data you might see there's a slight + + + align:start position:0% +data you might see there's a slight +shaded oval case and all the blue data + + align:start position:0% +shaded oval case and all the blue data + + + align:start position:0% +shaded oval case and all the blue data +points are what I would do if I just + + align:start position:0% +points are what I would do if I just + + + align:start position:0% +points are what I would do if I just +projected those down to an X1 and X2 and + + align:start position:0% +projected those down to an X1 and X2 and + + + align:start position:0% +projected those down to an X1 and X2 and +did univariate control charting if I + + align:start position:0% +did univariate control charting if I + + + align:start position:0% +did univariate control charting if I +then had this little red dot + + align:start position:0% +then had this little red dot + + + align:start position:0% +then had this little red dot +that fell outside of the joint um + + align:start position:0% +that fell outside of the joint um + + + align:start position:0% +that fell outside of the joint um +confidence interval on my individual + + align:start position:0% +confidence interval on my individual + + + align:start position:0% +confidence interval on my individual +charts notice where it falls perfectly + + align:start position:0% +charts notice where it falls perfectly + + + align:start position:0% +charts notice where it falls perfectly +within the control limits nothing that + + align:start position:0% +within the control limits nothing that + + + align:start position:0% +within the control limits nothing that +tells me that that point is + + align:start position:0% +tells me that that point is + + + align:start position:0% +tells me that that point is +unusual but if I then plot that data + + align:start position:0% +unusual but if I then plot that data + + + align:start position:0% +unusual but if I then plot that data +point that red data point there uh on + + align:start position:0% +point that red data point there uh on + + + align:start position:0% +point that red data point there uh on +the kai squared chart I calculated the + + align:start position:0% +the kai squared chart I calculated the + + + align:start position:0% +the kai squared chart I calculated the +kai statistic that distance statistic + + align:start position:0% +kai statistic that distance statistic + + + align:start position:0% +kai statistic that distance statistic +that would trigger because its + + align:start position:0% +that would trigger because its + + + align:start position:0% +that would trigger because its +distance from from the mean is unusual + + align:start position:0% + + + + align:start position:0% + +now if I actually didn't + + align:start position:0% +now if I actually didn't + + + align:start position:0% +now if I actually didn't +know my true covariance Matrix but I had + + align:start position:0% +know my true covariance Matrix but I had + + + align:start position:0% +know my true covariance Matrix but I had +to estimate it I have to + + align:start position:0% +to estimate it I have to + + + align:start position:0% +to estimate it I have to +estimate Sigma with an S I'm I'm right + + align:start position:0% +estimate Sigma with an S I'm I'm right + + + align:start position:0% +estimate Sigma with an S I'm I'm right +back to this whole difference between a + + align:start position:0% +back to this whole difference between a + + + align:start position:0% +back to this whole difference between a +t and a unit normal so uh just to close + + align:start position:0% +t and a unit normal so uh just to close + + + align:start position:0% +t and a unit normal so uh just to close +this out we often talk about these as + + align:start position:0% +this out we often talk about these as + + + align:start position:0% +this out we often talk about these as +t^2 totaling t^2 statistics but it's + + align:start position:0% +t^2 totaling t^2 statistics but it's + + + align:start position:0% +t^2 totaling t^2 statistics but it's +it's exactly the same idea + + align:start position:0% +it's exactly the same idea + + + align:start position:0% +it's exactly the same idea +and it's got its own uh cff + + align:start position:0% +and it's got its own uh cff + + + align:start position:0% +and it's got its own uh cff +points okay so with that I think we've + + align:start position:0% +points okay so with that I think we've + + + align:start position:0% +points okay so with that I think we've +sort of pulled to a close on control + + align:start position:0% +sort of pulled to a close on control + + + align:start position:0% +sort of pulled to a close on control +charting for the for the at least for + + align:start position:0% +charting for the for the at least for + + + align:start position:0% +charting for the for the at least for +the time being uh next time we'll start + + align:start position:0% +the time being uh next time we'll start + + + align:start position:0% +the time being uh next time we'll start +diving in on yield modeling in different + + align:start position:0% +diving in on yield modeling in different + + + align:start position:0% +diving in on yield modeling in different +uses of some statistics but I think what + + align:start position:0% +uses of some statistics but I think what + + + align:start position:0% +uses of some statistics but I think what +you've got now is some exposure to ewma + + align:start position:0% +you've got now is some exposure to ewma + + + align:start position:0% +you've got now is some exposure to ewma +qm You'll play around with those with + + align:start position:0% +qm You'll play around with those with + + + align:start position:0% +qm You'll play around with those with +the three or four problems on this + + align:start position:0% +the three or four problems on this + + + align:start position:0% +the three or four problems on this +week's problem set um and start looking + + align:start position:0% +week's problem set um and start looking + + + align:start position:0% +week's problem set um and start looking +at the quizzes we'll have the first quiz + + align:start position:0% +at the quizzes we'll have the first quiz + + + align:start position:0% +at the quizzes we'll have the first quiz +a week from today in class + + align:start position:0% +a week from today in class + + + align:start position:0% +a week from today in class +so Professor I have a question yeah we + + align:start position:0% +so Professor I have a question yeah we + + + align:start position:0% +so Professor I have a question yeah we +go ahead and break I'll I'll I'll take + + align:start position:0% +go ahead and break I'll I'll I'll take + + + align:start position:0% +go ahead and break I'll I'll I'll take +your question while people are are are + + align:start position:0% +your question while people are are are + + + align:start position:0% +your question while people are are are +dispersing so so for the cont you tght + + align:start position:0% +dispersing so so for the cont you tght + + + align:start position:0% +dispersing so so for the cont you tght +us today are they going to be included + + align:start position:0% +us today are they going to be included + + + align:start position:0% +us today are they going to be included +in the quiz uh you might see a it's + + align:start position:0% +in the quiz uh you might see a it's + + + align:start position:0% +in the quiz uh you might see a it's +possible you'll see an ewma or a qome + + align:start position:0% +possible you'll see an ewma or a qome + + + align:start position:0% +possible you'll see an ewma or a qome +but uh they would only be fairly simple + + align:start position:0% +but uh they would only be fairly simple + + + align:start position:0% +but uh they would only be fairly simple +uh questions for those it's not likely + + align:start position:0% +uh questions for those it's not likely + + + align:start position:0% +uh questions for those it's not likely +you'll see a multivariant + + align:start position:0% +you'll see a multivariant + + + align:start position:0% +you'll see a multivariant +problem okay thank you \ No newline at end of file diff --git a/NvTZT0U01jc.txt b/NvTZT0U01jc.txt new file mode 100644 index 0000000000000000000000000000000000000000..85073619fd101a564725d3d041bddebef58be4bc --- /dev/null +++ b/NvTZT0U01jc.txt @@ -0,0 +1,3307 @@ +align:start position:0% + +we discovered uh in the last several + + align:start position:0% +we discovered uh in the last several + + + align:start position:0% +we discovered uh in the last several +years + + align:start position:0% +years + + + align:start position:0% +years +is that this this plume of groundwater + + align:start position:0% +is that this this plume of groundwater + + + align:start position:0% +is that this this plume of groundwater +that's coming toward the lake and + + align:start position:0% +that's coming toward the lake and + + + align:start position:0% +that's coming toward the lake and +actually continuing on to the south + + align:start position:0% +actually continuing on to the south + + + align:start position:0% +actually continuing on to the south +we'll see that at the end of the trip + + align:start position:0% +we'll see that at the end of the trip + + + align:start position:0% +we'll see that at the end of the trip +is discharging it to what they call + + align:start position:0% +is discharging it to what they call + + + align:start position:0% +is discharging it to what they call +fisherman's cove right here + + align:start position:0% +fisherman's cove right here + + + align:start position:0% +fisherman's cove right here +all right and uh the way we discovered + + align:start position:0% +all right and uh the way we discovered + + + align:start position:0% +all right and uh the way we discovered +that + + align:start position:0% +that + + + align:start position:0% +that +was we were drilling wells somebody was + + align:start position:0% +was we were drilling wells somebody was + + + align:start position:0% +was we were drilling wells somebody was +asking earlier you know how do you do + + align:start position:0% +asking earlier you know how do you do + + + align:start position:0% +asking earlier you know how do you do +this well you drill well you sort of + + align:start position:0% +this well you drill well you sort of + + + align:start position:0% +this well you drill well you sort of +leapfrog your way down and + + align:start position:0% +leapfrog your way down and + + + align:start position:0% +leapfrog your way down and +suddenly there you are at the lake shore + + align:start position:0% +suddenly there you are at the lake shore + + + align:start position:0% +suddenly there you are at the lake shore +with your drill rig and you realize the + + align:start position:0% +with your drill rig and you realize the + + + align:start position:0% +with your drill rig and you realize the +next step is the lake + + align:start position:0% +next step is the lake + + + align:start position:0% +next step is the lake +so the thought was that the plume must + + align:start position:0% +so the thought was that the plume must + + + align:start position:0% +so the thought was that the plume must +be discharging into the like + + align:start position:0% +be discharging into the like + + + align:start position:0% +be discharging into the like +and so what we did is we went out + + align:start position:0% +and so what we did is we went out + + + align:start position:0% +and so what we did is we went out +into the lake itself a number of times + + align:start position:0% +into the lake itself a number of times + + + align:start position:0% +into the lake itself a number of times +over the last several years + + align:start position:0% +over the last several years + + + align:start position:0% +over the last several years +with a number of different devices + + align:start position:0% +with a number of different devices + + + align:start position:0% +with a number of different devices +driving devices like this one here is a + + align:start position:0% +driving devices like this one here is a + + + align:start position:0% +driving devices like this one here is a +good example + + align:start position:0% +good example + + + align:start position:0% +good example +a little temporary uh drive point it's a + + align:start position:0% +a little temporary uh drive point it's a + + + align:start position:0% +a little temporary uh drive point it's a +little multi-level sample like you saw + + align:start position:0% +little multi-level sample like you saw + + + align:start position:0% +little multi-level sample like you saw +before + + align:start position:0% +before + + + align:start position:0% +before +it's made out of steel instead so you + + align:start position:0% +it's made out of steel instead so you + + + align:start position:0% +it's made out of steel instead so you +can go out + + align:start position:0% +can go out + + + align:start position:0% +can go out +in the lake in waders or in a boat drive + + align:start position:0% +in the lake in waders or in a boat drive + + + align:start position:0% +in the lake in waders or in a boat drive +it in + + align:start position:0% +it in + + + align:start position:0% +it in +and then collect water samples out of + + align:start position:0% +and then collect water samples out of + + + align:start position:0% +and then collect water samples out of +the top of it and the idea being what's + + align:start position:0% +the top of it and the idea being what's + + + align:start position:0% +the top of it and the idea being what's +the water quality of the groundwater as + + align:start position:0% +the water quality of the groundwater as + + + align:start position:0% +the water quality of the groundwater as +it's coming into the lake + + align:start position:0% +it's coming into the lake + + + align:start position:0% +it's coming into the lake +right so we see it all the way to here + + align:start position:0% +right so we see it all the way to here + + + align:start position:0% +right so we see it all the way to here +what's the water quality look like + + align:start position:0% +what's the water quality look like + + + align:start position:0% +what's the water quality look like +another device we've used uh is + + align:start position:0% +another device we've used uh is + + + align:start position:0% +another device we've used uh is +something like this it's called the + + align:start position:0% +something like this it's called the + + + align:start position:0% +something like this it's called the +henry sampler it's a little tiny sampler + + align:start position:0% +henry sampler it's a little tiny sampler + + + align:start position:0% +henry sampler it's a little tiny sampler +let me just give you and + + align:start position:0% +let me just give you and + + + align:start position:0% +let me just give you and +show you how this works real easy + + align:start position:0% +show you how this works real easy + + + align:start position:0% +show you how this works real easy +it's kind of neat it's got a little tiny + + align:start position:0% +it's kind of neat it's got a little tiny + + + align:start position:0% +it's kind of neat it's got a little tiny +point on the end oh that's gross + + align:start position:0% +point on the end oh that's gross + + + align:start position:0% +point on the end oh that's gross +and it's got a little inner rod to give + + align:start position:0% +and it's got a little inner rod to give + + + align:start position:0% +and it's got a little inner rod to give +it some strength and you can see + + align:start position:0% +it some strength and you can see + + + align:start position:0% +it some strength and you can see +you'll see the end you know it's slotted + + align:start position:0% +you'll see the end you know it's slotted + + + align:start position:0% +you'll see the end you know it's slotted +on the end can you vouch for the rest of + + align:start position:0% +on the end can you vouch for the rest of + + + align:start position:0% +on the end can you vouch for the rest of +them that it's slotted on the end + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +when you shove it in like this and you + + align:start position:0% +when you shove it in like this and you + + + align:start position:0% +when you shove it in like this and you +pull out the little center rod like that + + align:start position:0% + + + + align:start position:0% + +and then you can put the syringe on it + + align:start position:0% +and then you can put the syringe on it + + + align:start position:0% +and then you can put the syringe on it +or a pump of any kind + + align:start position:0% + + + + align:start position:0% + +then you can get your water sample + + align:start position:0% +then you can get your water sample + + + align:start position:0% +then you can get your water sample +that's all there is to it + + align:start position:0% +that's all there is to it + + + align:start position:0% +that's all there is to it +that's a little crappy because it's + + align:start position:0% +that's a little crappy because it's + + + align:start position:0% +that's a little crappy because it's +obviously uh + + align:start position:0% +obviously uh + + + align:start position:0% +obviously uh +so so what we did is we went to um + + align:start position:0% +so so what we did is we went to um + + + align:start position:0% +so so what we did is we went to um +we went to dozens if not hundreds of + + align:start position:0% +we went to dozens if not hundreds of + + + align:start position:0% +we went to dozens if not hundreds of +locations here in the lake + + align:start position:0% +locations here in the lake + + + align:start position:0% +locations here in the lake +uh in this area and + + align:start position:0% +uh in this area and + + + align:start position:0% +uh in this area and +you see on page 15 we actually mapped + + align:start position:0% +you see on page 15 we actually mapped + + + align:start position:0% +you see on page 15 we actually mapped +out what the plume looks like coming out + + align:start position:0% +out what the plume looks like coming out + + + align:start position:0% +out what the plume looks like coming out +into the pond bottom + + align:start position:0% +into the pond bottom + + + align:start position:0% +into the pond bottom +right this is specific conductance i + + align:start position:0% +right this is specific conductance i + + + align:start position:0% +right this is specific conductance i +mentioned conductance before it's just a + + align:start position:0% +mentioned conductance before it's just a + + + align:start position:0% +mentioned conductance before it's just a +general measure of the inorganics in the + + align:start position:0% +general measure of the inorganics in the + + + align:start position:0% +general measure of the inorganics in the +water + + align:start position:0% +water + + + align:start position:0% +water +higher conductance more dissolved stuff + + align:start position:0% +higher conductance more dissolved stuff + + + align:start position:0% +higher conductance more dissolved stuff +in the water + + align:start position:0% +in the water + + + align:start position:0% +in the water +this is the conductance we measured all + + align:start position:0% +this is the conductance we measured all + + + align:start position:0% +this is the conductance we measured all +the little dots show you locations where + + align:start position:0% +the little dots show you locations where + + + align:start position:0% +the little dots show you locations where +they went out here with a little well + + align:start position:0% +they went out here with a little well + + + align:start position:0% +they went out here with a little well +point + + align:start position:0% +point + + + align:start position:0% +point +we actually had a boat and we had a + + align:start position:0% +we actually had a boat and we had a + + + align:start position:0% +we actually had a boat and we had a +barge at one point + + align:start position:0% +barge at one point + + + align:start position:0% +barge at one point +because it gets a little hard to work in + + align:start position:0% +because it gets a little hard to work in + + + align:start position:0% +because it gets a little hard to work in +water you know when it gets too deep + + align:start position:0% +water you know when it gets too deep + + + align:start position:0% +water you know when it gets too deep +um and we did that in three times 99 + + align:start position:0% +um and we did that in three times 99 + + + align:start position:0% +um and we did that in three times 99 +2001 2003 + + align:start position:0% +2001 2003 + + + align:start position:0% +2001 2003 +you'll notice there's a clear change in + + align:start position:0% +you'll notice there's a clear change in + + + align:start position:0% +you'll notice there's a clear change in +the nature of the map as you go with + + align:start position:0% +the nature of the map as you go with + + + align:start position:0% +the nature of the map as you go with +time + + align:start position:0% +time + + + align:start position:0% +time +see how it's it's high in 99 and then + + align:start position:0% +see how it's it's high in 99 and then + + + align:start position:0% +see how it's it's high in 99 and then +you seem to see a decrease in + + align:start position:0% +you seem to see a decrease in + + + align:start position:0% +you seem to see a decrease in +concentrations or conductance as you go + + align:start position:0% +concentrations or conductance as you go + + + align:start position:0% +concentrations or conductance as you go +later in the in the time + + align:start position:0% +later in the in the time + + + align:start position:0% +later in the in the time +what that is is that that trailing edge + + align:start position:0% +what that is is that that trailing edge + + + align:start position:0% +what that is is that that trailing edge +we were talking about the plume + + align:start position:0% +we were talking about the plume + + + align:start position:0% +we were talking about the plume +that natural flushing is actually in + + align:start position:0% +that natural flushing is actually in + + + align:start position:0% +that natural flushing is actually in +this time period began to arrive right + + align:start position:0% +this time period began to arrive right + + + align:start position:0% +this time period began to arrive right +in here + + align:start position:0% +in here + + + align:start position:0% +in here +the tail end of the plume is leaving + + align:start position:0% +the tail end of the plume is leaving + + + align:start position:0% +the tail end of the plume is leaving +this neighborhood now + + align:start position:0% +this neighborhood now + + + align:start position:0% +this neighborhood now +and in fact we did some sampling in 2004 + + align:start position:0% +and in fact we did some sampling in 2004 + + + align:start position:0% +and in fact we did some sampling in 2004 +and it's even more + + align:start position:0% +and it's even more + + + align:start position:0% +and it's even more +diminished so for many years the plume + + align:start position:0% +diminished so for many years the plume + + + align:start position:0% +diminished so for many years the plume +used to discharge here + + align:start position:0% +used to discharge here + + + align:start position:0% +used to discharge here +but now that they've shot off the plant + + align:start position:0% +but now that they've shot off the plant + + + align:start position:0% +but now that they've shot off the plant +it's gradually cleaning itself out and + + align:start position:0% +it's gradually cleaning itself out and + + + align:start position:0% +it's gradually cleaning itself out and +the water coming up into the pond here + + align:start position:0% +the water coming up into the pond here + + + align:start position:0% +the water coming up into the pond here +is obviously of a better quality than it + + align:start position:0% +is obviously of a better quality than it + + + align:start position:0% +is obviously of a better quality than it +used to be + + align:start position:0% +used to be + + + align:start position:0% +used to be +because you see that clearly indicated + + align:start position:0% +because you see that clearly indicated + + + align:start position:0% +because you see that clearly indicated +here we see that with boron + + align:start position:0% +here we see that with boron + + + align:start position:0% +here we see that with boron +we see with nitrate and so forth right + + align:start position:0% +we see with nitrate and so forth right + + + align:start position:0% +we see with nitrate and so forth right +um + + align:start position:0% +um + + + align:start position:0% +um +but turn the next page look at + + align:start position:0% +but turn the next page look at + + + align:start position:0% +but turn the next page look at +phosphorus + + align:start position:0% +phosphorus + + + align:start position:0% +phosphorus +same three views this is phosphorous + + align:start position:0% +same three views this is phosphorous + + + align:start position:0% +same three views this is phosphorous +all right and you'll see that the + + align:start position:0% +all right and you'll see that the + + + align:start position:0% +all right and you'll see that the +phosphorus high zone + + align:start position:0% +phosphorus high zone + + + align:start position:0% +phosphorus high zone +is right where we're standing right now + + align:start position:0% +is right where we're standing right now + + + align:start position:0% +is right where we're standing right now +on this bluff + + align:start position:0% +on this bluff + + + align:start position:0% +on this bluff +and you'll notice that it doesn't change + + align:start position:0% +and you'll notice that it doesn't change + + + align:start position:0% +and you'll notice that it doesn't change +at all to speak out the time + + align:start position:0% +at all to speak out the time + + + align:start position:0% +at all to speak out the time +see how it hasn't changed okay that's + + align:start position:0% +see how it hasn't changed okay that's + + + align:start position:0% +see how it hasn't changed okay that's +this whole business of phosphorus + + align:start position:0% +this whole business of phosphorus + + + align:start position:0% +this whole business of phosphorus +retardation + + align:start position:0% +retardation + + + align:start position:0% +retardation +the tail end of the plume is leaving but + + align:start position:0% +the tail end of the plume is leaving but + + + align:start position:0% +the tail end of the plume is leaving but +the phosphorus is like ink on a sponge + + align:start position:0% +the phosphorus is like ink on a sponge + + + align:start position:0% +the phosphorus is like ink on a sponge +it just doesn't want to rinse off + + align:start position:0% +it just doesn't want to rinse off + + + align:start position:0% +it just doesn't want to rinse off +so it's going to take many many many + + align:start position:0% +so it's going to take many many many + + + align:start position:0% +so it's going to take many many many +flushes for the phosphorus to be + + align:start position:0% +flushes for the phosphorus to be + + + align:start position:0% +flushes for the phosphorus to be +purged off the system and so long after + + align:start position:0% +purged off the system and so long after + + + align:start position:0% +purged off the system and so long after +the rest of the plume has left + + align:start position:0% +the rest of the plume has left + + + align:start position:0% +the rest of the plume has left +there'll be phosphate discharging to the + + align:start position:0% +there'll be phosphate discharging to the + + + align:start position:0% +there'll be phosphate discharging to the +lake at relatively high levels because + + align:start position:0% +lake at relatively high levels because + + + align:start position:0% +lake at relatively high levels because +99 of it's on the sediments and it has + + align:start position:0% +99 of it's on the sediments and it has + + + align:start position:0% +99 of it's on the sediments and it has +to flush off + + align:start position:0% +to flush off + + + align:start position:0% +to flush off +okay so the concern is that the + + align:start position:0% +okay so the concern is that the + + + align:start position:0% +okay so the concern is that the +phosphorous load to the lake is just + + align:start position:0% +phosphorous load to the lake is just + + + align:start position:0% +phosphorous load to the lake is just +going to go on for almost forever + + align:start position:0% +going to go on for almost forever + + + align:start position:0% +going to go on for almost forever +relatively speaking and the + + align:start position:0% +relatively speaking and the + + + align:start position:0% +relatively speaking and the +limonologists have said that's just too + + align:start position:0% +limonologists have said that's just too + + + align:start position:0% +limonologists have said that's just too +high a loading rate + + align:start position:0% +high a loading rate + + + align:start position:0% +high a loading rate +so the military was under the gun so to + + align:start position:0% +so the military was under the gun so to + + + align:start position:0% +so the military was under the gun so to +speak + + align:start position:0% +speak + + + align:start position:0% +speak +to um to try to cut down on the load of + + align:start position:0% +to um to try to cut down on the load of + + + align:start position:0% +to um to try to cut down on the load of +phosphate to the lake + + align:start position:0% +phosphate to the lake + + + align:start position:0% +phosphate to the lake +because they were responsible for like + + align:start position:0% +because they were responsible for like + + + align:start position:0% +because they were responsible for like +60 or 70 percent of it so they looked at + + align:start position:0% +60 or 70 percent of it so they looked at + + + align:start position:0% +60 or 70 percent of it so they looked at +a variety of options one was to + + align:start position:0% +a variety of options one was to + + + align:start position:0% +a variety of options one was to +provide soaring for all the homes okay + + align:start position:0% +provide soaring for all the homes okay + + + align:start position:0% +provide soaring for all the homes okay +in other words we'll let our phosphorus + + align:start position:0% +in other words we'll let our phosphorus + + + align:start position:0% +in other words we'll let our phosphorus +go in because it's too hard to get it + + align:start position:0% +go in because it's too hard to get it + + + align:start position:0% +go in because it's too hard to get it +out + + align:start position:0% +out + + + align:start position:0% +out +but we'll we'll take care of any new + + align:start position:0% +but we'll we'll take care of any new + + + align:start position:0% +but we'll we'll take care of any new +loads well it turns out that wasn't + + align:start position:0% +loads well it turns out that wasn't + + + align:start position:0% +loads well it turns out that wasn't +enough there are very few homes on the + + align:start position:0% +enough there are very few homes on the + + + align:start position:0% +enough there are very few homes on the +upgrading side of the lake + + align:start position:0% +upgrading side of the lake + + + align:start position:0% +upgrading side of the lake +it's mostly the military base they + + align:start position:0% +it's mostly the military base they + + + align:start position:0% +it's mostly the military base they +looked at putting in pumping wells + + align:start position:0% +looked at putting in pumping wells + + + align:start position:0% +looked at putting in pumping wells +and pumping but because phosphorus + + align:start position:0% +and pumping but because phosphorus + + + align:start position:0% +and pumping but because phosphorus +doesn't like to move you have to pump + + align:start position:0% +doesn't like to move you have to pump + + + align:start position:0% +doesn't like to move you have to pump +forever + + align:start position:0% +forever + + + align:start position:0% +forever +so they were looking for something that + + align:start position:0% +so they were looking for something that + + + align:start position:0% +so they were looking for something that +was a lot more passive when + + align:start position:0% +was a lot more passive when + + + align:start position:0% +was a lot more passive when +we mapped out this footprint they began + + align:start position:0% +we mapped out this footprint they began + + + align:start position:0% +we mapped out this footprint they began +to realize + + align:start position:0% +to realize + + + align:start position:0% +to realize +gee the area where most of the + + align:start position:0% +gee the area where most of the + + + align:start position:0% +gee the area where most of the +phosphorus is coming in it's not like a + + align:start position:0% +phosphorus is coming in it's not like a + + + align:start position:0% +phosphorus is coming in it's not like a +volatile organic or cancer-causing + + align:start position:0% +volatile organic or cancer-causing + + + align:start position:0% +volatile organic or cancer-causing +chemical where you have to get it all if + + align:start position:0% +chemical where you have to get it all if + + + align:start position:0% +chemical where you have to get it all if +they could knock down the load by 80 + + align:start position:0% +they could knock down the load by 80 + + + align:start position:0% +they could knock down the load by 80 +percent they'd be + + align:start position:0% +percent they'd be + + + align:start position:0% +percent they'd be +way ahead and they noticed that the the + + align:start position:0% +way ahead and they noticed that the the + + + align:start position:0% +way ahead and they noticed that the the +footprint if you want to think of it + + align:start position:0% +footprint if you want to think of it + + + align:start position:0% +footprint if you want to think of it +that way the discharge area + + align:start position:0% +that way the discharge area + + + align:start position:0% +that way the discharge area +was relatively small so if they could + + align:start position:0% +was relatively small so if they could + + + align:start position:0% +was relatively small so if they could +put something down + + align:start position:0% +put something down + + + align:start position:0% +put something down +on the pawn bottom some sort of reactive + + align:start position:0% +on the pawn bottom some sort of reactive + + + align:start position:0% +on the pawn bottom some sort of reactive +media to capture like a sorbent + + align:start position:0% +media to capture like a sorbent + + + align:start position:0% +media to capture like a sorbent +they could capture the phosphorus right + + align:start position:0% +they could capture the phosphorus right + + + align:start position:0% +they could capture the phosphorus right +where it's coming out + + align:start position:0% +where it's coming out + + + align:start position:0% +where it's coming out +and and not let it get in the lake that + + align:start position:0% +and and not let it get in the lake that + + + align:start position:0% +and and not let it get in the lake that +way and if they could do something that + + align:start position:0% +way and if they could do something that + + + align:start position:0% +way and if they could do something that +was passive they wouldn't have to do + + align:start position:0% +was passive they wouldn't have to do + + + align:start position:0% +was passive they wouldn't have to do +anything more than that + + align:start position:0% +anything more than that + + + align:start position:0% +anything more than that +so the idea was to find something that + + align:start position:0% +so the idea was to find something that + + + align:start position:0% +so the idea was to find something that +they could lay out once and then walk + + align:start position:0% +they could lay out once and then walk + + + align:start position:0% +they could lay out once and then walk +away from + + align:start position:0% +away from + + + align:start position:0% +away from +right um and then it's not nothing wrong + + align:start position:0% +right um and then it's not nothing wrong + + + align:start position:0% +right um and then it's not nothing wrong +that's a great philosophy so um so what + + align:start position:0% +that's a great philosophy so um so what + + + align:start position:0% +that's a great philosophy so um so what +they did + + align:start position:0% +they did + + + align:start position:0% +they did +um in um this august + + align:start position:0% +um in um this august + + + align:start position:0% +um in um this august +so this just literally happened just a + + align:start position:0% +so this just literally happened just a + + + align:start position:0% +so this just literally happened just a +few weeks ago they came out here + + align:start position:0% +few weeks ago they came out here + + + align:start position:0% +few weeks ago they came out here +it's too hot we had a i ran a filter for + + align:start position:0% +it's too hot we had a i ran a filter for + + + align:start position:0% +it's too hot we had a i ran a filter for +the umass uh + + align:start position:0% +the umass uh + + + align:start position:0% +the umass uh +boston students uh in august and it was + + align:start position:0% +boston students uh in august and it was + + + align:start position:0% +boston students uh in august and it was +going on it was amazing because they got + + align:start position:0% +going on it was amazing because they got + + + align:start position:0% +going on it was amazing because they got +to watch it + + align:start position:0% +to watch it + + + align:start position:0% +to watch it +going in um in an area you can see the + + align:start position:0% +going in um in an area you can see the + + + align:start position:0% +going in um in an area you can see the +little pin flags out there + + align:start position:0% +little pin flags out there + + + align:start position:0% +little pin flags out there +in an area 40 feet wide from about right + + align:start position:0% +in an area 40 feet wide from about right + + + align:start position:0% +in an area 40 feet wide from about right +about here + + align:start position:0% +about here + + + align:start position:0% +about here +roughly where i'm standing here about 40 + + align:start position:0% +roughly where i'm standing here about 40 + + + align:start position:0% +roughly where i'm standing here about 40 +feet and then 300 feet long + + align:start position:0% +feet and then 300 feet long + + + align:start position:0% +feet and then 300 feet long +they put out a cofferdam you know what a + + align:start position:0% +they put out a cofferdam you know what a + + + align:start position:0% +they put out a cofferdam you know what a +cofferdam is + + align:start position:0% +cofferdam is + + + align:start position:0% +cofferdam is +you know for engineering it was made out + + align:start position:0% +you know for engineering it was made out + + + align:start position:0% +you know for engineering it was made out +of big bladders that they inflated so + + align:start position:0% +of big bladders that they inflated so + + + align:start position:0% +of big bladders that they inflated so +they put out a copper dam + + align:start position:0% +they put out a copper dam + + + align:start position:0% +they put out a copper dam +and then they had two pumps three pumps + + align:start position:0% +and then they had two pumps three pumps + + + align:start position:0% +and then they had two pumps three pumps +that could pump a total of six thousand + + align:start position:0% +that could pump a total of six thousand + + + align:start position:0% +that could pump a total of six thousand +gallons a minute + + align:start position:0% +gallons a minute + + + align:start position:0% +gallons a minute +and they de-watered the pond up to the + + align:start position:0% +and they de-watered the pond up to the + + + align:start position:0% +and they de-watered the pond up to the +copper dams + + align:start position:0% +copper dams + + + align:start position:0% +copper dams +okay then they came in with excavators + + align:start position:0% +okay then they came in with excavators + + + align:start position:0% +okay then they came in with excavators +and they dug down + + align:start position:0% +and they dug down + + + align:start position:0% +and they dug down +three feet and they mixed into the + + align:start position:0% +three feet and they mixed into the + + + align:start position:0% +three feet and they mixed into the +natural sediments + + align:start position:0% +natural sediments + + + align:start position:0% +natural sediments +zero valence or elemental iron + + align:start position:0% +zero valence or elemental iron + + + align:start position:0% +zero valence or elemental iron +okay the idea being that the iron would + + align:start position:0% +okay the idea being that the iron would + + + align:start position:0% +okay the idea being that the iron would +rust + + align:start position:0% +rust + + + align:start position:0% +rust +turn into iron oxide and what do we say + + align:start position:0% +turn into iron oxide and what do we say + + + align:start position:0% +turn into iron oxide and what do we say +phosphorus likes to stick to + + align:start position:0% +phosphorus likes to stick to + + + align:start position:0% +phosphorus likes to stick to +iron oxide so as the groundwater passes + + align:start position:0% +iron oxide so as the groundwater passes + + + align:start position:0% +iron oxide so as the groundwater passes +up through this reactive blanket of iron + + align:start position:0% +up through this reactive blanket of iron + + + align:start position:0% +up through this reactive blanket of iron +it would be absorbed out by all this + + align:start position:0% +it would be absorbed out by all this + + + align:start position:0% +it would be absorbed out by all this +iron they added to the aquifer and never + + align:start position:0% +iron they added to the aquifer and never + + + align:start position:0% +iron they added to the aquifer and never +make it into the lake + + align:start position:0% +make it into the lake + + + align:start position:0% +make it into the lake +that's the idea that's why the shore is + + align:start position:0% +that's the idea that's why the shore is + + + align:start position:0% +that's the idea that's why the shore is +red + + align:start position:0% +red + + + align:start position:0% +red +it's the iron rusting this was used to + + align:start position:0% +it's the iron rusting this was used to + + + align:start position:0% +it's the iron rusting this was used to +be black + + align:start position:0% +be black + + + align:start position:0% +be black +so this is this is the iron rusting um + + align:start position:0% +so this is this is the iron rusting um + + + align:start position:0% +so this is this is the iron rusting um +on the pond bottom + + align:start position:0% +on the pond bottom + + + align:start position:0% +on the pond bottom +and sorting out the phosphorus in theory + + align:start position:0% +and sorting out the phosphorus in theory + + + align:start position:0% +and sorting out the phosphorus in theory +well we've all we have not the first + + align:start position:0% +well we've all we have not the first + + + align:start position:0% +well we've all we have not the first +post installation monitoring is only + + align:start position:0% +post installation monitoring is only + + + align:start position:0% +post installation monitoring is only +going to take place at the end of + + align:start position:0% +going to take place at the end of + + + align:start position:0% +going to take place at the end of +october + + align:start position:0% +october + + + align:start position:0% +october +okay now we've done some prelim we + + align:start position:0% +okay now we've done some prelim we + + + align:start position:0% +okay now we've done some prelim we +couldn't wait so we've done some + + align:start position:0% +couldn't wait so we've done some + + + align:start position:0% +couldn't wait so we've done some +preliminary sampling and + + align:start position:0% +preliminary sampling and + + + align:start position:0% +preliminary sampling and +we don't see phosphate in the water + + align:start position:0% +we don't see phosphate in the water + + + align:start position:0% +we don't see phosphate in the water +samples above the iron + + align:start position:0% +samples above the iron + + + align:start position:0% +samples above the iron +all right um what we did is um + + align:start position:0% +all right um what we did is um + + + align:start position:0% +all right um what we did is um +there was a concern that any kind of + + align:start position:0% +there was a concern that any kind of + + + align:start position:0% +there was a concern that any kind of +monitoring that we would do + + align:start position:0% +monitoring that we would do + + + align:start position:0% +monitoring that we would do +could potentially drag iron down to + + align:start position:0% +could potentially drag iron down to + + + align:start position:0% +could potentially drag iron down to +below the iron zone + + align:start position:0% +below the iron zone + + + align:start position:0% +below the iron zone +so if you were to try to drive things in + + align:start position:0% +so if you were to try to drive things in + + + align:start position:0% +so if you were to try to drive things in +after they put the iron in a little bit + + align:start position:0% +after they put the iron in a little bit + + + align:start position:0% +after they put the iron in a little bit +of iron would go down with your well + + align:start position:0% +of iron would go down with your well + + + align:start position:0% +of iron would go down with your well +point and then it would remediate the + + align:start position:0% +point and then it would remediate the + + + align:start position:0% +point and then it would remediate the +phosphorus and you'd never find it again + + align:start position:0% +phosphorus and you'd never find it again + + + align:start position:0% +phosphorus and you'd never find it again +so + + align:start position:0% +so + + + align:start position:0% +so +we decided to instrument the si + + align:start position:0% +we decided to instrument the si + + + align:start position:0% +we decided to instrument the si +the site as they did the excavations so + + align:start position:0% +the site as they did the excavations so + + + align:start position:0% +the site as they did the excavations so +we put out four different kinds of + + align:start position:0% +we put out four different kinds of + + + align:start position:0% +we put out four different kinds of +instrumentation + + align:start position:0% +instrumentation + + + align:start position:0% +instrumentation +um let's see if i can point a lot of you + + align:start position:0% +um let's see if i can point a lot of you + + + align:start position:0% +um let's see if i can point a lot of you +can't see + + align:start position:0% +can't see + + + align:start position:0% +can't see +uh one of them is right there see that + + align:start position:0% +uh one of them is right there see that + + + align:start position:0% +uh one of them is right there see that +little green cap + + align:start position:0% +little green cap + + + align:start position:0% +little green cap +that's one of these guys + + align:start position:0% + + + + align:start position:0% + +uh it's one of those like that little + + align:start position:0% +uh it's one of those like that little + + + align:start position:0% +uh it's one of those like that little +driven mls i showed you except it's made + + align:start position:0% +driven mls i showed you except it's made + + + align:start position:0% +driven mls i showed you except it's made +out of plastic + + align:start position:0% +out of plastic + + + align:start position:0% +out of plastic +we made out of plastic because we + + align:start position:0% +we made out of plastic because we + + + align:start position:0% +we made out of plastic because we +thought that anything steel would start + + align:start position:0% +thought that anything steel would start + + + align:start position:0% +thought that anything steel would start +to corrode like crazy + + align:start position:0% +to corrode like crazy + + + align:start position:0% +to corrode like crazy +inside here if i open this up it's a + + align:start position:0% +inside here if i open this up it's a + + + align:start position:0% +inside here if i open this up it's a +coil of little tubes + + align:start position:0% +coil of little tubes + + + align:start position:0% +coil of little tubes +so every one of those green guys that + + align:start position:0% +so every one of those green guys that + + + align:start position:0% +so every one of those green guys that +are along the shore are these little + + align:start position:0% +are along the shore are these little + + + align:start position:0% +are along the shore are these little +miniature multi-level samplers + + align:start position:0% +miniature multi-level samplers + + + align:start position:0% +miniature multi-level samplers +and the iron zone will go from about the + + align:start position:0% +and the iron zone will go from about the + + + align:start position:0% +and the iron zone will go from about the +surface down to about three feet so we + + align:start position:0% +surface down to about three feet so we + + + align:start position:0% +surface down to about three feet so we +always have one port below the iron + + align:start position:0% +always have one port below the iron + + + align:start position:0% +always have one port below the iron +so we can see phosphate down here and + + align:start position:0% +so we can see phosphate down here and + + + align:start position:0% +so we can see phosphate down here and +then we can see the phosphate disappear + + align:start position:0% +then we can see the phosphate disappear + + + align:start position:0% +then we can see the phosphate disappear +as the water comes up + + align:start position:0% +as the water comes up + + + align:start position:0% +as the water comes up +why does that make sense to everybody so + + align:start position:0% +why does that make sense to everybody so + + + align:start position:0% +why does that make sense to everybody so +we have a bunch of those out in fact i + + align:start position:0% +we have a bunch of those out in fact i + + + align:start position:0% +we have a bunch of those out in fact i +think + + align:start position:0% +think + + + align:start position:0% +think +you have a map maybe page you can't read + + align:start position:0% +you have a map maybe page you can't read + + + align:start position:0% +you have a map maybe page you can't read +the page numbers but the next map + + align:start position:0% +the page numbers but the next map + + + align:start position:0% +the page numbers but the next map +actually shows you where the instruments + + align:start position:0% +actually shows you where the instruments + + + align:start position:0% +actually shows you where the instruments +are + + align:start position:0% +are + + + align:start position:0% +are +that actually shows you the footprint + + align:start position:0% +that actually shows you the footprint + + + align:start position:0% +that actually shows you the footprint +the second kind of device we have + + align:start position:0% +the second kind of device we have + + + align:start position:0% +the second kind of device we have +i don't think any of them are visible + + align:start position:0% +i don't think any of them are visible + + + align:start position:0% +i don't think any of them are visible +from here + + align:start position:0% + + + + align:start position:0% + +i don't see them um + + align:start position:0% +i don't see them um + + + align:start position:0% +i don't see them um +anyway it doesn't really matter um well + + align:start position:0% +anyway it doesn't really matter um well + + + align:start position:0% +anyway it doesn't really matter um well +here's one right here you can't really + + align:start position:0% +here's one right here you can't really + + + align:start position:0% +here's one right here you can't really +see it + + align:start position:0% +see it + + + align:start position:0% +see it +you know those multi-level samplers we + + align:start position:0% +you know those multi-level samplers we + + + align:start position:0% +you know those multi-level samplers we +had in the gravel pit + + align:start position:0% +had in the gravel pit + + + align:start position:0% +had in the gravel pit +it occurred to us why not put some of + + align:start position:0% +it occurred to us why not put some of + + + align:start position:0% +it occurred to us why not put some of +those horizontally + + align:start position:0% +those horizontally + + + align:start position:0% +those horizontally +so when they excavated down three feet + + align:start position:0% +so when they excavated down three feet + + + align:start position:0% +so when they excavated down three feet +we laid one of those white plastic + + align:start position:0% +we laid one of those white plastic + + + align:start position:0% +we laid one of those white plastic +multi-level samplers + + align:start position:0% +multi-level samplers + + + align:start position:0% +multi-level samplers +out 40 feet with ports just like the + + align:start position:0% +out 40 feet with ports just like the + + + align:start position:0% +out 40 feet with ports just like the +vertical ones + + align:start position:0% +vertical ones + + + align:start position:0% +vertical ones +and they all come up to a road box on + + align:start position:0% +and they all come up to a road box on + + + align:start position:0% +and they all come up to a road box on +the shore here so we'll be able to pump + + align:start position:0% +the shore here so we'll be able to pump + + + align:start position:0% +the shore here so we'll be able to pump +those and get samples out underneath the + + align:start position:0% +those and get samples out underneath the + + + align:start position:0% +those and get samples out underneath the +iron there + + align:start position:0% +iron there + + + align:start position:0% +iron there +we also have what we call the fusion + + align:start position:0% +we also have what we call the fusion + + + align:start position:0% +we also have what we call the fusion +samplers + + align:start position:0% +samplers + + + align:start position:0% +samplers +out there same principle i showed you + + align:start position:0% +out there same principle i showed you + + + align:start position:0% +out there same principle i showed you +with the diffusion samplers in the + + align:start position:0% +with the diffusion samplers in the + + + align:start position:0% +with the diffusion samplers in the +gravel pit except these are made out of + + align:start position:0% +gravel pit except these are made out of + + + align:start position:0% +gravel pit except these are made out of +little + + align:start position:0% +little + + + align:start position:0% +little +60 milliliter bottles with a little + + align:start position:0% +60 milliliter bottles with a little + + + align:start position:0% +60 milliliter bottles with a little +nylon fabric on the end + + align:start position:0% +nylon fabric on the end + + + align:start position:0% +nylon fabric on the end +and we actually have chambers that these + + align:start position:0% +and we actually have chambers that these + + + align:start position:0% +and we actually have chambers that these +bottles sit in + + align:start position:0% +bottles sit in + + + align:start position:0% +bottles sit in +uh where they're in contact with the + + align:start position:0% +uh where they're in contact with the + + + align:start position:0% +uh where they're in contact with the +aquifer so what we're gonna do is we + + align:start position:0% +aquifer so what we're gonna do is we + + + align:start position:0% +aquifer so what we're gonna do is we +have a rack of these bottles + + align:start position:0% +have a rack of these bottles + + + align:start position:0% +have a rack of these bottles +at every like say five or six + + align:start position:0% +at every like say five or six + + + align:start position:0% +at every like say five or six +centimeters maybe yeah five or six + + align:start position:0% +centimeters maybe yeah five or six + + + align:start position:0% +centimeters maybe yeah five or six +centimeters + + align:start position:0% +centimeters + + + align:start position:0% +centimeters +we're gonna we lower those in we get + + align:start position:0% +we're gonna we lower those in we get + + + align:start position:0% +we're gonna we lower those in we get +diffusion over very + + align:start position:0% +diffusion over very + + + align:start position:0% +diffusion over very +short distances and then we can pull + + align:start position:0% +short distances and then we can pull + + + align:start position:0% +short distances and then we can pull +these bottles out and analyze them for + + align:start position:0% +these bottles out and analyze them for + + + align:start position:0% +these bottles out and analyze them for +phosphate you know everything is geared + + align:start position:0% +phosphate you know everything is geared + + + align:start position:0% +phosphate you know everything is geared +towards trying to prove + + align:start position:0% +towards trying to prove + + + align:start position:0% +towards trying to prove +or trying to be sure that the phosphorus + + align:start position:0% +or trying to be sure that the phosphorus + + + align:start position:0% +or trying to be sure that the phosphorus +that's in the ground water below the + + align:start position:0% +that's in the ground water below the + + + align:start position:0% +that's in the ground water below the +iron as it comes up through the iron it + + align:start position:0% +iron as it comes up through the iron it + + + align:start position:0% +iron as it comes up through the iron it +goes away + + align:start position:0% +goes away + + + align:start position:0% +goes away +they have a plan if their first plan + + align:start position:0% + + + + align:start position:0% + +know in geologic time it'll all come off + + align:start position:0% +know in geologic time it'll all come off + + + align:start position:0% +know in geologic time it'll all come off +everything's on its way but by that + + align:start position:0% +everything's on its way but by that + + + align:start position:0% +everything's on its way but by that +point the cape will be gone + + align:start position:0% +point the cape will be gone + + + align:start position:0% +point the cape will be gone +you know because it's eroding away + + align:start position:0% +you know because it's eroding away + + + align:start position:0% +you know because it's eroding away +anyways uh the other thing too is + + align:start position:0% +anyways uh the other thing too is + + + align:start position:0% +anyways uh the other thing too is +apparently + + align:start position:0% +apparently + + + align:start position:0% +apparently +um i'm not a g chemist this is where i + + align:start position:0% +um i'm not a g chemist this is where i + + + align:start position:0% +um i'm not a g chemist this is where i +start to really he he knows more about + + align:start position:0% +start to really he he knows more about + + + align:start position:0% +start to really he he knows more about +it than i do + + align:start position:0% +it than i do + + + align:start position:0% +it than i do +uh pete does um + + align:start position:0% +uh pete does um + + + align:start position:0% +uh pete does um +apparently there's a fair amount of + + align:start position:0% +apparently there's a fair amount of + + + align:start position:0% +apparently there's a fair amount of +mineralization that can take place too + + align:start position:0% +mineralization that can take place too + + + align:start position:0% +mineralization that can take place too +so instead of just being a sort of a + + align:start position:0% +so instead of just being a sort of a + + + align:start position:0% +so instead of just being a sort of a +it's like it first absorbs on pretty + + align:start position:0% +it's like it first absorbs on pretty + + + align:start position:0% +it's like it first absorbs on pretty +loosely and then it begins to really + + align:start position:0% +loosely and then it begins to really + + + align:start position:0% +loosely and then it begins to really +work its way into the mineral matrix and + + align:start position:0% +work its way into the mineral matrix and + + + align:start position:0% +work its way into the mineral matrix and +then eventually you can actually get + + align:start position:0% +then eventually you can actually get + + + align:start position:0% +then eventually you can actually get +mineralization when you form things like + + align:start position:0% +mineralization when you form things like + + + align:start position:0% +mineralization when you form things like +appetite + + align:start position:0% +appetite + + + align:start position:0% +appetite +you actually get mineralization to form + + align:start position:0% +you actually get mineralization to form + + + align:start position:0% +you actually get mineralization to form +iron phosphate minerals + + align:start position:0% +iron phosphate minerals + + + align:start position:0% +iron phosphate minerals +which is gets much more solid so they + + align:start position:0% +which is gets much more solid so they + + + align:start position:0% +which is gets much more solid so they +think there's actually a fair amount of + + align:start position:0% +think there's actually a fair amount of + + + align:start position:0% +think there's actually a fair amount of +almost permanent removal for all + + align:start position:0% +almost permanent removal for all + + + align:start position:0% +almost permanent removal for all +practical purposes + + align:start position:0% +practical purposes + + + align:start position:0% +practical purposes +but the light can take a certain amount + + align:start position:0% +but the light can take a certain amount + + + align:start position:0% +but the light can take a certain amount +of phosphorus it's just this huge load + + align:start position:0% +of phosphorus it's just this huge load + + + align:start position:0% +of phosphorus it's just this huge load +for a short period of time is what's + + align:start position:0% +for a short period of time is what's + + + align:start position:0% +for a short period of time is what's +going to kill + + align:start position:0% +going to kill + + + align:start position:0% +going to kill +it's really important + + align:start position:0% +it's really important + + + align:start position:0% +it's really important +right the other thing they did is they + + align:start position:0% +right the other thing they did is they + + + align:start position:0% +right the other thing they did is they +um dosed the pond with alum aluminum + + align:start position:0% +um dosed the pond with alum aluminum + + + align:start position:0% +um dosed the pond with alum aluminum +oxide right + + align:start position:0% +oxide right + + + align:start position:0% +oxide right +to sequester the phosphorus that's in + + align:start position:0% +to sequester the phosphorus that's in + + + align:start position:0% +to sequester the phosphorus that's in +the sediment so that binds pretty + + align:start position:0% +the sediment so that binds pretty + + + align:start position:0% +the sediment so that binds pretty +strongly to the phosphorus + + align:start position:0% +strongly to the phosphorus + + + align:start position:0% +strongly to the phosphorus +the phosphorus no longer leeches up off + + align:start position:0% +the phosphorus no longer leeches up off + + + align:start position:0% +the phosphorus no longer leeches up off +of the bottom + + align:start position:0% +of the bottom + + + align:start position:0% +of the bottom +um now that was a big operation that was + + align:start position:0% +um now that was a big operation that was + + + align:start position:0% +um now that was a big operation that was +a big operation so they're trying a + + align:start position:0% +a big operation so they're trying a + + + align:start position:0% +a big operation so they're trying a +number of different ways to keep the + + align:start position:0% +number of different ways to keep the + + + align:start position:0% +number of different ways to keep the +water quality of the lake + + align:start position:0% +water quality of the lake + + + align:start position:0% +water quality of the lake +excuse me + + align:start position:0% + + + + align:start position:0% + +yes yes yes yeah he gets an anaerobic + + align:start position:0% +yes yes yes yeah he gets an anaerobic + + + align:start position:0% +yes yes yes yeah he gets an anaerobic +hypolining and then you have + + align:start position:0% +hypolining and then you have + + + align:start position:0% +hypolining and then you have +high iron phosphate and it's when you + + align:start position:0% +high iron phosphate and it's when you + + + align:start position:0% +high iron phosphate and it's when you +have turnover you have these algal + + align:start position:0% +have turnover you have these algal + + + align:start position:0% +have turnover you have these algal +blooms + + align:start position:0% +blooms + + + align:start position:0% +blooms +there's a spring bloom and a fall bloom + + align:start position:0% + + + + align:start position:0% + +yeah 60 feet yeah + + align:start position:0% + + + + align:start position:0% + +so so again the monitoring that we have + + align:start position:0% +so so again the monitoring that we have + + + align:start position:0% +so so again the monitoring that we have +going on are + + align:start position:0% +going on are + + + align:start position:0% +going on are +our vertical sampling this way we have a + + align:start position:0% +our vertical sampling this way we have a + + + align:start position:0% +our vertical sampling this way we have a +few multi-level samples that go out + + align:start position:0% +few multi-level samples that go out + + + align:start position:0% +few multi-level samples that go out +under the lake at different levels this + + align:start position:0% +under the lake at different levels this + + + align:start position:0% +under the lake at different levels this +way + + align:start position:0% +way + + + align:start position:0% +way +we have these diffusion samples which i + + align:start position:0% +we have these diffusion samples which i + + + align:start position:0% +we have these diffusion samples which i +don't know if i explain that very well + + align:start position:0% +don't know if i explain that very well + + + align:start position:0% +don't know if i explain that very well +but they're sort of passive and you + + align:start position:0% +but they're sort of passive and you + + + align:start position:0% +but they're sort of passive and you +leave them there + + align:start position:0% +leave them there + + + align:start position:0% +leave them there +we did this because we were concerned + + align:start position:0% +we did this because we were concerned + + + align:start position:0% +we did this because we were concerned +that anytime you pump a water sample you + + align:start position:0% +that anytime you pump a water sample you + + + align:start position:0% +that anytime you pump a water sample you +disturb the flow + + align:start position:0% +disturb the flow + + + align:start position:0% +disturb the flow +and so these are set up in very close + + align:start position:0% +and so these are set up in very close + + + align:start position:0% +and so these are set up in very close +intervals these balls are all stacked so + + align:start position:0% +intervals these balls are all stacked so + + + align:start position:0% +intervals these balls are all stacked so +we can see very detailed gradients + + align:start position:0% +we can see very detailed gradients + + + align:start position:0% +we can see very detailed gradients +because we're trying to figure out where + + align:start position:0% +because we're trying to figure out where + + + align:start position:0% +because we're trying to figure out where +does all the reaction take place some of + + align:start position:0% +does all the reaction take place some of + + + align:start position:0% +does all the reaction take place some of +the chemists say + + align:start position:0% +the chemists say + + + align:start position:0% +the chemists say +the phosphorus is going to come all the + + align:start position:0% +the phosphorus is going to come all the + + + align:start position:0% +the phosphorus is going to come all the +way up through the elemental iron until + + align:start position:0% +way up through the elemental iron until + + + align:start position:0% +way up through the elemental iron until +it gets to the rusty part at the top + + align:start position:0% +it gets to the rusty part at the top + + + align:start position:0% +it gets to the rusty part at the top +and the barrier only had to be an inch + + align:start position:0% +and the barrier only had to be an inch + + + align:start position:0% +and the barrier only had to be an inch +thick but the bottom three feet is + + align:start position:0% +thick but the bottom three feet is + + + align:start position:0% +thick but the bottom three feet is +worthless others are saying no it'll + + align:start position:0% +worthless others are saying no it'll + + + align:start position:0% +worthless others are saying no it'll +happen + + align:start position:0% +happen + + + align:start position:0% +happen +at depth and we don't know um + + align:start position:0% +at depth and we don't know um + + + align:start position:0% +at depth and we don't know um +so um anyway so that's + + align:start position:0% +so um anyway so that's + + + align:start position:0% +so um anyway so that's +those are the various monitoring methods + + align:start position:0% +those are the various monitoring methods + + + align:start position:0% +those are the various monitoring methods +except for one other + + align:start position:0% +except for one other + + + align:start position:0% +except for one other +the other method \ No newline at end of file diff --git a/O92M9n8uIGY.txt b/O92M9n8uIGY.txt new file mode 100644 index 0000000000000000000000000000000000000000..9578a49773fa2bda07917499e27e4c2820ea66de --- /dev/null +++ b/O92M9n8uIGY.txt @@ -0,0 +1,3426 @@ +The following +content is provided + +under a Creative +Commons license. + +Your support will help MIT +OpenCourseWare continue + +to offer high quality +educational resources for free. + +To make a donation or +view additional materials + +from hundreds of MIT courses, +visit MIT OpenCourseWare + +at ocw.mit.edu. + +PROFESSOR: OK. + +First, welcome everybody +and good afternoon. + +So the question is about +the master equation. + +We know is that the +most general master + +equation has to have +the Lindblad form. + +And the Lindblad form +has a jump operator + +which is providing dissipation. + +In its simplest +case, a jump operator + +is just the sigma minus operator +for spontaneous emission, which + +takes us from the excited +state to the current state. + +And when we have the Linblad +form, the jump operator + +and it's commission conjugate, +like sigma plus, sigma minus, + +appear on the right-hand +side of the master equation + +with the statistical operator +here, here, and in the middle. + +There are plus-minus +signs in factors of two. + +So I don't have a +intuitive explanation + +where the factors come from. + +They come from the derivation. + +But you have a question +about it, Nancy? + +AUDIENCE: So after +writing the Linblad form, + +we get gamma [INAUDIBLE], which +we are saying for the r dot + +vector, we were +writing [INAUDIBLE]. + +And we said that +they are directly + +coming from the first one? + +PROFESSOR: Yes. + +So let's go right here. + +That's actually what we +were going to discuss today. + +We want to discuss, today, +solutions of the optical Bloch + +equations. + +And just to remind you, we +derived a master equation + +for the density matrix. + +And this master equation, +through the interaction + +with the reservoir, +is acting a term + +to the Hamiltonian evolution. + +And this is showing right here. + +These are the interactions +with the reservoir. + +And in the case of the +optical Bloch equation + +and spontaneous +emission, we have + +only one Lindblad +operator, which + +is Lindblad operator, +sigma minus, + +for spontaneous emission. + +So this here is +the master equation + +for the two-level system +interacting with a vacuum + +through spontaneous emission. + +And by substituting the +two-level density matrix, + +has three non-trivial +components-- sure, it's a 2 + +by 2 matrix, but the +craziest one-- and so + +we can transform from the matrix +elements of the density matrix + +to three other coefficient, +which come in very handy, + +because they allow a simple +geometric interpretation. + +And this is the Bloch vector. + +And so the master equation, +which is shown here, + +turns into a differential +equation for the Bloch vector. + +And those two equations +are identical, + +we've just done +those substitution. + +But your question is now about-- + +AUDIENCE: Plus gamma, because +we have negative gamma over 2, + +which is from the +first and last term. + +But the gamma term should +be positive, right? + +PROFESSOR: This one here? + +AUDIENCE: No. + +PROFESSOR: This one? + +AUDIENCE: Yes. + +Because that's negative gamma +over 2 times negative 2. + +PROFESSOR: No. + +I mean, first of all, this +is a differential equation + +for r dot. + +OK. + +This is a differential +equation for the Bloch vector. + +And we have here three +different relaxation rates, + +which are gamma, gamma +over 2, and gamma over 2. + +And they are all +negative, because they + +are relaxation rates. + +This here is not +a perfecter of r. + +It is sort of a constant. + +And it means, in the +long time limit-- I mean, + +what happens if you have a +system which spontaneously + +decay after a while? + +The r vector is not 0. + +The r vector is hanging down. + +The system is in +its ground state. + +And this is exactly that. + +Wait. + +Am I r dot? + +Yes. + +The effect is the system, +the differential equation, + +has to relax towards +the equilibrium. + +You can actually +re-write this equation, + +r dot equals a matrix times +r minus r equilibrium. + +So here is the matrix of +the optical Bloch equation. + +So if you re-write that that +r dot is the matrix times r + +minus r equilibrium, +then r equilibrium times + +the matrix gives +something constant. + +And this is exactly this here. + +But it's a +mathematical identity. + +Just look at it. + +There is no assumption. + +It's an exact re-writing +of the equation. + +So it is this +equation which will + +be in the focus of our +attention not only today, + +but also when we talk +about light forces. + +The first thing we +did is we wanted + +to discuss the Mollow triplet. + +And just as a reminder, +we have talked about, + +at the beginning +of last class, we + +talked about the fluorescence. + +An atom is excited by +mono-chromatic laser light. + +And at low intensity, +a delta function + +emits exactly the same +frequency of light + +which is provided +by the laser light. + +So the incoming and +outgoing photons + +have exactly the same frequency. + +And this is simply a consequence +of energy conservation. + +But at higher intensity, +we have sidebands. + +And we understand +intuitively that we + +have sidebands because the +system is Rabi oscillation. + +So same, classically, +we have an emitter + +which has some modulation +that creates sidebands. + +But is rather easy +to understand is, + +by diagonalizing +the 2 by 2 matrix, + +we find that we have a splitting +of excited state with n photons + +and grounds it with +n plus 1 photons. + +So we have sort of a +plus and minus state. + +And if we look at the +possible transitions, + +we immediately find +the explanation + +for the Mollow triplet. + +There are three +different frequencies + +which can be emitted +in transitions + +between rest states. + +What is much more subtle, +what cannot be obtained from + +a preterbative +treatment, is the width, + +how wide are those peaks +in the Mollow triplet. + +And there is tens +and tens of pages + +in atom photo interaction. + +But at least, for +two limiting cases, + +I could show you what the width +of the peak is by first saying, + +if you have delta +equals 0 and g equals + +0, the matrix, which +determines the dynamics, + +has three eigenvalues, +gamma over 2, gamma over 2, + +and gamma. + +And now, if we detune, we +add a rotation along z. + +If you drive the system strong, +it corresponds to rotation + +around x. + +You probably +remember, from 8.421 + +the spin in a magnetic field. + +It rotates. + +In a frame, rotating +with omega, it + +rotates at the detuning delta. + +But if you drive it, we make +it flip along the x-axis. + +So we find exactly that here. + +And then, it's an intuitive way +to sort of matrix, if you want, + +solve the matrix mathematically. + +But intuitively, what happens +is, if you have a z-rotation, + +we don't change in +this eigenvalue. + +And the rotation is just +aiding i omega-- omega + +is the rotation-- to x and +y, because x and y are now + +rotating. + +So therefore, we obtained +that, in the case of detuning + +the z-rotation, we have minus +gamma, minus gamma over 2, + +minus gamma over 2. + +And here, what appears here +is the rotation frequency. + +And then, if you rotate around +the x-axis, then, of course, + +nothing happens, but what +used to be the x-axis. + +So we get one eigenvalue +with minus gamma over 2. + +But the y and z +eigenvector are rotated. + +And hand-wavingly, +I can tell you. + +But you can show +it mathematically + +that this means the two +new eigenvectors have + +the average of those +two damping terms. + +And this is 3/4 gamma. + +So at least, for the two +cases for large detuning + +and strong drive, I was, with +a little bit of intuition, + +showing you and +deriving for you where + +the non-trivial bits of the +Mollow triplet comes from. + +So I hope you're, +at least, impressed + +that these optical Bloch +equations are powerful + +and allow us to make +predictions which + +would be difficult +to obtain otherwise. + +Any questions about that? + +About the Bloch vector, +the differential equation, + +and the spectrum of +the immediate light? + +OK, we want to now discuss one +other aspect, which is actually + +fairly simple. + +We want to discuss +steady state solution. + +For the steady state solution, +we just go to the differential + +equation and say, the +left-hand side is 0. + +That immediately gives us a +solution for the Bloch vector. + +It gives us a Lorentzian. + +But for strong drive, +it has a term here, + +which we will +immediately realize + +that this gives us +power broadening. + +And then the steady state +Bloch vector is g delta, + +g gamma over 2, delta square +plus gamma square over 4. + +So we can now use this +solution for steady state + +and discuss everything we want +what happens in steady state. + +So one question is, if +you have an atom laser + +beam in steady state, how +much light is absorbed? + +Well, the basic equation is, +if you have a charged q which + +moves in an electric field, +that means work is done. + +So therefore, the absorbed +power is related to that. + +And we can now combine q dr/dt. + +And this is nothing +else than the derivative + +of the dipole moment. + +And then we calculate +the average. + +So with that, we find the +result they the absorbed + +power is given by-- +just one second-- e0? + +Yeah. + +We express now e0 by +the Rabi frequency. + +And h bar appears in omega. + +But the important thing is that +we need now the dipole moment + +or the derivative of +the dipole moment. + +And the dipole moment is +given by the coherences + +of the density matrix. + +And that is, if you look +at the substitution, + +is the x and y component of +the optical Bloch vector. + +But now what we +need, of course, we + +need only the component of +the dipole moment, which + +gives a non-vanishing +term with cosine omega t. + +That means, what we +need is-- I mean, + +that's like an +harmonic oscillator. + +The component of +the motion which + +is responsible for +absorption is the one + +which is in quadrature, which is +assigned only the d-component. + +And that, you have to go +back and look by inspection. + +But this is exactly what the +y-component of the Bloch vector + +does for us. + +It will become important +later on for optical forces. + +So we have the +optical Bloch vector. + +We are in the rotating frame. + +And the one component, +which is the x-component, + +is in phase with the light. + +And the y-phase is 90 degree +out of phases in quadrature. + +And for absorption it's, of +course, the in quadrature + +component which is +relevant and which + +determines light scattering. + +OK, this is the absorbed light. + +And we don't measure +power in watt, + +we measure power in the +number of absorbed photons. + +This is the natural unit here. + +And for that, we have to divide +the expression by h bar omega. + +And that means now that the +number of photons absorbed + +per unit time is +given by the Rabi + +frequency and the y-component +of the Bloch vector. + +Well, we can ask +another question + +and ask, what is the +number of emitted photons? + +Well, the number +of emitted photons + +is related to the population +in the excited state. + +We take the population +in the excited state + +and multiply with gamma. + +This is spontaneous emission +out of the excited state. + +Now, the excited state can be-- +the excited state population, + +you have to look up +at the substitution, + +but is related to +the z-component + +of the optical Bloch vector. + +To remind you, the +z-component is the difference + +of population between +excited and ground state. + +But the sum of the two is one. + +So therefore, this is now +the excited state population. + +And here is our +steady state solution. + +Here is our steady state +solution for the z-component. + +And by using that +now, we find that we + +have the result with the +Lorentzian denominator. + +And what we have here is +gamma g square over 4. + +And now, of course, +if you compare + +that with the +solution for our y, + +for the number of absorbed +photons, you find-- well, + +it shouldn't come +as a big surprise-- + +that the number of absorbed +photon in steady state + +is equal to the number +of emitted photon. + +So this is one case, one +important part of the solution. + +And I should have shown +that to you earlier. + +When we look at the +two components, the x + +and y-component, +the y-component is + +absorbed, if it is Lorentzian. + +Whereas, the x-component +is dispersive. + +Just by inspection if these two +expressions, here is a delta. + +And the delta makes the +x-component anti-symmetric. + +And the y-component is symmetric +with respect to the origin. + +So what we see here is +we have a Lorentzian. + +The Lorentzian has a natural +line broadening by gamma. + +So the full width +at half maximum + +is gamma, but only in +the limit of 0 drive. + +When we drive it, we have +an additional broadening, + +which is called +power broadening. + +So for absorption, the +full width at half maximum + +is 2 times gamma square +over 4 plus g square over 2. + +And this last term goes by +the name power broadening + +or saturation broadening. + +Just to avoid common confusion, +if you go to very high power, + +that least term +doesn't play a role. + +How does the line width scale +with power in power broadening? + +Linear in power? + +Quadratic in power? + +Square root of power? + +AUDIENCE: Square root? + +PROFESSOR: Square root of power. + +Yeah. + +So in that sense, +yes, power broadening + +only goes to the +square root of power. + +It's, in essence, +the Rabi frequency. + +If you drive the system +at the Rabi frequency, + +it gets power broadened +by the Rabi frequency. + +And I think that's a pre-factor +which is 2 or square root 2. + +But in essence, power broadening +scales with the Rabi frequency. + +So let us quickly +discuss the case + +when we go to very high power, +very high Rabi frequency. + +At that moment, you can just see +it in the solution on the page + +above. + +The z-component of the optical +Bloch vector becomes 0. + +That means there is no +population difference + +between excited and +ground state anymore. + +We often describe the +limit of high power + +by introducing a +saturation parameter, which + +is defined here. + +Saturation is discussed +in more details in Part 1 + +of the course. + +But I want to relate +it here to the solution + +with the optical Bloch vector. + +The z-component, which +is the difference + +between ground and +excited state population, + +now has a very simple +form, 1 over 1 plus s. + +The population to be in +the excited state is 1/2. + +That's what we get +at infinite power. + +And then, if the +power is finite, + +it is multiplied by +s times s plus 1. + +In the power broadened line +width is the natural line + +width, which gives +the line width + +in the limit of +low power, and then + +you multiply with the +square root 1 plus s. + +So what does it mean to have +a saturation parameter of 1? + +Well, if you just look +how it was defined, + +if you have the ground and the +excited state at a saturation + +parameter of-- first, at +a saturation of infinite, + +you have 50-50 population. + +And at a saturation parameter +of 1, you are 1/2 way to 50-50. + +That means you have +3/4 population here + +and 1/4 population there. + +So at this case, the number of +photons emitted per unit time, + +which is always given +by this formula, + +becomes now gamma over 4. + +So at a saturation +parameter of 1, + +the emission rate +is gamma over 4. + +At a saturation +parameter of infinity, + +the spontaneous emission +rate is gamma over 2. + +Any questions about +steady state solution? + +[INAUDIBLE]? + +AUDIENCE: So what +we derived right now + +is a spontaneous emission rate. + +Does the optical Bloch +equation say anything + +about the stimulated emission? + +Or is that the fact that it +just doesn't have [INAUDIBLE]? + +PROFESSOR: Stimulated emission +is built in the optical Bloch + +equations for negligible damping +contained Rabi oscillation. + +And Rabi oscillation is +the stimulated emission. + +So this is being built in. + +However, it seems to be +a describing the drive + +field by a classical +field by a Rabi frequency. + +We are not really +accounting for the number + +of photons exchanged with that. + +So in a way, the +driving field is always + +treated in the +undepleted approximation. + +It's a C number. + +But in the drive through +system, but of course, + +you can immediately lead +from the Rabi oscillation + +the exchange of excitations +between the atomic system + +and the drive field. + +So yes, the optical Bloch +equations contains that, + +but not in the photon picture. + +AUDIENCE: If you have +Rabi oscillations, + +you can kind of guess +that, every time you + +go down you +simulated the events. + +In space, say, you don't +have Rabi oscillations. + +Can you still somehow +extract the rate? + +PROFESSOR: I hope the question +we answer will become crystal + +when we discuss quantum +Monte Carlo simulations. + +AUDIENCE: OK. + +PROFESSOR: In quantum +Monte Carlo simulation, + +we have an ensemble of atom. + +And the atoms all do +Rabi oscillations. + +But in steady state, +they do it out of phase. + +So you have atoms +in your ensemble + +which, at a given time, absorb. + +And others emit in +a stimulated way. + +And the effect cancels +out in steady state. + +Other questions? + +Yes? + +AUDIENCE: So you're +saying, in steady state, + +they kind of de-cohere. + +And you don't have any net +change in those populations. + +Do you still get +the triplet lines + +if you don't have a modulation +of your intensity beam? + +PROFESSOR: Yes. + +Absolutely. + +The Mollow triplet is a +feature in steady state. + +And maybe let me explain +that, because it's + +an interesting discussion. + +What will happen is, in +steady state in your ensemble, + +you don't have +Rabi oscillations. + +But if you would +look at one atom, + +you see Rabi oscillations. + +It's just when you average over +all atoms in your ensemble, + +the phase of the Rabi +oscillation has averaged out. + +So in other words, for +instance, what would happen + +is the following. + +If you take a steady +state solution + +and you ask, what is the dipole +moment as a function of time + +in steady state, you +will find that this is 0. + +So you would then +ask, hey, where + +is the light emitted, because +isn't the light emitted + +by a time-dependent +dipole moment? + +What you really +have to do is, when + +you want to study light +emission in steady state, + +you can't look at +expectation values + +because they're not changing +as a function of time. + +What you have to do is you +have to look at the correlation + +function. + +And the correlation +function sort of + +tells you-- let me just use +it for Rabi oscillation. + +If one atom is in the excited +state, a Rabi period later, + +it would be again in +the excited state. + +So although you are +in steady state, + +you have correlations because, +if you look at your ensemble + +and see there is a fluctuation +where the atom is excited, + +you will actually find +a co-related fluctuation + +a Rabi period later. + +So in steady state, when +you want to study dynamics + +like the Mollow +triplet, you should not + +look at the solution +for the dipole. + +You should look for the +solution of the correlation + +of the correlation function. + +And I made this cryptic +remark on Wednesday + +that this correlation function +follows the same differential + +equation as the +expectation value. + +Therefore, when I try to +discuss for you the line + +width of the Mollow +triplet, I simply + +use the matrix for +the Bloch vector + +knowing that it is the same +matrix, the same differential + +equation which will describe +this correlation function. + +But it is important here +that, in steady state, + +the average values are 0, +but we have fluctuations. + +And it is the +fluctuations which emit + +the light, the fluctuations +which emit the Mollow triplet. + +And fluctuations are described +by quantities like this. + +So it's a little bit beyond what +I want to discuss in the book, + +but atom photon indirection has +a wonderful chapter on that. + +Other questions? + +There is another important case +of the optical Bloch equation, + +which is the weak excitation +limit, which is simple. + +But I've already asked you to +look at it in your homework + +assignment. + +OK, let's now come to the +third aspect of master equation + +solutions of optical +Bloch or master equation. + +And these are damped +vacuum Rabi oscillations. + +Yes. + +I really like this +example in this chapter, + +so I hope-- well, I think +we have many highlights, + +but this is a +really nice example. + +I learned it from +Professor [? Schwan ?] + +when he introduced it. + +And what I like +about it is I can + +use it to show you what +other Lindblad operators may + +be important. + +So you suddenly understand, +in a bigger context, + +what the master equation is. + +And then we continue +with an atomic cavity. + +And the damping is no longer +by spontaneous emission. + +The damping is by photons +sneaking out of the cavity. + +So we really learn +something which + +is similar to optical +Bloch equation, + +but in another context. + +And often, if you see two +different realizations + +of similar physics, +you maybe realize more + +what is more generic and +what is special for instance + +of spontaneous emission, +so I really like that. + +But also, I found +that this example + +allows me to introduce to you +the concept of the quantum Zeno + +effect and the concept +of atypical elimination + +of coherences. + +So it's a wonderful +example which connects us + +with a number of +really neat concepts. + +So with that promise, +let me remind you + +that, in the master +equation, when we derived it, + +we got an exact expression +when we did second order + +perturbation theory. + +And the structure which came +was this double commutator + +between the interaction operator +and the steady state operator. + +Just to remind you, in the +interaction picture-- first + +in the non-interacting, +in the normal picture, + +the derivative of the density +matrix is a commutator with h. + +In the interaction +picture, it's a commutator + +with v with the interaction. + +But when we iterate an +equation to second order, + +we plot the first result +into the equation. + +Then we get, in second +order, this structure. + +And if I, by expanding +the commutator, + +we obtain the +following structure. + +And that gave rise +to the Lindblad form + +of the master equation, which +is rho dot equals a Hamiltonian + +part. + +But then we have now a +sum, v, the interaction + +with the environment, +can be a sum of mu + +dot b and b-- and so +an external b field + +times magnetization and dipole +moment times an electric field. + +It can have a number of terms. + +And therefore, in general, we +have more than one Lindblad + +operator. + +But the structure +is always given + +by this commutator in +the following form. + +OK. + +So we have this +general derivation. + +But until now, we +have only looked + +at a system which +is a simple atom. + +And the environment +was the vacuum. + +So this is our environment. + +And also, the environment was +always in the vacuum state. + +So these were our assumptions. + +And that means that the +only Lindblad operator, + +the only jump +operator in this sum + +is sigma minus for +spontaneous emission. + +And by inserting +this jump operator + +into the Lindblad form +of the master equation, + +we find the optical +Bloch equation. + +But now let's do cavity QED. + +And there are lots +of experiments + +going on in the research +group of Professor Vuletic. + +And in this situation, +our system is actually not + +just the atoms, it's the +atoms and a single mode + +of the cavity. + +This is our system. + +And the environment +are all other modes. + +So in other words, +the atoms interacting + +with a single mode of the +cavity, this is our system. + +And the environment +is now accessed + +by emitting-- the +atom is emitting. + +Or there are photons +leaking out of the cavity, + +because the cavity mirrors do +not have 100.0% reflectivity. + +I will immediately reduce +it to one Lindblad operator. + +But we could now say that this +system, in its full glory, + +has four different +Lindblad operators which + +provide dissipation, +which provide coupling + +to the environment. + +The first one is simply +what we had before, + +spontaneous emission. + +However, if we allow that +the environment is thermal, + +we have to multiply. + +Well, whenever you have +emission and you have already + +population in a +mode, and thermal + +is a number of thermal photons +in every mode, on average, + +then you have an extra bosonic +or photonic stimulation term. + +That's stimulated emission, +but not by the laser beam. + +It's now stimulated emission +by a thermal occupation + +of all the other modes. + +So just assume, +for that purpose, + +that you have a cavity here. + +But the cavity is now +in a black body cavity. + +And everything, all +modes in the vacuum, + +are no longer vacuum modes. + +They are occupied +within thermal photons. + +Of course, if this +is the case, we + +have also the opposite effect. + +You can see by +unitality, namely, + +that we can have-- +oops, n should be-- + +but that we have an +absorption process. + +We absorb a photon from +the thermal background. + +But now, we have +two more processes. + +And this is photons +leaking out of the cavity. + +When a photon leaks out of +the cavity, this leakage + +is not coupled to the atom, +it's coupled to the mode. + +We describe the mode +by a mode operator, a. + +So now, the leakage +out with the rate, + +kappa, is presented by that. + +But in the case of +thermal photons, + +we have stimulation by +the thermal photons. + +And also, if we have +thermal photons, + +photons cannot only +leak out of the cavity, + +they can also leak +into the cavity. + +So we have assumed here that +we have n thermal photons + +in each mode of the environment. + +So in other words, if you +want to look at, for instance, + +Serge Haroche does experiment +in the wonderful experiments + +in the microwave domain. + +He has cavities at, I think, +gigahertz frequencies. + +And even at cryogenic +temperature, + +there are occasional thermal +photons in this mode. + +But you are now +expert enough that you + +would know how to +set up a master + +equation for that situation. + +But I want to discuss +simple limiting cases. + +So I think you are +glad to hear that we + +are choosing 0 thermal photons. + +So therefore, we assume we +have a cavity in vacuum. + +And therefore, we only need the +Lindblad operators, L1 and L2. + +And we want to describe the +system which has only one + +x, which has, maximally, +one excitation. + +We try to keep the +density matrix small, + +so we only want to +consider three states. + +So when I said there +is one excitation, + +it is, of course, +the state which + +has no photon in +the excited state. + +The state two is we have the +ground state and one photon. + +And those two states are +coupled by the cavity. + +And since I really want to +discuss the simplest case which + +already illustrates all +the concepts I want to do + +is they are coupled by the +vacuum Rabi oscillation. + +And we have discussed +vacuum Rabi oscillation + +in part one of the course. + +But it's very simple. + +It's just two levels coupled. + +It's a 2 by 2 matrix, +so this is something + +you are familiar with. + +But now, the master equation, +the Lindblad operator + +bring in the third +level, which is + +the ground state +without photons. + +And this can happen in two ways. + +One is spontaneous emission. + +The excited state emits, +but not into the cavity. + +It emits to the side. + +So spontaneous +emission can take us + +down here, or when the +excitation is in the cavity. + +We have one photon +in the cavity, + +this photon can leak out. + +And the rate that is kappa. + +And since we have talked +about spontaneous emission + +so much with the +optical Bloch equation, + +we want to discuss now the case +where gamma can be neglected. + +And we want to +understand what happens + +when the only +dissipation of the system + +comes by photons leaking +out of the cavity. + +Any questions about the +system and the motivation? + +So our system is now +an atom with a cavity. + +The environment is a vacuum. + +But the process of +dissipation relaxation + +is no longer +spontaneous emission, + +it is the photon leaking +out of the cavity. + +And this realizes +different physics. + +And I hope, by experiencing +these different physics, + +you have sort of a nicer +picture what is dissipation + +in an open system +and what is similar, + +but what is also different +or spontaneous emission. + +[? Koren? ?] + +AUDIENCE: If you're considering +only kappa, isn't there + +an equivalent process of +order kappa that takes you + +to ground of two +photons in the cavity? + +Don't you have to consider +that state as well? + +That term would be of +order kappa as well. + +PROFESSOR: So great. + +The question is I +restrict the Hilbert + +space to maximally +one excitation. + +So this is how we start out +with our differential equation. + +AUDIENCE: Oh, this +isn't in a thermal bath? + +I thought we were +assuming we had a-- + +PROFESSOR: Oh, sorry. + +I first made +everything complicated. + +But then I said, now, +let's make it simple. + +We assumed the +thermal bath is 0. + +So we reduced-- + +In a way, yes, I told you here +are four Lindblad operators, + +and you can describe +everything you want. + +But then I said, hey, +two of them become 0, + +because we eliminate +the thermal bath. + +And now I make the approximation +that spontaneous emission + +is negligible. + +And now we are back +to the situation + +which is nice for +classroom discussion. + +We've only one +term left, and this + +is the leaking of the +photon out of the cavity. + +So I will show to +you what happens. + +But ultimately, when we make +the cavity better and better + +and kappa smaller and smaller, +I will say, wait a moment. + +We now have to check that +our solution is still + +consistent with our assumption +that spontaneous emission can + +be neglected. + +So that's sort of +what you want to do. + +Yes. + +Let's just get two more pages. + +OK. + +So what we want to +do is we want to look + +for the dynamics of the system. + +We start out in state one. + +So we inject one excited +atom into the cavity. + +And what we want +to learn now is-- + +and it has a lot of +interesting physics in it-- + +what will happen as a function +of this new dissipation, kappa. + +Well, qualitatively, it +should be pretty clear. + +If kappa is 0, we have +vacuum Rabi oscillation + +between state one and state two. + +If you then put a little +bit kappa into the system, + +you have a Rabi oscillation, +but they are getting damped. + +And like in any oscillator, +if you crank up the damping, + +you go into an +overdamped regime. + +And this is exactly what +the equations give us, + +Rabi oscillation, damped +Rabi oscillation, and then + +overdamped regime. + +And actually, the most +interesting regime for us + +will be the overdamped regime. + +That's something we +haven't encountered. + +But let me just, before +we go there, write down + +the master equation for you. + +So without the photon +leaking out of the cavity, + +we have the following terms. + +Without the photon leaking +out of the cavity, of course, + +state three is not involved. + +We simply have Rabi oscillation +between state one and state + +two. + +And this is actually also like +the optical Bloch equation. + +Without damping, it's simply +the Jaynes-Cummings model. + +Minus, that's this. + +And for the coherences, +we get omega 0 + +rho 1, 1 minus rho 2, 2. + +But now, we put in +the terms with kappa. + +The state, which is +the state two, which + +is the ground state +with the photon, + +has now a damping term, because +the photon can leak out. + +We get, of course, an +equation for the ground + +state, the population, +the photon leaks out. + +And we populate state three. + +And the damping also +affects the coherences. + +And the form of the master +equation, the Lindblad form, + +gives us the following +damping term. + +So there are two +new concepts which + +I promised you to introduce. + +One is the idiopathic +elimination of coherences. + +And the second one is +the quantum Zeno effect. + +So first of all, if you look +at the differential equation, + +and when kappa is small, +in particular, kappa + +is smaller than 2 times +the vacuum Rabi frequency, + +then the population to be in the +excited state, which is rho 2, + +2, undergoes Rabi oscillation. + +And those Rabi oscillations, +this population + +is damped by e to +the minus kappa t. + +So what I want to discuss +now is the overdamped case. + +And actually, before +I derive it for you, + +I wanted to ask you +some clicker question. + +I'm afraid I put the books +out, but somebody put it away. + +So nobody took clickers? + +So why don't we just +pass them around? + +And I can already +formulate the question. + +I think you know by now +that I have a preference + +to maybe ask you questions about +really simple quantum physics. + +Quantum physics is sadly +enough that nobody fully + +understands it. + +And we want to improve on that. + +So I want to test your intuition +by looking at the situation. + +We have an excited +state without photon. + +We have a ground state. + +So I want to test your +intuition in the following way. + +We have Rabi oscillations +between two levels. + +The case in the cavity is, it is +Rabi oscillation between state + +two and state one, +but it doesn't matter. + +You can also assume that +it is Rabi oscillation + +between hyperfine levels. + +And the Rabi oscillation +is driven by an RF field. + +And the one thing +we introduce now + +is we introduce damping +kappa to this level. + +But we start out +the system with all + +of the population in this state. + +And in the overdamped case, when +kappa is sufficiently strong, + +then we know an oscillator +will be overdamped + +and will no longer oscillate. + +And in this situation, +the probability + +to be in the initial +state will decay. + +e to the minus kap-- e to the +minus-- how should we call it? + +gamma t. + +So it decays with +the decay rate kappa. + +And my question for you is, +A, B and C, whether the decay + +rate, kappa, is proportional +to the damping rate, gamma? + +Proportional to the +inverse of gamma? + +Or independent of gamma? + +So we've exacted this system. + +The system has possibility +of Rabi oscillation. + +I showed you the +damped Rabi oscillation + +and in the limit of small kappa. + +But now you go to the +overdamped regime. + +And my question is, if +the system is overdamped, + +will this decay rate +increase with kappa? + +Decrease with kappa? + +Or will it be independent +of a damped regime? + +All right. + +OK. + +There's a clear neutrality. + +Let me not yet +discuss the answer. + +Let me maybe try to give +you another problem. + +And you should maybe figure +out if those two problems + +are related. + +I want to ask you now +something simpler. + +There are not three +levels involved, + +there are two levels involved. + +But one of the level +is broadened by kappa. + +Call it an unstable state. + +Because it can decay with +the rate, kappa, and we + +often show something +which is broadened. + +And now we have a matrix element +between the discrete level + +and the broadened state, +which I call omega. + +It's a matrix element +or Rabi frequency. + +And now you should +figure out what + +is the physical +picture which describes + +the coupling of a discrete +initial state to something + +which is broadened. + +It's now the transition rate +from the original state. + +Does the original state decay +with a collectivistic rate, + +which is omega? + +Or is it omega +squared over kappa? + +Or is it none of the above? + +So coupling between two +levels, very, very simple. + +But one level is broadened. + +OK. + +Yes, it's Fermi's Golden +Rule, what I'm asking you. + +This is nothing else +than Fermi's Golden Rule. + +We couple from one level into +some continuum of states. + +If I take one state and +smear it out over a width, + +kappa, the density of states, +the density of modes which + +appears in Fermi's Golden +Rule, is 1 over kappa. + +And Fermi's Golden Rule +tells us that the coupling + +is the matrix element squared +times the density of states, + +which is 1 over kappa. + +So this is nothing else +than Fermi's Golden Rule. + +OK. + +Why don't we come back +to the first question + +now where we have two +discrete levels, maybe + +two hyperfine states, which are +coupled by a Rabi frequency? + +But then one of the +hyperfine states + +decays because there is +some leakage, or we-- + +I don't know-- we interrogate +this state with laser + +beams or such. + +We make it unstable. + +We allow this state to +decay to another state. + +And the question is, if we +make the decay of that level + +stronger and stronger, does +the decay of the initial state + +increase? + +Decrease? + +Or is of that? + +Good. + +So what you have learned here +is that, actually, the more we + +damp the system on this +side, the longer-lived + +is the initial state. + +But it's trivial. + +It's just Fermi's Golden Rule. + +When you couple into a +level which is broadened, + +the coupling becomes weaker and +weaker because, well, that's + +what Fermi's Golden +Rule tells us. + +I want to now derive this +situation for you for our atom + +in the cavity. + +And I will say that this is one +example for the quantum Zeno + +effect. + +But let me already +explain to you + +what the quantum Zeno effect is. + +Zeno is a Greek philosopher. + +And the Greek philosophers +had some deep thoughts + +about the nature of time, +the nature of motion. + +And I think, in the +Greek philosophy-- sorry. + +I didn't go-- I mean, I don't +have a strong background + +in philosophy, but +I think the idea + +is that motion is when +something moves around. + +But it takes some time to move. + +So if you observe +it, it can't move, + +because every time you observe +it, you localize something. + +That's the idea. + +If you see an arrow, the moment +you observe it, it's localized. + +And if you localize something +to often, it cannot move. + +And this is sort of +what you can say here. + +The system wants to +evolve to a second state. + +But kappa can actually +be a measurement process. + +We can just shine a +strong laser on this state + +and figure out has +something arrived here. + +And the more often we look, the +stronger our measurement is, + +the less the system can evolve. + +So a measurement of what +arrives in this state + +slows down the +dynamics to that state. + +And this is called the +quantum Zeno effect. + +It also goes by the name +of quantum Zeno paradox. + +But it's just quantum +mechanics, it's not a paradox. + +In the popular world, it +is sometimes paraphrased + +as if you observe the tea +kettle, the water never boils. + +But you see now +where it comes from. + +OK, so this is the +quantum Zeno effect. + +And we want to now, by +looking at the master + +equation for an +atom in a cavity, + +I want to show you the +limit that it really + +comes out of the +master equation. + +Questions about that? + +OK, so this is the +quantum Zeno effect. + +And well, one of the nicest +papers on the quantum Zeno + +effect-- well, I'm biased here-- +but it was written by my group, + +because we used the +Bose-Einstein condensate. + +We had an RF coupling to +another hyperfine state. + +And then we used a laser beam +and observed the population + +in the final state. + +And we saw that the +effect of the RF drive + +became weaker and +weaker and weaker, + +the stronger we made the +measurement in the final state. + +And this is the reference. + +And our work was the first +quantitative comparison. + +You can now do a +measurement by just + +using a strong laser in, +maybe, every millisecond or so. + +Or you can use a weaker +laser beam continuously. + +So we showed in this work +that the quantum Zeno effect + +is the same, whether you do +a pulsed observation, which + +is a strong measurement, or +continuous weak measurement. + +OK. + +But let's now, after +this short interlude, + +go back to the master equation. + +So our job is now to +solve this master equation + +for the limit of strong damping. + +And what we will +find, actually, is + +we will find both the quantum +Zeno effect and another tidbit. + +We will also find +the Purcell effect, + +which is enhanced spontaneous +emission to a cavity. + +Now the way how we solve +this master equation + +in this limiting +case is by the method + +of idiopathic elimination +of coherences. + +And let me explain it to +you with that equation. + +What we have here is the +derivative of the coherences. + +And when you look at +the right-hand side, + +the derivative of the coherences +is kappa, a damping terms, + +times the coherence. + +Well, if you have +an equation which + +says a dot equals minus +strong damping times a, + +you have a very rapid +exponential damping. + +The system immediately +gets into an equilibrium. + +And the equilibrium is +given by the first term. + +So if you have a situation that +the population do not rapidly + +change, then this +equation can be + +written that we have +a very rapid damping. + +And ultimately, the +coherences settle + +to an quasi-equilibrium +value in a time 1 + +over kappa, which is +given by the first term. + +In other words, you +set the time derivative + +of the left-hand side, 0. + +And then the coherences +are expressed + +in terms of the slowly +changing quantity, which + +are the populations. + +So let me repeat. + +If coherences are +rapidly damped, + +we can neglect the +time derivative + +of the left-hand side. + +And at any given +moment, the coherences + +will be given by an expression +which involves the population. + +And if the populations +slowly change, + +the coherences +will slowly change. + +Or in other words, +the coherences + +follow the population. + +And the lag time is, +at most, 1 over kappa. + +And we are in the +limit of strong kappa. + +This principle of +eliminating coherences and we + +simply get a master +equation for population + +is called the idiopathic +elimination of coherences. + +It's also called by Eric +Hargan in his famous work + +about synergy by the principle +that, if you have rapidly + +damped modes, they are +slaved by the slow modes. + +In other words, the rapidly +damped degrees of freedom + +follow the slow +degrees of freedom. + +And this is what I just said, +that the instantaneous value + +of the coherences is always +given by the population. + +So let me just write that down +and see where it takes us. + +So we have the +situation that we want + +to now look at the +case of strong damping. + +This is the overdamped case. + +And we use now the method +of idiopathic elimination + +of coherences, because +they are rapidly damped. + +And there is a +wonderful discussion + +about this method in +Atom-Photon interaction. + +It's the Exercise +18 on page 601. + +So mathematically, +what we assume + +is that the population +vary slowly. + +For instance, they vary +at the Rabi frequency. + +So therefore, we can say that +over the rapid time evolution + +of the coherences-- rho +1, 2 plus rho 2, 1-- + +so this is the rapid time +evolution of the coherences. + +But for times which are on +the order of 1 over kappa, + +the population are not changing. + +The population change over +the much longer time scale, + +which is the period of +the Rabi oscillation. + +So therefore, for +the short time scale, + +I can sort of pretend that +this term is constant. + +And for obvious reasons, let +me now call this constant term, + +or slowly varying term, it is, +at least for short time scales, + +the equilibrium value. + +So the way how we +should read it is + +that the coherences +will very, very rapidly + +damp to this equilibrium value. + +And this equilibrium +value was given + +by the population, +which may slowly change. + +But that means, now, by +eliminating coherences, + +we obtain a rate equation +for the populations only. + +So therefore, if you +neglect short transients + +over the short +time 1 over kappa, + +the coherences are +always given by + +this quasi-equilibrium +value, which + +is expressed by the population. + +And therefore, we can go to +our master equation, which + +was a master equation +for the of diagram matrix + +elements of the density +matrix, and we can now + +replace the coherences +by an expression which + +involves only population. + +So we get now closed equations +for only the population. + +I'm sort of emphasizing that +because you may have asked + +yourself, when you have the +rate equation a la Einstein, + +with the a and b +coefficient, these are just + +rate equation for populations. + +But here, in our class, we've +always talked about the density + +matrix, how important +the coherences are. + +The coherences are important. + +Without coherences, you would +never absorb or emit light. + +But if the coherences can +be expressed by populations, + +you don't need a differential +equation for them. + +OK. + +So with that now, we +have our master equation + +for the population. + +And by just inserting +that, we find this. + +And we were interested +in the decay of rho 1, 1. + +Or this is also the population +of the atom in the excited + +state. + +If we initially start +where rho 1, 1 is large, + +we're interested in +the initial decay, + +then the population in +the ground state is small. + +And we find, indeed, that +there is exponential decay + +of the initial distribution. + +And the decay rate, +gamma z, gamma cavity, + +is given by this expression. + +So therefore, what we +find is-- but you know it + +by now-- the effect that the +stronger we damp the cavity, + +the smaller, the weaker, is +the decay of the initial state. + +And I've already +explained to you + +that one picture to explain +that is that we have the excited + +state, we have the ground state. + +The ground state +gets damped by kappa. + +And therefore, the +time evolution, + +which is given by the vacuum +Rabi oscillation, slows down. + +OK. + +Yes. + +Any questions? + +So we have now resolved +for gamma cavity. + +We have a result +how the atom decays + +in the presence of the cavity. + +And I want to rewrite this +for you in a very nice way. + +Namely, I want to show +you the famous result + +that, when an atom +emits in a cavity, + +that the atom can decay faster +than the spontaneous decay. + +Because if the cavity +has a resonance, + +the cavity changes the +vacuum around the atom. + +It increases the +density of modes. + +And therefore, there +is a stimulation + +of the atom into the cavity. + +So I don't have to +do any other math + +than just rewriting our result +of gamma cavity in other units, + +in other ways. + +And then we can compare it to +the natural decay of an atom + +without the cavity. + +So what we want to +do now is we want + +to take the cavity-induced +decay of the excited state, + +and we want to compare with +the natural decay rate, gamma. + +So I just have to rewrite +things in a few units. + +The cavity-induced decay is +the vacuum Rabi oscillation + +squared over kappa. + +So let me remind you that +the Rabi frequency is always + +given by an dipole moment +times electric field. + +It's a matrix element. + +Well, there's one of +those factors of 2. + +And H bar keeps +the units correct. + +And in the case of the +vacuum Rabi oscillation, + +the electric field is the +electric field, so to speak, + +of one photon in +the cavity volume. + +And there is a factor +of 2, so this is now + +the volume of the cavity. + +So therefore, the +vacuum Rabi frequency + +is a dipole moment +times 2 atomic resonance + +frequency epsilon 0 h bar v. + +And that means now-- and +this is a nice result-- + +that the cavity-induced decay +is omega 0 square over kappa. + +And I just use the above +result for omega 0. + +And for kappa, I +introduce the Q factor + +of the cavity, which is +the number of oscillations + +before it is damped. + +It's omega over kappa. + +And with that, I can rewrite +the cavity-induced decay + +as 2d squared epsilon +null H bar v times Q. + +And if you remember, from +part 1 of the course, + +or standard textbook result, +that spontaneous decay is + +a dipole moment squared times +frequency to the power 3, + +then we obtain +the famous result, + +which is called the +Purcell factor, namely + +that the decay in +the cavity, compared + +to the decay in free space, +is proportional to the Q + +of the cavity. + +There is a numerical prefector. + +But then, what enters +is the wavelength + +of the photon cubed +over the volume. + +So the case of eta +larger than 1-- + +and it's actually interesting +that this result is completely + +independent of +atomic properties. + +So in other words, every +atom you put in a cavity, + +no matter what its +dipole moment is, + +it will decay with a rate +which is Q times larger. + +There are many ways +how to look at it. + +You can say, if the cavity +consists of two mirrors, + +you create Q mirror +images of your atom. + +And you have sort +of an atom which + +has a Q times stronger +dipole moment. + +And therefore, because the +mirror images also radiate, + +and therefore you get +a Q times faster decay. + +So this limit makes sense in +many, many different pictures. + +And it's a general result +that, if an atom emits + +in a cavity with finesse +Q, you get a Q times + +enhancement of +spontaneous decay. + +So this is called +cavity-enhanced spontaneous + +emission. + +It goes back to Purcell in 1946. + +And you can see the +whole field of cavity QED + +depends on this effect, that you +can enhance spontaneous decay. + +Or it's the opposite. + +If an atom has a +resonance frequency + +between two modes of the +cavity, the spontaneous decay + +is inhibited. + +And this is sort of what +is exploited in cavity QED. + +Let me just conclude +here by saying + +that our assumptions +have to be consistent. + +In our derivation, +we neglected gamma. + +When I said the two +Lindblad operators, + +we only look at the +leakage out of the photon. + +We neglect spontaneous decay. + +So of course, this requires +that eta is larger 1. + +So this is the consistent range +of validity of our result. + +Secondly, we discussed +the limit of overdamping, + +which requires that kappa has to +be larger than the vacuum Rabi + +frequency. + +And therefore, the above +result is valued for large Q. + +Q has to be sufficiently large, +but cannot be larger than this + +value. + +Any questions? + +Nancy? + +AUDIENCE: For kappa, is that +the loss in the cavity-- + +is there any difference +between the loss and the cavity + +because it's a cavity? + +Or the loss is into other +modes of the cavity? + +PROFESSOR: Kappa is the loss. + +You can say kappa is the rate +at which a photon in the cavity + +is lost. + +AUDIENCE: Is lost from +the cavity totally? + +Or is lost into another +mode inside the cavity? + +Is there any difference? + +Is v here just one +mode inside the cavity. + +PROFESSOR: Well, we +have not an element-- + +OK, if the mirror +has imperfections, + +we usually think of light +leaking out of the mirror. + +If the mirror is absorbing +because the coating has + +a tiny little bit +of absorption, you + +know, from the beam +splitter analogy, + +that a small absorption +is equivalent here + +to a small transmission factor. + +Usually, we don't consider +that the light transforms + +from one mode of the +cavity to the other. + +It's either absorbed +or leaking out. + +But if you assume that the +mirrors are not super polished + +and they scatter +light a little bit, + +then you would have a mechanism +that the light in the cavity + +scatters into other modes. + +And all those losses +are summarized + +in one coupling constant, kappa. + +Let me finish the class +today and this week + +by showing to you the recent +nature paper by the Innsbrook + +group. + +We've talked so much +about Lindblad operators. + +And the Lindblad +operators, the dissipation, + +tells us what is the +effect of the environment. + +And usually, you would say, +well, if you have an atom, + +and it interacts +with the environment, + +what is the equilibrium state? + +Well, if you just +have the vacuum, + +the atom goes to +the ground state. + +And the ground state +is the attractor, + +the stable state of the system. + +If you drive the system +with one laser beam, + +the attractor state where +the system goes into + +is the steady state solution +of the optical Bloch equation. + +That all sounds a +little bit boring. + +But in this paper, based on +this theoretical suggestion + +of Peter Zola and an +experimental realization + +with trapped ions at +Innsbrook, they actually + +engineered an environment, +engineered Lindblad operators + +in such a way that +the system of two ions + +was relaxing into a Bell state. + +So you engineer +now the environment + +that therm-- I wanted to say +thermal equilibrium, no-- + +the equilibrium state with the +environment, the dissipation, + +leads to a Bell state. + +Well, it's a little bit +complicated how it is done, + +but I just want to just look at +a few highlighted key messages. + +So the idea is, here, +engineering of dissipation, + +creating experimentally +dissipative operators. + +We usually manipulate quantum +system with Hamilton operators. + +But here, it is manipulated +not by the H operator, + +but by the L operator. + +And so the idea here is to have +an evolution of the density + +matrix, a linear mapping that +the density matrix evolves + +in a certain way. + +I think you'll +recognize partial trace. + +You'll recognize +a few equations, + +a few results which +we have discussed. + +And what you see here is +exactly the Lindblad form. + +And what they did is, by +using a number of laser + +beams in quantum operation, +they designed operators, z, + +jump operators, Lindblad +operators, in such a way + +that the system was damping +out into a Bell state. + +So that seems a new +frontier for research. + +It goes by the title that we +can do quantum simulations, + +using trapped ions and +cold atoms of Hamiltonians. + +But we can also quantum simulate +very special environments. + +Maybe environments +which it would + +be hard to find them +in nature, but they + +are quantum-mechanically +allowed possible environments. + +And they may have +new features which + +have not been explored so far. + +I will add this +paper to the website, + +if you want to +read more about it. + +Any question? + +Then a reminder. + +No class next week. + +Monday is Patriot's Day. + +I'm out of town on +Wednesday, but you + +have a homework to solve. + +I rather feel you should +continue to have a homework + +assignment every +week, because then you + +have more time at the end of +the term for the term paper. + +I always have 10 +homework assignments. + +So when we spread +them out more, there + +is less time left at the end +of the semester for the term + +paper. + +So I decided, since we have +covered enough material, + +we have a wonderful homework +assignment for next week. \ No newline at end of file diff --git a/P7frcB_-g4w.txt b/P7frcB_-g4w.txt new file mode 100644 index 0000000000000000000000000000000000000000..d0d1915b48e4ab541e40f5bb6a94fc31794844be --- /dev/null +++ b/P7frcB_-g4w.txt @@ -0,0 +1,7866 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit MIT open courseware + + align:start position:0% +of MIT courses visit MIT open courseware + + + align:start position:0% +of MIT courses visit MIT open courseware +at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu hi + + align:start position:0% +ocw.mit.edu hi + + + align:start position:0% +ocw.mit.edu hi +everyone I am uh I'm Victor my full name + + align:start position:0% +everyone I am uh I'm Victor my full name + + + align:start position:0% +everyone I am uh I'm Victor my full name +is Victor Coston I'm a third- year PhD + + align:start position:0% +is Victor Coston I'm a third- year PhD + + + align:start position:0% +is Victor Coston I'm a third- year PhD +student I'm in uh cell and uh I work in + + align:start position:0% +student I'm in uh cell and uh I work in + + + align:start position:0% +student I'm in uh cell and uh I work in +systems I do mostly security and + + align:start position:0% +systems I do mostly security and + + + align:start position:0% +systems I do mostly security and +distributed systems and I'll be your + + align:start position:0% +distributed systems and I'll be your + + + align:start position:0% +distributed systems and I'll be your +algorithm ta for this term yay how many + + align:start position:0% +algorithm ta for this term yay how many + + + align:start position:0% +algorithm ta for this term yay how many +people went to lecture + + align:start position:0% + + + + align:start position:0% + +yesterday all right are there any parts + + align:start position:0% +yesterday all right are there any parts + + + align:start position:0% +yesterday all right are there any parts +of the lecture that were particularly + + align:start position:0% +of the lecture that were particularly + + + align:start position:0% +of the lecture that were particularly +unclear that you guys want to go + + align:start position:0% +unclear that you guys want to go + + + align:start position:0% +unclear that you guys want to go +over so that I uh schedule what I talk + + align:start position:0% +over so that I uh schedule what I talk + + + align:start position:0% +over so that I uh schedule what I talk +about in such a way that I'll cover that + + align:start position:0% +about in such a way that I'll cover that + + + align:start position:0% +about in such a way that I'll cover that +more than the parts that are boring and + + align:start position:0% +more than the parts that are boring and + + + align:start position:0% +more than the parts that are boring and +obvious + + align:start position:0% +obvious + + + align:start position:0% +obvious +um can you explain complexity uh + + align:start position:0% +um can you explain complexity uh + + + align:start position:0% +um can you explain complexity uh +equations I took for2 like three years + + align:start position:0% +equations I took for2 like three years + + + align:start position:0% +equations I took for2 like three years +ago + + align:start position:0% + + + + align:start position:0% + +okay what + + align:start position:0% +okay what + + + align:start position:0% +okay what +else thank + + align:start position:0% + + + + align:start position:0% + +you some basic outlines for like writing + + align:start position:0% +you some basic outlines for like writing + + + align:start position:0% +you some basic outlines for like writing +proofs uh relevant to like the presets + + align:start position:0% + + + + align:start position:0% + +right + + align:start position:0% + + + + align:start position:0% + +okay anything + + align:start position:0% + + + + align:start position:0% + +else okay we're going to get started + + align:start position:0% +else okay we're going to get started + + + align:start position:0% +else okay we're going to get started +then so the hardest and I think most + + align:start position:0% +then so the hardest and I think most + + + align:start position:0% +then so the hardest and I think most +important part of U the whole whole + + align:start position:0% +important part of U the whole whole + + + align:start position:0% +important part of U the whole whole +course is learning how to deal with the + + align:start position:0% +course is learning how to deal with the + + + align:start position:0% +course is learning how to deal with the +ASM totic complexity so as ASM totic + + align:start position:0% +ASM totic complexity so as ASM totic + + + align:start position:0% +ASM totic complexity so as ASM totic +complexity is this very nice tool where + + align:start position:0% +complexity is this very nice tool where + + + align:start position:0% +complexity is this very nice tool where +you have a function that looks like + + align:start position:0% +you have a function that looks like + + + align:start position:0% +you have a function that looks like +this X + + align:start position:0% +this X + + + align:start position:0% +this X +Plus what do I have here 10 + + align:start position:0% + + + + align:start position:0% + +plus + + align:start position:0% + + + + align:start position:0% + +so you have this guy which is quite long + + align:start position:0% +so you have this guy which is quite long + + + align:start position:0% +so you have this guy which is quite long +and horrible and would make your life + + align:start position:0% +and horrible and would make your life + + + align:start position:0% +and horrible and would make your life +miserable if you'd have to reason about + + align:start position:0% +miserable if you'd have to reason about + + + align:start position:0% +miserable if you'd have to reason about +it and you can say + + align:start position:0% +it and you can say + + + align:start position:0% +it and you can say +that this + + align:start position:0% +that this + + + align:start position:0% +that this +is Theta + + align:start position:0% +is Theta + + + align:start position:0% +is Theta +of n + + align:start position:0% +of n + + + align:start position:0% +of n +SED X + + align:start position:0% + + + + align:start position:0% + +sorry so everything that's here goes + + align:start position:0% +sorry so everything that's here goes + + + align:start position:0% +sorry so everything that's here goes +away and this constant Factor here goes + + align:start position:0% +away and this constant Factor here goes + + + align:start position:0% +away and this constant Factor here goes +away way and it's a nice and small + + align:start position:0% +away way and it's a nice and small + + + align:start position:0% +away way and it's a nice and small +function uh why is that the case first + + align:start position:0% +function uh why is that the case first + + + align:start position:0% +function uh why is that the case first +of all if I + + align:start position:0% +of all if I + + + align:start position:0% +of all if I +plot this function and since I don't + + align:start position:0% +plot this function and since I don't + + + align:start position:0% +plot this function and since I don't +have my projector you'll have to take my + + align:start position:0% +have my projector you'll have to take my + + + align:start position:0% +have my projector you'll have to take my +word for it I will get something that + + align:start position:0% +word for it I will get something that + + + align:start position:0% +word for it I will get something that +looks like + + align:start position:0% + + + + align:start position:0% + +this if I plot this function I will get + + align:start position:0% +this if I plot this function I will get + + + align:start position:0% +this if I plot this function I will get +something that looks like this this is a + + align:start position:0% +something that looks like this this is a + + + align:start position:0% +something that looks like this this is a +scale from0 to + + align:start position:0% +scale from0 to + + + align:start position:0% +scale from0 to +200 however if I make my + + align:start position:0% +200 however if I make my + + + align:start position:0% +200 however if I make my +scale 0 to + + align:start position:0% + + + + align:start position:0% + +20,000 let's say 200,000 to make sure + + align:start position:0% +20,000 let's say 200,000 to make sure + + + align:start position:0% +20,000 let's say 200,000 to make sure +that it's going to be + + align:start position:0% +that it's going to be + + + align:start position:0% +that it's going to be +correct X squ looks like this and this + + align:start position:0% + + + + align:start position:0% + +function looks like + + align:start position:0% +function looks like + + + align:start position:0% +function looks like +this and as you make the scale bigger + + align:start position:0% +this and as you make the scale bigger + + + align:start position:0% +this and as you make the scale bigger +and bigger you can't even see this noise + + align:start position:0% +and bigger you can't even see this noise + + + align:start position:0% +and bigger you can't even see this noise +anymore the reason is that all the noise + + align:start position:0% +anymore the reason is that all the noise + + + align:start position:0% +anymore the reason is that all the noise +is + + align:start position:0% +is + + + align:start position:0% +is +in this term in the X to the power of + + align:start position:0% +in this term in the X to the power of + + + align:start position:0% +in this term in the X to the power of +1th term + + align:start position:0% +1th term + + + align:start position:0% +1th term +and as n Pretend This is n xn same thing + + align:start position:0% +and as n Pretend This is n xn same thing + + + align:start position:0% +and as n Pretend This is n xn same thing +so as the input to the function gets + + align:start position:0% +so as the input to the function gets + + + align:start position:0% +so as the input to the function gets +bigger and bigger this grows at a much + + align:start position:0% +bigger and bigger this grows at a much + + + align:start position:0% +bigger and bigger this grows at a much +faster rate than this so if what I care + + align:start position:0% +faster rate than this so if what I care + + + align:start position:0% +faster rate than this so if what I care +about is how the function grows I can + + align:start position:0% +about is how the function grows I can + + + align:start position:0% +about is how the function grows I can +ignore + + align:start position:0% +ignore + + + align:start position:0% +ignore +anything aside from the dominant + + align:start position:0% + + + + align:start position:0% + +term do people remember this from + + align:start position:0% +term do people remember this from + + + align:start position:0% +term do people remember this from +lecture does this make + + align:start position:0% + + + + align:start position:0% + +sense okay if it doesn't that's great it + + align:start position:0% +sense okay if it doesn't that's great it + + + align:start position:0% +sense okay if it doesn't that's great it +means that I'm not wasting time covering + + align:start position:0% +means that I'm not wasting time covering + + + align:start position:0% +means that I'm not wasting time covering +it so we learned about three symbols or + + align:start position:0% +it so we learned about three symbols or + + + align:start position:0% +it so we learned about three symbols or +we will learn about three symbols when + + align:start position:0% +we will learn about three symbols when + + + align:start position:0% +we will learn about three symbols when +talking about the asmic complexity the + + align:start position:0% +talking about the asmic complexity the + + + align:start position:0% +talking about the asmic complexity the +three symbols are Theta o and + + align:start position:0% +three symbols are Theta o and + + + align:start position:0% +three symbols are Theta o and +Omega uh let's say this complicated + + align:start position:0% +Omega uh let's say this complicated + + + align:start position:0% +Omega uh let's say this complicated +function + + align:start position:0% +function + + + align:start position:0% +function +is G and this nice simple function is + + align:start position:0% + + + + align:start position:0% + +f if I say that g of X is Theta + + align:start position:0% +f if I say that g of X is Theta + + + align:start position:0% +f if I say that g of X is Theta +of F ofx that means two things it means + + align:start position:0% +of F ofx that means two things it means + + + align:start position:0% +of F ofx that means two things it means +I have a lower bound like I showed + + align:start position:0% +I have a lower bound like I showed + + + align:start position:0% +I have a lower bound like I showed +here and the lower bound looks something + + align:start position:0% +here and the lower bound looks something + + + align:start position:0% +here and the lower bound looks something +like X squ and it means that I also have + + align:start position:0% +like X squ and it means that I also have + + + align:start position:0% +like X squ and it means that I also have +a higher an upper Bound for it that also + + align:start position:0% +a higher an upper Bound for it that also + + + align:start position:0% +a higher an upper Bound for it that also +looks like X squ so the upper bound + + align:start position:0% +looks like X squ so the upper bound + + + align:start position:0% +looks like X squ so the upper bound +would be something like + + align:start position:0% +would be something like + + + align:start position:0% +would be something like +this and if I say this then I'm making a + + align:start position:0% +this and if I say this then I'm making a + + + align:start position:0% +this and if I say this then I'm making a +promise that the function stays between + + align:start position:0% +promise that the function stays between + + + align:start position:0% +promise that the function stays between +the lower bound and the upper bound and + + align:start position:0% +the lower bound and the upper bound and + + + align:start position:0% +the lower bound and the upper bound and +the bounds look sort of the same I can't + + align:start position:0% +the bounds look sort of the same I can't + + + align:start position:0% +the bounds look sort of the same I can't +really have X squ here and x squared + + align:start position:0% +really have X squ here and x squared + + + align:start position:0% +really have X squ here and x squared +here right that would be impossible so + + align:start position:0% +here right that would be impossible so + + + align:start position:0% +here right that would be impossible so +that's why I said they look the same + + align:start position:0% +that's why I said they look the same + + + align:start position:0% +that's why I said they look the same +they're not the + + align:start position:0% +they're not the + + + align:start position:0% +they're not the +same and they're not the same because + + align:start position:0% +same and they're not the same because + + + align:start position:0% +same and they're not the same because +they're allowed to differ by a constant + + align:start position:0% +they're allowed to differ by a constant + + + align:start position:0% +they're allowed to differ by a constant +Factor so if + + align:start position:0% +Factor so if + + + align:start position:0% +Factor so if +this is f and say this is f Prime F ofx + + align:start position:0% +this is f and say this is f Prime F ofx + + + align:start position:0% +this is f and say this is f Prime F ofx +might + + align:start position:0% +might + + + align:start position:0% +might +be X2 and we know for sure that this is + + align:start position:0% +be X2 and we know for sure that this is + + + align:start position:0% +be X2 and we know for sure that this is +going to be lower than this and frime of + + align:start position:0% +going to be lower than this and frime of + + + align:start position:0% +going to be lower than this and frime of +X might + + align:start position:0% + + + + align:start position:0% + +be 1.2 * x^2 and because I have a 1.1 + + align:start position:0% +be 1.2 * x^2 and because I have a 1.1 + + + align:start position:0% +be 1.2 * x^2 and because I have a 1.1 +here and I know that these get smaller + + align:start position:0% +here and I know that these get smaller + + + align:start position:0% +here and I know that these get smaller +and smaller in relation to this as the + + align:start position:0% +and smaller in relation to this as the + + + align:start position:0% +and smaller in relation to this as the +function uh as the inputs to the + + align:start position:0% +function uh as the inputs to the + + + align:start position:0% +function uh as the inputs to the +function get bigger I know that this is + + align:start position:0% +function get bigger I know that this is + + + align:start position:0% +function get bigger I know that this is +going to be the dominating factor and + + align:start position:0% +going to be the dominating factor and + + + align:start position:0% +going to be the dominating factor and +because this is bigger than this this + + align:start position:0% +because this is bigger than this this + + + align:start position:0% +because this is bigger than this this +function is going to eventually be + + align:start position:0% +function is going to eventually be + + + align:start position:0% +function is going to eventually be +larger than this function so I have a + + align:start position:0% +larger than this function so I have a + + + align:start position:0% +larger than this function so I have a +bound from above and I have a bound from + + align:start position:0% +bound from above and I have a bound from + + + align:start position:0% +bound from above and I have a bound from +below and the bounds look almost the + + align:start position:0% +below and the bounds look almost the + + + align:start position:0% +below and the bounds look almost the +same they're only different by a + + align:start position:0% +same they're only different by a + + + align:start position:0% +same they're only different by a +constant Factor this is + + align:start position:0% +constant Factor this is + + + align:start position:0% +constant Factor this is +Theta to make things spicier by the way + + align:start position:0% +Theta to make things spicier by the way + + + align:start position:0% +Theta to make things spicier by the way +Theta is really hard to pronounce as + + align:start position:0% +Theta is really hard to pronounce as + + + align:start position:0% +Theta is really hard to pronounce as +opposed to O So we usually say and write + + align:start position:0% +opposed to O So we usually say and write + + + align:start position:0% +opposed to O So we usually say and write +o instead of of theta we'll talk about + + align:start position:0% +o instead of of theta we'll talk about + + + align:start position:0% +o instead of of theta we'll talk about +what o really means in a bit but if you + + align:start position:0% +what o really means in a bit but if you + + + align:start position:0% +what o really means in a bit but if you +see o in a lot of places including our + + align:start position:0% +see o in a lot of places including our + + + align:start position:0% +see o in a lot of places including our +notes know that most of the time we + + align:start position:0% +notes know that most of the time we + + + align:start position:0% +notes know that most of the time we +actually mean Theta and sorry for that + + align:start position:0% +actually mean Theta and sorry for that + + + align:start position:0% +actually mean Theta and sorry for that +when do we know we actually + + align:start position:0% +when do we know we actually + + + align:start position:0% +when do we know we actually +mean uh you can ask us and we'll tell + + align:start position:0% +mean uh you can ask us and we'll tell + + + align:start position:0% +mean uh you can ask us and we'll tell +you fortunately it doesn't matter too + + align:start position:0% +you fortunately it doesn't matter too + + + align:start position:0% +you fortunately it doesn't matter too +much so we're trying to get an idea of + + align:start position:0% +much so we're trying to get an idea of + + + align:start position:0% +much so we're trying to get an idea of +how the functions look like in the + + align:start position:0% +how the functions look like in the + + + align:start position:0% +how the functions look like in the +bigger picture so most of the time it + + align:start position:0% +bigger picture so most of the time it + + + align:start position:0% +bigger picture so most of the time it +doesn't matter I'll give you an example + + align:start position:0% +doesn't matter I'll give you an example + + + align:start position:0% +doesn't matter I'll give you an example +though of where it matters and how it + + align:start position:0% +though of where it matters and how it + + + align:start position:0% +though of where it matters and how it +could matter + + align:start position:0% +could matter + + + align:start position:0% +could matter +so suppose I have another function that + + align:start position:0% +so suppose I have another function that + + + align:start position:0% +so suppose I have another function that +looks + + align:start position:0% +looks + + + align:start position:0% +looks +like I keep doing that that looks like + + align:start position:0% +like I keep doing that that looks like + + + align:start position:0% +like I keep doing that that looks like +this so this is kind of ugly too uh this + + align:start position:0% +this so this is kind of ugly too uh this + + + align:start position:0% +this so this is kind of ugly too uh this +function is + + align:start position:0% +function is + + + align:start position:0% +function is +um G of X say x + + align:start position:0% +um G of X say x + + + align:start position:0% +um G of X say x +* + + align:start position:0% +* + + + align:start position:0% +* +1+ s of + + align:start position:0% + + + + align:start position:0% + +x + + align:start position:0% +x + + + align:start position:0% +x +so I can't say anything about the lower + + align:start position:0% +so I can't say anything about the lower + + + align:start position:0% +so I can't say anything about the lower +bound of this this is going to hit zero + + align:start position:0% +bound of this this is going to hit zero + + + align:start position:0% +bound of this this is going to hit zero +at an infinite number of values right so + + align:start position:0% +at an infinite number of values right so + + + align:start position:0% +at an infinite number of values right so +I can't say that I can't have a nice + + align:start position:0% +I can't say that I can't have a nice + + + align:start position:0% +I can't say that I can't have a nice +lower Bound for it the lower Bound for + + align:start position:0% +lower Bound for it the lower Bound for + + + align:start position:0% +lower Bound for it the lower Bound for +it is zero but I'm pretty sure that it's + + align:start position:0% +it is zero but I'm pretty sure that it's + + + align:start position:0% +it is zero but I'm pretty sure that it's +never going to be bigger than 2x right + + align:start position:0% +never going to be bigger than 2x right + + + align:start position:0% +never going to be bigger than 2x right +and that's still worth something so + + align:start position:0% +and that's still worth something so + + + align:start position:0% +and that's still worth something so +there's this other function here that's + + align:start position:0% +there's this other function here that's + + + align:start position:0% +there's this other function here that's +supposed to be a line pretend it's a + + align:start position:0% +supposed to be a line pretend it's a + + + align:start position:0% +supposed to be a line pretend it's a +line F ofx = 2X and I know for sure that + + align:start position:0% +line F ofx = 2X and I know for sure that + + + align:start position:0% +line F ofx = 2X and I know for sure that +this this is never going to exceed these + + align:start position:0% +this this is never going to exceed these + + + align:start position:0% +this this is never going to exceed these +this and in that case where I only have + + align:start position:0% +this and in that case where I only have + + + align:start position:0% +this and in that case where I only have +one upper bound and I don't have a good + + align:start position:0% +one upper bound and I don't have a good + + + align:start position:0% +one upper bound and I don't have a good +lower bound I say that g ofx is order of + + align:start position:0% +lower bound I say that g ofx is order of + + + align:start position:0% +lower bound I say that g ofx is order of +F ofx and this is where this is what o + + align:start position:0% +F ofx and this is where this is what o + + + align:start position:0% +F ofx and this is where this is what o +really means it means I only have an + + align:start position:0% +really means it means I only have an + + + align:start position:0% +really means it means I only have an +upper bound and not a lower + + align:start position:0% +upper bound and not a lower + + + align:start position:0% +upper bound and not a lower +Bound in most of the cases when you're + + align:start position:0% +Bound in most of the cases when you're + + + align:start position:0% +Bound in most of the cases when you're +coding something you don't really care + + align:start position:0% +coding something you don't really care + + + align:start position:0% +coding something you don't really care +how how well your program can run if + + align:start position:0% +how how well your program can run if + + + align:start position:0% +how how well your program can run if +you're really lucky what you really care + + align:start position:0% +you're really lucky what you really care + + + align:start position:0% +you're really lucky what you really care +about is how does it run in the worst + + align:start position:0% +about is how does it run in the worst + + + align:start position:0% +about is how does it run in the worst +case or how does it run most of the time + + align:start position:0% +case or how does it run most of the time + + + align:start position:0% +case or how does it run most of the time +so suppose you're Google and you're + + align:start position:0% +so suppose you're Google and you're + + + align:start position:0% +so suppose you're Google and you're +writing your search engine H you have to + + align:start position:0% +writing your search engine H you have to + + + align:start position:0% +writing your search engine H you have to +return a result to the user in 200 + + align:start position:0% +return a result to the user in 200 + + + align:start position:0% +return a result to the user in 200 +milliseconds because they did a study + + align:start position:0% +milliseconds because they did a study + + + align:start position:0% +milliseconds because they did a study +that shows that if you return the result + + align:start position:0% +that shows that if you return the result + + + align:start position:0% +that shows that if you return the result +in 400 milliseconds they lose some + + align:start position:0% +in 400 milliseconds they lose some + + + align:start position:0% +in 400 milliseconds they lose some +number of users which means they lose + + align:start position:0% +number of users which means they lose + + + align:start position:0% +number of users which means they lose +some number of billions a year so to + + align:start position:0% +some number of billions a year so to + + + align:start position:0% +some number of billions a year so to +them a guarantee that their algorithms + + align:start position:0% +them a guarantee that their algorithms + + + align:start position:0% +them a guarantee that their algorithms +complete in 200 milliseconds is pretty + + align:start position:0% +complete in 200 milliseconds is pretty + + + align:start position:0% +complete in 200 milliseconds is pretty +important because it means a ton of + + align:start position:0% +important because it means a ton of + + + align:start position:0% +important because it means a ton of +money so if you have a running time that + + align:start position:0% +money so if you have a running time that + + + align:start position:0% +money so if you have a running time that +looks like this that's okay as long as + + align:start position:0% +looks like this that's okay as long as + + + align:start position:0% +looks like this that's okay as long as +this is 200 milliseconds for the number + + align:start position:0% +this is 200 milliseconds for the number + + + align:start position:0% +this is 200 milliseconds for the number +of pages that Google + + align:start position:0% +of pages that Google + + + align:start position:0% +of pages that Google +indexes does that make + + align:start position:0% + + + + align:start position:0% + +sense okay no answer means yes so if it + + align:start position:0% +sense okay no answer means yes so if it + + + align:start position:0% +sense okay no answer means yes so if it +doesn't make sense please say + + align:start position:0% + + + + align:start position:0% + +something okay I will draw another + + align:start position:0% +something okay I will draw another + + + align:start position:0% +something okay I will draw another +function again + + align:start position:0% + + + + align:start position:0% + +w + + align:start position:0% +w + + + align:start position:0% +w +what so it's one plus s of + + align:start position:0% +what so it's one plus s of + + + align:start position:0% +what so it's one plus s of +X yeah sorry my handwriting is not very + + align:start position:0% +X yeah sorry my handwriting is not very + + + align:start position:0% +X yeah sorry my handwriting is not very +good it it doesn't really matter what it + + align:start position:0% +good it it doesn't really matter what it + + + align:start position:0% +good it it doesn't really matter what it +is it just needs to it needs to be + + align:start position:0% +is it just needs to it needs to be + + + align:start position:0% +is it just needs to it needs to be +signed so that it looks wavy like this + + align:start position:0% +signed so that it looks wavy like this + + + align:start position:0% +signed so that it looks wavy like this +so that I can make something that looks + + align:start position:0% + + + + align:start position:0% + +complicated in the first example is it + + align:start position:0% +complicated in the first example is it + + + align:start position:0% +complicated in the first example is it +1.2 yes I wanted something that's higher + + align:start position:0% +1.2 yes I wanted something that's higher + + + align:start position:0% +1.2 yes I wanted something that's higher +than 1.1 so yes + + align:start position:0% + + + + align:start position:0% + +okay now that I got a break um does + + align:start position:0% +okay now that I got a break um does + + + align:start position:0% +okay now that I got a break um does +anyone else want to ask + + align:start position:0% + + + + align:start position:0% + +questions okay so I'm going to draw + + align:start position:0% +questions okay so I'm going to draw + + + align:start position:0% +questions okay so I'm going to draw +another function this one looks like + + align:start position:0% +another function this one looks like + + + align:start position:0% +another function this one looks like +this and this + + align:start position:0% + + + + align:start position:0% + +is f of x equals um 1 + sin of X I have + + align:start position:0% +is f of x equals um 1 + sin of X I have + + + align:start position:0% +is f of x equals um 1 + sin of X I have +to use the these signs to make them look + + align:start position:0% +to use the these signs to make them look + + + align:start position:0% +to use the these signs to make them look +like + + align:start position:0% +like + + + align:start position:0% +like +that times x to the power of what do I + + align:start position:0% +that times x to the power of what do I + + + align:start position:0% +that times x to the power of what do I +have there 15 plus x to the power of + + align:start position:0% + + + + align:start position:0% + +1/4 so for this function I know for sure + + align:start position:0% +1/4 so for this function I know for sure + + + align:start position:0% +1/4 so for this function I know for sure +that it is greater than x to the power + + align:start position:0% +that it is greater than x to the power + + + align:start position:0% +that it is greater than x to the power +of 1/4 right so if this is + + align:start position:0% + + + + align:start position:0% + +um I know for sure that it's greater + + align:start position:0% +um I know for sure that it's greater + + + align:start position:0% +um I know for sure that it's greater +than that also if I look at this and I + + align:start position:0% +than that also if I look at this and I + + + align:start position:0% +than that also if I look at this and I +know that sign is never bigger than one + + align:start position:0% +know that sign is never bigger than one + + + align:start position:0% +know that sign is never bigger than one +I know this whole thing is going to be + + align:start position:0% +I know this whole thing is going to be + + + align:start position:0% +I know this whole thing is going to be +at most two so if I have another + + align:start position:0% +at most two so if I have another + + + align:start position:0% +at most two so if I have another +function that + + align:start position:0% +function that + + + align:start position:0% +function that +says um frime of x equals say 3 * x ^ of + + align:start position:0% +says um frime of x equals say 3 * x ^ of + + + align:start position:0% +says um frime of x equals say 3 * x ^ of +1.5 I know that it's going to bound it + + align:start position:0% +1.5 I know that it's going to bound it + + + align:start position:0% +1.5 I know that it's going to bound it +from above so I have two + + align:start position:0% +from above so I have two + + + align:start position:0% +from above so I have two +bounds so it sort of looks like this + + align:start position:0% +bounds so it sort of looks like this + + + align:start position:0% +bounds so it sort of looks like this +case except when I I use Theta I have to + + align:start position:0% +case except when I I use Theta I have to + + + align:start position:0% +case except when I I use Theta I have to +make sure that the bounds are very + + align:start position:0% +make sure that the bounds are very + + + align:start position:0% +make sure that the bounds are very +similar they can only differ by a + + align:start position:0% +similar they can only differ by a + + + align:start position:0% +similar they can only differ by a +constant factor in this case my bounds + + align:start position:0% +constant factor in this case my bounds + + + align:start position:0% +constant factor in this case my bounds +differ by the exponent here which is + + align:start position:0% +differ by the exponent here which is + + + align:start position:0% +differ by the exponent here which is +more than a constant Factor so they're + + align:start position:0% +more than a constant Factor so they're + + + align:start position:0% +more than a constant Factor so they're +not the + + align:start position:0% +not the + + + align:start position:0% +not the +same so if I take my function which by + + align:start position:0% +same so if I take my function which by + + + align:start position:0% +same so if I take my function which by +the way is + + align:start position:0% +the way is + + + align:start position:0% +the way is +G if I want to say that um G to the x is + + align:start position:0% +G if I want to say that um G to the x is + + + align:start position:0% +G if I want to say that um G to the x is +Theta of something I can't + + align:start position:0% +Theta of something I can't + + + align:start position:0% +Theta of something I can't +because no matter what I put in here + + align:start position:0% +because no matter what I put in here + + + align:start position:0% +because no matter what I put in here +it's not going to be + + align:start position:0% +it's not going to be + + + align:start position:0% +it's not going to be +correct the lower bound is this the + + align:start position:0% +correct the lower bound is this the + + + align:start position:0% +correct the lower bound is this the +upper bound is + + align:start position:0% +upper bound is + + + align:start position:0% +upper bound is +this but what I can do is I can say that + + align:start position:0% +this but what I can do is I can say that + + + align:start position:0% +this but what I can do is I can say that +I know for sure that it is Theta of x to + + align:start position:0% +I know for sure that it is Theta of x to + + + align:start position:0% +I know for sure that it is Theta of x to +the power of 1/4 and by the way I can + + align:start position:0% +the power of 1/4 and by the way I can + + + align:start position:0% +the power of 1/4 and by the way I can +also say that it is order of x to the + + align:start position:0% +also say that it is order of x to the + + + align:start position:0% +also say that it is order of x to the +power of 1/ + + align:start position:0% + + + + align:start position:0% + +15 so if you have weird running times + + align:start position:0% +15 so if you have weird running times + + + align:start position:0% +15 so if you have weird running times +that look like this then you can only + + align:start position:0% +that look like this then you can only + + + align:start position:0% +that look like this then you can only +use um o and + + align:start position:0% +use um o and + + + align:start position:0% +use um o and +Omega and with that being said we will + + align:start position:0% +Omega and with that being said we will + + + align:start position:0% +Omega and with that being said we will +use o for pretty much the rest of the + + align:start position:0% +use o for pretty much the rest of the + + + align:start position:0% +use o for pretty much the rest of the +scores and for most of the cases we will + + align:start position:0% +scores and for most of the cases we will + + + align:start position:0% +scores and for most of the cases we will +use it to mean + + align:start position:0% + + + + align:start position:0% + +Theta oh by the way these formulas look + + align:start position:0% +Theta oh by the way these formulas look + + + align:start position:0% +Theta oh by the way these formulas look +ugly and complicated because I wanted + + align:start position:0% +ugly and complicated because I wanted + + + align:start position:0% +ugly and complicated because I wanted +the graphs to look U complicated to + + align:start position:0% +the graphs to look U complicated to + + + align:start position:0% +the graphs to look U complicated to +illustrate the idea that uh ASM totic + + align:start position:0% +illustrate the idea that uh ASM totic + + + align:start position:0% +illustrate the idea that uh ASM totic +notation makes things look simpler the + + align:start position:0% +notation makes things look simpler the + + + align:start position:0% +notation makes things look simpler the +in this course the running times that + + align:start position:0% +in this course the running times that + + + align:start position:0% +in this course the running times that +you'll be dealing with are all look like + + align:start position:0% +you'll be dealing with are all look like + + + align:start position:0% +you'll be dealing with are all look like +this they will either be order one order + + align:start position:0% +this they will either be order one order + + + align:start position:0% +this they will either be order one order +log + + align:start position:0% +log + + + align:start position:0% +log +n + + align:start position:0% +n + + + align:start position:0% +n +order n + + align:start position:0% +order n + + + align:start position:0% +order n +order and log + + align:start position:0% +order and log + + + align:start position:0% +order and log +n and Order N + + align:start position:0% +n and Order N + + + align:start position:0% +n and Order N +squared you might have a one or two + + align:start position:0% +squared you might have a one or two + + + align:start position:0% +squared you might have a one or two +cases where you get something else but + + align:start position:0% +cases where you get something else but + + + align:start position:0% +cases where you get something else but +most of the time if you have something + + align:start position:0% +most of the time if you have something + + + align:start position:0% +most of the time if you have something +else coming out of your recurrence it + + align:start position:0% +else coming out of your recurrence it + + + align:start position:0% +else coming out of your recurrence it +means you're doing it wrong + + align:start position:0% +means you're doing it wrong + + + align:start position:0% +means you're doing it wrong +so nice tip to have and you can see that + + align:start position:0% +so nice tip to have and you can see that + + + align:start position:0% +so nice tip to have and you can see that +I already started doing it I'm already + + align:start position:0% +I already started doing it I'm already + + + align:start position:0% +I already started doing it I'm already +using o instead of + + align:start position:0% +using o instead of + + + align:start position:0% +using o instead of +theta so I guess I'm getting into the + + align:start position:0% + + + + align:start position:0% + +Habit because whatever I put here is + + align:start position:0% +Habit because whatever I put here is + + + align:start position:0% +Habit because whatever I put here is +going to be wrong if I put x to the + + align:start position:0% +going to be wrong if I put x to the + + + align:start position:0% +going to be wrong if I put x to the +power of 1/5 this is wrong because I can + + align:start position:0% +power of 1/5 this is wrong because I can + + + align:start position:0% +power of 1/5 this is wrong because I can +have an upper bound that has X to the^ + + align:start position:0% +have an upper bound that has X to the^ + + + align:start position:0% +have an upper bound that has X to the^ +of 1/5 in it but I can't have a bound + + align:start position:0% +of 1/5 in it but I can't have a bound + + + align:start position:0% +of 1/5 in it but I can't have a bound +like that because this function hits x + + align:start position:0% +like that because this function hits x + + + align:start position:0% +like that because this function hits x +to the power of 1/4 in infinitely many + + align:start position:0% +to the power of 1/4 in infinitely many + + + align:start position:0% +to the power of 1/4 in infinitely many +points if I try to do x to the power of + + align:start position:0% +points if I try to do x to the power of + + + align:start position:0% +points if I try to do x to the power of +1/4 same deal lower bound yes upper + + align:start position:0% +1/4 same deal lower bound yes upper + + + align:start position:0% +1/4 same deal lower bound yes upper +bound + + align:start position:0% +bound + + + align:start position:0% +bound +no so whatever I put in here is going to + + align:start position:0% +no so whatever I put in here is going to + + + align:start position:0% +no so whatever I put in here is going to +be + + align:start position:0% +be + + + align:start position:0% +be +wrong thank you good + + align:start position:0% +wrong thank you good + + + align:start position:0% +wrong thank you good +question yes or4 uh 1.4 they're 1.4 and + + align:start position:0% +question yes or4 uh 1.4 they're 1.4 and + + + align:start position:0% +question yes or4 uh 1.4 they're 1.4 and +1.5 okay I thought you were saying one4 + + align:start position:0% +1.5 okay I thought you were saying one4 + + + align:start position:0% +1.5 okay I thought you were saying one4 +and oh sorry 14 1.4 1.4 + + align:start position:0% + + + + align:start position:0% + +1.5 okay are we good so + + align:start position:0% + + + + align:start position:0% + +far okay let's go through a couple of + + align:start position:0% +far okay let's go through a couple of + + + align:start position:0% +far okay let's go through a couple of +exercises so I'll give you a few + + align:start position:0% +exercises so I'll give you a few + + + align:start position:0% +exercises so I'll give you a few +functions yes theega is it's a lower + + align:start position:0% +functions yes theega is it's a lower + + + align:start position:0% +functions yes theega is it's a lower +bound already without multiplying by any + + align:start position:0% +bound already without multiplying by any + + + align:start position:0% +bound already without multiplying by any +constant or something is that what it is + + align:start position:0% +constant or something is that what it is + + + align:start position:0% +constant or something is that what it is +so for all of these what you put + + align:start position:0% +so for all of these what you put + + + align:start position:0% +so for all of these what you put +here is the simple is the simple form so + + align:start position:0% +here is the simple is the simple form so + + + align:start position:0% +here is the simple is the simple form so +your lower bound can be this function + + align:start position:0% +your lower bound can be this function + + + align:start position:0% +your lower bound can be this function +multiplied by any constant Factor Omega + + align:start position:0% +multiplied by any constant Factor Omega + + + align:start position:0% +multiplied by any constant Factor Omega +me lower um Omega means lower bound o + + align:start position:0% +me lower um Omega means lower bound o + + + align:start position:0% +me lower um Omega means lower bound o +means upper bound Theta means + + align:start position:0% + + + + align:start position:0% + +both okay + + align:start position:0% + + + + align:start position:0% + +any other things to clear up before I + + align:start position:0% +any other things to clear up before I + + + align:start position:0% +any other things to clear up before I +ask + + align:start position:0% +ask + + + align:start position:0% +ask +questions so it's your turn before it's + + align:start position:0% +questions so it's your turn before it's + + + align:start position:0% +questions so it's your turn before it's +my + + align:start position:0% + + + + align:start position:0% + +turn all right I'm going to go over a + + align:start position:0% +turn all right I'm going to go over a + + + align:start position:0% +turn all right I'm going to go over a +few functions and I want you guys to + + align:start position:0% +few functions and I want you guys to + + + align:start position:0% +few functions and I want you guys to +tell me what um to help me write them in + + align:start position:0% +tell me what um to help me write them in + + + align:start position:0% +tell me what um to help me write them in +asmic + + align:start position:0% +asmic + + + align:start position:0% +asmic +notation so I will + + align:start position:0% +notation so I will + + + align:start position:0% +notation so I will +have F of N and I want to know its sta + + align:start position:0% +have F of N and I want to know its sta + + + align:start position:0% +have F of N and I want to know its sta +of + + align:start position:0% +of + + + align:start position:0% +of +what so let's start with with f of Nal + + align:start position:0% +what so let's start with with f of Nal + + + align:start position:0% +what so let's start with with f of Nal +10 to the + + align:start position:0% +10 to the + + + align:start position:0% +10 to the +80 does anyone know why 10 to the + + align:start position:0% + + + + align:start position:0% + + + align:start position:0% + + + + align:start position:0% + +yes okay that's the correct answer + + align:start position:0% +yes okay that's the correct answer + + + align:start position:0% +yes okay that's the correct answer +you're going ahead though I was + + align:start position:0% +you're going ahead though I was + + + align:start position:0% +you're going ahead though I was +wondering if I was wondering if you know + + align:start position:0% +wondering if I was wondering if you know + + + align:start position:0% +wondering if I was wondering if you know +why why why did I choose this does + + align:start position:0% +why why why did I choose this does + + + align:start position:0% +why why why did I choose this does +anyone know why I chose this + + align:start position:0% +anyone know why I chose this + + + align:start position:0% +anyone know why I chose this +yes uh I think that's + + align:start position:0% +yes uh I think that's + + + align:start position:0% +yes uh I think that's +100 you're getting close though it's + + align:start position:0% +100 you're getting close though it's + + + align:start position:0% +100 you're getting close though it's +something think it's a really big number + + align:start position:0% +something think it's a really big number + + + align:start position:0% +something think it's a really big number +it's a really big number all right so + + align:start position:0% +it's a really big number all right so + + + align:start position:0% +it's a really big number all right so +it's a really big number that's the + + align:start position:0% +it's a really big number that's the + + + align:start position:0% +it's a really big number that's the +estimated number of atoms in the + + align:start position:0% +estimated number of atoms in the + + + align:start position:0% +estimated number of atoms in the +universe so realistically any quantity + + align:start position:0% +universe so realistically any quantity + + + align:start position:0% +universe so realistically any quantity +that you deal with that will represent + + align:start position:0% +that you deal with that will represent + + + align:start position:0% +that you deal with that will represent +the real world is not going to be bigger + + align:start position:0% +the real world is not going to be bigger + + + align:start position:0% +the real world is not going to be bigger +than + + align:start position:0% +than + + + align:start position:0% +than +this so if you want to get all + + align:start position:0% +this so if you want to get all + + + align:start position:0% +this so if you want to get all +philosophical you can say that for any + + align:start position:0% +philosophical you can say that for any + + + align:start position:0% +philosophical you can say that for any +algorithm that you write and any + + align:start position:0% +algorithm that you write and any + + + align:start position:0% +algorithm that you write and any +realistic input the running time will be + + align:start position:0% +realistic input the running time will be + + + align:start position:0% +realistic input the running time will be +Theta of one but if you do this we're + + align:start position:0% +Theta of one but if you do this we're + + + align:start position:0% +Theta of one but if you do this we're +not going to be happy with you on exams + + align:start position:0% +not going to be happy with you on exams + + + align:start position:0% +not going to be happy with you on exams +so let's choose another + + align:start position:0% +so let's choose another + + + align:start position:0% +so let's choose another +one 20 n to the power of + + align:start position:0% + + + + align:start position:0% + +7th what's this an ASM totic notation + + align:start position:0% +7th what's this an ASM totic notation + + + align:start position:0% +7th what's this an ASM totic notation +and + + align:start position:0% + + + + align:start position:0% + +why yes order + + align:start position:0% +why yes order + + + align:start position:0% +why yes order +of + + align:start position:0% +of + + + align:start position:0% +of +okay that's same thing and to the seven + + align:start position:0% +okay that's same thing and to the seven + + + align:start position:0% +okay that's same thing and to the seven +thank you why is that because if you + + align:start position:0% +thank you why is that because if you + + + align:start position:0% +thank you why is that because if you +distribute the exponent s 20 to S just a + + align:start position:0% +distribute the exponent s 20 to S just a + + + align:start position:0% +distribute the exponent s 20 to S just a +Conant excellent 20 to the 7 time n to + + align:start position:0% +Conant excellent 20 to the 7 time n to + + + align:start position:0% +Conant excellent 20 to the 7 time n to +the 7 this is a constant so it goes + + align:start position:0% + + + + align:start position:0% + +away okay and before I do another one I + + align:start position:0% +away okay and before I do another one I + + + align:start position:0% +away okay and before I do another one I +want to give you guys some help and + + align:start position:0% +want to give you guys some help and + + + align:start position:0% +want to give you guys some help and +remind you about logs how many people + + align:start position:0% +remind you about logs how many people + + + align:start position:0% +remind you about logs how many people +remember the laws of working with logs + + align:start position:0% +remember the laws of working with logs + + + align:start position:0% +remember the laws of working with logs +from algebra or some math + + align:start position:0% +from algebra or some math + + + align:start position:0% +from algebra or some math +class all right you guys will be helping + + align:start position:0% +class all right you guys will be helping + + + align:start position:0% +class all right you guys will be helping +me write them for everyone else so if I + + align:start position:0% +me write them for everyone else so if I + + + align:start position:0% +me write them for everyone else so if I +have log of n to the 100 and I want to + + align:start position:0% +have log of n to the 100 and I want to + + + align:start position:0% +have log of n to the 100 and I want to +get the Theta notation for it what is it + + align:start position:0% +get the Theta notation for it what is it + + + align:start position:0% +get the Theta notation for it what is it +and + + align:start position:0% + + + + align:start position:0% + +why okay + + align:start position:0% + + + + align:start position:0% + +excellent why is that the + + align:start position:0% + + + + align:start position:0% + +case okay so when I have an exponent + + align:start position:0% +case okay so when I have an exponent + + + align:start position:0% +case okay so when I have an exponent +here I can pull it out in front of the + + align:start position:0% +here I can pull it out in front of the + + + align:start position:0% +here I can pull it out in front of the +log as a constant Factor so this is the + + align:start position:0% +log as a constant Factor so this is the + + + align:start position:0% +log as a constant Factor so this is the +same thing as + + align:start position:0% +same thing as + + + align:start position:0% +same thing as +100 log + + align:start position:0% +100 log + + + align:start position:0% +100 log +n okay now if I have a logarithm uh to + + align:start position:0% +n okay now if I have a logarithm uh to + + + align:start position:0% +n okay now if I have a logarithm uh to +the base uh using base five of + + align:start position:0% +the base uh using base five of + + + align:start position:0% +the base uh using base five of +n how about + + align:start position:0% + + + + align:start position:0% + +this l n okay so this is can you say + + align:start position:0% +this l n okay so this is can you say + + + align:start position:0% +this l n okay so this is can you say +that again log okay so this is theeta of + + align:start position:0% +that again log okay so this is theeta of + + + align:start position:0% +that again log okay so this is theeta of +log n because it + + align:start position:0% +log n because it + + + align:start position:0% +log n because it +is + + align:start position:0% +is + + + align:start position:0% +is +excellent log n + + align:start position:0% +excellent log n + + + align:start position:0% +excellent log n +over log + + align:start position:0% +over log + + + align:start position:0% +over log +five so exponents inside the logs turn + + align:start position:0% +five so exponents inside the logs turn + + + align:start position:0% +five so exponents inside the logs turn +into constant factors bases turn into + + align:start position:0% +into constant factors bases turn into + + + align:start position:0% +into constant factors bases turn into +constant + + align:start position:0% +constant + + + align:start position:0% +constant +factors so if you have a an ugly + + align:start position:0% +factors so if you have a an ugly + + + align:start position:0% +factors so if you have a an ugly +expression inside the logarithm you can + + align:start position:0% +expression inside the logarithm you can + + + align:start position:0% +expression inside the logarithm you can +most of the time simplify it to + + align:start position:0% +most of the time simplify it to + + + align:start position:0% +most of the time simplify it to +something really nice and this + + align:start position:0% +something really nice and this + + + align:start position:0% +something really nice and this +contributes to the fact that um these + + align:start position:0% +contributes to the fact that um these + + + align:start position:0% +contributes to the fact that um these +are the only functions that you will see + + align:start position:0% +are the only functions that you will see + + + align:start position:0% +are the only functions that you will see +when the answer is cleaned up in asmic + + align:start position:0% + + + + align:start position:0% + +notation okay yes so when you're writing + + align:start position:0% +notation okay yes so when you're writing + + + align:start position:0% +notation okay yes so when you're writing +log are you assuming certain base then + + align:start position:0% +log are you assuming certain base then + + + align:start position:0% +log are you assuming certain base then +yes there is a certain base for logs uh + + align:start position:0% +yes there is a certain base for logs uh + + + align:start position:0% +yes there is a certain base for logs uh +we're all computer scientists right so + + align:start position:0% +we're all computer scientists right so + + + align:start position:0% +we're all computer scientists right so +what's the natural base for our + + align:start position:0% + + + + align:start position:0% + +logarithms okay sweet uh math + + align:start position:0% +logarithms okay sweet uh math + + + align:start position:0% +logarithms okay sweet uh math +major no yeah I natural Bas okay yeah + + align:start position:0% +major no yeah I natural Bas okay yeah + + + align:start position:0% +major no yeah I natural Bas okay yeah +it's a math joke so for everyone else a + + align:start position:0% +it's a math joke so for everyone else a + + + align:start position:0% +it's a math joke so for everyone else a +natural logorithm is in Bas e for us CS + + align:start position:0% +natural logorithm is in Bas e for us CS + + + align:start position:0% +natural logorithm is in Bas e for us CS +people a natural base is two because + + align:start position:0% +people a natural base is two because + + + align:start position:0% +people a natural base is two because +that's how many values you have for a + + align:start position:0% +that's how many values you have for a + + + align:start position:0% +that's how many values you have for a +bit + + align:start position:0% +bit + + + align:start position:0% +bit +so log + + align:start position:0% + + + + align:start position:0% + +means log n is log base 2 of + + align:start position:0% +means log n is log base 2 of + + + align:start position:0% +means log n is log base 2 of +n uh the good news is that most of the + + align:start position:0% +n uh the good news is that most of the + + + align:start position:0% +n uh the good news is that most of the +time we're working with asmic notation + + align:start position:0% +time we're working with asmic notation + + + align:start position:0% +time we're working with asmic notation +so it doesn't really matter we can + + align:start position:0% +so it doesn't really matter we can + + + align:start position:0% +so it doesn't really matter we can +communicate with our math friends and we + + align:start position:0% +communicate with our math friends and we + + + align:start position:0% +communicate with our math friends and we +don't have to talk about + + align:start position:0% +don't have to talk about + + + align:start position:0% +don't have to talk about +this okay I need to get another + + align:start position:0% +this okay I need to get another + + + align:start position:0% +this okay I need to get another +complicated example and my memory fails + + align:start position:0% + + + + align:start position:0% + +me + + align:start position:0% + + + + align:start position:0% + +okay so log see I'm using Ln to mean the + + align:start position:0% +okay so log see I'm using Ln to mean the + + + align:start position:0% +okay so log see I'm using Ln to mean the +math natural logarithm + + align:start position:0% +math natural logarithm + + + align:start position:0% +math natural logarithm +so we still have that somewhere in + + align:start position:0% +so we still have that somewhere in + + + align:start position:0% +so we still have that somewhere in +here + + align:start position:0% +here + + + align:start position:0% +here +of log n to the base + + align:start position:0% +of log n to the base + + + align:start position:0% +of log n to the base +100 they made me add all these + + align:start position:0% +100 they made me add all these + + + align:start position:0% +100 they made me add all these +parentheses in the last section to be + + align:start position:0% +parentheses in the last section to be + + + align:start position:0% +parentheses in the last section to be +clear so I'm adding them now from the + + align:start position:0% +clear so I'm adding them now from the + + + align:start position:0% +clear so I'm adding them now from the +start who wants to help me clean this + + align:start position:0% + + + + align:start position:0% + +up yes log l all right wow one + + align:start position:0% +up yes log l all right wow one + + + align:start position:0% +up yes log l all right wow one +step log log + + align:start position:0% + + + + align:start position:0% + +n okay uh can you tell me why very + + align:start position:0% +n okay uh can you tell me why very + + + align:start position:0% +n okay uh can you tell me why very +quickly so we can simplify out the base + + align:start position:0% +quickly so we can simplify out the base + + + align:start position:0% +quickly so we can simplify out the base +and the exponent in there okay then base + + align:start position:0% +and the exponent in there okay then base + + + align:start position:0% +and the exponent in there okay then base +goes out exponent goes out log log of + + align:start position:0% +goes out exponent goes out log log of + + + align:start position:0% +goes out exponent goes out log log of +something is another class complexity + + align:start position:0% +something is another class complexity + + + align:start position:0% +something is another class complexity +that's not exactly up there but + + align:start position:0% +that's not exactly up there but + + + align:start position:0% +that's not exactly up there but +occasionally + + align:start position:0% +occasionally + + + align:start position:0% +occasionally +yep uh what does a theory students say + + align:start position:0% +yep uh what does a theory students say + + + align:start position:0% +yep uh what does a theory students say +when they're + + align:start position:0% + + + + align:start position:0% + +drowning log log log log some of you are + + align:start position:0% +drowning log log log log some of you are + + + align:start position:0% +drowning log log log log some of you are +laughing already you guys know this okay + + align:start position:0% +laughing already you guys know this okay + + + align:start position:0% +laughing already you guys know this okay +what if I want to make this a little bit + + align:start position:0% +what if I want to make this a little bit + + + align:start position:0% +what if I want to make this a little bit +harder and + + align:start position:0% +harder and + + + align:start position:0% +harder and +um I + + align:start position:0% +um I + + + align:start position:0% +um I +say + + align:start position:0% +say + + + align:start position:0% +say +log l five + + align:start position:0% +log l five + + + align:start position:0% +log l five +of log n to the + + align:start position:0% +of log n to the + + + align:start position:0% +of log n to the +100 you have to do a bit more work now + + align:start position:0% +100 you have to do a bit more work now + + + align:start position:0% +100 you have to do a bit more work now +you can't just use the tricks on the + + align:start position:0% + + + + align:start position:0% + +right anyone + + align:start position:0% +right anyone + + + align:start position:0% +right anyone +else + + align:start position:0% +else + + + align:start position:0% +else +yes okay it is still log log n but for a + + align:start position:0% +yes okay it is still log log n but for a + + + align:start position:0% +yes okay it is still log log n but for a +different reason + + align:start position:0% + + + + align:start position:0% + +right almost okay maybe not so the base + + align:start position:0% +right almost okay maybe not so the base + + + align:start position:0% +right almost okay maybe not so the base +still goes out just like + + align:start position:0% +still goes out just like + + + align:start position:0% +still goes out just like +before but this guy now goes out here so + + align:start position:0% +before but this guy now goes out here so + + + align:start position:0% +before but this guy now goes out here so +I will have this be sort of + + align:start position:0% +I will have this be sort of + + + align:start position:0% +I will have this be sort of +like I notice that I'm not saying equal + + align:start position:0% +like I notice that I'm not saying equal + + + align:start position:0% +like I notice that I'm not saying equal +I'm saying like because I got rid of the + + align:start position:0% +I'm saying like because I got rid of the + + + align:start position:0% +I'm saying like because I got rid of the +base so it's like 100 + + align:start position:0% +base so it's like 100 + + + align:start position:0% +base so it's like 100 +time log n which + + align:start position:0% +time log n which + + + align:start position:0% +time log n which +is + + align:start position:0% +is + + + align:start position:0% +is +log 100 + + align:start position:0% +log 100 + + + align:start position:0% +log 100 +plus log log + + align:start position:0% + + + + align:start position:0% + +n and this is a constant Factor this + + align:start position:0% +n and this is a constant Factor this + + + align:start position:0% +n and this is a constant Factor this +grows as n grows so this is going to + + align:start position:0% +grows as n grows so this is going to + + + align:start position:0% +grows as n grows so this is going to +become incredibly small as n becomes + + align:start position:0% +become incredibly small as n becomes + + + align:start position:0% +become incredibly small as n becomes +larger and larger so I can get rid of + + align:start position:0% + + + + align:start position:0% + +it + + align:start position:0% +it + + + align:start position:0% +it +okay + + align:start position:0% +okay + + + align:start position:0% +okay +okay uh one more and this one's going to + + align:start position:0% +okay uh one more and this one's going to + + + align:start position:0% +okay uh one more and this one's going to +be less + + align:start position:0% +be less + + + align:start position:0% +be less +boring of 100 going from the last step + + align:start position:0% +boring of 100 going from the last step + + + align:start position:0% +boring of 100 going from the last step +how are you able to pop it + + align:start position:0% +how are you able to pop it + + + align:start position:0% +how are you able to pop it +out uh if my memory remember if my + + align:start position:0% +out uh if my memory remember if my + + + align:start position:0% +out uh if my memory remember if my +memory works I think log of a is log a + + align:start position:0% +memory works I think log of a is log a + + + align:start position:0% +memory works I think log of a is log a +plus log B am I right guys + + align:start position:0% + + + + align:start position:0% + +sweet + + align:start position:0% +sweet + + + align:start position:0% +sweet +good question I'm I wasn't sure but now + + align:start position:0% +good question I'm I wasn't sure but now + + + align:start position:0% +good question I'm I wasn't sure but now +that you asked everyone else help me + + align:start position:0% +that you asked everyone else help me + + + align:start position:0% +that you asked everyone else help me +make sure it's + + align:start position:0% + + + + align:start position:0% + +right okay I'm erasing so much because + + align:start position:0% +right okay I'm erasing so much because + + + align:start position:0% +right okay I'm erasing so much because +we're going to need more room for this + + align:start position:0% +we're going to need more room for this + + + align:start position:0% +we're going to need more room for this +so I have a log again but this time what + + align:start position:0% +so I have a log again but this time what + + + align:start position:0% +so I have a log again but this time what +I have inside the log is n choose n + + align:start position:0% +I have inside the log is n choose n + + + align:start position:0% +I have inside the log is n choose n +/2 does any Brave Sol wants to come up + + align:start position:0% +/2 does any Brave Sol wants to come up + + + align:start position:0% +/2 does any Brave Sol wants to come up +here and Sol this for + + align:start position:0% + + + + align:start position:0% + +me + + align:start position:0% + + + + align:start position:0% + +no you guys are going to make me ride + + align:start position:0% +no you guys are going to make me ride + + + align:start position:0% +no you guys are going to make me ride +for the entire + + align:start position:0% + + + + align:start position:0% + +hour I off for + + align:start position:0% + + + + align:start position:0% + +help so this is is n factorial + + align:start position:0% + + + + align:start position:0% + +yep n factorial Over N / 2 factorial + + align:start position:0% +yep n factorial Over N / 2 factorial + + + align:start position:0% +yep n factorial Over N / 2 factorial +times then / 2 + + align:start position:0% +times then / 2 + + + align:start position:0% +times then / 2 +factorial + + align:start position:0% + + + + align:start position:0% + +close and I'll give out another hint + + align:start position:0% +close and I'll give out another hint + + + align:start position:0% +close and I'll give out another hint +which is that n factorial can be + + align:start position:0% +which is that n factorial can be + + + align:start position:0% +which is that n factorial can be +approximated as Square < TK of 2 pi n + + align:start position:0% +approximated as Square < TK of 2 pi n + + + align:start position:0% +approximated as Square < TK of 2 pi n +multiplied by n / e / n uh to the power + + align:start position:0% +multiplied by n / e / n uh to the power + + + align:start position:0% +multiplied by n / e / n uh to the power +of n but I think this will make you guys + + align:start position:0% +of n but I think this will make you guys + + + align:start position:0% +of n but I think this will make you guys +not want to come up and Sol this + + align:start position:0% + + + + align:start position:0% + +yes I + + align:start position:0% +yes I + + + align:start position:0% +yes I +was is that it is that not it did I get + + align:start position:0% +was is that it is that not it did I get + + + align:start position:0% +was is that it is that not it did I get +it wrong okay + + align:start position:0% + + + + align:start position:0% + +I I think that's an ASM totic that's + + align:start position:0% +I I think that's an ASM totic that's + + + align:start position:0% +I I think that's an ASM totic that's +that's what we'll I think we'll get to + + align:start position:0% +that's what we'll I think we'll get to + + + align:start position:0% +that's what we'll I think we'll get to +that but factorials grow + + align:start position:0% +that but factorials grow + + + align:start position:0% +that but factorials grow +exponentially so it should be something + + align:start position:0% +exponentially so it should be something + + + align:start position:0% +exponentially so it should be something +like + + align:start position:0% +like + + + align:start position:0% +like +this okay so we have that nice + + align:start position:0% +this okay so we have that nice + + + align:start position:0% +this okay so we have that nice +approximation does anyone want to work + + align:start position:0% +approximation does anyone want to work + + + align:start position:0% +approximation does anyone want to work +it out or will I have to do + + align:start position:0% + + + + align:start position:0% + +it keep that in mind when I'm grading + + align:start position:0% +it keep that in mind when I'm grading + + + align:start position:0% +it keep that in mind when I'm grading +your + + align:start position:0% +your + + + align:start position:0% +your +homework okay so it's log of square < TK + + align:start position:0% +homework okay so it's log of square < TK + + + align:start position:0% +homework okay so it's log of square < TK +2 pi n + + align:start position:0% +2 pi n + + + align:start position:0% +2 pi n +MTI power + + align:start position:0% +MTI power + + + align:start position:0% +MTI power +n I'm going to put these two together + + align:start position:0% +n I'm going to put these two together + + + align:start position:0% +n I'm going to put these two together +so 2 + + align:start position:0% +so 2 + + + align:start position:0% +so 2 +pi and + + align:start position:0% +pi and + + + align:start position:0% +pi and +over there's an N / two there right so + + align:start position:0% +over there's an N / two there right so + + + align:start position:0% +over there's an N / two there right so +it's n / 2 + + align:start position:0% + + + + align:start position:0% + +etimes N / + + align:start position:0% +etimes N / + + + align:start position:0% +etimes N / +2 the Power of + + align:start position:0% + + + + align:start position:0% + +Two okay I can get rid of this guy + + align:start position:0% +Two okay I can get rid of this guy + + + align:start position:0% +Two okay I can get rid of this guy +because it's a + + align:start position:0% +because it's a + + + align:start position:0% +because it's a +constant I can get no I can't get rid of + + align:start position:0% +constant I can get no I can't get rid of + + + align:start position:0% +constant I can get no I can't get rid of +this guy yet + + align:start position:0% + + + + align:start position:0% + +thein under the + + align:start position:0% +thein under the + + + align:start position:0% +thein under the +rad yep 2 pi and over two so this + + align:start position:0% +rad yep 2 pi and over two so this + + + align:start position:0% +rad yep 2 pi and over two so this +simplifies okay thank + + align:start position:0% +simplifies okay thank + + + align:start position:0% +simplifies okay thank +you sare the bottom and get + + align:start position:0% + + + + align:start position:0% + +theare + + align:start position:0% + + + + align:start position:0% + +andc expon okay can help me thanks so + + align:start position:0% +andc expon okay can help me thanks so + + + align:start position:0% +andc expon okay can help me thanks so +much + + align:start position:0% + + + + align:start position:0% + +okay so we can distribute this exponent + + align:start position:0% +okay so we can distribute this exponent + + + align:start position:0% +okay so we can distribute this exponent +here to cancel this and then we get a + + align:start position:0% +here to cancel this and then we get a + + + align:start position:0% +here to cancel this and then we get a +square root of + + align:start position:0% + + + + align:start position:0% + +Pi sorry my hand I think it's better + + align:start position:0% +Pi sorry my hand I think it's better + + + align:start position:0% +Pi sorry my hand I think it's better +than mine by quite a + + align:start position:0% +than mine by quite a + + + align:start position:0% +than mine by quite a +bit square root + + align:start position:0% + + + + align:start position:0% + +of n oops and this is squ squ so that + + align:start position:0% + + + + align:start position:0% + +cancels yeah that's probably good so um + + align:start position:0% +cancels yeah that's probably good so um + + + align:start position:0% +cancels yeah that's probably good so um +since this is a n e to the n and n to e + + align:start position:0% +since this is a n e to the n and n to e + + + align:start position:0% +since this is a n e to the n and n to e +to the end well since they're to the end + + align:start position:0% +to the end well since they're to the end + + + align:start position:0% +to the end well since they're to the end +um both the N we can uh keep them as a + + align:start position:0% +um both the N we can uh keep them as a + + + align:start position:0% +um both the N we can uh keep them as a +single exponent cancel stuff so we just + + align:start position:0% +single exponent cancel stuff so we just + + + align:start position:0% +single exponent cancel stuff so we just +get + + align:start position:0% +get + + + align:start position:0% +get +uh square root of Pi n the * 2 the N + + align:start position:0% +uh square root of Pi n the * 2 the N + + + align:start position:0% +uh square root of Pi n the * 2 the N +over Pi + + align:start position:0% + + + + align:start position:0% + +n can do some more cancelling and just + + align:start position:0% +n can do some more cancelling and just + + + align:start position:0% +n can do some more cancelling and just +get uh to the n + + align:start position:0% + + + + align:start position:0% + +going to simplify this to the end over + + align:start position:0% +going to simplify this to the end over + + + align:start position:0% +going to simplify this to the end over +the square root + + align:start position:0% +the square root + + + align:start position:0% +the square root +of and uh we can take out the pi because + + align:start position:0% +of and uh we can take out the pi because + + + align:start position:0% +of and uh we can take out the pi because +it's an natural logorithm and it's a + + align:start position:0% +it's an natural logorithm and it's a + + + align:start position:0% +it's an natural logorithm and it's a +constant factor and this + + align:start position:0% +constant factor and this + + + align:start position:0% +constant factor and this +is log + + align:start position:0% + + + + align:start position:0% + +of and + + align:start position:0% + + + + align:start position:0% + +then since it's a log of it's just a log + + align:start position:0% +then since it's a log of it's just a log + + + align:start position:0% +then since it's a log of it's just a log +of 2 the N so it's + + align:start position:0% + + + + align:start position:0% + +uh um say since it's a log you can take + + align:start position:0% +uh um say since it's a log you can take + + + align:start position:0% +uh um say since it's a log you can take +out you can turn into log of 2 the N + + align:start position:0% +out you can turn into log of 2 the N + + + align:start position:0% +out you can turn into log of 2 the N +minus log of squ n uh log of two to the + + align:start position:0% +minus log of squ n uh log of two to the + + + align:start position:0% +minus log of squ n uh log of two to the +N is a much greater complexity than + + align:start position:0% +N is a much greater complexity than + + + align:start position:0% +N is a much greater complexity than +square of n so we can sweet thank + + align:start position:0% +square of n so we can sweet thank + + + align:start position:0% +square of n so we can sweet thank +you so see complicated formula even more + + align:start position:0% +you so see complicated formula even more + + + align:start position:0% +you so see complicated formula even more +complicated formula came out to be one + + align:start position:0% +complicated formula came out to be one + + + align:start position:0% +complicated formula came out to be one +of the numbers that I promised it would + + align:start position:0% +of the numbers that I promised it would + + + align:start position:0% +of the numbers that I promised it would +come out to thanks for the help so you + + align:start position:0% +come out to thanks for the help so you + + + align:start position:0% +come out to thanks for the help so you +can get rid of the pi as soon as you + + align:start position:0% +can get rid of the pi as soon as you + + + align:start position:0% +can get rid of the pi as soon as you +want to and this is the last step I I + + align:start position:0% +want to and this is the last step I I + + + align:start position:0% +want to and this is the last step I I +just want to say it again to make sure + + align:start position:0% +just want to say it again to make sure + + + align:start position:0% +just want to say it again to make sure +everyone heard it so once you get here + + align:start position:0% +everyone heard it so once you get here + + + align:start position:0% +everyone heard it so once you get here +you get this order n + + align:start position:0% +you get this order n + + + align:start position:0% +you get this order n +minus log of square Ro TK of n which + + align:start position:0% +minus log of square Ro TK of n which + + + align:start position:0% +minus log of square Ro TK of n which +is + + align:start position:0% + + + + align:start position:0% + +um this is um + + align:start position:0% + + + + align:start position:0% + +this is order n minus one + + align:start position:0% +this is order n minus one + + + align:start position:0% +this is order n minus one +half log n and the log n is much smaller + + align:start position:0% +half log n and the log n is much smaller + + + align:start position:0% +half log n and the log n is much smaller +than n so this goes away completely and + + align:start position:0% +than n so this goes away completely and + + + align:start position:0% +than n so this goes away completely and +you get this as your final + + align:start position:0% + + + + align:start position:0% + +answer okay that's this make + + align:start position:0% + + + + align:start position:0% + +sense any questions + + align:start position:0% +sense any questions + + + align:start position:0% +sense any questions +anyone how many people are still paying + + align:start position:0% +anyone how many people are still paying + + + align:start position:0% +anyone how many people are still paying +attention + + align:start position:0% +attention + + + align:start position:0% +attention +honestly wow + + align:start position:0% +honestly wow + + + align:start position:0% +honestly wow +nice you should come to all my + + align:start position:0% + + + + align:start position:0% + +sections + + align:start position:0% + + + + align:start position:0% + +okay let's talk about something we + + align:start position:0% +okay let's talk about something we + + + align:start position:0% +okay let's talk about something we +covered in class let's talk about Peak + + align:start position:0% +covered in class let's talk about Peak + + + align:start position:0% +covered in class let's talk about Peak +finding and we'll start with ond Peak + + align:start position:0% +finding and we'll start with ond Peak + + + align:start position:0% +finding and we'll start with ond Peak +finding and then we'll go to 2D pick + + align:start position:0% +finding and then we'll go to 2D pick + + + align:start position:0% +finding and then we'll go to 2D pick +finding so does anyone remember the + + align:start position:0% +finding so does anyone remember the + + + align:start position:0% +finding so does anyone remember the +pseudo code for the faster 1D pick + + align:start position:0% +pseudo code for the faster 1D pick + + + align:start position:0% +pseudo code for the faster 1D pick +finding by any + + align:start position:0% + + + + align:start position:0% + +chance + + align:start position:0% +chance + + + align:start position:0% +chance +ond Peak + + align:start position:0% + + + + align:start position:0% + +finding I think everyone said they went + + align:start position:0% +finding I think everyone said they went + + + align:start position:0% +finding I think everyone said they went +to lecture so I don't have to explain + + align:start position:0% +to lecture so I don't have to explain + + + align:start position:0% +to lecture so I don't have to explain +what Peak finding is right + + align:start position:0% + + + + align:start position:0% + +okay let's go for it so suppose I have a + + align:start position:0% +okay let's go for it so suppose I have a + + + align:start position:0% +okay let's go for it so suppose I have a +few numbers uh three let me write this + + align:start position:0% +few numbers uh three let me write this + + + align:start position:0% +few numbers uh three let me write this +three four five six + + align:start position:0% +three four five six + + + align:start position:0% +three four five six +7 6 + + align:start position:0% + + + + align:start position:0% + +54 so the pick finding problem says + + align:start position:0% +54 so the pick finding problem says + + + align:start position:0% +54 so the pick finding problem says +there's an array of numbers and I want + + align:start position:0% +there's an array of numbers and I want + + + align:start position:0% +there's an array of numbers and I want +to find the local Peak and the local + + align:start position:0% +to find the local Peak and the local + + + align:start position:0% +to find the local Peak and the local +Peak is a number that surrounded by + + align:start position:0% +Peak is a number that surrounded by + + + align:start position:0% +Peak is a number that surrounded by +numbers that are smaller or equal to it + + align:start position:0% +numbers that are smaller or equal to it + + + align:start position:0% +numbers that are smaller or equal to it +so there shouldn't be any larger numbers + + align:start position:0% +so there shouldn't be any larger numbers + + + align:start position:0% +so there shouldn't be any larger numbers +than it and I want to find a peak as + + align:start position:0% +than it and I want to find a peak as + + + align:start position:0% +than it and I want to find a peak as +quickly as I + + align:start position:0% +quickly as I + + + align:start position:0% +quickly as I +can so what's the faster algorithm that + + align:start position:0% +can so what's the faster algorithm that + + + align:start position:0% +can so what's the faster algorithm that +we talked about in + + align:start position:0% + + + + align:start position:0% + +lecture yes okay you didn't answer right + + align:start position:0% +lecture yes okay you didn't answer right + + + align:start position:0% +lecture yes okay you didn't answer right +as much at least + + align:start position:0% +as much at least + + + align:start position:0% +as much at least +so yeah binary search okay it's exactly + + align:start position:0% +so yeah binary search okay it's exactly + + + align:start position:0% +so yeah binary search okay it's exactly +like binary search yep uh do help me + + align:start position:0% +like binary search yep uh do help me + + + align:start position:0% +like binary search yep uh do help me +write the pseudo code you can tell me + + align:start position:0% +write the pseudo code you can tell me + + + align:start position:0% +write the pseudo code you can tell me +what it + + align:start position:0% +what it + + + align:start position:0% +what it +is start midle + + align:start position:0% + + + + align:start position:0% + +okay start in the + + align:start position:0% + + + + align:start position:0% + +middle if you if you write this on uh on + + align:start position:0% +middle if you if you write this on uh on + + + align:start position:0% +middle if you if you write this on uh on +your pet you might want to be a little + + align:start position:0% +your pet you might want to be a little + + + align:start position:0% +your pet you might want to be a little +bit more formal someone asked me about + + align:start position:0% +bit more formal someone asked me about + + + align:start position:0% +bit more formal someone asked me about +proofs I would say something like start + + align:start position:0% +proofs I would say something like start + + + align:start position:0% +proofs I would say something like start +by looking at the middle element of the + + align:start position:0% +by looking at the middle element of the + + + align:start position:0% +by looking at the middle element of the +array same thing + + align:start position:0% +array same thing + + + align:start position:0% +array same thing +though + + align:start position:0% +though + + + align:start position:0% +though +okay so let's pretend this is the + + align:start position:0% +okay so let's pretend this is the + + + align:start position:0% +okay so let's pretend this is the +middle now it + + align:start position:0% +middle now it + + + align:start position:0% +middle now it +is what do I + + align:start position:0% + + + + align:start position:0% + +do okay I'm looking at the right side I + + align:start position:0% +do okay I'm looking at the right side I + + + align:start position:0% +do okay I'm looking at the right side I +see a seven there so I know for sure + + align:start position:0% +see a seven there so I know for sure + + + align:start position:0% +see a seven there so I know for sure +that this is not a local Peak + + align:start position:0% +that this is not a local Peak + + + align:start position:0% +that this is not a local Peak +right what do I do + + align:start position:0% + + + + align:start position:0% + +now okay + + align:start position:0% +now okay + + + align:start position:0% +now okay +uh what if this would be small what if I + + align:start position:0% +uh what if this would be small what if I + + + align:start position:0% +uh what if this would be small what if I +would look at five + + align:start position:0% +would look at five + + + align:start position:0% +would look at five +first or shouldn't should I look at the + + align:start position:0% +first or shouldn't should I look at the + + + align:start position:0% +first or shouldn't should I look at the +other side too well you don't have to in + + align:start position:0% +other side too well you don't have to in + + + align:start position:0% +other side too well you don't have to in +this case but if you but if seven were + + align:start position:0% +this case but if you but if seven were + + + align:start position:0% +this case but if you but if seven were +smaller then you would go and look at + + align:start position:0% +smaller then you would go and look at + + + align:start position:0% +smaller then you would go and look at +the other side to check to see five was + + align:start position:0% +the other side to check to see five was + + + align:start position:0% +the other side to check to see five was +also smaller in that case You' already + + align:start position:0% +also smaller in that case You' already + + + align:start position:0% +also smaller in that case You' already +found it okay so I have to look at both + + align:start position:0% +found it okay so I have to look at both + + + align:start position:0% +found it okay so I have to look at both +sides and make sure if none of them is + + align:start position:0% +sides and make sure if none of them is + + + align:start position:0% +sides and make sure if none of them is +smaller then I sorry if none of them is + + align:start position:0% +smaller then I sorry if none of them is + + + align:start position:0% +smaller then I sorry if none of them is +bigger I found a peak if any of them is + + align:start position:0% +bigger I found a peak if any of them is + + + align:start position:0% +bigger I found a peak if any of them is +uh bigger then I can go whichever way I + + align:start position:0% +uh bigger then I can go whichever way I + + + align:start position:0% +uh bigger then I can go whichever way I +want so I saw my seven I'm going to cut + + align:start position:0% +want so I saw my seven I'm going to cut + + + align:start position:0% +want so I saw my seven I'm going to cut +this in half and now I look at this + + align:start position:0% +this in half and now I look at this + + + align:start position:0% +this in half and now I look at this +you're saying + + align:start position:0% + + + + align:start position:0% + +right so look at + + align:start position:0% +right so look at + + + align:start position:0% +right so look at +neighbors by the way can anyone + + align:start position:0% +neighbors by the way can anyone + + + align:start position:0% +neighbors by the way can anyone +understand my handwriting is it even + + align:start position:0% +understand my handwriting is it even + + + align:start position:0% +understand my handwriting is it even +worth bothering to + + align:start position:0% +worth bothering to + + + align:start position:0% +worth bothering to +write okay I see three nods I'm going to + + align:start position:0% +write okay I see three nods I'm going to + + + align:start position:0% +write okay I see three nods I'm going to +write for those three + + align:start position:0% +write for those three + + + align:start position:0% +write for those three +people look at years + + align:start position:0% +people look at years + + + align:start position:0% +people look at years +so okay thanks not feeling old at all + + align:start position:0% +so okay thanks not feeling old at all + + + align:start position:0% +so okay thanks not feeling old at all +okay look at neighbors uh figure out if + + align:start position:0% +okay look at neighbors uh figure out if + + + align:start position:0% +okay look at neighbors uh figure out if +you're a peak you're one of the people + + align:start position:0% +you're a peak you're one of the people + + + align:start position:0% +you're a peak you're one of the people +that said you can read it so now there's + + align:start position:0% +that said you can read it so now there's + + + align:start position:0% +that said you can read it so now there's +only two people that can read my + + align:start position:0% +only two people that can read my + + + align:start position:0% +only two people that can read my +handwriting and that I + + align:start position:0% +handwriting and that I + + + align:start position:0% +handwriting and that I +like uh look at the + + align:start position:0% +like uh look at the + + + align:start position:0% +like uh look at the +neighbors see if local + + align:start position:0% + + + + align:start position:0% + +Peak + + align:start position:0% + + + + align:start position:0% + +and if not figure out which way to go + + align:start position:0% + + + + align:start position:0% + +in and I'll say if not + + align:start position:0% + + + + align:start position:0% + +recurse so what's the running time for + + align:start position:0% +recurse so what's the running time for + + + align:start position:0% +recurse so what's the running time for +this suppose I have n elements to start + + align:start position:0% +this suppose I have n elements to start + + + align:start position:0% +this suppose I have n elements to start +with that's my array size I will use T + + align:start position:0% +with that's my array size I will use T + + + align:start position:0% +with that's my array size I will use T +of + + align:start position:0% +of + + + align:start position:0% +of +n as my running time so to figure out + + align:start position:0% +n as my running time so to figure out + + + align:start position:0% +n as my running time so to figure out +the running time for the whole algorithm + + align:start position:0% +the running time for the whole algorithm + + + align:start position:0% +the running time for the whole algorithm +I have to look at the running time for + + align:start position:0% +I have to look at the running time for + + + align:start position:0% +I have to look at the running time for +each step and add them up right what's + + align:start position:0% +each step and add them up right what's + + + align:start position:0% +each step and add them up right what's +the running time for the first step look + + align:start position:0% +the running time for the first step look + + + align:start position:0% +the running time for the first step look +in the + + align:start position:0% + + + + align:start position:0% + +middle one one I I would not say it's + + align:start position:0% +middle one one I I would not say it's + + + align:start position:0% +middle one one I I would not say it's +zero I still have to look at it + + align:start position:0% +zero I still have to look at it + + + align:start position:0% +zero I still have to look at it +or to be on the safe side you say one + + align:start position:0% +or to be on the safe side you say one + + + align:start position:0% +or to be on the safe side you say one +Theta of one it's a + + align:start position:0% +Theta of one it's a + + + align:start position:0% +Theta of one it's a +constant okay now I have to look at the + + align:start position:0% +constant okay now I have to look at the + + + align:start position:0% +constant okay now I have to look at the +neighbors and I have to see if one of + + align:start position:0% +neighbors and I have to see if one of + + + align:start position:0% +neighbors and I have to see if one of +them is bigger or not how about that how + + align:start position:0% +them is bigger or not how about that how + + + align:start position:0% +them is bigger or not how about that how +much time is that + + align:start position:0% + + + + align:start position:0% + +I heard the constant okay very soft + + align:start position:0% +I heard the constant okay very soft + + + align:start position:0% +I heard the constant okay very soft +voice but I heard a constant there so + + align:start position:0% +voice but I heard a constant there so + + + align:start position:0% +voice but I heard a constant there so +I'm going to take it so this guy is a + + align:start position:0% +I'm going to take it so this guy is a + + + align:start position:0% +I'm going to take it so this guy is a +constant if it's a local pick I'm down + + align:start position:0% +constant if it's a local pick I'm down + + + align:start position:0% +constant if it's a local pick I'm down +if it's not a local pick what's the + + align:start position:0% +if it's not a local pick what's the + + + align:start position:0% +if it's not a local pick what's the +running time for + + align:start position:0% + + + + align:start position:0% + +this + + align:start position:0% +this + + + align:start position:0% +this +yep so I'm looking at this guy it's + + align:start position:0% +yep so I'm looking at this guy it's + + + align:start position:0% +yep so I'm looking at this guy it's +clearly not a peak so I'm going to look + + align:start position:0% +clearly not a peak so I'm going to look + + + align:start position:0% +clearly not a peak so I'm going to look +in the right side because I see a seven + + align:start position:0% +in the right side because I see a seven + + + align:start position:0% +in the right side because I see a seven +here that's bigger than a six so now I + + align:start position:0% +here that's bigger than a six so now I + + + align:start position:0% +here that's bigger than a six so now I +have the same problem except my array + + align:start position:0% +have the same problem except my array + + + align:start position:0% +have the same problem except my array +size just dropped to half so same + + align:start position:0% +size just dropped to half so same + + + align:start position:0% +size just dropped to half so same +problem because I already have a name + + align:start position:0% +problem because I already have a name + + + align:start position:0% +problem because I already have a name +for it except the input size is + + align:start position:0% +for it except the input size is + + + align:start position:0% +for it except the input size is +different so the running time for this + + align:start position:0% +different so the running time for this + + + align:start position:0% +different so the running time for this +entire step + + align:start position:0% +entire step + + + align:start position:0% +entire step +is Theta of 1 + T of n /2 so the running + + align:start position:0% +is Theta of 1 + T of n /2 so the running + + + align:start position:0% +is Theta of 1 + T of n /2 so the running +time for the whole thing + + align:start position:0% +time for the whole thing + + + align:start position:0% +time for the whole thing +is um I should have said Theta of 1 here + + align:start position:0% +is um I should have said Theta of 1 here + + + align:start position:0% +is um I should have said Theta of 1 here +sorry so Theta of 1 plus Theta of 1 + T + + align:start position:0% +sorry so Theta of 1 plus Theta of 1 + T + + + align:start position:0% +sorry so Theta of 1 plus Theta of 1 + T +of n / 2 so this is Theta of + + align:start position:0% +of n / 2 so this is Theta of + + + align:start position:0% +of n / 2 so this is Theta of +1+ T of n / + + align:start position:0% +1+ T of n / + + + align:start position:0% +1+ T of n / +2 so I wrote out my pseudo code looked + + align:start position:0% +2 so I wrote out my pseudo code looked + + + align:start position:0% +2 so I wrote out my pseudo code looked +at the running time for each step added + + align:start position:0% +at the running time for each step added + + + align:start position:0% +at the running time for each step added +them up now I have a recurrence and I + + align:start position:0% +them up now I have a recurrence and I + + + align:start position:0% +them up now I have a recurrence and I +have to solve it let's solve it we sort + + align:start position:0% +have to solve it let's solve it we sort + + + align:start position:0% +have to solve it let's solve it we sort +of glossed over that in lectures so + + align:start position:0% +of glossed over that in lectures so + + + align:start position:0% +of glossed over that in lectures so +we're going to do it + + align:start position:0% + + + + align:start position:0% + +now so T of n equals Theta of 1 + T of n + + align:start position:0% +now so T of n equals Theta of 1 + T of n + + + align:start position:0% +now so T of n equals Theta of 1 + T of n +/ 2 I'm going to expand this using the + + align:start position:0% +/ 2 I'm going to expand this using the + + + align:start position:0% +/ 2 I'm going to expand this using the +definition and and Theta of one is long + + align:start position:0% +definition and and Theta of one is long + + + align:start position:0% +definition and and Theta of one is long +so I'm going to call this C instead it's + + align:start position:0% +so I'm going to call this C instead it's + + + align:start position:0% +so I'm going to call this C instead it's +a constant right so C plus expanding + + align:start position:0% +a constant right so C plus expanding + + + align:start position:0% +a constant right so C plus expanding +this C + T of n / 4 I'm going to expand + + align:start position:0% +this C + T of n / 4 I'm going to expand + + + align:start position:0% +this C + T of n / 4 I'm going to expand +it + + align:start position:0% + + + + align:start position:0% + +again and + + align:start position:0% + + + + align:start position:0% + +again anyone getting bir of + + align:start position:0% +again anyone getting bir of + + + align:start position:0% +again anyone getting bir of +this so if I expand it a lot of times + + align:start position:0% +this so if I expand it a lot of times + + + align:start position:0% +this so if I expand it a lot of times +I'm going to get I * C + T of n / by 2 + + align:start position:0% +I'm going to get I * C + T of n / by 2 + + + align:start position:0% +I'm going to get I * C + T of n / by 2 +to the I and you can expand it as many + + align:start position:0% +to the I and you can expand it as many + + + align:start position:0% +to the I and you can expand it as many +times as you want until we see the + + align:start position:0% +times as you want until we see the + + + align:start position:0% +times as you want until we see the +pattern but this is the + + align:start position:0% +pattern but this is the + + + align:start position:0% +pattern but this is the +pattern so I have a recurrence what else + + align:start position:0% +pattern so I have a recurrence what else + + + align:start position:0% +pattern so I have a recurrence what else +do I need in order to get a function I + + align:start position:0% +do I need in order to get a function I + + + align:start position:0% +do I need in order to get a function I +need a base case so the problem size get + + align:start position:0% +need a base case so the problem size get + + + align:start position:0% +need a base case so the problem size get +smaller and smaller and smaller but at + + align:start position:0% +smaller and smaller and smaller but at + + + align:start position:0% +smaller and smaller and smaller but at +some point it becomes so small that I + + align:start position:0% +some point it becomes so small that I + + + align:start position:0% +some point it becomes so small that I +can solve it just by looking at it + + align:start position:0% +can solve it just by looking at it + + + align:start position:0% +can solve it just by looking at it +what's that case + + align:start position:0% + + + + align:start position:0% + +okay so if I have an array of one + + align:start position:0% +okay so if I have an array of one + + + align:start position:0% +okay so if I have an array of one +element it's a peak right job + + align:start position:0% +element it's a peak right job + + + align:start position:0% +element it's a peak right job +done so T of one + + align:start position:0% +done so T of one + + + align:start position:0% +done so T of one +is a + + align:start position:0% +is a + + + align:start position:0% +is a +constant so I want to write this in such + + align:start position:0% +constant so I want to write this in such + + + align:start position:0% +constant so I want to write this in such +a way that this + + align:start position:0% +a way that this + + + align:start position:0% +a way that this +becomes + + align:start position:0% +becomes + + + align:start position:0% +becomes +this so I want to figure out an I such + + align:start position:0% +this so I want to figure out an I such + + + align:start position:0% +this so I want to figure out an I such +that + + align:start position:0% + + + + align:start position:0% + +um yeah t of n / 2 to the I equals + + align:start position:0% +um yeah t of n / 2 to the I equals + + + align:start position:0% +um yeah t of n / 2 to the I equals +T of one and the easi way of doing that + + align:start position:0% +T of one and the easi way of doing that + + + align:start position:0% +T of one and the easi way of doing that +is to say that n / 2 to the I is 1 so I + + align:start position:0% +is to say that n / 2 to the I is 1 so I + + + align:start position:0% +is to say that n / 2 to the I is 1 so I +is the inverse of an + + align:start position:0% +is the inverse of an + + + align:start position:0% +is the inverse of an +exponential + + align:start position:0% + + + + align:start position:0% + +anyone logarithm thank + + align:start position:0% +anyone logarithm thank + + + align:start position:0% +anyone logarithm thank +you + + align:start position:0% +you + + + align:start position:0% +you +log + + align:start position:0% +log + + + align:start position:0% +log +n so I have I and I'm going to plug it + + align:start position:0% +n so I have I and I'm going to plug it + + + align:start position:0% +n so I have I and I'm going to plug it +back in here and I get constant + + align:start position:0% +back in here and I get constant + + + align:start position:0% +back in here and I get constant +times log + + align:start position:0% +times log + + + align:start position:0% +times log +n+ T of 1 which I know is Theta of + + align:start position:0% +n+ T of 1 which I know is Theta of + + + align:start position:0% +n+ T of 1 which I know is Theta of +one um I'm going to make this Theta of 1 + + align:start position:0% +one um I'm going to make this Theta of 1 + + + align:start position:0% +one um I'm going to make this Theta of 1 +again so Theta of 1 + + align:start position:0% +again so Theta of 1 + + + align:start position:0% +again so Theta of 1 +* log n+ plus Thea of 1 and I know that + + align:start position:0% +* log n+ plus Thea of 1 and I know that + + + align:start position:0% +* log n+ plus Thea of 1 and I know that +log n dominates a constant so this is + + align:start position:0% +log n dominates a constant so this is + + + align:start position:0% +log n dominates a constant so this is +going to be Theta of log + + align:start position:0% + + + + align:start position:0% + +n + + align:start position:0% + + + + align:start position:0% + +solve okay how are we + + align:start position:0% +solve okay how are we + + + align:start position:0% +solve okay how are we +doing yes and second to last from the + + align:start position:0% +doing yes and second to last from the + + + align:start position:0% +doing yes and second to last from the +bottom I + + align:start position:0% +bottom I + + + align:start position:0% +bottom I +understand + + align:start position:0% +understand + + + align:start position:0% +understand +C + + align:start position:0% +C + + + align:start position:0% +C +I and second part of equation how + + align:start position:0% +I and second part of equation how + + + align:start position:0% +I and second part of equation how +you okay so uh in the jump from here to + + align:start position:0% +you okay so uh in the jump from here to + + + align:start position:0% +you okay so uh in the jump from here to +here where I said I equals log n + + align:start position:0% +here where I said I equals log n + + + align:start position:0% +here where I said I equals log n +right okay so I becomes log n c stays C + + align:start position:0% +right okay so I becomes log n c stays C + + + align:start position:0% +right okay so I becomes log n c stays C +you're wondering about this part + + align:start position:0% +you're wondering about this part + + + align:start position:0% +you're wondering about this part +right so if I is log n then 2 to the I + + align:start position:0% +right so if I is log n then 2 to the I + + + align:start position:0% +right so if I is log n then 2 to the I +is n so I have t of one which I have + + align:start position:0% +is n so I have t of one which I have + + + align:start position:0% +is n so I have t of one which I have +here so + + align:start position:0% +here so + + + align:start position:0% +here so +I wanted to have this happen when I was + + align:start position:0% +I wanted to have this happen when I was + + + align:start position:0% +I wanted to have this happen when I was +solving for I here I set this guy to my + + align:start position:0% +solving for I here I set this guy to my + + + align:start position:0% +solving for I here I set this guy to my +base case so that I can get this to + + align:start position:0% + + + + align:start position:0% + +happen the idea here is that you're + + align:start position:0% +happen the idea here is that you're + + + align:start position:0% +happen the idea here is that you're +expanding the recursion forever and you + + align:start position:0% +expanding the recursion forever and you + + + align:start position:0% +expanding the recursion forever and you +know that at some point you're going to + + align:start position:0% +know that at some point you're going to + + + align:start position:0% +know that at some point you're going to +have to stop when do you stop you stop + + align:start position:0% +have to stop when do you stop you stop + + + align:start position:0% +have to stop when do you stop you stop +at the base case so you force this to + + align:start position:0% +at the base case so you force this to + + + align:start position:0% +at the base case so you force this to +become the base + + align:start position:0% + + + + align:start position:0% + +case + + align:start position:0% +case + + + align:start position:0% +case +okay + + align:start position:0% + + + + align:start position:0% + +okay uh let's do 2D Peak finding let's + + align:start position:0% +okay uh let's do 2D Peak finding let's + + + align:start position:0% +okay uh let's do 2D Peak finding let's +talk about it a little + + align:start position:0% + + + + align:start position:0% + +bit so 2D pick finding is exactly like + + align:start position:0% +bit so 2D pick finding is exactly like + + + align:start position:0% +bit so 2D pick finding is exactly like +1D Pi finding except you have a 2d + + align:start position:0% +1D Pi finding except you have a 2d + + + align:start position:0% +1D Pi finding except you have a 2d +Matrix instead of a 1D + + align:start position:0% +Matrix instead of a 1D + + + align:start position:0% +Matrix instead of a 1D +array + + align:start position:0% +array + + + align:start position:0% +array +uh let's see if I can do this + + align:start position:0% + + + + align:start position:0% + +right so suppose this is our Matrix and + + align:start position:0% +right so suppose this is our Matrix and + + + align:start position:0% +right so suppose this is our Matrix and +suppose + + align:start position:0% +suppose + + + align:start position:0% +suppose +these are the rows suppose we have um M + + align:start position:0% + + + + align:start position:0% + +Rose and N + + align:start position:0% + + + + align:start position:0% + +columns + + align:start position:0% + + + + align:start position:0% + +okay can anyone remind me what the + + align:start position:0% +okay can anyone remind me what the + + + align:start position:0% +okay can anyone remind me what the +pseudo code for for 2D Peak finding that + + align:start position:0% +pseudo code for for 2D Peak finding that + + + align:start position:0% +pseudo code for for 2D Peak finding that +we talked about in lecture so we had two + + align:start position:0% +we talked about in lecture so we had two + + + align:start position:0% +we talked about in lecture so we had two +attempts the first one was a clear + + align:start position:0% +attempts the first one was a clear + + + align:start position:0% +attempts the first one was a clear +failure it didn't work the second one + + align:start position:0% +failure it didn't work the second one + + + align:start position:0% +failure it didn't work the second one +worked and we talked about it running + + align:start position:0% +worked and we talked about it running + + + align:start position:0% +worked and we talked about it running +time a little bit and then FY asked you + + align:start position:0% +time a little bit and then FY asked you + + + align:start position:0% +time a little bit and then FY asked you +to think of a variation to the second + + align:start position:0% +to think of a variation to the second + + + align:start position:0% +to think of a variation to the second +one so let's do the straight up second + + align:start position:0% +one so let's do the straight up second + + + align:start position:0% +one so let's do the straight up second +uh version of the pseudo code without + + align:start position:0% +uh version of the pseudo code without + + + align:start position:0% +uh version of the pseudo code without +the + + align:start position:0% +the + + + align:start position:0% +the +variation so 2D pick + + align:start position:0% + + + + align:start position:0% + +finding + + align:start position:0% + + + + align:start position:0% + +what's the + + align:start position:0% + + + + align:start position:0% + +algorithm all right one person was not + + align:start position:0% +algorithm all right one person was not + + + align:start position:0% +algorithm all right one person was not +asleep in my section at the end of + + align:start position:0% +asleep in my section at the end of + + + align:start position:0% +asleep in my section at the end of +lecture I'm + + align:start position:0% +lecture I'm + + + align:start position:0% +lecture I'm +proud which one of + + align:start position:0% +proud which one of + + + align:start position:0% +proud which one of +us uh you had your hand up first though + + align:start position:0% +us uh you had your hand up first though + + + align:start position:0% +us uh you had your hand up first though +so you just + + align:start position:0% +so you just + + + align:start position:0% +so you just +a + + align:start position:0% +a + + + align:start position:0% +a +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and + + align:start position:0% + + + + align:start position:0% + +find + + align:start position:0% + + + + align:start position:0% + +Peak + + align:start position:0% +Peak + + + align:start position:0% +Peak +neighbors neighbors in the same + + align:start position:0% +neighbors neighbors in the same + + + align:start position:0% +neighbors neighbors in the same +row yeah yeah + + align:start position:0% +row yeah yeah + + + align:start position:0% +row yeah yeah +sorry row is the horizontal one right + + align:start position:0% +sorry row is the horizontal one right + + + align:start position:0% +sorry row is the horizontal one right +okay so what do you mean by find the + + align:start position:0% +okay so what do you mean by find the + + + align:start position:0% +okay so what do you mean by find the +peak + + align:start position:0% +peak + + + align:start position:0% +peak +here with the coln yes so find the peak + + align:start position:0% +here with the coln yes so find the peak + + + align:start position:0% +here with the coln yes so find the peak +using what we talked about before yeah + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +find One D + + align:start position:0% + + + + align:start position:0% + +peek so you're thinking ahead you're + + align:start position:0% +peek so you're thinking ahead you're + + + align:start position:0% +peek so you're thinking ahead you're +thinking of the variation that sh asked + + align:start position:0% +thinking of the variation that sh asked + + + align:start position:0% +thinking of the variation that sh asked +you guys to think about at home I'm glad + + align:start position:0% +you guys to think about at home I'm glad + + + align:start position:0% +you guys to think about at home I'm glad +you thought about it that's good but uh + + align:start position:0% +you thought about it that's good but uh + + + align:start position:0% +you thought about it that's good but uh +what's the one that we had in lecture I + + align:start position:0% +what's the one that we had in lecture I + + + align:start position:0% +what's the one that we had in lecture I +want to think about I don't want to give + + align:start position:0% +want to think about I don't want to give + + + align:start position:0% +want to think about I don't want to give +you guys the answer yet so what did we + + align:start position:0% +you guys the answer yet so what did we + + + align:start position:0% +you guys the answer yet so what did we +say we're going to do in + + align:start position:0% +say we're going to do in + + + align:start position:0% +say we're going to do in +lecture yes I think we just picked a + + align:start position:0% +lecture yes I think we just picked a + + + align:start position:0% +lecture yes I think we just picked a +spot check the neighbors and kept + + align:start position:0% +spot check the neighbors and kept + + + align:start position:0% +spot check the neighbors and kept +walking uphill if that makes sense every + + align:start position:0% +walking uphill if that makes sense every + + + align:start position:0% +walking uphill if that makes sense every +time we found a neighbor that was bigger + + align:start position:0% +time we found a neighbor that was bigger + + + align:start position:0% +time we found a neighbor that was bigger +move to that + + align:start position:0% +move to that + + + align:start position:0% +move to that +spot so this is this is the first + + align:start position:0% +spot so this is this is the first + + + align:start position:0% +spot so this is this is the first +algorithm that's slow it works you're + + align:start position:0% +algorithm that's slow it works you're + + + align:start position:0% +algorithm that's slow it works you're +going to get the correct answer but it's + + align:start position:0% +going to get the correct answer but it's + + + align:start position:0% +going to get the correct answer but it's +slow because if you have some uh handly + + align:start position:0% +slow because if you have some uh handly + + + align:start position:0% +slow because if you have some uh handly +crafted uh Matrix you can go like this + + align:start position:0% +crafted uh Matrix you can go like this + + + align:start position:0% +crafted uh Matrix you can go like this +and you're basically going through the + + align:start position:0% +and you're basically going through the + + + align:start position:0% +and you're basically going through the +whole + + align:start position:0% +whole + + + align:start position:0% +whole +Matrix yes uh I think the second + + align:start position:0% +Matrix yes uh I think the second + + + align:start position:0% +Matrix yes uh I think the second +algorithm was find a look through the + + align:start position:0% +algorithm was find a look through the + + + align:start position:0% +algorithm was find a look through the +column for its maximum and then look to + + align:start position:0% +column for its maximum and then look to + + + align:start position:0% +column for its maximum and then look to +either side okay so instead of finding a + + align:start position:0% +either side okay so instead of finding a + + + align:start position:0% +either side okay so instead of finding a +1D Peak we're going to find the maximum + + align:start position:0% + + + + align:start position:0% + +value okay and this is correct and let's + + align:start position:0% +value okay and this is correct and let's + + + align:start position:0% +value okay and this is correct and let's +look at this running + + align:start position:0% + + + + align:start position:0% + +time does anyone want to help me so this + + align:start position:0% +time does anyone want to help me so this + + + align:start position:0% +time does anyone want to help me so this +is T + + align:start position:0% +is T + + + align:start position:0% +is T +of n m right and rows and + + align:start position:0% +of n m right and rows and + + + align:start position:0% +of n m right and rows and +columns so what's the running time for + + align:start position:0% +columns so what's the running time for + + + align:start position:0% +columns so what's the running time for +the first + + align:start position:0% +the first + + + align:start position:0% +the first +step come on this is the easy one yes + + align:start position:0% +step come on this is the easy one yes + + + align:start position:0% +step come on this is the easy one yes +it's a constant + + align:start position:0% + + + + align:start position:0% + +perfect okay what's the running time for + + align:start position:0% +perfect okay what's the running time for + + + align:start position:0% +perfect okay what's the running time for +finding a maximum out of n + + align:start position:0% +finding a maximum out of n + + + align:start position:0% +finding a maximum out of n +numbers + + align:start position:0% +numbers + + + align:start position:0% +numbers +okay + + align:start position:0% +okay + + + align:start position:0% +okay +perfect and suppose we do that + + align:start position:0% +perfect and suppose we do that + + + align:start position:0% +perfect and suppose we do that +here suppose these rows don't exist + + align:start position:0% +here suppose these rows don't exist + + + align:start position:0% +here suppose these rows don't exist +suppose this is my entire Matrix and I'm + + align:start position:0% +suppose this is my entire Matrix and I'm + + + align:start position:0% +suppose this is my entire Matrix and I'm +here and I found a maximum what do I do + + align:start position:0% +here and I found a maximum what do I do + + + align:start position:0% +here and I found a maximum what do I do +I look left I look right if both of them + + align:start position:0% +I look left I look right if both of them + + + align:start position:0% +I look left I look right if both of them +are smaller then it means I found my + + align:start position:0% +are smaller then it means I found my + + + align:start position:0% +are smaller then it means I found my +Peak because I know that number was a + + align:start position:0% +Peak because I know that number was a + + + align:start position:0% +Peak because I know that number was a +maximum in my column now if that's not + + align:start position:0% +maximum in my column now if that's not + + + align:start position:0% +maximum in my column now if that's not +the case if I find a number that's + + align:start position:0% +the case if I find a number that's + + + align:start position:0% +the case if I find a number that's +bigger I'll go in that direction does + + align:start position:0% +bigger I'll go in that direction does + + + align:start position:0% +bigger I'll go in that direction does +that un + + align:start position:0% +that un + + + align:start position:0% +that un +reasonable okay so maximum for my column + + align:start position:0% +reasonable okay so maximum for my column + + + align:start position:0% +reasonable okay so maximum for my column +and I'm going to go + + align:start position:0% +and I'm going to go + + + align:start position:0% +and I'm going to go +right so check neighbors and I have the + + align:start position:0% +right so check neighbors and I have the + + + align:start position:0% +right so check neighbors and I have the +same two conditions + + align:start position:0% +same two conditions + + + align:start position:0% +same two conditions +there if it's a peak then I'm + + align:start position:0% +there if it's a peak then I'm + + + align:start position:0% +there if it's a peak then I'm +happy otherwise + + align:start position:0% +happy otherwise + + + align:start position:0% +happy otherwise +recurse so what's the running time if I + + align:start position:0% +recurse so what's the running time if I + + + align:start position:0% +recurse so what's the running time if I +have to recurse how does the new problem + + align:start position:0% +have to recurse how does the new problem + + + align:start position:0% +have to recurse how does the new problem +look + + align:start position:0% +look + + + align:start position:0% +look +like it's an identical problem I still + + align:start position:0% +like it's an identical problem I still + + + align:start position:0% +like it's an identical problem I still +have a matrix except what + + align:start position:0% +have a matrix except what + + + align:start position:0% +have a matrix except what +changed so suppose I got here and this + + align:start position:0% +changed so suppose I got here and this + + + align:start position:0% +changed so suppose I got here and this +is the middle of my Matrix and I see + + align:start position:0% +is the middle of my Matrix and I see + + + align:start position:0% +is the middle of my Matrix and I see +that this guy is bigger so I'm going to + + align:start position:0% +that this guy is bigger so I'm going to + + + align:start position:0% +that this guy is bigger so I'm going to +recurse to the right + + align:start position:0% +recurse to the right + + + align:start position:0% +recurse to the right +side what happened to my problem + + align:start position:0% + + + + align:start position:0% + +size okay sorry I'm not answering + + align:start position:0% +size okay sorry I'm not answering + + + align:start position:0% +size okay sorry I'm not answering +question but um should find Max not + + align:start position:0% +question but um should find Max not + + + align:start position:0% +question but um should find Max not +n let me see tell uh you are right thank + + align:start position:0% +n let me see tell uh you are right thank + + + align:start position:0% +n let me see tell uh you are right thank +you for paying + + align:start position:0% +you for paying + + + align:start position:0% +you for paying +attention there I am sweet that would + + align:start position:0% +attention there I am sweet that would + + + align:start position:0% +attention there I am sweet that would +have Tri me up later thanks for saving + + align:start position:0% +have Tri me up later thanks for saving + + + align:start position:0% +have Tri me up later thanks for saving +me okay so your question sorry so the + + align:start position:0% +me okay so your question sorry so the + + + align:start position:0% +me okay so your question sorry so the +question is if I have to + + align:start position:0% +question is if I have to + + + align:start position:0% +question is if I have to +recurse what's the running + + align:start position:0% + + + + align:start position:0% + +time so I'm if I have to recurse I'm in + + align:start position:0% +time so I'm if I have to recurse I'm in + + + align:start position:0% +time so I'm if I have to recurse I'm in +this array that was originally n by + + align:start position:0% +this array that was originally n by + + + align:start position:0% +this array that was originally n by +m and I'm only going to look at the + + align:start position:0% +m and I'm only going to look at the + + + align:start position:0% +m and I'm only going to look at the +right + + align:start position:0% + + + + align:start position:0% + +side how + + align:start position:0% +side how + + + align:start position:0% +side how +many these how many rows do I have in + + align:start position:0% +many these how many rows do I have in + + + align:start position:0% +many these how many rows do I have in +the new array start with a easy + + align:start position:0% + + + + align:start position:0% + +one all right same as + + align:start position:0% +one all right same as + + + align:start position:0% +one all right same as +before how many + + align:start position:0% +before how many + + + align:start position:0% +before how many +columns n/ + + align:start position:0% +columns n/ + + + align:start position:0% +columns n/ +two sweet so the recursion for this is + + align:start position:0% +two sweet so the recursion for this is + + + align:start position:0% +two sweet so the recursion for this is +Theta of 1 plus Theta of + + align:start position:0% +Theta of 1 plus Theta of + + + align:start position:0% +Theta of 1 plus Theta of +M plus T + + align:start position:0% +M plus T + + + align:start position:0% +M plus T +of n / 2 and + + align:start position:0% +of n / 2 and + + + align:start position:0% +of n / 2 and +M uh I know that a constant can be + + align:start position:0% +M uh I know that a constant can be + + + align:start position:0% +M uh I know that a constant can be +absorbed by this other guy so it's Theta + + align:start position:0% +absorbed by this other guy so it's Theta + + + align:start position:0% +absorbed by this other guy so it's Theta +of M plus T of n / 2 + + align:start position:0% +of M plus T of n / 2 + + + align:start position:0% +of M plus T of n / 2 +m how would I solve + + align:start position:0% + + + + align:start position:0% + +this what's the first thing that we + + align:start position:0% +this what's the first thing that we + + + align:start position:0% +this what's the first thing that we +need yes figure out base case all right + + align:start position:0% +need yes figure out base case all right + + + align:start position:0% +need yes figure out base case all right +excellent base case what's the B what's + + align:start position:0% +excellent base case what's the B what's + + + align:start position:0% +excellent base case what's the B what's +the base + + align:start position:0% + + + + align:start position:0% + +case T of one comma G of n m sorry + + align:start position:0% + + + + align:start position:0% + +nice + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +sweet so if I only have one column + + align:start position:0% +sweet so if I only have one column + + + align:start position:0% +sweet so if I only have one column +then I can do I can find the maximum and + + align:start position:0% +then I can do I can find the maximum and + + + align:start position:0% +then I can do I can find the maximum and +I know for sure that's going to be a + + align:start position:0% +I know for sure that's going to be a + + + align:start position:0% +I know for sure that's going to be a +peak job done that's my base case so I'm + + align:start position:0% +peak job done that's my base case so I'm + + + align:start position:0% +peak job done that's my base case so I'm +going to reduce the problem size in half + + align:start position:0% +going to reduce the problem size in half + + + align:start position:0% +going to reduce the problem size in half +until I get to a single column then I + + align:start position:0% +until I get to a single column then I + + + align:start position:0% +until I get to a single column then I +find the peak there and I'm + + align:start position:0% +find the peak there and I'm + + + align:start position:0% +find the peak there and I'm +happy uh how would I solve this + + align:start position:0% + + + + align:start position:0% + +recurrence it's a one minute answer + + align:start position:0% +recurrence it's a one minute answer + + + align:start position:0% +recurrence it's a one minute answer +because I think that's exactly how much + + align:start position:0% +because I think that's exactly how much + + + align:start position:0% +because I think that's exactly how much +time we have as a + + align:start position:0% + + + + align:start position:0% + +hint + + align:start position:0% + + + + align:start position:0% + +come on guys this looks familiar + + align:start position:0% +come on guys this looks familiar + + + align:start position:0% +come on guys this looks familiar +yes exactly + + align:start position:0% +yes exactly + + + align:start position:0% +yes exactly +function exactly M never changes right + + align:start position:0% +function exactly M never changes right + + + align:start position:0% +function exactly M never changes right +so this is basically a function of n so + + align:start position:0% +so this is basically a function of n so + + + align:start position:0% +so this is basically a function of n so +if M never changes and I pretend that + + align:start position:0% +if M never changes and I pretend that + + + align:start position:0% +if M never changes and I pretend that +it's a constant this looks exactly like + + align:start position:0% +it's a constant this looks exactly like + + + align:start position:0% +it's a constant this looks exactly like +the recursion the recurrence that we Sol + + align:start position:0% +the recursion the recurrence that we Sol + + + align:start position:0% +the recursion the recurrence that we Sol +before T of N is a constant plus T of n + + align:start position:0% +before T of N is a constant plus T of n + + + align:start position:0% +before T of N is a constant plus T of n +uh over + + align:start position:0% +uh over + + + align:start position:0% +uh over +two + + align:start position:0% +two + + + align:start position:0% +two +so I'm going to get that + + align:start position:0% +so I'm going to get that + + + align:start position:0% +so I'm going to get that +constant multiplied by log n which is + + align:start position:0% +constant multiplied by log n which is + + + align:start position:0% +constant multiplied by log n which is +the solution that I had before so the + + align:start position:0% +the solution that I had before so the + + + align:start position:0% +the solution that I had before so the +running time is Theta of M log + + align:start position:0% +running time is Theta of M log + + + align:start position:0% +running time is Theta of M log +n all right I think I have 30 seconds so + + align:start position:0% +n all right I think I have 30 seconds so + + + align:start position:0% +n all right I think I have 30 seconds so +what if I would choose what if I would + + align:start position:0% +what if I would choose what if I would + + + align:start position:0% +what if I would choose what if I would +try to do this algorithm instead it's + + align:start position:0% +try to do this algorithm instead it's + + + align:start position:0% +try to do this algorithm instead it's +another one minute question so I guess + + align:start position:0% +another one minute question so I guess + + + align:start position:0% +another one minute question so I guess +I'm cheating I'm taking time away sorry + + align:start position:0% +I'm cheating I'm taking time away sorry + + + align:start position:0% +I'm cheating I'm taking time away sorry +so what if I would be finding a One D + + align:start position:0% +so what if I would be finding a One D + + + align:start position:0% +so what if I would be finding a One D +Peak instead of finding a + + align:start position:0% + + + + align:start position:0% + +maximum I'm looking at the running time + + align:start position:0% +maximum I'm looking at the running time + + + align:start position:0% +maximum I'm looking at the running time +because if the running time is going to + + align:start position:0% +because if the running time is going to + + + align:start position:0% +because if the running time is going to +be the same is not even worth thinking + + align:start position:0% +be the same is not even worth thinking + + + align:start position:0% +be the same is not even worth thinking +if it's correct or not if it's a more + + align:start position:0% +if it's correct or not if it's a more + + + align:start position:0% +if it's correct or not if it's a more +complicated algorithm with the same + + align:start position:0% +complicated algorithm with the same + + + align:start position:0% +complicated algorithm with the same +running time why care about it so is the + + align:start position:0% +running time why care about it so is the + + + align:start position:0% +running time why care about it so is the +running time going to be + + align:start position:0% +running time going to be + + + align:start position:0% +running time going to be +better okay I heard an OD + + align:start position:0% + + + + align:start position:0% + +why all right so One D Pick is exactly + + align:start position:0% +why all right so One D Pick is exactly + + + align:start position:0% +why all right so One D Pick is exactly +what we have there thank you one D Pick + + align:start position:0% +what we have there thank you one D Pick + + + align:start position:0% +what we have there thank you one D Pick +is is exactly like you said log M so + + align:start position:0% +is is exactly like you said log M so + + + align:start position:0% +is is exactly like you said log M so +this constant here becomes this constant + + align:start position:0% +this constant here becomes this constant + + + align:start position:0% +this constant here becomes this constant +here so the algorithm would be a lot + + align:start position:0% +here so the algorithm would be a lot + + + align:start position:0% +here so the algorithm would be a lot +faster U as an order of magnitude idea + + align:start position:0% +faster U as an order of magnitude idea + + + align:start position:0% +faster U as an order of magnitude idea +if your M and N are 1 million each then + + align:start position:0% +if your M and N are 1 million each then + + + align:start position:0% +if your M and N are 1 million each then +log n is 20 so that's a 50 time x + + align:start position:0% +log n is 20 so that's a 50 time x + + + align:start position:0% +log n is 20 so that's a 50 time x +Improvement and these are real input + + align:start position:0% +Improvement and these are real input + + + align:start position:0% +Improvement and these are real input +sizes you might + + align:start position:0% +sizes you might + + + align:start position:0% +sizes you might +get and that's it thank you guys \ No newline at end of file diff --git a/PKbah48l3AU.txt b/PKbah48l3AU.txt new file mode 100644 index 0000000000000000000000000000000000000000..b8bc7885e79a5c73843ee745d34085d13c96fd86 --- /dev/null +++ b/PKbah48l3AU.txt @@ -0,0 +1,8619 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT OpenCourseWare continue to + + align:start position:0% +will help MIT OpenCourseWare continue to + + + align:start position:0% +will help MIT OpenCourseWare continue to +offer high quality educational resources + + align:start position:0% +offer high quality educational resources + + + align:start position:0% +offer high quality educational resources +for free + + align:start position:0% +for free + + + align:start position:0% +for free +to make a donation or to view additional + + align:start position:0% +to make a donation or to view additional + + + align:start position:0% +to make a donation or to view additional +materials from hundreds of MIT courses + + align:start position:0% +materials from hundreds of MIT courses + + + align:start position:0% +materials from hundreds of MIT courses +visit MIT opencourseware at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +okay well everyone's quieted down so + + align:start position:0% +okay well everyone's quieted down so + + + align:start position:0% +okay well everyone's quieted down so +that means we have to get started + + align:start position:0% +that means we have to get started + + + align:start position:0% +that means we have to get started +someone must say something here this + + align:start position:0% +someone must say something here this + + + align:start position:0% +someone must say something here this +will be our last our last conversation + + align:start position:0% +will be our last our last conversation + + + align:start position:0% +will be our last our last conversation +about optimization + + align:start position:0% +about optimization + + + align:start position:0% +about optimization +okay so we've discussed unconstrained + + align:start position:0% +okay so we've discussed unconstrained + + + align:start position:0% +okay so we've discussed unconstrained +optimization and then we're going to + + align:start position:0% +optimization and then we're going to + + + align:start position:0% +optimization and then we're going to +discuss slightly more complicated + + align:start position:0% +discuss slightly more complicated + + + align:start position:0% +discuss slightly more complicated +problem but you're gonna see it's it's + + align:start position:0% +problem but you're gonna see it's it's + + + align:start position:0% +problem but you're gonna see it's it's +really not that much more complicated + + align:start position:0% +really not that much more complicated + + + align:start position:0% +really not that much more complicated +constrained optimization these are the + + align:start position:0% +constrained optimization these are the + + + align:start position:0% +constrained optimization these are the +things we discussed before I don't want + + align:start position:0% +things we discussed before I don't want + + + align:start position:0% +things we discussed before I don't want +to spend much time recapping because I + + align:start position:0% +to spend much time recapping because I + + + align:start position:0% +to spend much time recapping because I +want to I want to take a minute and talk + + align:start position:0% +want to I want to take a minute and talk + + + align:start position:0% +want to I want to take a minute and talk +about the midterm exam okay all right so + + align:start position:0% +about the midterm exam okay all right so + + + align:start position:0% +about the midterm exam okay all right so +we have a quiz + + align:start position:0% +we have a quiz + + + align:start position:0% +we have a quiz +it's next Wednesday here's where it's + + align:start position:0% +it's next Wednesday here's where it's + + + align:start position:0% +it's next Wednesday here's where it's +gonna be located right here 66 head down + + align:start position:0% +gonna be located right here 66 head down + + + align:start position:0% +gonna be located right here 66 head down +Ames you're looking for Walker Memorial + + align:start position:0% +Ames you're looking for Walker Memorial + + + align:start position:0% +Ames you're looking for Walker Memorial +on the third floor okay unfortunately + + align:start position:0% +on the third floor okay unfortunately + + + align:start position:0% +on the third floor okay unfortunately +the time for the quiz is 7:00 to 9:00 + + align:start position:0% +the time for the quiz is 7:00 to 9:00 + + + align:start position:0% +the time for the quiz is 7:00 to 9:00 +p.m. we really did try hard to get the + + align:start position:0% +p.m. we really did try hard to get the + + + align:start position:0% +p.m. we really did try hard to get the +scheduling office to give us something + + align:start position:0% +scheduling office to give us something + + + align:start position:0% +scheduling office to give us something +better but the only way to get a room + + align:start position:0% +better but the only way to get a room + + + align:start position:0% +better but the only way to get a room +that would fit everybody in was to do it + + align:start position:0% +that would fit everybody in was to do it + + + align:start position:0% +that would fit everybody in was to do it +at this time in Walker I really don't + + align:start position:0% +at this time in Walker I really don't + + + align:start position:0% +at this time in Walker I really don't +understand because I actually requested + + align:start position:0% +understand because I actually requested + + + align:start position:0% +understand because I actually requested +locations for the quizzes back in April + + align:start position:0% +locations for the quizzes back in April + + + align:start position:0% +locations for the quizzes back in April +and somehow I was I know too early maybe + + align:start position:0% +and somehow I was I know too early maybe + + + align:start position:0% +and somehow I was I know too early maybe +and got buried under a pile may be not + + align:start position:0% +and got buried under a pile may be not + + + align:start position:0% +and got buried under a pile may be not +important enough I don't know but it's + + align:start position:0% +important enough I don't know but it's + + + align:start position:0% +important enough I don't know but it's +gonna be from 7:00 to 9:00 next + + align:start position:0% +gonna be from 7:00 to 9:00 next + + + align:start position:0% +gonna be from 7:00 to 9:00 next +Wednesday right third floor there's not + + align:start position:0% +Wednesday right third floor there's not + + + align:start position:0% +Wednesday right third floor there's not +gonna be any class next Wednesday + + align:start position:0% +gonna be any class next Wednesday + + + align:start position:0% +gonna be any class next Wednesday +because you have a quiz instead to get a + + align:start position:0% +because you have a quiz instead to get a + + + align:start position:0% +because you have a quiz instead to get a +little extra time to relax or study + + align:start position:0% +little extra time to relax or study + + + align:start position:0% +little extra time to relax or study +prepare + + align:start position:0% +prepare + + + align:start position:0% +prepare +calm yourself before you go into the + + align:start position:0% +calm yourself before you go into the + + + align:start position:0% +calm yourself before you go into the +exam there's no homework this week okay + + align:start position:0% +exam there's no homework this week okay + + + align:start position:0% +exam there's no homework this week okay +so you can just use this time to focus + + align:start position:0% +so you can just use this time to focus + + + align:start position:0% +so you can just use this time to focus +on focus on the material we've discussed + + align:start position:0% +on focus on the material we've discussed + + + align:start position:0% +on focus on the material we've discussed +there's a practice exam from last year + + align:start position:0% +there's a practice exam from last year + + + align:start position:0% +there's a practice exam from last year +posted on the stellar site which you can + + align:start position:0% +posted on the stellar site which you can + + + align:start position:0% +posted on the stellar site which you can +utilize and study from I'll tell you + + align:start position:0% +utilize and study from I'll tell you + + + align:start position:0% +utilize and study from I'll tell you +this that practice exam a practice exam + + align:start position:0% +this that practice exam a practice exam + + + align:start position:0% +this that practice exam a practice exam +is hewed a little more towards some + + align:start position:0% +is hewed a little more towards some + + + align:start position:0% +is hewed a little more towards some +chemical engineering problems that + + align:start position:0% +chemical engineering problems that + + + align:start position:0% +chemical engineering problems that +motivate the numerix I found in the past + + align:start position:0% +motivate the numerix I found in the past + + + align:start position:0% +motivate the numerix I found in the past +that when problems like that are given + + align:start position:0% +that when problems like that are given + + + align:start position:0% +that when problems like that are given +on the exam sometimes there's a lot of + + align:start position:0% +on the exam sometimes there's a lot of + + + align:start position:0% +on the exam sometimes there's a lot of +reading that goes into understanding the + + align:start position:0% +reading that goes into understanding the + + + align:start position:0% +reading that goes into understanding the +engineering problem and that tends to + + align:start position:0% +engineering problem and that tends to + + + align:start position:0% +engineering problem and that tends to +set back the problem solving so I'll + + align:start position:0% +set back the problem solving so I'll + + + align:start position:0% +set back the problem solving so I'll +tell you that the + + align:start position:0% +tell you that the + + + align:start position:0% +tell you that the +is that you'll take on Wednesday will + + align:start position:0% +is that you'll take on Wednesday will + + + align:start position:0% +is that you'll take on Wednesday will +have less of the engineering associated + + align:start position:0% +have less of the engineering associated + + + align:start position:0% +have less of the engineering associated +with it and focus more on the numerical + + align:start position:0% +with it and focus more on the numerical + + + align:start position:0% +with it and focus more on the numerical +or computational science the underlying + + align:start position:0% +or computational science the underlying + + + align:start position:0% +or computational science the underlying +sorts of questions the way the questions + + align:start position:0% +sorts of questions the way the questions + + + align:start position:0% +sorts of questions the way the questions +are asked the kinds of responses you're + + align:start position:0% +are asked the kinds of responses you're + + + align:start position:0% +are asked the kinds of responses you're +expected to give by I'd say are very + + align:start position:0% +expected to give by I'd say are very + + + align:start position:0% +expected to give by I'd say are very +similar but we've tried to tune the + + align:start position:0% +similar but we've tried to tune the + + + align:start position:0% +similar but we've tried to tune the +exams so that it'll be less of a burden + + align:start position:0% +exams so that it'll be less of a burden + + + align:start position:0% +exams so that it'll be less of a burden +to understand the structure of the + + align:start position:0% +to understand the structure of the + + + align:start position:0% +to understand the structure of the +problem before describing how you solve + + align:start position:0% +problem before describing how you solve + + + align:start position:0% +problem before describing how you solve +it I think that's good it's + + align:start position:0% +it I think that's good it's + + + align:start position:0% +it I think that's good it's +comprehensive up to today okay so linear + + align:start position:0% +comprehensive up to today okay so linear + + + align:start position:0% +comprehensive up to today okay so linear +algebra systems of nonlinear equations + + align:start position:0% +algebra systems of nonlinear equations + + + align:start position:0% +algebra systems of nonlinear equations +and optimization are the quiz topics + + align:start position:0% +and optimization are the quiz topics + + + align:start position:0% +and optimization are the quiz topics +we're gonna switch on Friday to ordinary + + align:start position:0% +we're gonna switch on Friday to ordinary + + + align:start position:0% +we're gonna switch on Friday to ordinary +differential equations and initial value + + align:start position:0% +differential equations and initial value + + + align:start position:0% +differential equations and initial value +problems so you have two lectures on + + align:start position:0% +problems so you have two lectures on + + + align:start position:0% +problems so you have two lectures on +that but you won't have done any + + align:start position:0% +that but you won't have done any + + + align:start position:0% +that but you won't have done any +homework you probably don't know enough + + align:start position:0% +homework you probably don't know enough + + + align:start position:0% +homework you probably don't know enough +or practiced enough to answer any + + align:start position:0% +or practiced enough to answer any + + + align:start position:0% +or practiced enough to answer any +questions intelligently on the quiz + + align:start position:0% +questions intelligently on the quiz + + + align:start position:0% +questions intelligently on the quiz +don't expect that material to be on + + align:start position:0% +don't expect that material to be on + + + align:start position:0% +don't expect that material to be on +there it's not right it's gonna be these + + align:start position:0% +there it's not right it's gonna be these + + + align:start position:0% +there it's not right it's gonna be these +three topics are there any questions + + align:start position:0% +three topics are there any questions + + + align:start position:0% +three topics are there any questions +about this that I can answer crystal + + align:start position:0% + + + + align:start position:0% + +okay so yeah come come come prepared it + + align:start position:0% +okay so yeah come come come prepared it + + + align:start position:0% +okay so yeah come come come prepared it +might be cold it might be hot it leaks + + align:start position:0% +might be cold it might be hot it leaks + + + align:start position:0% +might be cold it might be hot it leaks +when it rains a little bit yeah it's not + + align:start position:0% +when it rains a little bit yeah it's not + + + align:start position:0% +when it rains a little bit yeah it's not +the not the greatest spot uh so come + + align:start position:0% +the not the greatest spot uh so come + + + align:start position:0% +the not the greatest spot uh so come +come come prepared that's true + + align:start position:0% +come come prepared that's true + + + align:start position:0% +come come prepared that's true +other questions things you want to know + + align:start position:0% +other questions things you want to know + + + align:start position:0% +other questions things you want to know +ooh good question so you can bring you + + align:start position:0% +ooh good question so you can bring you + + + align:start position:0% +ooh good question so you can bring you +can bring the book recommend it for the + + align:start position:0% +can bring the book recommend it for the + + + align:start position:0% +can bring the book recommend it for the +course you can bring your notes you can + + align:start position:0% +course you can bring your notes you can + + + align:start position:0% +course you can bring your notes you can +bring in calculator you need to bring + + align:start position:0% +bring in calculator you need to bring + + + align:start position:0% +bring in calculator you need to bring +some pencils will provide blue books for + + align:start position:0% +some pencils will provide blue books for + + + align:start position:0% +some pencils will provide blue books for +you okay to write your solutions to the + + align:start position:0% +you okay to write your solutions to the + + + align:start position:0% +you okay to write your solutions to the +exam in and so those are the materials + + align:start position:0% +exam in and so those are the materials + + + align:start position:0% +exam in and so those are the materials +good what else same question + + align:start position:0% +good what else same question + + + align:start position:0% +good what else same question +okay other questions + + align:start position:0% + + + + align:start position:0% + +them okay so then let's jump into the + + align:start position:0% +them okay so then let's jump into the + + + align:start position:0% +them okay so then let's jump into the +topic of the day which is constrained + + align:start position:0% +topic of the day which is constrained + + + align:start position:0% +topic of the day which is constrained +optimization okay so these are problems + + align:start position:0% +optimization okay so these are problems + + + align:start position:0% +optimization okay so these are problems +of the sort right minimize an objective + + align:start position:0% +of the sort right minimize an objective + + + align:start position:0% +of the sort right minimize an objective +function f of X subject to the + + align:start position:0% +function f of X subject to the + + + align:start position:0% +function f of X subject to the +constraint right that X belongs to some + + align:start position:0% +constraint right that X belongs to some + + + align:start position:0% +constraint right that X belongs to some +set D or find the argument X that + + align:start position:0% +set D or find the argument X that + + + align:start position:0% +set D or find the argument X that +minimizes this function these are + + align:start position:0% +minimizes this function these are + + + align:start position:0% +minimizes this function these are +equivalent sorts of problems sometimes + + align:start position:0% +equivalent sorts of problems sometimes + + + align:start position:0% +equivalent sorts of problems sometimes +who want to know one or the other or + + align:start position:0% +who want to know one or the other or + + + align:start position:0% +who want to know one or the other or +both that's not a problem and + + align:start position:0% +both that's not a problem and + + + align:start position:0% +both that's not a problem and +graphically it looks like this here's F + + align:start position:0% +graphically it looks like this here's F + + + align:start position:0% +graphically it looks like this here's F +our objective function it's a nice + + align:start position:0% +our objective function it's a nice + + + align:start position:0% +our objective function it's a nice +convex bowl-shaped function here and we + + align:start position:0% +convex bowl-shaped function here and we + + + align:start position:0% +convex bowl-shaped function here and we +want to know the values of x1 and x2 + + align:start position:0% +want to know the values of x1 and x2 + + + align:start position:0% +want to know the values of x1 and x2 +let's say that minimize this function + + align:start position:0% +let's say that minimize this function + + + align:start position:0% +let's say that minimize this function +subject to some constraint that + + align:start position:0% +subject to some constraint that + + + align:start position:0% +subject to some constraint that +constraint could be that x1 and x2 live + + align:start position:0% +constraint could be that x1 and x2 live + + + align:start position:0% +constraint could be that x1 and x2 live +inside this little blue circle could be + + align:start position:0% +inside this little blue circle could be + + + align:start position:0% +inside this little blue circle could be +D could be that x1 and x2 live on the + + align:start position:0% +D could be that x1 and x2 live on the + + + align:start position:0% +D could be that x1 and x2 live on the +surface of this circle right on the + + align:start position:0% +surface of this circle right on the + + + align:start position:0% +surface of this circle right on the +circumference of this circle that could + + align:start position:0% +circumference of this circle that could + + + align:start position:0% +circumference of this circle that could +be the constraint okay so these are the + + align:start position:0% +be the constraint okay so these are the + + + align:start position:0% +be the constraint okay so these are the +sorts of problems we want to solve D is + + align:start position:0% +sorts of problems we want to solve D is + + + align:start position:0% +sorts of problems we want to solve D is +called the feasible set right they can + + align:start position:0% +called the feasible set right they can + + + align:start position:0% +called the feasible set right they can +be described in terms of really two + + align:start position:0% +be described in terms of really two + + + align:start position:0% +be described in terms of really two +types of constraints one is what we call + + align:start position:0% +types of constraints one is what we call + + + align:start position:0% +types of constraints one is what we call +equality constraints so D can be the set + + align:start position:0% +equality constraints so D can be the set + + + align:start position:0% +equality constraints so D can be the set +of values X such that some non linear + + align:start position:0% +of values X such that some non linear + + + align:start position:0% +of values X such that some non linear +function C of X is equal to 0 ok so it's + + align:start position:0% +function C of X is equal to 0 ok so it's + + + align:start position:0% +function C of X is equal to 0 ok so it's +the set of points that satisfy this + + align:start position:0% +the set of points that satisfy this + + + align:start position:0% +the set of points that satisfy this +non-linear equation and among those + + align:start position:0% +non-linear equation and among those + + + align:start position:0% +non-linear equation and among those +points we want to know which one + + align:start position:0% +points we want to know which one + + + align:start position:0% +points we want to know which one +produces the minimum in the objective + + align:start position:0% +produces the minimum in the objective + + + align:start position:0% +produces the minimum in the objective +function or it could be an inequality + + align:start position:0% +function or it could be an inequality + + + align:start position:0% +function or it could be an inequality +constraint so D could be the set of + + align:start position:0% +constraint so D could be the set of + + + align:start position:0% +constraint so D could be the set of +points such that some nonlinear function + + align:start position:0% +points such that some nonlinear function + + + align:start position:0% +points such that some nonlinear function +H of X is by convention positive ok so H + + align:start position:0% +H of X is by convention positive ok so H + + + align:start position:0% +H of X is by convention positive ok so H +of X could represent for example the + + align:start position:0% +of X could represent for example the + + + align:start position:0% +of X could represent for example the +interior of a circle and C of X could + + align:start position:0% +interior of a circle and C of X could + + + align:start position:0% +interior of a circle and C of X could +represent the circumference of a circle + + align:start position:0% +represent the circumference of a circle + + + align:start position:0% +represent the circumference of a circle +right and we would have nonlinear + + align:start position:0% +right and we would have nonlinear + + + align:start position:0% +right and we would have nonlinear +equations that reflect those values of X + + align:start position:0% +equations that reflect those values of X + + + align:start position:0% +equations that reflect those values of X +that satisfy satisfied those sorts of + + align:start position:0% +that satisfy satisfied those sorts of + + + align:start position:0% +that satisfy satisfied those sorts of +geometries okay so equality constraint + + align:start position:0% +geometries okay so equality constraint + + + align:start position:0% +geometries okay so equality constraint +right points that lie on this circle + + align:start position:0% +right points that lie on this circle + + + align:start position:0% +right points that lie on this circle +inequality constraint points that lie + + align:start position:0% +inequality constraint points that lie + + + align:start position:0% +inequality constraint points that lie +within this circle the shape of the + + align:start position:0% +within this circle the shape of the + + + align:start position:0% +within this circle the shape of the +feasible set is constrained by the + + align:start position:0% +feasible set is constrained by the + + + align:start position:0% +feasible set is constrained by the +problem that you're actually interested + + align:start position:0% +problem that you're actually interested + + + align:start position:0% +problem that you're actually interested +in right so it's easy for me to draw + + align:start position:0% +in right so it's easy for me to draw + + + align:start position:0% +in right so it's easy for me to draw +circles in the plane because that's + + align:start position:0% +circles in the plane because that's + + + align:start position:0% +circles in the plane because that's +shape you're familiar with but actually + + align:start position:0% +shape you're familiar with but actually + + + align:start position:0% +shape you're familiar with but actually +it'll come from some sort of physical + + align:start position:0% +it'll come from some sort of physical + + + align:start position:0% +it'll come from some sort of physical +constraint on the engineering problem + + align:start position:0% +constraint on the engineering problem + + + align:start position:0% +constraint on the engineering problem +you're looking at like mole fractions + + align:start position:0% +you're looking at like mole fractions + + + align:start position:0% +you're looking at like mole fractions +need to be bigger than zero and smaller + + align:start position:0% +need to be bigger than zero and smaller + + + align:start position:0% +need to be bigger than zero and smaller +than one in temperatures an absolute + + align:start position:0% +than one in temperatures an absolute + + + align:start position:0% +than one in temperatures an absolute +value you have to be bigger than zero + + align:start position:0% +value you have to be bigger than zero + + + align:start position:0% +value you have to be bigger than zero +and smaller than some value because + + align:start position:0% +and smaller than some value because + + + align:start position:0% +and smaller than some value because +that's a safety factor on the process + + align:start position:0% +that's a safety factor on the process + + + align:start position:0% +that's a safety factor on the process +right so these are the set up right the + + align:start position:0% +right so these are the set up right the + + + align:start position:0% +right so these are the set up right the +constraints on various sorts of + + align:start position:0% +constraints on various sorts of + + + align:start position:0% +constraints on various sorts of +optimization problems that we're + + align:start position:0% +optimization problems that we're + + + align:start position:0% +optimization problems that we're +interested in it could also be true that + + align:start position:0% +interested in it could also be true that + + + align:start position:0% +interested in it could also be true that +we're interested in say optimization in + + align:start position:0% +we're interested in say optimization in + + + align:start position:0% +we're interested in say optimization in +the domain outside of this circle - it + + align:start position:0% +the domain outside of this circle - it + + + align:start position:0% +the domain outside of this circle - it +could be on the inside could be on the + + align:start position:0% +could be on the inside could be on the + + + align:start position:0% +could be on the inside could be on the +outside right that's also an inequality + + align:start position:0% +outside right that's also an inequality + + + align:start position:0% +outside right that's also an inequality +constrained sort of problem you know + + align:start position:0% +constrained sort of problem you know + + + align:start position:0% +constrained sort of problem you know +some of these already ok they're + + align:start position:0% +some of these already ok they're + + + align:start position:0% +some of these already ok they're +familiar to you so here's a classic one + + align:start position:0% +familiar to you so here's a classic one + + + align:start position:0% +familiar to you so here's a classic one +from mechanics right here's the total + + align:start position:0% +from mechanics right here's the total + + + align:start position:0% +from mechanics right here's the total +energy in a system for say a pendulum + + align:start position:0% +energy in a system for say a pendulum + + + align:start position:0% +energy in a system for say a pendulum +right so X is like the position of the + + align:start position:0% +right so X is like the position of the + + + align:start position:0% +right so X is like the position of the +tip of this pendulum and V is the + + align:start position:0% +tip of this pendulum and V is the + + + align:start position:0% +tip of this pendulum and V is the +velocity that it moves with this is the + + align:start position:0% +velocity that it moves with this is the + + + align:start position:0% +velocity that it moves with this is the +kinetic energy this is the potential + + align:start position:0% +kinetic energy this is the potential + + + align:start position:0% +kinetic energy this is the potential +energy and we know the pendulum will + + align:start position:0% +energy and we know the pendulum will + + + align:start position:0% +energy and we know the pendulum will +come to rest in a place where the energy + + align:start position:0% +come to rest in a place where the energy + + + align:start position:0% +come to rest in a place where the energy +is minimized right well the energy can + + align:start position:0% +is minimized right well the energy can + + + align:start position:0% +is minimized right well the energy can +only be minimized when the velocity here + + align:start position:0% +only be minimized when the velocity here + + + align:start position:0% +only be minimized when the velocity here +is zero because any nonzero velocity + + align:start position:0% +is zero because any nonzero velocity + + + align:start position:0% +is zero because any nonzero velocity +will always push the energy content up + + align:start position:0% +will always push the energy content up + + + align:start position:0% +will always push the energy content up +so it comes to rest right it doesn't + + align:start position:0% +so it comes to rest right it doesn't + + + align:start position:0% +so it comes to rest right it doesn't +move right and then there's some value + + align:start position:0% +move right and then there's some value + + + align:start position:0% +move right and then there's some value +of x at which the energy is minimized if + + align:start position:0% +of x at which the energy is minimized if + + + align:start position:0% +of x at which the energy is minimized if +there is no constraint that says that + + align:start position:0% +there is no constraint that says that + + + align:start position:0% +there is no constraint that says that +the pendulum is attached to some central + + align:start position:0% +the pendulum is attached to some central + + + align:start position:0% +the pendulum is attached to some central +axis then I can always make the energy + + align:start position:0% +axis then I can always make the energy + + + align:start position:0% +axis then I can always make the energy +smaller by making X more and more + + align:start position:0% +smaller by making X more and more + + + align:start position:0% +smaller by making X more and more +negative it just keeps falling right + + align:start position:0% +negative it just keeps falling right + + + align:start position:0% +negative it just keeps falling right +there is no stopping point but there's a + + align:start position:0% +there is no stopping point but there's a + + + align:start position:0% +there is no stopping point but there's a +constraint right the distance between + + align:start position:0% +constraint right the distance between + + + align:start position:0% +constraint right the distance between +the tip of the pendulum in this central + + align:start position:0% +the tip of the pendulum in this central + + + align:start position:0% +the tip of the pendulum in this central +point there is some fixed distance out + + align:start position:0% +point there is some fixed distance out + + + align:start position:0% +point there is some fixed distance out +so this is an equality constraint sort + + align:start position:0% +so this is an equality constraint sort + + + align:start position:0% +so this is an equality constraint sort +of problem and we have to choose from + + align:start position:0% +of problem and we have to choose from + + + align:start position:0% +of problem and we have to choose from +the set of V and X the values subject to + + align:start position:0% +the set of V and X the values subject to + + + align:start position:0% +the set of V and X the values subject to +this constraint that minimized the total + + align:start position:0% +this constraint that minimized the total + + + align:start position:0% +this constraint that minimized the total +energy and that's that's this + + align:start position:0% +energy and that's that's this + + + align:start position:0% +energy and that's that's this +configuration of the pendulum here so + + align:start position:0% +configuration of the pendulum here so + + + align:start position:0% +configuration of the pendulum here so +you know these sorts of problems already + + align:start position:0% +you know these sorts of problems already + + + align:start position:0% +you know these sorts of problems already +but we talked about this one right + + align:start position:0% +but we talked about this one right + + + align:start position:0% +but we talked about this one right +linear sorts of programs these are + + align:start position:0% +linear sorts of programs these are + + + align:start position:0% +linear sorts of programs these are +optimization problems where the + + align:start position:0% +optimization problems where the + + + align:start position:0% +optimization problems where the +objective function is linear in the + + align:start position:0% +objective function is linear in the + + + align:start position:0% +objective function is linear in the +design variables right so it's just the + + align:start position:0% +design variables right so it's just the + + + align:start position:0% +design variables right so it's just the +dot product between X and some vector C + + align:start position:0% +dot product between X and some vector C + + + align:start position:0% +dot product between X and some vector C +that weights the different design + + align:start position:0% +that weights the different design + + + align:start position:0% +that weights the different design +options against each other so we talked + + align:start position:0% +options against each other so we talked + + + align:start position:0% +options against each other so we talked +about ice cream guess this is all + + align:start position:0% +about ice cream guess this is all + + + align:start position:0% +about ice cream guess this is all +premium ice cream + + align:start position:0% +premium ice cream + + + align:start position:0% +premium ice cream +it comes in the small containers right + + align:start position:0% +it comes in the small containers right + + + align:start position:0% +it comes in the small containers right +subject to different constraints so + + align:start position:0% +subject to different constraints so + + + align:start position:0% +subject to different constraints so +those constraints can be things like oh + + align:start position:0% +those constraints can be things like oh + + + align:start position:0% +those constraints can be things like oh +x2 be positive because we can't make + + align:start position:0% +x2 be positive because we can't make + + + align:start position:0% +x2 be positive because we can't make +negative amounts of ice-cream and maybe + + align:start position:0% +negative amounts of ice-cream and maybe + + + align:start position:0% +negative amounts of ice-cream and maybe +we've done market research that tells us + + align:start position:0% +we've done market research that tells us + + + align:start position:0% +we've done market research that tells us +that the market can only tolerate + + align:start position:0% +that the market can only tolerate + + + align:start position:0% +that the market can only tolerate +certain ratios of different types of + + align:start position:0% +certain ratios of different types of + + + align:start position:0% +certain ratios of different types of +ice-cream and that maybe some set of + + align:start position:0% +ice-cream and that maybe some set of + + + align:start position:0% +ice-cream and that maybe some set of +linear equations that describe that + + align:start position:0% +linear equations that describe that + + + align:start position:0% +linear equations that describe that +market research that sort of bound the + + align:start position:0% +market research that sort of bound the + + + align:start position:0% +market research that sort of bound the +upper values of how much ice cream we + + align:start position:0% +upper values of how much ice cream we + + + align:start position:0% +upper values of how much ice cream we +can put out on the market then we try to + + align:start position:0% +can put out on the market then we try to + + + align:start position:0% +can put out on the market then we try to +choose the optimal blend of you know + + align:start position:0% +choose the optimal blend of you know + + + align:start position:0% +choose the optimal blend of you know +pina colada and strawberry - so okay + + align:start position:0% +pina colada and strawberry - so okay + + + align:start position:0% +pina colada and strawberry - so okay +those are linear programs okay this is + + align:start position:0% +those are linear programs okay this is + + + align:start position:0% +those are linear programs okay this is +an unqualified say minimize f of X + + align:start position:0% +an unqualified say minimize f of X + + + align:start position:0% +an unqualified say minimize f of X +subject to the constraint that C of X is + + align:start position:0% +subject to the constraint that C of X is + + + align:start position:0% +subject to the constraint that C of X is +0 and H of X is positive right so + + align:start position:0% +0 and H of X is positive right so + + + align:start position:0% +0 and H of X is positive right so +minimize it over the values of X that + + align:start position:0% +minimize it over the values of X that + + + align:start position:0% +minimize it over the values of X that +satisfy these two constraints + + align:start position:0% +satisfy these two constraints + + + align:start position:0% +satisfy these two constraints +there's an old approach discussed in the + + align:start position:0% +there's an old approach discussed in the + + + align:start position:0% +there's an old approach discussed in the +literature and it's not used I'm going + + align:start position:0% +literature and it's not used I'm going + + + align:start position:0% +literature and it's not used I'm going +to describe it to you and then I want + + align:start position:0% +to describe it to you and then I want + + + align:start position:0% +to describe it to you and then I want +you to try to figure out why it's not + + align:start position:0% +you to try to figure out why it's not + + + align:start position:0% +you to try to figure out why it's not +used okay and it's called the penalty + + align:start position:0% +used okay and it's called the penalty + + + align:start position:0% +used okay and it's called the penalty +method and the penalty method works this + + align:start position:0% +method and the penalty method works this + + + align:start position:0% +method and the penalty method works this +way + + align:start position:0% +way + + + align:start position:0% +way +it says define a new objective function + + align:start position:0% +it says define a new objective function + + + align:start position:0% +it says define a new objective function +which is our old objective function plus + + align:start position:0% +which is our old objective function plus + + + align:start position:0% +which is our old objective function plus +some penalty for violating the + + align:start position:0% +some penalty for violating the + + + align:start position:0% +some penalty for violating the +constraints how does that penalty work + + align:start position:0% +constraints how does that penalty work + + + align:start position:0% +constraints how does that penalty work +so we know that we want values of X for + + align:start position:0% +so we know that we want values of X for + + + align:start position:0% +so we know that we want values of X for +which C of X is equal to 0 so if we add + + align:start position:0% +which C of X is equal to 0 so if we add + + + align:start position:0% +which C of X is equal to 0 so if we add +to our objective function the norm of C + + align:start position:0% +to our objective function the norm of C + + + align:start position:0% +to our objective function the norm of C +of X this is a positive quantity this is + + align:start position:0% +of X this is a positive quantity this is + + + align:start position:0% +of X this is a positive quantity this is +a positive quantity whenever X doesn't + + align:start position:0% +a positive quantity whenever X doesn't + + + align:start position:0% +a positive quantity whenever X doesn't +satisfy the constraint this positive + + align:start position:0% +satisfy the constraint this positive + + + align:start position:0% +satisfy the constraint this positive +quantity will be will give us a bigger + + align:start position:0% +quantity will be will give us a bigger + + + align:start position:0% +quantity will be will give us a bigger +value for this objective function f + + align:start position:0% +value for this objective function f + + + align:start position:0% +value for this objective function f +right then if C of X was equal to 0 so + + align:start position:0% +right then if C of X was equal to 0 so + + + align:start position:0% +right then if C of X was equal to 0 so +we penalize write points which don't + + align:start position:0% +we penalize write points which don't + + + align:start position:0% +we penalize write points which don't +satisfy the constraint and in the limit + + align:start position:0% +satisfy the constraint and in the limit + + + align:start position:0% +satisfy the constraint and in the limit +that this penalty factor mu here goes to + + align:start position:0% +that this penalty factor mu here goes to + + + align:start position:0% +that this penalty factor mu here goes to +0 the penalties get large okay so large + + align:start position:0% +0 the penalties get large okay so large + + + align:start position:0% +0 the penalties get large okay so large +that our solution will have to prefer + + align:start position:0% +that our solution will have to prefer + + + align:start position:0% +that our solution will have to prefer +right satisfying the constraints there's + + align:start position:0% +right satisfying the constraints there's + + + align:start position:0% +right satisfying the constraints there's +another penalty factor over here which + + align:start position:0% +another penalty factor over here which + + + align:start position:0% +another penalty factor over here which +is identical to this one but for the + + align:start position:0% +is identical to this one but for the + + + align:start position:0% +is identical to this one but for the +inequality constraint it's + + align:start position:0% +inequality constraint it's + + + align:start position:0% +inequality constraint it's +it says take a Heaviside step function + + align:start position:0% +it says take a Heaviside step function + + + align:start position:0% +it says take a Heaviside step function +right 4 which is equal to 1 right when + + align:start position:0% +right 4 which is equal to 1 right when + + + align:start position:0% +right 4 which is equal to 1 right when +the value of its argument is positive + + align:start position:0% +the value of its argument is positive + + + align:start position:0% +the value of its argument is positive +and it's equal to 0 when the value of + + align:start position:0% +and it's equal to 0 when the value of + + + align:start position:0% +and it's equal to 0 when the value of +its argument is negative right so + + align:start position:0% +its argument is negative right so + + + align:start position:0% +its argument is negative right so +whenever I violate my each of my + + align:start position:0% +whenever I violate my each of my + + + align:start position:0% +whenever I violate my each of my +inequality constraints H I of X right + + align:start position:0% +inequality constraints H I of X right + + + align:start position:0% +inequality constraints H I of X right +turn on this have a side step function + + align:start position:0% +turn on this have a side step function + + + align:start position:0% +turn on this have a side step function +make it equal to 1 and then multiply it + + align:start position:0% +make it equal to 1 and then multiply it + + + align:start position:0% +make it equal to 1 and then multiply it +by the value of the constraint squared a + + align:start position:0% +by the value of the constraint squared a + + + align:start position:0% +by the value of the constraint squared a +positive number right so this is the + + align:start position:0% +positive number right so this is the + + + align:start position:0% +positive number right so this is the +inequality constraint penalty and this + + align:start position:0% +inequality constraint penalty and this + + + align:start position:0% +inequality constraint penalty and this +is the Equality constraint penalty + + align:start position:0% +is the Equality constraint penalty + + + align:start position:0% +is the Equality constraint penalty +people don't use this though it makes + + align:start position:0% +people don't use this though it makes + + + align:start position:0% +people don't use this though it makes +sense right I take the limit that mu + + align:start position:0% +sense right I take the limit that mu + + + align:start position:0% +sense right I take the limit that mu +goes to 0 I'm gonna have to prefer + + align:start position:0% +goes to 0 I'm gonna have to prefer + + + align:start position:0% +goes to 0 I'm gonna have to prefer +solutions right that satisfy these + + align:start position:0% +solutions right that satisfy these + + + align:start position:0% +solutions right that satisfy these +constraints otherwise right if I don't + + align:start position:0% +constraints otherwise right if I don't + + + align:start position:0% +constraints otherwise right if I don't +satisfy these constraints I can always + + align:start position:0% +satisfy these constraints I can always + + + align:start position:0% +satisfy these constraints I can always +move closer to a solution that satisfies + + align:start position:0% +move closer to a solution that satisfies + + + align:start position:0% +move closer to a solution that satisfies +the constraint and I'll bring down right + + align:start position:0% +the constraint and I'll bring down right + + + align:start position:0% +the constraint and I'll bring down right +the value of this objective function + + align:start position:0% +the value of this objective function + + + align:start position:0% +the value of this objective function +I'll make it lower so I'll always prefer + + align:start position:0% +I'll make it lower so I'll always prefer + + + align:start position:0% +I'll make it lower so I'll always prefer +these lower value solutions but can you + + align:start position:0% +these lower value solutions but can you + + + align:start position:0% +these lower value solutions but can you +guys take a second and sort of talk to + + align:start position:0% +guys take a second and sort of talk to + + + align:start position:0% +guys take a second and sort of talk to +each other see if you can figure out why + + align:start position:0% +each other see if you can figure out why + + + align:start position:0% +each other see if you can figure out why +why one doesn't use this method why is + + align:start position:0% +why one doesn't use this method why is + + + align:start position:0% +why one doesn't use this method why is +this method a problem + + align:start position:0% + + + + align:start position:0% + +okay I heard I heard the volume go up at + + align:start position:0% +okay I heard I heard the volume go up at + + + align:start position:0% +okay I heard I heard the volume go up at +some point which means either you switch + + align:start position:0% +some point which means either you switch + + + align:start position:0% +some point which means either you switch +topics and thought we're comfortable + + align:start position:0% +topics and thought we're comfortable + + + align:start position:0% +topics and thought we're comfortable +talking about that than this or maybe + + align:start position:0% +talking about that than this or maybe + + + align:start position:0% +talking about that than this or maybe +maybe you guys were coming to some + + align:start position:0% +maybe you guys were coming to some + + + align:start position:0% +maybe you guys were coming to some +conclusions or had some ideas about why + + align:start position:0% +conclusions or had some ideas about why + + + align:start position:0% +conclusions or had some ideas about why +this this might be a bad idea you want + + align:start position:0% +this this might be a bad idea you want + + + align:start position:0% +this this might be a bad idea you want +to join a volunteer some of what you + + align:start position:0% +to join a volunteer some of what you + + + align:start position:0% +to join a volunteer some of what you +were talking about yeah well that's that + + align:start position:0% +were talking about yeah well that's that + + + align:start position:0% +were talking about yeah well that's that +that's an interesting idea so yeah so if + + align:start position:0% +that's an interesting idea so yeah so if + + + align:start position:0% +that's an interesting idea so yeah so if +we have a non-convex optimization + + align:start position:0% +we have a non-convex optimization + + + align:start position:0% +we have a non-convex optimization +problem there could be some issues with + + align:start position:0% +problem there could be some issues with + + + align:start position:0% +problem there could be some issues with +f of X and maybe f of X runs away so + + align:start position:0% +f of X and maybe f of X runs away so + + + align:start position:0% +f of X and maybe f of X runs away so +fast that I can never make the penalty + + align:start position:0% +fast that I can never make the penalty + + + align:start position:0% +fast that I can never make the penalty +big enough to enforce the constraint + + align:start position:0% +big enough to enforce the constraint + + + align:start position:0% +big enough to enforce the constraint +that's that's actually a really + + align:start position:0% +that's that's actually a really + + + align:start position:0% +that's that's actually a really +interesting idea and I like I like the + + align:start position:0% +interesting idea and I like I like the + + + align:start position:0% +interesting idea and I like I like the +idea of comparing the magnitude of these + + align:start position:0% +idea of comparing the magnitude of these + + + align:start position:0% +idea of comparing the magnitude of these +two terms I think that's on the right + + align:start position:0% +two terms I think that's on the right + + + align:start position:0% +two terms I think that's on the right +track where there were there's some + + align:start position:0% +track where there were there's some + + + align:start position:0% +track where there were there's some +other ideas about why why you might not + + align:start position:0% +other ideas about why why you might not + + + align:start position:0% +other ideas about why why you might not +do this different ideas yeah well you + + align:start position:0% +do this different ideas yeah well you + + + align:start position:0% +do this different ideas yeah well you +know that that's an interesting idea + + align:start position:0% +know that that's an interesting idea + + + align:start position:0% +know that that's an interesting idea +but actually the two terms in the + + align:start position:0% +but actually the two terms in the + + + align:start position:0% +but actually the two terms in the +parentheses here are both positive right + + align:start position:0% +parentheses here are both positive right + + + align:start position:0% +parentheses here are both positive right +so they're only going to be minimized + + align:start position:0% +so they're only going to be minimized + + + align:start position:0% +so they're only going to be minimized +when I satisfy the constraints right so + + align:start position:0% +when I satisfy the constraints right so + + + align:start position:0% +when I satisfy the constraints right so +the local minimum of the of the terms in + + align:start position:0% +the local minimum of the of the terms in + + + align:start position:0% +the local minimum of the of the terms in +parentheses sit on the on or within the + + align:start position:0% +parentheses sit on the on or within the + + + align:start position:0% +parentheses sit on the on or within the +boundaries of the feasible set that + + align:start position:0% +boundaries of the feasible set that + + + align:start position:0% +boundaries of the feasible set that +we're looking at so by construction + + align:start position:0% +we're looking at so by construction + + + align:start position:0% +we're looking at so by construction +actually we're going to be able to + + align:start position:0% +actually we're going to be able to + + + align:start position:0% +actually we're going to be able to +satisfy them because the local minimum + + align:start position:0% +satisfy them because the local minimum + + + align:start position:0% +satisfy them because the local minimum +of these points that sits on these on + + align:start position:0% +of these points that sits on these on + + + align:start position:0% +of these points that sits on these on +these boundaries these terms are + + align:start position:0% +these boundaries these terms are + + + align:start position:0% +these boundaries these terms are +minimized okay by satisfying the + + align:start position:0% +minimized okay by satisfying the + + + align:start position:0% +minimized okay by satisfying the +constraints other ideas yeah what's that + + align:start position:0% +constraints other ideas yeah what's that + + + align:start position:0% +constraints other ideas yeah what's that +oh this is a good point right the + + align:start position:0% +oh this is a good point right the + + + align:start position:0% +oh this is a good point right the +iterates like this is an unconstrained + + align:start position:0% +iterates like this is an unconstrained + + + align:start position:0% +iterates like this is an unconstrained +optimization problem I'm just going to + + align:start position:0% +optimization problem I'm just going to + + + align:start position:0% +optimization problem I'm just going to +minimize this objective function it's + + align:start position:0% +minimize this objective function it's + + + align:start position:0% +minimize this objective function it's +like what her said right I can go + + align:start position:0% +like what her said right I can go + + + align:start position:0% +like what her said right I can go +anywhere I want in the domain I'm gonna + + align:start position:0% +anywhere I want in the domain I'm gonna + + + align:start position:0% +anywhere I want in the domain I'm gonna +minimize this objective function I'm + + align:start position:0% +minimize this objective function I'm + + + align:start position:0% +minimize this objective function I'm +gonna try and take the limit as mu goes + + align:start position:0% +gonna try and take the limit as mu goes + + + align:start position:0% +gonna try and take the limit as mu goes +to zero the interests don't have to be + + align:start position:0% +to zero the interests don't have to be + + + align:start position:0% +to zero the interests don't have to be +feasible maybe I can't even evaluate f + + align:start position:0% +feasible maybe I can't even evaluate f + + + align:start position:0% +feasible maybe I can't even evaluate f +of X if + + align:start position:0% +of X if + + + align:start position:0% +of X if +it's aren't feasible that's an excellent + + align:start position:0% +it's aren't feasible that's an excellent + + + align:start position:0% +it's aren't feasible that's an excellent +point right that could be an issue + + align:start position:0% +point right that could be an issue + + + align:start position:0% +point right that could be an issue +anything else there's some other ideas + + align:start position:0% +anything else there's some other ideas + + + align:start position:0% +anything else there's some other ideas +sure I think I think that's a good point + + align:start position:0% + + + + align:start position:0% + +short so you'll you'll see actually the + + align:start position:0% +short so you'll you'll see actually the + + + align:start position:0% +short so you'll you'll see actually the +way the right way to do this is to use + + align:start position:0% +way the right way to do this is to use + + + align:start position:0% +way the right way to do this is to use +what's called interior point methods + + align:start position:0% +what's called interior point methods + + + align:start position:0% +what's called interior point methods +which laid the inside the domain this is + + align:start position:0% +which laid the inside the domain this is + + + align:start position:0% +which laid the inside the domain this is +an excellent point there's another issue + + align:start position:0% +an excellent point there's another issue + + + align:start position:0% +an excellent point there's another issue +with this that's it's I think it's + + align:start position:0% +with this that's it's I think it's + + + align:start position:0% +with this that's it's I think it's +actually less subtle than some of these + + align:start position:0% +actually less subtle than some of these + + + align:start position:0% +actually less subtle than some of these +ideas which are all they're all correct + + align:start position:0% +ideas which are all they're all correct + + + align:start position:0% +ideas which are all they're all correct +actually these can be problems with this + + align:start position:0% +actually these can be problems with this + + + align:start position:0% +actually these can be problems with this +sort of penalty method as I take the + + align:start position:0% +sort of penalty method as I take the + + + align:start position:0% +sort of penalty method as I take the +limit that nu goes to zero the penalty + + align:start position:0% +limit that nu goes to zero the penalty + + + align:start position:0% +limit that nu goes to zero the penalty +function becomes large okay for all + + align:start position:0% +function becomes large okay for all + + + align:start position:0% +function becomes large okay for all +points outside the domain they can + + align:start position:0% +points outside the domain they can + + + align:start position:0% +points outside the domain they can +become larger than F right for those + + align:start position:0% +become larger than F right for those + + + align:start position:0% +become larger than F right for those +points and so there's some practical + + align:start position:0% +points and so there's some practical + + + align:start position:0% +points and so there's some practical +issues about comparing these two terms + + align:start position:0% +issues about comparing these two terms + + + align:start position:0% +issues about comparing these two terms +against each other right I may not have + + align:start position:0% +against each other right I may not have + + + align:start position:0% +against each other right I may not have +sufficient accuracy sufficient number of + + align:start position:0% +sufficient accuracy sufficient number of + + + align:start position:0% +sufficient accuracy sufficient number of +digits to accurately add these two terms + + align:start position:0% +digits to accurately add these two terms + + + align:start position:0% +digits to accurately add these two terms +together so I may prefer to find some + + align:start position:0% +together so I may prefer to find some + + + align:start position:0% +together so I may prefer to find some +point right that lives on the boundary + + align:start position:0% +point right that lives on the boundary + + + align:start position:0% +point right that lives on the boundary +of the domain as mu goes to zero but I + + align:start position:0% +of the domain as mu goes to zero but I + + + align:start position:0% +of the domain as mu goes to zero but I +can't guarantee you that it was a minima + + align:start position:0% +can't guarantee you that it was a minima + + + align:start position:0% +can't guarantee you that it was a minima +of F on that domain okay or within that + + align:start position:0% +of F on that domain okay or within that + + + align:start position:0% +of F on that domain okay or within that +feasible set so a lot of practical + + align:start position:0% +feasible set so a lot of practical + + + align:start position:0% +feasible set so a lot of practical +issues that suggest this is a bad idea + + align:start position:0% +issues that suggest this is a bad idea + + + align:start position:0% +issues that suggest this is a bad idea +this is an old idea people knew this was + + align:start position:0% +this is an old idea people knew this was + + + align:start position:0% +this is an old idea people knew this was +bad for a long time it seems natural + + align:start position:0% +bad for a long time it seems natural + + + align:start position:0% +bad for a long time it seems natural +though it seems like a good way to + + align:start position:0% +though it seems like a good way to + + + align:start position:0% +though it seems like a good way to +transform from these constrained + + align:start position:0% +transform from these constrained + + + align:start position:0% +transform from these constrained +optimization problems to something we + + align:start position:0% +optimization problems to something we + + + align:start position:0% +optimization problems to something we +know how to solve an unconstrained + + align:start position:0% +know how to solve an unconstrained + + + align:start position:0% +know how to solve an unconstrained +optimization problem but actually it + + align:start position:0% +optimization problem but actually it + + + align:start position:0% +optimization problem but actually it +turns out not to be such a great way to + + align:start position:0% +turns out not to be such a great way to + + + align:start position:0% +turns out not to be such a great way to +do it okay so let's talk about + + align:start position:0% +do it okay so let's talk about + + + align:start position:0% +do it okay so let's talk about +separating out these two different + + align:start position:0% +separating out these two different + + + align:start position:0% +separating out these two different +methods from each other where these two + + align:start position:0% +methods from each other where these two + + + align:start position:0% +methods from each other where these two +different two different problems let's + + align:start position:0% +different two different problems let's + + + align:start position:0% +different two different problems let's +talk first about equality constraints + + align:start position:0% +talk first about equality constraints + + + align:start position:0% +talk first about equality constraints +and then we'll talk about inequality + + align:start position:0% +and then we'll talk about inequality + + + align:start position:0% +and then we'll talk about inequality +constraints so a quality constrained + + align:start position:0% +constraints so a quality constrained + + + align:start position:0% +constraints so a quality constrained +optimization problems look like this + + align:start position:0% +optimization problems look like this + + + align:start position:0% +optimization problems look like this +right minimize f of X subject to C of x + + align:start position:0% +right minimize f of X subject to C of x + + + align:start position:0% +right minimize f of X subject to C of x +equals zero and let's make it even + + align:start position:0% +equals zero and let's make it even + + + align:start position:0% +equals zero and let's make it even +easier let's rather than having some + + align:start position:0% +easier let's rather than having some + + + align:start position:0% +easier let's rather than having some +vector of equality constraints let's + + align:start position:0% +vector of equality constraints let's + + + align:start position:0% +vector of equality constraints let's +just have a single equation that we have + + align:start position:0% +just have a single equation that we have + + + align:start position:0% +just have a single equation that we have +to satisfy for that equality constraint + + align:start position:0% +to satisfy for that equality constraint + + + align:start position:0% +to satisfy for that equality constraint +like the equation for a circle right + + align:start position:0% +like the equation for a circle right + + + align:start position:0% +like the equation for a circle right +solutions have to sit on the + + align:start position:0% +solutions have to sit on the + + + align:start position:0% +solutions have to sit on the +circumference of a circle okay so one + + align:start position:0% +circumference of a circle okay so one + + + align:start position:0% +circumference of a circle okay so one +equation that we have to satisfy you + + align:start position:0% +equation that we have to satisfy you + + + align:start position:0% +equation that we have to satisfy you +might ask again what are the necessary + + align:start position:0% +might ask again what are the necessary + + + align:start position:0% +might ask again what are the necessary +conditions for defining a minimum that's + + align:start position:0% +conditions for defining a minimum that's + + + align:start position:0% +conditions for defining a minimum that's +what we use when we had a quality or + + align:start position:0% +what we use when we had a quality or + + + align:start position:0% +what we use when we had a quality or +when we had unconstrained optimization + + align:start position:0% +when we had unconstrained optimization + + + align:start position:0% +when we had unconstrained optimization +first we had to define what what a + + align:start position:0% +first we had to define what what a + + + align:start position:0% +first we had to define what what a +minimum was right and we found that + + align:start position:0% +minimum was right and we found that + + + align:start position:0% +minimum was right and we found that +minima were critical points places were + + align:start position:0% +minima were critical points places were + + + align:start position:0% +minima were critical points places were +the gradient of the objective function + + align:start position:0% +the gradient of the objective function + + + align:start position:0% +the gradient of the objective function +worse was zero okay that doesn't have to + + align:start position:0% +worse was zero okay that doesn't have to + + + align:start position:0% +worse was zero okay that doesn't have to +be true anymore right now the minima has + + align:start position:0% +be true anymore right now the minima has + + + align:start position:0% +be true anymore right now the minima has +to live on this boundary right of some + + align:start position:0% +to live on this boundary right of some + + + align:start position:0% +to live on this boundary right of some +domain has to live in this set of points + + align:start position:0% +domain has to live in this set of points + + + align:start position:0% +domain has to live in this set of points +e of x equals zero and the gradient of F + + align:start position:0% +e of x equals zero and the gradient of F + + + align:start position:0% +e of x equals zero and the gradient of F +is not necessarily zero at that minimal + + align:start position:0% +is not necessarily zero at that minimal + + + align:start position:0% +is not necessarily zero at that minimal +point but you might guess right the + + align:start position:0% +point but you might guess right the + + + align:start position:0% +point but you might guess right the +Taylor expansions are the way to figure + + align:start position:0% +Taylor expansions are the way to figure + + + align:start position:0% +Taylor expansions are the way to figure +out okay Taylor expansions are the way + + align:start position:0% +out okay Taylor expansions are the way + + + align:start position:0% +out okay Taylor expansions are the way +to figure out the way to figure out what + + align:start position:0% +to figure out the way to figure out what + + + align:start position:0% +to figure out the way to figure out what +the appropriate conditions for a minima + + align:start position:0% +the appropriate conditions for a minima + + + align:start position:0% +the appropriate conditions for a minima +are so let's take f of X and let's + + align:start position:0% +are so let's take f of X and let's + + + align:start position:0% +are so let's take f of X and let's +expand it do a Taylor expansion in some + + align:start position:0% +expand it do a Taylor expansion in some + + + align:start position:0% +expand it do a Taylor expansion in some +direction D okay so we'll take a step + + align:start position:0% +direction D okay so we'll take a step + + + align:start position:0% +direction D okay so we'll take a step +away from X which is small in some + + align:start position:0% +away from X which is small in some + + + align:start position:0% +away from X which is small in some +direction D so f of X plus D is f of X + + align:start position:0% +direction D so f of X plus D is f of X + + + align:start position:0% +direction D so f of X plus D is f of X +plus G dot d all right the dot product + + align:start position:0% +plus G dot d all right the dot product + + + align:start position:0% +plus G dot d all right the dot product +between the gradient of F and D and at a + + align:start position:0% +between the gradient of F and D and at a + + + align:start position:0% +between the gradient of F and D and at a +minimum right either + + align:start position:0% +minimum right either + + + align:start position:0% +minimum right either +the gradient is 0 or the gradient is + + align:start position:0% +the gradient is 0 or the gradient is + + + align:start position:0% +the gradient is 0 or the gradient is +perpendicular to this direction we moved + + align:start position:0% +perpendicular to this direction we moved + + + align:start position:0% +perpendicular to this direction we moved +in D okay we know that because this term + + align:start position:0% +in D okay we know that because this term + + + align:start position:0% +in D okay we know that because this term +right this term is going to increase + + align:start position:0% +right this term is going to increase + + + align:start position:0% +right this term is going to increase +will change the value of f of X it'll + + align:start position:0% +will change the value of f of X it'll + + + align:start position:0% +will change the value of f of X it'll +either make it bigger or smaller + + align:start position:0% +either make it bigger or smaller + + + align:start position:0% +either make it bigger or smaller +depending on whether it's positive or + + align:start position:0% +depending on whether it's positive or + + + align:start position:0% +depending on whether it's positive or +negative + + align:start position:0% +negative + + + align:start position:0% +negative +in either case it'll say that this point + + align:start position:0% +in either case it'll say that this point + + + align:start position:0% +in either case it'll say that this point +X can't be a minimum right unless this + + align:start position:0% +X can't be a minimum right unless this + + + align:start position:0% +X can't be a minimum right unless this +term is exactly equal to 0 in the limit + + align:start position:0% +term is exactly equal to 0 in the limit + + + align:start position:0% +term is exactly equal to 0 in the limit +that D becomes small so either the + + align:start position:0% +that D becomes small so either the + + + align:start position:0% +that D becomes small so either the +gradient is 0 or the gradient is + + align:start position:0% +gradient is 0 or the gradient is + + + align:start position:0% +gradient is 0 or the gradient is +orthogonal to this direction D we + + align:start position:0% +orthogonal to this direction D we + + + align:start position:0% +orthogonal to this direction D we +stepped in and D was arbitrary right we + + align:start position:0% +stepped in and D was arbitrary right we + + + align:start position:0% +stepped in and D was arbitrary right we +just said take a step in a direction D + + align:start position:0% + + + + align:start position:0% + +let's take our equality constraint and + + align:start position:0% +let's take our equality constraint and + + + align:start position:0% +let's take our equality constraint and +do the sort of the same sort of Taylor + + align:start position:0% +do the sort of the same sort of Taylor + + + align:start position:0% +do the sort of the same sort of Taylor +expansion okay because we know right if + + align:start position:0% +expansion okay because we know right if + + + align:start position:0% +expansion okay because we know right if +we're searching for a minima along this + + align:start position:0% +we're searching for a minima along this + + + align:start position:0% +we're searching for a minima along this +curve + + align:start position:0% +curve + + + align:start position:0% +curve +see of X better be equal to zero it + + align:start position:0% +see of X better be equal to zero it + + + align:start position:0% +see of X better be equal to zero it +better satisfy the constraint and also + + align:start position:0% +better satisfy the constraint and also + + + align:start position:0% +better satisfy the constraint and also +see of X plus D right that little step + + align:start position:0% +see of X plus D right that little step + + + align:start position:0% +see of X plus D right that little step +in the direction D should also satisfy + + align:start position:0% +in the direction D should also satisfy + + + align:start position:0% +in the direction D should also satisfy +the constraint right we want to study + + align:start position:0% +the constraint right we want to study + + + align:start position:0% +the constraint right we want to study +only the feasible set of values so + + align:start position:0% +only the feasible set of values so + + + align:start position:0% +only the feasible set of values so +actually D wasn't arbitrary D had to + + align:start position:0% +actually D wasn't arbitrary D had to + + + align:start position:0% +actually D wasn't arbitrary D had to +satisfy this constraint then when I took + + align:start position:0% +satisfy this constraint then when I took + + + align:start position:0% +satisfy this constraint then when I took +this little step C of X plus D had to be + + align:start position:0% +this little step C of X plus D had to be + + + align:start position:0% +this little step C of X plus D had to be +equal to zero so again we'll take it now + + align:start position:0% +equal to zero so again we'll take it now + + + align:start position:0% +equal to zero so again we'll take it now +a Taylor expansion of C of X plus D + + align:start position:0% +a Taylor expansion of C of X plus D + + + align:start position:0% +a Taylor expansion of C of X plus D +which is C of X plus grad of C of X + + align:start position:0% +which is C of X plus grad of C of X + + + align:start position:0% +which is C of X plus grad of C of X +dotted with D okay and that implies + + align:start position:0% +dotted with D okay and that implies + + + align:start position:0% +dotted with D okay and that implies +write the D must be perpendicular to the + + align:start position:0% +write the D must be perpendicular to the + + + align:start position:0% +write the D must be perpendicular to the +gradient of C of X ok because C of X + + align:start position:0% +gradient of C of X ok because C of X + + + align:start position:0% +gradient of C of X ok because C of X +plus D has to be 0 and C of X has to be + + align:start position:0% +plus D has to be 0 and C of X has to be + + + align:start position:0% +plus D has to be 0 and C of X has to be +0 so the gradient of C of X dot d to + + align:start position:0% +0 so the gradient of C of X dot d to + + + align:start position:0% +0 so the gradient of C of X dot d to +leading order right has also got to be + + align:start position:0% +leading order right has also got to be + + + align:start position:0% +leading order right has also got to be +equal to 0 so D and the gradient in C + + align:start position:0% +equal to 0 so D and the gradient in C + + + align:start position:0% +equal to 0 so D and the gradient in C +are perpendicular and D and the gradient + + align:start position:0% +are perpendicular and D and the gradient + + + align:start position:0% +are perpendicular and D and the gradient +in G have to be perpendicular at a + + align:start position:0% +in G have to be perpendicular at a + + + align:start position:0% +in G have to be perpendicular at a +minimum that's going to define the + + align:start position:0% +minimum that's going to define the + + + align:start position:0% +minimum that's going to define the +minimum on this equality constraint set + + align:start position:0% +minimum on this equality constraint set + + + align:start position:0% +minimum on this equality constraint set +that makes sense right C's satisfies the + + align:start position:0% +that makes sense right C's satisfies the + + + align:start position:0% +that makes sense right C's satisfies the +constraint C plus D satisfies the + + align:start position:0% +constraint C plus D satisfies the + + + align:start position:0% +constraint C plus D satisfies the +constraint if this is true D has to be + + align:start position:0% +constraint if this is true D has to be + + + align:start position:0% +constraint if this is true D has to be +perpendicular to the gradient of C G has + + align:start position:0% +perpendicular to the gradient of C G has + + + align:start position:0% +perpendicular to the gradient of C G has +to be perpendicular to the gradient of D + + align:start position:0% +to be perpendicular to the gradient of D + + + align:start position:0% +to be perpendicular to the gradient of D +D is in some sense arbitrary still okay + + align:start position:0% +D is in some sense arbitrary still okay + + + align:start position:0% +D is in some sense arbitrary still okay +D has to satisfy condition that it's + + align:start position:0% +D has to satisfy condition that it's + + + align:start position:0% +D has to satisfy condition that it's +perpendicular to the gradient of C but + + align:start position:0% +perpendicular to the gradient of C but + + + align:start position:0% +perpendicular to the gradient of C but +who knows right there could be lots of + + align:start position:0% +who knows right there could be lots of + + + align:start position:0% +who knows right there could be lots of +vectors that are perpendicular to the + + align:start position:0% +vectors that are perpendicular to the + + + align:start position:0% +vectors that are perpendicular to the +gradient of C so the only generic + + align:start position:0% +gradient of C so the only generic + + + align:start position:0% +gradient of C so the only generic +relationship between these two we can + + align:start position:0% +relationship between these two we can + + + align:start position:0% +relationship between these two we can +formulate is G must be parallel to the + + align:start position:0% +formulate is G must be parallel to the + + + align:start position:0% +formulate is G must be parallel to the +gradient of C G's perpendicular to the + + align:start position:0% +gradient of C G's perpendicular to the + + + align:start position:0% +gradient of C G's perpendicular to the +gradient of C is perpendicular to be in + + align:start position:0% +gradient of C is perpendicular to be in + + + align:start position:0% +gradient of C is perpendicular to be in +the most generic way G and gradient of C + + align:start position:0% +the most generic way G and gradient of C + + + align:start position:0% +the most generic way G and gradient of C +should be parallel to each other because + + align:start position:0% +should be parallel to each other because + + + align:start position:0% +should be parallel to each other because +D I can select arbitrarily from all the + + align:start position:0% +D I can select arbitrarily from all the + + + align:start position:0% +D I can select arbitrarily from all the +vectors in of the same dimension as X ok + + align:start position:0% +vectors in of the same dimension as X ok + + + align:start position:0% +vectors in of the same dimension as X ok +if G is parallel to the gradient of C + + align:start position:0% +if G is parallel to the gradient of C + + + align:start position:0% +if G is parallel to the gradient of C +then I can write that G - write some + + align:start position:0% +then I can write that G - write some + + + align:start position:0% +then I can write that G - write some +scalar multiplied by the gradient of C + + align:start position:0% +scalar multiplied by the gradient of C + + + align:start position:0% +scalar multiplied by the gradient of C +is equal to 0 that's an equivalent + + align:start position:0% +is equal to 0 that's an equivalent + + + align:start position:0% +is equal to 0 that's an equivalent +statement that G is parallel to the + + align:start position:0% +statement that G is parallel to the + + + align:start position:0% +statement that G is parallel to the +gradient of C so that's a condition + + align:start position:0% +gradient of C so that's a condition + + + align:start position:0% +gradient of C so that's a condition +associated with points X that solve this + + align:start position:0% +associated with points X that solve this + + + align:start position:0% +associated with points X that solve this +equality constrained problem the other + + align:start position:0% +equality constrained problem the other + + + align:start position:0% +equality constrained problem the other +condition is that point + + align:start position:0% +condition is that point + + + align:start position:0% +condition is that point +sell us to satisfy the Equality + + align:start position:0% +sell us to satisfy the Equality + + + align:start position:0% +sell us to satisfy the Equality +constraint right but I introduced a new + + align:start position:0% +constraint right but I introduced a new + + + align:start position:0% +constraint right but I introduced a new +unknown this lambda which is called the + + align:start position:0% +unknown this lambda which is called the + + + align:start position:0% +unknown this lambda which is called the +Lagrange multiplier okay so I know I + + align:start position:0% +Lagrange multiplier okay so I know I + + + align:start position:0% +Lagrange multiplier okay so I know I +have one extra unknown but I have one + + align:start position:0% +have one extra unknown but I have one + + + align:start position:0% +have one extra unknown but I have one +extra equation let me give you a + + align:start position:0% +extra equation let me give you a + + + align:start position:0% +extra equation let me give you a +graphical depiction of this and then + + align:start position:0% +graphical depiction of this and then + + + align:start position:0% +graphical depiction of this and then +I'll write down the the formal equations + + align:start position:0% +I'll write down the the formal equations + + + align:start position:0% +I'll write down the the formal equations +again so let's suppose we want to + + align:start position:0% +again so let's suppose we want to + + + align:start position:0% +again so let's suppose we want to +minimize write this parabolic function + + align:start position:0% +minimize write this parabolic function + + + align:start position:0% +minimize write this parabolic function +subject to the constraint that the + + align:start position:0% +subject to the constraint that the + + + align:start position:0% +subject to the constraint that the +solution lives on the line okay so + + align:start position:0% +solution lives on the line okay so + + + align:start position:0% +solution lives on the line okay so +here's the contours of the function and + + align:start position:0% +here's the contours of the function and + + + align:start position:0% +here's the contours of the function and +the solution has to live on this line + + align:start position:0% +the solution has to live on this line + + + align:start position:0% +the solution has to live on this line +okay so I get to stand on this line and + + align:start position:0% +okay so I get to stand on this line and + + + align:start position:0% +okay so I get to stand on this line and +I get to walk and walk and walk until I + + align:start position:0% +I get to walk and walk and walk until I + + + align:start position:0% +I get to walk and walk and walk until I +can't walk downhill anymore and I got to + + align:start position:0% +can't walk downhill anymore and I got to + + + align:start position:0% +can't walk downhill anymore and I got to +turn and walk uphill again and you can + + align:start position:0% +turn and walk uphill again and you can + + + align:start position:0% +turn and walk uphill again and you can +see the point right where I can't walk + + align:start position:0% +see the point right where I can't walk + + + align:start position:0% +see the point right where I can't walk +downhill anymore it's the place where + + align:start position:0% +downhill anymore it's the place where + + + align:start position:0% +downhill anymore it's the place where +this constraint is parallel to the + + align:start position:0% +this constraint is parallel to the + + + align:start position:0% +this constraint is parallel to the +contour or where the gradient right of + + align:start position:0% +contour or where the gradient right of + + + align:start position:0% +contour or where the gradient right of +the objective function is parallel to + + align:start position:0% +the objective function is parallel to + + + align:start position:0% +the objective function is parallel to +the gradient of the constraint so you + + align:start position:0% +the gradient of the constraint so you + + + align:start position:0% +the gradient of the constraint so you +can you can actually find this point by + + align:start position:0% +can you can actually find this point by + + + align:start position:0% +can you can actually find this point by +imagining yourself moving along this + + align:start position:0% +imagining yourself moving along this + + + align:start position:0% +imagining yourself moving along this +landscape after I get to this point I + + align:start position:0% +landscape after I get to this point I + + + align:start position:0% +landscape after I get to this point I +start going uphill again right so that's + + align:start position:0% +start going uphill again right so that's + + + align:start position:0% +start going uphill again right so that's +the method of LaGrange multipliers + + align:start position:0% +the method of LaGrange multipliers + + + align:start position:0% +the method of LaGrange multipliers +minimize f of X subject to this + + align:start position:0% +minimize f of X subject to this + + + align:start position:0% +minimize f of X subject to this +constraint the solution is given by the + + align:start position:0% +constraint the solution is given by the + + + align:start position:0% +constraint the solution is given by the +point X at which the gradient is + + align:start position:0% +point X at which the gradient is + + + align:start position:0% +point X at which the gradient is +parallel to the gradient of C and at + + align:start position:0% +parallel to the gradient of C and at + + + align:start position:0% +parallel to the gradient of C and at +which C is equal to 0 and you solve the + + align:start position:0% +which C is equal to 0 and you solve the + + + align:start position:0% +which C is equal to 0 and you solve the +system of nonlinear equations for two + + align:start position:0% +system of nonlinear equations for two + + + align:start position:0% +system of nonlinear equations for two +unknowns one is X and the other is this + + align:start position:0% +unknowns one is X and the other is this + + + align:start position:0% +unknowns one is X and the other is this +unknown lambda right what is you know + + align:start position:0% +unknown lambda right what is you know + + + align:start position:0% +unknown lambda right what is you know +how far stretched is the gradient + + align:start position:0% +how far stretched is the gradient + + + align:start position:0% +how far stretched is the gradient +relative in F relative to the gradient + + align:start position:0% +relative in F relative to the gradient + + + align:start position:0% +relative in F relative to the gradient +in C so again we've turned the + + align:start position:0% +in C so again we've turned the + + + align:start position:0% +in C so again we've turned the +minimization problem into a system of + + align:start position:0% +minimization problem into a system of + + + align:start position:0% +minimization problem into a system of +non-linear equations in order to satisfy + + align:start position:0% +non-linear equations in order to satisfy + + + align:start position:0% +non-linear equations in order to satisfy +the Equality constraint we've had to + + align:start position:0% +the Equality constraint we've had to + + + align:start position:0% +the Equality constraint we've had to +introduce another unknown the Lagrange + + align:start position:0% +introduce another unknown the Lagrange + + + align:start position:0% +introduce another unknown the Lagrange +multiplier it turns out write this + + align:start position:0% +multiplier it turns out write this + + + align:start position:0% +multiplier it turns out write this +solution set X and lambda is a critical + + align:start position:0% +solution set X and lambda is a critical + + + align:start position:0% +solution set X and lambda is a critical +point of something called the Lagrangian + + align:start position:0% +point of something called the Lagrangian + + + align:start position:0% +point of something called the Lagrangian +right it's a function + + align:start position:0% +right it's a function + + + align:start position:0% +right it's a function +f of X minus lambda times C it's a + + align:start position:0% +f of X minus lambda times C it's a + + + align:start position:0% +f of X minus lambda times C it's a +critical point in X and lambda of this + + align:start position:0% +critical point in X and lambda of this + + + align:start position:0% +critical point in X and lambda of this +nonlinear function called the Lagrangian + + align:start position:0% +nonlinear function called the Lagrangian + + + align:start position:0% +nonlinear function called the Lagrangian +it's not a minimum of this function + + align:start position:0% +it's not a minimum of this function + + + align:start position:0% +it's not a minimum of this function +unfortunately it's a saddle point of the + + align:start position:0% +unfortunately it's a saddle point of the + + + align:start position:0% +unfortunately it's a saddle point of the +Lagrangian it turns out so we're trying + + align:start position:0% +Lagrangian it turns out so we're trying + + + align:start position:0% +Lagrangian it turns out so we're trying +to find a saddle point of the Lagrangian + + align:start position:0% +to find a saddle point of the Lagrangian + + + align:start position:0% +to find a saddle point of the Lagrangian +this makes sense yes okay we're going to + + align:start position:0% +this makes sense yes okay we're going to + + + align:start position:0% +this makes sense yes okay we're going to +be careful of course just like with + + align:start position:0% +be careful of course just like with + + + align:start position:0% +be careful of course just like with +unconstrained optimization we've still + + align:start position:0% +unconstrained optimization we've still + + + align:start position:0% +unconstrained optimization we've still +got a check that our solution is a + + align:start position:0% +got a check that our solution is a + + + align:start position:0% +got a check that our solution is a +minimum right + + align:start position:0% +minimum right + + + align:start position:0% +minimum right +we can't take for granted we can't can't + + align:start position:0% +we can't take for granted we can't can't + + + align:start position:0% +we can't take for granted we can't can't +suppose that our non-linear solver found + + align:start position:0% +suppose that our non-linear solver found + + + align:start position:0% +suppose that our non-linear solver found +a minimum when it solved this equation + + align:start position:0% +a minimum when it solved this equation + + + align:start position:0% +a minimum when it solved this equation +right other critical points can satisfy + + align:start position:0% +right other critical points can satisfy + + + align:start position:0% +right other critical points can satisfy +this equation too so we got to go back + + align:start position:0% +this equation too so we got to go back + + + align:start position:0% +this equation too so we got to go back +and try to check robustly whether + + align:start position:0% +and try to check robustly whether + + + align:start position:0% +and try to check robustly whether +whether it's actually a minimum but this + + align:start position:0% +whether it's actually a minimum but this + + + align:start position:0% +whether it's actually a minimum but this +is the method introduce an additional + + align:start position:0% +is the method introduce an additional + + + align:start position:0% +is the method introduce an additional +unknown the Lagrange multiplier because + + align:start position:0% +unknown the Lagrange multiplier because + + + align:start position:0% +unknown the Lagrange multiplier because +you can show geometrically that the + + align:start position:0% +you can show geometrically that the + + + align:start position:0% +you can show geometrically that the +gradient of the objective function + + align:start position:0% +gradient of the objective function + + + align:start position:0% +gradient of the objective function +should be parallel to the gradient of + + align:start position:0% +should be parallel to the gradient of + + + align:start position:0% +should be parallel to the gradient of +the constraint at the minimum does that + + align:start position:0% +the constraint at the minimum does that + + + align:start position:0% +the constraint at the minimum does that +make sense this picture makes sense okay + + align:start position:0% +make sense this picture makes sense okay + + + align:start position:0% +make sense this picture makes sense okay +so you know how to solve systems of + + align:start position:0% +so you know how to solve systems of + + + align:start position:0% +so you know how to solve systems of +nonlinear equations you know how to + + align:start position:0% +nonlinear equations you know how to + + + align:start position:0% +nonlinear equations you know how to +solve constrained optimization problems + + align:start position:0% + + + + align:start position:0% + +so here's F here's C right we can + + align:start position:0% +so here's F here's C right we can + + + align:start position:0% +so here's F here's C right we can +actually write out what these equations + + align:start position:0% +actually write out what these equations + + + align:start position:0% +actually write out what these equations +are so you can show that the gradient of + + align:start position:0% +are so you can show that the gradient of + + + align:start position:0% +are so you can show that the gradient of +X minus lambda gradient of C that's a + + align:start position:0% +X minus lambda gradient of C that's a + + + align:start position:0% +X minus lambda gradient of C that's a +vector to x1 minus lambda and 20 X 2 + + align:start position:0% +vector to x1 minus lambda and 20 X 2 + + + align:start position:0% +vector to x1 minus lambda and 20 X 2 +plus lambda and C is the equation for + + align:start position:0% +plus lambda and C is the equation for + + + align:start position:0% +plus lambda and C is the equation for +this line down here so x1 minus x2 minus + + align:start position:0% +this line down here so x1 minus x2 minus + + + align:start position:0% +this line down here so x1 minus x2 minus +3 and that's all got to be equal to 0 + + align:start position:0% +3 and that's all got to be equal to 0 + + + align:start position:0% +3 and that's all got to be equal to 0 +right in this case this is just the + + align:start position:0% +right in this case this is just the + + + align:start position:0% +right in this case this is just the +system of linear equations so you can + + align:start position:0% +system of linear equations so you can + + + align:start position:0% +system of linear equations so you can +actually solve directly for x1 x2 and + + align:start position:0% +actually solve directly for x1 x2 and + + + align:start position:0% +actually solve directly for x1 x2 and +lambda + + align:start position:0% +lambda + + + align:start position:0% +lambda +that's not too difficult to find the + + align:start position:0% +that's not too difficult to find the + + + align:start position:0% +that's not too difficult to find the +solution for all three of these things + + align:start position:0% +solution for all three of these things + + + align:start position:0% +solution for all three of these things +by hand + + align:start position:0% +by hand + + + align:start position:0% +by hand +ok but in general right these + + align:start position:0% +ok but in general right these + + + align:start position:0% +ok but in general right these +constraints can be nonlinear the + + align:start position:0% +constraints can be nonlinear the + + + align:start position:0% +constraints can be nonlinear the +objective function doesn't have to be + + align:start position:0% +objective function doesn't have to be + + + align:start position:0% +objective function doesn't have to be +quadratic those are the easiest cases to + + align:start position:0% +quadratic those are the easiest cases to + + + align:start position:0% +quadratic those are the easiest cases to +look at the same methodology applies so + + align:start position:0% +look at the same methodology applies so + + + align:start position:0% +look at the same methodology applies so +you should check that you're able to do + + align:start position:0% +you should check that you're able to do + + + align:start position:0% +you should check that you're able to do +this this is the simple responsible + + align:start position:0% +this this is the simple responsible + + + align:start position:0% +this this is the simple responsible +equality constraint problem you can do + + align:start position:0% +equality constraint problem you can do + + + align:start position:0% +equality constraint problem you can do +it by hand you should check that you're + + align:start position:0% +it by hand you should check that you're + + + align:start position:0% +it by hand you should check that you're +actually able to do it that you + + align:start position:0% +actually able to do it that you + + + align:start position:0% +actually able to do it that you +understand the steps that go into + + align:start position:0% +understand the steps that go into + + + align:start position:0% +understand the steps that go into +writing out these equations okay let's + + align:start position:0% +writing out these equations okay let's + + + align:start position:0% +writing out these equations okay let's +just take one step forward and look at + + align:start position:0% +just take one step forward and look at + + + align:start position:0% +just take one step forward and look at +the a less generic case one in which we + + align:start position:0% +the a less generic case one in which we + + + align:start position:0% +the a less generic case one in which we +have a vector valued function that gives + + align:start position:0% +have a vector valued function that gives + + + align:start position:0% +have a vector valued function that gives +thee that gives the Equality constraints + + align:start position:0% +thee that gives the Equality constraints + + + align:start position:0% +thee that gives the Equality constraints +instead so rather than one equation we + + align:start position:0% +instead so rather than one equation we + + + align:start position:0% +instead so rather than one equation we +have to satisfy there may be many okay + + align:start position:0% +have to satisfy there may be many okay + + + align:start position:0% +have to satisfy there may be many okay +it's possible right that the feasible + + align:start position:0% +it's possible right that the feasible + + + align:start position:0% +it's possible right that the feasible +set doesn't have any solutions in it + + align:start position:0% +set doesn't have any solutions in it + + + align:start position:0% +set doesn't have any solutions in it +right it's possible that there is no X + + align:start position:0% +right it's possible that there is no X + + + align:start position:0% +right it's possible that there is no X +that satisfies all of these constraints + + align:start position:0% +that satisfies all of these constraints + + + align:start position:0% +that satisfies all of these constraints +simultaneously that's a bad problem to + + align:start position:0% +simultaneously that's a bad problem to + + + align:start position:0% +simultaneously that's a bad problem to +have right you wouldn't you wouldn't + + align:start position:0% +have right you wouldn't you wouldn't + + + align:start position:0% +have right you wouldn't you wouldn't +like to have that problem very much but + + align:start position:0% +like to have that problem very much but + + + align:start position:0% +like to have that problem very much but +it's possible that that's the case but + + align:start position:0% +it's possible that that's the case but + + + align:start position:0% +it's possible that that's the case but +let's assume that there are solutions + + align:start position:0% +let's assume that there are solutions + + + align:start position:0% +let's assume that there are solutions +for the time being okay so there are X's + + align:start position:0% +for the time being okay so there are X's + + + align:start position:0% +for the time being okay so there are X's +that satisfy the Equality constraint + + align:start position:0% +that satisfy the Equality constraint + + + align:start position:0% +that satisfy the Equality constraint +let's see if we can figure out again + + align:start position:0% +let's see if we can figure out again + + + align:start position:0% +let's see if we can figure out again +what the necessary conditions for + + align:start position:0% +what the necessary conditions for + + + align:start position:0% +what the necessary conditions for +defining a minima are so it's same as + + align:start position:0% +defining a minima are so it's same as + + + align:start position:0% +defining a minima are so it's same as +before + + align:start position:0% +before + + + align:start position:0% +before +let's Taylor expand f of X in some going + + align:start position:0% +let's Taylor expand f of X in some going + + + align:start position:0% +let's Taylor expand f of X in some going +in some direction D and let's make D a + + align:start position:0% +in some direction D and let's make D a + + + align:start position:0% +in some direction D and let's make D a +nice small step so we can just treat the + + align:start position:0% +nice small step so we can just treat the + + + align:start position:0% +nice small step so we can just treat the +f of X plus D as a linearized function + + align:start position:0% +f of X plus D as a linearized function + + + align:start position:0% +f of X plus D as a linearized function +so you can see again that G has to be + + align:start position:0% +so you can see again that G has to be + + + align:start position:0% +so you can see again that G has to be +perpendicular to this direction D if + + align:start position:0% +perpendicular to this direction D if + + + align:start position:0% +perpendicular to this direction D if +we're gonna have a minima otherwise I + + align:start position:0% +we're gonna have a minima otherwise I + + + align:start position:0% +we're gonna have a minima otherwise I +could step in some direction D and I'll + + align:start position:0% +could step in some direction D and I'll + + + align:start position:0% +could step in some direction D and I'll +make I'll find either a smaller value of + + align:start position:0% +make I'll find either a smaller value of + + + align:start position:0% +make I'll find either a smaller value of +f of X plus D or a bigger value of f of + + align:start position:0% +f of X plus D or a bigger value of f of + + + align:start position:0% +f of X plus D or a bigger value of f of +X plus D okay so G has to be + + align:start position:0% +X plus D okay so G has to be + + + align:start position:0% +X plus D okay so G has to be +perpendicular to D and for the Equality + + align:start position:0% +perpendicular to D and for the Equality + + + align:start position:0% +perpendicular to D and for the Equality +constraints again they all have to + + align:start position:0% +constraints again they all have to + + + align:start position:0% +constraints again they all have to +satisfy right this equality constraint + + align:start position:0% +satisfy right this equality constraint + + + align:start position:0% +satisfy right this equality constraint +up there so C of X but C of X has to be + + align:start position:0% +up there so C of X but C of X has to be + + + align:start position:0% +up there so C of X but C of X has to be +equal to 0 and C of X plus D also has to + + align:start position:0% +equal to 0 and C of X plus D also has to + + + align:start position:0% +equal to 0 and C of X plus D also has to +be equal to 0 and so right if we take a + + align:start position:0% +be equal to 0 and so right if we take a + + + align:start position:0% +be equal to 0 and so right if we take a +Taylor expansion of C of x plus D about + + align:start position:0% +Taylor expansion of C of x plus D about + + + align:start position:0% +Taylor expansion of C of x plus D about +X right you'll get C of x plus D plus + + align:start position:0% +X right you'll get C of x plus D plus + + + align:start position:0% +X right you'll get C of x plus D plus +the Jacobian of C right all the partial + + align:start position:0% +the Jacobian of C right all the partial + + + align:start position:0% +the Jacobian of C right all the partial +derivatives of C with respect to X + + align:start position:0% +derivatives of C with respect to X + + + align:start position:0% +derivatives of C with respect to X +multiplied by D we know that C of x plus + + align:start position:0% +multiplied by D we know that C of x plus + + + align:start position:0% +multiplied by D we know that C of x plus +D is 0 and C of X is 0 so the directions + + align:start position:0% +D is 0 and C of X is 0 so the directions + + + align:start position:0% +D is 0 and C of X is 0 so the directions +D belong to what set of vectors the null + + align:start position:0% +D belong to what set of vectors the null + + + align:start position:0% +D belong to what set of vectors the null +space right so these directions have to + + align:start position:0% +space right so these directions have to + + + align:start position:0% +space right so these directions have to +live in the null space of the Jacobian + + align:start position:0% +live in the null space of the Jacobian + + + align:start position:0% +live in the null space of the Jacobian +of C + + align:start position:0% +of C + + + align:start position:0% +of C +so I can't step in any direction I have + + align:start position:0% +so I can't step in any direction I have + + + align:start position:0% +so I can't step in any direction I have +to step in directions that are in the + + align:start position:0% +to step in directions that are in the + + + align:start position:0% +to step in directions that are in the +null space of C G is perpendicular to D + + align:start position:0% +null space of C G is perpendicular to D + + + align:start position:0% +null space of C G is perpendicular to D +as well and D belongs to the null space + + align:start position:0% +as well and D belongs to the null space + + + align:start position:0% +as well and D belongs to the null space +of C in fact you know that D is + + align:start position:0% +of C in fact you know that D is + + + align:start position:0% +of C in fact you know that D is +perpendicular to each of the rows of the + + align:start position:0% +perpendicular to each of the rows of the + + + align:start position:0% +perpendicular to each of the rows of the +Jacobian right you know that I just do + + align:start position:0% +Jacobian right you know that I just do + + + align:start position:0% +Jacobian right you know that I just do +the matrix vector product right and so + + align:start position:0% +the matrix vector product right and so + + + align:start position:0% +the matrix vector product right and so +each element of this matrix vector + + align:start position:0% +each element of this matrix vector + + + align:start position:0% +each element of this matrix vector +product is the is the dot product of D + + align:start position:0% +product is the is the dot product of D + + + align:start position:0% +product is the is the dot product of D +with a different row of the Jacobian so + + align:start position:0% +with a different row of the Jacobian so + + + align:start position:0% +with a different row of the Jacobian so +those rows are set of vectors those rows + + align:start position:0% +those rows are set of vectors those rows + + + align:start position:0% +those rows are set of vectors those rows +describe the range of J transpose okay + + align:start position:0% +describe the range of J transpose okay + + + align:start position:0% +describe the range of J transpose okay +or the row space of J remember we talked + + align:start position:0% +or the row space of J remember we talked + + + align:start position:0% +or the row space of J remember we talked +about the four fundamental subspaces and + + align:start position:0% +about the four fundamental subspaces and + + + align:start position:0% +about the four fundamental subspaces and +I said we've almost never used those + + align:start position:0% +I said we've almost never used those + + + align:start position:0% +I said we've almost never used those +other ones but this is this is one time + + align:start position:0% +other ones but this is this is one time + + + align:start position:0% +other ones but this is this is one time +when we will so those rows belong to the + + align:start position:0% +when we will so those rows belong to the + + + align:start position:0% +when we will so those rows belong to the +range of J transpose or they belong to + + align:start position:0% +range of J transpose or they belong to + + + align:start position:0% +range of J transpose or they belong to +the left null space of J I need to find + + align:start position:0% +the left null space of J I need to find + + + align:start position:0% +the left null space of J I need to find +aji a gradient which is always + + align:start position:0% +aji a gradient which is always + + + align:start position:0% +aji a gradient which is always +perpendicular to D and I know D is + + align:start position:0% +perpendicular to D and I know D is + + + align:start position:0% +perpendicular to D and I know D is +always perpendicular to the rows of J so + + align:start position:0% +always perpendicular to the rows of J so + + + align:start position:0% +always perpendicular to the rows of J so +I can write GE as a linear superposition + + align:start position:0% +I can write GE as a linear superposition + + + align:start position:0% +I can write GE as a linear superposition +of the rows of J right as long as G is a + + align:start position:0% +of the rows of J right as long as G is a + + + align:start position:0% +of the rows of J right as long as G is a +linear superposition of the rows it'll + + align:start position:0% +linear superposition of the rows it'll + + + align:start position:0% +linear superposition of the rows it'll +always be perpendicular to D vectors + + align:start position:0% +always be perpendicular to D vectors + + + align:start position:0% +always be perpendicular to D vectors +from the null space of a matrix are + + align:start position:0% +from the null space of a matrix are + + + align:start position:0% +from the null space of a matrix are +orthogonal to vectors from the row space + + align:start position:0% +orthogonal to vectors from the row space + + + align:start position:0% +orthogonal to vectors from the row space +of that matrix it turns out and they're + + align:start position:0% +of that matrix it turns out and they're + + + align:start position:0% +of that matrix it turns out and they're +orthogonal for this reason okay + + align:start position:0% + + + + align:start position:0% + +so it tells us right if JD is 0 right + + align:start position:0% +so it tells us right if JD is 0 right + + + align:start position:0% +so it tells us right if JD is 0 right +then D belongs to the null space G is + + align:start position:0% +then D belongs to the null space G is + + + align:start position:0% +then D belongs to the null space G is +perpendicular to D that means I could + + align:start position:0% +perpendicular to D that means I could + + + align:start position:0% +perpendicular to D that means I could +write G as a linear superposition of the + + align:start position:0% +write G as a linear superposition of the + + + align:start position:0% +write G as a linear superposition of the +rows of J so G belongs to the range of J + + align:start position:0% +rows of J so G belongs to the range of J + + + align:start position:0% +rows of J so G belongs to the range of J +transpose or belongs to the row space of + + align:start position:0% +transpose or belongs to the row space of + + + align:start position:0% +transpose or belongs to the row space of +J those are equivalent statements and + + align:start position:0% +J those are equivalent statements and + + + align:start position:0% +J those are equivalent statements and +therefore I should be able to write G as + + align:start position:0% +therefore I should be able to write G as + + + align:start position:0% +therefore I should be able to write G as +a linear superposition of the rows of J + + align:start position:0% +a linear superposition of the rows of J + + + align:start position:0% +a linear superposition of the rows of J +and one way to say that is I should be + + align:start position:0% +and one way to say that is I should be + + + align:start position:0% +and one way to say that is I should be +able to write G as J transpose + + align:start position:0% +able to write G as J transpose + + + align:start position:0% +able to write G as J transpose +times some other vector lambda that's an + + align:start position:0% +times some other vector lambda that's an + + + align:start position:0% +times some other vector lambda that's an +equivalent way of saying that G is a + + align:start position:0% +equivalent way of saying that G is a + + + align:start position:0% +equivalent way of saying that G is a +linear superposition of the rows of J I + + align:start position:0% +linear superposition of the rows of J I + + + align:start position:0% +linear superposition of the rows of J I +don't know the values of lambda so I + + align:start position:0% +don't know the values of lambda so I + + + align:start position:0% +don't know the values of lambda so I +introduced a new set of unknowns a set + + align:start position:0% +introduced a new set of unknowns a set + + + align:start position:0% +introduced a new set of unknowns a set +of LaGrange multipliers I need to my + + align:start position:0% +of LaGrange multipliers I need to my + + + align:start position:0% +of LaGrange multipliers I need to my +minima is going to be found when I + + align:start position:0% +minima is going to be found when I + + + align:start position:0% +minima is going to be found when I +satisfy this equation just like before + + align:start position:0% +satisfy this equation just like before + + + align:start position:0% +satisfy this equation just like before +and when I'm able to satisfy all of the + + align:start position:0% +and when I'm able to satisfy all of the + + + align:start position:0% +and when I'm able to satisfy all of the +equality constraints how many LaGrant + + align:start position:0% +equality constraints how many LaGrant + + + align:start position:0% +equality constraints how many LaGrant +appliers do I have here can you figure + + align:start position:0% +appliers do I have here can you figure + + + align:start position:0% +appliers do I have here can you figure +that out you can talk with your top of + + align:start position:0% +that out you can talk with your top of + + + align:start position:0% +that out you can talk with your top of +your neighbors if you want take a couple + + align:start position:0% +your neighbors if you want take a couple + + + align:start position:0% +your neighbors if you want take a couple +minutes tell me how many Lagrange + + align:start position:0% +minutes tell me how many Lagrange + + + align:start position:0% +minutes tell me how many Lagrange +multipliers how many elements are in + + align:start position:0% +multipliers how many elements are in + + + align:start position:0% +multipliers how many elements are in +this vector lambda + + align:start position:0% + + + + align:start position:0% + +how many elements are in lambda can you + + align:start position:0% +how many elements are in lambda can you + + + align:start position:0% +how many elements are in lambda can you +tell me - yes right it's the same as the + + align:start position:0% +tell me - yes right it's the same as the + + + align:start position:0% +tell me - yes right it's the same as the +number of equality constraints right J + + align:start position:0% +number of equality constraints right J + + + align:start position:0% +number of equality constraints right J +right came from the gradient of C okay + + align:start position:0% +right came from the gradient of C okay + + + align:start position:0% +right came from the gradient of C okay +it's the Jacobian of C so it has a + + align:start position:0% +it's the Jacobian of C so it has a + + + align:start position:0% +it's the Jacobian of C so it has a +number of columns equal to the number of + + align:start position:0% +number of columns equal to the number of + + + align:start position:0% +number of columns equal to the number of +elements in X because I'm taking partial + + align:start position:0% +elements in X because I'm taking partial + + + align:start position:0% +elements in X because I'm taking partial +derivatives with respect to each element + + align:start position:0% +derivatives with respect to each element + + + align:start position:0% +derivatives with respect to each element +of X and as a number of rows equal to + + align:start position:0% +of X and as a number of rows equal to + + + align:start position:0% +of X and as a number of rows equal to +the number of elements of C okay so J + + align:start position:0% +the number of elements of C okay so J + + + align:start position:0% +the number of elements of C okay so J +transpose I just transposed those + + align:start position:0% +transpose I just transposed those + + + align:start position:0% +transpose I just transposed those +dimensions and lambda right must have + + align:start position:0% +dimensions and lambda right must have + + + align:start position:0% +dimensions and lambda right must have +the same number of elements as C does in + + align:start position:0% +the same number of elements as C does in + + + align:start position:0% +the same number of elements as C does in +order to make this product make sense so + + align:start position:0% +order to make this product make sense so + + + align:start position:0% +order to make this product make sense so +I introduced a new number of unknowns + + align:start position:0% +I introduced a new number of unknowns + + + align:start position:0% +I introduced a new number of unknowns +it's equal to exactly the number of + + align:start position:0% +it's equal to exactly the number of + + + align:start position:0% +it's equal to exactly the number of +equality constraints that I had which is + + align:start position:0% +equality constraints that I had which is + + + align:start position:0% +equality constraints that I had which is +good because I'm going to make a system + + align:start position:0% +good because I'm going to make a system + + + align:start position:0% +good because I'm going to make a system +of equations right that says G of X + + align:start position:0% +of equations right that says G of X + + + align:start position:0% +of equations right that says G of X +minus J transpose lambda equals 0 and C + + align:start position:0% +minus J transpose lambda equals 0 and C + + + align:start position:0% +minus J transpose lambda equals 0 and C +of X equals 0 right and the number of + + align:start position:0% +of X equals 0 right and the number of + + + align:start position:0% +of X equals 0 right and the number of +equations here right it's the number of + + align:start position:0% +equations here right it's the number of + + + align:start position:0% +equations here right it's the number of +elements in X for this gradient and the + + align:start position:0% +elements in X for this gradient and the + + + align:start position:0% +elements in X for this gradient and the +number of elements in C for C and the + + align:start position:0% +number of elements in C for C and the + + + align:start position:0% +number of elements in C for C and the +number of unknowns is the number of + + align:start position:0% +number of unknowns is the number of + + + align:start position:0% +number of unknowns is the number of +elements in X and the number of elements + + align:start position:0% +elements in X and the number of elements + + + align:start position:0% +elements in X and the number of elements +in C associated with the LaGrant wealth + + align:start position:0% +in C associated with the LaGrant wealth + + + align:start position:0% +in C associated with the LaGrant wealth +layer so I have enough equations and + + align:start position:0% +layer so I have enough equations and + + + align:start position:0% +layer so I have enough equations and +unknowns to determine all of these + + align:start position:0% +unknowns to determine all of these + + + align:start position:0% +unknowns to determine all of these +things so whether I have one equality + + align:start position:0% +things so whether I have one equality + + + align:start position:0% +things so whether I have one equality +constraint or a million quality + + align:start position:0% +constraint or a million quality + + + align:start position:0% +constraint or a million quality +constraints right the problem is + + align:start position:0% +constraints right the problem is + + + align:start position:0% +constraints right the problem is +identical right we use the method of + + align:start position:0% +identical right we use the method of + + + align:start position:0% +identical right we use the method of +LaGrange multipliers we have to solve an + + align:start position:0% +LaGrange multipliers we have to solve an + + + align:start position:0% +LaGrange multipliers we have to solve an +Augmented system of equations for X and + + align:start position:0% +Augmented system of equations for X and + + + align:start position:0% +Augmented system of equations for X and +write this projection on the row space + + align:start position:0% +write this projection on the row space + + + align:start position:0% +write this projection on the row space +of J which tells us how the gradient is + + align:start position:0% +of J which tells us how the gradient is + + + align:start position:0% +of J which tells us how the gradient is +stretched or + + align:start position:0% +stretched or + + + align:start position:0% +stretched or +made up composed of elements of the row + + align:start position:0% +made up composed of elements of the row + + + align:start position:0% +made up composed of elements of the row +space of J these are the conditions + + align:start position:0% +space of J these are the conditions + + + align:start position:0% +space of J these are the conditions +associated with a minima in our + + align:start position:0% +associated with a minima in our + + + align:start position:0% +associated with a minima in our +objective function on this boundary + + align:start position:0% +objective function on this boundary + + + align:start position:0% +objective function on this boundary +dictated by the the Equality constraint + + align:start position:0% +dictated by the the Equality constraint + + + align:start position:0% +dictated by the the Equality constraint +and of course the solution set is a + + align:start position:0% +and of course the solution set is a + + + align:start position:0% +and of course the solution set is a +critical point of a Lagrangian which is + + align:start position:0% +critical point of a Lagrangian which is + + + align:start position:0% +critical point of a Lagrangian which is +f of X minus C dot lambda and it's not a + + align:start position:0% +f of X minus C dot lambda and it's not a + + + align:start position:0% +f of X minus C dot lambda and it's not a +minimum of it it's a critical point it's + + align:start position:0% +minimum of it it's a critical point it's + + + align:start position:0% +minimum of it it's a critical point it's +a saddle point it turns out of this + + align:start position:0% +a saddle point it turns out of this + + + align:start position:0% +a saddle point it turns out of this +Lagrangian okay so we got to check did + + align:start position:0% +Lagrangian okay so we got to check did + + + align:start position:0% +Lagrangian okay so we got to check did +we find a saddle point or not when we + + align:start position:0% +we find a saddle point or not when we + + + align:start position:0% +we find a saddle point or not when we +find a solution to this equation here + + align:start position:0% +find a solution to this equation here + + + align:start position:0% +find a solution to this equation here +okay but it's just a system of nonlinear + + align:start position:0% +okay but it's just a system of nonlinear + + + align:start position:0% +okay but it's just a system of nonlinear +equation so if we have some good initial + + align:start position:0% +equation so if we have some good initial + + + align:start position:0% +equation so if we have some good initial +guess what do we apply newton-raphson + + align:start position:0% +guess what do we apply newton-raphson + + + align:start position:0% +guess what do we apply newton-raphson +right converge rate towards the solution + + align:start position:0% +right converge rate towards the solution + + + align:start position:0% +right converge rate towards the solution +right if we don't have a good initial + + align:start position:0% +right if we don't have a good initial + + + align:start position:0% +right if we don't have a good initial +guess well you know we've discussed lots + + align:start position:0% +guess well you know we've discussed lots + + + align:start position:0% +guess well you know we've discussed lots +of methods we could employ like homotopy + + align:start position:0% +of methods we could employ like homotopy + + + align:start position:0% +of methods we could employ like homotopy +or continuation to try to develop good + + align:start position:0% +or continuation to try to develop good + + + align:start position:0% +or continuation to try to develop good +initial guesses for what the solution + + align:start position:0% +initial guesses for what the solution + + + align:start position:0% +initial guesses for what the solution +should be are there any questions about + + align:start position:0% +should be are there any questions about + + + align:start position:0% +should be are there any questions about +this good okay so this is you know so + + align:start position:0% +this good okay so this is you know so + + + align:start position:0% +this good okay so this is you know so +you go to MATLAB and you call F min con + + align:start position:0% +you go to MATLAB and you call F min con + + + align:start position:0% +you go to MATLAB and you call F min con +right do do a minimization problem to + + align:start position:0% +right do do a minimization problem to + + + align:start position:0% +right do do a minimization problem to +give us some constraints linear + + align:start position:0% +give us some constraints linear + + + align:start position:0% +give us some constraints linear +constraints non linear constraints it + + align:start position:0% +constraints non linear constraints it + + + align:start position:0% +constraints non linear constraints it +doesn't matter actually right the + + align:start position:0% +doesn't matter actually right the + + + align:start position:0% +doesn't matter actually right the +problem is the same for both of them + + align:start position:0% +problem is the same for both of them + + + align:start position:0% +problem is the same for both of them +it's just a little bit easier if I have + + align:start position:0% +it's just a little bit easier if I have + + + align:start position:0% +it's just a little bit easier if I have +linear constraints okay if this + + align:start position:0% +linear constraints okay if this + + + align:start position:0% +linear constraints okay if this +constraining function is a linear + + align:start position:0% +constraining function is a linear + + + align:start position:0% +constraining function is a linear +function then the Jacobian I know it's + + align:start position:0% +function then the Jacobian I know it's + + + align:start position:0% +function then the Jacobian I know it's +the coefficient matrix of this linear + + align:start position:0% +the coefficient matrix of this linear + + + align:start position:0% +the coefficient matrix of this linear +linear problem and I'll have to solve + + align:start position:0% +linear problem and I'll have to solve + + + align:start position:0% +linear problem and I'll have to solve +linear equations down here so the + + align:start position:0% +linear equations down here so the + + + align:start position:0% +linear equations down here so the +problem is a little bit it's a little + + align:start position:0% +problem is a little bit it's a little + + + align:start position:0% +problem is a little bit it's a little +bit simpler to solve so MATLAB sort of + + align:start position:0% +bit simpler to solve so MATLAB sort of + + + align:start position:0% +bit simpler to solve so MATLAB sort of +breaks these apart so it can use + + align:start position:0% +breaks these apart so it can use + + + align:start position:0% +breaks these apart so it can use +different techniques depending on which + + align:start position:0% +different techniques depending on which + + + align:start position:0% +different techniques depending on which +one which should a problem is posed but + + align:start position:0% +one which should a problem is posed but + + + align:start position:0% +one which should a problem is posed but +the solution method is the same it does + + align:start position:0% +the solution method is the same it does + + + align:start position:0% +the solution method is the same it does +the method of LaGrange multipliers to + + align:start position:0% +the method of LaGrange multipliers to + + + align:start position:0% +the method of LaGrange multipliers to +find the solution okay + + align:start position:0% + + + + align:start position:0% + +in equality constraints so interior + + align:start position:0% +in equality constraints so interior + + + align:start position:0% +in equality constraints so interior +point methods were mentioned and it + + align:start position:0% +point methods were mentioned and it + + + align:start position:0% +point methods were mentioned and it +turns out this is this is really the + + align:start position:0% +turns out this is this is really the + + + align:start position:0% +turns out this is this is really the +best way to go about solving generic + + align:start position:0% +best way to go about solving generic + + + align:start position:0% +best way to go about solving generic +inequality constrained problems so these + + align:start position:0% +inequality constrained problems so these + + + align:start position:0% +inequality constrained problems so these +are problems of the sort ranked minimize + + align:start position:0% +are problems of the sort ranked minimize + + + align:start position:0% +are problems of the sort ranked minimize +f of X subject to H of X is positive or + + align:start position:0% +f of X subject to H of X is positive or + + + align:start position:0% +f of X subject to H of X is positive or +at least not negative + + align:start position:0% +at least not negative + + + align:start position:0% +at least not negative +this is some non linear inequality that + + align:start position:0% +this is some non linear inequality that + + + align:start position:0% +this is some non linear inequality that +describes some domain and its boundary + + align:start position:0% +describes some domain and its boundary + + + align:start position:0% +describes some domain and its boundary +in which the solution has to live and + + align:start position:0% +in which the solution has to live and + + + align:start position:0% +in which the solution has to live and +what's done is to rewrite as an + + align:start position:0% +what's done is to rewrite as an + + + align:start position:0% +what's done is to rewrite as an +unconstrained optimization problem with + + align:start position:0% +unconstrained optimization problem with + + + align:start position:0% +unconstrained optimization problem with +the barrier that's incorporated okay + + align:start position:0% +the barrier that's incorporated okay + + + align:start position:0% +the barrier that's incorporated okay +this looks a lot like the penalty method + + align:start position:0% +this looks a lot like the penalty method + + + align:start position:0% +this looks a lot like the penalty method +but it's very different and I'll explain + + align:start position:0% +but it's very different and I'll explain + + + align:start position:0% +but it's very different and I'll explain +how right so instead we want to minimize + + align:start position:0% +how right so instead we want to minimize + + + align:start position:0% +how right so instead we want to minimize +this f of X minus mu times the sum of + + align:start position:0% +this f of X minus mu times the sum of + + + align:start position:0% +this f of X minus mu times the sum of +log of H each of these constraints okay + + align:start position:0% +log of H each of these constraints okay + + + align:start position:0% +log of H each of these constraints okay +if H is negative okay + + align:start position:0% +if H is negative okay + + + align:start position:0% +if H is negative okay +the log will be we'll take the log of a + + align:start position:0% +the log will be we'll take the log of a + + + align:start position:0% +the log will be we'll take the log of a +negative argument that's a problem + + align:start position:0% +negative argument that's a problem + + + align:start position:0% +negative argument that's a problem +computationally so the best we could do + + align:start position:0% +computationally so the best we could do + + + align:start position:0% +computationally so the best we could do +is approach the boundary where H is + + align:start position:0% +is approach the boundary where H is + + + align:start position:0% +is approach the boundary where H is +equal to zero right and as H goes to + + align:start position:0% +equal to zero right and as H goes to + + + align:start position:0% +equal to zero right and as H goes to +zero the law goes to minus infinity so + + align:start position:0% +zero the law goes to minus infinity so + + + align:start position:0% +zero the law goes to minus infinity so +this term tends to blow up because I got + + align:start position:0% +this term tends to blow up because I got + + + align:start position:0% +this term tends to blow up because I got +a minus sign in front of it right so + + align:start position:0% +a minus sign in front of it right so + + + align:start position:0% +a minus sign in front of it right so +this is sort of like a penalty but it's + + align:start position:0% +this is sort of like a penalty but it's + + + align:start position:0% +this is sort of like a penalty but it's +a little different because the factor in + + align:start position:0% +a little different because the factor in + + + align:start position:0% +a little different because the factor in +front I'm actually going to take the + + align:start position:0% +front I'm actually going to take the + + + align:start position:0% +front I'm actually going to take the +limit as mu goes to zero okay I'm gonna + + align:start position:0% +limit as mu goes to zero okay I'm gonna + + + align:start position:0% +limit as mu goes to zero okay I'm gonna +take the limit is this factor gets small + + align:start position:0% +take the limit is this factor gets small + + + align:start position:0% +take the limit is this factor gets small +rather than gets big okay the log will + + align:start position:0% +rather than gets big okay the log will + + + align:start position:0% +rather than gets big okay the log will +always get big as I approach the + + align:start position:0% +always get big as I approach the + + + align:start position:0% +always get big as I approach the +boundary of the domain right it'll blow + + align:start position:0% +boundary of the domain right it'll blow + + + align:start position:0% +boundary of the domain right it'll blow +up okay so that's not a problem but I + + align:start position:0% +up okay so that's not a problem but I + + + align:start position:0% +up okay so that's not a problem but I +can take the limit that nu gets smaller + + align:start position:0% +can take the limit that nu gets smaller + + + align:start position:0% +can take the limit that nu gets smaller +and smaller and this quantity here right + + align:start position:0% +and smaller and this quantity here right + + + align:start position:0% +and smaller and this quantity here right +will have less and less of an impact + + align:start position:0% +will have less and less of an impact + + + align:start position:0% +will have less and less of an impact +right on the shape of this new objective + + align:start position:0% +right on the shape of this new objective + + + align:start position:0% +right on the shape of this new objective +function as you get smaller and smaller + + align:start position:0% +function as you get smaller and smaller + + + align:start position:0% +function as you get smaller and smaller +right the impact will only be nearest + + align:start position:0% +right the impact will only be nearest + + + align:start position:0% +right the impact will only be nearest +the boundary that makes sense so you + + align:start position:0% +the boundary that makes sense so you + + + align:start position:0% +the boundary that makes sense so you +take the limit that mu approaches zero + + align:start position:0% +take the limit that mu approaches zero + + + align:start position:0% +take the limit that mu approaches zero +it's got to approach it from the + + align:start position:0% +it's got to approach it from the + + + align:start position:0% +it's got to approach it from the +positive side not the negative side so + + align:start position:0% +positive side not the negative side so + + + align:start position:0% +positive side not the negative side so +everything behaves well this is called + + align:start position:0% +everything behaves well this is called + + + align:start position:0% +everything behaves well this is called +an interior point method so we have to + + align:start position:0% +an interior point method so we have to + + + align:start position:0% +an interior point method so we have to +determine the minimum of this new + + align:start position:0% +determine the minimum of this new + + + align:start position:0% +determine the minimum of this new +objective function for progressively + + align:start position:0% +objective function for progressively + + + align:start position:0% +objective function for progressively +weaker barriers okay so we might start + + align:start position:0% +weaker barriers okay so we might start + + + align:start position:0% +weaker barriers okay so we might start +with some value of mu and we might + + align:start position:0% +with some value of mu and we might + + + align:start position:0% +with some value of mu and we might +reduce mu progressively right until we + + align:start position:0% +reduce mu progressively right until we + + + align:start position:0% +reduce mu progressively right until we +get me down small enough that we think + + align:start position:0% +get me down small enough that we think + + + align:start position:0% +get me down small enough that we think +we've converged to a solution so how do + + align:start position:0% +we've converged to a solution so how do + + + align:start position:0% +we've converged to a solution so how do +you do that reliably what's the + + align:start position:0% +you do that reliably what's the + + + align:start position:0% +you do that reliably what's the +procedure one uses to solve a problem + + align:start position:0% +procedure one uses to solve a problem + + + align:start position:0% +procedure one uses to solve a problem +successively for different parameter + + align:start position:0% +successively for different parameter + + + align:start position:0% +successively for different parameter +values + + align:start position:0% + + + + align:start position:0% + +yeah it's a home attabi right you're + + align:start position:0% +yeah it's a home attabi right you're + + + align:start position:0% +yeah it's a home attabi right you're +just gonna change the value of this + + align:start position:0% +just gonna change the value of this + + + align:start position:0% +just gonna change the value of this +barrier parameter right and you're gonna + + align:start position:0% +barrier parameter right and you're gonna + + + align:start position:0% +barrier parameter right and you're gonna +find a minimum if you make a small + + align:start position:0% +find a minimum if you make a small + + + align:start position:0% +find a minimum if you make a small +change in the barrier prim that's gonna + + align:start position:0% +change in the barrier prim that's gonna + + + align:start position:0% +change in the barrier prim that's gonna +serve as an excellent initial guess for + + align:start position:0% +serve as an excellent initial guess for + + + align:start position:0% +serve as an excellent initial guess for +the next value right and so just can + + align:start position:0% +the next value right and so just can + + + align:start position:0% +the next value right and so just can +take these small steps right and the + + align:start position:0% +take these small steps right and the + + + align:start position:0% +take these small steps right and the +optimization routine is going to carry + + align:start position:0% +optimization routine is going to carry + + + align:start position:0% +optimization routine is going to carry +you towards the minimum in the limit + + align:start position:0% +you towards the minimum in the limit + + + align:start position:0% +you towards the minimum in the limit +that mu goes to zero so you do this with + + align:start position:0% +that mu goes to zero so you do this with + + + align:start position:0% +that mu goes to zero so you do this with +hama toffee here's an example of this + + align:start position:0% +hama toffee here's an example of this + + + align:start position:0% +hama toffee here's an example of this +sort of interior point method a trivial + + align:start position:0% +sort of interior point method a trivial + + + align:start position:0% +sort of interior point method a trivial +example right minimize X subject to X + + align:start position:0% +example right minimize X subject to X + + + align:start position:0% +example right minimize X subject to X +being positive we know the solution + + align:start position:0% +being positive we know the solution + + + align:start position:0% +being positive we know the solution +lives where x equals zero but let's + + align:start position:0% +lives where x equals zero but let's + + + align:start position:0% +lives where x equals zero but let's +write this as unconstrained optimization + + align:start position:0% +write this as unconstrained optimization + + + align:start position:0% +write this as unconstrained optimization +using a barrier so minimize X minus mu + + align:start position:0% +using a barrier so minimize X minus mu + + + align:start position:0% +using a barrier so minimize X minus mu +times log X here's X minus mu times log + + align:start position:0% +times log X here's X minus mu times log + + + align:start position:0% +times log X here's X minus mu times log +X so out here where X is big okay + + align:start position:0% +X so out here where X is big okay + + + align:start position:0% +X so out here where X is big okay +X wins over log X so everything starts + + align:start position:0% +X wins over log X so everything starts + + + align:start position:0% +X wins over log X so everything starts +to look linear but as X becomes smaller + + align:start position:0% +to look linear but as X becomes smaller + + + align:start position:0% +to look linear but as X becomes smaller +and smaller log X gets very negative so + + align:start position:0% +and smaller log X gets very negative so + + + align:start position:0% +and smaller log X gets very negative so +minus log X gets very positive and + + align:start position:0% +minus log X gets very positive and + + + align:start position:0% +minus log X gets very positive and +here's the log creeping back up and as I + + align:start position:0% +here's the log creeping back up and as I + + + align:start position:0% +here's the log creeping back up and as I +decrease Mew smaller and smaller you can + + align:start position:0% +decrease Mew smaller and smaller you can + + + align:start position:0% +decrease Mew smaller and smaller you can +see the minimum of this function is + + align:start position:0% +see the minimum of this function is + + + align:start position:0% +see the minimum of this function is +moving closer and closer and closer to + + align:start position:0% +moving closer and closer and closer to + + + align:start position:0% +moving closer and closer and closer to +zero right so if I take the limit that + + align:start position:0% +zero right so if I take the limit that + + + align:start position:0% +zero right so if I take the limit that +Mew decreases from some positive number + + align:start position:0% +Mew decreases from some positive number + + + align:start position:0% +Mew decreases from some positive number +towards zero + + align:start position:0% +towards zero + + + align:start position:0% +towards zero +eventually this minimum is going to + + align:start position:0% +eventually this minimum is going to + + + align:start position:0% +eventually this minimum is going to +converge right to the minimum of the + + align:start position:0% +converge right to the minimum of the + + + align:start position:0% +converge right to the minimum of the +constrained inequality constrained + + align:start position:0% +constrained inequality constrained + + + align:start position:0% +constrained inequality constrained +optimization problem makes sense okay + + align:start position:0% +optimization problem makes sense okay + + + align:start position:0% +optimization problem makes sense okay +okay so yeah so we want to do this you + + align:start position:0% +okay so yeah so we want to do this you + + + align:start position:0% +okay so yeah so we want to do this you +can choose any barrier function you want + + align:start position:0% +can choose any barrier function you want + + + align:start position:0% +can choose any barrier function you want +any any thoughts on why a logarithmic + + align:start position:0% +any any thoughts on why a logarithmic + + + align:start position:0% +any any thoughts on why a logarithmic +barrier is used + + align:start position:0% + + + + align:start position:0% + +okay that's okay so Mike - log is gonna + + align:start position:0% +okay that's okay so Mike - log is gonna + + + align:start position:0% +okay that's okay so Mike - log is gonna +be convex log as in convex but - log is + + align:start position:0% +be convex log as in convex but - log is + + + align:start position:0% +be convex log as in convex but - log is +going to be convex so that's good okay + + align:start position:0% +going to be convex so that's good okay + + + align:start position:0% +going to be convex so that's good okay +it's gonna if this function is convex + + align:start position:0% +it's gonna if this function is convex + + + align:start position:0% +it's gonna if this function is convex +and their combinations gonna be convex + + align:start position:0% +and their combinations gonna be convex + + + align:start position:0% +and their combinations gonna be convex +Oh we'll be okay + + align:start position:0% +Oh we'll be okay + + + align:start position:0% +Oh we'll be okay +but the gradient of the log is easy to + + align:start position:0% +but the gradient of the log is easy to + + + align:start position:0% +but the gradient of the log is easy to +compute right grad log H is one over H + + align:start position:0% +compute right grad log H is one over H + + + align:start position:0% +compute right grad log H is one over H +grad H so if I know H I know grad H it's + + align:start position:0% +grad H so if I know H I know grad H it's + + + align:start position:0% +grad H so if I know H I know grad H it's +easy for me to compute the gradient of + + align:start position:0% +easy for me to compute the gradient of + + + align:start position:0% +easy for me to compute the gradient of +log H we know we're gonna solve this + + align:start position:0% +log H we know we're gonna solve this + + + align:start position:0% +log H we know we're gonna solve this +unconstrained optimization problem where + + align:start position:0% +unconstrained optimization problem where + + + align:start position:0% +unconstrained optimization problem where +we need to take grad of this objective + + align:start position:0% +we need to take grad of this objective + + + align:start position:0% +we need to take grad of this objective +function equals zero so the calculations + + align:start position:0% +function equals zero so the calculations + + + align:start position:0% +function equals zero so the calculations +are easy right the log makes it easy + + align:start position:0% +are easy right the log makes it easy + + + align:start position:0% +are easy right the log makes it easy +like that the log is also like the most + + align:start position:0% +like that the log is also like the most + + + align:start position:0% +like that the log is also like the most +weekly singular function available to us + + align:start position:0% +weekly singular function available to us + + + align:start position:0% +weekly singular function available to us +right out of all the toolbox of all + + align:start position:0% +right out of all the toolbox of all + + + align:start position:0% +right out of all the toolbox of all +problems we can reach to the log has so + + align:start position:0% +problems we can reach to the log has so + + + align:start position:0% +problems we can reach to the log has so +the mildest sort of singularities + + align:start position:0% +the mildest sort of singularities + + + align:start position:0% +the mildest sort of singularities +singularities of both ends which is sort + + align:start position:0% +singularities of both ends which is sort + + + align:start position:0% +singularities of both ends which is sort +of funny but the mildest sort of + + align:start position:0% +of funny but the mildest sort of + + + align:start position:0% +of funny but the mildest sort of +singularities you have to cope with okay + + align:start position:0% +singularities you have to cope with okay + + + align:start position:0% +singularities you have to cope with okay +so we want to find the minimum of these + + align:start position:0% +so we want to find the minimum of these + + + align:start position:0% +so we want to find the minimum of these +unconstrained optimization problems + + align:start position:0% +unconstrained optimization problems + + + align:start position:0% +unconstrained optimization problems +where the gradient of f minus mu sum 1 + + align:start position:0% +where the gradient of f minus mu sum 1 + + + align:start position:0% +where the gradient of f minus mu sum 1 +over h grad h is equal to 0 ok then we + + align:start position:0% +over h grad h is equal to 0 ok then we + + + align:start position:0% +over h grad h is equal to 0 ok then we +just do that for progressively smaller + + align:start position:0% +just do that for progressively smaller + + + align:start position:0% +just do that for progressively smaller +values of MU and will converge to a + + align:start position:0% +values of MU and will converge to a + + + align:start position:0% +values of MU and will converge to a +solution that's the interior point + + align:start position:0% +solution that's the interior point + + + align:start position:0% +solution that's the interior point +method you use homotopy right to study a + + align:start position:0% +method you use homotopy right to study a + + + align:start position:0% +method you use homotopy right to study a +sequence of barrier parameters or + + align:start position:0% +sequence of barrier parameters or + + + align:start position:0% +sequence of barrier parameters or +continuation to study sequence of + + align:start position:0% +continuation to study sequence of + + + align:start position:0% +continuation to study sequence of +barrier parameters you stop the hama + + align:start position:0% +barrier parameters you stop the hama + + + align:start position:0% +barrier parameters you stop the hama +toppy or continuation when what how are + + align:start position:0% +toppy or continuation when what how are + + + align:start position:0% +toppy or continuation when what how are +you gonna stop I got to make a new small + + align:start position:0% +you gonna stop I got to make a new small + + + align:start position:0% +you gonna stop I got to make a new small +right I want to go towards the limit mu + + align:start position:0% +right I want to go towards the limit mu + + + align:start position:0% +right I want to go towards the limit mu +equals 0 I can't actually get to mu + + align:start position:0% +equals 0 I can't actually get to mu + + + align:start position:0% +equals 0 I can't actually get to mu +equals you're alright I just going to + + align:start position:0% +equals you're alright I just going to + + + align:start position:0% +equals you're alright I just going to +approach it so how small do I need to + + align:start position:0% +approach it so how small do I need to + + + align:start position:0% +approach it so how small do I need to +make new before I quit it's an + + align:start position:0% +make new before I quit it's an + + + align:start position:0% +make new before I quit it's an +interesting question what do you think + + align:start position:0% +interesting question what do you think + + + align:start position:0% +interesting question what do you think +I'll take this answer first oh good so + + align:start position:0% +I'll take this answer first oh good so + + + align:start position:0% +I'll take this answer first oh good so +we might look at the solution and see is + + align:start position:0% +we might look at the solution and see is + + + align:start position:0% +we might look at the solution and see is +the solution becoming less and less + + align:start position:0% +the solution becoming less and less + + + align:start position:0% +the solution becoming less and less +sensitive to the choice of them you good + + align:start position:0% +sensitive to the choice of them you good + + + align:start position:0% +sensitive to the choice of them you good +did you have a did you another + + align:start position:0% +did you have a did you another + + + align:start position:0% +did you have a did you another +suggestion look is set a tolerance right + + align:start position:0% +suggestion look is set a tolerance right + + + align:start position:0% +suggestion look is set a tolerance right +okay + + align:start position:0% + + + + align:start position:0% + +hmm right rabbi right so you good so so + + align:start position:0% +hmm right rabbi right so you good so so + + + align:start position:0% +hmm right rabbi right so you good so so +there were two suggestions here one is + + align:start position:0% +there were two suggestions here one is + + + align:start position:0% +there were two suggestions here one is +one is along the lines of a step norm + + align:start position:0% +one is along the lines of a step norm + + + align:start position:0% +one is along the lines of a step norm +criteria right like I I checked my + + align:start position:0% +criteria right like I I checked my + + + align:start position:0% +criteria right like I I checked my +solution as I change mu and ask when + + align:start position:0% +solution as I change mu and ask when + + + align:start position:0% +solution as I change mu and ask when +does my solution seem relatively + + align:start position:0% +does my solution seem relatively + + + align:start position:0% +does my solution seem relatively +insensitive to MU right when the changes + + align:start position:0% +insensitive to MU right when the changes + + + align:start position:0% +insensitive to MU right when the changes +in these steps relative team you get + + align:start position:0% +in these steps relative team you get + + + align:start position:0% +in these steps relative team you get +sufficiently small right I might be + + align:start position:0% +sufficiently small right I might be + + + align:start position:0% +sufficiently small right I might be +willing to accept these solutions as + + align:start position:0% +willing to accept these solutions as + + + align:start position:0% +willing to accept these solutions as +reasonable solutions for the constrained + + align:start position:0% +reasonable solutions for the constrained + + + align:start position:0% +reasonable solutions for the constrained +optimization I can also go back and I + + align:start position:0% +optimization I can also go back and I + + + align:start position:0% +optimization I can also go back and I +can check sort of function norm right + + align:start position:0% +can check sort of function norm right + + + align:start position:0% +can check sort of function norm right +criteria right I can take the value of x + + align:start position:0% +criteria right I can take the value of x + + + align:start position:0% +criteria right I can take the value of x +I found as the minimum and I can ask + + align:start position:0% +I found as the minimum and I can ask + + + align:start position:0% +I found as the minimum and I can ask +right how good a job does it do + + align:start position:0% +right how good a job does it do + + + align:start position:0% +right how good a job does it do +satisfying right the original equations + + align:start position:0% +satisfying right the original equations + + + align:start position:0% +satisfying right the original equations +how far away am i from satisfying the + + align:start position:0% +how far away am i from satisfying the + + + align:start position:0% +how far away am i from satisfying the +inequality constraint how close am I to + + align:start position:0% +inequality constraint how close am I to + + + align:start position:0% +inequality constraint how close am I to +actually minimizing the function within + + align:start position:0% +actually minimizing the function within + + + align:start position:0% +actually minimizing the function within +that domain okay so we're running out of + + align:start position:0% +that domain okay so we're running out of + + + align:start position:0% +that domain okay so we're running out of +time here let me provide you with an + + align:start position:0% +time here let me provide you with an + + + align:start position:0% +time here let me provide you with an +example so let's minimize again I'd + + align:start position:0% +example so let's minimize again I'd + + + align:start position:0% +example so let's minimize again I'd +always pick this function because it's + + align:start position:0% +always pick this function because it's + + + align:start position:0% +always pick this function because it's +easy to visualize right a nice parabolic + + align:start position:0% +easy to visualize right a nice parabolic + + + align:start position:0% +easy to visualize right a nice parabolic +function it opens upwards and let's + + align:start position:0% +function it opens upwards and let's + + + align:start position:0% +function it opens upwards and let's +minimize it subject to the constraint + + align:start position:0% +minimize it subject to the constraint + + + align:start position:0% +minimize it subject to the constraint +right that H of X 1 and X 2 is equal to + + align:start position:0% +right that H of X 1 and X 2 is equal to + + + align:start position:0% +right that H of X 1 and X 2 is equal to +1 minus well the equation for a circle + + align:start position:0% +1 minus well the equation for a circle + + + align:start position:0% +1 minus well the equation for a circle +of radius 1 essentially the interior of + + align:start position:0% +of radius 1 essentially the interior of + + + align:start position:0% +of radius 1 essentially the interior of +that circle ok so here's the contours of + + align:start position:0% +that circle ok so here's the contours of + + + align:start position:0% +that circle ok so here's the contours of +the function and this red domain is the + + align:start position:0% +the function and this red domain is the + + + align:start position:0% +the function and this red domain is the +constraint we want to know the smallest + + align:start position:0% +constraint we want to know the smallest + + + align:start position:0% +constraint we want to know the smallest +value of f that lives in this domain all + + align:start position:0% +value of f that lives in this domain all + + + align:start position:0% +value of f that lives in this domain all +right so here's some MATLAB code you can + + align:start position:0% +right so here's some MATLAB code you can + + + align:start position:0% +right so here's some MATLAB code you can +try it out right and make a function the + + align:start position:0% +try it out right and make a function the + + + align:start position:0% +try it out right and make a function the +objective function f right it's x + + align:start position:0% +objective function f right it's x + + + align:start position:0% +objective function f right it's x +squared plus 10x X 1 squared plus 10x 2 + + align:start position:0% +squared plus 10x X 1 squared plus 10x 2 + + + align:start position:0% +squared plus 10x X 1 squared plus 10x 2 +squared here's the gradient here's the + + align:start position:0% +squared here's the gradient here's the + + + align:start position:0% +squared here's the gradient here's the +Hessian ok here I calculate H here's the + + align:start position:0% +Hessian ok here I calculate H here's the + + + align:start position:0% +Hessian ok here I calculate H here's the +gradient in H here's the Hessian NH I + + align:start position:0% +gradient in H here's the Hessian NH I + + + align:start position:0% +gradient in H here's the Hessian NH I +get to define a new objective function V + + align:start position:0% +get to define a new objective function V + + + align:start position:0% +get to define a new objective function V +which is f minus nu log H this is the + + align:start position:0% +which is f minus nu log H this is the + + + align:start position:0% +which is f minus nu log H this is the +gradient in fee and this is the Hessian + + align:start position:0% +gradient in fee and this is the Hessian + + + align:start position:0% +gradient in fee and this is the Hessian +of fee oh man what a mess but actually + + align:start position:0% +of fee oh man what a mess but actually + + + align:start position:0% +of fee oh man what a mess but actually +not such a mess because the log makes it + + align:start position:0% +not such a mess because the log makes it + + + align:start position:0% +not such a mess because the log makes it +really easy to take these derivatives ok + + align:start position:0% +really easy to take these derivatives ok + + + align:start position:0% +really easy to take these derivatives ok +just just a lot of valley you know a lot + + align:start position:0% +just just a lot of valley you know a lot + + + align:start position:0% +just just a lot of valley you know a lot +of differential sort of calculus + + align:start position:0% +of differential sort of calculus + + + align:start position:0% +of differential sort of calculus +involved in working this out but this is + + align:start position:0% +involved in working this out but this is + + + align:start position:0% +involved in working this out but this is +the Hessian of fee and then I need some + + align:start position:0% +the Hessian of fee and then I need some + + + align:start position:0% +the Hessian of fee and then I need some +initial guess so I pick pick the center + + align:start position:0% +initial guess so I pick pick the center + + + align:start position:0% +initial guess so I pick pick the center +of my circle as an initial guess for the + + align:start position:0% +of my circle as an initial guess for the + + + align:start position:0% +of my circle as an initial guess for the +solution and I'm gonna loop over values + + align:start position:0% +solution and I'm gonna loop over values + + + align:start position:0% +solution and I'm gonna loop over values +of MU that get progressively smaller + + align:start position:0% +of MU that get progressively smaller + + + align:start position:0% +of MU that get progressively smaller +I'll just go down to ten to the minus + + align:start position:0% +I'll just go down to ten to the minus + + + align:start position:0% +I'll just go down to ten to the minus +two and stop for illustration purposes + + align:start position:0% +two and stop for illustration purposes + + + align:start position:0% +two and stop for illustration purposes +here but really we should be checking + + align:start position:0% +here but really we should be checking + + + align:start position:0% +here but really we should be checking +the solution as we go and deciding what + + align:start position:0% +the solution as we go and deciding what + + + align:start position:0% +the solution as we go and deciding what +values we want to stop with and then + + align:start position:0% +values we want to stop with and then + + + align:start position:0% +values we want to stop with and then +this loop here what's this do + + align:start position:0% + + + + align:start position:0% + +what's it do + + align:start position:0% +what's it do + + + align:start position:0% +what's it do +can you tell what's that yeah it's nuva + + align:start position:0% +can you tell what's that yeah it's nuva + + + align:start position:0% +can you tell what's that yeah it's nuva +raphson right X is X minus Hessian + + align:start position:0% +raphson right X is X minus Hessian + + + align:start position:0% +raphson right X is X minus Hessian +inverse times grad fee right so I just + + align:start position:0% +inverse times grad fee right so I just + + + align:start position:0% +inverse times grad fee right so I just +do newton-raphson I take my initial + + align:start position:0% +do newton-raphson I take my initial + + + align:start position:0% +do newton-raphson I take my initial +guess and I whip around with + + align:start position:0% +guess and I whip around with + + + align:start position:0% +guess and I whip around with +newton-raphson and when this loop + + align:start position:0% +newton-raphson and when this loop + + + align:start position:0% +newton-raphson and when this loop +finishes I reduce some U and it'll just + + align:start position:0% +finishes I reduce some U and it'll just + + + align:start position:0% +finishes I reduce some U and it'll just +use my previous guests as the initial + + align:start position:0% +use my previous guests as the initial + + + align:start position:0% +use my previous guests as the initial +guess for the next value of the loop + + align:start position:0% +guess for the next value of the loop + + + align:start position:0% +guess for the next value of the loop +until mu is sufficiently small okay + + align:start position:0% +until mu is sufficiently small okay + + + align:start position:0% +until mu is sufficiently small okay +interior point method here's what that + + align:start position:0% +interior point method here's what that + + + align:start position:0% +interior point method here's what that +solution path looks like okay so mu + + align:start position:0% +solution path looks like okay so mu + + + align:start position:0% +solution path looks like okay so mu +started at one and the barrier was here + + align:start position:0% +started at one and the barrier was here + + + align:start position:0% +started at one and the barrier was here +was close to the edge of the circle but + + align:start position:0% +was close to the edge of the circle but + + + align:start position:0% +was close to the edge of the circle but +not quite on it but as I reduced Mew + + align:start position:0% +not quite on it but as I reduced Mew + + + align:start position:0% +not quite on it but as I reduced Mew +further and further and further you can + + align:start position:0% +further and further and further you can + + + align:start position:0% +further and further and further you can +see the path the solution path that was + + align:start position:0% +see the path the solution path that was + + + align:start position:0% +see the path the solution path that was +followed works its way closer to the + + align:start position:0% +followed works its way closer to the + + + align:start position:0% +followed works its way closer to the +boundary of the circle and the minimum + + align:start position:0% +boundary of the circle and the minimum + + + align:start position:0% +boundary of the circle and the minimum +is found right here okay so it turns out + + align:start position:0% +is found right here okay so it turns out + + + align:start position:0% +is found right here okay so it turns out +the minimum of this function doesn't + + align:start position:0% +the minimum of this function doesn't + + + align:start position:0% +the minimum of this function doesn't +live in the domain it lives on the + + align:start position:0% +live in the domain it lives on the + + + align:start position:0% +live in the domain it lives on the +boundary of the domain recall that this + + align:start position:0% +boundary of the domain recall that this + + + align:start position:0% +boundary of the domain recall that this +point should be a point where the + + align:start position:0% +point should be a point where the + + + align:start position:0% +point should be a point where the +boundary of the domain is parallel to + + align:start position:0% +boundary of the domain is parallel to + + + align:start position:0% +boundary of the domain is parallel to +the contours of the function right since + + align:start position:0% +the contours of the function right since + + + align:start position:0% +the contours of the function right since +actually we didn't need the inequality + + align:start position:0% +actually we didn't need the inequality + + + align:start position:0% +actually we didn't need the inequality +constraint here we could have used the + + align:start position:0% +constraint here we could have used the + + + align:start position:0% +constraint here we could have used the +Equality constraint the Equality + + align:start position:0% +Equality constraint the Equality + + + align:start position:0% +Equality constraint the Equality +constraint problem has the same solution + + align:start position:0% +constraint problem has the same solution + + + align:start position:0% +constraint problem has the same solution +as the inequality constraint from and + + align:start position:0% +as the inequality constraint from and + + + align:start position:0% +as the inequality constraint from and +look that actually happened right here's + + align:start position:0% +look that actually happened right here's + + + align:start position:0% +look that actually happened right here's +the contours of the function the contour + + align:start position:0% +the contours of the function the contour + + + align:start position:0% +the contours of the function the contour +the function runs right along here and + + align:start position:0% +the function runs right along here and + + + align:start position:0% +the function runs right along here and +you can see it's looks like it's going + + align:start position:0% +you can see it's looks like it's going + + + align:start position:0% +you can see it's looks like it's going +to be tangent to the circle at this + + align:start position:0% +to be tangent to the circle at this + + + align:start position:0% +to be tangent to the circle at this +point so the interior point method + + align:start position:0% +point so the interior point method + + + align:start position:0% +point so the interior point method +actually solved an equality constraint + + align:start position:0% +actually solved an equality constraint + + + align:start position:0% +actually solved an equality constraint +problem in addition to an inequality + + align:start position:0% +problem in addition to an inequality + + + align:start position:0% +problem in addition to an inequality +constraint promises that's that's sort + + align:start position:0% +constraint promises that's that's sort + + + align:start position:0% +constraint promises that's that's sort +of cool that you can do it that way okay + + align:start position:0% +of cool that you can do it that way okay + + + align:start position:0% +of cool that you can do it that way okay +how about if I want to do a combination + + align:start position:0% +how about if I want to do a combination + + + align:start position:0% +how about if I want to do a combination +of equality and inequality constraints + + align:start position:0% +of equality and inequality constraints + + + align:start position:0% +of equality and inequality constraints +then what do I do yeah perfect right + + align:start position:0% +then what do I do yeah perfect right + + + align:start position:0% +then what do I do yeah perfect right +convert the Equality constraint into + + align:start position:0% +convert the Equality constraint into + + + align:start position:0% +convert the Equality constraint into +unknowns Lagrange multipliers instead + + align:start position:0% +unknowns Lagrange multipliers instead + + + align:start position:0% +unknowns Lagrange multipliers instead +right and then do the interior point + + align:start position:0% +right and then do the interior point + + + align:start position:0% +right and then do the interior point +method on the Lagrangian problem okay + + align:start position:0% +method on the Lagrangian problem okay + + + align:start position:0% +method on the Lagrangian problem okay +now you've got a combination of equality + + align:start position:0% +now you've got a combination of equality + + + align:start position:0% +now you've got a combination of equality +and inequality constraint this is + + align:start position:0% +and inequality constraint this is + + + align:start position:0% +and inequality constraint this is +exactly what MATLAB does + + align:start position:0% +exactly what MATLAB does + + + align:start position:0% +exactly what MATLAB does +okay so converts equality constraints + + align:start position:0% +okay so converts equality constraints + + + align:start position:0% +okay so converts equality constraints +into LeGrande multipliers in equality + + align:start position:0% +into LeGrande multipliers in equality + + + align:start position:0% +into LeGrande multipliers in equality +constraints that actually solves using + + align:start position:0% +constraints that actually solves using + + + align:start position:0% +constraints that actually solves using +interior point methods buried in that + + align:start position:0% +interior point methods buried in that + + + align:start position:0% +interior point methods buried in that +interior point method is some form of + + align:start position:0% +interior point method is some form of + + + align:start position:0% +interior point method is some form of +newton-raphson and steepest descent + + align:start position:0% +newton-raphson and steepest descent + + + align:start position:0% +newton-raphson and steepest descent +combined together like dogleg we talked + + align:start position:0% +combined together like dogleg we talked + + + align:start position:0% +combined together like dogleg we talked +about for unconstrained problems and + + align:start position:0% +about for unconstrained problems and + + + align:start position:0% +about for unconstrained problems and +it's going to do a continuation as it + + align:start position:0% +it's going to do a continuation as it + + + align:start position:0% +it's going to do a continuation as it +reduces the values of MU he'll have some + + align:start position:0% +reduces the values of MU he'll have some + + + align:start position:0% +reduces the values of MU he'll have some +heuristic for how it does that right + + align:start position:0% +heuristic for how it does that right + + + align:start position:0% +heuristic for how it does that right +it's going to use its previous solutions + + align:start position:0% +it's going to use its previous solutions + + + align:start position:0% +it's going to use its previous solutions +as initial guesses for the next + + align:start position:0% +as initial guesses for the next + + + align:start position:0% +as initial guesses for the next +iteration so these are very complicated + + align:start position:0% +iteration so these are very complicated + + + align:start position:0% +iteration so these are very complicated +problems but if you understand how to + + align:start position:0% +problems but if you understand how to + + + align:start position:0% +problems but if you understand how to +solve systems of nonlinear equations + + align:start position:0% +solve systems of nonlinear equations + + + align:start position:0% +solve systems of nonlinear equations +okay you think carefully about how to + + align:start position:0% +okay you think carefully about how to + + + align:start position:0% +okay you think carefully about how to +control numerical error in your + + align:start position:0% +control numerical error in your + + + align:start position:0% +control numerical error in your +algorithm you come to conclusion like + + align:start position:0% +algorithm you come to conclusion like + + + align:start position:0% +algorithm you come to conclusion like +this that you can you know you can you + + align:start position:0% +this that you can you know you can you + + + align:start position:0% +this that you can you know you can you +can do these sorts of Lagrange + + align:start position:0% +can do these sorts of Lagrange + + + align:start position:0% +can do these sorts of Lagrange +multiplier interior point methods solve + + align:start position:0% +multiplier interior point methods solve + + + align:start position:0% +multiplier interior point methods solve +a wide variety of problems with + + align:start position:0% +a wide variety of problems with + + + align:start position:0% +a wide variety of problems with +reasonable reliability okay any more + + align:start position:0% +reasonable reliability okay any more + + + align:start position:0% +reasonable reliability okay any more +questions + + align:start position:0% + + + + align:start position:0% + +no good well thank you and we'll see you + + align:start position:0% +no good well thank you and we'll see you + + + align:start position:0% +no good well thank you and we'll see you +on Friday \ No newline at end of file diff --git a/Pij6J0HsYFA.txt b/Pij6J0HsYFA.txt new file mode 100644 index 0000000000000000000000000000000000000000..c1f1dbe93f5b8e317953f44f9de33a2c370faf3a --- /dev/null +++ b/Pij6J0HsYFA.txt @@ -0,0 +1,3074 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help MIT +OpenCourseware continue to + +offer high-quality educational +resources for free. + +To make a donation, or view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseware, at + +ocw.mit.edu. + +PROFESSOR JIM ERICSON: +OK, to work. + +A word of warning: fasten +your seat belts. + +Or, another way of saying it is, +I'm going to open up the + +fire hose a little bit today. + +Last lecture, you might have +thought this was a SHASS + +class, it's not like a +philosophy class, and it was + +important to set the stage for +what we're going to talk + +about, but we talked about +very high level things. + +The notion of recipes, the +notion of computation, why you + +want to do this, what you're +going to learn. + +Today we're going to dive into +the nitty-gritty, the nuts and + +bolts of the basics of +computation, and in + +particular, what I'm going to do +today is, I'm going to talk + +about operators and operands, +which we did a little bit real + +last time, in particular how +to create expressions, I'm + +going to talk about statements +as the key building blocks for + +writing code, and I'm going to +introduce simple sets of + +programs, in particular I'm +going to talk about branching, + +conditionals, and iteration. + +So, a lot to do. + +OK? + +So, let me jump straight +to it. + +At the end of last lecture, we +started introducing some of + +the pieces you want to do. + +And I want to remind +you of our goal. + +We're trying to describe +processes. + +We want to have things that +deduce new kinds of + +information. + +So we want to write programs +to do that. + +If we're going to write +programs, we need at least two + +things: we need some +representation + +for fundamental data. + +And we saw last time two +examples of that. + +And the second thing we're going +to need, is we're going + +to need a way to give +instructions to the computer + +to manipulate that data. + +We need to give it a description +of the recipe. + +In terms of primitive +data, what we saw + +were two kinds: Right? + +Numbers and strings. + +A little later on in the +lecture we're going to + +introduce a third kind of value, +but what we're going to + +see throughout the term is, no +matter how complex a data + +structure we create, and we're +going to create a variety of + +data structures, fundamentally +all of them have their basis, + +their atomic level if you like, +are going to be some + +combinations of numbers, of +strings, and the third type, + +which are booleans, which I'm +going to introduce a little + +later on in this lecture. + +And that kind of makes +sense right? + +Numbers are there to do numeric +things, strings are + +our fundamental way of +representing textual + +information. + +And so we're going to see +how to combine those + +things as we go along. + +Second thing we saw was, we saw +that associated with every + +primitive value was a type. + +And these are kind of +obvious, right? + +Strings are strings. + +For numbers, we had some +variations; we had integers, + +we had floats. + +We'll introduce a few +more as we go along. + +But those types are important, +because they tell us something + +about what we want to do when we +want to put them together. + +OK, but nonetheless, I want to +stress we have both a value, + +yeah, and a type. + +All right. + +Once we have them, we +want to start making + +combinations out of them. + +We want to put pieces +together. + +And for that, we combine +things in expressions. + +And what we saw as expressions +are formed of + +operands and operators. + +And the simple things we did +were the sort of things you'd + +expect from numerical things. + +Now I want to stress one +other nuance here. + +Which is, and we're going to +do some examples of this, + +initially we just typed in +expressions into the + +interpreter; that is, directly +into Python. + +And as I suggested last time, +the interpreter is actually a + +program inside of the machine +that is basically following + +the rules we're describing here +to deduce the value and + +print it up. + +And if we type directly into +the interpreter, it + +essentially does an +eval and a print. + +It evaluates, and it prints. + +Most of the time, we're going to +be doing expressions inside + +of some piece of code, inside +of a script, which is the + +Python word for program. + +In there, I want to make this +distinction, this nuance: the + +evaluator is still going to be +taking those expressions and + +using its rules to get a value, +but it's not going to + +print them back out. + +Why? + +Because typically, you're doing +that to use it somewhere + +else in the program. + +It's going to be stored +away in a variable. + +It's going to be stuck +in a data structure. + +It's going to be used +for a side effect. + +So, inside of code, or inside of +a script, there's no print, + +unless we make it explicit. + +And that's a little bit down in +the weeds, it's a detail, + +but one I want to stress. + +You need to, if you want +something to be printed out + +inside your code, you need to +tell the machine to do that. + +OK. + +So let's do some simple +examples. + +We've already seen somebody's. + +I just want to remind you, if I +wanted to, for example, type + +in an expression like that, +notice the syntactical form, + +it's an expression, a number, +followed by an operand, + +followed by another +expression. + +And of course I get out the +value I'd like there. + +Yes sir. + +Oh, you don't like leaning +that far to the left? + +OK, if you're a Republican I'll +be happy to shift this + +over a little bit. + +Wow, John, I got a laugh +for a political + +joke, I'm in big trouble. + +That better? + +Oh damn, all right, I'll have +to do it even more. + +OK, here we go, here we go, +you see, I'm doing it down + +here, I can't see it, does +that-- ah, I hear his sighs of + +relief, OK, good. + +There we go. + +Better. + +All right. + +One of the other things we +showed last time is that + +operators are overloaded. + +And this is where you heard +John and I disagree. + +I don't happen to like +this, but he + +thinks it's an ok thing. + +In a particular-- if we, whoa, +we don't do that, we do this-- + +that is, give a combination of +a number multiplication in a + +string, this will in fact give +us back a new string with that + +many replicas, if you +like, of the string + +concatenated together. + +All right? + +And if you want to do other +things, for example, we can + +take two strings and add-- +whoops, sorry-- and add them + +together, we will get +out, again, a + +concatenation of that string. + +And these will, we'll let you +work through the variations, + +but these are the simple +expressions we can use. + +Now, sometimes things get +a little interesting. + +All right? + +What's the value of +that expression? + +What do you think should happen +if I evaluate that + +expression? + +Somebody with a hand up, +so I can see it. + +What's going to happen? + +STUDENT: [UNINTELLIGIBLE] + +PROFESSOR JIM ERICSON: +An error? + +Why? + +STUDENT: [UNINTELLIGIBLE] + +PROFESSOR JIM ERICSON: Great. + +OK. + +That means, let's check it. + +It certainly is. + +We bribe people. + +So I, ah, by the way, John's a +Yankees fan, he throws like + +Johnny Damon, I'm a Red Sox fan, +so we'll see if I, how + +about that? + +And I almost hit John along +the way, great. + +My third right, exactly, +what can I say? + +All right, so we're into bribing +you as we go along + +here, and all right? + +You'll be badly overweight +by the end of the term. + +Right, it's a syntactic error, +because it doesn't know how to + +deal with this. + +But there's an important thing +going on here, if I in fact + +wanted to combine those into a +string, I should have told the + +machine to do that, and I can do +that, by explicitly saying, + +take that, which is a number, +and convert it into a string, + +and then-- bleah, I keep +doing that-- then + +add it to that string. + +OK, so there's an important +point here. + +We've got what's called +type conversion. + +That is, if I want to combine +two things together in a + +particular way, I need to make +sure that I give it the kind + +of operand it expects. + +So STR, which I just typed up +there, takes in parens, some + +input, and it converts it into +a string, so that now I can + +use that where I was +expecting a string. + +John. + +PROFESSOR JOHN GUTTAG: You've +got a static semantic error in + +your syntax. + +PROFESSOR JIM ERICSON: +Thank you. + +And I was going to come to that +in a second, but thank + +you, John, for pointing it out. + +All right. + +Why is it a static +semantic error? + +The syntax is OK in the sense +of, it is an operand, an + +operator, an operand, so +syntactically it's OK. + +The semantics was what caused +the problem, because the + +operator was expecting +a particular kind + +of structure there. + +There's a second thing going +on here that I want to + +highlight, because it's +really important. + +Yes indeed. + +OK, there we go. + +The second thing I want to +highlight is, that what's + +going on, is that Python is +doing some type checking. + +It caught the error, because +it checked the types of the + +operands before it applied +things, and it says, + +I'm going to stop. + +Now, you might have said, gee, +why didn't it just assume that + +I wanted to in fact treat these +as strings, and combine + +them together? + +Sounds like a reasonable +thing to do. + +But it's a dangerous thing. + +Because in doing that, Python +would then have a value that + +it could pass on into some other +part of a computation, + +and if it wasn't what I wanted, +I might be a long ways + +downstream in the computation +before I actually hit some + +result that makes no sense. + +And tracing back where it came +from can be really hard. + +So I actually want to have +type checking as much + +as I can early on. + +And in fact, under type +checking, different languages + +sometimes fall on a spectrum +from weak to strong typing. + +Which basically says, how much +type checking do they do? + +Now, you're going to hear John +and I go back and forth a lot, + +as I said I'm an old time-- well +I'm certainly old time, + +but I'm also an old time +Lisp programmer. + +I love Lisp, but Lisp is +certainly in the category of a + +very weakly typed language. + +It does not check the types +of its arguments at all. + +Python is, I wouldn't say +completely strong, but it's + +much closer to the strong +end of the spectrum. + +It's going to do a lot of type +checking for you before it + +actually passes things back. + +Nonetheless, I'm also going to +argue that it's probably not + +as strongly typed as +we might like. + +So, for example, there's +an expression. + +Now, less than is just, if you +haven't used it before, it's + +just the operator you'd expect, +it's comparing two + +things and it's going to return +either true or false + +depending on whether the first +argument is less than the + +second argument. + +What's going to happen here? + +Again, I need a hand so I can +know where to throw candy. + +I've also got on my +reading glasses + +on, I can't see anything. + +Anybody. + +TAs don't count, they +get their own candy. + +When it, yep. + +STUDENT: [INAUDIBLE] + +PROFESSOR JIM ERICSON: +Good question. + +Sounds like a reasonable +guess, right? + +How in the world am I going to +compare a string to a number? + +So, see how good my aim +is, ah, not bad. + +All right. + +A good quest-- sorry, a +good thought, but in + +fact, son of a gun. + +Or as my younger son would +say, fudge knuckle. + +Yeah. + +All right? + +So, what in the world's +going on here? + +This is a place-- + +I don't know about you, John, +I think this is actually + +really not good, because right, +what this is doing is, + +it's allowing-- sorry, let me +back up and say it-- it's got + +an overload on the less-than +that allows you to compare + +basically the lexicographic +ordering, or this sequence of + +ordering of symbols, including +numbers inside of the machine. + +And this, in my mind, should +have been an error. + +Why in the world would you +want to compare that? + +Just to give you an example of +that, for instance, I can do + +the following: all right, the +number four is less than the + +string three, whereas the string +four, oops, is not less + +than the string three. + +And this is a place where it's +comparing strings and numbers + +in a strange way. + +So why am I showing you this? + +Partly to show you that it's +kind of weird, but also to + +tell you that one of the things +you want to do is + +exercise what I'm going to call +some type discipline. + +Meaning, when you write code, +you want to get into the habit + +of A, checking out operators or +procedures to see what they + +do under different +circumstances, either check + +them out or read the +specifications of it, and two, + +when you write your own code, +you want to be disciplined + +about what types of arguments +or operands + +you apply to operators. + +Because this is something that +could certainly have screwed + +you up if you didn't realize +it did it, and you need to + +have that discipline +to make sure it's + +doing the right thing. + +OK. + +One of the other things you're +going to see is that some of + +the operators have +odd meanings. + +And again, I think we looked-- + +Yup? + +STUDENT: So, the string A is +less than three, is false + +because they're comparing +like ASCII values? + +PROFESSOR JIM ERICSON: Yes. + +I mean, I'm sorry. + +The answer is, I don't +know if it's ASCII. + +John, do you know, are +they doing ASCII + +encoding inside of here? + +I'm assuming so. + +Right. + +So, in case you didn't +understand what the the + +question was, basically every +symbol gets translated into a + +particular encoding, a string +of bit, if you like, inside + +the machine, there's a +particular one called ASCII, + +which is, if you like, an +ordering of that, and that's + +what the machine's actually +comparing inside of here, + +which is why in under ASCII +encoding the numbers are going + +to appear after the characters, +and you get the + +strange kind of thing going on. + +All right. + +I want a couple of other things, +just to quickly remind + +you, and one of them is, +remember, the operators do + +look at the types, so division, +for example nine + +divided by five is one, because +this is integer + +division, that is, it's the +largest number of integer + +multiples of five to go into +nine, and there would be a + +remainder associated with it, +which is in fact four. + +And again, you've got +to be careful about + +how you use the operators. + +Right, having done that, we +can certainly get to more + +complicated things, so for +example, suppose I look at + +that expression. + +Three plus four times five. + +All right. + +Now. + +There are two possible +values here, I think. + +One is 23, the other's 35. + +Because this could be three plus +four, times five, or it + +could be three, plus +four times five. + +And of course, you know, when +you look at code it doesn't + +pause in between them. + +But what I do? + +I just separated, do I do the +addition first or do the + +multiplication first? + +Anybody know what happens +In this case? + +Yeah, way up, oh God I'm going +to have a hell of time + +throwing up there, way +up at the back. + +STUDENT: Standard order of +operations, I guess take the + +multiplication first, +and add the three. + +PROFESSOR JIM ERICSON: Right. + +I'm going to try, if I don't +make it, you know, just get + +somebody to pass back, whoa! + +I just hit somebody +in the head. + +Thank you. + +Please pass it back +to that guy. + +If you want candy, sit much +closer down, and that way we + +can film you as well +as we go along. + +Right. + +So the point is, there is +something here called operator + +precedence, which is what +the gentleman said. + +I'm not going to say much more +about it, but basically what + +it says is, with all other +things being equal, things + +like exponentiation are done +before you do multiplication + +or division, which are done +before you do things like + +addition and subtraction. + +And so, in fact, if I wanted +the other version of it, in + +fact, if I do this right, it's +going to give me 23 because it + +does the multiplication first, +if I wanted the other version + +of it, I need to tell it that, +by using, excuse me, + +parentheses. + +And in general, what I +would say is, when + +in doubt, use parens. + +OK. + +Now, that just gives +us expressions. + +We can start having complex +expressions, you can imagine + +we can have things are lots of +parens, and all sorts of + +things in it. + +Yes, question. + +STUDENT: What does it mean, the +operator used, when you + +were calculating the remainder +between nine and five? + +PROFESSOR JIM ERICSON: It's +the percent sign. + +If you can't read it, I guess +I'm going to have to blow that + +font up, aren't I, +next time around. + +Yeah, it's a percent, so +this percent sign will + +give you the remainder. + +OK. + +Second thing I need to do, +though, is I need to, when I + +get those values, I want +to hang on to them. + +I'd like to give them a name, +so I can refer to them in + +other places. + +And so we saw that as well, the +last piece we had here is + +the ability to create variables, +which have their + +own values, and that's done +using an assignment statement. + +So in particular, that is +an assignment statement. + +It says, take the name x and +create a binding for that name + +to the value of the +sub-expression and in fact to + +do this, to stress a point, +let's do that. + +It's not just a number, +it's any expression. + +What Python will do, is it will +evaluate that expression + +using the kinds of rules we +talked about, and then it + +creates a binding for +x to that value. + +And I want to stress this, we're +going to come back to it + +later on in the term, so the +way I'd like you to think + +about it for now, is that +somewhere in the machine, + +there's a big space that +contains all possible values. + +Right. + +It's a slight lie, it doesn't +have all possible values, but + +you get the idea. + +It has, if you like, +intellectually, + +all possible values. + +And when I create a binding, I'm +taking a variable name, in + +this case x, stored somewhere in +a table, and I'm creating a + +link or a pointer from that +name to that value. + +This is a nuance. + +It's going to make a lot more +sense later on when we + +introduce mutation into our +language, but I want you to + +start thinking of it that way. + +Don't think of it as a specific +box into which we're + +putting things; think of it +as a link to a value. + +I could have, for example, +another assignment statement, + +and that creates a binding from +y into that same value, + +and one of the things as a +conservist I can do is, I + +could have a statement like, +let z be bound to + +the value of x. + +And I said it deliberately +that way. + +That statement says, get the +value of x, which is this + +link, and give z a pointer +to the same place. + +To the value, not to x. + +OK, and we'll just plant that +idea, we're going to come back + +to later on, as we carry on. + +OK. + +So if we have variables, one +of the questions we can ask + +is, what's the type +of the variable. + +And the answer is, it inherits +it from its value. + +OK. + +Yes. + +So if somewhere in my code, I +have that statement, that + +assignment statement, +x now is a variable + +whose value is an integer. + +Unfortunately, at least in +my mind, in Python, these + +variable bindings are +dynamic, or the + +type, rather, is dynamic. + +Meaning, it changes depending on +what the current value is. + +Or said a different way, if +somewhere later on in the + +program I do this, x +now has changed its + +type from INT to string. + +Now why should you care? + +OK, my view is, I +don't like it. + +Especially in the presence +of operator overload. + +Because I might have written +some code in which I'm + +expecting that particular +variable to + +have an integer value. + +If somewhere later on in the +code it shifts to string, I + +might not be manipulating that +and getting actual values out, + +but not what I wanted, and it's +going to be really hard + +for me to chase it back. + +So one of the things I would +like to suggest is that you + +develop some good style here, +and in particular, don't + +change types arbitrarily. + +I can't spell today. + +Meaning, sometimes you need +to do this, but in general + +there's-- at least in my view +and I don't, John, would you + +agree?-- you just don't +want to do this. + +You don't want to make +those changes. + +It just leads to trouble +down the road. + +OK. + +Now, last thing about variables, +and then we're + +going to start pushing +on this, is + +where can you use them? + +And the answer is, you can use +a variable anywhere you can + +use the value. + +So, any place it's legal +to use the value. + +OK. + +Now. + +This is just sort of bringing us +back up to speed and adding + +a few more details in. + +What we really want to +do now though is + +start using this stuff. + +So, operands. + +Let us take expressions, get +values out, we can store them + +away in places, but ultimately +we want to do something with + +them, so we need to now start +talking about what are the + +things we can do inside of +Python, or any programming + +language, to manipulate them. + +And for that, we're going +to have statements. + +Statements are basically, if +you want to think about it, + +legal, and I was about to use +the word expression except + +I've misused that elsewhere, so +legal commands that Python + +can interpret. + +You've already seen +a couple of them. + +Print, assignment, certainly +two obvious statements, + +they're commands to +do something. + +Assignment is binding a name +to a value, print is saying + +put it back out in the screen. + +Obviously if you have print as +a way of putting things out, + +we expect to have ways of +getting input in, we're going + +to see an example that +in the second. + +And as we go through the next +few lectures, we're going to + +add in more and more of +these statements. + +But let's look at what we +could do with this, OK? + +And to do this, I'm going to +use some code that I've + +already typed in. + +So I'm hoping you can +read that, and it's + +also in your handout. + +This is a little file I created, +all right, and I'm + +going to start with a sequence +of these things and walk them + +along, again I invite you to put +comments on that handout + +so that you can follow what +we're going to do. + +All right? + +So let's look at the +first part of this. + +Right now, this is +just a text file. + +OK. + +And I've highlighted in blue up +there one of the pieces I'm + +going to start with. + +And what do I have? + +I have a sequence of commands; +I've got an assignment + +statement, I've got another +assignment statement, I've got + +a print statement, I've got an +input statement, which we'll + +come back to in a second. + +And I want to basically try +and use these things to do + +something with them. + +Second thing I want to note is, +the little hash mark or + +the pound sign, that's +identifying a comment. + +So what's a comment? + +It's words to you, or to the +reader of the code, that are + +telling you what's going +on inside of this code. + +OK? + +Now, these comments, frankly, +are brain-damaged, or + +computationally challenged +if you prefer. + +Meaning, why in the world do I +have to tell the reader that + +I'm binding x to the +value three? + +All right? + +I'm putting them in there +to make a point. + +In general, good programming +style says you put in comments + +that are going to be valuable +in helping you as a reader + +understand what's going +on inside of the code. + +It could be, what's the +intuition behind + +this piece of code. + +It could be, preconditions +I want to have on input. + +It could be, explanations of +specific things you're doing. + +But you need to have those +comments there. + +Now, this becomes a little bit +of one of those motherhood and + +apple pie kinds of lectures. + +You know, your mother always +told you to eat brussels + +sprouts because it +was good for you. + +Well this is a brussels sprouts +comment. everybody + +goes yeah, yeah, yeah, +comments, of course. + +Of course we're going +to do comments. + +And they never do. + +So my challenge to you, and I +know Professor Guttag can do + +this, my challenge to you is, a +year from now, come back and + +look at code you wrote here. + +Can you still understand what it +was you were trying to do? + +I don't know, John, if +you'd agree, right? + +If you can read the code a +year later, even code you + +wrote yourself, it's a good +sign that you put good + +comments in, right? + +Second good piece +of style here is + +choice of variable names. + +These are lousy. + +Deliberately. + +OK? + +I'm just using simple things +like x and y and z because I + +want to make it, just +get through the + +lecture if you like. + +But in general, the choice of +variable name is a great way + +of commenting your code. + +Use variable names +that make sense. + +That little problem set +zero that you did. + +You read in a couple +of values, you + +probably stored them away. + +My bet is, you used simple +names like x and y. + +A much better name would have +been firstname, lastname, as + +the name of the variable to tell +you what you were trying + +to capture there. + +OK. + +The other piece I want to say +about variable names is, once + +I have that choice of variable +name, I can use it, but in + +fact there are a few things that +I can't use in terms of + +variable names. + +So, these are an important way +of documenting, but there're + +some things excluded. + +And in particular, there are +some key words that Python is + +going to use that have +to be excluded. + +Let me highlight that. + +As I said, right now that's +just text file. + +I'm going to save this away-- +yeah, not that way, I'm going + +to save this away-- with the +subscript, or the suffix + +rather, py to make +it a Python file. + +Yeah, and I know it's already +there but I'm going to do it, + +and I get some wonderful +colors. + +But these are important, OK? + +So notice what I have +up there now. + +Comments appear in red. + +I can see those. + +There's a keyword, which I'm +going to highlight right up + +here, print, which is in, +I don't know what + +that color is, orange? + +There's a function in purple, +there's a string in green, and + +in black I have the assignment +statements. + +That print is a keyword. + +It's a command to Python +to do something. + +As a consequence, I can't use +it as a variable name. + +All right, think about +it for a second. + +If I wanted to use print as a +variable name, how do I get + +the system to decide gee, do +I want print as a value for + +something, or do I want +print as a command? + +So there's a sequence of these +that are blocked out, and I-- + +John, I think there are +what, twenty-eight? + +Something like that, +TAs, is that right? + +Twenty-eight keywords +that are blocked? + +We'll find them as +we go along-- + +OK. + +Having done this now, I can +simply go ahead and run this, + +and in fact if I go up here to +run, you'll see I've got both + +an option to check the module, +though in this case I'm just + +going to run it. + +Oh, notice what happened. + +It ran through that sequence of +instructions, in particular + +it bound x to the value three, +and then it took x times x, + +got the value of x multipied by +x, which of course is nine, + +bound that to the value of x, +and then it printed out the + +value, and now it's sitting +here waiting for an input. + +You notice what it did, it +printed out that little, right + +up here I'd said enter a number +and that's what it's + +printed out, so I can enter a +number and it prints it out. + +Great. + +Let's run it again. + +Actually for that, I can just +use, if I'm lucky, function + +F5, which didn't work, so let me +try it again., here we go. + +We're going to run that module. + +OK. + +Whoa. + +What happened? + +I said enter a number. + +I didn't. + +I gave it a string. + +And it still took it. + +And printed it up. + +Well, this is one of the places +where I want to come + +back to that highlighting +of what do things do? + +Even though my statement said +enter a number, in particular, + +raw input here simply takes in a +set of characters and treats + +it as a string. + +And then prints it back out. + +So if in fact I wanted to make +sure this was a number, I + +should have done something like +either try and convert it + +to a number, which of course +failed here, or put in a check + +to say where it is. + +So it's a way of reminding you, +I've got to be careful + +about the types of things +that I put in. + +OK. + +This is still boring, so let's +step on the accelerator. + +What I have now is the +following: I can write + +expressions, do combinations of +things to get out values, I + +can store them away, I +can print them up. + +But literally all I can do at +this stage is write what we + +would call a straight-line +program, that is, a program in + +which we execute in which we +execute the sequence of + +instructions one by one. + +Simply walk down that +list. That's what we + +just did there, right? + +We just walked through that +list. This is boring. + +In fact, you can do some nice +things to prove what is the + +class of functions you can +compute with straight-line + +programs, and what you'd see if +you did that is, it's not + +particularly interesting. + +OK. + +Let's go back and think +about our recipes. + +What we use as our +motivation here. + +Even in real recipes, you +have things like, + +if needed, add sugar. + +That's a decision. + +That's a conditional. + +That's a branch. + +That says, if something +is true, do something. + +Otherwise, do something +different. + +So to really add to this, we +need to have branching + +programs. What I mean by that +is, a branching program is + +something that can change the +order of instructions based on + +some test. And that test is +usually a value of a variable. + +OK. + +And these get a whole lot +more interesting. + +So let's look at a little +example, and this is going to, + +excuse me, both allow us +introduce the syntax as well + +as what we want to have +as the flow of + +control inside of here. + +So let me go back up here, and +I'm going to comment out that + +region, and let's uncomment +this region. + +I want to write a little +piece of code. + +It's going to print out even or +odd, depending on whether + +the value I put in, which is x +in this case, is even or odd. + +Think about that. + +That says, if this thing has +some particular value, I want + +to do one thing; otherwise, +I want to + +do something different. + +And let's look at the +syntax of this. + +This is the first of the +conditionals that + +we're going to see. + +Notice the format. + +I'm going to go up there. + +The first statement right +here, that's just an + +assignment statement, I'm +giving some value to x. + +We could make it something +different. + +And then, notice the +structure here. + +The next three statements. + +First of all, IF is a keyword. +which makes sense. + +It is followed, as you can see +there, by some expression, + +followed by a colon. + +And in fact, that colon is +important, so let me stress + +this over here. + +The colon is important It's +defining the beginning of a + +block of instructions. + +Yes sir. + +STUDENT: [UNINTELLIGIBLE] + +PROFESSOR JIM ERICSON: Based on +a test. Usually the value + +of a variable. + +OK, so let me go back +to where I am. + +I'm looking at that +piece of code. + +What that colon is saying is, +I'm about to begin a sequence + +of instructions that I want +to treat as a block. + +So it identifies a block +of instructions. + +It's, and in particular, the +colon is the start, and the + +carriage return is the end. + +Now what in the world +does that mean? + +I'm doing a lot of words here, +let me try and say this a + +little bit better. + +That code says the following: +the IF says, I've got an + +expression, I'm going +to evaluate it. + +If that value is true, I want +to do a set of things. + +And that set of things is +identified by the sequence of + +commands that are indented in, +this one right here, following + +the colon but before I get +back to the same place in + +terms of the indentation. + +If that test is not true, I want +to skip this instruction, + +and there's a second keyword +else, followed by a colon, and + +that tells me the thing +I want to do in the + +case that it's false. + +So in fact if I run this, +ah, and save it, and + +it prints out odd. + +So, what happened here? + +Well, let's look at the code. + +Right? x is initially +bound to fifteen. + +I get to the IF. + +The IF says, evaluate that +next expression. + +In that next expression, I'm +actually taking advantage of + +the fact that I'm doing integer +multiplication and + +division here. + +Right, that divide is, if x is +an integer and two is an + +integer, what's it +going to do? + +If x was even, x divided by two +is going to be actually + +the half of x, right? + +If x is odd, that integer +division is going to give me + +the number of multiples of two, +that go into x, plus a + +remainder, which I'm going +to throw away. + +In either case, I take that +value and multiply back by + +two, if it was even I get back +the original number, if it was + +odd, I'm not going to get back +the original number, so I can + +just check to see if +they're the same. + +OK, so a little nuance +that I'm using there. + +So, the first thing that IF +does, bleah that IF says is, + +evaluate that expression and +if it's true, do the next + +thing, the thing after +the colon. + +In this case it's not true, so +it's going to skip down and + +evaluate the thing printed +up the odd. + +OK. + +What-- yes. + +STUDENT: [INAUDIBLE] + +PROFESSOR JIM ERICSON: +Thank you. + +I was hoping somebody would +ask that question. + +The question was, if you didn't +hear, why do I have two + +equal signs? + +It's like I'm doing +this, right? + +Anybody have a se--%uFFFD +why don't I just + +use an equal sign? + +I want to know if something's +equal to something. + +Yeah. + +STUDENT: [INAUDIBLE] + +PROFESSOR JIM ERICSON: +Absolutely. + +The equal sign is +going to bind-- + +Nice catch. + +John, this is so much +fun, throwing candy. + +I've got to say, we've got +to do this more often-- + +Right. + +Let me, let me get +to the point. + +What does an equal sign do? + +It is an assignment. + +It says, take this thing on the +left and use it as a name + +to bind to the value +on the right. + +It's not what I want here. + +Having already chosen to use +equal as an assignment, I need + +something else to +do comparison. + +And that's why I use +double equals. + +Those two equal signs are +saying, is this thing equal + +to, in value, the thing +on the other side? + +OK. + +Now, having done that, again I +want to stress this idea and + +I'm going to write it out one +more time, that there's a + +particular format here. + +So we have if, and that is +followed by, I'm going to use + +angle braces here just to +indicates something goes in + +here, some test followed +by a colon. + +That is followed by a block +of instructions. + +And we have an ELSE, followed by +a colon in some other block + +of instructions. + +And I want you to get used to +this, that colon is important, + +it identifies the start, and +then the set of indented + +things identify all the things +at the same level, and when we + +reset back to the previous +level, that's when we go back + +to where we were. + +OK. + +Now, that's a nice simple little +test, let's look at a + +couple of other examples +to get a sense of + +what this will do. + +OK, let me comment this out, +and let's look at this next + +little piece of code. + +All right. + +I'm binding a z to be some +value, and then I'm + +going to run this. + +Well, let's just run it +and see what it does. + +Nothing. + +OK, so why? + +Well, let's look at it. + +I'm doing a test there to say, +if the string x is less than + +the value of b, and x does not +appear before b as strings, + +then I was going to do, oh, a +couple of things, because + +they're at the same +block level. + +Given that that wasn't +true, it did nothing. + +Now, wait a minute, you say, +where's the ELSE clause? + +And the answer is, +I don't need one. + +All right, if this is purely a +test of, if this is true do + +this otherwise I don't care, I +don't need the ELSE clause in + +there to identify it. + +All right? + +Second thing I want to look at +is, suppose I compare that the + +one below it. + +Oops, that I don't want to do. + +Comment that out, and let's +uncomment this. + +Yeah, I've still got a binding +for z and I'm giving it the + +same test, but notice now I've +got the two same commands but + +they have different +indentation. + +In this case, in fact I do +get a different behavior. + +Why? + +Because that block identifies a +set of things that I'm going + +to do if the test is true. + +If the test was not true, notice +that that last command + +for print Mon is now back at the +same level as the IF, so + +what this says is the IF does +the test, having done the + +test, it decides I'm not going +to do anything in the block + +below it, I'm going to skip +down therefore to the next + +instruction at the same level +as the IF, which gets me to + +the second print statement. + +OK. + +So now we're seeing some of +these variations, let's see + +what else can we do here. + +So let me just to try something +a little more + +interesting, and then we'll +get to writing some simple + +programs. So I'm going to +comment those out, and let's + +go down to this piece of +code, and uncomment it. + +Ooh yes, that was brilliant. + +Let's try this again. + +And uncomment that, and +uncomment it again. + +Right, so here's a little piece +of code that's going to + +print out the smallest +value of three. + +And notice what this +is showing is that + +the IFs can be nested. + +All right, it's so if I looked +at it, it's going to say that + +IF x is y-- sorry, IF x is less +than y, THEN check to see + +IF x is less than z, and if +that's true, print out x is + +the smallest. And notice the +structure of it, if it's not + +true I'm going to go to that +next ELSE, and print out that + +z is smallest. If the first test +wasn't true, I'm going to + +skip that whole block and just +go down and print out that y + +was smallest. So notice the +nesting, I can flow my way + +through how those tests are +actually going to take place. + +All right, so let's run this +and see what happens. + +Great. y is smallest. OK. + +Is that code correct? + +Is that a tentative +hand back there? + +Yeah. + +STUDENT: Let me compare +y to [INAUDIBLE] + +PROFESSOR JIM ERICSON: Yeah, +it's not doing all of the + +comparisons. + +All right, and let's just check +this out, because I want + +to make a point of this, let's +go back and do the following. + +Let's take y, change it to +thirteen, let's run it, hmm. + +So what did I miss here? + +Two important points. + +First one, when I write a piece +of code, especially code + +that has branches in it, when +I design test cases for that + +piece of code, I should try and +have a specific test case + +for each possible path +through the code. + +And by just doing that, I just +spotted, there's a bug here. + +And the bug was in my thinking, +I did not look for + +all of the tests. + +So the way I can fix that, is, +let me comment that out, and + +keep doing that, comment that +out, let's uncomment this, + +notice the structure here. + +I now have multiple tests. + +So actually, let's just run +it and then we'll talk + +about what it does. + +I run this, yeah, I have a +syntax error, yes indeed, + +because I forgot to comment that +one out, all right, and + +cue, we'll try it again. + +Ah-ha! + +And let's quickly look at +the structure of this. + +This now has, gee, a funny +thing, it says IF x is less + +than y AND x is less than +z, then do something. + +And then it has a strange thing +called ELIF, which is + +simply short for else/if in a +second test. So the way to + +think about this in terms of +flow is, it starts with that + +if and it says, check both +of those things. + +And that fact that both of those +things is the fact that + +we're using Boolean +combination here. + +It is to say, we can take any +logical expressions, combine + +them together with AND, OR, +or NOT to make a complex + +expression, and use the value of +that expression as my test. + +And that's literally what I've +done there, right, I've got x + +less than y, that's a test, it +returns a Boolean, which by + +the way is the other type, at +least I would include here, it + +has only two values, which are +true and false, and what that + +code says, if x is less than y, +AND, logically, whatever I + +put up there, x is less than +z, then the combination is + +true, and therefore I'm +going to do something. + +So AND is if both arguments are +true it's true, OR is if + +either argument it's true it's +true, NOT is if the argument + +is not true it's true, and then +the last piece, as I said + +is, I can now have a sequence +of things I want to do. + +So if this is true do something +else, otherwise test + +and see if this is true, do +something else, as many as I + +like followed by the end. + +And ELSE, it says, here's +what I want to do. + +OK. + +Now. + +Having added this in, I have +branching instructions. + +I have simple branching +programs. These are still + +awfully simple. + +OK? + +And they're awfully simple +because, all I can do now, is + +decide whether to execute some +piece of code or another. + +Said a different way, in the +case of the straight-line + +programs, how long would it +take to run a program? + +Well, basically, however many +instructions I have, because + +I've got to do each +one in order. + +With simple branching, how long +is it going to take to + +run a piece of code? + +Well at most, I'm going to +execute each instruction once. + +All right? + +Because the IFs are saying, if +it's true do this, otherwise + +skip on it. + +Therefore, for simple branching +programs, the length + +of time, the complexity +the code, is what + +we would call constant. + +That is, it's at most the length +of the actual number of + +instructions. + +It doesn't depend +on the input. + +Real simple programs. + +Let's take another +simple example. + +Suppose I want to compute +the average age + +of all the MIT faculty. + +There's about a thousand +of us. + +However I do that, I know that +should inherently take more + +time than it takes to compute +the average age of all the + +EECS faculty. + +There's only 125 of us. + +And that should take more time +than what it takes to compute + +the average of John's and my +ages, instructors in 600, + +because there's only +two of us. + +All right, those pieces of +code inherently involved + +something that does depend on +the size of the input, or on + +the particular input. + +And that is a preface to an +idea of computational + +complexity we're going +to come back to. + +One of the things we want to +help you do is identify the + +different classes of algorithms, +what their costs + +are, and how you can map +problems into the most + +efficient class to do +the computation. + +OK. + +Now. + +Think for a second about +computing the average age of + +the faculty. + +You can already kind of +see what I want to do. + +I, somehow if, I want to walk +through some sequence of data + +structures, gathering up or +doing the same thing, adding + +ages in until I get a total +age and then divide by the + +number faculty. + +How do I write a piece +of code for that? + +Well, let's go back +up to our original + +starting point of recipes. + +And I'm sure you don't remember, +but one of the + +things I had in my recipe, is +beat egg whites until stiff. + +OK. + +That until is an +important word. + +It's actually defining a test. +Let me rephrase it into + +garbled English that'll lead +more naturally into what I + +want to do. + +While the egg whites are +not stiff, beat them. + +That is a different +kind of structure. + +It has a test in it, which is +that while, while something is + +true, do something, but I +want to keep doing it. + +And so for that, we need +to add one last thing. + +Which is iteration. + +Or loops. + +We're going to see variations of +this, we're going to see a + +variation of it called +recursion, a little later on, + +but for now we're just going +to talk about how do we do + +iterations. + +And I want to show you an +example of this, to lead to + +both the syntax, and +to the semantics. + +And let me comment that out, +and let's go to this one. + +All right. + +What does this piece +of code say? + +Not, what does it do, but +what does it say. + +Well, the first three statements +are just assignment + +statements. + +I'm binding x, y, and iters +left to some values. + +And then notice the structure, I +got a keyword WHILE, there's + +that color identifying it, and +in parentheses I have a test. + +I'm expecting the value that +test to be a Boolean. + +Followed by a colon. + +The colon's identifying +a block of code. + +And what this is +saying is, gee. + +Check to see if the variable +iters left has a value + +greater than zero. + +If it does, then execute +each of the + +instructions in that block. + +So I'm going to have an +assignment of y, I'm going to + +have an assignment of iters +left, I've got a comment that + +I had borrowed in order to do +some debugging, and then what + +do I want it to do? + +I want it to go back around to +the test. Once again, say, is + +that test true? + +If it is true, execute the +sequence of instructions. + +So in fact we can block this +out and see what it does. + +If I make a little chart here, +I've got x, y, and iters left. + +x starts off as I think I set +it up as, here I can't even + +read it, is x is three, y is +zero, iters left is three. + +I can hand-simulate it. + +It says, is the value of iters +left greater than zero? + +Yes it is. + +So, execute those two +instructions. + +It says, take value of y and +value of x, add them together, + +and create that as the +new value of y. + +All right. + +That's the assigned statement. + +It says, take iters left, +subtract one from it, and bind + +that as the new value +of iters left. + +Having reached the end of the +block, go back up and check + +the test. Is iters left +greater than zero? + +Yes it is. + +So, evaluate the same sequence +of instructions again. y plus + +x is six, that's my new value +of y, two minus one is one, + +that's my new value of iters +left, go back up. + +Is iters left greater +than zero? + +Yes it is. + +So once more, thank God I didn't +take 47 as an example, + +x plus y, subtract one from +iters left, go back up to the + +test. Is iters left's value +greater than zero? + +No, it is not. + +Therefore, skip the rest of that +block of code and go to + +the next instruction, which +is, ah, print out y. + +In fact, if we test this, +son of a gun. + +Got a simple square +procedure,. + +Right, It's just squaring an +integer, is what it's doing. + +But notice the structure. + +Now I have the ability to create +a loop, that is, to + +reuse the same pieces of +code over and over + +again as I go around. + +And this adds, now, a lot +of power to the kinds + +of code I can write. + +Notice some other things I want +to highlight on this. + +All right? + +The first one is, that test +has to involve-- shouldn't + +have to, but almost always is +going to involve-- the value + +of some variable. + +What if I don't change the value +of that variable inside + +of the code? + +Or, another way of saying it +is, what if I did this? + +Comment it up. + +What happens if I +run this sucker? + +STUDENT: [INAUDIBLE] + +PROFESSOR JIM ERICSON: Yeah. + +It'll go forever. + +Absolutely, right? + +It's going to loop into +an infinite loop-- + +I think I can hit this close, +ah, no I can't, boy what a + +terrible aim-- + +All right, what has +[UNINTELLIGIBLE PHRASE] try + +again, the point I'm trying to +make here-- thank God we're at + +the end of this lecture, my +tongue is falling apart-- the + +point I'm trying to make is, +that test needs to involve + +some loop variable +that is changing. + +Otherwise the test is always +going to be true, we're going + +to go off here, but this would +loop forever if I did that. + +All right. + +Second question: or maybe a +better way of saying this, and + +the general format you're likely +to see here is, a test + +involving a variable name, +which must be initialized + +outside of the loop, and which +interior to the loop gets + +changed, so that the test +is going to change. + +Here's the second question. + +What value of inputs, what +values of x will this run + +correctly for? + +Probably should be +integers, right? + +Otherwise, this is going to be +doing something strange, but + +all integers? + +All right, suppose I do this. + +It's my last example. + +Yeah, how about that, right? + +We knew this was trying to do +squaring, so intellectually we + +know we can square -4, it +ought to be 16, but what + +happens here? + +Double fudge knuckle. + +All right? + +It's going to run through the +loop, accumulating the + +answers, but because I'm +subtracting, it's just going + +to keep making x more and more +negative as it goes along, + +again it's off into +an infinite loop. + +Which is a way of reminding you +that I need to think as I + +write the code about what are +my expectations from the + +input, and how might +I enforce them. + +In this case, I probably want +to make sure I use absolute + +value of x before +I carry it on. + +Yes ma'am. + +STUDENT: [UNINTELLIGIBLE] + +PROFESSOR JIM ERICSON: You're +absolutely right, because I + +bind iters left to, um, yeah. + +Yes. + +Thank you. + +Boy, two candy for you. + +You caught me making an error. + +Yes. + +The point is, it's not going to +work, and she caught both + +of them, impressive, it's not +going to work because iters + +left is already negative, it's +just going to skip the whole + +loop, and I'm in trouble, so +thank you for catching that. + +All right. + +I was going to do one more +example, but I've run you up + +to the end of the time. + +I'll leave the example on the +handout, it shows you another + +version that we'll come +back to next time. + +The key thing to notice is, I +now have the ability to create + +iterations, which extends +well I can do. + +And we'll see you next time. \ No newline at end of file diff --git a/Q2uUFNDuRFk.txt b/Q2uUFNDuRFk.txt new file mode 100644 index 0000000000000000000000000000000000000000..592d8d15d2e7551fbf07ed8c18d8784eca4228b3 --- /dev/null +++ b/Q2uUFNDuRFk.txt @@ -0,0 +1,387 @@ +align:start position:0% + +so it was very I'll say crucial for me + + align:start position:0% +so it was very I'll say crucial for me + + + align:start position:0% +so it was very I'll say crucial for me +to do this interview in both English and + + align:start position:0% +to do this interview in both English and + + + align:start position:0% +to do this interview in both English and +Creole because I see Creole languages + + align:start position:0% +Creole because I see Creole languages + + + align:start position:0% +Creole because I see Creole languages +like even in the case of Haiti + + align:start position:0% +like even in the case of Haiti + + + align:start position:0% +like even in the case of Haiti +especially because of Haiti as a + + align:start position:0% +especially because of Haiti as a + + + align:start position:0% +especially because of Haiti as a +particular revealing and clear test tube + + align:start position:0% +particular revealing and clear test tube + + + align:start position:0% +particular revealing and clear test tube +or key study to really show how language + + align:start position:0% +or key study to really show how language + + + align:start position:0% +or key study to really show how language +can be such a powerful tool either for + + align:start position:0% +can be such a powerful tool either for + + + align:start position:0% +can be such a powerful tool either for +illumination or for resistance either + + align:start position:0% +illumination or for resistance either + + + align:start position:0% +illumination or for resistance either +for oppression or for development so I I + + align:start position:0% +for oppression or for development so I I + + + align:start position:0% +for oppression or for development so I I +would love teachers who are watching + + align:start position:0% +would love teachers who are watching + + + align:start position:0% +would love teachers who are watching +this this video and we look at the + + align:start position:0% +this this video and we look at the + + + align:start position:0% +this this video and we look at the +course to see how they can adapt the + + align:start position:0% +course to see how they can adapt the + + + align:start position:0% +course to see how they can adapt the +content in order to address similar + + align:start position:0% +content in order to address similar + + + align:start position:0% +content in order to address similar +issues in the own community because I + + align:start position:0% +issues in the own community because I + + + align:start position:0% +issues in the own community because I +think that what you see happening in the + + align:start position:0% +think that what you see happening in the + + + align:start position:0% +think that what you see happening in the +Kazakh languages also happens in in the + + align:start position:0% +Kazakh languages also happens in in the + + + align:start position:0% +Kazakh languages also happens in in the +u.s. appengine in in Europe in Latin + + align:start position:0% +u.s. appengine in in Europe in Latin + + + align:start position:0% +u.s. appengine in in Europe in Latin +America in Africa where language is + + align:start position:0% +America in Africa where language is + + + align:start position:0% +America in Africa where language is +often in use of this technology for + + align:start position:0% +often in use of this technology for + + + align:start position:0% +often in use of this technology for +domination or resistance and I think + + align:start position:0% +domination or resistance and I think + + + align:start position:0% +domination or resistance and I think +this course gives the some basic + + align:start position:0% +this course gives the some basic + + + align:start position:0% +this course gives the some basic +analytical tools to be able to analyze + + align:start position:0% +analytical tools to be able to analyze + + + align:start position:0% +analytical tools to be able to analyze +these patterns and and for me it's also + + align:start position:0% +these patterns and and for me it's also + + + align:start position:0% +these patterns and and for me it's also +very important that teachers in Haiti + + align:start position:0% +very important that teachers in Haiti + + + align:start position:0% +very important that teachers in Haiti +and Suez in Haiti including say you know + + align:start position:0% +and Suez in Haiti including say you know + + + align:start position:0% +and Suez in Haiti including say you know +future leaders or policy makers get to + + align:start position:0% +future leaders or policy makers get to + + + align:start position:0% +future leaders or policy makers get to +understand the discourse and the + + align:start position:0% +understand the discourse and the + + + align:start position:0% +understand the discourse and the +readings and to understand that that + + align:start position:0% +readings and to understand that that + + + align:start position:0% +readings and to understand that that +Haiti could do so much better if if + + align:start position:0% +Haiti could do so much better if if + + + align:start position:0% +Haiti could do so much better if if +teachers students leaders had this + + align:start position:0% +teachers students leaders had this + + + align:start position:0% +teachers students leaders had this +awareness of how the old attitudes + + align:start position:0% +awareness of how the old attitudes + + + align:start position:0% +awareness of how the old attitudes +towards Creole versus French have played + + align:start position:0% +towards Creole versus French have played + + + align:start position:0% +towards Creole versus French have played +over centuries in keeping the country in + + align:start position:0% +over centuries in keeping the country in + + + align:start position:0% +over centuries in keeping the country in +the developed and if they could get a + + align:start position:0% +the developed and if they could get a + + + align:start position:0% +the developed and if they could get a +better sense of the importance of + + align:start position:0% +better sense of the importance of + + + align:start position:0% +better sense of the importance of +language in education development then I + + align:start position:0% +language in education development then I + + + align:start position:0% +language in education development then I +think the country would do so much + + align:start position:0% +think the country would do so much + + + align:start position:0% +think the country would do so much +better but for me it's a it's a it's a + + align:start position:0% +better but for me it's a it's a it's a + + + align:start position:0% +better but for me it's a it's a it's a +key bottleneck that we have to go pass + + align:start position:0% +key bottleneck that we have to go pass + + + align:start position:0% +key bottleneck that we have to go pass +in order to really be able to develop a + + align:start position:0% +in order to really be able to develop a + + + align:start position:0% +in order to really be able to develop a +nation is to be is to be able to + + align:start position:0% +nation is to be is to be able to + + + align:start position:0% +nation is to be is to be able to +understand the history and the nature of + + align:start position:0% +understand the history and the nature of + + + align:start position:0% +understand the history and the nature of +your national your ancestral language + + align:start position:0% +your national your ancestral language + + + align:start position:0% +your national your ancestral language +and to be able to use it in the most + + align:start position:0% +and to be able to use it in the most + + + align:start position:0% +and to be able to use it in the most +systematic and water and productive way + + align:start position:0% +systematic and water and productive way + + + align:start position:0% +systematic and water and productive way +if you cannot do that there is no way + + align:start position:0% +if you cannot do that there is no way + + + align:start position:0% +if you cannot do that there is no way +that you can develop a whole nation that + + align:start position:0% +that you can develop a whole nation that + + + align:start position:0% +that you can develop a whole nation that +speaks that language \ No newline at end of file diff --git a/QKO_2WQkZ0k.txt b/QKO_2WQkZ0k.txt new file mode 100644 index 0000000000000000000000000000000000000000..b186f80934899942b0f762524ce5cb7472ec9588 --- /dev/null +++ b/QKO_2WQkZ0k.txt @@ -0,0 +1,2283 @@ +align:start position:0% + +pagerank is a measure of the importance + + align:start position:0% +pagerank is a measure of the importance + + + align:start position:0% +pagerank is a measure of the importance +of a web page + + align:start position:0% +of a web page + + + align:start position:0% +of a web page +but let me immediately correct my own + + align:start position:0% +but let me immediately correct my own + + + align:start position:0% +but let me immediately correct my own +confusion that i suffered from for some + + align:start position:0% +confusion that i suffered from for some + + + align:start position:0% +confusion that i suffered from for some +time until very recently which is that + + align:start position:0% +time until very recently which is that + + + align:start position:0% +time until very recently which is that +even though pagerank is used for ranking + + align:start position:0% +even though pagerank is used for ranking + + + align:start position:0% +even though pagerank is used for ranking +pages it's called pagerank after its + + align:start position:0% +pages it's called pagerank after its + + + align:start position:0% +pages it's called pagerank after its +effort after its discoverer developer + + align:start position:0% +effort after its discoverer developer + + + align:start position:0% +effort after its discoverer developer +larry page who is one of the co-founders + + align:start position:0% +larry page who is one of the co-founders + + + align:start position:0% +larry page who is one of the co-founders +along with serge brin of google + + align:start position:0% +along with serge brin of google + + + align:start position:0% +along with serge brin of google +so the motivation is that um when you at + + align:start position:0% +so the motivation is that um when you at + + + align:start position:0% +so the motivation is that um when you at +least before google when you did a + + align:start position:0% +least before google when you did a + + + align:start position:0% +least before google when you did a +standard retrieval on a web page using + + align:start position:0% +standard retrieval on a web page using + + + align:start position:0% +standard retrieval on a web page using +keyword search and similar kinds of + + align:start position:0% +keyword search and similar kinds of + + + align:start position:0% +keyword search and similar kinds of +criteria you'd get back millions of hits + + align:start position:0% +criteria you'd get back millions of hits + + + align:start position:0% +criteria you'd get back millions of hits +um most of which were really + + align:start position:0% +um most of which were really + + + align:start position:0% +um most of which were really +low quality and you weren't interested + + align:start position:0% +low quality and you weren't interested + + + align:start position:0% +low quality and you weren't interested +in and with a few useful pages buried in + + align:start position:0% +in and with a few useful pages buried in + + + align:start position:0% +in and with a few useful pages buried in +the millions and the question was uh all + + align:start position:0% +the millions and the question was uh all + + + align:start position:0% +the millions and the question was uh all +of these documents are indistinguishable + + align:start position:0% +of these documents are indistinguishable + + + align:start position:0% +of these documents are indistinguishable +in terms of keyword search and and + + align:start position:0% +in terms of keyword search and and + + + align:start position:0% +in terms of keyword search and and +textual patterns how do you figure out + + align:start position:0% +textual patterns how do you figure out + + + align:start position:0% +textual patterns how do you figure out +which of the important ones and the idea + + align:start position:0% +which of the important ones and the idea + + + align:start position:0% +which of the important ones and the idea +that + + align:start position:0% +that + + + align:start position:0% +that +that page came up with was to use the + + align:start position:0% +that page came up with was to use the + + + align:start position:0% +that page came up with was to use the +web structure itself the structure of + + align:start position:0% +web structure itself the structure of + + + align:start position:0% +web structure itself the structure of +the world wide web to identify the + + align:start position:0% +the world wide web to identify the + + + align:start position:0% +the world wide web to identify the +important documents + + align:start position:0% +important documents + + + align:start position:0% +important documents +so we can think of the + + align:start position:0% +so we can think of the + + + align:start position:0% +so we can think of the +uh the whole internet as a graph + + align:start position:0% +uh the whole internet as a graph + + + align:start position:0% +uh the whole internet as a graph +where a user is + + align:start position:0% +where a user is + + + align:start position:0% +where a user is +on a page and we think of a url as a + + align:start position:0% +on a page and we think of a url as a + + + align:start position:0% +on a page and we think of a url as a +link to another page as a directed edge + + align:start position:0% +link to another page as a directed edge + + + align:start position:0% +link to another page as a directed edge +and users are kind of randomly traveling + + align:start position:0% +and users are kind of randomly traveling + + + align:start position:0% +and users are kind of randomly traveling +around in the world wide web they're at + + align:start position:0% +around in the world wide web they're at + + + align:start position:0% +around in the world wide web they're at +a page they randomly click a link to get + + align:start position:0% +a page they randomly click a link to get + + + align:start position:0% +a page they randomly click a link to get +to another page and they keep doing + + align:start position:0% +to another page and they keep doing + + + align:start position:0% +to another page and they keep doing +doing a walk on the web graph and every + + align:start position:0% +doing a walk on the web graph and every + + + align:start position:0% +doing a walk on the web graph and every +once in a while they're going to find + + align:start position:0% +once in a while they're going to find + + + align:start position:0% +once in a while they're going to find +that the thread that they're on is kind + + align:start position:0% +that the thread that they're on is kind + + + align:start position:0% +that the thread that they're on is kind +of losing steam where they find + + align:start position:0% +of losing steam where they find + + + align:start position:0% +of losing steam where they find +themselves in some kind of a cycle and + + align:start position:0% +themselves in some kind of a cycle and + + + align:start position:0% +themselves in some kind of a cycle and +they will randomly start over again + + align:start position:0% +they will randomly start over again + + + align:start position:0% +they will randomly start over again +at some other page + + align:start position:0% +at some other page + + + align:start position:0% +at some other page +and we want to argue or + + align:start position:0% +and we want to argue or + + + align:start position:0% +and we want to argue or +hypothesize that a page is more + + align:start position:0% +hypothesize that a page is more + + + align:start position:0% +hypothesize that a page is more +important when it's viewed a large + + align:start position:0% +important when it's viewed a large + + + align:start position:0% +important when it's viewed a large +fraction of the time by these random + + align:start position:0% +fraction of the time by these random + + + align:start position:0% +fraction of the time by these random +browsers and random users + + align:start position:0% +browsers and random users + + + align:start position:0% +browsers and random users +so to be formal we're going to take the + + align:start position:0% +so to be formal we're going to take the + + + align:start position:0% +so to be formal we're going to take the +entire world wide web trillions of + + align:start position:0% +entire world wide web trillions of + + + align:start position:0% +entire world wide web trillions of +vertices as a digraph + + align:start position:0% +vertices as a digraph + + + align:start position:0% +vertices as a digraph +and + + align:start position:0% +and + + + align:start position:0% +and +there's going to be an edge from one url + + align:start position:0% +there's going to be an edge from one url + + + align:start position:0% +there's going to be an edge from one url +to another from v to w if there's a link + + align:start position:0% +to another from v to w if there's a link + + + align:start position:0% +to another from v to w if there's a link +from + + align:start position:0% +from + + + align:start position:0% +from +uh the page v to + + align:start position:0% +uh the page v to + + + align:start position:0% +uh the page v to +uh the page w or the url w w might not + + align:start position:0% +uh the page w or the url w w might not + + + align:start position:0% +uh the page w or the url w w might not +even be a page it might be a document + + align:start position:0% +even be a page it might be a document + + + align:start position:0% +even be a page it might be a document +which means it doesn't have any links on + + align:start position:0% +which means it doesn't have any links on + + + align:start position:0% +which means it doesn't have any links on +it but for the the the real vertices are + + align:start position:0% +it but for the the the real vertices are + + + align:start position:0% +it but for the the the real vertices are +the web pages that have links on them + + align:start position:0% +the web pages that have links on them + + + align:start position:0% +the web pages that have links on them +okay that's the model uh and we're gonna + + align:start position:0% +okay that's the model uh and we're gonna + + + align:start position:0% +okay that's the model uh and we're gonna +make it into a random walk graph by + + align:start position:0% +make it into a random walk graph by + + + align:start position:0% +make it into a random walk graph by +saying that if you look at a + + align:start position:0% +saying that if you look at a + + + align:start position:0% +saying that if you look at a +url v a vertex v all of the edges out of + + align:start position:0% +url v a vertex v all of the edges out of + + + align:start position:0% +url v a vertex v all of the edges out of +it are equally likely it's a simple + + align:start position:0% +it are equally likely it's a simple + + + align:start position:0% +it are equally likely it's a simple +model and it might or might not work but + + align:start position:0% +model and it might or might not work but + + + align:start position:0% +model and it might or might not work but +in fact it did work pretty well that is + + align:start position:0% +in fact it did work pretty well that is + + + align:start position:0% +in fact it did work pretty well that is +the + + align:start position:0% +the + + + align:start position:0% +the +model of the world wide web + + align:start position:0% +model of the world wide web + + + align:start position:0% +model of the world wide web +as + + align:start position:0% +as + + + align:start position:0% +as +a random walk graph + + align:start position:0% +a random walk graph + + + align:start position:0% +a random walk graph +so to be more precise the probability of + + align:start position:0% +so to be more precise the probability of + + + align:start position:0% +so to be more precise the probability of +the edge that goes from v to w + + align:start position:0% +the edge that goes from v to w + + + align:start position:0% +the edge that goes from v to w +is + + align:start position:0% +is + + + align:start position:0% +is +one over the out degree of v that is all + + align:start position:0% +one over the out degree of v that is all + + + align:start position:0% +one over the out degree of v that is all +of the out degree of v edges leaving + + align:start position:0% +of the out degree of v edges leaving + + + align:start position:0% +of the out degree of v edges leaving +vertex v get equal weight + + align:start position:0% +vertex v get equal weight + + + align:start position:0% +vertex v get equal weight +now to model this aspect that the users + + align:start position:0% +now to model this aspect that the users + + + align:start position:0% +now to model this aspect that the users +start over again if they get bored or + + align:start position:0% +start over again if they get bored or + + + align:start position:0% +start over again if they get bored or +they get stuck + + align:start position:0% +they get stuck + + + align:start position:0% +they get stuck +we can formally add to the digraph a + + align:start position:0% +we can formally add to the digraph a + + + align:start position:0% +we can formally add to the digraph a +hypothetical super node + + align:start position:0% +hypothetical super node + + + align:start position:0% +hypothetical super node +um which and with the property that + + align:start position:0% +um which and with the property that + + + align:start position:0% +um which and with the property that +there's an edge from the super node to + + align:start position:0% +there's an edge from the super node to + + + align:start position:0% +there's an edge from the super node to +every other node with equally likelihood + + align:start position:0% +every other node with equally likelihood + + + align:start position:0% +every other node with equally likelihood +so once you're the super mode then + + align:start position:0% +so once you're the super mode then + + + align:start position:0% +so once you're the super mode then +following an edge is tantamount to + + align:start position:0% +following an edge is tantamount to + + + align:start position:0% +following an edge is tantamount to +saying pick a random page and start over + + align:start position:0% +saying pick a random page and start over + + + align:start position:0% +saying pick a random page and start over +again + + align:start position:0% +again + + + align:start position:0% +again +um + + align:start position:0% +um + + + align:start position:0% +um +to get to the super node we uh have no + + align:start position:0% +to get to the super node we uh have no + + + align:start position:0% +to get to the super node we uh have no +we have edges back from + + align:start position:0% +we have edges back from + + + align:start position:0% +we have edges back from +other nodes in the graph back to the + + align:start position:0% +other nodes in the graph back to the + + + align:start position:0% +other nodes in the graph back to the +super node now in the reading we said + + align:start position:0% +super node now in the reading we said + + + align:start position:0% +super node now in the reading we said +that uh we were going to have nodes back + + align:start position:0% +that uh we were going to have nodes back + + + align:start position:0% +that uh we were going to have nodes back +from uh from no terminal nodes that had + + align:start position:0% +from uh from no terminal nodes that had + + + align:start position:0% +from uh from no terminal nodes that had +no edges out for example a document or + + align:start position:0% +no edges out for example a document or + + + align:start position:0% +no edges out for example a document or +something like that that's actually not + + align:start position:0% +something like that that's actually not + + + align:start position:0% +something like that that's actually not +sufficient because uh for the + + align:start position:0% +sufficient because uh for the + + + align:start position:0% +sufficient because uh for the +for the pagerank to work in the + + align:start position:0% +for the pagerank to work in the + + + align:start position:0% +for the pagerank to work in the +theoretical way that we want it to + + align:start position:0% +theoretical way that we want it to + + + align:start position:0% +theoretical way that we want it to +because even if there is um no dead + + align:start position:0% +because even if there is um no dead + + + align:start position:0% +because even if there is um no dead +nodes you might be in a clump of nodes + + align:start position:0% +nodes you might be in a clump of nodes + + + align:start position:0% +nodes you might be in a clump of nodes +which you can't get out of and you'd + + align:start position:0% +which you can't get out of and you'd + + + align:start position:0% +which you can't get out of and you'd +want to be able to and even though none + + align:start position:0% +want to be able to and even though none + + + align:start position:0% +want to be able to and even though none +of them was a dead end because they all + + align:start position:0% +of them was a dead end because they all + + + align:start position:0% +of them was a dead end because they all +had arrows going out to each other and + + align:start position:0% +had arrows going out to each other and + + + align:start position:0% +had arrows going out to each other and +so you'd really want a node from an edge + + align:start position:0% +so you'd really want a node from an edge + + + align:start position:0% +so you'd really want a node from an edge +from a clump like that back to the super + + align:start position:0% +from a clump like that back to the super + + + align:start position:0% +from a clump like that back to the super +node to model starting over there + + align:start position:0% +node to model starting over there + + + align:start position:0% +node to model starting over there +the simplest way to do it really is to + + align:start position:0% +the simplest way to do it really is to + + + align:start position:0% +the simplest way to do it really is to +simply say that there's an edge to the + + align:start position:0% +simply say that there's an edge to the + + + align:start position:0% +simply say that there's an edge to the +super node from every vertex so where + + align:start position:0% +super node from every vertex so where + + + align:start position:0% +super node from every vertex so where +wherever you are you can randomly decide + + align:start position:0% +wherever you are you can randomly decide + + + align:start position:0% +wherever you are you can randomly decide +to start over but uh and + + align:start position:0% +to start over but uh and + + + align:start position:0% +to start over but uh and +paige uh and brynn and their co-authors + + align:start position:0% +paige uh and brynn and their co-authors + + + align:start position:0% +paige uh and brynn and their co-authors +in the original paper on page rank uh + + align:start position:0% +in the original paper on page rank uh + + + align:start position:0% +in the original paper on page rank uh +suggested that the edge back from a + + align:start position:0% +suggested that the edge back from a + + + align:start position:0% +suggested that the edge back from a +vertex to the super vertex might get a + + align:start position:0% +vertex to the super vertex might get a + + + align:start position:0% +vertex to the super vertex might get a +special probability it might be + + align:start position:0% +special probability it might be + + + align:start position:0% +special probability it might be +customized as opposed to being + + align:start position:0% +customized as opposed to being + + + align:start position:0% +customized as opposed to being +uh equally likely with all of the other + + align:start position:0% +uh equally likely with all of the other + + + align:start position:0% +uh equally likely with all of the other +uh edges leading a vertex in fact i + + align:start position:0% +uh edges leading a vertex in fact i + + + align:start position:0% +uh edges leading a vertex in fact i +think they decided that it there should + + align:start position:0% +think they decided that it there should + + + align:start position:0% +think they decided that it there should +be a 0.15 probability from each vertex + + align:start position:0% +be a 0.15 probability from each vertex + + + align:start position:0% +be a 0.15 probability from each vertex +of + + align:start position:0% +of + + + align:start position:0% +of +jumping at random to the super node + + align:start position:0% +jumping at random to the super node + + + align:start position:0% +jumping at random to the super node +okay um + + align:start position:0% +okay um + + + align:start position:0% +okay um +let's just illustrate this with an + + align:start position:0% +let's just illustrate this with an + + + align:start position:0% +let's just illustrate this with an +example this is a random walk graph that + + align:start position:0% +example this is a random walk graph that + + + align:start position:0% +example this is a random walk graph that +we've seen before modeling coin flipping + + align:start position:0% +we've seen before modeling coin flipping + + + align:start position:0% +we've seen before modeling coin flipping +and when i add the super node there's + + align:start position:0% +and when i add the super node there's + + + align:start position:0% +and when i add the super node there's +this one new uh + + align:start position:0% +this one new uh + + + align:start position:0% +this one new uh +vertex super and there's an edge from + + align:start position:0% +vertex super and there's an edge from + + + align:start position:0% +vertex super and there's an edge from +the super vertex to every other one of + + align:start position:0% +the super vertex to every other one of + + + align:start position:0% +the super vertex to every other one of +the vertices in the graph and from each + + align:start position:0% +the vertices in the graph and from each + + + align:start position:0% +the vertices in the graph and from each +vertex in the graph there is an edge + + align:start position:0% +vertex in the graph there is an edge + + + align:start position:0% +vertex in the graph there is an edge +going back i've illustrated that with + + align:start position:0% +going back i've illustrated that with + + + align:start position:0% +going back i've illustrated that with +two-way arrows + + align:start position:0% +two-way arrows + + + align:start position:0% +two-way arrows +so this is really + + align:start position:0% +so this is really + + + align:start position:0% +so this is really +an arrow with two arrowheads it + + align:start position:0% +an arrow with two arrowheads it + + + align:start position:0% +an arrow with two arrowheads it +represents an arrow in each direction + + align:start position:0% +represents an arrow in each direction + + + align:start position:0% +represents an arrow in each direction +now in the original paper actually uh + + align:start position:0% +now in the original paper actually uh + + + align:start position:0% +now in the original paper actually uh +paige didn't talk about a super vertex + + align:start position:0% +paige didn't talk about a super vertex + + + align:start position:0% +paige didn't talk about a super vertex +instead he talked about + + align:start position:0% +instead he talked about + + + align:start position:0% +instead he talked about +each vertex randomly jumping to another + + align:start position:0% +each vertex randomly jumping to another + + + align:start position:0% +each vertex randomly jumping to another +vertex but that would just get the whole + + align:start position:0% +vertex but that would just get the whole + + + align:start position:0% +vertex but that would just get the whole +state diagram completely clogged up with + + align:start position:0% +state diagram completely clogged up with + + + align:start position:0% +state diagram completely clogged up with +edges so it's more economical to have + + align:start position:0% +edges so it's more economical to have + + + align:start position:0% +edges so it's more economical to have +everybody jump to the super vertex + + align:start position:0% +everybody jump to the super vertex + + + align:start position:0% +everybody jump to the super vertex +and the super vertex jump back to + + align:start position:0% +and the super vertex jump back to + + + align:start position:0% +and the super vertex jump back to +everybody + + align:start position:0% +everybody + + + align:start position:0% +everybody +and that + + align:start position:0% +and that + + + align:start position:0% +and that +saves a significant number of edges + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +pagerank then is obtained by computing a + + align:start position:0% +pagerank then is obtained by computing a + + + align:start position:0% +pagerank then is obtained by computing a +stationary distribution for the world + + align:start position:0% +stationary distribution for the world + + + align:start position:0% +stationary distribution for the world +wide web + + align:start position:0% +wide web + + + align:start position:0% +wide web +so s bar is a vector of length trillions + + align:start position:0% +so s bar is a vector of length trillions + + + align:start position:0% +so s bar is a vector of length trillions +the chord chord the coordinates are + + align:start position:0% +the chord chord the coordinates are + + + align:start position:0% +the chord chord the coordinates are +indexed by the web pages + + align:start position:0% +indexed by the web pages + + + align:start position:0% +indexed by the web pages +and we want to calculate the stable + + align:start position:0% +and we want to calculate the stable + + + align:start position:0% +and we want to calculate the stable +distribution and then we simply define + + align:start position:0% +distribution and then we simply define + + + align:start position:0% +distribution and then we simply define +the pagerank of a page is its + + align:start position:0% +the pagerank of a page is its + + + align:start position:0% +the pagerank of a page is its +its probability of being there in the + + align:start position:0% +its probability of being there in the + + + align:start position:0% +its probability of being there in the +stationary distribution the v component + + align:start position:0% +stationary distribution the v component + + + align:start position:0% +stationary distribution the v component +of the stable of the stationary + + align:start position:0% +of the stable of the stationary + + + align:start position:0% +of the stable of the stationary +distribution s + + align:start position:0% +distribution s + + + align:start position:0% +distribution s +and of course we'll rank v above s when + + align:start position:0% +and of course we'll rank v above s when + + + align:start position:0% +and of course we'll rank v above s when +the probability of being in v + + align:start position:0% +the probability of being in v + + + align:start position:0% +the probability of being in v +is higher than the probability of being + + align:start position:0% +is higher than the probability of being + + + align:start position:0% +is higher than the probability of being +in w + + align:start position:0% + + + + align:start position:0% + +by the way um + + align:start position:0% +by the way um + + + align:start position:0% +by the way um +i don't have the latest figures but uh + + align:start position:0% +i don't have the latest figures but uh + + + align:start position:0% +i don't have the latest figures but uh +there were + + align:start position:0% +there were + + + align:start position:0% +there were +uh i guess i've heard people have worked + + align:start position:0% +uh i guess i've heard people have worked + + + align:start position:0% +uh i guess i've heard people have worked +for google say and in some of the + + align:start position:0% +for google say and in some of the + + + align:start position:0% +for google say and in some of the +wikipedia articles that it takes a few + + align:start position:0% +wikipedia articles that it takes a few + + + align:start position:0% +wikipedia articles that it takes a few +weeks for the crawlers to + + align:start position:0% +weeks for the crawlers to + + + align:start position:0% +weeks for the crawlers to +create a new map of the web + + align:start position:0% +create a new map of the web + + + align:start position:0% +create a new map of the web +to create the new graph and then it + + align:start position:0% +to create the new graph and then it + + + align:start position:0% +to create the new graph and then it +takes um + + align:start position:0% +takes um + + + align:start position:0% +takes um +some number of hours i think under days + + align:start position:0% +some number of hours i think under days + + + align:start position:0% +some number of hours i think under days +to calculate the stationary distribution + + align:start position:0% +to calculate the stationary distribution + + + align:start position:0% +to calculate the stationary distribution +on the graph + + align:start position:0% +on the graph + + + align:start position:0% +on the graph +doing a lot of parallel computation + + align:start position:0% + + + + align:start position:0% + +so a useful feature about the uh using + + align:start position:0% +so a useful feature about the uh using + + + align:start position:0% +so a useful feature about the uh using +the the stationary distribution is that + + align:start position:0% +the the stationary distribution is that + + + align:start position:0% +the the stationary distribution is that +ways to hack uh the + + align:start position:0% +ways to hack uh the + + + align:start position:0% +ways to hack uh the +links in the world wide web to make a + + align:start position:0% +links in the world wide web to make a + + + align:start position:0% +links in the world wide web to make a +page look important are + + align:start position:0% +page look important are + + + align:start position:0% +page look important are +will not work very well against page + + align:start position:0% +will not work very well against page + + + align:start position:0% +will not work very well against page +rank so for example one way to look more + + align:start position:0% +rank so for example one way to look more + + + align:start position:0% +rank so for example one way to look more +important is to create a lot of nodes + + align:start position:0% +important is to create a lot of nodes + + + align:start position:0% +important is to create a lot of nodes +pointing to yourself fake nodes but + + align:start position:0% +pointing to yourself fake nodes but + + + align:start position:0% +pointing to yourself fake nodes but +that's not going to matter because the + + align:start position:0% +that's not going to matter because the + + + align:start position:0% +that's not going to matter because the +fake notes are not going to have much + + align:start position:0% +fake notes are not going to have much + + + align:start position:0% +fake notes are not going to have much +weight since they're fake and nobody's + + align:start position:0% +weight since they're fake and nobody's + + + align:start position:0% +weight since they're fake and nobody's +pointing to them so even though a large + + align:start position:0% +pointing to them so even though a large + + + align:start position:0% +pointing to them so even though a large +number of fake notes + + align:start position:0% +number of fake notes + + + align:start position:0% +number of fake notes +point to you + + align:start position:0% +point to you + + + align:start position:0% +point to you +their cumulative weight is low and + + align:start position:0% +their cumulative weight is low and + + + align:start position:0% +their cumulative weight is low and +they're not adding a lot to your own + + align:start position:0% +they're not adding a lot to your own + + + align:start position:0% +they're not adding a lot to your own +probability + + align:start position:0% +probability + + + align:start position:0% +probability +likewise you could try taking links to + + align:start position:0% +likewise you could try taking links to + + + align:start position:0% +likewise you could try taking links to +important pages + + align:start position:0% +important pages + + + align:start position:0% +important pages +and try to make yourself look important + + align:start position:0% +and try to make yourself look important + + + align:start position:0% +and try to make yourself look important +that way but pagerank won't make you + + align:start position:0% +that way but pagerank won't make you + + + align:start position:0% +that way but pagerank won't make you +look important at all if none of those + + align:start position:0% +look important at all if none of those + + + align:start position:0% +look important at all if none of those +important nodes are pointing back + + align:start position:0% +important nodes are pointing back + + + align:start position:0% +important nodes are pointing back +so both of these simple-minded ways to + + align:start position:0% +so both of these simple-minded ways to + + + align:start position:0% +so both of these simple-minded ways to +try to look important by manipulating + + align:start position:0% +try to look important by manipulating + + + align:start position:0% +try to look important by manipulating +links won't improve your pagerank + + align:start position:0% +links won't improve your pagerank + + + align:start position:0% +links won't improve your pagerank +the supernode is playing a technical + + align:start position:0% +the supernode is playing a technical + + + align:start position:0% +the supernode is playing a technical +role + + align:start position:0% +role + + + align:start position:0% +role +in making sure that the stationary + + align:start position:0% +in making sure that the stationary + + + align:start position:0% +in making sure that the stationary +uh distribution exists so + + align:start position:0% +uh distribution exists so + + + align:start position:0% +uh distribution exists so +um uh it guarantees that there's a + + align:start position:0% +um uh it guarantees that there's a + + + align:start position:0% +um uh it guarantees that there's a +unique stationary distribution as bar by + + align:start position:0% +unique stationary distribution as bar by + + + align:start position:0% +unique stationary distribution as bar by +the way i sometimes use the word stable + + align:start position:0% +the way i sometimes use the word stable + + + align:start position:0% +the way i sometimes use the word stable +and sometimes stationary they're kind of + + align:start position:0% +and sometimes stationary they're kind of + + + align:start position:0% +and sometimes stationary they're kind of +synonyms um although i think officially + + align:start position:0% +synonyms um although i think officially + + + align:start position:0% +synonyms um although i think officially +we should stick to the word stationary + + align:start position:0% +we should stick to the word stationary + + + align:start position:0% +we should stick to the word stationary +distribution + + align:start position:0% +distribution + + + align:start position:0% +distribution +um when as i've mentioned before when a + + align:start position:0% +um when as i've mentioned before when a + + + align:start position:0% +um when as i've mentioned before when a +a digraph is strongly connected that is + + align:start position:0% +a digraph is strongly connected that is + + + align:start position:0% +a digraph is strongly connected that is +a sufficient condition for there to be a + + align:start position:0% +a sufficient condition for there to be a + + + align:start position:0% +a sufficient condition for there to be a +unique stable distribution that's + + align:start position:0% +unique stable distribution that's + + + align:start position:0% +unique stable distribution that's +actually proved in one of the exercises + + align:start position:0% +actually proved in one of the exercises + + + align:start position:0% +actually proved in one of the exercises +in the text at the end of the chapter + + align:start position:0% + + + + align:start position:0% + +the supernode mechanism also + + align:start position:0% +the supernode mechanism also + + + align:start position:0% +the supernode mechanism also +ensures something even stronger that + + align:start position:0% +ensures something even stronger that + + + align:start position:0% +ensures something even stronger that +every initial distribution pay converges + + align:start position:0% +every initial distribution pay converges + + + align:start position:0% +every initial distribution pay converges +to the + + align:start position:0% +to the + + + align:start position:0% +to the +uh + + align:start position:0% +uh + + + align:start position:0% +uh +stationary distribution to that unique + + align:start position:0% +stationary distribution to that unique + + + align:start position:0% +stationary distribution to that unique +stationary distribution state precisely + + align:start position:0% +stationary distribution state precisely + + + align:start position:0% +stationary distribution state precisely +mathematically + + align:start position:0% +mathematically + + + align:start position:0% +mathematically +if you start off at an arbitrary + + align:start position:0% +if you start off at an arbitrary + + + align:start position:0% +if you start off at an arbitrary +distribution of + + align:start position:0% +distribution of + + + align:start position:0% +distribution of +probabilities of being in different + + align:start position:0% +probabilities of being in different + + + align:start position:0% +probabilities of being in different +states p + + align:start position:0% +states p + + + align:start position:0% +states p +and you look at what happens to + + align:start position:0% +and you look at what happens to + + + align:start position:0% +and you look at what happens to +p after t steps remember that you get by + + align:start position:0% +p after t steps remember that you get by + + + align:start position:0% +p after t steps remember that you get by +multiplying the vector p by the matrix + + align:start position:0% +multiplying the vector p by the matrix + + + align:start position:0% +multiplying the vector p by the matrix +m raised to the power t + + align:start position:0% +m raised to the power t + + + align:start position:0% +m raised to the power t +and you take the limit as t approaches + + align:start position:0% +and you take the limit as t approaches + + + align:start position:0% +and you take the limit as t approaches +infinity that is to say + + align:start position:0% +infinity that is to say + + + align:start position:0% +infinity that is to say +what distribution do you approach as you + + align:start position:0% +what distribution do you approach as you + + + align:start position:0% +what distribution do you approach as you +do more and more updates + + align:start position:0% +do more and more updates + + + align:start position:0% +do more and more updates +and it turns out that that limit exists + + align:start position:0% +and it turns out that that limit exists + + + align:start position:0% +and it turns out that that limit exists +and it is that stationary distribution + + align:start position:0% +and it is that stationary distribution + + + align:start position:0% +and it is that stationary distribution +so it doesn't matter where you start + + align:start position:0% +so it doesn't matter where you start + + + align:start position:0% +so it doesn't matter where you start +you're going to wind up stable and as a + + align:start position:0% +you're going to wind up stable and as a + + + align:start position:0% +you're going to wind up stable and as a +matter of fact the convergence is rapid + + align:start position:0% +matter of fact the convergence is rapid + + + align:start position:0% +matter of fact the convergence is rapid +what that means is that you can actually + + align:start position:0% +what that means is that you can actually + + + align:start position:0% +what that means is that you can actually +calculate the stable distribution + + align:start position:0% +calculate the stable distribution + + + align:start position:0% +calculate the stable distribution +reasonably quickly because you don't + + align:start position:0% +reasonably quickly because you don't + + + align:start position:0% +reasonably quickly because you don't +need a very large t in order to arrive + + align:start position:0% +need a very large t in order to arrive + + + align:start position:0% +need a very large t in order to arrive +at a very good approximation to the + + align:start position:0% +at a very good approximation to the + + + align:start position:0% +at a very good approximation to the +stable distribution + + align:start position:0% +stable distribution + + + align:start position:0% +stable distribution +now the actual google + + align:start position:0% +now the actual google + + + align:start position:0% +now the actual google +rank uh and ranking is more complicated + + align:start position:0% +rank uh and ranking is more complicated + + + align:start position:0% +rank uh and ranking is more complicated +than just page rank pagerank was the + + align:start position:0% +than just page rank pagerank was the + + + align:start position:0% +than just page rank pagerank was the +original idea that got a lot of + + align:start position:0% +original idea that got a lot of + + + align:start position:0% +original idea that got a lot of +attention and in fact the latest + + align:start position:0% +attention and in fact the latest + + + align:start position:0% +attention and in fact the latest +information from google is that they + + align:start position:0% +information from google is that they + + + align:start position:0% +information from google is that they +think it gets over attention in the uh + + align:start position:0% +think it gets over attention in the uh + + + align:start position:0% +think it gets over attention in the uh +today in the modern world by too many + + align:start position:0% +today in the modern world by too many + + + align:start position:0% +today in the modern world by too many +commentators and and people trying to uh + + align:start position:0% +commentators and and people trying to uh + + + align:start position:0% +commentators and and people trying to uh +simulate ranking + + align:start position:0% +simulate ranking + + + align:start position:0% +simulate ranking +so the actual rank rules are a closely + + align:start position:0% +so the actual rank rules are a closely + + + align:start position:0% +so the actual rank rules are a closely +held trade secret for google by google + + align:start position:0% +held trade secret for google by google + + + align:start position:0% +held trade secret for google by google +they use text they use location they use + + align:start position:0% +they use text they use location they use + + + align:start position:0% +they use text they use location they use +payments because advertisers can pay to + + align:start position:0% +payments because advertisers can pay to + + + align:start position:0% +payments because advertisers can pay to +have their search results listed more + + align:start position:0% +have their search results listed more + + + align:start position:0% +have their search results listed more +prominently + + align:start position:0% +prominently + + + align:start position:0% +prominently +and lots of other criteria that have + + align:start position:0% +and lots of other criteria that have + + + align:start position:0% +and lots of other criteria that have +evolved over 15 years and they continue + + align:start position:0% +evolved over 15 years and they continue + + + align:start position:0% +evolved over 15 years and they continue +to evolve as people find ways to + + align:start position:0% +to evolve as people find ways to + + + align:start position:0% +to evolve as people find ways to +manipulate the ranking google revises + + align:start position:0% +manipulate the ranking google revises + + + align:start position:0% +manipulate the ranking google revises +its ranking criteria and algorithms but + + align:start position:0% +its ranking criteria and algorithms but + + + align:start position:0% +its ranking criteria and algorithms but +nevertheless pagerank continues to play + + align:start position:0% +nevertheless pagerank continues to play + + + align:start position:0% +nevertheless pagerank continues to play +a significant role in the whole story \ No newline at end of file diff --git a/QfYSZlfBV9A.txt b/QfYSZlfBV9A.txt new file mode 100644 index 0000000000000000000000000000000000000000..704e037837c15a6ccdd38ecd5c11c3d1b4a51d82 --- /dev/null +++ b/QfYSZlfBV9A.txt @@ -0,0 +1,15419 @@ +align:start position:0% + +foreign + + align:start position:0% + + + + align:start position:0% + +welcome everyone + + align:start position:0% +welcome everyone + + + align:start position:0% +welcome everyone +um this uh optional informal uh + + align:start position:0% +um this uh optional informal uh + + + align:start position:0% +um this uh optional informal uh +discussion for um 8225 + + align:start position:0% +discussion for um 8225 + + + align:start position:0% +discussion for um 8225 +sgs042 uh as hopefully you all know + + align:start position:0% +sgs042 uh as hopefully you all know + + + align:start position:0% +sgs042 uh as hopefully you all know +we're + + align:start position:0% +we're + + + align:start position:0% +we're +just going to take our time just very + + align:start position:0% +just going to take our time just very + + + align:start position:0% +just going to take our time just very +informally + + align:start position:0% +informally + + + align:start position:0% +informally +um chat about really anything that's on + + align:start position:0% +um chat about really anything that's on + + + align:start position:0% +um chat about really anything that's on +your mind around the most recent + + align:start position:0% +your mind around the most recent + + + align:start position:0% +your mind around the most recent +material but in particular things that + + align:start position:0% +material but in particular things that + + + align:start position:0% +material but in particular things that +might have been + + align:start position:0% +might have been + + + align:start position:0% +might have been +um curious or puzzling or disturbing or + + align:start position:0% +um curious or puzzling or disturbing or + + + align:start position:0% +um curious or puzzling or disturbing or +whatever any of the above + + align:start position:0% +whatever any of the above + + + align:start position:0% +whatever any of the above +um that might have been + + align:start position:0% +um that might have been + + + align:start position:0% +um that might have been +um elicited in your mind upon watching + + align:start position:0% +um elicited in your mind upon watching + + + align:start position:0% +um elicited in your mind upon watching +the documentary film the day after + + align:start position:0% +the documentary film the day after + + + align:start position:0% +the documentary film the day after +Trinity + + align:start position:0% +Trinity + + + align:start position:0% +Trinity +um I actually watched the YouTube + + align:start position:0% +um I actually watched the YouTube + + + align:start position:0% +um I actually watched the YouTube +version with + + align:start position:0% +version with + + + align:start position:0% +version with +so my family over the weekend I didn't + + align:start position:0% +so my family over the weekend I didn't + + + align:start position:0% +so my family over the weekend I didn't +realize how poor the video quality was I + + align:start position:0% +realize how poor the video quality was I + + + align:start position:0% +realize how poor the video quality was I +apologize for that if you're watching on + + align:start position:0% +apologize for that if you're watching on + + + align:start position:0% +apologize for that if you're watching on +a small device maybe you didn't notice + + align:start position:0% +a small device maybe you didn't notice + + + align:start position:0% +a small device maybe you didn't notice +but if you were watching a super big + + align:start position:0% +but if you were watching a super big + + + align:start position:0% +but if you were watching a super big +crazy large TV you would have seen it + + align:start position:0% +crazy large TV you would have seen it + + + align:start position:0% +crazy large TV you would have seen it +was very blotchy visually but anyway + + align:start position:0% +was very blotchy visually but anyway + + + align:start position:0% +was very blotchy visually but anyway +hopefully it was nonetheless clear + + align:start position:0% +hopefully it was nonetheless clear + + + align:start position:0% +hopefully it was nonetheless clear +enough to uh to get the gist + + align:start position:0% +enough to uh to get the gist + + + align:start position:0% +enough to uh to get the gist +um and I have no sort of agenda for + + align:start position:0% +um and I have no sort of agenda for + + + align:start position:0% +um and I have no sort of agenda for +today I'm really just happy to go uh + + align:start position:0% +today I'm really just happy to go uh + + + align:start position:0% +today I'm really just happy to go uh +however whatever questions are on or + + align:start position:0% +however whatever questions are on or + + + align:start position:0% +however whatever questions are on or +comments or thoughts are on people's + + align:start position:0% +comments or thoughts are on people's + + + align:start position:0% +comments or thoughts are on people's +minds so anyone should feel free to jump + + align:start position:0% +minds so anyone should feel free to jump + + + align:start position:0% +minds so anyone should feel free to jump +in I think I expect we'll have a small + + align:start position:0% +in I think I expect we'll have a small + + + align:start position:0% +in I think I expect we'll have a small +enough group again we don't have to + + align:start position:0% +enough group again we don't have to + + + align:start position:0% +enough group again we don't have to +worry about breakout rooms we can just + + align:start position:0% +worry about breakout rooms we can just + + + align:start position:0% +worry about breakout rooms we can just +kind of manage the discussion hopefully + + align:start position:0% +kind of manage the discussion hopefully + + + align:start position:0% +kind of manage the discussion hopefully +pretty uh informally with the group this + + align:start position:0% +pretty uh informally with the group this + + + align:start position:0% +pretty uh informally with the group this +way + + align:start position:0% +way + + + align:start position:0% +way +so I'm curious I mean just the floor is + + align:start position:0% +so I'm curious I mean just the floor is + + + align:start position:0% +so I'm curious I mean just the floor is +open were were there things that + + align:start position:0% +open were were there things that + + + align:start position:0% +open were were there things that +um surprised you from the film things + + align:start position:0% +um surprised you from the film things + + + align:start position:0% +um surprised you from the film things +that surprised you the film didn't you + + align:start position:0% +that surprised you the film didn't you + + + align:start position:0% +that surprised you the film didn't you +know Broach or cover and anything + + align:start position:0% +know Broach or cover and anything + + + align:start position:0% +know Broach or cover and anything +anything the whole the whole Topic's + + align:start position:0% +anything the whole the whole Topic's + + + align:start position:0% +anything the whole the whole Topic's +open + + align:start position:0% + + + + align:start position:0% + +really interesting question that's + + align:start position:0% +really interesting question that's + + + align:start position:0% +really interesting question that's +that's a juicy one + + align:start position:0% +that's a juicy one + + + align:start position:0% +that's a juicy one +um and I should also say by the way I as + + align:start position:0% +um and I should also say by the way I as + + + align:start position:0% +um and I should also say by the way I as +you even more than usual I invite the + + align:start position:0% +you even more than usual I invite the + + + align:start position:0% +you even more than usual I invite the +Tas to jump in as well uh please don't + + align:start position:0% +Tas to jump in as well uh please don't + + + align:start position:0% +Tas to jump in as well uh please don't +be shy + + align:start position:0% +be shy + + + align:start position:0% +be shy +um but let me give you my my first crack + + align:start position:0% +um but let me give you my my first crack + + + align:start position:0% +um but let me give you my my first crack +at that um + + align:start position:0% + + + + align:start position:0% + +I think a lot of people who were + + align:start position:0% +I think a lot of people who were + + + align:start position:0% +I think a lot of people who were +convinced to work on the project and the + + align:start position:0% +convinced to work on the project and the + + + align:start position:0% +convinced to work on the project and the +film gives a little hit to that they + + align:start position:0% +film gives a little hit to that they + + + align:start position:0% +film gives a little hit to that they +really were not given very much in + + align:start position:0% +really were not given very much in + + + align:start position:0% +really were not given very much in +advance to go on right they had to make + + align:start position:0% +advance to go on right they had to make + + + align:start position:0% +advance to go on right they had to make +a fairly snap decision uh in the middle + + align:start position:0% +a fairly snap decision uh in the middle + + + align:start position:0% +a fairly snap decision uh in the middle +of very you know dislocated times + + align:start position:0% +of very you know dislocated times + + + align:start position:0% +of very you know dislocated times +and often because of Secret City they + + align:start position:0% +and often because of Secret City they + + + align:start position:0% +and often because of Secret City they +couldn't be given a kind of full + + align:start position:0% +couldn't be given a kind of full + + + align:start position:0% +couldn't be given a kind of full +briefing ahead of time some of them + + align:start position:0% +briefing ahead of time some of them + + + align:start position:0% +briefing ahead of time some of them +didn't didn't have much idea of what was + + align:start position:0% +didn't didn't have much idea of what was + + + align:start position:0% +didn't didn't have much idea of what was +coming + + align:start position:0% +coming + + + align:start position:0% +coming +and I my sense there's a lot of the + + align:start position:0% +and I my sense there's a lot of the + + + align:start position:0% +and I my sense there's a lot of the +folks who who did volunteer then to join + + align:start position:0% +folks who who did volunteer then to join + + + align:start position:0% +folks who who did volunteer then to join +the project + + align:start position:0% +the project + + + align:start position:0% +the project +um + + align:start position:0% +um + + + align:start position:0% +um +really we're deeply concerned about uh + + align:start position:0% +really we're deeply concerned about uh + + + align:start position:0% +really we're deeply concerned about uh +developments in Europe especially around + + align:start position:0% +developments in Europe especially around + + + align:start position:0% +developments in Europe especially around +uh what looked like the kind of + + align:start position:0% +uh what looked like the kind of + + + align:start position:0% +uh what looked like the kind of +unchecked uh military progress of the + + align:start position:0% +unchecked uh military progress of the + + + align:start position:0% +unchecked uh military progress of the +Nazis + + align:start position:0% +Nazis + + + align:start position:0% +Nazis +um so I think there was uh a sense that + + align:start position:0% +um so I think there was uh a sense that + + + align:start position:0% +um so I think there was uh a sense that +they that that they wanted to find some + + align:start position:0% +they that that they wanted to find some + + + align:start position:0% +they that that they wanted to find some +way to contribute + + align:start position:0% +way to contribute + + + align:start position:0% +way to contribute +to to the defense effort to the war + + align:start position:0% +to to the defense effort to the war + + + align:start position:0% +to to the defense effort to the war +effort + + align:start position:0% +effort + + + align:start position:0% +effort +um now that raises other questions which + + align:start position:0% +um now that raises other questions which + + + align:start position:0% +um now that raises other questions which +which are broached at least briefly in + + align:start position:0% +which are broached at least briefly in + + + align:start position:0% +which are broached at least briefly in +the film if if many people's principal + + align:start position:0% +the film if if many people's principal + + + align:start position:0% +the film if if many people's principal +motivation had to do with + + align:start position:0% +motivation had to do with + + + align:start position:0% +motivation had to do with +um Nazi Germany what happened between + + align:start position:0% +um Nazi Germany what happened between + + + align:start position:0% +um Nazi Germany what happened between +so-called VE Day the the ultimate defeat + + align:start position:0% +so-called VE Day the the ultimate defeat + + + align:start position:0% +so-called VE Day the the ultimate defeat +of the Nazis in April of 1945 uh and the + + align:start position:0% +of the Nazis in April of 1945 uh and the + + + align:start position:0% +of the Nazis in April of 1945 uh and the +and the uh sort of remainder of the + + align:start position:0% +and the uh sort of remainder of the + + + align:start position:0% +and the uh sort of remainder of the +project let alone the use of the weapons + + align:start position:0% +project let alone the use of the weapons + + + align:start position:0% +project let alone the use of the weapons +uh in against Japan so we can we should + + align:start position:0% +uh in against Japan so we can we should + + + align:start position:0% +uh in against Japan so we can we should +come back to that but nonetheless I + + align:start position:0% +come back to that but nonetheless I + + + align:start position:0% +come back to that but nonetheless I +think people felt strongly they wanted + + align:start position:0% +think people felt strongly they wanted + + + align:start position:0% +think people felt strongly they wanted +to do something uh many people did even + + align:start position:0% +to do something uh many people did even + + + align:start position:0% +to do something uh many people did even +very young people + + align:start position:0% +very young people + + + align:start position:0% +very young people +and this was a decision formed without + + align:start position:0% +and this was a decision formed without + + + align:start position:0% +and this was a decision formed without +full information right because often + + align:start position:0% +full information right because often + + + align:start position:0% +full information right because often +that literally couldn't be brief we I we + + align:start position:0% +that literally couldn't be brief we I we + + + align:start position:0% +that literally couldn't be brief we I we +talked last time about these + + align:start position:0% +talked last time about these + + + align:start position:0% +talked last time about these +um the so-called indoctrination course + + align:start position:0% +um the so-called indoctrination course + + + align:start position:0% +um the so-called indoctrination course +that Robert cerber gave once they + + align:start position:0% +that Robert cerber gave once they + + + align:start position:0% +that Robert cerber gave once they +actually arrived at Los Alamos uh for + + align:start position:0% +actually arrived at Los Alamos uh for + + + align:start position:0% +actually arrived at Los Alamos uh for +some of them that was he had to tell + + align:start position:0% +some of them that was he had to tell + + + align:start position:0% +some of them that was he had to tell +them oh we gathered here to build a bomb + + align:start position:0% +them oh we gathered here to build a bomb + + + align:start position:0% +them oh we gathered here to build a bomb +like he first had to say that because it + + align:start position:0% +like he first had to say that because it + + + align:start position:0% +like he first had to say that because it +wasn't might not have been obvious to + + align:start position:0% +wasn't might not have been obvious to + + + align:start position:0% +wasn't might not have been obvious to +everyone yet uh when they gathered I've + + align:start position:0% +everyone yet uh when they gathered I've + + + align:start position:0% +everyone yet uh when they gathered I've +just learned that extraordinary + + align:start position:0% +just learned that extraordinary + + + align:start position:0% +just learned that extraordinary +um there's a larger question though a + + align:start position:0% +um there's a larger question though a + + + align:start position:0% +um there's a larger question though a +larger thing that that a actually a good + + align:start position:0% +larger thing that that a actually a good + + + align:start position:0% +larger thing that that a actually a good +friend of mine historian Michael Gordon + + align:start position:0% +friend of mine historian Michael Gordon + + + align:start position:0% +friend of mine historian Michael Gordon +has written a really interesting short + + align:start position:0% +has written a really interesting short + + + align:start position:0% +has written a really interesting short +book about + + align:start position:0% +book about + + + align:start position:0% +book about +um the book is called five days in + + align:start position:0% +um the book is called five days in + + + align:start position:0% +um the book is called five days in +August which comes to another aspect of + + align:start position:0% +August which comes to another aspect of + + + align:start position:0% +August which comes to another aspect of +your question which is how did many + + align:start position:0% +your question which is how did many + + + align:start position:0% +your question which is how did many +people scientists on the project uh + + align:start position:0% +people scientists on the project uh + + + align:start position:0% +people scientists on the project uh +military officials political leaders uh + + align:start position:0% +military officials political leaders uh + + + align:start position:0% +military officials political leaders uh +any uh journalists other policy makers + + align:start position:0% +any uh journalists other policy makers + + + align:start position:0% +any uh journalists other policy makers +how did Hulk how did many different + + align:start position:0% +how did Hulk how did many different + + + align:start position:0% +how did Hulk how did many different +kinds of people + + align:start position:0% +kinds of people + + + align:start position:0% +kinds of people +come to think about the bomb once they + + align:start position:0% +come to think about the bomb once they + + + align:start position:0% +come to think about the bomb once they +learned about it + + align:start position:0% +learned about it + + + align:start position:0% +learned about it +and Michael's argument in brief let's + + align:start position:0% +and Michael's argument in brief let's + + + align:start position:0% +and Michael's argument in brief let's +see if I do justice to it again that + + align:start position:0% +see if I do justice to it again that + + + align:start position:0% +see if I do justice to it again that +some of the Tas knows but very very well + + align:start position:0% +some of the Tas knows but very very well + + + align:start position:0% +some of the Tas knows but very very well +so they should correct me but my + + align:start position:0% +so they should correct me but my + + + align:start position:0% +so they should correct me but my +recollection of my friend's book + + align:start position:0% +recollection of my friend's book + + + align:start position:0% +recollection of my friend's book +um is is more or less the following + + align:start position:0% +um is is more or less the following + + + align:start position:0% +um is is more or less the following +that the the bomb was treated by many + + align:start position:0% +that the the bomb was treated by many + + + align:start position:0% +that the the bomb was treated by many +many of these folks as not particularly + + align:start position:0% +many of these folks as not particularly + + + align:start position:0% +many of these folks as not particularly +unusual or special prior to its use + + align:start position:0% +unusual or special prior to its use + + + align:start position:0% +unusual or special prior to its use +uh and and my my favorite parts of + + align:start position:0% +uh and and my my favorite parts of + + + align:start position:0% +uh and and my my favorite parts of +Michael's book actually have to do with + + align:start position:0% +Michael's book actually have to do with + + + align:start position:0% +Michael's book actually have to do with +the mechanics of how the how the weapons + + align:start position:0% +the mechanics of how the how the weapons + + + align:start position:0% +the mechanics of how the how the weapons +were literally put together and then + + align:start position:0% +were literally put together and then + + + align:start position:0% +were literally put together and then +kind of armed for use uh in in + + align:start position:0% +kind of armed for use uh in in + + + align:start position:0% +kind of armed for use uh in in +um against Targets in Japan so on the + + align:start position:0% +um against Targets in Japan so on the + + + align:start position:0% +um against Targets in Japan so on the +island of tinian there's some some + + align:start position:0% +island of tinian there's some some + + + align:start position:0% +island of tinian there's some some +footage in the film + + align:start position:0% +footage in the film + + + align:start position:0% +footage in the film +of the kind of staging grounds on tinian + + align:start position:0% +of the kind of staging grounds on tinian + + + align:start position:0% +of the kind of staging grounds on tinian +and my understanding is it's not that + + align:start position:0% +and my understanding is it's not that + + + align:start position:0% +and my understanding is it's not that +President Truman the U.S President + + align:start position:0% +President Truman the U.S President + + + align:start position:0% +President Truman the U.S President +Truman gave direct orders every time to + + align:start position:0% +Truman gave direct orders every time to + + + align:start position:0% +Truman gave direct orders every time to +say drop a bomb now on Hiroshima drop a + + align:start position:0% +say drop a bomb now on Hiroshima drop a + + + align:start position:0% +say drop a bomb now on Hiroshima drop a +bomb now on Nagasaki there was no such + + align:start position:0% +bomb now on Nagasaki there was no such + + + align:start position:0% +bomb now on Nagasaki there was no such +order given not that specific + + align:start position:0% +order given not that specific + + + align:start position:0% +order given not that specific +the decision was made + + align:start position:0% +the decision was made + + + align:start position:0% +the decision was made +to use the weapons when they were + + align:start position:0% +to use the weapons when they were + + + align:start position:0% +to use the weapons when they were +available up to the discretion of the + + align:start position:0% +available up to the discretion of the + + + align:start position:0% +available up to the discretion of the +field commanders just like every other + + align:start position:0% +field commanders just like every other + + + align:start position:0% +field commanders just like every other +kind of weapons every other kind of + + align:start position:0% +kind of weapons every other kind of + + + align:start position:0% +kind of weapons every other kind of +bombing + + align:start position:0% +bombing + + + align:start position:0% +bombing +again as there was some uh footage in + + align:start position:0% +again as there was some uh footage in + + + align:start position:0% +again as there was some uh footage in +the film and others might you might + + align:start position:0% +the film and others might you might + + + align:start position:0% +the film and others might you might +already have known there had been uh + + align:start position:0% +already have known there had been uh + + + align:start position:0% +already have known there had been uh +campaigns of of um what was called + + align:start position:0% +campaigns of of um what was called + + + align:start position:0% +campaigns of of um what was called +incendiary bombing using certain kinds + + align:start position:0% +incendiary bombing using certain kinds + + + align:start position:0% +incendiary bombing using certain kinds +of conventional explosives that were + + align:start position:0% +of conventional explosives that were + + + align:start position:0% +of conventional explosives that were +especially likely to cause ground fires + + align:start position:0% +especially likely to cause ground fires + + + align:start position:0% +especially likely to cause ground fires +um against uh some cities in Europe but + + align:start position:0% +um against uh some cities in Europe but + + + align:start position:0% +um against uh some cities in Europe but +but many cities in Japan by the Ally Air + + align:start position:0% +but many cities in Japan by the Ally Air + + + align:start position:0% +but many cities in Japan by the Ally Air +Forces U.S particular + + align:start position:0% +Forces U.S particular + + + align:start position:0% +Forces U.S particular +uh and those weren't sort of separately + + align:start position:0% +uh and those weren't sort of separately + + + align:start position:0% +uh and those weren't sort of separately +ordered from on high they were field + + align:start position:0% +ordered from on high they were field + + + align:start position:0% +ordered from on high they were field +there was a chain of command in the + + align:start position:0% +there was a chain of command in the + + + align:start position:0% +there was a chain of command in the +field so to speak and up to their expert + + align:start position:0% +field so to speak and up to their expert + + + align:start position:0% +field so to speak and up to their expert +judgment uh where the conditions right + + align:start position:0% +judgment uh where the conditions right + + + align:start position:0% +judgment uh where the conditions right +is there a storm coming should they + + align:start position:0% +is there a storm coming should they + + + align:start position:0% +is there a storm coming should they +launch you know a series of bombing + + align:start position:0% +launch you know a series of bombing + + + align:start position:0% +launch you know a series of bombing +raids or not that was not a presidential + + align:start position:0% +raids or not that was not a presidential + + + align:start position:0% +raids or not that was not a presidential +level decision or even necessarily a + + align:start position:0% +level decision or even necessarily a + + + align:start position:0% +level decision or even necessarily a +general's level position that was kind + + align:start position:0% +general's level position that was kind + + + align:start position:0% +general's level position that was kind +of outsourced to the to the rank ranking + + align:start position:0% +of outsourced to the to the rank ranking + + + align:start position:0% +of outsourced to the to the rank ranking +officers in the field and what + + align:start position:0% +officers in the field and what + + + align:start position:0% +officers in the field and what +astonishes me what Michael found is that + + align:start position:0% +astonishes me what Michael found is that + + + align:start position:0% +astonishes me what Michael found is that +the in the earliest stages the nuclear + + align:start position:0% +the in the earliest stages the nuclear + + + align:start position:0% +the in the earliest stages the nuclear +weapons were treated like that they were + + align:start position:0% +weapons were treated like that they were + + + align:start position:0% +weapons were treated like that they were +they were plugged into an existing + + align:start position:0% +they were plugged into an existing + + + align:start position:0% +they were plugged into an existing +system of local decision making about + + align:start position:0% +system of local decision making about + + + align:start position:0% +system of local decision making about +when to use them under what + + align:start position:0% +when to use them under what + + + align:start position:0% +when to use them under what +circumstances and that Michael suggests + + align:start position:0% +circumstances and that Michael suggests + + + align:start position:0% +circumstances and that Michael suggests +shows that they were not treated as a + + align:start position:0% +shows that they were not treated as a + + + align:start position:0% +shows that they were not treated as a +sort of separate category early on they + + align:start position:0% +sort of separate category early on they + + + align:start position:0% +sort of separate category early on they +were treated like another weapon there + + align:start position:0% +were treated like another weapon there + + + align:start position:0% +were treated like another weapon there +have been many other kinds of weapons + + align:start position:0% +have been many other kinds of weapons + + + align:start position:0% +have been many other kinds of weapons +developed and deployed sort of from + + align:start position:0% +developed and deployed sort of from + + + align:start position:0% +developed and deployed sort of from +scratch in the course of the war and + + align:start position:0% +scratch in the course of the war and + + + align:start position:0% +scratch in the course of the war and +that these were kind of treated at least + + align:start position:0% +that these were kind of treated at least + + + align:start position:0% +that these were kind of treated at least +logistically or or + + align:start position:0% +logistically or or + + + align:start position:0% +logistically or or +um kind of bureaucratically + + align:start position:0% +um kind of bureaucratically + + + align:start position:0% +um kind of bureaucratically +like you know like yet another weapon to + + align:start position:0% +like you know like yet another weapon to + + + align:start position:0% +like you know like yet another weapon to +be deployed + + align:start position:0% +be deployed + + + align:start position:0% +be deployed +uh largely at the kind of discretion of + + align:start position:0% +uh largely at the kind of discretion of + + + align:start position:0% +uh largely at the kind of discretion of +the of the local + + align:start position:0% +the of the local + + + align:start position:0% +the of the local +um kind of field Commanders + + align:start position:0% +um kind of field Commanders + + + align:start position:0% +um kind of field Commanders +um and that + + align:start position:0% +um and that + + + align:start position:0% +um and that +the standing so they said there was a + + align:start position:0% +the standing so they said there was a + + + align:start position:0% +the standing so they said there was a +standing order at all it was use them + + align:start position:0% +standing order at all it was use them + + + align:start position:0% +standing order at all it was use them +when you got them it wasn't like drop + + align:start position:0% +when you got them it wasn't like drop + + + align:start position:0% +when you got them it wasn't like drop +one wait three days there was no such + + align:start position:0% +one wait three days there was no such + + + align:start position:0% +one wait three days there was no such +there was no such coordination of that + + align:start position:0% +there was no such coordination of that + + + align:start position:0% +there was no such coordination of that +level + + align:start position:0% +level + + + align:start position:0% +level +and in fact there was no third bomb + + align:start position:0% +and in fact there was no third bomb + + + align:start position:0% +and in fact there was no third bomb +ready the two were dropped the bomb + + align:start position:0% +ready the two were dropped the bomb + + + align:start position:0% +ready the two were dropped the bomb +dropped against Nagasaki was and they + + align:start position:0% +dropped against Nagasaki was and they + + + align:start position:0% +dropped against Nagasaki was and they +get a little bit of this in the film was + + align:start position:0% +get a little bit of this in the film was + + + align:start position:0% +get a little bit of this in the film was +uh the schedule was pushed up by the + + align:start position:0% +uh the schedule was pushed up by the + + + align:start position:0% +uh the schedule was pushed up by the +local field commanders because there was + + align:start position:0% +local field commanders because there was + + + align:start position:0% +local field commanders because there was +a worried about severe weather a kind of + + align:start position:0% +a worried about severe weather a kind of + + + align:start position:0% +a worried about severe weather a kind of +typhoon coming it would have threatened + + align:start position:0% +typhoon coming it would have threatened + + + align:start position:0% +typhoon coming it would have threatened +certain kinds of um uh you know aircraft + + align:start position:0% +certain kinds of um uh you know aircraft + + + align:start position:0% +certain kinds of um uh you know aircraft +runs + + align:start position:0% +runs + + + align:start position:0% +runs +so uh so and in fact nagasaka wasn't + + align:start position:0% +so uh so and in fact nagasaka wasn't + + + align:start position:0% +so uh so and in fact nagasaka wasn't +even the original Target City there was + + align:start position:0% +even the original Target City there was + + + align:start position:0% +even the original Target City there was +a decision made by the by the pilot in + + align:start position:0% +a decision made by the by the pilot in + + + align:start position:0% +a decision made by the by the pilot in +mid-flight to change path I think + + align:start position:0% +mid-flight to change path I think + + + align:start position:0% +mid-flight to change path I think +largely because of things like changing + + align:start position:0% +largely because of things like changing + + + align:start position:0% +largely because of things like changing +conditions in the weather and so on so + + align:start position:0% +conditions in the weather and so on so + + + align:start position:0% +conditions in the weather and so on so +these were not highly staged or high + + align:start position:0% +these were not highly staged or high + + + align:start position:0% +these were not highly staged or high +these are not highly + + align:start position:0% +these are not highly + + + align:start position:0% +these are not highly +um + + align:start position:0% +um + + + align:start position:0% +um +kind of carefully thought out and vetted + + align:start position:0% +kind of carefully thought out and vetted + + + align:start position:0% +kind of carefully thought out and vetted +individual decisions the decision was + + align:start position:0% +individual decisions the decision was + + + align:start position:0% +individual decisions the decision was +load them into the planes and drop them + + align:start position:0% +load them into the planes and drop them + + + align:start position:0% +load them into the planes and drop them +when you got him and they had two the + + align:start position:0% +when you got him and they had two the + + + align:start position:0% +when you got him and they had two the +the makings for a third not yet compiled + + align:start position:0% +the makings for a third not yet compiled + + + align:start position:0% +the makings for a third not yet compiled +weapon were literally on a boat making + + align:start position:0% +weapon were literally on a boat making + + + align:start position:0% +weapon were literally on a boat making +their way to tinian at the time that uh + + align:start position:0% +their way to tinian at the time that uh + + + align:start position:0% +their way to tinian at the time that uh +that Japan surrendered so they do is + + align:start position:0% +that Japan surrendered so they do is + + + align:start position:0% +that Japan surrendered so they do is +drop us drop them and one after the + + align:start position:0% +drop us drop them and one after the + + + align:start position:0% +drop us drop them and one after the +other much like the incendiary bombing + + align:start position:0% +other much like the incendiary bombing + + + align:start position:0% +other much like the incendiary bombing +rates have been you know kind of uh one + + align:start position:0% +rates have been you know kind of uh one + + + align:start position:0% +rates have been you know kind of uh one +after the other + + align:start position:0% +after the other + + + align:start position:0% +after the other +um and what what Michael and others have + + align:start position:0% +um and what what Michael and others have + + + align:start position:0% +um and what what Michael and others have +argued what made it seem what made the + + align:start position:0% +argued what made it seem what made the + + + align:start position:0% +argued what made it seem what made the +atomic weapon seem special was the fact + + align:start position:0% +atomic weapon seem special was the fact + + + align:start position:0% +atomic weapon seem special was the fact +that the fighting stopped which was not + + align:start position:0% +that the fighting stopped which was not + + + align:start position:0% +that the fighting stopped which was not +necessarily predicted uh no one thought + + align:start position:0% +necessarily predicted uh no one thought + + + align:start position:0% +necessarily predicted uh no one thought +you'd drop one and they'll stop or at + + align:start position:0% +you'd drop one and they'll stop or at + + + align:start position:0% +you'd drop one and they'll stop or at +least no one seems to have thought that + + align:start position:0% +least no one seems to have thought that + + + align:start position:0% +least no one seems to have thought that +no one thought if we time the other one + + align:start position:0% +no one thought if we time the other one + + + align:start position:0% +no one thought if we time the other one +very carefully that'll convince them + + align:start position:0% +very carefully that'll convince them + + + align:start position:0% +very carefully that'll convince them +there was no such calculation for the + + align:start position:0% +there was no such calculation for the + + + align:start position:0% +there was no such calculation for the +timing of of the second bomb that was + + align:start position:0% +timing of of the second bomb that was + + + align:start position:0% +timing of of the second bomb that was +used in this case against Nagasaki and + + align:start position:0% +used in this case against Nagasaki and + + + align:start position:0% +used in this case against Nagasaki and +they were prepared they were preparing + + align:start position:0% +they were prepared they were preparing + + + align:start position:0% +they were prepared they were preparing +to drop a third one and they would have + + align:start position:0% +to drop a third one and they would have + + + align:start position:0% +to drop a third one and they would have +dropped a fourth if they had one they + + align:start position:0% +dropped a fourth if they had one they + + + align:start position:0% +dropped a fourth if they had one they +just didn't literally didn't have the + + align:start position:0% +just didn't literally didn't have the + + + align:start position:0% +just didn't literally didn't have the +parts + + align:start position:0% +parts + + + align:start position:0% +parts +um + + align:start position:0% +um + + + align:start position:0% +um +so Michael argues it was actually uh in + + align:start position:0% +so Michael argues it was actually uh in + + + align:start position:0% +so Michael argues it was actually uh in +response to the fact that unlike other + + align:start position:0% +response to the fact that unlike other + + + align:start position:0% +response to the fact that unlike other +military campaigns there was at least a + + align:start position:0% +military campaigns there was at least a + + + align:start position:0% +military campaigns there was at least a +coincidence in time this time around + + align:start position:0% +coincidence in time this time around + + + align:start position:0% +coincidence in time this time around +that Japan did surrender within days of + + align:start position:0% +that Japan did surrender within days of + + + align:start position:0% +that Japan did surrender within days of +the second bombing that then in kind of + + align:start position:0% +the second bombing that then in kind of + + + align:start position:0% +the second bombing that then in kind of +a post-hoc rationalization according to + + align:start position:0% +a post-hoc rationalization according to + + + align:start position:0% +a post-hoc rationalization according to +Michael kind of made people think that + + align:start position:0% +Michael kind of made people think that + + + align:start position:0% +Michael kind of made people think that +the atomic weapons were now somehow in + + align:start position:0% +the atomic weapons were now somehow in + + + align:start position:0% +the atomic weapons were now somehow in +the category of their own or different + + align:start position:0% +the category of their own or different + + + align:start position:0% +the category of their own or different +or special it was a long answer it's a + + align:start position:0% +or special it was a long answer it's a + + + align:start position:0% +or special it was a long answer it's a +very complicated question + + align:start position:0% +very complicated question + + + align:start position:0% +very complicated question +um I think a bunch of the scientists who + + align:start position:0% +um I think a bunch of the scientists who + + + align:start position:0% +um I think a bunch of the scientists who +work for example on Los Alamos scientist + + align:start position:0% +work for example on Los Alamos scientist + + + align:start position:0% +work for example on Los Alamos scientist +Engineers I think they thought this was + + align:start position:0% +Engineers I think they thought this was + + + align:start position:0% +Engineers I think they thought this was +different early on and some of their + + align:start position:0% +different early on and some of their + + + align:start position:0% +different early on and some of their +concerns we hear about less so in the + + align:start position:0% +concerns we hear about less so in the + + + align:start position:0% +concerns we hear about less so in the +film but other reminiscences and + + align:start position:0% +film but other reminiscences and + + + align:start position:0% +film but other reminiscences and +interviews and so on Memoir has been + + align:start position:0% +interviews and so on Memoir has been + + + align:start position:0% +interviews and so on Memoir has been +published is that they were often quite + + align:start position:0% +published is that they were often quite + + + align:start position:0% +published is that they were often quite +concerned that some of the + + align:start position:0% +concerned that some of the + + + align:start position:0% +concerned that some of the +uh army figures the military figures who + + align:start position:0% +uh army figures the military figures who + + + align:start position:0% +uh army figures the military figures who +also witnessed for example the Trinity + + align:start position:0% +also witnessed for example the Trinity + + + align:start position:0% +also witnessed for example the Trinity +test were not as shocked as the + + align:start position:0% +test were not as shocked as the + + + align:start position:0% +test were not as shocked as the +scientists were + + align:start position:0% +scientists were + + + align:start position:0% +scientists were +I think I mentioned very very briefly in + + align:start position:0% +I think I mentioned very very briefly in + + + align:start position:0% +I think I mentioned very very briefly in +my previous lecture + + align:start position:0% +my previous lecture + + + align:start position:0% +my previous lecture +that for the Trinity test in um + + align:start position:0% +that for the Trinity test in um + + + align:start position:0% +that for the Trinity test in um +Alamogordo New Mexico one of the things + + align:start position:0% +Alamogordo New Mexico one of the things + + + align:start position:0% +Alamogordo New Mexico one of the things +that really really seems to have left a + + align:start position:0% +that really really seems to have left a + + + align:start position:0% +that really really seems to have left a +visceral reaction to many of the folks + + align:start position:0% +visceral reaction to many of the folks + + + align:start position:0% +visceral reaction to many of the folks +who then were able to inspect the the + + align:start position:0% +who then were able to inspect the the + + + align:start position:0% +who then were able to inspect the the +the + + align:start position:0% +the + + + align:start position:0% +the +soon called be called Ground Zero was + + align:start position:0% +soon called be called Ground Zero was + + + align:start position:0% +soon called be called Ground Zero was +that the the Heat and especially + + align:start position:0% +that the the Heat and especially + + + align:start position:0% +that the the Heat and especially +pressure of the blast had fused desert + + align:start position:0% +pressure of the blast had fused desert + + + align:start position:0% +pressure of the blast had fused desert +sand in the glass and that at least is + + align:start position:0% +sand in the glass and that at least is + + + align:start position:0% +sand in the glass and that at least is +some of these scientists later recalled + + align:start position:0% +some of these scientists later recalled + + + align:start position:0% +some of these scientists later recalled +that gave them a kind of visceral sense + + align:start position:0% +that gave them a kind of visceral sense + + + align:start position:0% +that gave them a kind of visceral sense +of the forces at play and then they were + + align:start position:0% +of the forces at play and then they were + + + align:start position:0% +of the forces at play and then they were +some of them report being equally + + align:start position:0% +some of them report being equally + + + align:start position:0% +some of them report being equally +viscerally upset that the generals + + align:start position:0% +viscerally upset that the generals + + + align:start position:0% +viscerally upset that the generals +weren't impressed by that so so some of + + align:start position:0% +weren't impressed by that so so some of + + + align:start position:0% +weren't impressed by that so so some of +the scientists seem to think we are + + align:start position:0% +the scientists seem to think we are + + + align:start position:0% +the scientists seem to think we are +playing with the forces that power the + + align:start position:0% +playing with the forces that power the + + + align:start position:0% +playing with the forces that power the +sun where we're dealing with + + align:start position:0% +sun where we're dealing with + + + align:start position:0% +sun where we're dealing with +extraordinarily powerful physical + + align:start position:0% +extraordinarily powerful physical + + + align:start position:0% +extraordinarily powerful physical +phenomena and so at least in their later + + align:start position:0% +phenomena and so at least in their later + + + align:start position:0% +phenomena and so at least in their later +Recollections they seem to have treated + + align:start position:0% +Recollections they seem to have treated + + + align:start position:0% +Recollections they seem to have treated +this as different not just another TNT + + align:start position:0% +this as different not just another TNT + + + align:start position:0% +this as different not just another TNT +bomb souped up and therefore they were + + align:start position:0% +bomb souped up and therefore they were + + + align:start position:0% +bomb souped up and therefore they were +concerned that others didn't treat it + + align:start position:0% +concerned that others didn't treat it + + + align:start position:0% +concerned that others didn't treat it +with a similar kind of differentness + + align:start position:0% +with a similar kind of differentness + + + align:start position:0% +with a similar kind of differentness +but I'm pretty convinced by Michael's + + align:start position:0% +but I'm pretty convinced by Michael's + + + align:start position:0% +but I'm pretty convinced by Michael's +argument more broadly if you look at the + + align:start position:0% +argument more broadly if you look at the + + + align:start position:0% +argument more broadly if you look at the +kind of + + align:start position:0% +kind of + + + align:start position:0% +kind of +political high-level political apparatus + + align:start position:0% +political high-level political apparatus + + + align:start position:0% +political high-level political apparatus +and the military planning and war + + align:start position:0% +and the military planning and war + + + align:start position:0% +and the military planning and war +department apparatus this was treated at + + align:start position:0% +department apparatus this was treated at + + + align:start position:0% +department apparatus this was treated at +least bureaucratically in terms of like + + align:start position:0% +least bureaucratically in terms of like + + + align:start position:0% +least bureaucratically in terms of like +standing orders as such much more like + + align:start position:0% +standing orders as such much more like + + + align:start position:0% +standing orders as such much more like +the next thing in the Arsenal to drop as + + align:start position:0% +the next thing in the Arsenal to drop as + + + align:start position:0% +the next thing in the Arsenal to drop as +opposed to some total separate category + + align:start position:0% +opposed to some total separate category + + + align:start position:0% +opposed to some total separate category +in itself + + align:start position:0% +in itself + + + align:start position:0% +in itself +if anyone else has any thoughts on that + + align:start position:0% +if anyone else has any thoughts on that + + + align:start position:0% +if anyone else has any thoughts on that +but that's my not very brief take on on + + align:start position:0% +but that's my not very brief take on on + + + align:start position:0% +but that's my not very brief take on on +that very juicy question it's a good + + align:start position:0% +that very juicy question it's a good + + + align:start position:0% +that very juicy question it's a good +question + + align:start position:0% + + + + align:start position:0% + +right that's thank you Stephen that's + + align:start position:0% +right that's thank you Stephen that's + + + align:start position:0% +right that's thank you Stephen that's +also a really hard question it's a good + + align:start position:0% +also a really hard question it's a good + + + align:start position:0% +also a really hard question it's a good +important question a hard one + + align:start position:0% +important question a hard one + + + align:start position:0% +important question a hard one +um so and we I talked a little bit about + + align:start position:0% +um so and we I talked a little bit about + + + align:start position:0% +um so and we I talked a little bit about +this in a previous class session but + + align:start position:0% +this in a previous class session but + + + align:start position:0% +this in a previous class session but +it's um but it's worth revisiting + + align:start position:0% +it's um but it's worth revisiting + + + align:start position:0% +it's um but it's worth revisiting +so the short answer is many of these + + align:start position:0% +so the short answer is many of these + + + align:start position:0% +so the short answer is many of these +folks were aware as I say the scientists + + align:start position:0% +folks were aware as I say the scientists + + + align:start position:0% +folks were aware as I say the scientists +engineers let's say we're definitely + + align:start position:0% +engineers let's say we're definitely + + + align:start position:0% +engineers let's say we're definitely +aware that there was going to be + + align:start position:0% +aware that there was going to be + + + align:start position:0% +aware that there was going to be +Associated radiation and Fallout and + + align:start position:0% +Associated radiation and Fallout and + + + align:start position:0% +Associated radiation and Fallout and +that would not be good for people right + + align:start position:0% +that would not be good for people right + + + align:start position:0% +that would not be good for people right +they knew there was an inherent clear + + align:start position:0% +they knew there was an inherent clear + + + align:start position:0% +they knew there was an inherent clear +danger there was not like + + align:start position:0% +danger there was not like + + + align:start position:0% +danger there was not like +um you know TNT or other conventional + + align:start position:0% +um you know TNT or other conventional + + + align:start position:0% +um you know TNT or other conventional +explosives that really did strike many + + align:start position:0% +explosives that really did strike many + + + align:start position:0% +explosives that really did strike many +of them as being importantly different + + align:start position:0% +of them as being importantly different + + + align:start position:0% +of them as being importantly different +they did not have anything like the + + align:start position:0% +they did not have anything like the + + + align:start position:0% +they did not have anything like the +sophisticated + + align:start position:0% +sophisticated + + + align:start position:0% +sophisticated +large-scale statistically powerful you + + align:start position:0% +large-scale statistically powerful you + + + align:start position:0% +large-scale statistically powerful you +know controlled medical experimentation + + align:start position:0% +know controlled medical experimentation + + + align:start position:0% +know controlled medical experimentation +type results + + align:start position:0% +type results + + + align:start position:0% +type results +or body of knowledge that would develop + + align:start position:0% +or body of knowledge that would develop + + + align:start position:0% +or body of knowledge that would develop +um later so they didn't have I mean it + + align:start position:0% +um later so they didn't have I mean it + + + align:start position:0% +um later so they didn't have I mean it +would be on we shouldn't expect them to + + align:start position:0% +would be on we shouldn't expect them to + + + align:start position:0% +would be on we shouldn't expect them to +have the same knowledge about them + + align:start position:0% +have the same knowledge about them + + + align:start position:0% +have the same knowledge about them +human biological implications of Fallout + + align:start position:0% +human biological implications of Fallout + + + align:start position:0% +human biological implications of Fallout +as we as the community would later + + align:start position:0% +as we as the community would later + + + align:start position:0% +as we as the community would later +acquire largely from the use of these + + align:start position:0% +acquire largely from the use of these + + + align:start position:0% +acquire largely from the use of these +weapons and from other kinds of tests so + + align:start position:0% +weapons and from other kinds of tests so + + + align:start position:0% +weapons and from other kinds of tests so +they didn't know what would later be + + align:start position:0% +they didn't know what would later be + + + align:start position:0% +they didn't know what would later be +known they knew something + + align:start position:0% +known they knew something + + + align:start position:0% +known they knew something +they do enough to to treat it very + + align:start position:0% +they do enough to to treat it very + + + align:start position:0% +they do enough to to treat it very +relatively carefully + + align:start position:0% +relatively carefully + + + align:start position:0% +relatively carefully +it is yeah they're aware to it that + + align:start position:0% +it is yeah they're aware to it that + + + align:start position:0% +it is yeah they're aware to it that +that's at least a likely possibility on + + align:start position:0% +that's at least a likely possibility on + + + align:start position:0% +that's at least a likely possibility on +the other hand they were pretty Cavalier + + align:start position:0% +the other hand they were pretty Cavalier + + + align:start position:0% +the other hand they were pretty Cavalier +even with their own personal safety so + + align:start position:0% +even with their own personal safety so + + + align:start position:0% +even with their own personal safety so +for example uh one of my well I think I + + align:start position:0% +for example uh one of my well I think I + + + align:start position:0% +for example uh one of my well I think I +mentioned briefly one of my college + + align:start position:0% +mentioned briefly one of my college + + + align:start position:0% +mentioned briefly one of my college +professors who had just retired before I + + align:start position:0% +professors who had just retired before I + + + align:start position:0% +professors who had just retired before I +started college 10 000 years ago + + align:start position:0% +started college 10 000 years ago + + + align:start position:0% +started college 10 000 years ago +approximately uh he had served as a very + + align:start position:0% +approximately uh he had served as a very + + + align:start position:0% +approximately uh he had served as a very +young kid on the Manhattan Project I + + align:start position:0% +young kid on the Manhattan Project I + + + align:start position:0% +young kid on the Manhattan Project I +mean he was like a kid he was basically + + align:start position:0% +mean he was like a kid he was basically + + + align:start position:0% +mean he was like a kid he was basically +a very like a first-year grad student so + + align:start position:0% +a very like a first-year grad student so + + + align:start position:0% +a very like a first-year grad student so +even rtas are more advanced than this + + align:start position:0% +even rtas are more advanced than this + + + align:start position:0% +even rtas are more advanced than this +kid was when he joined the project uh + + align:start position:0% +kid was when he joined the project uh + + + align:start position:0% +kid was when he joined the project uh +and he would say you know they would + + align:start position:0% +and he would say you know they would + + + align:start position:0% +and he would say you know they would +carry little radioactive sources in + + align:start position:0% +carry little radioactive sources in + + + align:start position:0% +carry little radioactive sources in +there like in their like jacket or vest + + align:start position:0% +there like in their like jacket or vest + + + align:start position:0% +there like in their like jacket or vest +Pockets to to calibrate the local you + + align:start position:0% +Pockets to to calibrate the local you + + + align:start position:0% +Pockets to to calibrate the local you +know Machinery so they would put you + + align:start position:0% +know Machinery so they would put you + + + align:start position:0% +know Machinery so they would put you +know Alpha meters next to their gut I + + align:start position:0% +know Alpha meters next to their gut I + + + align:start position:0% +know Alpha meters next to their gut I +don't recommend you do that today like + + align:start position:0% +don't recommend you do that today like + + + align:start position:0% +don't recommend you do that today like +that so so there was a kind of + + align:start position:0% +that so so there was a kind of + + + align:start position:0% +that so so there was a kind of +cavalierness about radioactivity in + + align:start position:0% +cavalierness about radioactivity in + + + align:start position:0% +cavalierness about radioactivity in +general for a lot of these folks partly + + align:start position:0% +general for a lot of these folks partly + + + align:start position:0% +general for a lot of these folks partly +oh there's a war on you don't have time + + align:start position:0% +oh there's a war on you don't have time + + + align:start position:0% +oh there's a war on you don't have time +to be all special and careful but they + + align:start position:0% +to be all special and careful but they + + + align:start position:0% +to be all special and careful but they +didn't know what would later be better + + align:start position:0% +didn't know what would later be better + + + align:start position:0% +didn't know what would later be better +known + + align:start position:0% +known + + + align:start position:0% +known +and then partly for people who are + + align:start position:0% +and then partly for people who are + + + align:start position:0% +and then partly for people who are +working on the project + + align:start position:0% +working on the project + + + align:start position:0% +working on the project +who weren't themselves scientists or + + align:start position:0% +who weren't themselves scientists or + + + align:start position:0% +who weren't themselves scientists or +Engineers there was a really I think um + + align:start position:0% +Engineers there was a really I think um + + + align:start position:0% +Engineers there was a really I think um +very significant lack of effort to + + align:start position:0% +very significant lack of effort to + + + align:start position:0% +very significant lack of effort to +better inform those people about + + align:start position:0% +better inform those people about + + + align:start position:0% +better inform those people about +appropriate safety procedures that based + + align:start position:0% +appropriate safety procedures that based + + + align:start position:0% +appropriate safety procedures that based +on the knowledge that even was in hand + + align:start position:0% +on the knowledge that even was in hand + + + align:start position:0% +on the knowledge that even was in hand +at the time see what I mean and that's + + align:start position:0% +at the time see what I mean and that's + + + align:start position:0% +at the time see what I mean and that's +even before we get to and that's just + + align:start position:0% +even before we get to and that's just + + + align:start position:0% +even before we get to and that's just +for kind of + + align:start position:0% +for kind of + + + align:start position:0% +for kind of +radioactive emitters generally then we + + align:start position:0% +radioactive emitters generally then we + + + align:start position:0% +radioactive emitters generally then we +come to the question of Fallout + + align:start position:0% +come to the question of Fallout + + + align:start position:0% +come to the question of Fallout +specifically from what from the use of + + align:start position:0% +specifically from what from the use of + + + align:start position:0% +specifically from what from the use of +these weapons in a large human + + align:start position:0% +these weapons in a large human + + + align:start position:0% +these weapons in a large human +population + + align:start position:0% +population + + + align:start position:0% +population +and that again they knew enough that it + + align:start position:0% +and that again they knew enough that it + + + align:start position:0% +and that again they knew enough that it +was going to lead to they knew enough to + + align:start position:0% +was going to lead to they knew enough to + + + align:start position:0% +was going to lead to they knew enough to +start studying long-term effects they + + align:start position:0% +start studying long-term effects they + + + align:start position:0% +start studying long-term effects they +figured this would not be good for + + align:start position:0% +figured this would not be good for + + + align:start position:0% +figured this would not be good for +people they didn't have detailed + + align:start position:0% +people they didn't have detailed + + + align:start position:0% +people they didn't have detailed +information about the which cancers at + + align:start position:0% +information about the which cancers at + + + align:start position:0% +information about the which cancers at +what rates what kinds of you know + + align:start position:0% +what rates what kinds of you know + + + align:start position:0% +what rates what kinds of you know +demographics young children affected + + align:start position:0% +demographics young children affected + + + align:start position:0% +demographics young children affected +differently in older people a role of + + align:start position:0% +differently in older people a role of + + + align:start position:0% +differently in older people a role of +pre-existing conditions the kinds of + + align:start position:0% +pre-existing conditions the kinds of + + + align:start position:0% +pre-existing conditions the kinds of +things that kind of biostatisticians + + align:start position:0% +things that kind of biostatisticians + + + align:start position:0% +things that kind of biostatisticians +would would come to study much more + + align:start position:0% +would would come to study much more + + + align:start position:0% +would would come to study much more +carefully later + + align:start position:0% +carefully later + + + align:start position:0% +carefully later +so again that was a pretty long answer + + align:start position:0% +so again that was a pretty long answer + + + align:start position:0% +so again that was a pretty long answer +but they they they were not entirely + + align:start position:0% +but they they they were not entirely + + + align:start position:0% +but they they they were not entirely +ignorant of the dangers of radioactivity + + align:start position:0% +ignorant of the dangers of radioactivity + + + align:start position:0% +ignorant of the dangers of radioactivity +in general or some of the some of the + + align:start position:0% +in general or some of the some of the + + + align:start position:0% +in general or some of the some of the +likely + + align:start position:0% +likely + + + align:start position:0% +likely +um + + align:start position:0% +um + + + align:start position:0% +um +uh implications of of radioactive + + align:start position:0% +uh implications of of radioactive + + + align:start position:0% +uh implications of of radioactive +fallout from the use of these things in + + align:start position:0% +fallout from the use of these things in + + + align:start position:0% +fallout from the use of these things in +a city and they just you know they + + align:start position:0% +a city and they just you know they + + + align:start position:0% +a city and they just you know they +didn't know what what other people would + + align:start position:0% +didn't know what what other people would + + + align:start position:0% +didn't know what what other people would +learn in more detail later + + align:start position:0% + + + + align:start position:0% + +that's a great one I'll just add again + + align:start position:0% +that's a great one I'll just add again + + + align:start position:0% +that's a great one I'll just add again +quickly thank you Tiffany on that point + + align:start position:0% +quickly thank you Tiffany on that point + + + align:start position:0% +quickly thank you Tiffany on that point +too uh coming back maybe just Stephen's + + align:start position:0% +too uh coming back maybe just Stephen's + + + align:start position:0% +too uh coming back maybe just Stephen's +question more directly + + align:start position:0% +question more directly + + + align:start position:0% +question more directly +uh then I didn't mean one directly for + + align:start position:0% +uh then I didn't mean one directly for + + + align:start position:0% +uh then I didn't mean one directly for +me than I did before there was a + + align:start position:0% +me than I did before there was a + + + align:start position:0% +me than I did before there was a +long-term study of people who were who + + align:start position:0% +long-term study of people who were who + + + align:start position:0% +long-term study of people who were who +were um in Hiroshima and Nagasaki at the + + align:start position:0% +were um in Hiroshima and Nagasaki at the + + + align:start position:0% +were um in Hiroshima and Nagasaki at the +time these web the bombs went off + + align:start position:0% +time these web the bombs went off + + + align:start position:0% +time these web the bombs went off +long-term longitudinal study uh largely + + align:start position:0% +long-term longitudinal study uh largely + + + align:start position:0% +long-term longitudinal study uh largely +under U.S auspices so Japan as you may + + align:start position:0% +under U.S auspices so Japan as you may + + + align:start position:0% +under U.S auspices so Japan as you may +know was occupied by the Allied Forces + + align:start position:0% +know was occupied by the Allied Forces + + + align:start position:0% +know was occupied by the Allied Forces +most of the U.S but the sort of allies + + align:start position:0% +most of the U.S but the sort of allies + + + align:start position:0% +most of the U.S but the sort of allies +of World War II + + align:start position:0% +of World War II + + + align:start position:0% +of World War II +for for uh the better part of a decade + + align:start position:0% +for for uh the better part of a decade + + + align:start position:0% +for for uh the better part of a decade +starting uh very soon after surrender so + + align:start position:0% +starting uh very soon after surrender so + + + align:start position:0% +starting uh very soon after surrender so +there were a lot of us-based long-term + + align:start position:0% +there were a lot of us-based long-term + + + align:start position:0% +there were a lot of us-based long-term +studies of the effects of the weapons on + + align:start position:0% +studies of the effects of the weapons on + + + align:start position:0% +studies of the effects of the weapons on +site + + align:start position:0% +site + + + align:start position:0% +site +um including a lot of these kind of + + align:start position:0% +um including a lot of these kind of + + + align:start position:0% +um including a lot of these kind of +biomedical uh kind of epidemiological + + align:start position:0% +biomedical uh kind of epidemiological + + + align:start position:0% +biomedical uh kind of epidemiological +type studies and yet it Still Remains + + align:start position:0% +type studies and yet it Still Remains + + + align:start position:0% +type studies and yet it Still Remains +deeply deeply + + align:start position:0% +deeply deeply + + + align:start position:0% +deeply deeply +um controversial + + align:start position:0% +um controversial + + + align:start position:0% +um controversial +how many deaths to attribute to the + + align:start position:0% +how many deaths to attribute to the + + + align:start position:0% +how many deaths to attribute to the +bombings + + align:start position:0% +bombings + + + align:start position:0% +bombings +partly because of different definitions + + align:start position:0% +partly because of different definitions + + + align:start position:0% +partly because of different definitions +about + + align:start position:0% +about + + + align:start position:0% +about +who who was sort of exposed in what way + + align:start position:0% +who who was sort of exposed in what way + + + align:start position:0% +who who was sort of exposed in what way +partly to the usual difficulties + + align:start position:0% +partly to the usual difficulties + + + align:start position:0% +partly to the usual difficulties +statistically of saying would this many + + align:start position:0% +statistically of saying would this many + + + align:start position:0% +statistically of saying would this many +people have gotten lung cancer even if + + align:start position:0% +people have gotten lung cancer even if + + + align:start position:0% +people have gotten lung cancer even if +they hadn't been exposed to this kind of + + align:start position:0% +they hadn't been exposed to this kind of + + + align:start position:0% +they hadn't been exposed to this kind of +um you know basically pathogen for lack + + align:start position:0% +um you know basically pathogen for lack + + + align:start position:0% +um you know basically pathogen for lack +of better word radioactive source and + + align:start position:0% +of better word radioactive source and + + + align:start position:0% +of better word radioactive source and +also because a lot of the stuff remains + + align:start position:0% +also because a lot of the stuff remains + + + align:start position:0% +also because a lot of the stuff remains +classified or remain classified for a + + align:start position:0% +classified or remain classified for a + + + align:start position:0% +classified or remain classified for a +long long time anyway so we have the com + + align:start position:0% +long long time anyway so we have the com + + + align:start position:0% +long long time anyway so we have the com +one of the things we'll come to a bit in + + align:start position:0% +one of the things we'll come to a bit in + + + align:start position:0% +one of the things we'll come to a bit in +this class we've already got a little + + align:start position:0% +this class we've already got a little + + + align:start position:0% +this class we've already got a little +hint of it is the role of classification + + align:start position:0% +hint of it is the role of classification + + + align:start position:0% +hint of it is the role of classification +in + + align:start position:0% +in + + + align:start position:0% +in +in making it difficult to draw certain + + align:start position:0% +in making it difficult to draw certain + + + align:start position:0% +in making it difficult to draw certain +kinds of conclusions from otherwise very + + align:start position:0% +kinds of conclusions from otherwise very + + + align:start position:0% +kinds of conclusions from otherwise very +complicated scientific and Technical + + align:start position:0% +complicated scientific and Technical + + + align:start position:0% +complicated scientific and Technical +projects uh in this case it was a lot of + + align:start position:0% +projects uh in this case it was a lot of + + + align:start position:0% +projects uh in this case it was a lot of +this stuff was was + + align:start position:0% +this stuff was was + + + align:start position:0% +this stuff was was +subjects who kind of born classified + + align:start position:0% +subjects who kind of born classified + + + align:start position:0% +subjects who kind of born classified +strictures which didn't help with kind + + align:start position:0% +strictures which didn't help with kind + + + align:start position:0% +strictures which didn't help with kind +of independent statisticians redoing the + + align:start position:0% +of independent statisticians redoing the + + + align:start position:0% +of independent statisticians redoing the +stats of the stuff that we would kind of + + align:start position:0% +stats of the stuff that we would kind of + + + align:start position:0% +stats of the stuff that we would kind of +take for granted in in uh kind of + + align:start position:0% +take for granted in in uh kind of + + + align:start position:0% +take for granted in in uh kind of +peer-reviewed scientific studies today + + align:start position:0% +peer-reviewed scientific studies today + + + align:start position:0% +peer-reviewed scientific studies today +so so literally today I'm sure I didn't + + align:start position:0% +so so literally today I'm sure I didn't + + + align:start position:0% +so so literally today I'm sure I didn't +look reasonable but I'm sure if anyone + + align:start position:0% +look reasonable but I'm sure if anyone + + + align:start position:0% +look reasonable but I'm sure if anyone +Google goes on Wikipedia it says how + + align:start position:0% +Google goes on Wikipedia it says how + + + align:start position:0% +Google goes on Wikipedia it says how +many casualties from the bombing of + + align:start position:0% +many casualties from the bombing of + + + align:start position:0% +many casualties from the bombing of +Hiroshima they were probably one of + + align:start position:0% +Hiroshima they were probably one of + + + align:start position:0% +Hiroshima they were probably one of +these like warning comment signs like + + align:start position:0% +these like warning comment signs like + + + align:start position:0% +these like warning comment signs like +people are flaming each other the + + align:start position:0% +people are flaming each other the + + + align:start position:0% +people are flaming each other the +editors don't agree because to this day + + align:start position:0% +editors don't agree because to this day + + + align:start position:0% +editors don't agree because to this day +75 years later asking what sounds like + + align:start position:0% +75 years later asking what sounds like + + + align:start position:0% +75 years later asking what sounds like +what what sounds like a countable + + align:start position:0% +what what sounds like a countable + + + align:start position:0% +what what sounds like a countable +straight seemingly straightforward + + align:start position:0% +straight seemingly straightforward + + + align:start position:0% +straight seemingly straightforward +question how many people were affected + + align:start position:0% +question how many people were affected + + + align:start position:0% +question how many people were affected +killed injured whatever is remarkably + + align:start position:0% +killed injured whatever is remarkably + + + align:start position:0% +killed injured whatever is remarkably +unstrate forward to to very + + align:start position:0% +unstrate forward to to very + + + align:start position:0% +unstrate forward to to very +well-intentioned experts let alone + + align:start position:0% +well-intentioned experts let alone + + + align:start position:0% +well-intentioned experts let alone +people who who are operating for more + + align:start position:0% +people who who are operating for more + + + align:start position:0% +people who who are operating for more +uh from further away from the from the + + align:start position:0% +uh from further away from the from the + + + align:start position:0% +uh from further away from the from the +original information so it gets really + + align:start position:0% +original information so it gets really + + + align:start position:0% +original information so it gets really +tricky to assess literally how many + + align:start position:0% +tricky to assess literally how many + + + align:start position:0% +tricky to assess literally how many +people's lives how many people were + + align:start position:0% +people's lives how many people were + + + align:start position:0% +people's lives how many people were +killed the immediate blast damage that + + align:start position:0% +killed the immediate blast damage that + + + align:start position:0% +killed the immediate blast damage that +actually was uh counted up pretty pretty + + align:start position:0% +actually was uh counted up pretty pretty + + + align:start position:0% +actually was uh counted up pretty pretty +compellingly clearly there's not much + + align:start position:0% +compellingly clearly there's not much + + + align:start position:0% +compellingly clearly there's not much +argument about who died within the first + + align:start position:0% +argument about who died within the first + + + align:start position:0% +argument about who died within the first +week but all these kind of long tail uh + + align:start position:0% +week but all these kind of long tail uh + + + align:start position:0% +week but all these kind of long tail uh +more kind of epidemiological type things + + align:start position:0% +more kind of epidemiological type things + + + align:start position:0% +more kind of epidemiological type things +remain actually quite tricky and and can + + align:start position:0% +remain actually quite tricky and and can + + + align:start position:0% +remain actually quite tricky and and can +Inspire some real + + align:start position:0% +Inspire some real + + + align:start position:0% +Inspire some real +um you know real Earnest debate + + align:start position:0% + + + + align:start position:0% + +yeah it's it's a great Point Lulu and + + align:start position:0% +yeah it's it's a great Point Lulu and + + + align:start position:0% +yeah it's it's a great Point Lulu and +it's again It's Tricky I find it tricky + + align:start position:0% +it's again It's Tricky I find it tricky + + + align:start position:0% +it's again It's Tricky I find it tricky +myself + + align:start position:0% +myself + + + align:start position:0% +myself +um and and just biologically I'm closer + + align:start position:0% +um and and just biologically I'm closer + + + align:start position:0% +um and and just biologically I'm closer +to those times than most of the rest of + + align:start position:0% +to those times than most of the rest of + + + align:start position:0% +to those times than most of the rest of +you but not that much closer + + align:start position:0% +you but not that much closer + + + align:start position:0% +you but not that much closer +um I mean I grew up during the Cold War + + align:start position:0% +um I mean I grew up during the Cold War + + + align:start position:0% +um I mean I grew up during the Cold War +and thinking about I didn't have to do + + align:start position:0% +and thinking about I didn't have to do + + + align:start position:0% +and thinking about I didn't have to do +Duck and Cover drills during like h-bomb + + align:start position:0% +Duck and Cover drills during like h-bomb + + + align:start position:0% +Duck and Cover drills during like h-bomb +raids but you know like my parents did + + align:start position:0% +raids but you know like my parents did + + + align:start position:0% +raids but you know like my parents did +so I heard about it anyway but + + align:start position:0% +so I heard about it anyway but + + + align:start position:0% +so I heard about it anyway but +nonetheless it's hard it's it's hard to + + align:start position:0% +nonetheless it's hard it's it's hard to + + + align:start position:0% +nonetheless it's hard it's it's hard to +get my mind back to a time of of kind of + + align:start position:0% +get my mind back to a time of of kind of + + + align:start position:0% +get my mind back to a time of of kind of +Total War I mean thank goodness right + + align:start position:0% +Total War I mean thank goodness right + + + align:start position:0% +Total War I mean thank goodness right +but if you look at the casualty counts + + align:start position:0% +but if you look at the casualty counts + + + align:start position:0% +but if you look at the casualty counts +the fatality Counts from the incendiary + + align:start position:0% +the fatality Counts from the incendiary + + + align:start position:0% +the fatality Counts from the incendiary +bombings of Tokyo and Dresden + + align:start position:0% +bombings of Tokyo and Dresden + + + align:start position:0% +bombings of Tokyo and Dresden +they very likely exceeded at least the + + align:start position:0% +they very likely exceeded at least the + + + align:start position:0% +they very likely exceeded at least the +short-term casualty Counts from the + + align:start position:0% +short-term casualty Counts from the + + + align:start position:0% +short-term casualty Counts from the +bombings of Hiroshima nagasaka at least + + align:start position:0% +bombings of Hiroshima nagasaka at least + + + align:start position:0% +bombings of Hiroshima nagasaka at least +they were comparable meaning there are + + align:start position:0% +they were comparable meaning there are + + + align:start position:0% +they were comparable meaning there are +there were cities where hundreds of + + align:start position:0% +there were cities where hundreds of + + + align:start position:0% +there were cities where hundreds of +thousands of people were killed by + + align:start position:0% +thousands of people were killed by + + + align:start position:0% +thousands of people were killed by +dropping of weapons from aircraft + + align:start position:0% +dropping of weapons from aircraft + + + align:start position:0% +dropping of weapons from aircraft +multiple times in just the weeks a + + align:start position:0% +multiple times in just the weeks a + + + align:start position:0% +multiple times in just the weeks a +little months before these these these + + align:start position:0% +little months before these these these + + + align:start position:0% +little months before these these these +to our eyes new kinds of weapons were + + align:start position:0% +to our eyes new kinds of weapons were + + + align:start position:0% +to our eyes new kinds of weapons were +used in August at 45. so the scale of + + align:start position:0% +used in August at 45. so the scale of + + + align:start position:0% +used in August at 45. so the scale of +the human cost of Civilian of Total War + + align:start position:0% +the human cost of Civilian of Total War + + + align:start position:0% +the human cost of Civilian of Total War +where it's not people in uniform + + align:start position:0% +where it's not people in uniform + + + align:start position:0% +where it's not people in uniform +fighting on a battlefield but anyone + + align:start position:0% +fighting on a battlefield but anyone + + + align:start position:0% +fighting on a battlefield but anyone +who's within some geographical territory + + align:start position:0% +who's within some geographical territory + + + align:start position:0% +who's within some geographical territory +is suddenly considering kind of fair + + align:start position:0% +is suddenly considering kind of fair + + + align:start position:0% +is suddenly considering kind of fair +game as a Target that wasn't invented + + align:start position:0% +game as a Target that wasn't invented + + + align:start position:0% +game as a Target that wasn't invented +you know with the use of nuclear weapons + + align:start position:0% +you know with the use of nuclear weapons + + + align:start position:0% +you know with the use of nuclear weapons +and and the and the difference that + + align:start position:0% +and and the and the difference that + + + align:start position:0% +and and the and the difference that +sometimes people would would articulate + + align:start position:0% +sometimes people would would articulate + + + align:start position:0% +sometimes people would would articulate +soon afterwards whereas it took a + + align:start position:0% +soon afterwards whereas it took a + + + align:start position:0% +soon afterwards whereas it took a +thousand aircraft to level Tokyo and it + + align:start position:0% +thousand aircraft to level Tokyo and it + + + align:start position:0% +thousand aircraft to level Tokyo and it +took one to level Hiroshima so there was + + align:start position:0% +took one to level Hiroshima so there was + + + align:start position:0% +took one to level Hiroshima so there was +some people would start saying these + + align:start position:0% +some people would start saying these + + + align:start position:0% +some people would start saying these +really are different let's be careful + + align:start position:0% +really are different let's be careful + + + align:start position:0% +really are different let's be careful +let's think about this carefully others + + align:start position:0% +let's think about this carefully others + + + align:start position:0% +let's think about this carefully others +would say + + align:start position:0% +would say + + + align:start position:0% +would say +you know a hundred thousand people dead + + align:start position:0% +you know a hundred thousand people dead + + + align:start position:0% +you know a hundred thousand people dead +that's like last Thursday you know it's + + align:start position:0% +that's like last Thursday you know it's + + + align:start position:0% +that's like last Thursday you know it's +just a remarkable how what what's the + + align:start position:0% +just a remarkable how what what's the + + + align:start position:0% +just a remarkable how what what's the +comparison class let me go to that way + + align:start position:0% +comparison class let me go to that way + + + align:start position:0% +comparison class let me go to that way +what are you comparing it with and how + + align:start position:0% +what are you comparing it with and how + + + align:start position:0% +what are you comparing it with and how +do our own individual sensibilities + + align:start position:0% +do our own individual sensibilities + + + align:start position:0% +do our own individual sensibilities +shift uh compared to um what many folks + + align:start position:0% +shift uh compared to um what many folks + + + align:start position:0% +shift uh compared to um what many folks +were were kind of immersed in at the + + align:start position:0% +were were kind of immersed in at the + + + align:start position:0% +were were kind of immersed in at the +time and I don't say that to to to + + align:start position:0% +time and I don't say that to to to + + + align:start position:0% +time and I don't say that to to to +say there's no culpability I'm just + + align:start position:0% +say there's no culpability I'm just + + + align:start position:0% +say there's no culpability I'm just +saying it's astonishing to me that that + + align:start position:0% +saying it's astonishing to me that that + + + align:start position:0% +saying it's astonishing to me that that +might have seemed + + align:start position:0% +might have seemed + + + align:start position:0% +might have seemed +sort of unremarkable in its day given + + align:start position:0% +sort of unremarkable in its day given + + + align:start position:0% +sort of unremarkable in its day given +given three and a half four years of + + align:start position:0% +given three and a half four years of + + + align:start position:0% +given three and a half four years of +this really devastating civilian heavy + + align:start position:0% +this really devastating civilian heavy + + + align:start position:0% +this really devastating civilian heavy +civilian law so-called Total War + + align:start position:0% +civilian law so-called Total War + + + align:start position:0% +civilian law so-called Total War +um so so I just find that uh I mean + + align:start position:0% +um so so I just find that uh I mean + + + align:start position:0% +um so so I just find that uh I mean +thankfully I don't think I don't think + + align:start position:0% +thankfully I don't think I don't think + + + align:start position:0% +thankfully I don't think I don't think +we have that kind of experience in any + + align:start position:0% +we have that kind of experience in any + + + align:start position:0% +we have that kind of experience in any +of our lifetimes of that kind of um + + align:start position:0% +of our lifetimes of that kind of um + + + align:start position:0% +of our lifetimes of that kind of um +civilian loss of life in in Wartime + + align:start position:0% +civilian loss of life in in Wartime + + + align:start position:0% +civilian loss of life in in Wartime +nothing there's been plenty of bad + + align:start position:0% +nothing there's been plenty of bad + + + align:start position:0% +nothing there's been plenty of bad +things happen since but um so + + align:start position:0% +things happen since but um so + + + align:start position:0% +things happen since but um so +yeah anyway so so that just sort of the + + align:start position:0% +yeah anyway so so that just sort of the + + + align:start position:0% +yeah anyway so so that just sort of the +the scale of of Civilian human loss uh + + align:start position:0% +the scale of of Civilian human loss uh + + + align:start position:0% +the scale of of Civilian human loss uh +where you were you're you were deemed a + + align:start position:0% +where you were you're you were deemed a + + + align:start position:0% +where you were you're you were deemed a +legitimate Target if you happen to live + + align:start position:0% +legitimate Target if you happen to live + + + align:start position:0% +legitimate Target if you happen to live +in a city let alone if you were you know + + align:start position:0% +in a city let alone if you were you know + + + align:start position:0% +in a city let alone if you were you know +drafted let alone if you volunteered or + + align:start position:0% +drafted let alone if you volunteered or + + + align:start position:0% +drafted let alone if you volunteered or +or whatever + + align:start position:0% + + + + align:start position:0% + +again I not not to get ahead of + + align:start position:0% +again I not not to get ahead of + + + align:start position:0% +again I not not to get ahead of +ourselves but for this coming Wednesdays + + align:start position:0% +ourselves but for this coming Wednesdays + + + align:start position:0% +ourselves but for this coming Wednesdays +class session we'll talk about and you + + align:start position:0% +class session we'll talk about and you + + + align:start position:0% +class session we'll talk about and you +get a hint to this in the film as well + + align:start position:0% +get a hint to this in the film as well + + + align:start position:0% +get a hint to this in the film as well +the you know the The Next Step that + + align:start position:0% +the you know the The Next Step that + + + align:start position:0% +the you know the The Next Step that +happened to have been taken in this + + align:start position:0% +happened to have been taken in this + + + align:start position:0% +happened to have been taken in this +thread of discussion was the development + + align:start position:0% +thread of discussion was the development + + + align:start position:0% +thread of discussion was the development +of uh hydrogen weapons + + align:start position:0% +of uh hydrogen weapons + + + align:start position:0% +of uh hydrogen weapons +which you know are roughly speaking a + + align:start position:0% +which you know are roughly speaking a + + + align:start position:0% +which you know are roughly speaking a +thousand plus times more destructive by + + align:start position:0% +thousand plus times more destructive by + + + align:start position:0% +thousand plus times more destructive by +any + + align:start position:0% +any + + + align:start position:0% +any +parameter you choose to measure then + + align:start position:0% +parameter you choose to measure then + + + align:start position:0% +parameter you choose to measure then +then the weapons that had already been + + align:start position:0% +then the weapons that had already been + + + align:start position:0% +then the weapons that had already been +used + + align:start position:0% + + + + align:start position:0% + +right right you know on the question of + + align:start position:0% +right right you know on the question of + + + align:start position:0% +right right you know on the question of +Niels boy it's a great Point Lucas and I + + align:start position:0% +Niels boy it's a great Point Lucas and I + + + align:start position:0% +Niels boy it's a great Point Lucas and I +think it's a it's a lot like somebody + + align:start position:0% +think it's a it's a lot like somebody + + + align:start position:0% +think it's a it's a lot like somebody +talked at least briefly about in a class + + align:start position:0% +talked at least briefly about in a class + + + align:start position:0% +talked at least briefly about in a class +session of maybe two classes ago on + + align:start position:0% +session of maybe two classes ago on + + + align:start position:0% +session of maybe two classes ago on +Einstein's you know very famous letter + + align:start position:0% +Einstein's you know very famous letter + + + align:start position:0% +Einstein's you know very famous letter +to to President Franklin Roosevelt as + + align:start position:0% +to to President Franklin Roosevelt as + + + align:start position:0% +to to President Franklin Roosevelt as +well these are these for a long time + + align:start position:0% +well these are these for a long time + + + align:start position:0% +well these are these for a long time +were held up by scientists as examples + + align:start position:0% +were held up by scientists as examples + + + align:start position:0% +were held up by scientists as examples +of you know these Nobel prize winning + + align:start position:0% +of you know these Nobel prize winning + + + align:start position:0% +of you know these Nobel prize winning +architects of modern physics were also + + align:start position:0% +architects of modern physics were also + + + align:start position:0% +architects of modern physics were also +Geniuses of The Human Condition and + + align:start position:0% +Geniuses of The Human Condition and + + + align:start position:0% +Geniuses of The Human Condition and +political Wizards I wish any of that + + align:start position:0% +political Wizards I wish any of that + + + align:start position:0% +political Wizards I wish any of that +were true and it's not to take away from + + align:start position:0% +were true and it's not to take away from + + + align:start position:0% +were true and it's not to take away from +either einsteiner board to say that + + align:start position:0% +either einsteiner board to say that + + + align:start position:0% +either einsteiner board to say that +those stories are are kind of + + align:start position:0% +those stories are are kind of + + + align:start position:0% +those stories are are kind of +not wishful thinking boar very earnestly + + align:start position:0% +not wishful thinking boar very earnestly + + + align:start position:0% +not wishful thinking boar very earnestly +tried to serve in exactly the capacity + + align:start position:0% +tried to serve in exactly the capacity + + + align:start position:0% +tried to serve in exactly the capacity +you you mentioned because you're quite + + align:start position:0% +you you mentioned because you're quite + + + align:start position:0% +you you mentioned because you're quite +right and the fact is he was + + align:start position:0% +right and the fact is he was + + + align:start position:0% +right and the fact is he was +completely and kind of predictably + + align:start position:0% +completely and kind of predictably + + + align:start position:0% +completely and kind of predictably +ineffective at it no one had any reason + + align:start position:0% +ineffective at it no one had any reason + + + align:start position:0% +ineffective at it no one had any reason +to listen to this mumbling Copenhagen + + align:start position:0% +to listen to this mumbling Copenhagen + + + align:start position:0% +to listen to this mumbling Copenhagen +guy who you know didn't seem to know + + align:start position:0% +guy who you know didn't seem to know + + + align:start position:0% +guy who you know didn't seem to know +anything about about uh how governments + + align:start position:0% +anything about about uh how governments + + + align:start position:0% +anything about about uh how governments +work so his his entries his efforts were + + align:start position:0% +work so his his entries his efforts were + + + align:start position:0% +work so his his entries his efforts were +he did make the efforts let's give him + + align:start position:0% +he did make the efforts let's give him + + + align:start position:0% +he did make the efforts let's give him +credit for that he was indeed he did see + + align:start position:0% +credit for that he was indeed he did see + + + align:start position:0% +credit for that he was indeed he did see +ahead I mean it was it was predictive as + + align:start position:0% +ahead I mean it was it was predictive as + + + align:start position:0% +ahead I mean it was it was predictive as +many people were of a kind of + + align:start position:0% +many people were of a kind of + + + align:start position:0% +many people were of a kind of +um arms race unless there was this + + align:start position:0% +um arms race unless there was this + + + align:start position:0% +um arms race unless there was this +narrow window of opportunity to try to + + align:start position:0% +narrow window of opportunity to try to + + + align:start position:0% +narrow window of opportunity to try to +avert an arms race uh Mutual suspicions + + align:start position:0% +avert an arms race uh Mutual suspicions + + + align:start position:0% +avert an arms race uh Mutual suspicions +uh and distrust growing + + align:start position:0% +uh and distrust growing + + + align:start position:0% +uh and distrust growing +but he I I think I think they were sort + + align:start position:0% +but he I I think I think they were sort + + + align:start position:0% +but he I I think I think they were sort +of very little chance of him having any + + align:start position:0% +of very little chance of him having any + + + align:start position:0% +of very little chance of him having any +actual success and it turns out he had + + align:start position:0% +actual success and it turns out he had + + + align:start position:0% +actual success and it turns out he had +approximately zero success so it's not + + align:start position:0% +approximately zero success so it's not + + + align:start position:0% +approximately zero success so it's not +default him for trying or for + + align:start position:0% +default him for trying or for + + + align:start position:0% +default him for trying or for +recognizing This was + + align:start position:0% +recognizing This was + + + align:start position:0% +recognizing This was +um a likely scenario but we we tend to + + align:start position:0% +um a likely scenario but we we tend to + + + align:start position:0% +um a likely scenario but we we tend to +hear about these stories by like + + align:start position:0% +hear about these stories by like + + + align:start position:0% +hear about these stories by like +biographers of Niels Bohr who who are + + align:start position:0% +biographers of Niels Bohr who who are + + + align:start position:0% +biographers of Niels Bohr who who are +enamorative the many extraordinary + + align:start position:0% +enamorative the many extraordinary + + + align:start position:0% +enamorative the many extraordinary +things that boar was able to do during + + align:start position:0% +things that boar was able to do during + + + align:start position:0% +things that boar was able to do during +his lifetime but if we if we if we ask + + align:start position:0% +his lifetime but if we if we if we ask + + + align:start position:0% +his lifetime but if we if we if we ask +the same question of you know historians + + align:start position:0% +the same question of you know historians + + + align:start position:0% +the same question of you know historians +of U.S foreign relations they'll say + + align:start position:0% +of U.S foreign relations they'll say + + + align:start position:0% +of U.S foreign relations they'll say +Niels who because it had literally zero + + align:start position:0% +Niels who because it had literally zero + + + align:start position:0% +Niels who because it had literally zero +impact you know from at least from where + + align:start position:0% +impact you know from at least from where + + + align:start position:0% +impact you know from at least from where +they're sitting on on the very very + + align:start position:0% +they're sitting on on the very very + + + align:start position:0% +they're sitting on on the very very +complicated relations between uh the U.S + + align:start position:0% +complicated relations between uh the U.S + + + align:start position:0% +complicated relations between uh the U.S +and Britain let alone + + align:start position:0% +and Britain let alone + + + align:start position:0% +and Britain let alone +U.S and Soviets anything else so so I + + align:start position:0% +U.S and Soviets anything else so so I + + + align:start position:0% +U.S and Soviets anything else so so I +guess I take these these these these + + align:start position:0% +guess I take these these these these + + + align:start position:0% +guess I take these these these these +episodes as examples that some of these + + align:start position:0% +episodes as examples that some of these + + + align:start position:0% +episodes as examples that some of these +physicists were indeed trying to think + + align:start position:0% +physicists were indeed trying to think + + + align:start position:0% +physicists were indeed trying to think +one or two steps ahead and they were not + + align:start position:0% +one or two steps ahead and they were not + + + align:start position:0% +one or two steps ahead and they were not +maybe they misjudged you know their own + + align:start position:0% +maybe they misjudged you know their own + + + align:start position:0% +maybe they misjudged you know their own +kind of likely uh influence + + align:start position:0% +kind of likely uh influence + + + align:start position:0% +kind of likely uh influence +um so they get credit in my mind for + + align:start position:0% +um so they get credit in my mind for + + + align:start position:0% +um so they get credit in my mind for +thinking about it at all and trying but + + align:start position:0% +thinking about it at all and trying but + + + align:start position:0% +thinking about it at all and trying but +but the the + + align:start position:0% +but the the + + + align:start position:0% +but the the +it's not much of a track record you know + + align:start position:0% +it's not much of a track record you know + + + align:start position:0% +it's not much of a track record you know +in hindsight + + align:start position:0% + + + + align:start position:0% + +so great question you have a thank you + + align:start position:0% +so great question you have a thank you + + + align:start position:0% +so great question you have a thank you +really interesting so um the first + + align:start position:0% +really interesting so um the first + + + align:start position:0% +really interesting so um the first +impact was + + align:start position:0% +impact was + + + align:start position:0% +impact was +um it was it was not very many From Any + + align:start position:0% +um it was it was not very many From Any + + + align:start position:0% +um it was it was not very many From Any +Given campus so it wasn't like one + + align:start position:0% +Given campus so it wasn't like one + + + align:start position:0% +Given campus so it wasn't like one +Department was emptied out and in fact + + align:start position:0% +Department was emptied out and in fact + + + align:start position:0% +Department was emptied out and in fact +there was a at the time a very very + + align:start position:0% +there was a at the time a very very + + + align:start position:0% +there was a at the time a very very +strong concern on many many universities + + align:start position:0% +strong concern on many many universities + + + align:start position:0% +strong concern on many many universities +and college campus in the U.S to keep as + + align:start position:0% +and college campus in the U.S to keep as + + + align:start position:0% +and college campus in the U.S to keep as +many physicists on site as possible + + align:start position:0% +many physicists on site as possible + + + align:start position:0% +many physicists on site as possible +because they were involved in teaching + + align:start position:0% +because they were involved in teaching + + + align:start position:0% +because they were involved in teaching +what we would now consider basically + + align:start position:0% +what we would now consider basically + + + align:start position:0% +what we would now consider basically +classical physics + + align:start position:0% +classical physics + + + align:start position:0% +classical physics +um block sliding down planes and + + align:start position:0% +um block sliding down planes and + + + align:start position:0% +um block sliding down planes and +Elementary circuits and radio which was + + align:start position:0% +Elementary circuits and radio which was + + + align:start position:0% +Elementary circuits and radio which was +often done in physics departments not a + + align:start position:0% +often done in physics departments not a + + + align:start position:0% +often done in physics departments not a +separate electro engineering department + + align:start position:0% +separate electro engineering department + + + align:start position:0% +separate electro engineering department +many many places in time so there was a + + align:start position:0% +many many places in time so there was a + + + align:start position:0% +many many places in time so there was a +huge concern about literally they talked + + align:start position:0% +huge concern about literally they talked + + + align:start position:0% +huge concern about literally they talked +about rationing and stockpiling physics + + align:start position:0% +about rationing and stockpiling physics + + + align:start position:0% +about rationing and stockpiling physics +instructors to teach or sort of + + align:start position:0% +instructors to teach or sort of + + + align:start position:0% +instructors to teach or sort of +canonical college students but also to + + align:start position:0% +canonical college students but also to + + + align:start position:0% +canonical college students but also to +teach huge numbers of um Navy and army + + align:start position:0% +teach huge numbers of um Navy and army + + + align:start position:0% +teach huge numbers of um Navy and army +special students who were drafted + + align:start position:0% +special students who were drafted + + + align:start position:0% +special students who were drafted +sometimes often straight out of high + + align:start position:0% +sometimes often straight out of high + + + align:start position:0% +sometimes often straight out of high +school were not yet college students and + + align:start position:0% +school were not yet college students and + + + align:start position:0% +school were not yet college students and +were sent to many many campuses around + + align:start position:0% +were sent to many many campuses around + + + align:start position:0% +were sent to many many campuses around +the U.S + + align:start position:0% +the U.S + + + align:start position:0% +the U.S +um to for like crash course study very + + align:start position:0% +um to for like crash course study very + + + align:start position:0% +um to for like crash course study very +accelerated schedules to learn basically + + align:start position:0% +accelerated schedules to learn basically + + + align:start position:0% +accelerated schedules to learn basically +rudimentary physics like like for radio + + align:start position:0% +rudimentary physics like like for radio + + + align:start position:0% +rudimentary physics like like for radio +communication or you know or like citing + + align:start position:0% +communication or you know or like citing + + + align:start position:0% +communication or you know or like citing +or sound ranging it really was like + + align:start position:0% +or sound ranging it really was like + + + align:start position:0% +or sound ranging it really was like +classical physics and in fact physics + + align:start position:0% +classical physics and in fact physics + + + align:start position:0% +classical physics and in fact physics +departments were admonished not to waste + + align:start position:0% +departments were admonished not to waste + + + align:start position:0% +departments were admonished not to waste +their time teaching quantum mechanics or + + align:start position:0% +their time teaching quantum mechanics or + + + align:start position:0% +their time teaching quantum mechanics or +Nuclear Physics because that's not going + + align:start position:0% +Nuclear Physics because that's not going + + + align:start position:0% +Nuclear Physics because that's not going +to be of any importance during the war + + align:start position:0% +to be of any importance during the war + + + align:start position:0% +to be of any importance during the war +that kind of makes me smirk and they + + align:start position:0% +that kind of makes me smirk and they + + + align:start position:0% +that kind of makes me smirk and they +should put all their efforts teaching + + align:start position:0% +should put all their efforts teaching + + + align:start position:0% +should put all their efforts teaching +like classical e m uh and and Newtonian + + align:start position:0% +like classical e m uh and and Newtonian + + + align:start position:0% +like classical e m uh and and Newtonian +mechanics + + align:start position:0% +mechanics + + + align:start position:0% +mechanics +um whether it's for you know how do you + + align:start position:0% +um whether it's for you know how do you + + + align:start position:0% +um whether it's for you know how do you +measure air pressure what's a barometer + + align:start position:0% +measure air pressure what's a barometer + + + align:start position:0% +measure air pressure what's a barometer +what you know how do you measure angles + + align:start position:0% +what you know how do you measure angles + + + align:start position:0% +what you know how do you measure angles +with a with a handheld + + align:start position:0% +with a with a handheld + + + align:start position:0% +with a with a handheld +um you know kind of siding device so I + + align:start position:0% +um you know kind of siding device so I + + + align:start position:0% +um you know kind of siding device so I +find that really fascinating so the the + + align:start position:0% +find that really fascinating so the the + + + align:start position:0% +find that really fascinating so the the +term that's often used + + align:start position:0% +term that's often used + + + align:start position:0% +term that's often used +you might have heard the second world + + align:start position:0% +you might have heard the second world + + + align:start position:0% +you might have heard the second world +war has often been called the physicists + + align:start position:0% +war has often been called the physicists + + + align:start position:0% +war has often been called the physicists +war and that term has usually been taken + + align:start position:0% +war and that term has usually been taken + + + align:start position:0% +war and that term has usually been taken +to me oh we know what that means it was + + align:start position:0% +to me oh we know what that means it was + + + align:start position:0% +to me oh we know what that means it was +all about radar and the sort of exotic + + align:start position:0% +all about radar and the sort of exotic + + + align:start position:0% +all about radar and the sort of exotic +uh weapons projects like uh the + + align:start position:0% +uh weapons projects like uh the + + + align:start position:0% +uh weapons projects like uh the +Manhattan Project + + align:start position:0% +Manhattan Project + + + align:start position:0% +Manhattan Project +and so I actually wrote about this + + align:start position:0% +and so I actually wrote about this + + + align:start position:0% +and so I actually wrote about this +recently it turns out the phrase was + + align:start position:0% +recently it turns out the phrase was + + + align:start position:0% +recently it turns out the phrase was +introduced + + align:start position:0% +introduced + + + align:start position:0% +introduced +um before the attack on Pearl Harbor + + align:start position:0% +um before the attack on Pearl Harbor + + + align:start position:0% +um before the attack on Pearl Harbor +before there was Los Alamos laboratory + + align:start position:0% +before there was Los Alamos laboratory + + + align:start position:0% +before there was Los Alamos laboratory +at a time when radar was still deeply + + align:start position:0% +at a time when radar was still deeply + + + align:start position:0% +at a time when radar was still deeply +classified the usage of the term if you + + align:start position:0% +classified the usage of the term if you + + + align:start position:0% +classified the usage of the term if you +do one of these Google engrams all these + + align:start position:0% +do one of these Google engrams all these + + + align:start position:0% +do one of these Google engrams all these +fun things we could do now searching in + + align:start position:0% +fun things we could do now searching in + + + align:start position:0% +fun things we could do now searching in +English language Corpus the phrase + + align:start position:0% +English language Corpus the phrase + + + align:start position:0% +English language Corpus the phrase +physicist Wars use it as spiked in 1943 + + align:start position:0% +physicist Wars use it as spiked in 1943 + + + align:start position:0% +physicist Wars use it as spiked in 1943 +at which time anything about that and + + align:start position:0% +at which time anything about that and + + + align:start position:0% +at which time anything about that and +had project was deeply deeply classified + + align:start position:0% +had project was deeply deeply classified + + + align:start position:0% +had project was deeply deeply classified +they were not printing editorials about + + align:start position:0% +they were not printing editorials about + + + align:start position:0% +they were not printing editorials about +the nuclear weapons in the you know in + + align:start position:0% +the nuclear weapons in the you know in + + + align:start position:0% +the nuclear weapons in the you know in +the op-ed pages so the term business war + + align:start position:0% +the op-ed pages so the term business war + + + align:start position:0% +the op-ed pages so the term business war +was was used to respond to the fact that + + align:start position:0% +was was used to respond to the fact that + + + align:start position:0% +was was used to respond to the fact that +that uh that more and more young people + + align:start position:0% +that uh that more and more young people + + + align:start position:0% +that uh that more and more young people +mostly men mostly boys uh had to be + + align:start position:0% +mostly men mostly boys uh had to be + + + align:start position:0% +mostly men mostly boys uh had to be +trained in Crash Course settings on what + + align:start position:0% +trained in Crash Course settings on what + + + align:start position:0% +trained in Crash Course settings on what +we would call classical physics for + + align:start position:0% +we would call classical physics for + + + align:start position:0% +we would call classical physics for +practical purposes in the battlefield + + align:start position:0% +practical purposes in the battlefield + + + align:start position:0% +practical purposes in the battlefield +which by which they meant + + align:start position:0% +which by which they meant + + + align:start position:0% +which by which they meant +you know barometric pressure measure + + align:start position:0% +you know barometric pressure measure + + + align:start position:0% +you know barometric pressure measure +angles use siding on a gun and uh + + align:start position:0% +angles use siding on a gun and uh + + + align:start position:0% +angles use siding on a gun and uh +Elementary Electronics in circuits so + + align:start position:0% +Elementary Electronics in circuits so + + + align:start position:0% +Elementary Electronics in circuits so +the physicists were the meaning of the + + align:start position:0% +the physicists were the meaning of the + + + align:start position:0% +the physicists were the meaning of the +term actually changed quite dramatically + + align:start position:0% +term actually changed quite dramatically + + + align:start position:0% +term actually changed quite dramatically +after after this dramatic Revelation + + align:start position:0% +after after this dramatic Revelation + + + align:start position:0% +after after this dramatic Revelation +about these new previously secret + + align:start position:0% +about these new previously secret + + + align:start position:0% +about these new previously secret +weapons projects and the kind of impacts + + align:start position:0% +weapons projects and the kind of impacts + + + align:start position:0% +weapons projects and the kind of impacts +they had so there there were I mean so + + align:start position:0% +they had so there there were I mean so + + + align:start position:0% +they had so there there were I mean so +the so the physics classrooms were + + align:start position:0% +the so the physics classrooms were + + + align:start position:0% +the so the physics classrooms were +bulging faster than ever before they + + align:start position:0% +bulging faster than ever before they + + + align:start position:0% +bulging faster than ever before they +weren't getting drained out there were + + align:start position:0% +weren't getting drained out there were + + + align:start position:0% +weren't getting drained out there were +more people rushing to study Physics + + align:start position:0% +more people rushing to study Physics + + + align:start position:0% +more people rushing to study Physics +more more people who were put into + + align:start position:0% +more more people who were put into + + + align:start position:0% +more more people who were put into +physics classes whether they chose to or + + align:start position:0% +physics classes whether they chose to or + + + align:start position:0% +physics classes whether they chose to or +not and more and more people teaching + + align:start position:0% +not and more and more people teaching + + + align:start position:0% +not and more and more people teaching +physics in not just for Math and + + align:start position:0% +physics in not just for Math and + + + align:start position:0% +physics in not just for Math and +chemistry but from music anyone who had + + align:start position:0% +chemistry but from music anyone who had + + + align:start position:0% +chemistry but from music anyone who had +any kind of quantitative skills + + align:start position:0% +any kind of quantitative skills + + + align:start position:0% +any kind of quantitative skills +political science you know any + + align:start position:0% +political science you know any + + + align:start position:0% +political science you know any +statistics good now you know here's a + + align:start position:0% +statistics good now you know here's a + + + align:start position:0% +statistics good now you know here's a +crash course to relearn you know um + + align:start position:0% +crash course to relearn you know um + + + align:start position:0% +crash course to relearn you know um +calculus and you're going to teach Max + + align:start position:0% +calculus and you're going to teach Max + + + align:start position:0% +calculus and you're going to teach Max +equations next week and again anyone who + + align:start position:0% +equations next week and again anyone who + + + align:start position:0% +equations next week and again anyone who +is caught poaching that was there were + + align:start position:0% +is caught poaching that was there were + + + align:start position:0% +is caught poaching that was there were +stealing legitimate physics instructors + + align:start position:0% +stealing legitimate physics instructors + + + align:start position:0% +stealing legitimate physics instructors +from one campus uh were a subject to + + align:start position:0% +from one campus uh were a subject to + + + align:start position:0% +from one campus uh were a subject to +like public shaming so there was an + + align:start position:0% +like public shaming so there was an + + + align:start position:0% +like public shaming so there was an +effort to get to keep more and more + + align:start position:0% +effort to get to keep more and more + + + align:start position:0% +effort to get to keep more and more +physics instructors in the classrooms + + align:start position:0% +physics instructors in the classrooms + + + align:start position:0% +physics instructors in the classrooms +not to teach fancy fancy nuclear fission + + align:start position:0% +not to teach fancy fancy nuclear fission + + + align:start position:0% +not to teach fancy fancy nuclear fission +but rather these other topics + + align:start position:0% +but rather these other topics + + + align:start position:0% +but rather these other topics +um and that meant that when a couple + + align:start position:0% +um and that meant that when a couple + + + align:start position:0% +um and that meant that when a couple +slipped away it was I think lost kind of + + align:start position:0% +slipped away it was I think lost kind of + + + align:start position:0% +slipped away it was I think lost kind of +in the noise I have a feeling because + + align:start position:0% +in the noise I have a feeling because + + + align:start position:0% +in the noise I have a feeling because +there's so much tumult about these huge + + align:start position:0% +there's so much tumult about these huge + + + align:start position:0% +there's so much tumult about these huge +kind of throughput mit's Campus uh + + align:start position:0% +kind of throughput mit's Campus uh + + + align:start position:0% +kind of throughput mit's Campus uh +switched to basically 12-month + + align:start position:0% +switched to basically 12-month + + + align:start position:0% +switched to basically 12-month +instruction + + align:start position:0% +instruction + + + align:start position:0% +instruction +and we had I think at the height of this + + align:start position:0% +and we had I think at the height of this + + + align:start position:0% +and we had I think at the height of this +three times more or not three times it + + align:start position:0% +three times more or not three times it + + + align:start position:0% +three times more or not three times it +was like a three to two ratio so I guess + + align:start position:0% +was like a three to two ratio so I guess + + + align:start position:0% +was like a three to two ratio so I guess +one and a half times more so-called + + align:start position:0% +one and a half times more so-called + + + align:start position:0% +one and a half times more so-called +special students meaning full-time Army + + align:start position:0% +special students meaning full-time Army + + + align:start position:0% +special students meaning full-time Army +and Navy students assigned to MIT for + + align:start position:0% +and Navy students assigned to MIT for + + + align:start position:0% +and Navy students assigned to MIT for +like six week terms than MIT students so + + align:start position:0% +like six week terms than MIT students so + + + align:start position:0% +like six week terms than MIT students so +mit's own campus was was kind of taken + + align:start position:0% +mit's own campus was was kind of taken + + + align:start position:0% +mit's own campus was was kind of taken +over was put into high gear that was + + align:start position:0% +over was put into high gear that was + + + align:start position:0% +over was put into high gear that was +that was very common in many many other + + align:start position:0% +that was very common in many many other + + + align:start position:0% +that was very common in many many other +um liberal arts tiny liberal arts + + align:start position:0% +um liberal arts tiny liberal arts + + + align:start position:0% +um liberal arts tiny liberal arts +colleges big universities I think in + + align:start position:0% +colleges big universities I think in + + + align:start position:0% +colleges big universities I think in +between + + align:start position:0% +between + + + align:start position:0% +between +um these very very intensive kind of + + align:start position:0% +um these very very intensive kind of + + + align:start position:0% +um these very very intensive kind of +short-term uh crash course uh things in + + align:start position:0% +short-term uh crash course uh things in + + + align:start position:0% +short-term uh crash course uh things in +fact is I if I can find it in time I'll + + align:start position:0% +fact is I if I can find it in time I'll + + + align:start position:0% +fact is I if I can find it in time I'll +put it in the in the chat one of my + + align:start position:0% +put it in the in the chat one of my + + + align:start position:0% +put it in the in the chat one of my +favorite photos is actually of 10 to 50 + + align:start position:0% +favorite photos is actually of 10 to 50 + + + align:start position:0% +favorite photos is actually of 10 to 50 +or I don't know if it's your beloved or + + align:start position:0% +or I don't know if it's your beloved or + + + align:start position:0% +or I don't know if it's your beloved or +you're hated you're a room many of you + + align:start position:0% +you're hated you're a room many of you + + + align:start position:0% +you're hated you're a room many of you +will probably know one of our big big + + align:start position:0% +will probably know one of our big big + + + align:start position:0% +will probably know one of our big big +lecture Halls 10 to 50. filled with + + align:start position:0% +lecture Halls 10 to 50. filled with + + + align:start position:0% +lecture Halls 10 to 50. filled with +young men in uniform taking one of these + + align:start position:0% +young men in uniform taking one of these + + + align:start position:0% +young men in uniform taking one of these +crash course classes in probably like + + align:start position:0% +crash course classes in probably like + + + align:start position:0% +crash course classes in probably like +Elementary circuits + + align:start position:0% +Elementary circuits + + + align:start position:0% +Elementary circuits +and it just just a Sea of Faces that all + + align:start position:0% +and it just just a Sea of Faces that all + + + align:start position:0% +and it just just a Sea of Faces that all +look the same in all the same uniforms + + align:start position:0% +look the same in all the same uniforms + + + align:start position:0% +look the same in all the same uniforms +just you know 400 people filling 10 to + + align:start position:0% +just you know 400 people filling 10 to + + + align:start position:0% +just you know 400 people filling 10 to +50 all in in their khakis that's that's + + align:start position:0% +50 all in in their khakis that's that's + + + align:start position:0% +50 all in in their khakis that's that's +what campus at MIT was was was like that + + align:start position:0% +what campus at MIT was was was like that + + + align:start position:0% +what campus at MIT was was was like that +was a predominant thing as opposed to uh + + align:start position:0% +was a predominant thing as opposed to uh + + + align:start position:0% +was a predominant thing as opposed to uh +hey where'd all these people go they + + align:start position:0% +hey where'd all these people go they + + + align:start position:0% +hey where'd all these people go they +must be doing something top secret + + align:start position:0% +must be doing something top secret + + + align:start position:0% +must be doing something top secret +uh Gary Europe and then Alex + + align:start position:0% +uh Gary Europe and then Alex + + + align:start position:0% +uh Gary Europe and then Alex +um I just wanted to share a a movie + + align:start position:0% +um I just wanted to share a a movie + + + align:start position:0% +um I just wanted to share a a movie +suggestion because you mentioned Dresden + + align:start position:0% +suggestion because you mentioned Dresden + + + align:start position:0% +suggestion because you mentioned Dresden +and it's a chilling movie but it's about + + align:start position:0% +and it's a chilling movie but it's about + + + align:start position:0% +and it's a chilling movie but it's about +how things can get normalized Bob + + align:start position:0% +how things can get normalized Bob + + + align:start position:0% +how things can get normalized Bob +McNamara who is the Secretary of Defense + + align:start position:0% +McNamara who is the Secretary of Defense + + + align:start position:0% +McNamara who is the Secretary of Defense +during the Vietnam war but was very + + align:start position:0% +during the Vietnam war but was very + + + align:start position:0% +during the Vietnam war but was very +involved in World War II uh with regard + + align:start position:0% +involved in World War II uh with regard + + + align:start position:0% +involved in World War II uh with regard +to the bombings in Tokyo the Tokyo fire + + align:start position:0% +to the bombings in Tokyo the Tokyo fire + + + align:start position:0% +to the bombings in Tokyo the Tokyo fire +bombing I got to know Bob very late in + + align:start position:0% +bombing I got to know Bob very late in + + + align:start position:0% +bombing I got to know Bob very late in +his life and I thought I'm going to hate + + align:start position:0% +his life and I thought I'm going to hate + + + align:start position:0% +his life and I thought I'm going to hate +this guy I I grew up just hating the + + align:start position:0% +this guy I I grew up just hating the + + + align:start position:0% +this guy I I grew up just hating the +whole idea of who the Secretary of + + align:start position:0% +whole idea of who the Secretary of + + + align:start position:0% +whole idea of who the Secretary of +Defense in the Vietnam War might be and + + align:start position:0% +Defense in the Vietnam War might be and + + + align:start position:0% +Defense in the Vietnam War might be and +he he was reflective about it and he + + align:start position:0% +he he was reflective about it and he + + + align:start position:0% +he he was reflective about it and he +made this movie when I knew him but he + + align:start position:0% +made this movie when I knew him but he + + + align:start position:0% +made this movie when I knew him but he +it's really worthwhile to watch the fog + + align:start position:0% +it's really worthwhile to watch the fog + + + align:start position:0% +it's really worthwhile to watch the fog +of War before yes one other story about + + align:start position:0% +of War before yes one other story about + + + align:start position:0% +of War before yes one other story about +normalizing my father was a Corporal + + align:start position:0% +normalizing my father was a Corporal + + + align:start position:0% +normalizing my father was a Corporal +never went to college and he was in + + align:start position:0% +never went to college and he was in + + + align:start position:0% +never went to college and he was in +tidion yeah and so the day after + + align:start position:0% +tidion yeah and so the day after + + + align:start position:0% +tidion yeah and so the day after +Nagasaki the general said to him Sammy + + align:start position:0% +Nagasaki the general said to him Sammy + + + align:start position:0% +Nagasaki the general said to him Sammy +you want to go up and see what we did + + align:start position:0% +you want to go up and see what we did + + + align:start position:0% +you want to go up and see what we did +yesterday so my dad flew over Nagasaki + + align:start position:0% +yesterday so my dad flew over Nagasaki + + + align:start position:0% +yesterday so my dad flew over Nagasaki +literally the day after + + align:start position:0% +literally the day after + + + align:start position:0% +literally the day after +30 or 40 years later if I had asked my + + align:start position:0% +30 or 40 years later if I had asked my + + + align:start position:0% +30 or 40 years later if I had asked my +dad about it and he was a good man I + + align:start position:0% +dad about it and he was a good man I + + + align:start position:0% +dad about it and he was a good man I +love I love him to this day + + align:start position:0% +love I love him to this day + + + align:start position:0% +love I love him to this day +um but he would say I'd say what do you + + align:start position:0% +um but he would say I'd say what do you + + + align:start position:0% +um but he would say I'd say what do you +think he said Gary we did what we needed + + align:start position:0% +think he said Gary we did what we needed + + + align:start position:0% +think he said Gary we did what we needed +to do + + align:start position:0% +to do + + + align:start position:0% +to do +it was just a Corp role he was a radio + + align:start position:0% +it was just a Corp role he was a radio + + + align:start position:0% +it was just a Corp role he was a radio +mechanic yeah + + align:start position:0% +mechanic yeah + + + align:start position:0% +mechanic yeah +um but it just it got normalized I have + + align:start position:0% +um but it just it got normalized I have + + + align:start position:0% +um but it just it got normalized I have +a question for you David do you know why + + align:start position:0% +a question for you David do you know why + + + align:start position:0% +a question for you David do you know why +um + + align:start position:0% +um + + + align:start position:0% +um +Jacob Beezer was the only man on both I + + align:start position:0% +Jacob Beezer was the only man on both I + + + align:start position:0% +Jacob Beezer was the only man on both I +don't know the answer but I knew his son + + align:start position:0% +don't know the answer but I knew his son + + + align:start position:0% +don't know the answer but I knew his son +I knew Jerry Beezer his son but Jacob + + align:start position:0% +I knew Jerry Beezer his son but Jacob + + + align:start position:0% +I knew Jerry Beezer his son but Jacob +beaser was the radar man on both flights + + align:start position:0% +beaser was the radar man on both flights + + + align:start position:0% +beaser was the radar man on both flights +and why did they do that he's the only + + align:start position:0% +and why did they do that he's the only + + + align:start position:0% +and why did they do that he's the only +person that was on both flights that's + + align:start position:0% +person that was on both flights that's + + + align:start position:0% +person that was on both flights that's +fascinating I didn't I didn't know that + + align:start position:0% +fascinating I didn't I didn't know that + + + align:start position:0% +fascinating I didn't I didn't know that +Gary so my guess I'm just guessing I'm + + align:start position:0% +Gary so my guess I'm just guessing I'm + + + align:start position:0% +Gary so my guess I'm just guessing I'm +spectating and Wikipedia might answer it + + align:start position:0% +spectating and Wikipedia might answer it + + + align:start position:0% +spectating and Wikipedia might answer it +you know quicker and maybe even more + + align:start position:0% +you know quicker and maybe even more + + + align:start position:0% +you know quicker and maybe even more +accurate than me my guess is that it was + + align:start position:0% +accurate than me my guess is that it was + + + align:start position:0% +accurate than me my guess is that it was +still you know it was kind of a + + align:start position:0% +still you know it was kind of a + + + align:start position:0% +still you know it was kind of a +shoestring operation that tinian I mean + + align:start position:0% +shoestring operation that tinian I mean + + + align:start position:0% +shoestring operation that tinian I mean +they were throwing this thing together + + align:start position:0% +they were throwing this thing together + + + align:start position:0% +they were throwing this thing together +they just barely gotten the kind of + + align:start position:0% +they just barely gotten the kind of + + + align:start position:0% +they just barely gotten the kind of +airstrip to dry you know that it was so + + align:start position:0% +airstrip to dry you know that it was so + + + align:start position:0% +airstrip to dry you know that it was so +last minute + + align:start position:0% +last minute + + + align:start position:0% +last minute +that my guess is it was just it could it + + align:start position:0% +that my guess is it was just it could it + + + align:start position:0% +that my guess is it was just it could it +could as well have been short staffed as + + align:start position:0% +could as well have been short staffed as + + + align:start position:0% +could as well have been short staffed as +any kind of strategic reason especially + + align:start position:0% +any kind of strategic reason especially + + + align:start position:0% +any kind of strategic reason especially +if it was it was a more kind of + + align:start position:0% +if it was it was a more kind of + + + align:start position:0% +if it was it was a more kind of +specialized role like the radar operator + + align:start position:0% +specialized role like the radar operator + + + align:start position:0% +specialized role like the radar operator +uh it wouldn't surprise me if he was the + + align:start position:0% +uh it wouldn't surprise me if he was the + + + align:start position:0% +uh it wouldn't surprise me if he was the +person who had been trained and was + + align:start position:0% +person who had been trained and was + + + align:start position:0% +person who had been trained and was +available I don't know if it was any + + align:start position:0% +available I don't know if it was any + + + align:start position:0% +available I don't know if it was any +more than that so it was Galaxy + + align:start position:0% +more than that so it was Galaxy + + + align:start position:0% +more than that so it was Galaxy +something else you had said oh yeah yeah + + align:start position:0% +something else you had said oh yeah yeah + + + align:start position:0% +something else you had said oh yeah yeah +so let me just say briefly because + + align:start position:0% +so let me just say briefly because + + + align:start position:0% +so let me just say briefly because +something the film didn't really uh get + + align:start position:0% +something the film didn't really uh get + + + align:start position:0% +something the film didn't really uh get +into a lot of the scholarship in the 40 + + align:start position:0% +into a lot of the scholarship in the 40 + + + align:start position:0% +into a lot of the scholarship in the 40 +years since even the film came out let + + align:start position:0% +years since even the film came out let + + + align:start position:0% +years since even the film came out let +alone the 75 years since the events in + + align:start position:0% +alone the 75 years since the events in + + + align:start position:0% +alone the 75 years since the events in +question + + align:start position:0% +question + + + align:start position:0% +question +has really gone around and around + + align:start position:0% +has really gone around and around + + + align:start position:0% +has really gone around and around +frankly or or has been a very vigorous + + align:start position:0% +frankly or or has been a very vigorous + + + align:start position:0% +frankly or or has been a very vigorous +debate but put it that way about + + align:start position:0% +debate but put it that way about + + + align:start position:0% +debate but put it that way about +um + + align:start position:0% +um + + + align:start position:0% +um +basically uh were the bombs needed + + align:start position:0% +basically uh were the bombs needed + + + align:start position:0% +basically uh were the bombs needed +that's kind of a second guessing after + + align:start position:0% +that's kind of a second guessing after + + + align:start position:0% +that's kind of a second guessing after +the fact or put a little more proact Pro + + align:start position:0% +the fact or put a little more proact Pro + + + align:start position:0% +the fact or put a little more proact Pro +perspectively what convinced people to + + align:start position:0% +perspectively what convinced people to + + + align:start position:0% +perspectively what convinced people to +give this standing order to use to use + + align:start position:0% +give this standing order to use to use + + + align:start position:0% +give this standing order to use to use +these weapons you know at all + + align:start position:0% +these weapons you know at all + + + align:start position:0% +these weapons you know at all +and the soon after the war I think it + + align:start position:0% +and the soon after the war I think it + + + align:start position:0% +and the soon after the war I think it +was 1947. the the then the person who + + align:start position:0% +was 1947. the the then the person who + + + align:start position:0% +was 1947. the the then the person who +had been Secretary of War during the + + align:start position:0% +had been Secretary of War during the + + + align:start position:0% +had been Secretary of War during the +second World War uh Henry Simpson + + align:start position:0% +second World War uh Henry Simpson + + + align:start position:0% +second World War uh Henry Simpson +published a famous famous article + + align:start position:0% +published a famous famous article + + + align:start position:0% +published a famous famous article +basically justifying the use of the + + align:start position:0% +basically justifying the use of the + + + align:start position:0% +basically justifying the use of the +nuclear weapons and he's saying it saved + + align:start position:0% +nuclear weapons and he's saying it saved + + + align:start position:0% +nuclear weapons and he's saying it saved +A Million Lives I and then became was it + + align:start position:0% +A Million Lives I and then became was it + + + align:start position:0% +A Million Lives I and then became was it +either a million fatalities or + + align:start position:0% +either a million fatalities or + + + align:start position:0% +either a million fatalities or +casualties by the way he said if the + + align:start position:0% +casualties by the way he said if the + + + align:start position:0% +casualties by the way he said if the +United States had to actually launch + + align:start position:0% +United States had to actually launch + + + align:start position:0% +United States had to actually launch +this planned in-person invasion of the + + align:start position:0% +this planned in-person invasion of the + + + align:start position:0% +this planned in-person invasion of the +Mainland of Japan if there were if there + + align:start position:0% +Mainland of Japan if there were if there + + + align:start position:0% +Mainland of Japan if there were if there +was no way to get to to secure a + + align:start position:0% +was no way to get to to secure a + + + align:start position:0% +was no way to get to to secure a +surrender in an end of the war other + + align:start position:0% +surrender in an end of the war other + + + align:start position:0% +surrender in an end of the war other +than a fully armed invasion of the + + align:start position:0% +than a fully armed invasion of the + + + align:start position:0% +than a fully armed invasion of the +Mainland which is what was indeed being + + align:start position:0% +Mainland which is what was indeed being + + + align:start position:0% +Mainland which is what was indeed being +planned + + align:start position:0% +planned + + + align:start position:0% +planned +by U.S mostly us Allied Forces + + align:start position:0% +by U.S mostly us Allied Forces + + + align:start position:0% +by U.S mostly us Allied Forces +then the casualty count both among U.S + + align:start position:0% +then the casualty count both among U.S + + + align:start position:0% +then the casualty count both among U.S +soldiers and among Japanese civilians + + align:start position:0% +soldiers and among Japanese civilians + + + align:start position:0% +soldiers and among Japanese civilians +would have been astronomical and they + + align:start position:0% +would have been astronomical and they + + + align:start position:0% +would have been astronomical and they +and he mentions that figure one million + + align:start position:0% +and he mentions that figure one million + + + align:start position:0% +and he mentions that figure one million +well other where to get the figure one + + align:start position:0% +well other where to get the figure one + + + align:start position:0% +well other where to get the figure one +million from it seems to have been + + align:start position:0% +million from it seems to have been + + + align:start position:0% +million from it seems to have been +invented in 1947. it seems not to have + + align:start position:0% +invented in 1947. it seems not to have + + + align:start position:0% +invented in 1947. it seems not to have +come from any classified or since + + align:start position:0% +come from any classified or since + + + align:start position:0% +come from any classified or since +Declassified military planning document + + align:start position:0% +Declassified military planning document + + + align:start position:0% +Declassified military planning document +ahead of time so so then the question + + align:start position:0% +ahead of time so so then the question + + + align:start position:0% +ahead of time so so then the question +has becomes would Innovation have been + + align:start position:0% +has becomes would Innovation have been + + + align:start position:0% +has becomes would Innovation have been +necessary were there other reasons to + + align:start position:0% +necessary were there other reasons to + + + align:start position:0% +necessary were there other reasons to +have thought of the space information + + align:start position:0% +have thought of the space information + + + align:start position:0% +have thought of the space information +available at the time that Japan might + + align:start position:0% +available at the time that Japan might + + + align:start position:0% +available at the time that Japan might +or might not have been getting closer to + + align:start position:0% +or might not have been getting closer to + + + align:start position:0% +or might not have been getting closer to +a surrender even prior to the use of the + + align:start position:0% +a surrender even prior to the use of the + + + align:start position:0% +a surrender even prior to the use of the +problems alone would an invasion have + + align:start position:0% +problems alone would an invasion have + + + align:start position:0% +problems alone would an invasion have +been needed and if an invasion were + + align:start position:0% +been needed and if an invasion were + + + align:start position:0% +been needed and if an invasion were +needed where do these casualty figures + + align:start position:0% +needed where do these casualty figures + + + align:start position:0% +needed where do these casualty figures +these projected figures have come from + + align:start position:0% +these projected figures have come from + + + align:start position:0% +these projected figures have come from +so I'll just say I don't have I don't + + align:start position:0% +so I'll just say I don't have I don't + + + align:start position:0% +so I'll just say I don't have I don't +know all the answers but I know people + + align:start position:0% +know all the answers but I know people + + + align:start position:0% +know all the answers but I know people +have poured over this very very + + align:start position:0% +have poured over this very very + + + align:start position:0% +have poured over this very very +carefully and say each of those + + align:start position:0% +carefully and say each of those + + + align:start position:0% +carefully and say each of those +questions is subject to let's say many + + align:start position:0% +questions is subject to let's say many + + + align:start position:0% +questions is subject to let's say many +compelling and quite different answers + + align:start position:0% +compelling and quite different answers + + + align:start position:0% +compelling and quite different answers +um + + align:start position:0% +um + + + align:start position:0% +um +so + + align:start position:0% +so + + + align:start position:0% +so +so many many U.S uh military officials + + align:start position:0% +so many many U.S uh military officials + + + align:start position:0% +so many many U.S uh military officials +as later came out in in Declassified + + align:start position:0% +as later came out in in Declassified + + + align:start position:0% +as later came out in in Declassified +doctors that were at the time quite + + align:start position:0% +doctors that were at the time quite + + + align:start position:0% +doctors that were at the time quite +Secret + + align:start position:0% +Secret + + + align:start position:0% +Secret +we're we're already raising skepticism + + align:start position:0% +we're we're already raising skepticism + + + align:start position:0% +we're we're already raising skepticism +about whether a a full you of invasion + + align:start position:0% +about whether a a full you of invasion + + + align:start position:0% +about whether a a full you of invasion +would be needed at all and then other + + align:start position:0% +would be needed at all and then other + + + align:start position:0% +would be needed at all and then other +people say oh but that was before the + + align:start position:0% +people say oh but that was before the + + + align:start position:0% +people say oh but that was before the +really uh quite horrible fighting in + + align:start position:0% +really uh quite horrible fighting in + + + align:start position:0% +really uh quite horrible fighting in +Okinawa which was in June so maybe there + + align:start position:0% +Okinawa which was in June so maybe there + + + align:start position:0% +Okinawa which was in June so maybe there +was a kind of fear a concern that the + + align:start position:0% +was a kind of fear a concern that the + + + align:start position:0% +was a kind of fear a concern that the +Japanese troops would actually not + + align:start position:0% +Japanese troops would actually not + + + align:start position:0% +Japanese troops would actually not +surrender even if they were clearly uh + + align:start position:0% +surrender even if they were clearly uh + + + align:start position:0% +surrender even if they were clearly uh +you know overwhelmed numerically so like + + align:start position:0% +you know overwhelmed numerically so like + + + align:start position:0% +you know overwhelmed numerically so like +did which military officials even + + align:start position:0% +did which military officials even + + + align:start position:0% +did which military officials even +thought we'd need that we the United + + align:start position:0% +thought we'd need that we the United + + + align:start position:0% +thought we'd need that we the United +States would need to mount an invasion + + align:start position:0% +States would need to mount an invasion + + + align:start position:0% +States would need to mount an invasion +that's already actually pretty + + align:start position:0% +that's already actually pretty + + + align:start position:0% +that's already actually pretty +complicated based on the documents that + + align:start position:0% +complicated based on the documents that + + + align:start position:0% +complicated based on the documents that +have since much later become available + + align:start position:0% +have since much later become available + + + align:start position:0% +have since much later become available +some people clearly wrote down Japan is + + align:start position:0% +some people clearly wrote down Japan is + + + align:start position:0% +some people clearly wrote down Japan is +on the brink of surrender anyway not you + + align:start position:0% +on the brink of surrender anyway not you + + + align:start position:0% +on the brink of surrender anyway not you +know prior to the use of the weapons + + align:start position:0% +know prior to the use of the weapons + + + align:start position:0% +know prior to the use of the weapons +prior to any Invasion other people said + + align:start position:0% +prior to any Invasion other people said + + + align:start position:0% +prior to any Invasion other people said +oh we thought they might surrender but + + align:start position:0% +oh we thought they might surrender but + + + align:start position:0% +oh we thought they might surrender but +now we're not so sure because of the + + align:start position:0% +now we're not so sure because of the + + + align:start position:0% +now we're not so sure because of the +really quite just horrific fighting the + + align:start position:0% +really quite just horrific fighting the + + + align:start position:0% +really quite just horrific fighting the +kind of dug in fighting especially at + + align:start position:0% +kind of dug in fighting especially at + + + align:start position:0% +kind of dug in fighting especially at +Okinawa late late not too long before + + align:start position:0% +Okinawa late late not too long before + + + align:start position:0% +Okinawa late late not too long before +the use of the nuclear weapons + + align:start position:0% +the use of the nuclear weapons + + + align:start position:0% +the use of the nuclear weapons +then there are all these questions like + + align:start position:0% +then there are all these questions like + + + align:start position:0% +then there are all these questions like +were the were there weapons used to end + + align:start position:0% +were the were there weapons used to end + + + align:start position:0% +were the were there weapons used to end +the war or to secure the post-war so was + + align:start position:0% +the war or to secure the post-war so was + + + align:start position:0% +the war or to secure the post-war so was +it signaling vis-a-vis rivalries with + + align:start position:0% +it signaling vis-a-vis rivalries with + + + align:start position:0% +it signaling vis-a-vis rivalries with +the Soviet Union which is a popular + + align:start position:0% +the Soviet Union which is a popular + + + align:start position:0% +the Soviet Union which is a popular +thesis or other things was it were they + + align:start position:0% +thesis or other things was it were they + + + align:start position:0% +thesis or other things was it were they +used for a kind of geopolitical strategy + + align:start position:0% +used for a kind of geopolitical strategy + + + align:start position:0% +used for a kind of geopolitical strategy +at least as much if not more than for + + align:start position:0% +at least as much if not more than for + + + align:start position:0% +at least as much if not more than for +direct kind of military strategy and + + align:start position:0% +direct kind of military strategy and + + + align:start position:0% +direct kind of military strategy and +again + + align:start position:0% +again + + + align:start position:0% +again +there are very compelling arguments + + align:start position:0% +there are very compelling arguments + + + align:start position:0% +there are very compelling arguments +based on lots and lots of documents on + + align:start position:0% +based on lots and lots of documents on + + + align:start position:0% +based on lots and lots of documents on +kind of not just both sides but a whole + + align:start position:0% +kind of not just both sides but a whole + + + align:start position:0% +kind of not just both sides but a whole +kind of spectrum of that it gets pretty + + align:start position:0% +kind of spectrum of that it gets pretty + + + align:start position:0% +kind of spectrum of that it gets pretty +murky pretty quickly + + align:start position:0% +murky pretty quickly + + + align:start position:0% +murky pretty quickly +so uh so there are waves of kind of re + + align:start position:0% +so uh so there are waves of kind of re + + + align:start position:0% +so uh so there are waves of kind of re +revisiting these questions about of what + + align:start position:0% +revisiting these questions about of what + + + align:start position:0% +revisiting these questions about of what +what military role do the weapons play + + align:start position:0% +what military role do the weapons play + + + align:start position:0% +what military role do the weapons play +and I'm not saying one or the other I + + align:start position:0% +and I'm not saying one or the other I + + + align:start position:0% +and I'm not saying one or the other I +actually I think it's complicated right + + align:start position:0% +actually I think it's complicated right + + + align:start position:0% +actually I think it's complicated right +but you can get these really interesting + + align:start position:0% +but you can get these really interesting + + + align:start position:0% +but you can get these really interesting +studies based on a lot more than what + + align:start position:0% +studies based on a lot more than what + + + align:start position:0% +studies based on a lot more than what +was publicly accessible uh in 1955 or + + align:start position:0% +was publicly accessible uh in 1955 or + + + align:start position:0% +was publicly accessible uh in 1955 or +even 1965 with the with much more + + align:start position:0% +even 1965 with the with much more + + + align:start position:0% +even 1965 with the with much more +passage of time and much more active use + + align:start position:0% +passage of time and much more active use + + + align:start position:0% +passage of time and much more active use +of Freedom of Information Act and + + align:start position:0% +of Freedom of Information Act and + + + align:start position:0% +of Freedom of Information Act and +declassification so on you know it's it + + align:start position:0% +declassification so on you know it's it + + + align:start position:0% +declassification so on you know it's it +it's pretty complicated + + align:start position:0% +it's pretty complicated + + + align:start position:0% +it's pretty complicated +um and so again that we go back to an + + align:start position:0% +um and so again that we go back to an + + + align:start position:0% +um and so again that we go back to an +early question where the bombs to the + + align:start position:0% +early question where the bombs to the + + + align:start position:0% +early question where the bombs to the +bombs and the war where they somehow + + align:start position:0% +bombs and the war where they somehow + + + align:start position:0% +bombs and the war where they somehow +special that incendiary bombings at + + align:start position:0% +special that incendiary bombings at + + + align:start position:0% +special that incendiary bombings at +leveled cities were not capable of + + align:start position:0% +leveled cities were not capable of + + + align:start position:0% +leveled cities were not capable of +ending the war but these special weapons + + align:start position:0% +ending the war but these special weapons + + + align:start position:0% +ending the war but these special weapons +were that was a popular interpretation + + align:start position:0% +were that was a popular interpretation + + + align:start position:0% +were that was a popular interpretation +very soon after the war when these + + align:start position:0% +very soon after the war when these + + + align:start position:0% +very soon after the war when these +things were revealed in such a dramatic + + align:start position:0% +things were revealed in such a dramatic + + + align:start position:0% +things were revealed in such a dramatic +way and then Generations since have gone + + align:start position:0% +way and then Generations since have gone + + + align:start position:0% +way and then Generations since have gone +back to the question and I think it's + + align:start position:0% +back to the question and I think it's + + + align:start position:0% +back to the question and I think it's +it's a little it's more complicated more + + align:start position:0% +it's a little it's more complicated more + + + align:start position:0% +it's a little it's more complicated more +subtle than some of the early pronounces + + align:start position:0% +subtle than some of the early pronounces + + + align:start position:0% +subtle than some of the early pronounces +either Pro or con + + align:start position:0% +either Pro or con + + + align:start position:0% +either Pro or con +uh and the people mentioned I could I'd + + align:start position:0% +uh and the people mentioned I could I'd + + + align:start position:0% +uh and the people mentioned I could I'd +be glad to share kind of reading lists + + align:start position:0% +be glad to share kind of reading lists + + + align:start position:0% +be glad to share kind of reading lists +of lots of things that dug into that + + align:start position:0% +of lots of things that dug into that + + + align:start position:0% +of lots of things that dug into that +since then + + align:start position:0% + + + + align:start position:0% + +I think the answer is neither and here's + + align:start position:0% +I think the answer is neither and here's + + + align:start position:0% +I think the answer is neither and here's +my understanding Alex but again I'm this + + align:start position:0% +my understanding Alex but again I'm this + + + align:start position:0% +my understanding Alex but again I'm this +is my uh I think it was raised as a + + align:start position:0% +is my uh I think it was raised as a + + + align:start position:0% +is my uh I think it was raised as a +serious question long before the test + + align:start position:0% +serious question long before the test + + + align:start position:0% +serious question long before the test +and settled to everyone's satisfaction + + align:start position:0% +and settled to everyone's satisfaction + + + align:start position:0% +and settled to everyone's satisfaction +before the test so I don't think it was + + align:start position:0% +before the test so I don't think it was + + + align:start position:0% +before the test so I don't think it was +only ever I think it was only a joke + + align:start position:0% +only ever I think it was only a joke + + + align:start position:0% +only ever I think it was only a joke +I think by the time of the test date + + align:start position:0% +I think by the time of the test date + + + align:start position:0% +I think by the time of the test date +people weren't worried about that the + + align:start position:0% +people weren't worried about that the + + + align:start position:0% +people weren't worried about that the +way they once had legitimately sat down + + align:start position:0% +way they once had legitimately sat down + + + align:start position:0% +way they once had legitimately sat down +and calculated they didn't just say gosh + + align:start position:0% +and calculated they didn't just say gosh + + + align:start position:0% +and calculated they didn't just say gosh +I wonder let's try it so I don't think + + align:start position:0% +I wonder let's try it so I don't think + + + align:start position:0% +I wonder let's try it so I don't think +it was a joke but I also think it was no + + align:start position:0% +it was a joke but I also think it was no + + + align:start position:0% +it was a joke but I also think it was no +longer a kind of live debated scientific + + align:start position:0% +longer a kind of live debated scientific + + + align:start position:0% +longer a kind of live debated scientific +question by by mid-july of 45. + + align:start position:0% +question by by mid-july of 45. + + + align:start position:0% +question by by mid-july of 45. +um I think they're you know my + + align:start position:0% +um I think they're you know my + + + align:start position:0% +um I think they're you know my +understanding is Enrico Fermi did was + + align:start position:0% +understanding is Enrico Fermi did was + + + align:start position:0% +understanding is Enrico Fermi did was +the one who articulated that question + + align:start position:0% +the one who articulated that question + + + align:start position:0% +the one who articulated that question +but not like the morning of I think + + align:start position:0% +but not like the morning of I think + + + align:start position:0% +but not like the morning of I think +there was enough time for enough people + + align:start position:0% +there was enough time for enough people + + + align:start position:0% +there was enough time for enough people +to to sit at that and check each other's + + align:start position:0% +to to sit at that and check each other's + + + align:start position:0% +to to sit at that and check each other's +calculations and really and not only + + align:start position:0% +calculations and really and not only + + + align:start position:0% +calculations and really and not only +physicists actually people know stuff + + align:start position:0% +physicists actually people know stuff + + + align:start position:0% +physicists actually people know stuff +like chemists and other people who had + + align:start position:0% +like chemists and other people who had + + + align:start position:0% +like chemists and other people who had +relevant expertise + + align:start position:0% +relevant expertise + + + align:start position:0% +relevant expertise +um I think there was there was a vetting + + align:start position:0% +um I think there was there was a vetting + + + align:start position:0% +um I think there was there was a vetting +of that question well before the test + + align:start position:0% +of that question well before the test + + + align:start position:0% +of that question well before the test +date + + align:start position:0% + + + + align:start position:0% + +yes so the short answer is yes but again + + align:start position:0% +yes so the short answer is yes but again + + + align:start position:0% +yes so the short answer is yes but again +I don't but but + + align:start position:0% +I don't but but + + + align:start position:0% +I don't but but +but you you phrased it very very well + + align:start position:0% +but you you phrased it very very well + + + align:start position:0% +but you you phrased it very very well +actually was there any indication the + + align:start position:0% +actually was there any indication the + + + align:start position:0% +actually was there any indication the +answer is yes not definitive indication + + align:start position:0% +answer is yes not definitive indication + + + align:start position:0% +answer is yes not definitive indication +that's why it's still you know you know + + align:start position:0% +that's why it's still you know you know + + + align:start position:0% +that's why it's still you know you know +the phrase war is hell like it's it's + + align:start position:0% +the phrase war is hell like it's it's + + + align:start position:0% +the phrase war is hell like it's it's +it's held for information as well as for + + align:start position:0% +it's held for information as well as for + + + align:start position:0% +it's held for information as well as for +all the more more obvious um reasons so + + align:start position:0% +all the more more obvious um reasons so + + + align:start position:0% +all the more more obvious um reasons so +here's what here's what I mean by that + + align:start position:0% +here's what here's what I mean by that + + + align:start position:0% +here's what here's what I mean by that +it has come to light since then that + + align:start position:0% +it has come to light since then that + + + align:start position:0% +it has come to light since then that +first of all uh some countries had + + align:start position:0% +first of all uh some countries had + + + align:start position:0% +first of all uh some countries had +cracked the Japanese encrypted cables so + + align:start position:0% +cracked the Japanese encrypted cables so + + + align:start position:0% +cracked the Japanese encrypted cables so +and and was leaking that information to + + align:start position:0% +and and was leaking that information to + + + align:start position:0% +and and was leaking that information to +Washington and London and and probably + + align:start position:0% +Washington and London and and probably + + + align:start position:0% +Washington and London and and probably +Moscow as well so some elements of the + + align:start position:0% +Moscow as well so some elements of the + + + align:start position:0% +Moscow as well so some elements of the +Japanese government which at this point + + align:start position:0% +Japanese government which at this point + + + align:start position:0% +Japanese government which at this point +was highly fractured and not really + + align:start position:0% +was highly fractured and not really + + + align:start position:0% +was highly fractured and not really +functioning very easily because Tokyo + + align:start position:0% +functioning very easily because Tokyo + + + align:start position:0% +functioning very easily because Tokyo +had been leveled some parts of the + + align:start position:0% +had been leveled some parts of the + + + align:start position:0% +had been leveled some parts of the +Japanese government were sending out + + align:start position:0% +Japanese government were sending out + + + align:start position:0% +Japanese government were sending out +feelers to try to see if a neutral third + + align:start position:0% +feelers to try to see if a neutral third + + + align:start position:0% +feelers to try to see if a neutral third +party could begin peace negotiations or + + align:start position:0% +party could begin peace negotiations or + + + align:start position:0% +party could begin peace negotiations or +you know negotiations and the fighting + + align:start position:0% +you know negotiations and the fighting + + + align:start position:0% +you know negotiations and the fighting +it's not clear that they had the + + align:start position:0% +it's not clear that they had the + + + align:start position:0% +it's not clear that they had the +authority to speak for the Emperor who + + align:start position:0% +authority to speak for the Emperor who + + + align:start position:0% +authority to speak for the Emperor who +was refusing to step down and that was + + align:start position:0% +was refusing to step down and that was + + + align:start position:0% +was refusing to step down and that was +part of this unconditional surrender + + align:start position:0% +part of this unconditional surrender + + + align:start position:0% +part of this unconditional surrender +um + + align:start position:0% +um + + + align:start position:0% +um +so on so it's not clear + + align:start position:0% +so on so it's not clear + + + align:start position:0% +so on so it's not clear +if that represented sort of the what + + align:start position:0% +if that represented sort of the what + + + align:start position:0% +if that represented sort of the what +fraction of the then existing Japanese + + align:start position:0% +fraction of the then existing Japanese + + + align:start position:0% +fraction of the then existing Japanese +government that represented it's also + + align:start position:0% +government that represented it's also + + + align:start position:0% +government that represented it's also +not clear how far that ever got but + + align:start position:0% +not clear how far that ever got but + + + align:start position:0% +not clear how far that ever got but +there was some there indeed was some + + align:start position:0% +there was some there indeed was some + + + align:start position:0% +there was some there indeed was some +evidence that some highly placed members + + align:start position:0% +evidence that some highly placed members + + + align:start position:0% +evidence that some highly placed members +of the Japanese government before the + + align:start position:0% +of the Japanese government before the + + + align:start position:0% +of the Japanese government before the +bombings of Hiroshima Nagasaki were + + align:start position:0% +bombings of Hiroshima Nagasaki were + + + align:start position:0% +bombings of Hiroshima Nagasaki were +seeking to start basically um + + align:start position:0% +seeking to start basically um + + + align:start position:0% +seeking to start basically um +negotiations they were seeking a third + + align:start position:0% +negotiations they were seeking a third + + + align:start position:0% +negotiations they were seeking a third +party who might broker them and again + + align:start position:0% +party who might broker them and again + + + align:start position:0% +party who might broker them and again +that doesn't mean they were on the verge + + align:start position:0% +that doesn't mean they were on the verge + + + align:start position:0% +that doesn't mean they were on the verge +of surrender what seems to be more clear + + align:start position:0% +of surrender what seems to be more clear + + + align:start position:0% +of surrender what seems to be more clear +than anything else from these other + + align:start position:0% +than anything else from these other + + + align:start position:0% +than anything else from these other +Scholars not my own work but I've + + align:start position:0% +Scholars not my own work but I've + + + align:start position:0% +Scholars not my own work but I've +learned from other people who looked as + + align:start position:0% +learned from other people who looked as + + + align:start position:0% +learned from other people who looked as +much more carefully so it was just + + align:start position:0% +much more carefully so it was just + + + align:start position:0% +much more carefully so it was just +complete disarray + + align:start position:0% +complete disarray + + + align:start position:0% +complete disarray +um I mean Washington DC was not subject + + align:start position:0% +um I mean Washington DC was not subject + + + align:start position:0% +um I mean Washington DC was not subject +to that kind of bombardment and so there + + align:start position:0% +to that kind of bombardment and so there + + + align:start position:0% +to that kind of bombardment and so there +was something like a functioning chain + + align:start position:0% +was something like a functioning chain + + + align:start position:0% +was something like a functioning chain +of command and something like you know a + + align:start position:0% +of command and something like you know a + + + align:start position:0% +of command and something like you know a +fractious but still functioning you know + + align:start position:0% +fractious but still functioning you know + + + align:start position:0% +fractious but still functioning you know +kind of series of decision makers who + + align:start position:0% +kind of series of decision makers who + + + align:start position:0% +kind of series of decision makers who +could disagree but nonetheless act on + + align:start position:0% +could disagree but nonetheless act on + + + align:start position:0% +could disagree but nonetheless act on +behalf of a functioning government I + + align:start position:0% +behalf of a functioning government I + + + align:start position:0% +behalf of a functioning government I +think not much of that was functioning + + align:start position:0% +think not much of that was functioning + + + align:start position:0% +think not much of that was functioning +the same way in Japan by that point of + + align:start position:0% +the same way in Japan by that point of + + + align:start position:0% +the same way in Japan by that point of +the war because of things like the + + align:start position:0% +the war because of things like the + + + align:start position:0% +the war because of things like the +enormous disruptions from the from the + + align:start position:0% +enormous disruptions from the from the + + + align:start position:0% +enormous disruptions from the from the +incendiary bombing + + align:start position:0% +incendiary bombing + + + align:start position:0% +incendiary bombing +there were different factions as they're + + align:start position:0% +there were different factions as they're + + + align:start position:0% +there were different factions as they're +off as well might expect there were + + align:start position:0% +off as well might expect there were + + + align:start position:0% +off as well might expect there were +different factions of the US and in + + align:start position:0% +different factions of the US and in + + + align:start position:0% +different factions of the US and in +Britain there are different factions + + align:start position:0% +Britain there are different factions + + + align:start position:0% +Britain there are different factions +within Japan and it wasn't just kind of + + align:start position:0% +within Japan and it wasn't just kind of + + + align:start position:0% +within Japan and it wasn't just kind of +military civilian there were different + + align:start position:0% +military civilian there were different + + + align:start position:0% +military civilian there were different +kind of complicated + + align:start position:0% +kind of complicated + + + align:start position:0% +kind of complicated +um different kind of loyalties and and + + align:start position:0% +um different kind of loyalties and and + + + align:start position:0% +um different kind of loyalties and and +groups and so it was it's not clear who + + align:start position:0% +groups and so it was it's not clear who + + + align:start position:0% +groups and so it was it's not clear who +was speaking for whom and if they even + + align:start position:0% +was speaking for whom and if they even + + + align:start position:0% +was speaking for whom and if they even +were capable of having the equivalent of + + align:start position:0% +were capable of having the equivalent of + + + align:start position:0% +were capable of having the equivalent of +like a kind of full cabinet meeting the + + align:start position:0% +like a kind of full cabinet meeting the + + + align:start position:0% +like a kind of full cabinet meeting the +way we might expect in a U.S context so + + align:start position:0% +way we might expect in a U.S context so + + + align:start position:0% +way we might expect in a U.S context so +that's again so it's a great question + + align:start position:0% +that's again so it's a great question + + + align:start position:0% +that's again so it's a great question +Alex because and unfortunately the + + align:start position:0% +Alex because and unfortunately the + + + align:start position:0% +Alex because and unfortunately the +answer again is like oh gosh it's + + align:start position:0% +answer again is like oh gosh it's + + + align:start position:0% +answer again is like oh gosh it's +complicated so with the fullness of time + + align:start position:0% +complicated so with the fullness of time + + + align:start position:0% +complicated so with the fullness of time +evidence has come out that there were + + align:start position:0% +evidence has come out that there were + + + align:start position:0% +evidence has come out that there were +some parties looking to do some things + + align:start position:0% +some parties looking to do some things + + + align:start position:0% +some parties looking to do some things +what's not at all clear and maybe wasn't + + align:start position:0% +what's not at all clear and maybe wasn't + + + align:start position:0% +what's not at all clear and maybe wasn't +clear even at the time was in a sense + + align:start position:0% +clear even at the time was in a sense + + + align:start position:0% +clear even at the time was in a sense +who would that have carried the day who + + align:start position:0% +who would that have carried the day who + + + align:start position:0% +who would that have carried the day who +for who were they speaking on behalf of + + align:start position:0% +for who were they speaking on behalf of + + + align:start position:0% +for who were they speaking on behalf of +who had the authority at the time + + align:start position:0% +who had the authority at the time + + + align:start position:0% +who had the authority at the time +because I think that had gotten very + + align:start position:0% +because I think that had gotten very + + + align:start position:0% +because I think that had gotten very +very + + align:start position:0% +very + + + align:start position:0% +very +um again let's just say non-trivial + + align:start position:0% +um again let's just say non-trivial + + + align:start position:0% +um again let's just say non-trivial +so it's a great it's a great great + + align:start position:0% +so it's a great it's a great great + + + align:start position:0% +so it's a great it's a great great +question + + align:start position:0% + + + + align:start position:0% + +sure yeah no the great question + + align:start position:0% +sure yeah no the great question + + + align:start position:0% +sure yeah no the great question +a lot lot has been written about the + + align:start position:0% +a lot lot has been written about the + + + align:start position:0% +a lot lot has been written about the +Oppenheimer um Affair let's say the + + align:start position:0% +Oppenheimer um Affair let's say the + + + align:start position:0% +Oppenheimer um Affair let's say the +Oppenheimer hearing + + align:start position:0% +Oppenheimer hearing + + + align:start position:0% +Oppenheimer hearing +um + + align:start position:0% +um + + + align:start position:0% +um +over the years again people keep + + align:start position:0% +over the years again people keep + + + align:start position:0% +over the years again people keep +revisiting it as more and more becomes + + align:start position:0% +revisiting it as more and more becomes + + + align:start position:0% +revisiting it as more and more becomes +Declassified more people are interviewed + + align:start position:0% +Declassified more people are interviewed + + + align:start position:0% +Declassified more people are interviewed +and you know there's a lot this 100th + + align:start position:0% +and you know there's a lot this 100th + + + align:start position:0% +and you know there's a lot this 100th +anniversary of oppenheimer's birth was + + align:start position:0% +anniversary of oppenheimer's birth was + + + align:start position:0% +anniversary of oppenheimer's birth was +2004. and over the 12 months of his + + align:start position:0% +2004. and over the 12 months of his + + + align:start position:0% +2004. and over the 12 months of his +Centennial birth year there were 12 like + + align:start position:0% +Centennial birth year there were 12 like + + + align:start position:0% +Centennial birth year there were 12 like +like one per month 12 full-length + + align:start position:0% +like one per month 12 full-length + + + align:start position:0% +like one per month 12 full-length +biographies published just in that year + + align:start position:0% +biographies published just in that year + + + align:start position:0% +biographies published just in that year +at least 12 did I count that could have + + align:start position:0% +at least 12 did I count that could have + + + align:start position:0% +at least 12 did I count that could have +been more so I mean when I say there's + + align:start position:0% +been more so I mean when I say there's + + + align:start position:0% +been more so I mean when I say there's +like an Oppenheimer industry pouring + + align:start position:0% +like an Oppenheimer industry pouring + + + align:start position:0% +like an Oppenheimer industry pouring +over this that's that's what I mean huge + + align:start position:0% +over this that's that's what I mean huge + + + align:start position:0% +over this that's that's what I mean huge +huge um amount of study of this + + align:start position:0% +huge um amount of study of this + + + align:start position:0% +huge um amount of study of this +so + + align:start position:0% +so + + + align:start position:0% +so +let me just say briefly therefore + + align:start position:0% +let me just say briefly therefore + + + align:start position:0% +let me just say briefly therefore +instead of going on for hours + + align:start position:0% +instead of going on for hours + + + align:start position:0% +instead of going on for hours +um and again we'll talk a little bit + + align:start position:0% +um and again we'll talk a little bit + + + align:start position:0% +um and again we'll talk a little bit +about this also in Wednesday's class + + align:start position:0% +about this also in Wednesday's class + + + align:start position:0% +about this also in Wednesday's class +Oppenheimer uh you know ended the war + + align:start position:0% +Oppenheimer uh you know ended the war + + + align:start position:0% +Oppenheimer uh you know ended the war +um really as seen as as the person who + + align:start position:0% +um really as seen as as the person who + + + align:start position:0% +um really as seen as as the person who +built the bomb which is um you know + + align:start position:0% +built the bomb which is um you know + + + align:start position:0% +built the bomb which is um you know +not historically accurate the the + + align:start position:0% +not historically accurate the the + + + align:start position:0% +not historically accurate the the +Manhattan Project had 125 000 people and + + align:start position:0% +Manhattan Project had 125 000 people and + + + align:start position:0% +Manhattan Project had 125 000 people and +even the so-called Inner Circle was you + + align:start position:0% +even the so-called Inner Circle was you + + + align:start position:0% +even the so-called Inner Circle was you +know many many people not just one or + + align:start position:0% +know many many people not just one or + + + align:start position:0% +know many many people not just one or +two but he really became the kind of + + align:start position:0% +two but he really became the kind of + + + align:start position:0% +two but he really became the kind of +face of it and that became both for good + + align:start position:0% +face of it and that became both for good + + + align:start position:0% +face of it and that became both for good +and for ill I mean he was seen he was + + align:start position:0% +and for ill I mean he was seen he was + + + align:start position:0% +and for ill I mean he was seen he was +treated as a hero for for many people + + align:start position:0% +treated as a hero for for many people + + + align:start position:0% +treated as a hero for for many people +who thought that the bomb had ended the + + align:start position:0% +who thought that the bomb had ended the + + + align:start position:0% +who thought that the bomb had ended the +war and therefore saved lives which was + + align:start position:0% +war and therefore saved lives which was + + + align:start position:0% +war and therefore saved lives which was +a dominant interpretation uh soon after + + align:start position:0% +a dominant interpretation uh soon after + + + align:start position:0% +a dominant interpretation uh soon after +the war in the United States + + align:start position:0% +the war in the United States + + + align:start position:0% +the war in the United States +he was seen as this kind of Wizardly you + + align:start position:0% +he was seen as this kind of Wizardly you + + + align:start position:0% +he was seen as this kind of Wizardly you +know philosopher king like the film says + + align:start position:0% +know philosopher king like the film says + + + align:start position:0% +know philosopher king like the film says +who had made it happen uh despite all + + align:start position:0% +who had made it happen uh despite all + + + align:start position:0% +who had made it happen uh despite all +the odds + + align:start position:0% +the odds + + + align:start position:0% +the odds +I know they hadn't it also made some + + align:start position:0% +I know they hadn't it also made some + + + align:start position:0% +I know they hadn't it also made some +people think that he was uniquely + + align:start position:0% +people think that he was uniquely + + + align:start position:0% +people think that he was uniquely +dangerous if there is a kind of single + + align:start position:0% +dangerous if there is a kind of single + + + align:start position:0% +dangerous if there is a kind of single +Mastermind or a single set of secrets + + align:start position:0% +Mastermind or a single set of secrets + + + align:start position:0% +Mastermind or a single set of secrets +with which these things be made uh then + + align:start position:0% +with which these things be made uh then + + + align:start position:0% +with which these things be made uh then +then that invites the extra scrutiny + + align:start position:0% +then that invites the extra scrutiny + + + align:start position:0% +then that invites the extra scrutiny +right and there's something this is + + align:start position:0% +right and there's something this is + + + align:start position:0% +right and there's something this is +something we'll talk a bit more in + + align:start position:0% +something we'll talk a bit more in + + + align:start position:0% +something we'll talk a bit more in +Wednesday's class + + align:start position:0% +Wednesday's class + + + align:start position:0% +Wednesday's class +so there was a lot of scrutiny as the + + align:start position:0% +so there was a lot of scrutiny as the + + + align:start position:0% +so there was a lot of scrutiny as the +political assumptions and fortunes and + + align:start position:0% +political assumptions and fortunes and + + + align:start position:0% +political assumptions and fortunes and +kind of groups in or out of power within + + align:start position:0% +kind of groups in or out of power within + + + align:start position:0% +kind of groups in or out of power within +the US and elsewhere shifted after the + + align:start position:0% +the US and elsewhere shifted after the + + + align:start position:0% +the US and elsewhere shifted after the +war + + align:start position:0% +war + + + align:start position:0% +war +Oppenheimer you know kind of had made a + + align:start position:0% +Oppenheimer you know kind of had made a + + + align:start position:0% +Oppenheimer you know kind of had made a +lot of uh um enemies along the way + + align:start position:0% +lot of uh um enemies along the way + + + align:start position:0% +lot of uh um enemies along the way +because he was very smart and never ever + + align:start position:0% +because he was very smart and never ever + + + align:start position:0% +because he was very smart and never ever +ever shy about letting everyone know + + align:start position:0% +ever shy about letting everyone know + + + align:start position:0% +ever shy about letting everyone know +just how smart he was he could be + + align:start position:0% +just how smart he was he could be + + + align:start position:0% +just how smart he was he could be +terrifically cutting I mean just + + align:start position:0% +terrifically cutting I mean just + + + align:start position:0% +terrifically cutting I mean just +mercilessly mocking of people whom he + + align:start position:0% +mercilessly mocking of people whom he + + + align:start position:0% +mercilessly mocking of people whom he +considered intellectually inferior + + align:start position:0% +considered intellectually inferior + + + align:start position:0% +considered intellectually inferior +sometimes as students often of people + + align:start position:0% +sometimes as students often of people + + + align:start position:0% +sometimes as students often of people +who were outside of his immediate circle + + align:start position:0% +who were outside of his immediate circle + + + align:start position:0% +who were outside of his immediate circle +so he was mean to physics students he + + align:start position:0% +so he was mean to physics students he + + + align:start position:0% +so he was mean to physics students he +was horrible to people like the + + align:start position:0% +was horrible to people like the + + + align:start position:0% +was horrible to people like the +secretary of the Air Force which is not + + align:start position:0% +secretary of the Air Force which is not + + + align:start position:0% +secretary of the Air Force which is not +a smart thing by the way if you're ever + + align:start position:0% +a smart thing by the way if you're ever + + + align:start position:0% +a smart thing by the way if you're ever +in the position of mock the secretary of + + align:start position:0% +in the position of mock the secretary of + + + align:start position:0% +in the position of mock the secretary of +the Air Force let me advise you not to + + align:start position:0% +the Air Force let me advise you not to + + + align:start position:0% +the Air Force let me advise you not to +do it but whatever whether the person + + align:start position:0% +do it but whatever whether the person + + + align:start position:0% +do it but whatever whether the person +deserves it or not + + align:start position:0% +deserves it or not + + + align:start position:0% +deserves it or not +so that Oppenheimer kept making enemies + + align:start position:0% +so that Oppenheimer kept making enemies + + + align:start position:0% +so that Oppenheimer kept making enemies +basically he was in the spotlight and + + align:start position:0% +basically he was in the spotlight and + + + align:start position:0% +basically he was in the spotlight and +that gave him the opportunity to shoot + + align:start position:0% +that gave him the opportunity to shoot + + + align:start position:0% +that gave him the opportunity to shoot +his mouth off a lot and much like + + align:start position:0% +his mouth off a lot and much like + + + align:start position:0% +his mouth off a lot and much like +Galileo you know a couple centuries + + align:start position:0% +Galileo you know a couple centuries + + + align:start position:0% +Galileo you know a couple centuries +earlier he was often adopting positions + + align:start position:0% +earlier he was often adopting positions + + + align:start position:0% +earlier he was often adopting positions +that one might find the perfectly + + align:start position:0% +that one might find the perfectly + + + align:start position:0% +that one might find the perfectly +reasonable defensible but defending them + + align:start position:0% +reasonable defensible but defending them + + + align:start position:0% +reasonable defensible but defending them +in a often very aggressive and kind of + + align:start position:0% +in a often very aggressive and kind of + + + align:start position:0% +in a often very aggressive and kind of +mocking sort of way + + align:start position:0% +mocking sort of way + + + align:start position:0% +mocking sort of way +Galileo and the pope Oppenheimer the + + align:start position:0% +Galileo and the pope Oppenheimer the + + + align:start position:0% +Galileo and the pope Oppenheimer the +secretary Air Force right not actually + + align:start position:0% +secretary Air Force right not actually + + + align:start position:0% +secretary Air Force right not actually +so dissimilar in some ways so I better + + align:start position:0% +so dissimilar in some ways so I better + + + align:start position:0% +so dissimilar in some ways so I better +start get started collecting a slew of + + align:start position:0% +start get started collecting a slew of + + + align:start position:0% +start get started collecting a slew of +really quite emboldened uh political uh + + align:start position:0% +really quite emboldened uh political uh + + + align:start position:0% +really quite emboldened uh political uh +you know enemies + + align:start position:0% +you know enemies + + + align:start position:0% +you know enemies +and he started giving advice on + + align:start position:0% +and he started giving advice on + + + align:start position:0% +and he started giving advice on +strategic steps for the nuclear Arsenal + + align:start position:0% +strategic steps for the nuclear Arsenal + + + align:start position:0% +strategic steps for the nuclear Arsenal +that many of them didn't like either and + + align:start position:0% +that many of them didn't like either and + + + align:start position:0% +that many of them didn't like either and +we'll talk a bit about this and there's + + align:start position:0% +we'll talk a bit about this and there's + + + align:start position:0% +we'll talk a bit about this and there's +a hint of that in the film as well so so + + align:start position:0% +a hint of that in the film as well so so + + + align:start position:0% +a hint of that in the film as well so so +in less than a decade he had then made a + + align:start position:0% +in less than a decade he had then made a + + + align:start position:0% +in less than a decade he had then made a +long series of quite powerful people who + + align:start position:0% +long series of quite powerful people who + + + align:start position:0% +long series of quite powerful people who +were pretty pretty ticked off it + + align:start position:0% +were pretty pretty ticked off it + + + align:start position:0% +were pretty pretty ticked off it +uh and so in some sense his hearing was + + align:start position:0% +uh and so in some sense his hearing was + + + align:start position:0% +uh and so in some sense his hearing was +I don't know if it was over determined + + align:start position:0% +I don't know if it was over determined + + + align:start position:0% +I don't know if it was over determined +but it wasn't actually such a shock the + + align:start position:0% +but it wasn't actually such a shock the + + + align:start position:0% +but it wasn't actually such a shock the +fact of the hearing the fact that people + + align:start position:0% +fact of the hearing the fact that people + + + align:start position:0% +fact of the hearing the fact that people +wanted to get him what was left out of + + align:start position:0% +wanted to get him what was left out of + + + align:start position:0% +wanted to get him what was left out of +the film and this was largely came to + + align:start position:0% +the film and this was largely came to + + + align:start position:0% +the film and this was largely came to +light in in more recent scholarships + + align:start position:0% +light in in more recent scholarships + + + align:start position:0% +light in in more recent scholarships +since the early 2000s + + align:start position:0% +since the early 2000s + + + align:start position:0% +since the early 2000s +uh is that Oppenheimer + + align:start position:0% +uh is that Oppenheimer + + + align:start position:0% +uh is that Oppenheimer +you know frankly was trying to kind of + + align:start position:0% +you know frankly was trying to kind of + + + align:start position:0% +you know frankly was trying to kind of +hold on for a long time + + align:start position:0% +hold on for a long time + + + align:start position:0% +hold on for a long time +uh he + + align:start position:0% +uh he + + + align:start position:0% +uh he +he as we now know from declass from + + align:start position:0% +he as we now know from declass from + + + align:start position:0% +he as we now know from declass from +since Declassified documents he often + + align:start position:0% +since Declassified documents he often + + + align:start position:0% +since Declassified documents he often +kind of sold a bunch of his own students + + align:start position:0% +kind of sold a bunch of his own students + + + align:start position:0% +kind of sold a bunch of his own students +out + + align:start position:0% +out + + + align:start position:0% +out +um he was very desperate to protect his + + align:start position:0% +um he was very desperate to protect his + + + align:start position:0% +um he was very desperate to protect his +younger brother Frank who does feature a + + align:start position:0% +younger brother Frank who does feature a + + + align:start position:0% +younger brother Frank who does feature a +lot in the film Frank had been an + + align:start position:0% +lot in the film Frank had been an + + + align:start position:0% +lot in the film Frank had been an +explicit card carrying member of the + + align:start position:0% +explicit card carrying member of the + + + align:start position:0% +explicit card carrying member of the +Communist Party in the 30s not active + + align:start position:0% +Communist Party in the 30s not active + + + align:start position:0% +Communist Party in the 30s not active +but he joined the party as many many + + align:start position:0% +but he joined the party as many many + + + align:start position:0% +but he joined the party as many many +many many academics did in the US in the + + align:start position:0% +many many academics did in the US in the + + + align:start position:0% +many many academics did in the US in the +30s that wasn't so unusual + + align:start position:0% +30s that wasn't so unusual + + + align:start position:0% +30s that wasn't so unusual +but that made Frank an easy target + + align:start position:0% +but that made Frank an easy target + + + align:start position:0% +but that made Frank an easy target +and so it looks like not infrequently + + align:start position:0% +and so it looks like not infrequently + + + align:start position:0% +and so it looks like not infrequently +Robert Oppenheimer would kind of try to + + align:start position:0% +Robert Oppenheimer would kind of try to + + + align:start position:0% +Robert Oppenheimer would kind of try to +cut these deals he thought he could + + align:start position:0% +cut these deals he thought he could + + + align:start position:0% +cut these deals he thought he could +control the situation like don't bother + + align:start position:0% +control the situation like don't bother + + + align:start position:0% +control the situation like don't bother +my brother he's actually no harm but you + + align:start position:0% +my brother he's actually no harm but you + + + align:start position:0% +my brother he's actually no harm but you +want it but you know what those guys + + align:start position:0% +want it but you know what those guys + + + align:start position:0% +want it but you know what those guys +they're Reds as well and often those + + align:start position:0% +they're Reds as well and often those + + + align:start position:0% +they're Reds as well and often those +guys he'd point to where somebody's own + + align:start position:0% +guys he'd point to where somebody's own + + + align:start position:0% +guys he'd point to where somebody's own +former PhD students behind their backs + + align:start position:0% +former PhD students behind their backs + + + align:start position:0% +former PhD students behind their backs +so he was doing a lot of these things as + + align:start position:0% +so he was doing a lot of these things as + + + align:start position:0% +so he was doing a lot of these things as +we now know + + align:start position:0% +we now know + + + align:start position:0% +we now know +um that that that paint a more + + align:start position:0% +um that that that paint a more + + + align:start position:0% +um that that that paint a more +complicated frankly human picture than + + align:start position:0% +complicated frankly human picture than + + + align:start position:0% +complicated frankly human picture than +the kind of saintly martyr that often + + align:start position:0% +the kind of saintly martyr that often + + + align:start position:0% +the kind of saintly martyr that often +comes up even I think in this film + + align:start position:0% +comes up even I think in this film + + + align:start position:0% +comes up even I think in this film +actually + + align:start position:0% +actually + + + align:start position:0% +actually +so his his own political + + align:start position:0% +so his his own political + + + align:start position:0% +so his his own political +skills were not quite as Sterling as he + + align:start position:0% +skills were not quite as Sterling as he + + + align:start position:0% +skills were not quite as Sterling as he +often thought his way of coping with + + align:start position:0% +often thought his way of coping with + + + align:start position:0% +often thought his way of coping with +fast-changing political wins were not + + align:start position:0% +fast-changing political wins were not + + + align:start position:0% +fast-changing political wins were not +what I think any of us would hope we + + align:start position:0% +what I think any of us would hope we + + + align:start position:0% +what I think any of us would hope we +would do if in that situation I don't + + align:start position:0% +would do if in that situation I don't + + + align:start position:0% +would do if in that situation I don't +know how how we would do but it didn't + + align:start position:0% +know how how we would do but it didn't + + + align:start position:0% +know how how we would do but it didn't +oh didn't always look great as we now + + align:start position:0% +oh didn't always look great as we now + + + align:start position:0% +oh didn't always look great as we now +know + + align:start position:0% +know + + + align:start position:0% +know +and it comes off as almost a kind of + + align:start position:0% +and it comes off as almost a kind of + + + align:start position:0% +and it comes off as almost a kind of +grasping at least in some of these + + align:start position:0% +grasping at least in some of these + + + align:start position:0% +grasping at least in some of these +scenarios so Oppenheimer becomes frankly + + align:start position:0% +scenarios so Oppenheimer becomes frankly + + + align:start position:0% +scenarios so Oppenheimer becomes frankly +more interesting and also just much more + + align:start position:0% +more interesting and also just much more + + + align:start position:0% +more interesting and also just much more +human there was a reason to write at + + align:start position:0% +human there was a reason to write at + + + align:start position:0% +human there was a reason to write at +least six of those 12 biographies in + + align:start position:0% +least six of those 12 biographies in + + + align:start position:0% +least six of those 12 biographies in +2004 and some there's a lot of + + align:start position:0% +2004 and some there's a lot of + + + align:start position:0% +2004 and some there's a lot of +Dimensions to this person and and a + + align:start position:0% +Dimensions to this person and and a + + + align:start position:0% +Dimensions to this person and and a +standing for for larger fast moving + + align:start position:0% +standing for for larger fast moving + + + align:start position:0% +standing for for larger fast moving +currents within certainly within the US + + align:start position:0% +currents within certainly within the US + + + align:start position:0% +currents within certainly within the US +and I think beyond that as well + + align:start position:0% +and I think beyond that as well + + + align:start position:0% +and I think beyond that as well +so um so so I I'd be glad to talk more + + align:start position:0% +so um so so I I'd be glad to talk more + + + align:start position:0% +so um so so I I'd be glad to talk more +about Oppenheimer but let me shift to + + align:start position:0% +about Oppenheimer but let me shift to + + + align:start position:0% +about Oppenheimer but let me shift to +teller Taylor was also a very early uh + + align:start position:0% +teller Taylor was also a very early uh + + + align:start position:0% +teller Taylor was also a very early uh +recruit very active at wartime Los + + align:start position:0% +recruit very active at wartime Los + + + align:start position:0% +recruit very active at wartime Los +Alamos and um + + align:start position:0% +Alamos and um + + + align:start position:0% +Alamos and um +already a very accomplished theoretical + + align:start position:0% +already a very accomplished theoretical + + + align:start position:0% +already a very accomplished theoretical +physicist they all kind of knew that + + align:start position:0% +physicist they all kind of knew that + + + align:start position:0% +physicist they all kind of knew that +generation they all knew each other it's + + align:start position:0% +generation they all knew each other it's + + + align:start position:0% +generation they all knew each other it's +a small community before them he's a he + + align:start position:0% +a small community before them he's a he + + + align:start position:0% +a small community before them he's a he +was an immigrant he was a Hungarian uh + + align:start position:0% +was an immigrant he was a Hungarian uh + + + align:start position:0% +was an immigrant he was a Hungarian uh +Jewish person who fled you know um + + align:start position:0% +Jewish person who fled you know um + + + align:start position:0% +Jewish person who fled you know um +fascism he'd been studying in Germany + + align:start position:0% +fascism he'd been studying in Germany + + + align:start position:0% +fascism he'd been studying in Germany +like many of them so he had very good + + align:start position:0% +like many of them so he had very good + + + align:start position:0% +like many of them so he had very good +reason to come to the United States in + + align:start position:0% +reason to come to the United States in + + + align:start position:0% +reason to come to the United States in +the 30s uh and and was hired here in + + align:start position:0% +the 30s uh and and was hired here in + + + align:start position:0% +the 30s uh and and was hired here in +that wave that we talked previously + + align:start position:0% +that wave that we talked previously + + + align:start position:0% +that wave that we talked previously +about + + align:start position:0% +about + + + align:start position:0% +about +and he was very accomplished in a + + align:start position:0% +and he was very accomplished in a + + + align:start position:0% +and he was very accomplished in a +particular very accomplished in nuclear + + align:start position:0% +particular very accomplished in nuclear + + + align:start position:0% +particular very accomplished in nuclear +physics + + align:start position:0% +physics + + + align:start position:0% +physics +um kind of ahead of the curve on that he + + align:start position:0% +um kind of ahead of the curve on that he + + + align:start position:0% +um kind of ahead of the curve on that he +also I think because of his experiences + + align:start position:0% +also I think because of his experiences + + + align:start position:0% +also I think because of his experiences +with these very short-lived communist + + align:start position:0% +with these very short-lived communist + + + align:start position:0% +with these very short-lived communist +and socialist governments in Central + + align:start position:0% +and socialist governments in Central + + + align:start position:0% +and socialist governments in Central +Europe after the end of the first world + + align:start position:0% +Europe after the end of the first world + + + align:start position:0% +Europe after the end of the first world +war a bunch of these immigrants like + + align:start position:0% +war a bunch of these immigrants like + + + align:start position:0% +war a bunch of these immigrants like +teller had experienced what they + + align:start position:0% +teller had experienced what they + + + align:start position:0% +teller had experienced what they +considered just really scary kind of + + align:start position:0% +considered just really scary kind of + + + align:start position:0% +considered just really scary kind of +just chaos in their Reckoning right + + align:start position:0% +just chaos in their Reckoning right + + + align:start position:0% +just chaos in their Reckoning right +after the end of the first world war + + align:start position:0% +after the end of the first world war + + + align:start position:0% +after the end of the first world war +when they were basically late teens or + + align:start position:0% +when they were basically late teens or + + + align:start position:0% +when they were basically late teens or +early 20s a lot of them from + + align:start position:0% +early 20s a lot of them from + + + align:start position:0% +early 20s a lot of them from +self-proclaimed Communists or other + + align:start position:0% +self-proclaimed Communists or other + + + align:start position:0% +self-proclaimed Communists or other +socialists short-lived there was huge + + align:start position:0% +socialists short-lived there was huge + + + align:start position:0% +socialists short-lived there was huge +back and forth the far left the far + + align:start position:0% +back and forth the far left the far + + + align:start position:0% +back and forth the far left the far +right the far left far right militias in + + align:start position:0% +right the far left far right militias in + + + align:start position:0% +right the far left far right militias in +the streets hopefully hopefully nothing + + align:start position:0% +the streets hopefully hopefully nothing + + + align:start position:0% +the streets hopefully hopefully nothing +that any of us will experience uh soon + + align:start position:0% +that any of us will experience uh soon + + + align:start position:0% +that any of us will experience uh soon +or not so soon so teller was a devoted + + align:start position:0% +or not so soon so teller was a devoted + + + align:start position:0% +or not so soon so teller was a devoted +anti-communist before he landed on U.S + + align:start position:0% +anti-communist before he landed on U.S + + + align:start position:0% +anti-communist before he landed on U.S +Shore from I think really not because he + + align:start position:0% +Shore from I think really not because he + + + align:start position:0% +Shore from I think really not because he +read you know like um Marx and was + + align:start position:0% +read you know like um Marx and was + + + align:start position:0% +read you know like um Marx and was +horrified because he'd seen this blood + + align:start position:0% +horrified because he'd seen this blood + + + align:start position:0% +horrified because he'd seen this blood +in the streets kind of fights in the + + align:start position:0% +in the streets kind of fights in the + + + align:start position:0% +in the streets kind of fights in the +1919 teens + + align:start position:0% +1919 teens + + + align:start position:0% +1919 teens +so he was very and many of the folks who + + align:start position:0% +so he was very and many of the folks who + + + align:start position:0% +so he was very and many of the folks who +came with him from that era shared those + + align:start position:0% +came with him from that era shared those + + + align:start position:0% +came with him from that era shared those +sentiments so he was very kind of um we + + align:start position:0% +sentiments so he was very kind of um we + + + align:start position:0% +sentiments so he was very kind of um we +might say jingoistic his adopted home + + align:start position:0% +might say jingoistic his adopted home + + + align:start position:0% +might say jingoistic his adopted home +really should develop the most + + align:start position:0% +really should develop the most + + + align:start position:0% +really should develop the most +significant weapons we really should + + align:start position:0% +significant weapons we really should + + + align:start position:0% +significant weapons we really should +keep all these other kind of bad people + + align:start position:0% +keep all these other kind of bad people + + + align:start position:0% +keep all these other kind of bad people +at Bay was a rough paraphrase + + align:start position:0% +at Bay was a rough paraphrase + + + align:start position:0% +at Bay was a rough paraphrase +now he spent the war warriors at Los + + align:start position:0% +now he spent the war warriors at Los + + + align:start position:0% +now he spent the war warriors at Los +Alamos trying to argue that the fission + + align:start position:0% +Alamos trying to argue that the fission + + + align:start position:0% +Alamos trying to argue that the fission +bomb was small potatoes and why are we + + align:start position:0% +bomb was small potatoes and why are we + + + align:start position:0% +bomb was small potatoes and why are we +wasting our time with this we should + + align:start position:0% +wasting our time with this we should + + + align:start position:0% +wasting our time with this we should +actually be going for a fusion bomb of + + align:start position:0% +actually be going for a fusion bomb of + + + align:start position:0% +actually be going for a fusion bomb of +the sort we will talk briefly about on + + align:start position:0% +the sort we will talk briefly about on + + + align:start position:0% +the sort we will talk briefly about on +Wednesday + + align:start position:0% +Wednesday + + + align:start position:0% +Wednesday +so he kept butting heads with leadership + + align:start position:0% +so he kept butting heads with leadership + + + align:start position:0% +so he kept butting heads with leadership +because he thought they had the wrong + + align:start position:0% +because he thought they had the wrong + + + align:start position:0% +because he thought they had the wrong +priorities this was at a time when there + + align:start position:0% +priorities this was at a time when there + + + align:start position:0% +priorities this was at a time when there +were still like micrograms of plutonium + + align:start position:0% +were still like micrograms of plutonium + + + align:start position:0% +were still like micrograms of plutonium +on the planet no working device had been + + align:start position:0% +on the planet no working device had been + + + align:start position:0% +on the planet no working device had been +developed a little and tested and he's + + align:start position:0% +developed a little and tested and he's + + + align:start position:0% +developed a little and tested and he's +like what that's such a trivial task + + align:start position:0% +like what that's such a trivial task + + + align:start position:0% +like what that's such a trivial task +give me all the resources I want to + + align:start position:0% +give me all the resources I want to + + + align:start position:0% +give me all the resources I want to +build you know hydrogen + + align:start position:0% +build you know hydrogen + + + align:start position:0% +build you know hydrogen +he was very big strong fights about + + align:start position:0% +he was very big strong fights about + + + align:start position:0% +he was very big strong fights about +resources and priorities and so more or + + align:start position:0% +resources and priorities and so more or + + + align:start position:0% +resources and priorities and so more or +less kind of to appease him because he + + align:start position:0% +less kind of to appease him because he + + + align:start position:0% +less kind of to appease him because he +was a smart contributing member he was + + align:start position:0% +was a smart contributing member he was + + + align:start position:0% +was a smart contributing member he was +given a small little study group even + + align:start position:0% +given a small little study group even + + + align:start position:0% +given a small little study group even +during the War uh to work on Fusion + + align:start position:0% +during the War uh to work on Fusion + + + align:start position:0% +during the War uh to work on Fusion +weapons + + align:start position:0% +weapons + + + align:start position:0% +weapons +and I think even by his own Reckoning + + align:start position:0% +and I think even by his own Reckoning + + + align:start position:0% +and I think even by his own Reckoning +they got kind of nowhere but it was it + + align:start position:0% +they got kind of nowhere but it was it + + + align:start position:0% +they got kind of nowhere but it was it +was you know a study group to lay the + + align:start position:0% +was you know a study group to lay the + + + align:start position:0% +was you know a study group to lay the +seas in fact even before there was a Los + + align:start position:0% +seas in fact even before there was a Los + + + align:start position:0% +seas in fact even before there was a Los +Alamos laboratory he was arguing for + + align:start position:0% +Alamos laboratory he was arguing for + + + align:start position:0% +Alamos laboratory he was arguing for +delivery the very first discussion on + + align:start position:0% +delivery the very first discussion on + + + align:start position:0% +delivery the very first discussion on +Berkeley's campus with Oppenheimer and + + align:start position:0% +Berkeley's campus with Oppenheimer and + + + align:start position:0% +Berkeley's campus with Oppenheimer and +the rest that fission bombs would + + align:start position:0% +the rest that fission bombs would + + + align:start position:0% +the rest that fission bombs would +trivial we should be going right now + + align:start position:0% +trivial we should be going right now + + + align:start position:0% +trivial we should be going right now +from Summer 1942 into Fusion I mean that + + align:start position:0% +from Summer 1942 into Fusion I mean that + + + align:start position:0% +from Summer 1942 into Fusion I mean that +was his kind of eBay fix + + align:start position:0% +was his kind of eBay fix + + + align:start position:0% +was his kind of eBay fix +and after the war he becomes more and + + align:start position:0% +and after the war he becomes more and + + + align:start position:0% +and after the war he becomes more and +more uh he he's more and more listened + + align:start position:0% +more uh he he's more and more listened + + + align:start position:0% +more uh he he's more and more listened +to by the folks who are getting more and + + align:start position:0% +to by the folks who are getting more and + + + align:start position:0% +to by the folks who are getting more and +more impatient with Oppenheimer he's he + + align:start position:0% +more impatient with Oppenheimer he's he + + + align:start position:0% +more impatient with Oppenheimer he's he +seems like he has uh answers that many + + align:start position:0% +seems like he has uh answers that many + + + align:start position:0% +seems like he has uh answers that many +of the + + align:start position:0% +of the + + + align:start position:0% +of the +um you know kind of Air Force leadership + + align:start position:0% +um you know kind of Air Force leadership + + + align:start position:0% +um you know kind of Air Force leadership +after the war actually does want to hear + + align:start position:0% +after the war actually does want to hear + + + align:start position:0% +after the war actually does want to hear +they want to hear about bigger Bobs that + + align:start position:0% +they want to hear about bigger Bobs that + + + align:start position:0% +they want to hear about bigger Bobs that +would be under the control of the Air + + align:start position:0% +would be under the control of the Air + + + align:start position:0% +would be under the control of the Air +Force that would be the reason the Air + + align:start position:0% +Force that would be the reason the Air + + + align:start position:0% +Force that would be the reason the Air +Force be the most important you know + + align:start position:0% +Force be the most important you know + + + align:start position:0% +Force be the most important you know +service branch and all these things get + + align:start position:0% +service branch and all these things get + + + align:start position:0% +service branch and all these things get +tied up in kind of rivalries within the + + align:start position:0% +tied up in kind of rivalries within the + + + align:start position:0% +tied up in kind of rivalries within the +U.S uh infrastructure so teller's star + + align:start position:0% +U.S uh infrastructure so teller's star + + + align:start position:0% +U.S uh infrastructure so teller's star +sort of Rises basically at least he has + + align:start position:0% +sort of Rises basically at least he has + + + align:start position:0% +sort of Rises basically at least he has +more people listening to him after the + + align:start position:0% +more people listening to him after the + + + align:start position:0% +more people listening to him after the +war including uh he's very influential + + align:start position:0% +war including uh he's very influential + + + align:start position:0% +war including uh he's very influential +not him alone he was a big mover and + + align:start position:0% +not him alone he was a big mover and + + + align:start position:0% +not him alone he was a big mover and +getting a whole second weapons + + align:start position:0% +getting a whole second weapons + + + align:start position:0% +getting a whole second weapons +laboratory established the Livermore + + align:start position:0% +laboratory established the Livermore + + + align:start position:0% +laboratory established the Livermore +National Laboratory which has opened its + + align:start position:0% +National Laboratory which has opened its + + + align:start position:0% +National Laboratory which has opened its +doors in September of 1952 with the + + align:start position:0% +doors in September of 1952 with the + + + align:start position:0% +doors in September of 1952 with the +express purpose of working full tilt on + + align:start position:0% +express purpose of working full tilt on + + + align:start position:0% +express purpose of working full tilt on +on Fusion weapons + + align:start position:0% +on Fusion weapons + + + align:start position:0% +on Fusion weapons +um this kind of thing so he he's moving + + align:start position:0% +um this kind of thing so he he's moving + + + align:start position:0% +um this kind of thing so he he's moving +in that he does he did testify as you + + align:start position:0% +in that he does he did testify as you + + + align:start position:0% +in that he does he did testify as you +heard in the film uh at oppenheimer's + + align:start position:0% +heard in the film uh at oppenheimer's + + + align:start position:0% +heard in the film uh at oppenheimer's +Security hearing in a way that really + + align:start position:0% +Security hearing in a way that really + + + align:start position:0% +Security hearing in a way that really +when the transcript was published + + align:start position:0% +when the transcript was published + + + align:start position:0% +when the transcript was published +uh was seen as really devastating by + + align:start position:0% +uh was seen as really devastating by + + + align:start position:0% +uh was seen as really devastating by +many many members of the physics + + align:start position:0% +many many members of the physics + + + align:start position:0% +many many members of the physics +Community he doesn't come out and + + align:start position:0% +Community he doesn't come out and + + + align:start position:0% +Community he doesn't come out and +explicitly call Oppenheimer a communist + + align:start position:0% +explicitly call Oppenheimer a communist + + + align:start position:0% +explicitly call Oppenheimer a communist +or um you know a directly security risk + + align:start position:0% +or um you know a directly security risk + + + align:start position:0% +or um you know a directly security risk +which other people were calling it + + align:start position:0% +which other people were calling it + + + align:start position:0% +which other people were calling it +fairly unfairly but he says Oppenheimer + + align:start position:0% +fairly unfairly but he says Oppenheimer + + + align:start position:0% +fairly unfairly but he says Oppenheimer +is a complicated person which was not + + align:start position:0% +is a complicated person which was not + + + align:start position:0% +is a complicated person which was not +meant to be a compliment and and the + + align:start position:0% +meant to be a compliment and and the + + + align:start position:0% +meant to be a compliment and and the +famous line which I'll get pretty close + + align:start position:0% +famous line which I'll get pretty close + + + align:start position:0% +famous line which I'll get pretty close +teller says under oath I wish that the + + align:start position:0% +teller says under oath I wish that the + + + align:start position:0% +teller says under oath I wish that the +that these that these big important + + align:start position:0% +that these that these big important + + + align:start position:0% +that these that these big important +tasks were in hands I understood better + + align:start position:0% +tasks were in hands I understood better + + + align:start position:0% +tasks were in hands I understood better +so therefore could trust more he says I + + align:start position:0% +so therefore could trust more he says I + + + align:start position:0% +so therefore could trust more he says I +basically don't trust Oppenheimer + + align:start position:0% +basically don't trust Oppenheimer + + + align:start position:0% +basically don't trust Oppenheimer +because he is this kind of complicated + + align:start position:0% +because he is this kind of complicated + + + align:start position:0% +because he is this kind of complicated +maybe scheming kind of person + + align:start position:0% +maybe scheming kind of person + + + align:start position:0% +maybe scheming kind of person +as a teller it gives us basically + + align:start position:0% +as a teller it gives us basically + + + align:start position:0% +as a teller it gives us basically +damning what scene is damning testimony + + align:start position:0% +damning what scene is damning testimony + + + align:start position:0% +damning what scene is damning testimony +for for decades you know he outlived off + + align:start position:0% +for for decades you know he outlived off + + + align:start position:0% +for for decades you know he outlived off +100 decades for decades people wouldn't + + align:start position:0% +100 decades for decades people wouldn't + + + align:start position:0% +100 decades for decades people wouldn't +shake his hand would he'd come to give a + + align:start position:0% +shake his hand would he'd come to give a + + + align:start position:0% +shake his hand would he'd come to give a +physics colloquium it really was had a a + + align:start position:0% +physics colloquium it really was had a a + + + align:start position:0% +physics colloquium it really was had a a +a generation long impact on how people + + align:start position:0% +a generation long impact on how people + + + align:start position:0% +a generation long impact on how people +thought of him nonetheless in other + + align:start position:0% +thought of him nonetheless in other + + + align:start position:0% +thought of him nonetheless in other +circles many others couldn't get enough + + align:start position:0% +circles many others couldn't get enough + + + align:start position:0% +circles many others couldn't get enough +and so he he continued to have influence + + align:start position:0% +and so he he continued to have influence + + + align:start position:0% +and so he he continued to have influence +among certain U.S Administrations + + align:start position:0% +among certain U.S Administrations + + + align:start position:0% +among certain U.S Administrations +well past the 80s I mean uh really + + align:start position:0% +well past the 80s I mean uh really + + + align:start position:0% +well past the 80s I mean uh really +decades after uh the 40s and 50s so you + + align:start position:0% +decades after uh the 40s and 50s so you + + + align:start position:0% +decades after uh the 40s and 50s so you +know he he + + align:start position:0% +know he he + + + align:start position:0% +know he he +I + + align:start position:0% +I + + + align:start position:0% +I +it's easy I mean much like it's easy to + + align:start position:0% +it's easy I mean much like it's easy to + + + align:start position:0% +it's easy I mean much like it's easy to +venerate people like Niels Bohr oh World + + align:start position:0% +venerate people like Niels Bohr oh World + + + align:start position:0% +venerate people like Niels Bohr oh World +Government if only he could have carried + + align:start position:0% +Government if only he could have carried + + + align:start position:0% +Government if only he could have carried +the day he was like well I don't think + + align:start position:0% +the day he was like well I don't think + + + align:start position:0% +the day he was like well I don't think +it works that way teller is I think + + align:start position:0% +it works that way teller is I think + + + align:start position:0% +it works that way teller is I think +often vilified Often by the same people + + align:start position:0% +often vilified Often by the same people + + + align:start position:0% +often vilified Often by the same people +who want to see Heroes like Einstein + + align:start position:0% +who want to see Heroes like Einstein + + + align:start position:0% +who want to see Heroes like Einstein +born and Oppenheimer all these people + + align:start position:0% +born and Oppenheimer all these people + + + align:start position:0% +born and Oppenheimer all these people +are complicated and the world is + + align:start position:0% +are complicated and the world is + + + align:start position:0% +are complicated and the world is +complicated and I I don't want to leave + + align:start position:0% +complicated and I I don't want to leave + + + align:start position:0% +complicated and I I don't want to leave +the impression that teller was somehow + + align:start position:0% +the impression that teller was somehow + + + align:start position:0% +the impression that teller was somehow +like a a masterful demon right which + + align:start position:0% +like a a masterful demon right which + + + align:start position:0% +like a a masterful demon right which +he's often been cast as he certainly had + + align:start position:0% +he's often been cast as he certainly had + + + align:start position:0% +he's often been cast as he certainly had +very very different ideas about the + + align:start position:0% +very very different ideas about the + + + align:start position:0% +very very different ideas about the +scientist responsibility and about the + + align:start position:0% +scientist responsibility and about the + + + align:start position:0% +scientist responsibility and about the +geopolitical stature of the U.S + + align:start position:0% +geopolitical stature of the U.S + + + align:start position:0% +geopolitical stature of the U.S +vis-a-vis changes in Europe especially + + align:start position:0% +vis-a-vis changes in Europe especially + + + align:start position:0% +vis-a-vis changes in Europe especially +and he was just dogged I mean he was + + align:start position:0% +and he was just dogged I mean he was + + + align:start position:0% +and he was just dogged I mean he was +just undetervable uh with this kind of + + align:start position:0% +just undetervable uh with this kind of + + + align:start position:0% +just undetervable uh with this kind of +focus on more and more bigger fancy + + align:start position:0% +focus on more and more bigger fancy + + + align:start position:0% +focus on more and more bigger fancy +weapons and let's make them available + + align:start position:0% +weapons and let's make them available + + + align:start position:0% +weapons and let's make them available +you know more and more quickly so that + + align:start position:0% +you know more and more quickly so that + + + align:start position:0% +you know more and more quickly so that +that became the kind of symbol of this + + align:start position:0% +that became the kind of symbol of this + + + align:start position:0% +that became the kind of symbol of this +larger split within the community + + align:start position:0% +larger split within the community + + + align:start position:0% +larger split within the community +uh between the kind of Oppenheimer camp + + align:start position:0% +uh between the kind of Oppenheimer camp + + + align:start position:0% +uh between the kind of Oppenheimer camp +and the teller Camp ironically teller + + align:start position:0% +and the teller Camp ironically teller + + + align:start position:0% +and the teller Camp ironically teller +was being surveilled by the FBI just as + + align:start position:0% +was being surveilled by the FBI just as + + + align:start position:0% +was being surveilled by the FBI just as +much as Oppenheimer was they didn't + + align:start position:0% +much as Oppenheimer was they didn't + + + align:start position:0% +much as Oppenheimer was they didn't +trust this strange weirdo European Jew + + align:start position:0% +trust this strange weirdo European Jew + + + align:start position:0% +trust this strange weirdo European Jew +who is this guy he came from places + + align:start position:0% +who is this guy he came from places + + + align:start position:0% +who is this guy he came from places +where they're Communists I mean the FBI + + align:start position:0% +where they're Communists I mean the FBI + + + align:start position:0% +where they're Communists I mean the FBI +was really an overdrive in this period I + + align:start position:0% +was really an overdrive in this period I + + + align:start position:0% +was really an overdrive in this period I +say chuckling now it wasn't so funny and + + align:start position:0% +say chuckling now it wasn't so funny and + + + align:start position:0% +say chuckling now it wasn't so funny and +there are these amazing passages in his + + align:start position:0% +there are these amazing passages in his + + + align:start position:0% +there are these amazing passages in his +once classified and tellers once + + align:start position:0% +once classified and tellers once + + + align:start position:0% +once classified and tellers once +classified file saying we don't trust + + align:start position:0% +classified file saying we don't trust + + + align:start position:0% +classified file saying we don't trust +this guy we don't know who he's talking + + align:start position:0% +this guy we don't know who he's talking + + + align:start position:0% +this guy we don't know who he's talking +to he's no more trustworthy than + + align:start position:0% +to he's no more trustworthy than + + + align:start position:0% +to he's no more trustworthy than +Oppenheimer so you know it's a kind of + + align:start position:0% +Oppenheimer so you know it's a kind of + + + align:start position:0% +Oppenheimer so you know it's a kind of +I don't want to say it's a shell game + + align:start position:0% +I don't want to say it's a shell game + + + align:start position:0% +I don't want to say it's a shell game +but it wasn't like he was seen as + + align:start position:0% +but it wasn't like he was seen as + + + align:start position:0% +but it wasn't like he was seen as +unproblematic he was seen as someone who + + align:start position:0% +unproblematic he was seen as someone who + + + align:start position:0% +unproblematic he was seen as someone who +said the things that some other powerful + + align:start position:0% +said the things that some other powerful + + + align:start position:0% +said the things that some other powerful +powerful people wanted to hear more at + + align:start position:0% +powerful people wanted to hear more at + + + align:start position:0% +powerful people wanted to hear more at +that time I think I think he was useful + + align:start position:0% +that time I think I think he was useful + + + align:start position:0% +that time I think I think he was useful +as I think he earnestly believed that + + align:start position:0% +as I think he earnestly believed that + + + align:start position:0% +as I think he earnestly believed that +but he was also useful to frankly other + + align:start position:0% +but he was also useful to frankly other + + + align:start position:0% +but he was also useful to frankly other +people who who really did understand a + + align:start position:0% +people who who really did understand a + + + align:start position:0% +people who who really did understand a +bit more of the kind of hard power you + + align:start position:0% +bit more of the kind of hard power you + + + align:start position:0% +bit more of the kind of hard power you +know um + + align:start position:0% +know um + + + align:start position:0% +know um +power plays of of Cold War politics + + align:start position:0% +power plays of of Cold War politics + + + align:start position:0% +power plays of of Cold War politics +so I think told is also has much much + + align:start position:0% +so I think told is also has much much + + + align:start position:0% +so I think told is also has much much +less attention paid to him in the in the + + align:start position:0% +less attention paid to him in the in the + + + align:start position:0% +less attention paid to him in the in the +secondary literature uh even though he + + align:start position:0% +secondary literature uh even though he + + + align:start position:0% +secondary literature uh even though he +lived a much longer life it was involved + + align:start position:0% +lived a much longer life it was involved + + + align:start position:0% +lived a much longer life it was involved +in many more kind of + + align:start position:0% +in many more kind of + + + align:start position:0% +in many more kind of +unusual events + + align:start position:0% +unusual events + + + align:start position:0% +unusual events +um but I I honestly think it's a + + align:start position:0% +um but I I honestly think it's a + + + align:start position:0% +um but I I honestly think it's a +lingering sense that he was somehow just + + align:start position:0% +lingering sense that he was somehow just + + + align:start position:0% +lingering sense that he was somehow just +the bad guy he's been cast I think in a + + align:start position:0% +the bad guy he's been cast I think in a + + + align:start position:0% +the bad guy he's been cast I think in a +kind of one-dimensional role that I that + + align:start position:0% +kind of one-dimensional role that I that + + + align:start position:0% +kind of one-dimensional role that I that +I think you know there's just been less + + align:start position:0% +I think you know there's just been less + + + align:start position:0% +I think you know there's just been less +attention paid to the Nuance that we + + align:start position:0% +attention paid to the Nuance that we + + + align:start position:0% +attention paid to the Nuance that we +might now get to try to do for someone + + align:start position:0% +might now get to try to do for someone + + + align:start position:0% +might now get to try to do for someone +like oppenheim + + align:start position:0% + + + + align:start position:0% + +ER yeah yeah so we'll get we'll get a + + align:start position:0% +ER yeah yeah so we'll get we'll get a + + + align:start position:0% +ER yeah yeah so we'll get we'll get a +little into that it won't be the Chicago + + align:start position:0% +little into that it won't be the Chicago + + + align:start position:0% +little into that it won't be the Chicago +site uh but a little bit of that theme + + align:start position:0% +site uh but a little bit of that theme + + + align:start position:0% +site uh but a little bit of that theme +certainly comes up in the next film + + align:start position:0% +certainly comes up in the next film + + + align:start position:0% +certainly comes up in the next film +we'll watch basically a week from now + + align:start position:0% +we'll watch basically a week from now + + + align:start position:0% +we'll watch basically a week from now +and I'm going to figure out a way to + + align:start position:0% +and I'm going to figure out a way to + + + align:start position:0% +and I'm going to figure out a way to +make sure you can all see it through um + + align:start position:0% +make sure you can all see it through um + + + align:start position:0% +make sure you can all see it through um +the canvas site the film's called + + align:start position:0% +the canvas site the film's called + + + align:start position:0% +the canvas site the film's called +containment I think I mentioned it + + align:start position:0% +containment I think I mentioned it + + + align:start position:0% +containment I think I mentioned it +briefly um by by my friend and colleague + + align:start position:0% +briefly um by by my friend and colleague + + + align:start position:0% +briefly um by by my friend and colleague +and actually my former advisor + + align:start position:0% +and actually my former advisor + + + align:start position:0% +and actually my former advisor +Peter Gallison and some of his + + align:start position:0% +Peter Gallison and some of his + + + align:start position:0% +Peter Gallison and some of his +colleagues so it's much more recent view + + align:start position:0% +colleagues so it's much more recent view + + + align:start position:0% +colleagues so it's much more recent view +of some of the kind of nuclear legacies + + align:start position:0% +of some of the kind of nuclear legacies + + + align:start position:0% +of some of the kind of nuclear legacies +um in particular environmental and + + align:start position:0% +um in particular environmental and + + + align:start position:0% +um in particular environmental and +radiological + + align:start position:0% +radiological + + + align:start position:0% +radiological +um and not just of the wartime but of + + align:start position:0% +um and not just of the wartime but of + + + align:start position:0% +um and not just of the wartime but of +the of the kind of Cold War uh period + + align:start position:0% +the of the kind of Cold War uh period + + + align:start position:0% +the of the kind of Cold War uh period +ever since in some sense still going on + + align:start position:0% +ever since in some sense still going on + + + align:start position:0% +ever since in some sense still going on +so that uh you know how does one handle + + align:start position:0% +so that uh you know how does one handle + + + align:start position:0% +so that uh you know how does one handle +uh waste byproducts of of Civilian + + align:start position:0% +uh waste byproducts of of Civilian + + + align:start position:0% +uh waste byproducts of of Civilian +nuclear power let alone nuclear above + + align:start position:0% +nuclear power let alone nuclear above + + + align:start position:0% +nuclear power let alone nuclear above +ground nuclear testing when some of + + align:start position:0% +ground nuclear testing when some of + + + align:start position:0% +ground nuclear testing when some of +these very very deeply dangerous + + align:start position:0% +these very very deeply dangerous + + + align:start position:0% +these very very deeply dangerous +poisonous Isotopes have half-lives in + + align:start position:0% +poisonous Isotopes have half-lives in + + + align:start position:0% +poisonous Isotopes have half-lives in +the tens or even hundreds of thousands + + align:start position:0% +the tens or even hundreds of thousands + + + align:start position:0% +the tens or even hundreds of thousands +of years so this stuff isn't going away + + align:start position:0% +of years so this stuff isn't going away + + + align:start position:0% +of years so this stuff isn't going away +anytime soon uh to put in mildly and so + + align:start position:0% +anytime soon uh to put in mildly and so + + + align:start position:0% +anytime soon uh to put in mildly and so +that's the kind of thing that that the + + align:start position:0% +that's the kind of thing that that the + + + align:start position:0% +that's the kind of thing that that the +new film The more recent film + + align:start position:0% +new film The more recent film + + + align:start position:0% +new film The more recent film +kind of grapples with and we'll we'll + + align:start position:0% +kind of grapples with and we'll we'll + + + align:start position:0% +kind of grapples with and we'll we'll +watch that and we can have a similar + + align:start position:0% +watch that and we can have a similar + + + align:start position:0% +watch that and we can have a similar +session to talk about it uh next week + + align:start position:0% +session to talk about it uh next week + + + align:start position:0% +session to talk about it uh next week +I'll make sure we all have to + + align:start position:0% +I'll make sure we all have to + + + align:start position:0% +I'll make sure we all have to +details in email but yeah I mean + + align:start position:0% +details in email but yeah I mean + + + align:start position:0% +details in email but yeah I mean +again it's it's one of these things + + align:start position:0% +again it's it's one of these things + + + align:start position:0% +again it's it's one of these things +where people knew better at the time + + align:start position:0% +where people knew better at the time + + + align:start position:0% +where people knew better at the time +they didn't know as much as we know now + + align:start position:0% +they didn't know as much as we know now + + + align:start position:0% +they didn't know as much as we know now +but the the kind of cavalierness or even + + align:start position:0% +but the the kind of cavalierness or even + + + align:start position:0% +but the the kind of cavalierness or even +sometimes callousness I think with which + + align:start position:0% +sometimes callousness I think with which + + + align:start position:0% +sometimes callousness I think with which +some legitimately dangerous materials + + align:start position:0% +some legitimately dangerous materials + + + align:start position:0% +some legitimately dangerous materials +were handled in the 40s and 50s uh it's + + align:start position:0% +were handled in the 40s and 50s uh it's + + + align:start position:0% +were handled in the 40s and 50s uh it's +still um astonishing and it's not + + align:start position:0% +still um astonishing and it's not + + + align:start position:0% +still um astonishing and it's not +good to say the only place that was + + align:start position:0% +good to say the only place that was + + + align:start position:0% +good to say the only place that was +worse was was some parts of the Soviet + + align:start position:0% +worse was was some parts of the Soviet + + + align:start position:0% +worse was was some parts of the Soviet +Union I mean if that's a competition + + align:start position:0% +Union I mean if that's a competition + + + align:start position:0% +Union I mean if that's a competition +that's not great in terms of just the + + align:start position:0% +that's not great in terms of just the + + + align:start position:0% +that's not great in terms of just the +Cavalier uh disregard for local + + align:start position:0% +Cavalier uh disregard for local + + + align:start position:0% +Cavalier uh disregard for local +populations + + align:start position:0% +populations + + + align:start position:0% +populations +um that sort of the only place more + + align:start position:0% +um that sort of the only place more + + + align:start position:0% +um that sort of the only place more +poisonous from nuclear efforts than + + align:start position:0% +poisonous from nuclear efforts than + + + align:start position:0% +poisonous from nuclear efforts than +Hanford is the corresponding site in uh + + align:start position:0% +Hanford is the corresponding site in uh + + + align:start position:0% +Hanford is the corresponding site in uh +I forgot which one it is Tiffany by + + align:start position:0% +I forgot which one it is Tiffany by + + + align:start position:0% +I forgot which one it is Tiffany by +remember but one of these sites within + + align:start position:0% +remember but one of these sites within + + + align:start position:0% +remember but one of these sites within +the former Soviet Union with it also + + align:start position:0% +the former Soviet Union with it also + + + align:start position:0% +the former Soviet Union with it also +been doing enormously large-scale + + align:start position:0% +been doing enormously large-scale + + + align:start position:0% +been doing enormously large-scale +plutonium production so I think things + + align:start position:0% +plutonium production so I think things + + + align:start position:0% +plutonium production so I think things +like that + + align:start position:0% + + + + align:start position:0% + +right in fact my understanding is that + + align:start position:0% +right in fact my understanding is that + + + align:start position:0% +right in fact my understanding is that +he was exposed because he threw himself + + align:start position:0% +he was exposed because he threw himself + + + align:start position:0% +he was exposed because he threw himself +on top of it to knock him apart he + + align:start position:0% +on top of it to knock him apart he + + + align:start position:0% +on top of it to knock him apart he +basically threw like you like a soldier + + align:start position:0% +basically threw like you like a soldier + + + align:start position:0% +basically threw like you like a soldier +went on a grenade or something like that + + align:start position:0% +went on a grenade or something like that + + + align:start position:0% +went on a grenade or something like that +to save you know comrades that he he + + align:start position:0% +to save you know comrades that he he + + + align:start position:0% +to save you know comrades that he he +really threw his body on these now you + + align:start position:0% +really threw his body on these now you + + + align:start position:0% +really threw his body on these now you +know now joined uh um critical mass so + + align:start position:0% +know now joined uh um critical mass so + + + align:start position:0% +know now joined uh um critical mass so +he was so my mentor that I mentioned uh + + align:start position:0% +he was so my mentor that I mentioned uh + + + align:start position:0% +he was so my mentor that I mentioned uh +who had served as a young kid in + + align:start position:0% +who had served as a young kid in + + + align:start position:0% +who had served as a young kid in +Manhattan Project + + align:start position:0% +Manhattan Project + + + align:start position:0% +Manhattan Project +so the rest of his life my teacher wore + + align:start position:0% +so the rest of his life my teacher wore + + + align:start position:0% +so the rest of his life my teacher wore +sloten's belt buckle they've been + + align:start position:0% +sloten's belt buckle they've been + + + align:start position:0% +sloten's belt buckle they've been +buddies they were like total young kids + + align:start position:0% +buddies they were like total young kids + + + align:start position:0% +buddies they were like total young kids +together and uh at Los Alamos + + align:start position:0% +together and uh at Los Alamos + + + align:start position:0% +together and uh at Los Alamos +and slow so the accident happened soon + + align:start position:0% +and slow so the accident happened soon + + + align:start position:0% +and slow so the accident happened soon +after the war like weeks they were still + + align:start position:0% +after the war like weeks they were still + + + align:start position:0% +after the war like weeks they were still +working Full Tilt uh and and Leonard + + align:start position:0% +working Full Tilt uh and and Leonard + + + align:start position:0% +working Full Tilt uh and and Leonard +reason was still there my teacher and so + + align:start position:0% +reason was still there my teacher and so + + + align:start position:0% +reason was still there my teacher and so +uh slogan died within days of the + + align:start position:0% +uh slogan died within days of the + + + align:start position:0% +uh slogan died within days of the +exposure it was a very very intense + + align:start position:0% +exposure it was a very very intense + + + align:start position:0% +exposure it was a very very intense +exposure right in his in his gut which + + align:start position:0% +exposure right in his in his gut which + + + align:start position:0% +exposure right in his in his gut which +is not a good place to absorb lots of + + align:start position:0% +is not a good place to absorb lots of + + + align:start position:0% +is not a good place to absorb lots of +these things uh and so Leonard kept his + + align:start position:0% +these things uh and so Leonard kept his + + + align:start position:0% +these things uh and so Leonard kept his +uh got his belt buckle for the rest of + + align:start position:0% +uh got his belt buckle for the rest of + + + align:start position:0% +uh got his belt buckle for the rest of +his life that I only know the name + + align:start position:0% +his life that I only know the name + + + align:start position:0% +his life that I only know the name +because I heard about it when I was + + align:start position:0% +because I heard about it when I was + + + align:start position:0% +because I heard about it when I was +starting when I was about 18. but but + + align:start position:0% +starting when I was about 18. but but + + + align:start position:0% +starting when I was about 18. but but +but you're right house it's an amazing + + align:start position:0% +but you're right house it's an amazing + + + align:start position:0% +but you're right house it's an amazing +story about talk about Cavalier anything + + align:start position:0% +story about talk about Cavalier anything + + + align:start position:0% +story about talk about Cavalier anything +that like a kind of just shop level + + align:start position:0% +that like a kind of just shop level + + + align:start position:0% +that like a kind of just shop level +safety standards let alone + + align:start position:0% +safety standards let alone + + + align:start position:0% +safety standards let alone +you know treat these stuff treat these + + align:start position:0% +you know treat these stuff treat these + + + align:start position:0% +you know treat these stuff treat these +things with some level of kind of um awe + + align:start position:0% +things with some level of kind of um awe + + + align:start position:0% +things with some level of kind of um awe +and respect because of the forces of + + align:start position:0% +and respect because of the forces of + + + align:start position:0% +and respect because of the forces of +nature but just like don't prop stuff + + align:start position:0% +nature but just like don't prop stuff + + + align:start position:0% +nature but just like don't prop stuff +over with a screwdriver like come on you + + align:start position:0% +over with a screwdriver like come on you + + + align:start position:0% +over with a screwdriver like come on you +know just basic level of machine shop + + align:start position:0% +know just basic level of machine shop + + + align:start position:0% +know just basic level of machine shop +let alone uh Safe Handling of of nuclear + + align:start position:0% +let alone uh Safe Handling of of nuclear + + + align:start position:0% +let alone uh Safe Handling of of nuclear +materials so that does great that's + + align:start position:0% +materials so that does great that's + + + align:start position:0% +materials so that does great that's +another great example + + align:start position:0% +another great example + + + align:start position:0% +another great example +good + + align:start position:0% +good + + + align:start position:0% +good +any other questions these are great + + align:start position:0% +any other questions these are great + + + align:start position:0% +any other questions these are great +topics great questions + + align:start position:0% + + + + align:start position:0% + +no it was it was definitely after it's a + + align:start position:0% +no it was it was definitely after it's a + + + align:start position:0% +no it was it was definitely after it's a +good question because I don't know the + + align:start position:0% +good question because I don't know the + + + align:start position:0% +good question because I don't know the +fine to tell some of the Tas might + + align:start position:0% +fine to tell some of the Tas might + + + align:start position:0% +fine to tell some of the Tas might +remember better from recent readings the + + align:start position:0% +remember better from recent readings the + + + align:start position:0% +remember better from recent readings the +rough story goes like this so there was + + align:start position:0% +rough story goes like this so there was + + + align:start position:0% +rough story goes like this so there was +um the soon after the end of the war and + + align:start position:0% +um the soon after the end of the war and + + + align:start position:0% +um the soon after the end of the war and +I guess I'll talk about this briefly on + + align:start position:0% +I guess I'll talk about this briefly on + + + align:start position:0% +I guess I'll talk about this briefly on +Wednesday + + align:start position:0% +Wednesday + + + align:start position:0% +Wednesday +um by I was signed into law I think + + align:start position:0% +um by I was signed into law I think + + + align:start position:0% +um by I was signed into law I think +August of 46 so + + align:start position:0% +August of 46 so + + + align:start position:0% +August of 46 so +roughly a year after after Japanese + + align:start position:0% +roughly a year after after Japanese + + + align:start position:0% +roughly a year after after Japanese +surrender the U.S passed the atomic + + align:start position:0% +surrender the U.S passed the atomic + + + align:start position:0% +surrender the U.S passed the atomic +energy Act uh and that was a sprawling + + align:start position:0% +energy Act uh and that was a sprawling + + + align:start position:0% +energy Act uh and that was a sprawling +piece of legislation that established + + align:start position:0% +piece of legislation that established + + + align:start position:0% +piece of legislation that established +the successor agency to the wartime + + align:start position:0% +the successor agency to the wartime + + + align:start position:0% +the successor agency to the wartime +Manhattan Project nominally civilian it + + align:start position:0% +Manhattan Project nominally civilian it + + + align:start position:0% +Manhattan Project nominally civilian it +it created what was called the atomic + + align:start position:0% +it created what was called the atomic + + + align:start position:0% +it created what was called the atomic +energy commission the aec + + align:start position:0% +energy commission the aec + + + align:start position:0% +energy commission the aec +um + + align:start position:0% +um + + + align:start position:0% +um +uh thank you and um and uh but it also + + align:start position:0% +uh thank you and um and uh but it also + + + align:start position:0% +uh thank you and um and uh but it also +made all things related to nuclear + + align:start position:0% +made all things related to nuclear + + + align:start position:0% +made all things related to nuclear +power born secret and and subject only + + align:start position:0% +power born secret and and subject only + + + align:start position:0% +power born secret and and subject only +basically to military or official + + align:start position:0% +basically to military or official + + + align:start position:0% +basically to military or official +government control in the U.S so it had + + align:start position:0% +government control in the U.S so it had + + + align:start position:0% +government control in the U.S so it had +a a kind of unintended consequence of + + align:start position:0% +a a kind of unintended consequence of + + + align:start position:0% +a a kind of unintended consequence of +hugely stifling a kind of private sector + + align:start position:0% +hugely stifling a kind of private sector + + + align:start position:0% +hugely stifling a kind of private sector +development of energy of of energy + + align:start position:0% +development of energy of of energy + + + align:start position:0% +development of energy of of energy +generation of reactors + + align:start position:0% +generation of reactors + + + align:start position:0% +generation of reactors +that was then uh amended a big Amendment + + align:start position:0% +that was then uh amended a big Amendment + + + align:start position:0% +that was then uh amended a big Amendment +to the atomic energy act and I think 53 + + align:start position:0% +to the atomic energy act and I think 53 + + + align:start position:0% +to the atomic energy act and I think 53 +again others on the column I remember I + + align:start position:0% +again others on the column I remember I + + + align:start position:0% +again others on the column I remember I +think it's 1953. + + align:start position:0% +think it's 1953. + + + align:start position:0% +think it's 1953. +which which began to make certain kinds + + align:start position:0% +which which began to make certain kinds + + + align:start position:0% +which which began to make certain kinds +of we might call it private private + + align:start position:0% +of we might call it private private + + + align:start position:0% +of we might call it private private +Public Partnerships a kind of limited + + align:start position:0% +Public Partnerships a kind of limited + + + align:start position:0% +Public Partnerships a kind of limited +entrepreneurship possible in the power + + align:start position:0% +entrepreneurship possible in the power + + + align:start position:0% +entrepreneurship possible in the power +generation Market it still wasn't a free + + align:start position:0% +generation Market it still wasn't a free + + + align:start position:0% +generation Market it still wasn't a free +market but it was no longer a felony to + + align:start position:0% +market but it was no longer a felony to + + + align:start position:0% +market but it was no longer a felony to +to share certain kinds of you know + + align:start position:0% +to share certain kinds of you know + + + align:start position:0% +to share certain kinds of you know +documents of otherwise innocuous + + align:start position:0% +documents of otherwise innocuous + + + align:start position:0% +documents of otherwise innocuous +information seemingly innocuous not with + + align:start position:0% +information seemingly innocuous not with + + + align:start position:0% +information seemingly innocuous not with +no no kind of direct weapons potential + + align:start position:0% +no no kind of direct weapons potential + + + align:start position:0% +no no kind of direct weapons potential +so it starts you start getting a more + + align:start position:0% +so it starts you start getting a more + + + align:start position:0% +so it starts you start getting a more +active + + align:start position:0% +active + + + align:start position:0% +active +um kind of uh + + align:start position:0% +um kind of uh + + + align:start position:0% +um kind of uh +what's the word active um + + align:start position:0% + + + + align:start position:0% + +sorry uh you know trying to build up a + + align:start position:0% +sorry uh you know trying to build up a + + + align:start position:0% +sorry uh you know trying to build up a +kind of uh working quasi-market private + + align:start position:0% +kind of uh working quasi-market private + + + align:start position:0% +kind of uh working quasi-market private +public partnership with major industrial + + align:start position:0% +public partnership with major industrial + + + align:start position:0% +public partnership with major industrial +contractors like General Electric like + + align:start position:0% +contractors like General Electric like + + + align:start position:0% +contractors like General Electric like +Westinghouse uh building + + align:start position:0% +Westinghouse uh building + + + align:start position:0% +Westinghouse uh building +um uh commercial react power reactors by + + align:start position:0% +um uh commercial react power reactors by + + + align:start position:0% +um uh commercial react power reactors by +the mid to late 50s it doesn't take off + + align:start position:0% +the mid to late 50s it doesn't take off + + + align:start position:0% +the mid to late 50s it doesn't take off +the way other new technologies you know + + align:start position:0% +the way other new technologies you know + + + align:start position:0% +the way other new technologies you know +have done in history because it still + + align:start position:0% +have done in history because it still + + + align:start position:0% +have done in history because it still +has a lot of um a lingering period of + + align:start position:0% +has a lot of um a lingering period of + + + align:start position:0% +has a lot of um a lingering period of +not clear quite how to get this right uh + + align:start position:0% +not clear quite how to get this right uh + + + align:start position:0% +not clear quite how to get this right uh +so so over the course of 50s there were + + align:start position:0% +so so over the course of 50s there were + + + align:start position:0% +so so over the course of 50s there were +power reactors actually coming online uh + + align:start position:0% +power reactors actually coming online uh + + + align:start position:0% +power reactors actually coming online uh +shipping Port News I think was the first + + align:start position:0% +shipping Port News I think was the first + + + align:start position:0% +shipping Port News I think was the first +or among the most famous somewhere in + + align:start position:0% +or among the most famous somewhere in + + + align:start position:0% +or among the most famous somewhere in +Pennsylvania for example + + align:start position:0% +Pennsylvania for example + + + align:start position:0% +Pennsylvania for example +um so they didn't become ubiquitous + + align:start position:0% +um so they didn't become ubiquitous + + + align:start position:0% +um so they didn't become ubiquitous +right away but they were coming into + + align:start position:0% +right away but they were coming into + + + align:start position:0% +right away but they were coming into +genuine civilian use you know in the + + align:start position:0% +genuine civilian use you know in the + + + align:start position:0% +genuine civilian use you know in the +outs groups of populated areas uh by the + + align:start position:0% +outs groups of populated areas uh by the + + + align:start position:0% +outs groups of populated areas uh by the +end of the 1950s for the submarines and + + align:start position:0% +end of the 1950s for the submarines and + + + align:start position:0% +end of the 1950s for the submarines and +things that was again I think a mid to + + align:start position:0% +things that was again I think a mid to + + + align:start position:0% +things that was again I think a mid to +late 50s development uh Admiral rickover + + align:start position:0% +late 50s development uh Admiral rickover + + + align:start position:0% +late 50s development uh Admiral rickover +um + + align:start position:0% +um + + + align:start position:0% +um +Hyman rickover was I think the main + + align:start position:0% +Hyman rickover was I think the main + + + align:start position:0% +Hyman rickover was I think the main +moving force behind trying to um what + + align:start position:0% +moving force behind trying to um what + + + align:start position:0% +moving force behind trying to um what +was often called modernize the naval + + align:start position:0% +was often called modernize the naval + + + align:start position:0% +was often called modernize the naval +fleet including making uh reactor driven + + align:start position:0% +fleet including making uh reactor driven + + + align:start position:0% +fleet including making uh reactor driven +submarines that could stay underwater + + align:start position:0% +submarines that could stay underwater + + + align:start position:0% +submarines that could stay underwater +much longer for example let alone armed + + align:start position:0% +much longer for example let alone armed + + + align:start position:0% +much longer for example let alone armed +with nuclear weapons but just could + + align:start position:0% +with nuclear weapons but just could + + + align:start position:0% +with nuclear weapons but just could +could the could the power come largely + + align:start position:0% +could the could the power come largely + + + align:start position:0% +could the could the power come largely +from nuclear reactors on board uh for + + align:start position:0% +from nuclear reactors on board uh for + + + align:start position:0% +from nuclear reactors on board uh for +kind of strategic reasons wouldn't have + + align:start position:0% +kind of strategic reasons wouldn't have + + + align:start position:0% +kind of strategic reasons wouldn't have +to surface as frequently or things like + + align:start position:0% +to surface as frequently or things like + + + align:start position:0% +to surface as frequently or things like +that so again I think those are being + + align:start position:0% +that so again I think those are being + + + align:start position:0% +that so again I think those are being +developed largely uh in uh within the + + align:start position:0% +developed largely uh in uh within the + + + align:start position:0% +developed largely uh in uh within the +military so it didn't have the same kind + + align:start position:0% +military so it didn't have the same kind + + + align:start position:0% +military so it didn't have the same kind +of public private same level uh of of + + align:start position:0% +of public private same level uh of of + + + align:start position:0% +of public private same level uh of of +um friction but those were being again I + + align:start position:0% +um friction but those were being again I + + + align:start position:0% +um friction but those were being again I +don't know when the first one came into + + align:start position:0% +don't know when the first one came into + + + align:start position:0% +don't know when the first one came into +service probably by the early 60s at the + + align:start position:0% +service probably by the early 60s at the + + + align:start position:0% +service probably by the early 60s at the +latest certainly under active + + align:start position:0% +latest certainly under active + + + align:start position:0% +latest certainly under active +development and testing by the 50s late + + align:start position:0% +development and testing by the 50s late + + + align:start position:0% +development and testing by the 50s late +50s + + align:start position:0% +50s + + + align:start position:0% +50s +um and as we'll see in in Wednesday's + + align:start position:0% +um and as we'll see in in Wednesday's + + + align:start position:0% +um and as we'll see in in Wednesday's +class this also begins to coincide with + + align:start position:0% +class this also begins to coincide with + + + align:start position:0% +class this also begins to coincide with +growing concerns about + + align:start position:0% +growing concerns about + + + align:start position:0% +growing concerns about +um + + align:start position:0% +um + + + align:start position:0% +um +about Fallout so about above ground + + align:start position:0% +about Fallout so about above ground + + + align:start position:0% +about Fallout so about above ground +nuclear weapons testing concerns about + + align:start position:0% +nuclear weapons testing concerns about + + + align:start position:0% +nuclear weapons testing concerns about +safety or otherwise of nuclear power + + align:start position:0% +safety or otherwise of nuclear power + + + align:start position:0% +safety or otherwise of nuclear power +generation uh was not the first topic of + + align:start position:0% +generation uh was not the first topic of + + + align:start position:0% +generation uh was not the first topic of +real kind of public consternation or or + + align:start position:0% +real kind of public consternation or or + + + align:start position:0% +real kind of public consternation or or +debate it really was about the Fallout + + align:start position:0% +debate it really was about the Fallout + + + align:start position:0% +debate it really was about the Fallout +coming back to questions that Stephen + + align:start position:0% +coming back to questions that Stephen + + + align:start position:0% +coming back to questions that Stephen +was asking earlier what happens when you + + align:start position:0% +was asking earlier what happens when you + + + align:start position:0% +was asking earlier what happens when you +blow a bunch of things of these things + + align:start position:0% +blow a bunch of things of these things + + + align:start position:0% +blow a bunch of things of these things +up in the atmosphere and stuff comes + + align:start position:0% +up in the atmosphere and stuff comes + + + align:start position:0% +up in the atmosphere and stuff comes +down uh and so we will hear a bit about + + align:start position:0% +down uh and so we will hear a bit about + + + align:start position:0% +down uh and so we will hear a bit about +that in Wednesday's class so so the + + align:start position:0% +that in Wednesday's class so so the + + + align:start position:0% +that in Wednesday's class so so the +first public efforts uh first widespread + + align:start position:0% +first public efforts uh first widespread + + + align:start position:0% +first public efforts uh first widespread +kind of anti-nuclear mobilizations + + align:start position:0% +kind of anti-nuclear mobilizations + + + align:start position:0% +kind of anti-nuclear mobilizations +we're really also starting by the late + + align:start position:0% +we're really also starting by the late + + + align:start position:0% +we're really also starting by the late +50s uh and they had these kind of fits + + align:start position:0% +50s uh and they had these kind of fits + + + align:start position:0% +50s uh and they had these kind of fits +and starts of temporarily successful + + align:start position:0% +and starts of temporarily successful + + + align:start position:0% +and starts of temporarily successful +treaties that would stop and then they'd + + align:start position:0% +treaties that would stop and then they'd + + + align:start position:0% +treaties that would stop and then they'd +go back and so so a lot of the kind of + + align:start position:0% +go back and so so a lot of the kind of + + + align:start position:0% +go back and so so a lot of the kind of +official um treaty space as well as more + + align:start position:0% +official um treaty space as well as more + + + align:start position:0% +official um treaty space as well as more +informal political organizing against + + align:start position:0% +informal political organizing against + + + align:start position:0% +informal political organizing against +certain aspects of nuclear uh + + align:start position:0% +certain aspects of nuclear uh + + + align:start position:0% +certain aspects of nuclear uh +Technologies now it's also growing over + + align:start position:0% +Technologies now it's also growing over + + + align:start position:0% +Technologies now it's also growing over +the course of 50s into the 1960s they've + + align:start position:0% +the course of 50s into the 1960s they've + + + align:start position:0% +the course of 50s into the 1960s they've +kind of grown up together + + align:start position:0% +kind of grown up together + + + align:start position:0% +kind of grown up together +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +there were efforts by the way throughout + + align:start position:0% +there were efforts by the way throughout + + + align:start position:0% +there were efforts by the way throughout +the early and mid 50s to try to Modern + + align:start position:0% +the early and mid 50s to try to Modern + + + align:start position:0% +the early and mid 50s to try to Modern +so-called modernize the weapons side so + + align:start position:0% +so-called modernize the weapons side so + + + align:start position:0% +so-called modernize the weapons side so +to shrink down so both to make + + align:start position:0% +to shrink down so both to make + + + align:start position:0% +to shrink down so both to make +enormously humongous hydrogen weapons + + align:start position:0% +enormously humongous hydrogen weapons + + + align:start position:0% +enormously humongous hydrogen weapons +that were thousands as many thousands of + + align:start position:0% +that were thousands as many thousands of + + + align:start position:0% +that were thousands as many thousands of +times more powerful than the fission + + align:start position:0% +times more powerful than the fission + + + align:start position:0% +times more powerful than the fission +bombs of the war of the second world war + + align:start position:0% +bombs of the war of the second world war + + + align:start position:0% +bombs of the war of the second world war +but also to miniaturize them so that + + align:start position:0% +but also to miniaturize them so that + + + align:start position:0% +but also to miniaturize them so that +they would be more likely to be useful + + align:start position:0% +they would be more likely to be useful + + + align:start position:0% +they would be more likely to be useful +tactically not strategically + + align:start position:0% +tactically not strategically + + + align:start position:0% +tactically not strategically +strategically was the was the lingo + + align:start position:0% +strategically was the was the lingo + + + align:start position:0% +strategically was the was the lingo +Lucas you might know from talking with + + align:start position:0% +Lucas you might know from talking with + + + align:start position:0% +Lucas you might know from talking with +the folks in security studies strategic + + align:start position:0% +the folks in security studies strategic + + + align:start position:0% +the folks in security studies strategic +is the idea that is it based roughly + + align:start position:0% +is the idea that is it based roughly + + + align:start position:0% +is the idea that is it based roughly +speaking kind of symbolic would would it + + align:start position:0% +speaking kind of symbolic would would it + + + align:start position:0% +speaking kind of symbolic would would it +be impossible for any enemy to attack + + align:start position:0% +be impossible for any enemy to attack + + + align:start position:0% +be impossible for any enemy to attack +you because it could they be assured of + + align:start position:0% +you because it could they be assured of + + + align:start position:0% +you because it could they be assured of +immediate Annihilation because you have + + align:start position:0% +immediate Annihilation because you have + + + align:start position:0% +immediate Annihilation because you have +City leveling Megaton bombs so that was + + align:start position:0% +City leveling Megaton bombs so that was + + + align:start position:0% +City leveling Megaton bombs so that was +seen as strategic to have a kind of + + align:start position:0% +seen as strategic to have a kind of + + + align:start position:0% +seen as strategic to have a kind of +unsteady balance of power because no one + + align:start position:0% +unsteady balance of power because no one + + + align:start position:0% +unsteady balance of power because no one +would be dumb enough to trigger those + + align:start position:0% +would be dumb enough to trigger those + + + align:start position:0% +would be dumb enough to trigger those +enormous things for use then there's + + align:start position:0% +enormous things for use then there's + + + align:start position:0% +enormous things for use then there's +tactical weapons that people might + + align:start position:0% +tactical weapons that people might + + + align:start position:0% +tactical weapons that people might +actually plausibly use on a battlefield + + align:start position:0% +actually plausibly use on a battlefield + + + align:start position:0% +actually plausibly use on a battlefield +without the kind of you know high level + + align:start position:0% +without the kind of you know high level + + + align:start position:0% +without the kind of you know high level +uh uh hand ringing about oh my goodness + + align:start position:0% +uh uh hand ringing about oh my goodness + + + align:start position:0% +uh uh hand ringing about oh my goodness +it's Mega tonnage so people were making + + align:start position:0% +it's Mega tonnage so people were making + + + align:start position:0% +it's Mega tonnage so people were making +so-called Davy Crockett basically like + + align:start position:0% +so-called Davy Crockett basically like + + + align:start position:0% +so-called Davy Crockett basically like +shoulder-fired bazooka-sized nuclear + + align:start position:0% +shoulder-fired bazooka-sized nuclear + + + align:start position:0% +shoulder-fired bazooka-sized nuclear +weapons which were actually developed + + align:start position:0% +weapons which were actually developed + + + align:start position:0% +weapons which were actually developed +and deployed in the field technically + + align:start position:0% +and deployed in the field technically + + + align:start position:0% +and deployed in the field technically +never used but but certainly tested so + + align:start position:0% +never used but but certainly tested so + + + align:start position:0% +never used but but certainly tested so +those are both a miniaturization to make + + align:start position:0% +those are both a miniaturization to make + + + align:start position:0% +those are both a miniaturization to make +these things more ubiquitous in certain + + align:start position:0% +these things more ubiquitous in certain + + + align:start position:0% +these things more ubiquitous in certain +kinds of of uh tactical U.S military + + align:start position:0% +kinds of of uh tactical U.S military + + + align:start position:0% +kinds of of uh tactical U.S military +planning not only us but including West + + align:start position:0% +planning not only us but including West + + + align:start position:0% +planning not only us but including West +and then the kind of enormity the kind + + align:start position:0% +and then the kind of enormity the kind + + + align:start position:0% +and then the kind of enormity the kind +of monsters that will that that we'll + + align:start position:0% +of monsters that will that that we'll + + + align:start position:0% +of monsters that will that that we'll +talk a bit about uh in next class that + + align:start position:0% +talk a bit about uh in next class that + + + align:start position:0% +talk a bit about uh in next class that +were really um you know just made the + + align:start position:0% +were really um you know just made the + + + align:start position:0% +were really um you know just made the +the Hiroshima Nagasaki weapons look look + + align:start position:0% +the Hiroshima Nagasaki weapons look look + + + align:start position:0% +the Hiroshima Nagasaki weapons look look +small it was both these kind of fronts + + align:start position:0% +small it was both these kind of fronts + + + align:start position:0% +small it was both these kind of fronts +of development on the on the more + + align:start position:0% +of development on the on the more + + + align:start position:0% +of development on the on the more +weapons technology sides those were + + align:start position:0% +weapons technology sides those were + + + align:start position:0% +weapons technology sides those were +actively under under development + + align:start position:0% +actively under under development + + + align:start position:0% +actively under under development +throughout the 50s + + align:start position:0% + + + + align:start position:0% + +yeah no that absolutely right and again + + align:start position:0% +yeah no that absolutely right and again + + + align:start position:0% +yeah no that absolutely right and again +we think back to that and yet that was + + align:start position:0% +we think back to that and yet that was + + + align:start position:0% +we think back to that and yet that was +not a sufficient to end the program much + + align:start position:0% +not a sufficient to end the program much + + + align:start position:0% +not a sufficient to end the program much +as the fact that poison gas first + + align:start position:0% +as the fact that poison gas first + + + align:start position:0% +as the fact that poison gas first +deployed in the first world war also you + + align:start position:0% +deployed in the first world war also you + + + align:start position:0% +deployed in the first world war also you +know the winds would change and you + + align:start position:0% +know the winds would change and you + + + align:start position:0% +know the winds would change and you +would not infrequently wound up casting + + align:start position:0% +would not infrequently wound up casting + + + align:start position:0% +would not infrequently wound up casting +your own troops inadvertently so the the + + align:start position:0% +your own troops inadvertently so the the + + + align:start position:0% +your own troops inadvertently so the the +the competing + + align:start position:0% +the competing + + + align:start position:0% +the competing +calculations about what's going to be a + + align:start position:0% +calculations about what's going to be a + + + align:start position:0% +calculations about what's going to be a +worthwhile device to to pursue uh + + align:start position:0% +worthwhile device to to pursue uh + + + align:start position:0% +worthwhile device to to pursue uh +unfortunately that was not unique either + + align:start position:0% +unfortunately that was not unique either + + + align:start position:0% +unfortunately that was not unique either +yeah + + align:start position:0% + + + + align:start position:0% + +yes it's an idea that that so it comes + + align:start position:0% +yes it's an idea that that so it comes + + + align:start position:0% +yes it's an idea that that so it comes +and goes uh as as many of you may know + + align:start position:0% +and goes uh as as many of you may know + + + align:start position:0% +and goes uh as as many of you may know +where the US is for the time being uh is + + align:start position:0% +where the US is for the time being uh is + + + align:start position:0% +where the US is for the time being uh is +still subject to a um a Limited Test Ban + + align:start position:0% +still subject to a um a Limited Test Ban + + + align:start position:0% +still subject to a um a Limited Test Ban +Treaty which suggests that there can be + + align:start position:0% +Treaty which suggests that there can be + + + align:start position:0% +Treaty which suggests that there can be +no + + align:start position:0% +no + + + align:start position:0% +no +um + + align:start position:0% +um + + + align:start position:0% +um +I'm getting the wrong trade actually + + align:start position:0% +I'm getting the wrong trade actually + + + align:start position:0% +I'm getting the wrong trade actually +more recent treaty there was a a more + + align:start position:0% +more recent treaty there was a a more + + + align:start position:0% +more recent treaty there was a a more +complete test Bantry the U.S signed + + align:start position:0% +complete test Bantry the U.S signed + + + align:start position:0% +complete test Bantry the U.S signed +starting in 1992 was one of the last + + align:start position:0% +starting in 1992 was one of the last + + + align:start position:0% +starting in 1992 was one of the last +things that President George H.W bush + + align:start position:0% +things that President George H.W bush + + + align:start position:0% +things that President George H.W bush +signed uh before uh the before the + + align:start position:0% +signed uh before uh the before the + + + align:start position:0% +signed uh before uh the before the +Clinton administration + + align:start position:0% +Clinton administration + + + align:start position:0% +Clinton administration +so the U.S presently by our by treaty + + align:start position:0% +so the U.S presently by our by treaty + + + align:start position:0% +so the U.S presently by our by treaty +statute is not allowed to test new + + align:start position:0% +statute is not allowed to test new + + + align:start position:0% +statute is not allowed to test new +nuclear weapon designs and that led to + + align:start position:0% +nuclear weapon designs and that led to + + + align:start position:0% +nuclear weapon designs and that led to +an enormous multi-billion dollar project + + align:start position:0% +an enormous multi-billion dollar project + + + align:start position:0% +an enormous multi-billion dollar project +called stockpile stewardship to so there + + align:start position:0% +called stockpile stewardship to so there + + + align:start position:0% +called stockpile stewardship to so there +was testing allowed non-nuclear tests + + align:start position:0% +was testing allowed non-nuclear tests + + + align:start position:0% +was testing allowed non-nuclear tests +allowed to be performed to to maintain + + align:start position:0% +allowed to be performed to to maintain + + + align:start position:0% +allowed to be performed to to maintain +the Aging stock stockpiles of existing + + align:start position:0% +the Aging stock stockpiles of existing + + + align:start position:0% +the Aging stock stockpiles of existing +weapons epoxies dry out and change you + + align:start position:0% +weapons epoxies dry out and change you + + + align:start position:0% +weapons epoxies dry out and change you +know all the kind of convention + + align:start position:0% +know all the kind of convention + + + align:start position:0% +know all the kind of convention +materials + + align:start position:0% +materials + + + align:start position:0% +materials +um don't have a shelf life of 10 000 + + align:start position:0% +um don't have a shelf life of 10 000 + + + align:start position:0% +um don't have a shelf life of 10 000 +years so stockpile stewardship is meant + + align:start position:0% +years so stockpile stewardship is meant + + + align:start position:0% +years so stockpile stewardship is meant +to enable laboratory style testing for + + align:start position:0% +to enable laboratory style testing for + + + align:start position:0% +to enable laboratory style testing for +materials to maintain the existing + + align:start position:0% +materials to maintain the existing + + + align:start position:0% +materials to maintain the existing +Arsenal not to develop and perfect new + + align:start position:0% +Arsenal not to develop and perfect new + + + align:start position:0% +Arsenal not to develop and perfect new +weapons and so some of these areas get a + + align:start position:0% +weapons and so some of these areas get a + + + align:start position:0% +weapons and so some of these areas get a +little some critics at least say there's + + align:start position:0% +little some critics at least say there's + + + align:start position:0% +little some critics at least say there's +a little gray area some things that some + + align:start position:0% +a little gray area some things that some + + + align:start position:0% +a little gray area some things that some +people will say are being used for + + align:start position:0% +people will say are being used for + + + align:start position:0% +people will say are being used for +stockpiled stewardship might actually + + align:start position:0% +stockpiled stewardship might actually + + + align:start position:0% +stockpiled stewardship might actually +have implications to help with new + + align:start position:0% +have implications to help with new + + + align:start position:0% +have implications to help with new +designs it's again it it's an area where + + align:start position:0% +designs it's again it it's an area where + + + align:start position:0% +designs it's again it it's an area where +there's ongoing um debate and pushback + + align:start position:0% +there's ongoing um debate and pushback + + + align:start position:0% +there's ongoing um debate and pushback +largely uh you know away from Full + + align:start position:0% +largely uh you know away from Full + + + align:start position:0% +largely uh you know away from Full +public view because some of much of it + + align:start position:0% +public view because some of much of it + + + align:start position:0% +public view because some of much of it +Still Remains classified + + align:start position:0% + + + + align:start position:0% + +yeah Amanda I agree that is a chilling + + align:start position:0% +yeah Amanda I agree that is a chilling + + + align:start position:0% +yeah Amanda I agree that is a chilling +part and that that as I said those lists + + align:start position:0% +part and that that as I said those lists + + + align:start position:0% +part and that that as I said those lists +were made in fact they were made I think + + align:start position:0% +were made in fact they were made I think + + + align:start position:0% +were made in fact they were made I think +by the so-called interim committee which + + align:start position:0% +by the so-called interim committee which + + + align:start position:0% +by the so-called interim committee which +included Oppenheimer and a couple other + + align:start position:0% +included Oppenheimer and a couple other + + + align:start position:0% +included Oppenheimer and a couple other +uh physicists as well as the Secretary + + align:start position:0% +uh physicists as well as the Secretary + + + align:start position:0% +uh physicists as well as the Secretary +of War and other military leaders it was + + align:start position:0% +of War and other military leaders it was + + + align:start position:0% +of War and other military leaders it was +a group of maybe a dozen people + + align:start position:0% +a group of maybe a dozen people + + + align:start position:0% +a group of maybe a dozen people +um and so for example there was a + + align:start position:0% +um and so for example there was a + + + align:start position:0% +um and so for example there was a +decision made early on I think by that + + align:start position:0% +decision made early on I think by that + + + align:start position:0% +decision made early on I think by that +group or at least the recommendation + + align:start position:0% +group or at least the recommendation + + + align:start position:0% +group or at least the recommendation +from that group uh not to bomb the city + + align:start position:0% +from that group uh not to bomb the city + + + align:start position:0% +from that group uh not to bomb the city +of Kyoto either by conventional means + + align:start position:0% +of Kyoto either by conventional means + + + align:start position:0% +of Kyoto either by conventional means +let alone by um with the newer weapons + + align:start position:0% +let alone by um with the newer weapons + + + align:start position:0% +let alone by um with the newer weapons +because I was seen as as two kind of + + align:start position:0% +because I was seen as as two kind of + + + align:start position:0% +because I was seen as as two kind of +culturally significant + + align:start position:0% +culturally significant + + + align:start position:0% +culturally significant +um it was you know a kind of Millennium + + align:start position:0% +um it was you know a kind of Millennium + + + align:start position:0% +um it was you know a kind of Millennium +old city of of uh of art culture and and + + align:start position:0% +old city of of uh of art culture and and + + + align:start position:0% +old city of of uh of art culture and and +um and kind of heritage + + align:start position:0% +um and kind of heritage + + + align:start position:0% +um and kind of heritage +and so + + align:start position:0% +and so + + + align:start position:0% +and so +and that and that wasn't a kind of nukes + + align:start position:0% +and that and that wasn't a kind of nukes + + + align:start position:0% +and that and that wasn't a kind of nukes +versus incentives I was like don't + + align:start position:0% +versus incentives I was like don't + + + align:start position:0% +versus incentives I was like don't +please don't bomb that City + + align:start position:0% +please don't bomb that City + + + align:start position:0% +please don't bomb that City +the U.S uh uh committee advising the U.S + + align:start position:0% +the U.S uh uh committee advising the U.S + + + align:start position:0% +the U.S uh uh committee advising the U.S +military on that + + align:start position:0% +military on that + + + align:start position:0% +military on that +I think was it part of that same + + align:start position:0% +I think was it part of that same + + + align:start position:0% +I think was it part of that same +exercise say what cities would be + + align:start position:0% +exercise say what cities would be + + + align:start position:0% +exercise say what cities would be +so-called legitimate targets for use + + align:start position:0% +so-called legitimate targets for use + + + align:start position:0% +so-called legitimate targets for use +with the nuclear weapons versus other + + align:start position:0% +with the nuclear weapons versus other + + + align:start position:0% +with the nuclear weapons versus other +kinds of attack + + align:start position:0% +kinds of attack + + + align:start position:0% +kinds of attack +and I don't know that that means that + + align:start position:0% +and I don't know that that means that + + + align:start position:0% +and I don't know that that means that +they thought the bomb was special I + + align:start position:0% +they thought the bomb was special I + + + align:start position:0% +they thought the bomb was special I +think they thought it was new it is I I + + align:start position:0% +think they thought it was new it is I I + + + align:start position:0% +think they thought it was new it is I I +think that was the idea of like what for + + align:start position:0% +think that was the idea of like what for + + + align:start position:0% +think that was the idea of like what for +any new element of the in the collection + + align:start position:0% +any new element of the in the collection + + + align:start position:0% +any new element of the in the collection +so to speak you want to you know + + align:start position:0% +so to speak you want to you know + + + align:start position:0% +so to speak you want to you know +understand it's it's parameters its + + align:start position:0% +understand it's it's parameters its + + + align:start position:0% +understand it's it's parameters its +characteristics so I don't know that + + align:start position:0% +characteristics so I don't know that + + + align:start position:0% +characteristics so I don't know that +they that they thought it was somehow in + + align:start position:0% +they that they thought it was somehow in + + + align:start position:0% +they that they thought it was somehow in +a category unto itself I think my sense + + align:start position:0% +a category unto itself I think my sense + + + align:start position:0% +a category unto itself I think my sense +of that is that it's it's a new thing we + + align:start position:0% +of that is that it's it's a new thing we + + + align:start position:0% +of that is that it's it's a new thing we +want to learn about it because we intend + + align:start position:0% +want to learn about it because we intend + + + align:start position:0% +want to learn about it because we intend +to use it a lot more at least we have we + + align:start position:0% +to use it a lot more at least we have we + + + align:start position:0% +to use it a lot more at least we have we +have the option open that this will + + align:start position:0% +have the option open that this will + + + align:start position:0% +have the option open that this will +become a more a more common element of + + align:start position:0% +become a more a more common element of + + + align:start position:0% +become a more a more common element of +the of the Arsenal we'll talk a bit + + align:start position:0% +the of the Arsenal we'll talk a bit + + + align:start position:0% +the of the Arsenal we'll talk a bit +about that actually again on Wednesday + + align:start position:0% +about that actually again on Wednesday + + + align:start position:0% +about that actually again on Wednesday +as well + + align:start position:0% +as well + + + align:start position:0% +as well +that they were even amidst the debates + + align:start position:0% +that they were even amidst the debates + + + align:start position:0% +that they were even amidst the debates +over whether or not the United States + + align:start position:0% +over whether or not the United States + + + align:start position:0% +over whether or not the United States +should pursue a hydrogen weapon so much + + align:start position:0% +should pursue a hydrogen weapon so much + + + align:start position:0% +should pursue a hydrogen weapon so much +more powerful the debate was rarely as + + align:start position:0% +more powerful the debate was rarely as + + + align:start position:0% +more powerful the debate was rarely as +we now know + + align:start position:0% +we now know + + + align:start position:0% +we now know +um nukes or no nukes it was fission + + align:start position:0% +um nukes or no nukes it was fission + + + align:start position:0% +um nukes or no nukes it was fission +versus fusion and one leading Reason Not + + align:start position:0% +versus fusion and one leading Reason Not + + + align:start position:0% +versus fusion and one leading Reason Not +that was before not to pursue Fusion + + align:start position:0% +that was before not to pursue Fusion + + + align:start position:0% +that was before not to pursue Fusion +weapons because it was it would it would + + align:start position:0% +weapons because it was it would it would + + + align:start position:0% +weapons because it was it would it would +slow down the production of lots more + + align:start position:0% +slow down the production of lots more + + + align:start position:0% +slow down the production of lots more +fission weapons because the idea at + + align:start position:0% +fission weapons because the idea at + + + align:start position:0% +fission weapons because the idea at +least among certain influential people + + align:start position:0% +least among certain influential people + + + align:start position:0% +least among certain influential people +including Oppenheimer was that the U.S + + align:start position:0% +including Oppenheimer was that the U.S + + + align:start position:0% +including Oppenheimer was that the U.S +should have hundreds if not thousands of + + align:start position:0% +should have hundreds if not thousands of + + + align:start position:0% +should have hundreds if not thousands of +these things already because at the time + + align:start position:0% +these things already because at the time + + + align:start position:0% +these things already because at the time +they were like very very few in a + + align:start position:0% +they were like very very few in a + + + align:start position:0% +they were like very very few in a +stockpile + + align:start position:0% +stockpile + + + align:start position:0% +stockpile +so so the concern wasn't these things + + align:start position:0% +so so the concern wasn't these things + + + align:start position:0% +so so the concern wasn't these things +were so terrible we should never use + + align:start position:0% +were so terrible we should never use + + + align:start position:0% +were so terrible we should never use +anything in this whole category again + + align:start position:0% +anything in this whole category again + + + align:start position:0% +anything in this whole category again +people have that concern but not not + + align:start position:0% +people have that concern but not not + + + align:start position:0% +people have that concern but not not +these groups behind the behind the fence + + align:start position:0% +these groups behind the behind the fence + + + align:start position:0% +these groups behind the behind the fence +advising we now know their concern was + + align:start position:0% +advising we now know their concern was + + + align:start position:0% +advising we now know their concern was +making these things which might not even + + align:start position:0% +making these things which might not even + + + align:start position:0% +making these things which might not even +work anyway will interrupt too much + + align:start position:0% +work anyway will interrupt too much + + + align:start position:0% +work anyway will interrupt too much +making the things that we now know more + + align:start position:0% +making the things that we now know more + + + align:start position:0% +making the things that we now know more +about because of these things like you + + align:start position:0% +about because of these things like you + + + align:start position:0% +about because of these things like you +know the usage against actual cities and + + align:start position:0% +know the usage against actual cities and + + + align:start position:0% +know the usage against actual cities and +the fact that they were + + align:start position:0% +the fact that they were + + + align:start position:0% +the fact that they were +um + + align:start position:0% +um + + + align:start position:0% +um +not previously destroyed targets you + + align:start position:0% +not previously destroyed targets you + + + align:start position:0% +not previously destroyed targets you +know environment so you could learn a + + align:start position:0% +know environment so you could learn a + + + align:start position:0% +know environment so you could learn a +lot from these post-bombing surveys + + align:start position:0% +lot from these post-bombing surveys + + + align:start position:0% +lot from these post-bombing surveys +I mean it's you know + + align:start position:0% + + + + align:start position:0% + +yeah anyway so that's a bit of a preview + + align:start position:0% +yeah anyway so that's a bit of a preview + + + align:start position:0% +yeah anyway so that's a bit of a preview +we will talk a bit about that in + + align:start position:0% +we will talk a bit about that in + + + align:start position:0% +we will talk a bit about that in +Wednesday's class + + align:start position:0% + + + + align:start position:0% + +yep yep yep no that's uh that's an + + align:start position:0% +yep yep yep no that's uh that's an + + + align:start position:0% +yep yep yep no that's uh that's an +excellent point + + align:start position:0% +excellent point + + + align:start position:0% +excellent point +good I think we'll we'll pause it was a + + align:start position:0% +good I think we'll we'll pause it was a + + + align:start position:0% +good I think we'll we'll pause it was a +really interesting discussion thank you + + align:start position:0% +really interesting discussion thank you + + + align:start position:0% +really interesting discussion thank you +all for for uh taking the time it was an + + align:start position:0% +all for for uh taking the time it was an + + + align:start position:0% +all for for uh taking the time it was an +option during a busy part of the term so + + align:start position:0% +option during a busy part of the term so + + + align:start position:0% +option during a busy part of the term so +I hope it was uh you know interesting + + align:start position:0% +I hope it was uh you know interesting + + + align:start position:0% +I hope it was uh you know interesting +and worthwhile discussion if you have + + align:start position:0% +and worthwhile discussion if you have + + + align:start position:0% +and worthwhile discussion if you have +other questions of course please don't + + align:start position:0% +other questions of course please don't + + + align:start position:0% +other questions of course please don't +hesitate I'll have my regular office + + align:start position:0% +hesitate I'll have my regular office + + + align:start position:0% +hesitate I'll have my regular office +hours on Wednesday morning uh feel free + + align:start position:0% +hours on Wednesday morning uh feel free + + + align:start position:0% +hours on Wednesday morning uh feel free +to email me to make a separate + + align:start position:0% +to email me to make a separate + + + align:start position:0% +to email me to make a separate +appointment of course at any time and + + align:start position:0% +appointment of course at any time and + + + align:start position:0% +appointment of course at any time and +otherwise we'll um we'll meet at our + + align:start position:0% +otherwise we'll um we'll meet at our + + + align:start position:0% +otherwise we'll um we'll meet at our +regular class time on Wednesday so stay + + align:start position:0% +regular class time on Wednesday so stay + + + align:start position:0% +regular class time on Wednesday so stay +well everyone see you soon \ No newline at end of file diff --git a/QstZW4N4SX8.txt b/QstZW4N4SX8.txt new file mode 100644 index 0000000000000000000000000000000000000000..48e5a334da756269fee3e4a9f5c78dc42b54f753 --- /dev/null +++ b/QstZW4N4SX8.txt @@ -0,0 +1,3433 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high quality educational +resources for free. + +To make a donation or to view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +PROFESSOR: --And go on with +lectures 8 to 10. + +First I want to briefly +review what we said + +about measurable functions. + +Again, I encourage you if you +hate this material and you + +think it's only for +mathematicians, + +please let me know. + +I don't know whether it's +appropriate to cover it in + +this class either. + +I think it probably is because +you need to know a little more + +mathematics when you deal with +these Fourier transforms and + +Fourier series. + +When you're dealing with +communication theory, then you + +need to know for signal +processing + +and things like that. + +When you get into learning a +little more, my sense at this + +point is it's much easier to +learn a good deal more than it + +is to learn just a little bit +more, because a little bit + +more you're always faced with +all of these questions of what + +does this really mean. + +It turns out that if you put +just a little bit of measure + +theory into your thinking, it +makes all these problems very + +much simpler. + +So you remember we talked about +what a measurable set + +was last time. + +What a measurable set is, is a +set which you can essentially + +break up into a countable +union of intervals, and + +something which is bounded by +a countble set of intervals + +which have arbitrarily +small measure. + +So you can take all of these +sets of zero measure -- + +countable sets, cantor sets, all +of these things, and you + +can just throw all of those +out from consideration. + +That's what makes measure theory +useful and interesting + +and what simplifies things. + +So we then said that a function +is measurable if each + +of these sets here -- if the +set of times for which a is + +less than or equal to u of t is +less than or equal to b -- + +these things are these +level sets here. + +It's a set of values, t, along +this axis in which the + +function is nailed between any +two of these points here. + +For a function to be measurable, +all of these sets + +in here have to be measurable. + +We haven't given you any +examples of sets which are not + +measurable, and therefore, we +haven't given you any examples + +of functions which are +not measurable. + +It's very, very difficult to +construct such functions, and + +since it's so difficult to +construct them, it's easier to + +just say that all of the +functions we can think of are + +measurable. + +That includes an awful lot more +functions than you ever + +deal with in engineering. + +If you ever make a serious +mistake in your engineering + +work because of thinking that a +function is measurable when + +it's not measurable, I +will give you $1,000. + +I make that promise that you +because I don't think it's + +ever happened in history, I +don't think it ever will + +happen in history, and that's +just how sure I am of it. + +Unless you try to deliberately +make such a mistake in order + +to collect $1,000. + +Of course, that's not fair. + +Then we said the way we define +this approximation to the + +integral, namely, we always +defined it from underneath, + +and therefore, if we started to +take these intervals here + +with epsilon and split them in +half, the thing that happens + +is you always get extra +components put in. + +So that as you make the scaling +finer and finer, what + +happens is the approximation +into the integral gets larger + +and larger. + +Because of that, if you're +dealing with a non-negative + +function, the only two things +that can happen, as you go to + +the limit of finer and finer +scaling, is one, you come to a + +finite limit, and two, you come +to an infinite limit. + +Nothing else can happen. + +You see that's remarkably simple +as mathematics go. + +This is dealing with all of +these functions you can ever + +think of, and those are the +only two things that can + +happen here. + +So then we went on to say that +a function as L1, if it's + +measurable, and if the integral +of its magnitude is + +less than infinity, and +so far we're still + +talking about real functions. + +If u of t is L1, then you can +take the integral of u of t + +and you can split it +up into two things. + +You can split it up into the set +of times over which u of t + +is positive, and the +set of times over + +which u of t is negative. + +The set of times over which u of +t is equal to zero doesn't + +contribute to the integral +at all so you can + +forget about that. + +This is well-defined as the +function is measurable. + +What's now happening is that +if the integral of this + +magnitude is less than infinity, +then both this has + +to be less than infinity, and +this has to be less than + +infinity, which says that so +long as you're dealing with L1 + +functions, you never have to +worry about this nasty + +situation where the negative +part of the function is + +infinite, the positive part of +the function is infinite, and + +therefore, the difference, plus +infinity, minus infinity + +doesn't make any sense at all. + +And instead of having an +integral which is infinite or + +finite, you have a function +which might just be undefined + +completely. + +Well this says that if the +function is L1, you can't ever + +have any problem with integrals +of this sort thing + +being undefined. + +So, and in fact, u of t is +always integral and has a + +finite value in this case. + +Now, we say that a complex +function is measurable if both + +the real part is measurable +and the imaginary part is + +measurable. + +Therefore, you don't have to +worry about complex functions + +as really being any more than +twice as complicated as real + +functions, and conceptually +they aren't any more + +complicated at all because you +just treat them as two + +separate functions, and +everything you know about real + +functions you now know about +complex functions. + +Now, as far as Fourier theory +is concerned -- + +Fourier series, Fourier +integrals, discrete time, + +Fourier transforms -- all of +these things, if u of t is an + +L1 function, then u of t times e +to the 2 pi ft has to be L1, + +and this has to be true for +all possible values of f. + +Why is that? + +Well, it's just that the +absolute value of u of t for + +any given t, is exactly the same +as the absolute value of + +u of t times e to +the 2 pi i ft. + +Namely, this is a quantity whose +magnitude is always 1, + +and therefore, this quantity, +this magnitude is equal to + +this magnitude. + +Therefore, when you integrate +this magnitude, you get the + +same thing as when you integrate +this magnitude. + +So, there's no problem here. + +So what that says, using this +idea, too, of positive and + +negative parts, it says that the +integral of u of t times e + +to the 2 pi i ft dt has to +exist for all real f. + +That covers Fourier series +and Fourier integral. + +We haven't talked about the +Fourier integral yet, but it + +says that just by defining u of +t to be L1, you avoid all + +of these problems of when these +Fourier integrals exist + +and when they don't exist. + +They always exist. + +So let's talk about the Fourier +transform then since + +we're backing into this +slowly anyway. + +What you've learned in probably +two or three classes + +by now is that the Fourier +transform is + +defined in this way. + +Namely, the transform, a +function of frequency, u hat + +of f, we use hats here instead +of capital letters because we + +like to use capital letters +for random variables. + +So that this transform here +is the integral from minus + +infinity to infinity of the +original function, we start + +with u of t times e to the +minus 2 pi ift dt. + +Now, what's the nice +part about this? + +The nice part about this is that +if u of t is L1, then in + +fact this Fourier transform +has to exist everywhere. + +Namely, what you've learned +before in all of these classes + +says essentially that if these +functions are well-behaved + +then these transforms exist. + +What you've learned about +well-behaved is completely + +circular, namely, a function +is well-behaved if the + +transform exists, and the +transform exists if the + +function is well-behaved. + +You have no idea of what kinds +of functions the Fourier + +transform exists and +what kinds of + +functions it doesn't exist. + +There's another thing buried +in here, in this transform + +relationship. + +Namely, the first thing is we're +trying to define the + +transform function of frequency +in terms of the + +function of time. + +Well and good. + +Then we try to define a function +of time in terms of a + +function of frequency. + +What's hidden here is if you +start with u of t, you then + +get a function of frequency, +and this sort of implicitly + +says that you get back +again the same + +thing you started with. + +That, in fact, is the most +ticklish part of all of this. + +So that if we start with an L1 +function u of t, we wind up + +with a Fourier transform, +u hat of f. + +Then u hat of f goes in here. + +We hope we might get back +the sum transform here. + +The nasty thing, and one of the +reasons we're going to get + +away from L1 in just a minute, +is that if a function is L1, + +it's Fourier transform is +not necessarily L1. + +What that means is that you +have to learn all of this + +stuff about L1 functions, and +then as soon as you take the + +Fourier transform, bingo, it's +all gone up in a lot of smoke, + +and you have to start all over +again saying something about + +what properties the transform +might have. + +But anyway, it's nice to start +with because when u of t is + +L1, we know that this function +actually exists. + +It actually exists as +a complex number. + +It exists as a complex +number for every + +possible real f here. + +Namely, there aren't any if, +and's, but's or maybe's here, + +there's nothing like L2 +convergence that we were + +talking about a little +bit before. + +This just exists, period. + +There's something more here, +that if this is L1, this not + +only exists but it's also a +continuous function, and those + +don't prove that. + +If you've taken a course in +analysis and you know what a + +complex function is and you're +quite patient, you can sit + +down and actually show +this yourselves, but + +it's a bit of a pain. + +So for a well-behaved function, +the first integral + +exists for all f, the second +exists for all t, and results + +in the original u of t. + +But then more specifically, +if u of t is L1, the first + +integral exists for all f and +it's a continuous function. + +It's also a bounded function, as +we'll see in a little bit. + +If u hat of f is L1, the second +integral exists for all + +t, and u of t is continuous. + +Therefore, if you assume at +the output at the onset of + +things that both this is +L1 and this is L1, then + +everything is also continuous +and you have a very nice + +theory, which doesn't apply to +too many of the things that + +you're interested in. + +And I'll explain why +in a little bit. + +Anyway, for these well-behaved +functions, we have all of + +these relationships that I'm +sure you've learned in + +whatever linear systems +course you've taken. + +Since you should know all of +these things, I just want to + +briefly talk about them I mean +this linearity idea is + +something you would +just use without + +thinking about it, I think. + +In other words, if you'd never +learned this and you were + +trying to work out a problem you +would just use it anyway, + +because anything respectable has +to have -- well, anything + +respectable, again, +means anything + +which has this property. + +This conjugate property you can +derive that easily from + +the Fourier transform +relationships also, if you + +have a well-behaved function. + +This quantity here, this +duality, is particularly + +interesting because it isn't +really duality, it's something + +called hermitian duality. + +You start out with this formula +here to go to there + +and you use almost the same +formula to get back again. + +The only difference is instead +of a minus 2 pi ift, you have + +a plus 2 pi ift. + +In other words, this is the +conjugate of this, which is + +why this is called hermitian +duality. + +But aside from that, everything +you learn about the + +Fourier transform, you also +automatically know about the + +inverse Fourier transform for +these well-behaved functions. + +Otherwise you don't know whether +the other one exists + +or not, and we'll certainly +get into that. + +So, the duality is expressed +this way, the Fourier + +transform of, bleah. + +If you take a function, u of +t, and regard that as a + +Fourier transform, then -- + +I always have trouble +saying this. + +If you take a function, u of t, +and then you regard that as + +a function of frequency -- + +OK, that's this -- and then you +regard it as a function of + +minus frequency, namely, you +substitute minus f for t in + +whatever time function +you start with. + +You start with a time function u +of t, you substitute minus f + +for t, which gives you a +function of frequency. + +The inverse Fourier transform +of that is what you get by + +taking the Fourier transform +of u of t, and then + +substituting t for f in it. + +It's much harder to +say it than to do. + +This time shift, you've +all seen that. + +If you shift a function in +time, the only thing that + +happens is you get this +rotating term in it. + +Same thing for a frequency +shift. + +You want to have an interesting +exercise, take + +time shift plus duality and +derive the scaling and + +frequency from it -- it has to +work, and of course, it does. + +Scaling -- + +there's this relationship +here. + +This one is always +a funny one. + +It's a little strange because +when you scale here, it's not + +too surprising that when you +take a function and you squash + +it down that the Fourier +transform + +gets squashed upwards. + +Because in a sense what you're +doing when you squash a + +function down you're making +everything happen faster than + +it did before, which means that +all the frequencies in it + +are going to get higher +than they are before. + +But also when you squash it +down, the amount of energy in + +the function is going +to go down. + +One of the most important +properties that we're going to + +find and what you ought to know +already is that when you + +take the energy in a function, +you get the same answer as you + +get when you take the energy +in the Fourier transform. + +Namely, you integrate u of f +squared over frequency and you + +get the same as if you +integrate u of t + +squared over time. + +That's an important check +that you use on + +all sorts of things. + +The thing that happens now then +when you're scaling is + +when you scale a function, u +of t, you bring it down and + +you spread it out when +you bring it down. + +The frequency function goes up +so the energy in the time + +function goes down, the energy +in the frequency function goes + +up, and you need something in +order to keep the energy + +relationship working properly. + +This is what you need. + +Actually, if you derive +this, the t + +just falls out naturally. + +So we get the same thing if we +do scaling and frequency. + +I don't think I put that +down but it's the same + +relationship. + +There's differentiation. + +Differentiation we won't talk +about or use it a whole lot. + +All of these things turn out +to be remarkably robust. + +When you're dealing with L1 +functions or L2 functions and + +you scale them or you shift +them or do any of those + +things, if they're L1, they're +still L1 after you're through, + +if they're L2, they're L2 +after you're through. + +If you differentiate +a function, all + +those properties change. + +You can't be sure of +anything anymore. + +There's convolution, which I'm +sure you've derived many + +times, and which one of the +exercises derives again. + +There's correlation, and what +this sort of relationship says + +is taking products at the +frequency domain is the same + +as going through this +convolution relationship and + +the time domain. + +Of course, there's a dual +relation to that, which you + +don't use very often but +it still exists. + +Correlation is you actually get +correlation by using one + +of the conjugate properties on +the convolution and I'm sure + +you've all seen that. + +That's something you should +all have been using and + +familiar with for a long time. + +Two special cases of the Fourier +transform is that u of + +zero is what happens when you +take the Fourier transform and + +you evaluate it at +t equals zero. + +You get u of zero is just the +integral of u hat of f. + +u hat of zero is just the +integral of u of t. + +What do you use these for? + +Well the thing I use them for +is this half the time when + +you're working out a problem +it's obvious by inspection + +what this integral is or it's +obvious by inspection what + +this integral is, and by doing +that you can check whether you + +have all the constants +right in the + +transform that you've taken. + +I don't know anybody who can +take Fourier transforms + +without getting at least one +constant wrong at least half + +the time they do it. + +I probably get one constant +wrong about three-quarters of + +the time that I do it, and I'm +sure I'll do it here in class + +a number of times. + +I hope you find it, but it's one +of these things we all do. + +This is one of the best ways +of finding out what you've + +done and going back +and checking it. + +Parseval's Theorem, Parseval's +Theorem is really just this + +convolution equation which +we're applying + +at tau equals zero. + +You take the convolution, you +apply it at tau equals zero + +and what do you get? + +You get the integral of u of t +times some other conjugate -- + +the conjugate of the other +function is equal to the + +integral of u hat of +f times the complex + +conjugate of v of f. + +Much more important than this +is what happens if v happens + +to be the same as u, and that +gives you the energy equation + +here, which is what I +was talking about. + +It says the integral in a +function you can find it two + +ways, either by looking +at it in time or by + +looking at it in frequency. + +I urge you to always think +about doing this whenever + +you're working problems, because +often the Fourier + +integral it's very easy to find +the integral and the and + +the time function is +very difficult. + +A good example of this +is sinc functions + +and rectangular functions. + +Anybody can take a rectangular +function, square it and + +integrate it. + +It takes a good deal of skill +if you don't use this + +relationship to take a sinc +function, to square it and to + +integrate it. + +You can do it if you're skillful +at integration, you + +might regard it as a challenge, +but after you get + +done you realize that you've +really wasted a lot of time + +because this is the right +way of doing it here. + +Now, as I mentioned before, +it's starting to look like + +Fourier series and Fourier +integrals are much nicer when + +you have L1 functions, and they +are, but L1 functions are + +not terribly useful +as far as most + +communication functions go. + +In other words, not enough +functions are L1 to provide + +suitable models for the +communication systems that we + +want to look at. + +In fact, most of the models that +we're going to look at, + +the functions that we're dealing +with are L2 functions. + +One of the reasons for this is +this sinc function, sine x + +over x function is not L1. + +A sinc function just goes down +as 1 over t, and since it goes + +down as 1 over t, you take the +absolute value of it and you + +integrate 1 over t and what do +you get when you integrate it + +from minus infinity +to infinity. + +A function that's 1 over t, +well, if you really want to go + +through the trouble of +integrating it, you can + +integrate it over limits and you +get limits where you have + +to evaluate the limits on +a logarithmic function. + +When you get all done +with that you + +get an infinite value. + +And you can see this. + +You could take 1 over t and you +just look at it, as you go + +further and further out it just +gets bigger and bigger + +without limit. + +So, sinc t is not L1. + +Sinc function is a function +we'd like to use. + +Any function with a +discontinuity can't be the + +Fourier transform of +any L1 function. + +In other words, we said that +if you take the Fourier + +transform of an L1 function, one +of the nice things about + +it is you get a continuous +function. + +One of the nasty things +about it is you get + +a continuous function. + +Since you get a continuous +function it says that any time + +you want to deal with transforms +which are not + +continuous, you can't be talking +about time functions + +which are L1. + +One of the frequency functions +we want to look at a great + +deal is a frequency function +corresponding to a + +band-limited function. + +When you take a band-limited +function you just chop it off + +at some frequency, and usually +when you chop it off, you chop + +it off and get a +discontinuity. + +When you chop it off and get a +discountinuity, bingo, the + +time function you're dealing +with cannot be L1. + +It has to dribble away +much too slowly as + +time goes to infinity. + +That's an extraordinarily +important thing to remember. + +Any time you get a function +which is discontinuous in the + +frequency domain, the function +cannot go to zero any faster + +in a time domain than 1 over +t and vice versa in the + +frequency domain. + +L1 functions sometimes +have infinite energy. + +In other words, sinc +t is not L1 -- + +well, that's not a good example +because that's not L1, + +and it also has infinite energy, +but you can just as + +easily find functions which drop +off a little more slowly + +than sinc t, and which +have infinite + +energy because they--. + +Excuse me. + +Sometimes you have functions +which go off to infinity too + +fast as you approach time equals +zero, things which are + +a little bit like impulses +but not really. + +Impulses are awful and we'll +talk about them in a minute, + +because they don't have finite +energy as we said before. + +We have functions which just +slowly go off to infinity and + +they are L2 but they +aren't L1. + +Why do we care about those +weird functions? + +We care about them, as I said +before, because we would like + +to be able to make statements +which are simple which we can + +believe in. + +In other words, you don't want +to go through a course like + +this with a whole bunch of +things that you have to leave. + +It's very nice to have some +things that you really + +believe, and whether you believe +them or not, it's nice + +to have theorems about them. + +Even if you don't believe the +theorems, at least you have + +theorems so you can fool +other people about + +it, if nothing else. + +Well, it turns out that L2 +functions are really the right + +class to look at here. + +Oh, I think I left out +one of the most + +important things here. + +Maybe I put it down here. + +No, probably not. + +One of the reasons we want to +deal with L2 functions is if + +you're dealing with compression, +for example, and + +you take a function, if the +function has infinite energy + +in it, then one of the things +that happens is that any time + +you expand it into any kind of +orthonormal expansion or + +orthongonal expansion, which +we'll talk about later, you + +have coefficients, which +have infinite energy. + +In other words, they have +infinite values, or the sum + +squared of the coefficients +is equal to infinity. + +When we try to compress those +we're going to find that no + +matter how we do it our +mean square error + +is going to be infinite. + +Yes, we will talk about that +later when we get to talking + +about expansions. + +So for all those reasons L1 +isn't the right thing, L2 is + +the right thing. + +A function going from the reals +into the complexes, in + +other words, a complex valued +function is L2 if it's + +measurable, and if this +integral is less than + +infinity, in other words, if +that has finite energy. + +Primarily it means it has finite +energy because all the + +functions you can think +of are measurable. + +So it really says you're dealing +with functions that + +have finite energy here. + +So, let's go on to Fourier +transforms then. + +Interesting simple theorem. + +I think I stated this +last time, also. + +If a function is L2 and its time +limited, it's also L1. + +So we've already found that if +functions are L1, they have + +Fourier transforms that exist. + +The reason for this is if you +square u of t, take the + +magnitude squared of u of t for +any given t, it has to be + +less than or equal to the +sum of u of t plus 1. + +In fact, it has to be +less than that. + +Why? + +How would you prove this +if you had to prove it? + +Well, you say gee, this is +two separate terms here. + +Why don't I look at two +separate cases. + +The two separate cases are +first, suppose u of t itself + +as a magnitude less than 1. + +If u of t has and magnitude less +than 1 and you square it, + +you get something +even smaller. + +So, any time u of t has a +magnitude less than 1, u + +squared of t is less than +or equal to u of t. + +Blah blah blah blah blah +blah blah blah. + +If u of t -- + +what did I do here? + +No wonder I couldn't explain +this to you. + +Let's try it that way +and see if it works. + +If you can prove something, turn +it around and see if you + +can prove it then. + +Now, two cases. + +First one, let's suppose +that u of t is less + +than or equal to 1. + +Well then, u of t is less +than or equal to 1. + +And this is positive so this is +less than or equal to that. + +Let's look at the other case. +u of t is greater than or + +equal to 1, magnitude. + +Well then, it's less +than or equal to u + +of t magnitude squared. + +So either way this is less +than or equal to that. + +What that says is the integral +over any finite limits of u of + +t dt is less than or equal +to the integral of this. + +Well, the integral of this +splits up into the integral + +magnitude u of t squared dt +plus the integral of 1. + +Now, the integral of 1 over +any finite limits is + +just b minus a. + +That's where the finite +limits come in. + +Finite limits say you don't have +to worry about this term + +because it's finite. + +So that says at any time you +have an L2 function over a + +finite range, that function +is also L1 + +over that finite range. + +Which says that any time you +take a Fourier transform of an + +L2 function, which is only +non-zero over a finite range, + +bingo, it's L1 and you get all +these nice properties. + +It has to exist, it has to be +continuous, it has to be + +bounded, and all of +that neat stuff. + +So for any L2 function u of t, +what I'm going to try to do + +now, and I'm just copying what +a guy by the name of + +Plancherel did a +long time ago. + +The thing that Plancherel did +was he said how do I know when + +a Fourier transform +exists or not. + +I would like to make +it exist for L2 + +functions, how do I do it? + +Well, he said OK, the thing I'm +going to do is to take the + +function u of t and I'm first +going to truncate it. + +In fact, if you think in terms +of Reimann integration and + +things like that, any time you +take an integral from minus + +infinity to plus infinity, +what do you mean by it? + +You mean the limit as you +integrate the function over + +finite limits and then you let +the limits go to infinity. + +So all we're doing is +the same trick here. + +So we're going to take u of t, +we're going to truncate it to + +some minus a to plus a over some +finite range, no matter + +how big a happens to be. + +We're going to call the function +b sub a of t, u of t + +truncated to these limits. + +In other words, u of t times a +rectangular function evaluated + +at t over 2a. + +Now, can all of you look at this +function and see that it + +just means truncate from +minus a to plus a? + +No. + +Well, you should learn +to do this. + +One of the ways to do it is +to say OK, the rectangular + +function is defined as having +the value 1 between minus 1/2 + +and plus 1/2 and it's zero +everywhere else. + +I think I said that before +in class, didn't I? + +Certainly it's in the notes. + +Rectangle ft equals 1 for +t less than or equal + +to 1/2, zero else. + +So with this definition you +just evaluate what happens + +when t is equal to minus a, you +get rectangle of minus a + +over 2a, which is minus 1/2. + +When t is equal to a, you're up +to the other limit, so this + +function is 1 for t between +minus a and plus a and zero + +everywhere else. + +Please get used to using this +and become a little facile at + +sorting out what it means +because it's a very handy way + +to avoid writing awkward +things like this. + +So va of t by what we've said +is both L2 and its L1. + +We started out with a function +which is L2 and we truncated. + +Then according to this theorem +here, this function va of t is + +now time limited. + +It's also L2, and therefore, by +the theorem it's also L1. + +Therefore, it's continue and +you can take the Fourier + +transform of it -- v hat a of +f exists for all f and it's + +continuous. + +So this function is just the +Fourier transform that you get + +when you truncate the function, +which is what you + +would think of as a +way to find the + +Fourier transform anyway. + +I mean if this is not a +reasonable approximation to + +the Fourier transform a +function, you haven't modeled + +the function very well. + +Because when a gets +extraordinarily large, if + +there's anything of significance +that happens + +before year ten to the minus 6 +or which happens after year + +ten to the plus 6, and you're +dealing with electronic + +speeds, your models don't +make any sense. + +So for anything of any interest, +these functions here + +are going to start approximating +u of t, and + +therefore we hope this will +start approximating the + +Fourier transform of u of t. + +Who can make that more +precise for me? + +What happens when u of +t has finite energy? + +If it has finite energy it means +that the integral of u + +of t magnitude squared over the + +infinite interval is finite. + +So you start integrating it +over bigger and bigger + +minus a to plus a. + +What happens is as the minus +a to plus a gets bigger and + +bigger and bigger, you're +including more and more of the + +function, so that the integral +of u of t squared over that + +bigger and bigger interval has +to be getting closer and + +closer to the overall +integral of u of t. + +Which says that the energy in u +of t minus the a of t has to + +get very, very small +as a gets large. + +That's one of the reasons why +we like to deal with finite + +energy functions. + +By definition they cannot have +a appreciable energy outside + +of very large limits. + +How large those large limits +have to be depends on the + +function, but if you make them +large enough you will always + +get negligible energy outside +of those limits. + +So then we can take the Fourier +transform of this + +function within those limits and +we get something which we + +hope is going to be a reasonable +approximation of + +the Fourier transform +of u of t. + +That's what Plancherel said. + +Plancherel said if we have an +L2 function, u of t, then + +there is an L2 function u hat +of f, which is really the + +Fourier transform of u of t. + +Some people call this the +Plancherel transform of u of t + +and say that indeed Plancherel +was the one that invented + +Fourier transforms +or Plancherel + +transforms for L2 functions. + +That's probably giving him a +little too much credit, and + +Fourier somewhat less +than due credit. + +But it was a neat theorem. + +What he said is that there is +a function u hat of f, which + +we'll call the Fourier +transform, which has the + +property that when you take the +integral of the difference + +between u hat of f and the +transform of b sub a of t, + +when you take the integral +of this dt -- + +in other words, when you +evaluate the energy in the + +difference between u hat +of f and v sub a of f, + +that goes to zero. + +Well this isn't a big deal. + +In other words, this is +plausible, since this integral + +has to go to zero for an L2 +function, that's what we just + +said, then therefore, using the +energy relation, this also + +has to go to zero. + +So is this another example where +Plancherel just came + +along at the right time and he +said something totally trivial + +and became famous +because of it? + +I mean as I've urged all of +you, work on problems that + +other people haven't +worked on. + +If you're lucky, you +will do something + +trivial and become famous. + +As another piece of philosophy, +you become far + +more famous for doing something +trivial than for + +doing something difficult, +because everybody remembers + +something trivial. + +And if you do something +difficult nobody even + +understands it. + +But no, it wasn't that because +there's something hidden here. + +He says a function +like this exists. + +In other words, the problem is +these functions get closer and + +closer to something. + +They get closer and closer to +each other as a gets bigger + +and bigger. + +You can show that because +you have a + +handle on these functions. + +Whether they get closer and +closer to a real bonafide + +function or not is +another question. + +Back when you studied +arithmetic, if you were in any + +kind of advanced class studying +arithmetic, you + +studied the rational +numbers and the + +real numbers you remember. + +And you remember the problem of +what happens if you take a + +sequence of rational numbers +which is approaching a limit. + +There's a big problem there +because when you take a + +sequence of rational numbers +that approaches a limit, the + +limit might not be rational. + +In other words, when you take +sequences of things you can + +get out of the domain of the +things you're working with. + +Now, we can't get out of the +domain of being L2, but we + +might get out of domain of +measurable functions, we might + +get out of the domain +of functions at all. + +We can have all sorts of +strange things happen. + +The nice thing here, which +was really a theorem by + +[? Resenage ?] + +a long time ago. + +It says that when you take +cosine sequences of L2 + +functions, they converge +to an L2 function. + +So that's really what's +involved in here. + +So maybe this should be called +the [? Resenage ?] + +transform, I don't know. + +But anyway, whatever this says, +the theorem says, the + +first part of Plancherel's +theorem says that this + +function exists and you get a +handle on it by taking this + +transform, making a bigger and +bigger, and it says it will + +converge to something in +this energy sense. + +Bingo, when you're all done +this goes to zero. + +We're going to denote this +function as a limit and a mean + +of the Fourier transform. + +In other words, we do have a +Fourier transform in the same + +sense that we had a Fourier +series before. + +We didn't know weather the +Fourier series would converge + +at every point, but we knew that +it converged at enough + +points, namely, almost +everywhere, everywhere but on + +a set of measure zero. + +It converges so that, in fact, +you get this kind of + +relationship. + +Now, do you have to +worry about that? + +No. + +Again, this is one of these +very nice things that says + +there is a Fourier transform, +you don't have to worry about + +what goes on at these oddball +sets where the function has + +discountinuities and +things like that. + +You can forget all of that. + +You can be as careless as you've +ever been, and now you + +know that it all works out +mathematically, so long as you + +stick to L2 functions. + +So, sticking to L2 functions +says you can be a careless + +engineer, you can use lousy +mathematics and you'll always + +get the right answer. + +So, it's nice for engineers, +it's nice for me. + +I don't like to be careful +all the time. + +I like to be careful once and +then solve that and go on. + +Well, because of time frequency +duality, you can do + +exactly the same thing in +the frequency domain. + +So, you start out defining some +b, which is bigger than + +zero which is arbitrarily large, +you define a finite + +bandwidth approximation as w hat +sub b of f is u hat of f. + +We now know that u +hat of f exists + +and it's an L2 function. + +u hat of f times this +rectangular function, + +that's f over 2b. + +In other words, it's u hat of f +truncated to a big bandwidth + +minus b to plus b. + +Since w sub b of f +is L1, as well as + +L2, this always exists. + +So long as you deal with a +finite bandwidth, this + +quantity exists. + +It exists for all t and r. + +It's continuous. + +The second part of Plancherel's +theorem then says + +that the limit as b goes to +infinity of the integral of u + +of t minus this truncated +function, magnitude squared + +the energy in that, +goes to zero. + +This now is a little different +than what we did before. + +It's easier in the sense that +we don't have to worry about + +the existence of this function +because we started out with + +this to start with. + +It's a little harder because +we know that a function + +exists, but we don't know +that it's u of t. + +So, in fact, poor old Plancherel +had to do something + +other than just this very simple +argument that says all + +the energy works out right. + +He had to also show that you +really wind up with the right + +function when you get +all through with it. + +But again, this is the same +kind of energy convergence + +that we had before. + +Yeah? + +AUDIENCE: Could you discuss +non-uniqueness? + +Clearly, [INAUDIBLE] + +u hat f to satisfy Plancherel +1 and Plancherel 2. + +PROFESSOR: Yeah, in fact, any +two functions which are L2 + +equivalent. + +But you see the nice thing is +when you take this finite + +bandwidth approximation +there's only one. + +It's only when you get +to the limit that all + +of this mess occurs. + +If you take these different +possible functions, u hat of + +f, which just differ in these +negligible sets of measure + +zero, those don't affect +this integral. + +Sets of measure zero don't +affect integrals at all. + +So the mathematicians deal +with L2 theory by talking + +about equivalence classes +of functions. + +I find it hard to think about +equivalence classes of + +functions and partitioning the +set of all functions into a + +bunch of equivalence classes. + +So I just sort of remember in +the back of my mind that there + +are all these functions which +differ in a strange way. + +We'll talk about that more when +we get to the sampling + +theorem later today, +because there it + +happens to be important. + +Here it's not really important, +here we don't have + +to worry about it. + +Anyway, we can always get back +to the u of t that we started + +with in this way. + +Now, this says that all L2 +functions have Fourier + +transforms in this +very nice sense. + +In other words, at this point +you don't have to worry about + +continuity, you don't have to +worry about how fast things + +drop off, you don't have to +worry about anything. + +So long as you have finite +energy functions, this + +beautiful result always +holds true. + +There always is a Fourier +transform, it always has this + +nice property that it has the +same energy as the function + +you started with. + +The only nasty thing, as Dave +pointed out, is that, in fact, + +it might not be a unique +function, but it's close + +enough to unique. + +It's unique in an engineering +sense. + +The other thing is that L2 wave +forms don't include some + +of your favorite wave forms. + +They don't include constants, +they don't include sine waves, + +and they don't include Dirac +impulse functions. + +All of them have infinite +energy. + +I pointed out in class, spent +quite a bit of time explaining + +why an impulse function had +infinite energy by looking at + +it as a very narrow pulse of +width epsilon and a height 1 + +over epsilon, and showing that +the energy in that is 1 over + +epsilon, and as epsilon goes +to zero and the pulse gets + +narrower and narrower, bingo, +the energy goes to infinity. + +Constants are the same way, they +extend on and on forever. + +Therefore, they have infinite +energy, except if the constant + +happens to be zero. + +Sine waves are the same way, +they dribble on forever. + +So the question is are these +good models of reality? + +The answer is they're good for +some things and they're very + +bad for other things. + +The point in this course is +that if you're looking for + +wave forms that are good models +for either the kinds of + +functions that we're going to +quantize, namely, source wave + +forms, or if you're looking for +the kinds of things that + +we're going to transmit +on channels, these + +are very lousy functions. + +They don't make any sense in +a communication context. + +But anyway, where did these +things come from? + +Constants and sine waves +result from refusing to + +explicitly model when very + +long-lasting functions terminate. + +In other words, if you're +looking at a carrier function + +in a communication's system, +sine of 2 pi, f carrier times + +t, it just keeps on wiggling +around forever. + +Since you want to talk about +that over the complete time of + +interest, you don't want to say +what the time of interest + +is, you don't want to admit to +your employer that this thing + +is going to stop working after +one month because you want to + +let him think that he's going +to make a profit off of this + +forever, and you don't want to +commit to putting it into use + +in one month when you know it's +going to get delayed for + +a whole year. + +So you want to think of this as + +something which is permanent. + +You don't want to answer the +question at what time does it + +start and at what time does it +end, because for many of the + +questions you ask, you +can just regard + +it as going on forever. + +You have the same thing +with impulses. + +Impulses are always models +of short pulses. + +If you put these short pulses +through a filter, the only + +thing which is of interest +in them is what + +their integral is. + +And since the only thing of +interest is their integral, + +you call it an impulse and you +don't worry about just how + +narrow it is, except that it +has infinite energy and, + +therefore, whenever you start +to deal with a situation in + +which energy is important, these +becomes lousy models. + +So we can't use these +when we're + +talking about L2 functions. + +That's the price we pay for +dealing with L2 functions. + +But it's a small price because +for almost all the things + +we'll be dealing with, it's the +energy of the functions + +that are really important. + +So as communication wave forms, +infinite energy wave + +forms make mean square error +quantization results + +meaningless. + +In other words, when you sample +these infinite energy + +wave forms you get results that +don't make any sense, and + +they make those channel +results meaningless. + +Therefore, from now on, whether +I remember to say it + +or not, everything we deal with, +unless we're looking at + +counter examples to something, +is going to be an L2 function. + +Let's go on. + +I'm starting to feel like I'm +back in our signals and + +systems course, because at this +point I'm defining my + +third different kind +of transform. + +Fortunately, this is the last +transform we will have to talk + +about, so we're all +done with this. + +The other nice thing is that +the discrete time Fourier + +transform happens to be just the +time frequency dual of the + +Fourier series. + +So that whether you've ever +studied the dtft or not, you + +already know everything there +is to know about it, because + +the only things there are to +know about it are the results + +about Fourier series. + +So the theorem is really the +same theorem that we had for + +Fourier series. + +Assume that you have a function +of frequency, u hat + +of f -- before we had a function +of time, now we have + +a function of frequency. + +Suppose it's defined over +the interval minus w + +to plus w into c. + +In other words, a way we often +say that a function is + +truncated is to say it goes +from some interval into c. + +This is a complex function which +is non-zero only for f + +in this finite bandwidth +range. + +We want to assume that this +is L2 and thus, we + +know it's also L1. + +Then we're going to take the +Fourier coefficients. + +Before we thought of the +Fourier coefficients as + +corresponding to what goes on at +different frequencies, now + +we're going to regard them as +time quantities, and we'll see + +exactly why later. + +So we'll define these +as the Fourier + +coefficients of this function. + +So they're 1 over 2w times +this integral here. + +You remember before when we +dealt with the Fourier series, + +we went from minus t over +2 to plus t over 2. + +Now we're going from +minus w to plus w. + +Why? + +It's just convention, there's +no real reason. + +So that what's happening here +is that this is a Fourier + +series formula for a coefficient +where we're + +substituting w for t over 2. + +We're putting a plus sign in +the exponent instead of a + +minus sign. + +In other words, we're doing this +hermitian duality bit. + +What's the other difference? + +We're interchanging time +and frequency. + +Aside from that it's exactly +the same theorem that we + +established -- well, that +we stated before. + +So we know that this quantity +here, since u hat of f is L1, + +this is finite and it exists +-- that's just a finite + +complex number and nothing more +-- for all integer k. + +Also, the convergence result +when we go back, this is the + +formula we try to use to go +back to the function we + +started with. + +It's just a finite +approximation + +to the Fourier series. + +We're saying that as k zero gets +larger and larger, this + +finite approximation approaches +the function in + +energy sense. + +So this is exactly what you +should mean by a Fourier + +series anyway. + +It's exactly what you +should mean by a + +Fourier transform anyway. + +As you go to the limit with more +and more terms you get + +something which is equal to what +you started with, except + +on the set of measure zero. + +In other words, it converges +everywhere where it matters. + +It converges to something +in the sense that the + +energy is the same. + +I said that in such a way that +makes it a little simpler than + +it really is. + +You can't always say that this +converges in any nice way. + +Next time I'm going to show +you a truly awful function + +which we'll use in the Fourier +series instead of dtft, which + +is time limited and which is +just incredibly messy and + +it'll show you why you have to +be a little bit careful about + +stating these results. + +But you don't have to worry +about it most of the time, + +because this theorem +is still true. + +It's just that you have to be a +little careful about how to + +interpret it because you don't +know whether this is going to + +reach a limit or not. + +All you know is that this will +be true, this energy + +difference goes to zero. + +Also, the energy in the function +is equal to the + +energy in the coefficients. + +This was the thing that we +found so useful with the + +Fourier series. + +It's why we can play this game +that we play with mean square + +quantization error of taking a +function and then turning it + +into a sequence of samples, +trying to quantize the samples + +for minimum mean square error +and associate the mean square + +error in the samples with +the mean square + +error on the function. + +You can't do that with anything +that I know of other + +than mean square error. + +If you want to deal with other +kinds of quantization errors, + +you have a real problem +going from + +coefficients to functions. + +And finally, for any set of +numbers u sub k, if the sum is + +less than infinity, in other +words, if you're dealing with + +a sequence of finite energy, +there always is such a + +frequency function. + +Many people when they use the +discrete time Fourier + +transform think of starting with +the sequence and taking a + +sequence and saying well it's +nice to think of this sequence + +in the frequency domain, and +then they say a function f + +exists such that this is true, +or they just say that this is + +equal to that without worrying +about the convergence at all, + +which is more common. + +But since we've already gone +through all of this for the + +Fourier series, we might as well +say it right here also. + +So there's really nothing +different here. + +But now the question is why +do these u of k's -- + +I mean why do we think of those +as time coefficients? + +I mean what's really going +on in this discrete + +time Fourier transform. + +At this point it just looks like +a lot of mathematics and + +it's hard to interpret what +any of these things mean. + +Well, the next thing I want +to do is to go into + +the sampling theorem. + +The sampling theorem, in fact, +is going to interpret for you + +what this discrete time Fourier +transform is, because + +the sampling theorem and the +discrete time Fourier + +transform are just intimately +related, they're hand and + +glove with each other, +and that's the next + +thing we want to do. + +But first we have to re-write +this a little bit. + +We're going to say that this +frequency function is the + +limit in the mean of this -- + +this rectangular function is +what we use just to make sure + +we're only talking about +frequency between + +minus w and plus w. + +The limit in the mean, there's a +little notational trick that + +we use so that we can think of +this as just a limit instead + +of thinking of it as this +crazy thing that we just + +derive, which is really +not so crazy. + +That means we can talk about +this transform without always + +rubbing our noses in all +of this mess here. + +It just means that once in +awhile we go back and think + +what does this really mean. + +It means convergence in energy +rather than convergence + +point-wise, because we might +not have convergence + +point-wise. + +So we're going to write this +also as the limit in the mean + +of the sum over k of u of k. + +We're going to glop all +of this together. + +This is just some function +of k and a frequency. + +So we're going to call that phi +sub k of f at some wave + +form, and the wave +form is this. + +What happens if you look at the +relationship between to + +phi k of f and phi +k prime of f? + +Namely, if you look at two +different functions. + +These two functions are +orthongonal to each other for + +the same reason that the +functions that the sinusoid + +you used in the Fourier series +are orthongonal. + +Namely, you take this function, +you multiply it by e + +to the minus 2 pi ik prime +f over 2w times + +this rectangular function. + +You integrate from minus w +to w and what do you get? + +You're just integrating +a sinusoid -- + +the whole thing is one +big sinusoid -- + +over one period of that sinusoid +or multiple periods + +of the sinusoid. + +Actually, k minus k prime +periods of the sinusoid. + +And when you integrate a +sinusoid over a period, what + +do you get? + +You get zero. + +So it says that these functions +are all orthongonal + +to each other. + +So, presto, we have another +orthongonal expansion just + +like the Fourier series gave us +an orthongonal expansion. + +And in fact, it's the same +orthongonal expansion. + +Now the next thing to observe +is that we have done the + +Fourier transform and we've also +done the discrete time + +Fourier transform. + +In both of them we're dealing +with some frequency function. + +Now we're dealing with some +frequency function which is + +limited to minus w to plus +w, but we have two + +expansions for it. + +We have the Fourier transform, +so we can go to a function u + +of t, and we also have +this discrete + +time Fourier transform. + +So u of t is equal to this +Fourier transform here. + +Again, I should write limit in +the mean here, but then I + +think about and I say +do I have to write + +limit in the mean? + +No. + +I don't need a limit in the +mean here because I'm + +integrating this over +finite limits. + +Since I'm taking a function over +finite limits, u hat of f + +is over these limits, is an L1 +function, therefore, this + +integral exists. + +This function is a continuous +function. + +There aren't any sets of measure +zero involved here. + +This is one specific function +which is always the same. + +You know what it is exactly +at every point. + +At every point t, +this converges. + +So then what we're going to do, +what the sampling theorem + +does is it relates this to +what you get with a dtft. + +So the sampling theorem says +let u hat of f be an L2 + +function which goes from minus +ww to c, and let u of t be + +this, namely, that, which we +now know exists and is + +continuous. + +Define capital T as 1 over 2w. + +You don't have to do that if you +don't want to, but it's a + +little easier to think in terms +of some increment of + +time, T, here. + +Then u of t is continuous, +L2 and bounded. + +It's bounded by u of t less +than or equal to this. + +Why is that? + +It doesn't make any sense +as I stated it. + +Now it makes sense. + +OK, its magnitude is bounded. + +Its magnitude is bounded because +if you take u of t + +magnitude, it's equal to the +magnitude of this which is + +less than or equal to the +integral of the magnitude of + +this, which is equal to the +integral of the magnitude of + +just u hat of f, which +is what we have here. + +So all of that works nicely. + +So, u of t is a nice, +well-defined function. + +Then the other part of it is +that u of t is equal to the + +sum if its values at these +sample points times sinc of t + +minus kt over t. + +Now you've probably seen this +sampling theorem before. + +How many people haven't +seen this before? + +I mean aside from the question +of trying to do it -- + +do it in a way that +makes sense. + +OK, you've all seen it. + +So good. + +What it's saying is you can +represent a function in terms + +of just knowing what +its samples are. + +Or you can take the function, +you can sample it, and when + +you sample it if you put these +little sinc hats around all + +the samples, you get back +to the function again. + +So you take all the samples, +you then put these sincs + +around them, add them +all up, and + +bingo, you got the function. + +Let's see why that's true. + +Here's the sinc function here. + +The important thing about sinc +t, sine pi t over pi t, which + +you can see by just looking at +the sine function, is it has + +the value 1 when t +is equal to zero. + +I mean to get that value 1, you +really have to go through + +a limiting operation here to +think of sine pi t when t is + +very small as being +approximately equal to pi t. + +When you divide pi t by pi t you +get 1, so that's its value + +there and value around there. + +At every other sample point, +namely, at t equals 1, sine of + +pi t is zero. + +At t equals 2, sine of pi +t is equal to zero. + +So the sinc function is 1 at +zero and is zero at every + +other integer point. + +Now to see why it's true and to +understand what the dtft is + +all about, note that we have +said that a frequency + +function, u hat of f, can be +expressed as the sum over k -- + +and I should use a limit in the +mean here but I'm not -- + +of uk times this transform +relationship here. + +Well, these are these functions +that we talked about + +awhile ago. + +They're these functions. + +They're the sinusoids, periodic +sinusoids in k + +truncated in frequency. + +So we know that u hat of f is +equal to that dtft expansion. + +If I take the inverse Fourier +transform of that, I can take + +the inverse Fourier transform +of all these functions and + +I'll get u of t is equal to the +sum over k, of uk pk of t. + +I'm being careless about +the mathematics here. + +I've been careful about +it all along. + +The notes does it carefully, +particularly in the appendix. + +I'm not going to worry +about that here. + +If I take the function pk of +f, which is this truncated + +sinusoid, and I take the inverse +transform of that -- + +take the transform of +this, I get this. + +Can you see that just +by inspection? + +If you were really hot on these +things, if you just + +finished taking 6.003, you could +probably see that by + +inspection. + +If you remember all of those +relationships that we went + +through before, you can +see it by inspection. + +The Fourier transform of erect +function is a sinc function. + +This exponential here when you +go into the time domain + +corresponds to a time shift, +so that gives rise to this + +time shift here. + +The 1 over t is just one of +these constants you have to + +keep straight, and which I would +do just by integrating + +the things to see what I get. + +Finally, u of kt, if I look at +this, is just 1 over t times u + +of k, because these functions +here are these sinc functions, + +which are zero everywhere +but on their own point. + +So if I look at u of kt, it's a +sum over k of ck of kt, and + +ck of kt is only 1 when little +t is equal to k times capital + +T, and therefore, I get +that point there. + +Therefore, u of kt is just +1 over t times u of k. + +That finishes the sampling +theorem except for really + +tracing through all of these +things about convergence, but + +it also tells you what the +discrete time Fourier + +transform is. + +Because the discrete time +Fourier transform is just + +scaled samples of u of t. + +In other words, you start out +with this frequency function, + +you take the inverse Fourier +transform of it, you get a + +time function. + +You take the samples of that, +you scale them, and those are + +the coefficients in the +discrete time Fourier + +transform, which is what you +use discrete time Fourier + +transforms for. + +You think of sampling of +function, then you represent + +the function in terms of those +samples and then you want to + +go into the frequency domain as +a way of dealing with the + +properties of those samples, and +all you're doing is just + +going into the Fourier transform +of u of t, and all + +of that works out. + +There's one bizarre thing here, +and I'm going to talk + +about that more next time. + +That is that when you look at +this time frequency limited + +function, u hat of f, u hat of +f can be very badly behaved. + +You can have a frequency limited +function which does + +all sorts of crazy things. + +Since it's frequency limited +as inverse transform, it's + +beautifully behaved. + +It's just the sum of sinc +functions -- it's bounded, + +it's continuous and +everything else. + +When we go back into the +frequency domain it is just as + +ugly as can be. + +So what we have in the sampling +theorem, it comes out + +particularly clearly. + +Is that L1 functions in one +domain are nice, continuous, + +beautiful functions which are +not L1 in the other domain. + +So you sort of go from +L1 to continuous. + +Now when we're dealing with +L2 functions, they're not + +continuous, they're not anything +else, but you always + +go from L2 to L2. + +In other words, you can't get +out of the L2 domain, and + +therefore, when you're dealing +with L2 functions, all you + +have to worry about is L2 +functions, because you always + +stay there no matter what. + +When we start talking about +stochastic processes, we'll + +find out you always +stay there also. + +In other words, you only have +to know about one thing. + +We've seen here that to +interpret what these Fourier + +transforms mean, it's nice to +have a little idea about L1 + +functions also because when we +think of going to the limit, + +when we go to the limit we get +something which is badly + +behaved, and for these finite +time and finite frequency + +approximations, we have things +which are beautifully behaved. + +I'm going to stop now so we +can pass out the quizzes. \ No newline at end of file diff --git a/R6-LQbqUCI0.txt b/R6-LQbqUCI0.txt new file mode 100644 index 0000000000000000000000000000000000000000..b92dcd4886a20d462434b6a276f769ce21d5f6e3 --- /dev/null +++ b/R6-LQbqUCI0.txt @@ -0,0 +1,4395 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +to view additional materials from + + align:start position:0% +to view additional materials from + + + align:start position:0% +to view additional materials from +hundreds of MIT courses visit MIT open + + align:start position:0% +hundreds of MIT courses visit MIT open + + + align:start position:0% +hundreds of MIT courses visit MIT open +courseware at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu all right so um we're going + + align:start position:0% +ocw.mit.edu all right so um we're going + + + align:start position:0% +ocw.mit.edu all right so um we're going +to Now show some of the + + align:start position:0% +to Now show some of the + + + align:start position:0% +to Now show some of the +examples um and uh so again they're in + + align:start position:0% +examples um and uh so again they're in + + + align:start position:0% +examples um and uh so again they're in +our directory here examples we're now in + + align:start position:0% +our directory here examples we're now in + + + align:start position:0% +our directory here examples we're now in +the sort of section two so we're going + + align:start position:0% +the sort of section two so we're going + + + align:start position:0% +the sort of section two so we're going +to go to + + align:start position:0% +to go to + + + align:start position:0% +to go to +Applications and uh we have the section + + align:start position:0% +Applications and uh we have the section + + + align:start position:0% +Applications and uh we have the section +called perfect power + + align:start position:0% +called perfect power + + + align:start position:0% +called perfect power +law the actual example codes are all + + align:start position:0% +law the actual example codes are all + + + align:start position:0% +law the actual example codes are all +these ones called PPL 1 2 3 and four we + + align:start position:0% +these ones called PPL 1 2 3 and four we + + + align:start position:0% +these ones called PPL 1 2 3 and four we +have actually a lot of other functions + + align:start position:0% +have actually a lot of other functions + + + align:start position:0% +have actually a lot of other functions +in here which are actually really useful + + align:start position:0% +in here which are actually really useful + + + align:start position:0% +in here which are actually really useful +functions they're the functions that do + + align:start position:0% +functions they're the functions that do + + + align:start position:0% +functions they're the functions that do +all this stuff um and maybe they should + + align:start position:0% +all this stuff um and maybe they should + + + align:start position:0% +all this stuff um and maybe they should +actually get folded folded into the main + + align:start position:0% +actually get folded folded into the main + + + align:start position:0% +actually get folded folded into the main +deform distribution they're here right + + align:start position:0% +deform distribution they're here right + + + align:start position:0% +deform distribution they're here right +now um they probably could be cleaned up + + align:start position:0% +now um they probably could be cleaned up + + + align:start position:0% +now um they probably could be cleaned up +a little bit um as part of part of the + + align:start position:0% +a little bit um as part of part of the + + + align:start position:0% +a little bit um as part of part of the +homework but these are again very useful + + align:start position:0% +homework but these are again very useful + + + align:start position:0% +homework but these are again very useful +functions for allowing you to generate + + align:start position:0% +functions for allowing you to generate + + + align:start position:0% +functions for allowing you to generate +and fit these types of things all right + + align:start position:0% +and fit these types of things all right + + + align:start position:0% +and fit these types of things all right +so I + + align:start position:0% +so I + + + align:start position:0% +so I +have already started my mat lab + + align:start position:0% +have already started my mat lab + + + align:start position:0% +have already started my mat lab +session and there we are and so we will + + align:start position:0% +session and there we are and so we will + + + align:start position:0% +session and there we are and so we will +do the first one + + align:start position:0% + + + + align:start position:0% + +going along + + align:start position:0% +going along + + + align:start position:0% +going along +here + + align:start position:0% + + + + align:start position:0% + +figures all righty actually + + align:start position:0% + + + + align:start position:0% + +all right so if we go and look at what + + align:start position:0% +all right so if we go and look at what + + + align:start position:0% +all right so if we go and look at what +we did here so the first thing we did is + + align:start position:0% +we did here so the first thing we did is + + + align:start position:0% +we did here so the first thing we did is +um is we uh set our parameters for our + + align:start position:0% +um is we uh set our parameters for our + + + align:start position:0% +um is we uh set our parameters for our +power perfect power law fit so we set + + align:start position:0% +power perfect power law fit so we set + + + align:start position:0% +power perfect power law fit so we set +Alpha of 1.3 a dmax of a th000 then + + align:start position:0% +Alpha of 1.3 a dmax of a th000 then + + + align:start position:0% +Alpha of 1.3 a dmax of a th000 then +about you know approximately 30 bins we + + align:start position:0% +about you know approximately 30 bins we + + + align:start position:0% +about you know approximately 30 bins we +called our function here which is in + + align:start position:0% +called our function here which is in + + + align:start position:0% +called our function here which is in +this directory which is power law + + align:start position:0% +this directory which is power law + + + align:start position:0% +this directory which is power law +distribution which will create a power + + align:start position:0% +distribution which will create a power + + + align:start position:0% +distribution which will create a power +law distribution from these three + + align:start position:0% +law distribution from these three + + + align:start position:0% +law distribution from these three +parameters and then the first thing we + + align:start position:0% +parameters and then the first thing we + + + align:start position:0% +parameters and then the first thing we +did is just plot that distribution so we + + align:start position:0% +did is just plot that distribution so we + + + align:start position:0% +did is just plot that distribution so we +go + + align:start position:0% +go + + + align:start position:0% +go +here we go to figure one you can see + + align:start position:0% +here we go to figure one you can see + + + align:start position:0% +here we go to figure one you can see +there is that distribution so our + + align:start position:0% +there is that distribution so our + + + align:start position:0% +there is that distribution so our +perfect power law uh distribution with + + align:start position:0% +perfect power law uh distribution with + + + align:start position:0% +perfect power law uh distribution with +these parameters very nicely very nicely + + align:start position:0% + + + + align:start position:0% + +done then uh then moving along we can + + align:start position:0% +done then uh then moving along we can + + + align:start position:0% +done then uh then moving along we can +compute this is how you compute the + + align:start position:0% +compute this is how you compute the + + + align:start position:0% +compute this is how you compute the +total number of vertices from the + + align:start position:0% +total number of vertices from the + + + align:start position:0% +total number of vertices from the +distribution we just sum the no total + + align:start position:0% +distribution we just sum the no total + + + align:start position:0% +distribution we just sum the no total +number of edges we can sum there and + + align:start position:0% +number of edges we can sum there and + + + align:start position:0% +number of edges we can sum there and +then we see that the total vertices was + + align:start position:0% +then we see that the total vertices was + + + align:start position:0% +then we see that the total vertices was +18, 187 84,000 edges with an edge to + + align:start position:0% +18, 187 84,000 edges with an edge to + + + align:start position:0% +18, 187 84,000 edges with an edge to +vertex ratio of + + align:start position:0% +vertex ratio of + + + align:start position:0% +vertex ratio of +4.6 we now have a function called edges + + align:start position:0% +4.6 we now have a function called edges + + + align:start position:0% +4.6 we now have a function called edges +from distribution so if I pass in the + + align:start position:0% +from distribution so if I pass in the + + + align:start position:0% +from distribution so if I pass in the +distribution essentially the degrees and + + align:start position:0% +distribution essentially the degrees and + + + align:start position:0% +distribution essentially the degrees and +the counts it will then generate a set + + align:start position:0% +the counts it will then generate a set + + + align:start position:0% +the counts it will then generate a set +of vertices that is consistent with that + + align:start position:0% +of vertices that is consistent with that + + + align:start position:0% +of vertices that is consistent with that +distribution all right and now I'm going + + align:start position:0% +distribution all right and now I'm going + + + align:start position:0% +distribution all right and now I'm going +to create some + + align:start position:0% +to create some + + + align:start position:0% +to create some +permutations basically uh of these + + align:start position:0% +permutations basically uh of these + + + align:start position:0% +permutations basically uh of these +vertices I'm going to create a I'm going + + align:start position:0% +vertices I'm going to create a I'm going + + + align:start position:0% +vertices I'm going to create a I'm going +to uh uh randomly permute The Edge order + + align:start position:0% +to uh uh randomly permute The Edge order + + + align:start position:0% +to uh uh randomly permute The Edge order +with these two sets here so if I B tally + + align:start position:0% +with these two sets here so if I B tally + + + align:start position:0% +with these two sets here so if I B tally +make a random permutation of the number + + align:start position:0% +make a random permutation of the number + + + align:start position:0% +make a random permutation of the number +of edges okay that allows me to permute + + align:start position:0% +of edges okay that allows me to permute + + + align:start position:0% +of edges okay that allows me to permute +the edges and I can also randomly + + align:start position:0% +the edges and I can also randomly + + + align:start position:0% +the edges and I can also randomly +permute the vertex labels themselves and + + align:start position:0% +permute the vertex labels themselves and + + + align:start position:0% +permute the vertex labels themselves and +then I can look at these different + + align:start position:0% +then I can look at these different + + + align:start position:0% +then I can look at these different +permutations to see what kind of graphs + + align:start position:0% +permutations to see what kind of graphs + + + align:start position:0% +permutations to see what kind of graphs +they've created so if I don't per + + align:start position:0% +they've created so if I don't per + + + align:start position:0% +they've created so if I don't per +permute the data I just have a Zer here + + align:start position:0% +permute the data I just have a Zer here + + + align:start position:0% +permute the data I just have a Zer here +okay I just pass in the vertices that + + align:start position:0% +okay I just pass in the vertices that + + + align:start position:0% +okay I just pass in the vertices that +were created I create a no non-permuted + + align:start position:0% +were created I create a no non-permuted + + + align:start position:0% +were created I create a no non-permuted +adjacency + + align:start position:0% +adjacency + + + align:start position:0% +adjacency +Matrix okay I can then look at + + align:start position:0% + + + + align:start position:0% + +that and that just shows you this is the + + align:start position:0% +that and that just shows you this is the + + + align:start position:0% +that and that just shows you this is the +adjacency Matrix this isn't appli it + + align:start position:0% +adjacency Matrix this isn't appli it + + + align:start position:0% +adjacency Matrix this isn't appli it +just shows you that's I just created a + + align:start position:0% +just shows you that's I just created a + + + align:start position:0% +just shows you that's I just created a +Vertex that's entirely self- Loops not + + align:start position:0% +Vertex that's entirely self- Loops not + + + align:start position:0% +Vertex that's entirely self- Loops not +very interesting but nevertheless + + align:start position:0% +very interesting but nevertheless + + + align:start position:0% +very interesting but nevertheless +completely consistent with a perfect + + align:start position:0% +completely consistent with a perfect + + + align:start position:0% +completely consistent with a perfect +power law degree distribution + + align:start position:0% +power law degree distribution + + + align:start position:0% +power law degree distribution +so likewise if I just permute the + + align:start position:0% +so likewise if I just permute the + + + align:start position:0% +so likewise if I just permute the +edges so basically I take my permutation + + align:start position:0% +edges so basically I take my permutation + + + align:start position:0% +edges so basically I take my permutation +here and I just permute that okay this + + align:start position:0% +here and I just permute that okay this + + + align:start position:0% +here and I just permute that okay this +is just uh not permuting the vertex + + align:start position:0% +is just uh not permuting the vertex + + + align:start position:0% +is just uh not permuting the vertex +labels but just permuting the + + align:start position:0% +labels but just permuting the + + + align:start position:0% +labels but just permuting the +edges to the next figure here figure + + align:start position:0% +edges to the next figure here figure + + + align:start position:0% +edges to the next figure here figure +three all right and we get this + + align:start position:0% +three all right and we get this + + + align:start position:0% +three all right and we get this +distribution basically start vertex end + + align:start position:0% +distribution basically start vertex end + + + align:start position:0% +distribution basically start vertex end +vertex looks very random fairly random + + align:start position:0% +vertex looks very random fairly random + + + align:start position:0% +vertex looks very random fairly random +however you see the highest degree + + align:start position:0% +however you see the highest degree + + + align:start position:0% +however you see the highest degree +vertices are up here at 0 0 because + + align:start position:0% +vertices are up here at 0 0 because + + + align:start position:0% +vertices are up here at 0 0 because +that's the order in which the generator + + align:start position:0% +that's the order in which the generator + + + align:start position:0% +that's the order in which the generator +spits them out it gives you the highest + + align:start position:0% +spits them out it gives you the highest + + + align:start position:0% +spits them out it gives you the highest +degree vertices first and so although + + align:start position:0% +degree vertices first and so although + + + align:start position:0% +degree vertices first and so although +we've reconnected them with different + + align:start position:0% +we've reconnected them with different + + + align:start position:0% +we've reconnected them with different +edges okay you see that they still their + + align:start position:0% +edges okay you see that they still their + + + align:start position:0% +edges okay you see that they still their +vertex labels still have an in intrinsic + + align:start position:0% +vertex labels still have an in intrinsic + + + align:start position:0% +vertex labels still have an in intrinsic +order which is corresponding to vertex + + align:start position:0% +order which is corresponding to vertex + + + align:start position:0% +order which is corresponding to vertex +degree I should say this generates this + + align:start position:0% +degree I should say this generates this + + + align:start position:0% +degree I should say this generates this +naturally it's a very common way to + + align:start position:0% +naturally it's a very common way to + + + align:start position:0% +naturally it's a very common way to +if you have arbitrary vertices and you + + align:start position:0% +if you have arbitrary vertices and you + + + align:start position:0% +if you have arbitrary vertices and you +want to put them on an adjacency Matrix + + align:start position:0% +want to put them on an adjacency Matrix + + + align:start position:0% +want to put them on an adjacency Matrix +one of the first thing to do is just to + + align:start position:0% +one of the first thing to do is just to + + + align:start position:0% +one of the first thing to do is just to +reorder them according to degree you'll + + align:start position:0% +reorder them according to degree you'll + + + align:start position:0% +reorder them according to degree you'll +always get some kind of structure that + + align:start position:0% +always get some kind of structure that + + + align:start position:0% +always get some kind of structure that +emerges there and it's an often an + + align:start position:0% +emerges there and it's an often an + + + align:start position:0% +emerges there and it's an often an +easier way to kind of see what's going + + align:start position:0% +easier way to kind of see what's going + + + align:start position:0% +easier way to kind of see what's going +on there and as you can see from the + + align:start position:0% +on there and as you can see from the + + + align:start position:0% +on there and as you can see from the +previous data if you saw if you ordered + + align:start position:0% +previous data if you saw if you ordered + + + align:start position:0% +previous data if you saw if you ordered +things by degree and you saw this type + + align:start position:0% +things by degree and you saw this type + + + align:start position:0% +things by degree and you saw this type +of distribution be like aha that looks a + + align:start position:0% +of distribution be like aha that looks a + + + align:start position:0% +of distribution be like aha that looks a +lot like a power law distribution just + + align:start position:0% +lot like a power law distribution just + + + align:start position:0% +lot like a power law distribution just +from the kind of the the scatter of the + + align:start position:0% +from the kind of the the scatter of the + + + align:start position:0% +from the kind of the the scatter of the +dots + + align:start position:0% +dots + + + align:start position:0% +dots +so moving on here so now we're just + + align:start position:0% +so moving on here so now we're just + + + align:start position:0% +so moving on here so now we're just +going to permute the vertex labels so we + + align:start position:0% +going to permute the vertex labels so we + + + align:start position:0% +going to permute the vertex labels so we +are not permuting the edges just the + + align:start position:0% +are not permuting the edges just the + + + align:start position:0% +are not permuting the edges just the +vertex + + align:start position:0% + + + + align:start position:0% + +labels and so if you see + + align:start position:0% +labels and so if you see + + + align:start position:0% +labels and so if you see +here and then by permuting the vertex + + align:start position:0% +here and then by permuting the vertex + + + align:start position:0% +here and then by permuting the vertex +labels it looks random but fairly sparse + + align:start position:0% +labels it looks random but fairly sparse + + + align:start position:0% +labels it looks random but fairly sparse +that's because we still every single + + align:start position:0% +that's because we still every single + + + align:start position:0% +that's because we still every single +time you know we've moved the vertex + + align:start position:0% +time you know we've moved the vertex + + + align:start position:0% +time you know we've moved the vertex +labels around but all the edges + + align:start position:0% +labels around but all the edges + + + align:start position:0% +labels around but all the edges +associated with that vertex pair still + + align:start position:0% +associated with that vertex pair still + + + align:start position:0% +associated with that vertex pair still +will ship shipped around in sync we + + align:start position:0% +will ship shipped around in sync we + + + align:start position:0% +will ship shipped around in sync we +haven't done anything to break them up + + align:start position:0% +haven't done anything to break them up + + + align:start position:0% +haven't done anything to break them up +whereas before we broke up the edges but + + align:start position:0% +whereas before we broke up the edges but + + + align:start position:0% +whereas before we broke up the edges but +we didn't change the + + align:start position:0% +we didn't change the + + + align:start position:0% +we didn't change the +labels and so then the final one which + + align:start position:0% +labels and so then the final one which + + + align:start position:0% +labels and so then the final one which +is the one that we typically do when we + + align:start position:0% +is the one that we typically do when we + + + align:start position:0% +is the one that we typically do when we +want to create random is we permute both + + align:start position:0% +want to create random is we permute both + + + align:start position:0% +want to create random is we permute both +the vertices and the edges all right to + + align:start position:0% +the vertices and the edges all right to + + + align:start position:0% +the vertices and the edges all right to +create sort of a truly random looking uh + + align:start position:0% +create sort of a truly random looking uh + + + align:start position:0% +create sort of a truly random looking uh +adjacency Matrix and there you see you + + align:start position:0% +adjacency Matrix and there you see you + + + align:start position:0% +adjacency Matrix and there you see you +have something and now and now what you + + align:start position:0% +have something and now and now what you + + + align:start position:0% +have something and now and now what you +can also see here is these high degree + + align:start position:0% +can also see here is these high degree + + + align:start position:0% +can also see here is these high degree +vertices uh you know uh do stand out + + align:start position:0% +vertices uh you know uh do stand out + + + align:start position:0% +vertices uh you know uh do stand out +this is a very standard power law + + align:start position:0% +this is a very standard power law + + + align:start position:0% +this is a very standard power law +distribution you'll see these sort of + + align:start position:0% +distribution you'll see these sort of + + + align:start position:0% +distribution you'll see these sort of +dense rows and uh and and columns in + + align:start position:0% +dense rows and uh and and columns in + + + align:start position:0% +dense rows and uh and and columns in +there that are indicative of these very + + align:start position:0% +there that are indicative of these very + + + align:start position:0% +there that are indicative of these very +high degree nodes uh when we just when + + align:start position:0% +high degree nodes uh when we just when + + + align:start position:0% +high degree nodes uh when we just when +we didn't when we just permuted the + + align:start position:0% +we didn't when we just permuted the + + + align:start position:0% +we didn't when we just permuted the +edges but not the the the the vertices + + align:start position:0% +edges but not the the the the vertices + + + align:start position:0% +edges but not the the the the vertices +these high degree uh rows and columns + + align:start position:0% +these high degree uh rows and columns + + + align:start position:0% +these high degree uh rows and columns +all got shifted up into the corner of + + align:start position:0% +all got shifted up into the corner of + + + align:start position:0% +all got shifted up into the corner of +the plot so so again another way to sort + + align:start position:0% +the plot so so again another way to sort + + + align:start position:0% +the plot so so again another way to sort +of begin to look at the data in a way to + + align:start position:0% +of begin to look at the data in a way to + + + align:start position:0% +of begin to look at the data in a way to +sort of recognize structure H I think + + align:start position:0% +sort of recognize structure H I think + + + align:start position:0% +sort of recognize structure H I think +these adjacency matrices once you start + + align:start position:0% +these adjacency matrices once you start + + + align:start position:0% +these adjacency matrices once you start +looking at them you begin to certain get + + align:start position:0% +looking at them you begin to certain get + + + align:start position:0% +looking at them you begin to certain get +a comfort for them just as we do with + + align:start position:0% +a comfort for them just as we do with + + + align:start position:0% +a comfort for them just as we do with +other types of data we begin to learn + + align:start position:0% +other types of data we begin to learn + + + align:start position:0% +other types of data we begin to learn +what they what they look like um this is + + align:start position:0% +what they what they look like um this is + + + align:start position:0% +what they what they look like um this is +a very good way to look at the data + + align:start position:0% +a very good way to look at the data + + + align:start position:0% +a very good way to look at the data +because you can look at a fair amount if + + align:start position:0% +because you can look at a fair amount if + + + align:start position:0% +because you can look at a fair amount if +I were to actually plot the graph of + + align:start position:0% +I were to actually plot the graph of + + + align:start position:0% +I were to actually plot the graph of +18,000 vertices as a traditional graph + + align:start position:0% +18,000 vertices as a traditional graph + + + align:start position:0% +18,000 vertices as a traditional graph +with vertices and lines connecting them + + align:start position:0% +with vertices and lines connecting them + + + align:start position:0% +with vertices and lines connecting them +it would just be blue the entire screen + + align:start position:0% +it would just be blue the entire screen + + + align:start position:0% +it would just be blue the entire screen +would be blue there would be no way to + + align:start position:0% +would be blue there would be no way to + + + align:start position:0% +would be blue there would be no way to +properly uh position those vertices uh + + align:start position:0% +properly uh position those vertices uh + + + align:start position:0% +properly uh position those vertices uh +here you know this is 8 4,000 data + + align:start position:0% +here you know this is 8 4,000 data + + + align:start position:0% +here you know this is 8 4,000 data +points and I can still kind of see it a + + align:start position:0% +points and I can still kind of see it a + + + align:start position:0% +points and I can still kind of see it a +little + + align:start position:0% +little + + + align:start position:0% +little +bit this is kind of the limit 100,000 + + align:start position:0% +bit this is kind of the limit 100,000 + + + align:start position:0% +bit this is kind of the limit 100,000 +edges is kind of the limit of what you + + align:start position:0% +edges is kind of the limit of what you + + + align:start position:0% +edges is kind of the limit of what you +can put on any plot to really see it + + align:start position:0% +can put on any plot to really see it + + + align:start position:0% +can put on any plot to really see it +unless there's some sort of hidden + + align:start position:0% +unless there's some sort of hidden + + + align:start position:0% +unless there's some sort of hidden +structure that allows you to like you + + align:start position:0% +structure that allows you to like you + + + align:start position:0% +structure that allows you to like you +know really really you know move it all + + align:start position:0% +know really really you know move it all + + + align:start position:0% +know really really you know move it all +together um but you know the adjacency + + align:start position:0% +together um but you know the adjacency + + + align:start position:0% +together um but you know the adjacency +Matrix is a great way to look at fairly + + align:start position:0% +Matrix is a great way to look at fairly + + + align:start position:0% +Matrix is a great way to look at fairly +large uh + + align:start position:0% +large uh + + + align:start position:0% +large uh +graphs so when so the so we generally do + + align:start position:0% +graphs so when so the so we generally do + + + align:start position:0% +graphs so when so the so we generally do +that so this is just this is this is the + + align:start position:0% +that so this is just this is this is the + + + align:start position:0% +that so this is just this is this is the +procedure create you know your perfect + + align:start position:0% +procedure create you know your perfect + + + align:start position:0% +procedure create you know your perfect +power law distribution + + align:start position:0% +power law distribution + + + align:start position:0% +power law distribution +create some edges create some + + align:start position:0% +create some edges create some + + + align:start position:0% +create some edges create some +permutations and then permute it and + + align:start position:0% +permutations and then permute it and + + + align:start position:0% +permutations and then permute it and +then off you are you've just created a + + align:start position:0% +then off you are you've just created a + + + align:start position:0% +then off you are you've just created a +per randomized perfect Power log graph + + align:start position:0% +per randomized perfect Power log graph + + + align:start position:0% +per randomized perfect Power log graph +again this is a this is an example of a + + align:start position:0% +again this is a this is an example of a + + + align:start position:0% +again this is a this is an example of a +code where you probably might even just + + align:start position:0% +code where you probably might even just + + + align:start position:0% +code where you probably might even just +take this program and adjust it to suit + + align:start position:0% +take this program and adjust it to suit + + + align:start position:0% +take this program and adjust it to suit +your + + align:start position:0% +your + + + align:start position:0% +your +needs and then I think we did that and + + align:start position:0% +needs and then I think we did that and + + + align:start position:0% +needs and then I think we did that and +then finally we plotted the degree + + align:start position:0% +then finally we plotted the degree + + + align:start position:0% +then finally we plotted the degree +distribution of A3 just to see show you + + align:start position:0% +distribution of A3 just to see show you + + + align:start position:0% +distribution of A3 just to see show you +that I'm not lying and again the the + + align:start position:0% +that I'm not lying and again the the + + + align:start position:0% +that I'm not lying and again the the +triangle was the original and the blue + + align:start position:0% +triangle was the original and the blue + + + align:start position:0% +triangle was the original and the blue +was the thing and you see + + align:start position:0% +was the thing and you see + + + align:start position:0% +was the thing and you see +throughout all those permutations our + + align:start position:0% +throughout all those permutations our + + + align:start position:0% +throughout all those permutations our +degree distribution remain the same even + + align:start position:0% +degree distribution remain the same even + + + align:start position:0% +degree distribution remain the same even +though they look those would be + + align:start position:0% +though they look those would be + + + align:start position:0% +though they look those would be +completely different graphs their degree + + align:start position:0% +completely different graphs their degree + + + align:start position:0% +completely different graphs their degree +distributions are are + + align:start position:0% +distributions are are + + + align:start position:0% +distributions are are +identical all + + align:start position:0% +identical all + + + align:start position:0% +identical all +right so let's move on + + align:start position:0% + + + + align:start position:0% + +here all righty so this is just showing + + align:start position:0% +here all righty so this is just showing + + + align:start position:0% +here all righty so this is just showing +so we actually rolled this up all into + + align:start position:0% +so we actually rolled this up all into + + + align:start position:0% +so we actually rolled this up all into +one function here for you Rand power law + + align:start position:0% +one function here for you Rand power law + + + align:start position:0% +one function here for you Rand power law +Matrix if you give it an alpha a dmax + + align:start position:0% +Matrix if you give it an alpha a dmax + + + align:start position:0% +Matrix if you give it an alpha a dmax +and an ND it will do those three steps + + align:start position:0% +and an ND it will do those three steps + + + align:start position:0% +and an ND it will do those three steps +for you that I had in the previous chart + + align:start position:0% +for you that I had in the previous chart + + + align:start position:0% +for you that I had in the previous chart +all in one thing and produce an + + align:start position:0% +all in one thing and produce an + + + align:start position:0% +all in one thing and produce an +adjacency Matrix that's uh that's a + + align:start position:0% +adjacency Matrix that's uh that's a + + + align:start position:0% +adjacency Matrix that's uh that's a +perfect power law based on these on + + align:start position:0% +perfect power law based on these on + + + align:start position:0% +perfect power law based on these on +these parameters and again you saw we + + align:start position:0% +these parameters and again you saw we + + + align:start position:0% +these parameters and again you saw we +have the same number of vertices that we + + align:start position:0% +have the same number of vertices that we + + + align:start position:0% +have the same number of vertices that we +saw and edges and ratio that we saw + + align:start position:0% +saw and edges and ratio that we saw + + + align:start position:0% +saw and edges and ratio that we saw +before so that's all the same uh now + + align:start position:0% +before so that's all the same uh now + + + align:start position:0% +before so that's all the same uh now +we're going to transform this data clean + + align:start position:0% +we're going to transform this data clean + + + align:start position:0% +we're going to transform this data clean +up this data by making it uh uh making + + align:start position:0% +up this data by making it uh uh making + + + align:start position:0% +up this data by making it uh uh making +it unweighted undirected we're going to + + align:start position:0% +it unweighted undirected we're going to + + + align:start position:0% +it unweighted undirected we're going to +eliminate self Loops we're going to take + + align:start position:0% +eliminate self Loops we're going to take + + + align:start position:0% +eliminate self Loops we're going to take +the upper triangular Port uh here's + + align:start position:0% +the upper triangular Port uh here's + + + align:start position:0% +the upper triangular Port uh here's +another one it's unweighted no self + + align:start position:0% +another one it's unweighted no self + + + align:start position:0% +another one it's unweighted no self +Loops different versions of them and + + align:start position:0% +Loops different versions of them and + + + align:start position:0% +Loops different versions of them and +then we do uh you can see what those + + align:start position:0% +then we do uh you can see what those + + + align:start position:0% +then we do uh you can see what those +that looks + + align:start position:0% +that looks + + + align:start position:0% +that looks +like so if we look at the first one here + + align:start position:0% +like so if we look at the first one here + + + align:start position:0% +like so if we look at the first one here +so this just shows the unweighted what + + align:start position:0% +so this just shows the unweighted what + + + align:start position:0% +so this just shows the unweighted what +unweighting just basically making the + + align:start position:0% +unweighting just basically making the + + + align:start position:0% +unweighting just basically making the +data unweighted does to the data set so + + align:start position:0% +data unweighted does to the data set so + + + align:start position:0% +data unweighted does to the data set so +this the the the triangles are the + + align:start position:0% +this the the the triangles are the + + + align:start position:0% +this the the the triangles are the +original data and just making it + + align:start position:0% +original data and just making it + + + align:start position:0% +original data and just making it +unweighted how it just distorts that + + align:start position:0% +unweighted how it just distorts that + + + align:start position:0% +unweighted how it just distorts that +that uh that data + + align:start position:0% +that uh that data + + + align:start position:0% +that uh that data +set we go + + align:start position:0% +set we go + + + align:start position:0% +set we go +here this just shows you what happens + + align:start position:0% +here this just shows you what happens + + + align:start position:0% +here this just shows you what happens +when you make it + + align:start position:0% +when you make it + + + align:start position:0% +when you make it +undirected so unweighted means we took + + align:start position:0% +undirected so unweighted means we took + + + align:start position:0% +undirected so unweighted means we took +everything everything all the any cases + + align:start position:0% +everything everything all the any cases + + + align:start position:0% +everything everything all the any cases +where we had vertices with more than one + + align:start position:0% +where we had vertices with more than one + + + align:start position:0% +where we had vertices with more than one +connection to them if something had five + + align:start position:0% +connection to them if something had five + + + align:start position:0% +connection to them if something had five +connections now it just gets one + + align:start position:0% +connections now it just gets one + + + align:start position:0% +connections now it just gets one +connection and so that was a fairly big + + align:start position:0% +connection and so that was a fairly big + + + align:start position:0% +connection and so that was a fairly big +distortion + + align:start position:0% +distortion + + + align:start position:0% +distortion +example is like if you you take a like a + + align:start position:0% +example is like if you you take a like a + + + align:start position:0% +example is like if you you take a like a +person's social network graph and if you + + align:start position:0% +person's social network graph and if you + + + align:start position:0% +person's social network graph and if you +were to make it + + align:start position:0% +were to make it + + + align:start position:0% +were to make it +unweighted what you're saying is that + + align:start position:0% +unweighted what you're saying is that + + + align:start position:0% +unweighted what you're saying is that +the fact that the connection you have + + align:start position:0% +the fact that the connection you have + + + align:start position:0% +the fact that the connection you have +with your spouse is identical to with + + align:start position:0% +with your spouse is identical to with + + + align:start position:0% +with your spouse is identical to with +someone that you emailed once or that + + align:start position:0% +someone that you emailed once or that + + + align:start position:0% +someone that you emailed once or that +you friended once right and I think we + + align:start position:0% +you friended once right and I think we + + + align:start position:0% +you friended once right and I think we +all agree that that's a fair amount of + + align:start position:0% +all agree that that's a fair amount of + + + align:start position:0% +all agree that that's a fair amount of +information that's lost there and so + + align:start position:0% +information that's lost there and so + + + align:start position:0% +information that's lost there and so +again encouraging folks to uh to uh to + + align:start position:0% +again encouraging folks to uh to uh to + + + align:start position:0% +again encouraging folks to uh to uh to +not to to be aware of that and to to + + align:start position:0% +not to to be aware of that and to to + + + align:start position:0% +not to to be aware of that and to to +sort of you know be careful of when + + align:start position:0% +sort of you know be careful of when + + + align:start position:0% +sort of you know be careful of when +they're doing again making it undirected + + align:start position:0% +they're doing again making it undirected + + + align:start position:0% +they're doing again making it undirected +just means we basically you know uh you + + align:start position:0% +just means we basically you know uh you + + + align:start position:0% +just means we basically you know uh you +know if if if if if I phone you a lot or + + align:start position:0% +know if if if if if I phone you a lot or + + + align:start position:0% +know if if if if if I phone you a lot or +I site you a lot in papers you know + + align:start position:0% +I site you a lot in papers you know + + + align:start position:0% +I site you a lot in papers you know +that's the same as you citing me a lot + + align:start position:0% +that's the same as you citing me a lot + + + align:start position:0% +that's the same as you citing me a lot +which you lose some information there um + + align:start position:0% +which you lose some information there um + + + align:start position:0% +which you lose some information there um +again and this just shows the kind of + + align:start position:0% +again and this just shows the kind of + + + align:start position:0% +again and this just shows the kind of +distortion that we get from just making + + align:start position:0% +distortion that we get from just making + + + align:start position:0% +distortion that we get from just making +it + + align:start position:0% + + + + align:start position:0% + +undirected and then again this shows + + align:start position:0% +undirected and then again this shows + + + align:start position:0% +undirected and then again this shows +what happens when you do no so no self + + align:start position:0% +what happens when you do no so no self + + + align:start position:0% +what happens when you do no so no self +Loops well this there's not a lot of + + align:start position:0% +Loops well this there's not a lot of + + + align:start position:0% +Loops well this there's not a lot of +self Loops so we only have affected a + + align:start position:0% +self Loops so we only have affected a + + + align:start position:0% +self Loops so we only have affected a +few vertices here so in this + + align:start position:0% +few vertices here so in this + + + align:start position:0% +few vertices here so in this +case eliminating self Loops is not a + + align:start position:0% +case eliminating self Loops is not a + + + align:start position:0% +case eliminating self Loops is not a +terribly distorted doesn't really + + align:start position:0% +terribly distorted doesn't really + + + align:start position:0% +terribly distorted doesn't really +distort the data very much at all then + + align:start position:0% +distort the data very much at all then + + + align:start position:0% +distort the data very much at all then +finally this shows the cor the upper + + align:start position:0% +finally this shows the cor the upper + + + align:start position:0% +finally this shows the cor the upper +correlation Matrix so when we correlated + + align:start position:0% +correlation Matrix so when we correlated + + + align:start position:0% +correlation Matrix so when we correlated +the two basically multiplied the + + align:start position:0% +the two basically multiplied the + + + align:start position:0% +the two basically multiplied the +adjacent together again showing what we + + align:start position:0% +adjacent together again showing what we + + + align:start position:0% +adjacent together again showing what we +what we saw + + align:start position:0% +what we saw + + + align:start position:0% +what we saw +before all right moving on + + align:start position:0% + + + + align:start position:0% + +ah you get to see the plots that got + + align:start position:0% +ah you get to see the plots that got + + + align:start position:0% +ah you get to see the plots that got +eliminated from by + + align:start position:0% +eliminated from by + + + align:start position:0% +eliminated from by +PowerPoint mat lab has defeated + + align:start position:0% +PowerPoint mat lab has defeated + + + align:start position:0% +PowerPoint mat lab has defeated +PowerPoints attempts to deny you your + + align:start position:0% +PowerPoints attempts to deny you your + + + align:start position:0% +PowerPoints attempts to deny you your +education so um all right so again what + + align:start position:0% +education so um all right so again what + + + align:start position:0% +education so um all right so again what +we're doing here is we're uh we're uh + + align:start position:0% +we're doing here is we're uh we're uh + + + align:start position:0% +we're doing here is we're uh we're uh +we're creating a perfect power law all + + align:start position:0% +we're creating a perfect power law all + + + align:start position:0% +we're creating a perfect power law all +right this is a bigger one I wanted a + + align:start position:0% +right this is a bigger one I wanted a + + + align:start position:0% +right this is a bigger one I wanted a +lot of vertices so this time we had + + align:start position:0% +lot of vertices so this time we had + + + align:start position:0% +lot of vertices so this time we had +50,000 vertices 329,000 edges uh with a + + align:start position:0% +50,000 vertices 329,000 edges uh with a + + + align:start position:0% +50,000 vertices 329,000 edges uh with a +ratio of 6 and a half we create our + + align:start position:0% +ratio of 6 and a half we create our + + + align:start position:0% +ratio of 6 and a half we create our +vertices we randomize The Edge order Etc + + align:start position:0% +vertices we randomize The Edge order Etc + + + align:start position:0% +vertices we randomize The Edge order Etc +now we're going to randomly pick just a + + align:start position:0% +now we're going to randomly pick just a + + + align:start position:0% +now we're going to randomly pick just a +subsample of these and what do F samp + + align:start position:0% +subsample of these and what do F samp + + + align:start position:0% +subsample of these and what do F samp +set it it's 140th so I'm just going to + + align:start position:0% +set it it's 140th so I'm just going to + + + align:start position:0% +set it it's 140th so I'm just going to +take 1 140th of all the vertices okay + + align:start position:0% +take 1 140th of all the vertices okay + + + align:start position:0% +take 1 140th of all the vertices okay +now I'm going to go and compute that + + align:start position:0% +now I'm going to go and compute that + + + align:start position:0% +now I'm going to go and compute that +degree and I'm going to basically + + align:start position:0% +degree and I'm going to basically + + + align:start position:0% +degree and I'm going to basically +subsample all of these + + align:start position:0% +subsample all of these + + + align:start position:0% +subsample all of these +and later what you'll see so let's just + + align:start position:0% +and later what you'll see so let's just + + + align:start position:0% +and later what you'll see so let's just +take a look at + + align:start position:0% + + + + align:start position:0% + +that so this just shows that chart here + + align:start position:0% +that so this just shows that chart here + + + align:start position:0% +that so this just shows that chart here +so this is the original data again this + + align:start position:0% +so this is the original data again this + + + align:start position:0% +so this is the original data again this +is the vertex we're sorting by the + + align:start position:0% +is the vertex we're sorting by the + + + align:start position:0% +is the vertex we're sorting by the +vertices by degree here so this is the + + align:start position:0% +vertices by degree here so this is the + + + align:start position:0% +vertices by degree here so this is the +highest degree vertex these are the + + align:start position:0% +highest degree vertex these are the + + + align:start position:0% +highest degree vertex these are the +lowest uh degree + + align:start position:0% +lowest uh degree + + + align:start position:0% +lowest uh degree +vertex okay and and this each vertex is + + align:start position:0% +vertex okay and and this each vertex is + + + align:start position:0% +vertex okay and and this each vertex is +getting a DOT here so we have 50,000 + + align:start position:0% +getting a DOT here so we have 50,000 + + + align:start position:0% +getting a DOT here so we have 50,000 +vertices they all get a DOT they all get + + align:start position:0% +vertices they all get a DOT they all get + + + align:start position:0% +vertices they all get a DOT they all get +a DOT here and we've only taken a 40th + + align:start position:0% +a DOT here and we've only taken a 40th + + + align:start position:0% +a DOT here and we've only taken a 40th +them and this just shows you here you + + align:start position:0% +them and this just shows you here you + + + align:start position:0% +them and this just shows you here you +know kind of what the if you if you only + + align:start position:0% +know kind of what the if you if you only + + + align:start position:0% +know kind of what the if you if you only +take a 40th of them and then compute + + align:start position:0% +take a 40th of them and then compute + + + align:start position:0% +take a 40th of them and then compute +their sample this is what you what you + + align:start position:0% +their sample this is what you what you + + + align:start position:0% +their sample this is what you what you +get now standard samply sampling Theory + + align:start position:0% +get now standard samply sampling Theory + + + align:start position:0% +get now standard samply sampling Theory +would say aha well I know how to correct + + align:start position:0% +would say aha well I know how to correct + + + align:start position:0% +would say aha well I know how to correct +for this the way I correct for this is I + + align:start position:0% +for this the way I correct for this is I + + + align:start position:0% +for this the way I correct for this is I +just multiply my sample data by 40 I + + align:start position:0% +just multiply my sample data by 40 I + + + align:start position:0% +just multiply my sample data by 40 I +only took 140 so that means you know + + align:start position:0% +only took 140 so that means you know + + + align:start position:0% +only took 140 so that means you know +whenever I measured it the the True + + align:start position:0% +whenever I measured it the the True + + + align:start position:0% +whenever I measured it the the True +Value should be 40 times higher so we + + align:start position:0% +Value should be 40 times higher so we + + + align:start position:0% +Value should be 40 times higher so we +can look at that in figure two so this + + align:start position:0% +can look at that in figure two so this + + + align:start position:0% +can look at that in figure two so this +is the true sample all + + align:start position:0% + + + + align:start position:0% + +right so again which we see for our high + + align:start position:0% +right so again which we see for our high + + + align:start position:0% +right so again which we see for our high +degree vertices here this is the highest + + align:start position:0% +degree vertices here this is the highest + + + align:start position:0% +degree vertices here this is the highest +degree vertix here again so this is the + + align:start position:0% +degree vertix here again so this is the + + + align:start position:0% +degree vertix here again so this is the +high degree vertices these are the low + + align:start position:0% +high degree vertices these are the low + + + align:start position:0% +high degree vertices these are the low +deegree vertices I don't know if I said + + align:start position:0% +deegree vertices I don't know if I said + + + align:start position:0% +deegree vertices I don't know if I said +that opposite when I mentioned it before + + align:start position:0% +that opposite when I mentioned it before + + + align:start position:0% +that opposite when I mentioned it before +this is the highest degree verx and you + + align:start position:0% +this is the highest degree verx and you + + + align:start position:0% +this is the highest degree verx and you +see that by sampling the data we're + + align:start position:0% +see that by sampling the data we're + + + align:start position:0% +see that by sampling the data we're +doing a very good job on the high degree + + align:start position:0% +doing a very good job on the high degree + + + align:start position:0% +doing a very good job on the high degree +vertices we're sampling them just fine + + align:start position:0% +vertices we're sampling them just fine + + + align:start position:0% +vertices we're sampling them just fine +and that's that's kind of why statistics + + align:start position:0% +and that's that's kind of why statistics + + + align:start position:0% +and that's that's kind of why statistics +works right you know you know if you if + + align:start position:0% +works right you know you know if you if + + + align:start position:0% +works right you know you know if you if +if something is really not rare and you + + align:start position:0% +if something is really not rare and you + + + align:start position:0% +if something is really not rare and you +sample you're going to get a you're + + align:start position:0% +sample you're going to get a you're + + + align:start position:0% +sample you're going to get a you're +going to get a good estimate however for + + align:start position:0% +going to get a good estimate however for + + + align:start position:0% +going to get a good estimate however for +these low degree vertices over here what + + align:start position:0% +these low degree vertices over here what + + + align:start position:0% +these low degree vertices over here what +you see by + + align:start position:0% +you see by + + + align:start position:0% +you see by +multiplying by 40 we're significantly + + align:start position:0% +multiplying by 40 we're significantly + + + align:start position:0% +multiplying by 40 we're significantly +overestimating their probability all + + align:start position:0% +overestimating their probability all + + + align:start position:0% +overestimating their probability all +right as I say this is the curve that + + align:start position:0% +right as I say this is the curve that + + + align:start position:0% +right as I say this is the curve that +proves that Optimist and pessimists are + + align:start position:0% +proves that Optimist and pessimists are + + + align:start position:0% +proves that Optimist and pessimists are +both + + align:start position:0% + + + + align:start position:0% + +correct there are so many rare thing if + + align:start position:0% +correct there are so many rare thing if + + + align:start position:0% +correct there are so many rare thing if +the world is a power law distribution + + align:start position:0% +the world is a power law distribution + + + align:start position:0% +the world is a power law distribution +means that there are so many rare events + + align:start position:0% +means that there are so many rare events + + + align:start position:0% +means that there are so many rare events +in the world some of them are going to + + align:start position:0% +in the world some of them are going to + + + align:start position:0% +in the world some of them are going to +happen to + + align:start position:0% +happen to + + + align:start position:0% +happen to +you so it means if you're an optimist go + + align:start position:0% +you so it means if you're an optimist go + + + align:start position:0% +you so it means if you're an optimist go +play the lottery all right if you're + + align:start position:0% +play the lottery all right if you're + + + align:start position:0% +play the lottery all right if you're +pessimist it means yeah lightning could + + align:start position:0% +pessimist it means yeah lightning could + + + align:start position:0% +pessimist it means yeah lightning could +hit you and you better just be you know + + align:start position:0% +hit you and you better just be you know + + + align:start position:0% +hit you and you better just be you know +stick and stay inside so there's just so + + align:start position:0% +stick and stay inside so there's just so + + + align:start position:0% +stick and stay inside so there's just so +many rare things that you know uh some + + align:start position:0% +many rare things that you know uh some + + + align:start position:0% +many rare things that you know uh some +of them are going to some really rare + + align:start position:0% +of them are going to some really rare + + + align:start position:0% +of them are going to some really rare +things are going to happen to you in + + align:start position:0% +things are going to happen to you in + + + align:start position:0% +things are going to happen to you in +your lifetime most likely those rare + + align:start position:0% +your lifetime most likely those rare + + + align:start position:0% +your lifetime most likely those rare +things though are very mundane you + + align:start position:0% +things though are very mundane you + + + align:start position:0% +things though are very mundane you +know so so but we can correct for this + + align:start position:0% +know so so but we can correct for this + + + align:start position:0% +know so so but we can correct for this +and so we have some some basically a way + + align:start position:0% +and so we have some some basically a way + + + align:start position:0% +and so we have some some basically a way +here of deriving calculations we compute + + align:start position:0% +here of deriving calculations we compute + + + align:start position:0% +here of deriving calculations we compute +the parameters of our distribution and + + align:start position:0% +the parameters of our distribution and + + + align:start position:0% +the parameters of our distribution and +through these two functions compute + + align:start position:0% +through these two functions compute + + + align:start position:0% +through these two functions compute +degree correction and apply degree + + align:start position:0% +degree correction and apply degree + + + align:start position:0% +degree correction and apply degree +correction we can actually go back and + + align:start position:0% +correction we can actually go back and + + + align:start position:0% +correction we can actually go back and +sort of say all right given that we + + align:start position:0% +sort of say all right given that we + + + align:start position:0% +sort of say all right given that we +believe the data is power law and we've + + align:start position:0% +believe the data is power law and we've + + + align:start position:0% +believe the data is power law and we've +sampled it can we then come up with a + + align:start position:0% +sampled it can we then come up with a + + + align:start position:0% +sampled it can we then come up with a +more uniform correction that basically + + align:start position:0% +more uniform correction that basically + + + align:start position:0% +more uniform correction that basically +gives us a better estimate that works at + + align:start position:0% +gives us a better estimate that works at + + + align:start position:0% +gives us a better estimate that works at +both the high and the low end + + align:start position:0% + + + + align:start position:0% + +and that's what you see here so + + align:start position:0% +and that's what you see here so + + + align:start position:0% +and that's what you see here so +basically we haven't changed the + + align:start position:0% +basically we haven't changed the + + + align:start position:0% +basically we haven't changed the +correction hasn't changed here but we've + + align:start position:0% +correction hasn't changed here but we've + + + align:start position:0% +correction hasn't changed here but we've +lowered we've downgraded these lower + + align:start position:0% +lowered we've downgraded these lower + + + align:start position:0% +lowered we've downgraded these lower +ones and essentially what we're doing is + + align:start position:0% +ones and essentially what we're doing is + + + align:start position:0% +ones and essentially what we're doing is +instead of just using the average as the + + align:start position:0% +instead of just using the average as the + + + align:start position:0% +instead of just using the average as the +statistic we're using the median so + + align:start position:0% +statistic we're using the median so + + + align:start position:0% +statistic we're using the median so +we're using essentially a quantile based + + align:start position:0% +we're using essentially a quantile based + + + align:start position:0% +we're using essentially a quantile based +uh uh uh uh correction here 50th percent + + align:start position:0% +uh uh uh uh correction here 50th percent + + + align:start position:0% +uh uh uh uh correction here 50th percent +quantile based correction here and that + + align:start position:0% +quantile based correction here and that + + + align:start position:0% +quantile based correction here and that +causes us to lower the estimates of + + align:start position:0% +causes us to lower the estimates of + + + align:start position:0% +causes us to lower the estimates of +these uh vertices and so there would be + + align:start position:0% +these uh vertices and so there would be + + + align:start position:0% +these uh vertices and so there would be +a better estimate in terms allow you to + + align:start position:0% +a better estimate in terms allow you to + + + align:start position:0% +a better estimate in terms allow you to +do do the sampling of that all right + + align:start position:0% +do do the sampling of that all right + + + align:start position:0% +do do the sampling of that all right +very + + align:start position:0% + + + + align:start position:0% + +good and our final demo + + align:start position:0% + + + + align:start position:0% + +all righty so now what we're doing is + + align:start position:0% +all righty so now what we're doing is + + + align:start position:0% +all righty so now what we're doing is +doing power law fitting okay and so we + + align:start position:0% +doing power law fitting okay and so we + + + align:start position:0% +doing power law fitting okay and so we +have the routines for doing that so + + align:start position:0% +have the routines for doing that so + + + align:start position:0% +have the routines for doing that so +again here's our distribution it's a a + + align:start position:0% +again here's our distribution it's a a + + + align:start position:0% +again here's our distribution it's a a +power law of 1.3 we've set dmax to be + + align:start position:0% +power law of 1.3 we've set dmax to be + + + align:start position:0% +power law of 1.3 we've set dmax to be +2,000 and about 60-ish bins we create + + align:start position:0% +2,000 and about 60-ish bins we create + + + align:start position:0% +2,000 and about 60-ish bins we create +our power law distribution it has 50,000 + + align:start position:0% +our power law distribution it has 50,000 + + + align:start position:0% +our power law distribution it has 50,000 +vertices 329,000 edges ratio so same as + + align:start position:0% +vertices 329,000 edges ratio so same as + + + align:start position:0% +vertices 329,000 edges ratio so same as +the one we did before + + align:start position:0% +the one we did before + + + align:start position:0% +the one we did before +we're going to make it + + align:start position:0% +we're going to make it + + + align:start position:0% +we're going to make it +undirected undirected unweighted + + align:start position:0% +undirected undirected unweighted + + + align:start position:0% +undirected undirected unweighted +undirected unweighted no self Loops so + + align:start position:0% +undirected unweighted no self Loops so + + + align:start position:0% +undirected unweighted no self Loops so +sort of standard Corrections that we + + align:start position:0% +sort of standard Corrections that we + + + align:start position:0% +sort of standard Corrections that we +do going to compute the degree + + align:start position:0% +do going to compute the degree + + + align:start position:0% +do going to compute the degree +distribution of that data and plot it or + + align:start position:0% +distribution of that data and plot it or + + + align:start position:0% +distribution of that data and plot it or +actually it there and now I'm going to + + align:start position:0% +actually it there and now I'm going to + + + align:start position:0% +actually it there and now I'm going to +then we have this function called Power + + align:start position:0% +then we have this function called Power + + + align:start position:0% +then we have this function called Power +law fit so if I compute this is I'm + + align:start position:0% +law fit so if I compute this is I'm + + + align:start position:0% +law fit so if I compute this is I'm +going to compute so I compute the degree + + align:start position:0% +going to compute so I compute the degree + + + align:start position:0% +going to compute so I compute the degree +distribution so have this function + + align:start position:0% +distribution so have this function + + + align:start position:0% +distribution so have this function +called outdegree which just gives us the + + align:start position:0% +called outdegree which just gives us the + + + align:start position:0% +called outdegree which just gives us the +distribution and I can find essentially + + align:start position:0% +distribution and I can find essentially + + + align:start position:0% +distribution and I can find essentially +the uh the number of values with the one + + align:start position:0% +the uh the number of values with the one + + + align:start position:0% +the uh the number of values with the one +and the one that are maximum so get our + + align:start position:0% +and the one that are maximum so get our + + + align:start position:0% +and the one that are maximum so get our +this is estimating our poor man's slope + + align:start position:0% +this is estimating our poor man's slope + + + align:start position:0% +this is estimating our poor man's slope +so we're Computing the slope we're + + align:start position:0% +so we're Computing the slope we're + + + align:start position:0% +so we're Computing the slope we're +counting the total number of of edges + + align:start position:0% +counting the total number of of edges + + + align:start position:0% +counting the total number of of edges +here and then we have this function + + align:start position:0% +here and then we have this function + + + align:start position:0% +here and then we have this function +called Power law fit basically we can + + align:start position:0% +called Power law fit basically we can + + + align:start position:0% +called Power law fit basically we can +plug in what the estimated Alpha is what + + align:start position:0% +plug in what the estimated Alpha is what + + + align:start position:0% +plug in what the estimated Alpha is what +the number of vertices is and the number + + align:start position:0% +the number of vertices is and the number + + + align:start position:0% +the number of vertices is and the number +of edges is to find our best fit + + align:start position:0% +of edges is to find our best fit + + + align:start position:0% +of edges is to find our best fit +distribution so this basically vers + + align:start position:0% +distribution so this basically vers + + + align:start position:0% +distribution so this basically vers +those two those formulas I showed you + + align:start position:0% +those two those formulas I showed you + + + align:start position:0% +those two those formulas I showed you +which is given a degree distribution + + align:start position:0% +which is given a degree distribution + + + align:start position:0% +which is given a degree distribution +that sums to a particular number of ver + + align:start position:0% +that sums to a particular number of ver + + + align:start position:0% +that sums to a particular number of ver +vertices and sums to a particular number + + align:start position:0% +vertices and sums to a particular number + + + align:start position:0% +vertices and sums to a particular number +of edges can you give me a new dmax and + + align:start position:0% +of edges can you give me a new dmax and + + + align:start position:0% +of edges can you give me a new dmax and +a new ND these sort of parameters that + + align:start position:0% +a new ND these sort of parameters that + + + align:start position:0% +a new ND these sort of parameters that +don't really have as much meaning to uh + + align:start position:0% +don't really have as much meaning to uh + + + align:start position:0% +don't really have as much meaning to uh +to to do that and so uh basically we use + + align:start position:0% +to to do that and so uh basically we use + + + align:start position:0% +to to do that and so uh basically we use +essentially a combination of three + + align:start position:0% +essentially a combination of three + + + align:start position:0% +essentially a combination of three +different techniques here because this + + align:start position:0% +different techniques here because this + + + align:start position:0% +different techniques here because this +is so nonlinear here and there's this + + align:start position:0% +is so nonlinear here and there's this + + + align:start position:0% +is so nonlinear here and there's this +basically remember I talked about + + align:start position:0% +basically remember I talked about + + + align:start position:0% +basically remember I talked about +integer bins and logarithmic bins well + + align:start position:0% +integer bins and logarithmic bins well + + + align:start position:0% +integer bins and logarithmic bins well +if you look at that plot it showed there + + align:start position:0% +if you look at that plot it showed there + + + align:start position:0% +if you look at that plot it showed there +was that sort of bending it's a very + + align:start position:0% +was that sort of bending it's a very + + + align:start position:0% +was that sort of bending it's a very +sort of nasty manifold uh the the + + align:start position:0% +sort of nasty manifold uh the the + + + align:start position:0% +sort of nasty manifold uh the the +surface of this function and it has a + + align:start position:0% +surface of this function and it has a + + + align:start position:0% +surface of this function and it has a +continuous part and a discrete part so + + align:start position:0% +continuous part and a discrete part so + + + align:start position:0% +continuous part and a discrete part so +what we do here is we do a essentially a + + align:start position:0% +what we do here is we do a essentially a + + + align:start position:0% +what we do here is we do a essentially a +a sampled search where we kind of + + align:start position:0% +a sampled search where we kind of + + + align:start position:0% +a sampled search where we kind of +randomly sample looking for a location + + align:start position:0% +randomly sample looking for a location + + + align:start position:0% +randomly sample looking for a location +we do a heuristic search which is sort + + align:start position:0% +we do a heuristic search which is sort + + + align:start position:0% +we do a heuristic search which is sort +of a kind of a simulated kneeling search + + align:start position:0% +of a kind of a simulated kneeling search + + + align:start position:0% +of a kind of a simulated kneeling search +and we also use bren's linear uh uh + + align:start position:0% +and we also use bren's linear uh uh + + + align:start position:0% +and we also use bren's linear uh uh +essentially A variation of Newton's + + align:start position:0% +essentially A variation of Newton's + + + align:start position:0% +essentially A variation of Newton's +method to all try and find the best set + + align:start position:0% +method to all try and find the best set + + + align:start position:0% +method to all try and find the best set +of parameters that will fit this data we + + align:start position:0% +of parameters that will fit this data we + + + align:start position:0% +of parameters that will fit this data we +never we rarely get an exact match but + + align:start position:0% +never we rarely get an exact match but + + + align:start position:0% +never we rarely get an exact match but +you can see here it's choosing different + + align:start position:0% +you can see here it's choosing different + + + align:start position:0% +you can see here it's choosing different +ones and this gives you the kind of how + + align:start position:0% +ones and this gives you the kind of how + + + align:start position:0% +ones and this gives you the kind of how +it's doing from the sample search this + + align:start position:0% +it's doing from the sample search this + + + align:start position:0% +it's doing from the sample search this +shows you the number of vertices and the + + align:start position:0% +shows you the number of vertices and the + + + align:start position:0% +shows you the number of vertices and the +number of edges it was able to achieve + + align:start position:0% +number of edges it was able to achieve + + + align:start position:0% +number of edges it was able to achieve +theistic search you know didn't do very + + align:start position:0% +theistic search you know didn't do very + + + align:start position:0% +theistic search you know didn't do very +well at all and then the Bren search did + + align:start position:0% +well at all and then the Bren search did + + + align:start position:0% +well at all and then the Bren search did +a pretty good job you know it and and it + + align:start position:0% +a pretty good job you know it and and it + + + align:start position:0% +a pretty good job you know it and and it +got got us a pretty so it Choice first + + align:start position:0% +got got us a pretty so it Choice first + + + align:start position:0% +got got us a pretty so it Choice first +thing it Choice it it actually actually + + align:start position:0% +thing it Choice it it actually actually + + + align:start position:0% +thing it Choice it it actually actually +it ended up comparing all of these and + + align:start position:0% +it ended up comparing all of these and + + + align:start position:0% +it ended up comparing all of these and +it ended up choosing the uh the sample + + align:start position:0% +it ended up choosing the uh the sample + + + align:start position:0% +it ended up choosing the uh the sample +search uh this one this first one it did + + align:start position:0% +search uh this one this first one it did + + + align:start position:0% +search uh this one this first one it did +it liked that best of all + + align:start position:0% +it liked that best of all + + + align:start position:0% +it liked that best of all +so we look at that + + align:start position:0% +so we look at that + + + align:start position:0% +so we look at that +here so figure two just was the original + + align:start position:0% +here so figure two just was the original + + + align:start position:0% +here so figure two just was the original +original + + align:start position:0% +original + + + align:start position:0% +original +data figure one shows you the manifold + + align:start position:0% +data figure one shows you the manifold + + + align:start position:0% +data figure one shows you the manifold +of this space and so plotted in this + + align:start position:0% +of this space and so plotted in this + + + align:start position:0% +of this space and so plotted in this +this coordinate system of n versus m the + + align:start position:0% +this coordinate system of n versus m the + + + align:start position:0% +this coordinate system of n versus m the +dot is the dot that it found it's + + align:start position:0% +dot is the dot that it found it's + + + align:start position:0% +dot is the dot that it found it's +actually here in this type in this tping + + align:start position:0% +actually here in this type in this tping + + + align:start position:0% +actually here in this type in this tping +these lines show the boundaries but you + + align:start position:0% +these lines show the boundaries but you + + + align:start position:0% +these lines show the boundaries but you +can see this sort of very nonlinear + + align:start position:0% +can see this sort of very nonlinear + + + align:start position:0% +can see this sort of very nonlinear +manifold here this is sort of the + + align:start position:0% +manifold here this is sort of the + + + align:start position:0% +manifold here this is sort of the +continuous regime this is the energer + + align:start position:0% +continuous regime this is the energer + + + align:start position:0% +continuous regime this is the energer +regime it cusps right at the transition + + align:start position:0% +regime it cusps right at the transition + + + align:start position:0% +regime it cusps right at the transition +again a very nasty function to try and + + align:start position:0% +again a very nasty function to try and + + + align:start position:0% +again a very nasty function to try and +uh try and invert and which is why we + + align:start position:0% +uh try and invert and which is why we + + + align:start position:0% +uh try and invert and which is why we +used all those different techniques to + + align:start position:0% +used all those different techniques to + + + align:start position:0% +used all those different techniques to +invert + + align:start position:0% + + + + align:start position:0% + +it and then so we did figure two and + + align:start position:0% +it and then so we did figure two and + + + align:start position:0% +it and then so we did figure two and +then figure three shows the results so + + align:start position:0% +then figure three shows the results so + + + align:start position:0% +then figure three shows the results so +um this black line shows the original + + align:start position:0% +um this black line shows the original + + + align:start position:0% +um this black line shows the original +model input that we provided so that was + + align:start position:0% +model input that we provided so that was + + + align:start position:0% +model input that we provided so that was +the the true model the circle shows the + + align:start position:0% +the the true model the circle shows the + + + align:start position:0% +the the true model the circle shows the +data after it was transformed we made it + + align:start position:0% +data after it was transformed we made it + + + align:start position:0% +data after it was transformed we made it +undirected unweighted with no self Loops + + align:start position:0% +undirected unweighted with no self Loops + + + align:start position:0% +undirected unweighted with no self Loops +that's this Alpha is this is our our + + align:start position:0% +that's this Alpha is this is our our + + + align:start position:0% +that's this Alpha is this is our our +poor man's Alpha which you can see is + + align:start position:0% +poor man's Alpha which you can see is + + + align:start position:0% +poor man's Alpha which you can see is +almost identical to the original model + + align:start position:0% +almost identical to the original model + + + align:start position:0% +almost identical to the original model +so the even you poor man's Alpha does a + + align:start position:0% +so the even you poor man's Alpha does a + + + align:start position:0% +so the even you poor man's Alpha does a +very good job of fitting in this case + + align:start position:0% +very good job of fitting in this case + + + align:start position:0% +very good job of fitting in this case +this shows the triangle shows the model + + align:start position:0% +this shows the triangle shows the model + + + align:start position:0% +this shows the triangle shows the model +fit so when we fit the data we came up + + align:start position:0% +fit so when we fit the data we came up + + + align:start position:0% +fit so when we fit the data we came up +with that best fit it CHS and we then + + align:start position:0% +with that best fit it CHS and we then + + + align:start position:0% +with that best fit it CHS and we then +created a new distribution this is what + + align:start position:0% +created a new distribution this is what + + + align:start position:0% +created a new distribution this is what +it looked like and then the plus sign + + align:start position:0% +it looked like and then the plus sign + + + align:start position:0% +it looked like and then the plus sign +shows us rebinning that data onto the + + align:start position:0% +shows us rebinning that data onto the + + + align:start position:0% +shows us rebinning that data onto the +bins from the model and you see that + + align:start position:0% +bins from the model and you see that + + + align:start position:0% +bins from the model and you see that +we've done a very nice job of recovering + + align:start position:0% +we've done a very nice job of recovering + + + align:start position:0% +we've done a very nice job of recovering +the original Power law distribution + + align:start position:0% +the original Power law distribution + + + align:start position:0% +the original Power law distribution +after even after we did that Distortion + + align:start position:0% +after even after we did that Distortion + + + align:start position:0% +after even after we did that Distortion +so again that sort of is the last + + align:start position:0% +so again that sort of is the last + + + align:start position:0% +so again that sort of is the last +example so I want to thank you and then + + align:start position:0% +example so I want to thank you and then + + + align:start position:0% +example so I want to thank you and then +for the homework um a lot of you did + + align:start position:0% +for the homework um a lot of you did + + + align:start position:0% +for the homework um a lot of you did +homework to which is great uh I think + + align:start position:0% +homework to which is great uh I think + + + align:start position:0% +homework to which is great uh I think +homework three wasn't such a great hit + + align:start position:0% +homework three wasn't such a great hit + + + align:start position:0% +homework three wasn't such a great hit +I'm going to definitely rethink that one + + align:start position:0% +I'm going to definitely rethink that one + + + align:start position:0% +I'm going to definitely rethink that one +um but the next homework does not + + align:start position:0% +um but the next homework does not + + + align:start position:0% +um but the next homework does not +require you to have done homework 3 if + + align:start position:0% +require you to have done homework 3 if + + + align:start position:0% +require you to have done homework 3 if +you did homework 2 um basically it's + + align:start position:0% +you did homework 2 um basically it's + + + align:start position:0% +you did homework 2 um basically it's +just saying computed de degree + + align:start position:0% +just saying computed de degree + + + align:start position:0% +just saying computed de degree +distribution okay and in fact you don't + + align:start position:0% +distribution okay and in fact you don't + + + align:start position:0% +distribution okay and in fact you don't +even need to have done homework 2 just + + align:start position:0% +even need to have done homework 2 just + + + align:start position:0% +even need to have done homework 2 just +you can compute a degree Distribution on + + align:start position:0% +you can compute a degree Distribution on + + + align:start position:0% +you can compute a degree Distribution on +your homework 2 + + align:start position:0% +your homework 2 + + + align:start position:0% +your homework 2 +or you can compute a degree Distribution + + align:start position:0% +or you can compute a degree Distribution + + + align:start position:0% +or you can compute a degree Distribution +on any data set for example today is + + align:start position:0% +on any data set for example today is + + + align:start position:0% +on any data set for example today is +Halloween if you go trick- or retreating + + align:start position:0% +Halloween if you go trick- or retreating + + + align:start position:0% +Halloween if you go trick- or retreating +with your with with somebody yourself + + align:start position:0% +with your with with somebody yourself + + + align:start position:0% +with your with with somebody yourself +your children somebody else's children + + align:start position:0% +your children somebody else's children + + + align:start position:0% +your children somebody else's children +um you can uh you can uh maybe uh email + + align:start position:0% +um you can uh you can uh maybe uh email + + + align:start position:0% +um you can uh you can uh maybe uh email +me with the you know the histogram of + + align:start position:0% +me with the you know the histogram of + + + align:start position:0% +me with the you know the histogram of +your candy and plot it on a degree + + align:start position:0% +your candy and plot it on a degree + + + align:start position:0% +your candy and plot it on a degree +distribution uh and maybe compute the + + align:start position:0% +distribution uh and maybe compute the + + + align:start position:0% +distribution uh and maybe compute the +the poor man's Alpha coefficient from + + align:start position:0% +the poor man's Alpha coefficient from + + + align:start position:0% +the poor man's Alpha coefficient from +that and the other you know coefficients + + align:start position:0% +that and the other you know coefficients + + + align:start position:0% +that and the other you know coefficients +from that would be a fun exercise to do + + align:start position:0% +from that would be a fun exercise to do + + + align:start position:0% +from that would be a fun exercise to do +so that'll be the next homework I'll + + align:start position:0% +so that'll be the next homework I'll + + + align:start position:0% +so that'll be the next homework I'll +email that out in the next couple of + + align:start position:0% +email that out in the next couple of + + + align:start position:0% +email that out in the next couple of +days and so um uh look forward again if + + align:start position:0% +days and so um uh look forward again if + + + align:start position:0% +days and so um uh look forward again if +you send me the homework prior to um to + + align:start position:0% +you send me the homework prior to um to + + + align:start position:0% +you send me the homework prior to um to +next uh actually oh just reminder no + + align:start position:0% +next uh actually oh just reminder no + + + align:start position:0% +next uh actually oh just reminder no +class next week no class next week this + + align:start position:0% +class next week no class next week this + + + align:start position:0% +class next week no class next week this +room is being taken uh so but again if + + align:start position:0% +room is being taken uh so but again if + + + align:start position:0% +room is being taken uh so but again if +you email me the homework prior to this + + align:start position:0% +you email me the homework prior to this + + + align:start position:0% +you email me the homework prior to this +time next week I will give you feedback + + align:start position:0% +time next week I will give you feedback + + + align:start position:0% +time next week I will give you feedback +on it um can still send me the homework + + align:start position:0% +on it um can still send me the homework + + + align:start position:0% +on it um can still send me the homework +after that I just won't give you any + + align:start position:0% +after that I just won't give you any + + + align:start position:0% +after that I just won't give you any +feedback on it so thank you again and um + + align:start position:0% +feedback on it so thank you again and um + + + align:start position:0% +feedback on it so thank you again and um +um look forward to seeing you in 2 weeks \ No newline at end of file diff --git a/RVWsRDF0-p0.txt b/RVWsRDF0-p0.txt new file mode 100644 index 0000000000000000000000000000000000000000..b18730f8de89c0fac6472cfe6750c2a8f189ffdd --- /dev/null +++ b/RVWsRDF0-p0.txt @@ -0,0 +1,443 @@ +align:start position:0% + +I was just + + align:start position:0% + + + + align:start position:0% + +thinking you know we're talking about + + align:start position:0% +thinking you know we're talking about + + + align:start position:0% +thinking you know we're talking about +cities and having + + align:start position:0% +cities and having + + + align:start position:0% +cities and having +problems how long have cities + + align:start position:0% +problems how long have cities + + + align:start position:0% +problems how long have cities +existed including the first settl + + align:start position:0% +existed including the first settl + + + align:start position:0% +existed including the first settl +permanent settlement say Jericho 8,000 + + align:start position:0% +permanent settlement say Jericho 8,000 + + + align:start position:0% +permanent settlement say Jericho 8,000 +before Christ how many years do that to + + align:start position:0% +before Christ how many years do that to + + + align:start position:0% +before Christ how many years do that to +today + + align:start position:0% +today + + + align:start position:0% +today +20,000 + + align:start position:0% + + + + align:start position:0% + +years what are we now + + align:start position:0% + + + + align:start position:0% + +2,200 added to + + align:start position:0% +2,200 added to + + + align:start position:0% +2,200 added to +8,000 10,000 years it took 2.6 million + + align:start position:0% +8,000 10,000 years it took 2.6 million + + + align:start position:0% +8,000 10,000 years it took 2.6 million +years for human beings to develop a + + align:start position:0% +years for human beings to develop a + + + align:start position:0% +years for human beings to develop a +brain large enough to to + + align:start position:0% + + + + align:start position:0% + +think and we're talking about + + align:start position:0% +think and we're talking about + + + align:start position:0% +think and we're talking about +12,000 years + + align:start position:0% +12,000 years + + + align:start position:0% +12,000 years +which which was nothing in + + align:start position:0% +which which was nothing in + + + align:start position:0% +which which was nothing in +time and we expecting perfect answers to + + align:start position:0% +time and we expecting perfect answers to + + + align:start position:0% +time and we expecting perfect answers to +communal + + align:start position:0% + + + + align:start position:0% + +settlements so + + align:start position:0% + + + + align:start position:0% + +relax we + + align:start position:0% +relax we + + + align:start position:0% +relax we +teach I say this because I'm an + + align:start position:0% +teach I say this because I'm an + + + align:start position:0% +teach I say this because I'm an +architect and have taught Design Studios + + align:start position:0% +architect and have taught Design Studios + + + align:start position:0% +architect and have taught Design Studios +endlessly we tend to idealize the world + + align:start position:0% +endlessly we tend to idealize the world + + + align:start position:0% +endlessly we tend to idealize the world +world that we and smooth the world + + align:start position:0% + + + + align:start position:0% + +around I remember when I worked for on + + align:start position:0% +around I remember when I worked for on + + + align:start position:0% +around I remember when I worked for on +the image of the city research book with + + align:start position:0% +the image of the city research book with + + + align:start position:0% +the image of the city research book with +Kevin Lynch K Jerry keish his compatriot + + align:start position:0% +Kevin Lynch K Jerry keish his compatriot + + + align:start position:0% +Kevin Lynch K Jerry keish his compatriot +asked me to take a walk down Washington + + align:start position:0% +asked me to take a walk down Washington + + + align:start position:0% +asked me to take a walk down Washington +Street on a busy day and note just note + + align:start position:0% +Street on a busy day and note just note + + + align:start position:0% +Street on a busy day and note just note +all the things that I + + align:start position:0% + + + + align:start position:0% + +saw I made the tabulation of all the + + align:start position:0% +saw I made the tabulation of all the + + + align:start position:0% +saw I made the tabulation of all the +things that I saw where the Sun was + + align:start position:0% +things that I saw where the Sun was + + + align:start position:0% +things that I saw where the Sun was +shining what noise there was what signs + + align:start position:0% +shining what noise there was what signs + + + align:start position:0% +shining what noise there was what signs +there were and so on and I came up and + + align:start position:0% +there were and so on and I came up and + + + align:start position:0% +there were and so on and I came up and +presented my work and said this is such + + align:start position:0% +presented my work and said this is such + + + align:start position:0% +presented my work and said this is such +an unbelievably confused Washington + + align:start position:0% +an unbelievably confused Washington + + + align:start position:0% +an unbelievably confused Washington +Street I don't know how anybody makes + + align:start position:0% +Street I don't know how anybody makes + + + align:start position:0% +Street I don't know how anybody makes +sense of + + align:start position:0% +sense of + + + align:start position:0% +sense of +it because at that time all Urban Design + + align:start position:0% +it because at that time all Urban Design + + + align:start position:0% +it because at that time all Urban Design +was was Victor gruen's work and how to + + align:start position:0% +was was Victor gruen's work and how to + + + align:start position:0% +was was Victor gruen's work and how to +make use modernism to cleans up conflict + + align:start position:0% +make use modernism to cleans up conflict + + + align:start position:0% +make use modernism to cleans up conflict +shopping centers had unified sign post + + align:start position:0% +shopping centers had unified sign post + + + align:start position:0% +shopping centers had unified sign post +control and uh here I was trying to say + + align:start position:0% +control and uh here I was trying to say + + + align:start position:0% +control and uh here I was trying to say +the real world is infinitely complex and + + align:start position:0% +the real world is infinitely complex and + + + align:start position:0% +the real world is infinitely complex and +yet because we have 10 to the 12 + + align:start position:0% +yet because we have 10 to the 12 + + + align:start position:0% +yet because we have 10 to the 12 +neurons in our brain each connecting to + + align:start position:0% +neurons in our brain each connecting to + + + align:start position:0% +neurons in our brain each connecting to +5,000 other sites we have the + + align:start position:0% +5,000 other sites we have the + + + align:start position:0% +5,000 other sites we have the +electricity electronic system which can + + align:start position:0% +electricity electronic system which can + + + align:start position:0% +electricity electronic system which can +manage such complexity + + align:start position:0% + + + + align:start position:0% + +I think it's a message worth + + align:start position:0% + + + + align:start position:0% + +remembering + + align:start position:0% + + + + align:start position:0% + +maybe it'll become much clearer but I + + align:start position:0% +maybe it'll become much clearer but I + + + align:start position:0% +maybe it'll become much clearer but I +think working as you do as an urban + + align:start position:0% +think working as you do as an urban + + + align:start position:0% +think working as you do as an urban +designer in the midst of a dialectic of + + align:start position:0% +designer in the midst of a dialectic of + + + align:start position:0% +designer in the midst of a dialectic of +opposites is an intelligent place to be \ No newline at end of file diff --git a/RbAjBxvCsAU.txt b/RbAjBxvCsAU.txt new file mode 100644 index 0000000000000000000000000000000000000000..17dbbf7db204322638d7a1a808913527e6bee6dc --- /dev/null +++ b/RbAjBxvCsAU.txt @@ -0,0 +1,13864 @@ +align:start position:0% + +okay good + + align:start position:0% +okay good + + + align:start position:0% +okay good +afternoon here we + + align:start position:0% +afternoon here we + + + align:start position:0% +afternoon here we +are March 19 lecture + + align:start position:0% + + + + align:start position:0% + + + align:start position:0% + + + align:start position:0% +we are still in the process of studying + + align:start position:0% +we are still in the process of studying + + + align:start position:0% +we are still in the process of studying +mixtures the one wonderful word of + + align:start position:0% + + + + align:start position:0% + +mixtures and so let me just uh + + align:start position:0% +mixtures and so let me just uh + + + align:start position:0% +mixtures and so let me just uh +briefly see where we + + align:start position:0% +briefly see where we + + + align:start position:0% +briefly see where we +are you remember that we discussed + + align:start position:0% +are you remember that we discussed + + + align:start position:0% +are you remember that we discussed +um the properties of isobaric mixing + + align:start position:0% +um the properties of isobaric mixing + + + align:start position:0% +um the properties of isobaric mixing +which + + align:start position:0% +which + + + align:start position:0% +which +are uh measurable properties that allow + + align:start position:0% +are uh measurable properties that allow + + + align:start position:0% +are uh measurable properties that allow +us to + + align:start position:0% +us to + + + align:start position:0% +us to +infer uh the chemical potentials + + align:start position:0% +infer uh the chemical potentials + + + align:start position:0% +infer uh the chemical potentials +thanks to this uh expression + + align:start position:0% + + + + align:start position:0% + +here we + + align:start position:0% +here we + + + align:start position:0% +here we +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +discussed the intermolecular forces + + align:start position:0% +discussed the intermolecular forces + + + align:start position:0% +discussed the intermolecular forces +between + + align:start position:0% + + + + align:start position:0% + +molecules and for example the fact that + + align:start position:0% +molecules and for example the fact that + + + align:start position:0% +molecules and for example the fact that +in the gas or ideal gas + + align:start position:0% +in the gas or ideal gas + + + align:start position:0% +in the gas or ideal gas +regime + + align:start position:0% +regime + + + align:start position:0% +regime +molecules spend most most of their time + + align:start position:0% +molecules spend most most of their time + + + align:start position:0% +molecules spend most most of their time +far away from each other in spite of + + align:start position:0% +far away from each other in spite of + + + align:start position:0% +far away from each other in spite of +having an enormous amount of collisions + + align:start position:0% +having an enormous amount of collisions + + + align:start position:0% +having an enormous amount of collisions +per + + align:start position:0% + + + + align:start position:0% + +second during which they do get + + align:start position:0% +second during which they do get + + + align:start position:0% +second during which they do get +close but the time they spend close is + + align:start position:0% +close but the time they spend close is + + + align:start position:0% +close but the time they spend close is +small with respect + + align:start position:0% +small with respect + + + align:start position:0% +small with respect +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +to uh the average and + + align:start position:0% +to uh the average and + + + align:start position:0% +to uh the average and +so since the properties are determined + + align:start position:0% +so since the properties are determined + + + align:start position:0% +so since the properties are determined +uh by the + + align:start position:0% + + + + align:start position:0% + +average the effect of when of the + + align:start position:0% +average the effect of when of the + + + align:start position:0% +average the effect of when of the +intermolecular reaction + + align:start position:0% +intermolecular reaction + + + align:start position:0% +intermolecular reaction +interactions uh is + + align:start position:0% +interactions uh is + + + align:start position:0% +interactions uh is +relatively + + align:start position:0% +relatively + + + align:start position:0% +relatively +negligible and that's the ideal gas for + + align:start position:0% +negligible and that's the ideal gas for + + + align:start position:0% +negligible and that's the ideal gas for +regime we will see more about + + align:start position:0% +regime we will see more about + + + align:start position:0% +regime we will see more about +that uh + + align:start position:0% +that uh + + + align:start position:0% +that uh +today uh from another point of view + + align:start position:0% +today uh from another point of view + + + align:start position:0% +today uh from another point of view +which which uh we will see in a + + align:start position:0% + + + + align:start position:0% + +moment we introduced a first ideal + + align:start position:0% +moment we introduced a first ideal + + + align:start position:0% +moment we introduced a first ideal +Behavior Uh model based on this idea of + + align:start position:0% +Behavior Uh model based on this idea of + + + align:start position:0% +Behavior Uh model based on this idea of +uh particles not + + align:start position:0% +uh particles not + + + align:start position:0% +uh particles not +interacting which is the ideal Gibs + + align:start position:0% +interacting which is the ideal Gibs + + + align:start position:0% +interacting which is the ideal Gibs +Dalton mixture + + align:start position:0% +Dalton mixture + + + align:start position:0% +Dalton mixture +model in which as you remember the idea + + align:start position:0% +model in which as you remember the idea + + + align:start position:0% +model in which as you remember the idea +is that that we uh represent the the + + align:start position:0% +is that that we uh represent the the + + + align:start position:0% +is that that we uh represent the the +properties of the + + align:start position:0% +properties of the + + + align:start position:0% +properties of the +mixture as + + align:start position:0% +mixture as + + + align:start position:0% +mixture as +equivalent to the properties of a + + align:start position:0% +equivalent to the properties of a + + + align:start position:0% +equivalent to the properties of a +composite system in + + align:start position:0% +composite system in + + + align:start position:0% +composite system in +which the various components are + + align:start position:0% +which the various components are + + + align:start position:0% +which the various components are +separate they occupy the same volum they + + align:start position:0% +separate they occupy the same volum they + + + align:start position:0% +separate they occupy the same volum they +are the same temperature and they are at + + align:start position:0% +are the same temperature and they are at + + + align:start position:0% +are the same temperature and they are at +the partial + + align:start position:0% + + + + align:start position:0% + +pressure according to this uh model if + + align:start position:0% +pressure according to this uh model if + + + align:start position:0% +pressure according to this uh model if +we + + align:start position:0% +we + + + align:start position:0% +we +if each of the substances + + align:start position:0% +if each of the substances + + + align:start position:0% +if each of the substances +behaves as an ideal gas so obeys the + + align:start position:0% +behaves as an ideal gas so obeys the + + + align:start position:0% +behaves as an ideal gas so obeys the +ideal gas PV equals RT + + align:start position:0% +ideal gas PV equals RT + + + align:start position:0% +ideal gas PV equals RT +um equation of + + align:start position:0% +um equation of + + + align:start position:0% +um equation of +State we found that the partial + + align:start position:0% +State we found that the partial + + + align:start position:0% +State we found that the partial +properties add up to the pressure of the + + align:start position:0% +properties add up to the pressure of the + + + align:start position:0% +properties add up to the pressure of the +mixture that's D dton law this + + align:start position:0% +mixture that's D dton law this + + + align:start position:0% +mixture that's D dton law this +here and the partial pressures are given + + align:start position:0% +here and the partial pressures are given + + + align:start position:0% +here and the partial pressures are given +by the pressure of the mixture times the + + align:start position:0% +by the pressure of the mixture times the + + + align:start position:0% +by the pressure of the mixture times the +mole + + align:start position:0% +mole + + + align:start position:0% +mole +fraction plus the chemical potential of + + align:start position:0% +fraction plus the chemical potential of + + + align:start position:0% +fraction plus the chemical potential of +the components in the mixture of each + + align:start position:0% +the components in the mixture of each + + + align:start position:0% +the components in the mixture of each +component is equal + + align:start position:0% +component is equal + + + align:start position:0% +component is equal +to this important expression that gives + + align:start position:0% +to this important expression that gives + + + align:start position:0% +to this important expression that gives +the that is the sum of the chemical + + align:start position:0% +the that is the sum of the chemical + + + align:start position:0% +the that is the sum of the chemical +potential of the pure component at the + + align:start position:0% +potential of the pure component at the + + + align:start position:0% +potential of the pure component at the +same temperature and pressure of the + + align:start position:0% +same temperature and pressure of the + + + align:start position:0% +same temperature and pressure of the +mixture plus RT the log of a mole + + align:start position:0% +mixture plus RT the log of a mole + + + align:start position:0% +mixture plus RT the log of a mole +fraction + + align:start position:0% + + + + align:start position:0% + +we + + align:start position:0% +we + + + align:start position:0% +we +then um proved also the amagat low + + align:start position:0% +then um proved also the amagat low + + + align:start position:0% +then um proved also the amagat low +additive + + align:start position:0% + + + + align:start position:0% + +volumes uh whereby an ideal gas mixture + + align:start position:0% +volumes uh whereby an ideal gas mixture + + + align:start position:0% +volumes uh whereby an ideal gas mixture +is such that uh you can also view + + align:start position:0% +is such that uh you can also view + + + align:start position:0% +is such that uh you can also view +it as a composite of separate uh pure + + align:start position:0% +it as a composite of separate uh pure + + + align:start position:0% +it as a composite of separate uh pure +gases + + align:start position:0% +gases + + + align:start position:0% +gases +each all at the same temperature + + align:start position:0% +each all at the same temperature + + + align:start position:0% +each all at the same temperature +pressure but each occupying the + + align:start position:0% +pressure but each occupying the + + + align:start position:0% +pressure but each occupying the +the uh so-called proper + + align:start position:0% + + + + align:start position:0% + +volume which is given but the volume + + align:start position:0% +volume which is given but the volume + + + align:start position:0% +volume which is given but the volume +that the they would occupy at the uh + + align:start position:0% +that the they would occupy at the uh + + + align:start position:0% +that the they would occupy at the uh +when pure in the same amount uh at the + + align:start position:0% +when pure in the same amount uh at the + + + align:start position:0% +when pure in the same amount uh at the +same temperature and + + align:start position:0% + + + + align:start position:0% + +pressure then we discussed mixing + + align:start position:0% +pressure then we discussed mixing + + + align:start position:0% +pressure then we discussed mixing +spontaneous + + align:start position:0% +spontaneous + + + align:start position:0% +spontaneous +mixing what happens when we have + + align:start position:0% +mixing what happens when we have + + + align:start position:0% +mixing what happens when we have +separate + + align:start position:0% +separate + + + align:start position:0% +separate +gases kept separate by partitions that + + align:start position:0% +gases kept separate by partitions that + + + align:start position:0% +gases kept separate by partitions that +are movable so they are all at the same + + align:start position:0% +are movable so they are all at the same + + + align:start position:0% +are movable so they are all at the same +temperature and + + align:start position:0% +temperature and + + + align:start position:0% +temperature and +pressure and without any external effect + + align:start position:0% +pressure and without any external effect + + + align:start position:0% +pressure and without any external effect +you see the weight is at the same level + + align:start position:0% +you see the weight is at the same level + + + align:start position:0% +you see the weight is at the same level +you just let them mix if you take the + + align:start position:0% +you just let them mix if you take the + + + align:start position:0% +you just let them mix if you take the +partitions away and let them + + align:start position:0% +partitions away and let them + + + align:start position:0% +partitions away and let them +mix we found that the mixing under these + + align:start position:0% +mix we found that the mixing under these + + + align:start position:0% +mix we found that the mixing under these +conditions + + align:start position:0% +conditions + + + align:start position:0% +conditions +yields the final temperature and the + + align:start position:0% +yields the final temperature and the + + + align:start position:0% +yields the final temperature and the +final pressure equal to the initial + + align:start position:0% +final pressure equal to the initial + + + align:start position:0% +final pressure equal to the initial +ones and the + + align:start position:0% +ones and the + + + align:start position:0% +ones and the +entropy increases by the so-called uh + + align:start position:0% +entropy increases by the so-called uh + + + align:start position:0% +entropy increases by the so-called uh +entropy of mixing which is given by this + + align:start position:0% +entropy of mixing which is given by this + + + align:start position:0% +entropy of mixing which is given by this +term + + align:start position:0% +term + + + align:start position:0% +term +minus the number of particles total + + align:start position:0% +minus the number of particles total + + + align:start position:0% +minus the number of particles total +number of particles the gas constant and + + align:start position:0% +number of particles the gas constant and + + + align:start position:0% +number of particles the gas constant and +the sum + + align:start position:0% +the sum + + + align:start position:0% +the sum +of Y log y + + align:start position:0% +of Y log y + + + align:start position:0% +of Y log y +so the mole fractions time the logarithm + + align:start position:0% +so the mole fractions time the logarithm + + + align:start position:0% +so the mole fractions time the logarithm +of the mole + + align:start position:0% + + + + align:start position:0% + +fractions we also noticed + + align:start position:0% +fractions we also noticed + + + align:start position:0% +fractions we also noticed +that we could have done that mixing in a + + align:start position:0% +that we could have done that mixing in a + + + align:start position:0% +that we could have done that mixing in a +better way better from the thermodynamic + + align:start position:0% +better way better from the thermodynamic + + + align:start position:0% +better way better from the thermodynamic +point of view in other words + + align:start position:0% +point of view in other words + + + align:start position:0% +point of view in other words +reversibly in a weight process and we + + align:start position:0% +reversibly in a weight process and we + + + align:start position:0% +reversibly in a weight process and we +computed how much work we could uh oh so + + align:start position:0% +computed how much work we could uh oh so + + + align:start position:0% +computed how much work we could uh oh so +that for how much weight lifting we + + align:start position:0% +that for how much weight lifting we + + + align:start position:0% +that for how much weight lifting we +could get if we did that uh uh indeed + + align:start position:0% +could get if we did that uh uh indeed + + + align:start position:0% +could get if we did that uh uh indeed +reversibly and here's the + + align:start position:0% + + + + align:start position:0% + +formula and the last thing we discussed + + align:start position:0% +formula and the last thing we discussed + + + align:start position:0% +formula and the last thing we discussed +was a + + align:start position:0% +was a + + + align:start position:0% +was a +pictorial idea + + align:start position:0% +pictorial idea + + + align:start position:0% +pictorial idea +of how + + align:start position:0% +of how + + + align:start position:0% +of how +that extraction of thetic availability + + align:start position:0% +that extraction of thetic availability + + + align:start position:0% +that extraction of thetic availability +could uh could be done if we + + align:start position:0% +could uh could be done if we + + + align:start position:0% +could uh could be done if we +have uh semi- perable + + align:start position:0% +have uh semi- perable + + + align:start position:0% +have uh semi- perable +membranes so here we picture first of + + align:start position:0% +membranes so here we picture first of + + + align:start position:0% +membranes so here we picture first of +all the idea is that when we have a a + + align:start position:0% +all the idea is that when we have a a + + + align:start position:0% +all the idea is that when we have a a +gas um confined in a volume by a + + align:start position:0% +gas um confined in a volume by a + + + align:start position:0% +gas um confined in a volume by a +partition and on the other side of the + + align:start position:0% +partition and on the other side of the + + + align:start position:0% +partition and on the other side of the +partition there is volume I mean there + + align:start position:0% +partition there is volume I mean there + + + align:start position:0% +partition there is volume I mean there +is + + align:start position:0% +is + + + align:start position:0% +is +vacuum um the pressure of + + align:start position:0% +vacuum um the pressure of + + + align:start position:0% +vacuum um the pressure of +the molecules here on the Piston will + + align:start position:0% +the molecules here on the Piston will + + + align:start position:0% +the molecules here on the Piston will +tend to push it + + align:start position:0% +tend to push it + + + align:start position:0% +tend to push it +uh uh so as to increase uh the + + align:start position:0% +uh uh so as to increase uh the + + + align:start position:0% +uh uh so as to increase uh the +volume and that will lift the weight if + + align:start position:0% +volume and that will lift the weight if + + + align:start position:0% +volume and that will lift the weight if +properly + + align:start position:0% +properly + + + align:start position:0% +properly +connected similarly the black + + align:start position:0% +connected similarly the black + + + align:start position:0% +connected similarly the black +particles now the idea here is that in + + align:start position:0% +particles now the idea here is that in + + + align:start position:0% +particles now the idea here is that in +ideal G Gibs Dalton mixture Behavior the + + align:start position:0% +ideal G Gibs Dalton mixture Behavior the + + + align:start position:0% +ideal G Gibs Dalton mixture Behavior the +particles essentially even in the + + align:start position:0% +particles essentially even in the + + + align:start position:0% +particles essentially even in the +mixture ignore each other they don't + + align:start position:0% +mixture ignore each other they don't + + + align:start position:0% +mixture ignore each other they don't +they live in the entire volume even as + + align:start position:0% +they live in the entire volume even as + + + align:start position:0% +they live in the entire volume even as +if the others weren't + + align:start position:0% +if the others weren't + + + align:start position:0% +if the others weren't +there so for the gray particles to + + align:start position:0% +there so for the gray particles to + + + align:start position:0% +there so for the gray particles to +expand to to here whether there is a the + + align:start position:0% +expand to to here whether there is a the + + + align:start position:0% +expand to to here whether there is a the +black particles or not isn't really + + align:start position:0% +black particles or not isn't really + + + align:start position:0% +black particles or not isn't really +difference + + align:start position:0% +difference + + + align:start position:0% +difference +so that is the idea that we can + + align:start position:0% +so that is the idea that we can + + + align:start position:0% +so that is the idea that we can +achieve with these semi-permeable + + align:start position:0% +achieve with these semi-permeable + + + align:start position:0% +achieve with these semi-permeable +membranes this one + + align:start position:0% +membranes this one + + + align:start position:0% +membranes this one +allows the black particles to go through + + align:start position:0% +allows the black particles to go through + + + align:start position:0% +allows the black particles to go through +but not the gray so the gray will push + + align:start position:0% +but not the gray so the gray will push + + + align:start position:0% +but not the gray so the gray will push +it to the right and pull up this weight + + align:start position:0% +it to the right and pull up this weight + + + align:start position:0% +it to the right and pull up this weight +this other membrane is + + align:start position:0% +this other membrane is + + + align:start position:0% +this other membrane is +permeable to the gray particles but not + + align:start position:0% +permeable to the gray particles but not + + + align:start position:0% +permeable to the gray particles but not +the black so the black will push it + + align:start position:0% +the black so the black will push it + + + align:start position:0% +the black so the black will push it +leftward and pull up this other + + align:start position:0% + + + + align:start position:0% + +way + + align:start position:0% + + + + align:start position:0% + +okay you asked uh do we have membranes + + align:start position:0% +okay you asked uh do we have membranes + + + align:start position:0% +okay you asked uh do we have membranes +in + + align:start position:0% +in + + + align:start position:0% +in +reality uh and yes we + + align:start position:0% + + + + align:start position:0% + +do we have uh we can manufacture them we + + align:start position:0% +do we have uh we can manufacture them we + + + align:start position:0% +do we have uh we can manufacture them we +make we make we engineer uh + + align:start position:0% +make we make we engineer uh + + + align:start position:0% +make we make we engineer uh +materials these are some YouTube videos + + align:start position:0% +materials these are some YouTube videos + + + align:start position:0% +materials these are some YouTube videos +that you may want to to go and watch I'm + + align:start position:0% +that you may want to to go and watch I'm + + + align:start position:0% +that you may want to to go and watch I'm +not doing it + + align:start position:0% +not doing it + + + align:start position:0% +not doing it +here and uh so you you can essentially + + align:start position:0% +here and uh so you you can essentially + + + align:start position:0% +here and uh so you you can essentially +have a wall of uh + + align:start position:0% +have a wall of uh + + + align:start position:0% +have a wall of uh +materials with holes and if the holes + + align:start position:0% +materials with holes and if the holes + + + align:start position:0% +materials with holes and if the holes +are the proper size they can allow the + + align:start position:0% +are the proper size they can allow the + + + align:start position:0% +are the proper size they can allow the +passage of some particles and prevent + + align:start position:0% +passage of some particles and prevent + + + align:start position:0% +passage of some particles and prevent +the particles the the other particles to + + align:start position:0% +the particles the the other particles to + + + align:start position:0% +the particles the the other particles to +to pass so that is the way we achieve a + + align:start position:0% +to pass so that is the way we achieve a + + + align:start position:0% +to pass so that is the way we achieve a +semi perable uh + + align:start position:0% +semi perable uh + + + align:start position:0% +semi perable uh +membrane in nature also in + + align:start position:0% +membrane in nature also in + + + align:start position:0% +membrane in nature also in +biology this is very important on the uh + + align:start position:0% + + + + align:start position:0% + +on the surface of + + align:start position:0% +on the surface of + + + align:start position:0% +on the surface of +cells where you may have uh not you you + + align:start position:0% +cells where you may have uh not you you + + + align:start position:0% +cells where you may have uh not you you +may have active and passive + + align:start position:0% +may have active and passive + + + align:start position:0% +may have active and passive +transport active transport is a + + align:start position:0% +transport active transport is a + + + align:start position:0% +transport active transport is a +different story because it requires some + + align:start position:0% +different story because it requires some + + + align:start position:0% +different story because it requires some +energy uh for the um particles to + + align:start position:0% +energy uh for the um particles to + + + align:start position:0% +energy uh for the um particles to +move but also there is uh passive + + align:start position:0% +move but also there is uh passive + + + align:start position:0% +move but also there is uh passive +transport and the fact that membranes + + align:start position:0% +transport and the fact that membranes + + + align:start position:0% +transport and the fact that membranes +can be changed + + align:start position:0% +can be changed + + + align:start position:0% +can be changed +uh by the the cell uh depending on its + + align:start position:0% +uh by the the cell uh depending on its + + + align:start position:0% +uh by the the cell uh depending on its +need so for example if the cell needs to + + align:start position:0% +need so for example if the cell needs to + + + align:start position:0% +need so for example if the cell needs to +eat so to speak it could open little + + align:start position:0% +eat so to speak it could open little + + + align:start position:0% +eat so to speak it could open little +holes so that the say oxygen comes + + align:start position:0% +holes so that the say oxygen comes + + + align:start position:0% +holes so that the say oxygen comes +in uh if the cell needs to uh discharge + + align:start position:0% +in uh if the cell needs to uh discharge + + + align:start position:0% +in uh if the cell needs to uh discharge +maybe CO2 then it needs to open a little + + align:start position:0% +maybe CO2 then it needs to open a little + + + align:start position:0% +maybe CO2 then it needs to open a little +bigger holes so that the molecules these + + align:start position:0% +bigger holes so that the molecules these + + + align:start position:0% +bigger holes so that the molecules these +molecules can go out + + align:start position:0% + + + + align:start position:0% + +uh I'll have another reference about U + + align:start position:0% +uh I'll have another reference about U + + + align:start position:0% +uh I'll have another reference about U +biological structures uh but I don't + + align:start position:0% +biological structures uh but I don't + + + align:start position:0% +biological structures uh but I don't +want to talk about them because I'm not + + align:start position:0% +want to talk about them because I'm not + + + align:start position:0% +want to talk about them because I'm not +at + + align:start position:0% +at + + + align:start position:0% +at +all expert on + + align:start position:0% + + + + align:start position:0% + +this but so the world is is full of + + align:start position:0% +this but so the world is is full of + + + align:start position:0% +this but so the world is is full of +membranes and we will see more in in a + + align:start position:0% +membranes and we will see more in in a + + + align:start position:0% +membranes and we will see more in in a +few + + align:start position:0% + + + + align:start position:0% + +moments now there is one uh historical + + align:start position:0% +moments now there is one uh historical + + + align:start position:0% +moments now there is one uh historical +topic that is maybe interesting just fun + + align:start position:0% +topic that is maybe interesting just fun + + + align:start position:0% +topic that is maybe interesting just fun +to uh + + align:start position:0% + + + + align:start position:0% + +discuss it's called the Gibs + + align:start position:0% + + + + align:start position:0% + +Paradox and we have the tools to Now + + align:start position:0% +Paradox and we have the tools to Now + + + align:start position:0% +Paradox and we have the tools to Now +understand what it means and essentially + + align:start position:0% +understand what it means and essentially + + + align:start position:0% +understand what it means and essentially +to resolve + + align:start position:0% +to resolve + + + align:start position:0% +to resolve +it the idea is this we just + + align:start position:0% +it the idea is this we just + + + align:start position:0% +it the idea is this we just +uh mentioned what happens when we have + + align:start position:0% +uh mentioned what happens when we have + + + align:start position:0% +uh mentioned what happens when we have +uh particles that mix so here suppose we + + align:start position:0% +uh particles that mix so here suppose we + + + align:start position:0% +uh particles that mix so here suppose we +are just a binary mixture only two types + + align:start position:0% +are just a binary mixture only two types + + + align:start position:0% +are just a binary mixture only two types +of particles the gray and the black and + + align:start position:0% +of particles the gray and the black and + + + align:start position:0% +of particles the gray and the black and +the spontaneous + + align:start position:0% +the spontaneous + + + align:start position:0% +the spontaneous +mixing occurs this + + align:start position:0% +mixing occurs this + + + align:start position:0% +mixing occurs this +way and if you compute the entropy of + + align:start position:0% +way and if you compute the entropy of + + + align:start position:0% +way and if you compute the entropy of +mixing this summation when you have only + + align:start position:0% +mixing this summation when you have only + + + align:start position:0% +mixing this summation when you have only +two uh types of particles becomes a some + + align:start position:0% +two uh types of particles becomes a some + + + align:start position:0% +two uh types of particles becomes a some +of just two terms and of course the mole + + align:start position:0% +of just two terms and of course the mole + + + align:start position:0% +of just two terms and of course the mole +fractions when you have two particles + + align:start position:0% +fractions when you have two particles + + + align:start position:0% +fractions when you have two particles +are not independent because one because + + align:start position:0% +are not independent because one because + + + align:start position:0% +are not independent because one because +they might they must add up to one so + + align:start position:0% +they might they must add up to one so + + + align:start position:0% +they might they must add up to one so +the mole fraction of the second type + + align:start position:0% +the mole fraction of the second type + + + align:start position:0% +the mole fraction of the second type +must be equal to one minus the mole + + align:start position:0% +must be equal to one minus the mole + + + align:start position:0% +must be equal to one minus the mole +fraction of the first type of + + align:start position:0% +fraction of the first type of + + + align:start position:0% +fraction of the first type of +particles in the particular case in + + align:start position:0% +particles in the particular case in + + + align:start position:0% +particles in the particular case in +which you have 50% of one and 50% of the + + align:start position:0% +which you have 50% of one and 50% of the + + + align:start position:0% +which you have 50% of one and 50% of the +other so the more fractions are 50% or 1 + + align:start position:0% +other so the more fractions are 50% or 1 + + + align:start position:0% +other so the more fractions are 50% or 1 +half this entropy of + + align:start position:0% +half this entropy of + + + align:start position:0% +half this entropy of +mixing + + align:start position:0% +mixing + + + align:start position:0% +mixing +becomes + + align:start position:0% +becomes + + + align:start position:0% +becomes +uh n R log of + + align:start position:0% + + + + align:start position:0% + +two now if we consider for example a + + align:start position:0% +two now if we consider for example a + + + align:start position:0% +two now if we consider for example a +case in which I + + align:start position:0% +case in which I + + + align:start position:0% +case in which I +have one + + align:start position:0% + + + + align:start position:0% + +particle okay if we express one particle + + align:start position:0% +particle okay if we express one particle + + + align:start position:0% +particle okay if we express one particle +in terms of + + align:start position:0% + + + + align:start position:0% + +moles uh that's one + + align:start position:0% +moles uh that's one + + + align:start position:0% +moles uh that's one +over the avado Ross + + align:start position:0% + + + + align:start position:0% + +number + + align:start position:0% + + + + align:start position:0% + +mole because in one mole you have these + + align:start position:0% +mole because in one mole you have these + + + align:start position:0% +mole because in one mole you have these +many particles + + align:start position:0% +many particles + + + align:start position:0% +many particles +6022 * 10 + + align:start position:0% +6022 * 10 + + + align:start position:0% +6022 * 10 +23rd + + align:start position:0% +23rd + + + align:start position:0% +23rd +okay so + + align:start position:0% +okay so + + + align:start position:0% +okay so +NR in that case is equal to R + + align:start position:0% +NR in that case is equal to R + + + align:start position:0% +NR in that case is equal to R +over the avocados number + + align:start position:0% +over the avocados number + + + align:start position:0% +over the avocados number +and this is called the boltzman + + align:start position:0% + + + + align:start position:0% + +constant which is one of the physical + + align:start position:0% +constant which is one of the physical + + + align:start position:0% +constant which is one of the physical +constants so if we uh suppose + + align:start position:0% + + + + align:start position:0% + +here uh we have + + align:start position:0% +here uh we have + + + align:start position:0% +here uh we have +uh + + align:start position:0% +uh + + + align:start position:0% +uh +just one particle on one side and one + + align:start position:0% +just one particle on one side and one + + + align:start position:0% +just one particle on one side and one +particle on the other + + align:start position:0% + + + + align:start position:0% + +side so the total n is + + align:start position:0% +side so the total n is + + + align:start position:0% +side so the total n is +two it's it's actually two divided by + + align:start position:0% +two it's it's actually two divided by + + + align:start position:0% +two it's it's actually two divided by +av's + + align:start position:0% +av's + + + align:start position:0% +av's +number + + align:start position:0% +number + + + align:start position:0% +number +so that entropy of mixing is uh + + align:start position:0% +so that entropy of mixing is uh + + + align:start position:0% +so that entropy of mixing is uh +twice BS one constant log of + + align:start position:0% + + + + align:start position:0% + +two okay + + align:start position:0% + + + + align:start position:0% + +so what is the the Gibs + + align:start position:0% +so what is the the Gibs + + + align:start position:0% +so what is the the Gibs +Paradox the Gibs Paradox runs as follows + + align:start position:0% +Paradox the Gibs Paradox runs as follows + + + align:start position:0% +Paradox the Gibs Paradox runs as follows +uh + + align:start position:0% +uh + + + align:start position:0% +uh +um there is a saying uh that + + align:start position:0% +um there is a saying uh that + + + align:start position:0% +um there is a saying uh that +uh I know it in + + align:start position:0% +uh I know it in + + + align:start position:0% +uh I know it in +uh in Latin NATA + + align:start position:0% + + + + align:start position:0% + +non + + align:start position:0% +non + + + align:start position:0% +non +fit + + align:start position:0% +fit + + + align:start position:0% +fit +salum it means nature doesn't make + + align:start position:0% +salum it means nature doesn't make + + + align:start position:0% +salum it means nature doesn't make +jumps and this is a I think it goes back + + align:start position:0% +jumps and this is a I think it goes back + + + align:start position:0% +jumps and this is a I think it goes back +to Aristotle or maybe Li NS I mean + + align:start position:0% +to Aristotle or maybe Li NS I mean + + + align:start position:0% +to Aristotle or maybe Li NS I mean +everybody every every + + align:start position:0% +everybody every every + + + align:start position:0% +everybody every every +philosopher uh has uh touched on these + + align:start position:0% + + + + align:start position:0% + +idea so what what Gibbs I think the Gibs + + align:start position:0% +idea so what what Gibbs I think the Gibs + + + align:start position:0% +idea so what what Gibbs I think the Gibs +they call it I really don't know maybe + + align:start position:0% +they call it I really don't know maybe + + + align:start position:0% +they call it I really don't know maybe +when we should look it up about the + + align:start position:0% +when we should look it up about the + + + align:start position:0% +when we should look it up about the +history of these things is is + + align:start position:0% +history of these things is is + + + align:start position:0% +history of these things is is +interesting is a chapter in itself so + + align:start position:0% +interesting is a chapter in itself so + + + align:start position:0% +interesting is a chapter in itself so +I'm not an expert in that in that either + + align:start position:0% +I'm not an expert in that in that either + + + align:start position:0% +I'm not an expert in that in that either +but suppose that it was Gibbs who + + align:start position:0% +but suppose that it was Gibbs who + + + align:start position:0% +but suppose that it was Gibbs who +realized that all right suppose + + align:start position:0% +realized that all right suppose + + + align:start position:0% +realized that all right suppose +I I have um I'm coloring these + + align:start position:0% +I I have um I'm coloring these + + + align:start position:0% +I I have um I'm coloring these +particles with a d and so + + align:start position:0% + + + + align:start position:0% + +suppose the amount of + + align:start position:0% +suppose the amount of + + + align:start position:0% +suppose the amount of +uh + + align:start position:0% +uh + + + align:start position:0% +uh +distance in color is measured by this + + align:start position:0% +distance in color is measured by this + + + align:start position:0% +distance in color is measured by this +parameter Lambda so I say zero means the + + align:start position:0% +parameter Lambda so I say zero means the + + + align:start position:0% +parameter Lambda so I say zero means the +particles are the same color Lambda + + align:start position:0% +particles are the same color Lambda + + + align:start position:0% +particles are the same color Lambda +greater than zero it means that the + + align:start position:0% +greater than zero it means that the + + + align:start position:0% +greater than zero it means that the +particles are different + + align:start position:0% + + + + align:start position:0% + +color all right so regardless of the + + align:start position:0% +color all right so regardless of the + + + align:start position:0% +color all right so regardless of the +color here we see that the result this + + align:start position:0% +color here we see that the result this + + + align:start position:0% +color here we see that the result this +result the entropy of mixing is the same + + align:start position:0% +result the entropy of mixing is the same + + + align:start position:0% +result the entropy of mixing is the same +regardless of how different the + + align:start position:0% +regardless of how different the + + + align:start position:0% +regardless of how different the +particles + + align:start position:0% +particles + + + align:start position:0% + +are there is no detail about what the + + align:start position:0% +are there is no detail about what the + + + align:start position:0% +are there is no detail about what the +particles or the mass is it's just how + + align:start position:0% +particles or the mass is it's just how + + + align:start position:0% +particles or the mass is it's just how +many they + + align:start position:0% +many they + + + align:start position:0% +many they +are so the entropy of mixing is always + + align:start position:0% +are so the entropy of mixing is always + + + align:start position:0% +are so the entropy of mixing is always +given by this amount and are uh log of + + align:start position:0% +given by this amount and are uh log of + + + align:start position:0% +given by this amount and are uh log of +two + + align:start position:0% + + + + align:start position:0% + +say + + align:start position:0% +say + + + align:start position:0% +say +except and so you would you say right as + + align:start position:0% +except and so you would you say right as + + + align:start position:0% +except and so you would you say right as +Lambda goes to zero I would + + align:start position:0% +Lambda goes to zero I would + + + align:start position:0% +Lambda goes to zero I would +expect that to also go + + align:start position:0% +expect that to also go + + + align:start position:0% +expect that to also go +uh continuously instead as you go to + + align:start position:0% +uh continuously instead as you go to + + + align:start position:0% +uh continuously instead as you go to +zero that jumps to + + align:start position:0% +zero that jumps to + + + align:start position:0% +zero that jumps to +zero + + align:start position:0% +zero + + + align:start position:0% +zero +because + + align:start position:0% +because + + + align:start position:0% +because +we if we think in terms of the simple + + align:start position:0% +we if we think in terms of the simple + + + align:start position:0% +we if we think in terms of the simple +system model you remember + + align:start position:0% +system model you remember + + + align:start position:0% +system model you remember +that uh when we have a a pure substance + + align:start position:0% +that uh when we have a a pure substance + + + align:start position:0% +that uh when we have a a pure substance +putting a partition or removing it + + align:start position:0% +putting a partition or removing it + + + align:start position:0% +putting a partition or removing it +doesn't change the properties so that's + + align:start position:0% +doesn't change the properties so that's + + + align:start position:0% +doesn't change the properties so that's +one quick way since we have seen + + align:start position:0% +one quick way since we have seen + + + align:start position:0% +one quick way since we have seen +uh a lot before to show that if the + + align:start position:0% +uh a lot before to show that if the + + + align:start position:0% +uh a lot before to show that if the +particles are + + align:start position:0% +particles are + + + align:start position:0% +particles are +identical there will be removing the + + align:start position:0% +identical there will be removing the + + + align:start position:0% +identical there will be removing the +partition will not change any of the + + align:start position:0% +partition will not change any of the + + + align:start position:0% +partition will not change any of the +properties including + + align:start position:0% + + + + align:start position:0% + +entropy so there is no entropy of mixing + + align:start position:0% +entropy so there is no entropy of mixing + + + align:start position:0% +entropy so there is no entropy of mixing +in this case if you + + align:start position:0% +in this case if you + + + align:start position:0% +in this case if you +mix the same substance there is no + + align:start position:0% +mix the same substance there is no + + + align:start position:0% +mix the same substance there is no +entropy of mixing as soon as they become + + align:start position:0% +entropy of mixing as soon as they become + + + align:start position:0% +entropy of mixing as soon as they become +different there is entropy of mixing and + + align:start position:0% +different there is entropy of mixing and + + + align:start position:0% +different there is entropy of mixing and +it is + + align:start position:0% +it is + + + align:start position:0% +it is +discontinuous so that's why the + + align:start position:0% +discontinuous so that's why the + + + align:start position:0% +discontinuous so that's why the +philosophers didn't like this + + align:start position:0% + + + + align:start position:0% + +idea but in + + align:start position:0% +idea but in + + + align:start position:0% +idea but in +fact it all has to do with the fact that + + align:start position:0% +fact it all has to do with the fact that + + + align:start position:0% +fact it all has to do with the fact that +we are doing modeling of + + align:start position:0% + + + + align:start position:0% + +reality + + align:start position:0% +reality + + + align:start position:0% +reality +so + + align:start position:0% +so + + + align:start position:0% +so +nature is the way we model + + align:start position:0% + + + + align:start position:0% + +it so if we have a possibility to + + align:start position:0% +it so if we have a possibility to + + + align:start position:0% +it so if we have a possibility to +distinguish the particles and + + align:start position:0% +distinguish the particles and + + + align:start position:0% +distinguish the particles and +therefore they are different for us + + align:start position:0% +therefore they are different for us + + + align:start position:0% +therefore they are different for us +then there is + + align:start position:0% +then there is + + + align:start position:0% +then there is +mixing and if there is entropy of mixing + + align:start position:0% +mixing and if there is entropy of mixing + + + align:start position:0% +mixing and if there is entropy of mixing +there is also the possibility to do + + align:start position:0% +there is also the possibility to do + + + align:start position:0% +there is also the possibility to do +work as we've seen we can we can do this + + align:start position:0% +work as we've seen we can we can do this + + + align:start position:0% +work as we've seen we can we can do this +work this U mixing uh properly and + + align:start position:0% +work this U mixing uh properly and + + + align:start position:0% +work this U mixing uh properly and +extract some work + + align:start position:0% +extract some work + + + align:start position:0% +extract some work +but if we don't have uh the possibility + + align:start position:0% +but if we don't have uh the possibility + + + align:start position:0% +but if we don't have uh the possibility +to recognize to identify to distinguish + + align:start position:0% +to recognize to identify to distinguish + + + align:start position:0% +to recognize to identify to distinguish +the + + align:start position:0% +the + + + align:start position:0% +the +particles that work is impossible for us + + align:start position:0% +particles that work is impossible for us + + + align:start position:0% +particles that work is impossible for us +so it has to do with the the way we + + align:start position:0% +so it has to do with the the way we + + + align:start position:0% +so it has to do with the the way we +model it or if you really want to go + + align:start position:0% +model it or if you really want to go + + + align:start position:0% +model it or if you really want to go +nature if the particles are truly + + align:start position:0% +nature if the particles are truly + + + align:start position:0% +nature if the particles are truly +indistinguishable + + align:start position:0% + + + + align:start position:0% + +in the sense quantum mechanics + + align:start position:0% +in the sense quantum mechanics + + + align:start position:0% +in the sense quantum mechanics +distinguishable + + align:start position:0% +distinguishable + + + align:start position:0% +distinguishable +indistinguishable fermion bosons and + + align:start position:0% +indistinguishable fermion bosons and + + + align:start position:0% +indistinguishable fermion bosons and +that kind of + + align:start position:0% +that kind of + + + align:start position:0% +that kind of +discussion + + align:start position:0% +discussion + + + align:start position:0% +discussion +then there is no way you can distinguish + + align:start position:0% +then there is no way you can distinguish + + + align:start position:0% +then there is no way you can distinguish +there is no way you can uh extract any + + align:start position:0% +there is no way you can uh extract any + + + align:start position:0% +there is no way you can uh extract any +work uh if the particles are + + align:start position:0% +work uh if the particles are + + + align:start position:0% +work uh if the particles are +distinguishable then it all depends + + align:start position:0% +distinguishable then it all depends + + + align:start position:0% +distinguishable then it all depends +on your model namely on your kind of + + align:start position:0% +on your model namely on your kind of + + + align:start position:0% +on your model namely on your kind of +tool that you are considering in your + + align:start position:0% + + + + align:start position:0% + +model so so that's essentially the + + align:start position:0% +model so so that's essentially the + + + align:start position:0% +model so so that's essentially the +resolution of the Paradox there's no + + align:start position:0% +resolution of the Paradox there's no + + + align:start position:0% +resolution of the Paradox there's no +Paradox it's it's it's through like this + + align:start position:0% +Paradox it's it's it's through like this + + + align:start position:0% +Paradox it's it's it's through like this +and the this continuity going from here + + align:start position:0% +and the this continuity going from here + + + align:start position:0% +and the this continuity going from here +to there + + align:start position:0% +to there + + + align:start position:0% +to there +is essentially embedded in uh in the our + + align:start position:0% +is essentially embedded in uh in the our + + + align:start position:0% +is essentially embedded in uh in the our +modeling or from the Practical point of + + align:start position:0% +modeling or from the Practical point of + + + align:start position:0% +modeling or from the Practical point of +view our ability to control the + + align:start position:0% +view our ability to control the + + + align:start position:0% +view our ability to control the +differences in + + align:start position:0% +differences in + + + align:start position:0% +differences in +particles because if the particles are + + align:start position:0% +particles because if the particles are + + + align:start position:0% +particles because if the particles are +different but we have no ways to uh + + align:start position:0% +different but we have no ways to uh + + + align:start position:0% +different but we have no ways to uh +control their differences and + + align:start position:0% +control their differences and + + + align:start position:0% +control their differences and +therefore uh + + align:start position:0% +therefore uh + + + align:start position:0% +therefore uh +build semi-permeable membranes + + align:start position:0% +build semi-permeable membranes + + + align:start position:0% +build semi-permeable membranes +that can + + align:start position:0% +that can + + + align:start position:0% +that can +select then obtaining that + + align:start position:0% +select then obtaining that + + + align:start position:0% +select then obtaining that +work is out of our + + align:start position:0% + + + + align:start position:0% + +reach + + align:start position:0% +reach + + + align:start position:0% +reach +okay so that's the Gibs + + align:start position:0% + + + + align:start position:0% + +Paradox and since we are at it I want to + + align:start position:0% +Paradox and since we are at it I want to + + + align:start position:0% +Paradox and since we are at it I want to +take a little DET tour today + + align:start position:0% +take a little DET tour today + + + align:start position:0% +take a little DET tour today +uh uh also on some other topics that + + align:start position:0% +uh uh also on some other topics that + + + align:start position:0% +uh uh also on some other topics that +are important in statistics in + + align:start position:0% +are important in statistics in + + + align:start position:0% +are important in statistics in +information Theory and also in Quantum + + align:start position:0% +information Theory and also in Quantum + + + align:start position:0% +information Theory and also in Quantum +uh + + align:start position:0% + + + + align:start position:0% + +Theory so again look at this um box with + + align:start position:0% +Theory so again look at this um box with + + + align:start position:0% +Theory so again look at this um box with +particles different + + align:start position:0% + + + + align:start position:0% + +particles and suppose you make an + + align:start position:0% +particles and suppose you make an + + + align:start position:0% +particles and suppose you make an +experiment by having a little um + + align:start position:0% +experiment by having a little um + + + align:start position:0% +experiment by having a little um +window someplace like a control volume + + align:start position:0% +window someplace like a control volume + + + align:start position:0% +window someplace like a control volume +somewhere in that in that U uh + + align:start position:0% + + + + align:start position:0% + +container where you can look if there is + + align:start position:0% +container where you can look if there is + + + align:start position:0% +container where you can look if there is +a particle in there there can be only + + align:start position:0% +a particle in there there can be only + + + align:start position:0% +a particle in there there can be only +one at a time it's a small control + + align:start position:0% +one at a time it's a small control + + + align:start position:0% +one at a time it's a small control +volume + + align:start position:0% +volume + + + align:start position:0% +volume +you you write it down in your + + align:start position:0% +you you write it down in your + + + align:start position:0% +you you write it down in your +experimental uh uh + + align:start position:0% +experimental uh uh + + + align:start position:0% +experimental uh uh +notebook I say oh yeah I saw a molecule + + align:start position:0% +notebook I say oh yeah I saw a molecule + + + align:start position:0% +notebook I say oh yeah I saw a molecule +of nitrogen or I saw a molecule of + + align:start position:0% +of nitrogen or I saw a molecule of + + + align:start position:0% +of nitrogen or I saw a molecule of +oxygen or I saw a molecule of + + align:start position:0% +oxygen or I saw a molecule of + + + align:start position:0% +oxygen or I saw a molecule of +argon or I saw a molecule of + + align:start position:0% +argon or I saw a molecule of + + + align:start position:0% +argon or I saw a molecule of +CO2 if that's + + align:start position:0% +CO2 if that's + + + align:start position:0% +CO2 if that's +air this + + align:start position:0% +air this + + + align:start position:0% +air this +is uh the + + align:start position:0% +is uh the + + + align:start position:0% +is uh the +idea and if you are in a stable in a + + align:start position:0% +idea and if you are in a stable in a + + + align:start position:0% +idea and if you are in a stable in a +stable equilibrium + + align:start position:0% + + + + align:start position:0% + +State um and + + align:start position:0% +State um and + + + align:start position:0% +State um and +therefore the probabilities + + align:start position:0% +therefore the probabilities + + + align:start position:0% +therefore the probabilities +that you find that you observe one of + + align:start position:0% +that you find that you observe one of + + + align:start position:0% +that you find that you observe one of +these molecules is + + align:start position:0% +these molecules is + + + align:start position:0% +these molecules is +proportional to the fraction of + + align:start position:0% +proportional to the fraction of + + + align:start position:0% +proportional to the fraction of +particles overall so it's the mole + + align:start position:0% +particles overall so it's the mole + + + align:start position:0% +particles overall so it's the mole +fraction so the mole fraction which by + + align:start position:0% +fraction so the mole fraction which by + + + align:start position:0% +fraction so the mole fraction which by +the way is a number like probability now + + align:start position:0% +the way is a number like probability now + + + align:start position:0% +the way is a number like probability now +it's a number between zero and one and + + align:start position:0% +it's a number between zero and one and + + + align:start position:0% +it's a number between zero and one and +it adds up to + + align:start position:0% +it adds up to + + + align:start position:0% +it adds up to +one so the mo fraction is the + + align:start position:0% +one so the mo fraction is the + + + align:start position:0% +one so the mo fraction is the +probability to get the particle of that + + align:start position:0% +probability to get the particle of that + + + align:start position:0% +probability to get the particle of that +type + + align:start position:0% + + + + align:start position:0% + +okay so there is + + align:start position:0% + + + + align:start position:0% + +a a measure if so if + + align:start position:0% +a a measure if so if + + + align:start position:0% +a a measure if so if +you if you are facing this situation + + align:start position:0% +you if you are facing this situation + + + align:start position:0% +you if you are facing this situation +with + + align:start position:0% + + + + align:start position:0% + +probabilities you are in an + + align:start position:0% +probabilities you are in an + + + align:start position:0% +probabilities you are in an +uncertainty + + align:start position:0% +uncertainty + + + align:start position:0% +uncertainty +situation you are uncertain uncertain + + align:start position:0% +situation you are uncertain uncertain + + + align:start position:0% +situation you are uncertain uncertain +about + + align:start position:0% +about + + + align:start position:0% +about +what will be the outcome of the next + + align:start position:0% +what will be the outcome of the next + + + align:start position:0% +what will be the outcome of the next +observation you cannot + + align:start position:0% +observation you cannot + + + align:start position:0% +observation you cannot +predict the next time that's what I will + + align:start position:0% +predict the next time that's what I will + + + align:start position:0% +predict the next time that's what I will +get but you can predict because you know + + align:start position:0% +get but you can predict because you know + + + align:start position:0% +get but you can predict because you know +the mo fractions with what frequency you + + align:start position:0% +the mo fractions with what frequency you + + + align:start position:0% +the mo fractions with what frequency you +will get these results upon repeated + + align:start position:0% + + + + align:start position:0% + +measurement but when you are facing uh + + align:start position:0% +measurement but when you are facing uh + + + align:start position:0% +measurement but when you are facing uh +the next observation and uh you a big + + align:start position:0% +the next observation and uh you a big + + + align:start position:0% +the next observation and uh you a big +question mark in your in your mind and + + align:start position:0% +question mark in your in your mind and + + + align:start position:0% +question mark in your in your mind and +asking all right what will be the next + + align:start position:0% +asking all right what will be the next + + + align:start position:0% +asking all right what will be the next +outcome you are in a state of + + align:start position:0% +outcome you are in a state of + + + align:start position:0% +outcome you are in a state of +uncertainty and the the + + align:start position:0% +uncertainty and the the + + + align:start position:0% +uncertainty and the the +uncertainty can be + + align:start position:0% +uncertainty can be + + + align:start position:0% +uncertainty can be +measured by this measure of + + align:start position:0% +measured by this measure of + + + align:start position:0% +measured by this measure of +information is called the Shannon + + align:start position:0% +information is called the Shannon + + + align:start position:0% +information is called the Shannon +information entropy Shannon + + align:start position:0% +information entropy Shannon + + + align:start position:0% +information entropy Shannon +1948 uh said well if I uh look at the + + align:start position:0% +1948 uh said well if I uh look at the + + + align:start position:0% +1948 uh said well if I uh look at the +situation described by probabilities + + align:start position:0% +situation described by probabilities + + + align:start position:0% +situation described by probabilities +like these events and I want to find uh + + align:start position:0% +like these events and I want to find uh + + + align:start position:0% +like these events and I want to find uh +the most uh uh logical + + align:start position:0% +the most uh uh logical + + + align:start position:0% +the most uh uh logical +uh mathematical expression or or + + align:start position:0% +uh mathematical expression or or + + + align:start position:0% +uh mathematical expression or or +function of these probabilities that + + align:start position:0% +function of these probabilities that + + + align:start position:0% +function of these probabilities that +expresses my state of + + align:start position:0% + + + + align:start position:0% + +uncertainty he set up some postulates + + align:start position:0% +uncertainty he set up some postulates + + + align:start position:0% +uncertainty he set up some postulates +some desiderata about this measurement + + align:start position:0% +some desiderata about this measurement + + + align:start position:0% +some desiderata about this measurement +uh um + + align:start position:0% +uh um + + + align:start position:0% +uh um +function of + + align:start position:0% +function of + + + align:start position:0% +function of +probabilities and uh the only function + + align:start position:0% +probabilities and uh the only function + + + align:start position:0% +probabilities and uh the only function +that satisfies those criteria is this + + align:start position:0% + + + + align:start position:0% + +one for + + align:start position:0% +one for + + + align:start position:0% +one for +example see if you are that is equal to + + align:start position:0% +example see if you are that is equal to + + + align:start position:0% +example see if you are that is equal to +zero if you have certainty so if if the + + align:start position:0% +zero if you have certainty so if if the + + + align:start position:0% +zero if you have certainty so if if the +probabilities are all zeros except one + + align:start position:0% +probabilities are all zeros except one + + + align:start position:0% +probabilities are all zeros except one +event that is equal to + + align:start position:0% +event that is equal to + + + align:start position:0% +event that is equal to +one so you have certainty so particles + + align:start position:0% +one so you have certainty so particles + + + align:start position:0% +one so you have certainty so particles +of only one Type M fraction is + + align:start position:0% +of only one Type M fraction is + + + align:start position:0% +of only one Type M fraction is +one okay uh well log of + + align:start position:0% +one okay uh well log of + + + align:start position:0% +one okay uh well log of +one is + + align:start position:0% +one is + + + align:start position:0% +one is +zero and X log X for those that are zero + + align:start position:0% +zero and X log X for those that are zero + + + align:start position:0% +zero and X log X for those that are zero +is again zero because you remember that + + align:start position:0% +is again zero because you remember that + + + align:start position:0% +is again zero because you remember that +this functions uh P log + + align:start position:0% +this functions uh P log + + + align:start position:0% +this functions uh P log +P look this way between zero and one + + align:start position:0% +P look this way between zero and one + + + align:start position:0% +P look this way between zero and one +this is the + + align:start position:0% +this is the + + + align:start position:0% +this is the +function uh X log + + align:start position:0% +function uh X log + + + align:start position:0% +function uh X log +X + + align:start position:0% +X + + + align:start position:0% +X +okay so in that case of complete + + align:start position:0% +okay so in that case of complete + + + align:start position:0% +okay so in that case of complete +certainty the information entropy is + + align:start position:0% + + + + align:start position:0% + +zero or on the opposite side if all + + align:start position:0% +zero or on the opposite side if all + + + align:start position:0% +zero or on the opposite side if all +particles have equal + + align:start position:0% +particles have equal + + + align:start position:0% +particles have equal +probability so all the uh Mo fractions + + align:start position:0% +probability so all the uh Mo fractions + + + align:start position:0% +probability so all the uh Mo fractions +are + + align:start position:0% +are + + + align:start position:0% +are +equal and in that case uh the + + align:start position:0% +equal and in that case uh the + + + align:start position:0% +equal and in that case uh the +entropy is equal to + + align:start position:0% +entropy is equal to + + + align:start position:0% +entropy is equal to +uh + + align:start position:0% +uh + + + align:start position:0% +uh +log of n of uh the number of of log of R + + align:start position:0% +log of n of uh the number of of log of R + + + align:start position:0% +log of n of uh the number of of log of R +in this case it's it's the number of + + align:start position:0% +in this case it's it's the number of + + + align:start position:0% +in this case it's it's the number of +different + + align:start position:0% + + + + align:start position:0% + +particles you can work it out you + + align:start position:0% +particles you can work it out you + + + align:start position:0% +particles you can work it out you +substitute each probability is one + + align:start position:0% +substitute each probability is one + + + align:start position:0% +substitute each probability is one +over + + align:start position:0% +over + + + align:start position:0% +over +R and that this summation gives a um log + + align:start position:0% +R and that this summation gives a um log + + + align:start position:0% +R and that this summation gives a um log +of + + align:start position:0% +of + + + align:start position:0% +of +R that's the maximum the most uncertain + + align:start position:0% +R that's the maximum the most uncertain + + + align:start position:0% +R that's the maximum the most uncertain +situation when they're all + + align:start position:0% +situation when they're all + + + align:start position:0% +situation when they're all +alike if you have instead a situation + + align:start position:0% +alike if you have instead a situation + + + align:start position:0% +alike if you have instead a situation +like uh for the molecules of + + align:start position:0% +like uh for the molecules of + + + align:start position:0% +like uh for the molecules of +air it's not + + align:start position:0% + + + + align:start position:0% + +even and therefore some are more uh + + align:start position:0% +even and therefore some are more uh + + + align:start position:0% +even and therefore some are more uh +frequent than others so you could get + + align:start position:0% +frequent than others so you could get + + + align:start position:0% +frequent than others so you could get +you could guess some uh um some better + + align:start position:0% +you could guess some uh um some better + + + align:start position:0% +you could guess some uh um some better +than if everything was just + + align:start position:0% + + + + align:start position:0% + +50% you can also + + align:start position:0% +50% you can also + + + align:start position:0% +50% you can also +view this is interesting also for us for + + align:start position:0% +view this is interesting also for us for + + + align:start position:0% +view this is interesting also for us for +the next step in the next definition + + align:start position:0% +the next step in the next definition + + + align:start position:0% +the next step in the next definition +of ideal + + align:start position:0% +of ideal + + + align:start position:0% +of ideal +solution you can also view this as a + + align:start position:0% +solution you can also view this as a + + + align:start position:0% +solution you can also view this as a +weighted + + align:start position:0% + + + + align:start position:0% + +sum weight on the mole + + align:start position:0% +sum weight on the mole + + + align:start position:0% +sum weight on the mole +fractions see I can view this as the + + align:start position:0% +fractions see I can view this as the + + + align:start position:0% +fractions see I can view this as the +summation the mole + + align:start position:0% +summation the mole + + + align:start position:0% +summation the mole +fraction times + + align:start position:0% +fraction times + + + align:start position:0% +fraction times +minus log of + + align:start position:0% + + + + align:start position:0% + +Y now this term in parenthesis we + + align:start position:0% +Y now this term in parenthesis we + + + align:start position:0% +Y now this term in parenthesis we +could call it the + + align:start position:0% +could call it the + + + align:start position:0% +could call it the +surprise the + + align:start position:0% +surprise the + + + align:start position:0% +surprise the +surprise the surprise is a measure + + align:start position:0% + + + + align:start position:0% + +uh it's high for the least probable + + align:start position:0% + + + + align:start position:0% + +ones so if I get H I could say that if I + + align:start position:0% +ones so if I get H I could say that if I + + + align:start position:0% +ones so if I get H I could say that if I +get a if I see a molecule of CO2 + + align:start position:0% +get a if I see a molecule of CO2 + + + align:start position:0% +get a if I see a molecule of CO2 +there and I know that there are only 500 + + align:start position:0% +there and I know that there are only 500 + + + align:start position:0% +there and I know that there are only 500 +ppms part per million so there is very + + align:start position:0% +ppms part per million so there is very + + + align:start position:0% +ppms part per million so there is very +low probability so if I see that one I'm + + align:start position:0% +low probability so if I see that one I'm + + + align:start position:0% +low probability so if I see that one I'm +kind of more surprised than if I see + + align:start position:0% +kind of more surprised than if I see + + + align:start position:0% +kind of more surprised than if I see +nitrogen or an + + align:start position:0% +nitrogen or an + + + align:start position:0% +nitrogen or an +oxygen argon also is a bit of a surprise + + align:start position:0% +oxygen argon also is a bit of a surprise + + + align:start position:0% +oxygen argon also is a bit of a surprise +because argon is less than + + align:start position:0% +because argon is less than + + + align:start position:0% +because argon is less than +1% so I need + + align:start position:0% +1% so I need + + + align:start position:0% +1% so I need +to uh do 100 trials to have on average + + align:start position:0% +to uh do 100 trials to have on average + + + align:start position:0% +to uh do 100 trials to have on average +one + + align:start position:0% +one + + + align:start position:0% +one +argon and uh here I need the uh + + align:start position:0% +argon and uh here I need the uh + + + align:start position:0% +argon and uh here I need the uh +2,000 trials to get one + + align:start position:0% +2,000 trials to get one + + + align:start position:0% +2,000 trials to get one +CO2 okay so that's the + + align:start position:0% + + + + align:start position:0% + +surprise now in information Theory there + + align:start position:0% +surprise now in information Theory there + + + align:start position:0% +surprise now in information Theory there +is also this problem that is also + + align:start position:0% +is also this problem that is also + + + align:start position:0% +is also this problem that is also +relevant for uh + + align:start position:0% +relevant for uh + + + align:start position:0% +relevant for uh +measurements for example suppose that + + align:start position:0% + + + + align:start position:0% + +you uh your device that finds the + + align:start position:0% +you uh your device that finds the + + + align:start position:0% +you uh your device that finds the +particle uh and characterizes the + + align:start position:0% +particle uh and characterizes the + + + align:start position:0% +particle uh and characterizes the +particle by uh the + + align:start position:0% +particle by uh the + + + align:start position:0% +particle by uh the +mass so when the when the particle is in + + align:start position:0% +mass so when the when the particle is in + + + align:start position:0% +mass so when the when the particle is in +your + + align:start position:0% +your + + + align:start position:0% +your +window your + + align:start position:0% +window your + + + align:start position:0% +window your +device uh maybe a spectrometer or + + align:start position:0% +device uh maybe a spectrometer or + + + align:start position:0% +device uh maybe a spectrometer or +whatever it tells you okay it was a mass + + align:start position:0% +whatever it tells you okay it was a mass + + + align:start position:0% +whatever it tells you okay it was a mass +a particle with this + + align:start position:0% + + + + align:start position:0% + +Mass so in the end when you do a + + align:start position:0% +Mass so in the end when you do a + + + align:start position:0% +Mass so in the end when you do a +measurement like a repeated uh + + align:start position:0% +measurement like a repeated uh + + + align:start position:0% +measurement like a repeated uh +measurement procedure in the end you + + align:start position:0% +measurement procedure in the end you + + + align:start position:0% +measurement procedure in the end you +will + + align:start position:0% +will + + + align:start position:0% +will +find uh the average or the + + align:start position:0% +find uh the average or the + + + align:start position:0% +find uh the average or the +mean + + align:start position:0% +mean + + + align:start position:0% +mean +mass that shows + + align:start position:0% +mass that shows + + + align:start position:0% +mass that shows +up and suppose that that's all that you + + align:start position:0% +up and suppose that that's all that you + + + align:start position:0% +up and suppose that that's all that you +can measure of your + + align:start position:0% +can measure of your + + + align:start position:0% +can measure of your +substance so all you can measure is the + + align:start position:0% +substance so all you can measure is the + + + align:start position:0% +substance so all you can measure is the +average value of the + + align:start position:0% + + + + align:start position:0% + +mass if that's the only information I + + align:start position:0% +mass if that's the only information I + + + align:start position:0% +mass if that's the only information I +have about my system could I make an + + align:start position:0% +have about my system could I make an + + + align:start position:0% +have about my system could I make an +educated guess of what the probability + + align:start position:0% +educated guess of what the probability + + + align:start position:0% +educated guess of what the probability +uh distribution so therefore what the + + align:start position:0% +uh distribution so therefore what the + + + align:start position:0% +uh distribution so therefore what the +mole fractions + + align:start position:0% + + + + align:start position:0% + +are and here + + align:start position:0% +are and here + + + align:start position:0% +are and here +comes U information Theory and again + + align:start position:0% +comes U information Theory and again + + + align:start position:0% +comes U information Theory and again +based on Shannon information + + align:start position:0% +based on Shannon information + + + align:start position:0% +based on Shannon information +entropy you say all + + align:start position:0% + + + + align:start position:0% + +right in order to make the educated + + align:start position:0% +right in order to make the educated + + + align:start position:0% +right in order to make the educated +guess I should uh + + align:start position:0% +guess I should uh + + + align:start position:0% +guess I should uh +avoid any bias that is not contained in + + align:start position:0% +avoid any bias that is not contained in + + + align:start position:0% +avoid any bias that is not contained in +the information I have about the system + + align:start position:0% +the information I have about the system + + + align:start position:0% +the information I have about the system +so I should + + align:start position:0% +so I should + + + align:start position:0% +so I should +use the information I have the measured + + align:start position:0% +use the information I have the measured + + + align:start position:0% +use the information I have the measured +values but not extra + + align:start position:0% +values but not extra + + + align:start position:0% +values but not extra +stuff so I want to make the least biased + + align:start position:0% +stuff so I want to make the least biased + + + align:start position:0% +stuff so I want to make the least biased +guess and the least guy bias guess is is + + align:start position:0% +guess and the least guy bias guess is is + + + align:start position:0% +guess and the least guy bias guess is is +obtained by saying all right what is the + + align:start position:0% +obtained by saying all right what is the + + + align:start position:0% +obtained by saying all right what is the +probability + + align:start position:0% +probability + + + align:start position:0% +probability +distribution that maximizes the shown + + align:start position:0% +distribution that maximizes the shown + + + align:start position:0% +distribution that maximizes the shown +information + + align:start position:0% +information + + + align:start position:0% +information +in other words it leaves me with the + + align:start position:0% +in other words it leaves me with the + + + align:start position:0% +in other words it leaves me with the +highest possible uncertainty compatible + + align:start position:0% +highest possible uncertainty compatible + + + align:start position:0% +highest possible uncertainty compatible +with that mean value that I I have + + align:start position:0% +with that mean value that I I have + + + align:start position:0% +with that mean value that I I have +observed in this way if uh I have not + + align:start position:0% +observed in this way if uh I have not + + + align:start position:0% +observed in this way if uh I have not +built in uh the probability distribution + + align:start position:0% +built in uh the probability distribution + + + align:start position:0% +built in uh the probability distribution +any extra + + align:start position:0% +any extra + + + align:start position:0% +any extra +information + + align:start position:0% + + + + align:start position:0% + +uh and so mathematically this means you + + align:start position:0% +uh and so mathematically this means you + + + align:start position:0% +uh and so mathematically this means you +have to + + align:start position:0% +have to + + + align:start position:0% +have to +maximize the on + + align:start position:0% +maximize the on + + + align:start position:0% +maximize the on +entropy subject to the constraint that + + align:start position:0% +entropy subject to the constraint that + + + align:start position:0% +entropy subject to the constraint that +your mean value be the non or measured + + align:start position:0% +your mean value be the non or measured + + + align:start position:0% +your mean value be the non or measured +value of course you also have to put the + + align:start position:0% +value of course you also have to put the + + + align:start position:0% +value of course you also have to put the +uh auxiliary constraint that + + align:start position:0% +uh auxiliary constraint that + + + align:start position:0% +uh auxiliary constraint that +probabilities must add up to + + align:start position:0% +probabilities must add up to + + + align:start position:0% +probabilities must add up to +one and if you solve + + align:start position:0% +one and if you solve + + + align:start position:0% +one and if you solve +this uh problem with the method of + + align:start position:0% +this uh problem with the method of + + + align:start position:0% +this uh problem with the method of +lrange + + align:start position:0% +lrange + + + align:start position:0% +lrange +multipliers I'm don't want to just go + + align:start position:0% +multipliers I'm don't want to just go + + + align:start position:0% +multipliers I'm don't want to just go +over that today but maybe later on on WE + + align:start position:0% +over that today but maybe later on on WE + + + align:start position:0% +over that today but maybe later on on WE +since we uh we we will uh will we'll + + align:start position:0% +since we uh we we will uh will we'll + + + align:start position:0% +since we uh we we will uh will we'll +review it uh uh in any case I presume + + align:start position:0% +review it uh uh in any case I presume + + + align:start position:0% +review it uh uh in any case I presume +that you have seen it somewhere else uh + + align:start position:0% +that you have seen it somewhere else uh + + + align:start position:0% +that you have seen it somewhere else uh +so the method simply says all right if + + align:start position:0% +so the method simply says all right if + + + align:start position:0% +so the method simply says all right if +you have a constraint maximization you + + align:start position:0% +you have a constraint maximization you + + + align:start position:0% +you have a constraint maximization you +must assign to each of the constraints a + + align:start position:0% +must assign to each of the constraints a + + + align:start position:0% +must assign to each of the constraints a +lrange multip a multiplier and under + + align:start position:0% +lrange multip a multiplier and under + + + align:start position:0% +lrange multip a multiplier and under +term in the + + align:start position:0% + + + + align:start position:0% + +multiplier uh then + + align:start position:0% +multiplier uh then + + + align:start position:0% +multiplier uh then +do an unconstrained maximization of the + + align:start position:0% +do an unconstrained maximization of the + + + align:start position:0% +do an unconstrained maximization of the +optimizing + + align:start position:0% +optimizing + + + align:start position:0% +optimizing +function uh minus the constraints + + align:start position:0% +function uh minus the constraints + + + align:start position:0% +function uh minus the constraints +multiplied by these + + align:start position:0% +multiplied by these + + + align:start position:0% +multiplied by these +multipliers and then once you obtain the + + align:start position:0% +multipliers and then once you obtain the + + + align:start position:0% +multipliers and then once you obtain the +solution of the unconstrained maximum in + + align:start position:0% +solution of the unconstrained maximum in + + + align:start position:0% +solution of the unconstrained maximum in +terms of these multipliers you will + + align:start position:0% +terms of these multipliers you will + + + align:start position:0% +terms of these multipliers you will +substitute back into the constraints and + + align:start position:0% +substitute back into the constraints and + + + align:start position:0% +substitute back into the constraints and +uh get the values for the multipliers + + align:start position:0% +uh get the values for the multipliers + + + align:start position:0% +uh get the values for the multipliers +all right that's + + align:start position:0% +all right that's + + + align:start position:0% +all right that's +a quick so I don't expect you to have + + align:start position:0% +a quick so I don't expect you to have + + + align:start position:0% +a quick so I don't expect you to have +learned it from from these words but in + + align:start position:0% +learned it from from these words but in + + + align:start position:0% +learned it from from these words but in +any case if you do the job here's the + + align:start position:0% +any case if you do the job here's the + + + align:start position:0% +any case if you do the job here's the +probability distribution that you + + align:start position:0% +probability distribution that you + + + align:start position:0% +probability distribution that you +get and + + align:start position:0% +get and + + + align:start position:0% +get and +uh if you + + align:start position:0% +uh if you + + + align:start position:0% +uh if you +substitute this probability back into + + align:start position:0% +substitute this probability back into + + + align:start position:0% +substitute this probability back into +the + + align:start position:0% +the + + + align:start position:0% +the +constraint this one that gives you the + + align:start position:0% +constraint this one that gives you the + + + align:start position:0% +constraint this one that gives you the +average + + align:start position:0% +average + + + align:start position:0% +average +M it uh gives you a + + align:start position:0% +M it uh gives you a + + + align:start position:0% +M it uh gives you a +relation between the Lambda M which is + + align:start position:0% +relation between the Lambda M which is + + + align:start position:0% +relation between the Lambda M which is +the lrange multiplier and the mean value + + align:start position:0% +the lrange multiplier and the mean value + + + align:start position:0% +the lrange multiplier and the mean value +so you get that the lrange multiplier + + align:start position:0% +so you get that the lrange multiplier + + + align:start position:0% +so you get that the lrange multiplier +depends on that mean value of the + + align:start position:0% +depends on that mean value of the + + + align:start position:0% +depends on that mean value of the +mass so this is the + + align:start position:0% +mass so this is the + + + align:start position:0% +mass so this is the +best or at least the least biased + + align:start position:0% +best or at least the least biased + + + align:start position:0% +best or at least the least biased +assignment of M fractions that you can + + align:start position:0% +assignment of M fractions that you can + + + align:start position:0% +assignment of M fractions that you can +do upon a measurement of only the + + align:start position:0% + + + + align:start position:0% + +mass we will see in a while that uh this + + align:start position:0% +mass we will see in a while that uh this + + + align:start position:0% +mass we will see in a while that uh this +probability + + align:start position:0% +probability + + + align:start position:0% +probability +distribution is very similar to what you + + align:start position:0% +distribution is very similar to what you + + + align:start position:0% +distribution is very similar to what you +obtain uh what you have for the + + align:start position:0% +obtain uh what you have for the + + + align:start position:0% +obtain uh what you have for the +description of stable equilibrium States + + align:start position:0% +description of stable equilibrium States + + + align:start position:0% +description of stable equilibrium States +within statistical mechanics and quantum + + align:start position:0% +within statistical mechanics and quantum + + + align:start position:0% +within statistical mechanics and quantum +theory it's called the canonical + + align:start position:0% +theory it's called the canonical + + + align:start position:0% +theory it's called the canonical +distribution If instead of mass you put + + align:start position:0% +distribution If instead of mass you put + + + align:start position:0% +distribution If instead of mass you put +energy and that allows or + + align:start position:0% +energy and that allows or + + + align:start position:0% +energy and that allows or +allowed uh + + align:start position:0% +allowed uh + + + align:start position:0% +allowed uh +researchers like uh + + align:start position:0% +researchers like uh + + + align:start position:0% +researchers like uh +James it's a big + + align:start position:0% +James it's a big + + + align:start position:0% +James it's a big +name who made uh + + align:start position:0% +name who made uh + + + align:start position:0% +name who made uh +these very neat connections between + + align:start position:0% +these very neat connections between + + + align:start position:0% +these very neat connections between +information Theory and statistical + + align:start position:0% + + + + align:start position:0% + +mechanics or also uh if + + align:start position:0% +mechanics or also uh if + + + align:start position:0% +mechanics or also uh if +you if you if you still go to the + + align:start position:0% +you if you if you still go to the + + + align:start position:0% +you if you if you still go to the +library here at MIT there is a wonderful + + align:start position:0% +library here at MIT there is a wonderful + + + align:start position:0% +library here at MIT there is a wonderful +um set of video + + align:start position:0% +um set of video + + + align:start position:0% +um set of video +lectures by Professor myON + + align:start position:0% +lectures by Professor myON + + + align:start position:0% +lectures by Professor myON +tribus back in I think the 60s or the + + align:start position:0% + + + + align:start position:0% + +70s uh where he does uh the information + + align:start position:0% +70s uh where he does uh the information + + + align:start position:0% +70s uh where he does uh the information +Theory point of view of thermodynamics + + align:start position:0% +Theory point of view of thermodynamics + + + align:start position:0% +Theory point of view of thermodynamics +so he develops the entire thermodynamics + + align:start position:0% +so he develops the entire thermodynamics + + + align:start position:0% +so he develops the entire thermodynamics +just by building up on uh information + + align:start position:0% +just by building up on uh information + + + align:start position:0% +just by building up on uh information +Theory + + align:start position:0% +Theory + + + align:start position:0% +Theory +concept and indeed + + align:start position:0% +concept and indeed + + + align:start position:0% +concept and indeed +there is uh a ground for doing it + + align:start position:0% +there is uh a ground for doing it + + + align:start position:0% +there is uh a ground for doing it +because the molecular view that we are + + align:start position:0% +because the molecular view that we are + + + align:start position:0% +because the molecular view that we are +discussing here and the tools developed + + align:start position:0% +discussing here and the tools developed + + + align:start position:0% +discussing here and the tools developed +by Shannon do pro do provide that + + align:start position:0% + + + + align:start position:0% + +possibility so I said that I wanted to + + align:start position:0% +possibility so I said that I wanted to + + + align:start position:0% +possibility so I said that I wanted to +make a little uh degression today + + align:start position:0% +make a little uh degression today + + + align:start position:0% +make a little uh degression today +so here is a degression in the + + align:start position:0% +so here is a degression in the + + + align:start position:0% +so here is a degression in the +degression + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% + + + + align:start position:0% + +uh it has to + + align:start position:0% +uh it has to + + + align:start position:0% +uh it has to +do with the + + align:start position:0% + + + + align:start position:0% + +treatment of a + + align:start position:0% +treatment of a + + + align:start position:0% +treatment of a +particle in a + + align:start position:0% + + + + align:start position:0% + +box okay so we take a + + align:start position:0% +box okay so we take a + + + align:start position:0% +box okay so we take a +box of uh sides L1 L2 and L3 in the + + align:start position:0% +box of uh sides L1 L2 and L3 in the + + + align:start position:0% +box of uh sides L1 L2 and L3 in the +three + + align:start position:0% +three + + + align:start position:0% +three +directions and we consider only one + + align:start position:0% +directions and we consider only one + + + align:start position:0% +directions and we consider only one +particle inside this + + align:start position:0% +particle inside this + + + align:start position:0% +particle inside this +box that's the + + align:start position:0% + + + + align:start position:0% + +idea of uh of this little uh survey of + + align:start position:0% +idea of uh of this little uh survey of + + + align:start position:0% +idea of uh of this little uh survey of +uh with some equations that are borrowed + + align:start position:0% +uh with some equations that are borrowed + + + align:start position:0% +uh with some equations that are borrowed +from quantum + + align:start position:0% + + + + align:start position:0% + +mechanics + + align:start position:0% +mechanics + + + align:start position:0% +mechanics +uh which you may be familiar or not but + + align:start position:0% +uh which you may be familiar or not but + + + align:start position:0% +uh which you may be familiar or not but +uh uh even if you are not it's okay this + + align:start position:0% +uh uh even if you are not it's okay this + + + align:start position:0% +uh uh even if you are not it's okay this +is a just a quick + + align:start position:0% +is a just a quick + + + align:start position:0% +is a just a quick +view that tells you how all these things + + align:start position:0% +view that tells you how all these things + + + align:start position:0% +view that tells you how all these things +are related so it might might be + + align:start position:0% +are related so it might might be + + + align:start position:0% +are related so it might might be +interesting um I will not ask for this + + align:start position:0% +interesting um I will not ask for this + + + align:start position:0% +interesting um I will not ask for this +in in + + align:start position:0% +in in + + + align:start position:0% +in in +the oral exam of course and actually one + + align:start position:0% +the oral exam of course and actually one + + + align:start position:0% +the oral exam of course and actually one +day I will let you know + + align:start position:0% +day I will let you know + + + align:start position:0% +day I will let you know +which are of the many things that we + + align:start position:0% +which are of the many things that we + + + align:start position:0% +which are of the many things that we +cover the uh slides that uh are to be um + + align:start position:0% +cover the uh slides that uh are to be um + + + align:start position:0% +cover the uh slides that uh are to be um +I me are going to be part of the exam so + + align:start position:0% +I me are going to be part of the exam so + + + align:start position:0% +I me are going to be part of the exam so +that you can focus and because otherwise + + align:start position:0% +that you can focus and because otherwise + + + align:start position:0% +that you can focus and because otherwise +it's too much I I perfectly realize all + + align:start position:0% +it's too much I I perfectly realize all + + + align:start position:0% +it's too much I I perfectly realize all +right so uh the idea in quantum + + align:start position:0% +right so uh the idea in quantum + + + align:start position:0% +right so uh the idea in quantum +mechanics is that um in order to uh + + align:start position:0% +mechanics is that um in order to uh + + + align:start position:0% +mechanics is that um in order to uh +describe uh + + align:start position:0% +describe uh + + + align:start position:0% +describe uh +molecule like that or even + + align:start position:0% +molecule like that or even + + + align:start position:0% +molecule like that or even +simpler if you have a molecule on a + + align:start position:0% +simpler if you have a molecule on a + + + align:start position:0% +simpler if you have a molecule on a +one-dimensional box that we already + + align:start position:0% +one-dimensional box that we already + + + align:start position:0% +one-dimensional box that we already +mentioned + + align:start position:0% + + + + align:start position:0% + +uh so suppose we have just + + align:start position:0% +uh so suppose we have just + + + align:start position:0% +uh so suppose we have just +onedimensional + + align:start position:0% +onedimensional + + + align:start position:0% +onedimensional +box in classical mechanics the particle + + align:start position:0% +box in classical mechanics the particle + + + align:start position:0% +box in classical mechanics the particle +is here and it goes uh back and forth + + align:start position:0% +is here and it goes uh back and forth + + + align:start position:0% +is here and it goes uh back and forth +It's Perfectly uh uh situated somewhere + + align:start position:0% +It's Perfectly uh uh situated somewhere + + + align:start position:0% +It's Perfectly uh uh situated somewhere +at every instant of time in uh quantum + + align:start position:0% +at every instant of time in uh quantum + + + align:start position:0% +at every instant of time in uh quantum +mechanics the story is different + + align:start position:0% +mechanics the story is different + + + align:start position:0% +mechanics the story is different +particle cannot be is not I mean the the + + align:start position:0% +particle cannot be is not I mean the the + + + align:start position:0% +particle cannot be is not I mean the the +idea of viewing the particle as + + align:start position:0% +idea of viewing the particle as + + + align:start position:0% +idea of viewing the particle as +localized is wrong it gives you some + + align:start position:0% +localized is wrong it gives you some + + + align:start position:0% +localized is wrong it gives you some +results that that are + + align:start position:0% +results that that are + + + align:start position:0% +results that that are +wrong so the idea of quantum mechanics + + align:start position:0% +wrong so the idea of quantum mechanics + + + align:start position:0% +wrong so the idea of quantum mechanics +is that you start from you have + + align:start position:0% +is that you start from you have + + + align:start position:0% +is that you start from you have +to uh + + align:start position:0% + + + + align:start position:0% + +find a + + align:start position:0% +find a + + + align:start position:0% +find a +probability + + align:start position:0% +probability + + + align:start position:0% +probability +distribution which uh can be obtained by + + align:start position:0% +distribution which uh can be obtained by + + + align:start position:0% +distribution which uh can be obtained by +a function let's say + + align:start position:0% + + + + align:start position:0% + +Fe + + align:start position:0% +Fe + + + align:start position:0% +Fe +okay and this + + align:start position:0% +okay and this + + + align:start position:0% +okay and this +function uh is the uh + + align:start position:0% +function uh is the uh + + + align:start position:0% +function uh is the uh +solution of U an igen value problem + + align:start position:0% + + + + align:start position:0% + +and uh for + + align:start position:0% +and uh for + + + align:start position:0% +and uh for +example first of all this function can + + align:start position:0% +example first of all this function can + + + align:start position:0% +example first of all this function can +be also written as uh the + + align:start position:0% +be also written as uh the + + + align:start position:0% +be also written as uh the +factors so it's a product of a function + + align:start position:0% +factors so it's a product of a function + + + align:start position:0% +factors so it's a product of a function +of X and the function of uh + + align:start position:0% +of X and the function of uh + + + align:start position:0% +of X and the function of uh +time and the function of time uh + + align:start position:0% +time and the function of time uh + + + align:start position:0% +time and the function of time uh +remember uh it's + + align:start position:0% +remember uh it's + + + align:start position:0% +remember uh it's +minus uh H bar times the + + align:start position:0% +minus uh H bar times the + + + align:start position:0% +minus uh H bar times the +energy times time + + align:start position:0% +energy times time + + + align:start position:0% +energy times time +over + + align:start position:0% + + + + align:start position:0% + +something it will it will come up uh + + align:start position:0% +something it will it will come up uh + + + align:start position:0% +something it will it will come up uh +somewhere uh over M + + align:start position:0% + + + + align:start position:0% + +probably not sure okay so the idea is + + align:start position:0% +probably not sure okay so the idea is + + + align:start position:0% +probably not sure okay so the idea is +that this function here the one that + + align:start position:0% +that this function here the one that + + + align:start position:0% +that this function here the one that +depends on + + align:start position:0% +depends on + + + align:start position:0% +depends on +X is the solution of an igen value uh + + align:start position:0% +X is the solution of an igen value uh + + + align:start position:0% +X is the solution of an igen value uh +problem uh + + align:start position:0% +problem uh + + + align:start position:0% +problem uh +and these + + align:start position:0% +and these + + + align:start position:0% +and these +functions are you can plot them as + + align:start position:0% + + + + align:start position:0% + +follows as we as we know uh um actually + + align:start position:0% +follows as we as we know uh um actually + + + align:start position:0% +follows as we as we know uh um actually +I think we have we have the expression + + align:start position:0% +I think we have we have the expression + + + align:start position:0% +I think we have we have the expression +it's something like square root of + + align:start position:0% +it's something like square root of + + + align:start position:0% +it's something like square root of +uh + + align:start position:0% +uh + + + align:start position:0% +uh +um 2 over + + align:start position:0% +um 2 over + + + align:start position:0% +um 2 over +L where L is the side so this is from + + align:start position:0% +L where L is the side so this is from + + + align:start position:0% +L where L is the side so this is from +zero to + + align:start position:0% +zero to + + + align:start position:0% +zero to +L + + align:start position:0% + + + + align:start position:0% + +times s of uh some + + align:start position:0% +times s of uh some + + + align:start position:0% +times s of uh some +J some maybe X + + align:start position:0% + + + + align:start position:0% + +and there are some other constants here + + align:start position:0% +and there are some other constants here + + + align:start position:0% +and there are some other constants here +that I now slips uh my uh + + align:start position:0% +that I now slips uh my uh + + + align:start position:0% +that I now slips uh my uh +memory and it's maybe + + align:start position:0% +memory and it's maybe + + + align:start position:0% +memory and it's maybe +uh maybe uh H over 2 m or something like + + align:start position:0% + + + + align:start position:0% + +that or maybe also an + + align:start position:0% +that or maybe also an + + + align:start position:0% +that or maybe also an +L uh there is also an L here + + align:start position:0% + + + + align:start position:0% + +okay so the idea is that this + + align:start position:0% +okay so the idea is that this + + + align:start position:0% +okay so the idea is that this +J is the integer + + align:start position:0% +J is the integer + + + align:start position:0% +J is the integer +numbers so there are many possible uh + + align:start position:0% +numbers so there are many possible uh + + + align:start position:0% +numbers so there are many possible uh +contributions each one of these for each + + align:start position:0% +contributions each one of these for each + + + align:start position:0% +contributions each one of these for each +J corresponds to a + + align:start position:0% +J corresponds to a + + + align:start position:0% +J corresponds to a +solution uh and to that solution + + align:start position:0% +solution uh and to that solution + + + align:start position:0% +solution uh and to that solution +corresponds + + align:start position:0% +corresponds + + + align:start position:0% +corresponds +also a uh an energy level so for example + + align:start position:0% +also a uh an energy level so for example + + + align:start position:0% +also a uh an energy level so for example +the the low lowest energy level + + align:start position:0% +the the low lowest energy level + + + align:start position:0% +the the low lowest energy level +corresponding to J is equal to + + align:start position:0% +corresponding to J is equal to + + + align:start position:0% +corresponding to J is equal to +1 is a function like + + align:start position:0% + + + + align:start position:0% + +this then you may have the second energy + + align:start position:0% + + + + align:start position:0% + +level uh in + + align:start position:0% +level uh in + + + align:start position:0% +level uh in +which the + + align:start position:0% +which the + + + align:start position:0% +which the +function is something like + + align:start position:0% + + + + align:start position:0% + +this and then J equal to uh + + align:start position:0% + + + + align:start position:0% + +3 right and so + + align:start position:0% +3 right and so + + + align:start position:0% +3 right and so +on corresponding to each of these + + align:start position:0% +on corresponding to each of these + + + align:start position:0% +on corresponding to each of these +JS there are + + align:start position:0% +JS there are + + + align:start position:0% +JS there are +energies or actually on the slide I'm + + align:start position:0% +energies or actually on the slide I'm + + + align:start position:0% +energies or actually on the slide I'm +calling them uh Epsilon J + + align:start position:0% + + + + align:start position:0% + +okay and these energies are + + align:start position:0% +okay and these energies are + + + align:start position:0% +okay and these energies are +H squar over 2 + + align:start position:0% +H squar over 2 + + + align:start position:0% +H squar over 2 +m multiplied by J 2 over L + + align:start position:0% + + + + align:start position:0% + +2 maybe there's a pi + + align:start position:0% + + + + align:start position:0% + +here because it needs to go to to to + + align:start position:0% +here because it needs to go to to to + + + align:start position:0% +here because it needs to go to to to +zero at zero and at L + + align:start position:0% +zero at zero and at L + + + align:start position:0% +zero at zero and at L +so okay so that means + + align:start position:0% + + + + align:start position:0% + +that if this Epsilon one is the lowest + + align:start position:0% +that if this Epsilon one is the lowest + + + align:start position:0% +that if this Epsilon one is the lowest +energy + + align:start position:0% + + + + align:start position:0% + +level Epsilon + + align:start position:0% +level Epsilon + + + align:start position:0% +level Epsilon +2 is equal + + align:start position:0% +2 is equal + + + align:start position:0% +2 is equal +to uh it corresponds to J equals 2 so + + align:start position:0% +to uh it corresponds to J equals 2 so + + + align:start position:0% +to uh it corresponds to J equals 2 so +it's equals to j s is four times Epsilon + + align:start position:0% + + + + align:start position:0% + +1 and Epsilon 3 + + align:start position:0% + + + + align:start position:0% + +is 3 to the 2 so it's 9 * Epsilon + + align:start position:0% +is 3 to the 2 so it's 9 * Epsilon + + + align:start position:0% +is 3 to the 2 so it's 9 * Epsilon +1 and so on + + align:start position:0% + + + + align:start position:0% + +okay so already this gives you the + + align:start position:0% +okay so already this gives you the + + + align:start position:0% +okay so already this gives you the +energy + + align:start position:0% +energy + + + align:start position:0% +energy +levels now in an in an experiment that + + align:start position:0% +levels now in an in an experiment that + + + align:start position:0% +levels now in an in an experiment that +you do for example with uh + + align:start position:0% +you do for example with uh + + + align:start position:0% +you do for example with uh +spectroscopy on the + + align:start position:0% +spectroscopy on the + + + align:start position:0% +spectroscopy on the +particle uh you can measure the energy + + align:start position:0% +particle uh you can measure the energy + + + align:start position:0% +particle uh you can measure the energy +of the + + align:start position:0% + + + + align:start position:0% + +particle and it and you're facing a + + align:start position:0% +particle and it and you're facing a + + + align:start position:0% +particle and it and you're facing a +situation like the one that we just done + + align:start position:0% +situation like the one that we just done + + + align:start position:0% +situation like the one that we just done +with the uh the mass of the particles + + align:start position:0% +with the uh the mass of the particles + + + align:start position:0% +with the uh the mass of the particles +that you don't know which one uh okay + + align:start position:0% +that you don't know which one uh okay + + + align:start position:0% +that you don't know which one uh okay +here it's a similar situation you do a + + align:start position:0% +here it's a similar situation you do a + + + align:start position:0% +here it's a similar situation you do a +measurement of energy and you don't know + + align:start position:0% +measurement of energy and you don't know + + + align:start position:0% +measurement of energy and you don't know +which + + align:start position:0% +which + + + align:start position:0% +which +one of the energies possible energies + + align:start position:0% +one of the energies possible energies + + + align:start position:0% +one of the energies possible energies +you get because the particle is not the + + align:start position:0% +you get because the particle is not the + + + align:start position:0% +you get because the particle is not the +definitely on this not always I mean + + align:start position:0% +definitely on this not always I mean + + + align:start position:0% +definitely on this not always I mean +most of the times it's in a + + align:start position:0% +most of the times it's in a + + + align:start position:0% +most of the times it's in a +superposition of energy levels so each + + align:start position:0% +superposition of energy levels so each + + + align:start position:0% +superposition of energy levels so each +one of them has a + + align:start position:0% +one of them has a + + + align:start position:0% +one of them has a +probability and the energy of uh of the + + align:start position:0% +probability and the energy of uh of the + + + align:start position:0% +probability and the energy of uh of the +particle is the weighted sum of these + + align:start position:0% +particle is the weighted sum of these + + + align:start position:0% +particle is the weighted sum of these +probabilities with with these + + align:start position:0% +probabilities with with these + + + align:start position:0% +probabilities with with these +probabilities of these energy + + align:start position:0% + + + + align:start position:0% + +levels so the state + + align:start position:0% +levels so the state + + + align:start position:0% +levels so the state +of the particle is represented by a + + align:start position:0% +of the particle is represented by a + + + align:start position:0% +of the particle is represented by a +probability distribution which + + align:start position:0% +probability distribution which + + + align:start position:0% +probability distribution which +uh at least in the stable equilibrium + + align:start position:0% +uh at least in the stable equilibrium + + + align:start position:0% +uh at least in the stable equilibrium +States can be viewed as the uh + + align:start position:0% +States can be viewed as the uh + + + align:start position:0% +States can be viewed as the uh +probability of finding the energy levels + + align:start position:0% +probability of finding the energy levels + + + align:start position:0% +probability of finding the energy levels +among these + + align:start position:0% + + + + align:start position:0% + +possibilities that is for the particle + + align:start position:0% +possibilities that is for the particle + + + align:start position:0% +possibilities that is for the particle +in one uh dimensional box if you have a + + align:start position:0% +in one uh dimensional box if you have a + + + align:start position:0% +in one uh dimensional box if you have a +three dimensional box each Direction has + + align:start position:0% +three dimensional box each Direction has + + + align:start position:0% +three dimensional box each Direction has +a it + + align:start position:0% +a it + + + align:start position:0% +a it +own contribution and actually this + + align:start position:0% +own contribution and actually this + + + align:start position:0% +own contribution and actually this +functions + + align:start position:0% +functions + + + align:start position:0% +functions +Factor so the + + align:start position:0% +Factor so the + + + align:start position:0% +Factor so the +three uh orthogonal translational + + align:start position:0% +three uh orthogonal translational + + + align:start position:0% +three uh orthogonal translational +degrees of freedom of the + + align:start position:0% +degrees of freedom of the + + + align:start position:0% +degrees of freedom of the +particle super superposed to in each + + align:start position:0% +particle super superposed to in each + + + align:start position:0% +particle super superposed to in each +other so it's like uh uh having three + + align:start position:0% +other so it's like uh uh having three + + + align:start position:0% +other so it's like uh uh having three +kind of uh of of of sub particles like + + align:start position:0% +kind of uh of of of sub particles like + + + align:start position:0% +kind of uh of of of sub particles like +in a perfect gas that uh sort of don't + + align:start position:0% +in a perfect gas that uh sort of don't + + + align:start position:0% +in a perfect gas that uh sort of don't +that ignore each other each each degree + + align:start position:0% +that ignore each other each each degree + + + align:start position:0% +that ignore each other each each degree +of Freedom lives by itself occupies uh + + align:start position:0% +of Freedom lives by itself occupies uh + + + align:start position:0% +of Freedom lives by itself occupies uh +its uh directional modes by itself + + align:start position:0% +its uh directional modes by itself + + + align:start position:0% +its uh directional modes by itself +without interacting with the other + + align:start position:0% +without interacting with the other + + + align:start position:0% +without interacting with the other +modes that's why this is such a simple + + align:start position:0% +modes that's why this is such a simple + + + align:start position:0% +modes that's why this is such a simple +uh uh extension of that just multiply so + + align:start position:0% +uh uh extension of that just multiply so + + + align:start position:0% +uh uh extension of that just multiply so +to speak or the the various uh + + align:start position:0% + + + + align:start position:0% + +functions not only but + + align:start position:0% +functions not only but + + + align:start position:0% +functions not only but +from this one from these results you can + + align:start position:0% +from this one from these results you can + + + align:start position:0% +from this one from these results you can +also obtain the + + align:start position:0% +also obtain the + + + align:start position:0% +also obtain the +probability of finding um the prob + + align:start position:0% +probability of finding um the prob + + + align:start position:0% +probability of finding um the prob +probability + + align:start position:0% +probability + + + align:start position:0% +probability +density of + + align:start position:0% +density of + + + align:start position:0% +density of +finding this uh uh particle if you make + + align:start position:0% +finding this uh uh particle if you make + + + align:start position:0% +finding this uh uh particle if you make +a position measurement finding it + + align:start position:0% +a position measurement finding it + + + align:start position:0% +a position measurement finding it +between X X and X Plus + + align:start position:0% +between X X and X Plus + + + align:start position:0% +between X X and X Plus +DX that's the PDF the probability + + align:start position:0% +DX that's the PDF the probability + + + align:start position:0% +DX that's the PDF the probability +density function it's given by the is + + align:start position:0% + + + + align:start position:0% + +s the modulus of this one or also that + + align:start position:0% +s the modulus of this one or also that + + + align:start position:0% +s the modulus of this one or also that +one + + align:start position:0% + + + + align:start position:0% + +and I think there is an I here that I am + + align:start position:0% +and I think there is an I here that I am + + + align:start position:0% +and I think there is an I here that I am +missing because this is supposed to be + + align:start position:0% +missing because this is supposed to be + + + align:start position:0% +missing because this is supposed to be +uh I is the square root of minus one + + align:start position:0% +uh I is the square root of minus one + + + align:start position:0% +uh I is the square root of minus one +okay so that means that when I do uh the + + align:start position:0% +okay so that means that when I do uh the + + + align:start position:0% +okay so that means that when I do uh the +complex conjugate of this one that be + + align:start position:0% +complex conjugate of this one that be + + + align:start position:0% +complex conjugate of this one that be +that I becomes minus I + + align:start position:0% +that I becomes minus I + + + align:start position:0% +that I becomes minus I +and so the modulus uh of V is equal to + + align:start position:0% +and so the modulus uh of V is equal to + + + align:start position:0% +and so the modulus uh of V is equal to +this one cancels and you're left + + align:start position:0% +this one cancels and you're left + + + align:start position:0% +this one cancels and you're left +with uh + + align:start position:0% + + + + align:start position:0% + +this which is the modulus of uh s + + align:start position:0% +this which is the modulus of uh s + + + align:start position:0% +this which is the modulus of uh s +squared and that is the probability + + align:start position:0% +squared and that is the probability + + + align:start position:0% +squared and that is the probability +density function so if you want to know + + align:start position:0% +density function so if you want to know + + + align:start position:0% +density function so if you want to know +how much is the probability in that + + align:start position:0% +how much is the probability in that + + + align:start position:0% +how much is the probability in that +interval you multiply by DX + + align:start position:0% + + + + align:start position:0% + +and if you want to know um the + + align:start position:0% +and if you want to know um the + + + align:start position:0% +and if you want to know um the +probability to go from to be from uh say + + align:start position:0% +probability to go from to be from uh say + + + align:start position:0% +probability to go from to be from uh say +from here to there you just do the + + align:start position:0% +from here to there you just do the + + + align:start position:0% +from here to there you just do the +integral from uh whatever X say X1 to X2 + + align:start position:0% +integral from uh whatever X say X1 to X2 + + + align:start position:0% +integral from uh whatever X say X1 to X2 +to get to get the overall + + align:start position:0% +to get to get the overall + + + align:start position:0% +to get to get the overall +distribution so these + + align:start position:0% +distribution so these + + + align:start position:0% +distribution so these +functions are these ones that I + + align:start position:0% + + + + align:start position:0% + +plotted I wish I had more space okay + + align:start position:0% +plotted I wish I had more space okay + + + align:start position:0% +plotted I wish I had more space okay +let's do this + + align:start position:0% + + + + align:start position:0% + +way so the + + align:start position:0% + + + + align:start position:0% + +probabilities are the + + align:start position:0% +probabilities are the + + + align:start position:0% +probabilities are the +square of these functions see this the + + align:start position:0% +square of these functions see this the + + + align:start position:0% +square of these functions see this the +way functions can go negative but the + + align:start position:0% +way functions can go negative but the + + + align:start position:0% +way functions can go negative but the +probability is essentially the + + align:start position:0% +probability is essentially the + + + align:start position:0% +probability is essentially the +square so take the square of this sign + + align:start position:0% +square so take the square of this sign + + + align:start position:0% +square so take the square of this sign +and become something like + + align:start position:0% +and become something like + + + align:start position:0% +and become something like +this the square of this other uh sign + + align:start position:0% +this the square of this other uh sign + + + align:start position:0% +this the square of this other uh sign +with it becomes something like + + align:start position:0% + + + + align:start position:0% + +this and so + + align:start position:0% + + + + align:start position:0% + +on and so on + + align:start position:0% + + + + align:start position:0% + +okay when the particle is in a given + + align:start position:0% + + + + align:start position:0% + +State uh it is not typically in just one + + align:start position:0% +State uh it is not typically in just one + + + align:start position:0% +State uh it is not typically in just one +of these energy + + align:start position:0% +of these energy + + + align:start position:0% +of these energy +levels it is in a probability + + align:start position:0% +levels it is in a probability + + + align:start position:0% +levels it is in a probability +distribution so each one of + + align:start position:0% +distribution so each one of + + + align:start position:0% +distribution so each one of +these um distributions in space is is + + align:start position:0% +these um distributions in space is is + + + align:start position:0% +these um distributions in space is is +weighted by a probability distribution + + align:start position:0% +weighted by a probability distribution + + + align:start position:0% +weighted by a probability distribution +so there will be a P1 it will be a P2 a + + align:start position:0% +so there will be a P1 it will be a P2 a + + + align:start position:0% +so there will be a P1 it will be a P2 a +P3 and so on so you have + + align:start position:0% +P3 and so on so you have + + + align:start position:0% +P3 and so on so you have +a weighted + + align:start position:0% +a weighted + + + align:start position:0% +a weighted +sum of these probabilities with which + + align:start position:0% +sum of these probabilities with which + + + align:start position:0% +sum of these probabilities with which +you can compute for + + align:start position:0% +you can compute for + + + align:start position:0% +you can compute for +example uh the + + align:start position:0% +example uh the + + + align:start position:0% +example uh the +um probability that your particles is + + align:start position:0% +um probability that your particles is + + + align:start position:0% +um probability that your particles is +between X and X Plus + + align:start position:0% + + + + align:start position:0% + +DX it's this area times + + align:start position:0% + + + + align:start position:0% + +P1 plus this area time + + align:start position:0% +P1 plus this area time + + + align:start position:0% +P1 plus this area time +P2 plus that area time P3 up to to + + align:start position:0% +P2 plus that area time P3 up to to + + + align:start position:0% +P2 plus that area time P3 up to to +Infinity because you have to go up this + + align:start position:0% +Infinity because you have to go up this + + + align:start position:0% +Infinity because you have to go up this +J goes up to + + align:start position:0% + + + + align:start position:0% + +infinity and that's how you + + align:start position:0% +infinity and that's how you + + + align:start position:0% +infinity and that's how you +compute the actual stable equilibrium + + align:start position:0% +compute the actual stable equilibrium + + + align:start position:0% +compute the actual stable equilibrium +State probability + + align:start position:0% + + + + align:start position:0% + +distribution this is already we already + + align:start position:0% +distribution this is already we already + + + align:start position:0% +distribution this is already we already +mentioned the fact that when you do this + + align:start position:0% +mentioned the fact that when you do this + + + align:start position:0% +mentioned the fact that when you do this +job and you can compute therefore + + align:start position:0% +job and you can compute therefore + + + align:start position:0% +job and you can compute therefore +the uh the probability density + + align:start position:0% +the uh the probability density + + + align:start position:0% +the uh the probability density +for every for every X you will find that + + align:start position:0% +for every for every X you will find that + + + align:start position:0% +for every for every X you will find that +it will always go to zero uh at the + + align:start position:0% +it will always go to zero uh at the + + + align:start position:0% +it will always go to zero uh at the +edges because at the edges no matter how + + align:start position:0% +edges because at the edges no matter how + + + align:start position:0% +edges because at the edges no matter how +you weight it it's always zero so the + + align:start position:0% +you weight it it's always zero so the + + + align:start position:0% +you weight it it's always zero so the +sum of zero is + + align:start position:0% +sum of zero is + + + align:start position:0% +sum of zero is +zero whereas in the + + align:start position:0% +zero whereas in the + + + align:start position:0% +zero whereas in the +center uh it you'll have some + + align:start position:0% + + + + align:start position:0% + +Wiggles + + align:start position:0% +Wiggles + + + align:start position:0% +Wiggles +especially if the + + align:start position:0% +especially if the + + + align:start position:0% +especially if the +low energy levels are important as you + + align:start position:0% +low energy levels are important as you + + + align:start position:0% +low energy levels are important as you +go upwards this becomes so uh you may + + align:start position:0% +go upwards this becomes so uh you may + + + align:start position:0% +go upwards this becomes so uh you may +have if the quantum number goes um as it + + align:start position:0% +have if the quantum number goes um as it + + + align:start position:0% +have if the quantum number goes um as it +goes higher these Wiggles become more uh + + align:start position:0% +goes higher these Wiggles become more uh + + + align:start position:0% +goes higher these Wiggles become more uh +intense and then they add up and so the + + align:start position:0% +intense and then they add up and so the + + + align:start position:0% +intense and then they add up and so the +one cancels the others and so the zero + + align:start position:0% +one cancels the others and so the zero + + + align:start position:0% +one cancels the others and so the zero +you'll get only zero at the walls but + + align:start position:0% +you'll get only zero at the walls but + + + align:start position:0% +you'll get only zero at the walls but +not in the middle not in the bulk + + align:start position:0% + + + + align:start position:0% + +okay so these are the energy + + align:start position:0% +okay so these are the energy + + + align:start position:0% +okay so these are the energy +levels here is the name for the + + align:start position:0% +levels here is the name for the + + + align:start position:0% +levels here is the name for the +probabilities that we simplified + + align:start position:0% +probabilities that we simplified + + + align:start position:0% +probabilities that we simplified +here in three dimensions you have three + + align:start position:0% +here in three dimensions you have three + + + align:start position:0% +here in three dimensions you have three +labels because you have one quantum + + align:start position:0% +labels because you have one quantum + + + align:start position:0% +labels because you have one quantum +number per + + align:start position:0% + + + + align:start position:0% + +Direction and the typical + + align:start position:0% + + + + align:start position:0% + +problem that you face if you do energy + + align:start position:0% +problem that you face if you do energy + + + align:start position:0% +problem that you face if you do energy +measure measurements + + align:start position:0% +measure measurements + + + align:start position:0% +measure measurements +is well how do I what's my best guess + + align:start position:0% +is well how do I what's my best guess + + + align:start position:0% +is well how do I what's my best guess +for this probability + + align:start position:0% + + + + align:start position:0% + +distribution that's the information + + align:start position:0% +distribution that's the information + + + align:start position:0% +distribution that's the information +Theory point of + + align:start position:0% + + + + align:start position:0% + +view uh the thermodynamics point of view + + align:start position:0% +view uh the thermodynamics point of view + + + align:start position:0% +view uh the thermodynamics point of view +is all right probabilities if we accept + + align:start position:0% +is all right probabilities if we accept + + + align:start position:0% +is all right probabilities if we accept +that probabilities represent the state + + align:start position:0% +that probabilities represent the state + + + align:start position:0% +that probabilities represent the state +and if we accept that + + align:start position:0% +and if we accept that + + + align:start position:0% +and if we accept that +entropy uh is measured by a function + + align:start position:0% +entropy uh is measured by a function + + + align:start position:0% +entropy uh is measured by a function +like + + align:start position:0% + + + + align:start position:0% + +this then we can use the maximum entropy + + align:start position:0% +this then we can use the maximum entropy + + + align:start position:0% +this then we can use the maximum entropy +principle which + + align:start position:0% +principle which + + + align:start position:0% +principle which +says for a given + + align:start position:0% + + + + align:start position:0% + +energy my + + align:start position:0% +energy my + + + align:start position:0% +energy my +system uh has + + align:start position:0% + + + + align:start position:0% + +um see of have an energy and an entropy + + align:start position:0% +um see of have an energy and an entropy + + + align:start position:0% +um see of have an energy and an entropy +an entropy + + align:start position:0% +an entropy + + + align:start position:0% +an entropy +diagram and for a given + + align:start position:0% + + + + align:start position:0% + +energy I may have many different + + align:start position:0% +energy I may have many different + + + align:start position:0% +energy I may have many different +states but if I'm looking for the stable + + align:start position:0% +states but if I'm looking for the stable + + + align:start position:0% +states but if I'm looking for the stable +equilibrium State I know that it has to + + align:start position:0% +equilibrium State I know that it has to + + + align:start position:0% +equilibrium State I know that it has to +have the maximum entropy for that given + + align:start position:0% +have the maximum entropy for that given + + + align:start position:0% +have the maximum entropy for that given +energy so that's precisely the same + + align:start position:0% +energy so that's precisely the same + + + align:start position:0% +energy so that's precisely the same +problem that we've seen before maximize + + align:start position:0% +problem that we've seen before maximize + + + align:start position:0% +problem that we've seen before maximize +entropy and provided you accept that for + + align:start position:0% +entropy and provided you accept that for + + + align:start position:0% +entropy and provided you accept that for +fora for the entropy of the Quantum of + + align:start position:0% +fora for the entropy of the Quantum of + + + align:start position:0% +fora for the entropy of the Quantum of +the quantum + + align:start position:0% + + + + align:start position:0% + +particle then the mathematics of uh + + align:start position:0% +particle then the mathematics of uh + + + align:start position:0% +particle then the mathematics of uh +maximization is the same use lrange + + align:start position:0% + + + + align:start position:0% + +multipliers now see since we know + + align:start position:0% +multipliers now see since we know + + + align:start position:0% +multipliers now see since we know +already the + + align:start position:0% +already the + + + align:start position:0% +already the +answer instead of call calling the + + align:start position:0% +answer instead of call calling the + + + align:start position:0% +answer instead of call calling the +lrange multiplier Lambda e + + align:start position:0% +lrange multiplier Lambda e + + + align:start position:0% +lrange multiplier Lambda e +which + + align:start position:0% +which + + + align:start position:0% +which +um uh + + align:start position:0% +um uh + + + align:start position:0% +um uh +since later on WE recognize that that + + align:start position:0% +since later on WE recognize that that + + + align:start position:0% +since later on WE recognize that that +Lambda is the inverse of the temperature + + align:start position:0% +Lambda is the inverse of the temperature + + + align:start position:0% +Lambda is the inverse of the temperature +divided by the boltman constant we we + + align:start position:0% +divided by the boltman constant we we + + + align:start position:0% +divided by the boltman constant we we +already call it 1 / + + align:start position:0% + + + + align:start position:0% + +KT and so you find this + + align:start position:0% +KT and so you find this + + + align:start position:0% +KT and so you find this +distribution so the + + align:start position:0% +distribution so the + + + align:start position:0% +distribution so the +probabilities are given by e to the + + align:start position:0% +probabilities are given by e to the + + + align:start position:0% +probabilities are given by e to the +minus the + + align:start position:0% +minus the + + + align:start position:0% +minus the +energy is energy + + align:start position:0% +energy is energy + + + align:start position:0% +energy is energy +values divided by or multiplied by the + + align:start position:0% +values divided by or multiplied by the + + + align:start position:0% +values divided by or multiplied by the +lrange multi + + align:start position:0% +lrange multi + + + align:start position:0% +lrange multi +mullier divided by this Q you can view + + align:start position:0% +mullier divided by this Q you can view + + + align:start position:0% +mullier divided by this Q you can view +it as a normalization factor it's + + align:start position:0% +it as a normalization factor it's + + + align:start position:0% +it as a normalization factor it's +essentially the summation of all these + + align:start position:0% +essentially the summation of all these + + + align:start position:0% +essentially the summation of all these +things at the + + align:start position:0% +things at the + + + align:start position:0% +things at the +numerator this + + align:start position:0% + + + + align:start position:0% + +q a also see that since the energies the + + align:start position:0% +q a also see that since the energies the + + + align:start position:0% +q a also see that since the energies the +energy I values add + + align:start position:0% +energy I values add + + + align:start position:0% +energy I values add +up uh the exponential of sum is equal to + + align:start position:0% +up uh the exponential of sum is equal to + + + align:start position:0% +up uh the exponential of sum is equal to +the product of the exponentials so these + + align:start position:0% +the product of the exponentials so these + + + align:start position:0% +the product of the exponentials so these +probability distributions + + align:start position:0% +probability distributions + + + align:start position:0% +probability distributions +factor + + align:start position:0% +factor + + + align:start position:0% +factor +into separate probability distributions + + align:start position:0% +into separate probability distributions + + + align:start position:0% +into separate probability distributions +for each of the directions of the + + align:start position:0% +for each of the directions of the + + + align:start position:0% +for each of the directions of the +box so so you can view the problem also + + align:start position:0% +box so so you can view the problem also + + + align:start position:0% +box so so you can view the problem also +just as you can solve it in One + + align:start position:0% +just as you can solve it in One + + + align:start position:0% +just as you can solve it in One +Direction per time and then simply + + align:start position:0% +Direction per time and then simply + + + align:start position:0% +Direction per time and then simply +multiply the results + + align:start position:0% + + + + align:start position:0% + +these denominators or denominator for + + align:start position:0% +these denominators or denominator for + + + align:start position:0% +these denominators or denominator for +the overall is called the partition + + align:start position:0% + + + + align:start position:0% + +function and uh it is yes it plays the + + align:start position:0% +function and uh it is yes it plays the + + + align:start position:0% +function and uh it is yes it plays the +role + + align:start position:0% +role + + + align:start position:0% +role +of the normalization factor so that + + align:start position:0% +of the normalization factor so that + + + align:start position:0% +of the normalization factor so that +uh uh when you sum the probabilities + + align:start position:0% +uh uh when you sum the probabilities + + + align:start position:0% +uh uh when you sum the probabilities +they add up to + + align:start position:0% +they add up to + + + align:start position:0% +they add up to +one but it also plays an interesting + + align:start position:0% +one but it also plays an interesting + + + align:start position:0% +one but it also plays an interesting +interesting role because uh uh uh + + align:start position:0% +interesting role because uh uh uh + + + align:start position:0% +interesting role because uh uh uh +essentially all you you you can extract + + align:start position:0% +essentially all you you you can extract + + + align:start position:0% +essentially all you you you can extract +everything if you know this partition + + align:start position:0% +everything if you know this partition + + + align:start position:0% +everything if you know this partition +function if you know this + + align:start position:0% +function if you know this + + + align:start position:0% +function if you know this +summation by playing with it in terms of + + align:start position:0% +summation by playing with it in terms of + + + align:start position:0% +summation by playing with it in terms of +taking some + + align:start position:0% +taking some + + + align:start position:0% +taking some +derivatives you can get uh everything of + + align:start position:0% +derivatives you can get uh everything of + + + align:start position:0% +derivatives you can get uh everything of +the distribution including the the + + align:start position:0% +the distribution including the the + + + align:start position:0% +the distribution including the the +probabilities + + align:start position:0% +probabilities + + + align:start position:0% +probabilities +themselves so if you take the the + + align:start position:0% +themselves so if you take the the + + + align:start position:0% +themselves so if you take the the +partial derivative of the logarithm of + + align:start position:0% +partial derivative of the logarithm of + + + align:start position:0% +partial derivative of the logarithm of +the partition function as written here + + align:start position:0% +the partition function as written here + + + align:start position:0% +the partition function as written here +and take the derivative with respect to + + align:start position:0% +and take the derivative with respect to + + + align:start position:0% +and take the derivative with respect to +the energy + + align:start position:0% +the energy + + + align:start position:0% +the energy +level you get the probability and + + align:start position:0% +level you get the probability and + + + align:start position:0% +level you get the probability and +multiply by KT and minus you get the + + align:start position:0% +multiply by KT and minus you get the + + + align:start position:0% +multiply by KT and minus you get the +probability of that energy of observing + + align:start position:0% +probability of that energy of observing + + + align:start position:0% +probability of that energy of observing +that energy + + align:start position:0% + + + + align:start position:0% + +level + + align:start position:0% +level + + + align:start position:0% +level +or you take this other derivative you + + align:start position:0% +or you take this other derivative you + + + align:start position:0% +or you take this other derivative you +take the derivative of Q respect to + + align:start position:0% +take the derivative of Q respect to + + + align:start position:0% +take the derivative of Q respect to +temperature because yes in a moment will + + align:start position:0% +temperature because yes in a moment will + + + align:start position:0% +temperature because yes in a moment will +recognize that + + align:start position:0% + + + + align:start position:0% + +U this + + align:start position:0% +U this + + + align:start position:0% +U this +T is also this lrange + + align:start position:0% +T is also this lrange + + + align:start position:0% +T is also this lrange +multiplier satisfies our definition of + + align:start position:0% +multiplier satisfies our definition of + + + align:start position:0% +multiplier satisfies our definition of +temperature is the partial of s e with + + align:start position:0% +temperature is the partial of s e with + + + align:start position:0% +temperature is the partial of s e with +respect to + + align:start position:0% +respect to + + + align:start position:0% +respect to +S and so you identify it with the + + align:start position:0% +S and so you identify it with the + + + align:start position:0% +S and so you identify it with the +temperature uh so you take the log the + + align:start position:0% +temperature uh so you take the log the + + + align:start position:0% +temperature uh so you take the log the +partial of log Q respect respect to + + align:start position:0% +partial of log Q respect respect to + + + align:start position:0% +partial of log Q respect respect to +t uh you get the + + align:start position:0% +t uh you get the + + + align:start position:0% +t uh you get the +energy the mean energy the mean energy + + align:start position:0% +energy the mean energy the mean energy + + + align:start position:0% +energy the mean energy the mean energy +is the average value of the energy it's + + align:start position:0% +is the average value of the energy it's + + + align:start position:0% +is the average value of the energy it's +so it's the weighted sum of these energy + + align:start position:0% +so it's the weighted sum of these energy + + + align:start position:0% +so it's the weighted sum of these energy +levels weighted on the probability that + + align:start position:0% +levels weighted on the probability that + + + align:start position:0% +levels weighted on the probability that +represents that + + align:start position:0% + + + + align:start position:0% + +state and also uh the + + align:start position:0% + + + + align:start position:0% + +entropy also the entropy because the + + align:start position:0% +entropy also the entropy because the + + + align:start position:0% +entropy also the entropy because the +probabilties + + align:start position:0% +probabilties + + + align:start position:0% +probabilties +Factor the entropies add because the + + align:start position:0% +Factor the entropies add because the + + + align:start position:0% +Factor the entropies add because the +logarithm you remember the logarithm of + + align:start position:0% +logarithm you remember the logarithm of + + + align:start position:0% +logarithm you remember the logarithm of +the product is equal to the sum of the + + align:start position:0% +the product is equal to the sum of the + + + align:start position:0% +the product is equal to the sum of the +logarithms so you can write the overall + + align:start position:0% +logarithms so you can write the overall + + + align:start position:0% +logarithms so you can write the overall +entropy and split it in the entropies of + + align:start position:0% +entropy and split it in the entropies of + + + align:start position:0% +entropy and split it in the entropies of +the three directions of the + + align:start position:0% +the three directions of the + + + align:start position:0% +the three directions of the +box and each one of them can be obtained + + align:start position:0% +box and each one of them can be obtained + + + align:start position:0% +box and each one of them can be obtained +as a proper derivative of + + align:start position:0% +as a proper derivative of + + + align:start position:0% +as a proper derivative of +Q or if you already taken the derivative + + align:start position:0% +Q or if you already taken the derivative + + + align:start position:0% +Q or if you already taken the derivative +that give the energy you can write S as + + align:start position:0% +that give the energy you can write S as + + + align:start position:0% +that give the energy you can write S as +e/ t + + align:start position:0% +e/ t + + + align:start position:0% +e/ t +plus bman constant time times the + + align:start position:0% +plus bman constant time times the + + + align:start position:0% +plus bman constant time times the +logarithm of the partition + + align:start position:0% +logarithm of the partition + + + align:start position:0% +logarithm of the partition +function this is somehow uh close to + + align:start position:0% +function this is somehow uh close to + + + align:start position:0% +function this is somehow uh close to +the as close as you can get to the oiler + + align:start position:0% +the as close as you can get to the oiler + + + align:start position:0% +the as close as you can get to the oiler +free free energy or the free energy + + align:start position:0% + + + + align:start position:0% + +because in fact some people call it call + + align:start position:0% +because in fact some people call it call + + + align:start position:0% +because in fact some people call it call +I mean you could also rewrite that as + + align:start position:0% +I mean you could also rewrite that as + + + align:start position:0% +I mean you could also rewrite that as +EI minus t SI I is equal to uh KB t log + + align:start position:0% +EI minus t SI I is equal to uh KB t log + + + align:start position:0% +EI minus t SI I is equal to uh KB t log +of + + align:start position:0% + + + + align:start position:0% + +Q probabbly with the minus sign + + align:start position:0% + + + + align:start position:0% + +yeah okay + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +so now going + + align:start position:0% +so now going + + + align:start position:0% +so now going +back to these + + align:start position:0% + + + + align:start position:0% + +probabilities this probability + + align:start position:0% +probabilities this probability + + + align:start position:0% +probabilities this probability +distribution is the one that + + align:start position:0% +distribution is the one that + + + align:start position:0% +distribution is the one that +characterizes the stable equilibrium + + align:start position:0% +characterizes the stable equilibrium + + + align:start position:0% +characterizes the stable equilibrium +state it characterizes this + + align:start position:0% +state it characterizes this + + + align:start position:0% +state it characterizes this +state how about these other ones + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so this canonical distribution the one + + align:start position:0% +so this canonical distribution the one + + + align:start position:0% +so this canonical distribution the one +maximum entropy one looks like + + align:start position:0% +maximum entropy one looks like + + + align:start position:0% +maximum entropy one looks like +this here for + + align:start position:0% +this here for + + + align:start position:0% +this here for +Simplicity I have drawn a system which + + align:start position:0% +Simplicity I have drawn a system which + + + align:start position:0% +Simplicity I have drawn a system which +doesn't have a + + align:start position:0% +doesn't have a + + + align:start position:0% +doesn't have a +uh this I value structure but it has + + align:start position:0% +uh this I value structure but it has + + + align:start position:0% +uh this I value structure but it has +energy levels that are equally spaced + + align:start position:0% +energy levels that are equally spaced + + + align:start position:0% +energy levels that are equally spaced +and there is only seven of them the + + align:start position:0% +and there is only seven of them the + + + align:start position:0% +and there is only seven of them the +lowest one one two 3 four five six seven + + align:start position:0% +lowest one one two 3 four five six seven + + + align:start position:0% +lowest one one two 3 four five six seven +okay equally + + align:start position:0% + + + + align:start position:0% + +spaced we have + + align:start position:0% + + + + align:start position:0% + +already uh mentioned that they that for + + align:start position:0% +already uh mentioned that they that for + + + align:start position:0% +already uh mentioned that they that for +a system with an upper bound to the uh + + align:start position:0% +a system with an upper bound to the uh + + + align:start position:0% +a system with an upper bound to the uh +energy Spectrum this is an R + + align:start position:0% +energy Spectrum this is an R + + + align:start position:0% +energy Spectrum this is an R +here that would be + + align:start position:0% + + + + align:start position:0% + +Spectrum the the ersus diagram doesn't + + align:start position:0% +Spectrum the the ersus diagram doesn't + + + align:start position:0% +Spectrum the the ersus diagram doesn't +go up indefinitely but it bends and + + align:start position:0% +go up indefinitely but it bends and + + + align:start position:0% +go up indefinitely but it bends and +returns so that's that's the + + align:start position:0% + + + + align:start position:0% + +case so we have only seven energy levels + + align:start position:0% +case so we have only seven energy levels + + + align:start position:0% +case so we have only seven energy levels +and we can uh picture these + + align:start position:0% +and we can uh picture these + + + align:start position:0% +and we can uh picture these +probabilities by an instogram + + align:start position:0% +probabilities by an instogram + + + align:start position:0% +probabilities by an instogram +histogram so this is the max maximum + + align:start position:0% +histogram so this is the max maximum + + + align:start position:0% +histogram so this is the max maximum +entropy the canonical + + align:start position:0% +entropy the canonical + + + align:start position:0% +entropy the canonical +distribution for example this is a zero + + align:start position:0% +distribution for example this is a zero + + + align:start position:0% +distribution for example this is a zero +entropy a zero entropy state in what is + + align:start position:0% +entropy a zero entropy state in what is + + + align:start position:0% +entropy a zero entropy state in what is +one in which you are + + align:start position:0% +one in which you are + + + align:start position:0% +one in which you are +certain remember the the the entropy in + + align:start position:0% +certain remember the the the entropy in + + + align:start position:0% +certain remember the the the entropy in +in terms of probabilities represents + + align:start position:0% +in terms of probabilities represents + + + align:start position:0% +in terms of probabilities represents +your state of uncertainty well if I know + + align:start position:0% +your state of uncertainty well if I know + + + align:start position:0% +your state of uncertainty well if I know +that every time I measure I always find + + align:start position:0% +that every time I measure I always find + + + align:start position:0% +that every time I measure I always find +the particle in that energy level uh I + + align:start position:0% +the particle in that energy level uh I + + + align:start position:0% +the particle in that energy level uh I +have no uncertainty the entropy is zero + + align:start position:0% +have no uncertainty the entropy is zero + + + align:start position:0% +have no uncertainty the entropy is zero +and that is when uh I have zeros for + + align:start position:0% +and that is when uh I have zeros for + + + align:start position:0% +and that is when uh I have zeros for +all um Poss probabilities except one + + align:start position:0% +all um Poss probabilities except one + + + align:start position:0% +all um Poss probabilities except one +which is equal to + + align:start position:0% + + + + align:start position:0% + +one a point like + + align:start position:0% +one a point like + + + align:start position:0% +one a point like +here is one that has an intermediate + + align:start position:0% +here is one that has an intermediate + + + align:start position:0% +here is one that has an intermediate +probability between zero and the + + align:start position:0% + + + + align:start position:0% + +maximum you can + + align:start position:0% +maximum you can + + + align:start position:0% +maximum you can +concoct uh an infinite number of + + align:start position:0% +concoct uh an infinite number of + + + align:start position:0% +concoct uh an infinite number of +possibilities + + align:start position:0% +possibilities + + + align:start position:0% +possibilities +of different probabilities probability + + align:start position:0% +of different probabilities probability + + + align:start position:0% +of different probabilities probability +distributions that have the same entropy + + align:start position:0% +distributions that have the same entropy + + + align:start position:0% +distributions that have the same entropy +and of course the same + + align:start position:0% +and of course the same + + + align:start position:0% +and of course the same +energy here are the + + align:start position:0% +energy here are the + + + align:start position:0% +energy here are the +ones + + align:start position:0% + + + + align:start position:0% + +okay uh why is that + + align:start position:0% + + + + align:start position:0% + +important okay when + + align:start position:0% +important okay when + + + align:start position:0% +important okay when +we when we are interested in describing + + align:start position:0% +we when we are interested in describing + + + align:start position:0% +we when we are interested in describing +non-equilibrium + + align:start position:0% +non-equilibrium + + + align:start position:0% +non-equilibrium +States what is important is + + align:start position:0% +States what is important is + + + align:start position:0% +States what is important is +to uh be able to understand or + + align:start position:0% +to uh be able to understand or + + + align:start position:0% +to uh be able to understand or +model how these states or these + + align:start position:0% +model how these states or these + + + align:start position:0% +model how these states or these +probability + + align:start position:0% +probability + + + align:start position:0% +probability +distributions evolve towards equilibrium + + align:start position:0% +distributions evolve towards equilibrium + + + align:start position:0% +distributions evolve towards equilibrium +because + + align:start position:0% +because + + + align:start position:0% +because +nature F salum + + align:start position:0% +nature F salum + + + align:start position:0% +nature F salum +but uh nature usually likes to go + + align:start position:0% +but uh nature usually likes to go + + + align:start position:0% +but uh nature usually likes to go +towards equilibrium + + align:start position:0% + + + + align:start position:0% + +and so there is a spontaneous uh + + align:start position:0% +and so there is a spontaneous uh + + + align:start position:0% +and so there is a spontaneous uh +tendency so there is a natural law that + + align:start position:0% +tendency so there is a natural law that + + + align:start position:0% +tendency so there is a natural law that +pushes a Pro system to uh even out or + + align:start position:0% + + + + align:start position:0% + +redistribute the energy load you can + + align:start position:0% +redistribute the energy load you can + + + align:start position:0% +redistribute the energy load you can +interpret these u in + + align:start position:0% +interpret these u in + + + align:start position:0% +interpret these u in +histograms as uh the probabilities you + + align:start position:0% +histograms as uh the probabilities you + + + align:start position:0% +histograms as uh the probabilities you +see is written here measure the degree + + align:start position:0% +see is written here measure the degree + + + align:start position:0% +see is written here measure the degree +of involvement + + align:start position:0% +of involvement + + + align:start position:0% +of involvement +of level of level EJ in sharing the mean + + align:start position:0% +of level of level EJ in sharing the mean + + + align:start position:0% +of level of level EJ in sharing the mean +energy + + align:start position:0% +energy + + + align:start position:0% +energy +load you give some energy to the + + align:start position:0% +load you give some energy to the + + + align:start position:0% +load you give some energy to the +particle and the + + align:start position:0% +particle and the + + + align:start position:0% +particle and the +particle has to decide where to put it + + align:start position:0% +particle has to decide where to put it + + + align:start position:0% +particle has to decide where to put it +it can put it um in in translational + + align:start position:0% +it can put it um in in translational + + + align:start position:0% +it can put it um in in translational +mode but as we've seen here if the + + align:start position:0% +mode but as we've seen here if the + + + align:start position:0% +mode but as we've seen here if the +particle is confined the translational + + align:start position:0% +particle is confined the translational + + + align:start position:0% +particle is confined the translational +modes have this kind of energy levels so + + align:start position:0% +modes have this kind of energy levels so + + + align:start position:0% +modes have this kind of energy levels so +how much energy do I put in this mode + + align:start position:0% +how much energy do I put in this mode + + + align:start position:0% +how much energy do I put in this mode +and how much in that and how much in + + align:start position:0% +and how much in that and how much in + + + align:start position:0% +and how much in that and how much in +that if the particle also has a internal + + align:start position:0% +that if the particle also has a internal + + + align:start position:0% +that if the particle also has a internal +structure uh so for example it could uh + + align:start position:0% +structure uh so for example it could uh + + + align:start position:0% +structure uh so for example it could uh +vibrate or if it if it has a structure + + align:start position:0% +vibrate or if it if it has a structure + + + align:start position:0% +vibrate or if it if it has a structure +so that it can + + align:start position:0% +so that it can + + + align:start position:0% +so that it can +rotate can put also you get additional + + align:start position:0% +rotate can put also you get additional + + + align:start position:0% +rotate can put also you get additional +modes uh rotational + + align:start position:0% +modes uh rotational + + + align:start position:0% +modes uh rotational +modes uh and then you have electron iic + + align:start position:0% +modes uh and then you have electron iic + + + align:start position:0% +modes uh and then you have electron iic +modes all right so the particle uh has + + align:start position:0% +modes all right so the particle uh has + + + align:start position:0% +modes all right so the particle uh has +to + + align:start position:0% +to + + + align:start position:0% +to +decide how to distribute and uh uh + + align:start position:0% +decide how to distribute and uh uh + + + align:start position:0% +decide how to distribute and uh uh +distribute + + align:start position:0% +distribute + + + align:start position:0% +distribute +evenly so if it is + + align:start position:0% + + + + align:start position:0% + +unconstrained the the most even + + align:start position:0% +unconstrained the the most even + + + align:start position:0% +unconstrained the the most even +distribution is the maximum + + align:start position:0% +distribution is the maximum + + + align:start position:0% +distribution is the maximum +entropy the equilibrium one at + + align:start position:0% +entropy the equilibrium one at + + + align:start position:0% +entropy the equilibrium one at +equilibrium it will have distributed + + align:start position:0% +equilibrium it will have distributed + + + align:start position:0% +equilibrium it will have distributed +things so as to Max maximize the entropy + + align:start position:0% +things so as to Max maximize the entropy + + + align:start position:0% +things so as to Max maximize the entropy +so entropy also measures the uh degree + + align:start position:0% +so entropy also measures the uh degree + + + align:start position:0% +so entropy also measures the uh degree +of + + align:start position:0% + + + + align:start position:0% + +sharing the highest degree of sharing is + + align:start position:0% +sharing the highest degree of sharing is + + + align:start position:0% +sharing the highest degree of sharing is +achieved here and the natural phenomena + + align:start position:0% +achieved here and the natural phenomena + + + align:start position:0% +achieved here and the natural phenomena +are in common have in common the idea + + align:start position:0% +are in common have in common the idea + + + align:start position:0% +are in common have in common the idea +that there is a spontaneous tendency to + + align:start position:0% +that there is a spontaneous tendency to + + + align:start position:0% +that there is a spontaneous tendency to +uh uh share uh the energy as evenly + + align:start position:0% +uh uh share uh the energy as evenly + + + align:start position:0% +uh uh share uh the energy as evenly +possible as possible + + align:start position:0% +possible as possible + + + align:start position:0% +possible as possible +uh among the uh available energy + + align:start position:0% + + + + align:start position:0% + +levels + + align:start position:0% + + + + align:start position:0% + +so the question about Dynamics is how do + + align:start position:0% +so the question about Dynamics is how do + + + align:start position:0% +so the question about Dynamics is how do +this thing evolve in time and here I + + align:start position:0% +this thing evolve in time and here I + + + align:start position:0% +this thing evolve in time and here I +have a slide with a + + align:start position:0% +have a slide with a + + + align:start position:0% +have a slide with a +some uh animation hopefully it should + + align:start position:0% +some uh animation hopefully it should + + + align:start position:0% +some uh animation hopefully it should +work let's + + align:start position:0% + + + + align:start position:0% + +see yeah okay so for example I started + + align:start position:0% +see yeah okay so for example I started + + + align:start position:0% +see yeah okay so for example I started +from very close to uh zero entropy and + + align:start position:0% +from very close to uh zero entropy and + + + align:start position:0% +from very close to uh zero entropy and +this is a smooth transition in which uh + + align:start position:0% +this is a smooth transition in which uh + + + align:start position:0% +this is a smooth transition in which uh +the particle while keeping the energy + + align:start position:0% +the particle while keeping the energy + + + align:start position:0% +the particle while keeping the energy +constant redistributes the probabilities + + align:start position:0% +constant redistributes the probabilities + + + align:start position:0% +constant redistributes the probabilities +until it eventually achieves the stable + + align:start position:0% +until it eventually achieves the stable + + + align:start position:0% +until it eventually achieves the stable +equilibrium canonical + + align:start position:0% + + + + align:start position:0% + +distribution + + align:start position:0% +distribution + + + align:start position:0% +distribution +okay and also this one is another + + align:start position:0% +okay and also this one is another + + + align:start position:0% +okay and also this one is another +example + + align:start position:0% +example + + + align:start position:0% +example +started from an intermediate state with + + align:start position:0% +started from an intermediate state with + + + align:start position:0% +started from an intermediate state with +two + + align:start position:0% +two + + + align:start position:0% +two +initially uh full um energy levels and + + align:start position:0% +initially uh full um energy levels and + + + align:start position:0% +initially uh full um energy levels and +the the other ones get + + align:start position:0% + + + + align:start position:0% + +filled until in the end you get to the + + align:start position:0% +filled until in the end you get to the + + + align:start position:0% +filled until in the end you get to the +same + + align:start position:0% + + + + align:start position:0% + +state I rescued + + align:start position:0% +state I rescued + + + align:start position:0% +state I rescued +these view graphs from U + + align:start position:0% +these view graphs from U + + + align:start position:0% +these view graphs from U +work that I had + + align:start position:0% + + + + align:start position:0% + +done for my PhD thesis + + align:start position:0% + + + + align:start position:0% + +here + + align:start position:0% + + + + align:start position:0% + +1981 to devise a an equation of motion + + align:start position:0% +1981 to devise a an equation of motion + + + align:start position:0% +1981 to devise a an equation of motion +that would take any probability + + align:start position:0% +that would take any probability + + + align:start position:0% +that would take any probability +distribution of this sort and + + align:start position:0% +distribution of this sort and + + + align:start position:0% +distribution of this sort and +evolves uh it smoothly towards a stable + + align:start position:0% +evolves uh it smoothly towards a stable + + + align:start position:0% +evolves uh it smoothly towards a stable +equilibrium + + align:start position:0% +equilibrium + + + align:start position:0% +equilibrium +and that's developed in the subject that + + align:start position:0% +and that's developed in the subject that + + + align:start position:0% +and that's developed in the subject that +um u i Now call it steepest entropy + + align:start position:0% +um u i Now call it steepest entropy + + + align:start position:0% +um u i Now call it steepest entropy +asent but also has to do with what I + + align:start position:0% +asent but also has to do with what I + + + align:start position:0% +asent but also has to do with what I +like to call the forlow of + + align:start position:0% +like to call the forlow of + + + align:start position:0% +like to call the forlow of +thermodynamics because essentially this + + align:start position:0% +thermodynamics because essentially this + + + align:start position:0% +thermodynamics because essentially this +kind of uh dynamical description of + + align:start position:0% +kind of uh dynamical description of + + + align:start position:0% +kind of uh dynamical description of +non-e equilibrium + + align:start position:0% +non-e equilibrium + + + align:start position:0% +non-e equilibrium +States is uh is is common of a large + + align:start position:0% +States is uh is is common of a large + + + align:start position:0% +States is uh is is common of a large +number of theories of on + + align:start position:0% +number of theories of on + + + align:start position:0% +number of theories of on +equilibrium there are some + + align:start position:0% +equilibrium there are some + + + align:start position:0% +equilibrium there are some +features + + align:start position:0% +features + + + align:start position:0% +features +uh and + + align:start position:0% +uh and + + + align:start position:0% +uh and +uh and there are some aspects some + + align:start position:0% +uh and there are some aspects some + + + align:start position:0% +uh and there are some aspects some +general aspects of this modeling + + align:start position:0% +general aspects of this modeling + + + align:start position:0% +general aspects of this modeling +uh + + align:start position:0% +uh + + + align:start position:0% +uh +ideas uh that are so uh common in spite + + align:start position:0% +ideas uh that are so uh common in spite + + + align:start position:0% +ideas uh that are so uh common in spite +of the different fields in which you + + align:start position:0% +of the different fields in which you + + + align:start position:0% +of the different fields in which you +find + + align:start position:0% +find + + + align:start position:0% +find +them uh uh that you can say that perhaps + + align:start position:0% +them uh uh that you can say that perhaps + + + align:start position:0% +them uh uh that you can say that perhaps +they + + align:start position:0% +they + + + align:start position:0% +they +represent uh another law + + align:start position:0% +represent uh another law + + + align:start position:0% +represent uh another law +of shouldn't say of nature but in our + + align:start position:0% +of shouldn't say of nature but in our + + + align:start position:0% +of shouldn't say of nature but in our +law another law of uh modeling nature + + align:start position:0% +law another law of uh modeling nature + + + align:start position:0% +law another law of uh modeling nature +correctly like the second law we have uh + + align:start position:0% +correctly like the second law we have uh + + + align:start position:0% +correctly like the second law we have uh +described as something that uh your + + align:start position:0% +described as something that uh your + + + align:start position:0% +described as something that uh your +model should not violate otherwise it is + + align:start position:0% +model should not violate otherwise it is + + + align:start position:0% +model should not violate otherwise it is +a bad model okay also the forth flow + + align:start position:0% +a bad model okay also the forth flow + + + align:start position:0% +a bad model okay also the forth flow +will be something that is similarly to + + align:start position:0% +will be something that is similarly to + + + align:start position:0% +will be something that is similarly to +be uh satisfied if your model has to + + align:start position:0% +be uh satisfied if your model has to + + + align:start position:0% +be uh satisfied if your model has to +provide a + + align:start position:0% +provide a + + + align:start position:0% +provide a +compatible description of how States + + align:start position:0% +compatible description of how States + + + align:start position:0% +compatible description of how States +evolve towards equilibrium uh in + + align:start position:0% +evolve towards equilibrium uh in + + + align:start position:0% +evolve towards equilibrium uh in +compatible with all we know + + align:start position:0% +compatible with all we know + + + align:start position:0% +compatible with all we know +about evidence of of physical + + align:start position:0% + + + + align:start position:0% + +reality well little more because we + + align:start position:0% +reality well little more because we + + + align:start position:0% +reality well little more because we +haven't done we haven't finished the yet + + align:start position:0% +haven't done we haven't finished the yet + + + align:start position:0% +haven't done we haven't finished the yet +with the particle in the + + align:start position:0% +with the particle in the + + + align:start position:0% +with the particle in the +Box + + align:start position:0% + + + + align:start position:0% + +um let me uh take it um start again from + + align:start position:0% +um let me uh take it um start again from + + + align:start position:0% +um let me uh take it um start again from +the partition function + + align:start position:0% +the partition function + + + align:start position:0% +the partition function +Q of the onedimensional + + align:start position:0% + + + + align:start position:0% + +case which is therefore this summation + + align:start position:0% +case which is therefore this summation + + + align:start position:0% +case which is therefore this summation +of e to the uh the energy levels over KT + + align:start position:0% +of e to the uh the energy levels over KT + + + align:start position:0% +of e to the uh the energy levels over KT +and here are the energy levels uh + + align:start position:0% +and here are the energy levels uh + + + align:start position:0% +and here are the energy levels uh +substituted directly so you see now in + + align:start position:0% +substituted directly so you see now in + + + align:start position:0% +substituted directly so you see now in +this expression what are the fixed the + + align:start position:0% +this expression what are the fixed the + + + align:start position:0% +this expression what are the fixed the +parameters I mean some are physical + + align:start position:0% +parameters I mean some are physical + + + align:start position:0% +parameters I mean some are physical +constants plank constant H uh bman + + align:start position:0% +constants plank constant H uh bman + + + align:start position:0% +constants plank constant H uh bman +constant KB m is the mass of your + + align:start position:0% +constant KB m is the mass of your + + + align:start position:0% +constant KB m is the mass of your +particle J is just the dummy variable in + + align:start position:0% +particle J is just the dummy variable in + + + align:start position:0% +particle J is just the dummy variable in +this summation there are only two + + align:start position:0% +this summation there are only two + + + align:start position:0% +this summation there are only two +parameters in this formula T which is + + align:start position:0% +parameters in this formula T which is + + + align:start position:0% +parameters in this formula T which is +the temperature and L which which is the + + align:start position:0% +the temperature and L which which is the + + + align:start position:0% +the temperature and L which which is the +side the size of of the box or the side + + align:start position:0% +side the size of of the box or the side + + + align:start position:0% +side the size of of the box or the side +of the + + align:start position:0% + + + + align:start position:0% + +box so Q is a function of two variables + + align:start position:0% +box so Q is a function of two variables + + + align:start position:0% +box so Q is a function of two variables +that means that as we like to do when we + + align:start position:0% +that means that as we like to do when we + + + align:start position:0% +that means that as we like to do when we +have functions we take the + + align:start position:0% +have functions we take the + + + align:start position:0% +have functions we take the +differentials so if I take the + + align:start position:0% +differentials so if I take the + + + align:start position:0% +differentials so if I take the +differential of the logarithm of this + + align:start position:0% +differential of the logarithm of this + + + align:start position:0% +differential of the logarithm of this +summation logar of + + align:start position:0% +summation logar of + + + align:start position:0% +summation logar of +q and u it takes a little while but uh + + align:start position:0% +q and u it takes a little while but uh + + + align:start position:0% +q and u it takes a little while but uh +you can do it that's just uh you can + + align:start position:0% +you can do it that's just uh you can + + + align:start position:0% +you can do it that's just uh you can +check + + align:start position:0% +check + + + align:start position:0% +check +um it can be written this + + align:start position:0% +um it can be written this + + + align:start position:0% +um it can be written this +way so of course it has a DT and a DL + + align:start position:0% +way so of course it has a DT and a DL + + + align:start position:0% +way so of course it has a DT and a DL +because the two variables are T and + + align:start position:0% + + + + align:start position:0% + +L uh so once you have done it you may + + align:start position:0% +L uh so once you have done it you may + + + align:start position:0% +L uh so once you have done it you may +say um that the coefficient that + + align:start position:0% +say um that the coefficient that + + + align:start position:0% +say um that the coefficient that +multiplies DT is equal to the derivative + + align:start position:0% +multiplies DT is equal to the derivative + + + align:start position:0% +multiplies DT is equal to the derivative +of what you of of of the log of + + align:start position:0% +of what you of of of the log of + + + align:start position:0% +of what you of of of the log of +Q with respect to T and so you obtain + + align:start position:0% +Q with respect to T and so you obtain + + + align:start position:0% +Q with respect to T and so you obtain +this + + align:start position:0% +this + + + align:start position:0% +this +relation and this other one is equal to + + align:start position:0% +relation and this other one is equal to + + + align:start position:0% +relation and this other one is equal to +the derivative of uh uh log of Q with + + align:start position:0% +the derivative of uh uh log of Q with + + + align:start position:0% +the derivative of uh uh log of Q with +respect to + + align:start position:0% +respect to + + + align:start position:0% +respect to +L actually notice that if since it's DL + + align:start position:0% +L actually notice that if since it's DL + + + align:start position:0% +L actually notice that if since it's DL +over L this is also you the derivative + + align:start position:0% +over L this is also you the derivative + + + align:start position:0% +over L this is also you the derivative +of the log of + + align:start position:0% +of the log of + + + align:start position:0% +of the log of +L so we can so we obtain that the + + align:start position:0% +L so we can so we obtain that the + + + align:start position:0% +L so we can so we obtain that the +derivative of log of Q over uh log of L + + align:start position:0% +derivative of log of Q over uh log of L + + + align:start position:0% +derivative of log of Q over uh log of L +is equal to e subi over + + align:start position:0% +is equal to e subi over + + + align:start position:0% +is equal to e subi over +KT now + + align:start position:0% + + + + align:start position:0% + +isab + + align:start position:0% + + + + align:start position:0% + +um I don't find it in this slide but it + + align:start position:0% + + + + align:start position:0% + +is is a + + align:start position:0% +is is a + + + align:start position:0% +is is a +by if you go a couple of slides earlier + + align:start position:0% +by if you go a couple of slides earlier + + + align:start position:0% +by if you go a couple of slides earlier +you find it and you should correct me if + + align:start position:0% +you find it and you should correct me if + + + align:start position:0% +you find it and you should correct me if +I'm writing it + + align:start position:0% + + + + align:start position:0% + +wrong isi should be the weighted sum on + + align:start position:0% +wrong isi should be the weighted sum on + + + align:start position:0% +wrong isi should be the weighted sum on +the + + align:start position:0% +the + + + align:start position:0% +the +probabilities of the energy + + align:start position:0% +probabilities of the energy + + + align:start position:0% +probabilities of the energy +levels of the single uh + + align:start position:0% +levels of the single uh + + + align:start position:0% +levels of the single uh +um uh + + align:start position:0% + + + + align:start position:0% + +Direction so essentially + + align:start position:0% +Direction so essentially + + + align:start position:0% +Direction so essentially +it's the uh it's the partial energy see + + align:start position:0% +it's the uh it's the partial energy see + + + align:start position:0% +it's the uh it's the partial energy see +the the the overall + + align:start position:0% +the the the overall + + + align:start position:0% +the the the overall +energy is equal to the sum of the + + align:start position:0% +energy is equal to the sum of the + + + align:start position:0% +energy is equal to the sum of the +energies that the particle has in the + + align:start position:0% +energies that the particle has in the + + + align:start position:0% +energies that the particle has in the +three + + align:start position:0% +three + + + align:start position:0% +three +directions it's like + + align:start position:0% +directions it's like + + + align:start position:0% +directions it's like +additive they are independent + + align:start position:0% +additive they are independent + + + align:start position:0% +additive they are independent +modes independent lives that the + + align:start position:0% +modes independent lives that the + + + align:start position:0% +modes independent lives that the +particle has in the three Direction okay + + align:start position:0% +particle has in the three Direction okay + + + align:start position:0% +particle has in the three Direction okay +so here we're watching it just Just One + + align:start position:0% +so here we're watching it just Just One + + + align:start position:0% +so here we're watching it just Just One +Direction + + align:start position:0% +Direction + + + align:start position:0% +Direction +okay then another formula that we + + align:start position:0% +okay then another formula that we + + + align:start position:0% +okay then another formula that we +had couple of slides ago is this + + align:start position:0% +had couple of slides ago is this + + + align:start position:0% +had couple of slides ago is this +one the one that I also wrote uh here + + align:start position:0% +one the one that I also wrote uh here + + + align:start position:0% +one the one that I also wrote uh here +for the free + + align:start position:0% + + + + align:start position:0% + +energy so if I take the differential of + + align:start position:0% +energy so if I take the differential of + + + align:start position:0% +energy so if I take the differential of +this + + align:start position:0% +this + + + align:start position:0% +this +one here is what I + + align:start position:0% +one here is what I + + + align:start position:0% +one here is what I +get again it takes a little bit of doing + + align:start position:0% +get again it takes a little bit of doing + + + align:start position:0% +get again it takes a little bit of doing +because I have to substit I have to take + + align:start position:0% +because I have to substit I have to take + + + align:start position:0% +because I have to substit I have to take +the differential of log of q but the + + align:start position:0% +the differential of log of q but the + + + align:start position:0% +the differential of log of q but the +differential of log of Q we just take + + align:start position:0% + + + + align:start position:0% + +it we just took it and so here it is we + + align:start position:0% +it we just took it and so here it is we + + + align:start position:0% +it we just took it and so here it is we +substitute it there this one cancels + + align:start position:0% +substitute it there this one cancels + + + align:start position:0% +substitute it there this one cancels +with one of of the minus one / t^ s that + + align:start position:0% +with one of of the minus one / t^ s that + + + align:start position:0% +with one of of the minus one / t^ s that +comes from the derivative of this and so + + align:start position:0% +comes from the derivative of this and so + + + align:start position:0% +comes from the derivative of this and so +here is what I'm left with Ds 1 / TDE + + align:start position:0% +here is what I'm left with Ds 1 / TDE + + + align:start position:0% +here is what I'm left with Ds 1 / TDE +plus something + + align:start position:0% + + + + align:start position:0% + +DL this is an ropy form of the + + align:start position:0% +DL this is an ropy form of the + + + align:start position:0% +DL this is an ropy form of the +fundamental relation for the stable + + align:start position:0% +fundamental relation for the stable + + + align:start position:0% +fundamental relation for the stable +equilibrium + + align:start position:0% + + + + align:start position:0% + +state so this is the Gibbs relation you + + align:start position:0% +state so this is the Gibbs relation you + + + align:start position:0% +state so this is the Gibbs relation you +like to put it in energy form you just + + align:start position:0% +like to put it in energy form you just + + + align:start position:0% +like to put it in energy form you just +solve for de and here is it it's de is + + align:start position:0% +solve for de and here is it it's de is + + + align:start position:0% +solve for de and here is it it's de is +minus + + align:start position:0% +minus + + + align:start position:0% +minus +TDS minus something + + align:start position:0% + + + + align:start position:0% + +DL now if + + align:start position:0% + + + + align:start position:0% + +you if you remember + + align:start position:0% +you if you remember + + + align:start position:0% +you if you remember +when we have a a sing a substance in the + + align:start position:0% +when we have a a sing a substance in the + + + align:start position:0% +when we have a a sing a substance in the +simple system model + + align:start position:0% +simple system model + + + align:start position:0% +simple system model +limit uh the Gibbs relation is that de + + align:start position:0% +limit uh the Gibbs relation is that de + + + align:start position:0% +limit uh the Gibbs relation is that de +is TDS minus + + align:start position:0% +is TDS minus + + + align:start position:0% +is TDS minus +pdv + + align:start position:0% +pdv + + + align:start position:0% +pdv +pdv okay volume is the parameter and + + align:start position:0% +pdv okay volume is the parameter and + + + align:start position:0% +pdv okay volume is the parameter and +pressure is the coefficient in the + + align:start position:0% +pressure is the coefficient in the + + + align:start position:0% +pressure is the coefficient in the +differential that measures uh the the + + align:start position:0% +differential that measures uh the the + + + align:start position:0% +differential that measures uh the the +partial of the energy with respect to + + align:start position:0% +partial of the energy with respect to + + + align:start position:0% +partial of the energy with respect to +volume at constant s all right so that + + align:start position:0% +volume at constant s all right so that + + + align:start position:0% +volume at constant s all right so that +prompts Us by just looking at this here + + align:start position:0% +prompts Us by just looking at this here + + + align:start position:0% +prompts Us by just looking at this here +we don't have volume because the volume + + align:start position:0% +we don't have volume because the volume + + + align:start position:0% +we don't have volume because the volume +there's no volume for this particle it + + align:start position:0% +there's no volume for this particle it + + + align:start position:0% +there's no volume for this particle it +is only the length of the Box the size + + align:start position:0% +is only the length of the Box the size + + + align:start position:0% +is only the length of the Box the size +of the box is the equivalent of the + + align:start position:0% +of the box is the equivalent of the + + + align:start position:0% +of the box is the equivalent of the +volume so we can + + align:start position:0% +volume so we can + + + align:start position:0% +volume so we can +Define the equivalent of a + + align:start position:0% + + + + align:start position:0% + +pressure I will call it don't know what + + align:start position:0% +pressure I will call it don't know what + + + align:start position:0% +pressure I will call it don't know what +name to to give but I will call it + + align:start position:0% +name to to give but I will call it + + + align:start position:0% +name to to give but I will call it +directional + + align:start position:0% + + + + align:start position:0% + +pressure it has dimensions of + + align:start position:0% + + + + align:start position:0% + +pressure and I + + align:start position:0% +pressure and I + + + align:start position:0% +pressure and I +say and I Define it uh as the partial + + align:start position:0% +say and I Define it uh as the partial + + + align:start position:0% +say and I Define it uh as the partial +the negative of the partial of the + + align:start position:0% +the negative of the partial of the + + + align:start position:0% +the negative of the partial of the +energy with respect to + + align:start position:0% +energy with respect to + + + align:start position:0% +energy with respect to +volume but + + align:start position:0% +volume but + + + align:start position:0% +volume but +done while changing + + align:start position:0% + + + + align:start position:0% + +only the One + + align:start position:0% +only the One + + + align:start position:0% +only the One +Direction so you see see since I have a + + align:start position:0% +Direction so you see see since I have a + + + align:start position:0% +Direction so you see see since I have a +box now this size this + + align:start position:0% +box now this size this + + + align:start position:0% +box now this size this +shape there are three different ways in + + align:start position:0% +shape there are three different ways in + + + align:start position:0% +shape there are three different ways in +which I can change the + + align:start position:0% +which I can change the + + + align:start position:0% +which I can change the +volume one is to uh keep L2 and L3 fixed + + align:start position:0% +volume one is to uh keep L2 and L3 fixed + + + align:start position:0% +volume one is to uh keep L2 and L3 fixed +and make L1 + + align:start position:0% +and make L1 + + + align:start position:0% +and make L1 +longer and then there are the other + + align:start position:0% +longer and then there are the other + + + align:start position:0% +longer and then there are the other +two okay so I'm changing the volume just + + align:start position:0% +two okay so I'm changing the volume just + + + align:start position:0% +two okay so I'm changing the volume just +by changing + + align:start position:0% +by changing + + + align:start position:0% +by changing +L1 that's the + + align:start position:0% +L1 that's the + + + align:start position:0% +L1 that's the +pressure assigned to Direction one + + align:start position:0% +pressure assigned to Direction one + + + align:start position:0% +pressure assigned to Direction one +how much how much the energy changes in + + align:start position:0% +how much how much the energy changes in + + + align:start position:0% +how much how much the energy changes in +the stable equilibrium at fixed s fixed + + align:start position:0% +the stable equilibrium at fixed s fixed + + + align:start position:0% +the stable equilibrium at fixed s fixed +L2 and L3 when I change + + align:start position:0% + + + + align:start position:0% + +L1 okay so you can also rewrite it this + + align:start position:0% + + + + align:start position:0% + +way and if you rewrite it this way + + align:start position:0% +way and if you rewrite it this way + + + align:start position:0% +way and if you rewrite it this way +because the volume I mean yeah I'll let + + align:start position:0% +because the volume I mean yeah I'll let + + + align:start position:0% +because the volume I mean yeah I'll let +you think about this this very + + align:start position:0% +you think about this this very + + + align:start position:0% +you think about this this very +simple um all right so the partial of e + + align:start position:0% +simple um all right so the partial of e + + + align:start position:0% +simple um all right so the partial of e +with respect to the the the logarithm of + + align:start position:0% +with respect to the the the logarithm of + + + align:start position:0% +with respect to the the the logarithm of +L1 is obtained + + align:start position:0% +L1 is obtained + + + align:start position:0% +L1 is obtained +here because from this + + align:start position:0% +here because from this + + + align:start position:0% +here because from this +differential this + + align:start position:0% +differential this + + + align:start position:0% +differential this +coefficient minus 2 + + align:start position:0% +coefficient minus 2 + + + align:start position:0% +coefficient minus 2 +e is exactly the partial of e with + + align:start position:0% +e is exactly the partial of e with + + + align:start position:0% +e is exactly the partial of e with +respect to the logarithm d l over L is + + align:start position:0% +respect to the logarithm d l over L is + + + align:start position:0% +respect to the logarithm d l over L is +the logarithm of + + align:start position:0% +the logarithm of + + + align:start position:0% +the logarithm of +L okay so here what we find is that uh + + align:start position:0% +L okay so here what we find is that uh + + + align:start position:0% +L okay so here what we find is that uh +that pressure is two e over + + align:start position:0% + + + + align:start position:0% + +V that is the closest we can get for the + + align:start position:0% +V that is the closest we can get for the + + + align:start position:0% +V that is the closest we can get for the +moment without additional assumption so + + align:start position:0% +moment without additional assumption so + + + align:start position:0% +moment without additional assumption so +we found that + + align:start position:0% +we found that + + + align:start position:0% +we found that +P or + + align:start position:0% +P or + + + align:start position:0% +P or +Pi say + + align:start position:0% +Pi say + + + align:start position:0% +Pi say +one times the + + align:start position:0% +one times the + + + align:start position:0% +one times the +volume is that the + + align:start position:0% +volume is that the + + + align:start position:0% +volume is that the +volume yeah is equal to 2 e + + align:start position:0% +volume yeah is equal to 2 e + + + align:start position:0% +volume yeah is equal to 2 e +i Pi + + align:start position:0% + + + + align:start position:0% + +I in a + + align:start position:0% +I in a + + + align:start position:0% +I in a +moment if you add the information that + + align:start position:0% +moment if you add the information that + + + align:start position:0% +moment if you add the information that +uh eventually we will have that e subi + + align:start position:0% +uh eventually we will have that e subi + + + align:start position:0% +uh eventually we will have that e subi +is equal to + + align:start position:0% +is equal to + + + align:start position:0% +is equal to +one2 of + + align:start position:0% + + + + align:start position:0% + +KT and you substitute up + + align:start position:0% +KT and you substitute up + + + align:start position:0% +KT and you substitute up +there you find + + align:start position:0% +there you find + + + align:start position:0% +there you find +that Pi V equals the two cancels equals + + align:start position:0% +that Pi V equals the two cancels equals + + + align:start position:0% +that Pi V equals the two cancels equals +KT K remember is the gas constant n r so + + align:start position:0% +KT K remember is the gas constant n r so + + + align:start position:0% +KT K remember is the gas constant n r so +you found that Pi V equals + + align:start position:0% + + + + align:start position:0% + +nrt that's the ideal gas equation of + + align:start position:0% +nrt that's the ideal gas equation of + + + align:start position:0% +nrt that's the ideal gas equation of +state it requires though this step which + + align:start position:0% +state it requires though this step which + + + align:start position:0% +state it requires though this step which +we didn't we don't get yet and it's not + + align:start position:0% +we didn't we don't get yet and it's not + + + align:start position:0% +we didn't we don't get yet and it's not +always but but at this stage without + + align:start position:0% +always but but at this stage without + + + align:start position:0% +always but but at this stage without +assumptions about uh uh how large the + + align:start position:0% +assumptions about uh uh how large the + + + align:start position:0% +assumptions about uh uh how large the +temperature + + align:start position:0% +temperature + + + align:start position:0% +temperature +is which is something that we we require + + align:start position:0% +is which is something that we we require + + + align:start position:0% +is which is something that we we require +to discuss to get to this result we have + + align:start position:0% +to discuss to get to this result we have + + + align:start position:0% +to discuss to get to this result we have +obtained essentially the equivalent the + + align:start position:0% +obtained essentially the equivalent the + + + align:start position:0% +obtained essentially the equivalent the +the equation of state and of course you + + align:start position:0% +the equation of state and of course you + + + align:start position:0% +the equation of state and of course you +have one such uh equation of State for + + align:start position:0% +have one such uh equation of State for + + + align:start position:0% +have one such uh equation of State for +each + + align:start position:0% +each + + + align:start position:0% +each +Direction you have you may have energy + + align:start position:0% +Direction you have you may have energy + + + align:start position:0% +Direction you have you may have energy +in uh in the X Y and Z Direction and so + + align:start position:0% +in uh in the X Y and Z Direction and so + + + align:start position:0% +in uh in the X Y and Z Direction and so +you have these directional pressures so + + align:start position:0% +you have these directional pressures so + + + align:start position:0% +you have these directional pressures so +you have three such relations + + align:start position:0% + + + + align:start position:0% + +here you also find that the since the + + align:start position:0% +here you also find that the since the + + + align:start position:0% +here you also find that the since the +energy sums I mean is additive + + align:start position:0% +energy sums I mean is additive + + + align:start position:0% +energy sums I mean is additive +the energy of the three directions adds + + align:start position:0% +the energy of the three directions adds + + + align:start position:0% +the energy of the three directions adds +up to the overall energy of your + + align:start position:0% +up to the overall energy of your + + + align:start position:0% +up to the overall energy of your +particle this relation between energy + + align:start position:0% +particle this relation between energy + + + align:start position:0% +particle this relation between energy +and pressures so you can also be written + + align:start position:0% +and pressures so you can also be written + + + align:start position:0% +and pressures so you can also be written +as the sum of these three uh + + align:start position:0% + + + + align:start position:0% + +pressures times V + + align:start position:0% + + + + align:start position:0% + +/2 + + align:start position:0% +/2 + + + align:start position:0% +/2 +and from the fact that the energy sums I + + align:start position:0% +and from the fact that the energy sums I + + + align:start position:0% +and from the fact that the energy sums I +can + + align:start position:0% + + + + align:start position:0% + +also uh take the if I take the + + align:start position:0% +also uh take the if I take the + + + align:start position:0% +also uh take the if I take the +differential of + + align:start position:0% + + + + align:start position:0% + +these so de is equal to the sum of the + + align:start position:0% +these so de is equal to the sum of the + + + align:start position:0% +these so de is equal to the sum of the +DI de I but the expressions for the de I + + align:start position:0% +DI de I but the expressions for the de I + + + align:start position:0% +DI de I but the expressions for the de I +is is here so the Gibs uh relations for + + align:start position:0% +is is here so the Gibs uh relations for + + + align:start position:0% +is is here so the Gibs uh relations for +the various directions are here I can + + align:start position:0% +the various directions are here I can + + + align:start position:0% +the various directions are here I can +sum them up to get the overall Gibs + + align:start position:0% +sum them up to get the overall Gibs + + + align:start position:0% +sum them up to get the overall Gibs +relation for my particle in the Box and + + align:start position:0% +relation for my particle in the Box and + + + align:start position:0% +relation for my particle in the Box and +so I have the equal + + align:start position:0% +so I have the equal + + + align:start position:0% +so I have the equal +TDS and instead of + + align:start position:0% +TDS and instead of + + + align:start position:0% +TDS and instead of +pdv we have three contributions one for + + align:start position:0% +pdv we have three contributions one for + + + align:start position:0% +pdv we have three contributions one for +each + + align:start position:0% + + + + align:start position:0% + +Direction so this is in general the + + align:start position:0% +Direction so this is in general the + + + align:start position:0% +Direction so this is in general the +gives a relation for the particle in the + + align:start position:0% +gives a relation for the particle in the + + + align:start position:0% +gives a relation for the particle in the +box and it has it requires three + + align:start position:0% +box and it has it requires three + + + align:start position:0% +box and it has it requires three +pressures + + align:start position:0% + + + + align:start position:0% + +now we can uh uh make an observation + + align:start position:0% +now we can uh uh make an observation + + + align:start position:0% +now we can uh uh make an observation +that + + align:start position:0% + + + + align:start position:0% + +uh the partition + + align:start position:0% + + + + align:start position:0% + +function that we now recognized the the + + align:start position:0% +function that we now recognized the the + + + align:start position:0% +function that we now recognized the the +role + + align:start position:0% +role + + + align:start position:0% +role +uh is a + + align:start position:0% +uh is a + + + align:start position:0% +uh is a +summation okay so is a + + align:start position:0% +summation okay so is a + + + align:start position:0% +summation okay so is a +summation of various terms you can + + align:start position:0% +summation of various terms you can + + + align:start position:0% +summation of various terms you can +uh think think + + align:start position:0% + + + + align:start position:0% + +of a + + align:start position:0% + + + + align:start position:0% + +summation + + align:start position:0% + + + + align:start position:0% + +as the various terms consider them as a + + align:start position:0% +as the various terms consider them as a + + + align:start position:0% +as the various terms consider them as a +the terms in a histogram and then the + + align:start position:0% +the terms in a histogram and then the + + + align:start position:0% +the terms in a histogram and then the +summation is the is the area so this is + + align:start position:0% +summation is the is the area so this is + + + align:start position:0% +summation is the is the area so this is +like the first term like from 0er to one + + align:start position:0% +like the first term like from 0er to one + + + align:start position:0% +like the first term like from 0er to one +and from from here to two and three and + + align:start position:0% +and from from here to two and three and + + + align:start position:0% +and from from here to two and three and +so + + align:start position:0% + + + + align:start position:0% + +on and so the summation + + align:start position:0% +on and so the summation + + + align:start position:0% +on and so the summation +gives you is essentially the area uh and + + align:start position:0% +gives you is essentially the area uh and + + + align:start position:0% +gives you is essentially the area uh and +this is the value of the element in the + + align:start position:0% +this is the value of the element in the + + + align:start position:0% +this is the value of the element in the +sum + + align:start position:0% +sum + + + align:start position:0% +sum +okay the idea here is that you sometimes + + align:start position:0% +okay the idea here is that you sometimes + + + align:start position:0% +okay the idea here is that you sometimes +can approximate this + + align:start position:0% +can approximate this + + + align:start position:0% +can approximate this +summation as the integral of a + + align:start position:0% +summation as the integral of a + + + align:start position:0% +summation as the integral of a +curve and that approximation is + + align:start position:0% +curve and that approximation is + + + align:start position:0% +curve and that approximation is +good when the error that you make these + + align:start position:0% +good when the error that you make these + + + align:start position:0% +good when the error that you make these +differences here become small + + align:start position:0% +differences here become small + + + align:start position:0% +differences here become small +so this is the + + align:start position:0% + + + + align:start position:0% + +idea it + + align:start position:0% +idea it + + + align:start position:0% +idea it +requires that U this these things be + + align:start position:0% +requires that U this these things be + + + align:start position:0% +requires that U this these things be +small uh somehow and that condition is + + align:start position:0% +small uh somehow and that condition is + + + align:start position:0% +small uh somehow and that condition is +written here it means that this um + + align:start position:0% +written here it means that this um + + + align:start position:0% +written here it means that this um +combination of terms must be smaller + + align:start position:0% +combination of terms must be smaller + + + align:start position:0% +combination of terms must be smaller +than one this is an + + align:start position:0% +than one this is an + + + align:start position:0% +than one this is an +dimensionless uh number which contains + + align:start position:0% +dimensionless uh number which contains + + + align:start position:0% +dimensionless uh number which contains +temperature and the square of the side + + align:start position:0% +temperature and the square of the side + + + align:start position:0% +temperature and the square of the side +and it has to be small if this is + + align:start position:0% +and it has to be small if this is + + + align:start position:0% +and it has to be small if this is +small you can approximate the summation + + align:start position:0% +small you can approximate the summation + + + align:start position:0% +small you can approximate the summation +with an integral and then this is a kind + + align:start position:0% +with an integral and then this is a kind + + + align:start position:0% +with an integral and then this is a kind +of integral that can be done because + + align:start position:0% +of integral that can be done because + + + align:start position:0% +of integral that can be done because +it's an integral from 0 to + + align:start position:0% +it's an integral from 0 to + + + align:start position:0% +it's an integral from 0 to +infinity and here is the + + align:start position:0% + + + + align:start position:0% + +result and this is the partition + + align:start position:0% +result and this is the partition + + + align:start position:0% +result and this is the partition +function for One Direction if you + + align:start position:0% +function for One Direction if you + + + align:start position:0% +function for One Direction if you +multiply the partition functions for the + + align:start position:0% +multiply the partition functions for the + + + align:start position:0% +multiply the partition functions for the +various + + align:start position:0% + + + + align:start position:0% + +directions uh so you must multiply the + + align:start position:0% +directions uh so you must multiply the + + + align:start position:0% +directions uh so you must multiply the +three you get the partition function for + + align:start position:0% +three you get the partition function for + + + align:start position:0% +three you get the partition function for +the overall particle in the + + align:start position:0% +the overall particle in the + + + align:start position:0% +the overall particle in the +box and + + align:start position:0% + + + + align:start position:0% + +uh you see here I have L uh + + align:start position:0% +uh you see here I have L uh + + + align:start position:0% +uh you see here I have L uh +I it's + + align:start position:0% +I it's + + + align:start position:0% +I it's +squared uh but actually + + align:start position:0% +squared uh but actually + + + align:start position:0% +squared uh but actually +it's to the 1/2 so you can take it + + align:start position:0% +it's to the 1/2 so you can take it + + + align:start position:0% +it's to the 1/2 so you can take it +outside + + align:start position:0% +outside + + + align:start position:0% +outside +also and when you multiply the three of + + align:start position:0% +also and when you multiply the three of + + + align:start position:0% +also and when you multiply the three of +them it becomes L1 * L2 * L3 which is + + align:start position:0% +them it becomes L1 * L2 * L3 which is + + + align:start position:0% +them it becomes L1 * L2 * L3 which is +the + + align:start position:0% +the + + + align:start position:0% +the +volume of the + + align:start position:0% +volume of the + + + align:start position:0% +volume of the +box and so the partition function also + + align:start position:0% +box and so the partition function also + + + align:start position:0% +box and so the partition function also +here is a q to the + + align:start position:0% +here is a q to the + + + align:start position:0% +here is a q to the +2/3 but it's to the three halfes so you + + align:start position:0% +2/3 but it's to the three halfes so you + + + align:start position:0% +2/3 but it's to the three halfes so you +can take the V outside so essentially + + align:start position:0% +can take the V outside so essentially + + + align:start position:0% +can take the V outside so essentially +this says that the overall partition + + align:start position:0% +this says that the overall partition + + + align:start position:0% +this says that the overall partition +function depends on the volume + + align:start position:0% +function depends on the volume + + + align:start position:0% +function depends on the volume +only essentially in this limit you are + + align:start position:0% +only essentially in this limit you are + + + align:start position:0% +only essentially in this limit you are +uh losing the um + + align:start position:0% +uh losing the um + + + align:start position:0% +uh losing the um +effect of the details of the shape of + + align:start position:0% +effect of the details of the shape of + + + align:start position:0% +effect of the details of the shape of +the Box what + + align:start position:0% +the Box what + + + align:start position:0% +the Box what +counts is just the product of the three + + align:start position:0% +counts is just the product of the three + + + align:start position:0% +counts is just the product of the three +which is the + + align:start position:0% + + + + align:start position:0% + +volume uh in + + align:start position:0% +volume uh in + + + align:start position:0% +volume uh in +fact in that limit + + align:start position:0% +fact in that limit + + + align:start position:0% +fact in that limit +uh if you if you take the formulas we + + align:start position:0% +uh if you if you take the formulas we + + + align:start position:0% +uh if you if you take the formulas we +have up up here for say for the energy e + + align:start position:0% +have up up here for say for the energy e + + + align:start position:0% +have up up here for say for the energy e +subi you have to take uh the log the + + align:start position:0% +subi you have to take uh the log the + + + align:start position:0% +subi you have to take uh the log the +partial of the logarithm with respect to + + align:start position:0% +partial of the logarithm with respect to + + + align:start position:0% +partial of the logarithm with respect to +T well here is Q take the + + align:start position:0% +T well here is Q take the + + + align:start position:0% +T well here is Q take the +logarithm with respect to + + align:start position:0% +logarithm with respect to + + + align:start position:0% +logarithm with respect to +T it's just 12 time + + align:start position:0% +T it's just 12 time + + + align:start position:0% +T it's just 12 time +KT that's the + + align:start position:0% + + + + align:start position:0% + +result and + + align:start position:0% +result and + + + align:start position:0% +result and +therefore and is equal in all directions + + align:start position:0% +therefore and is equal in all directions + + + align:start position:0% +therefore and is equal in all directions +this is so-called equip + + align:start position:0% +this is so-called equip + + + align:start position:0% +this is so-called equip +partition theorem uh + + align:start position:0% +partition theorem uh + + + align:start position:0% +partition theorem uh +the + + align:start position:0% +the + + + align:start position:0% +the +uh the particle has decided in this + + align:start position:0% +uh the particle has decided in this + + + align:start position:0% +uh the particle has decided in this +limit to + + align:start position:0% +limit to + + + align:start position:0% +limit to +distribute equally the energy in the + + align:start position:0% +distribute equally the energy in the + + + align:start position:0% +distribute equally the energy in the +three translational + + align:start position:0% +three translational + + + align:start position:0% +three translational +modes and each one gets a half of KT + + align:start position:0% + + + + align:start position:0% + +meaning that since the energy of the + + align:start position:0% +meaning that since the energy of the + + + align:start position:0% +meaning that since the energy of the +particle is the sum of the energies of + + align:start position:0% +particle is the sum of the energies of + + + align:start position:0% +particle is the sum of the energies of +the three + + align:start position:0% +the three + + + align:start position:0% +the three +directions e is equal to three halves of + + align:start position:0% + + + + align:start position:0% + +KT this a structureless + + align:start position:0% +KT this a structureless + + + align:start position:0% +KT this a structureless +particle and the so the specific heat + + align:start position:0% +particle and the so the specific heat + + + align:start position:0% +particle and the so the specific heat +which is the partial of e with respect + + align:start position:0% +which is the partial of e with respect + + + align:start position:0% +which is the partial of e with respect +to T is + + align:start position:0% +to T is + + + align:start position:0% +to T is +three2 K of the bement constant + + align:start position:0% + + + + align:start position:0% + +also these pressures become all uh equal + + align:start position:0% +also these pressures become all uh equal + + + align:start position:0% +also these pressures become all uh equal +to one + + align:start position:0% + + + + align:start position:0% + +another so if I take the Gibs relation + + align:start position:0% +another so if I take the Gibs relation + + + align:start position:0% +another so if I take the Gibs relation +and these pies are equal to one + + align:start position:0% +and these pies are equal to one + + + align:start position:0% +and these pies are equal to one +another uh I can write it this + + align:start position:0% +another uh I can write it this + + + align:start position:0% +another uh I can write it this +way and uh so I get uh uh so these three + + align:start position:0% +way and uh so I get uh uh so these three + + + align:start position:0% +way and uh so I get uh uh so these three +terms becomes + + align:start position:0% +terms becomes + + + align:start position:0% +terms becomes +KT which is here times the sum of the L + + align:start position:0% +KT which is here times the sum of the L + + + align:start position:0% +KT which is here times the sum of the L +over L this is the sum of the log of the + + align:start position:0% +over L this is the sum of the log of the + + + align:start position:0% +over L this is the sum of the log of the +of the logarithms so the it's the + + align:start position:0% +of the logarithms so the it's the + + + align:start position:0% +of the logarithms so the it's the +derivative of uh the volume over the + + align:start position:0% +derivative of uh the volume over the + + + align:start position:0% +derivative of uh the volume over the +volume it's D of log of + + align:start position:0% + + + + align:start position:0% + +v and so we have the GI + + align:start position:0% +v and so we have the GI + + + align:start position:0% +v and so we have the GI +relation but now if if we take the G + + align:start position:0% +relation but now if if we take the G + + + align:start position:0% +relation but now if if we take the G +relation and uh remember that what + + align:start position:0% +relation and uh remember that what + + + align:start position:0% +relation and uh remember that what +multiplies DV is what we call + + align:start position:0% +multiplies DV is what we call + + + align:start position:0% +multiplies DV is what we call +pressure here we find that therefore the + + align:start position:0% +pressure here we find that therefore the + + + align:start position:0% +pressure here we find that therefore the +pressure of the particle in the box is + + align:start position:0% +pressure of the particle in the box is + + + align:start position:0% +pressure of the particle in the box is +KT over V so we get PV is equal + + align:start position:0% +KT over V so we get PV is equal + + + align:start position:0% +KT over V so we get PV is equal +KT which is theal gas + + align:start position:0% + + + + align:start position:0% + +law we also get of course the expression + + align:start position:0% +law we also get of course the expression + + + align:start position:0% +law we also get of course the expression +for the entropy + + align:start position:0% + + + + align:start position:0% + +which is a function of temperature which + + align:start position:0% +which is a function of temperature which + + + align:start position:0% +which is a function of temperature which +can be written as a function of + + align:start position:0% +can be written as a function of + + + align:start position:0% +can be written as a function of +temperature and volume + + align:start position:0% +temperature and volume + + + align:start position:0% +temperature and volume +only so we lost uh the information about + + align:start position:0% +only so we lost uh the information about + + + align:start position:0% +only so we lost uh the information about +the need to uh know the details of the + + align:start position:0% +the need to uh know the details of the + + + align:start position:0% +the need to uh know the details of the +box so that means that in that limit and + + align:start position:0% +box so that means that in that limit and + + + align:start position:0% +box so that means that in that limit and +this limit uh this condition that this + + align:start position:0% +this limit uh this condition that this + + + align:start position:0% +this limit uh this condition that this +is small can also be uh written this + + align:start position:0% +is small can also be uh written this + + + align:start position:0% +is small can also be uh written this +way that the temperature if you fix the + + align:start position:0% +way that the temperature if you fix the + + + align:start position:0% +way that the temperature if you fix the +volume it means that the temperature + + align:start position:0% +volume it means that the temperature + + + align:start position:0% +volume it means that the temperature +must be + + align:start position:0% +must be + + + align:start position:0% +must be +big enough so + + align:start position:0% +big enough so + + + align:start position:0% +big enough so +that these constants divided by the + + align:start position:0% +that these constants divided by the + + + align:start position:0% +that these constants divided by the +volume to the + + align:start position:0% + + + + align:start position:0% + +2/3 uh so that the temperature is much + + align:start position:0% +2/3 uh so that the temperature is much + + + align:start position:0% +2/3 uh so that the temperature is much +greater than this + + align:start position:0% + + + + align:start position:0% + +number or you could also put it + + align:start position:0% +number or you could also put it + + + align:start position:0% +number or you could also put it +differently if you fix the temperature + + align:start position:0% +differently if you fix the temperature + + + align:start position:0% +differently if you fix the temperature +you need the volume to be big + + align:start position:0% +you need the volume to be big + + + align:start position:0% +you need the volume to be big +enough the system must be diluted enough + + align:start position:0% +enough the system must be diluted enough + + + align:start position:0% +enough the system must be diluted enough +so in these + + align:start position:0% + + + + align:start position:0% + +limits + + align:start position:0% +limits + + + align:start position:0% +limits +um we find the ideal gas law and we find + + align:start position:0% +um we find the ideal gas law and we find + + + align:start position:0% +um we find the ideal gas law and we find +uh that + + align:start position:0% +uh that + + + align:start position:0% +uh that +the box of the same + + align:start position:0% +the box of the same + + + align:start position:0% +the box of the same +volume uh it could be very many + + align:start position:0% +volume uh it could be very many + + + align:start position:0% +volume uh it could be very many +different shapes have uh can have the + + align:start position:0% +different shapes have uh can have the + + + align:start position:0% +different shapes have uh can have the +same volume they all have the same + + align:start position:0% +same volume they all have the same + + + align:start position:0% +same volume they all have the same +properties that's why + + align:start position:0% + + + + align:start position:0% + +uh in most practical situations this uh + + align:start position:0% +uh in most practical situations this uh + + + align:start position:0% +uh in most practical situations this uh +uh since this is + + align:start position:0% +uh since this is + + + align:start position:0% +uh since this is +satisfied except when you go to very low + + align:start position:0% +satisfied except when you go to very low + + + align:start position:0% +satisfied except when you go to very low +temperatures that's why we typically use + + align:start position:0% +temperatures that's why we typically use + + + align:start position:0% +temperatures that's why we typically use +just the volume as + + align:start position:0% +just the volume as + + + align:start position:0% +just the volume as +parameter because otherwise you would + + align:start position:0% +parameter because otherwise you would + + + align:start position:0% +parameter because otherwise you would +say all right you said the beginning you + + align:start position:0% +say all right you said the beginning you + + + align:start position:0% +say all right you said the beginning you +need to put the parameters in the + + align:start position:0% +need to put the parameters in the + + + align:start position:0% +need to put the parameters in the +fundamental relation but then you end up + + align:start position:0% +fundamental relation but then you end up + + + align:start position:0% +fundamental relation but then you end up +always putting only volume why well + + align:start position:0% +always putting only volume why well + + + align:start position:0% +always putting only volume why well +here's the reason because for most + + align:start position:0% +here's the reason because for most + + + align:start position:0% +here's the reason because for most +practical situation but not for small + + align:start position:0% +practical situation but not for small + + + align:start position:0% +practical situation but not for small +systems + + align:start position:0% +systems + + + align:start position:0% +systems +uh volume is all that + + align:start position:0% + + + + align:start position:0% + +counts + + align:start position:0% +counts + + + align:start position:0% +counts +okay so + + align:start position:0% +okay so + + + align:start position:0% +okay so +uh just a couple of + + align:start position:0% +uh just a couple of + + + align:start position:0% +uh just a couple of +minutes uh we are left uh I want to + + align:start position:0% +minutes uh we are left uh I want to + + + align:start position:0% +minutes uh we are left uh I want to +introduce this idea which is going to be + + align:start position:0% +introduce this idea which is going to be + + + align:start position:0% +introduce this idea which is going to be +our next step + + align:start position:0% + + + + align:start position:0% + +remember that we talked + + align:start position:0% +remember that we talked + + + align:start position:0% +remember that we talked +about the gas uh + + align:start position:0% +about the gas uh + + + align:start position:0% +about the gas uh +State uh as one in which the particles + + align:start position:0% +State uh as one in which the particles + + + align:start position:0% +State uh as one in which the particles +spend most of their times distant from + + align:start position:0% +spend most of their times distant from + + + align:start position:0% +spend most of their times distant from +one another in spite of their colliding + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +uh so in + + align:start position:0% +uh so in + + + align:start position:0% +uh so in +the ideal + + align:start position:0% +the ideal + + + align:start position:0% +the ideal +gas Gibbs Dalton + + align:start position:0% +gas Gibbs Dalton + + + align:start position:0% +gas Gibbs Dalton +mixture of Ideal + + align:start position:0% +mixture of Ideal + + + align:start position:0% +mixture of Ideal +gases we found that essentially the + + align:start position:0% +gases we found that essentially the + + + align:start position:0% +gases we found that essentially the +particles live in the space without + + align:start position:0% +particles live in the space without + + + align:start position:0% +particles live in the space without +seeing each other except when they + + align:start position:0% + + + + align:start position:0% + +Collide and + + align:start position:0% +Collide and + + + align:start position:0% +Collide and +uh and that results to the + + align:start position:0% +uh and that results to the + + + align:start position:0% +uh and that results to the +fact that the entropy of mixing + + align:start position:0% + + + + align:start position:0% + +is the only + + align:start position:0% +is the only + + + align:start position:0% +is the only +effect uh that results upon mixing you + + align:start position:0% +effect uh that results upon mixing you + + + align:start position:0% +effect uh that results upon mixing you +mix + + align:start position:0% +mix + + + align:start position:0% +mix +gases at given uh the spontaneous + + align:start position:0% +gases at given uh the spontaneous + + + align:start position:0% +gases at given uh the spontaneous +process the temperature doesn't change + + align:start position:0% +process the temperature doesn't change + + + align:start position:0% +process the temperature doesn't change +the pressure doesn't + + align:start position:0% + + + + align:start position:0% + +change and the only thing that changes + + align:start position:0% +change and the only thing that changes + + + align:start position:0% +change and the only thing that changes +is the entropy is the mixing uh + + align:start position:0% + + + + align:start position:0% + +now we need + + align:start position:0% +now we need + + + align:start position:0% +now we need +to Define also an ideal behavior for + + align:start position:0% +to Define also an ideal behavior for + + + align:start position:0% +to Define also an ideal behavior for +liquid phase now in liquid phase the + + align:start position:0% +liquid phase now in liquid phase the + + + align:start position:0% +liquid phase now in liquid phase the +particles do see each other actually + + align:start position:0% +particles do see each other actually + + + align:start position:0% +particles do see each other actually +they live most of the times close to one + + align:start position:0% +they live most of the times close to one + + + align:start position:0% +they live most of the times close to one +another so close + + align:start position:0% +another so close + + + align:start position:0% +another so close +to uh where this um um + + align:start position:0% + + + + align:start position:0% + +intermolecular potential has a min + + align:start position:0% +intermolecular potential has a min + + + align:start position:0% +intermolecular potential has a min +so for them that is + + align:start position:0% + + + + align:start position:0% + +important + + align:start position:0% +important + + + align:start position:0% +important +however we're going to Define an ideal + + align:start position:0% +however we're going to Define an ideal + + + align:start position:0% +however we're going to Define an ideal +solution Behavior one in + + align:start position:0% + + + + align:start position:0% + +which uh the + + align:start position:0% +which uh the + + + align:start position:0% +which uh the +curves for the interaction + + align:start position:0% +curves for the interaction + + + align:start position:0% +curves for the interaction +between uh equal + + align:start position:0% +between uh equal + + + align:start position:0% +between uh equal +particles or different particles are all + + align:start position:0% +particles or different particles are all + + + align:start position:0% +particles or different particles are all +very + + align:start position:0% +very + + + align:start position:0% +very +similar so if they are all very + + align:start position:0% +similar so if they are all very + + + align:start position:0% +similar so if they are all very +similar the particle doesn't care what + + align:start position:0% +similar the particle doesn't care what + + + align:start position:0% +similar the particle doesn't care what +the neighbor + + align:start position:0% +the neighbor + + + align:start position:0% +the neighbor +is okay in this + + align:start position:0% +is okay in this + + + align:start position:0% +is okay in this +limit again when you mix + + align:start position:0% +limit again when you mix + + + align:start position:0% +limit again when you mix +stuff the only effect you don't get any + + align:start position:0% +stuff the only effect you don't get any + + + align:start position:0% +stuff the only effect you don't get any +energy of mixing or enthalpy of mixing + + align:start position:0% +energy of mixing or enthalpy of mixing + + + align:start position:0% +energy of mixing or enthalpy of mixing +you don't get any change of volume of + + align:start position:0% +you don't get any change of volume of + + + align:start position:0% +you don't get any change of volume of +mixing because the particle doesn't want + + align:start position:0% +mixing because the particle doesn't want + + + align:start position:0% +mixing because the particle doesn't want +to change their preferred distances + + align:start position:0% +to change their preferred distances + + + align:start position:0% +to change their preferred distances +which would + + align:start position:0% +which would + + + align:start position:0% +which would +imply enthalpy of mixing or uh volume of + + align:start position:0% +imply enthalpy of mixing or uh volume of + + + align:start position:0% +imply enthalpy of mixing or uh volume of +mixing which would imply uh stay + + align:start position:0% +mixing which would imply uh stay + + + align:start position:0% +mixing which would imply uh stay +changing the + + align:start position:0% +changing the + + + align:start position:0% +changing the +distance because essentially they + + align:start position:0% +distance because essentially they + + + align:start position:0% +distance because essentially they +uh they like each other in the same + + align:start position:0% +uh they like each other in the same + + + align:start position:0% +uh they like each other in the same +way uh the + + align:start position:0% +way uh the + + + align:start position:0% +way uh the +only effect upon mixing is the + + align:start position:0% +only effect upon mixing is the + + + align:start position:0% +only effect upon mixing is the +randomness so the entropy + + align:start position:0% +randomness so the entropy + + + align:start position:0% +randomness so the entropy +mixing + + align:start position:0% +mixing + + + align:start position:0% +mixing +okay and therefore in this model that we + + align:start position:0% +okay and therefore in this model that we + + + align:start position:0% +okay and therefore in this model that we +Define uh we will assume that the + + align:start position:0% +Define uh we will assume that the + + + align:start position:0% +Define uh we will assume that the +entropy of mixing of the single particle + + align:start position:0% +entropy of mixing of the single particle + + + align:start position:0% +entropy of mixing of the single particle +is related to the + + align:start position:0% +is related to the + + + align:start position:0% +is related to the +surprise uh and that is the only effect + + align:start position:0% +surprise uh and that is the only effect + + + align:start position:0% +surprise uh and that is the only effect +of this ideal situation that we're going + + align:start position:0% +of this ideal situation that we're going + + + align:start position:0% +of this ideal situation that we're going +to + + align:start position:0% +to + + + align:start position:0% +to +Define + + align:start position:0% +Define + + + align:start position:0% +Define +okay so with that we set the ground for + + align:start position:0% +okay so with that we set the ground for + + + align:start position:0% +okay so with that we set the ground for +the next uh lecture \ No newline at end of file diff --git a/RmdAWsvcsZw.txt b/RmdAWsvcsZw.txt new file mode 100644 index 0000000000000000000000000000000000000000..17718d3a0444fb8e6979372065e8a605bc43393a --- /dev/null +++ b/RmdAWsvcsZw.txt @@ -0,0 +1,10163 @@ +align:start position:0% + +so what we're going to do today is + + align:start position:0% +so what we're going to do today is + + + align:start position:0% +so what we're going to do today is +continue our discussion of modular uh + + align:start position:0% +continue our discussion of modular uh + + + align:start position:0% +continue our discussion of modular uh +computer software and specifically focus + + align:start position:0% +computer software and specifically focus + + + align:start position:0% +computer software and specifically focus +on a topic we started talking about the + + align:start position:0% +on a topic we started talking about the + + + align:start position:0% +on a topic we started talking about the +last time called soft + + align:start position:0% + + + + align:start position:0% + +modularity and once we um figure out um + + align:start position:0% +modularity and once we um figure out um + + + align:start position:0% +modularity and once we um figure out um +you know finish our story with um um + + align:start position:0% +you know finish our story with um um + + + align:start position:0% +you know finish our story with um um +with regard to soft modularity and + + align:start position:0% +with regard to soft modularity and + + + align:start position:0% +with regard to soft modularity and +understand um exactly what this means + + align:start position:0% +understand um exactly what this means + + + align:start position:0% +understand um exactly what this means +we're we going to get to talk starting + + align:start position:0% +we're we going to get to talk starting + + + align:start position:0% +we're we going to get to talk starting +to talk about a different kind of + + align:start position:0% +to talk about a different kind of + + + align:start position:0% +to talk about a different kind of +modularity called uh enforced + + align:start position:0% + + + + align:start position:0% + +modularity and enforced modularity is + + align:start position:0% +modularity and enforced modularity is + + + align:start position:0% +modularity and enforced modularity is +going to actually take us through um + + align:start position:0% +going to actually take us through um + + + align:start position:0% +going to actually take us through um +three lectures today um and the next two + + align:start position:0% +three lectures today um and the next two + + + align:start position:0% +three lectures today um and the next two +lectures um next week and the topic for + + align:start position:0% +lectures um next week and the topic for + + + align:start position:0% +lectures um next week and the topic for +today in terms of enforced modularity is + + align:start position:0% +today in terms of enforced modularity is + + + align:start position:0% +today in terms of enforced modularity is +a particular way of obtaining modularity + + align:start position:0% +a particular way of obtaining modularity + + + align:start position:0% +a particular way of obtaining modularity +in computer systems called client + + align:start position:0% +in computer systems called client + + + align:start position:0% +in computer systems called client +service organization + + align:start position:0% + + + + align:start position:0% + +or some people call it client server + + align:start position:0% +or some people call it client server + + + align:start position:0% +or some people call it client server +Computing and um that's the plan for + + align:start position:0% +Computing and um that's the plan for + + + align:start position:0% +Computing and um that's the plan for +today so what we saw the last time was + + align:start position:0% +today so what we saw the last time was + + + align:start position:0% +today so what we saw the last time was +basically a lecture describing uh for + + align:start position:0% +basically a lecture describing uh for + + + align:start position:0% +basically a lecture describing uh for +the most part how linking worked and the + + align:start position:0% +the most part how linking worked and the + + + align:start position:0% +the most part how linking worked and the +idea in linking is that you + + align:start position:0% +idea in linking is that you + + + align:start position:0% +idea in linking is that you +have a number of software modules and + + align:start position:0% +have a number of software modules and + + + align:start position:0% +have a number of software modules and +your goal is to take all of them and to + + align:start position:0% +your goal is to take all of them and to + + + align:start position:0% +your goal is to take all of them and to +get an executable program out of them + + align:start position:0% +get an executable program out of them + + + align:start position:0% +get an executable program out of them +that you could then um that another + + align:start position:0% +that you could then um that another + + + align:start position:0% +that you could then um that another +program could load into memory and run + + align:start position:0% +program could load into memory and run + + + align:start position:0% +program could load into memory and run +and that was that task was being done + + align:start position:0% +and that was that task was being done + + + align:start position:0% +and that was that task was being done +by a piece of system software called a + + align:start position:0% +by a piece of system software called a + + + align:start position:0% +by a piece of system software called a +Linker and out pops an executable + + align:start position:0% +Linker and out pops an executable + + + align:start position:0% +Linker and out pops an executable +program um so at the end of lecture last + + align:start position:0% +program um so at the end of lecture last + + + align:start position:0% +program um so at the end of lecture last +time a couple of students asked me um + + align:start position:0% +time a couple of students asked me um + + + align:start position:0% +time a couple of students asked me um +two things one was why we were actually + + align:start position:0% +two things one was why we were actually + + + align:start position:0% +two things one was why we were actually +talking about this and the second more + + align:start position:0% +talking about this and the second more + + + align:start position:0% +talking about this and the second more +important question was why it wasn't in + + align:start position:0% +important question was why it wasn't in + + + align:start position:0% +important question was why it wasn't in +the notes and so let me answer the first + + align:start position:0% +the notes and so let me answer the first + + + align:start position:0% +the notes and so let me answer the first +question uh the question first um you + + align:start position:0% +question uh the question first um you + + + align:start position:0% +question uh the question first um you +know the plan in lectures is to do is to + + align:start position:0% +know the plan in lectures is to do is to + + + align:start position:0% +know the plan in lectures is to do is to +understand Concepts and computer systems + + align:start position:0% +understand Concepts and computer systems + + + align:start position:0% +understand Concepts and computer systems +with examples and often times we find + + align:start position:0% +with examples and often times we find + + + align:start position:0% +with examples and often times we find +examples that aren't actually in the + + align:start position:0% +examples that aren't actually in the + + + align:start position:0% +examples that aren't actually in the +notes and we use them a because if we + + align:start position:0% +notes and we use them a because if we + + + align:start position:0% +notes and we use them a because if we +don't use different examples there's + + align:start position:0% +don't use different examples there's + + + align:start position:0% +don't use different examples there's +sort of not as much incentive to show up + + align:start position:0% +sort of not as much incentive to show up + + + align:start position:0% +sort of not as much incentive to show up +um but often because some of the + + align:start position:0% +um but often because some of the + + + align:start position:0% +um but often because some of the +examples that work better in lecture + + align:start position:0% +examples that work better in lecture + + + align:start position:0% +examples that work better in lecture +don't actually work out um as clearly uh + + align:start position:0% +don't actually work out um as clearly uh + + + align:start position:0% +don't actually work out um as clearly uh +in the notes so we do tend to use uh + + align:start position:0% +in the notes so we do tend to use uh + + + align:start position:0% +in the notes so we do tend to use uh +different examples John to the first + + align:start position:0% +different examples John to the first + + + align:start position:0% +different examples John to the first +question why we actually looked at the + + align:start position:0% +question why we actually looked at the + + + align:start position:0% +question why we actually looked at the +Linker um first of all it's you know + + align:start position:0% +Linker um first of all it's you know + + + align:start position:0% +Linker um first of all it's you know +it's a common piece of software that + + align:start position:0% +it's a common piece of software that + + + align:start position:0% +it's a common piece of software that +pretty much every program that you run + + align:start position:0% +pretty much every program that you run + + + align:start position:0% +pretty much every program that you run +today + + align:start position:0% +today + + + align:start position:0% +today +goes through a process of linking but + + align:start position:0% +goes through a process of linking but + + + align:start position:0% +goes through a process of linking but +what it actually allowed us to do was + + align:start position:0% +what it actually allowed us to do was + + + align:start position:0% +what it actually allowed us to do was +illustrate two um main Concepts in + + align:start position:0% +illustrate two um main Concepts in + + + align:start position:0% +illustrate two um main Concepts in +naming having to do with the way in + + align:start position:0% +naming having to do with the way in + + + align:start position:0% +naming having to do with the way in +which um the name mathing algorithm + + align:start position:0% + + + + align:start position:0% + +worked and in the context of the Linker + + align:start position:0% +worked and in the context of the Linker + + + align:start position:0% +worked and in the context of the Linker +the problem was to take these symbols + + align:start position:0% +the problem was to take these symbols + + + align:start position:0% +the problem was to take these symbols +that you find in a program and um + + align:start position:0% +that you find in a program and um + + + align:start position:0% +that you find in a program and um +basically resolve them in other words + + align:start position:0% +basically resolve them in other words + + + align:start position:0% +basically resolve them in other words +find out where they're defined and where + + align:start position:0% +find out where they're defined and where + + + align:start position:0% +find out where they're defined and where +the instructions corresponding to those + + align:start position:0% +the instructions corresponding to those + + + align:start position:0% +the instructions corresponding to those +symbols or where the data corresponding + + align:start position:0% +symbols or where the data corresponding + + + align:start position:0% +symbols or where the data corresponding +to the the symbol was actually uh + + align:start position:0% +to the the symbol was actually uh + + + align:start position:0% +to the the symbol was actually uh +located and uh the concepts that we saw + + align:start position:0% +located and uh the concepts that we saw + + + align:start position:0% +located and uh the concepts that we saw +were uh two two different concepts uh + + align:start position:0% +were uh two two different concepts uh + + + align:start position:0% +were uh two two different concepts uh +the first was name mapping using a table + + align:start position:0% + + + + align:start position:0% + +lookup where within each object file + + align:start position:0% +lookup where within each object file + + + align:start position:0% +lookup where within each object file +there was a symbol table that mapped + + align:start position:0% +there was a symbol table that mapped + + + align:start position:0% +there was a symbol table that mapped +between the symbols and found in that + + align:start position:0% +between the symbols and found in that + + + align:start position:0% +between the symbols and found in that +module to the location um where the + + align:start position:0% +module to the location um where the + + + align:start position:0% +module to the location um where the +symbols were defined further and another + + align:start position:0% +symbols were defined further and another + + + align:start position:0% +symbols were defined further and another +example which was of doing name mapping + + align:start position:0% +example which was of doing name mapping + + + align:start position:0% +example which was of doing name mapping +which was a process of search through a + + align:start position:0% +which was a process of search through a + + + align:start position:0% +which was a process of search through a +series of + + align:start position:0% + + + + align:start position:0% + +contexts and in particular uh we looked + + align:start position:0% +contexts and in particular uh we looked + + + align:start position:0% +contexts and in particular uh we looked +at the problem of when you're in the + + align:start position:0% +at the problem of when you're in the + + + align:start position:0% +at the problem of when you're in the +context of um you know LD which GCC uses + + align:start position:0% +context of um you know LD which GCC uses + + + align:start position:0% +context of um you know LD which GCC uses +uh when it finds goes through a sequence + + align:start position:0% +uh when it finds goes through a sequence + + + align:start position:0% +uh when it finds goes through a sequence +of. o files as well as libraries in the + + align:start position:0% +of. o files as well as libraries in the + + + align:start position:0% +of. o files as well as libraries in the +command line what algorithm it actually + + align:start position:0% +command line what algorithm it actually + + + align:start position:0% +command line what algorithm it actually +uses to um resolve its symbols and I + + align:start position:0% +uses to um resolve its symbols and I + + + align:start position:0% +uses to um resolve its symbols and I +realized now that what I had left out on + + align:start position:0% +realized now that what I had left out on + + + align:start position:0% +realized now that what I had left out on +the board there was there was a couple + + align:start position:0% +the board there was there was a couple + + + align:start position:0% +the board there was there was a couple +of mistakes in the algorithm and I asked + + align:start position:0% +of mistakes in the algorithm and I asked + + + align:start position:0% +of mistakes in the algorithm and I asked +what the mistakes were and I realized I + + align:start position:0% +what the mistakes were and I realized I + + + align:start position:0% +what the mistakes were and I realized I +didn't actually fix and show you what + + align:start position:0% +didn't actually fix and show you what + + + align:start position:0% +didn't actually fix and show you what +the actual what the actual algorithm is + + align:start position:0% +the actual what the actual algorithm is + + + align:start position:0% +the actual what the actual algorithm is +correctly so I thought I'd spend a + + align:start position:0% +correctly so I thought I'd spend a + + + align:start position:0% +correctly so I thought I'd spend a +minute doing that so that you can you + + align:start position:0% +minute doing that so that you can you + + + align:start position:0% +minute doing that so that you can you +know if you have something wrong in your + + align:start position:0% +know if you have something wrong in your + + + align:start position:0% +know if you have something wrong in your +notes you can um fix that up because I + + align:start position:0% +notes you can um fix that up because I + + + align:start position:0% +notes you can um fix that up because I +realize I actually never said what the + + align:start position:0% +realize I actually never said what the + + + align:start position:0% +realize I actually never said what the +right thing was so if you recall the + + align:start position:0% +right thing was so if you recall the + + + align:start position:0% +right thing was so if you recall the +general problem was you have um GCC + + align:start position:0% +general problem was you have um GCC + + + align:start position:0% +general problem was you have um GCC +running on a set of. o files f1.0 all + + align:start position:0% +running on a set of. o files f1.0 all + + + align:start position:0% +running on a set of. o files f1.0 all +the way through fn. o and what we're + + align:start position:0% +the way through fn. o and what we're + + + align:start position:0% +the way through fn. o and what we're +trying to do is describe an algorithm + + align:start position:0% +trying to do is describe an algorithm + + + align:start position:0% +trying to do is describe an algorithm +where when you obtain the I object file + + align:start position:0% +where when you obtain the I object file + + + align:start position:0% +where when you obtain the I object file +and you you have a set of currently + + align:start position:0% +and you you have a set of currently + + + align:start position:0% +and you you have a set of currently +defined symbols and a set of currently + + align:start position:0% +defined symbols and a set of currently + + + align:start position:0% +defined symbols and a set of currently +undefined symbols how you can you know + + align:start position:0% +undefined symbols how you can you know + + + align:start position:0% +undefined symbols how you can you know +maintain three sets the set of object + + align:start position:0% +maintain three sets the set of object + + + align:start position:0% +maintain three sets the set of object +files that go into the executable the + + align:start position:0% +files that go into the executable the + + + align:start position:0% +files that go into the executable the +set of defined symbols that have been + + align:start position:0% +set of defined symbols that have been + + + align:start position:0% +set of defined symbols that have been +seen so far and the set of undefined + + align:start position:0% +seen so far and the set of undefined + + + align:start position:0% +seen so far and the set of undefined +symbols that have been seen so far and + + align:start position:0% +symbols that have been seen so far and + + + align:start position:0% +symbols that have been seen so far and +you want to keep updating + + align:start position:0% +you want to keep updating + + + align:start position:0% +you want to keep updating +that so one way to easily see what's + + align:start position:0% +that so one way to easily see what's + + + align:start position:0% +that so one way to easily see what's +going on is with a + + align:start position:0% +going on is with a + + + align:start position:0% +going on is with a +picture so up until now until you + + align:start position:0% +picture so up until now until you + + + align:start position:0% +picture so up until now until you +finished uh IUS one files let's say + + align:start position:0% +finished uh IUS one files let's say + + + align:start position:0% +finished uh IUS one files let's say +you've built up a set + + align:start position:0% +you've built up a set + + + align:start position:0% +you've built up a set +um U of all of the undefined symbols + + align:start position:0% +um U of all of the undefined symbols + + + align:start position:0% +um U of all of the undefined symbols +that have been encountered so + + align:start position:0% +that have been encountered so + + + align:start position:0% +that have been encountered so +far and likewise you have another set D + + align:start position:0% +far and likewise you have another set D + + + align:start position:0% +far and likewise you have another set D +of all of the symbols that have been + + align:start position:0% +of all of the symbols that have been + + + align:start position:0% +of all of the symbols that have been +defined so far that you've encountered + + align:start position:0% +defined so far that you've encountered + + + align:start position:0% +defined so far that you've encountered +and have been defined so far so D and U + + align:start position:0% +and have been defined so far so D and U + + + align:start position:0% +and have been defined so far so D and U +dynamically change as you go from left + + align:start position:0% +dynamically change as you go from left + + + align:start position:0% +dynamically change as you go from left +to right through the sequence of files + + align:start position:0% +to right through the sequence of files + + + align:start position:0% +to right through the sequence of files +now when you're on the I file there's a + + align:start position:0% +now when you're on the I file there's a + + + align:start position:0% +now when you're on the I file there's a +set of symbols that have been defined + + align:start position:0% +set of symbols that have been defined + + + align:start position:0% +set of symbols that have been defined +that are going to be defined in the I + + align:start position:0% +that are going to be defined in the I + + + align:start position:0% +that are going to be defined in the I +file and that set does not intersect + + align:start position:0% +file and that set does not intersect + + + align:start position:0% +file and that set does not intersect +with the set D because if it did then + + align:start position:0% +with the set D because if it did then + + + align:start position:0% +with the set D because if it did then +you have an overlapping defined symbol + + align:start position:0% +you have an overlapping defined symbol + + + align:start position:0% +you have an overlapping defined symbol +and that's an error so the interesting + + align:start position:0% +and that's an error so the interesting + + + align:start position:0% +and that's an error so the interesting +case is to look at this kind of an + + align:start position:0% +case is to look at this kind of an + + + align:start position:0% +case is to look at this kind of an +example where you have a set di of the + + align:start position:0% +example where you have a set di of the + + + align:start position:0% +example where you have a set di of the +symbols that were defined in the I + + align:start position:0% +symbols that were defined in the I + + + align:start position:0% +symbols that were defined in the I +file and likewise in the I file there + + align:start position:0% +file and likewise in the I file there + + + align:start position:0% +file and likewise in the I file there +are going to be a set of undefined + + align:start position:0% +are going to be a set of undefined + + + align:start position:0% +are going to be a set of undefined +symbols and clearly that set doesn't + + align:start position:0% +symbols and clearly that set doesn't + + + align:start position:0% +symbols and clearly that set doesn't +overlap with the set di because if it's + + align:start position:0% +overlap with the set di because if it's + + + align:start position:0% +overlap with the set di because if it's +undefined it can't be defined in the + + align:start position:0% +undefined it can't be defined in the + + + align:start position:0% +undefined it can't be defined in the +same file so that set in general looks + + align:start position:0% +same file so that set in general looks + + + align:start position:0% +same file so that set in general looks +something like + + align:start position:0% + + + + align:start position:0% + +this it has some symbols undefined in + + align:start position:0% +this it has some symbols undefined in + + + align:start position:0% +this it has some symbols undefined in +this object file that are also undefined + + align:start position:0% +this object file that are also undefined + + + align:start position:0% +this object file that are also undefined +previously + + align:start position:0% +previously + + + align:start position:0% +previously +some symbols that are undefined in this + + align:start position:0% +some symbols that are undefined in this + + + align:start position:0% +some symbols that are undefined in this +file that have been defined + + align:start position:0% +file that have been defined + + + align:start position:0% +file that have been defined +previously and some symbols that have + + align:start position:0% +previously and some symbols that have + + + align:start position:0% +previously and some symbols that have +been undefined here that you've really + + align:start position:0% +been undefined here that you've really + + + align:start position:0% +been undefined here that you've really +never seen + + align:start position:0% + + + + align:start position:0% + +before so you got to update two things + + align:start position:0% +before so you got to update two things + + + align:start position:0% +before so you got to update two things +so D gets updated pretty easily D just + + align:start position:0% +so D gets updated pretty easily D just + + + align:start position:0% +so D gets updated pretty easily D just +becomes D Union dii and if D + + align:start position:0% +becomes D Union dii and if D + + + align:start position:0% +becomes D Union dii and if D +intersection di is not null then you + + align:start position:0% +intersection di is not null then you + + + align:start position:0% +intersection di is not null then you +know there's an + + align:start position:0% +know there's an + + + align:start position:0% +know there's an +error and now you need to update U and + + align:start position:0% +error and now you need to update U and + + + align:start position:0% +error and now you need to update U and +there are many ways to do it that are + + align:start position:0% +there are many ways to do it that are + + + align:start position:0% +there are many ways to do it that are +more efficient than what we're going to + + align:start position:0% +more efficient than what we're going to + + + align:start position:0% +more efficient than what we're going to +write out but um it's pretty easy to see + + align:start position:0% +write out but um it's pretty easy to see + + + align:start position:0% +write out but um it's pretty easy to see +that you needs to get updated by + + align:start position:0% +that you needs to get updated by + + + align:start position:0% +that you needs to get updated by +unioning the current set with + + align:start position:0% +unioning the current set with + + + align:start position:0% +unioning the current set with +UI and so that kind of gives you this + + align:start position:0% +UI and so that kind of gives you this + + + align:start position:0% +UI and so that kind of gives you this +together with that but now you have to + + align:start position:0% +together with that but now you have to + + + align:start position:0% +together with that but now you have to +subtract out everything that's been + + align:start position:0% +subtract out everything that's been + + + align:start position:0% +subtract out everything that's been +defined already and since we updated D + + align:start position:0% +defined already and since we updated D + + + align:start position:0% +defined already and since we updated D +first we could do that very easily by + + align:start position:0% +first we could do that very easily by + + + align:start position:0% +first we could do that very easily by +just subtracting out the set of all + + align:start position:0% +just subtracting out the set of all + + + align:start position:0% +just subtracting out the set of all +defined + + align:start position:0% +defined + + + align:start position:0% +defined +symbols and you run this through until + + align:start position:0% +symbols and you run this through until + + + align:start position:0% +symbols and you run this through until +the end and if you find that in the end + + align:start position:0% +the end and if you find that in the end + + + align:start position:0% +the end and if you find that in the end +U is not null then you know that um + + align:start position:0% +U is not null then you know that um + + + align:start position:0% +U is not null then you know that um +there's an undefined symbol so the + + align:start position:0% +there's an undefined symbol so the + + + align:start position:0% +there's an undefined symbol so the +linking doesn't actually work you can't + + align:start position:0% +linking doesn't actually work you can't + + + align:start position:0% +linking doesn't actually work you can't +produce an executable out of it with + + align:start position:0% +produce an executable out of it with + + + align:start position:0% +produce an executable out of it with +stat linking + + align:start position:0% +stat linking + + + align:start position:0% +stat linking +okay + + align:start position:0% +okay + + + align:start position:0% +okay +okay so when you do combine programs in + + align:start position:0% +okay so when you do combine programs in + + + align:start position:0% +okay so when you do combine programs in +this fashion to produce an + + align:start position:0% +this fashion to produce an + + + align:start position:0% +this fashion to produce an +executable there are all these different + + align:start position:0% +executable there are all these different + + + align:start position:0% +executable there are all these different +modules that have been brought together + + align:start position:0% +modules that have been brought together + + + align:start position:0% +modules that have been brought together +to run on um in an interpreter and you + + align:start position:0% +to run on um in an interpreter and you + + + align:start position:0% +to run on um in an interpreter and you +have to ask what kind of properties that + + align:start position:0% +have to ask what kind of properties that + + + align:start position:0% +have to ask what kind of properties that +program ends up having what kind of + + align:start position:0% +program ends up having what kind of + + + align:start position:0% +program ends up having what kind of +modularity do you get by combining these + + align:start position:0% +modularity do you get by combining these + + + align:start position:0% +modularity do you get by combining these +modules together in fashion it'll turn + + align:start position:0% +modules together in fashion it'll turn + + + align:start position:0% +modules together in fashion it'll turn +out that modularity is uh it's a form of + + align:start position:0% +out that modularity is uh it's a form of + + + align:start position:0% +out that modularity is uh it's a form of +modularity called + + align:start position:0% +modularity called + + + align:start position:0% +modularity called +soft modularity and to understand why + + align:start position:0% +soft modularity and to understand why + + + align:start position:0% +soft modularity and to understand why +you have to understand what the + + align:start position:0% +you have to understand what the + + + align:start position:0% +you have to understand what the +interfaces between the different modules + + align:start position:0% +interfaces between the different modules + + + align:start position:0% +interfaces between the different modules +look + + align:start position:0% +look + + + align:start position:0% +look +like but basically when you look at a c + + align:start position:0% +like but basically when you look at a c + + + align:start position:0% +like but basically when you look at a c +program and we saw an example last time + + align:start position:0% +program and we saw an example last time + + + align:start position:0% +program and we saw an example last time +of how these modules work together um + + align:start position:0% +of how these modules work together um + + + align:start position:0% +of how these modules work together um +the different modules interact with one + + align:start position:0% +the different modules interact with one + + + align:start position:0% +the different modules interact with one +another through procedures and + + align:start position:0% +another through procedures and + + + align:start position:0% +another through procedures and +procedures between modules have + + align:start position:0% +procedures between modules have + + + align:start position:0% +procedures between modules have +something that I'll call a procedure + + align:start position:0% + + + + align:start position:0% + +contract and really to understand the + + align:start position:0% +contract and really to understand the + + + align:start position:0% +contract and really to understand the +property of the modularity that you get + + align:start position:0% +property of the modularity that you get + + + align:start position:0% +property of the modularity that you get +from procedural contract we need to + + align:start position:0% +from procedural contract we need to + + + align:start position:0% +from procedural contract we need to +understand a little bit about what + + align:start position:0% +understand a little bit about what + + + align:start position:0% +understand a little bit about what +happens underneath the covers when um + + align:start position:0% +happens underneath the covers when um + + + align:start position:0% +happens underneath the covers when um +you know a caller of a procedure invokes + + align:start position:0% +you know a caller of a procedure invokes + + + align:start position:0% +you know a caller of a procedure invokes +a call E of a procedure and this is + + align:start position:0% +a call E of a procedure and this is + + + align:start position:0% +a call E of a procedure and this is +actually material + + align:start position:0% +actually material + + + align:start position:0% +actually material +from4 so if you um you know if you + + align:start position:0% +from4 so if you um you know if you + + + align:start position:0% +from4 so if you um you know if you +forgotten I'll refresh your memory a + + align:start position:0% +forgotten I'll refresh your memory a + + + align:start position:0% +forgotten I'll refresh your memory a +little bit about it + + align:start position:0% +little bit about it + + + align:start position:0% +little bit about it +um so very abstractly if you look at uh + + align:start position:0% +um so very abstractly if you look at uh + + + align:start position:0% +um so very abstractly if you look at uh +a computer you know it's got a processor + + align:start position:0% +a computer you know it's got a processor + + + align:start position:0% +a computer you know it's got a processor +in it that's + + align:start position:0% +in it that's + + + align:start position:0% +in it that's +running um that actually executes + + align:start position:0% +running um that actually executes + + + align:start position:0% +running um that actually executes +instructions and it has a chunk of + + align:start position:0% +instructions and it has a chunk of + + + align:start position:0% +instructions and it has a chunk of +memory and in that memory there's a + + align:start position:0% +memory and in that memory there's a + + + align:start position:0% +memory and in that memory there's a +portion of memory that um corresponds to + + align:start position:0% +portion of memory that um corresponds to + + + align:start position:0% +portion of memory that um corresponds to +the stack which is really where + + align:start position:0% +the stack which is really where + + + align:start position:0% +the stack which is really where +procedures um the interesting stuff with + + align:start position:0% +procedures um the interesting stuff with + + + align:start position:0% +procedures um the interesting stuff with +procedures gets uh implemented and we + + align:start position:0% +procedures gets uh implemented and we + + + align:start position:0% +procedures gets uh implemented and we +also have a bunch of registers so you + + align:start position:0% +also have a bunch of registers so you + + + align:start position:0% +also have a bunch of registers so you +know inside the processor and um you + + align:start position:0% +know inside the processor and um you + + + align:start position:0% +know inside the processor and um you +have a special variable here called the + + align:start position:0% +have a special variable here called the + + + align:start position:0% +have a special variable here called the +stack pointer which keeps track of um + + align:start position:0% +stack pointer which keeps track of um + + + align:start position:0% +stack pointer which keeps track of um +where the current head of the stack is + + align:start position:0% +where the current head of the stack is + + + align:start position:0% +where the current head of the stack is +that you can then start pulling um + + align:start position:0% +that you can then start pulling um + + + align:start position:0% +that you can then start pulling um +elements + + align:start position:0% +elements + + + align:start position:0% +elements +off the journey plan is is a caller the + + align:start position:0% +off the journey plan is is a caller the + + + align:start position:0% +off the journey plan is is a caller the +caller and the colleag interact with one + + align:start position:0% +caller and the colleag interact with one + + + align:start position:0% +caller and the colleag interact with one +another by means + + align:start position:0% +another by means + + + align:start position:0% +another by means +of so when a caller wants to invoke um + + align:start position:0% +of so when a caller wants to invoke um + + + align:start position:0% +of so when a caller wants to invoke um +the + + align:start position:0% +the + + + align:start position:0% +the +colle what it does is it takes the + + align:start position:0% +colle what it does is it takes the + + + align:start position:0% +colle what it does is it takes the +arguments to the procedure and pushes + + align:start position:0% +arguments to the procedure and pushes + + + align:start position:0% +arguments to the procedure and pushes +them onto the stack one after another + + align:start position:0% +them onto the stack one after another + + + align:start position:0% +them onto the stack one after another +then the last thing it does is to tell + + align:start position:0% +then the last thing it does is to tell + + + align:start position:0% +then the last thing it does is to tell +the coli where it should return control + + align:start position:0% +the coli where it should return control + + + align:start position:0% +the coli where it should return control +after the procedure function has + + align:start position:0% +after the procedure function has + + + align:start position:0% +after the procedure function has +actually been executed and that's the + + align:start position:0% +actually been executed and that's the + + + align:start position:0% +actually been executed and that's the +the last thing that's pushed on top of + + align:start position:0% +the last thing that's pushed on top of + + + align:start position:0% +the last thing that's pushed on top of +the stack is the is the + + align:start position:0% +the stack is the is the + + + align:start position:0% +the stack is the is the +uh so then after it does that the caller + + align:start position:0% +uh so then after it does that the caller + + + align:start position:0% +uh so then after it does that the caller +then jumps to a location where the + + align:start position:0% +then jumps to a location where the + + + align:start position:0% +then jumps to a location where the +coli's module is located and then + + align:start position:0% +coli's module is located and then + + + align:start position:0% +coli's module is located and then +control passes to the + + align:start position:0% +control passes to the + + + align:start position:0% +control passes to the +coli what the collie then does is it + + align:start position:0% +coli what the collie then does is it + + + align:start position:0% +coli what the collie then does is it +pops you know it finds out what the + + align:start position:0% +pops you know it finds out what the + + + align:start position:0% +pops you know it finds out what the +return address is pops the arguments one + + align:start position:0% +return address is pops the arguments one + + + align:start position:0% +return address is pops the arguments one +after another and then goes ahead and + + align:start position:0% +after another and then goes ahead and + + + align:start position:0% +after another and then goes ahead and +runs the function and then at the end of + + align:start position:0% +runs the function and then at the end of + + + align:start position:0% +runs the function and then at the end of +that it looks at the return address and + + align:start position:0% +that it looks at the return address and + + + align:start position:0% +that it looks at the return address and +pass control back and before it does + + align:start position:0% +pass control back and before it does + + + align:start position:0% +pass control back and before it does +that it actually puts the answer and by + + align:start position:0% +that it actually puts the answer and by + + + align:start position:0% +that it actually puts the answer and by +convention and you know let's assume + + align:start position:0% +convention and you know let's assume + + + align:start position:0% +convention and you know let's assume +that it puts the answer in some in a + + align:start position:0% +that it puts the answer in some in a + + + align:start position:0% +that it puts the answer in some in a +special register and that's part of the + + align:start position:0% +special register and that's part of the + + + align:start position:0% +special register and that's part of the +contract as + + align:start position:0% + + + + align:start position:0% + +well and um once the caller gets control + + align:start position:0% +well and um once the caller gets control + + + align:start position:0% +well and um once the caller gets control +back from the Ki it can proceed as + + align:start position:0% +back from the Ki it can proceed as + + + align:start position:0% +back from the Ki it can proceed as +before now the important thing about + + align:start position:0% +before now the important thing about + + + align:start position:0% +before now the important thing about +this way of interacting between caller + + align:start position:0% +this way of interacting between caller + + + align:start position:0% +this way of interacting between caller +and Ki with procedures stack is that + + align:start position:0% +and Ki with procedures stack is that + + + align:start position:0% +and Ki with procedures stack is that +this contract has to obey an invariant + + align:start position:0% +this contract has to obey an invariant + + + align:start position:0% +this contract has to obey an invariant +or a dis discipline called the stack + + align:start position:0% +or a dis discipline called the stack + + + align:start position:0% +or a dis discipline called the stack +discipline + + align:start position:0% + + + + align:start position:0% + +and the essence of the stack discipline + + align:start position:0% +and the essence of the stack discipline + + + align:start position:0% +and the essence of the stack discipline +is that the colleag should leave the + + align:start position:0% +is that the colleag should leave the + + + align:start position:0% +is that the colleag should leave the +stack exactly the way the caller left it + + align:start position:0% +stack exactly the way the caller left it + + + align:start position:0% +stack exactly the way the caller left it +when it invoked the + + align:start position:0% + + + + align:start position:0% + +colleag so which means that the caller + + align:start position:0% +colleag so which means that the caller + + + align:start position:0% +colleag so which means that the caller +had set up a bunch of arguments on it + + align:start position:0% +had set up a bunch of arguments on it + + + align:start position:0% +had set up a bunch of arguments on it +and put the return um address on it um + + align:start position:0% +and put the return um address on it um + + + align:start position:0% +and put the return um address on it um +the colle should really leave things as + + align:start position:0% +the colle should really leave things as + + + align:start position:0% +the colle should really leave things as +is and in fact the col is not allowed to + + align:start position:0% +is and in fact the col is not allowed to + + + align:start position:0% +is and in fact the col is not allowed to +touch anything it should leave + + align:start position:0% +touch anything it should leave + + + align:start position:0% +touch anything it should leave +everything as is pretty much except for + + align:start position:0% +everything as is pretty much except for + + + align:start position:0% +everything as is pretty much except for +the register that has the answer and as + + align:start position:0% +the register that has the answer and as + + + align:start position:0% +the register that has the answer and as +long as this discipline is maintained + + align:start position:0% +long as this discipline is maintained + + + align:start position:0% +long as this discipline is maintained +and that invariant is maintained across + + align:start position:0% +and that invariant is maintained across + + + align:start position:0% +and that invariant is maintained across +procedure invocations this model of + + align:start position:0% +procedure invocations this model of + + + align:start position:0% +procedure invocations this model of +using Stacks is extremely powerful you + + align:start position:0% +using Stacks is extremely powerful you + + + align:start position:0% +using Stacks is extremely powerful you +could Implement all sorts of procedures + + align:start position:0% +could Implement all sorts of procedures + + + align:start position:0% +could Implement all sorts of procedures +nested procedure I mean recursive + + align:start position:0% +nested procedure I mean recursive + + + align:start position:0% +nested procedure I mean recursive +procedures mutually recursive procedures + + align:start position:0% +procedures mutually recursive procedures + + + align:start position:0% +procedures mutually recursive procedures +and so on because um you know each of + + align:start position:0% +and so on because um you know each of + + + align:start position:0% +and so on because um you know each of +these invocations of a procedure has a + + align:start position:0% +these invocations of a procedure has a + + + align:start position:0% +these invocations of a procedure has a +certain portion of the stack um that + + align:start position:0% +certain portion of the stack um that + + + align:start position:0% +certain portion of the stack um that +corresponds to an activation frame and + + align:start position:0% +corresponds to an activation frame and + + + align:start position:0% +corresponds to an activation frame and +as long as this discipline is maintained + + align:start position:0% +as long as this discipline is maintained + + + align:start position:0% +as long as this discipline is maintained +you can be quite complicated you can do + + align:start position:0% +you can be quite complicated you can do + + + align:start position:0% +you can be quite complicated you can do +quite complicated and interesting + + align:start position:0% +quite complicated and interesting + + + align:start position:0% +quite complicated and interesting +combinations of + + align:start position:0% +combinations of + + + align:start position:0% +combinations of +modules but the problem is that + + align:start position:0% +modules but the problem is that + + + align:start position:0% +modules but the problem is that +that mod it depends crucially on the + + align:start position:0% +that mod it depends crucially on the + + + align:start position:0% +that mod it depends crucially on the +stack discipline being maintained and + + align:start position:0% +stack discipline being maintained and + + + align:start position:0% +stack discipline being maintained and +any violation of it CIF can disrupt the + + align:start position:0% +any violation of it CIF can disrupt the + + + align:start position:0% +any violation of it CIF can disrupt the +collar and bring it + + align:start position:0% +collar and bring it + + + align:start position:0% +collar and bring it +down there are many ways in which this + + align:start position:0% +down there are many ways in which this + + + align:start position:0% +down there are many ways in which this +this discipline could be violated and + + align:start position:0% +this discipline could be violated and + + + align:start position:0% +this discipline could be violated and +the easiest one uh is that there's some + + align:start position:0% +the easiest one uh is that there's some + + + align:start position:0% +the easiest one uh is that there's some +error or bug in the collie and the + + align:start position:0% +error or bug in the collie and the + + + align:start position:0% +error or bug in the collie and the +collie corrupts the + + align:start position:0% + + + + align:start position:0% + +stack or the collie corrupts the stack + + align:start position:0% +stack or the collie corrupts the stack + + + align:start position:0% +stack or the collie corrupts the stack +pointer so it actually returns control + + align:start position:0% +pointer so it actually returns control + + + align:start position:0% +pointer so it actually returns control +but the stack pointer points somewhere + + align:start position:0% +but the stack pointer points somewhere + + + align:start position:0% +but the stack pointer points somewhere +else else and um you know some bad + + align:start position:0% +else else and um you know some bad + + + align:start position:0% +else else and um you know some bad +instruction runs or you know you have + + align:start position:0% +instruction runs or you know you have + + + align:start position:0% +instruction runs or you know you have +you have a + + align:start position:0% +you have a + + + align:start position:0% +you have a +problem now another problem is that the + + align:start position:0% +problem now another problem is that the + + + align:start position:0% +problem now another problem is that the +collie + + align:start position:0% + + + + align:start position:0% + +crashes for instance there's a divide by + + align:start position:0% +crashes for instance there's a divide by + + + align:start position:0% +crashes for instance there's a divide by +zero or there's some other violation + + align:start position:0% +zero or there's some other violation + + + align:start position:0% +zero or there's some other violation +that causes the col to crash and then + + align:start position:0% +that causes the col to crash and then + + + align:start position:0% +that causes the col to crash and then +the CER comes coming down you know comes + + align:start position:0% +the CER comes coming down you know comes + + + align:start position:0% +the CER comes coming down you know comes +crashing down as well + + align:start position:0% + + + + align:start position:0% + +and there's a bunch of other reasons but + + align:start position:0% +and there's a bunch of other reasons but + + + align:start position:0% +and there's a bunch of other reasons but +all of them have to do with the stack + + align:start position:0% +all of them have to do with the stack + + + align:start position:0% +all of them have to do with the stack +discipline being violated or with the + + align:start position:0% +discipline being violated or with the + + + align:start position:0% +discipline being violated or with the +collie crashing and control never + + align:start position:0% +collie crashing and control never + + + align:start position:0% +collie crashing and control never +returning to the Coller um which means + + align:start position:0% +returning to the Coller um which means + + + align:start position:0% +returning to the Coller um which means +that the caller and the collie share + + align:start position:0% +that the caller and the collie share + + + align:start position:0% +that the caller and the collie share +fate you know if something bad happens + + align:start position:0% +fate you know if something bad happens + + + align:start position:0% +fate you know if something bad happens +to the person who's called sorry to + + align:start position:0% +to the person who's called sorry to + + + align:start position:0% +to the person who's called sorry to +which is called the collie then the + + align:start position:0% +which is called the collie then the + + + align:start position:0% +which is called the collie then the +caller struggles as well and doesn't + + align:start position:0% +caller struggles as well and doesn't + + + align:start position:0% +caller struggles as well and doesn't +really isn't able to + + align:start position:0% + + + + align:start position:0% + +continue so Cally this is referred to at + + align:start position:0% +continue so Cally this is referred to at + + + align:start position:0% +continue so Cally this is referred to at +as fate + + align:start position:0% + + + + align:start position:0% + +sharing and the resulting modularity is + + align:start position:0% +sharing and the resulting modularity is + + + align:start position:0% +sharing and the resulting modularity is +soft because any fault or error in the + + align:start position:0% +soft because any fault or error in the + + + align:start position:0% +soft because any fault or error in the +affects the collar the collar isn't um + + align:start position:0% +affects the collar the collar isn't um + + + align:start position:0% +affects the collar the collar isn't um +there isn't any kind of a firewall where + + align:start position:0% +there isn't any kind of a firewall where + + + align:start position:0% +there isn't any kind of a firewall where +errors in the coli are you know are + + align:start position:0% +errors in the coli are you know are + + + align:start position:0% +errors in the coli are you know are +insulated from errors in the collar + + align:start position:0% +insulated from errors in the collar + + + align:start position:0% +insulated from errors in the collar +there's sort of no shielding between the + + align:start position:0% +there's sort of no shielding between the + + + align:start position:0% +there's sort of no shielding between the +collar and Ki and why am I why is this + + align:start position:0% +collar and Ki and why am I why is this + + + align:start position:0% +collar and Ki and why am I why is this +thing going like all right um so there's + + align:start position:0% +thing going like all right um so there's + + + align:start position:0% +thing going like all right um so there's +no insulation between caller and Ki and + + align:start position:0% +no insulation between caller and Ki and + + + align:start position:0% +no insulation between caller and Ki and +um the resulting modularity is not as um + + align:start position:0% +um the resulting modularity is not as um + + + align:start position:0% +um the resulting modularity is not as um +hard as we would like it to + + align:start position:0% + + + + align:start position:0% + +be so this is the problem uh we'd like + + align:start position:0% +be so this is the problem uh we'd like + + + align:start position:0% +be so this is the problem uh we'd like +to solve today and the first solution + + align:start position:0% +to solve today and the first solution + + + align:start position:0% +to solve today and the first solution +we're going to um discuss + + align:start position:0% + + + + align:start position:0% + +is a way of organizing callers and Coles + + align:start position:0% +is a way of organizing callers and Coles + + + align:start position:0% +is a way of organizing callers and Coles +into an organization called client + + align:start position:0% +into an organization called client + + + align:start position:0% +into an organization called client +service organization + + align:start position:0% + + + + align:start position:0% + +and the main idea is going to actually + + align:start position:0% +and the main idea is going to actually + + + align:start position:0% +and the main idea is going to actually +involve a different abstraction for by + + align:start position:0% +involve a different abstraction for by + + + align:start position:0% +involve a different abstraction for by +which callers and colleages communicate + + align:start position:0% +which callers and colleages communicate + + + align:start position:0% +which callers and colleages communicate +with one another from the abstractions + + align:start position:0% +with one another from the abstractions + + + align:start position:0% +with one another from the abstractions +we've seen already we've already seen + + align:start position:0% +we've seen already we've already seen + + + align:start position:0% +we've seen already we've already seen +the memory abstraction where um you + + align:start position:0% +the memory abstraction where um you + + + align:start position:0% +the memory abstraction where um you +could read write values to a name and + + align:start position:0% +could read write values to a name and + + + align:start position:0% +could read write values to a name and +another person could read from it and + + align:start position:0% +another person could read from it and + + + align:start position:0% +another person could read from it and +we've already seen the interpreted + + align:start position:0% +we've already seen the interpreted + + + align:start position:0% +we've already seen the interpreted +abstraction it'll turn out we're going + + align:start position:0% +abstraction it'll turn out we're going + + + align:start position:0% +abstraction it'll turn out we're going +to use a slightly a different + + align:start position:0% +to use a slightly a different + + + align:start position:0% +to use a slightly a different +abstraction communication path + + align:start position:0% +abstraction communication path + + + align:start position:0% +abstraction communication path +abstraction to implement um The Client + + align:start position:0% +abstraction to implement um The Client + + + align:start position:0% +abstraction to implement um The Client +Service + + align:start position:0% +Service + + + align:start position:0% +Service +organization and the idea is the + + align:start position:0% +organization and the idea is the + + + align:start position:0% +organization and the idea is the +following your program is going to be + + align:start position:0% +following your program is going to be + + + align:start position:0% +following your program is going to be +decomposed um into clients and services + + align:start position:0% +decomposed um into clients and services + + + align:start position:0% +decomposed um into clients and services +and you might have many clients and many + + align:start position:0% +and you might have many clients and many + + + align:start position:0% +and you might have many clients and many +services and you know you could have + + align:start position:0% +services and you know you could have + + + align:start position:0% +services and you know you could have +client which is a client of one service + + align:start position:0% +client which is a client of one service + + + align:start position:0% +client which is a client of one service +and a service turn is a client of yet + + align:start position:0% +and a service turn is a client of yet + + + align:start position:0% +and a service turn is a client of yet +another service Cascade things um like + + align:start position:0% +another service Cascade things um like + + + align:start position:0% +another service Cascade things um like +that but any pairwise interaction is + + align:start position:0% +that but any pairwise interaction is + + + align:start position:0% +that but any pairwise interaction is +going to be between a client and a + + align:start position:0% +going to be between a client and a + + + align:start position:0% +going to be between a client and a +service and think of you know mapping + + align:start position:0% +service and think of you know mapping + + + align:start position:0% +service and think of you know mapping +that example onto here think of the uh + + align:start position:0% +that example onto here think of the uh + + + align:start position:0% +that example onto here think of the uh +Coli for example being the service and + + align:start position:0% +Coli for example being the service and + + + align:start position:0% +Coli for example being the service and +the caller being the client so the + + align:start position:0% +the caller being the client so the + + + align:start position:0% +the caller being the client so the +caller wants some work done so it's the + + align:start position:0% +caller wants some work done so it's the + + + align:start position:0% +caller wants some work done so it's the +client and it invokes the service the + + align:start position:0% +client and it invokes the service the + + + align:start position:0% +client and it invokes the service the +colleague to get that work + + align:start position:0% +colleague to get that work + + + align:start position:0% +colleague to get that work +done and the plan is going to be that + + align:start position:0% +done and the plan is going to be that + + + align:start position:0% +done and the plan is going to be that +the client and the service are going to + + align:start position:0% +the client and the service are going to + + + align:start position:0% +the client and the service are going to +run on different computers physically + + align:start position:0% +run on different computers physically + + + align:start position:0% +run on different computers physically +different computers and we're going to + + align:start position:0% +different computers and we're going to + + + align:start position:0% +different computers and we're going to +connect the computers up with a + + align:start position:0% +connect the computers up with a + + + align:start position:0% +connect the computers up with a +wire and the idea is the moment you do + + align:start position:0% +wire and the idea is the moment you do + + + align:start position:0% +wire and the idea is the moment you do +that um the crash of a call E doesn't + + align:start position:0% +that um the crash of a call E doesn't + + + align:start position:0% +that um the crash of a call E doesn't +actually bring the caller coming down + + align:start position:0% +actually bring the caller coming down + + + align:start position:0% +actually bring the caller coming down +because it's running on a completely + + align:start position:0% +because it's running on a completely + + + align:start position:0% +because it's running on a completely +different processor the stack is not + + align:start position:0% +different processor the stack is not + + + align:start position:0% +different processor the stack is not +shared the memory is not shared um you + + align:start position:0% +shared the memory is not shared um you + + + align:start position:0% +shared the memory is not shared um you +know the stack pointers are not shared + + align:start position:0% +know the stack pointers are not shared + + + align:start position:0% +know the stack pointers are not shared +there's really no + + align:start position:0% +there's really no + + + align:start position:0% +there's really no +problem with regard to col crash + + align:start position:0% +problem with regard to col crash + + + align:start position:0% +problem with regard to col crash +bringing the callar + + align:start position:0% +bringing the callar + + + align:start position:0% +bringing the callar +down of course we now need a way by + + align:start position:0% +down of course we now need a way by + + + align:start position:0% +down of course we now need a way by +which the client can communicate its + + align:start position:0% +which the client can communicate its + + + align:start position:0% +which the client can communicate its +arguments to the service and the service + + align:start position:0% +arguments to the service and the service + + + align:start position:0% +arguments to the service and the service +can communicate its arguments back to + + align:start position:0% +can communicate its arguments back to + + + align:start position:0% +can communicate its arguments back to +the client previously we did the first + + align:start position:0% +the client previously we did the first + + + align:start position:0% +the client previously we did the first +one the arguments were communicated by + + align:start position:0% +one the arguments were communicated by + + + align:start position:0% +one the arguments were communicated by +putting them on the Shar on the on the + + align:start position:0% +putting them on the Shar on the on the + + + align:start position:0% +putting them on the Shar on the on the +memory using memory on the stack and + + align:start position:0% +memory using memory on the stack and + + + align:start position:0% +memory using memory on the stack and +um the answers were coming back to us + + align:start position:0% +um the answers were coming back to us + + + align:start position:0% +um the answers were coming back to us +with from register we don't have that + + align:start position:0% +with from register we don't have that + + + align:start position:0% +with from register we don't have that +shared State anymore so we're going to + + align:start position:0% +shared State anymore so we're going to + + + align:start position:0% +shared State anymore so we're going to +have to implement that um using messages + + align:start position:0% +have to implement that um using messages + + + align:start position:0% +have to implement that um using messages +and we're going to take these messages + + align:start position:0% +and we're going to take these messages + + + align:start position:0% +and we're going to take these messages +use the communication path abstraction + + align:start position:0% +use the communication path abstraction + + + align:start position:0% +use the communication path abstraction +and send messages from the client to the + + align:start position:0% +and send messages from the client to the + + + align:start position:0% +and send messages from the client to the +service so imagine that time flows down + + align:start position:0% +service so imagine that time flows down + + + align:start position:0% +service so imagine that time flows down +downwards starting from when the client + + align:start position:0% +downwards starting from when the client + + + align:start position:0% +downwards starting from when the client +invokes the + + align:start position:0% +invokes the + + + align:start position:0% +invokes the +service you know a message is sent from + + align:start position:0% +service you know a message is sent from + + + align:start position:0% +service you know a message is sent from +this C sends a message to the service + + align:start position:0% +this C sends a message to the service + + + align:start position:0% +this C sends a message to the service +saying you know here's all the arguments + + align:start position:0% +saying you know here's all the arguments + + + align:start position:0% +saying you know here's all the arguments +and here's the procedure that I want you + + align:start position:0% +and here's the procedure that I want you + + + align:start position:0% +and here's the procedure that I want you +to run and it takes that information up + + align:start position:0% +to run and it takes that information up + + + align:start position:0% +to run and it takes that information up +somehow packages it up into a message + + align:start position:0% +somehow packages it up into a message + + + align:start position:0% +somehow packages it up into a message +and call send okay and the assumption is + + align:start position:0% +and call send okay and the assumption is + + + align:start position:0% +and call send okay and the assumption is +that the client somehow already knows + + align:start position:0% +that the client somehow already knows + + + align:start position:0% +that the client somehow already knows +something about the name of the service + + align:start position:0% +something about the name of the service + + + align:start position:0% +something about the name of the service +or the location of the service um you + + align:start position:0% +or the location of the service um you + + + align:start position:0% +or the location of the service um you +know that's outside of the scope of the + + align:start position:0% +know that's outside of the scope of the + + + align:start position:0% +know that's outside of the scope of the +current discussion um let's pretend + + align:start position:0% +current discussion um let's pretend + + + align:start position:0% +current discussion um let's pretend +somebody tells you that here's where the + + align:start position:0% +somebody tells you that here's where the + + + align:start position:0% +somebody tells you that here's where the +service is running that can you know run + + align:start position:0% +service is running that can you know run + + + align:start position:0% +service is running that can you know run +this function for you so takes the take + + align:start position:0% +this function for you so takes the take + + + align:start position:0% +this function for you so takes the take +the arguments and the name of the + + align:start position:0% +the arguments and the name of the + + + align:start position:0% +the arguments and the name of the +procedure packages it up to a message + + align:start position:0% +procedure packages it up to a message + + + align:start position:0% +procedure packages it up to a message +and sends it across when the service + + align:start position:0% +and sends it across when the service + + + align:start position:0% +and sends it across when the service +gets the message it validates the + + align:start position:0% +gets the message it validates the + + + align:start position:0% +gets the message it validates the +message to make sure that it's the right + + align:start position:0% +message to make sure that it's the right + + + align:start position:0% +message to make sure that it's the right +sizes and you know it's not too big and + + align:start position:0% +sizes and you know it's not too big and + + + align:start position:0% +sizes and you know it's not too big and +so + + align:start position:0% +so + + + align:start position:0% +so +on and then it takes this message and + + align:start position:0% +on and then it takes this message and + + + align:start position:0% +on and then it takes this message and +then does some processing on that + + align:start position:0% +then does some processing on that + + + align:start position:0% +then does some processing on that +message the technical term for it is + + align:start position:0% +message the technical term for it is + + + align:start position:0% +message the technical term for it is +going to be called unmarshaling because + + align:start position:0% +going to be called unmarshaling because + + + align:start position:0% +going to be called unmarshaling because +when we took these arguments and put + + align:start position:0% +when we took these arguments and put + + + align:start position:0% +when we took these arguments and put +into a message that procedure that + + align:start position:0% +into a message that procedure that + + + align:start position:0% +into a message that procedure that +process is called marshalling uh the + + align:start position:0% +process is called marshalling uh the + + + align:start position:0% +process is called marshalling uh the +service is going to unmarshal this + + align:start position:0% +service is going to unmarshal this + + + align:start position:0% +service is going to unmarshal this +message and obtain the actual arguments + + align:start position:0% +message and obtain the actual arguments + + + align:start position:0% +message and obtain the actual arguments +in the name of the procedure and then + + align:start position:0% +in the name of the procedure and then + + + align:start position:0% +in the name of the procedure and then +it's going to run + + align:start position:0% + + + + align:start position:0% + +it I don't know if it's one L or two + + align:start position:0% +it I don't know if it's one L or two + + + align:start position:0% +it I don't know if it's one L or two +L's non Marshal and then it's going to + + align:start position:0% +L's non Marshal and then it's going to + + + align:start position:0% +L's non Marshal and then it's going to +run the procedure that's named here it's + + align:start position:0% +run the procedure that's named here it's + + + align:start position:0% +run the procedure that's named here it's +going to find the answer and then when + + align:start position:0% +going to find the answer and then when + + + align:start position:0% +going to find the answer and then when +it gets the answer it does the same + + align:start position:0% +it gets the answer it does the same + + + align:start position:0% +it gets the answer it does the same +thing back it puts it back in a message + + align:start position:0% +thing back it puts it back in a message + + + align:start position:0% +thing back it puts it back in a message +and sends it across to the client and + + align:start position:0% +and sends it across to the client and + + + align:start position:0% +and sends it across to the client and +now the client's waiting for this + + align:start position:0% +now the client's waiting for this + + + align:start position:0% +now the client's waiting for this +message because it had sent off this um + + align:start position:0% +message because it had sent off this um + + + align:start position:0% +message because it had sent off this um +message to the service to run this thing + + align:start position:0% +message to the service to run this thing + + + align:start position:0% +message to the service to run this thing +uh it gets this answer back it does the + + align:start position:0% +uh it gets this answer back it does the + + + align:start position:0% +uh it gets this answer back it does the +same thing it you know takes the message + + align:start position:0% +same thing it you know takes the message + + + align:start position:0% +same thing it you know takes the message +and then it recovers the answer from it + + align:start position:0% +and then it recovers the answer from it + + + align:start position:0% +and then it recovers the answer from it +and then it runs + + align:start position:0% + + + + align:start position:0% + +continues so this is the basic idea in + + align:start position:0% +continues so this is the basic idea in + + + align:start position:0% +continues so this is the basic idea in +client server + + align:start position:0% +client server + + + align:start position:0% +client server +organization and the way in which we + + align:start position:0% +organization and the way in which we + + + align:start position:0% +organization and the way in which we +solve this problem is that these two + + align:start position:0% +solve this problem is that these two + + + align:start position:0% +solve this problem is that these two +problems are solved because the colleag + + align:start position:0% +problems are solved because the colleag + + + align:start position:0% +problems are solved because the colleag +can't really corrupt the stack or the + + align:start position:0% +can't really corrupt the stack or the + + + align:start position:0% +can't really corrupt the stack or the +stack pointer or anything else that in + + align:start position:0% +stack pointer or anything else that in + + + align:start position:0% +stack pointer or anything else that in +this model would have affected the + + align:start position:0% +this model would have affected the + + + align:start position:0% +this model would have affected the +caller and because we put them two + + align:start position:0% +caller and because we put them two + + + align:start position:0% +caller and because we put them two +physically different computers and + + align:start position:0% +physically different computers and + + + align:start position:0% +physically different computers and +hooked them up with a you know let's say + + align:start position:0% +hooked them up with a you know let's say + + + align:start position:0% +hooked them up with a you know let's say +wire um the service crashing does not + + align:start position:0% +wire um the service crashing does not + + + align:start position:0% +wire um the service crashing does not +actually bring the client if the service + + align:start position:0% +actually bring the client if the service + + + align:start position:0% +actually bring the client if the service +decides that it you know it crashes then + + align:start position:0% +decides that it you know it crashes then + + + align:start position:0% +decides that it you know it crashes then +the client actually doesn't come + + align:start position:0% +the client actually doesn't come + + + align:start position:0% +the client actually doesn't come +crashing down of course the client has + + align:start position:0% +crashing down of course the client has + + + align:start position:0% +crashing down of course the client has +to somehow have a plan by which it knows + + align:start position:0% +to somehow have a plan by which it knows + + + align:start position:0% +to somehow have a plan by which it knows +that the service is still you know whe + + align:start position:0% +that the service is still you know whe + + + align:start position:0% +that the service is still you know whe +for example the client has to know + + align:start position:0% +for example the client has to know + + + align:start position:0% +for example the client has to know +whether the service is crashed or + + align:start position:0% +whether the service is crashed or + + + align:start position:0% +whether the service is crashed or +whether the service is just taking a + + align:start position:0% +whether the service is just taking a + + + align:start position:0% +whether the service is just taking a +long time to run something um that's + + align:start position:0% +long time to run something um that's + + + align:start position:0% +long time to run something um that's +something we have to address and we will + + align:start position:0% +something we have to address and we will + + + align:start position:0% +something we have to address and we will +in a bit but as long as the client's + + align:start position:0% +in a bit but as long as the client's + + + align:start position:0% +in a bit but as long as the client's +able to do that a service going away + + align:start position:0% +able to do that a service going away + + + align:start position:0% +able to do that a service going away +crashing is not really going to bring + + align:start position:0% +crashing is not really going to bring + + + align:start position:0% +crashing is not really going to bring +the color of the client um down with + + align:start position:0% +the color of the client um down with + + + align:start position:0% +the color of the client um down with +it so some properties of this + + align:start position:0% +it so some properties of this + + + align:start position:0% +it so some properties of this +organization are first of all that it's + + align:start position:0% +organization are first of all that it's + + + align:start position:0% +organization are first of all that it's +modular it has essentially the same + + align:start position:0% +modular it has essentially the same + + + align:start position:0% +modular it has essentially the same +modularity as as we had with procedures + + align:start position:0% +modularity as as we had with procedures + + + align:start position:0% +modularity as as we had with procedures +because if you had enough computers you + + align:start position:0% +because if you had enough computers you + + + align:start position:0% +because if you had enough computers you +could all of the different procedures on + + align:start position:0% +could all of the different procedures on + + + align:start position:0% +could all of the different procedures on +different computers you know all of the + + align:start position:0% +different computers you know all of the + + + align:start position:0% +different computers you know all of the +colar col relationships and you can + + align:start position:0% +colar col relationships and you can + + + align:start position:0% +colar col relationships and you can +preserve essentially the same modularity + + align:start position:0% +preserve essentially the same modularity + + + align:start position:0% +preserve essentially the same modularity +that you had um + + align:start position:0% + + + + align:start position:0% + +before moreover this modularity has a + + align:start position:0% +before moreover this modularity has a + + + align:start position:0% +before moreover this modularity has a +different adjective in front of it + + align:start position:0% +different adjective in front of it + + + align:start position:0% +different adjective in front of it +different from soft this modularity is + + align:start position:0% + + + + align:start position:0% + +enforced what that means is not only are + + align:start position:0% +enforced what that means is not only are + + + align:start position:0% +enforced what that means is not only are +you not only is it a modular + + align:start position:0% +you not only is it a modular + + + align:start position:0% +you not only is it a modular +organization it's one where errors of + + align:start position:0% +organization it's one where errors of + + + align:start position:0% +organization it's one where errors of +you know for example um things where one + + align:start position:0% +you know for example um things where one + + + align:start position:0% +you know for example um things where one +module fails or crashes this not bring + + align:start position:0% +module fails or crashes this not bring + + + align:start position:0% +module fails or crashes this not bring +the other one come crashing down so the + + align:start position:0% +the other one come crashing down so the + + + align:start position:0% +the other one come crashing down so the +modularity is more enforced than when + + align:start position:0% +modularity is more enforced than when + + + align:start position:0% +modularity is more enforced than when +they were both running on the same + + align:start position:0% +they were both running on the same + + + align:start position:0% +they were both running on the same +computer using Pro the procedure + + align:start position:0% +computer using Pro the procedure + + + align:start position:0% +computer using Pro the procedure +interface and the third property of this + + align:start position:0% +interface and the third property of this + + + align:start position:0% +interface and the third property of this +kind of modularity is something I've + + align:start position:0% +kind of modularity is something I've + + + align:start position:0% +kind of modularity is something I've +already mentioned it relies + + align:start position:0% +already mentioned it relies + + + align:start position:0% +already mentioned it relies +on the message abstraction um actually + + align:start position:0% +on the message abstraction um actually + + + align:start position:0% +on the message abstraction um actually +the communication path + + align:start position:0% + + + + align:start position:0% + +abstraction um the client and service + + align:start position:0% +abstraction um the client and service + + + align:start position:0% +abstraction um the client and service +communicate with each other through + + align:start position:0% +communicate with each other through + + + align:start position:0% +communicate with each other through +messages and these aren't AR messages + + align:start position:0% +messages and these aren't AR messages + + + align:start position:0% +messages and these aren't AR messages +you can't just sort of take an you know + + align:start position:0% +you can't just sort of take an you know + + + align:start position:0% +you can't just sort of take an you know +a random string of bites and send it to + + align:start position:0% +a random string of bites and send it to + + + align:start position:0% +a random string of bites and send it to +the service um it's actually messages + + align:start position:0% +the service um it's actually messages + + + align:start position:0% +the service um it's actually messages +that correspond to a particular format + + align:start position:0% +that correspond to a particular format + + + align:start position:0% +that correspond to a particular format +and these are agreed upon in advance so + + align:start position:0% +and these are agreed upon in advance so + + + align:start position:0% +and these are agreed upon in advance so +that way the service isn't surprised and + + align:start position:0% +that way the service isn't surprised and + + + align:start position:0% +that way the service isn't surprised and +the client isn't surprised when um you + + align:start position:0% +the client isn't surprised when um you + + + align:start position:0% +the client isn't surprised when um you +know messages that don't conform to that + + align:start position:0% +know messages that don't conform to that + + + align:start position:0% +know messages that don't conform to that +pattern arrive I mean you know exactly + + align:start position:0% +pattern arrive I mean you know exactly + + + align:start position:0% +pattern arrive I mean you know exactly +what kind of message is going to arrive + + align:start position:0% +what kind of message is going to arrive + + + align:start position:0% +what kind of message is going to arrive +and anything that doesn't conform to + + align:start position:0% +and anything that doesn't conform to + + + align:start position:0% +and anything that doesn't conform to +what's agreed upon in advance is + + align:start position:0% +what's agreed upon in advance is + + + align:start position:0% +what's agreed upon in advance is +rejected but you basically make it so + + align:start position:0% +rejected but you basically make it so + + + align:start position:0% +rejected but you basically make it so +that you explicitly declare the nature + + align:start position:0% +that you explicitly declare the nature + + + align:start position:0% +that you explicitly declare the nature +of these messages much like you did the + + align:start position:0% +of these messages much like you did the + + + align:start position:0% +of these messages much like you did the +nature of the procedural + + align:start position:0% +nature of the procedural + + + align:start position:0% +nature of the procedural +interface but now because you physically + + align:start position:0% +interface but now because you physically + + + align:start position:0% +interface but now because you physically +separated it you have a more enforced + + align:start position:0% +separated it you have a more enforced + + + align:start position:0% +separated it you have a more enforced +modularity than in the previous + + align:start position:0% + + + + align:start position:0% + +model of course nothing comes for free + + align:start position:0% +model of course nothing comes for free + + + align:start position:0% +model of course nothing comes for free +it's not like you've got this enforced + + align:start position:0% +it's not like you've got this enforced + + + align:start position:0% +it's not like you've got this enforced +modularity and you have all of these + + align:start position:0% +modularity and you have all of these + + + align:start position:0% +modularity and you have all of these +nice properties that you did before um + + align:start position:0% +nice properties that you did before um + + + align:start position:0% +nice properties that you did before um +of um you know here you had a nice + + align:start position:0% +of um you know here you had a nice + + + align:start position:0% +of um you know here you had a nice +property that the colag could has the + + align:start position:0% +property that the colag could has the + + + align:start position:0% +property that the colag could has the +property that either it when it runs and + + align:start position:0% +property that either it when it runs and + + + align:start position:0% +property that either it when it runs and +it returns to you you know exactly what + + align:start position:0% +it returns to you you know exactly what + + + align:start position:0% +it returns to you you know exactly what +happened and if it doesn't return you + + align:start position:0% +happened and if it doesn't return you + + + align:start position:0% +happened and if it doesn't return you +know that you know you usually come + + align:start position:0% +know that you know you usually come + + + align:start position:0% +know that you know you usually come +crashing down if the collie doesn't + + align:start position:0% +crashing down if the collie doesn't + + + align:start position:0% +crashing down if the collie doesn't +return it means that control never comes + + align:start position:0% +return it means that control never comes + + + align:start position:0% +return it means that control never comes +back to the caller so it's not like the + + align:start position:0% +back to the caller so it's not like the + + + align:start position:0% +back to the caller so it's not like the +caller has to is left wondering what + + align:start position:0% +caller has to is left wondering what + + + align:start position:0% +caller has to is left wondering what +really happened because the caller + + align:start position:0% +really happened because the caller + + + align:start position:0% +really happened because the caller +doesn't get control + + align:start position:0% +doesn't get control + + + align:start position:0% +doesn't get control +again here you have a problem if the + + align:start position:0% +again here you have a problem if the + + + align:start position:0% +again here you have a problem if the +caller if the service if the colleag the + + align:start position:0% +caller if the service if the colleag the + + + align:start position:0% +caller if the service if the colleag the +service doesn't return back to the + + align:start position:0% +service doesn't return back to the + + + align:start position:0% +service doesn't return back to the +client the client actually doesn't know + + align:start position:0% +client the client actually doesn't know + + + align:start position:0% +client the client actually doesn't know +what's going on um when when you have + + align:start position:0% +what's going on um when when you have + + + align:start position:0% +what's going on um when when you have +two machines two computers connected + + align:start position:0% +two machines two computers connected + + + align:start position:0% +two machines two computers connected +over wire or over a network it's + + align:start position:0% +over wire or over a network it's + + + align:start position:0% +over wire or over a network it's +extremely hard to distinguish between a + + align:start position:0% +extremely hard to distinguish between a + + + align:start position:0% +extremely hard to distinguish between a +service running really really really + + align:start position:0% +service running really really really + + + align:start position:0% +service running really really really +slow and a service that's gone + + align:start position:0% +slow and a service that's gone + + + align:start position:0% +slow and a service that's gone +away and we'll revisit this few time a + + align:start position:0% +away and we'll revisit this few time a + + + align:start position:0% +away and we'll revisit this few time a +few different times in this course but + + align:start position:0% +few different times in this course but + + + align:start position:0% +few different times in this course but +it's going to be essentially impossible + + align:start position:0% +it's going to be essentially impossible + + + align:start position:0% +it's going to be essentially impossible +for us to tell for sure um although + + align:start position:0% +for us to tell for sure um although + + + align:start position:0% +for us to tell for sure um although +we're going to very hard it's going to + + align:start position:0% +we're going to very hard it's going to + + + align:start position:0% +we're going to very hard it's going to +be really hard for us to tell for sure + + align:start position:0% +be really hard for us to tell for sure + + + align:start position:0% +be really hard for us to tell for sure +whether something exactly happened and + + align:start position:0% +whether something exactly happened and + + + align:start position:0% +whether something exactly happened and +if the service didn't return we don't + + align:start position:0% +if the service didn't return we don't + + + align:start position:0% +if the service didn't return we don't +really know for sure without much more + + align:start position:0% +really know for sure without much more + + + align:start position:0% +really know for sure without much more +Machinery whether it was just that the + + align:start position:0% +Machinery whether it was just that the + + + align:start position:0% +Machinery whether it was just that the +service is still running or whether it's + + align:start position:0% +service is still running or whether it's + + + align:start position:0% +service is still running or whether it's +crashed and you know we're just + + align:start position:0% +crashed and you know we're just + + + align:start position:0% +crashed and you know we're just +waiting and so this organization + + align:start position:0% +waiting and so this organization + + + align:start position:0% +waiting and so this organization +requires u a timer at the client and + + align:start position:0% +requires u a timer at the client and + + + align:start position:0% +requires u a timer at the client and +there are many names given to this timer + + align:start position:0% +there are many names given to this timer + + + align:start position:0% +there are many names given to this timer +I mean people call them keep Alives or + + align:start position:0% +I mean people call them keep Alives or + + + align:start position:0% +I mean people call them keep Alives or +people um call them with various names + + align:start position:0% +people um call them with various names + + + align:start position:0% +people um call them with various names +I'm going to call it a watchdog + + align:start position:0% +I'm going to call it a watchdog + + + align:start position:0% +I'm going to call it a watchdog +timer where the client has to keep track + + align:start position:0% +timer where the client has to keep track + + + align:start position:0% +timer where the client has to keep track +using a watchdog or some kind of a timer + + align:start position:0% +using a watchdog or some kind of a timer + + + align:start position:0% +using a watchdog or some kind of a timer +um of the service and if the service + + align:start position:0% +um of the service and if the service + + + align:start position:0% +um of the service and if the service +doesn't return within a certain period + + align:start position:0% +doesn't return within a certain period + + + align:start position:0% +doesn't return within a certain period +of time um the client has to time out + + align:start position:0% +of time um the client has to time out + + + align:start position:0% +of time um the client has to time out +and say well the service didn't return + + align:start position:0% +and say well the service didn't return + + + align:start position:0% +and say well the service didn't return +and I'm not quite sure what happened it + + align:start position:0% +and I'm not quite sure what happened it + + + align:start position:0% +and I'm not quite sure what happened it +might be that the procedure I wanted + + align:start position:0% +might be that the procedure I wanted + + + align:start position:0% +might be that the procedure I wanted +executed ran but I didn't get the answer + + align:start position:0% +executed ran but I didn't get the answer + + + align:start position:0% +executed ran but I didn't get the answer +or it might be that you know the + + align:start position:0% +or it might be that you know the + + + align:start position:0% +or it might be that you know the +procedure didn't get executed at all and + + align:start position:0% +procedure didn't get executed at all and + + + align:start position:0% +procedure didn't get executed at all and +I have to deal with it and you might + + align:start position:0% +I have to deal with it and you might + + + align:start position:0% +I have to deal with it and you might +deal with it by retrying the procedure + + align:start position:0% +deal with it by retrying the procedure + + + align:start position:0% +deal with it by retrying the procedure +or you might contact another service + + align:start position:0% +or you might contact another service + + + align:start position:0% +or you might contact another service +which provides the same function it but + + align:start position:0% +which provides the same function it but + + + align:start position:0% +which provides the same function it but +the client has to deal with all of + + align:start position:0% + + + + align:start position:0% + +that so fundamental to this client + + align:start position:0% +that so fundamental to this client + + + align:start position:0% +that so fundamental to this client +organization is a no is the notion um of + + align:start position:0% +organization is a no is the notion um of + + + align:start position:0% +organization is a no is the notion um of +a + + align:start position:0% +a + + + align:start position:0% +a +timeout and we didn't have that here + + align:start position:0% +timeout and we didn't have that here + + + align:start position:0% +timeout and we didn't have that here +because + + align:start position:0% +because + + + align:start position:0% +because +here if the colleag decides that it's + + align:start position:0% +here if the colleag decides that it's + + + align:start position:0% +here if the colleag decides that it's +just going to continue on and not return + + align:start position:0% +just going to continue on and not return + + + align:start position:0% +just going to continue on and not return +the caller never gets control back so it + + align:start position:0% +the caller never gets control back so it + + + align:start position:0% +the caller never gets control back so it +doesn't have this decision to make there + + align:start position:0% +doesn't have this decision to make there + + + align:start position:0% +doesn't have this decision to make there +is no such notion of a watch do that we + + align:start position:0% +is no such notion of a watch do that we + + + align:start position:0% +is no such notion of a watch do that we +have to worry about in this other + + align:start position:0% +have to worry about in this other + + + align:start position:0% +have to worry about in this other +organization + + align:start position:0% + + + + align:start position:0% + +so another nice property of this client + + align:start position:0% +so another nice property of this client + + + align:start position:0% +so another nice property of this client +service organization is that so far + + align:start position:0% +service organization is that so far + + + align:start position:0% +service organization is that so far +we've presented it in the context of the + + align:start position:0% +we've presented it in the context of the + + + align:start position:0% +we've presented it in the context of the +client and the service being modularized + + align:start position:0% +client and the service being modularized + + + align:start position:0% +client and the service being modularized +from each other and we've enforced + + align:start position:0% +from each other and we've enforced + + + align:start position:0% +from each other and we've enforced +modularity between the client and the + + align:start position:0% +modularity between the client and the + + + align:start position:0% +modularity between the client and the +service but in fact there's another nice + + align:start position:0% +service but in fact there's another nice + + + align:start position:0% +service but in fact there's another nice +property to it which is that a client + + align:start position:0% +property to it which is that a client + + + align:start position:0% +property to it which is that a client +service organization allows us to design + + align:start position:0% +service organization allows us to design + + + align:start position:0% +service organization allows us to design +modules and Design Systems where clients + + align:start position:0% +modules and Design Systems where clients + + + align:start position:0% +modules and Design Systems where clients +get modularized from each other the + + align:start position:0% +get modularized from each other the + + + align:start position:0% +get modularized from each other the +clients we can achieve soft modularity + + align:start position:0% +clients we can achieve soft modularity + + + align:start position:0% +clients we can achieve soft modularity +by protecting clients from + + align:start position:0% + + + + align:start position:0% + +each the idea here is if you have many + + align:start position:0% +each the idea here is if you have many + + + align:start position:0% +each the idea here is if you have many +clients all of which want to use a given + + align:start position:0% +clients all of which want to use a given + + + align:start position:0% +clients all of which want to use a given +service for example U there's some + + align:start position:0% +service for example U there's some + + + align:start position:0% +service for example U there's some +there's a service that's let's say uh + + align:start position:0% +there's a service that's let's say uh + + + align:start position:0% +there's a service that's let's say uh +implemented by your bank and what it + + align:start position:0% +implemented by your bank and what it + + + align:start position:0% +implemented by your bank and what it +does is it's the service that deals with + + align:start position:0% +does is it's the service that deals with + + + align:start position:0% +does is it's the service that deals with +managing your accounts and you can move + + align:start position:0% +managing your accounts and you can move + + + align:start position:0% +managing your accounts and you can move +money between accounts and it'll tell + + align:start position:0% +money between accounts and it'll tell + + + align:start position:0% +money between accounts and it'll tell +you your account balance and so + + align:start position:0% +you your account balance and so + + + align:start position:0% +you your account balance and so +on you can Implement that as one service + + align:start position:0% +on you can Implement that as one service + + + align:start position:0% +on you can Implement that as one service +and many many clients can share the same + + align:start position:0% +and many many clients can share the same + + + align:start position:0% +and many many clients can share the same +service now all of the clients trust the + + align:start position:0% +service now all of the clients trust the + + + align:start position:0% +service now all of the clients trust the +service because I mean if you're a + + align:start position:0% +service because I mean if you're a + + + align:start position:0% +service because I mean if you're a +customer of a bank you're you know and + + align:start position:0% +customer of a bank you're you know and + + + align:start position:0% +customer of a bank you're you know and +you're using your browser to to look for + + align:start position:0% +you're using your browser to to look for + + + align:start position:0% +you're using your browser to to look for +your account balance that means you sort + + align:start position:0% +your account balance that means you sort + + + align:start position:0% +your account balance that means you sort +of trust the bank and all of the clients + + align:start position:0% +of trust the bank and all of the clients + + + align:start position:0% +of trust the bank and all of the clients +trust the service but the clients sure + + align:start position:0% +trust the service but the clients sure + + + align:start position:0% +trust the service but the clients sure +don't trust each + + align:start position:0% +don't trust each + + + align:start position:0% +don't trust each +other and the nice thing about this + + align:start position:0% +other and the nice thing about this + + + align:start position:0% +other and the nice thing about this +organization is that you can use the + + align:start position:0% +organization is that you can use the + + + align:start position:0% +organization is that you can use the +service um in the form of an + + align:start position:0% +service um in the form of an + + + align:start position:0% +service um in the form of an +intermediary that allows the clients to + + align:start position:0% +intermediary that allows the clients to + + + align:start position:0% +intermediary that allows the clients to +be separated from each other + + align:start position:0% +be separated from each other + + + align:start position:0% +be separated from each other +um Each of which can use the service but + + align:start position:0% +um Each of which can use the service but + + + align:start position:0% +um Each of which can use the service but +the clients don't have to trust each + + align:start position:0% +the clients don't have to trust each + + + align:start position:0% +the clients don't have to trust each +other and clients don't really have to + + align:start position:0% +other and clients don't really have to + + + align:start position:0% +other and clients don't really have to +um you know know about each other's uh + + align:start position:0% +um you know know about each other's uh + + + align:start position:0% +um you know know about each other's uh +information + + align:start position:0% +information + + + align:start position:0% +information +and this idea of using a a service to + + align:start position:0% +and this idea of using a a service to + + + align:start position:0% +and this idea of using a a service to +modularize clients from each other uh is + + align:start position:0% +modularize clients from each other uh is + + + align:start position:0% +modularize clients from each other uh is +called a trusted + + align:start position:0% + + + + align:start position:0% + +intermediary there's many examples of + + align:start position:0% +intermediary there's many examples of + + + align:start position:0% +intermediary there's many examples of +trusted intermediaries that um we'll see + + align:start position:0% +trusted intermediaries that um we'll see + + + align:start position:0% +trusted intermediaries that um we'll see +in this in this course in fact + + align:start position:0% +in this in this course in fact + + + align:start position:0% +in this in this course in fact +tomorrow's recitation on the X Windows + + align:start position:0% +tomorrow's recitation on the X Windows + + + align:start position:0% +tomorrow's recitation on the X Windows +system has a system where your computer + + align:start position:0% +system has a system where your computer + + + align:start position:0% +system has a system where your computer +display is going to be managed by a + + align:start position:0% +display is going to be managed by a + + + align:start position:0% +display is going to be managed by a +service called the by the X window + + align:start position:0% +service called the by the X window + + + align:start position:0% +service called the by the X window +system and there are many clients that + + align:start position:0% +system and there are many clients that + + + align:start position:0% +system and there are many clients that +are going to use that service and the + + align:start position:0% +are going to use that service and the + + + align:start position:0% +are going to use that service and the +clients actually you know don't actually + + align:start position:0% +clients actually you know don't actually + + + align:start position:0% +clients actually you know don't actually +trust each other and they don't really + + align:start position:0% +trust each other and they don't really + + + align:start position:0% +trust each other and they don't really +they want to get modularized away from + + align:start position:0% +they want to get modularized away from + + + align:start position:0% +they want to get modularized away from +each other and the X Windows system as a + + align:start position:0% +each other and the X Windows system as a + + + align:start position:0% +each other and the X Windows system as a +trusted intermediary deals with that it + + align:start position:0% +trusted intermediary deals with that it + + + align:start position:0% +trusted intermediary deals with that it +manages this resource your display and + + align:start position:0% +manages this resource your display and + + + align:start position:0% +manages this resource your display and +it arranges for the clients to be + + align:start position:0% +it arranges for the clients to be + + + align:start position:0% +it arranges for the clients to be +designed each independent from the + + align:start position:0% +designed each independent from the + + + align:start position:0% +designed each independent from the +other and in general uh we're going to + + align:start position:0% +other and in general uh we're going to + + + align:start position:0% +other and in general uh we're going to +see in the next few lectures many + + align:start position:0% +see in the next few lectures many + + + align:start position:0% +see in the next few lectures many +examples of your operating system being + + align:start position:0% +examples of your operating system being + + + align:start position:0% +examples of your operating system being +a trusted intermediary um arranging for + + align:start position:0% +a trusted intermediary um arranging for + + + align:start position:0% +a trusted intermediary um arranging for +many different clients to use some + + align:start position:0% +many different clients to use some + + + align:start position:0% +many different clients to use some +resource on your computer like the + + align:start position:0% +resource on your computer like the + + + align:start position:0% +resource on your computer like the +processor or the memory and or the disk + + align:start position:0% +processor or the memory and or the disk + + + align:start position:0% +processor or the memory and or the disk +and our architecture for the operating + + align:start position:0% +and our architecture for the operating + + + align:start position:0% +and our architecture for the operating +system is going to end up being in the + + align:start position:0% +system is going to end up being in the + + + align:start position:0% +system is going to end up being in the +form of these trusted intermediaries + + align:start position:0% + + + + align:start position:0% + +so so far we've seen what the what + + align:start position:0% +so so far we've seen what the what + + + align:start position:0% +so so far we've seen what the what +client service organization means it + + align:start position:0% +client service organization means it + + + align:start position:0% +client service organization means it +means you have a client and a service + + align:start position:0% +means you have a client and a service + + + align:start position:0% +means you have a client and a service +and they communicate with messages using + + align:start position:0% +and they communicate with messages using + + + align:start position:0% +and they communicate with messages using +the communication path abstraction of + + align:start position:0% +the communication path abstraction of + + + align:start position:0% +the communication path abstraction of +send and receive um and we've seen some + + align:start position:0% +send and receive um and we've seen some + + + align:start position:0% +send and receive um and we've seen some +properties of client service + + align:start position:0% +properties of client service + + + align:start position:0% +properties of client service +organization but I haven't actually told + + align:start position:0% +organization but I haven't actually told + + + align:start position:0% +organization but I haven't actually told +you how to implement any of this stuff + + align:start position:0% +you how to implement any of this stuff + + + align:start position:0% +you how to implement any of this stuff +and so that's what we're going to do the + + align:start position:0% +and so that's what we're going to do the + + + align:start position:0% +and so that's what we're going to do the +rest of rest of today um and in fact + + align:start position:0% +rest of rest of today um and in fact + + + align:start position:0% +rest of rest of today um and in fact +we're going to continue with different + + align:start position:0% +we're going to continue with different + + + align:start position:0% +we're going to continue with different +ways of implementing um various forms of + + align:start position:0% +ways of implementing um various forms of + + + align:start position:0% +ways of implementing um various forms of +client service many times uh in the + + align:start position:0% + + + + align:start position:0% + +course so there are many ways to + + align:start position:0% +course so there are many ways to + + + align:start position:0% +course so there are many ways to +implement client service organization + + align:start position:0% +implement client service organization + + + align:start position:0% +implement client service organization +and all of them have to do with all of + + align:start position:0% +and all of them have to do with all of + + + align:start position:0% +and all of them have to do with all of +them involve different ways in which + + align:start position:0% +them involve different ways in which + + + align:start position:0% +them involve different ways in which +messages are sent between client and + + align:start position:0% +messages are sent between client and + + + align:start position:0% +messages are sent between client and +service + + align:start position:0% +service + + + align:start position:0% +service +a common way and a pretty standard way + + align:start position:0% +a common way and a pretty standard way + + + align:start position:0% +a common way and a pretty standard way +of implementing it is something called a + + align:start position:0% +of implementing it is something called a + + + align:start position:0% +of implementing it is something called a +remote procedure + + align:start position:0% + + + + align:start position:0% + +call there are many examples of remote + + align:start position:0% +call there are many examples of remote + + + align:start position:0% +call there are many examples of remote +procedure call systems I mean the the + + align:start position:0% +procedure call systems I mean the the + + + align:start position:0% +procedure call systems I mean the the +one of the most U common ones is + + align:start position:0% +one of the most U common ones is + + + align:start position:0% +one of the most U common ones is +something called the sun remote + + align:start position:0% +something called the sun remote + + + align:start position:0% +something called the sun remote +procedure call system or sun RPC um + + align:start position:0% +procedure call system or sun RPC um + + + align:start position:0% +procedure call system or sun RPC um +that's one example um there are many + + align:start position:0% +that's one example um there are many + + + align:start position:0% +that's one example um there are many +other examples as well well a more + + align:start position:0% +other examples as well well a more + + + align:start position:0% +other examples as well well a more +modern + + align:start position:0% +modern + + + align:start position:0% +modern +example which some of you may have heard + + align:start position:0% +example which some of you may have heard + + + align:start position:0% +example which some of you may have heard +of is a a relatively new system about 5 + + align:start position:0% +of is a a relatively new system about 5 + + + align:start position:0% +of is a a relatively new system about 5 +years old called XML + + align:start position:0% + + + + align:start position:0% + +RPC so if you've heard of buzzwords like + + align:start position:0% +RPC so if you've heard of buzzwords like + + + align:start position:0% +RPC so if you've heard of buzzwords like +web services and you know busino + + align:start position:0% +web services and you know busino + + + align:start position:0% +web services and you know busino +business interactions or busines to + + align:start position:0% +business interactions or busines to + + + align:start position:0% +business interactions or busines to +business um applications these things + + align:start position:0% +business um applications these things + + + align:start position:0% +business um applications these things +use something called XML RPC and you + + align:start position:0% +use something called XML RPC and you + + + align:start position:0% +use something called XML RPC and you +know there's the there's a lot of + + align:start position:0% +know there's the there's a lot of + + + align:start position:0% +know there's the there's a lot of +different three-letter acronyms and + + align:start position:0% +different three-letter acronyms and + + + align:start position:0% +different three-letter acronyms and +four-letter acronyms um this has led to + + align:start position:0% +four-letter acronyms um this has led to + + + align:start position:0% +four-letter acronyms um this has led to +something called soap which stands for + + align:start position:0% +something called soap which stands for + + + align:start position:0% +something called soap which stands for +the simple object access protocol um so + + align:start position:0% +the simple object access protocol um so + + + align:start position:0% +the simple object access protocol um so +there are many different ways of + + align:start position:0% +there are many different ways of + + + align:start position:0% +there are many different ways of +implementing uh RPC systems and you know + + align:start position:0% +implementing uh RPC systems and you know + + + align:start position:0% +implementing uh RPC systems and you know +on until last year or a couple of years + + align:start position:0% +on until last year or a couple of years + + + align:start position:0% +on until last year or a couple of years +ago we used to talk about sunrpc as an + + align:start position:0% +ago we used to talk about sunrpc as an + + + align:start position:0% +ago we used to talk about sunrpc as an +example in this in this class but I + + align:start position:0% +example in this in this class but I + + + align:start position:0% +example in this in this class but I +decided that's so 20th centuries so + + align:start position:0% +decided that's so 20th centuries so + + + align:start position:0% +decided that's so 20th centuries so +we're going to talk about XML RPC today + + align:start position:0% +we're going to talk about XML RPC today + + + align:start position:0% +we're going to talk about XML RPC today +um you know it has the property that's + + align:start position:0% +um you know it has the property that's + + + align:start position:0% +um you know it has the property that's +much more inefficient um but that's sort + + align:start position:0% +much more inefficient um but that's sort + + + align:start position:0% +much more inefficient um but that's sort +of keep keeping with the fact that + + align:start position:0% +of keep keeping with the fact that + + + align:start position:0% +of keep keeping with the fact that +computers have become faster we don't + + align:start position:0% +computers have become faster we don't + + + align:start position:0% +computers have become faster we don't +really have to worry in many cases about + + align:start position:0% +really have to worry in many cases about + + + align:start position:0% +really have to worry in many cases about +efficiency so we're going to talk a + + align:start position:0% +efficiency so we're going to talk a + + + align:start position:0% +efficiency so we're going to talk a +little bit about um how xmlrpc + + align:start position:0% + + + + align:start position:0% + +works so let me first show + + align:start position:0% + + + + align:start position:0% + +you program written what a client + + align:start position:0% +you program written what a client + + + align:start position:0% +you program written what a client +written with um this kind of RPC looks + + align:start position:0% +written with um this kind of RPC looks + + + align:start position:0% +written with um this kind of RPC looks +like um in jav it's going to show you a + + align:start position:0% +like um in jav it's going to show you a + + + align:start position:0% +like um in jav it's going to show you a +a code + + align:start position:0% + + + + align:start position:0% + +all right had to work hard to make sure + + align:start position:0% +all right had to work hard to make sure + + + align:start position:0% +all right had to work hard to make sure +it would fit on + + align:start position:0% +it would fit on + + + align:start position:0% +it would fit on +this okay um all right the way this + + align:start position:0% +this okay um all right the way this + + + align:start position:0% +this okay um all right the way this +thing works is actually very very + + align:start position:0% +thing works is actually very very + + + align:start position:0% +thing works is actually very very +simple um this uses uh something called + + align:start position:0% +simple um this uses uh something called + + + align:start position:0% +simple um this uses uh something called +the xmlc library that for Java that was + + align:start position:0% +the xmlc library that for Java that was + + + align:start position:0% +the xmlc library that for Java that was +written by um the Apache people tool and + + align:start position:0% +written by um the Apache people tool and + + + align:start position:0% +written by um the Apache people tool and +once you incorporate that Library your + + align:start position:0% +once you incorporate that Library your + + + align:start position:0% +once you incorporate that Library your +program becomes completely easy so let + + align:start position:0% +program becomes completely easy so let + + + align:start position:0% +program becomes completely easy so let +me just walk you through this what the + + align:start position:0% +me just walk you through this what the + + + align:start position:0% +me just walk you through this what the +the high level idea here is that it's + + align:start position:0% +the high level idea here is that it's + + + align:start position:0% +the high level idea here is that it's +sending um you know it's transferring + + align:start position:0% +sending um you know it's transferring + + + align:start position:0% +sending um you know it's transferring +money account to the other um you know + + align:start position:0% +money account to the other um you know + + + align:start position:0% +money account to the other um you know +through a that's run by the bank so the + + align:start position:0% +through a that's run by the bank so the + + + align:start position:0% +through a that's run by the bank so the +first line of this thing here um you + + align:start position:0% +first line of this thing here um you + + + align:start position:0% +first line of this thing here um you +know creates an xmlrpc object um an + + align:start position:0% +know creates an xmlrpc object um an + + + align:start position:0% +know creates an xmlrpc object um an +xmlrpc client object and what you give + + align:start position:0% +xmlrpc client object and what you give + + + align:start position:0% +xmlrpc client object and what you give +it is actually the name of the service + + align:start position:0% +it is actually the name of the service + + + align:start position:0% +it is actually the name of the service +so somebody has to tell you the name of + + align:start position:0% +so somebody has to tell you the name of + + + align:start position:0% +so somebody has to tell you the name of +the service and I don't want to get into + + align:start position:0% +the service and I don't want to get into + + + align:start position:0% +the service and I don't want to get into +the details of everything everything + + align:start position:0% +the details of everything everything + + + align:start position:0% +the details of everything everything +here but the basic idea is your back + + align:start position:0% +here but the basic idea is your back + + + align:start position:0% +here but the basic idea is your back +name.com colon 8080 is the name the DNS + + align:start position:0% +name.com colon 8080 is the name the DNS + + + align:start position:0% +name.com colon 8080 is the name the DNS +name at which the service runs and a + + align:start position:0% +name at which the service runs and a + + + align:start position:0% +name at which the service runs and a +port the thing about xmlrpc is that it + + align:start position:0% +port the thing about xmlrpc is that it + + + align:start position:0% +port the thing about xmlrpc is that it +runs over HTTP which is what you use to + + align:start position:0% +runs over HTTP which is what you use to + + + align:start position:0% +runs over HTTP which is what you use to +transfer objects um on the web and + + align:start position:0% +transfer objects um on the web and + + + align:start position:0% +transfer objects um on the web and +underneath I'll talk about how it's + + align:start position:0% +underneath I'll talk about how it's + + + align:start position:0% +underneath I'll talk about how it's +implemented underneath this is + + align:start position:0% +implemented underneath this is + + + align:start position:0% +implemented underneath this is +implemented using a standard method in + + align:start position:0% +implemented using a standard method in + + + align:start position:0% +implemented using a standard method in +HTTP called a post which allows a client + + align:start position:0% +HTTP called a post which allows a client + + + align:start position:0% +HTTP called a post which allows a client +normally HTTP has a get where you + + align:start position:0% +normally HTTP has a get where you + + + align:start position:0% +normally HTTP has a get where you +retrieve stuff but it also has a post + + align:start position:0% +retrieve stuff but it also has a post + + + align:start position:0% +retrieve stuff but it also has a post +that many of you are familiar with where + + align:start position:0% +that many of you are familiar with where + + + align:start position:0% +that many of you are familiar with where +the client can push some stuff to the + + align:start position:0% +the client can push some stuff to the + + + align:start position:0% +the client can push some stuff to the +service to the server and it just uses + + align:start position:0% +service to the server and it just uses + + + align:start position:0% +service to the server and it just uses +post um what's going on very easy you + + align:start position:0% +post um what's going on very easy you + + + align:start position:0% +post um what's going on very easy you +create a vector of um parameters and you + + align:start position:0% +create a vector of um parameters and you + + + align:start position:0% +create a vector of um parameters and you +fill that uh Vector in with you know in + + align:start position:0% +fill that uh Vector in with you know in + + + align:start position:0% +fill that uh Vector in with you know in +this case your account number um you + + align:start position:0% +this case your account number um you + + + align:start position:0% +this case your account number um you +know let's say here the idea is that you + + align:start position:0% +know let's say here the idea is that you + + + align:start position:0% +know let's say here the idea is that you +know your comp you know this sort of + + align:start position:0% +know your comp you know this sort of + + + align:start position:0% +know your comp you know this sort of +thing is very popular at big companies + + align:start position:0% +thing is very popular at big companies + + + align:start position:0% +thing is very popular at big companies +like Ford or Cisco which have thousands + + align:start position:0% +like Ford or Cisco which have thousands + + + align:start position:0% +like Ford or Cisco which have thousands +of suppliers and um they're always + + align:start position:0% +of suppliers and um they're always + + + align:start position:0% +of suppliers and um they're always +worried about and they never actually + + align:start position:0% +worried about and they never actually + + + align:start position:0% +worried about and they never actually +maintain a lot of inventory of their own + + align:start position:0% +maintain a lot of inventory of their own + + + align:start position:0% +maintain a lot of inventory of their own +so they're always trying to figure out + + align:start position:0% +so they're always trying to figure out + + + align:start position:0% +so they're always trying to figure out +the latest cost of any of their supplies + + align:start position:0% +the latest cost of any of their supplies + + + align:start position:0% +the latest cost of any of their supplies +and they using this web service like + + align:start position:0% +and they using this web service like + + + align:start position:0% +and they using this web service like +interface in fact this you know this is + + align:start position:0% +interface in fact this you know this is + + + align:start position:0% +interface in fact this you know this is +called also called a web service + + align:start position:0% +called also called a web service + + + align:start position:0% +called also called a web service +interface to communicate with their + + align:start position:0% +interface to communicate with their + + + align:start position:0% +interface to communicate with their +suppliers to always have + + align:start position:0% +suppliers to always have + + + align:start position:0% +suppliers to always have +latest whether their suppliers have any + + align:start position:0% +latest whether their suppliers have any + + + align:start position:0% +latest whether their suppliers have any +given item in stock and how much it + + align:start position:0% +given item in stock and how much it + + + align:start position:0% +given item in stock and how much it +costs and so let's pretend you've done + + align:start position:0% +costs and so let's pretend you've done + + + align:start position:0% +costs and so let's pretend you've done +that in your company and um you know + + align:start position:0% +that in your company and um you know + + + align:start position:0% +that in your company and um you know +you're trying to pay off um you know + + align:start position:0% +you're trying to pay off um you know + + + align:start position:0% +you're trying to pay off um you know +you're taking your supplier's account + + align:start position:0% +you're taking your supplier's account + + + align:start position:0% +you're taking your supplier's account +number and pay some money to him okay so + + align:start position:0% +number and pay some money to him okay so + + + align:start position:0% +number and pay some money to him okay so +in this case um whatever dollars is that + + align:start position:0% +in this case um whatever dollars is that + + + align:start position:0% +in this case um whatever dollars is that +is that argument um so you create your + + align:start position:0% +is that argument um so you create your + + + align:start position:0% +is that argument um so you create your +parameters and all you do at the end is + + align:start position:0% +parameters and all you do at the end is + + + align:start position:0% +parameters and all you do at the end is +you use this xmlrpc client object and + + align:start position:0% +you use this xmlrpc client object and + + + align:start position:0% +you use this xmlrpc client object and +invoke a it's it presents to you called + + align:start position:0% +invoke a it's it presents to you called + + + align:start position:0% +invoke a it's it presents to you called +execute and you give it two arguments + + align:start position:0% +execute and you give it two arguments + + + align:start position:0% +execute and you give it two arguments +the second argument is the parameters + + align:start position:0% +the second argument is the parameters + + + align:start position:0% +the second argument is the parameters +and the first argument is the name of + + align:start position:0% +and the first argument is the name of + + + align:start position:0% +and the first argument is the name of +the procedure that you wish to run on + + align:start position:0% +the procedure that you wish to run on + + + align:start position:0% +the procedure that you wish to run on +the service okay um that's in this case + + align:start position:0% +the service okay um that's in this case + + + align:start position:0% +the service okay um that's in this case +called money transfer so corresponding + + align:start position:0% +called money transfer so corresponding + + + align:start position:0% +called money transfer so corresponding +to this somewhat longer is a piece of + + align:start position:0% +to this somewhat longer is a piece of + + + align:start position:0% +to this somewhat longer is a piece of +code running on the service which + + align:start position:0% +code running on the service which + + + align:start position:0% +code running on the service which +implements the server side of it uh + + align:start position:0% +implements the server side of it uh + + + align:start position:0% +implements the server side of it uh +which has a basic basically it obtains + + align:start position:0% +which has a basic basically it obtains + + + align:start position:0% +which has a basic basically it obtains +the you know the gives message from the + + align:start position:0% +the you know the gives message from the + + + align:start position:0% +the you know the gives message from the +network calls an object that will + + align:start position:0% +network calls an object that will + + + align:start position:0% +network calls an object that will +unmarshal the arguments and then it'll + + align:start position:0% +unmarshal the arguments and then it'll + + + align:start position:0% +unmarshal the arguments and then it'll +execute money transfer all of which all + + align:start position:0% +execute money transfer all of which all + + + align:start position:0% +execute money transfer all of which all +done essent there's little that actually + + align:start position:0% +done essent there's little that actually + + + align:start position:0% +done essent there's little that actually +has to run on the service it's just a + + align:start position:0% +has to run on the service it's just a + + + align:start position:0% +has to run on the service it's just a +little bit longer than this + + align:start position:0% +little bit longer than this + + + align:start position:0% +little bit longer than this +um now this line here is a little is + + align:start position:0% +um now this line here is a little is + + + align:start position:0% +um now this line here is a little is +important that's the line on which you + + align:start position:0% +important that's the line on which you + + + align:start position:0% +important that's the line on which you +get your result in this case the result + + align:start position:0% +get your result in this case the result + + + align:start position:0% +get your result in this case the result +is a string you know it might tell you + + align:start position:0% +is a string you know it might tell you + + + align:start position:0% +is a string you know it might tell you +that I was I finished transferring X + + align:start position:0% +that I was I finished transferring X + + + align:start position:0% +that I was I finished transferring X +from this account to that account um or + + align:start position:0% +from this account to that account um or + + + align:start position:0% +from this account to that account um or +it might tell you I couldn't transfer + + align:start position:0% +it might tell you I couldn't transfer + + + align:start position:0% +it might tell you I couldn't transfer +and you know there was some kind of an + + align:start position:0% +and you know there was some kind of an + + + align:start position:0% +and you know there was some kind of an +error or um you might actually not get + + align:start position:0% +error or um you might actually not get + + + align:start position:0% +error or um you might actually not get +any answer in which case the library + + align:start position:0% +any answer in which case the library + + + align:start position:0% +any answer in which case the library +would actually in this case the + + align:start position:0% +would actually in this case the + + + align:start position:0% +would actually in this case the +underlying library that implements this + + align:start position:0% +underlying library that implements this + + + align:start position:0% +underlying library that implements this +remote procedure call would throw an + + align:start position:0% +remote procedure call would throw an + + + align:start position:0% +remote procedure call would throw an +exception that your code has to deal + + align:start position:0% +exception that your code has to deal + + + align:start position:0% +exception that your code has to deal +with and how you deal with it is a + + align:start position:0% +with and how you deal with it is a + + + align:start position:0% +with and how you deal with it is a +little tricky U because you don't quite + + align:start position:0% +little tricky U because you don't quite + + + align:start position:0% +little tricky U because you don't quite +know and we'll see this in a moment you + + align:start position:0% +know and we'll see this in a moment you + + + align:start position:0% +know and we'll see this in a moment you +don't quite know what happened when you + + align:start position:0% +don't quite know what happened when you + + + align:start position:0% +don't quite know what happened when you +know you didn't get an answer back from + + align:start position:0% +know you didn't get an answer back from + + + align:start position:0% +know you didn't get an answer back from +the service you don't know if service + + align:start position:0% +the service you don't know if service + + + align:start position:0% +the service you don't know if service +actually got your transfer request and + + align:start position:0% +actually got your transfer request and + + + align:start position:0% +actually got your transfer request and +you know crashed after that and you know + + align:start position:0% +you know crashed after that and you know + + + align:start position:0% +you know crashed after that and you know +it got the request it actually + + align:start position:0% +it got the request it actually + + + align:start position:0% +it got the request it actually +implemented the transfer and then + + align:start position:0% +implemented the transfer and then + + + align:start position:0% +implemented the transfer and then +crashed it just didn't send your + + align:start position:0% +crashed it just didn't send your + + + align:start position:0% +crashed it just didn't send your +response back so you're not quite sure + + align:start position:0% +response back so you're not quite sure + + + align:start position:0% +response back so you're not quite sure +whether you need to retry the request or + + align:start position:0% +whether you need to retry the request or + + + align:start position:0% +whether you need to retry the request or +not okay uh we'll actually see how to + + align:start position:0% +not okay uh we'll actually see how to + + + align:start position:0% +not okay uh we'll actually see how to +deal with the these issues um in in in a + + align:start position:0% +deal with the these issues um in in in a + + + align:start position:0% +deal with the these issues um in in in a +few + + align:start position:0% +few + + + align:start position:0% +few +minutes now there was one thing that's + + align:start position:0% +minutes now there was one thing that's + + + align:start position:0% +minutes now there was one thing that's +really important that about this line of + + align:start position:0% +really important that about this line of + + + align:start position:0% +really important that about this line of +code this line xmlrpc execute money + + align:start position:0% +code this line xmlrpc execute money + + + align:start position:0% +code this line xmlrpc execute money +transfer block that line of code + + align:start position:0% +transfer block that line of code + + + align:start position:0% +transfer block that line of code +actually is not something that runs on + + align:start position:0% +actually is not something that runs on + + + align:start position:0% +actually is not something that runs on +the + + align:start position:0% +the + + + align:start position:0% +the +service okay it's a local procedure call + + align:start position:0% +service okay it's a local procedure call + + + align:start position:0% +service okay it's a local procedure call +xmlrpc execute is a local procedure call + + align:start position:0% +xmlrpc execute is a local procedure call + + + align:start position:0% +xmlrpc execute is a local procedure call +okay and that procedure is an example of + + align:start position:0% +okay and that procedure is an example of + + + align:start position:0% +okay and that procedure is an example of +something called a stub because what it + + align:start position:0% +something called a stub because what it + + + align:start position:0% +something called a stub because what it +is is a stub that to this caller fakes + + align:start position:0% +is is a stub that to this caller fakes + + + align:start position:0% +is is a stub that to this caller fakes +out the fact that there's a service + + align:start position:0% +out the fact that there's a service + + + align:start position:0% +out the fact that there's a service +somewhere else I mean it doesn't it it + + align:start position:0% +somewhere else I mean it doesn't it it + + + align:start position:0% +somewhere else I mean it doesn't it it +prevents the caller from having to deal + + align:start position:0% +prevents the caller from having to deal + + + align:start position:0% +prevents the caller from having to deal +with taking the arguments and putting it + + align:start position:0% +with taking the arguments and putting it + + + align:start position:0% +with taking the arguments and putting it +in a message and sending it to the other + + align:start position:0% +in a message and sending it to the other + + + align:start position:0% +in a message and sending it to the other +side um the caller just calls a Lo + + align:start position:0% +side um the caller just calls a Lo + + + align:start position:0% +side um the caller just calls a Lo +procedure um giving it suitable + + align:start position:0% +procedure um giving it suitable + + + align:start position:0% +procedure um giving it suitable +arguments that change for this function + + align:start position:0% +arguments that change for this function + + + align:start position:0% +arguments that change for this function +now to do the work of sending a message + + align:start position:0% +now to do the work of sending a message + + + align:start position:0% +now to do the work of sending a message +across the network but this is a local + + align:start position:0% +across the network but this is a local + + + align:start position:0% +across the network but this is a local +call so what happens underneath + + align:start position:0% +call so what happens underneath + + + align:start position:0% +call so what happens underneath +underneath in the library once you call + + align:start position:0% +underneath in the library once you call + + + align:start position:0% +underneath in the library once you call +exml RPC do execute in this example + + align:start position:0% +exml RPC do execute in this example + + + align:start position:0% +exml RPC do execute in this example +somebody does the work that Library does + + align:start position:0% +somebody does the work that Library does + + + align:start position:0% +somebody does the work that Library does +the work of taking the different + + align:start position:0% +the work of taking the different + + + align:start position:0% +the work of taking the different +arguments that have been presented to it + + align:start position:0% +arguments that have been presented to it + + + align:start position:0% +arguments that have been presented to it +and converting them into a message + + align:start position:0% +and converting them into a message + + + align:start position:0% +and converting them into a message +marshalling all of the stuff into a + + align:start position:0% +marshalling all of the stuff into a + + + align:start position:0% +marshalling all of the stuff into a +message and then shipping that message + + align:start position:0% +message and then shipping that message + + + align:start position:0% +message and then shipping that message +off to the server and that has to go + + align:start position:0% +off to the server and that has to go + + + align:start position:0% +off to the server and that has to go +into some kind of a format on the wire + + align:start position:0% +into some kind of a format on the wire + + + align:start position:0% +into some kind of a format on the wire +right ultimately on this wire connecting + + align:start position:0% +right ultimately on this wire connecting + + + align:start position:0% +right ultimately on this wire connecting +the client to the service there's format + + align:start position:0% +the client to the service there's format + + + align:start position:0% +the client to the service there's format +and I already mentioned that this runs + + align:start position:0% +and I already mentioned that this runs + + + align:start position:0% +and I already mentioned that this runs +on top of HTTP and so we can actually + + align:start position:0% +on top of HTTP and so we can actually + + + align:start position:0% +on top of HTTP and so we can actually +look at um what that looks + + align:start position:0% + + + + align:start position:0% + +like all + + align:start position:0% + + + + align:start position:0% + +right okay so post here is the method + + align:start position:0% +right okay so post here is the method + + + align:start position:0% +right okay so post here is the method +that you use in HTTP um the SL rpc2 is + + align:start position:0% +that you use in HTTP um the SL rpc2 is + + + align:start position:0% +that you use in HTTP um the SL rpc2 is +actually the same thing that was used in + + align:start position:0% +actually the same thing that was used in + + + align:start position:0% +actually the same thing that was used in +if you remember the previous uh uh from + + align:start position:0% +if you remember the previous uh uh from + + + align:start position:0% +if you remember the previous uh uh from +the previous screenshot um when we did + + align:start position:0% +the previous screenshot um when we did + + + align:start position:0% +the previous screenshot um when we did +the new to when we did the new call to + + align:start position:0% +the new to when we did the new call to + + + align:start position:0% +the new to when we did the new call to +get a new XML RPC client we gave it a + + align:start position:0% +get a new XML RPC client we gave it a + + + align:start position:0% +get a new XML RPC client we gave it a +server name and a port number but we + + align:start position:0% +server name and a port number but we + + + align:start position:0% +server name and a port number but we +also gave it something called rpc2 now + + align:start position:0% +also gave it something called rpc2 now + + + align:start position:0% +also gave it something called rpc2 now +that's just like a file on the other + + align:start position:0% +that's just like a file on the other + + + align:start position:0% +that's just like a file on the other +side it says there are many different + + align:start position:0% +side it says there are many different + + + align:start position:0% +side it says there are many different +RPC programs running on your service and + + align:start position:0% +RPC programs running on your service and + + + align:start position:0% +RPC programs running on your service and +I want rpc2 to run I mean I could have + + align:start position:0% +I want rpc2 to run I mean I could have + + + align:start position:0% +I want rpc2 to run I mean I could have +named it anything um I + + align:start position:0% +named it anything um I + + + align:start position:0% +named it anything um I +wanted and you know that's a lot like + + align:start position:0% +wanted and you know that's a lot like + + + align:start position:0% +wanted and you know that's a lot like +giving the file name on a URL and then + + align:start position:0% +giving the file name on a URL and then + + + align:start position:0% +giving the file name on a URL and then +you uh go on you give it the host name + + align:start position:0% +you uh go on you give it the host name + + + align:start position:0% +you uh go on you give it the host name +this is a lot like an HTTP header the + + align:start position:0% +this is a lot like an HTTP header the + + + align:start position:0% +this is a lot like an HTTP header the +interesting new stuff here is um in the + + align:start position:0% +interesting new stuff here is um in the + + + align:start position:0% +interesting new stuff here is um in the +XML Arguments for those who are not + + align:start position:0% +XML Arguments for those who are not + + + align:start position:0% +XML Arguments for those who are not +familiar with XML you know it's just a + + align:start position:0% +familiar with XML you know it's just a + + + align:start position:0% +familiar with XML you know it's just a +method of send a way of sending things + + align:start position:0% +method of send a way of sending things + + + align:start position:0% +method of send a way of sending things +that have attributes and values + + align:start position:0% +that have attributes and values + + + align:start position:0% +that have attributes and values +associated with them so every message + + align:start position:0% +associated with them so every message + + + align:start position:0% +associated with them so every message +has is in the has the format that it's + + align:start position:0% +has is in the has the format that it's + + + align:start position:0% +has is in the has the format that it's +attributes and values and they can be + + align:start position:0% +attributes and values and they can be + + + align:start position:0% +attributes and values and they can be +nested within each other um the only + + align:start position:0% +nested within each other um the only + + + align:start position:0% +nested within each other um the only +interesting thing is here U this + + align:start position:0% +interesting thing is here U this + + + align:start position:0% +interesting thing is here U this +particular XML RPC system supports a few + + align:start position:0% +particular XML RPC system supports a few + + + align:start position:0% +particular XML RPC system supports a few +different data formats you can do + + align:start position:0% +different data formats you can do + + + align:start position:0% +different data formats you can do +integers and you characters and strings + + align:start position:0% +integers and you characters and strings + + + align:start position:0% +integers and you characters and strings +and doubles and floats and a few + + align:start position:0% +and doubles and floats and a few + + + align:start position:0% +and doubles and floats and a few +different things like that and I4 just + + align:start position:0% +different things like that and I4 just + + + align:start position:0% +different things like that and I4 just +means it's a 32-bit integer and you can + + align:start position:0% +means it's a 32-bit integer and you can + + + align:start position:0% +means it's a 32-bit integer and you can +give it you know three numbers the from + + align:start position:0% +give it you know three numbers the from + + + align:start position:0% +give it you know three numbers the from +your account number the you know your + + align:start position:0% +your account number the you know your + + + align:start position:0% +your account number the you know your +supplier's account number and the amount + + align:start position:0% +supplier's account number and the amount + + + align:start position:0% +supplier's account number and the amount +of money that you want to + + align:start position:0% +of money that you want to + + + align:start position:0% +of money that you want to +transfer the good thing is all of this + + align:start position:0% +transfer the good thing is all of this + + + align:start position:0% +transfer the good thing is all of this +stuff is done underneath the covers and + + align:start position:0% +stuff is done underneath the covers and + + + align:start position:0% +stuff is done underneath the covers and +you don't actually have to deal with it + + align:start position:0% +you don't actually have to deal with it + + + align:start position:0% +you don't actually have to deal with it +if you're writing the client or you're + + align:start position:0% +if you're writing the client or you're + + + align:start position:0% +if you're writing the client or you're +writing the service all this work + + align:start position:0% +writing the service all this work + + + align:start position:0% +writing the service all this work +happens underneath so it greatly + + align:start position:0% +happens underneath so it greatly + + + align:start position:0% +happens underneath so it greatly +simplifies uh your ability to take um + + align:start position:0% +simplifies uh your ability to take um + + + align:start position:0% +simplifies uh your ability to take um +you know Implement client service + + align:start position:0% +you know Implement client service + + + align:start position:0% +you know Implement client service +programs with clients Services being + + align:start position:0% +programs with clients Services being + + + align:start position:0% +programs with clients Services being +separated from one + + align:start position:0% + + + + align:start position:0% + +another + + align:start position:0% +another + + + align:start position:0% +another +okay so so far we've made it look a lot + + align:start position:0% +okay so so far we've made it look a lot + + + align:start position:0% +okay so so far we've made it look a lot +except for this little timer that you + + align:start position:0% +except for this little timer that you + + + align:start position:0% +except for this little timer that you +have to maintain um we made look a lot + + align:start position:0% +have to maintain um we made look a lot + + + align:start position:0% +have to maintain um we made look a lot +like a remote procedure call is like a + + align:start position:0% +like a remote procedure call is like a + + + align:start position:0% +like a remote procedure call is like a +procedure problem in fact the code here + + align:start position:0% +procedure problem in fact the code here + + + align:start position:0% +procedure problem in fact the code here +I mean the only difference was we + + align:start position:0% +I mean the only difference was we + + + align:start position:0% +I mean the only difference was we +replace what was previously what would + + align:start position:0% +replace what was previously what would + + + align:start position:0% +replace what was previously what would +have been money transferred with + + align:start position:0% +have been money transferred with + + + align:start position:0% +have been money transferred with +argument we replaced with a stub call + + align:start position:0% +argument we replaced with a stub call + + + align:start position:0% +argument we replaced with a stub call +taking the name of the procedure we want + + align:start position:0% +taking the name of the procedure we want + + + align:start position:0% +taking the name of the procedure we want +to run on the service with the so it + + align:start position:0% +to run on the service with the so it + + + align:start position:0% +to run on the service with the so it +looks a lot like a + + align:start position:0% +looks a lot like a + + + align:start position:0% +looks a lot like a +procedure that actually is a pretty + + align:start position:0% +procedure that actually is a pretty + + + align:start position:0% +procedure that actually is a pretty +deceptive thing and in fact a hint at + + align:start position:0% +deceptive thing and in fact a hint at + + + align:start position:0% +deceptive thing and in fact a hint at +that is you can get from the fact that + + align:start position:0% +that is you can get from the fact that + + + align:start position:0% +that is you can get from the fact that +at the bottom of this thing up there um + + align:start position:0% +at the bottom of this thing up there um + + + align:start position:0% +at the bottom of this thing up there um +there are there's a line that says you + + align:start position:0% +there are there's a line that says you + + + align:start position:0% +there are there's a line that says you +have to deal with xmlrpc exception and + + align:start position:0% +have to deal with xmlrpc exception and + + + align:start position:0% +have to deal with xmlrpc exception and +that's the kind of exception you get + + align:start position:0% +that's the kind of exception you get + + + align:start position:0% +that's the kind of exception you get +when the underlying RPC Library decides + + align:start position:0% +when the underlying RPC Library decides + + + align:start position:0% +when the underlying RPC Library decides +that it hasn't heard an answer from the + + align:start position:0% +that it hasn't heard an answer from the + + + align:start position:0% +that it hasn't heard an answer from the +service in a while and throws an + + align:start position:0% +service in a while and throws an + + + align:start position:0% +service in a while and throws an +exception and your code has to deal with + + align:start position:0% +exception and your code has to deal with + + + align:start position:0% +exception and your code has to deal with +it now you're never going to get that + + align:start position:0% +it now you're never going to get that + + + align:start position:0% +it now you're never going to get that +kind of exception from a regular + + align:start position:0% +kind of exception from a regular + + + align:start position:0% +kind of exception from a regular +procedure it's not going to say I didn't + + align:start position:0% +procedure it's not going to say I didn't + + + align:start position:0% +procedure it's not going to say I didn't +hear back from the caller from the + + align:start position:0% +hear back from the caller from the + + + align:start position:0% +hear back from the caller from the +colleag do something see that's a + + align:start position:0% +colleag do something see that's a + + + align:start position:0% +colleag do something see that's a +different that's that's a new mode a new + + align:start position:0% +different that's that's a new mode a new + + + align:start position:0% +different that's that's a new mode a new +exception mode that you didn't + + align:start position:0% +exception mode that you didn't + + + align:start position:0% +exception mode that you didn't +previously have to deal with I mean you + + align:start position:0% +previously have to deal with I mean you + + + align:start position:0% +previously have to deal with I mean you +have to deal with other kinds of + + align:start position:0% +have to deal with other kinds of + + + align:start position:0% +have to deal with other kinds of +exceptions but not this + + align:start position:0% +exceptions but not this + + + align:start position:0% +exceptions but not this +one so an RPC is notal is not the same + + align:start position:0% +one so an RPC is notal is not the same + + + align:start position:0% +one so an RPC is notal is not the same +as a procedure call and in fact it's a + + align:start position:0% +as a procedure call and in fact it's a + + + align:start position:0% +as a procedure call and in fact it's a +little unfortunate + + align:start position:0% +little unfortunate + + + align:start position:0% +little unfortunate +that um in most historical reasons uh + + align:start position:0% +that um in most historical reasons uh + + + align:start position:0% +that um in most historical reasons uh +we're stuck a little bit with the name + + align:start position:0% +we're stuck a little bit with the name + + + align:start position:0% +we're stuck a little bit with the name +mode procedure call in fact increasingly + + align:start position:0% +mode procedure call in fact increasingly + + + align:start position:0% +mode procedure call in fact increasingly +more and more RPC systems um don't look + + align:start position:0% +more and more RPC systems um don't look + + + align:start position:0% +more and more RPC systems um don't look +like procedure calls at all in terms of + + align:start position:0% +like procedure calls at all in terms of + + + align:start position:0% +like procedure calls at all in terms of +the semantics um but we're sort of stuck + + align:start position:0% +the semantics um but we're sort of stuck + + + align:start position:0% +the semantics um but we're sort of stuck +with the name and people continue to + + align:start position:0% +with the name and people continue to + + + align:start position:0% +with the name and people continue to +have um you know kinds of remote + + align:start position:0% +have um you know kinds of remote + + + align:start position:0% +have um you know kinds of remote +procedure calls and they use the same + + align:start position:0% +procedure calls and they use the same + + + align:start position:0% +procedure calls and they use the same +name for + + align:start position:0% +name for + + + align:start position:0% +name for +it and the first main difference arises + + align:start position:0% +it and the first main difference arises + + + align:start position:0% +it and the first main difference arises +from the fact + + align:start position:0% +from the fact + + + align:start position:0% +from the fact +that there is no fate sharing between + + align:start position:0% +that there is no fate sharing between + + + align:start position:0% +that there is no fate sharing between +client and service it's the service + + align:start position:0% +client and service it's the service + + + align:start position:0% +client and service it's the service +crashes the client doesn't cck already + + align:start position:0% +crashes the client doesn't cck already + + + align:start position:0% +crashes the client doesn't cck already +you have a big difference between um a + + align:start position:0% +you have a big difference between um a + + + align:start position:0% +you have a big difference between um a +regular procedure and previously I + + align:start position:0% +regular procedure and previously I + + + align:start position:0% +regular procedure and previously I +presented this as a an advantage because + + align:start position:0% +presented this as a an advantage because + + + align:start position:0% +presented this as a an advantage because +you know if you have faith sharing then + + align:start position:0% +you know if you have faith sharing then + + + align:start position:0% +you know if you have faith sharing then +the color is always at the mercy of the + + align:start position:0% +the color is always at the mercy of the + + + align:start position:0% +the color is always at the mercy of the +colleague but because you have no faith + + align:start position:0% +colleague but because you have no faith + + + align:start position:0% +colleague but because you have no faith +sharing you have other problems um to + + align:start position:0% +sharing you have other problems um to + + + align:start position:0% +sharing you have other problems um to +deal with and in particular all of these + + align:start position:0% +deal with and in particular all of these + + + align:start position:0% +deal with and in particular all of these +stem from the fact that it's extremely + + align:start position:0% +stem from the fact that it's extremely + + + align:start position:0% +stem from the fact that it's extremely +hard to distinguish between a failure + + align:start position:0% +hard to distinguish between a failure + + + align:start position:0% +hard to distinguish between a failure +versus extremely slow + + align:start position:0% + + + + align:start position:0% + +and it will turn out that we'll revisit + + align:start position:0% +and it will turn out that we'll revisit + + + align:start position:0% +and it will turn out that we'll revisit +this over and over again we talk when we + + align:start position:0% +this over and over again we talk when we + + + align:start position:0% +this over and over again we talk when we +talk about networks um and reliable + + align:start position:0% +talk about networks um and reliable + + + align:start position:0% +talk about networks um and reliable +transmission over networks we'll deal + + align:start position:0% +transmission over networks we'll deal + + + align:start position:0% +transmission over networks we'll deal +with it and then we're going to talk + + align:start position:0% +with it and then we're going to talk + + + align:start position:0% +with it and then we're going to talk +about fall tolerance um and we're going + + align:start position:0% +about fall tolerance um and we're going + + + align:start position:0% +about fall tolerance um and we're going +to talk about an idea called atomicity + + align:start position:0% +to talk about an idea called atomicity + + + align:start position:0% +to talk about an idea called atomicity +and then we're going to talk about + + align:start position:0% +and then we're going to talk about + + + align:start position:0% +and then we're going to talk about +something called transactions and + + align:start position:0% +something called transactions and + + + align:start position:0% +something called transactions and +they're all going to deal with this + + align:start position:0% +they're all going to deal with this + + + align:start position:0% +they're all going to deal with this +problem that it's going to be very hard + + align:start position:0% +problem that it's going to be very hard + + + align:start position:0% +problem that it's going to be very hard +for us to tell when you ask somebody to + + align:start position:0% +for us to tell when you ask somebody to + + + align:start position:0% +for us to tell when you ask somebody to +do a piece of work whether they did it + + align:start position:0% +do a piece of work whether they did it + + + align:start position:0% +do a piece of work whether they did it +fully or did not okay and this is going + + align:start position:0% +fully or did not okay and this is going + + + align:start position:0% +fully or did not okay and this is going +to be a repeated theme a theme that + + align:start position:0% +to be a repeated theme a theme that + + + align:start position:0% +to be a repeated theme a theme that +going to repeatedly see in in the course + + align:start position:0% +going to repeatedly see in in the course + + + align:start position:0% +going to repeatedly see in in the course +but to complicate why this is hard uh + + align:start position:0% +but to complicate why this is hard uh + + + align:start position:0% +but to complicate why this is hard uh +let me explain three possible things + + align:start position:0% +let me explain three possible things + + + align:start position:0% +let me explain three possible things +that could happen when you have a client + + align:start position:0% +that could happen when you have a client + + + align:start position:0% +that could happen when you have a client +talk to a service and um what kind of + + align:start position:0% +talk to a service and um what kind of + + + align:start position:0% +talk to a service and um what kind of +semantics you want from a client service + + align:start position:0% +semantics you want from a client service + + + align:start position:0% +semantics you want from a client service +interaction they all stem from the fact + + align:start position:0% +interaction they all stem from the fact + + + align:start position:0% +interaction they all stem from the fact +that this is extremely hard to + + align:start position:0% +that this is extremely hard to + + + align:start position:0% +that this is extremely hard to +determine the first semantics that you + + align:start position:0% +determine the first semantics that you + + + align:start position:0% +determine the first semantics that you +might want is the ideal sems the client + + align:start position:0% +might want is the ideal sems the client + + + align:start position:0% +might want is the ideal sems the client +talks to the service and either the + + align:start position:0% +talks to the service and either the + + + align:start position:0% +talks to the service and either the +service answers with a response or it + + align:start position:0% +service answers with a response or it + + + align:start position:0% +service answers with a response or it +doesn't okay and that's something called + + align:start position:0% +doesn't okay and that's something called + + + align:start position:0% +doesn't okay and that's something called +exactly once + + align:start position:0% + + + + align:start position:0% + +semantics so in this example here + + align:start position:0% +semantics so in this example here + + + align:start position:0% +semantics so in this example here +underneath the library May time out and + + align:start position:0% +underneath the library May time out and + + + align:start position:0% +underneath the library May time out and +it may wish to retransmit or it may wish + + align:start position:0% +it may wish to retransmit or it may wish + + + align:start position:0% +it may wish to retransmit or it may wish +to throw an exception and the caller + + align:start position:0% +to throw an exception and the caller + + + align:start position:0% +to throw an exception and the caller +caller may you know the client may want + + align:start position:0% +caller may you know the client may want + + + align:start position:0% +caller may you know the client may want +to send the request again but in ideal + + align:start position:0% +to send the request again but in ideal + + + align:start position:0% +to send the request again but in ideal +hits you want one time you want exactly + + align:start position:0% +hits you want one time you want exactly + + + align:start position:0% +hits you want one time you want exactly +once this amount of money to be moved + + align:start position:0% +once this amount of money to be moved + + + align:start position:0% +once this amount of money to be moved +from Bank account one to bank account + + align:start position:0% +from Bank account one to bank account + + + align:start position:0% +from Bank account one to bank account +two right you certainly don't want you + + align:start position:0% +two right you certainly don't want you + + + align:start position:0% +two right you certainly don't want you +know your amount of money to be moved + + align:start position:0% +know your amount of money to be moved + + + align:start position:0% +know your amount of money to be moved +twice to your + + align:start position:0% +twice to your + + + align:start position:0% +twice to your +supplier it will turn out this is ideal + + align:start position:0% +supplier it will turn out this is ideal + + + align:start position:0% +supplier it will turn out this is ideal +and it's going to be you know pretty + + align:start position:0% +and it's going to be you know pretty + + + align:start position:0% +and it's going to be you know pretty +difficult and extremely hard to to um + + align:start position:0% +difficult and extremely hard to to um + + + align:start position:0% +difficult and extremely hard to to um +achieve exactly once the mandat and + + align:start position:0% +achieve exactly once the mandat and + + + align:start position:0% +achieve exactly once the mandat and +we're going to try hard to different + + align:start position:0% +we're going to try hard to different + + + align:start position:0% +we're going to try hard to different +methods in the course but this it's not + + align:start position:0% +methods in the course but this it's not + + + align:start position:0% +methods in the course but this it's not +an easy problem at all it stems from the + + align:start position:0% +an easy problem at all it stems from the + + + align:start position:0% +an easy problem at all it stems from the +fact that it's very hard to know + + align:start position:0% +fact that it's very hard to know + + + align:start position:0% +fact that it's very hard to know +that so we might give up a little bit + + align:start position:0% +that so we might give up a little bit + + + align:start position:0% +that so we might give up a little bit +and say okay I don't I can't really get + + align:start position:0% +and say okay I don't I can't really get + + + align:start position:0% +and say okay I don't I can't really get +exactly once sematics very easily but + + align:start position:0% +exactly once sematics very easily but + + + align:start position:0% +exactly once sematics very easily but +let me try for at least + + align:start position:0% + + + + align:start position:0% + +once so what this means is that I will + + align:start position:0% +once so what this means is that I will + + + align:start position:0% +once so what this means is that I will +keep the client will keep retrying or + + align:start position:0% +keep the client will keep retrying or + + + align:start position:0% +keep the client will keep retrying or +the library will keep retrying and you + + align:start position:0% +the library will keep retrying and you + + + align:start position:0% +the library will keep retrying and you +can decompose it in either way until it + + align:start position:0% +can decompose it in either way until it + + + align:start position:0% +can decompose it in either way until it +is sure that the that this call + + align:start position:0% +is sure that the that this call + + + align:start position:0% +is sure that the that this call +succeeded at least once now it might + + align:start position:0% +succeeded at least once now it might + + + align:start position:0% +succeeded at least once now it might +have succeeded more than once you know + + align:start position:0% +have succeeded more than once you know + + + align:start position:0% +have succeeded more than once you know +the service you know was very slow and + + align:start position:0% +the service you know was very slow and + + + align:start position:0% +the service you know was very slow and +then it times out you try it again the + + align:start position:0% +then it times out you try it again the + + + align:start position:0% +then it times out you try it again the +service says oh okay I see a request I + + align:start position:0% +service says oh okay I see a request I + + + align:start position:0% +service says oh okay I see a request I +do it again but it's at least once + + align:start position:0% +do it again but it's at least once + + + align:start position:0% +do it again but it's at least once +okay now at least once is not nice + + align:start position:0% +okay now at least once is not nice + + + align:start position:0% +okay now at least once is not nice +semantics if you're using at least one + + align:start position:0% +semantics if you're using at least one + + + align:start position:0% +semantics if you're using at least one +semantics in your code here right + + align:start position:0% +semantics in your code here right + + + align:start position:0% +semantics in your code here right +because I mean your supplier might end + + align:start position:0% +because I mean your supplier might end + + + align:start position:0% +because I mean your supplier might end +up with $7 million instead of $1 million + + align:start position:0% +up with $7 million instead of $1 million + + + align:start position:0% +up with $7 million instead of $1 million +but at least once is okay if the service + + align:start position:0% +but at least once is okay if the service + + + align:start position:0% +but at least once is okay if the service +has a certain kind of semantic called + + align:start position:0% +has a certain kind of semantic called + + + align:start position:0% +has a certain kind of semantic called +item Port + + align:start position:0% + + + + align:start position:0% + +semantics what that means is that when + + align:start position:0% +semantics what that means is that when + + + align:start position:0% +semantics what that means is that when +you do an operation more than once the + + align:start position:0% +you do an operation more than once the + + + align:start position:0% +you do an operation more than once the +answers are the same as if you really + + align:start position:0% +answers are the same as if you really + + + align:start position:0% +answers are the same as if you really +want as a simple example if this wasn't + + align:start position:0% +want as a simple example if this wasn't + + + align:start position:0% +want as a simple example if this wasn't +a transfer of money but just you + + align:start position:0% +a transfer of money but just you + + + align:start position:0% +a transfer of money but just you +checking your bank account balance it + + align:start position:0% +checking your bank account balance it + + + align:start position:0% +checking your bank account balance it +doesn't really matter that you do it 100 + + align:start position:0% +doesn't really matter that you do it 100 + + + align:start position:0% +doesn't really matter that you do it 100 +times as long as one of them succeeds + + align:start position:0% +times as long as one of them succeeds + + + align:start position:0% +times as long as one of them succeeds +and you get back balance you're fine I + + align:start position:0% +and you get back balance you're fine I + + + align:start position:0% +and you get back balance you're fine I +mean doing it seven times does not + + align:start position:0% +mean doing it seven times does not + + + align:start position:0% +mean doing it seven times does not +really change anything does not move + + align:start position:0% +really change anything does not move + + + align:start position:0% +really change anything does not move +extra money anywhere else um you know so + + align:start position:0% +extra money anywhere else um you know so + + + align:start position:0% +extra money anywhere else um you know so +that's an example of an item poent um + + align:start position:0% +that's an example of an item poent um + + + align:start position:0% +that's an example of an item poent um +action + + align:start position:0% +action + + + align:start position:0% +action +which um you know works out well with at + + align:start position:0% +which um you know works out well with at + + + align:start position:0% +which um you know works out well with at +least one semantics and at least one + + align:start position:0% +least one semantics and at least one + + + align:start position:0% +least one semantics and at least one +semantics is much easier to obtain than + + align:start position:0% +semantics is much easier to obtain than + + + align:start position:0% +semantics is much easier to obtain than +exactly once semantics + + align:start position:0% +exactly once semantics + + + align:start position:0% +exactly once semantics +and the Third Kind of semantics U is + + align:start position:0% +and the Third Kind of semantics U is + + + align:start position:0% +and the Third Kind of semantics U is +something which you know coners or at + + align:start position:0% +something which you know coners or at + + + align:start position:0% +something which you know coners or at +most wants + + align:start position:0% +most wants + + + align:start position:0% +most wants +semantics that means zero or more + + align:start position:0% + + + + align:start position:0% + +times and here the challenge is really + + align:start position:0% +times and here the challenge is really + + + align:start position:0% +times and here the challenge is really +figuring out did it really work at least + + align:start position:0% +figuring out did it really work at least + + + align:start position:0% +figuring out did it really work at least +once or not did it work exactly I mean + + align:start position:0% +once or not did it work exactly I mean + + + align:start position:0% +once or not did it work exactly I mean +at most once or not so if you don't get + + align:start position:0% +at most once or not so if you don't get + + + align:start position:0% +at most once or not so if you don't get +a response back then um you know you + + align:start position:0% +a response back then um you know you + + + align:start position:0% +a response back then um you know you +time out and it might be that it didn't + + align:start position:0% +time out and it might be that it didn't + + + align:start position:0% +time out and it might be that it didn't +succeed at all and you say that's fine + + align:start position:0% +succeed at all and you say that's fine + + + align:start position:0% +succeed at all and you say that's fine +I'll deal with it um separately and if + + align:start position:0% +I'll deal with it um separately and if + + + align:start position:0% +I'll deal with it um separately and if +you get a response back then you know + + align:start position:0% +you get a response back then you know + + + align:start position:0% +you get a response back then you know +that it worked it turns out even that is + + align:start position:0% +that it worked it turns out even that is + + + align:start position:0% +that it worked it turns out even that is +going to be a little bit tricky to + + align:start position:0% +going to be a little bit tricky to + + + align:start position:0% +going to be a little bit tricky to +implement but these are the kinds of + + align:start position:0% +implement but these are the kinds of + + + align:start position:0% +implement but these are the kinds of +schematics you could get you could + + align:start position:0% +schematics you could get you could + + + align:start position:0% +schematics you could get you could +expect from your RPC + + align:start position:0% +expect from your RPC + + + align:start position:0% +expect from your RPC +system now actually to first order most + + align:start position:0% +system now actually to first order most + + + align:start position:0% +system now actually to first order most +RPC systems like XML RPC don't really + + align:start position:0% +RPC systems like XML RPC don't really + + + align:start position:0% +RPC systems like XML RPC don't really +deal with any of this in a particular + + align:start position:0% +deal with any of this in a particular + + + align:start position:0% +deal with any of this in a particular +They Don't Really provide any well- + + align:start position:0% +They Don't Really provide any well- + + + align:start position:0% +They Don't Really provide any well- +defined semantics it's usually for the + + align:start position:0% +defined semantics it's usually for the + + + align:start position:0% +defined semantics it's usually for the +clients sitting on top and the services + + align:start position:0% +clients sitting on top and the services + + + align:start position:0% +clients sitting on top and the services +to determine what kind of semantics they + + align:start position:0% +to determine what kind of semantics they + + + align:start position:0% +to determine what kind of semantics they +need and Implement that um at a at a + + align:start position:0% +need and Implement that um at a at a + + + align:start position:0% +need and Implement that um at a at a +higher layer at least with most of these + + align:start position:0% +higher layer at least with most of these + + + align:start position:0% +higher layer at least with most of these +standard protocols but but many of them + + align:start position:0% +standard protocols but but many of them + + + align:start position:0% +standard protocols but but many of them +are well equipped to deal with at least + + align:start position:0% +are well equipped to deal with at least + + + align:start position:0% +are well equipped to deal with at least +once + + align:start position:0% +once + + + align:start position:0% +once +um and you know through the course we'll + + align:start position:0% +um and you know through the course we'll + + + align:start position:0% +um and you know through the course we'll +see me different ways in which we'll + + align:start position:0% +see me different ways in which we'll + + + align:start position:0% +see me different ways in which we'll +accomplish um these different goals + + align:start position:0% +accomplish um these different goals + + + align:start position:0% +accomplish um these different goals +these different schematics that we want + + align:start position:0% +these different schematics that we want + + + align:start position:0% +these different schematics that we want +from our RPC like system from from our + + align:start position:0% +from our RPC like system from from our + + + align:start position:0% +from our RPC like system from from our +different RPC + + align:start position:0% + + + + align:start position:0% + +systems now there's another difference + + align:start position:0% +systems now there's another difference + + + align:start position:0% +systems now there's another difference +between regular procedure calls and um + + align:start position:0% +between regular procedure calls and um + + + align:start position:0% +between regular procedure calls and um +remote procedure calls or more generally + + align:start position:0% +remote procedure calls or more generally + + + align:start position:0% +remote procedure calls or more generally +from client service + + align:start position:0% +from client service + + + align:start position:0% +from client service +computer remember um in the uh second + + align:start position:0% +computer remember um in the uh second + + + align:start position:0% +computer remember um in the uh second +lecture I told you that you know you can + + align:start position:0% +lecture I told you that you know you can + + + align:start position:0% +lecture I told you that you know you can +always get more band with and you can + + align:start position:0% +always get more band with and you can + + + align:start position:0% +always get more band with and you can +always get more processing than to law + + align:start position:0% +always get more processing than to law + + + align:start position:0% +always get more processing than to law +but one thing you can't actually change + + align:start position:0% +but one thing you can't actually change + + + align:start position:0% +but one thing you can't actually change +is the latency between two computers + + align:start position:0% +is the latency between two computers + + + align:start position:0% +is the latency between two computers +connected by a wi connected by a network + + align:start position:0% +connected by a wi connected by a network + + + align:start position:0% +connected by a wi connected by a network +and the speed of light isn't + + align:start position:0% +and the speed of light isn't + + + align:start position:0% +and the speed of light isn't +changing what that means is that with + + align:start position:0% +changing what that means is that with + + + align:start position:0% +changing what that means is that with +time the number of instructions that you + + align:start position:0% +time the number of instructions that you + + + align:start position:0% +time the number of instructions that you +can run when you have a computer two + + align:start position:0% +can run when you have a computer two + + + align:start position:0% +can run when you have a computer two +computers separated by a wire there's a + + align:start position:0% +computers separated by a wire there's a + + + align:start position:0% +computers separated by a wire there's a +certain delay between them no matter + + align:start position:0% +certain delay between them no matter + + + align:start position:0% +certain delay between them no matter +what you do so there's a certain delay + + align:start position:0% +what you do so there's a certain delay + + + align:start position:0% +what you do so there's a certain delay +to do a procedure call that's a remote + + align:start position:0% +to do a procedure call that's a remote + + + align:start position:0% +to do a procedure call that's a remote +procedure call you know take certain + + align:start position:0% +procedure call you know take certain + + + align:start position:0% +procedure call you know take certain +delay to send a message and to get a + + align:start position:0% +delay to send a message and to get a + + + align:start position:0% +delay to send a message and to get a +response back even as computers get + + align:start position:0% +response back even as computers get + + + align:start position:0% +response back even as computers get +faster and faster and faster that + + align:start position:0% +faster and faster and faster that + + + align:start position:0% +faster and faster and faster that +changing at all but the problem is that + + align:start position:0% +changing at all but the problem is that + + + align:start position:0% +changing at all but the problem is that +the number of instructions you can run + + align:start position:0% +the number of instructions you can run + + + align:start position:0% +the number of instructions you can run +within that duration is increasing with + + align:start position:0% +within that duration is increasing with + + + align:start position:0% +within that duration is increasing with +time because it's a fixed amount of time + + align:start position:0% +time because it's a fixed amount of time + + + align:start position:0% +time because it's a fixed amount of time +and the number of instructions you could + + align:start position:0% +and the number of instructions you could + + + align:start position:0% +and the number of instructions you could +run locally on a computer uh increases + + align:start position:0% +run locally on a computer uh increases + + + align:start position:0% +run locally on a computer uh increases +um with + + align:start position:0% +um with + + + align:start position:0% +um with +time so that has led people to be more + + align:start position:0% +time so that has led people to be more + + + align:start position:0% +time so that has led people to be more +aggressive about what they do in a + + align:start position:0% +aggressive about what they do in a + + + align:start position:0% +aggressive about what they do in a +remote procedure call what people have + + align:start position:0% +remote procedure call what people have + + + align:start position:0% +remote procedure call what people have +said is wait it doesn't make sense for + + align:start position:0% +said is wait it doesn't make sense for + + + align:start position:0% +said is wait it doesn't make sense for +me me to for a client to issue a + + align:start position:0% +me me to for a client to issue a + + + align:start position:0% +me me to for a client to issue a +procedure call invocation to a service + + align:start position:0% +procedure call invocation to a service + + + align:start position:0% +procedure call invocation to a service +and then just sit and wait like in a + + align:start position:0% +and then just sit and wait like in a + + + align:start position:0% +and then just sit and wait like in a +regular procedure call the answer I mean + + align:start position:0% +regular procedure call the answer I mean + + + align:start position:0% +regular procedure call the answer I mean +you know I'm just sitting there tring my + + align:start position:0% +you know I'm just sitting there tring my + + + align:start position:0% +you know I'm just sitting there tring my +thumbs and this thing is you know gone + + align:start position:0% +thumbs and this thing is you know gone + + + align:start position:0% +thumbs and this thing is you know gone +away and you know I'm waiting for it to + + align:start position:0% +away and you know I'm waiting for it to + + + align:start position:0% +away and you know I'm waiting for it to +respond I could be doing + + align:start position:0% +respond I could be doing + + + align:start position:0% +respond I could be doing +work so that's LED people to changing + + align:start position:0% +work so that's LED people to changing + + + align:start position:0% +work so that's LED people to changing +the synchronous model + + align:start position:0% +the synchronous model + + + align:start position:0% +the synchronous model +of um of RPC of a procedure call + + align:start position:0% +of um of RPC of a procedure call + + + align:start position:0% +of um of RPC of a procedure call +interface to do thing called an + + align:start position:0% +interface to do thing called an + + + align:start position:0% +interface to do thing called an +asynchronous procedure call interface + + align:start position:0% +asynchronous procedure call interface + + + align:start position:0% +asynchronous procedure call interface +and all you know things like xmlrpc and + + align:start position:0% +and all you know things like xmlrpc and + + + align:start position:0% +and all you know things like xmlrpc and +its follow on the difference between + + align:start position:0% +its follow on the difference between + + + align:start position:0% +its follow on the difference between +soap and XML RPC is that um I can + + align:start position:0% +soap and XML RPC is that um I can + + + align:start position:0% +soap and XML RPC is that um I can +understand this and this Builds on xmlc + + align:start position:0% +understand this and this Builds on xmlc + + + align:start position:0% +understand this and this Builds on xmlc +and it seems like very few people + + align:start position:0% +and it seems like very few people + + + align:start position:0% +and it seems like very few people +understand so um I mean + + align:start position:0% +understand so um I mean + + + align:start position:0% +understand so um I mean +I um there's a lot of people who have + + align:start position:0% +I um there's a lot of people who have + + + align:start position:0% +I um there's a lot of people who have +given up on trying to understand the + + align:start position:0% +given up on trying to understand the + + + align:start position:0% +given up on trying to understand the +specification but XML RPC turns out to + + align:start position:0% +specification but XML RPC turns out to + + + align:start position:0% +specification but XML RPC turns out to +be a really simple seven or 10 page + + align:start position:0% +be a really simple seven or 10 page + + + align:start position:0% +be a really simple seven or 10 page +document that's very easy to understand + + align:start position:0% +document that's very easy to understand + + + align:start position:0% +document that's very easy to understand +a lot of people use it um but anyway all + + align:start position:0% +a lot of people use it um but anyway all + + + align:start position:0% +a lot of people use it um but anyway all +of these Systems Support air synchronous + + align:start position:0% +of these Systems Support air synchronous + + + align:start position:0% +of these Systems Support air synchronous +RP see the idea here is that the client + + align:start position:0% +RP see the idea here is that the client + + + align:start position:0% +RP see the idea here is that the client +sends call indicator remote request to + + align:start position:0% +sends call indicator remote request to + + + align:start position:0% +sends call indicator remote request to +the service and then it goes about doing + + align:start position:0% +the service and then it goes about doing + + + align:start position:0% +the service and then it goes about doing +its work when the service responds with + + align:start position:0% +its work when the service responds with + + + align:start position:0% +its work when the service responds with +an answer it responds with not just the + + align:start position:0% +an answer it responds with not just the + + + align:start position:0% +an answer it responds with not just the +answer but also something that tells the + + align:start position:0% +answer but also something that tells the + + + align:start position:0% +answer but also something that tells the +client which service request which + + align:start position:0% +client which service request which + + + align:start position:0% +client which service request which +procedure call request it's responding + + align:start position:0% +procedure call request it's responding + + + align:start position:0% +procedure call request it's responding +to and when that response comes back the + + align:start position:0% +to and when that response comes back the + + + align:start position:0% +to and when that response comes back the +client can handle + + align:start position:0% +client can handle + + + align:start position:0% +client can handle +it now the way in which you have to + + align:start position:0% +it now the way in which you have to + + + align:start position:0% +it now the way in which you have to +implement this or the way in which you + + align:start position:0% +implement this or the way in which you + + + align:start position:0% +implement this or the way in which you +have to design this is that associated + + align:start position:0% +have to design this is that associated + + + align:start position:0% +have to design this is that associated +with every procedure called request you + + align:start position:0% +with every procedure called request you + + + align:start position:0% +with every procedure called request you +also have to associate what's called + + align:start position:0% +also have to associate what's called + + + align:start position:0% +also have to associate what's called +called A Handler because you're going to + + align:start position:0% +called A Handler because you're going to + + + align:start position:0% +called A Handler because you're going to +issue this request to the service and + + align:start position:0% +issue this request to the service and + + + align:start position:0% +issue this request to the service and +then go about doing your work when the + + align:start position:0% +then go about doing your work when the + + + align:start position:0% +then go about doing your work when the +answer comes back the RPC Library + + align:start position:0% +answer comes back the RPC Library + + + align:start position:0% +answer comes back the RPC Library +underneath has to the communication + + align:start position:0% +underneath has to the communication + + + align:start position:0% +underneath has to the communication +library has to know who gets this answer + + align:start position:0% +library has to know who gets this answer + + + align:start position:0% +library has to know who gets this answer +because you might have issued many such + + align:start position:0% +because you might have issued many such + + + align:start position:0% +because you might have issued many such +service requests so who gets this answer + + align:start position:0% +service requests so who gets this answer + + + align:start position:0% +service requests so who gets this answer +so you associate with every request a + + align:start position:0% +so you associate with every request a + + + align:start position:0% +so you associate with every request a +call back a Handler which then is called + + align:start position:0% +call back a Handler which then is called + + + align:start position:0% +call back a Handler which then is called +back and that Handler runs dealing with + + align:start position:0% +back and that Handler runs dealing with + + + align:start position:0% +back and that Handler runs dealing with +the answer that comes from + + align:start position:0% +the answer that comes from + + + align:start position:0% +the answer that comes from +and so that actually allows you to be a + + align:start position:0% +and so that actually allows you to be a + + + align:start position:0% +and so that actually allows you to be a +little more decoupled than we were with + + align:start position:0% +little more decoupled than we were with + + + align:start position:0% +little more decoupled than we were with +remote procedure College even more + + align:start position:0% +remote procedure College even more + + + align:start position:0% +remote procedure College even more +decoupled The Client Services even more + + align:start position:0% +decoupled The Client Services even more + + + align:start position:0% +decoupled The Client Services even more +because the c is now no longer waiting + + align:start position:0% +because the c is now no longer waiting + + + align:start position:0% +because the c is now no longer waiting +for the service to turn an answer to + + align:start position:0% +for the service to turn an answer to + + + align:start position:0% +for the service to turn an answer to +it so that's the first way in which + + align:start position:0% +it so that's the first way in which + + + align:start position:0% +it so that's the first way in which +people have extended it the second way + + align:start position:0% +people have extended it the second way + + + align:start position:0% +people have extended it the second way +in which people have extended it is + + align:start position:0% +in which people have extended it is + + + align:start position:0% +in which people have extended it is +using this intermediary idea that we + + align:start position:0% +using this intermediary idea that we + + + align:start position:0% +using this intermediary idea that we +talked about before where the service is + + align:start position:0% +talked about before where the service is + + + align:start position:0% +talked about before where the service is +a trusted + + align:start position:0% +a trusted + + + align:start position:0% +a trusted +intermediary to use this intermediary + + align:start position:0% +intermediary to use this intermediary + + + align:start position:0% +intermediary to use this intermediary +idea to + + align:start position:0% +idea to + + + align:start position:0% +idea to +actually make design remote um message + + align:start position:0% +actually make design remote um message + + + align:start position:0% +actually make design remote um message +based commun systems communication + + align:start position:0% +based commun systems communication + + + align:start position:0% +based commun systems communication +systems where the Cent service don't + + align:start position:0% +systems where the Cent service don't + + + align:start position:0% +systems where the Cent service don't +actually have to be up and running at + + align:start position:0% +actually have to be up and running at + + + align:start position:0% +actually have to be up and running at +the same time so you could actually the + + align:start position:0% +the same time so you could actually the + + + align:start position:0% +the same time so you could actually the +client could send a request + + align:start position:0% +client could send a request + + + align:start position:0% +client could send a request +out to the service but the service is + + align:start position:0% +out to the service but the service is + + + align:start position:0% +out to the service but the service is +actually not up and running so the idea + + align:start position:0% +actually not up and running so the idea + + + align:start position:0% +actually not up and running so the idea +is there's an intermediary that acts as + + align:start position:0% +is there's an intermediary that acts as + + + align:start position:0% +is there's an intermediary that acts as +a broker on behalf of the service and + + align:start position:0% +a broker on behalf of the service and + + + align:start position:0% +a broker on behalf of the service and +buffers the message and then when the + + align:start position:0% +buffers the message and then when the + + + align:start position:0% +buffers the message and then when the +service comes up the service knows to + + align:start position:0% +service comes up the service knows to + + + align:start position:0% +service comes up the service knows to +pull the message from this intermediary + + align:start position:0% +pull the message from this intermediary + + + align:start position:0% +pull the message from this intermediary +that's buer messages for it and then it + + align:start position:0% +that's buer messages for it and then it + + + align:start position:0% +that's buer messages for it and then it +processes the message and then push the + + align:start position:0% +processes the message and then push the + + + align:start position:0% +processes the message and then push the +answer back to the intermediary which + + align:start position:0% +answer back to the intermediary which + + + align:start position:0% +answer back to the intermediary which +then stores the message to some other + + align:start position:0% +then stores the message to some other + + + align:start position:0% +then stores the message to some other +intermediary perhaps and then the client + + align:start position:0% +intermediary perhaps and then the client + + + align:start position:0% +intermediary perhaps and then the client +knows to get the answer from that + + align:start position:0% +knows to get the answer from that + + + align:start position:0% +knows to get the answer from that +intermediate so now we can actually have + + align:start position:0% +intermediate so now we can actually have + + + align:start position:0% +intermediate so now we can actually have +clients and services that interact with + + align:start position:0% +clients and services that interact with + + + align:start position:0% +clients and services that interact with +each other um without actually having to + + align:start position:0% +each other um without actually having to + + + align:start position:0% +each other um without actually having to +be up and running at the same time there + + align:start position:0% +be up and running at the same time there + + + align:start position:0% +be up and running at the same time there +are many examples of this and the notes + + align:start position:0% +are many examples of this and the notes + + + align:start position:0% +are many examples of this and the notes +talk about um various ways of doing + + align:start position:0% +talk about um various ways of doing + + + align:start position:0% +talk about um various ways of doing +intermed various examples of + + align:start position:0% +intermed various examples of + + + align:start position:0% +intermed various examples of +intermediate based + + align:start position:0% +intermediate based + + + align:start position:0% +intermediate based +communication so the Gen summ of what + + align:start position:0% +communication so the Gen summ of what + + + align:start position:0% +communication so the Gen summ of what +we've talked about so far is is that we + + align:start position:0% +we've talked about so far is is that we + + + align:start position:0% +we've talked about so far is is that we +looked at different ways of achieving + + align:start position:0% +looked at different ways of achieving + + + align:start position:0% +looked at different ways of achieving +modularity talked about soft modularity + + align:start position:0% +modularity talked about soft modularity + + + align:start position:0% +modularity talked about soft modularity +last time and today about particular way + + align:start position:0% +last time and today about particular way + + + align:start position:0% +last time and today about particular way +of enforcing modularity using client + + align:start position:0% +of enforcing modularity using client + + + align:start position:0% +of enforcing modularity using client +service organization and the next few + + align:start position:0% +service organization and the next few + + + align:start position:0% +service organization and the next few +lectures we're going to solve a big + + align:start position:0% +lectures we're going to solve a big + + + align:start position:0% +lectures we're going to solve a big +weakness of the current system which is + + align:start position:0% +weakness of the current system which is + + + align:start position:0% +weakness of the current system which is +that you need many different computers + + align:start position:0% +that you need many different computers + + + align:start position:0% +that you need many different computers +so we're going to take these ideas and + + align:start position:0% +so we're going to take these ideas and + + + align:start position:0% +so we're going to take these ideas and +Implement them all on one computer see + + align:start position:0% +Implement them all on one computer see + + + align:start position:0% +Implement them all on one computer see +you next week on Tuesday \ No newline at end of file diff --git a/Rv3xYk85Lq0.txt b/Rv3xYk85Lq0.txt new file mode 100644 index 0000000000000000000000000000000000000000..90b5d3b5368bb06b212c24b12c648efc4bf5d39f --- /dev/null +++ b/Rv3xYk85Lq0.txt @@ -0,0 +1,11688 @@ +align:start position:0% + +foreign + + align:start position:0% + + + + align:start position:0% + +last time we started talking about + + align:start position:0% +last time we started talking about + + + align:start position:0% +last time we started talking about +metric spaces being compact on euclidean + + align:start position:0% +metric spaces being compact on euclidean + + + align:start position:0% +metric spaces being compact on euclidean +space in particular where we showed on + + align:start position:0% +space in particular where we showed on + + + align:start position:0% +space in particular where we showed on +RN that sequentially compact was the + + align:start position:0% +RN that sequentially compact was the + + + align:start position:0% +RN that sequentially compact was the +same as closed and bounded which was the + + align:start position:0% +same as closed and bounded which was the + + + align:start position:0% +same as closed and bounded which was the +same as topologically Compact and notice + + align:start position:0% +same as topologically Compact and notice + + + align:start position:0% +same as topologically Compact and notice +that in these two theorems we use some + + align:start position:0% +that in these two theorems we use some + + + align:start position:0% +that in these two theorems we use some +very important propositions that we've + + align:start position:0% +very important propositions that we've + + + align:start position:0% +very important propositions that we've +learned from real analysis + + align:start position:0% +learned from real analysis + + + align:start position:0% +learned from real analysis +to prove that coast and bounded implied + + align:start position:0% +to prove that coast and bounded implied + + + align:start position:0% +to prove that coast and bounded implied +sequentially compact we had to use the + + align:start position:0% +sequentially compact we had to use the + + + align:start position:0% +sequentially compact we had to use the +bolzanovirus trust serum which + + align:start position:0% +bolzanovirus trust serum which + + + align:start position:0% +bolzanovirus trust serum which +essentially states exactly the condition + + align:start position:0% +essentially states exactly the condition + + + align:start position:0% +essentially states exactly the condition +of sequentially compactness + + align:start position:0% + + + + align:start position:0% + +and to use closed and bounded to show + + align:start position:0% +and to use closed and bounded to show + + + align:start position:0% +and to use closed and bounded to show +topologically compact we had to use the + + align:start position:0% +topologically compact we had to use the + + + align:start position:0% +topologically compact we had to use the +heineboreal theorem + + align:start position:0% + + + + align:start position:0% + +where we trapped our compact set inside + + align:start position:0% +where we trapped our compact set inside + + + align:start position:0% +where we trapped our compact set inside +of a closed Cube and we know that that + + align:start position:0% +of a closed Cube and we know that that + + + align:start position:0% +of a closed Cube and we know that that +closed cube is going to be compact + + align:start position:0% +closed cube is going to be compact + + + align:start position:0% +closed cube is going to be compact +but we don't always have these closed + + align:start position:0% +but we don't always have these closed + + + align:start position:0% +but we don't always have these closed +cubes on Metric spaces right what does + + align:start position:0% +cubes on Metric spaces right what does + + + align:start position:0% +cubes on Metric spaces right what does +it mean for there to be a cube of + + align:start position:0% +it mean for there to be a cube of + + + align:start position:0% +it mean for there to be a cube of +functions + + align:start position:0% +functions + + + align:start position:0% +functions +um and in fact in general these + + align:start position:0% +um and in fact in general these + + + align:start position:0% +um and in fact in general these +implications are not going to be + + align:start position:0% +implications are not going to be + + + align:start position:0% +implications are not going to be +precisely true and small area from last + + align:start position:0% +precisely true and small area from last + + + align:start position:0% +precisely true and small area from last +time last time I stated that + + align:start position:0% +time last time I stated that + + + align:start position:0% +time last time I stated that +sequentially compact was the same as + + align:start position:0% +sequentially compact was the same as + + + align:start position:0% +sequentially compact was the same as +closed and bounded on Metric spaces this + + align:start position:0% +closed and bounded on Metric spaces this + + + align:start position:0% +closed and bounded on Metric spaces this +is not the case + + align:start position:0% +is not the case + + + align:start position:0% +is not the case +um sorry about that + + align:start position:0% +um sorry about that + + + align:start position:0% +um sorry about that +um + + align:start position:0% +um + + + align:start position:0% +um +we are using bosonavirus shots to prove + + align:start position:0% +we are using bosonavirus shots to prove + + + align:start position:0% +we are using bosonavirus shots to prove +this theorem + + align:start position:0% +this theorem + + + align:start position:0% +this theorem +and we need it to show the other + + align:start position:0% +and we need it to show the other + + + align:start position:0% +and we need it to show the other +implication if it was always the same + + align:start position:0% +implication if it was always the same + + + align:start position:0% +implication if it was always the same +then all three of these would always be + + align:start position:0% +then all three of these would always be + + + align:start position:0% +then all three of these would always be +true and it's not metric spaces were + + align:start position:0% +true and it's not metric spaces were + + + align:start position:0% +true and it's not metric spaces were +closed and bounded implies topologically + + align:start position:0% +closed and bounded implies topologically + + + align:start position:0% +closed and bounded implies topologically +compact have the high Noble property and + + align:start position:0% +compact have the high Noble property and + + + align:start position:0% +compact have the high Noble property and +not every metric space has this property + + align:start position:0% +not every metric space has this property + + + align:start position:0% +not every metric space has this property +but what we're going to show today + + align:start position:0% +but what we're going to show today + + + align:start position:0% +but what we're going to show today +is that if we're not on RN if we're on a + + align:start position:0% +is that if we're not on RN if we're on a + + + align:start position:0% +is that if we're not on RN if we're on a +general metric space + + align:start position:0% + + + + align:start position:0% + +we still have + + align:start position:0% +we still have + + + align:start position:0% +we still have +the following implications we already + + align:start position:0% +the following implications we already + + + align:start position:0% +the following implications we already +know that sequentially Compact and + + align:start position:0% +know that sequentially Compact and + + + align:start position:0% +know that sequentially Compact and +topologically compact implies closed and + + align:start position:0% +topologically compact implies closed and + + + align:start position:0% +topologically compact implies closed and +bounded which is a very helpful thing + + align:start position:0% +bounded which is a very helpful thing + + + align:start position:0% +bounded which is a very helpful thing +right if you want to show that a metric + + align:start position:0% +right if you want to show that a metric + + + align:start position:0% +right if you want to show that a metric +space is it isn't compact you just have + + align:start position:0% +space is it isn't compact you just have + + + align:start position:0% +space is it isn't compact you just have +to show that it's not closed or at least + + align:start position:0% +to show that it's not closed or at least + + + align:start position:0% +to show that it's not closed or at least +not bounded + + align:start position:0% +not bounded + + + align:start position:0% +not bounded +but we're still going to have the + + align:start position:0% +but we're still going to have the + + + align:start position:0% +but we're still going to have the +following implication what we're going + + align:start position:0% +following implication what we're going + + + align:start position:0% +following implication what we're going +to show today we're going to show that + + align:start position:0% +to show today we're going to show that + + + align:start position:0% +to show today we're going to show that +sequentially compact + + align:start position:0% +sequentially compact + + + align:start position:0% +sequentially compact +it's the same as topologically compact + + align:start position:0% + + + + align:start position:0% + +in fact we're going to show two more + + align:start position:0% +in fact we're going to show two more + + + align:start position:0% +in fact we're going to show two more +properties that emphasize the importance + + align:start position:0% +properties that emphasize the importance + + + align:start position:0% +properties that emphasize the importance +of compact metric spaces in general it's + + align:start position:0% +of compact metric spaces in general it's + + + align:start position:0% +of compact metric spaces in general it's +going to be a very proof intensive day + + align:start position:0% +going to be a very proof intensive day + + + align:start position:0% +going to be a very proof intensive day +but I hope you stick with it through me + + align:start position:0% +but I hope you stick with it through me + + + align:start position:0% +but I hope you stick with it through me +sorry stick with it with me + + align:start position:0% +sorry stick with it with me + + + align:start position:0% +sorry stick with it with me +um + + align:start position:0% +um + + + align:start position:0% +um +so yeah that's our goal for today before + + align:start position:0% +so yeah that's our goal for today before + + + align:start position:0% +so yeah that's our goal for today before +we show sequentially compact implies + + align:start position:0% +we show sequentially compact implies + + + align:start position:0% +we show sequentially compact implies +topologically Compact and thus and + + align:start position:0% +topologically Compact and thus and + + + align:start position:0% +topologically Compact and thus and +furthermore the opposite direction first + + align:start position:0% +furthermore the opposite direction first + + + align:start position:0% +furthermore the opposite direction first +we're going to start by proving some + + align:start position:0% +we're going to start by proving some + + + align:start position:0% +we're going to start by proving some +lemmas about sequential compactness to + + align:start position:0% +lemmas about sequential compactness to + + + align:start position:0% +lemmas about sequential compactness to +make our job just a little bit easier in + + align:start position:0% +make our job just a little bit easier in + + + align:start position:0% +make our job just a little bit easier in +the long term and in fact these summers + + align:start position:0% +the long term and in fact these summers + + + align:start position:0% +the long term and in fact these summers +are going to be used throughout the rest + + align:start position:0% +are going to be used throughout the rest + + + align:start position:0% +are going to be used throughout the rest +of the class so please pay attention + + align:start position:0% +of the class so please pay attention + + + align:start position:0% +of the class so please pay attention +so first we have what is known as + + align:start position:0% +so first we have what is known as + + + align:start position:0% +so first we have what is known as +dilemma the little big number Lemma + + align:start position:0% + + + + align:start position:0% + +we're here I'm just not writing out + + align:start position:0% +we're here I'm just not writing out + + + align:start position:0% +we're here I'm just not writing out +number but the idea is given our metrics + + align:start position:0% +number but the idea is given our metrics + + + align:start position:0% +number but the idea is given our metrics +base X + + align:start position:0% +base X + + + align:start position:0% +base X +is sequentially compact + + align:start position:0% + + + + align:start position:0% + +if I have an open cover of x + + align:start position:0% + + + + align:start position:0% + +let's call this our uis + + align:start position:0% + + + + align:start position:0% + +then there exists + + align:start position:0% +then there exists + + + align:start position:0% +then there exists +in R bigger than zero such that for all + + align:start position:0% +in R bigger than zero such that for all + + + align:start position:0% +in R bigger than zero such that for all +x and x + + align:start position:0% +x and x + + + align:start position:0% +x and x +the ball of radius R round X + + align:start position:0% +the ball of radius R round X + + + align:start position:0% +the ball of radius R round X +is contained in one of the uis for some + + align:start position:0% +is contained in one of the uis for some + + + align:start position:0% +is contained in one of the uis for some +I + + align:start position:0% + + + + align:start position:0% + +now let's draw a picture of what I'm + + align:start position:0% +now let's draw a picture of what I'm + + + align:start position:0% +now let's draw a picture of what I'm +actually describing here because this + + align:start position:0% +actually describing here because this + + + align:start position:0% +actually describing here because this +quantifier logic can be a little bit + + align:start position:0% +quantifier logic can be a little bit + + + align:start position:0% +quantifier logic can be a little bit +confusing the first time you see it + + align:start position:0% +confusing the first time you see it + + + align:start position:0% +confusing the first time you see it +so here let's just draw a little blob + + align:start position:0% +so here let's just draw a little blob + + + align:start position:0% +so here let's just draw a little blob +for a metric SpaceX + + align:start position:0% +for a metric SpaceX + + + align:start position:0% +for a metric SpaceX +and what we're going to do is find an + + align:start position:0% +and what we're going to do is find an + + + align:start position:0% +and what we're going to do is find an +open cover of this by the UI so I'll + + align:start position:0% +open cover of this by the UI so I'll + + + align:start position:0% +open cover of this by the UI so I'll +draw these by circles + + align:start position:0% + + + + align:start position:0% + +so these are our uis + + align:start position:0% + + + + align:start position:0% + +okay there we go + + align:start position:0% +okay there we go + + + align:start position:0% +okay there we go +and now for every x in x we claim that + + align:start position:0% +and now for every x in x we claim that + + + align:start position:0% +and now for every x in x we claim that +there exists a ball of radius r + + align:start position:0% +there exists a ball of radius r + + + align:start position:0% +there exists a ball of radius r +around X + + align:start position:0% +around X + + + align:start position:0% +around X +such that it's contained in only one of + + align:start position:0% +such that it's contained in only one of + + + align:start position:0% +such that it's contained in only one of +these open sets + + align:start position:0% +these open sets + + + align:start position:0% +these open sets +or sorry not only one that it's fully + + align:start position:0% +or sorry not only one that it's fully + + + align:start position:0% +or sorry not only one that it's fully +contained in one of these sets + + align:start position:0% + + + + align:start position:0% + +um and this might ring out to you as + + align:start position:0% +um and this might ring out to you as + + + align:start position:0% +um and this might ring out to you as +being true if you want to prove + + align:start position:0% +being true if you want to prove + + + align:start position:0% +being true if you want to prove +topologically compact it's the same as + + align:start position:0% +topologically compact it's the same as + + + align:start position:0% +topologically compact it's the same as +sequentially compact what we're going to + + align:start position:0% +sequentially compact what we're going to + + + align:start position:0% +sequentially compact what we're going to +do in the long term is assume that we're + + align:start position:0% +do in the long term is assume that we're + + + align:start position:0% +do in the long term is assume that we're +sequentially compact take an open cover + + align:start position:0% +sequentially compact take an open cover + + + align:start position:0% +sequentially compact take an open cover +and use this R to construct our + + align:start position:0% +and use this R to construct our + + + align:start position:0% +and use this R to construct our +conclusion + + align:start position:0% +conclusion + + + align:start position:0% +conclusion +first we have to prove the steps + + align:start position:0% +first we have to prove the steps + + + align:start position:0% +first we have to prove the steps +and the proof + + align:start position:0% +and the proof + + + align:start position:0% +and the proof +is going to be as pretty usual for + + align:start position:0% +is going to be as pretty usual for + + + align:start position:0% +is going to be as pretty usual for +sequential compactness our proof is + + align:start position:0% +sequential compactness our proof is + + + align:start position:0% +sequential compactness our proof is +going to be by contradiction + + align:start position:0% +going to be by contradiction + + + align:start position:0% +going to be by contradiction +we're going to + + align:start position:0% +we're going to + + + align:start position:0% +we're going to +use contradiction assume + + align:start position:0% + + + + align:start position:0% + +not true + + align:start position:0% + + + + align:start position:0% + +what does it mean for this statement to + + align:start position:0% +what does it mean for this statement to + + + align:start position:0% +what does it mean for this statement to +be not true well it means that for every + + align:start position:0% +be not true well it means that for every + + + align:start position:0% +be not true well it means that for every +r + + align:start position:0% +r + + + align:start position:0% +r +bigger than zero there exists some X + + align:start position:0% +bigger than zero there exists some X + + + align:start position:0% +bigger than zero there exists some X +in x + + align:start position:0% +in x + + + align:start position:0% +in x +such that the ball of radius R around an + + align:start position:0% +such that the ball of radius R around an + + + align:start position:0% +such that the ball of radius R around an +X is not contained in any of the uis + + align:start position:0% +X is not contained in any of the uis + + + align:start position:0% +X is not contained in any of the uis +it's covered It's contained in a cover + + align:start position:0% +it's covered It's contained in a cover + + + align:start position:0% +it's covered It's contained in a cover +of the uis it's just not fully contained + + align:start position:0% +of the uis it's just not fully contained + + + align:start position:0% +of the uis it's just not fully contained +in one of them at least + + align:start position:0% +in one of them at least + + + align:start position:0% +in one of them at least +and what we're going to do is use this + + align:start position:0% +and what we're going to do is use this + + + align:start position:0% +and what we're going to do is use this +to construct a sequence and take the + + align:start position:0% +to construct a sequence and take the + + + align:start position:0% +to construct a sequence and take the +convergent subsequence and reach + + align:start position:0% +convergent subsequence and reach + + + align:start position:0% +convergent subsequence and reach +contradiction so choose + + align:start position:0% + + + + align:start position:0% + +for each + + align:start position:0% +for each + + + align:start position:0% +for each +r equal to 1 over n + + align:start position:0% +r equal to 1 over n + + + align:start position:0% +r equal to 1 over n +choose x n + + align:start position:0% +choose x n + + + align:start position:0% +choose x n +to satisfy + + align:start position:0% + + + + align:start position:0% + +the above property so we're going to + + align:start position:0% +the above property so we're going to + + + align:start position:0% +the above property so we're going to +choose the points in our sequence to be + + align:start position:0% +choose the points in our sequence to be + + + align:start position:0% +choose the points in our sequence to be +the xn or at least one of the xn such + + align:start position:0% +the xn or at least one of the xn such + + + align:start position:0% +the xn or at least one of the xn such +that the ball of radius r or the ball of + + align:start position:0% +that the ball of radius r or the ball of + + + align:start position:0% +that the ball of radius r or the ball of +radius one over n around X is not + + align:start position:0% +radius one over n around X is not + + + align:start position:0% +radius one over n around X is not +contained in any of the uis and we know + + align:start position:0% +contained in any of the uis and we know + + + align:start position:0% +contained in any of the uis and we know +that this is going to be true because 1 + + align:start position:0% +that this is going to be true because 1 + + + align:start position:0% +that this is going to be true because 1 +over n is going to be bigger than zero + + align:start position:0% +over n is going to be bigger than zero + + + align:start position:0% +over n is going to be bigger than zero +so what are we going to do with the + + align:start position:0% +so what are we going to do with the + + + align:start position:0% +so what are we going to do with the +sequence what we're going to start by + + align:start position:0% +sequence what we're going to start by + + + align:start position:0% +sequence what we're going to start by +taking a convergent subsequence right + + align:start position:0% +taking a convergent subsequence right + + + align:start position:0% +taking a convergent subsequence right +we're going to use the fact that we're + + align:start position:0% +we're going to use the fact that we're + + + align:start position:0% +we're going to use the fact that we're +sequentially compact + + align:start position:0% +sequentially compact + + + align:start position:0% +sequentially compact +and this trend will carry on throughout + + align:start position:0% +and this trend will carry on throughout + + + align:start position:0% +and this trend will carry on throughout +the day so + + align:start position:0% +the day so + + + align:start position:0% +the day so +we have + + align:start position:0% + + + + align:start position:0% + +a convergent subsequence + + align:start position:0% + + + + align:start position:0% + +let's call it X and K converging to X of + + align:start position:0% +let's call it X and K converging to X of + + + align:start position:0% +let's call it X and K converging to X of +course that's what we usually Let It Be + + align:start position:0% +course that's what we usually Let It Be + + + align:start position:0% +course that's what we usually Let It Be +okay so what are we going to do we want + + align:start position:0% +okay so what are we going to do we want + + + align:start position:0% +okay so what are we going to do we want +to reach the contradiction that there is + + align:start position:0% +to reach the contradiction that there is + + + align:start position:0% +to reach the contradiction that there is +in fact a ball of radius R round one of + + align:start position:0% +in fact a ball of radius R round one of + + + align:start position:0% +in fact a ball of radius R round one of +these X's contained in a UI how do we do + + align:start position:0% +these X's contained in a UI how do we do + + + align:start position:0% +these X's contained in a UI how do we do +that well first we notice that X has to + + align:start position:0% +that well first we notice that X has to + + + align:start position:0% +that well first we notice that X has to +be in one of the uis + + align:start position:0% + + + + align:start position:0% + +X is in u i naught for some I naught + + align:start position:0% +X is in u i naught for some I naught + + + align:start position:0% +X is in u i naught for some I naught +and this is true given that it's an open + + align:start position:0% +and this is true given that it's an open + + + align:start position:0% +and this is true given that it's an open +cover of our space + + align:start position:0% +cover of our space + + + align:start position:0% +cover of our space +and therefore because we're because the + + align:start position:0% +and therefore because we're because the + + + align:start position:0% +and therefore because we're because the +UI not is open + + align:start position:0% +UI not is open + + + align:start position:0% +UI not is open +there exists an R naught bigger than + + align:start position:0% +there exists an R naught bigger than + + + align:start position:0% +there exists an R naught bigger than +zero such that the ball of radius R + + align:start position:0% +zero such that the ball of radius R + + + align:start position:0% +zero such that the ball of radius R +naught + + align:start position:0% +naught + + + align:start position:0% +naught +is contained in u i naught + + align:start position:0% + + + + align:start position:0% + +right now we want to find a subset of + + align:start position:0% +right now we want to find a subset of + + + align:start position:0% +right now we want to find a subset of +this such that we reach our + + align:start position:0% +this such that we reach our + + + align:start position:0% +this such that we reach our +contradiction so + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% +um + + + align:start position:0% +um +choose + + align:start position:0% +choose + + + align:start position:0% +choose +and sufficiently large + + align:start position:0% + + + + align:start position:0% + +so that + + align:start position:0% + + + + align:start position:0% + +one over n + + align:start position:0% +one over n + + + align:start position:0% +one over n +is less than R naught over two + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +uh did you do + + align:start position:0% +uh did you do + + + align:start position:0% +uh did you do +the distance from X to x n + + align:start position:0% +the distance from X to x n + + + align:start position:0% +the distance from X to x n +is less than R naught over two + + align:start position:0% +is less than R naught over two + + + align:start position:0% +is less than R naught over two +and we're going to use this to create a + + align:start position:0% +and we're going to use this to create a + + + align:start position:0% +and we're going to use this to create a +subset of BR naught of x + + align:start position:0% +subset of BR naught of x + + + align:start position:0% +subset of BR naught of x +so how do we do that well we consider + + align:start position:0% + + + + align:start position:0% + +the ball of radius 1 over n + + align:start position:0% +the ball of radius 1 over n + + + align:start position:0% +the ball of radius 1 over n +around X + + align:start position:0% +around X + + + align:start position:0% +around X +or sorry around x n + + align:start position:0% + + + + align:start position:0% + +so for all Y in this set + + align:start position:0% +so for all Y in this set + + + align:start position:0% +so for all Y in this set +we notice that + + align:start position:0% + + + + align:start position:0% + +the distance from X + + align:start position:0% +the distance from X + + + align:start position:0% +the distance from X +to y + + align:start position:0% +to y + + + align:start position:0% +to y +is less than or equal to the distance + + align:start position:0% +is less than or equal to the distance + + + align:start position:0% +is less than or equal to the distance +from X to x n + + align:start position:0% +from X to x n + + + align:start position:0% +from X to x n +plus the distance + + align:start position:0% +plus the distance + + + align:start position:0% +plus the distance +from y to xn this is by the triangle + + align:start position:0% +from y to xn this is by the triangle + + + align:start position:0% +from y to xn this is by the triangle +inequality this term is going to be less + + align:start position:0% +inequality this term is going to be less + + + align:start position:0% +inequality this term is going to be less +than 1 over sorry R naught Over N so R + + align:start position:0% +than 1 over sorry R naught Over N so R + + + align:start position:0% +than 1 over sorry R naught Over N so R +naught over two it's less than one over + + align:start position:0% +naught over two it's less than one over + + + align:start position:0% +naught over two it's less than one over +n Which is less than R naught over two + + align:start position:0% +n Which is less than R naught over two + + + align:start position:0% +n Which is less than R naught over two +Plus + + align:start position:0% +Plus + + + align:start position:0% +Plus +one over uh something that's less than + + align:start position:0% +one over uh something that's less than + + + align:start position:0% +one over uh something that's less than +one over n Which is less than R naught + + align:start position:0% +one over n Which is less than R naught + + + align:start position:0% +one over n Which is less than R naught +over two + + align:start position:0% +over two + + + align:start position:0% +over two +so this is R naught which tells us that + + align:start position:0% +so this is R naught which tells us that + + + align:start position:0% +so this is R naught which tells us that +the ball of radius 1 over n + + align:start position:0% + + + + align:start position:0% + +around x n + + align:start position:0% +around x n + + + align:start position:0% +around x n +is fully contained and the ball of + + align:start position:0% +is fully contained and the ball of + + + align:start position:0% +is fully contained and the ball of +radius R naught around x n sorry not x n + + align:start position:0% +radius R naught around x n sorry not x n + + + align:start position:0% +radius R naught around x n sorry not x n +x + + align:start position:0% +x + + + align:start position:0% +x +which is fully contained and UI naught + + align:start position:0% +which is fully contained and UI naught + + + align:start position:0% +which is fully contained and UI naught +which is our contradiction right because + + align:start position:0% +which is our contradiction right because + + + align:start position:0% +which is our contradiction right because +we claimed at the very beginning that + + align:start position:0% +we claimed at the very beginning that + + + align:start position:0% +we claimed at the very beginning that +none of these balls are going to be + + align:start position:0% +none of these balls are going to be + + + align:start position:0% +none of these balls are going to be +contained in any or fully contained in + + align:start position:0% +contained in any or fully contained in + + + align:start position:0% +contained in any or fully contained in +any of the uis + + align:start position:0% +any of the uis + + + align:start position:0% +any of the uis +so this is still the big number Lemma as + + align:start position:0% +so this is still the big number Lemma as + + + align:start position:0% +so this is still the big number Lemma as +a small note the largest such R such + + align:start position:0% +a small note the largest such R such + + + align:start position:0% +a small note the largest such R such +that this property holds is known as the + + align:start position:0% +that this property holds is known as the + + + align:start position:0% +that this property holds is known as the +big number and this comes up in a number + + align:start position:0% +big number and this comes up in a number + + + align:start position:0% +big number and this comes up in a number +of other applications we're just not + + align:start position:0% +of other applications we're just not + + + align:start position:0% +of other applications we're just not +going to be talking about them today + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +now we have a way of refining our open + + align:start position:0% +now we have a way of refining our open + + + align:start position:0% +now we have a way of refining our open +cover to refine our open cover to the + + align:start position:0% +cover to refine our open cover to the + + + align:start position:0% +cover to refine our open cover to the +set of open balls of all the same radius + + align:start position:0% +set of open balls of all the same radius + + + align:start position:0% +set of open balls of all the same radius +but what we need to do is reach a + + align:start position:0% +but what we need to do is reach a + + + align:start position:0% +but what we need to do is reach a +what we need to do + + align:start position:0% +what we need to do + + + align:start position:0% +what we need to do +is get finitely many of these open balls + + align:start position:0% +is get finitely many of these open balls + + + align:start position:0% +is get finitely many of these open balls +for open cover + + align:start position:0% +for open cover + + + align:start position:0% +for open cover +and as such we're going to define a new + + align:start position:0% +and as such we're going to define a new + + + align:start position:0% +and as such we're going to define a new +term + + align:start position:0% +term + + + align:start position:0% +term +so definition + + align:start position:0% + + + + align:start position:0% + +the term is known as totally bounded + + align:start position:0% + + + + align:start position:0% + +a or I should say metric space + + align:start position:0% + + + + align:start position:0% + +let's call it X + + align:start position:0% +let's call it X + + + align:start position:0% +let's call it X +is totally bounded + + align:start position:0% + + + + align:start position:0% + +if + + align:start position:0% +if + + + align:start position:0% +if +for all Epsilon bigger than zero + + align:start position:0% + + + + align:start position:0% + +there exists y1 + + align:start position:0% +there exists y1 + + + align:start position:0% +there exists y1 +through y k + + align:start position:0% +through y k + + + align:start position:0% +through y k +such that + + align:start position:0% +such that + + + align:start position:0% +such that +the union of balls of radius Epsilon + + align:start position:0% +the union of balls of radius Epsilon + + + align:start position:0% +the union of balls of radius Epsilon +around the finitely many y I's + + align:start position:0% + + + + align:start position:0% + +contains X + + align:start position:0% + + + + align:start position:0% + +so it's a very similar picture to this + + align:start position:0% +so it's a very similar picture to this + + + align:start position:0% +so it's a very similar picture to this +only where I have all the same radius r + + align:start position:0% +only where I have all the same radius r + + + align:start position:0% +only where I have all the same radius r +instead of our regular open cover + + align:start position:0% +instead of our regular open cover + + + align:start position:0% +instead of our regular open cover +and what we're going to do is show that + + align:start position:0% +and what we're going to do is show that + + + align:start position:0% +and what we're going to do is show that +sequential compactness implies totally + + align:start position:0% +sequential compactness implies totally + + + align:start position:0% +sequential compactness implies totally +bounded + + align:start position:0% +bounded + + + align:start position:0% +bounded +this is another Lemma of ours + + align:start position:0% +this is another Lemma of ours + + + align:start position:0% +this is another Lemma of ours +okay + + align:start position:0% +okay + + + align:start position:0% +okay +Lemma + + align:start position:0% + + + + align:start position:0% + +sequentially bound sorry sequentially + + align:start position:0% +sequentially bound sorry sequentially + + + align:start position:0% +sequentially bound sorry sequentially +compact + + align:start position:0% + + + + align:start position:0% + +implies totally bounded + + align:start position:0% + + + + align:start position:0% + +as metric spaces + + align:start position:0% +as metric spaces + + + align:start position:0% +as metric spaces +so if your metric space is sequentially + + align:start position:0% +so if your metric space is sequentially + + + align:start position:0% +so if your metric space is sequentially +compact then it's going to be totally + + align:start position:0% +compact then it's going to be totally + + + align:start position:0% +compact then it's going to be totally +bounded + + align:start position:0% +bounded + + + align:start position:0% +bounded +let's prove this proof + + align:start position:0% +let's prove this proof + + + align:start position:0% +let's prove this proof +again our proof is going to be by + + align:start position:0% +again our proof is going to be by + + + align:start position:0% +again our proof is going to be by +contradiction + + align:start position:0% + + + + align:start position:0% + +assume that it's not totally bounded + + align:start position:0% +assume that it's not totally bounded + + + align:start position:0% +assume that it's not totally bounded +then for all Epsilon bigger than zero + + align:start position:0% +then for all Epsilon bigger than zero + + + align:start position:0% +then for all Epsilon bigger than zero +there exists or sorry I should say + + align:start position:0% +there exists or sorry I should say + + + align:start position:0% +there exists or sorry I should say +there does not + + align:start position:0% + + + + align:start position:0% + +exist + + align:start position:0% + + + + align:start position:0% + +finitely many + + align:start position:0% + + + + align:start position:0% + +Epsilon balls + + align:start position:0% +Epsilon balls + + + align:start position:0% +Epsilon balls +that coverage base + + align:start position:0% + + + + align:start position:0% + +what does it mean to be not existent + + align:start position:0% +what does it mean to be not existent + + + align:start position:0% +what does it mean to be not existent +right what does it mean for there to not + + align:start position:0% +right what does it mean for there to not + + + align:start position:0% +right what does it mean for there to not +exist finally many Epsilon balls well + + align:start position:0% +exist finally many Epsilon balls well + + + align:start position:0% +exist finally many Epsilon balls well +this means that there are infinitely + + align:start position:0% +this means that there are infinitely + + + align:start position:0% +this means that there are infinitely +many of them + + align:start position:0% + + + + align:start position:0% + +so it takes + + align:start position:0% + + + + align:start position:0% + +Epsilon balls + + align:start position:0% +Epsilon balls + + + align:start position:0% +Epsilon balls +to cover X + + align:start position:0% + + + + align:start position:0% + +now what we're going to do with this + + align:start position:0% +now what we're going to do with this + + + align:start position:0% +now what we're going to do with this +we're once again going to construct a + + align:start position:0% +we're once again going to construct a + + + align:start position:0% +we're once again going to construct a +sequence and take a convergent + + align:start position:0% +sequence and take a convergent + + + align:start position:0% +sequence and take a convergent +subsequence but we need to somehow use + + align:start position:0% +subsequence but we need to somehow use + + + align:start position:0% +subsequence but we need to somehow use +the fact that there it takes infinitely + + align:start position:0% +the fact that there it takes infinitely + + + align:start position:0% +the fact that there it takes infinitely +many Epsilon balls to cover X + + align:start position:0% +many Epsilon balls to cover X + + + align:start position:0% +many Epsilon balls to cover X +well let's just start by taking any X + + align:start position:0% +well let's just start by taking any X + + + align:start position:0% +well let's just start by taking any X + + align:start position:0% + + + align:start position:0% +be an X + + align:start position:0% +be an X + + + align:start position:0% +be an X +and now we want to construct an x two + + align:start position:0% +and now we want to construct an x two + + + align:start position:0% +and now we want to construct an x two +such that there's no koshy subsequence + + align:start position:0% +such that there's no koshy subsequence + + + align:start position:0% +such that there's no koshy subsequence +of the X ends so let's take X2 + + align:start position:0% +of the X ends so let's take X2 + + + align:start position:0% +of the X ends so let's take X2 +to be an X not including the ball of + + align:start position:0% +to be an X not including the ball of + + + align:start position:0% +to be an X not including the ball of +radius Epsilon around X1 + + align:start position:0% +radius Epsilon around X1 + + + align:start position:0% +radius Epsilon around X1 +now let's do this let's continue this + + align:start position:0% +now let's do this let's continue this + + + align:start position:0% +now let's do this let's continue this +process + + align:start position:0% +process + + + align:start position:0% +process +let X N be an X not including + + align:start position:0% +let X N be an X not including + + + align:start position:0% +let X N be an X not including +the union of balls of radius Epsilon + + align:start position:0% +the union of balls of radius Epsilon + + + align:start position:0% +the union of balls of radius Epsilon +around x i + + align:start position:0% + + + + align:start position:0% + +now why are we doing this we want to + + align:start position:0% +now why are we doing this we want to + + + align:start position:0% +now why are we doing this we want to +create a sequence of points such that + + align:start position:0% +create a sequence of points such that + + + align:start position:0% +create a sequence of points such that +every the distance between every point + + align:start position:0% +every the distance between every point + + + align:start position:0% +every the distance between every point +is bigger than Epsilon which we have + + align:start position:0% +is bigger than Epsilon which we have + + + align:start position:0% +is bigger than Epsilon which we have +immediately from this + + align:start position:0% +immediately from this + + + align:start position:0% +immediately from this +the distance from x i to x j is always + + align:start position:0% +the distance from x i to x j is always + + + align:start position:0% +the distance from x i to x j is always +bigger than Epsilon by construction + + align:start position:0% +bigger than Epsilon by construction + + + align:start position:0% +bigger than Epsilon by construction +because if it wasn't less than Epsilon + + align:start position:0% +because if it wasn't less than Epsilon + + + align:start position:0% +because if it wasn't less than Epsilon +then it would be contained in the ball + + align:start position:0% +then it would be contained in the ball + + + align:start position:0% +then it would be contained in the ball +of radius Epsilon around one of the + + align:start position:0% +of radius Epsilon around one of the + + + align:start position:0% +of radius Epsilon around one of the +other X I's + + align:start position:0% +other X I's + + + align:start position:0% +other X I's +so what does this tell us + + align:start position:0% +so what does this tell us + + + align:start position:0% +so what does this tell us +this tells us that our sequence can + + align:start position:0% +this tells us that our sequence can + + + align:start position:0% +this tells us that our sequence can +never be koshy right if our sequence was + + align:start position:0% +never be koshy right if our sequence was + + + align:start position:0% +never be koshy right if our sequence was +koshy or a subsequence was koshy + + align:start position:0% +koshy or a subsequence was koshy + + + align:start position:0% +koshy or a subsequence was koshy +then the distance between subsequent + + align:start position:0% +then the distance between subsequent + + + align:start position:0% +then the distance between subsequent +points has to be able to get less than + + align:start position:0% +points has to be able to get less than + + + align:start position:0% +points has to be able to get less than +Epsilon + + align:start position:0% +Epsilon + + + align:start position:0% +Epsilon +which is not the case + + align:start position:0% +which is not the case + + + align:start position:0% +which is not the case +so what we notice + + align:start position:0% +so what we notice + + + align:start position:0% +so what we notice +is that there are no + + align:start position:0% + + + + align:start position:0% + +koshy subsequences + + align:start position:0% + + + + align:start position:0% + +of the sequence x i + + align:start position:0% + + + + align:start position:0% + +and this is going to be our + + align:start position:0% +and this is going to be our + + + align:start position:0% +and this is going to be our +contradiction why + + align:start position:0% +contradiction why + + + align:start position:0% +contradiction why +because this is a sequence in a + + align:start position:0% +because this is a sequence in a + + + align:start position:0% +because this is a sequence in a +sequentially compact metrics base so we + + align:start position:0% +sequentially compact metrics base so we + + + align:start position:0% +sequentially compact metrics base so we +know that there has to exist a + + align:start position:0% +know that there has to exist a + + + align:start position:0% +know that there has to exist a +convergent subsequence but being + + align:start position:0% +convergent subsequence but being + + + align:start position:0% +convergent subsequence but being +convergent implies that it's going to be + + align:start position:0% +convergent implies that it's going to be + + + align:start position:0% +convergent implies that it's going to be +koshy we've shown this on the second day + + align:start position:0% +koshy we've shown this on the second day + + + align:start position:0% +koshy we've shown this on the second day +in our general theory of metric spaces + + align:start position:0% +in our general theory of metric spaces + + + align:start position:0% +in our general theory of metric spaces +so what we've shown is that + + align:start position:0% +so what we've shown is that + + + align:start position:0% +so what we've shown is that +there should be a koshy subsequence but + + align:start position:0% +there should be a koshy subsequence but + + + align:start position:0% +there should be a koshy subsequence but +there is no koshy subsequence so this is + + align:start position:0% +there is no koshy subsequence so this is + + + align:start position:0% +there is no koshy subsequence so this is +our contradiction + + align:start position:0% +our contradiction + + + align:start position:0% +our contradiction +and that concludes the proof + + align:start position:0% + + + + align:start position:0% + +and these two lemmas the lebeg number + + align:start position:0% +and these two lemmas the lebeg number + + + align:start position:0% +and these two lemmas the lebeg number +Lema and this one right here are going + + align:start position:0% +Lema and this one right here are going + + + align:start position:0% +Lema and this one right here are going +to be all we need to show that + + align:start position:0% +to be all we need to show that + + + align:start position:0% +to be all we need to show that +sequentially compact implies + + align:start position:0% +sequentially compact implies + + + align:start position:0% +sequentially compact implies +topologically compact + + align:start position:0% +topologically compact + + + align:start position:0% +topologically compact +so let's start that proof serum + + align:start position:0% + + + + align:start position:0% + +sequentially compact + + align:start position:0% + + + + align:start position:0% + +is the same + + align:start position:0% +is the same + + + align:start position:0% +is the same +as topologically compact as metric + + align:start position:0% +as topologically compact as metric + + + align:start position:0% +as topologically compact as metric +spaces + + align:start position:0% + + + + align:start position:0% + +so let's start the proof proof + + align:start position:0% + + + + align:start position:0% + +assume + + align:start position:0% +assume + + + align:start position:0% +assume +sequentially compact + + align:start position:0% + + + + align:start position:0% + +Inlet + + align:start position:0% +Inlet + + + align:start position:0% +Inlet +UI + + align:start position:0% + + + + align:start position:0% + +be an open cover of the metrics base X + + align:start position:0% + + + + align:start position:0% + +what we then know by the little big + + align:start position:0% +what we then know by the little big + + + align:start position:0% +what we then know by the little big +number Lema is that there exists an R + + align:start position:0% +number Lema is that there exists an R + + + align:start position:0% +number Lema is that there exists an R +bigger than zero such that balls of + + align:start position:0% +bigger than zero such that balls of + + + align:start position:0% +bigger than zero such that balls of +radius R are contained in one of the uis + + align:start position:0% +radius R are contained in one of the uis + + + align:start position:0% +radius R are contained in one of the uis +so therefore + + align:start position:0% +so therefore + + + align:start position:0% +so therefore +by the big number Lemma + + align:start position:0% + + + + align:start position:0% + +there exists + + align:start position:0% +there exists + + + align:start position:0% +there exists +and R bigger than zero such that balls + + align:start position:0% +and R bigger than zero such that balls + + + align:start position:0% +and R bigger than zero such that balls +of radius all around X + + align:start position:0% +of radius all around X + + + align:start position:0% +of radius all around X +are contained in u i for some I + + align:start position:0% + + + + align:start position:0% + +IE for every X there exists some I such + + align:start position:0% +IE for every X there exists some I such + + + align:start position:0% +IE for every X there exists some I such +that this is true + + align:start position:0% +that this is true + + + align:start position:0% +that this is true +and now how do we go from this to + + align:start position:0% +and now how do we go from this to + + + align:start position:0% +and now how do we go from this to +finitely many of these uis well here we + + align:start position:0% +finitely many of these uis well here we + + + align:start position:0% +finitely many of these uis well here we +use the following Nama we know that it's + + align:start position:0% +use the following Nama we know that it's + + + align:start position:0% +use the following Nama we know that it's +totally bounded so given this R bigger + + align:start position:0% +totally bounded so given this R bigger + + + align:start position:0% +totally bounded so given this R bigger +than zero + + align:start position:0% +than zero + + + align:start position:0% +than zero +let R be equal to Epsilon and the + + align:start position:0% +let R be equal to Epsilon and the + + + align:start position:0% +let R be equal to Epsilon and the +definition of totally bounded + + align:start position:0% +definition of totally bounded + + + align:start position:0% +definition of totally bounded +and then we know that there exists + + align:start position:0% + + + + align:start position:0% + +finitely many + + align:start position:0% + + + + align:start position:0% + +y1 + + align:start position:0% +y1 + + + align:start position:0% +y1 +through y k + + align:start position:0% +through y k + + + align:start position:0% +through y k +such that X + + align:start position:0% +such that X + + + align:start position:0% +such that X +is contained + + align:start position:0% +is contained + + + align:start position:0% +is contained +in balls of radius in the union of balls + + align:start position:0% +in balls of radius in the union of balls + + + align:start position:0% +in balls of radius in the union of balls +of radius R around y i + + align:start position:0% +of radius R around y i + + + align:start position:0% +of radius R around y i +from I equals 1 to K + + align:start position:0% +from I equals 1 to K + + + align:start position:0% +from I equals 1 to K +but we want to go from this to a finite + + align:start position:0% +but we want to go from this to a finite + + + align:start position:0% +but we want to go from this to a finite +cover from we want to go from this to a + + align:start position:0% +cover from we want to go from this to a + + + align:start position:0% +cover from we want to go from this to a +finite sub cover + + align:start position:0% +finite sub cover + + + align:start position:0% +finite sub cover +but what we notice + + align:start position:0% +but what we notice + + + align:start position:0% +but what we notice +is that each of these ball of radius R + + align:start position:0% +is that each of these ball of radius R + + + align:start position:0% +is that each of these ball of radius R +is contained in one of the uis + + align:start position:0% +is contained in one of the uis + + + align:start position:0% +is contained in one of the uis +so right now this is going to be + + align:start position:0% +so right now this is going to be + + + align:start position:0% +so right now this is going to be +contained in the union of uij where I J + + align:start position:0% +contained in the union of uij where I J + + + align:start position:0% +contained in the union of uij where I J +is the one such that the balls of radius + + align:start position:0% +is the one such that the balls of radius + + + align:start position:0% +is the one such that the balls of radius +are around y i + + align:start position:0% +are around y i + + + align:start position:0% +are around y i +is contained in the ball sorry is + + align:start position:0% +is contained in the ball sorry is + + + align:start position:0% +is contained in the ball sorry is +contained in uij + + align:start position:0% + + + + align:start position:0% + +and then we're done + + align:start position:0% +and then we're done + + + align:start position:0% +and then we're done +with the forward Direction + + align:start position:0% +with the forward Direction + + + align:start position:0% +with the forward Direction +right because we've gone from an open + + align:start position:0% +right because we've gone from an open + + + align:start position:0% +right because we've gone from an open +cover of our sequentially compact metric + + align:start position:0% +cover of our sequentially compact metric + + + align:start position:0% +cover of our sequentially compact metric +space and reached a finite subcover + + align:start position:0% + + + + align:start position:0% + +so that shows a sequentially compact + + align:start position:0% +so that shows a sequentially compact + + + align:start position:0% +so that shows a sequentially compact +implies topologically compact + + align:start position:0% +implies topologically compact + + + align:start position:0% +implies topologically compact +the other direction is going to be + + align:start position:0% +the other direction is going to be + + + align:start position:0% +the other direction is going to be +mildly harder but is still going to be + + align:start position:0% +mildly harder but is still going to be + + + align:start position:0% +mildly harder but is still going to be +essentially + + align:start position:0% +essentially + + + align:start position:0% +essentially +um + + align:start position:0% +um + + + align:start position:0% +um +it's still going to be essentially we've + + align:start position:0% +it's still going to be essentially we've + + + align:start position:0% +it's still going to be essentially we've +been doing this entire time we're going + + align:start position:0% +been doing this entire time we're going + + + align:start position:0% +been doing this entire time we're going +to assume that it's not sequentially + + align:start position:0% +to assume that it's not sequentially + + + align:start position:0% +to assume that it's not sequentially +compact construct a sequence and take + + align:start position:0% +compact construct a sequence and take + + + align:start position:0% +compact construct a sequence and take +the convergent subsequence and reach a + + align:start position:0% +the convergent subsequence and reach a + + + align:start position:0% +the convergent subsequence and reach a +contradiction somehow + + align:start position:0% +contradiction somehow + + + align:start position:0% +contradiction somehow +okay so suppose + + align:start position:0% +okay so suppose + + + align:start position:0% +okay so suppose +topologically compact + + align:start position:0% + + + + align:start position:0% + +oh I'm holding it backwards Let Me + + align:start position:0% +oh I'm holding it backwards Let Me + + + align:start position:0% +oh I'm holding it backwards Let Me +rewrite this compact + + align:start position:0% + + + + align:start position:0% + +and I suppose for the sake of + + align:start position:0% +and I suppose for the sake of + + + align:start position:0% +and I suppose for the sake of +contradiction + + align:start position:0% +contradiction + + + align:start position:0% +contradiction +assume + + align:start position:0% + + + + align:start position:0% + +for the sake of contradiction + + align:start position:0% +for the sake of contradiction + + + align:start position:0% +for the sake of contradiction +were not sequentially compact + + align:start position:0% + + + + align:start position:0% + +what we're going to do + + align:start position:0% +what we're going to do + + + align:start position:0% +what we're going to do +is or sorry let me first stage what does + + align:start position:0% +is or sorry let me first stage what does + + + align:start position:0% +is or sorry let me first stage what does +it mean to be not sequentially compact + + align:start position:0% +it mean to be not sequentially compact + + + align:start position:0% +it mean to be not sequentially compact +then + + align:start position:0% +then + + + align:start position:0% +then +there exists subsequence + + align:start position:0% + + + + align:start position:0% + +let's call it XM of course + + align:start position:0% + + + + align:start position:0% + +with no convergent subsequence + + align:start position:0% + + + + align:start position:0% + +our goal is to go from this to an open + + align:start position:0% +our goal is to go from this to an open + + + align:start position:0% +our goal is to go from this to an open +cover of our space and show that there + + align:start position:0% +cover of our space and show that there + + + align:start position:0% +cover of our space and show that there +is no finite subcover to reach our + + align:start position:0% +is no finite subcover to reach our + + + align:start position:0% +is no finite subcover to reach our +contradiction + + align:start position:0% +contradiction + + + align:start position:0% +contradiction +well how do we do that well first we + + align:start position:0% +well how do we do that well first we + + + align:start position:0% +well how do we do that well first we +need to note some facts about convergent + + align:start position:0% +need to note some facts about convergent + + + align:start position:0% +need to note some facts about convergent +subsequences + + align:start position:0% +subsequences + + + align:start position:0% +subsequences +firstly + + align:start position:0% + + + + align:start position:0% + +none of the + + align:start position:0% +none of the + + + align:start position:0% +none of the +X eyes actually I guess I should say + + align:start position:0% +X eyes actually I guess I should say + + + align:start position:0% +X eyes actually I guess I should say +firstly just note that none of the X I + + align:start position:0% +firstly just note that none of the X I + + + align:start position:0% +firstly just note that none of the X I +can appear infinitely many times + + align:start position:0% + + + + align:start position:0% + +actually yeah I'm going to call this + + align:start position:0% +actually yeah I'm going to call this + + + align:start position:0% +actually yeah I'm going to call this +firstly + + align:start position:0% +firstly + + + align:start position:0% +firstly +why is this true well if any of the X + + align:start position:0% +why is this true well if any of the X + + + align:start position:0% +why is this true well if any of the X +I's appeared infinitely many times then + + align:start position:0% +I's appeared infinitely many times then + + + align:start position:0% +I's appeared infinitely many times then +that would mean that we could just take + + align:start position:0% +that would mean that we could just take + + + align:start position:0% +that would mean that we could just take +a very trivial subsequence of X I's and + + align:start position:0% +a very trivial subsequence of X I's and + + + align:start position:0% +a very trivial subsequence of X I's and +that will converge to x i + + align:start position:0% +that will converge to x i + + + align:start position:0% +that will converge to x i +so we know that none of them appears + + align:start position:0% +so we know that none of them appears + + + align:start position:0% +so we know that none of them appears +infinitely many times so we can just + + align:start position:0% +infinitely many times so we can just + + + align:start position:0% +infinitely many times so we can just +assume that each one appears finitely + + align:start position:0% +assume that each one appears finitely + + + align:start position:0% +assume that each one appears finitely +many times + + align:start position:0% +many times + + + align:start position:0% +many times +but furthermore + + align:start position:0% +but furthermore + + + align:start position:0% +but furthermore +we know that for all Epsilon bigger than + + align:start position:0% +we know that for all Epsilon bigger than + + + align:start position:0% +we know that for all Epsilon bigger than +nope that's not what I meant to say + + align:start position:0% +nope that's not what I meant to say + + + align:start position:0% +nope that's not what I meant to say +we know that there exists an Epsilon n + + align:start position:0% +we know that there exists an Epsilon n + + + align:start position:0% +we know that there exists an Epsilon n +bigger than zero + + align:start position:0% +bigger than zero + + + align:start position:0% +bigger than zero +such that the ball of radius Epsilon n + + align:start position:0% +such that the ball of radius Epsilon n + + + align:start position:0% +such that the ball of radius Epsilon n +around x n + + align:start position:0% +around x n + + + align:start position:0% +around x n +is simply the set + + align:start position:0% +is simply the set + + + align:start position:0% +is simply the set +xn where here I mean the single point x + + align:start position:0% +xn where here I mean the single point x + + + align:start position:0% +xn where here I mean the single point x +ad + + align:start position:0% +ad + + + align:start position:0% +ad +so I guess to be extra clear I'll write + + align:start position:0% +so I guess to be extra clear I'll write + + + align:start position:0% +so I guess to be extra clear I'll write +this as XJ + + align:start position:0% +this as XJ + + + align:start position:0% +this as XJ +and XJ + + align:start position:0% +and XJ + + + align:start position:0% +and XJ +why is this true well suppose for the + + align:start position:0% +why is this true well suppose for the + + + align:start position:0% +why is this true well suppose for the +sake of contradiction that for every + + align:start position:0% +sake of contradiction that for every + + + align:start position:0% +sake of contradiction that for every +Epsilon bigger than zero there exists uh + + align:start position:0% +Epsilon bigger than zero there exists uh + + + align:start position:0% +Epsilon bigger than zero there exists uh +some X I in a ball of radius Epsilon + + align:start position:0% +some X I in a ball of radius Epsilon + + + align:start position:0% +some X I in a ball of radius Epsilon +around XJ + + align:start position:0% +around XJ + + + align:start position:0% +around XJ +well then that what that would tell us + + align:start position:0% +well then that what that would tell us + + + align:start position:0% +well then that what that would tell us +is that we could take a convergent + + align:start position:0% +is that we could take a convergent + + + align:start position:0% +is that we could take a convergent +subsequence which will converge to x j + + align:start position:0% +subsequence which will converge to x j + + + align:start position:0% +subsequence which will converge to x j +we just choose closer and closer points + + align:start position:0% +we just choose closer and closer points + + + align:start position:0% +we just choose closer and closer points +to x j + + align:start position:0% +to x j + + + align:start position:0% +to x j +so we know that there must exist some + + align:start position:0% +so we know that there must exist some + + + align:start position:0% +so we know that there must exist some +Epsilon n such that this is the case + + align:start position:0% +Epsilon n such that this is the case + + + align:start position:0% +Epsilon n such that this is the case +so we're going to use this to create our + + align:start position:0% +so we're going to use this to create our + + + align:start position:0% +so we're going to use this to create our +open cover + + align:start position:0% +open cover + + + align:start position:0% +open cover +we're going to let these + + align:start position:0% +we're going to let these + + + align:start position:0% +we're going to let these +be the open cover of u j so let's call + + align:start position:0% +be the open cover of u j so let's call + + + align:start position:0% +be the open cover of u j so let's call +them u i or UJS + + align:start position:0% +them u i or UJS + + + align:start position:0% +them u i or UJS +yeah from J equals 1 to Infinity + + align:start position:0% +yeah from J equals 1 to Infinity + + + align:start position:0% +yeah from J equals 1 to Infinity +but this isn't quite an open cover we + + align:start position:0% +but this isn't quite an open cover we + + + align:start position:0% +but this isn't quite an open cover we +don't know that we've fully covered x + + align:start position:0% +don't know that we've fully covered x + + + align:start position:0% +don't know that we've fully covered x +yet so what we're going to do + + align:start position:0% + + + + align:start position:0% + +is that U not + + align:start position:0% +is that U not + + + align:start position:0% +is that U not +be equal to X + + align:start position:0% +be equal to X + + + align:start position:0% +be equal to X +not including any of the terms in our + + align:start position:0% +not including any of the terms in our + + + align:start position:0% +not including any of the terms in our +sequence + + align:start position:0% + + + + align:start position:0% + +now why does this make sense + + align:start position:0% +now why does this make sense + + + align:start position:0% +now why does this make sense +or sorry why is this an open set + + align:start position:0% +or sorry why is this an open set + + + align:start position:0% +or sorry why is this an open set +well we know + + align:start position:0% +well we know + + + align:start position:0% +well we know +that the complement of this set contains + + align:start position:0% +that the complement of this set contains + + + align:start position:0% +that the complement of this set contains +all of its limit points which means that + + align:start position:0% +all of its limit points which means that + + + align:start position:0% +all of its limit points which means that +it's going to be closed + + align:start position:0% +it's going to be closed + + + align:start position:0% +it's going to be closed +as you've shown on your second problem + + align:start position:0% +as you've shown on your second problem + + + align:start position:0% +as you've shown on your second problem +set + + align:start position:0% +set + + + align:start position:0% +set +so what this tells us is that the + + align:start position:0% +so what this tells us is that the + + + align:start position:0% +so what this tells us is that the +complement of the complement is + + align:start position:0% +complement of the complement is + + + align:start position:0% +complement of the complement is +therefore going to be open so U naught + + align:start position:0% +therefore going to be open so U naught + + + align:start position:0% +therefore going to be open so U naught +is open + + align:start position:0% + + + + align:start position:0% + +therefore we've reached an open cover of + + align:start position:0% +therefore we've reached an open cover of + + + align:start position:0% +therefore we've reached an open cover of +our metric Space X we have that X + + align:start position:0% +our metric Space X we have that X + + + align:start position:0% +our metric Space X we have that X +is contained Oh wrong direction + + align:start position:0% +is contained Oh wrong direction + + + align:start position:0% +is contained Oh wrong direction +contained in U naught + + align:start position:0% +contained in U naught + + + align:start position:0% +contained in U naught +Union the infinite Union of uis or uj's + + align:start position:0% +Union the infinite Union of uis or uj's + + + align:start position:0% +Union the infinite Union of uis or uj's +J equals + + align:start position:0% +J equals + + + align:start position:0% +J equals +1 to Infinity + + align:start position:0% +1 to Infinity + + + align:start position:0% +1 to Infinity +now from here we want to reach a finite + + align:start position:0% +now from here we want to reach a finite + + + align:start position:0% +now from here we want to reach a finite +subcover + + align:start position:0% +subcover + + + align:start position:0% +subcover +but notice that every + + align:start position:0% +but notice that every + + + align:start position:0% +but notice that every +Friday sub cover + + align:start position:0% + + + + align:start position:0% + +every subcover is going to be emitting + + align:start position:0% +every subcover is going to be emitting + + + align:start position:0% +every subcover is going to be emitting +infinitely many points + + align:start position:0% + + + + align:start position:0% + +right because every Friday sub cover is + + align:start position:0% +right because every Friday sub cover is + + + align:start position:0% +right because every Friday sub cover is +going to have finitely many of these UJS + + align:start position:0% +going to have finitely many of these UJS + + + align:start position:0% +going to have finitely many of these UJS +but what that tells you + + align:start position:0% + + + + align:start position:0% + +is that infinitely many of them sorry + + align:start position:0% +is that infinitely many of them sorry + + + align:start position:0% +is that infinitely many of them sorry +let me double check what I want to be + + align:start position:0% +let me double check what I want to be + + + align:start position:0% +let me double check what I want to be +saying here + + align:start position:0% + + + + align:start position:0% + +yeah because it's going to Omit + + align:start position:0% +yeah because it's going to Omit + + + align:start position:0% +yeah because it's going to Omit +infinitely many points this tells us + + align:start position:0% +infinitely many points this tells us + + + align:start position:0% +infinitely many points this tells us +that X + + align:start position:0% +that X + + + align:start position:0% +that X +or sorry + + align:start position:0% +or sorry + + + align:start position:0% +or sorry +there is no finite subcover + + align:start position:0% + + + + align:start position:0% + +which is our contradiction because we're + + align:start position:0% +which is our contradiction because we're + + + align:start position:0% +which is our contradiction because we're +assuming topologically compact + + align:start position:0% +assuming topologically compact + + + align:start position:0% +assuming topologically compact +so we've shown the topologically compact + + align:start position:0% +so we've shown the topologically compact + + + align:start position:0% +so we've shown the topologically compact +implies sequentially Compact and that + + align:start position:0% +implies sequentially Compact and that + + + align:start position:0% +implies sequentially Compact and that +concludes the other direction of our + + align:start position:0% +concludes the other direction of our + + + align:start position:0% +concludes the other direction of our +proof and thus we're done + + align:start position:0% +proof and thus we're done + + + align:start position:0% +proof and thus we're done +so + + align:start position:0% +so + + + align:start position:0% +so +this is essentially what we've set off + + align:start position:0% +this is essentially what we've set off + + + align:start position:0% +this is essentially what we've set off +to do from the very beginning which is + + align:start position:0% +to do from the very beginning which is + + + align:start position:0% +to do from the very beginning which is +very motivated by Metric spaces + + align:start position:0% + + + + align:start position:0% + +but as you may guess from the fact that + + align:start position:0% +but as you may guess from the fact that + + + align:start position:0% +but as you may guess from the fact that +sequentially compact implies + + align:start position:0% +sequentially compact implies + + + align:start position:0% +sequentially compact implies +topologically com sorry from the fact + + align:start position:0% +topologically com sorry from the fact + + + align:start position:0% +topologically com sorry from the fact +that sequentially compact implies + + align:start position:0% +that sequentially compact implies + + + align:start position:0% +that sequentially compact implies +totally bounded there's quite a bit more + + align:start position:0% +totally bounded there's quite a bit more + + + align:start position:0% +totally bounded there's quite a bit more +that we can actually be assuming + + align:start position:0% + + + + align:start position:0% + +so what we're going to show for the rest + + align:start position:0% +so what we're going to show for the rest + + + align:start position:0% +so what we're going to show for the rest +of today is two more equivalent + + align:start position:0% +of today is two more equivalent + + + align:start position:0% +of today is two more equivalent +definitions of compactiveness on a + + align:start position:0% +definitions of compactiveness on a + + + align:start position:0% +definitions of compactiveness on a +metric space + + align:start position:0% +metric space + + + align:start position:0% +metric space +and I'll again reiterate these are for a + + align:start position:0% +and I'll again reiterate these are for a + + + align:start position:0% +and I'll again reiterate these are for a +metric space not inherently + + align:start position:0% +metric space not inherently + + + align:start position:0% +metric space not inherently +a topological space as you might see in + + align:start position:0% +a topological space as you might see in + + + align:start position:0% +a topological space as you might see in +18901 but this is the definition of + + align:start position:0% +18901 but this is the definition of + + + align:start position:0% +18901 but this is the definition of +compactness or equivalent definitions of + + align:start position:0% +compactness or equivalent definitions of + + + align:start position:0% +compactness or equivalent definitions of +compactness for a metric space + + align:start position:0% + + + + align:start position:0% + +but before I do that I want to First + + align:start position:0% +but before I do that I want to First + + + align:start position:0% +but before I do that I want to First +State some lemmas + + align:start position:0% +State some lemmas + + + align:start position:0% +State some lemmas +or some corollaries of these facts that + + align:start position:0% +or some corollaries of these facts that + + + align:start position:0% +or some corollaries of these facts that +we've shown so far because they're + + align:start position:0% +we've shown so far because they're + + + align:start position:0% +we've shown so far because they're +deeply important + + align:start position:0% +deeply important + + + align:start position:0% +deeply important +compactness has some very deep results + + align:start position:0% +compactness has some very deep results + + + align:start position:0% +compactness has some very deep results +and I know that this is going to be a + + align:start position:0% +and I know that this is going to be a + + + align:start position:0% +and I know that this is going to be a +very proof intensive class so I want to + + align:start position:0% +very proof intensive class so I want to + + + align:start position:0% +very proof intensive class so I want to +first start by stating some facts that + + align:start position:0% +first start by stating some facts that + + + align:start position:0% +first start by stating some facts that +are a little bit easier to prove but + + align:start position:0% +are a little bit easier to prove but + + + align:start position:0% +are a little bit easier to prove but +also mildly intuitive + + align:start position:0% +also mildly intuitive + + + align:start position:0% +also mildly intuitive +so first recall + + align:start position:0% + + + + align:start position:0% + +a function f from X to Y where X and Y + + align:start position:0% +a function f from X to Y where X and Y + + + align:start position:0% +a function f from X to Y where X and Y +metric spaces + + align:start position:0% +metric spaces + + + align:start position:0% +metric spaces +is continuous + + align:start position:0% + + + + align:start position:0% + +if and only if + + align:start position:0% +if and only if + + + align:start position:0% +if and only if +for every U open + + align:start position:0% +for every U open + + + align:start position:0% +for every U open +in y + + align:start position:0% +in y + + + align:start position:0% +in y +F inverse of U + + align:start position:0% +F inverse of U + + + align:start position:0% +F inverse of U +is open in x + + align:start position:0% + + + + align:start position:0% + +sorry you know I didn't fully write it + + align:start position:0% +sorry you know I didn't fully write it + + + align:start position:0% +sorry you know I didn't fully write it +out but I at least had to verbally F + + align:start position:0% +out but I at least had to verbally F + + + align:start position:0% +out but I at least had to verbally F +inverse of U is going to be open in X + + align:start position:0% +inverse of U is going to be open in X + + + align:start position:0% +inverse of U is going to be open in X +this is the definition of continuous and + + align:start position:0% +this is the definition of continuous and + + + align:start position:0% +this is the definition of continuous and +we're going to do is therefore show + + align:start position:0% +we're going to do is therefore show + + + align:start position:0% +we're going to do is therefore show +llama + + align:start position:0% + + + + align:start position:0% + +if K is a compact compact subset of X + + align:start position:0% +if K is a compact compact subset of X + + + align:start position:0% +if K is a compact compact subset of X +we're here the double sub the double + + align:start position:0% +we're here the double sub the double + + + align:start position:0% +we're here the double sub the double +subsets implies compact + + align:start position:0% +subsets implies compact + + + align:start position:0% +subsets implies compact +so recall that notation + + align:start position:0% +so recall that notation + + + align:start position:0% +so recall that notation +we're going to note that F of K + + align:start position:0% +we're going to note that F of K + + + align:start position:0% +we're going to note that F of K +is compact + + align:start position:0% + + + + align:start position:0% + +and why + + align:start position:0% +and why + + + align:start position:0% +and why +here f + + align:start position:0% +here f + + + align:start position:0% +here f +is a continuous map from X to y + + align:start position:0% + + + + align:start position:0% + +so this is our first statement that + + align:start position:0% +so this is our first statement that + + + align:start position:0% +so this is our first statement that +we're going to prove today + + align:start position:0% +we're going to prove today + + + align:start position:0% +we're going to prove today +or sorry the first statement that we're + + align:start position:0% +or sorry the first statement that we're + + + align:start position:0% +or sorry the first statement that we're +going to prove right now + + align:start position:0% + + + + align:start position:0% + +well we want to somehow reach an open + + align:start position:0% +well we want to somehow reach an open + + + align:start position:0% +well we want to somehow reach an open +cover from + + align:start position:0% +cover from + + + align:start position:0% +cover from +of K + + align:start position:0% +of K + + + align:start position:0% +of K +so let + + align:start position:0% + + + + align:start position:0% + +u i + + align:start position:0% +u i + + + align:start position:0% +u i +be an open cover + + align:start position:0% + + + + align:start position:0% + +of + + align:start position:0% +of + + + align:start position:0% +of +F of K + + align:start position:0% +F of K + + + align:start position:0% +F of K +in y + + align:start position:0% +in y + + + align:start position:0% +in y +then what do we know + + align:start position:0% +then what do we know + + + align:start position:0% +then what do we know +well what this will imply is that F + + align:start position:0% +well what this will imply is that F + + + align:start position:0% +well what this will imply is that F +inverse + + align:start position:0% +inverse + + + align:start position:0% +inverse +of UI + + align:start position:0% +of UI + + + align:start position:0% +of UI +will be a finite sorry not finite will + + align:start position:0% +will be a finite sorry not finite will + + + align:start position:0% +will be a finite sorry not finite will +be + + align:start position:0% +be + + + align:start position:0% +be +an open + + align:start position:0% + + + + align:start position:0% + +cover + + align:start position:0% +cover + + + align:start position:0% +cover +okay + + align:start position:0% +okay + + + align:start position:0% +okay +the fact that the inverse image is cover + + align:start position:0% +the fact that the inverse image is cover + + + align:start position:0% +the fact that the inverse image is cover +K is by the very definition of f of K + + align:start position:0% +K is by the very definition of f of K + + + align:start position:0% +K is by the very definition of f of K +but how do we know that they're open + + align:start position:0% +but how do we know that they're open + + + align:start position:0% +but how do we know that they're open +well this is from the fact that it's + + align:start position:0% +well this is from the fact that it's + + + align:start position:0% +well this is from the fact that it's +continuous these are the inverse images + + align:start position:0% +continuous these are the inverse images + + + align:start position:0% +continuous these are the inverse images +of open sets + + align:start position:0% +of open sets + + + align:start position:0% +of open sets +and so what we know is that we can reach + + align:start position:0% +and so what we know is that we can reach + + + align:start position:0% +and so what we know is that we can reach +a finite subcover + + align:start position:0% + + + + align:start position:0% + +a finite sub cover + + align:start position:0% + + + + align:start position:0% + +given by + + align:start position:0% +given by + + + align:start position:0% +given by +F inverse UI + + align:start position:0% +F inverse UI + + + align:start position:0% +F inverse UI +from let's say I equals one decay + + align:start position:0% +from let's say I equals one decay + + + align:start position:0% +from let's say I equals one decay +and what we're going to do is map this + + align:start position:0% +and what we're going to do is map this + + + align:start position:0% +and what we're going to do is map this +back to F of K notice + + align:start position:0% + + + + align:start position:0% + +that then f + + align:start position:0% +that then f + + + align:start position:0% +that then f +of f inverse of u i + + align:start position:0% + + + + align:start position:0% + +equals + + align:start position:0% +equals + + + align:start position:0% +equals +UI + + align:start position:0% + + + + align:start position:0% + +which is therefore going to give us our + + align:start position:0% +which is therefore going to give us our + + + align:start position:0% +which is therefore going to give us our +open sorry how should I say this + + align:start position:0% +open sorry how should I say this + + + align:start position:0% +open sorry how should I say this +how should I say this this is not + + align:start position:0% +how should I say this this is not + + + align:start position:0% +how should I say this this is not +necessarily directly true + + align:start position:0% +necessarily directly true + + + align:start position:0% +necessarily directly true +what I mean to say + + align:start position:0% +what I mean to say + + + align:start position:0% +what I mean to say +is that the new I + + align:start position:0% +is that the new I + + + align:start position:0% +is that the new I +from I equals 1 to K + + align:start position:0% +from I equals 1 to K + + + align:start position:0% +from I equals 1 to K +is a open cover + + align:start position:0% + + + + align:start position:0% + +of f of K + + align:start position:0% +of f of K + + + align:start position:0% +of f of K +how do you know this + + align:start position:0% +how do you know this + + + align:start position:0% +how do you know this +well we know that the uis are such that + + align:start position:0% +well we know that the uis are such that + + + align:start position:0% +well we know that the uis are such that +oh sorry the F inverse of uis cover K so + + align:start position:0% +oh sorry the F inverse of uis cover K so + + + align:start position:0% +oh sorry the F inverse of uis cover K so +therefore the images of them must cover + + align:start position:0% +therefore the images of them must cover + + + align:start position:0% +therefore the images of them must cover +F of K + + align:start position:0% +F of K + + + align:start position:0% +F of K +and so we've gone from an open cover of + + align:start position:0% +and so we've gone from an open cover of + + + align:start position:0% +and so we've gone from an open cover of +f of K to a finite subcover which shows + + align:start position:0% +f of K to a finite subcover which shows + + + align:start position:0% +f of K to a finite subcover which shows +that is compact in y + + align:start position:0% +that is compact in y + + + align:start position:0% +that is compact in y +so that enter proof that shows that the + + align:start position:0% +so that enter proof that shows that the + + + align:start position:0% +so that enter proof that shows that the +image of compact sets is going to be + + align:start position:0% +image of compact sets is going to be + + + align:start position:0% +image of compact sets is going to be +compact under continuity + + align:start position:0% + + + + align:start position:0% + +and using this and the fact that we have + + align:start position:0% +and using this and the fact that we have + + + align:start position:0% +and using this and the fact that we have +sequential compactness is going to allow + + align:start position:0% +sequential compactness is going to allow + + + align:start position:0% +sequential compactness is going to allow +us to State some very helpful lemmas + + align:start position:0% +us to State some very helpful lemmas + + + align:start position:0% +us to State some very helpful lemmas +so + + align:start position:0% +so + + + align:start position:0% +so +Lemma or sorry not llama Corollary + + align:start position:0% + + + + align:start position:0% + +a map f + + align:start position:0% +a map f + + + align:start position:0% +a map f +from X to let's say the real numbers + + align:start position:0% +from X to let's say the real numbers + + + align:start position:0% +from X to let's say the real numbers +continuous + + align:start position:0% + + + + align:start position:0% + +has a max + + align:start position:0% +has a max + + + align:start position:0% +has a max +Andy min + + align:start position:0% + + + + align:start position:0% + +achieved on compact sets + + align:start position:0% + + + + align:start position:0% + +sets + + align:start position:0% +sets + + + align:start position:0% +sets +by which I mean for every compact subset + + align:start position:0% +by which I mean for every compact subset + + + align:start position:0% +by which I mean for every compact subset +of X the image of it to R is going to + + align:start position:0% +of X the image of it to R is going to + + + align:start position:0% +of X the image of it to R is going to +have a maximum and a minimum achieved + + align:start position:0% +have a maximum and a minimum achieved + + + align:start position:0% +have a maximum and a minimum achieved +in the proof is very short at this point + + align:start position:0% +in the proof is very short at this point + + + align:start position:0% +in the proof is very short at this point +we know that F of K + + align:start position:0% +we know that F of K + + + align:start position:0% +we know that F of K +is going to be compact in r + + align:start position:0% +is going to be compact in r + + + align:start position:0% +is going to be compact in r +which implies that it's going to be + + align:start position:0% +which implies that it's going to be + + + align:start position:0% +which implies that it's going to be +closed and bounded + + align:start position:0% + + + + align:start position:0% + +closed and bounded which you can think + + align:start position:0% +closed and bounded which you can think + + + align:start position:0% +closed and bounded which you can think +of as sequentially compact in the same + + align:start position:0% +of as sequentially compact in the same + + + align:start position:0% +of as sequentially compact in the same +way implies that we can find a maximum + + align:start position:0% +way implies that we can find a maximum + + + align:start position:0% +way implies that we can find a maximum +and a minimum of f of K + + align:start position:0% +and a minimum of f of K + + + align:start position:0% +and a minimum of f of K +this is essentially just the extreme + + align:start position:0% +this is essentially just the extreme + + + align:start position:0% +this is essentially just the extreme +value theorem but it's much more General + + align:start position:0% +value theorem but it's much more General + + + align:start position:0% +value theorem but it's much more General +than the extreme value theorem before + + align:start position:0% +than the extreme value theorem before + + + align:start position:0% +than the extreme value theorem before +the extreme value theorem was a map from + + align:start position:0% +the extreme value theorem was a map from + + + align:start position:0% +the extreme value theorem was a map from +the real numbers or at least a compact + + align:start position:0% +the real numbers or at least a compact + + + align:start position:0% +the real numbers or at least a compact +subset Like A to B to the real numbers + + align:start position:0% +subset Like A to B to the real numbers + + + align:start position:0% +subset Like A to B to the real numbers +now all of a sudden we have the extreme + + align:start position:0% +now all of a sudden we have the extreme + + + align:start position:0% +now all of a sudden we have the extreme +value theorem for for metric spaces + + align:start position:0% +value theorem for for metric spaces + + + align:start position:0% +value theorem for for metric spaces +this fact is extremely helpful + + align:start position:0% +this fact is extremely helpful + + + align:start position:0% +this fact is extremely helpful +um I cannot iterate how important it's + + align:start position:0% +um I cannot iterate how important it's + + + align:start position:0% +um I cannot iterate how important it's +going to be in the long term if you keep + + align:start position:0% +going to be in the long term if you keep + + + align:start position:0% +going to be in the long term if you keep +taking analysis courses but the fact + + align:start position:0% +taking analysis courses but the fact + + + align:start position:0% +taking analysis courses but the fact +that images of compact sets are going to + + align:start position:0% +that images of compact sets are going to + + + align:start position:0% +that images of compact sets are going to +be compact is very very helpful + + align:start position:0% +be compact is very very helpful + + + align:start position:0% +be compact is very very helpful +and helps us with finding a maximum and + + align:start position:0% +and helps us with finding a maximum and + + + align:start position:0% +and helps us with finding a maximum and +a minimum in fact one other way to think + + align:start position:0% +a minimum in fact one other way to think + + + align:start position:0% +a minimum in fact one other way to think +of this theorem is just to take a + + align:start position:0% +of this theorem is just to take a + + + align:start position:0% +of this theorem is just to take a +sequence that converges to the maximum + + align:start position:0% +sequence that converges to the maximum + + + align:start position:0% +sequence that converges to the maximum +and converges to the minimum and there + + align:start position:0% +and converges to the minimum and there + + + align:start position:0% +and converges to the minimum and there +has to be a convergent subsequence of + + align:start position:0% +has to be a convergent subsequence of + + + align:start position:0% +has to be a convergent subsequence of +that sequence because it's sequentially + + align:start position:0% +that sequence because it's sequentially + + + align:start position:0% +that sequence because it's sequentially +compact + + align:start position:0% + + + + align:start position:0% + +besides this + + align:start position:0% +besides this + + + align:start position:0% +besides this +I also want to note + + align:start position:0% +I also want to note + + + align:start position:0% +I also want to note +Corollary + + align:start position:0% + + + + align:start position:0% + +Maps f + + align:start position:0% + + + + align:start position:0% + +given + + align:start position:0% + + + + align:start position:0% + +X is compact + + align:start position:0% + + + + align:start position:0% + +F from X to R + + align:start position:0% +F from X to R + + + align:start position:0% +F from X to R +continuous + + align:start position:0% + + + + align:start position:0% + +is going to be bounded + + align:start position:0% + + + + align:start position:0% + +this is the second corollary right + + align:start position:0% +this is the second corollary right + + + align:start position:0% +this is the second corollary right +before we were using closeness right now + + align:start position:0% +before we were using closeness right now + + + align:start position:0% +before we were using closeness right now +we're using boundedness + + align:start position:0% +we're using boundedness + + + align:start position:0% +we're using boundedness +so this is very helpful + + align:start position:0% +so this is very helpful + + + align:start position:0% +so this is very helpful +um just in order to be able to + + align:start position:0% +um just in order to be able to + + + align:start position:0% +um just in order to be able to +conceptualize what's happening + + align:start position:0% +conceptualize what's happening + + + align:start position:0% +conceptualize what's happening +so the proof is already complete by + + align:start position:0% +so the proof is already complete by + + + align:start position:0% +so the proof is already complete by +before + + align:start position:0% +before + + + align:start position:0% +before +so I will stop there for the moment + + align:start position:0% +so I will stop there for the moment + + + align:start position:0% +so I will stop there for the moment +being + + align:start position:0% +being + + + align:start position:0% +being +now we have one more CRM that I want to + + align:start position:0% +now we have one more CRM that I want to + + + align:start position:0% +now we have one more CRM that I want to +show that will + + align:start position:0% +show that will + + + align:start position:0% +show that will +have some implications + + align:start position:0% +have some implications + + + align:start position:0% +have some implications +for or that will be conceptually helpful + + align:start position:0% +for or that will be conceptually helpful + + + align:start position:0% +for or that will be conceptually helpful +but before I do that I'm going to drink + + align:start position:0% +but before I do that I'm going to drink + + + align:start position:0% +but before I do that I'm going to drink +some water + + align:start position:0% +some water + + + align:start position:0% +some water +the next theorem is known as cantor's + + align:start position:0% +the next theorem is known as cantor's + + + align:start position:0% +the next theorem is known as cantor's +intersection theorem it's one that tells + + align:start position:0% +intersection theorem it's one that tells + + + align:start position:0% +intersection theorem it's one that tells +us things about nested sequences of + + align:start position:0% +us things about nested sequences of + + + align:start position:0% +us things about nested sequences of +compact sets + + align:start position:0% +compact sets + + + align:start position:0% +compact sets +and it's helpful conceptually it's used + + align:start position:0% +and it's helpful conceptually it's used + + + align:start position:0% +and it's helpful conceptually it's used +all the time in fact if you were to take + + align:start position:0% +all the time in fact if you were to take + + + align:start position:0% +all the time in fact if you were to take +a complex analysis class it's one of the + + align:start position:0% +a complex analysis class it's one of the + + + align:start position:0% +a complex analysis class it's one of the +first things that's used to show + + align:start position:0% +first things that's used to show + + + align:start position:0% +first things that's used to show +convergence of line integrals + + align:start position:0% +convergence of line integrals + + + align:start position:0% +convergence of line integrals +for holomorphic functions + + align:start position:0% + + + + align:start position:0% + +so what's the statement + + align:start position:0% + + + + align:start position:0% + +theorem + + align:start position:0% +theorem + + + align:start position:0% +theorem +this is known as cantor's intersection + + align:start position:0% +this is known as cantor's intersection + + + align:start position:0% +this is known as cantor's intersection +theorem + + align:start position:0% + + + + align:start position:0% + +so given + + align:start position:0% + + + + align:start position:0% + +K1 + + align:start position:0% +K1 + + + align:start position:0% +K1 +containing K2 contained in K3 so on and + + align:start position:0% +containing K2 contained in K3 so on and + + + align:start position:0% +containing K2 contained in K3 so on and +so forth each compact + + align:start position:0% + + + + align:start position:0% + +each done empty + + align:start position:0% +each done empty + + + align:start position:0% +each done empty +and compact + + align:start position:0% + + + + align:start position:0% + +by compact I mean topologically or + + align:start position:0% +by compact I mean topologically or + + + align:start position:0% +by compact I mean topologically or +sequentially which we know that that's a + + align:start position:0% +sequentially which we know that that's a + + + align:start position:0% +sequentially which we know that that's a +simple fact that + + align:start position:0% +simple fact that + + + align:start position:0% +simple fact that +let me reiterate + + align:start position:0% +let me reiterate + + + align:start position:0% +let me reiterate +by non-empty and compact I mean + + align:start position:0% +by non-empty and compact I mean + + + align:start position:0% +by non-empty and compact I mean +subsequentially are topologically + + align:start position:0% +subsequentially are topologically + + + align:start position:0% +subsequentially are topologically +because they're the equivalent on a + + align:start position:0% +because they're the equivalent on a + + + align:start position:0% +because they're the equivalent on a +metrics base and here I'm assuming that + + align:start position:0% +metrics base and here I'm assuming that + + + align:start position:0% +metrics base and here I'm assuming that +the compact subsets are in a metric + + align:start position:0% +the compact subsets are in a metric + + + align:start position:0% +the compact subsets are in a metric +space + + align:start position:0% + + + + align:start position:0% + +then + + align:start position:0% + + + + align:start position:0% + +intersection + + align:start position:0% +intersection + + + align:start position:0% +intersection +the kis from I equals 1 to Infinity + + align:start position:0% +the kis from I equals 1 to Infinity + + + align:start position:0% +the kis from I equals 1 to Infinity +is non-empty + + align:start position:0% +is non-empty + + + align:start position:0% +is non-empty +how do we prove this + + align:start position:0% +how do we prove this + + + align:start position:0% +how do we prove this +well we prove this by taking a sequence + + align:start position:0% +well we prove this by taking a sequence + + + align:start position:0% +well we prove this by taking a sequence +of terms in kis + + align:start position:0% +of terms in kis + + + align:start position:0% +of terms in kis +so proof + + align:start position:0% + + + + align:start position:0% + +let x i + + align:start position:0% +let x i + + + align:start position:0% +let x i +B and K i for all I + + align:start position:0% +B and K i for all I + + + align:start position:0% +B and K i for all I +and we know that there exists such an x + + align:start position:0% +and we know that there exists such an x + + + align:start position:0% +and we know that there exists such an x +i because they're not empty so right off + + align:start position:0% +i because they're not empty so right off + + + align:start position:0% +i because they're not empty so right off +the bat we're using the hypothesis + + align:start position:0% +the bat we're using the hypothesis + + + align:start position:0% +the bat we're using the hypothesis +and what we want to note is then that + + align:start position:0% +and what we want to note is then that + + + align:start position:0% +and what we want to note is then that +there exists + + align:start position:0% +there exists + + + align:start position:0% +there exists +or sorry let's focus on K1 for now + + align:start position:0% +or sorry let's focus on K1 for now + + + align:start position:0% +or sorry let's focus on K1 for now +notice + + align:start position:0% +notice + + + align:start position:0% +notice +x i is in K1 + + align:start position:0% +x i is in K1 + + + align:start position:0% +x i is in K1 +for all I + + align:start position:0% + + + + align:start position:0% + +this follows from the fact that it's a + + align:start position:0% +this follows from the fact that it's a + + + align:start position:0% +this follows from the fact that it's a +nested sequence of compact sets + + align:start position:0% +nested sequence of compact sets + + + align:start position:0% +nested sequence of compact sets +so therefore + + align:start position:0% +so therefore + + + align:start position:0% +so therefore +there exists a convergent + + align:start position:0% +there exists a convergent + + + align:start position:0% +there exists a convergent +subsequence + + align:start position:0% + + + + align:start position:0% + +X and K + + align:start position:0% +X and K + + + align:start position:0% +X and K +converging to some a and K1 + + align:start position:0% + + + + align:start position:0% + +and what you can continue to show + + align:start position:0% +and what you can continue to show + + + align:start position:0% +and what you can continue to show +is that it's going to continue to + + align:start position:0% +is that it's going to continue to + + + align:start position:0% +is that it's going to continue to +convergence to a in every Ki + + align:start position:0% +convergence to a in every Ki + + + align:start position:0% +convergence to a in every Ki +so secondly + + align:start position:0% + + + + align:start position:0% + +do + + align:start position:0% + + + + align:start position:0% + +uh + + align:start position:0% +uh + + + align:start position:0% +uh +notice + + align:start position:0% + + + + align:start position:0% + +X I from I equal to 2 to Infinity as + + align:start position:0% +X I from I equal to 2 to Infinity as + + + align:start position:0% +X I from I equal to 2 to Infinity as +opposed to including one + + align:start position:0% +opposed to including one + + + align:start position:0% +opposed to including one +is going to be a subset of K2 + + align:start position:0% +is going to be a subset of K2 + + + align:start position:0% +is going to be a subset of K2 +and therefore there exists a convergent + + align:start position:0% +and therefore there exists a convergent + + + align:start position:0% +and therefore there exists a convergent +subsequence and the convergent + + align:start position:0% +subsequence and the convergent + + + align:start position:0% +subsequence and the convergent +subsequence has a unique limit point + + align:start position:0% +subsequence has a unique limit point + + + align:start position:0% +subsequence has a unique limit point +right this is what we said on the second + + align:start position:0% +right this is what we said on the second + + + align:start position:0% +right this is what we said on the second +day convergence sequences have + + align:start position:0% +day convergence sequences have + + + align:start position:0% +day convergence sequences have +equivalent or have the same + + align:start position:0% + + + + align:start position:0% + +I don't want to say this + + align:start position:0% + + + + align:start position:0% + +have the same limit points so therefore + + align:start position:0% +have the same limit points so therefore + + + align:start position:0% +have the same limit points so therefore +a + + align:start position:0% +a + + + align:start position:0% +a +will be in K2 + + align:start position:0% +will be in K2 + + + align:start position:0% +will be in K2 +and we can continue this process over + + align:start position:0% +and we can continue this process over + + + align:start position:0% +and we can continue this process over +and over again ending up with a single + + align:start position:0% +and over again ending up with a single + + + align:start position:0% +and over again ending up with a single +point at least in all of the kis + + align:start position:0% +point at least in all of the kis + + + align:start position:0% +point at least in all of the kis +so this concludes our proof + + align:start position:0% +so this concludes our proof + + + align:start position:0% +so this concludes our proof +and this is used in complex analysis as + + align:start position:0% +and this is used in complex analysis as + + + align:start position:0% +and this is used in complex analysis as +I stated to + + align:start position:0% +I stated to + + + align:start position:0% +I stated to +go from + + align:start position:0% +go from + + + align:start position:0% +go from +a sequence of triangles that say + + align:start position:0% + + + + align:start position:0% + +so let's say we have the sequence of + + align:start position:0% +so let's say we have the sequence of + + + align:start position:0% +so let's say we have the sequence of +triangles and we know that there exists + + align:start position:0% +triangles and we know that there exists + + + align:start position:0% +triangles and we know that there exists +a point in every one of them + + align:start position:0% +a point in every one of them + + + align:start position:0% +a point in every one of them +we can keep reiterating this pattern and + + align:start position:0% +we can keep reiterating this pattern and + + + align:start position:0% +we can keep reiterating this pattern and +end up with a point in the limit + + align:start position:0% + + + + align:start position:0% + +so we know that the limits of the + + align:start position:0% +so we know that the limits of the + + + align:start position:0% +so we know that the limits of the +intersection is going to be non-empty + + align:start position:0% +intersection is going to be non-empty + + + align:start position:0% +intersection is going to be non-empty +so that's how it's used in complex + + align:start position:0% +so that's how it's used in complex + + + align:start position:0% +so that's how it's used in complex +analysis + + align:start position:0% +analysis + + + align:start position:0% +analysis +of course + + align:start position:0% +of course + + + align:start position:0% +of course +we can't discuss this more fully now + + align:start position:0% +we can't discuss this more fully now + + + align:start position:0% +we can't discuss this more fully now +because it requires a discussion so that + + align:start position:0% +because it requires a discussion so that + + + align:start position:0% +because it requires a discussion so that +takes numerous days of complex analysis + + align:start position:0% +takes numerous days of complex analysis + + + align:start position:0% +takes numerous days of complex analysis +to prove but you know if you take + + align:start position:0% +to prove but you know if you take + + + align:start position:0% +to prove but you know if you take +complex analysis this will be one of the + + align:start position:0% +complex analysis this will be one of the + + + align:start position:0% +complex analysis this will be one of the +first things you see + + align:start position:0% +first things you see + + + align:start position:0% +first things you see +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so what we're going to do with this new + + align:start position:0% +so what we're going to do with this new + + + align:start position:0% +so what we're going to do with this new +theorem what we're going to define a new + + align:start position:0% +theorem what we're going to define a new + + + align:start position:0% +theorem what we're going to define a new +property + + align:start position:0% +property + + + align:start position:0% +property +definition + + align:start position:0% + + + + align:start position:0% + +a collection of closed sets + + align:start position:0% + + + + align:start position:0% + +notice here that I'm assuming closed and + + align:start position:0% +notice here that I'm assuming closed and + + + align:start position:0% +notice here that I'm assuming closed and +not compact + + align:start position:0% + + + + align:start position:0% + +is + + align:start position:0% +is + + + align:start position:0% +is +uh or has + + align:start position:0% + + + + align:start position:0% + +the finite intersection property + + align:start position:0% + + + + align:start position:0% + +intersection property + + align:start position:0% + + + + align:start position:0% + +every + + align:start position:0% + + + + align:start position:0% + +finite subsection + + align:start position:0% + + + + align:start position:0% + +I.E if I take friendly many of the + + align:start position:0% +I.E if I take friendly many of the + + + align:start position:0% +I.E if I take friendly many of the +closets + + align:start position:0% + + + + align:start position:0% + +we're going to assume that it has + + align:start position:0% +we're going to assume that it has + + + align:start position:0% +we're going to assume that it has +non-empty end intersection + + align:start position:0% + + + + align:start position:0% + +we know that this is already going to be + + align:start position:0% +we know that this is already going to be + + + align:start position:0% +we know that this is already going to be +true for compact sets because the + + align:start position:0% +true for compact sets because the + + + align:start position:0% +true for compact sets because the +infinite intersection of them is not + + align:start position:0% +infinite intersection of them is not + + + align:start position:0% +infinite intersection of them is not +empty but this statement is a little bit + + align:start position:0% +empty but this statement is a little bit + + + align:start position:0% +empty but this statement is a little bit +more General and that we're only + + align:start position:0% +more General and that we're only + + + align:start position:0% +more General and that we're only +assuming that it's going to be closed + + align:start position:0% +assuming that it's going to be closed + + + align:start position:0% +assuming that it's going to be closed +and so we're assuming that every finite + + align:start position:0% +and so we're assuming that every finite + + + align:start position:0% +and so we're assuming that every finite +subcollection has non-empty intersection + + align:start position:0% + + + + align:start position:0% + +and so we're going to show is that in + + align:start position:0% +and so we're going to show is that in + + + align:start position:0% +and so we're going to show is that in +fact there's a relationship between the + + align:start position:0% +fact there's a relationship between the + + + align:start position:0% +fact there's a relationship between the +finite intersection property + + align:start position:0% +finite intersection property + + + align:start position:0% +finite intersection property +and topologically and sequentially + + align:start position:0% +and topologically and sequentially + + + align:start position:0% +and topologically and sequentially +compact that's going to be a huge + + align:start position:0% +compact that's going to be a huge + + + align:start position:0% +compact that's going to be a huge +theorem for today it's going to take a + + align:start position:0% +theorem for today it's going to take a + + + align:start position:0% +theorem for today it's going to take a +little bit to prove + + align:start position:0% +little bit to prove + + + align:start position:0% +little bit to prove +but will be deeply powerful once we're + + align:start position:0% +but will be deeply powerful once we're + + + align:start position:0% +but will be deeply powerful once we're +done + + align:start position:0% + + + + align:start position:0% + +our theorem + + align:start position:0% +our theorem + + + align:start position:0% +our theorem +is that the following are equivalent + + align:start position:0% + + + + align:start position:0% + +the following are equivalent which I'll + + align:start position:0% +the following are equivalent which I'll + + + align:start position:0% +the following are equivalent which I'll +write out more fully in case you haven't + + align:start position:0% +write out more fully in case you haven't + + + align:start position:0% +write out more fully in case you haven't +seen this abbreviation before + + align:start position:0% + + + + align:start position:0% + +on a metric Space X + + align:start position:0% + + + + align:start position:0% + +one + + align:start position:0% +one + + + align:start position:0% +one +X is + + align:start position:0% +X is + + + align:start position:0% +X is +topologically compact + + align:start position:0% + + + + align:start position:0% + +topologically + + align:start position:0% + + + + align:start position:0% + +two + + align:start position:0% +two + + + align:start position:0% +two +X is sequentially compact + + align:start position:0% + + + + align:start position:0% + +which makes sense we've already shown + + align:start position:0% +which makes sense we've already shown + + + align:start position:0% +which makes sense we've already shown +this implication + + align:start position:0% +this implication + + + align:start position:0% +this implication +but we're going to show two more + + align:start position:0% +but we're going to show two more + + + align:start position:0% +but we're going to show two more +properties right now + + align:start position:0% +properties right now + + + align:start position:0% +properties right now +three + + align:start position:0% +three + + + align:start position:0% +three +X is totally bounded + + align:start position:0% + + + + align:start position:0% + +which you've already shown sequentially + + align:start position:0% +which you've already shown sequentially + + + align:start position:0% +which you've already shown sequentially +compact implies totally bounded but + + align:start position:0% +compact implies totally bounded but + + + align:start position:0% +compact implies totally bounded but +there's one more thing we need to + + align:start position:0% +there's one more thing we need to + + + align:start position:0% +there's one more thing we need to +include + + align:start position:0% +include + + + align:start position:0% +include +we need to include that is koshy + + align:start position:0% +we need to include that is koshy + + + align:start position:0% +we need to include that is koshy +complete + + align:start position:0% + + + + align:start position:0% + +and finally our fourth property + + align:start position:0% +and finally our fourth property + + + align:start position:0% +and finally our fourth property +is going to be the following which all + + align:start position:0% +is going to be the following which all + + + align:start position:0% +is going to be the following which all +state out clearly because it's one of + + align:start position:0% +state out clearly because it's one of + + + align:start position:0% +state out clearly because it's one of +the more confusing ones + + align:start position:0% + + + + align:start position:0% + +every collection + + align:start position:0% + + + + align:start position:0% + +of closed sets + + align:start position:0% + + + + align:start position:0% + +of close-up sets of x + + align:start position:0% + + + + align:start position:0% + +with the finite intersection property + + align:start position:0% + + + + align:start position:0% + +has non-empty intersection + + align:start position:0% + + + + align:start position:0% + +here the difference is that we know that + + align:start position:0% +here the difference is that we know that + + + align:start position:0% +here the difference is that we know that +every finite subcollection has non-empty + + align:start position:0% +every finite subcollection has non-empty + + + align:start position:0% +every finite subcollection has non-empty +intersection but what this theorem is + + align:start position:0% +intersection but what this theorem is + + + align:start position:0% +intersection but what this theorem is +telling you is that the intersection of + + align:start position:0% +telling you is that the intersection of + + + align:start position:0% +telling you is that the intersection of +all of the closed subsets if they have + + align:start position:0% +all of the closed subsets if they have + + + align:start position:0% +all of the closed subsets if they have +the final intersection property is also + + align:start position:0% +the final intersection property is also + + + align:start position:0% +the final intersection property is also +going to be non-empty + + align:start position:0% + + + + align:start position:0% + +now what we're going to do is show that + + align:start position:0% +now what we're going to do is show that + + + align:start position:0% +now what we're going to do is show that +one is true if and only if four is true + + align:start position:0% +one is true if and only if four is true + + + align:start position:0% +one is true if and only if four is true +we've all already showed let me write + + align:start position:0% +we've all already showed let me write + + + align:start position:0% +we've all already showed let me write +this summer fully we've already shown + + align:start position:0% +this summer fully we've already shown + + + align:start position:0% +this summer fully we've already shown +that one is true if and only if two is + + align:start position:0% +that one is true if and only if two is + + + align:start position:0% +that one is true if and only if two is +true + + align:start position:0% +true + + + align:start position:0% +true +what we're now going to do is show that + + align:start position:0% +what we're now going to do is show that + + + align:start position:0% +what we're now going to do is show that +one is true if and only if 4 is true + + align:start position:0% +one is true if and only if 4 is true + + + align:start position:0% +one is true if and only if 4 is true +and then show + + align:start position:0% +and then show + + + align:start position:0% +and then show +that 2 is true if and only a 3 is true + + align:start position:0% +that 2 is true if and only a 3 is true + + + align:start position:0% +that 2 is true if and only a 3 is true +because we've already shown sequentially + + align:start position:0% +because we've already shown sequentially + + + align:start position:0% +because we've already shown sequentially +compact implies totally bounded so we + + align:start position:0% +compact implies totally bounded so we + + + align:start position:0% +compact implies totally bounded so we +would just have to show koshy + + align:start position:0% +would just have to show koshy + + + align:start position:0% +would just have to show koshy +completeness + + align:start position:0% +completeness + + + align:start position:0% +completeness +and then that's going to be the end of + + align:start position:0% +and then that's going to be the end of + + + align:start position:0% +and then that's going to be the end of +today we're going to show these four + + align:start position:0% +today we're going to show these four + + + align:start position:0% +today we're going to show these four +properties of compact sets and then + + align:start position:0% +properties of compact sets and then + + + align:start position:0% +properties of compact sets and then +we're going to end today's discussion + + align:start position:0% + + + + align:start position:0% + +so let's start with showing that one is + + align:start position:0% +so let's start with showing that one is + + + align:start position:0% +so let's start with showing that one is +true implies 4 is true + + align:start position:0% + + + + align:start position:0% + +so the proof is going to start with + + align:start position:0% +so the proof is going to start with + + + align:start position:0% +so the proof is going to start with +finding or supposing for the sake of + + align:start position:0% +finding or supposing for the sake of + + + align:start position:0% +finding or supposing for the sake of +contradiction there exists a collection + + align:start position:0% +contradiction there exists a collection + + + align:start position:0% +contradiction there exists a collection +of closed sets with the final + + align:start position:0% +of closed sets with the final + + + align:start position:0% +of closed sets with the final +intersection property but with empty + + align:start position:0% +intersection property but with empty + + + align:start position:0% +intersection property but with empty +intersection so suppose + + align:start position:0% + + + + align:start position:0% + +there exists + + align:start position:0% +there exists + + + align:start position:0% +there exists +c i + + align:start position:0% +c i + + + align:start position:0% +c i +equals 1 to Infinity + + align:start position:0% +equals 1 to Infinity + + + align:start position:0% +equals 1 to Infinity +closed + + align:start position:0% + + + + align:start position:0% + +with + + align:start position:0% +with + + + align:start position:0% +with +the finite + + align:start position:0% +the finite + + + align:start position:0% +the finite +intersection property + + align:start position:0% +intersection property + + + align:start position:0% +intersection property +I.E intersection of finite sub + + align:start position:0% +I.E intersection of finite sub + + + align:start position:0% +I.E intersection of finite sub +collections is going to be non-empty + + align:start position:0% +collections is going to be non-empty + + + align:start position:0% +collections is going to be non-empty +and + + align:start position:0% +and + + + align:start position:0% +and +uh + + align:start position:0% +uh + + + align:start position:0% +uh +and the intersection of all the CIS is + + align:start position:0% +and the intersection of all the CIS is + + + align:start position:0% +and the intersection of all the CIS is +that's going to be our assumption for + + align:start position:0% +that's going to be our assumption for + + + align:start position:0% +that's going to be our assumption for +contradiction + + align:start position:0% +contradiction + + + align:start position:0% +contradiction +well knowing that the intersection of + + align:start position:0% +well knowing that the intersection of + + + align:start position:0% +well knowing that the intersection of +these cosets is going to be empty what + + align:start position:0% +these cosets is going to be empty what + + + align:start position:0% +these cosets is going to be empty what +do we know about the complements + + align:start position:0% +do we know about the complements + + + align:start position:0% +do we know about the complements +well then we know that X which is the + + align:start position:0% +well then we know that X which is the + + + align:start position:0% +well then we know that X which is the +complement of the empty set is going to + + align:start position:0% +complement of the empty set is going to + + + align:start position:0% +complement of the empty set is going to +be the complement of the intersection of + + align:start position:0% +be the complement of the intersection of + + + align:start position:0% +be the complement of the intersection of +CIS + + align:start position:0% +CIS + + + align:start position:0% +CIS +but then we know by De Morgan's laws + + align:start position:0% +but then we know by De Morgan's laws + + + align:start position:0% +but then we know by De Morgan's laws +which we introduced on the second day in + + align:start position:0% +which we introduced on the second day in + + + align:start position:0% +which we introduced on the second day in +general theory + + align:start position:0% +general theory + + + align:start position:0% +general theory +it's going to be the Union + + align:start position:0% +it's going to be the Union + + + align:start position:0% +it's going to be the Union +of the complements of Ci's from I equals + + align:start position:0% +of the complements of Ci's from I equals + + + align:start position:0% +of the complements of Ci's from I equals +1 to Infinity + + align:start position:0% +1 to Infinity + + + align:start position:0% +1 to Infinity +what do we know that + + align:start position:0% +what do we know that + + + align:start position:0% +what do we know that +was a complement of a closed set is + + align:start position:0% +was a complement of a closed set is + + + align:start position:0% +was a complement of a closed set is +going to be open so what we've gone from + + align:start position:0% +going to be open so what we've gone from + + + align:start position:0% +going to be open so what we've gone from +is this collection of closed sets to an + + align:start position:0% +is this collection of closed sets to an + + + align:start position:0% +is this collection of closed sets to an +open cover of x + + align:start position:0% +open cover of x + + + align:start position:0% +open cover of x +therefore + + align:start position:0% + + + + align:start position:0% + +there exists a finite subcover + + align:start position:0% + + + + align:start position:0% + +given by let's say the union from I + + align:start position:0% +given by let's say the union from I + + + align:start position:0% +given by let's say the union from I +equals 1 to K of C i complement + + align:start position:0% + + + + align:start position:0% + +I know what we're going to show is then + + align:start position:0% +I know what we're going to show is then + + + align:start position:0% +I know what we're going to show is then +that it fails to have the final + + align:start position:0% +that it fails to have the final + + + align:start position:0% +that it fails to have the final +intersection property + + align:start position:0% +intersection property + + + align:start position:0% +intersection property +so notice then + + align:start position:0% +so notice then + + + align:start position:0% +so notice then +that the intersection + + align:start position:0% +that the intersection + + + align:start position:0% +that the intersection +of CI from I equals + + align:start position:0% +of CI from I equals + + + align:start position:0% +of CI from I equals +1 to K + + align:start position:0% +1 to K + + + align:start position:0% +1 to K +is going to be the same as + + align:start position:0% +is going to be the same as + + + align:start position:0% +is going to be the same as +the union of the complements + + align:start position:0% +the union of the complements + + + align:start position:0% +the union of the complements +from I equals 1 to K + + align:start position:0% +from I equals 1 to K + + + align:start position:0% +from I equals 1 to K +which we know is X + + align:start position:0% +which we know is X + + + align:start position:0% +which we know is X +so what this tells us is that the + + align:start position:0% +so what this tells us is that the + + + align:start position:0% +so what this tells us is that the +complement of this + + align:start position:0% +complement of this + + + align:start position:0% +complement of this +sorry that's not what I meant to say + + align:start position:0% + + + + align:start position:0% + +let me reiterate + + align:start position:0% +let me reiterate + + + align:start position:0% +let me reiterate +what we know then is that + + align:start position:0% +what we know then is that + + + align:start position:0% +what we know then is that +uh + + align:start position:0% +uh + + + align:start position:0% +uh +X yeah X is equal to + + align:start position:0% +X yeah X is equal to + + + align:start position:0% +X yeah X is equal to +the union of c i complement from I + + align:start position:0% +the union of c i complement from I + + + align:start position:0% +the union of c i complement from I +equals one + + align:start position:0% +equals one + + + align:start position:0% +equals one +to K which is of course equal to the + + align:start position:0% +to K which is of course equal to the + + + align:start position:0% +to K which is of course equal to the +intersection + + align:start position:0% +intersection + + + align:start position:0% +intersection +from n equals one + + align:start position:0% +from n equals one + + + align:start position:0% +from n equals one +okay see from I equals one to K + + align:start position:0% +okay see from I equals one to K + + + align:start position:0% +okay see from I equals one to K +c i + + align:start position:0% + + + + align:start position:0% + +complement so we've gone from the union + + align:start position:0% +complement so we've gone from the union + + + align:start position:0% +complement so we've gone from the union +of the complements to the complement of + + align:start position:0% +of the complements to the complement of + + + align:start position:0% +of the complements to the complement of +the intersection + + align:start position:0% +the intersection + + + align:start position:0% +the intersection +and then this implies + + align:start position:0% +and then this implies + + + align:start position:0% +and then this implies +that the intersection from I equals 1 to + + align:start position:0% +that the intersection from I equals 1 to + + + align:start position:0% +that the intersection from I equals 1 to +K of CI must be the empty set which is a + + align:start position:0% +K of CI must be the empty set which is a + + + align:start position:0% +K of CI must be the empty set which is a +contradiction because we're assuming + + align:start position:0% +contradiction because we're assuming + + + align:start position:0% +contradiction because we're assuming +that it has the final intersection + + align:start position:0% +that it has the final intersection + + + align:start position:0% +that it has the final intersection +property which again means that every + + align:start position:0% +property which again means that every + + + align:start position:0% +property which again means that every +finite subcollection has a non-empty + + align:start position:0% +finite subcollection has a non-empty + + + align:start position:0% +finite subcollection has a non-empty +intersection + + align:start position:0% +intersection + + + align:start position:0% +intersection +so this is our contradiction and we've + + align:start position:0% +so this is our contradiction and we've + + + align:start position:0% +so this is our contradiction and we've +shown that topologically compact implies + + align:start position:0% +shown that topologically compact implies + + + align:start position:0% +shown that topologically compact implies +that every collection of closed sets has + + align:start position:0% +that every collection of closed sets has + + + align:start position:0% +that every collection of closed sets has +with the final intersection property has + + align:start position:0% +with the final intersection property has + + + align:start position:0% +with the final intersection property has +non-empty intersection + + align:start position:0% + + + + align:start position:0% + +the proof of the other direction is + + align:start position:0% +the proof of the other direction is + + + align:start position:0% +the proof of the other direction is +going to be very similar + + align:start position:0% +going to be very similar + + + align:start position:0% +going to be very similar +we're going to show that it's + + align:start position:0% +we're going to show that it's + + + align:start position:0% +we're going to show that it's +topologically compact given property + + align:start position:0% +topologically compact given property + + + align:start position:0% +topologically compact given property +four + + align:start position:0% +four + + + align:start position:0% +four +so we're going to show that four + + align:start position:0% +so we're going to show that four + + + align:start position:0% +so we're going to show that four +implies one + + align:start position:0% + + + + align:start position:0% + +suppose + + align:start position:0% + + + + align:start position:0% + +the uis + + align:start position:0% + + + + align:start position:0% + +are an open cover + + align:start position:0% +are an open cover + + + align:start position:0% +are an open cover +of x + + align:start position:0% + + + + align:start position:0% + +when we want to go from then + + align:start position:0% +when we want to go from then + + + align:start position:0% +when we want to go from then +is we want to use this to find + + align:start position:0% +is we want to use this to find + + + align:start position:0% +is we want to use this to find +information about closed sets so that we + + align:start position:0% +information about closed sets so that we + + + align:start position:0% +information about closed sets so that we +can apply property for Well what we'll + + align:start position:0% +can apply property for Well what we'll + + + align:start position:0% +can apply property for Well what we'll +do is let UI complement + + align:start position:0% +do is let UI complement + + + align:start position:0% +do is let UI complement +TI which are going to be closed + + align:start position:0% +TI which are going to be closed + + + align:start position:0% +TI which are going to be closed +how do you know that they're closed + + align:start position:0% +how do you know that they're closed + + + align:start position:0% +how do you know that they're closed +because the complement is going to be + + align:start position:0% +because the complement is going to be + + + align:start position:0% +because the complement is going to be +the uis which are open so that implies + + align:start position:0% +the uis which are open so that implies + + + align:start position:0% +the uis which are open so that implies +that it's closed + + align:start position:0% +that it's closed + + + align:start position:0% +that it's closed +and so we're going to note or what we're + + align:start position:0% +and so we're going to note or what we're + + + align:start position:0% +and so we're going to note or what we're +going to show is that the Ci's have + + align:start position:0% +going to show is that the Ci's have + + + align:start position:0% +going to show is that the Ci's have +finite intersection + + align:start position:0% +finite intersection + + + align:start position:0% +finite intersection +so how's the final intersection property + + align:start position:0% +so how's the final intersection property + + + align:start position:0% +so how's the final intersection property +well notice then + + align:start position:0% + + + + align:start position:0% + +to + + align:start position:0% + + + + align:start position:0% + +assume for the sake of contradiction + + align:start position:0% +assume for the sake of contradiction + + + align:start position:0% +assume for the sake of contradiction +that they don't have the fine + + align:start position:0% +that they don't have the fine + + + align:start position:0% +that they don't have the fine +intersection property + + align:start position:0% +intersection property + + + align:start position:0% +intersection property +for the sake of contradiction + + align:start position:0% +for the sake of contradiction + + + align:start position:0% +for the sake of contradiction +that the intersection of ci1 + + align:start position:0% +that the intersection of ci1 + + + align:start position:0% +that the intersection of ci1 +c i k is empty + + align:start position:0% +c i k is empty + + + align:start position:0% +c i k is empty +I.E it doesn't have the final + + align:start position:0% +I.E it doesn't have the final + + + align:start position:0% +I.E it doesn't have the final +intersection property + + align:start position:0% +intersection property + + + align:start position:0% +intersection property +well then + + align:start position:0% +well then + + + align:start position:0% +well then +what we'll have is that the union from I + + align:start position:0% +what we'll have is that the union from I + + + align:start position:0% +what we'll have is that the union from I +equals one + + align:start position:0% +equals one + + + align:start position:0% +equals one +to + + align:start position:0% +to + + + align:start position:0% +to +k + + align:start position:0% +k + + + align:start position:0% +k +of the uis + + align:start position:0% +of the uis + + + align:start position:0% +of the uis +is equal to the intersection of the CI K + + align:start position:0% +is equal to the intersection of the CI K + + + align:start position:0% +is equal to the intersection of the CI K +cim from n equals 1 to K complement + + align:start position:0% +cim from n equals 1 to K complement + + + align:start position:0% +cim from n equals 1 to K complement +complement + + align:start position:0% + + + + align:start position:0% + +which is of course then the complement + + align:start position:0% +which is of course then the complement + + + align:start position:0% +which is of course then the complement +of the intersection of the cosets which + + align:start position:0% +of the intersection of the cosets which + + + align:start position:0% +of the intersection of the cosets which +is X + + align:start position:0% + + + + align:start position:0% + +um do I want to read to this proof + + align:start position:0% +um do I want to read to this proof + + + align:start position:0% +um do I want to read to this proof +I will redo this proof I want to rewrite + + align:start position:0% +I will redo this proof I want to rewrite + + + align:start position:0% +I will redo this proof I want to rewrite +this out more carefully because we have + + align:start position:0% +this out more carefully because we have + + + align:start position:0% +this out more carefully because we have +two nested + + align:start position:0% + + + + align:start position:0% + +contradictions so firstly + + align:start position:0% +contradictions so firstly + + + align:start position:0% +contradictions so firstly +assume + + align:start position:0% + + + + align:start position:0% + +for the sake of contradiction + + align:start position:0% +for the sake of contradiction + + + align:start position:0% +for the sake of contradiction +that + + align:start position:0% +that + + + align:start position:0% +that +there is no finite subcover of the uis + + align:start position:0% + + + + align:start position:0% + +finite subcover + + align:start position:0% + + + + align:start position:0% + +of the uis + + align:start position:0% + + + + align:start position:0% + +I.E uh we're assuming for the sake of + + align:start position:0% +I.E uh we're assuming for the sake of + + + align:start position:0% +I.E uh we're assuming for the sake of +contradiction that X is not + + align:start position:0% +contradiction that X is not + + + align:start position:0% +contradiction that X is not +topologically compact + + align:start position:0% +topologically compact + + + align:start position:0% +topologically compact +furthermore we're going to assume + + align:start position:0% +furthermore we're going to assume + + + align:start position:0% +furthermore we're going to assume +for the sake of contradiction + + align:start position:0% + + + + align:start position:0% + +do you guys have or don't have the final + + align:start position:0% +do you guys have or don't have the final + + + align:start position:0% +do you guys have or don't have the final +intersection property + + align:start position:0% +intersection property + + + align:start position:0% +intersection property +therefore + + align:start position:0% + + + + align:start position:0% + +because we want to show that they do + + align:start position:0% +because we want to show that they do + + + align:start position:0% +because we want to show that they do +have the final intersection property + + align:start position:0% +have the final intersection property + + + align:start position:0% +have the final intersection property +so the intersection from n equals 1 to K + + align:start position:0% +so the intersection from n equals 1 to K + + + align:start position:0% +so the intersection from n equals 1 to K +of C i n + + align:start position:0% +of C i n + + + align:start position:0% +of C i n +is empty that's what we're going to + + align:start position:0% +is empty that's what we're going to + + + align:start position:0% +is empty that's what we're going to +assume well then what do we know we know + + align:start position:0% +assume well then what do we know we know + + + align:start position:0% +assume well then what do we know we know +then that the union of the uis uin from + + align:start position:0% +then that the union of the uis uin from + + + align:start position:0% +then that the union of the uis uin from +n equals 1 to Infinity not Infinity to K + + align:start position:0% +n equals 1 to Infinity not Infinity to K + + + align:start position:0% +n equals 1 to Infinity not Infinity to K +intersection of the complements + + align:start position:0% +intersection of the complements + + + align:start position:0% +intersection of the complements +complement from + + align:start position:0% +complement from + + + align:start position:0% +complement from +n equals 1 to K + + align:start position:0% +n equals 1 to K + + + align:start position:0% +n equals 1 to K +but then this is going to be all of X + + align:start position:0% +but then this is going to be all of X + + + align:start position:0% +but then this is going to be all of X +right because it's a complement of the + + align:start position:0% +right because it's a complement of the + + + align:start position:0% +right because it's a complement of the +empty set + + align:start position:0% +empty set + + + align:start position:0% +empty set +and that's a contradiction because we're + + align:start position:0% +and that's a contradiction because we're + + + align:start position:0% +and that's a contradiction because we're +assuming that there's no finite subcover + + align:start position:0% +assuming that there's no finite subcover + + + align:start position:0% +assuming that there's no finite subcover +of the uis + + align:start position:0% +of the uis + + + align:start position:0% +of the uis +so what we know then + + align:start position:0% + + + + align:start position:0% + +is that the Ci's + + align:start position:0% + + + + align:start position:0% + +have the finite intersection property + + align:start position:0% + + + + align:start position:0% + +I.E the intersection of all of the CIS + + align:start position:0% +I.E the intersection of all of the CIS + + + align:start position:0% +I.E the intersection of all of the CIS +from I equals 1 to Infinity + + align:start position:0% +from I equals 1 to Infinity + + + align:start position:0% +from I equals 1 to Infinity +is non-empty + + align:start position:0% +is non-empty + + + align:start position:0% +is non-empty +so what do we know we know then that the + + align:start position:0% +so what do we know we know then that the + + + align:start position:0% +so what do we know we know then that the +complement of these is going to be not + + align:start position:0% +complement of these is going to be not + + + align:start position:0% +complement of these is going to be not +all of X so we know that X + + align:start position:0% +all of X so we know that X + + + align:start position:0% +all of X so we know that X +which is the complement of the empty set + + align:start position:0% +which is the complement of the empty set + + + align:start position:0% +which is the complement of the empty set +is not going to be equal to + + align:start position:0% +is not going to be equal to + + + align:start position:0% +is not going to be equal to +the complement of the intersection of + + align:start position:0% +the complement of the intersection of + + + align:start position:0% +the complement of the intersection of +the CIS + + align:start position:0% + + + + align:start position:0% + +I equals one + + align:start position:0% +I equals one + + + align:start position:0% +I equals one +to Infinity which is of course the union + + align:start position:0% +to Infinity which is of course the union + + + align:start position:0% +to Infinity which is of course the union +of the uis + + align:start position:0% + + + + align:start position:0% + +but this is a contradiction because + + align:start position:0% +but this is a contradiction because + + + align:start position:0% +but this is a contradiction because +we've assumed from the very beginning + + align:start position:0% +we've assumed from the very beginning + + + align:start position:0% +we've assumed from the very beginning +that the uis are an open cover of X so + + align:start position:0% +that the uis are an open cover of X so + + + align:start position:0% +that the uis are an open cover of X so +what we've shown is that our open cover + + align:start position:0% +what we've shown is that our open cover + + + align:start position:0% +what we've shown is that our open cover +is not in fact an open cover which is + + align:start position:0% +is not in fact an open cover which is + + + align:start position:0% +is not in fact an open cover which is +our contradiction + + align:start position:0% +our contradiction + + + align:start position:0% +our contradiction +so we've shown so far + + align:start position:0% + + + + align:start position:0% + +that one implies four which implies one + + align:start position:0% +that one implies four which implies one + + + align:start position:0% +that one implies four which implies one +and one + + align:start position:0% +and one + + + align:start position:0% +and one +implies two + + align:start position:0% +implies two + + + align:start position:0% +implies two +which implies one so now what we need to + + align:start position:0% +which implies one so now what we need to + + + align:start position:0% +which implies one so now what we need to +show is that 2 is the same as 3. I.E + + align:start position:0% +show is that 2 is the same as 3. I.E + + + align:start position:0% +show is that 2 is the same as 3. I.E +sequentially compact is the same as + + align:start position:0% +sequentially compact is the same as + + + align:start position:0% +sequentially compact is the same as +totally bounded and cushy complete + + align:start position:0% +totally bounded and cushy complete + + + align:start position:0% +totally bounded and cushy complete +now one of these directions has already + + align:start position:0% +now one of these directions has already + + + align:start position:0% +now one of these directions has already +been done for us we've already shown + + align:start position:0% +been done for us we've already shown + + + align:start position:0% +been done for us we've already shown +that totally bounded is a comp is a + + align:start position:0% +that totally bounded is a comp is a + + + align:start position:0% +that totally bounded is a comp is a +consequence of sequentially compact but + + align:start position:0% +consequence of sequentially compact but + + + align:start position:0% +consequence of sequentially compact but +we now need to show is that it's koshy + + align:start position:0% +we now need to show is that it's koshy + + + align:start position:0% +we now need to show is that it's koshy +complete + + align:start position:0% +complete + + + align:start position:0% +complete +so we're going to first show that 2 + + align:start position:0% +so we're going to first show that 2 + + + align:start position:0% +so we're going to first show that 2 +implies 3. + + align:start position:0% +implies 3. + + + align:start position:0% +implies 3. +okay + + align:start position:0% + + + + align:start position:0% + +so let + + align:start position:0% +so let + + + align:start position:0% +so let +x i + + align:start position:0% + + + + align:start position:0% + +be a koshy sequence of x + + align:start position:0% + + + + align:start position:0% + +i e + + align:start position:0% +i e + + + align:start position:0% +i e +for all Epsilon bigger than zero there + + align:start position:0% +for all Epsilon bigger than zero there + + + align:start position:0% +for all Epsilon bigger than zero there +exists an n in the natural numbers + + align:start position:0% +exists an n in the natural numbers + + + align:start position:0% +exists an n in the natural numbers +such that for all and an M bigger than + + align:start position:0% +such that for all and an M bigger than + + + align:start position:0% +such that for all and an M bigger than +or equal to n + + align:start position:0% +or equal to n + + + align:start position:0% +or equal to n +the distance between x n and XM + + align:start position:0% +the distance between x n and XM + + + align:start position:0% +the distance between x n and XM +is less than Epsilon we're going to use + + align:start position:0% +is less than Epsilon we're going to use + + + align:start position:0% +is less than Epsilon we're going to use +this to our advantage + + align:start position:0% +this to our advantage + + + align:start position:0% +this to our advantage +so furthermore what we know is that by + + align:start position:0% +so furthermore what we know is that by + + + align:start position:0% +so furthermore what we know is that by +sequential compactness there's going to + + align:start position:0% +sequential compactness there's going to + + + align:start position:0% +sequential compactness there's going to +exist a convergent subsequence of the X + + align:start position:0% +exist a convergent subsequence of the X + + + align:start position:0% +exist a convergent subsequence of the X +I's + + align:start position:0% + + + + align:start position:0% + +and let's say it converges to X + + align:start position:0% + + + + align:start position:0% + +and what we're going to show then is + + align:start position:0% +and what we're going to show then is + + + align:start position:0% +and what we're going to show then is +that in fact X I will converge to X + + align:start position:0% +that in fact X I will converge to X + + + align:start position:0% +that in fact X I will converge to X +we're going to show that the limit point + + align:start position:0% +we're going to show that the limit point + + + align:start position:0% +we're going to show that the limit point +of the Koji sequence is in fact going to + + align:start position:0% +of the Koji sequence is in fact going to + + + align:start position:0% +of the Koji sequence is in fact going to +be in our metric space + + align:start position:0% +be in our metric space + + + align:start position:0% +be in our metric space +to do that let me move to actually I can + + align:start position:0% +to do that let me move to actually I can + + + align:start position:0% +to do that let me move to actually I can +fit this in here + + align:start position:0% +fit this in here + + + align:start position:0% +fit this in here +notice then + + align:start position:0% +notice then + + + align:start position:0% +notice then +for all n + + align:start position:0% +for all n + + + align:start position:0% +for all n +bigger than or equal to n for all n K + + align:start position:0% +bigger than or equal to n for all n K + + + align:start position:0% +bigger than or equal to n for all n K +and N bigger than or equal to n so look + + align:start position:0% +and N bigger than or equal to n so look + + + align:start position:0% +and N bigger than or equal to n so look +at the distance from X to xn and this + + align:start position:0% +at the distance from X to xn and this + + + align:start position:0% +at the distance from X to xn and this +will be less than or equal to the + + align:start position:0% +will be less than or equal to the + + + align:start position:0% +will be less than or equal to the +distance from X to X and K + + align:start position:0% + + + + align:start position:0% + +plus the distance from X and K + + align:start position:0% +plus the distance from X and K + + + align:start position:0% +plus the distance from X and K +to x n + + align:start position:0% +to x n + + + align:start position:0% +to x n +and we know that this term is going to + + align:start position:0% +and we know that this term is going to + + + align:start position:0% +and we know that this term is going to +be less than Epsilon over 2. + + align:start position:0% +be less than Epsilon over 2. + + + align:start position:0% +be less than Epsilon over 2. +or sorry we should assume Epsilon over 2 + + align:start position:0% +or sorry we should assume Epsilon over 2 + + + align:start position:0% +or sorry we should assume Epsilon over 2 +from the beginning + + align:start position:0% +from the beginning + + + align:start position:0% +from the beginning +but furthermore we know that X and K + + align:start position:0% +but furthermore we know that X and K + + + align:start position:0% +but furthermore we know that X and K +converges to X so we can assume that + + align:start position:0% +converges to X so we can assume that + + + align:start position:0% +converges to X so we can assume that +this one is less than Epsilon over 2 + + align:start position:0% +this one is less than Epsilon over 2 + + + align:start position:0% +this one is less than Epsilon over 2 +which is Epsilon so we've shown that x n + + align:start position:0% +which is Epsilon so we've shown that x n + + + align:start position:0% +which is Epsilon so we've shown that x n +is so what we've shown + + align:start position:0% +is so what we've shown + + + align:start position:0% +is so what we've shown +therefore is that X I will converge to X + + align:start position:0% +therefore is that X I will converge to X + + + align:start position:0% +therefore is that X I will converge to X +and so we've shown that every cauchy + + align:start position:0% +and so we've shown that every cauchy + + + align:start position:0% +and so we've shown that every cauchy +sequence has a conver is convergent so + + align:start position:0% +sequence has a conver is convergent so + + + align:start position:0% +sequence has a conver is convergent so +we've shown cushy completeness + + align:start position:0% +we've shown cushy completeness + + + align:start position:0% +we've shown cushy completeness +which is what we wanted to show we + + align:start position:0% +which is what we wanted to show we + + + align:start position:0% +which is what we wanted to show we +wanted to show that sequential + + align:start position:0% +wanted to show that sequential + + + align:start position:0% +wanted to show that sequential +compactness was the same as totally + + align:start position:0% +compactness was the same as totally + + + align:start position:0% +compactness was the same as totally +bounded and koshy complete which + + align:start position:0% +bounded and koshy complete which + + + align:start position:0% +bounded and koshy complete which +concludes the first part of our proof + + align:start position:0% + + + + align:start position:0% + +the second part the second direction is + + align:start position:0% +the second part the second direction is + + + align:start position:0% +the second part the second direction is +going to be quite a bit harder because + + align:start position:0% +going to be quite a bit harder because + + + align:start position:0% +going to be quite a bit harder because +we want to show that every sequence has + + align:start position:0% +we want to show that every sequence has + + + align:start position:0% +we want to show that every sequence has +a convergent subsequence assuming + + align:start position:0% +a convergent subsequence assuming + + + align:start position:0% +a convergent subsequence assuming +totally bounded in koshy complete which + + align:start position:0% +totally bounded in koshy complete which + + + align:start position:0% +totally bounded in koshy complete which +is going to require quite a bit of work + + align:start position:0% +is going to require quite a bit of work + + + align:start position:0% +is going to require quite a bit of work +um or at least quite a bit of mental + + align:start position:0% +um or at least quite a bit of mental + + + align:start position:0% +um or at least quite a bit of mental +work + + align:start position:0% +work + + + align:start position:0% +work +even if on the chalkboard it's not so + + align:start position:0% +even if on the chalkboard it's not so + + + align:start position:0% +even if on the chalkboard it's not so +much + + align:start position:0% +much + + + align:start position:0% +much +it's a little bit confusing how we go + + align:start position:0% +it's a little bit confusing how we go + + + align:start position:0% +it's a little bit confusing how we go +from + + align:start position:0% +from + + + align:start position:0% +from +totally bounded and koshy complete + + align:start position:0% +totally bounded and koshy complete + + + align:start position:0% +totally bounded and koshy complete +to a convergent subsequence + + align:start position:0% +to a convergent subsequence + + + align:start position:0% +to a convergent subsequence +okay we now want to show that property 4 + + align:start position:0% +okay we now want to show that property 4 + + + align:start position:0% +okay we now want to show that property 4 +implies property one + + align:start position:0% +implies property one + + + align:start position:0% +implies property one +and this will conclude our proof + + align:start position:0% + + + + align:start position:0% + +okay how are we going to do this well + + align:start position:0% +okay how are we going to do this well + + + align:start position:0% +okay how are we going to do this well +we're going to assume that + + align:start position:0% + + + + align:start position:0% + +X is totally bounded + + align:start position:0% + + + + align:start position:0% + +and cushy complete + + align:start position:0% + + + + align:start position:0% + +and we want to show sequential + + align:start position:0% +and we want to show sequential + + + align:start position:0% +and we want to show sequential +compactness + + align:start position:0% +compactness + + + align:start position:0% +compactness +how do we do that well we're going to + + align:start position:0% +how do we do that well we're going to + + + align:start position:0% +how do we do that well we're going to +start with a arbitrary sequence in x + + align:start position:0% +start with a arbitrary sequence in x + + + align:start position:0% +start with a arbitrary sequence in x +so let + + align:start position:0% +so let + + + align:start position:0% +so let +x i + + align:start position:0% +x i + + + align:start position:0% +x i +be an arbitrary + + align:start position:0% +be an arbitrary + + + align:start position:0% +be an arbitrary +sequence in x + + align:start position:0% +sequence in x + + + align:start position:0% +sequence in x +and we want to show that there exists a + + align:start position:0% +and we want to show that there exists a + + + align:start position:0% +and we want to show that there exists a +convergent subsequence which is going to + + align:start position:0% +convergent subsequence which is going to + + + align:start position:0% +convergent subsequence which is going to +be a little bit difficult + + align:start position:0% +be a little bit difficult + + + align:start position:0% +be a little bit difficult +okay to do so what we're going to do is + + align:start position:0% +okay to do so what we're going to do is + + + align:start position:0% +okay to do so what we're going to do is +start with totally bounded we're going + + align:start position:0% +start with totally bounded we're going + + + align:start position:0% +start with totally bounded we're going +to note + + align:start position:0% +to note + + + align:start position:0% +to note +that for all n bigger than or equal to + + align:start position:0% +that for all n bigger than or equal to + + + align:start position:0% +that for all n bigger than or equal to +for all and the natural numbers + + align:start position:0% +for all and the natural numbers + + + align:start position:0% +for all and the natural numbers +we have that there exists + + align:start position:0% + + + + align:start position:0% + +there exists finally many y1 or in fact + + align:start position:0% +there exists finally many y1 or in fact + + + align:start position:0% +there exists finally many y1 or in fact +I'll notate this + + align:start position:0% + + + + align:start position:0% + +y n one + + align:start position:0% + + + + align:start position:0% + +through y r of n n + + align:start position:0% +through y r of n n + + + align:start position:0% +through y r of n n +such that + + align:start position:0% + + + + align:start position:0% + +the balls of radius 1 over n + + align:start position:0% + + + + align:start position:0% + +around y + + align:start position:0% +around y + + + align:start position:0% +around y +I of n + + align:start position:0% +I of n + + + align:start position:0% +I of n +we cover X + + align:start position:0% +we cover X + + + align:start position:0% +we cover X +this is our assumption from totally + + align:start position:0% +this is our assumption from totally + + + align:start position:0% +this is our assumption from totally +boundedness here R of n is just a + + align:start position:0% +boundedness here R of n is just a + + + align:start position:0% +boundedness here R of n is just a +function of r uh if it's a function r + + align:start position:0% +function of r uh if it's a function r + + + align:start position:0% +function of r uh if it's a function r +that depends on N because the number of + + align:start position:0% +that depends on N because the number of + + + align:start position:0% +that depends on N because the number of +finally many terms + + align:start position:0% +finally many terms + + + align:start position:0% +finally many terms +um can depend on n + + align:start position:0% +um can depend on n + + + align:start position:0% +um can depend on n +so we in other words we don't know + + align:start position:0% +so we in other words we don't know + + + align:start position:0% +so we in other words we don't know +exactly how many finally many terms we + + align:start position:0% +exactly how many finally many terms we + + + align:start position:0% +exactly how many finally many terms we +have but the more important thing to + + align:start position:0% +have but the more important thing to + + + align:start position:0% +have but the more important thing to +note is that we have finally many of + + align:start position:0% +note is that we have finally many of + + + align:start position:0% +note is that we have finally many of +these for every single n which is our + + align:start position:0% +these for every single n which is our + + + align:start position:0% +these for every single n which is our +sub superscript + + align:start position:0% +sub superscript + + + align:start position:0% +sub superscript +okay + + align:start position:0% +okay + + + align:start position:0% +okay +what are we going to do with this + + align:start position:0% +what are we going to do with this + + + align:start position:0% +what are we going to do with this +well we're going to go from this to + + align:start position:0% +well we're going to go from this to + + + align:start position:0% +well we're going to go from this to +okay we want to go from this to a koshy + + align:start position:0% +okay we want to go from this to a koshy + + + align:start position:0% +okay we want to go from this to a koshy +subsequence of the X I's and once we + + align:start position:0% +subsequence of the X I's and once we + + + align:start position:0% +subsequence of the X I's and once we +know that it's koshy we're going to know + + align:start position:0% +know that it's koshy we're going to know + + + align:start position:0% +know that it's koshy we're going to know +that it's convergent + + align:start position:0% +that it's convergent + + + align:start position:0% +that it's convergent +so + + align:start position:0% +so + + + align:start position:0% +so +to do + + align:start position:0% + + + + align:start position:0% + +we know that there must exist one + + align:start position:0% +we know that there must exist one + + + align:start position:0% +we know that there must exist one +to do + + align:start position:0% + + + + align:start position:0% + +how do I want to see this + + align:start position:0% + + + + align:start position:0% + +uh to do + + align:start position:0% +uh to do + + + align:start position:0% +uh to do +yeah let's let S1 + + align:start position:0% +yeah let's let S1 + + + align:start position:0% +yeah let's let S1 +be the set of these points y1 and + + align:start position:0% +be the set of these points y1 and + + + align:start position:0% +be the set of these points y1 and +through y r of n + + align:start position:0% + + + + align:start position:0% + +what we know is that given that x i is + + align:start position:0% +what we know is that given that x i is + + + align:start position:0% +what we know is that given that x i is +an infinitely long sequence in X that + + align:start position:0% +an infinitely long sequence in X that + + + align:start position:0% +an infinitely long sequence in X that +one of that one of the balls of radius r + + align:start position:0% +one of that one of the balls of radius r + + + align:start position:0% +one of that one of the balls of radius r +or balls of radius one over n around + + align:start position:0% +or balls of radius one over n around + + + align:start position:0% +or balls of radius one over n around +these points + + align:start position:0% + + + + align:start position:0% + +sorry I should call this SN + + align:start position:0% +sorry I should call this SN + + + align:start position:0% +sorry I should call this SN +we know that around the balls of radius + + align:start position:0% +we know that around the balls of radius + + + align:start position:0% +we know that around the balls of radius +1 over n around one of these points has + + align:start position:0% +1 over n around one of these points has + + + align:start position:0% +1 over n around one of these points has +to contain infinitely many of the terms + + align:start position:0% +to contain infinitely many of the terms + + + align:start position:0% +to contain infinitely many of the terms +this is by the pigeonhole principle + + align:start position:0% +this is by the pigeonhole principle + + + align:start position:0% +this is by the pigeonhole principle +so therefore + + align:start position:0% +so therefore + + + align:start position:0% +so therefore +there exists an x i + + align:start position:0% + + + + align:start position:0% + +oh sorry I should say there exists a + + align:start position:0% +oh sorry I should say there exists a + + + align:start position:0% +oh sorry I should say there exists a +ball of radius one + + align:start position:0% +ball of radius one + + + align:start position:0% +ball of radius one +around some y i of one + + align:start position:0% +around some y i of one + + + align:start position:0% +around some y i of one +containing infinitely many + + align:start position:0% + + + + align:start position:0% + +containing + + align:start position:0% +containing + + + align:start position:0% +containing +infinitely many + + align:start position:0% + + + + align:start position:0% + +x i + + align:start position:0% + + + + align:start position:0% + +and what we're going to do is choose our + + align:start position:0% +and what we're going to do is choose our + + + align:start position:0% +and what we're going to do is choose our +first point in our sequence to be one of + + align:start position:0% +first point in our sequence to be one of + + + align:start position:0% +first point in our sequence to be one of +these points + + align:start position:0% +these points + + + align:start position:0% +these points +so let + + align:start position:0% +so let + + + align:start position:0% +so let +Z1 be the first + + align:start position:0% + + + + align:start position:0% + +just out of just just out of assumption + + align:start position:0% +just out of just just out of assumption + + + align:start position:0% +just out of just just out of assumption +and what we're going to do is continue + + align:start position:0% +and what we're going to do is continue + + + align:start position:0% +and what we're going to do is continue +constructing these Eis well we know then + + align:start position:0% +constructing these Eis well we know then + + + align:start position:0% +constructing these Eis well we know then +furthermore is that there exists a ball + + align:start position:0% +furthermore is that there exists a ball + + + align:start position:0% +furthermore is that there exists a ball +of radius one + + align:start position:0% +of radius one + + + align:start position:0% +of radius one +of why I to + + align:start position:0% +of why I to + + + align:start position:0% +of why I to +such that + + align:start position:0% +such that + + + align:start position:0% +such that +sorry one half + + align:start position:0% +sorry one half + + + align:start position:0% +sorry one half +such that the intersection of these two + + align:start position:0% +such that the intersection of these two + + + align:start position:0% +such that the intersection of these two +ball of radius 1 over 2 around y + + align:start position:0% +ball of radius 1 over 2 around y + + + align:start position:0% +ball of radius 1 over 2 around y +I2 + + align:start position:0% +I2 + + + align:start position:0% +I2 +intersection the ball of radius one + + align:start position:0% +intersection the ball of radius one + + + align:start position:0% +intersection the ball of radius one +y j one + + align:start position:0% +y j one + + + align:start position:0% +y j one +has infinitely many + + align:start position:0% +has infinitely many + + + align:start position:0% +has infinitely many +x i + + align:start position:0% + + + + align:start position:0% + +how do we know that this is true + + align:start position:0% +how do we know that this is true + + + align:start position:0% +how do we know that this is true +well we know that infinitely many of + + align:start position:0% +well we know that infinitely many of + + + align:start position:0% +well we know that infinitely many of +them already lie in this ball and so we + + align:start position:0% +them already lie in this ball and so we + + + align:start position:0% +them already lie in this ball and so we +already know if we take the intersection + + align:start position:0% +already know if we take the intersection + + + align:start position:0% +already know if we take the intersection +of this with all the other balls of + + align:start position:0% +of this with all the other balls of + + + align:start position:0% +of this with all the other balls of +radius one half there has to be + + align:start position:0% +radius one half there has to be + + + align:start position:0% +radius one half there has to be +infinitely many there and to see this + + align:start position:0% +infinitely many there and to see this + + + align:start position:0% +infinitely many there and to see this +I'll draw a little bit more of a picture + + align:start position:0% + + + + align:start position:0% + +so here + + align:start position:0% +so here + + + align:start position:0% +so here +is our metrics base X and we start with + + align:start position:0% +is our metrics base X and we start with + + + align:start position:0% +is our metrics base X and we start with +covering it with balls of radius one + + align:start position:0% +covering it with balls of radius one + + + align:start position:0% +covering it with balls of radius one +which all draw pretty big just so that + + align:start position:0% +which all draw pretty big just so that + + + align:start position:0% +which all draw pretty big just so that +we don't have to make a bunch of small + + align:start position:0% +we don't have to make a bunch of small + + + align:start position:0% +we don't have to make a bunch of small +pictures so here are the balls of radius + + align:start position:0% +pictures so here are the balls of radius + + + align:start position:0% +pictures so here are the balls of radius +one + + align:start position:0% + + + + align:start position:0% + +well we know then is that one of these + + align:start position:0% +well we know then is that one of these + + + align:start position:0% +well we know then is that one of these +let's say this one + + align:start position:0% +let's say this one + + + align:start position:0% +let's say this one +contains infinitely many terms + + align:start position:0% +contains infinitely many terms + + + align:start position:0% +contains infinitely many terms +so we choose our Z1 + + align:start position:0% +so we choose our Z1 + + + align:start position:0% +so we choose our Z1 +to be here + + align:start position:0% +to be here + + + align:start position:0% +to be here +furthermore we have the intersection of + + align:start position:0% +furthermore we have the intersection of + + + align:start position:0% +furthermore we have the intersection of +this + + align:start position:0% +this + + + align:start position:0% +this +with balls of radius one half so I'll + + align:start position:0% +with balls of radius one half so I'll + + + align:start position:0% +with balls of radius one half so I'll +make these a little bit smaller + + align:start position:0% +make these a little bit smaller + + + align:start position:0% +make these a little bit smaller +sorry that's not quite good let me + + align:start position:0% +sorry that's not quite good let me + + + align:start position:0% +sorry that's not quite good let me +yeah these will be our my balls of + + align:start position:0% +yeah these will be our my balls of + + + align:start position:0% +yeah these will be our my balls of +radius one half + + align:start position:0% + + + + align:start position:0% + +would I know then is that the + + align:start position:0% +would I know then is that the + + + align:start position:0% +would I know then is that the +intersection of the balls of radius one + + align:start position:0% +intersection of the balls of radius one + + + align:start position:0% +intersection of the balls of radius one +half and the ball is of radius one + + align:start position:0% +half and the ball is of radius one + + + align:start position:0% +half and the ball is of radius one +there's only going to be finally many of + + align:start position:0% +there's only going to be finally many of + + + align:start position:0% +there's only going to be finally many of +them by assumption and the fact that + + align:start position:0% +them by assumption and the fact that + + + align:start position:0% +them by assumption and the fact that +there are finally many of them implies + + align:start position:0% +there are finally many of them implies + + + align:start position:0% +there are finally many of them implies +that there exists infinitely many of + + align:start position:0% +that there exists infinitely many of + + + align:start position:0% +that there exists infinitely many of +them + + align:start position:0% +them + + + align:start position:0% +them +that lie in one of these balls one of + + align:start position:0% +that lie in one of these balls one of + + + align:start position:0% +that lie in one of these balls one of +these balls of radius one half + + align:start position:0% +these balls of radius one half + + + align:start position:0% +these balls of radius one half +intersected one of the balls of radius + + align:start position:0% +intersected one of the balls of radius + + + align:start position:0% +intersected one of the balls of radius +one + + align:start position:0% +one + + + align:start position:0% +one +so what we can do is choose Z2 + + align:start position:0% +so what we can do is choose Z2 + + + align:start position:0% +so what we can do is choose Z2 +to be in this intersection of them and + + align:start position:0% +to be in this intersection of them and + + + align:start position:0% +to be in this intersection of them and +we're going to reiterate this process + + align:start position:0% +we're going to reiterate this process + + + align:start position:0% +we're going to reiterate this process +we're going to assume that Z3 is one of + + align:start position:0% +we're going to assume that Z3 is one of + + + align:start position:0% +we're going to assume that Z3 is one of +the infinitely many points in the + + align:start position:0% +the infinitely many points in the + + + align:start position:0% +the infinitely many points in the +intersection of balls of radius one + + align:start position:0% +intersection of balls of radius one + + + align:start position:0% +intersection of balls of radius one +third one half and one + + align:start position:0% +third one half and one + + + align:start position:0% +third one half and one +and so on and so forth and what we hope + + align:start position:0% +and so on and so forth and what we hope + + + align:start position:0% +and so on and so forth and what we hope +to show + + align:start position:0% +to show + + + align:start position:0% +to show +is that this sequence is going to be + + align:start position:0% +is that this sequence is going to be + + + align:start position:0% +is that this sequence is going to be +cushy + + align:start position:0% +cushy + + + align:start position:0% +cushy +but that's not at this point going to be + + align:start position:0% +but that's not at this point going to be + + + align:start position:0% +but that's not at this point going to be +too hard to do + + align:start position:0% +too hard to do + + + align:start position:0% +too hard to do +because okay let me write this somewhere + + align:start position:0% +because okay let me write this somewhere + + + align:start position:0% +because okay let me write this somewhere +fully we're going to choose z k to be in + + align:start position:0% +fully we're going to choose z k to be in + + + align:start position:0% +fully we're going to choose z k to be in +the intersection + + align:start position:0% +the intersection + + + align:start position:0% +the intersection +of balls of radius + + align:start position:0% +of balls of radius + + + align:start position:0% +of balls of radius +NK + + align:start position:0% +NK + + + align:start position:0% +NK +of n from n equals 1 to K + + align:start position:0% + + + + align:start position:0% + +yeah balls of radius one to K + + align:start position:0% +yeah balls of radius one to K + + + align:start position:0% +yeah balls of radius one to K +and now we want to show that this + + align:start position:0% +and now we want to show that this + + + align:start position:0% +and now we want to show that this +sequence is going to be koshy well + + align:start position:0% +sequence is going to be koshy well + + + align:start position:0% +sequence is going to be koshy well +what's the distance or choose + + align:start position:0% +what's the distance or choose + + + align:start position:0% +what's the distance or choose +for all Epsilon bigger than zero + + align:start position:0% +for all Epsilon bigger than zero + + + align:start position:0% +for all Epsilon bigger than zero +choose n in the natural numbers + + align:start position:0% +choose n in the natural numbers + + + align:start position:0% +choose n in the natural numbers +such that 1 over n is less than Epsilon + + align:start position:0% +such that 1 over n is less than Epsilon + + + align:start position:0% +such that 1 over n is less than Epsilon +then what do we know well for all n and + + align:start position:0% +then what do we know well for all n and + + + align:start position:0% +then what do we know well for all n and +M bigger than or equal to n + + align:start position:0% +M bigger than or equal to n + + + align:start position:0% +M bigger than or equal to n +we know then that z n and z m + + align:start position:0% +we know then that z n and z m + + + align:start position:0% +we know then that z n and z m +are both going to be contained in the + + align:start position:0% +are both going to be contained in the + + + align:start position:0% +are both going to be contained in the +ball of radius one over n of one of the + + align:start position:0% +ball of radius one over n of one of the + + + align:start position:0% +ball of radius one over n of one of the +Y I's I won't describe which one because + + align:start position:0% +Y I's I won't describe which one because + + + align:start position:0% +Y I's I won't describe which one because +it's a little bit annoying but we know + + align:start position:0% +it's a little bit annoying but we know + + + align:start position:0% +it's a little bit annoying but we know +that they both must lie in one over n + + align:start position:0% +that they both must lie in one over n + + + align:start position:0% +that they both must lie in one over n +because they're in this intersection of + + align:start position:0% +because they're in this intersection of + + + align:start position:0% +because they're in this intersection of +all these terms so what we know then + + align:start position:0% +all these terms so what we know then + + + align:start position:0% +all these terms so what we know then +is at the distance from ZN to Z M must + + align:start position:0% +is at the distance from ZN to Z M must + + + align:start position:0% +is at the distance from ZN to Z M must +be less than one over n or less than or + + align:start position:0% +be less than one over n or less than or + + + align:start position:0% +be less than one over n or less than or +equal to 1 over n + + align:start position:0% +equal to 1 over n + + + align:start position:0% +equal to 1 over n +Which is less than Epsilon which implies + + align:start position:0% +Which is less than Epsilon which implies + + + align:start position:0% +Which is less than Epsilon which implies +that the zis must be koshy so therefore + + align:start position:0% +that the zis must be koshy so therefore + + + align:start position:0% +that the zis must be koshy so therefore +the Z i's are koshy + + align:start position:0% +the Z i's are koshy + + + align:start position:0% +the Z i's are koshy +and by koshy completeness + + align:start position:0% +and by koshy completeness + + + align:start position:0% +and by koshy completeness +we know that there exists a limit point + + align:start position:0% +we know that there exists a limit point + + + align:start position:0% +we know that there exists a limit point +z i converges to some Z in x + + align:start position:0% +z i converges to some Z in x + + + align:start position:0% +z i converges to some Z in x +but recall again that our Z i's are + + align:start position:0% +but recall again that our Z i's are + + + align:start position:0% +but recall again that our Z i's are +constructed from our original sequence + + align:start position:0% +constructed from our original sequence + + + align:start position:0% +constructed from our original sequence +they're convergent they're a subsequence + + align:start position:0% +they're convergent they're a subsequence + + + align:start position:0% +they're convergent they're a subsequence +of our original sequence + + align:start position:0% +of our original sequence + + + align:start position:0% +of our original sequence +so what we've shown is that there is a + + align:start position:0% +so what we've shown is that there is a + + + align:start position:0% +so what we've shown is that there is a +convergent subsequence of our sequence + + align:start position:0% +convergent subsequence of our sequence + + + align:start position:0% +convergent subsequence of our sequence +in x and this is exactly what we sought + + align:start position:0% +in x and this is exactly what we sought + + + align:start position:0% +in x and this is exactly what we sought +out to show and this shows that totally + + align:start position:0% +out to show and this shows that totally + + + align:start position:0% +out to show and this shows that totally +bounded and koshy complete implies + + align:start position:0% +bounded and koshy complete implies + + + align:start position:0% +bounded and koshy complete implies +sequentially compact + + align:start position:0% +sequentially compact + + + align:start position:0% +sequentially compact +and this is the end of our four-part + + align:start position:0% +and this is the end of our four-part + + + align:start position:0% +and this is the end of our four-part +proof + + align:start position:0% + + + + align:start position:0% + +so again to reiterate we've shown that + + align:start position:0% +so again to reiterate we've shown that + + + align:start position:0% +so again to reiterate we've shown that +topologically compact is the same as + + align:start position:0% +topologically compact is the same as + + + align:start position:0% +topologically compact is the same as +sequentially compact where here we use + + align:start position:0% +sequentially compact where here we use + + + align:start position:0% +sequentially compact where here we use +the big numberlema and totally + + align:start position:0% +the big numberlema and totally + + + align:start position:0% +the big numberlema and totally +boundedness + + align:start position:0% +boundedness + + + align:start position:0% +boundedness +then from here we show that sequentially + + align:start position:0% +then from here we show that sequentially + + + align:start position:0% +then from here we show that sequentially +compact is the same as totally bounded + + align:start position:0% +compact is the same as totally bounded + + + align:start position:0% +compact is the same as totally bounded +and koshy complete + + align:start position:0% +and koshy complete + + + align:start position:0% +and koshy complete +takoshi complete didn't take too much + + align:start position:0% +takoshi complete didn't take too much + + + align:start position:0% +takoshi complete didn't take too much +more work that was pretty short the + + align:start position:0% +more work that was pretty short the + + + align:start position:0% +more work that was pretty short the +other direction required quite a bit of + + align:start position:0% +other direction required quite a bit of + + + align:start position:0% +other direction required quite a bit of +maneuvering to get that convergent + + align:start position:0% +maneuvering to get that convergent + + + align:start position:0% +maneuvering to get that convergent +subsequence but again the notes contain + + align:start position:0% +subsequence but again the notes contain + + + align:start position:0% +subsequence but again the notes contain +this more fully if you want to read + + align:start position:0% +this more fully if you want to read + + + align:start position:0% +this more fully if you want to read +through it slowly and at your own pace + + align:start position:0% +through it slowly and at your own pace + + + align:start position:0% +through it slowly and at your own pace +but lastly we showed and furthermore + + align:start position:0% +but lastly we showed and furthermore + + + align:start position:0% +but lastly we showed and furthermore +lastly we showed that one is the same as + + align:start position:0% +lastly we showed that one is the same as + + + align:start position:0% +lastly we showed that one is the same as +four we're topologically compact is the + + align:start position:0% +four we're topologically compact is the + + + align:start position:0% +four we're topologically compact is the +same as closed subsets with the final + + align:start position:0% +same as closed subsets with the final + + + align:start position:0% +same as closed subsets with the final +intersection property having non-empty + + align:start position:0% +intersection property having non-empty + + + align:start position:0% +intersection property having non-empty +intersection and now let's think + + align:start position:0% +intersection and now let's think + + + align:start position:0% +intersection and now let's think +carefully about how each of these proofs + + align:start position:0% +carefully about how each of these proofs + + + align:start position:0% +carefully about how each of these proofs +went because they each have their own + + align:start position:0% +went because they each have their own + + + align:start position:0% +went because they each have their own +purpose in a proof + + align:start position:0% +purpose in a proof + + + align:start position:0% +purpose in a proof +about metric spaces + + align:start position:0% +about metric spaces + + + align:start position:0% +about metric spaces +to show that one was the same as four we + + align:start position:0% +to show that one was the same as four we + + + align:start position:0% +to show that one was the same as four we +looked at open covers right we took the + + align:start position:0% +looked at open covers right we took the + + + align:start position:0% +looked at open covers right we took the +open cover definition and looked at + + align:start position:0% +open cover definition and looked at + + + align:start position:0% +open cover definition and looked at +complements of closed sets and being + + align:start position:0% +complements of closed sets and being + + + align:start position:0% +complements of closed sets and being +open and complements of open sets being + + align:start position:0% +open and complements of open sets being + + + align:start position:0% +open and complements of open sets being +closed and we used all these different + + align:start position:0% +closed and we used all these different + + + align:start position:0% +closed and we used all these different +properties like that and that makes a + + align:start position:0% +properties like that and that makes a + + + align:start position:0% +properties like that and that makes a +lot of sense because both definitions + + align:start position:0% +lot of sense because both definitions + + + align:start position:0% +lot of sense because both definitions +are in terms of closed and open sets but + + align:start position:0% +are in terms of closed and open sets but + + + align:start position:0% +are in terms of closed and open sets but +the show is sequentially compact was the + + align:start position:0% +the show is sequentially compact was the + + + align:start position:0% +the show is sequentially compact was the +same as totally boundated Koshi complete + + align:start position:0% +same as totally boundated Koshi complete + + + align:start position:0% +same as totally boundated Koshi complete +we use definitions of sequential + + align:start position:0% +we use definitions of sequential + + + align:start position:0% +we use definitions of sequential +compactness right because it's so much + + align:start position:0% +compactness right because it's so much + + + align:start position:0% +compactness right because it's so much +easier to look at convergent + + align:start position:0% +easier to look at convergent + + + align:start position:0% +easier to look at convergent +subsequences and such when you're + + align:start position:0% +subsequences and such when you're + + + align:start position:0% +subsequences and such when you're +looking at sequential compactness so we + + align:start position:0% +looking at sequential compactness so we + + + align:start position:0% +looking at sequential compactness so we +could have proven that one implies three + + align:start position:0% +could have proven that one implies three + + + align:start position:0% +could have proven that one implies three +but it would have been a little bit more + + align:start position:0% +but it would have been a little bit more + + + align:start position:0% +but it would have been a little bit more +difficult and a little bit harder to + + align:start position:0% +difficult and a little bit harder to + + + align:start position:0% +difficult and a little bit harder to +maneuver around and in fact that's why + + align:start position:0% +maneuver around and in fact that's why + + + align:start position:0% +maneuver around and in fact that's why +I've shown these four properties today + + align:start position:0% +I've shown these four properties today + + + align:start position:0% +I've shown these four properties today +because if you're in a class where + + align:start position:0% +because if you're in a class where + + + align:start position:0% +because if you're in a class where +you're proving facts about metric spaces + + align:start position:0% + + + + align:start position:0% + +you need to show you need to use the + + align:start position:0% +you need to show you need to use the + + + align:start position:0% +you need to show you need to use the +property that makes the most sense to + + align:start position:0% +property that makes the most sense to + + + align:start position:0% +property that makes the most sense to +use in a given moment for instance on + + align:start position:0% +use in a given moment for instance on + + + align:start position:0% +use in a given moment for instance on +your problem set you're going to be + + align:start position:0% +your problem set you're going to be + + + align:start position:0% +your problem set you're going to be +asked to show that the union of finitely + + align:start position:0% +asked to show that the union of finitely + + + align:start position:0% +asked to show that the union of finitely +many compact sets is going to be compact + + align:start position:0% +many compact sets is going to be compact + + + align:start position:0% +many compact sets is going to be compact +how do you know that this is going to be + + align:start position:0% +how do you know that this is going to be + + + align:start position:0% +how do you know that this is going to be +true + + align:start position:0% +true + + + align:start position:0% +true +well you can use sequential compactness + + align:start position:0% +well you can use sequential compactness + + + align:start position:0% +well you can use sequential compactness +you can use topological compactness you + + align:start position:0% +you can use topological compactness you + + + align:start position:0% +you can use topological compactness you +can use any of these four properties + + align:start position:0% +can use any of these four properties + + + align:start position:0% +can use any of these four properties +that you still wish to choose But be + + align:start position:0% +that you still wish to choose But be + + + align:start position:0% +that you still wish to choose But be +sure to think carefully about which one + + align:start position:0% +sure to think carefully about which one + + + align:start position:0% +sure to think carefully about which one +because one of them might be a little + + align:start position:0% +because one of them might be a little + + + align:start position:0% +because one of them might be a little +bit easier so I won't discredit you if + + align:start position:0% +bit easier so I won't discredit you if + + + align:start position:0% +bit easier so I won't discredit you if +you use any of the other ones + + align:start position:0% +you use any of the other ones + + + align:start position:0% +you use any of the other ones +and this is true in general when you're + + align:start position:0% +and this is true in general when you're + + + align:start position:0% +and this is true in general when you're +going into proofs about metric spaces + + align:start position:0% +going into proofs about metric spaces + + + align:start position:0% +going into proofs about metric spaces +having the intuition from one definition + + align:start position:0% +having the intuition from one definition + + + align:start position:0% +having the intuition from one definition +to the other is deeply important and + + align:start position:0% +to the other is deeply important and + + + align:start position:0% +to the other is deeply important and +very useful to know + + align:start position:0% +very useful to know + + + align:start position:0% +very useful to know +so that will conclude today's lecture on + + align:start position:0% +so that will conclude today's lecture on + + + align:start position:0% +so that will conclude today's lecture on +next Thursday we're going to prove some + + align:start position:0% +next Thursday we're going to prove some + + + align:start position:0% +next Thursday we're going to prove some +new facts about compact spaces and in + + align:start position:0% +new facts about compact spaces and in + + + align:start position:0% +new facts about compact spaces and in +particular what we're going to show or + + align:start position:0% +particular what we're going to show or + + + align:start position:0% +particular what we're going to show or +talk about is the history of compact + + align:start position:0% +talk about is the history of compact + + + align:start position:0% +talk about is the history of compact +metric spaces and why they were + + align:start position:0% +metric spaces and why they were + + + align:start position:0% +metric spaces and why they were +developed in the first place which comes + + align:start position:0% +developed in the first place which comes + + + align:start position:0% +developed in the first place which comes +from what is known as the dirichlet + + align:start position:0% +from what is known as the dirichlet + + + align:start position:0% +from what is known as the dirichlet +problem but I'll leave that discussion + + align:start position:0% +problem but I'll leave that discussion + + + align:start position:0% +problem but I'll leave that discussion +until next Thursday until then have a + + align:start position:0% +until next Thursday until then have a + + + align:start position:0% +until next Thursday until then have a +great weekend thank you \ No newline at end of file diff --git a/S1PUUyVdC9M.txt b/S1PUUyVdC9M.txt new file mode 100644 index 0000000000000000000000000000000000000000..a98d37e11ad7d66fe1d6c0c4e5f2295fb2e05b4f --- /dev/null +++ b/S1PUUyVdC9M.txt @@ -0,0 +1,111 @@ +Now let's turn our attention to the second +class of instructions: load (LD) and store + +(ST), which allow the CPU to access values +in memory. + +Note that since the Beta is a load-store architecture +these instructions are the *only* mechanism + +for accessing memory values. + +The LD and ST instructions use the same instruction +template as the ALU-with-constant instructions. + +To access memory, we'll need a memory address, +which is computed by adding the value of the + +"ra" register to the sign-extended 16-bit +constant from the low-order 16 bits of the + +instruction. + +This computation is exactly the one performed +by the ADDC instruction - so we'll reuse that + +hardware - and the sum is sent to main memory +as the byte address of the location to be + +accessed. + +For the LD instruction, the data returned +by main memory is written to the "rc" register. + +The store instruction (ST) performs the same +address calculation as LD, then reads the + +data value from the "rc" register and sends +both to main memory. + +The ST instruction is special in several ways: +it's the only instruction that needs to read + +the value of the "rc" register, so we'll need +to adjust the datapath hardware slightly to + +accommodate that need. + +And since "rc" is serving as a source operand, +it appears as the first operand in the symbolic + +form of the instruction, followed by "const" +and "ra" which are specifying the destination + +address. + +ST is the only instruction that does *not* +write a result into the register file at end + +of the instruction. + +Here's the example we saw earlier, where we +needed to load the value of the variable x + +from memory, multiply it by 37 and write the +result back to the memory location that holds + +the value of the variable y. + +Now that we have actual Beta instructions, +we've expressed the computation as a sequence + +of three instructions. + +To access the value of variable x, the LD +instruction adds the contents of R31 to the + +constant 0x1008, which sums to 0x1008, the +address we need to access. + +The ST instruction specifies a similar address +calculation to write into the location for + +the variable y. + +The address calculation performed by LD and +ST works well when the locations we need to + +access have addresses that fit into the 16-bit +constant field. + +What happens when we need to access locations +at addresses higher than 0x7FFF? + +Then we need to treat those addresses as we +would any large constant, and store those + +large addresses in main memory so they can +be loaded into a register to be used by LD + +and ST. + +Okay, but what if the number of large constants +we need to store is greater than will fit + +in low memory, i.e., the addresses we can +access directly? + +To solve this problem, the Beta includes a +"load relative" (LDR) instruction, which we'll + +see in the lecture on the Beta implementation. \ No newline at end of file diff --git a/SPDZbn6QC4c.txt b/SPDZbn6QC4c.txt new file mode 100644 index 0000000000000000000000000000000000000000..0c11cc957ca297622e3924a1bf8555e694a92ddb --- /dev/null +++ b/SPDZbn6QC4c.txt @@ -0,0 +1,1635 @@ +align:start position:0% + +at this point i'm going to talk about + + align:start position:0% +at this point i'm going to talk about + + + align:start position:0% +at this point i'm going to talk about +the third element of the garage case we + + align:start position:0% +the third element of the garage case we + + + align:start position:0% +the third element of the garage case we +already started with the idea of what + + align:start position:0% +already started with the idea of what + + + align:start position:0% +already started with the idea of what +the deterministic engineering design was + + align:start position:0% +the deterministic engineering design was + + + align:start position:0% +the deterministic engineering design was +then we saw how that analysis led to a + + align:start position:0% +then we saw how that analysis led to a + + + align:start position:0% +then we saw how that analysis led to a +wrong estimate of the value and in fact + + align:start position:0% +wrong estimate of the value and in fact + + + align:start position:0% +wrong estimate of the value and in fact +the wrong design once we accounted for + + align:start position:0% +the wrong design once we accounted for + + + align:start position:0% +the wrong design once we accounted for +the reality of uncertainty + + align:start position:0% +the reality of uncertainty + + + align:start position:0% +the reality of uncertainty +now let's think how we can be proactive + + align:start position:0% +now let's think how we can be proactive + + + align:start position:0% +now let's think how we can be proactive +about this design and we're going to do + + align:start position:0% +about this design and we're going to do + + + align:start position:0% +about this design and we're going to do +that by introducing flexibility what + + align:start position:0% +that by introducing flexibility what + + + align:start position:0% +that by introducing flexibility what +does that mean + + align:start position:0% +does that mean + + + align:start position:0% +does that mean +the flexibility is the ability to adjust + + align:start position:0% +the flexibility is the ability to adjust + + + align:start position:0% +the flexibility is the ability to adjust +the project to the actual needs + + align:start position:0% +the project to the actual needs + + + align:start position:0% +the project to the actual needs +according to the future how the future + + align:start position:0% +according to the future how the future + + + align:start position:0% +according to the future how the future +develops in particular it means that if + + align:start position:0% +develops in particular it means that if + + + align:start position:0% +develops in particular it means that if +the future is very positive in terms of + + align:start position:0% +the future is very positive in terms of + + + align:start position:0% +the future is very positive in terms of +demand and you'd like to have greater + + align:start position:0% +demand and you'd like to have greater + + + align:start position:0% +demand and you'd like to have greater +capacity that you have the capability of + + align:start position:0% +capacity that you have the capability of + + + align:start position:0% +capacity that you have the capability of +adding that if needed + + align:start position:0% +adding that if needed + + + align:start position:0% +adding that if needed +uh we it also presumes that we are + + align:start position:0% +uh we it also presumes that we are + + + align:start position:0% +uh we it also presumes that we are +managing this project we just don't + + align:start position:0% +managing this project we just don't + + + align:start position:0% +managing this project we just don't +create it then say there it's off on its + + align:start position:0% +create it then say there it's off on its + + + align:start position:0% +create it then say there it's off on its +own it's on autopilot no we have a + + align:start position:0% +own it's on autopilot no we have a + + + align:start position:0% +own it's on autopilot no we have a +system and we manage it appropriately so + + align:start position:0% +system and we manage it appropriately so + + + align:start position:0% +system and we manage it appropriately so +it's very important to understand that + + align:start position:0% +it's very important to understand that + + + align:start position:0% +it's very important to understand that +if we want to deliver the value of a + + align:start position:0% +if we want to deliver the value of a + + + align:start position:0% +if we want to deliver the value of a +design it's not only what we do at the + + align:start position:0% +design it's not only what we do at the + + + align:start position:0% +design it's not only what we do at the +beginning but how we manage the project + + align:start position:0% +beginning but how we manage the project + + + align:start position:0% +beginning but how we manage the project +as it encounters different situations + + align:start position:0% +as it encounters different situations + + + align:start position:0% +as it encounters different situations +and has to deal with different + + align:start position:0% +and has to deal with different + + + align:start position:0% +and has to deal with different +possibilities and opportunities + + align:start position:0% +possibilities and opportunities + + + align:start position:0% +possibilities and opportunities +how do we do this for the garage + + align:start position:0% +how do we do this for the garage + + + align:start position:0% +how do we do this for the garage +for the garage case what we do is we + + align:start position:0% +for the garage case what we do is we + + + align:start position:0% +for the garage case what we do is we +enable the addition of more capacity + + align:start position:0% +enable the addition of more capacity + + + align:start position:0% +enable the addition of more capacity +that is it has to have the strength to + + align:start position:0% +that is it has to have the strength to + + + align:start position:0% +that is it has to have the strength to +carry more loads it has if you want fat + + align:start position:0% +carry more loads it has if you want fat + + + align:start position:0% +carry more loads it has if you want fat +columns with more strength of them it + + align:start position:0% +columns with more strength of them it + + + align:start position:0% +columns with more strength of them it +has to have bigger foundations to carry + + align:start position:0% +has to have bigger foundations to carry + + + align:start position:0% +has to have bigger foundations to carry +the loads on the soil and it has to have + + align:start position:0% +the loads on the soil and it has to have + + + align:start position:0% +the loads on the soil and it has to have +a + + align:start position:0% +a + + + align:start position:0% +a +building system that you can easily add + + align:start position:0% +building system that you can easily add + + + align:start position:0% +building system that you can easily add +to + + align:start position:0% +to + + + align:start position:0% +to +in this case a precast + + align:start position:0% +in this case a precast + + + align:start position:0% +in this case a precast +situation you build it off-site can + + align:start position:0% +situation you build it off-site can + + + align:start position:0% +situation you build it off-site can +bring it in and can expand it + + align:start position:0% +bring it in and can expand it + + + align:start position:0% +bring it in and can expand it +with a minimal closure of the garage + + align:start position:0% +with a minimal closure of the garage + + + align:start position:0% +with a minimal closure of the garage +during the expansion period so + + align:start position:0% +during the expansion period so + + + align:start position:0% +during the expansion period so +that you have the ability to add floors + + align:start position:0% +that you have the ability to add floors + + + align:start position:0% +that you have the ability to add floors +and what happens + + align:start position:0% +and what happens + + + align:start position:0% +and what happens +now + + align:start position:0% +now + + + align:start position:0% +now +let's think about how we're going to + + align:start position:0% +let's think about how we're going to + + + align:start position:0% +let's think about how we're going to +analyze this with the simulation process + + align:start position:0% +analyze this with the simulation process + + + align:start position:0% +analyze this with the simulation process +here is a spreadsheet of it and this is + + align:start position:0% +here is a spreadsheet of it and this is + + + align:start position:0% +here is a spreadsheet of it and this is +the one for four floors now what we have + + align:start position:0% +the one for four floors now what we have + + + align:start position:0% +the one for four floors now what we have +here i'll won't explain in the detail + + align:start position:0% +here i'll won't explain in the detail + + + align:start position:0% +here i'll won't explain in the detail +how it works but i'll give you the idea + + align:start position:0% +how it works but i'll give you the idea + + + align:start position:0% +how it works but i'll give you the idea +of it is that we have a forecast here + + align:start position:0% +of it is that we have a forecast here + + + align:start position:0% +of it is that we have a forecast here +and this is a simulated forecast that is + + align:start position:0% +and this is a simulated forecast that is + + + align:start position:0% +and this is a simulated forecast that is +sometimes the top number of the forecast + + align:start position:0% +sometimes the top number of the forecast + + + align:start position:0% +sometimes the top number of the forecast +will be uh up sometimes it'll be down + + align:start position:0% +will be uh up sometimes it'll be down + + + align:start position:0% +will be uh up sometimes it'll be down +it'll be up and down over time + + align:start position:0% +it'll be up and down over time + + + align:start position:0% +it'll be up and down over time +and + + align:start position:0% +and + + + align:start position:0% +and +that's what we observe then we think + + align:start position:0% +that's what we observe then we think + + + align:start position:0% +that's what we observe then we think +about + + align:start position:0% +about + + + align:start position:0% +about +how we would exercise the flexibility + + align:start position:0% +how we would exercise the flexibility + + + align:start position:0% +how we would exercise the flexibility +that's available + + align:start position:0% +that's available + + + align:start position:0% +that's available +in terms of intelligent management so + + align:start position:0% +in terms of intelligent management so + + + align:start position:0% +in terms of intelligent management so +if the demand is not increasing we do + + align:start position:0% +if the demand is not increasing we do + + + align:start position:0% +if the demand is not increasing we do +not add the capability if the + + align:start position:0% +not add the capability if the + + + align:start position:0% +not add the capability if the +extra floors in particular if the demand + + align:start position:0% +extra floors in particular if the demand + + + align:start position:0% +extra floors in particular if the demand +however does increase + + align:start position:0% +however does increase + + + align:start position:0% +however does increase +then it looks like we'd be valuable to + + align:start position:0% +then it looks like we'd be valuable to + + + align:start position:0% +then it looks like we'd be valuable to +have more floors on it we add them so in + + align:start position:0% +have more floors on it we add them so in + + + align:start position:0% +have more floors on it we add them so in +we've embedded in here uh through what's + + align:start position:0% +we've embedded in here uh through what's + + + align:start position:0% +we've embedded in here uh through what's +called if statements that looks at + + align:start position:0% +called if statements that looks at + + + align:start position:0% +called if statements that looks at +what's been happening and what would be + + align:start position:0% +what's been happening and what would be + + + align:start position:0% +what's been happening and what would be +the intelligent thing to do and for each + + align:start position:0% +the intelligent thing to do and for each + + + align:start position:0% +the intelligent thing to do and for each +simulation that we run we + + align:start position:0% +simulation that we run we + + + align:start position:0% +simulation that we run we +factor that in and + + align:start position:0% +factor that in and + + + align:start position:0% +factor that in and +calculate the value so we do this for + + align:start position:0% +calculate the value so we do this for + + + align:start position:0% +calculate the value so we do this for +thousands of times a couple thousand in + + align:start position:0% +thousands of times a couple thousand in + + + align:start position:0% +thousands of times a couple thousand in +this particular analysis and we look at + + align:start position:0% +this particular analysis and we look at + + + align:start position:0% +this particular analysis and we look at +sometimes you expand because it's + + align:start position:0% +sometimes you expand because it's + + + align:start position:0% +sometimes you expand because it's +desirable sometimes you do not expand we + + align:start position:0% +desirable sometimes you do not expand we + + + align:start position:0% +desirable sometimes you do not expand we +look at the combination and figure out + + align:start position:0% +look at the combination and figure out + + + align:start position:0% +look at the combination and figure out +the overall expected value + + align:start position:0% +the overall expected value + + + align:start position:0% +the overall expected value +so + + align:start position:0% +so + + + align:start position:0% +so +um + + align:start position:0% +um + + + align:start position:0% +um +where does that lead us it leads us as + + align:start position:0% +where does that lead us it leads us as + + + align:start position:0% +where does that lead us it leads us as +we look at all the possibilities + + align:start position:0% +we look at all the possibilities + + + align:start position:0% +we look at all the possibilities +one story two story and so forth with + + align:start position:0% +one story two story and so forth with + + + align:start position:0% +one story two story and so forth with +and without the flexibility that the + + align:start position:0% +and without the flexibility that the + + + align:start position:0% +and without the flexibility that the +optimal design in this particular case + + align:start position:0% +optimal design in this particular case + + + align:start position:0% +optimal design in this particular case +with these numbers is not six stories + + align:start position:0% +with these numbers is not six stories + + + align:start position:0% +with these numbers is not six stories +which was a deterministic sign not the + + align:start position:0% +which was a deterministic sign not the + + + align:start position:0% +which was a deterministic sign not the +five stories which is the + + align:start position:0% +five stories which is the + + + align:start position:0% +five stories which is the +risk averse avoiding the downside + + align:start position:0% +risk averse avoiding the downside + + + align:start position:0% +risk averse avoiding the downside +approach where you recognize the + + align:start position:0% +approach where you recognize the + + + align:start position:0% +approach where you recognize the +uncertainty but it's four stories but + + align:start position:0% +uncertainty but it's four stories but + + + align:start position:0% +uncertainty but it's four stories but +four stories with the ability to expand + + align:start position:0% +four stories with the ability to expand + + + align:start position:0% +four stories with the ability to expand +when needed so observe what's happening + + align:start position:0% +when needed so observe what's happening + + + align:start position:0% +when needed so observe what's happening +you've built it smaller so it didn't + + align:start position:0% +you've built it smaller so it didn't + + + align:start position:0% +you've built it smaller so it didn't +cost as much as having five or six + + align:start position:0% +cost as much as having five or six + + + align:start position:0% +cost as much as having five or six +stories even though you had strong + + align:start position:0% +stories even though you had strong + + + align:start position:0% +stories even though you had strong +foundations + + align:start position:0% +foundations + + + align:start position:0% +foundations +so it's less exposure to the downside + + align:start position:0% +so it's less exposure to the downside + + + align:start position:0% +so it's less exposure to the downside +but you build it so that you get five + + align:start position:0% +but you build it so that you get five + + + align:start position:0% +but you build it so that you get five +six seven or eight stories if the demand + + align:start position:0% +six seven or eight stories if the demand + + + align:start position:0% +six seven or eight stories if the demand +occurred + + align:start position:0% +occurred + + + align:start position:0% +occurred +so + + align:start position:0% +so + + + align:start position:0% +so +here is the summary of the design + + align:start position:0% +here is the summary of the design + + + align:start position:0% +here is the summary of the design +results so that on the one hand we have + + align:start position:0% +results so that on the one hand we have + + + align:start position:0% +results so that on the one hand we have +the different + + align:start position:0% +the different + + + align:start position:0% +the different +possibilities and their performance over + + align:start position:0% +possibilities and their performance over + + + align:start position:0% +possibilities and their performance over +time and we have the value at the end + + align:start position:0% +time and we have the value at the end + + + align:start position:0% +time and we have the value at the end +so + + align:start position:0% +so + + + align:start position:0% +so +what we observe here is that the + + align:start position:0% +what we observe here is that the + + + align:start position:0% +what we observe here is that the +four-story building is the most + + align:start position:0% +four-story building is the most + + + align:start position:0% +four-story building is the most +productive one + + align:start position:0% +productive one + + + align:start position:0% +productive one +and we might have thought that the + + align:start position:0% +and we might have thought that the + + + align:start position:0% +and we might have thought that the +deterministic design with a value of six + + align:start position:0% +deterministic design with a value of six + + + align:start position:0% +deterministic design with a value of six +million was better but that result is a + + align:start position:0% +million was better but that result is a + + + align:start position:0% +million was better but that result is a +sham because given this uncertainty we + + align:start position:0% +sham because given this uncertainty we + + + align:start position:0% +sham because given this uncertainty we +will never get that result as the + + align:start position:0% +will never get that result as the + + + align:start position:0% +will never get that result as the +expected value its expected value will + + align:start position:0% +expected value its expected value will + + + align:start position:0% +expected value its expected value will +be lower and in fact in the case of uns + + align:start position:0% +be lower and in fact in the case of uns + + + align:start position:0% +be lower and in fact in the case of uns +the reality case with the uncertainty is + + align:start position:0% +the reality case with the uncertainty is + + + align:start position:0% +the reality case with the uncertainty is +we'll get only about three million with + + align:start position:0% +we'll get only about three million with + + + align:start position:0% +we'll get only about three million with +it as the value as compared to what we + + align:start position:0% +it as the value as compared to what we + + + align:start position:0% +it as the value as compared to what we +get + + align:start position:0% +get + + + align:start position:0% +get +so + + align:start position:0% +so + + + align:start position:0% +so +let's think about what's happening here + + align:start position:0% +let's think about what's happening here + + + align:start position:0% +let's think about what's happening here +we built it smaller less cost of the + + align:start position:0% +we built it smaller less cost of the + + + align:start position:0% +we built it smaller less cost of the +beginning + + align:start position:0% +beginning + + + align:start position:0% +beginning +less possibility of loss on the other + + align:start position:0% +less possibility of loss on the other + + + align:start position:0% +less possibility of loss on the other +hand we can build it up as much as seems + + align:start position:0% +hand we can build it up as much as seems + + + align:start position:0% +hand we can build it up as much as seems +appropriate in the particular conditions + + align:start position:0% +appropriate in the particular conditions + + + align:start position:0% +appropriate in the particular conditions +without a we have favorable demand and + + align:start position:0% +without a we have favorable demand and + + + align:start position:0% +without a we have favorable demand and +we can make more of value so + + align:start position:0% +we can make more of value so + + + align:start position:0% +we can make more of value so +let's look about + + align:start position:0% +let's look about + + + align:start position:0% +let's look about +what it is how we think about this + + align:start position:0% +what it is how we think about this + + + align:start position:0% +what it is how we think about this +overall for this particular design case + + align:start position:0% +overall for this particular design case + + + align:start position:0% +overall for this particular design case +so + + align:start position:0% +so + + + align:start position:0% +so +we need to have a multi-dimensional + + align:start position:0% +we need to have a multi-dimensional + + + align:start position:0% +we need to have a multi-dimensional +evaluation + + align:start position:0% +evaluation + + + align:start position:0% +evaluation +why multi-dimensional + + align:start position:0% +why multi-dimensional + + + align:start position:0% +why multi-dimensional +because + + align:start position:0% +because + + + align:start position:0% +because +since we have a distribution one number + + align:start position:0% +since we have a distribution one number + + + align:start position:0% +since we have a distribution one number +one + + align:start position:0% +one + + + align:start position:0% +one +value for it is not describing what's + + align:start position:0% +value for it is not describing what's + + + align:start position:0% +value for it is not describing what's +happening you care not only about the + + align:start position:0% +happening you care not only about the + + + align:start position:0% +happening you care not only about the +average you care about how bad can get + + align:start position:0% +average you care about how bad can get + + + align:start position:0% +average you care about how bad can get +how good can it get what's the + + align:start position:0% +how good can it get what's the + + + align:start position:0% +how good can it get what's the +possibilities in this particular case + + align:start position:0% +possibilities in this particular case + + + align:start position:0% +possibilities in this particular case +that we see that the uh the several + + align:start position:0% +that we see that the uh the several + + + align:start position:0% +that we see that the uh the several +factors that we're looking at in terms + + align:start position:0% +factors that we're looking at in terms + + + align:start position:0% +factors that we're looking at in terms +of the + + align:start position:0% +of the + + + align:start position:0% +of the +initial investment + + align:start position:0% +initial investment + + + align:start position:0% +initial investment +that we how much money do we have to put + + align:start position:0% +that we how much money do we have to put + + + align:start position:0% +that we how much money do we have to put +down to start the process it is lower + + align:start position:0% +down to start the process it is lower + + + align:start position:0% +down to start the process it is lower +for the flexible design because we build + + align:start position:0% +for the flexible design because we build + + + align:start position:0% +for the flexible design because we build +it smaller + + align:start position:0% +it smaller + + + align:start position:0% +it smaller +so what's the expected value of it it's + + align:start position:0% +so what's the expected value of it it's + + + align:start position:0% +so what's the expected value of it it's +very much larger than otherwise because + + align:start position:0% +very much larger than otherwise because + + + align:start position:0% +very much larger than otherwise because +we can take advantage of the good things + + align:start position:0% +we can take advantage of the good things + + + align:start position:0% +we can take advantage of the good things +and avoid the bad things + + align:start position:0% +and avoid the bad things + + + align:start position:0% +and avoid the bad things +and con + + align:start position:0% +and con + + + align:start position:0% +and con +in in that same way the maximum value we + + align:start position:0% +in in that same way the maximum value we + + + align:start position:0% +in in that same way the maximum value we +can get is larger the minimum value that + + align:start position:0% +can get is larger the minimum value that + + + align:start position:0% +can get is larger the minimum value that +we might be forced to accept is smaller + + align:start position:0% +we might be forced to accept is smaller + + + align:start position:0% +we might be forced to accept is smaller +so that it's good in all cases + + align:start position:0% +so that it's good in all cases + + + align:start position:0% +so that it's good in all cases +so + + align:start position:0% +so + + + align:start position:0% +so +everything is better why how did that + + align:start position:0% +everything is better why how did that + + + align:start position:0% +everything is better why how did that +happen + + align:start position:0% +happen + + + align:start position:0% +happen +that is we have not had a technological + + align:start position:0% +that is we have not had a technological + + + align:start position:0% +that is we have not had a technological +breakthrough in this case it is not a + + align:start position:0% +breakthrough in this case it is not a + + + align:start position:0% +breakthrough in this case it is not a +more + + align:start position:0% +more + + + align:start position:0% +more +sophisticated or advanced design it is + + align:start position:0% +sophisticated or advanced design it is + + + align:start position:0% +sophisticated or advanced design it is +because we have changed the + + align:start position:0% +because we have changed the + + + align:start position:0% +because we have changed the +design approach from we've changed the + + align:start position:0% +design approach from we've changed the + + + align:start position:0% +design approach from we've changed the +framing of the problem that instead of + + align:start position:0% +framing of the problem that instead of + + + align:start position:0% +framing of the problem that instead of +going to saying we're designing it for a + + align:start position:0% +going to saying we're designing it for a + + + align:start position:0% +going to saying we're designing it for a +fixed + + align:start position:0% +fixed + + + align:start position:0% +fixed +view of the future we folk and instead + + align:start position:0% +view of the future we folk and instead + + + align:start position:0% +view of the future we folk and instead +of focusing on this mythical and this + + align:start position:0% +of focusing on this mythical and this + + + align:start position:0% +of focusing on this mythical and this +fairy tale future that in fact will not + + align:start position:0% +fairy tale future that in fact will not + + + align:start position:0% +fairy tale future that in fact will not +be the exact case + + align:start position:0% +be the exact case + + + align:start position:0% +be the exact case +we change from that to managing the + + align:start position:0% +we change from that to managing the + + + align:start position:0% +we change from that to managing the +realistic uncertainties of the life by + + align:start position:0% +realistic uncertainties of the life by + + + align:start position:0% +realistic uncertainties of the life by +having the flexible design and therefore + + align:start position:0% +having the flexible design and therefore + + + align:start position:0% +having the flexible design and therefore +can adjust to the conditions and in that + + align:start position:0% +can adjust to the conditions and in that + + + align:start position:0% +can adjust to the conditions and in that +way + + align:start position:0% +way + + + align:start position:0% +way +have an overall better + + align:start position:0% +have an overall better + + + align:start position:0% +have an overall better +solution now in this case the flexible + + align:start position:0% +solution now in this case the flexible + + + align:start position:0% +solution now in this case the flexible +design was better on four counts that as + + align:start position:0% +design was better on four counts that as + + + align:start position:0% +design was better on four counts that as +i mentioned that may not always happen + + align:start position:0% +i mentioned that may not always happen + + + align:start position:0% +i mentioned that may not always happen +sometimes the situation is not so + + align:start position:0% +sometimes the situation is not so + + + align:start position:0% +sometimes the situation is not so +uniquely favorable but it's the kind of + + align:start position:0% +uniquely favorable but it's the kind of + + + align:start position:0% +uniquely favorable but it's the kind of +thing could happen because it's built in + + align:start position:0% +thing could happen because it's built in + + + align:start position:0% +thing could happen because it's built in +to the way of approaching it is less + + align:start position:0% +to the way of approaching it is less + + + align:start position:0% +to the way of approaching it is less +downside more upside + + align:start position:0% +downside more upside + + + align:start position:0% +downside more upside +lower cost than beginning overall it's a + + align:start position:0% +lower cost than beginning overall it's a + + + align:start position:0% +lower cost than beginning overall it's a +win-win at less cost + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/TZSBHuy8yhQ.txt b/TZSBHuy8yhQ.txt new file mode 100644 index 0000000000000000000000000000000000000000..deeb7fb1c5f466c4c25fb0e5a9d1fd080a41e6d8 --- /dev/null +++ b/TZSBHuy8yhQ.txt @@ -0,0 +1,15979 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +to view additional materials from + + align:start position:0% +to view additional materials from + + + align:start position:0% +to view additional materials from +hundreds of MIT courses visit MIT open + + align:start position:0% +hundreds of MIT courses visit MIT open + + + align:start position:0% +hundreds of MIT courses visit MIT open +courseware at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu all right welcome back to + + align:start position:0% +ocw.mit.edu all right welcome back to + + + align:start position:0% +ocw.mit.edu all right welcome back to +6890 uh today we continue our team of + + align:start position:0% +6890 uh today we continue our team of + + + align:start position:0% +6890 uh today we continue our team of +reductions NP hardness reductions from + + align:start position:0% +reductions NP hardness reductions from + + + align:start position:0% +reductions NP hardness reductions from +three partition uh yesterday we saw a + + align:start position:0% +three partition uh yesterday we saw a + + + align:start position:0% +three partition uh yesterday we saw a +couple of different reductions from + + align:start position:0% +couple of different reductions from + + + align:start position:0% +couple of different reductions from +three partition and then a bunch of + + align:start position:0% +three partition and then a bunch of + + + align:start position:0% +three partition and then a bunch of +reductions from those problems uh + + align:start position:0% +reductions from those problems uh + + + align:start position:0% +reductions from those problems uh +various puzzles uh the last one we + + align:start position:0% +various puzzles uh the last one we + + + align:start position:0% +various puzzles uh the last one we +covered was packing squares into a + + align:start position:0% +covered was packing squares into a + + + align:start position:0% +covered was packing squares into a +square this is just a reminder visually + + align:start position:0% +square this is just a reminder visually + + + align:start position:0% +square this is just a reminder visually +what it looks like uh but we're going to + + align:start position:0% +what it looks like uh but we're going to + + + align:start position:0% +what it looks like uh but we're going to +just take this result as given and our + + align:start position:0% +just take this result as given and our + + + align:start position:0% +just take this result as given and our +first MP hardness reduction will be from + + align:start position:0% +first MP hardness reduction will be from + + + align:start position:0% +first MP hardness reduction will be from +packing squares into a square and then + + align:start position:0% +packing squares into a square and then + + + align:start position:0% +packing squares into a square and then +we will see a bunch of possibly as many + + align:start position:0% +we will see a bunch of possibly as many + + + align:start position:0% +we will see a bunch of possibly as many +as eight reductions uh from three + + align:start position:0% +as eight reductions uh from three + + + align:start position:0% +as eight reductions uh from three +partition so uh without further Ado + + align:start position:0% +partition so uh without further Ado + + + align:start position:0% +partition so uh without further Ado +let's get started um the first problem + + align:start position:0% +let's get started um the first problem + + + align:start position:0% +let's get started um the first problem +we're going to talk about uh is Edge + + align:start position:0% +we're going to talk about uh is Edge + + + align:start position:0% +we're going to talk about uh is Edge +unfolding polyhedra this is a um + + align:start position:0% +unfolding polyhedra this is a um + + + align:start position:0% +unfolding polyhedra this is a um +geometric folding problem so if you're + + align:start position:0% +geometric folding problem so if you're + + + align:start position:0% +geometric folding problem so if you're +interested in more you can uh take + + align:start position:0% +interested in more you can uh take + + + align:start position:0% +interested in more you can uh take +6849 um but here's a simple if you've + + align:start position:0% +6849 um but here's a simple if you've + + + align:start position:0% +6849 um but here's a simple if you've +ever made a cube out of paper probably + + align:start position:0% +ever made a cube out of paper probably + + + align:start position:0% +ever made a cube out of paper probably +you cut out uh a cross shape and then + + align:start position:0% +you cut out uh a cross shape and then + + + align:start position:0% +you cut out uh a cross shape and then +folded it into the cube there but if you + + align:start position:0% +folded it into the cube there but if you + + + align:start position:0% +folded it into the cube there but if you +want to know how should I what shape + + align:start position:0% +want to know how should I what shape + + + align:start position:0% +want to know how should I what shape +should I cut out to make a cube then you + + align:start position:0% +should I cut out to make a cube then you + + + align:start position:0% +should I cut out to make a cube then you +want to know where should I cut which + + align:start position:0% +want to know where should I cut which + + + align:start position:0% +want to know where should I cut which +edges of the cube should I cut they're + + align:start position:0% +edges of the cube should I cut they're + + + align:start position:0% +edges of the cube should I cut they're +drawn in red here so that when I unfold + + align:start position:0% +drawn in red here so that when I unfold + + + align:start position:0% +drawn in red here so that when I unfold +it I get one connected piece without + + align:start position:0% +it I get one connected piece without + + + align:start position:0% +it I get one connected piece without +overlap um so for surfaces that are + + align:start position:0% +overlap um so for surfaces that are + + + align:start position:0% +overlap um so for surfaces that are +topologically a sphere uh you want to + + align:start position:0% +topologically a sphere uh you want to + + + align:start position:0% +topologically a sphere uh you want to +cut along a spanning tree of the edges + + align:start position:0% +cut along a spanning tree of the edges + + + align:start position:0% +cut along a spanning tree of the edges +um and for a cube that will always work + + align:start position:0% +um and for a cube that will always work + + + align:start position:0% +um and for a cube that will always work +but for some polyhedra like these two + + align:start position:0% +but for some polyhedra like these two + + + align:start position:0% +but for some polyhedra like these two +when you unfold you get overlap and in + + align:start position:0% +when you unfold you get overlap and in + + + align:start position:0% +when you unfold you get overlap and in +fact no matter which spanning tree of + + align:start position:0% +fact no matter which spanning tree of + + + align:start position:0% +fact no matter which spanning tree of +the edges you take for either of these + + align:start position:0% +the edges you take for either of these + + + align:start position:0% +the edges you take for either of these +two polyhedra + + align:start position:0% +two polyhedra + + + align:start position:0% +two polyhedra +uh you are guaranteed to fail you cannot + + align:start position:0% +uh you are guaranteed to fail you cannot + + + align:start position:0% +uh you are guaranteed to fail you cannot +make these out of one piece of paper uh + + align:start position:0% +make these out of one piece of paper uh + + + align:start position:0% +make these out of one piece of paper uh +by folding and get an exact cover uh so + + align:start position:0% +by folding and get an exact cover uh so + + + align:start position:0% +by folding and get an exact cover uh so +that's bad news and these are old + + align:start position:0% +that's bad news and these are old + + + align:start position:0% +that's bad news and these are old +results these are back in + + align:start position:0% +results these are back in + + + align:start position:0% +results these are back in +1998 um but it remained an open problem + + align:start position:0% +1998 um but it remained an open problem + + + align:start position:0% +1998 um but it remained an open problem +are there how many other examples are + + align:start position:0% +are there how many other examples are + + + align:start position:0% +are there how many other examples are +there if I give you a polyhedron I want + + align:start position:0% +there if I give you a polyhedron I want + + + align:start position:0% +there if I give you a polyhedron I want +to know is there an edge unfolding we + + align:start position:0% +to know is there an edge unfolding we + + + align:start position:0% +to know is there an edge unfolding we +only cut along the edges uh what's the + + align:start position:0% +only cut along the edges uh what's the + + + align:start position:0% +only cut along the edges uh what's the +complexity of that and the answer is + + align:start position:0% +complexity of that and the answer is + + + align:start position:0% +complexity of that and the answer is +it's NP + + align:start position:0% +it's NP + + + align:start position:0% +it's NP +complete um strongly NP complete + + align:start position:0% +complete um strongly NP complete + + + align:start position:0% +complete um strongly NP complete +slightly stronger this is not obviously + + align:start position:0% +slightly stronger this is not obviously + + + align:start position:0% +slightly stronger this is not obviously +a number problem but uh in Geometry you + + align:start position:0% +a number problem but uh in Geometry you + + + align:start position:0% +a number problem but uh in Geometry you +have this issue of what are the + + align:start position:0% +have this issue of what are the + + + align:start position:0% +have this issue of what are the +coordinates of the vertices so the + + align:start position:0% +coordinates of the vertices so the + + + align:start position:0% +coordinates of the vertices so the +coordinates could be exponentially large + + align:start position:0% +coordinates could be exponentially large + + + align:start position:0% +coordinates could be exponentially large +or they could just be polom large here + + align:start position:0% +or they could just be polom large here + + + align:start position:0% +or they could just be polom large here +they only need to be polom large so + + align:start position:0% +they only need to be polom large so + + + align:start position:0% +they only need to be polom large so +strongly mty complete this is a + + align:start position:0% +strongly mty complete this is a + + + align:start position:0% +strongly mty complete this is a +complicated proof uh so I'm just going + + align:start position:0% +complicated proof uh so I'm just going + + + align:start position:0% +complicated proof uh so I'm just going +to sketch the idea of how it works um at + + align:start position:0% +to sketch the idea of how it works um at + + + align:start position:0% +to sketch the idea of how it works um at +the beginning like most proofs there's + + align:start position:0% +the beginning like most proofs there's + + + align:start position:0% +the beginning like most proofs there's +some kind of like overall infrastructure + + align:start position:0% +some kind of like overall infrastructure + + + align:start position:0% +some kind of like overall infrastructure +that holds all the pieces together this + + align:start position:0% +that holds all the pieces together this + + + align:start position:0% +that holds all the pieces together this +is one part of that well this is the + + align:start position:0% +is one part of that well this is the + + + align:start position:0% +is one part of that well this is the +main infrastructure structure in this uh + + align:start position:0% +main infrastructure structure in this uh + + + align:start position:0% +main infrastructure structure in this uh +reduction there's some stuff around the + + align:start position:0% +reduction there's some stuff around the + + + align:start position:0% +reduction there's some stuff around the +side this is mainly to make the Surface + + align:start position:0% +side this is mainly to make the Surface + + + align:start position:0% +side this is mainly to make the Surface +uh topologically a sphere um the the + + align:start position:0% +uh topologically a sphere um the the + + + align:start position:0% +uh topologically a sphere um the the +focus is on uh a square face here with + + align:start position:0% +focus is on uh a square face here with + + + align:start position:0% +focus is on uh a square face here with +has a little slit in it and there's a + + align:start position:0% +has a little slit in it and there's a + + + align:start position:0% +has a little slit in it and there's a +tower coming out it's drawn uh Edge on + + align:start position:0% +tower coming out it's drawn uh Edge on + + + align:start position:0% +tower coming out it's drawn uh Edge on +here this is the part we actually care + + align:start position:0% +here this is the part we actually care + + + align:start position:0% +here this is the part we actually care +about uh I think actually it will be + + align:start position:0% +about uh I think actually it will be + + + align:start position:0% +about uh I think actually it will be +redrawn here so we'll really just be + + align:start position:0% +redrawn here so we'll really just be + + + align:start position:0% +redrawn here so we'll really just be +thinking about this and then there's + + align:start position:0% +thinking about this and then there's + + + align:start position:0% +thinking about this and then there's +some stuff that wraps it around and + + align:start position:0% +some stuff that wraps it around and + + + align:start position:0% +some stuff that wraps it around and +makes it a sphere without changing + + align:start position:0% +makes it a sphere without changing + + + align:start position:0% +makes it a sphere without changing +unfolding + + align:start position:0% +unfolding + + + align:start position:0% +unfolding +so don't worry too much about that + + align:start position:0% +so don't worry too much about that + + + align:start position:0% +so don't worry too much about that +mainly we have this giant uh think of it + + align:start position:0% +mainly we have this giant uh think of it + + + align:start position:0% +mainly we have this giant uh think of it +as an obstacle because we're not allowed + + align:start position:0% +as an obstacle because we're not allowed + + + align:start position:0% +as an obstacle because we're not allowed +to overlap when we unfold this thing so + + align:start position:0% +to overlap when we unfold this thing so + + + align:start position:0% +to overlap when we unfold this thing so +this shape can't be cut up because it + + align:start position:0% +this shape can't be cut up because it + + + align:start position:0% +this shape can't be cut up because it +has no edges except for here so this + + align:start position:0% +has no edges except for here so this + + + align:start position:0% +has no edges except for here so this +part can move around uh it turns out it + + align:start position:0% +part can move around uh it turns out it + + + align:start position:0% +part can move around uh it turns out it +will stay in there but it might just + + align:start position:0% +will stay in there but it might just + + + align:start position:0% +will stay in there but it might just +move up so we can make a little bit of + + align:start position:0% +move up so we can make a little bit of + + + align:start position:0% +move up so we can make a little bit of +space here uh there's there's this hole + + align:start position:0% +space here uh there's there's this hole + + + align:start position:0% +space here uh there's there's this hole +uh of this face and then there's this + + align:start position:0% +uh of this face and then there's this + + + align:start position:0% +uh of this face and then there's this +Tower that's sticking out into the third + + align:start position:0% +Tower that's sticking out into the third + + + align:start position:0% +Tower that's sticking out into the third +dimension and we need to somehow unfold + + align:start position:0% +dimension and we need to somehow unfold + + + align:start position:0% +dimension and we need to somehow unfold +that thing and fit it in here doesn't + + align:start position:0% +that thing and fit it in here doesn't + + + align:start position:0% +that thing and fit it in here doesn't +look possible uh because this is not + + align:start position:0% +look possible uh because this is not + + + align:start position:0% +look possible uh because this is not +quite drawn to scale um this is going to + + align:start position:0% +quite drawn to scale um this is going to + + + align:start position:0% +quite drawn to scale um this is going to +be super long so a lot of the stuff here + + align:start position:0% +be super long so a lot of the stuff here + + + align:start position:0% +be super long so a lot of the stuff here +is just going to be stuffed up the + + align:start position:0% +is just going to be stuffed up the + + + align:start position:0% +is just going to be stuffed up the +chimney so to speak um uh but also on + + align:start position:0% +chimney so to speak um uh but also on + + + align:start position:0% +chimney so to speak um uh but also on +the surface there's more stuff going on + + align:start position:0% +the surface there's more stuff going on + + + align:start position:0% +the surface there's more stuff going on +so let's zoom into this thing uh if we + + align:start position:0% +so let's zoom into this thing uh if we + + + align:start position:0% +so let's zoom into this thing uh if we +unfold that Tower into a plus sign uh + + align:start position:0% +unfold that Tower into a plus sign uh + + + align:start position:0% +unfold that Tower into a plus sign uh +most of it is lots of tiny um stuff + + align:start position:0% +most of it is lots of tiny um stuff + + + align:start position:0% +most of it is lots of tiny um stuff +called atoms which uh we will get to and + + align:start position:0% +called atoms which uh we will get to and + + + align:start position:0% +called atoms which uh we will get to and +then the kind of the interesting part + + align:start position:0% +then the kind of the interesting part + + + align:start position:0% +then the kind of the interesting part +from a three part partition standpoint + + align:start position:0% +from a three part partition standpoint + + + align:start position:0% +from a three part partition standpoint +or sorry from a square packing + + align:start position:0% +or sorry from a square packing + + + align:start position:0% +or sorry from a square packing +standpoint is there are some square + + align:start position:0% +standpoint is there are some square + + + align:start position:0% +standpoint is there are some square +faces and because we're Edge cutting uh + + align:start position:0% +faces and because we're Edge cutting uh + + + align:start position:0% +faces and because we're Edge cutting uh +our surface those squares will remain + + align:start position:0% +our surface those squares will remain + + + align:start position:0% +our surface those squares will remain +squares there's no edges on them so uh + + align:start position:0% +squares there's no edges on them so uh + + + align:start position:0% +squares there's no edges on them so uh +those guys somehow have to move around + + align:start position:0% +those guys somehow have to move around + + + align:start position:0% +those guys somehow have to move around +when you unfold and it's not drawn this + + align:start position:0% +when you unfold and it's not drawn this + + + align:start position:0% +when you unfold and it's not drawn this +way but the squares are large enough uh + + align:start position:0% +way but the squares are large enough uh + + + align:start position:0% +way but the squares are large enough uh +that they can't fit up the chimney okay + + align:start position:0% +that they can't fit up the chimney okay + + + align:start position:0% +that they can't fit up the chimney okay +this chimney is actually pretty narrow + + align:start position:0% +this chimney is actually pretty narrow + + + align:start position:0% +this chimney is actually pretty narrow +constant width and those guys are all + + align:start position:0% +constant width and those guys are all + + + align:start position:0% +constant width and those guys are all +really big so this other stuff can move + + align:start position:0% +really big so this other stuff can move + + + align:start position:0% +really big so this other stuff can move +up the chimney the squares will have to + + align:start position:0% +up the chimney the squares will have to + + + align:start position:0% +up the chimney the squares will have to +stay in this square and that's how we're + + align:start position:0% +stay in this square and that's how we're + + + align:start position:0% +stay in this square and that's how we're +going to get packing squares into + + align:start position:0% +going to get packing squares into + + + align:start position:0% +going to get packing squares into +squares okay now the challenge is what + + align:start position:0% +squares okay now the challenge is what + + + align:start position:0% +squares okay now the challenge is what +we want to be able to do is move the + + align:start position:0% +we want to be able to do is move the + + + align:start position:0% +we want to be able to do is move the +squares around freely um but in reality + + align:start position:0% +squares around freely um but in reality + + + align:start position:0% +squares around freely um but in reality +we need to make a connected 2D shape so + + align:start position:0% +we need to make a connected 2D shape so + + + align:start position:0% +we need to make a connected 2D shape so +somehow we need to connect together + + align:start position:0% +somehow we need to connect together + + + align:start position:0% +somehow we need to connect together +these squares by some stuff that's the + + align:start position:0% +these squares by some stuff that's the + + + align:start position:0% +these squares by some stuff that's the +mystery atoms uh so that basically we + + align:start position:0% +mystery atoms uh so that basically we + + + align:start position:0% +mystery atoms uh so that basically we +for any Square packing we can uh arrange + + align:start position:0% +for any Square packing we can uh arrange + + + align:start position:0% +for any Square packing we can uh arrange +to have those faces in that rough + + align:start position:0% +to have those faces in that rough + + + align:start position:0% +to have those faces in that rough +Arrangement and then the other stuff + + align:start position:0% +Arrangement and then the other stuff + + + align:start position:0% +Arrangement and then the other stuff +somehow connects everything together and + + align:start position:0% +somehow connects everything together and + + + align:start position:0% +somehow connects everything together and +whatever doesn't fit in here goes up the + + align:start position:0% +whatever doesn't fit in here goes up the + + + align:start position:0% +whatever doesn't fit in here goes up the +chimney so that's the plan uh if we zoom + + align:start position:0% +chimney so that's the plan uh if we zoom + + + align:start position:0% +chimney so that's the plan uh if we zoom +in uh right so this is sort of the the + + align:start position:0% +in uh right so this is sort of the the + + + align:start position:0% +in uh right so this is sort of the the +diagram of that plan imagine you have + + align:start position:0% +diagram of that plan imagine you have + + + align:start position:0% +diagram of that plan imagine you have +some placement of the squares um and + + align:start position:0% +some placement of the squares um and + + + align:start position:0% +some placement of the squares um and +we're going to try to connect all the + + align:start position:0% +we're going to try to connect all the + + + align:start position:0% +we're going to try to connect all the +pieces together uh maybe to some common + + align:start position:0% +pieces together uh maybe to some common + + + align:start position:0% +pieces together uh maybe to some common +root in the lower left corner first + + align:start position:0% +root in the lower left corner first + + + align:start position:0% +root in the lower left corner first +we're just going to draw some L's + + align:start position:0% +we're just going to draw some L's + + + align:start position:0% +we're just going to draw some L's +conceptually to connect them all to here + + align:start position:0% +conceptually to connect them all to here + + + align:start position:0% +conceptually to connect them all to here +um those cross which is not allowed but + + align:start position:0% +um those cross which is not allowed but + + + align:start position:0% +um those cross which is not allowed but +then we're going to reroute the L's to + + align:start position:0% +then we're going to reroute the L's to + + + align:start position:0% +then we're going to reroute the L's to +go around the uh so to get up to this + + align:start position:0% +go around the uh so to get up to this + + + align:start position:0% +go around the uh so to get up to this +box we're going to go around all of the + + align:start position:0% +box we're going to go around all of the + + + align:start position:0% +box we're going to go around all of the +other boxes below it um and in this way + + align:start position:0% +other boxes below it um and in this way + + + align:start position:0% +other boxes below it um and in this way +we get a non-crossing Arrangement if we + + align:start position:0% +we get a non-crossing Arrangement if we + + + align:start position:0% +we get a non-crossing Arrangement if we +zoom in even closer these I've drawn as + + align:start position:0% +zoom in even closer these I've drawn as + + + align:start position:0% +zoom in even closer these I've drawn as +lines but really they're little strips + + align:start position:0% +lines but really they're little strips + + + align:start position:0% +lines but really they're little strips +of paper and they may do weird things + + align:start position:0% +of paper and they may do weird things + + + align:start position:0% +of paper and they may do weird things +like zigzag back and forth how that + + align:start position:0% +like zigzag back and forth how that + + + align:start position:0% +like zigzag back and forth how that +happens we'll see in a moment um but + + align:start position:0% +happens we'll see in a moment um but + + + align:start position:0% +happens we'll see in a moment um but +this is to convince you that at least if + + align:start position:0% +this is to convince you that at least if + + + align:start position:0% +this is to convince you that at least if +we could place squares and they're not + + align:start position:0% +we could place squares and they're not + + + align:start position:0% +we could place squares and they're not +like right touching each other so we're + + align:start position:0% +like right touching each other so we're + + + align:start position:0% +like right touching each other so we're +going to shrink each square a tiny bit + + align:start position:0% +going to shrink each square a tiny bit + + + align:start position:0% +going to shrink each square a tiny bit +which I won't get into the details but + + align:start position:0% +which I won't get into the details but + + + align:start position:0% +which I won't get into the details but +if if the if they're integer squares + + align:start position:0% +if if the if they're integer squares + + + align:start position:0% +if if the if they're integer squares +let's say then we'll shrink them maybe + + align:start position:0% +let's say then we'll shrink them maybe + + + align:start position:0% +let's say then we'll shrink them maybe +by minus one over n or something polom + + align:start position:0% +by minus one over n or something polom + + + align:start position:0% +by minus one over n or something polom +small um and then that that gives us a + + align:start position:0% +small um and then that that gives us a + + + align:start position:0% +small um and then that that gives us a +little bit of room to Route all of these + + align:start position:0% +little bit of room to Route all of these + + + align:start position:0% +little bit of room to Route all of these +paths if we make them like 1 over n^ s + + align:start position:0% +paths if we make them like 1 over n^ s + + + align:start position:0% +paths if we make them like 1 over n^ s +or 1 over n cubed in thickness still + + align:start position:0% +or 1 over n cubed in thickness still + + + align:start position:0% +or 1 over n cubed in thickness still +polinomial so still strongly empty hard + + align:start position:0% +polinomial so still strongly empty hard + + + align:start position:0% +polinomial so still strongly empty hard +um so uh if we have a square pack + + align:start position:0% +um so uh if we have a square pack + + + align:start position:0% +um so uh if we have a square pack +we can connect them all up in this way + + align:start position:0% +we can connect them all up in this way + + + align:start position:0% +we can connect them all up in this way +if we have these magical atoms that can + + align:start position:0% +if we have these magical atoms that can + + + align:start position:0% +if we have these magical atoms that can +do whatever we want uh freely and that's + + align:start position:0% +do whatever we want uh freely and that's + + + align:start position:0% +do whatever we want uh freely and that's +the um so in a little more detail in + + align:start position:0% +the um so in a little more detail in + + + align:start position:0% +the um so in a little more detail in +this picture um the we imagine the atoms + + align:start position:0% +this picture um the we imagine the atoms + + + align:start position:0% +this picture um the we imagine the atoms +is somehow being connected together in a + + align:start position:0% +is somehow being connected together in a + + + align:start position:0% +is somehow being connected together in a +chain potentially and then when they + + align:start position:0% +chain potentially and then when they + + + align:start position:0% +chain potentially and then when they +unfold this is the fun part so um we + + align:start position:0% +unfold this is the fun part so um we + + + align:start position:0% +unfold this is the fun part so um we +maybe for connectivity purposes maybe + + align:start position:0% +maybe for connectivity purposes maybe + + + align:start position:0% +maybe for connectivity purposes maybe +first we want to visit B1 then we want a + + align:start position:0% +first we want to visit B1 then we want a + + + align:start position:0% +first we want to visit B1 then we want a +visit B2 and so on + + align:start position:0% +visit B2 and so on + + + align:start position:0% +visit B2 and so on +um + + align:start position:0% +um + + + align:start position:0% +um +and that corresponds to some traversal + + align:start position:0% +and that corresponds to some traversal + + + align:start position:0% +and that corresponds to some traversal +on the surface of this uh plus sign or + + align:start position:0% +on the surface of this uh plus sign or + + + align:start position:0% +on the surface of this uh plus sign or +the the tower that's sticking out uh and + + align:start position:0% +the the tower that's sticking out uh and + + + align:start position:0% +the the tower that's sticking out uh and +then in 2D when we unfold it we have a + + align:start position:0% +then in 2D when we unfold it we have a + + + align:start position:0% +then in 2D when we unfold it we have a +different thing in mind of whether we + + align:start position:0% +different thing in mind of whether we + + + align:start position:0% +different thing in mind of whether we +want it to go left or right so there's + + align:start position:0% +want it to go left or right so there's + + + align:start position:0% +want it to go left or right so there's +moving left or right intrinsically on + + align:start position:0% +moving left or right intrinsically on + + + align:start position:0% +moving left or right intrinsically on +the surface and then there's moving left + + align:start position:0% +the surface and then there's moving left + + + align:start position:0% +the surface and then there's moving left +and right in the unfolding so two + + align:start position:0% +and right in the unfolding so two + + + align:start position:0% +and right in the unfolding so two +separate things and conveniently this + + align:start position:0% +separate things and conveniently this + + + align:start position:0% +separate things and conveniently this +one structure is one of these boxes this + + align:start position:0% +one structure is one of these boxes this + + + align:start position:0% +one structure is one of these boxes this +is what we call the atom can do all of + + align:start position:0% +is what we call the atom can do all of + + + align:start position:0% +is what we call the atom can do all of +those things uh certainly not obvious + + align:start position:0% +those things uh certainly not obvious + + + align:start position:0% +those things uh certainly not obvious +from the picture it's just a little + + align:start position:0% +from the picture it's just a little + + + align:start position:0% +from the picture it's just a little +bumpy Square uh but you just trial the + + align:start position:0% +bumpy Square uh but you just trial the + + + align:start position:0% +bumpy Square uh but you just trial the +cases these are three of the cases not + + align:start position:0% +cases these are three of the cases not + + + align:start position:0% +cases these are three of the cases not +obvious but there turn out to be 10 if + + align:start position:0% +obvious but there turn out to be 10 if + + + align:start position:0% +obvious but there turn out to be 10 if +after you remove uh Reflections and + + align:start position:0% +after you remove uh Reflections and + + + align:start position:0% +after you remove uh Reflections and +rotations um there's a few things going + + align:start position:0% +rotations um there's a few things going + + + align:start position:0% +rotations um there's a few things going +on but the main thing going on is + + align:start position:0% +on but the main thing going on is + + + align:start position:0% +on but the main thing going on is +whether you're going left or right in + + align:start position:0% +whether you're going left or right in + + + align:start position:0% +whether you're going left or right in +the + + align:start position:0% +the + + + align:start position:0% +the +uh get just get this straight whether + + align:start position:0% +uh get just get this straight whether + + + align:start position:0% +uh get just get this straight whether +you're going left or right in + + align:start position:0% +you're going left or right in + + + align:start position:0% +you're going left or right in +intrinsically on the surface surface and + + align:start position:0% +intrinsically on the surface surface and + + + align:start position:0% +intrinsically on the surface surface and +whether you're going left or right or + + align:start position:0% +whether you're going left or right or + + + align:start position:0% +whether you're going left or right or +straight u in the unfolding so here you + + align:start position:0% +straight u in the unfolding so here you + + + align:start position:0% +straight u in the unfolding so here you +can see you're turning left in the + + align:start position:0% +can see you're turning left in the + + + align:start position:0% +can see you're turning left in the +unfolding you're going straight in the + + align:start position:0% +unfolding you're going straight in the + + + align:start position:0% +unfolding you're going straight in the +unfolding and you're turning left in the + + align:start position:0% +unfolding and you're turning left in the + + + align:start position:0% +unfolding and you're turning left in the +unfolding so the second coordinate is L + + align:start position:0% +unfolding so the second coordinate is L + + + align:start position:0% +unfolding so the second coordinate is L +S and L what's less obvious is if you + + align:start position:0% +S and L what's less obvious is if you + + + align:start position:0% +S and L what's less obvious is if you +fold this up and you you get the atom + + align:start position:0% +fold this up and you you get the atom + + + align:start position:0% +fold this up and you you get the atom +structure but the thing that you attach + + align:start position:0% +structure but the thing that you attach + + + align:start position:0% +structure but the thing that you attach +to here is on on the folded structure + + align:start position:0% +to here is on on the folded structure + + + align:start position:0% +to here is on on the folded structure +either to the left or to the left or to + + align:start position:0% +either to the left or to the left or to + + + align:start position:0% +either to the left or to the left or to +the right uh so you just check all these + + align:start position:0% +the right uh so you just check all these + + + align:start position:0% +the right uh so you just check all these +things and then this is like a universal + + align:start position:0% +things and then this is like a universal + + + align:start position:0% +things and then this is like a universal +glue that can connect together the + + align:start position:0% +glue that can connect together the + + + align:start position:0% +glue that can connect together the +squares however you want both on the + + align:start position:0% +squares however you want both on the + + + align:start position:0% +squares however you want both on the +surface uh where they have to be + + align:start position:0% +surface uh where they have to be + + + align:start position:0% +surface uh where they have to be +connected originally and in the + + align:start position:0% +connected originally and in the + + + align:start position:0% +connected originally and in the +unfolding uh where you want to match + + align:start position:0% +unfolding uh where you want to match + + + align:start position:0% +unfolding uh where you want to match +some Square packing so a little bit of + + align:start position:0% +some Square packing so a little bit of + + + align:start position:0% +some Square packing so a little bit of +hand waving there lots of hand waving + + align:start position:0% +hand waving there lots of hand waving + + + align:start position:0% +hand waving there lots of hand waving +but in the end you get empty strong + + align:start position:0% +but in the end you get empty strong + + + align:start position:0% +but in the end you get empty strong +empty completeness of edge unfolding + + align:start position:0% +empty completeness of edge unfolding + + + align:start position:0% +empty completeness of edge unfolding +polyhedra uh any questions + + align:start position:0% + + + + align:start position:0% + +all right perfectly clear then um let's + + align:start position:0% +all right perfectly clear then um let's + + + align:start position:0% +all right perfectly clear then um let's +move to another puzzle this is called + + align:start position:0% +move to another puzzle this is called + + + align:start position:0% +move to another puzzle this is called +the snake Cube puzzle or the kubra + + align:start position:0% +the snake Cube puzzle or the kubra + + + align:start position:0% +the snake Cube puzzle or the kubra +puzzle um here is one instantiation of + + align:start position:0% +puzzle um here is one instantiation of + + + align:start position:0% +puzzle um here is one instantiation of +it so we have um it's a chain of + + align:start position:0% +it so we have um it's a chain of + + + align:start position:0% +it so we have um it's a chain of +blocks I try to unfold in a way that I + + align:start position:0% +blocks I try to unfold in a way that I + + + align:start position:0% +blocks I try to unfold in a way that I +can put it back together because it's + + align:start position:0% +can put it back together because it's + + + align:start position:0% +can put it back together because it's +actually quite tricky to solve um it's a + + align:start position:0% +actually quite tricky to solve um it's a + + + align:start position:0% +actually quite tricky to solve um it's a +chain of blocks and there's an elastic + + align:start position:0% +chain of blocks and there's an elastic + + + align:start position:0% +chain of blocks and there's an elastic +through the centers uh going through the + + align:start position:0% +through the centers uh going through the + + + align:start position:0% +through the centers uh going through the +center of the faces and so the result is + + align:start position:0% +center of the faces and so the result is + + + align:start position:0% +center of the faces and so the result is +uh you can't really pull the squares + + align:start position:0% +uh you can't really pull the squares + + + align:start position:0% +uh you can't really pull the squares +apart it's a pretty tight elastic but + + align:start position:0% +apart it's a pretty tight elastic but + + + align:start position:0% +apart it's a pretty tight elastic but +you can spin because from the elastics + + align:start position:0% +you can spin because from the elastics + + + align:start position:0% +you can spin because from the elastics +point of view these are all equally + + align:start position:0% +point of view these are all equally + + + align:start position:0% +point of view these are all equally +happy so you're basically told that and + + align:start position:0% +happy so you're basically told that and + + + align:start position:0% +happy so you're basically told that and +I I could also spin here but it doesn't + + align:start position:0% +I I could also spin here but it doesn't + + + align:start position:0% +I I could also spin here but it doesn't +do anything if I stop at a 90° angle so + + align:start position:0% +do anything if I stop at a 90° angle so + + + align:start position:0% +do anything if I stop at a 90° angle so +I'm forced to be straight here and then + + align:start position:0% +I'm forced to be straight here and then + + + align:start position:0% +I'm forced to be straight here and then +I'm forced to have a 90d turn and then + + align:start position:0% +I'm forced to have a 90d turn and then + + + align:start position:0% +I'm forced to have a 90d turn and then +I'm forced to go straight and then have + + align:start position:0% +I'm forced to go straight and then have + + + align:start position:0% +I'm forced to go straight and then have +a 90 degre turn and then go straight and + + align:start position:0% +a 90 degre turn and then go straight and + + + align:start position:0% +a 90 degre turn and then go straight and +then have a 90 degre turn uh here I have + + align:start position:0% +then have a 90 degre turn uh here I have + + + align:start position:0% +then have a 90 degre turn uh here I have +a a few 90 90° turns in a row and that's + + align:start position:0% +a a few 90 90° turns in a row and that's + + + align:start position:0% +a a few 90 90° turns in a row and that's +the general structure and can I still + + align:start position:0% +the general structure and can I still + + + align:start position:0% +the general structure and can I still +solve it maybe uh the goal is to get + + align:start position:0% +solve it maybe uh the goal is to get + + + align:start position:0% +solve it maybe uh the goal is to get +into a cube okay and there are a bunch + + align:start position:0% +into a cube okay and there are a bunch + + + align:start position:0% +into a cube okay and there are a bunch +of different versions plastic wood + + align:start position:0% +of different versions plastic wood + + + align:start position:0% +of different versions plastic wood +whatever this one is not solved and so I + + align:start position:0% +whatever this one is not solved and so I + + + align:start position:0% +whatever this one is not solved and so I +will not do so well but you get an idea + + align:start position:0% +will not do so well but you get an idea + + + align:start position:0% +will not do so well but you get an idea +of what it looks like in its sort of + + align:start position:0% +of what it looks like in its sort of + + + align:start position:0% +of what it looks like in its sort of +Flat state I can make it into a kind of + + align:start position:0% +Flat state I can make it into a kind of + + + align:start position:0% +Flat state I can make it into a kind of +staircase uh so in general this this + + align:start position:0% +staircase uh so in general this this + + + align:start position:0% +staircase uh so in general this this +puzzle is specified by sequence of + + align:start position:0% +puzzle is specified by sequence of + + + align:start position:0% +puzzle is specified by sequence of +lengths of straits and then in between + + align:start position:0% +lengths of straits and then in between + + + align:start position:0% +lengths of straits and then in between +those lengths are the 90° turns Okay so + + align:start position:0% +those lengths are the 90° turns Okay so + + + align:start position:0% +those lengths are the 90° turns Okay so +so that's the puzzle pretty simple + + align:start position:0% +so that's the puzzle pretty simple + + + align:start position:0% +so that's the puzzle pretty simple +specification and your goal is to fold + + align:start position:0% +specification and your goal is to fold + + + align:start position:0% +specification and your goal is to fold +into a cube you know how big the cube is + + align:start position:0% +into a cube you know how big the cube is + + + align:start position:0% +into a cube you know how big the cube is +you just take the number of little cubes + + align:start position:0% +you just take the number of little cubes + + + align:start position:0% +you just take the number of little cubes +and take the cube root um + + align:start position:0% +and take the cube root um + + + align:start position:0% +and take the cube root um +so uh this puzzle maybe goes uh is at + + align:start position:0% +so uh this puzzle maybe goes uh is at + + + align:start position:0% +so uh this puzzle maybe goes uh is at +least uh 1990 but could be older we + + align:start position:0% +least uh 1990 but could be older we + + + align:start position:0% +least uh 1990 but could be older we +don't know exactly um and this puzzle is + + align:start position:0% +don't know exactly um and this puzzle is + + + align:start position:0% +don't know exactly um and this puzzle is +also MP complete um and this proof is + + align:start position:0% +also MP complete um and this proof is + + + align:start position:0% +also MP complete um and this proof is +also complicated so we won't see all the + + align:start position:0% +also complicated so we won't see all the + + + align:start position:0% +also complicated so we won't see all the +details but this one we'll probably see + + align:start position:0% +details but this one we'll probably see + + + align:start position:0% +details but this one we'll probably see +a little bit clearer um this is a proof + + align:start position:0% +a little bit clearer um this is a proof + + + align:start position:0% +a little bit clearer um this is a proof +by in in particular the three of us and + + align:start position:0% +by in in particular the three of us and + + + align:start position:0% +by in in particular the three of us and +and Marty in the back so for all four of + + align:start position:0% +and Marty in the back so for all four of + + + align:start position:0% +and Marty in the back so for all four of +us um and let's see so this doesn't look + + align:start position:0% +us um and let's see so this doesn't look + + + align:start position:0% +us um and let's see so this doesn't look +like a cube uh so let's before we try to + + align:start position:0% +like a cube uh so let's before we try to + + + align:start position:0% +like a cube uh so let's before we try to +solve the problem of folding into a cube + + align:start position:0% +solve the problem of folding into a cube + + + align:start position:0% +solve the problem of folding into a cube +shape let's suppose um I give you one of + + align:start position:0% +shape let's suppose um I give you one of + + + align:start position:0% +shape let's suppose um I give you one of +these chains and I want to can it fold + + align:start position:0% +these chains and I want to can it fold + + + align:start position:0% +these chains and I want to can it fold +into this shape let's say this is the + + align:start position:0% +into this shape let's say this is the + + + align:start position:0% +into this shape let's say this is the +target so it's a big box down here I + + align:start position:0% +target so it's a big box down here I + + + align:start position:0% +target so it's a big box down here I +think we call the Hub and then there are + + align:start position:0% +think we call the Hub and then there are + + + align:start position:0% +think we call the Hub and then there are +these spokes + + align:start position:0% +these spokes + + + align:start position:0% +these spokes +or just big boxes long boxes sticking + + align:start position:0% +or just big boxes long boxes sticking + + + align:start position:0% +or just big boxes long boxes sticking +out of the Hub there's a there's a hole + + align:start position:0% +out of the Hub there's a there's a hole + + + align:start position:0% +out of the Hub there's a there's a hole +here there's they're connected to the + + align:start position:0% +here there's they're connected to the + + + align:start position:0% +here there's they're connected to the +main structure and you want to fold + + align:start position:0% +main structure and you want to fold + + + align:start position:0% +main structure and you want to fold +that and uh let's see so the the the big + + align:start position:0% +that and uh let's see so the the the big + + + align:start position:0% +that and uh let's see so the the the big +idea we're reducing from three partition + + align:start position:0% +idea we're reducing from three partition + + + align:start position:0% +idea we're reducing from three partition +here we're going to represent a number + + align:start position:0% +here we're going to represent a number + + + align:start position:0% +here we're going to represent a number +AI as uh a zigzag well not sorry I + + align:start position:0% +AI as uh a zigzag well not sorry I + + + align:start position:0% +AI as uh a zigzag well not sorry I +shouldn't call it a zigzag uh but we + + align:start position:0% +shouldn't call it a zigzag uh but we + + + align:start position:0% +shouldn't call it a zigzag uh but we +have a really long bar then a length one + + align:start position:0% +have a really long bar then a length one + + + align:start position:0% +have a really long bar then a length one +bar and then a really long bar and a + + align:start position:0% +bar and then a really long bar and a + + + align:start position:0% +bar and then a really long bar and a +length one bar I'm drawing sort of the + + align:start position:0% +length one bar I'm drawing sort of the + + + align:start position:0% +length one bar I'm drawing sort of the +thinned version this is really a little + + align:start position:0% +thinned version this is really a little + + + align:start position:0% +thinned version this is really a little +Cube this is a little Cube these are + + align:start position:0% +Cube this is a little Cube these are + + + align:start position:0% +Cube this is a little Cube these are +lots of Cubes uh huge number of Cubes + + align:start position:0% +lots of Cubes uh huge number of Cubes + + + align:start position:0% +lots of Cubes uh huge number of Cubes +okay uh so that's really really big um + + align:start position:0% +okay uh so that's really really big um + + + align:start position:0% +okay uh so that's really really big um +so big that the only place it could fit + + align:start position:0% +so big that the only place it could fit + + + align:start position:0% +so big that the only place it could fit +is down one of these spokes so of course + + align:start position:0% +is down one of these spokes so of course + + + align:start position:0% +is down one of these spokes so of course +the idea is that these represent our + + align:start position:0% +the idea is that these represent our + + + align:start position:0% +the idea is that these represent our +triples whose sum is equal to + + align:start position:0% +triples whose sum is equal to + + + align:start position:0% +triples whose sum is equal to +T um and so we have to take these things + + align:start position:0% +T um and so we have to take these things + + + align:start position:0% +T um and so we have to take these things +and because these are are so short you + + align:start position:0% +and because these are are so short you + + + align:start position:0% +and because these are are so short you +can't like go out of one Hub and like + + align:start position:0% +can't like go out of one Hub and like + + + align:start position:0% +can't like go out of one Hub and like +jump to the next one because there's a a + + align:start position:0% +jump to the next one because there's a a + + + align:start position:0% +jump to the next one because there's a a +non a gap there that's bigger than one + + align:start position:0% +non a gap there that's bigger than one + + + align:start position:0% +non a gap there that's bigger than one +so once you commit to having one of + + align:start position:0% +so once you commit to having one of + + + align:start position:0% +so once you commit to having one of +these long bars into one of these + + align:start position:0% +these long bars into one of these + + + align:start position:0% +these long bars into one of these +Pockets then all of them have to go into + + align:start position:0% +Pockets then all of them have to go into + + + align:start position:0% +Pockets then all of them have to go into +the pocket so this is a in general big + + align:start position:0% +the pocket so this is a in general big + + + align:start position:0% +the pocket so this is a in general big +issue with three partition proofs is you + + align:start position:0% +issue with three partition proofs is you + + + align:start position:0% +issue with three partition proofs is you +want to represent the number AI in some + + align:start position:0% +want to represent the number AI in some + + + align:start position:0% +want to represent the number AI in some +way that cannot be uh it's not divisible + + align:start position:0% +way that cannot be uh it's not divisible + + + align:start position:0% +way that cannot be uh it's not divisible +if you could take I Ai and split it into + + align:start position:0% +if you could take I Ai and split it into + + + align:start position:0% +if you could take I Ai and split it into +two parts then the packing problem + + align:start position:0% +two parts then the packing problem + + + align:start position:0% +two parts then the packing problem +becomes trivial youl split everything + + align:start position:0% +becomes trivial youl split everything + + + align:start position:0% +becomes trivial youl split everything +into units or something um so we have to + + align:start position:0% +into units or something um so we have to + + + align:start position:0% +into units or something um so we have to +make sure AI remains a single Chunk we + + align:start position:0% +make sure AI remains a single Chunk we + + + align:start position:0% +make sure AI remains a single Chunk we +are of course encoding AI in un here + + align:start position:0% +are of course encoding AI in un here + + + align:start position:0% +are of course encoding AI in un here +because we have one Long Bar per each AI + + align:start position:0% +because we have one Long Bar per each AI + + + align:start position:0% +because we have one Long Bar per each AI +but for three partition un is okay um + + align:start position:0% +but for three partition un is okay um + + + align:start position:0% +but for three partition un is okay um +there's some things going on here a + + align:start position:0% +there's some things going on here a + + + align:start position:0% +there's some things going on here a +little bit weird uh so you see this + + align:start position:0% +little bit weird uh so you see this + + + align:start position:0% +little bit weird uh so you see this +thing is occupying the full length and + + align:start position:0% +thing is occupying the full length and + + + align:start position:0% +thing is occupying the full length and +the length here is going to be eight + + align:start position:0% +the length here is going to be eight + + + align:start position:0% +the length here is going to be eight +times the target sum instead of just the + + align:start position:0% +times the target sum instead of just the + + + align:start position:0% +times the target sum instead of just the +target sum and we're multiplying this by + + align:start position:0% +target sum and we're multiplying this by + + + align:start position:0% +target sum and we're multiplying this by +eight so those are equal we're fine + + align:start position:0% +eight so those are equal we're fine + + + align:start position:0% +eight so those are equal we're fine +there there's a reason for the eight + + align:start position:0% +there there's a reason for the eight + + + align:start position:0% +there there's a reason for the eight +which we will get to okay now um like + + align:start position:0% +which we will get to okay now um like + + + align:start position:0% +which we will get to okay now um like +the previous proof The Edge unfolding + + align:start position:0% +the previous proof The Edge unfolding + + + align:start position:0% +the previous proof The Edge unfolding +polyhedra we have these great units and + + align:start position:0% +polyhedra we have these great units and + + + align:start position:0% +polyhedra we have these great units and +we just like them to be free floating + + align:start position:0% +we just like them to be free floating + + + align:start position:0% +we just like them to be free floating +and if you if you generalize this puzzle + + align:start position:0% +and if you if you generalize this puzzle + + + align:start position:0% +and if you if you generalize this puzzle +a little bit and say well actually uh I + + align:start position:0% +a little bit and say well actually uh I + + + align:start position:0% +a little bit and say well actually uh I +don't just have one chain I have two + + align:start position:0% +don't just have one chain I have two + + + align:start position:0% +don't just have one chain I have two +chains and or I have n chains and + + align:start position:0% +chains and or I have n chains and + + + align:start position:0% +chains and or I have n chains and +together collectively they have to fold + + align:start position:0% +together collectively they have to fold + + + align:start position:0% +together collectively they have to fold +into this shape then we're done except + + align:start position:0% +into this shape then we're done except + + + align:start position:0% +into this shape then we're done except +you would remove the Box the big uh the + + align:start position:0% +you would remove the Box the big uh the + + + align:start position:0% +you would remove the Box the big uh the +box over + + align:start position:0% +box over + + + align:start position:0% +box over +here uh because then these guys just + + align:start position:0% +here uh because then these guys just + + + align:start position:0% +here uh because then these guys just +somehow have to be assigned to these + + align:start position:0% +somehow have to be assigned to these + + + align:start position:0% +somehow have to be assigned to these +little pockets and we're happy okay um + + align:start position:0% +little pockets and we're happy okay um + + + align:start position:0% +little pockets and we're happy okay um +all of these numbers although again not + + align:start position:0% +all of these numbers although again not + + + align:start position:0% +all of these numbers although again not +drawn to scale all of these numbers are + + align:start position:0% +drawn to scale all of these numbers are + + + align:start position:0% +drawn to scale all of these numbers are +much smaller than huge so you can't like + + align:start position:0% +much smaller than huge so you can't like + + + align:start position:0% +much smaller than huge so you can't like +take this guy and put it here even + + align:start position:0% +take this guy and put it here even + + + align:start position:0% +take this guy and put it here even +though in this picture it looks like you + + align:start position:0% +though in this picture it looks like you + + + align:start position:0% +though in this picture it looks like you +might be able to all right so uh the + + align:start position:0% +might be able to all right so uh the + + + align:start position:0% +might be able to all right so uh the +issue is now we want to connect this + + align:start position:0% +issue is now we want to connect this + + + align:start position:0% +issue is now we want to connect this +together into one big chain we have + + align:start position:0% +together into one big chain we have + + + align:start position:0% +together into one big chain we have +these units for each eye uh we have one + + align:start position:0% +these units for each eye uh we have one + + + align:start position:0% +these units for each eye uh we have one +of these units that's cool uh and we + + align:start position:0% +of these units that's cool uh and we + + + align:start position:0% +of these units that's cool uh and we +want to attach them together in a way + + align:start position:0% +want to attach them together in a way + + + align:start position:0% +want to attach them together in a way +that is super flexible just like the + + align:start position:0% +that is super flexible just like the + + + align:start position:0% +that is super flexible just like the +atoms we had before um now we're going + + align:start position:0% +atoms we had before um now we're going + + + align:start position:0% +atoms we had before um now we're going +to use something which we call the + + align:start position:0% +to use something which we call the + + + align:start position:0% +to use something which we call the +zigzag that's why I didn't want to call + + align:start position:0% +zigzag that's why I didn't want to call + + + align:start position:0% +zigzag that's why I didn't want to call +this a zigzag um this is all unit + + align:start position:0% +this a zigzag um this is all unit + + + align:start position:0% +this a zigzag um this is all unit +segments so you have 90 degree turn 90° + + align:start position:0% +segments so you have 90 degree turn 90° + + + align:start position:0% +segments so you have 90 degree turn 90° +turn 90° turn 90 degre turn no straights + + align:start position:0% +turn 90° turn 90 degre turn no straights + + + align:start position:0% +turn 90° turn 90 degre turn no straights +this turns out to be Universal in a + + align:start position:0% +this turns out to be Universal in a + + + align:start position:0% +this turns out to be Universal in a +strong sense it can fold into + + align:start position:0% +strong sense it can fold into + + + align:start position:0% +strong sense it can fold into +anything um and so we can use it to + + align:start position:0% +anything um and so we can use it to + + + align:start position:0% +anything um and so we can use it to +connect these parts together so what + + align:start position:0% +connect these parts together so what + + + align:start position:0% +connect these parts together so what +we're going to do is have + + align:start position:0% +we're going to do is have + + + align:start position:0% +we're going to do is have +uh the A1 Gadget then we're going to + + align:start position:0% +uh the A1 Gadget then we're going to + + + align:start position:0% +uh the A1 Gadget then we're going to +have a whole bunch of zigzags so you can + + align:start position:0% +have a whole bunch of zigzags so you can + + + align:start position:0% +have a whole bunch of zigzags so you can +go wherever you need to go then we'll + + align:start position:0% +go wherever you need to go then we'll + + + align:start position:0% +go wherever you need to go then we'll +have the A2 Gadget and then we'll have a + + align:start position:0% +have the A2 Gadget and then we'll have a + + + align:start position:0% +have the A2 Gadget and then we'll have a +the universal zigzag Gadget uh for a + + align:start position:0% +the universal zigzag Gadget uh for a + + + align:start position:0% +the universal zigzag Gadget uh for a +long length of it and then the A3 and + + align:start position:0% +long length of it and then the A3 and + + + align:start position:0% +long length of it and then the A3 and +then alternating between zigzags and the + + align:start position:0% +then alternating between zigzags and the + + + align:start position:0% +then alternating between zigzags and the +AI and at the end we'll have enough + + align:start position:0% +AI and at the end we'll have enough + + + align:start position:0% +AI and at the end we'll have enough +zigzag uh that we can fill all this sort + + align:start position:0% +zigzag uh that we can fill all this sort + + + align:start position:0% +zigzag uh that we can fill all this sort +of extra garbage space but we will use + + align:start position:0% +of extra garbage space but we will use + + + align:start position:0% +of extra garbage space but we will use +this garbage space in order to Route + + align:start position:0% +this garbage space in order to Route + + + align:start position:0% +this garbage space in order to Route +around so maybe a1's going to go here + + align:start position:0% +around so maybe a1's going to go here + + + align:start position:0% +around so maybe a1's going to go here +and so we do the this thing + + align:start position:0% +and so we do the this thing + + + align:start position:0% +and so we do the this thing +this um yeah looks like some kind of + + align:start position:0% +this um yeah looks like some kind of + + + align:start position:0% +this um yeah looks like some kind of +cooker uh we go back and forth like that + + align:start position:0% +cooker uh we go back and forth like that + + + align:start position:0% +cooker uh we go back and forth like that +uh then we'll have the zigzag we say + + align:start position:0% +uh then we'll have the zigzag we say + + + align:start position:0% +uh then we'll have the zigzag we say +Okay I want to go over here next and + + align:start position:0% +Okay I want to go over here next and + + + align:start position:0% +Okay I want to go over here next and +then we'll do A2 there and then we'll + + align:start position:0% +then we'll do A2 there and then we'll + + + align:start position:0% +then we'll do A2 there and then we'll +route over here and because this is in + + align:start position:0% +route over here and because this is in + + + align:start position:0% +route over here and because this is in +3D Crossings are not an issue I can just + + align:start position:0% +3D Crossings are not an issue I can just + + + align:start position:0% +3D Crossings are not an issue I can just +go out into the third dimension um we + + align:start position:0% +go out into the third dimension um we + + + align:start position:0% +go out into the third dimension um we +don't need much of a third dimension + + align:start position:0% +don't need much of a third dimension + + + align:start position:0% +don't need much of a third dimension +Eight is Enough uh you can just enough + + align:start position:0% +Eight is Enough uh you can just enough + + + align:start position:0% +Eight is Enough uh you can just enough +to go over each + + align:start position:0% +to go over each + + + align:start position:0% +to go over each +other okay and then at the end uh we're + + align:start position:0% +other okay and then at the end uh we're + + + align:start position:0% +other okay and then at the end uh we're +going to fill in all the space with this + + align:start position:0% +going to fill in all the space with this + + + align:start position:0% +going to fill in all the space with this +zigzag so let's talk about the + + align:start position:0% +zigzag so let's talk about the + + + align:start position:0% +zigzag so let's talk about the +zigzag uh what we claim there a couple + + align:start position:0% +zigzag uh what we claim there a couple + + + align:start position:0% +zigzag uh what we claim there a couple +different senses in which it's + + align:start position:0% +different senses in which it's + + + align:start position:0% +different senses in which it's +Universal um but the the key idea are + + align:start position:0% +Universal um but the the key idea are + + + align:start position:0% +Universal um but the the key idea are +these sets of gadgets uh so we're + + align:start position:0% +these sets of gadgets uh so we're + + + align:start position:0% +these sets of gadgets uh so we're +drawing here a 2X twox + + align:start position:0% +drawing here a 2X twox + + + align:start position:0% +drawing here a 2X twox +two uh cube made up out of you know uh + + align:start position:0% +two uh cube made up out of you know uh + + + align:start position:0% +two uh cube made up out of you know uh +eight little + + align:start position:0% +eight little + + + align:start position:0% +eight little +cubes and uh if you look at the uh what + + align:start position:0% +cubes and uh if you look at the uh what + + + align:start position:0% +cubes and uh if you look at the uh what +we've drawn here is the elastic that + + align:start position:0% +we've drawn here is the elastic that + + + align:start position:0% +we've drawn here is the elastic that +goes through the centers of the cubes + + align:start position:0% +goes through the centers of the cubes + + + align:start position:0% +goes through the centers of the cubes +and notice it turns 90° at every at + + align:start position:0% +and notice it turns 90° at every at + + + align:start position:0% +and notice it turns 90° at every at +every voxel at every little Cube um so + + align:start position:0% +every voxel at every little Cube um so + + + align:start position:0% +every voxel at every little Cube um so +that's this is part of these are zigzag + + align:start position:0% +that's this is part of these are zigzag + + + align:start position:0% +that's this is part of these are zigzag +constructions so um what we want to say + + align:start position:0% +constructions so um what we want to say + + + align:start position:0% +constructions so um what we want to say +is that if you sort of uh so one sense + + align:start position:0% +is that if you sort of uh so one sense + + + align:start position:0% +is that if you sort of uh so one sense +of universality is that the zigzag uh + + align:start position:0% +of universality is that the zigzag uh + + + align:start position:0% +of universality is that the zigzag uh +structure can fold into any polycube + + align:start position:0% +structure can fold into any polycube + + + align:start position:0% +structure can fold into any polycube +structure poly cube is the 3D + + align:start position:0% +structure poly cube is the 3D + + + align:start position:0% +structure poly cube is the 3D +generalization of polyomino that we saw + + align:start position:0% +generalization of polyomino that we saw + + + align:start position:0% +generalization of polyomino that we saw +last time um from polyomino + + align:start position:0% +last time um from polyomino + + + align:start position:0% +last time um from polyomino +packing uh that's not true but if you + + align:start position:0% +packing uh that's not true but if you + + + align:start position:0% +packing uh that's not true but if you +take any poly Cube structure and you + + align:start position:0% +take any poly Cube structure and you + + + align:start position:0% +take any poly Cube structure and you +just scale it by a factor of two so you + + align:start position:0% +just scale it by a factor of two so you + + + align:start position:0% +just scale it by a factor of two so you +replace every cube with a 2X two x two + + align:start position:0% +replace every cube with a 2X two x two + + + align:start position:0% +replace every cube with a 2X two x two +grid like this picture then it's still + + align:start position:0% +grid like this picture then it's still + + + align:start position:0% +grid like this picture then it's still +not true but it's better um so what's + + align:start position:0% +not true but it's better um so what's + + + align:start position:0% +not true but it's better um so what's +true at that point is if you take any + + align:start position:0% +true at that point is if you take any + + + align:start position:0% +true at that point is if you take any +path of 2x two x two cubes this is what + + align:start position:0% +path of 2x two x two cubes this is what + + + align:start position:0% +path of 2x two x two cubes this is what +we would call a hamiltonian shape + + align:start position:0% +we would call a hamiltonian shape + + + align:start position:0% +we would call a hamiltonian shape +because there's one path that visits + + align:start position:0% +because there's one path that visits + + + align:start position:0% +because there's one path that visits +everything with no Collision so it has + + align:start position:0% +everything with no Collision so it has + + + align:start position:0% +everything with no Collision so it has +to be a path that does not hit itself in + + align:start position:0% +to be a path that does not hit itself in + + + align:start position:0% +to be a path that does not hit itself in +3D um then you can follow these Gadgets + + align:start position:0% +3D um then you can follow these Gadgets + + + align:start position:0% +3D um then you can follow these Gadgets +in order to make any turns you need to + + align:start position:0% +in order to make any turns you need to + + + align:start position:0% +in order to make any turns you need to +do or you can go straight uh everything + + align:start position:0% +do or you can go straight uh everything + + + align:start position:0% +do or you can go straight uh everything +is possible uh we'll talk a little bit + + align:start position:0% +is possible uh we'll talk a little bit + + + align:start position:0% +is possible uh we'll talk a little bit +more about that in a moment so 2x2 x two + + align:start position:0% +more about that in a moment so 2x2 x two + + + align:start position:0% +more about that in a moment so 2x2 x two +refinement meaning scaling everything by + + align:start position:0% +refinement meaning scaling everything by + + + align:start position:0% +refinement meaning scaling everything by +a factor of two uh allows the zigzag to + + align:start position:0% +a factor of two uh allows the zigzag to + + + align:start position:0% +a factor of two uh allows the zigzag to +make any hamiltonian shape scaled by two + + align:start position:0% +make any hamiltonian shape scaled by two + + + align:start position:0% +make any hamiltonian shape scaled by two +um but that's hamiltonian shapes now + + align:start position:0% +um but that's hamiltonian shapes now + + + align:start position:0% +um but that's hamiltonian shapes now +conveniently there's this theorem which + + align:start position:0% +conveniently there's this theorem which + + + align:start position:0% +conveniently there's this theorem which +is used a lot in computational geometry + + align:start position:0% +is used a lot in computational geometry + + + align:start position:0% +is used a lot in computational geometry +and we use it in this hardness proof uh + + align:start position:0% +and we use it in this hardness proof uh + + + align:start position:0% +and we use it in this hardness proof uh +that if you take any shape and you + + align:start position:0% +that if you take any shape and you + + + align:start position:0% +that if you take any shape and you +refine it by 2x 2 by two or you scale by + + align:start position:0% +refine it by 2x 2 by two or you scale by + + + align:start position:0% +refine it by 2x 2 by two or you scale by +a factor of two then it becomes + + align:start position:0% +a factor of two then it becomes + + + align:start position:0% +a factor of two then it becomes +hamiltonian by a similar kind of Gadget + + align:start position:0% +hamiltonian by a similar kind of Gadget + + + align:start position:0% +hamiltonian by a similar kind of Gadget +construction although it's easier if you + + align:start position:0% +construction although it's easier if you + + + align:start position:0% +construction although it's easier if you +just want hamiltonian paths you don't + + align:start position:0% +just want hamiltonian paths you don't + + + align:start position:0% +just want hamiltonian paths you don't +care about where you where you're + + align:start position:0% +care about where you where you're + + + align:start position:0% +care about where you where you're +turning and where you're not turning uh + + align:start position:0% +turning and where you're not turning uh + + + align:start position:0% +turning and where you're not turning uh +so that's a pretty easy proof left as an + + align:start position:0% +so that's a pretty easy proof left as an + + + align:start position:0% +so that's a pretty easy proof left as an +exercise to you um and sort of an aside + + align:start position:0% +exercise to you um and sort of an aside + + + align:start position:0% +exercise to you um and sort of an aside +from this this issue so we take any + + align:start position:0% +from this this issue so we take any + + + align:start position:0% +from this this issue so we take any +shape we 2 by two by two refine it we + + align:start position:0% +shape we 2 by two by two refine it we + + + align:start position:0% +shape we 2 by two by two refine it we +make it hamiltonian then we 2 by two + + align:start position:0% +make it hamiltonian then we 2 by two + + + align:start position:0% +make it hamiltonian then we 2 by two +refine it again in total 4x4x4 + + align:start position:0% +refine it again in total 4x4x4 + + + align:start position:0% +refine it again in total 4x4x4 +refinement and then uh zigzag path can + + align:start position:0% +refinement and then uh zigzag path can + + + align:start position:0% +refinement and then uh zigzag path can +make that poly Cube shape this is for + + align:start position:0% +make that poly Cube shape this is for + + + align:start position:0% +make that poly Cube shape this is for +any poly Cube so that's cool now uh I'll + + align:start position:0% +any poly Cube so that's cool now uh I'll + + + align:start position:0% +any poly Cube so that's cool now uh I'll +mention here in this proof one of the + + align:start position:0% +mention here in this proof one of the + + + align:start position:0% +mention here in this proof one of the +issues um which we'll see a bunch of + + align:start position:0% +issues um which we'll see a bunch of + + + align:start position:0% +issues um which we'll see a bunch of +times I'm just going to mention it here + + align:start position:0% +times I'm just going to mention it here + + + align:start position:0% +times I'm just going to mention it here +is uh we have a parody issue because the + + align:start position:0% +is uh we have a parody issue because the + + + align:start position:0% +is uh we have a parody issue because the +uh the cubicle grid + + align:start position:0% +uh the cubicle grid + + + align:start position:0% +uh the cubicle grid +is uh two colorable right you can + + align:start position:0% +is uh two colorable right you can + + + align:start position:0% +is uh two colorable right you can +checkerboard the the 3D grid of squares + + align:start position:0% +checkerboard the the 3D grid of squares + + + align:start position:0% +checkerboard the the 3D grid of squares +um and so what that means is every time + + align:start position:0% +um and so what that means is every time + + + align:start position:0% +um and so what that means is every time +you go from one Cube on the grid to + + align:start position:0% +you go from one Cube on the grid to + + + align:start position:0% +you go from one Cube on the grid to +another Cube on the grid you're + + align:start position:0% +another Cube on the grid you're + + + align:start position:0% +another Cube on the grid you're +switching parody so if you checkerboard + + align:start position:0% +switching parody so if you checkerboard + + + align:start position:0% +switching parody so if you checkerboard +the 3D space uh black and white it was + + align:start position:0% +the 3D space uh black and white it was + + + align:start position:0% +the 3D space uh black and white it was +going from white to black then black to + + align:start position:0% +going from white to black then black to + + + align:start position:0% +going from white to black then black to +white then black to white then oh sorry + + align:start position:0% +white then black to white then oh sorry + + + align:start position:0% +white then black to white then oh sorry +alternating black and white um and + + align:start position:0% +alternating black and white um and + + + align:start position:0% +alternating black and white um and +easier to do than to say and um so + + align:start position:0% +easier to do than to say and um so + + + align:start position:0% +easier to do than to say and um so +that's a constraint so for example it is + + align:start position:0% +that's a constraint so for example it is + + + align:start position:0% +that's a constraint so for example it is +impossible to in a 2 by two by two thing + + align:start position:0% +impossible to in a 2 by two by two thing + + + align:start position:0% +impossible to in a 2 by two by two thing +to uh let's see + + align:start position:0% +to uh let's see + + + align:start position:0% +to uh let's see +enter from this Cube the front Cube and + + align:start position:0% +enter from this Cube the front Cube and + + + align:start position:0% +enter from this Cube the front Cube and +exit from this one uh just by a counting + + align:start position:0% +exit from this one uh just by a counting + + + align:start position:0% +exit from this one uh just by a counting +argument so you start let's say this is + + align:start position:0% +argument so you start let's say this is + + + align:start position:0% +argument so you start let's say this is +a Black Cube this one also a black Cube + + align:start position:0% +a Black Cube this one also a black Cube + + + align:start position:0% +a Black Cube this one also a black Cube +and so you start black and then you + + align:start position:0% +and so you start black and then you + + + align:start position:0% +and so you start black and then you +alternate black white black white and + + align:start position:0% +alternate black white black white and + + + align:start position:0% +alternate black white black white and +there's eight things to visit and you + + align:start position:0% +there's eight things to visit and you + + + align:start position:0% +there's eight things to visit and you +want to end black that's not possible + + align:start position:0% +want to end black that's not possible + + + align:start position:0% +want to end black that's not possible +you have to end white so if you enter on + + align:start position:0% +you have to end white so if you enter on + + + align:start position:0% +you have to end white so if you enter on +a black Cube you will leave on a white + + align:start position:0% +a black Cube you will leave on a white + + + align:start position:0% +a black Cube you will leave on a white +Cube and if you enter on a white Cube + + align:start position:0% +Cube and if you enter on a white Cube + + + align:start position:0% +Cube and if you enter on a white Cube +you leave on a black Cube so um that's a + + align:start position:0% +you leave on a black Cube so um that's a + + + align:start position:0% +you leave on a black Cube so um that's a +constraint doesn't really get in the way + + align:start position:0% +constraint doesn't really get in the way + + + align:start position:0% +constraint doesn't really get in the way +here but it's something you have to keep + + align:start position:0% +here but it's something you have to keep + + + align:start position:0% +here but it's something you have to keep +track of and the theorem wouldn't be + + align:start position:0% +track of and the theorem wouldn't be + + + align:start position:0% +track of and the theorem wouldn't be +what you'd like to say is well I can + + align:start position:0% +what you'd like to say is well I can + + + align:start position:0% +what you'd like to say is well I can +enter from any Cube and leave from any + + align:start position:0% +enter from any Cube and leave from any + + + align:start position:0% +enter from any Cube and leave from any +Cube and uh you could actually prove + + align:start position:0% +Cube and uh you could actually prove + + + align:start position:0% +Cube and uh you could actually prove +that by induction except the base case + + align:start position:0% +that by induction except the base case + + + align:start position:0% +that by induction except the base case +would be wrong so this is something to + + align:start position:0% +would be wrong so this is something to + + + align:start position:0% +would be wrong so this is something to +be careful about this is the base case + + align:start position:0% +be careful about this is the base case + + + align:start position:0% +be careful about this is the base case +this is one Cube can I enter from + + align:start position:0% +this is one Cube can I enter from + + + align:start position:0% +this is one Cube can I enter from +anywhere one 2X 2 by two super Cube can + + align:start position:0% +anywhere one 2X 2 by two super Cube can + + + align:start position:0% +anywhere one 2X 2 by two super Cube can +I enter anywhere leave anywhere the + + align:start position:0% +I enter anywhere leave anywhere the + + + align:start position:0% +I enter anywhere leave anywhere the +answer is no but I can enter and exit + + align:start position:0% +answer is no but I can enter and exit + + + align:start position:0% +answer is no but I can enter and exit +anywhere that have the right parity so + + align:start position:0% +anywhere that have the right parity so + + + align:start position:0% +anywhere that have the right parity so +if the entrance Cube and the exit cubes + + align:start position:0% +if the entrance Cube and the exit cubes + + + align:start position:0% +if the entrance Cube and the exit cubes +have opposite parity then this is + + align:start position:0% +have opposite parity then this is + + + align:start position:0% +have opposite parity then this is +actually all of the cases uh these four + + align:start position:0% +actually all of the cases uh these four + + + align:start position:0% +actually all of the cases uh these four +are where the entrance and exit Cube are + + align:start position:0% +are where the entrance and exit Cube are + + + align:start position:0% +are where the entrance and exit Cube are +um adjacent to each other and these uh + + align:start position:0% +um adjacent to each other and these uh + + + align:start position:0% +um adjacent to each other and these uh +two cases are where they're opposite + + align:start position:0% +two cases are where they're opposite + + + align:start position:0% +two cases are where they're opposite +from each other not touching um and + + align:start position:0% +from each other not touching um and + + + align:start position:0% +from each other not touching um and +that's all the cases with with all the + + align:start position:0% +that's all the cases with with all the + + + align:start position:0% +that's all the cases with with all the +rotations and Reflections um so once you + + align:start position:0% +rotations and Reflections um so once you + + + align:start position:0% +rotations and Reflections um so once you +prove that the base case is actually + + align:start position:0% +prove that the base case is actually + + + align:start position:0% +prove that the base case is actually +really easy to do by induction you just + + align:start position:0% +really easy to do by induction you just + + + align:start position:0% +really easy to do by induction you just +are essentially pasting all of these + + align:start position:0% +are essentially pasting all of these + + + align:start position:0% +are essentially pasting all of these +things together to make any + + align:start position:0% +things together to make any + + + align:start position:0% +things together to make any +path uh and then we can make any + + align:start position:0% +path uh and then we can make any + + + align:start position:0% +path uh and then we can make any +hamiltonian shape then further + + align:start position:0% +hamiltonian shape then further + + + align:start position:0% +hamiltonian shape then further +refinement we can any shape becomes + + align:start position:0% +refinement we can any shape becomes + + + align:start position:0% +refinement we can any shape becomes +hamiltonian so that's how we prove + + align:start position:0% +hamiltonian so that's how we prove + + + align:start position:0% +hamiltonian so that's how we prove +zigzags are Universal and this uh + + align:start position:0% +zigzags are Universal and this uh + + + align:start position:0% +zigzags are Universal and this uh +connects together uh all of these + + align:start position:0% +connects together uh all of these + + + align:start position:0% +connects together uh all of these +gadgets so there's really two Gadgets in + + align:start position:0% +gadgets so there's really two Gadgets in + + + align:start position:0% +gadgets so there's really two Gadgets in +this proof the AI gadgets there's n of n + + align:start position:0% +this proof the AI gadgets there's n of n + + + align:start position:0% +this proof the AI gadgets there's n of n +copies of that and the zigzag Gadget + + align:start position:0% +copies of that and the zigzag Gadget + + + align:start position:0% +copies of that and the zigzag Gadget +there's n copies of that as well and + + align:start position:0% +there's n copies of that as well and + + + align:start position:0% +there's n copies of that as well and +that now there are some details to check + + align:start position:0% +that now there are some details to check + + + align:start position:0% +that now there are some details to check +here of course that the zigzag gadgets + + align:start position:0% +here of course that the zigzag gadgets + + + align:start position:0% +here of course that the zigzag gadgets +can actually uh navigate around uh and + + align:start position:0% +can actually uh navigate around uh and + + + align:start position:0% +can actually uh navigate around uh and +not across each other with height eight + + align:start position:0% +not across each other with height eight + + + align:start position:0% +not across each other with height eight +um and that at the end you can fill all + + align:start position:0% +um and that at the end you can fill all + + + align:start position:0% +um and that at the end you can fill all +the blank space if you're just organized + + align:start position:0% +the blank space if you're just organized + + + align:start position:0% +the blank space if you're just organized +about you Traverse each of the AIS uh + + align:start position:0% +about you Traverse each of the AIS uh + + + align:start position:0% +about you Traverse each of the AIS uh +and where you put the blank space I + + align:start position:0% +and where you put the blank space I + + + align:start position:0% +and where you put the blank space I +think we just leave some Headroom so you + + align:start position:0% +think we just leave some Headroom so you + + + align:start position:0% +think we just leave some Headroom so you +can just go up walk over to where all + + align:start position:0% +can just go up walk over to where all + + + align:start position:0% +can just go up walk over to where all +the blank space is just sered to a scan + + align:start position:0% +the blank space is just sered to a scan + + + align:start position:0% +the blank space is just sered to a scan +line traversal wherever there's Blank + + align:start position:0% +line traversal wherever there's Blank + + + align:start position:0% +line traversal wherever there's Blank +Space you eat it up with your zigzag at + + align:start position:0% +Space you eat it up with your zigzag at + + + align:start position:0% +Space you eat it up with your zigzag at +the end so all what this does is it lets + + align:start position:0% +the end so all what this does is it lets + + + align:start position:0% +the end so all what this does is it lets +the AIS move around completely freely uh + + align:start position:0% +the AIS move around completely freely uh + + + align:start position:0% +the AIS move around completely freely uh +there's no there shouldn't be any + + align:start position:0% +there's no there shouldn't be any + + + align:start position:0% +there's no there shouldn't be any +constraints on how the AIS are assigned + + align:start position:0% +constraints on how the AIS are assigned + + + align:start position:0% +constraints on how the AIS are assigned +to these uh Pockets because we want + + align:start position:0% +to these uh Pockets because we want + + + align:start position:0% +to these uh Pockets because we want +every solution to the three partition + + align:start position:0% +every solution to the three partition + + + align:start position:0% +every solution to the three partition +instance to work here and the zigzags + + align:start position:0% +instance to work here and the zigzags + + + align:start position:0% +instance to work here and the zigzags +let us do that because they're so + + align:start position:0% +let us do that because they're so + + + align:start position:0% +let us do that because they're so +Universal + + align:start position:0% +Universal + + + align:start position:0% +Universal +cool so I think that's what I wanted to + + align:start position:0% +cool so I think that's what I wanted to + + + align:start position:0% +cool so I think that's what I wanted to +say about this proof let me double check + + align:start position:0% +say about this proof let me double check + + + align:start position:0% +say about this proof let me double check +my + + align:start position:0% +my + + + align:start position:0% +my +notes uh there was one other thing uh + + align:start position:0% +notes uh there was one other thing uh + + + align:start position:0% +notes uh there was one other thing uh +which I found a little funny uh + + align:start position:0% +which I found a little funny uh + + + align:start position:0% +which I found a little funny uh +rereading this paper is why eight + + align:start position:0% +rereading this paper is why eight + + + align:start position:0% +rereading this paper is why eight +because uh we know everything has to + + align:start position:0% +because uh we know everything has to + + + align:start position:0% +because uh we know everything has to +scale up by a factor of four but uh and + + align:start position:0% +scale up by a factor of four but uh and + + + align:start position:0% +scale up by a factor of four but uh and +that's that's all we're doing in some + + align:start position:0% +that's that's all we're doing in some + + + align:start position:0% +that's that's all we're doing in some +sense but we do make these uh we scale + + align:start position:0% +sense but we do make these uh we scale + + + align:start position:0% +sense but we do make these uh we scale +all the AIS by a factor of eight + + align:start position:0% +all the AIS by a factor of eight + + + align:start position:0% +all the AIS by a factor of eight +not a big deal but there's a reason for + + align:start position:0% +not a big deal but there's a reason for + + + align:start position:0% +not a big deal but there's a reason for +eight um if we just did + + align:start position:0% +eight um if we just did + + + align:start position:0% +eight um if we just did +four uh and + + align:start position:0% +four uh and + + + align:start position:0% +four uh and +say yeah um so we want to go uh so this + + align:start position:0% +say yeah um so we want to go uh so this + + + align:start position:0% +say yeah um so we want to go uh so this +thing gets mapped onto here and we go + + align:start position:0% +thing gets mapped onto here and we go + + + align:start position:0% +thing gets mapped onto here and we go +out and back and out and back if we just + + align:start position:0% +out and back and out and back if we just + + + align:start position:0% +out and back and out and back if we just +did it four times we would be arriving + + align:start position:0% +did it four times we would be arriving + + + align:start position:0% +did it four times we would be arriving +at basically the same position in the + + align:start position:0% +at basically the same position in the + + + align:start position:0% +at basically the same position in the +4x4x4 block or sorry we would be + + align:start position:0% +4x4x4 block or sorry we would be + + + align:start position:0% +4x4x4 block or sorry we would be +arriving at the same 4x4x4 block that we + + align:start position:0% +arriving at the same 4x4x4 block that we + + + align:start position:0% +arriving at the same 4x4x4 block that we +started from that's not good because we + + align:start position:0% +started from that's not good because we + + + align:start position:0% +started from that's not good because we +can only visit a block once so this is + + align:start position:0% +can only visit a block once so this is + + + align:start position:0% +can only visit a block once so this is +sort of an interface issue between the + + align:start position:0% +sort of an interface issue between the + + + align:start position:0% +sort of an interface issue between the +zigzag which is nice and Universal you + + align:start position:0% +zigzag which is nice and Universal you + + + align:start position:0% +zigzag which is nice and Universal you +can always paste two of these chains + + align:start position:0% +can always paste two of these chains + + + align:start position:0% +can always paste two of these chains +together no problem whereas with this + + align:start position:0% +together no problem whereas with this + + + align:start position:0% +together no problem whereas with this +thing which is not Universal it folds + + align:start position:0% +thing which is not Universal it folds + + + align:start position:0% +thing which is not Universal it folds +into basically the shape um that's it so + + align:start position:0% +into basically the shape um that's it so + + + align:start position:0% +into basically the shape um that's it so +uh we need to make sure that um I mean + + align:start position:0% +uh we need to make sure that um I mean + + + align:start position:0% +uh we need to make sure that um I mean +we can universally do whatever we want + + align:start position:0% +we can universally do whatever we want + + + align:start position:0% +we can universally do whatever we want +in here but we need to make sure that + + align:start position:0% +in here but we need to make sure that + + + align:start position:0% +in here but we need to make sure that +when we connect between this zigzag + + align:start position:0% +when we connect between this zigzag + + + align:start position:0% +when we connect between this zigzag +structure and then we paste in one of + + align:start position:0% +structure and then we paste in one of + + + align:start position:0% +structure and then we paste in one of +these and then we come back that we do + + align:start position:0% +these and then we come back that we do + + + align:start position:0% +these and then we come back that we do +that in a valid way from the perspective + + align:start position:0% +that in a valid way from the perspective + + + align:start position:0% +that in a valid way from the perspective +Ive of this big chunk so the the factor + + align:start position:0% +Ive of this big chunk so the the factor + + + align:start position:0% +Ive of this big chunk so the the factor +of eight makes sure that we if we leave + + align:start position:0% +of eight makes sure that we if we leave + + + align:start position:0% +of eight makes sure that we if we leave +from one 4x4x4 Chunk we come back on a + + align:start position:0% +from one 4x4x4 Chunk we come back on a + + + align:start position:0% +from one 4x4x4 Chunk we come back on a +different one and then it's easy to + + align:start position:0% +different one and then it's easy to + + + align:start position:0% +different one and then it's easy to +paste all the paths + + align:start position:0% +paste all the paths + + + align:start position:0% +paste all the paths +together so that is uh hths yeah I don't + + align:start position:0% +together so that is uh hths yeah I don't + + + align:start position:0% +together so that is uh hths yeah I don't +quite see that this proves that snake + + align:start position:0% +quite see that this proves that snake + + + align:start position:0% +quite see that this proves that snake +cube is empty right ah yeah there's one + + align:start position:0% +cube is empty right ah yeah there's one + + + align:start position:0% +cube is empty right ah yeah there's one +more issue which is uh this was folding + + align:start position:0% +more issue which is uh this was folding + + + align:start position:0% +more issue which is uh this was folding +this shape but we want to fold a cube + + align:start position:0% +this shape but we want to fold a cube + + + align:start position:0% +this shape but we want to fold a cube +yeah this is uh this is the an part of + + align:start position:0% +yeah this is uh this is the an part of + + + align:start position:0% +yeah this is uh this is the an part of +the proof it's very hard to draw um this + + align:start position:0% +the proof it's very hard to draw um this + + + align:start position:0% +the proof it's very hard to draw um this +is my attempt at drawing it and + + align:start position:0% +is my attempt at drawing it and + + + align:start position:0% +is my attempt at drawing it and +um yeah + + align:start position:0% +um yeah + + + align:start position:0% +um yeah +so uh I will sketch the idea uh I'll + + align:start position:0% +so uh I will sketch the idea uh I'll + + + align:start position:0% +so uh I will sketch the idea uh I'll +tell you the the first part is + + align:start position:0% +tell you the the first part is + + + align:start position:0% +tell you the the first part is +conceptually easy again hard to draw um + + align:start position:0% +conceptually easy again hard to draw um + + + align:start position:0% +conceptually easy again hard to draw um +the issue is forcing this chain of + + align:start position:0% +the issue is forcing this chain of + + + align:start position:0% +the issue is forcing this chain of +blocks to do anything and one key idea + + align:start position:0% +blocks to do anything and one key idea + + + align:start position:0% +blocks to do anything and one key idea +is if you want to fold let's say a k by + + align:start position:0% +is if you want to fold let's say a k by + + + align:start position:0% +is if you want to fold let's say a k by +K by K box if you have a straight path + + align:start position:0% +K by K box if you have a straight path + + + align:start position:0% +K by K box if you have a straight path +of length + + align:start position:0% +of length + + + align:start position:0% +of length +K uh there AR very many places you can + + align:start position:0% +K uh there AR very many places you can + + + align:start position:0% +K uh there AR very many places you can +put that I mean there I guess there are + + align:start position:0% +put that I mean there I guess there are + + + align:start position:0% +put that I mean there I guess there are +still Cas orders K squared of them um + + align:start position:0% +still Cas orders K squared of them um + + + align:start position:0% +still Cas orders K squared of them um +but you you have to start and end at the + + align:start position:0% +but you you have to start and end at the + + + align:start position:0% +but you you have to start and end at the +beginning and end of the of the overall + + align:start position:0% +beginning and end of the of the overall + + + align:start position:0% +beginning and end of the of the overall +Cube if you have a full length of + + align:start position:0% +Cube if you have a full length of + + + align:start position:0% +Cube if you have a full length of +straight so the first step we do is take + + align:start position:0% +straight so the first step we do is take + + + align:start position:0% +straight so the first step we do is take +your oh sorry the this is the first step + + align:start position:0% +your oh sorry the this is the first step + + + align:start position:0% +your oh sorry the this is the first step +it's upside down because we're doing + + align:start position:0% +it's upside down because we're doing + + + align:start position:0% +it's upside down because we're doing +things in reverse order so first thing + + align:start position:0% +things in reverse order so first thing + + + align:start position:0% +things in reverse order so first thing +we do is we take a Target Cube and we're + + align:start position:0% +we do is we take a Target Cube and we're + + + align:start position:0% +we do is we take a Target Cube and we're +basically going to have a lot of really + + align:start position:0% +basically going to have a lot of really + + + align:start position:0% +basically going to have a lot of really +long guys will force you to in in a row + + align:start position:0% +long guys will force you to in in a row + + + align:start position:0% +long guys will force you to in in a row +and you see that in these kinds of + + align:start position:0% +and you see that in these kinds of + + + align:start position:0% +and you see that in these kinds of +puzzles you tend to have uh Straits of + + align:start position:0% +puzzles you tend to have uh Straits of + + + align:start position:0% +puzzles you tend to have uh Straits of +length three like this this um these are + + align:start position:0% +length three like this this um these are + + + align:start position:0% +length three like this this um these are +three threes in a row and we're making a + + align:start position:0% +three threes in a row and we're making a + + + align:start position:0% +three threes in a row and we're making a +3x3x3 Cub so that sort of has that has + + align:start position:0% +3x3x3 Cub so that sort of has that has + + + align:start position:0% +3x3x3 Cub so that sort of has that has +to live in well it can do weird things + + align:start position:0% +to live in well it can do weird things + + + align:start position:0% +to live in well it can do weird things +but it's relatively restricted maybe you + + align:start position:0% +but it's relatively restricted maybe you + + + align:start position:0% +but it's relatively restricted maybe you +can do something like this but then + + align:start position:0% +can do something like this but then + + + align:start position:0% +can do something like this but then +these must be the edges of the cube in + + align:start position:0% +these must be the edges of the cube in + + + align:start position:0% +these must be the edges of the cube in +that case so we have a bunch of those + + align:start position:0% +that case so we have a bunch of those + + + align:start position:0% +that case so we have a bunch of those +and lots of care and we end up reducing + + align:start position:0% +and lots of care and we end up reducing + + + align:start position:0% +and lots of care and we end up reducing +the cube to a box meaning we cover all + + align:start position:0% +the cube to a box meaning we cover all + + + align:start position:0% +the cube to a box meaning we cover all +of the cube we're forced to cover all of + + align:start position:0% +of the cube we're forced to cover all of + + + align:start position:0% +of the cube we're forced to cover all of +the cube and leave exactly a box behind + + align:start position:0% +the cube and leave exactly a box behind + + + align:start position:0% +the cube and leave exactly a box behind +sort of like what we did when we were + + align:start position:0% +sort of like what we did when we were + + + align:start position:0% +sort of like what we did when we were +doing squares into square we'd put a + + align:start position:0% +doing squares into square we'd put a + + + align:start position:0% +doing squares into square we'd put a +bunch of big boxes that were relatively + + align:start position:0% +bunch of big boxes that were relatively + + + align:start position:0% +bunch of big boxes that were relatively +constrained and it just left a empty + + align:start position:0% +constrained and it just left a empty + + + align:start position:0% +constrained and it just left a empty +space which is a box here it's actually + + align:start position:0% +space which is a box here it's actually + + + align:start position:0% +space which is a box here it's actually +forced + + align:start position:0% +forced + + + align:start position:0% +forced +exactly then once we have a box so the + + align:start position:0% +exactly then once we have a box so the + + + align:start position:0% +exactly then once we have a box so the +Box will be this wide and it will go + + align:start position:0% +Box will be this wide and it will go + + + align:start position:0% +Box will be this wide and it will go +over this way um and but it won't have + + align:start position:0% +over this way um and but it won't have + + + align:start position:0% +over this way um and but it won't have +this sort of fine feature stuff this + + align:start position:0% +this sort of fine feature stuff this + + + align:start position:0% +this sort of fine feature stuff this +will just all be filled in as a box then + + align:start position:0% +will just all be filled in as a box then + + + align:start position:0% +will just all be filled in as a box then +uh this step that's drawn is to carve + + align:start position:0% +uh this step that's drawn is to carve + + + align:start position:0% +uh this step that's drawn is to carve +out this uh Hub and spoke shape uh and + + align:start position:0% +out this uh Hub and spoke shape uh and + + + align:start position:0% +out this uh Hub and spoke shape uh and +that's based on a structure like this + + align:start position:0% +that's based on a structure like this + + + align:start position:0% +that's based on a structure like this +where you have a a huge thing and then a + + align:start position:0% +where you have a a huge thing and then a + + + align:start position:0% +where you have a a huge thing and then a +relatively short thing of length about + + align:start position:0% +relatively short thing of length about + + + align:start position:0% +relatively short thing of length about +8T and then we go down and then + + align:start position:0% +8T and then we go down and then + + + align:start position:0% +8T and then we go down and then +immediately back up and then over and + + align:start position:0% +immediately back up and then over and + + + align:start position:0% +immediately back up and then over and +down and up and and so on + + align:start position:0% +down and up and and so on + + + align:start position:0% +down and up and and so on +and you that roughly carves out this + + align:start position:0% +and you that roughly carves out this + + + align:start position:0% +and you that roughly carves out this +structure now you have to be careful + + align:start position:0% +structure now you have to be careful + + + align:start position:0% +structure now you have to be careful +that this is actually unique + + align:start position:0% +that this is actually unique + + + align:start position:0% +that this is actually unique +uh but we have some this is why we only + + align:start position:0% +uh but we have some this is why we only + + + align:start position:0% +uh but we have some this is why we only +want the height of this box to be eight + + align:start position:0% +want the height of this box to be eight + + + align:start position:0% +want the height of this box to be eight +because then you can't go out of plane + + align:start position:0% +because then you can't go out of plane + + + align:start position:0% +because then you can't go out of plane +very much and this while this is short + + align:start position:0% +very much and this while this is short + + + align:start position:0% +very much and this while this is short +it's longer than eight if T is bigger + + align:start position:0% +it's longer than eight if T is bigger + + + align:start position:0% +it's longer than eight if T is bigger +than one so um you can't have this spoke + + align:start position:0% +than one so um you can't have this spoke + + + align:start position:0% +than one so um you can't have this spoke +go up so it does have to live in a + + align:start position:0% +go up so it does have to live in a + + + align:start position:0% +go up so it does have to live in a +plane uh sounds right and this is much + + align:start position:0% +plane uh sounds right and this is much + + + align:start position:0% +plane uh sounds right and this is much +smaller than huge so you can't fold it + + align:start position:0% +smaller than huge so you can't fold it + + + align:start position:0% +smaller than huge so you can't fold it +some other way uh so that's pretty much + + align:start position:0% +some other way uh so that's pretty much + + + align:start position:0% +some other way uh so that's pretty much +forced and then we have to get rid of + + align:start position:0% +forced and then we have to get rid of + + + align:start position:0% +forced and then we have to get rid of +the other uh seven planes which we do + + align:start position:0% +the other uh seven planes which we do + + + align:start position:0% +the other uh seven planes which we do +with really long guys so uh + + align:start position:0% +with really long guys so uh + + + align:start position:0% +with really long guys so uh +unfortunately we don't have all of that + + align:start position:0% +unfortunately we don't have all of that + + + align:start position:0% +unfortunately we don't have all of that +drawn so it's especially hard to see but + + align:start position:0% +drawn so it's especially hard to see but + + + align:start position:0% +drawn so it's especially hard to see but +this is a rough idea of how you start + + align:start position:0% +this is a rough idea of how you start + + + align:start position:0% +this is a rough idea of how you start +with a box and you do uh these sort of + + align:start position:0% +with a box and you do uh these sort of + + + align:start position:0% +with a box and you do uh these sort of +infrastructure gadgets to just carve out + + align:start position:0% +infrastructure gadgets to just carve out + + + align:start position:0% +infrastructure gadgets to just carve out +the shape you want and then it's then + + align:start position:0% +the shape you want and then it's then + + + align:start position:0% +the shape you want and then it's then +you go into the interesting part of the + + align:start position:0% +you go into the interesting part of the + + + align:start position:0% +you go into the interesting part of the +chain this is all at the beginning of + + align:start position:0% +chain this is all at the beginning of + + + align:start position:0% +chain this is all at the beginning of +the chain and it's you show it's forced + + align:start position:0% +the chain and it's you show it's forced + + + align:start position:0% +the chain and it's you show it's forced +to do all this and then we start say + + align:start position:0% +to do all this and then we start say + + + align:start position:0% +to do all this and then we start say +here with some zigzag and then an AI + + align:start position:0% +here with some zigzag and then an AI + + + align:start position:0% +here with some zigzag and then an AI +Gadget and so on yes + + align:start position:0% + + + + align:start position:0% + +easy right so um you do see here I would + + align:start position:0% +easy right so um you do see here I would + + + align:start position:0% +easy right so um you do see here I would +say a very uh algorithmic approach I + + align:start position:0% +say a very uh algorithmic approach I + + + align:start position:0% +say a very uh algorithmic approach I +mean this idea of showing that uh + + align:start position:0% +mean this idea of showing that uh + + + align:start position:0% +mean this idea of showing that uh +zigzags are Universal they can make any + + align:start position:0% +zigzags are Universal they can make any + + + align:start position:0% +zigzags are Universal they can make any +shape this is something we do in + + align:start position:0% +shape this is something we do in + + + align:start position:0% +shape this is something we do in +computational Geometry all the time we + + align:start position:0% +computational Geometry all the time we + + + align:start position:0% +computational Geometry all the time we +Pro that these folding structures fold + + align:start position:0% +Pro that these folding structures fold + + + align:start position:0% +Pro that these folding structures fold +into whatever we want so we uh and we + + align:start position:0% +into whatever we want so we uh and we + + + align:start position:0% +into whatever we want so we uh and we +hadn't proved this one before but we + + align:start position:0% +hadn't proved this one before but we + + + align:start position:0% +hadn't proved this one before but we +were armed with a lot of algorithmic + + align:start position:0% +were armed with a lot of algorithmic + + + align:start position:0% +were armed with a lot of algorithmic +tools to do this and that led us do this + + align:start position:0% +tools to do this and that led us do this + + + align:start position:0% +tools to do this and that led us do this +reduction so lower bounds in our case is + + align:start position:0% +reduction so lower bounds in our case is + + + align:start position:0% +reduction so lower bounds in our case is +really all about designing the right + + align:start position:0% +really all about designing the right + + + align:start position:0% +really all about designing the right +algorithms uh to give you powerful + + align:start position:0% +algorithms uh to give you powerful + + + align:start position:0% +algorithms uh to give you powerful +gadgets like this that's why this is the + + align:start position:0% +gadgets like this that's why this is the + + + align:start position:0% +gadgets like this that's why this is the +class called algorithmic Lower + + align:start position:0% +class called algorithmic Lower + + + align:start position:0% +class called algorithmic Lower +bounds um other questions about snake + + align:start position:0% +bounds um other questions about snake + + + align:start position:0% +bounds um other questions about snake +cubes + + align:start position:0% + + + + align:start position:0% + +Adam uh I think we want it to be a + + align:start position:0% +Adam uh I think we want it to be a + + + align:start position:0% +Adam uh I think we want it to be a +multiple of + + align:start position:0% +multiple of + + + align:start position:0% +multiple of +four uh so that it's compatible with the + + align:start position:0% +four uh so that it's compatible with the + + + align:start position:0% +four uh so that it's compatible with the +grid six yeah that seems + + align:start position:0% + + + + align:start position:0% + +cleaner that way we can predict if we + + align:start position:0% +cleaner that way we can predict if we + + + align:start position:0% +cleaner that way we can predict if we +leave on this 4x4x4 thing we know which + + align:start position:0% +leave on this 4x4x4 thing we know which + + + align:start position:0% +leave on this 4x4x4 thing we know which +one will come back on whereas if it's + + align:start position:0% +one will come back on whereas if it's + + + align:start position:0% +one will come back on whereas if it's +could be in a half grid position that + + align:start position:0% +could be in a half grid position that + + + align:start position:0% +could be in a half grid position that +would be + + align:start position:0% +would be + + + align:start position:0% +would be +messy other + + align:start position:0% +messy other + + + align:start position:0% +messy other +questions I you might be able to make + + align:start position:0% +questions I you might be able to make + + + align:start position:0% +questions I you might be able to make +that to work but the advantage of + + align:start position:0% +that to work but the advantage of + + + align:start position:0% +that to work but the advantage of +hardness proofs because it's not a real + + align:start position:0% +hardness proofs because it's not a real + + + align:start position:0% +hardness proofs because it's not a real +algorithm I mean it's not an algorithm + + align:start position:0% +algorithm I mean it's not an algorithm + + + align:start position:0% +algorithm I mean it's not an algorithm +you want to run the point is to show + + align:start position:0% +you want to run the point is to show + + + align:start position:0% +you want to run the point is to show +this problem is hard you can be + + align:start position:0% +this problem is hard you can be + + + align:start position:0% +this problem is hard you can be +inefficient in lots of places as long as + + align:start position:0% +inefficient in lots of places as long as + + + align:start position:0% +inefficient in lots of places as long as +it's still polinomial it doesn't really + + align:start position:0% +it's still polinomial it doesn't really + + + align:start position:0% +it's still polinomial it doesn't really +matter except for drawing the pictures + + align:start position:0% +matter except for drawing the pictures + + + align:start position:0% +matter except for drawing the pictures +that's one place where it + + align:start position:0% +that's one place where it + + + align:start position:0% +that's one place where it +matters all right that's snake cubes uh + + align:start position:0% +matters all right that's snake cubes uh + + + align:start position:0% +matters all right that's snake cubes uh +going to go on to another packing + + align:start position:0% +going to go on to another packing + + + align:start position:0% +going to go on to another packing +problem so we've seen rectangles into + + align:start position:0% +problem so we've seen rectangles into + + + align:start position:0% +problem so we've seen rectangles into +squares squares into squares how about + + align:start position:0% +squares squares into squares how about + + + align:start position:0% +squares squares into squares how about +circles into + + align:start position:0% +circles into + + + align:start position:0% +circles into +squares um so this is a real life puzzle + + align:start position:0% +squares um so this is a real life puzzle + + + align:start position:0% +squares um so this is a real life puzzle +uh where you have these uh I think + + align:start position:0% +uh where you have these uh I think + + + align:start position:0% +uh where you have these uh I think +they're waterjet cut or laser cut uh + + align:start position:0% +they're waterjet cut or laser cut uh + + + align:start position:0% +they're waterjet cut or laser cut uh +metal discs and you have to fit them + + align:start position:0% +metal discs and you have to fit them + + + align:start position:0% +metal discs and you have to fit them +into this box uh so these are real life + + align:start position:0% +into this box uh so these are real life + + + align:start position:0% +into this box uh so these are real life +puzzles that's one motivation uh there's + + align:start position:0% +puzzles that's one motivation uh there's + + + align:start position:0% +puzzles that's one motivation uh there's +a stronger motivation for studying this + + align:start position:0% +a stronger motivation for studying this + + + align:start position:0% +a stronger motivation for studying this +problem because it's related to + + align:start position:0% +problem because it's related to + + + align:start position:0% +problem because it's related to +computational origami there's this + + align:start position:0% +computational origami there's this + + + align:start position:0% +computational origami there's this +method called the tree method of or + + align:start position:0% +method called the tree method of or + + + align:start position:0% +method called the tree method of or +origami design uh if you're interested + + align:start position:0% +origami design uh if you're interested + + + align:start position:0% +origami design uh if you're interested +in it you can take 6849 or read Robert + + align:start position:0% +in it you can take 6849 or read Robert + + + align:start position:0% +in it you can take 6849 or read Robert +Lang's book uh origami design secrets + + align:start position:0% +Lang's book uh origami design secrets + + + align:start position:0% +Lang's book uh origami design secrets +and basically it lets you fold things + + align:start position:0% +and basically it lets you fold things + + + align:start position:0% +and basically it lets you fold things +like this um that's at a high level you + + align:start position:0% +like this um that's at a high level you + + + align:start position:0% +like this um that's at a high level you +and a key key component of it is to pack + + align:start position:0% +and a key key component of it is to pack + + + align:start position:0% +and a key key component of it is to pack +discs into a square the square is your + + align:start position:0% +discs into a square the square is your + + + align:start position:0% +discs into a square the square is your +piece of paper the discs correspond to + + align:start position:0% +piece of paper the discs correspond to + + + align:start position:0% +piece of paper the discs correspond to +sort of the limbs of your creature and + + align:start position:0% +sort of the limbs of your creature and + + + align:start position:0% +sort of the limbs of your creature and +uh you can't use the same piece of paper + + align:start position:0% +uh you can't use the same piece of paper + + + align:start position:0% +uh you can't use the same piece of paper +to represent this Limb and this limb so + + align:start position:0% +to represent this Limb and this limb so + + + align:start position:0% +to represent this Limb and this limb so +the discs have to be disjoint so it's + + align:start position:0% +the discs have to be disjoint so it's + + + align:start position:0% +the discs have to be disjoint so it's +all about pack those discs into given + + align:start position:0% +all about pack those discs into given + + + align:start position:0% +all about pack those discs into given +square and uh yeah so that's at a high + + align:start position:0% +square and uh yeah so that's at a high + + + align:start position:0% +square and uh yeah so that's at a high +level why we care about dis packing and + + align:start position:0% +level why we care about dis packing and + + + align:start position:0% +level why we care about dis packing and +people have thought about dis packing a + + align:start position:0% +people have thought about dis packing a + + + align:start position:0% +people have thought about dis packing a +lot um but surprisingly it hadn't been + + align:start position:0% +lot um but surprisingly it hadn't been + + + align:start position:0% +lot um but surprisingly it hadn't been +proved hard until uh four years ago so + + align:start position:0% +proved hard until uh four years ago so + + + align:start position:0% +proved hard until uh four years ago so +um this proof is also complicated so uh + + align:start position:0% +um this proof is also complicated so uh + + + align:start position:0% +um this proof is also complicated so uh +and it involves a lot of geometry and + + align:start position:0% +and it involves a lot of geometry and + + + align:start position:0% +and it involves a lot of geometry and +trigonometry and some calculus and fun + + align:start position:0% +trigonometry and some calculus and fun + + + align:start position:0% +trigonometry and some calculus and fun +stuff so I'm going to give you a sketch + + align:start position:0% +stuff so I'm going to give you a sketch + + + align:start position:0% +stuff so I'm going to give you a sketch +of it and you should be believable that + + align:start position:0% +of it and you should be believable that + + + align:start position:0% +of it and you should be believable that +this works but the details again are + + align:start position:0% +this works but the details again are + + + align:start position:0% +this works but the details again are +messy um for starters let's say that + + align:start position:0% +messy um for starters let's say that + + + align:start position:0% +messy um for starters let's say that +we're packing discs into a equilateral + + align:start position:0% +we're packing discs into a equilateral + + + align:start position:0% +we're packing discs into a equilateral +triangle this is much easier to work + + align:start position:0% +triangle this is much easier to work + + + align:start position:0% +triangle this is much easier to work +with I'll go to a square in a second so + + align:start position:0% +with I'll go to a square in a second so + + + align:start position:0% +with I'll go to a square in a second so +uh if I have this equilateral triangle + + align:start position:0% +uh if I have this equilateral triangle + + + align:start position:0% +uh if I have this equilateral triangle +what I'm going to do is first I'm going + + align:start position:0% +what I'm going to do is first I'm going + + + align:start position:0% +what I'm going to do is first I'm going +to give you a bunch of discs that are + + align:start position:0% +to give you a bunch of discs that are + + + align:start position:0% +to give you a bunch of discs that are +forced to pack in this nice uh + + align:start position:0% +forced to pack in this nice uh + + + align:start position:0% +forced to pack in this nice uh +triangular grid Arrangement uh leaving + + align:start position:0% +triangular grid Arrangement uh leaving + + + align:start position:0% +triangular grid Arrangement uh leaving +these uh dark + + align:start position:0% +these uh dark + + + align:start position:0% +these uh dark +holes and I'm going to give you more + + align:start position:0% +holes and I'm going to give you more + + + align:start position:0% +holes and I'm going to give you more +discs and so the the more discs have to + + align:start position:0% +discs and so the the more discs have to + + + align:start position:0% +discs and so the the more discs have to +go into those holes and these are + + align:start position:0% +go into those holes and these are + + + align:start position:0% +go into those holes and these are +actually kissing discs they're touching + + align:start position:0% +actually kissing discs they're touching + + + align:start position:0% +actually kissing discs they're touching +uh so you can only put uh every disc you + + align:start position:0% +uh so you can only put uh every disc you + + + align:start position:0% +uh so you can only put uh every disc you +put from now on will be in one of these + + align:start position:0% +put from now on will be in one of these + + + align:start position:0% +put from now on will be in one of these +holes and I'm just going to do this in + + align:start position:0% +holes and I'm just going to do this in + + + align:start position:0% +holes and I'm just going to do this in +big enough so that I have at least n + + align:start position:0% +big enough so that I have at least n + + + align:start position:0% +big enough so that I have at least n +over three holes each hole is going to + + align:start position:0% +over three holes each hole is going to + + + align:start position:0% +over three holes each hole is going to +represent a bin that I'm trying to put a + + align:start position:0% +represent a bin that I'm trying to put a + + + align:start position:0% +represent a bin that I'm trying to put a +triple of numbers into and then uh here + + align:start position:0% +triple of numbers into and then uh here + + + align:start position:0% +triple of numbers into and then uh here +is the construction for uh I guess this + + align:start position:0% +is the construction for uh I guess this + + + align:start position:0% +is the construction for uh I guess this +would be a three partition Gadget uh we + + align:start position:0% +would be a three partition Gadget uh we + + + align:start position:0% +would be a three partition Gadget uh we +want to get that slight type of the AI + + align:start position:0% +want to get that slight type of the AI + + + align:start position:0% +want to get that slight type of the AI +plus AJ plus a + + align:start position:0% +plus AJ plus a + + + align:start position:0% +plus AJ plus a +is less than equal to T um and so these + + align:start position:0% +is less than equal to T um and so these + + + align:start position:0% +is less than equal to T um and so these +are the three discs representing AI AJ + + align:start position:0% +are the three discs representing AI AJ + + + align:start position:0% +are the three discs representing AI AJ +and + + align:start position:0% +and + + + align:start position:0% +and +a and there's an extra disc in the + + align:start position:0% +a and there's an extra disc in the + + + align:start position:0% +a and there's an extra disc in the +center and what's drawn here is + + align:start position:0% +center and what's drawn here is + + + align:start position:0% +center and what's drawn here is +everything is maybe tight and as + + align:start position:0% +everything is maybe tight and as + + + align:start position:0% +everything is maybe tight and as +touching but we're going to shrink these + + align:start position:0% +touching but we're going to shrink these + + + align:start position:0% +touching but we're going to shrink these +discs a little bit uh or rather I'm + + align:start position:0% +discs a little bit uh or rather I'm + + + align:start position:0% +discs a little bit uh or rather I'm +going to shrink uh yeah I guess I'll + + align:start position:0% +going to shrink uh yeah I guess I'll + + + align:start position:0% +going to shrink uh yeah I guess I'll +shrink well get this right I'm going to + + align:start position:0% +shrink well get this right I'm going to + + + align:start position:0% +shrink well get this right I'm going to +shrink this disc a little bit and I'm + + align:start position:0% +shrink this disc a little bit and I'm + + + align:start position:0% +shrink this disc a little bit and I'm +going to make these ones a little bit + + align:start position:0% +going to make these ones a little bit + + + align:start position:0% +going to make these ones a little bit +bigger + + align:start position:0% +bigger + + + align:start position:0% +bigger +according to the AI values um so this + + align:start position:0% +according to the AI values um so this + + + align:start position:0% +according to the AI values um so this +one will be proportional to AK larger + + align:start position:0% +one will be proportional to AK larger + + + align:start position:0% +one will be proportional to AK larger +than the disc that would perfectly fit + + align:start position:0% +than the disc that would perfectly fit + + + align:start position:0% +than the disc that would perfectly fit +here if this one was maximally sized and + + align:start position:0% +here if this one was maximally sized and + + + align:start position:0% +here if this one was maximally sized and +so that's going to force this guy to + + align:start position:0% +so that's going to force this guy to + + + align:start position:0% +so that's going to force this guy to +move away well he's a little bit shrunk + + align:start position:0% +move away well he's a little bit shrunk + + + align:start position:0% +move away well he's a little bit shrunk +so maybe he doesn't have to move away um + + align:start position:0% +so maybe he doesn't have to move away um + + + align:start position:0% +so maybe he doesn't have to move away um +but this Center disc when it's shrunk + + align:start position:0% +but this Center disc when it's shrunk + + + align:start position:0% +but this Center disc when it's shrunk +down it has a little bit of flexibility + + align:start position:0% +down it has a little bit of flexibility + + + align:start position:0% +down it has a little bit of flexibility +it could move more this way if this disc + + align:start position:0% +it could move more this way if this disc + + + align:start position:0% +it could move more this way if this disc +is smaller it will move more this way it + + align:start position:0% +is smaller it will move more this way it + + + align:start position:0% +is smaller it will move more this way it +can move more this way more this way and + + align:start position:0% +can move more this way more this way and + + + align:start position:0% +can move more this way more this way and +in general you show that um these so + + align:start position:0% +in general you show that um these so + + + align:start position:0% +in general you show that um these so +these guys are sort of placing demands + + align:start position:0% +these guys are sort of placing demands + + + align:start position:0% +these guys are sort of placing demands +by being a little bit bigger they need + + align:start position:0% +by being a little bit bigger they need + + + align:start position:0% +by being a little bit bigger they need +to push out uh and this one is a little + + align:start position:0% +to push out uh and this one is a little + + + align:start position:0% +to push out uh and this one is a little +bit smaller and its size is just a + + align:start position:0% +bit smaller and its size is just a + + + align:start position:0% +bit smaller and its size is just a +function of + + align:start position:0% +function of + + + align:start position:0% +function of +T and so it's going to move around and + + align:start position:0% +T and so it's going to move around and + + + align:start position:0% +T and so it's going to move around and +the claim is uh it has a valid position + + align:start position:0% +the claim is uh it has a valid position + + + align:start position:0% +the claim is uh it has a valid position +if and only if a i plus AJ plus a k is + + align:start position:0% +if and only if a i plus AJ plus a k is + + + align:start position:0% +if and only if a i plus AJ plus a k is +less than equal to T I have written down + + align:start position:0% +less than equal to T I have written down + + + align:start position:0% +less than equal to T I have written down +a little bit of the + + align:start position:0% +a little bit of the + + + align:start position:0% +a little bit of the +details um + + align:start position:0% + + + + align:start position:0% + +so we're going to choose some big number + + align:start position:0% +so we're going to choose some big number + + + align:start position:0% +so we're going to choose some big number +capital N maybe it's like n to the 100 + + align:start position:0% +capital N maybe it's like n to the 100 + + + align:start position:0% +capital N maybe it's like n to the 100 +little n to the 100 something like that + + align:start position:0% +little n to the 100 something like that + + + align:start position:0% +little n to the 100 something like that +and we'll shrink the big disc by that + + align:start position:0% +and we'll shrink the big disc by that + + + align:start position:0% +and we'll shrink the big disc by that +amount uh I'm going to scale everything + + align:start position:0% +amount uh I'm going to scale everything + + + align:start position:0% +amount uh I'm going to scale everything +so that t equals 1 um that will simplify + + align:start position:0% +so that t equals 1 um that will simplify + + + align:start position:0% +so that t equals 1 um that will simplify +things a little bit so just shrink + + align:start position:0% +things a little bit so just shrink + + + align:start position:0% +things a little bit so just shrink +everything uh all the values down divide + + align:start position:0% +everything uh all the values down divide + + + align:start position:0% +everything uh all the values down divide +everything by T AI is in the T + + align:start position:0% +everything by T AI is in the T + + + align:start position:0% +everything by T AI is in the T +um and + + align:start position:0% +um and + + + align:start position:0% +um and +then I think we're going + + align:start position:0% +then I think we're going + + + align:start position:0% +then I think we're going +to uh + + align:start position:0% +to uh + + + align:start position:0% +to uh +shrink the AI + + align:start position:0% +shrink the AI + + + align:start position:0% +shrink the AI +disc + + align:start position:0% +disc + + + align:start position:0% +disc +by Min -1 Over N sared plus AI Over N + + align:start position:0% +by Min -1 Over N sared plus AI Over N + + + align:start position:0% +by Min -1 Over N sared plus AI Over N +this is a funny notion of shrink uh I'm + + align:start position:0% +this is a funny notion of shrink uh I'm + + + align:start position:0% +this is a funny notion of shrink uh I'm +going to first make it smaller by 1 over + + align:start position:0% +going to first make it smaller by 1 over + + + align:start position:0% +going to first make it smaller by 1 over +n^2 and then I'm going to grow it by AI + + align:start position:0% +n^2 and then I'm going to grow it by AI + + + align:start position:0% +n^2 and then I'm going to grow it by AI +Over N um this term I believe is to + + align:start position:0% +Over N um this term I believe is to + + + align:start position:0% +Over N um this term I believe is to +uh get rid of smaller things in the + + align:start position:0% +uh get rid of smaller things in the + + + align:start position:0% +uh get rid of smaller things in the +tailor expansion so discs are annoying + + align:start position:0% +tailor expansion so discs are annoying + + + align:start position:0% +tailor expansion so discs are annoying +because they're circular uh because + + align:start position:0% +because they're circular uh because + + + align:start position:0% +because they're circular uh because +they're quadratic curves and so you get + + align:start position:0% +they're quadratic curves and so you get + + + align:start position:0% +they're quadratic curves and so you get +uh you know it's it's an awkward shape + + align:start position:0% +uh you know it's it's an awkward shape + + + align:start position:0% +uh you know it's it's an awkward shape +to deal with um and you're worried about + + align:start position:0% +to deal with um and you're worried about + + + align:start position:0% +to deal with um and you're worried about +how how I move this Center relative to + + align:start position:0% +how how I move this Center relative to + + + align:start position:0% +how how I move this Center relative to +how I move the other centers and whether + + align:start position:0% +how I move the other centers and whether + + + align:start position:0% +how I move the other centers and whether +they're hitting each other and whether + + align:start position:0% +they're hitting each other and whether + + + align:start position:0% +they're hitting each other and whether +they're hitting each other is a + + align:start position:0% +they're hitting each other is a + + + align:start position:0% +they're hitting each other is a +quadratic constraint you have to measure + + align:start position:0% +quadratic constraint you have to measure + + + align:start position:0% +quadratic constraint you have to measure +the distance between these two points it + + align:start position:0% +the distance between these two points it + + + align:start position:0% +the distance between these two points it +should be greater than or equal to the + + align:start position:0% +should be greater than or equal to the + + + align:start position:0% +should be greater than or equal to the +sum of the + + align:start position:0% +sum of the + + + align:start position:0% +sum of the +radi uh so that's tough to work with so + + align:start position:0% +radi uh so that's tough to work with so + + + align:start position:0% +radi uh so that's tough to work with so +to simplify things we take first + + align:start position:0% +to simplify things we take first + + + align:start position:0% +to simplify things we take first +derivatives and say well to the first + + align:start position:0% +derivatives and say well to the first + + + align:start position:0% +derivatives and say well to the first +order what's happening when I move these + + align:start position:0% +order what's happening when I move these + + + align:start position:0% +order what's happening when I move these +discs around and uh when you take first + + align:start position:0% +discs around and uh when you take first + + + align:start position:0% +discs around and uh when you take first +derivatives you get an approximation to + + align:start position:0% +derivatives you get an approximation to + + + align:start position:0% +derivatives you get an approximation to +the truth and the second derivative + + align:start position:0% +the truth and the second derivative + + + align:start position:0% +the truth and the second derivative +tells you a little bit more of the truth + + align:start position:0% +tells you a little bit more of the truth + + + align:start position:0% +tells you a little bit more of the truth +and uh if you've ever done Taylor uh + + align:start position:0% +and uh if you've ever done Taylor uh + + + align:start position:0% +and uh if you've ever done Taylor uh +series you know you get something like 1 + + align:start position:0% +series you know you get something like 1 + + + align:start position:0% +series you know you get something like 1 +over n something * 1 n plus something + + align:start position:0% +over n something * 1 n plus something + + + align:start position:0% +over n something * 1 n plus something +Time 1 n^ 2 and so on um and so if if we + + align:start position:0% +Time 1 n^ 2 and so on um and so if if we + + + align:start position:0% +Time 1 n^ 2 and so on um and so if if we +just subtract off this term make these + + align:start position:0% +just subtract off this term make these + + + align:start position:0% +just subtract off this term make these +discs a little bit smaller than they + + align:start position:0% +discs a little bit smaller than they + + + align:start position:0% +discs a little bit smaller than they +need to be uh that lets you deal with + + align:start position:0% +need to be uh that lets you deal with + + + align:start position:0% +need to be uh that lets you deal with +all those terms all at once so it lets + + align:start position:0% +all those terms all at once so it lets + + + align:start position:0% +all those terms all at once so it lets +us focus on the lead term uh and to the + + align:start position:0% +us focus on the lead term uh and to the + + + align:start position:0% +us focus on the lead term uh and to the +first order the claim is what happens is + + align:start position:0% +first order the claim is what happens is + + + align:start position:0% +first order the claim is what happens is +well we made this disc smaller by one + + align:start position:0% +well we made this disc smaller by one + + + align:start position:0% +well we made this disc smaller by one +remember one is T we made the other guys + + align:start position:0% +remember one is T we made the other guys + + + align:start position:0% +remember one is T we made the other guys +larger by AI so um that's going to work + + align:start position:0% +larger by AI so um that's going to work + + + align:start position:0% +larger by AI so um that's going to work +out exactly when the sum of the three I + + align:start position:0% +out exactly when the sum of the three I + + + align:start position:0% +out exactly when the sum of the three I +is less than equal to one then this will + + align:start position:0% +is less than equal to one then this will + + + align:start position:0% +is less than equal to one then this will +all have room and that's true to the + + align:start position:0% +all have room and that's true to the + + + align:start position:0% +all have room and that's true to the +first order and you have to do this ugly + + align:start position:0% +first order and you have to do this ugly + + + align:start position:0% +first order and you have to do this ugly +business to make it true exactly so I + + align:start position:0% +business to make it true exactly so I + + + align:start position:0% +business to make it true exactly so I +think without going into vector algebra + + align:start position:0% +think without going into vector algebra + + + align:start position:0% +think without going into vector algebra +this is the intuition of what's going + + align:start position:0% +this is the intuition of what's going + + + align:start position:0% +this is the intuition of what's going +on + + align:start position:0% +on + + + align:start position:0% +on +and that's that + + align:start position:0% +and that's that + + + align:start position:0% +and that's that +proof any questions the point here is to + + align:start position:0% +proof any questions the point here is to + + + align:start position:0% +proof any questions the point here is to +expose you to lots of different ways to + + align:start position:0% +expose you to lots of different ways to + + + align:start position:0% +expose you to lots of different ways to +represent numbers and uh three partition + + align:start position:0% +represent numbers and uh three partition + + + align:start position:0% +represent numbers and uh three partition +and uh a lot of the times it comes up in + + align:start position:0% +and uh a lot of the times it comes up in + + + align:start position:0% +and uh a lot of the times it comes up in +geometric settings but so far we've seen + + align:start position:0% +geometric settings but so far we've seen + + + align:start position:0% +geometric settings but so far we've seen +rather different ways to represent it + + align:start position:0% +rather different ways to represent it + + + align:start position:0% +rather different ways to represent it +we'll see graph theory in a moment um + + align:start position:0% +we'll see graph theory in a moment um + + + align:start position:0% +we'll see graph theory in a moment um +probably next up is games and puzzles so + + align:start position:0% +probably next up is games and puzzles so + + + align:start position:0% +probably next up is games and puzzles so +let's play some + + align:start position:0% +let's play some + + + align:start position:0% +let's play some +games uh oh I have a right there was one + + align:start position:0% +games uh oh I have a right there was one + + + align:start position:0% +games uh oh I have a right there was one +more part of this proof I forgot uh what + + align:start position:0% +more part of this proof I forgot uh what + + + align:start position:0% +more part of this proof I forgot uh what +if you're packing into a square this is + + align:start position:0% +if you're packing into a square this is + + + align:start position:0% +if you're packing into a square this is +particularly important for origami this + + align:start position:0% +particularly important for origami this + + + align:start position:0% +particularly important for origami this +paper appeared in an origami conference + + align:start position:0% +paper appeared in an origami conference + + + align:start position:0% +paper appeared in an origami conference +so uh we needed to solve the case of + + align:start position:0% +so uh we needed to solve the case of + + + align:start position:0% +so uh we needed to solve the case of +square packing this is more Awkward um + + align:start position:0% +square packing this is more Awkward um + + + align:start position:0% +square packing this is more Awkward um +the idea uh because you can't make a + + align:start position:0% +the idea uh because you can't make a + + + align:start position:0% +the idea uh because you can't make a +nice regular grid on a you know Square + + align:start position:0% +nice regular grid on a you know Square + + + align:start position:0% +nice regular grid on a you know Square +grid packing is not very efficient for + + align:start position:0% +grid packing is not very efficient for + + + align:start position:0% +grid packing is not very efficient for +discs um but if you have these four + + align:start position:0% +discs um but if you have these four + + + align:start position:0% +discs um but if you have these four +really big discs I should mention here + + align:start position:0% +really big discs I should mention here + + + align:start position:0% +really big discs I should mention here +the the goal is for the disc to fit uh + + align:start position:0% +the the goal is for the disc to fit uh + + + align:start position:0% +the the goal is for the disc to fit uh +the centers of the disc to fit inside + + align:start position:0% +the centers of the disc to fit inside + + + align:start position:0% +the centers of the disc to fit inside +the square that turns out to be the + + align:start position:0% +the square that turns out to be the + + + align:start position:0% +the square that turns out to be the +right constraint from the origami + + align:start position:0% +right constraint from the origami + + + align:start position:0% +right constraint from the origami +perspective um so we make these four big + + align:start position:0% +perspective um so we make these four big + + + align:start position:0% +perspective um so we make these four big +discs they have to be at the corners + + align:start position:0% +discs they have to be at the corners + + + align:start position:0% +discs they have to be at the corners +then we make this big disc it has to be + + align:start position:0% +then we make this big disc it has to be + + + align:start position:0% +then we make this big disc it has to be +in the center these are all perfectly + + align:start position:0% +in the center these are all perfectly + + + align:start position:0% +in the center these are all perfectly +touching uh then we add these four discs + + align:start position:0% +touching uh then we add these four discs + + + align:start position:0% +touching uh then we add these four discs +and it forces a particular Arrangement + + align:start position:0% +and it forces a particular Arrangement + + + align:start position:0% +and it forces a particular Arrangement +here which is a little awkward to + + align:start position:0% +here which is a little awkward to + + + align:start position:0% +here which is a little awkward to +compute but you can uh + + align:start position:0% +compute but you can uh + + + align:start position:0% +compute but you can uh +and yes we do that four times then for + + align:start position:0% +and yes we do that four times then for + + + align:start position:0% +and yes we do that four times then for +each of these constructions this is the + + align:start position:0% +each of these constructions this is the + + + align:start position:0% +each of these constructions this is the +shape that we want we want these kind of + + align:start position:0% +shape that we want we want these kind of + + + align:start position:0% +shape that we want we want these kind of +equilateral triangle is uh gaps I say is + + align:start position:0% +equilateral triangle is uh gaps I say is + + + align:start position:0% +equilateral triangle is uh gaps I say is +because they're not straight sides + + align:start position:0% +because they're not straight sides + + + align:start position:0% +because they're not straight sides +they're Arc sides but it is per the + + align:start position:0% +they're Arc sides but it is per the + + + align:start position:0% +they're Arc sides but it is per the +centers form an equilateral triangle + + align:start position:0% +centers form an equilateral triangle + + + align:start position:0% +centers form an equilateral triangle +perfectly uh then we recurse so wherever + + align:start position:0% +perfectly uh then we recurse so wherever + + + align:start position:0% +perfectly uh then we recurse so wherever +we have a gap like that which is this + + align:start position:0% +we have a gap like that which is this + + + align:start position:0% +we have a gap like that which is this +thing uh then we add this Center guy and + + align:start position:0% +thing uh then we add this Center guy and + + + align:start position:0% +thing uh then we add this Center guy and +then we add these four discs again just + + align:start position:0% +then we add these four discs again just + + + align:start position:0% +then we add these four discs again just +like over here three times now of course + + align:start position:0% +like over here three times now of course + + + align:start position:0% +like over here three times now of course +we can't force the disc to go here but + + align:start position:0% +we can't force the disc to go here but + + + align:start position:0% +we can't force the disc to go here but +um they will + + align:start position:0% +um they will + + + align:start position:0% +um they will +uh this is a very symmetric construction + + align:start position:0% +uh this is a very symmetric construction + + + align:start position:0% +uh this is a very symmetric construction +so we're going to do this symmetrically + + align:start position:0% +so we're going to do this symmetrically + + + align:start position:0% +so we're going to do this symmetrically +on all the things uh the other challenge + + align:start position:0% +on all the things uh the other challenge + + + align:start position:0% +on all the things uh the other challenge +is we left these rather large gaps here + + align:start position:0% +is we left these rather large gaps here + + + align:start position:0% +is we left these rather large gaps here +I mean relative to these tiny discs + + align:start position:0% +I mean relative to these tiny discs + + + align:start position:0% +I mean relative to these tiny discs +which are all fit inside that Gap um + + align:start position:0% +which are all fit inside that Gap um + + + align:start position:0% +which are all fit inside that Gap um +this is pretty big gap so we also have + + align:start position:0% +this is pretty big gap so we also have + + + align:start position:0% +this is pretty big gap so we also have +to make these gaps unusable by adding a + + align:start position:0% +to make these gaps unusable by adding a + + + align:start position:0% +to make these gaps unusable by adding a +maximal disc and then adding maximal + + align:start position:0% +maximal disc and then adding maximal + + + align:start position:0% +maximal disc and then adding maximal +disc and just recursively adding maximal + + align:start position:0% +disc and just recursively adding maximal + + + align:start position:0% +disc and just recursively adding maximal +disc until the gaps that are left are + + align:start position:0% +disc until the gaps that are left are + + + align:start position:0% +disc until the gaps that are left are +tinier than all the ones that we're + + align:start position:0% +tinier than all the ones that we're + + + align:start position:0% +tinier than all the ones that we're +going to produce in this recursion this + + align:start position:0% +going to produce in this recursion this + + + align:start position:0% +going to produce in this recursion this +recursion as depth like log n so we get + + align:start position:0% +recursion as depth like log n so we get + + + align:start position:0% +recursion as depth like log n so we get +in the end we get uh roughly n of these + + align:start position:0% +in the end we get uh roughly n of these + + + align:start position:0% +in the end we get uh roughly n of these +things or n over three if we have extras + + align:start position:0% +things or n over three if we have extras + + + align:start position:0% +things or n over three if we have extras +we'll just throw in maximal discs and + + align:start position:0% +we'll just throw in maximal discs and + + + align:start position:0% +we'll just throw in maximal discs and +make them + + align:start position:0% +make them + + + align:start position:0% +make them +unusable uh so that's + + align:start position:0% +unusable uh so that's + + + align:start position:0% +unusable uh so that's +it uh so this is a lot harder because + + align:start position:0% +it uh so this is a lot harder because + + + align:start position:0% +it uh so this is a lot harder because +you have to fill in all of these gaps + + align:start position:0% +you have to fill in all of these gaps + + + align:start position:0% +you have to fill in all of these gaps +and make sure everything is going to be + + align:start position:0% +and make sure everything is going to be + + + align:start position:0% +and make sure everything is going to be +happy and no disc can go in the wrong + + align:start position:0% +happy and no disc can go in the wrong + + + align:start position:0% +happy and no disc can go in the wrong +place but if you sort of do it in the + + align:start position:0% +place but if you sort of do it in the + + + align:start position:0% +place but if you sort of do it in the +right order you can be convinced at + + align:start position:0% +right order you can be convinced at + + + align:start position:0% +right order you can be convinced at +every stage your dis has to go where + + align:start position:0% +every stage your dis has to go where + + + align:start position:0% +every stage your dis has to go where +you're putting it except at the very end + + align:start position:0% +you're putting it except at the very end + + + align:start position:0% +you're putting it except at the very end +where you have Freedom the freedom you + + align:start position:0% +where you have Freedom the freedom you + + + align:start position:0% +where you have Freedom the freedom you +have is where the AIS go which pocket + + align:start position:0% +have is where the AIS go which pocket + + + align:start position:0% +have is where the AIS go which pocket +they belong to that's the only Freedom + + align:start position:0% +they belong to that's the only Freedom + + + align:start position:0% +they belong to that's the only Freedom +you have it's the only Freedom we want + + align:start position:0% +you have it's the only Freedom we want + + + align:start position:0% +you have it's the only Freedom we want +you to + + align:start position:0% +you to + + + align:start position:0% +you to +have + + align:start position:0% +have + + + align:start position:0% +have +okay so that was dis packing next is + + align:start position:0% +okay so that was dis packing next is + + + align:start position:0% +okay so that was dis packing next is +Click Mania how many people have played + + align:start position:0% +Click Mania how many people have played + + + align:start position:0% +Click Mania how many people have played +click Mania a few good it's not + + align:start position:0% +click Mania a few good it's not + + + align:start position:0% +click Mania a few good it's not +completely obscure yet um so here here I + + align:start position:0% +completely obscure yet um so here here I + + + align:start position:0% +completely obscure yet um so here here I +have the real thing I think this is + + align:start position:0% +have the real thing I think this is + + + align:start position:0% +have the real thing I think this is +called click Next Generation and I want + + align:start position:0% +called click Next Generation and I want + + + align:start position:0% +called click Next Generation and I want +to start a new game so I don't have a + + align:start position:0% +to start a new game so I don't have a + + + align:start position:0% +to start a new game so I don't have a +really bad score uh so the idea is + + align:start position:0% +really bad score uh so the idea is + + + align:start position:0% +really bad score uh so the idea is +you're going to click on a group a + + align:start position:0% +you're going to click on a group a + + + align:start position:0% +you're going to click on a group a +connected group of one color that group + + align:start position:0% +connected group of one color that group + + + align:start position:0% +connected group of one color that group +is destroyed and then Things Fall + + align:start position:0% +is destroyed and then Things Fall + + + align:start position:0% +is destroyed and then Things Fall +vertically uh so column by + + align:start position:0% +vertically uh so column by + + + align:start position:0% +vertically uh so column by +column rules clear uh your goal is to + + align:start position:0% +column rules clear uh your goal is to + + + align:start position:0% +column rules clear uh your goal is to +remove all of the + + align:start position:0% +remove all of the + + + align:start position:0% +remove all of the +blocks uh which I probably won't succeed + + align:start position:0% +blocks uh which I probably won't succeed + + + align:start position:0% +blocks uh which I probably won't succeed +in doing I haven't played in a long + + align:start position:0% +in doing I haven't played in a long + + + align:start position:0% +in doing I haven't played in a long +time but let's I would like to show you + + align:start position:0% +time but let's I would like to show you + + + align:start position:0% +time but let's I would like to show you +one other rule but I may fail to do + + align:start position:0% +one other rule but I may fail to do + + + align:start position:0% +one other rule but I may fail to do +so uh + + align:start position:0% + + + + align:start position:0% + +progress uh this kind of checkerboarding + + align:start position:0% +progress uh this kind of checkerboarding + + + align:start position:0% +progress uh this kind of checkerboarding +not so + + align:start position:0% +not so + + + align:start position:0% +not so +good don't do that when you play uh also + + align:start position:0% +good don't do that when you play uh also + + + align:start position:0% +good don't do that when you play uh also +very bad okay uh the one rule which I + + align:start position:0% +very bad okay uh the one rule which I + + + align:start position:0% +very bad okay uh the one rule which I +won't demonstrate here uh is if you + + align:start position:0% +won't demonstrate here uh is if you + + + align:start position:0% +won't demonstrate here uh is if you +clear a column then these guys just sort + + align:start position:0% +clear a column then these guys just sort + + + align:start position:0% +clear a column then these guys just sort +of eat the column they just move closer + + align:start position:0% +of eat the column they just move closer + + + align:start position:0% +of eat the column they just move closer +to each other I think usually the Right + + align:start position:0% +to each other I think usually the Right + + + align:start position:0% +to each other I think usually the Right +Moves to the left one one step okay so + + align:start position:0% +Moves to the left one one step okay so + + + align:start position:0% +Moves to the left one one step okay so +that's uh here here's a successful + + align:start position:0% +that's uh here here's a successful + + + align:start position:0% +that's uh here here's a successful +execution from The Click Mania website + + align:start position:0% +execution from The Click Mania website + + + align:start position:0% +execution from The Click Mania website +um but I have done it a few times just + + align:start position:0% +um but I have done it a few times just + + + align:start position:0% +um but I have done it a few times just +haven't in a long time the Only Rule is + + align:start position:0% +haven't in a long time the Only Rule is + + + align:start position:0% +haven't in a long time the Only Rule is +you C the group that you click on the + + align:start position:0% +you C the group that you click on the + + + align:start position:0% +you C the group that you click on the +connected uh color chunk has to be of + + align:start position:0% +connected uh color chunk has to be of + + + align:start position:0% +connected uh color chunk has to be of +size greater than one otherwise you + + align:start position:0% +size greater than one otherwise you + + + align:start position:0% +size greater than one otherwise you +could just keep clicking on everything + + align:start position:0% +could just keep clicking on everything + + + align:start position:0% +could just keep clicking on everything +uh so that's why the checkerboarding is + + align:start position:0% +uh so that's why the checkerboarding is + + + align:start position:0% +uh so that's why the checkerboarding is +bad because there you have single + + align:start position:0% +bad because there you have single + + + align:start position:0% +bad because there you have single +Singleton + + align:start position:0% +Singleton + + + align:start position:0% +Singleton +guys so you may have some Singleton guys + + align:start position:0% +guys so you may have some Singleton guys + + + align:start position:0% +guys so you may have some Singleton guys +but if you're careful you sometimes can + + align:start position:0% +but if you're careful you sometimes can + + + align:start position:0% +but if you're careful you sometimes can +get rid of them question is when can you + + align:start position:0% +get rid of them question is when can you + + + align:start position:0% +get rid of them question is when can you +uh and and the answer is it's NP + + align:start position:0% +uh and and the answer is it's NP + + + align:start position:0% +uh and and the answer is it's NP +complete so this was actually uh my + + align:start position:0% +complete so this was actually uh my + + + align:start position:0% +complete so this was actually uh my +first NP hardness proof I think ever + + align:start position:0% +first NP hardness proof I think ever + + + align:start position:0% +first NP hardness proof I think ever +definitely of a game um I think ever so + + align:start position:0% +definitely of a game um I think ever so + + + align:start position:0% +definitely of a game um I think ever so +there's a few results here one is that + + align:start position:0% +there's a few results here one is that + + + align:start position:0% +there's a few results here one is that +if you have a single column that case we + + align:start position:0% +if you have a single column that case we + + + align:start position:0% +if you have a single column that case we +can solve a single row single row + + align:start position:0% +can solve a single row single row + + + align:start position:0% +can solve a single row single row +actually behaves the same as a single + + align:start position:0% +actually behaves the same as a single + + + align:start position:0% +actually behaves the same as a single +column uh because even though they're + + align:start position:0% +column uh because even though they're + + + align:start position:0% +column uh because even though they're +asymmetric in general for when it's one + + align:start position:0% +asymmetric in general for when it's one + + + align:start position:0% +asymmetric in general for when it's one +they're the same and if you happen to + + align:start position:0% +they're the same and if you happen to + + + align:start position:0% +they're the same and if you happen to +know context free grammars then uh here + + align:start position:0% +know context free grammars then uh here + + + align:start position:0% +know context free grammars then uh here +is the answer it's not obvious that this + + align:start position:0% +is the answer it's not obvious that this + + + align:start position:0% +is the answer it's not obvious that this +is the answer but this is saying + + align:start position:0% +is the answer but this is saying + + + align:start position:0% +is the answer but this is saying +something like well it could be you + + align:start position:0% +something like well it could be you + + + align:start position:0% +something like well it could be you +already solved the game that's the empty + + align:start position:0% +already solved the game that's the empty + + + align:start position:0% +already solved the game that's the empty +string or it could be you have a + + align:start position:0% +string or it could be you have a + + + align:start position:0% +string or it could be you have a +solvable game followed by solvable game + + align:start position:0% +solvable game followed by solvable game + + + align:start position:0% +solvable game followed by solvable game +you could just sort of do them + + align:start position:0% +you could just sort of do them + + + align:start position:0% +you could just sort of do them +separately and if you're careful they + + align:start position:0% +separately and if you're careful they + + + align:start position:0% +separately and if you're careful they +won't mess each other up and then you + + align:start position:0% +won't mess each other up and then you + + + align:start position:0% +won't mess each other up and then you +solve the overall game or it could be + + align:start position:0% +solve the overall game or it could be + + + align:start position:0% +solve the overall game or it could be +you have a solvable game and you have uh + + align:start position:0% +you have a solvable game and you have uh + + + align:start position:0% +you have a solvable game and you have uh +the same color one block of the same + + align:start position:0% +the same color one block of the same + + + align:start position:0% +the same color one block of the same +color on either side that would also be + + align:start position:0% +color on either side that would also be + + + align:start position:0% +color on either side that would also be +solvable because you could just solve + + align:start position:0% +solvable because you could just solve + + + align:start position:0% +solvable because you could just solve +the center thing then these two guys + + align:start position:0% +the center thing then these two guys + + + align:start position:0% +the center thing then these two guys +come together and then you click that + + align:start position:0% +come together and then you click that + + + align:start position:0% +come together and then you click that +group of size two uh or this could also + + align:start position:0% +group of size two uh or this could also + + + align:start position:0% +group of size two uh or this could also +happen where you solve two things and + + align:start position:0% +happen where you solve two things and + + + align:start position:0% +happen where you solve two things and +then three blocks come together and you + + align:start position:0% +then three blocks come together and you + + + align:start position:0% +then three blocks come together and you +could also Imagine other rules but it + + align:start position:0% +could also Imagine other rules but it + + + align:start position:0% +could also Imagine other rules but it +turns out these are enough rules to + + align:start position:0% +turns out these are enough rules to + + + align:start position:0% +turns out these are enough rules to +capture all solvable puzzles for one row + + align:start position:0% +capture all solvable puzzles for one row + + + align:start position:0% +capture all solvable puzzles for one row +or column but that's not a hardness + + align:start position:0% +or column but that's not a hardness + + + align:start position:0% +or column but that's not a hardness +proof so we won't talk about it um we + + align:start position:0% +proof so we won't talk about it um we + + + align:start position:0% +proof so we won't talk about it um we +have two NP hardness results one is for + + align:start position:0% +have two NP hardness results one is for + + + align:start position:0% +have two NP hardness results one is for +two columns and five colors and the + + align:start position:0% +two columns and five colors and the + + + align:start position:0% +two columns and five colors and the +other one is a hardness proof for five + + align:start position:0% +other one is a hardness proof for five + + + align:start position:0% +other one is a hardness proof for five +columns and three + + align:start position:0% +columns and three + + + align:start position:0% +columns and three +colors um and these are the proofs + + align:start position:0% +colors um and these are the proofs + + + align:start position:0% +colors um and these are the proofs +uh this one is three partition this one + + align:start position:0% +uh this one is three partition this one + + + align:start position:0% +uh this one is three partition this one +is threat so we might talk about that in + + align:start position:0% +is threat so we might talk about that in + + + align:start position:0% +is threat so we might talk about that in +the threat section of the class but I'm + + align:start position:0% +the threat section of the class but I'm + + + align:start position:0% +the threat section of the class but I'm +going to focus here on the three + + align:start position:0% +going to focus here on the three + + + align:start position:0% +going to focus here on the three +partition two columns five colors open + + align:start position:0% +partition two columns five colors open + + + align:start position:0% +partition two columns five colors open +problem um is whether two colors you can + + align:start position:0% +problem um is whether two colors you can + + + align:start position:0% +problem um is whether two colors you can +get any hardness question um is it + + align:start position:0% +get any hardness question um is it + + + align:start position:0% +get any hardness question um is it +obvious that s to SS is a no it's not + + align:start position:0% +obvious that s to SS is a no it's not + + + align:start position:0% +obvious that s to SS is a no it's not +obvious that s to SS is valid because + + align:start position:0% +obvious that s to SS is valid because + + + align:start position:0% +obvious that s to SS is valid because +you worry that when you solve one of + + align:start position:0% +you worry that when you solve one of + + + align:start position:0% +you worry that when you solve one of +them you might eat a group from the + + align:start position:0% +them you might eat a group from the + + + align:start position:0% +them you might eat a group from the +right hand side uh but you can prove + + align:start position:0% +right hand side uh but you can prove + + + align:start position:0% +right hand side uh but you can prove +it's always possible I don't remember + + align:start position:0% +it's always possible I don't remember + + + align:start position:0% +it's always possible I don't remember +how that proof works but you can check + + align:start position:0% +how that proof works but you can check + + + align:start position:0% +how that proof works but you can check +the paper um yeah if you look at the if + + align:start position:0% +the paper um yeah if you look at the if + + + align:start position:0% +the paper um yeah if you look at the if +you ever go to the course website and + + align:start position:0% +you ever go to the course website and + + + align:start position:0% +you ever go to the course website and +look watch this lecture or click around + + align:start position:0% +look watch this lecture or click around + + + align:start position:0% +look watch this lecture or click around +the slides of this lecture it has links + + align:start position:0% +the slides of this lecture it has links + + + align:start position:0% +the slides of this lecture it has links +to all the papers that I'm talking about + + align:start position:0% +to all the papers that I'm talking about + + + align:start position:0% +to all the papers that I'm talking about +so if you ever want to know more details + + align:start position:0% +so if you ever want to know more details + + + align:start position:0% +so if you ever want to know more details +just go there link is right there you + + align:start position:0% +just go there link is right there you + + + align:start position:0% +just go there link is right there you +don't have to type in all these names + + align:start position:0% +don't have to type in all these names + + + align:start position:0% +don't have to type in all these names +and Google for + + align:start position:0% +and Google for + + + align:start position:0% +and Google for +it cool so uh this is my attempt at + + align:start position:0% +it cool so uh this is my attempt at + + + align:start position:0% +it cool so uh this is my attempt at +drawing the hardness proof this uh uh + + align:start position:0% +drawing the hardness proof this uh uh + + + align:start position:0% +drawing the hardness proof this uh uh +this was challenging and I should say + + align:start position:0% +this was challenging and I should say + + + align:start position:0% +this was challenging and I should say +it's not drawn to + + align:start position:0% +it's not drawn to + + + align:start position:0% +it's not drawn to +scale um so it's not exactly right but + + align:start position:0% +scale um so it's not exactly right but + + + align:start position:0% +scale um so it's not exactly right but +it gives you a flavor of what happens + + align:start position:0% +it gives you a flavor of what happens + + + align:start position:0% +it gives you a flavor of what happens +and I believe all the braces are correct + + align:start position:0% +and I believe all the braces are correct + + + align:start position:0% +and I believe all the braces are correct +uh but it just wouldn't fit on the + + align:start position:0% +uh but it just wouldn't fit on the + + + align:start position:0% +uh but it just wouldn't fit on the +screen if we drew everything properly to + + align:start position:0% +screen if we drew everything properly to + + + align:start position:0% +screen if we drew everything properly to +scale um + + align:start position:0% +scale um + + + align:start position:0% +scale um +so reduction from three partition we + + align:start position:0% +so reduction from three partition we + + + align:start position:0% +so reduction from three partition we +have n numbers A1 through a n integers + + align:start position:0% +have n numbers A1 through a n integers + + + align:start position:0% +have n numbers A1 through a n integers +we're going to scale everything up we're + + align:start position:0% +we're going to scale everything up we're + + + align:start position:0% +we're going to scale everything up we're +going to scale the AIS and T by a factor + + align:start position:0% +going to scale the AIS and T by a factor + + + align:start position:0% +going to scale the AIS and T by a factor +of B B is 4/3 n i don't totally know why + + align:start position:0% +of B B is 4/3 n i don't totally know why + + + align:start position:0% +of B B is 4/3 n i don't totally know why +but you know it's it's n plus the number + + align:start position:0% +but you know it's it's n plus the number + + + align:start position:0% +but you know it's it's n plus the number +of + + align:start position:0% +of + + + align:start position:0% +of +groups um I'm guessing a larger number + + align:start position:0% +groups um I'm guessing a larger number + + + align:start position:0% +groups um I'm guessing a larger number +would also work but that's uh definitely + + align:start position:0% +would also work but that's uh definitely + + + align:start position:0% +would also work but that's uh definitely +enough okay so basically the there's two + + align:start position:0% +enough okay so basically the there's two + + + align:start position:0% +enough okay so basically the there's two +columns remember always going to stay in + + align:start position:0% +columns remember always going to stay in + + + align:start position:0% +columns remember always going to stay in +two columns it never increases um there + + align:start position:0% +two columns it never increases um there + + + align:start position:0% +two columns it never increases um there +are some clickable blocks uh clickable + + align:start position:0% +are some clickable blocks uh clickable + + + align:start position:0% +are some clickable blocks uh clickable +groups which correspond to the AIS so + + align:start position:0% +groups which correspond to the AIS so + + + align:start position:0% +groups which correspond to the AIS so +for every AI you're gonna have exactly + + align:start position:0% +for every AI you're gonna have exactly + + + align:start position:0% +for every AI you're gonna have exactly +one block which is B time AI by + + align:start position:0% +one block which is B time AI by + + + align:start position:0% +one block which is B time AI by +one uh these h i don't draw the lines + + align:start position:0% +one uh these h i don't draw the lines + + + align:start position:0% +one uh these h i don't draw the lines +when they're in the same connected + + align:start position:0% +when they're in the same connected + + + align:start position:0% +when they're in the same connected +component but technically these are + + align:start position:0% +component but technically these are + + + align:start position:0% +component but technically these are +separate + + align:start position:0% +separate + + + align:start position:0% +separate +squares um there's also some clickable + + align:start position:0% +squares um there's also some clickable + + + align:start position:0% +squares um there's also some clickable +things up here uh that's those are not + + align:start position:0% +things up here uh that's those are not + + + align:start position:0% +things up here uh that's those are not +too essential they're basically to + + align:start position:0% +too essential they're basically to + + + align:start position:0% +too essential they're basically to +spread out these Red + + align:start position:0% +spread out these Red + + + align:start position:0% +spread out these Red +Blocks there are n over3 Red Blocks here + + align:start position:0% +Blocks there are n over3 Red Blocks here + + + align:start position:0% +Blocks there are n over3 Red Blocks here +and there n over3 Red Blocks here you + + align:start position:0% +and there n over3 Red Blocks here you + + + align:start position:0% +and there n over3 Red Blocks here you +will never win the game unless you + + align:start position:0% +will never win the game unless you + + + align:start position:0% +will never win the game unless you +destroy these Red Blocks so uh for + + align:start position:0% +destroy these Red Blocks so uh for + + + align:start position:0% +destroy these Red Blocks so uh for +example you could click all these blue + + align:start position:0% +example you could click all these blue + + + align:start position:0% +example you could click all these blue +things make the red together and then + + align:start position:0% +things make the red together and then + + + align:start position:0% +things make the red together and then +destroy the red but that's not a good + + align:start position:0% +destroy the red but that's not a good + + + align:start position:0% +destroy the red but that's not a good +idea um because these These are only + + align:start position:0% +idea um because these These are only + + + align:start position:0% +idea um because these These are only +this is a very small space uh this is a + + align:start position:0% +this is a very small space uh this is a + + + align:start position:0% +this is a very small space uh this is a +relatively large gap I know it doesn't + + align:start position:0% +relatively large gap I know it doesn't + + + align:start position:0% +relatively large gap I know it doesn't +look like it but this is only n over3 + + align:start position:0% +look like it but this is only n over3 + + + align:start position:0% +look like it but this is only n over3 +total the gap between these two things + + align:start position:0% +total the gap between these two things + + + align:start position:0% +total the gap between these two things +is B * T which is way bigger than n + + align:start position:0% +is B * T which is way bigger than n + + + align:start position:0% +is B * T which is way bigger than n +over3 okay so there's big gaps between + + align:start position:0% +over3 okay so there's big gaps between + + + align:start position:0% +over3 okay so there's big gaps between +these red guys uh so what you're + + align:start position:0% +these red guys uh so what you're + + + align:start position:0% +these red guys uh so what you're +basically going to do is make this + + align:start position:0% +basically going to do is make this + + + align:start position:0% +basically going to do is make this +column fall down until the first red guy + + align:start position:0% +column fall down until the first red guy + + + align:start position:0% +column fall down until the first red guy +aligns with this one then you delete + + align:start position:0% +aligns with this one then you delete + + + align:start position:0% +aligns with this one then you delete +those two then you're going to make it + + align:start position:0% +those two then you're going to make it + + + align:start position:0% +those two then you're going to make it +fall down farther until this red guy + + align:start position:0% +fall down farther until this red guy + + + align:start position:0% +fall down farther until this red guy +hits this one and then you can delete + + align:start position:0% +hits this one and then you can delete + + + align:start position:0% +hits this one and then you can delete +those two just two at a time then we're + + align:start position:0% +those two just two at a time then we're + + + align:start position:0% +those two just two at a time then we're +going to bring it down till the third + + align:start position:0% +going to bring it down till the third + + + align:start position:0% +going to bring it down till the third +guy hits the third guy and then the + + align:start position:0% +guy hits the third guy and then the + + + align:start position:0% +guy hits the third guy and then the +fourth guy hits the fourth guy then the + + align:start position:0% +fourth guy hits the fourth guy then the + + + align:start position:0% +fourth guy hits the fourth guy then the +reds are + + align:start position:0% +reds are + + + align:start position:0% +reds are +gone uh before I get to how that happens + + align:start position:0% +gone uh before I get to how that happens + + + align:start position:0% +gone uh before I get to how that happens +let me tell you what happens when the + + align:start position:0% +let me tell you what happens when the + + + align:start position:0% +let me tell you what happens when the +reds are gone uh when the reds are gone + + align:start position:0% +reds are gone uh when the reds are gone + + + align:start position:0% +reds are gone uh when the reds are gone +I mean if there are any purples left + + align:start position:0% +I mean if there are any purples left + + + align:start position:0% +I mean if there are any purples left +turns out there won't be but you could + + align:start position:0% +turns out there won't be but you could + + + align:start position:0% +turns out there won't be but you could +click them all then you could click all + + align:start position:0% +click them all then you could click all + + + align:start position:0% +click them all then you could click all +the blue then you're done on the right + + align:start position:0% +the blue then you're done on the right + + + align:start position:0% +the blue then you're done on the right +column so right column was finishable no + + align:start position:0% +column so right column was finishable no + + + align:start position:0% +column so right column was finishable no +problem uh once you've gotten rid of the + + align:start position:0% +problem uh once you've gotten rid of the + + + align:start position:0% +problem uh once you've gotten rid of the +red now this the left column is a mostly + + align:start position:0% +red now this the left column is a mostly + + + align:start position:0% +red now this the left column is a mostly +checkerboard and if you remove the red + + align:start position:0% +checkerboard and if you remove the red + + + align:start position:0% +checkerboard and if you remove the red +uh pixels you're left with exactly a + + align:start position:0% +uh pixels you're left with exactly a + + + align:start position:0% +uh pixels you're left with exactly a +checkerboard except here the topmost red + + align:start position:0% +checkerboard except here the topmost red + + + align:start position:0% +checkerboard except here the topmost red +guy there's it's white on either side + + align:start position:0% +guy there's it's white on either side + + + align:start position:0% +guy there's it's white on either side +and in general everything below this + + align:start position:0% +and in general everything below this + + + align:start position:0% +and in general everything below this +point is the same as everything above + + align:start position:0% +point is the same as everything above + + + align:start position:0% +point is the same as everything above +this point upside down down and so then + + align:start position:0% +this point upside down down and so then + + + align:start position:0% +this point upside down down and so then +you can always just click on the center + + align:start position:0% +you can always just click on the center + + + align:start position:0% +you can always just click on the center +Center Center Center I guess you have to + + align:start position:0% +Center Center Center I guess you have to + + + align:start position:0% +Center Center Center I guess you have to +move your mouse down as that happens but + + align:start position:0% +move your mouse down as that happens but + + + align:start position:0% +move your mouse down as that happens but +uh you will then destroy the black and + + align:start position:0% +uh you will then destroy the black and + + + align:start position:0% +uh you will then destroy the black and +white part total is five colors we've + + align:start position:0% +white part total is five colors we've + + + align:start position:0% +white part total is five colors we've +got red purple blue black and + + align:start position:0% +got red purple blue black and + + + align:start position:0% +got red purple blue black and +white okay uh now this is my attempt at + + align:start position:0% +white okay uh now this is my attempt at + + + align:start position:0% +white okay uh now this is my attempt at +showing you uh how we get the red things + + align:start position:0% +showing you uh how we get the red things + + + align:start position:0% +showing you uh how we get the red things +to align but the the idea is simple uh + + align:start position:0% +to align but the the idea is simple uh + + + align:start position:0% +to align but the the idea is simple uh +these the initial Gap from this guy to + + align:start position:0% +these the initial Gap from this guy to + + + align:start position:0% +these the initial Gap from this guy to +this guy and then the Gap henceforth + + align:start position:0% +this guy and then the Gap henceforth + + + align:start position:0% +this guy and then the Gap henceforth +from this one to this one to this one is + + align:start position:0% +from this one to this one to this one is + + + align:start position:0% +from this one to this one to this one is +always B * t plus some constant uh the + + align:start position:0% +always B * t plus some constant uh the + + + align:start position:0% +always B * t plus some constant uh the +constants are just annoying um so + + align:start position:0% +constants are just annoying um so + + + align:start position:0% +constants are just annoying um so +they're not essential the idea is well + + align:start position:0% +they're not essential the idea is well + + + align:start position:0% +they're not essential the idea is well +I've got to bring this down B * T so in + + align:start position:0% +I've got to bring this down B * T so in + + + align:start position:0% +I've got to bring this down B * T so in +order to do that I'm going to click on + + align:start position:0% +order to do that I'm going to click on + + + align:start position:0% +order to do that I'm going to click on +some purple things whose total size is B + + align:start position:0% +some purple things whose total size is B + + + align:start position:0% +some purple things whose total size is B +* T in other words the sum of the AIS + + align:start position:0% +* T in other words the sum of the AIS + + + align:start position:0% +* T in other words the sum of the AIS +that I'm clicking on should be equal to + + align:start position:0% +that I'm clicking on should be equal to + + + align:start position:0% +that I'm clicking on should be equal to +t uh and we happen to know that will be + + align:start position:0% +t uh and we happen to know that will be + + + align:start position:0% +t uh and we happen to know that will be +three things but uh that's not essential + + align:start position:0% +three things but uh that's not essential + + + align:start position:0% +three things but uh that's not essential +here we can just use the simple version + + align:start position:0% +here we can just use the simple version + + + align:start position:0% +here we can just use the simple version +of three partition where you're asking + + align:start position:0% +of three partition where you're asking + + + align:start position:0% +of three partition where you're asking +for sets that happen to sum to t uh and + + align:start position:0% +for sets that happen to sum to t uh and + + + align:start position:0% +for sets that happen to sum to t uh and +because everything is scaled up so big + + align:start position:0% +because everything is scaled up so big + + + align:start position:0% +because everything is scaled up so big +by these factors of B I mean these gaps + + align:start position:0% +by these factors of B I mean these gaps + + + align:start position:0% +by these factors of B I mean these gaps +you have to even to get in in the right + + align:start position:0% +you have to even to get in in the right + + + align:start position:0% +you have to even to get in in the right +proximity you have to choose AIS that + + align:start position:0% +proximity you have to choose AIS that + + + align:start position:0% +proximity you have to choose AIS that +sum to exactly + + align:start position:0% +sum to exactly + + + align:start position:0% +sum to exactly +T + + align:start position:0% +T + + + align:start position:0% +T +um yes so the constants are annoying + + align:start position:0% +um yes so the constants are annoying + + + align:start position:0% +um yes so the constants are annoying +because uh you want to make sure so here + + align:start position:0% +because uh you want to make sure so here + + + align:start position:0% +because uh you want to make sure so here +here's an example here are are in this + + align:start position:0% +here's an example here are are in this + + + align:start position:0% +here's an example here are are in this +particular picture the height of one of + + align:start position:0% +particular picture the height of one of + + + align:start position:0% +particular picture the height of one of +these things is six and so I click on + + align:start position:0% +these things is six and so I click on + + + align:start position:0% +these things is six and so I click on +one purple thing of size four and one + + align:start position:0% +one purple thing of size four and one + + + align:start position:0% +one purple thing of size four and one +purple thing of size two in reality + + align:start position:0% +purple thing of size two in reality + + + align:start position:0% +purple thing of size two in reality +these numbers would be much bigger but + + align:start position:0% +these numbers would be much bigger but + + + align:start position:0% +these numbers would be much bigger but +for the picture that works then Things + + align:start position:0% +for the picture that works then Things + + + align:start position:0% +for the picture that works then Things +fall and we get this picture um and + + align:start position:0% +fall and we get this picture um and + + + align:start position:0% +fall and we get this picture um and +these red things are almost align but + + align:start position:0% +these red things are almost align but + + + align:start position:0% +these red things are almost align but +they're off by two so I click on this + + align:start position:0% +they're off by two so I click on this + + + align:start position:0% +they're off by two so I click on this +little one by two block and then they're + + align:start position:0% +little one by two block and then they're + + + align:start position:0% +little one by two block and then they're +aligned then I can click on the red + + align:start position:0% +aligned then I can click on the red + + + align:start position:0% +aligned then I can click on the red +thing um I also click on this blue thing + + align:start position:0% +thing um I also click on this blue thing + + + align:start position:0% +thing um I also click on this blue thing +to sort of advance to the next red thing + + align:start position:0% +to sort of advance to the next red thing + + + align:start position:0% +to sort of advance to the next red thing +and then these guys fall and I get this + + align:start position:0% +and then these guys fall and I get this + + + align:start position:0% +and then these guys fall and I get this +picture I could click on the white but + + align:start position:0% +picture I could click on the white but + + + align:start position:0% +picture I could click on the white but +it won't matter that's just I can do + + align:start position:0% +it won't matter that's just I can do + + + align:start position:0% +it won't matter that's just I can do +that all at the end later now my goal is + + align:start position:0% +that all at the end later now my goal is + + + align:start position:0% +that all at the end later now my goal is +to get this red thing to Here Again The + + align:start position:0% +to get this red thing to Here Again The + + + align:start position:0% +to get this red thing to Here Again The +Gap is exactly + + align:start position:0% +Gap is exactly + + + align:start position:0% +Gap is exactly +five so um I click on let's say two or + + align:start position:0% +five so um I click on let's say two or + + + align:start position:0% +five so um I click on let's say two or +sorry six uh let's say I click on two + + align:start position:0% +sorry six uh let's say I click on two + + + align:start position:0% +sorry six uh let's say I click on two +things of size three um and so then + + align:start position:0% +things of size three um and so then + + + align:start position:0% +things of size three um and so then +everything falls then the Red's a line + + align:start position:0% +everything falls then the Red's a line + + + align:start position:0% +everything falls then the Red's a line +then I delete it I also delete the blue + + align:start position:0% +then I delete it I also delete the blue + + + align:start position:0% +then I delete it I also delete the blue +thing to + + align:start position:0% +thing to + + + align:start position:0% +thing to +advance uh and I think that that works + + align:start position:0% +advance uh and I think that that works + + + align:start position:0% +advance uh and I think that that works +yeah question sure that it's always the + + align:start position:0% +yeah question sure that it's always the + + + align:start position:0% +yeah question sure that it's always the +leading red block that has to go with + + align:start position:0% +leading red block that has to go with + + + align:start position:0% +leading red block that has to go with +the um tra red block right so it could + + align:start position:0% +the um tra red block right so it could + + + align:start position:0% +the um tra red block right so it could +be you take some other block other red + + align:start position:0% +be you take some other block other red + + + align:start position:0% +be you take some other block other red +block and align it with this one um that + + align:start position:0% +block and align it with this one um that + + + align:start position:0% +block and align it with this one um that +is mostly a worry from a construction + + align:start position:0% +is mostly a worry from a construction + + + align:start position:0% +is mostly a worry from a construction +standpoint um if you did that you might + + align:start position:0% +standpoint um if you did that you might + + + align:start position:0% +standpoint um if you did that you might +get stuck uh but I claim if I do that + + align:start position:0% +get stuck uh but I claim if I do that + + + align:start position:0% +get stuck uh but I claim if I do that +it's it's never a problem to do that + + align:start position:0% +it's it's never a problem to do that + + + align:start position:0% +it's it's never a problem to do that +because this length is this total uh + + align:start position:0% +because this length is this total uh + + + align:start position:0% +because this length is this total uh +extent of these red guys is relatively + + align:start position:0% +extent of these red guys is relatively + + + align:start position:0% +extent of these red guys is relatively +small the whole length here is n sorry + + align:start position:0% +small the whole length here is n sorry + + + align:start position:0% +small the whole length here is n sorry +it's it's 3 * n over3 + + align:start position:0% +it's it's 3 * n over3 + + + align:start position:0% +it's it's 3 * n over3 +whole length is n whereas all these AIS + + align:start position:0% +whole length is n whereas all these AIS + + + align:start position:0% +whole length is n whereas all these AIS +are scaled by a factor of much bigger + + align:start position:0% +are scaled by a factor of much bigger + + + align:start position:0% +are scaled by a factor of much bigger +than n well not a huge amount bigger but + + align:start position:0% +than n well not a huge amount bigger but + + + align:start position:0% +than n well not a huge amount bigger but +bigger than n so even to get in vaguely + + align:start position:0% +bigger than n so even to get in vaguely + + + align:start position:0% +bigger than n so even to get in vaguely +the this is why I was saying what to get + + align:start position:0% +the this is why I was saying what to get + + + align:start position:0% +the this is why I was saying what to get +this red block or any of these Red + + align:start position:0% +this red block or any of these Red + + + align:start position:0% +this red block or any of these Red +Blocks near this one uh because these + + align:start position:0% +Blocks near this one uh because these + + + align:start position:0% +Blocks near this one uh because these +things are scaled so huge uh you to get + + align:start position:0% +things are scaled so huge uh you to get + + + align:start position:0% +things are scaled so huge uh you to get +one close is the same as getting all of + + align:start position:0% +one close is the same as getting all of + + + align:start position:0% +one close is the same as getting all of +them close so for if you happen to + + align:start position:0% +them close so for if you happen to + + + align:start position:0% +them close so for if you happen to +succeed in a way that gets the Reds to + + align:start position:0% +succeed in a way that gets the Reds to + + + align:start position:0% +succeed in a way that gets the Reds to +align in out of order that would still + + align:start position:0% +align in out of order that would still + + + align:start position:0% +align in out of order that would still +give a valid solution to three part + + align:start position:0% +give a valid solution to three part + + + align:start position:0% +give a valid solution to three part +that's the point because we SC + + align:start position:0% +that's the point because we SC + + + align:start position:0% +that's the point because we SC +everything so huge um + + align:start position:0% +everything so huge um + + + align:start position:0% +everything so huge um +the to do the other direction say if you + + align:start position:0% +the to do the other direction say if you + + + align:start position:0% +the to do the other direction say if you +have a solution to three partition then + + align:start position:0% +have a solution to three partition then + + + align:start position:0% +have a solution to three partition then +there's a solution to this instance + + align:start position:0% +there's a solution to this instance + + + align:start position:0% +there's a solution to this instance +there we do it in order so that we're in + + align:start position:0% +there we do it in order so that we're in + + + align:start position:0% +there we do it in order so that we're in +control and make sure every all the + + align:start position:0% +control and make sure every all the + + + align:start position:0% +control and make sure every all the +constants add up right and that's that's + + align:start position:0% +constants add up right and that's that's + + + align:start position:0% +constants add up right and that's that's +sort of the annoying part of this proof + + align:start position:0% +sort of the annoying part of this proof + + + align:start position:0% +sort of the annoying part of this proof +but this is a relatively easy proof + + align:start position:0% +but this is a relatively easy proof + + + align:start position:0% +but this is a relatively easy proof +except for these little additive + + align:start position:0% +except for these little additive + + + align:start position:0% +except for these little additive +constants to make sure everything lines + + align:start position:0% +constants to make sure everything lines + + + align:start position:0% +constants to make sure everything lines +up it would be great if I could just put + + align:start position:0% +up it would be great if I could just put + + + align:start position:0% +up it would be great if I could just put +these Reds on top of each other but then + + align:start position:0% +these Reds on top of each other but then + + + align:start position:0% +these Reds on top of each other but then +they're one group and you delete them + + align:start position:0% +they're one group and you delete them + + + align:start position:0% +they're one group and you delete them +all at once so I have to put these + + align:start position:0% +all at once so I have to put these + + + align:start position:0% +all at once so I have to put these +things in between they have to be length + + align:start position:0% +things in between they have to be length + + + align:start position:0% +things in between they have to be length +two so I can destroy them when I need + + align:start position:0% +two so I can destroy them when I need + + + align:start position:0% +two so I can destroy them when I need +whenever I want to and so all these + + align:start position:0% +whenever I want to and so all these + + + align:start position:0% +whenever I want to and so all these +additive constants kind of get in the + + align:start position:0% +additive constants kind of get in the + + + align:start position:0% +additive constants kind of get in the +way but um it's not too + + align:start position:0% +way but um it's not too + + + align:start position:0% +way but um it's not too +bad other questions about this + + align:start position:0% + + + + align:start position:0% + +proof that's click + + align:start position:0% + + + + align:start position:0% + +Mania cool next is + + align:start position:0% +Mania cool next is + + + align:start position:0% +Mania cool next is +Tetris as advertised in the original um + + align:start position:0% +Tetris as advertised in the original um + + + align:start position:0% +Tetris as advertised in the original um +first first lecture uh so if you haven't + + align:start position:0% +first first lecture uh so if you haven't + + + align:start position:0% +first first lecture uh so if you haven't +played + + align:start position:0% +played + + + align:start position:0% +played +Tetris here is the I hope you've played + + align:start position:0% +Tetris here is the I hope you've played + + + align:start position:0% +Tetris here is the I hope you've played +Tetris I played a lot as a kid uh you + + align:start position:0% +Tetris I played a lot as a kid uh you + + + align:start position:0% +Tetris I played a lot as a kid uh you +have these tetromino blocks you can + + align:start position:0% +have these tetromino blocks you can + + + align:start position:0% +have these tetromino blocks you can +rotate them and then you can Force drop + + align:start position:0% +rotate them and then you can Force drop + + + align:start position:0% +rotate them and then you can Force drop +them or you can slowly drop them and do + + align:start position:0% +them or you can slowly drop them and do + + + align:start position:0% +them or you can slowly drop them and do +weird things like that uh you know sort + + align:start position:0% +weird things like that uh you know sort + + + align:start position:0% +weird things like that uh you know sort +of last minute + + align:start position:0% +of last minute + + + align:start position:0% +of last minute +moves uh let + + align:start position:0% +moves uh let + + + align:start position:0% +moves uh let +see I don't think that's yeah the + + align:start position:0% +see I don't think that's yeah the + + + align:start position:0% +see I don't think that's yeah the +rotation centers are always a bit funny + + align:start position:0% +rotation centers are always a bit funny + + + align:start position:0% +rotation centers are always a bit funny +so you can do cool things uh so let's + + align:start position:0% +so you can do cool things uh so let's + + + align:start position:0% +so you can do cool things uh so let's +let's have some + + align:start position:0% +let's have some + + + align:start position:0% +let's have some +fun + + align:start position:0% + + + + align:start position:0% + +uh I'll just play Tetris for the rest of + + align:start position:0% +uh I'll just play Tetris for the rest of + + + align:start position:0% +uh I'll just play Tetris for the rest of +the + + align:start position:0% +the + + + align:start position:0% +the +class okay uh so important rule is when + + align:start position:0% +class okay uh so important rule is when + + + align:start position:0% +class okay uh so important rule is when +you complete a line then that line + + align:start position:0% +you complete a line then that line + + + align:start position:0% +you complete a line then that line +disappears although in the proof we will + + align:start position:0% +disappears although in the proof we will + + + align:start position:0% +disappears although in the proof we will +prevent that from happening uh it is a + + align:start position:0% +prevent that from happening uh it is a + + + align:start position:0% +prevent that from happening uh it is a +rule of the game that's + + align:start position:0% +rule of the game that's + + + align:start position:0% +rule of the game that's +annoying also annoying + + align:start position:0% +annoying also annoying + + + align:start position:0% +annoying also annoying +okay well you get the idea you're super + + align:start position:0% +okay well you get the idea you're super + + + align:start position:0% +okay well you get the idea you're super +impressed by my Tetris + + align:start position:0% + + + + align:start position:0% + +skills all right so um cool I used to + + align:start position:0% +skills all right so um cool I used to + + + align:start position:0% +skills all right so um cool I used to +play it on Game Boy but uh and then NES + + align:start position:0% +play it on Game Boy but uh and then NES + + + align:start position:0% +play it on Game Boy but uh and then NES +you can play it on the Green + + align:start position:0% +you can play it on the Green + + + align:start position:0% +you can play it on the Green +Building um this happened in 2012 + + align:start position:0% +Building um this happened in 2012 + + + align:start position:0% +Building um this happened in 2012 +finally after it was dreamed for many + + align:start position:0% +finally after it was dreamed for many + + + align:start position:0% +finally after it was dreamed for many +years uh I am a Tetris Master according + + align:start position:0% +years uh I am a Tetris Master according + + + align:start position:0% +years uh I am a Tetris Master according +to the Harvard Tetra Society uh this was + + align:start position:0% +to the Harvard Tetra Society uh this was + + + align:start position:0% +to the Harvard Tetra Society uh this was +for proving and I didn't have to play a + + align:start position:0% +for proving and I didn't have to play a + + + align:start position:0% +for proving and I didn't have to play a +game to as you can tell uh for proving + + align:start position:0% +game to as you can tell uh for proving + + + align:start position:0% +game to as you can tell uh for proving +NP completeness and maximization of + + align:start position:0% +NP completeness and maximization of + + + align:start position:0% +NP completeness and maximization of +lines tetrises pieces plate or + + align:start position:0% +lines tetrises pieces plate or + + + align:start position:0% +lines tetrises pieces plate or +minimization of square height we masters + + align:start position:0% +minimization of square height we masters + + + align:start position:0% +minimization of square height we masters +of the Harvard tet Society hereby confer + + align:start position:0% +of the Harvard tet Society hereby confer + + + align:start position:0% +of the Harvard tet Society hereby confer +the title of tetras Master Eric D demain + + align:start position:0% +the title of tetras Master Eric D demain + + + align:start position:0% +the title of tetras Master Eric D demain +on the 16th day of the 12th month in the + + align:start position:0% +on the 16th day of the 12th month in the + + + align:start position:0% +on the 16th day of the 12th month in the +year 17 anot tetri which is since the + + align:start position:0% +year 17 anot tetri which is since the + + + align:start position:0% +year 17 anot tetri which is since the +invention of + + align:start position:0% +invention of + + + align:start position:0% +invention of +Tetris okay uh this is a proof done + + align:start position:0% +Tetris okay uh this is a proof done + + + align:start position:0% +Tetris okay uh this is a proof done +early in my career at MIT uh with two + + align:start position:0% +early in my career at MIT uh with two + + + align:start position:0% +early in my career at MIT uh with two +MIT students uh David Lanell and Susan + + align:start position:0% +MIT students uh David Lanell and Susan + + + align:start position:0% +MIT students uh David Lanell and Susan +hoen bger um now professors at other + + align:start position:0% +hoen bger um now professors at other + + + align:start position:0% +hoen bger um now professors at other +schools this was a first attempt at a + + align:start position:0% +schools this was a first attempt at a + + + align:start position:0% +schools this was a first attempt at a +proof we had many attempts at appr proof + + align:start position:0% +proof we had many attempts at appr proof + + + align:start position:0% +proof we had many attempts at appr proof +many of which all of which were wrong + + align:start position:0% +many of which all of which were wrong + + + align:start position:0% +many of which all of which were wrong +except the last one um yeah anyway you + + align:start position:0% +except the last one um yeah anyway you + + + align:start position:0% +except the last one um yeah anyway you +could try to see what's wrong with that + + align:start position:0% +could try to see what's wrong with that + + + align:start position:0% +could try to see what's wrong with that +proof but uh here is a a working proof + + align:start position:0% +proof but uh here is a a working proof + + + align:start position:0% +proof but uh here is a a working proof +this is actually not the first working + + align:start position:0% +this is actually not the first working + + + align:start position:0% +this is actually not the first working +proof we had uh you so there's me David + + align:start position:0% +proof we had uh you so there's me David + + + align:start position:0% +proof we had uh you so there's me David +and Susan and then uh we published a + + align:start position:0% +and Susan and then uh we published a + + + align:start position:0% +and Susan and then uh we published a +much harder version of the proof with + + align:start position:0% +much harder version of the proof with + + + align:start position:0% +much harder version of the proof with +like 500 cases and then these three guys + + align:start position:0% +like 500 cases and then these three guys + + + align:start position:0% +like 500 cases and then these three guys +read our paper and said hey I think we + + align:start position:0% +read our paper and said hey I think we + + + align:start position:0% +read our paper and said hey I think we +can simplify it like this and then we + + align:start position:0% +can simplify it like this and then we + + + align:start position:0% +can simplify it like this and then we +wrote joint Journal version so um + + align:start position:0% +wrote joint Journal version so um + + + align:start position:0% +wrote joint Journal version so um +reduction is from three partition + + align:start position:0% +reduction is from three partition + + + align:start position:0% +reduction is from three partition +surprise um this is so I should say what + + align:start position:0% +surprise um this is so I should say what + + + align:start position:0% +surprise um this is so I should say what +does Tetris mean from a computational + + align:start position:0% +does Tetris mean from a computational + + + align:start position:0% +does Tetris mean from a computational +complexity standpoint there are multiple + + align:start position:0% +complexity standpoint there are multiple + + + align:start position:0% +complexity standpoint there are multiple +interpretations our interpretation is I + + align:start position:0% +interpretations our interpretation is I + + + align:start position:0% +interpretations our interpretation is I +give you an initial board because you've + + align:start position:0% +give you an initial board because you've + + + align:start position:0% +give you an initial board because you've +already been playing for a while here's + + align:start position:0% +already been playing for a while here's + + + align:start position:0% +already been playing for a while here's +what you're what you have and then I + + align:start position:0% +what you're what you have and then I + + + align:start position:0% +what you're what you have and then I +give you the entire sequence of pieces + + align:start position:0% +give you the entire sequence of pieces + + + align:start position:0% +give you the entire sequence of pieces +that's going to come and I want to know + + align:start position:0% +that's going to come and I want to know + + + align:start position:0% +that's going to come and I want to know +can you survive maximize a number of + + align:start position:0% +can you survive maximize a number of + + + align:start position:0% +can you survive maximize a number of +lines uh this is not yet the the + + align:start position:0% +lines uh this is not yet the the + + + align:start position:0% +lines uh this is not yet the the +approximability part of the class but we + + align:start position:0% +approximability part of the class but we + + + align:start position:0% +approximability part of the class but we +get some really easy inapproximability + + align:start position:0% +get some really easy inapproximability + + + align:start position:0% +get some really easy inapproximability +results so I will mention them for now + + align:start position:0% +results so I will mention them for now + + + align:start position:0% +results so I will mention them for now +it's just can you survive the the + + align:start position:0% +it's just can you survive the the + + + align:start position:0% +it's just can you survive the the +ceiling is like here a couple couple uh + + align:start position:0% +ceiling is like here a couple couple uh + + + align:start position:0% +ceiling is like here a couple couple uh +rows above this initial picture so + + align:start position:0% +rows above this initial picture so + + + align:start position:0% +rows above this initial picture so +you're almost dead so it's like every + + align:start position:0% +you're almost dead so it's like every + + + align:start position:0% +you're almost dead so it's like every +second counts all right your goal is to + + align:start position:0% +second counts all right your goal is to + + + align:start position:0% +second counts all right your goal is to +fill up these Chambers these + + align:start position:0% +fill up these Chambers these + + + align:start position:0% +fill up these Chambers these +bins uh exactly with no holes so if you + + align:start position:0% +bins uh exactly with no holes so if you + + + align:start position:0% +bins uh exactly with no holes so if you +can do it at the end I'm going to give + + align:start position:0% +can do it at the end I'm going to give + + + align:start position:0% +can do it at the end I'm going to give +you a t and then a whole bunch of + + align:start position:0% +you a t and then a whole bunch of + + + align:start position:0% +you a t and then a whole bunch of +straits and then you you can win the + + align:start position:0% +straits and then you you can win the + + + align:start position:0% +straits and then you you can win the +game all right so uh so we have n over3 + + align:start position:0% +game all right so uh so we have n over3 + + + align:start position:0% +game all right so uh so we have n over3 +of these buckets each one is roughly T + + align:start position:0% +of these buckets each one is roughly T + + + align:start position:0% +of these buckets each one is roughly T +tall uh there's some additive constant + + align:start position:0% +tall uh there's some additive constant + + + align:start position:0% +tall uh there's some additive constant +to deal with some stuff but uh there's T + + align:start position:0% +to deal with some stuff but uh there's T + + + align:start position:0% +to deal with some stuff but uh there's T +notches each of these is basically + + align:start position:0% +notches each of these is basically + + + align:start position:0% +notches each of these is basically +counting one unit of an + + align:start position:0% +counting one unit of an + + + align:start position:0% +counting one unit of an +integer + + align:start position:0% +integer + + + align:start position:0% +integer +okay uh yeah the point is if you don't + + align:start position:0% +okay uh yeah the point is if you don't + + + align:start position:0% +okay uh yeah the point is if you don't +open this thing where the is going to go + + align:start position:0% +open this thing where the is going to go + + + align:start position:0% +open this thing where the is going to go +and you will only be able to open this + + align:start position:0% +and you will only be able to open this + + + align:start position:0% +and you will only be able to open this +thing if this is full and this is full + + align:start position:0% +thing if this is full and this is full + + + align:start position:0% +thing if this is full and this is full +and this is full and this is full so + + align:start position:0% +and this is full and this is full so + + + align:start position:0% +and this is full and this is full so +you've got to get these perfect so that + + align:start position:0% +you've got to get these perfect so that + + + align:start position:0% +you've got to get these perfect so that +at the top you can open this and and + + align:start position:0% +at the top you can open this and and + + + align:start position:0% +at the top you can open this and and +then clear + + align:start position:0% +then clear + + + align:start position:0% +then clear +everything okay uh so here are the + + align:start position:0% +everything okay uh so here are the + + + align:start position:0% +everything okay uh so here are the +gadgets from the piece pers perspective + + align:start position:0% +gadgets from the piece pers perspective + + + align:start position:0% +gadgets from the piece pers perspective +that was the initial configuration of + + align:start position:0% +that was the initial configuration of + + + align:start position:0% +that was the initial configuration of +course there are no AIS yet so the piece + + align:start position:0% +course there are no AIS yet so the piece + + + align:start position:0% +course there are no AIS yet so the piece +sequence has to encode the AIS in uny + + align:start position:0% +sequence has to encode the AIS in uny + + + align:start position:0% +sequence has to encode the AIS in uny +because you there are only a constant + + align:start position:0% +because you there are only a constant + + + align:start position:0% +because you there are only a constant +number of different tetromino pieces uh + + align:start position:0% +number of different tetromino pieces uh + + + align:start position:0% +number of different tetromino pieces uh +so you have to encode well I guess you + + align:start position:0% +so you have to encode well I guess you + + + align:start position:0% +so you have to encode well I guess you +could try to encode in binary it's very + + align:start position:0% +could try to encode in binary it's very + + + align:start position:0% +could try to encode in binary it's very +hard to add uh when you're working with + + align:start position:0% +hard to add uh when you're working with + + + align:start position:0% +hard to add uh when you're working with +chromas unless you do it in uny so um + + align:start position:0% +chromas unless you do it in uny so um + + + align:start position:0% +chromas unless you do it in uny so um +here's the idea we have an initial setup + + align:start position:0% +here's the idea we have an initial setup + + + align:start position:0% +here's the idea we have an initial setup +like this it will always have this + + align:start position:0% +like this it will always have this + + + align:start position:0% +like this it will always have this +little thing in the corner and so to say + + align:start position:0% +little thing in the corner and so to say + + + align:start position:0% +little thing in the corner and so to say +hey new AI is starting we're going to + + align:start position:0% +hey new AI is starting we're going to + + + align:start position:0% +hey new AI is starting we're going to +give you uh might call this a right word + + align:start position:0% +give you uh might call this a right word + + + align:start position:0% +give you uh might call this a right word +pointing L if you look from the barrel + + align:start position:0% +pointing L if you look from the barrel + + + align:start position:0% +pointing L if you look from the barrel +of the gun then it goes to the right um + + align:start position:0% +of the gun then it goes to the right um + + + align:start position:0% +of the gun then it goes to the right um +so that makes a nice flat face here + + align:start position:0% +so that makes a nice flat face here + + + align:start position:0% +so that makes a nice flat face here +because the next piece that's coming is + + align:start position:0% +because the next piece that's coming is + + + align:start position:0% +because the next piece that's coming is +a 2X two square so what you're going to + + align:start position:0% +a 2X two square so what you're going to + + + align:start position:0% +a 2X two square so what you're going to +do is let it drop all the way and then + + align:start position:0% +do is let it drop all the way and then + + + align:start position:0% +do is let it drop all the way and then +at the very last second you slide it to + + align:start position:0% +at the very last second you slide it to + + + align:start position:0% +at the very last second you slide it to +the right okay uh and in general we're + + align:start position:0% +the right okay uh and in general we're + + + align:start position:0% +the right okay uh and in general we're +going to represent AI by this pattern + + align:start position:0% +going to represent AI by this pattern + + + align:start position:0% +going to represent AI by this pattern +Square left L Square to the power AI + + align:start position:0% +Square left L Square to the power AI + + + align:start position:0% +Square left L Square to the power AI +like we're going to repeat that AI times + + align:start position:0% +like we're going to repeat that AI times + + + align:start position:0% +like we're going to repeat that AI times +so here I've repeated it twice and then + + align:start position:0% +so here I've repeated it twice and then + + + align:start position:0% +so here I've repeated it twice and then +dot dot dot okay that is encoding AI in + + align:start position:0% +dot dot dot okay that is encoding AI in + + + align:start position:0% +dot dot dot okay that is encoding AI in +un or I don't know if there's something + + align:start position:0% +un or I don't know if there's something + + + align:start position:0% +un or I don't know if there's something +smaller than un where you use three + + align:start position:0% +smaller than un where you use three + + + align:start position:0% +smaller than un where you use three +objects to represent one one unit but uh + + align:start position:0% +objects to represent one one unit but uh + + + align:start position:0% +objects to represent one one unit but uh +there you go and then at the end the at + + align:start position:0% +there you go and then at the end the at + + + align:start position:0% +there you go and then at the end the at +the end of the AI we're going to sort of + + align:start position:0% +the end of the AI we're going to sort of + + + align:start position:0% +the end of the AI we're going to sort of +finish things off and reset to this + + align:start position:0% +finish things off and reset to this + + + align:start position:0% +finish things off and reset to this +original kind of configuration by saying + + align:start position:0% +original kind of configuration by saying + + + align:start position:0% +original kind of configuration by saying +Square uh and + + align:start position:0% +Square uh and + + + align:start position:0% +Square uh and +straight okay so the square Nestles in + + align:start position:0% +straight okay so the square Nestles in + + + align:start position:0% +straight okay so the square Nestles in +there we get a straight uh and if all + + align:start position:0% +there we get a straight uh and if all + + + align:start position:0% +there we get a straight uh and if all +goes according to plan what you've done + + align:start position:0% +goes according to plan what you've done + + + align:start position:0% +goes according to plan what you've done +is filled up basically AI units of this + + align:start position:0% +is filled up basically AI units of this + + + align:start position:0% +is filled up basically AI units of this +thing and maybe plus one but we know + + align:start position:0% +thing and maybe plus one but we know + + + align:start position:0% +thing and maybe plus one but we know +there's only three AIS going into each + + align:start position:0% +there's only three AIS going into each + + + align:start position:0% +there's only three AIS going into each +bucket so we can deal with a plus add of + + align:start position:0% +bucket so we can deal with a plus add of + + + align:start position:0% +bucket so we can deal with a plus add of +three that's no big deal um + + align:start position:0% +three that's no big deal um + + + align:start position:0% +three that's no big deal um +and that's good so now you have a choice + + align:start position:0% +and that's good so now you have a choice + + + align:start position:0% +and that's good so now you have a choice +you have this long sequence of pieces + + align:start position:0% +you have this long sequence of pieces + + + align:start position:0% +you have this long sequence of pieces +representing AI in general the P + + align:start position:0% +representing AI in general the P + + + align:start position:0% +representing AI in general the P +sequence is the P sequence for A1 P + + align:start position:0% +sequence is the P sequence for A1 P + + + align:start position:0% +sequence is the P sequence for A1 P +sequence for A2 P sequence for A3 the + + align:start position:0% +sequence for A2 P sequence for A3 the + + + align:start position:0% +sequence for A2 P sequence for A3 the +intent is you put all of these pieces + + align:start position:0% +intent is you put all of these pieces + + + align:start position:0% +intent is you put all of these pieces +into one column one of these buckets uh + + align:start position:0% +into one column one of these buckets uh + + + align:start position:0% +into one column one of these buckets uh +the claim is you can you can't again + + align:start position:0% +the claim is you can you can't again + + + align:start position:0% +the claim is you can you can't again +this is divisibility issue the big issue + + align:start position:0% +this is divisibility issue the big issue + + + align:start position:0% +this is divisibility issue the big issue +is can we divide AI into two parts put + + align:start position:0% +is can we divide AI into two parts put + + + align:start position:0% +is can we divide AI into two parts put +part of it in one bucket part of it in + + align:start position:0% +part of it in one bucket part of it in + + + align:start position:0% +part of it in one bucket part of it in +another bucket that would not give us a + + align:start position:0% +another bucket that would not give us a + + + align:start position:0% +another bucket that would not give us a +solution to three partition but the + + align:start position:0% +solution to three partition but the + + + align:start position:0% +solution to three partition but the +claim is you can't and the proof of this + + align:start position:0% +claim is you can't and the proof of this + + + align:start position:0% +claim is you can't and the proof of this +claim is not too hard for this proof it + + align:start position:0% +claim is not too hard for this proof it + + + align:start position:0% +claim is not too hard for this proof it +was much more tedious for the original + + align:start position:0% +was much more tedious for the original + + + align:start position:0% +was much more tedious for the original +proof uh but basically you try + + align:start position:0% +proof uh but basically you try + + + align:start position:0% +proof uh but basically you try +everything else and show that you doomed + + align:start position:0% +everything else and show that you doomed + + + align:start position:0% +everything else and show that you doomed +uh so every other possible move um so + + align:start position:0% +uh so every other possible move um so + + + align:start position:0% +uh so every other possible move um so +one type of bad move so we um when you + + align:start position:0% +one type of bad move so we um when you + + + align:start position:0% +one type of bad move so we um when you +when you do um this thing of putting in + + align:start position:0% +when you do um this thing of putting in + + + align:start position:0% +when you do um this thing of putting in +the rightward facing L remember there's + + align:start position:0% +the rightward facing L remember there's + + + align:start position:0% +the rightward facing L remember there's +only rightward facing L's there's only n + + align:start position:0% +only rightward facing L's there's only n + + + align:start position:0% +only rightward facing L's there's only n +of them one per + + align:start position:0% +of them one per + + + align:start position:0% +of them one per +AI so that's the only sort of nice piece + + align:start position:0% +AI so that's the only sort of nice piece + + + align:start position:0% +AI so that's the only sort of nice piece +we call this priming a bucket uh because + + align:start position:0% +we call this priming a bucket uh because + + + align:start position:0% +we call this priming a bucket uh because +now it has a nice flat bottom and so + + align:start position:0% +now it has a nice flat bottom and so + + + align:start position:0% +now it has a nice flat bottom and so +these pieces fit nicely especially the + + align:start position:0% +these pieces fit nicely especially the + + + align:start position:0% +these pieces fit nicely especially the +squares so one issue is what if you have + + align:start position:0% +squares so one issue is what if you have + + + align:start position:0% +squares so one issue is what if you have +an unprimed bucket it still has this + + align:start position:0% +an unprimed bucket it still has this + + + align:start position:0% +an unprimed bucket it still has this +stuff over on the left and you try to + + align:start position:0% +stuff over on the left and you try to + + + align:start position:0% +stuff over on the left and you try to +just insert into it cuz uh first A1 + + align:start position:0% +just insert into it cuz uh first A1 + + + align:start position:0% +just insert into it cuz uh first A1 +comes you prime one of the buckets + + align:start position:0% +comes you prime one of the buckets + + + align:start position:0% +comes you prime one of the buckets +what if you switch Midstream and try to + + align:start position:0% +what if you switch Midstream and try to + + + align:start position:0% +what if you switch Midstream and try to +move the rest into an unprimed bucket + + align:start position:0% +move the rest into an unprimed bucket + + + align:start position:0% +move the rest into an unprimed bucket +claim is you die you look at the squares + + align:start position:0% +claim is you die you look at the squares + + + align:start position:0% +claim is you die you look at the squares +you say well it could go here or here or + + align:start position:0% +you say well it could go here or here or + + + align:start position:0% +you say well it could go here or here or +or higher and they're all bad uh this + + align:start position:0% +or higher and they're all bad uh this + + + align:start position:0% +or higher and they're all bad uh this +one means you'll never fill this stuff + + align:start position:0% +one means you'll never fill this stuff + + + align:start position:0% +one means you'll never fill this stuff +uh so you're basically going to run out + + align:start position:0% +uh so you're basically going to run out + + + align:start position:0% +uh so you're basically going to run out +of area something's going to have to go + + align:start position:0% +of area something's going to have to go + + + align:start position:0% +of area something's going to have to go +into the sky uh if you put this here + + align:start position:0% +into the sky uh if you put this here + + + align:start position:0% +into the sky uh if you put this here +you'll never get anything here you put + + align:start position:0% +you'll never get anything here you put + + + align:start position:0% +you'll never get anything here you put +that there you'll never get anything + + align:start position:0% +that there you'll never get anything + + + align:start position:0% +that there you'll never get anything +here because squares won't fit anymore + + align:start position:0% +here because squares won't fit anymore + + + align:start position:0% +here because squares won't fit anymore +so on uh L's can't go pass through that + + align:start position:0% +so on uh L's can't go pass through that + + + align:start position:0% +so on uh L's can't go pass through that +thing okay similarly if you try to put a + + align:start position:0% +thing okay similarly if you try to put a + + + align:start position:0% +thing okay similarly if you try to put a +straightaway in something bad happens I + + align:start position:0% +straightaway in something bad happens I + + + align:start position:0% +straightaway in something bad happens I +don't quite remember what the bad thing + + align:start position:0% +don't quite remember what the bad thing + + + align:start position:0% +don't quite remember what the bad thing +is here uh but that + + align:start position:0% +is here uh but that + + + align:start position:0% +is here uh but that +looks right you can once you cover one + + align:start position:0% +looks right you can once you cover one + + + align:start position:0% +looks right you can once you cover one +you can't cover the other yeah it's not + + align:start position:0% +you can't cover the other yeah it's not + + + align:start position:0% +you can't cover the other yeah it's not +even obvious you can cover this one but + + align:start position:0% +even obvious you can cover this one but + + + align:start position:0% +even obvious you can cover this one but +I think with some clever rotation you + + align:start position:0% +I think with some clever rotation you + + + align:start position:0% +I think with some clever rotation you +can ah Tetris is a little weird in that + + align:start position:0% +can ah Tetris is a little weird in that + + + align:start position:0% +can ah Tetris is a little weird in that +respect um and then with the leftward + + align:start position:0% +respect um and then with the leftward + + + align:start position:0% +respect um and then with the leftward +facing L's you can try all the things + + align:start position:0% +facing L's you can try all the things + + + align:start position:0% +facing L's you can try all the things +and again you're + + align:start position:0% +and again you're + + + align:start position:0% +and again you're +toast okay so that's one type of bad + + align:start position:0% +toast okay so that's one type of bad + + + align:start position:0% +toast okay so that's one type of bad +thing where you switch mid stream from + + align:start position:0% +thing where you switch mid stream from + + + align:start position:0% +thing where you switch mid stream from +one of you you start putting an AI into + + align:start position:0% +one of you you start putting an AI into + + + align:start position:0% +one of you you start putting an AI into +a bucket and then you try to put it into + + align:start position:0% +a bucket and then you try to put it into + + + align:start position:0% +a bucket and then you try to put it into +a bucket that's currently unprimed um + + align:start position:0% +a bucket that's currently unprimed um + + + align:start position:0% +a bucket that's currently unprimed um +the so + + align:start position:0% +the so + + + align:start position:0% +the so +uh what's left is if you stick to one + + align:start position:0% +uh what's left is if you stick to one + + + align:start position:0% +uh what's left is if you stick to one +bucket uh do you have to play like we + + align:start position:0% +bucket uh do you have to play like we + + + align:start position:0% +bucket uh do you have to play like we +want to + + align:start position:0% +want to + + + align:start position:0% +want to +play and so in the sequence of pieces + + align:start position:0% +play and so in the sequence of pieces + + + align:start position:0% +play and so in the sequence of pieces +after you've when you haven't placed + + align:start position:0% +after you've when you haven't placed + + + align:start position:0% +after you've when you haven't placed +anything well maybe you try to prime it + + align:start position:0% +anything well maybe you try to prime it + + + align:start position:0% +anything well maybe you try to prime it +in a different way and then that opens + + align:start position:0% +in a different way and then that opens + + + align:start position:0% +in a different way and then that opens +up something else because then you'd + + align:start position:0% +up something else because then you'd + + + align:start position:0% +up something else because then you'd +have to go through that entire analysis + + align:start position:0% +have to go through that entire analysis + + + align:start position:0% +have to go through that entire analysis +from the last slide again uh for however + + align:start position:0% +from the last slide again uh for however + + + align:start position:0% +from the last slide again uh for however +the unprimed bucket might look but it + + align:start position:0% +the unprimed bucket might look but it + + + align:start position:0% +the unprimed bucket might look but it +turns out however you do it uh you're + + align:start position:0% +turns out however you do it uh you're + + + align:start position:0% +turns out however you do it uh you're +toast you've you've hidden some Square + + align:start position:0% +toast you've you've hidden some Square + + + align:start position:0% +toast you've you've hidden some Square +which you won't be able to uh open up + + align:start position:0% +which you won't be able to uh open up + + + align:start position:0% +which you won't be able to uh open up +unless you do it the right way and once + + align:start position:0% +unless you do it the right way and once + + + align:start position:0% +unless you do it the right way and once +you've done that piece you check that + + align:start position:0% +you've done that piece you check that + + + align:start position:0% +you've done that piece you check that +the next piece has only one place to go + + align:start position:0% +the next piece has only one place to go + + + align:start position:0% +the next piece has only one place to go +uh obviously if it's to the left then + + align:start position:0% +uh obviously if it's to the left then + + + align:start position:0% +uh obviously if it's to the left then +those are not good uh and then the next + + align:start position:0% +those are not good uh and then the next + + + align:start position:0% +those are not good uh and then the next +piece and so on so you check all these + + align:start position:0% +piece and so on so you check all these + + + align:start position:0% +piece and so on so you check all these +things and you conclude there's really + + align:start position:0% +things and you conclude there's really + + + align:start position:0% +things and you conclude there's really +only one way to play this sequence + + align:start position:0% +only one way to play this sequence + + + align:start position:0% +only one way to play this sequence +except for the flexibility of when a new + + align:start position:0% +except for the flexibility of when a new + + + align:start position:0% +except for the flexibility of when a new +AI stream comes which bucket do I put it + + align:start position:0% +AI stream comes which bucket do I put it + + + align:start position:0% +AI stream comes which bucket do I put it +in we're assuming here infinite + + align:start position:0% +in we're assuming here infinite + + + align:start position:0% +in we're assuming here infinite +dexterity so you can slide to the left + + align:start position:0% +dexterity so you can slide to the left + + + align:start position:0% +dexterity so you can slide to the left +and right pick the bucket you want and + + align:start position:0% +and right pick the bucket you want and + + + align:start position:0% +and right pick the bucket you want and +then let it + + align:start position:0% +then let it + + + align:start position:0% +then let it +fall questions yeah so you set up the + + align:start position:0% +fall questions yeah so you set up the + + + align:start position:0% +fall questions yeah so you set up the +you set up the infrastructure so that if + + align:start position:0% +you set up the infrastructure so that if + + + align:start position:0% +you set up the infrastructure so that if +you leave even one space unfilled and + + align:start position:0% +you leave even one space unfilled and + + + align:start position:0% +you leave even one space unfilled and +you're going to die before + + align:start position:0% +you're going to die before + + + align:start position:0% +you're going to die before +you yes um + + align:start position:0% +you yes um + + + align:start position:0% +you yes um +so the idea is that if you leave any + + align:start position:0% +so the idea is that if you leave any + + + align:start position:0% +so the idea is that if you leave any +Square out here you will be in trouble + + align:start position:0% +Square out here you will be in trouble + + + align:start position:0% +Square out here you will be in trouble +um and I there are probably many ways to + + align:start position:0% +um and I there are probably many ways to + + + align:start position:0% +um and I there are probably many ways to +do this and I forget exactly what we do + + align:start position:0% +do this and I forget exactly what we do + + + align:start position:0% +do this and I forget exactly what we do +in the paper I think the easy one would + + align:start position:0% +in the paper I think the easy one would + + + align:start position:0% +in the paper I think the easy one would +be that if you put any square up here + + align:start position:0% +be that if you put any square up here + + + align:start position:0% +be that if you put any square up here +you die so you're right at the limit of + + align:start position:0% +you die so you're right at the limit of + + + align:start position:0% +you die so you're right at the limit of +the game if anything doesn't go into a + + align:start position:0% +the game if anything doesn't go into a + + + align:start position:0% +the game if anything doesn't go into a +bucket you're in trouble and then it's + + align:start position:0% +bucket you're in trouble and then it's + + + align:start position:0% +bucket you're in trouble and then it's +just a volume argument so you've got all + + align:start position:0% +just a volume argument so you've got all + + + align:start position:0% +just a volume argument so you've got all +these pieces the total volume of them is + + align:start position:0% +these pieces the total volume of them is + + + align:start position:0% +these pieces the total volume of them is +exactly the sum of the bucket sizes so + + align:start position:0% +exactly the sum of the bucket sizes so + + + align:start position:0% +exactly the sum of the bucket sizes so +if you leave any blank blank space that + + align:start position:0% +if you leave any blank blank space that + + + align:start position:0% +if you leave any blank blank space that +means that the material that was there + + align:start position:0% +means that the material that was there + + + align:start position:0% +means that the material that was there +is going to somehow end up on the top + + align:start position:0% +is going to somehow end up on the top + + + align:start position:0% +is going to somehow end up on the top +row and then you're + + align:start position:0% +row and then you're + + + align:start position:0% +row and then you're +dead I don't remember if that's exactly + + align:start position:0% +dead I don't remember if that's exactly + + + align:start position:0% +dead I don't remember if that's exactly +what we did but that certainly seems to + + align:start position:0% +what we did but that certainly seems to + + + align:start position:0% +what we did but that certainly seems to +work + + align:start position:0% +work + + + align:start position:0% +work +Adam if you place something too high but + + align:start position:0% +Adam if you place something too high but + + + align:start position:0% +Adam if you place something too high but +at the same time finish a line do you + + align:start position:0% +at the same time finish a line do you + + + align:start position:0% +at the same time finish a line do you +die + + align:start position:0% +die + + + align:start position:0% +die +and um could we force our way through + + align:start position:0% +and um could we force our way through + + + align:start position:0% +and um could we force our way through +the lock + + align:start position:0% +the lock + + + align:start position:0% +the lock +early I believe in real Tetris if you + + align:start position:0% +early I believe in real Tetris if you + + + align:start position:0% +early I believe in real Tetris if you +clear a line that happens before you + + align:start position:0% +clear a line that happens before you + + + align:start position:0% +clear a line that happens before you +potentially die I don't think that's an + + align:start position:0% +potentially die I don't think that's an + + + align:start position:0% +potentially die I don't think that's an +issue here because you won't be able to + + align:start position:0% +issue here because you won't be able to + + + align:start position:0% +issue here because you won't be able to +clear anything until the T piece so I + + align:start position:0% +clear anything until the T piece so I + + + align:start position:0% +clear anything until the T piece so I +think you use the argument I said uh up + + align:start position:0% +think you use the argument I said uh up + + + align:start position:0% +think you use the argument I said uh up +to here if there are no other T's in the + + align:start position:0% +to here if there are no other T's in the + + + align:start position:0% +to here if there are no other T's in the +construction so uh any other piece you + + align:start position:0% +construction so uh any other piece you + + + align:start position:0% +construction so uh any other piece you +try to put in here I think will get you + + align:start position:0% +try to put in here I think will get you + + + align:start position:0% +try to put in here I think will get you +Above This row and then you die so so + + align:start position:0% +Above This row and then you die so so + + + align:start position:0% +Above This row and then you die so so +that's essentially unusable space until + + align:start position:0% +that's essentially unusable space until + + + align:start position:0% +that's essentially unusable space until +the T and then up until that point you + + align:start position:0% +the T and then up until that point you + + + align:start position:0% +the T and then up until that point you +have to exactly fill all this stuff yeah + + align:start position:0% +have to exactly fill all this stuff yeah + + + align:start position:0% +have to exactly fill all this stuff yeah +so if we ignore filling the lower stuff + + align:start position:0% +so if we ignore filling the lower stuff + + + align:start position:0% +so if we ignore filling the lower stuff +in the + + align:start position:0% +in the + + + align:start position:0% +in the +um uh main gadgets and just uh stick + + align:start position:0% +um uh main gadgets and just uh stick + + + align:start position:0% +um uh main gadgets and just uh stick +something up high and try to fill just + + align:start position:0% +something up high and try to fill just + + + align:start position:0% +something up high and try to fill just +the tops of each of them um so that with + + align:start position:0% +the tops of each of them um so that with + + + align:start position:0% +the tops of each of them um so that with +um an L or something we can clear one + + align:start position:0% +um an L or something we can clear one + + + align:start position:0% +um an L or something we can clear one +space of the oh I see you could try to + + align:start position:0% +space of the oh I see you could try to + + + align:start position:0% +space of the oh I see you could try to +put an L like that or like + + align:start position:0% +put an L like that or like + + + align:start position:0% +put an L like that or like +this + + align:start position:0% + + + + align:start position:0% + +uh yeah but if the row clears first all + + align:start position:0% +uh yeah but if the row clears first all + + + align:start position:0% +uh yeah but if the row clears first all +right then now I have to look up the + + align:start position:0% +right then now I have to look up the + + + align:start position:0% +right then now I have to look up the +rules I guess uh + + align:start position:0% +rules I guess uh + + + align:start position:0% +rules I guess uh +yeah I think it might be okay because + + align:start position:0% +yeah I think it might be okay because + + + align:start position:0% +yeah I think it might be okay because +then there's no way ever to fill the + + align:start position:0% +then there's no way ever to fill the + + + align:start position:0% +then there's no way ever to fill the +next part right let's talk about this + + align:start position:0% +next part right let's talk about this + + + align:start position:0% +next part right let's talk about this +offline I think there's something to + + align:start position:0% +offline I think there's something to + + + align:start position:0% +offline I think there's something to +check here which hopefully we did in the + + align:start position:0% +check here which hopefully we did in the + + + align:start position:0% +check here which hopefully we did in the +paper but I've by now forgotten yeah uh + + align:start position:0% +paper but I've by now forgotten yeah uh + + + align:start position:0% +paper but I've by now forgotten yeah uh +just for fun if you succeed at the end + + align:start position:0% +just for fun if you succeed at the end + + + align:start position:0% +just for fun if you succeed at the end +you get all of these right word facing + + align:start position:0% +you get all of these right word facing + + + align:start position:0% +you get all of these right word facing +L's then you get the T those lines clear + + align:start position:0% +L's then you get the T those lines clear + + + align:start position:0% +L's then you get the T those lines clear +and then you get all the eyes and it's + + align:start position:0% +and then you get all the eyes and it's + + + align:start position:0% +and then you get all the eyes and it's +so satisfying all those + + align:start position:0% + + + + align:start position:0% + +tetrises and then if you're um so Tetris + + align:start position:0% +tetrises and then if you're um so Tetris + + + align:start position:0% +tetrises and then if you're um so Tetris +is when you get four rows in one one + + align:start position:0% +is when you get four rows in one one + + + align:start position:0% +is when you get four rows in one one +move which can only be done with the + + align:start position:0% +move which can only be done with the + + + align:start position:0% +move which can only be done with the +Straits um so this is if you survive + + align:start position:0% +Straits um so this is if you survive + + + align:start position:0% +Straits um so this is if you survive +then you clear a whole bunch of uh + + align:start position:0% +then you clear a whole bunch of uh + + + align:start position:0% +then you clear a whole bunch of uh +columns but if you want to make it + + align:start position:0% +columns but if you want to make it + + + align:start position:0% +columns but if you want to make it +really embarrassing then you put this + + align:start position:0% +really embarrassing then you put this + + + align:start position:0% +really embarrassing then you put this +entire construction over a nice big wall + + align:start position:0% +entire construction over a nice big wall + + + align:start position:0% +entire construction over a nice big wall +or but big empty space and you put a + + align:start position:0% +or but big empty space and you put a + + + align:start position:0% +or but big empty space and you put a +whole bunch of pieces at the end uh like + + align:start position:0% +whole bunch of pieces at the end uh like + + + align:start position:0% +whole bunch of pieces at the end uh like +let's say L's all of the same + + align:start position:0% +let's say L's all of the same + + + align:start position:0% +let's say L's all of the same +orientation or something those are + + align:start position:0% +orientation or something those are + + + align:start position:0% +orientation or something those are +really easy to pack so if you want to + + align:start position:0% +really easy to pack so if you want to + + + align:start position:0% +really easy to pack so if you want to +maximize your score and you don't solve + + align:start position:0% +maximize your score and you don't solve + + + align:start position:0% +maximize your score and you don't solve +this thing then you're really going to + + align:start position:0% +this thing then you're really going to + + + align:start position:0% +this thing then you're really going to +lose bad because if you do solve this + + align:start position:0% +lose bad because if you do solve this + + + align:start position:0% +lose bad because if you do solve this +thing you're going to get tons of points + + align:start position:0% +thing you're going to get tons of points + + + align:start position:0% +thing you're going to get tons of points +by just playing in here + + align:start position:0% +by just playing in here + + + align:start position:0% +by just playing in here +forever so n the one minus Epsilon of + + align:start position:0% +forever so n the one minus Epsilon of + + + align:start position:0% +forever so n the one minus Epsilon of +the game is down here um and if you + + align:start position:0% +the game is down here um and if you + + + align:start position:0% +the game is down here um and if you +can't solve this thing at the top then + + align:start position:0% +can't solve this thing at the top then + + + align:start position:0% +can't solve this thing at the top then +you're getting a score of basically zero + + align:start position:0% +you're getting a score of basically zero + + + align:start position:0% +you're getting a score of basically zero +I mean you do place a few pieces but + + align:start position:0% +I mean you do place a few pieces but + + + align:start position:0% +I mean you do place a few pieces but +very small compared to the number of + + align:start position:0% +very small compared to the number of + + + align:start position:0% +very small compared to the number of +things down here you place like n the + + align:start position:0% +things down here you place like n the + + + align:start position:0% +things down here you place like n the +Epsilon pieces whereas if you do succeed + + align:start position:0% +Epsilon pieces whereas if you do succeed + + + align:start position:0% +Epsilon pieces whereas if you do succeed +then you uh get to place all n Pieces + + align:start position:0% + + + + align:start position:0% + +by uh this is just the initial + + align:start position:0% +by uh this is just the initial + + + align:start position:0% +by uh this is just the initial +configuration or which floating Square + + align:start position:0% +configuration or which floating Square + + + align:start position:0% +configuration or which floating Square +this thing sare oh this one that is + + align:start position:0% +this thing sare oh this one that is + + + align:start position:0% +this thing sare oh this one that is +possible to construct I + + align:start position:0% +possible to construct I + + + align:start position:0% +possible to construct I +believe uh this is a challenge there a + + align:start position:0% +believe uh this is a challenge there a + + + align:start position:0% +believe uh this is a challenge there a +whole industry of making cool initial + + align:start position:0% +whole industry of making cool initial + + + align:start position:0% +whole industry of making cool initial +patterns by playing a lot of things uh I + + align:start position:0% +patterns by playing a lot of things uh I + + + align:start position:0% +patterns by playing a lot of things uh I +agree that's not obvious but I think it + + align:start position:0% +agree that's not obvious but I think it + + + align:start position:0% +agree that's not obvious but I think it +can be built um um um and so what we get + + align:start position:0% +can be built um um um and so what we get + + + align:start position:0% +can be built um um um and so what we get +is to + + align:start position:0% +is to + + + align:start position:0% +is to +approximate uh + + align:start position:0% + + + + align:start position:0% + +Tetris let's say the number of pieces + + align:start position:0% +Tetris let's say the number of pieces + + + align:start position:0% +Tetris let's say the number of pieces +that you + + align:start position:0% + + + + align:start position:0% + +play uh less than an N to the 1us + + align:start position:0% +play uh less than an N to the 1us + + + align:start position:0% +play uh less than an N to the 1us +Epsilon + + align:start position:0% + + + + align:start position:0% + +factor is NP + + align:start position:0% +factor is NP + + + align:start position:0% +factor is NP +hard that's what we just showed or + + align:start position:0% +hard that's what we just showed or + + + align:start position:0% +hard that's what we just showed or +sketched + + align:start position:0% +sketched + + + align:start position:0% +sketched +um so this is an example of an + + align:start position:0% +um so this is an example of an + + + align:start position:0% +um so this is an example of an +inapproximability result this is a + + align:start position:0% +inapproximability result this is a + + + align:start position:0% +inapproximability result this is a +relatively easy one we just need to + + align:start position:0% +relatively easy one we just need to + + + align:start position:0% +relatively easy one we just need to +assume P does not equal NP and we get + + align:start position:0% +assume P does not equal NP and we get + + + align:start position:0% +assume P does not equal NP and we get +that you really can't approximate within + + align:start position:0% +that you really can't approximate within + + + align:start position:0% +that you really can't approximate within +any very good Factor sort of All or + + align:start position:0% +any very good Factor sort of All or + + + align:start position:0% +any very good Factor sort of All or +Nothing in this game um later in the + + align:start position:0% +Nothing in this game um later in the + + + align:start position:0% +Nothing in this game um later in the +class we'll see much more + + align:start position:0% +class we'll see much more + + + align:start position:0% +class we'll see much more +subtle in approximability + + align:start position:0% +subtle in approximability + + + align:start position:0% +subtle in approximability +results okay other questions hopefully + + align:start position:0% +results okay other questions hopefully + + + align:start position:0% +results okay other questions hopefully +no more + + align:start position:0% +no more + + + align:start position:0% +no more +issues um there are a lot of other open + + align:start position:0% +issues um there are a lot of other open + + + align:start position:0% +issues um there are a lot of other open +problems about Tetris uh you mentioned + + align:start position:0% +problems about Tetris uh you mentioned + + + align:start position:0% +problems about Tetris uh you mentioned +construction uh what if the board is + + align:start position:0% +construction uh what if the board is + + + align:start position:0% +construction uh what if the board is +empty seems like quite a challenging + + align:start position:0% +empty seems like quite a challenging + + + align:start position:0% +empty seems like quite a challenging +problem constant number of rows or + + align:start position:0% +problem constant number of rows or + + + align:start position:0% +problem constant number of rows or +columns here we assume that both + + align:start position:0% +columns here we assume that both + + + align:start position:0% +columns here we assume that both +dimensions are arbitrarily large it's + + align:start position:0% +dimensions are arbitrarily large it's + + + align:start position:0% +dimensions are arbitrarily large it's +part of the input uh but these seem very + + align:start position:0% +part of the input uh but these seem very + + + align:start position:0% +part of the input uh but these seem very +annoying uh interesting if you just have + + align:start position:0% +annoying uh interesting if you just have + + + align:start position:0% +annoying uh interesting if you just have +Straits I imagine Tetris is pretty easy + + align:start position:0% +Straits I imagine Tetris is pretty easy + + + align:start position:0% +Straits I imagine Tetris is pretty easy +uh so how many of the tetris pieces do + + align:start position:0% +uh so how many of the tetris pieces do + + + align:start position:0% +uh so how many of the tetris pieces do +you need to get a hardness proof or can + + align:start position:0% +you need to get a hardness proof or can + + + align:start position:0% +you need to get a hardness proof or can +are there certain small combinations + + align:start position:0% +are there certain small combinations + + + align:start position:0% +are there certain small combinations +that are easy uh we need this ability to + + align:start position:0% +that are easy uh we need this ability to + + + align:start position:0% +that are easy uh we need this ability to +slide at the last minute be nice if you + + align:start position:0% +slide at the last minute be nice if you + + + align:start position:0% +slide at the last minute be nice if you +could just always be hitting space bar + + align:start position:0% +could just always be hitting space bar + + + align:start position:0% +could just always be hitting space bar +and always drop your pieces from + + align:start position:0% +and always drop your pieces from + + + align:start position:0% +and always drop your pieces from +positive Infinity we don't know whether + + align:start position:0% +positive Infinity we don't know whether + + + align:start position:0% +positive Infinity we don't know whether +that problem is empty complete that + + align:start position:0% +that problem is empty complete that + + + align:start position:0% +that problem is empty complete that +might be the most tractable but it's uh + + align:start position:0% +might be the most tractable but it's uh + + + align:start position:0% +might be the most tractable but it's uh +proof would have to be a little + + align:start position:0% +proof would have to be a little + + + align:start position:0% +proof would have to be a little +different two-player Tetris online + + align:start position:0% +different two-player Tetris online + + + align:start position:0% +different two-player Tetris online +Tetris where you don't know the pieces + + align:start position:0% +Tetris where you don't know the pieces + + + align:start position:0% +Tetris where you don't know the pieces +in advance that's something we might get + + align:start position:0% +in advance that's something we might get + + + align:start position:0% +in advance that's something we might get +to later in the class but these are all + + align:start position:0% +to later in the class but these are all + + + align:start position:0% +to later in the class but these are all +open okay um so next topic is in graph + + align:start position:0% +open okay um so next topic is in graph + + + align:start position:0% +open okay um so next topic is in graph +Theory so suppose you have a graph + + align:start position:0% +Theory so suppose you have a graph + + + align:start position:0% +Theory so suppose you have a graph +vertices and edges you want to draw it + + align:start position:0% +vertices and edges you want to draw it + + + align:start position:0% +vertices and edges you want to draw it +in the plane uh no two vertices touching + + align:start position:0% +in the plane uh no two vertices touching + + + align:start position:0% +in the plane uh no two vertices touching +no vertex on an edge that's regular + + align:start position:0% +no vertex on an edge that's regular + + + align:start position:0% +no vertex on an edge that's regular +notional drawing + + align:start position:0% +notional drawing + + + align:start position:0% +notional drawing +but edges are allowed to cross if you're + + align:start position:0% +but edges are allowed to cross if you're + + + align:start position:0% +but edges are allowed to cross if you're +lucky graph is planer don't need any + + align:start position:0% +lucky graph is planer don't need any + + + align:start position:0% +lucky graph is planer don't need any +Crossings there's this notion of one + + align:start position:0% +Crossings there's this notion of one + + + align:start position:0% +Crossings there's this notion of one +planarity which goes back to the 80s + + align:start position:0% +planarity which goes back to the 80s + + + align:start position:0% +planarity which goes back to the 80s +where every Edge can cross at most one + + align:start position:0% +where every Edge can cross at most one + + + align:start position:0% +where every Edge can cross at most one +other Edge uh so this is an example of a + + align:start position:0% +other Edge uh so this is an example of a + + + align:start position:0% +other Edge uh so this is an example of a +one planer drawing some edges don't + + align:start position:0% +one planer drawing some edges don't + + + align:start position:0% +one planer drawing some edges don't +cross anything but but any Edge that has + + align:start position:0% +cross anything but but any Edge that has + + + align:start position:0% +cross anything but but any Edge that has +a Crossing only has + + align:start position:0% +a Crossing only has + + + align:start position:0% +a Crossing only has +one okay so uh this is n be + + align:start position:0% +one okay so uh this is n be + + + align:start position:0% +one okay so uh this is n be +complete uh no notion of strong here + + align:start position:0% +complete uh no notion of strong here + + + align:start position:0% +complete uh no notion of strong here +there's no numbers uh this is from 2007 + + align:start position:0% +there's no numbers uh this is from 2007 + + + align:start position:0% +there's no numbers uh this is from 2007 +and a reduction from three + + align:start position:0% +and a reduction from three + + + align:start position:0% +and a reduction from three +partition so uh here are two gadgets + + align:start position:0% +partition so uh here are two gadgets + + + align:start position:0% +partition so uh here are two gadgets +this is a double well okay we'll get to + + align:start position:0% +this is a double well okay we'll get to + + + align:start position:0% +this is a double well okay we'll get to +this one in a moment um here's a gadget + + align:start position:0% +this one in a moment um here's a gadget + + + align:start position:0% +this one in a moment um here's a gadget +which is the complete graph on six + + align:start position:0% +which is the complete graph on six + + + align:start position:0% +which is the complete graph on six +vertices k6 and uh the idea is that + + align:start position:0% +vertices k6 and uh the idea is that + + + align:start position:0% +vertices k6 and uh the idea is that +we're going to plug this in instead of a + + align:start position:0% +we're going to plug this in instead of a + + + align:start position:0% +we're going to plug this in instead of a +single Bold Edge so wherever there's a + + align:start position:0% +single Bold Edge so wherever there's a + + + align:start position:0% +single Bold Edge so wherever there's a +Bold Edge here what it really means is + + align:start position:0% +Bold Edge here what it really means is + + + align:start position:0% +Bold Edge here what it really means is +this gadget okay this is meant to be an + + align:start position:0% +this gadget okay this is meant to be an + + + align:start position:0% +this gadget okay this is meant to be an +uncrossable edge because usually an can + + align:start position:0% +uncrossable edge because usually an can + + + align:start position:0% +uncrossable edge because usually an can +take up to one Crossing what we're going + + align:start position:0% +take up to one Crossing what we're going + + + align:start position:0% +take up to one Crossing what we're going +to replace this edge with this thing + + align:start position:0% +to replace this edge with this thing + + + align:start position:0% +to replace this edge with this thing +which has a bunch of Crossings in it no + + align:start position:0% +which has a bunch of Crossings in it no + + + align:start position:0% +which has a bunch of Crossings in it no +matter how you draw it k6 is very + + align:start position:0% +matter how you draw it k6 is very + + + align:start position:0% +matter how you draw it k6 is very +symmetric so it's not too hard to argue + + align:start position:0% +symmetric so it's not too hard to argue + + + align:start position:0% +symmetric so it's not too hard to argue +about the different drawings but you see + + align:start position:0% +about the different drawings but you see + + + align:start position:0% +about the different drawings but you see +a Crossing there a Crossing there and a + + align:start position:0% +a Crossing there a Crossing there and a + + + align:start position:0% +a Crossing there a Crossing there and a +Crossing there and in general if you + + align:start position:0% +Crossing there and in general if you + + + align:start position:0% +Crossing there and in general if you +look at any path from this vertex to + + align:start position:0% +look at any path from this vertex to + + + align:start position:0% +look at any path from this vertex to +this vertex uh you visit a Crossing + + align:start position:0% +this vertex uh you visit a Crossing + + + align:start position:0% +this vertex uh you visit a Crossing +there's no way to get uh wait what about + + align:start position:0% +there's no way to get uh wait what about + + + align:start position:0% +there's no way to get uh wait what about +this + + align:start position:0% +this + + + align:start position:0% +this +one uh what do I mean if I if I attempt + + align:start position:0% +one uh what do I mean if I if I attempt + + + align:start position:0% +one uh what do I mean if I if I attempt +to draw an Edge through here I will hit + + align:start position:0% +to draw an Edge through here I will hit + + + align:start position:0% +to draw an Edge through here I will hit +an edge that has a Crossing on it that's + + align:start position:0% +an edge that has a Crossing on it that's + + + align:start position:0% +an edge that has a Crossing on it that's +what I want so in other words it's not + + align:start position:0% +what I want so in other words it's not + + + align:start position:0% +what I want so in other words it's not +possible to draw an edge across here and + + align:start position:0% +possible to draw an edge across here and + + + align:start position:0% +possible to draw an edge across here and +still be one planer so this effectively + + align:start position:0% +still be one planer so this effectively + + + align:start position:0% +still be one planer so this effectively +becomes an uncrossable edge this is + + align:start position:0% +becomes an uncrossable edge this is + + + align:start position:0% +becomes an uncrossable edge this is +notation this is super useful when you + + align:start position:0% +notation this is super useful when you + + + align:start position:0% +notation this is super useful when you +have a complicated construction if you + + align:start position:0% +have a complicated construction if you + + + align:start position:0% +have a complicated construction if you +do if you use the right notation it's + + align:start position:0% +do if you use the right notation it's + + + align:start position:0% +do if you use the right notation it's +not necessarily so complicated if we + + align:start position:0% +not necessarily so complicated if we + + + align:start position:0% +not necessarily so complicated if we +drew this everywhere in these pictures + + align:start position:0% +drew this everywhere in these pictures + + + align:start position:0% +drew this everywhere in these pictures +it would be really hard to see what's + + align:start position:0% +it would be really hard to see what's + + + align:start position:0% +it would be really hard to see what's +going on so we use this this visual idea + + align:start position:0% +going on so we use this this visual idea + + + align:start position:0% +going on so we use this this visual idea +that this is a symbol for that and then + + align:start position:0% +that this is a symbol for that and then + + + align:start position:0% +that this is a symbol for that and then +we can draw really simple pictures + + align:start position:0% +we can draw really simple pictures + + + align:start position:0% +we can draw really simple pictures +relatively simple pictures this is + + align:start position:0% +relatively simple pictures this is + + + align:start position:0% +relatively simple pictures this is +what's called a double wheel uh it's got + + align:start position:0% +what's called a double wheel uh it's got + + + align:start position:0% +what's called a double wheel uh it's got +a lot of spokes in the center and a + + align:start position:0% +a lot of spokes in the center and a + + + align:start position:0% +a lot of spokes in the center and a +cycle around there and then just another + + align:start position:0% +cycle around there and then just another + + + align:start position:0% +cycle around there and then just another +one around + + align:start position:0% +one around + + + align:start position:0% +one around +there and we're going to have two of + + align:start position:0% +there and we're going to have two of + + + align:start position:0% +there and we're going to have two of +them there's going to be exactly two of + + align:start position:0% +them there's going to be exactly two of + + + align:start position:0% +them there's going to be exactly two of +these gadgets one of size some of the + + align:start position:0% +these gadgets one of size some of the + + + align:start position:0% +these gadgets one of size some of the +A's the other of size + + align:start position:0% +A's the other of size + + + align:start position:0% +A's the other of size +n okay so in this picture we have six + + align:start position:0% +n okay so in this picture we have six + + + align:start position:0% +n okay so in this picture we have six +AIS and the sum of all of them is + + align:start position:0% +AIS and the sum of all of them is + + + align:start position:0% +AIS and the sum of all of them is +however many spokes are on that wheel + + align:start position:0% +however many spokes are on that wheel + + + align:start position:0% +however many spokes are on that wheel +okay um and then this is the actual + + align:start position:0% +okay um and then this is the actual + + + align:start position:0% +okay um and then this is the actual +construction so this is these are this + + align:start position:0% +construction so this is these are this + + + align:start position:0% +construction so this is these are this +is the AI + + align:start position:0% +is the AI + + + align:start position:0% +is the AI +Gadget um so let's look at this one this + + align:start position:0% +Gadget um so let's look at this one this + + + align:start position:0% +Gadget um so let's look at this one this +is uh when AI equals 3 going to have a + + align:start position:0% +is uh when AI equals 3 going to have a + + + align:start position:0% +is uh when AI equals 3 going to have a +vertex of degree 3 + 1 this path is a + + align:start position:0% +vertex of degree 3 + 1 this path is a + + + align:start position:0% +vertex of degree 3 + 1 this path is a +path of length two and it goes to this + + align:start position:0% +path of length two and it goes to this + + + align:start position:0% +path of length two and it goes to this +vertex the center of the smaller wheel + + align:start position:0% +vertex the center of the smaller wheel + + + align:start position:0% +vertex the center of the smaller wheel +of the N wheel um and then these the + + align:start position:0% +of the N wheel um and then these the + + + align:start position:0% +of the N wheel um and then these the +other three paths again are of length + + align:start position:0% +other three paths again are of length + + + align:start position:0% +other three paths again are of length +two and they connect to uh the center of + + align:start position:0% +two and they connect to uh the center of + + + align:start position:0% +two and they connect to uh the center of +of the sum of the + + align:start position:0% +of the sum of the + + + align:start position:0% +of the sum of the +AI uh Gadget so this is intended to + + align:start position:0% +AI uh Gadget so this is intended to + + + align:start position:0% +AI uh Gadget so this is intended to +represent the number three now there's a + + align:start position:0% +represent the number three now there's a + + + align:start position:0% +represent the number three now there's a +little bit more going on which is we + + align:start position:0% +little bit more going on which is we + + + align:start position:0% +little bit more going on which is we +added a Bold Edge here and a Bold Edge + + align:start position:0% +added a Bold Edge here and a Bold Edge + + + align:start position:0% +added a Bold Edge here and a Bold Edge +here in this case uh here's a case + + align:start position:0% +here in this case uh here's a case + + + align:start position:0% +here in this case uh here's a case +you're curious in this case n over3 is + + align:start position:0% +you're curious in this case n over3 is + + + align:start position:0% +you're curious in this case n over3 is +two so in general we have the sum of all + + align:start position:0% +two so in general we have the sum of all + + + align:start position:0% +two so in general we have the sum of all +we have all the AIS basically laid out + + align:start position:0% +we have all the AIS basically laid out + + + align:start position:0% +we have all the AIS basically laid out +here in some order and what we're trying + + align:start position:0% +here in some order and what we're trying + + + align:start position:0% +here in some order and what we're trying +to do is partition them into groups of + + align:start position:0% +to do is partition them into groups of + + + align:start position:0% +to do is partition them into groups of +size T so so here T is whatever this + + align:start position:0% +size T so so here T is whatever this + + + align:start position:0% +size T so so here T is whatever this +number is and so we add these + + align:start position:0% +number is and so we add these + + + align:start position:0% +number is and so we add these +uncrossable edges to say well an AI + + align:start position:0% +uncrossable edges to say well an AI + + + align:start position:0% +uncrossable edges to say well an AI +cannot go partly in this bin and partly + + align:start position:0% +cannot go partly in this bin and partly + + + align:start position:0% +cannot go partly in this bin and partly +in this bin it's got to choose which + + align:start position:0% +in this bin it's got to choose which + + + align:start position:0% +in this bin it's got to choose which +side of all of these bold lines it's on + + align:start position:0% +side of all of these bold lines it's on + + + align:start position:0% +side of all of these bold lines it's on +and so for each AI you choose in this + + align:start position:0% +and so for each AI you choose in this + + + align:start position:0% +and so for each AI you choose in this +case there's only two bins but in + + align:start position:0% +case there's only two bins but in + + + align:start position:0% +case there's only two bins but in +general there' be several bands each uh + + align:start position:0% +general there' be several bands each uh + + + align:start position:0% +general there' be several bands each uh +delineated by a Bold Edge from the end + + align:start position:0% +delineated by a Bold Edge from the end + + + align:start position:0% +delineated by a Bold Edge from the end +of the thing to uh the end of the thing + + align:start position:0% +of the thing to uh the end of the thing + + + align:start position:0% +of the thing to uh the end of the thing +over there um I mean this looks a little + + align:start position:0% +over there um I mean this looks a little + + + align:start position:0% +over there um I mean this looks a little +bit weird like okay how do the AI choose + + align:start position:0% +bit weird like okay how do the AI choose + + + align:start position:0% +bit weird like okay how do the AI choose +which side they're on here well they + + align:start position:0% +which side they're on here well they + + + align:start position:0% +which side they're on here well they +just choose whichever side they're on if + + align:start position:0% +just choose whichever side they're on if + + + align:start position:0% +just choose whichever side they're on if +they're on the b in the bottom chunk + + align:start position:0% +they're on the b in the bottom chunk + + + align:start position:0% +they're on the b in the bottom chunk +over here then they'll just connect to + + align:start position:0% +over here then they'll just connect to + + + align:start position:0% +over here then they'll just connect to +the bottom chunk over here so in the top + + align:start position:0% +the bottom chunk over here so in the top + + + align:start position:0% +the bottom chunk over here so in the top +chunk over here they'll connect to the + + align:start position:0% +chunk over here they'll connect to the + + + align:start position:0% +chunk over here they'll connect to the +corresponding chunk over + + align:start position:0% +corresponding chunk over + + + align:start position:0% +corresponding chunk over +there uh this is basically to force the + + align:start position:0% +there uh this is basically to force the + + + align:start position:0% +there uh this is basically to force the +AIS to start on the outside of this + + align:start position:0% +AIS to start on the outside of this + + + align:start position:0% +AIS to start on the outside of this +construction so you uh there's a lot of + + align:start position:0% +construction so you uh there's a lot of + + + align:start position:0% +construction so you uh there's a lot of +again there's a lot of cases here to + + align:start position:0% +again there's a lot of cases here to + + + align:start position:0% +again there's a lot of cases here to +worry about about other ways you might + + align:start position:0% +worry about about other ways you might + + + align:start position:0% +worry about about other ways you might +draw this maybe you take this entire + + align:start position:0% +draw this maybe you take this entire + + + align:start position:0% +draw this maybe you take this entire +picture and stuff it into this little + + align:start position:0% +picture and stuff it into this little + + + align:start position:0% +picture and stuff it into this little +triangle but they all end up with lots + + align:start position:0% +triangle but they all end up with lots + + + align:start position:0% +triangle but they all end up with lots +of Crossings on a single edge if you did + + align:start position:0% +of Crossings on a single edge if you did + + + align:start position:0% +of Crossings on a single edge if you did +that then you have to go you have to + + align:start position:0% +that then you have to go you have to + + + align:start position:0% +that then you have to go you have to +cross this Edge many times for + + align:start position:0% +cross this Edge many times for + + + align:start position:0% +cross this Edge many times for +example uh think we convinced ourselves + + align:start position:0% +example uh think we convinced ourselves + + + align:start position:0% +example uh think we convinced ourselves +that with a single wheel without this + + align:start position:0% +that with a single wheel without this + + + align:start position:0% +that with a single wheel without this +extra thing uh the + + align:start position:0% +extra thing uh the + + + align:start position:0% +extra thing uh the +construction I think we're not certain + + align:start position:0% +construction I think we're not certain + + + align:start position:0% +construction I think we're not certain +about whether construction works there's + + align:start position:0% +about whether construction works there's + + + align:start position:0% +about whether construction works there's +definitely more cases to consider so at + + align:start position:0% +definitely more cases to consider so at + + + align:start position:0% +definitely more cases to consider so at +the very least simplifies things by + + align:start position:0% +the very least simplifies things by + + + align:start position:0% +the very least simplifies things by +adding the second wheel it would also + + align:start position:0% +adding the second wheel it would also + + + align:start position:0% +adding the second wheel it would also +mean you'd have to have multiple edges + + align:start position:0% +mean you'd have to have multiple edges + + + align:start position:0% +mean you'd have to have multiple edges +here between the same two vertices so + + align:start position:0% +here between the same two vertices so + + + align:start position:0% +here between the same two vertices so +maybe that's why they did the the double + + align:start position:0% +maybe that's why they did the the double + + + align:start position:0% +maybe that's why they did the the double +wheel so that you have this padel length + + align:start position:0% +wheel so that you have this padel length + + + align:start position:0% +wheel so that you have this padel length +to connecting the same thing instead of + + align:start position:0% +to connecting the same thing instead of + + + align:start position:0% +to connecting the same thing instead of +the exact same Edge anyway uh so again + + align:start position:0% +the exact same Edge anyway uh so again + + + align:start position:0% +the exact same Edge anyway uh so again +you have to prove there's essentially + + align:start position:0% +you have to prove there's essentially + + + align:start position:0% +you have to prove there's essentially +only one planer embedding for the uh + + align:start position:0% +only one planer embedding for the uh + + + align:start position:0% +only one planer embedding for the uh +each of these wheels and for these + + align:start position:0% +each of these wheels and for these + + + align:start position:0% +each of these wheels and for these +things to connect them together and so + + align:start position:0% +things to connect them together and so + + + align:start position:0% +things to connect them together and so +the AIS have the freedom of which bucket + + align:start position:0% +the AIS have the freedom of which bucket + + + align:start position:0% +the AIS have the freedom of which bucket +they go into but um because each of + + align:start position:0% +they go into but um because each of + + + align:start position:0% +they go into but um because each of +these edges can only be crossed once + + align:start position:0% +these edges can only be crossed once + + + align:start position:0% +these edges can only be crossed once +each unit of each AI can only only one + + align:start position:0% +each unit of each AI can only only one + + + align:start position:0% +each unit of each AI can only only one +unit can occupy each of these cells so + + align:start position:0% +unit can occupy each of these cells so + + + align:start position:0% +unit can occupy each of these cells so +you get three + + align:start position:0% +you get three + + + align:start position:0% +you get three +partition cool yet another way to + + align:start position:0% +partition cool yet another way to + + + align:start position:0% +partition cool yet another way to +represent numbers in + + align:start position:0% +represent numbers in + + + align:start position:0% +represent numbers in +un question don't + + align:start position:0% + + + + align:start position:0% + +understand ah so okay so the these These + + align:start position:0% +understand ah so okay so the these These + + + align:start position:0% +understand ah so okay so the these These +are the AIS A1 is 2 A2 is three A3 is 3 + + align:start position:0% +are the AIS A1 is 2 A2 is three A3 is 3 + + + align:start position:0% +are the AIS A1 is 2 A2 is three A3 is 3 +A4 is three A5 is four and A6 is five + + align:start position:0% +A4 is three A5 is four and A6 is five + + + align:start position:0% +A4 is three A5 is four and A6 is five +and they are represented by this thing + + align:start position:0% +and they are represented by this thing + + + align:start position:0% +and they are represented by this thing +is a two this thing is a three this + + align:start position:0% +is a two this thing is a three this + + + align:start position:0% +is a two this thing is a three this +thing is a three this thing is a four + + align:start position:0% +thing is a three this thing is a four + + + align:start position:0% +thing is a three this thing is a four +and this is a five and that should be + + align:start position:0% +and this is a five and that should be + + + align:start position:0% +and this is a five and that should be +the same sequence I think I missed this + + align:start position:0% +the same sequence I think I missed this + + + align:start position:0% +the same sequence I think I missed this +three + + align:start position:0% +three + + + align:start position:0% +three +yep + + align:start position:0% +yep + + + align:start position:0% +yep +good okay that was one + + align:start position:0% +good okay that was one + + + align:start position:0% +good okay that was one +planarity oh boy four minutes which + + align:start position:0% +planarity oh boy four minutes which + + + align:start position:0% +planarity oh boy four minutes which +proofs to cover + + align:start position:0% +proofs to cover + + + align:start position:0% +proofs to cover +um I will wave my hands at this one uh + + align:start position:0% +um I will wave my hands at this one uh + + + align:start position:0% +um I will wave my hands at this one uh +this is a chain of blocks with with + + align:start position:0% +this is a chain of blocks with with + + + align:start position:0% +this is a chain of blocks with with +hinges on them uh and it has colors on + + align:start position:0% +hinges on them uh and it has colors on + + + align:start position:0% +hinges on them uh and it has colors on +it your goal is to form a particular + + align:start position:0% +it your goal is to form a particular + + + align:start position:0% +it your goal is to form a particular +pattern of colors um I find it + + align:start position:0% +pattern of colors um I find it + + + align:start position:0% +pattern of colors um I find it +interesting this is our hardness proof + + align:start position:0% +interesting this is our hardness proof + + + align:start position:0% +interesting this is our hardness proof +uh it's interesting in that it's a lot + + align:start position:0% +uh it's interesting in that it's a lot + + + align:start position:0% +uh it's interesting in that it's a lot +of the proofs you've seen it's all about + + align:start position:0% +of the proofs you've seen it's all about + + + align:start position:0% +of the proofs you've seen it's all about +making the AI being a straight line here + + align:start position:0% +making the AI being a straight line here + + + align:start position:0% +making the AI being a straight line here +that's not a big deal we've uh sort of + + align:start position:0% +that's not a big deal we've uh sort of + + + align:start position:0% +that's not a big deal we've uh sort of +drawn out uh this is again a kind of + + align:start position:0% +drawn out uh this is again a kind of + + + align:start position:0% +drawn out uh this is again a kind of +universal construction you can build in + + align:start position:0% +universal construction you can build in + + + align:start position:0% +universal construction you can build in +any polyomino with it it's all about the + + align:start position:0% +any polyomino with it it's all about the + + + align:start position:0% +any polyomino with it it's all about the +colors and so the idea is that the AIS + + align:start position:0% +colors and so the idea is that the AIS + + + align:start position:0% +colors and so the idea is that the AIS +are represented by how long of a blue + + align:start position:0% +are represented by how long of a blue + + + align:start position:0% +are represented by how long of a blue +segment you have here in the overall + + align:start position:0% +segment you have here in the overall + + + align:start position:0% +segment you have here in the overall +chain of pieces and uh these are the + + align:start position:0% +chain of pieces and uh these are the + + + align:start position:0% +chain of pieces and uh these are the +buckets and so you just come in at some + + align:start position:0% +buckets and so you just come in at some + + + align:start position:0% +buckets and so you just come in at some +point and fill in however big your AI is + + align:start position:0% +point and fill in however big your AI is + + + align:start position:0% +point and fill in however big your AI is +and then leave uh and there's just + + align:start position:0% +and then leave uh and there's just + + + align:start position:0% +and then leave uh and there's just +enough blue to cover all the blue so you + + align:start position:0% +enough blue to cover all the blue so you + + + align:start position:0% +enough blue to cover all the blue so you +better not waste it uh but all the other + + align:start position:0% +better not waste it uh but all the other + + + align:start position:0% +better not waste it uh but all the other +stuff you you have a lot of flexibility + + align:start position:0% +stuff you you have a lot of flexibility + + + align:start position:0% +stuff you you have a lot of flexibility +so it's all about just uh kind of + + align:start position:0% +so it's all about just uh kind of + + + align:start position:0% +so it's all about just uh kind of +filling these amorphous blobs that have + + align:start position:0% +filling these amorphous blobs that have + + + align:start position:0% +filling these amorphous blobs that have +exactly the right area to fill all these + + align:start position:0% +exactly the right area to fill all these + + + align:start position:0% +exactly the right area to fill all these +blue regions and there's three times + + align:start position:0% +blue regions and there's three times + + + align:start position:0% +blue regions and there's three times +you're allowed to visit and that gives + + align:start position:0% +you're allowed to visit and that gives + + + align:start position:0% +you're allowed to visit and that gives +you three partitions so I won't it's + + align:start position:0% +you three partitions so I won't it's + + + align:start position:0% +you three partitions so I won't it's +hard especially without a physical model + + align:start position:0% +hard especially without a physical model + + + align:start position:0% +hard especially without a physical model +to understand what the rules are of this + + align:start position:0% +to understand what the rules are of this + + + align:start position:0% +to understand what the rules are of this +game but gives you some idea of another + + align:start position:0% +game but gives you some idea of another + + + align:start position:0% +game but gives you some idea of another +way to represent three + + align:start position:0% +way to represent three + + + align:start position:0% +way to represent three +partition um next you may have seen this + + align:start position:0% +partition um next you may have seen this + + + align:start position:0% +partition um next you may have seen this +kind of object is called a carpers ruler + + align:start position:0% +kind of object is called a carpers ruler + + + align:start position:0% +kind of object is called a carpers ruler +or rule uh it's got hinges it's got + + align:start position:0% +or rule uh it's got hinges it's got + + + align:start position:0% +or rule uh it's got hinges it's got +rigid bars and usually when you're not + + align:start position:0% +rigid bars and usually when you're not + + + align:start position:0% +rigid bars and usually when you're not +using it one of I mean you can measure + + align:start position:0% +using it one of I mean you can measure + + + align:start position:0% +using it one of I mean you can measure +lengths that's that's the ruler part and + + align:start position:0% +lengths that's that's the ruler part and + + + align:start position:0% +lengths that's that's the ruler part and +when you're not using it it folds into + + align:start position:0% +when you're not using it it folds into + + + align:start position:0% +when you're not using it it folds into +this nice compact form it's great and + + align:start position:0% +this nice compact form it's great and + + + align:start position:0% +this nice compact form it's great and +everyone used these until the invention + + align:start position:0% +everyone used these until the invention + + + align:start position:0% +everyone used these until the invention +of the retractable one though they still + + align:start position:0% +of the retractable one though they still + + + align:start position:0% +of the retractable one though they still +use these a lot in Europe um so has unit + + align:start position:0% +use these a lot in Europe um so has unit + + + align:start position:0% +use these a lot in Europe um so has unit +length in this case but what if you have + + align:start position:0% +length in this case but what if you have + + + align:start position:0% +length in this case but what if you have +a really annoying uh Carpenters Rule and + + align:start position:0% +a really annoying uh Carpenters Rule and + + + align:start position:0% +a really annoying uh Carpenters Rule and +the lengths are not all + + align:start position:0% +the lengths are not all + + + align:start position:0% +the lengths are not all +equal uh and you have this nice box + + align:start position:0% +equal uh and you have this nice box + + + align:start position:0% +equal uh and you have this nice box +which is unit length or you know some + + align:start position:0% +which is unit length or you know some + + + align:start position:0% +which is unit length or you know some +length youd like to fit your rule ruler + + align:start position:0% +length youd like to fit your rule ruler + + + align:start position:0% +length youd like to fit your rule ruler +into that one-dimensional box Let's + + align:start position:0% +into that one-dimensional box Let's + + + align:start position:0% +into that one-dimensional box Let's +ignore the thickness here okay then this + + align:start position:0% +ignore the thickness here okay then this + + + align:start position:0% +ignore the thickness here okay then this +problem is hard uh it is weak NP hard + + align:start position:0% +problem is hard uh it is weak NP hard + + + align:start position:0% +problem is hard uh it is weak NP hard +you can solve it in pseudo poomi time so + + align:start position:0% +you can solve it in pseudo poomi time so + + + align:start position:0% +you can solve it in pseudo poomi time so +this is what this is like one of the + + align:start position:0% +this is what this is like one of the + + + align:start position:0% +this is what this is like one of the +very few problems we'll see of this type + + align:start position:0% +very few problems we'll see of this type + + + align:start position:0% +very few problems we'll see of this type +uh and this is the proof it's one of the + + align:start position:0% +uh and this is the proof it's one of the + + + align:start position:0% +uh and this is the proof it's one of the +simplest proofs uh from reduction from + + align:start position:0% +simplest proofs uh from reduction from + + + align:start position:0% +simplest proofs uh from reduction from +partition which is two partition which + + align:start position:0% +partition which is two partition which + + + align:start position:0% +partition which is two partition which +is divide your numbers into two groups + + align:start position:0% +is divide your numbers into two groups + + + align:start position:0% +is divide your numbers into two groups +and I apologize here in this book of + + align:start position:0% +and I apologize here in this book of + + + align:start position:0% +and I apologize here in this book of +ours we use x instead of a so those are + + align:start position:0% +ours we use x instead of a so those are + + + align:start position:0% +ours we use x instead of a so those are +AIS so you're given some AIS and the + + align:start position:0% +AIS so you're given some AIS and the + + + align:start position:0% +AIS so you're given some AIS and the +idea is well if I would like to + + align:start position:0% +idea is well if I would like to + + + align:start position:0% +idea is well if I would like to +partition the AIS into two groups of + + align:start position:0% +partition the AIS into two groups of + + + align:start position:0% +partition the AIS into two groups of +equal sums like so that's the same as + + align:start position:0% +equal sums like so that's the same as + + + align:start position:0% +equal sums like so that's the same as +saying well some of the AIS or the XIs + + align:start position:0% +saying well some of the AIS or the XIs + + + align:start position:0% +saying well some of the AIS or the XIs +are going to go left some of them are + + align:start position:0% +are going to go left some of them are + + + align:start position:0% +are going to go left some of them are +going to go right and whether I fold + + align:start position:0% +going to go right and whether I fold + + + align:start position:0% +going to go right and whether I fold +something where I could either leave it + + align:start position:0% +something where I could either leave it + + + align:start position:0% +something where I could either leave it +at 180 degre or I could fold it to 0 + + align:start position:0% +at 180 degre or I could fold it to 0 + + + align:start position:0% +at 180 degre or I could fold it to 0 +degrees that's sort of my binary choice + + align:start position:0% +degrees that's sort of my binary choice + + + align:start position:0% +degrees that's sort of my binary choice +if I'm going to go into a + + align:start position:0% +if I'm going to go into a + + + align:start position:0% +if I'm going to go into a +one-dimensional box if I fold it I + + align:start position:0% +one-dimensional box if I fold it I + + + align:start position:0% +one-dimensional box if I fold it I +change direction if I don't fold it I + + align:start position:0% +change direction if I don't fold it I + + + align:start position:0% +change direction if I don't fold it I +stay in the same direction but that what + + align:start position:0% +stay in the same direction but that what + + + align:start position:0% +stay in the same direction but that what +that really means is uh by some running + + align:start position:0% +that really means is uh by some running + + + align:start position:0% +that really means is uh by some running +sumti thing I can choose for each AI + + align:start position:0% +sumti thing I can choose for each AI + + + align:start position:0% +sumti thing I can choose for each AI +whether it goes left or right okay and + + align:start position:0% +whether it goes left or right okay and + + + align:start position:0% +whether it goes left or right okay and +then this is going to if this happens + + align:start position:0% +then this is going to if this happens + + + align:start position:0% +then this is going to if this happens +what it means is my starting point is + + align:start position:0% +what it means is my starting point is + + + align:start position:0% +what it means is my starting point is +equal to my ending point now it could be + + align:start position:0% +equal to my ending point now it could be + + + align:start position:0% +equal to my ending point now it could be +in between I go left and right and who + + align:start position:0% +in between I go left and right and who + + + align:start position:0% +in between I go left and right and who +knows what happens but the point is if + + align:start position:0% +knows what happens but the point is if + + + align:start position:0% +knows what happens but the point is if +they sum up to the lefts equal the + + align:start position:0% +they sum up to the lefts equal the + + + align:start position:0% +they sum up to the lefts equal the +rights then the starting point will be + + align:start position:0% +rights then the starting point will be + + + align:start position:0% +rights then the starting point will be +uh horizontally aligned with my ending + + align:start position:0% +uh horizontally aligned with my ending + + + align:start position:0% +uh horizontally aligned with my ending +point so that's not the problem the + + align:start position:0% +point so that's not the problem the + + + align:start position:0% +point so that's not the problem the +problem is to fit into a box of a given + + align:start position:0% +problem is to fit into a box of a given + + + align:start position:0% +problem is to fit into a box of a given +size so this says nothing about the box + + align:start position:0% +size so this says nothing about the box + + + align:start position:0% +size so this says nothing about the box +but if you do this very simple + + align:start position:0% +but if you do this very simple + + + align:start position:0% +but if you do this very simple +construction which is add a super long + + align:start position:0% +construction which is add a super long + + + align:start position:0% +construction which is add a super long +length and then add half of that at the + + align:start position:0% +length and then add half of that at the + + + align:start position:0% +length and then add half of that at the +beginning and then at the end you add + + align:start position:0% +beginning and then at the end you add + + + align:start position:0% +beginning and then at the end you add +half of the long length and then the + + align:start position:0% +half of the long length and then the + + + align:start position:0% +half of the long length and then the +super long length then and your goal is + + align:start position:0% +super long length then and your goal is + + + align:start position:0% +super long length then and your goal is +to fit it in a box of equal to the super + + align:start position:0% +to fit it in a box of equal to the super + + + align:start position:0% +to fit it in a box of equal to the super +long length that will be possible if and + + align:start position:0% +long length that will be possible if and + + + align:start position:0% +long length that will be possible if and +only if these are aligned if they're not + + align:start position:0% +only if these are aligned if they're not + + + align:start position:0% +only if these are aligned if they're not +aligned then if you go halfway left or + + align:start position:0% +aligned then if you go halfway left or + + + align:start position:0% +aligned then if you go halfway left or +right and then add the super long length + + align:start position:0% +right and then add the super long length + + + align:start position:0% +right and then add the super long length +if it's not aligned with this one then + + align:start position:0% +if it's not aligned with this one then + + + align:start position:0% +if it's not aligned with this one then +you'll be a little bit too big and you + + align:start position:0% +you'll be a little bit too big and you + + + align:start position:0% +you'll be a little bit too big and you +won't fit in the Box okay so that + + align:start position:0% +won't fit in the Box okay so that + + + align:start position:0% +won't fit in the Box okay so that +represents two + + align:start position:0% +represents two + + + align:start position:0% +represents two +partition cool 20 seconds one more proof + + align:start position:0% +partition cool 20 seconds one more proof + + + align:start position:0% +partition cool 20 seconds one more proof +um so here's another problem map folding + + align:start position:0% +um so here's another problem map folding + + + align:start position:0% +um so here's another problem map folding +uh you've probably done this before + + align:start position:0% +uh you've probably done this before + + + align:start position:0% +uh you've probably done this before +easiest way to refold a road map is + + align:start position:0% +easiest way to refold a road map is + + + align:start position:0% +easiest way to refold a road map is +differently uh but generally what we're + + align:start position:0% +differently uh but generally what we're + + + align:start position:0% +differently uh but generally what we're +interested in here is just very simple + + align:start position:0% +interested in here is just very simple + + + align:start position:0% +interested in here is just very simple +fold fold along one line then fold along + + align:start position:0% +fold fold along one line then fold along + + + align:start position:0% +fold fold along one line then fold along +another line and so on okay so uh this + + align:start position:0% +another line and so on okay so uh this + + + align:start position:0% +another line and so on okay so uh this +is NP hard if I give you a crease + + align:start position:0% +is NP hard if I give you a crease + + + align:start position:0% +is NP hard if I give you a crease +pattern this doesn't look much like a + + align:start position:0% +pattern this doesn't look much like a + + + align:start position:0% +pattern this doesn't look much like a +map but uh we can talk about that if I + + align:start position:0% +map but uh we can talk about that if I + + + align:start position:0% +map but uh we can talk about that if I +give you a a map a polygon and some + + align:start position:0% +give you a a map a polygon and some + + + align:start position:0% +give you a a map a polygon and some +creases on it and I want to fold all of + + align:start position:0% +creases on it and I want to fold all of + + + align:start position:0% +creases on it and I want to fold all of +these creases this is possible if and + + align:start position:0% +these creases this is possible if and + + + align:start position:0% +these creases this is possible if and +only if uh two partition is solvable + + align:start position:0% +only if uh two partition is solvable + + + align:start position:0% +only if uh two partition is solvable +notice these lengths ah here we used A's + + align:start position:0% +notice these lengths ah here we used A's + + + align:start position:0% +notice these lengths ah here we used A's +that's smart of us so these are the AIS + + align:start position:0% +that's smart of us so these are the AIS + + + align:start position:0% +that's smart of us so these are the AIS +down the distances between these creases + + align:start position:0% +down the distances between these creases + + + align:start position:0% +down the distances between these creases +consecutive creases and again the idea + + align:start position:0% +consecutive creases and again the idea + + + align:start position:0% +consecutive creases and again the idea +is well I could fold each one or not and + + align:start position:0% +is well I could fold each one or not and + + + align:start position:0% +is well I could fold each one or not and +just like the Carpenters rule I can fold + + align:start position:0% +just like the Carpenters rule I can fold + + + align:start position:0% +just like the Carpenters rule I can fold +or not and if I'm clever and I do it + + align:start position:0% +or not and if I'm clever and I do it + + + align:start position:0% +or not and if I'm clever and I do it +with the right choice then this end + + align:start position:0% +with the right choice then this end + + + align:start position:0% +with the right choice then this end +point will be uh vertically aligned has + + align:start position:0% +point will be uh vertically aligned has + + + align:start position:0% +point will be uh vertically aligned has +the same y-coordinate as this end + + align:start position:0% +the same y-coordinate as this end + + + align:start position:0% +the same y-coordinate as this end +point okay and if I do that then and + + align:start position:0% +point okay and if I do that then and + + + align:start position:0% +point okay and if I do that then and +again we've added half of the super long + + align:start position:0% +again we've added half of the super long + + + align:start position:0% +again we've added half of the super long +length and then the super long length + + align:start position:0% +length and then the super long length + + + align:start position:0% +length and then the super long length +here there's also half of the super long + + align:start position:0% +here there's also half of the super long + + + align:start position:0% +here there's also half of the super long +length and the super long length there + + align:start position:0% +length and the super long length there + + + align:start position:0% +length and the super long length there +and now I can fold these two folds so + + align:start position:0% +and now I can fold these two folds so + + + align:start position:0% +and now I can fold these two folds so +when I fold one it's going to go here + + align:start position:0% +when I fold one it's going to go here + + + align:start position:0% +when I fold one it's going to go here +and it won't hit anything if and only if + + align:start position:0% +and it won't hit anything if and only if + + + align:start position:0% +and it won't hit anything if and only if +I solve two + + align:start position:0% +I solve two + + + align:start position:0% +I solve two +partition right if again this this is + + align:start position:0% +partition right if again this this is + + + align:start position:0% +partition right if again this this is +the box that I'm trying to fit + + align:start position:0% +the box that I'm trying to fit + + + align:start position:0% +the box that I'm trying to fit +everything into and this is the thing + + align:start position:0% +everything into and this is the thing + + + align:start position:0% +everything into and this is the thing +that I'm trying to shift up and down to + + align:start position:0% +that I'm trying to shift up and down to + + + align:start position:0% +that I'm trying to shift up and down to +be perfectly aligned with that if I can + + align:start position:0% +be perfectly aligned with that if I can + + + align:start position:0% +be perfectly aligned with that if I can +perfectly align it then I fold + + align:start position:0% +perfectly align it then I fold + + + align:start position:0% +perfectly align it then I fold +this Miss then fold this and it's out + + align:start position:0% +this Miss then fold this and it's out + + + align:start position:0% +this Miss then fold this and it's out +again and then I can finish these other + + align:start position:0% +again and then I can finish these other + + + align:start position:0% +again and then I can finish these other +creases that I haven't folded yet okay + + align:start position:0% +creases that I haven't folded yet okay + + + align:start position:0% +creases that I haven't folded yet okay +so it's all about when do you execute + + align:start position:0% +so it's all about when do you execute + + + align:start position:0% +so it's all about when do you execute +these two folds and so I'm going to do + + align:start position:0% +these two folds and so I'm going to do + + + align:start position:0% +these two folds and so I'm going to do +some of the horizontal folds so that + + align:start position:0% +some of the horizontal folds so that + + + align:start position:0% +some of the horizontal folds so that +things fit nicely then I'll do the two + + align:start position:0% +things fit nicely then I'll do the two + + + align:start position:0% +things fit nicely then I'll do the two +vertical folds then I'll do the rest of + + align:start position:0% +vertical folds then I'll do the rest of + + + align:start position:0% +vertical folds then I'll do the rest of +the horizontal folds and that will work + + align:start position:0% +the horizontal folds and that will work + + + align:start position:0% +the horizontal folds and that will work +if and only if two partition is solvable + + align:start position:0% +if and only if two partition is solvable + + + align:start position:0% +if and only if two partition is solvable +now this may look like a weird map + + align:start position:0% +now this may look like a weird map + + + align:start position:0% +now this may look like a weird map +but it turns out if you have a regular + + align:start position:0% +but it turns out if you have a regular + + + align:start position:0% +but it turns out if you have a regular +rectangular + + align:start position:0% +rectangular + + + align:start position:0% +rectangular +map uh not maybe a regular one and you + + align:start position:0% +map uh not maybe a regular one and you + + + align:start position:0% +map uh not maybe a regular one and you +have uh some diagonal folds + + align:start position:0% +have uh some diagonal folds + + + align:start position:0% +have uh some diagonal folds +45° then that will basically force you + + align:start position:0% +45° then that will basically force you + + + align:start position:0% +45° then that will basically force you +to fold oops + + align:start position:0% +to fold oops + + + align:start position:0% +to fold oops +uh didn't Mo myself enough the + + align:start position:0% +uh didn't Mo myself enough the + + + align:start position:0% +uh didn't Mo myself enough the +room that will force you to fold + + align:start position:0% +room that will force you to fold + + + align:start position:0% +room that will force you to fold +something + + align:start position:0% +something + + + align:start position:0% +something +like this + + align:start position:0% + + + + align:start position:0% + +oops it + + align:start position:0% + + + + align:start position:0% + +again uh one two and then + + align:start position:0% +again uh one two and then + + + align:start position:0% +again uh one two and then +here okay so you can put in diagonal + + align:start position:0% +here okay so you can put in diagonal + + + align:start position:0% +here okay so you can put in diagonal +folds to force you to fold into this + + align:start position:0% +folds to force you to fold into this + + + align:start position:0% +folds to force you to fold into this +initial structure and then add folds on + + align:start position:0% +initial structure and then add folds on + + + align:start position:0% +initial structure and then add folds on +top of that so it's like composing two + + align:start position:0% +top of that so it's like composing two + + + align:start position:0% +top of that so it's like composing two +gadgets then you add horizontal and + + align:start position:0% +gadgets then you add horizontal and + + + align:start position:0% +gadgets then you add horizontal and +vertical folds just like that picture + + align:start position:0% +vertical folds just like that picture + + + align:start position:0% +vertical folds just like that picture +and then you'll have a rectangular map + + align:start position:0% +and then you'll have a rectangular map + + + align:start position:0% +and then you'll have a rectangular map +with horizontal vertical and diagonal + + align:start position:0% +with horizontal vertical and diagonal + + + align:start position:0% +with horizontal vertical and diagonal +creases that you can fold all the + + align:start position:0% +creases that you can fold all the + + + align:start position:0% +creases that you can fold all the +increases by simple folds if and only if + + align:start position:0% +increases by simple folds if and only if + + + align:start position:0% +increases by simple folds if and only if +to partition is solvable open problem is + + align:start position:0% +to partition is solvable open problem is + + + align:start position:0% +to partition is solvable open problem is +this strongly NP hard we don't know is + + align:start position:0% +this strongly NP hard we don't know is + + + align:start position:0% +this strongly NP hard we don't know is +there pseud polinomial algorithm + + align:start position:0% +there pseud polinomial algorithm + + + align:start position:0% +there pseud polinomial algorithm +obviously we don't know um it's quite + + align:start position:0% +obviously we don't know um it's quite + + + align:start position:0% +obviously we don't know um it's quite +tantalizing uh but this is basically why + + align:start position:0% +tantalizing uh but this is basically why + + + align:start position:0% +tantalizing uh but this is basically why +Maps don't have diagonal + + align:start position:0% + + + + align:start position:0% + +faults and that's it for today \ No newline at end of file diff --git a/VuG2JNcRXYg.txt b/VuG2JNcRXYg.txt new file mode 100644 index 0000000000000000000000000000000000000000..eda6a8d5e990c48f263da50b600a7bd8a027504f --- /dev/null +++ b/VuG2JNcRXYg.txt @@ -0,0 +1,4651 @@ +align:start position:0% + +so we're going to talk about State + + align:start position:0% +so we're going to talk about State + + + align:start position:0% +so we're going to talk about State +machines which is a topic that you're + + align:start position:0% +machines which is a topic that you're + + + align:start position:0% +machines which is a topic that you're +going to see on many further courses + + align:start position:0% +going to see on many further courses + + + align:start position:0% +going to see on many further courses +because State machines model + + align:start position:0% +because State machines model + + + align:start position:0% +because State machines model +step-by-step + + align:start position:0% +step-by-step + + + align:start position:0% +step-by-step +processes uh and of course if you think + + align:start position:0% +processes uh and of course if you think + + + align:start position:0% +processes uh and of course if you think +about a computation the normal way you + + align:start position:0% +about a computation the normal way you + + + align:start position:0% +about a computation the normal way you +think about it is that it's doing + + align:start position:0% +think about it is that it's doing + + + align:start position:0% +think about it is that it's doing +instructions step by step one after + + align:start position:0% +instructions step by step one after + + + align:start position:0% +instructions step by step one after +another until it finally reaches + + align:start position:0% +another until it finally reaches + + + align:start position:0% +another until it finally reaches +termination uh likewise uh various + + align:start position:0% +termination uh likewise uh various + + + align:start position:0% +termination uh likewise uh various +digital circuits move through stages or + + align:start position:0% +digital circuits move through stages or + + + align:start position:0% +digital circuits move through stages or +States until they produce a final answer + + align:start position:0% +States until they produce a final answer + + + align:start position:0% +States until they produce a final answer +uh so State machines come up in at least + + align:start position:0% +uh so State machines come up in at least + + + align:start position:0% +uh so State machines come up in at least +those circumstances and many others now + + align:start position:0% +those circumstances and many others now + + + align:start position:0% +those circumstances and many others now +the general model of State machine + + align:start position:0% +the general model of State machine + + + align:start position:0% +the general model of State machine +involves the idea that you can give it + + align:start position:0% +involves the idea that you can give it + + + align:start position:0% +involves the idea that you can give it +input and it responds to them but we + + align:start position:0% +input and it responds to them but we + + + align:start position:0% +input and it responds to them but we +don't really need that for our purposes + + align:start position:0% +don't really need that for our purposes + + + align:start position:0% +don't really need that for our purposes +um so let's look at our example of a + + align:start position:0% +um so let's look at our example of a + + + align:start position:0% +um so let's look at our example of a +state machine here's Maybe here's a + + align:start position:0% +state machine here's Maybe here's a + + + align:start position:0% +state machine here's Maybe here's a +particular simple one uh this is a the a + + align:start position:0% +particular simple one uh this is a the a + + + align:start position:0% +particular simple one uh this is a the a +description of a state machine that + + align:start position:0% +description of a state machine that + + + align:start position:0% +description of a state machine that +counts to 99 so the circles are + + align:start position:0% +counts to 99 so the circles are + + + align:start position:0% +counts to 99 so the circles are +indicating what its states are we've + + align:start position:0% +indicating what its states are we've + + + align:start position:0% +indicating what its states are we've +named them uh from zero through 99 and + + align:start position:0% +named them uh from zero through 99 and + + + align:start position:0% +named them uh from zero through 99 and +then there's a final State called + + align:start position:0% +then there's a final State called + + + align:start position:0% +then there's a final State called +overflow and that funny uh Arc is an + + align:start position:0% +overflow and that funny uh Arc is an + + + align:start position:0% +overflow and that funny uh Arc is an +indication that if you're about to if + + align:start position:0% +indication that if you're about to if + + + align:start position:0% +indication that if you're about to if +you're in overflow mode and you make + + align:start position:0% +you're in overflow mode and you make + + + align:start position:0% +you're in overflow mode and you make +another step by following the arc you + + align:start position:0% +another step by following the arc you + + + align:start position:0% +another step by following the arc you +get back to overflow mode but if you're + + align:start position:0% +get back to overflow mode but if you're + + + align:start position:0% +get back to overflow mode but if you're +in zero you can make a step to one and + + align:start position:0% +in zero you can make a step to one and + + + align:start position:0% +in zero you can make a step to one and +if you're in one you can make a step to + + align:start position:0% +if you're in one you can make a step to + + + align:start position:0% +if you're in one you can make a step to +two and so on so starting off um at the + + align:start position:0% +two and so on so starting off um at the + + + align:start position:0% +two and so on so starting off um at the +start State um which is generally + + align:start position:0% +start State um which is generally + + + align:start position:0% +start State um which is generally +indicated by uh that double Mark so to + + align:start position:0% +indicated by uh that double Mark so to + + + align:start position:0% +indicated by uh that double Mark so to +indicate where to start then the + + align:start position:0% +indicate where to start then the + + + align:start position:0% +indicate where to start then the +description of this machine consistent + + align:start position:0% +description of this machine consistent + + + align:start position:0% +description of this machine consistent +in in complete description is a set of + + align:start position:0% +in in complete description is a set of + + + align:start position:0% +in in complete description is a set of +states which are pictured as 0 through + + align:start position:0% +states which are pictured as 0 through + + + align:start position:0% +states which are pictured as 0 through +99 plus overflow a set of transitions + + align:start position:0% +99 plus overflow a set of transitions + + + align:start position:0% +99 plus overflow a set of transitions +which are indicated by the arrows which + + align:start position:0% +which are indicated by the arrows which + + + align:start position:0% +which are indicated by the arrows which +is how one state can move to another + + align:start position:0% +is how one state can move to another + + + align:start position:0% +is how one state can move to another +state uh and the transitions can be + + align:start position:0% +state uh and the transitions can be + + + align:start position:0% +state uh and the transitions can be +summarized by saying that they're of the + + align:start position:0% +summarized by saying that they're of the + + + align:start position:0% +summarized by saying that they're of the +form I to I + 1 for I between 0 and 99 + + align:start position:0% +form I to I + 1 for I between 0 and 99 + + + align:start position:0% +form I to I + 1 for I between 0 and 99 +and then there's a 90 9 transition to + + align:start position:0% +and then there's a 90 9 transition to + + + align:start position:0% +and then there's a 90 9 transition to +overflow and once you're in overflow you + + align:start position:0% +overflow and once you're in overflow you + + + align:start position:0% +overflow and once you're in overflow you +stay in overflow so the picture at the + + align:start position:0% +stay in overflow so the picture at the + + + align:start position:0% +stay in overflow so the picture at the +top is saying exactly the same thing as + + align:start position:0% +top is saying exactly the same thing as + + + align:start position:0% +top is saying exactly the same thing as +we've said here uh in mathematical + + align:start position:0% +we've said here uh in mathematical + + + align:start position:0% +we've said here uh in mathematical +notation explicitly describing what the + + align:start position:0% +notation explicitly describing what the + + + align:start position:0% +notation explicitly describing what the +transitions are so so this is a machine + + align:start position:0% +transitions are so so this is a machine + + + align:start position:0% +transitions are so so this is a machine +that if if you really built something + + align:start position:0% +that if if you really built something + + + align:start position:0% +that if if you really built something +that behaved this way it wouldn't be + + align:start position:0% +that behaved this way it wouldn't be + + + align:start position:0% +that behaved this way it wouldn't be +much use because once it's overflowed + + align:start position:0% +much use because once it's overflowed + + + align:start position:0% +much use because once it's overflowed +it's dead because it stays there uh real + + align:start position:0% +it's dead because it stays there uh real + + + align:start position:0% +it's dead because it stays there uh real +machine to be useful would have a reset + + align:start position:0% +machine to be useful would have a reset + + + align:start position:0% +machine to be useful would have a reset +transition which took overflow back to + + align:start position:0% +transition which took overflow back to + + + align:start position:0% +transition which took overflow back to +zero but uh this illustrates uh the + + align:start position:0% +zero but uh this illustrates uh the + + + align:start position:0% +zero but uh this illustrates uh the +basic + + align:start position:0% +basic + + + align:start position:0% +basic +idea so let's look at a fun example from + + align:start position:0% +idea so let's look at a fun example from + + + align:start position:0% +idea so let's look at a fun example from +a Die Hard movie I forgotten which one + + align:start position:0% +a Die Hard movie I forgotten which one + + + align:start position:0% +a Die Hard movie I forgotten which one +it was um but there was one with Bruce + + align:start position:0% +it was um but there was one with Bruce + + + align:start position:0% +it was um but there was one with Bruce +Willis and Samuel Jackson playing a + + align:start position:0% +Willis and Samuel Jackson playing a + + + align:start position:0% +Willis and Samuel Jackson playing a +detective and a a friend that he meets + + align:start position:0% +detective and a a friend that he meets + + + align:start position:0% +detective and a a friend that he meets +who helps him deal with a Madman as is + + align:start position:0% +who helps him deal with a Madman as is + + + align:start position:0% +who helps him deal with a Madman as is +the case in all these movies this time + + align:start position:0% +the case in all these movies this time + + + align:start position:0% +the case in all these movies this time +the madman's name is Simon and what + + align:start position:0% +the madman's name is Simon and what + + + align:start position:0% +the madman's name is Simon and what +Simon says to them as they stand behind + + align:start position:0% +Simon says to them as they stand behind + + + align:start position:0% +Simon says to them as they stand behind +the fountain in the park shown on the + + align:start position:0% +the fountain in the park shown on the + + + align:start position:0% +the fountain in the park shown on the +previous slide is that on the fountain + + align:start position:0% +previous slide is that on the fountain + + + align:start position:0% +previous slide is that on the fountain +there should be two jugs do you see them + + align:start position:0% +there should be two jugs do you see them + + + align:start position:0% +there should be two jugs do you see them +a 5 gallon and a three gallon fill one + + align:start position:0% +a 5 gallon and a three gallon fill one + + + align:start position:0% +a 5 gallon and a three gallon fill one +of these jugs with exactly four gallons + + align:start position:0% +of these jugs with exactly four gallons + + + align:start position:0% +of these jugs with exactly four gallons +of water and place it on the scale and + + align:start position:0% +of water and place it on the scale and + + + align:start position:0% +of water and place it on the scale and +the timer will stop the timer and the + + align:start position:0% +the timer will stop the timer and the + + + align:start position:0% +the timer will stop the timer and the +scale are not shown in that picture but + + align:start position:0% +scale are not shown in that picture but + + + align:start position:0% +scale are not shown in that picture but +there's a scale and a timer nearby you + + align:start position:0% +there's a scale and a timer nearby you + + + align:start position:0% +there's a scale and a timer nearby you +must be precise 1 oun more or less will + + align:start position:0% +must be precise 1 oun more or less will + + + align:start position:0% +must be precise 1 oun more or less will +result in detonation if you're still + + align:start position:0% +result in detonation if you're still + + + align:start position:0% +result in detonation if you're still +alive in five minutes we'll + + align:start position:0% +alive in five minutes we'll + + + align:start position:0% +alive in five minutes we'll +speak okay so let's think about + + align:start position:0% +speak okay so let's think about + + + align:start position:0% +speak okay so let's think about +formalizing this as a state machine to + + align:start position:0% +formalizing this as a state machine to + + + align:start position:0% +formalizing this as a state machine to +see what's going on and so the but first + + align:start position:0% +see what's going on and so the but first + + + align:start position:0% +see what's going on and so the but first +of all to understand the uh the the the + + align:start position:0% +of all to understand the uh the the the + + + align:start position:0% +of all to understand the uh the the the +specification informally what there is + + align:start position:0% +specification informally what there is + + + align:start position:0% +specification informally what there is +is a three gallon jug and a five gallon + + align:start position:0% +is a three gallon jug and a five gallon + + + align:start position:0% +is a three gallon jug and a five gallon +jug uh that it's capable of holding + + align:start position:0% +jug uh that it's capable of holding + + + align:start position:0% +jug uh that it's capable of holding +water and an unlimited supply of water + + align:start position:0% +water and an unlimited supply of water + + + align:start position:0% +water and an unlimited supply of water +that you can get from The + + align:start position:0% +that you can get from The + + + align:start position:0% +that you can get from The +Fountain and the basic moves that you + + align:start position:0% +Fountain and the basic moves that you + + + align:start position:0% +Fountain and the basic moves that you +can make so with this setup the kind of + + align:start position:0% +can make so with this setup the kind of + + + align:start position:0% +can make so with this setup the kind of +moves that you can make would be say you + + align:start position:0% +moves that you can make would be say you + + + align:start position:0% +moves that you can make would be say you +fill up the three gallon jug with water + + align:start position:0% +fill up the three gallon jug with water + + + align:start position:0% +fill up the three gallon jug with water +uh and then you could pour the three + + align:start position:0% +uh and then you could pour the three + + + align:start position:0% +uh and then you could pour the three +gallon jug into the five gallon jug so + + align:start position:0% +gallon jug into the five gallon jug so + + + align:start position:0% +gallon jug into the five gallon jug so +the three gallon jug was empty and the 5 + + align:start position:0% +the three gallon jug was empty and the 5 + + + align:start position:0% +the three gallon jug was empty and the 5 +gallon jug you knew had exactly three + + align:start position:0% +gallon jug you knew had exactly three + + + align:start position:0% +gallon jug you knew had exactly three +gallons in it um uh and then you can do + + align:start position:0% +gallons in it um uh and then you can do + + + align:start position:0% +gallons in it um uh and then you can do +other things like empty a jug and fill a + + align:start position:0% +other things like empty a jug and fill a + + + align:start position:0% +other things like empty a jug and fill a +jug um and empty them into each other so + + align:start position:0% +jug um and empty them into each other so + + + align:start position:0% +jug um and empty them into each other so +let's model this as a state machine and + + align:start position:0% +let's model this as a state machine and + + + align:start position:0% +let's model this as a state machine and +the first decision we need to make is + + align:start position:0% +the first decision we need to make is + + + align:start position:0% +the first decision we need to make is +what's the state going to be well the + + align:start position:0% +what's the state going to be well the + + + align:start position:0% +what's the state going to be well the +state the obvious model for the state is + + align:start position:0% +state the obvious model for the state is + + + align:start position:0% +state the obvious model for the state is +the amount of water in each of the jugs + + align:start position:0% +the amount of water in each of the jugs + + + align:start position:0% +the amount of water in each of the jugs +so B is the amount of in the big jug and + + align:start position:0% +so B is the amount of in the big jug and + + + align:start position:0% +so B is the amount of in the big jug and +L is the amount in the little jug and + + align:start position:0% +L is the amount in the little jug and + + + align:start position:0% +L is the amount in the little jug and +what we know about B and L is that + + align:start position:0% +what we know about B and L is that + + + align:start position:0% +what we know about B and L is that +they're going to be some amount between + + align:start position:0% +they're going to be some amount between + + + align:start position:0% +they're going to be some amount between +zero and five for B and zero and three + + align:start position:0% +zero and five for B and zero and three + + + align:start position:0% +zero and five for B and zero and three +for L where we're going to quickly + + align:start position:0% +for L where we're going to quickly + + + align:start position:0% +for L where we're going to quickly +realize that we need them to be integers + + align:start position:0% +realize that we need them to be integers + + + align:start position:0% +realize that we need them to be integers +but off hand we can allow them to be + + align:start position:0% +but off hand we can allow them to be + + + align:start position:0% +but off hand we can allow them to be +real numbers because uh after all you + + align:start position:0% +real numbers because uh after all you + + + align:start position:0% +real numbers because uh after all you +could just pour some arbitrary amount of + + align:start position:0% +could just pour some arbitrary amount of + + + align:start position:0% +could just pour some arbitrary amount of +water into the big jug any amount that + + align:start position:0% +water into the big jug any amount that + + + align:start position:0% +water into the big jug any amount that +it'll hold between zero and five + + align:start position:0% +it'll hold between zero and five + + + align:start position:0% +it'll hold between zero and five +although that'll be dangerous because as + + align:start position:0% +although that'll be dangerous because as + + + align:start position:0% +although that'll be dangerous because as +soon as you do that uh you're going to + + align:start position:0% +soon as you do that uh you're going to + + + align:start position:0% +soon as you do that uh you're going to +lose track of exactly how much is in + + align:start position:0% +lose track of exactly how much is in + + + align:start position:0% +lose track of exactly how much is in +there and you won't know when you have + + align:start position:0% +there and you won't know when you have + + + align:start position:0% +there and you won't know when you have +four gallons or not so let's formalize + + align:start position:0% +four gallons or not so let's formalize + + + align:start position:0% +four gallons or not so let's formalize +the possible moves that we can have so + + align:start position:0% +the possible moves that we can have so + + + align:start position:0% +the possible moves that we can have so +first of all the start state is 0 + + align:start position:0% +first of all the start state is 0 + + + align:start position:0% +first of all the start state is 0 +because we start with both jugs empty + + align:start position:0% +because we start with both jugs empty + + + align:start position:0% +because we start with both jugs empty +and then what are the possible + + align:start position:0% +and then what are the possible + + + align:start position:0% +and then what are the possible +transitions of how B&L moves well let's + + align:start position:0% +transitions of how B&L moves well let's + + + align:start position:0% +transitions of how B&L moves well let's +see the the fill the little jug move + + align:start position:0% +see the the fill the little jug move + + + align:start position:0% +see the the fill the little jug move +amounts to saying that if you have an + + align:start position:0% +amounts to saying that if you have an + + + align:start position:0% +amounts to saying that if you have an +amount a b in big and L in little then + + align:start position:0% +amount a b in big and L in little then + + + align:start position:0% +amount a b in big and L in little then +you can make a transition called fill + + align:start position:0% +you can make a transition called fill + + + align:start position:0% +you can make a transition called fill +the little jug into B in big still + + align:start position:0% +the little jug into B in big still + + + align:start position:0% +the little jug into B in big still +unchanged and three in little for L less + + align:start position:0% +unchanged and three in little for L less + + + align:start position:0% +unchanged and three in little for L less +than three I'm going to forbid the + + align:start position:0% +than three I'm going to forbid the + + + align:start position:0% +than three I'm going to forbid the +vacuous move where you the little jug is + + align:start position:0% +vacuous move where you the little jug is + + + align:start position:0% +vacuous move where you the little jug is +already F full and you try to fill it + + align:start position:0% +already F full and you try to fill it + + + align:start position:0% +already F full and you try to fill it +that doesn't count so L has to be less + + align:start position:0% +that doesn't count so L has to be less + + + align:start position:0% +that doesn't count so L has to be less +than three and you can make it three by + + align:start position:0% +than three and you can make it three by + + + align:start position:0% +than three and you can make it three by +filling the little jug similarly you can + + align:start position:0% +filling the little jug similarly you can + + + align:start position:0% +filling the little jug similarly you can +fill the big jug if B is less than five + + align:start position:0% +fill the big jug if B is less than five + + + align:start position:0% +fill the big jug if B is less than five +then you can turn it into five by + + align:start position:0% +then you can turn it into five by + + + align:start position:0% +then you can turn it into five by +filling it and then you can empty the + + align:start position:0% +filling it and then you can empty the + + + align:start position:0% +filling it and then you can empty the +little jug which is easy if you go from + + align:start position:0% +little jug which is easy if you go from + + + align:start position:0% +little jug which is easy if you go from +BL you go to be zero and likewise you + + align:start position:0% +BL you go to be zero and likewise you + + + align:start position:0% +BL you go to be zero and likewise you +can empty the big jug those are the easy + + align:start position:0% +can empty the big jug those are the easy + + + align:start position:0% +can empty the big jug those are the easy +moves a slightly more complicated move + + align:start position:0% +moves a slightly more complicated move + + + align:start position:0% +moves a slightly more complicated move +is pour the big jug into the little jug + + align:start position:0% +is pour the big jug into the little jug + + + align:start position:0% +is pour the big jug into the little jug +well if there's no Overflow what that + + align:start position:0% +well if there's no Overflow what that + + + align:start position:0% +well if there's no Overflow what that +means is that there's l in the little + + align:start position:0% +means is that there's l in the little + + + align:start position:0% +means is that there's l in the little +jug and B in the big jug and after + + align:start position:0% +jug and B in the big jug and after + + + align:start position:0% +jug and B in the big jug and after +you've poured the big jug into the + + align:start position:0% +you've poured the big jug into the + + + align:start position:0% +you've poured the big jug into the +little jug there's B plus l in the in + + align:start position:0% +little jug there's B plus l in the in + + + align:start position:0% +little jug there's B plus l in the in +the little one and nothing in the big + + align:start position:0% +the little one and nothing in the big + + + align:start position:0% +the little one and nothing in the big +one but let's be careful here about what + + align:start position:0% +one but let's be careful here about what + + + align:start position:0% +one but let's be careful here about what +exactly we're doing math we're not sort + + align:start position:0% +exactly we're doing math we're not sort + + + align:start position:0% +exactly we're doing math we're not sort +of we're trying to get away from the + + align:start position:0% +of we're trying to get away from the + + + align:start position:0% +of we're trying to get away from the +metaphor so what does no overflow means + + align:start position:0% +metaphor so what does no overflow means + + + align:start position:0% +metaphor so what does no overflow means +simply means that b plus L will fit B + + align:start position:0% +simply means that b plus L will fit B + + + align:start position:0% +simply means that b plus L will fit B +plus L is less than or equal to three + + align:start position:0% +plus L is less than or equal to three + + + align:start position:0% +plus L is less than or equal to three +all right uh what's the other case of + + align:start position:0% +all right uh what's the other case of + + + align:start position:0% +all right uh what's the other case of +pouring the big jug into the little jug + + align:start position:0% +pouring the big jug into the little jug + + + align:start position:0% +pouring the big jug into the little jug +well that's when B plus L won't fit in + + align:start position:0% +well that's when B plus L won't fit in + + + align:start position:0% +well that's when B plus L won't fit in +which case you pour into the little jug + + align:start position:0% +which case you pour into the little jug + + + align:start position:0% +which case you pour into the little jug +it's got l so you pour in 3 minus L to + + align:start position:0% +it's got l so you pour in 3 minus L to + + + align:start position:0% +it's got l so you pour in 3 minus L to +fill it up and then what's left in B is + + align:start position:0% +fill it up and then what's left in B is + + + align:start position:0% +fill it up and then what's left in B is +B minus the 3 minus little L that you + + align:start position:0% +B minus the 3 minus little L that you + + + align:start position:0% +B minus the 3 minus little L that you +poured so that's the otherwise case when + + align:start position:0% +poured so that's the otherwise case when + + + align:start position:0% +poured so that's the otherwise case when +there is Overflow and similarly there + + align:start position:0% +there is Overflow and similarly there + + + align:start position:0% +there is Overflow and similarly there +are moves for pouring the little jug + + align:start position:0% +are moves for pouring the little jug + + + align:start position:0% +are moves for pouring the little jug +into the big jug so that then is a + + align:start position:0% +into the big jug so that then is a + + + align:start position:0% +into the big jug so that then is a +formal specification of the DI hard + + align:start position:0% +formal specification of the DI hard + + + align:start position:0% +formal specification of the DI hard +machine and the moves that we're going + + align:start position:0% +machine and the moves that we're going + + + align:start position:0% +machine and the moves that we're going +to allow now you could allow other moves + + align:start position:0% +to allow now you could allow other moves + + + align:start position:0% +to allow now you could allow other moves +like randomly pouring out a little water + + align:start position:0% +like randomly pouring out a little water + + + align:start position:0% +like randomly pouring out a little water +or randomly filling up a little water + + align:start position:0% +or randomly filling up a little water + + + align:start position:0% +or randomly filling up a little water +but if you did that again you lose track + + align:start position:0% +but if you did that again you lose track + + + align:start position:0% +but if you did that again you lose track +of how much water is in the jug so these + + align:start position:0% +of how much water is in the jug so these + + + align:start position:0% +of how much water is in the jug so these +are the only safe moves and they're the + + align:start position:0% +are the only safe moves and they're the + + + align:start position:0% +are the only safe moves and they're the +only ones we're going to model all right + + align:start position:0% +only ones we're going to model all right + + + align:start position:0% +only ones we're going to model all right +so let's go back to Simon's challenge he + + align:start position:0% +so let's go back to Simon's challenge he + + + align:start position:0% +so let's go back to Simon's challenge he +wants to disarm the Bomb by getting + + align:start position:0% +wants to disarm the Bomb by getting + + + align:start position:0% +wants to disarm the Bomb by getting +exactly four gallons of water on the SC + + align:start position:0% +exactly four gallons of water on the SC + + + align:start position:0% +exactly four gallons of water on the SC +in a jug and measure it on the scale or + + align:start position:0% +in a jug and measure it on the scale or + + + align:start position:0% +in a jug and measure it on the scale or +things will blow up and how do you do it + + align:start position:0% +things will blow up and how do you do it + + + align:start position:0% +things will blow up and how do you do it +well why don't you take a moment to + + align:start position:0% +well why don't you take a moment to + + + align:start position:0% +well why don't you take a moment to +think about it before I proceed to the + + align:start position:0% +think about it before I proceed to the + + + align:start position:0% +think about it before I proceed to the +next set of slides or before you let me + + align:start position:0% +next set of slides or before you let me + + + align:start position:0% +next set of slides or before you let me +proceed but just to understand the rules + + align:start position:0% +proceed but just to understand the rules + + + align:start position:0% +proceed but just to understand the rules +again and watch them work here's how um + + align:start position:0% +again and watch them work here's how um + + + align:start position:0% +again and watch them work here's how um +we're going to start off with both jugs + + align:start position:0% +we're going to start off with both jugs + + + align:start position:0% +we're going to start off with both jugs +empty so we start off in state 00 0 and + + align:start position:0% +empty so we start off in state 00 0 and + + + align:start position:0% +empty so we start off in state 00 0 and +the first move is going to be to fill + + align:start position:0% +the first move is going to be to fill + + + align:start position:0% +the first move is going to be to fill +the big jug which takes us to State + + align:start position:0% +the big jug which takes us to State + + + align:start position:0% +the big jug which takes us to State +5 where the big jug has five and the + + align:start position:0% +5 where the big jug has five and the + + + align:start position:0% +5 where the big jug has five and the +little jug is still empty then we're + + align:start position:0% +little jug is still empty then we're + + + align:start position:0% +little jug is still empty then we're +going to pour from the big into the + + align:start position:0% +going to pour from the big into the + + + align:start position:0% +going to pour from the big into the +little so now the little jug has three + + align:start position:0% +little so now the little jug has three + + + align:start position:0% +little so now the little jug has three +we're filling up the little one that + + align:start position:0% +we're filling up the little one that + + + align:start position:0% +we're filling up the little one that +leaves two in the big + + align:start position:0% +leaves two in the big + + + align:start position:0% +leaves two in the big +jug um now we're going to empty the + + align:start position:0% +jug um now we're going to empty the + + + align:start position:0% +jug um now we're going to empty the +little one and we still have two left in + + align:start position:0% +little one and we still have two left in + + + align:start position:0% +little one and we still have two left in +the big + + align:start position:0% +the big + + + align:start position:0% +the big +one and now we're going to pour from the + + align:start position:0% +one and now we're going to pour from the + + + align:start position:0% +one and now we're going to pour from the +big one into the little one so the + + align:start position:0% +big one into the little one so the + + + align:start position:0% +big one into the little one so the +little one has two gallons and the big + + align:start position:0% +little one has two gallons and the big + + + align:start position:0% +little one has two gallons and the big +one is + + align:start position:0% +one is + + + align:start position:0% +one is +empty now we fill the big jug and + + align:start position:0% +empty now we fill the big jug and + + + align:start position:0% +empty now we fill the big jug and +there's still two gallons in the little + + align:start position:0% +there's still two gallons in the little + + + align:start position:0% +there's still two gallons in the little +one and five gallons in the big one now + + align:start position:0% +one and five gallons in the big one now + + + align:start position:0% +one and five gallons in the big one now +we pour off from the five gallon jug + + align:start position:0% +we pour off from the five gallon jug + + + align:start position:0% +we pour off from the five gallon jug +into until the one gallon jug is full + + align:start position:0% +into until the one gallon jug is full + + + align:start position:0% +into until the one gallon jug is full +that's removing the one gallon that the + + align:start position:0% +that's removing the one gallon that the + + + align:start position:0% +that's removing the one gallon that the +three gallon jug still has capacity for + + align:start position:0% +three gallon jug still has capacity for + + + align:start position:0% +three gallon jug still has capacity for +we're reduced to full three gallons in + + align:start position:0% +we're reduced to full three gallons in + + + align:start position:0% +we're reduced to full three gallons in +the little jug and four gallons our + + align:start position:0% +the little jug and four gallons our + + + align:start position:0% +the little jug and four gallons our +Target in the big jug and so we've + + align:start position:0% +Target in the big jug and so we've + + + align:start position:0% +Target in the big jug and so we've +accomplished it and we're done so the + + align:start position:0% +accomplished it and we're done so the + + + align:start position:0% +accomplished it and we're done so the +bomb doesn't go off all right so the + + align:start position:0% +bomb doesn't go off all right so the + + + align:start position:0% +bomb doesn't go off all right so the +point of this exercise is really just to + + align:start position:0% +point of this exercise is really just to + + + align:start position:0% +point of this exercise is really just to +practice how the moves work and what the + + align:start position:0% +practice how the moves work and what the + + + align:start position:0% +practice how the moves work and what the +states are but the question that I want + + align:start position:0% +states are but the question that I want + + + align:start position:0% +states are but the question that I want +to raise is uh suppose that we want to + + align:start position:0% +to raise is uh suppose that we want to + + + align:start position:0% +to raise is uh suppose that we want to +have a die hard once and for all + + align:start position:0% +have a die hard once and for all + + + align:start position:0% +have a die hard once and for all +scenario in which we're tired of the + + align:start position:0% +scenario in which we're tired of the + + + align:start position:0% +scenario in which we're tired of the +remakes of these movies and we propos + + align:start position:0% +remakes of these movies and we propos + + + align:start position:0% +remakes of these movies and we propos +that in the next movie um that Simon if + + align:start position:0% +that in the next movie um that Simon if + + + align:start position:0% +that in the next movie um that Simon if +he's still around offers an alternative + + align:start position:0% +he's still around offers an alternative + + + align:start position:0% +he's still around offers an alternative +challenge where instead of a three + + align:start position:0% +challenge where instead of a three + + + align:start position:0% +challenge where instead of a three +gallon and a five gallon jug there's a + + align:start position:0% +gallon and a five gallon jug there's a + + + align:start position:0% +gallon and a five gallon jug there's a +three gallon jug and a nine gallon jug + + align:start position:0% +three gallon jug and a nine gallon jug + + + align:start position:0% +three gallon jug and a nine gallon jug +and now the question is can you get four + + align:start position:0% +and now the question is can you get four + + + align:start position:0% +and now the question is can you get four +gallons into the big jug by pouring back + + align:start position:0% +gallons into the big jug by pouring back + + + align:start position:0% +gallons into the big jug by pouring back +and forth with rules like these or can't + + align:start position:0% +and forth with rules like these or can't + + + align:start position:0% +and forth with rules like these or can't +you and can you prove it well my guess + + align:start position:0% +you and can you prove it well my guess + + + align:start position:0% +you and can you prove it well my guess +is that you probably can figure out + + align:start position:0% +is that you probably can figure out + + + align:start position:0% +is that you probably can figure out +what's going on because what's happening + + align:start position:0% +what's going on because what's happening + + + align:start position:0% +what's going on because what's happening +is if you start off with nothing in + + align:start position:0% +is if you start off with nothing in + + + align:start position:0% +is if you start off with nothing in +either jug and you do these moves of + + align:start position:0% +either jug and you do these moves of + + + align:start position:0% +either jug and you do these moves of +filling up a jug or pouring one jug into + + align:start position:0% +filling up a jug or pouring one jug into + + + align:start position:0% +filling up a jug or pouring one jug into +another you'll discover that the amount + + align:start position:0% +another you'll discover that the amount + + + align:start position:0% +another you'll discover that the amount +of water in any jug is always divisible + + align:start position:0% +of water in any jug is always divisible + + + align:start position:0% +of water in any jug is always divisible +by three this is a preserved invariant + + align:start position:0% +by three this is a preserved invariant + + + align:start position:0% +by three this is a preserved invariant +any state that you can get to starting + + align:start position:0% +any state that you can get to starting + + + align:start position:0% +any state that you can get to starting +off from 0 three will divide the number + + align:start position:0% +off from 0 three will divide the number + + + align:start position:0% +off from 0 three will divide the number +of gallons in each jug we could state it + + align:start position:0% +of gallons in each jug we could state it + + + align:start position:0% +of gallons in each jug we could state it +this way there's a property of states + + align:start position:0% +this way there's a property of states + + + align:start position:0% +this way there's a property of states +property of B and L which is the state + + align:start position:0% +property of B and L which is the state + + + align:start position:0% +property of B and L which is the state +which is that 3 divides B that vertical + + align:start position:0% +which is that 3 divides B that vertical + + + align:start position:0% +which is that 3 divides B that vertical +uh line is is a Shand for the symbol + + align:start position:0% +uh line is is a Shand for the symbol + + + align:start position:0% +uh line is is a Shand for the symbol +divides so three divides b or B is a + + align:start position:0% +divides so three divides b or B is a + + + align:start position:0% +divides so three divides b or B is a +multiple of three 3 divides L synonym L + + align:start position:0% +multiple of three 3 divides L synonym L + + + align:start position:0% +multiple of three 3 divides L synonym L +is a multiple of three and the claim is + + align:start position:0% +is a multiple of three and the claim is + + + align:start position:0% +is a multiple of three and the claim is +that that's always going to be + + align:start position:0% +that that's always going to be + + + align:start position:0% +that that's always going to be +true so in case that's not obvious you + + align:start position:0% +true so in case that's not obvious you + + + align:start position:0% +true so in case that's not obvious you +might not have all the rules in your + + align:start position:0% +might not have all the rules in your + + + align:start position:0% +might not have all the rules in your +head but let's just take an ex look at + + align:start position:0% +head but let's just take an ex look at + + + align:start position:0% +head but let's just take an ex look at +one of the more complicated rules this + + align:start position:0% +one of the more complicated rules this + + + align:start position:0% +one of the more complicated rules this +was the rule where you're pouring the + + align:start position:0% +was the rule where you're pouring the + + + align:start position:0% +was the rule where you're pouring the +big J into the little jug up till the + + align:start position:0% +big J into the little jug up till the + + + align:start position:0% +big J into the little jug up till the +until the little jug is full um and that + + align:start position:0% +until the little jug is full um and that + + + align:start position:0% +until the little jug is full um and that +transition is that if you're in state b + + align:start position:0% +transition is that if you're in state b + + + align:start position:0% +transition is that if you're in state b +l you move to B minus 3 minus L and + + align:start position:0% +l you move to B minus 3 minus L and + + + align:start position:0% +l you move to B minus 3 minus L and +three and if you look at this now + + align:start position:0% +three and if you look at this now + + + align:start position:0% +three and if you look at this now +clearly if three divides both B and L + + align:start position:0% +clearly if three divides both B and L + + + align:start position:0% +clearly if three divides both B and L +both components of the state you're at + + align:start position:0% +both components of the state you're at + + + align:start position:0% +both components of the state you're at +then in the new state well three + + align:start position:0% +then in the new state well three + + + align:start position:0% +then in the new state well three +obviously divides the contents of the + + align:start position:0% +obviously divides the contents of the + + + align:start position:0% +obviously divides the contents of the +little jug which is three but three also + + align:start position:0% +little jug which is three but three also + + + align:start position:0% +little jug which is three but three also +divides the contents of the big jug + + align:start position:0% +divides the contents of the big jug + + + align:start position:0% +divides the contents of the big jug +which is a multiple of three namely B + + align:start position:0% +which is a multiple of three namely B + + + align:start position:0% +which is a multiple of three namely B +minus 3 which is a multiple of 3 minus W + + align:start position:0% +minus 3 which is a multiple of 3 minus W + + + align:start position:0% +minus 3 which is a multiple of 3 minus W +which is a multiple of three when you + + align:start position:0% +which is a multiple of three when you + + + align:start position:0% +which is a multiple of three when you +take a linear combination of multiples + + align:start position:0% +take a linear combination of multiples + + + align:start position:0% +take a linear combination of multiples +of three you get a multiple of three and + + align:start position:0% +of three you get a multiple of three and + + + align:start position:0% +of three you get a multiple of three and +you look at all the other Transitions + + align:start position:0% +you look at all the other Transitions + + + align:start position:0% +you look at all the other Transitions +and they check equally well if you're in + + align:start position:0% +and they check equally well if you're in + + + align:start position:0% +and they check equally well if you're in +a state BL and you move to a new state B + + align:start position:0% +a state BL and you move to a new state B + + + align:start position:0% +a state BL and you move to a new state B +Prime L + + align:start position:0% +Prime L + + + align:start position:0% +Prime L +Prime if 3 divides B and L then 3 + + align:start position:0% +Prime if 3 divides B and L then 3 + + + align:start position:0% +Prime if 3 divides B and L then 3 +divides B Prime and L Prime so this is + + align:start position:0% +divides B Prime and L Prime so this is + + + align:start position:0% +divides B Prime and L Prime so this is +what's called a preserved invariant + + align:start position:0% + + + + align:start position:0% + +and of course the Cory is that in the + + align:start position:0% +and of course the Cory is that in the + + + align:start position:0% +and of course the Cory is that in the +Die Hard once and for all game with the + + align:start position:0% +Die Hard once and for all game with the + + + align:start position:0% +Die Hard once and for all game with the +three jug three gallon jug and the nine + + align:start position:0% +three jug three gallon jug and the nine + + + align:start position:0% +three jug three gallon jug and the nine +gallon jug you can't get to any state of + + align:start position:0% +gallon jug you can't get to any state of + + + align:start position:0% +gallon jug you can't get to any state of +the form 4X because four is not + + align:start position:0% +the form 4X because four is not + + + align:start position:0% +the form 4X because four is not +divisible by three and therefore Bruce + + align:start position:0% +divisible by three and therefore Bruce + + + align:start position:0% +divisible by three and therefore Bruce +is going to + + align:start position:0% +is going to + + + align:start position:0% +is going to +die now what we've Illustrated here is + + align:start position:0% +die now what we've Illustrated here is + + + align:start position:0% +die now what we've Illustrated here is +an argument that's known as Floyd's + + align:start position:0% +an argument that's known as Floyd's + + + align:start position:0% +an argument that's known as Floyd's +invariant principle and it's really + + align:start position:0% +invariant principle and it's really + + + align:start position:0% +invariant principle and it's really +nothing but induction reformulated for + + align:start position:0% +nothing but induction reformulated for + + + align:start position:0% +nothing but induction reformulated for +State machines the uh statement of + + align:start position:0% +State machines the uh statement of + + + align:start position:0% +State machines the uh statement of +Floyd's invariant principle is that + + align:start position:0% +Floyd's invariant principle is that + + + align:start position:0% +Floyd's invariant principle is that +we're going to define a preserved + + align:start position:0% +we're going to define a preserved + + + align:start position:0% +we're going to define a preserved +invariant is a property of states and a + + align:start position:0% +invariant is a property of states and a + + + align:start position:0% +invariant is a property of states and a +preserved invariant means it has the + + align:start position:0% +preserved invariant means it has the + + + align:start position:0% +preserved invariant means it has the +property that if you're in a state that + + align:start position:0% +property that if you're in a state that + + + align:start position:0% +property that if you're in a state that +has property p and it's possible to make + + align:start position:0% +has property p and it's possible to make + + + align:start position:0% +has property p and it's possible to make +a single transition to a state R then R + + align:start position:0% +a single transition to a state R then R + + + align:start position:0% +a single transition to a state R then R +will also have property P this is just + + align:start position:0% +will also have property P this is just + + + align:start position:0% +will also have property P this is just +like the induction step you have to + + align:start position:0% +like the induction step you have to + + + align:start position:0% +like the induction step you have to +prove that P of n implies P of n plus + + align:start position:0% +prove that P of n implies P of n plus + + + align:start position:0% +prove that P of n implies P of n plus +one so if you have a preserved + + align:start position:0% +one so if you have a preserved + + + align:start position:0% +one so if you have a preserved +invariant uh then uh + + align:start position:0% +invariant uh then uh + + + align:start position:0% +invariant uh then uh +if the property holds at the start State + + align:start position:0% +if the property holds at the start State + + + align:start position:0% +if the property holds at the start State +then it's obvious uh that the property + + align:start position:0% +then it's obvious uh that the property + + + align:start position:0% +then it's obvious uh that the property +will hold for all of the states that you + + align:start position:0% +will hold for all of the states that you + + + align:start position:0% +will hold for all of the states that you +can possibly get to uh that P of R will + + align:start position:0% +can possibly get to uh that P of R will + + + align:start position:0% +can possibly get to uh that P of R will +hold for all reachable states you can + + align:start position:0% +hold for all reachable states you can + + + align:start position:0% +hold for all reachable states you can +prove this by induction on the number of + + align:start position:0% +prove this by induction on the number of + + + align:start position:0% +prove this by induction on the number of +states but I think it's clear that if + + align:start position:0% +states but I think it's clear that if + + + align:start position:0% +states but I think it's clear that if +you have a property that you begin with + + align:start position:0% +you have a property that you begin with + + + align:start position:0% +you have a property that you begin with +and it doesn't change making a step it's + + align:start position:0% +and it doesn't change making a step it's + + + align:start position:0% +and it doesn't change making a step it's +never going to change and that's all + + align:start position:0% +never going to change and that's all + + + align:start position:0% +never going to change and that's all +that Floyd's invariant principle states + + align:start position:0% +that Floyd's invariant principle states + + + align:start position:0% +that Floyd's invariant principle states +so in particular uh since the prop + + align:start position:0% +so in particular uh since the prop + + + align:start position:0% +so in particular uh since the prop +property P holds in all reachable states + + align:start position:0% +property P holds in all reachable states + + + align:start position:0% +property P holds in all reachable states +if there is any final state which which + + align:start position:0% +if there is any final state which which + + + align:start position:0% +if there is any final state which which +the machine reaches then p is going to + + align:start position:0% +the machine reaches then p is going to + + + align:start position:0% +the machine reaches then p is going to +hold in that state and what we saw was + + align:start position:0% +hold in that state and what we saw was + + + align:start position:0% +hold in that state and what we saw was +that incidentally we're using the word + + align:start position:0% +that incidentally we're using the word + + + align:start position:0% +that incidentally we're using the word +preserved invariant to distinguish the + + align:start position:0% +preserved invariant to distinguish the + + + align:start position:0% +preserved invariant to distinguish the +definition here from uh another usage + + align:start position:0% +definition here from uh another usage + + + align:start position:0% +definition here from uh another usage +that's co-opted the word invariant to + + align:start position:0% +that's co-opted the word invariant to + + + align:start position:0% +that's co-opted the word invariant to +mean a property that's true in all + + align:start position:0% +mean a property that's true in all + + + align:start position:0% +mean a property that's true in all +states uh and while it's nice to know + + align:start position:0% +states uh and while it's nice to know + + + align:start position:0% +states uh and while it's nice to know +that some property is true in all states + + align:start position:0% +that some property is true in all states + + + align:start position:0% +that some property is true in all states +uh the way you prove that is by having + + align:start position:0% +uh the way you prove that is by having + + + align:start position:0% +uh the way you prove that is by having +having a preserved invariant so you want + + align:start position:0% +having a preserved invariant so you want + + + align:start position:0% +having a preserved invariant so you want +to distinguish the two technically if + + align:start position:0% +to distinguish the two technically if + + + align:start position:0% +to distinguish the two technically if +you look at this the predicate that's + + align:start position:0% +you look at this the predicate that's + + + align:start position:0% +you look at this the predicate that's +always false is a preserved invariant + + align:start position:0% +always false is a preserved invariant + + + align:start position:0% +always false is a preserved invariant +because uh of the condition as usual the + + align:start position:0% +because uh of the condition as usual the + + + align:start position:0% +because uh of the condition as usual the +way implication works if the antecedent + + align:start position:0% +way implication works if the antecedent + + + align:start position:0% +way implication works if the antecedent +is false then the entire implication is + + align:start position:0% +is false then the entire implication is + + + align:start position:0% +is false then the entire implication is +true so if you're always false then it's + + align:start position:0% +true so if you're always false then it's + + + align:start position:0% +true so if you're always false then it's +always the case that if false held in a + + align:start position:0% +always the case that if false held in a + + + align:start position:0% +always the case that if false held in a +state which it never does then it has to + + align:start position:0% +state which it never does then it has to + + + align:start position:0% +state which it never does then it has to +hold in any state you can get to so the + + align:start position:0% +hold in any state you can get to so the + + + align:start position:0% +hold in any state you can get to so the +that implication is true so just + + align:start position:0% +that implication is true so just + + + align:start position:0% +that implication is true so just +remember that preserved invariants that + + align:start position:0% +remember that preserved invariants that + + + align:start position:0% +remember that preserved invariants that +are constantly false uh exist uh they + + align:start position:0% +are constantly false uh exist uh they + + + align:start position:0% +are constantly false uh exist uh they +are good preserved invariants but + + align:start position:0% +are good preserved invariants but + + + align:start position:0% +are good preserved invariants but +they're not what other people would call + + align:start position:0% +they're not what other people would call + + + align:start position:0% +they're not what other people would call +an invariant we use preserved invariants + + align:start position:0% +an invariant we use preserved invariants + + + align:start position:0% +an invariant we use preserved invariants +to prove that a property is true in all + + align:start position:0% +to prove that a property is true in all + + + align:start position:0% +to prove that a property is true in all +states it's a + + align:start position:0% + + + + align:start position:0% + +methodology so let's do one more example + + align:start position:0% +methodology so let's do one more example + + + align:start position:0% +methodology so let's do one more example +to wrap this up suppose I have a robot + + align:start position:0% +to wrap this up suppose I have a robot + + + align:start position:0% +to wrap this up suppose I have a robot +on a grid and the integer grid and we + + align:start position:0% +on a grid and the integer grid and we + + + align:start position:0% +on a grid and the integer grid and we +can think then of the coordinates of the + + align:start position:0% +can think then of the coordinates of the + + + align:start position:0% +can think then of the coordinates of the +integer as a pair of the coordinates of + + align:start position:0% +integer as a pair of the coordinates of + + + align:start position:0% +integer as a pair of the coordinates of +the robot as the coordinates of the + + align:start position:0% +the robot as the coordinates of the + + + align:start position:0% +the robot as the coordinates of the +square that it's in a pair of non- + + align:start position:0% +square that it's in a pair of non- + + + align:start position:0% +square that it's in a pair of non- +negative + + align:start position:0% +negative + + + align:start position:0% +negative +integers now the way this robot can move + + align:start position:0% +integers now the way this robot can move + + + align:start position:0% +integers now the way this robot can move +is it can make a diagonal move in one + + align:start position:0% +is it can make a diagonal move in one + + + align:start position:0% +is it can make a diagonal move in one +step so it can move one step to the + + align:start position:0% +step so it can move one step to the + + + align:start position:0% +step so it can move one step to the +northeast or Southeast or Northwest or + + align:start position:0% +northeast or Southeast or Northwest or + + + align:start position:0% +northeast or Southeast or Northwest or +Southwest and that's it and the question + + align:start position:0% +Southwest and that's it and the question + + + align:start position:0% +Southwest and that's it and the question +that I want to ask is suppose you start + + align:start position:0% +that I want to ask is suppose you start + + + align:start position:0% +that I want to ask is suppose you start +the robot off at the origin at + + align:start position:0% +the robot off at the origin at + + + align:start position:0% +the robot off at the origin at +0 is there some way that it can wander + + align:start position:0% +0 is there some way that it can wander + + + align:start position:0% +0 is there some way that it can wander +around following its moves and get to a + + align:start position:0% +around following its moves and get to a + + + align:start position:0% +around following its moves and get to a +net state where it's moved Square over + + align:start position:0% +net state where it's moved Square over + + + align:start position:0% +net state where it's moved Square over +that is it gets to the square uh + + align:start position:0% +that is it gets to the square uh + + + align:start position:0% +that is it gets to the square uh +01 and uh the answer to that is settled + + align:start position:0% +01 and uh the answer to that is settled + + + align:start position:0% +01 and uh the answer to that is settled +Again by a preserved invariant I don't + + align:start position:0% +Again by a preserved invariant I don't + + + align:start position:0% +Again by a preserved invariant I don't +know whether it's obvious to you yet but + + align:start position:0% +know whether it's obvious to you yet but + + + align:start position:0% +know whether it's obvious to you yet but +it will be in a moment I'm claiming you + + align:start position:0% +it will be in a moment I'm claiming you + + + align:start position:0% +it will be in a moment I'm claiming you +can't get to the square 01 and the + + align:start position:0% +can't get to the square 01 and the + + + align:start position:0% +can't get to the square 01 and the +reason is that there's a preserved + + align:start position:0% +reason is that there's a preserved + + + align:start position:0% +reason is that there's a preserved +invariant of that set of robot moves + + align:start position:0% +invariant of that set of robot moves + + + align:start position:0% +invariant of that set of robot moves +namely the sum of the coordinates is + + align:start position:0% +namely the sum of the coordinates is + + + align:start position:0% +namely the sum of the coordinates is +even is an invariant if the sum of the + + align:start position:0% +even is an invariant if the sum of the + + + align:start position:0% +even is an invariant if the sum of the +coordinates is even it stays even and + + align:start position:0% +coordinates is even it stays even and + + + align:start position:0% +coordinates is even it stays even and +why is that well any move uh adds plus + + align:start position:0% +why is that well any move uh adds plus + + + align:start position:0% +why is that well any move uh adds plus +or minus one to the coordinates of both + + align:start position:0% +or minus one to the coordinates of both + + + align:start position:0% +or minus one to the coordinates of both +X and Y um maybe uh X and Y uh both go + + align:start position:0% +X and Y um maybe uh X and Y uh both go + + + align:start position:0% +X and Y um maybe uh X and Y uh both go +up by one in which case the sum of X and + + align:start position:0% +up by one in which case the sum of X and + + + align:start position:0% +up by one in which case the sum of X and +Y increases by two so if it was even it + + align:start position:0% +Y increases by two so if it was even it + + + align:start position:0% +Y increases by two so if it was even it +stays even or they both go down by one + + align:start position:0% +stays even or they both go down by one + + + align:start position:0% +stays even or they both go down by one +or maybe one goes up and the other goes + + align:start position:0% +or maybe one goes up and the other goes + + + align:start position:0% +or maybe one goes up and the other goes +down in which case the sum doesn't + + align:start position:0% +down in which case the sum doesn't + + + align:start position:0% +down in which case the sum doesn't +change in every case um uh if X Plus y + + align:start position:0% +change in every case um uh if X Plus y + + + align:start position:0% +change in every case um uh if X Plus y +was even it stays even and as a matter + + align:start position:0% +was even it stays even and as a matter + + + align:start position:0% +was even it stays even and as a matter +of fact if it was odd it stays odd moves + + align:start position:0% +of fact if it was odd it stays odd moves + + + align:start position:0% +of fact if it was odd it stays odd moves +actually preserve the parity of X Plus y + + align:start position:0% +actually preserve the parity of X Plus y + + + align:start position:0% +actually preserve the parity of X Plus y +but the invariant is that x + y is even + + align:start position:0% +but the invariant is that x + y is even + + + align:start position:0% +but the invariant is that x + y is even +now what else is the case well 0 0 uh 0 + + align:start position:0% +now what else is the case well 0 0 uh 0 + + + align:start position:0% +now what else is the case well 0 0 uh 0 +plus 0 is z which is even and so we're + + align:start position:0% +plus 0 is z which is even and so we're + + + align:start position:0% +plus 0 is z which is even and so we're +in a Floyd invariant principle case + + align:start position:0% +in a Floyd invariant principle case + + + align:start position:0% +in a Floyd invariant principle case +where uh all the positions you can get + + align:start position:0% +where uh all the positions you can get + + + align:start position:0% +where uh all the positions you can get +to from the origin 0 0 which has an even + + align:start position:0% +to from the origin 0 0 which has an even + + + align:start position:0% +to from the origin 0 0 which has an even +sum have to have an even sum and since + + align:start position:0% +sum have to have an even sum and since + + + align:start position:0% +sum have to have an even sum and since +uh 1+0 is odd you can't get to that + + align:start position:0% +uh 1+0 is odd you can't get to that + + + align:start position:0% +uh 1+0 is odd you can't get to that +square one Z it's not + + align:start position:0% + + + + align:start position:0% + +reachable so the parody and variant of + + align:start position:0% +reachable so the parody and variant of + + + align:start position:0% +reachable so the parody and variant of +the diagonally moving robot will set us + + align:start position:0% +the diagonally moving robot will set us + + + align:start position:0% +the diagonally moving robot will set us +up for uh an analysis of the 15 puzzle + + align:start position:0% +up for uh an analysis of the 15 puzzle + + + align:start position:0% +up for uh an analysis of the 15 puzzle +game that's this logo that we've had on + + align:start position:0% +game that's this logo that we've had on + + + align:start position:0% +game that's this logo that we've had on +every slide in 6042 so far with six + + align:start position:0% +every slide in 6042 so far with six + + + align:start position:0% +every slide in 6042 so far with six +blank 42 on the diagonal uh this is a + + align:start position:0% +blank 42 on the diagonal uh this is a + + + align:start position:0% +blank 42 on the diagonal uh this is a +game where there are these little + + align:start position:0% +game where there are these little + + + align:start position:0% +game where there are these little +numbered SL tiles that slide into the + + align:start position:0% +numbered SL tiles that slide into the + + + align:start position:0% +numbered SL tiles that slide into the +blank square and the question is how to + + align:start position:0% +blank square and the question is how to + + + align:start position:0% +blank square and the question is how to +permute um how to get from one + + align:start position:0% +permute um how to get from one + + + align:start position:0% +permute um how to get from one +permutation of the numbers to another uh + + align:start position:0% +permutation of the numbers to another uh + + + align:start position:0% +permutation of the numbers to another uh +and it turns out that the analysis of + + align:start position:0% +and it turns out that the analysis of + + + align:start position:0% +and it turns out that the analysis of +that game depends on a parody invariant + + align:start position:0% +that game depends on a parody invariant + + + align:start position:0% +that game depends on a parody invariant +uh reminiscent of well slightly more + + align:start position:0% +uh reminiscent of well slightly more + + + align:start position:0% +uh reminiscent of well slightly more +sophisticated than the diagonally moving + + align:start position:0% +sophisticated than the diagonally moving + + + align:start position:0% +sophisticated than the diagonally moving +robot let's look at one more example of + + align:start position:0% +robot let's look at one more example of + + + align:start position:0% +robot let's look at one more example of +uh using the invariant to verify y a + + align:start position:0% +uh using the invariant to verify y a + + + align:start position:0% +uh using the invariant to verify y a +little algorithm that actually will be + + align:start position:0% +little algorithm that actually will be + + + align:start position:0% +little algorithm that actually will be +quite important uh as the course + + align:start position:0% +quite important uh as the course + + + align:start position:0% +quite important uh as the course +progresses and that is fast + + align:start position:0% +progresses and that is fast + + + align:start position:0% +progresses and that is fast +exponentiation so in this setup um a is + + align:start position:0% +exponentiation so in this setup um a is + + + align:start position:0% +exponentiation so in this setup um a is +a real number and B is a non- negative + + align:start position:0% +a real number and B is a non- negative + + + align:start position:0% +a real number and B is a non- negative +integer and I want to compute the be + + align:start position:0% +integer and I want to compute the be + + + align:start position:0% +integer and I want to compute the be +power of a let's say uh B was uh uh 128 + + align:start position:0% +power of a let's say uh B was uh uh 128 + + + align:start position:0% +power of a let's say uh B was uh uh 128 +and I want to compute the 128th power of + + align:start position:0% +and I want to compute the 128th power of + + + align:start position:0% +and I want to compute the 128th power of +some real number a well I can multiply a + + align:start position:0% +some real number a well I can multiply a + + + align:start position:0% +some real number a well I can multiply a +by itself 127 times that would work fine + + align:start position:0% +by itself 127 times that would work fine + + + align:start position:0% +by itself 127 times that would work fine +but if you think about it suppose I + + align:start position:0% +but if you think about it suppose I + + + align:start position:0% +but if you think about it suppose I +square a and then I Square it again and + + align:start position:0% +square a and then I Square it again and + + + align:start position:0% +square a and then I Square it again and +I Square it again then in about eight + + align:start position:0% +I Square it again then in about eight + + + align:start position:0% +I Square it again then in about eight +squarings instead of 99 multiplications + + align:start position:0% +squarings instead of 99 multiplications + + + align:start position:0% +squarings instead of 99 multiplications +I'm going to get to a to the + + align:start position:0% +I'm going to get to a to the + + + align:start position:0% +I'm going to get to a to the +128 U now if B is not a power of two you + + align:start position:0% +128 U now if B is not a power of two you + + + align:start position:0% +128 U now if B is not a power of two you +adjust it slightly uh and using that + + align:start position:0% +adjust it slightly uh and using that + + + align:start position:0% +adjust it slightly uh and using that +idea you can compute the uh be power of + + align:start position:0% +idea you can compute the uh be power of + + + align:start position:0% +idea you can compute the uh be power of +a much more rapidly than if you just + + align:start position:0% +a much more rapidly than if you just + + + align:start position:0% +a much more rapidly than if you just +naively multiplied out B minus1 times so + + align:start position:0% +naively multiplied out B minus1 times so + + + align:start position:0% +naively multiplied out B minus1 times so +let's look at the pseudo code for this + + align:start position:0% +let's look at the pseudo code for this + + + align:start position:0% +let's look at the pseudo code for this +algorithm uh here uh X YZ and R are + + align:start position:0% +algorithm uh here uh X YZ and R are + + + align:start position:0% +algorithm uh here uh X YZ and R are +temporary registers um uh Y and Z hold + + align:start position:0% +temporary registers um uh Y and Z hold + + + align:start position:0% +temporary registers um uh Y and Z hold +uh uh YZ and R all hold integers and X + + align:start position:0% +uh uh YZ and R all hold integers and X + + + align:start position:0% +uh uh YZ and R all hold integers and X +holds this real number a uh and you can + + align:start position:0% +holds this real number a uh and you can + + + align:start position:0% +holds this real number a uh and you can +read the code um if you wish but in fact + + align:start position:0% +read the code um if you wish but in fact + + + align:start position:0% +read the code um if you wish but in fact +I'm going to immediately jump to the + + align:start position:0% +I'm going to immediately jump to the + + + align:start position:0% +I'm going to immediately jump to the +slightly more abstract and easier to + + align:start position:0% +slightly more abstract and easier to + + + align:start position:0% +slightly more abstract and easier to +understand version of it as a state + + align:start position:0% +understand version of it as a state + + + align:start position:0% +understand version of it as a state +machine so what matters about this fast + + align:start position:0% +machine so what matters about this fast + + + align:start position:0% +machine so what matters about this fast +exponentiation algorithm as a state + + align:start position:0% +exponentiation algorithm as a state + + + align:start position:0% +exponentiation algorithm as a state +machine is that first of all um there + + align:start position:0% +machine is that first of all um there + + + align:start position:0% +machine is that first of all um there +are three states uh two real numbers + + align:start position:0% +are three states uh two real numbers + + + align:start position:0% +are three states uh two real numbers +numbers and uh a non- negative + + align:start position:0% +numbers and uh a non- negative + + + align:start position:0% +numbers and uh a non- negative +integer um and the start state is going + + align:start position:0% +integer um and the start state is going + + + align:start position:0% +integer um and the start state is going +to be that the number a is in the first + + align:start position:0% +to be that the number a is in the first + + + align:start position:0% +to be that the number a is in the first +register or in the first location first + + align:start position:0% +register or in the first location first + + + align:start position:0% +register or in the first location first +coordinate of the states one is the real + + align:start position:0% +coordinate of the states one is the real + + + align:start position:0% +coordinate of the states one is the real +number in the second coordinate and B + + align:start position:0% +number in the second coordinate and B + + + align:start position:0% +number in the second coordinate and B +the target exponent uh is the non- + + align:start position:0% +the target exponent uh is the non- + + + align:start position:0% +the target exponent uh is the non- +negative integer in the third + + align:start position:0% +negative integer in the third + + + align:start position:0% +negative integer in the third +component um the transitions are going + + align:start position:0% +component um the transitions are going + + + align:start position:0% +component um the transitions are going +to be as follows here's a simple one uh + + align:start position:0% +to be as follows here's a simple one uh + + + align:start position:0% +to be as follows here's a simple one uh +if I have an amount X in the first + + align:start position:0% +if I have an amount X in the first + + + align:start position:0% +if I have an amount X in the first +location y in the second location Z in + + align:start position:0% +location y in the second location Z in + + + align:start position:0% +location y in the second location Z in +the third then if Z is if Z is positive + + align:start position:0% +the third then if Z is if Z is positive + + + align:start position:0% +the third then if Z is if Z is positive +and + + align:start position:0% +and + + + align:start position:0% +and +even then I'm going to square X leave y + + align:start position:0% +even then I'm going to square X leave y + + + align:start position:0% +even then I'm going to square X leave y +alone and divide Z by + + align:start position:0% +alone and divide Z by + + + align:start position:0% +alone and divide Z by +two and that's the new state that I get + + align:start position:0% +two and that's the new state that I get + + + align:start position:0% +two and that's the new state that I get +at on the other hand if Z is odd and + + align:start position:0% +at on the other hand if Z is odd and + + + align:start position:0% +at on the other hand if Z is odd and +positive then I'm going to square X + + align:start position:0% +positive then I'm going to square X + + + align:start position:0% +positive then I'm going to square X +multiply y by X and again take the + + align:start position:0% +multiply y by X and again take the + + + align:start position:0% +multiply y by X and again take the +quotient of Z divide Z by + + align:start position:0% +quotient of Z divide Z by + + + align:start position:0% +quotient of Z divide Z by +two okay why does this state machine do + + align:start position:0% +two okay why does this state machine do + + + align:start position:0% +two okay why does this state machine do +fast exponentiation why is it correct + + align:start position:0% +fast exponentiation why is it correct + + + align:start position:0% +fast exponentiation why is it correct +and the Insight is that there's a + + align:start position:0% +and the Insight is that there's a + + + align:start position:0% +and the Insight is that there's a +preserved invariant of this machine and + + align:start position:0% +preserved invariant of this machine and + + + align:start position:0% +preserved invariant of this machine and +the preserved invariant is that y * x to + + align:start position:0% +the preserved invariant is that y * x to + + + align:start position:0% +the preserved invariant is that y * x to +the Z is always a to the B so let's see + + align:start position:0% +the Z is always a to the B so let's see + + + align:start position:0% +the Z is always a to the B so let's see +how to verify that that uh y x to the Z + + align:start position:0% +how to verify that that uh y x to the Z + + + align:start position:0% +how to verify that that uh y x to the Z +is equal to a to the B well let's just + + align:start position:0% +is equal to a to the B well let's just + + + align:start position:0% +is equal to a to the B well let's just +look at uh maybe the slightly more + + align:start position:0% +look at uh maybe the slightly more + + + align:start position:0% +look at uh maybe the slightly more +interesting of the two transition rules + + align:start position:0% +interesting of the two transition rules + + + align:start position:0% +interesting of the two transition rules +which is when Z is positive in odd uh + + align:start position:0% +which is when Z is positive in odd uh + + + align:start position:0% +which is when Z is positive in odd uh +the XYZ State moves to a new State uh + + align:start position:0% +the XYZ State moves to a new State uh + + + align:start position:0% +the XYZ State moves to a new State uh +indicated in green where the new value + + align:start position:0% +indicated in green where the new value + + + align:start position:0% +indicated in green where the new value +of x is X squ the new value of y is XY + + align:start position:0% +of x is X squ the new value of y is XY + + + align:start position:0% +of x is X squ the new value of y is XY +and the new value of Z is z minus 1 + + align:start position:0% +and the new value of Z is z minus 1 + + + align:start position:0% +and the new value of Z is z minus 1 +over2 remember you went to the quotient + + align:start position:0% +over2 remember you went to the quotient + + + align:start position:0% +over2 remember you went to the quotient +of Z ided two and when Z is odd that + + align:start position:0% +of Z ided two and when Z is odd that + + + align:start position:0% +of Z ided two and when Z is odd that +means Z it's literally Z minus1 /2 well + + align:start position:0% +means Z it's literally Z minus1 /2 well + + + align:start position:0% +means Z it's literally Z minus1 /2 well +do the new values satisfy the invariant + + align:start position:0% +do the new values satisfy the invariant + + + align:start position:0% +do the new values satisfy the invariant +if if I plug in the green values uh of + + align:start position:0% +if if I plug in the green values uh of + + + align:start position:0% +if if I plug in the green values uh of +x^2 for y and XY for x uh for sorry X2 + + align:start position:0% +x^2 for y and XY for x uh for sorry X2 + + + align:start position:0% +x^2 for y and XY for x uh for sorry X2 +for X XY for y and z-1 over2 for Z well + + align:start position:0% +for X XY for y and z-1 over2 for Z well + + + align:start position:0% +for X XY for y and z-1 over2 for Z well +let's see what happens um if I uh uh + + align:start position:0% +let's see what happens um if I uh uh + + + align:start position:0% +let's see what happens um if I uh uh +take uh the new value of y which is XY + + align:start position:0% +take uh the new value of y which is XY + + + align:start position:0% +take uh the new value of y which is XY +um and I multiply it by the new value of + + align:start position:0% +um and I multiply it by the new value of + + + align:start position:0% +um and I multiply it by the new value of +x which is X2 raised to the new value of + + align:start position:0% +x which is X2 raised to the new value of + + + align:start position:0% +x which is X2 raised to the new value of +Z which is z minus1 / 2 uh let's do a + + align:start position:0% +Z which is z minus1 / 2 uh let's do a + + + align:start position:0% +Z which is z minus1 / 2 uh let's do a +little algebra simplification of that + + align:start position:0% +little algebra simplification of that + + + align:start position:0% +little algebra simplification of that +well the x^2 to the z-1 / 2 becomes X + + align:start position:0% +well the x^2 to the z-1 / 2 becomes X + + + align:start position:0% +well the x^2 to the z-1 / 2 becomes X +the Z minus1 uh and I'm just carrying + + align:start position:0% +the Z minus1 uh and I'm just carrying + + + align:start position:0% +the Z minus1 uh and I'm just carrying +over the XY uh and then that simplifies + + align:start position:0% +over the XY uh and then that simplifies + + + align:start position:0% +over the XY uh and then that simplifies +to Simply uh y * x * X the Z minus1 or + + align:start position:0% +to Simply uh y * x * X the Z minus1 or + + + align:start position:0% +to Simply uh y * x * X the Z minus1 or +YX to the Z which we assumed was equal + + align:start position:0% +YX to the Z which we assumed was equal + + + align:start position:0% +YX to the Z which we assumed was equal +to a to the B so sure enough the new + + align:start position:0% +to a to the B so sure enough the new + + + align:start position:0% +to a to the B so sure enough the new +values of X Y and Z satisfy the + + align:start position:0% +values of X Y and Z satisfy the + + + align:start position:0% +values of X Y and Z satisfy the +invariant it is a preserved invariant + + align:start position:0% +invariant it is a preserved invariant + + + align:start position:0% +invariant it is a preserved invariant +and an even simpler argument applies to + + align:start position:0% +and an even simpler argument applies to + + + align:start position:0% +and an even simpler argument applies to +the other the transition when Z is + + align:start position:0% +the other the transition when Z is + + + align:start position:0% +the other the transition when Z is +positive and even so we verified that + + align:start position:0% +positive and even so we verified that + + + align:start position:0% +positive and even so we verified that +this is a preserved invariant now at the + + align:start position:0% +this is a preserved invariant now at the + + + align:start position:0% +this is a preserved invariant now at the +start uh remember we start off with uh + + align:start position:0% +start uh remember we start off with uh + + + align:start position:0% +start uh remember we start off with uh +the real number a in register X the real + + align:start position:0% +the real number a in register X the real + + + align:start position:0% +the real number a in register X the real +number B in Z and the real number one in + + align:start position:0% +number B in Z and the real number one in + + + align:start position:0% +number B in Z and the real number one in +Y which is the accumulator and uh 1 * a + + align:start position:0% +Y which is the accumulator and uh 1 * a + + + align:start position:0% +Y which is the accumulator and uh 1 * a +the B is equal to a to the B so this is + + align:start position:0% +the B is equal to a to the B so this is + + + align:start position:0% +the B is equal to a to the B so this is +a this preserved invariant is true of + + align:start position:0% +a this preserved invariant is true of + + + align:start position:0% +a this preserved invariant is true of +the start State and that means by Floyds + + align:start position:0% +the start State and that means by Floyds + + + align:start position:0% +the start State and that means by Floyds +variant principle that it is true at + + align:start position:0% +variant principle that it is true at + + + align:start position:0% +variant principle that it is true at +this the final state if and when the + + align:start position:0% +this the final state if and when the + + + align:start position:0% +this the final state if and when the +thing stops well when does this machine + + align:start position:0% +thing stops well when does this machine + + + align:start position:0% +thing stops well when does this machine +stop as long as Z is positive it can + + align:start position:0% +stop as long as Z is positive it can + + + align:start position:0% +stop as long as Z is positive it can +keep moving so it gets stuck when Z is + + align:start position:0% +keep moving so it gets stuck when Z is + + + align:start position:0% +keep moving so it gets stuck when Z is +zero what happens if it ever gets to Z a + + align:start position:0% +zero what happens if it ever gets to Z a + + + align:start position:0% +zero what happens if it ever gets to Z a +zero if it gets stuck then the + + align:start position:0% +zero if it gets stuck then the + + + align:start position:0% +zero if it gets stuck then the +invariance says that YX to the 0 has to + + align:start position:0% +invariance says that YX to the 0 has to + + + align:start position:0% +invariance says that YX to the 0 has to +equal to a to the B but of course YX to + + align:start position:0% +equal to a to the B but of course YX to + + + align:start position:0% +equal to a to the B but of course YX to +the 0 is nothing but Y and what we + + align:start position:0% +the 0 is nothing but Y and what we + + + align:start position:0% +the 0 is nothing but Y and what we +conclude is that sure enough this + + align:start position:0% +conclude is that sure enough this + + + align:start position:0% +conclude is that sure enough this +machine leaves the desired exponential + + align:start position:0% +machine leaves the desired exponential + + + align:start position:0% +machine leaves the desired exponential +value in the register Y which is where + + align:start position:0% +value in the register Y which is where + + + align:start position:0% +value in the register Y which is where +we get the answer and that's why this + + align:start position:0% +we get the answer and that's why this + + + align:start position:0% +we get the answer and that's why this +algorithm is + + align:start position:0% +algorithm is + + + align:start position:0% +algorithm is +correct uh now another aspect of uh of + + align:start position:0% +correct uh now another aspect of uh of + + + align:start position:0% +correct uh now another aspect of uh of +what's going on here uh is proving that + + align:start position:0% +what's going on here uh is proving that + + + align:start position:0% +what's going on here uh is proving that +the algorithm does terminate so let me + + align:start position:0% +the algorithm does terminate so let me + + + align:start position:0% +the algorithm does terminate so let me +just say a word that Floyd uh + + align:start position:0% +just say a word that Floyd uh + + + align:start position:0% +just say a word that Floyd uh +distinguished sort of these two aspects + + align:start position:0% +distinguished sort of these two aspects + + + align:start position:0% +distinguished sort of these two aspects +of program correctness that typically + + align:start position:0% +of program correctness that typically + + + align:start position:0% +of program correctness that typically +come up one is showing that if you get + + align:start position:0% +come up one is showing that if you get + + + align:start position:0% +come up one is showing that if you get +an answer it's correct and that's what + + align:start position:0% +an answer it's correct and that's what + + + align:start position:0% +an answer it's correct and that's what +we just did if this machine stops if it + + align:start position:0% +we just did if this machine stops if it + + + align:start position:0% +we just did if this machine stops if it +ever gets to the case where Z is zero + + align:start position:0% +ever gets to the case where Z is zero + + + align:start position:0% +ever gets to the case where Z is zero +then y has the right answer but we + + align:start position:0% +then y has the right answer but we + + + align:start position:0% +then y has the right answer but we +haven't proved that it stops so we've + + align:start position:0% +haven't proved that it stops so we've + + + align:start position:0% +haven't proved that it stops so we've +shown that it's partially correct like a + + align:start position:0% +shown that it's partially correct like a + + + align:start position:0% +shown that it's partially correct like a +partial function uh it might not be + + align:start position:0% +partial function uh it might not be + + + align:start position:0% +partial function uh it might not be +defined everywhere we haven't shown that + + align:start position:0% +defined everywhere we haven't shown that + + + align:start position:0% +defined everywhere we haven't shown that +yet but when it is defined it gives the + + align:start position:0% +yet but when it is defined it gives the + + + align:start position:0% +yet but when it is defined it gives the +right answer then the other aspect of + + align:start position:0% +right answer then the other aspect of + + + align:start position:0% +right answer then the other aspect of +correctness is termination showing in + + align:start position:0% +correctness is termination showing in + + + align:start position:0% +correctness is termination showing in +effect that the function is total that + + align:start position:0% +effect that the function is total that + + + align:start position:0% +effect that the function is total that +the program always does stop well in + + align:start position:0% +the program always does stop well in + + + align:start position:0% +the program always does stop well in +this case there's an easy way to see why + + align:start position:0% +this case there's an easy way to see why + + + align:start position:0% +this case there's an easy way to see why +it always stops because at every + + align:start position:0% +it always stops because at every + + + align:start position:0% +it always stops because at every +transition um Z is being haved or more Z + + align:start position:0% +transition um Z is being haved or more Z + + + align:start position:0% +transition um Z is being haved or more Z +is a uh a non- negative integer valued + + align:start position:0% +is a uh a non- negative integer valued + + + align:start position:0% +is a uh a non- negative integer valued +variable and uh since we're having it or + + align:start position:0% +variable and uh since we're having it or + + + align:start position:0% +variable and uh since we're having it or +Mak it even smaller than half of it at + + align:start position:0% +Mak it even smaller than half of it at + + + align:start position:0% +Mak it even smaller than half of it at +every step it means that since it starts + + align:start position:0% +every step it means that since it starts + + + align:start position:0% +every step it means that since it starts +with the value z uh it can't get smaller + + align:start position:0% +with the value z uh it can't get smaller + + + align:start position:0% +with the value z uh it can't get smaller +more than log to the base 2 of B times + + align:start position:0% +more than log to the base 2 of B times + + + align:start position:0% +more than log to the base 2 of B times +because by then it would have hit zero + + align:start position:0% +because by then it would have hit zero + + + align:start position:0% +because by then it would have hit zero +and so we can be sure that this machine + + align:start position:0% +and so we can be sure that this machine + + + align:start position:0% +and so we can be sure that this machine +makes it most log to the base two of B + + align:start position:0% +makes it most log to the base two of B + + + align:start position:0% +makes it most log to the base two of B +transitions uh and then it has to get + + align:start position:0% +transitions uh and then it has to get + + + align:start position:0% +transitions uh and then it has to get +stuck at the only place that it can + + align:start position:0% +stuck at the only place that it can + + + align:start position:0% +stuck at the only place that it can +stuck which is when Z equals zero um and + + align:start position:0% +stuck which is when Z equals zero um and + + + align:start position:0% +stuck which is when Z equals zero um and +there is a picture of my uh uh friend + + align:start position:0% +there is a picture of my uh uh friend + + + align:start position:0% +there is a picture of my uh uh friend +and early colleague Bob Floyd uh whom I + + align:start position:0% +and early colleague Bob Floyd uh whom I + + + align:start position:0% +and early colleague Bob Floyd uh whom I +met at the very beginning of my career + + align:start position:0% +met at the very beginning of my career + + + align:start position:0% +met at the very beginning of my career +at uh Carnegie melon University we + + align:start position:0% +at uh Carnegie melon University we + + + align:start position:0% +at uh Carnegie melon University we +worked together for about one year + + align:start position:0% +worked together for about one year + + + align:start position:0% +worked together for about one year +before he went off to Stanford and you + + align:start position:0% +before he went off to Stanford and you + + + align:start position:0% +before he went off to Stanford and you +can read uh much more about his life in + + align:start position:0% +can read uh much more about his life in + + + align:start position:0% +can read uh much more about his life in +a a warm and in and and detailed eulogy + + align:start position:0% +a a warm and in and and detailed eulogy + + + align:start position:0% +a a warm and in and and detailed eulogy +written by his best friend Don kth uh + + align:start position:0% +written by his best friend Don kth uh + + + align:start position:0% +written by his best friend Don kth uh +Floyd won the touring award uh for his + + align:start position:0% +Floyd won the touring award uh for his + + + align:start position:0% +Floyd won the touring award uh for his +major contributions both to program + + align:start position:0% +major contributions both to program + + + align:start position:0% +major contributions both to program +correctness and to programming language + + align:start position:0% +correctness and to programming language + + + align:start position:0% +correctness and to programming language +parsing \ No newline at end of file diff --git a/WCCpss6udNs.txt b/WCCpss6udNs.txt new file mode 100644 index 0000000000000000000000000000000000000000..ab6853180ede1c57afc15a49fa96a55577e2a766 --- /dev/null +++ b/WCCpss6udNs.txt @@ -0,0 +1,9691 @@ +align:start position:0% + +So last time + + align:start position:0% +So last time + + + align:start position:0% +So last time +uh last time we talked about the basic + + align:start position:0% +uh last time we talked about the basic + + + align:start position:0% +uh last time we talked about the basic +algebraic operation for limit of + + align:start position:0% +algebraic operation for limit of + + + align:start position:0% +algebraic operation for limit of +sequences. We talked about the mono + + align:start position:0% +sequences. We talked about the mono + + + align:start position:0% +sequences. We talked about the mono +convergence theorem. So the mono + + align:start position:0% +convergence theorem. So the mono + + + align:start position:0% +convergence theorem. So the mono +convergence theorem was that you had a + + align:start position:0% +convergence theorem was that you had a + + + align:start position:0% +convergence theorem was that you had a +sequence + + align:start position:0% +sequence + + + align:start position:0% +sequence +that was increasing or it could be + + align:start position:0% +that was increasing or it could be + + + align:start position:0% +that was increasing or it could be +decreasing. So either it was increasing + + align:start position:0% +decreasing. So either it was increasing + + + align:start position:0% +decreasing. So either it was increasing +this meant that the next element was + + align:start position:0% +this meant that the next element was + + + align:start position:0% +this meant that the next element was +bigger equal to the previous and then + + align:start position:0% +bigger equal to the previous and then + + + align:start position:0% +bigger equal to the previous and then +they were all assumed to be bounded. + + align:start position:0% +they were all assumed to be bounded. + + + align:start position:0% +they were all assumed to be bounded. +If you had such a sequence or similarly + + align:start position:0% +If you had such a sequence or similarly + + + align:start position:0% +If you had such a sequence or similarly +if you had a sequence so this was the + + align:start position:0% +if you had a sequence so this was the + + + align:start position:0% +if you had a sequence so this was the +increasing case + + align:start position:0% + + + + align:start position:0% + +then there was a similar decreasing case + + align:start position:0% +then there was a similar decreasing case + + + align:start position:0% +then there was a similar decreasing case +where the the the + + align:start position:0% +where the the the + + + align:start position:0% +where the the the +previous is bigger equal to the next one + + align:start position:0% +previous is bigger equal to the next one + + + align:start position:0% +previous is bigger equal to the next one +and then they are assumed to be bounded + + align:start position:0% +and then they are assumed to be bounded + + + align:start position:0% +and then they are assumed to be bounded +from below. + + align:start position:0% +from below. + + + align:start position:0% +from below. +So this was decreasing. + + align:start position:0% +So this was decreasing. + + + align:start position:0% +So this was decreasing. +So monotum convergent theorem was that + + align:start position:0% +So monotum convergent theorem was that + + + align:start position:0% +So monotum convergent theorem was that +if you had a bounded increasing sequence + + align:start position:0% +if you had a bounded increasing sequence + + + align:start position:0% +if you had a bounded increasing sequence +or a bounded decreasing sequence in + + align:start position:0% +or a bounded decreasing sequence in + + + align:start position:0% +or a bounded decreasing sequence in +either case + + align:start position:0% +either case + + + align:start position:0% +either case +uh uh the sequence is convergent + + align:start position:0% +uh uh the sequence is convergent + + + align:start position:0% +uh uh the sequence is convergent +and it's converging in the first case in + + align:start position:0% +and it's converging in the first case in + + + align:start position:0% +and it's converging in the first case in +this case here a + + align:start position:0% + + + + align:start position:0% + +um it's converg to the soup + + align:start position:0% +um it's converg to the soup + + + align:start position:0% +um it's converg to the soup +of the xm to the in case Okay. + + align:start position:0% + + + + align:start position:0% + +And in the case B it converts to the in + + align:start position:0% + + + + align:start position:0% + +case case B. So that was the mono + + align:start position:0% +case case B. So that was the mono + + + align:start position:0% +case case B. So that was the mono +convergence theorem. + + align:start position:0% +convergence theorem. + + + align:start position:0% +convergence theorem. +And the third thing we talk about and + + align:start position:0% +And the third thing we talk about and + + + align:start position:0% +And the third thing we talk about and +that's where we will continue today is + + align:start position:0% +that's where we will continue today is + + + align:start position:0% +that's where we will continue today is +uh is cruise sequence. So we talked + + align:start position:0% +uh is cruise sequence. So we talked + + + align:start position:0% +uh is cruise sequence. So we talked +about push sequence. + + align:start position:0% +about push sequence. + + + align:start position:0% +about push sequence. +So let me and we prove a few things + + align:start position:0% +So let me and we prove a few things + + + align:start position:0% +So let me and we prove a few things +about cruise sequence but we want to + + align:start position:0% +about cruise sequence but we want to + + + align:start position:0% +about cruise sequence but we want to +examine that all today. So let me remind + + align:start position:0% +examine that all today. So let me remind + + + align:start position:0% +examine that all today. So let me remind +you what a cruise sequence is. So a + + align:start position:0% +you what a cruise sequence is. So a + + + align:start position:0% +you what a cruise sequence is. So a +sequence + + align:start position:0% + + + + align:start position:0% + +is said to be + + align:start position:0% + + + + align:start position:0% + +Uh if for all epsilon greater than zero + + align:start position:0% +Uh if for all epsilon greater than zero + + + align:start position:0% +Uh if for all epsilon greater than zero +there exist + + align:start position:0% + + + + align:start position:0% + +there exist n such that + + align:start position:0% + + + + align:start position:0% + +if little n is bigger equal to the + + align:start position:0% +if little n is bigger equal to the + + + align:start position:0% +if little n is bigger equal to the +capital n then Um sorry if little n and + + align:start position:0% +capital n then Um sorry if little n and + + + align:start position:0% +capital n then Um sorry if little n and +little m. + + align:start position:0% +little m. + + + align:start position:0% +little m. +So if n and m m and n are big or equal + + align:start position:0% +So if n and m m and n are big or equal + + + align:start position:0% +So if n and m m and n are big or equal +then they are + + align:start position:0% +then they are + + + align:start position:0% +then they are +epsilon close together + + align:start position:0% +epsilon close together + + + align:start position:0% +epsilon close together +xn + + align:start position:0% +xn + + + align:start position:0% +xn +and x m the distance between them. + + align:start position:0% +and x m the distance between them. + + + align:start position:0% +and x m the distance between them. +So this was a cus sequence and it just + + align:start position:0% +So this was a cus sequence and it just + + + align:start position:0% +So this was a cus sequence and it just +meant quis sequence just meant that the + + align:start position:0% +meant quis sequence just meant that the + + + align:start position:0% +meant quis sequence just meant that the +tail right of the sequence bunchs + + align:start position:0% +tail right of the sequence bunchs + + + align:start position:0% +tail right of the sequence bunchs +together. + + align:start position:0% + + + + align:start position:0% + +Now, uh, let me just prove I think we + + align:start position:0% +Now, uh, let me just prove I think we + + + align:start position:0% +Now, uh, let me just prove I think we +maybe talk about this, but let me but + + align:start position:0% +maybe talk about this, but let me but + + + align:start position:0% +maybe talk about this, but let me but +I'm going to let me + + align:start position:0% +I'm going to let me + + + align:start position:0% +I'm going to let me +just a little theorem here. + + align:start position:0% + + + + align:start position:0% + +Um if + + align:start position:0% +Um if + + + align:start position:0% +Um if +if uh xn + + align:start position:0% +if uh xn + + + align:start position:0% +if uh xn +is a cruci sequence + + align:start position:0% + + + + align:start position:0% + +then uh xn is bounded + + align:start position:0% + + + + align:start position:0% + +and so the proof of this is a proof. + + align:start position:0% + + + + align:start position:0% + +So now in the definition of it being a + + align:start position:0% +So now in the definition of it being a + + + align:start position:0% +So now in the definition of it being a +frequency you can take epsilon to be + + align:start position:0% +frequency you can take epsilon to be + + + align:start position:0% +frequency you can take epsilon to be +equal to one. So if you take take + + align:start position:0% +equal to one. So if you take take + + + align:start position:0% +equal to one. So if you take take +epsilon equal to 1 + + align:start position:0% + + + + align:start position:0% + +in the definition + + align:start position:0% + + + + align:start position:0% + +of being + + align:start position:0% +of being + + + align:start position:0% +of being +accuracy sequence. + + align:start position:0% + + + + align:start position:0% + +So this means that there exist there + + align:start position:0% +So this means that there exist there + + + align:start position:0% +So this means that there exist there +exist + + align:start position:0% + + + + align:start position:0% + +there exist some n + + align:start position:0% +there exist some n + + + align:start position:0% +there exist some n +such that + + align:start position:0% + + + + align:start position:0% + +uh if little n and little m are bigger + + align:start position:0% +uh if little n and little m are bigger + + + align:start position:0% +uh if little n and little m are bigger +than this n then the difference between + + align:start position:0% +than this n then the difference between + + + align:start position:0% +than this n then the difference between +these two + + align:start position:0% +these two + + + align:start position:0% +these two +is less than one. Right? This is the + + align:start position:0% +is less than one. Right? This is the + + + align:start position:0% +is less than one. Right? This is the +definition where I just apply it to + + align:start position:0% +definition where I just apply it to + + + align:start position:0% +definition where I just apply it to +epsilon equal to one. We have this but + + align:start position:0% +epsilon equal to one. We have this but + + + align:start position:0% +epsilon equal to one. We have this but +of course in particular + + align:start position:0% + + + + align:start position:0% + +in particular we can set say m equal to + + align:start position:0% +in particular we can set say m equal to + + + align:start position:0% +in particular we can set say m equal to +this + + align:start position:0% + + + + align:start position:0% + +and then you have that x all the other + + align:start position:0% +and then you have that x all the other + + + align:start position:0% +and then you have that x all the other +ones. This means that for all + + align:start position:0% +ones. This means that for all + + + align:start position:0% +ones. This means that for all +then for all + + align:start position:0% +then for all + + + align:start position:0% +then for all +um little n bigger than capital n if + + align:start position:0% +um little n bigger than capital n if + + + align:start position:0% +um little n bigger than capital n if +you're looking at this + + align:start position:0% +you're looking at this + + + align:start position:0% +you're looking at this +difference here then this is less than + + align:start position:0% +difference here then this is less than + + + align:start position:0% +difference here then this is less than +one I'm only applying this now I'm just + + align:start position:0% +one I'm only applying this now I'm just + + + align:start position:0% +one I'm only applying this now I'm just +choosing just one single m and I'm + + align:start position:0% +choosing just one single m and I'm + + + align:start position:0% +choosing just one single m and I'm +choosing it to be equal to that capital + + align:start position:0% +choosing it to be equal to that capital + + + align:start position:0% +choosing it to be equal to that capital +so you have that And so this means that + + align:start position:0% +so you have that And so this means that + + + align:start position:0% +so you have that And so this means that +that now you see that if you take now so + + align:start position:0% +that now you see that if you take now so + + + align:start position:0% +that now you see that if you take now so +so if you take + + align:start position:0% +so if you take + + + align:start position:0% +so if you take +uh x so now suppose that little n + + align:start position:0% +uh x so now suppose that little n + + + align:start position:0% +uh x so now suppose that little n +so so for + + align:start position:0% +so so for + + + align:start position:0% +so so for +little n bigger than capital n if you if + + align:start position:0% +little n bigger than capital n if you if + + + align:start position:0% +little n bigger than capital n if you if +you look at little n + + align:start position:0% +you look at little n + + + align:start position:0% +you look at little n +then you have this + + align:start position:0% +then you have this + + + align:start position:0% +then you have this +so or + + align:start position:0% +so or + + + align:start position:0% +so or +for or little n big or equal to capital + + align:start position:0% +for or little n big or equal to capital + + + align:start position:0% +for or little n big or equal to capital +n. Then you have that the norm of little + + align:start position:0% +n. Then you have that the norm of little + + + align:start position:0% +n. Then you have that the norm of little +n. Well, you can write little n as as um + + align:start position:0% +n. Well, you can write little n as as um + + + align:start position:0% +n. Well, you can write little n as as um +as a difference. + + align:start position:0% +as a difference. + + + align:start position:0% +as a difference. +You can write little n + + align:start position:0% +You can write little n + + + align:start position:0% +You can write little n +like you can subtract it first and then + + align:start position:0% +like you can subtract it first and then + + + align:start position:0% +like you can subtract it first and then +add it again. So this is clearly the + + align:start position:0% +add it again. So this is clearly the + + + align:start position:0% +add it again. So this is clearly the +same. + + align:start position:0% +same. + + + align:start position:0% +same. +And now you can just + + align:start position:0% +And now you can just + + + align:start position:0% +And now you can just +So you have the sum of two things. You + + align:start position:0% +So you have the sum of two things. You + + + align:start position:0% +So you have the sum of two things. You +can think about this in here as one + + align:start position:0% +can think about this in here as one + + + align:start position:0% +can think about this in here as one +number and this is another number. So + + align:start position:0% +number and this is another number. So + + + align:start position:0% +number and this is another number. So +this is now less than x n minus x + + align:start position:0% +this is now less than x n minus x + + + align:start position:0% +this is now less than x n minus x +capital n plus the norm of x capital n. + + align:start position:0% + + + + align:start position:0% + +And this here was because little n was + + align:start position:0% +And this here was because little n was + + + align:start position:0% +And this here was because little n was +bigger than capital n. This here is + + align:start position:0% +bigger than capital n. This here is + + + align:start position:0% +bigger than capital n. This here is +bounded by one. So this is less than one + + align:start position:0% +bounded by one. So this is less than one + + + align:start position:0% +bounded by one. So this is less than one +plus the norm. + + align:start position:0% +plus the norm. + + + align:start position:0% +plus the norm. +this. + + align:start position:0% +this. + + + align:start position:0% +this. +So you see that for all the the little + + align:start position:0% +So you see that for all the the little + + + align:start position:0% +So you see that for all the the little +ends that are bigger than capture all of + + align:start position:0% +ends that are bigger than capture all of + + + align:start position:0% +ends that are bigger than capture all of +those there is a uniform arch right and + + align:start position:0% +those there is a uniform arch right and + + + align:start position:0% +those there is a uniform arch right and +so this means that if you're now just + + align:start position:0% +so this means that if you're now just + + + align:start position:0% +so this means that if you're now just +taking them the maximum + + align:start position:0% +taking them the maximum + + + align:start position:0% +taking them the maximum +of uh the norm of x1 the norm of x2 + + align:start position:0% +of uh the norm of x1 the norm of x2 + + + align:start position:0% +of uh the norm of x1 the norm of x2 +up to the norm of xn + + align:start position:0% +up to the norm of xn + + + align:start position:0% +up to the norm of xn +uh minus uh sorry xn minus one + + align:start position:0% +uh minus uh sorry xn minus one + + + align:start position:0% +uh minus uh sorry xn minus one +and then x capital n + + align:start position:0% +and then x capital n + + + align:start position:0% +and then x capital n ++ one. If you take the maximum of this + + align:start position:0% ++ one. If you take the maximum of this + + + align:start position:0% ++ one. If you take the maximum of this +and call this m then clearly for all n + + align:start position:0% +and call this m then clearly for all n + + + align:start position:0% +and call this m then clearly for all n +for all n + + align:start position:0% + + + + align:start position:0% + +clearly you have for all n + + align:start position:0% + + + + align:start position:0% + +you have that x n is lesser equal to n + + align:start position:0% +you have that x n is lesser equal to n + + + align:start position:0% +you have that x n is lesser equal to n +right because if n little n is bigger + + align:start position:0% +right because if n little n is bigger + + + align:start position:0% +right because if n little n is bigger +than capital n then it's bounded by + + align:start position:0% +than capital n then it's bounded by + + + align:start position:0% +than capital n then it's bounded by +capital M because it's it's a maximum in + + align:start position:0% +capital M because it's it's a maximum in + + + align:start position:0% +capital M because it's it's a maximum in +particular of this and on the other one + + align:start position:0% +particular of this and on the other one + + + align:start position:0% +particular of this and on the other one +that's sort of obvious. + + align:start position:0% +that's sort of obvious. + + + align:start position:0% +that's sort of obvious. +Okay. So so it means that if you have a + + align:start position:0% +Okay. So so it means that if you have a + + + align:start position:0% +Okay. So so it means that if you have a +cushy sequence it's automatically + + align:start position:0% +cushy sequence it's automatically + + + align:start position:0% +cushy sequence it's automatically +bounded. Okay. + + align:start position:0% +bounded. Okay. + + + align:start position:0% +bounded. Okay. +Now we have the + + align:start position:0% +Now we have the + + + align:start position:0% +Now we have the +convergence theorem. So next we want to + + align:start position:0% +convergence theorem. So next we want to + + + align:start position:0% +convergence theorem. So next we want to +discuss + + align:start position:0% +discuss + + + align:start position:0% +discuss +is + + align:start position:0% + + + + align:start position:0% + +convergence. + + align:start position:0% + + + + align:start position:0% + +So this is the following that uh any + + align:start position:0% +So this is the following that uh any + + + align:start position:0% +So this is the following that uh any +any precision principle + + align:start position:0% + + + + align:start position:0% + +is convergent. + + align:start position:0% + + + + align:start position:0% + +Okay. So remember that last time we + + align:start position:0% +Okay. So remember that last time we + + + align:start position:0% +Okay. So remember that last time we +proved the following. So so recall + + align:start position:0% + + + + align:start position:0% + +that last time + + align:start position:0% + + + + align:start position:0% + +we showed the converse + + align:start position:0% + + + + align:start position:0% + +So namely we prove the following + + align:start position:0% +So namely we prove the following + + + align:start position:0% +So namely we prove the following +theorem. + + align:start position:0% + + + + align:start position:0% + +to prove that if + + align:start position:0% +to prove that if + + + align:start position:0% +to prove that if +that any + + align:start position:0% +that any + + + align:start position:0% +that any +convergent sequence + + align:start position:0% + + + + align:start position:0% + +is a cushy sequence + + align:start position:0% + + + + align:start position:0% + +and so the cushy convergence theorem is + + align:start position:0% +and so the cushy convergence theorem is + + + align:start position:0% +and so the cushy convergence theorem is +to + + align:start position:0% +to + + + align:start position:0% +to +Now uh so we'll come back to the proof + + align:start position:0% +Now uh so we'll come back to the proof + + + align:start position:0% +Now uh so we'll come back to the proof +in just a little bit + + align:start position:0% +in just a little bit + + + align:start position:0% +in just a little bit +but before that let me talk about some + + align:start position:0% +but before that let me talk about some + + + align:start position:0% +but before that let me talk about some +applications + + align:start position:0% + + + + align:start position:0% + +and so the first one we we sort of + + align:start position:0% +and so the first one we we sort of + + + align:start position:0% +and so the first one we we sort of +started talking a little bit um last + + align:start position:0% +started talking a little bit um last + + + align:start position:0% +started talking a little bit um last +time and this is uh the contracting + + align:start position:0% +time and this is uh the contracting + + + align:start position:0% +time and this is uh the contracting +mapping the so contracting And that in + + align:start position:0% +mapping the so contracting And that in + + + align:start position:0% +mapping the so contracting And that in +itself have a number of applications. So + + align:start position:0% +itself have a number of applications. So + + + align:start position:0% +itself have a number of applications. So +contracting + + align:start position:0% + + + + align:start position:0% + +mic + + align:start position:0% + + + + align:start position:0% + +and for that I need some I need to uh + + align:start position:0% +and for that I need some I need to uh + + + align:start position:0% +and for that I need some I need to uh +call some definitions. + + align:start position:0% +call some definitions. + + + align:start position:0% +call some definitions. +So, + + align:start position:0% +So, + + + align:start position:0% +So, +so a map + + align:start position:0% + + + + align:start position:0% + +a map t from r e to r + + align:start position:0% +a map t from r e to r + + + align:start position:0% +a map t from r e to r +uh is set to be + + align:start position:0% + + + + align:start position:0% + +a contracting map. + + align:start position:0% + + + + align:start position:0% + +If there exist + + align:start position:0% + + + + align:start position:0% + +some constant C positive C is positive + + align:start position:0% +some constant C positive C is positive + + + align:start position:0% +some constant C positive C is positive +and the key point is it's it will have + + align:start position:0% +and the key point is it's it will have + + + align:start position:0% +and the key point is it's it will have +to be positive. So that but the key + + align:start position:0% +to be positive. So that but the key + + + align:start position:0% +to be positive. So that but the key +point is that this constant has to be + + align:start position:0% +point is that this constant has to be + + + align:start position:0% +point is that this constant has to be +strictly less than one. And then + + align:start position:0% +strictly less than one. And then + + + align:start position:0% +strictly less than one. And then +contracting mapping just means that if + + align:start position:0% +contracting mapping just means that if + + + align:start position:0% +contracting mapping just means that if +you looking at the difference + + align:start position:0% +you looking at the difference + + + align:start position:0% +you looking at the difference +between the images + + align:start position:0% +between the images + + + align:start position:0% +between the images +then they are closer together. This + + align:start position:0% +then they are closer together. This + + + align:start position:0% +then they are closer together. This +they're strictly closer together + + align:start position:0% +they're strictly closer together + + + align:start position:0% +they're strictly closer together +than than the points that they are + + align:start position:0% +than than the points that they are + + + align:start position:0% +than than the points that they are +images of. + + align:start position:0% +images of. + + + align:start position:0% +images of. +Okay. So this is a contracting map + + align:start position:0% +Okay. So this is a contracting map + + + align:start position:0% +Okay. So this is a contracting map +right then. So the contracting mapping + + align:start position:0% +right then. So the contracting mapping + + + align:start position:0% +right then. So the contracting mapping +again this here inequality is it say + + align:start position:0% +again this here inequality is it say + + + align:start position:0% +again this here inequality is it say +that under the map the images are + + align:start position:0% +that under the map the images are + + + align:start position:0% +that under the map the images are +squeezed more together. + + align:start position:0% +squeezed more together. + + + align:start position:0% +squeezed more together. +So now + + align:start position:0% +So now + + + align:start position:0% +So now +that's one concept. The other one we + + align:start position:0% +that's one concept. The other one we + + + align:start position:0% +that's one concept. The other one we +need is that for fixed points. + + align:start position:0% + + + + align:start position:0% + +So the other concept is fixed point. + + align:start position:0% + + + + align:start position:0% + +So So X here is a fixed point. + + align:start position:0% + + + + align:start position:0% + +for MF. + + align:start position:0% + + + + align:start position:0% + +See if if it is + + align:start position:0% +See if if it is + + + align:start position:0% +See if if it is +if under the map the the points uh + + align:start position:0% +if under the map the the points uh + + + align:start position:0% +if under the map the the points uh +remain unchanged. So T of X is equal to + + align:start position:0% +remain unchanged. So T of X is equal to + + + align:start position:0% +remain unchanged. So T of X is equal to +X. So this is what it needs to be. Yeah. + + align:start position:0% +X. So this is what it needs to be. Yeah. + + + align:start position:0% +X. So this is what it needs to be. Yeah. +>> But that it's not the same C for X and + + align:start position:0% +>> But that it's not the same C for X and + + + align:start position:0% +>> But that it's not the same C for X and +Y. It is the same scene. It is. + + align:start position:0% +Y. It is the same scene. It is. + + + align:start position:0% +Y. It is the same scene. It is. +>> Yeah, it's the same scene. + + align:start position:0% +>> Yeah, it's the same scene. + + + align:start position:0% +>> Yeah, it's the same scene. +>> And we'll come back to this in just a + + align:start position:0% +>> And we'll come back to this in just a + + + align:start position:0% +>> And we'll come back to this in just a +second, but but it but it it is supposed + + align:start position:0% +second, but but it but it it is supposed + + + align:start position:0% +second, but but it but it it is supposed +to be the same scene. + + align:start position:0% +to be the same scene. + + + align:start position:0% +to be the same scene. +You can weaken that a little bit. Uh but + + align:start position:0% +You can weaken that a little bit. Uh but + + + align:start position:0% +You can weaken that a little bit. Uh but +essentially, I mean, you sort of, you + + align:start position:0% +essentially, I mean, you sort of, you + + + align:start position:0% +essentially, I mean, you sort of, you +know, at least we'll talk about this in + + align:start position:0% +know, at least we'll talk about this in + + + align:start position:0% +know, at least we'll talk about this in +just a second, but it it's important + + align:start position:0% +just a second, but it it's important + + + align:start position:0% +just a second, but it it's important +just think about it that it's a + + align:start position:0% +just think about it that it's a + + + align:start position:0% +just think about it that it's a +requirement that it's the same seat for + + align:start position:0% +requirement that it's the same seat for + + + align:start position:0% +requirement that it's the same seat for +all. And the key point is that this C is + + align:start position:0% +all. And the key point is that this C is + + + align:start position:0% +all. And the key point is that this C is +strictly less than one. Okay. So this is + + align:start position:0% +strictly less than one. Okay. So this is + + + align:start position:0% +strictly less than one. Okay. So this is +a fixed point. + + align:start position:0% + + + + align:start position:0% + +And now um so now the first + + align:start position:0% +And now um so now the first + + + align:start position:0% +And now um so now the first +little + + align:start position:0% + + + + align:start position:0% + +that. + + align:start position:0% + + + + align:start position:0% + +So we have a lema here. + + align:start position:0% + + + + align:start position:0% + +Uh if t + + align:start position:0% + + + + align:start position:0% + +uh is a contracting + + align:start position:0% + + + + align:start position:0% + +then + + align:start position:0% +then + + + align:start position:0% +then +then um there's at most + + align:start position:0% + + + + align:start position:0% + +at most one + + align:start position:0% + + + + align:start position:0% + +there cannot be more than one fix. Okay. + + align:start position:0% +there cannot be more than one fix. Okay. + + + align:start position:0% +there cannot be more than one fix. Okay. +So let's prove that. a pro. + + align:start position:0% + + + + align:start position:0% + +So yeah, so I'm going to So suppose + + align:start position:0% + + + + align:start position:0% + +X and Y are fixed points + + align:start position:0% + + + + align:start position:0% + +and I want to show + + align:start position:0% +and I want to show + + + align:start position:0% +and I want to show +that X is equal to Y. + + align:start position:0% +that X is equal to Y. + + + align:start position:0% +that X is equal to Y. +So I'm looking at the + + align:start position:0% +So I'm looking at the + + + align:start position:0% +So I'm looking at the +images. + + align:start position:0% +images. + + + align:start position:0% +images. +So + + align:start position:0% +So + + + align:start position:0% +So +uh + + align:start position:0% + + + + align:start position:0% + +Let's continue. + + align:start position:0% + + + + align:start position:0% + +So I'm looking at the images under F. So + + align:start position:0% +So I'm looking at the images under F. So + + + align:start position:0% +So I'm looking at the images under F. So +I'm looking at So I take T of X + + align:start position:0% +I'm looking at So I take T of X + + + align:start position:0% +I'm looking at So I take T of X +and I'm looking at the difference + + align:start position:0% +and I'm looking at the difference + + + align:start position:0% +and I'm looking at the difference +between T of X and T of Y + + align:start position:0% +between T of X and T of Y + + + align:start position:0% +between T of X and T of Y +and I want to estimate that difference. + + align:start position:0% +and I want to estimate that difference. + + + align:start position:0% +and I want to estimate that difference. +Well, on one hand T X is supposed to be + + align:start position:0% +Well, on one hand T X is supposed to be + + + align:start position:0% +Well, on one hand T X is supposed to be +a fixed point. So T of X is the same as + + align:start position:0% +a fixed point. So T of X is the same as + + + align:start position:0% +a fixed point. So T of X is the same as +X and likewise for Y. So this here is + + align:start position:0% +X and likewise for Y. So this here is + + + align:start position:0% +X and likewise for Y. So this here is +the same. So T of X is the same as X. T + + align:start position:0% +the same. So T of X is the same as X. T + + + align:start position:0% +the same. So T of X is the same as X. T +Y is supposed to be the same as Y. So I + + align:start position:0% +Y is supposed to be the same as Y. So I + + + align:start position:0% +Y is supposed to be the same as Y. So I +have this. On the other hand, it's a + + align:start position:0% +have this. On the other hand, it's a + + + align:start position:0% +have this. On the other hand, it's a +contracting map. So this here is less or + + align:start position:0% +contracting map. So this here is less or + + + align:start position:0% +contracting map. So this here is less or +equal to C + + align:start position:0% +equal to C + + + align:start position:0% +equal to C +times the norm of X - Y. + + align:start position:0% +times the norm of X - Y. + + + align:start position:0% +times the norm of X - Y. +Right? But now C here remember C is + + align:start position:0% +Right? But now C here remember C is + + + align:start position:0% +Right? But now C here remember C is +strictly less than one. + + align:start position:0% +strictly less than one. + + + align:start position:0% +strictly less than one. +So you can only have an inequality like + + align:start position:0% +So you can only have an inequality like + + + align:start position:0% +So you can only have an inequality like +this, right? If this number here is + + align:start position:0% +this, right? If this number here is + + + align:start position:0% +this, right? If this number here is +zero, right? when c is strictly less + + align:start position:0% +zero, right? when c is strictly less + + + align:start position:0% +zero, right? when c is strictly less +than one. So this here implies that x - + + align:start position:0% +than one. So this here implies that x - + + + align:start position:0% +than one. So this here implies that x - +y + + align:start position:0% +y + + + align:start position:0% +y +the distance is zero and so of course + + align:start position:0% +the distance is zero and so of course + + + align:start position:0% +the distance is zero and so of course +this means that x is equal to y. + + align:start position:0% +this means that x is equal to y. + + + align:start position:0% +this means that x is equal to y. +>> Okay. So that's what we want to prove. + + align:start position:0% +>> Okay. So that's what we want to prove. + + + align:start position:0% +>> Okay. So that's what we want to prove. +Yeah. + + align:start position:0% + + + + align:start position:0% + +>> Yeah. I'm sorry that was uh yeah it + + align:start position:0% +>> Yeah. I'm sorry that was uh yeah it + + + align:start position:0% +>> Yeah. I'm sorry that was uh yeah it +should + + align:start position:0% +should + + + align:start position:0% +should +because otherwise you know it's it + + align:start position:0% +because otherwise you know it's it + + + align:start position:0% +because otherwise you know it's it +wouldn't be if x is equal to y would be + + align:start position:0% +wouldn't be if x is equal to y would be + + + align:start position:0% +wouldn't be if x is equal to y would be +so should be let's change + + align:start position:0% + + + + align:start position:0% + +okay so a contracting map have at most + + align:start position:0% +okay so a contracting map have at most + + + align:start position:0% +okay so a contracting map have at most +one fix one + + align:start position:0% +one fix one + + + align:start position:0% +one fix one +okay now let's + + align:start position:0% +okay now let's + + + align:start position:0% +okay now let's +uh so so so let me Just so you're going + + align:start position:0% +uh so so so let me Just so you're going + + + align:start position:0% +uh so so so let me Just so you're going +to do this. So um + + align:start position:0% +to do this. So um + + + align:start position:0% +to do this. So um +um I have harassed the graders to give + + align:start position:0% +um I have harassed the graders to give + + + align:start position:0% +um I have harassed the graders to give +you back the homework. I uh it should be + + align:start position:0% +you back the homework. I uh it should be + + + align:start position:0% +you back the homework. I uh it should be +back today. I mean otherwise they're in + + align:start position:0% +back today. I mean otherwise they're in + + + align:start position:0% +back today. I mean otherwise they're in +trouble. So hopefully but but but and + + align:start position:0% +trouble. So hopefully but but but and + + + align:start position:0% +trouble. So hopefully but but but and +the assignment for next week is already + + align:start position:0% +the assignment for next week is already + + + align:start position:0% +the assignment for next week is already +posted. + + align:start position:0% +posted. + + + align:start position:0% +posted. +And and here's + + align:start position:0% +And and here's + + + align:start position:0% +And and here's +here's um + + align:start position:0% +here's um + + + align:start position:0% +here's um +so this is on the next so I I will + + align:start position:0% + + + + align:start position:0% + +so here's um here's something on pet + + align:start position:0% +so here's um here's something on pet + + + align:start position:0% +so here's um here's something on pet +stream + + align:start position:0% + + + + align:start position:0% + +and I think it's uh + + align:start position:0% +and I think it's uh + + + align:start position:0% +and I think it's uh +okay uh yeah I forget which one it is + + align:start position:0% +okay uh yeah I forget which one it is + + + align:start position:0% +okay uh yeah I forget which one it is +but anyway on on the third pet + + align:start position:0% +but anyway on on the third pet + + + align:start position:0% +but anyway on on the third pet +You will be asked to prove the following + + align:start position:0% +You will be asked to prove the following + + + align:start position:0% +You will be asked to prove the following +that if uh t here + + align:start position:0% +that if uh t here + + + align:start position:0% +that if uh t here +is a contracting map + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +and x here is any point + + align:start position:0% +and x here is any point + + + align:start position:0% +and x here is any point +any point in the domain of this + + align:start position:0% + + + + align:start position:0% + +Then if you form the sequence a n so a1 + + align:start position:0% +Then if you form the sequence a n so a1 + + + align:start position:0% +Then if you form the sequence a n so a1 +say that's just x + + align:start position:0% +say that's just x + + + align:start position:0% +say that's just x +a2 uh let's let's call it a sorry let's + + align:start position:0% +a2 uh let's let's call it a sorry let's + + + align:start position:0% +a2 uh let's let's call it a sorry let's +let's call it a z is x + + align:start position:0% +let's call it a z is x + + + align:start position:0% +let's call it a z is x +uh a1 here + + align:start position:0% +uh a1 here + + + align:start position:0% +uh a1 here +is t of x t of a is zero so this is t of + + align:start position:0% + + + + align:start position:0% + +and a2 + + align:start position:0% +and a2 + + + align:start position:0% +and a2 +is t of a1. So this is the same as t of + + align:start position:0% +is t of a1. So this is the same as t of + + + align:start position:0% +is t of a1. So this is the same as t of +this. So this is t + + align:start position:0% +this. So this is t + + + align:start position:0% +this. So this is t +* t of x which I'm will write like this + + align:start position:0% + + + + align:start position:0% + +and uh a3 so we continue this way a3 is + + align:start position:0% +and uh a3 so we continue this way a3 is + + + align:start position:0% +and uh a3 so we continue this way a3 is +t of a2. So that is + + align:start position:0% +t of a2. So that is + + + align:start position:0% +t of a2. So that is +t applied three times. So t g + + align:start position:0% +t applied three times. So t g + + + align:start position:0% +t applied three times. So t g +t g t g t g t g t g t g t g t g t g t g + + align:start position:0% +t g t g t g t g t g t g t g t g t g t g + + + align:start position:0% +t g t g t g t g t g t g t g t g t g t g +t g t g t g t g t g t g t g t g t g t g + + align:start position:0% +t g t g t g t g t g t g t g t g t g t g + + + align:start position:0% +t g t g t g t g t g t g t g t g t g t g +of x and I'm going to write this as g c + + align:start position:0% +of x and I'm going to write this as g c + + + align:start position:0% +of x and I'm going to write this as g c +2 of x + + align:start position:0% +2 of x + + + align:start position:0% +2 of x +and and so on. So a n is going to be t + + align:start position:0% +and and so on. So a n is going to be t + + + align:start position:0% +and and so on. So a n is going to be t +of a sorry it's t + + align:start position:0% + + + + align:start position:0% + +a n + one + + align:start position:0% +a n + one + + + align:start position:0% +a n + one +is going to be t of a n. So that's the + + align:start position:0% +is going to be t of a n. So that's the + + + align:start position:0% +is going to be t of a n. So that's the +same as uh t to the power n + one + + align:start position:0% +same as uh t to the power n + one + + + align:start position:0% +same as uh t to the power n + one +of x. + + align:start position:0% +of x. + + + align:start position:0% +of x. +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +So if you have a contracting map and you + + align:start position:0% +So if you have a contracting map and you + + + align:start position:0% +So if you have a contracting map and you +just start with any point you want and + + align:start position:0% +just start with any point you want and + + + align:start position:0% +just start with any point you want and +now you form a sequence that is based on + + align:start position:0% +now you form a sequence that is based on + + + align:start position:0% +now you form a sequence that is based on +that point and uh and the nth element is + + align:start position:0% +that point and uh and the nth element is + + + align:start position:0% +that point and uh and the nth element is +just where you have applied the map n + + align:start position:0% +just where you have applied the map n + + + align:start position:0% +just where you have applied the map n +times to the original point. So if you + + align:start position:0% +times to the original point. So if you + + + align:start position:0% +times to the original point. So if you +form that sequence then you will prove + + align:start position:0% +form that sequence then you will prove + + + align:start position:0% +form that sequence then you will prove +uh you will show + + align:start position:0% +uh you will show + + + align:start position:0% +uh you will show +that uh + + align:start position:0% +that uh + + + align:start position:0% +that uh +in the homework you will show that this + + align:start position:0% +in the homework you will show that this + + + align:start position:0% +in the homework you will show that this +sequence so this set + + align:start position:0% +sequence so this set + + + align:start position:0% +sequence so this set +three and I I will just do a + + align:start position:0% +three and I I will just do a + + + align:start position:0% +three and I I will just do a +special case of it that you will start + + align:start position:0% +special case of it that you will start + + + align:start position:0% +special case of it that you will start +with but we'll just do this now + + align:start position:0% +with but we'll just do this now + + + align:start position:0% +with but we'll just do this now +and then the rest to you to you know I + + align:start position:0% +and then the rest to you to you know I + + + align:start position:0% +and then the rest to you to you know I +leave you for the homework but but on + + align:start position:0% +leave you for the homework but but on + + + align:start position:0% +leave you for the homework but but on +piece of three you prove that this a is + + align:start position:0% +piece of three you prove that this a is + + + align:start position:0% +piece of three you prove that this a is +a secret + + align:start position:0% + + + + align:start position:0% + +and what is the the key starting point + + align:start position:0% + + + + align:start position:0% + +starting point for this + + align:start position:0% +starting point for this + + + align:start position:0% +starting point for this +so now + + align:start position:0% +so now + + + align:start position:0% +so now +because you're there you know you're + + align:start position:0% +because you're there you know you're + + + align:start position:0% +because you're there you know you're +already uh well started on on p three is + + align:start position:0% +already uh well started on on p three is + + + align:start position:0% +already uh well started on on p three is +a key starting point for this is to + + align:start position:0% +a key starting point for this is to + + + align:start position:0% +a key starting point for this is to +prove that it's a cruise sequence so I + + align:start position:0% +prove that it's a cruise sequence so I + + + align:start position:0% +prove that it's a cruise sequence so I +want to estimate + + align:start position:0% +want to estimate + + + align:start position:0% +want to estimate +so this is not enough right I mean I + + align:start position:0% +so this is not enough right I mean I + + + align:start position:0% +so this is not enough right I mean I +need to prove what I need to show is + + align:start position:0% +need to prove what I need to show is + + + align:start position:0% +need to prove what I need to show is +remember I need to prove that when + + align:start position:0% +remember I need to prove that when + + + align:start position:0% +remember I need to prove that when +little m and little m + + align:start position:0% +little m and little m + + + align:start position:0% +little m and little m +are sufficiently large then I want to + + align:start position:0% +are sufficiently large then I want to + + + align:start position:0% +are sufficiently large then I want to +estimate the distance between these two + + align:start position:0% +estimate the distance between these two + + + align:start position:0% +estimate the distance between these two +and show that they're bunched together, + + align:start position:0% +and show that they're bunched together, + + + align:start position:0% +and show that they're bunched together, +right? That's what we need to prove. + + align:start position:0% +right? That's what we need to prove. + + + align:start position:0% +right? That's what we need to prove. +Prove this precision. I I won't quite do + + align:start position:0% +Prove this precision. I I won't quite do + + + align:start position:0% +Prove this precision. I I won't quite do +this, but I do a special case that is a + + align:start position:0% +this, but I do a special case that is a + + + align:start position:0% +this, but I do a special case that is a +key starting point. And that is the + + align:start position:0% +key starting point. And that is the + + + align:start position:0% +key starting point. And that is the +where I'm looking at this thing here. + + align:start position:0% +where I'm looking at this thing here. + + + align:start position:0% +where I'm looking at this thing here. +I'm looking at two consecutive element + + align:start position:0% +I'm looking at two consecutive element + + + align:start position:0% +I'm looking at two consecutive element +in the sequence and I'm estimating the + + align:start position:0% +in the sequence and I'm estimating the + + + align:start position:0% +in the sequence and I'm estimating the +distance. That's not enough to prove + + align:start position:0% +distance. That's not enough to prove + + + align:start position:0% +distance. That's not enough to prove +that C sequence, right? Because I need + + align:start position:0% +that C sequence, right? Because I need + + + align:start position:0% +that C sequence, right? Because I need +to prove that for all n and m + + align:start position:0% +to prove that for all n and m + + + align:start position:0% +to prove that for all n and m +sufficiently large. And I'm just proving + + align:start position:0% +sufficiently large. And I'm just proving + + + align:start position:0% +sufficiently large. And I'm just proving +here that for any ns sufficiently large + + align:start position:0% +here that for any ns sufficiently large + + + align:start position:0% +here that for any ns sufficiently large +if I'm looking at the neighbor then that + + align:start position:0% +if I'm looking at the neighbor then that + + + align:start position:0% +if I'm looking at the neighbor then that +this is very small but but but you can + + align:start position:0% +this is very small but but but you can + + + align:start position:0% +this is very small but but but you can +use the estimates that we will now prove + + align:start position:0% +use the estimates that we will now prove + + + align:start position:0% +use the estimates that we will now prove +to prove that it is in fact a sequence. + + align:start position:0% +to prove that it is in fact a sequence. + + + align:start position:0% +to prove that it is in fact a sequence. +So in order to estimate this right I'm + + align:start position:0% +So in order to estimate this right I'm + + + align:start position:0% +So in order to estimate this right I'm +can think about this thing here + + align:start position:0% +can think about this thing here + + + align:start position:0% +can think about this thing here +as t as a to the n + one this here is + + align:start position:0% +as t as a to the n + one this here is + + + align:start position:0% +as t as a to the n + one this here is +just t of a to n and a n itself this is + + align:start position:0% +just t of a to n and a n itself this is + + + align:start position:0% +just t of a to n and a n itself this is +t of the previous element right this is + + align:start position:0% +t of the previous element right this is + + + align:start position:0% +t of the previous element right this is +how we define them so this means that + + align:start position:0% +how we define them so this means that + + + align:start position:0% +how we define them so this means that +this thing here so again I could just + + align:start position:0% +this thing here so again I could just + + + align:start position:0% +this thing here so again I could just +write this in here. So this thing is + + align:start position:0% +write this in here. So this thing is + + + align:start position:0% +write this in here. So this thing is +equal to a n minus t of a n minus one + + align:start position:0% + + + + align:start position:0% + +and now I can use that contracting map + + align:start position:0% +and now I can use that contracting map + + + align:start position:0% +and now I can use that contracting map +right because now I have these two gez + + align:start position:0% +right because now I have these two gez + + + align:start position:0% +right because now I have these two gez +here so I can use that contracting map + + align:start position:0% +here so I can use that contracting map + + + align:start position:0% +here so I can use that contracting map +so I get less or equal to and then a n + + align:start position:0% +so I get less or equal to and then a n + + + align:start position:0% +so I get less or equal to and then a n +minus a n minus one + + align:start position:0% +minus a n minus one + + + align:start position:0% +minus a n minus one +and so you see that that's the Next the + + align:start position:0% +and so you see that that's the Next the + + + align:start position:0% +and so you see that that's the Next the +distance between the next pair is + + align:start position:0% +distance between the next pair is + + + align:start position:0% +distance between the next pair is +because C is strictly less than one. It + + align:start position:0% +because C is strictly less than one. It + + + align:start position:0% +because C is strictly less than one. It +has decreased with some factor. Right? + + align:start position:0% +has decreased with some factor. Right? + + + align:start position:0% +has decreased with some factor. Right? +And so now the the the key starting + + align:start position:0% +And so now the the the key starting + + + align:start position:0% +And so now the the the key starting +point is that if you just iterate this. + + align:start position:0% + + + + align:start position:0% + +So now if I iterate this, so I'm looking + + align:start position:0% +So now if I iterate this, so I'm looking + + + align:start position:0% +So now if I iterate this, so I'm looking +at a n + 1 minus a n + + align:start position:0% +at a n + 1 minus a n + + + align:start position:0% +at a n + 1 minus a n +and I now have that this thing here is + + align:start position:0% +and I now have that this thing here is + + + align:start position:0% +and I now have that this thing here is +less than c a n minus a n minus one. But + + align:start position:0% +less than c a n minus a n minus one. But + + + align:start position:0% +less than c a n minus a n minus one. But +now I'm writing forget about the c for a + + align:start position:0% +now I'm writing forget about the c for a + + + align:start position:0% +now I'm writing forget about the c for a +second. I'm just writing this thing + + align:start position:0% +second. I'm just writing this thing + + + align:start position:0% +second. I'm just writing this thing +here. So I do the same thing again. I + + align:start position:0% +here. So I do the same thing again. I + + + align:start position:0% +here. So I do the same thing again. I +write this here as the image of a n + + align:start position:0% +write this here as the image of a n + + + align:start position:0% +write this here as the image of a n +minus one and I write this n minus one + + align:start position:0% +minus one and I write this n minus one + + + align:start position:0% +minus one and I write this n minus one +as the image of the previous one. So n + + align:start position:0% +as the image of the previous one. So n + + + align:start position:0% +as the image of the previous one. So n +minus two right and now so I write this + + align:start position:0% +minus two right and now so I write this + + + align:start position:0% +minus two right and now so I write this +so c here I just have to carry along for + + align:start position:0% +so c here I just have to carry along for + + + align:start position:0% +so c here I just have to carry along for +the right and then I have t a n minus + + align:start position:0% +the right and then I have t a n minus + + + align:start position:0% +the right and then I have t a n minus +one minus t a n minus 2. + + align:start position:0% +one minus t a n minus 2. + + + align:start position:0% +one minus t a n minus 2. +And now forget about this just use this + + align:start position:0% +And now forget about this just use this + + + align:start position:0% +And now forget about this just use this +contracting mapping. So then this is + + align:start position:0% +contracting mapping. So then this is + + + align:start position:0% +contracting mapping. So then this is +less than equal to and then the C here I + + align:start position:0% +less than equal to and then the C here I + + + align:start position:0% +less than equal to and then the C here I +to carry along. But then there's another + + align:start position:0% +to carry along. But then there's another + + + align:start position:0% +to carry along. But then there's another +C that pops out. Right? So this is times + + align:start position:0% +C that pops out. Right? So this is times + + + align:start position:0% +C that pops out. Right? So this is times +C that pops out because of the + + align:start position:0% +C that pops out because of the + + + align:start position:0% +C that pops out because of the +contracting mapping and then a N minus + + align:start position:0% +contracting mapping and then a N minus + + + align:start position:0% +contracting mapping and then a N minus +one minus A N minus 2. And so you see + + align:start position:0% +one minus A N minus 2. And so you see + + + align:start position:0% +one minus A N minus 2. And so you see +that you have written this as c^ squ a n + + align:start position:0% +that you have written this as c^ squ a n + + + align:start position:0% +that you have written this as c^ squ a n +minus 2 - one minus a n minus 2. And so + + align:start position:0% +minus 2 - one minus a n minus 2. And so + + + align:start position:0% +minus 2 - one minus a n minus 2. And so +now you continue it and so you see that + + align:start position:0% +now you continue it and so you see that + + + align:start position:0% +now you continue it and so you see that +the further out you get right. So you + + align:start position:0% +the further out you get right. So you + + + align:start position:0% +the further out you get right. So you +continue this all the way down to that + + align:start position:0% +continue this all the way down to that + + + align:start position:0% +continue this all the way down to that +you're getting that this element is the + + align:start position:0% +you're getting that this element is the + + + align:start position:0% +you're getting that this element is the +initial point and and this one is the + + align:start position:0% +initial point and and this one is the + + + align:start position:0% +initial point and and this one is the +first ele you know a1. This is a z and + + align:start position:0% +first ele you know a1. This is a z and + + + align:start position:0% +first ele you know a1. This is a z and +this is a1 right + + align:start position:0% +this is a1 right + + + align:start position:0% +this is a1 right +and so you see that you're getting + + align:start position:0% +and so you see that you're getting + + + align:start position:0% +and so you see that you're getting +something which is like a a c to some + + align:start position:0% +something which is like a a c to some + + + align:start position:0% +something which is like a a c to some +power n times the distance that you + + align:start position:0% +power n times the distance that you + + + align:start position:0% +power n times the distance that you +started with right so this is bounded by + + align:start position:0% +started with right so this is bounded by + + + align:start position:0% +started with right so this is bounded by +uh something like c to the n * a 1 - a z + + align:start position:0% +uh something like c to the n * a 1 - a z + + + align:start position:0% +uh something like c to the n * a 1 - a z +something like that + + align:start position:0% +something like that + + + align:start position:0% +something like that +and so that's a key starting point. So + + align:start position:0% +and so that's a key starting point. So + + + align:start position:0% +and so that's a key starting point. So +if you going very very far out remember + + align:start position:0% +if you going very very far out remember + + + align:start position:0% +if you going very very far out remember +that this number is smaller than one. So + + align:start position:0% +that this number is smaller than one. So + + + align:start position:0% +that this number is smaller than one. So +this here will become incredibly small + + align:start position:0% +this here will become incredibly small + + + align:start position:0% +this here will become incredibly small +when n is large. Right? And so this is + + align:start position:0% +when n is large. Right? And so this is + + + align:start position:0% +when n is large. Right? And so this is +the key starting point uh to prove that + + align:start position:0% +the key starting point uh to prove that + + + align:start position:0% +the key starting point uh to prove that +to prove that if you take a contracting + + align:start position:0% +to prove that if you take a contracting + + + align:start position:0% +to prove that if you take a contracting +map start with any point and you form + + align:start position:0% +map start with any point and you form + + + align:start position:0% +map start with any point and you form +this sequence here then it's a sequence. + + align:start position:0% +this sequence here then it's a sequence. + + + align:start position:0% +this sequence here then it's a sequence. +So now + + align:start position:0% +So now + + + align:start position:0% +So now +so and I leave the rest for the + + align:start position:0% +so and I leave the rest for the + + + align:start position:0% +so and I leave the rest for the +homework. Uh + + align:start position:0% + + + + align:start position:0% + +now let's prove the + + align:start position:0% +now let's prove the + + + align:start position:0% +now let's prove the +contracting mapping theorem + + align:start position:0% +contracting mapping theorem + + + align:start position:0% +contracting mapping theorem +using the cush convergence. + + align:start position:0% + + + + align:start position:0% + +cushion + + align:start position:0% + + + + align:start position:0% + +will not prove the contracting Not going + + align:start position:0% +will not prove the contracting Not going + + + align:start position:0% +will not prove the contracting Not going +to serve. + + align:start position:0% + + + + align:start position:0% + +Okay. So what is a contracting mapping + + align:start position:0% +Okay. So what is a contracting mapping + + + align:start position:0% +Okay. So what is a contracting mapping +theorem? The contracting mapping theorem + + align:start position:0% +theorem? The contracting mapping theorem + + + align:start position:0% +theorem? The contracting mapping theorem +is that if t here is a contracting map. + + align:start position:0% + + + + align:start position:0% + +So T g from R to R + + align:start position:0% + + + + align:start position:0% + +maps R into R gives a contracting map. + + align:start position:0% + + + + align:start position:0% + +Then + + align:start position:0% +Then + + + align:start position:0% +Then +then T has a fixed point. + + align:start position:0% + + + + align:start position:0% + +We already know that such a fixed point + + align:start position:0% +We already know that such a fixed point + + + align:start position:0% +We already know that such a fixed point +is unique, right? We already proved that + + align:start position:0% +is unique, right? We already proved that + + + align:start position:0% +is unique, right? We already proved that +it can at most be one fixed point. + + align:start position:0% +it can at most be one fixed point. + + + align:start position:0% +it can at most be one fixed point. +Okay, so let's try to prove that. So + + align:start position:0% +Okay, so let's try to prove that. So + + + align:start position:0% +Okay, so let's try to prove that. So +we're going to use like this result from + + align:start position:0% +we're going to use like this result from + + + align:start position:0% +we're going to use like this result from +PC. + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +So I start with I start with any point + + align:start position:0% +So I start with I start with any point + + + align:start position:0% +So I start with I start with any point +X. You pick any point you want and then + + align:start position:0% +X. You pick any point you want and then + + + align:start position:0% +X. You pick any point you want and then +we form the sequence + + align:start position:0% +we form the sequence + + + align:start position:0% +we form the sequence +where you apply this uh uh end time to + + align:start position:0% +where you apply this uh uh end time to + + + align:start position:0% +where you apply this uh uh end time to +X. + + align:start position:0% + + + + align:start position:0% + +Now we have that. So, so then we have we + + align:start position:0% +Now we have that. So, so then we have we + + + align:start position:0% +Now we have that. So, so then we have we +have so this is this pie set from P + + align:start position:0% +have so this is this pie set from P + + + align:start position:0% +have so this is this pie set from P +three + + align:start position:0% + + + + align:start position:0% + +that a + + align:start position:0% +that a + + + align:start position:0% +that a +is a sequence. + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +Okay. But then the but then from the + + align:start position:0% +Okay. But then the but then from the + + + align:start position:0% +Okay. But then the but then from the +from Kushik convergence + + align:start position:0% + + + + align:start position:0% + +we have + + align:start position:0% +we have + + + align:start position:0% +we have +that + + align:start position:0% +that + + + align:start position:0% +that +uh we have that am + + align:start position:0% +uh we have that am + + + align:start position:0% +uh we have that am +is converging right that this here is + + align:start position:0% +is converging right that this here is + + + align:start position:0% +is converging right that this here is +this here is a cushy sequence but the + + align:start position:0% +this here is a cushy sequence but the + + + align:start position:0% +this here is a cushy sequence but the +cus convergence I'm saying that any + + align:start position:0% +cus convergence I'm saying that any + + + align:start position:0% +cus convergence I'm saying that any +cushy sequence is actually convergent so + + align:start position:0% +cushy sequence is actually convergent so + + + align:start position:0% +cushy sequence is actually convergent so +this here converts to some a + + align:start position:0% +this here converts to some a + + + align:start position:0% +this here converts to some a +okay and now the idea is that we want to + + align:start position:0% +okay and now the idea is that we want to + + + align:start position:0% +okay and now the idea is that we want to +show so want to show + + align:start position:0% + + + + align:start position:0% + +that + + align:start position:0% +that + + + align:start position:0% +that +a is a fixed + + align:start position:0% + + + + align:start position:0% + +So that's + + align:start position:0% +So that's + + + align:start position:0% +So that's +this is a kind of uh it's a you know + + align:start position:0% +this is a kind of uh it's a you know + + + align:start position:0% +this is a kind of uh it's a you know +it's it's it's the contracting mapping + + align:start position:0% +it's it's it's the contracting mapping + + + align:start position:0% +it's it's it's the contracting mapping +is actually extremely powerful + + align:start position:0% +is actually extremely powerful + + + align:start position:0% +is actually extremely powerful +uh it can be used to again can be used + + align:start position:0% +uh it can be used to again can be used + + + align:start position:0% +uh it can be used to again can be used +to solve + + align:start position:0% +to solve + + + align:start position:0% +to solve +uh you know uh what's called o ordinary + + align:start position:0% +uh you know uh what's called o ordinary + + + align:start position:0% +uh you know uh what's called o ordinary +differential equations. + + align:start position:0% +differential equations. + + + align:start position:0% +differential equations. +And we talk a little bit about that at + + align:start position:0% +And we talk a little bit about that at + + + align:start position:0% +And we talk a little bit about that at +some later point in the class. And but + + align:start position:0% +some later point in the class. And but + + + align:start position:0% +some later point in the class. And but +it can also be used to solve uh PDS + + align:start position:0% +it can also be used to solve uh PDS + + + align:start position:0% +it can also be used to solve uh PDS +which is more complicated partial + + align:start position:0% +which is more complicated partial + + + align:start position:0% +which is more complicated partial +differential equation and in all kind of + + align:start position:0% +differential equation and in all kind of + + + align:start position:0% +differential equation and in all kind of +other areas of math. Um and um + + align:start position:0% +other areas of math. Um and um + + + align:start position:0% +other areas of math. Um and um +okay so now we want to prove that this a + + align:start position:0% +okay so now we want to prove that this a + + + align:start position:0% +okay so now we want to prove that this a +here is a fixed point. + + align:start position:0% + + + + align:start position:0% + +So + + align:start position:0% + + + + align:start position:0% + +I + + align:start position:0% +I + + + align:start position:0% +I +have and and we we will come back in + + align:start position:0% +have and and we we will come back in + + + align:start position:0% +have and and we we will come back in +just a minute we'll through something + + align:start position:0% +just a minute we'll through something + + + align:start position:0% +just a minute we'll through something +um related to this but but let me just + + align:start position:0% +um related to this but but let me just + + + align:start position:0% +um related to this but but let me just +very simple uh so I talking about a n + + align:start position:0% +very simple uh so I talking about a n + + + align:start position:0% +very simple uh so I talking about a n +here I know that it's converted to a I + + align:start position:0% +here I know that it's converted to a I + + + align:start position:0% +here I know that it's converted to a I +then look at the sequence t of a + + align:start position:0% +then look at the sequence t of a + + + align:start position:0% +then look at the sequence t of a +Well, t of a n that was a n was wrong, + + align:start position:0% +Well, t of a n that was a n was wrong, + + + align:start position:0% +Well, t of a n that was a n was wrong, +right? It was just one further out of + + align:start position:0% +right? It was just one further out of + + + align:start position:0% +right? It was just one further out of +the sequence, right? But so since a + + align:start position:0% +the sequence, right? But so since a + + + align:start position:0% +the sequence, right? But so since a +converge, this means of course that + + align:start position:0% +converge, this means of course that + + + align:start position:0% +converge, this means of course that +since + + align:start position:0% +since + + + align:start position:0% +since +since a n converts to a n, this means + + align:start position:0% +since a n converts to a n, this means + + + align:start position:0% +since a n converts to a n, this means +that this here will also converge to a + + align:start position:0% +that this here will also converge to a + + + align:start position:0% +that this here will also converge to a +n. So since this here a n + one as n + + align:start position:0% +n. So since this here a n + one as n + + + align:start position:0% +n. So since this here a n + one as n +become very large for converge to + + align:start position:0% +become very large for converge to + + + align:start position:0% +become very large for converge to +okay + + align:start position:0% +okay + + + align:start position:0% +okay +now + + align:start position:0% +now + + + align:start position:0% +now +if you're looking at t + + align:start position:0% +if you're looking at t + + + align:start position:0% +if you're looking at t +of a n + + align:start position:0% +of a n + + + align:start position:0% +of a n +so you want to estimate now + + align:start position:0% +so you want to estimate now + + + align:start position:0% +so you want to estimate now +uh so what I want to prove is right so + + align:start position:0% +uh so what I want to prove is right so + + + align:start position:0% +uh so what I want to prove is right so +now I'm looking at this distance so I + + align:start position:0% +now I'm looking at this distance so I + + + align:start position:0% +now I'm looking at this distance so I +want to show + + align:start position:0% +want to show + + + align:start position:0% +want to show +So want to show we want to show + + align:start position:0% + + + + align:start position:0% + +that C of A right is equal to A. That's + + align:start position:0% +that C of A right is equal to A. That's + + + align:start position:0% +that C of A right is equal to A. That's +what we want to do. + + align:start position:0% +what we want to do. + + + align:start position:0% +what we want to do. +And so if I'm looking at T of A N, + + align:start position:0% +And so if I'm looking at T of A N, + + + align:start position:0% +And so if I'm looking at T of A N, +right? T of A N, this here was A N + + + align:start position:0% +right? T of A N, this here was A N + + + + align:start position:0% +right? T of A N, this here was A N + +one. And so if I'm looking at t of a n + + align:start position:0% +one. And so if I'm looking at t of a n + + + align:start position:0% +one. And so if I'm looking at t of a n +plus uh a n minus uh t of a + + align:start position:0% +plus uh a n minus uh t of a + + + align:start position:0% +plus uh a n minus uh t of a +right because it is a contracting map + + align:start position:0% +right because it is a contracting map + + + align:start position:0% +right because it is a contracting map +this thing here is bounded is lesser + + align:start position:0% +this thing here is bounded is lesser + + + align:start position:0% +this thing here is bounded is lesser +equal to c a n minus a + + align:start position:0% + + + + align:start position:0% + +and this is also equal to a n + 1 - g of + + align:start position:0% +and this is also equal to a n + 1 - g of + + + align:start position:0% +and this is also equal to a n + 1 - g of +That was just the definition of the a + + + align:start position:0% +That was just the definition of the a + + + + align:start position:0% +That was just the definition of the a + +one. + + align:start position:0% +one. + + + align:start position:0% +one. +So now I have that a m converts to a. So + + align:start position:0% +So now I have that a m converts to a. So + + + align:start position:0% +So now I have that a m converts to a. So +this means that this here converts to + + align:start position:0% +this means that this here converts to + + + align:start position:0% +this means that this here converts to +zero. Right? Since so now since + + align:start position:0% +zero. Right? Since so now since + + + align:start position:0% +zero. Right? Since so now since +a n converts to a then you have that a n + + align:start position:0% +a n converts to a then you have that a n + + + align:start position:0% +a n converts to a then you have that a n +minus a you can think about this as a + + align:start position:0% +minus a you can think about this as a + + + align:start position:0% +minus a you can think about this as a +sequence that converts to zero. + + align:start position:0% +sequence that converts to zero. + + + align:start position:0% +sequence that converts to zero. +But this inequality here say that since + + align:start position:0% +But this inequality here say that since + + + align:start position:0% +But this inequality here say that since +this goes to zero this in here must also + + align:start position:0% +this goes to zero this in here must also + + + align:start position:0% +this goes to zero this in here must also +go to zero. So you see that therefore + + align:start position:0% + + + + align:start position:0% + +a n + one minus t of a + + align:start position:0% +a n + one minus t of a + + + align:start position:0% +a n + one minus t of a +goes to zero. Right? So but this but + + align:start position:0% +goes to zero. Right? So but this but + + + align:start position:0% +goes to zero. Right? So but this but +that this here goes to zero. This just + + align:start position:0% +that this here goes to zero. This just + + + align:start position:0% +that this here goes to zero. This just +means that a n + one this much converge + + align:start position:0% +means that a n + one this much converge + + + align:start position:0% +means that a n + one this much converge +to t of a + + align:start position:0% +to t of a + + + align:start position:0% +to t of a +right. + + align:start position:0% +right. + + + align:start position:0% +right. +But this sequence already converts to a. + + align:start position:0% +But this sequence already converts to a. + + + align:start position:0% +But this sequence already converts to a. +There can only be one limit. Right? So + + align:start position:0% +There can only be one limit. Right? So + + + align:start position:0% +There can only be one limit. Right? So +we already had that a m + one converts + + align:start position:0% +we already had that a m + one converts + + + align:start position:0% +we already had that a m + one converts +to a. But then these two numbers must be + + align:start position:0% +to a. But then these two numbers must be + + + align:start position:0% +to a. But then these two numbers must be +the same. Right? So the conclusion here + + align:start position:0% +the same. Right? So the conclusion here + + + align:start position:0% +the same. Right? So the conclusion here +is that that a must be equal to g of a. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +So from the cus convergence theorem + + align:start position:0% +So from the cus convergence theorem + + + align:start position:0% +So from the cus convergence theorem +then you get the contracting mapping + + align:start position:0% +then you get the contracting mapping + + + align:start position:0% +then you get the contracting mapping +thems + + align:start position:0% +thems + + + align:start position:0% +thems +and and we already proved that there was + + align:start position:0% +and and we already proved that there was + + + align:start position:0% +and and we already proved that there was +you get a fixed point and we already + + align:start position:0% +you get a fixed point and we already + + + align:start position:0% +you get a fixed point and we already +knew that there was at most one fix + + align:start position:0% +knew that there was at most one fix + + + align:start position:0% +knew that there was at most one fix +point + + align:start position:0% +point + + + align:start position:0% +point +and so so and so this is a very powerful + + align:start position:0% +and so so and so this is a very powerful + + + align:start position:0% +and so so and so this is a very powerful +idea because for many things + + align:start position:0% +idea because for many things + + + align:start position:0% +idea because for many things +it's almost impossible to find the + + align:start position:0% +it's almost impossible to find the + + + align:start position:0% +it's almost impossible to find the +actual + + align:start position:0% +actual + + + align:start position:0% +actual +fix point. But what you do is that + + align:start position:0% +fix point. But what you do is that + + + align:start position:0% +fix point. But what you do is that +you're starting with some right. So in + + align:start position:0% +you're starting with some right. So in + + + align:start position:0% +you're starting with some right. So in +this case you just said you pick any X + + align:start position:0% +this case you just said you pick any X + + + align:start position:0% +this case you just said you pick any X +and then you just apply the map enough + + align:start position:0% +and then you just apply the map enough + + + align:start position:0% +and then you just apply the map enough +times. Right? Sometimes you would start + + align:start position:0% +times. Right? Sometimes you would start + + + align:start position:0% +times. Right? Sometimes you would start +with a you can't + + align:start position:0% +with a you can't + + + align:start position:0% +with a you can't +find a fix point but you can find + + align:start position:0% +find a fix point but you can find + + + align:start position:0% +find a fix point but you can find +something pretty close to the fix point + + align:start position:0% +something pretty close to the fix point + + + align:start position:0% +something pretty close to the fix point +and then then you iterate from there on + + align:start position:0% +and then then you iterate from there on + + + align:start position:0% +and then then you iterate from there on +and we'll see we'll see just in a + + align:start position:0% +and we'll see we'll see just in a + + + align:start position:0% +and we'll see we'll see just in a +second. which I already talked about + + align:start position:0% +second. which I already talked about + + + align:start position:0% +second. which I already talked about +that this applied to the existence + + align:start position:0% +that this applied to the existence + + + align:start position:0% +that this applied to the existence +of solutions to OD and to PD. And now + + align:start position:0% +of solutions to OD and to PD. And now + + + align:start position:0% +of solutions to OD and to PD. And now +let me illustrate this last point. + + align:start position:0% +let me illustrate this last point. + + + align:start position:0% +let me illustrate this last point. +Another example and this come backs to + + align:start position:0% +Another example and this come backs to + + + align:start position:0% +Another example and this come backs to +your question uh about you know is this + + align:start position:0% +your question uh about you know is this + + + align:start position:0% +your question uh about you know is this +the same but but do think about it as + + align:start position:0% +the same but but do think about it as + + + align:start position:0% +the same but but do think about it as +being the same for all X and Y. But you + + align:start position:0% +being the same for all X and Y. But you + + + align:start position:0% +being the same for all X and Y. But you +could have some kind of local statement + + align:start position:0% +could have some kind of local statement + + + align:start position:0% +could have some kind of local statement +where it was true for X and Y in some + + align:start position:0% +where it was true for X and Y in some + + + align:start position:0% +where it was true for X and Y in some +small range and that would be enough to + + align:start position:0% +small range and that would be enough to + + + align:start position:0% +small range and that would be enough to +guarantee you a fix point. But but but + + align:start position:0% +guarantee you a fix point. But but but + + + align:start position:0% +guarantee you a fix point. But but but +in general just I mean it's the same in + + align:start position:0% +in general just I mean it's the same in + + + align:start position:0% +in general just I mean it's the same in +the definition it's supposed to be the + + align:start position:0% +the definition it's supposed to be the + + + align:start position:0% +the definition it's supposed to be the +same for all x and y but so let me + + align:start position:0% +same for all x and y but so let me + + + align:start position:0% +same for all x and y but so let me +explain that + + align:start position:0% +explain that + + + align:start position:0% +explain that +in what's called Newton method. + + align:start position:0% + + + + align:start position:0% + +So this is Newton measure + + align:start position:0% + + + + align:start position:0% + +and so the idea is that you have a + + align:start position:0% +and so the idea is that you have a + + + align:start position:0% +and so the idea is that you have a +function you have some function here f + + align:start position:0% +function you have some function here f + + + align:start position:0% +function you have some function here f +maybe it doesn't look like a function + + align:start position:0% +maybe it doesn't look like a function + + + align:start position:0% +maybe it doesn't look like a function +but it's supposed to this is f ofx + + align:start position:0% +but it's supposed to this is f ofx + + + align:start position:0% +but it's supposed to this is f ofx +and you want to find where this or you + + align:start position:0% +and you want to find where this or you + + + align:start position:0% +and you want to find where this or you +want to find points where this function + + align:start position:0% +want to find points where this function + + + align:start position:0% +want to find points where this function +vanishes. Okay. + + align:start position:0% +vanishes. Okay. + + + align:start position:0% +vanishes. Okay. +And so so the method is sort of a + + align:start position:0% +And so so the method is sort of a + + + align:start position:0% +And so so the method is sort of a +numerical method to find such a + + align:start position:0% + + + + align:start position:0% + +you know just you know if if this + + align:start position:0% +you know just you know if if this + + + align:start position:0% +you know just you know if if this +function was very simple like a linear + + align:start position:0% +function was very simple like a linear + + + align:start position:0% +function was very simple like a linear +function or quadratic function then of + + align:start position:0% +function or quadratic function then of + + + align:start position:0% +function or quadratic function then of +course it would be easy to find but + + align:start position:0% +course it would be easy to find but + + + align:start position:0% +course it would be easy to find but +maybe this is a very complicated + + align:start position:0% +maybe this is a very complicated + + + align:start position:0% +maybe this is a very complicated +function and so you wouldn't be you + + align:start position:0% +function and so you wouldn't be you + + + align:start position:0% +function and so you wouldn't be you +wouldn't necessarily be able to say + + align:start position:0% +wouldn't necessarily be able to say + + + align:start position:0% +wouldn't necessarily be able to say +exactly what the point is + + align:start position:0% +exactly what the point is + + + align:start position:0% +exactly what the point is +and so + + align:start position:0% +and so + + + align:start position:0% +and so +the idea is that so Newton method + + align:start position:0% +the idea is that so Newton method + + + align:start position:0% +the idea is that so Newton method +Newton method is that Newton's methods + + align:start position:0% +Newton method is that Newton's methods + + + align:start position:0% +Newton method is that Newton's methods +require that you start with a good guess + + align:start position:0% +require that you start with a good guess + + + align:start position:0% +require that you start with a good guess +and but this is the idea of the Newton + + align:start position:0% +and but this is the idea of the Newton + + + align:start position:0% +and but this is the idea of the Newton +method. + + align:start position:0% +method. + + + align:start position:0% +method. +So here's the idea + + align:start position:0% + + + + align:start position:0% + +that we're looking at a function like + + align:start position:0% +that we're looking at a function like + + + align:start position:0% +that we're looking at a function like +this. I'm going to assume that this is + + align:start position:0% +this. I'm going to assume that this is + + + align:start position:0% +this. I'm going to assume that this is +um that is not zero. So it's actually + + align:start position:0% +um that is not zero. So it's actually + + + align:start position:0% +um that is not zero. So it's actually +monotom is either increasing or + + align:start position:0% +monotom is either increasing or + + + align:start position:0% +monotom is either increasing or +decreasing. + + align:start position:0% + + + + align:start position:0% + +So I I'm assuming that there's nowhere + + align:start position:0% +So I I'm assuming that there's nowhere + + + align:start position:0% +So I I'm assuming that there's nowhere +where the the fractional vanishes. + + align:start position:0% +where the the fractional vanishes. + + + align:start position:0% +where the the fractional vanishes. +And then I defined a map t of x to be + + align:start position:0% +And then I defined a map t of x to be + + + align:start position:0% +And then I defined a map t of x to be +equal to x + + align:start position:0% +equal to x + + + align:start position:0% +equal to x +minus uh f ofx + + align:start position:0% +minus uh f ofx + + + align:start position:0% +minus uh f ofx +frime of x. This seems kind of uh quite + + align:start position:0% +frime of x. This seems kind of uh quite + + + align:start position:0% +frime of x. This seems kind of uh quite +it seems uh yeah seems far away from + + align:start position:0% +it seems uh yeah seems far away from + + + align:start position:0% +it seems uh yeah seems far away from +now. But if you define it like this. + + align:start position:0% + + + + align:start position:0% + +Now let me take the derivative of this. + + align:start position:0% +Now let me take the derivative of this. + + + align:start position:0% +Now let me take the derivative of this. +If I take the derivative of this now + + align:start position:0% +If I take the derivative of this now + + + align:start position:0% +If I take the derivative of this now +then I get that this in here the + + align:start position:0% +then I get that this in here the + + + align:start position:0% +then I get that this in here the +derivative of x that's just one. The + + align:start position:0% +derivative of x that's just one. The + + + align:start position:0% +derivative of x that's just one. The +derivative of this in here + + align:start position:0% +derivative of this in here + + + align:start position:0% +derivative of this in here +um it's the this is a closing. So it's f + + align:start position:0% +um it's the this is a closing. So it's f + + + align:start position:0% +um it's the this is a closing. So it's f +prime + + align:start position:0% +prime + + + align:start position:0% +prime +uh times + + align:start position:0% +uh times + + + align:start position:0% +uh times +my derivative of this time frime and + + align:start position:0% +my derivative of this time frime and + + + align:start position:0% +my derivative of this time frime and +then f prime squ minus + + align:start position:0% +then f prime squ minus + + + align:start position:0% +then f prime squ minus +and then uh f fp prime like that right + + align:start position:0% +and then uh f fp prime like that right + + + align:start position:0% +and then uh f fp prime like that right +that's a quotion for taking + + align:start position:0% + + + + align:start position:0% + +and so you see that you can write this + + align:start position:0% +and so you see that you can write this + + + align:start position:0% +and so you see that you can write this +if you split this up into two this has + + align:start position:0% +if you split this up into two this has + + + align:start position:0% +if you split this up into two this has +one you split it up to two this has + + align:start position:0% +one you split it up to two this has + + + align:start position:0% +one you split it up to two this has +frime + + align:start position:0% +frime + + + align:start position:0% +frime +2 / frime squ and then this here becomes + + align:start position:0% +2 / frime squ and then this here becomes + + + align:start position:0% +2 / frime squ and then this here becomes +plus and then I'm writing it as f f + + align:start position:0% +plus and then I'm writing it as f f + + + align:start position:0% +plus and then I'm writing it as f f +prime + + align:start position:0% +prime + + + align:start position:0% +prime +fr + + align:start position:0% + + + + align:start position:0% + +and so you see that this here cancel + + align:start position:0% +and so you see that this here cancel + + + align:start position:0% +and so you see that this here cancel +with that so these are cancel so you + + align:start position:0% +with that so these are cancel so you + + + align:start position:0% +with that so these are cancel so you +have that the derivative of this map + + align:start position:0% +have that the derivative of this map + + + align:start position:0% +have that the derivative of this map +is just f of x + + align:start position:0% +is just f of x + + + align:start position:0% +is just f of x +uh frime prime of x frime of x² + + align:start position:0% +uh frime prime of x frime of x² + + + align:start position:0% +uh frime prime of x frime of x² +that's the derivative + + align:start position:0% +that's the derivative + + + align:start position:0% +that's the derivative +and now of course + + align:start position:0% + + + + align:start position:0% + +if I'm using the mean magnet + + align:start position:0% + + + + align:start position:0% + +Then I have that uh derivative. + + align:start position:0% + + + + align:start position:0% + +Then I have that t of x minus t of y. By + + align:start position:0% +Then I have that t of x minus t of y. By + + + align:start position:0% +Then I have that t of x minus t of y. By +the mean man theorem say that this thing + + align:start position:0% +the mean man theorem say that this thing + + + align:start position:0% +the mean man theorem say that this thing +here is the derivative + + align:start position:0% + + + + align:start position:0% + +it's actually like wer theorem or + + align:start position:0% +it's actually like wer theorem or + + + align:start position:0% +it's actually like wer theorem or +whatever but but you can also think + + align:start position:0% +whatever but but you can also think + + + align:start position:0% +whatever but but you can also think +about this is the derivative at + + align:start position:0% +about this is the derivative at + + + align:start position:0% +about this is the derivative at +somewhere in between x and y times the + + align:start position:0% +somewhere in between x and y times the + + + align:start position:0% +somewhere in between x and y times the +difference between x and y + + align:start position:0% + + + + align:start position:0% + +so We see that if we already knew. So if + + align:start position:0% +so We see that if we already knew. So if + + + align:start position:0% +so We see that if we already knew. So if +we can show if we knew + + align:start position:0% + + + + align:start position:0% + +that the derivative + + align:start position:0% +that the derivative + + + align:start position:0% +that the derivative +was bounded everywhere was bounded by + + align:start position:0% +was bounded everywhere was bounded by + + + align:start position:0% +was bounded everywhere was bounded by +some C little C that was less than one. + + align:start position:0% +some C little C that was less than one. + + + align:start position:0% +some C little C that was less than one. +If you had that then of course then you + + align:start position:0% +If you had that then of course then you + + + align:start position:0% +If you had that then of course then you +just take absolute value of this. So + + align:start position:0% +just take absolute value of this. So + + + align:start position:0% +just take absolute value of this. So +then you had the t of x minus t of y the + + align:start position:0% +then you had the t of x minus t of y the + + + align:start position:0% +then you had the t of x minus t of y the +absolute value was was equal to t prime + + align:start position:0% +absolute value was was equal to t prime + + + align:start position:0% +absolute value was was equal to t prime +in this intermediate point x - y but in + + align:start position:0% +in this intermediate point x - y but in + + + align:start position:0% +in this intermediate point x - y but in +this intermediate point we're assuming + + align:start position:0% +this intermediate point we're assuming + + + align:start position:0% +this intermediate point we're assuming +that everywhere the derivative is lesser + + align:start position:0% +that everywhere the derivative is lesser + + + align:start position:0% +that everywhere the derivative is lesser +equal to c. So this here is now this is + + align:start position:0% +equal to c. So this here is now this is + + + align:start position:0% +equal to c. So this here is now this is +lesser equal to c. So c x - y and we're + + align:start position:0% +lesser equal to c. So c x - y and we're + + + align:start position:0% +lesser equal to c. So c x - y and we're +assuming that c is strictly less than + + align:start position:0% +assuming that c is strictly less than + + + align:start position:0% +assuming that c is strictly less than +one. So you see that this here if we + + align:start position:0% +one. So you see that this here if we + + + align:start position:0% +one. So you see that this here if we +knew that the derivative of t was + + align:start position:0% +knew that the derivative of t was + + + align:start position:0% +knew that the derivative of t was +strictly less than one everywhere then + + align:start position:0% +strictly less than one everywhere then + + + align:start position:0% +strictly less than one everywhere then +we would know that this map was + + align:start position:0% +we would know that this map was + + + align:start position:0% +we would know that this map was +contracting that. + + align:start position:0% +contracting that. + + + align:start position:0% +contracting that. +Okay. But but of course you know what we + + align:start position:0% +Okay. But but of course you know what we + + + align:start position:0% +Okay. But but of course you know what we +have for the derivative is we have this + + align:start position:0% +have for the derivative is we have this + + + align:start position:0% +have for the derivative is we have this +in here. + + align:start position:0% + + + + align:start position:0% + +And so now but now the idea is that if + + align:start position:0% +And so now but now the idea is that if + + + align:start position:0% +And so now but now the idea is that if +you start with a really good guess + + align:start position:0% + + + + align:start position:0% + +so if you start with a so so the idea is + + align:start position:0% + + + + align:start position:0% + +so so idea + + align:start position:0% +so so idea + + + align:start position:0% +so so idea +the idea of with Newton method + + align:start position:0% +the idea of with Newton method + + + align:start position:0% +the idea of with Newton method +is start with a good this + + align:start position:0% + + + + align:start position:0% + +like this and I'm not going to make that + + align:start position:0% +like this and I'm not going to make that + + + align:start position:0% +like this and I'm not going to make that +too precise. + + align:start position:0% +too precise. + + + align:start position:0% +too precise. +I'm putting it in quotation marks but + + align:start position:0% +I'm putting it in quotation marks but + + + align:start position:0% +I'm putting it in quotation marks but +the idea is that you want to so good + + align:start position:0% +the idea is that you want to so good + + + align:start position:0% +the idea is that you want to so good +guesses remember that what we want is we + + align:start position:0% +guesses remember that what we want is we + + + align:start position:0% +guesses remember that what we want is we +want to find a point we're interested in + + align:start position:0% +want to find a point we're interested in + + + align:start position:0% +want to find a point we're interested in +this point here where this function here + + align:start position:0% +this point here where this function here + + + align:start position:0% +this point here where this function here +we're interested in a point where the + + align:start position:0% +we're interested in a point where the + + + align:start position:0% +we're interested in a point where the +function vanishes right so starting with + + align:start position:0% +function vanishes right so starting with + + + align:start position:0% +function vanishes right so starting with +a good guess means that you're starting + + align:start position:0% +a good guess means that you're starting + + + align:start position:0% +a good guess means that you're starting +you may not start where the function + + align:start position:0% +you may not start where the function + + + align:start position:0% +you may not start where the function +vanishes but you're starting somewhere + + align:start position:0% +vanishes but you're starting somewhere + + + align:start position:0% +vanishes but you're starting somewhere +where where the values is really small, + + align:start position:0% +where where the values is really small, + + + align:start position:0% +where where the values is really small, +right? That would be a good guess, + + align:start position:0% +right? That would be a good guess, + + + align:start position:0% +right? That would be a good guess, +right? + + align:start position:0% +right? + + + align:start position:0% +right? +And so start with a good guess meaning + + align:start position:0% + + + + align:start position:0% + +that f at that point + + align:start position:0% +that f at that point + + + align:start position:0% +that f at that point +is is is small + + align:start position:0% +is is is small + + + align:start position:0% +is is is small +is is very small. + + align:start position:0% +is is very small. + + + align:start position:0% +is is very small. +Now, of course, you're going to ask what + + align:start position:0% +Now, of course, you're going to ask what + + + align:start position:0% +Now, of course, you're going to ask what +do you mean by very small? So very small + + align:start position:0% +do you mean by very small? So very small + + + align:start position:0% +do you mean by very small? So very small +here is going to mean that the value. + + align:start position:0% +here is going to mean that the value. + + + align:start position:0% +here is going to mean that the value. +So so now we have right from this here. + + align:start position:0% +So so now we have right from this here. + + + align:start position:0% +So so now we have right from this here. +So we have that we have that the + + align:start position:0% +So we have that we have that the + + + align:start position:0% +So we have that we have that the +derivative here of this map here + + align:start position:0% +derivative here of this map here + + + align:start position:0% +derivative here of this map here +was equal to these two terms cancel out. + + align:start position:0% +was equal to these two terms cancel out. + + + align:start position:0% +was equal to these two terms cancel out. +So this is f of x f prime of x + + align:start position:0% +So this is f of x f prime of x + + + align:start position:0% +So this is f of x f prime of x +uh frime + + align:start position:0% +uh frime + + + align:start position:0% +uh frime +of x². + + align:start position:0% +of x². + + + align:start position:0% +of x². +So starting with a good guess means that + + align:start position:0% +So starting with a good guess means that + + + align:start position:0% +So starting with a good guess means that +this thing here is really really small + + align:start position:0% +this thing here is really really small + + + align:start position:0% +this thing here is really really small +and in fact I want it to be small + + align:start position:0% +and in fact I want it to be small + + + align:start position:0% +and in fact I want it to be small +compared with this. Right? So if this + + align:start position:0% +compared with this. Right? So if this + + + align:start position:0% +compared with this. Right? So if this +here is really small compared with that + + align:start position:0% +here is really small compared with that + + + align:start position:0% +here is really small compared with that +then I can guarantee that the absolute + + align:start position:0% +then I can guarantee that the absolute + + + align:start position:0% +then I can guarantee that the absolute +value of this is smaller than one. + + align:start position:0% +value of this is smaller than one. + + + align:start position:0% +value of this is smaller than one. +Right? + + align:start position:0% +Right? + + + align:start position:0% +Right? +And so you see that if you start with a + + align:start position:0% +And so you see that if you start with a + + + align:start position:0% +And so you see that if you start with a +really good guess then it would be a + + align:start position:0% +really good guess then it would be a + + + align:start position:0% +really good guess then it would be a +contracting mapping right and then of + + align:start position:0% +contracting mapping right and then of + + + align:start position:0% +contracting mapping right and then of +course you need to prove that so you're + + align:start position:0% +course you need to prove that so you're + + + align:start position:0% +course you need to prove that so you're +forming the sequence right and you need + + align:start position:0% +forming the sequence right and you need + + + align:start position:0% +forming the sequence right and you need +to prove somehow you need to estimate + + align:start position:0% +to prove somehow you need to estimate + + + align:start position:0% +to prove somehow you need to estimate +that you need to be able to say that + + align:start position:0% +that you need to be able to say that + + + align:start position:0% +that you need to be able to say that +that once you form the sequence you you + + align:start position:0% +that once you form the sequence you you + + + align:start position:0% +that once you form the sequence you you +know the next thing that is spitting out + + align:start position:0% +know the next thing that is spitting out + + + align:start position:0% +know the next thing that is spitting out +is also a good guess right so that you + + align:start position:0% +is also a good guess right so that you + + + align:start position:0% +is also a good guess right so that you +stay in this range of good guess, right? + + align:start position:0% +stay in this range of good guess, right? + + + align:start position:0% +stay in this range of good guess, right? +And if it has this property, then it + + align:start position:0% +And if it has this property, then it + + + align:start position:0% +And if it has this property, then it +would be a contracting map and you would + + align:start position:0% +would be a contracting map and you would + + + align:start position:0% +would be a contracting map and you would +guarantee to get a fixed point, right? + + align:start position:0% +guarantee to get a fixed point, right? + + + align:start position:0% +guarantee to get a fixed point, right? +But and but that's all the Newton + + align:start position:0% +But and but that's all the Newton + + + align:start position:0% +But and but that's all the Newton +methods say, right? So you need to kind + + align:start position:0% +methods say, right? So you need to kind + + + align:start position:0% +methods say, right? So you need to kind +of justify why if you start with a good + + align:start position:0% +of justify why if you start with a good + + + align:start position:0% +of justify why if you start with a good +guess, why you keep as you're iterating + + align:start position:0% +guess, why you keep as you're iterating + + + align:start position:0% +guess, why you keep as you're iterating +this process, why you keep in the range + + align:start position:0% +this process, why you keep in the range + + + align:start position:0% +this process, why you keep in the range +of good guesses. + + align:start position:0% +of good guesses. + + + align:start position:0% +of good guesses. +But but but you know the news method + + align:start position:0% +But but but you know the news method + + + align:start position:0% +But but but you know the news method +doesn't doesn't tell you anything about + + align:start position:0% +doesn't doesn't tell you anything about + + + align:start position:0% +doesn't doesn't tell you anything about +that but but but it require that to be a + + align:start position:0% +that but but but it require that to be a + + + align:start position:0% +that but but but it require that to be a +part + + align:start position:0% +part + + + align:start position:0% +part +and so okay so it's a contracting map + + align:start position:0% +and so okay so it's a contracting map + + + align:start position:0% +and so okay so it's a contracting map +this T is a contracting map right if if + + align:start position:0% +this T is a contracting map right if if + + + align:start position:0% +this T is a contracting map right if if +I can start with a good guess and when I + + align:start position:0% +I can start with a good guess and when I + + + align:start position:0% +I can start with a good guess and when I +do this when I form so I start with this + + align:start position:0% +do this when I form so I start with this + + + align:start position:0% +do this when I form so I start with this +good guess and then I'm looking at that + + align:start position:0% +good guess and then I'm looking at that + + + align:start position:0% +good guess and then I'm looking at that +the next thing is this t of x and then I + + align:start position:0% +the next thing is this t of x and then I + + + align:start position:0% +the next thing is this t of x and then I +t^ squ of x + + align:start position:0% +t^ squ of x + + + align:start position:0% +t^ squ of x +right then and I want all of these to + + align:start position:0% +right then and I want all of these to + + + align:start position:0% +right then and I want all of these to +also be good guesses and then I'm saying + + align:start position:0% +also be good guesses and then I'm saying + + + align:start position:0% +also be good guesses and then I'm saying +that as n goes to infinity this here is + + align:start position:0% +that as n goes to infinity this here is + + + align:start position:0% +that as n goes to infinity this here is +cons + + align:start position:0% +cons + + + align:start position:0% +cons +is going to converge to this fixed point + + align:start position:0% +is going to converge to this fixed point + + + align:start position:0% +is going to converge to this fixed point +I guess I called it x well this is the + + align:start position:0% +I guess I called it x well this is the + + + align:start position:0% +I guess I called it x well this is the +fix point + + align:start position:0% +fix point + + + align:start position:0% +fix point +fix point + + align:start position:0% +fix point + + + align:start position:0% +fix point +for for t + + align:start position:0% +for for t + + + align:start position:0% +for for t +Now, + + align:start position:0% +Now, + + + align:start position:0% +Now, +so now we we we started with a function + + align:start position:0% +so now we we we started with a function + + + align:start position:0% +so now we we we started with a function +and what we were interested in, we + + align:start position:0% +and what we were interested in, we + + + align:start position:0% +and what we were interested in, we +wanted to find a root. So, x0 where this + + align:start position:0% +wanted to find a root. So, x0 where this + + + align:start position:0% +wanted to find a root. So, x0 where this +function vanishes, right? And I + + align:start position:0% +function vanishes, right? And I + + + align:start position:0% +function vanishes, right? And I +constructed a contracting map. But now I + + align:start position:0% +constructed a contracting map. But now I + + + align:start position:0% +constructed a contracting map. But now I +need to relate this contracting map or + + align:start position:0% +need to relate this contracting map or + + + align:start position:0% +need to relate this contracting map or +the fixed point for the contracting to + + align:start position:0% +the fixed point for the contracting to + + + align:start position:0% +the fixed point for the contracting to +the original problem. So, what is a + + align:start position:0% +the original problem. So, what is a + + + align:start position:0% +the original problem. So, what is a +fixed point for the contracting map? + + align:start position:0% +fixed point for the contracting map? + + + align:start position:0% +fixed point for the contracting map? +So the map here + + align:start position:0% +So the map here + + + align:start position:0% +So the map here +the map we defined + + align:start position:0% +the map we defined + + + align:start position:0% +the map we defined +was g of x is equal to x - fx + + align:start position:0% +was g of x is equal to x - fx + + + align:start position:0% +was g of x is equal to x - fx +over frime of x + + align:start position:0% +over frime of x + + + align:start position:0% +over frime of x +but a fixed point fixed point. So if x0 + + align:start position:0% +but a fixed point fixed point. So if x0 + + + align:start position:0% +but a fixed point fixed point. So if x0 +is a fixed point + + align:start position:0% +is a fixed point + + + align:start position:0% +is a fixed point +then this means that uh this here is the + + align:start position:0% +then this means that uh this here is the + + + align:start position:0% +then this means that uh this here is the +same as x0 minus f of x0 + + align:start position:0% +same as x0 minus f of x0 + + + align:start position:0% +same as x0 minus f of x0 +frime of x0 + + align:start position:0% +frime of x0 + + + align:start position:0% +frime of x0 +and now you can just write. So therefore + + align:start position:0% +and now you can just write. So therefore + + + align:start position:0% +and now you can just write. So therefore +this implies that f of x0 minus f of x0 + + align:start position:0% +this implies that f of x0 minus f of x0 + + + align:start position:0% +this implies that f of x0 minus f of x0 +over frime of x0 this here you subtract + + align:start position:0% +over frime of x0 this here you subtract + + + align:start position:0% +over frime of x0 this here you subtract +x0 on both sides and this is equal to + + align:start position:0% +x0 on both sides and this is equal to + + + align:start position:0% +x0 on both sides and this is equal to +zero but that of course means that + + align:start position:0% +zero but that of course means that + + + align:start position:0% +zero but that of course means that +denominator must be zero. + + align:start position:0% + + + + align:start position:0% + +So a fixed point is indeed a point where + + align:start position:0% +So a fixed point is indeed a point where + + + align:start position:0% +So a fixed point is indeed a point where +f of x0 + + align:start position:0% +f of x0 + + + align:start position:0% +f of x0 +is equal to zero. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +Now, + + align:start position:0% +Now, + + + align:start position:0% +Now, +um, so now we want to prove the C + + align:start position:0% +um, so now we want to prove the C + + + align:start position:0% +um, so now we want to prove the C +convergence, + + align:start position:0% +convergence, + + + align:start position:0% +convergence, +but we're going to cheat just a little + + align:start position:0% +but we're going to cheat just a little + + + align:start position:0% +but we're going to cheat just a little +bit because we are going to deduce it + + align:start position:0% +bit because we are going to deduce it + + + align:start position:0% +bit because we are going to deduce it +from another theorem that I will prove + + align:start position:0% +from another theorem that I will prove + + + align:start position:0% +from another theorem that I will prove +next time. + + align:start position:0% +next time. + + + align:start position:0% +next time. +So, + + align:start position:0% + + + + align:start position:0% + +so to prove the component + + align:start position:0% + + + + align:start position:0% + +and that's we'll prove next time. + + align:start position:0% + + + + align:start position:0% + +So, what is a bosano? + + align:start position:0% + + + + align:start position:0% + +So the person theorem. So the person + + align:start position:0% +So the person theorem. So the person + + + align:start position:0% +So the person theorem. So the person +theorem says that every bounded sequence + + align:start position:0% + + + + align:start position:0% + +has a convergent + + align:start position:0% + + + + align:start position:0% + +substitution. + + align:start position:0% + + + + align:start position:0% + +So that's a coal is + + align:start position:0% +So that's a coal is + + + align:start position:0% +So that's a coal is +okay. + + align:start position:0% +okay. + + + align:start position:0% +okay. +Now let's try to so I assume this again + + align:start position:0% +Now let's try to so I assume this again + + + align:start position:0% +Now let's try to so I assume this again +I'll prove this next time. So let's but + + align:start position:0% +I'll prove this next time. So let's but + + + align:start position:0% +I'll prove this next time. So let's but +let's + + align:start position:0% +let's + + + align:start position:0% +let's +This is to prove the cush + + align:start position:0% + + + + align:start position:0% + +from the + + align:start position:0% + + + + align:start position:0% + +from the device. I show + + align:start position:0% + + + + align:start position:0% + +kids. + + align:start position:0% + + + + align:start position:0% + +>> That's fall off. + + align:start position:0% + + + + align:start position:0% + +So remember the cushy convergence here + + align:start position:0% +So remember the cushy convergence here + + + align:start position:0% +So remember the cushy convergence here +I'm saying that if you have a C sequence + + align:start position:0% +I'm saying that if you have a C sequence + + + align:start position:0% +I'm saying that if you have a C sequence +then it is converted. So suppose + + align:start position:0% + + + + align:start position:0% + +XN is a C. + + align:start position:0% + + + + align:start position:0% + +Okay, I want to prove that it's + + align:start position:0% +Okay, I want to prove that it's + + + align:start position:0% +Okay, I want to prove that it's +convergent. + + align:start position:0% +convergent. + + + align:start position:0% +convergent. +But I already we already showed we + + align:start position:0% +But I already we already showed we + + + align:start position:0% +But I already we already showed we +already show + + align:start position:0% +already show + + + align:start position:0% +already show +we already proven + + align:start position:0% +we already proven + + + align:start position:0% +we already proven +show that any C sequence + + align:start position:0% + + + + align:start position:0% + +uh any C sequence + + align:start position:0% +uh any C sequence + + + align:start position:0% +uh any C sequence +shown that XN any C sequence is bounded + + align:start position:0% + + + + align:start position:0% + +right this is this earlier. + + align:start position:0% + + + + align:start position:0% + +So now by therefore by the biosium + + align:start position:0% + + + + align:start position:0% + +by the pano biosium + + align:start position:0% + + + + align:start position:0% + +there's a subsequence + + align:start position:0% + + + + align:start position:0% + +a converted subsequence + + align:start position:0% + + + + align:start position:0% + +So there's a converted subsequent x and + + align:start position:0% +So there's a converted subsequent x and + + + align:start position:0% +So there's a converted subsequent x and +k. + + align:start position:0% + + + + align:start position:0% + +So So now + + align:start position:0% + + + + align:start position:0% + +So you have + + align:start position:0% + + + + align:start position:0% + +you have that uh you have that this + + align:start position:0% +you have that uh you have that this + + + align:start position:0% +you have that uh you have that this +subsequence here convert to some x + + align:start position:0% +subsequence here convert to some x + + + align:start position:0% +subsequence here convert to some x +and now I want to show that the original + + align:start position:0% +and now I want to show that the original + + + align:start position:0% +and now I want to show that the original +sequence converts to x. + + align:start position:0% +sequence converts to x. + + + align:start position:0% +sequence converts to x. +So uh so give so since + + align:start position:0% +So uh so give so since + + + align:start position:0% +So uh so give so since +xn is accus + + align:start position:0% + + + + align:start position:0% + +given + + align:start position:0% +given + + + align:start position:0% +given +given uh epsilon greater than zero. + + align:start position:0% +given uh epsilon greater than zero. + + + align:start position:0% +given uh epsilon greater than zero. +There exist + + align:start position:0% + + + + align:start position:0% + +there exist uh capital n. So that so + + align:start position:0% +there exist uh capital n. So that so + + + align:start position:0% +there exist uh capital n. So that so +that if + + align:start position:0% +that if + + + align:start position:0% +that if +m and n are bigger than capital n then + + align:start position:0% +m and n are bigger than capital n then + + + align:start position:0% +m and n are bigger than capital n then +uh x n minus xm + + align:start position:0% +uh x n minus xm + + + align:start position:0% +uh x n minus xm +is less than epsilon + + align:start position:0% +is less than epsilon + + + align:start position:0% +is less than epsilon +using the epsilon + + align:start position:0% +using the epsilon + + + align:start position:0% +using the epsilon +in the definition of being + + align:start position:0% + + + + align:start position:0% + +but now I and this let's call this the + + align:start position:0% +but now I and this let's call this the + + + align:start position:0% +but now I and this let's call this the +exist n let's call it n1 + + align:start position:0% + + + + align:start position:0% + +So now since + + align:start position:0% +So now since + + + align:start position:0% +So now since +x and k + + align:start position:0% +x and k + + + align:start position:0% +x and k +converge + + align:start position:0% +converge + + + align:start position:0% +converge +to x there exist + + align:start position:0% + + + + align:start position:0% + +for that epsilon there exist + + align:start position:0% +for that epsilon there exist + + + align:start position:0% +for that epsilon there exist +uh n2 uh k2 n2. Yeah. So that if uh if k + + align:start position:0% +uh n2 uh k2 n2. Yeah. So that if uh if k + + + align:start position:0% +uh n2 uh k2 n2. Yeah. So that if uh if k +here is bigger than n_sub_2 + + align:start position:0% +here is bigger than n_sub_2 + + + align:start position:0% +here is bigger than n_sub_2 +then uh x n k - x + + align:start position:0% +then uh x n k - x + + + align:start position:0% +then uh x n k - x +is less than ep 2. + + align:start position:0% +is less than ep 2. + + + align:start position:0% +is less than ep 2. +Okay. + + align:start position:0% + + + + align:start position:0% + +So now, + + align:start position:0% +So now, + + + align:start position:0% +So now, +so now you just take, so now we take um + + align:start position:0% +so now you just take, so now we take um + + + align:start position:0% +so now you just take, so now we take um +we take um n to be equal to + + align:start position:0% +we take um n to be equal to + + + align:start position:0% +we take um n to be equal to +um the maximum + + align:start position:0% +um the maximum + + + align:start position:0% +um the maximum +of uh n1 + + align:start position:0% +of uh n1 + + + align:start position:0% +of uh n1 +and n sorry and n + + align:start position:0% +and n sorry and n + + + align:start position:0% +and n sorry and n +two. This is the one that corresponds to + + align:start position:0% +two. This is the one that corresponds to + + + align:start position:0% +two. This is the one that corresponds to +right. So this is where where k is + + align:start position:0% +right. So this is where where k is + + + align:start position:0% +right. So this is where where k is +taking equal to this n2. + + align:start position:0% + + + + align:start position:0% + +So if we take n like that and you're + + align:start position:0% +So if we take n like that and you're + + + align:start position:0% +So if we take n like that and you're +looking at uh n bigger equal to n and + + align:start position:0% +looking at uh n bigger equal to n and + + + align:start position:0% +looking at uh n bigger equal to n and +you now want to estimate this thing here + + align:start position:0% +you now want to estimate this thing here + + + align:start position:0% +you now want to estimate this thing here +then you can think about this difference + + align:start position:0% +then you can think about this difference + + + align:start position:0% +then you can think about this difference +here as x - x n2 + + align:start position:0% +here as x - x n2 + + + align:start position:0% +here as x - x n2 +plus + + align:start position:0% +plus + + + align:start position:0% +plus +uh sorry x n + + align:start position:0% +uh sorry x n + + + align:start position:0% +uh sorry x n +like this minus plus uh x + + align:start position:0% +like this minus plus uh x + + + align:start position:0% +like this minus plus uh x +x n + + align:start position:0% +x n + + + align:start position:0% +x n +uh x uh x n - uh x + + align:start position:0% +uh x uh x n - uh x + + + align:start position:0% +uh x uh x n - uh x +uh n / x terms like like that + + align:start position:0% + + + + align:start position:0% + +and this here is now in this. So this is + + align:start position:0% +and this here is now in this. So this is + + + align:start position:0% +and this here is now in this. So this is +now in this uh subsequence and so one of + + align:start position:0% +now in this uh subsequence and so one of + + + align:start position:0% +now in this uh subsequence and so one of +them this is less than epsilon / two and + + align:start position:0% +them this is less than epsilon / two and + + + align:start position:0% +them this is less than epsilon / two and +this here is less than epsilon / two and + + align:start position:0% +this here is less than epsilon / two and + + + align:start position:0% +this here is less than epsilon / two and +so you get that this difference here was + + align:start position:0% +so you get that this difference here was + + + align:start position:0% +so you get that this difference here was +less than epilon. Okay + + align:start position:0% + + + + align:start position:0% + +now so this is why the balsano vastra + + align:start position:0% +now so this is why the balsano vastra + + + align:start position:0% +now so this is why the balsano vastra +theorem implies a cush convergence. + + align:start position:0% + + + + align:start position:0% + +Okay. So now the next thing is that I + + align:start position:0% +Okay. So now the next thing is that I + + + align:start position:0% +Okay. So now the next thing is that I +want to give another + + align:start position:0% +want to give another + + + align:start position:0% +want to give another +uh application of so of the kus + + align:start position:0% +uh application of so of the kus + + + align:start position:0% +uh application of so of the kus +convergence. So here's another + + align:start position:0% +convergence. So here's another + + + align:start position:0% +convergence. So here's another +application of the cus convergence. + + align:start position:0% + + + + align:start position:0% + +Right. + + align:start position:0% + + + + align:start position:0% + +So one one application was to the + + align:start position:0% +So one one application was to the + + + align:start position:0% +So one one application was to the +contracting mapping theorem. But here's + + align:start position:0% +contracting mapping theorem. But here's + + + align:start position:0% +contracting mapping theorem. But here's +another application of the of the cushy + + align:start position:0% +another application of the of the cushy + + + align:start position:0% +another application of the of the cushy +convergence + + align:start position:0% + + + + align:start position:0% + +theorem. + + align:start position:0% +theorem. + + + align:start position:0% +theorem. +So this is the extreme value theorem. + + align:start position:0% + + + + align:start position:0% + +them. + + align:start position:0% + + + + align:start position:0% + +Now before I I um before I explain that, + + align:start position:0% +Now before I I um before I explain that, + + + align:start position:0% +Now before I I um before I explain that, +let me + + align:start position:0% +let me + + + align:start position:0% +let me +introduce uh this notion of a function + + align:start position:0% +introduce uh this notion of a function + + + align:start position:0% +introduce uh this notion of a function +being continuous + + align:start position:0% +being continuous + + + align:start position:0% +being continuous +in a rigorous way. So what does it mean + + align:start position:0% +in a rigorous way. So what does it mean + + + align:start position:0% +in a rigorous way. So what does it mean +for a function to be continuous? + + align:start position:0% + + + + align:start position:0% + +So a function + + align:start position:0% + + + + align:start position:0% + +f say from r to r it could be a subset + + align:start position:0% +f say from r to r it could be a subset + + + align:start position:0% +f say from r to r it could be a subset +of r + + align:start position:0% +of r + + + align:start position:0% +of r +all of them is set to be continuous + + align:start position:0% + + + + align:start position:0% + +to being continuous + + align:start position:0% + + + + align:start position:0% + +at x0 at some points x0. + + align:start position:0% +at x0 at some points x0. + + + align:start position:0% +at x0 at some points x0. +If + + align:start position:0% +If + + + align:start position:0% +If +for all + + align:start position:0% +for all + + + align:start position:0% +for all +epsilon greater than zero there exist + + align:start position:0% + + + + align:start position:0% + +there exist delta greater than zero such + + align:start position:0% +there exist delta greater than zero such + + + align:start position:0% +there exist delta greater than zero such +that + + align:start position:0% +that + + + align:start position:0% +that +if x minus x0 + + align:start position:0% +if x minus x0 + + + align:start position:0% +if x minus x0 +is smaller than delta then the images + + align:start position:0% +is smaller than delta then the images + + + align:start position:0% +is smaller than delta then the images +are + + align:start position:0% +are + + + align:start position:0% +are +within epsilon. + + align:start position:0% +within epsilon. + + + align:start position:0% +within epsilon. +each other. + + align:start position:0% + + + + align:start position:0% + +So if you think about it, so if you have + + align:start position:0% +So if you think about it, so if you have + + + align:start position:0% +So if you think about it, so if you have +like the function, this is a function + + align:start position:0% +like the function, this is a function + + + align:start position:0% +like the function, this is a function +you you + + align:start position:0% +you you + + + align:start position:0% +you you +to say that it's continuous at some x0 + + align:start position:0% +to say that it's continuous at some x0 + + + align:start position:0% +to say that it's continuous at some x0 +means that if this thing here is this + + align:start position:0% +means that if this thing here is this + + + align:start position:0% +means that if this thing here is this +here is now f of x0. + + align:start position:0% +here is now f of x0. + + + align:start position:0% +here is now f of x0. +If you take a little interval around + + align:start position:0% +If you take a little interval around + + + align:start position:0% +If you take a little interval around +here, this is a epsilon interval around + + align:start position:0% +here, this is a epsilon interval around + + + align:start position:0% +here, this is a epsilon interval around +here. Then there should be some delta + + align:start position:0% +here. Then there should be some delta + + + align:start position:0% +here. Then there should be some delta +interval around here. So that if you're + + align:start position:0% +interval around here. So that if you're + + + align:start position:0% +interval around here. So that if you're +looking at images here, then it will map + + align:start position:0% +looking at images here, then it will map + + + align:start position:0% +looking at images here, then it will map +into here. + + align:start position:0% +into here. + + + align:start position:0% +into here. +Right? That's what it means to be + + align:start position:0% +Right? That's what it means to be + + + align:start position:0% +Right? That's what it means to be +continuous. + + align:start position:0% + + + + align:start position:0% + +Okay? So this is continuous at a point + + align:start position:0% +Okay? So this is continuous at a point + + + align:start position:0% +Okay? So this is continuous at a point +and a function is set to be continuous + + align:start position:0% +and a function is set to be continuous + + + align:start position:0% +and a function is set to be continuous +if it's continuous at all points. + + align:start position:0% + + + + align:start position:0% + +So, + + align:start position:0% + + + + align:start position:0% + +so a function + + align:start position:0% + + + + align:start position:0% + +is set to be continuous. + + align:start position:0% + + + + align:start position:0% + +If it is continuous + + align:start position:0% + + + + align:start position:0% + +at all. + + align:start position:0% + + + + align:start position:0% + +And so now we have a little theorem here + + align:start position:0% +And so now we have a little theorem here + + + align:start position:0% +And so now we have a little theorem here +and this is often useful way of thinking + + align:start position:0% +and this is often useful way of thinking + + + align:start position:0% +and this is often useful way of thinking +about continuity. + + align:start position:0% + + + + align:start position:0% + +So if + + align:start position:0% +So if + + + align:start position:0% +So if +f is continuous. + + align:start position:0% + + + + align:start position:0% + +So let's say f let's just say it doesn't + + align:start position:0% +So let's say f let's just say it doesn't + + + align:start position:0% +So let's say f let's just say it doesn't +need to be all of r. You just have to be + + align:start position:0% +need to be all of r. You just have to be + + + align:start position:0% +need to be all of r. You just have to be +careful that everything that you talk + + align:start position:0% +careful that everything that you talk + + + align:start position:0% +careful that everything that you talk +about is in the domain. But let's just + + align:start position:0% +about is in the domain. But let's just + + + align:start position:0% +about is in the domain. But let's just +say that f is a function from r to r is + + align:start position:0% +say that f is a function from r to r is + + + align:start position:0% +say that f is a function from r to r is +continuous. + + align:start position:0% + + + + align:start position:0% + +So if f is is continuous + + align:start position:0% +So if f is is continuous + + + align:start position:0% +So if f is is continuous +uh and + + align:start position:0% +uh and + + + align:start position:0% +uh and +xn is a sequence that converts to x + + align:start position:0% +xn is a sequence that converts to x + + + align:start position:0% +xn is a sequence that converts to x +then + + align:start position:0% +then + + + align:start position:0% +then +then the images so f of xn this is + + align:start position:0% +then the images so f of xn this is + + + align:start position:0% +then the images so f of xn this is +another sequence those converge to f of + + align:start position:0% +another sequence those converge to f of + + + align:start position:0% +another sequence those converge to f of +x + + align:start position:0% + + + + align:start position:0% + +this is this This is a usual way of + + align:start position:0% +this is this This is a usual way of + + + align:start position:0% +this is this This is a usual way of +thinking about it being continuous. + + align:start position:0% +thinking about it being continuous. + + + align:start position:0% +thinking about it being continuous. +Um, + + align:start position:0% +Um, + + + align:start position:0% +Um, +and so now so now why is this the case? + + align:start position:0% + + + + align:start position:0% + +So, + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% + + + + align:start position:0% + +since + + align:start position:0% +since + + + align:start position:0% +since +f is continuous, + + align:start position:0% + + + + align:start position:0% + +the only leaf that is continuous at is + + align:start position:0% +the only leaf that is continuous at is + + + align:start position:0% +the only leaf that is continuous at is +x. + + align:start position:0% +x. + + + align:start position:0% +x. +So since it continue at x, this means + + align:start position:0% +So since it continue at x, this means + + + align:start position:0% +So since it continue at x, this means +that for all epsilon you're given + + align:start position:0% + + + + align:start position:0% + +Given epsilon greater than zero there + + align:start position:0% +Given epsilon greater than zero there + + + align:start position:0% +Given epsilon greater than zero there +exist + + align:start position:0% + + + + align:start position:0% + +there exist delta greater than zero such + + align:start position:0% +there exist delta greater than zero such + + + align:start position:0% +there exist delta greater than zero such +that + + align:start position:0% +that + + + align:start position:0% +that +if + + align:start position:0% +if + + + align:start position:0% +if +uh x - y + + align:start position:0% +uh x - y + + + align:start position:0% +uh x - y +this is this this x here that you think + + align:start position:0% +this is this this x here that you think + + + align:start position:0% +this is this this x here that you think +about fixed if x if you have another + + align:start position:0% +about fixed if x if you have another + + + align:start position:0% +about fixed if x if you have another +point that is within delta + + align:start position:0% +point that is within delta + + + align:start position:0% +point that is within delta +And uh the images f of x - f of y + + align:start position:0% + + + + align:start position:0% + +this is just that is continuous at that + + align:start position:0% +this is just that is continuous at that + + + align:start position:0% +this is just that is continuous at that +one point x. Okay. + + align:start position:0% +one point x. Okay. + + + align:start position:0% +one point x. Okay. +Now since + + align:start position:0% +Now since + + + align:start position:0% +Now since +since um xn converts to x right since xn + + align:start position:0% +since um xn converts to x right since xn + + + align:start position:0% +since um xn converts to x right since xn +converts to x this means that if you use + + align:start position:0% +converts to x this means that if you use + + + align:start position:0% +converts to x this means that if you use +this delta here in the definition of uh + + align:start position:0% +this delta here in the definition of uh + + + align:start position:0% +this delta here in the definition of uh +convergence then uh there exist + + align:start position:0% +convergence then uh there exist + + + align:start position:0% +convergence then uh there exist +there exist + + align:start position:0% + + + + align:start position:0% + +capital n such that If x if sorry if + + align:start position:0% +capital n such that If x if sorry if + + + align:start position:0% +capital n such that If x if sorry if +little n is bigger than capital n then x + + align:start position:0% +little n is bigger than capital n then x + + + align:start position:0% +little n is bigger than capital n then x +n minus x + + align:start position:0% +n minus x + + + align:start position:0% +n minus x +is less than delta. + + align:start position:0% +is less than delta. + + + align:start position:0% +is less than delta. +But now you see that if little n is + + align:start position:0% +But now you see that if little n is + + + align:start position:0% +But now you see that if little n is +bigger than capital n then these lies + + align:start position:0% +bigger than capital n then these lies + + + align:start position:0% +bigger than capital n then these lies +this close to x. But then this say that + + align:start position:0% +this close to x. But then this say that + + + align:start position:0% +this close to x. But then this say that +the images. So therefore the images + + align:start position:0% + + + + align:start position:0% + +f of xn + + align:start position:0% +f of xn + + + align:start position:0% +f of xn +minus f of x + + align:start position:0% + + + + align:start position:0% + +is less than epsilon. And this was just + + align:start position:0% +is less than epsilon. And this was just + + + align:start position:0% +is less than epsilon. And this was just +as long as little n was bigger than + + align:start position:0% +as long as little n was bigger than + + + align:start position:0% +as long as little n was bigger than +capital n. That's exactly proving that + + align:start position:0% +capital n. That's exactly proving that + + + align:start position:0% +capital n. That's exactly proving that +this sequence converts to that. Right? + + align:start position:0% +this sequence converts to that. Right? + + + align:start position:0% +this sequence converts to that. Right? +So that's okay. + + align:start position:0% + + + + align:start position:0% + +Now let's prove the extreme value. I + + align:start position:0% +Now let's prove the extreme value. I + + + align:start position:0% +Now let's prove the extreme value. I +need to state that first. + + align:start position:0% + + + + align:start position:0% + +And there's two versions + + align:start position:0% +And there's two versions + + + align:start position:0% +And there's two versions +uh of it. + + align:start position:0% +uh of it. + + + align:start position:0% +uh of it. +So extreme guys. + + align:start position:0% + + + + align:start position:0% + +So you take a function f on some + + align:start position:0% +So you take a function f on some + + + align:start position:0% +So you take a function f on some +interval a and b a real number. + + align:start position:0% +interval a and b a real number. + + + align:start position:0% +interval a and b a real number. +They're both included. + + align:start position:0% +They're both included. + + + align:start position:0% +They're both included. +And f here is continuous. + + align:start position:0% + + + + align:start position:0% + +It's continuous at all points. + + align:start position:0% +It's continuous at all points. + + + align:start position:0% +It's continuous at all points. +It needs to be continuous at all points + + align:start position:0% +It needs to be continuous at all points + + + align:start position:0% +It needs to be continuous at all points +and this interval needs to contain the + + align:start position:0% +and this interval needs to contain the + + + align:start position:0% +and this interval needs to contain the +ins. + + align:start position:0% +ins. + + + align:start position:0% +ins. +So if this is continuous then + + align:start position:0% +So if this is continuous then + + + align:start position:0% +So if this is continuous then +the soup of f is achieved + + align:start position:0% + + + + align:start position:0% + +at some + + align:start position:0% +at some + + + align:start position:0% +at some +uh x. + + align:start position:0% + + + + align:start position:0% + +So meaning that soup + + align:start position:0% +So meaning that soup + + + align:start position:0% +So meaning that soup +of f over this interval + + align:start position:0% + + + + align:start position:0% + +is equal to the value + + align:start position:0% +is equal to the value + + + align:start position:0% +is equal to the value +um let's say let's call it x capital m + + align:start position:0% +um let's say let's call it x capital m + + + align:start position:0% +um let's say let's call it x capital m +yeah capital m for max + + align:start position:0% +yeah capital m for max + + + align:start position:0% +yeah capital m for max +at some point in particular the soup is + + align:start position:0% +at some point in particular the soup is + + + align:start position:0% +at some point in particular the soup is +finite right the soup is finite and it's + + align:start position:0% +finite right the soup is finite and it's + + + align:start position:0% +finite right the soup is finite and it's +not really a soup it's a max Right? And + + align:start position:0% +not really a soup it's a max Right? And + + + align:start position:0% +not really a soup it's a max Right? And +so likewise it also said that moreover + + align:start position:0% +so likewise it also said that moreover + + + align:start position:0% +so likewise it also said that moreover +just the same thing and you could in the + + align:start position:0% +just the same thing and you could in the + + + align:start position:0% +just the same thing and you could in the +usual way you could obtain it from this + + align:start position:0% +usual way you could obtain it from this + + + align:start position:0% +usual way you could obtain it from this +by looking at the function minus f if + + align:start position:0% +by looking at the function minus f if + + + align:start position:0% +by looking at the function minus f if +you wanted or you could just prove it + + align:start position:0% +you wanted or you could just prove it + + + align:start position:0% +you wanted or you could just prove it +directly with the same that we're going + + align:start position:0% +directly with the same that we're going + + + align:start position:0% +directly with the same that we're going +to give here. Moreover, uh the in + + align:start position:0% +to give here. Moreover, uh the in + + + align:start position:0% +to give here. Moreover, uh the in +of f over this interval + + align:start position:0% +of f over this interval + + + align:start position:0% +of f over this interval +is equal to the value at some point. So + + align:start position:0% +is equal to the value at some point. So + + + align:start position:0% +is equal to the value at some point. So +it's not, you know, it's not just a in + + align:start position:0% +it's not, you know, it's not just a in + + + align:start position:0% +it's not, you know, it's not just a in +it actually is a minimum where x little + + align:start position:0% +it actually is a minimum where x little + + + align:start position:0% +it actually is a minimum where x little +m is. + + align:start position:0% + + + + align:start position:0% + +And so now let's try to prove that. And + + align:start position:0% +And so now let's try to prove that. And + + + align:start position:0% +And so now let's try to prove that. And +so this is going to use this theorem + + align:start position:0% +so this is going to use this theorem + + + align:start position:0% +so this is going to use this theorem +that we proved this theorem and then + + align:start position:0% +that we proved this theorem and then + + + align:start position:0% +that we proved this theorem and then +it's going to use uh the kushi conver + + align:start position:0% + + + + align:start position:0% + +So um okay so and I'm just going to + + align:start position:0% +So um okay so and I'm just going to + + + align:start position:0% +So um okay so and I'm just going to +prove like just because the two the two + + align:start position:0% +prove like just because the two the two + + + align:start position:0% +prove like just because the two the two +there's two parts to the extreme values + + align:start position:0% +there's two parts to the extreme values + + + align:start position:0% +there's two parts to the extreme values +the this with a soup and that's this + + align:start position:0% +the this with a soup and that's this + + + align:start position:0% +the this with a soup and that's this +with in but the proof uh you know with + + align:start position:0% +with in but the proof uh you know with + + + align:start position:0% +with in but the proof uh you know with +obvious modification + + align:start position:0% +obvious modification + + + align:start position:0% +obvious modification +they're same + + align:start position:0% +they're same + + + align:start position:0% +they're same +okay so I'm just going to focus on the + + align:start position:0% +okay so I'm just going to focus on the + + + align:start position:0% +okay so I'm just going to focus on the +soup. + + align:start position:0% +soup. + + + align:start position:0% +soup. +So, so I so I want to prove so looking + + align:start position:0% +So, so I so I want to prove so looking + + + align:start position:0% +So, so I so I want to prove so looking +at the soup of this function I pro the + + align:start position:0% +at the soup of this function I pro the + + + align:start position:0% +at the soup of this function I pro the +soup could be infinity. Okay. So, + + align:start position:0% +soup could be infinity. Okay. So, + + + align:start position:0% +soup could be infinity. Okay. So, +usually we like soup to be finite but + + align:start position:0% +usually we like soup to be finite but + + + align:start position:0% +usually we like soup to be finite but +let me allow this that if if there is no + + align:start position:0% +let me allow this that if if there is no + + + align:start position:0% +let me allow this that if if there is no +upper bound then I will write infinity. + + align:start position:0% + + + + align:start position:0% + +So in any case I um there exist + + align:start position:0% +So in any case I um there exist + + + align:start position:0% +So in any case I um there exist +there exist + + align:start position:0% + + + + align:start position:0% + +xn + + align:start position:0% +xn + + + align:start position:0% +xn +so that xn + + align:start position:0% +so that xn + + + align:start position:0% +so that xn +so that f there exist a sequence + + align:start position:0% + + + + align:start position:0% + +in this domain here so that the f of xn + + align:start position:0% +in this domain here so that the f of xn + + + align:start position:0% +in this domain here so that the f of xn +converge to this + + align:start position:0% + + + + align:start position:0% + +of + + align:start position:0% +of + + + align:start position:0% +of +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +>> Okay. I'm allowing here and we don't + + align:start position:0% +>> Okay. I'm allowing here and we don't + + + align:start position:0% +>> Okay. I'm allowing here and we don't +usually like this but I allow this here + + align:start position:0% +usually like this but I allow this here + + + align:start position:0% +usually like this but I allow this here +to be infinite. If it's infinite then I + + align:start position:0% +to be infinite. If it's infinite then I + + + align:start position:0% +to be infinite. If it's infinite then I +just mean that there's a sequence where + + align:start position:0% +just mean that there's a sequence where + + + align:start position:0% +just mean that there's a sequence where +the value of these become larger and + + align:start position:0% +the value of these become larger and + + + align:start position:0% +the value of these become larger and +larger than + + align:start position:0% +larger than + + + align:start position:0% +larger than +right. + + align:start position:0% + + + + align:start position:0% + +So I have that but now you see this here + + align:start position:0% +So I have that but now you see this here + + + align:start position:0% +So I have that but now you see this here +is in this range. So this is a bounded + + align:start position:0% +is in this range. So this is a bounded + + + align:start position:0% +is in this range. So this is a bounded +this is a boundary. So note that xn So + + align:start position:0% +this is a boundary. So note that xn So + + + align:start position:0% +this is a boundary. So note that xn So +note + + align:start position:0% +note + + + align:start position:0% +note +that xn is a boundary sequence. + + align:start position:0% + + + + align:start position:0% + +So then I'm using not kushi conversion + + align:start position:0% + + + + align:start position:0% + +but I use the banana vas. So it's a + + align:start position:0% +but I use the banana vas. So it's a + + + align:start position:0% +but I use the banana vas. So it's a +bounded sequence. which I know that they + + align:start position:0% +bounded sequence. which I know that they + + + align:start position:0% +bounded sequence. which I know that they +exist + + align:start position:0% + + + + align:start position:0% + +a convergent + + align:start position:0% + + + + align:start position:0% + +subsequent + + align:start position:0% + + + + align:start position:0% + +it's a good exercise to see that this + + align:start position:0% +it's a good exercise to see that this + + + align:start position:0% +it's a good exercise to see that this +sequence in itself you know you can just + + align:start position:0% +sequence in itself you know you can just + + + align:start position:0% +sequence in itself you know you can just +draw a little picture and you'll + + align:start position:0% +draw a little picture and you'll + + + align:start position:0% +draw a little picture and you'll +convince yourself that it this sequence + + align:start position:0% +convince yourself that it this sequence + + + align:start position:0% +convince yourself that it this sequence +it in itself may not be convergent. But + + align:start position:0% +it in itself may not be convergent. But + + + align:start position:0% +it in itself may not be convergent. But +after you pass to a subsequence, you you + + align:start position:0% +after you pass to a subsequence, you you + + + align:start position:0% +after you pass to a subsequence, you you +can find a converging subsequence. + + align:start position:0% +can find a converging subsequence. + + + align:start position:0% +can find a converging subsequence. +So it converge. So this here converge + + align:start position:0% +So it converge. So this here converge + + + align:start position:0% +So it converge. So this here converge +and it converts to something in this + + align:start position:0% +and it converts to something in this + + + align:start position:0% +and it converts to something in this +interval, right? And that's important. + + align:start position:0% +interval, right? And that's important. + + + align:start position:0% +interval, right? And that's important. +So it converts to some to some x and I + + align:start position:0% +So it converts to some to some x and I + + + align:start position:0% +So it converts to some to some x and I +call this x capital m. + + align:start position:0% +call this x capital m. + + + align:start position:0% +call this x capital m. +Okay. So converging and the key point + + align:start position:0% +Okay. So converging and the key point + + + align:start position:0% +Okay. So converging and the key point +here is that this thing here is lying in + + align:start position:0% +here is that this thing here is lying in + + + align:start position:0% +here is that this thing here is lying in +this interval and and the function is + + align:start position:0% +this interval and and the function is + + + align:start position:0% +this interval and and the function is +defined + + align:start position:0% +defined + + + align:start position:0% +defined +in particular at this point. Right? So + + align:start position:0% +in particular at this point. Right? So + + + align:start position:0% +in particular at this point. Right? So +if this had not included the end point + + align:start position:0% +if this had not included the end point + + + align:start position:0% +if this had not included the end point +it converts to one of the end point but + + align:start position:0% +it converts to one of the end point but + + + align:start position:0% +it converts to one of the end point but +the function would not be defined there. + + align:start position:0% +the function would not be defined there. + + + align:start position:0% +the function would not be defined there. +So you wouldn't be able to conclude the + + align:start position:0% +So you wouldn't be able to conclude the + + + align:start position:0% +So you wouldn't be able to conclude the +extreme direct but anyway. So should we + + align:start position:0% +extreme direct but anyway. So should we + + + align:start position:0% +extreme direct but anyway. So should we +include the end point here? + + align:start position:0% +include the end point here? + + + align:start position:0% +include the end point here? +Then now we have + + align:start position:0% +Then now we have + + + align:start position:0% +Then now we have +now we have that from this theorem that + + align:start position:0% +now we have that from this theorem that + + + align:start position:0% +now we have that from this theorem that +is right here we have that since this + + align:start position:0% +is right here we have that since this + + + align:start position:0% +is right here we have that since this +sequence converts to that we have that + + align:start position:0% +sequence converts to that we have that + + + align:start position:0% +sequence converts to that we have that +the images + + align:start position:0% + + + + align:start position:0% + +converge + + align:start position:0% +converge + + + align:start position:0% +converge +to sorry to the image of + + align:start position:0% +to sorry to the image of + + + align:start position:0% +to sorry to the image of +X capital N right + + align:start position:0% +X capital N right + + + align:start position:0% +X capital N right +but on the other hand this sequence here + + align:start position:0% +but on the other hand this sequence here + + + align:start position:0% +but on the other hand this sequence here +was a subsequence of a sequence that + + align:start position:0% +was a subsequence of a sequence that + + + align:start position:0% +was a subsequence of a sequence that +converts to the soup. Right? But if you + + align:start position:0% +converts to the soup. Right? But if you + + + align:start position:0% +converts to the soup. Right? But if you +take a sequence that converts to + + align:start position:0% +take a sequence that converts to + + + align:start position:0% +take a sequence that converts to +whatever number, then any subsequence + + align:start position:0% +whatever number, then any subsequence + + + align:start position:0% +whatever number, then any subsequence +will convert to the same number. So this + + align:start position:0% +will convert to the same number. So this + + + align:start position:0% +will convert to the same number. So this +here also + + align:start position:0% +here also + + + align:start position:0% +here also +converts to to + + align:start position:0% +converts to to + + + align:start position:0% +converts to to +the soup + + align:start position:0% +the soup + + + align:start position:0% +the soup +to soup. + + align:start position:0% +to soup. + + + align:start position:0% +to soup. +And so this means that these two numbers + + align:start position:0% +And so this means that these two numbers + + + align:start position:0% +And so this means that these two numbers +here must be the same. + + align:start position:0% +here must be the same. + + + align:start position:0% +here must be the same. +And so you should just you know it would + + align:start position:0% +And so you should just you know it would + + + align:start position:0% +And so you should just you know it would +take you just a second to convince + + align:start position:0% +take you just a second to convince + + + align:start position:0% +take you just a second to convince +yourself that everything is fine if you + + align:start position:0% +yourself that everything is fine if you + + + align:start position:0% +yourself that everything is fine if you +know if a I didn't know that the soup + + align:start position:0% +know if a I didn't know that the soup + + + align:start position:0% +know if a I didn't know that the soup +was a finite number but infinite right + + align:start position:0% +was a finite number but infinite right + + + align:start position:0% +was a finite number but infinite right +that it's that is still fine but but + + align:start position:0% +that it's that is still fine but but + + + align:start position:0% +that it's that is still fine but but +it's that should also take a minute to + + align:start position:0% +it's that should also take a minute to + + + align:start position:0% +it's that should also take a minute to +convince yourself about that. So that + + align:start position:0% +convince yourself about that. So that + + + align:start position:0% +convince yourself about that. So that +that proves the extreme value theorem + + align:start position:0% +that proves the extreme value theorem + + + align:start position:0% +that proves the extreme value theorem +right that the if you take a function + + align:start position:0% +right that the if you take a function + + + align:start position:0% +right that the if you take a function +that is continuous + + align:start position:0% +that is continuous + + + align:start position:0% +that is continuous +and defined on an interval where the + + align:start position:0% +and defined on an interval where the + + + align:start position:0% +and defined on an interval where the +interval include both end points then uh + + align:start position:0% +interval include both end points then uh + + + align:start position:0% +interval include both end points then uh +the s the soup is achieved. So the soup + + align:start position:0% +the s the soup is achieved. So the soup + + + align:start position:0% +the s the soup is achieved. So the soup +is really a max and the in by very + + align:start position:0% +is really a max and the in by very + + + align:start position:0% +is really a max and the in by very +similar proof the inom is also achieved + + align:start position:0% +similar proof the inom is also achieved + + + align:start position:0% +similar proof the inom is also achieved +and so both the min and max + + align:start position:0% + + + + align:start position:0% + +Sorry. + + align:start position:0% + + + + align:start position:0% + +>> Okay. So that was the So yeah, that's + + align:start position:0% +>> Okay. So that was the So yeah, that's + + + align:start position:0% +>> Okay. So that was the So yeah, that's +right. So you're saying just so it was + + align:start position:0% +right. So you're saying just so it was + + + align:start position:0% +right. So you're saying just so it was +clear enough that it was a boundary + + align:start position:0% +clear enough that it was a boundary + + + align:start position:0% +clear enough that it was a boundary +sequence because it lying in this + + align:start position:0% +sequence because it lying in this + + + align:start position:0% +sequence because it lying in this +bounded interval, right? So it's a + + align:start position:0% +bounded interval, right? So it's a + + + align:start position:0% +bounded interval, right? So it's a +boundary sequence. Are you asking why + + align:start position:0% +boundary sequence. Are you asking why + + + align:start position:0% +boundary sequence. Are you asking why +such a bound sequence exist? + + align:start position:0% +such a bound sequence exist? + + + align:start position:0% +such a bound sequence exist? +>> So okay. So, so I just so + + align:start position:0% + + + + align:start position:0% + +you have you have this function, + + align:start position:0% + + + + align:start position:0% + +right? So, so like this. So, you you + + align:start position:0% +right? So, so like this. So, you you + + + align:start position:0% +right? So, so like this. So, you you +take the soup of f over this in term + + align:start position:0% +take the soup of f over this in term + + + align:start position:0% +take the soup of f over this in term +and so this means that that if you take + + align:start position:0% +and so this means that that if you take + + + align:start position:0% +and so this means that that if you take +any any epsilon and you subtract it from + + align:start position:0% +any any epsilon and you subtract it from + + + align:start position:0% +any any epsilon and you subtract it from +the two, right? Then actually there must + + align:start position:0% +the two, right? Then actually there must + + + align:start position:0% +the two, right? Then actually there must +exist a x depending on this epsilon + + align:start position:0% +exist a x depending on this epsilon + + + align:start position:0% +exist a x depending on this epsilon +there must exist so that the value at + + align:start position:0% +there must exist so that the value at + + + align:start position:0% +there must exist so that the value at +this x is larger than this right and so + + align:start position:0% +this x is larger than this right and so + + + align:start position:0% +this x is larger than this right and so +you could imagine instead of epsilon + + align:start position:0% +you could imagine instead of epsilon + + + align:start position:0% +you could imagine instead of epsilon +here take looking at a sequence like + + align:start position:0% +here take looking at a sequence like + + + align:start position:0% +here take looking at a sequence like +this and then this gives you a sequence + + align:start position:0% +this and then this gives you a sequence + + + align:start position:0% +this and then this gives you a sequence +like that + + align:start position:0% +like that + + + align:start position:0% +like that +and so right so that would be how and + + align:start position:0% +and so right so that would be how and + + + align:start position:0% +and so right so that would be how and +the same when you do + + align:start position:0% +the same when you do + + + align:start position:0% +the same when you do +and so once you have it it's bound + + align:start position:0% +and so once you have it it's bound + + + align:start position:0% +and so once you have it it's bound +sequence because it's lie between A and + + align:start position:0% +sequence because it's lie between A and + + + align:start position:0% +sequence because it's lie between A and +B, right? You're using the Banana Vest + + align:start position:0% +B, right? You're using the Banana Vest + + + align:start position:0% +B, right? You're using the Banana Vest +theorem that we prove next time to get a + + align:start position:0% +theorem that we prove next time to get a + + + align:start position:0% +theorem that we prove next time to get a +convergent subsequence and then you + + align:start position:0% +convergent subsequence and then you + + + align:start position:0% +convergent subsequence and then you +apply the theorem this theorem here to + + align:start position:0% +apply the theorem this theorem here to + + + align:start position:0% +apply the theorem this theorem here to +get that in that case the maximum and + + align:start position:0% +get that in that case the maximum and + + + align:start position:0% +get that in that case the maximum and +likewise for the minimum that they + + align:start position:0% +likewise for the minimum that they + + + align:start position:0% +likewise for the minimum that they +achieved. + + align:start position:0% +achieved. + + + align:start position:0% +achieved. +Any questions? \ No newline at end of file diff --git a/XWFocLnBdhM.txt b/XWFocLnBdhM.txt new file mode 100644 index 0000000000000000000000000000000000000000..b29c222269be06b62df6110e6639e5815b66f71e --- /dev/null +++ b/XWFocLnBdhM.txt @@ -0,0 +1,795 @@ +align:start position:0% + +earlier in this course we talked about + + align:start position:0% +earlier in this course we talked about + + + align:start position:0% +earlier in this course we talked about +the changing role of labor unions and + + align:start position:0% +the changing role of labor unions and + + + align:start position:0% +the changing role of labor unions and +how the decline in Union membership has + + align:start position:0% +how the decline in Union membership has + + + align:start position:0% +how the decline in Union membership has +contributed to the breakdown of the + + align:start position:0% +contributed to the breakdown of the + + + align:start position:0% +contributed to the breakdown of the +social contract to understand this + + align:start position:0% +social contract to understand this + + + align:start position:0% +social contract to understand this +better let's look at how union + + align:start position:0% +better let's look at how union + + + align:start position:0% +better let's look at how union +membership rates have changed since + + align:start position:0% +membership rates have changed since + + + align:start position:0% +membership rates have changed since +their peak in the 1950s when almost + + align:start position:0% +their peak in the 1950s when almost + + + align:start position:0% +their peak in the 1950s when almost +onethird of all employees belong to a + + align:start position:0% +onethird of all employees belong to a + + + align:start position:0% +onethird of all employees belong to a +union by the early 1980s around the time + + align:start position:0% +union by the early 1980s around the time + + + align:start position:0% +union by the early 1980s around the time +when we begin to see the real effects of + + align:start position:0% +when we begin to see the real effects of + + + align:start position:0% +when we begin to see the real effects of +the breakdown of the social contract + + align:start position:0% +the breakdown of the social contract + + + align:start position:0% +the breakdown of the social contract +union membership was already declining + + align:start position:0% +union membership was already declining + + + align:start position:0% +union membership was already declining +and from then until now it declined even + + align:start position:0% +and from then until now it declined even + + + align:start position:0% +and from then until now it declined even +more dramatically in 2013 only 11% of + + align:start position:0% +more dramatically in 2013 only 11% of + + + align:start position:0% +more dramatically in 2013 only 11% of +129 million working individuals in the + + align:start position:0% +129 million working individuals in the + + + align:start position:0% +129 million working individuals in the +US had a union on a job and collective + + align:start position:0% +US had a union on a job and collective + + + align:start position:0% +US had a union on a job and collective +bargaining at work now in the private + + align:start position:0% +bargaining at work now in the private + + + align:start position:0% +bargaining at work now in the private +sector which employs most working + + align:start position:0% +sector which employs most working + + + align:start position:0% +sector which employs most working +individuals in the US this percentage is + + align:start position:0% +individuals in the US this percentage is + + + align:start position:0% +individuals in the US this percentage is +even lower barely 7% of these workers in + + align:start position:0% +even lower barely 7% of these workers in + + + align:start position:0% +even lower barely 7% of these workers in +fast food health care or technology for + + align:start position:0% +fast food health care or technology for + + + align:start position:0% +fast food health care or technology for +example barely 7% have a union at work + + align:start position:0% +example barely 7% have a union at work + + + align:start position:0% +example barely 7% have a union at work +now labor leaders and Scholars who study + + align:start position:0% +now labor leaders and Scholars who study + + + align:start position:0% +now labor leaders and Scholars who study +employment in labor unions argue that a + + align:start position:0% +employment in labor unions argue that a + + + align:start position:0% +employment in labor unions argue that a +number of factors have contributed to + + align:start position:0% +number of factors have contributed to + + + align:start position:0% +number of factors have contributed to +this decline in unions some argue for + + align:start position:0% +this decline in unions some argue for + + + align:start position:0% +this decline in unions some argue for +example that the structure of the + + align:start position:0% +example that the structure of the + + + align:start position:0% +example that the structure of the +economy plays a role as growth in + + align:start position:0% +economy plays a role as growth in + + + align:start position:0% +economy plays a role as growth in +non-union sectors concentrated in + + align:start position:0% +non-union sectors concentrated in + + + align:start position:0% +non-union sectors concentrated in +service Industries has outstripped + + align:start position:0% +service Industries has outstripped + + + align:start position:0% +service Industries has outstripped +growth in Industries like construction + + align:start position:0% +growth in Industries like construction + + + align:start position:0% +growth in Industries like construction +and Manufacturing where unions + + align:start position:0% +and Manufacturing where unions + + + align:start position:0% +and Manufacturing where unions +historically have been strong others + + align:start position:0% +historically have been strong others + + + align:start position:0% +historically have been strong others +point to the increased difficulty of + + align:start position:0% +point to the increased difficulty of + + + align:start position:0% +point to the increased difficulty of +organizing new membership and in + + align:start position:0% +organizing new membership and in + + + align:start position:0% +organizing new membership and in +particular to the legal obstacles that + + align:start position:0% +particular to the legal obstacles that + + + align:start position:0% +particular to the legal obstacles that +exist in implementing new agreements at + + align:start position:0% +exist in implementing new agreements at + + + align:start position:0% +exist in implementing new agreements at +work Recent research has found that only + + align:start position:0% +work Recent research has found that only + + + align:start position:0% +work Recent research has found that only +one in seven workplaces where workers + + align:start position:0% +one in seven workplaces where workers + + + align:start position:0% +one in seven workplaces where workers +have organized an election and voted for + + align:start position:0% +have organized an election and voted for + + + align:start position:0% +have organized an election and voted for +a union will actually see a contract in + + align:start position:0% +a union will actually see a contract in + + + align:start position:0% +a union will actually see a contract in +the year following their vote and often + + align:start position:0% +the year following their vote and often + + + align:start position:0% +the year following their vote and often +times these types of elections are + + align:start position:0% +times these types of elections are + + + align:start position:0% +times these types of elections are +contentious + + align:start position:0% +contentious + + + align:start position:0% +contentious +and in workplaces where employers have + + align:start position:0% +and in workplaces where employers have + + + align:start position:0% +and in workplaces where employers have +been charged with trying to discourage + + align:start position:0% +been charged with trying to discourage + + + align:start position:0% +been charged with trying to discourage +Union activity through unfair labor + + align:start position:0% +Union activity through unfair labor + + + align:start position:0% +Union activity through unfair labor +practices the odds go down by nearly a + + align:start position:0% +practices the odds go down by nearly a + + + align:start position:0% +practices the odds go down by nearly a +third in addition to these economic and + + align:start position:0% +third in addition to these economic and + + + align:start position:0% +third in addition to these economic and +legal challenges labor leaders and + + align:start position:0% +legal challenges labor leaders and + + + align:start position:0% +legal challenges labor leaders and +Scholars also point to increased + + align:start position:0% +Scholars also point to increased + + + align:start position:0% +Scholars also point to increased +anti-union activity not only by + + align:start position:0% +anti-union activity not only by + + + align:start position:0% +anti-union activity not only by +employers but increasingly by policy + + align:start position:0% +employers but increasingly by policy + + + align:start position:0% +employers but increasingly by policy +makers as we've seen in States like + + align:start position:0% +makers as we've seen in States like + + + align:start position:0% +makers as we've seen in States like +Wisconsin and Indiana or rolling back + + align:start position:0% +Wisconsin and Indiana or rolling back + + + align:start position:0% +Wisconsin and Indiana or rolling back +workers rights to organize and + + align:start position:0% +workers rights to organize and + + + align:start position:0% +workers rights to organize and +collective bargaining agreements so over + + align:start position:0% +collective bargaining agreements so over + + + align:start position:0% +collective bargaining agreements so over +the past three decades there's really + + align:start position:0% +the past three decades there's really + + + align:start position:0% +the past three decades there's really +been a shift not only in how many people + + align:start position:0% +been a shift not only in how many people + + + align:start position:0% +been a shift not only in how many people +experience labor unions on the job but + + align:start position:0% +experience labor unions on the job but + + + align:start position:0% +experience labor unions on the job but +in the way that we think about labor + + align:start position:0% +in the way that we think about labor + + + align:start position:0% +in the way that we think about labor +unions and in this course we've talked + + align:start position:0% +unions and in this course we've talked + + + align:start position:0% +unions and in this course we've talked +about the social contract and what it + + align:start position:0% +about the social contract and what it + + + align:start position:0% +about the social contract and what it +means at work this idea that what's good + + align:start position:0% +means at work this idea that what's good + + + align:start position:0% +means at work this idea that what's good +for workers is good for businesses and + + align:start position:0% +for workers is good for businesses and + + + align:start position:0% +for workers is good for businesses and +although we have examples of many good + + align:start position:0% +although we have examples of many good + + + align:start position:0% +although we have examples of many good +employers as discussed by Professor Zay + + align:start position:0% +employers as discussed by Professor Zay + + + align:start position:0% +employers as discussed by Professor Zay +Upton in her video many employers act as + + align:start position:0% +Upton in her video many employers act as + + + align:start position:0% +Upton in her video many employers act as +though this idea is no longer the case + + align:start position:0% +though this idea is no longer the case + + + align:start position:0% +though this idea is no longer the case +that what's good good for workers is not + + align:start position:0% +that what's good good for workers is not + + + align:start position:0% +that what's good good for workers is not +necessarily good for businesses and that + + align:start position:0% +necessarily good for businesses and that + + + align:start position:0% +necessarily good for businesses and that +unions do not have a role in improving + + align:start position:0% +unions do not have a role in improving + + + align:start position:0% +unions do not have a role in improving +the way that firms work at the same time + + align:start position:0% +the way that firms work at the same time + + + align:start position:0% +the way that firms work at the same time +declining wages less job security and + + align:start position:0% +declining wages less job security and + + + align:start position:0% +declining wages less job security and +increased costs related to things like + + align:start position:0% +increased costs related to things like + + + align:start position:0% +increased costs related to things like +health care and student loans are making + + align:start position:0% +health care and student loans are making + + + align:start position:0% +health care and student loans are making +it more difficult for working + + align:start position:0% +it more difficult for working + + + align:start position:0% +it more difficult for working +individuals all of this adds up to a + + align:start position:0% +individuals all of this adds up to a + + + align:start position:0% +individuals all of this adds up to a +difficult environment not only for labor + + align:start position:0% +difficult environment not only for labor + + + align:start position:0% +difficult environment not only for labor +unions but also for individuals who try + + align:start position:0% +unions but also for individuals who try + + + align:start position:0% +unions but also for individuals who try +to protect their rights on the job the + + align:start position:0% +to protect their rights on the job the + + + align:start position:0% +to protect their rights on the job the +good news however is that over the past + + align:start position:0% +good news however is that over the past + + + align:start position:0% +good news however is that over the past +two decades we've had a flurry of + + align:start position:0% +two decades we've had a flurry of + + + align:start position:0% +two decades we've had a flurry of +activity in organizing around economic + + align:start position:0% +activity in organizing around economic + + + align:start position:0% +activity in organizing around economic +Justice in ways that are bringing + + align:start position:0% +Justice in ways that are bringing + + + align:start position:0% +Justice in ways that are bringing +employees voices front and center these + + align:start position:0% +employees voices front and center these + + + align:start position:0% +employees voices front and center these +include new strategies of labor unions + + align:start position:0% +include new strategies of labor unions + + + align:start position:0% +include new strategies of labor unions +to expand their membership and include + + align:start position:0% +to expand their membership and include + + + align:start position:0% +to expand their membership and include +more working people the growth of worker + + align:start position:0% +more working people the growth of worker + + + align:start position:0% +more working people the growth of worker +centers and labor associations outside + + align:start position:0% +centers and labor associations outside + + + align:start position:0% +centers and labor associations outside +this realm and the strengthening of + + align:start position:0% +this realm and the strengthening of + + + align:start position:0% +this realm and the strengthening of +employment policy through Economic + + align:start position:0% +employment policy through Economic + + + align:start position:0% +employment policy through Economic +Development we've also seen a growing + + align:start position:0% +Development we've also seen a growing + + + align:start position:0% +Development we've also seen a growing +number of social movements that are + + align:start position:0% +number of social movements that are + + + align:start position:0% +number of social movements that are +highlighting the ways in which the + + align:start position:0% +highlighting the ways in which the + + + align:start position:0% +highlighting the ways in which the +social contract can be reestablished at + + align:start position:0% +social contract can be reestablished at + + + align:start position:0% +social contract can be reestablished at +work in the next video we'll talk about + + align:start position:0% +work in the next video we'll talk about + + + align:start position:0% +work in the next video we'll talk about +each of these in a bit more + + align:start position:0% + + + + align:start position:0% + +detail for \ No newline at end of file diff --git a/XsYXACeIklU.txt b/XsYXACeIklU.txt new file mode 100644 index 0000000000000000000000000000000000000000..c1b6e45d5688a1156ff7db03d26ab3903886a14c --- /dev/null +++ b/XsYXACeIklU.txt @@ -0,0 +1,2517 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high quality educational +resources for free. + +To make a donation or view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +JOHN TSITSIKLIS: Today we're +going to finish our discussion + +of the Poisson process. + +We're going to see a few of +its properties, do a few + +interesting problems, some more +interesting than others. + +So go through a few examples and +then we're going to talk + +about some quite strange things +that happen with the + +Poisson process. + +So the first thing is to +remember what the Poisson + +processes is. + +It's a model, let's say, of +arrivals of customers that + +are, in some sense, quote +unquote, completely random, + +that is a customer can arrive +at any point in time. + +All points in time are +equally likely. + +And different points in time +are sort of independent of + +other points in time. + +So the fact that I got an +arrival now doesn't tell me + +anything about whether there's +going to be an arrival at some + +other time. + +In some sense, it's a continuous +time version of the + +Bernoulli process. + +So the best way to think about +the Poisson process is that we + +divide time into extremely +tiny slots. + +And in each time slot, there's +an independent possibility of + +having an arrival. + +Different time slots are +independent of each other. + +On the other hand, when the slot +is tiny, the probability + +for obtaining an arrival during +that tiny slot is + +itself going to be tiny. + +So we capture these properties +into a formal definition what + +the Poisson process is. + +We have a probability mass +function for the number of + +arrivals, k, during an interval +of a given length. + +So this is the sort of basic +description of the + +distribution of the number +of arrivals. + +So tau is fixed. + +And k is the parameter. + +So when we add over all k's, the +sum of these probabilities + +has to be equal to 1. + +There's a time homogeneity +assumption, which is hidden in + +this, namely, the only thing +that matters is the duration + +of the time interval, not where +the time interval sits + +on the real axis. + +Then we have an independence +assumption. + +Intervals that are disjoint are +statistically independent + +from each other. + +So any information you give me +about arrivals during this + +time interval doesn't change my +beliefs about what's going + +to happen during another +time interval. + +So this is a generalization +of the idea that we had in + +Bernoulli processes that +different time slots are + +independent of each other. + +And then to specify this +function, the distribution of + +the number of arrivals, we +sort of go in stages. + +We first specify this function +for the case where the time + +interval is very small. + +And I'm telling you what those +probabilities will be. + +And based on these then, we do +some calculations and to find + +the formula for the distribution +of the number of + +arrivals for intervals of +a general duration. + +So for a small duration, delta, +the probability of + +obtaining 1 arrival +is lambda delta. + +The remaining probability is +assigned to the event that we + +get to no arrivals during +that interval. + +The probability of obtaining +more than 1 arrival in a tiny + +interval is essentially 0. + +And when we say essentially, +it's means modular, terms that + +of order delta squared. + +And when delta is very small, +anything which is delta + +squared can be ignored. + +So up to delta squared terms, +that's what happened during a + +little interval. + +Now if we know the probability +distribution for the number of + +arrivals in a little interval. + +We can use this to get the +distribution for the number of + +arrivals over several +intervals. + +How do we do that? + +The big interval is composed +of many little intervals. + +Each little interval is +independent from any other + +little interval, so is it is +as if we have a sequence of + +Bernoulli trials. + +Each Bernoulli trial is +associated with a little + +interval and has a small +probability of obtaining a + +success or an arrival during +that mini-slot. + +On the other hand, when delta +is small, and you take a big + +interval and chop it +up, you get a large + +number of little intervals. + +So what we essentially have here +is a Bernoulli process, + +in which is the number of +trials is huge but the + +probability of success during +any given trial is tiny. + +The average number of trials +ends up being proportional to + +the length of the interval. + +If you have twice as large an +interval, it's as if you're + +having twice as many over these +mini-trials, so the + +expected number of arrivals will +increase proportionately. + +There's also this parameter +lambda, which we interpret as + +expected number of arrivals +per unit time. + +And it comes in those +probabilities here. + +When you double lambda, this +means that a little interval + +is twice as likely to +get an arrival. + +So you would expect +to get twice as + +many arrivals as well. + +That's why the expected number +of arrivals during an interval + +of length tau also scales +proportional to + +this parameter lambda. + +Somewhat unexpectedly, it turns +out that the variance of + +the number of arrivals is also +the same as the mean. + +This is a peculiarity +that happens + +in the Poisson process. + +So this is one way of thinking +about Poisson process, in + +terms of little intervals, each +one of which has a tiny + +probability of success. + +And we think of the distribution +associated with + +that process as being +described by + +this particular PMF. + +So this is the PMF for the +number of arrivals during an + +interval of a fixed +duration, tau. + +It's a PMF that extends all +over the entire range of + +non-negative integers. + +So the number of arrivals you +can get during an interval for + +certain length can +be anything. + +You can get as many arrivals +as you want. + +Of course the probability of +getting a zillion arrivals is + +going to be tiny. + +But in principle, this +is possible. + +And that's because an interval, +even if it's a fixed + +length, consists of an infinite +number of mini-slots + +in some sense. + +You can divide, chop +it up, into as many + +mini-slots as you want. + +So in principle, it's +possible that every + +mini-slot gets an arrival. + +In principle, it's possible to +get an arbitrarily large + +number of arrivals. + +So this particular formula here +is not very intuitive + +when you look at it. + +But it's a legitimate PMF. + +And it's called the +Poisson PMF. + +It's the PMF that describes +the number of arrivals. + +So that's one way of thinking +about the Poisson process, + +where the basic object of +interest would be this PMF and + +you try to work with it. + +There's another way of thinking +about what happens in + +the Poisson process. + +And this has to do with letting +things evolve in time. + +You start at time 0. + +There's going to be a time at +which the first arrival + +occurs, and call that time T1. + +This time turns out to have an +exponential distribution with + +parameter lambda. + +Once you get an arrival, +it's as if the + +process starts fresh. + +The best way to understand why +this is the case is by + +thinking in terms of +the analogy with + +the Bernoulli process. + +If you believe that statement +for the Bernoulli process, + +since this is a limiting case, +it should also be true. + +So starting from this time, +we're going to wait a random + +amount of time until we get the +second arrival This random + +amount of time, let's +call it T2. + +This time, T2 is also going +to have an exponential + +distribution with the same +parameter, lambda. + +And these two are going to be +independent of each other. + +OK? + +So the Poisson process has all +the same memorylessness + +properties that the Bernoulli +process has. + +What's another way of thinking +of this property? + +So think of a process where +you have a light bulb. + +The time at the light bulb burns +out, you can model it by + +an exponential random +variable. + +And suppose that they tell you +that so far, we're are sitting + +at some time, T. And I tell you +that the light bulb has + +not yet burned out. + +What does this tell you about +the future of the light bulb? + +Is the fact that they didn't +burn out, so far, is it good + +news or is it bad news? + +Would you rather keep this light +bulb that has worked for + +t times steps and is still OK? + +Or would you rather use a new +light bulb that starts new at + +that point in time? + +Because of the memorylessness +property, the past of that + +light bulb doesn't matter. + +So the future of this light bulb +is statistically the same + +as the future of a +new light bulb. + +For both of them, the time until +they burn out is going + +to be described an exponential +distribution. + +So one way that people described +the situation is to + +say that used is exactly +as good as a new. + +So a used on is no worse +than a new one. + +A used one is no better +than a new one. + +So a used light bulb that +hasn't yet burnt out is + +exactly as good as +a new light bulb. + +So that's another way of +thinking about the + +memorylessness that we have +in the Poisson process. + +Back to this picture. + +The time until the second +arrival is the sum of two + +independent exponential +random variables. + +So, in principle, you can use +the convolution formula to + +find the distribution of T1 +plus T2, and that would be + +what we call Y2, the time until +the second arrival. + +But there's also a direct +way of obtaining to the + +distribution of Y2, and this is +the calculation that we did + +last time on the blackboard. + +And actually, we did +it more generally. + +We found the time until the +case arrival occurs. + +It has a closed form formula, +which is called the Erlang + +distribution with k degrees +of freedom. + +So let's see what's +going on here. + +It's a distribution +Of what kind? + +It's a continuous +distribution. + +It's a probability +density function. + +This is because the time is a +continuous random variable. + +Time is continuous. + +Arrivals can happen +at any time. + +So we're talking +about the PDF. + +This k is just the parameter +of the distribution. + +We're talking about the +k-th arrival, so + +k is a fixed number. + +Lambda is another parameter of +the distribution, which is the + +arrival rate So it's a PDF over +the Y's, whereas lambda + +and k are parameters of +the distribution. + +OK. + +So this was what we knew +from last time. + +Just to get some practice, let +us do a problem that's not too + +difficult, but just to see how +we use the various formulas + +that we have. + +So Poisson was a mathematician, +but Poisson + +also means fish in French. + +So Poisson goes fishing. + +And let's assume that fish +are caught according + +to a Poisson process. + +That's not too bad +an assumption. + +At any given point in time, you +have a little probability + +that a fish would be caught. + +And whether you catch one now +is sort of independent about + +whether at some later time a +fish will be caught or not. + +So let's just make +this assumption. + +And suppose that the rules of +the game are that you-- + +Fish are being called it the +certain rate of 0.6 per hour. + +You fish for 2 hours, +no matter what. + +And then there are two +possibilities. + +If I have caught a fish, +I stop and go home. + +So if some fish have been +caught, so there's at least 1 + +arrival during this interval, +I go home. + +Or if nothing has being caught, +I continue fishing + +until I catch something. + +And then I go home. + +So that's the description of +what is going to happen. + +And now let's starts asking +questions of all sorts. + +What is the probability that +I'm going to be fishing for + +more than 2 hours? + +I will be fishing for more than +2 hours, if and only if + +no fish were caught during those +2 hours, in which case, + +I will have to continue. + +Therefore, this is just +this quantity. + +The probability of catching +2 fish in-- + +of catching 0 fish in the next +2 hours, and according to the + +formula that we have, this is +going to be e to the minus + +lambda times how much +time we have. + +There's another way of +thinking about this. + +The probability that I fish for +more than 2 hours is the + +probability that the first catch +happens after time 2, + +which would be the integral +from 2 to infinity of the + +density of the first +arrival time. + +And that density is +an exponential. + +So you do the integral of an +exponential, and, of course, + +you would get the same answer. + +OK. + +That's easy. + +So what's the probability of +fishing for more than 2 but + +less than 5 hours? + +What does it take for +this to happen? + +For this to happen, we need to +catch 0 fish from time 0 to 2 + +and catch the first fish +sometime between 2 and 5. + +So if you-- + +one way of thinking about what's +happening here might be + +to say that there's a +Poisson process that + +keeps going on forever. + +But as soon as I catch the +first fish, instead of + +continuing fishing and obtaining +those other fish I + +just go home right now. + +Now the fact that I go home +before time 5 means that, if I + +were to stay until time +5, I would have + +caught at least 1 fish. + +I might have caught +more than 1. + +So the event of interest here +is that the first catch + +happens between times 2 and 5. + +So one way of calculating +this quantity would be-- + +Its the probability that the +first catch happens between + +times 2 and 5. + +Another way to deal with it +is to say, this is the + +probability that I caught 0 fish +in the first 2 hours and + +then the probability that I +catch at least 1 fish during + +the next 3 hours. + +This. + +What is this? + +The probability of 0 fish in +the next 3 hours is the + +probability of 0 fish +during this time. + +1 minus this is the probability +of catching at + +least 1 fish, of having +at least 1 arrival, + +between times 2 and 5. + +If there's at least 1 arrival +between times 2 and 5, then I + +would have gone home +by time 5. + +So both of these, if you plug-in +numbers and all that, + +of course, are going to give +you the same answer. + +Now next, what's the probability +that I catch at + +least 2 fish? + +In which scenario are we? + +Under this scenario, I go home +when I catch my first fish. + +So in order to catch +at least 2 fish, it + +must be in this case. + +So this is the same as the event +that I catch at least 2 + +fish during the first +2 time steps. + +So it's going to be the +probability from 2 to + +infinity, the probability that +I catch 2 fish, or that I + +catch 3 fish, or I catch +more than that. + +So it's this quantity. + +k is the number of fish +that I catch. + +At least 2, so k goes +from 2 to infinity. + +These are the probabilities of +catching a number k of fish + +during this interval. + +And if you want a simpler form +without an infinite sum, this + +would be 1 minus the probability +of catching 0 + +fish, minus the probability of +catching 1 fish, during a time + +interval of length 2. + +Another way to think of it. + +I'm going to catch 2 fish, at +least 2 fish, if and only if + +the second fish caught in this +process happens before time 2. + +So that's another way of +thinking about the same event. + +So it's going to be the +probability that the random + +variable Y2, the arrival time +over the second fish, is less + +than or equal to 2. + +OK. + +The next one is a +little trickier. + +Here we need to do a little +bit of divide and conquer. + +Overall, in this expedition, +what the expected number of + +fish to be caught? + +One way to think about it is +to try to use the total + +expectations theorem. + +And think of expected number of +fish, given this scenario, + +or expected number of fish, +given this scenario. + +That's a little more complicated +than the way I'm + +going to do it. + +The way I'm going to do is +to think as follows-- + +Expected number of fish is the +expected number of fish caught + +between times 0 and 2 plus +expected number of fish caught + +after time 2. + +So what's the expected number +caught between time 0 and 2? + +This is lambda t. + +So lambda is 0.6 times 2. + +This is the expected number of +fish that are caught between + +times 0 and 2. + +Now let's think about the +expected number of fish caught + +afterwards. + +How many fish are being +caught afterwards? + +Well it depends on +the scenario. + +If we're in this scenario, +we've gone home + +and we catch 0. + +If we're in this scenario, then +we continue fishing until + +we catch one. + +So the expected number of fish +to be caught after time 2 is + +going to be the probability +of this scenario times 1. + +And the probability of that +scenario is the probability + +that they call it's 0 fish +during the first 2 time steps + +times 1, which is the number of +fish I'm going to catch if + +I continue. + +The expected total fishing time +we can calculate exactly + +the same way. + +I'm jumping to the last one. + +My total fishing time has a +period of 2 time steps. + +I'm going to fish for 2 time +steps no matter what. + +And then if I caught 0 fish, +which happens with this + +probability, my expected time +is going to be the expected + +time from here onwards, which is +the expected value of this + +geometric random variable +with parameter lambda. + +So the expected time +is 1 over lambda. + +And in our case this, +is 1/0.6. + +Finally, if I tell you that I +have been fishing for 4 hours + +and nothing has been caught so +far, how much do you expect + +this quantity to be? + +Here is the story that, again, +that for the Poisson process + +used is as good as new. + +The process does not +have any memory. + +Given what happens in the past +doesn't matter for the future. + +It's as if the process starts +new at this point in time. + +So this one is going to be, +again, the same exponentially + +distributed random +variable with the + +same parameter lambda. + +So expected time until an +arrival comes is an + +exponential distribut -- + +has an exponential distribution +with parameter + +lambda, no matter what has +happened in the past. + +Starting from now and looking +into the future, it's as if + +the process has just started. + +So it's going to be 1 over +lambda, which is 1/0.6. + +OK. + +Now our next example is going +to be a little more + +complicated or subtle. + +But before we get to the +example, let's refresh our + +memory about what we discussed +last time about merging + +Poisson independent +Poisson processes. + +Instead of drawing the picture +that way, another way we could + +draw it could be this. + +We have a Poisson process with +rate lambda1, and a Poisson + +process with rate lambda2. + +They have, each one of these, +have their arrivals. + +And then we form the +merged process. + +And the merged process records +an arrival whenever there's an + +arrival in either of +the two processes. + +This process in that process are +assumed to be independent + +of each other. + +Now different times in this +process and that process are + +independent of each other. + +So what happens in these two +time intervals is independent + +from what happens in these +two time intervals. + +These two time intervals to +determine what happens here. + +These two time intervals +determine what happens there. + +So because these are independent +from these, this + +means that this is also +independent from that. + +So the independence assumption +is satisfied + +for the merged process. + +And the merged process turns out +to be a Poisson process. + +And if you want to find the +arrival rate for that process, + +you argue as follows. + +During a little interval of +length delta, we have + +probability lambda1 +delta of having an + +arrival in this process. + +We have probability lambda2 +delta of an arrival in this + +process, plus second +order terms in + +delta, which we're ignoring. + +And then you do the calculation +and you find that + +in this process, you're going +to have an arrival + +probability, which is lambda1 +plus lambda2, again ignoring + +second order in delta-- + +terms that are second +order in delta. + +So the merged process is a +Poisson process whose arrival + +rate is the sum of the +arrival rates of + +the individual processes. + +And the calculation we did at +the end of the last lecture-- + +If I tell you that the new +arrival happened here, where + +did that arrival come from? + +Did it come from here +or from there? + +If the lambda1 is equal to +lambda2, then by symmetry you + +would say that it's equally +likely to have come from here + +or to come from there. + +But if this lambda is much +bigger than that lambda, the + +fact that they saw an arrival +is more likely to have come + +from there. + +And the formula that captures +this is the following. + +This is the probability that my +arrival has come from this + +particular stream rather than +that particular stream. + +So when an arrival comes and you +ask, what is the origin of + +that arrival? + +It's as if I'm flipping a +coin with these odds. + +And depending on outcome of that +coin, I'm going to tell + +you came from there or +it came from there. + +So the origin of an arrival +is either this + +stream or that stream. + +And this is the probability that +the origin of the arrival + +is that one. + +Now if we look at 2 different +arrivals, and we ask about + +their origins-- + +So let's think about the origin +of this arrival and + +compare it with the origin +that arrival. + +The origin of this arrival +is random. + +It could be right be either +this or that. + +And this is the relevant +probability. + +The origin of that arrival +is random. + +It could be either here or is +there, and again, with the + +same relevant probability. + +Question. + +The origin of this arrival, is +it dependent or independent + +from the origin that arrival? + +And here's how the +argument goes. + +Separate times are +independent. + +Whatever has happened in the +process during this set of + +times is independent from +whatever happened in the + +process during that +set of times. + +Because different times have +nothing to do with each other, + +the origin of this, of an +arrival here, has nothing to + +do with the origin of +an arrival there. + +So the origins of different +arrivals are also independent + +random variables. + +So if I tell you that-- + +yeah. + +OK. + +So it as if that each time that +you have an arrival in + +the merge process, it's as if +you're flipping a coin to + +determine where did that arrival +came from and these + +coins are independent +of each other. + +OK. + +OK. + +Now we're going to use this-- + +what we know about merged +processes to solve the problem + +that would be harder to do, if +you were not using ideas from + +Poisson processes. + +So the formulation of the +problem has nothing to do with + +the Poisson process. + +The formulation is +the following. + +We have 3 light-bulbs. + +And each light bulb is +independent and is going to + +die out at the time that's +exponentially distributed. + +So 3 light bulbs. + +They start their lives and +then at some point + +they die or burn out. + +So let's think of this as X, +this as Y, and this as Z. + +And we're interested in the +time until the last + +light-bulb burns out. + +So we're interested in the +maximum of the 3 random + +variables, X, Y, and Z. And in +particular, we want to find + +the expected value +of this maximum. + +OK. + +So you can do derived +distribution, use the expected + +value rule, anything you want. + +You can get this answer using +the tools that you already + +have in your hands. + +But now let us see how we can +connect to this picture with a + +Poisson picture and come up +with the answer in a very + +simple way. + +What is an exponential +random variable? + +An exponential random variable +is the first act in the long + +play that involves a whole +Poisson process. + +So an exponential random +variable is the first act of a + +Poisson movie. + +Same thing here. + +You can think of this random +variable as being part of some + +Poisson process that +has been running. + +So it's part of this +bigger picture. + +We're still interested in +the maximum of the 3. + +The other arrivals are not going +to affect our answers. + +It's just, conceptually +speaking, we can think of the + +exponential random variable as +being embedded in a bigger + +Poisson picture. + +So we have 3 Poisson process +that are running in parallel. + +Let us split the expected time +until the last burnout into + +pieces, which is time until the +first burnout, time from + +the first until the second, +and time from the + +second until the third. + +And find the expected values of +each one of these pieces. + +What can we say about the +expected value of this? + +This is the first arrival +out of all of + +these 3 Poisson processes. + +It's the first event that +happens when you look at all + +of these processes +simultaneously. + +So 3 Poisson processes +running in parallel. + +We're interested in the time +until one of them, any one of + +them, gets in arrival. + +Rephrase. + +We merged the 3 Poisson +processes, and we ask for the + +time until we observe an arrival +in the merged process. + +When 1 of the 3 gets an arrival +for the first time, + +the merged process gets +its first arrival. + +So what's the expected +value of this time + +until the first burnout? + +It's going to be the +expected value of a + +Poisson random variable. + +So the first burnout is going +to have an expected + +value, which is-- + +OK. + +It's a Poisson process. + +The merged process of the 3 has +a collective arrival rate, + +which is 3 times lambda. + +So this is the parameter over +the exponential distribution + +that describes the time until +the first arrival in the + +merged process. + +And the expected value +of this random + +variable is 1 over that. + +When you have an exponential +random variable with parameter + +lambda, the expected value +of that random + +variable is 1 over lambda. + +Here we're talking about the +first arrival time in a + +process with rate 3 lambda. + +The expected time until +the first arrival + +is 1 over (3 lambda). + +Alright. + +So at this time, this bulb, this +arrival happened, this + +bulb has been burned. + +So we don't care about +that bulb anymore. + +We start at this time, +and we look forward. + +This bulb has been burned. + +So let's just look forward +from now on. + +What have we got? + +We have two bulbs that +are burning. + +We have a Poisson process that's +the bigger picture of + +what could happen to that light +bulb, if we were to keep + +replacing it. + +Another Poisson process. + +These two processes are, +again, independent. + +From this time until that time, +how long does it take? + +It's the time until either +this process records an + +arrival or that process +records and arrival. + +That's the same as the time +that the merged process of + +these two records an arrival. + +So we're talking about the +expected time until the first + +arrival in a merged process. + +The merged process is Poisson. + +It's Poisson with +rate 2 lambda. + +So that extra time is +going to take-- + +the expected value is going to +be 1 over the (rate of that + +Poisson process). + +So 1 over (2 lambda) is +the expected value + +of this random variable. + +So at this point, this bulb +now is also burned. + +So we start looking +from this time on. + +That part of the picture +disappears. + +Starting from this time, what's +the expected value + +until that remaining light-bulb +burns out? + +Well, as we said before, in +a Poisson process or with + +exponential random variables, +we have memorylessness. + +A used bulb is as good +as a new one. + +So it's as if we're starting +from scratch here. + +So this is going to be an +exponential random variable + +with parameter lambda. + +And the expected value of it is +going to be 1 over lambda. + +So the beauty of approaching +this problem in this + +particular way is, of course, +that we manage to do + +everything without any calculus +at all, without + +striking an integral, without +trying to calculate + +expectations in any form. + +Most of the non-trivial problems +that you encounter in + +the Poisson world basically +involve tricks of these kind. + +You have a question and you try +to rephrase it, trying to + +think in terms of what might +happen in the Poisson setting, + +use memorylessness, use merging, +et cetera, et cetera. + +Now we talked about merging. + +It turns out that the splitting +of Poisson processes + +also works in a nice way. + +The story here is exactly +the same as for + +the Bernoulli process. + +So I'm having a Poisson +process. + +And each time, with some rate +lambda, and each time that an + +arrival comes, I'm going to send +it to that stream and the + +record an arrival here with some +probability P. And I'm + +going to send it to the other +stream with some probability 1 + +minus P. So either of this +will happen or that will + +happen, depending on +the outcome of the + +coin flip that I do. + +Each time that then arrival +occurs, I flip a coin and I + +decide whether to record +it here or there. + +This is called splitting +a Poisson + +process into two pieces. + +What kind of process +do we get here? + +If you look at the little +interval for length delta, + +what's the probability +that this little + +interval gets an arrival? + +It's the probability that this +one gets an arrival, which is + +lambda delta times the +probability that after I get + +an arrival my coin flip came out +to be that way, so that it + +sends me there. + +So this means that this little +interval is going to have + +probability lambda delta P. Or +maybe more suggestively, I + +should write it as lambda +P times delta. + +So every little interval has +a probability of an arrival + +proportional to delta. + +The proportionality factor is +lambda P. So lambda P is the + +rate of that process. + +And then you go through the +mental exercise that you went + +through for the Bernoulli +process to argue that a + +different intervals here are +independent and so on. + +And that completes checking that +this process is going to + +be a Poisson process. + +So when you split a Poisson +process by doing independent + +coin flips each time that +something happens, the + +processes that you get is again +a Poisson process, but + +of course with a reduced rate. + +So instead of the word +splitting, sometimes people + +also use the words +thinning-out. + +That is, out of the arrivals +that came, you keep a few but + +throw away a few. + +OK. + +So now the last topic over +this lecture is a quite + +curious phenomenon that +goes under the + +name of random incidents. + +So here's the story. + +Buses have been running +on Mass Ave. from time + +immemorial. + +And the bus company that runs +the buses claims that they + +come as a Poisson process with +some rate, let's say, of 4 + +buses per hour. + +So that the expected time +between bus arrivals is going + +to be 15 minutes. + +OK. + +Alright. + +So people have been complaining +that they have + +been showing up there. + +They think the buses are +taking too long. + +So you are asked +to investigate. + +Is the company-- + +Does it operate according +to its promises or not. + +So you send an undercover agent +to go and check the + +interarrival times +of the buses. + +Are they 15 minutes? + +Or are they longer? + +So you put your dark glasses +and you show up at the bus + +stop at some random time. + +And you go and ask the guy in +the falafel truck, how long + +has it been since the +last arrival? + +So of course that guy works +for the FBI, right? + +So they tell you, well, it's +been, let's say, 12 minutes + +since the last bus arrival. + +And then you say, +"Oh, 12 minutes. + +Average time is 15. + +So a bus should be coming +any time now." + +Is that correct? + +No, you wouldn't +think that way. + +It's a Poisson process. + +It doesn't matter how long +it has been since + +the last bus arrival. + +So you don't go through +that fallacy. + +Instead of predicting how long +it's going to be, you just sit + +down there and wait and +measure the time. + +And you find that this is, +let's say, 11 minutes. + +And you go to your boss and +report, "Well, it took-- + +I went there and the time from +the previous bus to the next + +one was 23 minutes. + +It's more than the 15 +that they said." + +So go and do that again. + +You go day after day. + +You keep these statistics of the +length of this interval. + +And you tell your boss it's +a lot more than 15. + +It tends to be more +like 30 or so. + +So the bus company +is cheating us. + +Does the bus company really run +Poisson buses at the rate + +that they have promised? + +Well let's analyze the situation +here and figure out + +what the length of +this interval + +should be, on the average. + +The naive argument is that +this interval is an + +interarrival time. + +And interarrival times, on the +average, are 15 minutes, if + +the company runs indeed Poisson +processes with these + +interarrival times. + +But actually the situation is +a little more subtle because + +this is not a typical +interarrival interval. + +This interarrival interval +consists of two pieces. + +Let's call them T1 +and T1 prime. + +What can you tell me about those +two random variables? + +What kind of random +variable is T1? + +Starting from this time, with +the Poisson process, the past + +doesn't matter. + +It's the time until an +arrival happens. + +So T1 is going to be an +exponential random variable + +with parameter lambda. + +So in particular, the expected +value of T1 is + +going to be 15 by itself. + +How about the random +variable T1 prime. + +What kind of random +variable is it? + +This is like the first arrival +in a Poisson process that runs + +backwards in time. + +What kind of process is a +Poisson process running + +backwards in time? + +Let's think of coin flips. + +Suppose you have a movie +of coin flips. + +And for some accident, that +fascinating movie, you happen + +to watch it backwards. + +Will it look any different +statistically? + +No. + +It's going to be just the +sequence of random coin flips. + +So a Bernoulli process that's +runs in reverse time is + +statistically identical +to a Bernoulli + +process in forward time. + +The Poisson process is a +limit of the Bernoulli. + +So, same story with the +Poisson process. + +If you run it backwards in +time it looks the same. + +So looking backwards in time, +this is a Poisson process. + +And T1 prime is the time until +the first arrival in this + +backward process. + +So T1 prime is also going to +be an exponential random + +variable with the same +parameter, lambda. + +And the expected value +of T1 prime is 15. + +Conclusion is that the expected +length of this + +interval is going to +be 30 minutes. + +And the fact that this agent +found the average to be + +something like 30 does not +contradict the claims of the + +bus company that they're running +Poisson buses with a + +rate of lambda equal to 4. + +OK. + +So maybe the company can this +way-- they can defend + +themselves in court. + +But there's something +puzzling here. + +How long is the interarrival +time? + +Is it 15? + +Or is it 30? + +On the average. + +The issue is what do we +mean by a typical + +interarrival time. + +When we say typical, we mean +some kind of average. + +But average over what? + +And here's two different ways +of thinking about averages. + +You number the buses. + +And you have bus number 100. + +You have bus number 101, +bus number 102, bus + +number 110, and so on. + +One way of thinking about +averages is that you pick a + +bus number at random. + +I pick, let's say, that bus, +all buses being sort of + +equally likely to be picked. + +And I measure this interarrival +time. + +So for a typical bus. + +Then, starting from here until +there, the expected time has + +to be 1 over lambda, for +the Poisson process. + +But what we did in +this experiment + +was something different. + +We didn't pick a +bus at random. + +We picked a time at random. + +And if the picture is, let's +say, this way, I'm much more + +likely to pick this interval +and therefore this + +interarrival time, rather +than that interval. + +Because, this interval +corresponds to very few times. + +So if I'm picking a time at +random and, in some sense, + +let's say, uniform, so that all +times are equally likely, + +I'm much more likely to fall +inside a big interval rather + +than a small interval. + +So a person who shows up at the +bus stop at a random time. + +They're selecting an interval in +a biased way, with the bias + +favor of longer intervals. + +And that's why what they observe +is a random variable + +that has a larger expected +value then the ordinary + +expected value. + +So the subtlety here is to +realize that we're talking + +between two different kinds +of experiments. + +Picking a bus number at random +verses picking an interval at + +random with a bias in favor +of longer intervals. + +Lots of paradoxes that one +can cook up using Poisson + +processes and random processes +in general often have to do + +with the story of this kind. + +The phenomenon that we had in +this particular example also + +shows up in general, whenever +you have other kinds of + +arrival processes. + +So the Poisson process is the +simplest arrival process there + +is, where the interarrival +times are + +exponential random variables. + +There's a larger class +of models. + +They're called renewal +processes, in which, again, we + +have a sequence of successive +arrivals, interarrival times + +are identically distributed and +independent, but they may + +come from a general +distribution. + +So to make the same point of the +previous example but in a + +much simpler setting, suppose +that bus interarrival times + +are either 5 or 10 +minutes apart. + +So you get some intervals +that are of length 5. + +You get some that are +of length 10. + +And suppose that these +are equally likely. + +So we have -- not exactly -- + +In the long run, we have as many +5 minute intervals as we + +have 10 minute intervals. + +So the average interarrival +time is 7 and 1/2. + +But if a person shows up at a +random time, what are they + +going to see? + +Do we have as many 5s as 10s? + +But every 10 covers twice +as much space. + +So if I show up at a random +time, I have probability 2/3 + +falling inside an interval +of duration 10. + +And I have one 1/3 probability +of falling inside an interval + +of duration 5. + +That's because, out of the whole +real line, 2/3 of it is + +covered by intervals +of length 10, just + +because they're longer. + +1/3 is covered by the +smaller intervals. + +Now if I fall inside an interval +of length 10 and I + +measure the length of the +interval that I fell into, + +that's going to be 10. + +But if I fall inside an interval +of length 5 and I + +measure how long it is, +I'm going to get a 5. + +And that, of course, is going +to be different than 7.5. + +OK. + +And which number should +be bigger? + +It's the second number that's +bigger because this one is + +biased in favor of the +longer intervals. + +So that's, again, another +illustration of the different + +results that you get when you +have this random incidence + +phenomenon. + +So the bottom line, again, is +that if you talk about a + +typical interarrival time, one +must be very precise in + +specifying what we +mean typical. + +So typical means +sort of random. + +But to use the word random, +you must specify very + +precisely what is the random +experiment that you are using. + +And if you're not careful, you +can get into apparent puzzles, + +such as the following. + +Suppose somebody tells you the +average family size is 4, but + +the average person lives +in a family of size 6. + +Is that compatible? + +Family size is 4 on the average, +but typical people + +live, on the average, in +families of size 6. + +Well yes. + +There's no contradiction here. + +We're talking about two +different experiments. + +In one experiment, I pick a +family at random, and I tell + +you the average family is 4. + +In another experiment, I pick a +person at random and I tell + +you that this person, on the +average, will be in their + +family of size 6. + +And what is the catch here? + +That if I pick a person at +random, large families are + +more likely to be picked. + +So there's a bias in favor +of large families. + +Or if you want to survey, let's +say, are trains crowded + +in your city? + +Or are buses crowded? + +One choice is to pick a bus +at random and inspect + +how crowded it is. + +Another choice is to pick a +typical person and ask them, + +"Did you ride the bus today? + +Was it's crowded?" Well suppose +that in this city + +there's one bus that's extremely +crowded and all the + +other buses are completely +empty. + +If you ask a person. "Was your +bus crowded?" They will tell + +you, "Yes, my bus was crowded." +There's no witness + +from the empty buses to testify +in their favor. + +So by sampling people instead +of sampling buses, you're + +going to get different result. + +And in the process industry, if +your job is to inspect and + +check cookies, you will be +faced with a big dilemma. + +Do you want to find out how many +chocolate chips there are + +on a typical cookie? + +Are you going to interview +cookies or are you going to + +interview chocolate chips and +ask them how many other chips + +where there on your cookie? + +And you're going to +get different + +answers in these cases. + +So moral is, one has to be +very precise on how you + +formulate the sampling procedure +that you have. + +And you'll get different +answers. \ No newline at end of file diff --git a/YAo1sd4kuOQ.txt b/YAo1sd4kuOQ.txt new file mode 100644 index 0000000000000000000000000000000000000000..6399b1e0193c79a28cb2c3109fcf093ee0d32258 --- /dev/null +++ b/YAo1sd4kuOQ.txt @@ -0,0 +1,8099 @@ +align:start position:0% + +so the first topic that I want to + + align:start position:0% +so the first topic that I want to + + + align:start position:0% +so the first topic that I want to +discuss in this course is extrema graph + + align:start position:0% +discuss in this course is extrema graph + + + align:start position:0% +discuss in this course is extrema graph +theory and in particular there's a whole + + align:start position:0% +theory and in particular there's a whole + + + align:start position:0% +theory and in particular there's a whole +class of problems which have to do with + + align:start position:0% +class of problems which have to do with + + + align:start position:0% +class of problems which have to do with +what happens if you forbid specific sub + + align:start position:0% +what happens if you forbid specific sub + + + align:start position:0% +what happens if you forbid specific sub +graph and ask you what's the maximum + + align:start position:0% +graph and ask you what's the maximum + + + align:start position:0% +graph and ask you what's the maximum +number of edges that can appear in your + + align:start position:0% +number of edges that can appear in your + + + align:start position:0% +number of edges that can appear in your +graph in particular and this is the + + align:start position:0% +graph in particular and this is the + + + align:start position:0% +graph in particular and this is the +question that we saw at the end of last + + align:start position:0% +question that we saw at the end of last + + + align:start position:0% +question that we saw at the end of last +lecture which tells theorem essentially + + align:start position:0% +lecture which tells theorem essentially + + + align:start position:0% +lecture which tells theorem essentially +asks if you know that your graph has no + + align:start position:0% +asks if you know that your graph has no + + + align:start position:0% +asks if you know that your graph has no +triangles what's the maximum number of + + align:start position:0% +triangles what's the maximum number of + + + align:start position:0% +triangles what's the maximum number of +edges it can have i ment else theorem + + align:start position:0% +edges it can have i ment else theorem + + + align:start position:0% +edges it can have i ment else theorem +tells us that the extreme example is + + align:start position:0% +tells us that the extreme example is + + + align:start position:0% +tells us that the extreme example is +when your graph consists of putting half + + align:start position:0% +when your graph consists of putting half + + + align:start position:0% +when your graph consists of putting half +the vertices on one side half the + + align:start position:0% +the vertices on one side half the + + + align:start position:0% +the vertices on one side half the +vertices on the other side and putting + + align:start position:0% +vertices on the other side and putting + + + align:start position:0% +vertices on the other side and putting +in all the edges between so this is a + + align:start position:0% +in all the edges between so this is a + + + align:start position:0% +in all the edges between so this is a +complete bipartite graph for these + + align:start position:0% +complete bipartite graph for these + + + align:start position:0% +complete bipartite graph for these +partitions we denote complete bipartite + + align:start position:0% +partitions we denote complete bipartite + + + align:start position:0% +partitions we denote complete bipartite +graphs like that and mentos theorem + + align:start position:0% +graphs like that and mentos theorem + + + align:start position:0% +graphs like that and mentos theorem +tells us that this graph among triangle + + align:start position:0% +tells us that this graph among triangle + + + align:start position:0% +tells us that this graph among triangle +free graphs has the most number of edges + + align:start position:0% +free graphs has the most number of edges + + + align:start position:0% +free graphs has the most number of edges +triangle free + + align:start position:0% + + + + align:start position:0% + +and vertices Haas at most so the number + + align:start position:0% +and vertices Haas at most so the number + + + align:start position:0% +and vertices Haas at most so the number +of edges there is N squared divided by + + align:start position:0% +of edges there is N squared divided by + + + align:start position:0% +of edges there is N squared divided by +four round down that many edges and from + + align:start position:0% +four round down that many edges and from + + + align:start position:0% +four round down that many edges and from +this example this bound is tight so when + + align:start position:0% +this example this bound is tight so when + + + align:start position:0% +this example this bound is tight so when +helstem gives us a completely + + align:start position:0% +helstem gives us a completely + + + align:start position:0% +helstem gives us a completely +satisfactory answer to the question of + + align:start position:0% +satisfactory answer to the question of + + + align:start position:0% +satisfactory answer to the question of +what's the maximum number of edges in a + + align:start position:0% +what's the maximum number of edges in a + + + align:start position:0% +what's the maximum number of edges in a +graph without triangles and I want to + + align:start position:0% +graph without triangles and I want to + + + align:start position:0% +graph without triangles and I want to +begin by showing you a few different + + align:start position:0% +begin by showing you a few different + + + align:start position:0% +begin by showing you a few different +proofs of mental serum with illustrating + + align:start position:0% +proofs of mental serum with illustrating + + + align:start position:0% +proofs of mental serum with illustrating +some different techniques in graph + + align:start position:0% +some different techniques in graph + + + align:start position:0% +some different techniques in graph +theory + + align:start position:0% +theory + + + align:start position:0% +theory +so we'll see quite a few proofs in + + align:start position:0% +so we'll see quite a few proofs in + + + align:start position:0% +so we'll see quite a few proofs in +today's lecture the first one begins + + align:start position:0% +today's lecture the first one begins + + + align:start position:0% +today's lecture the first one begins +well here's the setup I have G and + + align:start position:0% +well here's the setup I have G and + + + align:start position:0% +well here's the setup I have G and +vertex graph and let me denote the + + align:start position:0% +vertex graph and let me denote the + + + align:start position:0% +vertex graph and let me denote the +vertices and edges of G by if I have an + + align:start position:0% +vertices and edges of G by if I have an + + + align:start position:0% +vertices and edges of G by if I have an +edge in G between vertices x and y then + + align:start position:0% +edge in G between vertices x and y then + + + align:start position:0% +edge in G between vertices x and y then +note that they cannot have any common + + align:start position:0% +note that they cannot have any common + + + align:start position:0% +note that they cannot have any common +neighbors because I would see a triangle + + align:start position:0% + + + + align:start position:0% + +so what can we say about the degrees of + + align:start position:0% +so what can we say about the degrees of + + + align:start position:0% +so what can we say about the degrees of +the two endpoints of this edge they + + align:start position:0% +the two endpoints of this edge they + + + align:start position:0% +the two endpoints of this edge they +cannot add up to they cannot add up to + + align:start position:0% +cannot add up to they cannot add up to + + + align:start position:0% +cannot add up to they cannot add up to +more than n so in particular exactly the + + align:start position:0% +more than n so in particular exactly the + + + align:start position:0% +more than n so in particular exactly the +degrees of these two endpoints is at + + align:start position:0% +degrees of these two endpoints is at + + + align:start position:0% +degrees of these two endpoints is at +most n whenever XY edge + + align:start position:0% + + + + align:start position:0% + +well okay so now let me consider the + + align:start position:0% +well okay so now let me consider the + + + align:start position:0% +well okay so now let me consider the +quantity which is the sum of the squared + + align:start position:0% +quantity which is the sum of the squared + + + align:start position:0% +quantity which is the sum of the squared +degrees on one hand I claim that this + + align:start position:0% +degrees on one hand I claim that this + + + align:start position:0% +degrees on one hand I claim that this +sum is equal to this quantity here where + + align:start position:0% +sum is equal to this quantity here where + + + align:start position:0% +sum is equal to this quantity here where +I sum over all edges and the reason is + + align:start position:0% +I sum over all edges and the reason is + + + align:start position:0% +I sum over all edges and the reason is +we'll look at the sum suppose imagine + + align:start position:0% +we'll look at the sum suppose imagine + + + align:start position:0% +we'll look at the sum suppose imagine +writing out all the summons how many + + align:start position:0% +writing out all the summons how many + + + align:start position:0% +writing out all the summons how many +times does each DX come up each DX + + align:start position:0% +times does each DX come up each DX + + + align:start position:0% +times does each DX come up each DX +appears one for each edge accessing so + + align:start position:0% +appears one for each edge accessing so + + + align:start position:0% +appears one for each edge accessing so +appears exactly the x times but we saw + + align:start position:0% +appears exactly the x times but we saw + + + align:start position:0% +appears exactly the x times but we saw +from up here that each summon is at most + + align:start position:0% +from up here that each summon is at most + + + align:start position:0% +from up here that each summon is at most +n so this sum here is that most a men on + + align:start position:0% +n so this sum here is that most a men on + + + align:start position:0% +n so this sum here is that most a men on +the other hand let's consider the + + align:start position:0% +the other hand let's consider the + + + align:start position:0% +the other hand let's consider the +quantity which is just the sum of the + + align:start position:0% +quantity which is just the sum of the + + + align:start position:0% +quantity which is just the sum of the +degrees and you know sometimes known as + + align:start position:0% +degrees and you know sometimes known as + + + align:start position:0% +degrees and you know sometimes known as +the handshaking lemma that the sums of + + align:start position:0% +the handshaking lemma that the sums of + + + align:start position:0% +the handshaking lemma that the sums of +degrees is just twice the number of + + align:start position:0% +degrees is just twice the number of + + + align:start position:0% +degrees is just twice the number of +edges each edge is considered twice in + + align:start position:0% +edges each edge is considered twice in + + + align:start position:0% +edges each edge is considered twice in +this sum well now we apply the Cauchy + + align:start position:0% +this sum well now we apply the Cauchy + + + align:start position:0% +this sum well now we apply the Cauchy +Schwarz inequality which as you'll see + + align:start position:0% +Schwarz inequality which as you'll see + + + align:start position:0% +Schwarz inequality which as you'll see +many times in this course although you + + align:start position:0% +many times in this course although you + + + align:start position:0% +many times in this course although you +might think of it as a fairly simple + + align:start position:0% +might think of it as a fairly simple + + + align:start position:0% +might think of it as a fairly simple +inequality it's extremely powerful and + + align:start position:0% +inequality it's extremely powerful and + + + align:start position:0% +inequality it's extremely powerful and +it will come up pretty much throughout + + align:start position:0% +it will come up pretty much throughout + + + align:start position:0% +it will come up pretty much throughout +this course by the Cauchy Schwarz + + align:start position:0% +this course by the Cauchy Schwarz + + + align:start position:0% +this course by the Cauchy Schwarz +inequality you compare these two + + align:start position:0% +inequality you compare these two + + + align:start position:0% +inequality you compare these two +quantities I find that we have + + align:start position:0% + + + + align:start position:0% + +this inequality over here relating the + + align:start position:0% +this inequality over here relating the + + + align:start position:0% +this inequality over here relating the +sums of the degrees and square of the + + align:start position:0% +sums of the degrees and square of the + + + align:start position:0% +sums of the degrees and square of the +sum of the degrees but we saw on one + + align:start position:0% +sum of the degrees but we saw on one + + + align:start position:0% +sum of the degrees but we saw on one +hand the left hand side is for M Squared + + align:start position:0% +hand the left hand side is for M Squared + + + align:start position:0% +hand the left hand side is for M Squared +and we also saw the right hand side is + + align:start position:0% +and we also saw the right hand side is + + + align:start position:0% +and we also saw the right hand side is +that most M N squared putting them + + align:start position:0% +that most M N squared putting them + + + align:start position:0% +that most M N squared putting them +together we see that M is that most N + + align:start position:0% +together we see that M is that most N + + + align:start position:0% +together we see that M is that most N +squared over four and of course because + + align:start position:0% +squared over four and of course because + + + align:start position:0% +squared over four and of course because +it's an integer it's at most the floor + + align:start position:0% +it's an integer it's at most the floor + + + align:start position:0% +it's an integer it's at most the floor +of this number and that's a proof of + + align:start position:0% +of this number and that's a proof of + + + align:start position:0% +of this number and that's a proof of +mental stare what can you tell me about + + align:start position:0% +mental stare what can you tell me about + + + align:start position:0% +mental stare what can you tell me about +the Equality case in this proof I'll let + + align:start position:0% +the Equality case in this proof I'll let + + + align:start position:0% +the Equality case in this proof I'll let +you think about that but let me show you + + align:start position:0% +you think about that but let me show you + + + align:start position:0% +you think about that but let me show you +some other proofs in other words are + + align:start position:0% +some other proofs in other words are + + + align:start position:0% +some other proofs in other words are +there graphs with the same number of + + align:start position:0% +there graphs with the same number of + + + align:start position:0% +there graphs with the same number of +edges as the graph shown up there that + + align:start position:0% +edges as the graph shown up there that + + + align:start position:0% +edges as the graph shown up there that +is also triangle frequent it's not a + + align:start position:0% +is also triangle frequent it's not a + + + align:start position:0% +is also triangle frequent it's not a +unique example okay so let me show you a + + align:start position:0% +unique example okay so let me show you a + + + align:start position:0% +unique example okay so let me show you a +different proof of Mancow still in this + + align:start position:0% +different proof of Mancow still in this + + + align:start position:0% +different proof of Mancow still in this +proof so we begin with a step that seems + + align:start position:0% +proof so we begin with a step that seems + + + align:start position:0% +proof so we begin with a step that seems +a little tricky let's let a be a subset + + align:start position:0% +a little tricky let's let a be a subset + + + align:start position:0% +a little tricky let's let a be a subset +of vertices such that a is a largest + + align:start position:0% + + + + align:start position:0% + +gee remember independent set is subset + + align:start position:0% +gee remember independent set is subset + + + align:start position:0% +gee remember independent set is subset +of vertices with no edges inside you may + + align:start position:0% +of vertices with no edges inside you may + + + align:start position:0% +of vertices with no edges inside you may +have many independent sets all having + + align:start position:0% +have many independent sets all having + + + align:start position:0% +have many independent sets all having +the same maximum size take one of them + + align:start position:0% +the same maximum size take one of them + + + align:start position:0% +the same maximum size take one of them +why should you do this step sometimes + + align:start position:0% +why should you do this step sometimes + + + align:start position:0% +why should you do this step sometimes +magic happens + + align:start position:0% +magic happens + + + align:start position:0% +magic happens +let's consider some vertex there's some + + align:start position:0% +let's consider some vertex there's some + + + align:start position:0% +let's consider some vertex there's some +vertex let's say X and look at it + + align:start position:0% +vertex let's say X and look at it + + + align:start position:0% +vertex let's say X and look at it +neighborhood the neighborhood must be an + + align:start position:0% +neighborhood the neighborhood must be an + + + align:start position:0% +neighborhood the neighborhood must be an +independent set otherwise I get a + + align:start position:0% +independent set otherwise I get a + + + align:start position:0% +independent set otherwise I get a +triangle and as a result the degree of + + align:start position:0% +triangle and as a result the degree of + + + align:start position:0% +triangle and as a result the degree of +every vertex is at most the size of the + + align:start position:0% +every vertex is at most the size of the + + + align:start position:0% +every vertex is at most the size of the +largest so now let the complement so I + + align:start position:0% +largest so now let the complement so I + + + align:start position:0% +largest so now let the complement so I +have a every Edge has to intersect P the + + align:start position:0% +have a every Edge has to intersect P the + + + align:start position:0% +have a every Edge has to intersect P the +edge cannot be entirely containing a + + align:start position:0% +edge cannot be entirely containing a + + + align:start position:0% +edge cannot be entirely containing a +because a has no edges so the number of + + align:start position:0% +because a has no edges so the number of + + + align:start position:0% +because a has no edges so the number of +edges of G is at most I count over + + align:start position:0% +edges of G is at most I count over + + + align:start position:0% +edges of G is at most I count over +vertices in B the degree may be an over + + align:start position:0% +vertices in B the degree may be an over + + + align:start position:0% +vertices in B the degree may be an over +count so the edges containing B I count + + align:start position:0% +count so the edges containing B I count + + + align:start position:0% +count so the edges containing B I count +twice but that's okay so this is an + + align:start position:0% +twice but that's okay so this is an + + + align:start position:0% +twice but that's okay so this is an +upper bound on a number of edges but I + + align:start position:0% +upper bound on a number of edges but I + + + align:start position:0% +upper bound on a number of edges but I +also know that every vertex in the graph + + align:start position:0% +also know that every vertex in the graph + + + align:start position:0% +also know that every vertex in the graph +has degree at most the size of a so + + align:start position:0% +has degree at most the size of a so + + + align:start position:0% +has degree at most the size of a so +each someone is at most the size of a + + align:start position:0% +each someone is at most the size of a + + + align:start position:0% +each someone is at most the size of a +and I have the terms now by the a MGM + + align:start position:0% +and I have the terms now by the a MGM + + + align:start position:0% +and I have the terms now by the a MGM +inequality and the sizes of a and B add + + align:start position:0% +inequality and the sizes of a and B add + + + align:start position:0% +inequality and the sizes of a and B add +up to the entire vertex set and squared + + align:start position:0% +up to the entire vertex set and squared + + + align:start position:0% +up to the entire vertex set and squared +over 4 so that gives you another proof + + align:start position:0% +over 4 so that gives you another proof + + + align:start position:0% +over 4 so that gives you another proof +of men house theorem what does this + + align:start position:0% +of men house theorem what does this + + + align:start position:0% +of men house theorem what does this +proof tell us about the Equality case + + align:start position:0% + + + + align:start position:0% + +you know something I always want you to + + align:start position:0% +you know something I always want you to + + + align:start position:0% +you know something I always want you to +keep in mind when we do proofs is + + align:start position:0% +keep in mind when we do proofs is + + + align:start position:0% +keep in mind when we do proofs is +especially if we have a type example + + align:start position:0% +especially if we have a type example + + + align:start position:0% +especially if we have a type example +like that and later on and the course + + align:start position:0% +like that and later on and the course + + + align:start position:0% +like that and later on and the course +will almost never have good examples + + align:start position:0% +will almost never have good examples + + + align:start position:0% +will almost never have good examples +like that + + align:start position:0% +like that + + + align:start position:0% +like that +so this is still early on in the course + + align:start position:0% +so this is still early on in the course + + + align:start position:0% +so this is still early on in the course +we're still very clean examples is to + + align:start position:0% +we're still very clean examples is to + + + align:start position:0% +we're still very clean examples is to +keep the extremal example in mind and + + align:start position:0% +keep the extremal example in mind and + + + align:start position:0% +keep the extremal example in mind and +every step in your proof it should be + + align:start position:0% +every step in your proof it should be + + + align:start position:0% +every step in your proof it should be +tight for that example otherwise + + align:start position:0% +tight for that example otherwise + + + align:start position:0% +tight for that example otherwise +something went wrong with your proof + + align:start position:0% +something went wrong with your proof + + + align:start position:0% +something went wrong with your proof +let's think about the inequalities and + + align:start position:0% +let's think about the inequalities and + + + align:start position:0% +let's think about the inequalities and +equality we must have that so looking at + + align:start position:0% +equality we must have that so looking at + + + align:start position:0% +equality we must have that so looking at +this inequality so there are no edges in + + align:start position:0% +this inequality so there are no edges in + + + align:start position:0% +this inequality so there are no edges in +B we also have that by data every vertex + + align:start position:0% +B we also have that by data every vertex + + + align:start position:0% +B we also have that by data every vertex +in B is complete 2a + + align:start position:0% + + + + align:start position:0% + +and finally a and B should have the same + + align:start position:0% +and finally a and B should have the same + + + align:start position:0% +and finally a and B should have the same +size so it is exactly the configuration + + align:start position:0% +size so it is exactly the configuration + + + align:start position:0% +size so it is exactly the configuration +shown up there now when n is odd we're + + align:start position:0% +shown up there now when n is odd we're + + + align:start position:0% +shown up there now when n is odd we're +rounding down by one so you can lose a + + align:start position:0% +rounding down by one so you can lose a + + + align:start position:0% +rounding down by one so you can lose a +little bit and then you can check that + + align:start position:0% +little bit and then you can check that + + + align:start position:0% +little bit and then you can check that +actually what we described up there is + + align:start position:0% +actually what we described up there is + + + align:start position:0% +actually what we described up there is +also the unique example okay so so that + + align:start position:0% +also the unique example okay so so that + + + align:start position:0% +also the unique example okay so so that +graphic complete bipartite graph with + + align:start position:0% +graphic complete bipartite graph with + + + align:start position:0% +graphic complete bipartite graph with +two equal parts is the unique maximal + + align:start position:0% +two equal parts is the unique maximal + + + align:start position:0% +two equal parts is the unique maximal +example number of edges in a triangle + + align:start position:0% +example number of edges in a triangle + + + align:start position:0% +example number of edges in a triangle +free graph okay great so once we know + + align:start position:0% +free graph okay great so once we know + + + align:start position:0% +free graph okay great so once we know +what the answer is for triangle free of + + align:start position:0% +what the answer is for triangle free of + + + align:start position:0% +what the answer is for triangle free of +course we should ask further questions + + align:start position:0% +course we should ask further questions + + + align:start position:0% +course we should ask further questions +instead of forbidding a triangle what if + + align:start position:0% +instead of forbidding a triangle what if + + + align:start position:0% +instead of forbidding a triangle what if +we forbid other graphs so and what are + + align:start position:0% +we forbid other graphs so and what are + + + align:start position:0% +we forbid other graphs so and what are +some natural next steps to take instead + + align:start position:0% +some natural next steps to take instead + + + align:start position:0% +some natural next steps to take instead +of triangles we can ask what about if we + + align:start position:0% +of triangles we can ask what about if we + + + align:start position:0% +of triangles we can ask what about if we +prepared a K for a clique of four + + align:start position:0% +prepared a K for a clique of four + + + align:start position:0% +prepared a K for a clique of four +vertices or in general what if we forbid + + align:start position:0% +vertices or in general what if we forbid + + + align:start position:0% +vertices or in general what if we forbid +a click on the fixed number of vertices + + align:start position:0% +a click on the fixed number of vertices + + + align:start position:0% +a click on the fixed number of vertices +so what is the maximum edges there's a + + align:start position:0% +so what is the maximum edges there's a + + + align:start position:0% +so what is the maximum edges there's a +good reason why index an R plus one so + + align:start position:0% +good reason why index an R plus one so + + + align:start position:0% +good reason why index an R plus one so +for example if we're interested in K for + + align:start position:0% +for example if we're interested in K for + + + align:start position:0% +for example if we're interested in K for +free so what might be a good candidate + + align:start position:0% +free so what might be a good candidate + + + align:start position:0% +free so what might be a good candidate +for a graph with lots of edges that has + + align:start position:0% +for a graph with lots of edges that has + + + align:start position:0% +for a graph with lots of edges that has +no K for certainly that example we saw + + align:start position:0% +no K for certainly that example we saw + + + align:start position:0% +no K for certainly that example we saw +it does does not have K force because it + + align:start position:0% +it does does not have K force because it + + + align:start position:0% +it does does not have K force because it +doesn't have any triangles or we can do + + align:start position:0% +doesn't have any triangles or we can do + + + align:start position:0% +doesn't have any triangles or we can do +even better instead of taking two parts + + align:start position:0% +even better instead of taking two parts + + + align:start position:0% +even better instead of taking two parts +you can take more parts for K for if I + + align:start position:0% +you can take more parts for K for if I + + + align:start position:0% +you can take more parts for K for if I +take three parts each one n over three + + align:start position:0% +take three parts each one n over three + + + align:start position:0% +take three parts each one n over three +number of vertices of course if and it's + + align:start position:0% +number of vertices of course if and it's + + + align:start position:0% +number of vertices of course if and it's +not divisible by three round up and + + align:start position:0% +not divisible by three round up and + + + align:start position:0% +not divisible by three round up and +round down and putting all the edges + + align:start position:0% +round down and putting all the edges + + + align:start position:0% +round down and putting all the edges +between + + align:start position:0% +between + + + align:start position:0% +between +different parts you can see this graph + + align:start position:0% +different parts you can see this graph + + + align:start position:0% +different parts you can see this graph +here has no k4 okay so that's an example + + align:start position:0% +here has no k4 okay so that's an example + + + align:start position:0% +here has no k4 okay so that's an example +of a k4 free graph there's a half the + + align:start position:0% +of a k4 free graph there's a half the + + + align:start position:0% +of a k4 free graph there's a half the +maximum possible number of edges so is + + align:start position:0% +maximum possible number of edges so is + + + align:start position:0% +maximum possible number of edges so is +this the best that we can do so it turns + + align:start position:0% +this the best that we can do so it turns + + + align:start position:0% +this the best that we can do so it turns +out the answer is yes and that's the + + align:start position:0% +out the answer is yes and that's the + + + align:start position:0% +out the answer is yes and that's the +next theorem that we'll see but just to + + align:start position:0% +next theorem that we'll see but just to + + + align:start position:0% +next theorem that we'll see but just to +give it a name so we're going to call + + align:start position:0% +give it a name so we're going to call + + + align:start position:0% +give it a name so we're going to call +graphs like these to run graphs okay so + + align:start position:0% +graphs like these to run graphs okay so + + + align:start position:0% +graphs like these to run graphs okay so +next theorem is proved by Qur'an + + align:start position:0% +next theorem is proved by Qur'an + + + align:start position:0% +next theorem is proved by Qur'an +Torrance term so turn on graph go to + + align:start position:0% +Torrance term so turn on graph go to + + + align:start position:0% +Torrance term so turn on graph go to +node T and sub T sub n R it is a + + align:start position:0% +node T and sub T sub n R it is a + + + align:start position:0% +node T and sub T sub n R it is a +complete our part I graph such that + + align:start position:0% +complete our part I graph such that + + + align:start position:0% +complete our part I graph such that +there are n vertices whose parts sizes + + align:start position:0% +there are n vertices whose parts sizes + + + align:start position:0% +there are n vertices whose parts sizes +are all nearly the same up to at most + + align:start position:0% +are all nearly the same up to at most + + + align:start position:0% +are all nearly the same up to at most +one difference this is an example + + align:start position:0% +one difference this is an example + + + align:start position:0% +one difference this is an example +general maybe you have our part and just + + align:start position:0% +general maybe you have our part and just + + + align:start position:0% +general maybe you have our part and just +between different parts + + align:start position:0% + + + + align:start position:0% + +so it's not too hard to calculate the + + align:start position:0% +so it's not too hard to calculate the + + + align:start position:0% +so it's not too hard to calculate the +number of edges in such a graph and + + align:start position:0% +number of edges in such a graph and + + + align:start position:0% +number of edges in such a graph and +Torrens theorem tells us that that is + + align:start position:0% +Torrens theorem tells us that that is + + + align:start position:0% +Torrens theorem tells us that that is +the extreme example you cannot do better + + align:start position:0% +the extreme example you cannot do better + + + align:start position:0% +the extreme example you cannot do better +in terms of getting more edges at most + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +it's a generalization of meant helps + + align:start position:0% +it's a generalization of meant helps + + + align:start position:0% +it's a generalization of meant helps +term and you can think about if the + + align:start position:0% +term and you can think about if the + + + align:start position:0% +term and you can think about if the +proofs that we did for men tells them + + align:start position:0% +proofs that we did for men tells them + + + align:start position:0% +proofs that we did for men tells them +and generalizes to Torrance term and + + align:start position:0% +and generalizes to Torrance term and + + + align:start position:0% +and generalizes to Torrance term and +it's actually not entirely clear how to + + align:start position:0% +it's actually not entirely clear how to + + + align:start position:0% +it's actually not entirely clear how to +do it so let me present for you three + + align:start position:0% +do it so let me present for you three + + + align:start position:0% +do it so let me present for you three +three different proofs of Torrance + + align:start position:0% +three different proofs of Torrance + + + align:start position:0% +three different proofs of Torrance +theorem so some of them you can think + + align:start position:0% +theorem so some of them you can think + + + align:start position:0% +theorem so some of them you can think +about are they related to the proofs of + + align:start position:0% +about are they related to the proofs of + + + align:start position:0% +about are they related to the proofs of +mint house term that we did and they all + + align:start position:0% +mint house term that we did and they all + + + align:start position:0% +mint house term that we did and they all +are going to look somewhat different but + + align:start position:0% +are going to look somewhat different but + + + align:start position:0% +are going to look somewhat different but +maybe superficially the first proof we + + align:start position:0% +maybe superficially the first proof we + + + align:start position:0% +maybe superficially the first proof we +will use induction courtesies so this is + + align:start position:0% +will use induction courtesies so this is + + + align:start position:0% +will use induction courtesies so this is +one of very few times in this course + + align:start position:0% +one of very few times in this course + + + align:start position:0% +one of very few times in this course +where we will see induction so of course + + align:start position:0% +where we will see induction so of course + + + align:start position:0% +where we will see induction so of course +induction is a powerful technique in + + align:start position:0% +induction is a powerful technique in + + + align:start position:0% +induction is a powerful technique in +combinatorics but for almost the rest of + + align:start position:0% +combinatorics but for almost the rest of + + + align:start position:0% +combinatorics but for almost the rest of +the course we're not gonna have clean + + align:start position:0% +the course we're not gonna have clean + + + align:start position:0% +the course we're not gonna have clean +examples and when we do have clean + + align:start position:0% +examples and when we do have clean + + + align:start position:0% +examples and when we do have clean +examples to work with somehow increasing + + align:start position:0% +examples to work with somehow increasing + + + align:start position:0% +examples to work with somehow increasing +n by one doesn't buy you all that much + + align:start position:0% +n by one doesn't buy you all that much + + + align:start position:0% +n by one doesn't buy you all that much +here you know there are very clean + + align:start position:0% +here you know there are very clean + + + align:start position:0% +here you know there are very clean +examples very clean answers and + + align:start position:0% +examples very clean answers and + + + align:start position:0% +examples very clean answers and +induction works out quite well + + align:start position:0% + + + + align:start position:0% + +when n is small persue should always + + align:start position:0% +when n is small persue should always + + + align:start position:0% +when n is small persue should always +address that can come up with many funny + + align:start position:0% +address that can come up with many funny + + + align:start position:0% +address that can come up with many funny +proofs if you don't address small so any + + align:start position:0% +proofs if you don't address small so any + + + align:start position:0% +proofs if you don't address small so any +small this promise + + align:start position:0% +small this promise + + + align:start position:0% +small this promise +trivial and it's the most are you can + + align:start position:0% +trivial and it's the most are you can + + + align:start position:0% +trivial and it's the most are you can +have the complete graph on our vertices + + align:start position:0% +have the complete graph on our vertices + + + align:start position:0% +have the complete graph on our vertices +and then we're good so let's assume that + + align:start position:0% + + + + align:start position:0% + +we're not in this case and also by + + align:start position:0% +we're not in this case and also by + + + align:start position:0% +we're not in this case and also by +induction hypothesis let's assume that + + align:start position:0% +induction hypothesis let's assume that + + + align:start position:0% +induction hypothesis let's assume that +it is true for all graphs fewer than n + + align:start position:0% +it is true for all graphs fewer than n + + + align:start position:0% +it is true for all graphs fewer than n +vertices and let G be a graph that is K + + align:start position:0% +vertices and let G be a graph that is K + + + align:start position:0% +vertices and let G be a graph that is K +sub R plus 1 3 on n vertices and also + + align:start position:0% +sub R plus 1 3 on n vertices and also + + + align:start position:0% +sub R plus 1 3 on n vertices and also +let's assume a maximum example to begin + + align:start position:0% +let's assume a maximum example to begin + + + align:start position:0% +let's assume a maximum example to begin +with so let's assume that the G that you + + align:start position:0% +with so let's assume that the G that you + + + align:start position:0% +with so let's assume that the G that you +chose has already the maximum possible + + align:start position:0% +chose has already the maximum possible + + + align:start position:0% +chose has already the maximum possible +number of edges they're only finally + + align:start position:0% +number of edges they're only finally + + + align:start position:0% +number of edges they're only finally +such an example so pick one that already + + align:start position:0% +such an example so pick one that already + + + align:start position:0% +such an example so pick one that already +has the maximum number of edges and + + align:start position:0% +has the maximum number of edges and + + + align:start position:0% +has the maximum number of edges and +let's think about what properties this + + align:start position:0% +let's think about what properties this + + + align:start position:0% +let's think about what properties this +graph G has I claim that G must already + + align:start position:0% +graph G has I claim that G must already + + + align:start position:0% +graph G has I claim that G must already +contain a click on our vertices so think + + align:start position:0% +contain a click on our vertices so think + + + align:start position:0% +contain a click on our vertices so think +about that if G does not contain your + + align:start position:0% +about that if G does not contain your + + + align:start position:0% +about that if G does not contain your +click on our vertices then I can add in + + align:start position:0% +click on our vertices then I can add in + + + align:start position:0% +click on our vertices then I can add in +more edges and I can still maintain the + + align:start position:0% +more edges and I can still maintain the + + + align:start position:0% +more edges and I can still maintain the +property of being K sub R plus 1 so I + + align:start position:0% +property of being K sub R plus 1 so I + + + align:start position:0% +property of being K sub R plus 1 so I +can assume that G must contain a K sub R + + align:start position:0% +can assume that G must contain a K sub R + + + align:start position:0% +can assume that G must contain a K sub R +so let's look at one of these case of + + align:start position:0% +so let's look at one of these case of + + + align:start position:0% +so let's look at one of these case of +ours so let M be the vertices so our + + align:start position:0% +ours so let M be the vertices so our + + + align:start position:0% +ours so let M be the vertices so our +clique + + align:start position:0% + + + + align:start position:0% + +gee we have some a and the compliments + + align:start position:0% +gee we have some a and the compliments + + + align:start position:0% +gee we have some a and the compliments +that let me call that be alright look at + + align:start position:0% +that let me call that be alright look at + + + align:start position:0% +that let me call that be alright look at +the vertex in B how many neighbors can + + align:start position:0% +the vertex in B how many neighbors can + + + align:start position:0% +the vertex in B how many neighbors can +have in a it cannot be complete to a + + align:start position:0% +have in a it cannot be complete to a + + + align:start position:0% +have in a it cannot be complete to a +otherwise I would have an R plus 1 click + + align:start position:0% +otherwise I would have an R plus 1 click + + + align:start position:0% +otherwise I would have an R plus 1 click +so every vertex in B has at most R minus + + align:start position:0% +so every vertex in B has at most R minus + + + align:start position:0% +so every vertex in B has at most R minus +1 neighbors a so let's count all the + + align:start position:0% +1 neighbors a so let's count all the + + + align:start position:0% +1 neighbors a so let's count all the +edges the number of edges in G is that + + align:start position:0% +edges the number of edges in G is that + + + align:start position:0% +edges the number of edges in G is that +most or first which to account for the + + align:start position:0% +most or first which to account for the + + + align:start position:0% +most or first which to account for the +edges inside a and they are R choose two + + align:start position:0% +edges inside a and they are R choose two + + + align:start position:0% +edges inside a and they are R choose two +of them and then the edges between a and + + align:start position:0% +of them and then the edges between a and + + + align:start position:0% +of them and then the edges between a and +B for every vertex in B they are at most + + align:start position:0% +B for every vertex in B they are at most + + + align:start position:0% +B for every vertex in B they are at most +R minus 1 vertices going to a to each + + align:start position:0% +R minus 1 vertices going to a to each + + + align:start position:0% +R minus 1 vertices going to a to each +vertex and finally the edge set well we + + align:start position:0% +vertex and finally the edge set well we + + + align:start position:0% +vertex and finally the edge set well we +can say something more about these + + align:start position:0% +can say something more about these + + + align:start position:0% +can say something more about these +quantities we know that the size of B is + + align:start position:0% +quantities we know that the size of B is + + + align:start position:0% +quantities we know that the size of B is +exactly n minus R but what can we say + + align:start position:0% +exactly n minus R but what can we say + + + align:start position:0% +exactly n minus R but what can we say +about the number of edges in B we can + + align:start position:0% +about the number of edges in B we can + + + align:start position:0% +about the number of edges in B we can +use induction hypothesis P is also R + + align:start position:0% +use induction hypothesis P is also R + + + align:start position:0% +use induction hypothesis P is also R +plus 1 click free so the number of edges + + align:start position:0% +plus 1 click free so the number of edges + + + align:start position:0% +plus 1 click free so the number of edges +is that most the number of edges in the + + align:start position:0% +is that most the number of edges in the + + + align:start position:0% +is that most the number of edges in the +corresponding Terron graph now at this + + align:start position:0% +corresponding Terron graph now at this + + + align:start position:0% +corresponding Terron graph now at this +point you can do a calculation well I + + align:start position:0% +point you can do a calculation well I + + + align:start position:0% +point you can do a calculation well I +mean you should expect that the answer + + align:start position:0% +mean you should expect that the answer + + + align:start position:0% +mean you should expect that the answer +we're looking for is I mean this should + + align:start position:0% +we're looking for is I mean this should + + + align:start position:0% +we're looking for is I mean this should +be equal to the number of edges + + align:start position:0% +be equal to the number of edges + + + align:start position:0% +be equal to the number of edges +in the toronto f so you can either do a + + align:start position:0% +in the toronto f so you can either do a + + + align:start position:0% +in the toronto f so you can either do a +calculation to figure this out or + + align:start position:0% +calculation to figure this out or + + + align:start position:0% +calculation to figure this out or +remember what i said earlier that keep + + align:start position:0% +remember what i said earlier that keep + + + align:start position:0% +remember what i said earlier that keep +the type example in mind and everything + + align:start position:0% +the type example in mind and everything + + + align:start position:0% +the type example in mind and everything +should check out for a height example so + + align:start position:0% +should check out for a height example so + + + align:start position:0% +should check out for a height example so +in particular if you are in a situation + + align:start position:0% +in particular if you are in a situation + + + align:start position:0% +in particular if you are in a situation +of a complete multi-part a graph with + + align:start position:0% +of a complete multi-part a graph with + + + align:start position:0% +of a complete multi-part a graph with +equal size or nearly equal sized parts + + align:start position:0% +equal size or nearly equal sized parts + + + align:start position:0% +equal size or nearly equal sized parts +what is a a is one vertex from each part + + align:start position:0% + + + + align:start position:0% + +so you take out one vertex from each + + align:start position:0% +so you take out one vertex from each + + + align:start position:0% +so you take out one vertex from each +part and read off this calculation for + + align:start position:0% +part and read off this calculation for + + + align:start position:0% +part and read off this calculation for +this graph over here and then you see + + align:start position:0% +this graph over here and then you see + + + align:start position:0% +this graph over here and then you see +that that is indeed equality so you + + align:start position:0% +that that is indeed equality so you + + + align:start position:0% +that that is indeed equality so you +should check out you don't need to do + + align:start position:0% +should check out you don't need to do + + + align:start position:0% +should check out you don't need to do +any actual calculations ok any questions + + align:start position:0% +any actual calculations ok any questions + + + align:start position:0% +any actual calculations ok any questions +about the proofs we've done so far all + + align:start position:0% +about the proofs we've done so far all + + + align:start position:0% +about the proofs we've done so far all +right + + align:start position:0% +right + + + align:start position:0% +right +let me show you a another proof of + + align:start position:0% +let me show you a another proof of + + + align:start position:0% +let me show you a another proof of +Tehran's theorem so this proof is as a + + align:start position:0% +Tehran's theorem so this proof is as a + + + align:start position:0% +Tehran's theorem so this proof is as a +name so it's called Z cough + + align:start position:0% +name so it's called Z cough + + + align:start position:0% +name so it's called Z cough +symmetrization the capacity + + align:start position:0% +symmetrization the capacity + + + align:start position:0% +symmetrization the capacity +unfortunately only having a name that's + + align:start position:0% +unfortunately only having a name that's + + + align:start position:0% +unfortunately only having a name that's +hard to beat in terms of alphabetical + + align:start position:0% +hard to beat in terms of alphabetical + + + align:start position:0% +hard to beat in terms of alphabetical +watering if you and I were to write a + + align:start position:0% +watering if you and I were to write a + + + align:start position:0% +watering if you and I were to write a +paper I wouldn't be the last often ok so + + align:start position:0% +paper I wouldn't be the last often ok so + + + align:start position:0% +paper I wouldn't be the last often ok so +what's this about so let G be the graph + + align:start position:0% +what's this about so let G be the graph + + + align:start position:0% +what's this about so let G be the graph +again as before we're going to take a + + align:start position:0% +again as before we're going to take a + + + align:start position:0% +again as before we're going to take a +maximal example + + align:start position:0% +maximal example + + + align:start position:0% +maximal example +so be the end vertex graph that is free + + align:start position:0% +so be the end vertex graph that is free + + + align:start position:0% +so be the end vertex graph that is free +of clicks on R plus 1 vertices and has + + align:start position:0% +of clicks on R plus 1 vertices and has + + + align:start position:0% +of clicks on R plus 1 vertices and has +already the maximum number of edges so + + align:start position:0% +already the maximum number of edges so + + + align:start position:0% +already the maximum number of edges so +here's a property I want to prove about + + align:start position:0% +here's a property I want to prove about + + + align:start position:0% +here's a property I want to prove about +this graph I claim that if you look at + + align:start position:0% +this graph I claim that if you look at + + + align:start position:0% +this graph I claim that if you look at +the complement of the graph of this + + align:start position:0% +the complement of the graph of this + + + align:start position:0% +the complement of the graph of this +extremal example + + align:start position:0% +extremal example + + + align:start position:0% +extremal example +it must be an equivalence relation so + + align:start position:0% +it must be an equivalence relation so + + + align:start position:0% +it must be an equivalence relation so +more precisely claim that if XY is a non + + align:start position:0% +more precisely claim that if XY is a non + + + align:start position:0% +more precisely claim that if XY is a non +edge and Y Z is a non edge then X Z must + + align:start position:0% +edge and Y Z is a non edge then X Z must + + + align:start position:0% +edge and Y Z is a non edge then X Z must +also be a long edge so in other words + + align:start position:0% +also be a long edge so in other words + + + align:start position:0% +also be a long edge so in other words +non edges form equivalence relation + + align:start position:0% + + + + align:start position:0% + +and again you should always think about + + align:start position:0% +and again you should always think about + + + align:start position:0% +and again you should always think about +the extreme example it is true for the + + align:start position:0% +the extreme example it is true for the + + + align:start position:0% +the extreme example it is true for the +extremo example because the compliment + + align:start position:0% +extremo example because the compliment + + + align:start position:0% +extremo example because the compliment +are a bunch of clicks so it is an + + align:start position:0% +are a bunch of clicks so it is an + + + align:start position:0% +are a bunch of clicks so it is an +equivalence relation + + align:start position:0% + + + + align:start position:0% + +okay so let's prove this claim so let's + + align:start position:0% +okay so let's prove this claim so let's + + + align:start position:0% +okay so let's prove this claim so let's +assume that the conclusion is not true + + align:start position:0% +assume that the conclusion is not true + + + align:start position:0% +assume that the conclusion is not true +so suppose for the contrary that we have + + align:start position:0% +so suppose for the contrary that we have + + + align:start position:0% +so suppose for the contrary that we have +XY and Y Z being non edges but XZ is an + + align:start position:0% +XY and Y Z being non edges but XZ is an + + + align:start position:0% +XY and Y Z being non edges but XZ is an +edge so let's think about what happens + + align:start position:0% +edge so let's think about what happens + + + align:start position:0% +edge so let's think about what happens +to the degrees of knowledge isn't + + align:start position:0% +to the degrees of knowledge isn't + + + align:start position:0% +to the degrees of knowledge isn't +vertices so I claim that if the degree + + align:start position:0% +vertices so I claim that if the degree + + + align:start position:0% +vertices so I claim that if the degree +of Y or smaller than the degree of X + + align:start position:0% +of Y or smaller than the degree of X + + + align:start position:0% +of Y or smaller than the degree of X +then I can do something to the graph + + align:start position:0% +then I can do something to the graph + + + align:start position:0% +then I can do something to the graph +that violates the maximality of the + + align:start position:0% +that violates the maximality of the + + + align:start position:0% +that violates the maximality of the +number of edges namely I can replace Y + + align:start position:0% +number of edges namely I can replace Y + + + align:start position:0% +number of edges namely I can replace Y +by a chrome of X so I chop off Y from + + align:start position:0% +by a chrome of X so I chop off Y from + + + align:start position:0% +by a chrome of X so I chop off Y from +the graph and I look at X and I chrome + + align:start position:0% +the graph and I look at X and I chrome + + + align:start position:0% +the graph and I look at X and I chrome +it so calling it means taking some X + + align:start position:0% +it so calling it means taking some X + + + align:start position:0% +it so calling it means taking some X +Prime and a join X Prime to all the same + + align:start position:0% +Prime and a join X Prime to all the same + + + align:start position:0% +Prime and a join X Prime to all the same +neighbors as X so Chrome X into some + + align:start position:0% +neighbors as X so Chrome X into some + + + align:start position:0% +neighbors as X so Chrome X into some +other vertex X Prime now when you do + + align:start position:0% +other vertex X Prime now when you do + + + align:start position:0% +other vertex X Prime now when you do +this I claim that you also get a graph + + align:start position:0% +this I claim that you also get a graph + + + align:start position:0% +this I claim that you also get a graph +that is free of K sub R plus 1 so we + + align:start position:0% +that is free of K sub R plus 1 so we + + + align:start position:0% +that is free of K sub R plus 1 so we +also obtain + + align:start position:0% +also obtain + + + align:start position:0% +also obtain +a case up or plus one free graph case + + align:start position:0% +a case up or plus one free graph case + + + align:start position:0% +a case up or plus one free graph case +why is that if you were to have an R + + align:start position:0% +why is that if you were to have an R + + + align:start position:0% +why is that if you were to have an R +plus 1 Creek well it shouldn't have both + + align:start position:0% +plus 1 Creek well it shouldn't have both + + + align:start position:0% +plus 1 Creek well it shouldn't have both +X and X chrome because there's no edge + + align:start position:0% +X and X chrome because there's no edge + + + align:start position:0% +X and X chrome because there's no edge +between them so it only has one of X and + + align:start position:0% +between them so it only has one of X and + + + align:start position:0% +between them so it only has one of X and +X cloned but then that would have been a + + align:start position:0% +X cloned but then that would have been a + + + align:start position:0% +X cloned but then that would have been a +creek in the original graph however what + + align:start position:0% +creek in the original graph however what + + + align:start position:0% +creek in the original graph however what +about the number of edges that we obtain + + align:start position:0% +about the number of edges that we obtain + + + align:start position:0% +about the number of edges that we obtain +after this transformation if X had more + + align:start position:0% +after this transformation if X had more + + + align:start position:0% +after this transformation if X had more +outgoing edges a higher degree than Y + + align:start position:0% +outgoing edges a higher degree than Y + + + align:start position:0% +outgoing edges a higher degree than Y +then crowning X to replace Y increases + + align:start position:0% +then crowning X to replace Y increases + + + align:start position:0% +then crowning X to replace Y increases +the number of edges we obtain a graph + + align:start position:0% +the number of edges we obtain a graph + + + align:start position:0% +the number of edges we obtain a graph +that is also K sub R plus 1 and G which + + align:start position:0% +that is also K sub R plus 1 and G which + + + align:start position:0% +that is also K sub R plus 1 and G which +is not possible because we assume that G + + align:start position:0% +is not possible because we assume that G + + + align:start position:0% +is not possible because we assume that G +started with a maximum number of edges + + align:start position:0% +started with a maximum number of edges + + + align:start position:0% +started with a maximum number of edges +so therefore the degree of Y is that + + align:start position:0% +so therefore the degree of Y is that + + + align:start position:0% +so therefore the degree of Y is that +most the degree of X basically for every + + align:start position:0% +most the degree of X basically for every + + + align:start position:0% +most the degree of X basically for every +edge XY likewise we also have that + + align:start position:0% +edge XY likewise we also have that + + + align:start position:0% +edge XY likewise we also have that +there's no edge between y and z so the + + align:start position:0% +there's no edge between y and z so the + + + align:start position:0% +there's no edge between y and z so the +degree of y is we have wise and Easter + + align:start position:0% +degree of y is we have wise and Easter + + + align:start position:0% +degree of y is we have wise and Easter +the queer backs now so we have wives at + + align:start position:0% +the queer backs now so we have wives at + + + align:start position:0% +the queer backs now so we have wives at +least now Y has a lot of outgoing edges + + align:start position:0% +least now Y has a lot of outgoing edges + + + align:start position:0% +least now Y has a lot of outgoing edges +so now let's replace both x and z by + + align:start position:0% +so now let's replace both x and z by + + + align:start position:0% +so now let's replace both x and z by +Chrome's of Y + + align:start position:0% + + + + align:start position:0% + +as before we obtain some graph I will + + align:start position:0% +as before we obtain some graph I will + + + align:start position:0% +as before we obtain some graph I will +call G Prime and G Prime + + align:start position:0% +call G Prime and G Prime + + + align:start position:0% +call G Prime and G Prime +same reason as before is K sub R plus 1 + + align:start position:0% +same reason as before is K sub R plus 1 + + + align:start position:0% +same reason as before is K sub R plus 1 +3 right if you had a case of R plus 1 + + align:start position:0% +3 right if you had a case of R plus 1 + + + align:start position:0% +3 right if you had a case of R plus 1 +then the same clique should have shown + + align:start position:0% +then the same clique should have shown + + + align:start position:0% +then the same clique should have shown +up in G so so G prime does not have R + + align:start position:0% +up in G so so G prime does not have R + + + align:start position:0% +up in G so so G prime does not have R +plus 1 clicks either but what about the + + align:start position:0% +plus 1 clicks either but what about the + + + align:start position:0% +plus 1 clicks either but what about the +number of edges in G prime so the number + + align:start position:0% +number of edges in G prime so the number + + + align:start position:0% +number of edges in G prime so the number +of edges in G prime well we started with + + align:start position:0% +of edges in G prime well we started with + + + align:start position:0% +of edges in G prime well we started with +G we deleted X and Z so we deleted this + + align:start position:0% +G we deleted X and Z so we deleted this + + + align:start position:0% +G we deleted X and Z so we deleted this +many edges here were crucially using the + + align:start position:0% +many edges here were crucially using the + + + align:start position:0% +many edges here were crucially using the +fact that there is an edge between X and + + align:start position:0% +fact that there is an edge between X and + + + align:start position:0% +fact that there is an edge between X and +Z but now we also add it back in a bunch + + align:start position:0% +Z but now we also add it back in a bunch + + + align:start position:0% +Z but now we also add it back in a bunch +of edges coming from the chrome of Y and + + align:start position:0% +of edges coming from the chrome of Y and + + + align:start position:0% +of edges coming from the chrome of Y and +there are 2 times the Y edges added back + + align:start position:0% +there are 2 times the Y edges added back + + + align:start position:0% +there are 2 times the Y edges added back +in and see because Y has degree at least + + align:start position:0% +in and see because Y has degree at least + + + align:start position:0% +in and see because Y has degree at least +that of both X and Z we obtained that + + align:start position:0% +that of both X and Z we obtained that + + + align:start position:0% +that of both X and Z we obtained that +this number of edges is strictly bigger + + align:start position:0% +this number of edges is strictly bigger + + + align:start position:0% +this number of edges is strictly bigger +than that of G which contradicts the + + align:start position:0% +than that of G which contradicts the + + + align:start position:0% +than that of G which contradicts the +maximality of G + + align:start position:0% + + + + align:start position:0% + +so at this point we know that the + + align:start position:0% +so at this point we know that the + + + align:start position:0% +so at this point we know that the +complement of G must be an equivalence + + align:start position:0% +complement of G must be an equivalence + + + align:start position:0% +complement of G must be an equivalence +relation so the complement is a bunch of + + align:start position:0% +relation so the complement is a bunch of + + + align:start position:0% +relation so the complement is a bunch of +clicks and that's that's a lot of + + align:start position:0% +clicks and that's that's a lot of + + + align:start position:0% +clicks and that's that's a lot of +information right so that's almost the + + align:start position:0% +information right so that's almost the + + + align:start position:0% +information right so that's almost the +best thing we can hope for is a + + align:start position:0% +best thing we can hope for is a + + + align:start position:0% +best thing we can hope for is a +structural information we're not quite + + align:start position:0% +structural information we're not quite + + + align:start position:0% +structural information we're not quite +done yet and why is that almost there + + align:start position:0% +done yet and why is that almost there + + + align:start position:0% +done yet and why is that almost there +we're not quite done yet + + align:start position:0% + + + + align:start position:0% + +okay so we need to figure out the sizes + + align:start position:0% +okay so we need to figure out the sizes + + + align:start position:0% +okay so we need to figure out the sizes +of the individual parts so we need to + + align:start position:0% +of the individual parts so we need to + + + align:start position:0% +of the individual parts so we need to +figure out the sizes of individual parts + + align:start position:0% +figure out the sizes of individual parts + + + align:start position:0% +figure out the sizes of individual parts +and also note that you cannot have too + + align:start position:0% +and also note that you cannot have too + + + align:start position:0% +and also note that you cannot have too +many parts so at this point after the + + align:start position:0% +many parts so at this point after the + + + align:start position:0% +many parts so at this point after the +claim we know that G is a complete + + align:start position:0% +claim we know that G is a complete + + + align:start position:0% +claim we know that G is a complete +multi-part a graph it has and most are + + align:start position:0% +multi-part a graph it has and most are + + + align:start position:0% +multi-part a graph it has and most are +parts if it had R plus one parts I would + + align:start position:0% +parts if it had R plus one parts I would + + + align:start position:0% +parts if it had R plus one parts I would +see a clique and R plus 1 vertices if so + + align:start position:0% +see a clique and R plus 1 vertices if so + + + align:start position:0% +see a clique and R plus 1 vertices if so +and finally I need to show the rest is + + align:start position:0% +and finally I need to show the rest is + + + align:start position:0% +and finally I need to show the rest is +fairly routine I need to show what the + + align:start position:0% +fairly routine I need to show what the + + + align:start position:0% +fairly routine I need to show what the +part sizes have to be to maximize the + + align:start position:0% +part sizes have to be to maximize the + + + align:start position:0% +part sizes have to be to maximize the +number of edges and basically if you had + + align:start position:0% +number of edges and basically if you had + + + align:start position:0% +number of edges and basically if you had +some two parts so consider exactly our + + align:start position:0% +some two parts so consider exactly our + + + align:start position:0% +some two parts so consider exactly our +parts are all empty parts is some two + + align:start position:0% +parts are all empty parts is some two + + + align:start position:0% +parts are all empty parts is some two +parts half the number of vertices + + align:start position:0% +parts half the number of vertices + + + align:start position:0% +parts half the number of vertices +differing by more than one then what I + + align:start position:0% +differing by more than one then what I + + + align:start position:0% +differing by more than one then what I +can do is so if you had one part much + + align:start position:0% +can do is so if you had one part much + + + align:start position:0% +can do is so if you had one part much +bigger than the other part and imagine + + align:start position:0% +bigger than the other part and imagine + + + align:start position:0% +bigger than the other part and imagine +moving one vertex from one part to the + + align:start position:0% +moving one vertex from one part to the + + + align:start position:0% +moving one vertex from one part to the +other part and should convince yourself + + align:start position:0% +other part and should convince yourself + + + align:start position:0% +other part and should convince yourself +that this operation should strictly + + align:start position:0% +that this operation should strictly + + + align:start position:0% +that this operation should strictly +increase the number of edges + + align:start position:0% + + + + align:start position:0% + +moving vertices should strictly increase + + align:start position:0% +moving vertices should strictly increase + + + align:start position:0% +moving vertices should strictly increase +the number of edges of G and putting + + align:start position:0% +the number of edges of G and putting + + + align:start position:0% +the number of edges of G and putting +this all together we see that the + + align:start position:0% +this all together we see that the + + + align:start position:0% +this all together we see that the +extremal example necessarily has to be a + + align:start position:0% +extremal example necessarily has to be a + + + align:start position:0% +extremal example necessarily has to be a +current graph namely a complete our part + + align:start position:0% +current graph namely a complete our part + + + align:start position:0% +current graph namely a complete our part +i graph where all the parts have the + + align:start position:0% +i graph where all the parts have the + + + align:start position:0% +i graph where all the parts have the +same size up to almost one difference + + align:start position:0% + + + + align:start position:0% + +okay any questions so the question is + + align:start position:0% +okay any questions so the question is + + + align:start position:0% +okay any questions so the question is +can the zhukov symmetrization have been + + align:start position:0% +can the zhukov symmetrization have been + + + align:start position:0% +can the zhukov symmetrization have been +confused for any other types of problem + + align:start position:0% +confused for any other types of problem + + + align:start position:0% +confused for any other types of problem +I do have something else in mind but I + + align:start position:0% +I do have something else in mind but I + + + align:start position:0% +I do have something else in mind but I +don't want to discuss it now + + align:start position:0% + + + + align:start position:0% + +any more questions okay and you see that + + align:start position:0% +any more questions okay and you see that + + + align:start position:0% +any more questions okay and you see that +in both proofs were if you look at this + + align:start position:0% +in both proofs were if you look at this + + + align:start position:0% +in both proofs were if you look at this +proof as well you see that the tauren + + align:start position:0% +proof as well you see that the tauren + + + align:start position:0% +proof as well you see that the tauren +graph is the unique extra measure I want + + align:start position:0% +graph is the unique extra measure I want + + + align:start position:0% +graph is the unique extra measure I want +to give you a third proof that has a + + align:start position:0% +to give you a third proof that has a + + + align:start position:0% +to give you a third proof that has a +somewhat different flavor so these two + + align:start position:0% +somewhat different flavor so these two + + + align:start position:0% +somewhat different flavor so these two +proofs they're both somewhat + + align:start position:0% +proofs they're both somewhat + + + align:start position:0% +proofs they're both somewhat +combinatorial in flavor so I'm doing + + align:start position:0% +combinatorial in flavor so I'm doing + + + align:start position:0% +combinatorial in flavor so I'm doing +some arguments either looking at you + + align:start position:0% +some arguments either looking at you + + + align:start position:0% +some arguments either looking at you +know in this case you click and arguing + + align:start position:0% +know in this case you click and arguing + + + align:start position:0% +know in this case you click and arguing +what happens outside of it and over + + align:start position:0% +what happens outside of it and over + + + align:start position:0% +what happens outside of it and over +there again looking at Maximo example + + align:start position:0% +there again looking at Maximo example + + + align:start position:0% +there again looking at Maximo example +but the third proof I want to show is + + align:start position:0% +but the third proof I want to show is + + + align:start position:0% +but the third proof I want to show is +more of a probabilistic proof so this + + align:start position:0% +more of a probabilistic proof so this + + + align:start position:0% +more of a probabilistic proof so this +highlights an important method in + + align:start position:0% +highlights an important method in + + + align:start position:0% +highlights an important method in +combinatorics known as the probabilistic + + align:start position:0% +combinatorics known as the probabilistic + + + align:start position:0% +combinatorics known as the probabilistic +method where we start with a problem + + align:start position:0% +method where we start with a problem + + + align:start position:0% +method where we start with a problem +that comes with no randomness but we + + align:start position:0% +that comes with no randomness but we + + + align:start position:0% +that comes with no randomness but we +introduce some randomness to make the + + align:start position:0% +introduce some randomness to make the + + + align:start position:0% +introduce some randomness to make the +problem amenable and it's a very pretty + + align:start position:0% +problem amenable and it's a very pretty + + + align:start position:0% +problem amenable and it's a very pretty +idea + + align:start position:0% + + + + align:start position:0% + +so we start again with G being and n + + align:start position:0% +so we start again with G being and n + + + align:start position:0% +so we start again with G being and n +vertex K sub R plus one free well ommm + + align:start position:0% +vertex K sub R plus one free well ommm + + + align:start position:0% +vertex K sub R plus one free well ommm +edges and what I want to do is to + + align:start position:0% +edges and what I want to do is to + + + align:start position:0% +edges and what I want to do is to +randomly sort the vertex set consider a + + align:start position:0% +randomly sort the vertex set consider a + + + align:start position:0% +randomly sort the vertex set consider a +random order so I put all the vertices + + align:start position:0% +random order so I put all the vertices + + + align:start position:0% +random order so I put all the vertices +on the line where the vertices are + + align:start position:0% +on the line where the vertices are + + + align:start position:0% +on the line where the vertices are +chosen in random order and you see some + + align:start position:0% +chosen in random order and you see some + + + align:start position:0% +chosen in random order and you see some +of the edges + + align:start position:0% + + + + align:start position:0% + +let me show you how to find a click and + + align:start position:0% +let me show you how to find a click and + + + align:start position:0% +let me show you how to find a click and +essentially we do it in not so smart way + + align:start position:0% +essentially we do it in not so smart way + + + align:start position:0% +essentially we do it in not so smart way +namely I basically pick all the vertices + + align:start position:0% +namely I basically pick all the vertices + + + align:start position:0% +namely I basically pick all the vertices +in some greedy like manner where I + + align:start position:0% +in some greedy like manner where I + + + align:start position:0% +in some greedy like manner where I +include a vertex in my set if it is + + align:start position:0% +include a vertex in my set if it is + + + align:start position:0% +include a vertex in my set if it is +adjacent to all earlier vertices if if + + align:start position:0% +adjacent to all earlier vertices if if + + + align:start position:0% +adjacent to all earlier vertices if if +all of its neighbors so I include V if V + + align:start position:0% +all of its neighbors so I include V if V + + + align:start position:0% +all of its neighbors so I include V if V +is the earliest vertex + + align:start position:0% +is the earliest vertex + + + align:start position:0% +is the earliest vertex +among its neighbors okay so earliest + + align:start position:0% +among its neighbors okay so earliest + + + align:start position:0% +among its neighbors okay so earliest +means the leftmost go from left to right + + align:start position:0% +means the leftmost go from left to right + + + align:start position:0% +means the leftmost go from left to right +so in this case up here look at the + + align:start position:0% +so in this case up here look at the + + + align:start position:0% +so in this case up here look at the +first vertex well first of all taxes + + align:start position:0% +first vertex well first of all taxes + + + align:start position:0% +first vertex well first of all taxes +should always be in your set this vertex + + align:start position:0% +should always be in your set this vertex + + + align:start position:0% +should always be in your set this vertex +has one neighbors to the right that's + + align:start position:0% +has one neighbors to the right that's + + + align:start position:0% +has one neighbors to the right that's +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and no sorry that's not what I want to + + align:start position:0% +and no sorry that's not what I want to + + + align:start position:0% +and no sorry that's not what I want to +do so I actually do you mean when I was + + align:start position:0% +do so I actually do you mean when I was + + + align:start position:0% +do so I actually do you mean when I was +initially V is adjacent to all the + + align:start position:0% +initially V is adjacent to all the + + + align:start position:0% +initially V is adjacent to all the +earlier + + align:start position:0% + + + + align:start position:0% + +vertices in this order but so for + + align:start position:0% +vertices in this order but so for + + + align:start position:0% +vertices in this order but so for +example this vertex it's okay and I'm + + align:start position:0% +example this vertex it's okay and I'm + + + align:start position:0% +example this vertex it's okay and I'm +also going to include this vertex here + + align:start position:0% +also going to include this vertex here + + + align:start position:0% +also going to include this vertex here +yes it has both of its nativist earlier + + align:start position:0% +yes it has both of its nativist earlier + + + align:start position:0% +yes it has both of its nativist earlier +vertices are in in both the earlier + + align:start position:0% +vertices are in in both the earlier + + + align:start position:0% +vertices are in in both the earlier +vertices are adjacent to the third + + align:start position:0% +vertices are adjacent to the third + + + align:start position:0% +vertices are adjacent to the third +vertex and I think that's it now this + + align:start position:0% +vertex and I think that's it now this + + + align:start position:0% +vertex and I think that's it now this +set X I claim two things one that X has + + align:start position:0% +set X I claim two things one that X has + + + align:start position:0% +set X I claim two things one that X has +to be a clique so clean the X has to be + + align:start position:0% +to be a clique so clean the X has to be + + + align:start position:0% +to be a clique so clean the X has to be +a clique because every vertex in X is + + align:start position:0% +a clique because every vertex in X is + + + align:start position:0% +a clique because every vertex in X is +two jacent to the earlier vertices in + + align:start position:0% +two jacent to the earlier vertices in + + + align:start position:0% +two jacent to the earlier vertices in +particular all the vertices in X are + + align:start position:0% +particular all the vertices in X are + + + align:start position:0% +particular all the vertices in X are +joined to each other on the other hand + + align:start position:0% +joined to each other on the other hand + + + align:start position:0% +joined to each other on the other hand +how big is X at least in expectation so + + align:start position:0% +how big is X at least in expectation so + + + align:start position:0% +how big is X at least in expectation so +for every vertex I want to understand + + align:start position:0% +for every vertex I want to understand + + + align:start position:0% +for every vertex I want to understand +the probability that this V is included + + align:start position:0% +the probability that this V is included + + + align:start position:0% +the probability that this V is included +in X all right so V has a bunch of non + + align:start position:0% +in X all right so V has a bunch of non + + + align:start position:0% +in X all right so V has a bunch of non +neighbors and the property of being + + align:start position:0% +neighbors and the property of being + + + align:start position:0% +neighbors and the property of being +included in X is that all of its non + + align:start position:0% +included in X is that all of its non + + + align:start position:0% +included in X is that all of its non +neighbors up here after B so the + + align:start position:0% +neighbors up here after B so the + + + align:start position:0% +neighbors up here after B so the +probability that V little B is in the + + align:start position:0% +probability that V little B is in the + + + align:start position:0% +probability that V little B is in the +set X its equal to the probability that + + align:start position:0% +set X its equal to the probability that + + + align:start position:0% +set X its equal to the probability that +B appears before all its no neighbors + + align:start position:0% + + + + align:start position:0% + +all we and it's now neighbors they're + + align:start position:0% +all we and it's now neighbors they're + + + align:start position:0% +all we and it's now neighbors they're +sorted uniformly so the probability that + + align:start position:0% +sorted uniformly so the probability that + + + align:start position:0% +sorted uniformly so the probability that +this occurs is exactly one over one plus + + align:start position:0% +this occurs is exactly one over one plus + + + align:start position:0% +this occurs is exactly one over one plus +the number of non neighbors which is n + + align:start position:0% +the number of non neighbors which is n + + + align:start position:0% +the number of non neighbors which is n +minus the degree of P okay but we know + + align:start position:0% +minus the degree of P okay but we know + + + align:start position:0% +minus the degree of P okay but we know +that this graph G has no cliques of size + + align:start position:0% +that this graph G has no cliques of size + + + align:start position:0% +that this graph G has no cliques of size +R plus one so if we consider the + + align:start position:0% +R plus one so if we consider the + + + align:start position:0% +R plus one so if we consider the +expected number of size of X on one hand + + align:start position:0% +expected number of size of X on one hand + + + align:start position:0% +expected number of size of X on one hand +it has a most part because G 3 on the + + align:start position:0% +it has a most part because G 3 on the + + + align:start position:0% +it has a most part because G 3 on the +other hand by linearity of expectations + + align:start position:0% +other hand by linearity of expectations + + + align:start position:0% +other hand by linearity of expectations +for each vertex is included with some + + align:start position:0% +for each vertex is included with some + + + align:start position:0% +for each vertex is included with some +probability so the size of X in + + align:start position:0% +probability so the size of X in + + + align:start position:0% +probability so the size of X in +expectation is just the sum of all of + + align:start position:0% +expectation is just the sum of all of + + + align:start position:0% +expectation is just the sum of all of +these individual inclusion probabilities + + align:start position:0% +these individual inclusion probabilities + + + align:start position:0% +these individual inclusion probabilities +which individually we've computed above + + align:start position:0% + + + + align:start position:0% + +like that now by convexity I can + + align:start position:0% +like that now by convexity I can + + + align:start position:0% +like that now by convexity I can +conclude that this quantity this sum + + align:start position:0% +conclude that this quantity this sum + + + align:start position:0% +conclude that this quantity this sum +here is at least the content without + + align:start position:0% +here is at least the content without + + + align:start position:0% +here is at least the content without +would have been obtained if all the + + align:start position:0% +would have been obtained if all the + + + align:start position:0% +would have been obtained if all the +degrees were equal to each other and if + + align:start position:0% +degrees were equal to each other and if + + + align:start position:0% +degrees were equal to each other and if +you rearrange this equation this + + align:start position:0% +you rearrange this equation this + + + align:start position:0% +you rearrange this equation this +inequality we obtain most one minus one + + align:start position:0% +inequality we obtain most one minus one + + + align:start position:0% +inequality we obtain most one minus one +over R times N squared over two and if + + align:start position:0% +over R times N squared over two and if + + + align:start position:0% +over R times N squared over two and if +you compare this number to the number of + + align:start position:0% +you compare this number to the number of + + + align:start position:0% +you compare this number to the number of +edges in the current graph okay so you + + align:start position:0% +edges in the current graph okay so you + + + align:start position:0% +edges in the current graph okay so you +see that this is basically the number of + + align:start position:0% +see that this is basically the number of + + + align:start position:0% +see that this is basically the number of +edges and this gives you a proof and + + align:start position:0% +edges and this gives you a proof and + + + align:start position:0% +edges and this gives you a proof and +it's divisible by R and in fact the + + align:start position:0% +it's divisible by R and in fact the + + + align:start position:0% +it's divisible by R and in fact the +number of edges in the Terim graph is + + align:start position:0% +number of edges in the Terim graph is + + + align:start position:0% +number of edges in the Terim graph is +exactly this number here if this + + align:start position:0% +exactly this number here if this + + + align:start position:0% +exactly this number here if this +divisibility because condition is true + + align:start position:0% +divisibility because condition is true + + + align:start position:0% +divisibility because condition is true +if it's not you need to do a little bit + + align:start position:0% +if it's not you need to do a little bit + + + align:start position:0% +if it's not you need to do a little bit +more work because we were a little bit + + align:start position:0% +more work because we were a little bit + + + align:start position:0% +more work because we were a little bit +lost here this step right so you should + + align:start position:0% +lost here this step right so you should + + + align:start position:0% +lost here this step right so you should +see that this quantity here is minimized + + align:start position:0% +see that this quantity here is minimized + + + align:start position:0% +see that this quantity here is minimized +when all the degrees are roughly equal + + align:start position:0% +when all the degrees are roughly equal + + + align:start position:0% +when all the degrees are roughly equal +to each other and you make them as close + + align:start position:0% +to each other and you make them as close + + + align:start position:0% +to each other and you make them as close +to switch to each other as possible okay + + align:start position:0% +to switch to each other as possible okay + + + align:start position:0% +to switch to each other as possible okay +so with a little bit more work you can + + align:start position:0% +so with a little bit more work you can + + + align:start position:0% +so with a little bit more work you can +get the exact version of Tehran's + + align:start position:0% +get the exact version of Tehran's + + + align:start position:0% +get the exact version of Tehran's +theorem up there but at least what we've + + align:start position:0% +theorem up there but at least what we've + + + align:start position:0% +theorem up there but at least what we've +shown yes from here we've shown that the + + align:start position:0% +shown yes from here we've shown that the + + + align:start position:0% +shown yes from here we've shown that the +number of edges the number of edges is + + align:start position:0% +number of edges the number of edges is + + + align:start position:0% +number of edges the number of edges is +and most this quantity which for most + + align:start position:0% +and most this quantity which for most + + + align:start position:0% +and most this quantity which for most +purposes is basically as good as Torrens + + align:start position:0% +purposes is basically as good as Torrens + + + align:start position:0% +purposes is basically as good as Torrens +theorem okay any questions about this + + align:start position:0% +theorem okay any questions about this + + + align:start position:0% +theorem okay any questions about this +proof yet it's a probabilistic method + + align:start position:0% +proof yet it's a probabilistic method + + + align:start position:0% +proof yet it's a probabilistic method +proof so we're introducing some + + align:start position:0% +proof so we're introducing some + + + align:start position:0% +proof so we're introducing some +randomness into the problem that + + align:start position:0% +randomness into the problem that + + + align:start position:0% +randomness into the problem that +originally had no randomness in it okay + + align:start position:0% +originally had no randomness in it okay + + + align:start position:0% +originally had no randomness in it okay +great so let's take a very quick two + + align:start position:0% +great so let's take a very quick two + + + align:start position:0% +great so let's take a very quick two +minute break and then when we come back + + align:start position:0% +minute break and then when we come back + + + align:start position:0% +minute break and then when we come back +I want to show you that even though + + align:start position:0% +I want to show you that even though + + + align:start position:0% +I want to show you that even though +we've shown so many different proofs of + + align:start position:0% +we've shown so many different proofs of + + + align:start position:0% +we've shown so many different proofs of +Quran stir + + align:start position:0% +Quran stir + + + align:start position:0% +Quran stir +and Telstra might think okay this is a + + align:start position:0% +and Telstra might think okay this is a + + + align:start position:0% +and Telstra might think okay this is a +pretty simple thing even if I tweak the + + align:start position:0% +pretty simple thing even if I tweak the + + + align:start position:0% +pretty simple thing even if I tweak the +problem just a little bit there are so + + align:start position:0% +problem just a little bit there are so + + + align:start position:0% +problem just a little bit there are so +many things that we do not understand + + align:start position:0% +many things that we do not understand + + + align:start position:0% +many things that we do not understand +and many important open problems in + + align:start position:0% +and many important open problems in + + + align:start position:0% +and many important open problems in +combinatorics that are variants of + + align:start position:0% +combinatorics that are variants of + + + align:start position:0% +combinatorics that are variants of +Turin's theorem so let's take a quick + + align:start position:0% +Turin's theorem so let's take a quick + + + align:start position:0% +Turin's theorem so let's take a quick +break okay so so far we've been talking + + align:start position:0% +break okay so so far we've been talking + + + align:start position:0% +break okay so so far we've been talking +about + + align:start position:0% +about + + + align:start position:0% +about +Tehran's theorem or generally big + + align:start position:0% +Tehran's theorem or generally big + + + align:start position:0% +Tehran's theorem or generally big +problem of if you forbid a certain + + align:start position:0% +problem of if you forbid a certain + + + align:start position:0% +problem of if you forbid a certain +structure forbid a certain sub graph + + align:start position:0% +structure forbid a certain sub graph + + + align:start position:0% +structure forbid a certain sub graph +what is the maximum number of edges + + align:start position:0% +what is the maximum number of edges + + + align:start position:0% +what is the maximum number of edges +we're going to spend the next few + + align:start position:0% +we're going to spend the next few + + + align:start position:0% +we're going to spend the next few +lectures discussing more problems of + + align:start position:0% +lectures discussing more problems of + + + align:start position:0% +lectures discussing more problems of +that form and it turns out for the + + align:start position:0% +that form and it turns out for the + + + align:start position:0% +that form and it turns out for the +questions that we've the answers we've + + align:start position:0% +questions that we've the answers we've + + + align:start position:0% +questions that we've the answers we've +just seen they're deceptively simple and + + align:start position:0% +just seen they're deceptively simple and + + + align:start position:0% +just seen they're deceptively simple and +for almost any other situation we don't + + align:start position:0% +for almost any other situation we don't + + + align:start position:0% +for almost any other situation we don't +really know the exact answer and for + + align:start position:0% +really know the exact answer and for + + + align:start position:0% +really know the exact answer and for +many questions we don't know anything + + align:start position:0% +many questions we don't know anything + + + align:start position:0% +many questions we don't know anything +close to the truth I mean particularly I + + align:start position:0% +close to the truth I mean particularly I + + + align:start position:0% +close to the truth I mean particularly I +want to show you one variant of this + + align:start position:0% +want to show you one variant of this + + + align:start position:0% +want to show you one variant of this +problem namely what happens instead of + + align:start position:0% +problem namely what happens instead of + + + align:start position:0% +problem namely what happens instead of +looking at graphs if you look at hyper + + align:start position:0% +looking at graphs if you look at hyper + + + align:start position:0% +looking at graphs if you look at hyper +graphs and there that's a major open + + align:start position:0% +graphs and there that's a major open + + + align:start position:0% +graphs and there that's a major open +problem in combinatorics what the truth + + align:start position:0% +problem in combinatorics what the truth + + + align:start position:0% +problem in combinatorics what the truth +should be so here is an open problem + + align:start position:0% + + + + align:start position:0% + +which is what happens to Tehran's + + align:start position:0% +which is what happens to Tehran's + + + align:start position:0% +which is what happens to Tehran's +theorem for three scared by the word + + align:start position:0% +theorem for three scared by the word + + + align:start position:0% +theorem for three scared by the word +hyper graph we actually think of graphs + + align:start position:0% +hyper graph we actually think of graphs + + + align:start position:0% +hyper graph we actually think of graphs +as having edges consisting of pairs of + + align:start position:0% +as having edges consisting of pairs of + + + align:start position:0% +as having edges consisting of pairs of +vertices a hyper graph is simply a + + align:start position:0% +vertices a hyper graph is simply a + + + align:start position:0% +vertices a hyper graph is simply a +structure where three uniform hyper + + align:start position:0% +structure where three uniform hyper + + + align:start position:0% +structure where three uniform hyper +graph the edges are triples triples of + + align:start position:0% +graph the edges are triples triples of + + + align:start position:0% +graph the edges are triples triples of +vertices so question is what is the + + align:start position:0% +vertices so question is what is the + + + align:start position:0% +vertices so question is what is the +maximum number of triples + + align:start position:0% + + + + align:start position:0% + +in a graph without or for mental Sturm + + align:start position:0% +in a graph without or for mental Sturm + + + align:start position:0% +in a graph without or for mental Sturm +we asked what happens without a triangle + + align:start position:0% +we asked what happens without a triangle + + + align:start position:0% +we asked what happens without a triangle +for three uniform basic question you can + + align:start position:0% +for three uniform basic question you can + + + align:start position:0% +for three uniform basic question you can +ask is what about forbidding a + + align:start position:0% +ask is what about forbidding a + + + align:start position:0% +ask is what about forbidding a +tetrahedron so suppose you don't have + + align:start position:0% + + + + align:start position:0% + +four vertices such that every triple + + align:start position:0% +four vertices such that every triple + + + align:start position:0% +four vertices such that every triple +inside the four vertices is an edge + + align:start position:0% +inside the four vertices is an edge + + + align:start position:0% +inside the four vertices is an edge +what's the maximum number of edges you + + align:start position:0% +what's the maximum number of edges you + + + align:start position:0% +what's the maximum number of edges you +can have awaiting it's not so easy to + + align:start position:0% +can have awaiting it's not so easy to + + + align:start position:0% +can have awaiting it's not so easy to +come up with good examples so two runs + + align:start position:0% +come up with good examples so two runs + + + align:start position:0% +come up with good examples so two runs +to pick a bipartite graph complete + + align:start position:0% +to pick a bipartite graph complete + + + align:start position:0% +to pick a bipartite graph complete +bipartite graph well here it's not so + + align:start position:0% +bipartite graph well here it's not so + + + align:start position:0% +bipartite graph well here it's not so +easy to come up with examples but there + + align:start position:0% +easy to come up with examples but there + + + align:start position:0% +easy to come up with examples but there +are some examples and in fact Iran + + align:start position:0% +are some examples and in fact Iran + + + align:start position:0% +are some examples and in fact Iran +suggested the following construction + + align:start position:0% +suggested the following construction + + + align:start position:0% +suggested the following construction +namely you divide the set of vertices as + + align:start position:0% +namely you divide the set of vertices as + + + align:start position:0% +namely you divide the set of vertices as +before two three go for the equal sized + + align:start position:0% +before two three go for the equal sized + + + align:start position:0% +before two three go for the equal sized +parts and let me take all triples that + + align:start position:0% +parts and let me take all triples that + + + align:start position:0% +parts and let me take all triples that +look like one of the following forms + + align:start position:0% +look like one of the following forms + + + align:start position:0% +look like one of the following forms +either three vertices one in each vertex + + align:start position:0% +either three vertices one in each vertex + + + align:start position:0% +either three vertices one in each vertex +set or a triple looking like that two + + align:start position:0% +set or a triple looking like that two + + + align:start position:0% +set or a triple looking like that two +vertex in one set one in the next set + + align:start position:0% +vertex in one set one in the next set + + + align:start position:0% +vertex in one set one in the next set +we're going cyclically like that so I + + align:start position:0% +we're going cyclically like that so I + + + align:start position:0% +we're going cyclically like that so I +include all triples one of these forms + + align:start position:0% +include all triples one of these forms + + + align:start position:0% +include all triples one of these forms +and you should check that this + + align:start position:0% +and you should check that this + + + align:start position:0% +and you should check that this +construction has no cave has no + + align:start position:0% +construction has no cave has no + + + align:start position:0% +construction has no cave has no +tetrahedron if they had a tetrahedron it + + align:start position:0% +tetrahedron if they had a tetrahedron it + + + align:start position:0% +tetrahedron if they had a tetrahedron it +would have had at least two vertices in + + align:start position:0% +would have had at least two vertices in + + + align:start position:0% +would have had at least two vertices in +one part also then where the other two + + align:start position:0% +one part also then where the other two + + + align:start position:0% +one part also then where the other two +vertices can be + + align:start position:0% + + + + align:start position:0% + +so then how many edges does it have the + + align:start position:0% +so then how many edges does it have the + + + align:start position:0% +so then how many edges does it have the +exact number is not so important but + + align:start position:0% +exact number is not so important but + + + align:start position:0% +exact number is not so important but +what's important is that the edge + + align:start position:0% +what's important is that the edge + + + align:start position:0% +what's important is that the edge +density of all the possible triples the + + align:start position:0% +density of all the possible triples the + + + align:start position:0% +density of all the possible triples the +fraction of edges that are containing + + align:start position:0% +fraction of edges that are containing + + + align:start position:0% +fraction of edges that are containing +this construction is 5 9 and it is + + align:start position:0% +this construction is 5 9 and it is + + + align:start position:0% +this construction is 5 9 and it is +conjectured that this is open however + + align:start position:0% +conjectured that this is open however + + + align:start position:0% +conjectured that this is open however +we're quite far from proving this number + + align:start position:0% +we're quite far from proving this number + + + align:start position:0% +we're quite far from proving this number +so the best upper bound that that is + + align:start position:0% +so the best upper bound that that is + + + align:start position:0% +so the best upper bound that that is +currently available and it's found quite + + align:start position:0% +currently available and it's found quite + + + align:start position:0% +currently available and it's found quite +recently using this fairly new method in + + align:start position:0% +recently using this fairly new method in + + + align:start position:0% +recently using this fairly new method in +graph theory called flag algebras + + align:start position:0% +graph theory called flag algebras + + + align:start position:0% +graph theory called flag algebras +essentially a computerised way to try to + + align:start position:0% +essentially a computerised way to try to + + + align:start position:0% +essentially a computerised way to try to +prove such inequalities and the best + + align:start position:0% +prove such inequalities and the best + + + align:start position:0% +prove such inequalities and the best +upper bound is something like 0.56 2 and + + align:start position:0% +upper bound is something like 0.56 2 and + + + align:start position:0% +upper bound is something like 0.56 2 and +it's a major open problem to either + + align:start position:0% +it's a major open problem to either + + + align:start position:0% +it's a major open problem to either +prove or disprove that this construction + + align:start position:0% +prove or disprove that this construction + + + align:start position:0% +prove or disprove that this construction +here is the optimal one so you see even + + align:start position:0% +here is the optimal one so you see even + + + align:start position:0% +here is the optimal one so you see even +though I present there's so many proofs + + align:start position:0% +though I present there's so many proofs + + + align:start position:0% +though I present there's so many proofs +of mental state materials during my at + + align:start position:0% +of mental state materials during my at + + + align:start position:0% +of mental state materials during my at +this point hopefully they should all be + + align:start position:0% +this point hopefully they should all be + + + align:start position:0% +this point hopefully they should all be +you know seem quite simple in retrospect + + align:start position:0% +you know seem quite simple in retrospect + + + align:start position:0% +you know seem quite simple in retrospect +it's deceptive its deceptive and even if + + align:start position:0% +it's deceptive its deceptive and even if + + + align:start position:0% +it's deceptive its deceptive and even if +I change and tweak the problem just a + + align:start position:0% +I change and tweak the problem just a + + + align:start position:0% +I change and tweak the problem just a +little bit going to three uniform hyper + + align:start position:0% +little bit going to three uniform hyper + + + align:start position:0% +little bit going to three uniform hyper +graphs instead of graphs we really have + + align:start position:0% +graphs instead of graphs we really have + + + align:start position:0% +graphs instead of graphs we really have +no idea what's going on it's question + + align:start position:0% + + + + align:start position:0% + +okay so great the question is why do I + + align:start position:0% +okay so great the question is why do I + + + align:start position:0% +okay so great the question is why do I +say it's a pretty big gap so we know + + align:start position:0% +say it's a pretty big gap so we know + + + align:start position:0% +say it's a pretty big gap so we know +that there has to be some proportion of + + align:start position:0% +that there has to be some proportion of + + + align:start position:0% +that there has to be some proportion of +the total number of triples so well you + + align:start position:0% +the total number of triples so well you + + + align:start position:0% +the total number of triples so well you +have two numbers and out there they + + align:start position:0% +have two numbers and out there they + + + align:start position:0% +have two numbers and out there they +think I mean to me they seem pretty far + + align:start position:0% +think I mean to me they seem pretty far + + + align:start position:0% +think I mean to me they seem pretty far +apart it's not it's not some lower water + + align:start position:0% +apart it's not it's not some lower water + + + align:start position:0% +apart it's not it's not some lower water +gap so this is a first-order gap any + + align:start position:0% +gap so this is a first-order gap any + + + align:start position:0% +gap so this is a first-order gap any +more questions but it's true that later + + align:start position:0% +more questions but it's true that later + + + align:start position:0% +more questions but it's true that later +in the course we'll see gaps that are + + align:start position:0% +in the course we'll see gaps that are + + + align:start position:0% +in the course we'll see gaps that are +much bigger know we'll see gaps where it + + align:start position:0% +much bigger know we'll see gaps where it + + + align:start position:0% +much bigger know we'll see gaps where it +is like a polynomial on one side and a + + align:start position:0% +is like a polynomial on one side and a + + + align:start position:0% +is like a polynomial on one side and a +power of Exponential's on the other side + + align:start position:0% +power of Exponential's on the other side + + + align:start position:0% +power of Exponential's on the other side +and there I agree that's much worse so + + align:start position:0% +and there I agree that's much worse so + + + align:start position:0% +and there I agree that's much worse so +the gap is much bigger here it's just + + align:start position:0% +the gap is much bigger here it's just + + + align:start position:0% +the gap is much bigger here it's just +two numbers but you know in the worst + + align:start position:0% +two numbers but you know in the worst + + + align:start position:0% +two numbers but you know in the worst +case that can be two numbers anything + + align:start position:0% +case that can be two numbers anything + + + align:start position:0% +case that can be two numbers anything +any more questions + + align:start position:0% +any more questions + + + align:start position:0% +any more questions +okay so throughout this course I'll try + + align:start position:0% +okay so throughout this course I'll try + + + align:start position:0% +okay so throughout this course I'll try +to bring out some open problems and + + align:start position:0% +to bring out some open problems and + + + align:start position:0% +to bring out some open problems and +there are they are lost so I'll tell you + + align:start position:0% +there are they are lost so I'll tell you + + + align:start position:0% +there are they are lost so I'll tell you +what we do understand but most things we + + align:start position:0% +what we do understand but most things we + + + align:start position:0% +what we do understand but most things we +do not understand and hopefully you know + + align:start position:0% +do not understand and hopefully you know + + + align:start position:0% +do not understand and hopefully you know +some of you all go and try to understand + + align:start position:0% +some of you all go and try to understand + + + align:start position:0% +some of you all go and try to understand +them better so the next time I teach the + + align:start position:0% +them better so the next time I teach the + + + align:start position:0% +them better so the next time I teach the +course I can have something new to + + align:start position:0% +course I can have something new to + + + align:start position:0% +course I can have something new to +present okay so then we've so now that + + align:start position:0% +present okay so then we've so now that + + + align:start position:0% +present okay so then we've so now that +we've addressed the question of what's + + align:start position:0% +we've addressed the question of what's + + + align:start position:0% +we've addressed the question of what's +the maximum number of edges if you + + align:start position:0% +the maximum number of edges if you + + + align:start position:0% +the maximum number of edges if you +forbid a triangle or a clique the next + + align:start position:0% +forbid a triangle or a clique the next + + + align:start position:0% +forbid a triangle or a clique the next +natural thing to ask is what about if + + align:start position:0% +natural thing to ask is what about if + + + align:start position:0% +natural thing to ask is what about if +you forbid a general H so give me a + + align:start position:0% +you forbid a general H so give me a + + + align:start position:0% +you forbid a general H so give me a +graph H and what's the maximum number of + + align:start position:0% +graph H and what's the maximum number of + + + align:start position:0% +graph H and what's the maximum number of +edges if you're forbidden to do some + + align:start position:0% +edges if you're forbidden to do some + + + align:start position:0% +edges if you're forbidden to do some +notation so the extreme what the note by + + align:start position:0% +notation so the extreme what the note by + + + align:start position:0% +notation so the extreme what the note by +e^x and this is also called the Courant + + align:start position:0% +e^x and this is also called the Courant + + + align:start position:0% +e^x and this is also called the Courant +number sometimes because Curran serum + + align:start position:0% + + + + align:start position:0% + +hope you call it the extremal number or + + align:start position:0% +hope you call it the extremal number or + + + align:start position:0% +hope you call it the extremal number or +frequently so this number here is + + align:start position:0% +frequently so this number here is + + + align:start position:0% +frequently so this number here is +defined to be the maximum number of + + align:start position:0% +defined to be the maximum number of + + + align:start position:0% +defined to be the maximum number of +edges in an vertex graph containing + + align:start position:0% + + + + align:start position:0% + +I want to just clarify a piece of + + align:start position:0% +I want to just clarify a piece of + + + align:start position:0% +I want to just clarify a piece of +notation + + align:start position:0% +notation + + + align:start position:0% +notation +so when I say a sub graph so what do I + + align:start position:0% +so when I say a sub graph so what do I + + + align:start position:0% +so when I say a sub graph so what do I +mean so there are several notions of + + align:start position:0% +mean so there are several notions of + + + align:start position:0% +mean so there are several notions of +different kinds of sub graphs and the + + align:start position:0% +different kinds of sub graphs and the + + + align:start position:0% +different kinds of sub graphs and the +couple that come up + + align:start position:0% +couple that come up + + + align:start position:0% +couple that come up +somewhat frequently one is sub graph and + + align:start position:0% +somewhat frequently one is sub graph and + + + align:start position:0% +somewhat frequently one is sub graph and +then there's something called induced + + align:start position:0% +then there's something called induced + + + align:start position:0% +then there's something called induced +sub graph so probably easiest if I just + + align:start position:0% +sub graph so probably easiest if I just + + + align:start position:0% +sub graph so probably easiest if I just +show you an example suppose my H is the + + align:start position:0% +show you an example suppose my H is the + + + align:start position:0% +show you an example suppose my H is the +fourth cycle so an example of H being a + + align:start position:0% +fourth cycle so an example of H being a + + + align:start position:0% +fourth cycle so an example of H being a +sub graph is suppose I have this graph + + align:start position:0% +sub graph is suppose I have this graph + + + align:start position:0% +sub graph is suppose I have this graph +here so H is a sub graph of this graph + + align:start position:0% +here so H is a sub graph of this graph + + + align:start position:0% +here so H is a sub graph of this graph +here in many different ways but in + + align:start position:0% +here in many different ways but in + + + align:start position:0% +here in many different ways but in +particular like that but you see there + + align:start position:0% +particular like that but you see there + + + align:start position:0% +particular like that but you see there +are some more edges that are among the + + align:start position:0% +are some more edges that are among the + + + align:start position:0% +are some more edges that are among the +vertices but that's okay so sub graph + + align:start position:0% +vertices but that's okay so sub graph + + + align:start position:0% +vertices but that's okay so sub graph +only requires you to have a subset of + + align:start position:0% +only requires you to have a subset of + + + align:start position:0% +only requires you to have a subset of +vertices and a subset of edges whereas + + align:start position:0% +vertices and a subset of edges whereas + + + align:start position:0% +vertices and a subset of edges whereas +induced subgraphs this is not an example + + align:start position:0% +induced subgraphs this is not an example + + + align:start position:0% +induced subgraphs this is not an example +of induced sub graph so an induced sub + + align:start position:0% +of induced sub graph so an induced sub + + + align:start position:0% +of induced sub graph so an induced sub +graph means that you take the set of + + align:start position:0% +graph means that you take the set of + + + align:start position:0% +graph means that you take the set of +vertices and you look at all the edges + + align:start position:0% +vertices and you look at all the edges + + + align:start position:0% +vertices and you look at all the edges +in the big graph + + align:start position:0% +in the big graph + + + align:start position:0% +in the big graph +among your set of vertices so that's an + + align:start position:0% +among your set of vertices so that's an + + + align:start position:0% +among your set of vertices so that's an +induced sub graph so here the fourth + + align:start position:0% +induced sub graph so here the fourth + + + align:start position:0% +induced sub graph so here the fourth +cycle is an induced sub graph but not + + align:start position:0% +cycle is an induced sub graph but not + + + align:start position:0% +cycle is an induced sub graph but not +induced sub graph over here so I just + + align:start position:0% +induced sub graph over here so I just + + + align:start position:0% +induced sub graph over here so I just +want to make that distinction clear and + + align:start position:0% +want to make that distinction clear and + + + align:start position:0% +want to make that distinction clear and +for now in this chapter we'll only talk + + align:start position:0% +for now in this chapter we'll only talk + + + align:start position:0% +for now in this chapter we'll only talk +about sub graphs not induced necessarily + + align:start position:0% + + + + align:start position:0% + +all right so let's recap what happened + + align:start position:0% +all right so let's recap what happened + + + align:start position:0% +all right so let's recap what happened +for Terron still so Turin's theorem told + + align:start position:0% +for Terron still so Turin's theorem told + + + align:start position:0% +for Terron still so Turin's theorem told +us that the extremal number of these + + align:start position:0% +us that the extremal number of these + + + align:start position:0% +us that the extremal number of these +cliques well we know very precisely to + + align:start position:0% +cliques well we know very precisely to + + + align:start position:0% +cliques well we know very precisely to +be the number of edges in the tauren + + align:start position:0% +be the number of edges in the tauren + + + align:start position:0% +be the number of edges in the tauren +graph and in particular we saw from the + + align:start position:0% +graph and in particular we saw from the + + + align:start position:0% +graph and in particular we saw from the +last proof and also similarly if you + + align:start position:0% +last proof and also similarly if you + + + align:start position:0% +last proof and also similarly if you +just do a calculation that it is almost + + align:start position:0% +just do a calculation that it is almost + + + align:start position:0% +just do a calculation that it is almost +this quantity over here and it's + + align:start position:0% +this quantity over here and it's + + + align:start position:0% +this quantity over here and it's +basically that content so you can the + + align:start position:0% +basically that content so you can the + + + align:start position:0% +basically that content so you can the +number of edges in the strong graph is + + align:start position:0% +number of edges in the strong graph is + + + align:start position:0% +number of edges in the strong graph is +asymptotically that quantity up to and + + align:start position:0% +asymptotically that quantity up to and + + + align:start position:0% +asymptotically that quantity up to and +the basic question is what about general + + align:start position:0% +the basic question is what about general + + + align:start position:0% +the basic question is what about general +itch so if I give you some arbitrary + + align:start position:0% +itch so if I give you some arbitrary + + + align:start position:0% +itch so if I give you some arbitrary +graph H what can you tell me about the + + align:start position:0% +graph H what can you tell me about the + + + align:start position:0% +graph H what can you tell me about the +maximum number of edges in the graph + + align:start position:0% +maximum number of edges in the graph + + + align:start position:0% +maximum number of edges in the graph +forbidding this H as a sub graph and it + + align:start position:0% +forbidding this H as a sub graph and it + + + align:start position:0% +forbidding this H as a sub graph and it +turns out for most Atrus we have a + + align:start position:0% +turns out for most Atrus we have a + + + align:start position:0% +turns out for most Atrus we have a +pretty good understanding and perhaps + + align:start position:0% +pretty good understanding and perhaps + + + align:start position:0% +pretty good understanding and perhaps +quite surprisingly because you can + + align:start position:0% +quite surprisingly because you can + + + align:start position:0% +quite surprisingly because you can +imagine this problem looks like it might + + align:start position:0% +imagine this problem looks like it might + + + align:start position:0% +imagine this problem looks like it might +get quite complicated or all the proof + + align:start position:0% +get quite complicated or all the proof + + + align:start position:0% +get quite complicated or all the proof +that we've done are very specific to + + align:start position:0% +that we've done are very specific to + + + align:start position:0% +that we've done are very specific to +cliques but it turns out that we already + + align:start position:0% +cliques but it turns out that we already + + + align:start position:0% +cliques but it turns out that we already +understand a lot and the critical + + align:start position:0% +understand a lot and the critical + + + align:start position:0% +understand a lot and the critical +parameter that governs how this quantity + + align:start position:0% +parameter that governs how this quantity + + + align:start position:0% +parameter that governs how this quantity +behaves is the chromatic number of H + + align:start position:0% +behaves is the chromatic number of H + + + align:start position:0% +behaves is the chromatic number of H +so if you tell me the chromatic number + + align:start position:0% +so if you tell me the chromatic number + + + align:start position:0% +so if you tell me the chromatic number +of H I can already tell you quite a lot + + align:start position:0% +of H I can already tell you quite a lot + + + align:start position:0% +of H I can already tell you quite a lot +so just to remind you the chromatic + + align:start position:0% +so just to remind you the chromatic + + + align:start position:0% +so just to remind you the chromatic +number of a graph is the minimum number + + align:start position:0% +number of a graph is the minimum number + + + align:start position:0% +number of a graph is the minimum number +of colors you need to properly cover the + + align:start position:0% + + + + align:start position:0% + +H I H is the minimum number of colors + + align:start position:0% +H I H is the minimum number of colors + + + align:start position:0% +H I H is the minimum number of colors +needed to color the vertices of H so + + align:start position:0% +needed to color the vertices of H so + + + align:start position:0% +needed to color the vertices of H so +that no two adjacent vertices have the + + align:start position:0% +that no two adjacent vertices have the + + + align:start position:0% +that no two adjacent vertices have the +same color so for instance if I give you + + align:start position:0% +same color so for instance if I give you + + + align:start position:0% +same color so for instance if I give you +a clique R plus 1 vertices so all the + + align:start position:0% +a clique R plus 1 vertices so all the + + + align:start position:0% +a clique R plus 1 vertices so all the +vertices must receive different colors + + align:start position:0% +vertices must receive different colors + + + align:start position:0% +vertices must receive different colors +because every pair of vertices adjacent + + align:start position:0% +because every pair of vertices adjacent + + + align:start position:0% +because every pair of vertices adjacent +so the chromatic number is R plus 1 the + + align:start position:0% +so the chromatic number is R plus 1 the + + + align:start position:0% +so the chromatic number is R plus 1 the +chromatic number of the tauren graph + + align:start position:0% + + + + align:start position:0% + +it's our chromatic number of the Chiron + + align:start position:0% +it's our chromatic number of the Chiron + + + align:start position:0% +it's our chromatic number of the Chiron +graphics are I can color each part in + + align:start position:0% +graphics are I can color each part in + + + align:start position:0% +graphics are I can color each part in +this complete bipartite graph using a + + align:start position:0% +this complete bipartite graph using a + + + align:start position:0% +this complete bipartite graph using a +different color and that's the best I + + align:start position:0% +different color and that's the best I + + + align:start position:0% +different color and that's the best I +can do now if I have one graph being a + + align:start position:0% +can do now if I have one graph being a + + + align:start position:0% +can do now if I have one graph being a +sub graph of another graph what can you + + align:start position:0% +sub graph of another graph what can you + + + align:start position:0% +sub graph of another graph what can you +tell me about the relationships between + + align:start position:0% +tell me about the relationships between + + + align:start position:0% +tell me about the relationships between +their chromatic numbers if H there's a + + align:start position:0% +their chromatic numbers if H there's a + + + align:start position:0% +their chromatic numbers if H there's a +sub graph of G so what can you tell me + + align:start position:0% +sub graph of G so what can you tell me + + + align:start position:0% +sub graph of G so what can you tell me +about relationship between their + + align:start position:0% +about relationship between their + + + align:start position:0% +about relationship between their +chromatic numbers most high FG and why + + align:start position:0% +chromatic numbers most high FG and why + + + align:start position:0% +chromatic numbers most high FG and why +is that + + align:start position:0% + + + + align:start position:0% + +whatever coloring you do for G + + align:start position:0% +whatever coloring you do for G + + + align:start position:0% +whatever coloring you do for G +use the same coloring and that's a + + align:start position:0% +use the same coloring and that's a + + + align:start position:0% +use the same coloring and that's a +proper coloring for HS well so the + + align:start position:0% +proper coloring for HS well so the + + + align:start position:0% +proper coloring for HS well so the +chromatic number of H might be smaller + + align:start position:0% +chromatic number of H might be smaller + + + align:start position:0% +chromatic number of H might be smaller +but certainly cannot be bigger than that + + align:start position:0% +but certainly cannot be bigger than that + + + align:start position:0% +but certainly cannot be bigger than that +of G so in particular if you have a + + align:start position:0% +of G so in particular if you have a + + + align:start position:0% +of G so in particular if you have a +graph H with chromatic number or plus 1 + + align:start position:0% +graph H with chromatic number or plus 1 + + + align:start position:0% +graph H with chromatic number or plus 1 +then this Terron graph is always H 3 H + + align:start position:0% + + + + align:start position:0% + +requires 4 colors it cannot be embedded + + align:start position:0% +requires 4 colors it cannot be embedded + + + align:start position:0% +requires 4 colors it cannot be embedded +into the complete multi-part a graph on + + align:start position:0% +into the complete multi-part a graph on + + + align:start position:0% +into the complete multi-part a graph on +three parts so the turn graph is also an + + align:start position:0% +three parts so the turn graph is also an + + + align:start position:0% +three parts so the turn graph is also an +example of an H free graph with lots of + + align:start position:0% +example of an H free graph with lots of + + + align:start position:0% +example of an H free graph with lots of +edges and this tells us that the + + align:start position:0% +edges and this tells us that the + + + align:start position:0% +edges and this tells us that the +extremal number of H is at least that of + + align:start position:0% +extremal number of H is at least that of + + + align:start position:0% +extremal number of H is at least that of +the store number fine + + align:start position:0% +the store number fine + + + align:start position:0% +the store number fine +as one as the chromatic number minus one + + align:start position:0% +as one as the chromatic number minus one + + + align:start position:0% +as one as the chromatic number minus one +okay so that's some lower bound + + align:start position:0% +okay so that's some lower bound + + + align:start position:0% +okay so that's some lower bound +construction we saw earlier no we know + + align:start position:0% +construction we saw earlier no we know + + + align:start position:0% +construction we saw earlier no we know +what the asymptotic is it's like for the + + align:start position:0% +what the asymptotic is it's like for the + + + align:start position:0% +what the asymptotic is it's like for the +number of edges n goes to infinity and + + align:start position:0% +number of edges n goes to infinity and + + + align:start position:0% +number of edges n goes to infinity and +now the question is is this the right + + align:start position:0% +now the question is is this the right + + + align:start position:0% +now the question is is this the right +answer is it possible that we completely + + align:start position:0% +answer is it possible that we completely + + + align:start position:0% +answer is it possible that we completely +missed some construction that might + + align:start position:0% +missed some construction that might + + + align:start position:0% +missed some construction that might +produce a lot more edges and it turns + + align:start position:0% +produce a lot more edges and it turns + + + align:start position:0% +produce a lot more edges and it turns +out and I think this should be somewhat + + align:start position:0% +out and I think this should be somewhat + + + align:start position:0% +out and I think this should be somewhat +surprising because so far I feel like I + + align:start position:0% +surprising because so far I feel like I + + + align:start position:0% +surprising because so far I feel like I +haven't really told you anything oh + + align:start position:0% +haven't really told you anything oh + + + align:start position:0% +haven't really told you anything oh +that's surprising yet really mysterious + + align:start position:0% +that's surprising yet really mysterious + + + align:start position:0% +that's surprising yet really mysterious +from but it turns out that this is more + + align:start position:0% +from but it turns out that this is more + + + align:start position:0% +from but it turns out that this is more +or less the right answer so you cannot + + align:start position:0% +or less the right answer so you cannot + + + align:start position:0% +or less the right answer so you cannot +do much better than the tauren graph + + align:start position:0% + + + + align:start position:0% + +that for every graph H okay so if I fix + + align:start position:0% +that for every graph H okay so if I fix + + + align:start position:0% +that for every graph H okay so if I fix +H then the limit as n goes to infinity + + align:start position:0% +H then the limit as n goes to infinity + + + align:start position:0% +H then the limit as n goes to infinity +of the extremal number as a fraction of + + align:start position:0% +of the extremal number as a fraction of + + + align:start position:0% +of the extremal number as a fraction of +total number of pairs so here this is + + align:start position:0% +total number of pairs so here this is + + + align:start position:0% +total number of pairs so here this is +the edge density so this quantity here + + align:start position:0% +the edge density so this quantity here + + + align:start position:0% +the edge density so this quantity here +is equal to 1 minus Chi of H so 1 minus + + align:start position:0% +is equal to 1 minus Chi of H so 1 minus + + + align:start position:0% +is equal to 1 minus Chi of H so 1 minus +1 over Chi of H minus 1 so knowing the + + align:start position:0% +1 over Chi of H minus 1 so knowing the + + + align:start position:0% +1 over Chi of H minus 1 so knowing the +chromatic number in some sense + + align:start position:0% +chromatic number in some sense + + + align:start position:0% +chromatic number in some sense +completely determines how big the + + align:start position:0% +completely determines how big the + + + align:start position:0% +completely determines how big the +extremal number should be and you see + + align:start position:0% +extremal number should be and you see + + + align:start position:0% +extremal number should be and you see +that so far everything we've proved + + align:start position:0% +that so far everything we've proved + + + align:start position:0% +that so far everything we've proved +Tehran's theorem and house term agree + + align:start position:0% +Tehran's theorem and house term agree + + + align:start position:0% +Tehran's theorem and house term agree +with this formula here but if I give you + + align:start position:0% +with this formula here but if I give you + + + align:start position:0% +with this formula here but if I give you +some H may be quite complicated and + + align:start position:0% +some H may be quite complicated and + + + align:start position:0% +some H may be quite complicated and +those previous proofs don't work but + + align:start position:0% +those previous proofs don't work but + + + align:start position:0% +those previous proofs don't work but +still you know the first water has some + + align:start position:0% +still you know the first water has some + + + align:start position:0% +still you know the first water has some +tonics but there's still more to say but + + align:start position:0% +tonics but there's still more to say but + + + align:start position:0% +tonics but there's still more to say but +first let me just run through some + + align:start position:0% +first let me just run through some + + + align:start position:0% +first let me just run through some +examples for sanity check so if H is + + align:start position:0% +examples for sanity check so if H is + + + align:start position:0% +examples for sanity check so if H is +triangle H chromatic number and this + + align:start position:0% +triangle H chromatic number and this + + + align:start position:0% +triangle H chromatic number and this +limit so if H is the triangle chromatic + + align:start position:0% +limit so if H is the triangle chromatic + + + align:start position:0% +limit so if H is the triangle chromatic +number 3 is 1/2 and that's indeed the + + align:start position:0% +number 3 is 1/2 and that's indeed the + + + align:start position:0% +number 3 is 1/2 and that's indeed the +case that's what we did with mental + + align:start position:0% +case that's what we did with mental + + + align:start position:0% +case that's what we did with mental +Sturm if H is a clique of four vertices + + align:start position:0% +Sturm if H is a clique of four vertices + + + align:start position:0% +Sturm if H is a clique of four vertices +then the chromatic number is four and + + align:start position:0% +then the chromatic number is four and + + + align:start position:0% +then the chromatic number is four and +the answer is two-thirds and also that + + align:start position:0% +the answer is two-thirds and also that + + + align:start position:0% +the answer is two-thirds and also that +agrees with two runs to Greece with + + align:start position:0% +agrees with two runs to Greece with + + + align:start position:0% +agrees with two runs to Greece with +Tehran's theorem but I can give you some + + align:start position:0% +Tehran's theorem but I can give you some + + + align:start position:0% +Tehran's theorem but I can give you some +fairly complicated looking each so for + + align:start position:0% +fairly complicated looking each so for + + + align:start position:0% +fairly complicated looking each so for +example H might be the Peterson graph + + align:start position:0% + + + + align:start position:0% + +so every good graph theory course should + + align:start position:0% +so every good graph theory course should + + + align:start position:0% +so every good graph theory course should +feature Peterson graph at least once + + align:start position:0% +feature Peterson graph at least once + + + align:start position:0% +feature Peterson graph at least once +somewhere so that's the Peterson graph + + align:start position:0% +somewhere so that's the Peterson graph + + + align:start position:0% +somewhere so that's the Peterson graph +what's the chromatic number of the + + align:start position:0% +what's the chromatic number of the + + + align:start position:0% +what's the chromatic number of the +Peterson graph that's kind of a tricky + + align:start position:0% +Peterson graph that's kind of a tricky + + + align:start position:0% +Peterson graph that's kind of a tricky +question the last time I taught this + + align:start position:0% +question the last time I taught this + + + align:start position:0% +question the last time I taught this +course I even got the answer wrong so it + + align:start position:0% +course I even got the answer wrong so it + + + align:start position:0% +course I even got the answer wrong so it +turns out you can three color the + + align:start position:0% +turns out you can three color the + + + align:start position:0% +turns out you can three color the +Peterson graph okay so it's completely + + align:start position:0% +Peterson graph okay so it's completely + + + align:start position:0% +Peterson graph okay so it's completely +not obvious how to do this perfume oh + + align:start position:0% +not obvious how to do this perfume oh + + + align:start position:0% +not obvious how to do this perfume oh +there are only so many vertices if you + + align:start position:0% +there are only so many vertices if you + + + align:start position:0% +there are only so many vertices if you +stir it long enough you can you can see + + align:start position:0% +stir it long enough you can you can see + + + align:start position:0% +stir it long enough you can you can see +what happens but let me just show you a + + align:start position:0% +what happens but let me just show you a + + + align:start position:0% +what happens but let me just show you a +three coloring at the Peterson graph + + align:start position:0% + + + + align:start position:0% + +third color okay so that's a three + + align:start position:0% +third color okay so that's a three + + + align:start position:0% +third color okay so that's a three +coloring of the Peterson graph that's + + align:start position:0% +coloring of the Peterson graph that's + + + align:start position:0% +coloring of the Peterson graph that's +chromatic number three it's not - okay + + align:start position:0% +chromatic number three it's not - okay + + + align:start position:0% +chromatic number three it's not - okay +so why is it now - it's not bipartite as + + align:start position:0% +so why is it now - it's not bipartite as + + + align:start position:0% +so why is it now - it's not bipartite as +a five cycle which cannot be two colored + + align:start position:0% +a five cycle which cannot be two colored + + + align:start position:0% +a five cycle which cannot be two colored +so then the limit is one half and here I + + align:start position:0% +so then the limit is one half and here I + + + align:start position:0% +so then the limit is one half and here I +we can apply this theorem as a durstone + + align:start position:0% +we can apply this theorem as a durstone + + + align:start position:0% +we can apply this theorem as a durstone +small image and I think it should be + + align:start position:0% +small image and I think it should be + + + align:start position:0% +small image and I think it should be +somewhat surprising because the Peterson + + align:start position:0% +somewhat surprising because the Peterson + + + align:start position:0% +somewhat surprising because the Peterson +graph looks quite complicated if you try + + align:start position:0% +graph looks quite complicated if you try + + + align:start position:0% +graph looks quite complicated if you try +to forbid this graph in some big G it + + align:start position:0% +to forbid this graph in some big G it + + + align:start position:0% +to forbid this graph in some big G it +seems like it's kind of hard to do but + + align:start position:0% +seems like it's kind of hard to do but + + + align:start position:0% +seems like it's kind of hard to do but +it turns out the chromatic number + + align:start position:0% +it turns out the chromatic number + + + align:start position:0% +it turns out the chromatic number +completely governs the behavior of the + + align:start position:0% +completely governs the behavior of the + + + align:start position:0% +completely governs the behavior of the +extremal numbers but it turns out that's + + align:start position:0% +extremal numbers but it turns out that's + + + align:start position:0% +extremal numbers but it turns out that's +not the entire story because well this + + align:start position:0% +not the entire story because well this + + + align:start position:0% +not the entire story because well this +is quite a good deal and I said it gives + + align:start position:0% +is quite a good deal and I said it gives + + + align:start position:0% +is quite a good deal and I said it gives +you the first water asymptotics actually + + align:start position:0% +you the first water asymptotics actually + + + align:start position:0% +you the first water asymptotics actually +that's a lie it doesn't always give you + + align:start position:0% +that's a lie it doesn't always give you + + + align:start position:0% +that's a lie it doesn't always give you +the first water asymptotics and when is + + align:start position:0% +the first water asymptotics and when is + + + align:start position:0% +the first water asymptotics and when is +either strong shamone mesh not effective + + align:start position:0% +either strong shamone mesh not effective + + + align:start position:0% +either strong shamone mesh not effective +or rather it's not the complete it's not + + align:start position:0% +or rather it's not the complete it's not + + + align:start position:0% +or rather it's not the complete it's not +the final answer well you can say what + + align:start position:0% +the final answer well you can say what + + + align:start position:0% +the final answer well you can say what +about this little okay so that so we're + + align:start position:0% +about this little okay so that so we're + + + align:start position:0% +about this little okay so that so we're +still trying + + align:start position:0% +still trying + + + align:start position:0% +still trying +understand you know there is a limit and + + align:start position:0% +understand you know there is a limit and + + + align:start position:0% +understand you know there is a limit and +you can understand the one is the how + + align:start position:0% +you can understand the one is the how + + + align:start position:0% +you can understand the one is the how +quickly there's a converge to this + + align:start position:0% +quickly there's a converge to this + + + align:start position:0% +quickly there's a converge to this +number here okay so that's certainly a + + align:start position:0% +number here okay so that's certainly a + + + align:start position:0% +number here okay so that's certainly a +valid question but more importantly + + align:start position:0% +valid question but more importantly + + + align:start position:0% +valid question but more importantly +though if your graph is bipartite and + + align:start position:0% +though if your graph is bipartite and + + + align:start position:0% +though if your graph is bipartite and +all this theorem tells you is that the + + align:start position:0% +all this theorem tells you is that the + + + align:start position:0% +all this theorem tells you is that the +limit is equal to zero which somehow is + + align:start position:0% +limit is equal to zero which somehow is + + + align:start position:0% +limit is equal to zero which somehow is +not the most satisfying answer you want + + align:start position:0% +not the most satisfying answer you want + + + align:start position:0% +not the most satisfying answer you want +to know the first word there asymptotics + + align:start position:0% +to know the first word there asymptotics + + + align:start position:0% +to know the first word there asymptotics +I mean this still tells you something + + align:start position:0% +I mean this still tells you something + + + align:start position:0% +I mean this still tells you something +shamone master tells you that the + + align:start position:0% +shamone master tells you that the + + + align:start position:0% +shamone master tells you that the +extremal number is N squared of course + + align:start position:0% +extremal number is N squared of course + + + align:start position:0% +extremal number is N squared of course +you are a curious mathematician and you + + align:start position:0% +you are a curious mathematician and you + + + align:start position:0% +you are a curious mathematician and you +want to know really what is the + + align:start position:0% +want to know really what is the + + + align:start position:0% +want to know really what is the +asymptotics is it like n to the + + align:start position:0% +asymptotics is it like n to the + + + align:start position:0% +asymptotics is it like n to the +three-halves + + align:start position:0% +three-halves + + + align:start position:0% +three-halves +it's like n to the 4/3 you know what it + + align:start position:0% +it's like n to the 4/3 you know what it + + + align:start position:0% +it's like n to the 4/3 you know what it +this is not satisfying and it turns out + + align:start position:0% +this is not satisfying and it turns out + + + align:start position:0% +this is not satisfying and it turns out +from most bipartite graphs H it is a + + align:start position:0% +from most bipartite graphs H it is a + + + align:start position:0% +from most bipartite graphs H it is a +very difficult problem that we still do + + align:start position:0% +very difficult problem that we still do + + + align:start position:0% +very difficult problem that we still do +not know the answer to even what is the + + align:start position:0% +not know the answer to even what is the + + + align:start position:0% +not know the answer to even what is the +order of the asymptotics + + align:start position:0% +order of the asymptotics + + + align:start position:0% +order of the asymptotics +so the next few lectures what I want to + + align:start position:0% +so the next few lectures what I want to + + + align:start position:0% +so the next few lectures what I want to +do is to show you some techniques that + + align:start position:0% +do is to show you some techniques that + + + align:start position:0% +do is to show you some techniques that +will allow you to prove some upper + + align:start position:0% +will allow you to prove some upper + + + align:start position:0% +will allow you to prove some upper +bounds for this extremal number in the + + align:start position:0% +bounds for this extremal number in the + + + align:start position:0% +bounds for this extremal number in the +case when H is bipartite that shows you + + align:start position:0% +case when H is bipartite that shows you + + + align:start position:0% +case when H is bipartite that shows you +that the exponent can be less than two + + align:start position:0% +that the exponent can be less than two + + + align:start position:0% +that the exponent can be less than two +and I will also show you some + + align:start position:0% +and I will also show you some + + + align:start position:0% +and I will also show you some +constructions that sometimes but in the + + align:start position:0% +constructions that sometimes but in the + + + align:start position:0% +constructions that sometimes but in the +very few cases matches the upper bound + + align:start position:0% +very few cases matches the upper bound + + + align:start position:0% +very few cases matches the upper bound +so there are very few examples of graphs + + align:start position:0% +so there are very few examples of graphs + + + align:start position:0% +so there are very few examples of graphs +H from which we know the first order + + align:start position:0% +H from which we know the first order + + + align:start position:0% +H from which we know the first order +asymptotics and for most graph H it is + + align:start position:0% +asymptotics and for most graph H it is + + + align:start position:0% +asymptotics and for most graph H it is +their major open problems in common + + align:start position:0% +their major open problems in common + + + align:start position:0% +their major open problems in common +network and there's some really old ones + + align:start position:0% +network and there's some really old ones + + + align:start position:0% +network and there's some really old ones +which any solution might be quite + + align:start position:0% +which any solution might be quite + + + align:start position:0% +which any solution might be quite +exciting + + align:start position:0% + + + + align:start position:0% + +I will not show you a proof of + + align:start position:0% +I will not show you a proof of + + + align:start position:0% +I will not show you a proof of +Adderstone small image now we will see + + align:start position:0% +Adderstone small image now we will see + + + align:start position:0% +Adderstone small image now we will see +that later in the term once we've + + align:start position:0% +that later in the term once we've + + + align:start position:0% +that later in the term once we've +developed some more machinery although + + align:start position:0% +developed some more machinery although + + + align:start position:0% +developed some more machinery although +so later on in the term we'll see a + + align:start position:0% +so later on in the term we'll see a + + + align:start position:0% +so later on in the term we'll see a +proof using the so-called similarities + + align:start position:0% +proof using the so-called similarities + + + align:start position:0% +proof using the so-called similarities +regularity lemma which I've mentioned a + + align:start position:0% +regularity lemma which I've mentioned a + + + align:start position:0% +regularity lemma which I've mentioned a +few times in the first lecture although + + align:start position:0% +few times in the first lecture although + + + align:start position:0% +few times in the first lecture although +you don't actually need such heavy + + align:start position:0% +you don't actually need such heavy + + + align:start position:0% +you don't actually need such heavy +machinery so there is so the original + + align:start position:0% +machinery so there is so the original + + + align:start position:0% +machinery so there is so the original +proofs of errors in snow and stone first + + align:start position:0% +proofs of errors in snow and stone first + + + align:start position:0% +proofs of errors in snow and stone first +proved this result for H being a + + align:start position:0% +proved this result for H being a + + + align:start position:0% +proved this result for H being a +complete multi-part a graph and smaller + + align:start position:0% +complete multi-part a graph and smaller + + + align:start position:0% +complete multi-part a graph and smaller +which observed that knowing H for a + + align:start position:0% +which observed that knowing H for a + + + align:start position:0% +which observed that knowing H for a +complete multi-part I graph actually + + align:start position:0% +complete multi-part I graph actually + + + align:start position:0% +complete multi-part I graph actually +implies this result in general so you + + align:start position:0% +implies this result in general so you + + + align:start position:0% +implies this result in general so you +will not find a paper with all three of + + align:start position:0% +will not find a paper with all three of + + + align:start position:0% +will not find a paper with all three of +them in being authors so later on in the + + align:start position:0% +them in being authors so later on in the + + + align:start position:0% +them in being authors so later on in the +course once we've developed the + + align:start position:0% +course once we've developed the + + + align:start position:0% +course once we've developed the +machinery of graph regularity Lamas I + + align:start position:0% +machinery of graph regularity Lamas I + + + align:start position:0% +machinery of graph regularity Lamas I +will show you how you can deduce order + + align:start position:0% +will show you how you can deduce order + + + align:start position:0% +will show you how you can deduce order +stone simonova CH from Tehran's theorem + + align:start position:0% +stone simonova CH from Tehran's theorem + + + align:start position:0% +stone simonova CH from Tehran's theorem +somehow you use Tehran's theorem and + + align:start position:0% +somehow you use Tehran's theorem and + + + align:start position:0% +somehow you use Tehran's theorem and +bootstrap it to address stone Shimano + + align:start position:0% +bootstrap it to address stone Shimano + + + align:start position:0% +bootstrap it to address stone Shimano +venture so that should seem somewhat + + align:start position:0% +venture so that should seem somewhat + + + align:start position:0% +venture so that should seem somewhat +magical right so on one hand you have + + align:start position:0% +magical right so on one hand you have + + + align:start position:0% +magical right so on one hand you have +clicks and the other hand you have + + align:start position:0% +clicks and the other hand you have + + + align:start position:0% +clicks and the other hand you have +things that somehow don't have clicks + + align:start position:0% +things that somehow don't have clicks + + + align:start position:0% +things that somehow don't have clicks +they don't really look like clicks but + + align:start position:0% +they don't really look like clicks but + + + align:start position:0% +they don't really look like clicks but +you can still bootstrap one to the other + + align:start position:0% +you can still bootstrap one to the other + + + align:start position:0% +you can still bootstrap one to the other +and so after we develop some machinery + + align:start position:0% +and so after we develop some machinery + + + align:start position:0% +and so after we develop some machinery +won't do that but the earths are + + align:start position:0% +won't do that but the earths are + + + align:start position:0% +won't do that but the earths are +combinatorial proof which doesn't use + + align:start position:0% +combinatorial proof which doesn't use + + + align:start position:0% +combinatorial proof which doesn't use +any of this heavy machinery so you can I + + align:start position:0% +any of this heavy machinery so you can I + + + align:start position:0% +any of this heavy machinery so you can I +won't discuss it in this lecture but you + + align:start position:0% +won't discuss it in this lecture but you + + + align:start position:0% +won't discuss it in this lecture but you +can look it up and it's it's quite nice + + align:start position:0% +can look it up and it's it's quite nice + + + align:start position:0% +can look it up and it's it's quite nice +it has some combinatorial techniques and + + align:start position:0% +it has some combinatorial techniques and + + + align:start position:0% +it has some combinatorial techniques and +some double counting arguments I want to + + align:start position:0% +some double counting arguments I want to + + + align:start position:0% +some double counting arguments I want to +okay so going forward I want to show you + + align:start position:0% +okay so going forward I want to show you + + + align:start position:0% +okay so going forward I want to show you +some questions + + align:start position:0% +some questions + + + align:start position:0% +some questions +mostly questions but some answers as + + align:start position:0% +mostly questions but some answers as + + + align:start position:0% +mostly questions but some answers as +well so questions such as what is the + + align:start position:0% +well so questions such as what is the + + + align:start position:0% +well so questions such as what is the +extremal number of so what are some of + + align:start position:0% +extremal number of so what are some of + + + align:start position:0% +extremal number of so what are some of +the basic bipartite graphs one of them + + align:start position:0% +the basic bipartite graphs one of them + + + align:start position:0% +the basic bipartite graphs one of them +is just a complete bipartite graph so + + align:start position:0% +is just a complete bipartite graph so + + + align:start position:0% +is just a complete bipartite graph so +this for the 0 and k which problem and + + align:start position:0% +this for the 0 and k which problem and + + + align:start position:0% +this for the 0 and k which problem and +for some values of s and T we know the + + align:start position:0% +for some values of s and T we know the + + + align:start position:0% +for some values of s and T we know the +answer but for most values we have no + + align:start position:0% +answer but for most values we have no + + + align:start position:0% +answer but for most values we have no +idea what the answer is for + + align:start position:0% +idea what the answer is for + + + align:start position:0% +idea what the answer is for +4k4 for we do not know what is the + + align:start position:0% +4k4 for we do not know what is the + + + align:start position:0% +4k4 for we do not know what is the +correct exponent so even fairly small + + align:start position:0% +correct exponent so even fairly small + + + align:start position:0% +correct exponent so even fairly small +cases so this is all to show you that + + align:start position:0% +cases so this is all to show you that + + + align:start position:0% +cases so this is all to show you that +you know these simple proofs that we did + + align:start position:0% +you know these simple proofs that we did + + + align:start position:0% +you know these simple proofs that we did +today they are perhaps too deceptively + + align:start position:0% +today they are perhaps too deceptively + + + align:start position:0% +today they are perhaps too deceptively +simple even if you change the question a + + align:start position:0% +simple even if you change the question a + + + align:start position:0% +simple even if you change the question a +little bit we don't understand a lot so + + align:start position:0% +little bit we don't understand a lot so + + + align:start position:0% +little bit we don't understand a lot so +so questions like this will occupy the + + align:start position:0% +so questions like this will occupy the + + + align:start position:0% +so questions like this will occupy the +next several lectures and I also show + + align:start position:0% +next several lectures and I also show + + + align:start position:0% +next several lectures and I also show +you some constructions and there are + + align:start position:0% +you some constructions and there are + + + align:start position:0% +you some constructions and there are +some constructions that used nice + + align:start position:0% +some constructions that used nice + + + align:start position:0% +some constructions that used nice +algebraic ideas and some probabilistic + + align:start position:0% +algebraic ideas and some probabilistic + + + align:start position:0% +algebraic ideas and some probabilistic +idea so have see ideas coming from many + + align:start position:0% +idea so have see ideas coming from many + + + align:start position:0% +idea so have see ideas coming from many +different sources I want to close off by + + align:start position:0% +different sources I want to close off by + + + align:start position:0% +different sources I want to close off by +just a cultural remark so in this course + + align:start position:0% +just a cultural remark so in this course + + + align:start position:0% +just a cultural remark so in this course +especially the the first half will + + align:start position:0% +especially the the first half will + + + align:start position:0% +especially the the first half will +encounter a lot of Hungarian names we + + align:start position:0% +encounter a lot of Hungarian names we + + + align:start position:0% +encounter a lot of Hungarian names we +already thought a couple of them and I + + align:start position:0% +already thought a couple of them and I + + + align:start position:0% +already thought a couple of them and I +just want to give you a very quick + + align:start position:0% +just want to give you a very quick + + + align:start position:0% +just want to give you a very quick +tutorial on how to pronounce Hungarian + + align:start position:0% +tutorial on how to pronounce Hungarian + + + align:start position:0% +tutorial on how to pronounce Hungarian +names because for cultural purposes now + + align:start position:0% +names because for cultural purposes now + + + align:start position:0% +names because for cultural purposes now +in the past when I taught this class + + align:start position:0% +in the past when I taught this class + + + align:start position:0% +in the past when I taught this class +there were no Hungarian speakers but I + + align:start position:0% +there were no Hungarian speakers but I + + + align:start position:0% +there were no Hungarian speakers but I +think we do have at least one Hungarian + + align:start position:0% +think we do have at least one Hungarian + + + align:start position:0% +think we do have at least one Hungarian +speaker in the room so I want you but + + align:start position:0% +speaker in the room so I want you but + + + align:start position:0% +speaker in the room so I want you but +but you are native Hungarian speaker so + + align:start position:0% +but you are native Hungarian speaker so + + + align:start position:0% +but you are native Hungarian speaker so +you should tell us okay so can you + + align:start position:0% +you should tell us okay so can you + + + align:start position:0% +you should tell us okay so can you +pronounce help us pronounce these names + + align:start position:0% + + + + align:start position:0% + +this shamone yep + + align:start position:0% +this shamone yep + + + align:start position:0% +this shamone yep +so the one I'll just tell you two things + + align:start position:0% +so the one I'll just tell you two things + + + align:start position:0% +so the one I'll just tell you two things +about Hungarian names one of them is + + align:start position:0% +about Hungarian names one of them is + + + align:start position:0% +about Hungarian names one of them is +that the S it's pronounced like Shh and + + align:start position:0% +that the S it's pronounced like Shh and + + + align:start position:0% +that the S it's pronounced like Shh and +another thing that comes up is s Z which + + align:start position:0% +another thing that comes up is s Z which + + + align:start position:0% +another thing that comes up is s Z which +we saw in samurai D so this was + + align:start position:0% +we saw in samurai D so this was + + + align:start position:0% +we saw in samurai D so this was +pronounced like s forget the Z others + + align:start position:0% + + + + align:start position:0% + +another thing about a dish that you + + align:start position:0% +another thing about a dish that you + + + align:start position:0% +another thing about a dish that you +should know is that what is this accent + + align:start position:0% +should know is that what is this accent + + + align:start position:0% +should know is that what is this accent +it is not a double dot tag you would + + align:start position:0% +it is not a double dot tag you would + + + align:start position:0% +it is not a double dot tag you would +type it as / H just a few cultural + + align:start position:0% +type it as / H just a few cultural + + + align:start position:0% +type it as / H just a few cultural +remarks about about names okay great so + + align:start position:0% +remarks about about names okay great so + + + align:start position:0% +remarks about about names okay great so +we'll end today and then next time we'll + + align:start position:0% +we'll end today and then next time we'll + + + align:start position:0% +we'll end today and then next time we'll +start looking at other extremal numbers + + align:start position:0% +start looking at other extremal numbers + + + align:start position:0% +start looking at other extremal numbers +for more bipartite graphs \ No newline at end of file diff --git a/YwKqzngTcLw.txt b/YwKqzngTcLw.txt new file mode 100644 index 0000000000000000000000000000000000000000..bbaaaf6e12071d98849ef8009906c0b7cac7ce98 --- /dev/null +++ b/YwKqzngTcLw.txt @@ -0,0 +1,834 @@ +SPEAKER: The following content +is provided under a Creative + +Commons License. + +Your support will help MIT +OpenCourseWare continue to + +offer high quality educational +resources for free. + +To make a donation or view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +JOCELYN: Hi. + +Jocelyn here. + +And today we're going to go over +fall 2009's final exam, + +problem 10. + +As always we're going to start +by reading the question. + +You have 333 milliliters of +alkaline solution at a pH + +equal to 9.9. + +You wish to neutralize this +by reacting it with 222 + +milliliters of acid. + +What must be the value of +the pH of the acid? + +So first off let's write down +the information that was given + +and the information that +he's asking for. + +So we have 333 milliliters +of a solution + +with pH equal to 9.9. + +And he's asking you what must +the pH be if you want to put + +in 222 milliliters in order to +completely neutralize that + +basic solution. + +And the key here +is to recognize + +what neutralize means. + +And a neutralization is when you +take acid, or protons, and + +base and it reacts to +form water, thus + +creating a neutral solution. + +So the next step would probably +be to figure out how + +much excess hydroxide we +have in this solution. + +And then we can figure out how +much hydrogen we need to react + +with that hydroxide and to +form water in order to + +completely neutralize +this solution. + +So first step is to +find out what our + +concentration of OH minus is. + +And we do that by remembering +a few things + +about acid/base solutions. + +Right? + +We know that if you have the pH +plus the pOH it equals 14. + +And this is from the equilibrium +constant of this + +neutralization reaction. + +And then we can figure out what +the pOH is because we're + +given the pH of our +initial solution-- + +9.9-- + +and that equals 4.01. + +Now using the definition of +pOH, which is that the pOH + +equals the negative log of the +concentration of the OH minus, + +we can rearrange that and +get that our OH minus + +concentration equals 10 +to the negative pOH. + +Right? + +Just using our log +rules there. + +So this gives us that our +current concentration of the + +hydroxide ion is 10 to +the negative 4.1. + +That gives us the concentration +of the + +hydroxide, but what we really +want to know, if we're going + +to use our neutralization +reaction here, is we want to + +know how many moles +of hydroxide we + +have in that solution. + +And we can just do that +with stoichiometry. + +Right? + +The concentration is +in moles per liter. + +And we know-- + +so our moles hydroxide equals +our concentration, which is 10 + +to the negative 4.1 +moles per liter. + +Times-- + +if we want to get rid of that +liter unit we multiply it by + +our volume, which is 333 +milliliters, converting it + +from milliliters to liters. + +And this gives us 2.65 times 10 +to the negative 5 moles of + +OH minus in solution. + +So that's just the first +step of this problem. + +Now that we have the number of +moles of OH minus we need to + +find the number of moles of H +plus necessary to react with + +this excess hydroxide, and then +we will be able to find + +the concentration of hydrogen, +or protons, + +in that second solution. + +So first off we're going to +look at our neutralization + +reaction over here and realize +that it's a one-to-one + +stoichiometric ratio. + +That means in order to react +with 2.65 times 10 to the + +negative 5 moles of hydroxide, +we need the same number of + +moles of hydrogen. + +So over here I'm going to say +that this also equals the + +moles of H plus needed. + +All right. + +Now that we have our moles H +plus needed, we need to do the + +same process here +but in reverse. + +So first we need to find the +concentration of protons that + +we have. So given that we want +to only have 222 milliliters + +of this solution, right? + +So we have-- + +and we just divide that by +our volume, 0.222 liters. + +Right? + +Because we divide by 1,000 to +convert from milliliters. + +And that equals 1.19 +times 10 to the + +negative 4 moles per liter. + +So this is another problem where +you could get the answer + +but not actually be answering +the question. + +Right? + +Because this is the +concentration of protons that + +we need, but now we need +to convert that to pH. + +So moving over here we'll just +write the final steps. + +We know the definition of pH +is the negative log of the + +concentration. + +And so because we know the +concentration of protons we + +know that the-- + +we just need to plug this into +our calculator and we get our + +answer, which is a pH of 3.92. + +Put a box around that one +because it's our correct final + +answer, and you'll +be good to go for + +this part of the problem. + +Now moving on to part b we are +asked, name the conjugate base + +of each of the following. + +So we'll just start +part b right here. + +And the first thing to recognize +is what does a + +conjugate base mean. + +And in an acid/base pair, or +when you have a kind of + +dissociation of an acid, in the +most simple terms we can + +think about it just +losing a proton. + +In the leftover molecule, that's +the conjugate base + +right there. + +So in this problem we're asked +if the molecule loses a + +proton, what is the resulting +molecule? + +Ion, basically. + +So part i we have HPO4, and +that will dissociate to + +hydrogen phosphate ion. + +Simple enough. + +This is your conjugate base. + +So that's your answer +for part i. + +Moving to part ii. + +We have CH3NH3 plus. + +So it's kind of like an ammonia +ion but not quite-- + +sorry, ammonium. + +And we know that this +dissociates by losing a + +hydrogen off of the nitrogen, +because that's where the + +positive charge is. + +It makes more sense there. + +And we get-- + +sorry, keeping the same +order as above-- + +a proton plus. + +And this would be your +conjugate base. + +If you were a little bit +confused on this one it might + +help to draw the Lewis +structure, and you would see + +that the formal charge does +actually reside on nitrogen + +and, therefore, it makes +sense that the nitrogen + +would lose a proton. + +In addition, if you think about +the ammonia/ammonium ion + +relationship you know that you +have NH3 going to NH4. + +And in this case we just have +one of the hydrogens replaced + +with a methyl group, and so you +can make the analogy there + +that, oh, the hydrogen +would come from the + +nitrogen in that case. + +All right. + +So hopefully this was pretty +straightforward. + +As long as you're comfortable +with what a conjugate base is + +and what the dissociation +reactions look like for acids. + +So now on part c we are asked +to classify each of the + +following as a Lewis acid +or a Lewis base. + +Now first we need to remember +what a Lewis acid and + +a Lewis base are. + +So if you remember from lecture +or in your reading, we + +know that a Lewis acid is an +electron-pair acceptor and a + +Lewis base is an electron-pair +donor. + +These definitions are just a +little more general than the + +classic proton acceptor +or proton donor. + +The first part is asking us +about the cyanide ion. + +And to kind of clarify it for +yourself and because we're + +asked about Lewis acids and +bases, which are to deal with + +electron pairs, it might +be helpful to + +draw the Lewis structure. + +So for this molecule a good +Lewis structure looks like + +this, and it has a net +negative charge. + +And you can see that we have a +couple of lone electron pairs + +there that aren't involved +in bonding. + +And because it has a net +negative charge you can + +imagine that these electron +pairs would want to kind of + +grab onto something else that's +a little bit more + +electron positive. + +And because of that we +know that this is + +actually a Lewis base. + +It acts as a base and would grab +something like a proton + +and thus become more, I don't +know, stable in some cases. + +All right. + +Moving to part 2. + +We are asked about water, which +is a molecule that we + +deal a lot with in acid/base +chemistry. + +Again, you might be able to +answer this right off the bat, + +but we're going to look at +the Lewis structure here. + +Water has two lone pairs. + +So that means it could very +well act as a Lewis base. + +Hopefully that makes a +little bit of sense. + +Right? + +Because these electrons can go +and grab something like a + +proton and form the hydronium +ion with a positive charge, + +thus acting as a Lewis base. + +It's important to remember +that even though we're + +creating an acid in the +hydronium ion, this water + +molecule in converting to the +acid acts as a Lewis base. + +However, we also know that water +can lose a hydrogen and + +accepts those electrons to form +the hydroxide ion, and + +thus acts as a Lewis acid. + +So in the case of water either +Lewis acid or Lewis base was a + +correct answer in this case. + +Now moving on to part d. + +We will go over here, I think. + +I'm sorry. + +d, not b. + +Again, it's going to be +about acids and bases. + +Consider the effect each of the +following substances has + +on the ionization of the +weak base ammonia. + +For each state whether the +substance, one, suppresses + +ionization, two, enhances +ionization, or, three, has no + +effect on the ionization +of ammonia. + +In each instance give a reason +for your choice. + +Going back to the first part of +this question we see that + +it's asking us about the +ionization of ammonia. + +A good place to start from here +would be to write down + +the reaction, just so we have +that on our paper, in our + +mind, ready to think about it. + +So we have ammonia-- + +and aqueous means that +it's in water, right? + +And that is reacting +with water to form + +the ammonium ion-- + +sorry-- + +by adding a proton and +a hydroxide ion. + +OK. + +So this is the reaction +we're asked about. + +Now we need to look at each of +the three substances listed + +and decide how it affects +this ionization. + +So number i, we have KOH. + +Again, a good place to start +is to write what happens to + +potassium hydroxide when +it goes into water. + +And we know that KOH is +a strong base and will + +dissociate into potassium +plus hydroxide. + +So we see that it produces +hydroxide. + +And this should indicate to +you that, well, it has the + +same product as one of +the products of the + +ionization of ammonia. + +And if we remember back a +little bit before this + +section, we know that if you +have the same ion in solution + +it will definitely affect the +solubility, or ionization. + +So that's one way to think about +it, is that I now have a + +common ion effect that will, +because there's more hydroxide + +in solution now, it will push +this reaction, this + +equilibrium, back to the left. + +Another way to think +about that is + +Le Chatelier's Principle. + +Kind of the same thing, although +it's a little bit + +more versatile, I think, so +pretty easy to think about. + +Right? + +If you add a product +your reaction will + +shift to the left. + +If you add a reactant +your reaction will + +shift to the right. + +So here we're adding a product, +our reaction will + +shift to the left. + +Same as a common ion effect, +these two combine to decrease, + +or both suggest that we will +decrease, ionization. + +Moving to the second part +of this problem. + +We're asked about hydrogen +chloride. + +Again, let's look at what +that does in water. + +We know that it's a strong acid, +so it will dissociate + +into hydrogen, or protons, +and chloride. + +Now this one's a little bit +trickier because we don't have + +either of these ions in our +initial ionization reaction, + +but if we think about the fact +that ammonia is a weak base we + +can write an additional +ionization reaction. + +So that additional would be +ammonia reacting with a proton + +to form ammonium. + +Right? + +So this is another way +that the ammonia + +molecule would be ionized. + +And we can see that if we add +protons from this acidic + +molecule there we will increase +the ionization, + +because it will allow the +ammonia to work more as a base + +because of this reaction here. + +So we are increasing +ionization. + +Another way to think about this +is completely valid and + +kind of the same thing, but if +we look at this ionization + +reaction here where the +hydrogen chloride is + +dissociating into protons and +chlorides we can recognize + +that these protons will then +react with the hydroxide that + +is produced in the initial +ionization reaction. + +This will result in a decrease +of hydroxide + +in solution, right? + +And so by Le Chatelier's +Principle we know that a + +decrease in a product causes the +reaction to shift towards + +the product, to make +more hydroxide. + +So that's just another way of +thinking about the same + +process, and it results in the +same conclusion that addition + +of hydrogen chloride increases +the ionization of ammonia. + +OK. + +Moving to part iii. + +We have ammonium chloride, and +this will dissociate into + +ammonium and chloride. + +And even if you're not sure how +much it will dissociate, + +it will still dissociate +to some amount. + +So it will have at least a +little bit of an effect on our + +initial ionization reaction. + +So here we see the dissociation +produces ammonium + +ions, and just like the first +case that is one of the + +products in our ionization +reaction. + +And so Le Chatelier's Principle, +common ion effect, + +whatever you want to call it, +tells us that it will shift + +the equilibrium to the left +and decrease ionization. + +So with that we're done with +problem 10 from the final. + +It had a lot to do with +acid/bases, so hopefully you + +feel more comfortable with +them after this. \ No newline at end of file diff --git a/YwZYSTQs-Hk.txt b/YwZYSTQs-Hk.txt new file mode 100644 index 0000000000000000000000000000000000000000..82fedd03cd87dfe8b279ab6001ccb1fdb1a8a313 --- /dev/null +++ b/YwZYSTQs-Hk.txt @@ -0,0 +1,1787 @@ +align:start position:0% + +welcome back to recitation in this video + + align:start position:0% +welcome back to recitation in this video + + + align:start position:0% +welcome back to recitation in this video +what I'd like you to do is use leas + + align:start position:0% +what I'd like you to do is use leas + + + align:start position:0% +what I'd like you to do is use leas +squares to fit a line to the following + + align:start position:0% +squares to fit a line to the following + + + align:start position:0% +squares to fit a line to the following +data which includes three points the + + align:start position:0% +data which includes three points the + + + align:start position:0% +data which includes three points the +point 01 the point 21 and the point 34 + + align:start position:0% +point 01 the point 21 and the point 34 + + + align:start position:0% +point 01 the point 21 and the point 34 +and I've drawn a rough picture of where + + align:start position:0% +and I've drawn a rough picture of where + + + align:start position:0% +and I've drawn a rough picture of where +these points are on a graph and I'll + + align:start position:0% +these points are on a graph and I'll + + + align:start position:0% +these points are on a graph and I'll +I'll be talking a little bit about that + + align:start position:0% +I'll be talking a little bit about that + + + align:start position:0% +I'll be talking a little bit about that +after you give a uh try this problem so + + align:start position:0% +after you give a uh try this problem so + + + align:start position:0% +after you give a uh try this problem so +why don't you try to solve the problem + + align:start position:0% +why don't you try to solve the problem + + + align:start position:0% +why don't you try to solve the problem +based on the technique you learned in + + align:start position:0% +based on the technique you learned in + + + align:start position:0% +based on the technique you learned in +class and then bring the video back up + + align:start position:0% +class and then bring the video back up + + + align:start position:0% +class and then bring the video back up +I'll show you again what you're actually + + align:start position:0% +I'll show you again what you're actually + + + align:start position:0% +I'll show you again what you're actually +doing and then I will also solve the + + align:start position:0% +doing and then I will also solve the + + + align:start position:0% +doing and then I will also solve the +problem and you can see uh you can + + align:start position:0% +problem and you can see uh you can + + + align:start position:0% +problem and you can see uh you can +compare your answer to + + align:start position:0% + + + + align:start position:0% + +mine okay welcome back so the first + + align:start position:0% +mine okay welcome back so the first + + + align:start position:0% +mine okay welcome back so the first +thing I want to do when we're talking + + align:start position:0% +thing I want to do when we're talking + + + align:start position:0% +thing I want to do when we're talking +about least squares to fit a line to + + align:start position:0% +about least squares to fit a line to + + + align:start position:0% +about least squares to fit a line to +these data what I'd like to do is I'm + + align:start position:0% +these data what I'd like to do is I'm + + + align:start position:0% +these data what I'd like to do is I'm +going to draw a line on here and we're + + align:start position:0% +going to draw a line on here and we're + + + align:start position:0% +going to draw a line on here and we're +going to talk talk about what the Le + + align:start position:0% +going to talk talk about what the Le + + + align:start position:0% +going to talk talk about what the Le +squares actually is trying to do and so + + align:start position:0% +squares actually is trying to do and so + + + align:start position:0% +squares actually is trying to do and so +I'm going to draw this line say + + align:start position:0% +I'm going to draw this line say + + + align:start position:0% +I'm going to draw this line say +something like this and that's my first + + align:start position:0% +something like this and that's my first + + + align:start position:0% +something like this and that's my first +guess on what might be the uh the actual + + align:start position:0% +guess on what might be the uh the actual + + + align:start position:0% +guess on what might be the uh the actual +leas squares line for these data and if + + align:start position:0% +leas squares line for these data and if + + + align:start position:0% +leas squares line for these data and if +you recall what you're actually trying + + align:start position:0% +you recall what you're actually trying + + + align:start position:0% +you recall what you're actually trying +to do is you're trying to minimize a + + align:start position:0% +to do is you're trying to minimize a + + + align:start position:0% +to do is you're trying to minimize a +certain quantity and the Quant quantity + + align:start position:0% +certain quantity and the Quant quantity + + + align:start position:0% +certain quantity and the Quant quantity +you're trying to minimize is the + + align:start position:0% +you're trying to minimize is the + + + align:start position:0% +you're trying to minimize is the +difference between the the actual value + + align:start position:0% +difference between the the actual value + + + align:start position:0% +difference between the the actual value +you get and the expected value you get + + align:start position:0% +you get and the expected value you get + + + align:start position:0% +you get and the expected value you get +the square of that so this is one thing + + align:start position:0% +the square of that so this is one thing + + + align:start position:0% +the square of that so this is one thing +we're we're going to square so even + + align:start position:0% +we're we're going to square so even + + + align:start position:0% +we're we're going to square so even +pictorially we could say we have + + align:start position:0% +pictorially we could say we have + + + align:start position:0% +pictorially we could say we have +something + + align:start position:0% +something + + + align:start position:0% +something +that's that contributes some + + align:start position:0% +that's that contributes some + + + align:start position:0% +that's that contributes some +area Okay and then this is another thing + + align:start position:0% +area Okay and then this is another thing + + + align:start position:0% +area Okay and then this is another thing +it's a difference between the expected + + align:start position:0% +it's a difference between the expected + + + align:start position:0% +it's a difference between the expected +value in y and the actual value you + + align:start position:0% +value in y and the actual value you + + + align:start position:0% +value in y and the actual value you +get and so let me try and make that + + align:start position:0% +get and so let me try and make that + + + align:start position:0% +get and so let me try and make that +square because we square that value and + + align:start position:0% +square because we square that value and + + + align:start position:0% +square because we square that value and +then this last one is pretty small it's + + align:start position:0% +then this last one is pretty small it's + + + align:start position:0% +then this last one is pretty small it's +the difference between the expected + + align:start position:0% +the difference between the expected + + + align:start position:0% +the difference between the expected +value and the actual value is very small + + align:start position:0% +value and the actual value is very small + + + align:start position:0% +value and the actual value is very small +over in this this case from the picture + + align:start position:0% +over in this this case from the picture + + + align:start position:0% +over in this this case from the picture +I drew and so what you're trying to do + + align:start position:0% +I drew and so what you're trying to do + + + align:start position:0% +I drew and so what you're trying to do +is you're trying to find the line that + + align:start position:0% +is you're trying to find the line that + + + align:start position:0% +is you're trying to find the line that +minimizes the area of the sum of these + + align:start position:0% +minimizes the area of the sum of these + + + align:start position:0% +minimizes the area of the sum of these +three in this case three squares so if I + + align:start position:0% +three in this case three squares so if I + + + align:start position:0% +three in this case three squares so if I +you know if I tip the line down further + + align:start position:0% +you know if I tip the line down further + + + align:start position:0% +you know if I tip the line down further +here but I kept it kept it fixed there + + align:start position:0% +here but I kept it kept it fixed there + + + align:start position:0% +here but I kept it kept it fixed there +the area of this Square would get bigger + + align:start position:0% +the area of this Square would get bigger + + + align:start position:0% +the area of this Square would get bigger +because the the distance this distance + + align:start position:0% +because the the distance this distance + + + align:start position:0% +because the the distance this distance +would get bigger but of course the area + + align:start position:0% +would get bigger but of course the area + + + align:start position:0% +would get bigger but of course the area +of this Square would get smaller and so + + align:start position:0% +of this Square would get smaller and so + + + align:start position:0% +of this Square would get smaller and so +you're trying to figure out a way to + + align:start position:0% +you're trying to figure out a way to + + + align:start position:0% +you're trying to figure out a way to +optimize uh in this case minimize the + + align:start position:0% +optimize uh in this case minimize the + + + align:start position:0% +optimize uh in this case minimize the +area of these these + + align:start position:0% +area of these these + + + align:start position:0% +area of these these +sorry the sum of the areas of these + + align:start position:0% +sorry the sum of the areas of these + + + align:start position:0% +sorry the sum of the areas of these +squares by figuring out where to put the + + align:start position:0% +squares by figuring out where to put the + + + align:start position:0% +squares by figuring out where to put the +the line now I mentioned I would fix if + + align:start position:0% +the line now I mentioned I would fix if + + + align:start position:0% +the line now I mentioned I would fix if +I could fix this here and move it up and + + align:start position:0% +I could fix this here and move it up and + + + align:start position:0% +I could fix this here and move it up and +down and that would change the that + + align:start position:0% +down and that would change the that + + + align:start position:0% +down and that would change the that +would change the slope but fix the + + align:start position:0% +would change the slope but fix the + + + align:start position:0% +would change the slope but fix the +intercept but I could also move the + + align:start position:0% +intercept but I could also move the + + + align:start position:0% +intercept but I could also move the +intercept up and down and and uh I could + + align:start position:0% +intercept up and down and and uh I could + + + align:start position:0% +intercept up and down and and uh I could +slide the line up and down and that + + align:start position:0% +slide the line up and down and that + + + align:start position:0% +slide the line up and down and that +would fix the slope but uh vary The + + align:start position:0% +would fix the slope but uh vary The + + + align:start position:0% +would fix the slope but uh vary The +Intercept or I could do both and + + align:start position:0% +Intercept or I could do both and + + + align:start position:0% +Intercept or I could do both and +ultimately that's what you're doing + + align:start position:0% +ultimately that's what you're doing + + + align:start position:0% +ultimately that's what you're doing +you're trying to find the best Y + + align:start position:0% +you're trying to find the best Y + + + align:start position:0% +you're trying to find the best Y +intercept and the best slope at the same + + align:start position:0% +intercept and the best slope at the same + + + align:start position:0% +intercept and the best slope at the same +time and that's why you learned this + + align:start position:0% +time and that's why you learned this + + + align:start position:0% +time and that's why you learned this +process in multivariable calculus + + align:start position:0% +process in multivariable calculus + + + align:start position:0% +process in multivariable calculus +because you were trying to you're trying + + align:start position:0% +because you were trying to you're trying + + + align:start position:0% +because you were trying to you're trying +to optimize something that has two + + align:start position:0% +to optimize something that has two + + + align:start position:0% +to optimize something that has two +quantities that you can change you can + + align:start position:0% +quantities that you can change you can + + + align:start position:0% +quantities that you can change you can +change slope and you can change the Y + + align:start position:0% +change slope and you can change the Y + + + align:start position:0% +change slope and you can change the Y +intercept so that's why you learned it + + align:start position:0% +intercept so that's why you learned it + + + align:start position:0% +intercept so that's why you learned it +now instead of uh in single variable + + align:start position:0% +now instead of uh in single variable + + + align:start position:0% +now instead of uh in single variable +calculus now if we come over here I + + align:start position:0% +calculus now if we come over here I + + + align:start position:0% +calculus now if we come over here I +wrote down ahead of time what the + + align:start position:0% +wrote down ahead of time what the + + + align:start position:0% +wrote down ahead of time what the +equations are you get when you when you + + align:start position:0% +equations are you get when you when you + + + align:start position:0% +equations are you get when you when you +optimize uh when you're trying to + + align:start position:0% +optimize uh when you're trying to + + + align:start position:0% +optimize uh when you're trying to +optimize the least squares line so you + + align:start position:0% +optimize the least squares line so you + + + align:start position:0% +optimize the least squares line so you +write down you know the function as a + + align:start position:0% +write down you know the function as a + + + align:start position:0% +write down you know the function as a +function of a and b and you take the + + align:start position:0% +function of a and b and you take the + + + align:start position:0% +function of a and b and you take the +derivative with respect to a and you set + + align:start position:0% +derivative with respect to a and you set + + + align:start position:0% +derivative with respect to a and you set +it equal to zero you get the first + + align:start position:0% +it equal to zero you get the first + + + align:start position:0% +it equal to zero you get the first +equation when you take the derivative + + align:start position:0% +equation when you take the derivative + + + align:start position:0% +equation when you take the derivative +with respect to B and you set it equal + + align:start position:0% +with respect to B and you set it equal + + + align:start position:0% +with respect to B and you set it equal +to zero you get the second equation and + + align:start position:0% +to zero you get the second equation and + + + align:start position:0% +to zero you get the second equation and +so I'm just going to fill in the details + + align:start position:0% +so I'm just going to fill in the details + + + align:start position:0% +so I'm just going to fill in the details +and then tell you what the solution is + + align:start position:0% +and then tell you what the solution is + + + align:start position:0% +and then tell you what the solution is +and then I'm going to mention um a + + align:start position:0% +and then I'm going to mention um a + + + align:start position:0% +and then I'm going to mention um a +little more sophisticated thing we can + + align:start position:0% +little more sophisticated thing we can + + + align:start position:0% +little more sophisticated thing we can +do or I guess maybe the next level of uh + + align:start position:0% +do or I guess maybe the next level of uh + + + align:start position:0% +do or I guess maybe the next level of uh +of Le squares we can do that's not a + + align:start position:0% +of Le squares we can do that's not a + + + align:start position:0% +of Le squares we can do that's not a +linear problem so I'll do that last so + + align:start position:0% +linear problem so I'll do that last so + + + align:start position:0% +linear problem so I'll do that last so +what I want to do is I've put all the + + align:start position:0% +what I want to do is I've put all the + + + align:start position:0% +what I want to do is I've put all the +values I need over here on the right so + + align:start position:0% +values I need over here on the right so + + + align:start position:0% +values I need over here on the right so +all the values we need are on the right + + align:start position:0% +all the values we need are on the right + + + align:start position:0% +all the values we need are on the right +we're going to need the sum of all the X + + align:start position:0% +we're going to need the sum of all the X + + + align:start position:0% +we're going to need the sum of all the X +eyes and that's five the sum of all the + + align:start position:0% +eyes and that's five the sum of all the + + + align:start position:0% +eyes and that's five the sum of all the +Y eyes is six sum of the x i squares is + + align:start position:0% +Y eyes is six sum of the x i squares is + + + align:start position:0% +Y eyes is six sum of the x i squares is +13 and the sum of the x i Yi products is + + align:start position:0% +13 and the sum of the x i Yi products is + + + align:start position:0% +13 and the sum of the x i Yi products is +14 now where are these coming from + + align:start position:0% +14 now where are these coming from + + + align:start position:0% +14 now where are these coming from +remember what is x i and what is Yi if + + align:start position:0% +remember what is x i and what is Yi if + + + align:start position:0% +remember what is x i and what is Yi if +we come back over + + align:start position:0% +we come back over + + + align:start position:0% +we come back over +here this is X1 y1 X2 Y2 X3 Y3 okay so + + align:start position:0% +here this is X1 y1 X2 Y2 X3 Y3 okay so + + + align:start position:0% +here this is X1 y1 X2 Y2 X3 Y3 okay so +that's sort of how we get if we switch + + align:start position:0% +that's sort of how we get if we switch + + + align:start position:0% +that's sort of how we get if we switch +the if we switch the whole pairs around + + align:start position:0% +the if we switch the whole pairs around + + + align:start position:0% +the if we switch the whole pairs around +it doesn't matter matter obviously if we + + align:start position:0% +it doesn't matter matter obviously if we + + + align:start position:0% +it doesn't matter matter obviously if we +switched X and Y values together it does + + align:start position:0% +switched X and Y values together it does + + + align:start position:0% +switched X and Y values together it does +matter and that you see actually from + + align:start position:0% +matter and that you see actually from + + + align:start position:0% +matter and that you see actually from +the equation does matter right here you + + align:start position:0% +the equation does matter right here you + + + align:start position:0% +the equation does matter right here you +have a product of them so let me write + + align:start position:0% +have a product of them so let me write + + + align:start position:0% +have a product of them so let me write +this out and again we're solving for A + + align:start position:0% +this out and again we're solving for A + + + align:start position:0% +this out and again we're solving for A +and B so in this case a is the slope and + + align:start position:0% +and B so in this case a is the slope and + + + align:start position:0% +and B so in this case a is the slope and +B is The Intercept right so let me write + + align:start position:0% +B is The Intercept right so let me write + + + align:start position:0% +B is The Intercept right so let me write +everything in so we actually get that we + + align:start position:0% +everything in so we actually get that we + + + align:start position:0% +everything in so we actually get that we +want to solve the following system 13 a + + align:start position:0% +want to solve the following system 13 a + + + align:start position:0% +want to solve the following system 13 a ++ 5 b is equal to 14 + + align:start position:0% ++ 5 b is equal to 14 + + + align:start position:0% ++ 5 b is equal to 14 +make sure I put in everything correctly + + align:start position:0% +make sure I put in everything correctly + + + align:start position:0% +make sure I put in everything correctly +and then the second one is uh 5 a plus n + + align:start position:0% +and then the second one is uh 5 a plus n + + + align:start position:0% +and then the second one is uh 5 a plus n +in this case is three because there were + + align:start position:0% +in this case is three because there were + + + align:start position:0% +in this case is three because there were +three points plus + + align:start position:0% +three points plus + + + align:start position:0% +three points plus +3B is equal to 6 okay this is a system + + align:start position:0% +3B is equal to 6 okay this is a system + + + align:start position:0% +3B is equal to 6 okay this is a system +of equations it has two equations and + + align:start position:0% +of equations it has two equations and + + + align:start position:0% +of equations it has two equations and +two unknowns and if you solve this I + + align:start position:0% +two unknowns and if you solve this I + + + align:start position:0% +two unknowns and if you solve this I +should look at my notes because I didn't + + align:start position:0% +should look at my notes because I didn't + + + align:start position:0% +should look at my notes because I didn't +memorize it and I'm not going to do all + + align:start position:0% +memorize it and I'm not going to do all + + + align:start position:0% +memorize it and I'm not going to do all +the algebra if you go to solve this what + + align:start position:0% +the algebra if you go to solve this what + + + align:start position:0% +the algebra if you go to solve this what +you actually get is that a is equal to + + align:start position:0% +you actually get is that a is equal to + + + align:start position:0% +you actually get is that a is equal to +67 and B is equal to 47 so you get that + + align:start position:0% +67 and B is equal to 47 so you get that + + + align:start position:0% +67 and B is equal to 47 so you get that +the line let me write it here you get a + + align:start position:0% +the line let me write it here you get a + + + align:start position:0% +the line let me write it here you get a +is equal to + + align:start position:0% +is equal to + + + align:start position:0% +is equal to +67th and B is equal to + + align:start position:0% + + + + align:start position:0% + +47th okay and so what that tells you is + + align:start position:0% +47th okay and so what that tells you is + + + align:start position:0% +47th okay and so what that tells you is +if you come back over here the line we + + align:start position:0% +if you come back over here the line we + + + align:start position:0% +if you come back over here the line we +actually want I'll write the solution + + align:start position:0% +actually want I'll write the solution + + + align:start position:0% +actually want I'll write the solution +right here the line we actually want is + + align:start position:0% +right here the line we actually want is + + + align:start position:0% +right here the line we actually want is +the line Y = 67 + + align:start position:0% +the line Y = 67 + + + align:start position:0% +the line Y = 67 +x + 47 that is our least squares line + + align:start position:0% +x + 47 that is our least squares line + + + align:start position:0% +x + 47 that is our least squares line +that is our + + align:start position:0% +that is our + + + align:start position:0% +that is our +solution okay so that is actually + + align:start position:0% +solution okay so that is actually + + + align:start position:0% +solution okay so that is actually +solving for a line to fit these data you + + align:start position:0% +solving for a line to fit these data you + + + align:start position:0% +solving for a line to fit these data you +get the following solution but I want to + + align:start position:0% +get the following solution but I want to + + + align:start position:0% +get the following solution but I want to +point out and what we're going to do + + align:start position:0% +point out and what we're going to do + + + align:start position:0% +point out and what we're going to do +after this video there will be a a + + align:start position:0% +after this video there will be a a + + + align:start position:0% +after this video there will be a a +challenge problem to have you actually + + align:start position:0% +challenge problem to have you actually + + + align:start position:0% +challenge problem to have you actually +finish this I want to point out that you + + align:start position:0% +finish this I want to point out that you + + + align:start position:0% +finish this I want to point out that you +can actually also fit a higher degree + + align:start position:0% +can actually also fit a higher degree + + + align:start position:0% +can actually also fit a higher degree +polinomial to these data for instance + + align:start position:0% +polinomial to these data for instance + + + align:start position:0% +polinomial to these data for instance +you could try and use the technique of + + align:start position:0% +you could try and use the technique of + + + align:start position:0% +you could try and use the technique of +leas squares to fit a parabola to these + + align:start position:0% +leas squares to fit a parabola to these + + + align:start position:0% +leas squares to fit a parabola to these +data and let me point out what the + + align:start position:0% +data and let me point out what the + + + align:start position:0% +data and let me point out what the +function would look like in this case + + align:start position:0% +function would look like in this case + + + align:start position:0% +function would look like in this case +Okay so this is this is for the + + align:start position:0% +Okay so this is this is for the + + + align:start position:0% +Okay so this is this is for the +challenge + + align:start position:0% +challenge + + + align:start position:0% +challenge +problem for the challenge problem it now + + align:start position:0% +problem for the challenge problem it now + + + align:start position:0% +problem for the challenge problem it now +will be a function of three variables so + + align:start position:0% +will be a function of three variables so + + + align:start position:0% +will be a function of three variables so +it will look something like this we'll + + align:start position:0% +it will look something like this we'll + + + align:start position:0% +it will look something like this we'll +say a comma B comma C and the point we + + align:start position:0% +say a comma B comma C and the point we + + + align:start position:0% +say a comma B comma C and the point we +that we'll be wanting to minimize or the + + align:start position:0% +that we'll be wanting to minimize or the + + + align:start position:0% +that we'll be wanting to minimize or the +function will'll be wanting to minimize + + align:start position:0% +function will'll be wanting to minimize + + + align:start position:0% +function will'll be wanting to minimize +we're summing over I again from 1 to + + align:start position:0% +we're summing over I again from 1 to + + + align:start position:0% +we're summing over I again from 1 to +three I didn't write that down above but + + align:start position:0% +three I didn't write that down above but + + + align:start position:0% +three I didn't write that down above but +it was fairly obvious that that was what + + align:start position:0% +it was fairly obvious that that was what + + + align:start position:0% +it was fairly obvious that that was what +we were summing over the following thing + + align:start position:0% +we were summing over the following thing + + + align:start position:0% +we were summing over the following thing +we + + align:start position:0% +we + + + align:start position:0% +we +have Yi + + align:start position:0% +have Yi + + + align:start position:0% +have Yi +minus this big quantity a x i 2 + b x i + + align:start position:0% +minus this big quantity a x i 2 + b x i + + + align:start position:0% +minus this big quantity a x i 2 + b x i ++ C and we Square the whole thing and so + + align:start position:0% ++ C and we Square the whole thing and so + + + align:start position:0% ++ C and we Square the whole thing and so +what this is actually giving you is just + + align:start position:0% +what this is actually giving you is just + + + align:start position:0% +what this is actually giving you is just +as in the picture before this is giving + + align:start position:0% +as in the picture before this is giving + + + align:start position:0% +as in the picture before this is giving +you the difference between the expected + + align:start position:0% +you the difference between the expected + + + align:start position:0% +you the difference between the expected +value and the actual value so this is + + align:start position:0% +value and the actual value so this is + + + align:start position:0% +value and the actual value so this is +your actual y value and based on the + + align:start position:0% +your actual y value and based on the + + + align:start position:0% +your actual y value and based on the +parabola you're looking for what's in + + align:start position:0% +parabola you're looking for what's in + + + align:start position:0% +parabola you're looking for what's in +parth es is your expected y + + align:start position:0% +parth es is your expected y + + + align:start position:0% +parth es is your expected y +value right so this is actually this + + align:start position:0% +value right so this is actually this + + + align:start position:0% +value right so this is actually this +would actually be my Parabola when I + + align:start position:0% +would actually be my Parabola when I + + + align:start position:0% +would actually be my Parabola when I +evaluated at XI I get a number I get a + + align:start position:0% +evaluated at XI I get a number I get a + + + align:start position:0% +evaluated at XI I get a number I get a +value and that value will be on the + + align:start position:0% +value and that value will be on the + + + align:start position:0% +value and that value will be on the +parabola this will be the yvalue + + align:start position:0% +parabola this will be the yvalue + + + align:start position:0% +parabola this will be the yvalue +associated to the x value from the data + + align:start position:0% +associated to the x value from the data + + + align:start position:0% +associated to the x value from the data +so this is the actual value this is the + + align:start position:0% +so this is the actual value this is the + + + align:start position:0% +so this is the actual value this is the +expected value we take the difference + + align:start position:0% +expected value we take the difference + + + align:start position:0% +expected value we take the difference +and square it and because we want to + + align:start position:0% +and square it and because we want to + + + align:start position:0% +and square it and because we want to +minimize how we're going to solve this + + align:start position:0% +minimize how we're going to solve this + + + align:start position:0% +minimize how we're going to solve this +problem and this is what you'll have to + + align:start position:0% +problem and this is what you'll have to + + + align:start position:0% +problem and this is what you'll have to +do is just like with with the line uh + + align:start position:0% +do is just like with with the line uh + + + align:start position:0% +do is just like with with the line uh +situation you're going to take the + + align:start position:0% +situation you're going to take the + + + align:start position:0% +situation you're going to take the +derivative of this function with respect + + align:start position:0% +derivative of this function with respect + + + align:start position:0% +derivative of this function with respect +to each of these three variables + + align:start position:0% +to each of these three variables + + + align:start position:0% +to each of these three variables +separately so you'll take F sub a and + + align:start position:0% +separately so you'll take F sub a and + + + align:start position:0% +separately so you'll take F sub a and +then you'll set that equal to zero and + + align:start position:0% +then you'll set that equal to zero and + + + align:start position:0% +then you'll set that equal to zero and +then you'll take F subb you'll set that + + align:start position:0% +then you'll take F subb you'll set that + + + align:start position:0% +then you'll take F subb you'll set that +equal to zero and then you'll take F Sub + + align:start position:0% +equal to zero and then you'll take F Sub + + + align:start position:0% +equal to zero and then you'll take F Sub +C and you'll set that equal to zero + + align:start position:0% +C and you'll set that equal to zero + + + align:start position:0% +C and you'll set that equal to zero +again we set them all equal to zero + + align:start position:0% +again we set them all equal to zero + + + align:start position:0% +again we set them all equal to zero +because this is really an optimization + + align:start position:0% +because this is really an optimization + + + align:start position:0% +because this is really an optimization +problem we want to minimize something + + align:start position:0% +problem we want to minimize something + + + align:start position:0% +problem we want to minimize something +want to minimize this + + align:start position:0% +want to minimize this + + + align:start position:0% +want to minimize this +quantity so you take each of those three + + align:start position:0% +quantity so you take each of those three + + + align:start position:0% +quantity so you take each of those three +derivatives partial derivatives set them + + align:start position:0% +derivatives partial derivatives set them + + + align:start position:0% +derivatives partial derivatives set them +equal to zero and you have a system of + + align:start position:0% +equal to zero and you have a system of + + + align:start position:0% +equal to zero and you have a system of +three equations with three variables and + + align:start position:0% +three equations with three variables and + + + align:start position:0% +three equations with three variables and +you know how to solve such a system by + + align:start position:0% +you know how to solve such a system by + + + align:start position:0% +you know how to solve such a system by +using matrices for instance that would + + align:start position:0% +using matrices for instance that would + + + align:start position:0% +using matrices for instance that would +be one way to solve such a system and so + + align:start position:0% +be one way to solve such a system and so + + + align:start position:0% +be one way to solve such a system and so +then you can actually come up with a + + align:start position:0% +then you can actually come up with a + + + align:start position:0% +then you can actually come up with a +formula uh for the the sort of Parabola + + align:start position:0% +formula uh for the the sort of Parabola + + + align:start position:0% +formula uh for the the sort of Parabola +of best fit you could think of it as and + + align:start position:0% +of best fit you could think of it as and + + + align:start position:0% +of best fit you could think of it as and +so I'm going to stop there because I + + align:start position:0% +so I'm going to stop there because I + + + align:start position:0% +so I'm going to stop there because I +think from here you guys will do it but + + align:start position:0% +think from here you guys will do it but + + + align:start position:0% +think from here you guys will do it but +I just want to point out this is where + + align:start position:0% +I just want to point out this is where + + + align:start position:0% +I just want to point out this is where +you're going to be starting this next + + align:start position:0% +you're going to be starting this next + + + align:start position:0% +you're going to be starting this next +sort of challenge problem to find the + + align:start position:0% +sort of challenge problem to find the + + + align:start position:0% +sort of challenge problem to find the +quadratic of best fit for these three + + align:start position:0% +quadratic of best fit for these three + + + align:start position:0% +quadratic of best fit for these three +data points so that's where I'll end it \ No newline at end of file diff --git a/ZQu2B3GyI_k.txt b/ZQu2B3GyI_k.txt new file mode 100644 index 0000000000000000000000000000000000000000..d55c6d9006cfec1ac009ef9f6c0df9642d38cd84 --- /dev/null +++ b/ZQu2B3GyI_k.txt @@ -0,0 +1,15219 @@ +align:start position:0% + +fortunately I have a + + align:start position:0% +fortunately I have a + + + align:start position:0% +fortunately I have a +today dr. Adam Wright who will be doing + + align:start position:0% +today dr. Adam Wright who will be doing + + + align:start position:0% +today dr. Adam Wright who will be doing +an interview style session and will + + align:start position:0% +an interview style session and will + + + align:start position:0% +an interview style session and will +answer questions for you this is Adams + + align:start position:0% +answer questions for you this is Adams + + + align:start position:0% +answer questions for you this is Adams +sort of bread and butter is exactly how + + align:start position:0% +sort of bread and butter is exactly how + + + align:start position:0% +sort of bread and butter is exactly how +to translate this kind of technology + + align:start position:0% +to translate this kind of technology + + + align:start position:0% +to translate this kind of technology +into into the clinic he's currently in + + align:start position:0% +into into the clinic he's currently in + + + align:start position:0% +into into the clinic he's currently in +the partner system at the Brigham I + + align:start position:0% +the partner system at the Brigham I + + + align:start position:0% +the partner system at the Brigham I +guess but he's about to become a traitor + + align:start position:0% +guess but he's about to become a traitor + + + align:start position:0% +guess but he's about to become a traitor +and leave us in Boston and and occupy a + + align:start position:0% +and leave us in Boston and and occupy a + + + align:start position:0% +and leave us in Boston and and occupy a +position at Vanderbilt University + + align:start position:0% +position at Vanderbilt University + + + align:start position:0% +position at Vanderbilt University +so for which we wish him luck but I'm + + align:start position:0% +so for which we wish him luck but I'm + + + align:start position:0% +so for which we wish him luck but I'm +glad that we caught him before he leaves + + align:start position:0% +glad that we caught him before he leaves + + + align:start position:0% +glad that we caught him before he leaves +the summer okay + + align:start position:0% +the summer okay + + + align:start position:0% +the summer okay +so quite frankly I wish that I could + + align:start position:0% +so quite frankly I wish that I could + + + align:start position:0% +so quite frankly I wish that I could +tell you a much happier story than the + + align:start position:0% +tell you a much happier story than the + + + align:start position:0% +tell you a much happier story than the +one that you're going to hear from me + + align:start position:0% +one that you're going to hear from me + + + align:start position:0% +one that you're going to hear from me +during the prepared part of my talk and + + align:start position:0% +during the prepared part of my talk and + + + align:start position:0% +during the prepared part of my talk and +maybe Adam will will cheer us up and + + align:start position:0% +maybe Adam will will cheer us up and + + + align:start position:0% +maybe Adam will will cheer us up and +make us more optimistic based on on on + + align:start position:0% +make us more optimistic based on on on + + + align:start position:0% +make us more optimistic based on on on +his experience so you may have noticed + + align:start position:0% +his experience so you may have noticed + + + align:start position:0% +his experience so you may have noticed +that AI is hot so hims for example is + + align:start position:0% +that AI is hot so hims for example is + + + align:start position:0% +that AI is hot so hims for example is +the health information management system + + align:start position:0% +the health information management system + + + align:start position:0% +the health information management system +Society it's a big they hold annual + + align:start position:0% +Society it's a big they hold annual + + + align:start position:0% +Society it's a big they hold annual +meetings and and consist of a lot of + + align:start position:0% +meetings and and consist of a lot of + + + align:start position:0% +meetings and and consist of a lot of +vendors and a lot of academics and it's + + align:start position:0% +vendors and a lot of academics and it's + + + align:start position:0% +vendors and a lot of academics and it's +one of these huge tradeshow kinds of + + align:start position:0% +one of these huge tradeshow kinds of + + + align:start position:0% +one of these huge tradeshow kinds of +things with balloons hanging over booths + + align:start position:0% +things with balloons hanging over booths + + + align:start position:0% +things with balloons hanging over booths +and big big open spaces and so for + + align:start position:0% +and big big open spaces and so for + + + align:start position:0% +and big big open spaces and so for +example they are now talking about AI + + align:start position:0% +example they are now talking about AI + + + align:start position:0% +example they are now talking about AI +powered healthcare on the other hand + + align:start position:0% +powered healthcare on the other hand + + + align:start position:0% +powered healthcare on the other hand +it's important to remember this graph so + + align:start position:0% +it's important to remember this graph so + + + align:start position:0% +it's important to remember this graph so +this is the sort of technology adoption + + align:start position:0% +this is the sort of technology adoption + + + align:start position:0% +this is the sort of technology adoption +graph and it's called the height cycle + + align:start position:0% +graph and it's called the height cycle + + + align:start position:0% +graph and it's called the height cycle +and what you see here is that our MD + + align:start position:0% +and what you see here is that our MD + + + align:start position:0% +and what you see here is that our MD +produces some wonderful interesting idea + + align:start position:0% +produces some wonderful interesting idea + + + align:start position:0% +produces some wonderful interesting idea +and then all of a sudden people get + + align:start position:0% +and then all of a sudden people get + + + align:start position:0% +and then all of a sudden people get +excited about it so who are the people + + align:start position:0% +excited about it so who are the people + + + align:start position:0% +excited about it so who are the people +that get most excited about it it's the + + align:start position:0% +that get most excited about it it's the + + + align:start position:0% +that get most excited about it it's the +people who think they're going to make a + + align:start position:0% +people who think they're going to make a + + + align:start position:0% +people who think they're going to make a +fortune from it and these are the so + + align:start position:0% +fortune from it and these are the so + + + align:start position:0% +fortune from it and these are the so +called vulture capitalists + + align:start position:0% +called vulture capitalists + + + align:start position:0% +called vulture capitalists +you're capitalists and so the venture + + align:start position:0% +you're capitalists and so the venture + + + align:start position:0% +you're capitalists and so the venture +capitalists come in and they encourage + + align:start position:0% +capitalists come in and they encourage + + + align:start position:0% +capitalists come in and they encourage +people like us to go out and found + + align:start position:0% +people like us to go out and found + + + align:start position:0% +people like us to go out and found +companies or if if not us then our + + align:start position:0% +companies or if if not us then our + + + align:start position:0% +companies or if if not us then our +students to go found companies and + + align:start position:0% +students to go found companies and + + + align:start position:0% +students to go found companies and +figure out how to turn this nascent idea + + align:start position:0% +figure out how to turn this nascent idea + + + align:start position:0% +figure out how to turn this nascent idea +into some important money-making + + align:start position:0% +into some important money-making + + + align:start position:0% +into some important money-making +enterprise now the secret of venture + + align:start position:0% +enterprise now the secret of venture + + + align:start position:0% +enterprise now the secret of venture +capital is that they know that about 90% + + align:start position:0% +capital is that they know that about 90% + + + align:start position:0% +capital is that they know that about 90% +of the companies that they fund are + + align:start position:0% +of the companies that they fund are + + + align:start position:0% +of the companies that they fund are +going to tank they're going to do very + + align:start position:0% +going to tank they're going to do very + + + align:start position:0% +going to tank they're going to do very +badly and so as a result what they hope + + align:start position:0% +badly and so as a result what they hope + + + align:start position:0% +badly and so as a result what they hope +for and what they expect and what the + + align:start position:0% +for and what they expect and what the + + + align:start position:0% +for and what they expect and what the +good ones actually get is that that one + + align:start position:0% +good ones actually get is that that one + + + align:start position:0% +good ones actually get is that that one +in ten that becomes successful makes so + + align:start position:0% +in ten that becomes successful makes so + + + align:start position:0% +in ten that becomes successful makes so +much money that it makes up for all of + + align:start position:0% +much money that it makes up for all of + + + align:start position:0% +much money that it makes up for all of +the investment that they poured into the + + align:start position:0% +the investment that they poured into the + + + align:start position:0% +the investment that they poured into the +nine out of ten that do badly so I + + align:start position:0% +nine out of ten that do badly so I + + + align:start position:0% +nine out of ten that do badly so I +actually remember in the 1990s I was + + align:start position:0% +actually remember in the 1990s I was + + + align:start position:0% +actually remember in the 1990s I was +helping a group pitch a company to + + align:start position:0% +helping a group pitch a company to + + + align:start position:0% +helping a group pitch a company to +kleiner perkins which is the big event + + align:start position:0% +kleiner perkins which is the big event + + + align:start position:0% +kleiner perkins which is the big event +one of the big venture capital funds in + + align:start position:0% +one of the big venture capital funds in + + + align:start position:0% +one of the big venture capital funds in +Silicon Valley and we walked into their + + align:start position:0% +Silicon Valley and we walked into their + + + align:start position:0% +Silicon Valley and we walked into their +boardroom and they had a copy of the San + + align:start position:0% +boardroom and they had a copy of the San + + + align:start position:0% +boardroom and they had a copy of the San +Jose Mercury News which is the local + + align:start position:0% +Jose Mercury News which is the local + + + align:start position:0% +Jose Mercury News which is the local +newspaper for Silicon Valley on their + + align:start position:0% +newspaper for Silicon Valley on their + + + align:start position:0% +newspaper for Silicon Valley on their +table and they were just beaming because + + align:start position:0% +table and they were just beaming because + + + align:start position:0% +table and they were just beaming because +there was an article that said that in + + align:start position:0% +there was an article that said that in + + + align:start position:0% +there was an article that said that in +the past year the two best and the two + + align:start position:0% +the past year the two best and the two + + + align:start position:0% +the past year the two best and the two +worst investments in Silicon Valley had + + align:start position:0% +worst investments in Silicon Valley had + + + align:start position:0% +worst investments in Silicon Valley had +been by their company right but that's + + align:start position:0% +been by their company right but that's + + + align:start position:0% +been by their company right but that's +pretty good right if you're if you get + + align:start position:0% +pretty good right if you're if you get + + + align:start position:0% +pretty good right if you're if you get +two winners and two really bad losers + + align:start position:0% +two winners and two really bad losers + + + align:start position:0% +two winners and two really bad losers +you're making tons and tons of money so + + align:start position:0% +you're making tons and tons of money so + + + align:start position:0% +you're making tons and tons of money so +they were in a good mood and they funded + + align:start position:0% +they were in a good mood and they funded + + + align:start position:0% +they were in a good mood and they funded +us we didn't make them any money so what + + align:start position:0% +us we didn't make them any money so what + + + align:start position:0% +us we didn't make them any money so what +you see on this curve is that there's a + + align:start position:0% +you see on this curve is that there's a + + + align:start position:0% +you see on this curve is that there's a +kind of a set of rising expectations + + align:start position:0% +kind of a set of rising expectations + + + align:start position:0% +kind of a set of rising expectations +that comes from the development of these + + align:start position:0% +that comes from the development of these + + + align:start position:0% +that comes from the development of these +technologies and you have some early + + align:start position:0% +technologies and you have some early + + + align:start position:0% +technologies and you have some early +adopters + + align:start position:0% +adopters + + + align:start position:0% +adopters +and you have the newspapers writing + + align:start position:0% +and you have the newspapers writing + + + align:start position:0% +and you have the newspapers writing +about how this is the revolution and + + align:start position:0% +about how this is the revolution and + + + align:start position:0% +about how this is the revolution and +everything will be different from here + + align:start position:0% +everything will be different from here + + + align:start position:0% +everything will be different from here +on out and then you have some additional + + align:start position:0% +on out and then you have some additional + + + align:start position:0% +on out and then you have some additional +activity beyond early adopters and then + + align:start position:0% +activity beyond early adopters and then + + + align:start position:0% +activity beyond early adopters and then +people start looking at this and going + + align:start position:0% +people start looking at this and going + + + align:start position:0% +people start looking at this and going +well it really isn't as good as as it's + + align:start position:0% +well it really isn't as good as as it's + + + align:start position:0% +well it really isn't as good as as it's +cracked up to be and then you have the + + align:start position:0% +cracked up to be and then you have the + + + align:start position:0% +cracked up to be and then you have the +steep decline where there's some + + align:start position:0% +steep decline where there's some + + + align:start position:0% +steep decline where there's some +consolidation and some failures and + + align:start position:0% +consolidation and some failures and + + + align:start position:0% +consolidation and some failures and +people have to go back to venture + + align:start position:0% +people have to go back to venture + + + align:start position:0% +people have to go back to venture +capital to try to get more money in + + align:start position:0% +capital to try to get more money in + + + align:start position:0% +capital to try to get more money in +order to keep their companies going and + + align:start position:0% +order to keep their companies going and + + + align:start position:0% +order to keep their companies going and +then there's a kind of trough where + + align:start position:0% +then there's a kind of trough where + + + align:start position:0% +then there's a kind of trough where +people go oh well this was another of + + align:start position:0% +people go oh well this was another of + + + align:start position:0% +people go oh well this was another of +these failed kind of technological + + align:start position:0% +these failed kind of technological + + + align:start position:0% +these failed kind of technological +innovations and then gradually you start + + align:start position:0% +innovations and then gradually you start + + + align:start position:0% +innovations and then gradually you start +reaching what if this author calls the + + align:start position:0% +reaching what if this author calls the + + + align:start position:0% +reaching what if this author calls the +slope of enlightenment where people + + align:start position:0% +slope of enlightenment where people + + + align:start position:0% +slope of enlightenment where people +realize that okay it's not really as bad + + align:start position:0% +realize that okay it's not really as bad + + + align:start position:0% +realize that okay it's not really as bad +as we thought it was when it didn't meet + + align:start position:0% +as we thought it was when it didn't meet + + + align:start position:0% +as we thought it was when it didn't meet +our lofty expectations and then + + align:start position:0% +our lofty expectations and then + + + align:start position:0% +our lofty expectations and then +gradually if it's successful then you + + align:start position:0% +gradually if it's successful then you + + + align:start position:0% +gradually if it's successful then you +get multiple generations of the product + + align:start position:0% +get multiple generations of the product + + + align:start position:0% +get multiple generations of the product +and it does achieve adoption the + + align:start position:0% +and it does achieve adoption the + + + align:start position:0% +and it does achieve adoption the +adoption almost never reaches the peak + + align:start position:0% +adoption almost never reaches the peak + + + align:start position:0% +adoption almost never reaches the peak +that it was expected to reach at the + + align:start position:0% +that it was expected to reach at the + + + align:start position:0% +that it was expected to reach at the +time of the the top of the hike cycle + + align:start position:0% +time of the the top of the hike cycle + + + align:start position:0% +time of the the top of the hike cycle +but it becomes useful becomes profitable + + align:start position:0% +but it becomes useful becomes profitable + + + align:start position:0% +but it becomes useful becomes profitable +it becomes productive now I've been + + align:start position:0% +it becomes productive now I've been + + + align:start position:0% +it becomes productive now I've been +around long enough to see a number of + + align:start position:0% +around long enough to see a number of + + + align:start position:0% +around long enough to see a number of +these cycles go by so in the 1980s for + + align:start position:0% +these cycles go by so in the 1980s for + + + align:start position:0% +these cycles go by so in the 1980s for +example at a time that was now jokingly + + align:start position:0% +example at a time that was now jokingly + + + align:start position:0% +example at a time that was now jokingly +referred to as a isomer where people + + align:start position:0% +referred to as a isomer where people + + + align:start position:0% +referred to as a isomer where people +were building expert systems and these + + align:start position:0% +were building expert systems and these + + + align:start position:0% +were building expert systems and these +expert systems were going to just + + align:start position:0% +expert systems were going to just + + + align:start position:0% +expert systems were going to just +revolutionize everything I remember + + align:start position:0% +revolutionize everything I remember + + + align:start position:0% +revolutionize everything I remember +going to a conference where the Campbell + + align:start position:0% +going to a conference where the Campbell + + + align:start position:0% +going to a conference where the Campbell +Soup Company had built an expert system + + align:start position:0% +Soup Company had built an expert system + + + align:start position:0% +Soup Company had built an expert system +that that was based on the expertise of + + align:start position:0% +that that was based on the expertise of + + + align:start position:0% +that that was based on the expertise of +some old-timers who were retiring and + + align:start position:0% +some old-timers who were retiring and + + + align:start position:0% +some old-timers who were retiring and +what this expert system did is it told + + align:start position:0% +what this expert system did is it told + + + align:start position:0% +what this expert system did is it told +you how to clean the vats of soup you + + align:start position:0% +you how to clean the vats of soup you + + + align:start position:0% +you how to clean the vats of soup you +know these giant million gallon things + + align:start position:0% +know these giant million gallon things + + + align:start position:0% +know these giant million gallon things +where they make sue + + align:start position:0% +where they make sue + + + align:start position:0% +where they make sue +when you're switching from making one + + align:start position:0% +when you're switching from making one + + + align:start position:0% +when you're switching from making one +kind of soup to another so you know if + + align:start position:0% +kind of soup to another so you know if + + + align:start position:0% +kind of soup to another so you know if +you're making beef consommé and you + + align:start position:0% +you're making beef consommé and you + + + align:start position:0% +you're making beef consommé and you +switch to making beef barley soup you + + align:start position:0% +switch to making beef barley soup you + + + align:start position:0% +switch to making beef barley soup you +don't need to clean the VAT at all + + align:start position:0% +don't need to clean the VAT at all + + + align:start position:0% +don't need to clean the VAT at all +whereas if you're switching from you + + align:start position:0% +whereas if you're switching from you + + + align:start position:0% +whereas if you're switching from you +know something like clam chowder to a + + align:start position:0% +know something like clam chowder to a + + + align:start position:0% +know something like clam chowder to a +consomme then you need to clean it + + align:start position:0% +consomme then you need to clean it + + + align:start position:0% +consomme then you need to clean it +really well and so this was exactly the + + align:start position:0% +really well and so this was exactly the + + + align:start position:0% +really well and so this was exactly the +kind of thing that they were doing and + + align:start position:0% +kind of thing that they were doing and + + + align:start position:0% +kind of thing that they were doing and +there were literally literally thousands + + align:start position:0% +there were literally literally thousands + + + align:start position:0% +there were literally literally thousands +of these applications being built and at + + align:start position:0% +of these applications being built and at + + + align:start position:0% +of these applications being built and at +the top of the hype cycle all kinds of + + align:start position:0% +the top of the hype cycle all kinds of + + + align:start position:0% +the top of the hype cycle all kinds of +companies like Campbell Soup and the + + align:start position:0% +companies like Campbell Soup and the + + + align:start position:0% +companies like Campbell Soup and the +airlines and everybody was investing + + align:start position:0% +airlines and everybody was investing + + + align:start position:0% +airlines and everybody was investing +huge amounts of money into this and then + + align:start position:0% +huge amounts of money into this and then + + + align:start position:0% +huge amounts of money into this and then +there was a kind of failure of + + align:start position:0% +there was a kind of failure of + + + align:start position:0% +there was a kind of failure of +expectations these didn't turn out to be + + align:start position:0% +expectations these didn't turn out to be + + + align:start position:0% +expectations these didn't turn out to be +as good as people thought they were + + align:start position:0% +as good as people thought they were + + + align:start position:0% +as good as people thought they were +going to be or as valuable as people + + align:start position:0% +going to be or as valuable as people + + + align:start position:0% +going to be or as valuable as people +thought they were going to be and then + + align:start position:0% +thought they were going to be and then + + + align:start position:0% +thought they were going to be and then +all of a sudden came AI winter so AI + + align:start position:0% +all of a sudden came AI winter so AI + + + align:start position:0% +all of a sudden came AI winter so AI +winter followed AI summer there was no + + align:start position:0% +winter followed AI summer there was no + + + align:start position:0% +winter followed AI summer there was no +AI fall except in a different sense of + + align:start position:0% +AI fall except in a different sense of + + + align:start position:0% +AI fall except in a different sense of +the word fall and and all of a sudden + + align:start position:0% +the word fall and and all of a sudden + + + align:start position:0% +the word fall and and all of a sudden +funding dried up and and the whole thing + + align:start position:0% +funding dried up and and the whole thing + + + align:start position:0% +funding dried up and and the whole thing +was declared a failure but in fact today + + align:start position:0% +was declared a failure but in fact today + + + align:start position:0% +was declared a failure but in fact today +if you go out there and you look at you + + align:start position:0% +if you go out there and you look at you + + + align:start position:0% +if you go out there and you look at you +know Microsoft Excel has an expert + + align:start position:0% +know Microsoft Excel has an expert + + + align:start position:0% +know Microsoft Excel has an expert +system based help system bundled inside + + align:start position:0% +system based help system bundled inside + + + align:start position:0% +system based help system bundled inside +it and there are tons of such + + align:start position:0% +it and there are tons of such + + + align:start position:0% +it and there are tons of such +applications it's just that now they're + + align:start position:0% +applications it's just that now they're + + + align:start position:0% +applications it's just that now they're +no longer considered cutting-edge + + align:start position:0% +no longer considered cutting-edge + + + align:start position:0% +no longer considered cutting-edge +applications of artificial intelligence + + align:start position:0% +applications of artificial intelligence + + + align:start position:0% +applications of artificial intelligence +they're simply considered you know + + align:start position:0% +they're simply considered you know + + + align:start position:0% +they're simply considered you know +routine practice so they they've become + + align:start position:0% +routine practice so they they've become + + + align:start position:0% +routine practice so they they've become +incorporated without the hype into all + + align:start position:0% +incorporated without the hype into all + + + align:start position:0% +incorporated without the hype into all +kinds of existing products and and + + align:start position:0% +kinds of existing products and and + + + align:start position:0% +kinds of existing products and and +they're serving a very useful role but + + align:start position:0% +they're serving a very useful role but + + + align:start position:0% +they're serving a very useful role but +they didn't make those venture capital + + align:start position:0% +they didn't make those venture capital + + + align:start position:0% +they didn't make those venture capital +firms the tons of money that they had + + align:start position:0% +firms the tons of money that they had + + + align:start position:0% +firms the tons of money that they had +hoped to make there was a similar boom + + align:start position:0% +hoped to make there was a similar boom + + + align:start position:0% +hoped to make there was a similar boom +and bust cycle in the 2000s around the + + align:start position:0% +and bust cycle in the 2000s around the + + + align:start position:0% +and bust cycle in the 2000s around the +creation of the world wide web and + + align:start position:0% +creation of the world wide web and + + + align:start position:0% +creation of the world wide web and +e-commerce + + align:start position:0% +e-commerce + + + align:start position:0% +e-commerce +okay so ecommerce again there was this + + align:start position:0% +okay so ecommerce again there was this + + + align:start position:0% +okay so ecommerce again there was this +unbelievably inflated set of + + align:start position:0% +unbelievably inflated set of + + + align:start position:0% +unbelievably inflated set of +expectations and then around the year + + align:start position:0% +expectations and then around the year + + + align:start position:0% +expectations and then around the year +2000 there was a + + align:start position:0% +2000 there was a + + + align:start position:0% +2000 there was a +big crash where all of a sudden you know + + align:start position:0% +big crash where all of a sudden you know + + + align:start position:0% +big crash where all of a sudden you know +people realized that the value in these + + align:start position:0% +people realized that the value in these + + + align:start position:0% +people realized that the value in these +applications was not as high as what + + align:start position:0% +applications was not as high as what + + + align:start position:0% +applications was not as high as what +they expected it to be nevertheless you + + align:start position:0% +they expected it to be nevertheless you + + + align:start position:0% +they expected it to be nevertheless you +know Amazon is doing just fine and there + + align:start position:0% +know Amazon is doing just fine and there + + + align:start position:0% +know Amazon is doing just fine and there +are plenty of online e-commerce sites + + align:start position:0% +are plenty of online e-commerce sites + + + align:start position:0% +are plenty of online e-commerce sites +that are in perfectly good operating + + align:start position:0% +that are in perfectly good operating + + + align:start position:0% +that are in perfectly good operating +order today and but it's no longer the + + align:start position:0% +order today and but it's no longer the + + + align:start position:0% +order today and but it's no longer the +same hype about this technology it's + + align:start position:0% +same hype about this technology it's + + + align:start position:0% +same hype about this technology it's +just become an accepted part of the way + + align:start position:0% +just become an accepted part of the way + + + align:start position:0% +just become an accepted part of the way +that you do business and almost + + align:start position:0% +that you do business and almost + + + align:start position:0% +that you do business and almost +everything yeah they were either rule + + align:start position:0% +everything yeah they were either rule + + + align:start position:0% +everything yeah they were either rule +based or pattern-matching systems there + + align:start position:0% +based or pattern-matching systems there + + + align:start position:0% +based or pattern-matching systems there +were two basic kinds I think a week from + + align:start position:0% +were two basic kinds I think a week from + + + align:start position:0% +were two basic kinds I think a week from +today I'm going to talk about some of + + align:start position:0% +today I'm going to talk about some of + + + align:start position:0% +today I'm going to talk about some of +that and how it relates to modern + + align:start position:0% +that and how it relates to modern + + + align:start position:0% +that and how it relates to modern +machine learning so we'll see some + + align:start position:0% +machine learning so we'll see some + + + align:start position:0% +machine learning so we'll see some +examples okay well a cautionary tale is + + align:start position:0% +examples okay well a cautionary tale is + + + align:start position:0% +examples okay well a cautionary tale is +is IBM's Watson health so I assume most + + align:start position:0% +is IBM's Watson health so I assume most + + + align:start position:0% +is IBM's Watson health so I assume most +of you remember when Watson hit the big + + align:start position:0% +of you remember when Watson hit the big + + + align:start position:0% +of you remember when Watson hit the big +time by beating the Jeopardy champions + + align:start position:0% +time by beating the Jeopardy champions + + + align:start position:0% +time by beating the Jeopardy champions +this was back in the early 2010's or + + align:start position:0% +this was back in the early 2010's or + + + align:start position:0% +this was back in the early 2010's or +something I don't remember exactly which + + align:start position:0% +something I don't remember exactly which + + + align:start position:0% +something I don't remember exactly which +year and they had in fact built a really + + align:start position:0% +year and they had in fact built a really + + + align:start position:0% +year and they had in fact built a really +impressive set of technologies that went + + align:start position:0% +impressive set of technologies that went + + + align:start position:0% +impressive set of technologies that went +out and read all kinds of online sources + + align:start position:0% +out and read all kinds of online sources + + + align:start position:0% +out and read all kinds of online sources +and distilled them into a kind of + + align:start position:0% +and distilled them into a kind of + + + align:start position:0% +and distilled them into a kind of +representation that they could very + + align:start position:0% +representation that they could very + + + align:start position:0% +representation that they could very +quickly look up things when they were + + align:start position:0% +quickly look up things when they were + + + align:start position:0% +quickly look up things when they were +challenged with the Jeopardy question + + align:start position:0% +challenged with the Jeopardy question + + + align:start position:0% +challenged with the Jeopardy question +and then it had a sophisticated set of + + align:start position:0% +and then it had a sophisticated set of + + + align:start position:0% +and then it had a sophisticated set of +algorithms that would try to find the + + align:start position:0% +algorithms that would try to find the + + + align:start position:0% +algorithms that would try to find the +best answer for some question and they + + align:start position:0% +best answer for some question and they + + + align:start position:0% +best answer for some question and they +even had all kinds of bizarre + + align:start position:0% +even had all kinds of bizarre + + + align:start position:0% +even had all kinds of bizarre +special-purpose things I remember there + + align:start position:0% +special-purpose things I remember there + + + align:start position:0% +special-purpose things I remember there +was a probabilistic model that figured + + align:start position:0% +was a probabilistic model that figured + + + align:start position:0% +was a probabilistic model that figured +out where the Daily Double + + align:start position:0% +out where the Daily Double + + + align:start position:0% +out where the Daily Double +squares were most likely to be on the + + align:start position:0% +squares were most likely to be on the + + + align:start position:0% +squares were most likely to be on the +Jeopardy board and then they did a + + align:start position:0% +Jeopardy board and then they did a + + + align:start position:0% +Jeopardy board and then they did a +utility theoretic calculation to figure + + align:start position:0% +utility theoretic calculation to figure + + + align:start position:0% +utility theoretic calculation to figure +out if they did hit the Daily Double + + align:start position:0% +out if they did hit the Daily Double + + + align:start position:0% +out if they did hit the Daily Double +what was the optimum amount of money to + + align:start position:0% +what was the optimum amount of money to + + + align:start position:0% +what was the optimum amount of money to +bet based on on the machines performance + + align:start position:0% +bet based on on the machines performance + + + align:start position:0% +bet based on on the machines performance +in order to optimize + + align:start position:0% +in order to optimize + + + align:start position:0% +in order to optimize +they decided that humans typically don't + + align:start position:0% +they decided that humans typically don't + + + align:start position:0% +they decided that humans typically don't +bet enough when they have a chance in on + + align:start position:0% +bet enough when they have a chance in on + + + align:start position:0% +bet enough when they have a chance in on +The Daily Double + + align:start position:0% +The Daily Double + + + align:start position:0% +The Daily Double +so there was a lot of very special + + align:start position:0% +so there was a lot of very special + + + align:start position:0% +so there was a lot of very special +purpose stuff done for this so this was + + align:start position:0% +purpose stuff done for this so this was + + + align:start position:0% +purpose stuff done for this so this was +a huge publicity bonanza and IBM decided + + align:start position:0% +a huge publicity bonanza and IBM decided + + + align:start position:0% +a huge publicity bonanza and IBM decided +that next they were going to tackle + + align:start position:0% +that next they were going to tackle + + + align:start position:0% +that next they were going to tackle +medicine and so they were going to take + + align:start position:0% +medicine and so they were going to take + + + align:start position:0% +medicine and so they were going to take +this technology and apply it to medicine + + align:start position:0% +this technology and apply it to medicine + + + align:start position:0% +this technology and apply it to medicine +they were going to read all of the + + align:start position:0% +they were going to read all of the + + + align:start position:0% +they were going to read all of the +medical journals and all of the medical + + align:start position:0% +medical journals and all of the medical + + + align:start position:0% +medical journals and all of the medical +electronic medical records that they + + align:start position:0% +electronic medical records that they + + + align:start position:0% +electronic medical records that they +could get their hands on and somehow + + align:start position:0% +could get their hands on and somehow + + + align:start position:0% +could get their hands on and somehow +this technology would again distill the + + align:start position:0% +this technology would again distill the + + + align:start position:0% +this technology would again distill the +right information so that they could + + align:start position:0% +right information so that they could + + + align:start position:0% +right information so that they could +answer questions like a Jeopardy + + align:start position:0% +answer questions like a Jeopardy + + + align:start position:0% +answer questions like a Jeopardy +question except not stated in its funny + + align:start position:0% +question except not stated in its funny + + + align:start position:0% +question except not stated in its funny +backward way where you might say okay + + align:start position:0% +backward way where you might say okay + + + align:start position:0% +backward way where you might say okay +for this patient what is the optimum + + align:start position:0% +for this patient what is the optimum + + + align:start position:0% +for this patient what is the optimum +therapy and it would go out and use the + + align:start position:0% +therapy and it would go out and use the + + + align:start position:0% +therapy and it would go out and use the +same technology to figure that out now + + align:start position:0% +same technology to figure that out now + + + align:start position:0% +same technology to figure that out now +that was a perfectly reasonable thing to + + align:start position:0% +that was a perfectly reasonable thing to + + + align:start position:0% +that was a perfectly reasonable thing to +try the the problem they ran into was + + align:start position:0% +try the the problem they ran into was + + + align:start position:0% +try the the problem they ran into was +this hype cycle that the people who made + + align:start position:0% +this hype cycle that the people who made + + + align:start position:0% +this hype cycle that the people who made +this publicly known were their marketing + + align:start position:0% +this publicly known were their marketing + + + align:start position:0% +this publicly known were their marketing +people and not their technical people + + align:start position:0% +people and not their technical people + + + align:start position:0% +people and not their technical people +and the marketing people over-promised + + align:start position:0% +and the marketing people over-promised + + + align:start position:0% +and the marketing people over-promised +like crazy okay they said surely this is + + align:start position:0% +like crazy okay they said surely this is + + + align:start position:0% +like crazy okay they said surely this is +just gonna solve all these problems and + + align:start position:0% +just gonna solve all these problems and + + + align:start position:0% +just gonna solve all these problems and +we won't need any more research in this + + align:start position:0% +we won't need any more research in this + + + align:start position:0% +we won't need any more research in this +area because man we got it III mean I'm + + align:start position:0% +area because man we got it III mean I'm + + + align:start position:0% +area because man we got it III mean I'm +overstating it even from the marketing + + align:start position:0% +overstating it even from the marketing + + + align:start position:0% +overstating it even from the marketing +point of view and so Watson for oncology + + align:start position:0% +point of view and so Watson for oncology + + + align:start position:0% +point of view and so Watson for oncology +used this cloud-based supercomputer to + + align:start position:0% +used this cloud-based supercomputer to + + + align:start position:0% +used this cloud-based supercomputer to +digest massive amounts of data and and + + align:start position:0% +digest massive amounts of data and and + + + align:start position:0% +digest massive amounts of data and and +that data included all kinds of + + align:start position:0% +that data included all kinds of + + + align:start position:0% +that data included all kinds of +different different things so I'm gonna + + align:start position:0% +different different things so I'm gonna + + + align:start position:0% +different different things so I'm gonna +go into a little bit of detail about + + align:start position:0% +go into a little bit of detail about + + + align:start position:0% +go into a little bit of detail about +what some of their problems were this is + + align:start position:0% +what some of their problems were this is + + + align:start position:0% +what some of their problems were this is +from an article in in this this journal + + align:start position:0% +from an article in in this this journal + + + align:start position:0% +from an article in in this this journal +stat news which did an investigative + + align:start position:0% +stat news which did an investigative + + + align:start position:0% +stat news which did an investigative +piece on on what happened with Watson + + align:start position:0% +piece on on what happened with Watson + + + align:start position:0% +piece on on what happened with Watson +and so you know they say what I just + + align:start position:0% +and so you know they say what I just + + + align:start position:0% +and so you know they say what I just +said breathlessly promoting its + + align:start position:0% +said breathlessly promoting its + + + align:start position:0% +said breathlessly promoting its +signature brands IBM sought to capture + + align:start position:0% +signature brands IBM sought to capture + + + align:start position:0% +signature brands IBM sought to capture +the world's imagination and quickly + + align:start position:0% +the world's imagination and quickly + + + align:start position:0% +the world's imagination and quickly +zeroed in on a high-profile target which + + align:start position:0% +zeroed in on a high-profile target which + + + align:start position:0% +zeroed in on a high-profile target which +cancer so this was gonna solve the + + align:start position:0% +cancer so this was gonna solve the + + + align:start position:0% +cancer so this was gonna solve the +problem of some patient shows up is + + align:start position:0% +problem of some patient shows up is + + + align:start position:0% +problem of some patient shows up is +diagnosed with cancer and you want to + + align:start position:0% +diagnosed with cancer and you want to + + + align:start position:0% +diagnosed with cancer and you want to +know how to treat this person so this + + align:start position:0% +know how to treat this person so this + + + align:start position:0% +know how to treat this person so this +would use all of the literature and all + + align:start position:0% +would use all of the literature and all + + + align:start position:0% +would use all of the literature and all +of everything that it had gathered from + + align:start position:0% +of everything that it had gathered from + + + align:start position:0% +of everything that it had gathered from +previous treatments of previous patients + + align:start position:0% +previous treatments of previous patients + + + align:start position:0% +previous treatments of previous patients +and it would give you the optimal + + align:start position:0% +and it would give you the optimal + + + align:start position:0% +and it would give you the optimal +solution now it has not been a success + + align:start position:0% +solution now it has not been a success + + + align:start position:0% +solution now it has not been a success +there were a few dozen hospitals that + + align:start position:0% +there were a few dozen hospitals that + + + align:start position:0% +there were a few dozen hospitals that +have adopted the system very few of them + + align:start position:0% +have adopted the system very few of them + + + align:start position:0% +have adopted the system very few of them +in the United States more of them abroad + + align:start position:0% +in the United States more of them abroad + + + align:start position:0% +in the United States more of them abroad +and the foreigners complained that its + + align:start position:0% +and the foreigners complained that its + + + align:start position:0% +and the foreigners complained that its +advice is biased toward American + + align:start position:0% +advice is biased toward American + + + align:start position:0% +advice is biased toward American +patients and American approaches to me + + align:start position:0% +patients and American approaches to me + + + align:start position:0% +patients and American approaches to me +the biggest problem is that they haven't + + align:start position:0% +the biggest problem is that they haven't + + + align:start position:0% +the biggest problem is that they haven't +actually published anything that + + align:start position:0% +actually published anything that + + + align:start position:0% +actually published anything that +validates in a scientific sense that + + align:start position:0% +validates in a scientific sense that + + + align:start position:0% +validates in a scientific sense that +this is a good idea that it's getting + + align:start position:0% +this is a good idea that it's getting + + + align:start position:0% +this is a good idea that it's getting +the right answers and my guess is the + + align:start position:0% +the right answers and my guess is the + + + align:start position:0% +the right answers and my guess is the +reason for this is because it's not + + align:start position:0% +reason for this is because it's not + + + align:start position:0% +reason for this is because it's not +getting the right answers a lot of the + + align:start position:0% +getting the right answers a lot of the + + + align:start position:0% +getting the right answers a lot of the +time but that doesn't prevent marketing + + align:start position:0% +time but that doesn't prevent marketing + + + align:start position:0% +time but that doesn't prevent marketing +from from selling it the other problem + + align:start position:0% +from from selling it the other problem + + + align:start position:0% +from from selling it the other problem +is that they made a deal with Memorial + + align:start position:0% +is that they made a deal with Memorial + + + align:start position:0% +is that they made a deal with Memorial +sloan-kettering which is one of the + + align:start position:0% +sloan-kettering which is one of the + + + align:start position:0% +sloan-kettering which is one of the +leading cancer hospitals in the country + + align:start position:0% +leading cancer hospitals in the country + + + align:start position:0% +leading cancer hospitals in the country +to say we're gonna work with you guys + + align:start position:0% +to say we're gonna work with you guys + + + align:start position:0% +to say we're gonna work with you guys +and and your oncologists in order to + + align:start position:0% +and and your oncologists in order to + + + align:start position:0% +and and your oncologists in order to +figure out what really is the right + + align:start position:0% +figure out what really is the right + + + align:start position:0% +figure out what really is the right +answer and so I think they tried to do + + align:start position:0% +answer and so I think they tried to do + + + align:start position:0% +answer and so I think they tried to do +what their marketing says that they're + + align:start position:0% +what their marketing says that they're + + + align:start position:0% +what their marketing says that they're +doing which is to really derive the + + align:start position:0% +doing which is to really derive the + + + align:start position:0% +doing which is to really derive the +right answer from reading all of the + + align:start position:0% +right answer from reading all of the + + + align:start position:0% +right answer from reading all of the +literature and looking at past cases but + + align:start position:0% +literature and looking at past cases but + + + align:start position:0% +literature and looking at past cases but +I don't think that worked well enough + + align:start position:0% +I don't think that worked well enough + + + align:start position:0% +I don't think that worked well enough +and so what they wound up doing is + + align:start position:0% +and so what they wound up doing is + + + align:start position:0% +and so what they wound up doing is +turning to real oncologists saying what + + align:start position:0% +turning to real oncologists saying what + + + align:start position:0% +turning to real oncologists saying what +would you do under these circumstances + + align:start position:0% +would you do under these circumstances + + + align:start position:0% +would you do under these circumstances +and so what they wound up building is + + align:start position:0% +and so what they wound up building is + + + align:start position:0% +and so what they wound up building is +something like a rule based system that + + align:start position:0% +something like a rule based system that + + + align:start position:0% +something like a rule based system that +says if you see the following symptoms + + align:start position:0% +says if you see the following symptoms + + + align:start position:0% +says if you see the following symptoms +and you have the following genetic + + align:start position:0% +and you have the following genetic + + + align:start position:0% +and you have the following genetic +defects then this is the right treatment + + align:start position:0% +defects then this is the right treatment + + + align:start position:0% +defects then this is the right treatment +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and so the promise that this was going + + align:start position:0% +and so the promise that this was going + + + align:start position:0% +and so the promise that this was going +to be a machine learning system that + + align:start position:0% +to be a machine learning system that + + + align:start position:0% +to be a machine learning system that +revolutionized cancer care by finding + + align:start position:0% +revolutionized cancer care by finding + + + align:start position:0% +revolutionized cancer care by finding +the optimal treatment really is not what + + align:start position:0% +the optimal treatment really is not what + + + align:start position:0% +the optimal treatment really is not what +they what they provided and as the + + align:start position:0% +they what they provided and as the + + + align:start position:0% +they what they provided and as the +article says the system doesn't really + + align:start position:0% +article says the system doesn't really + + + align:start position:0% +article says the system doesn't really +create new knowledge + + align:start position:0% +create new knowledge + + + align:start position:0% +create new knowledge +and so it's AI only in the sense of + + align:start position:0% +and so it's AI only in the sense of + + + align:start position:0% +and so it's AI only in the sense of +providing a search engine that when it + + align:start position:0% +providing a search engine that when it + + + align:start position:0% +providing a search engine that when it +makes a recommendation can point you to + + align:start position:0% +makes a recommendation can point you to + + + align:start position:0% +makes a recommendation can point you to +articles that are a reasonable + + align:start position:0% +articles that are a reasonable + + + align:start position:0% +articles that are a reasonable +reflection of what it's recommending + + align:start position:0% +reflection of what it's recommending + + + align:start position:0% +reflection of what it's recommending +well I'm gonna stop going through this + + align:start position:0% +well I'm gonna stop going through this + + + align:start position:0% +well I'm gonna stop going through this +litany but you'll see it in in the + + align:start position:0% +litany but you'll see it in in the + + + align:start position:0% +litany but you'll see it in in the +slides which we'll post they had a big + + align:start position:0% +slides which we'll post they had a big + + + align:start position:0% +slides which we'll post they had a big +contract with MD Anderson which is + + align:start position:0% +contract with MD Anderson which is + + + align:start position:0% +contract with MD Anderson which is +another leading Cancer Center in the + + align:start position:0% +another leading Cancer Center in the + + + align:start position:0% +another leading Cancer Center in the +United States and the Anderson spent + + align:start position:0% +United States and the Anderson spent + + + align:start position:0% +United States and the Anderson spent +about sixty million dollars on this + + align:start position:0% +about sixty million dollars on this + + + align:start position:0% +about sixty million dollars on this +contract implementing it and they pulled + + align:start position:0% +contract implementing it and they pulled + + + align:start position:0% +contract implementing it and they pulled +the plug on it because they decided that + + align:start position:0% +the plug on it because they decided that + + + align:start position:0% +the plug on it because they decided that +it just wasn't wasn't doing the job now + + align:start position:0% +it just wasn't wasn't doing the job now + + + align:start position:0% +it just wasn't wasn't doing the job now +by contrast there was a much more + + align:start position:0% +by contrast there was a much more + + + align:start position:0% +by contrast there was a much more +successful attempt years ago which was + + align:start position:0% +successful attempt years ago which was + + + align:start position:0% +successful attempt years ago which was +less driven by marketing and more driven + + align:start position:0% +less driven by marketing and more driven + + + align:start position:0% +less driven by marketing and more driven +by medical need and the idea here was + + align:start position:0% +by medical need and the idea here was + + + align:start position:0% +by medical need and the idea here was +CPOE stands for computerized physician + + align:start position:0% +CPOE stands for computerized physician + + + align:start position:0% +CPOE stands for computerized physician +order entry + + align:start position:0% +order entry + + + align:start position:0% +order entry +the idea behind CPOE was that if you + + align:start position:0% +the idea behind CPOE was that if you + + + align:start position:0% +the idea behind CPOE was that if you +want to affect the behavior of + + align:start position:0% +want to affect the behavior of + + + align:start position:0% +want to affect the behavior of +clinicians in ordering tests or drugs or + + align:start position:0% +clinicians in ordering tests or drugs or + + + align:start position:0% +clinicians in ordering tests or drugs or +procedures what you want to do is to + + align:start position:0% +procedures what you want to do is to + + + align:start position:0% +procedures what you want to do is to +make sure that they are interacting with + + align:start position:0% +make sure that they are interacting with + + + align:start position:0% +make sure that they are interacting with +the computer so that when they order for + + align:start position:0% +the computer so that when they order for + + + align:start position:0% +the computer so that when they order for +example some insanely expensive drug the + + align:start position:0% +example some insanely expensive drug the + + + align:start position:0% +example some insanely expensive drug the +system can come back and say hey do you + + align:start position:0% +system can come back and say hey do you + + + align:start position:0% +system can come back and say hey do you +realize that there's a drug that costs + + align:start position:0% +realize that there's a drug that costs + + + align:start position:0% +realize that there's a drug that costs +1/100 as much which according to the + + align:start position:0% +1/100 as much which according to the + + + align:start position:0% +1/100 as much which according to the +clinical trials that we have on record + + align:start position:0% +clinical trials that we have on record + + + align:start position:0% +clinical trials that we have on record +is just as effective as the one that + + align:start position:0% +is just as effective as the one that + + + align:start position:0% +is just as effective as the one that +you've ordered and so for example here + + align:start position:0% +you've ordered and so for example here + + + align:start position:0% +you've ordered and so for example here +at the Beth Israel many years ago they + + align:start position:0% +at the Beth Israel many years ago they + + + align:start position:0% +at the Beth Israel many years ago they +implemented a system like that and in + + align:start position:0% +implemented a system like that and in + + + align:start position:0% +implemented a system like that and in +the first year they showed that they + + align:start position:0% +the first year they showed that they + + + align:start position:0% +the first year they showed that they +saved something like 16 million dollars + + align:start position:0% +saved something like 16 million dollars + + + align:start position:0% +saved something like 16 million dollars +in the pharmacy just by ordering cheaper + + align:start position:0% +in the pharmacy just by ordering cheaper + + + align:start position:0% +in the pharmacy just by ordering cheaper +variants of drugs that could have been + + align:start position:0% +variants of drugs that could have been + + + align:start position:0% +variants of drugs that could have been +very expensive and they also found that + + align:start position:0% +very expensive and they also found that + + + align:start position:0% +very expensive and they also found that +the doctors who were doing the ordering + + align:start position:0% +the doctors who were doing the ordering + + + align:start position:0% +the doctors who were doing the ordering +were perfectly satisfied with that + + align:start position:0% +were perfectly satisfied with that + + + align:start position:0% +were perfectly satisfied with that +because they just didn't know how + + align:start position:0% +because they just didn't know how + + + align:start position:0% +because they just didn't know how +expensive these drugs were you know + + align:start position:0% +expensive these drugs were you know + + + align:start position:0% +expensive these drugs were you know +that's not one of the things that they + + align:start position:0% +that's not one of the things that they + + + align:start position:0% +that's not one of the things that they +pay attention + + align:start position:0% +pay attention + + + align:start position:0% +pay attention +- so there are many applications like + + align:start position:0% +- so there are many applications like + + + align:start position:0% +- so there are many applications like +that that are driven by this and again + + align:start position:0% +that that are driven by this and again + + + align:start position:0% +that that are driven by this and again +here are some statistics you can reduce + + align:start position:0% +here are some statistics you can reduce + + + align:start position:0% +here are some statistics you can reduce +error rates by half you can reduce + + align:start position:0% +error rates by half you can reduce + + + align:start position:0% +error rates by half you can reduce +severe medication errors by 88% you can + + align:start position:0% +severe medication errors by 88% you can + + + align:start position:0% +severe medication errors by 88% you can +have a 70% reduction in antibiotic + + align:start position:0% +have a 70% reduction in antibiotic + + + align:start position:0% +have a 70% reduction in antibiotic +related adverse drug events you can + + align:start position:0% +related adverse drug events you can + + + align:start position:0% +related adverse drug events you can +reduce length of stay which is another + + align:start position:0% +reduce length of stay which is another + + + align:start position:0% +reduce length of stay which is another +big goal that people go after and at + + align:start position:0% +big goal that people go after and at + + + align:start position:0% +big goal that people go after and at +least if you're an optimist + + align:start position:0% +least if you're an optimist + + + align:start position:0% +least if you're an optimist +you can believe these extrapolations + + align:start position:0% +you can believe these extrapolations + + + align:start position:0% +you can believe these extrapolations +that say well we could prevent 3 million + + align:start position:0% +that say well we could prevent 3 million + + + align:start position:0% +that say well we could prevent 3 million +adverse drug events at big city + + align:start position:0% +adverse drug events at big city + + + align:start position:0% +adverse drug events at big city +hospitals in the United States if + + align:start position:0% +hospitals in the United States if + + + align:start position:0% +hospitals in the United States if +everybody used systems like this so the + + align:start position:0% +everybody used systems like this so the + + + align:start position:0% +everybody used systems like this so the +benefits are that it prompts with + + align:start position:0% +benefits are that it prompts with + + + align:start position:0% +benefits are that it prompts with +warnings against possible drug + + align:start position:0% +warnings against possible drug + + + align:start position:0% +warnings against possible drug +interactions allergies or overdoses + + align:start position:0% +interactions allergies or overdoses + + + align:start position:0% +interactions allergies or overdoses +it can be kept up to date by some sort + + align:start position:0% +it can be kept up to date by some sort + + + align:start position:0% +it can be kept up to date by some sort +of mechanism where people read the + + align:start position:0% +of mechanism where people read the + + + align:start position:0% +of mechanism where people read the +literature and keep updating the + + align:start position:0% +literature and keep updating the + + + align:start position:0% +literature and keep updating the +databases that this is driven from and + + align:start position:0% +databases that this is driven from and + + + align:start position:0% +databases that this is driven from and +you know it can do sort of mechanical + + align:start position:0% +you know it can do sort of mechanical + + + align:start position:0% +you know it can do sort of mechanical +things like eliminate confusion about + + align:start position:0% +things like eliminate confusion about + + + align:start position:0% +things like eliminate confusion about +drug names that sound similar stuff like + + align:start position:0% +drug names that sound similar stuff like + + + align:start position:0% +drug names that sound similar stuff like +that and so the Leapfrog Group which + + align:start position:0% +that and so the Leapfrog Group which + + + align:start position:0% +that and so the Leapfrog Group which +does a lot of meta analyses and studies + + align:start position:0% +does a lot of meta analyses and studies + + + align:start position:0% +does a lot of meta analyses and studies +of what's effective really is behind + + align:start position:0% +of what's effective really is behind + + + align:start position:0% +of what's effective really is behind +this and and pushing it very strongly + + align:start position:0% +this and and pushing it very strongly + + + align:start position:0% +this and and pushing it very strongly +potential future benefits of course are + + align:start position:0% +potential future benefits of course are + + + align:start position:0% +potential future benefits of course are +that if the kinds of machine learning + + align:start position:0% +that if the kinds of machine learning + + + align:start position:0% +that if the kinds of machine learning +techniques that we talked about become + + align:start position:0% +techniques that we talked about become + + + align:start position:0% +techniques that we talked about become +widely used then these systems can be + + align:start position:0% +widely used then these systems can be + + + align:start position:0% +widely used then these systems can be +updated automatically rather than by + + align:start position:0% +updated automatically rather than by + + + align:start position:0% +updated automatically rather than by +manual review and you can gain the + + align:start position:0% +manual review and you can gain the + + + align:start position:0% +manual review and you can gain the +advantages of immediate feedback as new + + align:start position:0% +advantages of immediate feedback as new + + + align:start position:0% +advantages of immediate feedback as new +information becomes available now the + + align:start position:0% +information becomes available now the + + + align:start position:0% +information becomes available now the +adoption of CPOE was recommended by the + + align:start position:0% +adoption of CPOE was recommended by the + + + align:start position:0% +adoption of CPOE was recommended by the +National Academy of Medicine they wanted + + align:start position:0% +National Academy of Medicine they wanted + + + align:start position:0% +National Academy of Medicine they wanted +every hospital to use this by by 1999 + + align:start position:0% +every hospital to use this by by 1999 + + + align:start position:0% +every hospital to use this by by 1999 +and of course it hasn't happens + + align:start position:0% +and of course it hasn't happens + + + align:start position:0% +and of course it hasn't happens +I couldn't find current data but 2014 + + align:start position:0% +I couldn't find current data but 2014 + + + align:start position:0% +I couldn't find current data but 2014 +data shows that CPOE for example for + + align:start position:0% +data shows that CPOE for example for + + + align:start position:0% +data shows that CPOE for example for +medication orders is only being used in + + align:start position:0% +medication orders is only being used in + + + align:start position:0% +medication orders is only being used in +about 25 percent of the hospitals and at + + align:start position:0% +about 25 percent of the hospitals and at + + + align:start position:0% +about 25 percent of the hospitals and at +that time people were extrapolating and + + align:start position:0% +that time people were extrapolating and + + + align:start position:0% +that time people were extrapolating and +saying well it's not going to reach 80 + + align:start position:0% +saying well it's not going to reach 80 + + + align:start position:0% +saying well it's not going to reach 80 +percent penetration until the Year 2029 + + align:start position:0% +percent penetration until the Year 2029 + + + align:start position:0% +percent penetration until the Year 2029 +so it's a very slow adoption cycle right + + align:start position:0% +so it's a very slow adoption cycle right + + + align:start position:0% +so it's a very slow adoption cycle right +maybe it's gotten better the other + + align:start position:0% +maybe it's gotten better the other + + + align:start position:0% +maybe it's gotten better the other +problem and one of the reasons for + + align:start position:0% +problem and one of the reasons for + + + align:start position:0% +problem and one of the reasons for +resistance is that it puts additional + + align:start position:0% +resistance is that it puts additional + + + align:start position:0% +resistance is that it puts additional +stresses on people so for example this + + align:start position:0% +stresses on people so for example this + + + align:start position:0% +stresses on people so for example this +is a study of how pharmacists spend + + align:start position:0% +is a study of how pharmacists spend + + + align:start position:0% +is a study of how pharmacists spend +their time and so clinical clinical time + + align:start position:0% +their time and so clinical clinical time + + + align:start position:0% +their time and so clinical clinical time +is useful that's when they're consulting + + align:start position:0% +is useful that's when they're consulting + + + align:start position:0% +is useful that's when they're consulting +with doctors helping them figure out + + align:start position:0% +with doctors helping them figure out + + + align:start position:0% +with doctors helping them figure out +appropriate dosage for patients or + + align:start position:0% +appropriate dosage for patients or + + + align:start position:0% +appropriate dosage for patients or +they're talking to patients explaining + + align:start position:0% +they're talking to patients explaining + + + align:start position:0% +they're talking to patients explaining +to them how to take their medications + + align:start position:0% +to them how to take their medications + + + align:start position:0% +to them how to take their medications +what side effects to watch out for etc + + align:start position:0% +what side effects to watch out for etc + + + align:start position:0% +what side effects to watch out for etc +these distributive tasks it's a funny + + align:start position:0% +these distributive tasks it's a funny + + + align:start position:0% +these distributive tasks it's a funny +term mean the non clinical part of what + + align:start position:0% +term mean the non clinical part of what + + + align:start position:0% +term mean the non clinical part of what +they're doing and what you see is that + + align:start position:0% +they're doing and what you see is that + + + align:start position:0% +they're doing and what you see is that +hospitals that have adopted CPOE they + + align:start position:0% +hospitals that have adopted CPOE they + + + align:start position:0% +hospitals that have adopted CPOE they +wind up spending a little bit more time + + align:start position:0% +wind up spending a little bit more time + + + align:start position:0% +wind up spending a little bit more time +on the distributive tasks and a little + + align:start position:0% +on the distributive tasks and a little + + + align:start position:0% +on the distributive tasks and a little +bit less time on the clinical tasks + + align:start position:0% +bit less time on the clinical tasks + + + align:start position:0% +bit less time on the clinical tasks +which is probably not in the right + + align:start position:0% +which is probably not in the right + + + align:start position:0% +which is probably not in the right +direction in terms of what the + + align:start position:0% +direction in terms of what the + + + align:start position:0% +direction in terms of what the +pharmacists were hoping for out of + + align:start position:0% +pharmacists were hoping for out of + + + align:start position:0% +pharmacists were hoping for out of +systems like this now people have + + align:start position:0% +systems like this now people have + + + align:start position:0% +systems like this now people have +studied the diffusion of new medical + + align:start position:0% +studied the diffusion of new medical + + + align:start position:0% +studied the diffusion of new medical +technologies and I think I'll just show + + align:start position:0% +technologies and I think I'll just show + + + align:start position:0% +technologies and I think I'll just show +you the graph so this is this is in + + align:start position:0% +you the graph so this is this is in + + + align:start position:0% +you the graph so this is this is in +England but this is the adoption for + + align:start position:0% +England but this is the adoption for + + + align:start position:0% +England but this is the adoption for +statins so from the time they were + + align:start position:0% +statins so from the time they were + + + align:start position:0% +statins so from the time they were +introduced + + align:start position:0% +introduced + + + align:start position:0% +introduced +statins is a drug that keeps your + + align:start position:0% +statins is a drug that keeps your + + + align:start position:0% +statins is a drug that keeps your +cholesterol low from the time they were + + align:start position:0% +cholesterol low from the time they were + + + align:start position:0% +cholesterol low from the time they were +introduced until they were being used + + align:start position:0% +introduced until they were being used + + + align:start position:0% +introduced until they were being used +essentially at a hundred percent of + + align:start position:0% +essentially at a hundred percent of + + + align:start position:0% +essentially at a hundred percent of +places was about five and a half six + + align:start position:0% +places was about five and a half six + + + align:start position:0% +places was about five and a half six +years okay + + align:start position:0% +years okay + + + align:start position:0% +years okay +so reasonably fast if you look at the + + align:start position:0% +so reasonably fast if you look at the + + + align:start position:0% +so reasonably fast if you look at the +adoption of magnetic resonance imaging + + align:start position:0% +adoption of magnetic resonance imaging + + + align:start position:0% +adoption of magnetic resonance imaging +technology + + align:start position:0% +technology + + + align:start position:0% +technology +it took five years for it to have any + + align:start position:0% +it took five years for it to have any + + + align:start position:0% +it took five years for it to have any +adoption whatsoever and that's because + + align:start position:0% +adoption whatsoever and that's because + + + align:start position:0% +adoption whatsoever and that's because +it was insanely expensive and so there + + align:start position:0% +it was insanely expensive and so there + + + align:start position:0% +it was insanely expensive and so there +were all kinds of limitations you know + + align:start position:0% +were all kinds of limitations you know + + + align:start position:0% +were all kinds of limitations you know +even in Massachusetts you had to get + + align:start position:0% +even in Massachusetts you had to get + + + align:start position:0% +even in Massachusetts you had to get +permission from some state committee to + + align:start position:0% +permission from some state committee to + + + align:start position:0% +permission from some state committee to +buy a new MRI machine and if another + + align:start position:0% +buy a new MRI machine and if another + + + align:start position:0% +buy a new MRI machine and if another +hospital in your town already had one + + align:start position:0% +hospital in your town already had one + + + align:start position:0% +hospital in your town already had one +then they would say well you shouldn't + + align:start position:0% +then they would say well you shouldn't + + + align:start position:0% +then they would say well you shouldn't +buy one because you should be able to + + align:start position:0% +buy one because you should be able to + + + align:start position:0% +buy one because you should be able to +use this other hospitals MRI machine + + align:start position:0% +use this other hospitals MRI machine + + + align:start position:0% +use this other hospitals MRI machine +same thing happened with CT but as soon + + align:start position:0% +same thing happened with CT but as soon + + + align:start position:0% +same thing happened with CT but as soon +as those limitations were lifted boom + + align:start position:0% +as those limitations were lifted boom + + + align:start position:0% +as those limitations were lifted boom +you know it went up and then continues + + align:start position:0% +you know it went up and then continues + + + align:start position:0% +you know it went up and then continues +to go up + + align:start position:0% +to go up + + + align:start position:0% +to go up +whereas stents I actually don't know why + + align:start position:0% +whereas stents I actually don't know why + + + align:start position:0% +whereas stents I actually don't know why +they were delayed by that long but this + + align:start position:0% +they were delayed by that long but this + + + align:start position:0% +they were delayed by that long but this +is for people with blockages and + + align:start position:0% +is for people with blockages and + + + align:start position:0% +is for people with blockages and +coronary arteries or other arteries you + + align:start position:0% +coronary arteries or other arteries you + + + align:start position:0% +coronary arteries or other arteries you +can put in a little mesh tube that just + + align:start position:0% +can put in a little mesh tube that just + + + align:start position:0% +can put in a little mesh tube that just +keeps that artery open and that adoption + + align:start position:0% +keeps that artery open and that adoption + + + align:start position:0% +keeps that artery open and that adoption +was incredibly quick okay so different + + align:start position:0% +was incredibly quick okay so different + + + align:start position:0% +was incredibly quick okay so different +things get adopted at different rates + + align:start position:0% + + + + align:start position:0% + +now the last topic I want to talk about + + align:start position:0% +now the last topic I want to talk about + + + align:start position:0% +now the last topic I want to talk about +before I yeah so according to those + + align:start position:0% +before I yeah so according to those + + + align:start position:0% +before I yeah so according to those +authors in the case of Stan's there were + + align:start position:0% +authors in the case of Stan's there were + + + align:start position:0% +authors in the case of Stan's there were +some champions of the idea of stenting + + align:start position:0% +some champions of the idea of stenting + + + align:start position:0% +some champions of the idea of stenting +who went around and convinced their + + align:start position:0% +who went around and convinced their + + + align:start position:0% +who went around and convinced their +colleagues that this was the right + + align:start position:0% +colleagues that this was the right + + + align:start position:0% +colleagues that this was the right +technology to use and so there was just + + align:start position:0% +technology to use and so there was just + + + align:start position:0% +technology to use and so there was just +an explosive growth in it in the other + + align:start position:0% +an explosive growth in it in the other + + + align:start position:0% +an explosive growth in it in the other +technologies you know for in the MRI + + align:start position:0% +technologies you know for in the MRI + + + align:start position:0% +technologies you know for in the MRI +case money mattered a lot because + + align:start position:0% +case money mattered a lot because + + + align:start position:0% +case money mattered a lot because +they're so expensive stents are + + align:start position:0% +they're so expensive stents are + + + align:start position:0% +they're so expensive stents are +relatively cheap and in the in the case + + align:start position:0% +relatively cheap and in the in the case + + + align:start position:0% +relatively cheap and in the in the case +of statins those are also relatively + + align:start position:0% +of statins those are also relatively + + + align:start position:0% +of statins those are also relatively +cheap or they've become cheap since they + + align:start position:0% +cheap or they've become cheap since they + + + align:start position:0% +cheap or they've become cheap since they +went off patent originally they were + + align:start position:0% +went off patent originally they were + + + align:start position:0% +went off patent originally they were +they were much more expensive but but + + align:start position:0% +they were much more expensive but but + + + align:start position:0% +they were much more expensive but but +there are still adoption problems so for + + align:start position:0% +there are still adoption problems so for + + + align:start position:0% +there are still adoption problems so for +example there was a recommendation I + + align:start position:0% +example there was a recommendation I + + + align:start position:0% +example there was a recommendation I +think about 15 maybe even 20 years ago + + align:start position:0% +think about 15 maybe even 20 years ago + + + align:start position:0% +think about 15 maybe even 20 years ago +that said that anybody who has had a + + align:start position:0% +that said that anybody who has had a + + + align:start position:0% +that said that anybody who has had a +heart attack or coronary artery disease + + align:start position:0% +heart attack or coronary artery disease + + + align:start position:0% +heart attack or coronary artery disease +should be taking beta blockers and I + + align:start position:0% +should be taking beta blockers and I + + + align:start position:0% +should be taking beta blockers and I +don't remember what the adoption rate is + + align:start position:0% +don't remember what the adoption rate is + + + align:start position:0% +don't remember what the adoption rate is +today but it's it's only on the order of + + align:start position:0% +today but it's it's only on the order of + + + align:start position:0% +today but it's it's only on the order of +a half and so why this is a dirt cheap + + align:start position:0% +a half and so why this is a dirt cheap + + + align:start position:0% +a half and so why this is a dirt cheap +drug for reasons not quite understood it + + align:start position:0% +drug for reasons not quite understood it + + + align:start position:0% +drug for reasons not quite understood it +reduces the probability of having a + + align:start position:0% +reduces the probability of having a + + + align:start position:0% +reduces the probability of having a +second heart attack by about 35% so it's + + align:start position:0% +second heart attack by about 35% so it's + + + align:start position:0% +second heart attack by about 35% so it's +a really cheap protective way of keeping + + align:start position:0% +a really cheap protective way of keeping + + + align:start position:0% +a really cheap protective way of keeping +people healthier and yet it just hasn't + + align:start position:0% +people healthier and yet it just hasn't + + + align:start position:0% +people healthier and yet it just hasn't +suffused practice as much as as people + + align:start position:0% +suffused practice as much as as people + + + align:start position:0% +suffused practice as much as as people +think it should have all right okay so + + align:start position:0% +think it should have all right okay so + + + align:start position:0% +think it should have all right okay so +how do we assure the quality of these + + align:start position:0% +how do we assure the quality of these + + + align:start position:0% +how do we assure the quality of these +technologies before we forced along the + + align:start position:0% +technologies before we forced along the + + + align:start position:0% +technologies before we forced along the +world and this is tricky so Johnny + + align:start position:0% +world and this is tricky so Johnny + + + align:start position:0% +world and this is tricky so Johnny +Anita's a Stanford professor has made an + + align:start position:0% +Anita's a Stanford professor has made an + + + align:start position:0% +Anita's a Stanford professor has made an +extremely successful career out of + + align:start position:0% +extremely successful career out of + + + align:start position:0% +extremely successful career out of +pointing out that most biomedical + + align:start position:0% +pointing out that most biomedical + + + align:start position:0% +pointing out that most biomedical +research is crap + + align:start position:0% +research is crap + + + align:start position:0% +research is crap +it can't be reproduced and there are + + align:start position:0% +it can't be reproduced and there are + + + align:start position:0% +it can't be reproduced and there are +some famous publications that that show + + align:start position:0% +some famous publications that that show + + + align:start position:0% +some famous publications that that show +that people have taken some area of + + align:start position:0% +that people have taken some area of + + + align:start position:0% +that people have taken some area of +biomedicine and they've looked at a + + align:start position:0% +biomedicine and they've looked at a + + + align:start position:0% +biomedicine and they've looked at a +bunch of well-respected published + + align:start position:0% +bunch of well-respected published + + + align:start position:0% +bunch of well-respected published +studies and they've gone to the lab and + + align:start position:0% +studies and they've gone to the lab and + + + align:start position:0% +studies and they've gone to the lab and +they've tried to replicate those studies + + align:start position:0% +they've tried to replicate those studies + + + align:start position:0% +they've tried to replicate those studies +and half the time or three-quarters of + + align:start position:0% +and half the time or three-quarters of + + + align:start position:0% +and half the time or three-quarters of +the time they fail to do so you go oh my + + align:start position:0% +the time they fail to do so you go oh my + + + align:start position:0% +the time they fail to do so you go oh my +god this is horrible + + align:start position:0% +god this is horrible + + + align:start position:0% +god this is horrible +right it is horrible yeah + + align:start position:0% + + + + align:start position:0% + +worse than that so it's not that there + + align:start position:0% +worse than that so it's not that there + + + align:start position:0% +worse than that so it's not that there +are slight differences it's that for + + align:start position:0% +are slight differences it's that for + + + align:start position:0% +are slight differences it's that for +example a result that was shown to be + + align:start position:0% +example a result that was shown to be + + + align:start position:0% +example a result that was shown to be +statistically significant + + align:start position:0% +statistically significant + + + align:start position:0% +statistically significant +in one study when they repeat the study + + align:start position:0% +in one study when they repeat the study + + + align:start position:0% +in one study when they repeat the study +is no longer statistically significant + + align:start position:0% +is no longer statistically significant + + + align:start position:0% +is no longer statistically significant +okay that's bad + + align:start position:0% +okay that's bad + + + align:start position:0% +okay that's bad +if if you base policy on on that kind of + + align:start position:0% +if if you base policy on on that kind of + + + align:start position:0% +if if you base policy on on that kind of +decision so you need EES has a + + align:start position:0% +decision so you need EES has a + + + align:start position:0% +decision so you need EES has a +suggestion which would probably help a + + align:start position:0% +suggestion which would probably help a + + + align:start position:0% +suggestion which would probably help a +lot and that is basically make known to + + align:start position:0% +lot and that is basically make known to + + + align:start position:0% +lot and that is basically make known to +everybody all the studies that have + + align:start position:0% +everybody all the studies that have + + + align:start position:0% +everybody all the studies that have +failed so the problem is that if you + + align:start position:0% +failed so the problem is that if you + + + align:start position:0% +failed so the problem is that if you +give me a big data set and I start + + align:start position:0% +give me a big data set and I start + + + align:start position:0% +give me a big data set and I start +mining this data set I'm gonna find tons + + align:start position:0% +mining this data set I'm gonna find tons + + + align:start position:0% +mining this data set I'm gonna find tons +and tons of interesting correlations in + + align:start position:0% +and tons of interesting correlations in + + + align:start position:0% +and tons of interesting correlations in +this data okay and as soon as I get one + + align:start position:0% +this data okay and as soon as I get one + + + align:start position:0% +this data okay and as soon as I get one +that has a good p-value my students and + + align:start position:0% +that has a good p-value my students and + + + align:start position:0% +that has a good p-value my students and +I go hmm fantastic time to publish right + + align:start position:0% +I go hmm fantastic time to publish right + + + align:start position:0% +I go hmm fantastic time to publish right +now consider the fact that I'm not the + + align:start position:0% +now consider the fact that I'm not the + + + align:start position:0% +now consider the fact that I'm not the +only person in this role so you know + + align:start position:0% +only person in this role so you know + + + align:start position:0% +only person in this role so you know +David's group is doing the same thing + + align:start position:0% +David's group is doing the same thing + + + align:start position:0% +David's group is doing the same thing +and jong-gu togs and Regina barzil ace + + align:start position:0% +and jong-gu togs and Regina barzil ace + + + align:start position:0% +and jong-gu togs and Regina barzil ace +and all of our colleagues at every other + + align:start position:0% +and all of our colleagues at every other + + + align:start position:0% +and all of our colleagues at every other +major University and Hospital in the + + align:start position:0% +major University and Hospital in the + + + align:start position:0% +major University and Hospital in the +United States and so there may be + + align:start position:0% +United States and so there may be + + + align:start position:0% +United States and so there may be +hundreds of people who are mining this + + align:start position:0% +hundreds of people who are mining this + + + align:start position:0% +hundreds of people who are mining this +data and each of us has slightly + + align:start position:0% +data and each of us has slightly + + + align:start position:0% +data and each of us has slightly +different ways of doing it we select our + + align:start position:0% +different ways of doing it we select our + + + align:start position:0% +different ways of doing it we select our +cases differently we pre-process the + + align:start position:0% +cases differently we pre-process the + + + align:start position:0% +cases differently we pre-process the +data differently we apply different + + align:start position:0% +data differently we apply different + + + align:start position:0% +data differently we apply different +learning algorithms to them to them but + + align:start position:0% +learning algorithms to them to them but + + + align:start position:0% +learning algorithms to them to them but +just by random chance some of us + + align:start position:0% +just by random chance some of us + + + align:start position:0% +just by random chance some of us +are going to find interesting results + + align:start position:0% +are going to find interesting results + + + align:start position:0% +are going to find interesting results +interesting patterns and of course those + + align:start position:0% +interesting patterns and of course those + + + align:start position:0% +interesting patterns and of course those +are the ones that get published because + + align:start position:0% +are the ones that get published because + + + align:start position:0% +are the ones that get published because +if you don't find an interesting result + + align:start position:0% +if you don't find an interesting result + + + align:start position:0% +if you don't find an interesting result +you're not going to submit it to a + + align:start position:0% +you're not going to submit it to a + + + align:start position:0% +you're not going to submit it to a +journal and say you know I looked for + + align:start position:0% +journal and say you know I looked for + + + align:start position:0% +journal and say you know I looked for +the following fact phenomenon and I was + + align:start position:0% +the following fact phenomenon and I was + + + align:start position:0% +the following fact phenomenon and I was +unable to find it because the journal + + align:start position:0% +unable to find it because the journal + + + align:start position:0% +unable to find it because the journal +says well that's not interesting to + + align:start position:0% +says well that's not interesting to + + + align:start position:0% +says well that's not interesting to +anybody and so so Ian Edie's is + + align:start position:0% +anybody and so so Ian Edie's is + + + align:start position:0% +anybody and so so Ian Edie's is +recommending that basically every study + + align:start position:0% +recommending that basically every study + + + align:start position:0% +recommending that basically every study +that anybody undertakes should be + + align:start position:0% +that anybody undertakes should be + + + align:start position:0% +that anybody undertakes should be +registered and if you don't get a + + align:start position:0% +registered and if you don't get a + + + align:start position:0% +registered and if you don't get a +significant result that should be known + + align:start position:0% +significant result that should be known + + + align:start position:0% +significant result that should be known +and this would allow us to make at least + + align:start position:0% +and this would allow us to make at least + + + align:start position:0% +and this would allow us to make at least +some reasonable estimate of whether the + + align:start position:0% +some reasonable estimate of whether the + + + align:start position:0% +some reasonable estimate of whether the +significant results that were gotten are + + align:start position:0% +significant results that were gotten are + + + align:start position:0% +significant results that were gotten are +just the statistical outliers that + + align:start position:0% +just the statistical outliers that + + + align:start position:0% +just the statistical outliers that +happen to reach p equal point oh five or + + align:start position:0% +happen to reach p equal point oh five or + + + align:start position:0% +happen to reach p equal point oh five or +whatever your threshold is or whether + + align:start position:0% +whatever your threshold is or whether + + + align:start position:0% +whatever your threshold is or whether +it's a real effect because not that many + + align:start position:0% +it's a real effect because not that many + + + align:start position:0% +it's a real effect because not that many +people have been trying this yeah + + align:start position:0% + + + + align:start position:0% + +it could be any of those it could be + + align:start position:0% +it could be any of those it could be + + + align:start position:0% +it could be any of those it could be +that you know your hospital has some + + align:start position:0% +that you know your hospital has some + + + align:start position:0% +that you know your hospital has some +biased data collection and so you find + + align:start position:0% +biased data collection and so you find + + + align:start position:0% +biased data collection and so you find +in effect my hospital doesn't and so I + + align:start position:0% +in effect my hospital doesn't and so I + + + align:start position:0% +in effect my hospital doesn't and so I +don't find it it could be that we just + + align:start position:0% +don't find it it could be that we just + + + align:start position:0% +don't find it it could be that we just +randomly subsampled a different sample + + align:start position:0% +randomly subsampled a different sample + + + align:start position:0% +randomly subsampled a different sample +of the population + + align:start position:0% +of the population + + + align:start position:0% +of the population +okay so it's very interesting last year + + align:start position:0% +okay so it's very interesting last year + + + align:start position:0% +okay so it's very interesting last year +I was invited to a meeting by Jeff + + align:start position:0% +I was invited to a meeting by Jeff + + + align:start position:0% +I was invited to a meeting by Jeff +Drazen who's the executive editor of the + + align:start position:0% +Drazen who's the executive editor of the + + + align:start position:0% +Drazen who's the executive editor of the +New England Journal and he's thinking + + align:start position:0% +New England Journal and he's thinking + + + align:start position:0% +New England Journal and he's thinking +about has not decided but he's thinking + + align:start position:0% +about has not decided but he's thinking + + + align:start position:0% +about has not decided but he's thinking +about a policy for the New England + + align:start position:0% +about a policy for the New England + + + align:start position:0% +about a policy for the New England +Journal which is like the top Medical + + align:start position:0% +Journal which is like the top Medical + + + align:start position:0% +Journal which is like the top Medical +Journal that says that he will not + + align:start position:0% +Journal that says that he will not + + + align:start position:0% +Journal that says that he will not +publish any result unless it's been + + align:start position:0% +publish any result unless it's been + + + align:start position:0% +publish any result unless it's been +replicated on two independent data sets + + align:start position:0% +replicated on two independent data sets + + + align:start position:0% +replicated on two independent data sets +right so that's interesting and that's + + align:start position:0% +right so that's interesting and that's + + + align:start position:0% +right so that's interesting and that's +an attempt to fight back against this + + align:start position:0% +an attempt to fight back against this + + + align:start position:0% +an attempt to fight back against this +problem it's a different solution than + + align:start position:0% +problem it's a different solution than + + + align:start position:0% +problem it's a different solution than +what what you need is is recommending so + + align:start position:0% +what what you need is is recommending so + + + align:start position:0% +what what you need is is recommending so +this was a study by Enrico Carrara and + + align:start position:0% +this was a study by Enrico Carrara and + + + align:start position:0% +this was a study by Enrico Carrara and +he's talking about what it means to + + align:start position:0% +he's talking about what it means to + + + align:start position:0% +he's talking about what it means to +replicate and again I'm not going to go + + align:start position:0% +replicate and again I'm not going to go + + + align:start position:0% +replicate and again I'm not going to go +through all this but there's a notion of + + align:start position:0% +through all this but there's a notion of + + + align:start position:0% +through all this but there's a notion of +replication might mean exact replication + + align:start position:0% +replication might mean exact replication + + + align:start position:0% +replication might mean exact replication +ie you do exactly the same thing on + + align:start position:0% +ie you do exactly the same thing on + + + align:start position:0% +ie you do exactly the same thing on +exactly the same kind of data but in a + + align:start position:0% +exactly the same kind of data but in a + + + align:start position:0% +exactly the same kind of data but in a +different data set and then partial + + align:start position:0% +different data set and then partial + + + align:start position:0% +different data set and then partial +replication conceptual replication which + + align:start position:0% +replication conceptual replication which + + + align:start position:0% +replication conceptual replication which +says you follow the same procedures but + + align:start position:0% +says you follow the same procedures but + + + align:start position:0% +says you follow the same procedures but +in a different environment and then + + align:start position:0% +in a different environment and then + + + align:start position:0% +in a different environment and then +quasi replication either partial or + + align:start position:0% +quasi replication either partial or + + + align:start position:0% +quasi replication either partial or +conceptual and these have various + + align:start position:0% +conceptual and these have various + + + align:start position:0% +conceptual and these have various +characteristics that you can look at + + align:start position:0% +characteristics that you can look at + + + align:start position:0% +characteristics that you can look at +it's an interesting framework + + align:start position:0% + + + + align:start position:0% + +so this is not a new idea the first + + align:start position:0% +so this is not a new idea the first + + + align:start position:0% +so this is not a new idea the first +edition of this book evaluation methods + + align:start position:0% +edition of this book evaluation methods + + + align:start position:0% +edition of this book evaluation methods +and biomedical informatics was called + + align:start position:0% +and biomedical informatics was called + + + align:start position:0% +and biomedical informatics was called +evaluation methods in medical + + align:start position:0% +evaluation methods in medical + + + align:start position:0% +evaluation methods in medical +informatics by the same authors and was + + align:start position:0% +informatics by the same authors and was + + + align:start position:0% +informatics by the same authors and was +published a long time ago I can't + + align:start position:0% +published a long time ago I can't + + + align:start position:0% +published a long time ago I can't +remember this one is relatively recent + + align:start position:0% +remember this one is relatively recent + + + align:start position:0% +remember this one is relatively recent +and so they do a multi-hundred page very + + align:start position:0% +and so they do a multi-hundred page very + + + align:start position:0% +and so they do a multi-hundred page very +detailed evaluation of exactly how one + + align:start position:0% +detailed evaluation of exactly how one + + + align:start position:0% +detailed evaluation of exactly how one +should evaluate clinical systems like + + align:start position:0% +should evaluate clinical systems like + + + align:start position:0% +should evaluate clinical systems like +this and it's very careful and very + + align:start position:0% +this and it's very careful and very + + + align:start position:0% +this and it's very careful and very +cautious but it's also very conservative + + align:start position:0% +cautious but it's also very conservative + + + align:start position:0% +cautious but it's also very conservative +so for example one of the things that + + align:start position:0% +so for example one of the things that + + + align:start position:0% +so for example one of the things that +they recommend is that the people doing + + align:start position:0% +they recommend is that the people doing + + + align:start position:0% +they recommend is that the people doing +the evaluation should not be the people + + align:start position:0% +the evaluation should not be the people + + + align:start position:0% +the evaluation should not be the people +who developed the technique because + + align:start position:0% +who developed the technique because + + + align:start position:0% +who developed the technique because +there's innately bias and you know I + + align:start position:0% +there's innately bias and you know I + + + align:start position:0% +there's innately bias and you know I +want my technique to succeed and so they + + align:start position:0% +want my technique to succeed and so they + + + align:start position:0% +want my technique to succeed and so they +say hand it off to somebody else who + + align:start position:0% +say hand it off to somebody else who + + + align:start position:0% +say hand it off to somebody else who +doesn't have that same vested interest + + align:start position:0% +doesn't have that same vested interest + + + align:start position:0% +doesn't have that same vested interest +and then you're going to get a more + + align:start position:0% +and then you're going to get a more + + + align:start position:0% +and then you're going to get a more +careful evaluation so Steve Paola and I + + align:start position:0% +careful evaluation so Steve Paola and I + + + align:start position:0% +careful evaluation so Steve Paola and I +wrote a response to one of their early + + align:start position:0% +wrote a response to one of their early + + + align:start position:0% +wrote a response to one of their early +papers recommending this that said well + + align:start position:0% +papers recommending this that said well + + + align:start position:0% +papers recommending this that said well +that's so conservative that it sort of + + align:start position:0% +that's so conservative that it sort of + + + align:start position:0% +that's so conservative that it sort of +throws the baby out with the bathwater + + align:start position:0% +throws the baby out with the bathwater + + + align:start position:0% +throws the baby out with the bathwater +because if you make it so difficult to + + align:start position:0% +because if you make it so difficult to + + + align:start position:0% +because if you make it so difficult to +do an evaluation you'll never get + + align:start position:0% +do an evaluation you'll never get + + + align:start position:0% +do an evaluation you'll never get +anything past it and so we proposed + + align:start position:0% +anything past it and so we proposed + + + align:start position:0% +anything past it and so we proposed +instead a kind of staged evaluation that + + align:start position:0% +instead a kind of staged evaluation that + + + align:start position:0% +instead a kind of staged evaluation that +says first of all you should do + + align:start position:0% +says first of all you should do + + + align:start position:0% +says first of all you should do +regression testing so that every time + + align:start position:0% +regression testing so that every time + + + align:start position:0% +regression testing so that every time +you use these agile development methods + + align:start position:0% +you use these agile development methods + + + align:start position:0% +you use these agile development methods +you should have the set of cases that + + align:start position:0% +you should have the set of cases that + + + align:start position:0% +you should have the set of cases that +your program has worked on before you + + align:start position:0% +your program has worked on before you + + + align:start position:0% +your program has worked on before you +should automatically rerun them and see + + align:start position:0% +should automatically rerun them and see + + + align:start position:0% +should automatically rerun them and see +which ones you've made better and which + + align:start position:0% +which ones you've made better and which + + + align:start position:0% +which ones you've made better and which +ones you've made worse and that'll give + + align:start position:0% +ones you've made worse and that'll give + + + align:start position:0% +ones you've made worse and that'll give +you some insight into whether what + + align:start position:0% +you some insight into whether what + + + align:start position:0% +you some insight into whether what +you're doing is reasonable and then you + + align:start position:0% +you're doing is reasonable and then you + + + align:start position:0% +you're doing is reasonable and then you +might also build tools that look at + + align:start position:0% +might also build tools that look at + + + align:start position:0% +might also build tools that look at +automating ways of looking for + + align:start position:0% +automating ways of looking for + + + align:start position:0% +automating ways of looking for +inconsistencies in the models that + + align:start position:0% +inconsistencies in the models that + + + align:start position:0% +inconsistencies in the models that +you're you're building then you have + + align:start position:0% +you're you're building then you have + + + align:start position:0% +you're you're building then you have +retrospective review judged by + + align:start position:0% +retrospective review judged by + + + align:start position:0% +retrospective review judged by +clinicians so you run a program that you + + align:start position:0% +clinicians so you run a program that you + + + align:start position:0% +clinicians so you run a program that you +like over a hold by + + align:start position:0% +like over a hold by + + + align:start position:0% +like over a hold by +existing data like what you're doing + + align:start position:0% +existing data like what you're doing + + + align:start position:0% +existing data like what you're doing +with mimic or with market scan and then + + align:start position:0% +with mimic or with market scan and then + + + align:start position:0% +with mimic or with market scan and then +you do it prospectively but without + + align:start position:0% +you do it prospectively but without + + + align:start position:0% +you do it prospectively but without +actually affecting patients so you do it + + align:start position:0% +actually affecting patients so you do it + + + align:start position:0% +actually affecting patients so you do it +in real time as the data is coming in + + align:start position:0% +in real time as the data is coming in + + + align:start position:0% +in real time as the data is coming in +but you don't tell anybody what the + + align:start position:0% +but you don't tell anybody what the + + + align:start position:0% +but you don't tell anybody what the +program results in you just ask them to + + align:start position:0% +program results in you just ask them to + + + align:start position:0% +program results in you just ask them to +evaluate in retrospect to see whether it + + align:start position:0% +evaluate in retrospect to see whether it + + + align:start position:0% +evaluate in retrospect to see whether it +was right and you might say well what's + + align:start position:0% +was right and you might say well what's + + + align:start position:0% +was right and you might say well what's +the difference between collecting the + + align:start position:0% +the difference between collecting the + + + align:start position:0% +the difference between collecting the +data in real time and collecting the + + align:start position:0% +data in real time and collecting the + + + align:start position:0% +data in real time and collecting the +data retrospectively and historically + + align:start position:0% +data retrospectively and historically + + + align:start position:0% +data retrospectively and historically +the answer is there is a difference so + + align:start position:0% +the answer is there is a difference so + + + align:start position:0% +the answer is there is a difference so +circumstances differ the mechanisms that + + align:start position:0% +circumstances differ the mechanisms that + + + align:start position:0% +circumstances differ the mechanisms that +you have for collecting the data differ + + align:start position:0% +you have for collecting the data differ + + + align:start position:0% +you have for collecting the data differ +so this turns out to be an important + + align:start position:0% +so this turns out to be an important + + + align:start position:0% +so this turns out to be an important +issue and then you can run a prospective + + align:start position:0% +issue and then you can run a prospective + + + align:start position:0% +issue and then you can run a prospective +controlled trial + + align:start position:0% +controlled trial + + + align:start position:0% +controlled trial +where you're interested in evaluating + + align:start position:0% +where you're interested in evaluating + + + align:start position:0% +where you're interested in evaluating +both the answer that you get from the + + align:start position:0% +both the answer that you get from the + + + align:start position:0% +both the answer that you get from the +program and ultimately the effect on + + align:start position:0% +program and ultimately the effect on + + + align:start position:0% +program and ultimately the effect on +health outcomes so if I have a decision + + align:start position:0% +health outcomes so if I have a decision + + + align:start position:0% +health outcomes so if I have a decision +support system the ultimate proof of the + + align:start position:0% +support system the ultimate proof of the + + + align:start position:0% +support system the ultimate proof of the +pudding is if I run that decision + + align:start position:0% +pudding is if I run that decision + + + align:start position:0% +pudding is if I run that decision +support system I give advice to + + align:start position:0% +support system I give advice to + + + align:start position:0% +support system I give advice to +clinicians the clinicians change their + + align:start position:0% +clinicians the clinicians change their + + + align:start position:0% +clinicians the clinicians change their +behavior sometimes and the patients get + + align:start position:0% +behavior sometimes and the patients get + + + align:start position:0% +behavior sometimes and the patients get +a better outcome then I'm convinced that + + align:start position:0% +a better outcome then I'm convinced that + + + align:start position:0% +a better outcome then I'm convinced that +this is really useful but you have to + + align:start position:0% +this is really useful but you have to + + + align:start position:0% +this is really useful but you have to +get there slowly because you don't want + + align:start position:0% +get there slowly because you don't want + + + align:start position:0% +get there slowly because you don't want +to give them worse outcomes that's + + align:start position:0% +to give them worse outcomes that's + + + align:start position:0% +to give them worse outcomes that's +unethical and probably illegal + + align:start position:0% + + + + align:start position:0% + +and you want to compare this to the + + align:start position:0% +and you want to compare this to the + + + align:start position:0% +and you want to compare this to the +performance of unaided doctors so the + + align:start position:0% +performance of unaided doctors so the + + + align:start position:0% +performance of unaided doctors so the +Food and Drug Administration has been + + align:start position:0% +Food and Drug Administration has been + + + align:start position:0% +Food and Drug Administration has been +dealing with this issue for many many + + align:start position:0% +dealing with this issue for many many + + + align:start position:0% +dealing with this issue for many many +years I remember talking to them in + + align:start position:0% +years I remember talking to them in + + + align:start position:0% +years I remember talking to them in +about 1976 when they were reading about + + align:start position:0% +about 1976 when they were reading about + + + align:start position:0% +about 1976 when they were reading about +the very first expert system programs + + align:start position:0% +the very first expert system programs + + + align:start position:0% +the very first expert system programs +for diagnosis and therapy selection and + + align:start position:0% +for diagnosis and therapy selection and + + + align:start position:0% +for diagnosis and therapy selection and +they said well how should we regulate + + align:start position:0% +they said well how should we regulate + + + align:start position:0% +they said well how should we regulate +these and my response at the time was + + align:start position:0% +these and my response at the time was + + + align:start position:0% +these and my response at the time was +god help us keep your hands off right + + align:start position:0% +god help us keep your hands off right + + + align:start position:0% +god help us keep your hands off right +because if you regulate it then you're + + align:start position:0% +because if you regulate it then you're + + + align:start position:0% +because if you regulate it then you're +gonna slow down progress and in any case + + align:start position:0% +gonna slow down progress and in any case + + + align:start position:0% +gonna slow down progress and in any case +none of these programs are being used + + align:start position:0% +none of these programs are being used + + + align:start position:0% +none of these programs are being used +these programs that are being developed + + align:start position:0% +these programs that are being developed + + + align:start position:0% +these programs that are being developed +as experimental programs in experimental + + align:start position:0% +as experimental programs in experimental + + + align:start position:0% +as experimental programs in experimental +settings they're not coming anywhere + + align:start position:0% +settings they're not coming anywhere + + + align:start position:0% +settings they're not coming anywhere +close to being used on real patients and + + align:start position:0% +close to being used on real patients and + + + align:start position:0% +close to being used on real patients and +so there's not a regulatory issue and + + align:start position:0% +so there's not a regulatory issue and + + + align:start position:0% +so there's not a regulatory issue and +about every five years FDA has revisited + + align:start position:0% +about every five years FDA has revisited + + + align:start position:0% +about every five years FDA has revisited +that question and they have continued to + + align:start position:0% +that question and they have continued to + + + align:start position:0% +that question and they have continued to +make essentially the same decision based + + align:start position:0% +make essentially the same decision based + + + align:start position:0% +make essentially the same decision based +on the rationale that for example they + + align:start position:0% +on the rationale that for example they + + + align:start position:0% +on the rationale that for example they +don't regulate books if I write a + + align:start position:0% +don't regulate books if I write a + + + align:start position:0% +don't regulate books if I write a +textbook that explains something about + + align:start position:0% +textbook that explains something about + + + align:start position:0% +textbook that explains something about +medicine the FDA is not going to see + + align:start position:0% +medicine the FDA is not going to see + + + align:start position:0% +medicine the FDA is not going to see +whether it's correct or not and the + + align:start position:0% +whether it's correct or not and the + + + align:start position:0% +whether it's correct or not and the +reason is because the expectation is + + align:start position:0% +reason is because the expectation is + + + align:start position:0% +reason is because the expectation is +that the textbook is making + + align:start position:0% +that the textbook is making + + + align:start position:0% +that the textbook is making +recommendations so to speak to clinical + + align:start position:0% +recommendations so to speak to clinical + + + align:start position:0% +recommendations so to speak to clinical +practitioners who are responsible + + align:start position:0% +practitioners who are responsible + + + align:start position:0% +practitioners who are responsible +experts themselves and so the ultimate + + align:start position:0% +experts themselves and so the ultimate + + + align:start position:0% +experts themselves and so the ultimate +responsibility for how they behave rests + + align:start position:0% +responsibility for how they behave rests + + + align:start position:0% +responsibility for how they behave rests +with them and not with the textbook and + + align:start position:0% +with them and not with the textbook and + + + align:start position:0% +with them and not with the textbook and +they said we're gonna treat these + + align:start position:0% +they said we're gonna treat these + + + align:start position:0% +they said we're gonna treat these +computer programs as if they were + + align:start position:0% +computer programs as if they were + + + align:start position:0% +computer programs as if they were +dynamic textbooks rather than colleagues + + align:start position:0% +dynamic textbooks rather than colleagues + + + align:start position:0% +dynamic textbooks rather than colleagues +who are acting independently and giving + + align:start position:0% +who are acting independently and giving + + + align:start position:0% +who are acting independently and giving +advice now as soon as you try to give + + align:start position:0% +advice now as soon as you try to give + + + align:start position:0% +advice now as soon as you try to give +that advice not to a professional but to + + align:start position:0% +that advice not to a professional but to + + + align:start position:0% +that advice not to a professional but to +a patient then you are immediately under + + align:start position:0% +a patient then you are immediately under + + + align:start position:0% +a patient then you are immediately under +the regulatory auspices of FDA because + + align:start position:0% +the regulatory auspices of FDA because + + + align:start position:0% +the regulatory auspices of FDA because +now there is no professional + + align:start position:0% +now there is no professional + + + align:start position:0% +now there is no professional +intermediate that can evaluate the + + align:start position:0% +intermediate that can evaluate the + + + align:start position:0% +intermediate that can evaluate the +quality of that advice so what FDA has + + align:start position:0% +quality of that advice so what FDA has + + + align:start position:0% +quality of that advice so what FDA has +done it just in the past year is they + + align:start position:0% +done it just in the past year is they + + + align:start position:0% +done it just in the past year is they +said that we're going to treat these AI + + align:start position:0% +said that we're going to treat these AI + + + align:start position:0% +said that we're going to treat these AI +based quote-unquote devices as medical + + align:start position:0% +based quote-unquote devices as medical + + + align:start position:0% +based quote-unquote devices as medical +devices and we're going to apply the + + align:start position:0% +devices and we're going to apply the + + + align:start position:0% +devices and we're going to apply the +same regulatory requirements that we + + align:start position:0% +same regulatory requirements that we + + + align:start position:0% +same regulatory requirements that we +have for these devices except we don't + + align:start position:0% +have for these devices except we don't + + + align:start position:0% +have for these devices except we don't +really know how to do this and so + + align:start position:0% +really know how to do this and so + + + align:start position:0% +really know how to do this and so +there's a kind of experiment going on + + align:start position:0% +there's a kind of experiment going on + + + align:start position:0% +there's a kind of experiment going on +right now where they're saying okay + + align:start position:0% +right now where they're saying okay + + + align:start position:0% +right now where they're saying okay +we're submit applications for review of + + align:start position:0% +we're submit applications for review of + + + align:start position:0% +we're submit applications for review of +these devices to us we will review them + + align:start position:0% +these devices to us we will review them + + + align:start position:0% +these devices to us we will review them +and we will use these criteria product + + align:start position:0% +and we will use these criteria product + + + align:start position:0% +and we will use these criteria product +quality patient safety clinical + + align:start position:0% +quality patient safety clinical + + + align:start position:0% +quality patient safety clinical +responsibility cybersecurity + + align:start position:0% +responsibility cybersecurity + + + align:start position:0% +responsibility cybersecurity +responsibility and a so-called proactive + + align:start position:0% +responsibility and a so-called proactive + + + align:start position:0% +responsibility and a so-called proactive +culture in the organization that's + + align:start position:0% +culture in the organization that's + + + align:start position:0% +culture in the organization that's +developing them in order to make a + + align:start position:0% +developing them in order to make a + + + align:start position:0% +developing them in order to make a +judgement of whether or not to let you + + align:start position:0% +judgement of whether or not to let you + + + align:start position:0% +judgement of whether or not to let you +proceed with marketing one of these + + align:start position:0% +proceed with marketing one of these + + + align:start position:0% +proceed with marketing one of these +things so if you look there are in fact + + align:start position:0% +things so if you look there are in fact + + + align:start position:0% +things so if you look there are in fact +about ten devices quote unquote these + + align:start position:0% +about ten devices quote unquote these + + + align:start position:0% +about ten devices quote unquote these +are all software that have been approved + + align:start position:0% +are all software that have been approved + + + align:start position:0% +are all software that have been approved +so far by FDA and almost all of them are + + align:start position:0% +so far by FDA and almost all of them are + + + align:start position:0% +so far by FDA and almost all of them are +imaging devices they're they're things + + align:start position:0% +imaging devices they're they're things + + + align:start position:0% +imaging devices they're they're things +that do convolutional networks over one + + align:start position:0% +that do convolutional networks over one + + + align:start position:0% +that do convolutional networks over one +thing or another and so here are just a + + align:start position:0% +thing or another and so here are just a + + + align:start position:0% +thing or another and so here are just a +few examples + + align:start position:0% +few examples + + + align:start position:0% +few examples +Imogen has osteo detect which analyzes + + align:start position:0% +Imogen has osteo detect which analyzes + + + align:start position:0% +Imogen has osteo detect which analyzes +two dimensional x-ray images for signs + + align:start position:0% +two dimensional x-ray images for signs + + + align:start position:0% +two dimensional x-ray images for signs +of distal radius fracture so if you + + align:start position:0% +of distal radius fracture so if you + + + align:start position:0% +of distal radius fracture so if you +break your wrist then this system will + + align:start position:0% +break your wrist then this system will + + + align:start position:0% +break your wrist then this system will +look at the x-ray and and decide whether + + align:start position:0% +look at the x-ray and and decide whether + + + align:start position:0% +look at the x-ray and and decide whether +or not you've done that + + align:start position:0% +or not you've done that + + + align:start position:0% +or not you've done that +here's one from idx which looks at the + + align:start position:0% +here's one from idx which looks at the + + + align:start position:0% +here's one from idx which looks at the +photographs of your retina and decides + + align:start position:0% +photographs of your retina and decides + + + align:start position:0% +photographs of your retina and decides +whether you have diabetic retinopathy + + align:start position:0% +whether you have diabetic retinopathy + + + align:start position:0% +whether you have diabetic retinopathy +and actually they've published a lot of + + align:start position:0% +and actually they've published a lot of + + + align:start position:0% +and actually they've published a lot of +papers that show that they can also + + align:start position:0% +papers that show that they can also + + + align:start position:0% +papers that show that they can also +identify heart disease and stroke risk + + align:start position:0% +identify heart disease and stroke risk + + + align:start position:0% +identify heart disease and stroke risk +and various other things from those same + + align:start position:0% +and various other things from those same + + + align:start position:0% +and various other things from those same +photographs so FDA has granted them + + align:start position:0% +photographs so FDA has granted them + + + align:start position:0% +photographs so FDA has granted them +approval to market this thing + + align:start position:0% +approval to market this thing + + + align:start position:0% +approval to market this thing +another one is vis which + + align:start position:0% +another one is vis which + + + align:start position:0% +another one is vis which +automatically analyzes CT scans for ER + + align:start position:0% +automatically analyzes CT scans for ER + + + align:start position:0% +automatically analyzes CT scans for ER +patients and is looking for blockages in + + align:start position:0% +patients and is looking for blockages in + + + align:start position:0% +patients and is looking for blockages in +major brain blood vessels so this can + + align:start position:0% +major brain blood vessels so this can + + + align:start position:0% +major brain blood vessels so this can +obviously lead to a stroke and this is + + align:start position:0% +obviously lead to a stroke and this is + + + align:start position:0% +obviously lead to a stroke and this is +an automated technique that does that + + align:start position:0% +an automated technique that does that + + + align:start position:0% +an automated technique that does that +and here's another one + + align:start position:0% +and here's another one + + + align:start position:0% +and here's another one +our Duras measures and tracks tumors or + + align:start position:0% +our Duras measures and tracks tumors or + + + align:start position:0% +our Duras measures and tracks tumors or +potential cancers in radiology images so + + align:start position:0% +potential cancers in radiology images so + + + align:start position:0% +potential cancers in radiology images so +these are the the ones that have been + + align:start position:0% +these are the the ones that have been + + + align:start position:0% +these are the the ones that have been +approved and then I just wanted to + + align:start position:0% +approved and then I just wanted to + + + align:start position:0% +approved and then I just wanted to +remind you that there's actually plenty + + align:start position:0% +remind you that there's actually plenty + + + align:start position:0% +remind you that there's actually plenty +of literature about this kind of stuff + + align:start position:0% +of literature about this kind of stuff + + + align:start position:0% +of literature about this kind of stuff +so the book on the left actually comes + + align:start position:0% +so the book on the left actually comes + + + align:start position:0% +so the book on the left actually comes +out next week and I got to read a + + align:start position:0% +out next week and I got to read a + + + align:start position:0% +out next week and I got to read a +preprint of it by Eric Topol who's one + + align:start position:0% +preprint of it by Eric Topol who's one + + + align:start position:0% +preprint of it by Eric Topol who's one +of these doctors who writes a lot about + + align:start position:0% +of these doctors who writes a lot about + + + align:start position:0% +of these doctors who writes a lot about +the future of Medicine + + align:start position:0% +the future of Medicine + + + align:start position:0% +the future of Medicine +and he actually goes through tons and + + align:start position:0% +and he actually goes through tons and + + + align:start position:0% +and he actually goes through tons and +tons of examples of not only the systems + + align:start position:0% +tons of examples of not only the systems + + + align:start position:0% +tons of examples of not only the systems +that have been approved by FDA but also + + align:start position:0% +that have been approved by FDA but also + + + align:start position:0% +that have been approved by FDA but also +things that are in the works that he's + + align:start position:0% +things that are in the works that he's + + + align:start position:0% +things that are in the works that he's +very optimistic that these will again + + align:start position:0% +very optimistic that these will again + + + align:start position:0% +very optimistic that these will again +revolutionize the practice of medicine + + align:start position:0% +revolutionize the practice of medicine + + + align:start position:0% +revolutionize the practice of medicine +Bob Walker who wrote the book on the + + align:start position:0% +Bob Walker who wrote the book on the + + + align:start position:0% +Bob Walker who wrote the book on the +left a couple of years ago is a little + + align:start position:0% +left a couple of years ago is a little + + + align:start position:0% +left a couple of years ago is a little +bit more cautious because he's chief of + + align:start position:0% +bit more cautious because he's chief of + + + align:start position:0% +bit more cautious because he's chief of +medicine at UC San Francisco and he + + align:start position:0% +medicine at UC San Francisco and he + + + align:start position:0% +medicine at UC San Francisco and he +wrote this book in response to them + + align:start position:0% +wrote this book in response to them + + + align:start position:0% +wrote this book in response to them +almost killing a kid by giving him a 39 + + align:start position:0% +almost killing a kid by giving him a 39 + + + align:start position:0% +almost killing a kid by giving him a 39 +X overdose of a medication they didn't + + align:start position:0% +X overdose of a medication they didn't + + + align:start position:0% +X overdose of a medication they didn't +quite succeed in killing the kids so it + + align:start position:0% +quite succeed in killing the kids so it + + + align:start position:0% +quite succeed in killing the kids so it +turned out okay but he was really + + align:start position:0% +turned out okay but he was really + + + align:start position:0% +turned out okay but he was really +concerned about how this wonderful + + align:start position:0% +concerned about how this wonderful + + + align:start position:0% +concerned about how this wonderful +technology led to such a disastrous + + align:start position:0% +technology led to such a disastrous + + + align:start position:0% +technology led to such a disastrous +outcome and so he spent a year studying + + align:start position:0% +outcome and so he spent a year studying + + + align:start position:0% +outcome and so he spent a year studying +how these systems are being used and + + align:start position:0% +how these systems are being used and + + + align:start position:0% +how these systems are being used and +write some more cautionary tale okay so + + align:start position:0% +write some more cautionary tale okay so + + + align:start position:0% +write some more cautionary tale okay so +let me turn to Adam who as I said is a + + align:start position:0% +let me turn to Adam who as I said is a + + + align:start position:0% +let me turn to Adam who as I said is a +professor at at the Brigham in Harvard + + align:start position:0% +professor at at the Brigham in Harvard + + + align:start position:0% +professor at at the Brigham in Harvard +Medical School and please come and join + + align:start position:0% +Medical School and please come and join + + + align:start position:0% +Medical School and please come and join +me and we can have a conversation so my + + align:start position:0% +me and we can have a conversation so my + + + align:start position:0% +me and we can have a conversation so my +name is Adam Wright I'm an associate + + align:start position:0% +name is Adam Wright I'm an associate + + + align:start position:0% +name is Adam Wright I'm an associate +professor of medicine at Harvard Medical + + align:start position:0% +professor of medicine at Harvard Medical + + + align:start position:0% +professor of medicine at Harvard Medical +School and that + + align:start position:0% +School and that + + + align:start position:0% +School and that +I lead a research program and I teach + + align:start position:0% +I lead a research program and I teach + + + align:start position:0% +I lead a research program and I teach +the introduction to biomedical + + align:start position:0% +the introduction to biomedical + + + align:start position:0% +the introduction to biomedical +informatics at courses at the Medical + + align:start position:0% +informatics at courses at the Medical + + + align:start position:0% +informatics at courses at the Medical +School so if you're interested in the + + align:start position:0% +School so if you're interested in the + + + align:start position:0% +School so if you're interested in the +topics that Pete was talking about today + + align:start position:0% +topics that Pete was talking about today + + + align:start position:0% +topics that Pete was talking about today +you should definitely consider cross + + align:start position:0% +you should definitely consider cross + + + align:start position:0% +you should definitely consider cross +registering and BMI 701 or 702 at the + + align:start position:0% +registering and BMI 701 or 702 at the + + + align:start position:0% +registering and BMI 701 or 702 at the +medical school we certainly always could + + align:start position:0% +medical school we certainly always could + + + align:start position:0% +medical school we certainly always could +use a few more enthusiastic + + align:start position:0% +use a few more enthusiastic + + + align:start position:0% +use a few more enthusiastic +technically-minded machine learning + + align:start position:0% +technically-minded machine learning + + + align:start position:0% +technically-minded machine learning +experts in our in our course and then I + + align:start position:0% +experts in our in our course and then I + + + align:start position:0% +experts in our in our course and then I +have a operational job at partners + + align:start position:0% +have a operational job at partners + + + align:start position:0% +have a operational job at partners +partners is the health system that + + align:start position:0% +partners is the health system that + + + align:start position:0% +partners is the health system that +includes Mass General Hospital and the + + align:start position:0% +includes Mass General Hospital and the + + + align:start position:0% +includes Mass General Hospital and the +Brigham and the nessam community + + align:start position:0% +Brigham and the nessam community + + + align:start position:0% +Brigham and the nessam community +hospitals and I work on partners II care + + align:start position:0% +hospitals and I work on partners II care + + + align:start position:0% +hospitals and I work on partners II care +which is our kind of cool brand name for + + align:start position:0% +which is our kind of cool brand name for + + + align:start position:0% +which is our kind of cool brand name for +it for epic so epic is a HR these are + + align:start position:0% +it for epic so epic is a HR these are + + + align:start position:0% +it for epic so epic is a HR these are +partners and I helped oversee the + + align:start position:0% +partners and I helped oversee the + + + align:start position:0% +partners and I helped oversee the +clinical decision support there so we + + align:start position:0% +clinical decision support there so we + + + align:start position:0% +clinical decision support there so we +have a decision support team I am the + + align:start position:0% +have a decision support team I am the + + + align:start position:0% +have a decision support team I am the +clinical lead for monitoring and + + align:start position:0% +clinical lead for monitoring and + + + align:start position:0% +clinical lead for monitoring and +evaluation and so I help make sure that + + align:start position:0% +evaluation and so I help make sure that + + + align:start position:0% +evaluation and so I help make sure that +our decision support systems of the the + + align:start position:0% +our decision support systems of the the + + + align:start position:0% +our decision support systems of the the +type that Pete's talking about working + + align:start position:0% +type that Pete's talking about working + + + align:start position:0% +type that Pete's talking about working +correctly so that's my job at the + + align:start position:0% +correctly so that's my job at the + + + align:start position:0% +correctly so that's my job at the +Brigham and Partners cool and and I + + align:start position:0% +Brigham and Partners cool and and I + + + align:start position:0% +Brigham and Partners cool and and I +appreciate it very much thanks I + + align:start position:0% +appreciate it very much thanks I + + + align:start position:0% +appreciate it very much thanks I +appreciate invitation it's fun to be + + align:start position:0% +appreciate invitation it's fun to be + + + align:start position:0% +appreciate invitation it's fun to be +here + + align:start position:0% +here + + + align:start position:0% +here +so Adam first obvious question is so + + align:start position:0% +so Adam first obvious question is so + + + align:start position:0% +so Adam first obvious question is so +what kind of decision support systems + + align:start position:0% +what kind of decision support systems + + + align:start position:0% +what kind of decision support systems +have you guys actually put in place + + align:start position:0% +have you guys actually put in place + + + align:start position:0% +have you guys actually put in place +absolutely so I mean you know we've had + + align:start position:0% +absolutely so I mean you know we've had + + + align:start position:0% +absolutely so I mean you know we've had +a long history at the Brigham and + + align:start position:0% +a long history at the Brigham and + + + align:start position:0% +a long history at the Brigham and +partners of using decision support + + align:start position:0% +partners of using decision support + + + align:start position:0% +partners of using decision support +historically we developed our own + + align:start position:0% +historically we developed our own + + + align:start position:0% +historically we developed our own +electronic health record which was a + + align:start position:0% +electronic health record which was a + + + align:start position:0% +electronic health record which was a +little bit unusual about three years ago + + align:start position:0% +little bit unusual about three years ago + + + align:start position:0% +little bit unusual about three years ago +we switched from our self-developed + + align:start position:0% +we switched from our self-developed + + + align:start position:0% +we switched from our self-developed +system to epic which is a very widely + + align:start position:0% +system to epic which is a very widely + + + align:start position:0% +system to epic which is a very widely +used a commercial electronic health + + align:start position:0% +used a commercial electronic health + + + align:start position:0% +used a commercial electronic health +record and to the point that you gave + + align:start position:0% +record and to the point that you gave + + + align:start position:0% +record and to the point that you gave +we've really started with a lot of + + align:start position:0% +we've really started with a lot of + + + align:start position:0% +we've really started with a lot of +medication related decision support so + + align:start position:0% +medication related decision support so + + + align:start position:0% +medication related decision support so +that's things like drug interaction + + align:start position:0% +that's things like drug interaction + + + align:start position:0% +that's things like drug interaction +alerting so you prescribe two drugs that + + align:start position:0% +alerting so you prescribe two drugs that + + + align:start position:0% +alerting so you prescribe two drugs that +might interact with each other and we + + align:start position:0% +might interact with each other and we + + + align:start position:0% +might interact with each other and we +use a table you know no machine learning + + align:start position:0% +use a table you know no machine learning + + + align:start position:0% +use a table you know no machine learning +and complicated that says we think this + + align:start position:0% +and complicated that says we think this + + + align:start position:0% +and complicated that says we think this +drug might interact with this we raise + + align:start position:0% +drug might interact with this we raise + + + align:start position:0% +drug might interact with this we raise +an alert to the doctor and the + + align:start position:0% +an alert to the doctor and the + + + align:start position:0% +an alert to the doctor and the +pharmacist and they make a decision + + align:start position:0% +pharmacist and they make a decision + + + align:start position:0% +pharmacist and they make a decision +using their expertise as as the limited + + align:start position:0% +using their expertise as as the limited + + + align:start position:0% +using their expertise as as the limited +intermediary but we're going to continue + + align:start position:0% +intermediary but we're going to continue + + + align:start position:0% +intermediary but we're going to continue +with that prescription + + align:start position:0% +with that prescription + + + align:start position:0% +with that prescription +let's have some dosing support allergy + + align:start position:0% +let's have some dosing support allergy + + + align:start position:0% +let's have some dosing support allergy +checking and things like that so our + + align:start position:0% +checking and things like that so our + + + align:start position:0% +checking and things like that so our +first kind of set of decision support + + align:start position:0% +first kind of set of decision support + + + align:start position:0% +first kind of set of decision support +really was around medications and then + + align:start position:0% +really was around medications and then + + + align:start position:0% +really was around medications and then +we turned to kind of a broader set of + + align:start position:0% +we turned to kind of a broader set of + + + align:start position:0% +we turned to kind of a broader set of +things like preventive care reminders so + + align:start position:0% +things like preventive care reminders so + + + align:start position:0% +things like preventive care reminders so +identifying patients that are overdue + + align:start position:0% +identifying patients that are overdue + + + align:start position:0% +identifying patients that are overdue +for a mammogram or a pap smear or the + + align:start position:0% +for a mammogram or a pap smear or the + + + align:start position:0% +for a mammogram or a pap smear or the +might benefit from a statin or something + + align:start position:0% +might benefit from a statin or something + + + align:start position:0% +might benefit from a statin or something +like that + + align:start position:0% +like that + + + align:start position:0% +like that +or a beta blocker in the case of acute + + align:start position:0% +or a beta blocker in the case of acute + + + align:start position:0% +or a beta blocker in the case of acute +marital friction and we make suggestions + + align:start position:0% +marital friction and we make suggestions + + + align:start position:0% +marital friction and we make suggestions +to the doctor or to other members of the + + align:start position:0% +to the doctor or to other members of the + + + align:start position:0% +to the doctor or to other members of the +care team to do those things again those + + align:start position:0% +care team to do those things again those + + + align:start position:0% +care team to do those things again those +historically have largely been + + align:start position:0% +historically have largely been + + + align:start position:0% +historically have largely been +rule-based + + align:start position:0% +rule-based + + + align:start position:0% +rule-based +so some experts sat down and wrote + + align:start position:0% +so some experts sat down and wrote + + + align:start position:0% +so some experts sat down and wrote +boolean if-then rules using variables + + align:start position:0% +boolean if-then rules using variables + + + align:start position:0% +boolean if-then rules using variables +that are in a patient's chart we have + + align:start position:0% +that are in a patient's chart we have + + + align:start position:0% +that are in a patient's chart we have +increasingly though started trying to + + align:start position:0% +increasingly though started trying to + + + align:start position:0% +increasingly though started trying to +use some predictive models for things + + align:start position:0% +use some predictive models for things + + + align:start position:0% +use some predictive models for things +like readmission or with their patients + + align:start position:0% +like readmission or with their patients + + + align:start position:0% +like readmission or with their patients +at risk of falling down in the hospital + + align:start position:0% +at risk of falling down in the hospital + + + align:start position:0% +at risk of falling down in the hospital +a big problem that patients often + + align:start position:0% +a big problem that patients often + + + align:start position:0% +a big problem that patients often +encounter is they're in the hospital you + + align:start position:0% +encounter is they're in the hospital you + + + align:start position:0% +encounter is they're in the hospital you +know they're kind of delirious the + + align:start position:0% +know they're kind of delirious the + + + align:start position:0% +know they're kind of delirious the +hospital is a weird place and start to + + align:start position:0% +hospital is a weird place and start to + + + align:start position:0% +hospital is a weird place and start to +get it to go to the bathroom they trip + + align:start position:0% +get it to go to the bathroom they trip + + + align:start position:0% +get it to go to the bathroom they trip +on there you know IV tubing and then + + align:start position:0% +on there you know IV tubing and then + + + align:start position:0% +on there you know IV tubing and then +they fall and are injured and so we + + align:start position:0% +they fall and are injured and so we + + + align:start position:0% +they fall and are injured and so we +would like to prevent that from + + align:start position:0% +would like to prevent that from + + + align:start position:0% +would like to prevent that from +happening cuz it's obviously kind of a + + align:start position:0% +happening cuz it's obviously kind of a + + + align:start position:0% +happening cuz it's obviously kind of a +bad thing happen to you what's here in + + align:start position:0% +bad thing happen to you what's here in + + + align:start position:0% +bad thing happen to you what's here in +the hospital and so we have some machine + + align:start position:0% +the hospital and so we have some machine + + + align:start position:0% +the hospital and so we have some machine +learning based tools for predicting + + align:start position:0% +learning based tools for predicting + + + align:start position:0% +learning based tools for predicting +patients that are at risk for Falls and + + align:start position:0% +patients that are at risk for Falls and + + + align:start position:0% +patients that are at risk for Falls and +then there is a set of you know + + align:start position:0% +then there is a set of you know + + + align:start position:0% +then there is a set of you know +interventions like putting the bed rails + + align:start position:0% +interventions like putting the bed rails + + + align:start position:0% +interventions like putting the bed rails +up or putting an alarm that buzzes when + + align:start position:0% +up or putting an alarm that buzzes when + + + align:start position:0% +up or putting an alarm that buzzes when +they're if they get out of bed or in + + align:start position:0% +they're if they get out of bed or in + + + align:start position:0% +they're if they get out of bed or in +more extreme cases having a sitter like + + align:start position:0% +more extreme cases having a sitter like + + + align:start position:0% +more extreme cases having a sitter like +a person who actually sits in the room + + align:start position:0% +a person who actually sits in the room + + + align:start position:0% +a person who actually sits in the room +with them and tries to keep them from + + align:start position:0% +with them and tries to keep them from + + + align:start position:0% +with them and tries to keep them from +getting up or assists them to the + + align:start position:0% +getting up or assists them to the + + + align:start position:0% +getting up or assists them to the +bathroom and we call someone who can + + align:start position:0% +bathroom and we call someone who can + + + align:start position:0% +bathroom and we call someone who can +assist them to the bathroom so we have + + align:start position:0% +assist them to the bathroom so we have + + + align:start position:0% +assist them to the bathroom so we have +increasingly started using those machine + + align:start position:0% +increasingly started using those machine + + + align:start position:0% +increasingly started using those machine +learning tools some of which we get from + + align:start position:0% +learning tools some of which we get from + + + align:start position:0% +learning tools some of which we get from +third parties like from our electronic + + align:start position:0% +third parties like from our electronic + + + align:start position:0% +third parties like from our electronic +health record vendor and some of which + + align:start position:0% +health record vendor and some of which + + + align:start position:0% +health record vendor and some of which +we sort of train ourselves on our own + + align:start position:0% +we sort of train ourselves on our own + + + align:start position:0% +we sort of train ourselves on our own +data that's a newer pursuit for us is + + align:start position:0% +data that's a newer pursuit for us is + + + align:start position:0% +data that's a newer pursuit for us is +this machine learning so when you have + + align:start position:0% +this machine learning so when you have + + + align:start position:0% +this machine learning so when you have +something like a risk model how do you + + align:start position:0% +something like a risk model how do you + + + align:start position:0% +something like a risk model how do you +decide where to set the threshold you + + align:start position:0% +decide where to set the threshold you + + + align:start position:0% +decide where to set the threshold you +know if I'm at 53 percent risk of + + align:start position:0% +know if I'm at 53 percent risk of + + + align:start position:0% +know if I'm at 53 percent risk of +falling yeah should you get a sitter to + + align:start position:0% +falling yeah should you get a sitter to + + + align:start position:0% +falling yeah should you get a sitter to +sit by my age it's complicated right I + + align:start position:0% +sit by my age it's complicated right I + + + align:start position:0% +sit by my age it's complicated right I +mean I would like to say that what we do + + align:start position:0% +mean I would like to say that what we do + + + align:start position:0% +mean I would like to say that what we do +is sort of a full kind of you know + + align:start position:0% +is sort of a full kind of you know + + + align:start position:0% +is sort of a full kind of you know +utility analysis right where we say we + + align:start position:0% +utility analysis right where we say we + + + align:start position:0% +utility analysis right where we say we +pay a sitter this much per hour and the + + align:start position:0% +pay a sitter this much per hour and the + + + align:start position:0% +pay a sitter this much per hour and the +risk of falling is this much and the + + align:start position:0% +risk of falling is this much and the + + + align:start position:0% +risk of falling is this much and the +cost of a fall you know most patients + + align:start position:0% +cost of a fall you know most patients + + + align:start position:0% +cost of a fall you know most patients +who fall aren't hurt but some are and so + + align:start position:0% +who fall aren't hurt but some are and so + + + align:start position:0% +who fall aren't hurt but some are and so +you would sort of calculate the you know + + align:start position:0% +you would sort of calculate the you know + + + align:start position:0% +you would sort of calculate the you know +the cost benefit of each of those things + + align:start position:0% +the cost benefit of each of those things + + + align:start position:0% +the cost benefit of each of those things +and you know sort of figure out where on + + align:start position:0% +and you know sort of figure out where on + + + align:start position:0% +and you know sort of figure out where on +the ROC curve if you want to put place + + align:start position:0% +the ROC curve if you want to put place + + + align:start position:0% +the ROC curve if you want to put place +yourself in practice I think we often + + align:start position:0% +yourself in practice I think we often + + + align:start position:0% +yourself in practice I think we often +just play it by ear in part because a + + align:start position:0% +just play it by ear in part because a + + + align:start position:0% +just play it by ear in part because a +lot of our things are intended to be + + align:start position:0% +lot of our things are intended to be + + + align:start position:0% +lot of our things are intended to be +suggestions right so so our threshold + + align:start position:0% +suggestions right so so our threshold + + + align:start position:0% +suggestions right so so our threshold +for saying to the doctor hey this + + align:start position:0% +for saying to the doctor hey this + + + align:start position:0% +for saying to the doctor hey this +patient is that elevated risk for fall + + align:start position:0% +patient is that elevated risk for fall + + + align:start position:0% +patient is that elevated risk for fall +consider doing something is pretty low + + align:start position:0% +consider doing something is pretty low + + + align:start position:0% +consider doing something is pretty low +if the system works a automatically + + align:start position:0% +if the system works a automatically + + + align:start position:0% +if the system works a automatically +ordering a sitter we might set it higher + + align:start position:0% +ordering a sitter we might set it higher + + + align:start position:0% +ordering a sitter we might set it higher +I would say that's an area + + align:start position:0% +I would say that's an area + + + align:start position:0% +I would say that's an area +of of research I would also say that one + + align:start position:0% +of of research I would also say that one + + + align:start position:0% +of of research I would also say that one +challenge we have we often set and + + align:start position:0% +challenge we have we often set and + + + align:start position:0% +challenge we have we often set and +forget these kinds of systems right and + + align:start position:0% +forget these kinds of systems right and + + + align:start position:0% +forget these kinds of systems right and +so there's you know kind of feature + + align:start position:0% +so there's you know kind of feature + + + align:start position:0% +so there's you know kind of feature +drift in patience change over time we + + align:start position:0% +drift in patience change over time we + + + align:start position:0% +drift in patience change over time we +probably should do a better job of then + + align:start position:0% +probably should do a better job of then + + + align:start position:0% +probably should do a better job of then +looking back to see how well they're + + align:start position:0% +looking back to see how well they're + + + align:start position:0% +looking back to see how well they're +actually working and making tweaks to + + align:start position:0% +actually working and making tweaks to + + + align:start position:0% +actually working and making tweaks to +the thresholds but these are of course + + align:start position:0% +the thresholds but these are of course + + + align:start position:0% +the thresholds but these are of course +very complicated decisions + + align:start position:0% +very complicated decisions + + + align:start position:0% +very complicated decisions +really I remember fifty years ago + + align:start position:0% +really I remember fifty years ago + + + align:start position:0% +really I remember fifty years ago +talking to some people in the Air Force + + align:start position:0% +talking to some people in the Air Force + + + align:start position:0% +talking to some people in the Air Force +yeah about how much should they invest + + align:start position:0% +yeah about how much should they invest + + + align:start position:0% +yeah about how much should they invest +invest in safety measures and and they + + align:start position:0% +invest in safety measures and and they + + + align:start position:0% +invest in safety measures and and they +had a utility theoretic model that said + + align:start position:0% +had a utility theoretic model that said + + + align:start position:0% +had a utility theoretic model that said +ok how much does it cost to replace a + + align:start position:0% +ok how much does it cost to replace a + + + align:start position:0% +ok how much does it cost to replace a +pilot if you kill him yeah yeah yeah + + align:start position:0% +pilot if you kill him yeah yeah yeah + + + align:start position:0% +pilot if you kill him yeah yeah yeah +yeah and this was not publicized a lot I + + align:start position:0% +yeah and this was not publicized a lot I + + + align:start position:0% +yeah and this was not publicized a lot I +mean we do calculate things like quality + + align:start position:0% +mean we do calculate things like quality + + + align:start position:0% +mean we do calculate things like quality +adjusted life years and disability + + align:start position:0% +adjusted life years and disability + + + align:start position:0% +adjusted life years and disability +adjusted life years so there is in all + + align:start position:0% +adjusted life years so there is in all + + + align:start position:0% +adjusted life years so there is in all +of medicine right is people that deploy + + align:start position:0% +of medicine right is people that deploy + + + align:start position:0% +of medicine right is people that deploy +resources kind of in this calculus and I + + align:start position:0% +resources kind of in this calculus and I + + + align:start position:0% +resources kind of in this calculus and I +think we tend to a sign of really high + + align:start position:0% +think we tend to a sign of really high + + + align:start position:0% +think we tend to a sign of really high +weight to patient harm right because + + align:start position:0% +weight to patient harm right because + + + align:start position:0% +weight to patient harm right because +patient harm is the if you think about + + align:start position:0% +patient harm is the if you think about + + + align:start position:0% +patient harm is the if you think about +the kind of the the oath the doctors + + align:start position:0% +the kind of the the oath the doctors + + + align:start position:0% +the kind of the the oath the doctors +swear right first do no harm like the + + align:start position:0% +swear right first do no harm like the + + + align:start position:0% +swear right first do no harm like the +worst thing we can do is harm you in the + + align:start position:0% +worst thing we can do is harm you in the + + + align:start position:0% +worst thing we can do is harm you in the +hospital so I think we have a pretty + + align:start position:0% +hospital so I think we have a pretty + + + align:start position:0% +hospital so I think we have a pretty +strong aversion to do that but it's hard + + align:start position:0% +strong aversion to do that but it's hard + + + align:start position:0% +strong aversion to do that but it's hard +to it's very hard to weigh these things + + align:start position:0% +to it's very hard to weigh these things + + + align:start position:0% +to it's very hard to weigh these things +I think one of the challenges we often + + align:start position:0% +I think one of the challenges we often + + + align:start position:0% +I think one of the challenges we often +run into is that different doctors would + + align:start position:0% +run into is that different doctors would + + + align:start position:0% +run into is that different doctors would +make different decisions right so if you + + align:start position:0% +make different decisions right so if you + + + align:start position:0% +make different decisions right so if you +put the same patient in front of 10 + + align:start position:0% +put the same patient in front of 10 + + + align:start position:0% +put the same patient in front of 10 +doctors and said does this patient need + + align:start position:0% +doctors and said does this patient need + + + align:start position:0% +doctors and said does this patient need +a sitter maybe half would say yes and + + align:start position:0% +a sitter maybe half would say yes and + + + align:start position:0% +a sitter maybe half would say yes and +half would say no and so it's especially + + align:start position:0% +half would say no and so it's especially + + + align:start position:0% +half would say no and so it's especially +hard to know what to do with a decision + + align:start position:0% +hard to know what to do with a decision + + + align:start position:0% +hard to know what to do with a decision +support system if the humans can't agree + + align:start position:0% +support system if the humans can't agree + + + align:start position:0% +support system if the humans can't agree +on what you should do in the so the + + align:start position:0% +on what you should do in the so the + + + align:start position:0% +on what you should do in the so the +other thing we talked about on the phone + + align:start position:0% +other thing we talked about on the phone + + + align:start position:0% +other thing we talked about on the phone +yesterday is I was concerned a few years + + align:start position:0% +yesterday is I was concerned a few years + + + align:start position:0% +yesterday is I was concerned a few years +ago I was visiting one of these August + + align:start position:0% +ago I was visiting one of these August + + + align:start position:0% +ago I was visiting one of these August +Boston area hospitals and and asked to + + align:start position:0% +Boston area hospitals and and asked to + + + align:start position:0% +Boston area hospitals and and asked to +see a an example of somebody interacting + + align:start position:0% +see a an example of somebody interacting + + + align:start position:0% +see a an example of somebody interacting +with this computerized physician order + + align:start position:0% +with this computerized physician order + + + align:start position:0% +with this computerized physician order +entry system and the the senior resident + + align:start position:0% +entry system and the the senior resident + + + align:start position:0% +entry system and the the senior resident +who was taking me around went up to the + + align:start position:0% +who was taking me around went up to the + + + align:start position:0% +who was taking me around went up to the +computer and said well I think I + + align:start position:0% +computer and said well I think I + + + align:start position:0% +computer and said well I think I +remember how to use this and I said wait + + align:start position:0% +remember how to use this and I said wait + + + align:start position:0% +remember how to use this and I said wait +a minute + + align:start position:0% +a minute + + + align:start position:0% +a minute +this is something you were expected to + + align:start position:0% +this is something you were expected to + + + align:start position:0% +this is something you were expected to +use daily + + align:start position:0% +use daily + + + align:start position:0% +use daily +but in reality what happens is that it's + + align:start position:0% +but in reality what happens is that it's + + + align:start position:0% +but in reality what happens is that it's +not the senior doctors or even the + + align:start position:0% +not the senior doctors or even the + + + align:start position:0% +not the senior doctors or even the +medium senior doctors it's it's the + + align:start position:0% +medium senior doctors it's it's the + + + align:start position:0% +medium senior doctors it's it's the +interns on the junior residents who + + align:start position:0% +interns on the junior residents who + + + align:start position:0% +interns on the junior residents who +actually use the system's Easter yeah + + align:start position:0% +actually use the system's Easter yeah + + + align:start position:0% +actually use the system's Easter yeah +and the concern I had was that it takes + + align:start position:0% +and the concern I had was that it takes + + + align:start position:0% +and the concern I had was that it takes +a junior resident with a lot of guts to + + align:start position:0% +a junior resident with a lot of guts to + + + align:start position:0% +a junior resident with a lot of guts to +go up to the you know chief of your + + align:start position:0% +go up to the you know chief of your + + + align:start position:0% +go up to the you know chief of your +service and say dr. X even though you + + align:start position:0% +service and say dr. X even though you + + + align:start position:0% +service and say dr. X even though you +asked me to order this drug for this + + align:start position:0% +asked me to order this drug for this + + + align:start position:0% +asked me to order this drug for this +patient the computer is arguing back + + align:start position:0% +patient the computer is arguing back + + + align:start position:0% +patient the computer is arguing back +that you should use this other one + + align:start position:0% +that you should use this other one + + + align:start position:0% +that you should use this other one +instead yeah it does and in fact I + + align:start position:0% +instead yeah it does and in fact I + + + align:start position:0% +instead yeah it does and in fact I +actually thought about this a little + + align:start position:0% +actually thought about this a little + + + align:start position:0% +actually thought about this a little +more after we chatted about it and we've + + align:start position:0% +more after we chatted about it and we've + + + align:start position:0% +more after we chatted about it and we've +heard from residents that people said to + + align:start position:0% +heard from residents that people said to + + + align:start position:0% +heard from residents that people said to +them if you dare page me with an epic + + align:start position:0% +them if you dare page me with an epic + + + align:start position:0% +them if you dare page me with an epic +suggestion in the middle of the night + + align:start position:0% +suggestion in the middle of the night + + + align:start position:0% +suggestion in the middle of the night +I'll never talk to you again so you know + + align:start position:0% +I'll never talk to you again so you know + + + align:start position:0% +I'll never talk to you again so you know +just override all of those alerts so I + + align:start position:0% +just override all of those alerts so I + + + align:start position:0% +just override all of those alerts so I +think that you know one of the + + align:start position:0% +think that you know one of the + + + align:start position:0% +think that you know one of the +challenges says and there's some you + + align:start position:0% +challenges says and there's some you + + + align:start position:0% +challenges says and there's some you +know as a cool billionaire on our part + + align:start position:0% +know as a cool billionaire on our part + + + align:start position:0% +know as a cool billionaire on our part +is that a lot of these alerts we give + + align:start position:0% +is that a lot of these alerts we give + + + align:start position:0% +is that a lot of these alerts we give +are you know to have a PPV of like you + + align:start position:0% +are you know to have a PPV of like you + + + align:start position:0% +are you know to have a PPV of like you +know ten or twenty percent right you + + align:start position:0% +know ten or twenty percent right you + + + align:start position:0% +know ten or twenty percent right you +know they are usually wrong it's we + + align:start position:0% +know they are usually wrong it's we + + + align:start position:0% +know they are usually wrong it's we +think it's really important so we really + + align:start position:0% +think it's really important so we really + + + align:start position:0% +think it's really important so we really +raised these or it's a lot but people + + align:start position:0% +raised these or it's a lot but people + + + align:start position:0% +raised these or it's a lot but people +experience this kind of alert fatigue or + + align:start position:0% +experience this kind of alert fatigue or + + + align:start position:0% +experience this kind of alert fatigue or +what people call alarm fatigue you see + + align:start position:0% +what people call alarm fatigue you see + + + align:start position:0% +what people call alarm fatigue you see +this in cockpits too but people get too + + align:start position:0% +this in cockpits too but people get too + + + align:start position:0% +this in cockpits too but people get too +many alerts and they start ignoring the + + align:start position:0% +many alerts and they start ignoring the + + + align:start position:0% +many alerts and they start ignoring the +alert so they assume that they're wrong + + align:start position:0% +alert so they assume that they're wrong + + + align:start position:0% +alert so they assume that they're wrong +they tell the resident not to page them + + align:start position:0% +they tell the resident not to page them + + + align:start position:0% +they tell the resident not to page them +in the moment I know no matter what the + + align:start position:0% +in the moment I know no matter what the + + + align:start position:0% +in the moment I know no matter what the +computer says so I do think that we have + + align:start position:0% +computer says so I do think that we have + + + align:start position:0% +computer says so I do think that we have +some some responsibility to improve the + + align:start position:0% +some some responsibility to improve the + + + align:start position:0% +some some responsibility to improve the +accuracy of these alerts and I do think + + align:start position:0% +accuracy of these alerts and I do think + + + align:start position:0% +accuracy of these alerts and I do think +you know machine learning could help us + + align:start position:0% +you know machine learning could help us + + + align:start position:0% +you know machine learning could help us +we're actually just having a meeting + + align:start position:0% +we're actually just having a meeting + + + align:start position:0% +we're actually just having a meeting +about a pneumococcal vaccination alert + + align:start position:0% +about a pneumococcal vaccination alert + + + align:start position:0% +about a pneumococcal vaccination alert +system it helps people remember to + + align:start position:0% +system it helps people remember to + + + align:start position:0% +system it helps people remember to +prescribe this facts they should help + + align:start position:0% +prescribe this facts they should help + + + align:start position:0% +prescribe this facts they should help +you not get pneumonia and it takes four + + align:start position:0% +you not get pneumonia and it takes four + + + align:start position:0% +you not get pneumonia and it takes four +or five variables into account and we + + align:start position:0% +or five variables into account and we + + + align:start position:0% +or five variables into account and we +started looking at the cases when people + + align:start position:0% +started looking at the cases when people + + + align:start position:0% +started looking at the cases when people +would override the alert and they were + + align:start position:0% +would override the alert and they were + + + align:start position:0% +would override the alert and they were +mostly appropriate right so the patient + + align:start position:0% +mostly appropriate right so the patient + + + align:start position:0% +mostly appropriate right so the patient +is you know in a really extreme state + + align:start position:0% +is you know in a really extreme state + + + align:start position:0% +is you know in a really extreme state +right now or conversely the patient is + + align:start position:0% +right now or conversely the patient is + + + align:start position:0% +right now or conversely the patient is +close to the end of life and they're not + + align:start position:0% +close to the end of life and they're not + + + align:start position:0% +close to the end of life and they're not +going to benefit from this vaccination + + align:start position:0% +going to benefit from this vaccination + + + align:start position:0% +going to benefit from this vaccination +or patient has a phobia of needles the + + align:start position:0% +or patient has a phobia of needles the + + + align:start position:0% +or patient has a phobia of needles the +patient has an insurance problem and we + + align:start position:0% +patient has an insurance problem and we + + + align:start position:0% +patient has an insurance problem and we +think there's probably more like 30 or + + align:start position:0% +think there's probably more like 30 or + + + align:start position:0% +think there's probably more like 30 or +40 variables that you would need to take + + align:start position:0% +40 variables that you would need to take + + + align:start position:0% +40 variables that you would need to take +into account to make that really + + align:start position:0% +into account to make that really + + + align:start position:0% +into account to make that really +accurate and so the question is many of + + align:start position:0% +accurate and so the question is many of + + + align:start position:0% +accurate and so the question is many of +that many variables + + align:start position:0% +that many variables + + + align:start position:0% +that many variables +can a human develop and maintain that + + align:start position:0% +can a human develop and maintain that + + + align:start position:0% +can a human develop and maintain that +logic + + align:start position:0% +logic + + + align:start position:0% +logic +or would we be better off trying to use + + align:start position:0% +or would we be better off trying to use + + + align:start position:0% +or would we be better off trying to use +a machine learning system to do that + + align:start position:0% +a machine learning system to do that + + + align:start position:0% +a machine learning system to do that +would that really work or not it's so so + + align:start position:0% +would that really work or not it's so so + + + align:start position:0% +would that really work or not it's so so +how far are we from being able to use + + align:start position:0% +how far are we from being able to use + + + align:start position:0% +how far are we from being able to use +the machine learning system to do that + + align:start position:0% +the machine learning system to do that + + + align:start position:0% +the machine learning system to do that +yeah I think that the biggest challenge + + align:start position:0% +yeah I think that the biggest challenge + + + align:start position:0% +yeah I think that the biggest challenge +honestly relates to this group available + + align:start position:0% +honestly relates to this group available + + + align:start position:0% +honestly relates to this group available +in accuracy of the data in our systems + + align:start position:0% +in accuracy of the data in our systems + + + align:start position:0% +in accuracy of the data in our systems +so epoch which is the EHR that we're + + align:start position:0% +so epoch which is the EHR that we're + + + align:start position:0% +so epoch which is the EHR that we're +using and Cerner and all scripts and + + align:start position:0% +using and Cerner and all scripts and + + + align:start position:0% +using and Cerner and all scripts and +mostly major systems have various ways + + align:start position:0% +mostly major systems have various ways + + + align:start position:0% +mostly major systems have various ways +to run even kind of sophisticated + + align:start position:0% +to run even kind of sophisticated + + + align:start position:0% +to run even kind of sophisticated +machine learning models either inside of + + align:start position:0% +machine learning models either inside of + + + align:start position:0% +machine learning models either inside of +the system or sort of kind of bolted on + + align:start position:0% +the system or sort of kind of bolted on + + + align:start position:0% +the system or sort of kind of bolted on +to the system than feeding model + + align:start position:0% +to the system than feeding model + + + align:start position:0% +to the system than feeding model +inferences back into their to the system + + align:start position:0% +inferences back into their to the system + + + align:start position:0% +inferences back into their to the system +when I was giving that example in + + align:start position:0% +when I was giving that example in + + + align:start position:0% +when I was giving that example in +pneumococcal vaccination one of the + + align:start position:0% +pneumococcal vaccination one of the + + + align:start position:0% +pneumococcal vaccination one of the +major problems is that there's not + + align:start position:0% +major problems is that there's not + + + align:start position:0% +major problems is that there's not +always a really good structured way in + + align:start position:0% +always a really good structured way in + + + align:start position:0% +always a really good structured way in +the system that we indicate that a + + align:start position:0% +the system that we indicate that a + + + align:start position:0% +the system that we indicate that a +patient is at the end of life and + + align:start position:0% +patient is at the end of life and + + + align:start position:0% +patient is at the end of life and +receiving comfort measures only or the + + align:start position:0% +receiving comfort measures only or the + + + align:start position:0% +receiving comfort measures only or the +patient is in a really extreme state + + align:start position:0% +patient is in a really extreme state + + + align:start position:0% +patient is in a really extreme state +that we're in the middle of the code + + align:start position:0% +that we're in the middle of the code + + + align:start position:0% +that we're in the middle of the code +blue and that we need to sort of pause + + align:start position:0% +blue and that we need to sort of pause + + + align:start position:0% +blue and that we need to sort of pause +for a second it's not given you know + + align:start position:0% +for a second it's not given you know + + + align:start position:0% +for a second it's not given you know +these kind of friendly preventive care + + align:start position:0% +these kind of friendly preventive care + + + align:start position:0% +these kind of friendly preventive care +suggestions and so I would actually say + + align:start position:0% +suggestions and so I would actually say + + + align:start position:0% +suggestions and so I would actually say +that the biggest barrier to really good + + align:start position:0% +that the biggest barrier to really good + + + align:start position:0% +that the biggest barrier to really good +machine learning based decision support + + align:start position:0% +machine learning based decision support + + + align:start position:0% +machine learning based decision support +is just the the lack of good reliably + + align:start position:0% +is just the the lack of good reliably + + + align:start position:0% +is just the the lack of good reliably +documented coded useable features I + + align:start position:0% +documented coded useable features I + + + align:start position:0% +documented coded useable features I +think that the second challenge on + + align:start position:0% +think that the second challenge on + + + align:start position:0% +think that the second challenge on +Hugh's work flow right you said sort of + + align:start position:0% +Hugh's work flow right you said sort of + + + align:start position:0% +Hugh's work flow right you said sort of +you know it's sometimes hard to know in + + align:start position:0% +you know it's sometimes hard to know in + + + align:start position:0% +you know it's sometimes hard to know in +the hospital who a patient's doctor is + + align:start position:0% +the hospital who a patient's doctor is + + + align:start position:0% +the hospital who a patient's doctor is +right the patient is admitted and on the + + align:start position:0% +right the patient is admitted and on the + + + align:start position:0% +right the patient is admitted and on the +care team is an intern a junior resident + + align:start position:0% +care team is an intern a junior resident + + + align:start position:0% +care team is an intern a junior resident +and a fellow and attending several + + align:start position:0% +and a fellow and attending several + + + align:start position:0% +and a fellow and attending several +specialists a couple of nurses and who + + align:start position:0% +specialists a couple of nurses and who + + + align:start position:0% +specialists a couple of nurses and who +should get that message or who should + + align:start position:0% +should get that message or who should + + + align:start position:0% +should get that message or who should +get that page workflow is second my this + + align:start position:0% +get that page workflow is second my this + + + align:start position:0% +get that page workflow is second my this +is where I think a you may sister I have + + align:start position:0% +is where I think a you may sister I have + + + align:start position:0% +is where I think a you may sister I have +some optimism I actually think that the + + align:start position:0% +some optimism I actually think that the + + + align:start position:0% +some optimism I actually think that the +technical ability of our EHR software to + + align:start position:0% +technical ability of our EHR software to + + + align:start position:0% +technical ability of our EHR software to +run these models is is better than it + + align:start position:0% +run these models is is better than it + + + align:start position:0% +run these models is is better than it +was three or five years ago and it's + + align:start position:0% +was three or five years ago and it's + + + align:start position:0% +was three or five years ago and it's +actually usually not the barrier we've + + align:start position:0% +actually usually not the barrier we've + + + align:start position:0% +actually usually not the barrier we've +done so there there were attempts again + + align:start position:0% +done so there there were attempts again + + + align:start position:0% +done so there there were attempts again +20 years ago to create kind of formal + + align:start position:0% +20 years ago to create kind of formal + + + align:start position:0% +20 years ago to create kind of formal +rules about who gets notified under what + + align:start position:0% +rules about who gets notified under what + + + align:start position:0% +rules about who gets notified under what +circumstances I remember one of the + + align:start position:0% +circumstances I remember one of the + + + align:start position:0% +circumstances I remember one of the +doctors I worked with at Tufts Medical + + align:start position:0% +doctors I worked with at Tufts Medical + + + align:start position:0% +doctors I worked with at Tufts Medical +Center was going crazy because that when + + align:start position:0% +Center was going crazy because that when + + + align:start position:0% +Center was going crazy because that when +they implemented a new lab information + + align:start position:0% +they implemented a new lab information + + + align:start position:0% +they implemented a new lab information +system it would alert on every other lab + + align:start position:0% +system it would alert on every other lab + + + align:start position:0% +system it would alert on every other lab +right + + align:start position:0% +right + + + align:start position:0% +right +this is crazy but there were other + + align:start position:0% +this is crazy but there were other + + + align:start position:0% +this is crazy but there were other +hospitals that said well let's be a + + align:start position:0% +hospitals that said well let's be a + + + align:start position:0% +hospitals that said well let's be a +little more sophisticated about when + + align:start position:0% +little more sophisticated about when + + + align:start position:0% +little more sophisticated about when +it's necessary to alert and then if + + align:start position:0% +it's necessary to alert and then if + + + align:start position:0% +it's necessary to alert and then if +somebody doesn't respond to an alert + + align:start position:0% +somebody doesn't respond to an alert + + + align:start position:0% +somebody doesn't respond to an alert +within a very short period of time then + + align:start position:0% +within a very short period of time then + + + align:start position:0% +within a very short period of time then +we escalate it to somebody higher up or + + align:start position:0% +we escalate it to somebody higher up or + + + align:start position:0% +we escalate it to somebody higher up or +somebody else on the care team and that + + align:start position:0% +somebody else on the care team and that + + + align:start position:0% +somebody else on the care team and that +seemed like a reasonable idea to me but + + align:start position:0% +seemed like a reasonable idea to me but + + + align:start position:0% +seemed like a reasonable idea to me but +are there things like that in place now + + align:start position:0% +are there things like that in place now + + + align:start position:0% +are there things like that in place now +there are it works very differently the + + align:start position:0% +there are it works very differently the + + + align:start position:0% +there are it works very differently the +inpatient and the outpatient setting + + align:start position:0% +inpatient and the outpatient setting + + + align:start position:0% +inpatient and the outpatient setting +right the inpatient setting were writing + + align:start position:0% +right the inpatient setting were writing + + + align:start position:0% +right the inpatient setting were writing +very kind of acute care to a patient and + + align:start position:0% +very kind of acute care to a patient and + + + align:start position:0% +very kind of acute care to a patient and +so we have processes where people sort + + align:start position:0% +so we have processes where people sort + + + align:start position:0% +so we have processes where people sort +of sign in and out of the the care team + + align:start position:0% +of sign in and out of the the care team + + + align:start position:0% +of sign in and out of the the care team +and in fact these sort of prevalence of + + align:start position:0% +and in fact these sort of prevalence of + + + align:start position:0% +and in fact these sort of prevalence of +these automated messages is an incentive + + align:start position:0% +these automated messages is an incentive + + + align:start position:0% +these automated messages is an incentive +to sort of do that well right so if I go + + align:start position:0% +to sort of do that well right so if I go + + + align:start position:0% +to sort of do that well right so if I go +home I better sign myself out of that + + align:start position:0% +home I better sign myself out of that + + + align:start position:0% +home I better sign myself out of that +patient otherwise I'm gonna get all + + align:start position:0% +patient otherwise I'm gonna get all + + + align:start position:0% +patient otherwise I'm gonna get all +these pages all night about them and the + + align:start position:0% +these pages all night about them and the + + + align:start position:0% +these pages all night about them and the +system sort of well you don't always + + align:start position:0% +system sort of well you don't always + + + align:start position:0% +system sort of well you don't always +make sure that somebody is they're + + align:start position:0% +make sure that somebody is they're + + + align:start position:0% +make sure that somebody is they're +responding a provider it becomes a + + align:start position:0% +responding a provider it becomes a + + + align:start position:0% +responding a provider it becomes a +little thorny er in the outpatient + + align:start position:0% +little thorny er in the outpatient + + + align:start position:0% +little thorny er in the outpatient +setting right because a lot of e to the + + align:start position:0% +setting right because a lot of e to the + + + align:start position:0% +setting right because a lot of e to the +academic doctors at the Brigham only + + align:start position:0% +academic doctors at the Brigham only + + + align:start position:0% +academic doctors at the Brigham only +have clinic you know half a day a week + + align:start position:0% +have clinic you know half a day a week + + + align:start position:0% +have clinic you know half a day a week +and so the question is if an abnormal + + align:start position:0% +and so the question is if an abnormal + + + align:start position:0% +and so the question is if an abnormal +result comes back should I send it to + + align:start position:0% +result comes back should I send it to + + + align:start position:0% +result comes back should I send it to +that doctor should I send it to the + + align:start position:0% +that doctor should I send it to the + + + align:start position:0% +that doctor should I send it to the +person sort of on-call in that clinic + + align:start position:0% +person sort of on-call in that clinic + + + align:start position:0% +person sort of on-call in that clinic +should I send it to the to the head of + + align:start position:0% +should I send it to the to the head of + + + align:start position:0% +should I send it to the to the head of +the clinic there are also these sort of + + align:start position:0% +the clinic there are also these sort of + + + align:start position:0% +the clinic there are also these sort of +edge cases that sort of mess us up a lot + + align:start position:0% +edge cases that sort of mess us up a lot + + + align:start position:0% +edge cases that sort of mess us up a lot +right and so a classic one is a patient + + align:start position:0% +right and so a classic one is a patient + + + align:start position:0% +right and so a classic one is a patient +is in the hospital I've ordered some lab + + align:start position:0% +is in the hospital I've ordered some lab + + + align:start position:0% +is in the hospital I've ordered some lab +tests they're looking well so I + + align:start position:0% +tests they're looking well so I + + + align:start position:0% +tests they're looking well so I +discharged the patient the test is still + + align:start position:0% +discharged the patient the test is still + + + align:start position:0% +discharged the patient the test is still +pending at the time the patient is + + align:start position:0% +pending at the time the patient is + + + align:start position:0% +pending at the time the patient is +discharged and now who does that go to + + align:start position:0% +discharged and now who does that go to + + + align:start position:0% +discharged and now who does that go to +like it to go to the patient's primary + + align:start position:0% +like it to go to the patient's primary + + + align:start position:0% +like it to go to the patient's primary +care doctor do they have a primary care + + align:start position:0% +care doctor do they have a primary care + + + align:start position:0% +care doctor do they have a primary care +doctor should it go to the person who + + align:start position:0% +doctor should it go to the person who + + + align:start position:0% +doctor should it go to the person who +ordered the tests that person may be on + + align:start position:0% +ordered the tests that person may be on + + + align:start position:0% +ordered the tests that person may be on +vacation now if it's a test that kind of + + align:start position:0% +vacation now if it's a test that kind of + + + align:start position:0% +vacation now if it's a test that kind of +takes him he wants to come back so he + + align:start position:0% +takes him he wants to come back so he + + + align:start position:0% +takes him he wants to come back so he +still circled with all those tea pads + + align:start position:0% +still circled with all those tea pads + + + align:start position:0% +still circled with all those tea pads +tests pending a district we still circle + + align:start position:0% +tests pending a district we still circle + + + align:start position:0% +tests pending a district we still circle +with some someone's edge cases but I + + align:start position:0% +with some someone's edge cases but I + + + align:start position:0% +with some someone's edge cases but I +think in the core we're pretty good at + + align:start position:0% +think in the core we're pretty good at + + + align:start position:0% +think in the core we're pretty good at +it + + align:start position:0% + + + + align:start position:0% + +so one of the things we talked about is + + align:start position:0% +so one of the things we talked about is + + + align:start position:0% +so one of the things we talked about is +an experience I've had and you've + + align:start position:0% +an experience I've had and you've + + + align:start position:0% +an experience I've had and you've +probably had that for example a few + + align:start position:0% +probably had that for example a few + + + align:start position:0% +probably had that for example a few +years ago I was working with the people + + align:start position:0% +years ago I was working with the people + + + align:start position:0% +years ago I was working with the people +who run the clinical labs at Mass + + align:start position:0% +who run the clinical labs at Mass + + + align:start position:0% +who run the clinical labs at Mass +General and they run some ancient + + align:start position:0% +General and they run some ancient + + + align:start position:0% +General and they run some ancient +laboratory information systems that as + + align:start position:0% +laboratory information systems that as + + + align:start position:0% +laboratory information systems that as +you said can add and subtract but + + align:start position:0% +you said can add and subtract but + + + align:start position:0% +you said can add and subtract but +multiply or divide + + align:start position:0% + + + + align:start position:0% + +it doesn't support negative numbers only + + align:start position:0% +it doesn't support negative numbers only + + + align:start position:0% +it doesn't support negative numbers only +unsigned integers so there are these + + align:start position:0% +unsigned integers so there are these + + + align:start position:0% +unsigned integers so there are these +wonderful legacy systems around that + + align:start position:0% +wonderful legacy systems around that + + + align:start position:0% +wonderful legacy systems around that +that really create horrendous problems + + align:start position:0% +that really create horrendous problems + + + align:start position:0% +that really create horrendous problems +because if you try to build anything I + + align:start position:0% +because if you try to build anything I + + + align:start position:0% +because if you try to build anything I +mean even a risk prediction calculator + + align:start position:0% +mean even a risk prediction calculator + + + align:start position:0% +mean even a risk prediction calculator +it really helps to be able to divide + + align:start position:0% +it really helps to be able to divide + + + align:start position:0% +it really helps to be able to divide +sure was multiplying and so we've + + align:start position:0% +sure was multiplying and so we've + + + align:start position:0% +sure was multiplying and so we've +struggled in that project and I'm sure + + align:start position:0% +struggled in that project and I'm sure + + + align:start position:0% +struggled in that project and I'm sure +you've had similar experiences with how + + align:start position:0% +you've had similar experiences with how + + + align:start position:0% +you've had similar experiences with how +do we incorporate a decision support + + align:start position:0% +do we incorporate a decision support + + + align:start position:0% +do we incorporate a decision support +system into some of this Cree Heald + + align:start position:0% +system into some of this Cree Heald + + + align:start position:0% +system into some of this Cree Heald +technology that that just doesn't + + align:start position:0% +technology that that just doesn't + + + align:start position:0% +technology that that just doesn't +support it yeah so what what's the right + + align:start position:0% +support it yeah so what what's the right + + + align:start position:0% +support it yeah so what what's the right +approach there are a lot of + + align:start position:0% +approach there are a lot of + + + align:start position:0% +approach there are a lot of +architectures and they all have pros and + + align:start position:0% +architectures and they all have pros and + + + align:start position:0% +architectures and they all have pros and +cons I'm not sure if any one of them is + + align:start position:0% +cons I'm not sure if any one of them is + + + align:start position:0% +cons I'm not sure if any one of them is +sort of the right approach I think we + + align:start position:0% +sort of the right approach I think we + + + align:start position:0% +sort of the right approach I think we +often do favor using the sort of you + + align:start position:0% +often do favor using the sort of you + + + align:start position:0% +often do favor using the sort of you +know creaky old technology or the new + + align:start position:0% +know creaky old technology or the new + + + align:start position:0% +know creaky old technology or the new +technology right so epic has a built-in + + align:start position:0% +technology right so epic has a built-in + + + align:start position:0% +technology right so epic has a built-in +rule engine that laboratory system you + + align:start position:0% +rule engine that laboratory system you + + + align:start position:0% +rule engine that laboratory system you +talked about has a basic calculation + + align:start position:0% +talked about has a basic calculation + + + align:start position:0% +talked about has a basic calculation +engine with some significant limitations + + align:start position:0% +engine with some significant limitations + + + align:start position:0% +engine with some significant limitations +to it so where we can we often will try + + align:start position:0% +to it so where we can we often will try + + + align:start position:0% +to it so where we can we often will try +to build rules internally using these + + align:start position:0% +to build rules internally using these + + + align:start position:0% +to build rules internally using these +systems those tend to sort of have + + align:start position:0% +systems those tend to sort of have + + + align:start position:0% +systems those tend to sort of have +real-time availability of data the best + + align:start position:0% +real-time availability of data the best + + + align:start position:0% +real-time availability of data the best +ability to sort of push a little to be + + align:start position:0% +ability to sort of push a little to be + + + align:start position:0% +ability to sort of push a little to be +the person right in their workflow and + + align:start position:0% +the person right in their workflow and + + + align:start position:0% +the person right in their workflow and +make those alerts actionable in cases + + align:start position:0% +make those alerts actionable in cases + + + align:start position:0% +make those alerts actionable in cases +where we can't do that I like for + + align:start position:0% +where we can't do that I like for + + + align:start position:0% +where we can't do that I like for +example models it's too complex to + + align:start position:0% +example models it's too complex to + + + align:start position:0% +example models it's too complex to +execute in the system one thing that + + align:start position:0% +execute in the system one thing that + + + align:start position:0% +execute in the system one thing that +we've often done is sort of run that + + align:start position:0% +we've often done is sort of run that + + + align:start position:0% +we've often done is sort of run that +model against our data warehouse so we + + align:start position:0% +model against our data warehouse so we + + + align:start position:0% +model against our data warehouse so we +have a data warehouse that extracts the + + align:start position:0% +have a data warehouse that extracts the + + + align:start position:0% +have a data warehouse that extracts the +data from the electronic health record + + align:start position:0% +data from the electronic health record + + + align:start position:0% +data from the electronic health record +every night at midnight and so if we + + align:start position:0% +every night at midnight and so if we + + + align:start position:0% +every night at midnight and so if we +don't need real-time data it's possible + + align:start position:0% +don't need real-time data it's possible + + + align:start position:0% +don't need real-time data it's possible +to run the extract the data run a model + + align:start position:0% +to run the extract the data run a model + + + align:start position:0% +to run the extract the data run a model +and then actually write a risk score or + + align:start position:0% +and then actually write a risk score or + + + align:start position:0% +and then actually write a risk score or +a flag back into the patient's record + + align:start position:0% +a flag back into the patient's record + + + align:start position:0% +a flag back into the patient's record +that can then be shown to the clinician + + align:start position:0% +that can then be shown to the clinician + + + align:start position:0% +that can then be shown to the clinician +or used to drive an alert or something + + align:start position:0% +or used to drive an alert or something + + + align:start position:0% +or used to drive an alert or something +like that that works really well except + + align:start position:0% +like that that works really well except + + + align:start position:0% +like that that works really well except +that a lot of things that happen + + align:start position:0% +that a lot of things that happen + + + align:start position:0% +that a lot of things that happen +particularly an inpatient setting like + + align:start position:0% +particularly an inpatient setting like + + + align:start position:0% +particularly an inpatient setting like +predicting except this depend on + + align:start position:0% +predicting except this depend on + + + align:start position:0% +predicting except this depend on +real-time data anything that would mean + + align:start position:0% +real-time data anything that would mean + + + align:start position:0% +real-time data anything that would mean +right away and so we run into the + + align:start position:0% +right away and so we run into the + + + align:start position:0% +right away and so we run into the +challenge where that particular approach + + align:start position:0% +challenge where that particular approach + + + align:start position:0% +challenge where that particular approach +only works you know kind of on a 24-hour + + align:start position:0% +only works you know kind of on a 24-hour + + + align:start position:0% +only works you know kind of on a 24-hour +kind of retrospective basis we have also + + align:start position:0% +kind of retrospective basis we have also + + + align:start position:0% +kind of retrospective basis we have also +developed systems that depend on + + align:start position:0% +developed systems that depend on + + + align:start position:0% +developed systems that depend on +messages so there's this hl7 as + + align:start position:0% +messages so there's this hl7 as + + + align:start position:0% +messages so there's this hl7 as +standard format for exchanging data with + + align:start position:0% +standard format for exchanging data with + + + align:start position:0% +standard format for exchanging data with +the north priming health record various + + align:start position:0% +the north priming health record various + + + align:start position:0% +the north priming health record various +versions and profiles at hl7 but you can + + align:start position:0% +versions and profiles at hl7 but you can + + + align:start position:0% +versions and profiles at hl7 but you can +sort of set up an infrastructure that + + align:start position:0% +sort of set up an infrastructure that + + + align:start position:0% +sort of set up an infrastructure that +sits outside of the EHR and gets + + align:start position:0% +sits outside of the EHR and gets + + + align:start position:0% +sits outside of the EHR and gets +messages and real-time from the EHR and + + align:start position:0% +messages and real-time from the EHR and + + + align:start position:0% +messages and real-time from the EHR and +makes inferences and sort of sends + + align:start position:0% +makes inferences and sort of sends + + + align:start position:0% +makes inferences and sort of sends +messages back into the EHR increasingly + + align:start position:0% +messages back into the EHR increasingly + + + align:start position:0% +messages back into the EHR increasingly +EHRs also do support sort of kind of web + + align:start position:0% +EHRs also do support sort of kind of web + + + align:start position:0% +EHRs also do support sort of kind of web +service approaches right so that you can + + align:start position:0% +service approaches right so that you can + + + align:start position:0% +service approaches right so that you can +register a hook and say call my hook + + align:start position:0% +register a hook and say call my hook + + + align:start position:0% +register a hook and say call my hook +whenever this thing happens or you can + + align:start position:0% +whenever this thing happens or you can + + + align:start position:0% +whenever this thing happens or you can +pull the HR to get data out and use + + align:start position:0% +pull the HR to get data out and use + + + align:start position:0% +pull the HR to get data out and use +another web service to write data back + + align:start position:0% +another web service to write data back + + + align:start position:0% +another web service to write data back +in that's worked really well for us you + + align:start position:0% +in that's worked really well for us you + + + align:start position:0% +in that's worked really well for us you +can also sort of ask the EHR to sort of + + align:start position:0% +can also sort of ask the EHR to sort of + + + align:start position:0% +can also sort of ask the EHR to sort of +embed an app that you develop so people + + align:start position:0% +embed an app that you develop so people + + + align:start position:0% +embed an app that you develop so people +here may have heard or should hear at + + align:start position:0% +here may have heard or should hear at + + + align:start position:0% +here may have heard or should hear at +some point about smart on fire which is + + align:start position:0% +some point about smart on fire which is + + + align:start position:0% +some point about smart on fire which is +a open kind of API that allows you to + + align:start position:0% +a open kind of API that allows you to + + + align:start position:0% +a open kind of API that allows you to +sort of develop an application and embed + + align:start position:0% +sort of develop an application and embed + + + align:start position:0% +sort of develop an application and embed +that application into an electronic + + align:start position:0% +that application into an electronic + + + align:start position:0% +that application into an electronic +health record we've increasingly been + + align:start position:0% +health record we've increasingly been + + + align:start position:0% +health record we've increasingly been +building some of those those + + align:start position:0% +building some of those those + + + align:start position:0% +building some of those those +applications the downside right now the + + align:start position:0% +applications the downside right now the + + + align:start position:0% +applications the downside right now the +smart apps is that they're really good + + align:start position:0% +smart apps is that they're really good + + + align:start position:0% +smart apps is that they're really good +for sort of reading data out of the + + align:start position:0% +for sort of reading data out of the + + + align:start position:0% +for sort of reading data out of the +record and sort of visualizing or + + align:start position:0% +record and sort of visualizing or + + + align:start position:0% +record and sort of visualizing or +displaying it but they don't always have + + align:start position:0% +displaying it but they don't always have + + + align:start position:0% +displaying it but they don't always have +a lot of capability to sort of write + + align:start position:0% +a lot of capability to sort of write + + + align:start position:0% +a lot of capability to sort of write +data back into the record or take + + align:start position:0% +data back into the record or take + + + align:start position:0% +data back into the record or take +actions most of the HR vendors also have + + align:start position:0% +actions most of the HR vendors also have + + + align:start position:0% +actions most of the HR vendors also have +a proprietary approach like an app store + + align:start position:0% +a proprietary approach like an app store + + + align:start position:0% +a proprietary approach like an app store +so epic calls there's the app orchard + + align:start position:0% +so epic calls there's the app orchard + + + align:start position:0% +so epic calls there's the app orchard +and almost the EHRs have something + + align:start position:0% +and almost the EHRs have something + + + align:start position:0% +and almost the EHRs have something +similar where you can join a developer + + align:start position:0% +similar where you can join a developer + + + align:start position:0% +similar where you can join a developer +program and sort of build an application + + align:start position:0% +program and sort of build an application + + + align:start position:0% +program and sort of build an application +and those are often more full-featured + + align:start position:0% +and those are often more full-featured + + + align:start position:0% +and those are often more full-featured +they can may be proprietary so if you + + align:start position:0% +they can may be proprietary so if you + + + align:start position:0% +they can may be proprietary so if you +build one epic app you have to then + + align:start position:0% +build one epic app you have to then + + + align:start position:0% +build one epic app you have to then +build a Cerner happen in all scripts and + + align:start position:0% +build a Cerner happen in all scripts and + + + align:start position:0% +build a Cerner happen in all scripts and +eClinicalWorks after separately there + + align:start position:0% +eClinicalWorks after separately there + + + align:start position:0% +eClinicalWorks after separately there +are often heavy fees for joining those + + align:start position:0% +are often heavy fees for joining those + + + align:start position:0% +are often heavy fees for joining those +programs although the EHR vendors epic + + align:start position:0% +programs although the EHR vendors epic + + + align:start position:0% +programs although the EHR vendors epic +in particular have lowered their prices + + align:start position:0% +in particular have lowered their prices + + + align:start position:0% +in particular have lowered their prices +a lot and the federal government the + + align:start position:0% +a lot and the federal government the + + + align:start position:0% +a lot and the federal government the +Office of the National Coordinator for + + align:start position:0% +Office of the National Coordinator for + + + align:start position:0% +Office of the National Coordinator for +health IT just about a week and a half + + align:start position:0% +health IT just about a week and a half + + + align:start position:0% +health IT just about a week and a half +ago released some new regulations which + + align:start position:0% +ago released some new regulations which + + + align:start position:0% +ago released some new regulations which +really limit the rate at which vendors + + align:start position:0% +really limit the rate at which vendors + + + align:start position:0% +really limit the rate at which vendors +can charge application developers for + + align:start position:0% +can charge application developers for + + + align:start position:0% +can charge application developers for +API access basically to almost nothing + + align:start position:0% +API access basically to almost nothing + + + align:start position:0% +API access basically to almost nothing +except for kind of incremental + + align:start position:0% +except for kind of incremental + + + align:start position:0% +except for kind of incremental +computation costs our special support + + align:start position:0% +computation costs our special support + + + align:start position:0% +computation costs our special support +and so I think that may change + + align:start position:0% +and so I think that may change + + + align:start position:0% +and so I think that may change +everything now with that regulation has + + align:start position:0% +everything now with that regulation has + + + align:start position:0% +everything now with that regulation has +been promulgated so we'll see so + + align:start position:0% +been promulgated so we'll see so + + + align:start position:0% +been promulgated so we'll see so +contrary to my pessimistic beginning the + + align:start position:0% +contrary to my pessimistic beginning the + + + align:start position:0% +contrary to my pessimistic beginning the +this actually is the thing that makes me + + align:start position:0% +this actually is the thing that makes me + + + align:start position:0% +this actually is the thing that makes me +most optimistic + + align:start position:0% +most optimistic + + + align:start position:0% +most optimistic +that even five years ago if you looked + + align:start position:0% +that even five years ago if you looked + + + align:start position:0% +that even five years ago if you looked +at many of these systems they they + + align:start position:0% +at many of these systems they they + + + align:start position:0% +at many of these systems they they +essentially locked you out I remember in + + align:start position:0% +essentially locked you out I remember in + + + align:start position:0% +essentially locked you out I remember in +the early 2000s I was at the University + + align:start position:0% +the early 2000s I was at the University + + + align:start position:0% +the early 2000s I was at the University +of Pittsburgh where they had they had + + align:start position:0% +of Pittsburgh where they had they had + + + align:start position:0% +of Pittsburgh where they had they had +one of the first centers that was doing + + align:start position:0% +one of the first centers that was doing + + + align:start position:0% +one of the first centers that was doing +heart lung transplants and so there + + align:start position:0% +heart lung transplants and so there + + + align:start position:0% +heart lung transplants and so there +people had built a special application + + align:start position:0% +people had built a special application + + + align:start position:0% +people had built a special application +for supporting heart-lung transplant + + align:start position:0% +for supporting heart-lung transplant + + + align:start position:0% +for supporting heart-lung transplant +patients in their own home made + + align:start position:0% +patients in their own home made + + + align:start position:0% +patients in their own home made +electronic medical record system and + + align:start position:0% +electronic medical record system and + + + align:start position:0% +electronic medical record system and +then UPMC went to Cerner at the time and + + align:start position:0% +then UPMC went to Cerner at the time and + + + align:start position:0% +then UPMC went to Cerner at the time and +I remember I was at some meeting where + + align:start position:0% +I remember I was at some meeting where + + + align:start position:0% +I remember I was at some meeting where +the doctors who ran this heart-lung + + align:start position:0% +the doctors who ran this heart-lung + + + align:start position:0% +the doctors who ran this heart-lung +transplant unit were talking to the + + align:start position:0% +transplant unit were talking to the + + + align:start position:0% +transplant unit were talking to the +Cerner people and saying you know how + + align:start position:0% +Cerner people and saying you know how + + + align:start position:0% +Cerner people and saying you know how +could we get something to support our + + align:start position:0% +could we get something to support our + + + align:start position:0% +could we get something to support our +special needs for our patients and + + align:start position:0% +special needs for our patients and + + + align:start position:0% +special needs for our patients and +Cerner's answer was well you know + + align:start position:0% +Cerner's answer was well you know + + + align:start position:0% +Cerner's answer was well you know +commercially it doesn't make sense for + + align:start position:0% +commercially it doesn't make sense for + + + align:start position:0% +commercially it doesn't make sense for +us to do this because at the time there + + align:start position:0% +us to do this because at the time there + + + align:start position:0% +us to do this because at the time there +were like four hospitals in the country + + align:start position:0% +were like four hospitals in the country + + + align:start position:0% +were like four hospitals in the country +that did this and so it's not a big a + + align:start position:0% +that did this and so it's not a big a + + + align:start position:0% +that did this and so it's not a big a +big moneymaker and so their offer was + + align:start position:0% +big moneymaker and so their offer was + + + align:start position:0% +big moneymaker and so their offer was +while you pay us an extra three million + + align:start position:0% +while you pay us an extra three million + + + align:start position:0% +while you pay us an extra three million +dollars and within three years we will + + align:start position:0% +dollars and within three years we will + + + align:start position:0% +dollars and within three years we will +develop the appropriate software for you + + align:start position:0% +develop the appropriate software for you + + + align:start position:0% +develop the appropriate software for you +so that that's just crazy right I mean + + align:start position:0% +so that that's just crazy right I mean + + + align:start position:0% +so that that's just crazy right I mean +that's a totally untenable way of going + + align:start position:0% +that's a totally untenable way of going + + + align:start position:0% +that's a totally untenable way of going +about things and now that there are + + align:start position:0% +about things and now that there are + + + align:start position:0% +about things and now that there are +systemic ways for you either to embed + + align:start position:0% +systemic ways for you either to embed + + + align:start position:0% +systemic ways for you either to embed +your own code into one of these systems + + align:start position:0% +your own code into one of these systems + + + align:start position:0% +your own code into one of these systems +or at least to have a well documented + + align:start position:0% +or at least to have a well documented + + + align:start position:0% +or at least to have a well documented +reasonable way of feeding data out and + + align:start position:0% +reasonable way of feeding data out and + + + align:start position:0% +reasonable way of feeding data out and +then feeding results back into the + + align:start position:0% +then feeding results back into the + + + align:start position:0% +then feeding results back into the +system that makes it possible to do the + + align:start position:0% +system that makes it possible to do the + + + align:start position:0% +system that makes it possible to do the +special-purpose applications like this + + align:start position:0% +special-purpose applications like this + + + align:start position:0% +special-purpose applications like this +or experimental applications or all + + align:start position:0% +or experimental applications or all + + + align:start position:0% +or experimental applications or all +kinds of novel things so that's great + + align:start position:0% +kinds of novel things so that's great + + + align:start position:0% +kinds of novel things so that's great +that's what we're optimistic about but I + + align:start position:0% +that's what we're optimistic about but I + + + align:start position:0% +that's what we're optimistic about but I +think it's it's worth adding that + + align:start position:0% +think it's it's worth adding that + + + align:start position:0% +think it's it's worth adding that +there's sort of two barriers you have to + + align:start position:0% +there's sort of two barriers you have to + + + align:start position:0% +there's sort of two barriers you have to +get through right one is epic has to + + align:start position:0% +get through right one is epic has to + + + align:start position:0% +get through right one is epic has to +sort of let you into their app work + + align:start position:0% +sort of let you into their app work + + + align:start position:0% +sort of let you into their app work +shirt which is sort of the barrier that + + align:start position:0% +shirt which is sort of the barrier that + + + align:start position:0% +shirt which is sort of the barrier that +is increasingly lower and then you need + + align:start position:0% +is increasingly lower and then you need + + + align:start position:0% +is increasingly lower and then you need +to find a hospital or a healthcare + + align:start position:0% +to find a hospital or a healthcare + + + align:start position:0% +to find a hospital or a healthcare +provider that wants to use your app + + align:start position:0% +provider that wants to use your app + + + align:start position:0% +provider that wants to use your app +right you know so you kind of have to + + align:start position:0% +right you know so you kind of have to + + + align:start position:0% +right you know so you kind of have to +clear both of those + + align:start position:0% +clear both of those + + + align:start position:0% +clear both of those +I think it's increasingly possible you + + align:start position:0% +I think it's increasingly possible you + + + align:start position:0% +I think it's increasingly possible you +got smart people here at MIT or at the + + align:start position:0% +got smart people here at MIT or at the + + + align:start position:0% +got smart people here at MIT or at the +hospitals and we have in Boston sort of + + align:start position:0% +hospitals and we have in Boston sort of + + + align:start position:0% +hospitals and we have in Boston sort of +always sort of wanted to build these + + align:start position:0% +always sort of wanted to build these + + + align:start position:0% +always sort of wanted to build these +apps and I would say five years ago we + + align:start position:0% +apps and I would say five years ago we + + + align:start position:0% +apps and I would say five years ago we +would have told people sorry it's not + + align:start position:0% +would have told people sorry it's not + + + align:start position:0% +would have told people sorry it's not +possible and today we're usually to tell + + align:start position:0% +possible and today we're usually to tell + + + align:start position:0% +possible and today we're usually to tell +people that if there's clinical interest + + align:start position:0% +people that if there's clinical interest + + + align:start position:0% +people that if there's clinical interest +in that technical part will fall into + + align:start position:0% +in that technical part will fall into + + + align:start position:0% +in that technical part will fall into +place that's exciting for us yeah + + align:start position:0% + + + + align:start position:0% + +yeah there's a lot of different ways + + align:start position:0% +yeah there's a lot of different ways + + + align:start position:0% +yeah there's a lot of different ways +that we sort of share these applications + + align:start position:0% +that we sort of share these applications + + + align:start position:0% +that we sort of share these applications +right so a lot of us are researchers so + + align:start position:0% +right so a lot of us are researchers so + + + align:start position:0% +right so a lot of us are researchers so +we will you know released an open-source + + align:start position:0% +we will you know released an open-source + + + align:start position:0% +we will you know released an open-source +version of the application or you know + + align:start position:0% +version of the application or you know + + + align:start position:0% +version of the application or you know +write a paper and say this is available + + align:start position:0% +write a paper and say this is available + + + align:start position:0% +write a paper and say this is available +and what sort of shared with you the app + + align:start position:0% +and what sort of shared with you the app + + + align:start position:0% +and what sort of shared with you the app +orchard is particularly focused on + + align:start position:0% +orchard is particularly focused on + + + align:start position:0% +orchard is particularly focused on +applications that you want to sell so + + align:start position:0% +applications that you want to sell so + + + align:start position:0% +applications that you want to sell so +our hospital hasn't decided that we + + align:start position:0% +our hospital hasn't decided that we + + + align:start position:0% +our hospital hasn't decided that we +wanted to sell any applications we've + + align:start position:0% +wanted to sell any applications we've + + + align:start position:0% +wanted to sell any applications we've +given a lot of applications away epic + + align:start position:0% +given a lot of applications away epic + + + align:start position:0% +given a lot of applications away epic +also has something called the community + + align:start position:0% +also has something called the community + + + align:start position:0% +also has something called the community +library which is like the aperture but + + align:start position:0% +library which is like the aperture but + + + align:start position:0% +library which is like the aperture but +it's free instead of costing money and + + align:start position:0% +it's free instead of costing money and + + + align:start position:0% +it's free instead of costing money and +so we released a ton of stuff through + + align:start position:0% +so we released a ton of stuff through + + + align:start position:0% +so we released a ton of stuff through +the community library to the point that + + align:start position:0% +the community library to the point that + + + align:start position:0% +the community library to the point that +I was sort of poking out before one of + + align:start position:0% +I was sort of poking out before one of + + + align:start position:0% +I was sort of poking out before one of +the challenges is that if we build a + + align:start position:0% +the challenges is that if we build a + + + align:start position:0% +the challenges is that if we build a +smart on fire app we're able to sort of + + align:start position:0% +smart on fire app we're able to sort of + + + align:start position:0% +smart on fire app we're able to sort of +share that publicly we can post that on + + align:start position:0% +share that publicly we can post that on + + + align:start position:0% +share that publicly we can post that on +the web on github in any video you can + + align:start position:0% +the web on github in any video you can + + + align:start position:0% +the web on github in any video you can +use it epic has a position that they're + + align:start position:0% +use it epic has a position that they're + + + align:start position:0% +use it epic has a position that they're +api's are proprietary and they represent + + align:start position:0% +api's are proprietary and they represent + + + align:start position:0% +api's are proprietary and they represent +epics valuable intellectual property or + + align:start position:0% +epics valuable intellectual property or + + + align:start position:0% +epics valuable intellectual property or +trade secrets and so we're only allowed + + align:start position:0% +trade secrets and so we're only allowed + + + align:start position:0% +trade secrets and so we're only allowed +to share those apps through the the epic + + align:start position:0% +to share those apps through the the epic + + + align:start position:0% +to share those apps through the the epic +ecosystem and so we often now when we + + align:start position:0% +ecosystem and so we often now when we + + + align:start position:0% +ecosystem and so we often now when we +get a grant but most of my work is it is + + align:start position:0% +get a grant but most of my work is it is + + + align:start position:0% +get a grant but most of my work is it is +through grants we'll have an ethics I + + align:start position:0% +through grants we'll have an ethics I + + + align:start position:0% +through grants we'll have an ethics I +eat and we'll share that through the + + align:start position:0% +eat and we'll share that through the + + + align:start position:0% +eat and we'll share that through the +community why you bringing all of a + + align:start position:0% +community why you bringing all of a + + + align:start position:0% +community why you bringing all of a +Cerner site and share it through + + align:start position:0% +Cerner site and share it through + + + align:start position:0% +Cerner site and share it through +Cerner's equivalent but I think until + + align:start position:0% +Cerner's equivalent but I think until + + + align:start position:0% +Cerner's equivalent but I think until +the capability of the open API is like + + align:start position:0% +the capability of the open API is like + + + align:start position:0% +the capability of the open API is like +smart on fire reaches the same level as + + align:start position:0% +smart on fire reaches the same level as + + + align:start position:0% +smart on fire reaches the same level as +that proprietary api's we're still + + align:start position:0% +that proprietary api's we're still + + + align:start position:0% +that proprietary api's we're still +somewhat walked into having to build + + align:start position:0% +somewhat walked into having to build + + + align:start position:0% +somewhat walked into having to build +different versions and distribute three + + align:start position:0% +different versions and distribute three + + + align:start position:0% +different versions and distribute three +each HR under separate channel it's + + align:start position:0% +each HR under separate channel it's + + + align:start position:0% +each HR under separate channel it's +really really good question and so what + + align:start position:0% +really really good question and so what + + + align:start position:0% +really really good question and so what +what what's lacking in things like smart + + align:start position:0% +what what's lacking in things like smart + + + align:start position:0% +what what's lacking in things like smart +on fire that you get from the native + + align:start position:0% +on fire that you get from the native + + + align:start position:0% +on fire that you get from the native +interfaces so I mean it's very + + align:start position:0% +interfaces so I mean it's very + + + align:start position:0% +interfaces so I mean it's very +situational right so so for example + + align:start position:0% +situational right so so for example + + + align:start position:0% +situational right so so for example +certain you know and some EHR + + align:start position:0% +certain you know and some EHR + + + align:start position:0% +certain you know and some EHR +implementations this Marmon fire will + + align:start position:0% +implementations this Marmon fire will + + + align:start position:0% +implementations this Marmon fire will +give you lists of the patient's current + + align:start position:0% +give you lists of the patient's current + + + align:start position:0% +give you lists of the patient's current +medications but may not give you + + align:start position:0% +medications but may not give you + + + align:start position:0% +medications but may not give you +historical medications or will tell you + + align:start position:0% +historical medications or will tell you + + + align:start position:0% +historical medications or will tell you +that the medicine is ordered but it + + align:start position:0% +that the medicine is ordered but it + + + align:start position:0% +that the medicine is ordered but it +won't tell you whether it's been + + align:start position:0% +won't tell you whether it's been + + + align:start position:0% +won't tell you whether it's been +administered so one half the battle is + + align:start position:0% +administered so one half the battle is + + + align:start position:0% +administered so one half the battle is +less complete data the other one is that + + align:start position:0% +less complete data the other one is that + + + align:start position:0% +less complete data the other one is that +the most EHRs are not implementing at + + align:start position:0% +the most EHRs are not implementing at + + + align:start position:0% +the most EHRs are not implementing at +this point the sort of right back + + align:start position:0% +this point the sort of right back + + + align:start position:0% +this point the sort of right back +capabilities or the actionable + + align:start position:0% +capabilities or the actionable + + + align:start position:0% +capabilities or the actionable +capabilities that smart on fire is sort + + align:start position:0% +capabilities that smart on fire is sort + + + align:start position:0% +capabilities that smart on fire is sort +of working on and it released some + + align:start position:0% +of working on and it released some + + + align:start position:0% +of working on and it released some +standards for us so if we want to build + + align:start position:0% +standards for us so if we want to build + + + align:start position:0% +standards for us so if we want to build +an application sort of shows how a page + + align:start position:0% +an application sort of shows how a page + + + align:start position:0% +an application sort of shows how a page +fits on a growth curve that's fine if we + + align:start position:0% +fits on a growth curve that's fine if we + + + align:start position:0% +fits on a growth curve that's fine if we +went balloon applications suggest + + align:start position:0% +went balloon applications suggest + + + align:start position:0% +went balloon applications suggest +ordering medicines that can be really + + align:start position:0% +ordering medicines that can be really + + + align:start position:0% +ordering medicines that can be really +challenging where is the internal API so + + align:start position:0% +challenging where is the internal API so + + + align:start position:0% +challenging where is the internal API so +the vendors provide typically have both + + align:start position:0% +the vendors provide typically have both + + + align:start position:0% +the vendors provide typically have both +read and write capabilities do the + + align:start position:0% +read and write capabilities do the + + + align:start position:0% +read and write capabilities do the +vendors worry about I guess two related + + align:start position:0% +vendors worry about I guess two related + + + align:start position:0% +vendors worry about I guess two related +things one is sort of cognitive overload + + align:start position:0% +things one is sort of cognitive overload + + + align:start position:0% +things one is sort of cognitive overload +because if you build a thousand smart on + + align:start position:0% +because if you build a thousand smart on + + + align:start position:0% +because if you build a thousand smart on +fire apps and they all start firing for + + align:start position:0% +fire apps and they all start firing for + + + align:start position:0% +fire apps and they all start firing for +these impatience you're gonna be back in + + align:start position:0% +these impatience you're gonna be back in + + + align:start position:0% +these impatience you're gonna be back in +the same situation of over alerting and + + align:start position:0% +the same situation of over alerting and + + + align:start position:0% +the same situation of over alerting and +the other question is is are they + + align:start position:0% +the other question is is are they + + + align:start position:0% +the other question is is are they +worried about liability since if you're + + align:start position:0% +worried about liability since if you're + + + align:start position:0% +worried about liability since if you're +using their system to display + + align:start position:0% +using their system to display + + + align:start position:0% +using their system to display +recommendations and those + + align:start position:0% +recommendations and those + + + align:start position:0% +recommendations and those +recommendations turn out to be wrong and + + align:start position:0% +recommendations turn out to be wrong and + + + align:start position:0% +recommendations turn out to be wrong and +harmful impatient then somebody will + + align:start position:0% +harmful impatient then somebody will + + + align:start position:0% +harmful impatient then somebody will +reach out to them legally because they + + align:start position:0% +reach out to them legally because they + + + align:start position:0% +reach out to them legally because they +have a lot of money absolutely they're + + align:start position:0% +have a lot of money absolutely they're + + + align:start position:0% +have a lot of money absolutely they're +worried about both of those related + + align:start position:0% +worried about both of those related + + + align:start position:0% +worried about both of those related +particularly to the second one they're + + align:start position:0% +particularly to the second one they're + + + align:start position:0% +particularly to the second one they're +also worried about sort of you know + + align:start position:0% +also worried about sort of you know + + + align:start position:0% +also worried about sort of you know +corruption or integrity of the data + + align:start position:0% +corruption or integrity of the data + + + align:start position:0% +corruption or integrity of the data +right so somehow if I can write a + + align:start position:0% +right so somehow if I can write a + + + align:start position:0% +right so somehow if I can write a +medication order directly to the + + align:start position:0% +medication order directly to the + + + align:start position:0% +medication order directly to the +database and it may bypass certain + + align:start position:0% +database and it may bypass certain + + + align:start position:0% +database and it may bypass certain +checks that would be done normally and + + align:start position:0% +checks that would be done normally and + + + align:start position:0% +checks that would be done normally and +and I can potentially enter a wrong or + + align:start position:0% +and I can potentially enter a wrong or + + + align:start position:0% +and I can potentially enter a wrong or +dangerous order the other thing that + + align:start position:0% +dangerous order the other thing that + + + align:start position:0% +dangerous order the other thing that +we're increasingly hearing is sort of + + align:start position:0% +we're increasingly hearing is sort of + + + align:start position:0% +we're increasingly hearing is sort of +concerns about kind of protection of + + align:start position:0% +concerns about kind of protection of + + + align:start position:0% +concerns about kind of protection of +data sort of Cambridge analytic a style + + align:start position:0% +data sort of Cambridge analytic a style + + + align:start position:0% +data sort of Cambridge analytic a style +worries right so if I as a epic patient + + align:start position:0% +worries right so if I as a epic patient + + + align:start position:0% +worries right so if I as a epic patient +authorize you know the you know words + + align:start position:0% +authorize you know the you know words + + + align:start position:0% +authorize you know the you know words +with friends app to like see my medical + + align:start position:0% +with friends app to like see my medical + + + align:start position:0% +with friends app to like see my medical +record and then they post that on the + + align:start position:0% +record and then they post that on the + + + align:start position:0% +record and then they post that on the +web or sort of monetize it in some sort + + align:start position:0% +web or sort of monetize it in some sort + + + align:start position:0% +web or sort of monetize it in some sort +of tricky way what liability if any does + + align:start position:0% +of tricky way what liability if any does + + + align:start position:0% +of tricky way what liability if any does +my health care provider organization or + + align:start position:0% +my health care provider organization or + + + align:start position:0% +my health care provider organization or +my the HR vendor have for that and and + + align:start position:0% +my the HR vendor have for that and and + + + align:start position:0% +my the HR vendor have for that and and +the new regulations are extremely strict + + align:start position:0% +the new regulations are extremely strict + + + align:start position:0% +the new regulations are extremely strict +right they say that if a patient asks + + align:start position:0% +right they say that if a patient asks + + + align:start position:0% +right they say that if a patient asks +you to and authorizes an act to access + + align:start position:0% +you to and authorizes an act to access + + + align:start position:0% +you to and authorizes an act to access +their record you may not block that + + align:start position:0% +their record you may not block that + + + align:start position:0% +their record you may not block that +access even if you could say that I have + + align:start position:0% +access even if you could say that I have + + + align:start position:0% +access even if you could say that I have +to be a bad actor so that's I think an + + align:start position:0% +to be a bad actor so that's I think an + + + align:start position:0% +to be a bad actor so that's I think an +area of liability that is just beginning + + align:start position:0% +area of liability that is just beginning + + + align:start position:0% +area of liability that is just beginning +to be sorted out and it is I think some + + align:start position:0% +to be sorted out and it is I think some + + + align:start position:0% +to be sorted out and it is I think some +cause for concern but at the same time + + align:start position:0% +cause for concern but at the same time + + + align:start position:0% +cause for concern but at the same time +you could imagine universe where I think + + align:start position:0% +you could imagine universe where I think + + + align:start position:0% +you could imagine universe where I think +there are conservative healthcare + + align:start position:0% +there are conservative healthcare + + + align:start position:0% +there are conservative healthcare +organizations they would choose to never + + align:start position:0% +organizations they would choose to never + + + align:start position:0% +organizations they would choose to never +authorize any application to avoid risk + + align:start position:0% +authorize any application to avoid risk + + + align:start position:0% +authorize any application to avoid risk +so how you balance that is it's not yet + + align:start position:0% +so how you balance that is it's not yet + + + align:start position:0% +so how you balance that is it's not yet +solved well or and to avoid leakage so I + + align:start position:0% +solved well or and to avoid leakage so I + + + align:start position:0% +solved well or and to avoid leakage so I +remember years ago there was a lot of + + align:start position:0% +remember years ago there was a lot of + + + align:start position:0% +remember years ago there was a lot of +reluctance even among Boston area + + align:start position:0% +reluctance even among Boston area + + + align:start position:0% +reluctance even among Boston area +hospitals to share data because they + + align:start position:0% +hospitals to share data because they + + + align:start position:0% +hospitals to share data because they +were worried that another hospital could + + align:start position:0% +were worried that another hospital could + + + align:start position:0% +were worried that another hospital could +cherry-pick their most lucrative + + align:start position:0% +cherry-pick their most lucrative + + + align:start position:0% +cherry-pick their most lucrative +patients by figuring out something about + + align:start position:0% +patients by figuring out something about + + + align:start position:0% +patients by figuring out something about +them so I'm sure that that hasn't gone + + align:start position:0% +them so I'm sure that that hasn't gone + + + align:start position:0% +them so I'm sure that that hasn't gone +away as a concern yeah okay we're gonna + + align:start position:0% +away as a concern yeah okay we're gonna + + + align:start position:0% +away as a concern yeah okay we're gonna +try to remember to repeat the questions + + align:start position:0% +try to remember to repeat the questions + + + align:start position:0% +try to remember to repeat the questions +you're asking okay because of the + + align:start position:0% +you're asking okay because of the + + + align:start position:0% +you're asking okay because of the +recording yeah so the question is how + + align:start position:0% +recording yeah so the question is how + + + align:start position:0% +recording yeah so the question is how +does a third party vendor deploy an + + align:start position:0% +does a third party vendor deploy an + + + align:start position:0% +does a third party vendor deploy an +application or a machine learning model + + align:start position:0% +application or a machine learning model + + + align:start position:0% +application or a machine learning model +or something like that and so with epic + + align:start position:0% +or something like that and so with epic + + + align:start position:0% +or something like that and so with epic +there's always a relationship between + + align:start position:0% +there's always a relationship between + + + align:start position:0% +there's always a relationship between +the vendor of the application and the + + align:start position:0% +the vendor of the application and the + + + align:start position:0% +the vendor of the application and the +healthcare provider organization and so + + align:start position:0% +healthcare provider organization and so + + + align:start position:0% +healthcare provider organization and so +we could work together directly so if + + align:start position:0% +we could work together directly so if + + + align:start position:0% +we could work together directly so if +you had an app that the Brigham wanted + + align:start position:0% +you had an app that the Brigham wanted + + + align:start position:0% +you had an app that the Brigham wanted +to use you could share that app with us + + align:start position:0% +to use you could share that app with us + + + align:start position:0% +to use you could share that app with us +in a number of ways so epic supports + + align:start position:0% +in a number of ways so epic supports + + + align:start position:0% +in a number of ways so epic supports +this this thing called predictive + + align:start position:0% +this this thing called predictive + + + align:start position:0% +this this thing called predictive +modeling markup language or PMML so if + + align:start position:0% +modeling markup language or PMML so if + + + align:start position:0% +modeling markup language or PMML so if +you train a model you can export a P in + + align:start position:0% +you train a model you can export a P in + + + align:start position:0% +you train a model you can export a P in +the male model I can import it into epic + + align:start position:0% +the male model I can import it into epic + + + align:start position:0% +the male model I can import it into epic +and and run it natively or you can + + align:start position:0% +and and run it natively or you can + + + align:start position:0% +and and run it natively or you can +produce a web service that I call out to + + align:start position:0% +produce a web service that I call out to + + + align:start position:0% +produce a web service that I call out to +and sort of it gives me an answer we + + align:start position:0% +and sort of it gives me an answer we + + + align:start position:0% +and sort of it gives me an answer we +could work together directly however + + align:start position:0% +could work together directly however + + + align:start position:0% +could work together directly however +there are some limitations and what I'm + + align:start position:0% +there are some limitations and what I'm + + + align:start position:0% +there are some limitations and what I'm +allowed to sort of tell you or share + + align:start position:0% +allowed to sort of tell you or share + + + align:start position:0% +allowed to sort of tell you or share +with you about epics data model and epic + + align:start position:0% +with you about epics data model and epic + + + align:start position:0% +with you about epics data model and epic +whatever seems to be their their + + align:start position:0% +whatever seems to be their their + + + align:start position:0% +whatever seems to be their their +intellectual property and so it is + + align:start position:0% +intellectual property and so it is + + + align:start position:0% +intellectual property and so it is +facilitated by you joining this program + + align:start position:0% +facilitated by you joining this program + + + align:start position:0% +facilitated by you joining this program +because if you join this program you get + + align:start position:0% +because if you join this program you get + + + align:start position:0% +because if you join this program you get +access to documentation you would + + align:start position:0% +access to documentation you would + + + align:start position:0% +access to documentation you would +otherwise not have access to you may get + + align:start position:0% +otherwise not have access to you may get + + + align:start position:0% +otherwise not have access to you may get +access to a test harness or a test + + align:start position:0% +access to a test harness or a test + + + align:start position:0% +access to a test harness or a test +system that lets you sort of validate + + align:start position:0% +system that lets you sort of validate + + + align:start position:0% +system that lets you sort of validate +your work however people who join the + + align:start position:0% +your work however people who join the + + + align:start position:0% +your work however people who join the +program often think that means that I + + align:start position:0% +program often think that means that I + + + align:start position:0% +program often think that means that I +can then just run my app at every + + align:start position:0% +can then just run my app at every + + + align:start position:0% +can then just run my app at every +customer right but with epic in + + align:start position:0% +customer right but with epic in + + + align:start position:0% +customer right but with epic in +particular you have to then make a deal + + align:start position:0% +particular you have to then make a deal + + + align:start position:0% +particular you have to then make a deal +with me to use it at the program and + + align:start position:0% +with me to use it at the program and + + + align:start position:0% +with me to use it at the program and +make a deal with you know my colleague + + align:start position:0% +make a deal with you know my colleague + + + align:start position:0% +make a deal with you know my colleague +to use it at Stanford other EHR vendors + + align:start position:0% +to use it at Stanford other EHR vendors + + + align:start position:0% +to use it at Stanford other EHR vendors +have developed a more sort of + + align:start position:0% +have developed a more sort of + + + align:start position:0% +have developed a more sort of +centralized model where you can actually + + align:start position:0% +centralized model where you can actually + + + align:start position:0% +centralized model where you can actually +sort of release it in + + align:start position:0% +sort of release it in + + + align:start position:0% +sort of release it in +salad and I can pay for it directly + + align:start position:0% +salad and I can pay for it directly + + + align:start position:0% +salad and I can pay for it directly +through through the app store and + + align:start position:0% +through through the app store and + + + align:start position:0% +through through the app store and +integrate it I think that last mile + + align:start position:0% +integrate it I think that last mile + + + align:start position:0% +integrate it I think that last mile +piece hasn't really been standardized + + align:start position:0% +piece hasn't really been standardized + + + align:start position:0% +piece hasn't really been standardized +yet yeah we just want to not stop us + + align:start position:0% +yet yeah we just want to not stop us + + + align:start position:0% +yet yeah we just want to not stop us +from doing that the only real + + align:start position:0% +from doing that the only real + + + align:start position:0% +from doing that the only real +restriction is that epic would limit my + + align:start position:0% +restriction is that epic would limit my + + + align:start position:0% +restriction is that epic would limit my +ability to tell you stuff about epics + + align:start position:0% +ability to tell you stuff about epics + + + align:start position:0% +ability to tell you stuff about epics +guts and so you would need a relatively + + align:start position:0% +guts and so you would need a relatively + + + align:start position:0% +guts and so you would need a relatively +sophisticated healthcare provider + + align:start position:0% +sophisticated healthcare provider + + + align:start position:0% +sophisticated healthcare provider +organization who could map between some + + align:start position:0% +organization who could map between some + + + align:start position:0% +organization who could map between some +sort of kind of platonic date of + + align:start position:0% +sort of kind of platonic date of + + + align:start position:0% +sort of kind of platonic date of +clinical data model and epics internal + + align:start position:0% +clinical data model and epics internal + + + align:start position:0% +clinical data model and epics internal +data model but if you had that you could + + align:start position:0% +data model but if you had that you could + + + align:start position:0% +data model but if you had that you could +any minute the freedom we have this AI + + align:start position:0% +any minute the freedom we have this AI + + + align:start position:0% +any minute the freedom we have this AI +hub innovation program and we're + + align:start position:0% +hub innovation program and we're + + + align:start position:0% +hub innovation program and we're +probably working with 50 to 100 startups + + align:start position:0% +probably working with 50 to 100 startups + + + align:start position:0% +probably working with 50 to 100 startups +of doing work like that some of whom are + + align:start position:0% +of doing work like that some of whom are + + + align:start position:0% +of doing work like that some of whom are +members of the epic aperture and some + + align:start position:0% +members of the epic aperture and some + + + align:start position:0% +members of the epic aperture and some +who choose not to University in the epic + + align:start position:0% +who choose not to University in the epic + + + align:start position:0% +who choose not to University in the epic +aperture it's we're saying that joining + + align:start position:0% +aperture it's we're saying that joining + + + align:start position:0% +aperture it's we're saying that joining +the aperture during these programs + + align:start position:0% +the aperture during these programs + + + align:start position:0% +the aperture during these programs +entails revenue sharing with that + + align:start position:0% +entails revenue sharing with that + + + align:start position:0% +entails revenue sharing with that +backhand and some complexity that may go + + align:start position:0% +backhand and some complexity that may go + + + align:start position:0% +backhand and some complexity that may go +way down with these new regulations but + + align:start position:0% +way down with these new regulations but + + + align:start position:0% +way down with these new regulations but +right now some organizations have chosen + + align:start position:0% +right now some organizations have chosen + + + align:start position:0% +right now some organizations have chosen +not to not to partner with the vendors + + align:start position:0% +not to not to partner with the vendors + + + align:start position:0% +not to not to partner with the vendors +more directly without their fight + + align:start position:0% +more directly without their fight + + + align:start position:0% +more directly without their fight +organization so on the quality side of + + align:start position:0% +organization so on the quality side of + + + align:start position:0% +organization so on the quality side of +that question if you do develop an + + align:start position:0% +that question if you do develop an + + + align:start position:0% +that question if you do develop an +application and field it at the Brigham + + align:start position:0% +application and field it at the Brigham + + + align:start position:0% +application and field it at the Brigham +will that will Stanford be interested in + + align:start position:0% +will that will Stanford be interested in + + + align:start position:0% +will that will Stanford be interested in +in taking it or are they going to be + + align:start position:0% +in taking it or are they going to be + + + align:start position:0% +in taking it or are they going to be +concerned about the fact that somehow + + align:start position:0% +concerned about the fact that somehow + + + align:start position:0% +concerned about the fact that somehow +you fit it to the patient population in + + align:start position:0% +you fit it to the patient population in + + + align:start position:0% +you fit it to the patient population in +Boston and it won't be appropriate to + + align:start position:0% +Boston and it won't be appropriate to + + + align:start position:0% +Boston and it won't be appropriate to +their data yeah I think that's a + + align:start position:0% +their data yeah I think that's a + + + align:start position:0% +their data yeah I think that's a +fundamental question right as to what + + align:start position:0% +fundamental question right as to what + + + align:start position:0% +fundamental question right as to what +extent do these models generalize right + + align:start position:0% +extent do these models generalize right + + + align:start position:0% +extent do these models generalize right +can you train a model at one place to + + align:start position:0% +can you train a model at one place to + + + align:start position:0% +can you train a model at one place to +transfer it to it to another place we + + align:start position:0% +transfer it to it to another place we + + + align:start position:0% +transfer it to it to another place we +generally seem that many of them + + align:start position:0% +generally seem that many of them + + + align:start position:0% +generally seem that many of them +transfer pretty well right so if they + + align:start position:0% +transfer pretty well right so if they + + + align:start position:0% +transfer pretty well right so if they +really have more to do with kind of core + + align:start position:0% +really have more to do with kind of core + + + align:start position:0% +really have more to do with kind of core +human physiology that can be pretty + + align:start position:0% +human physiology that can be pretty + + + align:start position:0% +human physiology that can be pretty +similar between organizations if they're + + align:start position:0% +similar between organizations if they're + + + align:start position:0% +similar between organizations if they're +sort of really bound up in a particular + + align:start position:0% +sort of really bound up in a particular + + + align:start position:0% +sort of really bound up in a particular +workflow right they do you know they + + align:start position:0% +workflow right they do you know they + + + align:start position:0% +workflow right they do you know they +assume that you're doing this task this + + align:start position:0% +assume that you're doing this task this + + + align:start position:0% +assume that you're doing this task this +task this task in this order they tend + + align:start position:0% +task this task in this order they tend + + + align:start position:0% +task this task in this order they tend +to transfer really very poorly so I + + align:start position:0% +to transfer really very poorly so I + + + align:start position:0% +to transfer really very poorly so I +would say that our general approach has + + align:start position:0% +would say that our general approach has + + + align:start position:0% +would say that our general approach has +been to take a model that somebody has + + align:start position:0% +been to take a model that somebody has + + + align:start position:0% +been to take a model that somebody has +sort of run at retrospectively on our + + align:start position:0% +sort of run at retrospectively on our + + + align:start position:0% +sort of run at retrospectively on our +data warehouse and see if it's accurate + + align:start position:0% +data warehouse and see if it's accurate + + + align:start position:0% +data warehouse and see if it's accurate +and if it is we might go forward with it + + align:start position:0% +and if it is we might go forward with it + + + align:start position:0% +and if it is we might go forward with it +if it's not we would try to retrain it + + align:start position:0% +if it's not we would try to retrain it + + + align:start position:0% +if it's not we would try to retrain it +on our data and then see how much + + align:start position:0% +on our data and then see how much + + + align:start position:0% +on our data and then see how much +improvement we get by retraining it and + + align:start position:0% +improvement we get by retraining it and + + + align:start position:0% +improvement we get by retraining it and +so have you in fact imported such + + align:start position:0% +so have you in fact imported such + + + align:start position:0% +so have you in fact imported such +model yeah yeah we provides five or six + + align:start position:0% +model yeah yeah we provides five or six + + + align:start position:0% +model yeah yeah we provides five or six +models we just started using some of + + align:start position:0% +models we just started using some of + + + align:start position:0% +models we just started using some of +them at the Brigham are just kind of + + align:start position:0% +them at the Brigham are just kind of + + + align:start position:0% +them at the Brigham are just kind of +signed a license to begin using them and + + align:start position:0% +signed a license to begin using them and + + + align:start position:0% +signed a license to begin using them and +I think in our experiences that yeah + + align:start position:0% +I think in our experiences that yeah + + + align:start position:0% +I think in our experiences that yeah +absolutely so the question is we get a + + align:start position:0% +absolutely so the question is we get a + + + align:start position:0% +absolutely so the question is we get a +risks or we deploy new risk or it says + + align:start position:0% +risks or we deploy new risk or it says + + + align:start position:0% +risks or we deploy new risk or it says +patients a fall Langer patients who've + + align:start position:0% +patients a fall Langer patients who've + + + align:start position:0% +patients a fall Langer patients who've +had them sepsis or something like that + + align:start position:0% +had them sepsis or something like that + + + align:start position:0% +had them sepsis or something like that +you know we tend to do several levels of + + align:start position:0% +you know we tend to do several levels of + + + align:start position:0% +you know we tend to do several levels of +evaluation right so so the first level + + align:start position:0% +evaluation right so so the first level + + + align:start position:0% +evaluation right so so the first level +is when we show the score what do people + + align:start position:0% +is when we show the score what do people + + + align:start position:0% +is when we show the score what do people +do right if we typically we don't just + + align:start position:0% +do right if we typically we don't just + + + align:start position:0% +do right if we typically we don't just +show a score we make a recommendation we + + align:start position:0% +show a score we make a recommendation we + + + align:start position:0% +show a score we make a recommendation we +say based on the score we think you + + align:start position:0% +say based on the score we think you + + + align:start position:0% +say based on the score we think you +should order a lactate to see if the + + align:start position:0% +should order a lactate to see if the + + + align:start position:0% +should order a lactate to see if the +patient is at risk of having sepsis + + align:start position:0% +patient is at risk of having sepsis + + + align:start position:0% +patient is at risk of having sepsis +first we like to see if people do what + + align:start position:0% +first we like to see if people do what + + + align:start position:0% +first we like to see if people do what +we say right so we think it's a good + + align:start position:0% +we say right so we think it's a good + + + align:start position:0% +we say right so we think it's a good +sign if people sort of follow the + + align:start position:0% +sign if people sort of follow the + + + align:start position:0% +sign if people sort of follow the +suggestions but ultimately you know we + + align:start position:0% +suggestions but ultimately you know we + + + align:start position:0% +suggestions but ultimately you know we +view ourselves as sort of clinical trial + + align:start position:0% +view ourselves as sort of clinical trial + + + align:start position:0% +view ourselves as sort of clinical trial +lists right so we deploy this model with + + align:start position:0% +lists right so we deploy this model with + + + align:start position:0% +lists right so we deploy this model with +an intent to move something right to + + align:start position:0% +an intent to move something right to + + + align:start position:0% +an intent to move something right to +reduce the rate of sepsis or to reduce + + align:start position:0% +reduce the rate of sepsis or to reduce + + + align:start position:0% +reduce the rate of sepsis or to reduce +the rate of mortality in sepsis and said + + align:start position:0% +the rate of mortality in sepsis and said + + + align:start position:0% +the rate of mortality in sepsis and said +we would try to sort of measure it if + + align:start position:0% +we would try to sort of measure it if + + + align:start position:0% +we would try to sort of measure it if +nothing else do it before and after City + + align:start position:0% +nothing else do it before and after City + + + align:start position:0% +nothing else do it before and after City +right measure the rates before implement + + align:start position:0% +right measure the rates before implement + + + align:start position:0% +right measure the rates before implement +this intervention and measure the rates + + align:start position:0% +this intervention and measure the rates + + + align:start position:0% +this intervention and measure the rates +after in cases where we're sort of less + + align:start position:0% +after in cases where we're sort of less + + + align:start position:0% +after in cases where we're sort of less +sure we really care about the results + + align:start position:0% +sure we really care about the results + + + align:start position:0% +sure we really care about the results +we'll even do a randomized trial right + + align:start position:0% +we'll even do a randomized trial right + + + align:start position:0% +we'll even do a randomized trial right +so look if half of the units will get a + + align:start position:0% +so look if half of the units will get a + + + align:start position:0% +so look if half of the units will get a +the alert half the units won't get the + + align:start position:0% +the alert half the units won't get the + + + align:start position:0% +the alert half the units won't get the +alert unless you compare the effect on a + + align:start position:0% +alert unless you compare the effect on a + + + align:start position:0% +alert unless you compare the effect on a +clinical outcome and see what that what + + align:start position:0% +clinical outcome and see what that what + + + align:start position:0% +clinical outcome and see what that what +the difference is it our opinion unless + + align:start position:0% +the difference is it our opinion unless + + + align:start position:0% +the difference is it our opinion unless +we can show and sort of an effect on + + align:start position:0% +we can show and sort of an effect on + + + align:start position:0% +we can show and sort of an effect on +these clinical measures we shouldn't be + + align:start position:0% +these clinical measures we shouldn't be + + + align:start position:0% +these clinical measures we shouldn't be +bothering people right you know Pete + + align:start position:0% +bothering people right you know Pete + + + align:start position:0% +bothering people right you know Pete +made this point that you know what's the + + align:start position:0% +made this point that you know what's the + + + align:start position:0% +made this point that you know what's the +purpose of have that you know if we have + + align:start position:0% +purpose of have that you know if we have + + + align:start position:0% +purpose of have that you know if we have +a thousand alerts everyone will be + + align:start position:0% +a thousand alerts everyone will be + + + align:start position:0% +a thousand alerts everyone will be +overwhelmed so we should only keep + + align:start position:0% +overwhelmed so we should only keep + + + align:start position:0% +overwhelmed so we should only keep +alerts on it for each other they're + + align:start position:0% +alerts on it for each other they're + + + align:start position:0% +alerts on it for each other they're +making a real clinical difference + + align:start position:0% + + + + align:start position:0% + +checks are there papers of like some of + + align:start position:0% +checks are there papers of like some of + + + align:start position:0% +checks are there papers of like some of +these deployments uh it sorry tart + + align:start position:0% +these deployments uh it sorry tart + + + align:start position:0% +these deployments uh it sorry tart +intend to publish everything right and I + + align:start position:0% +intend to publish everything right and I + + + align:start position:0% +intend to publish everything right and I +think we're behind but I'd say you don't + + align:start position:0% +think we're behind but I'd say you don't + + + align:start position:0% +think we're behind but I'd say you don't +we publish everything we off we have + + align:start position:0% +we publish everything we off we have + + + align:start position:0% +we publish everything we off we have +some things that we finish that we + + align:start position:0% +some things that we finish that we + + + align:start position:0% +some things that we finish that we +haven't published yet they're sort of + + align:start position:0% +haven't published yet they're sort of + + + align:start position:0% +haven't published yet they're sort of +the next thing to sort of come out yeah + + align:start position:0% +the next thing to sort of come out yeah + + + align:start position:0% +the next thing to sort of come out yeah +absolutely + + align:start position:0% +absolutely + + + align:start position:0% +absolutely +oh yeah so the question is do we ever + + align:start position:0% +oh yeah so the question is do we ever + + + align:start position:0% +oh yeah so the question is do we ever +check to see how often the model + + align:start position:0% +check to see how often the model + + + align:start position:0% +check to see how often the model +recommendation matches what the doctor + + align:start position:0% +recommendation matches what the doctor + + + align:start position:0% +recommendation matches what the doctor +does and so there's sort of two ways we + + align:start position:0% +does and so there's sort of two ways we + + + align:start position:0% +does and so there's sort of two ways we +do that we'll often retrospectively test + + align:start position:0% +do that we'll often retrospectively test + + + align:start position:0% +do that we'll often retrospectively test +the model back and so I think peach + + align:start position:0% +the model back and so I think peach + + + align:start position:0% +the model back and so I think peach +aired a paper from Cerner where they + + align:start position:0% +aired a paper from Cerner where they + + + align:start position:0% +aired a paper from Cerner where they +looked at these sort of suggestions that + + align:start position:0% +looked at these sort of suggestions that + + + align:start position:0% +looked at these sort of suggestions that +they made to order the lactates or to do + + align:start position:0% +they made to order the lactates or to do + + + align:start position:0% +they made to order the lactates or to do +other sort of sepsis works definitely + + align:start position:0% +other sort of sepsis works definitely + + + align:start position:0% +other sort of sepsis works definitely +look to see whether the recommendations + + align:start position:0% +look to see whether the recommendations + + + align:start position:0% +look to see whether the recommendations +that they made matched what the doctors + + align:start position:0% +that they made matched what the doctors + + + align:start position:0% +that they made matched what the doctors +had actually done and they they showed + + align:start position:0% +had actually done and they they showed + + + align:start position:0% +had actually done and they they showed +that they in many cases did so that + + align:start position:0% +that they in many cases did so that + + + align:start position:0% +that they in many cases did so that +would be the first thing that we do is + + align:start position:0% +would be the first thing that we do is + + + align:start position:0% +would be the first thing that we do is +before we even turn the model on will + + align:start position:0% +before we even turn the model on will + + + align:start position:0% +before we even turn the model on will +run it in sort of silent mode and see if + + align:start position:0% +run it in sort of silent mode and see if + + + align:start position:0% +run it in sort of silent mode and see if +the doctor does what we suggest now the + + align:start position:0% +the doctor does what we suggest now the + + + align:start position:0% +the doctor does what we suggest now the +doctor is not a perfect supervision + + align:start position:0% +doctor is not a perfect supervision + + + align:start position:0% +doctor is not a perfect supervision +right because the doctor may neglect to + + align:start position:0% +right because the doctor may neglect to + + + align:start position:0% +right because the doctor may neglect to +do something that would be good to do so + + align:start position:0% +do something that would be good to do so + + + align:start position:0% +do something that would be good to do so +then when we turn it on we actually look + + align:start position:0% +then when we turn it on we actually look + + + align:start position:0% +then when we turn it on we actually look +to see whether the doctor takes the + + align:start position:0% +to see whether the doctor takes the + + + align:start position:0% +to see whether the doctor takes the +action that we suggested and if we're + + align:start position:0% +action that we suggested and if we're + + + align:start position:0% +action that we suggested and if we're +doing it in this randomized mode we + + align:start position:0% +doing it in this randomized mode we + + + align:start position:0% +doing it in this randomized mode we +would then look to see whether the + + align:start position:0% +would then look to see whether the + + + align:start position:0% +would then look to see whether the +doctor takes the action we suggested + + align:start position:0% +doctor takes the action we suggested + + + align:start position:0% +doctor takes the action we suggested +more often in the case where we show the + + align:start position:0% +more often in the case where we show the + + + align:start position:0% +more often in the case where we show the +alert than where we generate the alert + + align:start position:0% +alert than where we generate the alert + + + align:start position:0% +alert than where we generate the alert +but sort of just log it and don't don't + + align:start position:0% +but sort of just log it and don't don't + + + align:start position:0% +but sort of just log it and don't don't +show it yeah + + align:start position:0% + + + + align:start position:0% + +so you mentioned how there's that sort + + align:start position:0% +so you mentioned how there's that sort + + + align:start position:0% +so you mentioned how there's that sort +of like right you said that kids have + + align:start position:0% +of like right you said that kids have + + + align:start position:0% +of like right you said that kids have +like my very limited understanding of + + align:start position:0% +like my very limited understanding of + + + align:start position:0% +like my very limited understanding of +like is that if you're flying like say + + align:start position:0% +like is that if you're flying like say + + + align:start position:0% +like is that if you're flying like say +below 10,000 people arms get turned off + + align:start position:0% +below 10,000 people arms get turned off + + + align:start position:0% +below 10,000 people arms get turned off +yep I don't know if there seems to be + + align:start position:0% +yep I don't know if there seems to be + + + align:start position:0% +yep I don't know if there seems to be +yes just because the technology workflow + + align:start position:0% +yes just because the technology workflow + + + align:start position:0% +yes just because the technology workflow +is not good sure enough what kind of + + align:start position:0% +is not good sure enough what kind of + + + align:start position:0% +is not good sure enough what kind of +question about the incentives between + + align:start position:0% +question about the incentives between + + + align:start position:0% +question about the incentives between +you know we try rights as we often don't + + align:start position:0% +you know we try rights as we often don't + + + align:start position:0% +you know we try rights as we often don't +know about the situations in a + + align:start position:0% +know about the situations in a + + + align:start position:0% +know about the situations in a +structured way the EHR so most of our + + align:start position:0% +structured way the EHR so most of our + + + align:start position:0% +structured way the EHR so most of our +alerts are suppressed in the operating + + align:start position:0% +alerts are suppressed in the operating + + + align:start position:0% +alerts are suppressed in the operating +room right so being an answer when a + + align:start position:0% +room right so being an answer when a + + + align:start position:0% +room right so being an answer when a +patient is on anesthesia you know their + + align:start position:0% +patient is on anesthesia you know their + + + align:start position:0% +patient is on anesthesia you know their +physiology is being sort of manually + + align:start position:0% +physiology is being sort of manually + + + align:start position:0% +physiology is being sort of manually +controlled by a doctor and so we often + + align:start position:0% +controlled by a doctor and so we often + + + align:start position:0% +controlled by a doctor and so we often +suppress the alert um in those + + align:start position:0% +suppress the alert um in those + + + align:start position:0% +suppress the alert um in those +situations I guess I didn't say to say + + align:start position:0% +situations I guess I didn't say to say + + + align:start position:0% +situations I guess I didn't say to say +the question but the question was do we + + align:start position:0% +the question but the question was do we + + + align:start position:0% +the question but the question was do we +try to take situations into account or + + align:start position:0% +try to take situations into account or + + + align:start position:0% +try to take situations into account or +how much can we we didn't use to know + + align:start position:0% +how much can we we didn't use to know + + + align:start position:0% +how much can we we didn't use to know +that a code blue was going on because we + + align:start position:0% +that a code blue was going on because we + + + align:start position:0% +that a code blue was going on because we +used to do almost or a code blue + + align:start position:0% +used to do almost or a code blue + + + align:start position:0% +used to do almost or a code blue +documentation on paper we now use this + + align:start position:0% +documentation on paper we now use this + + + align:start position:0% +documentation on paper we now use this +code narrator right so we can tell when + + align:start position:0% +code narrator right so we can tell when + + + align:start position:0% +code narrator right so we can tell when +a code blue starts when a code blue ends + + align:start position:0% +a code blue starts when a code blue ends + + + align:start position:0% +a code blue starts when a code blue ends +a Code Blue is like a cardiac arrest the + + align:start position:0% +a Code Blue is like a cardiac arrest the + + + align:start position:0% +a Code Blue is like a cardiac arrest the +resuscitation of the patient and so we + + align:start position:0% +resuscitation of the patient and so we + + + align:start position:0% +resuscitation of the patient and so we +actually do increasingly turn a lot of + + align:start position:0% +actually do increasingly turn a lot of + + + align:start position:0% +actually do increasingly turn a lot of +alerting off during a code blue I get an + + align:start position:0% +alerting off during a code blue I get an + + + align:start position:0% +alerting off during a code blue I get an +email or a page whenever a doctor + + align:start position:0% +email or a page whenever a doctor + + + align:start position:0% +email or a page whenever a doctor +overrides an alert and like writes a + + align:start position:0% +overrides an alert and like writes a + + + align:start position:0% +overrides an alert and like writes a +cranky message and they'll often say + + align:start position:0% +cranky message and they'll often say + + + align:start position:0% +cranky message and they'll often say +something like you know this patient is + + align:start position:0% +something like you know this patient is + + + align:start position:0% +something like you know this patient is +dying of the you know of a myocardial + + align:start position:0% +dying of the you know of a myocardial + + + align:start position:0% +dying of the you know of a myocardial +infarction right now and you're + + align:start position:0% +infarction right now and you're + + + align:start position:0% +infarction right now and you're +bothering me about this influenza + + align:start position:0% +bothering me about this influenza + + + align:start position:0% +bothering me about this influenza +vaccination and then what I'll do is + + align:start position:0% +vaccination and then what I'll do is + + + align:start position:0% +vaccination and then what I'll do is +I'll go back you know seriously I + + align:start position:0% +I'll go back you know seriously I + + + align:start position:0% +I'll go back you know seriously I +thought yesterday and so what authors + + align:start position:0% +thought yesterday and so what authors + + + align:start position:0% +thought yesterday and so what authors +I'll go back and look in the record and + + align:start position:0% +I'll go back and look in the record and + + + align:start position:0% +I'll go back and look in the record and +say what signs did I have this patient + + align:start position:0% +say what signs did I have this patient + + + align:start position:0% +say what signs did I have this patient +sort of in extremis and in that + + align:start position:0% +sort of in extremis and in that + + + align:start position:0% +sort of in extremis and in that +particular case it was a patient who + + align:start position:0% +particular case it was a patient who + + + align:start position:0% +particular case it was a patient who +came into the IDI and my very little + + align:start position:0% +came into the IDI and my very little + + + align:start position:0% +came into the IDI and my very little +documentation had been started and so + + align:start position:0% +documentation had been started and so + + + align:start position:0% +documentation had been started and so +there actually were very few signs that + + align:start position:0% +there actually were very few signs that + + + align:start position:0% +there actually were very few signs that +the patient was in the sort of acute + + align:start position:0% +the patient was in the sort of acute + + + align:start position:0% +the patient was in the sort of acute +state I think you know some day couldn't + + align:start position:0% +state I think you know some day couldn't + + + align:start position:0% +state I think you know some day couldn't +be smarter about integrating monitor + + align:start position:0% +be smarter about integrating monitor + + + align:start position:0% +be smarter about integrating monitor +data and device data to figure that out + + align:start position:0% +data and device data to figure that out + + + align:start position:0% +data and device data to figure that out +but at that point we didn't have a good + + align:start position:0% +but at that point we didn't have a good + + + align:start position:0% +but at that point we didn't have a good +structured data a woman in the chart + + align:start position:0% +structured data a woman in the chart + + + align:start position:0% +structured data a woman in the chart +that said this patient is like so ill + + align:start position:0% +that said this patient is like so ill + + + align:start position:0% +that said this patient is like so ill +that it's offensive to suggest the + + align:start position:0% +that it's offensive to suggest the + + + align:start position:0% +that it's offensive to suggest the +influenza vaccination right now so now + + align:start position:0% +influenza vaccination right now so now + + + align:start position:0% +influenza vaccination right now so now +there are hospitals that have started + + align:start position:0% +there are hospitals that have started + + + align:start position:0% +there are hospitals that have started +experiment + + align:start position:0% +experiment + + + align:start position:0% +experiment +thing with things like acquiring data + + align:start position:0% +thing with things like acquiring data + + + align:start position:0% +thing with things like acquiring data +from the ambulance as the patient is + + align:start position:0% +from the ambulance as the patient is + + + align:start position:0% +from the ambulance as the patient is +coming in so that the IDI is already + + align:start position:0% +coming in so that the IDI is already + + + align:start position:0% +coming in so that the IDI is already +primed with preliminary data and in that + + align:start position:0% +primed with preliminary data and in that + + + align:start position:0% +primed with preliminary data and in that +circumstance you could tell so this is + + align:start position:0% +circumstance you could tell so this is + + + align:start position:0% +circumstance you could tell so this is +the interoperability challenge right so + + align:start position:0% +the interoperability challenge right so + + + align:start position:0% +the interoperability challenge right so +we actually get the run achieve all the + + align:start position:0% +we actually get the run achieve all the + + + align:start position:0% +we actually get the run achieve all the +amulets data to us it comes in as a PDF + + align:start position:0% +amulets data to us it comes in as a PDF + + + align:start position:0% +amulets data to us it comes in as a PDF +that's transmitted from the ambulance + + align:start position:0% +that's transmitted from the ambulance + + + align:start position:0% +that's transmitted from the ambulance +emergency management system to our EHR + + align:start position:0% +emergency management system to our EHR + + + align:start position:0% +emergency management system to our EHR +and so it's not coming in in a way that + + align:start position:0% +and so it's not coming in in a way that + + + align:start position:0% +and so it's not coming in in a way that +we can sort of read it well but your + + align:start position:0% +we can sort of read it well but your + + + align:start position:0% +we can sort of read it well but your +point exactly if we were better at + + align:start position:0% +point exactly if we were better at + + + align:start position:0% +point exactly if we were better at +interoperability I've also talked to + + align:start position:0% +interoperability I've also talked to + + + align:start position:0% +interoperability I've also talked to +hospitals who you know use things like + + align:start position:0% +hospitals who you know use things like + + + align:start position:0% +hospitals who you know use things like +you know video cameras and people's + + align:start position:0% +you know video cameras and people's + + + align:start position:0% +you know video cameras and people's +badges but there's 50 people hovering + + align:start position:0% +badges but there's 50 people hovering + + + align:start position:0% +badges but there's 50 people hovering +around a patient that's a sign that + + align:start position:0% +around a patient that's a sign that + + + align:start position:0% +around a patient that's a sign that +something bad is happening so we might + + align:start position:0% +something bad is happening so we might + + + align:start position:0% +something bad is happening so we might +be able to use something like that but + + align:start position:0% +be able to use something like that but + + + align:start position:0% +be able to use something like that but +yeah where we'd like to be better at + + align:start position:0% +yeah where we'd like to be better at + + + align:start position:0% +yeah where we'd like to be better at +that so what why did hl7 version 3 not + + align:start position:0% +that so what why did hl7 version 3 not + + + align:start position:0% +that so what why did hl7 version 3 not +solve all these this is a good + + align:start position:0% +solve all these this is a good + + + align:start position:0% +solve all these this is a good +philosophical question come to BMI 701 + + align:start position:0% +philosophical question come to BMI 701 + + + align:start position:0% +philosophical question come to BMI 701 +and 702 and we'll talk about it and + + align:start position:0% +and 702 and we'll talk about it and + + + align:start position:0% +and 702 and we'll talk about it and +Hertz hl7 version 2 fees questions + + align:start position:0% +Hertz hl7 version 2 fees questions + + + align:start position:0% +Hertz hl7 version 2 fees questions +version 2 is a very practical standard + + align:start position:0% +version 2 is a very practical standard + + + align:start position:0% +version 2 is a very practical standard +version 3 was a very deeply + + align:start position:0% +version 3 was a very deeply + + + align:start position:0% +version 3 was a very deeply +philosophical standard as Perosh + + align:start position:0% +philosophical standard as Perosh + + + align:start position:0% +philosophical standard as Perosh +aspirational that never quite caught on + + align:start position:0% +aspirational that never quite caught on + + + align:start position:0% +aspirational that never quite caught on +it did in pieces I mean smart if I there + + align:start position:0% +it did in pieces I mean smart if I there + + + align:start position:0% +it did in pieces I mean smart if I there +is a simplification of that + + align:start position:0% + + + + align:start position:0% + +yes sir danke + + align:start position:0% + + + + align:start position:0% + +yeah I mean there's calibration right so + + align:start position:0% +yeah I mean there's calibration right so + + + align:start position:0% +yeah I mean there's calibration right so +we can say this model works particularly + + align:start position:0% +we can say this model works particularly + + + align:start position:0% +we can say this model works particularly +well in these patients or not as well in + + align:start position:0% +well in these patients or not as well in + + + align:start position:0% +well in these patients or not as well in +these patients there are some you know + + align:start position:0% +these patients there are some you know + + + align:start position:0% +these patients there are some you know +very simple equations or models that we + + align:start position:0% +very simple equations or models that we + + + align:start position:0% +very simple equations or models that we +use for example where we use a different + + align:start position:0% +use for example where we use a different + + + align:start position:0% +use for example where we use a different +model in African American patients + + align:start position:0% +model in African American patients + + + align:start position:0% +model in African American patients +versus even on African American patients + + align:start position:0% +versus even on African American patients + + + align:start position:0% +versus even on African American patients +because there's some data that says this + + align:start position:0% +because there's some data that says this + + + align:start position:0% +because there's some data that says this +model is better calibrated in this + + align:start position:0% +model is better calibrated in this + + + align:start position:0% +model is better calibrated in this +subgroup of patients versus another I do + + align:start position:0% +subgroup of patients versus another I do + + + align:start position:0% +subgroup of patients versus another I do +think though to your point that there's + + align:start position:0% +think though to your point that there's + + + align:start position:0% +think though to your point that there's +a suggestion you know an inference from + + align:start position:0% +a suggestion you know an inference from + + + align:start position:0% +a suggestion you know an inference from +a model this patient is that at risk of + + align:start position:0% +a model this patient is that at risk of + + + align:start position:0% +a model this patient is that at risk of +a fall and then there's this whole set + + align:start position:0% +a fall and then there's this whole set + + + align:start position:0% +a fall and then there's this whole set +of you know kind of value judgments and + + align:start position:0% +of you know kind of value judgments and + + + align:start position:0% +of you know kind of value judgments and +beliefs and knowledge and understanding + + align:start position:0% +beliefs and knowledge and understanding + + + align:start position:0% +beliefs and knowledge and understanding +of a patient's circumstances that are + + align:start position:0% +of a patient's circumstances that are + + + align:start position:0% +of a patient's circumstances that are +very human and I think that that's + + align:start position:0% +very human and I think that that's + + + align:start position:0% +very human and I think that that's +largely why we deliver these suggestions + + align:start position:0% +largely why we deliver these suggestions + + + align:start position:0% +largely why we deliver these suggestions +to in doctor to a nurse and then that + + align:start position:0% +to in doctor to a nurse and then that + + + align:start position:0% +to in doctor to a nurse and then that +human uses that information plus their + + align:start position:0% +human uses that information plus their + + + align:start position:0% +human uses that information plus their +expertise and their relationship and + + align:start position:0% +expertise and their relationship and + + + align:start position:0% +expertise and their relationship and +their experience to make a suggestion + + align:start position:0% +their experience to make a suggestion + + + align:start position:0% +their experience to make a suggestion +rather than you know just having the + + align:start position:0% +rather than you know just having the + + + align:start position:0% +rather than you know just having the +computer adjust the knob on the + + align:start position:0% +computer adjust the knob on the + + + align:start position:0% +computer adjust the knob on the +ventilator itself question that people + + align:start position:0% +ventilator itself question that people + + + align:start position:0% +ventilator itself question that people +always ask me and if you should ask me + + align:start position:0% +always ask me and if you should ask me + + + align:start position:0% +always ask me and if you should ask me +is when we eventually not need that that + + align:start position:0% +is when we eventually not need that that + + + align:start position:0% +is when we eventually not need that that +human and I think I'm more optimistic + + align:start position:0% +human and I think I'm more optimistic + + + align:start position:0% +human and I think I'm more optimistic +than some people that there are cases + + align:start position:0% +than some people that there are cases + + + align:start position:0% +than some people that there are cases +where the computer is good enough or the + + align:start position:0% +where the computer is good enough or the + + + align:start position:0% +where the computer is good enough or the +human is poor enough that it would be + + align:start position:0% +human is poor enough that it would be + + + align:start position:0% +human is poor enough that it would be +safe to sort of have a close to closed + + align:start position:0% +safe to sort of have a close to closed + + + align:start position:0% +safe to sort of have a close to closed +loop however I think those cases are not + + align:start position:0% +loop however I think those cases are not + + + align:start position:0% +loop however I think those cases are not +the norm I think that there'll be more + + align:start position:0% +the norm I think that there'll be more + + + align:start position:0% +the norm I think that there'll be more +cases where where human doctors are + + align:start position:0% +cases where where human doctors are + + + align:start position:0% +cases where where human doctors are +still very much very much needed so I + + align:start position:0% +still very much very much needed so I + + + align:start position:0% +still very much very much needed so I +just add that there are tasks where + + align:start position:0% +just add that there are tasks where + + + align:start position:0% +just add that there are tasks where +where patients are fungible in the words + + align:start position:0% +where patients are fungible in the words + + + align:start position:0% +where patients are fungible in the words +that I used a few lectures ago so for + + align:start position:0% +that I used a few lectures ago so for + + + align:start position:0% +that I used a few lectures ago so for +example a lot of hospitals are + + align:start position:0% +example a lot of hospitals are + + + align:start position:0% +example a lot of hospitals are +developing models that predict whether a + + align:start position:0% +developing models that predict whether a + + + align:start position:0% +developing models that predict whether a +patient will show up for their optional + + align:start position:0% +patient will show up for their optional + + + align:start position:0% +patient will show up for their optional +surgery and because then if they can do + + align:start position:0% +surgery and because then if they can do + + + align:start position:0% +surgery and because then if they can do +a better job of over-scheduling the + + align:start position:0% +a better job of over-scheduling the + + + align:start position:0% +a better job of over-scheduling the +operating room in the same way that the + + align:start position:0% +operating room in the same way that the + + + align:start position:0% +operating room in the same way that the +airline's over oversell seats because + + align:start position:0% +airline's over oversell seats because + + + align:start position:0% +airline's over oversell seats because +statistically you could win doing that + + align:start position:0% +statistically you could win doing that + + + align:start position:0% +statistically you could win doing that +those are very safe predictions because + + align:start position:0% +those are very safe predictions because + + + align:start position:0% +those are very safe predictions because +the worst thing that happens is you get + + align:start position:0% +the worst thing that happens is you get + + + align:start position:0% +the worst thing that happens is you get +delayed but it's not going to have a + + align:start position:0% +delayed but it's not going to have a + + + align:start position:0% +delayed but it's not going to have a +harmful outcome on upon an individual + + align:start position:0% +harmful outcome on upon an individual + + + align:start position:0% +harmful outcome on upon an individual +patient University there are people that + + align:start position:0% +patient University there are people that + + + align:start position:0% +patient University there are people that +are working on machine learning systems + + align:start position:0% +are working on machine learning systems + + + align:start position:0% +are working on machine learning systems +for dosing insulin or adjusting people's + + align:start position:0% +for dosing insulin or adjusting people's + + + align:start position:0% +for dosing insulin or adjusting people's +ventilator settings and + + align:start position:0% +ventilator settings and + + + align:start position:0% +ventilator settings and +those are a high area yeah alright last + + align:start position:0% +those are a high area yeah alright last + + + align:start position:0% +those are a high area yeah alright last +question because we have to wrap up + + align:start position:0% + + + + align:start position:0% + +yes + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% + + + + align:start position:0% + +retraining yeah absolutely so the + + align:start position:0% +retraining yeah absolutely so the + + + align:start position:0% +retraining yeah absolutely so the +question is the kind of set and forget + + align:start position:0% +question is the kind of set and forget + + + align:start position:0% +question is the kind of set and forget +right we build the model of the Model T + + align:start position:0% +right we build the model of the Model T + + + align:start position:0% +right we build the model of the Model T +become stale should we update the model + + align:start position:0% +become stale should we update the model + + + align:start position:0% +become stale should we update the model +and how do we decide to do that I mean + + align:start position:0% +and how do we decide to do that I mean + + + align:start position:0% +and how do we decide to do that I mean +we're using you know it depends what you + + align:start position:0% +we're using you know it depends what you + + + align:start position:0% +we're using you know it depends what you +define as a model we're using tables and + + align:start position:0% +define as a model we're using tables and + + + align:start position:0% +define as a model we're using tables and +rules that we develop since the 1970s I + + align:start position:0% +rules that we develop since the 1970s I + + + align:start position:0% +rules that we develop since the 1970s I +think we have a pretty high desire to + + align:start position:0% +think we have a pretty high desire to + + + align:start position:0% +think we have a pretty high desire to +sort of purely revisit those it's a + + align:start position:0% +sort of purely revisit those it's a + + + align:start position:0% +sort of purely revisit those it's a +problem in the field in France it's + + align:start position:0% +problem in the field in France it's + + + align:start position:0% +problem in the field in France it's +called knowledge management or knowledge + + align:start position:0% +called knowledge management or knowledge + + + align:start position:0% +called knowledge management or knowledge +engineering right how do we sort of + + align:start position:0% +engineering right how do we sort of + + + align:start position:0% +engineering right how do we sort of +remember which of our knowledge bases + + align:start position:0% +remember which of our knowledge bases + + + align:start position:0% +remember which of our knowledge bases +need to be started check again or + + align:start position:0% +need to be started check again or + + + align:start position:0% +need to be started check again or +updated and we'll often you know just as + + align:start position:0% +updated and we'll often you know just as + + + align:start position:0% +updated and we'll often you know just as +a standard retrain a model we + + align:start position:0% +a standard retrain a model we + + + align:start position:0% +a standard retrain a model we +re-evaluated knowledge base every six + + align:start position:0% +re-evaluated knowledge base every six + + + align:start position:0% +re-evaluated knowledge base every six +months or every year because it's both + + align:start position:0% +months or every year because it's both + + + align:start position:0% +months or every year because it's both +harmful to patients if this stuff's out + + align:start position:0% +harmful to patients if this stuff's out + + + align:start position:0% +harmful to patients if this stuff's out +of date and it also makes us look stupid + + align:start position:0% +of date and it also makes us look stupid + + + align:start position:0% +of date and it also makes us look stupid +right so if you know there's a new paper + + align:start position:0% +right so if you know there's a new paper + + + align:start position:0% +right so if you know there's a new paper +that comes out and says beta blockers + + align:start position:0% +that comes out and says beta blockers + + + align:start position:0% +that comes out and says beta blockers +are terrible poison and then we keep + + align:start position:0% +are terrible poison and then we keep + + + align:start position:0% +are terrible poison and then we keep +suggesting them then people no longer + + align:start position:0% +suggesting them then people no longer + + + align:start position:0% +suggesting them then people no longer +believe suggestions we make that said we + + align:start position:0% +believe suggestions we make that said we + + + align:start position:0% +believe suggestions we make that said we +still make mistakes right I mean things + + align:start position:0% +still make mistakes right I mean things + + + align:start position:0% +still make mistakes right I mean things +happen all the time a lot of my work has + + align:start position:0% +happen all the time a lot of my work has + + + align:start position:0% +happen all the time a lot of my work has +focused on malfunctions in these systems + + align:start position:0% +focused on malfunctions in these systems + + + align:start position:0% +focused on malfunctions in these systems +and so it's an example you know if + + align:start position:0% +and so it's an example you know if + + + align:start position:0% +and so it's an example you know if +apparently the pharmacy might change the + + align:start position:0% +apparently the pharmacy might change the + + + align:start position:0% +apparently the pharmacy might change the +code or ID number for a medicine or a + + align:start position:0% +code or ID number for a medicine or a + + + align:start position:0% +code or ID number for a medicine or a +new medicine might come on the market + + align:start position:0% +new medicine might come on the market + + + align:start position:0% +new medicine might come on the market +and we have to make sure to continually + + align:start position:0% +and we have to make sure to continually + + + align:start position:0% +and we have to make sure to continually +update the knowledge base so that we're + + align:start position:0% +update the knowledge base so that we're + + + align:start position:0% +update the knowledge base so that we're +not suggesting an old medicine or + + align:start position:0% +not suggesting an old medicine or + + + align:start position:0% +not suggesting an old medicine or +overlooking fact the patient's already + + align:start position:0% +overlooking fact the patient's already + + + align:start position:0% +overlooking fact the patient's already +been prescribed a new medicine and so we + + align:start position:0% +been prescribed a new medicine and so we + + + align:start position:0% +been prescribed a new medicine and so we +tried to do that prospectively or + + align:start position:0% +tried to do that prospectively or + + + align:start position:0% +tried to do that prospectively or +practically but then we also tried to + + align:start position:0% +practically but then we also tried to + + + align:start position:0% +practically but then we also tried to +listen to feedback from users and fix + + align:start position:0% +listen to feedback from users and fix + + + align:start position:0% +listen to feedback from users and fix +things as we go school and just one one + + align:start position:0% +things as we go school and just one one + + + align:start position:0% +things as we go school and just one one +more comment on that so some things are + + align:start position:0% +more comment on that so some things are + + + align:start position:0% +more comment on that so some things are +done in real time there was a system + + align:start position:0% +done in real time there was a system + + + align:start position:0% +done in real time there was a system +many years ago at Intermountain health + + align:start position:0% +many years ago at Intermountain health + + + align:start position:0% +many years ago at Intermountain health +in Salt Lake City where they were + + align:start position:0% +in Salt Lake City where they were + + + align:start position:0% +in Salt Lake City where they were +looking at what bugs were growing out of + + align:start position:0% +looking at what bugs were growing out of + + + align:start position:0% +looking at what bugs were growing out of +microbiology samples in the laboratory + + align:start position:0% +microbiology samples in the laboratory + + + align:start position:0% +microbiology samples in the laboratory +and of course that can change on an hour + + align:start position:0% +and of course that can change on an hour + + + align:start position:0% +and of course that can change on an hour +by hour or day to day basis and so they + + align:start position:0% +by hour or day to day basis and so they + + + align:start position:0% +by hour or day to day basis and so they +were updating those systems that warn + + align:start position:0% +were updating those systems that warn + + + align:start position:0% +were updating those systems that warn +you about the possibility of that kind + + align:start position:0% +you about the possibility of that kind + + + align:start position:0% +you about the possibility of that kind +of infection in real time by taking + + align:start position:0% +of infection in real time by taking + + + align:start position:0% +of infection in real time by taking +feeds directly from the laboratory all + + align:start position:0% +feeds directly from the laboratory all + + + align:start position:0% +feeds directly from the laboratory all +right thank you very much + + align:start position:0% +right thank you very much + + + align:start position:0% +right thank you very much +you + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/_OkTw766oCs.txt b/_OkTw766oCs.txt new file mode 100644 index 0000000000000000000000000000000000000000..645570eba7c73a4c50ebec8fbb0bd805a05cacd4 --- /dev/null +++ b/_OkTw766oCs.txt @@ -0,0 +1,8755 @@ +align:start position:0% + +this is 1401 + + align:start position:0% +this is 1401 + + + align:start position:0% +this is 1401 +i'm john gruber and uh this is uh + + align:start position:0% +i'm john gruber and uh this is uh + + + align:start position:0% +i'm john gruber and uh this is uh +microeconomics + + align:start position:0% +microeconomics + + + align:start position:0% +microeconomics +um today i want to i want to cover three + + align:start position:0% +um today i want to i want to cover three + + + align:start position:0% +um today i want to i want to cover three +things i want to talk about the course + + align:start position:0% +things i want to talk about the course + + + align:start position:0% +things i want to talk about the course +details + + align:start position:0% +details + + + align:start position:0% +details +uh i want about what is microeconomics + + align:start position:0% +uh i want about what is microeconomics + + + align:start position:0% +uh i want about what is microeconomics +and then i'll talk start our + + align:start position:0% +and then i'll talk start our + + + align:start position:0% +and then i'll talk start our +start uh the substance of the course by + + align:start position:0% +start uh the substance of the course by + + + align:start position:0% +start uh the substance of the course by +talking about supply and demand + + align:start position:0% +talking about supply and demand + + + align:start position:0% +talking about supply and demand +a couple of points about the course the + + align:start position:0% +a couple of points about the course the + + + align:start position:0% +a couple of points about the course the +course will have a distinct sort of + + align:start position:0% +course will have a distinct sort of + + + align:start position:0% +course will have a distinct sort of +policy + + align:start position:0% +policy + + + align:start position:0% +policy +angle to it i sort of do economic policy + + align:start position:0% +angle to it i sort of do economic policy + + + align:start position:0% +angle to it i sort of do economic policy +is government policy is my thing + + align:start position:0% +is government policy is my thing + + + align:start position:0% +is government policy is my thing +so i i think it's what makes economics + + align:start position:0% +so i i think it's what makes economics + + + align:start position:0% +so i i think it's what makes economics +exciting and it sort of offers + + align:start position:0% +exciting and it sort of offers + + + align:start position:0% +exciting and it sort of offers +i think an interesting angle to + + align:start position:0% +i think an interesting angle to + + + align:start position:0% +i think an interesting angle to +understand why we're learning what we're + + align:start position:0% +understand why we're learning what we're + + + align:start position:0% +understand why we're learning what we're +learning i think sometimes in an intro + + align:start position:0% +learning i think sometimes in an intro + + + align:start position:0% +learning i think sometimes in an intro +class it's sort of hard to understand + + align:start position:0% +class it's sort of hard to understand + + + align:start position:0% +class it's sort of hard to understand +why the heck you're doing things um + + align:start position:0% +why the heck you're doing things um + + + align:start position:0% +why the heck you're doing things um +however that's just sort of a slight + + align:start position:0% +however that's just sort of a slight + + + align:start position:0% +however that's just sort of a slight +flavor if you're really more interested + + align:start position:0% +flavor if you're really more interested + + + align:start position:0% +flavor if you're really more interested +in this i teach a whole course called + + align:start position:0% +in this i teach a whole course called + + + align:start position:0% +in this i teach a whole course called +1441. i'm not teaching it this year + + align:start position:0% +1441. i'm not teaching it this year + + + align:start position:0% +1441. i'm not teaching it this year +but it'll be taught by a visitor in the + + align:start position:0% +but it'll be taught by a visitor in the + + + align:start position:0% +but it'll be taught by a visitor in the +spring uh kristen butcher from wellesley + + align:start position:0% +spring uh kristen butcher from wellesley + + + align:start position:0% +spring uh kristen butcher from wellesley +and i'll be teaching it next year + + align:start position:0% +and i'll be teaching it next year + + + align:start position:0% +and i'll be teaching it next year +that dies much more into these policy + + align:start position:0% +that dies much more into these policy + + + align:start position:0% +that dies much more into these policy +issues so i'm going to sort of use + + align:start position:0% +issues so i'm going to sort of use + + + align:start position:0% +issues so i'm going to sort of use +government policy sort of an organizing + + align:start position:0% +government policy sort of an organizing + + + align:start position:0% +government policy sort of an organizing +theme but it won't be sort of the + + align:start position:0% +theme but it won't be sort of the + + + align:start position:0% +theme but it won't be sort of the +dominant theme of the class + + align:start position:0% +dominant theme of the class + + + align:start position:0% +dominant theme of the class +finally three points about my teaching + + align:start position:0% +finally three points about my teaching + + + align:start position:0% +finally three points about my teaching +style um i don't write everything in the + + align:start position:0% +style um i don't write everything in the + + + align:start position:0% +style um i don't write everything in the +board we're not in high school anymore + + align:start position:0% +board we're not in high school anymore + + + align:start position:0% +board we're not in high school anymore +you're actually responsible for what i + + align:start position:0% +you're actually responsible for what i + + + align:start position:0% +you're actually responsible for what i +say not what i write uh + + align:start position:0% +say not what i write uh + + + align:start position:0% +say not what i write uh +partly that's because my handwriting is + + align:start position:0% +partly that's because my handwriting is + + + align:start position:0% +partly that's because my handwriting is +brutal um as you can tell already + + align:start position:0% +brutal um as you can tell already + + + align:start position:0% +brutal um as you can tell already +um uh so what that means is please + + align:start position:0% +um uh so what that means is please + + + align:start position:0% +um uh so what that means is please +please do not be afraid to ask me what + + align:start position:0% +please do not be afraid to ask me what + + + align:start position:0% +please do not be afraid to ask me what +the hell i just wrote on the board + + align:start position:0% +the hell i just wrote on the board + + + align:start position:0% +the hell i just wrote on the board +okay there's no shame in that don't just + + align:start position:0% +okay there's no shame in that don't just + + + align:start position:0% +okay there's no shame in that don't just +lean to your neighbor and say what the + + align:start position:0% +lean to your neighbor and say what the + + + align:start position:0% +lean to your neighbor and say what the +hell is writing the board like + + align:start position:0% +hell is writing the board like + + + align:start position:0% +hell is writing the board like +ask me because if you can't read it i'm + + align:start position:0% +ask me because if you can't read it i'm + + + align:start position:0% +ask me because if you can't read it i'm +sure someone else can't read it so feel + + align:start position:0% +sure someone else can't read it so feel + + + align:start position:0% +sure someone else can't read it so feel +free to ask + + align:start position:0% +free to ask + + + align:start position:0% +free to ask +and in general please feel free to + + align:start position:0% +and in general please feel free to + + + align:start position:0% +and in general please feel free to +engage with questions in this class + + align:start position:0% +engage with questions in this class + + + align:start position:0% +engage with questions in this class +the other point of my teaching style is + + align:start position:0% +the other point of my teaching style is + + + align:start position:0% +the other point of my teaching style is +i talk way too fast + + align:start position:0% +i talk way too fast + + + align:start position:0% +i talk way too fast +and the longer i go there's a + + align:start position:0% +and the longer i go there's a + + + align:start position:0% +and the longer i go there's a +mathematical function which is the + + align:start position:0% +mathematical function which is the + + + align:start position:0% +mathematical function which is the +longer i go without interruption the + + align:start position:0% +longer i go without interruption the + + + align:start position:0% +longer i go without interruption the +faster i speak + + align:start position:0% +faster i speak + + + align:start position:0% +faster i speak +until i just spin off okay so basically + + align:start position:0% +until i just spin off okay so basically + + + align:start position:0% +until i just spin off okay so basically +please ask questions if anything's not + + align:start position:0% +please ask questions if anything's not + + + align:start position:0% +please ask questions if anything's not +clear or you just want to + + align:start position:0% +clear or you just want to + + + align:start position:0% +clear or you just want to +ask questions about some related tangent + + align:start position:0% +ask questions about some related tangent + + + align:start position:0% +ask questions about some related tangent +or whatever please feel free to do so + + align:start position:0% +or whatever please feel free to do so + + + align:start position:0% +or whatever please feel free to do so +you might think how would that work in a + + align:start position:0% +you might think how would that work in a + + + align:start position:0% +you might think how would that work in a +class this big there's always way too + + align:start position:0% +class this big there's always way too + + + align:start position:0% +class this big there's always way too +few questions + + align:start position:0% +few questions + + + align:start position:0% +few questions +even a class is big so never be afraid + + align:start position:0% +even a class is big so never be afraid + + + align:start position:0% +even a class is big so never be afraid +that like it'll slow me down or whatever + + align:start position:0% +that like it'll slow me down or whatever + + + align:start position:0% +that like it'll slow me down or whatever +i ask a question we have plenty of time + + align:start position:0% +i ask a question we have plenty of time + + + align:start position:0% +i ask a question we have plenty of time +on the class + + align:start position:0% +on the class + + + align:start position:0% +on the class +and you'll be doing your classmates a + + align:start position:0% +and you'll be doing your classmates a + + + align:start position:0% +and you'll be doing your classmates a +favor because it'll slow me down + + align:start position:0% +favor because it'll slow me down + + + align:start position:0% +favor because it'll slow me down +um finally last point i have this + + align:start position:0% +um finally last point i have this + + + align:start position:0% +um finally last point i have this +terrible tendency to use the term + + align:start position:0% +terrible tendency to use the term + + + align:start position:0% +terrible tendency to use the term +guys in a gender-neutral way so this + + align:start position:0% +guys in a gender-neutral way so this + + + align:start position:0% +guys in a gender-neutral way so this +class i like to see looks like it's a + + align:start position:0% +class i like to see looks like it's a + + + align:start position:0% +class i like to see looks like it's a +fairly healthy representation both males + + align:start position:0% +fairly healthy representation both males + + + align:start position:0% +fairly healthy representation both males +and females when i say guys i don't mean + + align:start position:0% +and females when i say guys i don't mean + + + align:start position:0% +and females when i say guys i don't mean +men i mean people + + align:start position:0% +men i mean people + + + align:start position:0% +men i mean people +i mean people so don't take it women + + align:start position:0% +i mean people so don't take it women + + + align:start position:0% +i mean people so don't take it women +don't take it personally + + align:start position:0% +don't take it personally + + + align:start position:0% +don't take it personally +guys means economic agents it means + + align:start position:0% +guys means economic agents it means + + + align:start position:0% +guys means economic agents it means +people it doesn't mean men it's just the + + align:start position:0% +people it doesn't mean men it's just the + + + align:start position:0% +people it doesn't mean men it's just the +way just a bad tendency drives my life + + align:start position:0% +way just a bad tendency drives my life + + + align:start position:0% +way just a bad tendency drives my life +crazy but + + align:start position:0% +crazy but + + + align:start position:0% +crazy but +i've decided better to just apologize up + + align:start position:0% +i've decided better to just apologize up + + + align:start position:0% +i've decided better to just apologize up +front than try to + + align:start position:0% +front than try to + + + align:start position:0% +front than try to +try to fix it throughout which is + + align:start position:0% +try to fix it throughout which is + + + align:start position:0% +try to fix it throughout which is +impossible okay + + align:start position:0% +impossible okay + + + align:start position:0% +impossible okay +so let's talk about what is + + align:start position:0% +so let's talk about what is + + + align:start position:0% +so let's talk about what is +microeconomics okay + + align:start position:0% +microeconomics okay + + + align:start position:0% +microeconomics okay +so fundamentally microeconomics + + align:start position:0% +so fundamentally microeconomics + + + align:start position:0% +so fundamentally microeconomics +how people took ap high school econ + + align:start position:0% +how people took ap high school econ + + + align:start position:0% +how people took ap high school econ +okay um how many people + + align:start position:0% +okay um how many people + + + align:start position:0% +okay um how many people +for how many for how many was it taught + + align:start position:0% +for how many for how many was it taught + + + align:start position:0% +for how many for how many was it taught +really well + + align:start position:0% +really well + + + align:start position:0% +really well +okay that's about that right that's why + + align:start position:0% +okay that's about that right that's why + + + align:start position:0% +okay that's about that right that's why +i did my high school online class that's + + align:start position:0% +i did my high school online class that's + + + align:start position:0% +i did my high school online class that's +the answer i wanted to hear + + align:start position:0% +the answer i wanted to hear + + + align:start position:0% +the answer i wanted to hear +um uh okay so uh tell your friends still + + align:start position:0% +um uh okay so uh tell your friends still + + + align:start position:0% +um uh okay so uh tell your friends still +in high school + + align:start position:0% +in high school + + + align:start position:0% +in high school +we're taking its lecon if your high + + align:start position:0% +we're taking its lecon if your high + + + align:start position:0% +we're taking its lecon if your high +school econ teacher isn't great tell + + align:start position:0% +school econ teacher isn't great tell + + + align:start position:0% +school econ teacher isn't great tell +them to go on edx and take the class + + align:start position:0% +them to go on edx and take the class + + + align:start position:0% +them to go on edx and take the class +uh and and help out your friends still + + align:start position:0% +uh and and help out your friends still + + + align:start position:0% +uh and and help out your friends still +in high school + + align:start position:0% +in high school + + + align:start position:0% +in high school +okay so um what is microeconomics + + align:start position:0% +okay so um what is microeconomics + + + align:start position:0% +okay so um what is microeconomics +microeconomics is the study of how + + align:start position:0% +microeconomics is the study of how + + + align:start position:0% +microeconomics is the study of how +individuals and firms + + align:start position:0% +individuals and firms + + + align:start position:0% +individuals and firms +make decisions in a world of scarcity + + align:start position:0% + + + + align:start position:0% + +scarcity is what drives microeconomics + + align:start position:0% +scarcity is what drives microeconomics + + + align:start position:0% +scarcity is what drives microeconomics +okay + + align:start position:0% +okay + + + align:start position:0% +okay +basically what microeconomics is is a + + align:start position:0% +basically what microeconomics is is a + + + align:start position:0% +basically what microeconomics is is a +series + + align:start position:0% +series + + + align:start position:0% +series +of constrained optimization exercises + + align:start position:0% + + + + align:start position:0% + +where economic agents be they firms or + + align:start position:0% +where economic agents be they firms or + + + align:start position:0% +where economic agents be they firms or +individuals + + align:start position:0% +individuals + + + align:start position:0% +individuals +try to make themselves as well off as + + align:start position:0% +try to make themselves as well off as + + + align:start position:0% +try to make themselves as well off as +possible + + align:start position:0% +possible + + + align:start position:0% +possible +given their constraints yeah + + align:start position:0% + + + + align:start position:0% + +i will but not as much as i should uh + + align:start position:0% +i will but not as much as i should uh + + + align:start position:0% +i will but not as much as i should uh +essentially we have another course in + + align:start position:0% +essentially we have another course in + + + align:start position:0% +essentially we have another course in +the department called 1413 + + align:start position:0% +the department called 1413 + + + align:start position:0% +the department called 1413 +behavioral economics which gets in that + + align:start position:0% +behavioral economics which gets in that + + + align:start position:0% +behavioral economics which gets in that +much more i will sprinkle it throughout + + align:start position:0% +much more i will sprinkle it throughout + + + align:start position:0% +much more i will sprinkle it throughout +but uh + + align:start position:0% +but uh + + + align:start position:0% +but uh +but not as much as i actually believe in + + align:start position:0% +but not as much as i actually believe in + + + align:start position:0% +but not as much as i actually believe in +it uh in other words the + + align:start position:0% +it uh in other words the + + + align:start position:0% +it uh in other words the +way we think about economics is it's + + align:start position:0% +way we think about economics is it's + + + align:start position:0% +way we think about economics is it's +best to sort of get the basics down + + align:start position:0% +best to sort of get the basics down + + + align:start position:0% +best to sort of get the basics down +before you start worrying about the + + align:start position:0% +before you start worrying about the + + + align:start position:0% +before you start worrying about the +deviations + + align:start position:0% +deviations + + + align:start position:0% +deviations +find better to climb the tree before you + + align:start position:0% +find better to climb the tree before you + + + align:start position:0% +find better to climb the tree before you +start going out in the branches + + align:start position:0% +start going out in the branches + + + align:start position:0% +start going out in the branches +um okay so basically um + + align:start position:0% +um okay so basically um + + + align:start position:0% +um okay so basically um +what this course is then about is it's + + align:start position:0% +what this course is then about is it's + + + align:start position:0% +what this course is then about is it's +about trade-offs + + align:start position:0% + + + + align:start position:0% + +it's about how do you given that you're + + align:start position:0% +it's about how do you given that you're + + + align:start position:0% +it's about how do you given that you're +constrained how do you trade off things + + align:start position:0% +constrained how do you trade off things + + + align:start position:0% +constrained how do you trade off things +to make yourself as well off as possible + + align:start position:0% +to make yourself as well off as possible + + + align:start position:0% +to make yourself as well off as possible +and behind this notion of trade-offs is + + align:start position:0% +and behind this notion of trade-offs is + + + align:start position:0% +and behind this notion of trade-offs is +going to be + + align:start position:0% +going to be + + + align:start position:0% +going to be +i'll say about a hundred times this is + + align:start position:0% +i'll say about a hundred times this is + + + align:start position:0% +i'll say about a hundred times this is +the most important thing in the course + + align:start position:0% +the most important thing in the course + + + align:start position:0% +the most important thing in the course +so just ignore that + + align:start position:0% +so just ignore that + + + align:start position:0% +so just ignore that +but this is one of the most important + + align:start position:0% +but this is one of the most important + + + align:start position:0% +but this is one of the most important +things i'll say one of the most + + align:start position:0% +things i'll say one of the most + + + align:start position:0% +things i'll say one of the most +important things in the course + + align:start position:0% +important things in the course + + + align:start position:0% +important things in the course +is the notion of opportunity cost + + align:start position:0% + + + + align:start position:0% + +opportunity cost is a very important + + align:start position:0% +opportunity cost is a very important + + + align:start position:0% +opportunity cost is a very important +concept + + align:start position:0% +concept + + + align:start position:0% +concept +that uh we teach sort of the first + + align:start position:0% +that uh we teach sort of the first + + + align:start position:0% +that uh we teach sort of the first +concept we teach + + align:start position:0% +concept we teach + + + align:start position:0% +concept we teach +um which is that every action + + align:start position:0% +um which is that every action + + + align:start position:0% +um which is that every action +or every inaction has a cost + + align:start position:0% +or every inaction has a cost + + + align:start position:0% +or every inaction has a cost +and that you could have been doing + + align:start position:0% +and that you could have been doing + + + align:start position:0% +and that you could have been doing +something else instead okay + + align:start position:0% +something else instead okay + + + align:start position:0% +something else instead okay +so if you buy a shirt you could have + + align:start position:0% +so if you buy a shirt you could have + + + align:start position:0% +so if you buy a shirt you could have +bought pants + + align:start position:0% +bought pants + + + align:start position:0% +bought pants +if you sit at home and watch tv you + + align:start position:0% +if you sit at home and watch tv you + + + align:start position:0% +if you sit at home and watch tv you +could have been out working + + align:start position:0% +could have been out working + + + align:start position:0% +could have been out working +everything you do has the next best + + align:start position:0% +everything you do has the next best + + + align:start position:0% +everything you do has the next best +alternative you could have done instead + + align:start position:0% +alternative you could have done instead + + + align:start position:0% +alternative you could have done instead +and that is called the opportunity cost + + align:start position:0% +and that is called the opportunity cost + + + align:start position:0% +and that is called the opportunity cost +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and that's a critical concept in + + align:start position:0% +and that's a critical concept in + + + align:start position:0% +and that's a critical concept in +economics + + align:start position:0% +economics + + + align:start position:0% +economics +and that is why in some sense we are + + align:start position:0% +and that is why in some sense we are + + + align:start position:0% +and that is why in some sense we are +called referred to casually as the + + align:start position:0% +called referred to casually as the + + + align:start position:0% +called referred to casually as the +dismal science + + align:start position:0% +dismal science + + + align:start position:0% +dismal science +economics referred to as the dismal + + align:start position:0% +economics referred to as the dismal + + + align:start position:0% +economics referred to as the dismal +science first of all i'm flattered we're + + align:start position:0% +science first of all i'm flattered we're + + + align:start position:0% +science first of all i'm flattered we're +considered a science + + align:start position:0% +considered a science + + + align:start position:0% +considered a science +uh or called the dismal science because + + align:start position:0% +uh or called the dismal science because + + + align:start position:0% +uh or called the dismal science because +our whole point is that + + align:start position:0% +our whole point is that + + + align:start position:0% +our whole point is that +nothing is free there's always a + + align:start position:0% +nothing is free there's always a + + + align:start position:0% +nothing is free there's always a +trade-off there's always an opportunity + + align:start position:0% +trade-off there's always an opportunity + + + align:start position:0% +trade-off there's always an opportunity +cost + + align:start position:0% +cost + + + align:start position:0% +cost +anything you do you could be doing + + align:start position:0% +anything you do you could be doing + + + align:start position:0% +anything you do you could be doing +something else instead + + align:start position:0% +something else instead + + + align:start position:0% +something else instead +okay and your constrained optimization + + align:start position:0% +okay and your constrained optimization + + + align:start position:0% +okay and your constrained optimization +means you're gonna have to pass up one + + align:start position:0% +means you're gonna have to pass up one + + + align:start position:0% +means you're gonna have to pass up one +thing + + align:start position:0% +thing + + + align:start position:0% +thing +uh to do another now some may call it + + align:start position:0% +uh to do another now some may call it + + + align:start position:0% +uh to do another now some may call it +dismal + + align:start position:0% +dismal + + + align:start position:0% +dismal +but as a former mit undergraduate i call + + align:start position:0% +but as a former mit undergraduate i call + + + align:start position:0% +but as a former mit undergraduate i call +it fun and this is why i think mit + + align:start position:0% +it fun and this is why i think mit + + + align:start position:0% +it fun and this is why i think mit +is the perfect place to be teaching + + align:start position:0% +is the perfect place to be teaching + + + align:start position:0% +is the perfect place to be teaching +economics because mit + + align:start position:0% +economics because mit + + + align:start position:0% +economics because mit +engineering is all about constrained + + align:start position:0% +engineering is all about constrained + + + align:start position:0% +engineering is all about constrained +optimization that's what engineering is + + align:start position:0% +optimization that's what engineering is + + + align:start position:0% +optimization that's what engineering is +and economics is just the engine it's + + align:start position:0% +and economics is just the engine it's + + + align:start position:0% +and economics is just the engine it's +just the principles you learn + + align:start position:0% +just the principles you learn + + + align:start position:0% +just the principles you learn +you learn engineering um uh applied in + + align:start position:0% +you learn engineering um uh applied in + + + align:start position:0% +you learn engineering um uh applied in +different contexts + + align:start position:0% +different contexts + + + align:start position:0% +different contexts +so there's if we think about the 2007 + + align:start position:0% +so there's if we think about the 2007 + + + align:start position:0% +so there's if we think about the 2007 +contest that still exists with the + + align:start position:0% +contest that still exists with the + + + align:start position:0% +contest that still exists with the +robots + + align:start position:0% +robots + + + align:start position:0% +robots +2007. yeah okay the 2007 contest those + + align:start position:0% +2007. yeah okay the 2007 contest those + + + align:start position:0% +2007. yeah okay the 2007 contest those +you know is a contest where you're given + + align:start position:0% +you know is a contest where you're given + + + align:start position:0% +you know is a contest where you're given +a limited set of materials + + align:start position:0% +a limited set of materials + + + align:start position:0% +a limited set of materials +and you have to build a robot that does + + align:start position:0% +and you have to build a robot that does + + + align:start position:0% +and you have to build a robot that does +some tasks like pushing ping-pong balls + + align:start position:0% +some tasks like pushing ping-pong balls + + + align:start position:0% +some tasks like pushing ping-pong balls +off a table or something like that + + align:start position:0% +off a table or something like that + + + align:start position:0% +off a table or something like that +okay that's just constrained + + align:start position:0% +okay that's just constrained + + + align:start position:0% +okay that's just constrained +optimization it's got nothing to do with + + align:start position:0% +optimization it's got nothing to do with + + + align:start position:0% +optimization it's got nothing to do with +economics + + align:start position:0% +economics + + + align:start position:0% +economics +but it's constrained optimization so + + align:start position:0% +but it's constrained optimization so + + + align:start position:0% +but it's constrained optimization so +just think of + + align:start position:0% +just think of + + + align:start position:0% +just think of +um just think of uh microeconomics + + align:start position:0% +um just think of uh microeconomics + + + align:start position:0% +um just think of uh microeconomics +as like engineering but actually + + align:start position:0% +as like engineering but actually + + + align:start position:0% +as like engineering but actually +interesting okay + + align:start position:0% +interesting okay + + + align:start position:0% +interesting okay +so think of microeconomics as + + align:start position:0% +so think of microeconomics as + + + align:start position:0% +so think of microeconomics as +engineering but instead of building + + align:start position:0% +engineering but instead of building + + + align:start position:0% +engineering but instead of building +something to push a ping pong ball off + + align:start position:0% +something to push a ping pong ball off + + + align:start position:0% +something to push a ping pong ball off +tables + + align:start position:0% +tables + + + align:start position:0% +tables +you actually build people's lives and + + align:start position:0% +you actually build people's lives and + + + align:start position:0% +you actually build people's lives and +businesses and + + align:start position:0% +businesses and + + + align:start position:0% +businesses and +understand the decisions that drive our + + align:start position:0% +understand the decisions that drive our + + + align:start position:0% +understand the decisions that drive our +economy okay + + align:start position:0% +economy okay + + + align:start position:0% +economy okay +so the same principles that you could + + align:start position:0% +so the same principles that you could + + + align:start position:0% +so the same principles that you could +think of for engineering classes but + + align:start position:0% +think of for engineering classes but + + + align:start position:0% +think of for engineering classes but +applied to people's lives + + align:start position:0% +applied to people's lives + + + align:start position:0% +applied to people's lives +and that's why in fact modern economics + + align:start position:0% +and that's why in fact modern economics + + + align:start position:0% +and that's why in fact modern economics +was born in this room either this room + + align:start position:0% +was born in this room either this room + + + align:start position:0% +was born in this room either this room +or 26-100 + + align:start position:0% +or 26-100 + + + align:start position:0% +or 26-100 +okay by paul samuelson in the 1940s and + + align:start position:0% +okay by paul samuelson in the 1940s and + + + align:start position:0% +okay by paul samuelson in the 1940s and +50s + + align:start position:0% +50s + + + align:start position:0% +50s +who wrote the fundamental textbook that + + align:start position:0% +who wrote the fundamental textbook that + + + align:start position:0% +who wrote the fundamental textbook that +gave birth to modern economics + + align:start position:0% +gave birth to modern economics + + + align:start position:0% +gave birth to modern economics +because he was here and applied the kind + + align:start position:0% +because he was here and applied the kind + + + align:start position:0% +because he was here and applied the kind +of engineering principles + + align:start position:0% +of engineering principles + + + align:start position:0% +of engineering principles +of mit to actually develop the field of + + align:start position:0% +of mit to actually develop the field of + + + align:start position:0% +of mit to actually develop the field of +modern economics + + align:start position:0% +modern economics + + + align:start position:0% +modern economics +what we learned today was developed at + + align:start position:0% +what we learned today was developed at + + + align:start position:0% +what we learned today was developed at +mit so it's a great place to be learning + + align:start position:0% +mit so it's a great place to be learning + + + align:start position:0% +mit so it's a great place to be learning +it + + align:start position:0% +it + + + align:start position:0% +it +now with that as background okay any + + align:start position:0% +now with that as background okay any + + + align:start position:0% +now with that as background okay any +questions about that + + align:start position:0% +questions about that + + + align:start position:0% +questions about that +about what is microeconomics okay + + align:start position:0% +about what is microeconomics okay + + + align:start position:0% +about what is microeconomics okay +with that as background let's turn to + + align:start position:0% +with that as background let's turn to + + + align:start position:0% +with that as background let's turn to +our for the first + + align:start position:0% +our for the first + + + align:start position:0% +our for the first +model we'll talk about this semester + + align:start position:0% +model we'll talk about this semester + + + align:start position:0% +model we'll talk about this semester +which is the supply and demand model + + align:start position:0% + + + + align:start position:0% + +supply and demand now the way we're + + align:start position:0% +supply and demand now the way we're + + + align:start position:0% +supply and demand now the way we're +going to proceed in this course + + align:start position:0% +going to proceed in this course + + + align:start position:0% +going to proceed in this course +is going to drive you crazy because + + align:start position:0% +is going to drive you crazy because + + + align:start position:0% +is going to drive you crazy because +we're going to proceed + + align:start position:0% +we're going to proceed + + + align:start position:0% +we're going to proceed +by teaching very s as the very first + + align:start position:0% +by teaching very s as the very first + + + align:start position:0% +by teaching very s as the very first +question pointed out by teaching + + align:start position:0% +question pointed out by teaching + + + align:start position:0% +question pointed out by teaching +very simplified models okay we're gonna + + align:start position:0% +very simplified models okay we're gonna + + + align:start position:0% +very simplified models okay we're gonna +essentially + + align:start position:0% +essentially + + + align:start position:0% +essentially +what is a model a model is technically a + + align:start position:0% +what is a model a model is technically a + + + align:start position:0% +what is a model a model is technically a +description between any two or more + + align:start position:0% +description between any two or more + + + align:start position:0% +description between any two or more +economic variables or any two or more + + align:start position:0% +economic variables or any two or more + + + align:start position:0% +economic variables or any two or more +variables okay + + align:start position:0% +variables okay + + + align:start position:0% +variables okay +but unlike the models used in all your + + align:start position:0% +but unlike the models used in all your + + + align:start position:0% +but unlike the models used in all your +other classes + + align:start position:0% +other classes + + + align:start position:0% +other classes +these aren't laws by and large they're + + align:start position:0% +these aren't laws by and large they're + + + align:start position:0% +these aren't laws by and large they're +models so we don't have a relationship + + align:start position:0% +models so we don't have a relationship + + + align:start position:0% +models so we don't have a relationship +between energy and mass which you can + + align:start position:0% +between energy and mass which you can + + + align:start position:0% +between energy and mass which you can +write down to law and we're done + + align:start position:0% +write down to law and we're done + + + align:start position:0% +write down to law and we're done +we have models which are never 100 true + + align:start position:0% +we have models which are never 100 true + + + align:start position:0% +we have models which are never 100 true +but always pretty true pretty being + + align:start position:0% +but always pretty true pretty being + + + align:start position:0% +but always pretty true pretty being +somewhere between + + align:start position:0% +somewhere between + + + align:start position:0% +somewhere between +10 and 95 percent true okay so basically + + align:start position:0% +10 and 95 percent true okay so basically + + + align:start position:0% +10 and 95 percent true okay so basically +the idea is to make a trade-off we want + + align:start position:0% +the idea is to make a trade-off we want + + + align:start position:0% +the idea is to make a trade-off we want +to write down + + align:start position:0% +to write down + + + align:start position:0% +to write down +in our models a set of simplifying + + align:start position:0% +in our models a set of simplifying + + + align:start position:0% +in our models a set of simplifying +assumptions + + align:start position:0% +assumptions + + + align:start position:0% +assumptions +that allow us with a relatively small + + align:start position:0% +that allow us with a relatively small + + + align:start position:0% +that allow us with a relatively small +set of steps + + align:start position:0% +set of steps + + + align:start position:0% +set of steps +to capture relatively broad phenomena + + align:start position:0% +to capture relatively broad phenomena + + + align:start position:0% +to capture relatively broad phenomena +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so there's essentially a trade-off on + + align:start position:0% +so there's essentially a trade-off on + + + align:start position:0% +so there's essentially a trade-off on +the one hand we'd like a model + + align:start position:0% +the one hand we'd like a model + + + align:start position:0% +the one hand we'd like a model +that captures as well as possible the + + align:start position:0% +that captures as well as possible the + + + align:start position:0% +that captures as well as possible the +phenomenon the real world + + align:start position:0% +phenomenon the real world + + + align:start position:0% +phenomenon the real world +like equals nc squared but we want to do + + align:start position:0% +like equals nc squared but we want to do + + + align:start position:0% +like equals nc squared but we want to do +so + + align:start position:0% +so + + + align:start position:0% +so +in the most tractable possible way so + + align:start position:0% +in the most tractable possible way so + + + align:start position:0% +in the most tractable possible way so +that we can teach it from first + + align:start position:0% +that we can teach it from first + + + align:start position:0% +that we can teach it from first +principles and not + + align:start position:0% +principles and not + + + align:start position:0% +principles and not +you know don't need don't need an hour + + align:start position:0% +you know don't need don't need an hour + + + align:start position:0% +you know don't need don't need an hour +to teach every single uh + + align:start position:0% +to teach every single uh + + + align:start position:0% +to teach every single uh +every single insight we have okay so + + align:start position:0% +every single insight we have okay so + + + align:start position:0% +every single insight we have okay so +basically + + align:start position:0% +basically + + + align:start position:0% +basically +in economics we tend to resolve that by + + align:start position:0% +in economics we tend to resolve that by + + + align:start position:0% +in economics we tend to resolve that by +erroring on the side of + + align:start position:0% +erroring on the side of + + + align:start position:0% +erroring on the side of +tractability that is why i can teach you + + align:start position:0% +tractability that is why i can teach you + + + align:start position:0% +tractability that is why i can teach you +the entire field of microeconomics + + align:start position:0% +the entire field of microeconomics + + + align:start position:0% +the entire field of microeconomics +which is really sort of macro is kind of + + align:start position:0% +which is really sort of macro is kind of + + + align:start position:0% +which is really sort of macro is kind of +a fun application micro's really + + align:start position:0% +a fun application micro's really + + + align:start position:0% +a fun application micro's really +economics + + align:start position:0% +economics + + + align:start position:0% +economics +okay i could teach you the fire field of + + align:start position:0% +okay i could teach you the fire field of + + + align:start position:0% +okay i could teach you the fire field of +microeconomics at a semester because + + align:start position:0% +microeconomics at a semester because + + + align:start position:0% +microeconomics at a semester because +we're going to make a whole huge set + + align:start position:0% +we're going to make a whole huge set + + + align:start position:0% +we're going to make a whole huge set +of simplifying assumptions to make + + align:start position:0% +of simplifying assumptions to make + + + align:start position:0% +of simplifying assumptions to make +things tractable + + align:start position:0% +things tractable + + + align:start position:0% +things tractable +but the key thing is that you will be + + align:start position:0% +but the key thing is that you will be + + + align:start position:0% +but the key thing is that you will be +amazed at what these models will be able + + align:start position:0% +amazed at what these models will be able + + + align:start position:0% +amazed at what these models will be able +to do + + align:start position:0% +to do + + + align:start position:0% +to do +with a fairly simple set of models we'll + + align:start position:0% +with a fairly simple set of models we'll + + + align:start position:0% +with a fairly simple set of models we'll +be able to offer insights and explain a + + align:start position:0% +be able to offer insights and explain a + + + align:start position:0% +be able to offer insights and explain a +whole huge variety of phenomena + + align:start position:0% +whole huge variety of phenomena + + + align:start position:0% +whole huge variety of phenomena +never perfectly but always pretty well + + align:start position:0% +never perfectly but always pretty well + + + align:start position:0% +never perfectly but always pretty well +generally pretty well + + align:start position:0% +generally pretty well + + + align:start position:0% +generally pretty well +okay and so that is essentially the + + align:start position:0% +okay and so that is essentially the + + + align:start position:0% +okay and so that is essentially the +trade-off we're going to try to do + + align:start position:0% +trade-off we're going to try to do + + + align:start position:0% +trade-off we're going to try to do +uh this semester so the line i like is + + align:start position:0% +uh this semester so the line i like is + + + align:start position:0% +uh this semester so the line i like is +this the statistician george box + + align:start position:0% +this the statistician george box + + + align:start position:0% +this the statistician george box +said that all models are wrong but some + + align:start position:0% +said that all models are wrong but some + + + align:start position:0% +said that all models are wrong but some +are useful + + align:start position:0% +are useful + + + align:start position:0% +are useful +now obviously it doesn't apply to models + + align:start position:0% +now obviously it doesn't apply to models + + + align:start position:0% +now obviously it doesn't apply to models +models in the hard sciences but in the + + align:start position:0% +models in the hard sciences but in the + + + align:start position:0% +models in the hard sciences but in the +social sciences that's true + + align:start position:0% +social sciences that's true + + + align:start position:0% +social sciences that's true +and basically i'm going to write down a + + align:start position:0% +and basically i'm going to write down a + + + align:start position:0% +and basically i'm going to write down a +set of models like that + + align:start position:0% +set of models like that + + + align:start position:0% +set of models like that +now with every model i write down i'm + + align:start position:0% +now with every model i write down i'm + + + align:start position:0% +now with every model i write down i'm +going to try i would my goal is to have + + align:start position:0% +going to try i would my goal is to have + + + align:start position:0% +going to try i would my goal is to have +you understand it at three levels + + align:start position:0% +you understand it at three levels + + + align:start position:0% +you understand it at three levels +the first and most important level is + + align:start position:0% +the first and most important level is + + + align:start position:0% +the first and most important level is +the intuitive level + + align:start position:0% +the intuitive level + + + align:start position:0% +the intuitive level +okay the level which you sort of + + align:start position:0% +okay the level which you sort of + + + align:start position:0% +okay the level which you sort of +understand i call it passing the mom + + align:start position:0% +understand i call it passing the mom + + + align:start position:0% +understand i call it passing the mom +test + + align:start position:0% +test + + + align:start position:0% +test +you can go home and explain it to your + + align:start position:0% +you can go home and explain it to your + + + align:start position:0% +you can go home and explain it to your +mom at thanksgiving or at the end of the + + align:start position:0% +mom at thanksgiving or at the end of the + + + align:start position:0% +mom at thanksgiving or at the end of the +semester + + align:start position:0% +semester + + + align:start position:0% +semester +okay no offense to dads just call it the + + align:start position:0% +okay no offense to dads just call it the + + + align:start position:0% +okay no offense to dads just call it the +mom test + + align:start position:0% +mom test + + + align:start position:0% +mom test +okay so basically that's the intuitive + + align:start position:0% +okay so basically that's the intuitive + + + align:start position:0% +okay so basically that's the intuitive +level you really understand it way that + + align:start position:0% +level you really understand it way that + + + align:start position:0% +level you really understand it way that +you could explain it + + align:start position:0% +you could explain it + + + align:start position:0% +you could explain it +the second is graphical we were going to + + align:start position:0% +the second is graphical we were going to + + + align:start position:0% +the second is graphical we were going to +do + + align:start position:0% +do + + + align:start position:0% +do +most of our models here will develop in + + align:start position:0% +most of our models here will develop in + + + align:start position:0% +most of our models here will develop in +a graphical framework + + align:start position:0% +a graphical framework + + + align:start position:0% +a graphical framework +okay using xy graphs that we're really + + align:start position:0% +okay using xy graphs that we're really + + + align:start position:0% +okay using xy graphs that we're really +weak + + align:start position:0% +weak + + + align:start position:0% +weak +in economics we think delivers a lot of + + align:start position:0% +in economics we think delivers a lot of + + + align:start position:0% +in economics we think delivers a lot of +shorthand power + + align:start position:0% +shorthand power + + + align:start position:0% +shorthand power +and the third is mathematical okay the + + align:start position:0% +and the third is mathematical okay the + + + align:start position:0% +and the third is mathematical okay the +mathematical is probably the least + + align:start position:0% +mathematical is probably the least + + + align:start position:0% +mathematical is probably the least +important but it's the easiest to test + + align:start position:0% +important but it's the easiest to test + + + align:start position:0% +important but it's the easiest to test +you on + + align:start position:0% +you on + + + align:start position:0% +you on +so we're gonna need to know things + + align:start position:0% +so we're gonna need to know things + + + align:start position:0% +so we're gonna need to know things +mathematically uh as well + + align:start position:0% +mathematically uh as well + + + align:start position:0% +mathematically uh as well +okay um so let's start + + align:start position:0% +okay um so let's start + + + align:start position:0% +okay um so let's start +um by considering the supply and demand + + align:start position:0% +um by considering the supply and demand + + + align:start position:0% +um by considering the supply and demand +model + + align:start position:0% +model + + + align:start position:0% +model +by using the famous example uh brought + + align:start position:0% +by using the famous example uh brought + + + align:start position:0% +by using the famous example uh brought +up by adam smith + + align:start position:0% +up by adam smith + + + align:start position:0% +up by adam smith +adam smith is sort of considered the + + align:start position:0% +adam smith is sort of considered the + + + align:start position:0% +adam smith is sort of considered the +father of economics and paul sam's the + + align:start position:0% +father of economics and paul sam's the + + + align:start position:0% +father of economics and paul sam's the +father of modern economics adam smith + + align:start position:0% +father of modern economics adam smith + + + align:start position:0% +father of modern economics adam smith +the father of all economics + + align:start position:0% +the father of all economics + + + align:start position:0% +the father of all economics +his 1776 book the wealth of nations + + align:start position:0% +his 1776 book the wealth of nations + + + align:start position:0% +his 1776 book the wealth of nations +did an incredible job of actually laying + + align:start position:0% +did an incredible job of actually laying + + + align:start position:0% +did an incredible job of actually laying +out the entire core of the economics + + align:start position:0% +out the entire core of the economics + + + align:start position:0% +out the entire core of the economics +field + + align:start position:0% +field + + + align:start position:0% +field +uh no math just words but kind of he + + align:start position:0% +uh no math just words but kind of he + + + align:start position:0% +uh no math just words but kind of he +just nailed it + + align:start position:0% +just nailed it + + + align:start position:0% +just nailed it +and um he started one of his most famous + + align:start position:0% +and um he started one of his most famous + + + align:start position:0% +and um he started one of his most famous +examples was the water diamond paradox + + align:start position:0% +examples was the water diamond paradox + + + align:start position:0% +examples was the water diamond paradox +okay he said think about water and + + align:start position:0% +okay he said think about water and + + + align:start position:0% +okay he said think about water and +diamonds so start with water + + align:start position:0% +diamonds so start with water + + + align:start position:0% +diamonds so start with water +nothing is more important for life than + + align:start position:0% +nothing is more important for life than + + + align:start position:0% +nothing is more important for life than +water it's the building block of all of + + align:start position:0% +water it's the building block of all of + + + align:start position:0% +water it's the building block of all of +life + + align:start position:0% +life + + + align:start position:0% +life +okay even when we look for life on other + + align:start position:0% +okay even when we look for life on other + + + align:start position:0% +okay even when we look for life on other +planets we start by looking for water + + align:start position:0% +planets we start by looking for water + + + align:start position:0% +planets we start by looking for water +now think of diamonds one of the more + + align:start position:0% +now think of diamonds one of the more + + + align:start position:0% +now think of diamonds one of the more +frivolous things you can buy + + align:start position:0% +frivolous things you can buy + + + align:start position:0% +frivolous things you can buy +certainly irrelevant to uh leading a + + align:start position:0% +certainly irrelevant to uh leading a + + + align:start position:0% +certainly irrelevant to uh leading a +successful or happy or productive life + + align:start position:0% +successful or happy or productive life + + + align:start position:0% +successful or happy or productive life +or any life + + align:start position:0% +or any life + + + align:start position:0% +or any life +okay yet for most of us + + align:start position:0% +okay yet for most of us + + + align:start position:0% +okay yet for most of us +water's free and diamonds are super + + align:start position:0% +water's free and diamonds are super + + + align:start position:0% +water's free and diamonds are super +expensive okay + + align:start position:0% +expensive okay + + + align:start position:0% +expensive okay +how can this be adam smith asked well + + align:start position:0% +how can this be adam smith asked well + + + align:start position:0% +how can this be adam smith asked well +the answer he posed + + align:start position:0% +the answer he posed + + + align:start position:0% +the answer he posed +is that what i first described was just + + align:start position:0% +is that what i first described was just + + + align:start position:0% +is that what i first described was just +demand + + align:start position:0% +demand + + + align:start position:0% +demand +that is we demand lots of water we + + align:start position:0% +that is we demand lots of water we + + + align:start position:0% +that is we demand lots of water we +demand fewer diamonds + + align:start position:0% +demand fewer diamonds + + + align:start position:0% +demand fewer diamonds +but we have to match that with the + + align:start position:0% +but we have to match that with the + + + align:start position:0% +but we have to match that with the +concept of supply + + align:start position:0% +concept of supply + + + align:start position:0% +concept of supply +okay and the supply of water is almost + + align:start position:0% +okay and the supply of water is almost + + + align:start position:0% +okay and the supply of water is almost +infinite + + align:start position:0% +infinite + + + align:start position:0% +infinite +while the supply of diamonds maybe not + + align:start position:0% +while the supply of diamonds maybe not + + + align:start position:0% +while the supply of diamonds maybe not +naturally maybe it's through + + align:start position:0% +naturally maybe it's through + + + align:start position:0% +naturally maybe it's through +uh decisions of various businesses but + + align:start position:0% +uh decisions of various businesses but + + + align:start position:0% +uh decisions of various businesses but +it's somewhat limited + + align:start position:0% +it's somewhat limited + + + align:start position:0% +it's somewhat limited +okay so basically um + + align:start position:0% +okay so basically um + + + align:start position:0% +okay so basically um +what what he developed is what we call + + align:start position:0% +what what he developed is what we call + + + align:start position:0% +what what he developed is what we call +the supply and demand scissors + + align:start position:0% +the supply and demand scissors + + + align:start position:0% +the supply and demand scissors +that you can't just think of supply or + + align:start position:0% +that you can't just think of supply or + + + align:start position:0% +that you can't just think of supply or +demand in isolation you have to put them + + align:start position:0% +demand in isolation you have to put them + + + align:start position:0% +demand in isolation you have to put them +together + + align:start position:0% +together + + + align:start position:0% +together +if you want to explain the real world + + align:start position:0% +if you want to explain the real world + + + align:start position:0% +if you want to explain the real world +phenomena we see like the fact that + + align:start position:0% +phenomena we see like the fact that + + + align:start position:0% +phenomena we see like the fact that +water's cheap + + align:start position:0% +water's cheap + + + align:start position:0% +water's cheap +and uh diamonds are expensive so let's + + align:start position:0% +and uh diamonds are expensive so let's + + + align:start position:0% +and uh diamonds are expensive so let's +just talk + + align:start position:0% +just talk + + + align:start position:0% +just talk +let's talk about an example so there's + + align:start position:0% +let's talk about an example so there's + + + align:start position:0% +let's talk about an example so there's +one graph that was handed out in the + + align:start position:0% +one graph that was handed out in the + + + align:start position:0% +one graph that was handed out in the +back + + align:start position:0% +back + + + align:start position:0% +back +okay um which is let's talk about the + + align:start position:0% +okay um which is let's talk about the + + + align:start position:0% +okay um which is let's talk about the +market for roses + + align:start position:0% +market for roses + + + align:start position:0% +market for roses +okay um so + + align:start position:0% +okay um so + + + align:start position:0% +okay um so +in the market for roses we have + + align:start position:0% +in the market for roses we have + + + align:start position:0% +in the market for roses we have +a demand curve and a supply curve so + + align:start position:0% +a demand curve and a supply curve so + + + align:start position:0% +a demand curve and a supply curve so +what we have here this is the kind of xy + + align:start position:0% +what we have here this is the kind of xy + + + align:start position:0% +what we have here this is the kind of xy +graph we're going to look at all + + align:start position:0% +graph we're going to look at all + + + align:start position:0% +graph we're going to look at all +throughout the semester + + align:start position:0% +throughout the semester + + + align:start position:0% +throughout the semester +okay on the x-axis is the quantity of + + align:start position:0% +okay on the x-axis is the quantity of + + + align:start position:0% +okay on the x-axis is the quantity of +roses + + align:start position:0% +roses + + + align:start position:0% +roses +on the y-axis is the price of roses + + align:start position:0% +on the y-axis is the price of roses + + + align:start position:0% +on the y-axis is the price of roses +the blue downward sloping line is the + + align:start position:0% +the blue downward sloping line is the + + + align:start position:0% +the blue downward sloping line is the +demand curve + + align:start position:0% +demand curve + + + align:start position:0% +demand curve +now what i'm going to do here i'm just + + align:start position:0% +now what i'm going to do here i'm just + + + align:start position:0% +now what i'm going to do here i'm just +giving you an overview we're going to we + + align:start position:0% +giving you an overview we're going to we + + + align:start position:0% +giving you an overview we're going to we +are going over the next six + + align:start position:0% +are going over the next six + + + align:start position:0% +are going over the next six +like five or six lectures dive into + + align:start position:0% +like five or six lectures dive into + + + align:start position:0% +like five or six lectures dive into +where this demand curve comes from + + align:start position:0% +where this demand curve comes from + + + align:start position:0% +where this demand curve comes from +okay we'll go to first principles and + + align:start position:0% +okay we'll go to first principles and + + + align:start position:0% +okay we'll go to first principles and +build it back up but for now we know + + align:start position:0% +build it back up but for now we know + + + align:start position:0% +build it back up but for now we know +about demand curve + + align:start position:0% +about demand curve + + + align:start position:0% +about demand curve +is it simply represents the relationship + + align:start position:0% +is it simply represents the relationship + + + align:start position:0% +is it simply represents the relationship +between the price of a good and how much + + align:start position:0% +between the price of a good and how much + + + align:start position:0% +between the price of a good and how much +people want it + + align:start position:0% +people want it + + + align:start position:0% +people want it +therefore we assume it is downward + + align:start position:0% +therefore we assume it is downward + + + align:start position:0% +therefore we assume it is downward +sloping at higher prices people want + + align:start position:0% +sloping at higher prices people want + + + align:start position:0% +sloping at higher prices people want +less of the good + + align:start position:0% +less of the good + + + align:start position:0% +less of the good +and we'll just we'll derive where that + + align:start position:0% +and we'll just we'll derive where that + + + align:start position:0% +and we'll just we'll derive where that +comes from shortly starting next lecture + + align:start position:0% +comes from shortly starting next lecture + + + align:start position:0% +comes from shortly starting next lecture +but for now i think it's pretty + + align:start position:0% +but for now i think it's pretty + + + align:start position:0% +but for now i think it's pretty +intuitive that if the price of roads is + + align:start position:0% +intuitive that if the price of roads is + + + align:start position:0% +intuitive that if the price of roads is +higher + + align:start position:0% +higher + + + align:start position:0% +higher +people want fewer of them and that's why + + align:start position:0% +people want fewer of them and that's why + + + align:start position:0% +people want fewer of them and that's why +it's downward sloping + + align:start position:0% +it's downward sloping + + + align:start position:0% +it's downward sloping +okay that basically as the price of + + align:start position:0% +okay that basically as the price of + + + align:start position:0% +okay that basically as the price of +roses goes up + + align:start position:0% +roses goes up + + + align:start position:0% +roses goes up +people want fewer roses the yellow curve + + align:start position:0% +people want fewer roses the yellow curve + + + align:start position:0% +people want fewer roses the yellow curve +is the supply curve now after we've + + align:start position:0% +is the supply curve now after we've + + + align:start position:0% +is the supply curve now after we've +derived the demand curve we'll then go + + align:start position:0% +derived the demand curve we'll then go + + + align:start position:0% +derived the demand curve we'll then go +and spend about + + align:start position:0% +and spend about + + + align:start position:0% +and spend about +12 lectures to ride the supply curve + + align:start position:0% +12 lectures to ride the supply curve + + + align:start position:0% +12 lectures to ride the supply curve +that's a bit harder but once again we'll + + align:start position:0% +that's a bit harder but once again we'll + + + align:start position:0% +that's a bit harder but once again we'll +start from first principles and build it + + align:start position:0% +start from first principles and build it + + + align:start position:0% +start from first principles and build it +up + + align:start position:0% +up + + + align:start position:0% +up +for now you just need to know is that's + + align:start position:0% +for now you just need to know is that's + + + align:start position:0% +for now you just need to know is that's +how much firms are willing to supply + + align:start position:0% +how much firms are willing to supply + + + align:start position:0% +how much firms are willing to supply +given the price + + align:start position:0% +given the price + + + align:start position:0% +given the price +so basically as the price goes up firms + + align:start position:0% +so basically as the price goes up firms + + + align:start position:0% +so basically as the price goes up firms +want to produce more roses + + align:start position:0% +want to produce more roses + + + align:start position:0% +want to produce more roses +okay the higher price means you make + + align:start position:0% +okay the higher price means you make + + + align:start position:0% +okay the higher price means you make +more money so you want to produce more + + align:start position:0% +more money so you want to produce more + + + align:start position:0% +more money so you want to produce more +of them + + align:start position:0% +of them + + + align:start position:0% +of them +this is a slightly less intuitive than + + align:start position:0% +this is a slightly less intuitive than + + + align:start position:0% +this is a slightly less intuitive than +demand but we'll derive it and explain + + align:start position:0% +demand but we'll derive it and explain + + + align:start position:0% +demand but we'll derive it and explain +how it can be + + align:start position:0% +how it can be + + + align:start position:0% +how it can be +but for now just go with the basic + + align:start position:0% +but for now just go with the basic + + + align:start position:0% +but for now just go with the basic +intuition that if you're making + + align:start position:0% +intuition that if you're making + + + align:start position:0% +intuition that if you're making +something + + align:start position:0% +something + + + align:start position:0% +something +and you can sell in the market for a + + align:start position:0% +and you can sell in the market for a + + + align:start position:0% +and you can sell in the market for a +higher price you're going to want to + + align:start position:0% +higher price you're going to want to + + + align:start position:0% +higher price you're going to want to +make more of it + + align:start position:0% +make more of it + + + align:start position:0% +make more of it +okay and that leads the upward sloping + + align:start position:0% +okay and that leads the upward sloping + + + align:start position:0% +okay and that leads the upward sloping +supply curve + + align:start position:0% +supply curve + + + align:start position:0% +supply curve +where the points meet is the market + + align:start position:0% +where the points meet is the market + + + align:start position:0% +where the points meet is the market +equilibrium + + align:start position:0% +equilibrium + + + align:start position:0% +equilibrium +where supply and demand meets is the + + align:start position:0% +where supply and demand meets is the + + + align:start position:0% +where supply and demand meets is the +market equilibrium okay + + align:start position:0% +market equilibrium okay + + + align:start position:0% +market equilibrium okay +in the that is the point where both + + align:start position:0% +in the that is the point where both + + + align:start position:0% +in the that is the point where both +consumers + + align:start position:0% +consumers + + + align:start position:0% +consumers +and producers are happy to make a + + align:start position:0% +and producers are happy to make a + + + align:start position:0% +and producers are happy to make a +transaction + + align:start position:0% +transaction + + + align:start position:0% +transaction +consumers are happy because they are on + + align:start position:0% +consumers are happy because they are on + + + align:start position:0% +consumers are happy because they are on +their demand curve is the point + + align:start position:0% +their demand curve is the point + + + align:start position:0% +their demand curve is the point +600 is the point three dollars and six + + align:start position:0% +600 is the point three dollars and six + + + align:start position:0% +600 is the point three dollars and six +hundred roses + + align:start position:0% +hundred roses + + + align:start position:0% +hundred roses +that is they are willing to buy six + + align:start position:0% +that is they are willing to buy six + + + align:start position:0% +that is they are willing to buy six +hundred rows at three dollars + + align:start position:0% +hundred rows at three dollars + + + align:start position:0% +hundred rows at three dollars +okay producers are happy because on + + align:start position:0% +okay producers are happy because on + + + align:start position:0% +okay producers are happy because on +their supply curve is the same point + + align:start position:0% +their supply curve is the same point + + + align:start position:0% +their supply curve is the same point +they are willing to supply 600 rows of + + align:start position:0% +they are willing to supply 600 rows of + + + align:start position:0% +they are willing to supply 600 rows of +three dollars that is the one point + + align:start position:0% +three dollars that is the one point + + + align:start position:0% +three dollars that is the one point +where consumers are happy and producers + + align:start position:0% +where consumers are happy and producers + + + align:start position:0% +where consumers are happy and producers +are happy therefore it's the equilibrium + + align:start position:0% +are happy therefore it's the equilibrium + + + align:start position:0% +are happy therefore it's the equilibrium +highly non-technical but that's the + + align:start position:0% +highly non-technical but that's the + + + align:start position:0% +highly non-technical but that's the +basic intuition + + align:start position:0% +basic intuition + + + align:start position:0% +basic intuition +okay the point at which they're both + + align:start position:0% +okay the point at which they're both + + + align:start position:0% +okay the point at which they're both +willing to make that transaction the + + align:start position:0% +willing to make that transaction the + + + align:start position:0% +willing to make that transaction the +point that they're both satisfied with + + align:start position:0% +point that they're both satisfied with + + + align:start position:0% +point that they're both satisfied with +that transaction + + align:start position:0% +that transaction + + + align:start position:0% +that transaction +is the equilibrium which in this case is + + align:start position:0% +is the equilibrium which in this case is + + + align:start position:0% +is the equilibrium which in this case is +three dollars per rose and 600 roses + + align:start position:0% +three dollars per rose and 600 roses + + + align:start position:0% +three dollars per rose and 600 roses +now this raises lots of questions where + + align:start position:0% +now this raises lots of questions where + + + align:start position:0% +now this raises lots of questions where +do the curves come from + + align:start position:0% +do the curves come from + + + align:start position:0% +do the curves come from +how does equilibrium get achieved um why + + align:start position:0% +how does equilibrium get achieved um why + + + align:start position:0% +how does equilibrium get achieved um why +the heck do we give roses + + align:start position:0% +the heck do we give roses + + + align:start position:0% +the heck do we give roses +these are a bunch of questions we will + + align:start position:0% +these are a bunch of questions we will + + + align:start position:0% +these are a bunch of questions we will +um we will all + + align:start position:0% +um we will all + + + align:start position:0% +um we will all +we will come to all these questions over + + align:start position:0% +we will come to all these questions over + + + align:start position:0% +we will come to all these questions over +the next set of lectures + + align:start position:0% +the next set of lectures + + + align:start position:0% +the next set of lectures +but the basic thing is to understand + + align:start position:0% +but the basic thing is to understand + + + align:start position:0% +but the basic thing is to understand +this intuition of adam smith's supply + + align:start position:0% +this intuition of adam smith's supply + + + align:start position:0% +this intuition of adam smith's supply +and demand model + + align:start position:0% +and demand model + + + align:start position:0% +and demand model +okay questions about that + + align:start position:0% + + + + align:start position:0% + +okay now um this model + + align:start position:0% +okay now um this model + + + align:start position:0% +okay now um this model +also raises another important + + align:start position:0% +also raises another important + + + align:start position:0% +also raises another important +distinction that will focus on the + + align:start position:0% +distinction that will focus on the + + + align:start position:0% +distinction that will focus on the +semester and it's easy to get mixed up + + align:start position:0% +semester and it's easy to get mixed up + + + align:start position:0% +semester and it's easy to get mixed up +so i want you to if you're ever unclear + + align:start position:0% +so i want you to if you're ever unclear + + + align:start position:0% +so i want you to if you're ever unclear +i want you to ask me about it + + align:start position:0% +i want you to ask me about it + + + align:start position:0% +i want you to ask me about it +and that's distinguishing between + + align:start position:0% +and that's distinguishing between + + + align:start position:0% +and that's distinguishing between +positive + + align:start position:0% + + + + align:start position:0% + +positive versus normative + + align:start position:0% + + + + align:start position:0% + +analyses positive versus normative + + align:start position:0% +analyses positive versus normative + + + align:start position:0% +analyses positive versus normative +positive analysis is the study of the + + align:start position:0% +positive analysis is the study of the + + + align:start position:0% +positive analysis is the study of the +way things + + align:start position:0% +way things + + + align:start position:0% +way things +are while normative analyses are this is + + align:start position:0% +are while normative analyses are this is + + + align:start position:0% +are while normative analyses are this is +the study of the way things should be + + align:start position:0% +the study of the way things should be + + + align:start position:0% +the study of the way things should be +okay positive analysis to study the way + + align:start position:0% +okay positive analysis to study the way + + + align:start position:0% +okay positive analysis to study the way +things are while normative analysis + + align:start position:0% +things are while normative analysis + + + align:start position:0% +things are while normative analysis +is to study the way things should be + + align:start position:0% + + + + align:start position:0% + +let me give you a great example which is + + align:start position:0% +let me give you a great example which is + + + align:start position:0% +let me give you a great example which is +uh + + align:start position:0% +uh + + + align:start position:0% +uh +ebay auctions okay + + align:start position:0% +ebay auctions okay + + + align:start position:0% +ebay auctions okay +auctions are a terrific example they're + + align:start position:0% +auctions are a terrific example they're + + + align:start position:0% +auctions are a terrific example they're +like the textbook example of the + + align:start position:0% +like the textbook example of the + + + align:start position:0% +like the textbook example of the +competitive market + + align:start position:0% +competitive market + + + align:start position:0% +competitive market +you can see it in your head demand comes + + align:start position:0% +you can see it in your head demand comes + + + align:start position:0% +you can see it in your head demand comes +a bunch of people going on and bidding + + align:start position:0% +a bunch of people going on and bidding + + + align:start position:0% +a bunch of people going on and bidding +people who want it more bid more so you + + align:start position:0% +people who want it more bid more so you + + + align:start position:0% +people who want it more bid more so you +actually get a demand curve + + align:start position:0% +actually get a demand curve + + + align:start position:0% +actually get a demand curve +the higher the price the fewer people + + align:start position:0% +the higher the price the fewer people + + + align:start position:0% +the higher the price the fewer people +are getting you're getting to bid + + align:start position:0% +are getting you're getting to bid + + + align:start position:0% +are getting you're getting to bid +supply is how much how many units of it + + align:start position:0% +supply is how much how many units of it + + + align:start position:0% +supply is how much how many units of it +are for sale on ebay + + align:start position:0% +are for sale on ebay + + + align:start position:0% +are for sale on ebay +you you bid until those two meet and + + align:start position:0% +you you bid until those two meet and + + + align:start position:0% +you you bid until those two meet and +then you have + + align:start position:0% +then you have + + + align:start position:0% +then you have +a market equilibrium at that bidded + + align:start position:0% +a market equilibrium at that bidded + + + align:start position:0% +a market equilibrium at that bidded +price + + align:start position:0% +price + + + align:start position:0% +price +okay now one um + + align:start position:0% +okay now one um + + + align:start position:0% +okay now one um +one example of an ebay auction that got + + align:start position:0% +one example of an ebay auction that got + + + align:start position:0% +one example of an ebay auction that got +a lot of attention a number of years ago + + align:start position:0% +a lot of attention a number of years ago + + + align:start position:0% +a lot of attention a number of years ago +early in the days of ebay was someone + + align:start position:0% +early in the days of ebay was someone + + + align:start position:0% +early in the days of ebay was someone +offered their kidney for auction + + align:start position:0% +offered their kidney for auction + + + align:start position:0% +offered their kidney for auction +they said look i got two kidneys you + + align:start position:0% +they said look i got two kidneys you + + + align:start position:0% +they said look i got two kidneys you +only need one to live there people out + + align:start position:0% +only need one to live there people out + + + align:start position:0% +only need one to live there people out +there need a kidney + + align:start position:0% +there need a kidney + + + align:start position:0% +there need a kidney +i'm putting my kidney on ebay for + + align:start position:0% +i'm putting my kidney on ebay for + + + align:start position:0% +i'm putting my kidney on ebay for +auction um + + align:start position:0% +auction um + + + align:start position:0% +auction um +and what happened bidding went nuts it + + align:start position:0% +and what happened bidding went nuts it + + + align:start position:0% +and what happened bidding went nuts it +started at 25 000 + + align:start position:0% +started at 25 000 + + + align:start position:0% +started at 25 000 +it climbed to 5 million before the + + align:start position:0% +it climbed to 5 million before the + + + align:start position:0% +it climbed to 5 million before the +auction was shut down and ebay decided + + align:start position:0% +auction was shut down and ebay decided + + + align:start position:0% +auction was shut down and ebay decided +they wouldn't + + align:start position:0% +they wouldn't + + + align:start position:0% +they wouldn't +allow you to sell your body on ebay + + align:start position:0% +allow you to sell your body on ebay + + + align:start position:0% +allow you to sell your body on ebay +bodily parts on ebay okay + + align:start position:0% +bodily parts on ebay okay + + + align:start position:0% +bodily parts on ebay okay +so this raises two questions + + align:start position:0% +so this raises two questions + + + align:start position:0% +so this raises two questions +the first is the positive question why + + align:start position:0% +the first is the positive question why + + + align:start position:0% +the first is the positive question why +did the price go so high + + align:start position:0% +did the price go so high + + + align:start position:0% +did the price go so high +so what's the answer to that what's the + + align:start position:0% +so what's the answer to that what's the + + + align:start position:0% +so what's the answer to that what's the +answer to the positive question + + align:start position:0% +answer to the positive question + + + align:start position:0% +answer to the positive question +okay let's look good but let's let's + + align:start position:0% +okay let's look good but let's let's + + + align:start position:0% +okay let's look good but let's let's +raise hands and + + align:start position:0% +raise hands and + + + align:start position:0% +raise hands and +give ants that's part of it yeah + + align:start position:0% +give ants that's part of it yeah + + + align:start position:0% +give ants that's part of it yeah +supply high demand demand is incredibly + + align:start position:0% +supply high demand demand is incredibly + + + align:start position:0% +supply high demand demand is incredibly +high because i die without it + + align:start position:0% +high because i die without it + + + align:start position:0% +high because i die without it +supply is low because like not a lot of + + align:start position:0% +supply is low because like not a lot of + + + align:start position:0% +supply is low because like not a lot of +us are willing to sell their kitties on + + align:start position:0% +us are willing to sell their kitties on + + + align:start position:0% +us are willing to sell their kitties on +ebay + + align:start position:0% +ebay + + + align:start position:0% +ebay +okay so low supply high demand led to a + + align:start position:0% +okay so low supply high demand led to a + + + align:start position:0% +okay so low supply high demand led to a +high price + + align:start position:0% +high price + + + align:start position:0% +high price +adam smith at work that's the positive + + align:start position:0% +adam smith at work that's the positive + + + align:start position:0% +adam smith at work that's the positive +analysis + + align:start position:0% +analysis + + + align:start position:0% +analysis +okay but this raises the north but then + + align:start position:0% +okay but this raises the north but then + + + align:start position:0% +okay but this raises the north but then +there's the normative question + + align:start position:0% +there's the normative question + + + align:start position:0% +there's the normative question +which is should you be allowed to sell + + align:start position:0% +which is should you be allowed to sell + + + align:start position:0% +which is should you be allowed to sell +your kidneys on ebay + + align:start position:0% +your kidneys on ebay + + + align:start position:0% +your kidneys on ebay +that's the normative question the + + align:start position:0% +that's the normative question the + + + align:start position:0% +that's the normative question the +positive question is what happens if you + + align:start position:0% +positive question is what happens if you + + + align:start position:0% +positive question is what happens if you +do + + align:start position:0% +do + + + align:start position:0% +do +the normative question is should you now + + align:start position:0% +the normative question is should you now + + + align:start position:0% +the normative question is should you now +the standard economics answer to start + + align:start position:0% +the standard economics answer to start + + + align:start position:0% +the standard economics answer to start +would be + + align:start position:0% +would be + + + align:start position:0% +would be +of course you should we're in a world + + align:start position:0% +of course you should we're in a world + + + align:start position:0% +of course you should we're in a world +where + + align:start position:0% +where + + + align:start position:0% +where +thousands of people die every year + + align:start position:0% +thousands of people die every year + + + align:start position:0% +thousands of people die every year +because there's a waiting list for a + + align:start position:0% +because there's a waiting list for a + + + align:start position:0% +because there's a waiting list for a +kidney transplant + + align:start position:0% +kidney transplant + + + align:start position:0% +kidney transplant +okay and these are people who would + + align:start position:0% +okay and these are people who would + + + align:start position:0% +okay and these are people who would +happily pay a lot of money to stay alive + + align:start position:0% +happily pay a lot of money to stay alive + + + align:start position:0% +happily pay a lot of money to stay alive +i presume + + align:start position:0% +i presume + + + align:start position:0% +i presume +okay meanwhile there's + + align:start position:0% +okay meanwhile there's + + + align:start position:0% +okay meanwhile there's +hundreds of millions of people walking + + align:start position:0% +hundreds of millions of people walking + + + align:start position:0% +hundreds of millions of people walking +around with two kidneys + + align:start position:0% +around with two kidneys + + + align:start position:0% +around with two kidneys +who only need one and many of these + + align:start position:0% +who only need one and many of these + + + align:start position:0% +who only need one and many of these +people + + align:start position:0% +people + + + align:start position:0% +people +are poor and lives could be changed by + + align:start position:0% +are poor and lives could be changed by + + + align:start position:0% +are poor and lives could be changed by +being paid a million dollars for their + + align:start position:0% +being paid a million dollars for their + + + align:start position:0% +being paid a million dollars for their +kidney + + align:start position:0% +kidney + + + align:start position:0% +kidney +and might be happy to take the risk that + + align:start position:0% +and might be happy to take the risk that + + + align:start position:0% +and might be happy to take the risk that +their other that one kidney will be fine + + align:start position:0% +their other that one kidney will be fine + + + align:start position:0% +their other that one kidney will be fine +as it is for most everyone for most of + + align:start position:0% +as it is for most everyone for most of + + + align:start position:0% +as it is for most everyone for most of +their life + + align:start position:0% +their life + + + align:start position:0% +their life +in return for having the life-changing + + align:start position:0% +in return for having the life-changing + + + align:start position:0% +in return for having the life-changing +payment from a stranger + + align:start position:0% +payment from a stranger + + + align:start position:0% +payment from a stranger +so economists say look here's a + + align:start position:0% +so economists say look here's a + + + align:start position:0% +so economists say look here's a +transaction to make both parties better + + align:start position:0% +transaction to make both parties better + + + align:start position:0% +transaction to make both parties better +off + + align:start position:0% +off + + + align:start position:0% +off +the person who gets the kidney gets to + + align:start position:0% +the person who gets the kidney gets to + + + align:start position:0% +the person who gets the kidney gets to +stay alive and they're what they are + + align:start position:0% +stay alive and they're what they are + + + align:start position:0% +stay alive and they're what they are +willing to pay a huge amount for that + + align:start position:0% +willing to pay a huge amount for that + + + align:start position:0% +willing to pay a huge amount for that +the person who sells the kidney in most + + align:start position:0% +the person who sells the kidney in most + + + align:start position:0% +the person who sells the kidney in most +probability is + + align:start position:0% +probability is + + + align:start position:0% +probability is +fine because almost all of us can make + + align:start position:0% +fine because almost all of us can make + + + align:start position:0% +fine because almost all of us can make +it through life fine with one kidney + + align:start position:0% +it through life fine with one kidney + + + align:start position:0% +it through life fine with one kidney +and get a life-changing amount of money + + align:start position:0% +and get a life-changing amount of money + + + align:start position:0% +and get a life-changing amount of money +that could allow them to pursue their + + align:start position:0% +that could allow them to pursue their + + + align:start position:0% +that could allow them to pursue their +dreams in various ways + + align:start position:0% +dreams in various ways + + + align:start position:0% +dreams in various ways +okay so that's the standard argument + + align:start position:0% +okay so that's the standard argument + + + align:start position:0% +okay so that's the standard argument +would be + + align:start position:0% +would be + + + align:start position:0% +would be +yeah you should be able to sell your + + align:start position:0% +yeah you should be able to sell your + + + align:start position:0% +yeah you should be able to sell your +kidneys on ebay + + align:start position:0% +kidneys on ebay + + + align:start position:0% +kidneys on ebay +okay so the question is why not + + align:start position:0% +okay so the question is why not + + + align:start position:0% +okay so the question is why not +why would we want to stop this + + align:start position:0% +why would we want to stop this + + + align:start position:0% +why would we want to stop this +transaction what are the counter + + align:start position:0% +transaction what are the counter + + + align:start position:0% +transaction what are the counter +arguments + + align:start position:0% +arguments + + + align:start position:0% +arguments +to that let's raise our rates yeah + + align:start position:0% +to that let's raise our rates yeah + + + align:start position:0% +to that let's raise our rates yeah +like i i think maybe the issue was like + + align:start position:0% +like i i think maybe the issue was like + + + align:start position:0% +like i i think maybe the issue was like +because it was ebay there's like no way + + align:start position:0% +because it was ebay there's like no way + + + align:start position:0% +because it was ebay there's like no way +to regulate it + + align:start position:0% +to regulate it + + + align:start position:0% +to regulate it +or like you don't like necessarily know + + align:start position:0% +or like you don't like necessarily know + + + align:start position:0% +or like you don't like necessarily know +like people could be like selling fake + + align:start position:0% +like people could be like selling fake + + + align:start position:0% +like people could be like selling fake +kidneys per se + + align:start position:0% +kidneys per se + + + align:start position:0% +kidneys per se +right so the first type of problem comes + + align:start position:0% +right so the first type of problem comes + + + align:start position:0% +right so the first type of problem comes +out of the category we call + + align:start position:0% +out of the category we call + + + align:start position:0% +out of the category we call +market failures + + align:start position:0% + + + + align:start position:0% + +market failures are reasons why the + + align:start position:0% +market failures are reasons why the + + + align:start position:0% +market failures are reasons why the +market doesn't work in the wonderful way + + align:start position:0% +market doesn't work in the wonderful way + + + align:start position:0% +market doesn't work in the wonderful way +economists like to think it should + + align:start position:0% +economists like to think it should + + + align:start position:0% +economists like to think it should +so for example this answer puts up that + + align:start position:0% +so for example this answer puts up that + + + align:start position:0% +so for example this answer puts up that +could be the problem + + align:start position:0% +could be the problem + + + align:start position:0% +could be the problem +of um fraud + + align:start position:0% + + + + align:start position:0% + +okay people might not be able to tell + + align:start position:0% +okay people might not be able to tell + + + align:start position:0% +okay people might not be able to tell +if they're getting a legit kidney or not + + align:start position:0% +if they're getting a legit kidney or not + + + align:start position:0% +if they're getting a legit kidney or not +okay + + align:start position:0% +okay + + + align:start position:0% +okay +there could be the example of imperfect + + align:start position:0% +there could be the example of imperfect + + + align:start position:0% +there could be the example of imperfect +information + + align:start position:0% + + + + align:start position:0% + +do you know what the odds are that you + + align:start position:0% +do you know what the odds are that you + + + align:start position:0% +do you know what the odds are that you +can spend the rest of your life with + + align:start position:0% +can spend the rest of your life with + + + align:start position:0% +can spend the rest of your life with +only one kidney + + align:start position:0% +only one kidney + + + align:start position:0% +only one kidney +i don't either okay we ought to know + + align:start position:0% +i don't either okay we ought to know + + + align:start position:0% +i don't either okay we ought to know +that + + align:start position:0% +that + + + align:start position:0% +that +before we start selling our kidneys okay + + align:start position:0% +before we start selling our kidneys okay + + + align:start position:0% +before we start selling our kidneys okay +there could be a perfect information + + align:start position:0% +there could be a perfect information + + + align:start position:0% +there could be a perfect information +okay these are the kinds of this is one + + align:start position:0% +okay these are the kinds of this is one + + + align:start position:0% +okay these are the kinds of this is one +type of problem which is the market + + align:start position:0% +type of problem which is the market + + + align:start position:0% +type of problem which is the market +maybe the market may fail + + align:start position:0% + + + + align:start position:0% + +like okay current system also helps + + align:start position:0% +like okay current system also helps + + + align:start position:0% +like okay current system also helps +people who are + + align:start position:0% +people who are + + + align:start position:0% +people who are +poor and have failed kidney um + + align:start position:0% +poor and have failed kidney um + + + align:start position:0% +poor and have failed kidney um +and which would be which are people to + + align:start position:0% +and which would be which are people to + + + align:start position:0% +and which would be which are people to +be completely screwed underwater + + align:start position:0% +be completely screwed underwater + + + align:start position:0% +be completely screwed underwater +the set a second problem is what we call + + align:start position:0% +the set a second problem is what we call + + + align:start position:0% +the set a second problem is what we call +equity + + align:start position:0% +equity + + + align:start position:0% +equity +or fairness + + align:start position:0% + + + + align:start position:0% + +equity or fairness which is + + align:start position:0% +equity or fairness which is + + + align:start position:0% +equity or fairness which is +we would end up with a world where only + + align:start position:0% +we would end up with a world where only + + + align:start position:0% +we would end up with a world where only +rich people would get kidneys + + align:start position:0% +rich people would get kidneys + + + align:start position:0% +rich people would get kidneys +okay currently there's a bunch of + + align:start position:0% +okay currently there's a bunch of + + + align:start position:0% +okay currently there's a bunch of +voluntary donors and people who are in + + align:start position:0% +voluntary donors and people who are in + + + align:start position:0% +voluntary donors and people who are in +accidents who have kidneys left over + + align:start position:0% +accidents who have kidneys left over + + + align:start position:0% +accidents who have kidneys left over +okay and those go to a people on the + + align:start position:0% +okay and those go to a people on the + + + align:start position:0% +okay and those go to a people on the +base of where they are in a waiting list + + align:start position:0% +base of where they are in a waiting list + + + align:start position:0% +base of where they are in a waiting list +actually a prioritized waiting list it's + + align:start position:0% +actually a prioritized waiting list it's + + + align:start position:0% +actually a prioritized waiting list it's +kind of a cool + + align:start position:0% +kind of a cool + + + align:start position:0% +kind of a cool +one of my colleagues nikhil agarwal if + + align:start position:0% +one of my colleagues nikhil agarwal if + + + align:start position:0% +one of my colleagues nikhil agarwal if +you think about + + align:start position:0% +you think about + + + align:start position:0% +you think about +i'll talk a lot this semester about the + + align:start position:0% +i'll talk a lot this semester about the + + + align:start position:0% +i'll talk a lot this semester about the +imperialistic view of economics all the + + align:start position:0% +imperialistic view of economics all the + + + align:start position:0% +imperialistic view of economics all the +cool things we can study + + align:start position:0% +cool things we can study + + + align:start position:0% +cool things we can study +so he actually uses economic models to + + align:start position:0% +so he actually uses economic models to + + + align:start position:0% +so he actually uses economic models to +study the optimal way to allocate organs + + align:start position:0% +study the optimal way to allocate organs + + + align:start position:0% +study the optimal way to allocate organs +to individuals right now it's just done + + align:start position:0% +to individuals right now it's just done + + + align:start position:0% +to individuals right now it's just done +based on a waiting list + + align:start position:0% +based on a waiting list + + + align:start position:0% +based on a waiting list +but but it may be that someone further + + align:start position:0% +but but it may be that someone further + + + align:start position:0% +but but it may be that someone further +down the waiting list needs it more than + + align:start position:0% +down the waiting list needs it more than + + + align:start position:0% +down the waiting list needs it more than +so and higher up the waiting list + + align:start position:0% +so and higher up the waiting list + + + align:start position:0% +so and higher up the waiting list +because they're more critical or + + align:start position:0% +because they're more critical or + + + align:start position:0% +because they're more critical or +whatever so there's various + + align:start position:0% +whatever so there's various + + + align:start position:0% +whatever so there's various +optimum ways to allocate but certainly + + align:start position:0% +optimum ways to allocate but certainly + + + align:start position:0% +optimum ways to allocate but certainly +although it allocate wouldn't be the + + align:start position:0% +although it allocate wouldn't be the + + + align:start position:0% +although it allocate wouldn't be the +rich guy gets it first + + align:start position:0% +rich guy gets it first + + + align:start position:0% +rich guy gets it first +that would be unlikely to be what + + align:start position:0% +that would be unlikely to be what + + + align:start position:0% +that would be unlikely to be what +society would necessarily want + + align:start position:0% +society would necessarily want + + + align:start position:0% +society would necessarily want +so there's an equity concern with that + + align:start position:0% +so there's an equity concern with that + + + align:start position:0% +so there's an equity concern with that +what else + + align:start position:0% +what else + + + align:start position:0% +what else +what other sorts yeah really + + align:start position:0% +what other sorts yeah really + + + align:start position:0% +what other sorts yeah really +since you know you can make money off of + + align:start position:0% +since you know you can make money off of + + + align:start position:0% +since you know you can make money off of +selling kidneys and you take advantage + + align:start position:0% +selling kidneys and you take advantage + + + align:start position:0% +selling kidneys and you take advantage +of people + + align:start position:0% +of people + + + align:start position:0% +of people +and it's very bad black market for + + align:start position:0% +and it's very bad black market for + + + align:start position:0% +and it's very bad black market for +kidneys + + align:start position:0% +kidneys + + + align:start position:0% +kidneys +right so there's sort of a third it's + + align:start position:0% +right so there's sort of a third it's + + + align:start position:0% +right so there's sort of a third it's +related to fraud but there's sort of a + + align:start position:0% +related to fraud but there's sort of a + + + align:start position:0% +related to fraud but there's sort of a +third class of failures + + align:start position:0% +third class of failures + + + align:start position:0% +third class of failures +that gets into the question about mis + + align:start position:0% +that gets into the question about mis + + + align:start position:0% +that gets into the question about mis +behavioral economics we talked that was + + align:start position:0% +behavioral economics we talked that was + + + align:start position:0% +behavioral economics we talked that was +raised earlier + + align:start position:0% +raised earlier + + + align:start position:0% +raised earlier +which we could just call so failing + + align:start position:0% +which we could just call so failing + + + align:start position:0% +which we could just call so failing +behavioral + + align:start position:0% +behavioral + + + align:start position:0% +behavioral +it's called behavioral economics for one + + align:start position:0% +it's called behavioral economics for one + + + align:start position:0% +it's called behavioral economics for one +of a better term which is essentially + + align:start position:0% +of a better term which is essentially + + + align:start position:0% +of a better term which is essentially +people don't always make decisions in + + align:start position:0% +people don't always make decisions in + + + align:start position:0% +people don't always make decisions in +the perfectly rational logical way we + + align:start position:0% +the perfectly rational logical way we + + + align:start position:0% +the perfectly rational logical way we +will model them as doing so this + + align:start position:0% +will model them as doing so this + + + align:start position:0% +will model them as doing so this +semester + + align:start position:0% +semester + + + align:start position:0% +semester +people make mistakes that's a word we + + align:start position:0% +people make mistakes that's a word we + + + align:start position:0% +people make mistakes that's a word we +hate using economics we hate saying + + align:start position:0% +hate using economics we hate saying + + + align:start position:0% +hate using economics we hate saying +mistakes ooh boo + + align:start position:0% +mistakes ooh boo + + + align:start position:0% +mistakes ooh boo +mistakes nobody makes mistakes we're all + + align:start position:0% +mistakes nobody makes mistakes we're all + + + align:start position:0% +mistakes nobody makes mistakes we're all +perfect little economic beings but we + + align:start position:0% +perfect little economic beings but we + + + align:start position:0% +perfect little economic beings but we +know that's not true + + align:start position:0% +know that's not true + + + align:start position:0% +know that's not true +increasingly over the past several + + align:start position:0% +increasingly over the past several + + + align:start position:0% +increasingly over the past several +decades economists have started + + align:start position:0% +decades economists have started + + + align:start position:0% +decades economists have started +incorporating insights from psychology + + align:start position:0% +incorporating insights from psychology + + + align:start position:0% +incorporating insights from psychology +into our models to not just say people + + align:start position:0% +into our models to not just say people + + + align:start position:0% +into our models to not just say people +make mistakes that's a lackadaisical but + + align:start position:0% +make mistakes that's a lackadaisical but + + + align:start position:0% +make mistakes that's a lackadaisical but +to rigorously model the nature of those + + align:start position:0% +to rigorously model the nature of those + + + align:start position:0% +to rigorously model the nature of those +mistakes + + align:start position:0% +mistakes + + + align:start position:0% +mistakes +and understand how mistakes can actually + + align:start position:0% +and understand how mistakes can actually + + + align:start position:0% +and understand how mistakes can actually +happen + + align:start position:0% +happen + + + align:start position:0% +happen +due to virus cognitive biases and other + + align:start position:0% +due to virus cognitive biases and other + + + align:start position:0% +due to virus cognitive biases and other +things in this world you can imagine + + align:start position:0% +things in this world you can imagine + + + align:start position:0% +things in this world you can imagine +people could + + align:start position:0% +people could + + + align:start position:0% +people could +make mistakes they could be they could + + align:start position:0% +make mistakes they could be they could + + + align:start position:0% +make mistakes they could be they could +not really sit down and quite understand + + align:start position:0% +not really sit down and quite understand + + + align:start position:0% +not really sit down and quite understand +what they're doing + + align:start position:0% +what they're doing + + + align:start position:0% +what they're doing +and they could have selling their kidney + + align:start position:0% +and they could have selling their kidney + + + align:start position:0% +and they could have selling their kidney +when it's really not in their own + + align:start position:0% +when it's really not in their own + + + align:start position:0% +when it's really not in their own +long-term interest + + align:start position:0% +long-term interest + + + align:start position:0% +long-term interest +yeah example be like if there's like a + + align:start position:0% +yeah example be like if there's like a + + + align:start position:0% +yeah example be like if there's like a +family that's like an extreme poverty + + align:start position:0% +family that's like an extreme poverty + + + align:start position:0% +family that's like an extreme poverty +like + + align:start position:0% +like + + + align:start position:0% +like +even though they only have one kidney + + align:start position:0% +even though they only have one kidney + + + align:start position:0% +even though they only have one kidney +they might sell the other one just to + + align:start position:0% +they might sell the other one just to + + + align:start position:0% +they might sell the other one just to +give them money for the family per se + + align:start position:0% +give them money for the family per se + + + align:start position:0% +give them money for the family per se +well i mean in subsets that would be + + align:start position:0% +well i mean in subsets that would be + + + align:start position:0% +well i mean in subsets that would be +once again + + align:start position:0% +once again + + + align:start position:0% +once again +in a if we took this factor out we took + + align:start position:0% +in a if we took this factor out we took + + + align:start position:0% +in a if we took this factor out we took +if we took + + align:start position:0% +if we took + + + align:start position:0% +if we took +if we took if the market worked well + + align:start position:0% +if we took if the market worked well + + + align:start position:0% +if we took if the market worked well +there's no behavioral effects we'd say + + align:start position:0% +there's no behavioral effects we'd say + + + align:start position:0% +there's no behavioral effects we'd say +well you know what that's their decision + + align:start position:0% +well you know what that's their decision + + + align:start position:0% +well you know what that's their decision +you know if they otherwise they starve + + align:start position:0% +you know if they otherwise they starve + + + align:start position:0% +you know if they otherwise they starve +who are you to say + + align:start position:0% +who are you to say + + + align:start position:0% +who are you to say +okay but once you choose this say well + + align:start position:0% +okay but once you choose this say well + + + align:start position:0% +okay but once you choose this say well +wait a second maybe they're not + + align:start position:0% +wait a second maybe they're not + + + align:start position:0% +wait a second maybe they're not +evaluating the trade-offs correctly + + align:start position:0% +evaluating the trade-offs correctly + + + align:start position:0% +evaluating the trade-offs correctly +even if there's no fraud even if there's + + align:start position:0% +even if there's no fraud even if there's + + + align:start position:0% +even if there's no fraud even if there's +perfect information they may not know + + align:start position:0% +perfect information they may not know + + + align:start position:0% +perfect information they may not know +how to process that information + + align:start position:0% +how to process that information + + + align:start position:0% +how to process that information +correctly + + align:start position:0% +correctly + + + align:start position:0% +correctly +okay but that is not standard economics + + align:start position:0% +okay but that is not standard economics + + + align:start position:0% +okay but that is not standard economics +that's not what we'll spend a lot of + + align:start position:0% +that's not what we'll spend a lot of + + + align:start position:0% +that's not what we'll spend a lot of +time in the semester but it's obviously + + align:start position:0% +time in the semester but it's obviously + + + align:start position:0% +time in the semester but it's obviously +realistic + + align:start position:0% +realistic + + + align:start position:0% +realistic +okay so those are a bunch of good + + align:start position:0% +okay so those are a bunch of good + + + align:start position:0% +okay so those are a bunch of good +comments great comments + + align:start position:0% +comments great comments + + + align:start position:0% +comments great comments +and that yeah they're also an inelastic + + align:start position:0% +and that yeah they're also an inelastic + + + align:start position:0% +and that yeah they're also an inelastic +demand + + align:start position:0% +demand + + + align:start position:0% +demand +such that people will always need + + align:start position:0% +such that people will always need + + + align:start position:0% +such that people will always need +kidneys that won't turn out to be a pro + + align:start position:0% +kidneys that won't turn out to be a pro + + + align:start position:0% +kidneys that won't turn out to be a pro +that doesn't turn out to be a problem + + align:start position:0% +that doesn't turn out to be a problem + + + align:start position:0% +that doesn't turn out to be a problem +okay we'll come back that's a great + + align:start position:0% +okay we'll come back that's a great + + + align:start position:0% +okay we'll come back that's a great +comeback though we talk about the shape + + align:start position:0% +comeback though we talk about the shape + + + align:start position:0% +comeback though we talk about the shape +and demand curves + + align:start position:0% +and demand curves + + + align:start position:0% +and demand curves +if you want to return to that question a + + align:start position:0% +if you want to return to that question a + + + align:start position:0% +if you want to return to that question a +few lectures but that doesn't actually + + align:start position:0% +few lectures but that doesn't actually + + + align:start position:0% +few lectures but that doesn't actually +cause a problem + + align:start position:0% +cause a problem + + + align:start position:0% +cause a problem +it's just that's more of a positive + + align:start position:0% +it's just that's more of a positive + + + align:start position:0% +it's just that's more of a positive +thing about why the price is so high but + + align:start position:0% +thing about why the price is so high but + + + align:start position:0% +thing about why the price is so high but +it's not a normative issue about whether + + align:start position:0% +it's not a normative issue about whether + + + align:start position:0% +it's not a normative issue about whether +you should allow it or not + + align:start position:0% +you should allow it or not + + + align:start position:0% +you should allow it or not +okay so basically these are exactly + + align:start position:0% +okay so basically these are exactly + + + align:start position:0% +okay so basically these are exactly +this isn't to me honestly i spend my + + align:start position:0% +this isn't to me honestly i spend my + + + align:start position:0% +this isn't to me honestly i spend my +life thinking a lot about these things i + + align:start position:0% +life thinking a lot about these things i + + + align:start position:0% +life thinking a lot about these things i +think these are really interesting + + align:start position:0% +think these are really interesting + + + align:start position:0% +think these are really interesting +issues + + align:start position:0% +issues + + + align:start position:0% +issues +but you can't get to the nordic issues + + align:start position:0% +but you can't get to the nordic issues + + + align:start position:0% +but you can't get to the nordic issues +without the positive analysis + + align:start position:0% +without the positive analysis + + + align:start position:0% +without the positive analysis +usually the positive analysis to + + align:start position:0% +usually the positive analysis to + + + align:start position:0% +usually the positive analysis to +understand the economic framework + + align:start position:0% +understand the economic framework + + + align:start position:0% +understand the economic framework +before you start jumping you're drawing + + align:start position:0% +before you start jumping you're drawing + + + align:start position:0% +before you start jumping you're drawing +conclusions that's no fun we all want to + + align:start position:0% +conclusions that's no fun we all want to + + + align:start position:0% +conclusions that's no fun we all want to +jump to draw conclusions + + align:start position:0% +jump to draw conclusions + + + align:start position:0% +jump to draw conclusions +saying this should happen it shouldn't + + align:start position:0% +saying this should happen it shouldn't + + + align:start position:0% +saying this should happen it shouldn't +happen you can't do that we have to be + + align:start position:0% +happen you can't do that we have to be + + + align:start position:0% +happen you can't do that we have to be +disciplined + + align:start position:0% +disciplined + + + align:start position:0% +disciplined +we have to start with the fundamental + + align:start position:0% +we have to start with the fundamental + + + align:start position:0% +we have to start with the fundamental +economic framework + + align:start position:0% +economic framework + + + align:start position:0% +economic framework +okay and basically the bottom line you + + align:start position:0% +okay and basically the bottom line you + + + align:start position:0% +okay and basically the bottom line you +know i said i'll teach this course with + + align:start position:0% +know i said i'll teach this course with + + + align:start position:0% +know i said i'll teach this course with +a policy bent + + align:start position:0% +a policy bent + + + align:start position:0% +a policy bent +but you have to recognize that economics + + align:start position:0% +but you have to recognize that economics + + + align:start position:0% +but you have to recognize that economics +at its core is a right-wing science + + align:start position:0% +at its core is a right-wing science + + + align:start position:0% +at its core is a right-wing science +economics at its core is all about how + + align:start position:0% +economics at its core is all about how + + + align:start position:0% +economics at its core is all about how +the market knows best + + align:start position:0% +the market knows best + + + align:start position:0% +the market knows best +okay and that basically governments only + + align:start position:0% +okay and that basically governments only + + + align:start position:0% +okay and that basically governments only +mess things up + + align:start position:0% +mess things up + + + align:start position:0% +mess things up +that's sort of the basic a lot of what + + align:start position:0% +that's sort of the basic a lot of what + + + align:start position:0% +that's sort of the basic a lot of what +we'll learn this semester as semester + + align:start position:0% +we'll learn this semester as semester + + + align:start position:0% +we'll learn this semester as semester +goes on and we'll talk about what's + + align:start position:0% +goes on and we'll talk about what's + + + align:start position:0% +goes on and we'll talk about what's +wrong with that view + + align:start position:0% +wrong with that view + + + align:start position:0% +wrong with that view +and how governments can improve things + + align:start position:0% +and how governments can improve things + + + align:start position:0% +and how governments can improve things +indeed i teach a whole course about the + + align:start position:0% +indeed i teach a whole course about the + + + align:start position:0% +indeed i teach a whole course about the +proper role of government + + align:start position:0% +proper role of government + + + align:start position:0% +proper role of government +economy but the standard of economics is + + align:start position:0% +economy but the standard of economics is + + + align:start position:0% +economy but the standard of economics is +the market knows best + + align:start position:0% +the market knows best + + + align:start position:0% +the market knows best +okay and that leads us to the last thing + + align:start position:0% +okay and that leads us to the last thing + + + align:start position:0% +okay and that leads us to the last thing +i want to talk about + + align:start position:0% +i want to talk about + + + align:start position:0% +i want to talk about +which is basically how freely should an + + align:start position:0% +which is basically how freely should an + + + align:start position:0% +which is basically how freely should an +economy function let's step back to the + + align:start position:0% +economy function let's step back to the + + + align:start position:0% +economy function let's step back to the +giant picture + + align:start position:0% +giant picture + + + align:start position:0% +giant picture +let's step back from a market for roses + + align:start position:0% +let's step back from a market for roses + + + align:start position:0% +let's step back from a market for roses +to the entire economy + + align:start position:0% +to the entire economy + + + align:start position:0% +to the entire economy +how freely should a market should an + + align:start position:0% +how freely should a market should an + + + align:start position:0% +how freely should a market should an +economy function + + align:start position:0% +economy function + + + align:start position:0% +economy function +we have what's known as a capitalistic + + align:start position:0% +we have what's known as a capitalistic + + + align:start position:0% +we have what's known as a capitalistic +economy + + align:start position:0% +economy + + + align:start position:0% +economy +in a capitalistic economy firms that + + align:start position:0% +in a capitalistic economy firms that + + + align:start position:0% +in a capitalistic economy firms that +individuals decide what to produce and + + align:start position:0% +individuals decide what to produce and + + + align:start position:0% +individuals decide what to produce and +consume + + align:start position:0% +consume + + + align:start position:0% +consume +may be subject to some rules of the road + + align:start position:0% +may be subject to some rules of the road + + + align:start position:0% +may be subject to some rules of the road +set by the government there's some + + align:start position:0% +set by the government there's some + + + align:start position:0% +set by the government there's some +minimal rules of the road + + align:start position:0% +minimal rules of the road + + + align:start position:0% +minimal rules of the road +to try to avoid fraud or misinformation + + align:start position:0% +to try to avoid fraud or misinformation + + + align:start position:0% +to try to avoid fraud or misinformation +but otherwise we let the dice roll + + align:start position:0% +but otherwise we let the dice roll + + + align:start position:0% +but otherwise we let the dice roll +firms and consumers decide sort of what + + align:start position:0% +firms and consumers decide sort of what + + + align:start position:0% +firms and consumers decide sort of what +to uh + + align:start position:0% +to uh + + + align:start position:0% +to uh +what to do now this has led to + + align:start position:0% +what to do now this has led to + + + align:start position:0% +what to do now this has led to +tremendous growth + + align:start position:0% +tremendous growth + + + align:start position:0% +tremendous growth +okay america was not a wealthy nation it + + align:start position:0% +okay america was not a wealthy nation it + + + align:start position:0% +okay america was not a wealthy nation it +was not very wealthy nation + + align:start position:0% +was not very wealthy nation + + + align:start position:0% +was not very wealthy nation +a hundred years ago 150 years ago it's + + align:start position:0% +a hundred years ago 150 years ago it's + + + align:start position:0% +a hundred years ago 150 years ago it's +led to tremendous growth where we are + + align:start position:0% +led to tremendous growth where we are + + + align:start position:0% +led to tremendous growth where we are +now + + align:start position:0% +now + + + align:start position:0% +now +the most powerful still the most + + align:start position:0% +the most powerful still the most + + + align:start position:0% +the most powerful still the most +powerful and wealthiest nation in the + + align:start position:0% +powerful and wealthiest nation in the + + + align:start position:0% +powerful and wealthiest nation in the +world + + align:start position:0% +world + + + align:start position:0% +world +okay largely driven by the + + align:start position:0% +okay largely driven by the + + + align:start position:0% +okay largely driven by the +capitalist nation capitalistic nature of + + align:start position:0% +capitalist nation capitalistic nature of + + + align:start position:0% +capitalist nation capitalistic nature of +our economy + + align:start position:0% +our economy + + + align:start position:0% +our economy +on the other hand we are a nation with + + align:start position:0% +on the other hand we are a nation with + + + align:start position:0% +on the other hand we are a nation with +tremendous inequality + + align:start position:0% +tremendous inequality + + + align:start position:0% +tremendous inequality +we are by far the most unequal major + + align:start position:0% +we are by far the most unequal major + + + align:start position:0% +we are by far the most unequal major +nation in the world okay + + align:start position:0% +nation in the world okay + + + align:start position:0% +nation in the world okay +the top one percent of americans has a + + align:start position:0% +the top one percent of americans has a + + + align:start position:0% +the top one percent of americans has a +much higher share of our income + + align:start position:0% +much higher share of our income + + + align:start position:0% +much higher share of our income +than in any other large country in the + + align:start position:0% +than in any other large country in the + + + align:start position:0% +than in any other large country in the +world any other large developed country + + align:start position:0% +world any other large developed country + + + align:start position:0% +world any other large developed country +in the world + + align:start position:0% +in the world + + + align:start position:0% +in the world +the bottom 99 has less of our income + + align:start position:0% +the bottom 99 has less of our income + + + align:start position:0% +the bottom 99 has less of our income +corresponding than anywhere else so it's + + align:start position:0% +corresponding than anywhere else so it's + + + align:start position:0% +corresponding than anywhere else so it's +led to major inequality + + align:start position:0% +led to major inequality + + + align:start position:0% +led to major inequality +and it's led to other problems it turns + + align:start position:0% +and it's led to other problems it turns + + + align:start position:0% +and it's led to other problems it turns +out that the government can + + align:start position:0% +out that the government can + + + align:start position:0% +out that the government can +appropriately set the rules the road to + + align:start position:0% +appropriately set the rules the road to + + + align:start position:0% +appropriately set the rules the road to +avoid things like fraud + + align:start position:0% +avoid things like fraud + + + align:start position:0% +avoid things like fraud +as we saw with enron if you remember + + align:start position:0% +as we saw with enron if you remember + + + align:start position:0% +as we saw with enron if you remember +back to that or a lot of what happened + + align:start position:0% +back to that or a lot of what happened + + + align:start position:0% +back to that or a lot of what happened +during the financial meltdown + + align:start position:0% +during the financial meltdown + + + align:start position:0% +during the financial meltdown +it turns out it's hard to get people + + align:start position:0% +it turns out it's hard to get people + + + align:start position:0% +it turns out it's hard to get people +perfect information etc + + align:start position:0% +perfect information etc + + + align:start position:0% +perfect information etc +so we've seen the problems we've grown + + align:start position:0% +so we've seen the problems we've grown + + + align:start position:0% +so we've seen the problems we've grown +very wealthy as a nation + + align:start position:0% +very wealthy as a nation + + + align:start position:0% +very wealthy as a nation +but we've introduced a whole set of + + align:start position:0% +but we've introduced a whole set of + + + align:start position:0% +but we've introduced a whole set of +problems through the system + + align:start position:0% +problems through the system + + + align:start position:0% +problems through the system +now the other extreme is what's called + + align:start position:0% +now the other extreme is what's called + + + align:start position:0% +now the other extreme is what's called +the command economy + + align:start position:0% +the command economy + + + align:start position:0% +the command economy +rather than a capitalist economy is + + align:start position:0% +rather than a capitalist economy is + + + align:start position:0% +rather than a capitalist economy is +what's called a command economy + + align:start position:0% +what's called a command economy + + + align:start position:0% +what's called a command economy +okay in this case the government makes + + align:start position:0% +okay in this case the government makes + + + align:start position:0% +okay in this case the government makes +all the production and consumption + + align:start position:0% +all the production and consumption + + + align:start position:0% +all the production and consumption +decisions the government needs to set + + align:start position:0% +decisions the government needs to set + + + align:start position:0% +decisions the government needs to set +the rules the road the government + + align:start position:0% +the rules the road the government + + + align:start position:0% +the rules the road the government +owns the road the government says we're + + align:start position:0% +owns the road the government says we're + + + align:start position:0% +owns the road the government says we're +going to produce this many + + align:start position:0% +going to produce this many + + + align:start position:0% +going to produce this many +cars this year okay and people + + align:start position:0% +cars this year okay and people + + + align:start position:0% +cars this year okay and people +can get them in some way it could be a + + align:start position:0% +can get them in some way it could be a + + + align:start position:0% +can get them in some way it could be a +lottery could be waiting in line however + + align:start position:0% +lottery could be waiting in line however + + + align:start position:0% +lottery could be waiting in line however +we decide to allocate them + + align:start position:0% +we decide to allocate them + + + align:start position:0% +we decide to allocate them +we're not going to let the market + + align:start position:0% +we're not going to let the market + + + align:start position:0% +we're not going to let the market +allocate them we the government will + + align:start position:0% +allocate them we the government will + + + align:start position:0% +allocate them we the government will +allocate them well okay how many get + + align:start position:0% +allocate them well okay how many get + + + align:start position:0% +allocate them well okay how many get +produced + + align:start position:0% +produced + + + align:start position:0% +produced +and who gets them okay and this was the + + align:start position:0% +and who gets them okay and this was the + + + align:start position:0% +and who gets them okay and this was the +model the soviet union that i grew up + + align:start position:0% +model the soviet union that i grew up + + + align:start position:0% +model the soviet union that i grew up +with + + align:start position:0% +with + + + align:start position:0% +with +okay this was the pre-1989 soviet union + + align:start position:0% +okay this was the pre-1989 soviet union + + + align:start position:0% +okay this was the pre-1989 soviet union +okay the government decided how many + + align:start position:0% +okay the government decided how many + + + align:start position:0% +okay the government decided how many +shirts cars cds every i mean it's sort + + align:start position:0% +shirts cars cds every i mean it's sort + + + align:start position:0% +shirts cars cds every i mean it's sort +of bizarre to think about literally + + align:start position:0% +of bizarre to think about literally + + + align:start position:0% +of bizarre to think about literally +everything + + align:start position:0% +everything + + + align:start position:0% +everything +the government decided how much to + + align:start position:0% +the government decided how much to + + + align:start position:0% +the government decided how much to +produce and by and large the government + + align:start position:0% +produce and by and large the government + + + align:start position:0% +produce and by and large the government +decided who got it + + align:start position:0% +decided who got it + + + align:start position:0% +decided who got it +partly through corruption that is the + + align:start position:0% +partly through corruption that is the + + + align:start position:0% +partly through corruption that is the +party p the party members + + align:start position:0% +party p the party members + + + align:start position:0% +party p the party members +party leaders got it first and often + + align:start position:0% +party leaders got it first and often + + + align:start position:0% +party leaders got it first and often +just through waiting in line + + align:start position:0% +just through waiting in line + + + align:start position:0% +just through waiting in line +for the remaining application now in + + align:start position:0% +for the remaining application now in + + + align:start position:0% +for the remaining application now in +theory + + align:start position:0% +theory + + + align:start position:0% +theory +this ensured equity by making sure that + + align:start position:0% +this ensured equity by making sure that + + + align:start position:0% +this ensured equity by making sure that +everybody is shot at things + + align:start position:0% +everybody is shot at things + + + align:start position:0% +everybody is shot at things +in practice it didn't work well at all + + align:start position:0% +in practice it didn't work well at all + + + align:start position:0% +in practice it didn't work well at all +and actually was what dragged down + + align:start position:0% +and actually was what dragged down + + + align:start position:0% +and actually was what dragged down +the collapse of the old soviet economy + + align:start position:0% +the collapse of the old soviet economy + + + align:start position:0% +the collapse of the old soviet economy +was that the command model + + align:start position:0% +was that the command model + + + align:start position:0% +was that the command model +simply doesn't work partly there's just + + align:start position:0% +simply doesn't work partly there's just + + + align:start position:0% +simply doesn't work partly there's just +too many opportunities for corruption + + align:start position:0% +too many opportunities for corruption + + + align:start position:0% +too many opportunities for corruption +when the government controls everything + + align:start position:0% +when the government controls everything + + + align:start position:0% +when the government controls everything +that means there's no checks and + + align:start position:0% +that means there's no checks and + + + align:start position:0% +that means there's no checks and +balances + + align:start position:0% +balances + + + align:start position:0% +balances +on the the the the opportunity for + + align:start position:0% +on the the the the opportunity for + + + align:start position:0% +on the the the the opportunity for +enormous corruption + + align:start position:0% +enormous corruption + + + align:start position:0% +enormous corruption +the capitalist economy puts some natural + + align:start position:0% +the capitalist economy puts some natural + + + align:start position:0% +the capitalist economy puts some natural +checks and balances on that + + align:start position:0% +checks and balances on that + + + align:start position:0% +checks and balances on that +and partly because it turns out that + + align:start position:0% +and partly because it turns out that + + + align:start position:0% +and partly because it turns out that +it's hard to control human nature + + align:start position:0% +it's hard to control human nature + + + align:start position:0% +it's hard to control human nature +and adam smith had it right adam smith + + align:start position:0% +and adam smith had it right adam smith + + + align:start position:0% +and adam smith had it right adam smith +talks about the invisible hand + + align:start position:0% +talks about the invisible hand + + + align:start position:0% +talks about the invisible hand +of the capitalist economy the invisible + + align:start position:0% +of the capitalist economy the invisible + + + align:start position:0% +of the capitalist economy the invisible +hand is + + align:start position:0% +hand is + + + align:start position:0% +hand is +basically the notion that the capitalist + + align:start position:0% +basically the notion that the capitalist + + + align:start position:0% +basically the notion that the capitalist +economy will manage distribute things + + align:start position:0% +economy will manage distribute things + + + align:start position:0% +economy will manage distribute things +roughly + + align:start position:0% +roughly + + + align:start position:0% +roughly +in proportion what people want okay and + + align:start position:0% +in proportion what people want okay and + + + align:start position:0% +in proportion what people want okay and +that's + + align:start position:0% +that's + + + align:start position:0% +that's +where peak folks want to be they folks + + align:start position:0% +where peak folks want to be they folks + + + align:start position:0% +where peak folks want to be they folks +who want a certain kind of car are going + + align:start position:0% +who want a certain kind of car are going + + + align:start position:0% +who want a certain kind of car are going +to want to get to that kind of car + + align:start position:0% +to want to get to that kind of car + + + align:start position:0% +to want to get to that kind of car +and the government has it wrong they're + + align:start position:0% +and the government has it wrong they're + + + align:start position:0% +and the government has it wrong they're +going to get upset and it's going to + + align:start position:0% +going to get upset and it's going to + + + align:start position:0% +going to get upset and it's going to +lead to a less functional economy + + align:start position:0% +lead to a less functional economy + + + align:start position:0% +lead to a less functional economy +okay so basically um + + align:start position:0% +okay so basically um + + + align:start position:0% +okay so basically um +adam smith's view is that the invisible + + align:start position:0% +adam smith's view is that the invisible + + + align:start position:0% +adam smith's view is that the invisible +hand view is that consumers + + align:start position:0% +hand view is that consumers + + + align:start position:0% +hand view is that consumers +and firms serving their own best + + align:start position:0% +and firms serving their own best + + + align:start position:0% +and firms serving their own best +interest + + align:start position:0% +interest + + + align:start position:0% +interest +will do what is best for society okay so + + align:start position:0% +will do what is best for society okay so + + + align:start position:0% +will do what is best for society okay so +the fundamental core of the capitalistic + + align:start position:0% +the fundamental core of the capitalistic + + + align:start position:0% +the fundamental core of the capitalistic +view + + align:start position:0% +view + + + align:start position:0% +view +is the consumers and firms serving their + + align:start position:0% +is the consumers and firms serving their + + + align:start position:0% +is the consumers and firms serving their +own best interests + + align:start position:0% +own best interests + + + align:start position:0% +own best interests +will do what ends up being best for + + align:start position:0% +will do what ends up being best for + + + align:start position:0% +will do what ends up being best for +society and that's essentially the model + + align:start position:0% +society and that's essentially the model + + + align:start position:0% +society and that's essentially the model +we'll learn to start in this course + + align:start position:0% +we'll learn to start in this course + + + align:start position:0% +we'll learn to start in this course +yeah um in that definition are we + + align:start position:0% +yeah um in that definition are we + + + align:start position:0% +yeah um in that definition are we +defining the best for society as you're + + align:start position:0% +defining the best for society as you're + + + align:start position:0% +defining the best for society as you're +like like everybody has the most money + + align:start position:0% +like like everybody has the most money + + + align:start position:0% +like like everybody has the most money +or like everyone has the best health or + + align:start position:0% +or like everyone has the best health or + + + align:start position:0% +or like everyone has the best health or +the best and from living like + + align:start position:0% +the best and from living like + + + align:start position:0% +the best and from living like +what is the best great great question + + align:start position:0% +what is the best great great question + + + align:start position:0% +what is the best great great question +we're going to spend a lot of the + + align:start position:0% +we're going to spend a lot of the + + + align:start position:0% +we're going to spend a lot of the +semester talking about that + + align:start position:0% +semester talking about that + + + align:start position:0% +semester talking about that +for now we're going to find best for + + align:start position:0% +for now we're going to find best for + + + align:start position:0% +for now we're going to find best for +society as the most + + align:start position:0% +society as the most + + + align:start position:0% +society as the most +stuff gets produced and consumed okay + + align:start position:0% +stuff gets produced and consumed okay + + + align:start position:0% +stuff gets produced and consumed okay +that's how we're going to find it + + align:start position:0% +that's how we're going to find it + + + align:start position:0% +that's how we're going to find it +obviously you've raised a set of issues + + align:start position:0% +obviously you've raised a set of issues + + + align:start position:0% +obviously you've raised a set of issues +about what about pollution what about + + align:start position:0% +about what about pollution what about + + + align:start position:0% +about what about pollution what about +health + + align:start position:0% +health + + + align:start position:0% +health +etc we're going to come to those but for + + align:start position:0% +etc we're going to come to those but for + + + align:start position:0% +etc we're going to come to those but for +the first + + align:start position:0% +the first + + + align:start position:0% +the first +two thirds of the course best for + + align:start position:0% +two thirds of the course best for + + + align:start position:0% +two thirds of the course best for +society means + + align:start position:0% +society means + + + align:start position:0% +society means +what we're going to call maximum surplus + + align:start position:0% +what we're going to call maximum surplus + + + align:start position:0% +what we're going to call maximum surplus +which is + + align:start position:0% +which is + + + align:start position:0% +which is +the most stuff gets produced that people + + align:start position:0% +the most stuff gets produced that people + + + align:start position:0% +the most stuff gets produced that people +value okay + + align:start position:0% +value okay + + + align:start position:0% +value okay +so that's that's how we're going to do + + align:start position:0% +so that's that's how we're going to do + + + align:start position:0% +so that's that's how we're going to do +it and in his view the visual hand does + + align:start position:0% +it and in his view the visual hand does + + + align:start position:0% +it and in his view the visual hand does +that + + align:start position:0% +that + + + align:start position:0% +that +and by and large by and large it's a + + align:start position:0% +and by and large by and large it's a + + + align:start position:0% +and by and large by and large it's a +very helpful framework + + align:start position:0% +very helpful framework + + + align:start position:0% +very helpful framework +to turn to okay however at least the + + align:start position:0% +to turn to okay however at least the + + + align:start position:0% +to turn to okay however at least the +outcomes that + + align:start position:0% +outcomes that + + + align:start position:0% +outcomes that +can lead to outcomes that are not very + + align:start position:0% +can lead to outcomes that are not very + + + align:start position:0% +can lead to outcomes that are not very +fair so the way we're going to proceed + + align:start position:0% +fair so the way we're going to proceed + + + align:start position:0% +fair so the way we're going to proceed +in this course + + align:start position:0% +in this course + + + align:start position:0% +in this course +is we're going to start by talking about + + align:start position:0% +is we're going to start by talking about + + + align:start position:0% +is we're going to start by talking about +how adam smith's magic works + + align:start position:0% +how adam smith's magic works + + + align:start position:0% +how adam smith's magic works +how does the magic happen how does + + align:start position:0% +how does the magic happen how does + + + align:start position:0% +how does the magic happen how does +individuals and firms act in their own + + align:start position:0% +individuals and firms act in their own + + + align:start position:0% +individuals and firms act in their own +self-interest + + align:start position:0% +self-interest + + + align:start position:0% +self-interest +without caring about anybody else end up + + align:start position:0% +without caring about anybody else end up + + + align:start position:0% +without caring about anybody else end up +yielding + + align:start position:0% +yielding + + + align:start position:0% +yielding +the largest si possible the the largest + + align:start position:0% +the largest si possible the the largest + + + align:start position:0% +the largest si possible the the largest +possible productive economy + + align:start position:0% +possible productive economy + + + align:start position:0% +possible productive economy +okay how does that happen okay and we're + + align:start position:0% +okay how does that happen okay and we're + + + align:start position:0% +okay how does that happen okay and we're +going to talk about that + + align:start position:0% +going to talk about that + + + align:start position:0% +going to talk about that +we'll start with demand which is how do + + align:start position:0% +we'll start with demand which is how do + + + align:start position:0% +we'll start with demand which is how do +consumers decide what they want + + align:start position:0% +consumers decide what they want + + + align:start position:0% +consumers decide what they want +given their resources we'll talk about + + align:start position:0% +given their resources we'll talk about + + + align:start position:0% +given their resources we'll talk about +the principle of utility maximization + + align:start position:0% +the principle of utility maximization + + + align:start position:0% +the principle of utility maximization +the idea that i have utility function + + align:start position:0% +the idea that i have utility function + + + align:start position:0% +the idea that i have utility function +that i can math mathematically write + + align:start position:0% +that i can math mathematically write + + + align:start position:0% +that i can math mathematically write +down + + align:start position:0% +down + + + align:start position:0% +down +what i want i'll have a budget + + align:start position:0% +what i want i'll have a budget + + + align:start position:0% +what i want i'll have a budget +constraint which is the resource i have + + align:start position:0% +constraint which is the resource i have + + + align:start position:0% +constraint which is the resource i have +and the ones do constrained optimization + + align:start position:0% +and the ones do constrained optimization + + + align:start position:0% +and the ones do constrained optimization +we'll say give them what i want and the + + align:start position:0% +we'll say give them what i want and the + + + align:start position:0% +we'll say give them what i want and the +resource i have + + align:start position:0% +resource i have + + + align:start position:0% +resource i have +what decisions do i make boom we get the + + align:start position:0% +what decisions do i make boom we get the + + + align:start position:0% +what decisions do i make boom we get the +demand curve then we'll turn to supply + + align:start position:0% +demand curve then we'll turn to supply + + + align:start position:0% +demand curve then we'll turn to supply +and we'll talk about how do firms decide + + align:start position:0% +and we'll talk about how do firms decide + + + align:start position:0% +and we'll talk about how do firms decide +what to produce + + align:start position:0% +what to produce + + + align:start position:0% +what to produce +that's much more complicated because + + align:start position:0% +that's much more complicated because + + + align:start position:0% +that's much more complicated because +firms have to decide what inputs to use + + align:start position:0% +firms have to decide what inputs to use + + + align:start position:0% +firms have to decide what inputs to use +and what outputs to produce and we'll + + align:start position:0% +and what outputs to produce and we'll + + + align:start position:0% +and what outputs to produce and we'll +talk about how firms operate + + align:start position:0% +talk about how firms operate + + + align:start position:0% +talk about how firms operate +can operate in very different markets + + align:start position:0% +can operate in very different markets + + + align:start position:0% +can operate in very different markets +there's a competitive market that + + align:start position:0% +there's a competitive market that + + + align:start position:0% +there's a competitive market that +smith envisioned but that doesn't always + + align:start position:0% +smith envisioned but that doesn't always + + + align:start position:0% +smith envisioned but that doesn't always +work sometimes we get monopoly markets + + align:start position:0% +work sometimes we get monopoly markets + + + align:start position:0% +work sometimes we get monopoly markets +okay where one firm dominates and you + + align:start position:0% +okay where one firm dominates and you + + + align:start position:0% +okay where one firm dominates and you +can actually end up outcomes which + + align:start position:0% +can actually end up outcomes which + + + align:start position:0% +can actually end up outcomes which +aren't the best possible outcome even + + align:start position:0% +aren't the best possible outcome even + + + align:start position:0% +aren't the best possible outcome even +with the invisible hand + + align:start position:0% +with the invisible hand + + + align:start position:0% +with the invisible hand +okay so we'll talk about different kinds + + align:start position:0% +okay so we'll talk about different kinds + + + align:start position:0% +okay so we'll talk about different kinds +of markets then we'll put it together to + + align:start position:0% +of markets then we'll put it together to + + + align:start position:0% +of markets then we'll put it together to +get market equilibrium + + align:start position:0% +get market equilibrium + + + align:start position:0% +get market equilibrium +and talk about sort of smith's + + align:start position:0% +and talk about sort of smith's + + + align:start position:0% +and talk about sort of smith's +principles and then from there we'll + + align:start position:0% +principles and then from there we'll + + + align:start position:0% +principles and then from there we'll +talk about how it + + align:start position:0% +talk about how it + + + align:start position:0% +talk about how it +breaks down in reality different change + + align:start position:0% +breaks down in reality different change + + + align:start position:0% +breaks down in reality different change +in reality how there are various market + + align:start position:0% +in reality how there are various market + + + align:start position:0% +in reality how there are various market +failures + + align:start position:0% +failures + + + align:start position:0% +failures +that can get in the way why we have to + + align:start position:0% +that can get in the way why we have to + + + align:start position:0% +that can get in the way why we have to +care about equity and what implications + + align:start position:0% +care about equity and what implications + + + align:start position:0% +care about equity and what implications +that has + + align:start position:0% +that has + + + align:start position:0% +that has +about behavioral economics about a set + + align:start position:0% +about behavioral economics about a set + + + align:start position:0% +about behavioral economics about a set +of other factors + + align:start position:0% +of other factors + + + align:start position:0% +of other factors +okay so that's basically how we're going + + align:start position:0% +okay so that's basically how we're going + + + align:start position:0% +okay so that's basically how we're going +to proceed uh this semester + + align:start position:0% +to proceed uh this semester + + + align:start position:0% +to proceed uh this semester +as i said the lectures are important but + + align:start position:0% +as i said the lectures are important but + + + align:start position:0% +as i said the lectures are important but +the rest stations are as well + + align:start position:0% +the rest stations are as well + + + align:start position:0% +the rest stations are as well +once we're sort of in steady state the + + align:start position:0% +once we're sort of in steady state the + + + align:start position:0% +once we're sort of in steady state the +rest station is about half + + align:start position:0% +rest station is about half + + + align:start position:0% +rest station is about half +uh working half new material and half + + align:start position:0% +uh working half new material and half + + + align:start position:0% +uh working half new material and half +working through problems + + align:start position:0% +working through problems + + + align:start position:0% +working through problems +to help you prepare for the next problem + + align:start position:0% +to help you prepare for the next problem + + + align:start position:0% +to help you prepare for the next problem +set so the problem sets are going to + + align:start position:0% +set so the problem sets are going to + + + align:start position:0% +set so the problem sets are going to +work + + align:start position:0% +work + + + align:start position:0% +work +is the problem set that's assigned will + + align:start position:0% +is the problem set that's assigned will + + + align:start position:0% +is the problem set that's assigned will +cover material that's taught + + align:start position:0% +cover material that's taught + + + align:start position:0% +cover material that's taught +up to that date so for example problem + + align:start position:0% +up to that date so for example problem + + + align:start position:0% +up to that date so for example problem +set one is to be assigned next friday + + align:start position:0% +set one is to be assigned next friday + + + align:start position:0% +set one is to be assigned next friday +that will cover everything you've + + align:start position:0% +that will cover everything you've + + + align:start position:0% +that will cover everything you've +learned up through next wednesday + + align:start position:0% +learned up through next wednesday + + + align:start position:0% +learned up through next wednesday +okay therefore in section on next friday + + align:start position:0% +okay therefore in section on next friday + + + align:start position:0% +okay therefore in section on next friday +we'll do a practice problem + + align:start position:0% +we'll do a practice problem + + + align:start position:0% +we'll do a practice problem +which will help which you should + + align:start position:0% +which will help which you should + + + align:start position:0% +which will help which you should +understand because we'll cover things + + align:start position:0% +understand because we'll cover things + + + align:start position:0% +understand because we'll cover things +we've taught in class + + align:start position:0% +we've taught in class + + + align:start position:0% +we've taught in class +and he'll prepare you for the problem + + align:start position:0% +and he'll prepare you for the problem + + + align:start position:0% +and he'll prepare you for the problem +set and we'll do that every week + + align:start position:0% +set and we'll do that every week + + + align:start position:0% +set and we'll do that every week +that about half the sections the other + + align:start position:0% +that about half the sections the other + + + align:start position:0% +that about half the sections the other +half the section will be new material + + align:start position:0% +half the section will be new material + + + align:start position:0% +half the section will be new material +okay this friday the section friday is + + align:start position:0% +okay this friday the section friday is + + + align:start position:0% +okay this friday the section friday is +all new material + + align:start position:0% +all new material + + + align:start position:0% +all new material +we're doing fridays cover the + + align:start position:0% +we're doing fridays cover the + + + align:start position:0% +we're doing fridays cover the +mathematics i don't like doing math + + align:start position:0% +mathematics i don't like doing math + + + align:start position:0% +mathematics i don't like doing math +i always get it wrong okay so i leave + + align:start position:0% +i always get it wrong okay so i leave + + + align:start position:0% +i always get it wrong okay so i leave +math for the tas who are smarter than i + + align:start position:0% +math for the tas who are smarter than i + + + align:start position:0% +math for the tas who are smarter than i +am + + align:start position:0% +am + + + align:start position:0% +am +okay so this friday we're doing the + + align:start position:0% +okay so this friday we're doing the + + + align:start position:0% +okay so this friday we're doing the +mathematics of supply and demand + + align:start position:0% +mathematics of supply and demand + + + align:start position:0% +mathematics of supply and demand +and how you take the intuition here and + + align:start position:0% +and how you take the intuition here and + + + align:start position:0% +and how you take the intuition here and +the simple graphics and actually turn it + + align:start position:0% +the simple graphics and actually turn it + + + align:start position:0% +the simple graphics and actually turn it +into + + align:start position:0% +into + + + align:start position:0% +into +mathematical representations which is + + align:start position:0% +mathematical representations which is + + + align:start position:0% +mathematical representations which is +what you need for the problem sets + + align:start position:0% +what you need for the problem sets + + + align:start position:0% +what you need for the problem sets +that this friday then we'll come back on + + align:start position:0% +that this friday then we'll come back on + + + align:start position:0% +that this friday then we'll come back on +monday and start talking about + + align:start position:0% +monday and start talking about + + + align:start position:0% +monday and start talking about +uh what's underneath the demand curve + + align:start position:0% +uh what's underneath the demand curve + + + align:start position:0% +uh what's underneath the demand curve +all right any other questions + + align:start position:0% +all right any other questions + + + align:start position:0% +all right any other questions +okay i'll see you on monday \ No newline at end of file diff --git a/__tGxUu5BTc.txt b/__tGxUu5BTc.txt new file mode 100644 index 0000000000000000000000000000000000000000..161c88f26567f6afd3606243883114df56d3ad0a --- /dev/null +++ b/__tGxUu5BTc.txt @@ -0,0 +1,3018 @@ +The following +content is provided + +under a Creative +Commons license. + +Your support will help MIT +OpenCourseWare continue + +to offer high quality +educational resources for free. + +To make a donation or +view additional materials + +from hundreds of MIT courses, +visit MIT OpenCourseWare + +at ocw.mit.edu. + +PROFESSOR: Let's start. + +Any questions? + +We've been gradually building +up thermodynamics, culminating + +in what I call the most +important fundamental relation, + +which was the E is +T dS plus Ji dxi. + +And essentially +we said that this + +was some statement of +conservation of energy. + +where there's a heat component +that goes into the system, + +and there's a work component. + +And actually, we ended up +breaking the work component + +into a mechanical part +and a chemical part, + +which we wrote as +mu alpha dN alpha. + +I guess if I don't +write the sums, + +the summation +convention is assumed. + +Now, this gave us an idea of +what a thermodynamic system is, + +in the sense of how many +coordinates do we need in order + +to place the system +in equilibrium + +somewhere in some +coordinate space. + +And we said that we can just +count the number of variables + +that we have on this side. + +And indeed, for +the case of energy, + +the natural set of variables +would be S, x, and N. + +And given some place in +the coordinate system that + +is S, x, and N, you +could find a point that + +corresponds to that +thermodynamic equilibrium + +state. + +Now, having gotten this +fundamental relation, + +we can manipulate and write +it in different fashion. + +And in particular, +for example, you + +can write the S is dE by +dT, minus Ji dxi over T, + +minus mu alpha dN alpha over +T. So you could in principle + +express everything rather than +in terms of entropy-- which + +in some circumstances may not +be the right variable-- in terms + +of the energy content of +the system and the variables + +that you need in order to +make work type of changes + +on the system. + +And we saw that other +versions of it is possible. + +So for example, we +could rearrange. + +Rather than looking +at E, we could + +look at E minus TS, the +quantity that we call F. + +And then dF would look very +much like the original equation. + +Rather than T dS, we +would get minus S dT. + +And clearly, for +this quantity F, + +the natural variables +are T, x, and N. + +And there were other +types of these functions + +that we construct. + +So basically at this stage, we +have a formula that tells us + +how to navigate our way +in this space of things + +that are in equilibrium. + +And by taking various +derivatives of equilibrium + +functions with +respect to each other, + +we can express other ones. + +And via this methodology, we can +relate to many different things + +to each other and have +mathematical relations + +between physical observables. + +So following up on +that, we then ask + +what are some other mathematical +forms that we can look at. + +And one set of forms +followed from extensivity. + +And we saw that if we were +under circumstances such + +that we were to multiply all +of the extensive variables + +by some factor-- 2, 3, +whatever-- and the energy + +content would increase +by that same factor, + +then we could in fact +integrate the equation + +and drop the d's and +write it in this fashion-- + +TS Jx plus mu N, regarding +these as kind of vectors. + +And importantly, that told us +that the intensive variables + +were not independent +of each other. + +And you had relationship that +you-- S dT plus Ji xi dJi + +plus N alpha d mu alpha is 0. + +And last time, I +did one calculation + +using this Gibbs-Duhem +relation that I repeat. + +And that was for a gas isotherm. + +Isotherm corresponds +to dT goes to 0. + +And the analogue of hydrostatic +work for a gas was minus P + +for J. So this becomes +minus V dP plus N d mu. + +If you have one +component, it goes to 0. + +And we said that this +gives us the relationship + +along an isotherm. + +So for a fixed T, d +mu by dP is V over N. + +I'll come back to that shortly. + +Towards the end +of last lecture, I + +mentioned that we +can get a number + +of other so-called +Maxwell relations + +by noting that mixed +second derivatives are + +independent of the order +of taking derivatives. + +So that if you have some df +of x and y written as df by dx + +at constant y dx, plus df +by dy at constant x dy, + +then the order of the +second derivatives, which + +would be obtained +by taking either + +a derivative of the +first term with respect + +to y or the second term +with respect to x-- + +doesn't matter which order. + +So let's start with +our initial equation. + +And for simplicity, +let's think of cases + +where we have a fixed +number of particles + +so that we can write +dE as T dS plus Ji dxi. + +So this looks like this dF +that I wrote before for you. + +And I can identify temperature +as dE by dS at constant x, + +and each one of the forces Ji +as dE by dxi at constant S. + +And all of the J's that are +not equal to i kept fixed. + +And then, since the +second derivative + +is irrespective of order, I +can form the second derivative + +with respect to the combination +S xi into a different fashion. + +I can either take a derivative +over here-- I already + +have derivative with +respect to S giving me T, + +so I will get dT by dxi, +essentially at constant S-- + +or I can take the +derivative of this object. + +I already have the x derivative, +so I take the S derivative. + +So I have dJi with respect +to S at constant x. + +So this is an example +of the Maxwell relation. + +And just to remind +you, we can always + +invert these derivatives. + +So I can invert this +and say that actually, + +if I had wondered how +the entropy changes + +as a function of a force such +as pressure at constant x, + +it would be related to how +the corresponding displacement + +to the force changes as a +function of temperature. + +So you would have a relationship +between some observable + +such as how the length +of a wire changes + +if you change +temperature rapidly, + +and how the entropy would change +as a function of pressure, + +or corresponding force, +whatever it may be. + +Now, what I would like to +remind you is that the best + +way to sort of derive +these relationships + +is to reconstruct +what kind of second + +derivative or mixed +derivative you + +want to have to give +you the right result. + +So for example, say +somebody told me + +that I want to calculate +something similar-- dS by dJ, + +let's say at +constant temperature. + +How do I calculate that? + +A nice way to calculate +that is if I somehow + +manipulate so that S appears +as a first derivative. + +Now, S does not appear as +a first derivative here, + +but certainly appears as +a first derivative here. + +So who says I have to take +E as a function of state? + +I can look at the +second derivative of F. + +So if I look at F, +which is E minus TS-- + +and actually, I don't +even need to know + +what the name of this entity is, +whether it's F, G, et cetera. + +All I know is that it will +convert this to minus S dT-- + +the TS that I don't want, +so that S appears now + +as a first derivative. + +Now I want to take a +derivative of S with respect + +to J. If I just stop here, the +next term that I would have + +is Ji dxi. + +And the natural way that I would +construct a second derivative + +would give me dS +with respect to xi. + +But I want the S +with respect to Ji. + +So I say, OK, I'll do +this function instead. + +As I said, I don't +really care what + +the name of these functions is. + +This will get +converted to xi dJ. + +Now I can say there is +this first derivative-- d o + +minus S with respect +to Ji at constant T + +is the same thing as d +of minus y with respect + +to T at constant J. So I can +get rid of the minus sign + +if I want, and I have +the answer that I want. + +It is dxi by dT at constant +J-- at constant-- yeah, T-- J. + +And you can go and construct +anything else that you like. + +Let me, for example, +try to construct + +this entity we +already calculated. + +So let's see. + +What can I say about d mu by +dP at constant temperature, + +and I want to calculate +that via a Maxwell relation? + +So what do I know? + +I know that dE is +T dS minus pdV. + +Good. + +Oh, I want to have +mu in the play, + +so now I have to add mu dN. + +That's good, because I have +mu as a first derivative. + +I have it over here. + +But I have P as a +first derivative, + +whereas I want P to appear as +the work element, something + +like dP. + +So what I will do is I will +make this d of E plus pV. + +This converts this to +plus V dP plus mu dN. + +That's fine, except that +when I do things now, + +I would have calculated +things at constant S. + +And I want to calculate +things at constant T. + +That's not really important. + +I do a minus ST. This +becomes minus S dT. + +And then I have a +function of state-- + +I don't care what +it's called-- that has + +the right format for me +to identify that d mu + +by dP at constant N and T, +along an isotherm of a fixed + +number of particles, +is the same thing as dV + +by dN at constant PN T. So +that's my Maxwell relation. + +So why didn't I get this result? + +Did I make a mistake? + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: Louder. + +AUDIENCE: Is this valid +for extensive systems? + +PROFESSOR: Yes, this is +valid for extensive system. + +I used extensively in +the relation of this. + +And here, I never +used extensivity. + +But if I have a system that +I tell you its pressure + +and temperature, how +is its volume related + +to the number of particles? + +I have a box in this room. + +I tell you pressure and +temperature are fixed. + +If I make the box twice as big, +number of particles, volume + +will go twice as big. + +So if I were to +apply extensivity, + +I would have to conclude that +this is the same thing as V + +over N, and I would +be in agreement + +with what I had before. + +Any questions? + +Yes. + +AUDIENCE: What about the +constraint of constant PN T + +[INAUDIBLE]? + +PROFESSOR: OK. + +Actually, constraint +of constant PN T + +is important because +we said that said there + +it is a kind of +Gibbs-Duhem relation. + +And the Gibbs-Duhem +relation tells me + +for the case of the gas that +the S dT minus V dP plus N d mu + +is 0. + +And that constraint +is the one that + +tells me that once you have +set P and T, which are the two + +variables that I have specified +here, you also know mu. + +That is, you know all +the intensive quantities. + +So once you set PN T-- the +constraints over there-- + +really, the only thing +that you don't know + +is how big the system is. + +And that's what's the condition +that I used over here. + +But it is only-- so +let me re-emphasize + +it this way-- I +will write dV by dN + +is the same thing as V over +N, only if I have PN T here. + +If I had here PN S, for example, +I wouldn't be able to use this. + +I was going to +build this equation + +to say, look at the +elements of this. + +This part we got +from the first law, + +the temperature we got +from the zeroth law, + +and this we got from the +second law, which is correct, + +but it leaves out +something, which + +is that what the second +law had was things + +going some particular direction. + +And in particular, we had +that for the certain changes + +that I won't repeat, the change +in entropy to be positive. + +So when you are in +equilibrium, you + +have this relationship between +equilibrium state functions. + +But in fact, the second +law of thermodynamics + +tells you a little +bit more than that. + +So the next item that +we are going to look at + +is, what are the +consequences of having + +underlying this equality +between functions + +of state some kind of an +inequality about certain things + +being possible and things +not being possible? + +And that relates to +stability conditions. + +And I find it easier to +again introduce to you these + +stability conditions by thinking +of a mechanical analogue. + +So let's imagine that you +have some kind of a spring, + +and that this spring has some +kind of a potential energy + +that I will call phi as a +function of the extension x. + +And let's say that it's +some non-linear function + +such as this. + +There is no reason why we +should use a hook and spring, + +but something like this. + +Now, we also discussed +last time what + +happens if I were to pull +on this with some force J. + +So I pull on this. + +As a result, presumably +it will no longer + +be sitting at x, because +what I need to do + +is to minimize something else-- +the function that we call H-- + +which was the potential +energy of the spring + +plus the entity that +was exerting the force. + +So if I were to make it +in the vertical direction, + +you can imagine this as +being the potential energy + +of the mass that was +pulling on the spring. + +So what that means is +that in the presence of J, + +what I need to do is +to find the x that + +minimizes this expression. + +Once essentially the kinetic +energy has disappeared, + +my spring stops oscillating +and goes to a particular value. + +And mathematically, +that corresponds + +to subtracting a linear +function from this. + +Actually, what +will it look like? + +Let's not make this go flat, +but go up in some linear fashion + +so that at least I can +draw something like this. + +So what I need to do +is to minimize this. + +So I find that for +a given J, I have + +to solve d phi dx equals J. +But especially if you have + +a spring that has the kind of +potential that I drew for you, + +you start increasing +the-- so basically, + +what it says is that +you end up at the place + +where the slope is +equal to the derivative + +of the potential function. + +What happens if you start +increasing this slope, + +if it is a non-linear type +of thing, at some point + +you can see it's impossible. + +Essentially, it's like +a very flat noodle. + +You pull on it too much and then +it starts to expand forever. + +So essentially, this thing that +we are looking for a minimum, + +ultimately also +means that you need + +to have a condition on +the second derivative. + +d2 phi by dx squared better +be positive actually, + +I have to take d2 +H y dx squared. + +I took one derivative +to identify + +where the location of +the best solution is. + +If I take a second +derivative, this + +became essentially the +J. J is a constant. + +It only depends on +the potential energy. + +So it says independent of +the force that you apply. + +You know that if the shape of +the potential energy is given, + +the only places +that are accessible + +are the kinds of +places where you + +take the second +derivative and the second + +has a particular sign. + +So this portion of the +curve is in principle + +physically accessible. + +The portion that corresponds +to essentially changing + +the curvature and going the +other way, there's no way, + +there's no force +that you can put + +that would be able to access +those kinds of displacements. + +So there is this +convexity condition. + +This was for one variable. + +Now suppose you have multiple +variables-- x2, x3, et cetera. + +So you will have +the potential energy + +as a function of many variables. + +And the condition that you have +is that the second derivative + +of the potential with respect +to all variables, which forms-- + +and if there are n variables, +this would be an n by n matrix. + +This matrix is +positive definite. + +What that means is +that if you think + +of this as defining for you +the bottom of a potential, + +in whatever direction +you go, this + +would describe the change +of potential for you. + +The first order +change you already + +set to 0 because of the force J. +The second order change better + +be positive. + +So this is the condition that +you would have for stability, + +quite generally mechanically. + +And again, this +came from the fact + +that if you were +to exert a force, + +you would change the energy +by something like J delta + +x, which is certainly the +same thing that we have here. + +This is just one component +that I have been focusing on. + +And so ultimately, +I'm going to try + +to generalize that to this form. + +But one thing that I don't +quite like in this form + +is that I'm focusing too +much on the displacements. + +This is written appropriately +using this form. + +And we have seen over +here that whether or not + +I express things in terms +of the displacements + +or in terms of entropy, +temperature, conjugate forces, + +et cetera, these are +all equivalent ways + +of describing the +equilibrium system. + +So I'm going to do a +slight manipulation of this + +to make that symmetry between +forces and displacements + +apparent. + +So the generalization +of this expression + +that we have over +here is that once I + +know the potential +energy, the force + +in this multi-component +space is df by dxi. + +So in this multi-component +space, I have some J, + +and there's a corresponding x. + +They're related by this. + +Now, if I were to +make a change in J, + +there will be a change in the +position of the equilibrium. + +And I can get that by +doing a corresponding cange + +in the derivative. + +The corresponding +change in the derivative + +is the second derivative +of phi with respect + +to xi xj delta xj, sum +over J. So what I'm saying + +is that this is a +condition that relates + +the position to the forces. + +If I make a slight +change in the force, + +there will be a corresponding +slight change in the position. + +And the changes in the +position and the force given + +by this equilibrium condition +are related by this formula. + +Now, you can see that that +sum is already present here. + +So I can rewrite +the expression that + +is over here using that +formula as delta xi delta + +Ji, sum over i-- +better be positive. + +So this expression is slightly +different and better way + +of writing essentially the same +convexity condition, stability + +condition, but in a +manner that treats + +the displacements and +the forces equivalently. + +And I'm going to +apply that to this + +and say that in +general, there will + +be more ways of +manipulating the energy + +of a thermodynamic system, and +that having the system reach + +to equilibrium requires +the generalization of this + +as a delta T delta S, plus +sum over i delta Ji delta xi, + +plus sum over alpha, +delta mu alpha, + +delta N alpha-- to be positive. + +And you may say I didn't +really derive this for you + +because I started from +mechanical equilibrium + +and stability condition +and generalized + +to the thermodynamic one. + +But really, if you go back +and I use this condition + +and do manipulations that +are compatible to this, + +you will come up with exactly +this stability condition. + +And I have that in the notes. + +It is somewhat more +mathematically complicated + +than this, because the +derivatives involve + +additional factors +of 1 over T. And you + +have to do slightly more +work, but you will ultimately + +come with the same expression. + +OK? + +You say, why is that of any use? + +It is possible +that you've already + +seen a particular use +of this expression. + +Let's look at the case +of a gas-- one component. + +You would say that the +condition that we have + +is that delta T delta S minus +delta P delta V plus delta mu + +delta N has to be positive. + +Let's even be simpler. + +Look at the case +where delta T is 0, + +delta N equals to 0, which +means that I have a fixed + +amount of gas at a +particular temperature. + +So I could have, +for example, a box + +in this room which +is in equilibrium + +at the same temperature as +the temperature of the room. + +But its volume I'm +allowed to adjust + +so that the pressure changes. + +So in that process, at a +particular temperature, + +I will be finding a particular +curve in the pressure volume + +space. + +And the reason that I +drew this particular way + +is because I have the condition +that minus dP dV better + +be positive, so that if I +have P as a function of V, + +then I know that dP +is dP by dV delta V. + +And if the product +dP dV is positive, + +then this derivative dP +by dV has to be negative. + +This has to be a +decreasing function. + +And another way +of saying that is + +that the compressibility-- +kappa T, which is minus 1 + +over V, the inverse of this +dV by dP at constant T-- + +has to be positive. + +So this is a curve where +dP by dV is negative. + +Fine, you say. + +Nothing surprising about that. + +Well, it turns out that +if you cool the gas, + +the shape of this +isotherm can change. + +It can get started. + +And there is a critical +isotherm at which + +you see a condition such +as this, where there's + +a point where the curve +comes with 0 slope. + +So you say that for that +particular critical isotherm + +occurring at TC, if I were +to make this expansion, + +the first term in +this expansion is 0. + +You say, OK, let's continue and +write down the second term-- + +1/2 d2 P by dV squared +at constant P times + +delta V squared. + +Now the problem is +that if I multiply this + +by delta V-- which would have +made this into delta V squared + +and then this into +delta V cubed-- + +I have a problem +because delta V can + +be both positive or negative. + +I can go one direction +or the other direction. + +And a term that is a +cubic can change sign-- + +can sometimes be positive, +can sometimes be negative, + +depending on the sign of that. + +And that is disallowed +by this condition. + +So that would say that if +an analytical expression + +for the expansion exists, the +second derivative has to be 0. + +And then you would have +to go to the next term-- d + +cubed P dV cubed. + +And then delta V-- you would +normally write delta V cubed, + +but then I've multiplied by +delta V on the other side. + +We'd have delta V to the fourth. + +Delta V to the fourth you would +say is definitely positive. + +Then I can get things done +by having to make sure + +that the third +derivative is negative. + +And you say, OK, exactly +what have you done here? + +What you have done +here is you've + +drawn a curve that +locally looks like a cubic + +with the appropriate sign. + +And so that's certainly +true that if you + +have an isotherm there the +compressibility diverges, + +you have a condition +on second derivatives. + +And you probably have used this +for calculating critical points + +of van der Waals +and other gases. + +And we will do that ourselves. + +But it's actually not the +right way to go about, + +because when you go and look +at things experimentally + +with sufficient detail, you find +that these curves at this point + +are not analytic. + +They don't admit a +Taylor expansion. + +So while this +condition is correct, + +that the shape should +be something like this, + +it is neither cubic +nor a fifth power, + +but some kind of a +non-analytic curve. + +AUDIENCE: Could you +repeat last statement? + +PROFESSOR: That +statement, in order + +to fully understand +and appreciate, + +you have to come +to next term, where + +we talk about phase transitions. + +But the statement +is that the shape + +of the function in the +vicinity of something like this + +is delta P is +proportional to delta V + +to some other gamma that is +neither 3 nor 5 nor an integer. + +It is some number +that experimentally + +has been determined to be of +the order of, I don't know, 4.7. + +And why it is 4.7 you have to +do a lot of interesting field + +theory to understand. + +And hopefully, you'll come next +semester and I'll explain it. + +AUDIENCE: So your point is +that gamma is not [INAUDIBLE]. + +PROFESSOR: Gamma is not-- so +the statement is, in order + +for me to write this +curve as something delta V + +plus some other thing-- +delta V Squared-- + +plus some other +thing-- delta V cubed-- + +which we do all the time, +there is an inherent assumption + +that an analytical expansion +is possible around this point. + +Whereas if I gave you a +function y that is x to the 5/3, + +around x of 0, you cannot +write a Taylor series for it. + +OK? + +Essentially, this +stability condition + +tells you a lot of things about +signs of response functions. + +In the case of +mechanical cases, it + +is really that if +you have a spring, + +you better have a force +constant that is positive, + +so that when you pull on it, +the change in displacement + +has the right sign. + +It wants to be contracted. + +And similarly here, +you are essentially + +compressing the gas. + +There's a thermal analogue of +that sine which is worth making + +sure we know. + +Let's look at the +case where we have + +a fixed number of particles. + +And then what we would +have is that our dE + +is T dS plus Ji dxi. + +I am free to choose +any set of variables. + +The interesting set of +variables-- well, OK. + +So then stability implies +that delta T delta + +S plus delta Ji delta xi with +the sum over i is positive. + +Now, I can take a look +at this expression + +and choose any set of variables +to express these changes + +in terms of. + +So I'm going to choose for my +variables temperature and xi. + +You see, the way that +I've written it here, + +S, T, J, x appear +completely equivalently. + +I could have chosen +to express things + +in terms of S and +J, T and J, S and x. + +But I choose to use T and x. + +All right, so what +does that mean? + +It means that I write my +delta S in terms of dS + +by dT at constant x dT, +plus dS by dxi at constant T + +and other xj not +equal to i, delta xi. + +I also need an expression +for delta Ji here. + +so my delta Ji +would be dJi by dT + +at constant x, delta T, +plus dJi with respect + +to xj at constant T, an +appropriate set of J's, + +delta xi-- delta xj. + +Sum over J implicit here. + +I substitute these-- +delta S and delta J-- + +in the general form of +the stability condition + +to get constraints +applicable to combinations + +involving delta T and delta x. + +So I have to multiply +delta S with delta T. + +I have to multiply delta +Ji with delta xi here. + +Yes? + +AUDIENCE: So here, +J is not equal to i. + +And then which one is J? + +[INAUDIBLE] + +PROFESSOR: OK. + +So let's say that I have S +that is a function of-- I + +have x1 and x2. + +So here, I would +have derivatives + +dS by dx1 times delta x1. + +I would have derivatives +dS by dx2 times delta x2. + +In both cases, T is kept fixed. + +In this case, additionally, +x2 is kept fixed. + +In this case, additionally, +x1 is kept fixed. + +That's all. + +OK? + +So let's do that multiplication. + +We multiply a delta T here and +we get dS by dT at constant x, + +delta T squared. + +We get here a term which is +delta T delta xi, multiplying + +dS by dxi at constant +T, and the others + +that I don't bother to write. + +But I note that I will +get another term that + +is delta xi delta t from the +second term, whose coefficient + +is dJi by dT at constant x. + +And I group those +two terms together. + +And finally, we have +the last term here, + +which is delta xi delta +xj, dJi by dxj, constant T. + +And the constraint for all +of these stability conditions + +that I have written, +I have to be + +in the minimum of a potential. + +Any deviation that +I make better lead + +to an increase in this +combination, which + +is kind of equivalent +to being at the minimum + +of some kind of +potential energy. + +If you do some +manipulations, this + +is also equivalent to +being at the maximum + +of some entropy function. + +Now, let's look at that +manipulation a little bit. + +Now, I happen to know +that this form will + +simplify a little bit. + +And that's why I chose this +combination of variables. + +And the simplification +that will happen + +is that this entity is 0. + +So let me show you +why that entity is 0. + +And that relies on one of +these Maxwell relationships + +that I had. + +So let's find the +Maxwell relation that + +is applicable to dS by +dxi at constant T, which + +is what I have over here. + +OK, let's again start with +dE being T dS plus ji dxi. + +I'm at fixed number +of particles. + +I don't need to write +the other term-- UDN. + +Unfortunately here, S is +not the first derivative. + +So what I will do is I +will look at E minus TS. + +That's going to turn +this into minus S dT. + +Good. + +Ji dxi is exactly what I want +because this will tell me + +something about the +derivative in this fashion. + +dS by dxi at constant +T is equal to what? + +It's taking the things +in this fashion, + +which is dJi by +dT at constant x. + +Good. + +So I can see that the sum +total of these two terms is 0. + +And that's exactly +what I have here. + +So this is 0 by +Maxwell relation. + +OK? + +OK + +So having set that to +0, I have two terms. + +One of them is this entity +that goes with delta T squared. + +And the other is this entity-- +sum over i and J, delta xi, + +delta xj, dJi, dxj, +constant T. And this-- + +for any choice of delta x's +and delta T's-- for any choice, + +it better be positive. + +So in particular, +given this nice form + +that I have over +here, I can certainly + +choose all of the delta x's +to be 0, because I do things + +at constant displacement. + +And then what I have +is that the whole thing + +is proportional to delta T +squared and some coefficient. + +So that coefficient +better be positive. + +So entropy should always +be an increasing function + +of temperature at +constant displacement. + +And the consequence of that is +that heat capacities measure + +at constant displacement. + +So this is the +heat capacity-- Cx. + +The general definition is +you put some amount of heat + +into the system at +constant displacement. + +So I have to specify +the procedure + +by which heat is +applied to the system + +and see how much this +temperature changes. + +I can in principle do this +sufficiently stability + +so I can measure precisely +the changes in temperature + +infinitesimally. + +And then I can use +the relationship + +between dQ and reversible +heat-- so dS at constant x dT. + +And dS by dT at constant +x is precisely the entity + +that we have looked +at-- to be positive. + +So in the same way that a spring +is stable-- if you pull on it, + +its extension should +increase a little bit. + +And so the coefficient +that relates + +the change in +displacement corresponding + +to the change in force has +to be positive for stability. + +Heat capacities must have +this positivity in the sense + +that if you add +heat to a system, + +its temperature should go up. + +It it went the other way, it +would actually also violate + +the second law of +thermodynamics. + +Yes? + +AUDIENCE: I'm a bit confused +about the J notation + +that we used. + +The initial equation +that we start + +has only-- it deals with i, +but where does J come from? + +PROFESSOR: This equation. + +Which equation? + +Up here? + +AUDIENCE: So index J is +just a dummy variable? + +[INAUDIBLE] that dE +equals T dS equals Ji dSi. + +PROFESSOR: OK. + +Fine. + +So let's start from here. + +And part of the confusion is +that I'm not really consistent. + +Whenever I write an +index that is repeated, + +there is a so-called +summation convention + +that you may have seen +in quantum mechanics + +and other courses which +says that the index that + +is repeated twice +is summed over. + +So when I write ai bi, using +the summation convention, what + +I mean is, sum over all +possible values of i, ai, bi. + +So what I meant +here is that there + +may be multiple ways of +doing work on the system. + +So there could be pressure, +there could be spring, + +there could be magnetic work. + +And if I do mechanical +work on the system, + +the change in energy is the +sum total of all different ways + +to do mechanical +works, plus the heat + +that is supplied to the system. + +So that's statement number one. + +Now, I did something +else here, which + +is that when I take a derivative +of a function that depends + +on multiple variables-- so +f depends on x1, x2, x3, + +xn-- then if I look +at the change in this, + +any one of these +variables can change + +by an amount that is dxi. + +And if the second +variable changes, + +there is a corresponding +contribution, + +which is df with respect +to the second variable. + +And I have to add all of +these things together. + +So if I'm again +inconsistent, this + +is really what I +mean, that when you + +do a change in a function +of multiple variables, + +you would write it +as dxi, df by dxi. + +If you use the +summation convention, + +I have to really sum +over all possibilities. + +Now, suppose I took one of +these things, like df by dx3. + +So it's one of the +derivatives here. + +And I took another derivative, +or I looked at the change + +in this function. + +This function depends also +on variables x1 through xn. + +So I have to look at the sum +over all changes with respect + +to xj of df by dx3 delta xj. + +So you can see that +automatically, I + +have kind of assumed +some of these things + +as I write things rapidly. + +And if it is not clear, you have +to spend a little bit of time + +writing things more in +detail, because it's + +after all kind of +simple algebra. + +Yes, did I make another mistake? + +Yes? + +AUDIENCE: Oh, not +a mistake, just-- + +PROFESSOR: Yes? + +AUDIENCE: When you were +talking about mechanicals, + +you had a non-linear spring. + +You start pulling on it. + +At some point, it +just increases. + +PROFESSOR: If it is a non-linear +spring, yes, that's right. + +AUDIENCE: Can you provide +example of thermodynamic system + +which, upon some +threshold action upon it, + +becomes unstable? + +PROFESSOR: OK. + +I think I more or +less had that example. + +Let's try to develop it +a little bit further. + +So I said that typically, if +I look at the pressure volume + +isotherms of a gas, it +looks something like this. + +And I told you that +there is actually + +some kind of a critical isotherm +that looks something like this. + +And you may ask, +well, what do things + +look below that for +lower temperatures? + +And again, you +probably know this, + +is that this is the +temperature below which + +you have a transition to +liquid gas coexistence. + +And so the isotherms +would look like that. + +Now, it turns out that while +these are true equilibrium + +things-- you would have +to wait sufficiently long + +so that the system +explores these isotherms-- + +it is also possible +in certain systems + +to do things a little +bit more rapidly. + +And then when you +go below, you will + +see a kind of remnant of that +isotherm which kind of looks + +like this. + +So that isotherm would +have portions of it + +that don't satisfy these +conditions of stability. + +And the reason that you still +get some remnant of it-- + +not quite the entire thing. + +You get actually +some portion here, + +some portion here-- is because +you do things very rapidly + +and the system +does not have time + +to explore the +entire equilibrium. + +So that's one example +that I can think + +of where some remnants +of something that + +is like that non-linear +noodle takes place. + +But even the non-linear +noodle, you cannot really see + +in equilibrium. + +You can only see it +when you're pulling it. + +And you can see that +it is being extended. + +There is no equilibrium that +you can see that has that. + +So if I want to find an analogue +of that non-linear noodle + +showing instability, I'd better +find some near-equilibrium + +condition. + +And this is the near-equilibrium +condition that I can think of. + +There are a number of cases. + +And essentially, you've +probably heard hysteresis + +in magnets and things like that. + +And by definition, +hysteresis means + +that for the same +set of conditions, + +you see multiple +different states. + +So not both of them can +be or multiple of them + +can be in equilibrium. + +And over some +sufficient time scale, + +you would go from one +behavior to another behavior. + +But if you explore the vicinity +of the curves that correspond + +to these hysteretic +behavior, you + +would see the signatures +of these kinds + +of thermodynamic instabilities. + +There was one other part +of this that maybe I + +will write a little bit +in more detail, given + +the questions that were. + +Asked It is here I looked +at this general condition + +for the case where +the delta x's were 0. + +Let's look at the same +thing for the case + +where delta T equals +to 0, because then I + +have the condition that +the Ji by the xj, delta xi, + +delta xj should be positive. + +And this was done at constant T. + +And to be more explicit, there +is a sum over i and J in here. + +So if I'm doing things +at constant temperature, + +I really have the analogue +of the instability condition. + +What I have here, it is +the same thing as this one. + +And if you think about this +in a little bit more detail-- + +let's say I have +something like a gas. + +We have two ways of +doing work on the system. + +I have dJ1 by dx1. + +I have dJ2 by dx2. + +I have dJ1 by dx2. + +I have dj2 by dx1. + +Essentially, this object, +there are four of them. + +And those four I can put +into something like this. + +And the statement +that I have written + +is that this 2 by +2 matrix, if it + +acts on the displacement delta +x1 delta x2 on the right, + +and then gets contracted on the +left by the same vector delta + +x1, delta x2, for any +choice of the vector delta + +x1 delta x2, this +better be positive. + +This is for two, but in +general, this expression + +is going to be valid +for any number. + +Now, what are the constraints +that a matrix must satisfy + +so that irrespective of the +choice of this displacement, + +you will get a positive result? + +Mathematically, that's caused +a positive definite matrix. + +So one of the conditions that +is certainly immediately obvious + +is that if I choose the case +where delta x2 is 0, then + +the diagonal term +that corresponds + +to that entity +better be positive. + +So a matrix is positive +definite if for every one + +of the diagonal elements, +I have this condition. + +So this is actually something +that we already saw. + +In the case of the +gas, this would + +be something like minus dP by +dV at constant temperature-- + +be positive. + +This is the nature of +these isotherms always + +going one way that +I was drawing. + +AUDIENCE: Question. + +PROFESSOR: Yes. + +AUDIENCE: You're not summing +over alpha now, are you? + +Or are you-- + +PROFESSOR: Yes, I'm not. + +And I don't know how +to write. [LAUGHS] + +Let's call it delta J1, x1. + +So all diagonal elements +must be positive, + +but that's not enough. + +So I can write a matrix that +has only positive elements + +along the diagonal, but +off-diagonal elements such + +that the combination +will give you + +negative values of +this culmination + +for appropriate choices +of delta x1 and delta x2. + +The thing that +you really need is + +that all eigenvalues +must be positive. + +It is not that easy to +write down mathematically + +in general what that means +in terms of multiple response + +functions. + +That's why this +form of writing is + +much more compact and effective. + +It basically says, no matter +what combination of elements + +you choose, you are at the +bottom of the potential. + +You should not be able +to go away from it. + +AUDIENCE: So the +second statement + +is necessary and +sufficient condition? + +PROFESSOR: This statement is +necessary but not sufficient. + +This statement is +equivalent to the meaning + +of what is a positive +definite matrix. + +It is sufficient. + +Yes? + +AUDIENCE: Is there any +physical interpretation + +to diagonalizing that matrix? + +PROFESSOR: It depends on +the kind of the formations + +that you make. + +Like if I was really +thinking about a gas + +where I allow some exchange +with the surface or something + +else so that delta +N is not equal to 0, + +the general form of this +matrix in the case where + +I have pressure volume would +be something like this. + +I would have minus dP by dV. + +I would have d mu by dN. + +I would have dP by dN. + +I would have d mu by dV. + +And I would have to make sure +that this matrix is positive + +definite, so I know certainly +that the compressibility + +by itself has to be positive. + +d mu by dN also +has to be positive. + +But if I allow +changes both in volume + +and the number of +particles, then because + +of these off-diagonal terms, +I have additional constraints. + +So for appropriate +changes, it is + +sufficient to look at +the diagonal terms. + +But for the entire set of +possible transformations, + +it's not. + +Yes? + +AUDIENCE: If you look at +different ways to do the work + +on the system-- so in +this case, change volume, + +change number of particles, +if you're saying forces have + +different dimensions, and +if diagonalization of these + +metrics corresponds to inventing +some new ways of acting + +on the system which are a linear +combination of old ways like + +change volume a little +and change particles-- + +PROFESSOR: Change the +number of particles, yes. + +AUDIENCE: Those are pretty +weird manipulations, + +in terms of how to +physically explain + +what is diagonalization matrix. + +PROFESSOR: OK. + +There is a question +of dimensions, + +and there's a +question of amount. + +So maybe what you +are worried about + +is that if I make one them +volume and the other pressure, + +one is extensive, +one is intensive, + +and the response +functions would have + +to carry something that +is proportional to size. + +But then there are +other conditions, + +let's say, where all of the +variables are intensive. + +And then it's moving +around in the space that + +is characterized, let's say, by +pressure and chemical potential + +from one point to another point. + +And there is some generalized +response that you would have, + +depending on which +direction you go to. + +So essentially, +I could certainly + +characterize various +thermodynamic functions + +in this space P mu. + +And what I know is that I cannot +write any function in this + +two-parameter space that +would be consistent with + +the thermodynamic +principles of stability. + +I have to have some +kind of convexity. + +So certainly, what +typically-- let's say again, + +going back to my favorite +example here-- what people do + +and what we will +do later on is we + +specify that you have +some particular pressure + +and volume of an +interacting gas. + +And there is no way +that we can calculate + +the thermodynamic properties +of that system exactly. + +We try to construct +a free energy + +as a function of +these variables. + +And that free energy +will be approximate based + +on some ideas. + +And then we will see that that +free energy that I construct + +in some places will violate +the conditions of stability. + +And then I know that that free +energy that I constructed, + +let's say on the assumption +that the box that I have + +is uniformly covered +by some material, + +that assumption is violated. + +And maybe what has happened +is that part of the volume + +is a liquid and part +of the volume is gas. + +So we will do precisely +that exercise later on. + +We will choose a +pair of variables. + +We will try to construct a +free energy function out. + +We make the assumption that +the box is uniformly occupied + +with the gas at some density. + +Based on that, we estimate its +energy, entropy, et cetera. + +We construct a free +energy function out. + +And then we will see that +that energy function violates + +the compressibility +condition at some point. + +So we know that, oh, +we made a mistake. + +The assumption that it is +uniformly occupying this box + +is wrong. + +All right, any other questions? + +Yes? + +AUDIENCE: One of the +things that confuses me + +about thermodynamics +in general is + +the limits of its applicability. + +We think of it as +being very general, + +applying to many +different systems. + +For example, if we +had two bar magnets + +and we had the north pole +close to the south pole + +of the other one, and I +thought of the magnetic field + +in between, is it +conceivable to think + +of that as a +thermodynamic system? + +PROFESSOR: You can +think of the magnet + +as a thermodynamic system. + +And you can certainly +look at two of them, + +including the electromagnetic +field that surrounds them. + +And there would be +some conditions, + +like if you were to jiggle +these things with respect + +to each other-- and you would +maintain the entire thing + +in a box that prevented escape +of electromagnetic waves + +or heat to the outside-- +that eventually + +this jiggling of the two magnets +will lead to their coming + +to equilibrium but at +a higher temperature. + +So this is what I'm saying. + +So imagine that you have-- let's +for simplicity think of, again, + +one big magnet that +you don't move, + +and one small magnet here that +you externally jiggle around. + +And then you remove +the source of work. + +You wait for a while. + +And then you find +that after a while, + +this thing comes +to an equilibrium. + +You ask, where did that +kinetic energy go to? + +You had some kinetic energy +that you had set into this, + +and the kinetic +energy disappeared. + +And I assume that +there are conditions + +that the kinetic energy could +not have escaped from this box. + +So the only thing that +could have happened + +is that that kinetic +energy heated up + +the air of the box, the +magnet, or whatever you have. + +So thermodynamics is applicable +in that sense to your system. + +Now, if you ask me, is +it applicable to having + +a single electron spin +that is polarized because + +of the magnetic field +and some condition + +that I set it to oscillate, +then it's not applicable, + +because then I know some +quantum mechanical rules that + +govern this. + +There may be in +some circumstances + +some conservation law that says +this with oscillate forever. + +If it doesn't oscillate +forever, there's + +presumably a +transition matrix that + +says it will admit a particular +photon of a particular energy. + +And I have to ask what +happened to that photon. + +So what we will see later +on is that thermodynamics + +is very powerful, but it's +not a fundamental theory + +in this sense that +the quantum mechanics + +that governs the spins. + +And the reason that this works +for the case of the magnet + +is because the magnet has +billions of spins in it-- + +billions and billions +of spins, or whatever. + +So it is the of large +numbers that ultimately + +allows you to translate +the rules of motion + +into a well-defined +theory that is + +consistent with thermodynamics. + +AUDIENCE: I know that my +question seemed off-topic. + +But the reason why I asked +about this particular system + +is because I would +think that it doesn't + +have a positive compressibility. + +Like if you pull the two +magnets apart very slowly, + +the force pulling them +together decreases + +instead of increasing +like with the rubber band. + +PROFESSOR: OK. + +It may be that you have to +add additional agents in order + +to make the whole system work. + +So it may be that the +picture that I had in mind + +was that you have +the magnet that + +is being pushed up and down. + +And I really do put +a number of springs + +that make sure there exists +an equilibrium position. + +If there is no mechanical +equilibrium position, + +then the story is not whether +or not to thermodynamic applies. + +It's a question of whether or +not there is an equilibrium. + +So in order for me to +talk about thermodynamics + +I need to know that there +is an eventual equilibrium. + +and that's why I actually recast +the answer to your question, + +eventually getting rid of +the kinetic energy of this + +so that I have a system +that is in equilibrium. + +If there are things that +are not in equilibrium, + +all bets are off. + +Thermodynamics is the science of +things that are in equilibrium. + +Other questions? + +All right, so there is only one +minor part of our description-- + +rapid survey of +thermodynamics-- that is left. + +And that's the third +law of thermodynamics + +and that has to do something +with the behavior of things + +as you go towards +the limit of the zero + +of thermodynamic temperature. + +And I think we will spend maybe +10, 15 minutes next lecture + +talking about the third +law of thermodynamics. + +Probably from my +perspective, that + +is enough time with +respect towards the time + +we spend on the other +laws of thermodynamics, + +because as I will +emphasize to you also, + +the third law of +thermodynamics is in some sense + +less valid than the others. + +It's certainly correct +and it is valid. + +It is just that its validity +rests on other things than what + +I was emphasizing +right now, which + +is the large number +of degrees of freedom. + +You could have a large +number of degrees + +of freedom in a world +that is governed + +by classic laws of physics, and +the third law of thermodynamics + +would be violated. + +So it is a condition +that we live + +in a world that is governed by +quantum mechanics that tells us + +about the third law, as +we will discuss next time. \ No newline at end of file diff --git a/b04CichdN5g.txt b/b04CichdN5g.txt new file mode 100644 index 0000000000000000000000000000000000000000..63449604ad29c444d8321f58cf60f70761021b5f --- /dev/null +++ b/b04CichdN5g.txt @@ -0,0 +1,987 @@ +align:start position:0% + +la + + align:start position:0% + + + + align:start position:0% + +good morning + + align:start position:0% +good morning + + + align:start position:0% +good morning +students morning Mr Su can anyone tell + + align:start position:0% +students morning Mr Su can anyone tell + + + align:start position:0% +students morning Mr Su can anyone tell +me the answer please I I can is + + align:start position:0% +me the answer please I I can is + + + align:start position:0% +me the answer please I I can is +everything clear yes perfectly clear are + + align:start position:0% +everything clear yes perfectly clear are + + + align:start position:0% +everything clear yes perfectly clear are +there any other + + align:start position:0% +there any other + + + align:start position:0% +there any other +questions no no questions I will see you + + align:start position:0% +questions no no questions I will see you + + + align:start position:0% +questions no no questions I will see you +on Tuesday thank + + align:start position:0% + + + + align:start position:0% + +you wait a minute that's not what + + align:start position:0% +you wait a minute that's not what + + + align:start position:0% +you wait a minute that's not what +happens in real life + + align:start position:0% +happens in real life + + + align:start position:0% +happens in real life +actual MIT undergraduates often come to + + align:start position:0% +actual MIT undergraduates often come to + + + align:start position:0% +actual MIT undergraduates often come to +class on 3 hours of + + align:start position:0% +class on 3 hours of + + + align:start position:0% +class on 3 hours of +sleep can anyone tell me the answer + + align:start position:0% +sleep can anyone tell me the answer + + + align:start position:0% +sleep can anyone tell me the answer +please sometimes they're afraid to + + align:start position:0% +please sometimes they're afraid to + + + align:start position:0% +please sometimes they're afraid to +volunteer what might be the wrong answer + + align:start position:0% +volunteer what might be the wrong answer + + + align:start position:0% +volunteer what might be the wrong answer +learn in lecture by considering a simple + + align:start position:0% +learn in lecture by considering a simple + + + align:start position:0% +learn in lecture by considering a simple +example they're not always paying + + align:start position:0% +example they're not always paying + + + align:start position:0% +example they're not always paying +attention + + align:start position:0% +attention + + + align:start position:0% +attention +what and they might not understand what + + align:start position:0% +what and they might not understand what + + + align:start position:0% +what and they might not understand what +you thought you explained well is + + align:start position:0% +you thought you explained well is + + + align:start position:0% +you thought you explained well is +everything clear + + align:start position:0% + + + + align:start position:0% + +so how can you be a successful ta at + + align:start position:0% +so how can you be a successful ta at + + + align:start position:0% +so how can you be a successful ta at +MIT try thinking of your class as a + + align:start position:0% +MIT try thinking of your class as a + + + align:start position:0% +MIT try thinking of your class as a +popular website that visitors come back + + align:start position:0% +popular website that visitors come back + + + align:start position:0% +popular website that visitors come back +to again and again what makes a website + + align:start position:0% +to again and again what makes a website + + + align:start position:0% +to again and again what makes a website +userfriendly user friendly to me means + + align:start position:0% +userfriendly user friendly to me means + + + align:start position:0% +userfriendly user friendly to me means +that um in order to complete the task at + + align:start 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website is a clear + + align:start position:0% +userfriendly website is a clear + + + align:start position:0% +userfriendly website is a clear +interface simple categories and a search + + align:start position:0% +interface simple categories and a search + + + align:start position:0% +interface simple categories and a search +option and an accessible language so + + align:start position:0% +option and an accessible language so + + + align:start position:0% +option and an accessible language so +being able to find things very + + align:start position:0% +being able to find things very + + + align:start position:0% +being able to find things very +efficiently and quickly is definitely + + align:start position:0% +efficiently and quickly is definitely + + + align:start position:0% +efficiently and quickly is definitely +pretty important I I think it's more + + align:start position:0% +pretty important I I think it's more + + + align:start position:0% +pretty important I I think it's more +user friendly when you can actually + + align:start position:0% +user friendly when you can actually + + + align:start position:0% +user friendly when you can actually +understand what you what they want you + + align:start position:0% +understand what you what they want you + + + align:start position:0% +understand what you what they want you +to do and where things are being able to + + align:start position:0% +to do and where things are being able to + + + align:start position:0% +to do and where things are being able to +find the right things um in a way that's + + align:start position:0% +find the right things um in a way that's + + + align:start position:0% +find the right things um in a way that's +easy in other words a userfriendly + + align:start position:0% +easy in other words a userfriendly + + + align:start position:0% +easy in other words a userfriendly +website should be designed uh with the + + align:start position:0% +website should be designed uh with the + + + align:start position:0% +website should be designed uh with the +with the thinking that to make the user + + align:start position:0% +with the thinking that to make the user + + + align:start position:0% +with the thinking that to make the user +feel happy and easy instead of making + + align:start position:0% +feel happy and easy instead of making + + + align:start position:0% +feel happy and easy instead of making +the computer Engineers to feel happy at + + align:start position:0% +the computer Engineers to feel happy at + + + align:start position:0% +the computer Engineers to feel happy at +the + + align:start position:0% +the + + + align:start position:0% +the +easy what if the engineer is a teacher + + align:start position:0% +easy what if the engineer is a teacher + + + align:start position:0% +easy what if the engineer is a teacher +and the user a + + align:start position:0% +and the user a + + + align:start position:0% +and the user a +student the main principle of + + align:start position:0% +student the main principle of + + + align:start position:0% +student the main principle of +accessibility should be the same a + + align:start position:0% +accessibility should be the same a + + + align:start position:0% +accessibility should be the same a +website should be simple clean and also + + align:start position:0% +website should be simple clean and also + + + align:start position:0% +website should be simple clean and also +like should have where you want to go + + align:start position:0% +like should have where you want to go + + + align:start position:0% +like should have where you want to go +right away and a teacher should be able + + align:start position:0% +right away and a teacher should be able + + + align:start position:0% +right away and a teacher should be able +to judge where the students need what + + align:start position:0% +to judge where the students need what + + + align:start position:0% +to judge where the students need what +the students needs where the students + + align:start position:0% +the students needs where the students + + + align:start position:0% +the students needs where the students +want to go and adapt in that way I guess + + align:start position:0% +want to go and adapt in that way I guess + + + align:start position:0% +want to go and adapt in that way I guess +like the search button would be asking + + align:start position:0% +like the search button would be asking + + + align:start position:0% +like the search button would be asking +the ti asking the professor for more + + align:start position:0% +the ti asking the professor for more + + + align:start position:0% +the ti asking the professor for more +information it's not necessarily that + + align:start position:0% +information it's not necessarily that + + + align:start position:0% +information it's not necessarily that +everyone is going to be your friend but + + align:start position:0% +everyone is going to be your friend but + + + align:start position:0% +everyone is going to be your friend but +it's more + + align:start position:0% +it's more + + + align:start position:0% +it's more +about being easy to understand in terms + + align:start position:0% +about being easy to understand in terms + + + align:start position:0% +about being easy to understand in terms +of having a clear interface just a + + align:start position:0% +of having a clear interface just a + + + align:start position:0% +of having a clear interface just a +simple structure of the class something + + align:start position:0% +simple structure of the class something + + + align:start position:0% +simple structure of the class something +students can expect like the lecture + + align:start position:0% +students can expect like the lecture + + + align:start position:0% +students can expect like the lecture +goes the lectures go the same way the + + align:start position:0% +goes the lectures go the same way the + + + align:start position:0% +goes the lectures go the same way the +recitation go the same way and something + + align:start position:0% +recitation go the same way and something + + + align:start position:0% +recitation go the same way and something +that students can expect so organization + + align:start position:0% +that students can expect so organization + + + align:start position:0% +that students can expect so organization +and predictability are key to the + + align:start position:0% +and predictability are key to the + + + align:start position:0% +and predictability are key to the +userfriendly class but um planning that + + align:start position:0% +userfriendly class but um planning that + + + align:start position:0% +userfriendly class but um planning that +way in The Logical session where you + + align:start position:0% +way in The Logical session where you + + + align:start position:0% +way in The Logical session where you +like review the things that are + + align:start position:0% +like review the things that are + + + align:start position:0% +like review the things that are +necessary and then um going into problem + + align:start position:0% +necessary and then um going into problem + + + align:start position:0% +necessary and then um going into problem +practice problems and then going into um + + align:start position:0% +practice problems and then going into um + + + align:start position:0% +practice problems and then going into um +going over what were the right answers I + + align:start position:0% +going over what were the right answers I + + + align:start position:0% +going over what were the right answers I +thought that was like pretty user + + align:start position:0% +thought that was like pretty user + + + align:start position:0% +thought that was like pretty user +friendly for a student cuz um it was a + + align:start position:0% +friendly for a student cuz um it was a + + + align:start position:0% +friendly for a student cuz um it was a +good review and then get practice so + + align:start position:0% +good review and then get practice so + + + align:start position:0% +good review and then get practice so +it's like logical for today's recitation + + align:start position:0% +it's like logical for today's recitation + + + align:start position:0% +it's like logical for today's recitation +we're going to do the TA acts as a guide + + align:start position:0% +we're going to do the TA acts as a guide + + + align:start position:0% +we're going to do the TA acts as a guide +for the students it's important + + align:start position:0% +for the students it's important + + + align:start position:0% +for the students it's important +to ex well explain the learning + + align:start position:0% +to ex well explain the learning + + + align:start position:0% +to ex well explain the learning +objectives of the class earlier on have + + align:start position:0% +objectives of the class earlier on have + + + align:start position:0% +objectives of the class earlier on have +just like an air of confidence and be + + align:start position:0% +just like an air of confidence and be + + + align:start position:0% +just like an air of confidence and be +able to direct the recitation a very big + + align:start position:0% +able to direct the recitation a very big + + + align:start position:0% +able to direct the recitation a very big +expectation in a recitation is for the + + align:start position:0% +expectation in a recitation is for the + + + align:start position:0% +expectation in a recitation is for the +TA to provide us with the big picture of + + align:start position:0% +TA to provide us with the big picture of + + + align:start position:0% +TA to provide us with the big picture of +the concepts you know the TA is + + align:start position:0% +the concepts you know the TA is + + + align:start position:0% +the concepts you know the TA is +approachable and supportive you need to + + align:start position:0% +approachable and supportive you need to + + + align:start position:0% +approachable and supportive you need to +feel that you can approach them and ask + + align:start position:0% +feel that you can approach them and ask + + + align:start position:0% +feel that you can approach them and ask +questions without any problem and + + align:start position:0% +questions without any problem and + + + align:start position:0% +questions without any problem and +knowledgeable the most important thing + + align:start position:0% +knowledgeable the most important thing + + + align:start position:0% +knowledgeable the most important thing +for um a TA is that they have to have a + + align:start position:0% +for um a TA is that they have to have a + + + align:start position:0% +for um a TA is that they have to have a +very solid understanding of what's going + + align:start position:0% +very solid understanding of what's going + + + align:start position:0% +very solid understanding of what's going +on um in the material but is knowledge + + align:start position:0% +on um in the material but is knowledge + + + align:start position:0% +on um in the material but is knowledge +enough unfortunately it's not enough to + + align:start position:0% +enough unfortunately it's not enough to + + + align:start position:0% +enough unfortunately it's not enough to +Simply Be knowledgeable about the + + align:start position:0% +Simply Be knowledgeable about the + + + align:start position:0% +Simply Be knowledgeable about the +subject it's the way you presented the + + align:start position:0% +subject it's the way you presented the + + + align:start position:0% +subject it's the way you presented the +way it communicated they're all very + + align:start position:0% +way it communicated they're all very + + + align:start position:0% +way it communicated they're all very +smart I know they all know what they're + + align:start position:0% +smart I know they all know what they're + + + align:start position:0% +smart I know they all know what they're +talking about so it's just how they can + + align:start position:0% +talking about so it's just how they can + + + align:start position:0% +talking about so it's just how they can +communicate that to us so what is good + + align:start position:0% +communicate that to us so what is good + + + align:start position:0% +communicate that to us so what is good +communication in the userfriendly + + align:start position:0% +communication in the userfriendly + + + align:start position:0% +communication in the userfriendly +classroom the biggest thing that came + + align:start position:0% +classroom the biggest thing that came + + + align:start position:0% +classroom the biggest thing that came +across my mind was definitely like how + + align:start position:0% +across my mind was definitely like how + + + align:start position:0% +across my mind was definitely like how +they uh answered questions and like the + + align:start position:0% +they uh answered questions and like the + + + align:start position:0% +they uh answered questions and like the +feedback they got from the students and + + align:start position:0% +feedback they got from the students and + + + align:start position:0% +feedback they got from the students and +how they responded to that it's not the + + align:start position:0% +how they responded to that it's not the + + + align:start position:0% +how they responded to that it's not the +same when they read a paper and they + + align:start position:0% +same when they read a paper and they + + + align:start position:0% +same when they read a paper and they +just write the problem in the board and + + align:start position:0% +just write the problem in the board and + + + align:start position:0% +just write the problem in the board and +solve the problem than explaining why is + + align:start position:0% +solve the problem than explaining why is + + + align:start position:0% +solve the problem than explaining why is +it going like this or why is it working + + align:start position:0% +it going like this or why is it working + + + align:start position:0% +it going like this or why is it working +like this I think um just the + + align:start position:0% +like this I think um just the + + + align:start position:0% +like this I think um just the +willingness to clarify is very very + + align:start position:0% +willingness to clarify is very very + + + align:start position:0% +willingness to clarify is very very +important being patient and being able + + align:start position:0% +important being patient and being able + + + align:start position:0% +important being patient and being able +to explain the same concept in different + + align:start position:0% +to explain the same concept in different + + + align:start position:0% +to explain the same concept in different +ways and they can actually explain it to + + align:start position:0% +ways and they can actually explain it to + + + align:start position:0% +ways and they can actually explain it to +you at a basic undergrad level in the + + align:start position:0% +you at a basic undergrad level in the + + + align:start position:0% +you at a basic undergrad level in the +next videos we will learn communication + + align:start position:0% +next videos we will learn communication + + + align:start position:0% +next videos we will learn communication +skills and strategies to meet students + + align:start position:0% +skills and strategies to meet students + + + align:start position:0% +skills and strategies to meet students +expectations and create a userfriendly + + align:start position:0% +expectations and create a userfriendly + + + align:start position:0% +expectations and create a userfriendly +classroom \ No newline at end of file diff --git a/b0VqqwHLqcI.txt b/b0VqqwHLqcI.txt new file mode 100644 index 0000000000000000000000000000000000000000..39fb2348e54c32fd76bcadd6cc2ae0aeaf9a26d7 --- /dev/null +++ b/b0VqqwHLqcI.txt @@ -0,0 +1,19752 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +to view additional materials from + + align:start position:0% +to view additional materials from + + + align:start position:0% +to view additional materials from +hundreds of MIT courses visit MIT + + align:start position:0% +hundreds of MIT courses visit MIT + + + align:start position:0% +hundreds of MIT courses visit MIT +opencourseware at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu let's talk about the uh V + + align:start position:0% +ocw.mit.edu let's talk about the uh V + + + align:start position:0% +ocw.mit.edu let's talk about the uh V +model here we are interesting we have a + + align:start position:0% +model here we are interesting we have a + + + align:start position:0% +model here we are interesting we have a +little bit of a lag here so the um life + + align:start position:0% +little bit of a lag here so the um life + + + align:start position:0% +little bit of a lag here so the um life +cycle management essentially is our last + + align:start position:0% +cycle management essentially is our last + + + align:start position:0% +cycle management essentially is our last +topic for today and that sort of + + align:start position:0% +topic for today and that sort of + + + align:start position:0% +topic for today and that sort of +completes the the V and then + + align:start position:0% +completes the the V and then + + + align:start position:0% +completes the the V and then +next + + align:start position:0% +next + + + align:start position:0% +next +manufacturing so what I'd like to cover + + align:start position:0% +manufacturing so what I'd like to cover + + + align:start position:0% +manufacturing so what I'd like to cover +today is essentially a definition of + + align:start position:0% +today is essentially a definition of + + + align:start position:0% +today is essentially a definition of +management what does it include what do + + align:start position:0% +management what does it include what do + + + align:start position:0% +management what does it include what do +we mean by that and then focus on the + + align:start position:0% +we mean by that and then focus on the + + + align:start position:0% +we mean by that and then focus on the +life cycle properties also known as the + + align:start position:0% +life cycle properties also known as the + + + align:start position:0% +life cycle properties also known as the +IL um discuss a little bit where they + + align:start position:0% +IL um discuss a little bit where they + + + align:start position:0% +IL um discuss a little bit where they +come from how much we know about them + + align:start position:0% +come from how much we know about them + + + align:start position:0% +come from how much we know about them +then the bulk of the discussion is going + + align:start position:0% +then the bulk of the discussion is going + + + align:start position:0% +then the bulk of the discussion is going +to be a case study called + + align:start position:0% +to be a case study called + + + align:start position:0% +to be a case study called +reconfiguration communication satellite + + align:start position:0% +reconfiguration communication satellite + + + align:start position:0% +reconfiguration communication satellite +constellations and this sort of explains + + align:start position:0% +constellations and this sort of explains + + + align:start position:0% +constellations and this sort of explains +the idea that a system once you brought + + align:start position:0% +the idea that a system once you brought + + + align:start position:0% +the idea that a system once you brought +a system into operation that's not the + + align:start position:0% +a system into operation that's not the + + + align:start position:0% +a system into operation that's not the +end of the story that system is going to + + align:start position:0% +end of the story that system is going to + + + align:start position:0% +end of the story that system is going to +continue to live and change and be + + align:start position:0% +continue to live and change and be + + + align:start position:0% +continue to live and change and be +modified over its life uh I'll try to + + align:start position:0% +modified over its life uh I'll try to + + + align:start position:0% +modified over its life uh I'll try to +summarize some of the key concepts of + + align:start position:0% +summarize some of the key concepts of + + + align:start position:0% +summarize some of the key concepts of +the whole semester and then I have like + + align:start position:0% +the whole semester and then I have like + + + align:start position:0% +the whole semester and then I have like +one slide on career and study + + align:start position:0% +one slide on career and study + + + align:start position:0% +one slide on career and study +recommendations if you want to go + + align:start position:0% +recommendations if you want to go + + + align:start position:0% +recommendations if you want to go +further into systems + + align:start position:0% +further into systems + + + align:start position:0% +further into systems +engineering um so life cycle + + align:start position:0% +engineering um so life cycle + + + align:start position:0% +engineering um so life cycle +management um so this is my definition + + align:start position:0% +management um so this is my definition + + + align:start position:0% +management um so this is my definition +of what life cycle management is it's + + align:start position:0% +of what life cycle management is it's + + + align:start position:0% +of what life cycle management is it's +essentially the active engagement of + + align:start position:0% +essentially the active engagement of + + + align:start position:0% +essentially the active engagement of +it's the active engagement of all the + + align:start position:0% +it's the active engagement of all the + + + align:start position:0% +it's the active engagement of all the +stakeholders with the system between the + + align:start position:0% +stakeholders with the system between the + + + align:start position:0% +stakeholders with the system between the +time when it starts to operates you've + + align:start position:0% +time when it starts to operates you've + + + align:start position:0% +time when it starts to operates you've +done the commissioning you've done the + + align:start position:0% +done the commissioning you've done the + + + align:start position:0% +done the commissioning you've done the +operations until you decide to + + align:start position:0% +operations until you decide to + + + align:start position:0% +operations until you decide to +decommission retire the system so it's + + align:start position:0% +decommission retire the system so it's + + + align:start position:0% +decommission retire the system so it's +the during the whole operational life + + align:start position:0% +the during the whole operational life + + + align:start position:0% +the during the whole operational life +and what you want to do is you want to + + align:start position:0% +and what you want to do is you want to + + + align:start position:0% +and what you want to do is you want to +maximize the value that you gain from + + align:start position:0% +maximize the value that you gain from + + + align:start position:0% +maximize the value that you gain from +the system's existence and so uh life + + align:start position:0% +the system's existence and so uh life + + + align:start position:0% +the system's existence and so uh life +cycle management starts from the very + + align:start position:0% +cycle management starts from the very + + + align:start position:0% +cycle management starts from the very +very very start and so I listed here + + align:start position:0% +very very start and so I listed here + + + align:start position:0% +very very start and so I listed here +some activities that are included in + + align:start position:0% +some activities that are included in + + + align:start position:0% +some activities that are included in +life cycle management so obviously daily + + align:start position:0% +life cycle management so obviously daily + + + align:start position:0% +life cycle management so obviously daily +operations you know monitoring is the + + align:start position:0% +operations you know monitoring is the + + + align:start position:0% +operations you know monitoring is the +system working uh as expected uh + + align:start position:0% +system working uh as expected uh + + + align:start position:0% +system working uh as expected uh +training and certification of The + + align:start position:0% +training and certification of The + + + align:start position:0% +training and certification of The +Operators sometimes you know in long + + align:start position:0% +Operators sometimes you know in long + + + align:start position:0% +Operators sometimes you know in long +lived systems the people that were the + + align:start position:0% +lived systems the people that were the + + + align:start position:0% +lived systems the people that were the +early operators generation one are not + + align:start position:0% +early operators generation one are not + + + align:start position:0% +early operators generation one are not +necessarily the people who are going to + + align:start position:0% +necessarily the people who are going to + + + align:start position:0% +necessarily the people who are going to +operate for the whole life so you have + + align:start position:0% +operate for the whole life so you have + + + align:start position:0% +operate for the whole life so you have +to you know you have to have new people + + align:start position:0% +to you know you have to have new people + + + align:start position:0% +to you know you have to have new people +operate the maybe one of the most + + align:start position:0% +operate the maybe one of the most + + + align:start position:0% +operate the maybe one of the most +extreme examples of that is an airplane + + align:start position:0% +extreme examples of that is an airplane + + + align:start position:0% +extreme examples of that is an airplane +known as the B-52 have you heard of this + + align:start position:0% +known as the B-52 have you heard of this + + + align:start position:0% +known as the B-52 have you heard of this +this airplane might be the first + + align:start position:0% +this airplane might be the first + + + align:start position:0% +this airplane might be the first +airplane that actually has a 100-year + + align:start position:0% +airplane that actually has a 100-year + + + align:start position:0% +airplane that actually has a 100-year +operational life and there are + + align:start position:0% +operational life and there are + + + align:start position:0% +operational life and there are +apparently maybe you uh Air Force guys + + align:start position:0% +apparently maybe you uh Air Force guys + + + align:start position:0% +apparently maybe you uh Air Force guys +at MIT you can confirm this that there's + + align:start position:0% +at MIT you can confirm this that there's + + + align:start position:0% +at MIT you can confirm this that there's +actually like you know the the + + align:start position:0% +actually like you know the the + + + align:start position:0% +actually like you know the the +grandfather was the first you know + + align:start position:0% +grandfather was the first you know + + + align:start position:0% +grandfather was the first you know +generation and there's like third + + align:start position:0% +generation and there's like third + + + align:start position:0% +generation and there's like third +generation Pilots now flying on the B-52 + + align:start position:0% +generation Pilots now flying on the B-52 + + + align:start position:0% +generation Pilots now flying on the B-52 +that's what I've been told is that have + + align:start position:0% +that's what I've been told is that have + + + align:start position:0% +that's what I've been told is that have +you did you hear this as + + align:start position:0% +you did you hear this as + + + align:start position:0% +you did you hear this as +well yeah that's that's + + align:start position:0% +well yeah that's that's + + + align:start position:0% +well yeah that's that's +correct do you know some of these people + + align:start position:0% +correct do you know some of these people + + + align:start position:0% +correct do you know some of these people +no I've never actually worked on uh that + + align:start position:0% +no I've never actually worked on uh that + + + align:start position:0% +no I've never actually worked on uh that +airframe okay but anyway so that's what + + align:start position:0% +airframe okay but anyway so that's what + + + align:start position:0% +airframe okay but anyway so that's what +I mean by training and certification not + + align:start position:0% +I mean by training and certification not + + + align:start position:0% +I mean by training and certification not +just of the initial operators but you + + align:start position:0% +just of the initial operators but you + + + align:start position:0% +just of the initial operators but you +know over multiple Generations then the + + align:start position:0% +know over multiple Generations then the + + + align:start position:0% +know over multiple Generations then the +third thing here is servicing and + + align:start position:0% +third thing here is servicing and + + + align:start position:0% +third thing here is servicing and +servicing comes in two flavors are + + align:start position:0% +servicing comes in two flavors are + + + align:start position:0% +servicing comes in two flavors are +preventive maintenance you know regular + + align:start position:0% +preventive maintenance you know regular + + + align:start position:0% +preventive maintenance you know regular +maintenance uh and then corrective + + align:start position:0% +maintenance uh and then corrective + + + align:start position:0% +maintenance uh and then corrective +maintenance which we also call repair uh + + align:start position:0% +maintenance which we also call repair uh + + + align:start position:0% +maintenance which we also call repair uh +dealing with small and large failures + + align:start position:0% +dealing with small and large failures + + + align:start position:0% +dealing with small and large failures +recalls anomalies big this is a big deal + + align:start position:0% +recalls anomalies big this is a big deal + + + align:start position:0% +recalls anomalies big this is a big deal +in the automotive industry as we know uh + + align:start position:0% +in the automotive industry as we know uh + + + align:start position:0% +in the automotive industry as we know uh +increasingly protecting the system from + + align:start position:0% +increasingly protecting the system from + + + align:start position:0% +increasingly protecting the system from +either random or targeted attacks cyber + + align:start position:0% +either random or targeted attacks cyber + + + align:start position:0% +either random or targeted attacks cyber +physical right + + align:start position:0% +physical right + + + align:start position:0% +physical right +physical security but also cyber + + align:start position:0% +physical security but also cyber + + + align:start position:0% +physical security but also cyber +security is becoming a huge topic uh + + align:start position:0% +security is becoming a huge topic uh + + + align:start position:0% +security is becoming a huge topic uh +sharing And archiving the data that's + + align:start position:0% +sharing And archiving the data that's + + + align:start position:0% +sharing And archiving the data that's +being produced by the system more and + + align:start position:0% +being produced by the system more and + + + align:start position:0% +being produced by the system more and +more systems produce large amounts of + + align:start position:0% +more systems produce large amounts of + + + align:start position:0% +more systems produce large amounts of +data well what do you do with it how do + + align:start position:0% +data well what do you do with it how do + + + align:start position:0% +data well what do you do with it how do +you store that data um upgrading and + + align:start position:0% +you store that data um upgrading and + + + align:start position:0% +you store that data um upgrading and +retrofitting the system as needed so + + align:start position:0% +retrofitting the system as needed so + + + align:start position:0% +retrofitting the system as needed so +retrofitting means we're physically + + align:start position:0% +retrofitting means we're physically + + + align:start position:0% +retrofitting means we're physically +changing the configuration of the system + + align:start position:0% +changing the configuration of the system + + + align:start position:0% +changing the configuration of the system +right over its life to add new + + align:start position:0% +right over its life to add new + + + align:start position:0% +right over its life to add new +capabilities um and uh upgrading + + align:start position:0% +capabilities um and uh upgrading + + + align:start position:0% +capabilities um and uh upgrading +upgrading can be done sometimes without + + align:start position:0% +upgrading can be done sometimes without + + + align:start position:0% +upgrading can be done sometimes without +having to change the hardware right so + + align:start position:0% +having to change the hardware right so + + + align:start position:0% +having to change the hardware right so +you're doing like a software upgrade or + + align:start position:0% +you're doing like a software upgrade or + + + align:start position:0% +you're doing like a software upgrade or +software update software patching all of + + align:start position:0% +software update software patching all of + + + align:start position:0% +software update software patching all of +this would would go under upgrades + + align:start position:0% +this would would go under upgrades + + + align:start position:0% +this would would go under upgrades +um cross strapping the system with other + + align:start position:0% +um cross strapping the system with other + + + align:start position:0% +um cross strapping the system with other +systems in a Federation of systems so + + align:start position:0% +systems in a Federation of systems so + + + align:start position:0% +systems in a Federation of systems so +what I mean by this is a system May uh + + align:start position:0% +what I mean by this is a system May uh + + + align:start position:0% +what I mean by this is a system May uh +have been designed just to operate on + + align:start position:0% +have been designed just to operate on + + + align:start position:0% +have been designed just to operate on +its own but now you're connecting it + + align:start position:0% +its own but now you're connecting it + + + align:start position:0% +its own but now you're connecting it +with another system this happened in for + + align:start position:0% +with another system this happened in for + + + align:start position:0% +with another system this happened in for +example the electrical grid right the + + align:start position:0% +example the electrical grid right the + + + align:start position:0% +example the electrical grid right the +the early electrical grids were local + + align:start position:0% +the early electrical grids were local + + + align:start position:0% +the early electrical grids were local +Regional power grids and now we've + + align:start position:0% +Regional power grids and now we've + + + align:start position:0% +Regional power grids and now we've +connected them in the US we we have + + align:start position:0% +connected them in the US we we have + + + align:start position:0% +connected them in the US we we have +three major grids the Eastern the + + align:start position:0% +three major grids the Eastern the + + + align:start position:0% +three major grids the Eastern the +Western and then Texas has its own grid + + align:start position:0% +Western and then Texas has its own grid + + + align:start position:0% +Western and then Texas has its own grid +Texas does a lot of its own stuff it's + + align:start position:0% +Texas does a lot of its own stuff it's + + + align:start position:0% +Texas does a lot of its own stuff it's +called aircut and then here in Europe uh + + align:start position:0% +called aircut and then here in Europe uh + + + align:start position:0% +called aircut and then here in Europe uh +you know the European electrical grid is + + align:start position:0% +you know the European electrical grid is + + + align:start position:0% +you know the European electrical grid is +now Continental wide and it used to be + + align:start position:0% +now Continental wide and it used to be + + + align:start position:0% +now Continental wide and it used to be +and of course that that has big big + + align:start position:0% +and of course that that has big big + + + align:start position:0% +and of course that that has big big +implications for operations um reducing + + align:start position:0% +implications for operations um reducing + + + align:start position:0% +implications for operations um reducing +the resource consumption and + + align:start position:0% +the resource consumption and + + + align:start position:0% +the resource consumption and +environmental burden of the system over + + align:start position:0% +environmental burden of the system over + + + align:start position:0% +environmental burden of the system over +time and then finally decommissioning + + align:start position:0% +time and then finally decommissioning + + + align:start position:0% +time and then finally decommissioning +the system when it's time to to do so + + align:start position:0% +the system when it's time to to do so + + + align:start position:0% +the system when it's time to to do so +and you know in many systems this is a + + align:start position:0% +and you know in many systems this is a + + + align:start position:0% +and you know in many systems this is a +big uh challenge is to finding when is + + align:start position:0% +big uh challenge is to finding when is + + + align:start position:0% +big uh challenge is to finding when is +the right time to uh decommission the + + align:start position:0% +the right time to uh decommission the + + + align:start position:0% +the right time to uh decommission the +system and that's often the case when + + align:start position:0% +system and that's often the case when + + + align:start position:0% +system and that's often the case when +you know the operating cost exceeds the + + align:start position:0% +you know the operating cost exceeds the + + + align:start position:0% +you know the operating cost exceeds the +value that the system delivers so this + + align:start position:0% +value that the system delivers so this + + + align:start position:0% +value that the system delivers so this +is a pretty long list here and um a lot + + align:start position:0% +is a pretty long list here and um a lot + + + align:start position:0% +is a pretty long list here and um a lot +of a lot of tasks a lot of decisions to + + align:start position:0% +of a lot of tasks a lot of decisions to + + + align:start position:0% +of a lot of tasks a lot of decisions to +be + + align:start position:0% +be + + + align:start position:0% +be +made um any questions about this list + + align:start position:0% +made um any questions about this list + + + align:start position:0% +made um any questions about this list +it's I don't think it's complete but um + + align:start position:0% +it's I don't think it's complete but um + + + align:start position:0% +it's I don't think it's complete but um +this this is this is a lot of things you + + align:start position:0% +this this is this is a lot of things you + + + align:start position:0% +this this is this is a lot of things you +need to take care of during operations + + align:start position:0% +need to take care of during operations + + + align:start position:0% +need to take care of during operations +here's a a more a more graphical view of + + align:start position:0% +here's a a more a more graphical view of + + + align:start position:0% +here's a a more a more graphical view of +this so this is my sketch of the systems + + align:start position:0% +this so this is my sketch of the systems + + + align:start position:0% +this so this is my sketch of the systems +engineering life cycle so this is part + + align:start position:0% +engineering life cycle so this is part + + + align:start position:0% +engineering life cycle so this is part +one right con conceptual design con + + align:start position:0% +one right con conceptual design con + + + align:start position:0% +one right con conceptual design con +conception design and implementation you + + align:start position:0% +conception design and implementation you + + + align:start position:0% +conception design and implementation you +start the life cycle you do something + + align:start position:0% +start the life cycle you do something + + + align:start position:0% +start the life cycle you do something +like a system requirements review + + align:start position:0% +like a system requirements review + + + align:start position:0% +like a system requirements review +understand the mission the requirements + + align:start position:0% +understand the mission the requirements + + + align:start position:0% +understand the mission the requirements +the constraints you you do conceptual + + align:start position:0% +the constraints you you do conceptual + + + align:start position:0% +the constraints you you do conceptual +design that's where you do creativity + + align:start position:0% +design that's where you do creativity + + + align:start position:0% +design that's where you do creativity +architecting trade studies at the PDR + + align:start position:0% +architecting trade studies at the PDR + + + align:start position:0% +architecting trade studies at the PDR +you choose your so in this case you know + + align:start position:0% +you choose your so in this case you know + + + align:start position:0% +you choose your so in this case you know +we're going to go for this triangle + + align:start position:0% +we're going to go for this triangle + + + align:start position:0% +we're going to go for this triangle +concept and then you design all the + + align:start position:0% +concept and then you design all the + + + align:start position:0% +concept and then you design all the +details within it that's where we do + + align:start position:0% +details within it that's where we do + + + align:start position:0% +details within it that's where we do +modeling simulation + + align:start position:0% +modeling simulation + + + align:start position:0% +modeling simulation +experiments uh mdo uh and we iterate uh + + align:start position:0% +experiments uh mdo uh and we iterate uh + + + align:start position:0% +experiments uh mdo uh and we iterate uh +sometimes you have to iterate this this + + align:start position:0% +sometimes you have to iterate this this + + + align:start position:0% +sometimes you have to iterate this this +dashed iteration means abandoning the + + align:start position:0% +dashed iteration means abandoning the + + + align:start position:0% +dashed iteration means abandoning the +concept you chose and go for a different + + align:start position:0% +concept you chose and go for a different + + + align:start position:0% +concept you chose and go for a different +concept that's usually undesirable at + + align:start position:0% +concept that's usually undesirable at + + + align:start position:0% +concept that's usually undesirable at +the after the CDR we implement the + + align:start position:0% +the after the CDR we implement the + + + align:start position:0% +the after the CDR we implement the +system we turn information to matter and + + align:start position:0% +system we turn information to matter and + + + align:start position:0% +system we turn information to matter and +this all happens in a technological + + align:start position:0% +this all happens in a technological + + + align:start position:0% +this all happens in a technological +economic social context so then the + + align:start position:0% +economic social context so then the + + + align:start position:0% +economic social context so then the +second the second part of it you know + + align:start position:0% +second the second part of it you know + + + align:start position:0% +second the second part of it you know +which in many systems you know if this + + align:start position:0% +which in many systems you know if this + + + align:start position:0% +which in many systems you know if this +if this is 10 years this could be 30 + + align:start position:0% +if this is 10 years this could be 30 + + + align:start position:0% +if this is 10 years this could be 30 +years or more uh is the actual + + align:start position:0% +years or more uh is the actual + + + align:start position:0% +years or more uh is the actual +operational phase so the system has now + + align:start position:0% +operational phase so the system has now + + + align:start position:0% +operational phase so the system has now +been tested validated verified and + + align:start position:0% +been tested validated verified and + + + align:start position:0% +been tested validated verified and +deployed and now uh you know we we + + align:start position:0% +deployed and now uh you know we we + + + align:start position:0% +deployed and now uh you know we we +operate the system things break we need + + align:start position:0% +operate the system things break we need + + + align:start position:0% +operate the system things break we need +to service it and then I have this um + + align:start position:0% +to service it and then I have this um + + + align:start position:0% +to service it and then I have this um +you see there's two versions of the + + align:start position:0% +you see there's two versions of the + + + align:start position:0% +you see there's two versions of the +system one is solid and the other one is + + align:start position:0% +system one is solid and the other one is + + + align:start position:0% +system one is solid and the other one is +kind of faint that's a virtual version + + align:start position:0% +kind of faint that's a virtual version + + + align:start position:0% +kind of faint that's a virtual version +of the system so one of the big Concepts + + align:start position:0% +of the system so one of the big Concepts + + + align:start position:0% +of the system so one of the big Concepts +that's being pushed now in certainly in + + align:start position:0% +that's being pushed now in certainly in + + + align:start position:0% +that's being pushed now in certainly in +the US uh by the dod but also other + + align:start position:0% +the US uh by the dod but also other + + + align:start position:0% +the US uh by the dod but also other +places is the idea of a digital twin + + align:start position:0% +places is the idea of a digital twin + + + align:start position:0% +places is the idea of a digital twin +right the the idea of a digital twin is + + align:start position:0% +right the the idea of a digital twin is + + + align:start position:0% +right the the idea of a digital twin is +that there's the physical system right + + align:start position:0% +that there's the physical system right + + + align:start position:0% +that there's the physical system right +that exists and then there's a digital + + align:start position:0% +that exists and then there's a digital + + + align:start position:0% +that exists and then there's a digital +version a digital twin of that system + + align:start position:0% +version a digital twin of that system + + + align:start position:0% +version a digital twin of that system +somewhere on a on a computer that + + align:start position:0% +somewhere on a on a computer that + + + align:start position:0% +somewhere on a on a computer that +mirrors exactly what the real system is + + align:start position:0% +mirrors exactly what the real system is + + + align:start position:0% +mirrors exactly what the real system is +doing so if something breaks on the + + align:start position:0% +doing so if something breaks on the + + + align:start position:0% +doing so if something breaks on the +physical system well that same component + + align:start position:0% +physical system well that same component + + + align:start position:0% +physical system well that same component +fails in the digital twin and then + + align:start position:0% +fails in the digital twin and then + + + align:start position:0% +fails in the digital twin and then +before you actually do a repair or any + + align:start position:0% +before you actually do a repair or any + + + align:start position:0% +before you actually do a repair or any +actions you execute those actions on the + + align:start position:0% +actions you execute those actions on the + + + align:start position:0% +actions you execute those actions on the +digital twin to see whether the system + + align:start position:0% +digital twin to see whether the system + + + align:start position:0% +digital twin to see whether the system +will operate properly and um and so this + + align:start position:0% +will operate properly and um and so this + + + align:start position:0% +will operate properly and um and so this +is this is kind of the the the latest + + align:start position:0% +is this is kind of the the the latest + + + align:start position:0% +is this is kind of the the the latest +this thinking is that for any system we + + align:start position:0% +this thinking is that for any system we + + + align:start position:0% +this thinking is that for any system we +should have a digital twin uh during + + align:start position:0% +should have a digital twin uh during + + + align:start position:0% +should have a digital twin uh during +operation + + align:start position:0% +operation + + + align:start position:0% +operation +upgrading the system so in this case + + align:start position:0% +upgrading the system so in this case + + + align:start position:0% +upgrading the system so in this case +we're we're adding things to it we're + + align:start position:0% +we're we're adding things to it we're + + + align:start position:0% +we're we're adding things to it we're +connecting it you know and at some point + + align:start position:0% +connecting it you know and at some point + + + align:start position:0% +connecting it you know and at some point +the system does degrade because for + + align:start position:0% +the system does degrade because for + + + align:start position:0% +the system does degrade because for +example you know materials age they get + + align:start position:0% +example you know materials age they get + + + align:start position:0% +example you know materials age they get +brittle uh technology becomes + + align:start position:0% +brittle uh technology becomes + + + align:start position:0% +brittle uh technology becomes +obsolete you know it gets harder and + + align:start position:0% +obsolete you know it gets harder and + + + align:start position:0% +obsolete you know it gets harder and +harder to maintain spare parts are uh + + align:start position:0% +harder to maintain spare parts are uh + + + align:start position:0% +harder to maintain spare parts are uh +the the suppliers of the original spare + + align:start position:0% +the the suppliers of the original spare + + + align:start position:0% +the the suppliers of the original spare +parts went out of business so these + + align:start position:0% +parts went out of business so these + + + align:start position:0% +parts went out of business so these +really old Legacy systems can be very + + align:start position:0% +really old Legacy systems can be very + + + align:start position:0% +really old Legacy systems can be very +expensive to operate and then at some + + align:start position:0% +expensive to operate and then at some + + + align:start position:0% +expensive to operate and then at some +point you liquidate and uh and it's the + + align:start position:0% +point you liquidate and uh and it's the + + + align:start position:0% +point you liquidate and uh and it's the +end of the life cycle so I've already + + align:start position:0% +end of the life cycle so I've already + + + align:start position:0% +end of the life cycle so I've already +told you about one example for this + + align:start position:0% +told you about one example for this + + + align:start position:0% +told you about one example for this +which is uh the space shuttle and uh so + + align:start position:0% +which is uh the space shuttle and uh so + + + align:start position:0% +which is uh the space shuttle and uh so +I'm not going to belabor this again but + + align:start position:0% +I'm not going to belabor this again but + + + align:start position:0% +I'm not going to belabor this again but +I think it's a it's a great opportunity + + align:start position:0% +I think it's a it's a great opportunity + + + align:start position:0% +I think it's a it's a great opportunity +to learn the space shuttle had a 10-year + + align:start position:0% +to learn the space shuttle had a 10-year + + + align:start position:0% +to learn the space shuttle had a 10-year +design life uh roughly from 1971 until + + align:start position:0% +design life uh roughly from 1971 until + + + align:start position:0% +design life uh roughly from 1971 until +81 first flight and then we operated the + + align:start position:0% +81 first flight and then we operated the + + + align:start position:0% +81 first flight and then we operated the +shuttle for 30 years and we had a total + + align:start position:0% +shuttle for 30 years and we had a total + + + align:start position:0% +shuttle for 30 years and we had a total +of 135 launches during that time we + + align:start position:0% +of 135 launches during that time we + + + align:start position:0% +of 135 launches during that time we +spent 1992 billion uh dollars on the + + align:start position:0% +spent 1992 billion uh dollars on the + + + align:start position:0% +spent 1992 billion uh dollars on the +shuttle program and if you average that + + align:start position:0% +shuttle program and if you average that + + + align:start position:0% +shuttle program and if you average that +it's 1.5 billion per flight which is a + + align:start position:0% +it's 1.5 billion per flight which is a + + + align:start position:0% +it's 1.5 billion per flight which is a +lot more than uh than was planned but + + align:start position:0% +lot more than uh than was planned but + + + align:start position:0% +lot more than uh than was planned but +just yesterday here at the epfl we had + + align:start position:0% +just yesterday here at the epfl we had + + + align:start position:0% +just yesterday here at the epfl we had +the uh annual meeting of the um Swiss + + align:start position:0% +the uh annual meeting of the um Swiss + + + align:start position:0% +the uh annual meeting of the um Swiss +Space Center and one of the uh + + align:start position:0% +Space Center and one of the uh + + + align:start position:0% +Space Center and one of the uh +astronauts here Cloe nicolier gave and + + align:start position:0% +astronauts here Cloe nicolier gave and + + + align:start position:0% +astronauts here Cloe nicolier gave and +and his colleague uh professor meron + + align:start position:0% +and his colleague uh professor meron + + + align:start position:0% +and his colleague uh professor meron +gave a great talk about uh the Hubble + + align:start position:0% +gave a great talk about uh the Hubble + + + align:start position:0% +gave a great talk about uh the Hubble +and the servicing of the Hubble and you + + align:start position:0% +and the servicing of the Hubble and you + + + align:start position:0% +and the servicing of the Hubble and you +know the the amazing things we've + + align:start position:0% +know the the amazing things we've + + + align:start position:0% +know the the amazing things we've +learned through it and uh uh you guys at + + align:start position:0% +learned through it and uh uh you guys at + + + align:start position:0% +learned through it and uh uh you guys at +MIT Jeff Hoffman was part of uh at least + + align:start position:0% +MIT Jeff Hoffman was part of uh at least + + + align:start position:0% +MIT Jeff Hoffman was part of uh at least +the first servicing Mission as well so + + align:start position:0% +the first servicing Mission as well so + + + align:start position:0% +the first servicing Mission as well so +there's you know incredible things that + + align:start position:0% +there's you know incredible things that + + + align:start position:0% +there's you know incredible things that +were done by the shuttle and uh and so I + + align:start position:0% +were done by the shuttle and uh and so I + + + align:start position:0% +were done by the shuttle and uh and so I +think we we need to acknowledge that not + + align:start position:0% +think we we need to acknowledge that not + + + align:start position:0% +think we we need to acknowledge that not +just the fact that uh it was very + + align:start position:0% +just the fact that uh it was very + + + align:start position:0% +just the fact that uh it was very +expensive it accomplished great things + + align:start position:0% +expensive it accomplished great things + + + align:start position:0% +expensive it accomplished great things +during its life but you know if we had a + + align:start position:0% +during its life but you know if we had a + + + align:start position:0% +during its life but you know if we had a +chance to do it again would we would we + + align:start position:0% +chance to do it again would we would we + + + align:start position:0% +chance to do it again would we would we +come up with the exact same system would + + align:start position:0% +come up with the exact same system would + + + align:start position:0% +come up with the exact same system would +we make all the same design decisions + + align:start position:0% +we make all the same design decisions + + + align:start position:0% +we make all the same design decisions +you know we lost two of them probably + + align:start position:0% +you know we lost two of them probably + + + align:start position:0% +you know we lost two of them probably +not we would probably do something + + align:start position:0% +not we would probably do something + + + align:start position:0% +not we would probably do something +something different um so here's what we + + align:start position:0% +something different um so here's what we + + + align:start position:0% +something different um so here's what we +wanted and then finally we got a much + + align:start position:0% +wanted and then finally we got a much + + + align:start position:0% +wanted and then finally we got a much +more complex system in the end and + + align:start position:0% +more complex system in the end and + + + align:start position:0% +more complex system in the end and +particularly uh my sense is that a lot + + align:start position:0% +particularly uh my sense is that a lot + + + align:start position:0% +particularly uh my sense is that a lot +of the things that made the shuttle + + align:start position:0% +of the things that made the shuttle + + + align:start position:0% +of the things that made the shuttle +expensive to operate during its life + + align:start position:0% +expensive to operate during its life + + + align:start position:0% +expensive to operate during its life +were things related to U maintainability + + align:start position:0% +were things related to U maintainability + + + align:start position:0% +were things related to U maintainability +right reliability and so forth so the + + align:start position:0% +right reliability and so forth so the + + + align:start position:0% +right reliability and so forth so the +life cycle properties which I want to + + align:start position:0% +life cycle properties which I want to + + + align:start position:0% +life cycle properties which I want to +talk about next so the I I just going to + + align:start position:0% +talk about next so the I I just going to + + + align:start position:0% +talk about next so the I I just going to +repeat the question so you guys can hear + + align:start position:0% +repeat the question so you guys can hear + + + align:start position:0% +repeat the question so you guys can hear +as well so the question was about uh + + align:start position:0% +as well so the question was about uh + + + align:start position:0% +as well so the question was about uh +reusability so the the shuttle was re + + align:start position:0% +reusability so the the shuttle was re + + + align:start position:0% +reusability so the the shuttle was re +the Orbiter was fully reusable uh the + + align:start position:0% +the Orbiter was fully reusable uh the + + + align:start position:0% +the Orbiter was fully reusable uh the +external fuel tank was not reusable + + align:start position:0% +external fuel tank was not reusable + + + align:start position:0% +external fuel tank was not reusable +right and then the solid rocket boosters + + align:start position:0% +right and then the solid rocket boosters + + + align:start position:0% +right and then the solid rocket boosters +were partially reusable because they had + + align:start position:0% +were partially reusable because they had + + + align:start position:0% +were partially reusable because they had +to be stripped down you know and and and + + align:start position:0% +to be stripped down you know and and and + + + align:start position:0% +to be stripped down you know and and and +rebuilt essentially for every launch the + + align:start position:0% +rebuilt essentially for every launch the + + + align:start position:0% +rebuilt essentially for every launch the +idea of you know blue origin and then + + align:start position:0% +idea of you know blue origin and then + + + align:start position:0% +idea of you know blue origin and then +SpaceX stage one you know flying it back + + align:start position:0% +SpaceX stage one you know flying it back + + + align:start position:0% +SpaceX stage one you know flying it back +to the to the launch site is absolutely + + align:start position:0% +to the to the launch site is absolutely + + + align:start position:0% +to the to the launch site is absolutely +the fact that if you can make it + + align:start position:0% +the fact that if you can make it + + + align:start position:0% +the fact that if you can make it +reusable then you should you can + + align:start position:0% +reusable then you should you can + + + align:start position:0% +reusable then you should you can +amortize the capex in that element over + + align:start position:0% +amortize the capex in that element over + + + align:start position:0% +amortize the capex in that element over +multiple flights and it should drop you + + align:start position:0% +multiple flights and it should drop you + + + align:start position:0% +multiple flights and it should drop you +know the cost by you know a factor of + + align:start position:0% +know the cost by you know a factor of + + + align:start position:0% +know the cost by you know a factor of +five or 10 or more now the devils in the + + align:start position:0% +five or 10 or more now the devils in the + + + align:start position:0% +five or 10 or more now the devils in the +details right so if you start and + + align:start position:0% +details right so if you start and + + + align:start position:0% +details right so if you start and +restart an engine multiple times you + + align:start position:0% +restart an engine multiple times you + + + align:start position:0% +restart an engine multiple times you +have a big transient every time so did + + align:start position:0% +have a big transient every time so did + + + align:start position:0% +have a big transient every time so did +was the system in fact designed to + + align:start position:0% +was the system in fact designed to + + + align:start position:0% +was the system in fact designed to +withstand these transients can it handle + + align:start position:0% +withstand these transients can it handle + + + align:start position:0% +withstand these transients can it handle +multiple starts uh what does it do to + + align:start position:0% +multiple starts uh what does it do to + + + align:start position:0% +multiple starts uh what does it do to +the materials and so forth and and so to + + align:start position:0% +the materials and so forth and and so to + + + align:start position:0% +the materials and so forth and and so to +really model this ahead of time and then + + align:start position:0% +really model this ahead of time and then + + + align:start position:0% +really model this ahead of time and then +test it over these Cycles is the key so + + align:start position:0% +test it over these Cycles is the key so + + + align:start position:0% +test it over these Cycles is the key so +in the shuttle the big problems the two + + align:start position:0% +in the shuttle the big problems the two + + + align:start position:0% +in the shuttle the big problems the two +major subsystems in the shuttle in the + + align:start position:0% +major subsystems in the shuttle in the + + + align:start position:0% +major subsystems in the shuttle in the +Orbiter in particular that that made it + + align:start position:0% +Orbiter in particular that that made it + + + align:start position:0% +Orbiter in particular that that made it +expensive uh and the difference between + + align:start position:0% +expensive uh and the difference between + + + align:start position:0% +expensive uh and the difference between +the top picture and the bottom picture + + align:start position:0% +the top picture and the bottom picture + + + align:start position:0% +the top picture and the bottom picture +was a the TPS the thermal protection + + align:start position:0% +was a the TPS the thermal protection + + + align:start position:0% +was a the TPS the thermal protection +system you know every uh every tile has + + align:start position:0% +system you know every uh every tile has + + + align:start position:0% +system you know every uh every tile has +a had a different curvature and geometry + + align:start position:0% +a had a different curvature and geometry + + + align:start position:0% +a had a different curvature and geometry +so really inspecting every tile uh + + align:start position:0% +so really inspecting every tile uh + + + align:start position:0% +so really inspecting every tile uh +replacing tiles making sure that the TPS + + align:start position:0% +replacing tiles making sure that the TPS + + + align:start position:0% +replacing tiles making sure that the TPS +was CU just one weakness in the TPS + + align:start position:0% +was CU just one weakness in the TPS + + + align:start position:0% +was CU just one weakness in the TPS +could you know basically be fatal on + + align:start position:0% +could you know basically be fatal on + + + align:start position:0% +could you know basically be fatal on +re-entry and so TPS was very difficult + + align:start position:0% +re-entry and so TPS was very difficult + + + align:start position:0% +re-entry and so TPS was very difficult +and uh you know as opposed to an + + align:start position:0% +and uh you know as opposed to an + + + align:start position:0% +and uh you know as opposed to an +ablative heat shield that you just + + align:start position:0% +ablative heat shield that you just + + + align:start position:0% +ablative heat shield that you just +sacrific the heat shield uh completely + + align:start position:0% +sacrific the heat shield uh completely + + + align:start position:0% +sacrific the heat shield uh completely +and then the other was the main engine + + align:start position:0% +and then the other was the main engine + + + align:start position:0% +and then the other was the main engine +the shuttle main engine originally the + + align:start position:0% +the shuttle main engine originally the + + + align:start position:0% +the shuttle main engine originally the +idea was to only do very deep + + align:start position:0% +idea was to only do very deep + + + align:start position:0% +idea was to only do very deep +inspections and disassembly disassembly + + align:start position:0% +inspections and disassembly disassembly + + + align:start position:0% +inspections and disassembly disassembly +of the shuttle main engine after the + + align:start position:0% +of the shuttle main engine after the + + + align:start position:0% +of the shuttle main engine after the +first few test flights and then fly + + align:start position:0% +first few test flights and then fly + + + align:start position:0% +first few test flights and then fly +multiple times without having to really + + align:start position:0% +multiple times without having to really + + + align:start position:0% +multiple times without having to really +reinspect or you know disassemble the + + align:start position:0% +reinspect or you know disassemble the + + + align:start position:0% +reinspect or you know disassemble the +engines so they they did the disassembly + + align:start position:0% +engines so they they did the disassembly + + + align:start position:0% +engines so they they did the disassembly +of the engines after the test flights + + align:start position:0% +of the engines after the test flights + + + align:start position:0% +of the engines after the test flights +and then they just kept doing it for + + align:start position:0% +and then they just kept doing it for + + + align:start position:0% +and then they just kept doing it for +every flight where the or original + + align:start position:0% +every flight where the or original + + + align:start position:0% +every flight where the or original +intent was to only do it for the test + + align:start position:0% +intent was to only do it for the test + + + align:start position:0% +intent was to only do it for the test +flights and so the main shuttle main + + align:start position:0% +flights and so the main shuttle main + + + align:start position:0% +flights and so the main shuttle main +engines were the second big cost driver + + align:start position:0% +engines were the second big cost driver + + + align:start position:0% +engines were the second big cost driver +in operations so in in reusability is is + + align:start position:0% +in operations so in in reusability is is + + + align:start position:0% +in operations so in in reusability is is +a great idea but to the degree to which + + align:start position:0% +a great idea but to the degree to which + + + align:start position:0% +a great idea but to the degree to which +reusability actually happens in reality + + align:start position:0% +reusability actually happens in reality + + + align:start position:0% +reusability actually happens in reality +that's you know that's really about + + align:start position:0% +that's you know that's really about + + + align:start position:0% +that's you know that's really about +detailed design decisions you + + align:start position:0% +detailed design decisions you + + + align:start position:0% +detailed design decisions you +make okay so uh let me move on then + + align:start position:0% +make okay so uh let me move on then + + + align:start position:0% +make okay so uh let me move on then +um I want to mention is you know when it + + align:start position:0% +um I want to mention is you know when it + + + align:start position:0% +um I want to mention is you know when it +comes to really understanding um life + + align:start position:0% +comes to really understanding um life + + + align:start position:0% +comes to really understanding um life +cycle proes I do want to point you to + + align:start position:0% +cycle proes I do want to point you to + + + align:start position:0% +cycle proes I do want to point you to +the 15 28 the 15288 standard which is um + + align:start position:0% +the 15 28 the 15288 standard which is um + + + align:start position:0% +the 15 28 the 15288 standard which is um +the iso 15288 standard which has + + align:start position:0% +the iso 15288 standard which has + + + align:start position:0% +the iso 15288 standard which has +a fairly complete list of system life + + align:start position:0% +a fairly complete list of system life + + + align:start position:0% +a fairly complete list of system life +cycle processes so this is essentially + + align:start position:0% +cycle processes so this is essentially + + + align:start position:0% +cycle processes so this is essentially +the system and software engineering + + align:start position:0% +the system and software engineering + + + align:start position:0% +the system and software engineering +system life cycle process standard that + + align:start position:0% +system life cycle process standard that + + + align:start position:0% +system life cycle process standard that +has a whole range of processes that are + + align:start position:0% +has a whole range of processes that are + + + align:start position:0% +has a whole range of processes that are +that are described in quite some detail + + align:start position:0% +that are described in quite some detail + + + align:start position:0% +that are described in quite some detail +and they're not just the technical + + align:start position:0% +and they're not just the technical + + + align:start position:0% +and they're not just the technical +processes shown here on the right side + + align:start position:0% +processes shown here on the right side + + + align:start position:0% +processes shown here on the right side +uh we focused a lot on those technical + + align:start position:0% +uh we focused a lot on those technical + + + align:start position:0% +uh we focused a lot on those technical +processes in this class the stakeholders + + align:start position:0% +processes in this class the stakeholders + + + align:start position:0% +processes in this class the stakeholders +the requirements the architectural + + align:start position:0% +the requirements the architectural + + + align:start position:0% +the requirements the architectural +design which is essentially the + + align:start position:0% +design which is essentially the + + + align:start position:0% +design which is essentially the +conceptual design but there's also the + + align:start position:0% +conceptual design but there's also the + + + align:start position:0% +conceptual design but there's also the +project processes right executing the + + align:start position:0% +project processes right executing the + + + align:start position:0% +project processes right executing the +projects agreement processes so this + + align:start position:0% +projects agreement processes so this + + + align:start position:0% +projects agreement processes so this +would be negotiating uh contracts you + + align:start position:0% +would be negotiating uh contracts you + + + align:start position:0% +would be negotiating uh contracts you +know Supply contracts acquisition + + align:start position:0% +know Supply contracts acquisition + + + align:start position:0% +know Supply contracts acquisition +contracts and then all the + + align:start position:0% +contracts and then all the + + + align:start position:0% +contracts and then all the +organizational things you need to do to + + align:start position:0% +organizational things you need to do to + + + align:start position:0% +organizational things you need to do to +create the right organization to execute + + align:start position:0% +create the right organization to execute + + + align:start position:0% +create the right organization to execute +these projects so what's nice about the + + align:start position:0% +these projects so what's nice about the + + + align:start position:0% +these projects so what's nice about the +uh 15288 standard is that it's it's a + + align:start position:0% +uh 15288 standard is that it's it's a + + + align:start position:0% +uh 15288 standard is that it's it's a +pretty broad + + align:start position:0% +pretty broad + + + align:start position:0% +pretty broad +standard okay so let me talk about the + + align:start position:0% +standard okay so let me talk about the + + + align:start position:0% +standard okay so let me talk about the +Iles of the life cycle properties in + + align:start position:0% +Iles of the life cycle properties in + + + align:start position:0% +Iles of the life cycle properties in +particular uh what they are and how uh + + align:start position:0% +particular uh what they are and how uh + + + align:start position:0% +particular uh what they are and how uh +we can describe them and how especially + + align:start position:0% +we can describe them and how especially + + + align:start position:0% +we can describe them and how especially +how they relate to each other and so the + + align:start position:0% +how they relate to each other and so the + + + align:start position:0% +how they relate to each other and so the +paper there two papers that underly this + + align:start position:0% +paper there two papers that underly this + + + align:start position:0% +paper there two papers that underly this +lecture that you can read to get some + + align:start position:0% +lecture that you can read to get some + + + align:start position:0% +lecture that you can read to get some +more detail and this is one of them so + + align:start position:0% +more detail and this is one of them so + + + align:start position:0% +more detail and this is one of them so +this paper is called investigating the + + align:start position:0% +this paper is called investigating the + + + align:start position:0% +this paper is called investigating the +relationships and semantic sets among + + align:start position:0% +relationships and semantic sets among + + + align:start position:0% +relationships and semantic sets among +life cycle properties and we we + + align:start position:0% +life cycle properties and we we + + + align:start position:0% +life cycle properties and we we +published this about 3 years ago in Del + + align:start position:0% +published this about 3 years ago in Del + + + align:start position:0% +published this about 3 years ago in Del +at the uh seisan conference so um the + + align:start position:0% +at the uh seisan conference so um the + + + align:start position:0% +at the uh seisan conference so um the +the background here is the following is + + align:start position:0% +the background here is the following is + + + align:start position:0% +the background here is the following is +that you know as as you've seen complex + + align:start position:0% +that you know as as you've seen complex + + + align:start position:0% +that you know as as you've seen complex +Engineering Systems live for decades or + + align:start position:0% +Engineering Systems live for decades or + + + align:start position:0% +Engineering Systems live for decades or +some of them even for centuries and the + + align:start position:0% +some of them even for centuries and the + + + align:start position:0% +some of them even for centuries and the +the IL by Ides we mean properties of + + align:start position:0% +the IL by Ides we mean properties of + + + align:start position:0% +the IL by Ides we mean properties of +systems that are that are not the + + align:start position:0% +systems that are that are not the + + + align:start position:0% +systems that are that are not the +primary functional properties in + + align:start position:0% +primary functional properties in + + + align:start position:0% +primary functional properties in +software engineering they're often + + align:start position:0% +software engineering they're often + + + align:start position:0% +software engineering they're often +called nonfunctional properties and the + + align:start position:0% +called nonfunctional properties and the + + + align:start position:0% +called nonfunctional properties and the +the thing that's tricky about the Ides + + align:start position:0% +the thing that's tricky about the Ides + + + align:start position:0% +the thing that's tricky about the Ides +is that you often only can observe them + + align:start position:0% +is that you often only can observe them + + + align:start position:0% +is that you often only can observe them +during operations so you know you can + + align:start position:0% +during operations so you know you can + + + align:start position:0% +during operations so you know you can +test systems in the short term you can + + align:start position:0% +test systems in the short term you can + + + align:start position:0% +test systems in the short term you can +you can see does it work does it fulfill + + align:start position:0% +you can see does it work does it fulfill + + + align:start position:0% +you can see does it work does it fulfill +its function but whether certain ilities + + align:start position:0% +its function but whether certain ilities + + + align:start position:0% +its function but whether certain ilities +are present it often only shows itself + + align:start position:0% +are present it often only shows itself + + + align:start position:0% +are present it often only shows itself +over time um and and so um most of the + + align:start position:0% +over time um and and so um most of the + + + align:start position:0% +over time um and and so um most of the +research that's been done in sort of + + align:start position:0% +research that's been done in sort of + + + align:start position:0% +research that's been done in sort of +quantifying the ilities has been looking + + align:start position:0% +quantifying the ilities has been looking + + + align:start position:0% +quantifying the ilities has been looking +at these properties one at a time so the + + align:start position:0% +at these properties one at a time so the + + + align:start position:0% +at these properties one at a time so the +questions we wanted wanted to go here uh + + align:start position:0% +questions we wanted wanted to go here uh + + + align:start position:0% +questions we wanted wanted to go here uh +wanted to answer is you know is which of + + align:start position:0% +wanted to answer is you know is which of + + + align:start position:0% +wanted to answer is you know is which of +these life cycle properties are more + + align:start position:0% +these life cycle properties are more + + + align:start position:0% +these life cycle properties are more +prevalent than others you know the top + + align:start position:0% +prevalent than others you know the top + + + align:start position:0% +prevalent than others you know the top +20 and then especially what's the + + align:start position:0% +20 and then especially what's the + + + align:start position:0% +20 and then especially what's the +relationship among life cycle properties + + align:start position:0% +relationship among life cycle properties + + + align:start position:0% +relationship among life cycle properties +do they form what we call semantic sets + + align:start position:0% +do they form what we call semantic sets + + + align:start position:0% +do they form what we call semantic sets +and then you know how could you use this + + align:start position:0% +and then you know how could you use this + + + align:start position:0% +and then you know how could you use this +information and so here we're going to + + align:start position:0% +information and so here we're going to + + + align:start position:0% +information and so here we're going to +do this using two different methods the + + align:start position:0% +do this using two different methods the + + + align:start position:0% +do this using two different methods the +first method is what I call prevalence + + align:start position:0% +first method is what I call prevalence + + + align:start position:0% +first method is what I call prevalence +analysis we're going to look in the + + align:start position:0% +analysis we're going to look in the + + + align:start position:0% +analysis we're going to look in the +literature and on the internet how + + align:start position:0% +literature and on the internet how + + + align:start position:0% +literature and on the internet how +frequently these life cycle properties + + align:start position:0% +frequently these life cycle properties + + + align:start position:0% +frequently these life cycle properties +show up are mentioned how much we know + + align:start position:0% +show up are mentioned how much we know + + + align:start position:0% +show up are mentioned how much we know +about them and then the second method is + + align:start position:0% +about them and then the second method is + + + align:start position:0% +about them and then the second method is +a cognitive method where we ask people + + align:start position:0% +a cognitive method where we ask people + + + align:start position:0% +a cognitive method where we ask people +to uh give their understanding of these + + align:start position:0% +to uh give their understanding of these + + + align:start position:0% +to uh give their understanding of these +life cycle properties and put them in + + align:start position:0% +life cycle properties and put them in + + + align:start position:0% +life cycle properties and put them in +into a hierarchy and then we'll compare + + align:start position:0% +into a hierarchy and then we'll compare + + + align:start position:0% +into a hierarchy and then we'll compare +the + + align:start position:0% +the + + + align:start position:0% +the +results so um here are essentially the + + align:start position:0% +results so um here are essentially the + + + align:start position:0% +results so um here are essentially the +results from the prevalence analysis and + + align:start position:0% +results from the prevalence analysis and + + + align:start position:0% +results from the prevalence analysis and +this is ranked according to uh the + + align:start position:0% +this is ranked according to uh the + + + align:start position:0% +this is ranked according to uh the +number of Journal articles uh this is + + align:start position:0% +number of Journal articles uh this is + + + align:start position:0% +number of Journal articles uh this is +scientific Papers written where this + + align:start position:0% +scientific Papers written where this + + + align:start position:0% +scientific Papers written where this +particular keyw like quality or + + align:start position:0% +particular keyw like quality or + + + align:start position:0% +particular keyw like quality or +reliability shows up in the title or in + + align:start position:0% +reliability shows up in the title or in + + + align:start position:0% +reliability shows up in the title or in +the abstract of the paper and you can + + align:start position:0% +the abstract of the paper and you can + + + align:start position:0% +the abstract of the paper and you can +see this is in units of thousands okay + + align:start position:0% +see this is in units of thousands okay + + + align:start position:0% +see this is in units of thousands okay +so quality is number one right quality + + align:start position:0% +so quality is number one right quality + + + align:start position:0% +so quality is number one right quality +is number one the most most scientific + + align:start position:0% +is number one the most most scientific + + + align:start position:0% +is number one the most most scientific +Papers written about quality and you can + + align:start position:0% +Papers written about quality and you can + + + align:start position:0% +Papers written about quality and you can +see it's almost a million Journal + + align:start position:0% +see it's almost a million Journal + + + align:start position:0% +see it's almost a million Journal +articles this is I'll show this to you + + align:start position:0% +articles this is I'll show this to you + + + align:start position:0% +articles this is I'll show this to you +over time but since 1884 is the first + + align:start position:0% +over time but since 1884 is the first + + + align:start position:0% +over time but since 1884 is the first +year okay and the databases that were + + align:start position:0% +year okay and the databases that were + + + align:start position:0% +year okay and the databases that were +used for this are called it's compendex + + align:start position:0% +used for this are called it's compendex + + + align:start position:0% +used for this are called it's compendex +and inspec uh these are actually + + align:start position:0% +and inspec uh these are actually + + + align:start position:0% +and inspec uh these are actually +combined if you go to a website called + + align:start position:0% +combined if you go to a website called + + + align:start position:0% +combined if you go to a website called +engineering Village . this is you know + + align:start position:0% +engineering Village . this is you know + + + align:start position:0% +engineering Village . this is you know +sort of a master database for scientific + + align:start position:0% +sort of a master database for scientific + + + align:start position:0% +sort of a master database for scientific +papers in engineering U that that was + + align:start position:0% +papers in engineering U that that was + + + align:start position:0% +papers in engineering U that that was +the basis for this uh number two + + align:start position:0% +the basis for this uh number two + + + align:start position:0% +the basis for this uh number two +reliability number three safety then + + align:start position:0% +reliability number three safety then + + + align:start position:0% +reliability number three safety then +flexibility robustness and so forth and + + align:start position:0% +flexibility robustness and so forth and + + + align:start position:0% +flexibility robustness and so forth and +the other bar the gray bar is if you + + align:start position:0% +the other bar the gray bar is if you + + + align:start position:0% +the other bar the gray bar is if you +Google essentially for uh this + + align:start position:0% +Google essentially for uh this + + + align:start position:0% +Google essentially for uh this +particular keyword and you know keep in + + align:start position:0% +particular keyword and you know keep in + + + align:start position:0% +particular keyword and you know keep in +mind this was done about 5 years ago + + align:start position:0% +mind this was done about 5 years ago + + + align:start position:0% +mind this was done about 5 years ago +this is the number the millions of hits + + align:start position:0% +this is the number the millions of hits + + + align:start position:0% +this is the number the millions of hits +that you will get and um so you know + + align:start position:0% +that you will get and um so you know + + + align:start position:0% +that you will get and um so you know +there's a factor of a thousand + + align:start position:0% +there's a factor of a thousand + + + align:start position:0% +there's a factor of a thousand +difference here between Journal articles + + align:start position:0% +difference here between Journal articles + + + align:start position:0% +difference here between Journal articles +and hits on the internet but still you + + align:start position:0% +and hits on the internet but still you + + + align:start position:0% +and hits on the internet but still you +can sort of compare uh the two and so in + + align:start position:0% +can sort of compare uh the two and so in + + + align:start position:0% +can sort of compare uh the two and so in +some sense the black bar is you know the + + align:start position:0% +some sense the black bar is you know the + + + align:start position:0% +some sense the black bar is you know the +the the totality of scientific knowledge + + align:start position:0% +the the totality of scientific knowledge + + + align:start position:0% +the the totality of scientific knowledge +about this life cycle property and then + + align:start position:0% +about this life cycle property and then + + + align:start position:0% +about this life cycle property and then +the gray bar would be you know the U + + align:start position:0% +the gray bar would be you know the U + + + align:start position:0% +the gray bar would be you know the U +amount of information or uses usage of + + align:start position:0% +amount of information or uses usage of + + + align:start position:0% +amount of information or uses usage of +that knowledge at least as far as it's + + align:start position:0% +that knowledge at least as far as it's + + + align:start position:0% +that knowledge at least as far as it's +represented on the internet and what's + + align:start position:0% +represented on the internet and what's + + + align:start position:0% +represented on the internet and what's +interesting is you know in some cases + + align:start position:0% +interesting is you know in some cases + + + align:start position:0% +interesting is you know in some cases +the the the black bar is smaller than uh + + align:start position:0% +the the the black bar is smaller than uh + + + align:start position:0% +the the the black bar is smaller than uh +the gray bar which means that common + + align:start position:0% +the gray bar which means that common + + + align:start position:0% +the gray bar which means that common +usage is leading so sustainability would + + align:start position:0% +usage is leading so sustainability would + + + align:start position:0% +usage is leading so sustainability would +be an example everybody talks about + + align:start position:0% +be an example everybody talks about + + + align:start position:0% +be an example everybody talks about +sustainability you know companies have + + align:start position:0% +sustainability you know companies have + + + align:start position:0% +sustainability you know companies have +you know they say our system is + + align:start position:0% +you know they say our system is + + + align:start position:0% +you know they say our system is +sustainable because you know it uses + + align:start position:0% +sustainable because you know it uses + + + align:start position:0% +sustainable because you know it uses +less resources it produces less + + align:start position:0% +less resources it produces less + + + align:start position:0% +less resources it produces less +emissions but the actual amount of uh + + align:start position:0% +emissions but the actual amount of uh + + + align:start position:0% +emissions but the actual amount of uh +scientific knowledge the actual amount + + align:start position:0% +scientific knowledge the actual amount + + + align:start position:0% +scientific knowledge the actual amount +of research as to what really is + + align:start position:0% +of research as to what really is + + + align:start position:0% +of research as to what really is +sustainability and how do you design for + + align:start position:0% +sustainability and how do you design for + + + align:start position:0% +sustainability and how do you design for +it is actually smaller than the usage + + align:start position:0% +it is actually smaller than the usage + + + align:start position:0% +it is actually smaller than the usage +and then there's areas where it's the + + align:start position:0% +and then there's areas where it's the + + + align:start position:0% +and then there's areas where it's the +opposite like for example modularity + + align:start position:0% +opposite like for example modularity + + + align:start position:0% +opposite like for example modularity +right you see that in modularity um so + + align:start position:0% +right you see that in modularity um so + + + align:start position:0% +right you see that in modularity um so +in a relative sense academic interest is + + align:start position:0% +in a relative sense academic interest is + + + align:start position:0% +in a relative sense academic interest is +leading there's quite a literature on + + align:start position:0% +leading there's quite a literature on + + + align:start position:0% +leading there's quite a literature on +modularity in mathematics you know + + align:start position:0% +modularity in mathematics you know + + + align:start position:0% +modularity in mathematics you know +modularity in software modularity and + + align:start position:0% +modularity in software modularity and + + + align:start position:0% +modularity in software modularity and +design but most people you know + + align:start position:0% +design but most people you know + + + align:start position:0% +design but most people you know +modularity per se is not so interesting + + align:start position:0% +modularity per se is not so interesting + + + align:start position:0% +modularity per se is not so interesting +and so exciting to you know the general + + align:start position:0% +and so exciting to you know the general + + + align:start position:0% +and so exciting to you know the general +public so keep in mind that for some + + align:start position:0% +public so keep in mind that for some + + + align:start position:0% +public so keep in mind that for some +ilities uh there's an imbalance + + align:start position:0% +ilities uh there's an imbalance + + + align:start position:0% +ilities uh there's an imbalance +essentially between our our + + align:start position:0% +essentially between our our + + + align:start position:0% +essentially between our our +understanding of the scientific + + align:start position:0% +understanding of the scientific + + + align:start position:0% +understanding of the scientific +knowledge our understanding to be design + + align:start position:0% +knowledge our understanding to be design + + + align:start position:0% +knowledge our understanding to be design +how to design for it and you know how + + align:start position:0% +how to design for it and you know how + + + align:start position:0% +how to design for it and you know how +frequently at least that keyword is + + align:start position:0% +frequently at least that keyword is + + + align:start position:0% +frequently at least that keyword is +used um now here this is a little bit + + align:start position:0% +used um now here this is a little bit + + + align:start position:0% +used um now here this is a little bit +more uh this is a little bit harder to + + align:start position:0% +more uh this is a little bit harder to + + + align:start position:0% +more uh this is a little bit harder to +see this is essentially looking at these + + align:start position:0% +see this is essentially looking at these + + + align:start position:0% +see this is essentially looking at these +life cycle properties over over time so + + align:start position:0% +life cycle properties over over time so + + + align:start position:0% +life cycle properties over over time so +what this graph shows you is starting + + align:start position:0% +what this graph shows you is starting + + + align:start position:0% +what this graph shows you is starting +here in + + align:start position:0% +here in + + + align:start position:0% +here in + + align:start position:0% + + + align:start position:0% +cumulatively uh the number of Journal + + align:start position:0% +cumulatively uh the number of Journal + + + align:start position:0% +cumulatively uh the number of Journal +articles published about each life cycle + + align:start position:0% +articles published about each life cycle + + + align:start position:0% +articles published about each life cycle +property and uh roughly the way you can + + align:start position:0% +property and uh roughly the way you can + + + align:start position:0% +property and uh roughly the way you can +think about this is that there's some + + align:start position:0% +think about this is that there's some + + + align:start position:0% +think about this is that there's some +life cycle property the top four five + + align:start position:0% +life cycle property the top four five + + + align:start position:0% +life cycle property the top four five +that we've been actually working on for + + align:start position:0% +that we've been actually working on for + + + align:start position:0% +that we've been actually working on for +a long time even safety you know there's + + align:start position:0% +a long time even safety you know there's + + + align:start position:0% +a long time even safety you know there's +some interesting articles in the 1890s + + align:start position:0% +some interesting articles in the 1890s + + + align:start position:0% +some interesting articles in the 1890s +about safety for example in mines you + + align:start position:0% +about safety for example in mines you + + + align:start position:0% +about safety for example in mines you +know coal mines there's an article about + + align:start position:0% +know coal mines there's an article about + + + align:start position:0% +know coal mines there's an article about +how does the impact of lighting better + + align:start position:0% +how does the impact of lighting better + + + align:start position:0% +how does the impact of lighting better +Lighting on safety and productivity in + + align:start position:0% +Lighting on safety and productivity in + + + align:start position:0% +Lighting on safety and productivity in +mines 1890 okay and so they showed that + + align:start position:0% +mines 1890 okay and so they showed that + + + align:start position:0% +mines 1890 okay and so they showed that +just providing better lighting actually + + align:start position:0% +just providing better lighting actually + + + align:start position:0% +just providing better lighting actually +has a dual benefit pure accidents pure + + align:start position:0% +has a dual benefit pure accidents pure + + + align:start position:0% +has a dual benefit pure accidents pure +fatalities and better production output + + align:start position:0% +fatalities and better production output + + + align:start position:0% +fatalities and better production output +and so you know that that's and this was + + align:start position:0% +and so you know that that's and this was + + + align:start position:0% +and so you know that that's and this was +a scientific study that was done by you + + align:start position:0% +a scientific study that was done by you + + + align:start position:0% +a scientific study that was done by you +know comparing data in different minds + + align:start position:0% +know comparing data in different minds + + + align:start position:0% +know comparing data in different minds +and and actually performing some + + align:start position:0% +and and actually performing some + + + align:start position:0% +and and actually performing some +experiments um then you have a group of + + align:start position:0% +experiments um then you have a group of + + + align:start position:0% +experiments um then you have a group of +life cycle properties that we only + + align:start position:0% +life cycle properties that we only + + + align:start position:0% +life cycle properties that we only +started really thinking about and + + align:start position:0% +started really thinking about and + + + align:start position:0% +started really thinking about and +Publishing about I would say around + + align:start position:0% +Publishing about I would say around + + + align:start position:0% +Publishing about I would say around +World War II such as usability uh + + align:start position:0% +World War II such as usability uh + + + align:start position:0% +World War II such as usability uh +maintainability and my interpretation of + + align:start position:0% +maintainability and my interpretation of + + + align:start position:0% +maintainability and my interpretation of +this is that especially during World War + + align:start position:0% +this is that especially during World War + + + align:start position:0% +this is that especially during World War +II a big difference made Logistics you + + align:start position:0% +II a big difference made Logistics you + + + align:start position:0% +II a big difference made Logistics you +know how how easy was it was it to use + + align:start position:0% +know how how easy was it was it to use + + + align:start position:0% +know how how easy was it was it to use +uh different weapons uh how easy was it + + align:start position:0% +uh different weapons uh how easy was it + + + align:start position:0% +uh different weapons uh how easy was it +to maintain + + align:start position:0% +to maintain + + + align:start position:0% +to maintain +equipment uh it became a huge + + align:start position:0% +equipment uh it became a huge + + + align:start position:0% +equipment uh it became a huge +determining factor in the outcome of the + + align:start position:0% +determining factor in the outcome of the + + + align:start position:0% +determining factor in the outcome of the +war you know for example in North Africa + + align:start position:0% +war you know for example in North Africa + + + align:start position:0% +war you know for example in North Africa +and the North African theater uh you + + align:start position:0% +and the North African theater uh you + + + align:start position:0% +and the North African theater uh you +know tanks uh trucks uh being exposed to + + align:start position:0% +know tanks uh trucks uh being exposed to + + + align:start position:0% +know tanks uh trucks uh being exposed to +you know the sand and and so forth so + + align:start position:0% +you know the sand and and so forth so + + + align:start position:0% +you know the sand and and so forth so +people really started thinking about the + + align:start position:0% +people really started thinking about the + + + align:start position:0% +people really started thinking about the +military started thinking heavily About + + align:start position:0% +military started thinking heavily About + + + align:start position:0% +military started thinking heavily About +You Know M the importance of + + align:start position:0% +You Know M the importance of + + + align:start position:0% +You Know M the importance of +maintainability in the design of these + + align:start position:0% +maintainability in the design of these + + + align:start position:0% +maintainability in the design of these +systems and after the war then a lot of + + align:start position:0% +systems and after the war then a lot of + + + align:start position:0% +systems and after the war then a lot of +these Concepts like usability and + + align:start position:0% +these Concepts like usability and + + + align:start position:0% +these Concepts like usability and +maintain ility started spreading into + + align:start position:0% +maintain ility started spreading into + + + align:start position:0% +maintain ility started spreading into +General civilian life and products and + + align:start position:0% +General civilian life and products and + + + align:start position:0% +General civilian life and products and +so forth and then the third uh the third + + align:start position:0% +so forth and then the third uh the third + + + align:start position:0% +so forth and then the third uh the third +uh period or the third type of illes are + + align:start position:0% +uh period or the third type of illes are + + + align:start position:0% +uh period or the third type of illes are +the the newer ones that we've done + + align:start position:0% +the the newer ones that we've done + + + align:start position:0% +the the newer ones that we've done +research on just since the 70s in the + + align:start position:0% +research on just since the 70s in the + + + align:start position:0% +research on just since the 70s in the +last 30 years so here in this category I + + align:start position:0% +last 30 years so here in this category I + + + align:start position:0% +last 30 years so here in this category I +would put things like + + align:start position:0% +would put things like + + + align:start position:0% +would put things like +sustainability uh recyclability + + align:start position:0% +sustainability uh recyclability + + + align:start position:0% +sustainability uh recyclability +evolvability even interoperability which + + align:start position:0% +evolvability even interoperability which + + + align:start position:0% +evolvability even interoperability which +means the ability of systems to connect + + align:start position:0% +means the ability of systems to connect + + + align:start position:0% +means the ability of systems to connect +together and work across system + + align:start position:0% +together and work across system + + + align:start position:0% +together and work across system +boundaries those are pretty recent uh + + align:start position:0% +boundaries those are pretty recent uh + + + align:start position:0% +boundaries those are pretty recent uh +life cycle properties and we're still + + align:start position:0% +life cycle properties and we're still + + + align:start position:0% +life cycle properties and we're still +actively researching + + align:start position:0% +actively researching + + + align:start position:0% +actively researching +them so another way to show this is by + + align:start position:0% +them so another way to show this is by + + + align:start position:0% +them so another way to show this is by +essentially making a network of these + + align:start position:0% +essentially making a network of these + + + align:start position:0% +essentially making a network of these +life cycle properties and so the way + + align:start position:0% +life cycle properties and so the way + + + align:start position:0% +life cycle properties and so the way +this is still all using this prevalence + + align:start position:0% +this is still all using this prevalence + + + align:start position:0% +this is still all using this prevalence +data essentially what you see here is a + + align:start position:0% +data essentially what you see here is a + + + align:start position:0% +data essentially what you see here is a +network diagram that has these life + + align:start position:0% +network diagram that has these life + + + align:start position:0% +network diagram that has these life +cycle properties in a network + + align:start position:0% +cycle properties in a network + + + align:start position:0% +cycle properties in a network +relationship let me just explain um the + + align:start position:0% +relationship let me just explain um the + + + align:start position:0% +relationship let me just explain um the +so the size of the nodes relates to uh + + align:start position:0% +so the size of the nodes relates to uh + + + align:start position:0% +so the size of the nodes relates to uh +how many you know how much knowledge we + + align:start position:0% +how many you know how much knowledge we + + + align:start position:0% +how many you know how much knowledge we +have essentially the the height of the + + align:start position:0% +have essentially the the height of the + + + align:start position:0% +have essentially the the height of the +bars that we saw earlier and then the + + align:start position:0% +bars that we saw earlier and then the + + + align:start position:0% +bars that we saw earlier and then the +strength the thickness of the line + + align:start position:0% +strength the thickness of the line + + + align:start position:0% +strength the thickness of the line +relates to the strength of Rel how + + align:start position:0% +relates to the strength of Rel how + + + align:start position:0% +relates to the strength of Rel how +closely are these two ilities related + + align:start position:0% +closely are these two ilities related + + + align:start position:0% +closely are these two ilities related +and the way this is calculated is using + + align:start position:0% +and the way this is calculated is using + + + align:start position:0% +and the way this is calculated is using +a so-called Tut tupal correlation so you + + align:start position:0% +a so-called Tut tupal correlation so you + + + align:start position:0% +a so-called Tut tupal correlation so you +take essentially articles that have you + + align:start position:0% +take essentially articles that have you + + + align:start position:0% +take essentially articles that have you +look at articles that have for example + + align:start position:0% +look at articles that have for example + + + align:start position:0% +look at articles that have for example +reliability and maintainability in the + + align:start position:0% +reliability and maintainability in the + + + align:start position:0% +reliability and maintainability in the +same article right and then you divide + + align:start position:0% +same article right and then you divide + + + align:start position:0% +same article right and then you divide +that by the total number of articles on + + align:start position:0% +that by the total number of articles on + + + align:start position:0% +that by the total number of articles on +reliability and or maintainability and + + align:start position:0% +reliability and or maintainability and + + + align:start position:0% +reliability and or maintainability and +that's a ratio between zero and one and + + align:start position:0% +that's a ratio between zero and one and + + + align:start position:0% +that's a ratio between zero and one and +then this graph was produced with a + + align:start position:0% +then this graph was produced with a + + + align:start position:0% +then this graph was produced with a +cutof strength of 0.1 right so if + + align:start position:0% +cutof strength of 0.1 right so if + + + align:start position:0% +cutof strength of 0.1 right so if +there's more than 10% of of Articles + + align:start position:0% +there's more than 10% of of Articles + + + align:start position:0% +there's more than 10% of of Articles +list these two properties together then + + align:start position:0% +list these two properties together then + + + align:start position:0% +list these two properties together then +there will be a line here and the + + align:start position:0% +there will be a line here and the + + + align:start position:0% +there will be a line here and the +stronger the line the thicker the line + + align:start position:0% +stronger the line the thicker the line + + + align:start position:0% +stronger the line the thicker the line +is the more closely the more often these + + align:start position:0% +is the more closely the more often these + + + align:start position:0% +is the more closely the more often these +concepts are co- mentioned in the same + + align:start position:0% +concepts are co- mentioned in the same + + + align:start position:0% +concepts are co- mentioned in the same +in the same article or the same piece of + + align:start position:0% +in the same article or the same piece of + + + align:start position:0% +in the same article or the same piece of +work so it reflects the strength of + + align:start position:0% +work so it reflects the strength of + + + align:start position:0% +work so it reflects the strength of +relationship now what's interesting is + + align:start position:0% +relationship now what's interesting is + + + align:start position:0% +relationship now what's interesting is +you know when you first look at this you + + align:start position:0% +you know when you first look at this you + + + align:start position:0% +you know when you first look at this you +you know you don't see much but after + + align:start position:0% +you know you don't see much but after + + + align:start position:0% +you know you don't see much but after +you look at this for a while you start + + align:start position:0% +you look at this for a while you start + + + align:start position:0% +you look at this for a while you start +to realize a few things first of all in + + align:start position:0% +to realize a few things first of all in + + + align:start position:0% +to realize a few things first of all in +the center of the graph we have the + + align:start position:0% +the center of the graph we have the + + + align:start position:0% +the center of the graph we have the +classic ilities of engineering quality + + align:start position:0% +classic ilities of engineering quality + + + align:start position:0% +classic ilities of engineering quality +safety reliability and I would argue + + align:start position:0% +safety reliability and I would argue + + + align:start position:0% +safety reliability and I would argue +flexibility as well those are the top + + align:start position:0% +flexibility as well those are the top + + + align:start position:0% +flexibility as well those are the top +four that we saw before and then around + + align:start position:0% +four that we saw before and then around + + + align:start position:0% +four that we saw before and then around +the periphery of the graph we have newer + + align:start position:0% +the periphery of the graph we have newer + + + align:start position:0% +the periphery of the graph we have newer +life cycle properties that are more + + align:start position:0% +life cycle properties that are more + + + align:start position:0% +life cycle properties that are more +recent we haven't really uh thought + + align:start position:0% +recent we haven't really uh thought + + + align:start position:0% +recent we haven't really uh thought +about them too much we don't fully know + + align:start position:0% +about them too much we don't fully know + + + align:start position:0% +about them too much we don't fully know +how to design for them yet and if you + + align:start position:0% +how to design for them yet and if you + + + align:start position:0% +how to design for them yet and if you +look at them in groups I will argue that + + align:start position:0% +look at them in groups I will argue that + + + align:start position:0% +look at them in groups I will argue that +there are three major groups here so the + + align:start position:0% +there are three major groups here so the + + + align:start position:0% +there are three major groups here so the +first group in the upper left is things + + align:start position:0% +first group in the upper left is things + + + align:start position:0% +first group in the upper left is things +like maintainability durability + + align:start position:0% +like maintainability durability + + + align:start position:0% +like maintainability durability +reliability quality and so forth so this + + align:start position:0% +reliability quality and so forth so this + + + align:start position:0% +reliability quality and so forth so this +is all about is the system made well + + align:start position:0% +is all about is the system made well + + + align:start position:0% +is all about is the system made well +with high quality particularly early in + + align:start position:0% +with high quality particularly early in + + + align:start position:0% +with high quality particularly early in +its life right then we have a a group + + align:start position:0% +its life right then we have a a group + + + align:start position:0% +its life right then we have a a group +here on the right and this is about is + + align:start position:0% +here on the right and this is about is + + + align:start position:0% +here on the right and this is about is +the system easy to change is it easy to + + align:start position:0% +the system easy to change is it easy to + + + align:start position:0% +the system easy to change is it easy to +change the system configuration + + align:start position:0% +change the system configuration + + + align:start position:0% +change the system configuration +flexibility + + align:start position:0% +flexibility + + + align:start position:0% +flexibility +extensibility uh modularity and + + align:start position:0% +extensibility uh modularity and + + + align:start position:0% +extensibility uh modularity and +scalability uh + + align:start position:0% +scalability uh + + + align:start position:0% +scalability uh +interoperability those are all different + + align:start position:0% +interoperability those are all different + + + align:start position:0% +interoperability those are all different +subf flavers if you want of being able + + align:start position:0% +subf flavers if you want of being able + + + align:start position:0% +subf flavers if you want of being able +to modify the system over its life and + + align:start position:0% +to modify the system over its life and + + + align:start position:0% +to modify the system over its life and +so that's group abilities that that goes + + align:start position:0% +so that's group abilities that that goes + + + align:start position:0% +so that's group abilities that that goes +together and then the third one is you + + align:start position:0% +together and then the third one is you + + + align:start position:0% +together and then the third one is you +know resilience robustness quality um + + align:start position:0% +know resilience robustness quality um + + + align:start position:0% +know resilience robustness quality um +safety um and so this is really related + + align:start position:0% +safety um and so this is really related + + + align:start position:0% +safety um and so this is really related +to Performance of the system under + + align:start position:0% +to Performance of the system under + + + align:start position:0% +to Performance of the system under +different types of uncertainty you know + + align:start position:0% +different types of uncertainty you know + + + align:start position:0% +different types of uncertainty you know +either uh environmental variability or + + align:start position:0% +either uh environmental variability or + + + align:start position:0% +either uh environmental variability or +failures in the system and the ability + + align:start position:0% +failures in the system and the ability + + + align:start position:0% +failures in the system and the ability +of the system to withstand or at least + + align:start position:0% +of the system to withstand or at least + + + align:start position:0% +of the system to withstand or at least +perform you know have good residual + + align:start position:0% +perform you know have good residual + + + align:start position:0% +perform you know have good residual +performance even in the face of failures + + align:start position:0% +performance even in the face of failures + + + align:start position:0% +performance even in the face of failures +so that's I think an important way to + + align:start position:0% +so that's I think an important way to + + + align:start position:0% +so that's I think an important way to +think about it and when you're writing + + align:start position:0% +think about it and when you're writing + + + align:start position:0% +think about it and when you're writing +requirements for systems like the system + + align:start position:0% +requirements for systems like the system + + + align:start position:0% +requirements for systems like the system +should be resilient then this helps you + + align:start position:0% +should be resilient then this helps you + + + align:start position:0% +should be resilient then this helps you +understand well what are the other + + align:start position:0% +understand well what are the other + + + align:start position:0% +understand well what are the other +properties that are linked to it and + + align:start position:0% +properties that are linked to it and + + + align:start position:0% +properties that are linked to it and +that maybe support that okay any any + + align:start position:0% +that maybe support that okay any any + + + align:start position:0% +that maybe support that okay any any +questions uh here or at MIT about uh + + align:start position:0% +questions uh here or at MIT about uh + + + align:start position:0% +questions uh here or at MIT about uh +this is sort of method one is get data + + align:start position:0% +this is sort of method one is get data + + + align:start position:0% +this is sort of method one is get data +about these life cycle properties and + + align:start position:0% +about these life cycle properties and + + + align:start position:0% +about these life cycle properties and +put them in relation to each other any + + align:start position:0% +put them in relation to each other any + + + align:start position:0% +put them in relation to each other any +any questions + + align:start position:0% + + + + align:start position:0% + +Yanna are there any questions there yeah + + align:start position:0% +Yanna are there any questions there yeah + + + align:start position:0% +Yanna are there any questions there yeah +I have a question so is this chart that + + align:start position:0% +I have a question so is this chart that + + + align:start position:0% +I have a question so is this chart that +you have up now actually used in the + + align:start position:0% +you have up now actually used in the + + + align:start position:0% +you have up now actually used in the +initial design and like conception + + align:start position:0% +initial design and like conception + + + align:start position:0% +initial design and like conception +conops to like try to tease out the + + align:start position:0% +conops to like try to tease out the + + + align:start position:0% +conops to like try to tease out the +interdependencies or is it too abstract + + align:start position:0% +interdependencies or is it too abstract + + + align:start position:0% +interdependencies or is it too abstract +and just more of a educational + + align:start position:0% +and just more of a educational + + + align:start position:0% +and just more of a educational +tool it's really at this point you know + + align:start position:0% +tool it's really at this point you know + + + align:start position:0% +tool it's really at this point you know +this is fairly recent this was just done + + align:start position:0% +this is fairly recent this was just done + + + align:start position:0% +this is fairly recent this was just done +in the last few years so this I don't + + align:start position:0% +in the last few years so this I don't + + + align:start position:0% +in the last few years so this I don't +think this has fully penetrated system + + align:start position:0% +think this has fully penetrated system + + + align:start position:0% +think this has fully penetrated system +engineering practice yet but the point + + align:start position:0% +engineering practice yet but the point + + + align:start position:0% +engineering practice yet but the point +the point that I I want to make here is + + align:start position:0% +the point that I I want to make here is + + + align:start position:0% +the point that I I want to make here is +that there's a huge there's a huge gap + + align:start position:0% +that there's a huge there's a huge gap + + + align:start position:0% +that there's a huge there's a huge gap +right now between when people in the you + + align:start position:0% +right now between when people in the you + + + align:start position:0% +right now between when people in the you +know in briefings you know either at the + + align:start position:0% +know in briefings you know either at the + + + align:start position:0% +know in briefings you know either at the +the Pentagon or you know at a corporate + + align:start position:0% +the Pentagon or you know at a corporate + + + align:start position:0% +the Pentagon or you know at a corporate +headquarters say you know we want a + + align:start position:0% +headquarters say you know we want a + + + align:start position:0% +headquarters say you know we want a +sustainable product or we want a you + + align:start position:0% +sustainable product or we want a you + + + align:start position:0% +sustainable product or we want a you +know we're a software company we're do + + align:start position:0% +know we're a software company we're do + + + align:start position:0% +know we're a software company we're do +we do Optical networking and we want we + + align:start position:0% +we do Optical networking and we want we + + + align:start position:0% +we do Optical networking and we want we +want to have the most resilient design + + align:start position:0% +want to have the most resilient design + + + align:start position:0% +want to have the most resilient design +of the IND history you know they'll put + + align:start position:0% +of the IND history you know they'll put + + + align:start position:0% +of the IND history you know they'll put +that as a goal for the project the + + align:start position:0% +that as a goal for the project the + + + align:start position:0% +that as a goal for the project the +question then is well okay that's fine + + align:start position:0% +question then is well okay that's fine + + + align:start position:0% +question then is well okay that's fine +but what does that really mean what does + + align:start position:0% +but what does that really mean what does + + + align:start position:0% +but what does that really mean what does +it really mean resilient you have to + + align:start position:0% +it really mean resilient you have to + + + align:start position:0% +it really mean resilient you have to +operationalize that definition such that + + align:start position:0% +operationalize that definition such that + + + align:start position:0% +operationalize that definition such that +you can derive from it lower level + + align:start position:0% +you can derive from it lower level + + + align:start position:0% +you can derive from it lower level +requirements that you can actually go + + align:start position:0% +requirements that you can actually go + + + align:start position:0% +requirements that you can actually go +and designed to that you can test for so + + align:start position:0% +and designed to that you can test for so + + + align:start position:0% +and designed to that you can test for so +um what what what this helps you to do + + align:start position:0% +um what what what this helps you to do + + + align:start position:0% +um what what what this helps you to do +is understand what are what are maybe + + align:start position:0% +is understand what are what are maybe + + + align:start position:0% +is understand what are what are maybe +supporting that what are supporting um + + align:start position:0% +supporting that what are supporting um + + + align:start position:0% +supporting that what are supporting um +elements that will that will will be + + align:start position:0% +elements that will that will will be + + + align:start position:0% +elements that will that will will be +related to resilience you know what are + + align:start position:0% +related to resilience you know what are + + + align:start position:0% +related to resilience you know what are +what are what are supporting Concepts + + align:start position:0% +what are what are supporting Concepts + + + align:start position:0% +what are what are supporting Concepts +supporting life cycle properties that + + align:start position:0% +supporting life cycle properties that + + + align:start position:0% +supporting life cycle properties that +that this property that you're looking + + align:start position:0% +that this property that you're looking + + + align:start position:0% +that this property that you're looking +for uh is linked to right so it's it's + + align:start position:0% +for uh is linked to right so it's it's + + + align:start position:0% +for uh is linked to right so it's it's +an evolution you know we we know how to + + align:start position:0% +an evolution you know we we know how to + + + align:start position:0% +an evolution you know we we know how to +design now for you know speed and Energy + + align:start position:0% +design now for you know speed and Energy + + + align:start position:0% +design now for you know speed and Energy +Efficiency and you know the sort of + + align:start position:0% +Efficiency and you know the sort of + + + align:start position:0% +Efficiency and you know the sort of +things that were really hard to do 20 30 + + align:start position:0% +things that were really hard to do 20 30 + + + align:start position:0% +things that were really hard to do 20 30 +50 years ago it's pretty standard + + align:start position:0% +50 years ago it's pretty standard + + + align:start position:0% +50 years ago it's pretty standard +practice now you know how do you design + + align:start position:0% +practice now you know how do you design + + + align:start position:0% +practice now you know how do you design +for optimal interoperability we don't + + align:start position:0% +for optimal interoperability we don't + + + align:start position:0% +for optimal interoperability we don't +quite know yet but we're we're finding + + align:start position:0% +quite know yet but we're we're finding + + + align:start position:0% +quite know yet but we're we're finding +our way and so uh believe is that you + + align:start position:0% +our way and so uh believe is that you + + + align:start position:0% +our way and so uh believe is that you +know those especially the life cycle + + align:start position:0% +know those especially the life cycle + + + align:start position:0% +know those especially the life cycle +properties on the outer periphery of + + align:start position:0% +properties on the outer periphery of + + + align:start position:0% +properties on the outer periphery of +this chart the those are the ones that + + align:start position:0% +this chart the those are the ones that + + + align:start position:0% +this chart the those are the ones that +that need more work and those are the + + align:start position:0% +that need more work and those are the + + + align:start position:0% +that need more work and those are the +ones that were really learning how to + + align:start position:0% + + + + align:start position:0% + +operationalize does that make + + align:start position:0% +operationalize does that make + + + align:start position:0% +operationalize does that make +sense uh yeah thanks that makes + + align:start position:0% +sense uh yeah thanks that makes + + + align:start position:0% +sense uh yeah thanks that makes +sense okay good so uh let me talk about + + align:start position:0% +sense okay good so uh let me talk about + + + align:start position:0% +sense okay good so uh let me talk about +method two so this was basically uh + + align:start position:0% +method two so this was basically uh + + + align:start position:0% +method two so this was basically uh +trying to get to how how do people how + + align:start position:0% +trying to get to how how do people how + + + align:start position:0% +trying to get to how how do people how +do humans there sem semantics means the + + align:start position:0% +do humans there sem semantics means the + + + align:start position:0% +do humans there sem semantics means the +meaning of words right semantics is the + + align:start position:0% +meaning of words right semantics is the + + + align:start position:0% +meaning of words right semantics is the +science of the meaning of words how do + + align:start position:0% +science of the meaning of words how do + + + align:start position:0% +science of the meaning of words how do +they what how do they interpret these + + align:start position:0% +they what how do they interpret these + + + align:start position:0% +they what how do they interpret these +life cycle properties and um and so here + + align:start position:0% +life cycle properties and um and so here + + + align:start position:0% +life cycle properties and um and so here +humans have a deep and possibly varied + + align:start position:0% +humans have a deep and possibly varied + + + align:start position:0% +humans have a deep and possibly varied +understanding of the semantics of these + + align:start position:0% +understanding of the semantics of these + + + align:start position:0% +understanding of the semantics of these +life cycle properties so what was done + + align:start position:0% +life cycle properties so what was done + + + align:start position:0% +life cycle properties so what was done +here was that a list of 15 life cycle + + align:start position:0% +here was that a list of 15 life cycle + + + align:start position:0% +here was that a list of 15 life cycle +properties many of them are overlapping + + align:start position:0% +properties many of them are overlapping + + + align:start position:0% +properties many of them are overlapping +with the ones you saw earlier were + + align:start position:0% +with the ones you saw earlier were + + + align:start position:0% +with the ones you saw earlier were +presented um and then the challenge was + + align:start position:0% +presented um and then the challenge was + + + align:start position:0% +presented um and then the challenge was +to the the question that these uh four + + align:start position:0% +to the the question that these uh four + + + align:start position:0% +to the the question that these uh four +groups 12 12 participants four groups + + align:start position:0% +groups 12 12 participants four groups + + + align:start position:0% +groups 12 12 participants four groups +had to say is there a hierarchy here you + + align:start position:0% +had to say is there a hierarchy here you + + + align:start position:0% +had to say is there a hierarchy here you +know are some higher level life cycle + + align:start position:0% +know are some higher level life cycle + + + align:start position:0% +know are some higher level life cycle +properties are some of them lower level + + align:start position:0% +properties are some of them lower level + + + align:start position:0% +properties are some of them lower level +properties that support these so there + + align:start position:0% +properties that support these so there + + + align:start position:0% +properties that support these so there +was round one find the parent child + + align:start position:0% +was round one find the parent child + + + align:start position:0% +was round one find the parent child +relationships described these interviews + + align:start position:0% +relationships described these interviews + + + align:start position:0% +relationships described these interviews +and then a second round so here's + + align:start position:0% +and then a second round so here's + + + align:start position:0% +and then a second round so here's +essentially um what was what was the + + align:start position:0% +essentially um what was what was the + + + align:start position:0% +essentially um what was what was the +results of the first round so four + + align:start position:0% +results of the first round so four + + + align:start position:0% +results of the first round so four +different groups so each of them + + align:start position:0% +different groups so each of them + + + align:start position:0% +different groups so each of them +basically uh came up with its own + + align:start position:0% +basically uh came up with its own + + + align:start position:0% +basically uh came up with its own +version of a hierarchy they didn't talk + + align:start position:0% +version of a hierarchy they didn't talk + + + align:start position:0% +version of a hierarchy they didn't talk +to each other they were firewalled from + + align:start position:0% +to each other they were firewalled from + + + align:start position:0% +to each other they were firewalled from +each other and in all cases this notion + + align:start position:0% +each other and in all cases this notion + + + align:start position:0% +each other and in all cases this notion +of value robustness came out on top so + + align:start position:0% +of value robustness came out on top so + + + align:start position:0% +of value robustness came out on top so +value robustness means the system should + + align:start position:0% +value robustness means the system should + + + align:start position:0% +value robustness means the system should +deliver value right to the stakeholders + + align:start position:0% +deliver value right to the stakeholders + + + align:start position:0% +deliver value right to the stakeholders +despite uh failures you know + + align:start position:0% +despite uh failures you know + + + align:start position:0% +despite uh failures you know +environmental changes so value delivery + + align:start position:0% +environmental changes so value delivery + + + align:start position:0% +environmental changes so value delivery +of the system is the top the most + + align:start position:0% +of the system is the top the most + + + align:start position:0% +of the system is the top the most +important thing then what's different + + align:start position:0% +important thing then what's different + + + align:start position:0% +important thing then what's different +here is you know how do you achieve that + + align:start position:0% +here is you know how do you achieve that + + + align:start position:0% +here is you know how do you achieve that +uh so for example you see group one had + + align:start position:0% +uh so for example you see group one had + + + align:start position:0% +uh so for example you see group one had +uh + + align:start position:0% +uh + + + align:start position:0% +uh +robustness uh and changeability so + + align:start position:0% +robustness uh and changeability so + + + align:start position:0% +robustness uh and changeability so +robustness typically means even if you + + align:start position:0% +robustness typically means even if you + + + align:start position:0% +robustness typically means even if you +don't make any changes to the system it + + align:start position:0% +don't make any changes to the system it + + + align:start position:0% +don't make any changes to the system it +should continue you know it should be + + align:start position:0% +should continue you know it should be + + + align:start position:0% +should continue you know it should be +survivable it should be + + align:start position:0% +survivable it should be + + + align:start position:0% +survivable it should be +versatile uh changeable means to + + align:start position:0% +versatile uh changeable means to + + + align:start position:0% +versatile uh changeable means to +actually modify the system over its life + + align:start position:0% +actually modify the system over its life + + + align:start position:0% +actually modify the system over its life +and then we have lower level properties + + align:start position:0% +and then we have lower level properties + + + align:start position:0% +and then we have lower level properties +like modularity or reconfigurability and + + align:start position:0% +like modularity or reconfigurability and + + + align:start position:0% +like modularity or reconfigurability and +you know there were differences between + + align:start position:0% +you know there were differences between + + + align:start position:0% +you know there were differences between +the groups but um not not as big as you + + align:start position:0% +the groups but um not not as big as you + + + align:start position:0% +the groups but um not not as big as you +might think so in the second round as a + + align:start position:0% +might think so in the second round as a + + + align:start position:0% +might think so in the second round as a +result of the second round then this um + + align:start position:0% +result of the second round then this um + + + align:start position:0% +result of the second round then this um +so-called means to ends hierarchy was + + align:start position:0% +so-called means to ends hierarchy was + + + align:start position:0% +so-called means to ends hierarchy was +constructed so means means you know + + align:start position:0% +constructed so means means you know + + + align:start position:0% +constructed so means means you know +these are the enabling life cycle + + align:start position:0% +these are the enabling life cycle + + + align:start position:0% +these are the enabling life cycle +properties and ends means this is the + + align:start position:0% +properties and ends means this is the + + + align:start position:0% +properties and ends means this is the +final soort of this is really what you + + align:start position:0% +final soort of this is really what you + + + align:start position:0% +final soort of this is really what you +want to achieve and so this was the + + align:start position:0% +want to achieve and so this was the + + + align:start position:0% +want to achieve and so this was the +result of that uh so again at the top we + + align:start position:0% +result of that uh so again at the top we + + + align:start position:0% +result of that uh so again at the top we +have this notion of value robustness and + + align:start position:0% +have this notion of value robustness and + + + align:start position:0% +have this notion of value robustness and +this is achieved by a combination of + + align:start position:0% +this is achieved by a combination of + + + align:start position:0% +this is achieved by a combination of +survivability robustness and + + align:start position:0% +survivability robustness and + + + align:start position:0% +survivability robustness and +changeability and then these in turn are + + align:start position:0% +changeability and then these in turn are + + + align:start position:0% +changeability and then these in turn are +achieved by lower level life cycle + + align:start position:0% +achieved by lower level life cycle + + + align:start position:0% +achieved by lower level life cycle +properties and then at the lowest level + + align:start position:0% +properties and then at the lowest level + + + align:start position:0% +properties and then at the lowest level +we have things like interoperability + + align:start position:0% +we have things like interoperability + + + align:start position:0% +we have things like interoperability +modularity reconfigurability and so + + align:start position:0% +modularity reconfigurability and so + + + align:start position:0% +modularity reconfigurability and so +forth okay and the the difference + + align:start position:0% +forth okay and the the difference + + + align:start position:0% +forth okay and the the difference +between the solid line and the dash + + align:start position:0% +between the solid line and the dash + + + align:start position:0% +between the solid line and the dash +lines here is that if it's a solid line + + align:start position:0% +lines here is that if it's a solid line + + + align:start position:0% +lines here is that if it's a solid line +and these are directed + + align:start position:0% +and these are directed + + + align:start position:0% +and these are directed +arrows that means that three three or + + align:start position:0% +arrows that means that three three or + + + align:start position:0% +arrows that means that three three or +four out of four groups right so the + + align:start position:0% +four out of four groups right so the + + + align:start position:0% +four out of four groups right so the +majority of groups had this as a + + align:start position:0% +majority of groups had this as a + + + align:start position:0% +majority of groups had this as a +particular CH parent child relationship + + align:start position:0% +particular CH parent child relationship + + + align:start position:0% +particular CH parent child relationship +and if it's a dash line it means only + + align:start position:0% +and if it's a dash line it means only + + + align:start position:0% +and if it's a dash line it means only +two out of four and if it's only one out + + align:start position:0% +two out of four and if it's only one out + + + align:start position:0% +two out of four and if it's only one out +of four it's not shown here okay so this + + align:start position:0% +of four it's not shown here okay so this + + + align:start position:0% +of four it's not shown here okay so this +is kind of a combined results across the + + align:start position:0% +is kind of a combined results across the + + + align:start position:0% +is kind of a combined results across the +four + + align:start position:0% +four + + + align:start position:0% +four +groups so so um you know what do we take + + align:start position:0% +groups so so um you know what do we take + + + align:start position:0% +groups so so um you know what do we take +from this so first of all life cycle + + align:start position:0% +from this so first of all life cycle + + + align:start position:0% +from this so first of all life cycle +properties are absolutely critical you + + align:start position:0% +properties are absolutely critical you + + + align:start position:0% +properties are absolutely critical you +you'll find this in in in mission + + align:start position:0% +you'll find this in in in mission + + + align:start position:0% +you'll find this in in in mission +statements you know you'll find it in + + align:start position:0% +statements you know you'll find it in + + + align:start position:0% +statements you know you'll find it in +even in advertising right a lot of + + align:start position:0% +even in advertising right a lot of + + + align:start position:0% +even in advertising right a lot of +companies say we have we have a robust + + align:start position:0% +companies say we have we have a robust + + + align:start position:0% +companies say we have we have a robust +solution we have a sustainable system we + + align:start position:0% +solution we have a sustainable system we + + + align:start position:0% +solution we have a sustainable system we +have resilient networks so it it really + + align:start position:0% +have resilient networks so it it really + + + align:start position:0% +have resilient networks so it it really +is a huge huge selling point it's very + + align:start position:0% +is a huge huge selling point it's very + + + align:start position:0% +is a huge huge selling point it's very +critical what I encourage you to do as + + align:start position:0% +critical what I encourage you to do as + + + align:start position:0% +critical what I encourage you to do as +system Engineers is take a critical look + + align:start position:0% +system Engineers is take a critical look + + + align:start position:0% +system Engineers is take a critical look +at this and say well what does that how + + align:start position:0% +at this and say well what does that how + + + align:start position:0% +at this and say well what does that how +resilient is resilient you know how many + + align:start position:0% +resilient is resilient you know how many + + + align:start position:0% +resilient is resilient you know how many +subsequent failures you know of the + + align:start position:0% +subsequent failures you know of the + + + align:start position:0% +subsequent failures you know of the +system can you tolerate uh + + align:start position:0% +system can you tolerate uh + + + align:start position:0% +system can you tolerate uh +sustainability what does it mean in + + align:start position:0% +sustainability what does it mean in + + + align:start position:0% +sustainability what does it mean in +terms of you know kilowatt hours per + + align:start position:0% +terms of you know kilowatt hours per + + + align:start position:0% +terms of you know kilowatt hours per +hour of usage you have to get down to + + align:start position:0% +hour of usage you have to get down to + + + align:start position:0% +hour of usage you have to get down to +the details to start quantifying what + + align:start position:0% +the details to start quantifying what + + + align:start position:0% +the details to start quantifying what +these life cycle properties mean and + + align:start position:0% +these life cycle properties mean and + + + align:start position:0% +these life cycle properties mean and +compare them among + + align:start position:0% +compare them among + + + align:start position:0% +compare them among +systems uh despite differ differences + + align:start position:0% +systems uh despite differ differences + + + align:start position:0% +systems uh despite differ differences +this these two methods that we just + + align:start position:0% +this these two methods that we just + + + align:start position:0% +this these two methods that we just +looked at so one is the prevalence + + align:start position:0% +looked at so one is the prevalence + + + align:start position:0% +looked at so one is the prevalence +analysis and the other one is the um you + + align:start position:0% +analysis and the other one is the um you + + + align:start position:0% +analysis and the other one is the um you +know the the human semantic exercise + + align:start position:0% +know the the human semantic exercise + + + align:start position:0% +know the the human semantic exercise +despite differences the high level + + align:start position:0% +despite differences the high level + + + align:start position:0% +despite differences the high level +conclusions were similar so some ilities + + align:start position:0% +conclusions were similar so some ilities + + + align:start position:0% +conclusions were similar so some ilities +are closely related to each other and + + align:start position:0% +are closely related to each other and + + + align:start position:0% +are closely related to each other and +form semantic sets meaning they're + + align:start position:0% +form semantic sets meaning they're + + + align:start position:0% +form semantic sets meaning they're +they're tied together by both synonymy + + align:start position:0% +they're tied together by both synonymy + + + align:start position:0% +they're tied together by both synonymy +or polyi relationships synonymy means + + align:start position:0% +or polyi relationships synonymy means + + + align:start position:0% +or polyi relationships synonymy means +they essentially mean the same they're + + align:start position:0% +they essentially mean the same they're + + + align:start position:0% +they essentially mean the same they're +synonymous they essentially mean the + + align:start position:0% +synonymous they essentially mean the + + + align:start position:0% +synonymous they essentially mean the +same thing polyi means it is one word + + align:start position:0% +same thing polyi means it is one word + + + align:start position:0% +same thing polyi means it is one word +but it means can mean have possible sub + + align:start position:0% +but it means can mean have possible sub + + + align:start position:0% +but it means can mean have possible sub +meanings right so so uh the idea of + + align:start position:0% +meanings right so so uh the idea of + + + align:start position:0% +meanings right so so uh the idea of +groups of of semantic sets and um those + + align:start position:0% +groups of of semantic sets and um those + + + align:start position:0% +groups of of semantic sets and um those +uh those groups essentially are + + align:start position:0% +uh those groups essentially are + + + align:start position:0% +uh those groups essentially are +robustness so this is the ability of the + + align:start position:0% +robustness so this is the ability of the + + + align:start position:0% +robustness so this is the ability of the +system to perform its job despite either + + align:start position:0% +system to perform its job despite either + + + align:start position:0% +system to perform its job despite either +internal or exogenous disturbances right + + align:start position:0% +internal or exogenous disturbances right + + + align:start position:0% +internal or exogenous disturbances right +that's robustness flexible or changeable + + align:start position:0% +that's robustness flexible or changeable + + + align:start position:0% +that's robustness flexible or changeable +which means that um you can modify the + + align:start position:0% +which means that um you can modify the + + + align:start position:0% +which means that um you can modify the +system easily you know if you operate + + align:start position:0% +system easily you know if you operate + + + align:start position:0% +system easily you know if you operate +the system for a while and then you + + align:start position:0% +the system for a while and then you + + + align:start position:0% +the system for a while and then you +realize ah I I need the system to do + + align:start position:0% +realize ah I I need the system to do + + + align:start position:0% +realize ah I I need the system to do +something else or I need to ad adapt it + + align:start position:0% +something else or I need to ad adapt it + + + align:start position:0% +something else or I need to ad adapt it +or make it bigger or make it smaller or + + align:start position:0% +or make it bigger or make it smaller or + + + align:start position:0% +or make it bigger or make it smaller or +add some functions so you would modify + + align:start position:0% +add some functions so you would modify + + + align:start position:0% +add some functions so you would modify +the system and that's flexibility or + + align:start position:0% +the system and that's flexibility or + + + align:start position:0% +the system and that's flexibility or +changeability and then resilient and + + align:start position:0% +changeability and then resilient and + + + align:start position:0% +changeability and then resilient and +survivable is very specifically the + + align:start position:0% +survivable is very specifically the + + + align:start position:0% +survivable is very specifically the +ability of the system to continue + + align:start position:0% +ability of the system to continue + + + align:start position:0% +ability of the system to continue +performing despite uh failures or + + align:start position:0% +performing despite uh failures or + + + align:start position:0% +performing despite uh failures or +attacks right that's what resilience + + align:start position:0% +attacks right that's what resilience + + + align:start position:0% +attacks right that's what resilience +really means and so those seem to be the + + align:start position:0% +really means and so those seem to be the + + + align:start position:0% +really means and so those seem to be the +big three semantic clusters that we see + + align:start position:0% +big three semantic clusters that we see + + + align:start position:0% +big three semantic clusters that we see +in life cycle properties and then the + + align:start position:0% +in life cycle properties and then the + + + align:start position:0% +in life cycle properties and then the +the third Point here is there appears to + + align:start position:0% +the third Point here is there appears to + + + align:start position:0% +the third Point here is there appears to +be a hierarchy of life cycle properties + + align:start position:0% +be a hierarchy of life cycle properties + + + align:start position:0% +be a hierarchy of life cycle properties +with two or three levels where we have + + align:start position:0% +with two or three levels where we have + + + align:start position:0% +with two or three levels where we have +lower level properties of systems like + + align:start position:0% +lower level properties of systems like + + + align:start position:0% +lower level properties of systems like +modularity for example really your + + align:start position:0% +modularity for example really your + + + align:start position:0% +modularity for example really your +customer probably does not care about + + align:start position:0% +customer probably does not care about + + + align:start position:0% +customer probably does not care about +modularity right if you advertise the + + align:start position:0% +modularity right if you advertise the + + + align:start position:0% +modularity right if you advertise the +modularity of the product you know some + + align:start position:0% +modularity of the product you know some + + + align:start position:0% +modularity of the product you know some +of the more educated uh you know some of + + align:start position:0% +of the more educated uh you know some of + + + align:start position:0% +of the more educated uh you know some of +the more technically Savvy customers + + align:start position:0% +the more technically Savvy customers + + + align:start position:0% +the more technically Savvy customers +they may understand what that means but + + align:start position:0% +they may understand what that means but + + + align:start position:0% +they may understand what that means but +most of your customers really won't + + align:start position:0% +most of your customers really won't + + + align:start position:0% +most of your customers really won't +appreciate modularity because it's kind + + align:start position:0% +appreciate modularity because it's kind + + + align:start position:0% +appreciate modularity because it's kind +of a low-level form oriented technical + + align:start position:0% +of a low-level form oriented technical + + + align:start position:0% +of a low-level form oriented technical +property of the system but what what + + align:start position:0% +property of the system but what what + + + align:start position:0% +property of the system but what what +they will appreciate is the ability of + + align:start position:0% +they will appreciate is the ability of + + + align:start position:0% +they will appreciate is the ability of +the system to be reconfigured or adapted + + align:start position:0% +the system to be reconfigured or adapted + + + align:start position:0% +the system to be reconfigured or adapted +for different uses right so + + align:start position:0% +for different uses right so + + + align:start position:0% +for different uses right so +interoperability modularity Etc are + + align:start position:0% +interoperability modularity Etc are + + + align:start position:0% +interoperability modularity Etc are +lower level life cycle properties that + + align:start position:0% +lower level life cycle properties that + + + align:start position:0% +lower level life cycle properties that +act as enablers of the higher level life + + align:start position:0% +act as enablers of the higher level life + + + align:start position:0% +act as enablers of the higher level life +cycle properties okay and so future work + + align:start position:0% +cycle properties okay and so future work + + + align:start position:0% +cycle properties okay and so future work +uh future work in this area is to both + + align:start position:0% +uh future work in this area is to both + + + align:start position:0% +uh future work in this area is to both +um to you know to apply the these + + align:start position:0% +um to you know to apply the these + + + align:start position:0% +um to you know to apply the these +methods to a broader set abilities + + align:start position:0% +methods to a broader set abilities + + + align:start position:0% +methods to a broader set abilities +larger group of test subjects you know + + align:start position:0% +larger group of test subjects you know + + + align:start position:0% +larger group of test subjects you know +more data but also from a practical + + align:start position:0% +more data but also from a practical + + + align:start position:0% +more data but also from a practical +standpoint to to operationalize better + + align:start position:0% +standpoint to to operationalize better + + + align:start position:0% +standpoint to to operationalize better +how do we write requirements how do we + + align:start position:0% +how do we write requirements how do we + + + align:start position:0% +how do we write requirements how do we +actually design for these life cycle + + align:start position:0% +actually design for these life cycle + + + align:start position:0% +actually design for these life cycle +properties like resilience you know + + align:start position:0% +properties like resilience you know + + + align:start position:0% +properties like resilience you know +flexibility changeability how do you + + align:start position:0% +flexibility changeability how do you + + + align:start position:0% +flexibility changeability how do you +really design it so go from the keyword + + align:start position:0% +really design it so go from the keyword + + + align:start position:0% +really design it so go from the keyword +to real engineering by operationalizing + + align:start position:0% +to real engineering by operationalizing + + + align:start position:0% +to real engineering by operationalizing +the the the subattributes or factor of + + align:start position:0% +the the the subattributes or factor of + + + align:start position:0% +the the the subattributes or factor of +these systems okay so that's uh quick + + align:start position:0% +these systems okay so that's uh quick + + + align:start position:0% +these systems okay so that's uh quick +summary of life you know I could go on + + align:start position:0% +summary of life you know I could go on + + + align:start position:0% +summary of life you know I could go on +for hours about this uh this is I'm very + + align:start position:0% +for hours about this uh this is I'm very + + + align:start position:0% +for hours about this uh this is I'm very +passionate about this topic and I will + + align:start position:0% +passionate about this topic and I will + + + align:start position:0% +passionate about this topic and I will +say that um you know people who have + + align:start position:0% +say that um you know people who have + + + align:start position:0% +say that um you know people who have +dealt with large complex systems you + + align:start position:0% +dealt with large complex systems you + + + align:start position:0% +dealt with large complex systems you +know whether you're operating the + + align:start position:0% +know whether you're operating the + + + align:start position:0% +know whether you're operating the +transportation system of a city or you + + align:start position:0% +transportation system of a city or you + + + align:start position:0% +transportation system of a city or you +know in Airline operations or you know + + align:start position:0% +know in Airline operations or you know + + + align:start position:0% +know in Airline operations or you know +you're running the it infrastructure of + + align:start position:0% +you're running the it infrastructure of + + + align:start position:0% +you're running the it infrastructure of +a major + + align:start position:0% +a major + + + align:start position:0% +a major +corporation these words uh + + align:start position:0% +corporation these words uh + + + align:start position:0% +corporation these words uh +these words are real these words are you + + align:start position:0% +these words are real these words are you + + + align:start position:0% +these words are real these words are you +know real dollars real challenges this + + align:start position:0% +know real dollars real challenges this + + + align:start position:0% +know real dollars real challenges this +is really where the action is in in a + + align:start position:0% +is really where the action is in in a + + + align:start position:0% +is really where the action is in in a +lot of these large complex + + align:start position:0% + + + + align:start position:0% + +systems okay any any comments or + + align:start position:0% +systems okay any any comments or + + + align:start position:0% +systems okay any any comments or +questions about uh life cycle properties + + align:start position:0% +questions about uh life cycle properties + + + align:start position:0% +questions about uh life cycle properties +how what they are how they relate to + + align:start position:0% +how what they are how they relate to + + + align:start position:0% +how what they are how they relate to +each other why they're important bulker + + align:start position:0% +each other why they're important bulker + + + align:start position:0% +each other why they're important bulker +did you want to maybe say something okay + + align:start position:0% +did you want to maybe say something okay + + + align:start position:0% +did you want to maybe say something okay +all right so let me talk about uh try to + + align:start position:0% +all right so let me talk about uh try to + + + align:start position:0% +all right so let me talk about uh try to +make this a little more real uh let me + + align:start position:0% +make this a little more real uh let me + + + align:start position:0% +make this a little more real uh let me +talk about a case study very specific + + align:start position:0% +talk about a case study very specific + + + align:start position:0% +talk about a case study very specific +case study about uh communication + + align:start position:0% +case study about uh communication + + + align:start position:0% +case study about uh communication +satellite constellations and this is the + + align:start position:0% +satellite constellations and this is the + + + align:start position:0% +satellite constellations and this is the +second paper uh that underlies today's + + align:start position:0% +second paper uh that underlies today's + + + align:start position:0% +second paper uh that underlies today's +lecture and so let me give you a little + + align:start position:0% +lecture and so let me give you a little + + + align:start position:0% +lecture and so let me give you a little +context for this first uh so this this + + align:start position:0% +context for this first uh so this this + + + align:start position:0% +context for this first uh so this this +uh work here was originally published uh + + align:start position:0% +uh work here was originally published uh + + + align:start position:0% +uh work here was originally published uh +about a decade ago in March 2004 and + + align:start position:0% +about a decade ago in March 2004 and + + + align:start position:0% +about a decade ago in March 2004 and +that was a few years after um idium and + + align:start position:0% +that was a few years after um idium and + + + align:start position:0% +that was a few years after um idium and +Global star these are the two well-known + + align:start position:0% +Global star these are the two well-known + + + align:start position:0% +Global star these are the two well-known +communication satellite constellations + + align:start position:0% +communication satellite constellations + + + align:start position:0% +communication satellite constellations +had had been launched and I have to give + + align:start position:0% +had had been launched and I have to give + + + align:start position:0% +had had been launched and I have to give +you a little context when I first came + + align:start position:0% +you a little context when I first came + + + align:start position:0% +you a little context when I first came +to MIT in the mid 1990s there was a huge + + align:start position:0% +to MIT in the mid 1990s there was a huge + + + align:start position:0% +to MIT in the mid 1990s there was a huge +interest in this area of satellite + + align:start position:0% +interest in this area of satellite + + + align:start position:0% +interest in this area of satellite +constellations you know commercially + + align:start position:0% +constellations you know commercially + + + align:start position:0% +constellations you know commercially +scientifically um you know in fact you + + align:start position:0% +scientifically um you know in fact you + + + align:start position:0% +scientifically um you know in fact you +know the the impression was there were + + align:start position:0% +know the the impression was there were + + + align:start position:0% +know the the impression was there were +so many applications for satellite + + align:start position:0% +so many applications for satellite + + + align:start position:0% +so many applications for satellite +constellations filed that you know we're + + align:start position:0% +constellations filed that you know we're + + + align:start position:0% +constellations filed that you know we're +going to have so many satellites up + + align:start position:0% +going to have so many satellites up + + + align:start position:0% +going to have so many satellites up +there you won't even see the sun anymore + + align:start position:0% +there you won't even see the sun anymore + + + align:start position:0% +there you won't even see the sun anymore +right it was just like thousands and + + align:start position:0% +right it was just like thousands and + + + align:start position:0% +right it was just like thousands and +thousands of satellites and irium and + + align:start position:0% +thousands of satellites and irium and + + + align:start position:0% +thousands of satellites and irium and +Global star were really the first two + + align:start position:0% +Global star were really the first two + + + align:start position:0% +Global star were really the first two +constellations that were fully developed + + align:start position:0% +constellations that were fully developed + + + align:start position:0% +constellations that were fully developed +launched and both of them uh failed + + align:start position:0% +launched and both of them uh failed + + + align:start position:0% +launched and both of them uh failed +commercially within a really short time + + align:start position:0% +commercially within a really short time + + + align:start position:0% +commercially within a really short time +a couple years and so after this + + align:start position:0% +a couple years and so after this + + + align:start position:0% +a couple years and so after this +happened the whole market and interest + + align:start position:0% +happened the whole market and interest + + + align:start position:0% +happened the whole market and interest +in Satellite constellations + + align:start position:0% +in Satellite constellations + + + align:start position:0% +in Satellite constellations +collapsed uh for a long time uh until + + align:start position:0% +collapsed uh for a long time uh until + + + align:start position:0% +collapsed uh for a long time uh until +about you know few years ago two or 3 + + align:start position:0% +about you know few years ago two or 3 + + + align:start position:0% +about you know few years ago two or 3 +years ago now you know people talk about + + align:start position:0% +years ago now you know people talk about + + + align:start position:0% +years ago now you know people talk about +these constellations again you know uh + + align:start position:0% +these constellations again you know uh + + + align:start position:0% +these constellations again you know uh +constellations of cube sets uh uh + + align:start position:0% +constellations of cube sets uh uh + + + align:start position:0% +constellations of cube sets uh uh +iridium next you know there's sort of a + + align:start position:0% +iridium next you know there's sort of a + + + align:start position:0% +iridium next you know there's sort of a +new enthusiasm new wave of enthusiasm + + align:start position:0% +new enthusiasm new wave of enthusiasm + + + align:start position:0% +new enthusiasm new wave of enthusiasm +for constellation so um so this this + + align:start position:0% +for constellation so um so this this + + + align:start position:0% +for constellation so um so this this +paper and this case that I want to tell + + align:start position:0% +paper and this case that I want to tell + + + align:start position:0% +paper and this case that I want to tell +you about is really about the first + + align:start position:0% +you about is really about the first + + + align:start position:0% +you about is really about the first +wave and in terms of the Ides what I the + + align:start position:0% +wave and in terms of the Ides what I the + + + align:start position:0% +wave and in terms of the Ides what I the +the one that I'm that I'm um that I like + + align:start position:0% +the one that I'm that I'm um that I like + + + align:start position:0% +the one that I'm that I'm um that I like +to explain to you about here is + + align:start position:0% +to explain to you about here is + + + align:start position:0% +to explain to you about here is +flexibility and scalability rather than + + align:start position:0% +flexibility and scalability rather than + + + align:start position:0% +flexibility and scalability rather than +thinking about a system + + align:start position:0% +thinking about a system + + + align:start position:0% +thinking about a system +something that you design and build all + + align:start position:0% +something that you design and build all + + + align:start position:0% +something that you design and build all +at once how do you design a system such + + align:start position:0% +at once how do you design a system such + + + align:start position:0% +at once how do you design a system such +that you can gradually deploy it we call + + align:start position:0% +that you can gradually deploy it we call + + + align:start position:0% +that you can gradually deploy it we call +that stage deployment approach and + + align:start position:0% +that stage deployment approach and + + + align:start position:0% +that stage deployment approach and +what's the benefit of that okay so + + align:start position:0% +what's the benefit of that okay so + + + align:start position:0% +what's the benefit of that okay so +here's some uh pictures uh you see on + + align:start position:0% +here's some uh pictures uh you see on + + + align:start position:0% +here's some uh pictures uh you see on +the right side this is what the original + + align:start position:0% +the right side this is what the original + + + align:start position:0% +the right side this is what the original +aridium satellites look like they + + align:start position:0% +aridium satellites look like they + + + align:start position:0% +aridium satellites look like they +actually use uh phased array antennas uh + + align:start position:0% +actually use uh phased array antennas uh + + + align:start position:0% +actually use uh phased array antennas uh +they actually both use phased array + + align:start position:0% +they actually both use phased array + + + align:start position:0% +they actually both use phased array +antennas so you have individual elements + + align:start position:0% +antennas so you have individual elements + + + align:start position:0% +antennas so you have individual elements +here and by differentially phasing the + + align:start position:0% +here and by differentially phasing the + + + align:start position:0% +here and by differentially phasing the +signal you can actually steer the beam + + align:start position:0% +signal you can actually steer the beam + + + align:start position:0% +signal you can actually steer the beam +so this was a very new technology at the + + align:start position:0% +so this was a very new technology at the + + + align:start position:0% +so this was a very new technology at the +time and then the global Star Satellite + + align:start position:0% +time and then the global Star Satellite + + + align:start position:0% +time and then the global Star Satellite +uh shown at the lower um the lower + + align:start position:0% +uh shown at the lower um the lower + + + align:start position:0% +uh shown at the lower um the lower +picture here's a little bit of data uh + + align:start position:0% +picture here's a little bit of data uh + + + align:start position:0% +picture here's a little bit of data uh +both of these were launched in the late + + align:start position:0% +both of these were launched in the late + + + align:start position:0% +both of these were launched in the late +1990s uh idium has 66 satellites Global + + align:start position:0% +1990s uh idium has 66 satellites Global + + + align:start position:0% +1990s uh idium has 66 satellites Global +star 48 uh idium is a polar + + align:start position:0% +star 48 uh idium is a polar + + + align:start position:0% +star 48 uh idium is a polar +constellation so the satellites go + + align:start position:0% +constellation so the satellites go + + + align:start position:0% +constellation so the satellites go +almost directly over the poles um global + + align:start position:0% +almost directly over the poles um global + + + align:start position:0% +almost directly over the poles um global +star is a walker constellation so it's + + align:start position:0% +star is a walker constellation so it's + + + align:start position:0% +star is a walker constellation so it's +inclined doesn't quite give you full + + align:start position:0% +inclined doesn't quite give you full + + + align:start position:0% +inclined doesn't quite give you full +Global coverage it's about plus orus 70° + + align:start position:0% +Global coverage it's about plus orus 70° + + + align:start position:0% +Global coverage it's about plus orus 70° +so you can't use Global star at the + + align:start position:0% +so you can't use Global star at the + + + align:start position:0% +so you can't use Global star at the +poles uh the altitudes are a bit + + align:start position:0% +poles uh the altitudes are a bit + + + align:start position:0% +poles uh the altitudes are a bit +different too idium is at 780 km while + + align:start position:0% +different too idium is at 780 km while + + + align:start position:0% +different too idium is at 780 km while +uh Global star is at 1,400 which um um + + align:start position:0% +uh Global star is at 1,400 which um um + + + align:start position:0% +uh Global star is at 1,400 which um um +who's I know at least one or two of you + + align:start position:0% +who's I know at least one or two of you + + + align:start position:0% +who's I know at least one or two of you +are working on the Van Allen the Van + + align:start position:0% +are working on the Van Allen the Van + + + align:start position:0% +are working on the Van Allen the Van +Allen belt mission right the cube sets + + align:start position:0% +Allen belt mission right the cube sets + + + align:start position:0% +Allen belt mission right the cube sets +to measure the Van Allen belts somebody + + align:start position:0% +to measure the Van Allen belts somebody + + + align:start position:0% +to measure the Van Allen belts somebody +mentioned that today who was that no did + + align:start position:0% +mentioned that today who was that no did + + + align:start position:0% +mentioned that today who was that no did +I hear that + + align:start position:0% +I hear that + + + align:start position:0% +I hear that +wrong it was mentioned right so who is + + align:start position:0% +wrong it was mentioned right so who is + + + align:start position:0% +wrong it was mentioned right so who is +that oh no and he's not here huh you see + + align:start position:0% +that oh no and he's not here huh you see + + + align:start position:0% +that oh no and he's not here huh you see +so 1400 kilomet you're actually pushing + + align:start position:0% +so 1400 kilomet you're actually pushing + + + align:start position:0% +so 1400 kilomet you're actually pushing +you're starting to push the lower edges + + align:start position:0% +you're starting to push the lower edges + + + align:start position:0% +you're starting to push the lower edges +of the Van Allen belt so one of the big + + align:start position:0% +of the Van Allen belt so one of the big + + + align:start position:0% +of the Van Allen belt so one of the big +you know in in in some sense it's easier + + align:start position:0% +you know in in in some sense it's easier + + + align:start position:0% +you know in in in some sense it's easier +to be higher because you need fewer + + align:start position:0% +to be higher because you need fewer + + + align:start position:0% +to be higher because you need fewer +satellites to cover the whole Earth + + align:start position:0% +satellites to cover the whole Earth + + + align:start position:0% +satellites to cover the whole Earth +Earth but the higher you go the more + + align:start position:0% +Earth but the higher you go the more + + + align:start position:0% +Earth but the higher you go the more +exposed you are to the radiation + + align:start position:0% +exposed you are to the radiation + + + align:start position:0% +exposed you are to the radiation +environment you get closer to the Van + + align:start position:0% +environment you get closer to the Van + + + align:start position:0% +environment you get closer to the Van +Allen belt so that's the big tradeoff + + align:start position:0% +Allen belt so that's the big tradeoff + + + align:start position:0% +Allen belt so that's the big tradeoff +there you know the mass of these + + align:start position:0% +there you know the mass of these + + + align:start position:0% +there you know the mass of these +satellites they're between you know 450 + + align:start position:0% +satellites they're between you know 450 + + + align:start position:0% +satellites they're between you know 450 +and 700 kg transmitter power around 400 + + align:start position:0% +and 700 kg transmitter power around 400 + + + align:start position:0% +and 700 kg transmitter power around 400 +watts you know which is not that much if + + align:start position:0% +watts you know which is not that much if + + + align:start position:0% +watts you know which is not that much if +you think about it right that's four + + align:start position:0% +you think about it right that's four + + + align:start position:0% +you think about it right that's four +very strong light bulbs uh the old style + + align:start position:0% +very strong light bulbs uh the old style + + + align:start position:0% +very strong light bulbs uh the old style +light + + align:start position:0% +light + + + align:start position:0% +light +buls um um and then what's very + + align:start position:0% +buls um um and then what's very + + + align:start position:0% +buls um um and then what's very +different again is the multi- access + + align:start position:0% +different again is the multi- access + + + align:start position:0% +different again is the multi- access +scheme so idium used uh time Division + + align:start position:0% +scheme so idium used uh time Division + + + align:start position:0% +scheme so idium used uh time Division +multiplexing and Global star which was + + align:start position:0% +multiplexing and Global star which was + + + align:start position:0% +multiplexing and Global star which was +supported by Qualcomm used essentially + + align:start position:0% +supported by Qualcomm used essentially + + + align:start position:0% +supported by Qualcomm used essentially +CDMA so you don't chop your frequency + + align:start position:0% +CDMA so you don't chop your frequency + + + align:start position:0% +CDMA so you don't chop your frequency +band into separate channels you use the + + align:start position:0% +band into separate channels you use the + + + align:start position:0% +band into separate channels you use the +whole the whole frequency band and then + + align:start position:0% +whole the whole frequency band and then + + + align:start position:0% +whole the whole frequency band and then +you then you use U pseudo random access + + align:start position:0% +you then you use U pseudo random access + + + align:start position:0% +you then you use U pseudo random access +codes to essentially uh deconvolve the + + align:start position:0% +codes to essentially uh deconvolve the + + + align:start position:0% +codes to essentially uh deconvolve the +signal uh for each + + align:start position:0% +signal uh for each + + + align:start position:0% +signal uh for each +Channel um the number of channels about + + align:start position:0% +Channel um the number of channels about + + + align:start position:0% +Channel um the number of channels about +72,000 about + + align:start position:0% +72,000 about + + + align:start position:0% +72,000 about +120,000 duplex channels so that you can + + align:start position:0% +120,000 duplex channels so that you can + + + align:start position:0% +120,000 duplex channels so that you can +actually duplex means you can carry on a + + align:start position:0% +actually duplex means you can carry on a + + + align:start position:0% +actually duplex means you can carry on a +two-way conversation as opposed to just + + align:start position:0% +two-way conversation as opposed to just + + + align:start position:0% +two-way conversation as opposed to just +a asynchronous and then you can see the + + align:start position:0% +a asynchronous and then you can see the + + + align:start position:0% +a asynchronous and then you can see the +data rates quite low right per Channel + + align:start position:0% +data rates quite low right per Channel + + + align:start position:0% +data rates quite low right per Channel +4.8 uh kilobits per second 2.4 4.8 9.6 + + align:start position:0% +4.8 uh kilobits per second 2.4 4.8 9.6 + + + align:start position:0% +4.8 uh kilobits per second 2.4 4.8 9.6 +for Global star it's enough for uh + + align:start position:0% +for Global star it's enough for uh + + + align:start position:0% +for Global star it's enough for uh +having a conversation and total system + + align:start position:0% +having a conversation and total system + + + align:start position:0% +having a conversation and total system +cost idium was about uh $5.7 billion and + + align:start position:0% +cost idium was about uh $5.7 billion and + + + align:start position:0% +cost idium was about uh $5.7 billion and +glas star about 3.3 three not including + + align:start position:0% +glas star about 3.3 three not including + + + align:start position:0% +glas star about 3.3 three not including +the cost of the ground stations both + + align:start position:0% +the cost of the ground stations both + + + align:start position:0% +the cost of the ground stations both +went bankrupt relatively quickly after + + align:start position:0% +went bankrupt relatively quickly after + + + align:start position:0% +went bankrupt relatively quickly after +they launched however they've been + + align:start position:0% +they launched however they've been + + + align:start position:0% +they launched however they've been +operating really since then right since + + align:start position:0% +operating really since then right since + + + align:start position:0% +operating really since then right since +this time idium next is currently under + + align:start position:0% +this time idium next is currently under + + + align:start position:0% +this time idium next is currently under +development and is scheduled to launch + + align:start position:0% +development and is scheduled to launch + + + align:start position:0% +development and is scheduled to launch +in + + align:start position:0% +in + + + align:start position:0% +in +2017 uh Global star is publicly traded + + align:start position:0% +2017 uh Global star is publicly traded + + + align:start position:0% +2017 uh Global star is publicly traded +and actually valued as a company at $ + + align:start position:0% +and actually valued as a company at $ + + + align:start position:0% +and actually valued as a company at $ +1.9 billion so they're actually both you + + align:start position:0% +1.9 billion so they're actually both you + + + align:start position:0% +1.9 billion so they're actually both you +you could almost argue that they they + + align:start position:0% +you could almost argue that they they + + + align:start position:0% +you could almost argue that they they +were at a decade ahead of their time and + + align:start position:0% +were at a decade ahead of their time and + + + align:start position:0% +were at a decade ahead of their time and +um and I want to tell you a little bit + + align:start position:0% +um and I want to tell you a little bit + + + align:start position:0% +um and I want to tell you a little bit +about the story of especially idium so + + align:start position:0% +about the story of especially idium so + + + align:start position:0% +about the story of especially idium so +here's a couple of um these are press + + align:start position:0% +here's a couple of um these are press + + + align:start position:0% +here's a couple of um these are press +releases or things that have been + + align:start position:0% +releases or things that have been + + + align:start position:0% +releases or things that have been +written in the Press so look at this one + + align:start position:0% +written in the Press so look at this one + + + align:start position:0% +written in the Press so look at this one +26th of June 1990 Motorola unveils New + + align:start position:0% +26th of June 1990 Motorola unveils New + + + align:start position:0% +26th of June 1990 Motorola unveils New +Concept for Global personal + + align:start position:0% +Concept for Global personal + + + align:start position:0% +Concept for Global personal +communication base is a constellation of + + align:start position:0% +communication base is a constellation of + + + align:start position:0% +communication base is a constellation of +lower low earth orbit cellular + + align:start position:0% +lower low earth orbit cellular + + + align:start position:0% +lower low earth orbit cellular +satellites August 18th 1999 9 years + + align:start position:0% +satellites August 18th 1999 9 years + + + align:start position:0% +satellites August 18th 1999 9 years +later last week rum LLC filed bankruptcy + + align:start position:0% +later last week rum LLC filed bankruptcy + + + align:start position:0% +later last week rum LLC filed bankruptcy +court protection lost Investments are + + align:start position:0% +court protection lost Investments are + + + align:start position:0% +court protection lost Investments are +estimated at 5 billion okay so question + + align:start position:0% +estimated at 5 billion okay so question + + + align:start position:0% +estimated at 5 billion okay so question +is why did it happen because the + + align:start position:0% +is why did it happen because the + + + align:start position:0% +is why did it happen because the +technology actually worked quite well it + + align:start position:0% +technology actually worked quite well it + + + align:start position:0% +technology actually worked quite well it +was not a technological failure it was a + + align:start position:0% +was not a technological failure it was a + + + align:start position:0% +was not a technological failure it was a +business failure but I would argue a + + align:start position:0% +business failure but I would argue a + + + align:start position:0% +business failure but I would argue a +systems failure to think about the + + align:start position:0% +systems failure to think about the + + + align:start position:0% +systems failure to think about the +problem differently so the the + + align:start position:0% +problem differently so the the + + + align:start position:0% +problem differently so the the +fundamental challenge is to to properly + + align:start position:0% +fundamental challenge is to to properly + + + align:start position:0% +fundamental challenge is to to properly +size the capacity of a lart system so if + + align:start position:0% +size the capacity of a lart system so if + + + align:start position:0% +size the capacity of a lart system so if +you're designing you know a car factory + + align:start position:0% +you're designing you know a car factory + + + align:start position:0% +you're designing you know a car factory +a new power system a you know and it's + + align:start position:0% +a new power system a you know and it's + + + align:start position:0% +a new power system a you know and it's +for a future uner demand it's very + + align:start position:0% +for a future uner demand it's very + + + align:start position:0% +for a future uner demand it's very +difficult to do this because uncert + + align:start position:0% +difficult to do this because uncert + + + align:start position:0% +difficult to do this because uncert +demand is uncertain so is it better to + + align:start position:0% +demand is uncertain so is it better to + + + align:start position:0% +demand is uncertain so is it better to +oversize the system or are you + + align:start position:0% +oversize the system or are you + + + align:start position:0% +oversize the system or are you +conservative and you make it smaller uh + + align:start position:0% +conservative and you make it smaller uh + + + align:start position:0% +conservative and you make it smaller uh +Market assumptions can change right in + + align:start position:0% +Market assumptions can change right in + + + align:start position:0% +Market assumptions can change right in +those seven to eight years and uh + + align:start position:0% +those seven to eight years and uh + + + align:start position:0% +those seven to eight years and uh +between so essentially the V right + + align:start position:0% +between so essentially the V right + + + align:start position:0% +between so essentially the V right +getting back to the V each of those two + + align:start position:0% +getting back to the V each of those two + + + align:start position:0% +getting back to the V each of those two +systems idium and and global are it took + + align:start position:0% +systems idium and and global are it took + + + align:start position:0% +systems idium and and global are it took +them essentially a decade almost 10 + + align:start position:0% +them essentially a decade almost 10 + + + align:start position:0% +them essentially a decade almost 10 +years right to go across the whole V and + + align:start position:0% +years right to go across the whole V and + + + align:start position:0% +years right to go across the whole V and +when you make you know your requirements + + align:start position:0% +when you make you know your requirements + + + align:start position:0% +when you make you know your requirements +your stakeholders all the stuff in the + + align:start position:0% +your stakeholders all the stuff in the + + + align:start position:0% +your stakeholders all the stuff in the +upper left portion of the V when there's + + align:start position:0% +upper left portion of the V when there's + + + align:start position:0% +upper left portion of the V when there's +there's so many years that elapse + + align:start position:0% +there's so many years that elapse + + + align:start position:0% +there's so many years that elapse +between when you make those assumptions + + align:start position:0% +between when you make those assumptions + + + align:start position:0% +between when you make those assumptions +you write those requirements and when + + align:start position:0% +you write those requirements and when + + + align:start position:0% +you write those requirements and when +you actually go to market a lot of + + align:start position:0% +you actually go to market a lot of + + + align:start position:0% +you actually go to market a lot of +things can change and that's + + align:start position:0% +things can change and that's + + + align:start position:0% +things can change and that's +fundamentally the challenge + + align:start position:0% +fundamentally the challenge + + + align:start position:0% +fundamentally the challenge +here uh just to illustrate this for you + + align:start position:0% +here uh just to illustrate this for you + + + align:start position:0% +here uh just to illustrate this for you +um showing some data + + align:start position:0% +um showing some data + + + align:start position:0% +um showing some data +this is uh cellular this is not + + align:start position:0% +this is uh cellular this is not + + + align:start position:0% +this is uh cellular this is not +space-based this is on the ground + + align:start position:0% +space-based this is on the ground + + + align:start position:0% +space-based this is on the ground +cellular subscribers for mobile phones + + align:start position:0% +cellular subscribers for mobile phones + + + align:start position:0% +cellular subscribers for mobile phones +it it's I know this is hard for your + + align:start position:0% +it it's I know this is hard for your + + + align:start position:0% +it it's I know this is hard for your +generation to sort of understand this + + align:start position:0% +generation to sort of understand this + + + align:start position:0% +generation to sort of understand this +but we actually didn't have mobile + + align:start position:0% +but we actually didn't have mobile + + + align:start position:0% +but we actually didn't have mobile +phones or they were these clunky bricks + + align:start position:0% +phones or they were these clunky bricks + + + align:start position:0% +phones or they were these clunky bricks +you know in your car you know it's it's + + align:start position:0% +you know in your car you know it's it's + + + align:start position:0% +you know in your car you know it's it's +really um remarkable what's happened so + + align:start position:0% +really um remarkable what's happened so + + + align:start position:0% +really um remarkable what's happened so +look at this data in 1991 right which is + + align:start position:0% +look at this data in 1991 right which is + + + align:start position:0% +look at this data in 1991 right which is +when when the system was just being + + align:start position:0% +when when the system was just being + + + align:start position:0% +when when the system was just being +developed there were less than 10 + + align:start position:0% +developed there were less than 10 + + + align:start position:0% +developed there were less than 10 +million mobile phone users in the US it + + align:start position:0% +million mobile phone users in the US it + + + align:start position:0% +million mobile phone users in the US it +just wasn't it was very expensive it was + + align:start position:0% +just wasn't it was very expensive it was + + + align:start position:0% +just wasn't it was very expensive it was +just not not widely uh that technology + + align:start position:0% +just not not widely uh that technology + + + align:start position:0% +just not not widely uh that technology +hadn't been the networks weren't there + + align:start position:0% +hadn't been the networks weren't there + + + align:start position:0% +hadn't been the networks weren't there +you know um so the the the green Bars + + align:start position:0% +you know um so the the the green Bars + + + align:start position:0% +you know um so the the the green Bars +were the forecast that was done in 1991 + + align:start position:0% +were the forecast that was done in 1991 + + + align:start position:0% +were the forecast that was done in 1991 +as to how quickly the mobile user Market + + align:start position:0% +as to how quickly the mobile user Market + + + align:start position:0% +as to how quickly the mobile user Market +would evolve in the US so their + + align:start position:0% +would evolve in the US so their + + + align:start position:0% +would evolve in the US so their +prediction was that by 2000 a decade + + align:start position:0% +prediction was that by 2000 a decade + + + align:start position:0% +prediction was that by 2000 a decade +later there'd be just shy of 40 million + + align:start position:0% +later there'd be just shy of 40 million + + + align:start position:0% +later there'd be just shy of 40 million +users + + align:start position:0% +users + + + align:start position:0% +users +okay now the dark blue bar is the actual + + align:start position:0% +okay now the dark blue bar is the actual + + + align:start position:0% +okay now the dark blue bar is the actual +Evolution so actually by 2000 you know + + align:start position:0% +Evolution so actually by 2000 you know + + + align:start position:0% +Evolution so actually by 2000 you know +the US now has 310 or so million + + align:start position:0% +the US now has 310 or so million + + + align:start position:0% +the US now has 310 or so million +inhabitants um so by 2000 there were 120 + + align:start position:0% +inhabitants um so by 2000 there were 120 + + + align:start position:0% +inhabitants um so by 2000 there were 120 +million users so the forecast that was + + align:start position:0% +million users so the forecast that was + + + align:start position:0% +million users so the forecast that was +done 10 years earlier was off by a + + align:start position:0% +done 10 years earlier was off by a + + + align:start position:0% +done 10 years earlier was off by a +factor of three the ground the + + align:start position:0% +factor of three the ground the + + + align:start position:0% +factor of three the ground the +terrestrial mobile + + align:start position:0% +terrestrial mobile + + + align:start position:0% +terrestrial mobile +networks uh veloped three times faster + + align:start position:0% +networks uh veloped three times faster + + + align:start position:0% +networks uh veloped three times faster +than had been predicted now that's great + + align:start position:0% +than had been predicted now that's great + + + align:start position:0% +than had been predicted now that's great +for the terrestrial people right the + + align:start position:0% +for the terrestrial people right the + + + align:start position:0% +for the terrestrial people right the +AT&T and Comcast not not Comcast + + align:start position:0% +AT&T and Comcast not not Comcast + + + align:start position:0% +AT&T and Comcast not not Comcast +Qualcomm Etc but the problem is of + + align:start position:0% +Qualcomm Etc but the problem is of + + + align:start position:0% +Qualcomm Etc but the problem is of +course that because you know groundbased + + align:start position:0% +course that because you know groundbased + + + align:start position:0% +course that because you know groundbased +Communications was so much easier a lot + + align:start position:0% +Communications was so much easier a lot + + + align:start position:0% +Communications was so much easier a lot +of the market that had been anticipated + + align:start position:0% +of the market that had been anticipated + + + align:start position:0% +of the market that had been anticipated +for the satellite based Communications + + align:start position:0% +for the satellite based Communications + + + align:start position:0% +for the satellite based Communications +was essentially uh eaten Away by uh you + + align:start position:0% +was essentially uh eaten Away by uh you + + + align:start position:0% +was essentially uh eaten Away by uh you +know by this competitor by the + + align:start position:0% +know by this competitor by the + + + align:start position:0% +know by this competitor by the +groundbased competitor go ahead may I + + align:start position:0% +groundbased competitor go ahead may I + + + align:start position:0% +groundbased competitor go ahead may I +intervene here just so that uh yeah okay + + align:start position:0% +intervene here just so that uh yeah okay + + + align:start position:0% +intervene here just so that uh yeah okay +uh can you still hear it are you still + + align:start position:0% +uh can you still hear it are you still + + + align:start position:0% +uh can you still hear it are you still +with + + align:start position:0% +with + + + align:start position:0% +with +us yes yes you are okay vulker wants to + + align:start position:0% +us yes yes you are okay vulker wants to + + + align:start position:0% +us yes yes you are okay vulker wants to +say + + align:start position:0% + + + + align:start position:0% + +something actually the figures that you + + align:start position:0% +something actually the figures that you + + + align:start position:0% +something actually the figures that you +showed o about American Statics and for + + align:start position:0% +showed o about American Statics and for + + + align:start position:0% +showed o about American Statics and for +once Americans did not look over the + + align:start position:0% +once Americans did not look over the + + + align:start position:0% +once Americans did not look over the +pond because at that time in Europe the + + align:start position:0% +pond because at that time in Europe the + + + align:start position:0% +pond because at that time in Europe the +GSM systems came really strong and very + + align:start position:0% +GSM systems came really strong and very + + + align:start position:0% +GSM systems came really strong and very +quickly in the early '90s you could + + align:start position:0% +quickly in the early '90s you could + + + align:start position:0% +quickly in the early '90s you could +already have your sim card and your + + align:start position:0% +already have your sim card and your + + + align:start position:0% +already have your sim card and your +telephone yourself and back in America + + align:start position:0% +telephone yourself and back in America + + + align:start position:0% +telephone yourself and back in America +then you could only buy the telephone + + align:start position:0% +then you could only buy the telephone + + + align:start position:0% +then you could only buy the telephone +with all the SIM card in you had to buy + + align:start position:0% +with all the SIM card in you had to buy + + + align:start position:0% +with all the SIM card in you had to buy +the whole system and so as the system + + align:start position:0% +the whole system and so as the system + + + align:start position:0% +the whole system and so as the system +was controlled by the large companies + + align:start position:0% +was controlled by the large companies + + + align:start position:0% +was controlled by the large companies +and not by the users the large companies + + align:start position:0% +and not by the users the large companies + + + align:start position:0% +and not by the users the large companies +Motorola thought that they could impose + + align:start position:0% +Motorola thought that they could impose + + + align:start position:0% +Motorola thought that they could impose +their satellite system on the market and + + align:start position:0% +their satellite system on the market and + + + align:start position:0% +their satellite system on the market and +in this case contrary to the uh uh video + + align:start position:0% +in this case contrary to the uh uh video + + + align:start position:0% +in this case contrary to the uh uh video +recorders Hi-Fi systems earlier uh + + align:start position:0% +recorders Hi-Fi systems earlier uh + + + align:start position:0% +recorders Hi-Fi systems earlier uh +Europe went much f faster in America and + + align:start position:0% +Europe went much f faster in America and + + + align:start position:0% +Europe went much f faster in America and +actually the European GSM Market cell + + align:start position:0% +actually the European GSM Market cell + + + align:start position:0% +actually the European GSM Market cell +phones as you know them went much + + align:start position:0% +phones as you know them went much + + + align:start position:0% +phones as you know them went much +quicker and then Nokia which is actually + + align:start position:0% +quicker and then Nokia which is actually + + + align:start position:0% +quicker and then Nokia which is actually +European overtook and it took probably + + align:start position:0% +European overtook and it took probably + + + align:start position:0% +European overtook and it took probably +the next decade for Americans to catch + + align:start position:0% +the next decade for Americans to catch + + + align:start position:0% +the next decade for Americans to catch +up so finally here this was then a + + align:start position:0% +up so finally here this was then a + + + align:start position:0% +up so finally here this was then a +combination that people had a product + + align:start position:0% +combination that people had a product + + + align:start position:0% +combination that people had a product +and they just didn't get in the US so + + align:start position:0% +and they just didn't get in the US so + + + align:start position:0% +and they just didn't get in the US so +they were limited to their own market + + align:start position:0% +they were limited to their own market + + + align:start position:0% +they were limited to their own market +and not to sell their products to the + + align:start position:0% +and not to sell their products to the + + + align:start position:0% +and not to sell their products to the +rest of the world as they had done in + + align:start position:0% +rest of the world as they had done in + + + align:start position:0% +rest of the world as they had done in +the past yeah good point so and in in + + align:start position:0% +the past yeah good point so and in in + + + align:start position:0% +the past yeah good point so and in in +fact you know one of the one of the + + align:start position:0% +fact you know one of the one of the + + + align:start position:0% +fact you know one of the one of the +things that um + + align:start position:0% +things that um + + + align:start position:0% +things that um +that um I think both Global star and + + align:start position:0% +that um I think both Global star and + + + align:start position:0% +that um I think both Global star and +aridium had to do and this was a very + + align:start position:0% +aridium had to do and this was a very + + + align:start position:0% +aridium had to do and this was a very +late decision like just in the last + + align:start position:0% +late decision like just in the last + + + align:start position:0% +late decision like just in the last +couple years here before launch 97 98 is + + align:start position:0% +couple years here before launch 97 98 is + + + align:start position:0% +couple years here before launch 97 98 is +to make their their handset dual use + + align:start position:0% +to make their their handset dual use + + + align:start position:0% +to make their their handset dual use +right that if you were in an in an area + + align:start position:0% +right that if you were in an in an area + + + align:start position:0% +right that if you were in an in an area +where there was a cellular network the + + align:start position:0% +where there was a cellular network the + + + align:start position:0% +where there was a cellular network the +phone would switch to that because that + + align:start position:0% +phone would switch to that because that + + + align:start position:0% +phone would switch to that because that +would be cheaper and if if you didn't + + align:start position:0% +would be cheaper and if if you didn't + + + align:start position:0% +would be cheaper and if if you didn't +have cell your network access it would + + align:start position:0% +have cell your network access it would + + + align:start position:0% +have cell your network access it would +automatically try to communicate to the + + align:start position:0% +automatically try to communicate to the + + + align:start position:0% +automatically try to communicate to the +satellite so there was a lot of there + + align:start position:0% +satellite so there was a lot of there + + + align:start position:0% +satellite so there was a lot of there +were a lot lot of uh issues that came up + + align:start position:0% +were a lot lot of uh issues that came up + + + align:start position:0% +were a lot lot of uh issues that came up +by essentially the markets I think in in + + align:start position:0% +by essentially the markets I think in in + + + align:start position:0% +by essentially the markets I think in in +in in Europe your point wker about the + + align:start position:0% +in in Europe your point wker about the + + + align:start position:0% +in in Europe your point wker about the +GSM and in the US just developing quite + + align:start position:0% +GSM and in the US just developing quite + + + align:start position:0% +GSM and in the US just developing quite +differently than had been + + align:start position:0% +differently than had been + + + align:start position:0% +differently than had been +anticipated okay so I want to give you a + + align:start position:0% +anticipated okay so I want to give you a + + + align:start position:0% +anticipated okay so I want to give you a +little bit about sort of Economics of in + + align:start position:0% +little bit about sort of Economics of in + + + align:start position:0% +little bit about sort of Economics of in +the end a lot of this is driven by uh by + + align:start position:0% +the end a lot of this is driven by uh by + + + align:start position:0% +the end a lot of this is driven by uh by +money by economics and so this is you + + align:start position:0% +money by economics and so this is you + + + align:start position:0% +money by economics and so this is you +know satellite economics + + align:start position:0% +know satellite economics + + + align:start position:0% +know satellite economics +101 um the key question here is how much + + align:start position:0% +101 um the key question here is how much + + + align:start position:0% +101 um the key question here is how much +how expensive is it what's what's the + + align:start position:0% +how expensive is it what's what's the + + + align:start position:0% +how expensive is it what's what's the +cost and then what is the price that you + + align:start position:0% +cost and then what is the price that you + + + align:start position:0% +cost and then what is the price that you +can charge for one minute of service + + align:start position:0% +can charge for one minute of service + + + align:start position:0% +can charge for one minute of service +right one minute of one unit of + + align:start position:0% +right one minute of one unit of + + + align:start position:0% +right one minute of one unit of +service and so look at this equation + + align:start position:0% +service and so look at this equation + + + align:start position:0% +service and so look at this equation +here here this is cpf stands for cost + + align:start position:0% +here here this is cpf stands for cost + + + align:start position:0% +here here this is cpf stands for cost +per function um and so in the numerator + + align:start position:0% +per function um and so in the numerator + + + align:start position:0% +per function um and so in the numerator +we have the life cycle cost which is + + align:start position:0% +we have the life cycle cost which is + + + align:start position:0% +we have the life cycle cost which is +your initial + + align:start position:0% +your initial + + + align:start position:0% +your initial +investment uh and then we uh we + + align:start position:0% +investment uh and then we uh we + + + align:start position:0% +investment uh and then we uh we +essentially capitalize that with some + + align:start position:0% +essentially capitalize that with some + + + align:start position:0% +essentially capitalize that with some +interest rate K plus then for each year + + align:start position:0% +interest rate K plus then for each year + + + align:start position:0% +interest rate K plus then for each year +of of operation you have the operational + + align:start position:0% +of of operation you have the operational + + + align:start position:0% +of of operation you have the operational +cost for that year that you have to add + + align:start position:0% +cost for that year that you have to add + + + align:start position:0% +cost for that year that you have to add +so that's your initial you know that's + + align:start position:0% +so that's your initial you know that's + + + align:start position:0% +so that's your initial you know that's +your development cost your manufacturing + + align:start position:0% +your development cost your manufacturing + + + align:start position:0% +your development cost your manufacturing +cost for the satellites including the + + align:start position:0% +cost for the satellites including the + + + align:start position:0% +cost for the satellites including the +launch cost and then the Ops cost would + + align:start position:0% +launch cost and then the Ops cost would + + + align:start position:0% +launch cost and then the Ops cost would +be operating your ground stations your + + align:start position:0% +be operating your ground stations your + + + align:start position:0% +be operating your ground stations your +networks any replenishment cost they + + align:start position:0% +networks any replenishment cost they + + + align:start position:0% +networks any replenishment cost they +would be in your Ops cost and then you + + align:start position:0% +would be in your Ops cost and then you + + + align:start position:0% +would be in your Ops cost and then you +divide this by what's called here the + + align:start position:0% +divide this by what's called here the + + + align:start position:0% +divide this by what's called here the +number of billable minutes that doesn't + + align:start position:0% +number of billable minutes that doesn't + + + align:start position:0% +number of billable minutes that doesn't +mean you're actually going to build + + align:start position:0% +mean you're actually going to build + + + align:start position:0% +mean you're actually going to build +people it means just the are potentially + + align:start position:0% +people it means just the are potentially + + + align:start position:0% +people it means just the are potentially +billable minutes so that's the capacity + + align:start position:0% +billable minutes so that's the capacity + + + align:start position:0% +billable minutes so that's the capacity +of the system C Subs times you know 3 + + align:start position:0% +of the system C Subs times you know 3 + + + align:start position:0% +of the system C Subs times you know 3 +365 days * 24 hours * 60 Minutes times + + align:start position:0% +365 days * 24 hours * 60 Minutes times + + + align:start position:0% +365 days * 24 hours * 60 Minutes times +uh what's the load Factor so the load + + align:start position:0% +uh what's the load Factor so the load + + + align:start position:0% +uh what's the load Factor so the load +factor is essentially the the capacity + + align:start position:0% +factor is essentially the the capacity + + + align:start position:0% +factor is essentially the the capacity +utilization of the system that you + + align:start position:0% +utilization of the system that you + + + align:start position:0% +utilization of the system that you +anticipate okay so that's that's the + + align:start position:0% +anticipate okay so that's that's the + + + align:start position:0% +anticipate okay so that's that's the +basic equation for calculating uh cpf + + align:start position:0% +basic equation for calculating uh cpf + + + align:start position:0% +basic equation for calculating uh cpf +cost per function plug in some numbers + + align:start position:0% +cost per function plug in some numbers + + + align:start position:0% +cost per function plug in some numbers +here these are the numbers that had been + + align:start position:0% +here these are the numbers that had been + + + align:start position:0% +here these are the numbers that had been +assumed you know a $3 billion investment + + align:start position:0% +assumed you know a $3 billion investment + + + align:start position:0% +assumed you know a $3 billion investment +5% interest rate $300 million per year + + align:start position:0% +5% interest rate $300 million per year + + + align:start position:0% +5% interest rate $300 million per year +of Ops cost 15year life cycle this is + + align:start position:0% +of Ops cost 15year life cycle this is + + + align:start position:0% +of Ops cost 15year life cycle this is +the capital T over 15 years 100,000 + + align:start position:0% +the capital T over 15 years 100,000 + + + align:start position:0% +the capital T over 15 years 100,000 +channels that's your capacity number of + + align:start position:0% +channels that's your capacity number of + + + align:start position:0% +channels that's your capacity number of +users in this case uh so the the the + + align:start position:0% +users in this case uh so the the the + + + align:start position:0% +users in this case uh so the the the +load factor is simply the number of + + align:start position:0% +load factor is simply the number of + + + align:start position:0% +load factor is simply the number of +users times the average activity per + + align:start position:0% +users times the average activity per + + + align:start position:0% +users times the average activity per +user in this case assumed to be 100 uh + + align:start position:0% +user in this case assumed to be 100 uh + + + align:start position:0% +user in this case assumed to be 100 uh +1,00 minutes per year but 100 minutes + + align:start position:0% +1,00 minutes per year but 100 minutes + + + align:start position:0% +1,00 minutes per year but 100 minutes +per month okay uh so that gets you um + + align:start position:0% +per month okay uh so that gets you um + + + align:start position:0% +per month okay uh so that gets you um +that gets you a cpf of 20 cents per + + align:start position:0% +that gets you a cpf of 20 cents per + + + align:start position:0% +that gets you a cpf of 20 cents per +minute and based on that you can you can + + align:start position:0% +minute and based on that you can you can + + + align:start position:0% +minute and based on that you can you can +uh you know the business case was made + + align:start position:0% +uh you know the business case was made + + + align:start position:0% +uh you know the business case was made +made based on these kind of numbers um + + align:start position:0% +made based on these kind of numbers um + + + align:start position:0% +made based on these kind of numbers um +and and so 3 million users these are 3 + + align:start position:0% +and and so 3 million users these are 3 + + + align:start position:0% +and and so 3 million users these are 3 +million subscribers right not 3 million + + align:start position:0% +million subscribers right not 3 million + + + align:start position:0% +million subscribers right not 3 million +users at the same time that number would + + align:start position:0% +users at the same time that number would + + + align:start position:0% +users at the same time that number would +be much smaller that number can't be + + align:start position:0% +be much smaller that number can't be + + + align:start position:0% +be much smaller that number can't be +bigger than 100,000 because that's your + + align:start position:0% +bigger than 100,000 because that's your + + + align:start position:0% +bigger than 100,000 because that's your +capacity so for example if you if you + + align:start position:0% +capacity so for example if you if you + + + align:start position:0% +capacity so for example if you if you +run if if you run a fitness club right + + align:start position:0% +run if if you run a fitness club right + + + align:start position:0% +run if if you run a fitness club right +uh at any given time in your Fitness + + align:start position:0% +uh at any given time in your Fitness + + + align:start position:0% +uh at any given time in your Fitness +club you can maybe have I don't know 50 + + align:start position:0% +club you can maybe have I don't know 50 + + + align:start position:0% +club you can maybe have I don't know 50 +or 100 people actually working out right + + align:start position:0% +or 100 people actually working out right + + + align:start position:0% +or 100 people actually working out right +but your number of customers or + + align:start position:0% +but your number of customers or + + + align:start position:0% +but your number of customers or +subscribers should be you know a th000 + + align:start position:0% +subscribers should be you know a th000 + + + align:start position:0% +subscribers should be you know a th000 +or 2,000 and if they all show up at the + + align:start position:0% +or 2,000 and if they all show up at the + + + align:start position:0% +or 2,000 and if they all show up at the +same time you're in big trouble right so + + align:start position:0% +same time you're in big trouble right so + + + align:start position:0% +same time you're in big trouble right so +that's the big that's the difference + + align:start position:0% +that's the big that's the difference + + + align:start position:0% +that's the big that's the difference +between number of users or number of + + align:start position:0% +between number of users or number of + + + align:start position:0% +between number of users or number of +subscribers and number of active users + + align:start position:0% +subscribers and number of active users + + + align:start position:0% +subscribers and number of active users +at any given time that's that's a big + + align:start position:0% +at any given time that's that's a big + + + align:start position:0% +at any given time that's that's a big +part of um man in these kind of systems + + align:start position:0% +part of um man in these kind of systems + + + align:start position:0% +part of um man in these kind of systems +however uh what actually happened is the + + align:start position:0% +however uh what actually happened is the + + + align:start position:0% +however uh what actually happened is the +number of actual users grew much much + + align:start position:0% +number of actual users grew much much + + + align:start position:0% +number of actual users grew much much +slower so if you plug in some different + + align:start position:0% +slower so if you plug in some different + + + align:start position:0% +slower so if you plug in some different +num let's keep all the numbers the same + + align:start position:0% +num let's keep all the numbers the same + + + align:start position:0% +num let's keep all the numbers the same +except for the subscriber base the + + align:start position:0% +except for the subscriber base the + + + align:start position:0% +except for the subscriber base the +number of users in this case we're going + + align:start position:0% +number of users in this case we're going + + + align:start position:0% +number of users in this case we're going +to assume 50,000 users instead of the 3 + + align:start position:0% +to assume 50,000 users instead of the 3 + + + align:start position:0% +to assume 50,000 users instead of the 3 +million this is closer to what they had + + align:start position:0% +million this is closer to what they had + + + align:start position:0% +million this is closer to what they had +after you know about a year of operation + + align:start position:0% +after you know about a year of operation + + + align:start position:0% +after you know about a year of operation +now your cpf goes to $12 per minute + + align:start position:0% +now your cpf goes to $12 per minute + + + align:start position:0% +now your cpf goes to $12 per minute +which is non-competitive is right except + + align:start position:0% +which is non-competitive is right except + + + align:start position:0% +which is non-competitive is right except +for some extremely you know like + + align:start position:0% +for some extremely you know like + + + align:start position:0% +for some extremely you know like +military applications or you know making + + align:start position:0% +military applications or you know making + + + align:start position:0% +military applications or you know making +some emergency phone calls on an oil rig + + align:start position:0% +some emergency phone calls on an oil rig + + + align:start position:0% +some emergency phone calls on an oil rig +you know on the ocean you know most + + align:start position:0% +you know on the ocean you know most + + + align:start position:0% +you know on the ocean you know most +people at the time now and at the time + + align:start position:0% +people at the time now and at the time + + + align:start position:0% +people at the time now and at the time +would never pay this uh uh for for one + + align:start position:0% +would never pay this uh uh for for one + + + align:start position:0% +would never pay this uh uh for for one +minute of + + align:start position:0% +minute of + + + align:start position:0% +minute of +service and so um that was the + + align:start position:0% +service and so um that was the + + + align:start position:0% +service and so um that was the +fundamental problem is that the user + + align:start position:0% +fundamental problem is that the user + + + align:start position:0% +fundamental problem is that the user +base did not materialize as fast as + + align:start position:0% +base did not materialize as fast as + + + align:start position:0% +base did not materialize as fast as +planned therefore this cost per function + + align:start position:0% +planned therefore this cost per function + + + align:start position:0% +planned therefore this cost per function +was way higher and they did charge you + + align:start position:0% +was way higher and they did charge you + + + align:start position:0% +was way higher and they did charge you +know $3 to5 per minute of usage of the + + align:start position:0% +know $3 to5 per minute of usage of the + + + align:start position:0% +know $3 to5 per minute of usage of the +system which uh you know as you try to + + align:start position:0% +system which uh you know as you try to + + + align:start position:0% +system which uh you know as you try to +squeeze your existing users more uh + + align:start position:0% +squeeze your existing users more uh + + + align:start position:0% +squeeze your existing users more uh +you're not going to get the the ramp up + + align:start position:0% +you're not going to get the the ramp up + + + align:start position:0% +you're not going to get the the ramp up +and the scale up in the system that you + + align:start position:0% +and the scale up in the system that you + + + align:start position:0% +and the scale up in the system that you +need that was the fundamental problem + + align:start position:0% +need that was the fundamental problem + + + align:start position:0% +need that was the fundamental problem +with with the economics of these + + align:start position:0% +with with the economics of these + + + align:start position:0% +with with the economics of these +systems so let me talk a little bit + + align:start position:0% +systems so let me talk a little bit + + + align:start position:0% +systems so let me talk a little bit +about you know the design decisions the + + align:start position:0% +about you know the design decisions the + + + align:start position:0% +about you know the design decisions the +conceptual design uh of what this design + + align:start position:0% +conceptual design uh of what this design + + + align:start position:0% +conceptual design uh of what this design +space looks like so fundamental um oh + + align:start position:0% +space looks like so fundamental um oh + + + align:start position:0% +space looks like so fundamental um oh +the other thing I should mention to you + + align:start position:0% +the other thing I should mention to you + + + align:start position:0% +the other thing I should mention to you +what was interesting is both after the + + align:start position:0% +what was interesting is both after the + + + align:start position:0% +what was interesting is both after the +bankruptcy both of radium and Global + + align:start position:0% +bankruptcy both of radium and Global + + + align:start position:0% +bankruptcy both of radium and Global +Star both of the chief Engineers for + + align:start position:0% +Star both of the chief Engineers for + + + align:start position:0% +Star both of the chief Engineers for +both of these systems uh took Refuge at + + align:start position:0% +both of these systems uh took Refuge at + + + align:start position:0% +both of these systems uh took Refuge at +MIT essentially they came like uh Joel + + align:start position:0% +MIT essentially they came like uh Joel + + + align:start position:0% +MIT essentially they came like uh Joel +shandal who was the uh chief engineer + + align:start position:0% +shandal who was the uh chief engineer + + + align:start position:0% +shandal who was the uh chief engineer +for Global star great guy both very + + align:start position:0% +for Global star great guy both very + + + align:start position:0% +for Global star great guy both very +competent people uh came to MIT still + + align:start position:0% +competent people uh came to MIT still + + + align:start position:0% +competent people uh came to MIT still +there he's still a professor there and + + align:start position:0% +there he's still a professor there and + + + align:start position:0% +there he's still a professor there and +then Ray Leopold was one of the three + + align:start position:0% +then Ray Leopold was one of the three + + + align:start position:0% +then Ray Leopold was one of the three +architects for idium also came to MIT + + align:start position:0% +architects for idium also came to MIT + + + align:start position:0% +architects for idium also came to MIT +during this time so I had extensive + + align:start position:0% +during this time so I had extensive + + + align:start position:0% +during this time so I had extensive +discussions with them and what you see + + align:start position:0% +discussions with them and what you see + + + align:start position:0% +discussions with them and what you see +here on slide 25 is one result of those + + align:start position:0% +here on slide 25 is one result of those + + + align:start position:0% +here on slide 25 is one result of those +discussions which is you know the the + + align:start position:0% +discussions which is you know the the + + + align:start position:0% +discussions which is you know the the +key design decisions that they had to + + align:start position:0% +key design decisions that they had to + + + align:start position:0% +key design decisions that they had to +make uh fundamentally there's uh you + + align:start position:0% +make uh fundamentally there's uh you + + + align:start position:0% +make uh fundamentally there's uh you +won't be surprised to see this this is + + align:start position:0% +won't be surprised to see this this is + + + align:start position:0% +won't be surprised to see this this is +the magic number seven right seven key + + align:start position:0% +the magic number seven right seven key + + + align:start position:0% +the magic number seven right seven key +design decisions when you design a + + align:start position:0% +design decisions when you design a + + + align:start position:0% +design decisions when you design a +satellite constellation for + + align:start position:0% +satellite constellation for + + + align:start position:0% +satellite constellation for +communication purposes constellation + + align:start position:0% +communication purposes constellation + + + align:start position:0% +communication purposes constellation +type polar or Walker orbital altitude + + align:start position:0% +type polar or Walker orbital altitude + + + align:start position:0% +type polar or Walker orbital altitude +minimum elevation angle above the + + align:start position:0% +minimum elevation angle above the + + + align:start position:0% +minimum elevation angle above the +Horizon that you can + + align:start position:0% +Horizon that you can + + + align:start position:0% +Horizon that you can +communicate satellite transmit power the + + align:start position:0% +communicate satellite transmit power the + + + align:start position:0% +communicate satellite transmit power the +size of your primary antenna your + + align:start position:0% +size of your primary antenna your + + + align:start position:0% +size of your primary antenna your +multiax scheme so this is time division + + align:start position:0% +multiax scheme so this is time division + + + align:start position:0% +multiax scheme so this is time division +or uh code Division multiplexing and + + align:start position:0% +or uh code Division multiplexing and + + + align:start position:0% +or uh code Division multiplexing and +then the last one is about the network + + align:start position:0% +then the last one is about the network + + + align:start position:0% +then the last one is about the network +architecture do you have inters + + align:start position:0% +architecture do you have inters + + + align:start position:0% +architecture do you have inters +satellite links yes or no inters + + align:start position:0% +satellite links yes or no inters + + + align:start position:0% +satellite links yes or no inters +satellite links means satellites can + + align:start position:0% +satellite links means satellites can + + + align:start position:0% +satellite links means satellites can +talk to each other + + align:start position:0% +talk to each other + + + align:start position:0% +talk to each other +uh and iridium chose that um Global star + + align:start position:0% +uh and iridium chose that um Global star + + + align:start position:0% +uh and iridium chose that um Global star +did not so in global star the global + + align:start position:0% +did not so in global star the global + + + align:start position:0% +did not so in global star the global +star satellites cannot talk to each + + align:start position:0% +star satellites cannot talk to each + + + align:start position:0% +star satellites cannot talk to each +other directly in space they can only + + align:start position:0% +other directly in space they can only + + + align:start position:0% +other directly in space they can only +talk it's a bent pipe system through a + + align:start position:0% +talk it's a bent pipe system through a + + + align:start position:0% +talk it's a bent pipe system through a +ground + + align:start position:0% +ground + + + align:start position:0% +ground +station okay so if you this is like the + + align:start position:0% +station okay so if you this is like the + + + align:start position:0% +station okay so if you this is like the +morphological Matrix that you learned + + align:start position:0% +morphological Matrix that you learned + + + align:start position:0% +morphological Matrix that you learned +about you just pick uh design decisions + + align:start position:0% +about you just pick uh design decisions + + + align:start position:0% +about you just pick uh design decisions +in this morphological Matrix and you + + align:start position:0% +in this morphological Matrix and you + + + align:start position:0% +in this morphological Matrix and you +come up with an architecture in fact a + + align:start position:0% +come up with an architecture in fact a + + + align:start position:0% +come up with an architecture in fact a +full factorial search of the space base + + align:start position:0% +full factorial search of the space base + + + align:start position:0% +full factorial search of the space base +would reveal 1440 different satellite + + align:start position:0% +would reveal 1440 different satellite + + + align:start position:0% +would reveal 1440 different satellite +architectures um so what's your that's + + align:start position:0% +architectures um so what's your that's + + + align:start position:0% +architectures um so what's your that's +on the input side what's the output + + align:start position:0% +on the input side what's the output + + + align:start position:0% +on the input side what's the output +Vector what do you care about in terms + + align:start position:0% +Vector what do you care about in terms + + + align:start position:0% +Vector what do you care about in terms +of output of the system well first of + + align:start position:0% +of output of the system well first of + + + align:start position:0% +of output of the system well first of +all performance um so the performance of + + align:start position:0% +all performance um so the performance of + + + align:start position:0% +all performance um so the performance of +this is for voice Communications it in a + + align:start position:0% +this is for voice Communications it in a + + + align:start position:0% +this is for voice Communications it in a +sense it applies to data Communications + + align:start position:0% +sense it applies to data Communications + + + align:start position:0% +sense it applies to data Communications +as well is your data rate per channel + + align:start position:0% +as well is your data rate per channel + + + align:start position:0% +as well is your data rate per channel +right 4.8 uh kbps your bit error rate + + align:start position:0% +right 4.8 uh kbps your bit error rate + + + align:start position:0% +right 4.8 uh kbps your bit error rate +like what's the average number of bits + + align:start position:0% +like what's the average number of bits + + + align:start position:0% +like what's the average number of bits +that are wrong 10 Theus 3 that's + + align:start position:0% +that are wrong 10 Theus 3 that's + + + align:start position:0% +that are wrong 10 Theus 3 that's +actually a pretty uh not a very that's + + align:start position:0% +actually a pretty uh not a very that's + + + align:start position:0% +actually a pretty uh not a very that's +not a very stringent requirement and the + + align:start position:0% +not a very stringent requirement and the + + + align:start position:0% +not a very stringent requirement and the +reason is you're just this is for voice + + align:start position:0% +reason is you're just this is for voice + + + align:start position:0% +reason is you're just this is for voice +communication this is not for sending + + align:start position:0% +communication this is not for sending + + + align:start position:0% +communication this is not for sending +you know commands to a spacecraft going + + align:start position:0% +you know commands to a spacecraft going + + + align:start position:0% +you know commands to a spacecraft going +to Mars if you send commands it would + + align:start position:0% +to Mars if you send commands it would + + + align:start position:0% +to Mars if you send commands it would +have to be you know 10 theus1 or 10- 9 + + align:start position:0% +have to be you know 10 theus1 or 10- 9 + + + align:start position:0% +have to be you know 10 theus1 or 10- 9 +much much better bit error rate but this + + align:start position:0% +much much better bit error rate but this + + + align:start position:0% +much much better bit error rate but this +is okay for for voice and then the link + + align:start position:0% +is okay for for voice and then the link + + + align:start position:0% +is okay for for voice and then the link +fading margin 16 uh DB this is the + + align:start position:0% +fading margin 16 uh DB this is the + + + align:start position:0% +fading margin 16 uh DB this is the +strength of the signal uh which will + + align:start position:0% +strength of the signal uh which will + + + align:start position:0% +strength of the signal uh which will +which will dictate whether or not you + + align:start position:0% +which will dictate whether or not you + + + align:start position:0% +which will dictate whether or not you +can use the phone under trees or in + + align:start position:0% +can use the phone under trees or in + + + align:start position:0% +can use the phone under trees or in +buildings uh so you want this number to + + align:start position:0% +buildings uh so you want this number to + + + align:start position:0% +buildings uh so you want this number to +be higher but the higher it is you know + + align:start position:0% +be higher but the higher it is you know + + + align:start position:0% +be higher but the higher it is you know +given the power you have on the + + align:start position:0% +given the power you have on the + + + align:start position:0% +given the power you have on the +satellites the fewer channels you have + + align:start position:0% +satellites the fewer channels you have + + + align:start position:0% +satellites the fewer channels you have +so there's tradeoffs so what was done + + align:start position:0% +so there's tradeoffs so what was done + + + align:start position:0% +so there's tradeoffs so what was done +here is to keep the performance fixed + + align:start position:0% +here is to keep the performance fixed + + + align:start position:0% +here is to keep the performance fixed +and so that you can compare + + align:start position:0% +and so that you can compare + + + align:start position:0% +and so that you can compare +architectures you know compare apples to + + align:start position:0% +architectures you know compare apples to + + + align:start position:0% +architectures you know compare apples to +apples then we have capacity which is + + align:start position:0% +apples then we have capacity which is + + + align:start position:0% +apples then we have capacity which is +the number of simultaneous uh duplex + + align:start position:0% +the number of simultaneous uh duplex + + + align:start position:0% +the number of simultaneous uh duplex +channels and then finally the life cycle + + align:start position:0% +channels and then finally the life cycle + + + align:start position:0% +channels and then finally the life cycle +cost of the system which includes + + align:start position:0% +cost of the system which includes + + + align:start position:0% +cost of the system which includes +research development test and evaluation + + align:start position:0% +research development test and evaluation + + + align:start position:0% +research development test and evaluation +satellite construction and tests launch + + align:start position:0% +satellite construction and tests launch + + + align:start position:0% +satellite construction and tests launch +and orbital insertion and then the + + align:start position:0% +and orbital insertion and then the + + + align:start position:0% +and orbital insertion and then the +operations and replenishment so if a + + align:start position:0% +operations and replenishment so if a + + + align:start position:0% +operations and replenishment so if a +satellite fails in orbit either you have + + align:start position:0% +satellite fails in orbit either you have + + + align:start position:0% +satellite fails in orbit either you have +to already have prepositioned the spare + + align:start position:0% +to already have prepositioned the spare + + + align:start position:0% +to already have prepositioned the spare +or you're going to launch you're going + + align:start position:0% +or you're going to launch you're going + + + align:start position:0% +or you're going to launch you're going +to launch a replacement and this + + align:start position:0% +to launch a replacement and this + + + align:start position:0% +to launch a replacement and this +actually happen uh in both cases for + + align:start position:0% +actually happen uh in both cases for + + + align:start position:0% +actually happen uh in both cases for +both + + align:start position:0% +both + + + align:start position:0% +both +constellations so um + + align:start position:0% +constellations so um + + + align:start position:0% +constellations so um +in order to then you know connect the + + align:start position:0% +in order to then you know connect the + + + align:start position:0% +in order to then you know connect the +input to the output you need to build a + + align:start position:0% +input to the output you need to build a + + + align:start position:0% +input to the output you need to build a +simulator or a model of the system and + + align:start position:0% +simulator or a model of the system and + + + align:start position:0% +simulator or a model of the system and +this is a high level view of what that + + align:start position:0% +this is a high level view of what that + + + align:start position:0% +this is a high level view of what that +model looks like so we take our input + + align:start position:0% +model looks like so we take our input + + + align:start position:0% +model looks like so we take our input +our design decisions and certain + + align:start position:0% +our design decisions and certain + + + align:start position:0% +our design decisions and certain +Constance that we assume a constant + + align:start position:0% +Constance that we assume a constant + + + align:start position:0% +Constance that we assume a constant +vector and Cascade this information you + + align:start position:0% +vector and Cascade this information you + + + align:start position:0% +vector and Cascade this information you +know for the constellation module takes + + align:start position:0% +know for the constellation module takes + + + align:start position:0% +know for the constellation module takes +the altitude and the minimum elevation + + align:start position:0% +the altitude and the minimum elevation + + + align:start position:0% +the altitude and the minimum elevation +angle and produces uh T is the number of + + align:start position:0% +angle and produces uh T is the number of + + + align:start position:0% +angle and produces uh T is the number of +satellites and ke is the number of + + align:start position:0% +satellites and ke is the number of + + + align:start position:0% +satellites and ke is the number of +orbital planes so this is sort of + + align:start position:0% +orbital planes so this is sort of + + + align:start position:0% +orbital planes so this is sort of +orbital Dynamics the spacecraft module + + align:start position:0% +orbital Dynamics the spacecraft module + + + align:start position:0% +orbital Dynamics the spacecraft module +calculates the satellite Mass um the + + align:start position:0% +calculates the satellite Mass um the + + + align:start position:0% +calculates the satellite Mass um the +satellite Network um you know builds + + align:start position:0% +satellite Network um you know builds + + + align:start position:0% +satellite Network um you know builds +essentially the communication + + align:start position:0% +essentially the communication + + + align:start position:0% +essentially the communication +communication Pathways the link budget + + align:start position:0% +communication Pathways the link budget + + + align:start position:0% +communication Pathways the link budget +will calculate the capacity of the + + align:start position:0% +will calculate the capacity of the + + + align:start position:0% +will calculate the capacity of the +system you know given given those + + align:start position:0% +system you know given given those + + + align:start position:0% +system you know given given those +performance constraints the launch + + align:start position:0% +performance constraints the launch + + + align:start position:0% +performance constraints the launch +module will determine uh how many + + align:start position:0% +module will determine uh how many + + + align:start position:0% +module will determine uh how many +launches do you need from where and then + + align:start position:0% +launches do you need from where and then + + + align:start position:0% +launches do you need from where and then +the cost module basically calculates the + + align:start position:0% +the cost module basically calculates the + + + align:start position:0% +the cost module basically calculates the +total cost of the system the life cycle + + align:start position:0% +total cost of the system the life cycle + + + align:start position:0% +total cost of the system the life cycle +cost and finally you get essentially a + + align:start position:0% +cost and finally you get essentially a + + + align:start position:0% +cost and finally you get essentially a +tradeoff of life cycle cost versus + + align:start position:0% +tradeoff of life cycle cost versus + + + align:start position:0% +tradeoff of life cycle cost versus +capacity of the + + align:start position:0% +capacity of the + + + align:start position:0% +capacity of the +system um let me just show you some you + + align:start position:0% +system um let me just show you some you + + + align:start position:0% +system um let me just show you some you +know you say well that's tying together + + align:start position:0% +know you say well that's tying together + + + align:start position:0% +know you say well that's tying together +a lot of information into a + + align:start position:0% +a lot of information into a + + + align:start position:0% +a lot of information into a +multidisciplinary model so what kind of + + align:start position:0% +multidisciplinary model so what kind of + + + align:start position:0% +multidisciplinary model so what kind of +information do you have you have a mix + + align:start position:0% +information do you have you have a mix + + + align:start position:0% +information do you have you have a mix +really of physics-based models so this + + align:start position:0% +really of physics-based models so this + + + align:start position:0% +really of physics-based models so this +is a very well-known equation the EB + + align:start position:0% +is a very well-known equation the EB + + + align:start position:0% +is a very well-known equation the EB +knot this is the energy bit over noise + + align:start position:0% +knot this is the energy bit over noise + + + align:start position:0% +knot this is the energy bit over noise +ratio this is a closed form you know + + align:start position:0% +ratio this is a closed form you know + + + align:start position:0% +ratio this is a closed form you know +physics based equation that tells you + + align:start position:0% +physics based equation that tells you + + + align:start position:0% +physics based equation that tells you +how much energy is there per bit uh + + align:start position:0% +how much energy is there per bit uh + + + align:start position:0% +how much energy is there per bit uh +what's the signal to noise ratio on a + + align:start position:0% +what's the signal to noise ratio on a + + + align:start position:0% +what's the signal to noise ratio on a +per bit basis and this is a function of + + align:start position:0% +per bit basis and this is a function of + + + align:start position:0% +per bit basis and this is a function of +you know transmitter power receiver and + + align:start position:0% +you know transmitter power receiver and + + + align:start position:0% +you know transmitter power receiver and +transmission gains various losses in the + + align:start position:0% +transmission gains various losses in the + + + align:start position:0% +transmission gains various losses in the +system and then some of the equations + + align:start position:0% +system and then some of the equations + + + align:start position:0% +system and then some of the equations +are some of the information is empirical + + align:start position:0% +are some of the information is empirical + + + align:start position:0% +are some of the information is empirical +for example the relationship between + + align:start position:0% +for example the relationship between + + + align:start position:0% +for example the relationship between +spacecraft wet mass and payo power you + + align:start position:0% +spacecraft wet mass and payo power you + + + align:start position:0% +spacecraft wet mass and payo power you +know if you wanted to have a closed form + + align:start position:0% +know if you wanted to have a closed form + + + align:start position:0% +know if you wanted to have a closed form +or you wanted to have more detail you + + align:start position:0% +or you wanted to have more detail you + + + align:start position:0% +or you wanted to have more detail you +would have to almost build like a cad + + align:start position:0% +would have to almost build like a cad + + + align:start position:0% +would have to almost build like a cad +model right a separate model you'd have + + align:start position:0% +model right a separate model you'd have + + + align:start position:0% +model right a separate model you'd have +for each of these 1440 architectures + + align:start position:0% +for each of these 1440 architectures + + + align:start position:0% +for each of these 1440 architectures +you'd have to manually construct an + + align:start position:0% +you'd have to manually construct an + + + align:start position:0% +you'd have to manually construct an +individual um detailed design and that's + + align:start position:0% +individual um detailed design and that's + + + align:start position:0% +individual um detailed design and that's +not feasible so what you do instead is + + align:start position:0% +not feasible so what you do instead is + + + align:start position:0% +not feasible so what you do instead is +you use some prior data and you can see + + align:start position:0% +you use some prior data and you can see + + + align:start position:0% +you use some prior data and you can see +here uh a a scaling relationship it's + + align:start position:0% +here uh a a scaling relationship it's + + + align:start position:0% +here uh a a scaling relationship it's +not perfect but we we can um you know we + + align:start position:0% +not perfect but we we can um you know we + + + align:start position:0% +not perfect but we we can um you know we +have air bars we know how good it is + + align:start position:0% +have air bars we know how good it is + + + align:start position:0% +have air bars we know how good it is +satellite Mass satellite uh wet mass as + + align:start position:0% +satellite Mass satellite uh wet mass as + + + align:start position:0% +satellite Mass satellite uh wet mass as +a function of transmitter power and in + + align:start position:0% +a function of transmitter power and in + + + align:start position:0% +a function of transmitter power and in +this case propellant Mass okay so two + + align:start position:0% +this case propellant Mass okay so two + + + align:start position:0% +this case propellant Mass okay so two +kinds of + + align:start position:0% +kinds of + + + align:start position:0% +kinds of +equations bench marking uh so once you + + align:start position:0% +equations bench marking uh so once you + + + align:start position:0% +equations bench marking uh so once you +have this model you need to ask the + + align:start position:0% +have this model you need to ask the + + + align:start position:0% +have this model you need to ask the +question how can I trust this model does + + align:start position:0% +question how can I trust this model does + + + align:start position:0% +question how can I trust this model does +it give me reasonable reasonable answers + + align:start position:0% +it give me reasonable reasonable answers + + + align:start position:0% +it give me reasonable reasonable answers +and in this case uh benchmarking is the + + align:start position:0% +and in this case uh benchmarking is the + + + align:start position:0% +and in this case uh benchmarking is the +process of validating simulation by + + align:start position:0% +process of validating simulation by + + + align:start position:0% +process of validating simulation by +comparing the predicted response against + + align:start position:0% +comparing the predicted response against + + + align:start position:0% +comparing the predicted response against +reality so just quickly here showing you + + align:start position:0% +reality so just quickly here showing you + + + align:start position:0% +reality so just quickly here showing you +four kinds of data so one of the + + align:start position:0% +four kinds of data so one of the + + + align:start position:0% +four kinds of data so one of the +simultaneous channels of the + + align:start position:0% +simultaneous channels of the + + + align:start position:0% +simultaneous channels of the +constellation this is the prediction of + + align:start position:0% +constellation this is the prediction of + + + align:start position:0% +constellation this is the prediction of +capacity uh you can see it's pretty good + + align:start position:0% +capacity uh you can see it's pretty good + + + align:start position:0% +capacity uh you can see it's pretty good +uh in this case the model is actually a + + align:start position:0% +uh in this case the model is actually a + + + align:start position:0% +uh in this case the model is actually a +little conservative so the blue bars are + + align:start position:0% +little conservative so the blue bars are + + + align:start position:0% +little conservative so the blue bars are +the actual or planned capacities the red + + align:start position:0% +the actual or planned capacities the red + + + align:start position:0% +the actual or planned capacities the red +ones or magenta is simulated and you can + + align:start position:0% +ones or magenta is simulated and you can + + + align:start position:0% +ones or magenta is simulated and you can +see that the simulation underpredicts + + align:start position:0% +see that the simulation underpredicts + + + align:start position:0% +see that the simulation underpredicts +slightly the true capacity of the system + + align:start position:0% +slightly the true capacity of the system + + + align:start position:0% +slightly the true capacity of the system +um life cycle cost you saw that idium + + align:start position:0% +um life cycle cost you saw that idium + + + align:start position:0% +um life cycle cost you saw that idium +was just a bit more than 5 billion uh + + align:start position:0% +was just a bit more than 5 billion uh + + + align:start position:0% +was just a bit more than 5 billion uh +global star was between three and four + + align:start position:0% +global star was between three and four + + + align:start position:0% +global star was between three and four +and so uh here we're in the right + + align:start position:0% +and so uh here we're in the right + + + align:start position:0% +and so uh here we're in the right +Ballpark and then in terms of satellite + + align:start position:0% +Ballpark and then in terms of satellite + + + align:start position:0% +Ballpark and then in terms of satellite +mass and the number of satellites in the + + align:start position:0% +mass and the number of satellites in the + + + align:start position:0% +mass and the number of satellites in the +constellation required we match that + + align:start position:0% +constellation required we match that + + + align:start position:0% +constellation required we match that +very closely and the reason for this is + + align:start position:0% +very closely and the reason for this is + + + align:start position:0% +very closely and the reason for this is +fundamentally this is just geometry + + align:start position:0% +fundamentally this is just geometry + + + align:start position:0% +fundamentally this is just geometry +right if if I tell you the altitude and + + align:start position:0% +right if if I tell you the altitude and + + + align:start position:0% +right if if I tell you the altitude and +the minimum elevation angle and I'm + + align:start position:0% +the minimum elevation angle and I'm + + + align:start position:0% +the minimum elevation angle and I'm +telling you I need I need Global + + align:start position:0% +telling you I need I need Global + + + align:start position:0% +telling you I need I need Global +coverage and I want dual redundancy so + + align:start position:0% +coverage and I want dual redundancy so + + + align:start position:0% +coverage and I want dual redundancy so +you can always see at least two + + align:start position:0% +you can always see at least two + + + align:start position:0% +you can always see at least two +satellites it's just geometry to figure + + align:start position:0% +satellites it's just geometry to figure + + + align:start position:0% +satellites it's just geometry to figure +out how many satellites and how many + + align:start position:0% +out how many satellites and how many + + + align:start position:0% +out how many satellites and how many +orbital planes you need and that's why + + align:start position:0% +orbital planes you need and that's why + + + align:start position:0% +orbital planes you need and that's why +the model or the simulation and reality + + align:start position:0% +the model or the simulation and reality + + + align:start position:0% +the model or the simulation and reality +match very very closely so this gives + + align:start position:0% +match very very closely so this gives + + + align:start position:0% +match very very closely so this gives +you know some confidence that that that + + align:start position:0% +you know some confidence that that that + + + align:start position:0% +you know some confidence that that that +these results that this model is is + + align:start position:0% +these results that this model is is + + + align:start position:0% +these results that this model is is +reasonable so what you can do with it is + + align:start position:0% +reasonable so what you can do with it is + + + align:start position:0% +reasonable so what you can do with it is +now what we call Trade space exploration + + align:start position:0% +now what we call Trade space exploration + + + align:start position:0% +now what we call Trade space exploration +which is in a sense what you did uh what + + align:start position:0% +which is in a sense what you did uh what + + + align:start position:0% +which is in a sense what you did uh what +you did for the canat competition so + + align:start position:0% +you did for the canat competition so + + + align:start position:0% +you did for the canat competition so +this this picture here this graph shows + + align:start position:0% +this this picture here this graph shows + + + align:start position:0% +this this picture here this graph shows +you the life cyle cost right over those + + align:start position:0% +you the life cyle cost right over those + + + align:start position:0% +you the life cyle cost right over those +15 years versus global capacity of the + + align:start position:0% +15 years versus global capacity of the + + + align:start position:0% +15 years versus global capacity of the +system each of these blue dots + + align:start position:0% +system each of these blue dots + + + align:start position:0% +system each of these blue dots +represents one of those 1440 + + align:start position:0% +represents one of those 1440 + + + align:start position:0% +represents one of those 1440 +architectures and you can even see on + + align:start position:0% +architectures and you can even see on + + + align:start position:0% +architectures and you can even see on +this uh where iridium actual versus + + align:start position:0% +this uh where iridium actual versus + + + align:start position:0% +this uh where iridium actual versus +simulated Falls and where Global star + + align:start position:0% +simulated Falls and where Global star + + + align:start position:0% +simulated Falls and where Global star +actual versus simulated Falls so both of + + align:start position:0% +actual versus simulated Falls so both of + + + align:start position:0% +actual versus simulated Falls so both of +them were actually off the Pito Frontier + + align:start position:0% +them were actually off the Pito Frontier + + + align:start position:0% +them were actually off the Pito Frontier +which was interesting and led to quite + + align:start position:0% +which was interesting and led to quite + + + align:start position:0% +which was interesting and led to quite +some discussions and uh you can the pero + + align:start position:0% +some discussions and uh you can the pero + + + align:start position:0% +some discussions and uh you can the pero +Frontier in itself is a of course very + + align:start position:0% +Frontier in itself is a of course very + + + align:start position:0% +Frontier in itself is a of course very +useful uh one of the reasons that idium + + align:start position:0% +useful uh one of the reasons that idium + + + align:start position:0% +useful uh one of the reasons that idium +is not on the Pito Frontier is that + + align:start position:0% +is not on the Pito Frontier is that + + + align:start position:0% +is not on the Pito Frontier is that +fundamentally polar constellations are + + align:start position:0% +fundamentally polar constellations are + + + align:start position:0% +fundamentally polar constellations are +inefficient and if you think about it + + align:start position:0% +inefficient and if you think about it + + + align:start position:0% +inefficient and if you think about it +when the satellites are crossing over + + align:start position:0% +when the satellites are crossing over + + + align:start position:0% +when the satellites are crossing over +the PO uh they're very close to each + + align:start position:0% +the PO uh they're very close to each + + + align:start position:0% +the PO uh they're very close to each +other and they're actually not Crossing + + align:start position:0% +other and they're actually not Crossing + + + align:start position:0% +other and they're actually not Crossing +exactly over the poles or you you could + + align:start position:0% +exactly over the poles or you you could + + + align:start position:0% +exactly over the poles or you you could +actually Collide right so you you offset + + align:start position:0% +actually Collide right so you you offset + + + align:start position:0% +actually Collide right so you you offset +them slightly to avoid collisions but + + align:start position:0% +them slightly to avoid collisions but + + + align:start position:0% +them slightly to avoid collisions but +um uh some of the satellites actually + + align:start position:0% +um uh some of the satellites actually + + + align:start position:0% +um uh some of the satellites actually +get get turned off when they cost the PO + + align:start position:0% +get get turned off when they cost the PO + + + align:start position:0% +get get turned off when they cost the PO +so you're not utilizing your assets + + align:start position:0% +so you're not utilizing your assets + + + align:start position:0% +so you're not utilizing your assets +super efficiently in a polar + + align:start position:0% +super efficiently in a polar + + + align:start position:0% +super efficiently in a polar +constellation which is one of the + + align:start position:0% +constellation which is one of the + + + align:start position:0% +constellation which is one of the +reasons why they're not on Theo front + + align:start position:0% +reasons why they're not on Theo front + + + align:start position:0% +reasons why they're not on Theo front +now the way you would use this in a + + align:start position:0% +now the way you would use this in a + + + align:start position:0% +now the way you would use this in a +traditional system engineering approach + + align:start position:0% +traditional system engineering approach + + + align:start position:0% +traditional system engineering approach +which is traditional system engineering + + align:start position:0% +which is traditional system engineering + + + align:start position:0% +which is traditional system engineering +approach means give me the requirement + + align:start position:0% +approach means give me the requirement + + + align:start position:0% +approach means give me the requirement +right write down the requirement and + + align:start position:0% +right write down the requirement and + + + align:start position:0% +right write down the requirement and +then find the minimum cost system for + + align:start position:0% +then find the minimum cost system for + + + align:start position:0% +then find the minimum cost system for +that requirement so a requirement could + + align:start position:0% +that requirement so a requirement could + + + align:start position:0% +that requirement so a requirement could +be you know we need a capacity of of you + + align:start position:0% +be you know we need a capacity of of you + + + align:start position:0% +be you know we need a capacity of of you +know 50,000 for example and then you + + align:start position:0% +know 50,000 for example and then you + + + align:start position:0% +know 50,000 for example and then you +find this intersection with the pedo + + align:start position:0% +find this intersection with the pedo + + + align:start position:0% +find this intersection with the pedo +front and that's the system you that's + + align:start position:0% +front and that's the system you that's + + + align:start position:0% +front and that's the system you that's +the minimum life cycle cost design that + + align:start position:0% +the minimum life cycle cost design that + + + align:start position:0% +the minimum life cycle cost design that +gives you that capacity right and that's + + align:start position:0% +gives you that capacity right and that's + + + align:start position:0% +gives you that capacity right and that's +the system you take and that's what you + + align:start position:0% +the system you take and that's what you + + + align:start position:0% +the system you take and that's what you +go and build and that's essentially what + + align:start position:0% +go and build and that's essentially what + + + align:start position:0% +go and build and that's essentially what +they did the problem with this if + + align:start position:0% +they did the problem with this if + + + align:start position:0% +they did the problem with this if +there's High uncertainty is the true + + align:start position:0% +there's High uncertainty is the true + + + align:start position:0% +there's High uncertainty is the true +requirement is kind of unknown right the + + align:start position:0% +requirement is kind of unknown right the + + + align:start position:0% +requirement is kind of unknown right the +market will tell us in the future what + + align:start position:0% +market will tell us in the future what + + + align:start position:0% +market will tell us in the future what +the true capacity should be so how do + + align:start position:0% +the true capacity should be so how do + + + align:start position:0% +the true capacity should be so how do +you deal with this well you could be oh + + align:start position:0% +you deal with this well you could be oh + + + align:start position:0% +you deal with this well you could be oh +we we're going to be on the safe side + + align:start position:0% +we we're going to be on the safe side + + + align:start position:0% +we we're going to be on the safe side +right we're going to be um uh we're + + align:start position:0% +right we're going to be um uh we're + + + align:start position:0% +right we're going to be um uh we're +going to oversize so if the true demand + + align:start position:0% +going to oversize so if the true demand + + + align:start position:0% +going to oversize so if the true demand +the true capacity that you would need is + + align:start position:0% +the true capacity that you would need is + + + align:start position:0% +the true capacity that you would need is +higher than what you've had your your + + align:start position:0% +higher than what you've had your your + + + align:start position:0% +higher than what you've had your your +system is going to be under capacity + + align:start position:0% +system is going to be under capacity + + + align:start position:0% +system is going to be under capacity +right your system is going to be + + align:start position:0% +right your system is going to be + + + align:start position:0% +right your system is going to be +undersized for what it should be and so + + align:start position:0% +undersized for what it should be and so + + + align:start position:0% +undersized for what it should be and so +what happens in practice uh what do you + + align:start position:0% +what happens in practice uh what do you + + + align:start position:0% +what happens in practice uh what do you +think happens in an underc capacity + + align:start position:0% +think happens in an underc capacity + + + align:start position:0% +think happens in an underc capacity +situation + + align:start position:0% + + + + align:start position:0% + +what would you + + align:start position:0% + + + + align:start position:0% + +say your system is too small relative to + + align:start position:0% +say your system is too small relative to + + + align:start position:0% +say your system is too small relative to +the market + + align:start position:0% + + + + align:start position:0% + +demand you're not capturing as much as + + align:start position:0% +demand you're not capturing as much as + + + align:start position:0% +demand you're not capturing as much as +you can meaning a competitor will + + align:start position:0% +you can meaning a competitor will + + + align:start position:0% +you can meaning a competitor will +probably capture it I mean I guess you + + align:start position:0% +probably capture it I mean I guess you + + + align:start position:0% +probably capture it I mean I guess you +can you can change your price policy but + + align:start position:0% +can you can change your price policy but + + + align:start position:0% +can you can change your price policy but +fundamentally you're missing out on + + align:start position:0% +fundamentally you're missing out on + + + align:start position:0% +fundamentally you're missing out on +Market opportunity right the other + + align:start position:0% +Market opportunity right the other + + + align:start position:0% +Market opportunity right the other +situation which is actually what + + align:start position:0% +situation which is actually what + + + align:start position:0% +situation which is actually what +happened is that the demand is much less + + align:start position:0% +happened is that the demand is much less + + + align:start position:0% +happened is that the demand is much less +than you anticipated your system is + + align:start position:0% +than you anticipated your system is + + + align:start position:0% +than you anticipated your system is +oversized and remember once you launch a + + align:start position:0% +oversized and remember once you launch a + + + align:start position:0% +oversized and remember once you launch a +satellite constellation it's not like a + + align:start position:0% +satellite constellation it's not like a + + + align:start position:0% +satellite constellation it's not like a +fleet of taxis right where you just park + + align:start position:0% +fleet of taxis right where you just park + + + align:start position:0% +fleet of taxis right where you just park +them in a in a in a in a parking lot uh + + align:start position:0% +them in a in a in a in a parking lot uh + + + align:start position:0% +them in a in a in a in a parking lot uh +you've already the fixed cost is very + + align:start position:0% +you've already the fixed cost is very + + + align:start position:0% +you've already the fixed cost is very +high so um if if if demand is below + + align:start position:0% +high so um if if if demand is below + + + align:start position:0% +high so um if if if demand is below +capacity you have this all this + + align:start position:0% +capacity you have this all this + + + align:start position:0% +capacity you have this all this +investment here life cycle cost has been + + align:start position:0% +investment here life cycle cost has been + + + align:start position:0% +investment here life cycle cost has been +wasted right because you're oversiz the + + align:start position:0% +wasted right because you're oversiz the + + + align:start position:0% +wasted right because you're oversiz the +system and and the challenge is that the + + align:start position:0% +system and and the challenge is that the + + + align:start position:0% +system and and the challenge is that the +true requirement is kind of like this + + align:start position:0% +true requirement is kind of like this + + + align:start position:0% +true requirement is kind of like this +there's this probability density + + align:start position:0% +there's this probability density + + + align:start position:0% +there's this probability density +function right there's a it's a + + align:start position:0% +function right there's a it's a + + + align:start position:0% +function right there's a it's a +probabilistic requirement essentially + + align:start position:0% +probabilistic requirement essentially + + + align:start position:0% +probabilistic requirement essentially +and and there's no set of experiments + + align:start position:0% +and and there's no set of experiments + + + align:start position:0% +and and there's no set of experiments +because it's aloric uncertainty it's not + + align:start position:0% +because it's aloric uncertainty it's not + + + align:start position:0% +because it's aloric uncertainty it's not +epistemic uncertainty there's no set of + + align:start position:0% +epistemic uncertainty there's no set of + + + align:start position:0% +epistemic uncertainty there's no set of +experiments you could do today that will + + align:start position:0% +experiments you could do today that will + + + align:start position:0% +experiments you could do today that will +help you refine the requirement now they + + align:start position:0% +help you refine the requirement now they + + + align:start position:0% +help you refine the requirement now they +did do Market studies uh and but again + + align:start position:0% +did do Market studies uh and but again + + + align:start position:0% +did do Market studies uh and but again +those Market studies were years ahead of + + align:start position:0% +those Market studies were years ahead of + + + align:start position:0% +those Market studies were years ahead of +when the actual system was launched so + + align:start position:0% +when the actual system was launched so + + + align:start position:0% +when the actual system was launched so +they were unreliable fundamentally so um + + align:start position:0% +they were unreliable fundamentally so um + + + align:start position:0% +they were unreliable fundamentally so um +what I'm arguing here is in this kind of + + align:start position:0% +what I'm arguing here is in this kind of + + + align:start position:0% +what I'm arguing here is in this kind of +system where you have large + + align:start position:0% +system where you have large + + + align:start position:0% +system where you have large +uncertainties as to the true requirement + + align:start position:0% +uncertainties as to the true requirement + + + align:start position:0% +uncertainties as to the true requirement +you shouldn't just guess and then put + + align:start position:0% +you shouldn't just guess and then put + + + align:start position:0% +you shouldn't just guess and then put +billions of dollars on a guess this is + + align:start position:0% +billions of dollars on a guess this is + + + align:start position:0% +billions of dollars on a guess this is +like playing in the casino right + + align:start position:0% +like playing in the casino right + + + align:start position:0% +like playing in the casino right +essentially what you should do is think + + align:start position:0% +essentially what you should do is think + + + align:start position:0% +essentially what you should do is think +about the problem differently and in + + align:start position:0% +about the problem differently and in + + + align:start position:0% +about the problem differently and in +this case the answer is stage deployment + + align:start position:0% +this case the answer is stage deployment + + + align:start position:0% +this case the answer is stage deployment +or one of the aners is stage deployment + + align:start position:0% +or one of the aners is stage deployment + + + align:start position:0% +or one of the aners is stage deployment +so you build the system such that it can + + align:start position:0% +so you build the system such that it can + + + align:start position:0% +so you build the system such that it can +uh adapt itself to the uncertain demand + + align:start position:0% +uh adapt itself to the uncertain demand + + + align:start position:0% +uh adapt itself to the uncertain demand +so uh you build initially a smaller more + + align:start position:0% +so uh you build initially a smaller more + + + align:start position:0% +so uh you build initially a smaller more +affordable system but and then the + + align:start position:0% +affordable system but and then the + + + align:start position:0% +affordable system but and then the +system has already built into it the + + align:start position:0% +system has already built into it the + + + align:start position:0% +system has already built into it the +flexibility or scalability to expand if + + align:start position:0% +flexibility or scalability to expand if + + + align:start position:0% +flexibility or scalability to expand if +needed but only if + + align:start position:0% +needed but only if + + + align:start position:0% +needed but only if +needed and there are two major uh + + align:start position:0% +needed and there are two major uh + + + align:start position:0% +needed and there are two major uh +economic advantages to that one is that + + align:start position:0% +economic advantages to that one is that + + + align:start position:0% +economic advantages to that one is that +you don't need to spend all the capital + + align:start position:0% +you don't need to spend all the capital + + + align:start position:0% +you don't need to spend all the capital +up front right so you're deferring + + align:start position:0% +up front right so you're deferring + + + align:start position:0% +up front right so you're deferring +capital investment and you retain the + + align:start position:0% +capital investment and you retain the + + + align:start position:0% +capital investment and you retain the +decision freedom to reconfig + + align:start position:0% +decision freedom to reconfig + + + align:start position:0% +decision freedom to reconfig +or not and that's typically what we call + + align:start position:0% +or not and that's typically what we call + + + align:start position:0% +or not and that's typically what we call +a real option You' created a real option + + align:start position:0% +a real option You' created a real option + + + align:start position:0% +a real option You' created a real option +uh for the + + align:start position:0% +uh for the + + + align:start position:0% +uh for the +future so the question then is well how + + align:start position:0% +future so the question then is well how + + + align:start position:0% +future so the question then is well how +valuable is that you know is it + + align:start position:0% +valuable is that you know is it + + + align:start position:0% +valuable is that you know is it +worthwhile doing this stage deployment + + align:start position:0% +worthwhile doing this stage deployment + + + align:start position:0% +worthwhile doing this stage deployment +approach so um there's probably + + align:start position:0% +approach so um there's probably + + + align:start position:0% +approach so um there's probably +different ways of doing this and I just + + align:start position:0% +different ways of doing this and I just + + + align:start position:0% +different ways of doing this and I just +want to share with you and this is from + + align:start position:0% +want to share with you and this is from + + + align:start position:0% +want to share with you and this is from +the paper how this was done so step one + + align:start position:0% +the paper how this was done so step one + + + align:start position:0% +the paper how this was done so step one +is you partition Your Design Vector so + + align:start position:0% +is you partition Your Design Vector so + + + align:start position:0% +is you partition Your Design Vector so +you basically decide which which part of + + align:start position:0% +you basically decide which which part of + + + align:start position:0% +you basically decide which which part of +the system is flexible cuz you can't + + align:start position:0% +the system is flexible cuz you can't + + + align:start position:0% +the system is flexible cuz you can't +make everything flexible typically what + + align:start position:0% +make everything flexible typically what + + + align:start position:0% +make everything flexible typically what +part is flexible and what part is fixed + + align:start position:0% +part is flexible and what part is fixed + + + align:start position:0% +part is flexible and what part is fixed +is the base you can't change it so in + + align:start position:0% +is the base you can't change it so in + + + align:start position:0% +is the base you can't change it so in +this case uh excuse me the idea is that + + align:start position:0% +this case uh excuse me the idea is that + + + align:start position:0% +this case uh excuse me the idea is that +the satellites themselves the design of + + align:start position:0% +the satellites themselves the design of + + + align:start position:0% +the satellites themselves the design of +the satellites their transmitter power + + align:start position:0% +the satellites their transmitter power + + + align:start position:0% +the satellites their transmitter power +their protocols their antenna size the + + align:start position:0% +their protocols their antenna size the + + + align:start position:0% +their protocols their antenna size the +network architecture should be fixed + + align:start position:0% +network architecture should be fixed + + + align:start position:0% +network architecture should be fixed +right because those things are difficult + + align:start position:0% +right because those things are difficult + + + align:start position:0% +right because those things are difficult +to change uh but we're going to allow + + align:start position:0% +to change uh but we're going to allow + + + align:start position:0% +to change uh but we're going to allow +the astrodynamics the actual shape of + + align:start position:0% +the astrodynamics the actual shape of + + + align:start position:0% +the astrodynamics the actual shape of +the constellation to be flexible so keep + + align:start position:0% +the constellation to be flexible so keep + + + align:start position:0% +the constellation to be flexible so keep +the satellites the same only change + + align:start position:0% +the satellites the same only change + + + align:start position:0% +the satellites the same only change +their arrangement in space so what you + + align:start position:0% +their arrangement in space so what you + + + align:start position:0% +their arrangement in space so what you +do is you partition the design Vector + + align:start position:0% +do is you partition the design Vector + + + align:start position:0% +do is you partition the design Vector +into the flexible and inflexible + + align:start position:0% +into the flexible and inflexible + + + align:start position:0% +into the flexible and inflexible +part and when you do this in step two + + align:start position:0% +part and when you do this in step two + + + align:start position:0% +part and when you do this in step two +what's nice about this is you can then + + align:start position:0% +what's nice about this is you can then + + + align:start position:0% +what's nice about this is you can then +actually find families of designs right + + align:start position:0% +actually find families of designs right + + + align:start position:0% +actually find families of designs right +you can find families of designs where + + align:start position:0% +you can find families of designs where + + + align:start position:0% +you can find families of designs where +the we do have a little lag here the the + + align:start position:0% +the we do have a little lag here the the + + + align:start position:0% +the we do have a little lag here the the +you can find families of designs that + + align:start position:0% +you can find families of designs that + + + align:start position:0% +you can find families of designs that +share the constant part right that have + + align:start position:0% +share the constant part right that have + + + align:start position:0% +share the constant part right that have +the common so what I'm what's shown in + + align:start position:0% +the common so what I'm what's shown in + + + align:start position:0% +the common so what I'm what's shown in +this graph here this is again our design + + align:start position:0% +this graph here this is again our design + + + align:start position:0% +this graph here this is again our design +space kind of zoomed in a little bit + + align:start position:0% +space kind of zoomed in a little bit + + + align:start position:0% +space kind of zoomed in a little bit +more every one of these points that's + + align:start position:0% +more every one of these points that's + + + align:start position:0% +more every one of these points that's +connected with these lines uses the same + + align:start position:0% +connected with these lines uses the same + + + align:start position:0% +connected with these lines uses the same +type of + + align:start position:0% +type of + + + align:start position:0% +type of +satellite same transmitter power same + + align:start position:0% +satellite same transmitter power same + + + align:start position:0% +satellite same transmitter power same +antenna diameter and all of them have + + align:start position:0% +antenna diameter and all of them have + + + align:start position:0% +antenna diameter and all of them have +inner satellite links so so what + + align:start position:0% +inner satellite links so so what + + + align:start position:0% +inner satellite links so so what +effectively you're partitioning the + + align:start position:0% +effectively you're partitioning the + + + align:start position:0% +effectively you're partitioning the +design space into sub sets that share + + align:start position:0% +design space into sub sets that share + + + align:start position:0% +design space into sub sets that share +common features and then we call this a + + align:start position:0% +common features and then we call this a + + + align:start position:0% +common features and then we call this a +family of designs and the idea is you + + align:start position:0% +family of designs and the idea is you + + + align:start position:0% +family of designs and the idea is you +start small so on the left side and then + + align:start position:0% +start small so on the left side and then + + + align:start position:0% +start small so on the left side and then +you grow the system over time right but + + align:start position:0% +you grow the system over time right but + + + align:start position:0% +you grow the system over time right but +only if needed so when you do this your + + align:start position:0% +only if needed so when you do this your + + + align:start position:0% +only if needed so when you do this your +1440 um um strong design space turns out + + align:start position:0% +1440 um um strong design space turns out + + + align:start position:0% +1440 um um strong design space turns out +to be decomposable into 40 different + + align:start position:0% +to be decomposable into 40 different + + + align:start position:0% +to be decomposable into 40 different +paths now which path would you choose + + align:start position:0% +paths now which path would you choose + + + align:start position:0% +paths now which path would you choose +here well want to be as close to the + + align:start position:0% +here well want to be as close to the + + + align:start position:0% +here well want to be as close to the +Pito front as possible so this is an + + align:start position:0% +Pito front as possible so this is an + + + align:start position:0% +Pito front as possible so this is an +example of a of a path in this in this + + align:start position:0% +example of a of a path in this in this + + + align:start position:0% +example of a of a path in this in this +path if we started on the lower left we + + align:start position:0% +path if we started on the lower left we + + + align:start position:0% +path if we started on the lower left we +would start with 24 satellites and then + + align:start position:0% +would start with 24 satellites and then + + + align:start position:0% +would start with 24 satellites and then +uh we would actually move them uh to a + + align:start position:0% +uh we would actually move them uh to a + + + align:start position:0% +uh we would actually move them uh to a +lower altitude and add uh 30 more in + + align:start position:0% +lower altitude and add uh 30 more in + + + align:start position:0% +lower altitude and add uh 30 more in +step two and then you you would + + align:start position:0% +step two and then you you would + + + align:start position:0% +step two and then you you would +gradually grow the constellation over + + align:start position:0% +gradually grow the constellation over + + + align:start position:0% +gradually grow the constellation over +time you see that this is actually not + + align:start position:0% +time you see that this is actually not + + + align:start position:0% +time you see that this is actually not +too different from how GPS was done + + align:start position:0% +too different from how GPS was done + + + align:start position:0% +too different from how GPS was done +right the GPS + + align:start position:0% +right the GPS + + + align:start position:0% +right the GPS +constellation was was deployed in phases + + align:start position:0% +constellation was was deployed in phases + + + align:start position:0% +constellation was was deployed in phases +but it was not Market driven it was just + + align:start position:0% +but it was not Market driven it was just + + + align:start position:0% +but it was not Market driven it was just +sort of phasing the development for for + + align:start position:0% +sort of phasing the development for for + + + align:start position:0% +sort of phasing the development for for +risk reduction regions and spreading out + + align:start position:0% +risk reduction regions and spreading out + + + align:start position:0% +risk reduction regions and spreading out +the capital um the other thing that's + + align:start position:0% +the capital um the other thing that's + + + align:start position:0% +the capital um the other thing that's +interesting here is you see as you grow + + align:start position:0% +interesting here is you see as you grow + + + align:start position:0% +interesting here is you see as you grow +the constellation it moves further away + + align:start position:0% +the constellation it moves further away + + + align:start position:0% +the constellation it moves further away +see it moves further away from the front + + align:start position:0% +see it moves further away from the front + + + align:start position:0% +see it moves further away from the front +so when it's small this particular path + + align:start position:0% +so when it's small this particular path + + + align:start position:0% +so when it's small this particular path +it's close to being optimal and as you + + align:start position:0% +it's close to being optimal and as you + + + align:start position:0% +it's close to being optimal and as you +scale it up it becomes more suboptimal + + align:start position:0% +scale it up it becomes more suboptimal + + + align:start position:0% +scale it up it becomes more suboptimal +and there's other paths + + align:start position:0% +and there's other paths + + + align:start position:0% +and there's other paths +that have the opposite Behavior where + + align:start position:0% +that have the opposite Behavior where + + + align:start position:0% +that have the opposite Behavior where +when it's small it's kind of suboptimal + + align:start position:0% +when it's small it's kind of suboptimal + + + align:start position:0% +when it's small it's kind of suboptimal +and as you make it bigger it gets closer + + align:start position:0% +and as you make it bigger it gets closer + + + align:start position:0% +and as you make it bigger it gets closer +to optimality pretty interesting so + + align:start position:0% +to optimality pretty interesting so + + + align:start position:0% +to optimality pretty interesting so +that's step two find the + + align:start position:0% +that's step two find the + + + align:start position:0% +that's step two find the +paths step three you now have to model + + align:start position:0% +paths step three you now have to model + + + align:start position:0% +paths step three you now have to model +the actual uncertainty and in this case + + align:start position:0% +the actual uncertainty and in this case + + + align:start position:0% +the actual uncertainty and in this case +uh there are different ways to model + + align:start position:0% +uh there are different ways to model + + + align:start position:0% +uh there are different ways to model +uncertainties uh in this case what we + + align:start position:0% +uncertainties uh in this case what we + + + align:start position:0% +uncertainties uh in this case what we +used was a GBM model geometric brownan + + align:start position:0% +used was a GBM model geometric brownan + + + align:start position:0% +used was a GBM model geometric brownan +motion this is well known in physics uh + + align:start position:0% +motion this is well known in physics uh + + + align:start position:0% +motion this is well known in physics uh +it's been applied to statistics physics + + align:start position:0% +it's been applied to statistics physics + + + align:start position:0% +it's been applied to statistics physics +this has been applied to the stock + + align:start position:0% +this has been applied to the stock + + + align:start position:0% +this has been applied to the stock +market right and and the idea here is + + align:start position:0% +market right and and the idea here is + + + align:start position:0% +market right and and the idea here is +that uh in this case demand uh behaves + + align:start position:0% +that uh in this case demand uh behaves + + + align:start position:0% +that uh in this case demand uh behaves +like a particle in a fluid right that's + + align:start position:0% +like a particle in a fluid right that's + + + align:start position:0% +like a particle in a fluid right that's +that's kind of moving in an + + align:start position:0% +that's kind of moving in an + + + align:start position:0% +that's kind of moving in an +unpredictable fashion so this is the + + align:start position:0% +unpredictable fashion so this is the + + + align:start position:0% +unpredictable fashion so this is the +basic equation for this is the discrete + + align:start position:0% +basic equation for this is the discrete + + + align:start position:0% +basic equation for this is the discrete +version of of geometric Brown and motion + + align:start position:0% +version of of geometric Brown and motion + + + align:start position:0% +version of of geometric Brown and motion +you have um some Trend mu mu * delta T + + align:start position:0% +you have um some Trend mu mu * delta T + + + align:start position:0% +you have um some Trend mu mu * delta T +so the this is the delta in demand the + + align:start position:0% +so the this is the delta in demand the + + + align:start position:0% +so the this is the delta in demand the +change in demand divided by De demand so + + align:start position:0% +change in demand divided by De demand so + + + align:start position:0% +change in demand divided by De demand so +this is normalized change in demand is + + align:start position:0% +this is normalized change in demand is + + + align:start position:0% +this is normalized change in demand is +Mu * delta T so your your Trend time + + align:start position:0% +Mu * delta T so your your Trend time + + + align:start position:0% +Mu * delta T so your your Trend time +delta T plus uh Sigma * Epsilon * square + + align:start position:0% +delta T plus uh Sigma * Epsilon * square + + + align:start position:0% +delta T plus uh Sigma * Epsilon * square +root of delta T Epsilon is a standard + + align:start position:0% +root of delta T Epsilon is a standard + + + align:start position:0% +root of delta T Epsilon is a standard +normally distributed random variable + + align:start position:0% +normally distributed random variable + + + align:start position:0% +normally distributed random variable +between 0 and one and uh Epsilon uh and + + align:start position:0% +between 0 and one and uh Epsilon uh and + + + align:start position:0% +between 0 and one and uh Epsilon uh and +and sigma is your volatility essentially + + align:start position:0% +and sigma is your volatility essentially + + + align:start position:0% +and sigma is your volatility essentially +right so here's here's some examples if + + align:start position:0% +right so here's here's some examples if + + + align:start position:0% +right so here's here's some examples if +you start with with an initial demand of + + align:start position:0% +you start with with an initial demand of + + + align:start position:0% +you start with with an initial demand of +50, ,000 which is what they actually saw + + align:start position:0% +50, ,000 which is what they actually saw + + + align:start position:0% +50, ,000 which is what they actually saw +you know as a as an initial demand early + + align:start position:0% +you know as a as an initial demand early + + + align:start position:0% +you know as a as an initial demand early +on you have a growth of about 8% per + + align:start position:0% +on you have a growth of about 8% per + + + align:start position:0% +on you have a growth of about 8% per +year this is your + + align:start position:0% +year this is your + + + align:start position:0% +year this is your +Trend Plus in this case a volatility of + + align:start position:0% +Trend Plus in this case a volatility of + + + align:start position:0% +Trend Plus in this case a volatility of +40% per year which seems high but you + + align:start position:0% +40% per year which seems high but you + + + align:start position:0% +40% per year which seems high but you +know this kind of very new technology + + align:start position:0% +know this kind of very new technology + + + align:start position:0% +know this kind of very new technology +new systems is actually not that + + align:start position:0% +new systems is actually not that + + + align:start position:0% +new systems is actually not that +far-fetched you get three different + + align:start position:0% +far-fetched you get three different + + + align:start position:0% +far-fetched you get three different +these are there three examples of how + + align:start position:0% +these are there three examples of how + + + align:start position:0% +these are there three examples of how +demand might evolve these are just three + + align:start position:0% +demand might evolve these are just three + + + align:start position:0% +demand might evolve these are just three +scenarios so demand can go up it can go + + align:start position:0% +scenarios so demand can go up it can go + + + align:start position:0% +scenarios so demand can go up it can go +down and GBM is very nice but one of the + + align:start position:0% +down and GBM is very nice but one of the + + + align:start position:0% +down and GBM is very nice but one of the +downsides of GBM is you know there's + + align:start position:0% +downsides of GBM is you know there's + + + align:start position:0% +downsides of GBM is you know there's +infinitely many scenarios that you can + + align:start position:0% +infinitely many scenarios that you can + + + align:start position:0% +infinitely many scenarios that you can +generate because it's fundamentally even + + align:start position:0% +generate because it's fundamentally even + + + align:start position:0% +generate because it's fundamentally even +though it's discretized in time it's not + + align:start position:0% +though it's discretized in time it's not + + + align:start position:0% +though it's discretized in time it's not +discretized in in demand so a simpler + + align:start position:0% +discretized in in demand so a simpler + + + align:start position:0% +discretized in in demand so a simpler +version of this a more discret version + + align:start position:0% +version of this a more discret version + + + align:start position:0% +version of this a more discret version +is a so-called binomial lattice model so + + align:start position:0% +is a so-called binomial lattice model so + + + align:start position:0% +is a so-called binomial lattice model so +the way this works is again you start + + align:start position:0% +the way this works is again you start + + + align:start position:0% +the way this works is again you start +with some initial demand here on the + + align:start position:0% +with some initial demand here on the + + + align:start position:0% +with some initial demand here on the +left and then uh you've disc IED it such + + align:start position:0% +left and then uh you've disc IED it such + + + align:start position:0% +left and then uh you've disc IED it such +that um moving through time you can look + + align:start position:0% +that um moving through time you can look + + + align:start position:0% +that um moving through time you can look +at different scenarios right these scen + + align:start position:0% +at different scenarios right these scen + + + align:start position:0% +at different scenarios right these scen +scenarios could be you know the best + + align:start position:0% +scenarios could be you know the best + + + align:start position:0% +scenarios could be you know the best +scenario is things just keep growing + + align:start position:0% +scenario is things just keep growing + + + align:start position:0% +scenario is things just keep growing +right grow grow grow grow grow here uh + + align:start position:0% +right grow grow grow grow grow here uh + + + align:start position:0% +right grow grow grow grow grow here uh +time the 15 years have been subdivided + + align:start position:0% +time the 15 years have been subdivided + + + align:start position:0% +time the 15 years have been subdivided +into five three threeyear periods so + + align:start position:0% +into five three threeyear periods so + + + align:start position:0% +into five three threeyear periods so +here's a sample scenario demand goes up + + align:start position:0% +here's a sample scenario demand goes up + + + align:start position:0% +here's a sample scenario demand goes up +goes up and then it goes down twice and + + align:start position:0% +goes up and then it goes down twice and + + + align:start position:0% +goes up and then it goes down twice and +then it goes up again in the fifth + + align:start position:0% +then it goes up again in the fifth + + + align:start position:0% +then it goes up again in the fifth +period And so this is is a discretized + + align:start position:0% +period And so this is is a discretized + + + align:start position:0% +period And so this is is a discretized +random walk and you can choose the + + align:start position:0% +random walk and you can choose the + + + align:start position:0% +random walk and you can choose the +numbers so the the sigma the volatility + + align:start position:0% +numbers so the the sigma the volatility + + + align:start position:0% +numbers so the the sigma the volatility +the amount of the up and down movement + + align:start position:0% +the amount of the up and down movement + + + align:start position:0% +the amount of the up and down movement +and the probability P of going up and + + align:start position:0% +and the probability P of going up and + + + align:start position:0% +and the probability P of going up and +then the probability of one minus P of + + align:start position:0% +then the probability of one minus P of + + + align:start position:0% +then the probability of one minus P of +going down are chosen such that they're + + align:start position:0% +going down are chosen such that they're + + + align:start position:0% +going down are chosen such that they're +consistent with the GBM model so this + + align:start position:0% +consistent with the GBM model so this + + + align:start position:0% +consistent with the GBM model so this +model is statistically equivalent to the + + align:start position:0% +model is statistically equivalent to the + + + align:start position:0% +model is statistically equivalent to the +GBM model it's just discretized so the + + align:start position:0% +GBM model it's just discretized so the + + + align:start position:0% +GBM model it's just discretized so the +beauty of this is that you can now + + align:start position:0% +beauty of this is that you can now + + + align:start position:0% +beauty of this is that you can now +simplify this to 32 different scenarios + + align:start position:0% +simplify this to 32 different scenarios + + + align:start position:0% +simplify this to 32 different scenarios +instead of infinitely many and each of + + align:start position:0% +instead of infinitely many and each of + + + align:start position:0% +instead of infinitely many and each of +those + + align:start position:0% +those + + + align:start position:0% +those +scenarios is not equally probable the + + align:start position:0% +scenarios is not equally probable the + + + align:start position:0% +scenarios is not equally probable the +pro there actually probability weighted + + align:start position:0% +pro there actually probability weighted + + + align:start position:0% +pro there actually probability weighted +scenarios depending on what mu and sigma + + align:start position:0% +scenarios depending on what mu and sigma + + + align:start position:0% +scenarios depending on what mu and sigma +are that are underlying right so now we + + align:start position:0% +are that are underlying right so now we + + + align:start position:0% +are that are underlying right so now we +have 40 paths right we have 40 Evolution + + align:start position:0% +have 40 paths right we have 40 Evolution + + + align:start position:0% +have 40 paths right we have 40 Evolution +Paths of the system and we have 32 + + align:start position:0% +Paths of the system and we have 32 + + + align:start position:0% +Paths of the system and we have 32 +different future scenarios so what we do + + align:start position:0% +different future scenarios so what we do + + + align:start position:0% +different future scenarios so what we do +now in the next step four is to put the + + align:start position:0% +now in the next step four is to put the + + + align:start position:0% +now in the next step four is to put the +two together and calculate the cost of + + align:start position:0% +two together and calculate the cost of + + + align:start position:0% +two together and calculate the cost of +each path right calculate the cost of + + align:start position:0% +each path right calculate the cost of + + + align:start position:0% +each path right calculate the cost of +each path with respect to each of the + + align:start position:0% +each path with respect to each of the + + + align:start position:0% +each path with respect to each of the +demand scenarios look at the weighted + + align:start position:0% +demand scenarios look at the weighted + + + align:start position:0% +demand scenarios look at the weighted +average of all the possible paths and uh + + align:start position:0% +average of all the possible paths and uh + + + align:start position:0% +average of all the possible paths and uh +the one thing the trick the one tricky + + align:start position:0% +the one thing the trick the one tricky + + + align:start position:0% +the one thing the trick the one tricky +thing about this is you need to build in + + align:start position:0% +thing about this is you need to build in + + + align:start position:0% +thing about this is you need to build in +a decision rule such that if the system + + align:start position:0% +a decision rule such that if the system + + + align:start position:0% +a decision rule such that if the system +if demand exceeds capacity the system + + align:start position:0% +if demand exceeds capacity the system + + + align:start position:0% +if demand exceeds capacity the system +you're going to expand and move to the + + align:start position:0% +you're going to expand and move to the + + + align:start position:0% +you're going to expand and move to the +next stage you're going to Stage deploy + + align:start position:0% +next stage you're going to Stage deploy + + + align:start position:0% +next stage you're going to Stage deploy +the next phase uh and and there's many + + align:start position:0% +the next phase uh and and there's many + + + align:start position:0% +the next phase uh and and there's many +different ways of doing this decision + + align:start position:0% +different ways of doing this decision + + + align:start position:0% +different ways of doing this decision +rule so the the simplest one was chosen + + align:start position:0% +rule so the the simplest one was chosen + + + align:start position:0% +rule so the the simplest one was chosen +here and of course costs are discounted + + align:start position:0% +here and of course costs are discounted + + + align:start position:0% +here and of course costs are discounted +so let let me explain to you how this + + align:start position:0% +so let let me explain to you how this + + + align:start position:0% +so let let me explain to you how this +works so you know we we start um this + + align:start position:0% +works so you know we we start um this + + + align:start position:0% +works so you know we we start um this +simulation so the first uh initial + + align:start position:0% +simulation so the first uh initial + + + align:start position:0% +simulation so the first uh initial +deployment this is our initial stage one + + align:start position:0% +deployment this is our initial stage one + + + align:start position:0% +deployment this is our initial stage one +right for the constellation and then we + + align:start position:0% +right for the constellation and then we + + + align:start position:0% +right for the constellation and then we +start operating for uh two years demand + + align:start position:0% +start operating for uh two years demand + + + align:start position:0% +start operating for uh two years demand +in this period goes up you see the Ops + + align:start position:0% +in this period goes up you see the Ops + + + align:start position:0% +in this period goes up you see the Ops +cost in this case goes slightly down + + align:start position:0% +cost in this case goes slightly down + + + align:start position:0% +cost in this case goes slightly down +this is due to the discounting this is a + + align:start position:0% +this is due to the discounting this is a + + + align:start position:0% +this is due to the discounting this is a +discounting effect we arrive at the end + + align:start position:0% +discounting effect we arrive at the end + + + align:start position:0% +discounting effect we arrive at the end +of our first threeyear period and then + + align:start position:0% +of our first threeyear period and then + + + align:start position:0% +of our first threeyear period and then +the question is uh here's our capacity + + align:start position:0% +the question is uh here's our capacity + + + align:start position:0% +the question is uh here's our capacity +of the system what would you do in this + + align:start position:0% +of the system what would you do in this + + + align:start position:0% +of the system what would you do in this +situation let me ask somebody at MIT + + align:start position:0% +situation let me ask somebody at MIT + + + align:start position:0% +situation let me ask somebody at MIT +make sure you guys are still are still + + align:start position:0% +make sure you guys are still are still + + + align:start position:0% +make sure you guys are still are still +with me so what would you do in this + + align:start position:0% +with me so what would you do in this + + + align:start position:0% +with me so what would you do in this +situation + + align:start position:0% +situation + + + align:start position:0% +situation +you you're now at the end of year + + align:start position:0% + + + + align:start position:0% + +three + + align:start position:0% + + + + align:start position:0% + +anybody we lost you for a second halfway + + align:start position:0% +anybody we lost you for a second halfway + + + align:start position:0% +anybody we lost you for a second halfway +through your statement could you + + align:start position:0% +through your statement could you + + + align:start position:0% +through your statement could you +repeat yeah so you've you um you've done + + align:start position:0% +repeat yeah so you've you um you've done + + + align:start position:0% +repeat yeah so you've you um you've done +your initial 3 years you've deployed + + align:start position:0% +your initial 3 years you've deployed + + + align:start position:0% +your initial 3 years you've deployed +your initial constellation and you now + + align:start position:0% +your initial constellation and you now + + + align:start position:0% +your initial constellation and you now +have the situation shown on this chart + + align:start position:0% +have the situation shown on this chart + + + align:start position:0% +have the situation shown on this chart +what's the what's the right decision + + align:start position:0% +what's the what's the right decision + + + align:start position:0% +what's the what's the right decision +according to the decision + + align:start position:0% + + + + align:start position:0% + +rule what's the right + + align:start position:0% + + + + align:start position:0% + +decision okay I would keep it the same + + align:start position:0% +decision okay I would keep it the same + + + align:start position:0% +decision okay I would keep it the same +because Haven exceeded Demand + + align:start position:0% +because Haven exceeded Demand + + + align:start position:0% +because Haven exceeded Demand +yet but prepare to exactly you wait + + align:start position:0% +yet but prepare to exactly you wait + + + align:start position:0% +yet but prepare to exactly you wait +right because your is below Your + + align:start position:0% +right because your is below Your + + + align:start position:0% +right because your is below Your +Capacity so you keep it the same you + + align:start position:0% +Capacity so you keep it the same you + + + align:start position:0% +Capacity so you keep it the same you +don't do anything you just keep + + align:start position:0% +don't do anything you just keep + + + align:start position:0% +don't do anything you just keep +operating it's exactly right so um you + + align:start position:0% +operating it's exactly right so um you + + + align:start position:0% +operating it's exactly right so um you +have another three years right um during + + align:start position:0% +have another three years right um during + + + align:start position:0% +have another three years right um during +these three years uh demand keeps + + align:start position:0% +these three years uh demand keeps + + + align:start position:0% +these three years uh demand keeps +growing and you now at at year six + + align:start position:0% +growing and you now at at year six + + + align:start position:0% +growing and you now at at year six +arrive at this point here so what's the + + align:start position:0% +arrive at this point here so what's the + + + align:start position:0% +arrive at this point here so what's the +right decision now can I ask a question + + align:start position:0% +right decision now can I ask a question + + + align:start position:0% +right decision now can I ask a question +about the decision to stay the + + align:start position:0% + + + + align:start position:0% + +same would you stay the + + align:start position:0% +same would you stay the + + + align:start position:0% +same would you stay the +same what what's happening to the demand + + align:start position:0% +same what what's happening to the demand + + + align:start position:0% +same what what's happening to the demand +line Veronica what's happening to the + + align:start position:0% +line Veronica what's happening to the + + + align:start position:0% +line Veronica what's happening to the +demand can I ask a qu a quick question + + align:start position:0% +demand can I ask a qu a quick question + + + align:start position:0% +demand can I ask a qu a quick question +first about the the decision to stay the + + align:start position:0% +first about the the decision to stay the + + + align:start position:0% +first about the the decision to stay the +same yes I feel like by waiting until + + align:start position:0% +same yes I feel like by waiting until + + + align:start position:0% +same yes I feel like by waiting until +we've exceeded demand to choose to + + align:start position:0% +we've exceeded demand to choose to + + + align:start position:0% +we've exceeded demand to choose to +expand the constellation we're + + align:start position:0% +expand the constellation we're + + + align:start position:0% +expand the constellation we're +introducing a lag between demand and + + align:start position:0% +introducing a lag between demand and + + + align:start position:0% +introducing a lag between demand and +capability that creates an inefficiency + + align:start position:0% +capability that creates an inefficiency + + + align:start position:0% +capability that creates an inefficiency +that may actually drive users away from + + align:start position:0% +that may actually drive users away from + + + align:start position:0% +that may actually drive users away from +the system and I see this kind of + + align:start position:0% +the system and I see this kind of + + + align:start position:0% +the system and I see this kind of +oscillatory effect where you would + + align:start position:0% +oscillatory effect where you would + + + align:start position:0% +oscillatory effect where you would +expand and then people would meet and + + align:start position:0% +expand and then people would meet and + + + align:start position:0% +expand and then people would meet and +then the system would be insufficient + + align:start position:0% +then the system would be insufficient + + + align:start position:0% +then the system would be insufficient +and then people would move to a + + align:start position:0% +and then people would move to a + + + align:start position:0% +and then people would move to a +different system and You' kind of have a + + align:start position:0% +different system and You' kind of have a + + + align:start position:0% +different system and You' kind of have a +yo-yo around the the maximum carrying + + align:start position:0% +yo-yo around the the maximum carrying + + + align:start position:0% +yo-yo around the the maximum carrying +capacity and that doesn't seem efficient + + align:start position:0% +capacity and that doesn't seem efficient + + + align:start position:0% +capacity and that doesn't seem efficient +to me so I'm wondering if you could + + align:start position:0% +to me so I'm wondering if you could + + + align:start position:0% +to me so I'm wondering if you could +speak to + + align:start position:0% +speak to + + + align:start position:0% +speak to +that yeah so what you're what you're ESS + + align:start position:0% +that yeah so what you're what you're ESS + + + align:start position:0% +that yeah so what you're what you're ESS +essentially you're arguing for is what I + + align:start position:0% +essentially you're arguing for is what I + + + align:start position:0% +essentially you're arguing for is what I +would call an anticipatory decision rule + + align:start position:0% +would call an anticipatory decision rule + + + align:start position:0% +would call an anticipatory decision rule +so you would actually so the decision + + align:start position:0% +so you would actually so the decision + + + align:start position:0% +so you would actually so the decision +here is to deploy right you got to + + align:start position:0% +here is to deploy right you got to + + + align:start position:0% +here is to deploy right you got to +deploy your second stage because you've + + align:start position:0% +deploy your second stage because you've + + + align:start position:0% +deploy your second stage because you've +saturated the system what you're arguing + + align:start position:0% +saturated the system what you're arguing + + + align:start position:0% +saturated the system what you're arguing +for um is to before this occurs you know + + align:start position:0% +for um is to before this occurs you know + + + align:start position:0% +for um is to before this occurs you know +like at 80% saturation that's when you + + align:start position:0% +like at 80% saturation that's when you + + + align:start position:0% +like at 80% saturation that's when you +trigger the next stage right in order to + + align:start position:0% +trigger the next stage right in order to + + + align:start position:0% +trigger the next stage right in order to +anticipate the um the saturation and so + + align:start position:0% +anticipate the um the saturation and so + + + align:start position:0% +anticipate the um the saturation and so +absolutely you could do this you know + + align:start position:0% +absolutely you could do this you know + + + align:start position:0% +absolutely you could do this you know +there there are many different decision + + align:start position:0% +there there are many different decision + + + align:start position:0% +there there are many different decision +rules that you can try when you design a + + align:start position:0% +rules that you can try when you design a + + + align:start position:0% +rules that you can try when you design a +flexible you know Deployable scalable + + align:start position:0% +flexible you know Deployable scalable + + + align:start position:0% +flexible you know Deployable scalable +system that's part of the decision space + + align:start position:0% +system that's part of the decision space + + + align:start position:0% +system that's part of the decision space +so in this in this particular example uh + + align:start position:0% +so in this in this particular example uh + + + align:start position:0% +so in this in this particular example uh +you know we just implemented the + + align:start position:0% +you know we just implemented the + + + align:start position:0% +you know we just implemented the +simplest possible decision rule which + + align:start position:0% +simplest possible decision rule which + + + align:start position:0% +simplest possible decision rule which +was at when saturation has occurred you + + align:start position:0% +was at when saturation has occurred you + + + align:start position:0% +was at when saturation has occurred you +do deploy the next stage but not before + + align:start position:0% +do deploy the next stage but not before + + + align:start position:0% +do deploy the next stage but not before +okay thank + + align:start position:0% + + + + align:start position:0% + +you is that is that + + align:start position:0% +you is that is that + + + align:start position:0% +you is that is that +clear yes thank + + align:start position:0% +clear yes thank + + + align:start position:0% +clear yes thank +you okay so we we deploy the second + + align:start position:0% +you okay so we we deploy the second + + + align:start position:0% +you okay so we we deploy the second +stage now and you can see there's + + align:start position:0% +stage now and you can see there's + + + align:start position:0% +stage now and you can see there's +another Spike here right of of capital + + align:start position:0% +another Spike here right of of capital + + + align:start position:0% +another Spike here right of of capital +that's needed + + align:start position:0% +that's needed + + + align:start position:0% +that's needed +it's not as high as the first initial + + align:start position:0% +it's not as high as the first initial + + + align:start position:0% +it's not as high as the first initial +stage but it is + + align:start position:0% +stage but it is + + + align:start position:0% +stage but it is +substantial um so now as as we watched + + align:start position:0% +substantial um so now as as we watched + + + align:start position:0% +substantial um so now as as we watched +the as we've deployed the next stage our + + align:start position:0% +the as we've deployed the next stage our + + + align:start position:0% +the as we've deployed the next stage our +capacity went uh to the higher limit so + + align:start position:0% +capacity went uh to the higher limit so + + + align:start position:0% +capacity went uh to the higher limit so +we're now at capacity level two uh we're + + align:start position:0% +we're now at capacity level two uh we're + + + align:start position:0% +we're now at capacity level two uh we're +now operating the system uh demand keeps + + align:start position:0% +now operating the system uh demand keeps + + + align:start position:0% +now operating the system uh demand keeps +growing that's good now we're at year + + align:start position:0% +growing that's good now we're at year + + + align:start position:0% +growing that's good now we're at year +nine uh you can see but we haven't yet + + align:start position:0% +nine uh you can see but we haven't yet + + + align:start position:0% +nine uh you can see but we haven't yet +saturated our new capacity so again the + + align:start position:0% +saturated our new capacity so again the + + + align:start position:0% +saturated our new capacity so again the +optimal decision is is to or I shouldn't + + align:start position:0% +optimal decision is is to or I shouldn't + + + align:start position:0% +optimal decision is is to or I shouldn't +say the optimal decision but the + + align:start position:0% +say the optimal decision but the + + + align:start position:0% +say the optimal decision but the +decision according to the rule is you + + align:start position:0% +decision according to the rule is you + + + align:start position:0% +decision according to the rule is you +just wait right you keep + + align:start position:0% +just wait right you keep + + + align:start position:0% +just wait right you keep +operating ah now from year 9 to year 12 + + align:start position:0% +operating ah now from year 9 to year 12 + + + align:start position:0% +operating ah now from year 9 to year 12 +demand starts to go down right and this + + align:start position:0% +demand starts to go down right and this + + + align:start position:0% +demand starts to go down right and this +happens in some systems right you they + + align:start position:0% +happens in some systems right you they + + + align:start position:0% +happens in some systems right you they +growing and then they Peak and then + + align:start position:0% +growing and then they Peak and then + + + align:start position:0% +growing and then they Peak and then +things go down so in this case we wait + + align:start position:0% +things go down so in this case we wait + + + align:start position:0% +things go down so in this case we wait +and then in this scenario it goes down + + align:start position:0% +and then in this scenario it goes down + + + align:start position:0% +and then in this scenario it goes down +again you see how that works so what's + + align:start position:0% +again you see how that works so what's + + + align:start position:0% +again you see how that works so what's +nice about this is you can + + align:start position:0% +nice about this is you can + + + align:start position:0% +nice about this is you can +now in in this in this sense all the 32 + + align:start position:0% +now in in this in this sense all the 32 + + + align:start position:0% +now in in this in this sense all the 32 +scenarios of possible Futures you can + + align:start position:0% +scenarios of possible Futures you can + + + align:start position:0% +scenarios of possible Futures you can +run them against the 40 different + + align:start position:0% +run them against the 40 different + + + align:start position:0% +run them against the 40 different +families of designs or Evolution paths + + align:start position:0% +families of designs or Evolution paths + + + align:start position:0% +families of designs or Evolution paths +and out of that you can find the best + + align:start position:0% +and out of that you can find the best + + + align:start position:0% +and out of that you can find the best +path right this is the path the path + + align:start position:0% +path right this is the path the path + + + align:start position:0% +path right this is the path the path +that on average I should point out on + + align:start position:0% +that on average I should point out on + + + align:start position:0% +that on average I should point out on +average will satisfy your demand at + + align:start position:0% +average will satisfy your demand at + + + align:start position:0% +average will satisfy your demand at +minimum life cycle cost given the + + align:start position:0% +minimum life cycle cost given the + + + align:start position:0% +minimum life cycle cost given the +uncertainty model that you've imposed + + align:start position:0% +uncertainty model that you've imposed + + + align:start position:0% +uncertainty model that you've imposed +yes + + align:start position:0% + + + + align:start position:0% + +why did it go + + align:start position:0% + + + + align:start position:0% + +down this this + + align:start position:0% + + + + align:start position:0% + +here no the capacity stays the same you + + align:start position:0% +here no the capacity stays the same you + + + align:start position:0% +here no the capacity stays the same you +don't go down in capacity the reason is + + align:start position:0% +don't go down in capacity the reason is + + + align:start position:0% +don't go down in capacity the reason is +this is a good question um this + + align:start position:0% +this is a good question um this + + + align:start position:0% +this is a good question um this +particular system a satellite + + align:start position:0% +particular system a satellite + + + align:start position:0% +particular system a satellite +constellation is dominated by fixed + + align:start position:0% +constellation is dominated by fixed + + + align:start position:0% +constellation is dominated by fixed +costs right so it you wouldn't retire + + align:start position:0% +costs right so it you wouldn't retire + + + align:start position:0% +costs right so it you wouldn't retire +half your satellites because then you + + align:start position:0% +half your satellites because then you + + + align:start position:0% +half your satellites because then you +would lose coverage also potentially + + align:start position:0% +would lose coverage also potentially + + + align:start position:0% +would lose coverage also potentially +right because you move you move move + + align:start position:0% +right because you move you move move + + + align:start position:0% +right because you move you move move +them to orbits that that give you the + + align:start position:0% +them to orbits that that give you the + + + align:start position:0% +them to orbits that that give you the +right coverage you just increase your + + align:start position:0% +right coverage you just increase your + + + align:start position:0% +right coverage you just increase your +capacity this is different from a system + + align:start position:0% +capacity this is different from a system + + + align:start position:0% +capacity this is different from a system +that is dominated by variable costs like + + align:start position:0% +that is dominated by variable costs like + + + align:start position:0% +that is dominated by variable costs like +for example if you operate a fleet of + + align:start position:0% +for example if you operate a fleet of + + + align:start position:0% +for example if you operate a fleet of +taxis you know and and for whatever + + align:start position:0% +taxis you know and and for whatever + + + align:start position:0% +taxis you know and and for whatever +reason demand goes way down you can go + + align:start position:0% +reason demand goes way down you can go + + + align:start position:0% +reason demand goes way down you can go +and park half your taxis and just not + + align:start position:0% +and park half your taxis and just not + + + align:start position:0% +and park half your taxis and just not +operate them you may still have to pay a + + align:start position:0% +operate them you may still have to pay a + + + align:start position:0% +operate them you may still have to pay a +lease on them but essentially you adap + + align:start position:0% +lease on them but essentially you adap + + + align:start position:0% +lease on them but essentially you adap +you can downward adapt the capacity of + + align:start position:0% +you can downward adapt the capacity of + + + align:start position:0% +you can downward adapt the capacity of +VI system you can't do that here it + + align:start position:0% +VI system you can't do that here it + + + align:start position:0% +VI system you can't do that here it +doesn't make sense right so that's the + + align:start position:0% +doesn't make sense right so that's the + + + align:start position:0% +doesn't make sense right so that's the +big difference between systems that are + + align:start position:0% +big difference between systems that are + + + align:start position:0% +big difference between systems that are +fundamentally um fixed costs dominated + + align:start position:0% +fundamentally um fixed costs dominated + + + align:start position:0% +fundamentally um fixed costs dominated +versus variable cost dominated so in + + align:start position:0% +versus variable cost dominated so in + + + align:start position:0% +versus variable cost dominated so in +this case we you know we just don't use + + align:start position:0% +this case we you know we just don't use + + + align:start position:0% +this case we you know we just don't use +it as efficiently in the last six + + align:start position:0% +it as efficiently in the last six + + + align:start position:0% +it as efficiently in the last six +years so the answer here is um the + + align:start position:0% +years so the answer here is um the + + + align:start position:0% +years so the answer here is um the +answer here is that there's an optimal + + align:start position:0% +answer here is that there's an optimal + + + align:start position:0% +answer here is that there's an optimal +path and that's shown here that will um + + align:start position:0% +path and that's shown here that will um + + + align:start position:0% +path and that's shown here that will um +for a given targeted capacity you you + + align:start position:0% +for a given targeted capacity you you + + + align:start position:0% +for a given targeted capacity you you +can then you know you can compare + + align:start position:0% +can then you know you can compare + + + align:start position:0% +can then you know you can compare +essentially this Loop path against the + + align:start position:0% +essentially this Loop path against the + + + align:start position:0% +essentially this Loop path against the +traditional fixed design and in this + + align:start position:0% +traditional fixed design and in this + + + align:start position:0% +traditional fixed design and in this +case you know the traditional + + align:start position:0% +case you know the traditional + + + align:start position:0% +case you know the traditional +architecture fixed architecture would + + align:start position:0% +architecture fixed architecture would + + + align:start position:0% +architecture fixed architecture would +cost about $2 billion to + + align:start position:0% +cost about $2 billion to + + + align:start position:0% +cost about $2 billion to +build and on average the red point is + + align:start position:0% +build and on average the red point is + + + align:start position:0% +build and on average the red point is +the average life cycle cost of the + + align:start position:0% +the average life cycle cost of the + + + align:start position:0% +the average life cycle cost of the +evolvable system is + + align:start position:0% +evolvable system is + + + align:start position:0% +evolvable system is +1.36 Right life cycle cost of the rid + + align:start position:0% +1.36 Right life cycle cost of the rid + + + align:start position:0% +1.36 Right life cycle cost of the rid +design versus the expected life cycle + + align:start position:0% +design versus the expected life cycle + + + align:start position:0% +design versus the expected life cycle +cost of the best best deployment + + align:start position:0% +cost of the best best deployment + + + align:start position:0% +cost of the best best deployment +strategy or stage deployment strategy + + align:start position:0% +strategy or stage deployment strategy + + + align:start position:0% +strategy or stage deployment strategy +which is um essentially the way that's + + align:start position:0% +which is um essentially the way that's + + + align:start position:0% +which is um essentially the way that's +calculated it's the probability weighted + + align:start position:0% +calculated it's the probability weighted + + + align:start position:0% +calculated it's the probability weighted +life cycle cost of each of the scenarios + + align:start position:0% +life cycle cost of each of the scenarios + + + align:start position:0% +life cycle cost of each of the scenarios +right against this path and the + + align:start position:0% +right against this path and the + + + align:start position:0% +right against this path and the +difference between those two numbers is + + align:start position:0% +difference between those two numbers is + + + align:start position:0% +difference between those two numbers is +about a third $650 million and that is + + align:start position:0% +about a third $650 million and that is + + + align:start position:0% +about a third $650 million and that is +the value of the real option that's the + + align:start position:0% +the value of the real option that's the + + + align:start position:0% +the value of the real option that's the +value of Designing the system with + + align:start position:0% +value of Designing the system with + + + align:start position:0% +value of Designing the system with +scalability with + + align:start position:0% +scalability with + + + align:start position:0% +scalability with +flexibility okay yeah + + align:start position:0% + + + + align:start position:0% + +yes uh that's true uh so the lifetime + + align:start position:0% +yes uh that's true uh so the lifetime + + + align:start position:0% +yes uh that's true uh so the lifetime +the question was is the life expectancy + + align:start position:0% +the question was is the life expectancy + + + align:start position:0% +the question was is the life expectancy +similar of course so the 15-year uh life + + align:start position:0% +similar of course so the 15-year uh life + + + align:start position:0% +similar of course so the 15-year uh life +of the whole system isn't is the same + + align:start position:0% +of the whole system isn't is the same + + + align:start position:0% +of the whole system isn't is the same +for both of course in the stage + + align:start position:0% +for both of course in the stage + + + align:start position:0% +for both of course in the stage +deployment strategy um some of the + + align:start position:0% +deployment strategy um some of the + + + align:start position:0% +deployment strategy um some of the +satellites are going to be younger right + + align:start position:0% +satellites are going to be younger right + + + align:start position:0% +satellites are going to be younger right +at the end of the 15 years and so they + + align:start position:0% +at the end of the 15 years and so they + + + align:start position:0% +at the end of the 15 years and so they +may have longer residual life left which + + align:start position:0% +may have longer residual life left which + + + align:start position:0% +may have longer residual life left which +is actually not included that's not even + + align:start position:0% +is actually not included that's not even + + + align:start position:0% +is actually not included that's not even +included in this uh real real option + + align:start position:0% + + + + align:start position:0% + +value + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +y right + + align:start position:0% + + + + align:start position:0% + +that that's right so you could you could + + align:start position:0% +that that's right so you could you could + + + align:start position:0% +that that's right so you could you could +sort ofine this model to include a more + + align:start position:0% +sort ofine this model to include a more + + + align:start position:0% +sort ofine this model to include a more +a stage decommissioning right or stage + + align:start position:0% +a stage decommissioning right or stage + + + align:start position:0% +a stage decommissioning right or stage +transition to a Next Generation system + + align:start position:0% +transition to a Next Generation system + + + align:start position:0% +transition to a Next Generation system +so in this case you know in this model + + align:start position:0% +so in this case you know in this model + + + align:start position:0% +so in this case you know in this model +after 15 years boom you know everything + + align:start position:0% +after 15 years boom you know everything + + + align:start position:0% +after 15 years boom you know everything +you just finish uh no more revenues you + + align:start position:0% +you just finish uh no more revenues you + + + align:start position:0% +you just finish uh no more revenues you +just decommission a hard end a hard stop + + align:start position:0% +just decommission a hard end a hard stop + + + align:start position:0% +just decommission a hard end a hard stop +after 15 years but you could actually + + align:start position:0% +after 15 years but you could actually + + + align:start position:0% +after 15 years but you could actually +build you know transition and de + + align:start position:0% +build you know transition and de + + + align:start position:0% +build you know transition and de +commissioning models as well good point + + align:start position:0% +commissioning models as well good point + + + align:start position:0% +commissioning models as well good point +so so that's that's essentially the the + + align:start position:0% +so so that's that's essentially the the + + + align:start position:0% +so so that's that's essentially the the +case study I wanted to show you and you + + align:start position:0% +case study I wanted to show you and you + + + align:start position:0% +case study I wanted to show you and you +know you'd say oh well that that's a you + + align:start position:0% +know you'd say oh well that that's a you + + + align:start position:0% +know you'd say oh well that that's a you +know that's kind of like uh in in the US + + align:start position:0% +know that's kind of like uh in in the US + + + align:start position:0% +know that's kind of like uh in in the US +we we talk about Monday morning + + align:start position:0% +we we talk about Monday morning + + + align:start position:0% +we we talk about Monday morning +quarterbacking you know you you you + + align:start position:0% +quarterbacking you know you you you + + + align:start position:0% +quarterbacking you know you you you +comment on all the football games that + + align:start position:0% +comment on all the football games that + + + align:start position:0% +comment on all the football games that +happened and the M mistakes that the + + align:start position:0% +happened and the M mistakes that the + + + align:start position:0% +happened and the M mistakes that the +coach has made and I would have done + + align:start position:0% +coach has made and I would have done + + + align:start position:0% +coach has made and I would have done +this or I would have done that so yes + + align:start position:0% +this or I would have done that so yes + + + align:start position:0% +this or I would have done that so yes +you know this is sort of like looking at + + align:start position:0% +you know this is sort of like looking at + + + align:start position:0% +you know this is sort of like looking at +this problem in hindsight but the + + align:start position:0% +this problem in hindsight but the + + + align:start position:0% +this problem in hindsight but the +reality is that that um that uh this + + align:start position:0% +reality is that that um that uh this + + + align:start position:0% +reality is that that um that uh this +really has had a big impact and a big + + align:start position:0% +really has had a big impact and a big + + + align:start position:0% +really has had a big impact and a big +dampening effect and that the the new + + align:start position:0% +dampening effect and that the the new + + + align:start position:0% +dampening effect and that the the new +generation of systems I think are built + + align:start position:0% +generation of systems I think are built + + + align:start position:0% +generation of systems I think are built +much more intelligently you know with + + align:start position:0% +much more intelligently you know with + + + align:start position:0% +much more intelligently you know with +this kind of evolution in mind um I will + + align:start position:0% +this kind of evolution in mind um I will + + + align:start position:0% +this kind of evolution in mind um I will +also mention to you + + align:start position:0% +also mention to you + + + align:start position:0% +also mention to you +that idium is actually the system that + + align:start position:0% +that idium is actually the system that + + + align:start position:0% +that idium is actually the system that +went bankrupt first and the reason for + + align:start position:0% +went bankrupt first and the reason for + + + align:start position:0% +went bankrupt first and the reason for +the bankruptcy well one of the immediate + + align:start position:0% +the bankruptcy well one of the immediate + + + align:start position:0% +the bankruptcy well one of the immediate +reasons for the bankruptcy is because + + align:start position:0% +reasons for the bankruptcy is because + + + align:start position:0% +reasons for the bankruptcy is because +the way that the project was financed so + + align:start position:0% +the way that the project was financed so + + + align:start position:0% +the way that the project was financed so +about onethird of the funds those $5 + + align:start position:0% +about onethird of the funds those $5 + + + align:start position:0% +about onethird of the funds those $5 +billion onethird of the funds for idium + + align:start position:0% +billion onethird of the funds for idium + + + align:start position:0% +billion onethird of the funds for idium +came from um Equity uh from mola so that + + align:start position:0% +came from um Equity uh from mola so that + + + align:start position:0% +came from um Equity uh from mola so that +was their own money that they lost about + + align:start position:0% +was their own money that they lost about + + + align:start position:0% +was their own money that they lost about +onethird was uh IPO initial public + + align:start position:0% +onethird was uh IPO initial public + + + align:start position:0% +onethird was uh IPO initial public +offering you know shares sold to the + + align:start position:0% +offering you know shares sold to the + + + align:start position:0% +offering you know shares sold to the +public and about onethird was bank loans + + align:start position:0% +public and about onethird was bank loans + + + align:start position:0% +public and about onethird was bank loans +and these bank loans were relatively + + align:start position:0% +and these bank loans were relatively + + + align:start position:0% +and these bank loans were relatively +expensive and the banks expect you know + + align:start position:0% +expensive and the banks expect you know + + + align:start position:0% +expensive and the banks expect you know +that they get paid back at a certain + + align:start position:0% +that they get paid back at a certain + + + align:start position:0% +that they get paid back at a certain +speed depending on you know the market + + align:start position:0% +speed depending on you know the market + + + align:start position:0% +speed depending on you know the market +Evolution and and it's essentially the + + align:start position:0% +Evolution and and it's essentially the + + + align:start position:0% +Evolution and and it's essentially the +inability to pay for and service their + + align:start position:0% +inability to pay for and service their + + + align:start position:0% +inability to pay for and service their +loans that caused the aradian bankruptcy + + align:start position:0% +loans that caused the aradian bankruptcy + + + align:start position:0% +loans that caused the aradian bankruptcy +and it turns out that the loans were + + align:start position:0% +and it turns out that the loans were + + + align:start position:0% +and it turns out that the loans were +about onethird of the total + + align:start position:0% +about onethird of the total + + + align:start position:0% +about onethird of the total +capitalization of the project so what I + + align:start position:0% +capitalization of the project so what I + + + align:start position:0% +capitalization of the project so what I +would argue I would argue that if they + + align:start position:0% +would argue I would argue that if they + + + align:start position:0% +would argue I would argue that if they +had done this more flexible staged + + align:start position:0% +had done this more flexible staged + + + align:start position:0% +had done this more flexible staged +approach they could have saved onethird + + align:start position:0% +approach they could have saved onethird + + + align:start position:0% +approach they could have saved onethird +which is about the value of the F option + + align:start position:0% +which is about the value of the F option + + + align:start position:0% +which is about the value of the F option +and capitalization and just built the + + align:start position:0% +and capitalization and just built the + + + align:start position:0% +and capitalization and just built the +system only with equity and with the + + align:start position:0% +system only with equity and with the + + + align:start position:0% +system only with equity and with the +money from the IPO and that would would + + align:start position:0% +money from the IPO and that would would + + + align:start position:0% +money from the IPO and that would would +have given them a lot more time you know + + align:start position:0% +have given them a lot more time you know + + + align:start position:0% +have given them a lot more time you know +they wouldn't have had to service those + + align:start position:0% +they wouldn't have had to service those + + + align:start position:0% +they wouldn't have had to service those +loans and it would have given a lot more + + align:start position:0% +loans and it would have given a lot more + + + align:start position:0% +loans and it would have given a lot more +time to wait for the market to develop + + align:start position:0% +time to wait for the market to develop + + + align:start position:0% +time to wait for the market to develop +which it eventually did um so there was + + align:start position:0% +which it eventually did um so there was + + + align:start position:0% +which it eventually did um so there was +there was the whole financial + + align:start position:0% +there was the whole financial + + + align:start position:0% +there was the whole financial +architecture was poorly done as well + + align:start position:0% +architecture was poorly done as well + + + align:start position:0% +architecture was poorly done as well +which is a whole another that's a whole + + align:start position:0% +which is a whole another that's a whole + + + align:start position:0% +which is a whole another that's a whole +another question uh Professor quick + + align:start position:0% +another question uh Professor quick + + + align:start position:0% +another question uh Professor quick +question there situations where + + align:start position:0% + + + + align:start position:0% + +yes yes uh so the question I'm just + + align:start position:0% +yes yes uh so the question I'm just + + + align:start position:0% +yes yes uh so the question I'm just +going to repeat it for you guys at MIT + + align:start position:0% +going to repeat it for you guys at MIT + + + align:start position:0% +going to repeat it for you guys at MIT +the question was are there are there + + align:start position:0% +the question was are there are there + + + align:start position:0% +the question was are there are there +cases where the flexible approach is not + + align:start position:0% +cases where the flexible approach is not + + + align:start position:0% +cases where the flexible approach is not +the best and the answer is yes so for + + align:start position:0% +the best and the answer is yes so for + + + align:start position:0% +the best and the answer is yes so for +example if you're in you know I know + + align:start position:0% +example if you're in you know I know + + + align:start position:0% +example if you're in you know I know +that you you're starting the energy + + align:start position:0% +that you you're starting the energy + + + align:start position:0% +that you you're starting the energy +energy markets if you're in a situation + + align:start position:0% +energy markets if you're in a situation + + + align:start position:0% +energy markets if you're in a situation +where you have guaranteed + + align:start position:0% +where you have guaranteed + + + align:start position:0% +where you have guaranteed +a guaranteed customer you know so the + + align:start position:0% +a guaranteed customer you know so the + + + align:start position:0% +a guaranteed customer you know so the +the government or one of the big + + align:start position:0% +the government or one of the big + + + align:start position:0% +the government or one of the big +utilities is entering into a long-term + + align:start position:0% +utilities is entering into a long-term + + + align:start position:0% +utilities is entering into a long-term +agreement with you that they will buy + + align:start position:0% +agreement with you that they will buy + + + align:start position:0% +agreement with you that they will buy +the power that you produce at a certain + + align:start position:0% +the power that you produce at a certain + + + align:start position:0% +the power that you produce at a certain +price for the next 20 years right um and + + align:start position:0% +price for the next 20 years right um and + + + align:start position:0% +price for the next 20 years right um and +so you're not subject to that market + + align:start position:0% +so you're not subject to that market + + + align:start position:0% +so you're not subject to that market +volatility but you have a long-term + + align:start position:0% +volatility but you have a long-term + + + align:start position:0% +volatility but you have a long-term +agreement including Clauses that say + + align:start position:0% +agreement including Clauses that say + + + align:start position:0% +agreement including Clauses that say +well if if the government doesn't do + + align:start position:0% +well if if the government doesn't do + + + align:start position:0% +well if if the government doesn't do +this then they'll they'll compensate you + + align:start position:0% +this then they'll they'll compensate you + + + align:start position:0% +this then they'll they'll compensate you +for any losses you know this is the + + align:start position:0% +for any losses you know this is the + + + align:start position:0% +for any losses you know this is the +financial AR contraction if you + + align:start position:0% +financial AR contraction if you + + + align:start position:0% +financial AR contraction if you +basically have eliminated demand + + align:start position:0% +basically have eliminated demand + + + align:start position:0% +basically have eliminated demand +uncertainty because of the particular + + align:start position:0% +uncertainty because of the particular + + + align:start position:0% +uncertainty because of the particular +contractual Arrangement then there's no + + align:start position:0% +contractual Arrangement then there's no + + + align:start position:0% +contractual Arrangement then there's no +reason you shouldn't build the system + + align:start position:0% +reason you shouldn't build the system + + + align:start position:0% +reason you shouldn't build the system +for a fixed capacity and + + align:start position:0% +for a fixed capacity and + + + align:start position:0% +for a fixed capacity and +um because you're then you can build + + align:start position:0% +um because you're then you can build + + + align:start position:0% +um because you're then you can build +something right on the Pito front + + align:start position:0% +something right on the Pito front + + + align:start position:0% +something right on the Pito front +because that particular uncertainty has + + align:start position:0% +because that particular uncertainty has + + + align:start position:0% +because that particular uncertainty has +been eliminated for for policy or + + align:start position:0% +been eliminated for for policy or + + + align:start position:0% +been eliminated for for policy or +contractual re reasons so good + + align:start position:0% +contractual re reasons so good + + + align:start position:0% +contractual re reasons so good +question okay um so we're almost almost + + align:start position:0% +question okay um so we're almost almost + + + align:start position:0% +question okay um so we're almost almost +there let me just try to uh summarize + + align:start position:0% +there let me just try to uh summarize + + + align:start position:0% +there let me just try to uh summarize +some of + + align:start position:0% + + + + align:start position:0% + +the please go ahead um on the side + + align:start position:0% +the please go ahead um on the side + + + align:start position:0% +the please go ahead um on the side +before 37 um it seemed like um the + + align:start position:0% +before 37 um it seemed like um the + + + align:start position:0% +before 37 um it seemed like um the +probability waiting was for um kind of a + + align:start position:0% +probability waiting was for um kind of a + + + align:start position:0% +probability waiting was for um kind of a +a general capacity like uh something + + align:start position:0% +a general capacity like uh something + + + align:start position:0% +a general capacity like uh something +that could be adapted over the life + + align:start position:0% +that could be adapted over the life + + + align:start position:0% +that could be adapted over the life +cycle but here we're we're pinning down + + align:start position:0% +cycle but here we're we're pinning down + + + align:start position:0% +cycle but here we're we're pinning down +a a specific capacity so why is it the + + align:start position:0% +a a specific capacity so why is it the + + + align:start position:0% +a a specific capacity so why is it the +sum of probabilities then haven't kind + + align:start position:0% +sum of probabilities then haven't kind + + + align:start position:0% +sum of probabilities then haven't kind +of the probabilities been realized don't + + align:start position:0% +of the probabilities been realized don't + + + align:start position:0% +of the probabilities been realized don't +you know exactly what Your Capacity is + + align:start position:0% +you know exactly what Your Capacity is + + + align:start position:0% +you know exactly what Your Capacity is +that you're operating + + align:start position:0% +that you're operating + + + align:start position:0% +that you're operating +at yeah so so just to be clear on this + + align:start position:0% +at yeah so so just to be clear on this + + + align:start position:0% +at yeah so so just to be clear on this +so the probabilities those P subi + + align:start position:0% +so the probabilities those P subi + + + align:start position:0% +so the probabilities those P subi +they're they come from the lattice model + + align:start position:0% +they're they come from the lattice model + + + align:start position:0% +they're they come from the lattice model +they are determined by the lattice model + + align:start position:0% +they are determined by the lattice model + + + align:start position:0% +they are determined by the lattice model +so what you do is for those 32 scenarios + + align:start position:0% +so what you do is for those 32 scenarios + + + align:start position:0% +so what you do is for those 32 scenarios +of the future this is the pi right the I + + align:start position:0% +of the future this is the pi right the I + + + align:start position:0% +of the future this is the pi right the I +is the index is the is the uh for this + + align:start position:0% +is the index is the is the uh for this + + + align:start position:0% +is the index is the is the uh for this +particular future scenario for each + + align:start position:0% +particular future scenario for each + + + align:start position:0% +particular future scenario for each +future scenario you start with your you + + align:start position:0% +future scenario you start with your you + + + align:start position:0% +future scenario you start with your you +always start with A1 which is your + + align:start position:0% +always start with A1 which is your + + + align:start position:0% +always start with A1 which is your +initial configuration right of the + + align:start position:0% +initial configuration right of the + + + align:start position:0% +initial configuration right of the +constellation you always start with + + align:start position:0% +constellation you always start with + + + align:start position:0% +constellation you always start with +A1 and for each of those future + + align:start position:0% +A1 and for each of those future + + + align:start position:0% +A1 and for each of those future +scenarios you then simulate that future + + align:start position:0% +scenarios you then simulate that future + + + align:start position:0% +scenarios you then simulate that future +and you know if you know for those + + align:start position:0% +and you know if you know for those + + + align:start position:0% +and you know if you know for those +Futures where the demand does never + + align:start position:0% +Futures where the demand does never + + + align:start position:0% +Futures where the demand does never +really takes off and materializes you + + align:start position:0% +really takes off and materializes you + + + align:start position:0% +really takes off and materializes you +never actually trigger that next + + align:start position:0% +never actually trigger that next + + + align:start position:0% +never actually trigger that next +expansion stage and it's actually that + + align:start position:0% +expansion stage and it's actually that + + + align:start position:0% +expansion stage and it's actually that +asymmetry that gives you the advantage + + align:start position:0% +asymmetry that gives you the advantage + + + align:start position:0% +asymmetry that gives you the advantage +and um it's essentially not the + + align:start position:0% +and um it's essentially not the + + + align:start position:0% +and um it's essentially not the +deploying capacity when you really don't + + align:start position:0% +deploying capacity when you really don't + + + align:start position:0% +deploying capacity when you really don't +need it and um and so you do this for + + align:start position:0% +need it and um and so you do this for + + + align:start position:0% +need it and um and so you do this for +all of the end scenarios of the future + + align:start position:0% +all of the end scenarios of the future + + + align:start position:0% +all of the end scenarios of the future +and the pi is the probability waiting of + + align:start position:0% +and the pi is the probability waiting of + + + align:start position:0% +and the pi is the probability waiting of +each future scenario comes directly out + + align:start position:0% +each future scenario comes directly out + + + align:start position:0% +each future scenario comes directly out +of the lattice model that's not + + align:start position:0% +of the lattice model that's not + + + align:start position:0% +of the lattice model that's not +something that you have to manually + + align:start position:0% +something that you have to manually + + + align:start position:0% +something that you have to manually +determine right no I I understand that + + align:start position:0% +determine right no I I understand that + + + align:start position:0% +determine right no I I understand that +but here since we've kind of pinned down + + align:start position:0% +but here since we've kind of pinned down + + + align:start position:0% +but here since we've kind of pinned down +a capacity already we know what endpoint + + align:start position:0% +a capacity already we know what endpoint + + + align:start position:0% +a capacity already we know what endpoint +we're at I'm just wondering how the how + + align:start position:0% +we're at I'm just wondering how the how + + + align:start position:0% +we're at I'm just wondering how the how +the probabilities come into that or is + + align:start position:0% +the probabilities come into that or is + + + align:start position:0% +the probabilities come into that or is +it kind of working backwards now of all + + align:start position:0% +it kind of working backwards now of all + + + align:start position:0% +it kind of working backwards now of all +the out there on this specific + + align:start position:0% +the out there on this specific + + + align:start position:0% +the out there on this specific +plot I see what you're saying okay so + + align:start position:0% +plot I see what you're saying okay so + + + align:start position:0% +plot I see what you're saying okay so +the the left point the A1 point so the + + align:start position:0% +the the left point the A1 point so the + + + align:start position:0% +the the left point the A1 point so the +A1 point is driven by you need you need + + align:start position:0% +A1 point is driven by you need you need + + + align:start position:0% +A1 point is driven by you need you need +to make some assumptions about initial + + align:start position:0% +to make some assumptions about initial + + + align:start position:0% +to make some assumptions about initial +capacity and and then the end point the + + align:start position:0% +capacity and and then the end point the + + + align:start position:0% +capacity and and then the end point the +A4 is driven by how large you made the + + align:start position:0% +A4 is driven by how large you made the + + + align:start position:0% +A4 is driven by how large you made the +trade + + align:start position:0% +trade + + + align:start position:0% +trade +space so you if you could make the trade + + align:start position:0% +space so you if you could make the trade + + + align:start position:0% +space so you if you could make the trade +space you could make the design space + + align:start position:0% +space you could make the design space + + + align:start position:0% +space you could make the design space +even larger right this is a discretized + + align:start position:0% +even larger right this is a discretized + + + align:start position:0% +even larger right this is a discretized +uh full factorial design space you could + + align:start position:0% +uh full factorial design space you could + + + align:start position:0% +uh full factorial design space you could +make it even larger and then A4 would + + align:start position:0% +make it even larger and then A4 would + + + align:start position:0% +make it even larger and then A4 would +not be the end point this is just sort + + align:start position:0% +not be the end point this is just sort + + + align:start position:0% +not be the end point this is just sort +of a finite size effect due to the size + + align:start position:0% +of a finite size effect due to the size + + + align:start position:0% +of a finite size effect due to the size +of the trade + + align:start position:0% +of the trade + + + align:start position:0% +of the trade +space okay + + align:start position:0% +space okay + + + align:start position:0% +space okay +thanks + + align:start position:0% +thanks + + + align:start position:0% +thanks +okay all right so let me um let's go to + + align:start position:0% +okay all right so let me um let's go to + + + align:start position:0% +okay all right so let me um let's go to +the you know so the way I want to do the + + align:start position:0% +the you know so the way I want to do the + + + align:start position:0% +the you know so the way I want to do the +summary here is just go back to the + + align:start position:0% +summary here is just go back to the + + + align:start position:0% +summary here is just go back to the +learning objectives you know I always do + + align:start position:0% +learning objectives you know I always do + + + align:start position:0% +learning objectives you know I always do +this in every class you know let's close + + align:start position:0% +this in every class you know let's close + + + align:start position:0% +this in every class you know let's close +the loop what did I + + align:start position:0% +the loop what did I + + + align:start position:0% +the loop what did I +promise you in lecture one that you + + align:start position:0% +promise you in lecture one that you + + + align:start position:0% +promise you in lecture one that you +would learn in this class and you know + + align:start position:0% +would learn in this class and you know + + + align:start position:0% +would learn in this class and you know +each of you you're going to have to + + align:start position:0% +each of you you're going to have to + + + align:start position:0% +each of you you're going to have to +decide for yourself you know did I + + align:start position:0% +decide for yourself you know did I + + + align:start position:0% +decide for yourself you know did I +actually learn this did did we actually + + align:start position:0% +actually learn this did did we actually + + + align:start position:0% +actually learn this did did we actually +do this so this is sort of due diligence + + align:start position:0% +do this so this is sort of due diligence + + + align:start position:0% +do this so this is sort of due diligence +on the learning objectives and I have + + align:start position:0% +on the learning objectives and I have + + + align:start position:0% +on the learning objectives and I have +one slide on each of them so the first + + align:start position:0% +one slide on each of them so the first + + + align:start position:0% +one slide on each of them so the first +objective was to for you to really + + align:start position:0% +objective was to for you to really + + + align:start position:0% +objective was to for you to really +understand the system engineering + + align:start position:0% +understand the system engineering + + + align:start position:0% +understand the system engineering +standards and best practices as well as + + align:start position:0% +standards and best practices as well as + + + align:start position:0% +standards and best practices as well as +newer + + align:start position:0% +newer + + + align:start position:0% +newer +approaches number two is understand the + + align:start position:0% +approaches number two is understand the + + + align:start position:0% +approaches number two is understand the +key steps in the system Engineering + + align:start position:0% +key steps in the system Engineering + + + align:start position:0% +key steps in the system Engineering +Process number three was uh analyze and + + align:start position:0% +Process number three was uh analyze and + + + align:start position:0% +Process number three was uh analyze and +understand the role of humans in in the + + align:start position:0% +understand the role of humans in in the + + + align:start position:0% +understand the role of humans in in the +system as beneficiaries designers + + align:start position:0% +system as beneficiaries designers + + + align:start position:0% +system as beneficiaries designers +operators and so forth number four was + + align:start position:0% +operators and so forth number four was + + + align:start position:0% +operators and so forth number four was +um being honest and characterizing the + + align:start position:0% +um being honest and characterizing the + + + align:start position:0% +um being honest and characterizing the +limitations of system engineering as we + + align:start position:0% +limitations of system engineering as we + + + align:start position:0% +limitations of system engineering as we +as we practice it today and then uh + + align:start position:0% +as we practice it today and then uh + + + align:start position:0% +as we practice it today and then uh +objective five learning objective five + + align:start position:0% +objective five learning objective five + + + align:start position:0% +objective five learning objective five +was applying these methods and tools to + + align:start position:0% +was applying these methods and tools to + + + align:start position:0% +was applying these methods and tools to +a real even as not so complex cyber + + align:start position:0% +a real even as not so complex cyber + + + align:start position:0% +a real even as not so complex cyber +electromechanical system + + align:start position:0% +electromechanical system + + + align:start position:0% +electromechanical system +so uh + + align:start position:0% +so uh + + + align:start position:0% +so uh +se1 um essentially hopefully know we we + + align:start position:0% +se1 um essentially hopefully know we we + + + align:start position:0% +se1 um essentially hopefully know we we +didn't check the readings but I'm I'm + + align:start position:0% +didn't check the readings but I'm I'm + + + align:start position:0% +didn't check the readings but I'm I'm +hoping that you did your readings that + + align:start position:0% +hoping that you did your readings that + + + align:start position:0% +hoping that you did your readings that +you really feel like you understand the + + align:start position:0% +you really feel like you understand the + + + align:start position:0% +you really feel like you understand the +NASA system engineering handbook which + + align:start position:0% +NASA system engineering handbook which + + + align:start position:0% +NASA system engineering handbook which +is our our quasi textbook for this class + + align:start position:0% +is our our quasi textbook for this class + + + align:start position:0% +is our our quasi textbook for this class +but there's other uh other standards as + + align:start position:0% +but there's other uh other standards as + + + align:start position:0% +but there's other uh other standards as +well such as the enclos St the enclos + + align:start position:0% +well such as the enclos St the enclos + + + align:start position:0% +well such as the enclos St the enclos +handbook which is actually the basis for + + align:start position:0% +handbook which is actually the basis for + + + align:start position:0% +handbook which is actually the basis for +uh certification so several of you here + + align:start position:0% +uh certification so several of you here + + + align:start position:0% +uh certification so several of you here +at epfl mentioned to me that you're + + align:start position:0% +at epfl mentioned to me that you're + + + align:start position:0% +at epfl mentioned to me that you're +interested and certification so I I + + align:start position:0% +interested and certification so I I + + + align:start position:0% +interested and certification so I I +encourage that most of that is based on + + align:start position:0% +encourage that most of that is based on + + + align:start position:0% +encourage that most of that is based on +the on this uh number two uh I did + + align:start position:0% +the on this uh number two uh I did + + + align:start position:0% +the on this uh number two uh I did +mention the iso standard 15288 that's + + align:start position:0% +mention the iso standard 15288 that's + + + align:start position:0% +mention the iso standard 15288 that's +probably the best known standard you + + align:start position:0% +probably the best known standard you + + + align:start position:0% +probably the best known standard you +know ISO is a very located right here in + + align:start position:0% +know ISO is a very located right here in + + + align:start position:0% +know ISO is a very located right here in +Geneva ISO is a very important + + align:start position:0% +Geneva ISO is a very important + + + align:start position:0% +Geneva ISO is a very important +organization you know I know ISO + + align:start position:0% +organization you know I know ISO + + + align:start position:0% +organization you know I know ISO +standards are not the most exciting + + align:start position:0% +standards are not the most exciting + + + align:start position:0% +standards are not the most exciting +things to read but they have huge impact + + align:start position:0% +things to read but they have huge impact + + + align:start position:0% +things to read but they have huge impact +um and so 15288 is is is something + + align:start position:0% +um and so 15288 is is is something + + + align:start position:0% +um and so 15288 is is is something +that's well worldwide known and and + + align:start position:0% +that's well worldwide known and and + + + align:start position:0% +that's well worldwide known and and +across all all Industries really and + + align:start position:0% +across all all Industries really and + + + align:start position:0% +across all all Industries really and +then um I want to mention also the + + align:start position:0% +then um I want to mention also the + + + align:start position:0% +then um I want to mention also the +European systems engineering standard + + align:start position:0% +European systems engineering standard + + + align:start position:0% +European systems engineering standard +and fulker and I had a discussion about + + align:start position:0% +and fulker and I had a discussion about + + + align:start position:0% +and fulker and I had a discussion about +this earlier today uh this is uh issued + + align:start position:0% +this earlier today uh this is uh issued + + + align:start position:0% +this earlier today uh this is uh issued +by the U European space agency and it is + + align:start position:0% +by the U European space agency and it is + + + align:start position:0% +by the U European space agency and it is +a little there's some subtle differences + + align:start position:0% +a little there's some subtle differences + + + align:start position:0% +a little there's some subtle differences +between the ISA approach and the NASA + + align:start position:0% +between the ISA approach and the NASA + + + align:start position:0% +between the ISA approach and the NASA +approach and so for those of you on this + + align:start position:0% +approach and so for those of you on this + + + align:start position:0% +approach and so for those of you on this +side of the Atlantic uh I do encourage + + align:start position:0% +side of the Atlantic uh I do encourage + + + align:start position:0% +side of the Atlantic uh I do encourage +you to take a look at that ecss standard + + align:start position:0% +you to take a look at that ecss standard + + + align:start position:0% +you to take a look at that ecss standard +as well and then we we augmented this + + align:start position:0% +as well and then we we augmented this + + + align:start position:0% +as well and then we we augmented this +with you know different uh papers and + + align:start position:0% +with you know different uh papers and + + + align:start position:0% +with you know different uh papers and +readings and so forth so I want to do a + + align:start position:0% +readings and so forth so I want to do a + + + align:start position:0% +readings and so forth so I want to do a +very quick um this is our last concept + + align:start position:0% +very quick um this is our last concept + + + align:start position:0% +very quick um this is our last concept +question for the class so uh here's the + + align:start position:0% +question for the class so uh here's the + + + align:start position:0% +question for the class so uh here's the +link uh + + align:start position:0% + + + + align:start position:0% + +tiny.cc Capital SE standards and it's + + align:start position:0% +tiny.cc Capital SE standards and it's + + + align:start position:0% +tiny.cc Capital SE standards and it's +essentially uh I want to get some + + align:start position:0% +essentially uh I want to get some + + + align:start position:0% +essentially uh I want to get some +feedback uh what you think about these + + align:start position:0% +feedback uh what you think about these + + + align:start position:0% +feedback uh what you think about these +standards all outdated and surpassed by + + align:start position:0% +standards all outdated and surpassed by + + + align:start position:0% +standards all outdated and surpassed by +the digital Revolution one of you think + + align:start position:0% +the digital Revolution one of you think + + + align:start position:0% +the digital Revolution one of you think +that thinks that's true uh 90% of you + + align:start position:0% +that thinks that's true uh 90% of you + + + align:start position:0% +that thinks that's true uh 90% of you +think they're still they're useful + + align:start position:0% +think they're still they're useful + + + align:start position:0% +think they're still they're useful +codification of best + + align:start position:0% +codification of best + + + align:start position:0% +codification of best +practice um 15 14% think they can be + + align:start position:0% +practice um 15 14% think they can be + + + align:start position:0% +practice um 15 14% think they can be +dangerous if you adhere to them too + + align:start position:0% +dangerous if you adhere to them too + + + align:start position:0% +dangerous if you adhere to them too +closely um about 60% of you think + + align:start position:0% +closely um about 60% of you think + + + align:start position:0% +closely um about 60% of you think +they're essential reading for any + + align:start position:0% +they're essential reading for any + + + align:start position:0% +they're essential reading for any +serious system engineer and uh 3 10% + + align:start position:0% +serious system engineer and uh 3 10% + + + align:start position:0% +serious system engineer and uh 3 10% +said you would never use them as a daily + + align:start position:0% +said you would never use them as a daily + + + align:start position:0% +said you would never use them as a daily +reference book okay so that's that's + + align:start position:0% +reference book okay so that's that's + + + align:start position:0% +reference book okay so that's that's +good I think that's what do you think + + align:start position:0% +good I think that's what do you think + + + align:start position:0% +good I think that's what do you think +buker that's a pretty reasonable outcome + + align:start position:0% +buker that's a pretty reasonable outcome + + + align:start position:0% +buker that's a pretty reasonable outcome +you think okay but what is true is uh + + align:start position:0% +you think okay but what is true is uh + + + align:start position:0% +you think okay but what is true is uh +they're going to be referenced in + + align:start position:0% +they're going to be referenced in + + + align:start position:0% +they're going to be referenced in +contracts you know if you're if you're + + align:start position:0% +contracts you know if you're if you're + + + align:start position:0% +contracts you know if you're if you're +um if you're doing you know it depends + + align:start position:0% +um if you're doing you know it depends + + + align:start position:0% +um if you're doing you know it depends +again on on the industry that you're in + + align:start position:0% +again on on the industry that you're in + + + align:start position:0% +again on on the industry that you're in +but um you know you you're going to + + align:start position:0% +but um you know you you're going to + + + align:start position:0% +but um you know you you're going to +adhere to some of these things in + + align:start position:0% +adhere to some of these things in + + + align:start position:0% +adhere to some of these things in +contracts and if things don't go well + + align:start position:0% +contracts and if things don't go well + + + align:start position:0% +contracts and if things don't go well +people will actually check whether uh + + align:start position:0% +people will actually check whether uh + + + align:start position:0% +people will actually check whether uh +did you do this step did you do that + + align:start position:0% +did you do this step did you do that + + + align:start position:0% +did you do this step did you do that +step um so it does have you know real + + align:start position:0% +step um so it does have you know real + + + align:start position:0% +step um so it does have you know real +consequences okay great thank you very + + align:start position:0% +consequences okay great thank you very + + + align:start position:0% +consequences okay great thank you very +much that was that was good um step two + + align:start position:0% +much that was that was good um step two + + + align:start position:0% +much that was that was good um step two +you know the key steps the V model I + + align:start position:0% +you know the key steps the V model I + + + align:start position:0% +you know the key steps the V model I +think I'm not going to explain it again + + align:start position:0% +think I'm not going to explain it again + + + align:start position:0% +think I'm not going to explain it again +you know hopefully this is something + + align:start position:0% +you know hopefully this is something + + + align:start position:0% +you know hopefully this is something +that you will not forget and just one + + align:start position:0% +that you will not forget and just one + + + align:start position:0% +that you will not forget and just one +one point about the V model is you know + + align:start position:0% +one point about the V model is you know + + + align:start position:0% +one point about the V model is you know +it does not imply that that system + + align:start position:0% +it does not imply that that system + + + align:start position:0% +it does not imply that that system +engineering is always sequential you + + align:start position:0% +engineering is always sequential you + + + align:start position:0% +engineering is always sequential you +know there's it's possible to iterate + + align:start position:0% +know there's it's possible to iterate + + + align:start position:0% +know there's it's possible to iterate +between steps and across the whole v as + + align:start position:0% +between steps and across the whole v as + + + align:start position:0% +between steps and across the whole v as +well um se3 stakeholders and value + + align:start position:0% +well um se3 stakeholders and value + + + align:start position:0% +well um se3 stakeholders and value +Network so this is the uh the role of + + align:start position:0% +Network so this is the uh the role of + + + align:start position:0% +Network so this is the uh the role of +humans uh we talked about this very + + align:start position:0% +humans uh we talked about this very + + + align:start position:0% +humans uh we talked about this very +early on uh several of you talked about + + align:start position:0% +early on uh several of you talked about + + + align:start position:0% +early on uh several of you talked about +it during the oral exams here today you + + align:start position:0% +it during the oral exams here today you + + + align:start position:0% +it during the oral exams here today you +know the Hub and spoke versus the um the + + align:start position:0% +know the Hub and spoke versus the um the + + + align:start position:0% +know the Hub and spoke versus the um the +stakeholder value Network the method + + align:start position:0% +stakeholder value Network the method + + + align:start position:0% +stakeholder value Network the method +underlying this is critical but I do + + align:start position:0% +underlying this is critical but I do + + + align:start position:0% +underlying this is critical but I do +want to mention uh very quickly and this + + align:start position:0% +want to mention uh very quickly and this + + + align:start position:0% +want to mention uh very quickly and this +is something we didn't spend a lot of + + align:start position:0% +is something we didn't spend a lot of + + + align:start position:0% +is something we didn't spend a lot of +time on as human factors right how + + align:start position:0% +time on as human factors right how + + + align:start position:0% +time on as human factors right how +Design Systems so that humans can + + align:start position:0% +Design Systems so that humans can + + + align:start position:0% +Design Systems so that humans can +effectively and safely use them you know + + align:start position:0% +effectively and safely use them you know + + + align:start position:0% +effectively and safely use them you know +interfaces + + align:start position:0% +interfaces + + + align:start position:0% +interfaces +procedures um and and so this is a + + align:start position:0% +procedures um and and so this is a + + + align:start position:0% +procedures um and and so this is a +couple slides from one of my colleagues + + align:start position:0% +couple slides from one of my colleagues + + + align:start position:0% +couple slides from one of my colleagues +Missy Cummings this is actually some uh + + align:start position:0% +Missy Cummings this is actually some uh + + + align:start position:0% +Missy Cummings this is actually some uh +in a nuclear plant Kata you're going to + + align:start position:0% +in a nuclear plant Kata you're going to + + + align:start position:0% +in a nuclear plant Kata you're going to +like this uh lots of these dials and + + align:start position:0% +like this uh lots of these dials and + + + align:start position:0% +like this uh lots of these dials and +this is actually a Russian nuclear plant + + align:start position:0% +this is actually a Russian nuclear plant + + + align:start position:0% +this is actually a Russian nuclear plant +so it has it has a very uh specific + + align:start position:0% +so it has it has a very uh specific + + + align:start position:0% +so it has it has a very uh specific +layout and so the important questions in + + align:start position:0% +layout and so the important questions in + + + align:start position:0% +layout and so the important questions in +human factors are how do you best + + align:start position:0% +human factors are how do you best + + + align:start position:0% +human factors are how do you best +display status information what tasks do + + align:start position:0% +display status information what tasks do + + + align:start position:0% +display status information what tasks do +humans do what tasks what level of + + align:start position:0% +humans do what tasks what level of + + + align:start position:0% +humans do what tasks what level of +automation what are the training + + align:start position:0% +automation what are the training + + + align:start position:0% +automation what are the training +requirements and this is these are also + + align:start position:0% +requirements and this is these are also + + + align:start position:0% +requirements and this is these are also +very important questions and so you can + + align:start position:0% +very important questions and so you can + + + align:start position:0% +very important questions and so you can +apply you know the human systems + + align:start position:0% +apply you know the human systems + + + align:start position:0% +apply you know the human systems +Engineering Process very much uh anal + + align:start position:0% +Engineering Process very much uh anal + + + align:start position:0% +Engineering Process very much uh anal +analogous to what we covered in class so + + align:start position:0% +analogous to what we covered in class so + + + align:start position:0% +analogous to what we covered in class so +far so you do Mission and scenario + + align:start position:0% +far so you do Mission and scenario + + + align:start position:0% +far so you do Mission and scenario +analysis function function allocation + + align:start position:0% +analysis function function allocation + + + align:start position:0% +analysis function function allocation +and then in human factors you talk more + + align:start position:0% +and then in human factors you talk more + + + align:start position:0% +and then in human factors you talk more +about task analysis but essentially + + align:start position:0% +about task analysis but essentially + + + align:start position:0% +about task analysis but essentially +eventually leaves to leads to system + + align:start position:0% +eventually leaves to leads to system + + + align:start position:0% +eventually leaves to leads to system +design like what is the you know what + + align:start position:0% +design like what is the you know what + + + align:start position:0% +design like what is the you know what +are the buttons that you push what does + + align:start position:0% +are the buttons that you push what does + + + align:start position:0% +are the buttons that you push what does +the the layout uh look like or the user + + align:start position:0% +the the layout uh look like or the user + + + align:start position:0% +the the layout uh look like or the user +interface and so forth so you know I'm + + align:start position:0% +interface and so forth so you know I'm + + + align:start position:0% +interface and so forth so you know I'm +not I'm not presenting human factors as + + align:start position:0% +not I'm not presenting human factors as + + + align:start position:0% +not I'm not presenting human factors as +a separate topic but it the human + + align:start position:0% +a separate topic but it the human + + + align:start position:0% +a separate topic but it the human +factors requirements should be built in + + align:start position:0% +factors requirements should be built in + + + align:start position:0% +factors requirements should be built in +right from the + + align:start position:0% +right from the + + + align:start position:0% +right from the +start and uh essentially functional + + align:start position:0% +start and uh essentially functional + + + align:start position:0% +start and uh essentially functional +allocation is sort of the key question + + align:start position:0% +allocation is sort of the key question + + + align:start position:0% +allocation is sort of the key question +here how much is done by automation how + + align:start position:0% +here how much is done by automation how + + + align:start position:0% +here how much is done by automation how +much is done by humans and how do you + + align:start position:0% +much is done by humans and how do you + + + align:start position:0% +much is done by humans and how do you +split between the two and one of the + + align:start position:0% +split between the two and one of the + + + align:start position:0% +split between the two and one of the +most important things to consider here + + align:start position:0% +most important things to consider here + + + align:start position:0% +most important things to consider here +is this Human Performance curve and and + + align:start position:0% +is this Human Performance curve and and + + + align:start position:0% +is this Human Performance curve and and +we know this pretty well now that when + + align:start position:0% +we know this pretty well now that when + + + align:start position:0% +we know this pretty well now that when +humans are extremely highly loaded you + + align:start position:0% +humans are extremely highly loaded you + + + align:start position:0% +humans are extremely highly loaded you +know you have a huge uh workload you + + align:start position:0% +know you have a huge uh workload you + + + align:start position:0% +know you have a huge uh workload you +your performance goes down but + + align:start position:0% +your performance goes down but + + + align:start position:0% +your performance goes down but +interestingly if you're if you're under + + align:start position:0% +interestingly if you're if you're under + + + align:start position:0% +interestingly if you're if you're under +challenged your performance goes down as + + align:start position:0% +challenged your performance goes down as + + + align:start position:0% +challenged your performance goes down as +well and you know so for example people + + align:start position:0% +well and you know so for example people + + + align:start position:0% +well and you know so for example people +that are in power stations or you know + + align:start position:0% +that are in power stations or you know + + + align:start position:0% +that are in power stations or you know +mission control centers where nothing is + + align:start position:0% +mission control centers where nothing is + + + align:start position:0% +mission control centers where nothing is +happening for days and weeks you know + + align:start position:0% +happening for days and weeks you know + + + align:start position:0% +happening for days and weeks you know +they their attention goes down and they + + align:start position:0% +they their attention goes down and they + + + align:start position:0% +they their attention goes down and they +don't perform at their high level humans + + align:start position:0% +don't perform at their high level humans + + + align:start position:0% +don't perform at their high level humans +perform best at a moderate workload and + + align:start position:0% +perform best at a moderate workload and + + + align:start position:0% +perform best at a moderate workload and +and this is well known and it should + + align:start position:0% +and this is well known and it should + + + align:start position:0% +and this is well known and it should +influence how you design the human + + align:start position:0% +influence how you design the human + + + align:start position:0% +influence how you design the human +interface and the split among Automation + + align:start position:0% +interface and the split among Automation + + + align:start position:0% +interface and the split among Automation +and humans um se4 system complexity last + + align:start position:0% +and humans um se4 system complexity last + + + align:start position:0% +and humans um se4 system complexity last +time I will mention the magic number + + align:start position:0% +time I will mention the magic number + + + align:start position:0% +time I will mention the magic number +seven plus or minus two the the real + + align:start position:0% +seven plus or minus two the the real + + + align:start position:0% +seven plus or minus two the the real +limitations come in when we operate at + + align:start position:0% +limitations come in when we operate at + + + align:start position:0% +limitations come in when we operate at +levels you know three four five and six + + align:start position:0% +levels you know three four five and six + + + align:start position:0% +levels you know three four five and six +and the main reason for this is because + + align:start position:0% +and the main reason for this is because + + + align:start position:0% +and the main reason for this is because +now a single human cannot understand + + align:start position:0% +now a single human cannot understand + + + align:start position:0% +now a single human cannot understand +cannot remember cannot deal with all the + + align:start position:0% +cannot remember cannot deal with all the + + + align:start position:0% +cannot remember cannot deal with all the +detailed components and you need to + + align:start position:0% +detailed components and you need to + + + align:start position:0% +detailed components and you need to +split the work among teams among organiz + + align:start position:0% +split the work among teams among organiz + + + align:start position:0% +split the work among teams among organiz +ganizations and that creates extra + + align:start position:0% +ganizations and that creates extra + + + align:start position:0% +ganizations and that creates extra +interfaces and + + align:start position:0% +interfaces and + + + align:start position:0% +interfaces and +complexities okay and just to show you + + align:start position:0% +complexities okay and just to show you + + + align:start position:0% +complexities okay and just to show you +you know iridium we talked about iridium + + align:start position:0% +you know iridium we talked about iridium + + + align:start position:0% +you know iridium we talked about iridium +this is a very recent news story this is + + align:start position:0% +this is a very recent news story this is + + + align:start position:0% +this is a very recent news story this is +from October 29th the new iridium next + + align:start position:0% +from October 29th the new iridium next + + + align:start position:0% +from October 29th the new iridium next +has again been pushed back by four + + align:start position:0% +has again been pushed back by four + + + align:start position:0% +has again been pushed back by four +months uh this gentleman here is the uh + + align:start position:0% +months uh this gentleman here is the uh + + + align:start position:0% +months uh this gentleman here is the uh +CEO of the Iridium chief executive for + + align:start position:0% +CEO of the Iridium chief executive for + + + align:start position:0% +CEO of the Iridium chief executive for +iridium next Mr Dash and you know he's + + align:start position:0% +iridium next Mr Dash and you know he's + + + align:start position:0% +iridium next Mr Dash and you know he's +talking here about a particular + + align:start position:0% +talking here about a particular + + + align:start position:0% +talking here about a particular +particular Talis alenia and then ViaSat + + align:start position:0% +particular Talis alenia and then ViaSat + + + align:start position:0% +particular Talis alenia and then ViaSat +is one of the contractors there's a + + align:start position:0% +is one of the contractors there's a + + + align:start position:0% +is one of the contractors there's a +particular component that's been giving + + align:start position:0% +particular component that's been giving + + + align:start position:0% +particular component that's been giving +trouble uh and that's sort of in level + + align:start position:0% +trouble uh and that's sort of in level + + + align:start position:0% +trouble uh and that's sort of in level +three or four in the in the hierarchy + + align:start position:0% +three or four in the in the hierarchy + + + align:start position:0% +three or four in the in the hierarchy +and that's essentially delaying the + + align:start position:0% +and that's essentially delaying the + + + align:start position:0% +and that's essentially delaying the +whole system so there's there's an + + align:start position:0% +whole system so there's there's an + + + align:start position:0% +whole system so there's there's an +example of how you know the large + + align:start position:0% +example of how you know the large + + + align:start position:0% +example of how you know the large +complexity of the system is is uh is + + align:start position:0% +complexity of the system is is uh is + + + align:start position:0% +complexity of the system is is uh is +causing + + align:start position:0% + + + + align:start position:0% + +issues but they are they are actually a + + align:start position:0% +issues but they are they are actually a + + + align:start position:0% +issues but they are they are actually a +plier to Talis alenia through the + + align:start position:0% +plier to Talis alenia through the + + + align:start position:0% +plier to Talis alenia through the +through the the whole chain right oh + + align:start position:0% +through the the whole chain right oh + + + align:start position:0% +through the the whole chain right oh +you're saying there's more going on than + + align:start position:0% +you're saying there's more going on than + + + align:start position:0% +you're saying there's more going on than +meets the eye yeah who knows who knows + + align:start position:0% +meets the eye yeah who knows who knows + + + align:start position:0% +meets the eye yeah who knows who knows +um okay and then finally here I want to + + align:start position:0% +um okay and then finally here I want to + + + align:start position:0% +um okay and then finally here I want to +mention uh application to a case study + + align:start position:0% +mention uh application to a case study + + + align:start position:0% +mention uh application to a case study +you know we used the canat 2016 + + align:start position:0% +you know we used the canat 2016 + + + align:start position:0% +you know we used the canat 2016 +competition as a quote endquote safe + + align:start position:0% +competition as a quote endquote safe + + + align:start position:0% +competition as a quote endquote safe +case study uh and I have to say I'm + + align:start position:0% +case study uh and I have to say I'm + + + align:start position:0% +case study uh and I have to say I'm +really pleased with with uh how this + + align:start position:0% +really pleased with with uh how this + + + align:start position:0% +really pleased with with uh how this +worked out you had the 47 requirements + + align:start position:0% +worked out you had the 47 requirements + + + align:start position:0% +worked out you had the 47 requirements +as a starter uh you improved them you + + align:start position:0% +as a starter uh you improved them you + + + align:start position:0% +as a starter uh you improved them you +group them uh and my comments about the + + align:start position:0% +group them uh and my comments about the + + + align:start position:0% +group them uh and my comments about the +pdrs that we had a week ago are you know + + align:start position:0% +pdrs that we had a week ago are you know + + + align:start position:0% +pdrs that we had a week ago are you know +all P all teams passed successfully the + + align:start position:0% +all P all teams passed successfully the + + + align:start position:0% +all P all teams passed successfully the +PDR you know if this was a real PDR we + + align:start position:0% +PDR you know if this was a real PDR we + + + align:start position:0% +PDR you know if this was a real PDR we +would have issued a couple rids I think + + align:start position:0% +would have issued a couple rids I think + + + align:start position:0% +would have issued a couple rids I think +there were some couple of teams were + + align:start position:0% +there were some couple of teams were + + + align:start position:0% +there were some couple of teams were +over budget or needed to work out their + + align:start position:0% +over budget or needed to work out their + + + align:start position:0% +over budget or needed to work out their +aerodynamics in more detail but by and + + align:start position:0% +aerodynamics in more detail but by and + + + align:start position:0% +aerodynamics in more detail but by and +large I thought this was an excellent + + align:start position:0% +large I thought this was an excellent + + + align:start position:0% +large I thought this was an excellent +application of system engineering + + align:start position:0% +application of system engineering + + + align:start position:0% +application of system engineering +concept went beyond my expectations um + + align:start position:0% +concept went beyond my expectations um + + + align:start position:0% +concept went beyond my expectations um +several of you mentioned the importance + + align:start position:0% +several of you mentioned the importance + + + align:start position:0% +several of you mentioned the importance +of concept generation you know hybrid + + align:start position:0% +of concept generation you know hybrid + + + align:start position:0% +of concept generation you know hybrid +use of structured and unstructured + + align:start position:0% +use of structured and unstructured + + + align:start position:0% +use of structured and unstructured +creativity techniques uh I know at least + + align:start position:0% +creativity techniques uh I know at least + + + align:start position:0% +creativity techniques uh I know at least +one team applied to actually go to the + + align:start position:0% +one team applied to actually go to the + + + align:start position:0% +one team applied to actually go to the +competition and this shows you a couple + + align:start position:0% +competition and this shows you a couple + + + align:start position:0% +competition and this shows you a couple +examples so we had one team here at epfl + + align:start position:0% +examples so we had one team here at epfl + + + align:start position:0% +examples so we had one team here at epfl +using a bio inspirate design uh this is + + align:start position:0% +using a bio inspirate design uh this is + + + align:start position:0% +using a bio inspirate design uh this is +an actual seed uh air foil that actually + + align:start position:0% +an actual seed uh air foil that actually + + + align:start position:0% +an actual seed uh air foil that actually +occurs in nature and then uh here's an + + align:start position:0% +occurs in nature and then uh here's an + + + align:start position:0% +occurs in nature and then uh here's an +example from MIT the ralo wing team 7 so + + align:start position:0% +example from MIT the ralo wing team 7 so + + + align:start position:0% +example from MIT the ralo wing team 7 so +um I'm sorry I didn't mention all the + + align:start position:0% +um I'm sorry I didn't mention all the + + + align:start position:0% +um I'm sorry I didn't mention all the +teams here but it was really great to + + align:start position:0% +teams here but it was really great to + + + align:start position:0% +teams here but it was really great to +see um the application of this in the + + align:start position:0% +see um the application of this in the + + + align:start position:0% +see um the application of this in the +canet um competition case so uh the last + + align:start position:0% +canet um competition case so uh the last + + + align:start position:0% +canet um competition case so uh the last +thing I want to do and I only have one + + align:start position:0% +thing I want to do and I only have one + + + align:start position:0% +thing I want to do and I only have one +minute left actually I'm already + + align:start position:0% +minute left actually I'm already + + + align:start position:0% +minute left actually I'm already +slightly over time but I just want to + + align:start position:0% +slightly over time but I just want to + + + align:start position:0% +slightly over time but I just want to +give you some career and study + + align:start position:0% +give you some career and study + + + align:start position:0% +give you some career and study +recommendations so first of all you know + + align:start position:0% +recommendations so first of all you know + + + align:start position:0% +recommendations so first of all you know +uh I want to make sure that you knew and + + align:start position:0% +uh I want to make sure that you knew and + + + align:start position:0% +uh I want to make sure that you knew and +I said this in the first lecture this is + + align:start position:0% +I said this in the first lecture this is + + + align:start position:0% +I said this in the first lecture this is +there's a lot more to system engineering + + align:start position:0% +there's a lot more to system engineering + + + align:start position:0% +there's a lot more to system engineering +um and systems research than we were + + align:start position:0% +um and systems research than we were + + + align:start position:0% +um and systems research than we were +able to cover in this class so this + + align:start position:0% +able to cover in this class so this + + + align:start position:0% +able to cover in this class so this +class is really what I call a door + + align:start position:0% +class is really what I call a door + + + align:start position:0% +class is really what I call a door +opener to the world of system + + align:start position:0% +opener to the world of system + + + align:start position:0% +opener to the world of system +engineering if you want to go deeper + + align:start position:0% +engineering if you want to go deeper + + + align:start position:0% +engineering if you want to go deeper +there are deeper subjects um you know + + align:start position:0% +there are deeper subjects um you know + + + align:start position:0% +there are deeper subjects um you know +modelbased system engineering is a big + + align:start position:0% +modelbased system engineering is a big + + + align:start position:0% +modelbased system engineering is a big +Trend system safety and then in the + + align:start position:0% +Trend system safety and then in the + + + align:start position:0% +Trend system safety and then in the +spring I'm teaching a class uh called + + align:start position:0% +spring I'm teaching a class uh called + + + align:start position:0% +spring I'm teaching a class uh called +multi-disciplinary system optimization + + align:start position:0% +multi-disciplinary system optimization + + + align:start position:0% +multi-disciplinary system optimization +and it there is actually a WebEx uh + + align:start position:0% +and it there is actually a WebEx uh + + + align:start position:0% +and it there is actually a WebEx uh +access to it as well so it's not going + + align:start position:0% +access to it as well so it's not going + + + align:start position:0% +access to it as well so it's not going +to be officially offered as an epfl + + align:start position:0% +to be officially offered as an epfl + + + align:start position:0% +to be officially offered as an epfl +class but if individual students here + + align:start position:0% +class but if individual students here + + + align:start position:0% +class but if individual students here +are interested please contact me + + align:start position:0% +are interested please contact me + + + align:start position:0% +are interested please contact me +self-study you know there's system + + align:start position:0% +self-study you know there's system + + + align:start position:0% +self-study you know there's system +engineering Journal there's i e journals + + align:start position:0% +engineering Journal there's i e journals + + + align:start position:0% +engineering Journal there's i e journals +there's also you know for some of you + + align:start position:0% +there's also you know for some of you + + + align:start position:0% +there's also you know for some of you +this is maybe a little too soon but uh + + align:start position:0% +this is maybe a little too soon but uh + + + align:start position:0% +this is maybe a little too soon but uh +there's there's professional degrees in + + align:start position:0% +there's there's professional degrees in + + + align:start position:0% +there's there's professional degrees in +system engineering um for example at MIT + + align:start position:0% +system engineering um for example at MIT + + + align:start position:0% +system engineering um for example at MIT +we have the SDM program system design + + align:start position:0% +we have the SDM program system design + + + align:start position:0% +we have the SDM program system design +and management the average age of the + + align:start position:0% +and management the average age of the + + + align:start position:0% +and management the average age of the +students in that program is + + align:start position:0% +students in that program is + + + align:start position:0% +students in that program is +33 uh but it is um you know they're sort + + align:start position:0% +33 uh but it is um you know they're sort + + + align:start position:0% +33 uh but it is um you know they're sort +of coming back to get their masters in + + align:start position:0% +of coming back to get their masters in + + + align:start position:0% +of coming back to get their masters in +system design and management uh and + + align:start position:0% +system design and management uh and + + + align:start position:0% +system design and management uh and +there quite a bit of slown content as + + align:start position:0% +there quite a bit of slown content as + + + align:start position:0% +there quite a bit of slown content as +well so Finance you know understanding + + align:start position:0% +well so Finance you know understanding + + + align:start position:0% +well so Finance you know understanding +the financial how to build a business + + align:start position:0% +the financial how to build a business + + + align:start position:0% +the financial how to build a business +case around systems as well uh + + align:start position:0% +case around systems as well uh + + + align:start position:0% +case around systems as well uh +professional experience you know getting + + align:start position:0% +professional experience you know getting + + + align:start position:0% +professional experience you know getting +experience on actual projects like at + + align:start position:0% +experience on actual projects like at + + + align:start position:0% +experience on actual projects like at +MIT for example rexus you know you got + + align:start position:0% +MIT for example rexus you know you got + + + align:start position:0% +MIT for example rexus you know you got +the clean space one project we heard + + align:start position:0% +the clean space one project we heard + + + align:start position:0% +the clean space one project we heard +about octanus one solar impulse there + + align:start position:0% +about octanus one solar impulse there + + + align:start position:0% +about octanus one solar impulse there +are a lot of opportunities or and we + + align:start position:0% +are a lot of opportunities or and we + + + align:start position:0% +are a lot of opportunities or and we +also had a couple of uh people here + + align:start position:0% +also had a couple of uh people here + + + align:start position:0% +also had a couple of uh people here +mention that you're starting your own + + align:start position:0% +mention that you're starting your own + + + align:start position:0% +mention that you're starting your own +company your own Venture and you know + + align:start position:0% +company your own Venture and you know + + + align:start position:0% +company your own Venture and you know +when you're doing that you you have to + + align:start position:0% +when you're doing that you you have to + + + align:start position:0% +when you're doing that you you have to +be the system system engineer you have + + align:start position:0% +be the system system engineer you have + + + align:start position:0% +be the system system engineer you have +to understand all of these things + + align:start position:0% +to understand all of these things + + + align:start position:0% +to understand all of these things +interfaces suppliers requirements + + align:start position:0% +interfaces suppliers requirements + + + align:start position:0% +interfaces suppliers requirements +markets all that has to be integrated + + align:start position:0% +markets all that has to be integrated + + + align:start position:0% +markets all that has to be integrated +finally um you did hear about en cozy we + + align:start position:0% +finally um you did hear about en cozy we + + + align:start position:0% +finally um you did hear about en cozy we +had a quick dial in with them at an + + align:start position:0% +had a quick dial in with them at an + + + align:start position:0% +had a quick dial in with them at an +earlier session so if you're interested + + align:start position:0% +earlier session so if you're interested + + + align:start position:0% +earlier session so if you're interested +you can join either as a student or + + align:start position:0% +you can join either as a student or + + + align:start position:0% +you can join either as a student or +professional member and also + + align:start position:0% +professional member and also + + + align:start position:0% +professional member and also +certification this class was not + + align:start position:0% +certification this class was not + + + align:start position:0% +certification this class was not +spefically + + align:start position:0% + + + + align:start position:0% + +a for that but if you're interested in + + align:start position:0% +a for that but if you're interested in + + + align:start position:0% +a for that but if you're interested in +this either have enough number of years + + align:start position:0% +this either have enough number of years + + + align:start position:0% +this either have enough number of years +of experience at the cep level and then + + align:start position:0% +of experience at the cep level and then + + + align:start position:0% +of experience at the cep level and then +finally please keep in touch and last + + align:start position:0% +finally please keep in touch and last + + + align:start position:0% +finally please keep in touch and last +but not least I want to thank all of you + + align:start position:0% +but not least I want to thank all of you + + + align:start position:0% +but not least I want to thank all of you +um the students at MIT at epfl our Tas + + align:start position:0% +um the students at MIT at epfl our Tas + + + align:start position:0% +um the students at MIT at epfl our Tas +uh le le Lou here at epfl Yana at MIT uh + + align:start position:0% +uh le le Lou here at epfl Yana at MIT uh + + + align:start position:0% +uh le le Lou here at epfl Yana at MIT uh +the technical staff who's been helping + + align:start position:0% +the technical staff who's been helping + + + align:start position:0% +the technical staff who's been helping +um you know run the technology uh vulker + + align:start position:0% +um you know run the technology uh vulker + + + align:start position:0% +um you know run the technology uh vulker +uh thank you and um and that's it so I + + align:start position:0% +uh thank you and um and that's it so I + + + align:start position:0% +uh thank you and um and that's it so I +want to thank all of you uh next week we + + align:start position:0% +want to thank all of you uh next week we + + + align:start position:0% +want to thank all of you uh next week we +do have a voluntary seminar on sort of + + align:start position:0% +do have a voluntary seminar on sort of + + + align:start position:0% +do have a voluntary seminar on sort of +future Trends and Manufacturing uh but + + align:start position:0% +future Trends and Manufacturing uh but + + + align:start position:0% +future Trends and Manufacturing uh but +again it's not mandatory uh it's going + + align:start position:0% +again it's not mandatory uh it's going + + + align:start position:0% +again it's not mandatory uh it's going +to be in the same place but it's like I + + align:start position:0% +to be in the same place but it's like I + + + align:start position:0% +to be in the same place but it's like I +said not part of the official class so + + align:start position:0% +said not part of the official class so + + + align:start position:0% +said not part of the official class so +with that sorry for running a little bit + + align:start position:0% +with that sorry for running a little bit + + + align:start position:0% +with that sorry for running a little bit +over time but um it's been really a joy + + align:start position:0% +over time but um it's been really a joy + + + align:start position:0% +over time but um it's been really a joy +to to teach this class in this kind of + + align:start position:0% +to to teach this class in this kind of + + + align:start position:0% +to to teach this class in this kind of +new + + align:start position:0% + + + + align:start position:0% + +format e \ No newline at end of file diff --git a/bf5IWKhSWRo.txt b/bf5IWKhSWRo.txt new file mode 100644 index 0000000000000000000000000000000000000000..e57a99098e22e438924363a05f72bb9194ba96e9 --- /dev/null +++ b/bf5IWKhSWRo.txt @@ -0,0 +1,14059 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit mitop courseware at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu so like we're here but don't + + align:start position:0% +ocw.mit.edu so like we're here but don't + + + align:start position:0% +ocw.mit.edu so like we're here but don't +forget about you know this + + align:start position:0% +forget about you know this + + + align:start position:0% +forget about you know this +and so the quiz is next Thursday uh I'm + + align:start position:0% +and so the quiz is next Thursday uh I'm + + + align:start position:0% +and so the quiz is next Thursday uh I'm +going to I'm going to send an email out + + align:start position:0% +going to I'm going to send an email out + + + align:start position:0% +going to I'm going to send an email out +with office + + align:start position:0% +with office + + + align:start position:0% +with office +hours uh uh for for that for you know + + align:start position:0% +hours uh uh for for that for you know + + + align:start position:0% +hours uh uh for for that for you know +extra time but if anyone wants to meet + + align:start position:0% +extra time but if anyone wants to meet + + + align:start position:0% +extra time but if anyone wants to meet +anytime just send me an email please + + align:start position:0% +anytime just send me an email please + + + align:start position:0% +anytime just send me an email please +okay this pet 2 we decided is going to + + align:start position:0% +okay this pet 2 we decided is going to + + + align:start position:0% +okay this pet 2 we decided is going to +be due uh the day before on May 9th and + + align:start position:0% +be due uh the day before on May 9th and + + + align:start position:0% +be due uh the day before on May 9th and +that's when your pet 3 will be posted as + + align:start position:0% +that's when your pet 3 will be posted as + + + align:start position:0% +that's when your pet 3 will be posted as +well okay and P set 3 will have to do + + align:start position:0% +well okay and P set 3 will have to do + + + align:start position:0% +well okay and P set 3 will have to do +with the things we we've been talking + + align:start position:0% +with the things we we've been talking + + + align:start position:0% +with the things we we've been talking +about uh the last last you know two + + align:start position:0% +about uh the last last you know two + + + align:start position:0% +about uh the last last you know two +lectures and today which is you know + + align:start position:0% +lectures and today which is you know + + + align:start position:0% +lectures and today which is you know +what what you can do with solids okay um + + align:start position:0% +what what you can do with solids okay um + + + align:start position:0% +what what you can do with solids okay um +any questions about the plan the + + align:start position:0% + + + + align:start position:0% + +schedule + + align:start position:0% +schedule + + + align:start position:0% +schedule +okay right now + + align:start position:0% +okay right now + + + align:start position:0% +okay right now +um now there are other practice problems + + align:start position:0% +um now there are other practice problems + + + align:start position:0% +um now there are other practice problems +um I'll do I'll throw one out from last + + align:start position:0% +um I'll do I'll throw one out from last + + + align:start position:0% +um I'll do I'll throw one out from last +year's quiz so that that's a practice + + align:start position:0% +year's quiz so that that's a practice + + + align:start position:0% +year's quiz so that that's a practice +quiz from uh that I I gave out you know + + align:start position:0% +quiz from uh that I I gave out you know + + + align:start position:0% +quiz from uh that I I gave out you know +a couple maybe a year ago or two um and + + align:start position:0% +a couple maybe a year ago or two um and + + + align:start position:0% +a couple maybe a year ago or two um and +then there's last year's quiz and I'll + + align:start position:0% +then there's last year's quiz and I'll + + + align:start position:0% +then there's last year's quiz and I'll +pull a problem or two out from that and + + align:start position:0% +pull a problem or two out from that and + + + align:start position:0% +pull a problem or two out from that and +and we'll do one today and then maybe + + align:start position:0% +and we'll do one today and then maybe + + + align:start position:0% +and we'll do one today and then maybe +we'll look at another one on Tuesday + + align:start position:0% +we'll look at another one on Tuesday + + + align:start position:0% +we'll look at another one on Tuesday +um + + align:start position:0% +um + + + align:start position:0% +um +uh what I want to cover in terms of the + + align:start position:0% +uh what I want to cover in terms of the + + + align:start position:0% +uh what I want to cover in terms of the +lecture material today is I want to kind + + align:start position:0% +lecture material today is I want to kind + + + align:start position:0% +lecture material today is I want to kind +of briefly start with that band + + align:start position:0% +of briefly start with that band + + + align:start position:0% +of briefly start with that band +structure and kpace and make sure we're + + align:start position:0% +structure and kpace and make sure we're + + + align:start position:0% +structure and kpace and make sure we're +feeling good about it okay and then um + + align:start position:0% +feeling good about it okay and then um + + + align:start position:0% +feeling good about it okay and then um +tell you sort of a few other things you + + align:start position:0% +tell you sort of a few other things you + + + align:start position:0% +tell you sort of a few other things you +can do right we've talked about the band + + align:start position:0% +can do right we've talked about the band + + + align:start position:0% +can do right we've talked about the band +structure we've talked about how um it + + align:start position:0% +structure we've talked about how um it + + + align:start position:0% +structure we've talked about how um it +it has so much information well what + + align:start position:0% +it has so much information well what + + + align:start position:0% +it has so much information well what +other kinds of information is there what + + align:start position:0% +other kinds of information is there what + + + align:start position:0% +other kinds of information is there what +can you do with these sorts of + + align:start position:0% +can you do with these sorts of + + + align:start position:0% +can you do with these sorts of +properties um of solids um we're we're + + align:start position:0% +properties um of solids um we're we're + + + align:start position:0% +properties um of solids um we're we're +not going to you know this is I love + + align:start position:0% +not going to you know this is I love + + + align:start position:0% +not going to you know this is I love +this cartoon at some point his theory + + align:start position:0% +this cartoon at some point his theory + + + align:start position:0% +this cartoon at some point his theory +becomes so abstract it can only be + + align:start position:0% +becomes so abstract it can only be + + + align:start position:0% +becomes so abstract it can only be +conveyed using interpretive dance and + + align:start position:0% +conveyed using interpretive dance and + + + align:start position:0% +conveyed using interpretive dance and +mostly it's because of the visuals that + + align:start position:0% +mostly it's because of the visuals that + + + align:start position:0% +mostly it's because of the visuals that +I get on on my colleagues here at MIT + + align:start position:0% +I get on on my colleagues here at MIT + + + align:start position:0% +I get on on my colleagues here at MIT +kind of just dancing but um + + align:start position:0% +kind of just dancing but um + + + align:start position:0% +kind of just dancing but um +but I you know we're not going to get + + align:start position:0% +but I you know we're not going to get + + + align:start position:0% +but I you know we're not going to get +this complicated right so the point + + align:start position:0% +this complicated right so the point + + + align:start position:0% +this complicated right so the point +isn't for me to do a lecture on + + align:start position:0% +isn't for me to do a lecture on + + + align:start position:0% +isn't for me to do a lecture on +transport Theory and and tell you you + + align:start position:0% +transport Theory and and tell you you + + + align:start position:0% +transport Theory and and tell you you +know uh all about phonons and go into + + align:start position:0% +know uh all about phonons and go into + + + align:start position:0% +know uh all about phonons and go into +great detail about these different + + align:start position:0% +great detail about these different + + + align:start position:0% +great detail about these different +things that is again not been our Point + + align:start position:0% +things that is again not been our Point + + + align:start position:0% +things that is again not been our Point +here the point is uh to keep relevant + + align:start position:0% +here the point is uh to keep relevant + + + align:start position:0% +here the point is uh to keep relevant +and keep pretty applied in in this in + + align:start position:0% +and keep pretty applied in in this in + + + align:start position:0% +and keep pretty applied in in this in +this class so so I'm you know I'm going + + align:start position:0% +this class so so I'm you know I'm going + + + align:start position:0% +this class so so I'm you know I'm going +to give you sort of just a little hint + + align:start position:0% +to give you sort of just a little hint + + + align:start position:0% +to give you sort of just a little hint +as to what you can do uh with the Doss + + align:start position:0% +as to what you can do uh with the Doss + + + align:start position:0% +as to what you can do uh with the Doss +and the band structure um but we're not + + align:start position:0% +and the band structure um but we're not + + + align:start position:0% +and the band structure um but we're not +going to go into great detail but you + + align:start position:0% +going to go into great detail but you + + + align:start position:0% +going to go into great detail but you +can find those details in many places + + align:start position:0% +can find those details in many places + + + align:start position:0% +can find those details in many places +online and in books and if you come to + + align:start position:0% +online and in books and if you come to + + + align:start position:0% +online and in books and if you come to +me I'm happy to talk about these + + align:start position:0% +me I'm happy to talk about these + + + align:start position:0% +me I'm happy to talk about these +Concepts that we'll talk about So the + + align:start position:0% +Concepts that we'll talk about So the + + + align:start position:0% +Concepts that we'll talk about So the +plan So the plan is we're going to do a + + align:start position:0% +plan So the plan is we're going to do a + + + align:start position:0% +plan So the plan is we're going to do a +little bit of review Cas Bas feeling + + align:start position:0% +little bit of review Cas Bas feeling + + + align:start position:0% +little bit of review Cas Bas feeling +good about Oneness all that and then I + + align:start position:0% +good about Oneness all that and then I + + + align:start position:0% +good about Oneness all that and then I +want to um show you that um that problem + + align:start position:0% +want to um show you that um that problem + + + align:start position:0% +want to um show you that um that problem +we'll talk about just one band structure + + align:start position:0% +we'll talk about just one band structure + + + align:start position:0% +we'll talk about just one band structure +problem that I happened to give last + + align:start position:0% +problem that I happened to give last + + + align:start position:0% +problem that I happened to give last +year on the exam and then we'll do some + + align:start position:0% +year on the exam and then we'll do some + + + align:start position:0% +year on the exam and then we'll do some +we'll we'll talk a little bit about uh + + align:start position:0% +we'll we'll talk a little bit about uh + + + align:start position:0% +we'll we'll talk a little bit about uh +some properties electron transport + + align:start position:0% +some properties electron transport + + + align:start position:0% +some properties electron transport +couple minutes and then we'll talk about + + align:start position:0% +couple minutes and then we'll talk about + + + align:start position:0% +couple minutes and then we'll talk about +magnetization and then we'll do some + + align:start position:0% +magnetization and then we'll do some + + + align:start position:0% +magnetization and then we'll do some +calculations together again because I + + align:start position:0% +calculations together again because I + + + align:start position:0% +calculations together again because I +think that's been really enjoyable + + align:start position:0% +think that's been really enjoyable + + + align:start position:0% +think that's been really enjoyable +actually seriously I mean I always enjoy + + align:start position:0% +actually seriously I mean I always enjoy + + + align:start position:0% +actually seriously I mean I always enjoy +calculating together but do you feel + + align:start position:0% +calculating together but do you feel + + + align:start position:0% +calculating together but do you feel +like uh how many of you feel like that's + + align:start position:0% +like uh how many of you feel like that's + + + align:start position:0% +like uh how many of you feel like that's +useful to do some simulations here in + + align:start position:0% +useful to do some simulations here in + + + align:start position:0% +useful to do some simulations here in +class one two more okay okay cuz I think + + align:start position:0% +class one two more okay okay cuz I think + + + align:start position:0% +class one two more okay okay cuz I think +you know please ask questions you know + + align:start position:0% +you know please ask questions you know + + + align:start position:0% +you know please ask questions you know +that's like this is the time you know + + align:start position:0% +that's like this is the time you know + + + align:start position:0% +that's like this is the time you know +because um this is where we can if you + + align:start position:0% +because um this is where we can if you + + + align:start position:0% +because um this is where we can if you +have any questions please stop and say + + align:start position:0% +have any questions please stop and say + + + align:start position:0% +have any questions please stop and say +like I got no idea what you're talking + + align:start position:0% +like I got no idea what you're talking + + + align:start position:0% +like I got no idea what you're talking +about like that's okay I love those you + + align:start position:0% +about like that's okay I love those you + + + align:start position:0% +about like that's okay I love those you +know that's that's what I want to hear + + align:start position:0% +know that's that's what I want to hear + + + align:start position:0% +know that's that's what I want to hear +well that's actually not what I want to + + align:start position:0% +well that's actually not what I want to + + + align:start position:0% +well that's actually not what I want to +hear but if I hear it it's fine you know + + align:start position:0% +hear but if I hear it it's fine you know + + + align:start position:0% +hear but if I hear it it's fine you know +that helps me to to know sort of where + + align:start position:0% +that helps me to to know sort of where + + + align:start position:0% +that helps me to to know sort of where +where we need to have a little + + align:start position:0% +where we need to have a little + + + align:start position:0% +where we need to have a little +discussion okay now this is the concept + + align:start position:0% +discussion okay now this is the concept + + + align:start position:0% +discussion okay now this is the concept +that we have to be uh we have to be + + align:start position:0% +that we have to be uh we have to be + + + align:start position:0% +that we have to be uh we have to be +really good good in our understanding + + align:start position:0% +really good good in our understanding + + + align:start position:0% +really good good in our understanding +with this is really the key of this um + + align:start position:0% +with this is really the key of this um + + + align:start position:0% +with this is really the key of this um +sort of second part of the second part + + align:start position:0% +sort of second part of the second part + + + align:start position:0% +sort of second part of the second part +if you want of the class which is we did + + align:start position:0% +if you want of the class which is we did + + + align:start position:0% +if you want of the class which is we did +Quantum we did Quantum for atoms we did + + align:start position:0% +Quantum we did Quantum for atoms we did + + + align:start position:0% +Quantum we did Quantum for atoms we did +Quantum for molecules and now it's all + + align:start position:0% +Quantum for molecules and now it's all + + + align:start position:0% +Quantum for molecules and now it's all +about solids and the big difference is + + align:start position:0% +about solids and the big difference is + + + align:start position:0% +about solids and the big difference is +that you when you when you have a solid + + align:start position:0% +that you when you when you have a solid + + + align:start position:0% +that you when you when you have a solid +you have you know over and over and over + + align:start position:0% +you have you know over and over and over + + + align:start position:0% +you have you know over and over and over +again the same atom or same couple of + + align:start position:0% +again the same atom or same couple of + + + align:start position:0% +again the same atom or same couple of +atoms in your basis and therefore the + + align:start position:0% +atoms in your basis and therefore the + + + align:start position:0% +atoms in your basis and therefore the +same potential that the electron + + align:start position:0% +same potential that the electron + + + align:start position:0% +same potential that the electron +feels and over and over again how many + + align:start position:0% + + + + align:start position:0% + +times if I had to give a + + align:start position:0% + + + + align:start position:0% + +number couple th well I'd say more like + + align:start position:0% +number couple th well I'd say more like + + + align:start position:0% +number couple th well I'd say more like +couple 10 to the 23rd + + align:start position:0% +couple 10 to the 23rd + + + align:start position:0% +couple 10 to the 23rd +thousands 10 + + align:start position:0% +thousands 10 + + + align:start position:0% +thousands 10 +23 um that's how right I mean if I take + + align:start position:0% +23 um that's how right I mean if I take + + + align:start position:0% +23 um that's how right I mean if I take +a piece of material + + align:start position:0% +a piece of material + + + align:start position:0% +a piece of material +you know like this big you know this big + + align:start position:0% +you know like this big you know this big + + + align:start position:0% +you know like this big you know this big +um you know that's how well even this + + align:start position:0% +um you know that's how well even this + + + align:start position:0% +um you know that's how well even this +big even really tiny you got like you + + align:start position:0% +big even really tiny you got like you + + + align:start position:0% +big even really tiny you got like you +know 10 23rd repeats of this potential + + align:start position:0% +know 10 23rd repeats of this potential + + + align:start position:0% +know 10 23rd repeats of this potential +that's a lot so it's almost + + align:start position:0% +that's a lot so it's almost + + + align:start position:0% +that's a lot so it's almost +infinite um and when you have that kind + + align:start position:0% +infinite um and when you have that kind + + + align:start position:0% +infinite um and when you have that kind +of periodically repeating well that the + + align:start position:0% +of periodically repeating well that the + + + align:start position:0% +of periodically repeating well that the +electron feels something happens okay + + align:start position:0% +electron feels something happens okay + + + align:start position:0% +electron feels something happens okay +and and the something that happens was + + align:start position:0% +and and the something that happens was + + + align:start position:0% +and and the something that happens was +this mathematical thing that who can + + align:start position:0% +this mathematical thing that who can + + + align:start position:0% +this mathematical thing that who can +remember what it's called a it it was a + + align:start position:0% +remember what it's called a it it was a + + + align:start position:0% +remember what it's called a it it was a +theorem I + + align:start position:0% +theorem I + + + align:start position:0% +theorem I +believe blocks + + align:start position:0% +believe blocks + + + align:start position:0% +believe blocks +theorem and we don't know how we don't + + align:start position:0% +theorem and we don't know how we don't + + + align:start position:0% +theorem and we don't know how we don't +need to know much about blocks theorem + + align:start position:0% +need to know much about blocks theorem + + + align:start position:0% +need to know much about blocks theorem +except the end + + align:start position:0% +except the end + + + align:start position:0% +except the end +game right the key is what it means and + + align:start position:0% +game right the key is what it means and + + + align:start position:0% +game right the key is what it means and +it's a + + align:start position:0% +it's a + + + align:start position:0% +it's a +mathematical + + align:start position:0% +mathematical + + + align:start position:0% +mathematical +um + + align:start position:0% +um + + + align:start position:0% +um +consequence it's a consequence of having + + align:start position:0% +consequence it's a consequence of having + + + align:start position:0% +consequence it's a consequence of having +an electron and therefore its solution + + align:start position:0% +an electron and therefore its solution + + + align:start position:0% +an electron and therefore its solution +being a wave function that solves the + + align:start position:0% +being a wave function that solves the + + + align:start position:0% +being a wave function that solves the +shary equation it's a consequence of + + align:start position:0% +shary equation it's a consequence of + + + align:start position:0% +shary equation it's a consequence of +having that in the context of a periodic + + align:start position:0% +having that in the context of a periodic + + + align:start position:0% +having that in the context of a periodic +potential right you can't get around + + align:start position:0% +potential right you can't get around + + + align:start position:0% +potential right you can't get around +it it's a theorem so you you got to have + + align:start position:0% +it it's a theorem so you you got to have + + + align:start position:0% +it it's a theorem so you you got to have +now + + align:start position:0% +now + + + align:start position:0% +now +this because of blocks theorem you got + + align:start position:0% +this because of blocks theorem you got + + + align:start position:0% +this because of blocks theorem you got +to have this sort of requirement if you + + align:start position:0% +to have this sort of requirement if you + + + align:start position:0% +to have this sort of requirement if you +want to think about as requirement that + + align:start position:0% +want to think about as requirement that + + + align:start position:0% +want to think about as requirement that +when the wave function + + align:start position:0% +when the wave function + + + align:start position:0% +when the wave function +repeats okay the properties just repeat + + align:start position:0% +repeats okay the properties just repeat + + + align:start position:0% +repeats okay the properties just repeat +the Den is the same here as it is here + + align:start position:0% +the Den is the same here as it is here + + + align:start position:0% +the Den is the same here as it is here +as it is here 10 the 23rd out but when + + align:start position:0% +as it is here 10 the 23rd out but when + + + align:start position:0% +as it is here 10 the 23rd out but when +the wave function repeats it picks up + + align:start position:0% +the wave function repeats it picks up + + + align:start position:0% +the wave function repeats it picks up +this phase + + align:start position:0% +this phase + + + align:start position:0% +this phase +okay and that phase is is a vector is a + + align:start position:0% +okay and that phase is is a vector is a + + + align:start position:0% +okay and that phase is is a vector is a +number that lives in k space that lives + + align:start position:0% +number that lives in k space that lives + + + align:start position:0% +number that lives in k space that lives +in the inverse space and that's why we + + align:start position:0% +in the inverse space and that's why we + + + align:start position:0% +in the inverse space and that's why we +spent all that time talking about what + + align:start position:0% +spent all that time talking about what + + + align:start position:0% +spent all that time talking about what +inverse space is what reciprocal space + + align:start position:0% +inverse space is what reciprocal space + + + align:start position:0% +inverse space is what reciprocal space +is right what k space is okay and that + + align:start position:0% +is right what k space is okay and that + + + align:start position:0% +is right what k space is okay and that +phase is + + align:start position:0% +phase is + + + align:start position:0% +phase is +um it it's you can think about it as a + + align:start position:0% +um it it's you can think about it as a + + + align:start position:0% +um it it's you can think about it as a +another quantum + + align:start position:0% +another quantum + + + align:start position:0% +another quantum +number so uh um the result of solving + + align:start position:0% +number so uh um the result of solving + + + align:start position:0% +number so uh um the result of solving +the shary equation and getting s in a + + align:start position:0% +the shary equation and getting s in a + + + align:start position:0% +the shary equation and getting s in a +periodic potential gives you a new + + align:start position:0% +periodic potential gives you a new + + + align:start position:0% +periodic potential gives you a new +number but it's very different than + + align:start position:0% +number but it's very different than + + + align:start position:0% +number but it's very different than +these + + align:start position:0% +these + + + align:start position:0% +these +numbers right how is it + + align:start position:0% +numbers right how is it + + + align:start position:0% +numbers right how is it +different + + align:start position:0% +different + + + align:start position:0% +different +yeah okay yeah right these are like one + + align:start position:0% +yeah okay yeah right these are like one + + + align:start position:0% +yeah okay yeah right these are like one +or two or 1 2 0 minus one um whereas + + align:start position:0% +or two or 1 2 0 minus one um whereas + + + align:start position:0% +or two or 1 2 0 minus one um whereas +this is like a a part of a place in + + align:start position:0% +this is like a a part of a place in + + + align:start position:0% +this is like a a part of a place in +space and what else is really + + align:start position:0% +space and what else is really + + + align:start position:0% +space and what else is really +interesting about that + + align:start position:0% + + + + align:start position:0% + +Vector it's in reciprocal + + align:start position:0% +Vector it's in reciprocal + + + align:start position:0% +Vector it's in reciprocal +space absolutely nice job I I'll you + + align:start position:0% +space absolutely nice job I I'll you + + + align:start position:0% +space absolutely nice job I I'll you +guys did that together totally team + + align:start position:0% +guys did that together totally team + + + align:start position:0% +guys did that together totally team +effort man I love it and what about what + + align:start position:0% +effort man I love it and what about what + + + align:start position:0% +effort man I love it and what about what +about uh what + + align:start position:0% +about uh what + + + align:start position:0% +about uh what +else it's a vector in reciprocal space + + align:start position:0% +else it's a vector in reciprocal space + + + align:start position:0% +else it's a vector in reciprocal space +what + + align:start position:0% +what + + + align:start position:0% +what +else okay well it it doesn't have to be + + align:start position:0% +else okay well it it doesn't have to be + + + align:start position:0% +else okay well it it doesn't have to be +but we said it doesn't really matter if + + align:start position:0% +but we said it doesn't really matter if + + + align:start position:0% +but we said it doesn't really matter if +you got out side of it because you just + + align:start position:0% +you got out side of it because you just + + + align:start position:0% +you got out side of it because you just +loop back but what about its variation + + align:start position:0% +loop back but what about its variation + + + align:start position:0% +loop back but what about its variation +in the bran Zone how can it + + align:start position:0% +in the bran Zone how can it + + + align:start position:0% +in the bran Zone how can it +vary yeah like this is a vector that can + + align:start position:0% +vary yeah like this is a vector that can + + + align:start position:0% +vary yeah like this is a vector that can +be + + align:start position:0% +be + + + align:start position:0% +be +anything this thing can be anything + + align:start position:0% +anything this thing can be anything + + + align:start position:0% +anything this thing can be anything +these things can they be anything can L + + align:start position:0% +these things can they be anything can L + + + align:start position:0% +these things can they be anything can L +be + + align:start position:0% +be + + + align:start position:0% +be +Pi or Square < TK of two right so it's a + + align:start position:0% +Pi or Square < TK of two right so it's a + + + align:start position:0% +Pi or Square < TK of two right so it's a +different kind of quantum + + align:start position:0% +different kind of quantum + + + align:start position:0% +different kind of quantum +number but you see it has this same + + align:start position:0% +number but you see it has this same + + + align:start position:0% +number but you see it has this same +impact right because I mean what do + + align:start position:0% +impact right because I mean what do + + + align:start position:0% +impact right because I mean what do +these things do right like what is what + + align:start position:0% +these things do right like what is what + + + align:start position:0% +these things do right like what is what +does this do anyway what's one of the + + align:start position:0% +does this do anyway what's one of the + + + align:start position:0% +does this do anyway what's one of the +things that this does or this what does + + align:start position:0% +things that this does or this what does + + + align:start position:0% +things that this does or this what does +l do when I change L from you know zero + + align:start position:0% +l do when I change L from you know zero + + + align:start position:0% +l do when I change L from you know zero +to one what's one of the things that + + align:start position:0% + + + + align:start position:0% + +happens yeah yeah okay so let's let's + + align:start position:0% +happens yeah yeah okay so let's let's + + + align:start position:0% +happens yeah yeah okay so let's let's +write that down so we're moving from s + + align:start position:0% +write that down so we're moving from s + + + align:start position:0% +write that down so we're moving from s +well let's change n up to here to S 1 s + + align:start position:0% +well let's change n up to here to S 1 s + + + align:start position:0% +well let's change n up to here to S 1 s +2s and now you just said I'm moving to + + align:start position:0% +2s and now you just said I'm moving to + + + align:start position:0% +2s and now you just said I'm moving to +P now what what what is this that I'm + + align:start position:0% +P now what what what is this that I'm + + + align:start position:0% +P now what what what is this that I'm +always just assuming you know is what + + align:start position:0% +always just assuming you know is what + + + align:start position:0% +always just assuming you know is what +that vertical axis is what is + + align:start position:0% +that vertical axis is what is + + + align:start position:0% +that vertical axis is what is +it yeah so this is the energy going from + + align:start position:0% +it yeah so this is the energy going from + + + align:start position:0% +it yeah so this is the energy going from +lowest to highest exactly and so what + + align:start position:0% +lowest to highest exactly and so what + + + align:start position:0% +lowest to highest exactly and so what +did + + align:start position:0% +did + + + align:start position:0% +did +changing the quantum number L from zero + + align:start position:0% +changing the quantum number L from zero + + + align:start position:0% +changing the quantum number L from zero +to one + + align:start position:0% +to one + + + align:start position:0% +to one +do yeah moves it around + + align:start position:0% +do yeah moves it around + + + align:start position:0% +do yeah moves it around +right it moves it + + align:start position:0% +right it moves it + + + align:start position:0% +right it moves it +around okay so you can change the energy + + align:start position:0% +around okay so you can change the energy + + + align:start position:0% +around okay so you can change the energy +and actually you can also not change the + + align:start position:0% +and actually you can also not change the + + + align:start position:0% +and actually you can also not change the +energy M doesn't change the energy it + + align:start position:0% +energy M doesn't change the energy it + + + align:start position:0% +energy M doesn't change the energy it +gives + + align:start position:0% +gives + + + align:start position:0% +gives +degeneracy right but but certainly you + + align:start position:0% +degeneracy right but but certainly you + + + align:start position:0% +degeneracy right but but certainly you +can change the energy by changing these + + align:start position:0% +can change the energy by changing these + + + align:start position:0% +can change the energy by changing these +quantum + + align:start position:0% +quantum + + + align:start position:0% +quantum +numbers um that's what you can do with + + align:start position:0% +numbers um that's what you can do with + + + align:start position:0% +numbers um that's what you can do with +K right that's what K does K which is a + + align:start position:0% +K right that's what K does K which is a + + + align:start position:0% +K right that's what K does K which is a +result of living in a periodically + + align:start position:0% +result of living in a periodically + + + align:start position:0% +result of living in a periodically +repeating World K changes the levels it + + align:start position:0% +repeating World K changes the levels it + + + align:start position:0% +repeating World K changes the levels it +CH it's the same idea but it's very + + align:start position:0% +CH it's the same idea but it's very + + + align:start position:0% +CH it's the same idea but it's very +different but it has the same + + align:start position:0% +different but it has the same + + + align:start position:0% +different but it has the same +impact it changes these levels around + + align:start position:0% +impact it changes these levels around + + + align:start position:0% +impact it changes these levels around +and it's very different because it can + + align:start position:0% +and it's very different because it can + + + align:start position:0% +and it's very different because it can +do it continuously as opposed to these + + align:start position:0% +do it continuously as opposed to these + + + align:start position:0% +do it continuously as opposed to these +you know big + + align:start position:0% +you know big + + + align:start position:0% +you know big +leaps that um that we have in the atom + + align:start position:0% +leaps that um that we have in the atom + + + align:start position:0% +leaps that um that we have in the atom +okay or in the molecule right the + + align:start position:0% +okay or in the molecule right the + + + align:start position:0% +okay or in the molecule right the +molecule they're also um discret levels + + align:start position:0% +molecule they're also um discret levels + + + align:start position:0% +molecule they're also um discret levels +and so we got this picture that we came + + align:start position:0% +and so we got this picture that we came + + + align:start position:0% +and so we got this picture that we came +to last + + align:start position:0% +to last + + + align:start position:0% +to last +time where you see K can be a + + align:start position:0% +time where you see K can be a + + + align:start position:0% +time where you see K can be a +vector and it can live anywhere in this + + align:start position:0% +vector and it can live anywhere in this + + + align:start position:0% +vector and it can live anywhere in this +inverse + + align:start position:0% +inverse + + + align:start position:0% +inverse +space + + align:start position:0% +space + + + align:start position:0% +space +okay and anytime you change it you may + + align:start position:0% +okay and anytime you change it you may + + + align:start position:0% +okay and anytime you change it you may +change the energy levels you may change + + align:start position:0% +change the energy levels you may change + + + align:start position:0% +change the energy levels you may change +them okay so it's a really important + + align:start position:0% +them okay so it's a really important + + + align:start position:0% +them okay so it's a really important +thing when you have a solid now + + align:start position:0% +thing when you have a solid now + + + align:start position:0% +thing when you have a solid now +you know + + align:start position:0% +you know + + + align:start position:0% +you know +again how how would if if I had a solid + + align:start position:0% +again how how would if if I had a solid + + + align:start position:0% +again how how would if if I had a solid +but if if I have a peri periodically + + align:start position:0% +but if if I have a peri periodically + + + align:start position:0% +but if if I have a peri periodically +repeating atom but the distance between + + align:start position:0% +repeating atom but the distance between + + + align:start position:0% +repeating atom but the distance between +them is like 100 + + align:start position:0% +them is like 100 + + + align:start position:0% +them is like 100 +angstroms what's the variation in these + + align:start position:0% +angstroms what's the variation in these + + + align:start position:0% +angstroms what's the variation in these +what's the impact of K going to be we + + align:start position:0% +what's the impact of K going to be we + + + align:start position:0% +what's the impact of K going to be we +did it in + + align:start position:0% +did it in + + + align:start position:0% +did it in +class relatively small like almost + + align:start position:0% +class relatively small like almost + + + align:start position:0% +class relatively small like almost +nothing because the whole effect comes + + align:start position:0% +nothing because the whole effect comes + + + align:start position:0% +nothing because the whole effect comes +comes from the fact that you have an + + align:start position:0% +comes from the fact that you have an + + + align:start position:0% +comes from the fact that you have an +electron in a lattice of periodic images + + align:start position:0% +electron in a lattice of periodic images + + + align:start position:0% +electron in a lattice of periodic images +where there a periodic potentials where + + align:start position:0% +where there a periodic potentials where + + + align:start position:0% +where there a periodic potentials where +they're sort of + + align:start position:0% +they're sort of + + + align:start position:0% +they're sort of +interacting right where they're close + + align:start position:0% +interacting right where they're close + + + align:start position:0% +interacting right where they're close +enough that there's some interaction if + + align:start position:0% +enough that there's some interaction if + + + align:start position:0% +enough that there's some interaction if +there's no interaction and your atoms + + align:start position:0% +there's no interaction and your atoms + + + align:start position:0% +there's no interaction and your atoms +are really really far + + align:start position:0% +are really really far + + + align:start position:0% +are really really far +apart okay then it's B basically like + + align:start position:0% +apart okay then it's B basically like + + + align:start position:0% +apart okay then it's B basically like +you just have isolated atoms sitting in + + align:start position:0% +you just have isolated atoms sitting in + + + align:start position:0% +you just have isolated atoms sitting in +their + + align:start position:0% +their + + + align:start position:0% +their +potentials and a whole lot empty space + + align:start position:0% +potentials and a whole lot empty space + + + align:start position:0% +potentials and a whole lot empty space +in between and then the levels will just + + align:start position:0% +in between and then the levels will just + + + align:start position:0% +in between and then the levels will just +look flat as a function of K space + + align:start position:0% +look flat as a function of K space + + + align:start position:0% +look flat as a function of K space +doesn't mean you can't vary K you could + + align:start position:0% +doesn't mean you can't vary K you could + + + align:start position:0% +doesn't mean you can't vary K you could +still vary K but the bands that you get + + align:start position:0% +still vary K but the bands that you get + + + align:start position:0% +still vary K but the bands that you get +will be completely flat they'll go back + + align:start position:0% +will be completely flat they'll go back + + + align:start position:0% +will be completely flat they'll go back +to your molecular level uh description + + align:start position:0% +to your molecular level uh description + + + align:start position:0% +to your molecular level uh description +so does everybody see + + align:start position:0% + + + + align:start position:0% + +that + + align:start position:0% +that + + + align:start position:0% +that +right and we talked about + + align:start position:0% +right and we talked about + + + align:start position:0% +right and we talked about +that and so then the question was well + + align:start position:0% +that and so then the question was well + + + align:start position:0% +that and so then the question was well +what playground of cave + + align:start position:0% +what playground of cave + + + align:start position:0% +what playground of cave +matters okay and this is um this is uh + + align:start position:0% +matters okay and this is um this is uh + + + align:start position:0% +matters okay and this is um this is uh +uh something we talked about but it's + + align:start position:0% +uh something we talked about but it's + + + align:start position:0% +uh something we talked about but it's +really important so I want to review it + + align:start position:0% +really important so I want to review it + + + align:start position:0% +really important so I want to review it +here okay so we just said that K is this + + align:start position:0% +here okay so we just said that K is this + + + align:start position:0% +here okay so we just said that K is this +new index that is a continuous variable + + align:start position:0% +new index that is a continuous variable + + + align:start position:0% +new index that is a continuous variable +that changes the energy levels it moves + + align:start position:0% +that changes the energy levels it moves + + + align:start position:0% +that changes the energy levels it moves +them + + align:start position:0% +them + + + align:start position:0% +them +around okay so what does that mean for a + + align:start position:0% +around okay so what does that mean for a + + + align:start position:0% +around okay so what does that mean for a +calculation right + + align:start position:0% +calculation right + + + align:start position:0% +calculation right +well one thing that it means is that + + align:start position:0% +well one thing that it means is that + + + align:start position:0% +well one thing that it means is that +when I do a calculation + + align:start position:0% +when I do a calculation + + + align:start position:0% +when I do a calculation +um I need a if if a if an energy + + align:start position:0% + + + + align:start position:0% + +level if an energy level can now do + + align:start position:0% +level if an energy level can now do + + + align:start position:0% +level if an energy level can now do +this right as a function of K then that + + align:start position:0% +this right as a function of K then that + + + align:start position:0% +this right as a function of K then that +means I need to actually do my + + align:start position:0% +means I need to actually do my + + + align:start position:0% +means I need to actually do my +calculation with a mesh of K points how + + align:start position:0% +calculation with a mesh of K points how + + + align:start position:0% +calculation with a mesh of K points how +fine a mesh do I + + align:start position:0% + + + + align:start position:0% + +need what's the answer to + + align:start position:0% +need what's the answer to + + + align:start position:0% +need what's the answer to +that thank you + + align:start position:0% +that thank you + + + align:start position:0% +that thank you +on + + align:start position:0% +on + + + align:start position:0% +on +what + + align:start position:0% +what + + + align:start position:0% +what +CS yeah how curvy are my + + align:start position:0% +CS yeah how curvy are my + + + align:start position:0% +CS yeah how curvy are my +bands this is pretty curvy so maybe I + + align:start position:0% +bands this is pretty curvy so maybe I + + + align:start position:0% +bands this is pretty curvy so maybe I +need a lot of K points to capture this + + align:start position:0% +need a lot of K points to capture this + + + align:start position:0% +need a lot of K points to capture this +if I don't it's you know you got a grid + + align:start position:0% +if I don't it's you know you got a grid + + + align:start position:0% +if I don't it's you know you got a grid +I'm solving for this problem on a grid + + align:start position:0% +I'm solving for this problem on a grid + + + align:start position:0% +I'm solving for this problem on a grid +of K points basically and if I only have + + align:start position:0% +of K points basically and if I only have + + + align:start position:0% +of K points basically and if I only have +a k Point here and here well let's say I + + align:start position:0% +a k Point here and here well let's say I + + + align:start position:0% +a k Point here and here well let's say I +have it actually even worse I have it + + align:start position:0% +have it actually even worse I have it + + + align:start position:0% +have it actually even worse I have it +here and + + align:start position:0% +here and + + + align:start position:0% +here and +here I'm not going to really um capture + + align:start position:0% +here I'm not going to really um capture + + + align:start position:0% +here I'm not going to really um capture +the right physics here okay so the + + align:start position:0% +the right physics here okay so the + + + align:start position:0% +the right physics here okay so the +density of K points has to be such that + + align:start position:0% +density of K points has to be such that + + + align:start position:0% +density of K points has to be such that +you capture the the features of in in + + align:start position:0% +you capture the the features of in in + + + align:start position:0% +you capture the the features of in in +terms of how much these energy levels + + align:start position:0% +terms of how much these energy levels + + + align:start position:0% +terms of how much these energy levels +vary so let's go back to these two atoms + + align:start position:0% +vary so let's go back to these two atoms + + + align:start position:0% +vary so let's go back to these two atoms +that are very far apart how many k + + align:start position:0% +that are very far apart how many k + + + align:start position:0% +that are very far apart how many k +points do I need for + + align:start position:0% + + + + align:start position:0% + +those what if they're really far + + align:start position:0% +those what if they're really far + + + align:start position:0% +those what if they're really far +apart one oh well all the calculations + + align:start position:0% +apart one oh well all the calculations + + + align:start position:0% +apart one oh well all the calculations +you've been doing until we did the + + align:start position:0% +you've been doing until we did the + + + align:start position:0% +you've been doing until we did the +solids everything before that was + + align:start position:0% +solids everything before that was + + + align:start position:0% +solids everything before that was +actually one k point it was at 0000 0 we + + align:start position:0% +actually one k point it was at 0000 0 we + + + align:start position:0% +actually one k point it was at 0000 0 we +never varied it right we never worried + + align:start position:0% +never varied it right we never worried + + + align:start position:0% +never varied it right we never worried +about it it was never a problem it was + + align:start position:0% +about it it was never a problem it was + + + align:start position:0% +about it it was never a problem it was +never an index okay so now if if the + + align:start position:0% +never an index okay so now if if the + + + align:start position:0% +never an index okay so now if if the +bands are flat you could just have one k + + align:start position:0% +bands are flat you could just have one k + + + align:start position:0% +bands are flat you could just have one k +point and you've got the variation of + + align:start position:0% +point and you've got the variation of + + + align:start position:0% +point and you've got the variation of +the Bands nailed since they don't vary + + align:start position:0% +the Bands nailed since they don't vary + + + align:start position:0% +the Bands nailed since they don't vary +so you just need the one but if they + + align:start position:0% +so you just need the one but if they + + + align:start position:0% +so you just need the one but if they +vary a lot like if I bring atoms + + align:start position:0% +vary a lot like if I bring atoms + + + align:start position:0% +vary a lot like if I bring atoms +together + + align:start position:0% +together + + + align:start position:0% +together +and they vary a lot and there's a lot of + + align:start position:0% +and they vary a lot and there's a lot of + + + align:start position:0% +and they vary a lot and there's a lot of +interaction then I just need more and + + align:start position:0% +interaction then I just need more and + + + align:start position:0% +interaction then I just need more and +more K points to represent that + + align:start position:0% +more K points to represent that + + + align:start position:0% +more K points to represent that +correctly okay so so the K points is is + + align:start position:0% +correctly okay so so the K points is is + + + align:start position:0% +correctly okay so so the K points is is +a is something that's now an essential + + align:start position:0% +a is something that's now an essential + + + align:start position:0% +a is something that's now an essential +part of your + + align:start position:0% +part of your + + + align:start position:0% +part of your +calculation now that's that's talking + + align:start position:0% +calculation now that's that's talking + + + align:start position:0% +calculation now that's that's talking +about what you need to get the density + + align:start position:0% +about what you need to get the density + + + align:start position:0% +about what you need to get the density +right which is to get the wave function + + align:start position:0% +right which is to get the wave function + + + align:start position:0% +right which is to get the wave function +right which is to get the energy levels + + align:start position:0% +right which is to get the energy levels + + + align:start position:0% +right which is to get the energy levels +right okay that's a + + align:start position:0% +right okay that's a + + + align:start position:0% +right okay that's a +new you know component of a quantum + + align:start position:0% +new you know component of a quantum + + + align:start position:0% +new you know component of a quantum +mechanical simulation but then there was + + align:start position:0% +mechanical simulation but then there was + + + align:start position:0% +mechanical simulation but then there was +this other thing that's actually kind of + + align:start position:0% +this other thing that's actually kind of + + + align:start position:0% +this other thing that's actually kind of +a little bit separate in a way okay + + align:start position:0% +a little bit separate in a way okay + + + align:start position:0% +a little bit separate in a way okay +which is um to visualize that + + align:start position:0% +which is um to visualize that + + + align:start position:0% +which is um to visualize that +variation okay now visualizing this + + align:start position:0% +variation okay now visualizing this + + + align:start position:0% +variation okay now visualizing this +variation leads to these plots which are + + align:start position:0% + + + + align:start position:0% + +called band structures this is the band + + align:start position:0% +called band structures this is the band + + + align:start position:0% +called band structures this is the band +structure of the + + align:start position:0% +structure of the + + + align:start position:0% +structure of the +material it's like uh oh it's like it's + + align:start position:0% +material it's like uh oh it's like it's + + + align:start position:0% +material it's like uh oh it's like it's +like a a you know it's another kind of + + align:start position:0% +like a a you know it's another kind of + + + align:start position:0% +like a a you know it's another kind of +phase map for for those of you who felt + + align:start position:0% +phase map for for those of you who felt + + + align:start position:0% +phase map for for those of you who felt +the excitement of phase diagrams in 3012 + + align:start position:0% +the excitement of phase diagrams in 3012 + + + align:start position:0% +the excitement of phase diagrams in 3012 +this is like a phase map for that + + align:start position:0% +this is like a phase map for that + + + align:start position:0% +this is like a phase map for that +electron okay um it's it's it's a really + + align:start position:0% +electron okay um it's it's it's a really + + + align:start position:0% +electron okay um it's it's it's a really +important um uh uh description right of + + align:start position:0% +important um uh uh description right of + + + align:start position:0% +important um uh uh description right of +how electrons behave in + + align:start position:0% +how electrons behave in + + + align:start position:0% +how electrons behave in +materials + + align:start position:0% +materials + + + align:start position:0% +materials +now this phase map is not everything + + align:start position:0% +now this phase map is not everything + + + align:start position:0% +now this phase map is not everything +going okay over there + + align:start position:0% +going okay over there + + + align:start position:0% +going okay over there +look look like you got hurt no you're + + align:start position:0% +look look like you got hurt no you're + + + align:start position:0% +look look like you got hurt no you're +good okay all right I got a little + + align:start position:0% +good okay all right I got a little + + + align:start position:0% +good okay all right I got a little +concerned but we're over it um the uh + + align:start position:0% +concerned but we're over it um the uh + + + align:start position:0% +concerned but we're over it um the uh +the the fa sorry the phase map okay + + align:start position:0% +the the fa sorry the phase map okay + + + align:start position:0% +the the fa sorry the phase map okay +is a walk through + + align:start position:0% +is a walk through + + + align:start position:0% +is a walk through +kpace now I just mentioned that you have + + align:start position:0% +kpace now I just mentioned that you have + + + align:start position:0% +kpace now I just mentioned that you have +a grid that you just have to put on here + + align:start position:0% +a grid that you just have to put on here + + + align:start position:0% +a grid that you just have to put on here +to do the + + align:start position:0% +to do the + + + align:start position:0% +to do the +calculation to get the Wiggles that may + + align:start position:0% +calculation to get the Wiggles that may + + + align:start position:0% +calculation to get the Wiggles that may +or may not be there well you should take + + align:start position:0% +or may not be there well you should take + + + align:start position:0% +or may not be there well you should take +a guess at whether you think they're + + align:start position:0% +a guess at whether you think they're + + + align:start position:0% +a guess at whether you think they're +there and then you should see and then + + align:start position:0% +there and then you should see and then + + + align:start position:0% +there and then you should see and then +you should converge it okay but now I'm + + align:start position:0% +you should converge it okay but now I'm + + + align:start position:0% +you should converge it okay but now I'm +taking a walk around in that + + align:start position:0% +taking a walk around in that + + + align:start position:0% +taking a walk around in that +zone and the question is where am I + + align:start position:0% +zone and the question is where am I + + + align:start position:0% +zone and the question is where am I +going to + + align:start position:0% +going to + + + align:start position:0% +going to +go I + + align:start position:0% +go I + + + align:start position:0% +go I +mean should I just go to eat I mean well + + align:start position:0% +mean should I just go to eat I mean well + + + align:start position:0% +mean should I just go to eat I mean well +I I'm using 4x4x4 K points so I'm using + + align:start position:0% +I I'm using 4x4x4 K points so I'm using + + + align:start position:0% +I I'm using 4x4x4 K points so I'm using +a grid of 64 points and I'm plopping it + + align:start position:0% +a grid of 64 points and I'm plopping it + + + align:start position:0% +a grid of 64 points and I'm plopping it +down into this bran Zone should I just + + align:start position:0% +down into this bran Zone should I just + + + align:start position:0% +down into this bran Zone should I just +map should I just look at the energies + + align:start position:0% +map should I just look at the energies + + + align:start position:0% +map should I just look at the energies +at each of those points well you could + + align:start position:0% +at each of those points well you could + + + align:start position:0% +at each of those points well you could +do that right I mean ideally you'd like + + align:start position:0% +do that right I mean ideally you'd like + + + align:start position:0% +do that right I mean ideally you'd like +to be able to visualize this variation + + align:start position:0% +to be able to visualize this variation + + + align:start position:0% +to be able to visualize this variation +all over kpace at every single point + + align:start position:0% +all over kpace at every single point + + + align:start position:0% +all over kpace at every single point +okay but uh why don't we do that tell me + + align:start position:0% +okay but uh why don't we do that tell me + + + align:start position:0% +okay but uh why don't we do that tell me +why we don't usually do that + + align:start position:0% + + + + align:start position:0% + +interested is + + align:start position:0% +interested is + + + align:start position:0% +interested is +surfaces well that is true but that's + + align:start position:0% +surfaces well that is true but that's + + + align:start position:0% +surfaces well that is true but that's +more of a kind of density thing so + + align:start position:0% +more of a kind of density thing so + + + align:start position:0% +more of a kind of density thing so +that's where you want to know the + + align:start position:0% +that's where you want to know the + + + align:start position:0% +that's where you want to know the +density the iso surface of the charge + + align:start position:0% +density the iso surface of the charge + + + align:start position:0% +density the iso surface of the charge +density yeah me c + + align:start position:0% +density yeah me c + + + align:start position:0% +density yeah me c +am okay that's definitely that's + + align:start position:0% +am okay that's definitely that's + + + align:start position:0% +am okay that's definitely that's +definitely true but let's say you didn't + + align:start position:0% +definitely true but let's say you didn't + + + align:start position:0% +definitely true but let's say you didn't +know + + align:start position:0% + + + + align:start position:0% + +that what if I you know I mean I'd like + + align:start position:0% +that what if I you know I mean I'd like + + + align:start position:0% +that what if I you know I mean I'd like +to do the most accurate calculation + + align:start position:0% +to do the most accurate calculation + + + align:start position:0% +to do the most accurate calculation +possible let's say I put a grid over + + align:start position:0% +possible let's say I put a grid over + + + align:start position:0% +possible let's say I put a grid over +this case base of like a million by a + + align:start position:0% +this case base of like a million by a + + + align:start position:0% +this case base of like a million by a +million by a million don't do that on + + align:start position:0% +million by a million don't do that on + + + align:start position:0% +million by a million don't do that on +the nanohub we'll get + + align:start position:0% +the nanohub we'll get + + + align:start position:0% +the nanohub we'll get +calls um but let's say I did that now + + align:start position:0% +calls um but let's say I did that now + + + align:start position:0% +calls um but let's say I did that now +I've got a million by a million by a + + align:start position:0% +I've got a million by a million by a + + + align:start position:0% +I've got a million by a million by a +million points in here where each point + + align:start position:0% +million points in here where each point + + + align:start position:0% +million points in here where each point +has a new set of energy you know igen + + align:start position:0% +has a new set of energy you know igen + + + align:start position:0% +has a new set of energy you know igen +values why can't I just visualize + + align:start position:0% + + + + align:start position:0% + +that yeah would it just take too long to + + align:start position:0% +that yeah would it just take too long to + + + align:start position:0% +that yeah would it just take too long to +well it would take a whole lot of time + + align:start position:0% +well it would take a whole lot of time + + + align:start position:0% +well it would take a whole lot of time +to simulate what about visualizing it + + align:start position:0% +to simulate what about visualizing it + + + align:start position:0% +to simulate what about visualizing it +though how would you visualize + + align:start position:0% + + + + align:start position:0% + +that but see it's not even really just + + align:start position:0% +that but see it's not even really just + + + align:start position:0% +that but see it's not even really just +3D right because at each one of these + + align:start position:0% +3D right because at each one of these + + + align:start position:0% +3D right because at each one of these +points I've got a spectrum of + + align:start position:0% +points I've got a spectrum of + + + align:start position:0% +points I've got a spectrum of +energies right so it's kind of like yeah + + align:start position:0% +energies right so it's kind of like yeah + + + align:start position:0% +energies right so it's kind of like yeah +it's making your it would be making your + + align:start position:0% +it's making your it would be making your + + + align:start position:0% +it's making your it would be making your +igen values each one into a 3D curve and + + align:start position:0% +igen values each one into a 3D curve and + + + align:start position:0% +igen values each one into a 3D curve and +I want to look at them + + align:start position:0% +I want to look at them + + + align:start position:0% +I want to look at them +all right uh you could do + + align:start position:0% +all right uh you could do + + + align:start position:0% +all right uh you could do +that you know but how you know you got + + align:start position:0% +that you know but how you know you got + + + align:start position:0% +that you know but how you know you got +to remember if I go down to here I'm not + + align:start position:0% +to remember if I go down to here I'm not + + + align:start position:0% +to remember if I go down to here I'm not +you can't just do it within this volume + + align:start position:0% +you can't just do it within this volume + + + align:start position:0% +you can't just do it within this volume +element right my igen values might shift + + align:start position:0% +element right my igen values might shift + + + align:start position:0% +element right my igen values might shift +up down sideways you know not sideways + + align:start position:0% +up down sideways you know not sideways + + + align:start position:0% +up down sideways you know not sideways +up down um in different ways depending + + align:start position:0% +up down um in different ways depending + + + align:start position:0% +up down um in different ways depending +on where I am how am I actually going to + + align:start position:0% +on where I am how am I actually going to + + + align:start position:0% +on where I am how am I actually going to +see that right so you know in a way what + + align:start position:0% +see that right so you know in a way what + + + align:start position:0% +see that right so you know in a way what +we have is actually a strong + + align:start position:0% +we have is actually a strong + + + align:start position:0% +we have is actually a strong +visualization challenge that um + + align:start position:0% +visualization challenge that um + + + align:start position:0% +visualization challenge that um +luckily there's sort of a good story + + align:start position:0% +luckily there's sort of a good story + + + align:start position:0% +luckily there's sort of a good story +here because + + align:start position:0% +here because + + + align:start position:0% +here because +luckily um we can just look at a 2d + + align:start position:0% +luckily um we can just look at a 2d + + + align:start position:0% +luckily um we can just look at a 2d +map of this variation and get all the + + align:start position:0% +map of this variation and get all the + + + align:start position:0% +map of this variation and get all the +information we need okay for almost all + + align:start position:0% +information we need okay for almost all + + + align:start position:0% +information we need okay for almost all +materials and so how do you get a 2d map + + align:start position:0% +materials and so how do you get a 2d map + + + align:start position:0% +materials and so how do you get a 2d map +well then instead of doing like the + + align:start position:0% +well then instead of doing like the + + + align:start position:0% +well then instead of doing like the +whole of volume you just walk through + + align:start position:0% +whole of volume you just walk through + + + align:start position:0% +whole of volume you just walk through +the volume along lines you literally + + align:start position:0% +the volume along lines you literally + + + align:start position:0% +the volume along lines you literally +just walk along this line and then this + + align:start position:0% +just walk along this line and then this + + + align:start position:0% +just walk along this line and then this +line and then down and then back and + + align:start position:0% +line and then down and then back and + + + align:start position:0% +line and then down and then back and +then up and as you're doing this walk + + align:start position:0% +then up and as you're doing this walk + + + align:start position:0% +then up and as you're doing this walk +through + + align:start position:0% +through + + + align:start position:0% +through +kpace you plot the energy bands and you + + align:start position:0% +kpace you plot the energy bands and you + + + align:start position:0% +kpace you plot the energy bands and you +connect them together and you draw lines + + align:start position:0% +connect them together and you draw lines + + + align:start position:0% +connect them together and you draw lines +between those you know those connections + + align:start position:0% +between those you know those connections + + + align:start position:0% +between those you know those connections +this is the same energy level just + + align:start position:0% +this is the same energy level just + + + align:start position:0% +this is the same energy level just +moving around along that + + align:start position:0% +moving around along that + + + align:start position:0% +moving around along that +walk okay + + align:start position:0% +walk okay + + + align:start position:0% +walk okay +so that seems like an + + align:start position:0% +so that seems like an + + + align:start position:0% +so that seems like an +oversimplification because I'm not going + + align:start position:0% +oversimplification because I'm not going + + + align:start position:0% +oversimplification because I'm not going +through the whole bran Zone by any means + + align:start position:0% +through the whole bran Zone by any means + + + align:start position:0% +through the whole bran Zone by any means +I'm just going through very particular + + align:start position:0% +I'm just going through very particular + + + align:start position:0% +I'm just going through very particular +lines in there and yet it's all we need + + align:start position:0% +lines in there and yet it's all we need + + + align:start position:0% +lines in there and yet it's all we need +and the reason is that um most of the + + align:start position:0% +and the reason is that um most of the + + + align:start position:0% +and the reason is that um most of the +things I want to know about a material + + align:start position:0% +things I want to know about a material + + + align:start position:0% +things I want to know about a material +most of the things I want to know are + + align:start position:0% +most of the things I want to know are + + + align:start position:0% +most of the things I want to know are +going to come from the the variation + + align:start position:0% +going to come from the the variation + + + align:start position:0% +going to come from the the variation +between in these bands between High + + align:start position:0% +between in these bands between High + + + align:start position:0% +between in these bands between High +symmetry points in kpace okay so I can + + align:start position:0% +symmetry points in kpace okay so I can + + + align:start position:0% +symmetry points in kpace okay so I can +go to other points in the bruan zone and + + align:start position:0% +go to other points in the bruan zone and + + + align:start position:0% +go to other points in the bruan zone and +I'll get other levels I'll get you know + + align:start position:0% +I'll get other levels I'll get you know + + + align:start position:0% +I'll get other levels I'll get you know +a different set of levels um but it's + + align:start position:0% +a different set of levels um but it's + + + align:start position:0% +a different set of levels um but it's +probably not going to add to my + + align:start position:0% +probably not going to add to my + + + align:start position:0% +probably not going to add to my +knowledge of the + + align:start position:0% +knowledge of the + + + align:start position:0% +knowledge of the +material and the properties that I can + + align:start position:0% +material and the properties that I can + + + align:start position:0% +material and the properties that I can +get so for example you know I'm very + + align:start position:0% +get so for example you know I'm very + + + align:start position:0% +get so for example you know I'm very +interested in this where this has a + + align:start position:0% +interested in this where this has a + + + align:start position:0% +interested in this where this has a +maximum the veilance band and where the + + align:start position:0% +maximum the veilance band and where the + + + align:start position:0% +maximum the veilance band and where the +cond ruction band has a minimum right + + align:start position:0% +cond ruction band has a minimum right + + + align:start position:0% +cond ruction band has a minimum right +and you'll notice the minimum for + + align:start position:0% +and you'll notice the minimum for + + + align:start position:0% +and you'll notice the minimum for +silicon is actually not at this High + + align:start position:0% +silicon is actually not at this High + + + align:start position:0% +silicon is actually not at this High +symmetry point x but it does come along + + align:start position:0% +symmetry point x but it does come along + + + align:start position:0% +symmetry point x but it does come along +the path to X from another high symmetry + + align:start position:0% +the path to X from another high symmetry + + + align:start position:0% +the path to X from another high symmetry +Point gamma it came along that path and + + align:start position:0% +Point gamma it came along that path and + + + align:start position:0% +Point gamma it came along that path and +there's no place in case base that gives + + align:start position:0% +there's no place in case base that gives + + + align:start position:0% +there's no place in case base that gives +me a lower point you see so I nailed the + + align:start position:0% +me a lower point you see so I nailed the + + + align:start position:0% +me a lower point you see so I nailed the +thing I needed I nailed it by going from + + align:start position:0% +thing I needed I nailed it by going from + + + align:start position:0% +thing I needed I nailed it by going from +one high symmetry point to another and + + align:start position:0% +one high symmetry point to another and + + + align:start position:0% +one high symmetry point to another and +that's what a band diagram is it's a + + align:start position:0% +that's what a band diagram is it's a + + + align:start position:0% +that's what a band diagram is it's a +it's a walk through Cas space along + + align:start position:0% +it's a walk through Cas space along + + + align:start position:0% +it's a walk through Cas space along +lines between High symmetry points and + + align:start position:0% +lines between High symmetry points and + + + align:start position:0% +lines between High symmetry points and +that gives you the map that you need and + + align:start position:0% +that gives you the map that you need and + + + align:start position:0% +that gives you the map that you need and +it's a really nice these sometimes look + + align:start position:0% +it's a really nice these sometimes look + + + align:start position:0% +it's a really nice these sometimes look +really complicated but just think it's + + align:start position:0% +really complicated but just think it's + + + align:start position:0% +really complicated but just think it's +saving you a whole lot of trouble and + + align:start position:0% +saving you a whole lot of trouble and + + + align:start position:0% +saving you a whole lot of trouble and +you know compared to all the data you + + align:start position:0% +you know compared to all the data you + + + align:start position:0% +you know compared to all the data you +actually could have but it's giving you + + align:start position:0% +actually could have but it's giving you + + + align:start position:0% +actually could have but it's giving you +what you need are there any + + align:start position:0% +what you need are there any + + + align:start position:0% +what you need are there any +uh questions about + + align:start position:0% +uh questions about + + + align:start position:0% +uh questions about +that it's kind of sort of the key Point + + align:start position:0% +that it's kind of sort of the key Point + + + align:start position:0% +that it's kind of sort of the key Point +here from this um band structure + + align:start position:0% + + + + align:start position:0% + +and we talked about how + + align:start position:0% +and we talked about how + + + align:start position:0% +and we talked about how +um you uh you know we've talked about + + align:start position:0% +um you uh you know we've talked about + + + align:start position:0% +um you uh you know we've talked about +this how you you get your bands just + + align:start position:0% +this how you you get your bands just + + + align:start position:0% +this how you you get your bands just +like in an atom or a molecule you get + + align:start position:0% +like in an atom or a molecule you get + + + align:start position:0% +like in an atom or a molecule you get +your energy levels from solving the Sher + + align:start position:0% +your energy levels from solving the Sher + + + align:start position:0% +your energy levels from solving the Sher +equation and then you fill them + + align:start position:0% +equation and then you fill them + + + align:start position:0% +equation and then you fill them +up right using the poly exclusion rule + + align:start position:0% +up right using the poly exclusion rule + + + align:start position:0% +up right using the poly exclusion rule +right um add a little bit of Huns rule + + align:start position:0% +right um add a little bit of Huns rule + + + align:start position:0% +right um add a little bit of Huns rule +to it although that can be violated + + align:start position:0% +to it although that can be violated + + + align:start position:0% +to it although that can be violated +don't tell anyone um and uh and you fill + + align:start position:0% +don't tell anyone um and uh and you fill + + + align:start position:0% +don't tell anyone um and uh and you fill +them up and then you're done and when + + align:start position:0% +them up and then you're done and when + + + align:start position:0% +them up and then you're done and when +you're done you've got your firmy energy + + align:start position:0% +you're done you've got your firmy energy + + + align:start position:0% +you're done you've got your firmy energy +okay um that that's now it's the same + + align:start position:0% +okay um that that's now it's the same + + + align:start position:0% +okay um that that's now it's the same +exact thing here in the band structure + + align:start position:0% +exact thing here in the band structure + + + align:start position:0% +exact thing here in the band structure +okay you you fill your bands up until + + align:start position:0% +okay you you fill your bands up until + + + align:start position:0% +okay you you fill your bands up until +you've you filled them up with the + + align:start position:0% +you've you filled them up with the + + + align:start position:0% +you've you filled them up with the +number of electrons that you had in your + + align:start position:0% +number of electrons that you had in your + + + align:start position:0% +number of electrons that you had in your +simulation okay and uh then you've got + + align:start position:0% +simulation okay and uh then you've got + + + align:start position:0% +simulation okay and uh then you've got +your fir energy and then if there's a + + align:start position:0% +your fir energy and then if there's a + + + align:start position:0% +your fir energy and then if there's a +small Gap there and no bands cross it it + + align:start position:0% +small Gap there and no bands cross it it + + + align:start position:0% +small Gap there and no bands cross it it +cannot be a what + + align:start position:0% + + + + align:start position:0% + +it cannot be + + align:start position:0% +it cannot be + + + align:start position:0% +it cannot be +a a metal it can be a + + align:start position:0% +a a metal it can be a + + + align:start position:0% +a a metal it can be a +conductor it can be a conductor a + + align:start position:0% +conductor it can be a conductor a + + + align:start position:0% +conductor it can be a conductor a +semiconductor or a really bad insulating + + align:start position:0% +semiconductor or a really bad insulating + + + align:start position:0% +semiconductor or a really bad insulating +conductor also known as an + + align:start position:0% +conductor also known as an + + + align:start position:0% +conductor also known as an +insulator but it can't be a + + align:start position:0% +insulator but it can't be a + + + align:start position:0% +insulator but it can't be a +metal right because if if no bands cross + + align:start position:0% +metal right because if if no bands cross + + + align:start position:0% +metal right because if if no bands cross +if there's a gap here between where you + + align:start position:0% +if there's a gap here between where you + + + align:start position:0% +if there's a gap here between where you +filled to and the next place then it's + + align:start position:0% +filled to and the next place then it's + + + align:start position:0% +filled to and the next place then it's +not a metal okay + + align:start position:0% +not a metal okay + + + align:start position:0% +not a metal okay +so we talked about that um and that's uh + + align:start position:0% +so we talked about that um and that's uh + + + align:start position:0% +so we talked about that um and that's uh +uh certainly if you have an odd number + + align:start position:0% +uh certainly if you have an odd number + + + align:start position:0% +uh certainly if you have an odd number +of electrons it has to be a metal + + align:start position:0% +of electrons it has to be a metal + + + align:start position:0% +of electrons it has to be a metal +okay um and there's a calculation I + + align:start position:0% +okay um and there's a calculation I + + + align:start position:0% +okay um and there's a calculation I +showed this last time uh of an insulator + + align:start position:0% +showed this last time uh of an insulator + + + align:start position:0% +showed this last time uh of an insulator +and we we also talked about how these + + align:start position:0% +and we we also talked about how these + + + align:start position:0% +and we we also talked about how these +um this density of + + align:start position:0% +um this density of + + + align:start position:0% +um this density of +States okay is another really important + + align:start position:0% +States okay is another really important + + + align:start position:0% +States okay is another really important +thing here and since this is in your + + align:start position:0% +thing here and since this is in your + + + align:start position:0% +thing here and since this is in your +homework as well in your current pet + + align:start position:0% +homework as well in your current pet + + + align:start position:0% +homework as well in your current pet +um now I'll get to transport in a sec um + + align:start position:0% +um now I'll get to transport in a sec um + + + align:start position:0% +um now I'll get to transport in a sec um +I want to make sure we know what density + + align:start position:0% +I want to make sure we know what density + + + align:start position:0% +I want to make sure we know what density +of states is okay + + align:start position:0% +of states is okay + + + align:start position:0% +of states is okay +um so what would the density of states + + align:start position:0% +um so what would the density of states + + + align:start position:0% +um so what would the density of states +of the um somebody tell me what the + + align:start position:0% +of the um somebody tell me what the + + + align:start position:0% +of the um somebody tell me what the +density of + + align:start position:0% +density of + + + align:start position:0% +density of +states + + align:start position:0% +states + + + align:start position:0% +states +of the carbon atom would look + + align:start position:0% + + + + align:start position:0% + +like okay so let's let's draw so we had + + align:start position:0% +like okay so let's let's draw so we had + + + align:start position:0% +like okay so let's let's draw so we had +the carbon at would have 1 s and 2 + + align:start position:0% +the carbon at would have 1 s and 2 + + + align:start position:0% +the carbon at would have 1 s and 2 +s and 2 p and how many would I put + + align:start position:0% +s and 2 p and how many would I put + + + align:start position:0% +s and 2 p and how many would I put +here okay and what about the next one + + align:start position:0% +here okay and what about the next one + + + align:start position:0% +here okay and what about the next one +okay I'm liking it and + + align:start position:0% +okay I'm liking it and + + + align:start position:0% +okay I'm liking it and +here two okay like that oh oh wait hold + + align:start position:0% +here two okay like that oh oh wait hold + + + align:start position:0% +here two okay like that oh oh wait hold +on okay thank you like this oh sorry all + + align:start position:0% +on okay thank you like this oh sorry all + + + align:start position:0% +on okay thank you like this oh sorry all +right that would be an open open shell + + align:start position:0% +right that would be an open open shell + + + align:start position:0% +right that would be an open open shell +signal it thank you very much okay now + + align:start position:0% +signal it thank you very much okay now + + + align:start position:0% +signal it thank you very much okay now +um okay so what's my what's my Den + + align:start position:0% +um okay so what's my what's my Den + + + align:start position:0% +um okay so what's my what's my Den +states of this how do I do + + align:start position:0% +states of this how do I do + + + align:start position:0% +states of this how do I do +it okay yeah so I'm seeing people go + + align:start position:0% +it okay yeah so I'm seeing people go + + + align:start position:0% +it okay yeah so I'm seeing people go +like this so this now so this was energy + + align:start position:0% +like this so this now so this was energy + + + align:start position:0% +like this so this now so this was energy +here and now this is going to be energy + + align:start position:0% + + + + align:start position:0% + +here okay what's my next + + align:start position:0% +here okay what's my next + + + align:start position:0% +here okay what's my next +step drawing a curve drawing a curve + + align:start position:0% +step drawing a curve drawing a curve + + + align:start position:0% +step drawing a curve drawing a curve +okay I'm going to draw a curve what is + + align:start position:0% +okay I'm going to draw a curve what is + + + align:start position:0% +okay I'm going to draw a curve what is +that that's 1 s why not I've just + + align:start position:0% +that that's 1 s why not I've just + + + align:start position:0% +that that's 1 s why not I've just +broadened it we'll make that 1 s + + align:start position:0% +broadened it we'll make that 1 s + + + align:start position:0% +broadened it we'll make that 1 s +and what's my next curve I want to draw + + align:start position:0% +and what's my next curve I want to draw + + + align:start position:0% +and what's my next curve I want to draw +okay sure and it should be spaced such + + align:start position:0% +okay sure and it should be spaced such + + + align:start position:0% +okay sure and it should be spaced such +that it is um it is about you know it + + align:start position:0% +that it is um it is about you know it + + + align:start position:0% +that it is um it is about you know it +should be the right energy spacing that + + align:start position:0% +should be the right energy spacing that + + + align:start position:0% +should be the right energy spacing that +I get from my quantum mechanical + + align:start position:0% +I get from my quantum mechanical + + + align:start position:0% +I get from my quantum mechanical +simulations okay and what's + + align:start position:0% +simulations okay and what's + + + align:start position:0% +simulations okay and what's +next to P let's make this go out + + align:start position:0% +next to P let's make this go out + + + align:start position:0% +next to P let's make this go out +further okay now 2p now how should I do + + align:start position:0% +further okay now 2p now how should I do + + + align:start position:0% +further okay now 2p now how should I do +this should I make it the same + + align:start position:0% + + + + align:start position:0% + +shift it + + align:start position:0% +shift it + + + align:start position:0% +shift it +down same is it different than to + + align:start position:0% + + + + align:start position:0% + +us well let's see I mean I had two + + align:start position:0% +us well let's see I mean I had two + + + align:start position:0% +us well let's see I mean I had two +electrons in each of these how many + + align:start position:0% +electrons in each of these how many + + + align:start position:0% +electrons in each of these how many +electrons could go into + + align:start position:0% +electrons could go into + + + align:start position:0% +electrons could go into +2p six right so I actually have more + + align:start position:0% +2p six right so I actually have more + + + align:start position:0% +2p six right so I actually have more +states there I have three times as many + + align:start position:0% +states there I have three times as many + + + align:start position:0% +states there I have three times as many +as here so in a way if you're thinking + + align:start position:0% +as here so in a way if you're thinking + + + align:start position:0% +as here so in a way if you're thinking +about these as sort of a vertical line + + align:start position:0% +about these as sort of a vertical line + + + align:start position:0% +about these as sort of a vertical line +okay that is um that that is spread out + + align:start position:0% +okay that is um that that is spread out + + + align:start position:0% +okay that is um that that is spread out +by some smoothing function just to make + + align:start position:0% +by some smoothing function just to make + + + align:start position:0% +by some smoothing function just to make +it into a nice pretty + + align:start position:0% +it into a nice pretty + + + align:start position:0% +it into a nice pretty +curve I mean if it's an atom if it's + + align:start position:0% +curve I mean if it's an atom if it's + + + align:start position:0% +curve I mean if it's an atom if it's +really an atom then it's really just a + + align:start position:0% +really an atom then it's really just a + + + align:start position:0% +really an atom then it's really just a +line it's a Delta function okay + + align:start position:0% +line it's a Delta function okay + + + align:start position:0% +line it's a Delta function okay +um but then this should have three lines + + align:start position:0% +um but then this should have three lines + + + align:start position:0% +um but then this should have three lines +all on top of each other right and so if + + align:start position:0% +all on top of each other right and so if + + + align:start position:0% +all on top of each other right and so if +if I look at that it's going to lead to + + align:start position:0% +if I look at that it's going to lead to + + + align:start position:0% +if I look at that it's going to lead to +a a bigger + + align:start position:0% +a a bigger + + + align:start position:0% +a a bigger +Peak right that has you know more area + + align:start position:0% +Peak right that has you know more area + + + align:start position:0% +Peak right that has you know more area +under it right three times as much yeah + + align:start position:0% +under it right three times as much yeah + + + align:start position:0% +under it right three times as much yeah +okay so you can you can fit six + + align:start position:0% +okay so you can you can fit six + + + align:start position:0% +okay so you can you can fit six +electrons into this peak this is what + + align:start position:0% +electrons into this peak this is what + + + align:start position:0% +electrons into this peak this is what +the density of states is right it is + + align:start position:0% +the density of states is right it is + + + align:start position:0% +the density of states is right it is +uh the density of + + align:start position:0% +uh the density of + + + align:start position:0% +uh the density of +States um it is these levels it's these + + align:start position:0% +States um it is these levels it's these + + + align:start position:0% +States um it is these levels it's these +levels okay does everybody see that now + + align:start position:0% +levels okay does everybody see that now + + + align:start position:0% +levels okay does everybody see that now +where's my firmy energy + + align:start position:0% +where's my firmy energy + + + align:start position:0% +where's my firmy energy +for the carbon + + align:start position:0% + + + + align:start position:0% + +atom is it over + + align:start position:0% + + + + align:start position:0% + +here + + align:start position:0% + + + + align:start position:0% + +here it feels like it should be here + + align:start position:0% +here it feels like it should be here + + + align:start position:0% +here it feels like it should be here +right we like firmy energies between + + align:start position:0% +right we like firmy energies between + + + align:start position:0% +right we like firmy energies between +Peaks but that's just because we like + + align:start position:0% +Peaks but that's just because we like + + + align:start position:0% +Peaks but that's just because we like +semiconductors no we like Metals too and + + align:start position:0% +semiconductors no we like Metals too and + + + align:start position:0% +semiconductors no we like Metals too and +insulators they're all good so where + + align:start position:0% +insulators they're all good so where + + + align:start position:0% +insulators they're all good so where +should it be + + align:start position:0% +should it be + + + align:start position:0% +should it be +does this sound + + align:start position:0% +does this sound + + + align:start position:0% +does this sound +good over + + align:start position:0% + + + + align:start position:0% + +here somebody tell me when to + + align:start position:0% +here somebody tell me when to + + + align:start position:0% +here somebody tell me when to +stop somebody say + + align:start position:0% +stop somebody say + + + align:start position:0% +stop somebody say +stop yeah okay now why am I stopping + + align:start position:0% +stop yeah okay now why am I stopping + + + align:start position:0% +stop yeah okay now why am I stopping +here so that's my firmy + + align:start position:0% +here so that's my firmy + + + align:start position:0% +here so that's my firmy +energy for the carbon atom why is it + + align:start position:0% + + + + align:start position:0% + +there well it's an atom so let's not + + align:start position:0% +there well it's an atom so let's not + + + align:start position:0% +there well it's an atom so let's not +think about it necessarily as conducting + + align:start position:0% + + + + align:start position:0% + +that's the definition right I mean here + + align:start position:0% +that's the definition right I mean here + + + align:start position:0% +that's the definition right I mean here +I here I filled and I stopped well yeah + + align:start position:0% +I here I filled and I stopped well yeah + + + align:start position:0% +I here I filled and I stopped well yeah +so here I filled and I stopped and here + + align:start position:0% +so here I filled and I stopped and here + + + align:start position:0% +so here I filled and I stopped and here +I filled and I stopped and what uh the + + align:start position:0% +I filled and I stopped and what uh the + + + align:start position:0% +I filled and I stopped and what uh the +gentleman over there said is it's where + + align:start position:0% +gentleman over there said is it's where + + + align:start position:0% +gentleman over there said is it's where +you stop filling right and so here is + + align:start position:0% +you stop filling right and so here is + + + align:start position:0% +you stop filling right and so here is +where I stopped filling because I had + + align:start position:0% +where I stopped filling because I had + + + align:start position:0% +where I stopped filling because I had +this peak of + + align:start position:0% +this peak of + + + align:start position:0% +this peak of +states right it's a peak of states the + + align:start position:0% +states right it's a peak of states the + + + align:start position:0% +states right it's a peak of states the +density of + + align:start position:0% +density of + + + align:start position:0% +density of +states that is only filled by two + + align:start position:0% +states that is only filled by two + + + align:start position:0% +states that is only filled by two +electrons + + align:start position:0% +electrons + + + align:start position:0% +electrons +right does everybody see that right so + + align:start position:0% +right does everybody see that right so + + + align:start position:0% +right does everybody see that right so +you know so if I had + + align:start position:0% +you know so if I had + + + align:start position:0% +you know so if I had +um um something else like say neon would + + align:start position:0% +um um something else like say neon would + + + align:start position:0% +um um something else like say neon would +my firy energy be inside the + + align:start position:0% +my firy energy be inside the + + + align:start position:0% +my firy energy be inside the +peak no just outside of it because I + + align:start position:0% +peak no just outside of it because I + + + align:start position:0% +peak no just outside of it because I +would have filled it right yeah besides + + align:start position:0% +would have filled it right yeah besides + + + align:start position:0% +would have filled it right yeah besides +the change in the location of the FY + + align:start position:0% +the change in the location of the FY + + + align:start position:0% +the change in the location of the FY +energy would like the density States be + + align:start position:0% +energy would like the density States be + + + align:start position:0% +energy would like the density States be +like look the same for like nitrogen + + align:start position:0% +like look the same for like nitrogen + + + align:start position:0% +like look the same for like nitrogen +it's very good question it would + + align:start position:0% +it's very good question it would + + + align:start position:0% +it's very good question it would +actually in the sense that you know if + + align:start position:0% +actually in the sense that you know if + + + align:start position:0% +actually in the sense that you know if +you're looking at atoms all you're + + align:start position:0% +you're looking at atoms all you're + + + align:start position:0% +you're looking at atoms all you're +really doing you know a density of + + align:start position:0% +really doing you know a density of + + + align:start position:0% +really doing you know a density of +states is a little bit of an odd thing + + align:start position:0% +states is a little bit of an odd thing + + + align:start position:0% +states is a little bit of an odd thing +for an atom but I'm trying to explain it + + align:start position:0% +for an atom but I'm trying to explain it + + + align:start position:0% +for an atom but I'm trying to explain it +in the context of atoms because I really + + align:start position:0% +in the context of atoms because I really + + + align:start position:0% +in the context of atoms because I really +want you guys to see the connection okay + + align:start position:0% +want you guys to see the connection okay + + + align:start position:0% +want you guys to see the connection okay +and really what's what it is um but if + + align:start position:0% +and really what's what it is um but if + + + align:start position:0% +and really what's what it is um but if +you look at atoms they're just they're + + align:start position:0% +you look at atoms they're just they're + + + align:start position:0% +you look at atoms they're just they're +nothing more than levels and those + + align:start position:0% +nothing more than levels and those + + + align:start position:0% +nothing more than levels and those +discret + + align:start position:0% +discret + + + align:start position:0% +discret +levels okay become little shapes that + + align:start position:0% +levels okay become little shapes that + + + align:start position:0% +levels okay become little shapes that +you broaden a little so it would look + + align:start position:0% +you broaden a little so it would look + + + align:start position:0% +you broaden a little so it would look +the same as nitrogen because in nitrogen + + align:start position:0% +the same as nitrogen because in nitrogen + + + align:start position:0% +the same as nitrogen because in nitrogen +you would have that now what does that + + align:start position:0% +you would have that now what does that + + + align:start position:0% +you would have that now what does that +do well it'll change these energy level + + align:start position:0% +do well it'll change these energy level + + + align:start position:0% +do well it'll change these energy level +positions it'll shift them around right + + align:start position:0% +positions it'll shift them around right + + + align:start position:0% +positions it'll shift them around right +this may even change the 1s may go down + + align:start position:0% +this may even change the 1s may go down + + + align:start position:0% +this may even change the 1s may go down +or up this may change a little and then + + align:start position:0% +or up this may change a little and then + + + align:start position:0% +or up this may change a little and then +here you're going to change not the peak + + align:start position:0% +here you're going to change not the peak + + + align:start position:0% +here you're going to change not the peak +because you still got six states in you + + align:start position:0% +because you still got six states in you + + + align:start position:0% +because you still got six states in you +know you still got six electrons you can + + align:start position:0% +know you still got six electrons you can + + + align:start position:0% +know you still got six electrons you can +put in there but you will change the + + align:start position:0% +put in there but you will change the + + + align:start position:0% +put in there but you will change the +firmy energy within the peak because you + + align:start position:0% +firmy energy within the peak because you + + + align:start position:0% +firmy energy within the peak because you +can fill it by one + + align:start position:0% +can fill it by one + + + align:start position:0% +can fill it by one +more okay + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% +um + + + align:start position:0% +um +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +so and you know just like going all the + + align:start position:0% +so and you know just like going all the + + + align:start position:0% +so and you know just like going all the +way back to our first or second + + align:start position:0% +way back to our first or second + + + align:start position:0% +way back to our first or second +lecture where we had the orbitals of + + align:start position:0% +lecture where we had the orbitals of + + + align:start position:0% +lecture where we had the orbitals of +hydro of the hydrogen atom okay so we + + align:start position:0% +hydro of the hydrogen atom okay so we + + + align:start position:0% +hydro of the hydrogen atom okay so we +had the the nucleus and we had this + + align:start position:0% +had the the nucleus and we had this + + + align:start position:0% +had the the nucleus and we had this +electron that does not + + align:start position:0% +electron that does not + + + align:start position:0% +electron that does not +orbit but there it is orbiting and then + + align:start position:0% +orbit but there it is orbiting and then + + + align:start position:0% +orbit but there it is orbiting and then +we had like the 1s and then we had like + + align:start position:0% +we had like the 1s and then we had like + + + align:start position:0% +we had like the 1s and then we had like +the 2s + + align:start position:0% +the 2s + + + align:start position:0% +the 2s +and remember how we talked about it can + + align:start position:0% +and remember how we talked about it can + + + align:start position:0% +and remember how we talked about it can +actually make transitions between the + + align:start position:0% +actually make transitions between the + + + align:start position:0% +actually make transitions between the +two without actually existing between + + align:start position:0% +two without actually existing between + + + align:start position:0% +two without actually existing between +the two right there sometimes it has to + + align:start position:0% +the two right there sometimes it has to + + + align:start position:0% +the two right there sometimes it has to +cross paths which are totally forbidden + + align:start position:0% +cross paths which are totally forbidden + + + align:start position:0% +cross paths which are totally forbidden +it's sort of exciting it's like some + + align:start position:0% +it's sort of exciting it's like some + + + align:start position:0% +it's sort of exciting it's like some +sort of interesting fiction right that + + align:start position:0% +sort of interesting fiction right that + + + align:start position:0% +sort of interesting fiction right that +this electron is going on an adventure + + align:start position:0% +this electron is going on an adventure + + + align:start position:0% +this electron is going on an adventure +and well that's what this is right there + + align:start position:0% +and well that's what this is right there + + + align:start position:0% +and well that's what this is right there +is no state in here in this energy so + + align:start position:0% +is no state in here in this energy so + + + align:start position:0% +is no state in here in this energy so +the Doss tells you that too right that + + align:start position:0% +the Doss tells you that too right that + + + align:start position:0% +the Doss tells you that too right that +is is what's in the Dos that information + + align:start position:0% +is is what's in the Dos that information + + + align:start position:0% +is is what's in the Dos that information +is contained in the Doss there cannot + + align:start position:0% +is contained in the Doss there cannot + + + align:start position:0% +is contained in the Doss there cannot +be an + + align:start position:0% +be an + + + align:start position:0% +be an +electron with an energy that where + + align:start position:0% +electron with an energy that where + + + align:start position:0% +electron with an energy that where +there's no Doss there's no states to + + align:start position:0% +there's no Doss there's no states to + + + align:start position:0% +there's no Doss there's no states to +support it there okay so you know for an + + align:start position:0% +support it there okay so you know for an + + + align:start position:0% +support it there okay so you know for an +atom like the hydrogen atom or the + + align:start position:0% +atom like the hydrogen atom or the + + + align:start position:0% +atom like the hydrogen atom or the +carbon atom as well that's fairly + + align:start position:0% +carbon atom as well that's fairly + + + align:start position:0% +carbon atom as well that's fairly +obvious because you had your levels and + + align:start position:0% +obvious because you had your levels and + + + align:start position:0% +obvious because you had your levels and +you knew it couldn't be in between those + + align:start position:0% +you knew it couldn't be in between those + + + align:start position:0% +you knew it couldn't be in between those +levels that's the quantization stuff we + + align:start position:0% +levels that's the quantization stuff we + + + align:start position:0% +levels that's the quantization stuff we +talked about but now when you you get to + + align:start position:0% +talked about but now when you you get to + + + align:start position:0% +talked about but now when you you get to +solids and it's a more messy + + align:start position:0% +solids and it's a more messy + + + align:start position:0% +solids and it's a more messy +picture right but it's the same + + align:start position:0% +picture right but it's the same + + + align:start position:0% +picture right but it's the same +understanding that you get out of it + + align:start position:0% +understanding that you get out of it + + + align:start position:0% +understanding that you get out of it +it's the same exact understanding + + align:start position:0% +it's the same exact understanding + + + align:start position:0% +it's the same exact understanding +so what you do + + align:start position:0% +so what you do + + + align:start position:0% +so what you do +for you know atom molecule or solid is + + align:start position:0% +for you know atom molecule or solid is + + + align:start position:0% +for you know atom molecule or solid is +you take your levels you take your + + align:start position:0% +you take your levels you take your + + + align:start position:0% +you take your levels you take your +levels and you turn them + + align:start position:0% +levels and you turn them + + + align:start position:0% +levels and you turn them +over and you count up the number of + + align:start position:0% +over and you count up the number of + + + align:start position:0% +over and you count up the number of +states right and and that that has to be + + align:start position:0% +states right and and that that has to be + + + align:start position:0% +states right and and that that has to be +the same and you get shapes to the Doss + + align:start position:0% +the same and you get shapes to the Doss + + + align:start position:0% +the same and you get shapes to the Doss +if it was an atom I just had these + + align:start position:0% +if it was an atom I just had these + + + align:start position:0% +if it was an atom I just had these +little lines here from the levels and I + + align:start position:0% +little lines here from the levels and I + + + align:start position:0% +little lines here from the levels and I +broaden them now the levels are no + + align:start position:0% +broaden them now the levels are no + + + align:start position:0% +broaden them now the levels are no +longer + + align:start position:0% +longer + + + align:start position:0% +longer +flat if it's a solid they can vary and + + align:start position:0% +flat if it's a solid they can vary and + + + align:start position:0% +flat if it's a solid they can vary and +that when you turn that that on its side + + align:start position:0% +that when you turn that that on its side + + + align:start position:0% +that when you turn that that on its side +it can be like really kind of + + align:start position:0% +it can be like really kind of + + + align:start position:0% +it can be like really kind of +different right but it's telling you the + + align:start position:0% +different right but it's telling you the + + + align:start position:0% +different right but it's telling you the +same thing it's telling you exactly the + + align:start position:0% +same thing it's telling you exactly the + + + align:start position:0% +same thing it's telling you exactly the +same thing you're filling your electrons + + align:start position:0% +same thing you're filling your electrons + + + align:start position:0% +same thing you're filling your electrons +up through here and you're stopping well + + align:start position:0% +up through here and you're stopping well + + + align:start position:0% +up through here and you're stopping well +I don't know is that the firy energy I + + align:start position:0% +I don't know is that the firy energy I + + + align:start position:0% +I don't know is that the firy energy I +didn't tell you but if it is is then + + align:start position:0% +didn't tell you but if it is is then + + + align:start position:0% +didn't tell you but if it is is then +you're stopping there and those are your + + align:start position:0% +you're stopping there and those are your + + + align:start position:0% +you're stopping there and those are your +unoccupied bands and so forth okay does + + align:start position:0% +unoccupied bands and so forth okay does + + + align:start position:0% +unoccupied bands and so forth okay does +everybody see that it's the same + + align:start position:0% +everybody see that it's the same + + + align:start position:0% +everybody see that it's the same +uh same idea but it's more complicated + + align:start position:0% +uh same idea but it's more complicated + + + align:start position:0% +uh same idea but it's more complicated +when you have these curviness + + align:start position:0% +when you have these curviness + + + align:start position:0% +when you have these curviness +is yeah + + align:start position:0% +is yeah + + + align:start position:0% +is yeah +right we + + align:start position:0% +right we + + + align:start position:0% +right we +good sort of any + + align:start position:0% +good sort of any + + + align:start position:0% +good sort of any +questions + + align:start position:0% +questions + + + align:start position:0% +questions +thoughts yeah so you're looking at alop + + align:start position:0% +thoughts yeah so you're looking at alop + + + align:start position:0% +thoughts yeah so you're looking at alop +system so this Cas you have done I'm + + align:start position:0% +system so this Cas you have done I'm + + + align:start position:0% +system so this Cas you have done I'm +assuming that for gra this system be + + align:start position:0% +assuming that for gra this system be + + + align:start position:0% +assuming that for gra this system be +completely different completely + + align:start position:0% +completely different completely + + + align:start position:0% +completely different completely +different and so how and so how does + + align:start position:0% +different and so how and so how does + + + align:start position:0% +different and so how and so how does +that TI to solid density of States it's + + align:start position:0% +that TI to solid density of States it's + + + align:start position:0% +that TI to solid density of States it's +you can write the density of states for + + align:start position:0% +you can write the density of states for + + + align:start position:0% +you can write the density of states for +any + + align:start position:0% +any + + + align:start position:0% +any +material and and the same uh concept + + align:start position:0% +material and and the same uh concept + + + align:start position:0% +material and and the same uh concept +always holds right that you have these + + align:start position:0% +always holds right that you have these + + + align:start position:0% +always holds right that you have these +accessible places where the electron can + + align:start position:0% +accessible places where the electron can + + + align:start position:0% +accessible places where the electron can +be with + + align:start position:0% +be with + + + align:start position:0% +be with +some probability of them being there + + align:start position:0% +some probability of them being there + + + align:start position:0% +some probability of them being there +right um in other words it it it's all + + align:start position:0% +right um in other words it it it's all + + + align:start position:0% +right um in other words it it it's all +about how many possible energy levels + + align:start position:0% +about how many possible energy levels + + + align:start position:0% +about how many possible energy levels +you you have as a function of energy + + align:start position:0% +you you have as a function of energy + + + align:start position:0% +you you have as a function of energy +that's really what it is and so you know + + align:start position:0% +that's really what it is and so you know + + + align:start position:0% +that's really what it is and so you know +whatever material you have the density + + align:start position:0% +whatever material you have the density + + + align:start position:0% +whatever material you have the density +of states is is is simply has the same + + align:start position:0% +of states is is is simply has the same + + + align:start position:0% +of states is is is simply has the same +meaning but it will look very different + + align:start position:0% +meaning but it will look very different + + + align:start position:0% +meaning but it will look very different +and in Diamond you're going to get a big + + align:start position:0% +and in Diamond you're going to get a big + + + align:start position:0% +and in Diamond you're going to get a big +band Gap and in graphite well it's a + + align:start position:0% +band Gap and in graphite well it's a + + + align:start position:0% +band Gap and in graphite well it's a +metal right you have a Crossing in + + align:start position:0% +metal right you have a Crossing in + + + align:start position:0% +metal right you have a Crossing in +graphine you have a Crossing um at one + + align:start position:0% +graphine you have a Crossing um at one + + + align:start position:0% +graphine you have a Crossing um at one +part in the band structure goes right + + align:start position:0% +part in the band structure goes right + + + align:start position:0% +part in the band structure goes right +through the what would have been the + + align:start position:0% +through the what would have been the + + + align:start position:0% +through the what would have been the +Gap + + align:start position:0% +Gap + + + align:start position:0% +Gap +okay + + align:start position:0% + + + + align:start position:0% + +um and you know and that's why when you + + align:start position:0% +um and you know and that's why when you + + + align:start position:0% +um and you know and that's why when you +do your homework uh when you do p at + + align:start position:0% +do your homework uh when you do p at + + + align:start position:0% +do your homework uh when you do p at +five the the you know there are sort of + + align:start position:0% +five the the you know there are sort of + + + align:start position:0% +five the the you know there are sort of +two ways I want you to think about how + + align:start position:0% +two ways I want you to think about how + + + align:start position:0% +two ways I want you to think about how +these molecules absorb light one way is + + align:start position:0% +these molecules absorb light one way is + + + align:start position:0% +these molecules absorb light one way is +that they just have some cut + + align:start position:0% +that they just have some cut + + + align:start position:0% +that they just have some cut +off below which in energy or above which + + align:start position:0% +off below which in energy or above which + + + align:start position:0% +off below which in energy or above which +in wavelength they cannot absorb light + + align:start position:0% +in wavelength they cannot absorb light + + + align:start position:0% +in wavelength they cannot absorb light +so that's just a single cut off but the + + align:start position:0% +so that's just a single cut off but the + + + align:start position:0% +so that's just a single cut off but the +other way is to actually use the + + align:start position:0% +other way is to actually use the + + + align:start position:0% +other way is to actually use the +features in this in this uh plot of + + align:start position:0% +features in this in this uh plot of + + + align:start position:0% +features in this in this uh plot of +levels of accessible States for the + + align:start position:0% +levels of accessible States for the + + + align:start position:0% +levels of accessible States for the +electrons to use this + + align:start position:0% +electrons to use this + + + align:start position:0% +electrons to use this +information and and wait the absorption + + align:start position:0% +information and and wait the absorption + + + align:start position:0% +information and and wait the absorption +of the Sun by this because that's + + align:start position:0% +of the Sun by this because that's + + + align:start position:0% +of the Sun by this because that's +actually what's really going + + align:start position:0% +actually what's really going + + + align:start position:0% +actually what's really going +on okay is that the molecule cannot + + align:start position:0% +on okay is that the molecule cannot + + + align:start position:0% +on okay is that the molecule cannot +absorb the same at all the wavelengths + + align:start position:0% +absorb the same at all the wavelengths + + + align:start position:0% +absorb the same at all the wavelengths +of light because in some places it can't + + align:start position:0% +of light because in some places it can't + + + align:start position:0% +of light because in some places it can't +absorb any light right in some parts of + + align:start position:0% +absorb any light right in some parts of + + + align:start position:0% +absorb any light right in some parts of +the Doss there's no probability so + + align:start position:0% +the Doss there's no probability so + + + align:start position:0% +the Doss there's no probability so +that's um that turns out to have a + + align:start position:0% +that's um that turns out to have a + + + align:start position:0% +that's um that turns out to have a +really big + + align:start position:0% +really big + + + align:start position:0% +really big +impact + + align:start position:0% +impact + + + align:start position:0% +impact +right okay questions thoughts now let me + + align:start position:0% +right okay questions thoughts now let me + + + align:start position:0% +right okay questions thoughts now let me +um before I go + + align:start position:0% +um before I go + + + align:start position:0% +um before I go +on it's okay I I thought maybe we'd have + + align:start position:0% +on it's okay I I thought maybe we'd have + + + align:start position:0% +on it's okay I I thought maybe we'd have +time to do to look at uh intro to solar + + align:start position:0% +time to do to look at uh intro to solar + + + align:start position:0% +time to do to look at uh intro to solar +but that would have been ahead anyway oh + + align:start position:0% +but that would have been ahead anyway oh + + + align:start position:0% +but that would have been ahead anyway oh +wait no + + align:start position:0% +wait no + + + align:start position:0% +wait no +where is + + align:start position:0% + + + + align:start position:0% + +the + + align:start position:0% + + + + align:start position:0% + +view + + align:start position:0% +view + + + align:start position:0% +view +huh that's not looking very + + align:start position:0% + + + + align:start position:0% + +good I had a nice + + align:start position:0% +good I had a nice + + + align:start position:0% +good I had a nice +uh what I thought was a nice example of + + align:start position:0% +uh what I thought was a nice example of + + + align:start position:0% +uh what I thought was a nice example of +a + + align:start position:0% +a + + + align:start position:0% +a +problem no + + align:start position:0% + + + + align:start position:0% + +hang on one + + align:start position:0% + + + + align:start position:0% + +second + + align:start position:0% +second + + + align:start position:0% +second +um oh boy never show anyone your desktop + + align:start position:0% +um oh boy never show anyone your desktop + + + align:start position:0% +um oh boy never show anyone your desktop +in a + + align:start position:0% +in a + + + align:start position:0% +in a +presentation that's a bad + + align:start position:0% +presentation that's a bad + + + align:start position:0% +presentation that's a bad +idea um but anyway oh final + + align:start position:0% +idea um but anyway oh final + + + align:start position:0% +idea um but anyway oh final +quiz yeah that's from last year yeah + + align:start position:0% +quiz yeah that's from last year yeah + + + align:start position:0% +quiz yeah that's from last year yeah +don't worry it's not it's in a very safe + + align:start position:0% +don't worry it's not it's in a very safe + + + align:start position:0% +don't worry it's not it's in a very safe +location for this + + align:start position:0% +location for this + + + align:start position:0% +location for this +year actually it's very unsafe it's up + + align:start position:0% +year actually it's very unsafe it's up + + + align:start position:0% +year actually it's very unsafe it's up +here anyway uh wait where did it go + + align:start position:0% +here anyway uh wait where did it go + + + align:start position:0% +here anyway uh wait where did it go +ah why can't I see it here we + + align:start position:0% +ah why can't I see it here we + + + align:start position:0% +ah why can't I see it here we +go okay that's the problem I wanted to + + align:start position:0% +go okay that's the problem I wanted to + + + align:start position:0% +go okay that's the problem I wanted to +talk about okay so this was a problem + + align:start position:0% +talk about okay so this was a problem + + + align:start position:0% +talk about okay so this was a problem +from last year's + + align:start position:0% +from last year's + + + align:start position:0% +from last year's +quiz and + + align:start position:0% +quiz and + + + align:start position:0% +quiz and +um wa okay so your adviser has just + + align:start position:0% +um wa okay so your adviser has just + + + align:start position:0% +um wa okay so your adviser has just +spilled coffee on the culmination of + + align:start position:0% +spilled coffee on the culmination of + + + align:start position:0% +spilled coffee on the culmination of +your entire summer urra work + + align:start position:0% + + + + align:start position:0% + +this is not a true story uh the + + align:start position:0% +this is not a true story uh the + + + align:start position:0% +this is not a true story uh the +prediction of the band structure of an + + align:start position:0% +prediction of the band structure of an + + + align:start position:0% +prediction of the band structure of an +amazing new material for solar cells + + align:start position:0% +amazing new material for solar cells + + + align:start position:0% +amazing new material for solar cells +unfortunately in your excitement to show + + align:start position:0% +unfortunately in your excitement to show + + + align:start position:0% +unfortunately in your excitement to show +your work you forgot to back up your + + align:start position:0% +your work you forgot to back up your + + + align:start position:0% +your work you forgot to back up your +data you dropped your computer in a hot + + align:start position:0% +data you dropped your computer in a hot + + + align:start position:0% +data you dropped your computer in a hot +tub and you forgot everything you + + align:start position:0% +tub and you forgot everything you + + + align:start position:0% +tub and you forgot everything you +did so you only have that one print out + + align:start position:0% +did so you only have that one print out + + + align:start position:0% +did so you only have that one print out +now stained with + + align:start position:0% +now stained with + + + align:start position:0% +now stained with +coffee can you believe it this is what + + align:start position:0% +coffee can you believe it this is what + + + align:start position:0% +coffee can you believe it this is what +you got nothing + + align:start position:0% +you got nothing + + + align:start position:0% +you got nothing +else okay + + align:start position:0% +else okay + + + align:start position:0% +else okay +was this material you want to put it + + align:start position:0% +was this material you want to put it + + + align:start position:0% +was this material you want to put it +back together because you know it was 4 + + align:start position:0% +back together because you know it was 4 + + + align:start position:0% +back together because you know it was 4 +in the morning you would had a lot of + + align:start position:0% +in the morning you would had a lot of + + + align:start position:0% +in the morning you would had a lot of +noos but still you're pretty sure you + + align:start position:0% +noos but still you're pretty sure you + + + align:start position:0% +noos but still you're pretty sure you +remember it was going to change the + + align:start position:0% +remember it was going to change the + + + align:start position:0% +remember it was going to change the +whole field of solar okay now from this + + align:start position:0% +whole field of solar okay now from this + + + align:start position:0% +whole field of solar okay now from this +was this material a metal a + + align:start position:0% +was this material a metal a + + + align:start position:0% +was this material a metal a +semiconductor or an + + align:start position:0% + + + + align:start position:0% + +insulator tell me + + align:start position:0% +insulator tell me + + + align:start position:0% +insulator tell me +why really + + align:start position:0% +why really + + + align:start position:0% +why really +seriously yeah doesn't the bands are + + align:start position:0% +seriously yeah doesn't the bands are + + + align:start position:0% +seriously yeah doesn't the bands are +crossing um looks like the tallest band + + align:start position:0% +crossing um looks like the tallest band + + + align:start position:0% +crossing um looks like the tallest band +Gap is just under the zero I could can't + + align:start position:0% +Gap is just under the zero I could can't + + + align:start position:0% +Gap is just under the zero I could can't +really tell and then it doesn't look + + align:start position:0% +really tell and then it doesn't look + + + align:start position:0% +really tell and then it doesn't look +like the for the + + align:start position:0% +like the for the + + + align:start position:0% +like the for the +crossing doesn't look like it can you + + align:start position:0% +crossing doesn't look like it can you + + + align:start position:0% +crossing doesn't look like it can you +can you be certain + + align:start position:0% + + + + align:start position:0% + +no it's also solar + + align:start position:0% + + + + align:start position:0% + +cell well you do need metal you know + + align:start position:0% +cell well you do need metal you know + + + align:start position:0% +cell well you do need metal you know +maybe it was a revolution in the contact + + align:start position:0% +maybe it was a revolution in the contact + + + align:start position:0% +maybe it was a revolution in the contact +in the metal + + align:start position:0% +in the metal + + + align:start position:0% +in the metal +contact that wouldn't Revol that + + align:start position:0% +contact that wouldn't Revol that + + + align:start position:0% +contact that wouldn't Revol that +wouldn't revolutionize solar PV but + + align:start position:0% +wouldn't revolutionize solar PV but + + + align:start position:0% +wouldn't revolutionize solar PV but +still um again see we're inclined to + + align:start position:0% +still um again see we're inclined to + + + align:start position:0% +still um again see we're inclined to +want to connect these things up right + + align:start position:0% +want to connect these things up right + + + align:start position:0% +want to connect these things up right +we're sort of used to staring at silicon + + align:start position:0% +we're sort of used to staring at silicon + + + align:start position:0% +we're sort of used to staring at silicon +and we think that's going to do that + + align:start position:0% +and we think that's going to do that + + + align:start position:0% +and we think that's going to do that +but I mean it's not I don't know that + + align:start position:0% +but I mean it's not I don't know that + + + align:start position:0% +but I mean it's not I don't know that +you have enough information + + align:start position:0% +you have enough information + + + align:start position:0% +you have enough information +here okay I'm not sure you know enough + + align:start position:0% +here okay I'm not sure you know enough + + + align:start position:0% +here okay I'm not sure you know enough +about this to know that this band didn't + + align:start position:0% +about this to know that this band didn't + + + align:start position:0% +about this to know that this band didn't +actually split and one of them crossed + + align:start position:0% +actually split and one of them crossed + + + align:start position:0% +actually split and one of them crossed +up and went this + + align:start position:0% +up and went this + + + align:start position:0% +up and went this +way right how do you know now there is + + align:start position:0% +way right how do you know now there is + + + align:start position:0% +way right how do you know now there is +one thing you know it's not there's one + + align:start position:0% +one thing you know it's not there's one + + + align:start position:0% +one thing you know it's not there's one +of those three you know it's + + align:start position:0% +of those three you know it's + + + align:start position:0% +of those three you know it's +not not an insulator why + + align:start position:0% +not not an insulator why + + + align:start position:0% +not not an insulator why +not because you can make out at least + + align:start position:0% +not because you can make out at least + + + align:start position:0% +not because you can make out at least +that much that these bands you know + + align:start position:0% +that much that these bands you know + + + align:start position:0% +that much that these bands you know +they're about an Eevee or two apart they + + align:start position:0% +they're about an Eevee or two apart they + + + align:start position:0% +they're about an Eevee or two apart they +may be closer they may overlap but this + + align:start position:0% +may be closer they may overlap but this + + + align:start position:0% +may be closer they may overlap but this +not going to be an insulator right but + + align:start position:0% +not going to be an insulator right but + + + align:start position:0% +not going to be an insulator right but +you can't tell right this it's a little + + align:start position:0% +you can't tell right this it's a little + + + align:start position:0% +you can't tell right this it's a little +bit of a tricky question um you seem to + + align:start position:0% +bit of a tricky question um you seem to + + + align:start position:0% +bit of a tricky question um you seem to +remember that the material would absorb + + align:start position:0% +remember that the material would absorb + + + align:start position:0% +remember that the material would absorb +light very efficiently reconstruct the + + align:start position:0% +light very efficiently reconstruct the + + + align:start position:0% +light very efficiently reconstruct the +band structure plot that would + + align:start position:0% +band structure plot that would + + + align:start position:0% +band structure plot that would +correspond to such a + + align:start position:0% + + + + align:start position:0% + +material what are you supposed to do + + align:start position:0% + + + + align:start position:0% + +here yeah structure that's asso with + + align:start position:0% +here yeah structure that's asso with + + + align:start position:0% +here yeah structure that's asso with +some W region wav of okay you could + + align:start position:0% +some W region wav of okay you could + + + align:start position:0% +some W region wav of okay you could +certainly do that and but + + align:start position:0% +certainly do that and but + + + align:start position:0% +certainly do that and but +now um and you know in a way any band + + align:start position:0% +now um and you know in a way any band + + + align:start position:0% +now um and you know in a way any band +structure you know above the band Gap is + + align:start position:0% +structure you know above the band Gap is + + + align:start position:0% +structure you know above the band Gap is +associated with the region of light + + align:start position:0% +associated with the region of light + + + align:start position:0% +associated with the region of light +because except for the band Gap below + + align:start position:0% +because except for the band Gap below + + + align:start position:0% +because except for the band Gap below +which you cannot absorb light right as + + align:start position:0% +which you cannot absorb light right as + + + align:start position:0% +which you cannot absorb light right as +soon as you start having States you can + + align:start position:0% +soon as you start having States you can + + + align:start position:0% +soon as you start having States you can +absorb light now but the key is here it + + align:start position:0% +absorb light now but the key is here it + + + align:start position:0% +absorb light now but the key is here it +absorbs light very efficiently so what + + align:start position:0% +absorbs light very efficiently so what + + + align:start position:0% +absorbs light very efficiently so what +do I need to do in + + align:start position:0% +do I need to do in + + + align:start position:0% +do I need to do in +here yeah you got to put a direct band + + align:start position:0% +here yeah you got to put a direct band + + + align:start position:0% +here yeah you got to put a direct band +Gap in there + + align:start position:0% +Gap in there + + + align:start position:0% +Gap in there +somehow that's the key so you got to + + align:start position:0% +somehow that's the key so you got to + + + align:start position:0% +somehow that's the key so you got to +reconstruct this and it didn't matter to + + align:start position:0% +reconstruct this and it didn't matter to + + + align:start position:0% +reconstruct this and it didn't matter to +me where and there were all kinds of + + align:start position:0% +me where and there were all kinds of + + + align:start position:0% +me where and there were all kinds of +really creative curves people drew right + + align:start position:0% +really creative curves people drew right + + + align:start position:0% +really creative curves people drew right +but somewhere in here maybe this is + + align:start position:0% +but somewhere in here maybe this is + + + align:start position:0% +but somewhere in here maybe this is +going to come down a little and then go + + align:start position:0% +going to come down a little and then go + + + align:start position:0% +going to come down a little and then go +down here right and then maybe come in + + align:start position:0% +down here right and then maybe come in + + + align:start position:0% +down here right and then maybe come in +like here where you can't + + align:start position:0% +like here where you can't + + + align:start position:0% +like here where you can't +see um you know but somehow you got to + + align:start position:0% +see um you know but somehow you got to + + + align:start position:0% +see um you know but somehow you got to +try to make this a direct bang at + + align:start position:0% +try to make this a direct bang at + + + align:start position:0% +try to make this a direct bang at +Material right it's actually pretty hard + + align:start position:0% +Material right it's actually pretty hard + + + align:start position:0% +Material right it's actually pretty hard +because the stain doesn't give you a lot + + align:start position:0% +because the stain doesn't give you a lot + + + align:start position:0% +because the stain doesn't give you a lot +of room but it's actually that mirrors + + align:start position:0% +of room but it's actually that mirrors + + + align:start position:0% +of room but it's actually that mirrors +how hard it is to do that for silicon in + + align:start position:0% +how hard it is to do that for silicon in + + + align:start position:0% +how hard it is to do that for silicon in +real life the stain and silicon are + + align:start position:0% +real life the stain and silicon are + + + align:start position:0% +real life the stain and silicon are +deeply + + align:start position:0% +deeply + + + align:start position:0% +deeply +connected one minute later you realize + + align:start position:0% +connected one minute later you realize + + + align:start position:0% +connected one minute later you realize +that actually it didn't absorb light + + align:start position:0% +that actually it didn't absorb light + + + align:start position:0% +that actually it didn't absorb light +efficiently at all but instead it was a + + align:start position:0% +efficiently at all but instead it was a + + + align:start position:0% +efficiently at all but instead it was a +revolutionary metal electrode now what + + align:start position:0% +revolutionary metal electrode now what + + + align:start position:0% +revolutionary metal electrode now what +would you + + align:start position:0% +would you + + + align:start position:0% +would you +draw right okay you you'd cross it up + + align:start position:0% +draw right okay you you'd cross it up + + + align:start position:0% +draw right okay you you'd cross it up +you'd draw maybe you'd try to get a lot + + align:start position:0% +you'd draw maybe you'd try to get a lot + + + align:start position:0% +you'd draw maybe you'd try to get a lot +of Wiggles in here if you could or just + + align:start position:0% +of Wiggles in here if you could or just + + + align:start position:0% +of Wiggles in here if you could or just +certainly several Crossings right so + + align:start position:0% +certainly several Crossings right so + + + align:start position:0% +certainly several Crossings right so +that the electrons can kind of you know + + align:start position:0% +that the electrons can kind of you know + + + align:start position:0% +that the electrons can kind of you know +don't really see any Gap you can't see a + + align:start position:0% +don't really see any Gap you can't see a + + + align:start position:0% +don't really see any Gap you can't see a +gap okay so that's kind of a a nice you + + align:start position:0% +gap okay so that's kind of a a nice you + + + align:start position:0% +gap okay so that's kind of a a nice you +know problem for um and you can see it's + + align:start position:0% +know problem for um and you can see it's + + + align:start position:0% +know problem for um and you can see it's +not you know there's not there not a + + align:start position:0% +not you know there's not there not a + + + align:start position:0% +not you know there's not there not a +very long problem but it does you got to + + align:start position:0% +very long problem but it does you got to + + + align:start position:0% +very long problem but it does you got to +know a few things to answer the question + + align:start position:0% +know a few things to answer the question + + + align:start position:0% +know a few things to answer the question +about these sorts of uh topics okay so + + align:start position:0% +about these sorts of uh topics okay so + + + align:start position:0% +about these sorts of uh topics okay so +we'll do another one of those uh next + + align:start position:0% +we'll do another one of those uh next + + + align:start position:0% +we'll do another one of those uh next +Tuesday or + + align:start position:0% +Tuesday or + + + align:start position:0% +Tuesday or +two um okay now let's talk about uh wait + + align:start position:0% +two um okay now let's talk about uh wait + + + align:start position:0% +two um okay now let's talk about uh wait +where am I here + + align:start position:0% + + + + align:start position:0% + +let's talk about a few other properties + + align:start position:0% +let's talk about a few other properties + + + align:start position:0% +let's talk about a few other properties +that you can calculate um you know again + + align:start position:0% +that you can calculate um you know again + + + align:start position:0% +that you can calculate um you know again +I'm I'm not going to go into the details + + align:start position:0% +I'm I'm not going to go into the details + + + align:start position:0% +I'm I'm not going to go into the details +of Transport but this is sort of basic + + align:start position:0% +of Transport but this is sort of basic + + + align:start position:0% +of Transport but this is sort of basic +uh you know um uh double e or you know + + align:start position:0% +uh you know um uh double e or you know + + + align:start position:0% +uh you know um uh double e or you know +basic physics stuff if you put an + + align:start position:0% +basic physics stuff if you put an + + + align:start position:0% +basic physics stuff if you put an +electron in a field it's going to push + + align:start position:0% +electron in a field it's going to push + + + align:start position:0% +electron in a field it's going to push +it with a force and so the f equals ma + + align:start position:0% +it with a force and so the f equals ma + + + align:start position:0% +it with a force and so the f equals ma +of that yeah + + align:start position:0% + + + + align:start position:0% + +has energy greater than that Gap I don't + + align:start position:0% +has energy greater than that Gap I don't + + + align:start position:0% +has energy greater than that Gap I don't +you want a very small gap for electron + + align:start position:0% +you want a very small gap for electron + + + align:start position:0% +you want a very small gap for electron +or for a semiconductor uh for what + + align:start position:0% +or for a semiconductor uh for what + + + align:start position:0% +or for a semiconductor uh for what +application for solar cells uh yeah sure + + align:start position:0% +application for solar cells uh yeah sure + + + align:start position:0% +application for solar cells uh yeah sure +so that's a very good point and why who + + align:start position:0% +so that's a very good point and why who + + + align:start position:0% +so that's a very good point and why who +can tell me why you can't have a too low + + align:start position:0% +can tell me why you can't have a too low + + + align:start position:0% +can tell me why you can't have a too low +of a + + align:start position:0% +of a + + + align:start position:0% +of a +gap and I'll talk about this as we move + + align:start position:0% +gap and I'll talk about this as we move + + + align:start position:0% +gap and I'll talk about this as we move +into solar PV + + align:start position:0% +into solar PV + + + align:start position:0% +into solar PV +but is not high enough and keep hopping + + align:start position:0% +but is not high enough and keep hopping + + + align:start position:0% +but is not high enough and keep hopping +over + + align:start position:0% +over + + + align:start position:0% +over +what that wouldn't necessarily be a + + align:start position:0% +what that wouldn't necessarily be a + + + align:start position:0% +what that wouldn't necessarily be a +problem yeah you probably get saturated + + align:start position:0% +problem yeah you probably get saturated + + + align:start position:0% +problem yeah you probably get saturated +with lower + + align:start position:0% +with lower + + + align:start position:0% +with lower +energy and what's wrong with that + + align:start position:0% +energy and what's wrong with that + + + align:start position:0% +energy and what's wrong with that +though you're + + align:start position:0% + + + + align:start position:0% + +notal well that's that's that's what it + + align:start position:0% +notal well that's that's that's what it + + + align:start position:0% +notal well that's that's that's what it +is is it it actually is what sets the + + align:start position:0% +is is it it actually is what sets the + + + align:start position:0% +is is it it actually is what sets the +potential of the cell so this goes back + + align:start position:0% +potential of the cell so this goes back + + + align:start position:0% +potential of the cell so this goes back +to and it's a very good question right + + align:start position:0% +to and it's a very good question right + + + align:start position:0% +to and it's a very good question right +why not just use the lowest Gap possible + + align:start position:0% +why not just use the lowest Gap possible + + + align:start position:0% +why not just use the lowest Gap possible +right and then you'll absorb all the + + align:start position:0% +right and then you'll absorb all the + + + align:start position:0% +right and then you'll absorb all the +light or most of the light well the + + align:start position:0% +light or most of the light well the + + + align:start position:0% +light or most of the light well the +reason is that it goes back to this + + align:start position:0% +reason is that it goes back to this + + + align:start position:0% +reason is that it goes back to this +picture that when you're when you're + + align:start position:0% +picture that when you're when you're + + + align:start position:0% +picture that when you're when you're +taking photons and making them into + + align:start position:0% +taking photons and making them into + + + align:start position:0% +taking photons and making them into +electrons what you're really doing is + + align:start position:0% +electrons what you're really doing is + + + align:start position:0% +electrons what you're really doing is +you're you know it's it's again it's + + align:start position:0% +you're you know it's it's again it's + + + align:start position:0% +you're you know it's it's again it's +that pumping water analogy you're you're + + align:start position:0% +that pumping water analogy you're you're + + + align:start position:0% +that pumping water analogy you're you're +giving the electrons energy and pushing + + align:start position:0% +giving the electrons energy and pushing + + + align:start position:0% +giving the electrons energy and pushing +them up a hill now um in the Solar fuels + + align:start position:0% +them up a hill now um in the Solar fuels + + + align:start position:0% +them up a hill now um in the Solar fuels +case we're using that push to change the + + align:start position:0% +case we're using that push to change the + + + align:start position:0% +case we're using that push to change the +molecule's configuration to store energy + + align:start position:0% +molecule's configuration to store energy + + + align:start position:0% +molecule's configuration to store energy +in the solar cell case we're using that + + align:start position:0% +in the solar cell case we're using that + + + align:start position:0% +in the solar cell case we're using that +push to to get Just Energy voltage out + + align:start position:0% +push to to get Just Energy voltage out + + + align:start position:0% +push to to get Just Energy voltage out +right and um if I you know so I'd like + + align:start position:0% +right and um if I you know so I'd like + + + align:start position:0% +right and um if I you know so I'd like +to not get just a teeny teeny bit of + + align:start position:0% +to not get just a teeny teeny bit of + + + align:start position:0% +to not get just a teeny teeny bit of +voltage right I'd like to get get it up + + align:start position:0% +voltage right I'd like to get get it up + + + align:start position:0% +voltage right I'd like to get get it up +a hill now if I try to you know push it + + align:start position:0% +a hill now if I try to you know push it + + + align:start position:0% +a hill now if I try to you know push it +if I if I make my gam b band Gap such + + align:start position:0% +if I if I make my gam b band Gap such + + + align:start position:0% +if I if I make my gam b band Gap such +that I push it can only push it really + + align:start position:0% +that I push it can only push it really + + + align:start position:0% +that I push it can only push it really +really high you might think you want + + align:start position:0% +really high you might think you want + + + align:start position:0% +really high you might think you want +that but then what happens doesn't + + align:start position:0% +that but then what happens doesn't + + + align:start position:0% +that but then what happens doesn't +absorb any light right so now you have + + align:start position:0% +absorb any light right so now you have + + + align:start position:0% +absorb any light right so now you have +these two competing effects small band + + align:start position:0% +these two competing effects small band + + + align:start position:0% +these two competing effects small band +Gap to absorb the light larger band Gap + + align:start position:0% +Gap to absorb the light larger band Gap + + + align:start position:0% +Gap to absorb the light larger band Gap +to give you more potential for your C + + align:start position:0% +to give you more potential for your C + + + align:start position:0% +to give you more potential for your C +large poal + + align:start position:0% + + + + align:start position:0% + +small less but but more light and + + align:start position:0% +small less but but more light and + + + align:start position:0% +small less but but more light and +there's a sweet + + align:start position:0% +there's a sweet + + + align:start position:0% +there's a sweet +spot okay and I'll talk about that as I + + align:start position:0% +spot okay and I'll talk about that as I + + + align:start position:0% +spot okay and I'll talk about that as I +I'll talk about that a little bit on + + align:start position:0% +I'll talk about that a little bit on + + + align:start position:0% +I'll talk about that a little bit on +Tuesday okay that that is uh uh + + align:start position:0% +Tuesday okay that that is uh uh + + + align:start position:0% +Tuesday okay that that is uh uh +competing two competing attributes of + + align:start position:0% +competing two competing attributes of + + + align:start position:0% +competing two competing attributes of +solar PV that + + align:start position:0% +solar PV that + + + align:start position:0% +solar PV that +limit um you know how much energy you + + align:start position:0% +limit um you know how much energy you + + + align:start position:0% +limit um you know how much energy you +can you can get from the Sun um + + align:start position:0% +can you can get from the Sun um + + + align:start position:0% +can you can get from the Sun um +now the the so if you put an electron in + + align:start position:0% +now the the so if you put an electron in + + + align:start position:0% +now the the so if you put an electron in +a field it's going to move until it hits + + align:start position:0% +a field it's going to move until it hits + + + align:start position:0% +a field it's going to move until it hits +until you sort of hit this equilibrium + + align:start position:0% +until you sort of hit this equilibrium + + + align:start position:0% +until you sort of hit this equilibrium +point where the acceleration you know is + + align:start position:0% +point where the acceleration you know is + + + align:start position:0% +point where the acceleration you know is +is zero because it's um you know the + + align:start position:0% +is zero because it's um you know the + + + align:start position:0% +is zero because it's um you know the +force it feels is balanced by the + + align:start position:0% +force it feels is balanced by the + + + align:start position:0% +force it feels is balanced by the +scattering okay that's sort of basic um + + align:start position:0% +scattering okay that's sort of basic um + + + align:start position:0% +scattering okay that's sort of basic um +transport electron transport equations + + align:start position:0% +transport electron transport equations + + + align:start position:0% +transport electron transport equations +and so you can get an equation for the + + align:start position:0% +and so you can get an equation for the + + + align:start position:0% +and so you can get an equation for the +drift velocity of the electron or the + + align:start position:0% +drift velocity of the electron or the + + + align:start position:0% +drift velocity of the electron or the +thing that we care about a lot is this + + align:start position:0% +thing that we care about a lot is this + + + align:start position:0% +thing that we care about a lot is this +electrical conductivity right something + + align:start position:0% +electrical conductivity right something + + + align:start position:0% +electrical conductivity right something +that you can measure which is nothing + + align:start position:0% +that you can measure which is nothing + + + align:start position:0% +that you can measure which is nothing +more than the drift velocity times the + + align:start position:0% +more than the drift velocity times the + + + align:start position:0% +more than the drift velocity times the +number density that that's actually a + + align:start position:0% +number density that that's actually a + + + align:start position:0% +number density that that's actually a +hard thing to separate out but it can be + + align:start position:0% +hard thing to separate out but it can be + + + align:start position:0% +hard thing to separate out but it can be +done an experiment okay um and so the + + align:start position:0% +done an experiment okay um and so the + + + align:start position:0% +done an experiment okay um and so the +current is is that and and it's equal to + + align:start position:0% +current is is that and and it's equal to + + + align:start position:0% +current is is that and and it's equal to +the con Electro conductivity times the + + align:start position:0% +the con Electro conductivity times the + + + align:start position:0% +the con Electro conductivity times the +field now here's the thing that is + + align:start position:0% +field now here's the thing that is + + + align:start position:0% +field now here's the thing that is +actually um that equation then if you + + align:start position:0% +actually um that equation then if you + + + align:start position:0% +actually um that equation then if you +just look at these very simple sort of + + align:start position:0% +just look at these very simple sort of + + + align:start position:0% +just look at these very simple sort of +fals ma for an electron in a field that + + align:start position:0% +fals ma for an electron in a field that + + + align:start position:0% +fals ma for an electron in a field that +very simply comes down to this equation + + align:start position:0% +very simply comes down to this equation + + + align:start position:0% +very simply comes down to this equation +and here's the + + align:start position:0% +and here's the + + + align:start position:0% +and here's the +thing that + + align:start position:0% +thing that + + + align:start position:0% +thing that +mass okay what we want now is well + + align:start position:0% +mass okay what we want now is well + + + align:start position:0% +mass okay what we want now is well +what's the electron uh conductivity in + + align:start position:0% +what's the electron uh conductivity in + + + align:start position:0% +what's the electron uh conductivity in +the solid what's the electron + + align:start position:0% +the solid what's the electron + + + align:start position:0% +the solid what's the electron +conductivity in the solid and it turns + + align:start position:0% +conductivity in the solid and it turns + + + align:start position:0% +conductivity in the solid and it turns +out that that mass that's on the + + align:start position:0% +out that that mass that's on the + + + align:start position:0% +out that that mass that's on the +previous page that + + align:start position:0% +previous page that + + + align:start position:0% +previous page that +M it it becomes a kind of effective mass + + align:start position:0% +M it it becomes a kind of effective mass + + + align:start position:0% +M it it becomes a kind of effective mass +of the electron + + align:start position:0% +of the electron + + + align:start position:0% +of the electron +um that can be different + + align:start position:0% +um that can be different + + + align:start position:0% +um that can be different +than just the mass of the electron the + + align:start position:0% +than just the mass of the electron the + + + align:start position:0% +than just the mass of the electron the +standard mass of the electron the reason + + align:start position:0% +standard mass of the electron the reason + + + align:start position:0% +standard mass of the electron the reason +is that it's in this periodic Crystal + + align:start position:0% +is that it's in this periodic Crystal + + + align:start position:0% +is that it's in this periodic Crystal +remember you know the the electron is + + align:start position:0% +remember you know the the electron is + + + align:start position:0% +remember you know the the electron is +going to feel this very strange um + + align:start position:0% +going to feel this very strange um + + + align:start position:0% +going to feel this very strange um +environment when it's in a periodic + + align:start position:0% +environment when it's in a periodic + + + align:start position:0% +environment when it's in a periodic +Crystal and it's going to feel + + align:start position:0% +Crystal and it's going to feel + + + align:start position:0% +Crystal and it's going to feel +differences in its energy band and that + + align:start position:0% +differences in its energy band and that + + + align:start position:0% +differences in its energy band and that +changes what that does is it changes + + align:start position:0% +changes what that does is it changes + + + align:start position:0% +changes what that does is it changes +actually the effective mass of the + + align:start position:0% +actually the effective mass of the + + + align:start position:0% +actually the effective mass of the +electron as it's in different parts of + + align:start position:0% +electron as it's in different parts of + + + align:start position:0% +electron as it's in different parts of +kpace + + align:start position:0% +kpace + + + align:start position:0% +kpace +okay well it turns out that that effect + + align:start position:0% +okay well it turns out that that effect + + + align:start position:0% +okay well it turns out that that effect +mass is directly related to the this + + align:start position:0% +mass is directly related to the this + + + align:start position:0% +mass is directly related to the this +curvature this if you look at um I'm + + align:start position:0% +curvature this if you look at um I'm + + + align:start position:0% +curvature this if you look at um I'm +just rewriting the previous equation but + + align:start position:0% +just rewriting the previous equation but + + + align:start position:0% +just rewriting the previous equation but +now I'm putting in the band structure + + align:start position:0% +now I'm putting in the band structure + + + align:start position:0% +now I'm putting in the band structure +here these little V's are nothing more + + align:start position:0% +here these little V's are nothing more + + + align:start position:0% +here these little V's are nothing more +than the slope of e in the band + + align:start position:0% +than the slope of e in the band + + + align:start position:0% +than the slope of e in the band +structure the slope of the energy in the + + align:start position:0% +structure the slope of the energy in the + + + align:start position:0% +structure the slope of the energy in the +band structure versus K + + align:start position:0% +band structure versus K + + + align:start position:0% +band structure versus K +okay um and so so what so this is called + + align:start position:0% +okay um and so so what so this is called + + + align:start position:0% +okay um and so so what so this is called +effective Mass approximation it's an + + align:start position:0% +effective Mass approximation it's an + + + align:start position:0% +effective Mass approximation it's an +approximation + + align:start position:0% +approximation + + + align:start position:0% +approximation +but it's a pretty good one the electron + + align:start position:0% +but it's a pretty good one the electron + + + align:start position:0% +but it's a pretty good one the electron +feels a kind of different weight to it + + align:start position:0% +feels a kind of different weight to it + + + align:start position:0% +feels a kind of different weight to it +it's heavier light think about it that + + align:start position:0% +it's heavier light think about it that + + + align:start position:0% +it's heavier light think about it that +way depending on whether it's in a flat + + align:start position:0% +way depending on whether it's in a flat + + + align:start position:0% +way depending on whether it's in a flat +part of the band where it's really heavy + + align:start position:0% +part of the band where it's really heavy + + + align:start position:0% +part of the band where it's really heavy +or whether it's in a curvy part of the + + align:start position:0% +or whether it's in a curvy part of the + + + align:start position:0% +or whether it's in a curvy part of the +band where it's kind of feeling more + + align:start position:0% +band where it's kind of feeling more + + + align:start position:0% +band where it's kind of feeling more +light and bouncy okay and that changes + + align:start position:0% +light and bouncy okay and that changes + + + align:start position:0% +light and bouncy okay and that changes +the uh the + + align:start position:0% +the uh the + + + align:start position:0% +the uh the +connectivity right that can be measured + + align:start position:0% +connectivity right that can be measured + + + align:start position:0% +connectivity right that can be measured +and that so that's a really nice way + + align:start position:0% +and that so that's a really nice way + + + align:start position:0% +and that so that's a really nice way +just from the curvature of these bands + + align:start position:0% +just from the curvature of these bands + + + align:start position:0% +just from the curvature of these bands +it's a really nice way of getting a + + align:start position:0% +it's a really nice way of getting a + + + align:start position:0% +it's a really nice way of getting a +sense of how mobile an electron or ho is + + align:start position:0% +sense of how mobile an electron or ho is + + + align:start position:0% +sense of how mobile an electron or ho is +in a material all you have to do is you + + align:start position:0% +in a material all you have to do is you + + + align:start position:0% +in a material all you have to do is you +just take an integral over the second + + align:start position:0% +just take an integral over the second + + + align:start position:0% +just take an integral over the second +derivative of this uh or the derivative + + align:start position:0% +derivative of this uh or the derivative + + + align:start position:0% +derivative of this uh or the derivative +of that the slope basically as you go + + align:start position:0% +of that the slope basically as you go + + + align:start position:0% +of that the slope basically as you go +along case space there okay does any so + + align:start position:0% +along case space there okay does any so + + + align:start position:0% +along case space there okay does any so +does anybody know what a firmy function + + align:start position:0% +does anybody know what a firmy function + + + align:start position:0% +does anybody know what a firmy function +is it's just a weight but + + align:start position:0% +is it's just a weight but + + + align:start position:0% +is it's just a weight but +yeah how many of you know don't know + + align:start position:0% +yeah how many of you know don't know + + + align:start position:0% +yeah how many of you know don't know +what a firmy function is it's okay so + + align:start position:0% +what a firmy function is it's okay so + + + align:start position:0% +what a firmy function is it's okay so +it's basically you know this is this + + align:start position:0% +it's basically you know this is this + + + align:start position:0% +it's basically you know this is this +comes from fmy direct statistics it's + + align:start position:0% +comes from fmy direct statistics it's + + + align:start position:0% +comes from fmy direct statistics it's +not um in any way critical here but it's + + align:start position:0% +not um in any way critical here but it's + + + align:start position:0% +not um in any way critical here but it's +an occupation function it's saying that + + align:start position:0% +an occupation function it's saying that + + + align:start position:0% +an occupation function it's saying that +at a given + + align:start position:0% +at a given + + + align:start position:0% +at a given +temperature + + align:start position:0% +temperature + + + align:start position:0% +temperature +you're likely to have uh electrons or + + align:start position:0% +you're likely to have uh electrons or + + + align:start position:0% +you're likely to have uh electrons or +not um at at a certain energy and so the + + align:start position:0% +not um at at a certain energy and so the + + + align:start position:0% +not um at at a certain energy and so the +firmy function you know at zero + + align:start position:0% +firmy function you know at zero + + + align:start position:0% +firmy function you know at zero +temperature f is going to look like this + + align:start position:0% + + + + align:start position:0% + +where this would be one and this well + + align:start position:0% +where this would be one and this well + + + align:start position:0% +where this would be one and this well +this would be + + align:start position:0% + + + + align:start position:0% + +zero but then as and the firmy function + + align:start position:0% +zero but then as and the firmy function + + + align:start position:0% +zero but then as and the firmy function +is uh one over e to the um e minus EF / + + align:start position:0% +is uh one over e to the um e minus EF / + + + align:start position:0% +is uh one over e to the um e minus EF / +KT uh plus + + align:start position:0% +KT uh plus + + + align:start position:0% +KT uh plus +one okay where e is where you are in the + + align:start position:0% +one okay where e is where you are in the + + + align:start position:0% +one okay where e is where you are in the +band structure e is where you are in the + + align:start position:0% +band structure e is where you are in the + + + align:start position:0% +band structure e is where you are in the +band structure and you're looking at + + align:start position:0% +band structure and you're looking at + + + align:start position:0% +band structure and you're looking at +this as you go above the firmy energy + + align:start position:0% +this as you go above the firmy energy + + + align:start position:0% +this as you go above the firmy energy +can electrons be there well at zero + + align:start position:0% +can electrons be there well at zero + + + align:start position:0% +can electrons be there well at zero +temperature no right but actually when + + align:start position:0% +temperature no right but actually when + + + align:start position:0% +temperature no right but actually when +you go to some finite temperature just + + align:start position:0% +you go to some finite temperature just + + + align:start position:0% +you go to some finite temperature just +temperature alone can kick electrons up + + align:start position:0% +temperature alone can kick electrons up + + + align:start position:0% +temperature alone can kick electrons up +can kick electrons up okay that's what + + align:start position:0% +can kick electrons up okay that's what + + + align:start position:0% +can kick electrons up okay that's what +the firmy function is is in that + + align:start position:0% +the firmy function is is in that + + + align:start position:0% +the firmy function is is in that +equation for um because at some + + align:start position:0% +equation for um because at some + + + align:start position:0% +equation for um because at some +temperature you can actually have a + + align:start position:0% +temperature you can actually have a + + + align:start position:0% +temperature you can actually have a +distribution + + align:start position:0% +distribution + + + align:start position:0% +distribution +that looks more like + + align:start position:0% +that looks more like + + + align:start position:0% +that looks more like +this tal + + align:start position:0% +this tal + + + align:start position:0% +this tal +z t equals + + align:start position:0% + + + + align:start position:0% + +something now what what's important here + + align:start position:0% +something now what what's important here + + + align:start position:0% +something now what what's important here +well what's important is that you know + + align:start position:0% +well what's important is that you know + + + align:start position:0% +well what's important is that you know +when you think about um + + align:start position:0% +when you think about um + + + align:start position:0% +when you think about um +conductivity you want to know you got + + align:start position:0% +conductivity you want to know you got + + + align:start position:0% +conductivity you want to know you got +you see the difference here between you + + align:start position:0% +you see the difference here between you + + + align:start position:0% +you see the difference here between you +know drift velocity and current or + + align:start position:0% +know drift velocity and current or + + + align:start position:0% +know drift velocity and current or +conductivity is that you got to know + + align:start position:0% +conductivity is that you got to know + + + align:start position:0% +conductivity is that you got to know +something about how many carriers you + + align:start position:0% +something about how many carriers you + + + align:start position:0% +something about how many carriers you +have + + align:start position:0% +have + + + align:start position:0% +have +okay um and that's going to be + + align:start position:0% +okay um and that's going to be + + + align:start position:0% +okay um and that's going to be +temperature + + align:start position:0% +temperature + + + align:start position:0% +temperature +dependent does everybody see that that's + + align:start position:0% +dependent does everybody see that that's + + + align:start position:0% +dependent does everybody see that that's +why this is important now but what if my + + align:start position:0% +why this is important now but what if my + + + align:start position:0% +why this is important now but what if my +firmy function is like this and okay + + align:start position:0% +firmy function is like this and okay + + + align:start position:0% +firmy function is like this and okay +let's say I have silicon and I'm going + + align:start position:0% +let's say I have silicon and I'm going + + + align:start position:0% +let's say I have silicon and I'm going +to now plot on top of this um let me use + + align:start position:0% +to now plot on top of this um let me use + + + align:start position:0% +to now plot on top of this um let me use +a different color and plot on top of + + align:start position:0% +a different color and plot on top of + + + align:start position:0% +a different color and plot on top of +this the density of States okay and + + align:start position:0% +this the density of States okay and + + + align:start position:0% +this the density of States okay and +let's say my density of States was like + + align:start position:0% +let's say my density of States was like + + + align:start position:0% +let's say my density of States was like +this okay I don't know if it is or not + + align:start position:0% +this okay I don't know if it is or not + + + align:start position:0% +this okay I don't know if it is or not +and then + + align:start position:0% +and then + + + align:start position:0% +and then +here's the band + + align:start position:0% +here's the band + + + align:start position:0% +here's the band +Gap this is my + + align:start position:0% +Gap this is my + + + align:start position:0% +Gap this is my +Doss that doesn't look like a different + + align:start position:0% +Doss that doesn't look like a different + + + align:start position:0% +Doss that doesn't look like a different +color at all it's not even close it's + + align:start position:0% +color at all it's not even close it's + + + align:start position:0% +color at all it's not even close it's +like they painted it yellow on the + + align:start position:0% +like they painted it yellow on the + + + align:start position:0% +like they painted it yellow on the +outside and seriously it's totally white + + align:start position:0% +outside and seriously it's totally white + + + align:start position:0% +outside and seriously it's totally white +all right anyway + + align:start position:0% +all right anyway + + + align:start position:0% +all right anyway +so um so here's my firmy function I'm at + + align:start position:0% +so um so here's my firmy function I'm at + + + align:start position:0% +so um so here's my firmy function I'm at +room temperature and this is my + + align:start position:0% +room temperature and this is my + + + align:start position:0% +room temperature and this is my +distribution of + + align:start position:0% +distribution of + + + align:start position:0% +distribution of +electrons okay here's the um you know + + align:start position:0% +electrons okay here's the um you know + + + align:start position:0% +electrons okay here's the um you know +here's the uh this is the + + align:start position:0% + + + + align:start position:0% + +gap tell me what's going on + + align:start position:0% +gap tell me what's going on + + + align:start position:0% +gap tell me what's going on +here Somebody explain this to + + align:start position:0% + + + + align:start position:0% + +me yeah Sam even though there's + + align:start position:0% +me yeah Sam even though there's + + + align:start position:0% +me yeah Sam even though there's +probability that you can have electrons + + align:start position:0% +probability that you can have electrons + + + align:start position:0% +probability that you can have electrons +in those space because there's no space + + align:start position:0% +in those space because there's no space + + + align:start position:0% +in those space because there's no space +go + + align:start position:0% +go + + + align:start position:0% +go +I love it that's absolutely right you + + align:start position:0% +I love it that's absolutely right you + + + align:start position:0% +I love it that's absolutely right you +cannot have electrons there the firmy + + align:start position:0% +cannot have electrons there the firmy + + + align:start position:0% +cannot have electrons there the firmy +function says I + + align:start position:0% +function says I + + + align:start position:0% +function says I +can in your face fmy function says the + + align:start position:0% +can in your face fmy function says the + + + align:start position:0% +can in your face fmy function says the +Doss I didn't say that I would never say + + align:start position:0% +Doss I didn't say that I would never say + + + align:start position:0% +Doss I didn't say that I would never say +that to a fmy function but the Dos said + + align:start position:0% +that to a fmy function but the Dos said + + + align:start position:0% +that to a fmy function but the Dos said +it the do said + + align:start position:0% + + + + align:start position:0% + +uhuh we got zero probability here man + + align:start position:0% +uhuh we got zero probability here man + + + align:start position:0% +uhuh we got zero probability here man +you can't be here so the Dos said no + + align:start position:0% +you can't be here so the Dos said no + + + align:start position:0% +you can't be here so the Dos said no +States No Deal go away so the firm + + align:start position:0% +States No Deal go away so the firm + + + align:start position:0% +States No Deal go away so the firm +function tried it said hey I got enough + + align:start position:0% +function tried it said hey I got enough + + + align:start position:0% +function tried it said hey I got enough +energy from temperature to give you a + + align:start position:0% +energy from temperature to give you a + + + align:start position:0% +energy from temperature to give you a +few electrons and the do says I don't + + align:start position:0% +few electrons and the do says I don't + + + align:start position:0% +few electrons and the do says I don't +want them because they're not at the + + align:start position:0% +want them because they're not at the + + + align:start position:0% +want them because they're not at the +energy where I've got any states right + + align:start position:0% +energy where I've got any states right + + + align:start position:0% +energy where I've got any states right +now what can I do then to + + align:start position:0% +now what can I do then to + + + align:start position:0% +now what can I do then to +populate the conduction band of + + align:start position:0% +populate the conduction band of + + + align:start position:0% +populate the conduction band of +silicon what can I + + align:start position:0% + + + + align:start position:0% + +do more thermal energy I'm going to run + + align:start position:0% +do more thermal energy I'm going to run + + + align:start position:0% +do more thermal energy I'm going to run +my solar cell at 10,000 de well you + + align:start position:0% +my solar cell at 10,000 de well you + + + align:start position:0% +my solar cell at 10,000 de well you +could you'll get more and more and you + + align:start position:0% +could you'll get more and more and you + + + align:start position:0% +could you'll get more and more and you +will start to get electrons in there but + + align:start position:0% +will start to get electrons in there but + + + align:start position:0% +will start to get electrons in there but +actually that's not always + + align:start position:0% +actually that's not always + + + align:start position:0% +actually that's not always +practical so what is how do we get + + align:start position:0% +practical so what is how do we get + + + align:start position:0% +practical so what is how do we get +electrons into there then there are + + align:start position:0% +electrons into there then there are + + + align:start position:0% +electrons into there then there are +other reasons electrons come into those + + align:start position:0% +other reasons electrons come into those + + + align:start position:0% +other reasons electrons come into those +States you know but but what not just + + align:start position:0% +States you know but but what not just + + + align:start position:0% +States you know but but what not just +from thermal um but what's one way that + + align:start position:0% +from thermal um but what's one way that + + + align:start position:0% +from thermal um but what's one way that +we can get electrons in + + align:start position:0% + + + + align:start position:0% + +there yeah what does doping do + + align:start position:0% + + + + align:start position:0% + +well it can change the fir energy + + align:start position:0% +well it can change the fir energy + + + align:start position:0% +well it can change the fir energy +but what might I dope silicon + + align:start position:0% +but what might I dope silicon + + + align:start position:0% +but what might I dope silicon +with phosphorus + + align:start position:0% +with phosphorus + + + align:start position:0% +with phosphorus +why excess electron compared to Silicon + + align:start position:0% +why excess electron compared to Silicon + + + align:start position:0% +why excess electron compared to Silicon +now if I have an excess + + align:start position:0% +now if I have an excess + + + align:start position:0% +now if I have an excess +electron sitting in my crystal then is + + align:start position:0% +electron sitting in my crystal then is + + + align:start position:0% +electron sitting in my crystal then is +it you know and and but really the + + align:start position:0% +it you know and and but really the + + + align:start position:0% +it you know and and but really the +crystal is still kind of + + align:start position:0% +crystal is still kind of + + + align:start position:0% +crystal is still kind of +silicon cuz I don't have many of these + + align:start position:0% +silicon cuz I don't have many of these + + + align:start position:0% +silicon cuz I don't have many of these +excess electrons I just have one + + align:start position:0% +excess electrons I just have one + + + align:start position:0% +excess electrons I just have one +phosphorus atom every thousand so it's + + align:start position:0% +phosphorus atom every thousand so it's + + + align:start position:0% +phosphorus atom every thousand so it's +really still silicon then but I filled + + align:start position:0% +really still silicon then but I filled + + + align:start position:0% +really still silicon then but I filled +all my electrons up to here and now I've + + align:start position:0% +all my electrons up to here and now I've + + + align:start position:0% +all my electrons up to here and now I've +got one extra where does it + + align:start position:0% +got one extra where does it + + + align:start position:0% +got one extra where does it +go goes in there and now I'm populating + + align:start position:0% +go goes in there and now I'm populating + + + align:start position:0% +go goes in there and now I'm populating +it without thermal energy right I don't + + align:start position:0% +it without thermal energy right I don't + + + align:start position:0% +it without thermal energy right I don't +need to work with my firy function I did + + align:start position:0% +need to work with my firy function I did + + + align:start position:0% +need to work with my firy function I did +it chemically I put in I put an atom in + + align:start position:0% +it chemically I put in I put an atom in + + + align:start position:0% +it chemically I put in I put an atom in +there that had a spare electron right + + align:start position:0% +there that had a spare electron right + + + align:start position:0% +there that had a spare electron right +and that is actually in fact exactly + + align:start position:0% +and that is actually in fact exactly + + + align:start position:0% +and that is actually in fact exactly +what happened + + align:start position:0% +what happened + + + align:start position:0% +what happened +in in you know in real materials who + + align:start position:0% +in in you know in real materials who + + + align:start position:0% +in in you know in real materials who +knows what it's called when you have an + + align:start position:0% +knows what it's called when you have an + + + align:start position:0% +knows what it's called when you have an +extra electron or an excess of + + align:start position:0% +extra electron or an excess of + + + align:start position:0% +extra electron or an excess of +electrons n + + align:start position:0% +electrons n + + + align:start position:0% +electrons n +type now what if I wanted holes what if + + align:start position:0% +type now what if I wanted holes what if + + + align:start position:0% +type now what if I wanted holes what if +I wanted extra + + align:start position:0% +I wanted extra + + + align:start position:0% +I wanted extra +holes B + + align:start position:0% +holes B + + + align:start position:0% +holes B +type and what would I put in + + align:start position:0% +type and what would I put in + + + align:start position:0% +type and what would I put in +there Boron + + align:start position:0% + + + + align:start position:0% + +because less electron now you could you + + align:start position:0% +because less electron now you could you + + + align:start position:0% +because less electron now you could you +could dope it with many other things you + + align:start position:0% +could dope it with many other things you + + + align:start position:0% +could dope it with many other things you +don't have to dope silicon with just you + + align:start position:0% +don't have to dope silicon with just you + + + align:start position:0% +don't have to dope silicon with just you +know uh phosphorus or Boron it turns out + + align:start position:0% +know uh phosphorus or Boron it turns out + + + align:start position:0% +know uh phosphorus or Boron it turns out +that those are easy and and there some + + align:start position:0% +that those are easy and and there some + + + align:start position:0% +that those are easy and and there some +advantages in terms of the processing + + align:start position:0% +advantages in terms of the processing + + + align:start position:0% +advantages in terms of the processing +and you know chemically they can be + + align:start position:0% +and you know chemically they can be + + + align:start position:0% +and you know chemically they can be +happy but there are many ways of doping + + align:start position:0% +happy but there are many ways of doping + + + align:start position:0% +happy but there are many ways of doping +materials many many ways of doping + + align:start position:0% +materials many many ways of doping + + + align:start position:0% +materials many many ways of doping +materials and one of the things you do + + align:start position:0% +materials and one of the things you do + + + align:start position:0% +materials and one of the things you do +with doping there are many things you do + + align:start position:0% +with doping there are many things you do + + + align:start position:0% +with doping there are many things you do +with doping but one of the things you do + + align:start position:0% +with doping but one of the things you do + + + align:start position:0% +with doping but one of the things you do +is you get electrons or holes into these + + align:start position:0% +is you get electrons or holes into these + + + align:start position:0% +is you get electrons or holes into these +bands you populate them right but this + + align:start position:0% +bands you populate them right but this + + + align:start position:0% +bands you populate them right but this +expression is ignoring that this is just + + align:start position:0% +expression is ignoring that this is just + + + align:start position:0% +expression is ignoring that this is just +saying well we're going to use we're + + align:start position:0% +saying well we're going to use we're + + + align:start position:0% +saying well we're going to use we're +going to see if there's some thermal uh + + align:start position:0% +going to see if there's some thermal uh + + + align:start position:0% +going to see if there's some thermal uh +uh energy there and we'll use that + + align:start position:0% +uh energy there and we'll use that + + + align:start position:0% +uh energy there and we'll use that +okay + + align:start position:0% + + + + align:start position:0% + +yeah any questions about that now um we + + align:start position:0% +yeah any questions about that now um we + + + align:start position:0% +yeah any questions about that now um we +talked about this a lot so I'm not going + + align:start position:0% +talked about this a lot so I'm not going + + + align:start position:0% +talked about this a lot so I'm not going +to go over this again that you know the + + align:start position:0% +to go over this again that you know the + + + align:start position:0% +to go over this again that you know the +direct transitions are easy for + + align:start position:0% +direct transitions are easy for + + + align:start position:0% +direct transitions are easy for +photons um the indirect ones where you + + align:start position:0% +photons um the indirect ones where you + + + align:start position:0% +photons um the indirect ones where you +shift the K where you are in kpace are + + align:start position:0% +shift the K where you are in kpace are + + + align:start position:0% +shift the K where you are in kpace are +hard okay um and that is why + + align:start position:0% +hard okay um and that is why + + + align:start position:0% +hard okay um and that is why +silicon is an expensive solar cell so + + align:start position:0% +silicon is an expensive solar cell so + + + align:start position:0% +silicon is an expensive solar cell so +we' we've talked about this I don't want + + align:start position:0% +we' we've talked about this I don't want + + + align:start position:0% +we' we've talked about this I don't want +to BL labor the point because I want to + + align:start position:0% +to BL labor the point because I want to + + + align:start position:0% +to BL labor the point because I want to +try to get to some + + align:start position:0% +try to get to some + + + align:start position:0% +try to get to some +simulations if possible any questions + + align:start position:0% +simulations if possible any questions + + + align:start position:0% +simulations if possible any questions +about that point though the optical + + align:start position:0% + + + + align:start position:0% + +transitions right so the kinds of things + + align:start position:0% +transitions right so the kinds of things + + + align:start position:0% +transitions right so the kinds of things +you can get well you can get Optical + + align:start position:0% +you can get well you can get Optical + + + align:start position:0% +you can get well you can get Optical +properties + + align:start position:0% +properties + + + align:start position:0% +properties +right + + align:start position:0% +right + + + align:start position:0% +right +um and you can also get magnetic + + align:start position:0% +um and you can also get magnetic + + + align:start position:0% +um and you can also get magnetic +properties from these densities of + + align:start position:0% +properties from these densities of + + + align:start position:0% +properties from these densities of +States so we talked about the optical + + align:start position:0% +States so we talked about the optical + + + align:start position:0% +States so we talked about the optical +properties and the optical properties is + + align:start position:0% +properties and the optical properties is + + + align:start position:0% +properties and the optical properties is +really the the the context of your um + + align:start position:0% +really the the the context of your um + + + align:start position:0% +really the the the context of your um +you know of your P set 5 but it's for a + + align:start position:0% +you know of your P set 5 but it's for a + + + align:start position:0% +you know of your P set 5 but it's for a +molecule + + align:start position:0% +molecule + + + align:start position:0% +molecule +um we haven't talked about magnetism and + + align:start position:0% +um we haven't talked about magnetism and + + + align:start position:0% +um we haven't talked about magnetism and +I want to come back to it because I did + + align:start position:0% +I want to come back to it because I did + + + align:start position:0% +I want to come back to it because I did +mention that electrons have Spin and + + align:start position:0% +mention that electrons have Spin and + + + align:start position:0% +mention that electrons have Spin and +therefore um they also have a magnetic + + align:start position:0% +therefore um they also have a magnetic + + + align:start position:0% +therefore um they also have a magnetic +moment and we call this just think of it + + align:start position:0% +moment and we call this just think of it + + + align:start position:0% +moment and we call this just think of it +as some constant that we call a bore + + align:start position:0% +as some constant that we call a bore + + + align:start position:0% +as some constant that we call a bore +Magneton it has a value + + align:start position:0% +Magneton it has a value + + + align:start position:0% +Magneton it has a value +okay um well and if you think about like + + align:start position:0% +okay um well and if you think about like + + + align:start position:0% +okay um well and if you think about like +an atom or a molecule you could just get + + align:start position:0% +an atom or a molecule you could just get + + + align:start position:0% +an atom or a molecule you could just get +that by knowing how many electrons are + + align:start position:0% +that by knowing how many electrons are + + + align:start position:0% +that by knowing how many electrons are +spinning in One Direction More than the + + align:start position:0% +spinning in One Direction More than the + + + align:start position:0% +spinning in One Direction More than the +other right so you can just count how + + align:start position:0% +other right so you can just count how + + + align:start position:0% +other right so you can just count how +many spin up electrons minus how many + + align:start position:0% +many spin up electrons minus how many + + + align:start position:0% +many spin up electrons minus how many +spin down electrons um you have and + + align:start position:0% +spin down electrons um you have and + + + align:start position:0% +spin down electrons um you have and +multiply that by the board Magneton and + + align:start position:0% +multiply that by the board Magneton and + + + align:start position:0% +multiply that by the board Magneton and +that'll give you the Magnetic Moment of + + align:start position:0% +that'll give you the Magnetic Moment of + + + align:start position:0% +that'll give you the Magnetic Moment of +the atom or molecule but what would I do + + align:start position:0% +the atom or molecule but what would I do + + + align:start position:0% +the atom or molecule but what would I do +for a solid + + align:start position:0% +for a solid + + + align:start position:0% +for a solid +so just like just like um do I still + + align:start position:0% +so just like just like um do I still + + + align:start position:0% +so just like just like um do I still +have it yeah see there's a there's the + + align:start position:0% +have it yeah see there's a there's the + + + align:start position:0% +have it yeah see there's a there's the +atomic picture where I could just count + + align:start position:0% +atomic picture where I could just count + + + align:start position:0% +atomic picture where I could just count +and in this case the difference is + + align:start position:0% +and in this case the difference is + + + align:start position:0% +and in this case the difference is +three right but now I've got a solid so + + align:start position:0% +three right but now I've got a solid so + + + align:start position:0% +three right but now I've got a solid so +what do I want to + + align:start position:0% + + + + align:start position:0% + +do I want to what what do I want to look + + align:start position:0% +do I want to what what do I want to look + + + align:start position:0% +do I want to what what do I want to look +at for a + + align:start position:0% +at for a + + + align:start position:0% +at for a +solid states density of states and it + + align:start position:0% +solid states density of states and it + + + align:start position:0% +solid states density of states and it +turns out that you can plot the density + + align:start position:0% +turns out that you can plot the density + + + align:start position:0% +turns out that you can plot the density +of states for spin up and spin down + + align:start position:0% +of states for spin up and spin down + + + align:start position:0% +of states for spin up and spin down +electrons + + align:start position:0% +electrons + + + align:start position:0% +electrons +separately and they can be different + + align:start position:0% +separately and they can be different + + + align:start position:0% +separately and they can be different +they can occupy those uh the two spins + + align:start position:0% +they can occupy those uh the two spins + + + align:start position:0% +they can occupy those uh the two spins +differently in a more complicated way + + align:start position:0% +differently in a more complicated way + + + align:start position:0% +differently in a more complicated way +but very much kind of same idea as what + + align:start position:0% +but very much kind of same idea as what + + + align:start position:0% +but very much kind of same idea as what +can happen in an atom but it's more + + align:start position:0% +can happen in an atom but it's more + + + align:start position:0% +can happen in an atom but it's more +complicated as you get these curvy bands + + align:start position:0% +complicated as you get these curvy bands + + + align:start position:0% +complicated as you get these curvy bands +and and all kinds of other things that + + align:start position:0% +and and all kinds of other things that + + + align:start position:0% +and and all kinds of other things that +can happen in a solid so now you look at + + align:start position:0% +can happen in a solid so now you look at + + + align:start position:0% +can happen in a solid so now you look at +the separate density of states for + + align:start position:0% +the separate density of states for + + + align:start position:0% +the separate density of states for +electrons with spin up versus spin down + + align:start position:0% +electrons with spin up versus spin down + + + align:start position:0% +electrons with spin up versus spin down +and that is something that I didn't talk + + align:start position:0% +and that is something that I didn't talk + + + align:start position:0% +and that is something that I didn't talk +about yet it's an input + + align:start position:0% +about yet it's an input + + + align:start position:0% +about yet it's an input +parameter in Siesta that is checked yes + + align:start position:0% +parameter in Siesta that is checked yes + + + align:start position:0% +parameter in Siesta that is checked yes +by default and it's called spin + + align:start position:0% +by default and it's called spin + + + align:start position:0% +by default and it's called spin +polarized question mark I think is what + + align:start position:0% +polarized question mark I think is what + + + align:start position:0% +polarized question mark I think is what +it's called spin polarized I should give + + align:start position:0% +it's called spin polarized I should give + + + align:start position:0% +it's called spin polarized I should give +the right intonation and you say yes or + + align:start position:0% +the right intonation and you say yes or + + + align:start position:0% +the right intonation and you say yes or +no and you say yes because that's the + + align:start position:0% +no and you say yes because that's the + + + align:start position:0% +no and you say yes because that's the +default but what are you doing when you + + align:start position:0% +default but what are you doing when you + + + align:start position:0% +default but what are you doing when you +say yes well what you're doing is you're + + align:start position:0% +say yes well what you're doing is you're + + + align:start position:0% +say yes well what you're doing is you're +telling the calculation to to allow the + + align:start position:0% +telling the calculation to to allow the + + + align:start position:0% +telling the calculation to to allow the +up and down electrons to have freedom + + align:start position:0% +up and down electrons to have freedom + + + align:start position:0% +up and down electrons to have freedom +from one another okay that's actually + + align:start position:0% +from one another okay that's actually + + + align:start position:0% +from one another okay that's actually +critical so if you didn't do that you + + align:start position:0% +critical so if you didn't do that you + + + align:start position:0% +critical so if you didn't do that you +would be simulating the material with + + align:start position:0% +would be simulating the material with + + + align:start position:0% +would be simulating the material with +the + + align:start position:0% +the + + + align:start position:0% +the +constraint that the up and down + + align:start position:0% +constraint that the up and down + + + align:start position:0% +constraint that the up and down +electrons are exactly at the same + + align:start position:0% +electrons are exactly at the same + + + align:start position:0% +electrons are exactly at the same +energies okay so spin polarized it's + + align:start position:0% +energies okay so spin polarized it's + + + align:start position:0% +energies okay so spin polarized it's +it's a it's a the reason you do uh + + align:start position:0% +it's a it's a the reason you do uh + + + align:start position:0% +it's a it's a the reason you do uh +calculations that are not spin polarized + + align:start position:0% +calculations that are not spin polarized + + + align:start position:0% +calculations that are not spin polarized +is because many systems don't have a + + align:start position:0% +is because many systems don't have a + + + align:start position:0% +is because many systems don't have a +difference between up and down electrons + + align:start position:0% +difference between up and down electrons + + + align:start position:0% +difference between up and down electrons +right and and they are actually all the + + align:start position:0% +right and and they are actually all the + + + align:start position:0% +right and and they are actually all the +same right I mean you know if I looked + + align:start position:0% +same right I mean you know if I looked + + + align:start position:0% +same right I mean you know if I looked +at if I filled this up what do I have if + + align:start position:0% +at if I filled this up what do I have if + + + align:start position:0% +at if I filled this up what do I have if +I fill this up + + align:start position:0% +I fill this up + + + align:start position:0% +I fill this up +oh What atom is + + align:start position:0% +oh What atom is + + + align:start position:0% +oh What atom is +that it's + + align:start position:0% +that it's + + + align:start position:0% +that it's +neon and here every up electron is the + + align:start position:0% +neon and here every up electron is the + + + align:start position:0% +neon and here every up electron is the +same as every down electron for a given + + align:start position:0% +same as every down electron for a given + + + align:start position:0% +same as every down electron for a given +state right everything is the same here + + align:start position:0% +state right everything is the same here + + + align:start position:0% +state right everything is the same here +so it's not like this up + + align:start position:0% +so it's not like this up + + + align:start position:0% +so it's not like this up +electron of this p orbital wanted to be + + align:start position:0% +electron of this p orbital wanted to be + + + align:start position:0% +electron of this p orbital wanted to be +there and the down one wanted to be + + align:start position:0% +there and the down one wanted to be + + + align:start position:0% +there and the down one wanted to be +there that doesn't happen for neon and + + align:start position:0% +there that doesn't happen for neon and + + + align:start position:0% +there that doesn't happen for neon and +it doesn't happen for many systems and + + align:start position:0% +it doesn't happen for many systems and + + + align:start position:0% +it doesn't happen for many systems and +many materials but for certainly in some + + align:start position:0% +many materials but for certainly in some + + + align:start position:0% +many materials but for certainly in some +cases and certainly for magnetic + + align:start position:0% +cases and certainly for magnetic + + + align:start position:0% +cases and certainly for magnetic +materials that's what causes + + align:start position:0% +materials that's what causes + + + align:start position:0% +materials that's what causes +magnetism right it's that you have a + + align:start position:0% +magnetism right it's that you have a + + + align:start position:0% +magnetism right it's that you have a +difference between Spin up and spin down + + align:start position:0% +difference between Spin up and spin down + + + align:start position:0% +difference between Spin up and spin down +and that as you occupy the density of + + align:start position:0% +and that as you occupy the density of + + + align:start position:0% +and that as you occupy the density of +States you literally you get a + + align:start position:0% +States you literally you get a + + + align:start position:0% +States you literally you get a +difference in in the number right + + align:start position:0% +difference in in the number right + + + align:start position:0% +difference in in the number right +so that's what causes the + + align:start position:0% +so that's what causes the + + + align:start position:0% +so that's what causes the +magnetism so for for many materials you + + align:start position:0% +magnetism so for for many materials you + + + align:start position:0% +magnetism so for for many materials you +know there is no spin polarization or + + align:start position:0% +know there is no spin polarization or + + + align:start position:0% +know there is no spin polarization or +there or in other words there is no + + align:start position:0% +there or in other words there is no + + + align:start position:0% +there or in other words there is no +difference they they're just spin up and + + align:start position:0% +difference they they're just spin up and + + + align:start position:0% +difference they they're just spin up and +spin down is the same here same here + + align:start position:0% +spin down is the same here same here + + + align:start position:0% +spin down is the same here same here +same here right but if it's a magnetic + + align:start position:0% +same here right but if it's a magnetic + + + align:start position:0% +same here right but if it's a magnetic +material what you'll find is that if you + + align:start position:0% +material what you'll find is that if you + + + align:start position:0% +material what you'll find is that if you +plot the density of States separately + + align:start position:0% +plot the density of States separately + + + align:start position:0% +plot the density of States separately +for spin up and spin down electrons like + + align:start position:0% +for spin up and spin down electrons like + + + align:start position:0% +for spin up and spin down electrons like +in this case for for iron there's a + + align:start position:0% +in this case for for iron there's a + + + align:start position:0% +in this case for for iron there's a +difference and in fact the magnetic + + align:start position:0% +difference and in fact the magnetic + + + align:start position:0% +difference and in fact the magnetic +moment of that material is nothing more + + align:start position:0% +moment of that material is nothing more + + + align:start position:0% +moment of that material is nothing more +than the integral of that + + align:start position:0% +than the integral of that + + + align:start position:0% +than the integral of that +difference right again you're + + align:start position:0% +difference right again you're + + + align:start position:0% +difference right again you're +integrating the + + align:start position:0% +integrating the + + + align:start position:0% +integrating the +Doss and you're finding something really + + align:start position:0% +Doss and you're finding something really + + + align:start position:0% +Doss and you're finding something really +cool about the + + align:start position:0% +cool about the + + + align:start position:0% +cool about the +material okay so that's the same thing + + align:start position:0% +material okay so that's the same thing + + + align:start position:0% +material okay so that's the same thing +as just counting number of up and number + + align:start position:0% +as just counting number of up and number + + + align:start position:0% +as just counting number of up and number +of down but now you're counting it in in + + align:start position:0% +of down but now you're counting it in in + + + align:start position:0% +of down but now you're counting it in in +this very sort of complex filling of + + align:start position:0% +this very sort of complex filling of + + + align:start position:0% +this very sort of complex filling of +States you know that happens in a + + align:start position:0% +States you know that happens in a + + + align:start position:0% +States you know that happens in a +material + + align:start position:0% +material + + + align:start position:0% +material +okay any questions + + align:start position:0% +okay any questions + + + align:start position:0% +okay any questions +so if I if I did a calculation of iron + + align:start position:0% +so if I if I did a calculation of iron + + + align:start position:0% +so if I if I did a calculation of iron +with spin polarized checked no then um + + align:start position:0% +with spin polarized checked no then um + + + align:start position:0% +with spin polarized checked no then um +you see these would be identical and I'd + + align:start position:0% +you see these would be identical and I'd + + + align:start position:0% +you see these would be identical and I'd +get no + + align:start position:0% +get no + + + align:start position:0% +get no +magnetism okay and you can do that you + + align:start position:0% +magnetism okay and you can do that you + + + align:start position:0% +magnetism okay and you can do that you +can actually do the calculation of iron + + align:start position:0% +can actually do the calculation of iron + + + align:start position:0% +can actually do the calculation of iron +with spin polarized check no and it's + + align:start position:0% +with spin polarized check no and it's + + + align:start position:0% +with spin polarized check no and it's +completely wrong it's not the ground + + align:start position:0% +completely wrong it's not the ground + + + align:start position:0% +completely wrong it's not the ground +state of iron right um and but and if + + align:start position:0% +state of iron right um and but and if + + + align:start position:0% +state of iron right um and but and if +you do it with spin polarized on then it + + align:start position:0% +you do it with spin polarized on then it + + + align:start position:0% +you do it with spin polarized on then it +allows those up and down electrons to + + align:start position:0% +allows those up and down electrons to + + + align:start position:0% +allows those up and down electrons to +move relative to each other and you'll + + align:start position:0% +move relative to each other and you'll + + + align:start position:0% +move relative to each other and you'll +get uh the code will the outputs you'll + + align:start position:0% +get uh the code will the outputs you'll + + + align:start position:0% +get uh the code will the outputs you'll +see that there's a in the plots there's + + align:start position:0% +see that there's a in the plots there's + + + align:start position:0% +see that there's a in the plots there's +something called the projected density + + align:start position:0% +something called the projected density + + + align:start position:0% +something called the projected density +of States and it's projected for one + + align:start position:0% +of States and it's projected for one + + + align:start position:0% +of States and it's projected for one +Spin and another spin okay and that + + align:start position:0% +Spin and another spin okay and that + + + align:start position:0% +Spin and another spin okay and that +would allow you to um to calculate the + + align:start position:0% +would allow you to um to calculate the + + + align:start position:0% +would allow you to um to calculate the +magnetic properties and materials using + + align:start position:0% +magnetic properties and materials using + + + align:start position:0% +magnetic properties and materials using +the the nanohub tool and I think last + + align:start position:0% +the the nanohub tool and I think last + + + align:start position:0% +the the nanohub tool and I think last +year we did do uh we might have done a + + align:start position:0% +year we did do uh we might have done a + + + align:start position:0% +year we did do uh we might have done a +homework on that but this year we we + + align:start position:0% +homework on that but this year we we + + + align:start position:0% +homework on that but this year we we +won't but I want you to know about about + + align:start position:0% +won't but I want you to know about about + + + align:start position:0% +won't but I want you to know about about +it cuz it's it's kind of + + align:start position:0% +it cuz it's it's kind of + + + align:start position:0% +it cuz it's it's kind of +cool okay um any + + align:start position:0% + + + + align:start position:0% + +questions uh couple other things you can + + align:start position:0% +questions uh couple other things you can + + + align:start position:0% +questions uh couple other things you can +do and and I I you know these are just I + + align:start position:0% +do and and I I you know these are just I + + + align:start position:0% +do and and I I you know these are just I +just briefly one to First principles + + align:start position:0% +just briefly one to First principles + + + align:start position:0% +just briefly one to First principles +right Quantum molecular Dynamics you can + + align:start position:0% +right Quantum molecular Dynamics you can + + + align:start position:0% +right Quantum molecular Dynamics you can +do it you can do MD just like you did MD + + align:start position:0% +do it you can do MD just like you did MD + + + align:start position:0% +do it you can do MD just like you did MD +in the first part you're just getting F + + align:start position:0% +in the first part you're just getting F + + + align:start position:0% +in the first part you're just getting F +from uh Helman fan the Helman fan + + align:start position:0% +from uh Helman fan the Helman fan + + + align:start position:0% +from uh Helman fan the Helman fan +theorem which I sort of referred to a + + align:start position:0% +theorem which I sort of referred to a + + + align:start position:0% +theorem which I sort of referred to a +couple lectures ago um but it's + + align:start position:0% +couple lectures ago um but it's + + + align:start position:0% +couple lectures ago um but it's +basically just a way of getting the + + align:start position:0% +basically just a way of getting the + + + align:start position:0% +basically just a way of getting the +forces + + align:start position:0% +forces + + + align:start position:0% +forces +um using quantum mechanics and and I + + align:start position:0% +um using quantum mechanics and and I + + + align:start position:0% +um using quantum mechanics and and I +don't really want to go into it in + + align:start position:0% +don't really want to go into it in + + + align:start position:0% +don't really want to go into it in +detail but I just want to tell you you + + align:start position:0% +detail but I just want to tell you you + + + align:start position:0% +detail but I just want to tell you you +can get the force on these atoms from + + align:start position:0% +can get the force on these atoms from + + + align:start position:0% +can get the force on these atoms from +these quantum mechanical simulations and + + align:start position:0% +these quantum mechanical simulations and + + + align:start position:0% +these quantum mechanical simulations and +you can do Dynamics here's one I did a + + align:start position:0% +you can do Dynamics here's one I did a + + + align:start position:0% +you can do Dynamics here's one I did a +long time ago and here the problem was + + align:start position:0% +long time ago and here the problem was + + + align:start position:0% +long time ago and here the problem was +that how do nanot tubes grow was was a + + align:start position:0% +that how do nanot tubes grow was was a + + + align:start position:0% +that how do nanot tubes grow was was a +big question okay and so what we did is + + align:start position:0% +big question okay and so what we did is + + + align:start position:0% +big question okay and so what we did is +you know now what you have is you have a + + align:start position:0% +you know now what you have is you have a + + + align:start position:0% +you know now what you have is you have a +piece of iron + + align:start position:0% +piece of iron + + + align:start position:0% +piece of iron +here and this is what happens when you + + align:start position:0% +here and this is what happens when you + + + align:start position:0% +here and this is what happens when you +when you grow nanot tubes is you have + + align:start position:0% +when you grow nanot tubes is you have + + + align:start position:0% +when you grow nanot tubes is you have +these seed particles like iron right can + + align:start position:0% +these seed particles like iron right can + + + align:start position:0% +these seed particles like iron right can +be other things nickel other things will + + align:start position:0% +be other things nickel other things will + + + align:start position:0% +be other things nickel other things will +work um not gold uh and and then you + + align:start position:0% +work um not gold uh and and then you + + + align:start position:0% +work um not gold uh and and then you +flow some kind of gas over it that dumps + + align:start position:0% +flow some kind of gas over it that dumps + + + align:start position:0% +flow some kind of gas over it that dumps +carbon onto the Catalyst okay now the + + align:start position:0% +carbon onto the Catalyst okay now the + + + align:start position:0% +carbon onto the Catalyst okay now the +the the problem is that understanding + + align:start position:0% +the the problem is that understanding + + + align:start position:0% +the the problem is that understanding +how that then leads to the growth of a + + align:start position:0% +how that then leads to the growth of a + + + align:start position:0% +how that then leads to the growth of a +tube is is still an open question by the + + align:start position:0% +tube is is still an open question by the + + + align:start position:0% +tube is is still an open question by the +way still an open question nobody + + align:start position:0% +way still an open question nobody + + + align:start position:0% +way still an open question nobody +actually really knows the full answer to + + align:start position:0% +actually really knows the full answer to + + + align:start position:0% +actually really knows the full answer to +that but certainly people were just + + align:start position:0% +that but certainly people were just + + + align:start position:0% +that but certainly people were just +debating does the carbon go inside the + + align:start position:0% +debating does the carbon go inside the + + + align:start position:0% +debating does the carbon go inside the +the Catalyst or not does it stay on the + + align:start position:0% +the Catalyst or not does it stay on the + + + align:start position:0% +the Catalyst or not does it stay on the +surface does it saturate the Catalyst + + align:start position:0% +surface does it saturate the Catalyst + + + align:start position:0% +surface does it saturate the Catalyst +first and then come out you know from + + align:start position:0% +first and then come out you know from + + + align:start position:0% +first and then come out you know from +the the bulk from the particle and that + + align:start position:0% +the the bulk from the particle and that + + + align:start position:0% +the the bulk from the particle and that +that's a really that's a perfect problem + + align:start position:0% +that's a really that's a perfect problem + + + align:start position:0% +that's a really that's a perfect problem +for Quantum because there's so many + + align:start position:0% +for Quantum because there's so many + + + align:start position:0% +for Quantum because there's so many +different bonding environments and so + + align:start position:0% +different bonding environments and so + + + align:start position:0% +different bonding environments and so +many possibilities here that classical + + align:start position:0% +many possibilities here that classical + + + align:start position:0% +many possibilities here that classical +potentials will fail okay they're not + + align:start position:0% +potentials will fail okay they're not + + + align:start position:0% +potentials will fail okay they're not +going to capture all of the different + + align:start position:0% +going to capture all of the different + + + align:start position:0% +going to capture all of the different +you know complexities in how carbon + + align:start position:0% +you know complexities in how carbon + + + align:start position:0% +you know complexities in how carbon +needs to bond to iron inside and out and + + align:start position:0% +needs to bond to iron inside and out and + + + align:start position:0% +needs to bond to iron inside and out and +so it's a great problem for quantum + + align:start position:0% +so it's a great problem for quantum + + + align:start position:0% +so it's a great problem for quantum +mechanics and we studied this and showed + + align:start position:0% +mechanics and we studied this and showed + + + align:start position:0% +mechanics and we studied this and showed +you know we we fed the simulation carbon + + align:start position:0% +you know we we fed the simulation carbon + + + align:start position:0% +you know we we fed the simulation carbon +and we just watched sort of how the tube + + align:start position:0% +and we just watched sort of how the tube + + + align:start position:0% +and we just watched sort of how the tube +um winds up making its way uh out of the + + align:start position:0% +um winds up making its way uh out of the + + + align:start position:0% +um winds up making its way uh out of the +system and we show that it doesn't + + align:start position:0% +system and we show that it doesn't + + + align:start position:0% +system and we show that it doesn't +saturate actually inside the the iron + + align:start position:0% +saturate actually inside the the iron + + + align:start position:0% +saturate actually inside the the iron +but rather stays on the surface now one + + align:start position:0% +but rather stays on the surface now one + + + align:start position:0% +but rather stays on the surface now one +and it makes for cool movies + + align:start position:0% +and it makes for cool movies + + + align:start position:0% +and it makes for cool movies +um yeah I don't know how long it's so + + align:start position:0% +um yeah I don't know how long it's so + + + align:start position:0% +um yeah I don't know how long it's so +somebody tell me something you notice + + align:start position:0% +somebody tell me something you notice + + + align:start position:0% +somebody tell me something you notice +about this um besides just you know it's + + align:start position:0% +about this um besides just you know it's + + + align:start position:0% +about this um besides just you know it's +kind of a fun movie + + align:start position:0% +kind of a fun movie + + + align:start position:0% +kind of a fun movie +but do you notice anything like there's + + align:start position:0% +but do you notice anything like there's + + + align:start position:0% +but do you notice anything like there's +the initial nanot tube growth and that's + + align:start position:0% +the initial nanot tube growth and that's + + + align:start position:0% +the initial nanot tube growth and that's +where it + + align:start position:0% +where it + + + align:start position:0% +where it +ended so I noticed two things yeah Sun + + align:start position:0% +ended so I noticed two things yeah Sun + + + align:start position:0% +ended so I noticed two things yeah Sun +Rings are oh yeah yeah actually that's + + align:start position:0% +Rings are oh yeah yeah actually that's + + + align:start position:0% +Rings are oh yeah yeah actually that's +that's a really good point so so that + + align:start position:0% +that's a really good point so so that + + + align:start position:0% +that's a really good point so so that +was a you know very interesting part of + + align:start position:0% +was a you know very interesting part of + + + align:start position:0% +was a you know very interesting part of +the analysis is what kind what kind of + + align:start position:0% +the analysis is what kind what kind of + + + align:start position:0% +the analysis is what kind what kind of +carbon you get right when you catalyze + + align:start position:0% +carbon you get right when you catalyze + + + align:start position:0% +carbon you get right when you catalyze +Carbon on a Surface um what does it do + + align:start position:0% +Carbon on a Surface um what does it do + + + align:start position:0% +Carbon on a Surface um what does it do +right does it form nice graphing and + + align:start position:0% +right does it form nice graphing and + + + align:start position:0% +right does it form nice graphing and +then curve it or does it form the + + align:start position:0% +then curve it or does it form the + + + align:start position:0% +then curve it or does it form the +defects so that you can curve it where + + align:start position:0% +defects so that you can curve it where + + + align:start position:0% +defects so that you can curve it where +the penalties in energy coming from but + + align:start position:0% +the penalties in energy coming from but + + + align:start position:0% +the penalties in energy coming from but +actually I was going to say I was going + + align:start position:0% +actually I was going to say I was going + + + align:start position:0% +actually I was going to say I was going +to kind of say some negative things two + + align:start position:0% +to kind of say some negative things two + + + align:start position:0% +to kind of say some negative things two +negative things they're not negatives + + align:start position:0% +negative things they're not negatives + + + align:start position:0% +negative things they're not negatives +but they're + + align:start position:0% +but they're + + + align:start position:0% +but they're +limitations tell me something obvious + + align:start position:0% +limitations tell me something obvious + + + align:start position:0% +limitations tell me something obvious +about this compared to say the protein + + align:start position:0% +about this compared to say the protein + + + align:start position:0% +about this compared to say the protein +simulations you did in the first + + align:start position:0% +simulations you did in the first + + + align:start position:0% +simulations you did in the first +part yeah this is really tiny and how + + align:start position:0% +part yeah this is really tiny and how + + + align:start position:0% +part yeah this is really tiny and how +long do you think this + + align:start position:0% + + + + align:start position:0% + +went what is + + align:start position:0% +went what is + + + align:start position:0% +went what is +that uh I'm not going to tell you + + align:start position:0% +that uh I'm not going to tell you + + + align:start position:0% +that uh I'm not going to tell you +because that would make me feel old um a + + align:start position:0% +because that would make me feel old um a + + + align:start position:0% +because that would make me feel old um a +while + + align:start position:0% +while + + + align:start position:0% +while +ago uh well so you know but anyway how + + align:start position:0% +ago uh well so you know but anyway how + + + align:start position:0% +ago uh well so you know but anyway how +long can you run a molecular Dynamic + + align:start position:0% +long can you run a molecular Dynamic + + + align:start position:0% +long can you run a molecular Dynamic +simulation having to do Quant mechanics + + align:start position:0% +simulation having to do Quant mechanics + + + align:start position:0% +simulation having to do Quant mechanics +at each + + align:start position:0% +at each + + + align:start position:0% +at each +step yeah + + align:start position:0% +step yeah + + + align:start position:0% +step yeah +like well how long could you do proteins + + align:start position:0% +like well how long could you do proteins + + + align:start position:0% +like well how long could you do proteins +with classical ND huge systems could you + + align:start position:0% +with classical ND huge systems could you + + + align:start position:0% +with classical ND huge systems could you +do them for seconds no but how + + align:start position:0% +do them for seconds no but how + + + align:start position:0% +do them for seconds no but how +long yeah actually even longer with + + align:start position:0% +long yeah actually even longer with + + + align:start position:0% +long yeah actually even longer with +classical MD you can get up to microsc + + align:start position:0% +classical MD you can get up to microsc + + + align:start position:0% +classical MD you can get up to microsc +now certainly nanoseconds is is just you + + align:start position:0% +now certainly nanoseconds is is just you + + + align:start position:0% +now certainly nanoseconds is is just you +know 10 100 NCS no problem here we're at + + align:start position:0% +know 10 100 NCS no problem here we're at + + + align:start position:0% +know 10 100 NCS no problem here we're at +we're at 10 picoseconds right even two + + align:start position:0% +we're at 10 picoseconds right even two + + + align:start position:0% +we're at 10 picoseconds right even two +Picos nowadays you can push + + align:start position:0% +Picos nowadays you can push + + + align:start position:0% +Picos nowadays you can push +50 100 pics but you wouldn't go further + + align:start position:0% +50 100 pics but you wouldn't go further + + + align:start position:0% +50 100 pics but you wouldn't go further +than that it's really hard right so the + + align:start position:0% +than that it's really hard right so the + + + align:start position:0% +than that it's really hard right so the +time and size are real really limited um + + align:start position:0% +time and size are real really limited um + + + align:start position:0% +time and size are real really limited um +and that's why we you know with with + + align:start position:0% +and that's why we you know with with + + + align:start position:0% +and that's why we you know with with +Quantum MD you study small systems for + + align:start position:0% +Quantum MD you study small systems for + + + align:start position:0% +Quantum MD you study small systems for +short time scales this was nanocluster + + align:start position:0% +short time scales this was nanocluster + + + align:start position:0% +short time scales this was nanocluster +growth um the other thing I I want to + + align:start position:0% +growth um the other thing I I want to + + + align:start position:0% +growth um the other thing I I want to +you know I I think Quantum these are + + align:start position:0% +you know I I think Quantum these are + + + align:start position:0% +you know I I think Quantum these are +just kind of other things you can do + + align:start position:0% +just kind of other things you can do + + + align:start position:0% +just kind of other things you can do +this is supposed to be you know just + + align:start position:0% +this is supposed to be you know just + + + align:start position:0% +this is supposed to be you know just +making sure you see that + + align:start position:0% +making sure you see that + + + align:start position:0% +making sure you see that +it's not just the band structure in DOS + + align:start position:0% +it's not just the band structure in DOS + + + align:start position:0% +it's not just the band structure in DOS +there are other things you can do a lot + + align:start position:0% +there are other things you can do a lot + + + align:start position:0% +there are other things you can do a lot +of things with Quantum simulations um + + align:start position:0% +of things with Quantum simulations um + + + align:start position:0% +of things with Quantum simulations um +water is is is a really cool problem and + + align:start position:0% +water is is is a really cool problem and + + + align:start position:0% +water is is is a really cool problem and +um I I love cendes I love reading about + + align:start position:0% +um I I love cendes I love reading about + + + align:start position:0% +um I I love cendes I love reading about +caves has anybody read about Cavendish + + align:start position:0% +caves has anybody read about Cavendish + + + align:start position:0% +caves has anybody read about Cavendish +he's such a fascinating guy um he's a + + align:start position:0% +he's such a fascinating guy um he's a + + + align:start position:0% +he's such a fascinating guy um he's a +university Dropout he compared the + + align:start position:0% +university Dropout he compared the + + + align:start position:0% +university Dropout he compared the +connectivities of electrolytes and + + align:start position:0% +connectivities of electrolytes and + + + align:start position:0% +connectivities of electrolytes and +express the version of oma way ahead of + + align:start position:0% +express the version of oma way ahead of + + + align:start position:0% +express the version of oma way ahead of +time um and uh he he measured uh the + + align:start position:0% +time um and uh he he measured uh the + + + align:start position:0% +time um and uh he he measured uh the +gravitational constant and um and he + + align:start position:0% +gravitational constant and um and he + + + align:start position:0% +gravitational constant and um and he +came up with really water which at that + + align:start position:0% +came up with really water which at that + + + align:start position:0% +came up with really water which at that +point was flist flist flist in and + + align:start position:0% +point was flist flist flist in and + + + align:start position:0% +point was flist flist flist in and +deistic air which I love those names um + + align:start position:0% +deistic air which I love those names um + + + align:start position:0% +deistic air which I love those names um +which is hydrogen oxygen but anyway um + + align:start position:0% +which is hydrogen oxygen but anyway um + + + align:start position:0% +which is hydrogen oxygen but anyway um +you know water has these really + + align:start position:0% +you know water has these really + + + align:start position:0% +you know water has these really +interesting properties this is a + + align:start position:0% +interesting properties this is a + + + align:start position:0% +interesting properties this is a +wonderful website to read about water + + align:start position:0% +wonderful website to read about water + + + align:start position:0% +wonderful website to read about water +I'll give you the answer it actually + + align:start position:0% +I'll give you the answer it actually + + + align:start position:0% +I'll give you the answer it actually +looks like this + + align:start position:0% +looks like this + + + align:start position:0% +looks like this +right water sees water like this not + + align:start position:0% +right water sees water like this not + + + align:start position:0% +right water sees water like this not +like this right so um it really sees it + + align:start position:0% +like this right so um it really sees it + + + align:start position:0% +like this right so um it really sees it +you know much more spherical than we + + align:start position:0% +you know much more spherical than we + + + align:start position:0% +you know much more spherical than we +usually draw it um and yet it does have + + align:start position:0% +usually draw it um and yet it does have + + + align:start position:0% +usually draw it um and yet it does have +you know these very definite bondings + + align:start position:0% +you know these very definite bondings + + + align:start position:0% +you know these very definite bondings +that it likes to do and the point I want + + align:start position:0% +that it likes to do and the point I want + + + align:start position:0% +that it likes to do and the point I want +to make is when you go into an MD code + + align:start position:0% +to make is when you go into an MD code + + + align:start position:0% +to make is when you go into an MD code +and you put water in there did you use + + align:start position:0% +and you put water in there did you use + + + align:start position:0% +and you put water in there did you use +water in your protein simulations yeah + + align:start position:0% +water in your protein simulations yeah + + + align:start position:0% +water in your protein simulations yeah +what which water did you + + align:start position:0% +what which water did you + + + align:start position:0% +what which water did you +pick I mean you must have picked a + + align:start position:0% +pick I mean you must have picked a + + + align:start position:0% +pick I mean you must have picked a +potential or the code picked a + + align:start position:0% +potential or the code picked a + + + align:start position:0% +potential or the code picked a +potential right tip 3p tip 4p well + + align:start position:0% +potential right tip 3p tip 4p well + + + align:start position:0% +potential right tip 3p tip 4p well +there's hundreds of them there's hundred + + align:start position:0% +there's hundreds of them there's hundred + + + align:start position:0% +there's hundreds of them there's hundred +these are just a few water potentials + + align:start position:0% +these are just a few water potentials + + + align:start position:0% +these are just a few water potentials +why are there so many well because some + + align:start position:0% +why are there so many well because some + + + align:start position:0% +why are there so many well because some +of them reproduce some things better + + align:start position:0% +of them reproduce some things better + + + align:start position:0% +of them reproduce some things better +than others right and that gets to be a + + align:start position:0% +than others right and that gets to be a + + + align:start position:0% +than others right and that gets to be a +a really serious problem if you want to + + align:start position:0% +a really serious problem if you want to + + + align:start position:0% +a really serious problem if you want to +study some of the fundamental problems + + align:start position:0% +study some of the fundamental problems + + + align:start position:0% +study some of the fundamental problems +of water um and there's so many + + align:start position:0% +of water um and there's so many + + + align:start position:0% +of water um and there's so many +Mysteries that we still don't know um in + + align:start position:0% +Mysteries that we still don't know um in + + + align:start position:0% +Mysteries that we still don't know um in +terms of just what happens when water + + align:start position:0% +terms of just what happens when water + + + align:start position:0% +terms of just what happens when water +evaporates freezes um and so you know + + align:start position:0% +evaporates freezes um and so you know + + + align:start position:0% +evaporates freezes um and so you know +which one is best well this a perfect + + align:start position:0% +which one is best well this a perfect + + + align:start position:0% +which one is best well this a perfect +problem for quantum mechanics okay and + + align:start position:0% +problem for quantum mechanics okay and + + + align:start position:0% +problem for quantum mechanics okay and +and I won't uh go through the details + + align:start position:0% +and I won't uh go through the details + + + align:start position:0% +and I won't uh go through the details +but you know um you can you can do water + + align:start position:0% +but you know um you can you can do water + + + align:start position:0% +but you know um you can you can do water +with Quantum um and this is a good way + + align:start position:0% +with Quantum um and this is a good way + + + align:start position:0% +with Quantum um and this is a good way +to validate which potential you use in + + align:start position:0% +to validate which potential you use in + + + align:start position:0% +to validate which potential you use in +your classical simulations you can also + + align:start position:0% +your classical simulations you can also + + + align:start position:0% +your classical simulations you can also +calculate phonons you can just displace + + align:start position:0% +calculate phonons you can just displace + + + align:start position:0% +calculate phonons you can just displace +atoms and calculate energies uh energy + + align:start position:0% +atoms and calculate energies uh energy + + + align:start position:0% +atoms and calculate energies uh energy +differences and get frequencies right so + + align:start position:0% +differences and get frequencies right so + + + align:start position:0% +differences and get frequencies right so +you can calculate phonons and when you + + align:start position:0% +you can calculate phonons and when you + + + align:start position:0% +you can calculate phonons and when you +calculate phonons in a + + align:start position:0% +calculate phonons in a + + + align:start position:0% +calculate phonons in a +crystal that's different than in a + + align:start position:0% +crystal that's different than in a + + + align:start position:0% +crystal that's different than in a +molecule okay um when you calculate + + align:start position:0% +molecule okay um when you calculate + + + align:start position:0% +molecule okay um when you calculate +phonons in a crystal you're getting you + + align:start position:0% +phonons in a crystal you're getting you + + + align:start position:0% +phonons in a crystal you're getting you +know the waves the sound waves you're + + align:start position:0% +know the waves the sound waves you're + + + align:start position:0% +know the waves the sound waves you're +going to get the O the acoustic waves in + + align:start position:0% +going to get the O the acoustic waves in + + + align:start position:0% +going to get the O the acoustic waves in +the material right um so you know in in + + align:start position:0% +the material right um so you know in in + + + align:start position:0% +the material right um so you know in in +let's go just using water in a water + + align:start position:0% +let's go just using water in a water + + + align:start position:0% +let's go just using water in a water +molecule how many phonon modes do I + + align:start position:0% + + + + align:start position:0% + +have in a water + + align:start position:0% +have in a water + + + align:start position:0% +have in a water +molecule who can tell + + align:start position:0% +molecule who can tell + + + align:start position:0% +molecule who can tell +me take a guess it's a good guess let's + + align:start position:0% +me take a guess it's a good guess let's + + + align:start position:0% +me take a guess it's a good guess let's +get rid of translational and + + align:start position:0% +get rid of translational and + + + align:start position:0% +get rid of translational and +rotational how many ways can a a water + + align:start position:0% +rotational how many ways can a a water + + + align:start position:0% +rotational how many ways can a a water +molecule + + align:start position:0% + + + + align:start position:0% + +stretch yeah there's actually three + + align:start position:0% +stretch yeah there's actually three + + + align:start position:0% +stretch yeah there's actually three +right because you can have the O's can + + align:start position:0% +right because you can have the O's can + + + align:start position:0% +right because you can have the O's can +stretch and the bond can stretch but + + align:start position:0% +stretch and the bond can stretch but + + + align:start position:0% +stretch and the bond can stretch but +then there's sort of two different ways + + align:start position:0% +then there's sort of two different ways + + + align:start position:0% +then there's sort of two different ways +that it can go + + align:start position:0% +that it can go + + + align:start position:0% +that it can go +right and so + + align:start position:0% +right and so + + + align:start position:0% +right and so +um + + align:start position:0% +um + + + align:start position:0% +um +uh those are your phono modes for the + + align:start position:0% +uh those are your phono modes for the + + + align:start position:0% +uh those are your phono modes for the +molecule it's just stretch frequencies + + align:start position:0% +molecule it's just stretch frequencies + + + align:start position:0% +molecule it's just stretch frequencies +right and they can be measured in a + + align:start position:0% +right and they can be measured in a + + + align:start position:0% +right and they can be measured in a +solid you calculate your phono modes by + + align:start position:0% +solid you calculate your phono modes by + + + align:start position:0% +solid you calculate your phono modes by +moving atoms around in the latice right + + align:start position:0% +moving atoms around in the latice right + + + align:start position:0% +moving atoms around in the latice right +and that actually gives you um the + + align:start position:0% +and that actually gives you um the + + + align:start position:0% +and that actually gives you um the +behavior of of the wave of the sound + + align:start position:0% +behavior of of the wave of the sound + + + align:start position:0% +behavior of of the wave of the sound +waves in the material which tells you + + align:start position:0% +waves in the material which tells you + + + align:start position:0% +waves in the material which tells you +something about how sound travels in the + + align:start position:0% +something about how sound travels in the + + + align:start position:0% +something about how sound travels in the +solid you can calculate the sound + + align:start position:0% +solid you can calculate the sound + + + align:start position:0% +solid you can calculate the sound +velocity you can calculate thermal uh + + align:start position:0% +velocity you can calculate thermal uh + + + align:start position:0% +velocity you can calculate thermal uh +transport you can calculate the heat + + align:start position:0% +transport you can calculate the heat + + + align:start position:0% +transport you can calculate the heat +capacity of the material all of this uh + + align:start position:0% +capacity of the material all of this uh + + + align:start position:0% +capacity of the material all of this uh +are things that we do with quantum + + align:start position:0% +are things that we do with quantum + + + align:start position:0% +are things that we do with quantum +mechanics that we're not going to do you + + align:start position:0% +mechanics that we're not going to do you + + + align:start position:0% +mechanics that we're not going to do you +know in any of our problems or anymore + + align:start position:0% +know in any of our problems or anymore + + + align:start position:0% +know in any of our problems or anymore +but I just wanted you to be aware of + + align:start position:0% +but I just wanted you to be aware of + + + align:start position:0% +but I just wanted you to be aware of +some of the things that people do in in + + align:start position:0% +some of the things that people do in in + + + align:start position:0% +some of the things that people do in in +research and and that are you know uh uh + + align:start position:0% +research and and that are you know uh uh + + + align:start position:0% +research and and that are you know uh uh +really a big part of quantum mechanical + + align:start position:0% +really a big part of quantum mechanical + + + align:start position:0% +really a big part of quantum mechanical +simulations + + align:start position:0% +simulations + + + align:start position:0% +simulations +okay now um I so so those are some of + + align:start position:0% +okay now um I so so those are some of + + + align:start position:0% +okay now um I so so those are some of +the properties that was sort of the + + align:start position:0% +the properties that was sort of the + + + align:start position:0% +the properties that was sort of the +point here you can do a calculate a wide + + align:start position:0% +point here you can do a calculate a wide + + + align:start position:0% +point here you can do a calculate a wide +range of properties this has sort of + + align:start position:0% +range of properties this has sort of + + + align:start position:0% +range of properties this has sort of +been our Focus these + + align:start position:0% +been our Focus these + + + align:start position:0% +been our Focus these +two okay and we're going to stay with + + align:start position:0% +two okay and we're going to stay with + + + align:start position:0% +two okay and we're going to stay with +that Focus but there's a a very large + + align:start position:0% +that Focus but there's a a very large + + + align:start position:0% +that Focus but there's a a very large +range of things you can do um now I want + + align:start position:0% +range of things you can do um now I want + + + align:start position:0% +range of things you can do um now I want +to just end I got five minutes okay and + + align:start position:0% +to just end I got five minutes okay and + + + align:start position:0% +to just end I got five minutes okay and +I'm I'm going to start solar we'll start + + align:start position:0% +I'm I'm going to start solar we'll start + + + align:start position:0% +I'm I'm going to start solar we'll start +solar with this on uh Tuesday but for + + align:start position:0% +solar with this on uh Tuesday but for + + + align:start position:0% +solar with this on uh Tuesday but for +five minutes I want to do a simulation + + align:start position:0% +five minutes I want to do a simulation + + + align:start position:0% +five minutes I want to do a simulation +um so um so we'll start solar on two + + align:start position:0% +um so um so we'll start solar on two + + + align:start position:0% +um so um so we'll start solar on two +Tuesday but here we + + align:start position:0% +Tuesday but here we + + + align:start position:0% +Tuesday but here we +are you know which tool it is it's our + + align:start position:0% + + + + align:start position:0% + +favorite and we'll do another problem + + align:start position:0% +favorite and we'll do another problem + + + align:start position:0% +favorite and we'll do another problem +you know or two in class and I can I can + + align:start position:0% +you know or two in class and I can I can + + + align:start position:0% +you know or two in class and I can I can +do a little review I I sort of did that + + align:start position:0% +do a little review I I sort of did that + + + align:start position:0% +do a little review I I sort of did that +on Tuesday of this week does anybody + + align:start position:0% +on Tuesday of this week does anybody + + + align:start position:0% +on Tuesday of this week does anybody +want to do more review next week or what + + align:start position:0% +want to do more review next week or what + + + align:start position:0% +want to do more review next week or what +do you guys think a little bit yeah okay + + align:start position:0% +do you guys think a little bit yeah okay + + + align:start position:0% +do you guys think a little bit yeah okay +I can do some sort of like what I'll do + + align:start position:0% +I can do some sort of like what I'll do + + + align:start position:0% +I can do some sort of like what I'll do +next Tuesday is we'll do another + + align:start position:0% +next Tuesday is we'll do another + + + align:start position:0% +next Tuesday is we'll do another +homework problem from last + + align:start position:0% +homework problem from last + + + align:start position:0% +homework problem from last +um uh year another quiz problem from + + align:start position:0% +um uh year another quiz problem from + + + align:start position:0% +um uh year another quiz problem from +last year like we did today I'll ask if + + align:start position:0% +last year like we did today I'll ask if + + + align:start position:0% +last year like we did today I'll ask if +you have any questions about this + + align:start position:0% +you have any questions about this + + + align:start position:0% +you have any questions about this +practice uh quiz but I'll I'll also post + + align:start position:0% +practice uh quiz but I'll I'll also post + + + align:start position:0% +practice uh quiz but I'll I'll also post +the solutions and I'll I'll go over sort + + align:start position:0% +the solutions and I'll I'll go over sort + + + align:start position:0% +the solutions and I'll I'll go over sort +of some key things to keep in mind for + + align:start position:0% +of some key things to keep in mind for + + + align:start position:0% +of some key things to keep in mind for +the quiz okay so we'll spend the first + + align:start position:0% +the quiz okay so we'll spend the first + + + align:start position:0% +the quiz okay so we'll spend the first +half of class on that then but let me + + align:start position:0% +half of class on that then but let me + + + align:start position:0% +half of class on that then but let me +just spend the last few minutes here + + align:start position:0% +just spend the last few minutes here + + + align:start position:0% +just spend the last few minutes here +let's do a + + align:start position:0% + + + + align:start position:0% + +simulation okay + + align:start position:0% +simulation okay + + + align:start position:0% +simulation okay +it's open Notes open Notes + + align:start position:0% +it's open Notes open Notes + + + align:start position:0% +it's open Notes open Notes +yeah uh I think + + align:start position:0% +yeah uh I think + + + align:start position:0% +yeah uh I think +no cuz that's sort of like open every + + align:start position:0% +no cuz that's sort of like open every + + + align:start position:0% +no cuz that's sort of like open every +that's like everything right is it what + + align:start position:0% +that's like everything right is it what + + + align:start position:0% +that's like everything right is it what +did you guys do in the first part you + + align:start position:0% +did you guys do in the first part you + + + align:start position:0% +did you guys do in the first part you +had the + + align:start position:0% + + + + align:start position:0% + +computers okay + + align:start position:0% + + + + align:start position:0% + +I mean um you know so okay let's put it + + align:start position:0% +I mean um you know so okay let's put it + + + align:start position:0% +I mean um you know so okay let's put it +this way if we do open computers then + + align:start position:0% +this way if we do open computers then + + + align:start position:0% +this way if we do open computers then +I'll make the problems + + align:start position:0% +I'll make the problems + + + align:start position:0% +I'll make the problems +harder okay all right because I think I + + align:start position:0% +harder okay all right because I think I + + + align:start position:0% +harder okay all right because I think I +mean I think because you know if you + + align:start position:0% +mean I think because you know if you + + + align:start position:0% +mean I think because you know if you +have the you know Wikipedia is pretty + + align:start position:0% +have the you know Wikipedia is pretty + + + align:start position:0% +have the you know Wikipedia is pretty +powerful right and and Google and so you + + align:start position:0% +powerful right and and Google and so you + + + align:start position:0% +powerful right and and Google and so you +know if you have that um you can find a + + align:start position:0% +know if you have that um you can find a + + + align:start position:0% +know if you have that um you can find a +lot of uh close answers um with the + + align:start position:0% +lot of uh close answers um with the + + + align:start position:0% +lot of uh close answers um with the +quick search so I I'd have to kind of be + + align:start position:0% +quick search so I I'd have to kind of be + + + align:start position:0% +quick search so I I'd have to kind of be +a little more creative but I you know + + align:start position:0% +a little more creative but I you know + + + align:start position:0% +a little more creative but I you know +you won't need your computers and it's + + align:start position:0% +you won't need your computers and it's + + + align:start position:0% +you won't need your computers and it's +full open Notes right so + + align:start position:0% +full open Notes right so + + + align:start position:0% +full open Notes right so +um okay now + + align:start position:0% +um okay now + + + align:start position:0% +um okay now +um here's what I wanted to do so + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% + + + + align:start position:0% + +okay let's go to our favorite thing here + + align:start position:0% +okay let's go to our favorite thing here + + + align:start position:0% +okay let's go to our favorite thing here +Siesta there it + + align:start position:0% +Siesta there it + + + align:start position:0% +Siesta there it +is + + align:start position:0% +is + + + align:start position:0% +is +um so I wanted to show you this uh first + + align:start position:0% +um so I wanted to show you this uh first + + + align:start position:0% +um so I wanted to show you this uh first +of all this feature here + + align:start position:0% + + + + align:start position:0% + +which is that spin polarized do you see + + align:start position:0% +which is that spin polarized do you see + + + align:start position:0% +which is that spin polarized do you see +yes no okay now when it's yes and I + + align:start position:0% +yes no okay now when it's yes and I + + + align:start position:0% +yes no okay now when it's yes and I +calculate + + align:start position:0% +calculate + + + align:start position:0% +calculate +silicon okay here's the um here's the + + align:start position:0% +silicon okay here's the um here's the + + + align:start position:0% +silicon okay here's the um here's the +calculation of the density of states of + + align:start position:0% +calculation of the density of states of + + + align:start position:0% +calculation of the density of states of +silicon is what I want to show you + + align:start position:0% + + + + align:start position:0% + +um what you are going to + + align:start position:0% +um what you are going to + + + align:start position:0% +um what you are going to +find oh I didn't plot the structure okay + + align:start position:0% +find oh I didn't plot the structure okay + + + align:start position:0% +find oh I didn't plot the structure okay +is that okay so this is kind of just + + align:start position:0% +is that okay so this is kind of just + + + align:start position:0% +is that okay so this is kind of just +rounding out our our Siesta uh you know + + align:start position:0% +rounding out our our Siesta uh you know + + + align:start position:0% +rounding out our our Siesta uh you know +understanding of what the tool does + + align:start position:0% +understanding of what the tool does + + + align:start position:0% +understanding of what the tool does +because there were just these few things + + align:start position:0% +because there were just these few things + + + align:start position:0% +because there were just these few things +that we hadn't talked about um this is + + align:start position:0% +that we hadn't talked about um this is + + + align:start position:0% +that we hadn't talked about um this is +the density of states and you now really + + align:start position:0% +the density of states and you now really + + + align:start position:0% +the density of states and you now really +feel your Oneness with this you know + + align:start position:0% +feel your Oneness with this you know + + + align:start position:0% +feel your Oneness with this you know +what these are you look at this and you + + align:start position:0% +what these are you look at this and you + + + align:start position:0% +what these are you look at this and you +you and you get emotional which is okay + + align:start position:0% +you and you get emotional which is okay + + + align:start position:0% +you and you get emotional which is okay +okay but look at this I also have + + align:start position:0% +okay but look at this I also have + + + align:start position:0% +okay but look at this I also have +here because I did um uh let's see if it + + align:start position:0% +here because I did um uh let's see if it + + + align:start position:0% +here because I did um uh let's see if it +does this + + align:start position:0% +does this + + + align:start position:0% +does this +right uh + + align:start position:0% +right uh + + + align:start position:0% +right uh +total and there look at that okay you + + align:start position:0% +total and there look at that okay you + + + align:start position:0% +total and there look at that okay you +see it's automatically doing what's + + align:start position:0% +see it's automatically doing what's + + + align:start position:0% +see it's automatically doing what's +called a projected density of States and + + align:start position:0% +called a projected density of States and + + + align:start position:0% +called a projected density of States and +what a projected density of states is is + + align:start position:0% +what a projected density of states is is + + + align:start position:0% +what a projected density of states is is +it's the density of States but only for + + align:start position:0% +it's the density of States but only for + + + align:start position:0% +it's the density of States but only for +certain part of the + + align:start position:0% +certain part of the + + + align:start position:0% +certain part of the +system which turns out to be really + + align:start position:0% +system which turns out to be really + + + align:start position:0% +system which turns out to be really +interesting like sometimes you just want + + align:start position:0% +interesting like sometimes you just want + + + align:start position:0% +interesting like sometimes you just want +to know the density of states for one + + align:start position:0% +to know the density of states for one + + + align:start position:0% +to know the density of states for one +type of atom where is that atom + + align:start position:0% +type of atom where is that atom + + + align:start position:0% +type of atom where is that atom +contributing to the states okay or in + + align:start position:0% +contributing to the states okay or in + + + align:start position:0% +contributing to the states okay or in +this case because I did spin polarized + + align:start position:0% +this case because I did spin polarized + + + align:start position:0% +this case because I did spin polarized +it's giving me the density of states for + + align:start position:0% +it's giving me the density of states for + + + align:start position:0% +it's giving me the density of states for +spin down and spin up separately and + + align:start position:0% +spin down and spin up separately and + + + align:start position:0% +spin down and spin up separately and +look at this they + + align:start position:0% +look at this they + + + align:start position:0% +look at this they +are um well spin down spin down it you + + align:start position:0% +are um well spin down spin down it you + + + align:start position:0% +are um well spin down spin down it you +can't see it um because there's some + + align:start position:0% +can't see it um because there's some + + + align:start position:0% +can't see it um because there's some +spin up in there they're exactly on top + + align:start position:0% +spin up in there they're exactly on top + + + align:start position:0% +spin up in there they're exactly on top +of each other what does that + + align:start position:0% + + + + align:start position:0% + +mean there's all the spin up electrons + + align:start position:0% +mean there's all the spin up electrons + + + align:start position:0% +mean there's all the spin up electrons +when they're paired with spin down they + + align:start position:0% +when they're paired with spin down they + + + align:start position:0% +when they're paired with spin down they +all um have the same energy okay they + + align:start position:0% +all um have the same energy okay they + + + align:start position:0% +all um have the same energy okay they +have the exact same position on this and + + align:start position:0% +have the exact same position on this and + + + align:start position:0% +have the exact same position on this and +they lead to this total Doss here they + + align:start position:0% +they lead to this total Doss here they + + + align:start position:0% +they lead to this total Doss here they +just add up but now if and so if I did + + align:start position:0% +just add up but now if and so if I did + + + align:start position:0% +just add up but now if and so if I did +silicon with spin polarized off then um + + align:start position:0% +silicon with spin polarized off then um + + + align:start position:0% +silicon with spin polarized off then um +the answer would be exactly the same so + + align:start position:0% +the answer would be exactly the same so + + + align:start position:0% +the answer would be exactly the same so +there was really no need to do it with + + align:start position:0% +there was really no need to do it with + + + align:start position:0% +there was really no need to do it with +been polarized but it's the default and + + align:start position:0% +been polarized but it's the default and + + + align:start position:0% +been polarized but it's the default and +now if I do + + align:start position:0% +now if I do + + + align:start position:0% +now if I do +iron you see and I press + + align:start position:0% +iron you see and I press + + + align:start position:0% +iron you see and I press +simulate then um what you'll find is + + align:start position:0% +simulate then um what you'll find is + + + align:start position:0% +simulate then um what you'll find is +that + + align:start position:0% +that + + + align:start position:0% +that +um uh you should see a difference let's + + align:start position:0% +um uh you should see a difference let's + + + align:start position:0% +um uh you should see a difference let's +see if we + + align:start position:0% +see if we + + + align:start position:0% +see if we +do + + align:start position:0% +do + + + align:start position:0% +do +okay here is + + align:start position:0% +okay here is + + + align:start position:0% +okay here is +iron and now you have the total the + + align:start position:0% +iron and now you have the total the + + + align:start position:0% +iron and now you have the total the +total density of States oh what is this + + align:start position:0% +total density of States oh what is this + + + align:start position:0% +total density of States oh what is this +um I forget is this an + + align:start position:0% + + + + align:start position:0% + +insulator how do I + + align:start position:0% +insulator how do I + + + align:start position:0% +insulator how do I +know because I got some Doss + + align:start position:0% +know because I got some Doss + + + align:start position:0% +know because I got some Doss +here right in at the firmy energy + + align:start position:0% +here right in at the firmy energy + + + align:start position:0% +here right in at the firmy energy +and if I do the the oh we got to do it + + align:start position:0% +and if I do the the oh we got to do it + + + align:start position:0% +and if I do the the oh we got to do it +for + + align:start position:0% +for + + + align:start position:0% +for +um Iron okay and now look at this this + + align:start position:0% +um Iron okay and now look at this this + + + align:start position:0% +um Iron okay and now look at this this +is beautiful there is um my spin okay so + + align:start position:0% +is beautiful there is um my spin okay so + + + align:start position:0% +is beautiful there is um my spin okay so +there is this is the total the green + + align:start position:0% +there is this is the total the green + + + align:start position:0% +there is this is the total the green +okay that's the total and look at this + + align:start position:0% +okay that's the total and look at this + + + align:start position:0% +okay that's the total and look at this +the red is the spin down and the blue is + + align:start position:0% +the red is the spin down and the blue is + + + align:start position:0% +the red is the spin down and the blue is +the spin up and look at those + + align:start position:0% +the spin up and look at those + + + align:start position:0% +the spin up and look at those +differences what does it mean + + align:start position:0% +differences what does it mean + + + align:start position:0% +differences what does it mean +I mean you got to integrate it to know + + align:start position:0% +I mean you got to integrate it to know + + + align:start position:0% +I mean you got to integrate it to know +but there's a difference there's a big + + align:start position:0% +but there's a difference there's a big + + + align:start position:0% +but there's a difference there's a big +difference in the spin up and spin down + + align:start position:0% +difference in the spin up and spin down + + + align:start position:0% +difference in the spin up and spin down +electrons and where they sit in energy + + align:start position:0% +electrons and where they sit in energy + + + align:start position:0% +electrons and where they sit in energy +space in the magnetic material there can + + align:start position:0% +space in the magnetic material there can + + + align:start position:0% +space in the magnetic material there can +be that's what makes it a magnet okay + + align:start position:0% +be that's what makes it a magnet okay + + + align:start position:0% +be that's what makes it a magnet okay +and so if you integrate that difference + + align:start position:0% +and so if you integrate that difference + + + align:start position:0% +and so if you integrate that difference +up to here well then you're going to get + + align:start position:0% +up to here well then you're going to get + + + align:start position:0% +up to here well then you're going to get +its magnetization right um if I + + align:start position:0% +its magnetization right um if I + + + align:start position:0% +its magnetization right um if I +simulated iron with spin polarized turn + + align:start position:0% +simulated iron with spin polarized turn + + + align:start position:0% +simulated iron with spin polarized turn +off it would force it would force those + + align:start position:0% +off it would force it would force those + + + align:start position:0% +off it would force it would force those +to be exactly the same and they would + + align:start position:0% +to be exactly the same and they would + + + align:start position:0% +to be exactly the same and they would +lie exact on top of each other just like + + align:start position:0% +lie exact on top of each other just like + + + align:start position:0% +lie exact on top of each other just like +they just did in Silicon okay but that + + align:start position:0% +they just did in Silicon okay but that + + + align:start position:0% +they just did in Silicon okay but that +would be not iron so you got to be aware + + align:start position:0% +would be not iron so you got to be aware + + + align:start position:0% +would be not iron so you got to be aware +of what this spin spin thing is and when + + align:start position:0% +of what this spin spin thing is and when + + + align:start position:0% +of what this spin spin thing is and when +you need it when it's important keeping + + align:start position:0% +you need it when it's important keeping + + + align:start position:0% +you need it when it's important keeping +it on is safe okay but I wanted you to + + align:start position:0% +it on is safe okay but I wanted you to + + + align:start position:0% +it on is safe okay but I wanted you to +know what it means so okay very good + + align:start position:0% +know what it means so okay very good + + + align:start position:0% +know what it means so okay very good +have a good weekend \ No newline at end of file diff --git a/cCmWW7Hu43A.txt b/cCmWW7Hu43A.txt new file mode 100644 index 0000000000000000000000000000000000000000..7a15257493b3fde4eaa7473976960603af65cc95 --- /dev/null +++ b/cCmWW7Hu43A.txt @@ -0,0 +1,635 @@ +align:start position:0% + +one particular series that shows up in + + align:start position:0% +one particular series that shows up in + + + align:start position:0% +one particular series that shows up in +many applications examples or problems + + align:start position:0% +many applications examples or problems + + + align:start position:0% +many applications examples or problems +is the geometric series the geometric + + align:start position:0% +is the geometric series the geometric + + + align:start position:0% +is the geometric series the geometric +series were given a certain number alpha + + align:start position:0% +series were given a certain number alpha + + + align:start position:0% +series were given a certain number alpha +and we want to sum all the powers of + + align:start position:0% +and we want to sum all the powers of + + + align:start position:0% +and we want to sum all the powers of +alpha starting from the zeroth power + + align:start position:0% +alpha starting from the zeroth power + + + align:start position:0% +alpha starting from the zeroth power +which is equal to 1 the first power and + + align:start position:0% +which is equal to 1 the first power and + + + align:start position:0% +which is equal to 1 the first power and +so on and this gives us an infinite + + align:start position:0% +so on and this gives us an infinite + + + align:start position:0% +so on and this gives us an infinite +series it's the sum of alpha to the I + + align:start position:0% +series it's the sum of alpha to the I + + + align:start position:0% +series it's the sum of alpha to the I +where I ranges from zero to infinity now + + align:start position:0% +where I ranges from zero to infinity now + + + align:start position:0% +where I ranges from zero to infinity now +for this series to converge we need + + align:start position:0% +for this series to converge we need + + + align:start position:0% +for this series to converge we need +subsequent terms the different terms in + + align:start position:0% +subsequent terms the different terms in + + + align:start position:0% +subsequent terms the different terms in +the series to become smaller and smaller + + align:start position:0% +the series to become smaller and smaller + + + align:start position:0% +the series to become smaller and smaller +and for this reason we're going to make + + align:start position:0% +and for this reason we're going to make + + + align:start position:0% +and for this reason we're going to make +the assumption that the number alpha is + + align:start position:0% +the assumption that the number alpha is + + + align:start position:0% +the assumption that the number alpha is +less than 1 in magnitude which implies + + align:start position:0% +less than 1 in magnitude which implies + + + align:start position:0% +less than 1 in magnitude which implies +that consecutive terms go to 0 let us + + align:start position:0% +that consecutive terms go to 0 let us + + + align:start position:0% +that consecutive terms go to 0 let us +introduce some notation let us denote + + align:start position:0% +introduce some notation let us denote + + + align:start position:0% +introduce some notation let us denote +the infinite sum by s and we're going to + + align:start position:0% +the infinite sum by s and we're going to + + + align:start position:0% +the infinite sum by s and we're going to +use that notation shortly one way of + + align:start position:0% +use that notation shortly one way of + + + align:start position:0% +use that notation shortly one way of +evaluating this series is to start from + + align:start position:0% +evaluating this series is to start from + + + align:start position:0% +evaluating this series is to start from +an algebraic identity namely the + + align:start position:0% +an algebraic identity namely the + + + align:start position:0% +an algebraic identity namely the +following let us take 1 minus alpha and + + align:start position:0% +following let us take 1 minus alpha and + + + align:start position:0% +following let us take 1 minus alpha and +multiply it by the terms in the series + + align:start position:0% +multiply it by the terms in the series + + + align:start position:0% +multiply it by the terms in the series +but going only up to the term alpha to + + align:start position:0% +but going only up to the term alpha to + + + align:start position:0% +but going only up to the term alpha to +the N so it's a finite series we do this + + align:start position:0% +the N so it's a finite series we do this + + + align:start position:0% +the N so it's a finite series we do this +multiplication we get a bunch of terms + + align:start position:0% +multiplication we get a bunch of terms + + + align:start position:0% +multiplication we get a bunch of terms +we do the cancellations and what is left + + align:start position:0% +we do the cancellations and what is left + + + align:start position:0% +we do the cancellations and what is left +at the end is 1 minus alpha to the power + + align:start position:0% +at the end is 1 minus alpha to the power + + + align:start position:0% +at the end is 1 minus alpha to the power +n plus 1 what we do next is we take the + + align:start position:0% +n plus 1 what we do next is we take the + + + align:start position:0% +n plus 1 what we do next is we take the +limit as n goes to infinity on the left + + align:start position:0% +limit as n goes to infinity on the left + + + align:start position:0% +limit as n goes to infinity on the left +hand side we have the term 1 minus alpha + + align:start position:0% +hand side we have the term 1 minus alpha + + + align:start position:0% +hand side we have the term 1 minus alpha +and then the limit of this finite series + + align:start position:0% +and then the limit of this finite series + + + align:start position:0% +and then the limit of this finite series +is by definition the infinite series + + align:start position:0% +is by definition the infinite series + + + align:start position:0% +is by definition the infinite series +which we are denoting by s on the right + + align:start position:0% +which we are denoting by s on the right + + + align:start position:0% +which we are denoting by s on the right +hand side we have the term 1 how about + + align:start position:0% +hand side we have the term 1 how about + + + align:start position:0% +hand side we have the term 1 how about +this term since alpha is less than 1 in + + align:start position:0% +this term since alpha is less than 1 in + + + align:start position:0% +this term since alpha is less than 1 in +magnitude this converges to 0 as alpha + + align:start position:0% +magnitude this converges to 0 as alpha + + + align:start position:0% +magnitude this converges to 0 as alpha +goes to infinity so that term disappears + + align:start position:0% +goes to infinity so that term disappears + + + align:start position:0% +goes to infinity so that term disappears +we can now solve this relation and we + + align:start position:0% +we can now solve this relation and we + + + align:start position:0% +we can now solve this relation and we +obtain that s is equal to 1 over 1 minus + + align:start position:0% +obtain that s is equal to 1 over 1 minus + + + align:start position:0% +obtain that s is equal to 1 over 1 minus +alpha and this is the formula for the + + align:start position:0% +alpha and this is the formula for the + + + align:start position:0% +alpha and this is the formula for the +infinite geometric series there's + + align:start position:0% +infinite geometric series there's + + + align:start position:0% +infinite geometric series there's +another way of deriving the same result + + align:start position:0% +another way of deriving the same result + + + align:start position:0% +another way of deriving the same result +which is interesting so let us go + + align:start position:0% +which is interesting so let us go + + + align:start position:0% +which is interesting so let us go +through it as well + + align:start position:0% +through it as well + + + align:start position:0% +through it as well +the infinite geometric series has one + + align:start position:0% +the infinite geometric series has one + + + align:start position:0% +the infinite geometric series has one +first term and then the remaining terms + + align:start position:0% +first term and then the remaining terms + + + align:start position:0% +first term and then the remaining terms +which is a sum for I going from 1 to + + align:start position:0% +which is a sum for I going from 1 to + + + align:start position:0% +which is a sum for I going from 1 to +infinity of alpha to the I now we can + + align:start position:0% +infinity of alpha to the I now we can + + + align:start position:0% +infinity of alpha to the I now we can +take a factor of alpha out of this + + align:start position:0% +take a factor of alpha out of this + + + align:start position:0% +take a factor of alpha out of this +infinite sum and write it as 1 plus + + align:start position:0% +infinite sum and write it as 1 plus + + + align:start position:0% +infinite sum and write it as 1 plus +alpha the sum of alpha to the I but + + align:start position:0% +alpha the sum of alpha to the I but + + + align:start position:0% +alpha the sum of alpha to the I but +because we took out one factor of alpha + + align:start position:0% +because we took out one factor of alpha + + + align:start position:0% +because we took out one factor of alpha +here we're going to have smaller powers + + align:start position:0% +here we're going to have smaller powers + + + align:start position:0% +here we're going to have smaller powers +so now the sum starts from 0 and goes up + + align:start position:0% +so now the sum starts from 0 and goes up + + + align:start position:0% +so now the sum starts from 0 and goes up +to infinity now this is just 1 plus + + align:start position:0% +to infinity now this is just 1 plus + + + align:start position:0% +to infinity now this is just 1 plus +alpha times s because here we have the + + align:start position:0% +alpha times s because here we have the + + + align:start position:0% +alpha times s because here we have the +infinite geometric series therefore if + + align:start position:0% +infinite geometric series therefore if + + + align:start position:0% +infinite geometric series therefore if +we subtract alpha s from both sides of + + align:start position:0% +we subtract alpha s from both sides of + + + align:start position:0% +we subtract alpha s from both sides of +this equality we get s times 1 minus + + align:start position:0% +this equality we get s times 1 minus + + + align:start position:0% +this equality we get s times 1 minus +alpha equal to 1 and now by moving one + + align:start position:0% +alpha equal to 1 and now by moving one + + + align:start position:0% +alpha equal to 1 and now by moving one +minus alpha to the denominator we get + + align:start position:0% +minus alpha to the denominator we get + + + align:start position:0% +minus alpha to the denominator we get +again the same expression so this is an + + align:start position:0% +again the same expression so this is an + + + align:start position:0% +again the same expression so this is an +alternative way of deriving the same + + align:start position:0% +alternative way of deriving the same + + + align:start position:0% +alternative way of deriving the same +result however there's one word of + + align:start position:0% +result however there's one word of + + + align:start position:0% +result however there's one word of +caution in this step we subtracted alpha + + align:start position:0% +caution in this step we subtracted alpha + + + align:start position:0% +caution in this step we subtracted alpha +s from both sides of the equation and in + + align:start position:0% +s from both sides of the equation and in + + + align:start position:0% +s from both sides of the equation and in +order to do that this is only possible + + align:start position:0% +order to do that this is only possible + + + align:start position:0% +order to do that this is only possible +if we take for granted that s is a + + align:start position:0% +if we take for granted that s is a + + + align:start position:0% +if we take for granted that s is a +finite number so this is taken for + + align:start position:0% +finite number so this is taken for + + + align:start position:0% +finite number so this is taken for +granted in order to carry out this + + align:start position:0% +granted in order to carry out this + + + align:start position:0% +granted in order to carry out this +derivation this is to be contrasted with + + align:start position:0% +derivation this is to be contrasted with + + + align:start position:0% +derivation this is to be contrasted with +the first derivation in which we didn't + + align:start position:0% +the first derivation in which we didn't + + + align:start position:0% +the first derivation in which we didn't +have to make any such assumption so + + align:start position:0% +have to make any such assumption so + + + align:start position:0% +have to make any such assumption so +strictly speaking for this derivation + + align:start position:0% +strictly speaking for this derivation + + + align:start position:0% +strictly speaking for this derivation +here to be correct we need to have some + + align:start position:0% +here to be correct we need to have some + + + align:start position:0% +here to be correct we need to have some +independent way of verifying that s is + + align:start position:0% +independent way of verifying that s is + + + align:start position:0% +independent way of verifying that s is +less than infinity but other than that + + align:start position:0% +less than infinity but other than that + + + align:start position:0% +less than infinity but other than that +it's an interesting algebraic trick \ No newline at end of file diff --git a/cN1mjMQyPBw.txt b/cN1mjMQyPBw.txt new file mode 100644 index 0000000000000000000000000000000000000000..7a0038131994fec6c4300ba25f8763777b1f51b2 --- /dev/null +++ b/cN1mjMQyPBw.txt @@ -0,0 +1,53 @@ +The biggest journey is made of +individual steps + +the first one is a big one + +so is each step taking you further. + +Fifteen years ago OpenCourseWare took +its first step + +revolutionary idea from MIT faculty to +openly shared their teaching materials + +from the MIT classrooms with the world + +syllabi, notes, homework, assignments, +videos, and more + +every year OpenCourseWare keeps growing + +adding hundreds of new learning +resources to use at any time + +for free + +every year millions of people use +OpenCourseWare to enhance their + +knowledge improve their lives and help +their communities + +every year thousands of people tell us +how OpenCourseWare + +has changed their lives for the better + +the most important step is the one you +take today + +help us continue this free and open +journey + +today help us celebrate 15 years of open sharing + +become one of 2001 supporters for this +crowd funding campaign your donation + +will go farther because MathWorks will +match donations up to $100,000 + +we've come a long way and we're still moving step by step by step + +thank you \ No newline at end of file diff --git a/d5chZ4A54DI.txt b/d5chZ4A54DI.txt new file mode 100644 index 0000000000000000000000000000000000000000..4fc5cb1a0c448d4c34b70520d30113c3ab2eece8 --- /dev/null +++ b/d5chZ4A54DI.txt @@ -0,0 +1,1051 @@ +align:start position:0% + +one of the reasons that high road + + align:start position:0% +one of the reasons that high road + + + align:start position:0% +one of the reasons that high road +companies like Saturn and others often + + align:start position:0% +companies like Saturn and others often + + + align:start position:0% +companies like Saturn and others often +don't get carried on is that once the + + align:start position:0% +don't get carried on is that once the + + + align:start position:0% +don't get carried on is that once the +founders leave the next generation of + + align:start position:0% +founders leave the next generation of + + + align:start position:0% +founders leave the next generation of +leaders don't carry on the same + + align:start position:0% +leaders don't carry on the same + + + align:start position:0% +leaders don't carry on the same +practices and so the culture goes back + + align:start position:0% +practices and so the culture goes back + + + align:start position:0% +practices and so the culture goes back +to more traditional organizations but + + align:start position:0% +to more traditional organizations but + + + align:start position:0% +to more traditional organizations but +there are ways to address this issue by + + align:start position:0% +there are ways to address this issue by + + + align:start position:0% +there are ways to address this issue by +building commitments to multiple + + align:start position:0% +building commitments to multiple + + + align:start position:0% +building commitments to multiple +stakeholders right into the bylaws of + + align:start position:0% +stakeholders right into the bylaws of + + + align:start position:0% +stakeholders right into the bylaws of +the corporation let's look at some + + align:start position:0% +the corporation let's look at some + + + align:start position:0% +the corporation let's look at some +examples we'll consider three different + + align:start position:0% +examples we'll consider three different + + + align:start position:0% +examples we'll consider three different +models first let's talk about what we + + align:start position:0% +models first let's talk about what we + + + align:start position:0% +models first let's talk about what we +call Benefit + + align:start position:0% +call Benefit + + + align:start position:0% +call Benefit +corporations benefit corporations build + + align:start position:0% +corporations benefit corporations build + + + align:start position:0% +corporations benefit corporations build +right into their charter three different + + align:start position:0% +right into their charter three different + + + align:start position:0% +right into their charter three different +objectives first they say they are going + + align:start position:0% +objectives first they say they are going + + + align:start position:0% +objectives first they say they are going +to commit to producing results that are + + align:start position:0% +to commit to producing results that are + + + align:start position:0% +to commit to producing results that are +good for their shareholders for their + + align:start position:0% +good for their shareholders for their + + + align:start position:0% +good for their shareholders for their +employees and for the economy secondly + + align:start position:0% +employees and for the economy secondly + + + align:start position:0% +employees and for the economy secondly +they are going to consider financial and + + align:start position:0% +they are going to consider financial and + + + align:start position:0% +they are going to consider financial and +non-financial considerations when making + + align:start position:0% +non-financial considerations when making + + + align:start position:0% +non-financial considerations when making +key decisions that allow them to keep + + align:start position:0% +key decisions that allow them to keep + + + align:start position:0% +key decisions that allow them to keep +the the benefits flowing to all of these + + align:start position:0% +the the benefits flowing to all of these + + + align:start position:0% +the the benefits flowing to all of these +stakeholders third they agree to be + + align:start position:0% +stakeholders third they agree to be + + + align:start position:0% +stakeholders third they agree to be +transparent they provide annual reports + + align:start position:0% +transparent they provide annual reports + + + align:start position:0% +transparent they provide annual reports +on their performance and their progress + + align:start position:0% +on their performance and their progress + + + align:start position:0% +on their performance and their progress +in addressing the interests of these + + align:start position:0% +in addressing the interests of these + + + align:start position:0% +in addressing the interests of these +multiple organizations one of the best + + align:start position:0% +multiple organizations one of the best + + + align:start position:0% +multiple organizations one of the best +known companies uh that is a benefit + + align:start position:0% +known companies uh that is a benefit + + + align:start position:0% +known companies uh that is a benefit +Corporation is Patagonia Patagonia is + + align:start position:0% +Corporation is Patagonia Patagonia is + + + align:start position:0% +Corporation is Patagonia Patagonia is +this very famous clothing maker and its + + align:start position:0% +this very famous clothing maker and its + + + align:start position:0% +this very famous clothing maker and its +CEO and founder Ivon shinard says + + align:start position:0% +CEO and founder Ivon shinard says + + + align:start position:0% +CEO and founder Ivon shinard says +Patagonia is trying to build a company + + align:start position:0% +Patagonia is trying to build a company + + + align:start position:0% +Patagonia is trying to build a company +that could last a 100 years benefit + + align:start position:0% +that could last a 100 years benefit + + + align:start position:0% +that could last a 100 years benefit +Corporation legislation creates the + + align:start position:0% +Corporation legislation creates the + + + align:start position:0% +Corporation legislation creates the +legal framework to enable mission-driven + + align:start position:0% +legal framework to enable mission-driven + + + align:start position:0% +legal framework to enable mission-driven +companies like Patagonia to stay + + align:start position:0% +companies like Patagonia to stay + + + align:start position:0% +companies like Patagonia to stay +mission-driven through succession + + align:start position:0% +mission-driven through succession + + + align:start position:0% +mission-driven through succession +through raising Capital through changes + + align:start position:0% +through raising Capital through changes + + + align:start position:0% +through raising Capital through changes +and ownership in doing so it + + align:start position:0% +and ownership in doing so it + + + align:start position:0% +and ownership in doing so it +institutionalizes the value the cultures + + align:start position:0% +institutionalizes the value the cultures + + + align:start position:0% +institutionalizes the value the cultures +the processes in the standards that are + + align:start position:0% +the processes in the standards that are + + + align:start position:0% +the processes in the standards that are +put in place by these Founders so by + + align:start position:0% +put in place by these Founders so by + + + align:start position:0% +put in place by these Founders so by +doing this we get some continuity in + + align:start position:0% +doing this we get some continuity in + + + align:start position:0% +doing this we get some continuity in +fact 22 States now allow companies to + + align:start position:0% +fact 22 States now allow companies to + + + align:start position:0% +fact 22 States now allow companies to +incorporate as benefit corporations + + align:start position:0% +incorporate as benefit corporations + + + align:start position:0% +incorporate as benefit corporations +within their boundaries and we have at + + align:start position:0% +within their boundaries and we have at + + + align:start position:0% +within their boundaries and we have at +this point about + + align:start position:0% +this point about + + + align:start position:0% +this point about +786 such companies another option is + + align:start position:0% +786 such companies another option is + + + align:start position:0% +786 such companies another option is +employee ownership you've probably heard + + align:start position:0% +employee ownership you've probably heard + + + align:start position:0% +employee ownership you've probably heard +the term ESOP Employee Stock ownership + + align:start position:0% +the term ESOP Employee Stock ownership + + + align:start position:0% +the term ESOP Employee Stock ownership +programs well employee ownership uh + + align:start position:0% +programs well employee ownership uh + + + align:start position:0% +programs well employee ownership uh +companies build a commitment to being + + align:start position:0% +companies build a commitment to being + + + align:start position:0% +companies build a commitment to being +successful financially both for + + align:start position:0% +successful financially both for + + + align:start position:0% +successful financially both for +traditional investors and for employee + + align:start position:0% +traditional investors and for employee + + + align:start position:0% +traditional investors and for employee +owners right into the structure and + + align:start position:0% +owners right into the structure and + + + align:start position:0% +owners right into the structure and +governance of the firm employees often + + align:start position:0% +governance of the firm employees often + + + align:start position:0% +governance of the firm employees often +have Representatives on the corporate + + align:start position:0% +have Representatives on the corporate + + + align:start position:0% +have Representatives on the corporate +Boards of directors but the key to + + align:start position:0% +Boards of directors but the key to + + + align:start position:0% +Boards of directors but the key to +success of these companies is to make + + align:start position:0% +success of these companies is to make + + + align:start position:0% +success of these companies is to make +employees feel like owners by building a + + align:start position:0% +employees feel like owners by building a + + + align:start position:0% +employees feel like owners by building a +culture of Engagement of ownership of + + align:start position:0% +culture of Engagement of ownership of + + + align:start position:0% +culture of Engagement of ownership of +encouraging employees to make + + align:start position:0% +encouraging employees to make + + + align:start position:0% +encouraging employees to make +suggestions for improving the operations + + align:start position:0% +suggestions for improving the operations + + + align:start position:0% +suggestions for improving the operations +and the performance of the organization + + align:start position:0% +and the performance of the organization + + + align:start position:0% +and the performance of the organization +and therefore aligning the incentives + + align:start position:0% +and therefore aligning the incentives + + + align:start position:0% +and therefore aligning the incentives +through compensation and through the + + align:start position:0% +through compensation and through the + + + align:start position:0% +through compensation and through the +culture of the organization so employee + + align:start position:0% +culture of the organization so employee + + + align:start position:0% +culture of the organization so employee +ownership companies have spread across + + align:start position:0% +ownership companies have spread across + + + align:start position:0% +ownership companies have spread across +their country there are about 10,000 of + + align:start position:0% +their country there are about 10,000 of + + + align:start position:0% +their country there are about 10,000 of +them and you can find them in almost any + + align:start position:0% +them and you can find them in almost any + + + align:start position:0% +them and you can find them in almost any +industry that you can think of the key + + align:start position:0% +industry that you can think of the key + + + align:start position:0% +industry that you can think of the key +to employee ownership though is to make + + align:start position:0% +to employee ownership though is to make + + + align:start position:0% +to employee ownership though is to make +sure employees are involved and to also + + align:start position:0% +sure employees are involved and to also + + + align:start position:0% +sure employees are involved and to also +worry a bit that they don't uh put all + + align:start position:0% +worry a bit that they don't uh put all + + + align:start position:0% +worry a bit that they don't uh put all +of their financial resources for + + align:start position:0% +of their financial resources for + + + align:start position:0% +of their financial resources for +retirement into the same company you + + align:start position:0% +retirement into the same company you + + + align:start position:0% +retirement into the same company you +also want to spread your investment a + + align:start position:0% +also want to spread your investment a + + + align:start position:0% +also want to spread your investment a +bit so that you don't come up short if + + align:start position:0% +bit so that you don't come up short if + + + align:start position:0% +bit so that you don't come up short if +the company uh happens not to be as + + align:start position:0% +the company uh happens not to be as + + + align:start position:0% +the company uh happens not to be as +successful as you would like there are + + align:start position:0% +successful as you would like there are + + + align:start position:0% +successful as you would like there are +other kinds of companies called + + align:start position:0% +other kinds of companies called + + + align:start position:0% +other kinds of companies called +cooperatives a Cooperative is a company + + align:start position:0% +cooperatives a Cooperative is a company + + + align:start position:0% +cooperatives a Cooperative is a company +that has lots of owners that pull their + + align:start position:0% +that has lots of owners that pull their + + + align:start position:0% +that has lots of owners that pull their +resources to get some job they all need + + align:start position:0% +resources to get some job they all need + + + align:start position:0% +resources to get some job they all need +done uh done together so if you happen + + align:start position:0% +done uh done together so if you happen + + + align:start position:0% +done uh done together so if you happen +to grow up on a farm you may have been + + align:start position:0% +to grow up on a farm you may have been + + + align:start position:0% +to grow up on a farm you may have been +part of a milk Cooperative where Farmers + + align:start position:0% +part of a milk Cooperative where Farmers + + + align:start position:0% +part of a milk Cooperative where Farmers +pool their resources and create + + align:start position:0% +pool their resources and create + + + align:start position:0% +pool their resources and create +a dairy to take the milk from their + + align:start position:0% +a dairy to take the milk from their + + + align:start position:0% +a dairy to take the milk from their +dairy cows there are Sawmills in Oregon + + align:start position:0% +dairy cows there are Sawmills in Oregon + + + align:start position:0% +dairy cows there are Sawmills in Oregon +here in Cambridge we have the MIT uh + + align:start position:0% +here in Cambridge we have the MIT uh + + + align:start position:0% +here in Cambridge we have the MIT uh +Co-op and the Harvard Cooperative + + align:start position:0% +Co-op and the Harvard Cooperative + + + align:start position:0% +Co-op and the Harvard Cooperative +Society bookstores that sell books and + + align:start position:0% +Society bookstores that sell books and + + + align:start position:0% +Society bookstores that sell books and +reference material and clothing uh to + + align:start position:0% +reference material and clothing uh to + + + align:start position:0% +reference material and clothing uh to +our students and to our faculty and then + + align:start position:0% +our students and to our faculty and then + + + align:start position:0% +our students and to our faculty and then +there's my favorite Cooperative as my ti + + align:start position:0% +there's my favorite Cooperative as my ti + + + align:start position:0% +there's my favorite Cooperative as my ti +suggests it's the Green Bay Packers + + align:start position:0% +suggests it's the Green Bay Packers + + + align:start position:0% +suggests it's the Green Bay Packers +Green Bay Packers are a community-owned + + align:start position:0% +Green Bay Packers are a community-owned + + + align:start position:0% +Green Bay Packers are a community-owned +football team started in the 1920s and + + align:start position:0% +football team started in the 1920s and + + + align:start position:0% +football team started in the 1920s and +how else could you have a city Green Bay + + align:start position:0% +how else could you have a city Green Bay + + + align:start position:0% +how else could you have a city Green Bay +Wisconsin with only about 100,000 + + align:start position:0% +Wisconsin with only about 100,000 + + + align:start position:0% +Wisconsin with only about 100,000 +residents sustain a very successful + + align:start position:0% +residents sustain a very successful + + + align:start position:0% +residents sustain a very successful +highly competitive and often + + align:start position:0% +highly competitive and often + + + align:start position:0% +highly competitive and often +championship football team for all of + + align:start position:0% +championship football team for all of + + + align:start position:0% +championship football team for all of +these years it's because they are owned + + align:start position:0% +these years it's because they are owned + + + align:start position:0% +these years it's because they are owned +by the community and they can't be sold + + align:start position:0% +by the community and they can't be sold + + + align:start position:0% +by the community and they can't be sold +to some higher bidder who might make a + + align:start position:0% +to some higher bidder who might make a + + + align:start position:0% +to some higher bidder who might make a +profit off of it you also see some + + align:start position:0% +profit off of it you also see some + + + align:start position:0% +profit off of it you also see some +cooperatives in other countries probably + + align:start position:0% +cooperatives in other countries probably + + + align:start position:0% +cooperatives in other countries probably +the most famous one is the mandon + + align:start position:0% +the most famous one is the mandon + + + align:start position:0% +the most famous one is the mandon +set of Industries headquartered in The + + align:start position:0% +set of Industries headquartered in The + + + align:start position:0% +set of Industries headquartered in The +Basque region of Spain with companies + + align:start position:0% +Basque region of Spain with companies + + + align:start position:0% +Basque region of Spain with companies +that range from manufacturing to retail + + align:start position:0% +that range from manufacturing to retail + + + align:start position:0% +that range from manufacturing to retail +to high-tech to financial institutions + + align:start position:0% +to high-tech to financial institutions + + + align:start position:0% +to high-tech to financial institutions +they have uh over 81 different companies + + align:start position:0% +they have uh over 81 different companies + + + align:start position:0% +they have uh over 81 different companies +at the moment so we can build + + align:start position:0% +at the moment so we can build + + + align:start position:0% +at the moment so we can build +organizations in different kinds of ways + + align:start position:0% +organizations in different kinds of ways + + + align:start position:0% +organizations in different kinds of ways +and so the takeaway lesson that I hope + + align:start position:0% +and so the takeaway lesson that I hope + + + align:start position:0% +and so the takeaway lesson that I hope +you will have hear from this + + align:start position:0% +you will have hear from this + + + align:start position:0% +you will have hear from this +conversation is that it's possible if + + align:start position:0% +conversation is that it's possible if + + + align:start position:0% +conversation is that it's possible if +you are imaginative perhaps you can + + align:start position:0% +you are imaginative perhaps you can + + + align:start position:0% +you are imaginative perhaps you can +invent the new forms of organizations + + align:start position:0% +invent the new forms of organizations + + + align:start position:0% +invent the new forms of organizations +for the future that will meet the needs + + align:start position:0% +for the future that will meet the needs + + + align:start position:0% +for the future that will meet the needs +of all of their stakeholders and will be + + align:start position:0% +of all of their stakeholders and will be + + + align:start position:0% +of all of their stakeholders and will be +will be built to last for multiple + + align:start position:0% +will be built to last for multiple + + + align:start position:0% +will be built to last for multiple +generations and in doing so not only + + align:start position:0% +generations and in doing so not only + + + align:start position:0% +generations and in doing so not only +might you build organizations that work + + align:start position:0% +might you build organizations that work + + + align:start position:0% +might you build organizations that work +for investors customers and employees + + align:start position:0% +for investors customers and employees + + + align:start position:0% +for investors customers and employees +but maybe ones that help to sustain our + + align:start position:0% + + + + align:start position:0% + +planet e \ No newline at end of file diff --git a/d_Mg_JnnevU.txt b/d_Mg_JnnevU.txt new file mode 100644 index 0000000000000000000000000000000000000000..30989cad81ab65ccd0a8488c8aa8f9db8525454a --- /dev/null +++ b/d_Mg_JnnevU.txt @@ -0,0 +1,3348 @@ +PROFESSOR: Good moRning. + +Again, we're left with +a little stub of + +chapter six to finish. + +This was our first chapter on +binary linear block codes. + +Very briefly, last time we +developed the family of RM, + +Reed-Muller codes, parameterized +by R and M. + +These are codes of length two +to the M, and distance 2 to + +the M minus R for all reasonable +combinations of M + +and R, integers. + +And the reason I do these first +is because it gives us a + +nice big -- in fact, +infinite -- + +family of codes that kind +of cover the waterfront. + +Let us see what we can +reasonably get in terms of the + +parameters n k d in codes. + +And, of course, n k t d tell us +most of what we know, want + +to know about the performance +of moderate complexity codes + +in terms of coding gain. + +And it's easy to see that among +these codes, we have + +sequences in which the coding +gain goes -- the nominal + +coding gain goes to infinity. + +And we also know that there's +at least one sequence, the + +bi-orthogonal sequence, for +which the effective coding + +gain completely closes the +gap to the Shannon limit. + +And in all likelihood, there +are many such sequences, + +though I'm not aware of the +actual result there. + +So it seems like we might be +almost finished here, except I + +asked about what possible fly +there could be in this + +ointment last time. + +And one of you alertly reported +that we still really + +hadn't worried about decoding. + +And the implicit decoding +algorithm here is minimum + +distance decoding. + +Exhaustive minimum distance +decoding. + +We basically have to compute the +minimum distance to each + +of the 2 to the k code words. + +And that's going to get a little +tedious as soon as k + +gets up to 16 or 107 +or whatever. + +So it was recognized pretty +early in the development of + +coding theory that this was +the essential problem. + +The problem is not to construct +codes whose + +performance under maximum +likelihood decoding is near + +that of the Shannon limit +-- you can use + +random codes for that. + +But in constructing these more +algebraically structured + +codes, what we're really trying +to do is to facilitate + +the decoding problem, which +is the central problem. + +We need to find a +decoding method + +that is actually feasible. + +And, of course, Shannon didn't +address that at all. + +He just addressed the ultimate +potential of these codes with + +the optimal decoding technique +and didn't worry about its + +complexity. + +All right. + +So I'd say the fundamental +problem here is decoding + +complexity. + +Now, one of the -- + +an awful lot of the early work +on coding was about binary + +codes, of course. + +But it also considered them in +the context of binary decoding + +algorithms. + +In other words, what's assumed +is what you send as a series + +of bits and what you receive +as a series of bits. + +That's not the picture we have +here in this course, where + +what we receive is a series +of real numbers. + +Because we're going over a +continuous additive white + +Gaussian noise channel. + +Of course, there are channels +which are inherently digital, + +at least by the time the coding +engineer can get his + +hands on them. + +What he's presented with +is a string of bits. + +So it makes sense to consider +codes for bit error + +correction. + +Classic codes of this type +are, first of all, the + +repetition code. + +If I send this -- + +if I use the 7 1 7 code, the +repetition code of length 7, + +I'm going to be able to correct +up to three errors. + +Three bit errors. + +Because four bits are still +going to be correct. + +In a majority vote, we'll +do the decoding. + +Most of you have probably +seen Hamming codes. + +These are codes with minimum +Hamming distance 3. + +That means if you make one +error, you're still within the + +Hamming sphere of radius 1 +around the original code word. + +That's disjoined from all the +other Hamming spheres, and so + +in principle you ought to be +able to do single error + +correction with Hamming codes. + +And there are very simple +algorithms for doing that. + +OK. + +But that may be what +you have to do. + +The final point of chapter six +is that in the additive white + +Gaussian noise context, +that's not what you + +want to do at all. + +And I just want to say a few +words about that because this + +is one of the Achille's heels +of a lot of classical coding + +theory, which was addressed +to the binary + +in, binary out situation. + +So let's talk about the penalty + +for making hard decisions. + +That is, by hard decision, we +mean a binary decision. + +0, 1, plus or minus 1. + +And I'll do this fairly quickly, +but in a way that I + +hope will stick. + +Let me draw our block diagram +of our coding scheme. + +We've got a code. + +We've got an encoder, +which basically + +puts out a code word. + +An n-tuple in the code. + +I'm going to consider +the individual + +elements of this n-tuple. + +They're just elements of the +binary field F2 And we go + +through our standard 2-PAM map, +which maps them to s of + +xk, which is going +to be in plus or + +minus alpha in general. + +Just plus or minus 1. + +Doesn't matter up to scaling. + +In order to send them, we're +going to send this sequence of + +real numbers over the white +Gaussian noise channel. + +And as a result, we're +going to get out s -- + +let's call it a received +symbol -- + +rk, which is the transmitted +symbol plus some Gaussian + +noise symbol, nk. + +This is a real number. + +And then -- + +then what we do? + +Now we're into the decoder. + +This is what we received, so +it's free to us to choose what + +to do next. + +I'm going to say observe, first +of all, that without + +loss of generality, we +can decompose rk + +into a sign and magnitude. + +So this out here is going +to be a sign of rk. + +And this is going to be +the magnitude of rk. + +And let me just give +this a name. + +Let me call this yk, and let +me call this beta k. + +OK. + +So what is this? + +This is in plus or minus 1, and +this is in the positive + +reals, so the non-negative +reals. + +OK. + +And clearly, if I keep both of +these, I haven't lost any + +information. + +This is just a way of +representing rk in sign and + +magnitude form. + +Now, this is what's called +the hard decision. + +Actually, let me do +this differently. + +Let me pass this through the +inverse to a 2-PAM map. + +So out of this, I get a yk, + +which is in F2 OK. + +Either of these -- + +the real sign or the binary +hard decision -- + +could be considered to +be the hard decision. + +Now, what am I doing here? + +I'm saying, well, if you force +me to make a guess on whether + +this individual transmission was +sending a 0 or 1, this is + +the most obvious guess. + +If I send -- + +here's minus 1, here's our minus +alpha, here's plus 1 -- + +if I sent a plus 1, then my +maximum likelihood per bit + +decision would be to decide +the plus 1 was sent. + +If I get a positive sign in -- + +what I'm really mapping here is +rk, and minus 1 if I get a + +negative side. + +So that's what's called +a hard decision. + +I'm going to decide right here +what I think it was, what it + +most likely was. + +And this is the best +way to do it. + +Just take the sign. + +This here is a real valued +weight, often called the + +reliability, which is +helpful to retain. + +That's the main point +of what I'm going + +to talk to you about. + +If this is 0 -- + +that means what we received +was right on this boundary + +between the positive and +negative side -- + +then the reliability is 0. + +In likelihood terms, that means +it's equally likely that + +what was sent was a plus +1 or a minus 1. + +So in some sense, we get +no information when the + +reliability is 0. + +Fails to discriminate between +plus 1 and minus 1. + +The larger this is, the further +we get out here. + +Or symmetrically, the further +we get out here, the more + +certain we are that in that +particular symbol, neither a + +plus or a minus was sent. + +OK And it actually tuRns out, +if you work out the Gaussian + +numbers, that beta k is the +log likelihood ratio up to + +scale of the more likely +versus the log of the + +likelihood, or the more likely +versus the less likely symbol. + +So it has a minimum of 0. + +The bigger it is, the +more reliable. + +So it's natural to call +it the reliability. + +OK. + +An awful lot of traditional +algebraic decoding neglects + +this channel down here. + +It just says, OK, let's take +these hard decisions and try + +to decode them. + +If you've previously had a +coding class, then that's + +probably what they did. + +Or they assumed a context in +which this was never available + +in the first place. + +And my only point here, my main +point, is that that's a + +very bad thing to do. + +How can we evaluate that? + +Suppose we just take this top +channel and don't look at the + +reliability. + +Then basically we have the +channel model becomes a binary + +symmetric channel. + +We have bits in, bits out, and +we have probably one minus p + +that if we send a +0 we get a 0. + +And since it's symmetric, +the same probability -- + +if we send a 1, we get a 1 -- + +and a probability p of +making an error. + +So we get the traditional +memoryless binary symmetric + +channel model. + +We can compute the capacity of +this model and compare it to + +the capacity of the additive +white Gaussian channel -- + +this model. + +And depending on the signal to +noise ratio, from a capacity + +calculation, we find that +there is of the order + +of 2 or 3 dB loss. + +Well, as we go on in this +course, we're going to find + +that 1 dB is a very worthwhile +coding game. + +So to throw away 2 or 3 dB just +by throwing away this + +information, is a +bad thing to do. + +I can make this point in a +different way by simply + +looking at what's the optimum +decision rule. + +For say, let me take very simple +code, just the 2-1-2 + +repetition code. + +That's just 0,0,1,1. + +This is the code where you +either send plus, plus, plus + +alpha, plus alpha, or minus +alpha, minus alpha. + +And what's the decision +region? + +It's obviously this +45 degree line. + +And what is this squared +distance to + +any decision region? + +It's 2 alpha squared, right? + +So basically, the probability +of making an error is the + +probability that the noise +variable has a magnitude in + +this dimension, and in this +direction, greater than the + +square root of 2 +alpha squared. + +You've been through all those +calculation several times now. + +All right. + +So this is -- if I keep +reliability info -- in other + +words, if I keep the full +received signal -- if I + +discard reliability, then +basically what can I get out? + +Then my y, as I say, is in +0, 0, 0, 1, 1, 0, 1, 1. + +There are only four possible +things I can see in two + +transmissions through +this channel. + +They're all binary two-tuples. + +And what does that mean? + +That means if my actual r is +in this quadrant, then I'm + +going to make a hard decision +of 0 and 0 both times. + +So I'm going to say I'm +in this quadrant. + +And likewise, I'm basically +going to decide which of these + +four quadrants I'm in, and +that's all the information the + +decoder is going to have. + +So here I am at this +point here. + +Now the decoder simply knows, +via these two bits, which + +quadrant you're in. + +Now, it has to decide +which of these two + +code words were sent. + +What's its maximum likelihood +decision rule given just this + +information? + +AUDIENCE: 0, 0, [INAUDIBLE] + +0, 0, [INAUDIBLE] + +1, 1, 1, 1, 1. + +And in the other +case, any one. + +PROFESSOR: OK. + +That's correct. + +So clearly, if you land +in this quadrant, + +you decide 0, 0. + +Now, if you land down +here, you decide + +1, 1 in this quadrant. + +And what am I going to +do here or here? + +Actually, here the evidence +is totally balanced. + +I have nothing that tells +me whether to + +go one way or another. + +I could make an arbitrary +decision in the hope of + +minimizing my error +probability. + +Flip a coin. + +But whichever decision I make, +what I'm going to find is that + +there's a probability of error +that -- there's a certain + +noise, namely the noise that +takes me from here to this + +decision boundary that is +going to cause an error. + +Or if I decide the other way, it +would be the one that goes + +from here to here. + +So I'm going to be stuck. + +There are going to be certain +noise variables of length, + +now, merely alpha, or square +distance alpha squared, that + +are going to cause me to make a +decision error, ultimately. + +Regardless of how I set up +this final block here. + +Decoder. + +Whatever rule I give to this +decoder, it's only going to + +take, worst case, a noise of +squared magnitude alpha + +squared to cause an error. + +AUDIENCE: +[UNINTELLIGIBLE PHRASE] + +PROFESSOR: That's right. + +I shouldn't have thrown +this away. + +That's the elementary point +I'm trying to make here. + +All right. + +AUDIENCE: +[UNINTELLIGIBLE PHRASE] + +the distance, d_min is +different, essentially. + +I mean, we can put +it that way. + +PROFESSOR: That's where I'm +going, is that the effective + +minimum squared distance here +is 2 alpha squared. + +And this is what shows up in +our union-bound estimate in + +all of our -- + +we do this kind of minimum +distance decoding. + +But if I throw away this +important information, then my + +effective minimum +squared distance + +is only alpha squared. + +That is the bottom line here. + +In dB terms, how much +of a cost is that? + +3 dB, right? + +So I've cost myself a factor +of 2 in noise margin. + +So 3 dB loss. + +Because of lack of time, I won't +go through the argument + +in the notes, which shows that, +in fact, exactly the + +same thing occurs for any -- + +whenever the minimum Hamming +distance is even here in this + +code that I started from, +you lose precisely 3 dB. + +It's not quite as clean an +argument when the minimum + +Hamming distance is odd. + +Then you lose up to 3 dB, and +it goes to 3 dB as the + +distance increases. + +But there's a very, pretty +elementary geometric argument + +that hard decisions, again, cost +you 3 dB loss, which is + +consistent with what +the capacity + +calculation gives you. + +All right. + +Well, obviously the reason we +did this is we were trying to + +simplify things. + +What would be the first step to +unsimplify things and get + +some of this loss back? + +Let me suggest that what this +amounts to is a two-level + +quantization of the received +real number rk. + +What's the next number +higher than 2? + +Integer. + +AUDIENCE: 3. + +PROFESSOR: 3. + +All right. + +How about a 3 level +quantization here? + +OK. + +So what we're talking about is +a highly quantized magnitude + +where instead of just making a +decision boundary here, which + +is effectively what we did for +2 level quantization, let's + +make some null zone here between +some threshold plus t + +and some threshold minus t. + +And we'll say, in this region, +the received symbol is + +unreliable. + +OK. + +That's called an erasure. + +So we make a quantized +magnitude where rk -- + +doesn't fit so neatly here. + +Let me just say this quantized +magnitude is going to give me + +out something which is either +going to be minus 1, + +a 0, or plus 1. + +It's going to be three levels, +this is minus 1, 0, plus 1. + +Or I don't want the +minus 1 there. + +The reliability is either a +fixed reliability, or it's 0. + +OK. + +So now I've got a channel model +that looks like this. + +If you work it out, it's called +the binary erasure + +channel with errors. + +All transitions are possible. + +I can send a 0,1. + +I can receive, let's call it, +a 0, a 1, or a question mark + +for -- this is called +an erasure. + +And this is 1 minus p minus q, +and this is p and this is q + +symmetrically, for some p and +q, which you can evaluate. + +And let's choose this threshold +t to optimize things + +and get the maximum capacity. + +Now if you do the capacity +calculation, you'll find + +there's only 1 to 1.5 dB loss. + +Again, depending on the +signal to noise ratio. + +So in effect, you've already +bought back, just with this + +very simple method, half of the +loss that you inflicted on + +yourself by making +hard decisions. + +So making erasures is a good +first step towards correcting + +this problem. + +And let's think about it again +for this simple code. + +Suppose I establish these +thresholds at + +plus t and minus t. + +Plus t and minus t. + +So now when I consider the +problem that the decoder has, + +I have nine possible regions, +all right, each with three + +possible decisions in +two dimensions. + +And so what's my decision +rule going to be now? + +For this 0, 0 decision, I'm +going to include, of course, + +this region. + +But now if I land in this +region, that means one of the + +received symbols was erased, +but the other one gave me a + +definite indication. + +So the weight of evidence +still goes up here. + +And similarly, like so. + +So my decision region for 0 -- + +definitely for 0, 0 +is this region. + +And my decision region +definitely for 1, 1 is the + +symmetric region. + +And, of course, I still have +three regions where I really + +can't say anything. + +This is two erasures. + +This is 0, 1 -- + +two conflicting pieces +of evidence. + +This is 1, 0 -- two + +conflicting pieces of evidence. + +So I still have to flip +a coin out in here. + +But how I improve things, that's +measured by what's the + +minimum distance to -- + +what's the minimum size of +error it takes to make a + +decision error. + +And that's going to be either +this length or this length. + +You see that? + +Just pretty clear, +intuitively? + +So the game here is we first of +all choose t so that these + +two lengths are the same. + +That's done by squeezing t. + +You see these go in opposite +directions as t + +is raised or lowered. + +So we find the t such that +these two are the same. + +Having equalized t, we find some +value for the effective + +minimum squared distance, which +is between alpha squared + +and 2 alpha squared. + +As I remember, this somehow +gains about 1.5 dB. + +The moral is about the same. + +You can get about half of your +loss back by using erasures. + +And again, this holds for any +code which has an even minimum + +Hamming distance, if +you can accept + +this method of analysis. + +All right. + +So a first step, even if you +want to stay in the binary + +world, is to allow yourself +to use erasures as well. + +That will claw back half of the +loss that you might have + +incurred by using +hard decisions. + +And, of course, even better +would be to use a more highly + +quantized reliability and +somehow have a decoding + +algorithm that can use +soft decisions. + +Soft decisions are decisions +that have reliability metrics + +attached to them. + +And in the early +days of coding, + +people evaluated capacity. + +They evaluated this +sort of thing. + +And it was pretty generally +agreed that eight level + +quantization was going to be +practically good enough. + +16 levels, certainly +good enough. + +Nowadays you typically +go up to 64 levels. + +You might go up to much higher +numbers if you have little + +other things to worry +about like timing + +recovery and so forth. + +But if you're purely in a +synchronized, symbol by symbol + +transmission, then three or +four bits of reliability + +information are going +to be enough. + +So from an engineering +point of view, that's + +a good way to go. + +Now, of course, you're going to +need a decoding algorithm + +that can use soft decisions. + +So as we go along, I'm going to +talk about error correcting + +decoding algorithms that are not +much, because correcting + +errors only is a very bad +thing to do here. + +Errors and erasure. + +Correcting decoding algorithms, +which are fairly + +easy in algebraic +code context. + +And then finally soft decision +decoding algorithms, which is + +the kind we really want +on this channel. + +We really want to use +the soft decisions. + +We can't afford these +huge losses. + +We can't even afford 1 to +1 and a 1/2 dB loss. + +OK, so there's more set on +this in the last part of + +chapter six, but that's +all the time I want to + +spend on it in class. + +Does anyone have +any questions? + +yes? + +AUDIENCE: [INAUDIBLE] + +transformation before we do +the quantization, can we + +change the shape of the +[UNINTELLIGIBLE] + +regions such that we can +further improve the + +[INAUDIBLE PHRASE] + +improve the decoding? + +PROFESSOR: Well, that's +an interesting idea. + +But think about it from +an information + +theoretic point of view. + +Can you actually get more +information by introducing a + +one-to-one transformation, +whether it's linear or + +nonlinear, whatever? + +AUDIENCE: The point is, the +original quantization is based + +on a straight line, +[INAUDIBLE PHRASE]. + +[UNINTELLIGIBLE PHRASE]. + +PROFESSOR: You want to put a +curved line on this plane? + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: OK. + +That's going to imply decisions +that are not symbol + +by symbol decisions. + +That's going to imply that you +need to save r1 and r 2 in + +order even to just decide where +you're in this and then + +go through some kind of +quantization on the plane. + +And once you've got r1 and r2 +and you're trying to draw + +crazy boundaries, I suggest it's +going to be simpler to + +just compute the Euclidean +distance to each of these + +points, which results in +this decision region. + +AUDIENCE: [INAUDIBLE PHRASE]. + +PROFESSOR: OK. + +I don't see the rationale for +it yet, but there's been a + +million innovations in this +business, and you + +might have a good idea. + +Any other comments? + +I really appreciate comments +that go anywhere. + +I like to address them now +when they're ripe. + +OK. + +So let's go on to chapter +seven and eight. + +[UNINTELLIGIBLE] here. + +Chapters seven and eight +are closely related. + +This is really my bow to +algebraic coding theory. + +I expect that if any of you +have had a close course in + +coding before, that it +was primarily on + +algebraic coding theory. + +How many of you have +had a course in + +coding theory before? + +One, two, three. + +Not so many. + +Was it on algebraic +coding theory? + +Yes? + +AUDIENCE: I [UNINTELLIGIBLE] +two, one + +engineering and one algebraic. + +PROFESSOR: Excuse me? + +AUDIENCE: Two -- one for -- +actually, two algebraic and + +one out of kind of this stuff. + +PROFESSOR: OK. + +Well, you're a ringer then. + +What was the one +on this stuff? + +AUDIENCE: It was out +of Wicker's book. + +PROFESSOR: Out of? + +AUDIENCE: Wicker's book. + +PROFESSOR: Wicker's book +on turbo codes. + +AUDIENCE: No, the data +storage one. + +PROFESSOR: Data storage. + +OK. + +I don't know that book. + +But it talks about sophisticated +soft decision + +type coding, and so forth. + +What was the course you took? + +AUDIENCE: Algebra. + +PROFESSOR: Algebraic. + +OK. + +All right. + +Well, let me just make a broad +brush comment, which may or + +may not be supported +by your previous + +exposure to coding theory. + +Which is that for many, many +years, when people said coding + +theory, they meant algebraic +coding theory, coding theory + +of block codes that are +constructed by algebraic + +techniques like Reed-Muller +codes, like Reed-Solomon + +codes, BCH codes, +cyclic codes. + +And if you said, I want to +leaRn some coding theory, + +asked your graduate student to +go buy a textbook for you, + +it's probably going to +be a textbook on + +algebraic coding theory. + +Meanwhile, there was a bunch +of us who were off actually + +trying to construct codes +for real channels. + +And conceRning with really how +complex this is to implement, + +and what kind of performance +can we really get. + +And we hardly ever used +algebraic codes. + +Initially, we used convolutional +codes with + +various kinds of decoding +algorithms, threshold + +decoding, sequential decoding, +the Viterbi algorithm. + +And these get more and more +elaborate, and then finally + +the big step, well, the big +step was to capacity + +approaching codes. + +Which now people are starting to +call modeRn coding theory. + +Long, random-like codes +that have an + +iterative decoding algorithm. + +And that's what we'll +get to towards + +the end of this course. + +So from an engineers point of +view, to some extent, of all + +this work on n k d and algebraic +decoding algorithms + +and so forth was a massive +distraction. + +It really missed the point. + +Sometimes because it assumed +hard decisions. + +Or after assuming hard +decisions, it assumed bounded + +distance decoding algorithms. + +But it was all -- + +from Shannon's perspective, it +was too deterministic, too + +constructed, too structured. + +You want more random elements +in your coding scheme. + +However, two things: one, this +theory is a beautiful theory, + +both the mathematical theory +of finite fields and the + +coding theory, particularly of +Reed-Solomon codes, which are + +uniquely the greatest +accomplishment of algebraic + +coding theory, and which have +proved to be very useful. + +And B, Reed-Solomon codes are +something that as engineers, + +ought to be part of your tool +kit, and you will find very + +useful a variety +of situations. + +So the objective of this part of +the course is, within some + +proportion within the overall +scheme of the course, to give + +you exposure to this +lovely theory. + +You can leaRn all about it just +by reading a book or two. + +Probably less than one book. + +And to give you some exposure +to Reed-Solomon codes, which + +have been used in practice. + +For more than 20 years, the +deep space standard was a + +concatenated code. + +That means a sequence of two +codes, of which the inner code + +was a convolutional code +decoded by the Viterbi + +algorithm, which we'll talk +about after this. + +And then the outer code, the +code that cleans up errors + +made by the inner code, was a +Reed-Solomon code of length + +255 over the finite field +with 256 elements. + +And that's the dynamite +combination that dominated the + +power-limited coding world +for at least 20 years. + +So you ought to know, +as a minimum, about + +Reed-Solomon codes. + +So that's my objective +in going through + +these next two chapters. + +However, because these have +not basically been on the + +winning path to get to the +Shannon limit, I'm trying to + +limit it to three weeks max. + +And therefore, that means that +the presentation is going to + +be a lot faster than what +you're used to. + +I'll probably do as much in +these three weeks as most + +people do in a term in +an entire algebraic + +coding theory course. + +That's an exaggeration -- + +people do a lot more -- but I +try to at least hit all the + +main points that you +need to know. + +So I apologize in advance if it +seems that now we're on a + +very fast moving train. + +But you ought to know +this stuff. + +You ought not to spend +too much time on it. + +I'm trying to reconcile those +two points of view. + +Any questions or comments? + +All right. + +Let's go. + +Chapter seven. + +We go through a series +of algebraic objects. + +First, the integers, +then groups. + +You certainly ought to know -- +you do know about integers. + +You ought to know about groups, +at least a little bit. + +Let's see. + +What's next? + +Then fields, particularly +finite. + +Then polynomials over fields, +particularly finite. + +And then finally, from this we +actually get to construct + +finite fields. + +And these are all things that +you'll encounter again and + +again, have encountered. + +I think you've probably +encountered everything except + +possibly for groups +and finite fields. + +You certainly encountered +polynomials over real and + +complex fields. + +And so in some sense, this is +a broadening of what you + +already know. + +So I assume we start with the +integers for two reasons. + +One is you already know about +the factorization properties + +of the integers. + +We're going to -- + +that leads to a little bit of +number theory, which we're + +going to use when we talk about +groups, finite groups, + +cyclic groups. + +So this is just to remind +you, but it's + +also to put up a template. + +And we're going to find the +algebraic properties of + +polynomials are very, +very similar to + +those of the integers. + +This is because they're +both rings. + +They're both in fact principal +ideal domains. + +They're Euclidean domains. + +They both have a Euclidean +division algorithm as their + +key mathematical property. + +And so pretty much any time you +want to develop a result + +about the polynomials, you can +start from the comparable + +results that you know about the +integers and just change + +the notation. + +And you'll have a sketch of +the proof for polynomials. + +So it's important to remind +ourselves about + +the integers first. + +Now, when I say the +factorization properties of + +the integers, I'm not talking +about anything more + +complicated than what you +leaRned in grade school. + +I just want to introduce +a few terms. + +We have the notion +of divisors. + +a divides b means that a times +some quotient equals b. + +I could be talking about plus or +minus, positive or negative + +integers here. + +Everything divides 0. + +OK. + +We have the idea of units, +which are the invertible + +integers under multiplication. + +And what are those? + +Which integers have a +multiplicative inverse? + +[UNINTELLIGIBLE] + +any of them? + +AUDIENCE: [INAUDIBLE PHRASE]. + +PROFESSOR: [INAUDIBLE]. + +All right. + +That's a little exercise that +shows you that, in general, + +the invertible elements of any +set that has an operation like + +multiplication form a group. + +[INAUDIBLE] group thing, these +clearly form a group under + +multiplication that's +isomorphic + +to the binary group. + +Well, in fact, we've already +been using it -- + +F2. + +OK. + +So we have units, and whenever +we talk about the divisors, + +factorization, primes, +so forth, + +the units are a nuisance. + +Because we can always multiply +things by units and it doesn't + +affect factorization +properties. + +This is [UNINTELLIGIBLE] a +little bit more out there. + +What I eventually want +to get to is -- + +skipping a few things that +are said in the notes -- + +is unique factorization. + +Maybe before that I should +define primes: + +are positive integers. + +The reason we stay positive +is, again -- + +of course, we could have a +negative prime integer, but + +let's pick a unique +representative of two units. + +Positive integers -- + +I should've said in the notes +greater than 1, we don't + +consider 1 to be a prime -- + +that have no non-trivial +divisors. + +And, of course, every integer +has trivial divisors. + +Namely, plus or minus 1 and +plus or minus itself. + +Let me give this a name. + +i. + +Not a very good name. + +How about n? + +So if we have any integer n, +it's divisible by plus or + +minus one, plus or minus n -- + +that doesn't count. + +So a prime is an integer that +doesn't have any other + +divisors than these +trivial ones. + +And then I want to get to unique +factorization, which + +I'll just state, not prove. + +Which is that every integer +is equal to a + +unique product of primes. + +And we always have to +add up to units. + +We can add as many plus or minus +1's to the product as we + +want, as long as we have +an even number of them. + +And we'll have another +factorization, so here, we + +want to exclude the units. + +And then we have unique +factorization. + +OK. + +This is all grade school +stuff, high + +school stuff maybe. + +Again, when I go through +polynomials, you'll see there + +is a set of concept +exactly like this. + +Now, where we want to get to +is mod-n arithmetic, which + +again, you all know +about, I assume. + +This is based on the fact -- + +we can think of it as being +based on Euclidean division + +algorithm, which basically +proves that given any two + +integers m and n, we can write m +as some qn plus r where 0 is + +less than or equal to r, less +than or equal to n minus 1, + +and is called the remainder +of m, modulo n. + +And how is this proved? + +Let's say these are both +positive integers. + +Say m is a big integer, +n is a small integer. + +We just keep subtracting integer +multiples of n from m + +until we -- + +you know, the remainder will +start decreasing until we get + +the remainder in this range, and +it's obvious that we can + +always get a remainder +that's in that range. + +And further, that this +decomposition is unique under + +this restriction on r. + +All right. + +So we write the m is congruent +or equivalent to r mod n. + +That means it differs from r by +a multiple of n where r is + +unique and r is in the set 0, 1, +up through n minus 1, which + +we say are the residue +classes mod n. + +It has to be one of +those n things. + +OK? + +No one is having the slightest +trouble with this, right? + +Boring. + +You've seen it all before. + +I hope. + +OK. + +So now you ask, suppose m equals +r mod-n, and some other + +w equals s mod-n. + +What is m plus w mod-n, and you +quickly prove that it's + +equal to r plus s mod-n. + +By transferring, by just +checking the properties of + +ordinary arithmetic, you can use +this kind of expression: m + +must equal something +times n plus r. + +w must equal something +times n plus s. + +So if we add m plus w, we're +going to get something times n + +plus r plus s. + +And that is, by definition, +going to be r plus s mod-n. + +So we get a well-defined +addition rule for these + +residues, for the elements of +this set of n residues Rn, or + +remainders. + +OK, so addition is +well-defined. + +And similarly, multiplication +is well-defined. + +mw mod-n, again, you can prove +-- and this is done + +in the notes -- + +that if mw mod-n can be +found by taking rs and + +reducing it, mod-n. + +Maybe I should have congruent +signs here, but I + +won't worry about it. + +So this is mod-n, addition +and multiplication. + +So what this says is that Rn, +combined with this mod-n + +addition operation, which in the +notes I write in that way, + +and this mod-n multiplication +operation -- + +this is a well-defined set of n +elements with a well-defined + +addition operation and +a well-defined + +multiplication operation. + +And I don't prove any properties +about it here, but + +I come back to prove that this +has almost all of the + +properties that we +want of a field. + +In fact, if n is a prime, it +does have the properties that + +we want of a field. + +So we'll later prove that the +finite field with p elements + +is simply rp with mod-p addition +and multiplication. + +And, of course, for the +particular case p equals 2, we + +already have a lot of experience +with this. + +That's how we get the +binary field. + +We just take the 0 and 1, +considered as residues mod-2. + +And then the field addition and +multiplication operations + +give us something that +satisfies the + +axioms of the field. + +We'll find that works for every +prime, and it doesn't + +work for non-primes. + +Can anyone quickly see why this +isn't going to work for + +non-primes? + +Suppose n equals 6. + +Anyone quickly see why this set +under these two operations + +isn't going to be a field? + +This, of course, assumes that +you know what a field is, + +which we haven't actually +said yet. + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: Excuse me? + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: There's no inverse. + +In a field, every non-zero +element has to have an + +inverse, just like in the +real and complex field. + +But in the integers mod-6, 3 +times 2 is equal to 6, which + +is equal to 0. + +So there are two non-zero +elements that multiplied + +together give 0. + +And that means that neither 3 +nor 2 can possibly have a + +multiplicative inverse. + +So that's why you have +to have a prime. + +This doesn't happen, of course, +if n were a prime. + +OK. + +So that's just a little warm +up to remind you what mod-n + +arithmetic is like. + +And in particular, this is going +to be the key element of + +a lot of proofs -- + +the Euclidean division +algorithm -- + +both for integers and +for polynomials. + +OK. + +So that, I hope, was review. + +Now we're going to talk +about groups. + +So let's do it. + +How many of you feel you +know what a group is? + +Less than half the class. + +OK. + +Well, we've been talking about +groups so far here, but let's + +take a little bit more of +an axiomatic approach. + +In the notes, I actually give +two possible sets of axioms + +for a group. + +Let me start with +a standard one. + +You've heard of something called +the group property in + +this course. + +Well, first of all, what am I +talking about when I'm talking + +about a group? + +I'm talking about a set, g, +and I'm also talking about + +some operation on that set, +which I'll use the mod + +addition circle-plus as +the group property. + +Even if it's multiplication or +matrix inversion or -- no, it + +couldn't be matrix inversion. + +What this means is that if we +take any two elements of the + +group, then a plus b +is well-defined. + +So you can think there's +a table. + +Here are the elements +of the group. + +a, b, c, d, e. + +a, b, c, d, e. + +And at this point, all we +know is that we can + +fill out the table. + +We get something that +goes in all here. + +All right? + +So that defines the group. + +AUDIENCE: [INAUDIBLE PHRASE]. + +PROFESSOR: That means if I +give a and b, then the + +quantity a plus b is -- + +I can tell you what c is. + +There's a unique element in +each of the cells of this + +addition table, or +the group table. + +OK. + +Group property, also called +closure, is the obvious one. + +What's an elementary condition +of what all these sums have to + +be for this to be a group? + +Have to be all in the group. + +If I say I have a group that +consists of 1,2,3,4,5, + +1,2,3,4,5 and my group +operation is ordinary + +addition, then I can certainly +fill out the table. + +And I get 2,3,4,5,6 -- + +whoops. + +Yeah, that's the element that's +not in the group. + +So in order to have a +group, I want a -- + +I mean, it's a plus b is in +the group, all a and b. + +So the group is closed +under addition. + +This was the property we used to +define linearity for binary + +linear block codes. + +The sum of any two n-tuples +had to be another + +n-tuple in the code. + +We have the associativity +operation. + +This is a requirement on the +binary operation, really. + +a plus b plus c has got to be +equal to a plus b plus c. + +In other words, you can get +rid of the parentheses. + +And this, an expression like +that, is meaningful. + +It doesn't matter how you group, +whether you add these + +two things first and then that, +or add these two things + +first and then that. + +Maybe now is a good time to +talk about the special + +property, which is +not an axiom. + +So let me call it x abelian, or +the commutative property. + +This is true if a plus +b is equal to b + +plus a, all a, b group. + +Now this is, of course, true +for ordinary addition and + +ordinary multiplication. + +It's not true for matrix +multiplication. + +Say if I have a group of +matrices, then in general, ab + +is not equal to ba. + +So for some groups this +holds, for some + +groups it doesn't hold. + +In this course, almost without +exception, every group we're + +going to talk about is +an abelian group. + +That means that in adding +things up, the + +order doesn't matter. + +So if that were true, then it in +a plus b plus c, that means + +that's the same as c plus +b plus a, or c plus + +a plus b, or whatever. + +All the properties that +you're accustomed to + +from ordinary addition. + +But this is not one of the group +axioms, and, of course, + +there are non-abelian groups. + +The smallest non-abelian group +has size 6, and is the + +permutation group on +three elements. + +So small groups are all -- + +size 5 or less are +all abelian. + +Because that's the only way +we can do the group table. + +All right. + +So that's terminology +at this point. + +It's not part of the axiom. + +But that's the reason that I use +a symbol that looks like a + +plus, is I'm pretty much always +thinking an abelian + +group, and I don't want to +trouble you with thinking + +about non-abelian groups. + +OK. + +Then we have the identity +property. + +There is an identity, which, +in an abelian group, is + +always called -- + +ordinarily called 0. + +In an additive group it's +always called 0. + +So I'll call it 0. + +In more abstract treatments, +it's called 1 or E for -- + +what does E stand for? + +Eigen something. + +There's a 0 in g such that +0 plus a equals -- + +or a plus 0 -- + +is always equal to a. + +The 0 is the null operator on +any element of the group. + +If you add 0 to anything, you +get what you started with. + +Clearly, we have such a thing +in ordinary addition. + +Suppose I was talking in +the real numbers under + +multiplication, is that +a group, you guess? + +It's actually not. + +Suppose I talk about the +non-zero real numbers under + +multiplication. + +Is that a group? + +Yes, and its identity is 1. + +1 as the thing that if you +multiply it by anything, it + +leaves what you started with. + +There's the inverse, which we +don't have in the reals under + +multiplication. + +For all a and g, there exists +something called minus a -- + +or a to the minus 1 in +multiplicative notation -- + +in g such that a plus +minus a equals 0. + +That's an additive inverse. + +So in the real numbers, the +inverse of a is minus a. + +In the integers, the +inverse of a is + +minus a under addition. + +In the non-zero real numbers +under multiplication, every + +non-zero real number does have +a multiplicative inverse, + +which is called 1 over +a, or a minus 1. + +That's why we have +to exclude 0. + +0 does not an inverse. + +So a good example to think +about is r-star, which is + +non-zero reals under ordinary +multiplication, is a group. + +Is it an abelian group? + +Is ab equal to ba? + +Yeah. + +So this is an infinite +abelian group. + +All right. + +OK. + +I want to show that +the axioms lead to + +a permutation property. + +Because this is something +that's going to come + +up again and again. + +One way of saying this is if I +have, if a plus b equals c -- + +suppose I write down that +symbolic equation -- + +then I can solve for any +one of the three + +given the other two. + +How would I do that? + +If I'm given a and b, obviously, +that tells me c + +from the table. + +If I'm given a and c, then a +is equal to c minus b -- + +I'm sorry -- b is equal +to c minus a. + +I should say here, from this +inverse, we're going to write + +b plus minus a in +a simpler form. + +It's just b minus a. + +So the fact that we have an +inverse sort of defines + +another operation, which +we call subtraction, + +which is not abelian. + +Not commutative. + +a minus b is not equal +to b minus a. + +But it's basically implicit +in this that we + +subtract group elements. + +We can cancel group elements. + +If you have a plus c equal +to b plus c, then a + +must be equal to b. + +Because you can subtract +c from both sides. + +All right. + +OK. + +What does this mean that this +gives us a constraint on the + +addition table of a group? + +Suppose I take a four element +group, g, and one of the + +elements is going to be the zero +element, and the other + +let's just call a, b, c. + +0, a, b, c. + +And I have a well-defined +addition table, which + +includes, in here, only +a 0, a, b, c. + +From the property of the +identity, I can fill in some + +of these things. + +And now what freedom do I have +to fill in the rest? + +How many group tables are +there of size four? + +Well, the main point that I want +to make with permutation + +property is that every row and +every column has to be a + +permutation of the four +elements 0, a, b, c. + +Why is that? + +Suppose I had another a +in this column here. + +Then I would have a plus 0 is +equal to a, and also a plus c + +is equal to a. + +But that would imply that c +equals 0, which it isn't. + +All right. + +So in order to be able to solve +this equation, this has + +to be something different +from a, and likewise. + +Since I have, in this case, a +finite group, I basically just + +have to write the group elements +down here again in + +some order. + +It tuRns out that for four +elements, there are exactly + +two ways of doing that, +generically. + +One is sort of the +cyclic group. + +I'm sorry -- + +a, b, c, 0, a, c, 0, a, b. + +That's one way of filling out +the table such that each row + +is a permutation +of 0, a, b, c. + +Each column is a permutation +of 0, a, b, c. + +So that's a legitimate +group table. + +Let me just, for your interest, +show you that that's + +not the only one. + +We could also do 0, a, +b, c, 0, a, b, c. + +If I write 0 here, then +I've got to write + +c there and b there. + +Got to write c here +and b there. + +And then down here, the only +choice I have is this. + +This is called the cyclic +group of four elements. + +This is called the +Klein four group. + +And this is all there is. + +Both of them tuRn out to be +abelian if you check it out. + +And basically, this permutation +property restricts + +these to be the possible groups +of size four, abelian + +or non-abelian, just to +satisfy the axiom. + +I actually prove in the notes +that if you replace axioms a + +and b with the permutation +property, you get another + +equivalent set of axioms +for a group. + +So the permutation of properties +is very basic. + +All you need is -- + +for a set and a binary operation +to form a group, all + +you need is identity, +associativity, and the + +permutation property for +the group table, + +the addition table. + +Simple proof of that +in the notes. + +But this observation +is going to be + +important as we go forward. + +It's a fundamental thing +we're going to use. + +So you see a group can't +just be anything. + +It already has very definite +restrictions on it. + +All right. + +Anything else I want +to say right here? + +OK, subtraction, cancellation. + +OK, I guess we can go into +the next property, + +which is cyclic groups. + +And I'm only going to talk about +finite cyclic groups, or + +finite groups in general. + +Now, a cyclic group +is probably the + +simplest kind of group. + +Let me first put up the +canonical cyclic group, which + +is the integers mod-n, which +means the set of residues + +mod-n and the mod-n addition +operation. + +Which is written just as Zn -- + +there are various notations +for it. + +But this, of course, we'll +just write it as Zn. + +The integers mod-n. + +Does this form a group? + +Let's check the axioms. + +Certainly, let's take +the original axioms. + +So the Rn is closed under +addition mod-n. + +If we add two elements, we're +going to get another element. + +The mod-n addition operation +is associative. + +In fact, it's abelian. + +a plus b plus c is b plus c plus +a -- it doesn't matter + +what order, from the +same property + +for ordinary addition. + +Is there an identity in here? + +Yes. + +The 0 is one of the elements +here and acts as the identity. + +0 plus anything mod-n is equal +to the same thing mod-n. + +And is there an inverse? + +OK. + +Let's explicitly write out Rn +as 0, 1 up to n minus 1. + +And then I claim that if I take +any of these i, then n + +minus i is its inverse. + +n minus i is in the right +range if not zero. + +The inverse of 0 is 0. + +The inverse of i between 1 and +n minus 1 is going to be n + +minus i because if I add +i to n minus i -- + +is equal to n, take mod-n, +that's equal to 0. + +So every element has the +additive inverse. + +And so the group table has a +very boring form, which does + +satisfy the permutation +property. + +If I take Z5, for instance. + +0,1,2,3,4. + +0 plus anything looks +like that. + +1 times anything is +just 1,2,3,4 and 1 + +plus 4 is 0 mod 5. + +2,3,4,0,1, and so forth. + +3, 4, 0, 1, 2, 4, 0, 1, 2, 3. + +Each row or column is just a +cyclic shift to the previous + +row or column. + +Just fill it out. + +And does it satisfy the +permutation property? + +Yes, it does. + +This one here, for instance, you +can recognize as a cyclic + +group table. + +And so, apart from relabeling, +this is the group table of Z4. + +Or we take a, b, c +equal to 1, 2, 3. + +If two groups have the same +group table up to relabelling, + +they're said to be isomorphic. + +OK? + +That's an important +concept in math. + +And all it means is the two +groups act the same, except + +that we've changed the names +of the group elements. + +OK. + +So what I'm going to show +is that all cyclic -- + +this group is sort of cyclic +because, as you see in the + +notes, we can think of adding +1 as just being + +cycling around a circle. + +In this case, with +5 points on it. + +And adding 2 is going two +steps around the circle. + +And the elements on the +circle are the group + +elements 0, 1, 2, 3, 4. + +And then we get to 5. + +We identify that with 0. + +So we close the loop. + +One we identify with 6. + +This with 7. + +This with 8. + +Up to as many as you like. + +So that's the intuition +why these are + +called cyclic groups. + +The addition operation cycles +rather than being on a line, + +as it would be with the ordinary +integers, where we go + +infinitely in either +direction. + +So the formal definition of a +cyclic group is that g has a + +single generator. + +Call it a little g. + +And -- am I running over? + +Close to. + +Is that really right? + +I only have five minutes left. + +We're not going to go at +the speed I had hoped. + +g is -- + +what does that mean? + +If we know that g contains g, +and this is never going to be + +equal to 0, then we know that +g contains two elements at + +least: 0 and g. + +And by the group axioms, g +contains g, g plus g, g + +plus g plus g -- + +we can keep adding them. + +I'm going to call these the +integer multiples of g. + +So this will be 1g, 2g, 3g. + +That's what I mean when +I write an integer + +in front of g -- + +I mean g plus itself, the +integer number of times. + +And all those things, by the +group properties, have to be + +in the group. + +All right? + +Again, restrict this +to finite. + +It's a finite cyclic group. + +Then at some point, +I have to -- + +this is all the elements +of the group. + +So at some point, I have +to come along and + +say that ng is 0. + +If just by -- + +when I say generator, the +set generated by g is + +just 1g, 2g, 3g. + +And that's got to be all the +elements of the group, so n + +times g has got to be 0. + +And that means, without putting +too fine a point on + +it, that if n were 5, for +instance, the group has to + +consist of 0g, 1g, 2g, 3g, 4g, +and then 5g is equal to 0. + +So we call this 0g or 5g. + +And furthermore, the addition +table of the group, we can, + +you know -- + +however, if we add 2 g's to 3 +g's, we're going to 5 g's, + +which is 0. + +All right? + +So 2g plus 3g has got to +be 5 g's, which is 0g. + +So this is what the addition +table of the + +group has to look like. + +It's exactly the same, except +we just make a one-to-one + +correspondence like that. + +So the conclusion is a +finite cyclic group + +with n elements -- + +I'll write the size of g by this +absolute value thing -- + +is isomorphic to the +integers mod-n -- + +this canonical cyclic group +that we started with -- + +must be isomorphic to Zn with +the isomorphism being given by + +the one-to-one correspondence. + +i_g in the group corresponds +to simply i in Zn, or 0 is + +less than or equal to +i is less than or + +equal to n minus 1. + +The addition rule is +exactly the same. + +OK, so this is a pretty +sweeping conclusion. + +It says that really the only +finite cyclic group up to + +relabeling is Zn. + +OK, so if you understand Zn, +you understand all finite + +cyclic groups. + +Just in a general group, we're +going to have some element + +which basically represents 1, +called g, and its integer + +multiples, which represent +2, 3, 4, and so forth. + +But we can operate with +a group just as + +though it was Zn. + +So it's easy to understand +finite cyclic groups. + +They all just look like this. + +Question? + +Yeah. + +AUDIENCE: Is the generator +unique? + +PROFESSOR: No, it's not. + +No, it's not. + +Next time we'll start +to talk about + +subgroups of Zn, for instance. + +In the set of Z5 -- + +well, let me take this. + +All right. + +In Z5 -- + +let me not even do that. + +In Z5, 1 is the generator, but +because 5 is a prime, 2 is a + +generator, too. + +All right? + +Another way of writing. + +Let's take a generator +equals 2 in Z5. + +Then g equals 2, 2g equals 4. + +3g equals 6, equals 1 mod-5. + +4g equals 3. + +And 5g, of course, equals +5, which equals zero. + +So 2 is also a generator. + +And, in fact, 3 and 4 +are also generators. + +There are four generators. + +This is getting us right +into the number theory. + +OK. + +So no, g does not +have to be 1. + +g is just something that if +you take all its integer + +multiples, you generate +the group. + +OK, I guess we stop there, and +we'll resume next time. \ No newline at end of file diff --git a/dz2vRqxf0HI.txt b/dz2vRqxf0HI.txt new file mode 100644 index 0000000000000000000000000000000000000000..cb39be38a1decb234cdf2d8a48e609af85453e12 --- /dev/null +++ b/dz2vRqxf0HI.txt @@ -0,0 +1,315 @@ +align:start position:0% + +It turns out that much of what accounts + + align:start position:0% +It turns out that much of what accounts + + + align:start position:0% +It turns out that much of what accounts +for success in life is not skill or hard + + align:start position:0% +for success in life is not skill or hard + + + align:start position:0% +for success in life is not skill or hard +work but luck. + + align:start position:0% +work but luck. + + + align:start position:0% +work but luck. +And in that case, + + align:start position:0% +And in that case, + + + align:start position:0% +And in that case, +it's not true that rich people are rich + + align:start position:0% +it's not true that rich people are rich + + + align:start position:0% +it's not true that rich people are rich +because they deserve it or because they + + align:start position:0% +because they deserve it or because they + + + align:start position:0% +because they deserve it or because they +have skills or worked hard or they're + + align:start position:0% +have skills or worked hard or they're + + + align:start position:0% +have skills or worked hard or they're +just lucky. And why do we necessarily + + align:start position:0% +just lucky. And why do we necessarily + + + align:start position:0% +just lucky. And why do we necessarily +want to reward luck? Indeed, can't we + + align:start position:0% +want to reward luck? Indeed, can't we + + + align:start position:0% +want to reward luck? Indeed, can't we +think of redistribution as kind of luck + + align:start position:0% +think of redistribution as kind of luck + + + align:start position:0% +think of redistribution as kind of luck +insurance? + + align:start position:0% +insurance? + + + align:start position:0% +insurance? +Imagine a world where a random event's + + align:start position:0% +Imagine a world where a random event's + + + align:start position:0% +Imagine a world where a random event's +going to happen to you. You get hit by a + + align:start position:0% +going to happen to you. You get hit by a + + + align:start position:0% +going to happen to you. You get hit by a +car. We talked about why we want + + align:start position:0% +car. We talked about why we want + + + align:start position:0% +car. We talked about why we want +insurance, right? Want insurance to make + + align:start position:0% +insurance, right? Want insurance to make + + + align:start position:0% +insurance, right? Want insurance to make +sure if we get hit by the car, don't get + + align:start position:0% +sure if we get hit by the car, don't get + + + align:start position:0% +sure if we get hit by the car, don't get +hit by the car, we're in the same off. + + align:start position:0% +hit by the car, we're in the same off. + + + align:start position:0% +hit by the car, we're in the same off. +Well, same thing. Rolls talked about + + align:start position:0% +Well, same thing. Rolls talked about + + + align:start position:0% +Well, same thing. Rolls talked about +behind the veil of ignorance. Imagine + + align:start position:0% +behind the veil of ignorance. Imagine + + + align:start position:0% +behind the veil of ignorance. Imagine +before you're born, you don't know if + + align:start position:0% +before you're born, you don't know if + + + align:start position:0% +before you're born, you don't know if +you were rich or poor. You would choose + + align:start position:0% +you were rich or poor. You would choose + + + align:start position:0% +you were rich or poor. You would choose +a system which would ensure you against + + align:start position:0% +a system which would ensure you against + + + align:start position:0% +a system which would ensure you against +being poor. + + align:start position:0% +being poor. + + + align:start position:0% +being poor. +And that system which would involve + + align:start position:0% +And that system which would involve + + + align:start position:0% +And that system which would involve +transfers. + + align:start position:0% +transfers. + + + align:start position:0% +transfers. +So if much of success is due to luck, + + align:start position:0% +So if much of success is due to luck, + + + align:start position:0% +So if much of success is due to luck, +we're going to want a system that shoots + + align:start position:0% +we're going to want a system that shoots + + + align:start position:0% +we're going to want a system that shoots +the rich to the poor because the rich + + align:start position:0% +the rich to the poor because the rich + + + align:start position:0% +the rich to the poor because the rich +got lucky, the poor didn't. That's + + align:start position:0% +got lucky, the poor didn't. That's + + + align:start position:0% +got lucky, the poor didn't. That's +uncertainty we want to ensure against. + + align:start position:0% +uncertainty we want to ensure against. + + + align:start position:0% +uncertainty we want to ensure against. +Okay. Fascinating fact. If you if you + + align:start position:0% +Okay. Fascinating fact. If you if you + + + align:start position:0% +Okay. Fascinating fact. If you if you +interview people around the world and + + align:start position:0% +interview people around the world and + + + align:start position:0% +interview people around the world and +ask them + + align:start position:0% +ask them + + + align:start position:0% +ask them +is success mostly due to hard work or to + + align:start position:0% +is success mostly due to hard work or to + + + align:start position:0% +is success mostly due to hard work or to +luck. In the US people say hard work. In + + align:start position:0% +luck. In the US people say hard work. In + + + align:start position:0% +luck. In the US people say hard work. In +Europe people say luck. In Europe they + + align:start position:0% +Europe people say luck. In Europe they + + + align:start position:0% +Europe people say luck. In Europe they +have much higher redistribution than we + + align:start position:0% +have much higher redistribution than we + + + align:start position:0% +have much higher redistribution than we +do in the US. + + align:start position:0% +do in the US. + + + align:start position:0% +do in the US. +because they have a view that much more + + align:start position:0% +because they have a view that much more + + + align:start position:0% +because they have a view that much more +success comes from luck. \ No newline at end of file diff --git a/dzGar1Jnf90.txt b/dzGar1Jnf90.txt new file mode 100644 index 0000000000000000000000000000000000000000..f6d27192b03f0799d5dab1fdc9a8c1afc887fc7d --- /dev/null +++ b/dzGar1Jnf90.txt @@ -0,0 +1,10443 @@ +align:start position:0% + +the following content is provided by mit + + align:start position:0% +the following content is provided by mit + + + align:start position:0% +the following content is provided by mit +opencourseware under a creative commons + + align:start position:0% +opencourseware under a creative commons + + + align:start position:0% +opencourseware under a creative commons +license + + align:start position:0% +license + + + align:start position:0% +license +additional information about our license + + align:start position:0% +additional information about our license + + + align:start position:0% +additional information about our license +and mit opencourseware in general is + + align:start position:0% +and mit opencourseware in general is + + + align:start position:0% +and mit opencourseware in general is +available at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +as promised here's uh we're going into + + align:start position:0% +as promised here's uh we're going into + + + align:start position:0% +as promised here's uh we're going into +flux balance analysis + + align:start position:0% +flux balance analysis + + + align:start position:0% +flux balance analysis +the simplifications here are even + + align:start position:0% +the simplifications here are even + + + align:start position:0% +the simplifications here are even +greater than the ones that we + + align:start position:0% +greater than the ones that we + + + align:start position:0% +greater than the ones that we +have been making so far but hopefully + + align:start position:0% +have been making so far but hopefully + + + align:start position:0% +have been making so far but hopefully +you will see some benefit + + align:start position:0% + + + + align:start position:0% + +we're here uh + + align:start position:0% +we're here uh + + + align:start position:0% +we're here uh +assuming that time constant metabolic + + align:start position:0% +assuming that time constant metabolic + + + align:start position:0% +assuming that time constant metabolic +reactions are very fast compared to cell + + align:start position:0% +reactions are very fast compared to cell + + + align:start position:0% +reactions are very fast compared to cell +growth + + align:start position:0% +growth + + + align:start position:0% +growth +cell growth you know we've seen the time + + align:start position:0% +cell growth you know we've seen the time + + + align:start position:0% +cell growth you know we've seen the time +constants are in the order of seconds or + + align:start position:0% +constants are in the order of seconds or + + + align:start position:0% +constants are in the order of seconds or +or sometimes less while growth might be + + align:start position:0% +or sometimes less while growth might be + + + align:start position:0% +or sometimes less while growth might be +on the order of hours + + align:start position:0% + + + + align:start position:0% + +even though we've seen interesting + + align:start position:0% +even though we've seen interesting + + + align:start position:0% +even though we've seen interesting +dynamics that can occur those phase + + align:start position:0% +dynamics that can occur those phase + + + align:start position:0% +dynamics that can occur those phase +diagrams that we had in the ordinary + + align:start position:0% +diagrams that we had in the ordinary + + + align:start position:0% +diagrams that we had in the ordinary +differential equations + + align:start position:0% + + + + align:start position:0% + +there are also many + + align:start position:0% +there are also many + + + align:start position:0% +there are also many +it's very typical for a cell to be in + + align:start position:0% +it's very typical for a cell to be in + + + align:start position:0% +it's very typical for a cell to be in +fairly stable conditions you know + + align:start position:0% +fairly stable conditions you know + + + align:start position:0% +fairly stable conditions you know +there'll be a transition time and then + + align:start position:0% +there'll be a transition time and then + + + align:start position:0% +there'll be a transition time and then +they'll be stable again and that will be + + align:start position:0% +they'll be stable again and that will be + + + align:start position:0% +they'll be stable again and that will be +the steady-state assumption so we'll say + + align:start position:0% +the steady-state assumption so we'll say + + + align:start position:0% +the steady-state assumption so we'll say +there's no net accumulation of + + align:start position:0% +there's no net accumulation of + + + align:start position:0% +there's no net accumulation of +metabolites + + align:start position:0% + + + + align:start position:0% + +so even though there may be fluxes + + align:start position:0% +so even though there may be fluxes + + + align:start position:0% +so even though there may be fluxes +into and out of every metabolite the net + + align:start position:0% +into and out of every metabolite the net + + + align:start position:0% +into and out of every metabolite the net +change is zero and so that means this + + align:start position:0% +change is zero and so that means this + + + align:start position:0% +change is zero and so that means this +this equation we've seen a few times the + + align:start position:0% +this equation we've seen a few times the + + + align:start position:0% +this equation we've seen a few times the +change in x with respect to time + + align:start position:0% +change in x with respect to time + + + align:start position:0% +change in x with respect to time +is zero and that means the + + align:start position:0% +is zero and that means the + + + align:start position:0% +is zero and that means the +stoichiometric matrix times of times the + + align:start position:0% +stoichiometric matrix times of times the + + + align:start position:0% +stoichiometric matrix times of times the +flux rate for that + + align:start position:0% +flux rate for that + + + align:start position:0% +flux rate for that +for all relevant reactions you can think + + align:start position:0% +for all relevant reactions you can think + + + align:start position:0% +for all relevant reactions you can think +of as a matrix representation sum of all + + align:start position:0% +of as a matrix representation sum of all + + + align:start position:0% +of as a matrix representation sum of all +inputs and outputs that particular x + + align:start position:0% +inputs and outputs that particular x + + + align:start position:0% +inputs and outputs that particular x +position + + align:start position:0% +position + + + align:start position:0% +position +minus the transport vector which is kept + + align:start position:0% +minus the transport vector which is kept + + + align:start position:0% +minus the transport vector which is kept +separately + + align:start position:0% +separately + + + align:start position:0% +separately +is all zero + + align:start position:0% +is all zero + + + align:start position:0% +is all zero +so what does that mean that means the + + align:start position:0% +so what does that mean that means the + + + align:start position:0% +so what does that mean that means the +stoichiometric matrix times the internal + + align:start position:0% +stoichiometric matrix times the internal + + + align:start position:0% +stoichiometric matrix times the internal +fluxes is equal to transport across the + + align:start position:0% +fluxes is equal to transport across the + + + align:start position:0% +fluxes is equal to transport across the +membrane + + align:start position:0% +membrane + + + align:start position:0% +membrane +and this is something we'll i'll show + + align:start position:0% +and this is something we'll i'll show + + + align:start position:0% +and this is something we'll i'll show +you we're going to do this + + align:start position:0% +you we're going to do this + + + align:start position:0% +you we're going to do this +in two steps first we're going to solve + + align:start position:0% +in two steps first we're going to solve + + + align:start position:0% +in two steps first we're going to solve +for that as if there was an exact + + align:start position:0% +for that as if there was an exact + + + align:start position:0% +for that as if there was an exact +set of equations just the right number + + align:start position:0% +set of equations just the right number + + + align:start position:0% +set of equations just the right number +of equations just the right number of + + align:start position:0% +of equations just the right number of + + + align:start position:0% +of equations just the right number of +unknowns so you can actually get a + + align:start position:0% +unknowns so you can actually get a + + + align:start position:0% +unknowns so you can actually get a +solve for the unknown fluxes and then + + align:start position:0% +solve for the unknown fluxes and then + + + align:start position:0% +solve for the unknown fluxes and then +we'll work through it where it's + + align:start position:0% +we'll work through it where it's + + + align:start position:0% +we'll work through it where it's +actually under determined but there are + + align:start position:0% +actually under determined but there are + + + align:start position:0% +actually under determined but there are +inequality constraints first let's take + + align:start position:0% +inequality constraints first let's take + + + align:start position:0% +inequality constraints first let's take +the exact case + + align:start position:0% +the exact case + + + align:start position:0% +the exact case +because it so stoichiometry is known + + align:start position:0% +because it so stoichiometry is known + + + align:start position:0% +because it so stoichiometry is known +that's the s these are the zeros and + + align:start position:0% +that's the s these are the zeros and + + + align:start position:0% +that's the s these are the zeros and +ones minus ones twos and so on + + align:start position:0% +ones minus ones twos and so on + + + align:start position:0% +ones minus ones twos and so on +uh the uptake rates + + align:start position:0% +uh the uptake rates + + + align:start position:0% +uh the uptake rates +can be known in the sense that you can + + align:start position:0% +can be known in the sense that you can + + + align:start position:0% +can be known in the sense that you can +regulate the amount of + + align:start position:0% + + + + align:start position:0% + +input and + + align:start position:0% +input and + + + align:start position:0% +input and +output by the the rate at which you + + align:start position:0% +output by the the rate at which you + + + align:start position:0% +output by the the rate at which you +remove + + align:start position:0% +remove + + + align:start position:0% +remove +substrates and add them + + align:start position:0% +substrates and add them + + + align:start position:0% +substrates and add them +and the metabolic fluxes are what you + + align:start position:0% +and the metabolic fluxes are what you + + + align:start position:0% +and the metabolic fluxes are what you +actually want this is in contrast to the + + align:start position:0% +actually want this is in contrast to the + + + align:start position:0% +actually want this is in contrast to the +red blood cell or other + + align:start position:0% +red blood cell or other + + + align:start position:0% +red blood cell or other +ordinary difference equation cases we + + align:start position:0% +ordinary difference equation cases we + + + align:start position:0% +ordinary difference equation cases we +were talking about where the rate + + align:start position:0% +were talking about where the rate + + + align:start position:0% +were talking about where the rate +equations were known but we were we're + + align:start position:0% +equations were known but we were we're + + + align:start position:0% +equations were known but we were we're +looking for concentrations here we're + + align:start position:0% +looking for concentrations here we're + + + align:start position:0% +looking for concentrations here we're +less concerned about concentrations and + + align:start position:0% +less concerned about concentrations and + + + align:start position:0% +less concerned about concentrations and +we want to learn what it might be the + + align:start position:0% +we want to learn what it might be the + + + align:start position:0% +we want to learn what it might be the +the fluxes and later what might be the + + align:start position:0% +the fluxes and later what might be the + + + align:start position:0% +the fluxes and later what might be the +optimal fluxes + + align:start position:0% +optimal fluxes + + + align:start position:0% +optimal fluxes +so slide 42 + + align:start position:0% +so slide 42 + + + align:start position:0% +so slide 42 +let's say + + align:start position:0% +let's say + + + align:start position:0% +let's say +that we + + align:start position:0% + + + + align:start position:0% + +as a way nomenclature we focus on + + align:start position:0% +as a way nomenclature we focus on + + + align:start position:0% +as a way nomenclature we focus on +positive fluxes if we want to go the + + align:start position:0% +positive fluxes if we want to go the + + + align:start position:0% +positive fluxes if we want to go the +opposite direction we'll make that a + + align:start position:0% +opposite direction we'll make that a + + + align:start position:0% +opposite direction we'll make that a +another uh reverse flux + + align:start position:0% +another uh reverse flux + + + align:start position:0% +another uh reverse flux +separate flux so focusing on positive + + align:start position:0% +separate flux so focusing on positive + + + align:start position:0% +separate flux so focusing on positive +fluxes + + align:start position:0% +fluxes + + + align:start position:0% +fluxes +we know we might know the flux level in + + align:start position:0% +we know we might know the flux level in + + + align:start position:0% +we know we might know the flux level in +certain reactions that will help us have + + align:start position:0% +certain reactions that will help us have + + + align:start position:0% +certain reactions that will help us have +this the equations + + align:start position:0% +this the equations + + + align:start position:0% +this the equations +appropriately constrained + + align:start position:0% +appropriately constrained + + + align:start position:0% +appropriately constrained +we can control update rates + + align:start position:0% +we can control update rates + + + align:start position:0% +we can control update rates +we have we can have maximum values for + + align:start position:0% +we have we can have maximum values for + + + align:start position:0% +we have we can have maximum values for +uptake and internal fluxes + + align:start position:0% +uptake and internal fluxes + + + align:start position:0% +uptake and internal fluxes +so here's an example let's walk through + + align:start position:0% +so here's an example let's walk through + + + align:start position:0% +so here's an example let's walk through +it it's nice to have a couple of + + align:start position:0% +it it's nice to have a couple of + + + align:start position:0% +it it's nice to have a couple of +one or two examples where we walk + + align:start position:0% +one or two examples where we walk + + + align:start position:0% +one or two examples where we walk +through in a + + align:start position:0% +through in a + + + align:start position:0% +through in a +in a given class so here we're going to + + align:start position:0% +in a given class so here we're going to + + + align:start position:0% +in a given class so here we're going to +have + + align:start position:0% +have + + + align:start position:0% +have +an input + + align:start position:0% +an input + + + align:start position:0% +an input +molecule a it's transported across the + + align:start position:0% +molecule a it's transported across the + + + align:start position:0% +molecule a it's transported across the +membrane at a rate r sub a + + align:start position:0% +membrane at a rate r sub a + + + align:start position:0% +membrane at a rate r sub a +it then has essentially a decision fork + + align:start position:0% +it then has essentially a decision fork + + + align:start position:0% +it then has essentially a decision fork +here some fraction of the a is going to + + align:start position:0% +here some fraction of the a is going to + + + align:start position:0% +here some fraction of the a is going to +go through the x1 reaction and some + + align:start position:0% +go through the x1 reaction and some + + + align:start position:0% +go through the x1 reaction and some +fractions of the x2 the amount that goes + + align:start position:0% +fractions of the x2 the amount that goes + + + align:start position:0% +fractions of the x2 the amount that goes +through x1 and x2 is what we is what we + + align:start position:0% +through x1 and x2 is what we is what we + + + align:start position:0% +through x1 and x2 is what we is what we +want to know + + align:start position:0% +want to know + + + align:start position:0% +want to know +we are going to be given uh + + align:start position:0% +we are going to be given uh + + + align:start position:0% +we are going to be given uh +the we're going to essentially clamp + + align:start position:0% +the we're going to essentially clamp + + + align:start position:0% +the we're going to essentially clamp +control the rate it goes across the + + align:start position:0% +control the rate it goes across the + + + align:start position:0% +control the rate it goes across the +membrane r a so that's going to be a + + align:start position:0% +membrane r a so that's going to be a + + + align:start position:0% +membrane r a so that's going to be a +given you can see the constraint here r + + align:start position:0% +given you can see the constraint here r + + + align:start position:0% +given you can see the constraint here r +a is going to be 3 + + align:start position:0% +a is going to be 3 + + + align:start position:0% +a is going to be 3 +and we're going to uh also know the rate + + align:start position:0% +and we're going to uh also know the rate + + + align:start position:0% +and we're going to uh also know the rate +at which b is removed and that's going + + align:start position:0% +at which b is removed and that's going + + + align:start position:0% +at which b is removed and that's going +to be kept constant at 1. so we're going + + align:start position:0% +to be kept constant at 1. so we're going + + + align:start position:0% +to be kept constant at 1. so we're going +to solve for the two internal fluxes x + + align:start position:0% +to solve for the two internal fluxes x + + + align:start position:0% +to solve for the two internal fluxes x +and maybe this external uh transport + + align:start position:0% +and maybe this external uh transport + + + align:start position:0% +and maybe this external uh transport +flux + + align:start position:0% +flux + + + align:start position:0% +flux +are c + + align:start position:0% +are c + + + align:start position:0% +are c +now we know there's going to be + + align:start position:0% +now we know there's going to be + + + align:start position:0% +now we know there's going to be +conservation of mass so we can start + + align:start position:0% +conservation of mass so we can start + + + align:start position:0% +conservation of mass so we can start +setting up the flux balances in the + + align:start position:0% +setting up the flux balances in the + + + align:start position:0% +setting up the flux balances in the +upper + + align:start position:0% +upper + + + align:start position:0% +upper +uh + + align:start position:0% +uh + + + align:start position:0% +uh +right-hand corner here of slide 43. + + align:start position:0% +right-hand corner here of slide 43. + + + align:start position:0% +right-hand corner here of slide 43. +take a look at a a is created + + align:start position:0% +take a look at a a is created + + + align:start position:0% +take a look at a a is created +essentially the intracellular + + align:start position:0% +essentially the intracellular + + + align:start position:0% +essentially the intracellular +concentration of a is dependent uh on r + + align:start position:0% +concentration of a is dependent uh on r + + + align:start position:0% +concentration of a is dependent uh on r +sub a and then it splits into x1 and x2 + + align:start position:0% +sub a and then it splits into x1 and x2 + + + align:start position:0% +sub a and then it splits into x1 and x2 +so you know that r r sub a + + align:start position:0% +so you know that r r sub a + + + align:start position:0% +so you know that r r sub a +minus x1 minus x2 is going to be zero + + align:start position:0% +minus x1 minus x2 is going to be zero + + + align:start position:0% +minus x1 minus x2 is going to be zero +they're going to cancel out because a by + + align:start position:0% +they're going to cancel out because a by + + + align:start position:0% +they're going to cancel out because a by +steady state assumption is going to be + + align:start position:0% +steady state assumption is going to be + + + align:start position:0% +steady state assumption is going to be +constant even though the fluxes are not + + align:start position:0% +constant even though the fluxes are not + + + align:start position:0% +constant even though the fluxes are not +zero + + align:start position:0% +zero + + + align:start position:0% +zero +uh their sum is and for b a similar + + align:start position:0% +uh their sum is and for b a similar + + + align:start position:0% +uh their sum is and for b a similar +argument we made x one + + align:start position:0% +argument we made x one + + + align:start position:0% +argument we made x one +which creates b has to uh sum with r sub + + align:start position:0% +which creates b has to uh sum with r sub + + + align:start position:0% +which creates b has to uh sum with r sub +b to zero and the same thing for c all + + align:start position:0% +b to zero and the same thing for c all + + + align:start position:0% +b to zero and the same thing for c all +the inputs have to equal the outputs + + align:start position:0% +the inputs have to equal the outputs + + + align:start position:0% +the inputs have to equal the outputs +we have these two constraints where + + align:start position:0% +we have these two constraints where + + + align:start position:0% +we have these two constraints where +we've just said we're going to + + align:start position:0% +we've just said we're going to + + + align:start position:0% +we've just said we're going to +clamp experimentally the amount of a + + align:start position:0% +clamp experimentally the amount of a + + + align:start position:0% +clamp experimentally the amount of a +going in and the amount of b coming out + + align:start position:0% +going in and the amount of b coming out + + + align:start position:0% +going in and the amount of b coming out +and we want to solve for the other three + + align:start position:0% +and we want to solve for the other three + + + align:start position:0% +and we want to solve for the other three +kinetic parameters so we have three + + align:start position:0% +kinetic parameters so we have three + + + align:start position:0% +kinetic parameters so we have three +equations and three unknowns + + align:start position:0% +equations and three unknowns + + + align:start position:0% +equations and three unknowns +the unknowns there's two internal fluxes + + align:start position:0% +the unknowns there's two internal fluxes + + + align:start position:0% +the unknowns there's two internal fluxes +and the r sub c + + align:start position:0% +and the r sub c + + + align:start position:0% +and the r sub c +and so another way of stating this + + align:start position:0% +and so another way of stating this + + + align:start position:0% +and so another way of stating this +equation x one plus x two is equal to + + align:start position:0% +equation x one plus x two is equal to + + + align:start position:0% +equation x one plus x two is equal to +three x because we know three going in + + align:start position:0% +three x because we know three going in + + + align:start position:0% +three x because we know three going in +has to equal x one x two by flux balance + + align:start position:0% +has to equal x one x two by flux balance + + + align:start position:0% +has to equal x one x two by flux balance +this is essentially the flux balance for + + align:start position:0% +this is essentially the flux balance for + + + align:start position:0% +this is essentially the flux balance for +a can be summarized as x1 plus x2 equals + + align:start position:0% +a can be summarized as x1 plus x2 equals + + + align:start position:0% +a can be summarized as x1 plus x2 equals +3 or in matrix formation it's the top + + align:start position:0% +3 or in matrix formation it's the top + + + align:start position:0% +3 or in matrix formation it's the top +uh row here 1 1 0 + + align:start position:0% +uh row here 1 1 0 + + + align:start position:0% +uh row here 1 1 0 +right + + align:start position:0% +right + + + align:start position:0% +right +it time + + align:start position:0% +it time + + + align:start position:0% +it time +is + + align:start position:0% +is + + + align:start position:0% +is +and the the 3 is in the + + align:start position:0% +and the the 3 is in the + + + align:start position:0% +and the the 3 is in the +transport + + align:start position:0% +transport + + + align:start position:0% +transport +column vector at the far right hand side + + align:start position:0% +column vector at the far right hand side + + + align:start position:0% +column vector at the far right hand side +and similarly you fill up the rest of + + align:start position:0% +and similarly you fill up the rest of + + + align:start position:0% +and similarly you fill up the rest of +the stoichiometric matrix with zeros and + + align:start position:0% +the stoichiometric matrix with zeros and + + + align:start position:0% +the stoichiometric matrix with zeros and +ones and twos and minus ones and the the + + align:start position:0% +ones and twos and minus ones and the the + + + align:start position:0% +ones and twos and minus ones and the the +transport the flux vectors are three one + + align:start position:0% +transport the flux vectors are three one + + + align:start position:0% +transport the flux vectors are three one +zero + + align:start position:0% +zero + + + align:start position:0% +zero +um + + align:start position:0% +um + + + align:start position:0% +um +for the constraints that we have + + align:start position:0% +for the constraints that we have + + + align:start position:0% +for the constraints that we have +and they solve for this three equations + + align:start position:0% +and they solve for this three equations + + + align:start position:0% +and they solve for this three equations +three unknowns + + align:start position:0% +three unknowns + + + align:start position:0% +three unknowns +you can solve it uh by standard linear + + align:start position:0% +you can solve it uh by standard linear + + + align:start position:0% +you can solve it uh by standard linear +algebra tricks + + align:start position:0% +algebra tricks + + + align:start position:0% +algebra tricks +um just + + align:start position:0% + + + + align:start position:0% + +s times v equals b so v is equal to + + align:start position:0% +s times v equals b so v is equal to + + + align:start position:0% +s times v equals b so v is equal to +inverse matrix s times b + + align:start position:0% +inverse matrix s times b + + + align:start position:0% +inverse matrix s times b +the matrix we had in the previous slide + + align:start position:0% +the matrix we had in the previous slide + + + align:start position:0% +the matrix we had in the previous slide +which was first row was 1 1 0. now + + align:start position:0% +which was first row was 1 1 0. now + + + align:start position:0% +which was first row was 1 1 0. now +when you do the inverse matrix you get + + align:start position:0% +when you do the inverse matrix you get + + + align:start position:0% +when you do the inverse matrix you get +this upper right hand portion and you + + align:start position:0% +this upper right hand portion and you + + + align:start position:0% +this upper right hand portion and you +multiply it out and you get the column + + align:start position:0% +multiply it out and you get the column + + + align:start position:0% +multiply it out and you get the column +vector solution which is 1 2 four for x1 + + align:start position:0% +vector solution which is 1 2 four for x1 + + + align:start position:0% +vector solution which is 1 2 four for x1 +x2 and rc respectively now they're + + align:start position:0% +x2 and rc respectively now they're + + + align:start position:0% +x2 and rc respectively now they're +plugged into this diagram + + align:start position:0% +plugged into this diagram + + + align:start position:0% +plugged into this diagram +and you can see that the whole masses + + align:start position:0% +and you can see that the whole masses + + + align:start position:0% +and you can see that the whole masses +balance out + + align:start position:0% +balance out + + + align:start position:0% +balance out +three is equal to one plus two + + align:start position:0% +three is equal to one plus two + + + align:start position:0% +three is equal to one plus two +2 times c + + align:start position:0% +2 times c + + + align:start position:0% +2 times c +2 times 2 is equal to 4. + + align:start position:0% +2 times 2 is equal to 4. + + + align:start position:0% +2 times 2 is equal to 4. +okay + + align:start position:0% + + + + align:start position:0% + +so that's an example where it's heavily + + align:start position:0% +so that's an example where it's heavily + + + align:start position:0% +so that's an example where it's heavily +constrained and so we can solve it + + align:start position:0% +constrained and so we can solve it + + + align:start position:0% +constrained and so we can solve it +exactly + + align:start position:0% +exactly + + + align:start position:0% +exactly +however + + align:start position:0% +however + + + align:start position:0% +however +very often there are not + + align:start position:0% + + + + align:start position:0% + +enough + + align:start position:0% +enough + + + align:start position:0% +enough +measurements that have been made we + + align:start position:0% +measurements that have been made we + + + align:start position:0% +measurements that have been made we +can't clamp all these fluxes and there + + align:start position:0% +can't clamp all these fluxes and there + + + align:start position:0% +can't clamp all these fluxes and there +are many more internal fluxes than + + align:start position:0% +are many more internal fluxes than + + + align:start position:0% +are many more internal fluxes than +external and so we have an + + align:start position:0% +external and so we have an + + + align:start position:0% +external and so we have an +underdetermined system + + align:start position:0% +underdetermined system + + + align:start position:0% +underdetermined system +what is a good system biologist to do at + + align:start position:0% +what is a good system biologist to do at + + + align:start position:0% +what is a good system biologist to do at +this point + + align:start position:0% +this point + + + align:start position:0% +this point +well the formal solution is it's no + + align:start position:0% +well the formal solution is it's no + + + align:start position:0% +well the formal solution is it's no +longer a point a single point a nice + + align:start position:0% +longer a point a single point a nice + + + align:start position:0% +longer a point a single point a nice +column vector of of fluxes it's now an + + align:start position:0% +column vector of of fluxes it's now an + + + align:start position:0% +column vector of of fluxes it's now an +entire feasible space + + align:start position:0% +entire feasible space + + + align:start position:0% +entire feasible space +this is the kind of the cop-out answer + + align:start position:0% +this is the kind of the cop-out answer + + + align:start position:0% +this is the kind of the cop-out answer +is that okay we have fewer equations + + align:start position:0% +is that okay we have fewer equations + + + align:start position:0% +is that okay we have fewer equations +than we have unknowns that means the + + align:start position:0% +than we have unknowns that means the + + + align:start position:0% +than we have unknowns that means the +unknowns can occupy this entire + + align:start position:0% +unknowns can occupy this entire + + + align:start position:0% +unknowns can occupy this entire +multi-dimensional space where however + + align:start position:0% +multi-dimensional space where however + + + align:start position:0% +multi-dimensional space where however +many fluxes you have if you have + + align:start position:0% +many fluxes you have if you have + + + align:start position:0% +many fluxes you have if you have +hundreds of fluxes you'll have hundreds + + align:start position:0% +hundreds of fluxes you'll have hundreds + + + align:start position:0% +hundreds of fluxes you'll have hundreds +of dimensions so you have three fluxes a + + align:start position:0% +of dimensions so you have three fluxes a + + + align:start position:0% +of dimensions so you have three fluxes a +b and c + + align:start position:0% +b and c + + + align:start position:0% +b and c +then you'll get this kind of + + align:start position:0% +then you'll get this kind of + + + align:start position:0% +then you'll get this kind of +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +multi-dimensional polyhedral region and + + align:start position:0% +multi-dimensional polyhedral region and + + + align:start position:0% +multi-dimensional polyhedral region and +anything inside that polyhedron is + + align:start position:0% +anything inside that polyhedron is + + + align:start position:0% +anything inside that polyhedron is +a is the acceptable solution to the + + align:start position:0% +a is the acceptable solution to the + + + align:start position:0% +a is the acceptable solution to the +under determined set well this is still + + align:start position:0% +under determined set well this is still + + + align:start position:0% +under determined set well this is still +progress in that you now know that + + align:start position:0% +progress in that you now know that + + + align:start position:0% +progress in that you now know that +that your solution is in there somewhere + + align:start position:0% + + + + align:start position:0% + +but what if we wanted to find + + align:start position:0% +but what if we wanted to find + + + align:start position:0% +but what if we wanted to find +add some more constraints which are not + + align:start position:0% +add some more constraints which are not + + + align:start position:0% +add some more constraints which are not +now exact constraints anymore but + + align:start position:0% +now exact constraints anymore but + + + align:start position:0% +now exact constraints anymore but +they're more + + align:start position:0% + + + + align:start position:0% + +an optimization process you might have + + align:start position:0% +an optimization process you might have + + + align:start position:0% +an optimization process you might have +this multi-dimensional polyhedron will + + align:start position:0% +this multi-dimensional polyhedron will + + + align:start position:0% +this multi-dimensional polyhedron will +be bounded by inequalities that it's + + align:start position:0% +be bounded by inequalities that it's + + + align:start position:0% +be bounded by inequalities that it's +less that's greater than zero right this + + align:start position:0% +less that's greater than zero right this + + + align:start position:0% +less that's greater than zero right this +positive or it's less of some maximum + + align:start position:0% +positive or it's less of some maximum + + + align:start position:0% +positive or it's less of some maximum +flux but then you want to find some + + align:start position:0% +flux but then you want to find some + + + align:start position:0% +flux but then you want to find some +optimal solution + + align:start position:0% +optimal solution + + + align:start position:0% +optimal solution +and the optimization + + align:start position:0% +and the optimization + + + align:start position:0% +and the optimization +is a + + align:start position:0% +is a + + + align:start position:0% +is a +is the sort of thing that + + align:start position:0% +is the sort of thing that + + + align:start position:0% +is the sort of thing that +that math has uh been harnessed for in + + align:start position:0% +that math has uh been harnessed for in + + + align:start position:0% +that math has uh been harnessed for in +some other fields outside of ours such + + align:start position:0% +some other fields outside of ours such + + + align:start position:0% +some other fields outside of ours such +as economics when you're doing uh + + align:start position:0% +as economics when you're doing uh + + + align:start position:0% +as economics when you're doing uh +planning of + + align:start position:0% +planning of + + + align:start position:0% +planning of +you know transport or planning of + + align:start position:0% +you know transport or planning of + + + align:start position:0% +you know transport or planning of +economic investments and so forth you + + align:start position:0% +economic investments and so forth you + + + align:start position:0% +economic investments and so forth you +want to know how much of your resources + + align:start position:0% +want to know how much of your resources + + + align:start position:0% +want to know how much of your resources +do you want to send through the x1 root + + align:start position:0% +do you want to send through the x1 root + + + align:start position:0% +do you want to send through the x1 root +and how much do you want to send to the + + align:start position:0% +and how much do you want to send to the + + + align:start position:0% +and how much do you want to send to the +x2 root very analogous to the you know + + align:start position:0% +x2 root very analogous to the you know + + + align:start position:0% +x2 root very analogous to the you know +the situation we had in the previous + + align:start position:0% +the situation we had in the previous + + + align:start position:0% +the situation we had in the previous +slide + + align:start position:0% +slide + + + align:start position:0% +slide +and + + align:start position:0% +and + + + align:start position:0% +and +and that that can be solved by linear + + align:start position:0% +and that that can be solved by linear + + + align:start position:0% +and that that can be solved by linear +programming when you're programming + + align:start position:0% +programming when you're programming + + + align:start position:0% +programming when you're programming +often finding economic applications + + align:start position:0% +often finding economic applications + + + align:start position:0% +often finding economic applications +so let's but we need to ask what is it + + align:start position:0% +so let's but we need to ask what is it + + + align:start position:0% +so let's but we need to ask what is it +we want to optimize in economics you + + align:start position:0% +we want to optimize in economics you + + + align:start position:0% +we want to optimize in economics you +want to optimize typically the bottom + + align:start position:0% +want to optimize typically the bottom + + + align:start position:0% +want to optimize typically the bottom +line + + align:start position:0% +line + + + align:start position:0% +line +you want to lower costs and increase + + align:start position:0% +you want to lower costs and increase + + + align:start position:0% +you want to lower costs and increase +profits + + align:start position:0% + + + + align:start position:0% + +the sort of what we have here is we have + + align:start position:0% +the sort of what we have here is we have + + + align:start position:0% +the sort of what we have here is we have +this + + align:start position:0% + + + + align:start position:0% + +very commonly encountered many metabolic + + align:start position:0% +very commonly encountered many metabolic + + + align:start position:0% +very commonly encountered many metabolic +systems where you have this convex + + align:start position:0% +systems where you have this convex + + + align:start position:0% +systems where you have this convex +polyhedral cone convex just means that + + align:start position:0% +polyhedral cone convex just means that + + + align:start position:0% +polyhedral cone convex just means that +there's uh + + align:start position:0% +there's uh + + + align:start position:0% +there's uh +there are no little + + align:start position:0% +there are no little + + + align:start position:0% +there are no little +gaps in it no little carved out regions + + align:start position:0% +gaps in it no little carved out regions + + + align:start position:0% +gaps in it no little carved out regions +it's it's all um + + align:start position:0% +it's it's all um + + + align:start position:0% +it's it's all um +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +uh contain + + align:start position:0% +uh contain + + + align:start position:0% +uh contain +that convexity allows you to have now + + align:start position:0% +that convexity allows you to have now + + + align:start position:0% +that convexity allows you to have now +take a linear objective function say a + + align:start position:0% +take a linear objective function say a + + + align:start position:0% +take a linear objective function say a +multi-dimensional plane or a line + + align:start position:0% +multi-dimensional plane or a line + + + align:start position:0% +multi-dimensional plane or a line +that that you then move through this + + align:start position:0% +that that you then move through this + + + align:start position:0% +that that you then move through this +convex space and since there are no gaps + + align:start position:0% +convex space and since there are no gaps + + + align:start position:0% +convex space and since there are no gaps +in it you eventually move off + + align:start position:0% +in it you eventually move off + + + align:start position:0% +in it you eventually move off +as you move this objective function to + + align:start position:0% +as you move this objective function to + + + align:start position:0% +as you move this objective function to +the objective function gets better and + + align:start position:0% +the objective function gets better and + + + align:start position:0% +the objective function gets better and +better as it goes off through this + + align:start position:0% +better as it goes off through this + + + align:start position:0% +better as it goes off through this +feasible space it eventually gets to a + + align:start position:0% +feasible space it eventually gets to a + + + align:start position:0% +feasible space it eventually gets to a +point + + align:start position:0% +point + + + align:start position:0% +point +where it leaves the feasible space and + + align:start position:0% +where it leaves the feasible space and + + + align:start position:0% +where it leaves the feasible space and +that is the maximum value the mo the + + align:start position:0% +that is the maximum value the mo the + + + align:start position:0% +that is the maximum value the mo the +optimal value for that objective + + align:start position:0% +optimal value for that objective + + + align:start position:0% +optimal value for that objective +function + + align:start position:0% +function + + + align:start position:0% +function +which so we can use this feasible space + + align:start position:0% +which so we can use this feasible space + + + align:start position:0% +which so we can use this feasible space +combined with this objective function to + + align:start position:0% +combined with this objective function to + + + align:start position:0% +combined with this objective function to +find some optimum + + align:start position:0% +find some optimum + + + align:start position:0% +find some optimum +now what is the objective function that + + align:start position:0% +now what is the objective function that + + + align:start position:0% +now what is the objective function that +we want to use + + align:start position:0% +we want to use + + + align:start position:0% +we want to use +and + + align:start position:0% +and + + + align:start position:0% +and +if we were doing red blood cell the + + align:start position:0% +if we were doing red blood cell the + + + align:start position:0% +if we were doing red blood cell the +objective function might be atp or redox + + align:start position:0% +objective function might be atp or redox + + + align:start position:0% +objective function might be atp or redox +or both or delivery oxygen + + align:start position:0% +or both or delivery oxygen + + + align:start position:0% +or both or delivery oxygen +and for a variety of other systems of + + align:start position:0% +and for a variety of other systems of + + + align:start position:0% +and for a variety of other systems of +importance to + + align:start position:0% +importance to + + + align:start position:0% +importance to +understanding + + align:start position:0% +understanding + + + align:start position:0% +understanding +health or biotechnology production + + align:start position:0% +health or biotechnology production + + + align:start position:0% +health or biotechnology production +or + + align:start position:0% +or + + + align:start position:0% +or +other + + align:start position:0% +other + + + align:start position:0% +other +medical and engineering goals + + align:start position:0% +medical and engineering goals + + + align:start position:0% +medical and engineering goals +what we want to optimize is that is + + align:start position:0% +what we want to optimize is that is + + + align:start position:0% +what we want to optimize is that is +biomass the ability of the cells to grow + + align:start position:0% +biomass the ability of the cells to grow + + + align:start position:0% +biomass the ability of the cells to grow +and produce + + align:start position:0% +and produce + + + align:start position:0% +and produce +other cells or produce a particular + + align:start position:0% +other cells or produce a particular + + + align:start position:0% +other cells or produce a particular +subset of molecules in the cell let's + + align:start position:0% +subset of molecules in the cell let's + + + align:start position:0% +subset of molecules in the cell let's +deal mainly with the case of of cells + + align:start position:0% +deal mainly with the case of of cells + + + align:start position:0% +deal mainly with the case of of cells +producing cells and what this is is a + + align:start position:0% +producing cells and what this is is a + + + align:start position:0% +producing cells and what this is is a +sum over all the monomers all the + + align:start position:0% +sum over all the monomers all the + + + align:start position:0% +sum over all the monomers all the +components of the cell which represent + + align:start position:0% +components of the cell which represent + + + align:start position:0% +components of the cell which represent +the body of the cell + + align:start position:0% +the body of the cell + + + align:start position:0% +the body of the cell +so as you + + align:start position:0% +so as you + + + align:start position:0% +so as you +move as you transport small molecules in + + align:start position:0% +move as you transport small molecules in + + + align:start position:0% +move as you transport small molecules in +from the environment and incorporate it + + align:start position:0% +from the environment and incorporate it + + + align:start position:0% +from the environment and incorporate it +into the cell that's certainly you can + + align:start position:0% +into the cell that's certainly you can + + + align:start position:0% +into the cell that's certainly you can +think of as a sink it's removing those + + align:start position:0% +think of as a sink it's removing those + + + align:start position:0% +think of as a sink it's removing those +molecules from circulation from some + + align:start position:0% +molecules from circulation from some + + + align:start position:0% +molecules from circulation from some +solution + + align:start position:0% +solution + + + align:start position:0% +solution +and this uh + + align:start position:0% +and this uh + + + align:start position:0% +and this uh +the sum over all the + + align:start position:0% + + + + align:start position:0% + +components the ratios d of the monomers + + align:start position:0% +components the ratios d of the monomers + + + align:start position:0% +components the ratios d of the monomers +you can think of there's a ratio fixed + + align:start position:0% +you can think of there's a ratio fixed + + + align:start position:0% +you can think of there's a ratio fixed +ratio of alanine to glycine to leucine + + align:start position:0% +ratio of alanine to glycine to leucine + + + align:start position:0% +ratio of alanine to glycine to leucine +to all the other components of the cell + + align:start position:0% +to all the other components of the cell + + + align:start position:0% +to all the other components of the cell +and this is + + align:start position:0% +and this is + + + align:start position:0% +and this is +known you can you can know this without + + align:start position:0% +known you can you can know this without + + + align:start position:0% +known you can you can know this without +knowing lots of other parts of the + + align:start position:0% +knowing lots of other parts of the + + + align:start position:0% +knowing lots of other parts of the +system you want to know just by taking + + align:start position:0% +system you want to know just by taking + + + align:start position:0% +system you want to know just by taking +the cell and doing a chemical + + align:start position:0% +the cell and doing a chemical + + + align:start position:0% +the cell and doing a chemical +composition on it very simple experiment + + align:start position:0% +composition on it very simple experiment + + + align:start position:0% +composition on it very simple experiment +their tables of this known provide + + align:start position:0% +their tables of this known provide + + + align:start position:0% +their tables of this known provide +variety of cells and it hardly changes + + align:start position:0% +variety of cells and it hardly changes + + + align:start position:0% +variety of cells and it hardly changes +depending on much on the how the cell is + + align:start position:0% +depending on much on the how the cell is + + + align:start position:0% +depending on much on the how the cell is +growing but + + align:start position:0% +growing but + + + align:start position:0% +growing but +what sources of carbon and nitrogen do + + align:start position:0% +what sources of carbon and nitrogen do + + + align:start position:0% +what sources of carbon and nitrogen do +not greatly affect the ratio of alanine + + align:start position:0% +not greatly affect the ratio of alanine + + + align:start position:0% +not greatly affect the ratio of alanine +leucine and glycine because those are + + align:start position:0% +leucine and glycine because those are + + + align:start position:0% +leucine and glycine because those are +determined by what it takes to run the + + align:start position:0% +determined by what it takes to run the + + + align:start position:0% +determined by what it takes to run the +cell so this is important flux you can + + align:start position:0% +cell so this is important flux you can + + + align:start position:0% +cell so this is important flux you can +think of this as a kind of a lumped flux + + align:start position:0% +think of this as a kind of a lumped flux + + + align:start position:0% +think of this as a kind of a lumped flux +and this will be our objective function + + align:start position:0% +and this will be our objective function + + + align:start position:0% +and this will be our objective function +as well so the executive function is z + + align:start position:0% +as well so the executive function is z + + + align:start position:0% +as well so the executive function is z +sometimes called so z is going to be + + align:start position:0% +sometimes called so z is going to be + + + align:start position:0% +sometimes called so z is going to be +equal to the flux + + align:start position:0% +equal to the flux + + + align:start position:0% +equal to the flux +of growth + + align:start position:0% +of growth + + + align:start position:0% +of growth +so you can see that you have again the + + align:start position:0% +so you can see that you have again the + + + align:start position:0% +so you can see that you have again the +same equation again stoichiometric + + align:start position:0% +same equation again stoichiometric + + + align:start position:0% +same equation again stoichiometric +matrix times the internal flux is equal + + align:start position:0% +matrix times the internal flux is equal + + + align:start position:0% +matrix times the internal flux is equal +to the uptake fluxes + + align:start position:0% +to the uptake fluxes + + + align:start position:0% +to the uptake fluxes +uh + + align:start position:0% +uh + + + align:start position:0% +uh +and we've got this now this uh + + align:start position:0% +and we've got this now this uh + + + align:start position:0% +and we've got this now this uh +constraint this optimization function + + align:start position:0% +constraint this optimization function + + + align:start position:0% +constraint this optimization function +so let's take a just like you had a very + + align:start position:0% +so let's take a just like you had a very + + + align:start position:0% +so let's take a just like you had a very +simple uh + + align:start position:0% + + + + align:start position:0% + +exact solution before now let's take + + align:start position:0% +exact solution before now let's take + + + align:start position:0% +exact solution before now let's take +this very simple linear programming or + + align:start position:0% +this very simple linear programming or + + + align:start position:0% +this very simple linear programming or +lp solution where now + + align:start position:0% +lp solution where now + + + align:start position:0% +lp solution where now +it's underdetermined so we can't get the + + align:start position:0% +it's underdetermined so we can't get the + + + align:start position:0% +it's underdetermined so we can't get the +exact solution but we can ask what's the + + align:start position:0% +exact solution but we can ask what's the + + + align:start position:0% +exact solution but we can ask what's the +maximum for a particular objective + + align:start position:0% +maximum for a particular objective + + + align:start position:0% +maximum for a particular objective +function the objective function here is + + align:start position:0% +function the objective function here is + + + align:start position:0% +function the objective function here is +not going to be the biomass production + + align:start position:0% +not going to be the biomass production + + + align:start position:0% +not going to be the biomass production +of the entire cell it's going to be + + align:start position:0% +of the entire cell it's going to be + + + align:start position:0% +of the entire cell it's going to be +either maximizing the production of d + + align:start position:0% +either maximizing the production of d + + + align:start position:0% +either maximizing the production of d +or + + align:start position:0% +or + + + align:start position:0% +or +c + + align:start position:0% +c + + + align:start position:0% +c +now this is a slightly different diagram + + align:start position:0% +now this is a slightly different diagram + + + align:start position:0% +now this is a slightly different diagram +than we had before we still have the + + align:start position:0% +than we had before we still have the + + + align:start position:0% +than we had before we still have the +rate of uptake of a on the left side of + + align:start position:0% +rate of uptake of a on the left side of + + + align:start position:0% +rate of uptake of a on the left side of +this kind of circular pseudo cell a goes + + align:start position:0% +this kind of circular pseudo cell a goes + + + align:start position:0% +this kind of circular pseudo cell a goes +in it makes the same binary decision of + + align:start position:0% +in it makes the same binary decision of + + + align:start position:0% +in it makes the same binary decision of +or + + align:start position:0% +or + + + align:start position:0% +or +two-way decision of uh + + align:start position:0% +two-way decision of uh + + + align:start position:0% +two-way decision of uh +x1 versus x2 it's not binary instances + + align:start position:0% +x1 versus x2 it's not binary instances + + + align:start position:0% +x1 versus x2 it's not binary instances +quantitative uh + + align:start position:0% +quantitative uh + + + align:start position:0% +quantitative uh +you know + + align:start position:0% +you know + + + align:start position:0% +you know +real numbers determine how much x and + + align:start position:0% +real numbers determine how much x and + + + align:start position:0% +real numbers determine how much x and +how much x2 + + align:start position:0% +how much x2 + + + align:start position:0% +how much x2 +and then if it takes the upper x1 root + + align:start position:0% +and then if it takes the upper x1 root + + + align:start position:0% +and then if it takes the upper x1 root +then it uh splits into b and c if it + + align:start position:0% +then it uh splits into b and c if it + + + align:start position:0% +then it uh splits into b and c if it +takes the x2 root it turns into b and d + + align:start position:0% +takes the x2 root it turns into b and d + + + align:start position:0% +takes the x2 root it turns into b and d +both cases it produces a b molecule + + align:start position:0% +both cases it produces a b molecule + + + align:start position:0% +both cases it produces a b molecule +because you can always already see a + + align:start position:0% +because you can always already see a + + + align:start position:0% +because you can always already see a +constraint coming up here which is the r + + align:start position:0% +constraint coming up here which is the r + + + align:start position:0% +constraint coming up here which is the r +a is going to be for rb + + align:start position:0% +a is going to be for rb + + + align:start position:0% +a is going to be for rb +however you go from a + + align:start position:0% +however you go from a + + + align:start position:0% +however you go from a +to to the outside again it's going to + + align:start position:0% +to to the outside again it's going to + + + align:start position:0% +to to the outside again it's going to +it's going to produce one molecule of b + + align:start position:0% +it's going to produce one molecule of b + + + align:start position:0% +it's going to produce one molecule of b +for every molecule a this is a perfect + + align:start position:0% +for every molecule a this is a perfect + + + align:start position:0% +for every molecule a this is a perfect +conservation reaction + + align:start position:0% +conservation reaction + + + align:start position:0% +conservation reaction +and we've we've uh we've said that we're + + align:start position:0% +and we've we've uh we've said that we're + + + align:start position:0% +and we've we've uh we've said that we're +only interested in positive fluxes so + + align:start position:0% +only interested in positive fluxes so + + + align:start position:0% +only interested in positive fluxes so +you get this little triangle here of + + align:start position:0% +you get this little triangle here of + + + align:start position:0% +you get this little triangle here of +x1 and x2 are greater than zero + + align:start position:0% +x1 and x2 are greater than zero + + + align:start position:0% +x1 and x2 are greater than zero +and they're constrained in that that + + align:start position:0% +and they're constrained in that that + + + align:start position:0% +and they're constrained in that that +we've said that + + align:start position:0% +we've said that + + + align:start position:0% +we've said that +r a we're going to clamp so that it + + align:start position:0% +r a we're going to clamp so that it + + + align:start position:0% +r a we're going to clamp so that it +can't have more than uh one on this + + align:start position:0% +can't have more than uh one on this + + + align:start position:0% +can't have more than uh one on this +arbitrary + + align:start position:0% +arbitrary + + + align:start position:0% +arbitrary +moles per liter per minute say + + align:start position:0% + + + + align:start position:0% + +and so x x1 plus x2 are constrained to + + align:start position:0% +and so x x1 plus x2 are constrained to + + + align:start position:0% +and so x x1 plus x2 are constrained to +be less than ra so they're less than one + + align:start position:0% +be less than ra so they're less than one + + + align:start position:0% +be less than ra so they're less than one +as well so you get this feasible space + + align:start position:0% +as well so you get this feasible space + + + align:start position:0% +as well so you get this feasible space +which is this diagonally cross-hatched + + align:start position:0% +which is this diagonally cross-hatched + + + align:start position:0% +which is this diagonally cross-hatched +region + + align:start position:0% +region + + + align:start position:0% +region +and that's that's the exact that's the + + align:start position:0% +and that's that's the exact that's the + + + align:start position:0% +and that's that's the exact that's the +exact solution that's the set of all + + align:start position:0% +exact solution that's the set of all + + + align:start position:0% +exact solution that's the set of all +exact solutions + + align:start position:0% +exact solutions + + + align:start position:0% +exact solutions +but now if you want to maximize a + + align:start position:0% +but now if you want to maximize a + + + align:start position:0% +but now if you want to maximize a +particular objective function z in this + + align:start position:0% +particular objective function z in this + + + align:start position:0% +particular objective function z in this +case let's maximize the production of d + + align:start position:0% +case let's maximize the production of d + + + align:start position:0% +case let's maximize the production of d +and we're not too concerned about + + align:start position:0% +and we're not too concerned about + + + align:start position:0% +and we're not too concerned about +anything else + + align:start position:0% +anything else + + + align:start position:0% +anything else +then then you get this line you can + + align:start position:0% +then then you get this line you can + + + align:start position:0% +then then you get this line you can +think of this as a hyperplane going you + + align:start position:0% +think of this as a hyperplane going you + + + align:start position:0% +think of this as a hyperplane going you +know a line basically going + + align:start position:0% +know a line basically going + + + align:start position:0% +know a line basically going +up through feasible space starting at + + align:start position:0% +up through feasible space starting at + + + align:start position:0% +up through feasible space starting at +the bottom of the slide going up and up + + align:start position:0% +the bottom of the slide going up and up + + + align:start position:0% +the bottom of the slide going up and up +and up until it just barely leaves the + + align:start position:0% +and up until it just barely leaves the + + + align:start position:0% +and up until it just barely leaves the +feasible space and when it does the last + + align:start position:0% +feasible space and when it does the last + + + align:start position:0% +feasible space and when it does the last +point it gets to is the maximum and the + + align:start position:0% +point it gets to is the maximum and the + + + align:start position:0% +point it gets to is the maximum and the +maximum happens here to be + + align:start position:0% +maximum happens here to be + + + align:start position:0% +maximum happens here to be +x1 equals 0 x2 equal to the max + + align:start position:0% +x1 equals 0 x2 equal to the max + + + align:start position:0% +x1 equals 0 x2 equal to the max +rd maximum rate of production of + + align:start position:0% +rd maximum rate of production of + + + align:start position:0% +rd maximum rate of production of +the molecule we're interested + + align:start position:0% +the molecule we're interested + + + align:start position:0% +the molecule we're interested +if we had an objective function that + + align:start position:0% +if we had an objective function that + + + align:start position:0% +if we had an objective function that +went off + + align:start position:0% +went off + + + align:start position:0% +went off +the other axis it would be x2 0 and x1 + + align:start position:0% +the other axis it would be x2 0 and x1 + + + align:start position:0% +the other axis it would be x2 0 and x1 +equal to maximum rc + + align:start position:0% +equal to maximum rc + + + align:start position:0% +equal to maximum rc +so you can see how this works we create + + align:start position:0% +so you can see how this works we create + + + align:start position:0% +so you can see how this works we create +the feasible space we've + + align:start position:0% +the feasible space we've + + + align:start position:0% +the feasible space we've +designed an objective function z + + align:start position:0% +designed an objective function z + + + align:start position:0% +designed an objective function z +and we run the z off the edge of this + + align:start position:0% +and we run the z off the edge of this + + + align:start position:0% +and we run the z off the edge of this +convex space it's important to be convex + + align:start position:0% +convex space it's important to be convex + + + align:start position:0% +convex space it's important to be convex +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so how applicable is linear programming + + align:start position:0% +so how applicable is linear programming + + + align:start position:0% +so how applicable is linear programming +and so-called flux balance analysis + + align:start position:0% +and so-called flux balance analysis + + + align:start position:0% +and so-called flux balance analysis +it works when the stoichiometry is well + + align:start position:0% +it works when the stoichiometry is well + + + align:start position:0% +it works when the stoichiometry is well +known + + align:start position:0% +known + + + align:start position:0% +known +for e coli it's well known for newly + + align:start position:0% +for e coli it's well known for newly + + + align:start position:0% +for e coli it's well known for newly +sequenced genomes we can make + + align:start position:0% +sequenced genomes we can make + + + align:start position:0% +sequenced genomes we can make +connections to previous + + align:start position:0% +connections to previous + + + align:start position:0% +connections to previous +enzymatic reactions and we can guess + + align:start position:0% +enzymatic reactions and we can guess + + + align:start position:0% +enzymatic reactions and we can guess +that what the stoichiometric matrix + + align:start position:0% +that what the stoichiometric matrix + + + align:start position:0% +that what the stoichiometric matrix +would be + + align:start position:0% +would be + + + align:start position:0% +would be +but in that case the stoichiometry is + + align:start position:0% +but in that case the stoichiometry is + + + align:start position:0% +but in that case the stoichiometry is +less well-known and in which case you're + + align:start position:0% +less well-known and in which case you're + + + align:start position:0% +less well-known and in which case you're +going to have to really embrace your + + align:start position:0% +going to have to really embrace your + + + align:start position:0% +going to have to really embrace your +outliers when you get to the end you're + + align:start position:0% +outliers when you get to the end you're + + + align:start position:0% +outliers when you get to the end you're +going to see all the errors and go back + + align:start position:0% +going to see all the errors and go back + + + align:start position:0% +going to see all the errors and go back +and figure out what was wrong with our + + align:start position:0% +and figure out what was wrong with our + + + align:start position:0% +and figure out what was wrong with our +stoichiometric matrix derived from our + + align:start position:0% +stoichiometric matrix derived from our + + + align:start position:0% +stoichiometric matrix derived from our +genome + + align:start position:0% + + + + align:start position:0% + +you don't need much + + align:start position:0% + + + + align:start position:0% + +experimental information to run this + + align:start position:0% +experimental information to run this + + + align:start position:0% +experimental information to run this +but you you need some and we'll we'll + + align:start position:0% +but you you need some and we'll we'll + + + align:start position:0% +but you you need some and we'll we'll +explore two of them or at least to test + + align:start position:0% +explore two of them or at least to test + + + align:start position:0% +explore two of them or at least to test +how it how it's going to to do data + + align:start position:0% +how it how it's going to to do data + + + align:start position:0% +how it how it's going to to do data +so what are the + + align:start position:0% +so what are the + + + align:start position:0% +so what are the +precursors to cell growth + + align:start position:0% +precursors to cell growth + + + align:start position:0% +precursors to cell growth +that we are + + align:start position:0% +that we are + + + align:start position:0% +that we are +monitoring as a z function okay + + align:start position:0% +monitoring as a z function okay + + + align:start position:0% +monitoring as a z function okay +we want to come up with define this + + align:start position:0% +we want to come up with define this + + + align:start position:0% +we want to come up with define this +growth function + + align:start position:0% +growth function + + + align:start position:0% +growth function +in terms of biomass + + align:start position:0% +in terms of biomass + + + align:start position:0% +in terms of biomass +and there's like i say there's tables of + + align:start position:0% +and there's like i say there's tables of + + + align:start position:0% +and there's like i say there's tables of +of + + align:start position:0% +of + + + align:start position:0% +of +composition we'll show one in a couple + + align:start position:0% +composition we'll show one in a couple + + + align:start position:0% +composition we'll show one in a couple +of slides + + align:start position:0% +of slides + + + align:start position:0% +of slides +but you can use this as a + + align:start position:0% + + + + align:start position:0% + +part of the complete metabolic network + + align:start position:0% +part of the complete metabolic network + + + align:start position:0% +part of the complete metabolic network +you can also use the observation + + align:start position:0% +you can also use the observation + + + align:start position:0% +you can also use the observation +function + + align:start position:0% +function + + + align:start position:0% +function +it can be described as some small number + + align:start position:0% +it can be described as some small number + + + align:start position:0% +it can be described as some small number +of biosynthetic precursors plus the + + align:start position:0% +of biosynthetic precursors plus the + + + align:start position:0% +of biosynthetic precursors plus the +energy and redox cofactors + + align:start position:0% +energy and redox cofactors + + + align:start position:0% +energy and redox cofactors +now there are many ways of doing in + + align:start position:0% +now there are many ways of doing in + + + align:start position:0% +now there are many ways of doing in +silico cells we show red blood cells + + align:start position:0% +silico cells we show red blood cells + + + align:start position:0% +silico cells we show red blood cells +ordinary addition equation + + align:start position:0% +ordinary addition equation + + + align:start position:0% +ordinary addition equation +the kind of in silica cells here with + + align:start position:0% +the kind of in silica cells here with + + + align:start position:0% +the kind of in silica cells here with +optimization is fairly limited the + + align:start position:0% +optimization is fairly limited the + + + align:start position:0% +optimization is fairly limited the +stoichiometric matrices have only been + + align:start position:0% +stoichiometric matrices have only been + + + align:start position:0% +stoichiometric matrices have only been +worked out for three maybe five cells + + align:start position:0% +worked out for three maybe five cells + + + align:start position:0% +worked out for three maybe five cells +three published + + align:start position:0% +three published + + + align:start position:0% +three published +yeast is on its way + + align:start position:0% + + + + align:start position:0% + +and this is these are mostly hand + + align:start position:0% +and this is these are mostly hand + + + align:start position:0% +and this is these are mostly hand +curated there is definitely a need for + + align:start position:0% +curated there is definitely a need for + + + align:start position:0% +curated there is definitely a need for +getting a more automated input from + + align:start position:0% +getting a more automated input from + + + align:start position:0% +getting a more automated input from +genomic models to these + + align:start position:0% +genomic models to these + + + align:start position:0% +genomic models to these +flux + + align:start position:0% +flux + + + align:start position:0% +flux +analyses + + align:start position:0% +analyses + + + align:start position:0% +analyses +here's some references here we'll be + + align:start position:0% +here's some references here we'll be + + + align:start position:0% +here's some references here we'll be +talking in a moment + + align:start position:0% +talking in a moment + + + align:start position:0% +talking in a moment +first we'll talk about the wild type + + align:start position:0% +first we'll talk about the wild type + + + align:start position:0% +first we'll talk about the wild type +case for each of these cells under a + + align:start position:0% +case for each of these cells under a + + + align:start position:0% +case for each of these cells under a +variety of different growth conditions + + align:start position:0% +variety of different growth conditions + + + align:start position:0% +variety of different growth conditions +then we'll move on to mutants and ask + + align:start position:0% +then we'll move on to mutants and ask + + + align:start position:0% +then we'll move on to mutants and ask +whether mutants or we expect to be + + align:start position:0% +whether mutants or we expect to be + + + align:start position:0% +whether mutants or we expect to be +optimal or not + + align:start position:0% +optimal or not + + + align:start position:0% +optimal or not +and that will be called minimization of + + align:start position:0% +and that will be called minimization of + + + align:start position:0% +and that will be called minimization of +metabolic adjustment + + align:start position:0% +metabolic adjustment + + + align:start position:0% +metabolic adjustment +now where do these stoichiometric + + align:start position:0% +now where do these stoichiometric + + + align:start position:0% +now where do these stoichiometric +matrices come from + + align:start position:0% +matrices come from + + + align:start position:0% +matrices come from +parenthetically the kinetic parameters + + align:start position:0% +parenthetically the kinetic parameters + + + align:start position:0% +parenthetically the kinetic parameters +that we're talking about + + align:start position:0% +that we're talking about + + + align:start position:0% +that we're talking about +are known for some of these complicated + + align:start position:0% +are known for some of these complicated + + + align:start position:0% +are known for some of these complicated +biochemical systems not just for red + + align:start position:0% +biochemical systems not just for red + + + align:start position:0% +biochemical systems not just for red +blood cell + + align:start position:0% +blood cell + + + align:start position:0% +blood cell +and where both the stoichiometric + + align:start position:0% +and where both the stoichiometric + + + align:start position:0% +and where both the stoichiometric +matrices and the kinetic parameters come + + align:start position:0% +matrices and the kinetic parameters come + + + align:start position:0% +matrices and the kinetic parameters come +from of course is a vast literature it's + + align:start position:0% +from of course is a vast literature it's + + + align:start position:0% +from of course is a vast literature it's +an unwieldy literature in the sense it + + align:start position:0% +an unwieldy literature in the sense it + + + align:start position:0% +an unwieldy literature in the sense it +was done at the time before anybody + + align:start position:0% +was done at the time before anybody + + + align:start position:0% +was done at the time before anybody +thought that we were going to be that + + align:start position:0% +thought that we were going to be that + + + align:start position:0% +thought that we were going to be that +they were going to be responsible for + + align:start position:0% +they were going to be responsible for + + + align:start position:0% +they were going to be responsible for +getting this into + + align:start position:0% +getting this into + + + align:start position:0% +getting this into +computer parcelable databases + + align:start position:0% +computer parcelable databases + + + align:start position:0% +computer parcelable databases +so it's mostly been re-entered + + align:start position:0% +so it's mostly been re-entered + + + align:start position:0% +so it's mostly been re-entered +by technicians into databases and you'll + + align:start position:0% +by technicians into databases and you'll + + + align:start position:0% +by technicians into databases and you'll +end up with these diagrams such as the + + align:start position:0% +end up with these diagrams such as the + + + align:start position:0% +end up with these diagrams such as the +central one where + + align:start position:0% +central one where + + + align:start position:0% +central one where +each of these boxes contains a is a node + + align:start position:0% +each of these boxes contains a is a node + + + align:start position:0% +each of these boxes contains a is a node +that contains a substrate and the lines + + align:start position:0% +that contains a substrate and the lines + + + align:start position:0% +that contains a substrate and the lines +are have enzyme commission numbers this + + align:start position:0% +are have enzyme commission numbers this + + + align:start position:0% +are have enzyme commission numbers this +you know this dotted you know this is a + + align:start position:0% +you know this dotted you know this is a + + + align:start position:0% +you know this dotted you know this is a +decimal + + align:start position:0% +decimal + + + align:start position:0% +decimal +multiple decimal point uh showing a + + align:start position:0% +multiple decimal point uh showing a + + + align:start position:0% +multiple decimal point uh showing a +hierarchical classification + + align:start position:0% +hierarchical classification + + + align:start position:0% +hierarchical classification +going from left to right getting more + + align:start position:0% +going from left to right getting more + + + align:start position:0% +going from left to right getting more +and more detailed in the enzymatic + + align:start position:0% +and more detailed in the enzymatic + + + align:start position:0% +and more detailed in the enzymatic +reaction + + align:start position:0% +reaction + + + align:start position:0% +reaction +and + + align:start position:0% +and + + + align:start position:0% +and +this is built up in a database and from + + align:start position:0% +this is built up in a database and from + + + align:start position:0% +this is built up in a database and from +this you can + + align:start position:0% +this you can + + + align:start position:0% +this you can +you can + + align:start position:0% +you can + + + align:start position:0% +you can +access such things as effects of kinetic + + align:start position:0% +access such things as effects of kinetic + + + align:start position:0% +access such things as effects of kinetic +constants effects of ph + + align:start position:0% +constants effects of ph + + + align:start position:0% +constants effects of ph +um + + align:start position:0% + + + + align:start position:0% + +and and other details + + align:start position:0% +and and other details + + + align:start position:0% +and and other details +and also from this you can get the + + align:start position:0% +and also from this you can get the + + + align:start position:0% +and also from this you can get the +stoichiometric uh matrices in principle + + align:start position:0% +stoichiometric uh matrices in principle + + + align:start position:0% +stoichiometric uh matrices in principle +because here you can see that you've got + + align:start position:0% +because here you can see that you've got + + + align:start position:0% +because here you can see that you've got +say + + align:start position:0% +say + + + align:start position:0% +say +an + + align:start position:0% +an + + + align:start position:0% +an +input of adp plus glucose 6-phosphate + + align:start position:0% +input of adp plus glucose 6-phosphate + + + align:start position:0% +input of adp plus glucose 6-phosphate +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +going into this reaction or coming out + + align:start position:0% +going into this reaction or coming out + + + align:start position:0% +going into this reaction or coming out +depending on which direction you're + + align:start position:0% +depending on which direction you're + + + align:start position:0% +depending on which direction you're +going + + align:start position:0% +going + + + align:start position:0% +going +and so those convert to zeros and ones + + align:start position:0% +and so those convert to zeros and ones + + + align:start position:0% +and so those convert to zeros and ones +in the matrix + + align:start position:0% +in the matrix + + + align:start position:0% +in the matrix +that's the source of the stoichiometric + + align:start position:0% +that's the source of the stoichiometric + + + align:start position:0% +that's the source of the stoichiometric +matrix which tells you what reactions + + align:start position:0% +matrix which tells you what reactions + + + align:start position:0% +matrix which tells you what reactions +are allowed what two + + align:start position:0% +are allowed what two + + + align:start position:0% +are allowed what two +things can come together or one + + align:start position:0% +things can come together or one + + + align:start position:0% +things can come together or one +thing can be converted by the various + + align:start position:0% +thing can be converted by the various + + + align:start position:0% +thing can be converted by the various +enzymes that actually exist in cells and + + align:start position:0% +enzymes that actually exist in cells and + + + align:start position:0% +enzymes that actually exist in cells and +you can toggle those on and off either + + align:start position:0% +you can toggle those on and off either + + + align:start position:0% +you can toggle those on and off either +by regulation or by evolutionary change + + align:start position:0% +by regulation or by evolutionary change + + + align:start position:0% +by regulation or by evolutionary change +or by genetic manipulation or + + align:start position:0% +or by genetic manipulation or + + + align:start position:0% +or by genetic manipulation or +mutagenesis you can basically have a + + align:start position:0% +mutagenesis you can basically have a + + + align:start position:0% +mutagenesis you can basically have a +universal matrix and you toggle on only + + align:start position:0% +universal matrix and you toggle on only + + + align:start position:0% +universal matrix and you toggle on only +the ones that you think happen in your + + align:start position:0% +the ones that you think happen in your + + + align:start position:0% +the ones that you think happen in your +organism + + align:start position:0% +organism + + + align:start position:0% +organism +that's how you get the stoichiometric + + align:start position:0% +that's how you get the stoichiometric + + + align:start position:0% +that's how you get the stoichiometric +matrix how you get the optimization + + align:start position:0% +matrix how you get the optimization + + + align:start position:0% +matrix how you get the optimization +function the z function to tell which is + + align:start position:0% +function the z function to tell which is + + + align:start position:0% +function the z function to tell which is +what how you want to make those + + align:start position:0% +what how you want to make those + + + align:start position:0% +what how you want to make those +decisions how much x1 and how much x2 + + align:start position:0% +decisions how much x1 and how much x2 + + + align:start position:0% +decisions how much x1 and how much x2 +this is dependent on the biomass + + align:start position:0% +this is dependent on the biomass + + + align:start position:0% +this is dependent on the biomass +composition and the biomass composition + + align:start position:0% +composition and the biomass composition + + + align:start position:0% +composition and the biomass composition +as we you know said we have + + align:start position:0% +as we you know said we have + + + align:start position:0% +as we you know said we have +on the vertical axis here is the + + align:start position:0% +on the vertical axis here is the + + + align:start position:0% +on the vertical axis here is the +coefficient + + align:start position:0% +coefficient + + + align:start position:0% +coefficient +in the growth reaction + + align:start position:0% + + + + align:start position:0% + +which ranges here over almost eight logs + + align:start position:0% +which ranges here over almost eight logs + + + align:start position:0% +which ranges here over almost eight logs +from the from the lowest uh + + align:start position:0% +from the from the lowest uh + + + align:start position:0% +from the from the lowest uh +compositional + + align:start position:0% +compositional + + + align:start position:0% +compositional +fraction which are some of these + + align:start position:0% +fraction which are some of these + + + align:start position:0% +fraction which are some of these +coenzymes so just like enzymes they only + + align:start position:0% +coenzymes so just like enzymes they only + + + align:start position:0% +coenzymes so just like enzymes they only +need in + + align:start position:0% +need in + + + align:start position:0% +need in +small amounts + + align:start position:0% +small amounts + + + align:start position:0% +small amounts +to these that are needed both for + + align:start position:0% +to these that are needed both for + + + align:start position:0% +to these that are needed both for +major + + align:start position:0% +major + + + align:start position:0% +major +participants in hundreds of reactions + + align:start position:0% +participants in hundreds of reactions + + + align:start position:0% +participants in hundreds of reactions +like atp + + align:start position:0% +like atp + + + align:start position:0% +like atp +some of which contribute heavily to + + align:start position:0% +some of which contribute heavily to + + + align:start position:0% +some of which contribute heavily to +biomass so atp also contributes to + + align:start position:0% +biomass so atp also contributes to + + + align:start position:0% +biomass so atp also contributes to +you know large biomass like ribosomal + + align:start position:0% +you know large biomass like ribosomal + + + align:start position:0% +you know large biomass like ribosomal +rna + + align:start position:0% +rna + + + align:start position:0% +rna +and then the various amino acids which + + align:start position:0% +and then the various amino acids which + + + align:start position:0% +and then the various amino acids which +tend to be some of these + + align:start position:0% +tend to be some of these + + + align:start position:0% +tend to be some of these +many of these stars up at the higher + + align:start position:0% +many of these stars up at the higher + + + align:start position:0% +many of these stars up at the higher +levels like lysine leucine and the other + + align:start position:0% +levels like lysine leucine and the other + + + align:start position:0% +levels like lysine leucine and the other +18 amino acids + + align:start position:0% +18 amino acids + + + align:start position:0% +18 amino acids +okay so this these are + + align:start position:0% +okay so this these are + + + align:start position:0% +okay so this these are +examples of the numbers that would go + + align:start position:0% +examples of the numbers that would go + + + align:start position:0% +examples of the numbers that would go +into the + + align:start position:0% +into the + + + align:start position:0% +into the +optimization curve here these red + + align:start position:0% +optimization curve here these red + + + align:start position:0% +optimization curve here these red +hyperplanes + + align:start position:0% +hyperplanes + + + align:start position:0% +hyperplanes +would be that linear sum in the ratios + + align:start position:0% +would be that linear sum in the ratios + + + align:start position:0% +would be that linear sum in the ratios +in the previous slide + + align:start position:0% +in the previous slide + + + align:start position:0% +in the previous slide +now + + align:start position:0% + + + + align:start position:0% + +we've already seen we've already worked + + align:start position:0% +we've already seen we've already worked + + + align:start position:0% +we've already seen we've already worked +through an example where we slid one of + + align:start position:0% +through an example where we slid one of + + + align:start position:0% +through an example where we slid one of +these hyperplanes off the edge of in a + + align:start position:0% +these hyperplanes off the edge of in a + + + align:start position:0% +these hyperplanes off the edge of in a +two-dimensional model and got the + + align:start position:0% +two-dimensional model and got the + + + align:start position:0% +two-dimensional model and got the +optimum production of a particular + + align:start position:0% +optimum production of a particular + + + align:start position:0% +optimum production of a particular +substance d + + align:start position:0% +substance d + + + align:start position:0% +substance d +but now we're trying to optimize this + + align:start position:0% +but now we're trying to optimize this + + + align:start position:0% +but now we're trying to optimize this +linear sum of all the + + align:start position:0% +linear sum of all the + + + align:start position:0% +linear sum of all the +metabolites that go into the body of the + + align:start position:0% +metabolites that go into the body of the + + + align:start position:0% +metabolites that go into the body of the +organism + + align:start position:0% +organism + + + align:start position:0% +organism +and just focus on the green feasible + + align:start position:0% +and just focus on the green feasible + + + align:start position:0% +and just focus on the green feasible +space it's actually some of it's hidden + + align:start position:0% +space it's actually some of it's hidden + + + align:start position:0% +space it's actually some of it's hidden +behind the yellow but imagine this this + + align:start position:0% +behind the yellow but imagine this this + + + align:start position:0% +behind the yellow but imagine this this +whole + + align:start position:0% +whole + + + align:start position:0% +whole +convex polyhedron + + align:start position:0% +convex polyhedron + + + align:start position:0% +convex polyhedron +of green which is feasible space fs for + + align:start position:0% +of green which is feasible space fs for + + + align:start position:0% +of green which is feasible space fs for +wild type wt + + align:start position:0% +wild type wt + + + align:start position:0% +wild type wt +and you can get an optimum you assume + + align:start position:0% +and you can get an optimum you assume + + + align:start position:0% +and you can get an optimum you assume +that this optim whatever the conditions + + align:start position:0% +that this optim whatever the conditions + + + align:start position:0% +that this optim whatever the conditions +that you're looking at + + align:start position:0% +that you're looking at + + + align:start position:0% +that you're looking at +has uh + + align:start position:0% +has uh + + + align:start position:0% +has uh +is likely to be achieved because for + + align:start position:0% +is likely to be achieved because for + + + align:start position:0% +is likely to be achieved because for +millions + + align:start position:0% +millions + + + align:start position:0% +millions +uh of years this organism has been + + align:start position:0% +uh of years this organism has been + + + align:start position:0% +uh of years this organism has been +living through all the different growth + + align:start position:0% +living through all the different growth + + + align:start position:0% +living through all the different growth +scenarios growth on glucose + + align:start position:0% +scenarios growth on glucose + + + align:start position:0% +scenarios growth on glucose +galactose various nitrogen sources and + + align:start position:0% +galactose various nitrogen sources and + + + align:start position:0% +galactose various nitrogen sources and +so forth so + + align:start position:0% +so forth so + + + align:start position:0% +so forth so +no matter what reasonable set of + + align:start position:0% +no matter what reasonable set of + + + align:start position:0% +no matter what reasonable set of +conditions you throw at it it's seen + + align:start position:0% +conditions you throw at it it's seen + + + align:start position:0% +conditions you throw at it it's seen +something like that before or some other + + align:start position:0% +something like that before or some other + + + align:start position:0% +something like that before or some other +combinations and so it's optimal for it + + align:start position:0% +combinations and so it's optimal for it + + + align:start position:0% +combinations and so it's optimal for it +and that's what that that that + + align:start position:0% +and that's what that that that + + + align:start position:0% +and that's what that that that +top + + align:start position:0% +top + + + align:start position:0% +top +right red dot means that's the option + + align:start position:0% +right red dot means that's the option + + + align:start position:0% +right red dot means that's the option +for the wild type moving this hyper + + align:start position:0% +for the wild type moving this hyper + + + align:start position:0% +for the wild type moving this hyper +plane which is the growth the sum of all + + align:start position:0% +plane which is the growth the sum of all + + + align:start position:0% +plane which is the growth the sum of all +the different growth components in the + + align:start position:0% +the different growth components in the + + + align:start position:0% +the different growth components in the +correct ratio so if you're going to + + align:start position:0% +correct ratio so if you're going to + + + align:start position:0% +correct ratio so if you're going to +optimize all those decisions x1s and x2s + + align:start position:0% +optimize all those decisions x1s and x2s + + + align:start position:0% +optimize all those decisions x1s and x2s +so that you get the right ratios so you + + align:start position:0% +so that you get the right ratios so you + + + align:start position:0% +so that you get the right ratios so you +don't get way too much say of some rare + + align:start position:0% +don't get way too much say of some rare + + + align:start position:0% +don't get way too much say of some rare +amino acid like tryptophan and not + + align:start position:0% +amino acid like tryptophan and not + + + align:start position:0% +amino acid like tryptophan and not +enough of the glycine say that's + + align:start position:0% +enough of the glycine say that's + + + align:start position:0% +enough of the glycine say that's +or alanine it's most common + + align:start position:0% +or alanine it's most common + + + align:start position:0% +or alanine it's most common +that's great for wild type under a + + align:start position:0% +that's great for wild type under a + + + align:start position:0% +that's great for wild type under a +variety of different growth conditions + + align:start position:0% +variety of different growth conditions + + + align:start position:0% +variety of different growth conditions +but what if you throw a real + + align:start position:0% +but what if you throw a real + + + align:start position:0% +but what if you throw a real +curveball and say + + align:start position:0% + + + + align:start position:0% + +not give it a condition but but give it + + align:start position:0% +not give it a condition but but give it + + + align:start position:0% +not give it a condition but but give it +a perturbation it really doesn't see + + align:start position:0% +a perturbation it really doesn't see + + + align:start position:0% +a perturbation it really doesn't see +very often if at all which would be to + + align:start position:0% +very often if at all which would be to + + + align:start position:0% +very often if at all which would be to +knock out a gene completely by deletion + + align:start position:0% +knock out a gene completely by deletion + + + align:start position:0% +knock out a gene completely by deletion +or conceivably knock in a gene add a + + align:start position:0% +or conceivably knock in a gene add a + + + align:start position:0% +or conceivably knock in a gene add a +gene that it hasn't seen before very + + align:start position:0% +gene that it hasn't seen before very + + + align:start position:0% +gene that it hasn't seen before very +often + + align:start position:0% +often + + + align:start position:0% +often +well now you could say we're going to do + + align:start position:0% +well now you could say we're going to do + + + align:start position:0% +well now you could say we're going to do +the same optimization we'll run the same + + align:start position:0% +the same optimization we'll run the same + + + align:start position:0% +the same optimization we'll run the same +red hyper plane through the new phase so + + align:start position:0% +red hyper plane through the new phase so + + + align:start position:0% +red hyper plane through the new phase so +the new feasible space is + + align:start position:0% +the new feasible space is + + + align:start position:0% +the new feasible space is +reduced if it's a knockout could be + + align:start position:0% +reduced if it's a knockout could be + + + align:start position:0% +reduced if it's a knockout could be +increased if it's a knock in where + + align:start position:0% +increased if it's a knock in where + + + align:start position:0% +increased if it's a knock in where +you're adding a gene but if in this + + align:start position:0% +you're adding a gene but if in this + + + align:start position:0% +you're adding a gene but if in this +reduced space the the original optimum + + align:start position:0% +reduced space the the original optimum + + + align:start position:0% +reduced space the the original optimum +is no longer accessible and if you rerun + + align:start position:0% +is no longer accessible and if you rerun + + + align:start position:0% +is no longer accessible and if you rerun +the optimization running this plane off + + align:start position:0% +the optimization running this plane off + + + align:start position:0% +the optimization running this plane off +the edge you'll find a new red dot in + + align:start position:0% +the edge you'll find a new red dot in + + + align:start position:0% +the edge you'll find a new red dot in +the yellow space + + align:start position:0% +the yellow space + + + align:start position:0% +the yellow space +which is a knockout optimum + + align:start position:0% +which is a knockout optimum + + + align:start position:0% +which is a knockout optimum +but that could take after you do the + + align:start position:0% +but that could take after you do the + + + align:start position:0% +but that could take after you do the +knockout it could take evolutionary + + align:start position:0% +knockout it could take evolutionary + + + align:start position:0% +knockout it could take evolutionary +times or at least long lab times + + align:start position:0% +times or at least long lab times + + + align:start position:0% +times or at least long lab times +to allow all the other + + align:start position:0% +to allow all the other + + + align:start position:0% +to allow all the other +genes to mutate and be selected so they + + align:start position:0% +genes to mutate and be selected so they + + + align:start position:0% +genes to mutate and be selected so they +accommodate this new knockout + + align:start position:0% +accommodate this new knockout + + + align:start position:0% +accommodate this new knockout +that the wild type had plenty of time to + + align:start position:0% +that the wild type had plenty of time to + + + align:start position:0% +that the wild type had plenty of time to +do that had millions of years + + align:start position:0% +do that had millions of years + + + align:start position:0% +do that had millions of years +the yellow feasible space for the + + align:start position:0% +the yellow feasible space for the + + + align:start position:0% +the yellow feasible space for the +knockout may not have had that so you + + align:start position:0% +knockout may not have had that so you + + + align:start position:0% +knockout may not have had that so you +want to know what's this immediate + + align:start position:0% +want to know what's this immediate + + + align:start position:0% +want to know what's this immediate +response and for its immediate response + + align:start position:0% +response and for its immediate response + + + align:start position:0% +response and for its immediate response +you might imagine is you know showing + + align:start position:0% +you might imagine is you know showing + + + align:start position:0% +you might imagine is you know showing +here is an orthogonal + + align:start position:0% +here is an orthogonal + + + align:start position:0% +here is an orthogonal +you know a closest distance think of + + align:start position:0% +you know a closest distance think of + + + align:start position:0% +you know a closest distance think of +this as an euclidean distance + + align:start position:0% +this as an euclidean distance + + + align:start position:0% +this as an euclidean distance +in this multi-dimensional space between + + align:start position:0% +in this multi-dimensional space between + + + align:start position:0% +in this multi-dimensional space between +the wild type optimum and the projection + + align:start position:0% +the wild type optimum and the projection + + + align:start position:0% +the wild type optimum and the projection +onto the feasible space of the mutant + + align:start position:0% +onto the feasible space of the mutant + + + align:start position:0% +onto the feasible space of the mutant +now that distance + + align:start position:0% +now that distance + + + align:start position:0% +now that distance +the distance you should already start to + + align:start position:0% +the distance you should already start to + + + align:start position:0% +the distance you should already start to +be thinking that this is no longer + + align:start position:0% +be thinking that this is no longer + + + align:start position:0% +be thinking that this is no longer +linear programming this may be quadratic + + align:start position:0% +linear programming this may be quadratic + + + align:start position:0% +linear programming this may be quadratic +because the distance is a quadratic + + align:start position:0% +because the distance is a quadratic + + + align:start position:0% +because the distance is a quadratic +function + + align:start position:0% +function + + + align:start position:0% +function +um + + align:start position:0% + + + + align:start position:0% + +and we'll see in particular since + + align:start position:0% +and we'll see in particular since + + + align:start position:0% +and we'll see in particular since +there's certain pathologies where you + + align:start position:0% +there's certain pathologies where you + + + align:start position:0% +there's certain pathologies where you +really are forced to take you can't just + + align:start position:0% +really are forced to take you can't just + + + align:start position:0% +really are forced to take you can't just +take a projection + + align:start position:0% +take a projection + + + align:start position:0% +take a projection +because sometimes those projections + + align:start position:0% +because sometimes those projections + + + align:start position:0% +because sometimes those projections +could + + align:start position:0% +could + + + align:start position:0% +could +can end up in a part of a space which is + + align:start position:0% +can end up in a part of a space which is + + + align:start position:0% +can end up in a part of a space which is +not feasible it's not this projection + + align:start position:0% +not feasible it's not this projection + + + align:start position:0% +not feasible it's not this projection +does not land on the yellow feasible + + align:start position:0% +does not land on the yellow feasible + + + align:start position:0% +does not land on the yellow feasible +space fs of the knockout so what you + + align:start position:0% +space fs of the knockout so what you + + + align:start position:0% +space fs of the knockout so what you +need to do is + + align:start position:0% +need to do is + + + align:start position:0% +need to do is +nudge this + + align:start position:0% +nudge this + + + align:start position:0% +nudge this +purple + + align:start position:0% +purple + + + align:start position:0% +purple +symbol up + + align:start position:0% +symbol up + + + align:start position:0% +symbol up +just to the nearest point of the + + align:start position:0% +just to the nearest point of the + + + align:start position:0% +just to the nearest point of the +feasible space which is minimizes the + + align:start position:0% +feasible space which is minimizes the + + + align:start position:0% +feasible space which is minimizes the +distance to the wild type optimum + + align:start position:0% +distance to the wild type optimum + + + align:start position:0% +distance to the wild type optimum +and still falls in feasible space now + + align:start position:0% +and still falls in feasible space now + + + align:start position:0% +and still falls in feasible space now +this is a quadratic programming + + align:start position:0% +this is a quadratic programming + + + align:start position:0% +this is a quadratic programming +algorithm it's it's really you know just + + align:start position:0% +algorithm it's it's really you know just + + + align:start position:0% +algorithm it's it's really you know just +the linear is very simple to think of is + + align:start position:0% +the linear is very simple to think of is + + + align:start position:0% +the linear is very simple to think of is +just moving this uh + + align:start position:0% +just moving this uh + + + align:start position:0% +just moving this uh +plane off the edge of the convex space + + align:start position:0% +plane off the edge of the convex space + + + align:start position:0% +plane off the edge of the convex space +quadratic programming is a bit more + + align:start position:0% +quadratic programming is a bit more + + + align:start position:0% +quadratic programming is a bit more +complicated but i think you get the idea + + align:start position:0% +complicated but i think you get the idea + + + align:start position:0% +complicated but i think you get the idea +you're minimizing that distance + + align:start position:0% +you're minimizing that distance + + + align:start position:0% +you're minimizing that distance +okay + + align:start position:0% +okay + + + align:start position:0% +okay +now + + align:start position:0% +now + + + align:start position:0% +now +with any good modeling exercise there + + align:start position:0% +with any good modeling exercise there + + + align:start position:0% +with any good modeling exercise there +should be some data lurking in the wings + + align:start position:0% +should be some data lurking in the wings + + + align:start position:0% +should be some data lurking in the wings +many of the network models that we will + + align:start position:0% +many of the network models that we will + + + align:start position:0% +many of the network models that we will +do are getting more ambitious than the + + align:start position:0% +do are getting more ambitious than the + + + align:start position:0% +do are getting more ambitious than the +even the massive amounts of data coming + + align:start position:0% +even the massive amounts of data coming + + + align:start position:0% +even the massive amounts of data coming +in + + align:start position:0% +in + + + align:start position:0% +in +this + + align:start position:0% +this + + + align:start position:0% +this +there are two + + align:start position:0% +there are two + + + align:start position:0% +there are two +types of data that might lead to mind as + + align:start position:0% +types of data that might lead to mind as + + + align:start position:0% +types of data that might lead to mind as +being appropriate for this uh remember + + align:start position:0% +being appropriate for this uh remember + + + align:start position:0% +being appropriate for this uh remember +we said + + align:start position:0% +we said + + + align:start position:0% +we said +that what the organism has done is + + align:start position:0% +that what the organism has done is + + + align:start position:0% +that what the organism has done is +optimize the use of these networks + + align:start position:0% +optimize the use of these networks + + + align:start position:0% +optimize the use of these networks +so that you can maximize growth so the + + align:start position:0% +so that you can maximize growth so the + + + align:start position:0% +so that you can maximize growth so the +two sources of data that you'd want to + + align:start position:0% +two sources of data that you'd want to + + + align:start position:0% +two sources of data that you'd want to +test this + + align:start position:0% +test this + + + align:start position:0% +test this +with would be the flux state itself + + align:start position:0% +with would be the flux state itself + + + align:start position:0% +with would be the flux state itself +because you're saying you're predicting + + align:start position:0% +because you're saying you're predicting + + + align:start position:0% +because you're saying you're predicting +how much is going to be going in each + + align:start position:0% +how much is going to be going in each + + + align:start position:0% +how much is going to be going in each +flux direction + + align:start position:0% +flux direction + + + align:start position:0% +flux direction +and the growth data so it's you're + + align:start position:0% +and the growth data so it's you're + + + align:start position:0% +and the growth data so it's you're +making predictions + + align:start position:0% +making predictions + + + align:start position:0% +making predictions +that you will optimally use the fluxes + + align:start position:0% +that you will optimally use the fluxes + + + align:start position:0% +that you will optimally use the fluxes +in the network in order to maximize + + align:start position:0% +in the network in order to maximize + + + align:start position:0% +in the network in order to maximize +growth for various mutants + + align:start position:0% +growth for various mutants + + + align:start position:0% +growth for various mutants +and various different conditions of + + align:start position:0% +and various different conditions of + + + align:start position:0% +and various different conditions of +growth different carbon and nitrogen + + align:start position:0% +growth different carbon and nitrogen + + + align:start position:0% +growth different carbon and nitrogen +sources so + + align:start position:0% +sources so + + + align:start position:0% +sources so +here you have + + align:start position:0% +here you have + + + align:start position:0% +here you have +a + + align:start position:0% + + + + align:start position:0% + +group in zurich which is among the very + + align:start position:0% +group in zurich which is among the very + + + align:start position:0% +group in zurich which is among the very +few groups that can actually measure the + + align:start position:0% +few groups that can actually measure the + + + align:start position:0% +few groups that can actually measure the +measure the internal fluxes + + align:start position:0% + + + + align:start position:0% + +for metabolic pathways that begin with + + align:start position:0% +for metabolic pathways that begin with + + + align:start position:0% +for metabolic pathways that begin with +say isotopically labeled glucose and end + + align:start position:0% +say isotopically labeled glucose and end + + + align:start position:0% +say isotopically labeled glucose and end +in the various amino acids you can + + align:start position:0% +in the various amino acids you can + + + align:start position:0% +in the various amino acids you can +measure these + + align:start position:0% +measure these + + + align:start position:0% +measure these +we prepared ourselves for this a little + + align:start position:0% +we prepared ourselves for this a little + + + align:start position:0% +we prepared ourselves for this a little +bit in the last class where we talked + + align:start position:0% +bit in the last class where we talked + + + align:start position:0% +bit in the last class where we talked +about isotopomers where you can have + + align:start position:0% +about isotopomers where you can have + + + align:start position:0% +about isotopomers where you can have +different chemical compounds that + + align:start position:0% +different chemical compounds that + + + align:start position:0% +different chemical compounds that +whose + + align:start position:0% +whose + + + align:start position:0% +whose +only difference + + align:start position:0% +only difference + + + align:start position:0% +only difference +they have basically identical + + align:start position:0% +they have basically identical + + + align:start position:0% +they have basically identical +identically + + align:start position:0% +identically + + + align:start position:0% +identically +chemically but in different carbon + + align:start position:0% +chemically but in different carbon + + + align:start position:0% +chemically but in different carbon +positions you have a carbon 13 in one + + align:start position:0% +positions you have a carbon 13 in one + + + align:start position:0% +positions you have a carbon 13 in one +place carbon 12 + + align:start position:0% +place carbon 12 + + + align:start position:0% +place carbon 12 +another and the exact arrangement of + + align:start position:0% +another and the exact arrangement of + + + align:start position:0% +another and the exact arrangement of +carbon 12 and carbon 13s in this will + + align:start position:0% +carbon 12 and carbon 13s in this will + + + align:start position:0% +carbon 12 and carbon 13s in this will +determine the izotopia + + align:start position:0% +determine the izotopia + + + align:start position:0% +determine the izotopia +and if you have + + align:start position:0% +and if you have + + + align:start position:0% +and if you have +mixtures of carbon-12 and carbon-13 + + align:start position:0% +mixtures of carbon-12 and carbon-13 + + + align:start position:0% +mixtures of carbon-12 and carbon-13 +glucose + + align:start position:0% +glucose + + + align:start position:0% +glucose +in the upper + + align:start position:0% +in the upper + + + align:start position:0% +in the upper +left-hand corner of this + + align:start position:0% +left-hand corner of this + + + align:start position:0% +left-hand corner of this +diagram includes glycolysis and pentose + + align:start position:0% +diagram includes glycolysis and pentose + + + align:start position:0% +diagram includes glycolysis and pentose +phosphate and tca cycle + + align:start position:0% +phosphate and tca cycle + + + align:start position:0% +phosphate and tca cycle +this this isotopically labeled glucose + + align:start position:0% +this this isotopically labeled glucose + + + align:start position:0% +this this isotopically labeled glucose +goes through here and then you need a + + align:start position:0% +goes through here and then you need a + + + align:start position:0% +goes through here and then you need a +little bit of modeling that you know + + align:start position:0% +little bit of modeling that you know + + + align:start position:0% +little bit of modeling that you know +that we won't go into + + align:start position:0% +that we won't go into + + + align:start position:0% +that we won't go into +uh that but that does require a + + align:start position:0% +uh that but that does require a + + + align:start position:0% +uh that but that does require a +stoichiometric matrix just like our + + align:start position:0% +stoichiometric matrix just like our + + + align:start position:0% +stoichiometric matrix just like our +optimization modeling does but now very + + align:start position:0% +optimization modeling does but now very + + + align:start position:0% +optimization modeling does but now very +independently of that you need to + + align:start position:0% +independently of that you need to + + + align:start position:0% +independently of that you need to +ask how the isotopes of glucose would + + align:start position:0% +ask how the isotopes of glucose would + + + align:start position:0% +ask how the isotopes of glucose would +make their way into the amino acids and + + align:start position:0% +make their way into the amino acids and + + + align:start position:0% +make their way into the amino acids and +then once you have that then given the + + align:start position:0% +then once you have that then given the + + + align:start position:0% +then once you have that then given the +amino acid ratios by mass spectrum nmr + + align:start position:0% +amino acid ratios by mass spectrum nmr + + + align:start position:0% +amino acid ratios by mass spectrum nmr +you can go back and calculate what the + + align:start position:0% +you can go back and calculate what the + + + align:start position:0% +you can go back and calculate what the +fluxes must have been in here once you + + align:start position:0% +fluxes must have been in here once you + + + align:start position:0% +fluxes must have been in here once you +have those fluxes then you're going to + + align:start position:0% +have those fluxes then you're going to + + + align:start position:0% +have those fluxes then you're going to +ask how close to optimal are they for + + align:start position:0% +ask how close to optimal are they for + + + align:start position:0% +ask how close to optimal are they for +the wild type + + align:start position:0% +the wild type + + + align:start position:0% +the wild type +under one condition for the mutant under + + align:start position:0% +under one condition for the mutant under + + + align:start position:0% +under one condition for the mutant under +the same condition for the wild have + + align:start position:0% +the same condition for the wild have + + + align:start position:0% +the same condition for the wild have +been mutant under different conditions + + align:start position:0% +been mutant under different conditions + + + align:start position:0% +been mutant under different conditions +okay so this is the first class of data + + align:start position:0% +okay so this is the first class of data + + + align:start position:0% +okay so this is the first class of data +that we'll use and it's the internal + + align:start position:0% +that we'll use and it's the internal + + + align:start position:0% +that we'll use and it's the internal +fluxes for wild type and mutants + + align:start position:0% +fluxes for wild type and mutants + + + align:start position:0% +fluxes for wild type and mutants +uh + + align:start position:0% +uh + + + align:start position:0% +uh +look in the upper right hand corner + + align:start position:0% +look in the upper right hand corner + + + align:start position:0% +look in the upper right hand corner +where so you've got in the upper left + + align:start position:0% +where so you've got in the upper left + + + align:start position:0% +where so you've got in the upper left +hand corner is the icon color coded from + + align:start position:0% +hand corner is the icon color coded from + + + align:start position:0% +hand corner is the icon color coded from +the previous slide the upper right hand + + align:start position:0% +the previous slide the upper right hand + + + align:start position:0% +the previous slide the upper right hand +corner is the predictions for wild type + + align:start position:0% +corner is the predictions for wild type + + + align:start position:0% +corner is the predictions for wild type +using the linear programming or fba + + align:start position:0% +using the linear programming or fba + + + align:start position:0% +using the linear programming or fba +model you have predicted fluxes on the + + align:start position:0% +model you have predicted fluxes on the + + + align:start position:0% +model you have predicted fluxes on the +vertical axis + + align:start position:0% +vertical axis + + + align:start position:0% +vertical axis +and experimental fluxes on the + + align:start position:0% +and experimental fluxes on the + + + align:start position:0% +and experimental fluxes on the +horizontal axis + + align:start position:0% +horizontal axis + + + align:start position:0% +horizontal axis +you see here is + + align:start position:0% +you see here is + + + align:start position:0% +you see here is +a + + align:start position:0% +a + + + align:start position:0% +a +good correlation coefficient of about 90 + + align:start position:0% +good correlation coefficient of about 90 + + + align:start position:0% +good correlation coefficient of about 90 +plus percent + + align:start position:0% +plus percent + + + align:start position:0% +plus percent +and in and a probability that that this + + align:start position:0% +and in and a probability that that this + + + align:start position:0% +and in and a probability that that this +would you know not be random this is a a + + align:start position:0% +would you know not be random this is a a + + + align:start position:0% +would you know not be random this is a a +positive linear correlation + + align:start position:0% +positive linear correlation + + + align:start position:0% +positive linear correlation +is uh better than 10 to the minus + + align:start position:0% +is uh better than 10 to the minus + + + align:start position:0% +is uh better than 10 to the minus +seventh + + align:start position:0% +seventh + + + align:start position:0% +seventh +very unlikely that happened at random uh + + align:start position:0% +very unlikely that happened at random uh + + + align:start position:0% +very unlikely that happened at random uh +you know that you can focus in on the + + align:start position:0% +you know that you can focus in on the + + + align:start position:0% +you know that you can focus in on the +outliers like number 18 here but overall + + align:start position:0% +outliers like number 18 here but overall + + + align:start position:0% +outliers like number 18 here but overall +it's a good uh i mean and this can allow + + align:start position:0% +it's a good uh i mean and this can allow + + + align:start position:0% +it's a good uh i mean and this can allow +you to ask what experimental or model + + align:start position:0% +you to ask what experimental or model + + + align:start position:0% +you to ask what experimental or model +problems you might have + + align:start position:0% +problems you might have + + + align:start position:0% +problems you might have +but let's ask that's for wild type under + + align:start position:0% +but let's ask that's for wild type under + + + align:start position:0% +but let's ask that's for wild type under +uh you know common growth condition + + align:start position:0% +uh you know common growth condition + + + align:start position:0% +uh you know common growth condition +what about mutant under the same growth + + align:start position:0% +what about mutant under the same growth + + + align:start position:0% +what about mutant under the same growth +condition same + + align:start position:0% +condition same + + + align:start position:0% +condition same +stoichiometric modeling + + align:start position:0% +stoichiometric modeling + + + align:start position:0% +stoichiometric modeling +same measurements + + align:start position:0% +same measurements + + + align:start position:0% +same measurements +now the experimental fluxes versus + + align:start position:0% +now the experimental fluxes versus + + + align:start position:0% +now the experimental fluxes versus +predicted fluxes + + align:start position:0% +predicted fluxes + + + align:start position:0% +predicted fluxes +in the lower left-hand quadrant is + + align:start position:0% +in the lower left-hand quadrant is + + + align:start position:0% +in the lower left-hand quadrant is +almost completely random there's no + + align:start position:0% +almost completely random there's no + + + align:start position:0% +almost completely random there's no +positive or negative correlation that's + + align:start position:0% +positive or negative correlation that's + + + align:start position:0% +positive or negative correlation that's +significant + + align:start position:0% +significant + + + align:start position:0% +significant +as we might have expected + + align:start position:0% +as we might have expected + + + align:start position:0% +as we might have expected +for the mutant remember it isn't + + align:start position:0% +for the mutant remember it isn't + + + align:start position:0% +for the mutant remember it isn't +optimal so you don't expect the inner + + align:start position:0% +optimal so you don't expect the inner + + + align:start position:0% +optimal so you don't expect the inner +linear programming method which produces + + align:start position:0% +linear programming method which produces + + + align:start position:0% +linear programming method which produces +the optimum to be appropriate unless we + + align:start position:0% +the optimum to be appropriate unless we + + + align:start position:0% +the optimum to be appropriate unless we +had allowed this to + + align:start position:0% +had allowed this to + + + align:start position:0% +had allowed this to +evolve in the laboratory for hundreds of + + align:start position:0% +evolve in the laboratory for hundreds of + + + align:start position:0% +evolve in the laboratory for hundreds of +generations or a sufficient number + + align:start position:0% +generations or a sufficient number + + + align:start position:0% +generations or a sufficient number +however many that is + + align:start position:0% +however many that is + + + align:start position:0% +however many that is +to get all the other genes or enough of + + align:start position:0% +to get all the other genes or enough of + + + align:start position:0% +to get all the other genes or enough of +the other genes to adapt + + align:start position:0% +the other genes to adapt + + + align:start position:0% +the other genes to adapt +so you get near an optimum in any case + + align:start position:0% +so you get near an optimum in any case + + + align:start position:0% +so you get near an optimum in any case +this one is random if you now use the + + align:start position:0% +this one is random if you now use the + + + align:start position:0% +this one is random if you now use the +quadratic programming approach the moma + + align:start position:0% +quadratic programming approach the moma + + + align:start position:0% +quadratic programming approach the moma +or minimization of metabolic adjustment + + align:start position:0% +or minimization of metabolic adjustment + + + align:start position:0% +or minimization of metabolic adjustment +now get the very exciting result that it + + align:start position:0% +now get the very exciting result that it + + + align:start position:0% +now get the very exciting result that it +now becomes statistically significant + + align:start position:0% +now becomes statistically significant + + + align:start position:0% +now becomes statistically significant +again + + align:start position:0% +again + + + align:start position:0% +again +uh + + align:start position:0% +uh + + + align:start position:0% +uh +still a few outliers uh 17 and 16 here + + align:start position:0% +still a few outliers uh 17 and 16 here + + + align:start position:0% +still a few outliers uh 17 and 16 here +in magenta and these are things where + + align:start position:0% +in magenta and these are things where + + + align:start position:0% +in magenta and these are things where +you can now make very specific tests + + align:start position:0% +you can now make very specific tests + + + align:start position:0% +you can now make very specific tests +because now you know + + align:start position:0% +because now you know + + + align:start position:0% +because now you know +which is which ones are most + + align:start position:0% +which is which ones are most + + + align:start position:0% +which is which ones are most +discrepant between the experimental and + + align:start position:0% +discrepant between the experimental and + + + align:start position:0% +discrepant between the experimental and +predicted fluxes and you can go in and + + align:start position:0% +predicted fluxes and you can go in and + + + align:start position:0% +predicted fluxes and you can go in and +ask what part of that model or what part + + align:start position:0% +ask what part of that model or what part + + + align:start position:0% +ask what part of that model or what part +of that data collection might be + + align:start position:0% +of that data collection might be + + + align:start position:0% +of that data collection might be +accounting for the + + align:start position:0% +accounting for the + + + align:start position:0% +accounting for the +poor fit + + align:start position:0% +poor fit + + + align:start position:0% +poor fit +but overall this starts to give one the + + align:start position:0% +but overall this starts to give one the + + + align:start position:0% +but overall this starts to give one the +impression that maybe + + align:start position:0% +impression that maybe + + + align:start position:0% +impression that maybe +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +the mutants will not be optimal and that + + align:start position:0% +the mutants will not be optimal and that + + + align:start position:0% +the mutants will not be optimal and that +they can be somewhat better served by + + align:start position:0% +they can be somewhat better served by + + + align:start position:0% +they can be somewhat better served by +this not this + + align:start position:0% +this not this + + + align:start position:0% +this not this +quasi-non-optimal solution + + align:start position:0% +quasi-non-optimal solution + + + align:start position:0% +quasi-non-optimal solution +and if you walk through various + + align:start position:0% +and if you walk through various + + + align:start position:0% +and if you walk through various +different conditions + + align:start position:0% + + + + align:start position:0% + +with different knockouts you can see + + align:start position:0% +with different knockouts you can see + + + align:start position:0% +with different knockouts you can see +multiple examples of this so here in the + + align:start position:0% +multiple examples of this so here in the + + + align:start position:0% +multiple examples of this so here in the +upper left hand quadrant of slide 59 + + align:start position:0% +upper left hand quadrant of slide 59 + + + align:start position:0% +upper left hand quadrant of slide 59 +where we have the carbon limitation + + align:start position:0% +where we have the carbon limitation + + + align:start position:0% +where we have the carbon limitation +condition + + align:start position:0% +condition + + + align:start position:0% +condition +on the far left + + align:start position:0% +on the far left + + + align:start position:0% +on the far left +and then the comparison of the method + + align:start position:0% +and then the comparison of the method + + + align:start position:0% +and then the comparison of the method +for flux balance on wild type + + align:start position:0% +for flux balance on wild type + + + align:start position:0% +for flux balance on wild type +here's that + + align:start position:0% +here's that + + + align:start position:0% +here's that +0.9 correlation coefficient and good + + align:start position:0% +0.9 correlation coefficient and good + + + align:start position:0% +0.9 correlation coefficient and good +p-value + + align:start position:0% +p-value + + + align:start position:0% +p-value +and then comparing moma and fba and + + align:start position:0% +and then comparing moma and fba and + + + align:start position:0% +and then comparing moma and fba and +again + + align:start position:0% +again + + + align:start position:0% +again +the significance of switching from fba + + align:start position:0% +the significance of switching from fba + + + align:start position:0% +the significance of switching from fba +to moma is 3 times 10 to the minus 3 + + align:start position:0% +to moma is 3 times 10 to the minus 3 + + + align:start position:0% +to moma is 3 times 10 to the minus 3 +indicating that the quadratic + + align:start position:0% +indicating that the quadratic + + + align:start position:0% +indicating that the quadratic +programming is the more appropriate + + align:start position:0% +programming is the more appropriate + + + align:start position:0% +programming is the more appropriate +application here and as you walk through + + align:start position:0% +application here and as you walk through + + + align:start position:0% +application here and as you walk through +this you'll see + + align:start position:0% +this you'll see + + + align:start position:0% +this you'll see +many good correlation coefficients and + + align:start position:0% +many good correlation coefficients and + + + align:start position:0% +many good correlation coefficients and +many improvements when you go to the + + align:start position:0% +many improvements when you go to the + + + align:start position:0% +many improvements when you go to the +quadratic or moma + + align:start position:0% +quadratic or moma + + + align:start position:0% +quadratic or moma +not every case but certainly many of + + align:start position:0% +not every case but certainly many of + + + align:start position:0% +not every case but certainly many of +them + + align:start position:0% + + + + align:start position:0% + +now that's one + + align:start position:0% +now that's one + + + align:start position:0% +now that's one +class of tests which is the internal + + align:start position:0% +class of tests which is the internal + + + align:start position:0% +class of tests which is the internal +fluxes which the the + + align:start position:0% +fluxes which the the + + + align:start position:0% +fluxes which the the +idea is that you adjust the internal + + align:start position:0% +idea is that you adjust the internal + + + align:start position:0% +idea is that you adjust the internal +fluxes + + align:start position:0% +fluxes + + + align:start position:0% +fluxes +until they're optimal to produce growth + + align:start position:0% +until they're optimal to produce growth + + + align:start position:0% +until they're optimal to produce growth +well how about measuring growth itself + + align:start position:0% +well how about measuring growth itself + + + align:start position:0% +well how about measuring growth itself +on a set of mutants + + align:start position:0% +on a set of mutants + + + align:start position:0% +on a set of mutants +again these mutants you expect uh + + align:start position:0% +again these mutants you expect uh + + + align:start position:0% +again these mutants you expect uh +will will follow the the moma + + align:start position:0% +will will follow the the moma + + + align:start position:0% +will will follow the the moma +prediction slightly better + + align:start position:0% +prediction slightly better + + + align:start position:0% +prediction slightly better +and + + align:start position:0% +and + + + align:start position:0% +and +so slide 60 + + align:start position:0% +so slide 60 + + + align:start position:0% +so slide 60 +is a particular way of measuring + + align:start position:0% +is a particular way of measuring + + + align:start position:0% +is a particular way of measuring +a large genome wide set of mutants this + + align:start position:0% +a large genome wide set of mutants this + + + align:start position:0% +a large genome wide set of mutants this +is not a trivial undertaking we know how + + align:start position:0% +is not a trivial undertaking we know how + + + align:start position:0% +is not a trivial undertaking we know how +to measure a transcriptome set of rnas + + align:start position:0% +to measure a transcriptome set of rnas + + + align:start position:0% +to measure a transcriptome set of rnas +well on microarrays maybe there's an + + align:start position:0% +well on microarrays maybe there's an + + + align:start position:0% +well on microarrays maybe there's an +analogous way to measure + + align:start position:0% +analogous way to measure + + + align:start position:0% +analogous way to measure +uh whole genomes worth of mutants + + align:start position:0% +uh whole genomes worth of mutants + + + align:start position:0% +uh whole genomes worth of mutants +ideally you would have a mutant not just + + align:start position:0% +ideally you would have a mutant not just + + + align:start position:0% +ideally you would have a mutant not just +one per gene one knockout where you per + + align:start position:0% +one per gene one knockout where you per + + + align:start position:0% +one per gene one knockout where you per +gene which is a maybe a + + align:start position:0% +gene which is a maybe a + + + align:start position:0% +gene which is a maybe a +very expensive hand-crafted deletion but + + align:start position:0% +very expensive hand-crafted deletion but + + + align:start position:0% +very expensive hand-crafted deletion but +you'd have a little targeted mutation in + + align:start position:0% +you'd have a little targeted mutation in + + + align:start position:0% +you'd have a little targeted mutation in +every domain that contributes to that + + align:start position:0% +every domain that contributes to that + + + align:start position:0% +every domain that contributes to that +gene function + + align:start position:0% +gene function + + + align:start position:0% +gene function +mutations in the + + align:start position:0% +mutations in the + + + align:start position:0% +mutations in the +dna regulatory elements + + align:start position:0% +dna regulatory elements + + + align:start position:0% +dna regulatory elements +various protein domains + + align:start position:0% +various protein domains + + + align:start position:0% +various protein domains +rna stability domain and so on + + align:start position:0% +rna stability domain and so on + + + align:start position:0% +rna stability domain and so on +not quite at that level of ideal but + + align:start position:0% +not quite at that level of ideal but + + + align:start position:0% +not quite at that level of ideal but +getting close to it it's transposon + + align:start position:0% +getting close to it it's transposon + + + align:start position:0% +getting close to it it's transposon +mutagenesis where you insert small + + align:start position:0% +mutagenesis where you insert small + + + align:start position:0% +mutagenesis where you insert small +bits of dna randomly throughout the + + align:start position:0% +bits of dna randomly throughout the + + + align:start position:0% +bits of dna randomly throughout the +genome + + align:start position:0% +genome + + + align:start position:0% +genome +the + + align:start position:0% +the + + + align:start position:0% +the +modern + + align:start position:0% +modern + + + align:start position:0% +modern +set of commonly used transposons are + + align:start position:0% +set of commonly used transposons are + + + align:start position:0% +set of commonly used transposons are +pretty random in their assertion site + + align:start position:0% +pretty random in their assertion site + + + align:start position:0% +pretty random in their assertion site +choice + + align:start position:0% +choice + + + align:start position:0% +choice +and then you need a way of turning this + + align:start position:0% +and then you need a way of turning this + + + align:start position:0% +and then you need a way of turning this +collection of transposons into a readout + + align:start position:0% +collection of transposons into a readout + + + align:start position:0% +collection of transposons into a readout +of growth rates well one way to do this + + align:start position:0% +of growth rates well one way to do this + + + align:start position:0% +of growth rates well one way to do this +is have a population of + + align:start position:0% +is have a population of + + + align:start position:0% +is have a population of +cells each + + align:start position:0% +cells each + + + align:start position:0% +cells each +having + + align:start position:0% +having + + + align:start position:0% +having +their own distinctive transposon + + align:start position:0% +their own distinctive transposon + + + align:start position:0% +their own distinctive transposon +and growing them as a mixture + + align:start position:0% +and growing them as a mixture + + + align:start position:0% +and growing them as a mixture +and as growing and as they grow as a + + align:start position:0% +and as growing and as they grow as a + + + align:start position:0% +and as growing and as they grow as a +mixture + + align:start position:0% +mixture + + + align:start position:0% +mixture +the ones that that grow better + + align:start position:0% +the ones that that grow better + + + align:start position:0% +the ones that that grow better +will dominate the population + + align:start position:0% +will dominate the population + + + align:start position:0% +will dominate the population +and so their transposon hit the junction + + align:start position:0% +and so their transposon hit the junction + + + align:start position:0% +and so their transposon hit the junction +between the transpose the transposing is + + align:start position:0% +between the transpose the transposing is + + + align:start position:0% +between the transpose the transposing is +universal is present in every cell + + align:start position:0% +universal is present in every cell + + + align:start position:0% +universal is present in every cell +but where it + + align:start position:0% +but where it + + + align:start position:0% +but where it +sits is unique to that cell or nearly so + + align:start position:0% +sits is unique to that cell or nearly so + + + align:start position:0% +sits is unique to that cell or nearly so +so it sits in + + align:start position:0% +so it sits in + + + align:start position:0% +so it sits in +the junction between transposon and + + align:start position:0% +the junction between transposon and + + + align:start position:0% +the junction between transposon and +genome is unique and you want a way of + + align:start position:0% +genome is unique and you want a way of + + + align:start position:0% +genome is unique and you want a way of +assaying that what you actually that + + align:start position:0% +assaying that what you actually that + + + align:start position:0% +assaying that what you actually that +is you + + align:start position:0% +is you + + + align:start position:0% +is you +take the complete dna from the entire + + align:start position:0% +take the complete dna from the entire + + + align:start position:0% +take the complete dna from the entire +cell mixture + + align:start position:0% +cell mixture + + + align:start position:0% +cell mixture +and you want to say how much of each + + align:start position:0% +and you want to say how much of each + + + align:start position:0% +and you want to say how much of each +transposon exists so you cut the entire + + align:start position:0% +transposon exists so you cut the entire + + + align:start position:0% +transposon exists so you cut the entire +dna mixture with a restriction enzyme + + align:start position:0% +dna mixture with a restriction enzyme + + + align:start position:0% +dna mixture with a restriction enzyme +that cuts frequently so-called four + + align:start position:0% +that cuts frequently so-called four + + + align:start position:0% +that cuts frequently so-called four +cutter cuts with with about every 256 + + align:start position:0% +cutter cuts with with about every 256 + + + align:start position:0% +cutter cuts with with about every 256 +base pairs on average and you like it on + + align:start position:0% +base pairs on average and you like it on + + + align:start position:0% +base pairs on average and you like it on +this very special kind of linker which + + align:start position:0% +this very special kind of linker which + + + align:start position:0% +this very special kind of linker which +is a linker which will not amplify with + + align:start position:0% +is a linker which will not amplify with + + + align:start position:0% +is a linker which will not amplify with +the + + align:start position:0% +the + + + align:start position:0% +the +corresponding primer until some other + + align:start position:0% +corresponding primer until some other + + + align:start position:0% +corresponding primer until some other +dna synthesis has gone through because + + align:start position:0% +dna synthesis has gone through because + + + align:start position:0% +dna synthesis has gone through because +you see this little y + + align:start position:0% +you see this little y + + + align:start position:0% +you see this little y +linker is not perfectly waterproof base + + align:start position:0% +linker is not perfectly waterproof base + + + align:start position:0% +linker is not perfectly waterproof base +paired + + align:start position:0% +paired + + + align:start position:0% +paired +it + + align:start position:0% +it + + + align:start position:0% +it +requires + + align:start position:0% +requires + + + align:start position:0% +requires +dna polymerase to make a complement + + align:start position:0% +dna polymerase to make a complement + + + align:start position:0% +dna polymerase to make a complement +complement will bind the primer it's a + + align:start position:0% +complement will bind the primer it's a + + + align:start position:0% +complement will bind the primer it's a +long way of saying that only in cases + + align:start position:0% +long way of saying that only in cases + + + align:start position:0% +long way of saying that only in cases +where + + align:start position:0% +where + + + align:start position:0% +where +where you have a primer in the + + align:start position:0% +where you have a primer in the + + + align:start position:0% +where you have a primer in the +transposon near one of these y linkers + + align:start position:0% +transposon near one of these y linkers + + + align:start position:0% +transposon near one of these y linkers +will get amplification transposon alone + + align:start position:0% +will get amplification transposon alone + + + align:start position:0% +will get amplification transposon alone +you won't get it why link or alone you + + align:start position:0% +you won't get it why link or alone you + + + align:start position:0% +you won't get it why link or alone you +won't get it that's one step of + + align:start position:0% +won't get it that's one step of + + + align:start position:0% +won't get it that's one step of +enrichment and the reason you have to + + align:start position:0% +enrichment and the reason you have to + + + align:start position:0% +enrichment and the reason you have to +enrich is if you just through this whole + + align:start position:0% +enrich is if you just through this whole + + + align:start position:0% +enrich is if you just through this whole +thing on the microarray you get + + align:start position:0% +thing on the microarray you get + + + align:start position:0% +thing on the microarray you get +everything lighting up because every + + align:start position:0% +everything lighting up because every + + + align:start position:0% +everything lighting up because every +genome has every piece of the genome in + + align:start position:0% +genome has every piece of the genome in + + + align:start position:0% +genome has every piece of the genome in +it + + align:start position:0% + + + + align:start position:0% + +and the transposons are present in trace + + align:start position:0% +and the transposons are present in trace + + + align:start position:0% +and the transposons are present in trace +amounts + + align:start position:0% +amounts + + + align:start position:0% +amounts +so you need to amplify the junction + + align:start position:0% +so you need to amplify the junction + + + align:start position:0% +so you need to amplify the junction +fragment by first this trick followed by + + align:start position:0% +fragment by first this trick followed by + + + align:start position:0% +fragment by first this trick followed by +a t7 promoter this is a phage promoter + + align:start position:0% +a t7 promoter this is a phage promoter + + + align:start position:0% +a t7 promoter this is a phage promoter +very commonly used very clean + + align:start position:0% +very commonly used very clean + + + align:start position:0% +very commonly used very clean +rna polymerase background that's been + + align:start position:0% +rna polymerase background that's been + + + align:start position:0% +rna polymerase background that's been +incorporated into the any transpose on + + align:start position:0% +incorporated into the any transpose on + + + align:start position:0% +incorporated into the any transpose on +your favorite transposon so now you have + + align:start position:0% +your favorite transposon so now you have + + + align:start position:0% +your favorite transposon so now you have +two steps first this ligation mediated + + align:start position:0% +two steps first this ligation mediated + + + align:start position:0% +two steps first this ligation mediated +pcr and second the t7 in vitro + + align:start position:0% +pcr and second the t7 in vitro + + + align:start position:0% +pcr and second the t7 in vitro +transcription to make rna now you've + + align:start position:0% +transcription to make rna now you've + + + align:start position:0% +transcription to make rna now you've +basically reduced this to a problem + + align:start position:0% +basically reduced this to a problem + + + align:start position:0% +basically reduced this to a problem +similar to transcriptome + + align:start position:0% +similar to transcriptome + + + align:start position:0% +similar to transcriptome +uh microarrays we've done before now the + + align:start position:0% +uh microarrays we've done before now the + + + align:start position:0% +uh microarrays we've done before now the +rnas are surrogates for the amount of + + align:start position:0% +rnas are surrogates for the amount of + + + align:start position:0% +rnas are surrogates for the amount of +each strain + + align:start position:0% +each strain + + + align:start position:0% +each strain +we're not measuring rna we're made in + + align:start position:0% +we're not measuring rna we're made in + + + align:start position:0% +we're not measuring rna we're made in +rna that represents the transposon + + align:start position:0% +rna that represents the transposon + + + align:start position:0% +rna that represents the transposon +junction fragment and hence allows you + + align:start position:0% +junction fragment and hence allows you + + + align:start position:0% +junction fragment and hence allows you +to quantitate the amount of + + align:start position:0% +to quantitate the amount of + + + align:start position:0% +to quantitate the amount of +that particular mutant in a population + + align:start position:0% +that particular mutant in a population + + + align:start position:0% +that particular mutant in a population +as that mutant + + align:start position:0% +as that mutant + + + align:start position:0% +as that mutant +goes up or down in the population so + + align:start position:0% +goes up or down in the population so + + + align:start position:0% +goes up or down in the population so +does + + align:start position:0% +does + + + align:start position:0% +does +the rna from this assay + + align:start position:0% +the rna from this assay + + + align:start position:0% +the rna from this assay +so you might ask at this point + + align:start position:0% +so you might ask at this point + + + align:start position:0% +so you might ask at this point +well this is + + align:start position:0% +well this is + + + align:start position:0% +well this is +this is great but i don't trust it just + + align:start position:0% +this is great but i don't trust it just + + + align:start position:0% +this is great but i don't trust it just +like you some people might not have + + align:start position:0% +like you some people might not have + + + align:start position:0% +like you some people might not have +trusted mass spectrometry as being + + align:start position:0% +trusted mass spectrometry as being + + + align:start position:0% +trusted mass spectrometry as being +reproducible enough to be quantitative + + align:start position:0% +reproducible enough to be quantitative + + + align:start position:0% +reproducible enough to be quantitative +so the way that you determine whether + + align:start position:0% +so the way that you determine whether + + + align:start position:0% +so the way that you determine whether +something is sufficiently reproducible + + align:start position:0% +something is sufficiently reproducible + + + align:start position:0% +something is sufficiently reproducible +to be quantitative one way to do it is + + align:start position:0% +to be quantitative one way to do it is + + + align:start position:0% +to be quantitative one way to do it is +to do two independent selection + + align:start position:0% +to do two independent selection + + + align:start position:0% +to do two independent selection +experiments + + align:start position:0% +experiments + + + align:start position:0% +experiments +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +evolutionists might might say oh if we + + align:start position:0% +evolutionists might might say oh if we + + + align:start position:0% +evolutionists might might say oh if we +reran evolution all over again we would + + align:start position:0% +reran evolution all over again we would + + + align:start position:0% +reran evolution all over again we would +not get the same set of organisms we + + align:start position:0% +not get the same set of organisms we + + + align:start position:0% +not get the same set of organisms we +have on earth today that may be true but + + align:start position:0% +have on earth today that may be true but + + + align:start position:0% +have on earth today that may be true but +that's because there are all sorts of + + align:start position:0% +that's because there are all sorts of + + + align:start position:0% +that's because there are all sorts of +bottlenecks and historical events + + align:start position:0% +bottlenecks and historical events + + + align:start position:0% +bottlenecks and historical events +in this case + + align:start position:0% +in this case + + + align:start position:0% +in this case +we have + + align:start position:0% + + + + align:start position:0% + +we've specifically tried to make it + + align:start position:0% +we've specifically tried to make it + + + align:start position:0% +we've specifically tried to make it +reproducible by avoiding bottlenecks by + + align:start position:0% +reproducible by avoiding bottlenecks by + + + align:start position:0% +reproducible by avoiding bottlenecks by +having every mutation every transposon + + align:start position:0% +having every mutation every transposon + + + align:start position:0% +having every mutation every transposon +type represented by a thousand different + + align:start position:0% +type represented by a thousand different + + + align:start position:0% +type represented by a thousand different +independent events + + align:start position:0% +independent events + + + align:start position:0% +independent events +uh + + align:start position:0% +uh + + + align:start position:0% +uh +as well a thousand copies of every uh + + align:start position:0% +as well a thousand copies of every uh + + + align:start position:0% +as well a thousand copies of every uh +transposon hit so you keep the + + align:start position:0% +transposon hit so you keep the + + + align:start position:0% +transposon hit so you keep the +population size large and so it becomes + + align:start position:0% +population size large and so it becomes + + + align:start position:0% +population size large and so it becomes +more reproducible and this is and the + + align:start position:0% +more reproducible and this is and the + + + align:start position:0% +more reproducible and this is and the +way you measure the reproducibility you + + align:start position:0% +way you measure the reproducibility you + + + align:start position:0% +way you measure the reproducibility you +do the two selection experiments two uh + + align:start position:0% +do the two selection experiments two uh + + + align:start position:0% +do the two selection experiments two uh +independent um + + align:start position:0% +independent um + + + align:start position:0% +independent um +ideally independent sets of transposons + + align:start position:0% +ideally independent sets of transposons + + + align:start position:0% +ideally independent sets of transposons +subjected to exactly the same selection + + align:start position:0% +subjected to exactly the same selection + + + align:start position:0% +subjected to exactly the same selection +procedure and you see a very gratifying + + align:start position:0% +procedure and you see a very gratifying + + + align:start position:0% +procedure and you see a very gratifying +curve here with + + align:start position:0% +curve here with + + + align:start position:0% +curve here with +an r squared regression + + align:start position:0% +an r squared regression + + + align:start position:0% +an r squared regression +measure + + align:start position:0% +measure + + + align:start position:0% +measure +in excess of 98 percent and the kind of + + align:start position:0% +in excess of 98 percent and the kind of + + + align:start position:0% +in excess of 98 percent and the kind of +scatter that you would be pleased to get + + align:start position:0% +scatter that you would be pleased to get + + + align:start position:0% +scatter that you would be pleased to get +in an rna microarray experiment so this + + align:start position:0% +in an rna microarray experiment so this + + + align:start position:0% +in an rna microarray experiment so this +is reproducible and therefore + + align:start position:0% +is reproducible and therefore + + + align:start position:0% +is reproducible and therefore +quant + + align:start position:0% +quant + + + align:start position:0% +quant +capable of producing quantitative data + + align:start position:0% +capable of producing quantitative data + + + align:start position:0% +capable of producing quantitative data +well now let's go back and compare it + + align:start position:0% +well now let's go back and compare it + + + align:start position:0% +well now let's go back and compare it +to the two different methods of modeling + + align:start position:0% +to the two different methods of modeling + + + align:start position:0% +to the two different methods of modeling +the flux optimization + + align:start position:0% +the flux optimization + + + align:start position:0% +the flux optimization +there's the fba or linear programming + + align:start position:0% +there's the fba or linear programming + + + align:start position:0% +there's the fba or linear programming +which assumes that the mutant is + + align:start position:0% +which assumes that the mutant is + + + align:start position:0% +which assumes that the mutant is +immediately optimal and then there's the + + align:start position:0% +immediately optimal and then there's the + + + align:start position:0% +immediately optimal and then there's the +moma or minimization of + + align:start position:0% +moma or minimization of + + + align:start position:0% +moma or minimization of +metabolic adjustment which doesn't + + align:start position:0% +metabolic adjustment which doesn't + + + align:start position:0% +metabolic adjustment which doesn't +assume off immediate optimality but + + align:start position:0% +assume off immediate optimality but + + + align:start position:0% +assume off immediate optimality but +assumes that it's close to + + align:start position:0% +assumes that it's close to + + + align:start position:0% +assumes that it's close to +the wild type optimum so starting at the + + align:start position:0% +the wild type optimum so starting at the + + + align:start position:0% +the wild type optimum so starting at the +top + + align:start position:0% +top + + + align:start position:0% +top +the linear flux balance you can classify + + align:start position:0% +the linear flux balance you can classify + + + align:start position:0% +the linear flux balance you can classify +the production predictions of the model + + align:start position:0% +the production predictions of the model + + + align:start position:0% +the production predictions of the model +you can for each gene then here we have + + align:start position:0% +you can for each gene then here we have + + + align:start position:0% +you can for each gene then here we have +uh over + + align:start position:0% +uh over + + + align:start position:0% +uh over +you know + + align:start position:0% +you know + + + align:start position:0% +you know +almost 400 and almost 500 different + + align:start position:0% +almost 400 and almost 500 different + + + align:start position:0% +almost 400 and almost 500 different +genes + + align:start position:0% +genes + + + align:start position:0% +genes +mutated + + align:start position:0% +mutated + + + align:start position:0% +mutated +and you first you run through these + + align:start position:0% +and you first you run through these + + + align:start position:0% +and you first you run through these +silicon predictions you can classify + + align:start position:0% +silicon predictions you can classify + + + align:start position:0% +silicon predictions you can classify +them as being essential + + align:start position:0% +them as being essential + + + align:start position:0% +them as being essential +for a particular growth condition they + + align:start position:0% +for a particular growth condition they + + + align:start position:0% +for a particular growth condition they +aren't necessarily essential for every + + align:start position:0% +aren't necessarily essential for every + + + align:start position:0% +aren't necessarily essential for every +growth condition but the + + align:start position:0% +growth condition but the + + + align:start position:0% +growth condition but the +growth conditions here it's essential or + + align:start position:0% +growth conditions here it's essential or + + + align:start position:0% +growth conditions here it's essential or +non-essential or something in between + + align:start position:0% +non-essential or something in between + + + align:start position:0% +non-essential or something in between +we'll just focus on the extremes of + + align:start position:0% +we'll just focus on the extremes of + + + align:start position:0% +we'll just focus on the extremes of +essential and non-essential and then + + align:start position:0% +essential and non-essential and then + + + align:start position:0% +essential and non-essential and then +then the experiment can be classified as + + align:start position:0% +then the experiment can be classified as + + + align:start position:0% +then the experiment can be classified as +to whether there's uh + + align:start position:0% +to whether there's uh + + + align:start position:0% +to whether there's uh +significant negative selection or no + + align:start position:0% +significant negative selection or no + + + align:start position:0% +significant negative selection or no +noticeable selection under particular + + align:start position:0% +noticeable selection under particular + + + align:start position:0% +noticeable selection under particular +growth conditions and so you expect the + + align:start position:0% +growth conditions and so you expect the + + + align:start position:0% +growth conditions and so you expect the +ones to be essential in these growth + + align:start position:0% +ones to be essential in these growth + + + align:start position:0% +ones to be essential in these growth +conditions to be heavily negative + + align:start position:0% +conditions to be heavily negative + + + align:start position:0% +conditions to be heavily negative +selectively and you have 80 examples of + + align:start position:0% +selectively and you have 80 examples of + + + align:start position:0% +selectively and you have 80 examples of +that out of 142 predicted + + align:start position:0% +that out of 142 predicted + + + align:start position:0% +that out of 142 predicted +however you wouldn't expect they need to + + align:start position:0% +however you wouldn't expect they need to + + + align:start position:0% +however you wouldn't expect they need to +be + + align:start position:0% +be + + + align:start position:0% +be +missing in selection since they're + + align:start position:0% +missing in selection since they're + + + align:start position:0% +missing in selection since they're +essential so this 62 should be a 0 but a + + align:start position:0% +essential so this 62 should be a 0 but a + + + align:start position:0% +essential so this 62 should be a 0 but a +62. this is an example of what we're + + align:start position:0% +62. this is an example of what we're + + + align:start position:0% +62. this is an example of what we're +going to try to explain or use this as a + + align:start position:0% +going to try to explain or use this as a + + + align:start position:0% +going to try to explain or use this as a +way of generating interesting hypotheses + + align:start position:0% +way of generating interesting hypotheses + + + align:start position:0% +way of generating interesting hypotheses +about the exceptions or outliers + + align:start position:0% +about the exceptions or outliers + + + align:start position:0% +about the exceptions or outliers +similarly the non-essential genes should + + align:start position:0% +similarly the non-essential genes should + + + align:start position:0% +similarly the non-essential genes should +have no selection that's 180 in the + + align:start position:0% +have no selection that's 180 in the + + + align:start position:0% +have no selection that's 180 in the +lower right hand part of the upper + + align:start position:0% +lower right hand part of the upper + + + align:start position:0% +lower right hand part of the upper +fba + + align:start position:0% +fba + + + align:start position:0% +fba +but the 119 should be zero + + align:start position:0% +but the 119 should be zero + + + align:start position:0% +but the 119 should be zero +okay so one x the first pass explanation + + align:start position:0% +okay so one x the first pass explanation + + + align:start position:0% +okay so one x the first pass explanation +is okay we knew + + align:start position:0% +is okay we knew + + + align:start position:0% +is okay we knew +that these weren't going to be optimal + + align:start position:0% +that these weren't going to be optimal + + + align:start position:0% +that these weren't going to be optimal +right away so let's + + align:start position:0% +right away so let's + + + align:start position:0% +right away so let's +use the other model the the + + align:start position:0% +use the other model the the + + + align:start position:0% +use the other model the the +sub optimal nearly optimal model moma + + align:start position:0% +sub optimal nearly optimal model moma + + + align:start position:0% +sub optimal nearly optimal model moma +and see how well it does + + align:start position:0% +and see how well it does + + + align:start position:0% +and see how well it does +well on the far right hand side of slide + + align:start position:0% +well on the far right hand side of slide + + + align:start position:0% +well on the far right hand side of slide +62 you see the chi-square p-values how + + align:start position:0% +62 you see the chi-square p-values how + + + align:start position:0% +62 you see the chi-square p-values how +well the the + + align:start position:0% +well the the + + + align:start position:0% +well the the +predictions of agree with the uh + + align:start position:0% +predictions of agree with the uh + + + align:start position:0% +predictions of agree with the uh +observations and it is significant for + + align:start position:0% +observations and it is significant for + + + align:start position:0% +observations and it is significant for +the + + align:start position:0% +the + + + align:start position:0% +the +the + + align:start position:0% +the + + + align:start position:0% +the +linear programming it's 10 to the + + align:start position:0% +linear programming it's 10 to the + + + align:start position:0% +linear programming it's 10 to the +4 times 10 to the minus 3. fairly + + align:start position:0% +4 times 10 to the minus 3. fairly + + + align:start position:0% +4 times 10 to the minus 3. fairly +significant + + align:start position:0% +significant + + + align:start position:0% +significant +and the moma is much more significant to + + align:start position:0% +and the moma is much more significant to + + + align:start position:0% +and the moma is much more significant to +the minus five it has improved some of + + align:start position:0% +the minus five it has improved some of + + + align:start position:0% +the minus five it has improved some of +those uh + + align:start position:0% +those uh + + + align:start position:0% +those uh +uh upper + + align:start position:0% +uh upper + + + align:start position:0% +uh upper +right 66 and lower left 108. those + + align:start position:0% +right 66 and lower left 108. those + + + align:start position:0% +right 66 and lower left 108. those +should still be those should still be + + align:start position:0% +should still be those should still be + + + align:start position:0% +should still be those should still be +zero and they're not and the extent that + + align:start position:0% +zero and they're not and the extent that + + + align:start position:0% +zero and they're not and the extent that +they're they dv + + align:start position:0% +they're they dv + + + align:start position:0% +they're they dv +deviate from + + align:start position:0% +deviate from + + + align:start position:0% +deviate from +the ideal expectation means that either + + align:start position:0% +the ideal expectation means that either + + + align:start position:0% +the ideal expectation means that either +the data + + align:start position:0% +the data + + + align:start position:0% +the data +are somehow the way we're collecting the + + align:start position:0% +are somehow the way we're collecting the + + + align:start position:0% +are somehow the way we're collecting the +data not the way we expected it or that + + align:start position:0% +data not the way we expected it or that + + + align:start position:0% +data not the way we expected it or that +the + + align:start position:0% + + + + align:start position:0% + +model more likely the model has some + + align:start position:0% +model more likely the model has some + + + align:start position:0% +model more likely the model has some +problems in it and examples of problems + + align:start position:0% +problems in it and examples of problems + + + align:start position:0% +problems in it and examples of problems +for those two classes the + + align:start position:0% +for those two classes the + + + align:start position:0% +for those two classes the +predicted essential genes which show + + align:start position:0% +predicted essential genes which show + + + align:start position:0% +predicted essential genes which show +notes which uh + + align:start position:0% +notes which uh + + + align:start position:0% +notes which uh +show no selection might be examples of + + align:start position:0% +show no selection might be examples of + + + align:start position:0% +show no selection might be examples of +redundancies that we failed to model + + align:start position:0% +redundancies that we failed to model + + + align:start position:0% +redundancies that we failed to model +when we put together the stoichiometric + + align:start position:0% +when we put together the stoichiometric + + + align:start position:0% +when we put together the stoichiometric +matrix the stoichiometric matrix we take + + align:start position:0% +matrix the stoichiometric matrix we take + + + align:start position:0% +matrix the stoichiometric matrix we take +every known biochemical reaction + + align:start position:0% +every known biochemical reaction + + + align:start position:0% +every known biochemical reaction +we might take uh + + align:start position:0% +we might take uh + + + align:start position:0% +we might take uh +convincing homologs sequence homology + + align:start position:0% +convincing homologs sequence homology + + + align:start position:0% +convincing homologs sequence homology +level and say those might be examples of + + align:start position:0% +level and say those might be examples of + + + align:start position:0% +level and say those might be examples of +redundancy we might take analogous or + + align:start position:0% +redundancy we might take analogous or + + + align:start position:0% +redundancy we might take analogous or +parallel routes that are known + + align:start position:0% +parallel routes that are known + + + align:start position:0% +parallel routes that are known +documented biochemically where you can + + align:start position:0% +documented biochemically where you can + + + align:start position:0% +documented biochemically where you can +get to the same point by a series of + + align:start position:0% +get to the same point by a series of + + + align:start position:0% +get to the same point by a series of +possibly non-homo non-sequence + + align:start position:0% +possibly non-homo non-sequence + + + align:start position:0% +possibly non-homo non-sequence +homologous enzymatic steps so those are + + align:start position:0% +homologous enzymatic steps so those are + + + align:start position:0% +homologous enzymatic steps so those are +novel redundancies this is example of + + align:start position:0% +novel redundancies this is example of + + + align:start position:0% +novel redundancies this is example of +potential discovery + + align:start position:0% +potential discovery + + + align:start position:0% +potential discovery +and + + align:start position:0% +and + + + align:start position:0% +and +and can be pursued in a very directed + + align:start position:0% +and can be pursued in a very directed + + + align:start position:0% +and can be pursued in a very directed +way because these are 66 very specific + + align:start position:0% +way because these are 66 very specific + + + align:start position:0% +way because these are 66 very specific +predictions + + align:start position:0% +predictions + + + align:start position:0% +predictions +108 non-essential + + align:start position:0% +108 non-essential + + + align:start position:0% +108 non-essential +gene knockouts which nevertheless showed + + align:start position:0% +gene knockouts which nevertheless showed + + + align:start position:0% +gene knockouts which nevertheless showed +negative selection could be examples of + + align:start position:0% +negative selection could be examples of + + + align:start position:0% +negative selection could be examples of +position effects where a mutation in one + + align:start position:0% +position effects where a mutation in one + + + align:start position:0% +position effects where a mutation in one +gene affects + + align:start position:0% +gene affects + + + align:start position:0% +gene affects +other genes that are close along the dna + + align:start position:0% +other genes that are close along the dna + + + align:start position:0% +other genes that are close along the dna +position meaning along the dna any an + + align:start position:0% +position meaning along the dna any an + + + align:start position:0% +position meaning along the dna any an +example of this is that that a um + + align:start position:0% +example of this is that that a um + + + align:start position:0% +example of this is that that a um +a variety of mutations in a gene which + + align:start position:0% +a variety of mutations in a gene which + + + align:start position:0% +a variety of mutations in a gene which +is upstream from another gene in an + + align:start position:0% +is upstream from another gene in an + + + align:start position:0% +is upstream from another gene in an +operon + + align:start position:0% +operon + + + align:start position:0% +operon +have polar effects on downstream genes + + align:start position:0% +have polar effects on downstream genes + + + align:start position:0% +have polar effects on downstream genes +due to the coupling of transcription and + + align:start position:0% +due to the coupling of transcription and + + + align:start position:0% +due to the coupling of transcription and +translation you can have all you can + + align:start position:0% +translation you can have all you can + + + align:start position:0% +translation you can have all you can +have other kinds of position effects as + + align:start position:0% +have other kinds of position effects as + + + align:start position:0% +have other kinds of position effects as +well these are two + + align:start position:0% +well these are two + + + align:start position:0% +well these are two +these are examples of + + align:start position:0% +these are examples of + + + align:start position:0% +these are examples of +possibly many explanations and + + align:start position:0% +possibly many explanations and + + + align:start position:0% +possibly many explanations and +discoveries that can contribute to + + align:start position:0% +discoveries that can contribute to + + + align:start position:0% +discoveries that can contribute to +the wonderful nature of you know it's a + + align:start position:0% +the wonderful nature of you know it's a + + + align:start position:0% +the wonderful nature of you know it's a +win-win situation either you get great + + align:start position:0% +win-win situation either you get great + + + align:start position:0% +win-win situation either you get great +correlation + + align:start position:0% +correlation + + + align:start position:0% +correlation +or you get great exceptions and + + align:start position:0% +or you get great exceptions and + + + align:start position:0% +or you get great exceptions and +discoveries or both + + align:start position:0% +discoveries or both + + + align:start position:0% +discoveries or both +okay + + align:start position:0% + + + + align:start position:0% + +now + + align:start position:0% +now + + + align:start position:0% +now +when we talked about redundancy as one + + align:start position:0% +when we talked about redundancy as one + + + align:start position:0% +when we talked about redundancy as one +of the possible explanations in the + + align:start position:0% +of the possible explanations in the + + + align:start position:0% +of the possible explanations in the +previous slide that brings up really + + align:start position:0% +previous slide that brings up really + + + align:start position:0% +previous slide that brings up really +important uh conceptual component of the + + align:start position:0% +important uh conceptual component of the + + + align:start position:0% +important uh conceptual component of the +post-genomic functional genomic world + + align:start position:0% +post-genomic functional genomic world + + + align:start position:0% +post-genomic functional genomic world +which is + + align:start position:0% +which is + + + align:start position:0% +which is +that + + align:start position:0% +that + + + align:start position:0% +that +what do we do about multiple homologous + + align:start position:0% +what do we do about multiple homologous + + + align:start position:0% +what do we do about multiple homologous +domains when you go through and you + + align:start position:0% +domains when you go through and you + + + align:start position:0% +domains when you go through and you +sequence genomes you find paralogs you + + align:start position:0% +sequence genomes you find paralogs you + + + align:start position:0% +sequence genomes you find paralogs you +find + + align:start position:0% +find + + + align:start position:0% +find +either whole genes or pieces of genes + + align:start position:0% +either whole genes or pieces of genes + + + align:start position:0% +either whole genes or pieces of genes +which have high sequence homology which + + align:start position:0% +which have high sequence homology which + + + align:start position:0% +which have high sequence homology which +we talked about at the beginning of the + + align:start position:0% +we talked about at the beginning of the + + + align:start position:0% +we talked about at the beginning of the +course + + align:start position:0% +course + + + align:start position:0% +course +and here's examples of three + + align:start position:0% +and here's examples of three + + + align:start position:0% +and here's examples of three +protein coding regions encode enzymes + + align:start position:0% +protein coding regions encode enzymes + + + align:start position:0% +protein coding regions encode enzymes +involved in the biosynthesis of amino of + + align:start position:0% +involved in the biosynthesis of amino of + + + align:start position:0% +involved in the biosynthesis of amino of +amino acids + + align:start position:0% +amino acids + + + align:start position:0% +amino acids +so you can imagine that when you grow + + align:start position:0% +so you can imagine that when you grow + + + align:start position:0% +so you can imagine that when you grow +the cells on minimal media + + align:start position:0% +the cells on minimal media + + + align:start position:0% +the cells on minimal media +that you're not so providing the amino + + align:start position:0% +that you're not so providing the amino + + + align:start position:0% +that you're not so providing the amino +acids so the cell has to make the amino + + align:start position:0% +acids so the cell has to make the amino + + + align:start position:0% +acids so the cell has to make the amino +acids if it's if it's got a mutation a + + align:start position:0% +acids if it's if it's got a mutation a + + + align:start position:0% +acids if it's if it's got a mutation a +transposon hit in one of these + + align:start position:0% +transposon hit in one of these + + + align:start position:0% +transposon hit in one of these +genes is key in the biosynthetic + + align:start position:0% +genes is key in the biosynthetic + + + align:start position:0% +genes is key in the biosynthetic +synthesis of lysine threonine or + + align:start position:0% +synthesis of lysine threonine or + + + align:start position:0% +synthesis of lysine threonine or +methionine then you might expect that it + + align:start position:0% +methionine then you might expect that it + + + align:start position:0% +methionine then you might expect that it +won't grow well it will be a selective + + align:start position:0% +won't grow well it will be a selective + + + align:start position:0% +won't grow well it will be a selective +disadvantage of minimal media unless one + + align:start position:0% +disadvantage of minimal media unless one + + + align:start position:0% +disadvantage of minimal media unless one +of the other genes covers for it uh it's + + align:start position:0% +of the other genes covers for it uh it's + + + align:start position:0% +of the other genes covers for it uh it's +possibly green so these have three to + + align:start position:0% +possibly green so these have three to + + + align:start position:0% +possibly green so these have three to +three two or three domains here color + + align:start position:0% +three two or three domains here color + + + align:start position:0% +three two or three domains here color +coded so the green domain + + align:start position:0% +coded so the green domain + + + align:start position:0% +coded so the green domain +is shared by these + + align:start position:0% +is shared by these + + + align:start position:0% +is shared by these +three biosynthetic proteins that are + + align:start position:0% +three biosynthetic proteins that are + + + align:start position:0% +three biosynthetic proteins that are +otherwise very different in their + + align:start position:0% +otherwise very different in their + + + align:start position:0% +otherwise very different in their +metabolic + + align:start position:0% +metabolic + + + align:start position:0% +metabolic +contributions + + align:start position:0% +contributions + + + align:start position:0% +contributions +and you might imagine that some of these + + align:start position:0% +and you might imagine that some of these + + + align:start position:0% +and you might imagine that some of these +green domains might cover for others + + align:start position:0% +green domains might cover for others + + + align:start position:0% +green domains might cover for others +when one of them is mutated + + align:start position:0% +when one of them is mutated + + + align:start position:0% +when one of them is mutated +one of them however the one in life c + + align:start position:0% +one of them however the one in life c + + + align:start position:0% +one of them however the one in life c +when it's got a transposon hit in that + + align:start position:0% +when it's got a transposon hit in that + + + align:start position:0% +when it's got a transposon hit in that +domain + + align:start position:0% +domain + + + align:start position:0% +domain +the replication rate the selective + + align:start position:0% +the replication rate the selective + + + align:start position:0% +the replication rate the selective +disadvantage of mental media is severe + + align:start position:0% +disadvantage of mental media is severe + + + align:start position:0% +disadvantage of mental media is severe +it's a fact it's an order of magnitude + + align:start position:0% +it's a fact it's an order of magnitude + + + align:start position:0% +it's a fact it's an order of magnitude +while the others are more subtle it + + align:start position:0% +while the others are more subtle it + + + align:start position:0% +while the others are more subtle it +could be that the lycee covers for the + + align:start position:0% +could be that the lycee covers for the + + + align:start position:0% +could be that the lycee covers for the +other tube because it's made in large + + align:start position:0% +other tube because it's made in large + + + align:start position:0% +other tube because it's made in large +amounts is very active + + align:start position:0% +amounts is very active + + + align:start position:0% +amounts is very active +but the other two can't cover for the + + align:start position:0% +but the other two can't cover for the + + + align:start position:0% +but the other two can't cover for the +life c + + align:start position:0% +life c + + + align:start position:0% +life c +or there's a variety of other possible + + align:start position:0% +or there's a variety of other possible + + + align:start position:0% +or there's a variety of other possible +explanations for this observation + + align:start position:0% +explanations for this observation + + + align:start position:0% +explanations for this observation +the point is that this generates + + align:start position:0% +the point is that this generates + + + align:start position:0% +the point is that this generates +hypotheses that allow us to follow up on + + align:start position:0% +hypotheses that allow us to follow up on + + + align:start position:0% +hypotheses that allow us to follow up on +the + + align:start position:0% +the + + + align:start position:0% +the +the flux balance or moma + + align:start position:0% +the flux balance or moma + + + align:start position:0% +the flux balance or moma +type of modeling and i think it's what + + align:start position:0% +type of modeling and i think it's what + + + align:start position:0% +type of modeling and i think it's what +the reason i spent so much time on it is + + align:start position:0% +the reason i spent so much time on it is + + + align:start position:0% +the reason i spent so much time on it is +i think the concept of optimization is + + align:start position:0% +i think the concept of optimization is + + + align:start position:0% +i think the concept of optimization is +something that's important both in the + + align:start position:0% +something that's important both in the + + + align:start position:0% +something that's important both in the +sense that we're in engineering as + + align:start position:0% +sense that we're in engineering as + + + align:start position:0% +sense that we're in engineering as +engineers we're optimizing uh living + + align:start position:0% +engineers we're optimizing uh living + + + align:start position:0% +engineers we're optimizing uh living +systems and also as students of + + align:start position:0% +systems and also as students of + + + align:start position:0% +systems and also as students of +evolutionary systems where + + align:start position:0% +evolutionary systems where + + + align:start position:0% +evolutionary systems where +to understand what how those what those + + align:start position:0% +to understand what how those what those + + + align:start position:0% +to understand what how those what those +systems are optimized to do + + align:start position:0% +systems are optimized to do + + + align:start position:0% +systems are optimized to do +we need to + + align:start position:0% +we need to + + + align:start position:0% +we need to +look at + + align:start position:0% +look at + + + align:start position:0% +look at +from this perspective + + align:start position:0% +from this perspective + + + align:start position:0% +from this perspective +so this is just where we what we've + + align:start position:0% +so this is just where we what we've + + + align:start position:0% +so this is just where we what we've +covered today we've covered both + + align:start position:0% +covered today we've covered both + + + align:start position:0% +covered today we've covered both +continuous and discrete + + align:start position:0% +continuous and discrete + + + align:start position:0% +continuous and discrete +uh + + align:start position:0% +uh + + + align:start position:0% +uh +ways of modeling molecular systems + + align:start position:0% +ways of modeling molecular systems + + + align:start position:0% +ways of modeling molecular systems +and in particular the red blood cell and + + align:start position:0% +and in particular the red blood cell and + + + align:start position:0% +and in particular the red blood cell and +the copy number control as a way of of + + align:start position:0% +the copy number control as a way of of + + + align:start position:0% +the copy number control as a way of of +dealing with metabolism and biopolymer + + align:start position:0% +dealing with metabolism and biopolymer + + + align:start position:0% +dealing with metabolism and biopolymer +synthesis separately and the flux + + align:start position:0% +synthesis separately and the flux + + + align:start position:0% +synthesis separately and the flux +balance has brought these together + + align:start position:0% +balance has brought these together + + + align:start position:0% +balance has brought these together +and brought in the notion of + + align:start position:0% +and brought in the notion of + + + align:start position:0% +and brought in the notion of +optimization okay so + + align:start position:0% +optimization okay so + + + align:start position:0% +optimization okay so +until next time \ No newline at end of file diff --git a/eCPASv7NaHk.txt b/eCPASv7NaHk.txt new file mode 100644 index 0000000000000000000000000000000000000000..eaad4367fbf1158be350c734f2616bb3c59b7d2e --- /dev/null +++ b/eCPASv7NaHk.txt @@ -0,0 +1,2724 @@ +The following content is +provided by MIT OpenCourseWare + +under a Creative Commons +license. + +Additional information about +our license and MIT + +OpenCourseWare in general is +available at ocw.MIT.edu. + +PROFESSOR: This, as you know, is +the last lecture of thermal + +tensor properties of crystals +for the semester. + +Come on, can't somebody +go, aww, just to + +make me feel good? + +At least nobody said yay, so +that makes me feel good, too. + +So I guess on balance I come +out feeling pretty happy. + +What I'm going to do today is +to talk a little bit more + +about forthright tensor +properties, which we've not + +said much about. + +And I'm going to look at some +scalar moduli and look at them + +for a couple of different +symmetries and restrictions on + +the compliances. + +The surfaces that you might +expect turn out to be really, + +really weird. + +Because these will be fourth +order variation with the + +direction cosines. + +So when you take trigonometric +functions and raise them to + +the fourth power, you get severe +anisotropies for a + +great many of the +scalar moduli. + +I'm sorry to say, years ago when +I made the acquaintance + +of a computer programmer in +course six who was looking for + +something challenging to do in +connection with material + +science and engineering, +I said, wow, have I got + +something for you. + +How about doing some +computer graphics? + +And this was a few years +ago when such + +products were fairly rare. + +And how about making a program +that would let us see visually + +how some of these scalar +moduli will vary with + +direction and provide the +provision so you can turn them + +over in space, just as you would +pick up a model in your + +hands and rotate it around +till you finally came to + +appreciate it? + +And then for something like a +triclinic crystal, where there + +are almost a couple of dozen +different moduli, how about + +allowing people to scale up or +scale down the value of one of + +the elastic constants +and let them see + +how the shape changes? + +And oh, that was-- he went +to work on it for a + +semester and came back. + +And it was a gorgeous thing. + +You could take a monoclinic +representation of three + +dimensions of Young's modulus. + +Say you want to change S31. + +And it would change +by a factor of 10. + +You'd see a big nose blow out +on the surface and then + +contract down again. + +And you could turn around. + +Anyway, the program having told +you how marvelous it is, + +it's no longer supported because +of the operating + +system that it operated under +having done defunct. + +But anyway, that was a fun +thing to play with. + +AUDIENCE: What operating +system? + +PROFESSOR: I don't even +remember anymore. + +It was a fairly obscure one. + +Was not only the system, but it +worked through a software + +package which operated +on that system. + +All right. + +So we're going to talk today +about fourth rank tensor + +properties. + +The most important-- + +in fact, probably the only ones +you've ever heard of, are + +the elastic, stiffnesses, and +compliances, which are ways of + +representing strain in +terms of stress or + +stress in terms of strain. + +I think I'll sort of see +how the time plays out. + +If I finish just about +everything that I'm hoping to + +say by on the hour, I think I'll +just go an extra five or + +10 minutes. + +And then comes a great, grand, +and traditional event at MIT. + +All semester long I've been +grilling you with problem sets + +and quizzes, and you've had to +dance through your steps just + +because I told you to. + +Now how's this for +reciprocity-- + +you get to evaluate me. + +You get to grade me. + +MIT, at the end of every +semester, has a course + +evaluation. + +It's submitted anonymously by +you, so you could really vent + +your spleen without ever having +called to task for it. + +So when we finish, either for +our break or at the end of a + +slightly extended first session, +I will bow, to + +thunderous applause, +I hope, and exit. + +And then you will be left alone +to fill out the course + +evaluation. + +Corinne will collect them from +you, and she will deliver them + +over to department +headquarters. + +The results will be tabulated, +and so will the comments. + +But they will not be in your +hand, all of which I + +recognize, having spent +hour after hour + +grading your quizzes. + +So they will be submitted +to me in a + +completely sanitized fashion. + +I won't know who said what. + +A final question that I will +answer before you ask it, what + +about the quizzes? + +How are you doing on them? + +Well, I have come +to hate them. + +I think I will give one-question +quizzes from now + +on the future. + +It takes me about five +to seven minutes + +to grade each question. + +And there are about 25 of you. + +So it takes me, to grade one +question, somewhere between + +two and 1/2 and three hours. + +And there are 10 questions +on the two quizzes + +remaining to be graded. + +And so I let you do the +arithmetic, and you can see + +what sort of torment I've been +living in the last few days in + +return for the torment +I put you through + +for two brief hours. + +So wow. + +I will leave it to you to decide +who's getting the worst + +of this deal. + +OK, fourth rank tensors. + +Elasticity's probably the only +one you can think of. + +Let me give you an example in +this handout, an example of + +another forthright +tensor property. + +And this is the piezoresistive +effect, the way electrical + +resistance of the material +changes in response to an + +applied stress. + +It's a pretty exotic property. + +I had never heard of it until +I was at a meeting of the + +American Crystallographic +Association and somebody, + +believe it or not, from +Texas Instruments-- + +so you better bet that this +property is useful in + +technology-- + +fellow named Ahmed Amin got +up and gave a talk on the + +piezoresistive effect. + +And he had marvelous slides at +the outset that defined the + +effect + +So what you have here on these +few sheets is a few pages that + +define the piezoresistance +effect. + +We're not going to do +anything with it. + +It's a fourth rank tensor, so +it will proceed to transform + +like other forthright tensors, +such as elastic stiffness and + +compliance. + +I should warn you about these +following pages, which were + +slides that he used +at his talk. + +He seems to have done the +lettering with a magic marker. + +Because all of the I's and J's +are indistinguishable, which + +makes interpretation of what +he's saying here a little bit + +challenging. + +And then the other thing that +throws one off is that he uses + +x to represent stress. + +I don't know what field or in +what discipline the elements + +of stress are called xij, but +this is what he does. + +And once you figure that out, +the interpretation of what he + +has said here is fairly +apparent if + +you think about it. + +Anyway, he takes a state of +zero stress and strain and + +expands it as a series, and +then picks off different + +coefficients. + +And one of them is a set of +moduli which he calls pi, pi + +subscript ijkl, which relate +stress, xkl in his notation, + +to a change in the density, +delta row ij. + +So here's a fourth rank tensor +property that will indeed have + +to conform to all the +restrictions for the moduli + +that we have defined +for the elastic + +stiffnesses and moduli. + +All right. + +Let me then turn to +stress and strain. + +We introduced the relation +between stress and strain, but + +didn't really go into detail on +the bizarre absorptions of + +factors of two or four that have +to be done in order to + +make this come out in a nice, +clean matrix form. + +So let me remind you of where +these silly factors came in. + +We took our stress tensor, sigma +1 1, sigma 1 2, sigma 1 + +3, 2 1, 2 2, and 2 3, sigma 3 +1, sigma 3 2, and sigma 3 3. + +The tensor had to +be symmetric. + +The off-diagonal term sigma +ij had to be equal to + +the term sigma ij. + +And this was for the reason +of mechanical equilibrium. + +These off-diagonal terms, sigma +ij and sigma ij, we saw, + +exerted a torque on a body. + +And unless they were equal, +the body would undergo an + +angular acceleration. + +And then we renumbered these +according to the convention + +that as we would march down the +diagonal of the tensor and + +take pairs of subscripts, 1 1, +2 2, 3 3, represent them by a + +single 1, 2, and 3, then march +up the side to define a sigma + +4, sigma 5, and a sigma 6. + +If you remember that little +algorithm you can always keep + +straight what these reduced +subscripts represent. + +So with that definition, then, +the stress tensor reduced to + +sigma 1, sigma 6, sigma 5, sigma +6, sigma 2, sigma 4, + +sigma 5, sigma 4, sigma 3. + +And that takes a tensor and +degrades it to a matrix. + +Because there is no law of +transformation for this + +representation of the +elements of stress. + +OK, then we do something very +similar with the strain + +tensor, epsilon 1 1, 1 2, 1 3, +epsilon 2 1, epsilon 2 2, + +epsilon 2 3, epsilon 3 1, +epsilon 3 2, epsilon 3 3. + +And we saw that for physical +reasons this tensor also had + +to be symmetric. + +We had to have epsilon ij +identical to epsilon ji, the + +reason being that if these +off-diagonal shear strains + +were not equal, the state that +we would be defining was one + +of actual deformation combined +with rigid body rotation. + +So unless this was the case, +the definition performed by + +the tensor epsilon iij +would define rigid + +body notation as well. + +OK. + +We use the same process of +renumbering to convert this + +from a tensor to a matrix. + +And we got this into a form, +epsilon 1, epsilon 6, epsilon + +5, epsilon 6, epsilon 2, epsilon +4, epsilon 5, epsilon + +4, epsilon 3. + +But in order to do that, +we saw we had to + +consume a factor of two. + +So there is a factor of +two built into the + +off-diagonal terms. + +And what we have put in here +is we converted this to + +actually epsilon 1, 1/2, epsilon +6, 1/2, epsilon 5. + +And I should have written that +this way to begin with. + +So all these factors of two +appear so that when we combine + +these epsilons we get a nice, +clean matrix relation between + +stress and strain that doesn't +involve factors of two. + +And that's a great convenience +if we're going to be doing all + +of our deformation within +the framework of + +one coordinate system. + +OK. + +So if we now use these +definitions to write the + +stress in terms of strain, we +will set up our fourth rank + +tensor property. + +If we do this first for the +stress in terms of strain, you + +would have a tensor element of +stress sigma 1 1, which would + +be equal to C1 1 1 1 times +epsilon 1 1 plus C1 1 2 2, + +epsilon 2 2 plus C1 1 +3 3, epsilon 3 3. + +And then we would have, in +addition, off-diagonal + +elements of strain. + +We'd have C1 1 2 3 times epsilon +2 3 plus C1 1 3 2 + +times epsilon 3 2 plus C1 1 2 1, +epsilon 2 1 plus C1 1 1 2, + +epsilon 1 2 plus C1 1-- + +and I should have made this 1 +3 so that the other integers + +come out right. + +And C1 1 1 2 times an epsilon 1 +1 1 2 plus a C 1 1 2 1 times + +an epsilon 2 1. + +So that is one line +of the relation + +between stress and strain. + +And when we condense this to a +matrix form, it is surprising, + +once we expand it once more, +at how cumbersome this + +expression is. + +Now, why do I remind +you of all this? + +Isn't it nice to work in the +form of a fixed coordinate + +system where we can use a +matrix for the Cijkl's? + +The answer is, fine, unless +you want to change the + +coordinate system. + +And you might want to do that +for practical reasons such as + +cutting out a specimen which +makes it convenient to define + +the stiffnesses and compliances +relative to a + +coordinate system taken +along the logical + +directions in the specimen. + +And the other reason for doing +it, and that is what I want to + +do a little bit of this +afternoon, is to derive the + +symmetry restrictions on the +stiffnesses and compliances. + +You cannot transform a matrix +representation of the + +stiffness or the compliance. + +You can only do this for the +full-blown tensor arrangement. + +So having collapsed down, which +we'll do momentarily + +just to remind you of how it +goes, we will have to expand + +again to derive symmetry +restrictions. + +Do not exit at this point. + +We're not going to do any of +these calculations in their + +full glory detail. + +We'll just set up the problem +and then jump immediately to + +the outset. + +So how does this pay out if we +try to make the condensation? + +I remind you again that the +symbol C stands for stiffness, + +and the symbol S, which we'll +see later, the Sijkl's are + +call compliances. + +And the perversity of that +semantic description of these + +tensor elements is perverse for +reasons that I have never + +really been able +to understand. + +So if we go down to matrix form, +we'll write instead of + +sigma 1 1, simply sigma 1 1. + +We'll call this C1 1 times +epsilon 1 plus C1 2 + +times epsilon 2. + +So far so good. + +C1 3 times epsilon 3. + +And now we have problems, +because epsilon 2 3 was + +defined as 1/2 of epsilon 5. + +Now we'll have a C1 +5 here, and then a + +C1 3 2 is C1 5 again. + +And this also is 1/2 +of epsilon 5. + +And then similarly, +this is C1-- + +I'm sorry. + +This is C1 4. + +This is C1 5 times 1/2 of +epsilon 5 plus C1 5 times 1/2 + +of epsilon 5 plus C1 6 times +1/2 of epsilon 6 plus C1 6 + +times 1/2 of epsilon 6. + +So this, given the way in which +we had defined matrix + +strain, initially in +connection with + +piezoelectricity when we entered +the realm of third + +rank tensors, this +will play out OK. + +This says that sigma 1 is simply +C1 epsilon 1 plus C1 2 + +times epsilon 2 plus C1 +3 times epsilon 3. + +And now the 1/2 gets absorbed, +and it's simply C1 4 times + +epsilon 4, and so on. + +If we look at another line, one +that involves some of the + +off-diagonal terms and strain, +if we, for example, look at + +sigma 2 3 and we write this down +as sigma 2 3 times 1 1 + +times epsilon 1 1 plus C2 3 2 2 +times epsilon 2 2 plus C2 3 + +3 3 times epsilon 3 3 plus C-- + +and I'll just write down a few +of these additional terms. + +This would be C2 3 3 2 times +epsilon 3 2 plus C2 3 2 3, + +epsilon 2 3, and then other +terms for additional terms, + +and epsilon ij with i not equal +to j, which are going to + +behave the same way. + +So if we convert this, we go +to sigma, and we would call + +this sigma 4. + +This would be C4 1 in matrix +notation times epsilon 1 plus + +C4 2 time epsilon 2 2 plus +C4 3 times epsilon 3. + +And now this matrix element +would be C4 4. + +And in place of the tensor +element of strain epsilon 3 2, + +we would write 1/2 +of epsilon 4. + +And the next term is again a C4 +4 times a 1/2 epsilon 4 and + +the terms in epsilon 5 +and epsilon 6 would + +behave the same way. + +So you can see that the factor +2 is absorbed, and this + +becomes simply C4 4 +times epsilon 4. + +So all the factors of +2 have disappeared. + +And we can say, provided we +remember the way we have + +condensed the elements of tensor +strain, we can say with + +complete confidence that in our +matrix notation, sigma i + +is Cij times epsilon j where i +goes 1, 2, and 3, and j goes + +1, 2, 3 all the way up to six. + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: No. + +No, no, these are the-- + +yeah, I'm sorry. + +Yeah, inj. + +So it's a six by six +matrix, right. + +Right you are. + +And this is a six by six. + +And in here are 36 businesses +stiffnesses. + +OK, any comments other +than, yuck? + +And again, if you stay +in one coordinate + +system it's not so bad. + +In fact, instead of having nine +by nine 81 terms you have + +36 stiffnesses. + +And that's a great +convenience. + +Unfortunately, things are not +quite so simple if we work + +with the compliances represented +by the symbol S. + +And if we attempt to write +strain in terms of stress, + +we'll have an S1 1 1 +1 times sigma 1. + +We'll have an S1 1 2 2 times +sigma 2 2 plus an S1 1 3 3 + +times a sigma 3 3 plus an S1 1 +2 3 times a sigma 2 3 plus an + +S1 1 3 2 times a sigma 3 2, +and an S1 1 2 3 3 1 times + +sigma 3 1 plus an S1 1 3 times +a sigma 1 3, and then other + +off-diagonal terms which I +won't bother to mention. + +So if we convert this to matrix +form, epsilon 1 1 would + +be replaced by the matrix +term epsilon 1. + +S1 1 1 1 would become S1 1, and +this would be sigma 1, and + +an S1 2 times a sigma 2, plus +and S1 3 times sigma 3. + +And now we have a problem, +Houston. + +Because we would have an S1 4 +times a sigma 4 plus an S1 4 + +times sigma 4. + +And now in the sigmas there is +no factor 1/2 in the matrix + +representation of stress as +there was with strain. + +Because we ate the factor +of 2 in defining strain. + +But now there is no factor +of 2 and stress. + +So we're going to have to +do something with that. + +So this would give us some +additional terms, S1 5 times + +sigma 5, and then an S1 5 +times a sigma 5 again. + +So what are we going to do? + +Again, we're stuck. + +We can either say that epsilon +i is equal to Sij times sigma + +j if j is not equal +to 4, 5, or 6. + +Or we can absorb, again, a +factor of 2 in the definition + +of the compliances. + +And that, again, since we will +usually be working in one, and + +the same coordinate system, is +the convenient thing to do. + +So what we will do is +to define this as S1 + +4 times sigma 4. + +And in so doing, we have to +combine the factor of 2 into + +the definition of S1 4. + +So S1 4 would be equal to 1/2 +of S1 1 2 3 plus S1 1 3 2. + +So it's going to be 1/2 of one +of these equal terms that + +involve one on-diagonal +subscript and one + +off-diagonal subscript. + +So this is the only way we're +going to be able to write a + +nice, clean matrix +representation. + +Things get worse. + +AUDIENCE: Sir? + +PROFESSOR: Yes? + +AUDIENCE: You're sure +of your [INAUDIBLE]? + +PROFESSOR: Yeah, this would +be equal to 2S1 4. + +I'm sure it's 1/2. + +I'm not sure of what term +would go in front. + +So I would have 2S1 +4 times sigma 4. + +And if I want to write this-- + +I'm sorry. + +Let me go back to the full +matrix expression. + +I would have S1 1 2 3 times +sigma 2 3 plus S1 1 3 2 + +times sigma 3 2. + +I know that sigma 2 3 is equal +to sigma 3 2, so I could write + +this as S1 1 2 3 plus S1 1 3 2 +just simply times sigma 2 3, + +one of them. + +Now what I would really like to +do is to write this as S1. + +Let's change this to sigma 4. + +I would like to write +this as S1 4. + +So it follows then that +S1 4 is equal to S1 2 + +3 plus S1 1 3 2. + +And that is the other way +around, isn't it? + +Thank you. + +I knew there was a factor of +1/2, but it goes in here. + +AUDIENCE: And then there's +no 2 at all. + +If you wanted to say that S1 1 +2 3 is equal to S, 1 1 3 2, + +then you would have S1 +4 equal to 2S1 1 3 2. + +PROFESSOR: OK, you're +right, you're right. + +So it's this. + +Let's leave it at that. + +But if these are equal, we could +say-- and we did show + +that the compliance tensor is +symmetric, so we could say + +that this is equal to +2S1 1 2 3 or 2S1 1 3 + +2 as they're equal. + +I told you it was going to get +bad, but I didn't think I + +would be contributing to it +the extent that I am. + +I don't know if you really want +to see this, but this + +gets even worse when we deal +with something like epsilon 2 + +3, where this is a term +that would be + +replaced by epsilon 4. + +And then all of our absorbed +factors come back to haunt us. + +Let me go through +this quickly. + +This would be S2 3 1 1 times +sigma 1 1 plus S2 3 2 2 times + +sigma 2 2 plus S2 3 3 +3 times sigma 3 3. + +And then we'll have these terms, +off-diagonal terms S2 3 + +3 1, sigma 3 1 plus S2 3 1 3 +times sigma 1 3, and so on, + +other terms. + +OK, and going from epsilon 2 3 +to epsilon 4, we have to put + +on a factor 1/2. + +And that says that that 1/2 is +going to create problems in + +the first term in +this expansion. + +We'd call this sigma 1 1. + +We'd like to call this S4 1. + +But what is S4 1 from what +we have defined here? + +It's the sum of two +tensor elements. + +So we will have to define, now, +again, S4 1 equals the + +same as we did before. + +It's going to be equal to the +term S2 3 1 1 plus S3 2 1 1 1. + +And therefore if I put a 1/2 in +this definition, then that + +will cancel, so far. + +But then in the terms that +come down in the lower + +quadrant of the matrix-- + +and I will just right +in two terms. + +We've got an S2 3 31 that +we would write as S4 + +4 times sigma 4. + +And then I would have another +term, S4 4 times sigma 4. + +But the S4 4 really is a sum +of two tensor elements. + +So my definition of an S4 +4 is that it should be-- + +AUDIENCE: Isn't that sigma +5 [INAUDIBLE]? + +PROFESSOR: You're right, +you're right. + +Yeah, this is 5. + +So this was right, 3 1, +and this is sigma 5. + +You're right. + +And I go to S4 5, yeah. + +No, sigma-- + +OK, yeah. + +OK, let me cut to the chase. + +What we're going to have to do +is to put in not the factor + +1/2 that we had here, +but there's going to + +be a factor 4 that-- + +something like S-- + +which one are we dealing with? + +Things like S2 3 3 1, +something like S4-- + +and we're dealing with 5. + +S4 5 is going to be defined as +S1, S2 3 1 3 plus S2 3 3 1 + +plus S3 2 1 3 plus S3 2 3 1. + +So we're going to have to put in +a factor of 1/4 in front of + +the S4 5 in order to accommodate +for those terms. + +So our definition, then, in +going from tensor compliances + +to matrix compliances is +much more complicated. + +And the rule-- and just to +summarize this, I gave you a + +handout last time. + +The necessary conventions to +absorb these factors of 2 and + +4 is that-- + +and I didn't bring it with me. + +OK, I just simply did not +bring it with me. + +So I wouldn't attempt +to summarize it. + +All right. + +So hopefully I've convinced you +of nothing other than that + +these conversions are messy. + +But the summary is that for the +compliances, the Sijkl, + +you take this equal to +Slm if l and m are + +equal to 1, 2, or 3. + +Then you have to replace Sijkl +by 1/2 of Slm if i, j, or kl + +is 4, 5, or 6. + +And then you have to write Sijkl +as 1/4 of Slm if i, j, + +and kl are 4, 5, or 6. + +But once you're into the +coordinate system, which will + +be fixed in matrix notation, +things are simple, since you + +don't have to worry about +these factors of 2 or 3. + +The reason I did this is I +would like to now talk a + +little bit about how one can +define important scalar moduli + +that describe a particular +phenomenon. + +If you ask the question, how do +mechanical properties vary + +with direction, we've got six +unique elements of stress. + +And we've got six independent +elements of + +strain that can work. + +And if you wanted to show how +each one of those elements + +varied with the other +one, you'd need 36-- + +6 times 6, 36-- + +representation surfaces +and this is + +not going to be fruitful. + +So just as we did for +piezoelectricity where we + +could define a scalar modulus +which represented the + +component of polarization normal +to a very thin plate-- + +making it a thin plate means +you're going to measure + +primarily the charge on the +large surface, because + +polarization is charge +per unit area. + +So if you looked at the surface +of a plate with x1 + +normal to the plate, you are +going to have a specimen that + +primarily gives you a measure +of P1, or the charge on a + +surface normal to x1. + +And then you could apply any +of six different states of + +simple stress. + +And one thing that you could +do is squeeze it with the + +tensile stress in the same +direction as the + +normal to the surface. + +And that was the longitudinal +piezoelectric modulus. + +Then on the quiz you looked at +another modulus that related a + +component of polarization on +another surface in response to + +a tensile stress that was +not parallel to it. + +There are a number of such +moduli and mechanical + +properties. + +Probably the most important +one is something called + +Young's modulus, which I'm +sure you've all heard of. + +And Young's modulus involves +taking a very long rod of the + +material and hanging +a weight on it. + +And that weight will +induce a strain. + +And if we take this as the +direction of x1, we will, with + +Young's modulus, relate the +change of length to the + +initial length of the rod. + +And my question now is, +rhetorically, do we want to do + +this in terms of stiffnesses +or compliances? + +Does it make any difference? + +Yeah, makes a lot of difference +in terms of the + +simplicity of the result +that you get. + +Suppose we wanted to do this in +terms of the compliances. + +What we'd be then applying +would be a sigma 1. + +And this would be given +by the compliance C1 1 + +times the strain E1. + +That looks like exactly +what we want. + +This delta l over l for this +one-dimensional specimen with + +a one-dimensional directional +applied stress, this would be + +simply epsilon 1. + +And that's force per +unit area here. + +This would be sigma 1 1. + +And it looks as though what we +want is a C1 1 1 that relates + +a sigma 1 1 to an epsilon 1 1. + +Is this going to be a definition +that I would want + +to make for describing this? + +My colleague here shakes his +head very seriously. + +No. + +Do you want to share +your reservation? + +AUDIENCE: Because as I recall, +Young's modulus, once strain + +is weaker output [INAUDIBLE] +in terms of stress you're + +going to want a compliance. + +PROFESSOR: That's one answer. + +AUDIENCE: You could +theoretically get either one + +[INAUDIBLE]. + +PROFESSOR: If I could restate +your objection, we can't + +impose a strain to +get a stress. + +We really stresses the +independent variable, + +practically speaking. + +We can stress it, but we can't +instantly say, [INAUDIBLE] + +develop a epsilon 1. + +Yeah? + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: You betcha. + +That's the reason. + +Added onto this is not only this +term, but there will be a + +C1 2 times epsilon 2 plus +a C1 3 times an + +epsilon 3, and so on. + +So we're not going to be able +to get a nice, tidy relation + +between the tensile strain that +we're measuring and the + +tensile uniaxial stress that +is produced there. + +So the relation of stress in +terms of strain that involves + +the stiffnesses is just +not going to work. + +But if we would instead express +epsilon1 in terms of a + +compliance, a matrix compliance +S1 1 times sigma 1, + +that's all that she wrote. + +We're measuring this by design +by selecting an elongated + +specimen for which we'll +primarily be seeing epsilon 1. + +This is not to say these +other strains exist. + +There will be lateral strains +here that will be epsilon 2 + +and epsilon 3. + +There will be shear strains. + +Sounds mind-boggling. + +You pull the sample in +this direction, and + +what it does is shear. + +Well, if this were a single +crystal, that would happen. + +And these would be other +components of deformation. + +But if we measure a pi sigma 1 +and measure epsilon 1, then + +this is the way we have +to define it. + +And the definition of Young's +modulus is that 1 over S1 1 is + +sigma 1 over epsilon 1. + +And this is Young's modulus. + +I would hasten to observe that +it is unfortunate that this + +very practical modulus involves +the S's, which have + +all these complicated +factors of 2 and 4. + +And therefore, if we try to go +to a particular symmetry and + +ask the question, how does +Young's modulus change as we + +cut this rod in different +orientations + +from the single crystal. + +So I would like to illustrate +for you how we would do this. + +I'm going to take a very, +very simple example. + +If you look in the table of +symmetry restrictions that I + +passed out a couple of times +ago, prior to the quiz, for an + +isotropic the tensor has a +different form than it does + +for a cubic crystal. + +Cubic crystals are elastically +anisotropic. + +But the form of the stiffness +tensor for an isotropic + +material was S1 1, S1 2, +S1 2, 0, 0, 0, S1 2, S1 + +1, S1 2, 0, 0, 0. + +Then the diagonal terms, if the +material was isotropic, + +was 2s1 1 minus S1 2 for this +term, 0, 0, 0, 0, 0, 0, and + +again, a 2S1 1 minus S1 2 plus +a 0, and then 0, 0, 0, 0, 2S1 + +1 minus S1 2. + +OK. + +Let me now derive Young's +modulus as a function of + +direction and show that, +in fact, this says that + +regardless how you orient the +rod, the value of Young's + +modulus will stay the same. + +Let me also do something else +first, though, which is + +something we should have +scratched our head over when + +we first encountered it. + +Here's something curious. + +When we looked at symmetry +constraints on single + +crystals, we found that for a +cubic crystal, C6 6 had to be + +equal to 1/2 of C1 1 minus C1 +2 if the stiffnesses were to + +be independent for all symmetry +transformations. + +For the compliances, however, +we found that S6 6 had to be + +equal to 2 times S1 +1 minus S1 2. + +Two very different equalities +between tensor elements to + +make the elastic behavior be +invariant to the symmetry + +transformations of +a cubic crystal. + +How come? + +How come these are +so different? + +Well, they have to be, in terms +of the tensor, the same + +sort of a quality. + +And the reason they don't look +the same is because of our + +different absorption of the +factors of 2 and 4 in defining + +the stiffnesses an in defining +the compliances. + +Remember that for the Cijkl's +there was no factor of 2 or 4 + +introduced in defining +the matrix elements. + +So this one is OK. + +This is a true equality between +tensor elements, for + +any tensor whatsoever of fourth + +rank for a cubic crystal. + +For these terms, these +are off-diagonal. + +This is an off-diagonal +compliance. + +And our definition is that Sijkl +is equal to Smn, for m + +and n not equal to 4, 5, or 6. + +Here's this crazy thing again. + +It's equal to 1/2 of Smn for +m or n equal to 4, 5, or 6. + +And it's equal to 1/4 +of Smn for m and n + +equal to 4, 5, or 6. + +So S6 6 here is actually +4S1 2 1 2. + +And that's supposedly equal to +2S1 1, which is really S1 1 1, + +minus S1 1 2 2. + +And this says that 1/2 of S1 +2 1 2 is equal to S1 1 1 1 + +minus S1 1 2 2. + +So this is exactly the same +constraint on tensor elements, + +when we take out these +factors of 2 and 4 + +that have been absorbed. + +So this, in fact, although it +looks very different with + +those factors absorbed, is +exactly this same relation. + +So the symmetry constraint +is the same. + +AUDIENCE: How'd you +get 1/2 there? + +PROFESSOR: Hmm? + +How did I get 1/2 here? + +It's 4S1 2 2 had to be equal +to 2S1 1 minus S1 2. + +And this was the equality. + +I'm working up this way. + +So this was the statement in +the matrix forms of the + +compliances that I handed out. + +Looks different from the +term on the left. + +So I wrote this now in terms +of the matrix elements. + +And the factor of +4 comes in here. + +The 2 was here in the equality +that had to be held that the + +tensors stay invariant. + +And if I bring this 2 over on +the left-hand side, it's + +exactly the same as when-- + +AUDIENCE: Shouldn't +it be 2 now? + +[INAUDIBLE]. + +[INAUDIBLE] the right side. + +PROFESSOR: No, this is just +replacement of the matrix + +terms with the definition +of the tensor. + +AUDIENCE: Right, but +[INAUDIBLE]. + +AUDIENCE: You're just dividing +4 by 2, right? + +PROFESSOR: Yeah, exactly. + +AUDIENCE: So wouldn't that +make [INAUDIBLE]? + +PROFESSOR: Oh, ha, OK. + +AUDIENCE: You want to be able +to [INAUDIBLE] by 4, so it'd + +be S12 1 2 equals 1/2 +the difference + +to be equal to that. + +PROFESSOR: OK, OK. + +Thank you. + +OK, let me then go back to +what I started out to do. + +And I will write just one line +of how we would go about + +expanding this just to indicate +how intricate it is, + +and then I'll give a few +examples for two point groups + +of how Young's modulus varies +with direction. + +OK. + +What we're going to say, then, +is that one of these + +compliances, S1 1 1 1 prime is +going to be equal to l 1/4 + +times S1 1 1 1 plus l 2/4 times +S2 2 2 2 plus l 3/4 + +times S3 3 3 3 . + +And just now doing what we know, +that any Sijkl prime is + +going to be Cii, Cj capital J, +Ck capital K, Cl capital L-- + +these are direction cosines +now, not stiffnesses-- + +times Sijkl. + +So it's a quadrupole summation +over all of the non-zero + +tensor elements. + +So what I'm doing now is +taking these terms and + +expanding them to the +full tensor form. + +So S1 1 1 1 prime, that's +the first term in + +the transformed tensor. + +That's going to be these terms +plus l1l2 squared times S1 1 2 + +2 plus S2 2 1 1 plus l1 squared +l3 squared times S1 1 + +3 3 plus S3 3 1 1, and then +still another term, l2 squared + +l3 squared times S2 2 +3 3 plus S3 3 2 2. + +And then there will be terms +of the form l2 squared l3 + +squared times, again, four +terms, S3 2 3 2 plus S1 2 3 3 + +plus S2 3 3 2 plus S2 3 2 3, and +then similarly, terms in + +the squares of l1 and l2, and +these would involve four terms + +of the form S1 2 1 2 plus +permutation 0, and then l1 + +squared l3 squared times, again, +four terms, S1 3 1 3 + +and permutation 0 +for four terms. + +OK. + +So what do we have now? + +We have an expression +for S1 1 1 1 prime. + +And this is, in fact, 1 over +Young's modulus E. And we've + +done this summation over the +supposed non-zero tensor + +elements in the matrix for +an isotropic material. + +And if I simplify this, and +this will be just one more + +tedious and then we can see, +that is for these equalities, + +we ought to, for l1, l2, l3, +get the same value, S1 1. + +And that is indeed +what happens. + +So the summation, if I simplify, +is l 1/4 times S1 1 + +plus l 2.4 times S2 2 plus +l 3/4 times S3 3. + +And then a collection of terms +plus l1 squared l2 squared, S1 + +2 plus S2 1. + +And then similar terms in l1 and +l3, l1 squared l3 squared, + +S1 3 plus S 3 1 plus l2 squared +l3 squared times + +S2 3 plus S3 2. + +And then some terms that stand +by themselves, l2 squared l3 + +squared times S4 4 plus l1 +squared l2 squared S6 6 plus + +l1 squared plus l3 squared +times S5 5. + +And consolidating this, this is +going to be equal to l 1/4 + +plus l 2/4 plus l +3/4 times S1 1. + +And then combining terms in the +second power of direction + +cosines, l1 squared l2 squared +plus l1 squared l3 squared + +plus l2 squared l3 squared. + +And this is all times 2S1 2 +plus 2S1 1 minus 2S1 2. + +So S1 2 drops out. + +And all this will be simply l +1/4 plus l 2/4 plus l 3/4. + +And then I'll add in the other +terms here that involve + +products of squares of +direction cosines. + +And all this is times S1 1. + +But this turns out to be equal +to simply l1 squared plus l2 + +squared plus l3 squared, the +sum of the squares of the + +direction cosines of our rod, +quantity squared times S1 1. + +And this term inside the +parentheses is 1. + +So indeed, S1 1 prime +is equal to S1 1. + +So the value of Young's modulus +has not changed with + +direction if the form of the +compliance tensor is like so. + +And I think you would probably +have taken my word for that, + +but it was intended primarily as +an example of how, when S1 + +1 prime is the reciprocal of +Young's modulus, how you would + +set up a transformation +for S1 1 prime. + +And the form of this polynomial +would be exactly + +the same, even for a triclinic +crystal, if you included all + +the non-zero terms +in this fashion. + +All right, so let me wrap things +up in another couple + +minutes for some cases that +are real symmetries, where + +Young's modulus is +anisotropic. + +And working in exactly the same +way for the tensor that + +is the appropriate one for a +cubic crystal, we would lift + +out the form of the +stiffness matrix. + +The reciprocal of Young's +modulus is S1 1 prime, so what + +we're saying is we have +a long, skinny rod. + +This is x1. + +And what we're doing, if this +is a single crystal, is + +examining how Young's modulus +changes as we change the + +direction of the rod to a new +orientation, x1 prime, that's + +described by direction cosines +l1, l2, L3, relative to x1. + +The expression that results by +exactly the process that we + +muddled through a moment ago is +that for a cubic crystal, + +the form of S1 1 prime as a +function of direction does + +indeed give anisotropy. + +Isaiah It's S1 1 minus 2 +times S1 1 minus S1 2 + +minus 1/2 of S4 4. + +Remember, for a cubic crystal, 1 +1, 2 2, and 1 4 are the only + +non-zero terms. + +And then this is times a +polynomial l1 squared l2 + +squared plus l2 squared +l3 squared plus + +l3 squared l1 squared. + +So this is, again the reciprocal +of Young's modulus. + +And it turns out to have a +constant term, S1 1 , which is + +what we found for the +isotropic material. + +But from that, as the direction +cosines change, we + +subtract off a term that is a +linear combination of 1 1, 1 + +2, and 4 4. + +So the question is, is this +positive or negative? + +The direction cosines are all +squared, so this term here is + +always going to be positive. + +So are we going to take the +thing that we found for an + +isotropic material, which was +a constant, Young's modulus, + +which was 1 over S1 1 prime, +and that's equal to the + +Young's modulus E. + +Are we going to add or subtract +something to it? + +Well, it turns out that if you +look at real materials, it can + +be either positive +or negative. + +It's usually positive. + +So that says we are going to +subtract off a term which goes + +as products of squares +of direction cosines. + +And this is something that's +going to be zero along the + +direction 1 0 0. + +So along the reference axes +x1, x2, x3, which if you + +remember, where this form of +the matrix came from was + +taking the axes along the edges +of the cubic crystal. + +It turns out that this is going +to be equal to 1/3 along + +the direction 1 1 1. + +So if this term is plus, nothing +gets added onto the + +surface in the directions that +correspond to the four-fold + +axes or the twofold axes +of a cubic crystal. + +Nothing gets added +on if it's plus. + +But along the body diagonals, +this takes on a value of 1 3, + +so a positive thing +gets added on. + +And the best way I can describe +this surface-- it's + +not a simple surface-- + +it looks like a cube +with fuzzy edges. + +So we had a cube and started +to dissolve it. + +So this is how the reciprocal +of Young's + +modulus varies with direction. + +If, on the other hand, this +term is negative-- + +so this is what you get +if it's positive. + +If it's negative, again, you +start with the basic isotropic + +variation of 1 over S1 1 1. + +If it is negative, and there's +one metal, that's molybdenum-- + +molybdenum has a negative value +of these compliances. + +It looks like a surface that has +indentations along the 1 1 + +1 direction. + +So it looks like something +with a dimple in it. + +There is a final case, which +is not realized for any + +material that I know +of, if that term is + +0, then it's isotropic. + +Let me give you one other +variation that comes straight + +out of [INAUDIBLE]. + +And this is for a hexagonal +crystal that might be a + +hexagonal close-packed +crystal. + +For zinc specifically, which +is a hexagonal close-packed + +metal, the form of the matrix is +S1 1, S1 2, S1 3, 0, 0, 0, + +S1 1, S1 2, 0, 0, 0, S3 3, +0, 0, 0, S4 4, 0, 0, S4 + +4, 0, and S4 4. + +In the values of these specific +compliances are 8.4 + +for S1 1, for S1 2 1.1, for S1 +3, minus 7.8, for S3 3, 28.7, + +for S4 4, 26.4. + +And these are all in units of +10 to the minus 12 meters + +squared per Newton. + +That's good old MKS units. + +It turns out that there are 10 +to the 2 meters squared per + +Newton per 1 centimeter +squared per dyne, if + +you like CGS units. + +The form of the reciprocal of +Young's modulus, it turns out + +to be a surface of revolution. + +This is x3, which is the +direction of C. And that's the + +surface of revolution and the +value of S1 1 prime as a + +function of the angle theta. + +That's the only parameter we +need examine the variation + +with since it's a surface +of revolution. + +S1 1 prime is equal to S1 1 +times the sine of theta to the + +fourth power plus S3 3 times +the cosine of theta to the + +fourth power plus S4 4 plus +2S1 3 times sine squared + +theta, cosine squared theta. + +So it's a fairly exotic surface, +even as a surface of + +revolution. + +And what this looks like, it's +something that peaks out at 3 + +times 10 to the minus 12 +centimeters squared per dyne + +along the direction of C. It's +something that comes down very + +sharply as you approach the +normal to the C axis. + +And then there's a cute little +wiggle just near the axis. + +So it looks something +like that. + +Not a terribly isotropic +surface, and a variation of + +Young's modulus of 3 to 1 in +the direction parallel to C + +and perpendicular to C. So +there are lots of exotic + +surfaces of this sort. + +All right. + +I did run a little bit over. + +And I will absent myself and +let you express yourself + +candidly on the questionnaire. + +Except for these numbers that +I just put up on the + +blackboard, I haven't really +said anything about, much + +about, numbers. + +So let me pass around some +examples, not for metals, + +which we just looked +at, but for oxides. + +And this is interesting, because +you'll remember there + +was an additional equality +between the stiffnesses called + +the [? Kowshi ?] + +equality, which was supposed to +hold for physical reasons, + +not for reasons of symmetry, if +the forces were central, if + +the crystal was under a state +of no stress, and if all of + +the atoms were situated at +a center of symmetry. + +The first set of data that you +have on the top sheet is for + +MGO, which is cubic. + +It's predominantly +ionic compounds. + +And the atoms are all +octahedrally coordinated. + +So all of the requirements +for the [? Kowshi ?] + +equality should hold. + +And you can see they're +not really exact. + +And that's probably due to +the covalent character. + +The two different sets of data +here are for measurements by + +two separate observers. + +The second page is for +aluminum oxide. + +And again, you see the order of +magnitudes of the numbers + +on the order of 10 to the 12 +dynes per centimeter squared + +in general, and variation from +one to another for a lumen of + +a factor of about four. + +I meant to bring the book in, +but I left it behind in my + +rush to come off. + +Where do you get +these numbers? + +And it's hard to really find. + +And the book from which I took +these data are by two workers, + +Simmons and Wang. + +And it's called Handbook +of Elastic Constants, + +I think that is. + +And this is a book that was +published by MIT Press. + +Valuable repository of data, +but it's all numbers. + +And there are many, many +materials in here. + +Simmons and Wang, interestingly, +are + +geophysicists. + +Why should geophysicists +care about stiffnesses? + +Why? + +Because these guys are going all +over the face of the earth + +setting off little bits of +explosive that send off + +seismic waves. + +And they probed the interior +of the earth by the + +propagation of elastic waves. + +And the elastic waves depend +on the square root of + +stiffnesses over the density +of the material. + +So they're very, very interested +in the elastic + +properties of particularly +rock-forming minerals. + +Another interesting comment on +this book is that there is no + +set of data for a single +triclinic crystal. + +Too many stiffnesses that are +independent, I guess, and too + +few materials that, fortunately, +are anisotropic + +and triclinic. + +OK, I am going to quit. + +And thank you for +your attention. + +You've been a good class. + +And we've covered all sorts of +exotic aspects of the behavior + +of crystalline materials. + +And you might think with some +justification that you know + +all there is to know about +symmetry and tensor properties + +of materials. + +But nevertheless, I would +caution you that you don't + +know everything. + +So I have a final handout fill +in the chinks, the cracks that + +we've not been able to fill. + +And this is a set of data that +is titled "Think You Know + +Everything?" And this will fill +in some things that you + +really don't know. + +And it has a lot of very +useful items on here. + +For example, there are +293 different ways to + +make change for $1. + +You didn't know that. + +2/3 of the world's eggplant +is grown in New Jersey. + +I'm a native of New Jersey, and +even I didn't know that. + +The longest one-syllable word +in the English language is + +"screeched." OK. + +And so it goes. + +In most advertisements-- + +this is one I never checked +out-- in most advertisements + +the time displayed on a watch +is 10 minutes after 10:00. + +Don't know why. + +How many ridges are around +the edge of a dime? + +118. + +And how many little dimples +are there on a + +regulation golf ball? + +If you count them up, you'll +find that there are 336. + +So I'll end with one for the +benefit of some of our + +visiting students. + +In England, the Speaker of the +House is not allowed to speak. + +There is my oxymoron +of the day. + +And with that I shall +leave you, and I + +hope you enjoy these. + +It's one of these things +that circulates + +around on the internet. + +So as the sheet finishes, now +you do know everything. + +So I'll leave you, and again I +thank you for your faithful + +attendance. + +And you shall see me when you +come to call for your quizzes. + +And I will, as most of you +requested, send out an email + +to let you know when you can +come and pick those up. + +So again, thank you. + +Enjoy the mid-term break. + +And take advantage of some of +the really interesting things + +that go on extracurricularly +around the institute. + +So that's it. + +Thank you, and au revoir. + +[APPLAUSE] \ No newline at end of file diff --git a/feb9j65Iz4w.txt b/feb9j65Iz4w.txt new file mode 100644 index 0000000000000000000000000000000000000000..10f82c210bbac28f33d6b0479de8d6b8674becaf --- /dev/null +++ b/feb9j65Iz4w.txt @@ -0,0 +1,6491 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT OpenCourseWare continue to + + align:start position:0% +will help MIT OpenCourseWare continue to + + + align:start position:0% +will help MIT OpenCourseWare continue to +offer high quality educational resources + + align:start position:0% +offer high quality educational resources + + + align:start position:0% +offer high quality educational resources +for free + + align:start position:0% +for free + + + align:start position:0% +for free +to make a donation or to view additional + + align:start position:0% +to make a donation or to view additional + + + align:start position:0% +to make a donation or to view additional +materials from hundreds of MIT courses + + align:start position:0% +materials from hundreds of MIT courses + + + align:start position:0% +materials from hundreds of MIT courses +visit MIT opencourseware at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +okay let me just say our next topic + + align:start position:0% +okay let me just say our next topic + + + align:start position:0% +okay let me just say our next topic +moving really toward machine learning + + align:start position:0% +moving really toward machine learning + + + align:start position:0% +moving really toward machine learning +would be the last section of section of + + align:start position:0% +would be the last section of section of + + + align:start position:0% +would be the last section of section of +chapter six about stochastic gradient + + align:start position:0% +chapter six about stochastic gradient + + + align:start position:0% +chapter six about stochastic gradient +descent I think professor sois from + + align:start position:0% +descent I think professor sois from + + + align:start position:0% +descent I think professor sois from +computer science is if he's able he will + + align:start position:0% +computer science is if he's able he will + + + align:start position:0% +computer science is if he's able he will +take the class Friday and tell us about + + align:start position:0% +take the class Friday and tell us about + + + align:start position:0% +take the class Friday and tell us about +STDs stochastic gradient descent + + align:start position:0% +STDs stochastic gradient descent + + + align:start position:0% +STDs stochastic gradient descent +critical algorithm I mean that at a + + align:start position:0% +critical algorithm I mean that at a + + + align:start position:0% +critical algorithm I mean that at a +quick look + + align:start position:0% +quick look + + + align:start position:0% +quick look +stochastic gradient descent is does + + align:start position:0% +stochastic gradient descent is does + + + align:start position:0% +stochastic gradient descent is does +smaller batches at a time so it's + + align:start position:0% +smaller batches at a time so it's + + + align:start position:0% +smaller batches at a time so it's +computationally faster than pure + + align:start position:0% +computationally faster than pure + + + align:start position:0% +computationally faster than pure +gradient descent but also stochastic + + align:start position:0% +gradient descent but also stochastic + + + align:start position:0% +gradient descent but also stochastic +gradient descent is able to solve + + align:start position:0% +gradient descent is able to solve + + + align:start position:0% +gradient descent is able to solve +probabilistic problems where you're + + align:start position:0% +probabilistic problems where you're + + + align:start position:0% +probabilistic problems where you're +trying to minimize an expected value + + align:start position:0% +trying to minimize an expected value + + + align:start position:0% +trying to minimize an expected value +instead of a function anyway it's a + + align:start position:0% +instead of a function anyway it's a + + + align:start position:0% +instead of a function anyway it's a +important thing actually there's a + + align:start position:0% +important thing actually there's a + + + align:start position:0% +important thing actually there's a +lecture at two o'clock in brain in + + align:start position:0% +lecture at two o'clock in brain in + + + align:start position:0% +lecture at two o'clock in brain in +neuroscience about the gradient descent + + align:start position:0% +neuroscience about the gradient descent + + + align:start position:0% +neuroscience about the gradient descent +algorithms and then professor Boyd is + + align:start position:0% +algorithms and then professor Boyd is + + + align:start position:0% +algorithms and then professor Boyd is +speaking here at 4:30 this afternoon + + align:start position:0% +speaking here at 4:30 this afternoon + + + align:start position:0% +speaking here at 4:30 this afternoon +it's overwhelming so so I'm going to + + align:start position:0% +it's overwhelming so so I'm going to + + + align:start position:0% +it's overwhelming so so I'm going to +talk today about several topics that are + + align:start position:0% +talk today about several topics that are + + + align:start position:0% +talk today about several topics that are +specific parts of optimization linear + + align:start position:0% +specific parts of optimization linear + + + align:start position:0% +specific parts of optimization linear +programming is a very famous part of + + align:start position:0% +programming is a very famous part of + + + align:start position:0% +programming is a very famous part of +optimization I don't know if you've met + + align:start position:0% +optimization I don't know if you've met + + + align:start position:0% +optimization I don't know if you've met +it I think it's worth knowing that what + + align:start position:0% +it I think it's worth knowing that what + + + align:start position:0% +it I think it's worth knowing that what +the inputs are and what's the key fact + + align:start position:0% +the inputs are and what's the key fact + + + align:start position:0% +the inputs are and what's the key fact +about linear programming and of course + + align:start position:0% +about linear programming and of course + + + align:start position:0% +about linear programming and of course +also what are the algorithms that's + + align:start position:0% +also what are the algorithms that's + + + align:start position:0% +also what are the algorithms that's +usually what we want to know what's the + + align:start position:0% +usually what we want to know what's the + + + align:start position:0% +usually what we want to know what's the +problem what are the results the + + align:start position:0% +problem what are the results the + + + align:start position:0% +problem what are the results the +mathematical results and what are the + + align:start position:0% +mathematical results and what are the + + + align:start position:0% +mathematical results and what are the +computational tools yeah so that's a + + align:start position:0% +computational tools yeah so that's a + + + align:start position:0% +computational tools yeah so that's a +very established max-flow min-cut is + + align:start position:0% +very established max-flow min-cut is + + + align:start position:0% +very established max-flow min-cut is +once + + align:start position:0% +once + + + align:start position:0% +once +specifically linear programming that I + + align:start position:0% +specifically linear programming that I + + + align:start position:0% +specifically linear programming that I +think maybe would serve as the best + + align:start position:0% +think maybe would serve as the best + + + align:start position:0% +think maybe would serve as the best +example and then two-person games + + align:start position:0% +example and then two-person games + + + align:start position:0% +example and then two-person games +have you met those do so would you know + + align:start position:0% +have you met those do so would you know + + + align:start position:0% +have you met those do so would you know +what what the rules are at a two-person + + align:start position:0% +what what the rules are at a two-person + + + align:start position:0% +what what the rules are at a two-person +zero-sum game those are the in game + + align:start position:0% +zero-sum game those are the in game + + + align:start position:0% +zero-sum game those are the in game +theory those are the ones that are clear + + align:start position:0% +theory those are the ones that are clear + + + align:start position:0% +theory those are the ones that are clear +everything's well established there and + + align:start position:0% +everything's well established there and + + + align:start position:0% +everything's well established there and +in fact they're equivalent to or linear + + align:start position:0% +in fact they're equivalent to or linear + + + align:start position:0% +in fact they're equivalent to or linear +programs so that's why those two are + + align:start position:0% +programs so that's why those two are + + + align:start position:0% +programs so that's why those two are +coming in today and then the key fact + + align:start position:0% +coming in today and then the key fact + + + align:start position:0% +coming in today and then the key fact +about two-person games and about linear + + align:start position:0% +about two-person games and about linear + + + align:start position:0% +about two-person games and about linear +programming is duality so if there's any + + align:start position:0% +programming is duality so if there's any + + + align:start position:0% +programming is duality so if there's any +word on that board it's the one in + + align:start position:0% +word on that board it's the one in + + + align:start position:0% +word on that board it's the one in +capital letters that has mass content + + align:start position:0% +capital letters that has mass content + + + align:start position:0% +capital letters that has mass content +okay I'm just going to start with linear + + align:start position:0% +okay I'm just going to start with linear + + + align:start position:0% +okay I'm just going to start with linear +program and then move on okay so what's + + align:start position:0% +program and then move on okay so what's + + + align:start position:0% +program and then move on okay so what's +a linear programming linear program it's + + align:start position:0% +a linear programming linear program it's + + + align:start position:0% +a linear programming linear program it's +we're optimizing a linear cost function + + align:start position:0% +we're optimizing a linear cost function + + + align:start position:0% +we're optimizing a linear cost function +so we're a minute minimizing the cost C + + align:start position:0% +so we're a minute minimizing the cost C + + + align:start position:0% +so we're a minute minimizing the cost C +transpose X so that vector X is the + + align:start position:0% +transpose X so that vector X is the + + + align:start position:0% +transpose X so that vector X is the +unknown that we're looking for and this + + align:start position:0% +unknown that we're looking for and this + + + align:start position:0% +unknown that we're looking for and this +vector C is the cost vector so that is + + align:start position:0% +vector C is the cost vector so that is + + + align:start position:0% +vector C is the cost vector so that is +c1 x1 plus plus CN xn so you can see why + + align:start position:0% +c1 x1 plus plus CN xn so you can see why + + + align:start position:0% +c1 x1 plus plus CN xn so you can see why +it's called linear programming + + align:start position:0% +it's called linear programming + + + align:start position:0% +it's called linear programming +the cost is linear the constraints are + + align:start position:0% +the cost is linear the constraints are + + + align:start position:0% +the cost is linear the constraints are +also linear so the constraints on X are + + align:start position:0% +also linear so the constraints on X are + + + align:start position:0% +also linear so the constraints on X are +set of linear equations of course I'm + + align:start position:0% +set of linear equations of course I'm + + + align:start position:0% +set of linear equations of course I'm +not thinking of a as being a square + + align:start position:0% +not thinking of a as being a square + + + align:start position:0% +not thinking of a as being a square +invertible matrix no way if it were that + + align:start position:0% +invertible matrix no way if it were that + + + align:start position:0% +invertible matrix no way if it were that +would tell us what X had to be and we + + align:start position:0% +would tell us what X had to be and we + + + align:start position:0% +would tell us what X had to be and we +our problem would be over we we have we + + align:start position:0% +our problem would be over we we have we + + + align:start position:0% +our problem would be over we we have we +have n unknowns this is M by n of course + + align:start position:0% +have n unknowns this is M by n of course + + + align:start position:0% +have n unknowns this is M by n of course +X is n by 1 that's our unknown vector + + align:start position:0% +X is n by 1 that's our unknown vector + + + align:start position:0% +X is n by 1 that's our unknown vector +and I'm thinking that M will be smaller + + align:start position:0% +and I'm thinking that M will be smaller + + + align:start position:0% +and I'm thinking that M will be smaller +than n but we do have constraints and + + align:start position:0% +than n but we do have constraints and + + + align:start position:0% +than n but we do have constraints and +now comes the thing that makes linear + + align:start position:0% +now comes the thing that makes linear + + + align:start position:0% +now comes the thing that makes linear +programming not not actually linear and + + align:start position:0% +programming not not actually linear and + + + align:start position:0% +programming not not actually linear and +that's the constraint X greater equal + + align:start position:0% +that's the constraint X greater equal + + + align:start position:0% +that's the constraint X greater equal +zero and I've written that as a vector + + align:start position:0% +zero and I've written that as a vector + + + align:start position:0% +zero and I've written that as a vector +but that means that means x1 greater + + align:start position:0% +but that means that means x1 greater + + + align:start position:0% +but that means that means x1 greater +equals zero on to X so it's a vector + + align:start position:0% +equals zero on to X so it's a vector + + + align:start position:0% +equals zero on to X so it's a vector +inequality ok so we have a minimizing a + + align:start position:0% +inequality ok so we have a minimizing a + + + align:start position:0% +inequality ok so we have a minimizing a +very simple function with pretty + + align:start position:0% +very simple function with pretty + + + align:start position:0% +very simple function with pretty +straightforward constraints but in + + align:start position:0% +straightforward constraints but in + + + align:start position:0% +straightforward constraints but in +equality constraints so there the + + align:start position:0% +equality constraints so there the + + + align:start position:0% +equality constraints so there the +instead of these are these two together + + align:start position:0% +instead of these are these two together + + + align:start position:0% +instead of these are these two together +are the constraints that and it's in + + align:start position:0% +are the constraints that and it's in + + + align:start position:0% +are the constraints that and it's in +linear algebra in linear programming + + align:start position:0% +linear algebra in linear programming + + + align:start position:0% +linear algebra in linear programming +language this is called the feasible set + + align:start position:0% +language this is called the feasible set + + + align:start position:0% +language this is called the feasible set +X it's the constraint set capital okay + + align:start position:0% +X it's the constraint set capital okay + + + align:start position:0% +X it's the constraint set capital okay +and in the notes right ok so let me draw + + align:start position:0% +and in the notes right ok so let me draw + + + align:start position:0% +and in the notes right ok so let me draw +a picture to to show maybe here maybe + + align:start position:0% +a picture to to show maybe here maybe + + + align:start position:0% +a picture to to show maybe here maybe +I'll just ask how many of you are + + align:start position:0% +I'll just ask how many of you are + + + align:start position:0% +I'll just ask how many of you are +already familiar with linear programming + + align:start position:0% +already familiar with linear programming + + + align:start position:0% +already familiar with linear programming +oh Allah okay so I won't labor the point + + align:start position:0% +oh Allah okay so I won't labor the point + + + align:start position:0% +oh Allah okay so I won't labor the point +but let me just draw a picture so my + + align:start position:0% +but let me just draw a picture so my + + + align:start position:0% +but let me just draw a picture so my +picture will be just here so that's n + + align:start position:0% +picture will be just here so that's n + + + align:start position:0% +picture will be just here so that's n +equals 3 so this is the X 1 X 2 X 3 + + align:start position:0% +equals 3 so this is the X 1 X 2 X 3 + + + align:start position:0% +equals 3 so this is the X 1 X 2 X 3 +space and X greater or equal 0 means + + align:start position:0% +space and X greater or equal 0 means + + + align:start position:0% +space and X greater or equal 0 means +what it means that I'm in this + + align:start position:0% +what it means that I'm in this + + + align:start position:0% +what it means that I'm in this +one-eighth of the space right if they're + + align:start position:0% +one-eighth of the space right if they're + + + align:start position:0% +one-eighth of the space right if they're +non-negative well I would say Quadrant + + align:start position:0% +non-negative well I would say Quadrant + + + align:start position:0% +non-negative well I would say Quadrant +but I really should say octant because + + align:start position:0% +but I really should say octant because + + + align:start position:0% +but I really should say octant because +it's in there's 1/8 of the full 3d space + + align:start position:0% +it's in there's 1/8 of the full 3d space + + + align:start position:0% +it's in there's 1/8 of the full 3d space +so I'm in here and then maybe I have M + + align:start position:0% +so I'm in here and then maybe I have M + + + align:start position:0% +so I'm in here and then maybe I have M +is + + align:start position:0% +is + + + align:start position:0% +is +maybe just one constraint like so so let + + align:start position:0% +maybe just one constraint like so so let + + + align:start position:0% +maybe just one constraint like so so let +me take the cost to be say X 1 plus 2 X + + align:start position:0% +me take the cost to be say X 1 plus 2 X + + + align:start position:0% +me take the cost to be say X 1 plus 2 X +2 plus 5 X 3 say and the constraint I'm + + align:start position:0% +2 plus 5 X 3 say and the constraint I'm + + + align:start position:0% +2 plus 5 X 3 say and the constraint I'm +just gonna have one equation X 1 plus X + + align:start position:0% +just gonna have one equation X 1 plus X + + + align:start position:0% +just gonna have one equation X 1 plus X +2 let me make it easy make that + + align:start position:0% +2 let me make it easy make that + + + align:start position:0% +2 let me make it easy make that +constraint an easy one too so this is + + align:start position:0% +constraint an easy one too so this is + + + align:start position:0% +constraint an easy one too so this is +the this is what we're going to minimize + + align:start position:0% +the this is what we're going to minimize + + + align:start position:0% +the this is what we're going to minimize +and that's what we have to satisfy as + + align:start position:0% +and that's what we have to satisfy as + + + align:start position:0% +and that's what we have to satisfy as +well as x equals 0 so that's a plain 1 + + align:start position:0% +well as x equals 0 so that's a plain 1 + + + align:start position:0% +well as x equals 0 so that's a plain 1 +equation gives us a plane in r3 the + + align:start position:0% +equation gives us a plane in r3 the + + + align:start position:0% +equation gives us a plane in r3 the +plane would go through what hits the + + align:start position:0% + + + + align:start position:0% + +axes at 3 0 0 and so the minimum the + + align:start position:0% +axes at 3 0 0 and so the minimum the + + + align:start position:0% +axes at 3 0 0 and so the minimum the +point has to lie on that plane and it + + align:start position:0% +point has to lie on that plane and it + + + align:start position:0% +point has to lie on that plane and it +has to lie in the octant so that plane + + align:start position:0% +has to lie in the octant so that plane + + + align:start position:0% +has to lie in the octant so that plane +is chopped off to be a triangle yeah + + align:start position:0% +is chopped off to be a triangle yeah + + + align:start position:0% +is chopped off to be a triangle yeah +this is a good visualization of linear + + align:start position:0% +this is a good visualization of linear + + + align:start position:0% +this is a good visualization of linear +programming and what's the conclusion + + align:start position:0% +programming and what's the conclusion + + + align:start position:0% +programming and what's the conclusion +well our cost is linear so the result is + + align:start position:0% +well our cost is linear so the result is + + + align:start position:0% +well our cost is linear so the result is +that one of these three corners is the + + align:start position:0% +that one of these three corners is the + + + align:start position:0% +that one of these three corners is the +winner it could happen it could happen + + align:start position:0% +winner it could happen it could happen + + + align:start position:0% +winner it could happen it could happen +that maybe I have equal values on those + + align:start position:0% +that maybe I have equal values on those + + + align:start position:0% +that maybe I have equal values on those +two corners and therefore all the way + + align:start position:0% +two corners and therefore all the way + + + align:start position:0% +two corners and therefore all the way +along would be also winners but when I + + align:start position:0% +along would be also winners but when I + + + align:start position:0% +along would be also winners but when I +have a linear function it's a maximum at + + align:start position:0% +have a linear function it's a maximum at + + + align:start position:0% +have a linear function it's a maximum at +the end and these are the ends those + + align:start position:0% +the end and these are the ends those + + + align:start position:0% +the end and these are the ends those +three corners so so three zero zero zero + + align:start position:0% +three corners so so three zero zero zero + + + align:start position:0% +three corners so so three zero zero zero +three zero or zero zero three are the + + align:start position:0% +three zero or zero zero three are the + + + align:start position:0% +three zero or zero zero three are the +three corners + + align:start position:0% +three corners + + + align:start position:0% +three corners +and one of those is the winner and the + + align:start position:0% +and one of those is the winner and the + + + align:start position:0% +and one of those is the winner and the +problem is solved and forth in fact for + + align:start position:0% +problem is solved and forth in fact for + + + align:start position:0% +problem is solved and forth in fact for +this case since I'm minimizing I guess + + align:start position:0% +this case since I'm minimizing I guess + + + align:start position:0% +this case since I'm minimizing I guess +it would be that corner that + + align:start position:0% +it would be that corner that + + + align:start position:0% +it would be that corner that +wind so let me give it a star not an x-y + + align:start position:0% +wind so let me give it a star not an x-y + + + align:start position:0% +wind so let me give it a star not an x-y +s-300 cuz that oh no that three so the + + align:start position:0% +s-300 cuz that oh no that three so the + + + align:start position:0% +s-300 cuz that oh no that three so the +value turned out to be three at the + + align:start position:0% +value turned out to be three at the + + + align:start position:0% +value turned out to be three at the +point 3 zeros it and that's a star okay + + align:start position:0% +point 3 zeros it and that's a star okay + + + align:start position:0% +point 3 zeros it and that's a star okay +good good good good okay what what more + + align:start position:0% +good good good good okay what what more + + + align:start position:0% +good good good good okay what what more +do I want to do I said yes should it be + + align:start position:0% +do I want to do I said yes should it be + + + align:start position:0% +do I want to do I said yes should it be +so no zero zero zero three + + align:start position:0% +so no zero zero zero three + + + align:start position:0% +so no zero zero zero three +where's the next three is three that's + + align:start position:0% +where's the next three is three that's + + + align:start position:0% +where's the next three is three that's +fine that gives us a chance I think that + + align:start position:0% +fine that gives us a chance I think that + + + align:start position:0% +fine that gives us a chance I think that +would give me cost of 15 this would give + + align:start position:0% +would give me cost of 15 this would give + + + align:start position:0% +would give me cost of 15 this would give +me a cost of 6 and that would give me + + align:start position:0% +me a cost of 6 and that would give me + + + align:start position:0% +me a cost of 6 and that would give me +across the street + + align:start position:0% +across the street + + + align:start position:0% +across the street +yeah it's obviously if we could + + align:start position:0% +yeah it's obviously if we could + + + align:start position:0% +yeah it's obviously if we could +enumerate all the corners we would have + + align:start position:0% +enumerate all the corners we would have + + + align:start position:0% +enumerate all the corners we would have +a super fast way to get the answer but + + align:start position:0% +a super fast way to get the answer but + + + align:start position:0% +a super fast way to get the answer but +the trouble is of course that for large + + align:start position:0% +the trouble is of course that for large + + + align:start position:0% +the trouble is of course that for large +values and an amount of M and n there + + align:start position:0% +values and an amount of M and n there + + + align:start position:0% +values and an amount of M and n there +are exponentially many corners and we + + align:start position:0% +are exponentially many corners and we + + + align:start position:0% +are exponentially many corners and we +don't want to see them all so that's + + align:start position:0% +don't want to see them all so that's + + + align:start position:0% +don't want to see them all so that's +what makes linear programming take time + + align:start position:0% +what makes linear programming take time + + + align:start position:0% +what makes linear programming take time +and need ideas so for algorithms there + + align:start position:0% +and need ideas so for algorithms there + + + align:start position:0% +and need ideas so for algorithms there +are two types of algorithms two types of + + align:start position:0% +are two types of algorithms two types of + + + align:start position:0% +are two types of algorithms two types of +codes it's all these the older as well + + align:start position:0% +codes it's all these the older as well + + + align:start position:0% +codes it's all these the older as well +established ones are so one way is the + + align:start position:0% +established ones are so one way is the + + + align:start position:0% +established ones are so one way is the +simplex method which finds a corner we + + align:start position:0% +simplex method which finds a corner we + + + align:start position:0% +simplex method which finds a corner we +know the optimum is some one of the + + align:start position:0% +know the optimum is some one of the + + + align:start position:0% +know the optimum is some one of the +corners so it can find it'll find one + + align:start position:0% +corners so it can find it'll find one + + + align:start position:0% +corners so it can find it'll find one +corner and we'll go to the next corner + + align:start position:0% + + + + align:start position:0% + +so if it starts if it starts at one of + + align:start position:0% +so if it starts if it starts at one of + + + align:start position:0% +so if it starts if it starts at one of +these corners it will travel along along + + align:start position:0% +these corners it will travel along along + + + align:start position:0% +these corners it will travel along along +an edge that lowers the cost and it has + + align:start position:0% +an edge that lowers the cost and it has + + + align:start position:0% +an edge that lowers the cost and it has +to stop at the end because it's linear + + align:start position:0% +to stop at the end because it's linear + + + align:start position:0% +to stop at the end because it's linear +the cost will keep going down and going + + align:start position:0% +the cost will keep going down and going + + + align:start position:0% +the cost will keep going down and going +down until it bumps up into bumps into + + align:start position:0% +down until it bumps up into bumps into + + + align:start position:0% +down until it bumps up into bumps into +the end point and then it can't go + + align:start position:0% +the end point and then it can't go + + + align:start position:0% +the end point and then it can't go +further and then we would from that next + + align:start position:0% +further and then we would from that next + + + align:start position:0% +further and then we would from that next +corner we would go to a next corner each + + align:start position:0% +corner we would go to a next corner each + + + align:start position:0% +corner we would go to a next corner each +time it's like steepest descent on the + + align:start position:0% +time it's like steepest descent on the + + + align:start position:0% +time it's like steepest descent on the +con the edges we from the first corner + + align:start position:0% +con the edges we from the first corner + + + align:start position:0% +con the edges we from the first corner +we go the steepest way till we can't go + + align:start position:0% +we go the steepest way till we can't go + + + align:start position:0% +we go the steepest way till we can't go +further we've hit another corner and we + + align:start position:0% +further we've hit another corner and we + + + align:start position:0% +further we've hit another corner and we +and we recompute a linear algebra find + + align:start position:0% +and we recompute a linear algebra find + + + align:start position:0% +and we recompute a linear algebra find +which direction is steepest from there + + align:start position:0% +which direction is steepest from there + + + align:start position:0% +which direction is steepest from there +and and so that's the idea of the + + align:start position:0% +and and so that's the idea of the + + + align:start position:0% +and and so that's the idea of the +simplex method which was invented by + + align:start position:0% +simplex method which was invented by + + + align:start position:0% +simplex method which was invented by +dancing and and the algebra is not going + + align:start position:0% +dancing and and the algebra is not going + + + align:start position:0% +dancing and and the algebra is not going +to be in today's lecture but it's + + align:start position:0% +to be in today's lecture but it's + + + align:start position:0% +to be in today's lecture but it's +straightforward well people have to + + align:start position:0% +straightforward well people have to + + + align:start position:0% +straightforward well people have to +optimize it because that's a highly + + align:start position:0% +optimize it because that's a highly + + + align:start position:0% +optimize it because that's a highly +frequently used method yeah okay but + + align:start position:0% +frequently used method yeah okay but + + + align:start position:0% +frequently used method yeah okay but +then about 20 years later maybe or 30 I + + align:start position:0% +then about 20 years later maybe or 30 I + + + align:start position:0% +then about 20 years later maybe or 30 I +remember going to a lecture in downtown + + align:start position:0% +remember going to a lecture in downtown + + + align:start position:0% +remember going to a lecture in downtown +Boston by karmarkar so I have to put his + + align:start position:0% +Boston by karmarkar so I have to put his + + + align:start position:0% +Boston by karmarkar so I have to put his +name down our marker and he was in the + + align:start position:0% +name down our marker and he was in the + + + align:start position:0% +name down our marker and he was in the +New York Times all the newspapers so it + + align:start position:0% +New York Times all the newspapers so it + + + align:start position:0% +New York Times all the newspapers so it +was a big deal he had an alternative + + align:start position:0% +was a big deal he had an alternative + + + align:start position:0% +was a big deal he had an alternative +algorithm and the exact algorithm he he + + align:start position:0% +algorithm and the exact algorithm he he + + + align:start position:0% +algorithm and the exact algorithm he he +proposed hasn't survived until today but + + align:start position:0% +proposed hasn't survived until today but + + + align:start position:0% +proposed hasn't survived until today but +the idea has and the idea was to go to + + align:start position:0% +the idea has and the idea was to go to + + + align:start position:0% +the idea has and the idea was to go to +travel inside the feasible set and not + + align:start position:0% +travel inside the feasible set and not + + + align:start position:0% +travel inside the feasible set and not +around the edges + + align:start position:0% +around the edges + + + align:start position:0% +around the edges +so his idea because in in in here we + + align:start position:0% +so his idea because in in in here we + + + align:start position:0% +so his idea because in in in here we +maybe travel down near that edge start + + align:start position:0% +maybe travel down near that edge start + + + align:start position:0% +maybe travel down near that edge start +again travel again so its steepest + + align:start position:0% +again travel again so its steepest + + + align:start position:0% +again travel again so its steepest +descent in the in the constraint set the + + align:start position:0% +descent in the in the constraint set the + + + align:start position:0% +descent in the in the constraint set the +feasible set and you can use calculus + + align:start position:0% +feasible set and you can use calculus + + + align:start position:0% +feasible set and you can use calculus +and and this idea so this is this is + + align:start position:0% +and and this idea so this is this is + + + align:start position:0% +and and this idea so this is this is +interior point methods so I'll just use + + align:start position:0% +interior point methods so I'll just use + + + align:start position:0% +interior point methods so I'll just use +the word interior that's telling us that + + align:start position:0% +the word interior that's telling us that + + + align:start position:0% +the word interior that's telling us that +we're we're inside the feasible set we + + align:start position:0% +we're we're inside the feasible set we + + + align:start position:0% +we're we're inside the feasible set we +don't hit come all the way to the + + align:start position:0% +don't hit come all the way to the + + + align:start position:0% +don't hit come all the way to the +boundary intentionally because we want + + align:start position:0% +boundary intentionally because we want + + + align:start position:0% +boundary intentionally because we want +room to move and to find derivatives + + align:start position:0% +room to move and to find derivatives + + + align:start position:0% +room to move and to find derivatives +empty whose Newton's message to minimize + + align:start position:0% +empty whose Newton's message to minimize + + + align:start position:0% +empty whose Newton's message to minimize +you see you choose a search Direction + + align:start position:0% +you see you choose a search Direction + + + align:start position:0% +you see you choose a search Direction +just as all of optimization does and in + + align:start position:0% +just as all of optimization does and in + + + align:start position:0% +just as all of optimization does and in +that search Direction you track it and + + align:start position:0% +that search Direction you track it and + + + align:start position:0% +that search Direction you track it and +you come you stop before you bump into + + align:start position:0% +you come you stop before you bump into + + + align:start position:0% +you come you stop before you bump into +the edge of the feasible set and then + + align:start position:0% +the edge of the feasible set and then + + + align:start position:0% +the edge of the feasible set and then +you compute derivatives again so you can + + align:start position:0% +you compute derivatives again so you can + + + align:start position:0% +you compute derivatives again so you can +use calculus and it it's a method that + + align:start position:0% +use calculus and it it's a method that + + + align:start position:0% +use calculus and it it's a method that +it's an idea that the interior idea came + + align:start position:0% +it's an idea that the interior idea came + + + align:start position:0% +it's an idea that the interior idea came +before car marker but he got super + + align:start position:0% +before car marker but he got super + + + align:start position:0% +before car marker but he got super +publicity so it really got attention got + + align:start position:0% +publicity so it really got attention got + + + align:start position:0% +publicity so it really got attention got +new thinking and new ideas came partly + + align:start position:0% +new thinking and new ideas came partly + + + align:start position:0% +new thinking and new ideas came partly +from people at MIT and and these two are + + align:start position:0% +from people at MIT and and these two are + + + align:start position:0% +from people at MIT and and these two are +now still locked in competition no one + + align:start position:0% +now still locked in competition no one + + + align:start position:0% +now still locked in competition no one +hasn't beaten the other in in all + + align:start position:0% +hasn't beaten the other in in all + + + align:start position:0% +hasn't beaten the other in in all +problems so so linear programming is + + align:start position:0% +problems so so linear programming is + + + align:start position:0% +problems so so linear programming is +here but then for nonlinear programming + + align:start position:0% +here but then for nonlinear programming + + + align:start position:0% +here but then for nonlinear programming +quadratic programming where the cost is + + align:start position:0% +quadratic programming where the cost is + + + align:start position:0% +quadratic programming where the cost is +quadratic nonlinear programming semi + + align:start position:0% +quadratic nonlinear programming semi + + + align:start position:0% +quadratic nonlinear programming semi +definite programming that's where you + + align:start position:0% +definite programming that's where you + + + align:start position:0% +definite programming that's where you +have a matrix unknown a matrix + + align:start position:0% +have a matrix unknown a matrix + + + align:start position:0% +have a matrix unknown a matrix +constraints those are all the more + + align:start position:0% +constraints those are all the more + + + align:start position:0% +constraints those are all the more +complicated you get the more it tends to + + align:start position:0% +complicated you get the more it tends to + + + align:start position:0% +complicated you get the more it tends to +be + + align:start position:0% +be + + + align:start position:0% +be +interior point methods okay that's a + + align:start position:0% +interior point methods okay that's a + + + align:start position:0% +interior point methods okay that's a +summary of linear programming now I'd + + align:start position:0% +summary of linear programming now I'd + + + align:start position:0% +summary of linear programming now I'd +like to give an example and then I + + align:start position:0% +like to give an example and then I + + + align:start position:0% +like to give an example and then I +haven't told you the main well let me + + align:start position:0% +haven't told you the main well let me + + + align:start position:0% +haven't told you the main well let me +tell you the main fact about duality + + align:start position:0% +tell you the main fact about duality + + + align:start position:0% +tell you the main fact about duality +okay + + align:start position:0% +okay + + + align:start position:0% +okay +this is really and I'll write that maybe + + align:start position:0% +this is really and I'll write that maybe + + + align:start position:0% +this is really and I'll write that maybe +here next to it so do a duality if + + align:start position:0% +here next to it so do a duality if + + + align:start position:0% +here next to it so do a duality if +there's a dual procure LP and that dual + + align:start position:0% +there's a dual procure LP and that dual + + + align:start position:0% +there's a dual procure LP and that dual +is going to do a maximum instead of a + + align:start position:0% +is going to do a maximum instead of a + + + align:start position:0% +is going to do a maximum instead of a +minimum and the cost is is going to + + align:start position:0% +minimum and the cost is is going to + + + align:start position:0% +minimum and the cost is is going to +involve the B from the primal problem so + + align:start position:0% +involve the B from the primal problem so + + + align:start position:0% +involve the B from the primal problem so +this is now called the primal problem + + align:start position:0% +this is now called the primal problem + + + align:start position:0% +this is now called the primal problem +and this is its dual so there are twin + + align:start position:0% +and this is its dual so there are twin + + + align:start position:0% +and this is its dual so there are twin +problems they use the same data but + + align:start position:0% +problems they use the same data but + + + align:start position:0% +problems they use the same data but +quite differently it's like transposing + + align:start position:0% +quite differently it's like transposing + + + align:start position:0% +quite differently it's like transposing +things so so let's call the unknown Y so + + align:start position:0% +things so so let's call the unknown Y so + + + align:start position:0% +things so so let's call the unknown Y so +for y to be the right hand side over + + align:start position:0% +for y to be the right hand side over + + + align:start position:0% +for y to be the right hand side over +here is M by 1 so that's maximize that + + align:start position:0% +here is M by 1 so that's maximize that + + + align:start position:0% +here is M by 1 so that's maximize that +we're subject to what are the + + align:start position:0% +we're subject to what are the + + + align:start position:0% +we're subject to what are the +constraints well the cost function over + + align:start position:0% +constraints well the cost function over + + + align:start position:0% +constraints well the cost function over +here see the cost vector goes into the + + align:start position:0% +here see the cost vector goes into the + + + align:start position:0% +here see the cost vector goes into the +constraints and I think the greater + + align:start position:0% +constraints and I think the greater + + + align:start position:0% +constraints and I think the greater +equal sign because obably becomes a less + + align:start position:0% +equal sign because obably becomes a less + + + align:start position:0% +equal sign because obably becomes a less +or equal to sign the a gets transposed I + + align:start position:0% +or equal to sign the a gets transposed I + + + align:start position:0% +or equal to sign the a gets transposed I +think that's probably probably the + + align:start position:0% +think that's probably probably the + + + align:start position:0% +think that's probably probably the +constraint in the dual and it happens it + + align:start position:0% +constraint in the dual and it happens it + + + align:start position:0% +constraint in the dual and it happens it +doesn't need Y we don't have y greater + + align:start position:0% +doesn't need Y we don't have y greater + + + align:start position:0% +doesn't need Y we don't have y greater +equal 0 over here ok so that's a dual + + align:start position:0% +equal 0 over here ok so that's a dual + + + align:start position:0% +equal 0 over here ok so that's a dual +problem it has a linear cost it has + + align:start position:0% +problem it has a linear cost it has + + + align:start position:0% +problem it has a linear cost it has +linear inequality constraints it can be + + align:start position:0% +linear inequality constraints it can be + + + align:start position:0% +linear inequality constraints it can be +solved by the simplex method you could + + align:start position:0% +solved by the simplex method you could + + + align:start position:0% +solved by the simplex method you could +choose whether you solve that one or + + align:start position:0% +choose whether you solve that one or + + + align:start position:0% +choose whether you solve that one or +this one because if you solve one you + + align:start position:0% +this one because if you solve one you + + + align:start position:0% +this one because if you solve one you +solve the other + + align:start position:0% +solve the other + + + align:start position:0% +solve the other +the two are closely connected and that's + + align:start position:0% +the two are closely connected and that's + + + align:start position:0% +the two are closely connected and that's +the key idea of duality so maybe I'll + + align:start position:0% +the key idea of duality so maybe I'll + + + align:start position:0% +the key idea of duality so maybe I'll +put the idea first of all of wheat + + align:start position:0% +put the idea first of all of wheat + + + align:start position:0% +put the idea first of all of wheat +duality which says that the this + + align:start position:0% +duality which says that the this + + + align:start position:0% +duality which says that the this +quantity that we're trying to maximize + + align:start position:0% +quantity that we're trying to maximize + + + align:start position:0% +quantity that we're trying to maximize +we're getting it as large as possible is + + align:start position:0% +we're getting it as large as possible is + + + align:start position:0% +we're getting it as large as possible is +always less lesser equal to any C + + align:start position:0% +always less lesser equal to any C + + + align:start position:0% +always less lesser equal to any C +transpose X this is for for any this is + + align:start position:0% +transpose X this is for for any this is + + + align:start position:0% +transpose X this is for for any this is +for any feasible allowed any can any any + + align:start position:0% +for any feasible allowed any can any any + + + align:start position:0% +for any feasible allowed any can any any +X&Y that are that satisfy the + + align:start position:0% +X&Y that are that satisfy the + + + align:start position:0% +X&Y that are that satisfy the +constraints remember feasible means + + align:start position:0% +constraints remember feasible means + + + align:start position:0% +constraints remember feasible means +satisfies the constraint so in other + + align:start position:0% +satisfies the constraint so in other + + + align:start position:0% +satisfies the constraint so in other +words this problem this maximization + + align:start position:0% +words this problem this maximization + + + align:start position:0% +words this problem this maximization +problem you're trying to push this up + + align:start position:0% +problem you're trying to push this up + + + align:start position:0% +problem you're trying to push this up +the minimization problem you're trying + + align:start position:0% +the minimization problem you're trying + + + align:start position:0% +the minimization problem you're trying +to pull this down and it's easy to show + + align:start position:0% +to pull this down and it's easy to show + + + align:start position:0% +to pull this down and it's easy to show +that the one that B transpose it's easy + + align:start position:0% +that the one that B transpose it's easy + + + align:start position:0% +that the one that B transpose it's easy +to show that inequality let's do that so + + align:start position:0% +to show that inequality let's do that so + + + align:start position:0% +to show that inequality let's do that so +B transpose Y true should be a one-line + + align:start position:0% +B transpose Y true should be a one-line + + + align:start position:0% +B transpose Y true should be a one-line +proof so B transpose Y ok what do I do + + align:start position:0% +proof so B transpose Y ok what do I do + + + align:start position:0% +proof so B transpose Y ok what do I do +so B transpose Y well I look over here + + align:start position:0% +so B transpose Y well I look over here + + + align:start position:0% +so B transpose Y well I look over here +that's where B shows up that's X + + align:start position:0% +that's where B shows up that's X + + + align:start position:0% +that's where B shows up that's X +transpose a transpose Y right because B + + align:start position:0% +transpose a transpose Y right because B + + + align:start position:0% +transpose a transpose Y right because B +is ax + + align:start position:0% +is ax + + + align:start position:0% +is ax +I'm feasible so my B is a X and for any + + align:start position:0% +I'm feasible so my B is a X and for any + + + align:start position:0% +I'm feasible so my B is a X and for any +X this is for this is for any X that B + + align:start position:0% +X this is for this is for any X that B + + + align:start position:0% +X this is for this is for any X that B +is going to be ax so am I good so far + + align:start position:0% +is going to be ax so am I good so far + + + align:start position:0% +is going to be ax so am I good so far +and now what do I do but now I look here + + align:start position:0% +and now what do I do but now I look here + + + align:start position:0% +and now what do I do but now I look here +I see a transpose Y sitting right in + + align:start position:0% +I see a transpose Y sitting right in + + + align:start position:0% +I see a transpose Y sitting right in +front of me so I say well ok unless or + + align:start position:0% +front of me so I say well ok unless or + + + align:start position:0% +front of me so I say well ok unless or +equal to and I guess I'm done a + + align:start position:0% +equal to and I guess I'm done a + + + align:start position:0% +equal to and I guess I'm done a +transpose wise less or equal to C so I + + align:start position:0% +transpose wise less or equal to C so I + + + align:start position:0% +transpose wise less or equal to C so I +have X transpose C C transpose X + + align:start position:0% +have X transpose C C transpose X + + + align:start position:0% +have X transpose C C transpose X +so so equal this equals this less or + + align:start position:0% +so so equal this equals this less or + + + align:start position:0% +so so equal this equals this less or +equal that I've got it weak duality is + + align:start position:0% +equal that I've got it weak duality is + + + align:start position:0% +equal that I've got it weak duality is +just put together the the requirements + + align:start position:0% +just put together the the requirements + + + align:start position:0% +just put together the the requirements +on x and y and you have it but word it + + align:start position:0% +on x and y and you have it but word it + + + align:start position:0% +on x and y and you have it but word it +was this important you know if the + + align:start position:0% +was this important you know if the + + + align:start position:0% +was this important you know if the +mathematics is right everything has to + + align:start position:0% +mathematics is right everything has to + + + align:start position:0% +mathematics is right everything has to +have it please play its role and so + + align:start position:0% +have it please play its role and so + + + align:start position:0% +have it please play its role and so +what's the role of X greater equal zero + + align:start position:0% +what's the role of X greater equal zero + + + align:start position:0% +what's the role of X greater equal zero +there why do we need X if we just even + + align:start position:0% +there why do we need X if we just even + + + align:start position:0% +there why do we need X if we just even +think of an equal one just a number Y + + align:start position:0% +think of an equal one just a number Y + + + align:start position:0% +think of an equal one just a number Y +where do we use the fact that X is + + align:start position:0% +where do we use the fact that X is + + + align:start position:0% +where do we use the fact that X is +greater or equal 0 do we do we use it + + align:start position:0% +greater or equal 0 do we do we use it + + + align:start position:0% +greater or equal 0 do we do we use it +this looks so so smooth because a + + align:start position:0% +this looks so so smooth because a + + + align:start position:0% +this looks so so smooth because a +transpose Y I'll write down as X + + align:start position:0% +transpose Y I'll write down as X + + + align:start position:0% +transpose Y I'll write down as X +transpose C for the moment just just so + + align:start position:0% +transpose C for the moment just just so + + + align:start position:0% +transpose C for the moment just just so +your eye says the same X transpose and + + align:start position:0% +your eye says the same X transpose and + + + align:start position:0% +your eye says the same X transpose and +the a transpose Y is lesser equals C + + align:start position:0% +the a transpose Y is lesser equals C + + + align:start position:0% +the a transpose Y is lesser equals C +where is X greater equal zero coming in + + align:start position:0% +where is X greater equal zero coming in + + + align:start position:0% +where is X greater equal zero coming in +yes + + align:start position:0% +yes + + + align:start position:0% +yes +yeah that's true but but I want to see + + align:start position:0% +yeah that's true but but I want to see + + + align:start position:0% +yeah that's true but but I want to see +yeah so here's my point that the fact + + align:start position:0% +yeah so here's my point that the fact + + + align:start position:0% +yeah so here's my point that the fact +that a transpose Y is lesser equals C + + align:start position:0% +that a transpose Y is lesser equals C + + + align:start position:0% +that a transpose Y is lesser equals C +that's fine highly important but if X + + align:start position:0% +that's fine highly important but if X + + + align:start position:0% +that's fine highly important but if X +was negative it would be the other way + + align:start position:0% +was negative it would be the other way + + + align:start position:0% +was negative it would be the other way +you would you would get the other way + + align:start position:0% +you would you would get the other way + + + align:start position:0% +you would you would get the other way +and you wouldn't have what you want so + + align:start position:0% +and you wouldn't have what you want so + + + align:start position:0% +and you wouldn't have what you want so +we really do use the fact that X is + + align:start position:0% +we really do use the fact that X is + + + align:start position:0% +we really do use the fact that X is +greater equals zero to say that I have + + align:start position:0% +greater equals zero to say that I have + + + align:start position:0% +greater equals zero to say that I have +national equal this and then I multiply + + align:start position:0% +national equal this and then I multiply + + + align:start position:0% +national equal this and then I multiply +by something positive and then I still + + align:start position:0% +by something positive and then I still + + + align:start position:0% +by something positive and then I still +have less we okay good so every it's the + + align:start position:0% +have less we okay good so every it's the + + + align:start position:0% +have less we okay good so every it's the +math is right everything does its part + + align:start position:0% +math is right everything does its part + + + align:start position:0% +math is right everything does its part +and then the of course the beautiful + + align:start position:0% +and then the of course the beautiful + + + align:start position:0% +and then the of course the beautiful +result the important result is that + + align:start position:0% +result the important result is that + + + align:start position:0% +result the important result is that +there's strong duality just called + + align:start position:0% +there's strong duality just called + + + align:start position:0% +there's strong duality just called +duality which is that at the maximum now + + align:start position:0% +duality which is that at the maximum now + + + align:start position:0% +duality which is that at the maximum now +this is not for any x and y but this is + + align:start position:0% +this is not for any x and y but this is + + + align:start position:0% +this is not for any x and y but this is +for this is going to be 4x + + align:start position:0% +for this is going to be 4x + + + align:start position:0% +for this is going to be 4x +why star the winner and X star the + + align:start position:0% +why star the winner and X star the + + + align:start position:0% +why star the winner and X star the +winner equality holds so that's to our + + align:start position:0% +winner equality holds so that's to our + + + align:start position:0% +winner equality holds so that's to our +the maximum in the dual problem is the + + align:start position:0% +the maximum in the dual problem is the + + + align:start position:0% +the maximum in the dual problem is the +same as the minimum in the primal + + align:start position:0% +same as the minimum in the primal + + + align:start position:0% +same as the minimum in the primal +problem the two have met there is no + + align:start position:0% +problem the two have met there is no + + + align:start position:0% +problem the two have met there is no +duality gap in some cooked up nonlinear + + align:start position:0% +duality gap in some cooked up nonlinear + + + align:start position:0% +duality gap in some cooked up nonlinear +problems there could be a gap between + + align:start position:0% +problems there could be a gap between + + + align:start position:0% +problems there could be a gap between +the maximum and the minimum but you hope + + align:start position:0% +the maximum and the minimum but you hope + + + align:start position:0% +the maximum and the minimum but you hope +not and here this the big theorem is not + + align:start position:0% +not and here this the big theorem is not + + + align:start position:0% +not and here this the big theorem is not +there equal a matter you push this out + + align:start position:0% +there equal a matter you push this out + + + align:start position:0% +there equal a matter you push this out +push that down so that's another way to + + align:start position:0% +push that down so that's another way to + + + align:start position:0% +push that down so that's another way to +say that duality is that this is I'm + + align:start position:0% +say that duality is that this is I'm + + + align:start position:0% +say that duality is that this is I'm +pushing that up at some map I could + + align:start position:0% +pushing that up at some map I could + + + align:start position:0% +pushing that up at some map I could +write that as a maximum of a minimum + + align:start position:0% +write that as a maximum of a minimum + + + align:start position:0% +write that as a maximum of a minimum +equaling a minimum of a maximum if I + + align:start position:0% +equaling a minimum of a maximum if I + + + align:start position:0% +equaling a minimum of a maximum if I +wanted so it's the duality in linear + + align:start position:0% +wanted so it's the duality in linear + + + align:start position:0% +wanted so it's the duality in linear +programming was the same as one woman's + + align:start position:0% +programming was the same as one woman's + + + align:start position:0% +programming was the same as one woman's +minimax theorem and his theorem applied + + align:start position:0% +minimax theorem and his theorem applied + + + align:start position:0% +minimax theorem and his theorem applied +to two-person games so the kief the key + + align:start position:0% +to two-person games so the kief the key + + + align:start position:0% +to two-person games so the kief the key +math result is that that is duality for + + align:start position:0% +math result is that that is duality for + + + align:start position:0% +math result is that that is duality for +linear programming and it's gonna be + + align:start position:0% +linear programming and it's gonna be + + + align:start position:0% +linear programming and it's gonna be +you'll see the same thing happening for + + align:start position:0% +you'll see the same thing happening for + + + align:start position:0% +you'll see the same thing happening for +two-person games and it's a minimax + + align:start position:0% +two-person games and it's a minimax + + + align:start position:0% +two-person games and it's a minimax +theorem or a saddle point or it's just + + align:start position:0% +theorem or a saddle point or it's just + + + align:start position:0% +theorem or a saddle point or it's just +things come out right yep yep so just to + + align:start position:0% +things come out right yep yep so just to + + + align:start position:0% +things come out right yep yep so just to +mention that mathematical programming of + + align:start position:0% +mention that mathematical programming of + + + align:start position:0% +mention that mathematical programming of +course includes much more difficult + + align:start position:0% +course includes much more difficult + + + align:start position:0% +course includes much more difficult +problems this is linear programming that + + align:start position:0% +problems this is linear programming that + + + align:start position:0% +problems this is linear programming that +problem as you see is as a beautiful + + align:start position:0% +problem as you see is as a beautiful + + + align:start position:0% +problem as you see is as a beautiful +simple theory and the paying attention + + align:start position:0% +simple theory and the paying attention + + + align:start position:0% +simple theory and the paying attention +is paying attention to the algorithm + + align:start position:0% +is paying attention to the algorithm + + + align:start position:0% +is paying attention to the algorithm +because you've got two important choices + + align:start position:0% +because you've got two important choices + + + align:start position:0% +because you've got two important choices +and they both get highly developed + + align:start position:0% + + + + align:start position:0% + +now okay so for game now I'm gonna turn + + align:start position:0% +now okay so for game now I'm gonna turn + + + align:start position:0% +now okay so for game now I'm gonna turn +to well I'll do a example of max flow + + align:start position:0% +to well I'll do a example of max flow + + + align:start position:0% +to well I'll do a example of max flow +equal min cut to see what and then go to + + align:start position:0% +equal min cut to see what and then go to + + + align:start position:0% +equal min cut to see what and then go to +two two person game so here's a here's + + align:start position:0% +two two person game so here's a here's + + + align:start position:0% +two two person game so here's a here's +an example + + align:start position:0% + + + + align:start position:0% + +okay so I start with a graph yeah let me + + align:start position:0% +okay so I start with a graph yeah let me + + + align:start position:0% +okay so I start with a graph yeah let me +just so this is the source this is the + + align:start position:0% +just so this is the source this is the + + + align:start position:0% +just so this is the source this is the +sink and I'm sending flow through the + + align:start position:0% +sink and I'm sending flow through the + + + align:start position:0% +sink and I'm sending flow through the +network so it's a network that I'm + + align:start position:0% +network so it's a network that I'm + + + align:start position:0% +network so it's a network that I'm +sending flow through so I'm so my job is + + align:start position:0% +sending flow through so I'm so my job is + + + align:start position:0% +sending flow through so I'm so my job is +to maximize yeah is to I'll set X at the + + align:start position:0% +to maximize yeah is to I'll set X at the + + + align:start position:0% +to maximize yeah is to I'll set X at the +source to be zero and then the flow the + + align:start position:0% +source to be zero and then the flow the + + + align:start position:0% +source to be zero and then the flow the +total flow will come into the sink so I + + align:start position:0% +total flow will come into the sink so I + + + align:start position:0% +total flow will come into the sink so I +want to maximize X at the sink so it's + + align:start position:0% +want to maximize X at the sink so it's + + + align:start position:0% +want to maximize X at the sink so it's +of linear programming and their + + align:start position:0% +of linear programming and their + + + align:start position:0% +of linear programming and their +constraint so what are the constraints + + align:start position:0% +constraint so what are the constraints + + + align:start position:0% +constraint so what are the constraints +every Edge has a capacity so let's see + + align:start position:0% +every Edge has a capacity so let's see + + + align:start position:0% +every Edge has a capacity so let's see +suppose that Edge has capacity 5 let me + + align:start position:0% +suppose that Edge has capacity 5 let me + + + align:start position:0% +suppose that Edge has capacity 5 let me +let me put capacities on all these edges + + align:start position:0% +let me put capacities on all these edges + + + align:start position:0% +let me put capacities on all these edges +2 1 3 4 I'm just stabbing around here + + align:start position:0% + + + + align:start position:0% + +let me say - ok I have no idea what's + + align:start position:0% +let me say - ok I have no idea what's + + + align:start position:0% +let me say - ok I have no idea what's +happening here + + align:start position:0% +happening here + + + align:start position:0% +happening here +but if we see the problem we'll probably + + align:start position:0% +but if we see the problem we'll probably + + + align:start position:0% +but if we see the problem we'll probably +be able to solve it so so these + + align:start position:0% +be able to solve it so so these + + + align:start position:0% +be able to solve it so so these +constraints are that the flow variable + + align:start position:0% +constraints are that the flow variable + + + align:start position:0% +constraints are that the flow variable +which would be would be the why that + + align:start position:0% +which would be would be the why that + + + align:start position:0% +which would be would be the why that +where I'm trying to maximize cannot to + + align:start position:0% +where I'm trying to maximize cannot to + + + align:start position:0% +where I'm trying to maximize cannot to +the amount of flow just in ordinary + + align:start position:0% +the amount of flow just in ordinary + + + align:start position:0% +the amount of flow just in ordinary +words the amount of flow on the edges + + align:start position:0% +words the amount of flow on the edges + + + align:start position:0% +words the amount of flow on the edges +can't go go higher than the capacity + + align:start position:0% +can't go go higher than the capacity + + + align:start position:0% +can't go go higher than the capacity +I could send eleven along this edge but + + align:start position:0% +I could send eleven along this edge but + + + align:start position:0% +I could send eleven along this edge but +then I've got nowhere to send it after + + align:start position:0% +then I've got nowhere to send it after + + + align:start position:0% +then I've got nowhere to send it after +that I could send well nine hundred on + + align:start position:0% +that I could send well nine hundred on + + + align:start position:0% +that I could send well nine hundred on +that edge but obviously it would get + + align:start position:0% +that edge but obviously it would get + + + align:start position:0% +that edge but obviously it would get +stuck there so the question is what's + + align:start position:0% +stuck there so the question is what's + + + align:start position:0% +stuck there so the question is what's +the maximum I can send through that + + align:start position:0% +the maximum I can send through that + + + align:start position:0% +the maximum I can send through that +network it's a classical problem and and + + align:start position:0% +network it's a classical problem and and + + + align:start position:0% +network it's a classical problem and and +in fact it's it's an integer programming + + align:start position:0% +in fact it's it's an integer programming + + + align:start position:0% +in fact it's it's an integer programming +problem I these are all integer + + align:start position:0% +problem I these are all integer + + + align:start position:0% +problem I these are all integer +capacities I could insist on integer + + align:start position:0% +capacities I could insist on integer + + + align:start position:0% +capacities I could insist on integer +flows but it's a very remarkable integer + + align:start position:0% +flows but it's a very remarkable integer + + + align:start position:0% +flows but it's a very remarkable integer +problem because I could allow fractions + + align:start position:0% +problem because I could allow fractions + + + align:start position:0% +problem because I could allow fractions +and the answer would not be it would not + + align:start position:0% +and the answer would not be it would not + + + align:start position:0% +and the answer would not be it would not +involve fractions in other words if I + + align:start position:0% +involve fractions in other words if I + + + align:start position:0% +involve fractions in other words if I +keep it as an integer problem then the + + align:start position:0% +keep it as an integer problem then the + + + align:start position:0% +keep it as an integer problem then the +mathematics is definitely harder for an + + align:start position:0% +mathematics is definitely harder for an + + + align:start position:0% +mathematics is definitely harder for an +integer problem what's different so so + + align:start position:0% +integer problem what's different so so + + + align:start position:0% +integer problem what's different so so +the x's could be integers or they could + + align:start position:0% +the x's could be integers or they could + + + align:start position:0% +the x's could be integers or they could +be real real numbers over here they were + + align:start position:0% +be real real numbers over here they were + + + align:start position:0% +be real real numbers over here they were +real numbers I happen to get an integer + + align:start position:0% +real numbers I happen to get an integer + + + align:start position:0% +real numbers I happen to get an integer +for this but if I put if I had 10 + + align:start position:0% +for this but if I put if I had 10 + + + align:start position:0% +for this but if I put if I had 10 +crossing planes in 15 dimensions and the + + align:start position:0% +crossing planes in 15 dimensions and the + + + align:start position:0% +crossing planes in 15 dimensions and the +integers would be totally lost but the + + align:start position:0% +integers would be totally lost but the + + + align:start position:0% +integers would be totally lost but the +point is here that if I allow real + + align:start position:0% +point is here that if I allow real + + + align:start position:0% +point is here that if I allow real +numbers it doesn't get me any more flow + + align:start position:0% +numbers it doesn't get me any more flow + + + align:start position:0% +numbers it doesn't get me any more flow +that the winning flow is an integer + + align:start position:0% +that the winning flow is an integer + + + align:start position:0% +that the winning flow is an integer +anyway so it's an integer problem which + + align:start position:0% +anyway so it's an integer problem which + + + align:start position:0% +anyway so it's an integer problem which +can be safely relaxed and you can safely + + align:start position:0% +can be safely relaxed and you can safely + + + align:start position:0% +can be safely relaxed and you can safely +use simplex method or car markers method + + align:start position:0% +use simplex method or car markers method + + + align:start position:0% +use simplex method or car markers method +or in the interior point method + + align:start position:0% +or in the interior point method + + + align:start position:0% +or in the interior point method +with with non integers because in the + + align:start position:0% +with with non integers because in the + + + align:start position:0% +with with non integers because in the +interior here you're not ending it + + align:start position:0% +interior here you're not ending it + + + align:start position:0% +interior here you're not ending it +starting or ending at integers you can + + align:start position:0% +starting or ending at integers you can + + + align:start position:0% +starting or ending at integers you can +do it because the the integer answer + + align:start position:0% +do it because the the integer answer + + + align:start position:0% +do it because the the integer answer +will be in the end better okay and what + + align:start position:0% +will be in the end better okay and what + + + align:start position:0% +will be in the end better okay and what +is that answer + + align:start position:0% +is that answer + + + align:start position:0% +is that answer +III think I've made those capacities + + align:start position:0% +III think I've made those capacities + + + align:start position:0% +III think I've made those capacities +like too easy too + + align:start position:0% +like too easy too + + + align:start position:0% +like too easy too +oh I didn't do this one so so what shall + + align:start position:0% +oh I didn't do this one so so what shall + + + align:start position:0% +oh I didn't do this one so so what shall +I say so I make it large like nine I + + align:start position:0% +I say so I make it large like nine I + + + align:start position:0% +I say so I make it large like nine I +don't know okay what's the best we can + + align:start position:0% +don't know okay what's the best we can + + + align:start position:0% +don't know okay what's the best we can +do through that through that Network + + align:start position:0% +do through that through that Network + + + align:start position:0% +do through that through that Network +okay I can't see it from here yet what + + align:start position:0% +okay I can't see it from here yet what + + + align:start position:0% +okay I can't see it from here yet what +what should I do + + align:start position:0% +what should I do + + + align:start position:0% +what should I do +obviously in this simple problem I can + + align:start position:0% +obviously in this simple problem I can + + + align:start position:0% +obviously in this simple problem I can +get anything I want pretty much to this + + align:start position:0% +get anything I want pretty much to this + + + align:start position:0% +get anything I want pretty much to this +that far but then what can I do + + align:start position:0% + + + + align:start position:0% + +let me let me even make that 19 okay so + + align:start position:0% +let me let me even make that 19 okay so + + + align:start position:0% +let me let me even make that 19 okay so +I'm I'm not imposing much of a limit on + + align:start position:0% +I'm I'm not imposing much of a limit on + + + align:start position:0% +I'm I'm not imposing much of a limit on +that edge either but these edges are + + align:start position:0% +that edge either but these edges are + + + align:start position:0% +that edge either but these edges are +quite tight limits and these are sort of + + align:start position:0% +quite tight limits and these are sort of + + + align:start position:0% +quite tight limits and these are sort of +intermediate limits well what do you + + align:start position:0% +intermediate limits well what do you + + + align:start position:0% +intermediate limits well what do you +think is the most I could send through + + align:start position:0% +think is the most I could send through + + + align:start position:0% +think is the most I could send through +and how would you show me that I + + align:start position:0% +and how would you show me that I + + + align:start position:0% +and how would you show me that I +couldn't send more that's the key + + align:start position:0% +couldn't send more that's the key + + + align:start position:0% +couldn't send more that's the key +question I want to get a bound on an + + align:start position:0% +question I want to get a bound on an + + + align:start position:0% +question I want to get a bound on an +upper bound on this maximum this maximum + + align:start position:0% +upper bound on this maximum this maximum + + + align:start position:0% +upper bound on this maximum this maximum +getting into the sink is less or equal + + align:start position:0% +getting into the sink is less or equal + + + align:start position:0% +getting into the sink is less or equal +to and what what number would you + + align:start position:0% +to and what what number would you + + + align:start position:0% +to and what what number would you +propose could I get a thousand through I + + align:start position:0% +propose could I get a thousand through I + + + align:start position:0% +propose could I get a thousand through I +could start but of course I I wouldn't + + align:start position:0% +could start but of course I I wouldn't + + + align:start position:0% +could start but of course I I wouldn't +tile up there I couldn't get further + + align:start position:0% + + + + align:start position:0% + +what do you what do you think the best I + + align:start position:0% +what do you what do you think the best I + + + align:start position:0% +what do you what do you think the best I +can do + + align:start position:0% + + + + align:start position:0% + +ten I can't do more than ten how how + + align:start position:0% +ten I can't do more than ten how how + + + align:start position:0% +ten I can't do more than ten how how +could I do ten twelve twelve this right + + align:start position:0% + + + + align:start position:0% + +so I I see him that way can this yeah + + align:start position:0% +so I I see him that way can this yeah + + + align:start position:0% +so I I see him that way can this yeah +absolutely you can split and then this + + align:start position:0% +absolutely you can split and then this + + + align:start position:0% +absolutely you can split and then this +can this go here and that would would be + + align:start position:0% +can this go here and that would would be + + + align:start position:0% +can this go here and that would would be +able to go there so I can get ten + + align:start position:0% +able to go there so I can get ten + + + align:start position:0% +able to go there so I can get ten +correct can I do anything better + + align:start position:0% +correct can I do anything better + + + align:start position:0% +correct can I do anything better +oh I could be sending some up this way + + align:start position:0% +oh I could be sending some up this way + + + align:start position:0% +oh I could be sending some up this way +at the same time so I could get three + + align:start position:0% +at the same time so I could get three + + + align:start position:0% +at the same time so I could get three +along the top + + align:start position:0% +along the top + + + align:start position:0% +along the top +I could so this is like an auction okay + + align:start position:0% +I could so this is like an auction okay + + + align:start position:0% +I could so this is like an auction okay +we can get up to 13 can we get so that + + align:start position:0% +we can get up to 13 can we get so that + + + align:start position:0% +we can get up to 13 can we get so that +that was three going this way and ten + + align:start position:0% +that was three going this way and ten + + + align:start position:0% +that was three going this way and ten +going this way is 13 and can I not + + align:start position:0% +going this way is 13 and can I not + + + align:start position:0% +going this way is 13 and can I not +exceed 13 do I hear 40 yeah oh I've got + + align:start position:0% +exceed 13 do I hear 40 yeah oh I've got + + + align:start position:0% +exceed 13 do I hear 40 yeah oh I've got +a lot of room for one more + + align:start position:0% +a lot of room for one more + + + align:start position:0% +a lot of room for one more +so okay so 14 many kids alright do I + + align:start position:0% +so okay so 14 many kids alright do I + + + align:start position:0% +so okay so 14 many kids alright do I +hear 15 if I did 12 then what would I do + + align:start position:0% +hear 15 if I did 12 then what would I do + + + align:start position:0% +hear 15 if I did 12 then what would I do +I send two up here okay what am I gonna + + align:start position:0% +I send two up here okay what am I gonna + + + align:start position:0% +I send two up here okay what am I gonna +do with them from here send them up + + align:start position:0% +do with them from here send them up + + + align:start position:0% +do with them from here send them up +again and along but then now you then + + align:start position:0% +again and along but then now you then + + + align:start position:0% +again and along but then now you then +the three that that I had right now what + + align:start position:0% +the three that that I had right now what + + + align:start position:0% +the three that that I had right now what +would be back of one problem and I'm + + align:start position:0% +would be back of one problem and I'm + + + align:start position:0% +would be back of one problem and I'm +looking for a bound to know when to quit + + align:start position:0% +looking for a bound to know when to quit + + + align:start position:0% +looking for a bound to know when to quit +to know when I've optimized that's the + + align:start position:0% +to know when I've optimized that's the + + + align:start position:0% +to know when I've optimized that's the +whole idea of duality is to find some + + align:start position:0% +whole idea of duality is to find some + + + align:start position:0% +whole idea of duality is to find some +upper thing that I'm trying to push down + + align:start position:0% +upper thing that I'm trying to push down + + + align:start position:0% +upper thing that I'm trying to push down +and but I can't go beyond it so so I + + align:start position:0% +and but I can't go beyond it so so I + + + align:start position:0% +and but I can't go beyond it so so I +don't think I could get more than to see + + align:start position:0% +don't think I could get more than to see + + + align:start position:0% +don't think I could get more than to see +everything has to cross this middle so + + align:start position:0% +everything has to cross this middle so + + + align:start position:0% +everything has to cross this middle so +three and four night I don't think I + + align:start position:0% +three and four night I don't think I + + + align:start position:0% +three and four night I don't think I +could + + align:start position:0% +could + + + align:start position:0% +could +b23 somebody said 24 more than 23 I + + align:start position:0% +b23 somebody said 24 more than 23 I + + + align:start position:0% +b23 somebody said 24 more than 23 I +would be very doubtful because I + + align:start position:0% +would be very doubtful because I + + + align:start position:0% +would be very doubtful because I +couldn't get it across the middle but + + align:start position:0% +couldn't get it across the middle but + + + align:start position:0% +couldn't get it across the middle but +then can I get 23 I doubt it + + align:start position:0% +then can I get 23 I doubt it + + + align:start position:0% +then can I get 23 I doubt it +maybe 14 as best possible so how would + + align:start position:0% +maybe 14 as best possible so how would + + + align:start position:0% +maybe 14 as best possible so how would +we show that 14 is best possible I think + + align:start position:0% +we show that 14 is best possible I think + + + align:start position:0% +we show that 14 is best possible I think +if I could find so this is called the + + align:start position:0% +if I could find so this is called the + + + align:start position:0% +if I could find so this is called the +cut a cut in this in this network so + + align:start position:0% +cut a cut in this in this network so + + + align:start position:0% +cut a cut in this in this network so +yeah I see a cut a cut like there you + + align:start position:0% +yeah I see a cut a cut like there you + + + align:start position:0% +yeah I see a cut a cut like there you +see that every bit of flow has got to + + align:start position:0% +see that every bit of flow has got to + + + align:start position:0% +see that every bit of flow has got to +cross that cut and the total capacity + + align:start position:0% +cross that cut and the total capacity + + + align:start position:0% +cross that cut and the total capacity +crossing is the 3 and the 1 and the 2 + + align:start position:0% +crossing is the 3 and the 1 and the 2 + + + align:start position:0% +crossing is the 3 and the 1 and the 2 +and the 8 which is 14 so I can't get + + align:start position:0% +and the 8 which is 14 so I can't get + + + align:start position:0% +and the 8 which is 14 so I can't get +more than 14 through and somehow that + + align:start position:0% +more than 14 through and somehow that + + + align:start position:0% +more than 14 through and somehow that +cut is loaded to capacity probably those + + align:start position:0% +cut is loaded to capacity probably those + + + align:start position:0% +cut is loaded to capacity probably those +edges all all have to be fully up to + + align:start position:0% +edges all all have to be fully up to + + + align:start position:0% +edges all all have to be fully up to +capacity then that crossed the cut so so + + align:start position:0% +capacity then that crossed the cut so so + + + align:start position:0% +capacity then that crossed the cut so so +the cut is is a separation of edges that + + align:start position:0% +the cut is is a separation of edges that + + + align:start position:0% +the cut is is a separation of edges that +go with a source and sorry nodes that go + + align:start position:0% +go with a source and sorry nodes that go + + + align:start position:0% +go with a source and sorry nodes that go +with a source nodes that go with this + + align:start position:0% +with a source nodes that go with this + + + align:start position:0% +with a source nodes that go with this +thing yeah and and then it's the edges + + align:start position:0% +thing yeah and and then it's the edges + + + align:start position:0% +thing yeah and and then it's the edges +across the cut so I yeah is that okay + + align:start position:0% +across the cut so I yeah is that okay + + + align:start position:0% +across the cut so I yeah is that okay +for an example so that's the duality the + + align:start position:0% +for an example so that's the duality the + + + align:start position:0% +for an example so that's the duality the +maximum flow turned out to be 14 and the + + align:start position:0% +maximum flow turned out to be 14 and the + + + align:start position:0% +maximum flow turned out to be 14 and the +minimum cut turned out to be 14 and when + + align:start position:0% +minimum cut turned out to be 14 and when + + + align:start position:0% +minimum cut turned out to be 14 and when +those matched 14 equal 14 I know I'm + + align:start position:0% +those matched 14 equal 14 I know I'm + + + align:start position:0% +those matched 14 equal 14 I know I'm +through I know I'm through because I'm + + align:start position:0% +through I know I'm through because I'm + + + align:start position:0% +through I know I'm through because I'm +able to get 14 through and I could never + + align:start position:0% +able to get 14 through and I could never + + + align:start position:0% +able to get 14 through and I could never +get more yeah 3 & 4 & 6 & 8 yeah okay + + align:start position:0% +get more yeah 3 & 4 & 6 & 8 yeah okay + + + align:start position:0% +get more yeah 3 & 4 & 6 & 8 yeah okay +and of course the in a big network + + align:start position:0% +and of course the in a big network + + + align:start position:0% +and of course the in a big network +the cut is the maximum cut is not going + + align:start position:0% +the cut is the maximum cut is not going + + + align:start position:0% +the cut is the maximum cut is not going +to be visible well you couldn't you know + + align:start position:0% +to be visible well you couldn't you know + + + align:start position:0% +to be visible well you couldn't you know +they would have thousands of edges you + + align:start position:0% +they would have thousands of edges you + + + align:start position:0% +they would have thousands of edges you +couldn't see what you were doing but but + + align:start position:0% +couldn't see what you were doing but but + + + align:start position:0% +couldn't see what you were doing but but +you could solve this problem fast + + align:start position:0% +you could solve this problem fast + + + align:start position:0% +you could solve this problem fast +actually fast and and it's an important + + align:start position:0% +actually fast and and it's an important + + + align:start position:0% +actually fast and and it's an important +in practice it's an important example a + + align:start position:0% +in practice it's an important example a + + + align:start position:0% +in practice it's an important example a +lot of other things fit into the + + align:start position:0% +lot of other things fit into the + + + align:start position:0% +lot of other things fit into the +max-flow min-cut example and therefore + + align:start position:0% +max-flow min-cut example and therefore + + + align:start position:0% +max-flow min-cut example and therefore +solving it in faster than oh I didn't + + align:start position:0% +solving it in faster than oh I didn't + + + align:start position:0% +solving it in faster than oh I didn't +even say about speed + + align:start position:0% +even say about speed + + + align:start position:0% +even say about speed +so the simplex method almost always its + + align:start position:0% +so the simplex method almost always its + + + align:start position:0% +so the simplex method almost always its +average case den Spielman who was on the + + align:start position:0% +average case den Spielman who was on the + + + align:start position:0% +average case den Spielman who was on the +faculty here who's just terrific in this + + align:start position:0% +faculty here who's just terrific in this + + + align:start position:0% +faculty here who's just terrific in this +area was maybe among the first to study + + align:start position:0% +area was maybe among the first to study + + + align:start position:0% +area was maybe among the first to study +the average case so so for a for an + + align:start position:0% +the average case so so for a for an + + + align:start position:0% +the average case so so for a for an +average choice of a and B and C instead + + align:start position:0% +average choice of a and B and C instead + + + align:start position:0% +average choice of a and B and C instead +of making the worst choice for the worst + + align:start position:0% +of making the worst choice for the worst + + + align:start position:0% +of making the worst choice for the worst +choice you can create a feasible set + + align:start position:0% +choice you can create a feasible set + + + align:start position:0% +choice you can create a feasible set +that it has to go corner Corner corner + + align:start position:0% +that it has to go corner Corner corner + + + align:start position:0% +that it has to go corner Corner corner +corner until to get to the end so the + + align:start position:0% +corner until to get to the end so the + + + align:start position:0% +corner until to get to the end so the +simplex method would take exponentially + + align:start position:0% +simplex method would take exponentially + + + align:start position:0% +simplex method would take exponentially +long but that's extremely rare doesn't + + align:start position:0% +long but that's extremely rare doesn't + + + align:start position:0% +long but that's extremely rare doesn't +happen in practice I think and the + + align:start position:0% +happen in practice I think and the + + + align:start position:0% +happen in practice I think and the +average one is polynomial so it's a fast + + align:start position:0% +average one is polynomial so it's a fast + + + align:start position:0% +average one is polynomial so it's a fast +method on average this but and we can + + align:start position:0% +method on average this but and we can + + + align:start position:0% +method on average this but and we can +show actually that was a famous result + + align:start position:0% +show actually that was a famous result + + + align:start position:0% +show actually that was a famous result +it came from Russia that that linear + + align:start position:0% +it came from Russia that that linear + + + align:start position:0% +it came from Russia that that linear +programming is in the big P versus LP + + align:start position:0% +programming is in the big P versus LP + + + align:start position:0% +programming is in the big P versus LP +world linear programming goes with P + + align:start position:0% +world linear programming goes with P + + + align:start position:0% +world linear programming goes with P +linear programming is a problem that can + + align:start position:0% +linear programming is a problem that can + + + align:start position:0% +linear programming is a problem that can +be solved in polynomial time the simplex + + align:start position:0% +be solved in polynomial time the simplex + + + align:start position:0% +be solved in polynomial time the simplex +method won't always do it but it can be + + align:start position:0% +method won't always do it but it can be + + + align:start position:0% +method won't always do it but it can be +done yeah there came into the world + + align:start position:0% +done yeah there came into the world + + + align:start position:0% +done yeah there came into the world +ellipsoid methods and there was a + + align:start position:0% +ellipsoid methods and there was a + + + align:start position:0% +ellipsoid methods and there was a +exciting time to decide that linear + + align:start position:0% +exciting time to decide that linear + + + align:start position:0% +exciting time to decide that linear +programming was actually P and not LP + + align:start position:0% +programming was actually P and not LP + + + align:start position:0% +programming was actually P and not LP +yep okay so that's okay this is a case + + align:start position:0% +yep okay so that's okay this is a case + + + align:start position:0% +yep okay so that's okay this is a case +of duality where you can understand + + align:start position:0% +of duality where you can understand + + + align:start position:0% +of duality where you can understand +duality you can buy this by the state + + align:start position:0% +duality you can buy this by the state + + + align:start position:0% +duality you can buy this by the state +that the flow can't exceed the capacity + + align:start position:0% +that the flow can't exceed the capacity + + + align:start position:0% +that the flow can't exceed the capacity +of the cut so that's what duality is any + + align:start position:0% +of the cut so that's what duality is any + + + align:start position:0% +of the cut so that's what duality is any +flow it has to be less Rico the capacity + + align:start position:0% +flow it has to be less Rico the capacity + + + align:start position:0% +flow it has to be less Rico the capacity +of any cut their capacity being the sum + + align:start position:0% +of any cut their capacity being the sum + + + align:start position:0% +of any cut their capacity being the sum +of the one so of course there are other + + align:start position:0% +of the one so of course there are other + + + align:start position:0% +of the one so of course there are other +cuts that cut has to be crossed but + + align:start position:0% +cuts that cut has to be crossed but + + + align:start position:0% +cuts that cut has to be crossed but +that's got three seven fourteen twenty + + align:start position:0% +that's got three seven fourteen twenty + + + align:start position:0% +that's got three seven fourteen twenty +two capacity so it the fourteen capacity + + align:start position:0% +two capacity so it the fourteen capacity + + + align:start position:0% +two capacity so it the fourteen capacity +was the was the minimum and I gave the + + align:start position:0% +was the was the minimum and I gave the + + + align:start position:0% +was the was the minimum and I gave the +maximum nice isn't that nice + + align:start position:0% +maximum nice isn't that nice + + + align:start position:0% +maximum nice isn't that nice +yeah okay so there's another world here + + align:start position:0% +yeah okay so there's another world here + + + align:start position:0% +yeah okay so there's another world here +of two person games that also has + + align:start position:0% +of two person games that also has + + + align:start position:0% +of two person games that also has +duality and could be expressed so let me + + align:start position:0% +duality and could be expressed so let me + + + align:start position:0% +duality and could be expressed so let me +just talk finally today about two-person + + align:start position:0% +just talk finally today about two-person + + + align:start position:0% +just talk finally today about two-person +game so the two persons are X&Y of + + align:start position:0% +game so the two persons are X&Y of + + + align:start position:0% +game so the two persons are X&Y of +course what other names good they have + + align:start position:0% +course what other names good they have + + + align:start position:0% +course what other names good they have +and there's a there's a matrix involved + + align:start position:0% +and there's a there's a matrix involved + + + align:start position:0% +and there's a there's a matrix involved +this is the payoff matrix so let me take + + align:start position:0% +this is the payoff matrix so let me take + + + align:start position:0% +this is the payoff matrix so let me take +a very simple game first so X is going + + align:start position:0% +a very simple game first so X is going + + + align:start position:0% +a very simple game first so X is going +to choose one of these rows and Y is + + align:start position:0% +to choose one of these rows and Y is + + + align:start position:0% +to choose one of these rows and Y is +going to choose one of these columns and + + align:start position:0% +going to choose one of these columns and + + + align:start position:0% +going to choose one of these columns and +let's say payoff from x to y I like it + + align:start position:0% +let's say payoff from x to y I like it + + + align:start position:0% +let's say payoff from x to y I like it +that way because then X whose pain is is + + align:start position:0% +that way because then X whose pain is is + + + align:start position:0% +that way because then X whose pain is is +going to be minimizing as X was up here + + align:start position:0% +going to be minimizing as X was up here + + + align:start position:0% +going to be minimizing as X was up here +and y who's collecting is going to be + + align:start position:0% +and y who's collecting is going to be + + + align:start position:0% +and y who's collecting is going to be +maximizing as in the dual so so the + + align:start position:0% +maximizing as in the dual so so the + + + align:start position:0% +maximizing as in the dual so so the +payoff well let's see I think maybe one + + align:start position:0% +payoff well let's see I think maybe one + + + align:start position:0% +payoff well let's see I think maybe one +four to eight would be a probably a + + align:start position:0% +four to eight would be a probably a + + + align:start position:0% +four to eight would be a probably a +fairly easy game to play so that so it's + + align:start position:0% +fairly easy game to play so that so it's + + + align:start position:0% +fairly easy game to play so that so it's +a two-person game zero-sum games + + align:start position:0% +a two-person game zero-sum games + + + align:start position:0% +a two-person game zero-sum games +some means that means all all pay what + + align:start position:0% +some means that means all all pay what + + + align:start position:0% +some means that means all all pay what +ex pays goes to why why gets all that ex + + align:start position:0% +ex pays goes to why why gets all that ex + + + align:start position:0% +ex pays goes to why why gets all that ex +pace there's no third party here no + + align:start position:0% +pace there's no third party here no + + + align:start position:0% +pace there's no third party here no +lawyers involved okay so what would and + + align:start position:0% +lawyers involved okay so what would and + + + align:start position:0% +lawyers involved okay so what would and +why is going to choose a column and X is + + align:start position:0% +why is going to choose a column and X is + + + align:start position:0% +why is going to choose a column and X is +going to choose a row an X wants to make + + align:start position:0% +going to choose a row an X wants to make + + + align:start position:0% +going to choose a row an X wants to make +it small and Y wants to make it big okay + + align:start position:0% +it small and Y wants to make it big okay + + + align:start position:0% +it small and Y wants to make it big okay +so what happens in this game + + align:start position:0% +so what happens in this game + + + align:start position:0% +so what happens in this game +what does y choose to make it big the + + align:start position:0% +what does y choose to make it big the + + + align:start position:0% +what does y choose to make it big the +second column what does X choose to make + + align:start position:0% +second column what does X choose to make + + + align:start position:0% +second column what does X choose to make +it small the first row so it's gonna be + + align:start position:0% +it small the first row so it's gonna be + + + align:start position:0% +it small the first row so it's gonna be +focus in on that too because if Y keeps + + align:start position:0% +focus in on that too because if Y keeps + + + align:start position:0% +focus in on that too because if Y keeps +choosing that column two is the best the + + align:start position:0% +choosing that column two is the best the + + + align:start position:0% +choosing that column two is the best the +least that X is going to have to pay to + + align:start position:0% +least that X is going to have to pay to + + + align:start position:0% +least that X is going to have to pay to +and he achieves that by choosing the + + align:start position:0% +and he achieves that by choosing the + + + align:start position:0% +and he achieves that by choosing the +first row so it's a simple game that's a + + align:start position:0% +first row so it's a simple game that's a + + + align:start position:0% +first row so it's a simple game that's a +saddle point it's a it's a minimum for y + + align:start position:0% +saddle point it's a it's a minimum for y + + + align:start position:0% +saddle point it's a it's a minimum for y +in its column and it's a maximum for X + + align:start position:0% +in its column and it's a maximum for X + + + align:start position:0% +in its column and it's a maximum for X +in its row but of course a matrix and + + align:start position:0% +in its row but of course a matrix and + + + align:start position:0% +in its row but of course a matrix and +other matrix might not have such a + + align:start position:0% +other matrix might not have such a + + + align:start position:0% +other matrix might not have such a +saddle point so that may do you see okay + + align:start position:0% +saddle point so that may do you see okay + + + align:start position:0% +saddle point so that may do you see okay +with this game that would be a sort of + + align:start position:0% +with this game that would be a sort of + + + align:start position:0% +with this game that would be a sort of +straightforward game where simple + + align:start position:0% +straightforward game where simple + + + align:start position:0% +straightforward game where simple +strategy column two every time row one + + align:start position:0% +strategy column two every time row one + + + align:start position:0% +strategy column two every time row one +every time is the optimal but now let me + + align:start position:0% +every time is the optimal but now let me + + + align:start position:0% +every time is the optimal but now let me +just exchange that + + align:start position:0% + + + + align:start position:0% + +so again x1 and x2 y1 and y2 or their + + align:start position:0% +so again x1 and x2 y1 and y2 or their + + + align:start position:0% +so again x1 and x2 y1 and y2 or their +two column what happens now + + align:start position:0% + + + + align:start position:0% + +well why kind of likes the big number + + align:start position:0% +well why kind of likes the big number + + + align:start position:0% +well why kind of likes the big number +eight there so goes for the second + + align:start position:0% +eight there so goes for the second + + + align:start position:0% +eight there so goes for the second +second column still has the bigger + + align:start position:0% +second column still has the bigger + + + align:start position:0% +second column still has the bigger +numbers so Y aims for column two + + align:start position:0% +numbers so Y aims for column two + + + align:start position:0% +numbers so Y aims for column two +but then what does X do what row does x + + align:start position:0% +but then what does X do what row does x + + + align:start position:0% +but then what does X do what row does x +choose if y is in there column to the + + align:start position:0% +choose if y is in there column to the + + + align:start position:0% +choose if y is in there column to the +second okay so so have I found a saddle + + align:start position:0% +second okay so so have I found a saddle + + + align:start position:0% +second okay so so have I found a saddle +point where Y chooses this column X + + align:start position:0% +point where Y chooses this column X + + + align:start position:0% +point where Y chooses this column X +chooses this row is that a saddle point + + align:start position:0% +chooses this row is that a saddle point + + + align:start position:0% +chooses this row is that a saddle point +no because what will Y do now he sees X + + align:start position:0% +no because what will Y do now he sees X + + + align:start position:0% +no because what will Y do now he sees X +choosing the second row all the time and + + align:start position:0% +choosing the second row all the time and + + + align:start position:0% +choosing the second row all the time and +why sees a four very tempting for in + + align:start position:0% +why sees a four very tempting for in + + + align:start position:0% +why sees a four very tempting for in +that row so Y is going to choose y one + + align:start position:0% +that row so Y is going to choose y one + + + align:start position:0% +that row so Y is going to choose y one +the first column pretty often not all + + align:start position:0% +the first column pretty often not all + + + align:start position:0% +the first column pretty often not all +the time because what happens if he just + + align:start position:0% +the time because what happens if he just + + + align:start position:0% +the time because what happens if he just +if Y chooses this column all the time + + align:start position:0% +if Y chooses this column all the time + + + align:start position:0% +if Y chooses this column all the time +then X will choose this row and only the + + align:start position:0% +then X will choose this row and only the + + + align:start position:0% +then X will choose this row and only the +payoff will only be one so that things + + align:start position:0% +payoff will only be one so that things + + + align:start position:0% +payoff will only be one so that things +went downhill for why they're so so this + + align:start position:0% +went downhill for why they're so so this + + + align:start position:0% +went downhill for why they're so so this +is not a saddle point and what do we do + + align:start position:0% + + + + align:start position:0% + +mixed strategy which is why we'll choose + + align:start position:0% +mixed strategy which is why we'll choose + + + align:start position:0% +mixed strategy which is why we'll choose +the two columns with some probabilities + + align:start position:0% +the two columns with some probabilities + + + align:start position:0% +the two columns with some probabilities +that add to one + + align:start position:0% +that add to one + + + align:start position:0% +that add to one +so so the BIA so there be a third + + align:start position:0% +so so the BIA so there be a third + + + align:start position:0% +so so the BIA so there be a third +possibility that px 1 and one I'm sorry + + align:start position:0% +possibility that px 1 and one I'm sorry + + + align:start position:0% +possibility that px 1 and one I'm sorry +py 1 P times this column and 1 minus P + + align:start position:0% +py 1 P times this column and 1 minus P + + + align:start position:0% +py 1 P times this column and 1 minus P +times the second column so that'll be P + + align:start position:0% +times the second column so that'll be P + + + align:start position:0% +times the second column so that'll be P +plus 1 minus P times 8 and 4p plus + + align:start position:0% +plus 1 minus P times 8 and 4p plus + + + align:start position:0% +plus 1 minus P times 8 and 4p plus +one minus P times two that's that's this + + align:start position:0% +one minus P times two that's that's this + + + align:start position:0% +one minus P times two that's that's this +mixed column by by mixing his strategy + + align:start position:0% +mixed column by by mixing his strategy + + + align:start position:0% +mixed column by by mixing his strategy +why we have a strategy like a third + + align:start position:0% +why we have a strategy like a third + + + align:start position:0% +why we have a strategy like a third +person why three and of course the X is + + align:start position:0% +person why three and of course the X is + + + align:start position:0% +person why three and of course the X is +going to notice after a while what what + + align:start position:0% +going to notice after a while what what + + + align:start position:0% +going to notice after a while what what +what the strategy is this is an open + + align:start position:0% +what the strategy is this is an open + + + align:start position:0% +what the strategy is this is an open +competition you you're not hiding + + align:start position:0% +competition you you're not hiding + + + align:start position:0% +competition you you're not hiding +they're not able to hide anything you + + align:start position:0% +they're not able to hide anything you + + + align:start position:0% +they're not able to hide anything you +might take well maybe Y will jump around + + align:start position:0% +might take well maybe Y will jump around + + + align:start position:0% +might take well maybe Y will jump around +but that's foolishness Y is going to end + + align:start position:0% +but that's foolishness Y is going to end + + + align:start position:0% +but that's foolishness Y is going to end +up finding the best choice of P between + + align:start position:0% +up finding the best choice of P between + + + align:start position:0% +up finding the best choice of P between +0 & 1 + + align:start position:0% +0 & 1 + + + align:start position:0% +0 & 1 +and it will actually be between 0 & 1 + + align:start position:0% +and it will actually be between 0 & 1 + + + align:start position:0% +and it will actually be between 0 & 1 +because the extreme strategies of column + + align:start position:0% +because the extreme strategies of column + + + align:start position:0% +because the extreme strategies of column +1 and column 2 didn't or not winners but + + align:start position:0% +1 and column 2 didn't or not winners but + + + align:start position:0% +1 and column 2 didn't or not winners but +now X is going to do the same thing P X + + align:start position:0% +now X is going to do the same thing P X + + + align:start position:0% +now X is going to do the same thing P X +1 he's gonna he or she is going to + + align:start position:0% +1 he's gonna he or she is going to + + + align:start position:0% +1 he's gonna he or she is going to +combine those rows so so this would be P + + align:start position:0% +combine those rows so so this would be P + + + align:start position:0% +combine those rows so so this would be P +1 for the first row and 1 sorry P oh I + + align:start position:0% +1 for the first row and 1 sorry P oh I + + + align:start position:0% +1 for the first row and 1 sorry P oh I +better choose another number what's uh + + align:start position:0% +better choose another number what's uh + + + align:start position:0% +better choose another number what's uh +what's another letter than P Q okay Q + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so so this role was a combination of + + align:start position:0% +so so this role was a combination of + + + align:start position:0% +so so this role was a combination of +those rows so it's Q plus one minus Q + + align:start position:0% +those rows so it's Q plus one minus Q + + + align:start position:0% +those rows so it's Q plus one minus Q +times four in the first position and + + align:start position:0% +times four in the first position and + + + align:start position:0% +times four in the first position and +eight plus P times 8 and 1 minus the P + + align:start position:0% +eight plus P times 8 and 1 minus the P + + + align:start position:0% +eight plus P times 8 and 1 minus the P +and Q times 8 2 times 8 and 1 minus Q + + align:start position:0% +and Q times 8 2 times 8 and 1 minus Q + + + align:start position:0% +and Q times 8 2 times 8 and 1 minus Q +times 2 + + align:start position:0% +times 2 + + + align:start position:0% +times 2 +I'm sorry that I've written this too + + align:start position:0% +I'm sorry that I've written this too + + + align:start position:0% +I'm sorry that I've written this too +small but but what's going to happen + + align:start position:0% + + + + align:start position:0% + +what's going to determine P and Q and + + align:start position:0% +what's going to determine P and Q and + + + align:start position:0% +what's going to determine P and Q and +solve the game well if these are equal + + align:start position:0% +solve the game well if these are equal + + + align:start position:0% +solve the game well if these are equal +then what happens then X is okay with + + align:start position:0% +then what happens then X is okay with + + + align:start position:0% +then what happens then X is okay with +either one doesn't X has nothing to + + align:start position:0% +either one doesn't X has nothing to + + + align:start position:0% +either one doesn't X has nothing to +choose if those are equal and and Y is + + align:start position:0% +choose if those are equal and and Y is + + + align:start position:0% +choose if those are equal and and Y is +staying with this mixed strategy which + + align:start position:0% +staying with this mixed strategy which + + + align:start position:0% +staying with this mixed strategy which +gives him this third combination column + + align:start position:0% +gives him this third combination column + + + align:start position:0% +gives him this third combination column +then X is good now you might say well + + align:start position:0% +then X is good now you might say well + + + align:start position:0% +then X is good now you might say well +then X would do what it wanted but X + + align:start position:0% +then X would do what it wanted but X + + + align:start position:0% +then X would do what it wanted but X +couldn't do what it wanted if X doesn't + + align:start position:0% +couldn't do what it wanted if X doesn't + + + align:start position:0% +couldn't do what it wanted if X doesn't +stick with the optimal strategy Q for X + + align:start position:0% +stick with the optimal strategy Q for X + + + align:start position:0% +stick with the optimal strategy Q for X +then Y will take advantage so that you + + align:start position:0% +then Y will take advantage so that you + + + align:start position:0% +then Y will take advantage so that you +really the game settles down to once so + + align:start position:0% +really the game settles down to once so + + + align:start position:0% +really the game settles down to once so +so these should be equal so when the + + align:start position:0% +so these should be equal so when the + + + align:start position:0% +so these should be equal so when the +when those are equal what do I get IP it + + align:start position:0% +when those are equal what do I get IP it + + + align:start position:0% +when those are equal what do I get IP it +looks like I have 8 minus minus 7p there + + align:start position:0% +looks like I have 8 minus minus 7p there + + + align:start position:0% +looks like I have 8 minus minus 7p there +for the first one and here I have for P + + align:start position:0% +for the first one and here I have for P + + + align:start position:0% +for the first one and here I have for P +minus 2 P is 2 P plus 1 did I get that + + align:start position:0% +minus 2 P is 2 P plus 1 did I get that + + + align:start position:0% +minus 2 P is 2 P plus 1 did I get that +possibly right + + align:start position:0% + + + + align:start position:0% + +- for P - 2 P is the to peak and always + + align:start position:0% +- for P - 2 P is the to peak and always + + + align:start position:0% +- for P - 2 P is the to peak and always +- yeah okay so those are equal and that + + align:start position:0% +- yeah okay so those are equal and that + + + align:start position:0% +- yeah okay so those are equal and that +tells me that 9p is 6 and P is 2/3 so + + align:start position:0% +tells me that 9p is 6 and P is 2/3 so + + + align:start position:0% +tells me that 9p is 6 and P is 2/3 so +that turned out that the best strategy + + align:start position:0% +that turned out that the best strategy + + + align:start position:0% +that turned out that the best strategy +for y is 2/3 on the first column which + + align:start position:0% +for y is 2/3 on the first column which + + + align:start position:0% +for y is 2/3 on the first column which +didn't look so promising and 1/3 on the + + align:start position:0% +didn't look so promising and 1/3 on the + + + align:start position:0% +didn't look so promising and 1/3 on the +second and by that by creating that + + align:start position:0% +second and by that by creating that + + + align:start position:0% +second and by that by creating that +strategy what what do these numbers come + + align:start position:0% +strategy what what do these numbers come + + + align:start position:0% +strategy what what do these numbers come +out to be and they're supposed to come + + align:start position:0% +out to be and they're supposed to come + + + align:start position:0% +out to be and they're supposed to come +out equal so for P Plus so 4 times 2/3 + + align:start position:0% +out equal so for P Plus so 4 times 2/3 + + + align:start position:0% +out equal so for P Plus so 4 times 2/3 +is 8/3 plus 1 minus P is 1/3 x plus 2/3 + + align:start position:0% +is 8/3 plus 1 minus P is 1/3 x plus 2/3 + + + align:start position:0% +is 8/3 plus 1 minus P is 1/3 x plus 2/3 +is 10 thirds so I think that this is ten + + align:start position:0% +is 10 thirds so I think that this is ten + + + align:start position:0% +is 10 thirds so I think that this is ten +thirds and if that one isn't ten thirds + + align:start position:0% +thirds and if that one isn't ten thirds + + + align:start position:0% +thirds and if that one isn't ten thirds +I'm very surprised so it's 2/3 + + align:start position:0% +I'm very surprised so it's 2/3 + + + align:start position:0% +I'm very surprised so it's 2/3 +well is it for P - P yeah tell me + + align:start position:0% +well is it for P - P yeah tell me + + + align:start position:0% +well is it for P - P yeah tell me +they're the same did I set them equal + + align:start position:0% +they're the same did I set them equal + + + align:start position:0% +they're the same did I set them equal +yeah I set them equal to find peace so + + align:start position:0% +yeah I set them equal to find peace so + + + align:start position:0% +yeah I set them equal to find peace so +they have to be the same except for + + align:start position:0% +they have to be the same except for + + + align:start position:0% +they have to be the same except for +instructor mistakes which never happened + + align:start position:0% +instructor mistakes which never happened + + + align:start position:0% +instructor mistakes which never happened +ok so those are those should be equal + + align:start position:0% +ok so those are those should be equal + + + align:start position:0% +ok so those are those should be equal +then X has no choice oh no way to do + + align:start position:0% +then X has no choice oh no way to do + + + align:start position:0% +then X has no choice oh no way to do +better choose these columns that he + + align:start position:0% +better choose these columns that he + + + align:start position:0% +better choose these columns that he +can't choose those columns free those + + align:start position:0% +can't choose those columns free those + + + align:start position:0% +can't choose those columns free those +roads freely because Y could take + + align:start position:0% +roads freely because Y could take + + + align:start position:0% +roads freely because Y could take +advantage unless so this would tell this + + align:start position:0% +advantage unless so this would tell this + + + align:start position:0% +advantage unless so this would tell this +would give the best strategy for q4 for + + align:start position:0% +would give the best strategy for q4 for + + + align:start position:0% +would give the best strategy for q4 for +the sorry the best q4 for X yep + + align:start position:0% +the sorry the best q4 for X yep + + + align:start position:0% +the sorry the best q4 for X yep +yes do you see that picture now there + + align:start position:0% +yes do you see that picture now there + + + align:start position:0% +yes do you see that picture now there +could be other it could be a much bigger + + align:start position:0% +could be other it could be a much bigger + + + align:start position:0% +could be other it could be a much bigger +matrix of course there could be other + + align:start position:0% +matrix of course there could be other + + + align:start position:0% +matrix of course there could be other +columns suppose there was a 0 0 column + + align:start position:0% +columns suppose there was a 0 0 column + + + align:start position:0% +columns suppose there was a 0 0 column +what difference what would be the effect + + align:start position:0% +what difference what would be the effect + + + align:start position:0% +what difference what would be the effect +on the optimal strategy of how + + align:start position:0% +on the optimal strategy of how + + + align:start position:0% +on the optimal strategy of how +additional column that additional option + + align:start position:0% +additional column that additional option + + + align:start position:0% +additional column that additional option +for y3 well he wouldn't take okay so + + align:start position:0% +for y3 well he wouldn't take okay so + + + align:start position:0% +for y3 well he wouldn't take okay so +let's make it more tempting 10 10 10 + + align:start position:0% +let's make it more tempting 10 10 10 + + + align:start position:0% +let's make it more tempting 10 10 10 +okay + + align:start position:0% +okay + + + align:start position:0% +okay +oh he wouldn't tell you that right yeah + + align:start position:0% +oh he wouldn't tell you that right yeah + + + align:start position:0% +oh he wouldn't tell you that right yeah +that was not so well I'm not sure what + + align:start position:0% +that was not so well I'm not sure what + + + align:start position:0% +that was not so well I'm not sure what +I'm trying to say here yeah + + align:start position:0% +I'm trying to say here yeah + + + align:start position:0% +I'm trying to say here yeah +there certainly could be there could be + + align:start position:0% +there certainly could be there could be + + + align:start position:0% +there certainly could be there could be +rows that are columns or rows for X that + + align:start position:0% +rows that are columns or rows for X that + + + align:start position:0% +rows that are columns or rows for X that +don't enter the mixed up for the optimal + + align:start position:0% +don't enter the mixed up for the optimal + + + align:start position:0% +don't enter the mixed up for the optimal +mix strategy and make strategy of some + + align:start position:0% +mix strategy and make strategy of some + + + align:start position:0% +mix strategy and make strategy of some +combination of strategies some + + align:start position:0% +combination of strategies some + + + align:start position:0% +combination of strategies some +combination of pure strategies like + + align:start position:0% +combination of pure strategies like + + + align:start position:0% +combination of pure strategies like +choose this column choose this row but + + align:start position:0% +choose this column choose this row but + + + align:start position:0% +choose this column choose this row but +some some columns may not or rows may + + align:start position:0% +some some columns may not or rows may + + + align:start position:0% +some some columns may not or rows may +not show up in the best mixture so I'll + + align:start position:0% +not show up in the best mixture so I'll + + + align:start position:0% +not show up in the best mixture so I'll +I won't complete that partial so like + + align:start position:0% +I won't complete that partial so like + + + align:start position:0% +I won't complete that partial so like +that okay so what do we do you see that + + align:start position:0% +that okay so what do we do you see that + + + align:start position:0% +that okay so what do we do you see that +we have a duality theorem we first of + + align:start position:0% +we have a duality theorem we first of + + + align:start position:0% +we have a duality theorem we first of +all you could write that as a linear + + align:start position:0% +all you could write that as a linear + + + align:start position:0% +all you could write that as a linear +program the unknown is P for X you know + + align:start position:0% +program the unknown is P for X you know + + + align:start position:0% +program the unknown is P for X you know +for y the unknown is Q for X so actually + + align:start position:0% +for y the unknown is Q for X so actually + + + align:start position:0% +for y the unknown is Q for X so actually +just have one unknown in this simple + + align:start position:0% +just have one unknown in this simple + + + align:start position:0% +just have one unknown in this simple +problem but for this small problem but + + align:start position:0% +problem but for this small problem but + + + align:start position:0% +problem but for this small problem but +you have a minimization and maximization + + align:start position:0% +you have a minimization and maximization + + + align:start position:0% +you have a minimization and maximization +they meet at the optimum and the duality + + align:start position:0% +they meet at the optimum and the duality + + + align:start position:0% +they meet at the optimum and the duality +theorem becomes the the theorem for for + + align:start position:0% +theorem becomes the the theorem for for + + + align:start position:0% +theorem becomes the the theorem for for +two person games linear programming + + align:start position:0% +two person games linear programming + + + align:start position:0% +two person games linear programming +matches two person games the point about + + align:start position:0% +matches two person games the point about + + + align:start position:0% +matches two person games the point about +two persons is very important three + + align:start position:0% +two persons is very important three + + + align:start position:0% +two persons is very important three +person games are incredibly complicated + + align:start position:0% +person games are incredibly complicated + + + align:start position:0% +person games are incredibly complicated +no no sería that this simple level would + + align:start position:0% +no no sería that this simple level would + + + align:start position:0% +no no sería that this simple level would +would solve three person games so that's + + align:start position:0% +would solve three person games so that's + + + align:start position:0% +would solve three person games so that's +where John Nash's Nobel Prize comes into + + align:start position:0% +where John Nash's Nobel Prize comes into + + + align:start position:0% +where John Nash's Nobel Prize comes into +the picture + + align:start position:0% +the picture + + + align:start position:0% +the picture +so his Nobel Prize was in economics + + align:start position:0% +so his Nobel Prize was in economics + + + align:start position:0% +so his Nobel Prize was in economics +because of the wide applications but he + + align:start position:0% +because of the wide applications but he + + + align:start position:0% +because of the wide applications but he +was able to analyze the problem of and + + align:start position:0% +was able to analyze the problem of and + + + align:start position:0% +was able to analyze the problem of and +for functions more than four matrices of + + align:start position:0% +for functions more than four matrices of + + + align:start position:0% +for functions more than four matrices of +three person or in person games so you + + align:start position:0% +three person or in person games so you + + + align:start position:0% +three person or in person games so you +know the story of John Nash the the book + + align:start position:0% +know the story of John Nash the the book + + + align:start position:0% +know the story of John Nash the the book +A Beautiful Mind and the movie A + + align:start position:0% +A Beautiful Mind and the movie A + + + align:start position:0% +A Beautiful Mind and the movie A +Beautiful Mind so it's one of those + + align:start position:0% +Beautiful Mind so it's one of those + + + align:start position:0% +Beautiful Mind so it's one of those +movies that involves MIT because he was + + align:start position:0% +movies that involves MIT because he was + + + align:start position:0% +movies that involves MIT because he was +here but you can't recognize anything + + align:start position:0% +here but you can't recognize anything + + + align:start position:0% +here but you can't recognize anything +about MIT the movie it's like Good Will + + align:start position:0% +about MIT the movie it's like Good Will + + + align:start position:0% +about MIT the movie it's like Good Will +Hunting you're you're maybe in some + + align:start position:0% +Hunting you're you're maybe in some + + + align:start position:0% +Hunting you're you're maybe in some +basement of some remote building but + + align:start position:0% +basement of some remote building but + + + align:start position:0% +basement of some remote building but +anyway it was of course a tragic tragic + + align:start position:0% +anyway it was of course a tragic tragic + + + align:start position:0% +anyway it was of course a tragic tragic +and then sure and wonderful and then + + align:start position:0% +and then sure and wonderful and then + + + align:start position:0% +and then sure and wonderful and then +tragic again for its he had so when I + + align:start position:0% +tragic again for its he had so when I + + + align:start position:0% +tragic again for its he had so when I +met him he was going to teach linear + + align:start position:0% +met him he was going to teach linear + + + align:start position:0% +met him he was going to teach linear +algebra one section but I never + + align:start position:0% +algebra one section but I never + + + align:start position:0% +algebra one section but I never +developed his that was when he was his + + align:start position:0% +developed his that was when he was his + + + align:start position:0% +developed his that was when he was his +mental state was going downhill and he + + align:start position:0% +mental state was going downhill and he + + + align:start position:0% +mental state was going downhill and he +moved to Princeton and and just stayed + + align:start position:0% +moved to Princeton and and just stayed + + + align:start position:0% +moved to Princeton and and just stayed +and then the wonderful thing was that he + + align:start position:0% +and then the wonderful thing was that he + + + align:start position:0% +and then the wonderful thing was that he +improved and then the very sad thing was + + align:start position:0% +improved and then the very sad thing was + + + align:start position:0% +improved and then the very sad thing was +its death in a car accident on the way + + align:start position:0% +its death in a car accident on the way + + + align:start position:0% +its death in a car accident on the way +home from from the Nobel Prize + + align:start position:0% +home from from the Nobel Prize + + + align:start position:0% +home from from the Nobel Prize +so quite a story on an amazing story + + align:start position:0% +so quite a story on an amazing story + + + align:start position:0% +so quite a story on an amazing story +yep okay so that's specific optimization + + align:start position:0% +yep okay so that's specific optimization + + + align:start position:0% +yep okay so that's specific optimization +problems linear programming and + + align:start position:0% +problems linear programming and + + + align:start position:0% +problems linear programming and +two-person games and I hope that Friday + + align:start position:0% +two-person games and I hope that Friday + + + align:start position:0% +two-person games and I hope that Friday +it will be professor swath anyway the + + align:start position:0% +it will be professor swath anyway the + + + align:start position:0% +it will be professor swath anyway the +lecture will certainly be about + + align:start position:0% +lecture will certainly be about + + + align:start position:0% +lecture will certainly be about +stochastic gradient descent good thanks \ No newline at end of file diff --git a/ffOGEN5WZu4.txt b/ffOGEN5WZu4.txt new file mode 100644 index 0000000000000000000000000000000000000000..c829d26a3660bcfcbe5cc4a348fc2ce6e062f719 --- /dev/null +++ b/ffOGEN5WZu4.txt @@ -0,0 +1,227 @@ +align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +in this case study we're going to + + align:start position:0% +in this case study we're going to + + + align:start position:0% +in this case study we're going to +quickly look at how an image of your + + align:start position:0% +quickly look at how an image of your + + + align:start position:0% +quickly look at how an image of your +apparatus could become an interesting + + align:start position:0% +apparatus could become an interesting + + + align:start position:0% +apparatus could become an interesting +photograph to submit for a cover or used + + align:start position:0% +photograph to submit for a cover or used + + + align:start position:0% +photograph to submit for a cover or used +as a figure here we're suggesting a + + align:start position:0% +as a figure here we're suggesting a + + + align:start position:0% +as a figure here we're suggesting a +process now because I couldn't + + align:start position:0% +process now because I couldn't + + + align:start position:0% +process now because I couldn't +photograph the experiment as it was + + align:start position:0% +photograph the experiment as it was + + + align:start position:0% +photograph the experiment as it was +going on because it was a closed system + + align:start position:0% +going on because it was a closed system + + + align:start position:0% +going on because it was a closed system +I made an initial image of the apparatus + + align:start position:0% +I made an initial image of the apparatus + + + align:start position:0% +I made an initial image of the apparatus +used in the research the wires are + + align:start position:0% +used in the research the wires are + + + align:start position:0% +used in the research the wires are +heated to vaporized polymer material + + align:start position:0% +heated to vaporized polymer material + + + align:start position:0% +heated to vaporized polymer material +which is then deposited onto chips as + + align:start position:0% +which is then deposited onto chips as + + + align:start position:0% +which is then deposited onto chips as +you see here I first thought I would + + align:start position:0% +you see here I first thought I would + + + align:start position:0% +you see here I first thought I would +make a nice image for a cover leaving + + align:start position:0% +make a nice image for a cover leaving + + + align:start position:0% +make a nice image for a cover leaving +room for the journal's logo as it turned + + align:start position:0% +room for the journal's logo as it turned + + + align:start position:0% +room for the journal's logo as it turned +out that image was used for the MIT news + + align:start position:0% +out that image was used for the MIT news + + + align:start position:0% +out that image was used for the MIT news +page I then decided to add another piece + + align:start position:0% +page I then decided to add another piece + + + align:start position:0% +page I then decided to add another piece +of their apparatus to fill the whole + + align:start position:0% +of their apparatus to fill the whole + + + align:start position:0% +of their apparatus to fill the whole +image in the end we did submit this one + + align:start position:0% +image in the end we did submit this one + + + align:start position:0% +image in the end we did submit this one +for the cover but it didn't get it what + + align:start position:0% +for the cover but it didn't get it what + + + align:start position:0% +for the cover but it didn't get it what +we did get was something called the + + align:start position:0% +we did get was something called the + + + align:start position:0% +we did get was something called the +frest piece in the journal and + + align:start position:0% +frest piece in the journal and + + + align:start position:0% +frest piece in the journal and +surprisingly they preferred this + + align:start position:0% +surprisingly they preferred this + + + align:start position:0% +surprisingly they preferred this +inverted image which I made just for fun + + align:start position:0% +inverted image which I made just for fun + + + align:start position:0% +inverted image which I made just for fun +rather than the original frankly I + + align:start position:0% +rather than the original frankly I + + + align:start position:0% +rather than the original frankly I +personally preferred the first one but + + align:start position:0% +personally preferred the first one but + + + align:start position:0% +personally preferred the first one but +you know you just never know people's + + align:start position:0% +you know you just never know people's + + + align:start position:0% +you know you just never know people's +taste \ No newline at end of file diff --git a/g01r2YRH9ok.txt b/g01r2YRH9ok.txt new file mode 100644 index 0000000000000000000000000000000000000000..98eb42b54de07a68d0d18af5a637dd0a860a1f9a --- /dev/null +++ b/g01r2YRH9ok.txt @@ -0,0 +1,6251 @@ +align:start position:0% + +the following content is provided by MIT + + align:start position:0% +the following content is provided by MIT + + + align:start position:0% +the following content is provided by MIT +open courseware under a Creative Commons + + align:start position:0% +open courseware under a Creative Commons + + + align:start position:0% +open courseware under a Creative Commons +license additional information about our + + align:start position:0% +license additional information about our + + + align:start position:0% +license additional information about our +license and MIT open courseware in + + align:start position:0% +license and MIT open courseware in + + + align:start position:0% +license and MIT open courseware in +general is available at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu all right so we have a few + + align:start position:0% +ocw.mit.edu all right so we have a few + + + align:start position:0% +ocw.mit.edu all right so we have a few +more uh PowerPoint things before I'm + + align:start position:0% +more uh PowerPoint things before I'm + + + align:start position:0% +more uh PowerPoint things before I'm +going to attempt using the board um so + + align:start position:0% +going to attempt using the board um so + + + align:start position:0% +going to attempt using the board um so +again we're in the transition metal unit + + align:start position:0% +again we're in the transition metal unit + + + align:start position:0% +again we're in the transition metal unit +and today we're going to introduce + + align:start position:0% +and today we're going to introduce + + + align:start position:0% +and today we're going to introduce +something called Crystal field Theory + + align:start position:0% +something called Crystal field Theory + + + align:start position:0% +something called Crystal field Theory +and this is in chapter 16 in your + + align:start position:0% + + + + align:start position:0% + +book so let me just tell you about two + + align:start position:0% +book so let me just tell you about two + + + align:start position:0% +book so let me just tell you about two +different theories and again chemistry + + align:start position:0% +different theories and again chemistry + + + align:start position:0% +different theories and again chemistry +is an experimental science we collect + + align:start position:0% +is an experimental science we collect + + + align:start position:0% +is an experimental science we collect +data and then we try to come up with + + align:start position:0% +data and then we try to come up with + + + align:start position:0% +data and then we try to come up with +theories that explain the data so the + + align:start position:0% +theories that explain the data so the + + + align:start position:0% +theories that explain the data so the +theories aren't sort of 100% and some + + align:start position:0% +theories aren't sort of 100% and some + + + align:start position:0% +theories aren't sort of 100% and some +are more simple and some are more + + align:start position:0% +are more simple and some are more + + + align:start position:0% +are more simple and some are more +complicated to try to explain what we + + align:start position:0% +complicated to try to explain what we + + + align:start position:0% +complicated to try to explain what we +observe and some of these theories + + align:start position:0% +observe and some of these theories + + + align:start position:0% +observe and some of these theories +although they're pretty simple + + align:start position:0% +although they're pretty simple + + + align:start position:0% +although they're pretty simple +approximations of what's really going on + + align:start position:0% +approximations of what's really going on + + + align:start position:0% +approximations of what's really going on +do a pretty good job job of explaining + + align:start position:0% +do a pretty good job job of explaining + + + align:start position:0% +do a pretty good job job of explaining +the things that we are + + align:start position:0% +the things that we are + + + align:start position:0% +the things that we are +observing all right so there two there + + align:start position:0% +observing all right so there two there + + + align:start position:0% +observing all right so there two there +are two different kinds of theories that + + align:start position:0% +are two different kinds of theories that + + + align:start position:0% +are two different kinds of theories that +you'll hear about with transition metals + + align:start position:0% +you'll hear about with transition metals + + + align:start position:0% +you'll hear about with transition metals +you'll hear about Crystal field Theory + + align:start position:0% +you'll hear about Crystal field Theory + + + align:start position:0% +you'll hear about Crystal field Theory +and Lian field theories and so these + + align:start position:0% +and Lian field theories and so these + + + align:start position:0% +and Lian field theories and so these +were again developed to explain certain + + align:start position:0% +were again developed to explain certain + + + align:start position:0% +were again developed to explain certain +types of properties of coordination + + align:start position:0% +types of properties of coordination + + + align:start position:0% +types of properties of coordination +complexes of transition metals so there + + align:start position:0% +complexes of transition metals so there + + + align:start position:0% +complexes of transition metals so there +was Observe data and then people tried + + align:start position:0% +was Observe data and then people tried + + + align:start position:0% +was Observe data and then people tried +to think about how you could rationalize + + align:start position:0% +to think about how you could rationalize + + + align:start position:0% +to think about how you could rationalize +what was observed + + align:start position:0% + + + + align:start position:0% + +so the basic idea behind these theories + + align:start position:0% +so the basic idea behind these theories + + + align:start position:0% +so the basic idea behind these theories +is that um if you have your metal Ion + + align:start position:0% +is that um if you have your metal Ion + + + align:start position:0% +is that um if you have your metal Ion +with its given oxidation number and it's + + align:start position:0% +with its given oxidation number and it's + + + align:start position:0% +with its given oxidation number and it's +in the center of a coordination + + align:start position:0% +in the center of a coordination + + + align:start position:0% +in the center of a coordination +sphere the energy levels of the D + + align:start position:0% +sphere the energy levels of the D + + + align:start position:0% +sphere the energy levels of the D +orbitals for that particular metal are + + align:start position:0% +orbitals for that particular metal are + + + align:start position:0% +orbitals for that particular metal are +going to be altered when lians are bound + + align:start position:0% +going to be altered when lians are bound + + + align:start position:0% +going to be altered when lians are bound +compared to sort of a free a free system + + align:start position:0% +compared to sort of a free a free system + + + align:start position:0% +compared to sort of a free a free system +so The Binding of lians around that + + align:start position:0% +so The Binding of lians around that + + + align:start position:0% +so The Binding of lians around that +metal where there are those D orbitals + + align:start position:0% +metal where there are those D orbitals + + + align:start position:0% +metal where there are those D orbitals +associated with that metal is going to + + align:start position:0% +associated with that metal is going to + + + align:start position:0% +associated with that metal is going to +have an effect and create special + + align:start position:0% + + + + align:start position:0% + +properties so Crystal field Theory which + + align:start position:0% +properties so Crystal field Theory which + + + align:start position:0% +properties so Crystal field Theory which +is what we're going to be talking about + + align:start position:0% +is what we're going to be talking about + + + align:start position:0% +is what we're going to be talking about +is based on an ionic description + + align:start position:0% +is based on an ionic description + + + align:start position:0% +is based on an ionic description +basically you're going to be considering + + align:start position:0% +basically you're going to be considering + + + align:start position:0% +basically you're going to be considering +your lians as negative point charges a + + align:start position:0% +your lians as negative point charges a + + + align:start position:0% +your lians as negative point charges a +negative charge and you're going to ask + + align:start position:0% +negative charge and you're going to ask + + + align:start position:0% +negative charge and you're going to ask +the question is that negative charge + + align:start position:0% +the question is that negative charge + + + align:start position:0% +the question is that negative charge +pointed toward a d orbital if so that'll + + align:start position:0% +pointed toward a d orbital if so that'll + + + align:start position:0% +pointed toward a d orbital if so that'll +be repulsive and that's going to have an + + align:start position:0% +be repulsive and that's going to have an + + + align:start position:0% +be repulsive and that's going to have an +effect so + + align:start position:0% +effect so + + + align:start position:0% +effect so +uh ligan field Theory includes coent as + + align:start position:0% +uh ligan field Theory includes coent as + + + align:start position:0% +uh ligan field Theory includes coent as +well as ionic descriptions so um it is a + + align:start position:0% +well as ionic descriptions so um it is a + + + align:start position:0% +well as ionic descriptions so um it is a +more powerful uh Theory and it it can + + align:start position:0% +more powerful uh Theory and it it can + + + align:start position:0% +more powerful uh Theory and it it can +describe things a little bit better um + + align:start position:0% +describe things a little bit better um + + + align:start position:0% +describe things a little bit better um +but it's uh we don't have enough time to + + align:start position:0% +but it's uh we don't have enough time to + + + align:start position:0% +but it's uh we don't have enough time to +cover it here and if you're interested + + align:start position:0% +cover it here and if you're interested + + + align:start position:0% +cover it here and if you're interested +in transition metals you'll probably go + + align:start position:0% +in transition metals you'll probably go + + + align:start position:0% +in transition metals you'll probably go +on and take another chemistry course + + align:start position:0% +on and take another chemistry course + + + align:start position:0% +on and take another chemistry course +called 503 which is inorganic chemistry + + align:start position:0% +called 503 which is inorganic chemistry + + + align:start position:0% +called 503 which is inorganic chemistry +um so at this point we're just going to + + align:start position:0% +um so at this point we're just going to + + + align:start position:0% +um so at this point we're just going to +be doing the more Simple Theory which + + align:start position:0% +be doing the more Simple Theory which + + + align:start position:0% +be doing the more Simple Theory which +just considers the ionic descriptions + + align:start position:0% +just considers the ionic descriptions + + + align:start position:0% +just considers the ionic descriptions +but it does pretty well you can explain + + align:start position:0% +but it does pretty well you can explain + + + align:start position:0% +but it does pretty well you can explain +some some things with it but you should + + align:start position:0% +some some things with it but you should + + + align:start position:0% +some some things with it but you should +be aware that this is not uh sort of the + + align:start position:0% +be aware that this is not uh sort of the + + + align:start position:0% +be aware that this is not uh sort of the +uh the most that you can do a little bit + + align:start position:0% +uh the most that you can do a little bit + + + align:start position:0% +uh the most that you can do a little bit +better with another theory so you should + + align:start position:0% +better with another theory so you should + + + align:start position:0% +better with another theory so you should +just be aware of that that this is + + align:start position:0% +just be aware of that that this is + + + align:start position:0% +just be aware of that that this is +really the most simplistic kind of a + + align:start position:0% +really the most simplistic kind of a + + + align:start position:0% +really the most simplistic kind of a +representation or Theory to explain some + + align:start position:0% +representation or Theory to explain some + + + align:start position:0% +representation or Theory to explain some +of the properties of of uh coordination + + align:start position:0% +of the properties of of uh coordination + + + align:start position:0% +of the properties of of uh coordination +complexes all right so all of these + + align:start position:0% +complexes all right so all of these + + + align:start position:0% +complexes all right so all of these +theories uh require you to think in + + align:start position:0% +theories uh require you to think in + + + align:start position:0% +theories uh require you to think in +three diens mentions about de orbitals + + align:start position:0% +three diens mentions about de orbitals + + + align:start position:0% +three diens mentions about de orbitals +because they're all about the + + align:start position:0% +because they're all about the + + + align:start position:0% +because they're all about the +interactions with lians either calent or + + align:start position:0% +interactions with lians either calent or + + + align:start position:0% +interactions with lians either calent or +or um ionic interactions but they're all + + align:start position:0% +or um ionic interactions but they're all + + + align:start position:0% +or um ionic interactions but they're all +about the interactions of lians with + + align:start position:0% +about the interactions of lians with + + + align:start position:0% +about the interactions of lians with +those D orbitals so we I mentioned last + + align:start position:0% +those D orbitals so we I mentioned last + + + align:start position:0% +those D orbitals so we I mentioned last +time that you need to know the shapes of + + align:start position:0% +time that you need to know the shapes of + + + align:start position:0% +time that you need to know the shapes of +the D orbitals and you need to be able + + align:start position:0% +the D orbitals and you need to be able + + + align:start position:0% +the D orbitals and you need to be able +to draw them to some uh limited uh + + align:start position:0% +to draw them to some uh limited uh + + + align:start position:0% +to draw them to some uh limited uh +ability so we went through the names of + + align:start position:0% +ability so we went through the names of + + + align:start position:0% +ability so we went through the names of +the D orbitals last time let's just + + align:start position:0% +the D orbitals last time let's just + + + align:start position:0% +the D orbitals last time let's just +review it now because we're going to be + + align:start position:0% +review it now because we're going to be + + + align:start position:0% +review it now because we're going to be +talking about this more today so uh what + + align:start position:0% +talking about this more today so uh what + + + align:start position:0% +talking about this more today so uh what +is this guy up here + + align:start position:0% +is this guy up here + + + align:start position:0% +is this guy up here +that's DZ squ and here's our reference + + align:start position:0% +that's DZ squ and here's our reference + + + align:start position:0% +that's DZ squ and here's our reference +frame so Z is up here a y along here and + + align:start position:0% +frame so Z is up here a y along here and + + + align:start position:0% +frame so Z is up here a y along here and +X is coming out toward you so what about + + align:start position:0% +X is coming out toward you so what about + + + align:start position:0% +X is coming out toward you so what about +this + + align:start position:0% +this + + + align:start position:0% +this +one yeah dx^ 2us y sared uh down here + + align:start position:0% +one yeah dx^ 2us y sared uh down here + + + align:start position:0% +one yeah dx^ 2us y sared uh down here +what's that + + align:start position:0% +what's that + + + align:start position:0% +what's that +one yeah dxy so we're the the uh + + align:start position:0% +one yeah dxy so we're the the uh + + + align:start position:0% +one yeah dxy so we're the the uh +amplitudes are 45° off the axis in the + + align:start position:0% +amplitudes are 45° off the axis in the + + + align:start position:0% +amplitudes are 45° off the axis in the +XY plane + + align:start position:0% +XY plane + + + align:start position:0% +XY plane +over here we have dyz so now we're along + + align:start position:0% +over here we have dyz so now we're along + + + align:start position:0% +over here we have dyz so now we're along +Z and uh the last one + + align:start position:0% + + + + align:start position:0% + +is yeah XZ over + + align:start position:0% +is yeah XZ over + + + align:start position:0% +is yeah XZ over +here all right so those are the five D + + align:start position:0% +here all right so those are the five D + + + align:start position:0% +here all right so those are the five D +orbitals that we'll be talking about a + + align:start position:0% +orbitals that we'll be talking about a + + + align:start position:0% +orbitals that we'll be talking about a +lot uh in the next few lectures all + + align:start position:0% +lot uh in the next few lectures all + + + align:start position:0% +lot uh in the next few lectures all +right so let me just show you this is + + align:start position:0% +right so let me just show you this is + + + align:start position:0% +right so let me just show you this is +all it's really threedimensional so + + align:start position:0% +all it's really threedimensional so + + + align:start position:0% +all it's really threedimensional so +let's take a look at the + + align:start position:0% +let's take a look at the + + + align:start position:0% +let's take a look at the +three-dimensional image of these uh of + + align:start position:0% +three-dimensional image of these uh of + + + align:start position:0% +three-dimensional image of these uh of +these D orbitals + + align:start position:0% +these D orbitals + + + align:start position:0% +these D orbitals +so this is a uh DZ Square this isn't in + + align:start position:0% +so this is a uh DZ Square this isn't in + + + align:start position:0% +so this is a uh DZ Square this isn't in +your handout obviously it's a movie um + + align:start position:0% +your handout obviously it's a movie um + + + align:start position:0% +your handout obviously it's a movie um +but you can sort of get a little better + + align:start position:0% +but you can sort of get a little better + + + align:start position:0% +but you can sort of get a little better +sense of the three dimensions + + align:start position:0% + + + + align:start position:0% + +here all right so the movie first + + align:start position:0% +here all right so the movie first + + + align:start position:0% +here all right so the movie first +rotates the axes I'm not sure why it + + align:start position:0% +rotates the axes I'm not sure why it + + + align:start position:0% +rotates the axes I'm not sure why it +does that um and then it's going to + + align:start position:0% +does that um and then it's going to + + + align:start position:0% +does that um and then it's going to +rotate the uh D orbitals so you can see + + align:start position:0% +rotate the uh D orbitals so you can see + + + align:start position:0% +rotate the uh D orbitals so you can see +the dut uh in the Middle with the hole + + align:start position:0% +the dut uh in the Middle with the hole + + + align:start position:0% +the dut uh in the Middle with the hole +and that the maximum amplitudes are + + align:start position:0% +and that the maximum amplitudes are + + + align:start position:0% +and that the maximum amplitudes are +along the Z axis here so this is DZ SAR + + align:start position:0% +along the Z axis here so this is DZ SAR + + + align:start position:0% +along the Z axis here so this is DZ SAR +and it's right along the orbitals are + + align:start position:0% +and it's right along the orbitals are + + + align:start position:0% +and it's right along the orbitals are +right along the Z axis which is + + align:start position:0% +right along the Z axis which is + + + align:start position:0% +right along the Z axis which is +important so now let's take a look at D + + align:start position:0% +important so now let's take a look at D + + + align:start position:0% +important so now let's take a look at D +x^2 minus + + align:start position:0% +x^2 minus + + + align:start position:0% +x^2 minus +y^2 and uh the important Point here is + + align:start position:0% +y^2 and uh the important Point here is + + + align:start position:0% +y^2 and uh the important Point here is +that the orbitals are directly on axis + + align:start position:0% +that the orbitals are directly on axis + + + align:start position:0% +that the orbitals are directly on axis +and the axes are the X and the Y so you + + align:start position:0% +and the axes are the X and the Y so you + + + align:start position:0% +and the axes are the X and the Y so you +can see how they're directly along those + + align:start position:0% +can see how they're directly along those + + + align:start position:0% +can see how they're directly along those +axes + + align:start position:0% + + + + align:start position:0% + +all right + + align:start position:0% +all right + + + align:start position:0% +all right +so here's the next one so here we have + + align:start position:0% +so here's the next one so here we have + + + align:start position:0% +so here's the next one so here we have +dxy and now the orbitals are not along + + align:start position:0% +dxy and now the orbitals are not along + + + align:start position:0% +dxy and now the orbitals are not along +the axes they're 45 degre in between so + + align:start position:0% +the axes they're 45 degre in between so + + + align:start position:0% +the axes they're 45 degre in between so +they're not along they're in between + + align:start position:0% +they're not along they're in between + + + align:start position:0% +they're not along they're in between +which is the key Point uh for this D + + align:start position:0% +which is the key Point uh for this D + + + align:start position:0% +which is the key Point uh for this D +orbital in terms of what we're going to + + align:start position:0% +orbital in terms of what we're going to + + + align:start position:0% +orbital in terms of what we're going to +be talking about + + align:start position:0% + + + + align:start position:0% + +now we have some amplitude along the Z + + align:start position:0% +now we have some amplitude along the Z + + + align:start position:0% +now we have some amplitude along the Z +axis we have Z and x and again the + + align:start position:0% +axis we have Z and x and again the + + + align:start position:0% +axis we have Z and x and again the +orbitals are 45 Dees off the + + align:start position:0% + + + + align:start position:0% + +axes and we have one + + align:start position:0% +axes and we have one + + + align:start position:0% +axes and we have one +more so now we have Dy Z again 45° + + align:start position:0% +more so now we have Dy Z again 45° + + + align:start position:0% +more so now we have Dy Z again 45° +off the + + align:start position:0% + + + + align:start position:0% + +axis all right so now you should have + + align:start position:0% +axis all right so now you should have + + + align:start position:0% +axis all right so now you should have +these sort of orbitals uh floating + + align:start position:0% +these sort of orbitals uh floating + + + align:start position:0% +these sort of orbitals uh floating +around inside your head and as we talk + + align:start position:0% +around inside your head and as we talk + + + align:start position:0% +around inside your head and as we talk +about bringing ligans in toward the + + align:start position:0% +about bringing ligans in toward the + + + align:start position:0% +about bringing ligans in toward the +orbitals you can think about how those + + align:start position:0% +orbitals you can think about how those + + + align:start position:0% +orbitals you can think about how those +ligans are coming in and what orbitals + + align:start position:0% +ligans are coming in and what orbitals + + + align:start position:0% +ligans are coming in and what orbitals +they going to be + + align:start position:0% + + + + align:start position:0% + +near so again Crystal field theory is + + align:start position:0% +near so again Crystal field theory is + + + align:start position:0% +near so again Crystal field theory is +just considering the ionic interactions + + align:start position:0% +just considering the ionic interactions + + + align:start position:0% +just considering the ionic interactions +and it's really considering the lians as + + align:start position:0% +and it's really considering the lians as + + + align:start position:0% +and it's really considering the lians as +negative point charges and so negative + + align:start position:0% +negative point charges and so negative + + + align:start position:0% +negative point charges and so negative +point charges are going to be repulsive + + align:start position:0% +point charges are going to be repulsive + + + align:start position:0% +point charges are going to be repulsive +with the D orbitals so D orbitals don't + + align:start position:0% +with the D orbitals so D orbitals don't + + + align:start position:0% +with the D orbitals so D orbitals don't +like it when you have this negatively + + align:start position:0% +like it when you have this negatively + + + align:start position:0% +like it when you have this negatively +charged ligan uh coming in and being + + align:start position:0% +charged ligan uh coming in and being + + + align:start position:0% +charged ligan uh coming in and being +near it will be repulsive uh near the D + + align:start position:0% +near it will be repulsive uh near the D + + + align:start position:0% +near it will be repulsive uh near the D +orbital so this is just another way to + + align:start position:0% +orbital so this is just another way to + + + align:start position:0% +orbital so this is just another way to +sort of draw that and we have our + + align:start position:0% +sort of draw that and we have our + + + align:start position:0% +sort of draw that and we have our +octahedral frame uh so here we're + + align:start position:0% +octahedral frame uh so here we're + + + align:start position:0% +octahedral frame uh so here we're +talking about an octahedral + + align:start position:0% + + + + align:start position:0% + +geometry and we can think about how + + align:start position:0% +geometry and we can think about how + + + align:start position:0% +geometry and we can think about how +lians are going to be affecting the D + + align:start position:0% +lians are going to be affecting the D + + + align:start position:0% +lians are going to be affecting the D +orbital in these various places if you + + align:start position:0% +orbital in these various places if you + + + align:start position:0% +orbital in these various places if you +had lians on all of these positions an + + align:start position:0% +had lians on all of these positions an + + + align:start position:0% +had lians on all of these positions an +octahedral arrangement around the metal + + align:start position:0% +octahedral arrangement around the metal + + + align:start position:0% +octahedral arrangement around the metal +and you can think of these lians as + + align:start position:0% +and you can think of these lians as + + + align:start position:0% +and you can think of these lians as +these negative point + + align:start position:0% + + + + align:start position:0% + +charges and so this is just another uh + + align:start position:0% +charges and so this is just another uh + + + align:start position:0% +charges and so this is just another uh +depiction uh here are the de orbitals + + align:start position:0% +depiction uh here are the de orbitals + + + align:start position:0% +depiction uh here are the de orbitals +again it's a slightly different uh XYZ + + align:start position:0% +again it's a slightly different uh XYZ + + + align:start position:0% +again it's a slightly different uh XYZ +frame but not too much different and so + + align:start position:0% +frame but not too much different and so + + + align:start position:0% +frame but not too much different and so +here are our orbitals and these little + + align:start position:0% +here are our orbitals and these little + + + align:start position:0% +here are our orbitals and these little +uh Green Dots represent the point + + align:start position:0% +uh Green Dots represent the point + + + align:start position:0% +uh Green Dots represent the point +charges so what we'll be thinking about + + align:start position:0% +charges so what we'll be thinking about + + + align:start position:0% +charges so what we'll be thinking about +uh today is the effect of ligans being + + align:start position:0% +uh today is the effect of ligans being + + + align:start position:0% +uh today is the effect of ligans being +close to the de orbitals so you see here + + align:start position:0% +close to the de orbitals so you see here + + + align:start position:0% +close to the de orbitals so you see here +there's a ligan that's quite close up + + align:start position:0% +there's a ligan that's quite close up + + + align:start position:0% +there's a ligan that's quite close up +here and one down here in this picture + + align:start position:0% +here and one down here in this picture + + + align:start position:0% +here and one down here in this picture +these negative Point charged liens are + + align:start position:0% +these negative Point charged liens are + + + align:start position:0% +these negative Point charged liens are +also really close to the orbitals here + + align:start position:0% +also really close to the orbitals here + + + align:start position:0% +also really close to the orbitals here +they're not really as close they're sort + + align:start position:0% +they're not really as close they're sort + + + align:start position:0% +they're not really as close they're sort +of off axis + + align:start position:0% +of off axis + + + align:start position:0% +of off axis +and that becomes really + + align:start position:0% +and that becomes really + + + align:start position:0% +and that becomes really +important all right so let's now think + + align:start position:0% +important all right so let's now think + + + align:start position:0% +important all right so let's now think +about the different D orbitals and the + + align:start position:0% +about the different D orbitals and the + + + align:start position:0% +about the different D orbitals and the +lians when the lians are arranged in an + + align:start position:0% +lians when the lians are arranged in an + + + align:start position:0% +lians when the lians are arranged in an +octahedral + + align:start position:0% + + + + align:start position:0% + +geometry so in this case we have lians + + align:start position:0% +geometry so in this case we have lians + + + align:start position:0% +geometry so in this case we have lians +we have these ligans these negative + + align:start position:0% +we have these ligans these negative + + + align:start position:0% +we have these ligans these negative +point charges coming in on all the + + align:start position:0% +point charges coming in on all the + + + align:start position:0% +point charges coming in on all the +different axes and so if we think about + + align:start position:0% +different axes and so if we think about + + + align:start position:0% +different axes and so if we think about +it these are close and I mentioned that + + align:start position:0% +it these are close and I mentioned that + + + align:start position:0% +it these are close and I mentioned that +in in the last slide so a negative Point + + align:start position:0% +in in the last slide so a negative Point + + + align:start position:0% +in in the last slide so a negative Point +charge along Z is going to be very close + + align:start position:0% +charge along Z is going to be very close + + + align:start position:0% +charge along Z is going to be very close +to dz^2 and it will be repulsive uh for + + align:start position:0% +to dz^2 and it will be repulsive uh for + + + align:start position:0% +to dz^2 and it will be repulsive uh for +dx^ 2us y^2 the negative point charges + + align:start position:0% +dx^ 2us y^2 the negative point charges + + + align:start position:0% +dx^ 2us y^2 the negative point charges +along Y and along X are also going to be + + align:start position:0% +along Y and along X are also going to be + + + align:start position:0% +along Y and along X are also going to be +very close to these D orbitals and that + + align:start position:0% +very close to these D orbitals and that + + + align:start position:0% +very close to these D orbitals and that +will again be repulsive so we're going + + align:start position:0% +will again be repulsive so we're going + + + align:start position:0% +will again be repulsive so we're going +to have a large of repulsive interaction + + align:start position:0% +to have a large of repulsive interaction + + + align:start position:0% +to have a large of repulsive interaction +for these two orbitals with an + + align:start position:0% +for these two orbitals with an + + + align:start position:0% +for these two orbitals with an +octahedral uh + + align:start position:0% + + + + align:start position:0% + +geometry so these two D orbitals are + + align:start position:0% +geometry so these two D orbitals are + + + align:start position:0% +geometry so these two D orbitals are +destabilized and they're destabilized by + + align:start position:0% +destabilized and they're destabilized by + + + align:start position:0% +destabilized and they're destabilized by +the same amount so when they're + + align:start position:0% +the same amount so when they're + + + align:start position:0% +the same amount so when they're +destabilized by the same amount what is + + align:start position:0% +destabilized by the same amount what is + + + align:start position:0% +destabilized by the same amount what is +that + + align:start position:0% +that + + + align:start position:0% +that +called the energy of the orbitals are + + align:start position:0% +called the energy of the orbitals are + + + align:start position:0% +called the energy of the orbitals are +the same what's that + + align:start position:0% +the same what's that + + + align:start position:0% +the same what's that +called yeah so they are + + align:start position:0% + + + + align:start position:0% + +degenerate and so these two orbitals + + align:start position:0% +degenerate and so these two orbitals + + + align:start position:0% +degenerate and so these two orbitals +then will be more destabilized by those + + align:start position:0% +then will be more destabilized by those + + + align:start position:0% +then will be more destabilized by those +Lian negative point charges than the + + align:start position:0% +Lian negative point charges than the + + + align:start position:0% +Lian negative point charges than the +other sets of orbitals because they're + + align:start position:0% +other sets of orbitals because they're + + + align:start position:0% +other sets of orbitals because they're +off axis and the ligans are on axis so + + align:start position:0% +off axis and the ligans are on axis so + + + align:start position:0% +off axis and the ligans are on axis so +the negative point charges will be + + align:start position:0% +the negative point charges will be + + + align:start position:0% +the negative point charges will be +farther away from these guys and let's + + align:start position:0% +farther away from these guys and let's + + + align:start position:0% +farther away from these guys and let's +take uh a look at that as well so here + + align:start position:0% +take uh a look at that as well so here + + + align:start position:0% +take uh a look at that as well so here +we have uh our our three different our + + align:start position:0% +we have uh our our three different our + + + align:start position:0% +we have uh our our three different our +three other D orbitals and if lians are + + align:start position:0% +three other D orbitals and if lians are + + + align:start position:0% +three other D orbitals and if lians are +coming in as negative point charges on + + align:start position:0% +coming in as negative point charges on + + + align:start position:0% +coming in as negative point charges on +axis you're not going to be directly + + align:start position:0% +axis you're not going to be directly + + + align:start position:0% +axis you're not going to be directly +pointing at any of these orbitals + + align:start position:0% +pointing at any of these orbitals + + + align:start position:0% +pointing at any of these orbitals +because they're 45° off axis lians are + + align:start position:0% +because they're 45° off axis lians are + + + align:start position:0% +because they're 45° off axis lians are +on axis so it's not directly pointing + + align:start position:0% +on axis so it's not directly pointing + + + align:start position:0% +on axis so it's not directly pointing +toward any of + + align:start position:0% +toward any of + + + align:start position:0% +toward any of +them so these three orbitals then are + + align:start position:0% +them so these three orbitals then are + + + align:start position:0% +them so these three orbitals then are +stabilized relative to the other sets of + + align:start position:0% +stabilized relative to the other sets of + + + align:start position:0% +stabilized relative to the other sets of +orbitals we talked about and they're + + align:start position:0% +orbitals we talked about and they're + + + align:start position:0% +orbitals we talked about and they're +stabilized by the same amount so those + + align:start position:0% +stabilized by the same amount so those + + + align:start position:0% +stabilized by the same amount so those +three are also + + align:start position:0% + + + + align:start position:0% + +degenerate all all right so to summarize + + align:start position:0% +degenerate all all right so to summarize + + + align:start position:0% +degenerate all all right so to summarize +then um you'll have a large repulsion + + align:start position:0% +then um you'll have a large repulsion + + + align:start position:0% +then um you'll have a large repulsion +for DX 2 minus y^2 and dz^2 + + align:start position:0% +for DX 2 minus y^2 and dz^2 + + + align:start position:0% +for DX 2 minus y^2 and dz^2 +and it they will be more destabilized + + align:start position:0% +and it they will be more destabilized + + + align:start position:0% +and it they will be more destabilized +compared to the other orbitals there'll + + align:start position:0% +compared to the other orbitals there'll + + + align:start position:0% +compared to the other orbitals there'll +be a smaller repulsion for these three + + align:start position:0% +be a smaller repulsion for these three + + + align:start position:0% +be a smaller repulsion for these three +and they will be stabilized compared to + + align:start position:0% +and they will be stabilized compared to + + + align:start position:0% +and they will be stabilized compared to +these sets of + + align:start position:0% +these sets of + + + align:start position:0% +these sets of +orbitals and so here you're really + + align:start position:0% +orbitals and so here you're really + + + align:start position:0% +orbitals and so here you're really +thinking about comparing the D orbitals + + align:start position:0% +thinking about comparing the D orbitals + + + align:start position:0% +thinking about comparing the D orbitals +to a a case where the ligans are sort of + + align:start position:0% +to a a case where the ligans are sort of + + + align:start position:0% +to a a case where the ligans are sort of +all around we'll talk about that in a + + align:start position:0% +all around we'll talk about that in a + + + align:start position:0% +all around we'll talk about that in a +minute so if you localize your lians on + + align:start position:0% +minute so if you localize your lians on + + + align:start position:0% +minute so if you localize your lians on +axis how is this + + align:start position:0% +axis how is this + + + align:start position:0% +axis how is this +affected and this just reminds you and + + align:start position:0% +affected and this just reminds you and + + + align:start position:0% +affected and this just reminds you and +shows you the pictures again um so over + + align:start position:0% +shows you the pictures again um so over + + + align:start position:0% +shows you the pictures again um so over +here they're pointing much more directly + + align:start position:0% +here they're pointing much more directly + + + align:start position:0% +here they're pointing much more directly +toward and here they're away so if it + + align:start position:0% +toward and here they're away so if it + + + align:start position:0% +toward and here they're away so if it +helps you depending on how you like to + + align:start position:0% +helps you depending on how you like to + + + align:start position:0% +helps you depending on how you like to +think about it this is the same uh I had + + align:start position:0% +think about it this is the same uh I had + + + align:start position:0% +think about it this is the same uh I had +these orbitals uh in your hand out on + + align:start position:0% +these orbitals uh in your hand out on + + + align:start position:0% +these orbitals uh in your hand out on +the first page but just to show them + + align:start position:0% +the first page but just to show them + + + align:start position:0% +the first page but just to show them +again uh that you can think about how + + align:start position:0% +again uh that you can think about how + + + align:start position:0% +again uh that you can think about how +close they are see that lian's very + + align:start position:0% +close they are see that lian's very + + + align:start position:0% +close they are see that lian's very +close uh not nearly as close here so + + align:start position:0% +close uh not nearly as close here so + + + align:start position:0% +close uh not nearly as close here so +it's all about the geometry around the + + align:start position:0% +it's all about the geometry around the + + + align:start position:0% +it's all about the geometry around the +metal the geometry of the D orbitals the + + align:start position:0% +metal the geometry of the D orbitals the + + + align:start position:0% +metal the geometry of the D orbitals the +geometry of the + + align:start position:0% +geometry of the + + + align:start position:0% +geometry of the +lians okay so now I'm going to try + + align:start position:0% +lians okay so now I'm going to try + + + align:start position:0% +lians okay so now I'm going to try +rating on the + + align:start position:0% + + + + align:start position:0% + +board so here we're going to think about + + align:start position:0% +board so here we're going to think about + + + align:start position:0% +board so here we're going to think about +how you would draw a diag + + align:start position:0% +how you would draw a diag + + + align:start position:0% +how you would draw a diag +to represent the energy levels when you + + align:start position:0% +to represent the energy levels when you + + + align:start position:0% +to represent the energy levels when you +consider Crystal field + + align:start position:0% +consider Crystal field + + + align:start position:0% +consider Crystal field +Theory so you would have + + align:start position:0% + + + + align:start position:0% + +a what's called Crystal field splitting + + align:start position:0% + + + + align:start position:0% + +diagram so here energy would be going up + + align:start position:0% +diagram so here energy would be going up + + + align:start position:0% +diagram so here energy would be going up +and we have our case we + + align:start position:0% +and we have our case we + + + align:start position:0% +and we have our case we +have a hypothetical case where we have + + align:start position:0% +have a hypothetical case where we have + + + align:start position:0% +have a hypothetical case where we have +five D + + align:start position:0% +five D + + + align:start position:0% +five D +orbitals and so this is the average + + align:start position:0% +orbitals and so this is the average + + + align:start position:0% +orbitals and so this is the average +energy of the D + + align:start position:0% + + + + align:start position:0% + +orbitals average energy of D + + align:start position:0% +orbitals average energy of D + + + align:start position:0% +orbitals average energy of D +orbitals with um with the lians + + align:start position:0% +orbitals with um with the lians + + + align:start position:0% +orbitals with um with the lians +Bound in what's known as a spherical + + align:start position:0% +Bound in what's known as a spherical + + + align:start position:0% +Bound in what's known as a spherical +Crystal + + align:start position:0% + + + + align:start position:0% + +field so this does not exist it's + + align:start position:0% + + + + align:start position:0% + +hypothetical so if the lians were + + align:start position:0% +hypothetical so if the lians were + + + align:start position:0% +hypothetical so if the lians were +everywhere in a sphere around your metal + + align:start position:0% +everywhere in a sphere around your metal + + + align:start position:0% +everywhere in a sphere around your metal +so this is our hypothetical spherical + + align:start position:0% +so this is our hypothetical spherical + + + align:start position:0% +so this is our hypothetical spherical +Crystal field and you imagine the metal + + align:start position:0% +Crystal field and you imagine the metal + + + align:start position:0% +Crystal field and you imagine the metal +is the inside and on the outside you + + align:start position:0% +is the inside and on the outside you + + + align:start position:0% +is the inside and on the outside you +have all the lians so lians are + + align:start position:0% +have all the lians so lians are + + + align:start position:0% +have all the lians so lians are +everywhere they're equally distributed + + align:start position:0% +everywhere they're equally distributed + + + align:start position:0% +everywhere they're equally distributed +everywhere and if they're equally + + align:start position:0% +everywhere and if they're equally + + + align:start position:0% +everywhere and if they're equally +distributed everywhere all the D + + align:start position:0% +distributed everywhere all the D + + + align:start position:0% +distributed everywhere all the D +orbitals would have the same energy so + + align:start position:0% +orbitals would have the same energy so + + + align:start position:0% +orbitals would have the same energy so +it's pointing toward everything equally + + align:start position:0% +it's pointing toward everything equally + + + align:start position:0% +it's pointing toward everything equally +so it's spherical it's completely + + align:start position:0% +so it's spherical it's completely + + + align:start position:0% +so it's spherical it's completely +surrounding the metal so this is a + + align:start position:0% +surrounding the metal so this is a + + + align:start position:0% +surrounding the metal so this is a +hypothetical case because that does not + + align:start position:0% +hypothetical case because that does not + + + align:start position:0% +hypothetical case because that does not +happen ligans are bound in discrete + + align:start position:0% +happen ligans are bound in discrete + + + align:start position:0% +happen ligans are bound in discrete +positions but if it did these would be + + align:start position:0% +positions but if it did these would be + + + align:start position:0% +positions but if it did these would be +of the same energy let me try to get + + align:start position:0% +of the same energy let me try to get + + + align:start position:0% +of the same energy let me try to get +this a little more flat + + align:start position:0% + + + + align:start position:0% + +all right so they're all the same energy + + align:start position:0% +all right so they're all the same energy + + + align:start position:0% +all right so they're all the same energy +well what happens then when you bring + + align:start position:0% +well what happens then when you bring + + + align:start position:0% +well what happens then when you bring +your lians in to their discrete + + align:start position:0% +your lians in to their discrete + + + align:start position:0% +your lians in to their discrete +positions so when you bring your ligans + + align:start position:0% +positions so when you bring your ligans + + + align:start position:0% +positions so when you bring your ligans +in in this case into octahedral geometry + + align:start position:0% +in in this case into octahedral geometry + + + align:start position:0% +in in this case into octahedral geometry +then things + + align:start position:0% +then things + + + align:start position:0% +then things +change + + align:start position:0% +change + + + align:start position:0% +change +then you have a destabilization + + align:start position:0% + + + + align:start position:0% + +you have a + + align:start position:0% +you have a + + + align:start position:0% +you have a +destabilization of your dx2 minus y^2 + + align:start position:0% +destabilization of your dx2 minus y^2 + + + align:start position:0% +destabilization of your dx2 minus y^2 +and dz^2 orbitals so they're going to go + + align:start position:0% +and dz^2 orbitals so they're going to go + + + align:start position:0% +and dz^2 orbitals so they're going to go +up in energy and you'll have a + + align:start position:0% +up in energy and you'll have a + + + align:start position:0% +up in energy and you'll have a +stabilization of your + + align:start position:0% +stabilization of your + + + align:start position:0% +stabilization of your +dxy + + align:start position:0% +dxy + + + align:start position:0% +dxy +dyz and dxz orbitals they are going to + + align:start position:0% +dyz and dxz orbitals they are going to + + + align:start position:0% +dyz and dxz orbitals they are going to +go down in energy so in this + + align:start position:0% +go down in energy so in this + + + align:start position:0% +go down in energy so in this +hypothetical case the D orbitals have + + align:start position:0% +hypothetical case the D orbitals have + + + align:start position:0% +hypothetical case the D orbitals have +equal energy lians are everywhere + + align:start position:0% +equal energy lians are everywhere + + + align:start position:0% +equal energy lians are everywhere +they're pointing at all the D orbitals + + align:start position:0% +they're pointing at all the D orbitals + + + align:start position:0% +they're pointing at all the D orbitals +equally but in an octahedral + + align:start position:0% +equally but in an octahedral + + + align:start position:0% +equally but in an octahedral +case then two orbitals are destabilized + + align:start position:0% +case then two orbitals are destabilized + + + align:start position:0% +case then two orbitals are destabilized +go up in energy because those ligans now + + align:start position:0% +go up in energy because those ligans now + + + align:start position:0% +go up in energy because those ligans now +are pointing right at those orbitals + + align:start position:0% +are pointing right at those orbitals + + + align:start position:0% +are pointing right at those orbitals +they're not pointing equally everywhere + + align:start position:0% +they're not pointing equally everywhere + + + align:start position:0% +they're not pointing equally everywhere +so they're pointing at these orbitals so + + align:start position:0% +so they're pointing at these orbitals so + + + align:start position:0% +so they're pointing at these orbitals so +they go up in energy these orbitals are + + align:start position:0% +they go up in energy these orbitals are + + + align:start position:0% +they go up in energy these orbitals are +in between the axes so they're not + + align:start position:0% +in between the axes so they're not + + + align:start position:0% +in between the axes so they're not +affected as much and they get + + align:start position:0% +affected as much and they get + + + align:start position:0% +affected as much and they get +stabilized these orbitals have a name EG + + align:start position:0% +stabilized these orbitals have a name EG + + + align:start position:0% +stabilized these orbitals have a name EG +and and these orbitals have a name t2g + + align:start position:0% +and and these orbitals have a name t2g + + + align:start position:0% +and and these orbitals have a name t2g +for the octahedral + + align:start position:0% + + + + align:start position:0% + +case and the difference in energy + + align:start position:0% +case and the difference in energy + + + align:start position:0% +case and the difference in energy +between these sets of + + align:start position:0% +between these sets of + + + align:start position:0% +between these sets of +orbitals + + align:start position:0% +orbitals + + + align:start position:0% +orbitals +is is this um sign here sort of this + + align:start position:0% +is is this um sign here sort of this + + + align:start position:0% +is is this um sign here sort of this +Delta uh zero sign and actually o and + + align:start position:0% +Delta uh zero sign and actually o and + + + align:start position:0% +Delta uh zero sign and actually o and +that's for octahedral the O is for + + align:start position:0% +that's for octahedral the O is for + + + align:start position:0% +that's for octahedral the O is for +octahedral and it's the + + align:start position:0% +octahedral and it's the + + + align:start position:0% +octahedral and it's the +Crystal + + align:start position:0% +Crystal + + + align:start position:0% +Crystal +field + + align:start position:0% +field + + + align:start position:0% +field +splitting + + align:start position:0% + + + + align:start position:0% + +energy so it's how much the lians split + + align:start position:0% +energy so it's how much the lians split + + + align:start position:0% +energy so it's how much the lians split +the field so this theoretical case up + + align:start position:0% +the field so this theoretical case up + + + align:start position:0% +the field so this theoretical case up +here there's no splitting going on you + + align:start position:0% +here there's no splitting going on you + + + align:start position:0% +here there's no splitting going on you +bring in the lians and they cause a + + align:start position:0% +bring in the lians and they cause a + + + align:start position:0% +bring in the lians and they cause a +splitting they cause some orbitals to go + + align:start position:0% +splitting they cause some orbitals to go + + + align:start position:0% +splitting they cause some orbitals to go +up in energy and some to go down and the + + align:start position:0% +up in energy and some to go down and the + + + align:start position:0% +up in energy and some to go down and the +distance between them the degree of + + align:start position:0% +distance between them the degree of + + + align:start position:0% +distance between them the degree of +splitting is this octahedral Crystal + + align:start position:0% +splitting is this octahedral Crystal + + + align:start position:0% +splitting is this octahedral Crystal +field splitting + + align:start position:0% +field splitting + + + align:start position:0% +field splitting +energy now the overall energy of the + + align:start position:0% +energy now the overall energy of the + + + align:start position:0% +energy now the overall energy of the +system is + + align:start position:0% +system is + + + align:start position:0% +system is +maintained so if these go up and these + + align:start position:0% +maintained so if these go up and these + + + align:start position:0% +maintained so if these go up and these +go down to get everything to be + + align:start position:0% +go down to get everything to be + + + align:start position:0% +go down to get everything to be +equal let's see draw that right + + align:start position:0% + + + + align:start position:0% + +so these parts some these should go up + + align:start position:0% +so these parts some these should go up + + + align:start position:0% +so these parts some these should go up +trying to draw this straight from this + + align:start position:0% +trying to draw this straight from this + + + align:start position:0% +trying to draw this straight from this +line uh these were going to go up in + + align:start position:0% +line uh these were going to go up in + + + align:start position:0% +line uh these were going to go up in +energy by plus 2 fths the octahedral + + align:start position:0% +energy by plus 2 fths the octahedral + + + align:start position:0% +energy by plus 2 fths the octahedral +crystal field splitting energy and these + + align:start position:0% +crystal field splitting energy and these + + + align:start position:0% +crystal field splitting energy and these +three orbitals are going to go down in + + align:start position:0% +three orbitals are going to go down in + + + align:start position:0% +three orbitals are going to go down in +energy will be stabilized by minus 2 + + align:start position:0% +energy will be stabilized by minus 2 + + + align:start position:0% +energy will be stabilized by minus 2 +fths the octahedral crystal field + + align:start position:0% +fths the octahedral crystal field + + + align:start position:0% +fths the octahedral crystal field +splitting energy so two orbital are + + align:start position:0% +splitting energy so two orbital are + + + align:start position:0% +splitting energy so two orbital are +going up so it's by three fists three + + align:start position:0% +going up so it's by three fists three + + + align:start position:0% +going up so it's by three fists three +orbitals are going down so it's by two + + align:start position:0% +orbitals are going down so it's by two + + + align:start position:0% +orbitals are going down so it's by two +fists because it's going to have to + + align:start position:0% +fists because it's going to have to + + + align:start position:0% +fists because it's going to have to +equal out so you're not sort of creating + + align:start position:0% +equal out so you're not sort of creating + + + align:start position:0% +equal out so you're not sort of creating +a a different system here the energy is + + align:start position:0% +a a different system here the energy is + + + align:start position:0% +a a different system here the energy is +is going to be conserved the overall + + align:start position:0% +is going to be conserved the overall + + + align:start position:0% +is going to be conserved the overall +energy is maintained so two orbitals up + + align:start position:0% +energy is maintained so two orbitals up + + + align:start position:0% +energy is maintained so two orbitals up +2/3 three orbitals down uh two + + align:start position:0% + + + + align:start position:0% + +fths + + align:start position:0% +fths + + + align:start position:0% +fths +okay so that's really it's a very simple + + align:start position:0% +okay so that's really it's a very simple + + + align:start position:0% +okay so that's really it's a very simple +idea + + align:start position:0% +idea + + + align:start position:0% +idea +instead of the + + align:start position:0% +instead of the + + + align:start position:0% +instead of the +theoretical where all the lians are + + align:start position:0% +theoretical where all the lians are + + + align:start position:0% +theoretical where all the lians are +everywhere when you put them in + + align:start position:0% +everywhere when you put them in + + + align:start position:0% +everywhere when you put them in +octahedral Geometry it affects some of + + align:start position:0% +octahedral Geometry it affects some of + + + align:start position:0% +octahedral Geometry it affects some of +the D orbitals differently than others + + align:start position:0% +the D orbitals differently than others + + + align:start position:0% +the D orbitals differently than others +some orbitals go up in energy some go + + align:start position:0% +some orbitals go up in energy some go + + + align:start position:0% +some orbitals go up in energy some go +down the overall energy is + + align:start position:0% +down the overall energy is + + + align:start position:0% +down the overall energy is +maintained so let's look at an example + + align:start position:0% +maintained so let's look at an example + + + align:start position:0% +maintained so let's look at an example +now and figure out how to put electrons + + align:start position:0% +now and figure out how to put electrons + + + align:start position:0% +now and figure out how to put electrons +into this system so let's look at a case + + align:start position:0% +into this system so let's look at a case + + + align:start position:0% +into this system so let's look at a case +where we have + + align:start position:0% +where we have + + + align:start position:0% +where we have +chromium NH h33 + + align:start position:0% +chromium NH h33 + + + align:start position:0% +chromium NH h33 +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +and BR + + align:start position:0% +and BR + + + align:start position:0% +and BR +are three so first we need to figure out + + align:start position:0% +are three so first we need to figure out + + + align:start position:0% +are three so first we need to figure out +the oxidation number of + + align:start position:0% +the oxidation number of + + + align:start position:0% +the oxidation number of +chromium having everything in the + + align:start position:0% +chromium having everything in the + + + align:start position:0% +chromium having everything in the +bracket here means that you have six + + align:start position:0% +bracket here means that you have six + + + align:start position:0% +bracket here means that you have six +lians total three NH3 lians three BR + + align:start position:0% +lians total three NH3 lians three BR + + + align:start position:0% +lians total three NH3 lians three BR +lians or bromide lians and those are all + + align:start position:0% +lians or bromide lians and those are all + + + align:start position:0% +lians or bromide lians and those are all +in one bracket there's no number in the + + align:start position:0% +in one bracket there's no number in the + + + align:start position:0% +in one bracket there's no number in the +corner of the bracket so that means the + + align:start position:0% +corner of the bracket so that means the + + + align:start position:0% +corner of the bracket so that means the +overall charge in this system has to be + + align:start position:0% +overall charge in this system has to be + + + align:start position:0% +overall charge in this system has to be +equal to zero so what will the oxidation + + align:start position:0% +equal to zero so what will the oxidation + + + align:start position:0% +equal to zero so what will the oxidation +number of + + align:start position:0% +number of + + + align:start position:0% +number of +bromine it should be + + align:start position:0% +bromine it should be + + + align:start position:0% +bromine it should be +minus1 3 - 1's what about NH3 as a unit + + align:start position:0% +minus1 3 - 1's what about NH3 as a unit + + + align:start position:0% +minus1 3 - 1's what about NH3 as a unit +zero so 3 * 0 and what does that leave + + align:start position:0% +zero so 3 * 0 and what does that leave + + + align:start position:0% +zero so 3 * 0 and what does that leave +you with for the oxidation number of + + align:start position:0% +you with for the oxidation number of + + + align:start position:0% +you with for the oxidation number of +chromium plus + + align:start position:0% + + + + align:start position:0% + +three so we have plus three so now we + + align:start position:0% +three so we have plus three so now we + + + align:start position:0% +three so we have plus three so now we +can figure out the Del electron count + + align:start position:0% + + + + align:start position:0% + +so we need to look up the group + + align:start position:0% + + + + align:start position:0% + +number + + align:start position:0% + + + + align:start position:0% + +and the group number is + + align:start position:0% + + + + align:start position:0% + +what can you see it up + + align:start position:0% + + + + align:start position:0% + +there most people seem to be saying + + align:start position:0% +there most people seem to be saying + + + align:start position:0% +there most people seem to be saying +six okay so that's right so six - 3 is 3 + + align:start position:0% +six okay so that's right so six - 3 is 3 + + + align:start position:0% +six okay so that's right so six - 3 is 3 +so this is a D3 + + align:start position:0% +so this is a D3 + + + align:start position:0% +so this is a D3 +system so that means we're going to put + + align:start position:0% +system so that means we're going to put + + + align:start position:0% +system so that means we're going to put +in three + + align:start position:0% + + + + align:start position:0% + +electrons so where would you guess I'm + + align:start position:0% +electrons so where would you guess I'm + + + align:start position:0% +electrons so where would you guess I'm +going to put those electrons down here + + align:start position:0% +going to put those electrons down here + + + align:start position:0% +going to put those electrons down here +or up here down am I what if I do + + align:start position:0% +or up here down am I what if I do + + + align:start position:0% +or up here down am I what if I do +this would that be good + + align:start position:0% +this would that be good + + + align:start position:0% +this would that be good +no so we we're coming back to some of + + align:start position:0% +no so we we're coming back to some of + + + align:start position:0% +no so we we're coming back to some of +the roles that you learned learned + + align:start position:0% +the roles that you learned learned + + + align:start position:0% +the roles that you learned learned +earlier in the semester so first you + + align:start position:0% +earlier in the semester so first you + + + align:start position:0% +earlier in the semester so first you +want to put them in the lowest energy + + align:start position:0% +want to put them in the lowest energy + + + align:start position:0% +want to put them in the lowest energy +orbital you don't want to ever have one + + align:start position:0% +orbital you don't want to ever have one + + + align:start position:0% +orbital you don't want to ever have one +with two parallel spins because that + + align:start position:0% +with two parallel spins because that + + + align:start position:0% +with two parallel spins because that +would give you the same four quantum + + align:start position:0% +would give you the same four quantum + + + align:start position:0% +would give you the same four quantum +numbers so that's not good and you also + + align:start position:0% +numbers so that's not good and you also + + + align:start position:0% +numbers so that's not good and you also +if a choice want to put them in if + + align:start position:0% +if a choice want to put them in if + + + align:start position:0% +if a choice want to put them in if +they're the same um energy put them in + + align:start position:0% +they're the same um energy put them in + + + align:start position:0% +they're the same um energy put them in +singly before you start to pair so those + + align:start position:0% +singly before you start to pair so those + + + align:start position:0% +singly before you start to pair so those +are all things that you talked about + + align:start position:0% +are all things that you talked about + + + align:start position:0% +are all things that you talked about +earlier in the system earlier in the + + align:start position:0% +earlier in the system earlier in the + + + align:start position:0% +earlier in the system earlier in the +semester so we put our three electrons + + align:start position:0% +semester so we put our three electrons + + + align:start position:0% +semester so we put our three electrons +in one to each orbital all the spins + + align:start position:0% +in one to each orbital all the spins + + + align:start position:0% +in one to each orbital all the spins +parallel so we have o offb principle + + align:start position:0% +parallel so we have o offb principle + + + align:start position:0% +parallel so we have o offb principle +poly exclusion and also Hun's rule all + + align:start position:0% +poly exclusion and also Hun's rule all + + + align:start position:0% +poly exclusion and also Hun's rule all +at play here with how we put in the + + align:start position:0% +at play here with how we put in the + + + align:start position:0% +at play here with how we put in the +electrons so now we can uh we + + align:start position:0% +electrons so now we can uh we + + + align:start position:0% +electrons so now we can uh we +can talk about the DN electron + + align:start position:0% + + + + align:start position:0% + +configuration and maybe I can write over + + align:start position:0% +configuration and maybe I can write over + + + align:start position:0% +configuration and maybe I can write over +here so that's just a way way of + + align:start position:0% +here so that's just a way way of + + + align:start position:0% +here so that's just a way way of +expressing how many electrons are down + + align:start position:0% +expressing how many electrons are down + + + align:start position:0% +expressing how many electrons are down +here so + + align:start position:0% + + + + align:start position:0% + +DN electron configuration so that would + + align:start position:0% +DN electron configuration so that would + + + align:start position:0% +DN electron configuration so that would +just be equal to + + align:start position:0% +just be equal to + + + align:start position:0% +just be equal to +t2g to the three so you list the name of + + align:start position:0% +t2g to the three so you list the name of + + + align:start position:0% +t2g to the three so you list the name of +these sets of orbitals and that's really + + align:start position:0% +these sets of orbitals and that's really + + + align:start position:0% +these sets of orbitals and that's really +why these have labels because it makes + + align:start position:0% +why these have labels because it makes + + + align:start position:0% +why these have labels because it makes +your life easier instead of listing all + + align:start position:0% +your life easier instead of listing all + + + align:start position:0% +your life easier instead of listing all +the orbitals each time so there are + + align:start position:0% +the orbitals each time so there are + + + align:start position:0% +the orbitals each time so there are +three in this lower energy + + align:start position:0% +three in this lower energy + + + align:start position:0% +three in this lower energy +level now we can also talk about um + + align:start position:0% +level now we can also talk about um + + + align:start position:0% +level now we can also talk about um +Crystal field stabilization + + align:start position:0% + + + + align:start position:0% + +energy Crystal field + + align:start position:0% +energy Crystal field + + + align:start position:0% +energy Crystal field +stabilization energy so don't get this + + align:start position:0% +stabilization energy so don't get this + + + align:start position:0% +stabilization energy so don't get this +confused with Crystal field splitting + + align:start position:0% +confused with Crystal field splitting + + + align:start position:0% +confused with Crystal field splitting +energy this is Crystal field + + align:start position:0% +energy this is Crystal field + + + align:start position:0% +energy this is Crystal field +stabilization energy and it's + + align:start position:0% +stabilization energy and it's + + + align:start position:0% +stabilization energy and it's +abbreviated CF + + align:start position:0% + + + + align:start position:0% + +and that's really just thinking about + + align:start position:0% +and that's really just thinking about + + + align:start position:0% +and that's really just thinking about +how much you stabilize by this splitting + + align:start position:0% +how much you stabilize by this splitting + + + align:start position:0% +how much you stabilize by this splitting +so if you had this uh hypothetical + + align:start position:0% +so if you had this uh hypothetical + + + align:start position:0% +so if you had this uh hypothetical +spherical Crystal + + align:start position:0% +spherical Crystal + + + align:start position:0% +spherical Crystal +field your electrons would be in + + align:start position:0% +field your electrons would be in + + + align:start position:0% +field your electrons would be in +orbitals with this energy but they're + + align:start position:0% +orbitals with this energy but they're + + + align:start position:0% +orbitals with this energy but they're +not after the lians come in in the + + align:start position:0% +not after the lians come in in the + + + align:start position:0% +not after the lians come in in the +octahedral geometry the electrons are in + + align:start position:0% +octahedral geometry the electrons are in + + + align:start position:0% +octahedral geometry the electrons are in +the t2g orbitals so there's they're + + align:start position:0% +the t2g orbitals so there's they're + + + align:start position:0% +the t2g orbitals so there's they're +stabilized this is lower in energy than + + align:start position:0% +stabilized this is lower in energy than + + + align:start position:0% +stabilized this is lower in energy than +where they would have been before and so + + align:start position:0% +where they would have been before and so + + + align:start position:0% +where they would have been before and so +the crystal field stabilization energy + + align:start position:0% +the crystal field stabilization energy + + + align:start position:0% +the crystal field stabilization energy +is a way of indicating whether you've + + align:start position:0% +is a way of indicating whether you've + + + align:start position:0% +is a way of indicating whether you've +overall stabilized the system or not uh + + align:start position:0% +overall stabilized the system or not uh + + + align:start position:0% +overall stabilized the system or not uh +by this by this + + align:start position:0% +by this by this + + + align:start position:0% +by this by this +splitting so the way that you would do + + align:start position:0% +splitting so the way that you would do + + + align:start position:0% +splitting so the way that you would do +this is you would just look at where how + + align:start position:0% +this is you would just look at where how + + + align:start position:0% +this is you would just look at where how +you represent it look at where the + + align:start position:0% +you represent it look at where the + + + align:start position:0% +you represent it look at where the +electrons are and how much they're + + align:start position:0% +electrons are and how much they're + + + align:start position:0% +electrons are and how much they're +stabilized again three orbitals down + + align:start position:0% +stabilized again three orbitals down + + + align:start position:0% +stabilized again three orbitals down +minus 2 fths two orbitals up plus 3 + + align:start position:0% +minus 2 fths two orbitals up plus 3 + + + align:start position:0% +minus 2 fths two orbitals up plus 3 +so in this case this would equal there + + align:start position:0% +so in this case this would equal there + + + align:start position:0% +so in this case this would equal there +are three electrons that are stabilized + + align:start position:0% +are three electrons that are stabilized + + + align:start position:0% +are three electrons that are stabilized +by minus 2 two fths of the octahedral + + align:start position:0% +by minus 2 two fths of the octahedral + + + align:start position:0% +by minus 2 two fths of the octahedral +crystal field splitting energy or you + + align:start position:0% +crystal field splitting energy or you + + + align:start position:0% +crystal field splitting energy or you +would have a stabilization of minus 6 + + align:start position:0% +would have a stabilization of minus 6 + + + align:start position:0% +would have a stabilization of minus 6 +fths times the octahedral crystal field + + align:start position:0% +fths times the octahedral crystal field + + + align:start position:0% +fths times the octahedral crystal field +splitting + + align:start position:0% +splitting + + + align:start position:0% +splitting +energy so that would be the answer to + + align:start position:0% +energy so that would be the answer to + + + align:start position:0% +energy so that would be the answer to +that part + + align:start position:0% + + + + align:start position:0% + +okay so let's look at um another + + align:start position:0% + + + + align:start position:0% + +example and I'll write this in between + + align:start position:0% +example and I'll write this in between + + + align:start position:0% +example and I'll write this in between +here so here we have manganese with six + + align:start position:0% +here so here we have manganese with six + + + align:start position:0% +here so here we have manganese with six +water + + align:start position:0% +water + + + align:start position:0% +water +lians in + + align:start position:0% +lians in + + + align:start position:0% +lians in +Brackets and + + align:start position:0% +Brackets and + + + align:start position:0% +Brackets and +cl3 on the + + align:start position:0% + + + + align:start position:0% + +outside so what is the + + align:start position:0% +outside so what is the + + + align:start position:0% +outside so what is the +overall what's the charge of just this + + align:start position:0% +overall what's the charge of just this + + + align:start position:0% +overall what's the charge of just this +this coordination complex so what's + + align:start position:0% +this coordination complex so what's + + + align:start position:0% +this coordination complex so what's +inside has uh six six lians to this + + align:start position:0% +inside has uh six six lians to this + + + align:start position:0% +inside has uh six six lians to this +inside the brackets so what's the charge + + align:start position:0% +inside the brackets so what's the charge + + + align:start position:0% +inside the brackets so what's the charge +of just that coordination complex + + align:start position:0% +of just that coordination complex + + + align:start position:0% +of just that coordination complex +overall it would be plus + + align:start position:0% +overall it would be plus + + + align:start position:0% +overall it would be plus +three and you know that because these + + align:start position:0% +three and you know that because these + + + align:start position:0% +three and you know that because these +are three negatively + + align:start position:0% +are three negatively + + + align:start position:0% +are three negatively +charged ions counter ions so when the + + align:start position:0% +charged ions counter ions so when the + + + align:start position:0% +charged ions counter ions so when the +whole thing is neutral with three CLS it + + align:start position:0% +whole thing is neutral with three CLS it + + + align:start position:0% +whole thing is neutral with three CLS it +means that had to have been plus three + + align:start position:0% +means that had to have been plus three + + + align:start position:0% +means that had to have been plus three +so what is the charge of + + align:start position:0% +so what is the charge of + + + align:start position:0% +so what is the charge of +water zero so what has to be the charge + + align:start position:0% +water zero so what has to be the charge + + + align:start position:0% +water zero so what has to be the charge +on the + + align:start position:0% +on the + + + align:start position:0% +on the +metal plus + + align:start position:0% +metal plus + + + align:start position:0% +metal plus +three so now we can figure out the Del + + align:start position:0% +three so now we can figure out the Del + + + align:start position:0% +three so now we can figure out the Del +electron + + align:start position:0% +electron + + + align:start position:0% +electron +count what group are we + + align:start position:0% +count what group are we + + + align:start position:0% +count what group are we +in 7 - 3 is 4 so we're a D4 + + align:start position:0% + + + + align:start position:0% + +system all right so now we're we have + + align:start position:0% +system all right so now we're we have + + + align:start position:0% +system all right so now we're we have +four electrons to put in and we're going + + align:start position:0% +four electrons to put in and we're going + + + align:start position:0% +four electrons to put in and we're going +to have a choice we're going to have a + + align:start position:0% +to have a choice we're going to have a + + + align:start position:0% +to have a choice we're going to have a +choice as to whether we put the fourth + + align:start position:0% +choice as to whether we put the fourth + + + align:start position:0% +choice as to whether we put the fourth +Lian up here I mean the fourth electron + + align:start position:0% +Lian up here I mean the fourth electron + + + align:start position:0% +Lian up here I mean the fourth electron +up here or keep the fourth electron down + + align:start position:0% +up here or keep the fourth electron down + + + align:start position:0% +up here or keep the fourth electron down +here and pair and so both of those are + + align:start position:0% +here and pair and so both of those are + + + align:start position:0% +here and pair and so both of those are +possibilities and it depends on the + + align:start position:0% +possibilities and it depends on the + + + align:start position:0% +possibilities and it depends on the +strength of the crystal field so let's + + align:start position:0% +strength of the crystal field so let's + + + align:start position:0% +strength of the crystal field so let's +let's look at uh those + + align:start position:0% + + + + align:start position:0% + +diagrams so there are two possibilities + + align:start position:0% + + + + align:start position:0% + +and and we have again dx^ 2us y^2 dz^2 + + align:start position:0% +and and we have again dx^ 2us y^2 dz^2 + + + align:start position:0% +and and we have again dx^ 2us y^2 dz^2 +up here we have our t2g system our EG so + + align:start position:0% +up here we have our t2g system our EG so + + + align:start position:0% +up here we have our t2g system our EG so +that's that's one drawing or we might + + align:start position:0% +that's that's one drawing or we might + + + align:start position:0% +that's that's one drawing or we might +have a + + align:start position:0% + + + + align:start position:0% + +case where we have something more like + + align:start position:0% +case where we have something more like + + + align:start position:0% +case where we have something more like +this + + align:start position:0% +this + + + align:start position:0% +this +where there's a much + + align:start position:0% + + + + align:start position:0% + +larger a much larger separation between + + align:start position:0% +larger a much larger separation between + + + align:start position:0% +larger a much larger separation between +the sets of orbitals between the EG and + + align:start position:0% +the sets of orbitals between the EG and + + + align:start position:0% +the sets of orbitals between the EG and +the + + align:start position:0% + + + + align:start position:0% + +t2g and so here's our Crystal field it's + + align:start position:0% +t2g and so here's our Crystal field it's + + + align:start position:0% +t2g and so here's our Crystal field it's +small + + align:start position:0% +small + + + align:start position:0% +small +here and here's another Crystal field + + align:start position:0% +here and here's another Crystal field + + + align:start position:0% +here and here's another Crystal field +splitting energy and this one is large + + align:start position:0% + + + + align:start position:0% + +so you have a choice we have to put in + + align:start position:0% +so you have a choice we have to put in + + + align:start position:0% +so you have a choice we have to put in +four electrons and depending on whether + + align:start position:0% +four electrons and depending on whether + + + align:start position:0% +four electrons and depending on whether +it's a small splitting or a large + + align:start position:0% +it's a small splitting or a large + + + align:start position:0% +it's a small splitting or a large +splitting you're going to put them in + + align:start position:0% +splitting you're going to put them in + + + align:start position:0% +splitting you're going to put them in +differently so in this + + align:start position:0% +differently so in this + + + align:start position:0% +differently so in this +case we have a crystal field splitting + + align:start position:0% +case we have a crystal field splitting + + + align:start position:0% +case we have a crystal field splitting +energy that's less than what we call the + + align:start position:0% +energy that's less than what we call the + + + align:start position:0% +energy that's less than what we call the +pairing + + align:start position:0% +pairing + + + align:start position:0% +pairing +energy so the pairing energy is how much + + align:start position:0% +energy so the pairing energy is how much + + + align:start position:0% +energy so the pairing energy is how much +energy it takes to pair up the electrons + + align:start position:0% +energy it takes to pair up the electrons + + + align:start position:0% +energy it takes to pair up the electrons +they prefer to have their own orbital + + align:start position:0% +they prefer to have their own orbital + + + align:start position:0% +they prefer to have their own orbital +they would prefer not to be paired it + + align:start position:0% +they would prefer not to be paired it + + + align:start position:0% +they would prefer not to be paired it +takes a certain amount of energy to pair + + align:start position:0% +takes a certain amount of energy to pair + + + align:start position:0% +takes a certain amount of energy to pair +them so in this case + + align:start position:0% +them so in this case + + + align:start position:0% +them so in this case +because the the splitting is + + align:start position:0% +because the the splitting is + + + align:start position:0% +because the the splitting is +small this set of orbitals up here are + + align:start position:0% +small this set of orbitals up here are + + + align:start position:0% +small this set of orbitals up here are +really not that much higher in energy + + align:start position:0% +really not that much higher in energy + + + align:start position:0% +really not that much higher in energy +than these were so it's not that hard to + + align:start position:0% +than these were so it's not that hard to + + + align:start position:0% +than these were so it's not that hard to +put one up here and it takes more energy + + align:start position:0% +put one up here and it takes more energy + + + align:start position:0% +put one up here and it takes more energy +in this case to pair them up than it + + align:start position:0% +in this case to pair them up than it + + + align:start position:0% +in this case to pair them up than it +does to put one in the higher level so + + align:start position:0% +does to put one in the higher level so + + + align:start position:0% +does to put one in the higher level so +this one would have a drawing like this + + align:start position:0% +this one would have a drawing like this + + + align:start position:0% +this one would have a drawing like this +you have four electrons you put in one + + align:start position:0% +you have four electrons you put in one + + + align:start position:0% +you have four electrons you put in one +of them goes over + + align:start position:0% +of them goes over + + + align:start position:0% +of them goes over +there in this + + align:start position:0% +there in this + + + align:start position:0% +there in this +case we have a really big difference it + + align:start position:0% +case we have a really big difference it + + + align:start position:0% +case we have a really big difference it +would take a lot of energy to put an + + align:start position:0% +would take a lot of energy to put an + + + align:start position:0% +would take a lot of energy to put an +electron way up here so in this + + align:start position:0% +electron way up here so in this + + + align:start position:0% +electron way up here so in this +case the splitting energy is greater + + align:start position:0% +case the splitting energy is greater + + + align:start position:0% +case the splitting energy is greater +than the pairing energy this is really a + + align:start position:0% +than the pairing energy this is really a + + + align:start position:0% +than the pairing energy this is really a +lot higher up here it's small makes not + + align:start position:0% +lot higher up here it's small makes not + + + align:start position:0% +lot higher up here it's small makes not +much difference here the energy is large + + align:start position:0% +much difference here the energy is large + + + align:start position:0% +much difference here the energy is large +so in this case you would want to put + + align:start position:0% +so in this case you would want to put + + + align:start position:0% +so in this case you would want to put +your four electrons all down in the + + align:start position:0% +your four electrons all down in the + + + align:start position:0% +your four electrons all down in the +lower + + align:start position:0% +lower + + + align:start position:0% +lower +level so let's just take a look at some + + align:start position:0% +level so let's just take a look at some + + + align:start position:0% +level so let's just take a look at some +of those rules and say them again so + + align:start position:0% +of those rules and say them again so + + + align:start position:0% +of those rules and say them again so +here when the splitting is small this is + + align:start position:0% +here when the splitting is small this is + + + align:start position:0% +here when the splitting is small this is +called a weak field + + align:start position:0% + + + + align:start position:0% + +so the ligans here they'll be weak field + + align:start position:0% +so the ligans here they'll be weak field + + + align:start position:0% +so the ligans here they'll be weak field +ligans and they'll be strong field + + align:start position:0% +ligans and they'll be strong field + + + align:start position:0% +ligans and they'll be strong field +ligans and we're going to talk about + + align:start position:0% +ligans and we're going to talk about + + + align:start position:0% +ligans and we're going to talk about +that uh next Monday how you will learn + + align:start position:0% +that uh next Monday how you will learn + + + align:start position:0% +that uh next Monday how you will learn +certain lians and whether they're weak + + align:start position:0% +certain lians and whether they're weak + + + align:start position:0% +certain lians and whether they're weak +field or strong field but if they're + + align:start position:0% +field or strong field but if they're + + + align:start position:0% +field or strong field but if they're +weak oh boy they cannot really split + + align:start position:0% +weak oh boy they cannot really split + + + align:start position:0% +weak oh boy they cannot really split +that energy very far they don't have a + + align:start position:0% +that energy very far they don't have a + + + align:start position:0% +that energy very far they don't have a +lot of strength they can't do a huge + + align:start position:0% +lot of strength they can't do a huge + + + align:start position:0% +lot of strength they can't do a huge +splitting they just you know they just + + align:start position:0% +splitting they just you know they just + + + align:start position:0% +splitting they just you know they just +do a little tiny amount of splitting + + align:start position:0% +do a little tiny amount of splitting + + + align:start position:0% +do a little tiny amount of splitting +they're pretty weak lians and in this + + align:start position:0% +they're pretty weak lians and in this + + + align:start position:0% +they're pretty weak lians and in this +case you would have have a + + align:start position:0% +case you would have have a + + + align:start position:0% +case you would have have a +strong a strong + + align:start position:0% +strong a strong + + + align:start position:0% +strong a strong +field where you'd have a large splitting + + align:start position:0% +field where you'd have a large splitting + + + align:start position:0% +field where you'd have a large splitting +so those lians come in and boy they take + + align:start position:0% +so those lians come in and boy they take + + + align:start position:0% +so those lians come in and boy they take +those de orbital energy levels and they + + align:start position:0% +those de orbital energy levels and they + + + align:start position:0% +those de orbital energy levels and they +split them really far apart so those are + + align:start position:0% +split them really far apart so those are + + + align:start position:0% +split them really far apart so those are +strong field lians they create a strong + + align:start position:0% +strong field lians they create a strong + + + align:start position:0% +strong field lians they create a strong +field and this is + + align:start position:0% + + + + align:start position:0% + +large all right so if we look at some of + + align:start position:0% +large all right so if we look at some of + + + align:start position:0% +large all right so if we look at some of +these rules then so if our pairing + + align:start position:0% +these rules then so if our pairing + + + align:start position:0% +these rules then so if our pairing +energy is greater than that energy + + align:start position:0% +energy is greater than that energy + + + align:start position:0% +energy is greater than that energy +difference that means you have a weak + + align:start position:0% +difference that means you have a weak + + + align:start position:0% +difference that means you have a weak +field it's not much different so it's a + + align:start position:0% +field it's not much different so it's a + + + align:start position:0% +field it's not much different so it's a +weak field not much not much splittings + + align:start position:0% +weak field not much not much splittings + + + align:start position:0% +weak field not much not much splittings +the splitting is small and then what + + align:start position:0% +the splitting is small and then what + + + align:start position:0% +the splitting is small and then what +you're going to want to do is put all + + align:start position:0% +you're going to want to do is put all + + + align:start position:0% +you're going to want to do is put all +your electrons in singly to the fullest + + align:start position:0% +your electrons in singly to the fullest + + + align:start position:0% +your electrons in singly to the fullest +extent possible so you use both t2g and + + align:start position:0% +extent possible so you use both t2g and + + + align:start position:0% +extent possible so you use both t2g and +EG you put them all singly until you're + + align:start position:0% +EG you put them all singly until you're + + + align:start position:0% +EG you put them all singly until you're +done before you + + align:start position:0% +done before you + + + align:start position:0% +done before you +pair on the other hand if you have a + + align:start position:0% +pair on the other hand if you have a + + + align:start position:0% +pair on the other hand if you have a +strong field that's going to have a + + align:start position:0% +strong field that's going to have a + + + align:start position:0% +strong field that's going to have a +really large splitting big energy + + align:start position:0% +really large splitting big energy + + + align:start position:0% +really large splitting big energy +difference between t2g and EG sets of + + align:start position:0% +difference between t2g and EG sets of + + + align:start position:0% +difference between t2g and EG sets of +orbitals then that splitting energy is + + align:start position:0% +orbitals then that splitting energy is + + + align:start position:0% +orbitals then that splitting energy is +going to be greater than the pairing + + align:start position:0% +going to be greater than the pairing + + + align:start position:0% +going to be greater than the pairing +energy it's more favorable to pair than + + align:start position:0% +energy it's more favorable to pair than + + + align:start position:0% +energy it's more favorable to pair than +to make that big jump up to this higher + + align:start position:0% +to make that big jump up to this higher + + + align:start position:0% +to make that big jump up to this higher +energy level up here so in that case + + align:start position:0% +energy level up here so in that case + + + align:start position:0% +energy level up here so in that case +what you want to do is you want to pair + + align:start position:0% +what you want to do is you want to pair + + + align:start position:0% +what you want to do is you want to pair +them all up in + + align:start position:0% +them all up in + + + align:start position:0% +them all up in +t2g and only after this is completely + + align:start position:0% +t2g and only after this is completely + + + align:start position:0% +t2g and only after this is completely +full and you can't put any more + + align:start position:0% +full and you can't put any more + + + align:start position:0% +full and you can't put any more +electrons in there do you want to put an + + align:start position:0% +electrons in there do you want to put an + + + align:start position:0% +electrons in there do you want to put an +electron way up there in the EG sets of + + align:start position:0% +electron way up there in the EG sets of + + + align:start position:0% +electron way up there in the EG sets of +orbitals so uh what this what this uh + + align:start position:0% +orbitals so uh what this what this uh + + + align:start position:0% +orbitals so uh what this what this uh +means then is in this case you're going + + align:start position:0% +means then is in this case you're going + + + align:start position:0% +means then is in this case you're going +to have the maximum amount of unpaired + + align:start position:0% +to have the maximum amount of unpaired + + + align:start position:0% +to have the maximum amount of unpaired +electrons because you're going to try to + + align:start position:0% +electrons because you're going to try to + + + align:start position:0% +electrons because you're going to try to +keep them unpaired for as long as you + + align:start position:0% +keep them unpaired for as long as you + + + align:start position:0% +keep them unpaired for as long as you +possibly can and so this is referred to + + align:start position:0% +possibly can and so this is referred to + + + align:start position:0% +possibly can and so this is referred to +as a highs spin + + align:start position:0% +as a highs spin + + + align:start position:0% +as a highs spin +system in this case you're going to have + + align:start position:0% +system in this case you're going to have + + + align:start position:0% +system in this case you're going to have +the minimum number of unpaired you're + + align:start position:0% +the minimum number of unpaired you're + + + align:start position:0% +the minimum number of unpaired you're +trying to pair them up down here before + + align:start position:0% +trying to pair them up down here before + + + align:start position:0% +trying to pair them up down here before +you put one up here so this is a low + + align:start position:0% +you put one up here so this is a low + + + align:start position:0% +you put one up here so this is a low +spin system minimum number of unpaired + + align:start position:0% +spin system minimum number of unpaired + + + align:start position:0% +spin system minimum number of unpaired +electrons that are possible so these are + + align:start position:0% +electrons that are possible so these are + + + align:start position:0% +electrons that are possible so these are +our two um two diagrams that you'll see + + align:start position:0% +our two um two diagrams that you'll see + + + align:start position:0% +our two um two diagrams that you'll see +and uh one question on the on the + + align:start position:0% +and uh one question on the on the + + + align:start position:0% +and uh one question on the on the +problem set has you drawing these these + + align:start position:0% +problem set has you drawing these these + + + align:start position:0% +problem set has you drawing these these +diagrams for these different uh + + align:start position:0% +diagrams for these different uh + + + align:start position:0% +diagrams for these different uh +conditions now this particular one that + + align:start position:0% +conditions now this particular one that + + + align:start position:0% +conditions now this particular one that +we're talking about + + align:start position:0% +we're talking about + + + align:start position:0% +we're talking about +this particular complex is high Spin and + + align:start position:0% +this particular complex is high Spin and + + + align:start position:0% +this particular complex is high Spin and +so next week we're going to talk about + + align:start position:0% +so next week we're going to talk about + + + align:start position:0% +so next week we're going to talk about +why that's true and you'll learn about + + align:start position:0% +why that's true and you'll learn about + + + align:start position:0% +why that's true and you'll learn about +some of the ligans and be able to + + align:start position:0% +some of the ligans and be able to + + + align:start position:0% +some of the ligans and be able to +predict whether it's going to be a high + + align:start position:0% +predict whether it's going to be a high + + + align:start position:0% +predict whether it's going to be a high +spin or low spin + + align:start position:0% +spin or low spin + + + align:start position:0% +spin or low spin +system we can um also go through now and + + align:start position:0% +system we can um also go through now and + + + align:start position:0% +system we can um also go through now and +do uh electron uh configurations and + + align:start position:0% +do uh electron uh configurations and + + + align:start position:0% +do uh electron uh configurations and +also the crystal field um splitting + + align:start position:0% +also the crystal field um splitting + + + align:start position:0% +also the crystal field um splitting +energy so in this + + align:start position:0% +energy so in this + + + align:start position:0% +energy so in this +case our our DN + + align:start position:0% +case our our DN + + + align:start position:0% +case our our DN +configuration is going to be equal to + + align:start position:0% +configuration is going to be equal to + + + align:start position:0% +configuration is going to be equal to +there are three + + align:start position:0% +there are three + + + align:start position:0% +there are three +electrons in + + align:start position:0% +electrons in + + + align:start position:0% +electrons in +t2g and there's one electron in + + align:start position:0% +t2g and there's one electron in + + + align:start position:0% +t2g and there's one electron in +EG and over here we have DN equals in + + align:start position:0% +EG and over here we have DN equals in + + + align:start position:0% +EG and over here we have DN equals in +t2g we have four electrons so those are + + align:start position:0% +t2g we have four electrons so those are + + + align:start position:0% +t2g we have four electrons so those are +the differences in electron + + align:start position:0% +the differences in electron + + + align:start position:0% +the differences in electron +configuration and um + + align:start position:0% +configuration and um + + + align:start position:0% +configuration and um +in the crystal field stabilization + + align:start position:0% +in the crystal field stabilization + + + align:start position:0% +in the crystal field stabilization +energy we have we calculate that we have + + align:start position:0% +energy we have we calculate that we have + + + align:start position:0% +energy we have we calculate that we have +three electrons down + + align:start position:0% +three electrons down + + + align:start position:0% +three electrons down +here so we have three electrons in minus + + align:start position:0% +here so we have three electrons in minus + + + align:start position:0% +here so we have three electrons in minus +2 fths times the crystal field splitting + + align:start position:0% +2 fths times the crystal field splitting + + + align:start position:0% +2 fths times the crystal field splitting +energy and we have one + + align:start position:0% +energy and we have one + + + align:start position:0% +energy and we have one +electron up above so that's plus 3 fths + + align:start position:0% +electron up above so that's plus 3 fths + + + align:start position:0% +electron up above so that's plus 3 fths +there and so - 6 Plus + 3 is going to + + align:start position:0% +there and so - 6 Plus + 3 is going to + + + align:start position:0% +there and so - 6 Plus + 3 is going to +give us - 35ths time the octahedral + + align:start position:0% +give us - 35ths time the octahedral + + + align:start position:0% +give us - 35ths time the octahedral +crystal field splitting energy for this + + align:start position:0% +crystal field splitting energy for this + + + align:start position:0% +crystal field splitting energy for this +system here and you do need to put the + + align:start position:0% +system here and you do need to put the + + + align:start position:0% +system here and you do need to put the +symbol for the octahedral crystal field + + align:start position:0% +symbol for the octahedral crystal field + + + align:start position:0% +symbol for the octahedral crystal field +splitting energy in this not just the + + align:start position:0% +splitting energy in this not just the + + + align:start position:0% +splitting energy in this not just the +number so on the other + + align:start position:0% +number so on the other + + + align:start position:0% +number so on the other +side we only have uh electrons down + + align:start position:0% +side we only have uh electrons down + + + align:start position:0% +side we only have uh electrons down +here and so we're going to have + + align:start position:0% +here and so we're going to have + + + align:start position:0% +here and so we're going to have +four that are times - 2 fths and so our + + align:start position:0% +four that are times - 2 fths and so our + + + align:start position:0% +four that are times - 2 fths and so our +answer is going to be - 8 fths times the + + align:start position:0% +answer is going to be - 8 fths times the + + + align:start position:0% +answer is going to be - 8 fths times the +octahedral crystal field splitting + + align:start position:0% +octahedral crystal field splitting + + + align:start position:0% +octahedral crystal field splitting +energy and every once in a while some + + align:start position:0% +energy and every once in a while some + + + align:start position:0% +energy and every once in a while some +people like to indicate that there's + + align:start position:0% +people like to indicate that there's + + + align:start position:0% +people like to indicate that there's +also something paired so sometimes + + align:start position:0% +also something paired so sometimes + + + align:start position:0% +also something paired so sometimes +you'll see this plus PE which indicates + + align:start position:0% +you'll see this plus PE which indicates + + + align:start position:0% +you'll see this plus PE which indicates +one paired electron but that's sometimes + + align:start position:0% +one paired electron but that's sometimes + + + align:start position:0% +one paired electron but that's sometimes +you might be asked for that so um just + + align:start position:0% +you might be asked for that so um just + + + align:start position:0% +you might be asked for that so um just +to be aware I think your book doesn't + + align:start position:0% +to be aware I think your book doesn't + + + align:start position:0% +to be aware I think your book doesn't +use this but you will see that some + + align:start position:0% +use this but you will see that some + + + align:start position:0% +use this but you will see that some +places + + align:start position:0% +places + + + align:start position:0% +places +all right so that's how we would do uh + + align:start position:0% +all right so that's how we would do uh + + + align:start position:0% +all right so that's how we would do uh +those + + align:start position:0% +those + + + align:start position:0% +those +two all right so um let's uh quickly + + align:start position:0% +two all right so um let's uh quickly + + + align:start position:0% +two all right so um let's uh quickly +look at one more + + align:start position:0% +look at one more + + + align:start position:0% +look at one more +example and here it would be excellent + + align:start position:0% +example and here it would be excellent + + + align:start position:0% +example and here it would be excellent +to have another board but uh let's + + align:start position:0% +to have another board but uh let's + + + align:start position:0% +to have another board but uh let's +quickly do a little bit of erasing and + + align:start position:0% +quickly do a little bit of erasing and + + + align:start position:0% +quickly do a little bit of erasing and +leave our framework + + align:start position:0% +leave our framework + + + align:start position:0% +leave our framework +here all right so + + align:start position:0% + + + + align:start position:0% + +do a little bit of erasing here get rid + + align:start position:0% +do a little bit of erasing here get rid + + + align:start position:0% +do a little bit of erasing here get rid +of this over + + align:start position:0% + + + + align:start position:0% + +here and over + + align:start position:0% + + + + align:start position:0% + +here okay so in this case we're looking + + align:start position:0% +here okay so in this case we're looking + + + align:start position:0% +here okay so in this case we're looking +at Cobalt + + + align:start position:0% +at Cobalt + + + + align:start position:0% +at Cobalt + +2 and the first step is find the + + align:start position:0% +2 and the first step is find the + + + align:start position:0% +2 and the first step is find the +oxidation number but conveniently that + + align:start position:0% +oxidation number but conveniently that + + + align:start position:0% +oxidation number but conveniently that +was given to you it's plus two and then + + align:start position:0% +was given to you it's plus two and then + + + align:start position:0% +was given to you it's plus two and then +we need to do the electron + + align:start position:0% +we need to do the electron + + + align:start position:0% +we need to do the electron +count group number for + + align:start position:0% +count group number for + + + align:start position:0% +count group number for +Cobalt is N9 so we have 9 - 2 or seven + + align:start position:0% +Cobalt is N9 so we have 9 - 2 or seven + + + align:start position:0% +Cobalt is N9 so we have 9 - 2 or seven +so we have a D7 + + align:start position:0% +so we have a D7 + + + align:start position:0% +so we have a D7 +system so for this we'll have a + + align:start position:0% +system so for this we'll have a + + + align:start position:0% +system so for this we'll have a +difference depending on whether you have + + align:start position:0% +difference depending on whether you have + + + align:start position:0% +difference depending on whether you have +a weak field or a strong field and how + + align:start position:0% +a weak field or a strong field and how + + + align:start position:0% +a weak field or a strong field and how +you put in your seven different + + align:start position:0% + + + + align:start position:0% + +electrons so again if we look at the two + + align:start position:0% +electrons so again if we look at the two + + + align:start position:0% +electrons so again if we look at the two +different conditions + + align:start position:0% +different conditions + + + align:start position:0% +different conditions +if we first do this with a weak field + + align:start position:0% +if we first do this with a weak field + + + align:start position:0% +if we first do this with a weak field +then we're going to want to put in our + + align:start position:0% +then we're going to want to put in our + + + align:start position:0% +then we're going to want to put in our +electrons to the fullest extent possible + + align:start position:0% +electrons to the fullest extent possible + + + align:start position:0% +electrons to the fullest extent possible +before pairing so we would go in put one + + align:start position:0% +before pairing so we would go in put one + + + align:start position:0% +before pairing so we would go in put one +2 3 four five now we fill we put one in + + align:start position:0% +2 3 four five now we fill we put one in + + + align:start position:0% +2 3 four five now we fill we put one in +all of them so then we're going to come + + align:start position:0% +all of them so then we're going to come + + + align:start position:0% +all of them so then we're going to come +back and do six seven down + + align:start position:0% +back and do six seven down + + + align:start position:0% +back and do six seven down +here and so this will be the maximum + + align:start position:0% +here and so this will be the maximum + + + align:start position:0% +here and so this will be the maximum +number of unpair that you can possibly + + align:start position:0% +number of unpair that you can possibly + + + align:start position:0% +number of unpair that you can possibly +have or a high spin uh system in this + + align:start position:0% +have or a high spin uh system in this + + + align:start position:0% +have or a high spin uh system in this +case with a strong field takes a lot of + + align:start position:0% +case with a strong field takes a lot of + + + align:start position:0% +case with a strong field takes a lot of +energy to put the electrons up there so + + align:start position:0% +energy to put the electrons up there so + + + align:start position:0% +energy to put the electrons up there so +you're going to want to put them all in + + align:start position:0% +you're going to want to put them all in + + + align:start position:0% +you're going to want to put them all in +the bottom until you're done and you + + align:start position:0% +the bottom until you're done and you + + + align:start position:0% +the bottom until you're done and you +can't put anym down here when you have + + align:start position:0% +can't put anym down here when you have + + + align:start position:0% +can't put anym down here when you have +this strong field when you have this big + + align:start position:0% +this strong field when you have this big + + + align:start position:0% +this strong field when you have this big +big large splitting in energy the + + align:start position:0% +big large splitting in energy the + + + align:start position:0% +big large splitting in energy the +splitting in energy is much greater than + + align:start position:0% +splitting in energy is much greater than + + + align:start position:0% +splitting in energy is much greater than +the pairing energy better to pair than + + align:start position:0% +the pairing energy better to pair than + + + align:start position:0% +the pairing energy better to pair than +to put electrons up here so now would do + + align:start position:0% +to put electrons up here so now would do + + + align:start position:0% +to put electrons up here so now would do +one 2 3 four five six and unfortunately + + align:start position:0% +one 2 3 four five six and unfortunately + + + align:start position:0% +one 2 3 four five six and unfortunately +we have seven so one will have to go up + + align:start position:0% +we have seven so one will have to go up + + + align:start position:0% +we have seven so one will have to go up +there but only one so you see that the + + align:start position:0% +there but only one so you see that the + + + align:start position:0% +there but only one so you see that the +diagrams are different for seven with uh + + align:start position:0% +diagrams are different for seven with uh + + + align:start position:0% +diagrams are different for seven with uh +D7 system depending on whether you're a + + align:start position:0% +D7 system depending on whether you're a + + + align:start position:0% +D7 system depending on whether you're a +weak field or a strong field here you + + align:start position:0% +weak field or a strong field here you + + + align:start position:0% +weak field or a strong field here you +would have the minimum number one of + + align:start position:0% +would have the minimum number one of + + + align:start position:0% +would have the minimum number one of +unpaired electrons low spin here you + + align:start position:0% +unpaired electrons low spin here you + + + align:start position:0% +unpaired electrons low spin here you +have the maximum number uh which is + + align:start position:0% +have the maximum number uh which is + + + align:start position:0% +have the maximum number uh which is +which is + + align:start position:0% +which is + + + align:start position:0% +which is +three and we can uh do our DN count here + + align:start position:0% +three and we can uh do our DN count here + + + align:start position:0% +three and we can uh do our DN count here +so now we have five + + align:start position:0% +so now we have five + + + align:start position:0% +so now we have five +electrons in + + align:start position:0% +electrons in + + + align:start position:0% +electrons in +t2g and we have two electrons in + + align:start position:0% +t2g and we have two electrons in + + + align:start position:0% +t2g and we have two electrons in +EG over here in t2g we have six and in + + align:start position:0% +EG over here in t2g we have six and in + + + align:start position:0% +EG over here in t2g we have six and in +EG we have only + + align:start position:0% +EG we have only + + + align:start position:0% +EG we have only +one and for the uh Crystal field uh + + align:start position:0% +one and for the uh Crystal field uh + + + align:start position:0% +one and for the uh Crystal field uh +splitting energy on this side we would + + align:start position:0% +splitting energy on this side we would + + + align:start position:0% +splitting energy on this side we would +have 5 * minus 2 + + align:start position:0% +have 5 * minus 2 + + + align:start position:0% +have 5 * minus 2 +fths plus 2 * 3 + + align:start position:0% +fths plus 2 * 3 + + + align:start position:0% +fths plus 2 * 3 +fths or a total of minus 4 FS + + align:start position:0% +fths or a total of minus 4 FS + + + align:start position:0% +fths or a total of minus 4 FS +times the splitting energy again we + + align:start position:0% +times the splitting energy again we + + + align:start position:0% +times the splitting energy again we +could add 2 PE for the pairing energy if + + align:start position:0% +could add 2 PE for the pairing energy if + + + align:start position:0% +could add 2 PE for the pairing energy if +that was asked for so optional plus 2 + + align:start position:0% +that was asked for so optional plus 2 + + + align:start position:0% +that was asked for so optional plus 2 +PE and on this side we're going to have + + align:start position:0% +PE and on this side we're going to have + + + align:start position:0% +PE and on this side we're going to have +6 * + + align:start position:0% +6 * + + + align:start position:0% +6 * +-25 plus we have + + align:start position:0% +-25 plus we have + + + align:start position:0% +-25 plus we have +1 3 fths or an answer of - 9 FS times + + align:start position:0% +1 3 fths or an answer of - 9 FS times + + + align:start position:0% +1 3 fths or an answer of - 9 FS times +the octahedral crystal field splitting + + align:start position:0% +the octahedral crystal field splitting + + + align:start position:0% +the octahedral crystal field splitting +energy and again optional we could add + + align:start position:0% +energy and again optional we could add + + + align:start position:0% +energy and again optional we could add +three pairing energies for + + align:start position:0% +three pairing energies for + + + align:start position:0% +three pairing energies for +those okay wow we finished on time given + + align:start position:0% +those okay wow we finished on time given + + + align:start position:0% +those okay wow we finished on time given +all the technical uh issues that's great + + align:start position:0% +all the technical uh issues that's great + + + align:start position:0% +all the technical uh issues that's great +you should be able to finish your whole + + align:start position:0% +you should be able to finish your whole + + + align:start position:0% +you should be able to finish your whole +problem set and have uh experience doing + + align:start position:0% +problem set and have uh experience doing + + + align:start position:0% +problem set and have uh experience doing +these kinds of diagrams \ No newline at end of file diff --git a/g14939TMTCE.txt b/g14939TMTCE.txt new file mode 100644 index 0000000000000000000000000000000000000000..a2b673b00257dfeafe0591a2fb5e080afbbccf63 --- /dev/null +++ b/g14939TMTCE.txt @@ -0,0 +1,2393 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high-quality educational +resources for free. + +To make a donation or view +additional material from + +hundreds the MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +PROFESSOR BAWENDI: Last time you +talked about the first law + +of thermodynamics. + +And you talked about isothermal +expansion, the + +Joule expansion. + +You saw a very important result. +which is that for an + +ideal gas, the energy content +is only dependent on the + +temperature, nothing else. + +Not the volume, not the +pressure, it just cares about + +the temperature. + +So, if you have an isothermal +process for an ideal gas, the + +energy doesn't change. q plus +w is equal to zero for any + +isothermal process. + +And you also saw that du then +could be written as Cv dT for + +an ideal gas always. + +This is not generally true. + +If you have a real gas and you +write du is Cv dT, and your + +path is not a constant +volume path, then you + +are making a mistake. + +But for an ideal gas, you +can always write this. + +And this turns out to be very +useful to remember. + +OK, now most processes that we +deal with are not constant + +volume processes. + +So energy, which has this +wonderful property here, du is + +Cv dt for constant volume +process, which happens to be + +equal to d q, constant volume, +because there's no change. + +there's no work if you've got +a constant volume process. + +So du here is a very interesting +quantity, because + +it's related to the heat that's +going in or out of the + +system under constant +volume process. + +But as I said, we're not +operating usually in a + +constant volume environment. + +When I flail my arms around +I generate work and heat. + +This is not a constant +volume process. + +If I'm the system, what's +constant when I do this? + +Anybody have an idea? + +What's the one function +of state? + +I'm the system, the rest +are the surrounding. + +What's the one function of state +that's constant when I'm + +doing all my chemical +reactions to + +move my arms around? + +Temperature? + +STUDENT: Pressure? + +PROFESSOR BAWENDI: +Pressure, right. + +Pressure is constant. + +What is the pressure at? + +One atmosphere, one bar. + +So the most interesting +processes are the processes + +where pressure is constant. + +When I had have a vial on bench +top, and I do a chemical + +reaction in the vial, and it's +open to the atmosphere, the + +pressure is constant +at one atmosphere. + +When you've got your cells +growing in your petri dish, + +the pressure is constant at +one atmosphere, even if + +they're evolving gas, pressure +is constant. + +So we'd really like to be able +to find some sort of equation + +of state, or some sort of +rather function of state + +that's going to relate the heat +going in or out of the + +system with that function of +state, because this isn't + +going to do it. du only relates +to the heat under + +constant volume. + +And the heat is a really +important thing to know. + +How much heat do you need to put +into a system, or how much + +heat is going to come out of +a system when something is + +happening in the system? + +All right, this is a really +important quantity to know. + +Your boiling water or whatever, +you want to know how + +much heat do you need to boil +that amount of water under + +constant pressure? + +And this is where enthalpy +comes in. + +You've all heard of enthalpy. + +H we're going to write it as +the function of temperature + +and pressure. + +And the reason enthalpy was +invented was exactly for that + +reason, because we need some +way to figure out how to + +relate the heat coming in or +out of a system under a + +constant pressure process. + +Because it's so important. + +And I should add and also under +reversible work, where + +the external pressure is equal +to the internal pressure. + +OK, so we're going to define +enthalpy as u + pV, these are + +all functions of state here, So +H is a function of state, + +and we're going to see now how +this is, indeed, related to + +the heat flow in and +out of the system. + +If you have a constant +pressure, + +reversible work process. + +Let's take a system. + +Under constant pressure T1, V1, +going to a second -- this + +is the system, so let me +write the system here. + +And it's more dramatic if the +system is a gas, p, T2, V2, + +And let's look at what happens +to these functions of state, + +to H to u under this +transformation. + +OK, so let's look at delta u. + +Delta u is q plus w. + +That's the first law. + +And this is a constant pressure +path, so now I can + +write, this q is actually q +under constant pressure. + +Little p means the path is +a constant pressure path. + +And I'm doing reversible work. + +So that w is minus p, dV where +p is the pressure inside the + +system, minus p delta V. +Rearrange that, delta u is + +plus p delta V is +equal to q p. + +All right, so this is the heat +flowing in or out of the + +system, and these are all +functions of state. + +This depends on the path. + +It tells you right here, the +path is constant pressure. + +These don't depend on +the path, right. + +V doesn't care how you +get there. u doesn't + +care how you get there. + +In this case, p is a constant +because the path is constant. + +So we can bring the p +inside, delta u plus + +delta p V it's q p. + +Take this delta outside again, +delta of u plus p V + +is equal to q p. + +And there you have it. + +There is the H right there. + +The u plus p V. Delta +H is equal to q V. + +And this is the reason why +enthalpy was invented, and why + +it's so important. + +Because we want to know this. + +So this for a finite change. + +If you want to have an +infinitestimally small change, + +you end up writing +dh is dq sub p. + +It's not always equal +to the heat. + +It's only equal to the heat if +your process is constant + +pressure reversible work. + +OK, so this is the kind of, this +is the kind of concept + +that needs to be branded into +your brain, so that if I come + +into your bedroom in the middle +of the night and I + +whisper to you delta H, you +know, you should wake up and + +say q p, right? + +Heat under constant pressure +reversible work. + +This should become +second nature. + +This is where the intuition +comes from. + +This is why people +right tables and + +tables of delta H's. + +Why you have delta H's from all +these reactions, because + +this is basically the heat, and +the heat is something we + +can measure, we can control. + +We can figure out how +much heat is going + +in and out of something. + +This is what we're +interested in. + +OK, so last time you +looked at -- any + +questions on this first? + +Yes. + +STUDENT: [INAUDIBLE] from the T +delta V to the delta p here? + +What was the reasoning +behind that? + +PROFESSOR BAWENDI: p +is constant here. + +It's constant pressure. + +OK, so now, last time you looked +at the Joule expansion + +to teach you how to relate +derivatives like du/dV. + +du/dV under constant +temperature. du/dT under + +constant volume. + +You use the Joule expansion +to find these quantities. + +Now these quantities were +useful because you could + +relate them. + +The slope of changes, with +respect to volume or + +temperature of the energy with +respect to quantities that you + +understood, that you +could measure. + +We're going to do the +same thing here. + +So if we take as our natural +variables for enthalpy to be + +temperature and pressure, and we +have some sort of change in + +enthalpy, dH, and it's going +to be related to changes in + +temperature and pressure through +the derivatives dH + +through the slope of the +enthalpy in the T direction, + +keeping pressure constant, dT +plus the slope of enthalpy in + +the pressure direction, keeping +the temperature + +constant, dp, and these are +knobs that we can turn. + +We can change of temperature. + +We can change the pressure. + +These are physical knobs that +are available to us as + +experimentalists. + +And so when we turn these knobs +on our system, we want + +to know how the enthalpy is +changing for that system. + +Because eventually they will +tell us maybe things about how + +heat is changing further on. + +OK, but in order to relate +turning these physical knob to + +this quantity here, which we +don't have a very good feel + +for, we've got to have a +feel for the slopes. + +If I keep the pressure +constant. + +I change the temperature, +what does that mean? + +What is dh/dT? + +If I keep the temperature +constant, and just change the + +pressure, dH is going +to change, but how + +is it going to change? + +What does this mean in terms of +something I can physically + +understand? + +That's the program now for +the next few minutes. + +What are these quantities? + +What is dH/dT as a function, +keeping pressure constant, + +what is dH/dp, keeping +temperature constant? + +All right, let's start with the +first one, dH/dT, keeping + +the pressure constant. + +And we're going to look at a +reversible process to help us + +out, but the result is going to +be independent of whether + +or not we have a reversible +process or + +irreversible process. + +Constant pressure, that means +dp is equal to zero. + +So for reversible process, +constant + +pressure, what do we know? + +This is already branded +in your brain, right? + +Reversible process, constant +pressure dH=dq. + +So we can write that down, +dH=dq, constant pressure. + +That's by definition +of enthalpy. + +That's why we created +enthalpy. + +What else do we know? + +Well we can go look up here, +looking at the differential, + +there are no approximations +here. + +This is just an equality. + +I have a constant pressure +process. + +This term here is +equal to zero. + +That means that dH is also +equal to dH/dT, constant + +pressure dT. + +All right, so now I've got +more dH/dT under constant + +pressure. dH is equal to this, +and it's also equal to this. + +All right, these two are +equal to each other. + +Now, I know how to relate the +heat flow to temperature + +change, through the heat +capacity. dq constant pressure + +is that heat capacity, and I +have to tell you the path for + +the heat capacity. + +So it's C sub p, the heat +capacity under a constant + +pressure path, dT, all right? + +So these two are equal +to each other. + +So, these two are equal to +each other as well, which + +tells me that this derivative, +dH/dT constant pressure is Cp. + +So now I have my first of my +two slopes, in terms of + +something that's related to my +system, the heat capacity of + +the system. + +Something I can measure and I +can tabulate, and when I turn + +my dT knob here I know +what's going to + +happen to the enthalpy. + +So this is the first, +this is the one. + +So it's very similar to what we +saw with the volume and the + +energy, where du/dV under +constant temperature was equal + +to Cv in this case here, right. +and you're going to + +find that there's a lot of these +analogies between energy + +and enthalpy. + +You just change volume to +pressure and basically you're + +looking at enthalpy under a +constant -- anything that's + +done at a constant volume path +with energy, there's the same + +thing happening under constant +pressure path for enthalpy. + +So you can guess the answer +usually that way. + +OK, so now we have the other +one, dH/dp constant + +temperature. + +How do we relate this to +something physical? + +Well, it's going to be an +experiment, very much like the + +Joule experiment. + +The Joule experiment +was a constant + +energy experiment, right. + +Here we're going to have to +find a constant enthalpy + +experiment, and that is going +to be the Joule-Thomson + +experiment. + +That's going to extract out +a physical meaning to this + +derivative here. + +OK, the Joule-Thomson +experiment. + +This is going to get us dH/dp +constant temperature. + +What is this experiment? + +You take a throttle valve, which +consists of some sort of + +porous plug between two +cylinders that is insulated. + +There is insulation here. + +Insulation on the bottom. + +It's like a, think about a tube, +a large tube, insulated + +tube, with a bunch of -- a +frit inside here, which + +prevents flow of gas, which +slows down the flow of gas + +from one side to the other. + +It's a blockage in +this tube here. + +Then you put two pistons, one on +that side here, and one on + +this side here, and the external +pressure here, we're + +going to call that p1. + +The external pressure here, +we're going to call that p2, + +and we're going to do it +slowly enough that the + +pressure on this side of the +cylinder is in equilibrium + +with the external pressure, and +the pressure on this side + +of the cylinder is in + +equilibrium with this pressure. + +But not so slowly that these +two are in equilibrium with + +each other. + +So this is restricting +the flow, so there's + +some sweet spot here. + +When I'm pushing slowly enough +here that the pressure here is + +equal to that one, but not so +slowly that the air flow from + +here to here is fast, compared +to how fast I'm pushing. + +You got the picture here? + +Any questions on that? + +All right, then as I push +through, I'm going to start + +with all of my gas on this +side, and at the end, I'm + +going to have all the gas +on the other side. + +Let me first ask you this, is +this a reversible or in + +irreversible process? + +Right, let me add one more piece +of data here which I + +said in words, but which is +actually important to write + +down before doing the problem. + +Is this a reverse +-- any guesses? + +How many people vote for that +this is a reversible process? + +I've got one vote back +there, two votes, + +three votes, four votes. + +Anybody else? + +How many people think this +is irreversible? + +It's about a tie, and everybody +else doesn't now. + +All right, I'm going to give +you ten seconds, fifteen + +seconds to make up your mind. + +You're not allowed to be +on the fence here. + +You've got to decide, +all right? + +This is, you can talk to your +neighbors, you know, do a + +little bit of thinking. + +And I'm going to give you ten +seconds to figure this out, + +what your vote is for that. + +All right, let's try again. + +How many people vote that +this is reversible? + +That looks like a +majority to me. + +Irreversible? + +Let's look at the +show of hands? + +All right, so this is +the majority here. + +Good thing physics doesn't +work on the rule of the + +majority, otherwise we'd +be in big trouble. + +Wow, let's walk through that. + +I'm sorry to say that this +is the wrong answer. + +OK, why is that the +wrong answer? + +Well, just think, you know, +think about it. + +You're pushing through here. +p1 is greater than p2. + +What does it mean for a process +to be in equilibrium + +or reversible? + +It means at any point you can +reverse the direction of time, + +and it will look fine, right. + +So now I'm pushing on this +plug here, with p1 + +greater than p2. + +I'm pushing, I'm pushing, +I'm pushing. p1 is + +greater than p2. + +Then I want to reverse +direction of time. + +I want the arrow of time to go +so that the gas goes from p2 + +to p1. p2 is less than p1. + +Is that going to work out? + +If p2, the pressure in p2, is +less than the pressure in p1, + +is the gas going to want to go +from p2 to p1 and the whole + +thing reverse back? + +You've got to put more pressure +on one side than the + +other if you want to push +that gas through + +the throttle, right? + +So this is where the time scale +issue comes into play. + +I said let's do this slowly +enough that this p1 is in + +equilibrium with this p1, but +not so slowly that this + +pressure is equivalent +to that pressure. + +If I do it really, really +slowly, so that everything is + +reversible, well I won't be able +to do it, because p1 and + +p2 are different. + +But suppose that I fix my +pistons here, with p1 greater + +than p2, and I don't touch +it, eventually p1 + +will be equal to p2. + +I'll come to some sort +of equilibrium. + +So this is a system which +is out of equilibrium. + +If I stop, if I move slowly, +if I move more slowly, then + +these two will want +equilibrium. + +So this is an irreversible +process. + +The Joule-Thomson experiment +is irreversible. + +OK, important -- if you are part +of this group here, think + +about it and make sure +you understand that. + +All right, so this is +the experiment. + +Now what are we doing +with that? + +The initial state, let's look +at what we are doing. + +So initially, we're going to +have our piston, there's the + +plug sitting here. + +Our piston on the right side +here fully out, and the piston + +on my right side, your left +side, fully inside. + +There's no gas on +that side here. + +So there's p2 sitting here. + +There is p1 sitting here, and +all of the gas is sitting on + +that side of the plug. + +Then after we're done with the +experiment, we'll have + +transferred all of the gas from +one side to the other. p1 + +here. p2 sitting here. + +And there's going to be some +volume V2 and some volume V1, + +but are not necessarily +the same. + +Especially since the pressures +are different. we don't know + +yet about temperature so I don't +know what to say about + +these volumes because I don't +know what the temperatures' + +are going to do. + +OK, so let's go through this and +see what we would do which + +is to calculate the +heat and the work. + +This is well insulated. + +So, what is the -- let's +do the first one here. + +What's q for this process here? + +Anybody? + +STUDENT Zero. + +PROFESSOR BAWENDI: +Zero, right. + +This is an adiabatic process. + +It's well insulated. + +Heat is not going in or out, +adiabatic. q is equal to zero. + +So all we need to find +out is the work now. + +Let's divide it up into the two +sides, the work going on + +on the left hand side, my left +hand side or your left hand + +side, and the work going on +on the right hand side. + +So let's first look at +the left hand side. + +OK, so w, first of all, work is +being done to the system on + +the left hand side here. + +I'm pressing on the gas. + +So I expect that to be +a positive number. + +The pressure is constant, p. + +The V goes from V1 to zero. + +So we write down p1, V1. + +On the right hand side, the +work, let's call this left + +hand side, let's call this +right hand side. + +Here there's an expansion going +on, so the system is + +doing work to the +external world. + +This piston is being brought +out, so we expect the work to + +be negative, negative. + +And we start out with +zero volume. + +We end up with a volume of V2, +and the external pressure is + +constant to p2. + +Minus p2, V2. + +Minus p delta V. So the total +work is the work from the left + +hand side plus the work on the +right hand side, which is p1 + +V1 minus p2 V2. + +Which I can rewrite +as minus delta pV. + +Delta pV is p2 V2 minus p1 V1. + +It's the pressure volume +multiplied together at the + +final state, minus pressure +volume from the initial state, + +with the minus sign +here because it's + +the negative of that. + +All right, what is delta u? +delta u is q plus w. q is + +zero. delta u is just w. + +So this is also just delta u. +delta u is minus delta pV, for + +the process. + +OK, delta H is delta +of u plus pV. + +By definition, that's how we +define enthalpy up here. + +H is u plus pV. + +Delta H is delta of u plus pV, +which is equal to delta u, + +plus delta pV. + +Now delta u is minus delta pV. + +So I have minus delta +pV plus delta pV. + +This is equal to zero. + +So this irreversible process, +this Joule-Thomson process, is + +a constant enthalpy process. + +Delta h for this process +is equal to zero. + +Adiabatic q equal to zero. + +It's also delta H +which is zero. + +The two didn't necessarily +follow, because remember, + +delta H is dq so p is only true +for a reversible constant + +pressure process. + +This is an irreversible +process. + +So a priori, this was not +necessarily true. + +It turns out after you do all +the math, it turns out to be + +delta H equals zero. + +All right, so this is +the experiment. + +How do we go from that +experiment to the terms that + +we're trying to get, +these slopes. + +Remember, we're trying to get +delta H, we're trying to get + +dH/dT constant pressure and +dH/dp constant temperature. + +OK, these are the two things +were trying to get here. + +OK, so let's write down, +what we know here. + +I'm missing something. + +Oh, we already know one thing. + +We already know this guy here. + +We already did that. + +OK, dH/dT constant +pressure is Cp. + +That was easy one. + +So we already know that. + +So now we can write or +differential dH as Cp dT plus + +dH/dp, constant temperature, +dp. + +Now we want to find out +what this guy is here. + +Now for this experiment, this +is a constant enthalpy + +experiment for the Joule-Thomson +experiment, this + +is equal to zero. + +So I can rearrange this to get +this dH/dp in terms of things + +that I can either measure, like +the heat capacity, or + +that I have control of, +like dT and dp. + +So in this case, dH/dp constant +temperature is minus + +Cp dT/dp, and this is under +constant temperature, no, not + +constant temperature. + +Whatever the experi -- for +that the experiment is. + +For that experiment, the +constraint, so we need a + +constraint here, right, we +need a constraint here. + +Right? + +We need a constraint here. + +The constraint isn't constant +temperature because the + +temperature is going +to be changing. + +It's not constant pressure, +because we have a + +delta p going on. + +It's not constant +volume either. + +The constraint is the constraint +of the experiment, + +and the constraint of the +experiment is that the + +enthalpy is constant. + +So the constraints +we have here, is + +the constant enthalpy. + +It's the constant enthalpy +process that we're looking at. + +This we can do experiments on. + +It's tabulated in books, and +this we can measure in the + +experiment. + +Delta p here is the change in +pressure from the left side to + +the right side, and we can put +a thermometer, measure the + +temperature before the +experiment, and measure the + +temperature after +the experiment. + +So this is something +we can measure. + +So now we have this derivative, +in terms of + +physical quantities, things +that we can measure. + +Things that we can relate +to the properties of the + +substance that we're doing +the experiment on. + +So this is basically delta +T and delta p and the + +Joule-Thomson experiment. + +And so Joule and Thomson did +these experiments, and they + +measured lots of gases, and they +found that, in fact, this + +was something that they +could measure. + +Sometimes it was positive, +sometimes it was negative, and + +it was an interesting number. + +And so they defined them, after +many experiments, the + +limit of this, delta T delta p +and the limit of delta p goes + +to zero as the Joule-Thomson +coefficient. + +So, basically dT/dp, constant +enthalpy is equal to mu, by + +definition, Joule-Thomson, where +mu Joule-Thomson is the + +Joule-Thomson coefficient, just +like you saw last time + +eta sub j was the Joule +coefficient for dT/dV under + +constant energy. + +So there's, again, total analogy +here between what + +we're doing with enthalpy to +what you did last time with + +energy, replace p with +T and H with u. + +Flip those two and you +get the same thing. + +OK, so now we have dH/dT is +equal to Cp, and we can also + +write, then, dH/dp under +constant temperature is equal + +to minus Cp mu Joule-Thomson. + +We have our two derivatives in +terms of physical quantities, + +which is going to allow us, +then, whenever we have a + +change to go back and, when we +have a change where we adjust + +the temperature and the +pressure, we'll be able to + +know what the enthalpy +change is. + +OK, now let's take two cases. + +Let's first start talking +about ideal gases. + +The last time you saw that for +an ideal gas, the energy only + +cared about the temperature. + +It didn't care what the volume +was doing. du/dV under + +constant temperature was equal +to zero for an ideal gas. + +And by analogy, we expect the +same thing to be true here, + +because enthalpy and energy +have all this + +analogy going on here. + +So let's look at an ideal gas. + +So for an ideal gas, we saw that +u was only a function of + +temperature. + +We also have the equation +of state for an + +ideal gas, pV = nRT. + +We can write our definition of +enthalpy, h is u plus pV. + +This only depends on the +temperature. pV= nRT. + +So we have u only depends +on temperature plus nRT. + +The only valuable now on this +side is temperature. + +Pressure and volume +have dropped out. + +So enthalpy, for an ideal gas, +only cares about temperature. + +Pressure has dropped out of the +picture completely here. + +So there is no p dependence +here. + +H for an ideal gas is only a +function of temperature. + +This is not true for a real +gas, fortunately, but it's + +true for an ideal gas. + +So for an ideal gas then, +dH/dp under constant + +temperature, that has +to be equal to zero. + +Because temperature is constant +H only cares about + +temperature. and that's +equal to zero. + +And if that's equal to zero, +that means that the + +Joule-Thomson coefficient +for an ideal gas is + +also equal to zero. + +We're going to actually prove +this later in the course. + +Right now, you're taking +it for granted. + +Right now we told you Joule did +all these experiments and + +he found out that for an ideal +gas, that the limit in and + +ideal gas case was that the +eta J was equal to zero. + +Therefore, from experiments, +u is only a function of + +temperature for an ideal gas, +and therefore from these + +experiments, we come +out with delta H + +dH/dp is equal to zero. + +The Joule-Thomson coefficient +is equal to zero. + +Later we are going to prove it +exactly. but right now you're + +going to have to take +it for granted. + +So, if the Joule-Thomson +coefficient is equal to zero, + +just like we wrote, du = Cv dT +for an ideal gas, we're going + +to have dH = Cp dT for +an ideal gas as well. + +dH is Cp dT. + +This term goes away. +dH = Cp dT. + +That's the only thing +that's left behind. + +So if you know the heat +capacity, you know the change + +in temperature, you know +what enthalpy is doing + +for an ideal gas. + +This needs to be stressed that +this is the ideal gas case. + +Now regular gases, real gases, +fortunately as I + +said, don't obey this. + +This is important because we +use this all the time for + +when, when we do technology. + +One example of Joule-Thomson +coefficient being not equal to + +zero for a real gas that you've +like experienced is if + +you take a bicycle pump, take +a bicycle pump, and you're + +pumping up your tire, you're +working pretty hard, so you're + +getting hot. + +But if you touch the valve going +into your tire, which + +basically measures the +temperature of the air going + +into your tire, that is +getting hot, right. + +So if you've got to pump that +tire really a lot, then you're + +going to you're going +to really feel + +a lot of heat there. + +The compression of the, +basically it's an adiabatic + +compression. + +You're taking the air inside +of the pump and you're + +compressing it. + +You're doing it so fast that +there's not enough time for + +heat to come out of the gas +that's inside the pump towards + +the walls of the pump. + +So your time scale it just +fast enough that this is + +basically an adiabatic +compassion. + +Your compressing it really fast, +all right, so you're + +changing the pressure. + +You're changing the pressure, +and the temperature is going + +up. dT/dp is positive. dT/dp +is positive. dT/dp is + +positive, well that's mu +JT. dT/dp is mu JT. + +So for a real gas like air, +this is a positive number. + +It's not zero. + +Air is not an ideal gas. + +It's one simple example of -- + +The fact that mu JT is not zero +for real gases is how we + +are able to liquify things like +hydrogen and helium, by + +compressing them and pushing +them through a nozzle, and the + +expansion through the nozzle +cools the gas. + +Right, in this case here it +wouldn't happen if it + +was an ideal gas. + +Or in many kinds of gas +refrigerators where you push a + +gas through a nozzle close to +room temperature, what you + +find is that the gas coming out +on the other side under + +lower pressure is cooler than +the gas that went through on + +the other side. + +Real refrigerators actually work +with liquids that go into + +gases so use the latent heat of +the liquid, so it doesn't + +really work like the +Joule-Thomson expansion. + +So this is real. + +This is real, unlike the Joule +coefficient which is very + +small so that most gases have +tiny Joule coefficients. + +So if you do a Joule experiment, +you hardly measure + +a temperature change. + +With real gases, here you +do actually measure it. + +You can feel it with your finger +on your bicycle tire. + +OK, so we're going to see this +using a Van der Waal's gas. + +Let's look at a Van der Waal's +gas and see what happens in + +the Van der Waal's gas. + +Any questions, first? + +What we've been talking about, +the Joule-Thomson experiment, + +constant enthalpy process? + +OK, so let's take our +Van der Waal's gas. + +Remember the equation of state +for Van der Waal's gas is not + +pV is equal to nRT, but p plus +the attraction term. + +And then V minus the excluded +volume term is equal to RT. + +Two parameters, this is the +attraction between two atoms + +or molecules in the gas phase. + +This is the repulsion, +not the repulsion. + +This is the fact that we occupy +a finite volume in + +space, because they're little +hard spheres in this molecule. + +OK, in a few weeks, you're going +to find out that we can + +calculate dH/dp from this +equation of state, and you're + +going to find out that dH/dp +from that equation of state is + +proportional to b +minus a over RT. + +This is going to be probably +a homework at + +some point to do this. + +For now, let's take +it for granted. + +Let's take it for granted that +we know how to calculate this + +derivative from an equation +of state like this. + +But now we're going +to use that. + +OK. + +So since dH/dp under constant +temperature is proportional to + +minus mu JT, then we have that +dT/dp under constant enthalpy + +than it is related to the +negative of this, a over RT + +minus b + +All right, this is how the +temperature changes when you + +change, when you have +pressure changing. + +So when you do an expansion or +compression, my adiabatic + +compression of my bicycle +pump is dT/dp. + +All right. + +Or when I do an expansion of +hydrogen or helium at low + +temperature, through a +Joule-Thomson experiment, when + +I want to liquify hydrogen +or helium. + +I want to cool a gas with a +Joule-Thomson experiment, what + +temperature do I +have to be at? + +So this tells you that you +have to be careful what + +temperature you're at, because +depending on how high, how big + +this temperature here is, you +could either be, have a + +negative dT/dp, if this first +term is small enough, meaning + +if temperature is very high, +then you end up with a + +negative term. + +If the temperature is very +small, then one over the + +temperature is large, and the +first term wins and you have a + +positive number. + +So there's some special +temperature which is going to + +depend on the gas where the +first term is going to be + +equal to the second term, where +Joule-Thomson is zero, + +or it's going to behave +like an ideal gas. + +So when that is the case, +we're going to call that + +temperature the inversion +temperature or T inv. + +We call that inversion because +on one side you end up cooling + +if you compress. + +And on the other side of that +temperature you end up heating + +if you compress. + +OK, so there's some temperature, +t inversion minus + +b where the gas behaves +like an ideal gas. + +The Joule-Thomson coefficient +is zero and that inversion + +temperature, you can +solve for it. + +Conversion temperature is equal +to a over R times b. + +OK, so when you are at that +temperature, everything looks + +like an ideal gas, +as far as the + +enthalpy changes are concerned. + +Now if you're at the temperature +which is higher + +than the inversion temperature, +in that case + +here, a over RT is small +compared to b, and this is + +going to turn out +to be negative. + +So if you had a high +temperature, this a small + +compared to b. + +If you're negative, which means +that dT/dp at constant H + +is less than zero. + +So that means that if you +compress something + +it's going to cool. + +The temperature rises when the +pressure drops, right? + +Or in this case here, if I do my +Joule experiment delta p is + +negative, p2 is less than p1, +that means that delta T is + +positive, right? + +So in this experiment here, this +side is going to heat up. + +So for materials where T +inversion is low, lower than + +room temperature, then you would +end up heating up in + +this expansion. + +You're basically expanding the +gas from one side to the other + +and the expansion causes the +temperature to rise. + +If T is less than T inversion, +you have the opposite case, + +and dT/dp is greater +than zero. + +So in this experiment here, +delta p is less than zero. + +You need to have this whole +thing greater than zero. + +So delta T is less than +zero as well. + +So if you're below the inversion +temperature and you + +do the Joule-Thomson experiment, +you're going to + +end up with something that's +colder on this + +side than that side. + +Ideal gas would be the +same temperature. + +But now, so this is where the +refrigeration comes in. + +So if you take a gas, and you're +below the inversion + +temperature and you make it go +through this irreversible + +process, the gas comes +out colder from that + +side than that side. + +So the work that you're doing to +expand, to go through this + +experiment, ends up +cooling the gas. + +OK, for most gases, T inversion +is much greater than + +300 degrees Kelvin. + +Much greater than room +temperature. + +For more most gases, if you +do this experiment at room + +temperature, you end up cooling +the gas, and you can + +cool it measurably, which is why +also, your bicycle pump, + +you know, you push down, +you compress, this is + +an expansion here. + +You're expanding from this +side to that side. + +Bicycle pump you are compressing +the gas, which is + +the opposite, you end up heating +up the air in the + +bicycle pump in your +compression. + +There are two exceptions to this +rule that most gases have + +a T inversion which is greater +than 300 degrees Kelvin, and + +that's hydrogen. + +The T inversion for hydrogen +turns out to be 193 degrees + +Kelvin, and the T inversion for +helium turns out to be 53 + +degrees Kelvin. + +And so when, there's a lot of +liquid helium that's being + +used on campus. + +We use a liquid helium. + +And so in order to make a liquid +helium, you can't take + +helium at room temperature and +do this, because if you did, + +you would just heat it up, +because the room temperature + +is above the inversion +temperature, so Joule-Thomson + +would heat up the helium. + +So you need first to take the +liquid helium and cool it + +below 53 degrees Kelvin before +you can do the Joule-Thomson + +to cool it even further +to make liquid helium. + +So you have to do +it in stages. + +You take your room temperature +liquid helium, and you cool it + +with liquid nitrogen to 77 +degrees Kelvin, the new, + +you're not quite there yet, +unfortunately right? + +Then you take hydrogen you cool +it would liquid nitrogen + +to 77, then you can use +your hydrogen gas. + +Do a Joule-Thomson hydrogen gas +which you first cool with + +liquid nitrogen. + +Liquid nitrogen, 77, that's +below 193, so you can do + +Joule-Thomson on hydrogen, cool +the hydrogen to below 53, + +then use your cold hydrogen to +cool the helium, and then you + +can do the Joule-Thomson on the +helium to cool it further + +until it liquifies. + +So that's what you do when +you make liquid helium. + +All right, any questions on +this lecture or any of the + +concepts that we talked about? + +The last thing that we're going +to do today then is to + +look at a relationship which +is going to turn out to be + +very useful. + +It's a relationship for ideal +gases which relates the heat + +capacities at constant pressure +and constant volume. + +Cp = Cv + R. This is very useful +because often you just + +have lots of tables of Cp's but +sometimes you want to know + +what the energy change is going +to be for the ideal gas, + +and you know that du +is Cv dT not Cp dT. + +So, you need to know what Cv +is, and if this is true + +always, then there's a +very easy way to go + +from one to the other. + +We're going to do it two ways. + +Today we'll do the first way, +and then next time we'll do + +the second way. + +The first way is just to turn +the crank on the math, and the + +second way is to do +a little bit more + +imaginative about the process. + +OK, let's just turn the +crank on the maths. + +What do we know about +the Cp and Cv? + +Well Cp, we already know how to +relate it to dH/dT through + +the slope of the enthalpy, and +we also related Cv to the + +slope of the energy with respect +to temperature under + +constant volume. + +And we also know that +H is u plus pV. + +Right, H is u plus pV. + +So we're going to take the +derivatives of both sides of + +this equation here, by, with +respect to temperature, + +keeping pressure constant. + +So we have dH/dT keeping +pressure constant, is du/dT + +keeping pressure constant. + +Got to keep track of what's +being constant, kept constant, + +plus dPV/dT, keeping pressure +constant. dH/dT keeping + +pressure constant, that's just +Cp, and then we have du/dT + +keeping pressure constant. + +The p is constant here, comes +out of the equation, so we + +have p and then we have dV/dT +well it's an ideal gas, an + +ideal gas for dV/dT for an ideal +gas is equal to R over p + +because pV is equal +to RT, right. + +So dV/dT is Rp. + +So dV/dT is times R over +p, the p's are going + +to cancel out here. + +OK, so now it's very tempting +at this state to say, oh + +there's the answer right +here. du/dT is Cv. + +There I have it Cp is equal +to Cv plus R, right? + +But even though it looks like +that's the right way to do it, + +it's actually not right because +it turns out to be + +right by sort of by accident. + +But here you've got pressure +constant. du, this is du, not + +H here. du/dT is only equal +to Cv when the volume is + +constant, not when the +pressure is constant. + +So if you're going to turn the +crank on the math correctly, + +you're going to have to change +this p into a V somehow. + +Because this isn't Cv +mathematically speaking. + +We don't know what it is yet. + +In order to change this from a +p to a V, you have to use the + +chain rule. + +So let's use the chain rule. + +And then we'll be done. + +OK, so u is actually a function +of temperature and + +volume, which in this case here +could be a function of + +pressure and temperature. + +So if we want du/dT under +constant pressure, you have to + +use the chain rule. + +There's the pressure +sitting right here. + +It's going to be du/dT under +constant volume, plus du/dV + +dV/dT under constant pressure. + +All right, chain rule. du/dT +constant pressure is the + +direct derivative with respect +to temperature here, which is + +sitting by itself under constant +volume, keeping this + +constant but there +is temperature + +sitting right here too. + +That's where that term comes +from, du/dV dV/dT. + +Now, for an ideal gas, du/dV +under constant temperature is + +equal to zero. + +It doesn't care what the +volume is doing. + +It only cares what +temperature is. + +If temperature is constant, +there's no change in energy. + +For an ideal gas, +this is zero. + +It's not zero for a real gas. + +Right, so this whole term +disappears and for an ideal + +gas, it turns out that du/dT +constant pressure is equal to + +du/dT constant volume, but +this is equal to Cv + +for an ideal gas. + +It wouldn't be true for a real +gas, and this is a common + +mistake that people make for +real gases to equate this. + +This is only true for +an ideal gas. + +Since it's true for an ideal +gas, then we can go ahead and + +replace this with Cv, and then +we have Cp with Cv plus R, + +which is what we were after. + +OK, next time we'll do the other +way of getting to the + +same answer. \ No newline at end of file diff --git a/htYyCEdc8B4.txt b/htYyCEdc8B4.txt new file mode 100644 index 0000000000000000000000000000000000000000..13510f9a38c14de46a309cb2e64899c6cd6b013f --- /dev/null +++ b/htYyCEdc8B4.txt @@ -0,0 +1,933 @@ +PROFESSOR: Recombinant DNA, +often referred to also as + +genetic engineering. + +This is a series of techniques, +series of methods + +that allow us to manipulate DNA +for a variety of reasons. + +Now, we take it for granted. + +It's very much part of our +everyday life in the + +laboratory. + +It's made a huge impact on +the biotechnology and + +pharmaceutical industries +as well. + +It wasn't always so +uncontroversial. + +In fact, in the 1960s and '70s, +when this technology was + +first being developed, it was +great concern about scientists + +manipulating DNA, manipulating +genetic material. + +In the city of Cambridge, in +fact, had a moratorium for a + +while on the practice of +genetic engineering or + +recombinant DNA technology, +which fortunately, ultimately + +was overcome with good practices +and I think good + +education about what the real +limits of risk and benefit + +were so that now it's used very +widely and, I would also + +say, very safely. + +The bottom line for what we're +going to talk about today and + +for this section of the class is +the ability to isolate and + +to amplify specific +DNA sequences. + +They might be particular genes +of interest to us. + +They might be whole genomes. + +They might be other regions of +DNA, but we need to be able to + +isolate them from the cells of +the organisms of interest, + +amplify them up into large +quantities in order to be able + +to study them in detail, and to +make modifications in them. + +This is done in a variety +of organisms for + +a variety of purposes. + +One of them, and this is by no +means the only one, but one + +that sort of strikes home +is the ability to make + +therapeutic proteins, to be +able to manufacture in the + +laboratory or in a company +proteins they could have + +benefit for patients who are, +for example, lacking the + +function of a particular protein +or enzyme leading to a + +disease state. + +One can use these methods to +produce that protein in the + +laboratory, and treat +the individual. + +This can be done in bacteria +such as E. coli. + +E. coli, which is the common +gut bacterium that we all + +carry, a very useful organism. + +We use it in the lab. + +We're going to use in our +demonstrations today. + +This is the standard vehicle +in which we'd grow up, + +recombinant DNA, amplify +recombinant DNA for further + +uses, but we can also make +therapeutic proteins using the + +manufacturing capabilities +of the bacterium. + +Plants, likewise, +can be a source + +of therapeutic proteins. + +We can modify the genomes of +plants so they will produce in + +large quantities therapeutic +proteins of interest, which + +then can be ingested by the +individual, which can reduce + +production costs significantly, + +and animals, likewise. + +We can manipulate the genes of +animals so that they will + +express a protein of interest +and secrete that protein, for + +example, into the milk. + +So there are so-called +transgenic cows and transgenic + +goats that produce therapeutic +proteins in the mammary gland + +and secrete those therapeutic +proteins into the milk. + +So the individual just needs to +drink the milk and receive + +the relevant dose. + +So there are lots of ways, that +this technology can be + +helpful including in the +context of medicine. + +We can also engineer +organisms. + +I've already given you examples +of that, but that was + +really for the purposes of using +those organisms as a + +factory to make something +of interest to us. + +But we can manipulate the genes +of plants, for example, + +to make them resistant to +various pests to make them + +more robust, to give them +a longer shelf life. + +We can manipulate them for the +better production of things + +that are valuable to us. + +Again, this is a bit of +a controversial area, + +genetically modified foods, not +always well-accepted by + +everyone because again, the +thought is, this might be + +disrupting the food chain in +important ways, and this might + +be ultimately not +so beneficial. + +Personally don't agree with +that, but lots of people do + +feel that way. + +We're going to teach you the +methods that we use to allow + +us to do this. + +And again, in work that I've +alluded to from my own lab, we + +use these methods to manipulate +the genes of + +animals, in our case it's mice, +but there are lots of + +animal species that one can use +in order to create, for + +example, disease models. + +We talked to you about, +Professor Brown talked to you + +about genetic diseases. + +They have specific alterations +in genes. + +We can use these methods to make +similar alterations in + +the genes of mice and other +animal species and then study + +the disease process in those +animals, develop new + +treatments in those animals +in ways that are + +hard to do in people. + +So there's lots and lots, and +these are just a few examples, + +lots and lots of important uses +for genetic engineering + +and recombinant DNA +technology. + +One that we'll emphasize in +just a few lectures and is + +becoming extremely common and +popular nowadays is DNA + +sequencing. + +You need to isolate the DNA from +the organism of interest + +and then have it in such a +fashion that you can sequence + +it's nucleotides. + +This is a very popular +activity now. + +And specifically with respect +to human health, DNA + +sequencing, But some of the +other methods that we're going + +to talk about as well, allow +us to characterize + +disease-causing mutations +at molecular detail. + +So we know what causes x +disease or y disease. + +We can understand the +consequences for the + +individual-encoded proteins +for the pathways that they + +regulate, and we can come up +with better medicines. + +I think about this with respect +to cancer, but it's + +really changing the treatment +of all diseases as we + +understand more the molecular +basis, the genetic basis of + +those diseases. + +And these techniques have +been essential to + +allow us to do that. + +I want to cover a little bit +of history so that you know + +from whence this came. + +Things really began +to pick up in this + +field in the late 1960s. + +And the critical advance at this +stage, was the discovery + +of a method to cleave DNA into +defined fragments, to start + +with a genome or chromosome +and to be able to cut it + +particular places reproducibly +so that one could isolate + +fragments of DNA away from the +mass of DNA, isolate a + +particular region of the DNA +away from everything else + +using this method. + +It wasn't enough just +to cut the DNA up. + +You had to amplify it up. + +In order to amplify it up, you +needed a vessel in which to do + +the amplification, and the +vessel of choice as I + +mentioned was bacteria. + +And this relied on a method that +actually was known for + +decades before but actually was +not used for this purpose + +until the early 1970s, and +it's called bacterial + +transformation. + +You can transform bacteria by +adding a new DNA sequence, and + +the bacteria will take up that +new DNA sequence and begin to + +express the genes that are +present on that DNA sequence + +as if it was one of their own. + +So the transfer of DNA a was +critical, this process of + +bacterial transformation. + +And then the final thing which +also occurred in the 1970s was + +the identification of methods to +amplify DNA sequences once + +they got inside of bacteria. + +It wasn't enough to actually +get them in there. + +You needed some special way +to cause the bacterium to + +amplify, that is, to replicate +the DNA that was present + +within them. + +And these three events, which +all came together in about a + +five to ten year period, really +initiated, launched + +what we now call the recombinant +DNA revolution and + +initiated the biotechnology +industry, which + +started in the mid 1970s. + +And an individual above all +others who is credited with + +launching the biotechnology +industry was Robert Swanson + +who in 1966 or so was +sitting where you + +are as an MIT freshman. + +Bob Swanson was class +of '69, actually. + +And at the age of 28, in 1976, +founded the company Genentech + +with a scientist, Herb Boyer, +who was very instrumental in + +some of those breakthroughs that +I just mentioned to you. + +And I mention Bob to you now +because of your connections + +through MIT. + +But he was a wonderful guy and +sadly passed away from + +glioblastoma at the age of 52. + +So he didn't really get to fully +realize the benefits of + +what he had started, but +he did, in fact, + +start a great deal. + +And this is a famous statue at +Genentech which shows Herb + +Boyer and Bob Swanson talking +about the idea for the first + +time and you might notice over a +beer, very important part of + +science, discussions +over a beer. + +In addition to this connection +to MIT and really in honor of + +Bob's connections to MIT, and +a great pride that Bob had + +actually in MIT, credited MIT +greatly with him learning + +about science, the importance of +science, and also business. + +He got a degree in chemistry as +well as a degree from the + +Sloan School. + +We decided when we launched the +Koch Institute to name a + +very large space in the Koch +Institute for Bob Swanson. + +It's called the Swanson +Biotechnology Center. + +You can visit it. + +So it's a series of core +facilities that support all of + +our researchers. + +And indeed, researchers across +the MIT campus, and this is a + +nice quote from Bob's widow, +Judy Swanson, who has been + +very supportive of +this effort. + +So Bob Swanson and MIT, in many +ways, actually, have a + +lot to do with the technology +and the revolution that we're + +going to talk about now. + +All right. + +So as I mentioned, we are +going to do a demo. + +We're going to teach you a +real-life example now of how + +this work is done. + +And our goal is to +clone a gene. + +You can actually wait +right there, Anna. + +Thanks. + +We're going to clone a gene, +and we're going to clone a + +particular gene. + +It's a toxin gene. + +It's a gene from a pathogenic +bacterium. + +And you might ask the question, +a reasonable + +question, why the heck +would you do that? + +Why would you clone +a toxin gene? + +So what do you think? + +What's the purpose in the +laboratory of cloning out a + +toxin-encoding gene from +a pathogenic bacterium? + +So several people have suggested +the obvious was that + +you want to engage in global +terror, which we actually + +don't support here at MIT, so +we're going to take that down. + +But maybe somebody else +is going to do that. + +So perhaps it would be good if +we got one step ahead of the + +game, isolated the gene, +manufactured the protein, and + +then made a vaccine against that +toxin so that we could + +prevent the bad consequences +of exposure to the toxin. + +Or maybe that thing is actually +very interesting + +independent of its bad uses. + +We could learn stuff, which +might be helpful ultimately in + +related activities. + +So for the general purpose of +biomedical research, we often + +study how these organisms work +because it can teach us + +things, sometimes surprising +things that are + +useful down the road. + +The organism in question is +Streptococcus pyogenes. + +Streptococcus pyogenes, which +causes in certain cases, in + +certain individuals a disease +called necrotizing fasciitis. + +Necrotizing fasciitis, which +is otherwise more commonly + +called the flesh-eating +disease. + +And you might think I'm +joking, but I'm not. + +This is a true thing. + +This is a true thing, and some +of you might be squeamish, and + +if you are, and I'm being +serious here. + +If you're squeamish looking +at ugly, nasty, disgusting + +pictures, close your +eyes for a second. + +I'll tell you when you +can open them. + +But this is an individual who +was exposed to this bacterium + +and developed necrotizing +fasciitis. + +That's a real-world case, so +it is really pretty bad. + +You can open your eyes now +if you closed them. + +I hesitate to show that slide +because in the past, I've had + +a few boys throw up when +I showed that slide. + +So what are we going to do? + +Well, we're going to +isolate this gene. + +And in order to isolate this +gene, we need to be able to + +separate it, this gene, +from the chromosome + +in which it is contained. + +And the chromosome from which +it is contained is the + +chromosome of S. pyogenes. + +So this is the S. pyogenes +chromosome. + +It's about four million +base pairs and it + +has about 1,000 genes. + +So spread throughout this +circular chromosome, there are + +lots of genes. + +We're interested +in one of them. + +Now, this chromosome also has +another thing on it, which I + +hope you all know about from +the material that Professor + +Sive just covered for you. + +What is the one piece of DNA +material that all chromosomes + +need in order to replicate? + +AUDIENCE: Origin +of replication. + +PROFESSOR: An origin of +replication, very good. + +An origin of replication. + +It has an origin of replication, +and then it has a + +bunch of genes. + +It has gene A. I'm just +making this up. + +It has gene B, and it +has a whole bunch of + +other genes as well. + +And then it has -- and imagine +that this orange chalk was red + +because it's more effective +if it's red. + +It has the T gene, and that's +the toxin gene. + +So our goal is to transfer the +T gene and not the rest of + +this stuff, because we don't +actually care about the rest + +of the stuff. + +We just care about +the T gene -- + +into the E. coli cells for +the reasons that I + +mentioned up there. + +And in order to do that, we have +to grow large amounts of + +the organism that's going to +in a sense donate the DNA. + +We then isolate the chromosomal +DNA, and we'll + +show you how. + +We're then going to use this +method to fragment the DNA not + +randomly, but in specific +places. + +And then we're going to transfer +the DNA of interest + +to E. coli using this method +of transformation. + +We're going to take this +fragment and move it through + +the membrane of the E. coli so +that it becomes resident + +inside the E. coli cell. + +So now on to our demonstration +and my lab assistant, Anna + +Deconinck, will help me here. + +So what we've done is to, in +the laboratory, isolate S. + +pyogenes as well as E. coli, +grow them up in large + +quantities. + +You've got your gloves, right? + +So I'll take the buffers. + +So we have various solutions and +buffers that will allow us + +to sort of wash the stuff we +don't want away from the + +bacterial cells, lice the +bacterial membrane, isolate + +the nucleic acid away from all +the other stuff that's inside + +the cells, and then we'll purify +the chromosomal DNA. + +So Anna has grown up E. coli +and S. pyogenes, taken that + +suspension of cells, and used +a centrifuge to spin those + +cells down to the bottom of +these tubes here-- you can + +show them, Anna-- these +tubes here. + +And the first thing we need +to do is get rid of the + +supernate, the broth that +the cells grew in. + +So first, we're going +to decant. + +Here, you can decant the +pyogenes, but be + +careful with it. + +So we're going to decant this +in order to grow up the + +amounts of bacteria +that we need. + +Now we're doing this in a +very small quantities. + +In fact, in industrial scale, +you do it in huge-- + +ANNA: Sorry. + +PROFESSOR: Ah, that's +a problem. + +It's actually a bit +more of a problem. + +ANNA: I just have a +buffer to wash. + +PROFESSOR: I don't think that's +going to do it, Anna. + +Dude, we may need to actually +skip, we may need to cancel. + +This is a little more serious. + +Wait a minute. + +Well, I don't know. + +Maybe. + +Let's just see if it's +safe or not. + +I think it'll be okay. + +All right. + +That was a joke. + +She did very well though, +don't you think? + +She did very well. + +That was outstanding. + +Anybody want some apple juice? + +You're welcome to it. + +ANNA: It needs ice. + +PROFESSOR: Of course we would +never bring pathogenic + +bacterium to class. \ No newline at end of file diff --git a/jgSn1mB8uSI.txt b/jgSn1mB8uSI.txt new file mode 100644 index 0000000000000000000000000000000000000000..005c43a4b1a9e1a98aa6f724ccbdf415080b29c3 --- /dev/null +++ b/jgSn1mB8uSI.txt @@ -0,0 +1,3391 @@ +The following +content is provided + +under a Creative +Commons license. + +Your support will help MIT +OpenCourseWare continue + +to offer high quality +educational resources for free. + +To make a donation or +view additional materials + +from hundreds of MIT courses, +visit MIT OpenCourseWare + +at ocw.mit.edu. + +PROFESSOR: Good afternoon. + +So we are still in a +discussion of atoms + +in external magnetic fields. + +And we are working our way +up from simple static fields + +to time dependent fields. + +Last week and the +week before, we + +covered external magnetic +fields, Zeeman shifts, + +different coupling limits, +strong field, and weak field. + +Last class on Friday, +we talked about what + +happens when you put atoms +into DC electric fields. + +So what we did was simple. + +Lowest order, which means +in this case, second order + +perturbation theory. + +And we derived an +explicit expression + +for the polarizability, alpha. + +And this polarizability +tells us how energy levels + +are shifted quadratically +with the electric field. + +I put some emphasis +in talking about what + +is inside perturbation theory +and identified with you that, + +yes, if you have +an electric field, + +we have electrostatic energy. + +But in order to +polarize the atoms, + +we have to create +an internal energy. + +In a concrete example, +if we have an s state, + +we have to mix a p state +to create a dipole moment. + +And this costs energy. + +Exactly in the same way +as when you have a spring + +and pull on the +spring with gravity, + +you gain gravitational energy. + +But you have two pay +exactly half of it + +to create internal +energy in your spring. + +And this is actually the +reason for this factor of 1/2 + +as we discussed in great length. + +Question is do you have any +questions about that part? + +Because we want to +go to the next level. + +Perturbation theory? + +DC polorizability? + +So anyway, the menu +for today is we + +have done perturbation theory +here for weak electric fields. + +But the question came already +up in class, is it really valid? + +Or for what regime +is it invalid? + +So today I want to +talk to you briefly + +what happens when we go +beyond perturbation theory. + +When we go beyond the +quadratic Stark effect. + +And that leads us +to a discussion + +on stability of atoms in +strong electric field and field + +ionization. + +I like to sort of feature +it because it allows + +me to tell you something +about the peculiar properties + +of Rydberg atoms. + +And also the +ionization of Rydberg + +atoms through electric field. + +This is how people in our +field create cold plasmas. + +And it's also a way to do a very +sensitive detection of atoms. + +So what I'm telling you today +is interesting for its own sake, + +but also because it's an +important tool for manipulating + +atoms, creating plasmas, +or sensitive detection. + +So this will probably only +take 10 or 20 minutes. + +And then we want to go +form DC electric fields + +to AC electric fields. + +So we then discuss +the AC polarizability. + +And, well, that will take +us from perturbation theory + +in a time independent way what +we have done now for DC fields + +to time dependent +perturbation theory. + +So all the topics are +rather basic aspects + +of quantum physics. + +But as usual, I try to give +you some special perspectives + +from the atomic physics side. + +So in perturbation theory, we +have a mixture of other states. + +And this said mixture is +done with the matrix element. + +And in perturbation +theory, we always + +have an energy denominator. + +Intermediate state +to ground state. + +And if the electric field +is smaller than this value, + +then we have mixture of other +states into the ground state. + +So usually when we estimate +the validity of perturbation + +theory, we look +for the state which + +is closest to the ground state. + +For which the energy +denominator is smallest. + +So therefore, i here is the +nearest state, but, and this + +is important, of +opposite parity. + +Otherwise, because of the +parity selection rule, + +the matrix element would +be 0 and electric field + +does nothing. + +I made a comment on Friday, +but let me do it again. + +That, of course, means that +when we apply electric field + +to our favorite +atoms, we don't have + +to worry about the +other hyperfine states. + +The other hyperfine states have +the same spatial wave function. + +Have the same parity. + +So we are really here talking +about the first excited state. + +And a concrete example +for those of you + +who work with alkalis +with an s ground + +state, the relevant +energy scale here + +is the excitation energy +to the first p state. + +So let's just estimate it +for a single electron atom. + +And well, this is a +hydrogenic estimate. + +The excitation energy to +the first excited state. + +1s to 2p is about 1 Rydberg. + +And the Rydberg is +nothing, or Hartree, + +and that's nothing else +than e square over a0. + +It's electric potential +of two charges separated + +by Bohr radius. + +And if we estimate +that the matrix element + +for strong transition is on +the order of the Bohr radius, + +there are no other length +scales in the problem, + +we find that the value for the +electric field in atomic units + +is the charge divided by +the Bohr radius squared. + +And this is really high. + +It is on the order of 5 times +10 to the 9 volt per centimeter. + +And this is 1,000 times +larger than laboratory + +electric fields. + +Those fields would just create +sparking along the electrodes. + +You cannot apply such +high electric fields + +in a laboratory. + +So, therefore, nothing +to worry about. + +If you have ground state +atoms, the Stark effect + +in perturbation theory +is all you need. + +Actually, to be a little +bit more precise when + +I used the Rydberg and a0, I +made a little bit overestimate. + +So that the typically the +critical electric field + +which would cause a breakdown +of perturbation theory + +for the ground +state is around 10 + +to the 9 volt per centimeter. + +OK, so we are safe when we +talk about ground states. + +But once we got to the excited +state, we have degeneracy. + +p states have a +three fold degeneracy + +and they are states +with opposite parity. + +So we can't have mixing there. + +And actually as we will +see for excited states, + +we have already a breakdown +of perturbation theory + +at very, very small +electric field. + +So let us discuss +hydrogenic orbits + +with principal +quantum number, n. + +And if you estimate what is +the size of the matrix element? + +Well, it's not just a0. + +There is a scaling with +n which is n square. + +The matrix element in higher +and higher excited state scales + +with n square. + +Well, how does the +energy separation scale? + +Well, let's not +discuss hydrogen here. + +Because in hydrogen, energy +levels are degenerate. + +And we would immediately +get a breakdown + +of perturbation theory. + +Let's rather formulate +it for general atoms. + +And we had this nice discussion +about the quantum defect. + +So if we compare the energy of +two l states, they scale as 1 + +over n square. + +But for different l states, we +have different quantum defects. + +Delta l plus 1. + +And here we have delta l. + +So, therefore, doing +an expansion in m + +which we assume to be large, we +find that the energy difference + +is proportional to the +difference between the quantum + +defects for the +two states we want + +to mix with the electric field. + +And then again, the scaling with +the principal quantum number + +is n cube. + +So, therefore, we find +for the critical field + +using the criterion +I mentioned above. + +We take the energy splitting. + +The energy the denominator which +appears in perturbation theory. + +We divide by the value +of the matrix element. + +Well, we had the Rydberg +constant or two times + +the Rydberg constant is nothing +else than b squared over a0. + +The matrix element +was 1 over a0. + +And then we have the difference +between quantum defects. + +And now-- and this makes +it really so dramatic. + +We had an n square scaling +of the matrix element. + +And we have an into the minus 3 +scaling of energy differences. + +So that means the critical +field scales by n to the 5. + +Go to an excited state +with n equals 10. + +And the breakdown of +perturbation theory + +happens 100,000 times earlier. + +So some of the scaling +in atomic physics + +is very, very +dramatic when you go + +to more highly excited state. + +If you threw in that quantum +defects become very small, + +once you go beyond +s and p states. + +The higher states just don't +penetrate into the nucleus. + +So if l is larger than 2, if +you have more complicated atoms, + +you may add the angular +momentum of the core here. + +But so if you put n to the 5 +scaling and the small quantum + +defect together, you find +that critical electric fields + +are smaller than one +volt per centimeter + +already for principal +quantum numbers as low as 7. + +So that means bring a 1.5 volt +battery close to your atom + +and you drive it crazy. + +You drive it out of +perturbation theory. + +So what we have +is the following. + +We have, of course, +the structure + +of atoms in excited field. + +Here is the electric field. + +And let me just +pick three n values. + +18, 19, 20. + +And now the +structure, of course, + +is that by the +criterion I actually + +gave you was the criterion for +the application of perturbation + +theory. + +If the energy levels are +smaller than the matrix element, + +you have to rediagonalize +between those levels. + +And that gives you then not a +quadratic, but a linear effect. + +So, therefore, the +structure is here + +that you have a region where +you have strong l mixing. + +So you have to use +degenerate perturbation + +theory for the +different l states. + +But the many folds in n, the +principle quantum number, + +are still well separated. + +But then, eventually, +when you go further, + +you have a region which +is called n mixing. + +So now the electric +field is really + +completely rediagonalizing your +states with different quantum + +numbers, n. + +So the result of +this discussion is + +that highly excited +states of atoms + +behave very differently +from ground state atoms. + +And n to the 5 scaling +is sensitivity to volt + +per centimeter. + +Level mixing all over the place. + +And that's why for those +highly excited states, + +people have coined the word +Rydberg atoms or Rydberg + +matter. + +That means atoms with higher +principal quantum numbers. + +And the study of Rydberg +atoms was pioneered, well, + +the early pioneering work +by our own, Dan Kleppner. + +And then Herbert +Walther in Munich + +who happened to be +my Ph.D. Advisor. + +And finally, Serge +Haroche, who was recognized + +with the last Nobel Prize +together with Dave Wineland. + +So this is not just theory. + +What I am showing to +you here is spectroscopy + +done at MIT by Dan Kleppner. + +So what is done here is +from the ground state, + +they excite to an excited state. + +And whenever you hit an excited +state, you see a signal. + +Let's focus on the upper part. + +So if at a given electric +field, you scan the laser, + +you get one of those traces. + +You find peaks, peaks, peaks. + +And those peaks correspond to +the different and many folds + +with strong Stark mixing. + +And eventually when you go +to somewhat higher field, + +you have states +all over the place. + +And this is the regime where +you have done n mixing. + +So in the '70s and +'80s, there was really, + +those experiments obtained +a clear understanding + +and description +of atoms in, well, + +I would say high +electric fields. + +But the fields were not so high. + +It was just the atoms were +very sensitive that already + +is at lower electric +fields, they + +reached what is regarded +as the high-field limit. + +Now the question is +when we recorded signal, + +suddenly the traces stop. + +And that means the electric +field is now so high + +that the atom no longer +has a stable state. + +The electric field is so +high that it literally rips + +the electron away from the atom. + +And if you go to higher +states, the electric field + +where this happens is lower. + +This is the process +of field ionization + +and that's what we +want to discuss next. + +Question? + +AUDIENCE: Um, for what atoms? + +PROFESSOR: Those studies were +actually done for lithium. + +It's actually peculiar. + +Dan Kleppner really +liked hydrogen. + +Dan Kleppner is the +person who tried + +to do almost all +experiments with hydrogen. + +The famous BEC experiment. + +He also had the +Rydberg experiment + +which was just in building 26 +where Vladan Vuletic teaches + +now, his labs. + +This is where +spectroscopy of hydrogen + +were done with the +goal of a precision + +measurement of the +Rydberg constant. + +So we excited hydrogen to +some of those high levels. + +But as probably +the experts know, + +the hydrogen atom is the +hardest atom to work with. + +Because you need +[INAUDIBLE] and alpha. + +You have this huge gap to +the first excited state. + +And that's why if +you can get away, + +you try to work +with other atoms. + +And in those +experiments, those people + +worked with the lithium atom. + +So the lithium atom +has a quantum defect + +which will actually contrast +to hydrogen where the quantum + +defect is 0. + +And this will actually +be very, very important + +for field ionization as +I want to discuss now. + +Other questions? + +OK, so at a given electric +field, states, so to speak, + +just disappear. + +They're no longer stable. + +And this is the process which +is called field ionization. + +So the phenomenon is +that sufficiently strong + +electric fields ionize the atom. + +And whenever there +is a simple model + +and I can give you an analytic +answer, I try to do that. + +Because I feel a +lot of our intuition + +is shaped by understanding +simple models. + +And the simplest model +for field ionization + +is just the classical +model by calculating + +what is the settle point +in the combined potential. + +The combined potential +of the nucleus + +which is a Coulomb potential +and the external magnetic field. + +So many features +of the experiment + +can be understood by this +simple three line derivation. + +So we have a potential. + +One part of it is the +Coulomb potential. + +And focusing on one +spatial direction here. + +And then, in addition, we +apply an electric field. + +And the electric field +creates a linear potential. + +And if I take the sum of the +two, well, at large distances, + +see, it's the electric +field which dominates. + +Then the Coulomb +potential takes over. + +So that's how it looks like. + +So now we have the situation +if we would put in atoms + +and we would look at +the energy eigenvalues. + +At this point, this is +the maximum excited state + +in the atom which +is still stable. + +So what I want to derive +for you is what determines + +the stability is simply +the settle point. + +When the binding energy of +the excited state for which we + +use the Rydberg +formula is not stronger + +than the position +of the settle point, + +the atom becomes unstable it +and becomes field ionized. + +And we'll discuss +a little bit later + +if this really +applies to real atoms. + +The quick answer is for lithium +and all the other atoms, + +it applies. + +For hydrogen, it doesn't. + +Because hydrogen has +too many symmetries. + +Too many exact degeneracies. + +OK, so the total potential +is the Coulomb potential + +plus the electric potential. + +What we need is the position +of the settle point. + +Where we have a +maximum in this one. + +This is a one dimensional cut. + +And this one dimensional cut +has a maximum at this position. + +And by taking the derivative +of the total potential, + +you immediately find +this to be of that value. + +And now what we are +calculating next + +is what is the potential +energy at this point. + +And, well, this is just copy +from the notes, e to the 3/2. + +And now what we want +to do is we want + +to postulate that +for field ionization, + +this should be able to the +binding energy of the electron. + +Which is nothing +else than the Rydberg + +constant divided by n square. + +OK, now here, we +have the square root + +of the electric field +from this calculation. + +So that means the critical +electric field will scale as 1 + +over n to the 4. + +And this is a +famous scaling which + +can be found in many textbooks. + +That the critical electric +field for ionization equals, + +and now, that's the +beauty of atomic units, + +it is 1/16, n to the 4. + +Beautiful formula derived from +the settle point criteria. + +Of course, what I mean here is, +and if you do the derivation, + +it's in atomic units. + +Which means in units +of the atomic unit + +of the electric field which is +e over the Bohr radius squared. + +So it's a simple model. + +It's an analytic result. + +The question is is it valid? + +Does it make any sense? + +And the answer is yes, but in +a quantum mechanical problem, + +you would actually solve +Schroedinger's equation, + +such a potential. + +But then, the onset +of field ionization + +comes when tunnelling becomes +possible for this barrier. + +But it is the +nature of tunnelling + +that if you're a little bit too +low, tunneling is negligible. + +You may have ionization rates +of 1 per millisecond or so. + +And if you just go +a little bit closer, + +it becomes exponentially larger. + +So, therefore, this scaling +is very, very accurate. + +Because the transition where +you go from weak tunneling, + +to strong tunneling, to +spilling over the barrier, + +it's a very narrow range +of electric fields. + +But, yes, people have looked +at it in great details + +and have calculated +corrections due to tunneling. + +So these are quantum corrections +to the classical threshold + +which I just calculated. + +But now in hydrogen, a lot of +n, l mixing matrix elements, + +matrix elements due +to the electric field + +between an l states vanish. + +Hydrogen is just too +pure, too precise. + +There is actually +parabolic quantum numbers + +where you can +exactly diagonalize + +hydrogen electric fields. + +And you find some stable +states which do not decay. + +And they are above the +classical threshold + +we have just calculated. + +So as Dan Kleppner would have +said, the simplest of all atoms + +is the most complicated when +it comes to field ionization. + +Because it has a +lot of stable states + +above the classical barrier. + +So you can sort of +envision that there + +will be orbits which are +just confined to this region. + +And the electron never +samples the settle point. + +And if you look at it +this diagram on the wiki, + +these are actually +calculations for hydrogen + +which include ionization rates. + +You will find that +the states which + +are the ones which +go down, which + +are on the downhill side +of the electric field, + +you see always here marked +an onset for ionization. + +And then you see +a rapid increase + +in the ionization rate. + +But you also see +those hydrogenic state + +which go upward in energy +and they refuse to ionize. + +Because of the symmetry +of parabolic coordinates + +and the things I've mentioned. + +Anyway, it's too especially +to spend more time here + +in class on it, but I just +think you should at least know + +qualitatively what is +different for hydrogen. + +OK, so that's what +I wanted to tell you + +about high electric fields and +field ionization in principle. + +Let me now briefly mention +important applications + +of field ionization. + +One is close to 100% detection +efficiency for atoms. + +If you want to +detect single atoms, + +for instance, you'll +have a krypton sample + +and you want to find a +rare isotope of krypton + +for dating the material. + +You need an extremely +high sensitivity + +and you may just have a few +single atoms in the sample. + +One way to do it would be +that you excite the atom maybe + +through an intermediate +state, to Rydberg state. + +And then by just applying +a few volt per centimeter, + +you get an ion. + +And ions can be counted +by particle detectors. + +You can accelerate the ion, +smash it into a surface + +and count the particles with +close to 100% efficiency. + +And this is one of the most +sensitive detection schemes. + +I remember in the +aftermath of Chernobyl, + +there was an interest +in detection schemes + +for radioactive strontium. + +And on the wiki, I +give you a reference + +where some people developed +this resonance ionization + +spectroscopy for +some atomic isotopes. + +Which unfortunately +appeared more frequently + +after the Chernobyl disaster. + +And they developed +a method based + +on excitation to Rydberg states. + +Which was more sensitive +than other methods. + +You may ask why don't you +ionize it with a laser? + +Well, the fact is, you can +photoionize it with a laser. + +It's another alternative, but +it takes much more laser power. + +Because if you excite +into the continuum, + +the matrix element +is much smaller. + +And often, if you want to have +100% ionization probability + +to go into the continuum, you +need such high laser power + +that you may get some background +of resonant ionization + +of other elements and such. + +So Rydberg atoms is really +the smart way to go. + +You go to an almost bound to +an almost unbound electron. + +And then it's just +the electric field + +which causes the final +act of ionization. + +I also want to briefly mention +that the famous experiments + +on Rydberg atoms by +Herbert Walther and Serge + +Haroche and collaborators +would not have been possible + +without field ionization. + +I give you this one +reference, but I'm + +sure you'll find more +in the actually very, + +very nicely written Nobel +lecture of Serge Haroche. + +I just read it a few +weeks ago and it's + +a delight to read how +he exposes the field. + +So they did QED experiments by +having microwave transitions + +between atoms in two +highly excited states. + +Let's say with principal +quantum number 50 and 51. + +So that's now conveniently +in the microwave regime. + +Then those atoms are +passed through a cavity. + +And in this cavity, single atoms +interact with single photons. + +And they have done beautiful +quantum non-demolition + +experiments of single photons. + +I mean that's really wonderful, +state of the art experiments. + +Back to Rydberg atoms +and field ionization. + +Eventually, the read +out of those experiments + +was you prepare atoms +in the state 50 or 51. + +And afterwards, if they have +absorbed or emitted a photon, + +they should be in +a different state. + +So you were interested in a very +high detection efficiency which + +could distinguish +between 50 and 51. + +And of course there is a +way to distinguish that. + +And this is because +of n to the 4. + +You first apply +an electric field + +which can only field ionized 51. + +And then you allow +the atoms to propagate + +into a slightly +higher electric field. + +And then the 50s are ionized. + +So the standard +experiment is that you + +pass those atoms between +two field plates. + +And by putting an angle +between them that indicates + +the voltage is increasing. + +And then you have +two little holes. + +You have some channel-drawn +particle detectors. + +And the first detector +will detect the 51s + +and the second detector will +detect the lower lying states. + +So you can detect every +atom with high probability, + +but also in a state +selective way. + +So this way of doing state +selective field ionization + +based on the discussion +we had earlier, this + +is sort of the method of +choice for experiments + +involving Rydberg atoms. + +Any questions about atoms +in the electric fields? + +Well, then. + +Frequently we add +time dependence. + +So what we should +do next is atoms + +in oscillating electric fields. + +It's also a good way to +review what we have done. + +Because the first +thing to do now + +is we calculate the +polarizability for AC fields. + +We calculate the +AC Stark effect. + +And, of course, if in the AC +Stark effect we said omega 2, 0 + +will retrieve the +DC Stark effect. + +So in a way, what I'm +doing for you now is + +I'm using time dependent +perturbation theory + +to obtain a new result. + +But it will reproduce +the result of time + +independent perturbation theory +which we have just discussed. + +All right, so atoms in +oscillating electric fields. + +Of course the next +step is, and this + +is where we are +working towards, we + +will in the next few lectures +starting on Wednesday. + +Well, then there is Spring +Break, but in the next lectures + +develop a deep +understanding what + +happens when atoms +interact with light. + +And oscillating electric +fields is already + +pretty close to light. + +And I want to +actually also show you + +that we capture already a +lot of the phenomena which + +happen with light except +for a full understanding + +of spontaneous emission. + +So we pretty much when we use +an oscillating electric field, + +we allow the atom to +interact with just one + +mode of the +electromagnetic field. + +Which is filled with +a coherent state. + +And this is so classical +that we don't even + +need field quantization. + +We just use a classical +electric field. + +And this already gives us the +interaction of atoms with light + +except for spontaneous +emission which + +involves all the other modes. + +So that's what we do later. + +But today, we just do the +same classical description + +of an atom in an +oscillating electric field. + +And this is the theory +of the AC Stark effect. + +So all we do is application +of time dependent perturbation + +theory. + +So our electric field +is now time dependent. + +It has a value epsilon, +polarization e hat, + +and it oscillates. + +Our perturbation +Hamiltonian is exactly + +the same dipole Hamiltonian +we had before for the DC Stark + +effect. + +But now it's a +time dependent one. + +And it will be useful to break +up the oscillating term in e + +to the i omega, t and e +to the minus i omega t. + +I don't want to bore you with +perturbation theory in quantum + +mechanics because you've +all seen it in 805 or 806. + +I just want to +jump to the result. + +You find more details +about it on the wiki. + +But all you do is you +parametrize your wave function, + +you expand it into +eigenstates with amplitude an. + +And then you put it into +the Schroedinger equation + +and assume that for +short times the atom + +is in the ground state. + +The amplitude of the +ground state is 1. + +And the amplitude +of the excited state + +is infinitesimal that you +can use the lowest order + +perturbation. + +This immediately gives +you the first order result + +for the amplitude in +an excited state, k. + +It only comes about because +your initial state, the ground + +state, is coupled by the matrix +element to the excited state. + +It's linear in the +applied electric field. + +So what you do is you have +the Schroedinger equation + +and you integrate it +from times 0 to time 1. + +And since you have e +to the i omega, t and e + +to the minus i omega t, you +get two time dependent terms. + +e to the i. + +So what appears now is we +have the frequencies omega + +n of the excited state. + +And now when we couple +the excited state, k, + +to the ground +state, what appears + +is the frequency +difference between the two. + +That's pretty much +the excitation gap. + +And we have a time dependent +oscillation at omega. + +And then we have, of +course, the same term + +where we flip the +sign from omega-- + +let me write that more clearly. + +Where we flip the sign +from omega to minus omega. + +So that's the second term. + +By integrating an exponential +function with respect to time, + +we get an energy and a frequency +denominator which is this one. + +So this is really +just straight forward, + +most basic plain +vanilla application + +of perturbation theory. + +The only thing I want to +discuss because it sometimes + +confuses people is +that we integrate + +from times 0 to the finite time. + +And then you integrate, +you get contributions + +from the upper +integration limit. + +And from the lower +integration limit. + +And this contribution at +the lower integration limit + +is actually a transient. + +It is at the frequency. + +It doesn't depend on omega. + +So it's a beat node between +the ground and excited state. + +I could say at +frequency omega k, + +but then it's together with the +ground state, it's omega kg. + +And this is due to if you +switch on a perturbation, + +it's like you suddenly +switch on the drive + +of an harmonic oscillator. + +And you have some ringing. + +You have a transient at +the natural frequency + +of the harmonic oscillator. + +It has nothing to +do with the drive. + +It's just a sudden onset. + +It's transient and frequent +due to the sudden switch on. + +So like any +transient, we haven't + +included damping in here. + +We don't have +spontaneous emission. + +Everything is undamped. + +But eventually, all +those transients + +will damp out with time. + +And as we should have known +also from the beginning, + +when we drive a system, when +we switch on a perturbation, + +just think about an +harmonic oscillator. + +You have a response at the +harmonic oscillator frequency + +which is always +transient in nature. + +And then you have a response +at the dry frequency. + +And we are +interested, of course, + +only in the driven response +The driven response + +is at frequency +plus minus omega. + +That's how we drive it. + +But now I have to +be careful since I'm + +looking at the amplitude and I +factor out the time dependence + +of the time dependence of +the wave function, the time + +dependence of the eigenstates. + +I'm now looking for drive +terms in this expression + +for the amplitude which +are at frequency omega, + +but modified by the ground. + +Or the frequency of +the ground state. + +But anyway, what I mean +is the relevant term + +is the one which +depends on omega. + +And in the following discussion, +I simply drop the minus 1 + +because it's a transient. + +If you would switch on your +time dependent electric field + +in a smoother way, this +term would disappear. + +OK, let's now be specific. + +Let's assume the electric field +points in the z direction. + +For an isotropic medium, +the dipole moment, + +the time dependent dipole +moment which we induce + +is also pointing +in the z direction. + +And so we want to calculate now +what is the dipole moment which + +is created by the drive term? + +By the driven electric Field + +And for that, we simply +use the perturbation theory + +we have just applied. + +We take the ground state and +its first order correction. + +And calculate the expectation +value of the dipole moment. + +In the line at the top, we +have the first order correction + +to the ground state +wave function. + +And so we just plug it in. + +And what we obtain +is result where + +we have the matrix +elements squared. + +Remember, we do first +order perturbation theory + +which is one occurrence +of the matrix element, + +but now we take a +second matrix element + +because we're interested +in the dipole operator. + +So this gives us now a sum +over matrix element squared. + +We have e to the plus i omega +t and e to the minus i omega t. + +This means we get 2 times the +real part of this expression. + +And the time dependent +term is e to the i omega t. + +And then we have the term +with plus and minus omega. + +Yes. + +And so, most +importantly, everything + +is driven by the electric field. + +We can now just to write +the result in an easier way, + +we can use this result +with omega minus omega. + +And the real part +and write that. + +We can write that as +2 times omega k, g. + +Omega k, g squared minus omega +squared, times cosine omega t, + +times the electric field. + +And now finally, we +have the matrix element. + +We have integrated the e to the +i omega t function and such. + +So what we have here now is the +time dependent electric field. + +And what we have +here is the factor + +by which we multiply +the electric field + +to obtain the bipole moment. + +And this is the +definition of the now + +time dependent or frequency +dependent polarizability. + +AUDIENCE: Excuse me. + +PROFESSOR: Yes? + +AUDIENCE: Why are we only +getting the cosine and not + +[INAUDIBLE]? + +You only multiply by the other +terms to get the [INAUDIBLE]? + +In terms of the cosine. + +PROFESSOR: I haven't +done the math yesterday + +when I prepared for the class. + +I did it a while ago +when I wrote those notes, + +but you know, one comment, I +know you don't want to hear it, + +but it's a following. + +This system has no +dissipation at all. + +And when I drive +it, I will always + +get a response which is +in phase with the drive. + +It can be cosine omega t, +or minus cosine omega t. + +You cannot get a +quadrature at this point. + +So if you find I've made a +mistake, and you would say, + +there is a sine, omega +term, I've made a mistake. + +I know for physical reasons, +I cannot get a phase shift. + +You only get a phase shift +in the response of a system + +to drive when you +have dissipation. + +AUDIENCE: OK. + +I'll have to talk with you. + +PROFESSOR: But why +don't-- I mean, + +I know the result is correct. + +And this is just, I +hate to spend class time + +in trying to figure out +if I've omitted one term. + +AUDIENCE: The real part. + +PROFESSOR: But the real part +what I've probably done is-- + +AUDIENCE: I think that's +probably what you did. + +Yeah. + +Thank you. + +PROFESSOR: I think +that's what I did. + +So let me, therefore, +also say we have now + +included the real part of it. + +Yes. + +OK, thank you. + +OK, this part here +can actually-- + +that's how we often report. + +And that's how you often +find in textbook the result, + +the frequency dependence +of the AC polarizability. + +But I like to rewrite it +now in a different way which + +is identical. + +And it shows now that there +are two contributions. + +And I will discuss +them in a moment. + +But those two contributions, +one has in the denominator, + +let's assume we excite the +system close to resonance. + +Omega is close to omega kg. + +Then one term is +much, much closer. + +It's to a near +resonant excitation. + +And from our discussion +about rotating frames, + +we have all of this near +resonant excitation corresponds + +to a corotating term. + +And the other one corresponds +to a counter rotating term. + +We've not assumed any +rotating fields here, + +but we find those terms with +the same mathematical signature. + +And I will discuss +that little bit later. + +But the physics is between the +corotating and counterrotating + +term. + +And it's the +corotating term which + +is the term which [INAUDIBLE] +the so-called rotating + +wave approximation. + +I just want to identify +those two terms + +and let's hold the thought for +until we have the discussion. + +What I first want to say +is the limiting case. + +We have not made any +assumptions about frequency. + +When we let omega go to 0, +we obtain the DC result. + +It is important to point +out that when we have the DC + +result, we can only get to +correct results because we have + +equal contributions from co +and counterrotating terms. + +So that's sort of a +question one could ask. + +You know, which mistake do you +do for the DC polarizability + +when you do the rotating +wave approximation? + +Well, you miss out +on exactly 50% of it. + +Because both terms +become equally important. + +I have deliberately focused +here on the calculation + +of the dipole moment. + +Because the dipole, I simply +calculated the dipole moment + +as being proportion +to the electric field. + +And the coefficient in front of +it is alpha the polarizability. + +You may remember that +when we calculated + +the effect of a +static electric field, + +we looked for the DC Stark shift +for the shift of energy levels. + +We can now discuss also +the AC Stark shift. + +Which is a shift of the +energy levels due to the time + +dependent field. + +But I have to say you have +to be a little bit careful. + +And sometimes when I looked +at equations like this, + +there is a moment of confusion +what you want to actually, + +what the question is. + +Because the wave function is now +a time dependent wave function. + +It's a driven system. + +It's no longer your time +independent Schroedinger + +equation and you +are asked, what is + +the shift in the +value of eigenvalues? + +So the AC Stark +shift here is now + +given by the frequency +dependent polarizability. + +And then, and I know some +textbooks do it right away. + +And at the end of the +day, it may confuse you. + +It uses an average of e square. + +So in other words, if you +have an electric field which + +is cosine omega t, and you +calculate what is the AC Stark + +shift, you get +another factor of 1/2. + +Because cosine square omega +t time average is 1/2. + +So anyway, just +think about that. + +It's one of those factors +of 1/2 which is confusing. + +Will, you have a question? + +AUDIENCE: So when +we take omega goes + +to 0 from our previous +results, are we still justified + +in neglecting the +transient term? + +PROFESSOR: Yes. + +But why? + +What will happen is +the transient term + +is really a term which +has time dependence. + +And even if omega is 0, +just the step function + +of switching it on +creates an oscillation + +in the atom at a frequency +which is omega excited + +state minus omega ground state. + +You may think +about it like this. + +I give you more the +intuitive answer. + +Take an atoms and put +it in electric field. + +If you gradually switch +on the electric field, + +you create a dipole moment +by mixing at 0 frequency + +a p state into the s state. + +And that displaces the +electron from the origin. + +But if you suddenly switch +on the electric field, + +you actually create a +response of the atoms which + +has a beat node between the +excitation frequency of the p + +state and the excitation +frequency of the s state. + +And what you regard is the +DC response of the atom + +is everything except +for this transient term. + +However, and this tells +you maybe something + +about the different formulas +in quantum mechanics + +when we talked about the +time independent perturbation + +theory. + +We never worried +about the switch + +on because we just did time +independent perturbation theory + +and we sort of assumed that the +perturbation term had already + +existed from the +beginning of the universe. + +So it's not that we +excluded the term. + +We formulated the +theory in such a way + +that the term just +didn't appear. + +But if you switch on a DC +field, you should actually + +if you want an +accurate description, + +do time dependent +perturbation theory, + +you get the transient +term even for DC field. + +And then you discuss +it away the way I did. + +OK, so if you want, these +are the textbook results. + +We could stop here. + +But I want to add three +points to the discussion. + +You can also see at +this point, we really + +understand that AC +Stark shift theory + +as you find it in generic +quantum mechanics textbooks. + +And now I want to give +you a little bit of sort + +of extra insight based on my +knowledge of atomic physics. + +So there are three points I +would like to discuss here. + +The first one is the relation +to the dressed-atom picture. + +The second one is I want +to parametrize the results + +for the polarizability using +the concept of oscillator + +strengths. + +And thirdly, I want +to tell you how + +you can, already at this point, +take our result for the AC + +polarizability and calculate +how do atoms absorb light + +and what is the dispersive +phase shift which atoms generate + +when they're exposed to light. + +Or in other words, +I want to show you + +that based on this +simple result, + +we have pretty much already +all the information we need + +to understand how absorption +imaging and dispersive + +imaging is done +in the laboratory. + +So these are the +three directions + +I would like to take it. + +So let's start with number one. + +The relation to +the dressed-atom. + +So what I want to show you now +is that a result we obtained + +in time dependent +perturbation theory, + +we could've actually obtained +in time independent perturbation + +theory by not using a +coherent electric field which + +oscillates. + +But just assuming that +they're stationary Fock states + +of photons. + +And this is actually the +dressed-atom picture. + +I know I'm throwing now a +lot of sort of lingo at you. + +It's actually +very, very trivial. + +But I want to show you that you +have a result where if you just + +open your eyes, you see actually +the dressed-atom shining + +through. + +So what we had is we had +an energy shift here. + +Which was let me just +summarize what we have derived. + +Was this result with +a polarizability + +which we derived. + +And let me rewrite the +results from above. + +So this is why I made the +remark about the averaging + +of the electric field. + +If you combine it +with, as you will see, + +Rabi frequencies and +dressed-atom picture, + +you'll need the amplitude +of the electric field. + +And formulated in the amplitude +of the electric field, + +you have a one quarter. + +And this is not a mistake. + +And you can really trace +it down to the time + +average of the cosine term. + +OK, so this is now-- I'm really +copying from the previous page. + +We had the difference frequency +between state 1 and state 2. + +So I'm simply assuming +that we couple two states. + +Now an s and p +state, If you want. + +We have a matrix +element which is + +the matrix element of +the position operator, + +z, between state 1 +and state 2 squared. + +We have an energy denominator +which was this one. + +And we have-- so I'm just +rewriting the previous result. + +But now I usually +hate matrix elements + +when they appear in an equation. + +I mean, who knows +matrix elements. + +What is the relevant +thing when we + +couple two different states +is the Rabi frequency. + +Frequency units is what we want. + +So, therefore, I have +prepared the formula + +that I can take +the matrix element + +with the electric field. + +And this is nothing else than +the Rabi frequency squared. + +Or actually, one is +measured as energy units. + +The other is frequency units. + +So there is an h bar square. + +So, therefore, I have +now written this result + +in what I think is a more +physically insightful way + +by explicitly identifying +the Rabi frequency which + +couples ground and +excited states. + +And I also want +to separate, want + +to introduce the +detuning of the time + +dependent oscillating +electric field from resonance. + +And then I obtain this result. + +Doesn't it look so much simpler +than what we had before? + +And it has a lot of +physics we can discuss now. + +One over delta is sort +of like an AC Stark + +effect in one limit. + +It's a far-off resonant case of +an optical trapping potential. + +So this formula has +a lot of insight + +which I want to provide now. + +The second part I give you the +name and the interpretation + +will become obvious in a moment. + +Is the important +Bloch-Siegert shift. + +It is the AC Stark shift due +to the counterrotating term. + +So what I'm motivating here +is just don't get confused. + +What I write down +is very simple. + +And I sometimes use advanced +language for those of you + +who have heard those buzz words. + +But what I really mean +is what I want to discuss + +and you to follow are the +simple steps we do here. + +So anyway, what +I've just done is + +I've rewritten the result +from the previous page + +by just introducing +what I suggest + +as more physically +appealing symbols. + +And now I want to remind you +that this result for the AC + +Stark effect doesn't it look +very similar not to a result, + +to the standard result of +time independent perturbation + +theory? + +And, of course, you +remember that in time + +independent +perturbation theory, you + +get an energy shift which is +the square of a matrix element + +divided by detuning. + +So it seems when we inspect +our result for the AC Stark + +effect which came from time +dependent perturbation theory, + +that this result here has +actually-- if we map it + +on time independent perturbation +theory, it has two terms. + +Both coupled by +the Rabi frequency. + +But one has a detuning of delta. + +And the other has a detuning +of minus 2 omega, minus delta. + +So it seems that the result +for the AC Stark shift + +can be completely understood +by a mixture of not one, + +but two different states +with different detunings. + +And this is exactly +what we will do + +in 8.422 in the +dressed-atom picture + +when we have quantized +the electromagnetic field. + +In other words, we have photons. + +Because then what we +have is the following. + +We have the ground state +with n photons, n gamma. + +Well, there are sort of +n quanta in the system. + +n photons. + +But what we can do is we can now +have one quantum of excitation + +with the atom. + +And n minus 1 photon. + +So it's almost like +absorbing a photon. + +And this state has +a detuning of delta. + +But then we can also +consider an excited state. + +In other words, here, we +connect to the excited state + +by absorbing a photon. + +But we can also, we talk +about it more later, + +we can also connect +to the excited state + +by emitting a photon. + +So this state has now not +one quantum of excitation, + +there's three quanta +of excitation. + +One in the atom and +two in the photon. + +So, therefore, its detuning +is now much, much larger. + +Actually, if we're on +resonant, the detuning + +would be just 2 omega. + +But if you are detuned, +there is the delta. + +So in other words, +we can just say + +if it would do +time independent-- + +I'm not doing it here. + +And I leave kind +of all the beauty + +to when we discuss the +dressed-atom picture + +in its full-fledged version. + +But all I'm telling you is that +the result for the AC Stark + +shift looks like type +independent perturbation theory + +with those two detunings. + +And I'm now offering you the +physical picture behind it + +by saying, look, when we +have the ground state with n + +photons, and we have +those two other states, + +they have exactly the detuning +which our results suggests. + +And yes, indeed, if you look at +the many folds for those three + +states and we would simply do +time independent perturbation + +theory, we would find exactly +the same frequency shifts, + +the AC Stark shift +as we just obtained + +in a time dependent picture. + +So in other words, what +I'm telling you is there + +are two ways to obtain +the AC Stark shift. + +One is you do time dependent +perturbation theory assuming + +oscillating electric field. + +And that would mean in +the quantized language + +you assume the electromagnetic +field is in a coherent state. + +Alternatively, you can +quantize the electric field + +and introduce Fock states. + +And then because Fock +states are type independent, + +then these are the eigenstates +of the electromagnetic field + +in a cavity. + +And now you obtain the +same atomic level shift + +in time independent +perturbation theory. + +So in other words, we can +have photon number states. + +And do time independent +perturbation theory. + +Or alternatively, we can use a +semi-classical electric field. + +Which means we have a +classical electric field. + +And then we can treat +it in time dependent. + +All the textbooks generally +use the latter approach. + +Because it uses a same +classical electric field. + +But I can tell you, I strongly +prefer the first approach. + +Because in the +first approach, you + +have no problems whatsoever. + +What is the time +dependent wave function? + +What is an energy level shift +when you have a driven system? + +In a time independent +way, everything just + +is simple and right +there in a simple way. + +But it's two different +physical regimes. + +Questions? + +OK, second point of +discussion is the concept + +of the oscillator strengths. + +So what I'm teaching in +the next five minutes + +is so old-fashioned +that I sometimes + +wonder should I still +teach it or not. + +On the other hand, you find +it in all the textbooks. + +You also want to understand +a little bit the tradition. + +And at least I'm giving +you some motivation + +to learn about it that if +I parametrize the matrix + +element with an +oscillators strength. + +And most of your atoms, +most of the alkali atoms + +have an oscillator +strength for the s + +to p transition for the D-lines. + +Which is unity. + +You can actually write down +what is the matrix element. + +What is the spontaneous lifetime +of your atom without knowing + +anything about atomic structure. + +Just memorizing that f equals +1, the oscillator strength + +is 1 is pretty much all you +have to know about your atom. + +And the rest, the only +other thing you have to know + +is what is the resonant +frequency of your laser? + +780 nanometer? + +589 nanometer? + +671 nanometer? + +So the modern motivation for +this old-fashioned concept + +is for simple atoms where +the oscillator strength + +is close to 1, this is +probably the parametrization + +you want to use +because you can forget + +about the atomic structure. + +So but the derivation +would go as follows. + +I want to compare our result. + +How an atom responds +to an electric field. + +I want to compare this +result to the result + +of a classical oscillator. + +So compare our result +for the AC polarizability + +to a classical +harmonic oscillator. + +So I assume this classical +harmonic oscillator + +has a charge, a mass +term, and a frequency. + +And both the atom and the +classical harmonic oscillator + +are driven by the time +dependent electric field. + +Which we have already +parametrized by cosine omega t. + +OK. + +If you look at the classical +harmonic oscillator, + +you find that the-- +you drive it at omega + +and ask what is it time +dependent dipole moment? + +It's driven by the cosine term. + +And what I mean, of +course, is dipole moment + +of a classical +harmonic oscillator + +is nothing else than +charge times displacement. + +And, well, if you +spend one minute + +and solve the equation for the +driven harmonic oscillator, + +you find that the response, +the amplitude, the steady state + +amplitude, [? zk ?] of +the harmonic oscillator + +is cosine omega t. + +Times a prefactor which +I'm writing down now. + +There is this resonant behavior. + +So that's the response of the +classical harmonic oscillator. + +And yeah. + +So this is just classical +harmonic oscillator physics. + +And I now want to +define a quantity which + +I call the oscillator +strength of the atom. + +So I'm just jumping now from the +harmonic oscillator to the atom + +and then I combine a the two. + +And the oscillator +strength is nothing else + +than a parametrization +of the matrix element + +with between different states. + +But it's dimensionless. + +And it's made dimensionless +by using the mass. + +By using h-bar. + +And by using the +transition frequency. + +So the atomic-- let me just +make sure we take care of it. + +This is the result for the +classical harmonic oscillator. + +And this is now the +result for the atom + +that we have found already they +the result for the atom before. + +And now I'm rewriting +it simply by expressing + +the matrix element square +by the oscillator strength. + +And this here is just +another expression + +for the polarizability alpha. + +Well, let's now +compare the result + +of a quantum mechanical +atom exactly described + +by time dependent +perturbation theory + +to the result of a classical +harmonic oscillator. + +The frequency +structure is the same. + +So if I would know say +we have an ensemble + +of harmonic oscillators, +and the harmonic oscillators + +may have different frequencies +and different charges. + +Then I have made those +formulas exactly equal. + +And I can now formulate +that the atom reacts + +to an electric field to time +dependent electric field. + +Exactly as an ensemble +of classical oscillators + +with effective charge. + +If I would say I have an +ensemble of oscillators + +with effective charge, +then the response + +of the atom and the +response of the ensemble + +of classical oscillators +is absolutely identical. + +So the atom response is a +set classical oscillators + +with an effective charge +which is given here. + +So, therefore, you +don't have to go further + +if you want to have any +intuition how an atom reacts + +to light. + +The classical +harmonic oscillator + +is not an approximation. + +It is exact. + +So that result is +relevant because it + +allows us to clearly formulate +the classical correspondence. + +The second thing is +as you can easily + +show with basic +commutator algebra, + +there is the Thomas +Kuhn sum rule + +which is discussed in all +texts in quantum physics + +which says that the sum over +all oscillator strengths is 1. + +So, therefore, we know +if we have transitions + +from the ground state +to different states, + +the sum of all the oscillator +strengths to all the states + +can only be 1. + +And another advantage of the +formulation with oscillator + +strength is that it is +a dimensionless unit. + +It's a dimensionless +parameter which tells us + +how the atom corresponds to an +external electromagnetic field. + +I just need two or +three more minutes + +to show you what that means. + +If you have hydrogen, +the 1s to 2p transition + +is the strongest transition. + +And it has a matrix +element which + +corresponds to an oscillator +strength of about 0.4. + +So the rest comes from +more highly excited states. + +However, for alkali atoms, the +D-line, the s to p transition + +has an oscillator strength. + +I didn't write down +the second digit, + +but it's with excellent +approximation, 1.98 + +or something. + +So not just qualitatively, +almost quantitatively, + +you capture the response from +the atom by saying f equals 1. + +So if you use for the +alkali atoms f equals 1, + +then simply the transition +frequency of the D-line + +gives you the +polarizability alpha. + +And as we will see later, +because we haven't introduced + +it is, but it will also give you +gamma the natural line beats. + +Because all the coupling to +the electromagnetic field + +to an external field is +really captured by saying what + +the matrix element is. + +And f equals 1 is +nothing else than saying + +the matrix element +is such and such. + +And, indeed, if I now use the +definition of the oscillator + +strength in reverse, +the matrix element + +between two transitions, +between two states + +is the matrix element squared +is the oscillator length + +times one half. + +And if you just go back +and look at the formula, + +you find that this +is now dimensionless. + +So we need now because the left +hand side is the length square, + +we need two lengths. + +One is the Compton wave length +which is h-bar over 2 times + +the mass of the electron. + +And lambda bar is the +transition wave lengths, + +lambda divided by 2 pi. + +So, therefore, I haven't found +it anywhere in textbooks, + +but this is my sort +of summary of this. + +If you have a strong +transition, and strong + +means that the oscillator +length is close to 1, + +then the matrix element +for the transition + +is approximately +the geometric mean + +of the Compton wave +length of the electron. + +And the reduced wave lengths +of the resonant transition. + +So now if you want +to know what is + +the matrix element for +the d-line of rubidium, + +take the wave length +of 780 nanometer. + +Take the Compton wave +lengths of the electron + +and you get an +accurate expression. + +I know time is over. + +Any questions? + +All right. \ No newline at end of file diff --git a/jwh7LqjT4w0.txt b/jwh7LqjT4w0.txt new file mode 100644 index 0000000000000000000000000000000000000000..4768072dd1e2877e257ed99da16b2be5af730371 --- /dev/null +++ b/jwh7LqjT4w0.txt @@ -0,0 +1,10523 @@ +align:start position:0% + +the following content is provided 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courses + + align:start position:0% +materials from hundreds of MIT courses + + + align:start position:0% +materials from hundreds of MIT courses +visit MIT opencourseware at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +so welcome back everybody + + align:start position:0% +so welcome back everybody + + + align:start position:0% +so welcome back everybody +so this is the final exam a checklist so + + align:start position:0% +so this is the final exam a checklist so + + + align:start position:0% +so this is the final exam a checklist so +with a single oscillator we need to make + + align:start position:0% +with a single oscillator we need to make + + + align:start position:0% +with a single oscillator we need to make +sure that you know how to write down the + + align:start position:0% +sure that you know how to write down the + + + align:start position:0% +sure that you know how to write down the +equation of motion we have discussed + + align:start position:0% +equation of motion we have discussed + + + align:start position:0% +equation of motion we have discussed +about damped under damped critically + + align:start position:0% +about damped under damped critically + + + align:start position:0% +about damped under damped critically +damped and oba tempered attached + + align:start position:0% +damped and oba tempered attached + + + align:start position:0% +damped and oba tempered attached +oscillators and we have tried to drive + + align:start position:0% +oscillators and we have tried to drive + + + align:start position:0% +oscillators and we have tried to drive +oscillators and we observe transient + + align:start position:0% +oscillators and we observe transient + + + align:start position:0% +oscillators and we observe transient +behavior and steady state solution + + align:start position:0% +behavior and steady state solution + + + align:start position:0% +behavior and steady state solution +resonance right so which we actually + + align:start position:0% +resonance right so which we actually + + + align:start position:0% +resonance right so which we actually +demonstrated lab by breaking glass and + + align:start position:0% +demonstrated lab by breaking glass and + + + align:start position:0% +demonstrated lab by breaking glass and +then we move on and try to cup or + + align:start position:0% +then we move on and try to cup or + + + align:start position:0% +then we move on and try to cup or +multiple object together and that brings + + align:start position:0% +multiple object together and that brings + + + align:start position:0% +multiple object together and that brings +us to the capital system what are the + + align:start position:0% +us to the capital system what are the + + + align:start position:0% +us to the capital system what are the +normal modes and how to issues of and + + align:start position:0% +normal modes and how to issues of and + + + align:start position:0% +normal modes and how to issues of and +minus 1 k matrix eigenvalue problem + + align:start position:0% +minus 1 k matrix eigenvalue problem + + + align:start position:0% +minus 1 k matrix eigenvalue problem +right and what is actually for solution + + align:start position:0% +right and what is actually for solution + + + align:start position:0% +right and what is actually for solution +for the description cup of the system + + align:start position:0% +for the description cup of the system + + + align:start position:0% +for the description cup of the system +and can we actually drive the Chabad + + align:start position:0% +and can we actually drive the Chabad + + + align:start position:0% +and can we actually drive the Chabad +system and we found out we can and also + + align:start position:0% +system and we found out we can and also + + + align:start position:0% +system and we found out we can and also +the system will respond as well similar + + align:start position:0% +the system will respond as well similar + + + align:start position:0% +the system will respond as well similar +to what we have see in the single + + align:start position:0% +to what we have see in the single + + + align:start position:0% +to what we have see in the single +oscillator case we see resonance as well + + align:start position:0% +oscillator case we see resonance as well + + + align:start position:0% +oscillator case we see resonance as well +we can excite one of the normal mode by + + align:start position:0% +we can excite one of the normal mode by + + + align:start position:0% +we can excite one of the normal mode by +driving the cup of the system and then + + align:start position:0% +driving the cup of the system and then + + + align:start position:0% +driving the cup of the system and then +we put more and more objects and until + + align:start position:0% +we put more and more objects and until + + + align:start position:0% +we put more and more objects and until +at some point we have infinite number of + + align:start position:0% +at some point we have infinite number of + + + align:start position:0% +at some point we have infinite number of +capital of object what is issued a + + align:start position:0% +capital of object what is issued a + + + align:start position:0% +capital of object what is issued a +solution of refraction and the + + align:start position:0% +solution of refraction and the + + + align:start position:0% +solution of refraction and the +transmission refraction and the + + align:start position:0% +transmission refraction and the + + + align:start position:0% +transmission refraction and the +translation symmetric system I so that + + align:start position:0% +translation symmetric system I so that + + + align:start position:0% +translation symmetric system I so that +is actually a discussion of symmetry we + + align:start position:0% +is actually a discussion of symmetry we + + + align:start position:0% +is actually a discussion of symmetry we +go to the continue limit we actually + + align:start position:0% +go to the continue limit we actually + + + align:start position:0% +go to the continue limit we actually +found wave and wave equations right so + + align:start position:0% +found wave and wave equations right so + + + align:start position:0% +found wave and wave equations right so +we found that partly we make the phase + + align:start position:0% +we found that partly we make the phase + + + align:start position:0% +we found that partly we make the phase +transition from single object vibration + + align:start position:0% +transition from single object vibration + + + align:start position:0% +transition from single object vibration +to waves and that is issue achievement + + align:start position:0% +to waves and that is issue achievement + + + align:start position:0% +to waves and that is issue achievement +we have done in 3 and we have discussed + + align:start position:0% +we have done in 3 and we have discussed + + + align:start position:0% +we have done in 3 and we have discussed +about different systems massive string + + align:start position:0% +about different systems massive string + + + align:start position:0% +about different systems massive string +massive spring song wave electromagnetic + + align:start position:0% +massive spring song wave electromagnetic + + + align:start position:0% +massive spring song wave electromagnetic +waves and we have discussed the progress + + align:start position:0% +waves and we have discussed the progress + + + align:start position:0% +waves and we have discussed the progress +a progressive wave and standing waves + + align:start position:0% +a progressive wave and standing waves + + + align:start position:0% +a progressive wave and standing waves +for the bound system we have also normal + + align:start position:0% +for the bound system we have also normal + + + align:start position:0% +for the bound system we have also normal +modes and we discuss about how to + + align:start position:0% +modes and we discuss about how to + + + align:start position:0% +modes and we discuss about how to +actually do food year decomposition and + + align:start position:0% +actually do food year decomposition and + + + align:start position:0% +actually do food year decomposition and +what is actually the physical meaning of + + align:start position:0% +what is actually the physical meaning of + + + align:start position:0% +what is actually the physical meaning of +food area basi decomposition in L 3 and + + align:start position:0% +food area basi decomposition in L 3 and + + + align:start position:0% +food area basi decomposition in L 3 and +4 the infinite system we also learned + + align:start position:0% +4 the infinite system we also learned + + + align:start position:0% +4 the infinite system we also learned +about food year transform and + + align:start position:0% +about food year transform and + + + align:start position:0% +about food year transform and +uncertainty principles and we actually + + align:start position:0% +uncertainty principles and we actually + + + align:start position:0% +uncertainty principles and we actually +learn to your pride boundary conditions + + align:start position:0% +learn to your pride boundary conditions + + + align:start position:0% +learn to your pride boundary conditions +so that actually we constrained the + + align:start position:0% +so that actually we constrained the + + + align:start position:0% +so that actually we constrained the +possible wavelengths of the normal modes + + align:start position:0% +possible wavelengths of the normal modes + + + align:start position:0% +possible wavelengths of the normal modes +and therefore we also learned about how + + align:start position:0% +and therefore we also learned about how + + + align:start position:0% +and therefore we also learned about how +to as we put a system or together and + + align:start position:0% +to as we put a system or together and + + + align:start position:0% +to as we put a system or together and +finally how to actually determine the + + align:start position:0% +finally how to actually determine the + + + align:start position:0% +finally how to actually determine the +dispersion relation which is Omega as a + + align:start position:0% +dispersion relation which is Omega as a + + + align:start position:0% +dispersion relation which is Omega as a +function of K the web number so until + + align:start position:0% +function of K the web number so until + + + align:start position:0% +function of K the web number so until +now we actually discuss idealize the + + align:start position:0% +now we actually discuss idealize the + + + align:start position:0% +now we actually discuss idealize the +system and we also move on to discuss + + align:start position:0% +system and we also move on to discuss + + + align:start position:0% +system and we also move on to discuss +dispersive medium so we have learned + + align:start position:0% +dispersive medium so we have learned + + + align:start position:0% +dispersive medium so we have learned +some more even more about dispersion + + align:start position:0% +some more even more about dispersion + + + align:start position:0% +some more even more about dispersion +relation for a dispersive medium and the + + align:start position:0% +relation for a dispersive medium and the + + + align:start position:0% +relation for a dispersive medium and the +signal transmission how to issue the + + align:start position:0% +signal transmission how to issue the + + + align:start position:0% +signal transmission how to issue the +send signal right through highly + + align:start position:0% +send signal right through highly + + + align:start position:0% +send signal right through highly +dispersive medium right that the + + align:start position:0% +dispersive medium right that the + + + align:start position:0% +dispersive medium right that the +solution we were proposing is to use a + + align:start position:0% +solution we were proposing is to use a + + + align:start position:0% +solution we were proposing is to use a +amplitude modulation + + align:start position:0% +amplitude modulation + + + align:start position:0% +amplitude modulation +modulation radio and as of the problem + + align:start position:0% +modulation radio and as of the problem + + + align:start position:0% +modulation radio and as of the problem +of dispersion and group velocity and + + align:start position:0% +of dispersion and group velocity and + + + align:start position:0% +of dispersion and group velocity and +phase velocity we covered that and also + + align:start position:0% +phase velocity we covered that and also + + + align:start position:0% +phase velocity we covered that and also +as I mentioned before the uncertainty + + align:start position:0% +as I mentioned before the uncertainty + + + align:start position:0% +as I mentioned before the uncertainty +principle a 2 3 as the assistance so we + + align:start position:0% +principle a 2 3 as the assistance so we + + + align:start position:0% +principle a 2 3 as the assistance so we +have bound system which we have no more + + align:start position:0% +have bound system which we have no more + + + align:start position:0% +have bound system which we have no more +modes for 2 dimensional and 3 + + align:start position:0% +modes for 2 dimensional and 3 + + + align:start position:0% +modes for 2 dimensional and 3 +dimensional systems as well you can see + + align:start position:0% +dimensional systems as well you can see + + + align:start position:0% +dimensional systems as well you can see +no more will appraise so to just make + + align:start position:0% +no more will appraise so to just make + + + align:start position:0% +no more will appraise so to just make +sure that you know how to actually + + align:start position:0% +sure that you know how to actually + + + align:start position:0% +sure that you know how to actually +derive all those standing waves for a + + align:start position:0% +derive all those standing waves for a + + + align:start position:0% +derive all those standing waves for a +different dimension of system + + align:start position:0% +different dimension of system + + + align:start position:0% +different dimension of system +and we actually showed and approved + + align:start position:0% +and we actually showed and approved + + + align:start position:0% +and we actually showed and approved +geometrical optics which is actually a + + align:start position:0% +geometrical optics which is actually a + + + align:start position:0% +geometrical optics which is actually a +direct consequence of waves wavefunction + + align:start position:0% +direct consequence of waves wavefunction + + + align:start position:0% +direct consequence of waves wavefunction +continuation of the wave function the + + align:start position:0% +continuation of the wave function the + + + align:start position:0% +continuation of the wave function the +boundary condition and we learned about + + align:start position:0% +boundary condition and we learned about + + + align:start position:0% +boundary condition and we learned about +the refraction duel and those of Snell's + + align:start position:0% +the refraction duel and those of Snell's + + + align:start position:0% +the refraction duel and those of Snell's +law we talked about polarize the waves + + align:start position:0% +law we talked about polarize the waves + + + align:start position:0% +law we talked about polarize the waves +linear the circularly polarized + + align:start position:0% +linear the circularly polarized + + + align:start position:0% +linear the circularly polarized +elliptically polarized and the polarizer + + align:start position:0% +elliptically polarized and the polarizer + + + align:start position:0% +elliptically polarized and the polarizer +and quarter wave plate and at the end of + + align:start position:0% +and quarter wave plate and at the end of + + + align:start position:0% +and quarter wave plate and at the end of +the discussion of two shitty system we + + align:start position:0% +the discussion of two shitty system we + + + align:start position:0% +the discussion of two shitty system we +actually discussed about how to actually + + align:start position:0% +actually discussed about how to actually + + + align:start position:0% +actually discussed about how to actually +generate electromagnetic wave by + + align:start position:0% +generate electromagnetic wave by + + + align:start position:0% +generate electromagnetic wave by +accelerated charge okay finally we went + + align:start position:0% +accelerated charge okay finally we went + + + align:start position:0% +accelerated charge okay finally we went +on and talked about how those young + + align:start position:0% +on and talked about how those young + + + align:start position:0% +on and talked about how those young +waves propagate in Thai electrics and + + align:start position:0% +waves propagate in Thai electrics and + + + align:start position:0% +waves propagate in Thai electrics and +again boundary condition which these two + + align:start position:0% +again boundary condition which these two + + + align:start position:0% +again boundary condition which these two +interesting phenomena which belongs only + + align:start position:0% +interesting phenomena which belongs only + + + align:start position:0% +interesting phenomena which belongs only +to electromagnetic waves for example + + align:start position:0% +to electromagnetic waves for example + + + align:start position:0% +to electromagnetic waves for example +Brewster's angle right and also the + + align:start position:0% +Brewster's angle right and also the + + + align:start position:0% +Brewster's angle right and also the +refraction mp2 refracted wave amplitude + + align:start position:0% +refraction mp2 refracted wave amplitude + + + align:start position:0% +refraction mp2 refracted wave amplitude +is actually carbon by the property of + + align:start position:0% +is actually carbon by the property of + + + align:start position:0% +is actually carbon by the property of +the electromagnetic waves which is + + align:start position:0% +the electromagnetic waves which is + + + align:start position:0% +the electromagnetic waves which is +actually coming from the laws which + + align:start position:0% +actually coming from the laws which + + + align:start position:0% +actually coming from the laws which +governs it also meant a wave which is + + align:start position:0% +governs it also meant a wave which is + + + align:start position:0% +governs it also meant a wave which is +Maxwell's equations in matter and we + + align:start position:0% +Maxwell's equations in matter and we + + + align:start position:0% +Maxwell's equations in matter and we +were trying to also manipulate lost + + align:start position:0% +were trying to also manipulate lost + + + align:start position:0% +were trying to also manipulate lost +weight by adding them together and we + + align:start position:0% +weight by adding them together and we + + + align:start position:0% +weight by adding them together and we +see constructive and destructive + + align:start position:0% +see constructive and destructive + + + align:start position:0% +see constructive and destructive +interference and diffraction phenomena + + align:start position:0% +interference and diffraction phenomena + + + align:start position:0% +interference and diffraction phenomena +and then we connect that to quantum + + align:start position:0% +and then we connect that to quantum + + + align:start position:0% +and then we connect that to quantum +mechanics by showing you a single + + align:start position:0% +mechanics by showing you a single + + + align:start position:0% +mechanics by showing you a single +electron interference experiment and + + align:start position:0% +electron interference experiment and + + + align:start position:0% +electron interference experiment and +that connects us to the beginning of the + + align:start position:0% +that connects us to the beginning of the + + + align:start position:0% +that connects us to the beginning of the +quantum mechanics which is actually + + align:start position:0% +quantum mechanics which is actually + + + align:start position:0% +quantum mechanics which is actually +public a probability waves which you + + align:start position:0% +public a probability waves which you + + + align:start position:0% +public a probability waves which you +have to be different from all the waves + + align:start position:0% +have to be different from all the waves + + + align:start position:0% +have to be different from all the waves +we have been discussing but you are + + align:start position:0% +we have been discussing but you are + + + align:start position:0% +we have been discussing but you are +going to learn a lot more in Airport + + align:start position:0% +going to learn a lot more in Airport + + + align:start position:0% +going to learn a lot more in Airport +okay so Tom don't worry + + align:start position:0% +okay so Tom don't worry + + + align:start position:0% +okay so Tom don't worry +alright so that decision to check this + + align:start position:0% +alright so that decision to check this + + + align:start position:0% +alright so that decision to check this +you can see that I can write it in two + + align:start position:0% +you can see that I can write it in two + + + align:start position:0% +you can see that I can write it in two +patches so it's not a bad already + + align:start position:0% +patches so it's not a bad already + + + align:start position:0% +patches so it's not a bad already +and I hope that there were nothing + + align:start position:0% +and I hope that there were nothing + + + align:start position:0% +and I hope that there were nothing +really sounds like new to you by now + + align:start position:0% +really sounds like new to you by now + + + align:start position:0% +really sounds like new to you by now +right + + align:start position:0% +right + + + align:start position:0% +right +if you find anything is new you have to + + align:start position:0% +if you find anything is new you have to + + + align:start position:0% +if you find anything is new you have to +review that part that means you're mr. + + align:start position:0% +review that part that means you're mr. + + + align:start position:0% +review that part that means you're mr. +Cass all right so what I'm going to do + + align:start position:0% +Cass all right so what I'm going to do + + + align:start position:0% +Cass all right so what I'm going to do +now is to go through all the material + + align:start position:0% +now is to go through all the material + + + align:start position:0% +now is to go through all the material +faster than the speed of light all right + + align:start position:0% +faster than the speed of light all right + + + align:start position:0% +faster than the speed of light all right +so that you will get nothing no you are + + align:start position:0% +so that you will get nothing no you are + + + align:start position:0% +so that you will get nothing no you are +going to get a list of the topic and you + + align:start position:0% +going to get a list of the topic and you + + + align:start position:0% +going to get a list of the topic and you +just have to feel it if you feel good + + align:start position:0% +just have to feel it if you feel good + + + align:start position:0% +just have to feel it if you feel good +like when you are having a cupcake right + + align:start position:0% +like when you are having a cupcake right + + + align:start position:0% +like when you are having a cupcake right +then you are good for the pie now if you + + align:start position:0% +then you are good for the pie now if you + + + align:start position:0% +then you are good for the pie now if you +don't feel good + + align:start position:0% +don't feel good + + + align:start position:0% +don't feel good +what is Professor D talking about he's + + align:start position:0% +what is Professor D talking about he's + + + align:start position:0% +what is Professor D talking about he's +talking about nonsense now then you are + + align:start position:0% +talking about nonsense now then you are + + + align:start position:0% +talking about nonsense now then you are +in trouble and you have to review that + + align:start position:0% +in trouble and you have to review that + + + align:start position:0% +in trouble and you have to review that +part all right + + align:start position:0% +part all right + + + align:start position:0% +part all right +okay so that's it ladoo up so that start + + align:start position:0% +okay so that's it ladoo up so that start + + + align:start position:0% +okay so that's it ladoo up so that start +all right so why a or three so we + + align:start position:0% +all right so why a or three so we + + + align:start position:0% +all right so why a or three so we +started a discussion welcome we started + + align:start position:0% +started a discussion welcome we started + + + align:start position:0% +started a discussion welcome we started +a discussion of a Austrey and it's way + + align:start position:0% +a discussion of a Austrey and it's way + + + align:start position:0% +a discussion of a Austrey and it's way +vibrational wave so it's an end of this + + align:start position:0% +vibrational wave so it's an end of this + + + align:start position:0% +vibrational wave so it's an end of this +ao3 + + align:start position:0% +ao3 + + + align:start position:0% +ao3 +and the that the motivation is really + + align:start position:0% +and the that the motivation is really + + + align:start position:0% +and the that the motivation is really +simple because we cannot even recognize + + align:start position:0% +simple because we cannot even recognize + + + align:start position:0% +simple because we cannot even recognize +the universe without using waves and + + align:start position:0% +the universe without using waves and + + + align:start position:0% +the universe without using waves and +vibration right then you cannot see me + + align:start position:0% +vibration right then you cannot see me + + + align:start position:0% +vibration right then you cannot see me +and you cannot hear anything and you + + align:start position:0% +and you cannot hear anything and you + + + align:start position:0% +and you cannot hear anything and you +cannot feel the vibration so the + + align:start position:0% +cannot feel the vibration so the + + + align:start position:0% +cannot feel the vibration so the +rotation of a black hole by your body + + align:start position:0% +rotation of a black hole by your body + + + align:start position:0% +rotation of a black hole by your body +anymore then it's not very cool right so + + align:start position:0% +anymore then it's not very cool right so + + + align:start position:0% +anymore then it's not very cool right so +therefore we as you study a o32 + + align:start position:0% +therefore we as you study a o32 + + + align:start position:0% +therefore we as you study a o32 +understand the basic ideas about waves + + align:start position:0% +understand the basic ideas about waves + + + align:start position:0% +understand the basic ideas about waves +and vibrations and we found that wave + + align:start position:0% +and vibrations and we found that wave + + + align:start position:0% +and vibrations and we found that wave +and vibrations are actually interesting + + align:start position:0% +and vibrations are actually interesting + + + align:start position:0% +and vibrations are actually interesting +phenomena waves are actually connected + + align:start position:0% +phenomena waves are actually connected + + + align:start position:0% +phenomena waves are actually connected +to vibration because if you look at only + + align:start position:0% +to vibration because if you look at only + + + align:start position:0% +to vibration because if you look at only +as for example a single object on these + + align:start position:0% +as for example a single object on these + + + align:start position:0% +as for example a single object on these +waves you will see you actually see that + + align:start position:0% +waves you will see you actually see that + + + align:start position:0% +waves you will see you actually see that +is actually a single object which is a + + align:start position:0% +is actually a single object which is a + + + align:start position:0% +is actually a single object which is a +sturdy up up and down oscillating up and + + align:start position:0% +sturdy up up and down oscillating up and + + + align:start position:0% +sturdy up up and down oscillating up and +down and this is your vibration so there + + align:start position:0% +down and this is your vibration so there + + + align:start position:0% +down and this is your vibration so there +is a close connection between single + + align:start position:0% +is a close connection between single + + + align:start position:0% +is a close connection between single +particle vibration and the waves and + + align:start position:0% +particle vibration and the waves and + + + align:start position:0% +particle vibration and the waves and +that is actually the first thing we as + + align:start position:0% +that is actually the first thing we as + + + align:start position:0% +that is actually the first thing we as +you learn therefore we need to first + + align:start position:0% +you learn therefore we need to first + + + align:start position:0% +you learn therefore we need to first +understand that you do + + align:start position:0% +understand that you do + + + align:start position:0% +understand that you do +of a single particle system and we use + + align:start position:0% +of a single particle system and we use + + + align:start position:0% +of a single particle system and we use +make use of this opportunity to actually + + align:start position:0% +make use of this opportunity to actually + + + align:start position:0% +make use of this opportunity to actually +start the discussion of scientific + + align:start position:0% +start the discussion of scientific + + + align:start position:0% +start the discussion of scientific +master right so using this opportunity + + align:start position:0% +master right so using this opportunity + + + align:start position:0% +master right so using this opportunity +basically what we have been doing for + + align:start position:0% +basically what we have been doing for + + + align:start position:0% +basically what we have been doing for +the whole class is the following so the + + align:start position:0% +the whole class is the following so the + + + align:start position:0% +the whole class is the following so the +first step is always to translate a + + align:start position:0% +first step is always to translate a + + + align:start position:0% +first step is always to translate a +physical situation which we are + + align:start position:0% +physical situation which we are + + + align:start position:0% +physical situation which we are +interested in to mathematics right + + align:start position:0% +interested in to mathematics right + + + align:start position:0% +interested in to mathematics right +because mathematics is the only language + + align:start position:0% +because mathematics is the only language + + + align:start position:0% +because mathematics is the only language +which we know which describe the nature + + align:start position:0% +which we know which describe the nature + + + align:start position:0% +which we know which describe the nature +if you come out with a new language and + + align:start position:0% +if you come out with a new language and + + + align:start position:0% +if you come out with a new language and +that is going to be super duper + + align:start position:0% +that is going to be super duper + + + align:start position:0% +that is going to be super duper +breakthrough + + align:start position:0% +breakthrough + + + align:start position:0% +breakthrough +it cannot be estimated by Nobel Prize + + align:start position:0% +it cannot be estimated by Nobel Prize + + + align:start position:0% +it cannot be estimated by Nobel Prize +but there the problem we are facing now + + align:start position:0% +but there the problem we are facing now + + + align:start position:0% +but there the problem we are facing now +is that this is the only language we + + align:start position:0% +is that this is the only language we + + + align:start position:0% +is that this is the only language we +know which works + + align:start position:0% +know which works + + + align:start position:0% +know which works +therefore we actually really follow this + + align:start position:0% +therefore we actually really follow this + + + align:start position:0% +therefore we actually really follow this +recipe for which is actually similar to + + align:start position:0% +recipe for which is actually similar to + + + align:start position:0% +recipe for which is actually similar to +many many other physics class and we + + align:start position:0% +many many other physics class and we + + + align:start position:0% +many many other physics class and we +have a physical situation we use laws of + + align:start position:0% +have a physical situation we use laws of + + + align:start position:0% +have a physical situation we use laws of +nature or models and we have a + + align:start position:0% +nature or models and we have a + + + align:start position:0% +nature or models and we have a +mathematical description which is the + + align:start position:0% +mathematical description which is the + + + align:start position:0% +mathematical description which is the +equation of motion and this is actually + + align:start position:0% +equation of motion and this is actually + + + align:start position:0% +equation of motion and this is actually +the hardest part because you need to + + align:start position:0% +the hardest part because you need to + + + align:start position:0% +the hardest part because you need to +first define a coordinate system so that + + align:start position:0% +first define a coordinate system so that + + + align:start position:0% +first define a coordinate system so that +we can express everything in a system in + + align:start position:0% +we can express everything in a system in + + + align:start position:0% +we can express everything in a system in +that system then you can actually make + + align:start position:0% +that system then you can actually make + + + align:start position:0% +that system then you can actually make +use of the physical law you have learned + + align:start position:0% +use of the physical law you have learned + + + align:start position:0% +use of the physical law you have learned +from the previous l1 and l2 to write + + align:start position:0% +from the previous l1 and l2 to write + + + align:start position:0% +from the previous l1 and l2 to write +down the equation of motion and most of + + align:start position:0% +down the equation of motion and most of + + + align:start position:0% +down the equation of motion and most of +the mistake and also most of the + + align:start position:0% +the mistake and also most of the + + + align:start position:0% +the mistake and also most of the +department or difficulty you are facing + + align:start position:0% +department or difficulty you are facing + + + align:start position:0% +department or difficulty you are facing +is always in this step actually then we + + align:start position:0% +is always in this step actually then we + + + align:start position:0% +is always in this step actually then we +can actually solve the equation of + + align:start position:0% +can actually solve the equation of + + + align:start position:0% +can actually solve the equation of +motion which is actually strictly + + align:start position:0% +motion which is actually strictly + + + align:start position:0% +motion which is actually strictly +speaking on my problem is the math + + align:start position:0% +speaking on my problem is the math + + + align:start position:0% +speaking on my problem is the math +department problem ok and yeah that's + + align:start position:0% +department problem ok and yeah that's + + + align:start position:0% +department problem ok and yeah that's +their problem anyway then we solve the + + align:start position:0% +their problem anyway then we solve the + + + align:start position:0% +their problem anyway then we solve the +equation of motion and you will keep it + + align:start position:0% +equation of motion and you will keep it + + + align:start position:0% +equation of motion and you will keep it +even the formula then we use initial + + align:start position:0% +even the formula then we use initial + + + align:start position:0% +even the formula then we use initial +conditions and the main protection and + + align:start position:0% +conditions and the main protection and + + + align:start position:0% +conditions and the main protection and +we would like to compare that to + + align:start position:0% +we would like to compare that to + + + align:start position:0% +we would like to compare that to +experimental result and that is actually + + align:start position:0% +experimental result and that is actually + + + align:start position:0% +experimental result and that is actually +the general thing which we have been + + align:start position:0% +the general thing which we have been + + + align:start position:0% +the general thing which we have been +doing for physics so that's I should + + align:start position:0% +doing for physics so that's I should + + + align:start position:0% +doing for physics so that's I should +take a look at + + align:start position:0% +take a look at + + + align:start position:0% +take a look at +those examples those are examples of + + align:start position:0% +those examples those are examples of + + + align:start position:0% +those examples those are examples of +simple harmonic motions and you can see + + align:start position:0% +simple harmonic motions and you can see + + + align:start position:0% +simple harmonic motions and you can see +that this older system have one object + + align:start position:0% +that this older system have one object + + + align:start position:0% +that this older system have one object +which is actually oscillating and you + + align:start position:0% +which is actually oscillating and you + + + align:start position:0% +which is actually oscillating and you +can see that actually their equation of + + align:start position:0% +can see that actually their equation of + + + align:start position:0% +can see that actually their equation of +motion really similar to each other is + + align:start position:0% +motion really similar to each other is + + + align:start position:0% +motion really similar to each other is +Theta double dot plus Omega zero squared + + align:start position:0% +Theta double dot plus Omega zero squared + + + align:start position:0% +Theta double dot plus Omega zero squared +theta equal to zero for those idealized + + align:start position:0% +theta equal to zero for those idealized + + + align:start position:0% +theta equal to zero for those idealized +simple harmonic motion and we actually + + align:start position:0% +simple harmonic motion and we actually + + + align:start position:0% +simple harmonic motion and we actually +learned that the solution of those + + align:start position:0% +learned that the solution of those + + + align:start position:0% +learned that the solution of those +equations actually the same which is a + + align:start position:0% + + + + align:start position:0% + +cosine function then we actually went + + align:start position:0% +cosine function then we actually went + + + align:start position:0% +cosine function then we actually went +ahead and add more craziness to the to + + align:start position:0% +ahead and add more craziness to the to + + + align:start position:0% +ahead and add more craziness to the to +the system so basically what we actually + + align:start position:0% +the system so basically what we actually + + + align:start position:0% +the system so basically what we actually +tried to do is to add a drag force I + + align:start position:0% +tried to do is to add a drag force I + + + align:start position:0% +tried to do is to add a drag force I +into the again and we were wondering if + + align:start position:0% +into the again and we were wondering if + + + align:start position:0% +into the again and we were wondering if +this more realistic description can + + align:start position:0% +this more realistic description can + + + align:start position:0% +this more realistic description can +actually match with experimental data + + align:start position:0% +actually match with experimental data + + + align:start position:0% +actually match with experimental data +all right so this is actually the + + align:start position:0% +all right so this is actually the + + + align:start position:0% +all right so this is actually the +equation of motion and the additional + + align:start position:0% +equation of motion and the additional + + + align:start position:0% +equation of motion and the additional +turn this edge with the one in the + + align:start position:0% +turn this edge with the one in the + + + align:start position:0% +turn this edge with the one in the +middle gamma C dot dot turn and after + + align:start position:0% +middle gamma C dot dot turn and after + + + align:start position:0% +middle gamma C dot dot turn and after +adding this turn not only it is real + + align:start position:0% +adding this turn not only it is real + + + align:start position:0% +adding this turn not only it is real +interesting model to describe the the + + align:start position:0% +interesting model to describe the the + + + align:start position:0% +interesting model to describe the the +physical system we are talking about but + + align:start position:0% +physical system we are talking about but + + + align:start position:0% +physical system we are talking about but +the mathematical solution is far much + + align:start position:0% +the mathematical solution is far much + + + align:start position:0% +the mathematical solution is far much +more richer than what we should talk + + align:start position:0% +more richer than what we should talk + + + align:start position:0% +more richer than what we should talk +about in the single harmonic oscillator + + align:start position:0% +about in the single harmonic oscillator + + + align:start position:0% +about in the single harmonic oscillator +case basically you will see that the + + align:start position:0% +case basically you will see that the + + + align:start position:0% +case basically you will see that the +general solution depends on the size of + + align:start position:0% +general solution depends on the size of + + + align:start position:0% +general solution depends on the size of +the gamma + + align:start position:0% +the gamma + + + align:start position:0% +the gamma +compared to Omega 0 which is the + + align:start position:0% +compared to Omega 0 which is the + + + align:start position:0% +compared to Omega 0 which is the +oscillation the natural frequency of the + + align:start position:0% +oscillation the natural frequency of the + + + align:start position:0% +oscillation the natural frequency of the +system ok and you can see there are + + align:start position:0% +system ok and you can see there are + + + align:start position:0% +system ok and you can see there are +three distinct different kinds of + + align:start position:0% +three distinct different kinds of + + + align:start position:0% +three distinct different kinds of +solution they have different + + align:start position:0% +solution they have different + + + align:start position:0% +solution they have different +mathematical form and we call them under + + align:start position:0% +mathematical form and we call them under + + + align:start position:0% +mathematical form and we call them under +temperature solution critically damped + + align:start position:0% +temperature solution critically damped + + + align:start position:0% +temperature solution critically damped +as a solution and over time the solution + + align:start position:0% +as a solution and over time the solution + + + align:start position:0% +as a solution and over time the solution +okay so those equation will be given to + + align:start position:0% +okay so those equation will be given to + + + align:start position:0% +okay so those equation will be given to +you and the excitement is the following + + align:start position:0% +you and the excitement is the following + + + align:start position:0% +you and the excitement is the following +so you can see that those solution if + + align:start position:0% +so you can see that those solution if + + + align:start position:0% +so you can see that those solution if +you plot the solution + + align:start position:0% +you plot the solution + + + align:start position:0% +you plot the solution +on time they looks completely different + + align:start position:0% +on time they looks completely different + + + align:start position:0% +on time they looks completely different +as a punctual time right so so in the + + align:start position:0% +as a punctual time right so so in the + + + align:start position:0% +as a punctual time right so so in the +case of no tempting the amplitudes issue + + align:start position:0% +case of no tempting the amplitudes issue + + + align:start position:0% +case of no tempting the amplitudes issue +the constant is not actually reducing as + + align:start position:0% +the constant is not actually reducing as + + + align:start position:0% +the constant is not actually reducing as +a function of time and but when the + + align:start position:0% +a function of time and but when the + + + align:start position:0% +a function of time and but when the +tempter system is should the temp is a + + align:start position:0% +tempter system is should the temp is a + + + align:start position:0% +tempter system is should the temp is a +turned on then in the under Templar + + align:start position:0% +turned on then in the under Templar + + + align:start position:0% +turned on then in the under Templar +situation you can see that the amplitude + + align:start position:0% +situation you can see that the amplitude + + + align:start position:0% +situation you can see that the amplitude +is reducing as a punctual time and if + + align:start position:0% +is reducing as a punctual time and if + + + align:start position:0% +is reducing as a punctual time and if +you have too much damping you put how + + align:start position:0% +you have too much damping you put how + + + align:start position:0% +you have too much damping you put how +oscillator into something qui for + + align:start position:0% +oscillator into something qui for + + + align:start position:0% +oscillator into something qui for +example and you see that the oscillation + + align:start position:0% +example and you see that the oscillation + + + align:start position:0% +example and you see that the oscillation +actually disappear right the cool thing + + align:start position:0% +actually disappear right the cool thing + + + align:start position:0% +actually disappear right the cool thing +is the following the excitement from as + + align:start position:0% +is the following the excitement from as + + + align:start position:0% +is the following the excitement from as +a physicist at all those crazy + + align:start position:0% +a physicist at all those crazy + + + align:start position:0% +a physicist at all those crazy +mathematical solution as to the match + + align:start position:0% +mathematical solution as to the match + + + align:start position:0% +mathematical solution as to the match +with experimental result wow that is + + align:start position:0% +with experimental result wow that is + + + align:start position:0% +with experimental result wow that is +really cool night because there is no + + align:start position:0% +really cool night because there is no + + + align:start position:0% +really cool night because there is no +nobody say that this should match and + + align:start position:0% +nobody say that this should match and + + + align:start position:0% +nobody say that this should match and +and how naturally should learn that okay + + align:start position:0% +and how naturally should learn that okay + + + align:start position:0% +and how naturally should learn that okay +when should I should change the behavior + + align:start position:0% +when should I should change the behavior + + + align:start position:0% +when should I should change the behavior +of the system right so this is actually + + align:start position:0% +of the system right so this is actually + + + align:start position:0% +of the system right so this is actually +really a miracle that the this + + align:start position:0% +really a miracle that the this + + + align:start position:0% +really a miracle that the this +complicated mathematical description + + align:start position:0% +complicated mathematical description + + + align:start position:0% +complicated mathematical description +actually is useful and is assessory + + align:start position:0% +actually is useful and is assessory + + + align:start position:0% +actually is useful and is assessory +super useful to describe the natural + + align:start position:0% +super useful to describe the natural + + + align:start position:0% +super useful to describe the natural +okay so once we actually have learned + + align:start position:0% +okay so once we actually have learned + + + align:start position:0% +okay so once we actually have learned +that we can now add a driving force in + + align:start position:0% +that we can now add a driving force in + + + align:start position:0% +that we can now add a driving force in +tool again okay so from the equation + + align:start position:0% +tool again okay so from the equation + + + align:start position:0% +tool again okay so from the equation +here we can see that there's a natural + + align:start position:0% +here we can see that there's a natural + + + align:start position:0% +here we can see that there's a natural +frequency Omega zero of this system and + + align:start position:0% +frequency Omega zero of this system and + + + align:start position:0% +frequency Omega zero of this system and +there is a track for strand which is + + align:start position:0% +there is a track for strand which is + + + align:start position:0% +there is a track for strand which is +actually to quantify how much track we + + align:start position:0% +actually to quantify how much track we + + + align:start position:0% +actually to quantify how much track we +have we have a comma there okay and we + + align:start position:0% +have we have a comma there okay and we + + + align:start position:0% +have we have a comma there okay and we +are driving it at a driving frequency + + align:start position:0% +are driving it at a driving frequency + + + align:start position:0% +are driving it at a driving frequency +Omega T so what we have learned from + + align:start position:0% +Omega T so what we have learned from + + + align:start position:0% +Omega T so what we have learned from +here is that if you are driving this + + align:start position:0% +here is that if you are driving this + + + align:start position:0% +here is that if you are driving this +cistern for example and shaking the + + align:start position:0% +cistern for example and shaking the + + + align:start position:0% +cistern for example and shaking the +student shaking you okay in the + + align:start position:0% +student shaking you okay in the + + + align:start position:0% +student shaking you okay in the +beginning this student is going to + + align:start position:0% +beginning this student is going to + + + align:start position:0% +beginning this student is going to +resist no don't shake me come on right + + align:start position:0% +resist no don't shake me come on right + + + align:start position:0% +resist no don't shake me come on right +but at some point he knows that + + align:start position:0% +but at some point he knows that + + + align:start position:0% +but at some point he knows that +Professor D is ready to eat + + align:start position:0% +Professor D is ready to eat + + + align:start position:0% +Professor D is ready to eat +therefore he is going to be shaked at + + align:start position:0% +therefore he is going to be shaked at + + + align:start position:0% +therefore he is going to be shaked at +the frequency I like okay so that is + + align:start position:0% +the frequency I like okay so that is + + + align:start position:0% +the frequency I like okay so that is +actually what is happening here + + align:start position:0% +actually what is happening here + + + align:start position:0% +actually what is happening here +so we this is so called the transient + + align:start position:0% +so we this is so called the transient + + + align:start position:0% +so we this is so called the transient +behavior right so adding the peak in in + + align:start position:0% +behavior right so adding the peak in in + + + align:start position:0% +behavior right so adding the peak in in +the system doesn't like it right so this + + align:start position:0% +the system doesn't like it right so this + + + align:start position:0% +the system doesn't like it right so this +is I should be making use of the + + align:start position:0% +is I should be making use of the + + + align:start position:0% +is I should be making use of the +superposition principle right so you can + + align:start position:0% +superposition principle right so you can + + + align:start position:0% +superposition principle right so you can +solve that that homogeneous solution + + align:start position:0% +solve that that homogeneous solution + + + align:start position:0% +solve that that homogeneous solution +which is I should be in the right hand + + align:start position:0% +which is I should be in the right hand + + + align:start position:0% +which is I should be in the right hand +side it depends on the physical + + align:start position:0% +side it depends on the physical + + + align:start position:0% +side it depends on the physical +situation you are talking about you + + align:start position:0% +situation you are talking about you + + + align:start position:0% +situation you are talking about you +choose the corresponding homogeneous + + align:start position:0% +choose the corresponding homogeneous + + + align:start position:0% +choose the corresponding homogeneous +solution and lapland psy is actually the + + align:start position:0% +solution and lapland psy is actually the + + + align:start position:0% +solution and lapland psy is actually the +driving force from G&G right and that is + + align:start position:0% +driving force from G&G right and that is + + + align:start position:0% +driving force from G&G right and that is +actually going to win at the end of the + + align:start position:0% +actually going to win at the end of the + + + align:start position:0% +actually going to win at the end of the +experiment right because I'm going to + + align:start position:0% +experiment right because I'm going to + + + align:start position:0% +experiment right because I'm going to +shake it forever until the end of the + + align:start position:0% +shake it forever until the end of the + + + align:start position:0% +shake it forever until the end of the +universe right so so you can see that at + + align:start position:0% +universe right so so you can see that at + + + align:start position:0% +universe right so so you can see that at +the end you what is actually lap over is + + align:start position:0% +the end you what is actually lap over is + + + align:start position:0% +the end you what is actually lap over is +really the steady-state solution and he + + align:start position:0% +really the steady-state solution and he + + + align:start position:0% +really the steady-state solution and he +has this structure a Omega D depends on + + align:start position:0% +has this structure a Omega D depends on + + + align:start position:0% +has this structure a Omega D depends on +Omega and you get restless behavior + + align:start position:0% +Omega and you get restless behavior + + + align:start position:0% +Omega and you get restless behavior +don't forget to review that and also you + + align:start position:0% +don't forget to review that and also you + + + align:start position:0% +don't forget to review that and also you +have delayed in face because when I + + align:start position:0% +have delayed in face because when I + + + align:start position:0% +have delayed in face because when I +shake the student the student needs some + + align:start position:0% +shake the student the student needs some + + + align:start position:0% +shake the student the student needs some +time to respond right therefore the + + align:start position:0% +time to respond right therefore the + + + align:start position:0% +time to respond right therefore the +theta is actually nonzero if the student + + align:start position:0% +theta is actually nonzero if the student + + + align:start position:0% +theta is actually nonzero if the student +is damped okay all right so now we have + + align:start position:0% +is damped okay all right so now we have + + + align:start position:0% +is damped okay all right so now we have +learned all the secrets about a single + + align:start position:0% +learned all the secrets about a single + + + align:start position:0% +learned all the secrets about a single +object system then we can now go ahead + + align:start position:0% +object system then we can now go ahead + + + align:start position:0% +object system then we can now go ahead +and study coupled oscillators there are + + align:start position:0% +and study coupled oscillators there are + + + align:start position:0% +and study coupled oscillators there are +a few examples here which is coupled + + align:start position:0% +a few examples here which is coupled + + + align:start position:0% +a few examples here which is coupled +upon to dance or Cobo the stream + + align:start position:0% +upon to dance or Cobo the stream + + + align:start position:0% +upon to dance or Cobo the stream +assistance and we found that a very + + align:start position:0% +assistance and we found that a very + + + align:start position:0% +assistance and we found that a very +useful description of this kind of + + align:start position:0% +useful description of this kind of + + + align:start position:0% +useful description of this kind of +system is to make use of the magic + + align:start position:0% +system is to make use of the magic + + + align:start position:0% +system is to make use of the magic +language okay so originally if you have + + align:start position:0% +language okay so originally if you have + + + align:start position:0% +language okay so originally if you have +n objects in the system you have n + + align:start position:0% +n objects in the system you have n + + + align:start position:0% +n objects in the system you have n +equations of motions and that looks + + align:start position:0% +equations of motions and that looks + + + align:start position:0% +equations of motions and that looks +horrible right but what is actually done + + align:start position:0% +horrible right but what is actually done + + + align:start position:0% +horrible right but what is actually done +in our series that we actually + + align:start position:0% +in our series that we actually + + + align:start position:0% +in our series that we actually +introduced + + align:start position:0% + + + + align:start position:0% + +the notation with metrics basically if + + align:start position:0% +the notation with metrics basically if + + + align:start position:0% +the notation with metrics basically if +you write everything in terms of metrics + + align:start position:0% +you write everything in terms of metrics + + + align:start position:0% +you write everything in terms of metrics +then it looks really friendly right and + + align:start position:0% +then it looks really friendly right and + + + align:start position:0% +then it looks really friendly right and +it looks really like a single oscillator + + align:start position:0% +it looks really like a single oscillator + + + align:start position:0% +it looks really like a single oscillator +right okay + + align:start position:0% +right okay + + + align:start position:0% +right okay +although solving this this equation is + + align:start position:0% +although solving this this equation is + + + align:start position:0% +although solving this this equation is +still a little bit more work okay and + + align:start position:0% +still a little bit more work okay and + + + align:start position:0% +still a little bit more work okay and +basically you can see that from this + + align:start position:0% +basically you can see that from this + + + align:start position:0% +basically you can see that from this +example we can actually write M minus 1 + + align:start position:0% +example we can actually write M minus 1 + + + align:start position:0% +example we can actually write M minus 1 +K matrix and the whole equation movie + + align:start position:0% +K matrix and the whole equation movie + + + align:start position:0% +K matrix and the whole equation movie +which equation of motion problem solving + + align:start position:0% +which equation of motion problem solving + + + align:start position:0% +which equation of motion problem solving +problem become M as 1 K matrix + + align:start position:0% +problem become M as 1 K matrix + + + align:start position:0% +problem become M as 1 K matrix +eigenvalue problem what is actually M is + + align:start position:0% +eigenvalue problem what is actually M is + + + align:start position:0% +eigenvalue problem what is actually M is +1 make K matrix ok this is as with + + align:start position:0% +1 make K matrix ok this is as with + + + align:start position:0% +1 make K matrix ok this is as with +describing how each component in the + + align:start position:0% +describing how each component in the + + + align:start position:0% +describing how each component in the +system should interact with each other + + align:start position:0% +system should interact with each other + + + align:start position:0% +system should interact with each other +right so once we have this we can + + align:start position:0% +right so once we have this we can + + + align:start position:0% +right so once we have this we can +actually solve the eigenvalue problem + + align:start position:0% +actually solve the eigenvalue problem + + + align:start position:0% +actually solve the eigenvalue problem +and we are going to be able to figure + + align:start position:0% +and we are going to be able to figure + + + align:start position:0% +and we are going to be able to figure +out the normal modes of those system so + + align:start position:0% +out the normal modes of those system so + + + align:start position:0% +out the normal modes of those system so +what is actually normal mode normal mode + + align:start position:0% +what is actually normal mode normal mode + + + align:start position:0% +what is actually normal mode normal mode +is a situation where all the components + + align:start position:0% +is a situation where all the components + + + align:start position:0% +is a situation where all the components +in the system are oscillating at the + + align:start position:0% +in the system are oscillating at the + + + align:start position:0% +in the system are oscillating at the +same frequency and the also at the same + + align:start position:0% +same frequency and the also at the same + + + align:start position:0% +same frequency and the also at the same +phase okay so that is actually the + + align:start position:0% +phase okay so that is actually the + + + align:start position:0% +phase okay so that is actually the +definition of normal mode and also + + align:start position:0% +definition of normal mode and also + + + align:start position:0% +definition of normal mode and also +actually what is actually used in debris + + align:start position:0% +actually what is actually used in debris + + + align:start position:0% +actually what is actually used in debris +ation also which leads us to the + + align:start position:0% +ation also which leads us to the + + + align:start position:0% +ation also which leads us to the +eigenvalue problem we define Z equal to + + align:start position:0% +eigenvalue problem we define Z equal to + + + align:start position:0% +eigenvalue problem we define Z equal to +exponential I Omega T plus Phi everybody + + align:start position:0% +exponential I Omega T plus Phi everybody + + + align:start position:0% +exponential I Omega T plus Phi everybody +is resonating at Omega and also a phase + + align:start position:0% +is resonating at Omega and also a phase + + + align:start position:0% +is resonating at Omega and also a phase +Phi right so that is actually what we + + align:start position:0% +Phi right so that is actually what we + + + align:start position:0% +Phi right so that is actually what we +actually learned and what is actually + + align:start position:0% +actually learned and what is actually + + + align:start position:0% +actually learned and what is actually +the physical meaning of the those normal + + align:start position:0% +the physical meaning of the those normal + + + align:start position:0% +the physical meaning of the those normal +modes so if we plot the locus of the two + + align:start position:0% +modes so if we plot the locus of the two + + + align:start position:0% +modes so if we plot the locus of the two +coupled pendulum partment what we + + align:start position:0% +coupled pendulum partment what we + + + align:start position:0% +coupled pendulum partment what we +actually see is the following so + + align:start position:0% +actually see is the following so + + + align:start position:0% +actually see is the following so +basically you will see that the locust + + align:start position:0% +basically you will see that the locust + + + align:start position:0% +basically you will see that the locust +looks like do the complicated as a + + align:start position:0% +looks like do the complicated as a + + + align:start position:0% +looks like do the complicated as a +function of time if you plot XY x 2 + + align:start position:0% +function of time if you plot XY x 2 + + + align:start position:0% +function of time if you plot XY x 2 +versus time but if we rotate this system + + align:start position:0% +versus time but if we rotate this system + + + align:start position:0% +versus time but if we rotate this system +a bit then we find that this is a really + + align:start position:0% +a bit then we find that this is a really + + + align:start position:0% +a bit then we find that this is a really +interesting projection which is the + + align:start position:0% +interesting projection which is the + + + align:start position:0% +interesting projection which is the +principal cordon + + align:start position:0% +principal cordon + + + align:start position:0% +principal cordon +we see that actually all those crazy + + align:start position:0% +we see that actually all those crazy + + + align:start position:0% +we see that actually all those crazy +strange phenomena we see with carpet + + align:start position:0% +strange phenomena we see with carpet + + + align:start position:0% +strange phenomena we see with carpet +assistants are just illusions actually + + align:start position:0% +assistants are just illusions actually + + + align:start position:0% +assistants are just illusions actually +you can understand them by really using + + align:start position:0% +you can understand them by really using + + + align:start position:0% +you can understand them by really using +the right projection okay - one well - + + align:start position:0% +the right projection okay - one well - + + + align:start position:0% +the right projection okay - one well - +to the right coordinate system then you + + align:start position:0% +to the right coordinate system then you + + + align:start position:0% +to the right coordinate system then you +will see that HD decision is - in still + + align:start position:0% +will see that HD decision is - in still + + + align:start position:0% +will see that HD decision is - in still +simple harmonic motion okay so that is + + align:start position:0% +simple harmonic motion okay so that is + + + align:start position:0% +simple harmonic motion okay so that is +actually the cool thing which we learn + + align:start position:0% +actually the cool thing which we learn + + + align:start position:0% +actually the cool thing which we learn +from a coupled system so we learned + + align:start position:0% +from a coupled system so we learned + + + align:start position:0% +from a coupled system so we learned +about how to resolve the cop of the + + align:start position:0% +about how to resolve the cop of the + + + align:start position:0% +about how to resolve the cop of the +system and we also learned about going + + align:start position:0% +system and we also learned about going + + + align:start position:0% +system and we also learned about going +to infinite number of coupled system ok + + align:start position:0% +to infinite number of coupled system ok + + + align:start position:0% +to infinite number of coupled system ok +so then this is an example here so for + + align:start position:0% +so then this is an example here so for + + + align:start position:0% +so then this is an example here so for +example I can hear Pentagon and Springs + + align:start position:0% +example I can hear Pentagon and Springs + + + align:start position:0% +example I can hear Pentagon and Springs +and we connect them all together and and + + align:start position:0% +and we connect them all together and and + + + align:start position:0% +and we connect them all together and and +I need to hire many many students so + + align:start position:0% +I need to hire many many students so + + + align:start position:0% +I need to hire many many students so +that they praise it or the prayers until + + align:start position:0% +that they praise it or the prayers until + + + align:start position:0% +that they praise it or the prayers until +you know few up the whole universe right + + align:start position:0% +you know few up the whole universe right + + + align:start position:0% +you know few up the whole universe right +so this is actually the idea of infini + + align:start position:0% +so this is actually the idea of infini + + + align:start position:0% +so this is actually the idea of infini +system okay and you can see that that + + align:start position:0% +system okay and you can see that that + + + align:start position:0% +system okay and you can see that that +means my n minus 1 K matrix going to be + + align:start position:0% +means my n minus 1 K matrix going to be + + + align:start position:0% +means my n minus 1 K matrix going to be +infinite as infinitely long matrix okay + + align:start position:0% +infinite as infinitely long matrix okay + + + align:start position:0% +infinite as infinitely long matrix okay +it's two dimensional and the a is + + align:start position:0% +it's two dimensional and the a is + + + align:start position:0% +it's two dimensional and the a is +infinitely long and that sounds really + + align:start position:0% +infinitely long and that sounds really + + + align:start position:0% +infinitely long and that sounds really +scary and in general we don't know how + + align:start position:0% +scary and in general we don't know how + + + align:start position:0% +scary and in general we don't know how +to deal with this okay and it can be + + align:start position:0% +to deal with this okay and it can be + + + align:start position:0% +to deal with this okay and it can be +arbitrarily crazy as you can imagine + + align:start position:0% +arbitrarily crazy as you can imagine + + + align:start position:0% +arbitrarily crazy as you can imagine +okay so what we should discuss in a or + + align:start position:0% +okay so what we should discuss in a or + + + align:start position:0% +okay so what we should discuss in a or +three is a special case basically we are + + align:start position:0% +three is a special case basically we are + + + align:start position:0% +three is a special case basically we are +discussing about systems which are + + align:start position:0% +discussing about systems which are + + + align:start position:0% +discussing about systems which are +having a special kind of symmetry which + + align:start position:0% +having a special kind of symmetry which + + + align:start position:0% +having a special kind of symmetry which +is translation symmetry as you can see + + align:start position:0% +is translation symmetry as you can see + + + align:start position:0% +is translation symmetry as you can see +from all those figures and you can see + + align:start position:0% +from all those figures and you can see + + + align:start position:0% +from all those figures and you can see +that all those figures will have to all + + align:start position:0% +that all those figures will have to all + + + align:start position:0% +that all those figures will have to all +have the same normal modes right because + + align:start position:0% +have the same normal modes right because + + + align:start position:0% +have the same normal modes right because +of the space translation symmetry what + + align:start position:0% +of the space translation symmetry what + + + align:start position:0% +of the space translation symmetry what +we actually discussed above is that we + + align:start position:0% +we actually discussed above is that we + + + align:start position:0% +we actually discussed above is that we +introduced + + align:start position:0% +introduced + + + align:start position:0% +introduced +as matrix which essentially used to + + align:start position:0% +as matrix which essentially used to + + + align:start position:0% +as matrix which essentially used to +describe the kind of symmetry that this + + align:start position:0% +describe the kind of symmetry that this + + + align:start position:0% +describe the kind of symmetry that this +system is should satisfy right and we if + + align:start position:0% +system is should satisfy right and we if + + + align:start position:0% +system is should satisfy right and we if +we if we calculate a communicator + + align:start position:0% +we if we calculate a communicator + + + align:start position:0% +we if we calculate a communicator +s and M is quite a matrix if their + + align:start position:0% +s and M is quite a matrix if their + + + align:start position:0% +s and M is quite a matrix if their +company this communicator shows that if + + align:start position:0% +company this communicator shows that if + + + align:start position:0% +company this communicator shows that if +you evaluate this communicator and you + + align:start position:0% +you evaluate this communicator and you + + + align:start position:0% +you evaluate this communicator and you +get 0 that means they commute and that + + align:start position:0% +get 0 that means they commute and that + + + align:start position:0% +get 0 that means they commute and that +the consequence is that the S matrix and + + align:start position:0% +the consequence is that the S matrix and + + + align:start position:0% +the consequence is that the S matrix and +SMI 1 K matrix will share the same + + align:start position:0% +SMI 1 K matrix will share the same + + + align:start position:0% +SMI 1 K matrix will share the same +eigenvectors + + align:start position:0% +eigenvectors + + + align:start position:0% +eigenvectors +ok so you don't really need to know how + + align:start position:0% +ok so you don't really need to know how + + + align:start position:0% +ok so you don't really need to know how +to derive this conclusion to a ripe this + + align:start position:0% +to derive this conclusion to a ripe this + + + align:start position:0% +to derive this conclusion to a ripe this +conclusion but it is actually very + + align:start position:0% +conclusion but it is actually very + + + align:start position:0% +conclusion but it is actually very +useful conclusion so that means instead + + align:start position:0% +useful conclusion so that means instead + + + align:start position:0% +useful conclusion so that means instead +of solving and minus 1 K matrix eigen + + align:start position:0% +of solving and minus 1 K matrix eigen + + + align:start position:0% +of solving and minus 1 K matrix eigen +value problem I can now go ahead to + + align:start position:0% +value problem I can now go ahead to + + + align:start position:0% +value problem I can now go ahead to +solve the S matrix eigen value problem + + align:start position:0% +solve the S matrix eigen value problem + + + align:start position:0% +solve the S matrix eigen value problem +and you ready that's much easier okay so + + align:start position:0% +and you ready that's much easier okay so + + + align:start position:0% +and you ready that's much easier okay so +for the exam you need to know how to + + align:start position:0% +for the exam you need to know how to + + + align:start position:0% +for the exam you need to know how to +write down as matrix you need to know + + align:start position:0% +write down as matrix you need to know + + + align:start position:0% +write down as matrix you need to know +how to solve icon value problems + + align:start position:0% +how to solve icon value problems + + + align:start position:0% +how to solve icon value problems +including image why make a matrix and + + align:start position:0% +including image why make a matrix and + + + align:start position:0% +including image why make a matrix and +the S matrix and then we can actually + + align:start position:0% +the S matrix and then we can actually + + + align:start position:0% +the S matrix and then we can actually +get to normal mode frequency Omega + + align:start position:0% +get to normal mode frequency Omega + + + align:start position:0% +get to normal mode frequency Omega +Square and we can also solve the + + align:start position:0% +Square and we can also solve the + + + align:start position:0% +Square and we can also solve the +corresponding normal mode and here is + + align:start position:0% +corresponding normal mode and here is + + + align:start position:0% +corresponding normal mode and here is +actually telling you what will be the + + align:start position:0% +actually telling you what will be the + + + align:start position:0% +actually telling you what will be the +solution for the space translation + + align:start position:0% +solution for the space translation + + + align:start position:0% +solution for the space translation +symmetric system and basically what you + + align:start position:0% +symmetric system and basically what you + + + align:start position:0% +symmetric system and basically what you +see is that making use of s matrix + + align:start position:0% +see is that making use of s matrix + + + align:start position:0% +see is that making use of s matrix +actually prints you look to a conclusion + + align:start position:0% +actually prints you look to a conclusion + + + align:start position:0% +actually prints you look to a conclusion +AJ must be a proportional to exponential + + align:start position:0% +AJ must be a proportional to exponential + + + align:start position:0% +AJ must be a proportional to exponential +IJ K a where this a is actually the + + align:start position:0% +IJ K a where this a is actually the + + + align:start position:0% +IJ K a where this a is actually the +length scale of this system the this + + align:start position:0% +length scale of this system the this + + + align:start position:0% +length scale of this system the this +distance between all those little mass + + align:start position:0% +distance between all those little mass + + + align:start position:0% +distance between all those little mass +and J is actually a label which tells + + align:start position:0% +and J is actually a label which tells + + + align:start position:0% +and J is actually a label which tells +you which little mess I'm talking about + + align:start position:0% +you which little mess I'm talking about + + + align:start position:0% +you which little mess I'm talking about +and K is actually some arbitrary + + align:start position:0% +and K is actually some arbitrary + + + align:start position:0% +and K is actually some arbitrary +constant when by now you should have the + + align:start position:0% +constant when by now you should have the + + + align:start position:0% +constant when by now you should have the +idea basically that's that's what the + + align:start position:0% +idea basically that's that's what the + + + align:start position:0% +idea basically that's that's what the +hardest is the wave number + + align:start position:0% +hardest is the wave number + + + align:start position:0% +hardest is the wave number +so that is really cool so that's also oh + + align:start position:0% +so that is really cool so that's also oh + + + align:start position:0% +so that is really cool so that's also oh +I shoulda print you know the bands and + + align:start position:0% +I shoulda print you know the bands and + + + align:start position:0% +I shoulda print you know the bands and +basically you can see that we can also + + align:start position:0% +basically you can see that we can also + + + align:start position:0% +basically you can see that we can also +write down the a K because we know that + + align:start position:0% +write down the a K because we know that + + + align:start position:0% +write down the a K because we know that +H a would be proportional to exponential + + align:start position:0% +H a would be proportional to exponential + + + align:start position:0% +H a would be proportional to exponential +I Chi ka after solving the eigenvalue + + align:start position:0% +I Chi ka after solving the eigenvalue + + + align:start position:0% +I Chi ka after solving the eigenvalue +problem for as matrix then we actually + + align:start position:0% +problem for as matrix then we actually + + + align:start position:0% +problem for as matrix then we actually +went one step forward to make it + + align:start position:0% +went one step forward to make it + + + align:start position:0% +went one step forward to make it +continuous right so basically we we make + + align:start position:0% +continuous right so basically we we make + + + align:start position:0% +continuous right so basically we we make +the space between particles very very + + align:start position:0% +the space between particles very very + + + align:start position:0% +the space between particles very very +small and also at the same time we make + + align:start position:0% +small and also at the same time we make + + + align:start position:0% +small and also at the same time we make +sure that the string doesn't become + + align:start position:0% +sure that the string doesn't become + + + align:start position:0% +sure that the string doesn't become +super massive right + + align:start position:0% +super massive right + + + align:start position:0% +super massive right +and we actually concluded that we get + + align:start position:0% +and we actually concluded that we get + + + align:start position:0% +and we actually concluded that we get +some kind of equation popping out from + + align:start position:0% +some kind of equation popping out from + + + align:start position:0% +some kind of equation popping out from +this exercise and minus 1 k matrix + + align:start position:0% +this exercise and minus 1 k matrix + + + align:start position:0% +this exercise and minus 1 k matrix +become minus T over Rho L partial square + + align:start position:0% +become minus T over Rho L partial square + + + align:start position:0% +become minus T over Rho L partial square +partial k x squared you don't have to + + align:start position:0% +partial k x squared you don't have to + + + align:start position:0% +partial k x squared you don't have to +really derive this for the exam but you + + align:start position:0% +really derive this for the exam but you + + + align:start position:0% +really derive this for the exam but you +need to know the conclusion and the five + + align:start position:0% +need to know the conclusion and the five + + + align:start position:0% +need to know the conclusion and the five +sides they become sigh so punctual x and + + align:start position:0% +sides they become sigh so punctual x and + + + align:start position:0% +sides they become sigh so punctual x and +t and the magical function is you + + align:start position:0% +t and the magical function is you + + + align:start position:0% +t and the magical function is you +appeared which is the wave equation oh + + align:start position:0% +appeared which is the wave equation oh + + + align:start position:0% +appeared which is the wave equation oh +my god this is the whole craziness we + + align:start position:0% +my god this is the whole craziness we + + + align:start position:0% +my god this is the whole craziness we +have been dealing with hole a or three + + align:start position:0% +have been dealing with hole a or three + + + align:start position:0% +have been dealing with hole a or three +right then this is actually really + + align:start position:0% +right then this is actually really + + + align:start position:0% +right then this is actually really +remarkable that we actually can come + + align:start position:0% +remarkable that we actually can come + + + align:start position:0% +remarkable that we actually can come +from single up to a solution putting it + + align:start position:0% +from single up to a solution putting it + + + align:start position:0% +from single up to a solution putting it +all together make it continues the + + align:start position:0% +all together make it continues the + + + align:start position:0% +all together make it continues the +endless equation really pop out and this + + align:start position:0% +endless equation really pop out and this + + + align:start position:0% +endless equation really pop out and this +equation should really describe multiple + + align:start position:0% +equation should really describe multiple + + + align:start position:0% +equation should really describe multiple +systems then we went ahead to actually + + align:start position:0% +systems then we went ahead to actually + + + align:start position:0% +systems then we went ahead to actually +discuss the property of the wave + + align:start position:0% +discuss the property of the wave + + + align:start position:0% +discuss the property of the wave +equation it looks like this they say the + + align:start position:0% +equation it looks like this they say the + + + align:start position:0% +equation it looks like this they say the +I replace the P over Rho L by V P Square + + align:start position:0% +I replace the P over Rho L by V P Square + + + align:start position:0% +I replace the P over Rho L by V P Square +by now you know the meaning will be P is + + align:start position:0% +by now you know the meaning will be P is + + + align:start position:0% +by now you know the meaning will be P is +actually the phase velocity and we + + align:start position:0% +actually the phase velocity and we + + + align:start position:0% +actually the phase velocity and we +discussed two kinds of solutions a + + align:start position:0% +discussed two kinds of solutions a + + + align:start position:0% +discussed two kinds of solutions a +special kind of solution the first kind + + align:start position:0% +special kind of solution the first kind + + + align:start position:0% +special kind of solution the first kind +is normal mode the second one is + + align:start position:0% +is normal mode the second one is + + + align:start position:0% +is normal mode the second one is +progressive wave solution or traveling + + align:start position:0% +progressive wave solution or traveling + + + align:start position:0% +progressive wave solution or traveling +wave solution whatever name you want + + align:start position:0% +wave solution whatever name you want + + + align:start position:0% +wave solution whatever name you want +coin the state should take a look at the + + align:start position:0% +coin the state should take a look at the + + + align:start position:0% +coin the state should take a look at the +normal modes what we have have we + + align:start position:0% +normal modes what we have have we + + + align:start position:0% +normal modes what we have have we +learned so if you have a bond system in + + align:start position:0% +learned so if you have a bond system in + + + align:start position:0% +learned so if you have a bond system in +pound continuous system the normal mode + + align:start position:0% +pound continuous system the normal mode + + + align:start position:0% +pound continuous system the normal mode +is actually standing waves for the wave + + align:start position:0% +is actually standing waves for the wave + + + align:start position:0% +is actually standing waves for the wave +equation we discussed and basically the + + align:start position:0% +equation we discussed and basically the + + + align:start position:0% +equation we discussed and basically the +functional form is a and saying okay and + + align:start position:0% +functional form is a and saying okay and + + + align:start position:0% +functional form is a and saying okay and +X plus alpha m and sine Omega M T plus + + align:start position:0% +X plus alpha m and sine Omega M T plus + + + align:start position:0% +X plus alpha m and sine Omega M T plus +beta m okay so what we actually learned + + align:start position:0% +beta m okay so what we actually learned + + + align:start position:0% +beta m okay so what we actually learned +from from the previous lecture is the + + align:start position:0% +from from the previous lecture is the + + + align:start position:0% +from from the previous lecture is the +following so basically you can actually + + align:start position:0% +following so basically you can actually + + + align:start position:0% +following so basically you can actually +decide the km and Appa and by boundary + + align:start position:0% +decide the km and Appa and by boundary + + + align:start position:0% +decide the km and Appa and by boundary +conditions right so before you introduce + + align:start position:0% +conditions right so before you introduce + + + align:start position:0% +conditions right so before you introduce +boundary conditions which are the + + align:start position:0% +boundary conditions which are the + + + align:start position:0% +boundary conditions which are the +conditions allow you to describe + + align:start position:0% +conditions allow you to describe + + + align:start position:0% +conditions allow you to describe +multiple nearby system consistently okay + + align:start position:0% +multiple nearby system consistently okay + + + align:start position:0% +multiple nearby system consistently okay +so that is actually the meaning of + + align:start position:0% +so that is actually the meaning of + + + align:start position:0% +so that is actually the meaning of +boundary condition before you introduce + + align:start position:0% +boundary condition before you introduce + + + align:start position:0% +boundary condition before you introduce +that KN and alpha n a Puteri number + + align:start position:0% +that KN and alpha n a Puteri number + + + align:start position:0% +that KN and alpha n a Puteri number +whatever number you can you choose + + align:start position:0% +whatever number you can you choose + + + align:start position:0% +whatever number you can you choose +easily can satisfy the wave equation but + + align:start position:0% +easily can satisfy the wave equation but + + + align:start position:0% +easily can satisfy the wave equation but +after you actually introduce the + + align:start position:0% +after you actually introduce the + + + align:start position:0% +after you actually introduce the +boundary condition you figure that out + + align:start position:0% +boundary condition you figure that out + + + align:start position:0% +boundary condition you figure that out +from the front from a problem you are + + align:start position:0% +from the front from a problem you are + + + align:start position:0% +from the front from a problem you are +given then K N and alpha n cannot be + + align:start position:0% +given then K N and alpha n cannot be + + + align:start position:0% +given then K N and alpha n cannot be +arbitrary anymore and they usually pick + + align:start position:0% +arbitrary anymore and they usually pick + + + align:start position:0% +arbitrary anymore and they usually pick +on discrete numbers okay so that is + + align:start position:0% +on discrete numbers okay so that is + + + align:start position:0% +on discrete numbers okay so that is +actually what we actually learned from + + align:start position:0% +actually what we actually learned from + + + align:start position:0% +actually what we actually learned from +the previous lectures and the finally we + + align:start position:0% +the previous lectures and the finally we + + + align:start position:0% +the previous lectures and the finally we +will also see that on Omega n is + + align:start position:0% +will also see that on Omega n is + + + align:start position:0% +will also see that on Omega n is +actually determined by the property of + + align:start position:0% +actually determined by the property of + + + align:start position:0% +actually determined by the property of +the system by so called dispersion + + align:start position:0% +the system by so called dispersion + + + align:start position:0% +the system by so called dispersion +relation in this case is linear is + + align:start position:0% +relation in this case is linear is + + + align:start position:0% +relation in this case is linear is +proportional to K n because we are + + align:start position:0% +proportional to K n because we are + + + align:start position:0% +proportional to K n because we are +talking about assets per step median for + + align:start position:0% +talking about assets per step median for + + + align:start position:0% +talking about assets per step median for +the moment and we have this beta n which + + align:start position:0% +the moment and we have this beta n which + + + align:start position:0% +the moment and we have this beta n which +is actually related to the initial + + align:start position:0% +is actually related to the initial + + + align:start position:0% +is actually related to the initial +condition and a.m. which can actually be + + align:start position:0% +condition and a.m. which can actually be + + + align:start position:0% +condition and a.m. which can actually be +determined by food year decomposition + + align:start position:0% +determined by food year decomposition + + + align:start position:0% +determined by food year decomposition +right so if you are not familiar with + + align:start position:0% +right so if you are not familiar with + + + align:start position:0% +right so if you are not familiar with +this you have to really review how to do + + align:start position:0% +this you have to really review how to do + + + align:start position:0% +this you have to really review how to do +food their decomposition okay I know + + align:start position:0% +food their decomposition okay I know + + + align:start position:0% +food their decomposition okay I know +most of you + + align:start position:0% +most of you + + + align:start position:0% +most of you +we did very well in the meter but maybe + + align:start position:0% +we did very well in the meter but maybe + + + align:start position:0% +we did very well in the meter but maybe +some of you actually forgot how to + + align:start position:0% +some of you actually forgot how to + + + align:start position:0% +some of you actually forgot how to +actually determine a.m. and it would be + + align:start position:0% +actually determine a.m. and it would be + + + align:start position:0% +actually determine a.m. and it would be +very very important to rebuild that for + + align:start position:0% +very very important to rebuild that for + + + align:start position:0% +very very important to rebuild that for +the preparation for the final now the + + align:start position:0% +the preparation for the final now the + + + align:start position:0% +the preparation for the final now the +second set of solution in Safari so you + + align:start position:0% +second set of solution in Safari so you + + + align:start position:0% +second set of solution in Safari so you +have progress progressing waves and the + + align:start position:0% +have progress progressing waves and the + + + align:start position:0% +have progress progressing waves and the +functional form is really interesting so + + align:start position:0% +functional form is really interesting so + + + align:start position:0% +functional form is really interesting so +you can see it's actually can be written + + align:start position:0% +you can see it's actually can be written + + + align:start position:0% +you can see it's actually can be written +as f f is an arbitrary function x + - v + + align:start position:0% +as f f is an arbitrary function x + - v + + + align:start position:0% +as f f is an arbitrary function x + - v +PT type a CD that is as you described in + + align:start position:0% +PT type a CD that is as you described in + + + align:start position:0% +PT type a CD that is as you described in +a wave which is traveling to the + + align:start position:0% +a wave which is traveling to the + + + align:start position:0% +a wave which is traveling to the +positive to a negative or positive + + align:start position:0% +positive to a negative or positive + + + align:start position:0% +positive to a negative or positive +direction in the X direction and or you + + align:start position:0% +direction in the X direction and or you + + + align:start position:0% +direction in the X direction and or you +can easily write it down as G function + + align:start position:0% +can easily write it down as G function + + + align:start position:0% +can easily write it down as G function +KX plus minus Omega T actually they + + align:start position:0% +KX plus minus Omega T actually they + + + align:start position:0% +KX plus minus Omega T actually they +actually all works for wave equations + + align:start position:0% +actually all works for wave equations + + + align:start position:0% +actually all works for wave equations +now we actually went ahead and and apply + + align:start position:0% +now we actually went ahead and and apply + + + align:start position:0% +now we actually went ahead and and apply +the approach which we learn from the the + + align:start position:0% +the approach which we learn from the the + + + align:start position:0% +the approach which we learn from the the +general solution of web equation two + + align:start position:0% +general solution of web equation two + + + align:start position:0% +general solution of web equation two +massive strings and we discussed about + + align:start position:0% +massive strings and we discussed about + + + align:start position:0% +massive strings and we discussed about +some waves right for the Sun waves it + + align:start position:0% +some waves right for the Sun waves it + + + align:start position:0% +some waves right for the Sun waves it +will be important to actually review + + align:start position:0% +will be important to actually review + + + align:start position:0% +will be important to actually review +what are the boundary conditions for the + + align:start position:0% +what are the boundary conditions for the + + + align:start position:0% +what are the boundary conditions for the +displacement of the of the molecule in + + align:start position:0% +displacement of the of the molecule in + + + align:start position:0% +displacement of the of the molecule in +the in the Sun wave compared to the + + align:start position:0% +the in the Sun wave compared to the + + + align:start position:0% +the in the Sun wave compared to the +pressure deviation from the run pressure + + align:start position:0% +pressure deviation from the run pressure + + + align:start position:0% +pressure deviation from the run pressure +okay so I think it's important to make + + align:start position:0% +okay so I think it's important to make + + + align:start position:0% +okay so I think it's important to make +sure that you understand the difference + + align:start position:0% +sure that you understand the difference + + + align:start position:0% +sure that you understand the difference +between these two what are the boundary + + align:start position:0% +between these two what are the boundary + + + align:start position:0% +between these two what are the boundary +conditions and and basically issue + + align:start position:0% +conditions and and basically issue + + + align:start position:0% +conditions and and basically issue +actually be very similar to the solution + + align:start position:0% +actually be very similar to the solution + + + align:start position:0% +actually be very similar to the solution +the boundary condition for the massive + + align:start position:0% +the boundary condition for the massive + + + align:start position:0% +the boundary condition for the massive +high strings and we also talked about + + align:start position:0% +high strings and we also talked about + + + align:start position:0% +high strings and we also talked about +electromagnetic waves right and that is + + align:start position:0% +electromagnetic waves right and that is + + + align:start position:0% +electromagnetic waves right and that is +actually another topic which you really + + align:start position:0% +actually another topic which you really + + + align:start position:0% +actually another topic which you really +have to review and several things which + + align:start position:0% +have to review and several things which + + + align:start position:0% +have to review and several things which +is actually interesting is that electric + + align:start position:0% +is actually interesting is that electric + + + align:start position:0% +is actually interesting is that electric +field cannot dip with our magnetic field + + align:start position:0% +field cannot dip with our magnetic field + + + align:start position:0% +field cannot dip with our magnetic field +right they are always together no matter + + align:start position:0% +right they are always together no matter + + + align:start position:0% +right they are always together no matter +what right so if you have a traveling + + align:start position:0% +what right so if you have a traveling + + + align:start position:0% +what right so if you have a traveling +electric field the + + align:start position:0% +electric field the + + + align:start position:0% +electric field the +there must be a chair boarding magnetic + + align:start position:0% +there must be a chair boarding magnetic + + + align:start position:0% +there must be a chair boarding magnetic +field and that is actually governed by + + align:start position:0% +field and that is actually governed by + + + align:start position:0% +field and that is actually governed by +the Maxwell's equation because before we + + align:start position:0% +the Maxwell's equation because before we + + + align:start position:0% +the Maxwell's equation because before we +actually go into the detail of those we + + align:start position:0% +actually go into the detail of those we + + + align:start position:0% +actually go into the detail of those we +also discussed about dispersive medium + + align:start position:0% +also discussed about dispersive medium + + + align:start position:0% +also discussed about dispersive medium +right so in the case of dispersive + + align:start position:0% +right so in the case of dispersive + + + align:start position:0% +right so in the case of dispersive +medium we actually use the special kind + + align:start position:0% +medium we actually use the special kind + + + align:start position:0% +medium we actually use the special kind +of example which is strings with + + align:start position:0% +of example which is strings with + + + align:start position:0% +of example which is strings with +stiffness right so basically what we + + align:start position:0% +stiffness right so basically what we + + + align:start position:0% +stiffness right so basically what we +actually found is that if you have a + + align:start position:0% +actually found is that if you have a + + + align:start position:0% +actually found is that if you have a +certain kinds of wave equation like like + + align:start position:0% +certain kinds of wave equation like like + + + align:start position:0% +certain kinds of wave equation like like +this one yeah I know I should writing + + align:start position:0% +this one yeah I know I should writing + + + align:start position:0% +this one yeah I know I should writing +this one here basically if I add + + align:start position:0% +this one here basically if I add + + + align:start position:0% +this one here basically if I add +additional tend to describe the + + align:start position:0% +additional tend to describe the + + + align:start position:0% +additional tend to describe the +stiffness right then what is actually + + align:start position:0% +stiffness right then what is actually + + + align:start position:0% +stiffness right then what is actually +going to happen is that the dispersion + + align:start position:0% +going to happen is that the dispersion + + + align:start position:0% +going to happen is that the dispersion +relation when I ask you to approach the + + align:start position:0% +relation when I ask you to approach the + + + align:start position:0% +relation when I ask you to approach the +dispersion relation usually and + + align:start position:0% +dispersion relation usually and + + + align:start position:0% +dispersion relation usually and +requesting you to find the relation + + align:start position:0% +requesting you to find the relation + + + align:start position:0% +requesting you to find the relation +between Omega and the K and I'm going + + align:start position:0% +between Omega and the K and I'm going + + + align:start position:0% +between Omega and the K and I'm going +over this in more detail because I see + + align:start position:0% +over this in more detail because I see + + + align:start position:0% +over this in more detail because I see +so many similar mistakes in the mid ton + + align:start position:0% +so many similar mistakes in the mid ton + + + align:start position:0% +so many similar mistakes in the mid ton +so basically what I am asking is Omega + + align:start position:0% +so basically what I am asking is Omega + + + align:start position:0% +so basically what I am asking is Omega +versus K and in the if we don't have + + align:start position:0% +versus K and in the if we don't have + + + align:start position:0% +versus K and in the if we don't have +this turn then basically you have a + + align:start position:0% +this turn then basically you have a + + + align:start position:0% +this turn then basically you have a +straight line straight line means you + + align:start position:0% +straight line straight line means you + + + align:start position:0% +straight line straight line means you +have a non dispersive medium right and + + align:start position:0% +have a non dispersive medium right and + + + align:start position:0% +have a non dispersive medium right and +if you add this turn you need to know + + align:start position:0% +if you add this turn you need to know + + + align:start position:0% +if you add this turn you need to know +how to evaluate the dispersion relation + + align:start position:0% +how to evaluate the dispersion relation + + + align:start position:0% +how to evaluate the dispersion relation +the quickest way to evaluate the + + align:start position:0% +the quickest way to evaluate the + + + align:start position:0% +the quickest way to evaluate the +dispersion relation is to just simply + + align:start position:0% +dispersion relation is to just simply + + + align:start position:0% +dispersion relation is to just simply +plug in the progressing wave solution + + align:start position:0% +plug in the progressing wave solution + + + align:start position:0% +plug in the progressing wave solution +for them for the G function or harmonic + + align:start position:0% +for them for the G function or harmonic + + + align:start position:0% +for them for the G function or harmonic +focusing wave resolution sine Omega KX + + align:start position:0% +focusing wave resolution sine Omega KX + + + align:start position:0% +focusing wave resolution sine Omega KX +plus minus Omega T into this equation + + align:start position:0% +plus minus Omega T into this equation + + + align:start position:0% +plus minus Omega T into this equation +then you will be able to figure out the + + align:start position:0% +then you will be able to figure out the + + + align:start position:0% +then you will be able to figure out the +dispersion relation and what we actually + + align:start position:0% +dispersion relation and what we actually + + + align:start position:0% +dispersion relation and what we actually +figure out is the following if we + + align:start position:0% +figure out is the following if we + + + align:start position:0% +figure out is the following if we +actually include stiffness then you can + + align:start position:0% +actually include stiffness then you can + + + align:start position:0% +actually include stiffness then you can +see that the dispersion relation is not + + align:start position:0% +see that the dispersion relation is not + + + align:start position:0% +see that the dispersion relation is not +a lie + + align:start position:0% +a lie + + + align:start position:0% +a lie +anymore and the accession essentially + + align:start position:0% +anymore and the accession essentially + + + align:start position:0% +anymore and the accession essentially +some kind of curve and the slope is + + align:start position:0% +some kind of curve and the slope is + + + align:start position:0% +some kind of curve and the slope is +actually changing okay + + align:start position:0% +actually changing okay + + + align:start position:0% +actually changing okay +and there are dramatic or consequence + + align:start position:0% +and there are dramatic or consequence + + + align:start position:0% +and there are dramatic or consequence +from this thing right that means if I + + align:start position:0% +from this thing right that means if I + + + align:start position:0% +from this thing right that means if I +have a troubling wave okay with + + align:start position:0% +have a troubling wave okay with + + + align:start position:0% +have a troubling wave okay with +different wavelengths that means the + + align:start position:0% +different wavelengths that means the + + + align:start position:0% +different wavelengths that means the +phase velocity VP equal to Omega over K + + align:start position:0% +phase velocity VP equal to Omega over K + + + align:start position:0% +phase velocity VP equal to Omega over K +is going to be different for different + + align:start position:0% +is going to be different for different + + + align:start position:0% +is going to be different for different +for waves with different frequency or + + align:start position:0% +for waves with different frequency or + + + align:start position:0% +for waves with different frequency or +different wavelengths okay so that is + + align:start position:0% +different wavelengths okay so that is + + + align:start position:0% +different wavelengths okay so that is +actually clearly a problem because if I + + align:start position:0% +actually clearly a problem because if I + + + align:start position:0% +actually clearly a problem because if I +have initially produce a signal which is + + align:start position:0% +have initially produce a signal which is + + + align:start position:0% +have initially produce a signal which is +triangle and I'd like the proper gay + + align:start position:0% +triangle and I'd like the proper gay + + + align:start position:0% +triangle and I'd like the proper gay +what is going to happen is that the slow + + align:start position:0% +what is going to happen is that the slow + + + align:start position:0% +what is going to happen is that the slow +component will be lagged behind those + + align:start position:0% +component will be lagged behind those + + + align:start position:0% +component will be lagged behind those +are the slow component and the first + + align:start position:0% +are the slow component and the first + + + align:start position:0% +are the slow component and the first +component will go ahead of the nominal + + align:start position:0% +component will go ahead of the nominal + + + align:start position:0% +component will go ahead of the nominal +speed right so there will be a spread of + + align:start position:0% +speed right so there will be a spread of + + + align:start position:0% +speed right so there will be a spread of +the signal or judge originally maybe you + + align:start position:0% +the signal or judge originally maybe you + + + align:start position:0% +the signal or judge originally maybe you +have some kind of a square wave and this + + align:start position:0% +have some kind of a square wave and this + + + align:start position:0% +have some kind of a square wave and this +thing will become something which is + + align:start position:0% +thing will become something which is + + + align:start position:0% +thing will become something which is +actually along which it is smeared out + + align:start position:0% +actually along which it is smeared out + + + align:start position:0% +actually along which it is smeared out +in space and you deuce the the + + align:start position:0% +in space and you deuce the the + + + align:start position:0% +in space and you deuce the the +information and that we are going to + + align:start position:0% +information and that we are going to + + + align:start position:0% +information and that we are going to +talk about that later and we also + + align:start position:0% +talk about that later and we also + + + align:start position:0% +talk about that later and we also +learned about group velocity so what is + + align:start position:0% +learned about group velocity so what is + + + align:start position:0% +learned about group velocity so what is +a group velocity group velocity VP vbg + + align:start position:0% +a group velocity group velocity VP vbg + + + align:start position:0% +a group velocity group velocity VP vbg +essentially partial Omega hydrocal right + + align:start position:0% +essentially partial Omega hydrocal right + + + align:start position:0% +essentially partial Omega hydrocal right +which is actually the slope of + + align:start position:0% +which is actually the slope of + + + align:start position:0% +which is actually the slope of +tangential line here and well the phase + + align:start position:0% +tangential line here and well the phase + + + align:start position:0% +tangential line here and well the phase +velocity is actually connecting this + + align:start position:0% +velocity is actually connecting this + + + align:start position:0% +velocity is actually connecting this +point to that point and the slope of + + align:start position:0% +point to that point and the slope of + + + align:start position:0% +point to that point and the slope of +this this line is actually the phase + + align:start position:0% +this this line is actually the phase + + + align:start position:0% +this this line is actually the phase +phase velocity and the slope of the line + + align:start position:0% +phase velocity and the slope of the line + + + align:start position:0% +phase velocity and the slope of the line +cutting through this point which is + + align:start position:0% +cutting through this point which is + + + align:start position:0% +cutting through this point which is +actually giving you the group velocity + + align:start position:0% +actually giving you the group velocity + + + align:start position:0% +actually giving you the group velocity +and we actually learn the definition of + + align:start position:0% +and we actually learn the definition of + + + align:start position:0% +and we actually learn the definition of +the consequence + + align:start position:0% +the consequence + + + align:start position:0% +the consequence +of group velocity and phase velocity by + + align:start position:0% +of group velocity and phase velocity by + + + align:start position:0% +of group velocity and phase velocity by +introducing you a bit phenomena + + align:start position:0% +introducing you a bit phenomena + + + align:start position:0% +introducing you a bit phenomena +basically we add two waves with similar + + align:start position:0% +basically we add two waves with similar + + + align:start position:0% +basically we add two waves with similar +with wavelength or wave number basically + + align:start position:0% +with wavelength or wave number basically + + + align:start position:0% +with wavelength or wave number basically +what we see is the power in so basically + + align:start position:0% +what we see is the power in so basically + + + align:start position:0% +what we see is the power in so basically +you see some behavior like this we see + + align:start position:0% +you see some behavior like this we see + + + align:start position:0% +you see some behavior like this we see +this this superposition of these two + + align:start position:0% +this this superposition of these two + + + align:start position:0% +this this superposition of these two +waves which produce a bit phenomena can + + align:start position:0% +waves which produce a bit phenomena can + + + align:start position:0% +waves which produce a bit phenomena can +be understood by some synchronization + + align:start position:0% +be understood by some synchronization + + + align:start position:0% +be understood by some synchronization +oscillating really fast modulated by + + align:start position:0% +oscillating really fast modulated by + + + align:start position:0% +oscillating really fast modulated by +much slowed or mareting envelope + + align:start position:0% +much slowed or mareting envelope + + + align:start position:0% +much slowed or mareting envelope +basically you can actually understand + + align:start position:0% +basically you can actually understand + + + align:start position:0% +basically you can actually understand +the pit phenomena by decomposing to by + + align:start position:0% +the pit phenomena by decomposing to by + + + align:start position:0% +the pit phenomena by decomposing to by +actually identifying these two + + align:start position:0% +actually identifying these two + + + align:start position:0% +actually identifying these two +interesting structure and the speed of + + align:start position:0% +interesting structure and the speed of + + + align:start position:0% +interesting structure and the speed of +odd all those little Peaks is actually + + align:start position:0% +odd all those little Peaks is actually + + + align:start position:0% +odd all those little Peaks is actually +traveling at phase velocity and the + + align:start position:0% +traveling at phase velocity and the + + + align:start position:0% +traveling at phase velocity and the +speed of the envelope is actually found + + align:start position:0% +speed of the envelope is actually found + + + align:start position:0% +speed of the envelope is actually found +to be traveling at group velocity okay + + align:start position:0% +to be traveling at group velocity okay + + + align:start position:0% +to be traveling at group velocity okay +so that is actually what we have learned + + align:start position:0% +so that is actually what we have learned + + + align:start position:0% +so that is actually what we have learned +and we can have group velocity and the + + align:start position:0% +and we can have group velocity and the + + + align:start position:0% +and we can have group velocity and the +phase velocity troubling at the same + + align:start position:0% +phase velocity troubling at the same + + + align:start position:0% +phase velocity troubling at the same +direction and we can also have negative + + align:start position:0% +direction and we can also have negative + + + align:start position:0% +direction and we can also have negative +group velocity right so that is a + + align:start position:0% +group velocity right so that is a + + + align:start position:0% +group velocity right so that is a +technique which is really really very + + align:start position:0% +technique which is really really very + + + align:start position:0% +technique which is really really very +difficult and then still trying to + + align:start position:0% +difficult and then still trying to + + + align:start position:0% +difficult and then still trying to +practice and make sure that I can't a + + align:start position:0% +practice and make sure that I can't a + + + align:start position:0% +practice and make sure that I can't a +model in three basically is like the + + align:start position:0% +model in three basically is like the + + + align:start position:0% +model in three basically is like the +whole system the whole edita structure I + + align:start position:0% +whole system the whole edita structure I + + + align:start position:0% +whole system the whole edita structure I +should be moving in a positive direction + + align:start position:0% +should be moving in a positive direction + + + align:start position:0% +should be moving in a positive direction +but the body or say the envelope is + + align:start position:0% +but the body or say the envelope is + + + align:start position:0% +but the body or say the envelope is +actually moving in the negative x + + align:start position:0% +actually moving in the negative x + + + align:start position:0% +actually moving in the negative x +direction so that is actually also + + align:start position:0% +direction so that is actually also + + + align:start position:0% +direction so that is actually also +possible and you can actually construct + + align:start position:0% +possible and you can actually construct + + + align:start position:0% +possible and you can actually construct +a system which you have negative group + + align:start position:0% +a system which you have negative group + + + align:start position:0% +a system which you have negative group +asset so once we have done that we + + align:start position:0% +asset so once we have done that we + + + align:start position:0% +asset so once we have done that we +actually also try to understand further + + align:start position:0% +actually also try to understand further + + + align:start position:0% +actually also try to understand further +the description of the solution for the + + align:start position:0% +the description of the solution for the + + + align:start position:0% +the description of the solution for the +discrete dispersive + + align:start position:0% +discrete dispersive + + + align:start position:0% +discrete dispersive +right so basically what we actually went + + align:start position:0% +right so basically what we actually went + + + align:start position:0% +right so basically what we actually went +over during the class is that okay now + + align:start position:0% +over during the class is that okay now + + + align:start position:0% +over during the class is that okay now +if the F function f of T is describing + + align:start position:0% +if the F function f of T is describing + + + align:start position:0% +if the F function f of T is describing +Eunji's hand and I'm holding infinitely + + align:start position:0% +Eunji's hand and I'm holding infinitely + + + align:start position:0% +Eunji's hand and I'm holding infinitely +long string and I shake it as a function + + align:start position:0% +long string and I shake it as a function + + + align:start position:0% +long string and I shake it as a function +of time and that is actually this motion + + align:start position:0% +of time and that is actually this motion + + + align:start position:0% +of time and that is actually this motion +is actually described by this F function + + align:start position:0% +is actually described by this F function + + + align:start position:0% +is actually described by this F function +okay what we actually know is that this + + align:start position:0% +okay what we actually know is that this + + + align:start position:0% +okay what we actually know is that this +this oscillation okay I can I can do + + align:start position:0% +this oscillation okay I can I can do + + + align:start position:0% +this oscillation okay I can I can do +whatever I want but the all kind of F + + align:start position:0% +whatever I want but the all kind of F + + + align:start position:0% +whatever I want but the all kind of F +function can be described a + + align:start position:0% +function can be described a + + + align:start position:0% +function can be described a +superposition of many many many waves + + align:start position:0% +superposition of many many many waves + + + align:start position:0% +superposition of many many many waves +with different angular frequency okay so + + align:start position:0% +with different angular frequency okay so + + + align:start position:0% +with different angular frequency okay so +that's a miracle which we pal row from + + align:start position:0% +that's a miracle which we pal row from + + + align:start position:0% +that's a miracle which we pal row from +the maths Department again and you can + + align:start position:0% +the maths Department again and you can + + + align:start position:0% +the maths Department again and you can +see that F function can be written as a + + align:start position:0% +see that F function can be written as a + + + align:start position:0% +see that F function can be written as a +sum of all kinds of different waves with + + align:start position:0% +sum of all kinds of different waves with + + + align:start position:0% +sum of all kinds of different waves with +different angular frequency with + + align:start position:0% +different angular frequency with + + + align:start position:0% +different angular frequency with +population see you make Omega this this + + align:start position:0% +population see you make Omega this this + + + align:start position:0% +population see you make Omega this this +is actually the weight which we make + + align:start position:0% +is actually the weight which we make + + + align:start position:0% +is actually the weight which we make +them become the F function okay and we + + align:start position:0% +them become the F function okay and we + + + align:start position:0% +them become the F function okay and we +can actually figure out the C Omega by + + align:start position:0% +can actually figure out the C Omega by + + + align:start position:0% +can actually figure out the C Omega by +doing a Fourier transform and finally + + align:start position:0% +doing a Fourier transform and finally + + + align:start position:0% +doing a Fourier transform and finally +what will be the resulting wave function + + align:start position:0% +what will be the resulting wave function + + + align:start position:0% +what will be the resulting wave function +sigh XT which is actually the wave + + align:start position:0% +sigh XT which is actually the wave + + + align:start position:0% +sigh XT which is actually the wave +function generated by the oscillation of + + align:start position:0% +function generated by the oscillation of + + + align:start position:0% +function generated by the oscillation of +my hand and also carbon by the wave + + align:start position:0% +my hand and also carbon by the wave + + + align:start position:0% +my hand and also carbon by the wave +equation which give you the relation + + align:start position:0% +equation which give you the relation + + + align:start position:0% +equation which give you the relation +between Omega and the K can be written + + align:start position:0% +between Omega and the K can be written + + + align:start position:0% +between Omega and the K can be written +in in that functional form okay so so + + align:start position:0% +in in that functional form okay so so + + + align:start position:0% +in in that functional form okay so so +the good news is that with the help of + + align:start position:0% +the good news is that with the help of + + + align:start position:0% +the good news is that with the help of +buddhir transform we can issue the also + + align:start position:0% +buddhir transform we can issue the also + + + align:start position:0% +buddhir transform we can issue the also +describe and predict what is going to + + align:start position:0% +describe and predict what is going to + + + align:start position:0% +describe and predict what is going to +happen no matter if this system is + + align:start position:0% +happen no matter if this system is + + + align:start position:0% +happen no matter if this system is +dispersive or not dispersive using this + + align:start position:0% +dispersive or not dispersive using this + + + align:start position:0% +dispersive or not dispersive using this +approach okay so that is actually really + + align:start position:0% +approach okay so that is actually really + + + align:start position:0% +approach okay so that is actually really +cool and you can of course you can do a + + align:start position:0% +cool and you can of course you can do a + + + align:start position:0% +cool and you can of course you can do a +cross-check just to assume that this + + align:start position:0% +cross-check just to assume that this + + + align:start position:0% +cross-check just to assume that this +sort is this is a non dispersive media + + align:start position:0% +sort is this is a non dispersive media + + + align:start position:0% +sort is this is a non dispersive media +and you are also going to get back to + + align:start position:0% +and you are also going to get back to + + + align:start position:0% +and you are also going to get back to +what you should expect the solution to + + align:start position:0% +what you should expect the solution to + + + align:start position:0% +what you should expect the solution to +non dispersive medium for the sigh XT so + + align:start position:0% +non dispersive medium for the sigh XT so + + + align:start position:0% +non dispersive medium for the sigh XT so +that is actually one thing which is + + align:start position:0% +that is actually one thing which is + + + align:start position:0% +that is actually one thing which is +really remarkable and you know I think + + align:start position:0% +really remarkable and you know I think + + + align:start position:0% +really remarkable and you know I think +what is actually needed to to know is + + align:start position:0% +what is actually needed to to know is + + + align:start position:0% +what is actually needed to to know is +not a deviation of Otto's formula but + + align:start position:0% +not a deviation of Otto's formula but + + + align:start position:0% +not a deviation of Otto's formula but +how to issue the practing and the + + align:start position:0% +how to issue the practing and the + + + align:start position:0% +how to issue the practing and the +derived C Omega right by using the + + align:start position:0% +derived C Omega right by using the + + + align:start position:0% +derived C Omega right by using the +formula you are given and how to + + align:start position:0% +formula you are given and how to + + + align:start position:0% +formula you are given and how to +actually then put together or the + + align:start position:0% +actually then put together or the + + + align:start position:0% +actually then put together or the +solution and the camp and the picker the + + align:start position:0% +solution and the camp and the picker the + + + align:start position:0% +solution and the camp and the picker the +resulting solution for the site XT which + + align:start position:0% +resulting solution for the site XT which + + + align:start position:0% +resulting solution for the site XT which +is actually really the solution we + + align:start position:0% +is actually really the solution we + + + align:start position:0% +is actually really the solution we +really care okay so for that you need to + + align:start position:0% +really care okay so for that you need to + + + align:start position:0% +really care okay so for that you need to +know how to do the integration you need + + align:start position:0% +know how to do the integration you need + + + align:start position:0% +know how to do the integration you need +to know how to derive the dispersion + + align:start position:0% +to know how to derive the dispersion + + + align:start position:0% +to know how to derive the dispersion +relation then what is HP lap over is to + + align:start position:0% +relation then what is HP lap over is to + + + align:start position:0% +relation then what is HP lap over is to +put them pregnant in into that equation + + align:start position:0% +put them pregnant in into that equation + + + align:start position:0% +put them pregnant in into that equation +which is actually also given to you in a + + align:start position:0% +which is actually also given to you in a + + + align:start position:0% +which is actually also given to you in a +formula and and we will not ask you to + + align:start position:0% +formula and and we will not ask you to + + + align:start position:0% +formula and and we will not ask you to +do very very complicated integration for + + align:start position:0% +do very very complicated integration for + + + align:start position:0% +do very very complicated integration for +sure in a panel so what is actually the + + align:start position:0% +sure in a panel so what is actually the + + + align:start position:0% +sure in a panel so what is actually the +consequence so basically one thing which + + align:start position:0% +consequence so basically one thing which + + + align:start position:0% +consequence so basically one thing which +is interesting to know is that if you + + align:start position:0% +is interesting to know is that if you + + + align:start position:0% +is interesting to know is that if you +have waves in a coordinate space which + + align:start position:0% +have waves in a coordinate space which + + + align:start position:0% +have waves in a coordinate space which +is really widely spread out and you can + + align:start position:0% +is really widely spread out and you can + + + align:start position:0% +is really widely spread out and you can +do Fourier transform to get the weight + + align:start position:0% +do Fourier transform to get the weight + + + align:start position:0% +do Fourier transform to get the weight +population in the frequency space when + + align:start position:0% +population in the frequency space when + + + align:start position:0% +population in the frequency space when +we find is that when when this wave is + + align:start position:0% +we find is that when when this wave is + + + align:start position:0% +we find is that when when this wave is +really really wide in the space then + + align:start position:0% +really really wide in the space then + + + align:start position:0% +really really wide in the space then +what we find is that actually the web + + align:start position:0% +what we find is that actually the web + + + align:start position:0% +what we find is that actually the web +population in the frequency space is + + align:start position:0% +population in the frequency space is + + + align:start position:0% +population in the frequency space is +very narrow okay by using Fourier + + align:start position:0% +very narrow okay by using Fourier + + + align:start position:0% +very narrow okay by using Fourier +transform the notice issue the result + + align:start position:0% +transform the notice issue the result + + + align:start position:0% +transform the notice issue the result +and on the other hand if you have a + + align:start position:0% +and on the other hand if you have a + + + align:start position:0% +and on the other hand if you have a +pretty very narrow pulse in the + + align:start position:0% +pretty very narrow pulse in the + + + align:start position:0% +pretty very narrow pulse in the +coordinate space for example I to this + + align:start position:0% +coordinate space for example I to this + + + align:start position:0% +coordinate space for example I to this +very very really quickly alright I + + align:start position:0% +very very really quickly alright I + + + align:start position:0% +very very really quickly alright I +create a very narrow pulse and what is + + align:start position:0% +create a very narrow pulse and what is + + + align:start position:0% +create a very narrow pulse and what is +actually happening is that I will have + + align:start position:0% +actually happening is that I will have + + + align:start position:0% +actually happening is that I will have +to use + + align:start position:0% +to use + + + align:start position:0% +to use +a very wide range of frequency space to + + align:start position:0% +a very wide range of frequency space to + + + align:start position:0% +a very wide range of frequency space to +describe this very narrow pulse okay so + + align:start position:0% +describe this very narrow pulse okay so + + + align:start position:0% +describe this very narrow pulse okay so +that these two direct consequences of + + align:start position:0% +that these two direct consequences of + + + align:start position:0% +that these two direct consequences of +that is uncertainty principle and this + + align:start position:0% +that is uncertainty principle and this + + + align:start position:0% +that is uncertainty principle and this +actually closely connected to the + + align:start position:0% +actually closely connected to the + + + align:start position:0% +actually closely connected to the +uncertainty principle we talked about in + + align:start position:0% +uncertainty principle we talked about in + + + align:start position:0% +uncertainty principle we talked about in +a quantum mechanics Delta P times Delta + + align:start position:0% +a quantum mechanics Delta P times Delta + + + align:start position:0% +a quantum mechanics Delta P times Delta +X greater or equal to H bar over 2 all + + align:start position:0% +X greater or equal to H bar over 2 all + + + align:start position:0% +X greater or equal to H bar over 2 all +right so we have done with the + + align:start position:0% +right so we have done with the + + + align:start position:0% +right so we have done with the +one-dimensional case and we also talked + + align:start position:0% +one-dimensional case and we also talked + + + align:start position:0% +one-dimensional case and we also talked +about a two dimensional and the three + + align:start position:0% +about a two dimensional and the three + + + align:start position:0% +about a two dimensional and the three +dimensional case and this is an example + + align:start position:0% +dimensional case and this is an example + + + align:start position:0% +dimensional case and this is an example +of two dimensional membranes and + + align:start position:0% +of two dimensional membranes and + + + align:start position:0% +of two dimensional membranes and +actually a constraint so that the + + align:start position:0% +actually a constraint so that the + + + align:start position:0% +actually a constraint so that the +boundary condition at the boundary is + + align:start position:0% +boundary condition at the boundary is + + + align:start position:0% +boundary condition at the boundary is +equal the wave function is equal to zero + + align:start position:0% +equal the wave function is equal to zero + + + align:start position:0% +equal the wave function is equal to zero +and you can easily identify all those + + align:start position:0% +and you can easily identify all those + + + align:start position:0% +and you can easily identify all those +normal modes and we went ahead also to + + align:start position:0% +normal modes and we went ahead also to + + + align:start position:0% +normal modes and we went ahead also to +talk about geometric optics lots + + align:start position:0% +talk about geometric optics lots + + + align:start position:0% +talk about geometric optics lots +basically how how do we actually write + + align:start position:0% +basically how how do we actually write + + + align:start position:0% +basically how how do we actually write +that is to have a plane wave first you + + align:start position:0% +that is to have a plane wave first you + + + align:start position:0% +that is to have a plane wave first you +have a plane wave propagating toward the + + align:start position:0% +have a plane wave propagating toward the + + + align:start position:0% +have a plane wave propagating toward the +boundary of two different median and we + + align:start position:0% +boundary of two different median and we + + + align:start position:0% +boundary of two different median and we +were wondering what is actually the + + align:start position:0% +were wondering what is actually the + + + align:start position:0% +were wondering what is actually the +refracted wave and the transmitted wave + + align:start position:0% +refracted wave and the transmitted wave + + + align:start position:0% +refracted wave and the transmitted wave +by using like two by making sure just + + align:start position:0% +by using like two by making sure just + + + align:start position:0% +by using like two by making sure just +one point which is that the membranes + + align:start position:0% +one point which is that the membranes + + + align:start position:0% +one point which is that the membranes +doesn't break okay the wave function is + + align:start position:0% +doesn't break okay the wave function is + + + align:start position:0% +doesn't break okay the wave function is +continuous at this boundary that's the + + align:start position:0% +continuous at this boundary that's the + + + align:start position:0% +continuous at this boundary that's the +only assumption which we use we went + + align:start position:0% +only assumption which we use we went + + + align:start position:0% +only assumption which we use we went +through the mathematics which we don't + + align:start position:0% +through the mathematics which we don't + + + align:start position:0% +through the mathematics which we don't +really need to to remember all of them + + align:start position:0% +really need to to remember all of them + + + align:start position:0% +really need to to remember all of them +but you really need to remember the + + align:start position:0% +but you really need to remember the + + + align:start position:0% +but you really need to remember the +consequence the consequence is the + + align:start position:0% +consequence the consequence is the + + + align:start position:0% +consequence the consequence is the +following + + align:start position:0% +following + + + align:start position:0% +following +so basically what we see is that if you + + align:start position:0% +so basically what we see is that if you + + + align:start position:0% +so basically what we see is that if you +have in certain frame wave which in + + align:start position:0% +have in certain frame wave which in + + + align:start position:0% +have in certain frame wave which in +certain angle theta-1 the refractive + + align:start position:0% +certain angle theta-1 the refractive + + + align:start position:0% +certain angle theta-1 the refractive +wave will be having an angle of theta + + align:start position:0% +wave will be having an angle of theta + + + align:start position:0% +wave will be having an angle of theta +one as well so that's actually the first + + align:start position:0% +one as well so that's actually the first + + + align:start position:0% +one as well so that's actually the first +law of refraction refraction law and the + + align:start position:0% +law of refraction refraction law and the + + + align:start position:0% +law of refraction refraction law and the +second one which we learn is that the + + align:start position:0% +second one which we learn is that the + + + align:start position:0% +second one which we learn is that the +transmitted wave where satisfies Snell's + + align:start position:0% +transmitted wave where satisfies Snell's + + + align:start position:0% +transmitted wave where satisfies Snell's +law + + align:start position:0% +law + + + align:start position:0% +law +and one sign theta 1 equal to n 2 sine + + align:start position:0% +and one sign theta 1 equal to n 2 sine + + + align:start position:0% +and one sign theta 1 equal to n 2 sine +theta 2 and that is that should be very + + align:start position:0% +theta 2 and that is that should be very + + + align:start position:0% +theta 2 and that is that should be very +interesting because this Snell's law ok + + align:start position:0% +interesting because this Snell's law ok + + + align:start position:0% +interesting because this Snell's law ok +have also nothing to do with Maxwell's + + align:start position:0% +have also nothing to do with Maxwell's + + + align:start position:0% +have also nothing to do with Maxwell's +equation you see right that's actually + + align:start position:0% +equation you see right that's actually + + + align:start position:0% +equation you see right that's actually +what you actually can learn from here it + + align:start position:0% +what you actually can learn from here it + + + align:start position:0% +what you actually can learn from here it +will usually use electromagnetic waves + + align:start position:0% +will usually use electromagnetic waves + + + align:start position:0% +will usually use electromagnetic waves +to demonstrate Snell's law right but + + align:start position:0% +to demonstrate Snell's law right but + + + align:start position:0% +to demonstrate Snell's law right but +from else we learned that it has nothing + + align:start position:0% +from else we learned that it has nothing + + + align:start position:0% +from else we learned that it has nothing +to do with in M Maxwell's equation + + align:start position:0% +to do with in M Maxwell's equation + + + align:start position:0% +to do with in M Maxwell's equation +applies to all kinds of different + + align:start position:0% +applies to all kinds of different + + + align:start position:0% +applies to all kinds of different +systems which you can which can be + + align:start position:0% +systems which you can which can be + + + align:start position:0% +systems which you can which can be +described by wave functions so that is + + align:start position:0% +described by wave functions so that is + + + align:start position:0% +described by wave functions so that is +actually the very important consequence + + align:start position:0% +actually the very important consequence + + + align:start position:0% +actually the very important consequence +but on the other hand as we already + + align:start position:0% +but on the other hand as we already + + + align:start position:0% +but on the other hand as we already +discussed later the relative amplitude + + align:start position:0% +discussed later the relative amplitude + + + align:start position:0% +discussed later the relative amplitude +of the in certain wave refractive wave + + align:start position:0% +of the in certain wave refractive wave + + + align:start position:0% +of the in certain wave refractive wave +and transmitted wave the relative + + align:start position:0% +and transmitted wave the relative + + + align:start position:0% +and transmitted wave the relative +amplitude is governed by Maxwell's + + align:start position:0% +amplitude is governed by Maxwell's + + + align:start position:0% +amplitude is governed by Maxwell's +equations so I would like to make a + + align:start position:0% +equations so I would like to make a + + + align:start position:0% +equations so I would like to make a +really crystal clear so the relative + + align:start position:0% +really crystal clear so the relative + + + align:start position:0% +really crystal clear so the relative +amplitude is governed by really the + + align:start position:0% +amplitude is governed by really the + + + align:start position:0% +amplitude is governed by really the +physical laws which actually governs the + + align:start position:0% +physical laws which actually governs the + + + align:start position:0% +physical laws which actually governs the +publication of those prime waves ok so I + + align:start position:0% +publication of those prime waves ok so I + + + align:start position:0% +publication of those prime waves ok so I +think we can actually take a five-minute + + align:start position:0% +think we can actually take a five-minute + + + align:start position:0% +think we can actually take a five-minute +break to help some some here and of + + align:start position:0% +break to help some some here and of + + + align:start position:0% +break to help some some here and of +course you can we are welcome to + + align:start position:0% +course you can we are welcome to + + + align:start position:0% +course you can we are welcome to +continue to use all those tools and the + + align:start position:0% +continue to use all those tools and the + + + align:start position:0% +continue to use all those tools and the +coffee when coming back at 38 + + align:start position:0% + + + + align:start position:0% + +okay so welcome back everybody from the + + align:start position:0% +okay so welcome back everybody from the + + + align:start position:0% +okay so welcome back everybody from the +break so yeah so we are going to + + align:start position:0% +break so yeah so we are going to + + + align:start position:0% +break so yeah so we are going to +continue the discussion so we have + + align:start position:0% +continue the discussion so we have + + + align:start position:0% +continue the discussion so we have +actually learned about the two important + + align:start position:0% +actually learned about the two important + + + align:start position:0% +actually learned about the two important +laws for the geometrical optics and we + + align:start position:0% +laws for the geometrical optics and we + + + align:start position:0% +laws for the geometrical optics and we +actually also went ahead to discuss the + + align:start position:0% +actually also went ahead to discuss the + + + align:start position:0% +actually also went ahead to discuss the +polarization itself in greater detail so + + align:start position:0% +polarization itself in greater detail so + + + align:start position:0% +polarization itself in greater detail so +for example we can have the nearly + + align:start position:0% +for example we can have the nearly + + + align:start position:0% +for example we can have the nearly +polarized wave so basically the wave + + align:start position:0% +polarized wave so basically the wave + + + align:start position:0% +polarized wave so basically the wave +sees a ship moving up and down up and + + align:start position:0% +sees a ship moving up and down up and + + + align:start position:0% +sees a ship moving up and down up and +down but the direction of the of the + + align:start position:0% +down but the direction of the of the + + + align:start position:0% +down but the direction of the of the +vector field doesn't doesn't change okay + + align:start position:0% +vector field doesn't doesn't change okay + + + align:start position:0% +vector field doesn't doesn't change okay +it's always for example initially if + + align:start position:0% +it's always for example initially if + + + align:start position:0% +it's always for example initially if +it's in X direction and he's actually at + + align:start position:0% +it's in X direction and he's actually at + + + align:start position:0% +it's in X direction and he's actually at +the X direction forever and in that case + + align:start position:0% +the X direction forever and in that case + + + align:start position:0% +the X direction forever and in that case +I call it linearly polarized okay of + + align:start position:0% +I call it linearly polarized okay of + + + align:start position:0% +I call it linearly polarized okay of +course I can also have the case that I + + align:start position:0% +course I can also have the case that I + + + align:start position:0% +course I can also have the case that I +can actually have a superposition of two + + align:start position:0% +can actually have a superposition of two + + + align:start position:0% +can actually have a superposition of two +waves one is actually having the + + align:start position:0% +waves one is actually having the + + + align:start position:0% +waves one is actually having the +electric field in the X direction and + + align:start position:0% +electric field in the X direction and + + + align:start position:0% +electric field in the X direction and +the other one is Asia in the Y direction + + align:start position:0% +the other one is Asia in the Y direction + + + align:start position:0% +the other one is Asia in the Y direction +and they are off by a face of PI over 2 + + align:start position:0% +and they are off by a face of PI over 2 + + + align:start position:0% +and they are off by a face of PI over 2 +if that happens then basically you will + + align:start position:0% +if that happens then basically you will + + + align:start position:0% +if that happens then basically you will +see that you produce something really + + align:start position:0% +see that you produce something really + + + align:start position:0% +see that you produce something really +interesting the direction of the + + align:start position:0% +interesting the direction of the + + + align:start position:0% +interesting the direction of the +electric field is going to be rotating + + align:start position:0% +electric field is going to be rotating + + + align:start position:0% +electric field is going to be rotating +as a function of time as a function of + + align:start position:0% +as a function of time as a function of + + + align:start position:0% +as a function of time as a function of +the space this wave phase in trouble and + + align:start position:0% +the space this wave phase in trouble and + + + align:start position:0% +the space this wave phase in trouble and +that we actually call it circularly + + align:start position:0% +that we actually call it circularly + + + align:start position:0% +that we actually call it circularly +polarized waves and and we can also have + + align:start position:0% +polarized waves and and we can also have + + + align:start position:0% +polarized waves and and we can also have +a difficulty polarized wave then we + + align:start position:0% +a difficulty polarized wave then we + + + align:start position:0% +a difficulty polarized wave then we +learned about how to issue the two + + align:start position:0% +learned about how to issue the two + + + align:start position:0% +learned about how to issue the two +filtering which is actually the + + align:start position:0% +filtering which is actually the + + + align:start position:0% +filtering which is actually the +polarizer so suppose I have a perfect + + align:start position:0% +polarizer so suppose I have a perfect + + + align:start position:0% +polarizer so suppose I have a perfect +conductor here where I have the easy + + align:start position:0% +conductor here where I have the easy + + + align:start position:0% +conductor here where I have the easy +axis which is actually described by the + + align:start position:0% +axis which is actually described by the + + + align:start position:0% +axis which is actually described by the +green arrow there and you can see that + + align:start position:0% +green arrow there and you can see that + + + align:start position:0% +green arrow there and you can see that +easy access means that if you have + + align:start position:0% +easy access means that if you have + + + align:start position:0% +easy access means that if you have +electric field parallel to the + + align:start position:0% +electric field parallel to the + + + align:start position:0% +electric field parallel to the +axis okay and then since that's an easy + + align:start position:0% +axis okay and then since that's an easy + + + align:start position:0% +axis okay and then since that's an easy +axis so it's supposed to be easy + + align:start position:0% +axis so it's supposed to be easy + + + align:start position:0% +axis so it's supposed to be easy +therefore this electric field is going + + align:start position:0% +therefore this electric field is going + + + align:start position:0% +therefore this electric field is going +to be passing through the polarizer and + + align:start position:0% +to be passing through the polarizer and + + + align:start position:0% +to be passing through the polarizer and +the other hand if the electric field is + + align:start position:0% +the other hand if the electric field is + + + align:start position:0% +the other hand if the electric field is +perpendicular to the direction of the + + align:start position:0% +perpendicular to the direction of the + + + align:start position:0% +perpendicular to the direction of the +easy axis that means is taking the + + align:start position:0% +easy axis that means is taking the + + + align:start position:0% +easy axis that means is taking the +perfect conductor in a hard way + + align:start position:0% +perfect conductor in a hard way + + + align:start position:0% +perfect conductor in a hard way +therefore when I pass through when he is + + align:start position:0% +therefore when I pass through when he is + + + align:start position:0% +therefore when I pass through when he is +trying to pass through the appropriate + + align:start position:0% +trying to pass through the appropriate + + + align:start position:0% +trying to pass through the appropriate +conductor the electrons in those punkin + + align:start position:0% +conductor the electrons in those punkin + + + align:start position:0% +conductor the electrons in those punkin +data is going to be working like crazy + + align:start position:0% +data is going to be working like crazy + + + align:start position:0% +data is going to be working like crazy +to the fret this wave when the direction + + align:start position:0% +to the fret this wave when the direction + + + align:start position:0% +to the fret this wave when the direction +of the electric field is perpendicular + + align:start position:0% +of the electric field is perpendicular + + + align:start position:0% +of the electric field is perpendicular +to the direction of the easy axis okay + + align:start position:0% +to the direction of the easy axis okay + + + align:start position:0% +to the direction of the easy axis okay +so that is essentially how things as she + + align:start position:0% +so that is essentially how things as she + + + align:start position:0% +so that is essentially how things as she +works for example so in the you know + + align:start position:0% +works for example so in the you know + + + align:start position:0% +works for example so in the you know +first example you can see that in this + + align:start position:0% +first example you can see that in this + + + align:start position:0% +first example you can see that in this +case you have easy axis which is + + align:start position:0% +case you have easy axis which is + + + align:start position:0% +case you have easy axis which is +actually perpendicular to a direction of + + align:start position:0% +actually perpendicular to a direction of + + + align:start position:0% +actually perpendicular to a direction of +the electric field which is a red field + + align:start position:0% +the electric field which is a red field + + + align:start position:0% +the electric field which is a red field +then this wave says we got refracted + + align:start position:0% +then this wave says we got refracted + + + align:start position:0% +then this wave says we got refracted +there will be no transmission sorry no + + align:start position:0% +there will be no transmission sorry no + + + align:start position:0% +there will be no transmission sorry no +no are no electromagnetic field passing + + align:start position:0% +no are no electromagnetic field passing + + + align:start position:0% +no are no electromagnetic field passing +the perfect data and on the other hand + + align:start position:0% +the perfect data and on the other hand + + + align:start position:0% +the perfect data and on the other hand +if you have another perfect conductor + + align:start position:0% +if you have another perfect conductor + + + align:start position:0% +if you have another perfect conductor +which you have easy access which uses + + align:start position:0% +which you have easy access which uses + + + align:start position:0% +which you have easy access which uses +should be parallel to the electric field + + align:start position:0% +should be parallel to the electric field + + + align:start position:0% +should be parallel to the electric field +then you can actually you will see that + + align:start position:0% +then you can actually you will see that + + + align:start position:0% +then you can actually you will see that +actually you will pass through the the + + align:start position:0% +actually you will pass through the the + + + align:start position:0% +actually you will pass through the the +perfect conductor okay so that is + + align:start position:0% +perfect conductor okay so that is + + + align:start position:0% +perfect conductor okay so that is +actually the polarizer and also we + + align:start position:0% +actually the polarizer and also we + + + align:start position:0% +actually the polarizer and also we +discuss about a quarter wave plate which + + align:start position:0% +discuss about a quarter wave plate which + + + align:start position:0% +discuss about a quarter wave plate which +I always suggest you to have a review + + align:start position:0% +I always suggest you to have a review + + + align:start position:0% +I always suggest you to have a review +about the concept which we have learn + + align:start position:0% +about the concept which we have learn + + + align:start position:0% +about the concept which we have learn +about polarizer and quarter wave plate + + align:start position:0% +about polarizer and quarter wave plate + + + align:start position:0% +about polarizer and quarter wave plate +so that you make sure that you + + align:start position:0% +so that you make sure that you + + + align:start position:0% +so that you make sure that you +understand how to issue the calculate + + align:start position:0% +understand how to issue the calculate + + + align:start position:0% +understand how to issue the calculate +the electric field the electric field + + align:start position:0% +the electric field the electric field + + + align:start position:0% +the electric field the electric field +after passing through polarizer and + + align:start position:0% +after passing through polarizer and + + + align:start position:0% +after passing through polarizer and +quarter wave plate and how the security + + align:start position:0% +quarter wave plate and how the security + + + align:start position:0% +quarter wave plate and how the security +or elliptically polarized wave are + + align:start position:0% +or elliptically polarized wave are + + + align:start position:0% +or elliptically polarized wave are +created using this load all those + + align:start position:0% +created using this load all those + + + align:start position:0% +created using this load all those +WordPress etc + + align:start position:0% +WordPress etc + + + align:start position:0% +WordPress etc +okay all right so the next thing which + + align:start position:0% +okay all right so the next thing which + + + align:start position:0% +okay all right so the next thing which +we actually discussed during the class + + align:start position:0% +we actually discussed during the class + + + align:start position:0% +we actually discussed during the class +is how do we actually produce + + align:start position:0% +is how do we actually produce + + + align:start position:0% +is how do we actually produce +electromagnetic waves I think by now + + align:start position:0% +electromagnetic waves I think by now + + + align:start position:0% +electromagnetic waves I think by now +usually actually know that a stationary + + align:start position:0% +usually actually know that a stationary + + + align:start position:0% +usually actually know that a stationary +charge doesn't produce electromagnetic + + align:start position:0% +charge doesn't produce electromagnetic + + + align:start position:0% +charge doesn't produce electromagnetic +wave even a moving charge at constant + + align:start position:0% +wave even a moving charge at constant + + + align:start position:0% +wave even a moving charge at constant +speed doesn't create electromagnetic + + align:start position:0% +speed doesn't create electromagnetic + + + align:start position:0% +speed doesn't create electromagnetic +wave so how do we actually create + + align:start position:0% +wave so how do we actually create + + + align:start position:0% +wave so how do we actually create +electromagnetic wave which propagate to + + align:start position:0% +electromagnetic wave which propagate to + + + align:start position:0% +electromagnetic wave which propagate to +the edge of the universe that is + + align:start position:0% +the edge of the universe that is + + + align:start position:0% +the edge of the universe that is +actually the trick is to create a kink + + align:start position:0% +actually the trick is to create a kink + + + align:start position:0% +actually the trick is to create a kink +in the fuel line right so you have to + + align:start position:0% +in the fuel line right so you have to + + + align:start position:0% +in the fuel line right so you have to +accelerate and stop it okay accelerate + + align:start position:0% +accelerate and stop it okay accelerate + + + align:start position:0% +accelerate and stop it okay accelerate +and the end I'll try to h2 the stop the + + align:start position:0% +and the end I'll try to h2 the stop the + + + align:start position:0% +and the end I'll try to h2 the stop the +acceleration okay + + align:start position:0% +acceleration okay + + + align:start position:0% +acceleration okay +so then you can create a kink okay and + + align:start position:0% +so then you can create a kink okay and + + + align:start position:0% +so then you can create a kink okay and +this kink is going to be public ating + + align:start position:0% +this kink is going to be public ating + + + align:start position:0% +this kink is going to be public ating +out of the function of time and this + + align:start position:0% +out of the function of time and this + + + align:start position:0% +out of the function of time and this +kink is actually creating the so-called + + align:start position:0% +kink is actually creating the so-called + + + align:start position:0% +kink is actually creating the so-called +radiation from this accelerated charge + + align:start position:0% +radiation from this accelerated charge + + + align:start position:0% +radiation from this accelerated charge +so you don't really need to remember all + + align:start position:0% +so you don't really need to remember all + + + align:start position:0% +so you don't really need to remember all +the debris ation but you really need to + + align:start position:0% +the debris ation but you really need to + + + align:start position:0% +the debris ation but you really need to +know the conclusion so what is the + + align:start position:0% +know the conclusion so what is the + + + align:start position:0% +know the conclusion so what is the +conclusion is allowing the the radiated + + align:start position:0% +conclusion is allowing the the radiated + + + align:start position:0% +conclusion is allowing the the radiated +electric field is actually equal to + + align:start position:0% +electric field is actually equal to + + + align:start position:0% +electric field is actually equal to +minus very important is a minus sign in + + align:start position:0% +minus very important is a minus sign in + + + align:start position:0% +minus very important is a minus sign in +front of it which is a common mistake - + + align:start position:0% +front of it which is a common mistake - + + + align:start position:0% +front of it which is a common mistake - +to drop it and the Q is actually the + + align:start position:0% +to drop it and the Q is actually the + + + align:start position:0% +to drop it and the Q is actually the +charge of the oscillating the + + align:start position:0% +charge of the oscillating the + + + align:start position:0% +charge of the oscillating the +accelerated charge right proportional to + + align:start position:0% +accelerated charge right proportional to + + + align:start position:0% +accelerated charge right proportional to +the charge right if the particle is more + + align:start position:0% +the charge right if the particle is more + + + align:start position:0% +the charge right if the particle is more +charged then you have more radiation a + + align:start position:0% +charged then you have more radiation a + + + align:start position:0% +charged then you have more radiation a +perp is actually the the acceleration + + align:start position:0% +perp is actually the the acceleration + + + align:start position:0% +perp is actually the the acceleration +projected to which is the perpendicular + + align:start position:0% +projected to which is the perpendicular + + + align:start position:0% +projected to which is the perpendicular +projection of the acceleration of the + + align:start position:0% +projection of the acceleration of the + + + align:start position:0% +projection of the acceleration of the +particle with respect to the direction + + align:start position:0% +particle with respect to the direction + + + align:start position:0% +particle with respect to the direction +of propagation is actually so-called a + + align:start position:0% +of propagation is actually so-called a + + + align:start position:0% +of propagation is actually so-called a +perp and only the perpendicular + + align:start position:0% +perp and only the perpendicular + + + align:start position:0% +perp and only the perpendicular +Direction acceleration as she counts + + align:start position:0% +Direction acceleration as she counts + + + align:start position:0% +Direction acceleration as she counts +okay the one which is usually parallel + + align:start position:0% +okay the one which is usually parallel + + + align:start position:0% +okay the one which is usually parallel +to the Dirac + + align:start position:0% +to the Dirac + + + align:start position:0% +to the Dirac +no obligation doesn't really count as + + align:start position:0% +no obligation doesn't really count as + + + align:start position:0% +no obligation doesn't really count as +you can see from this equation and the T + + align:start position:0% +you can see from this equation and the T + + + align:start position:0% +you can see from this equation and the T +Prime what is T prime T prime is + + align:start position:0% +Prime what is T prime T prime is + + + align:start position:0% +Prime what is T prime T prime is +actually P minus RT by L divided by C so + + align:start position:0% +actually P minus RT by L divided by C so + + + align:start position:0% +actually P minus RT by L divided by C so +T prime is the time so that is + + align:start position:0% +T prime is the time so that is + + + align:start position:0% +T prime is the time so that is +actually tells you is telling you that + + align:start position:0% +actually tells you is telling you that + + + align:start position:0% +actually tells you is telling you that +it takes some time for the information + + align:start position:0% +it takes some time for the information + + + align:start position:0% +it takes some time for the information +to propagate from the origin which is + + align:start position:0% +to propagate from the origin which is + + + align:start position:0% +to propagate from the origin which is +the post position of the of the moving + + align:start position:0% +the post position of the of the moving + + + align:start position:0% +the post position of the of the moving +charge to the observer which is HD are + + align:start position:0% +charge to the observer which is HD are + + + align:start position:0% +charge to the observer which is HD are +this distance away from the moving + + align:start position:0% +this distance away from the moving + + + align:start position:0% +this distance away from the moving +charge okay so so the information takes + + align:start position:0% +charge okay so so the information takes + + + align:start position:0% +charge okay so so the information takes +some time to propagate and you cannot + + align:start position:0% +some time to propagate and you cannot + + + align:start position:0% +some time to propagate and you cannot +know what is actually really happening + + align:start position:0% +know what is actually really happening + + + align:start position:0% +know what is actually really happening +for example 100 light years away from + + align:start position:0% +for example 100 light years away from + + + align:start position:0% +for example 100 light years away from +Earth as you have no idea about what is + + align:start position:0% +Earth as you have no idea about what is + + + align:start position:0% +Earth as you have no idea about what is +happening maybe a black hole is created + + align:start position:0% +happening maybe a black hole is created + + + align:start position:0% +happening maybe a black hole is created +there and it's going to do so suckers + + align:start position:0% +there and it's going to do so suckers + + + align:start position:0% +there and it's going to do so suckers +everybody up in a few years but nobody + + align:start position:0% +everybody up in a few years but nobody + + + align:start position:0% +everybody up in a few years but nobody +know and though we don't care because we + + align:start position:0% +know and though we don't care because we + + + align:start position:0% +know and though we don't care because we +cannot control all right all right so + + align:start position:0% +cannot control all right all right so + + + align:start position:0% +cannot control all right all right so +that is actually very important also + + align:start position:0% +that is actually very important also + + + align:start position:0% +that is actually very important also +very important to know the magnetic + + align:start position:0% +very important to know the magnetic + + + align:start position:0% +very important to know the magnetic +field map it must be there you can see + + align:start position:0% +field map it must be there you can see + + + align:start position:0% +field map it must be there you can see +the relation between magnetic field and + + align:start position:0% +the relation between magnetic field and + + + align:start position:0% +the relation between magnetic field and +the electric field and the pointing + + align:start position:0% +the electric field and the pointing + + + align:start position:0% +the electric field and the pointing +vector is actually also a short field + + align:start position:0% +vector is actually also a short field + + + align:start position:0% +vector is actually also a short field +and when we actually went ahead are + + align:start position:0% +and when we actually went ahead are + + + align:start position:0% +and when we actually went ahead are +given all the knowledge we have learned + + align:start position:0% +given all the knowledge we have learned + + + align:start position:0% +given all the knowledge we have learned +we discuss about how to take very + + align:start position:0% +we discuss about how to take very + + + align:start position:0% +we discuss about how to take very +beautiful photo using polarizer filter + + align:start position:0% +beautiful photo using polarizer filter + + + align:start position:0% +beautiful photo using polarizer filter +and we discuss about how to filter out + + align:start position:0% +and we discuss about how to filter out + + + align:start position:0% +and we discuss about how to filter out +the scattered light from the Sun and + + align:start position:0% +the scattered light from the Sun and + + + align:start position:0% +the scattered light from the Sun and +you'll be in - it would be nice to + + align:start position:0% +you'll be in - it would be nice to + + + align:start position:0% +you'll be in - it would be nice to +figure out why this is the case how this + + align:start position:0% +figure out why this is the case how this + + + align:start position:0% +figure out why this is the case how this +apologizer light scatter iliza created + + align:start position:0% +apologizer light scatter iliza created + + + align:start position:0% +apologizer light scatter iliza created +okay is purely geometric oh and also we + + align:start position:0% +okay is purely geometric oh and also we + + + align:start position:0% +okay is purely geometric oh and also we +discuss about Brewster's angle and also + + align:start position:0% +discuss about Brewster's angle and also + + + align:start position:0% +discuss about Brewster's angle and also +how HD la as UD to the explanation of + + align:start position:0% +how HD la as UD to the explanation of + + + align:start position:0% +how HD la as UD to the explanation of +the filtering of the light the refracted + + align:start position:0% +the filtering of the light the refracted + + + align:start position:0% +the filtering of the light the refracted +light from fondo with ample window of a + + align:start position:0% +light from fondo with ample window of a + + + align:start position:0% +light from fondo with ample window of a +car or from from the water and this is + + align:start position:0% +car or from from the water and this is + + + align:start position:0% +car or from from the water and this is +actually a demonstration of the summary + + align:start position:0% +actually a demonstration of the summary + + + align:start position:0% +actually a demonstration of the summary +of two + + align:start position:0% +of two + + + align:start position:0% +of two +Stangl so HD so somebody reminded me + + align:start position:0% +Stangl so HD so somebody reminded me + + + align:start position:0% +Stangl so HD so somebody reminded me +that the amplitude should be given as I + + align:start position:0% +that the amplitude should be given as I + + + align:start position:0% +that the amplitude should be given as I +think if this is actually the amplitude + + align:start position:0% +think if this is actually the amplitude + + + align:start position:0% +think if this is actually the amplitude +formula for Brewster's angle will be + + align:start position:0% +formula for Brewster's angle will be + + + align:start position:0% +formula for Brewster's angle will be +given to you if that is actually asked + + align:start position:0% +given to you if that is actually asked + + + align:start position:0% +given to you if that is actually asked +in the in the final exam so don't be + + align:start position:0% +in the in the final exam so don't be + + + align:start position:0% +in the in the final exam so don't be +worried about it and you don't have to + + align:start position:0% +worried about it and you don't have to + + + align:start position:0% +worried about it and you don't have to +remember this formula and I'm not going + + align:start position:0% +remember this formula and I'm not going + + + align:start position:0% +remember this formula and I'm not going +to ask you to derive de to sing such a + + align:start position:0% +to ask you to derive de to sing such a + + + align:start position:0% +to ask you to derive de to sing such a +short time that three hours in the final + + align:start position:0% +short time that three hours in the final + + + align:start position:0% +short time that three hours in the final +exam but the what is actually very + + align:start position:0% +exam but the what is actually very + + + align:start position:0% +exam but the what is actually very +important is to know how this Brewster's + + align:start position:0% +important is to know how this Brewster's + + + align:start position:0% +important is to know how this Brewster's +angle why there's no refracted light + + align:start position:0% +angle why there's no refracted light + + + align:start position:0% +angle why there's no refracted light +polarized in the in a way that you know + + align:start position:0% +polarized in the in a way that you know + + + align:start position:0% +polarized in the in a way that you know +the the polarization should be why the + + align:start position:0% +the the polarization should be why the + + + align:start position:0% +the the polarization should be why the +refracted light is actually polarized + + align:start position:0% +refracted light is actually polarized + + + align:start position:0% +refracted light is actually polarized +for example and also why the the + + align:start position:0% +for example and also why the the + + + align:start position:0% +for example and also why the the +transmission transmitted wave is a + + align:start position:0% +transmission transmitted wave is a + + + align:start position:0% +transmission transmitted wave is a +suicide be polarized and I think the + + align:start position:0% +suicide be polarized and I think the + + + align:start position:0% +suicide be polarized and I think the +conclusions you need to remember and and + + align:start position:0% +conclusions you need to remember and and + + + align:start position:0% +conclusions you need to remember and and +the you need to know how to calculate + + align:start position:0% +the you need to know how to calculate + + + align:start position:0% +the you need to know how to calculate +the angle at least right because for + + align:start position:0% +the angle at least right because for + + + align:start position:0% +the angle at least right because for +this poor depolarized lied to be + + align:start position:0% +this poor depolarized lied to be + + + align:start position:0% +this poor depolarized lied to be +produced in the refracted light you need + + align:start position:0% +produced in the refracted light you need + + + align:start position:0% +produced in the refracted light you need +to have normal angle between the + + align:start position:0% +to have normal angle between the + + + align:start position:0% +to have normal angle between the +direction of the refracted light in the + + align:start position:0% +direction of the refracted light in the + + + align:start position:0% +direction of the refracted light in the +direction of the transmitted light and + + align:start position:0% +direction of the transmitted light and + + + align:start position:0% +direction of the transmitted light and +that you should be able to remember + + align:start position:0% +that you should be able to remember + + + align:start position:0% +that you should be able to remember +right and you should be able to derive + + align:start position:0% +right and you should be able to derive + + + align:start position:0% +right and you should be able to derive +down so from your mind as well because + + align:start position:0% +down so from your mind as well because + + + align:start position:0% +down so from your mind as well because +that means the direction of the + + align:start position:0% +that means the direction of the + + + align:start position:0% +that means the direction of the +oscillation of the molecule at the + + align:start position:0% +oscillation of the molecule at the + + + align:start position:0% +oscillation of the molecule at the +boundary will be actually in the + + align:start position:0% +boundary will be actually in the + + + align:start position:0% +boundary will be actually in the +direction of publication of the + + align:start position:0% +direction of publication of the + + + align:start position:0% +direction of publication of the +refracted ray therefore that cannot be a + + align:start position:0% +refracted ray therefore that cannot be a + + + align:start position:0% +refracted ray therefore that cannot be a +solution to the proper Singh in a two + + align:start position:0% +solution to the proper Singh in a two + + + align:start position:0% +solution to the proper Singh in a two +magnetic wave therefore the refractive + + align:start position:0% +magnetic wave therefore the refractive + + + align:start position:0% +magnetic wave therefore the refractive +waves are polarized right so if you + + align:start position:0% +waves are polarized right so if you + + + align:start position:0% +waves are polarized right so if you +follow this logic then you don't really + + align:start position:0% +follow this logic then you don't really + + + align:start position:0% +follow this logic then you don't really +need to to memorize all those formulas + + align:start position:0% +need to to memorize all those formulas + + + align:start position:0% +need to to memorize all those formulas +all right so finally in the last part of + + align:start position:0% +all right so finally in the last part of + + + align:start position:0% +all right so finally in the last part of +the course we focus on the superpussy + + align:start position:0% +the course we focus on the superpussy + + + align:start position:0% +the course we focus on the superpussy +of many many electromagnetic wave so it + + align:start position:0% +of many many electromagnetic wave so it + + + align:start position:0% +of many many electromagnetic wave so it +can produce constructive interference or + + align:start position:0% +can produce constructive interference or + + + align:start position:0% +can produce constructive interference or +that means all those waves are in phase + + align:start position:0% +that means all those waves are in phase + + + align:start position:0% +that means all those waves are in phase +right and you can have destructive + + align:start position:0% +right and you can have destructive + + + align:start position:0% +right and you can have destructive +interference when they are out of phase + + align:start position:0% +interference when they are out of phase + + + align:start position:0% +interference when they are out of phase +okay and that is actually very important + + align:start position:0% +okay and that is actually very important + + + align:start position:0% +okay and that is actually very important +topic as you should review that for the + + align:start position:0% +topic as you should review that for the + + + align:start position:0% +topic as you should review that for the +preparation of the final and you can see + + align:start position:0% +preparation of the final and you can see + + + align:start position:0% +preparation of the final and you can see +that the distri concrete example which + + align:start position:0% +that the distri concrete example which + + + align:start position:0% +that the distri concrete example which +we use during the class a laser beam we + + align:start position:0% +we use during the class a laser beam we + + + align:start position:0% +we use during the class a laser beam we +talked about water ripple you know demo + + align:start position:0% +talked about water ripple you know demo + + + align:start position:0% +talked about water ripple you know demo +and we also studied how to issue the + + align:start position:0% +and we also studied how to issue the + + + align:start position:0% +and we also studied how to issue the +make use of this phenomena to design a + + align:start position:0% +make use of this phenomena to design a + + + align:start position:0% +make use of this phenomena to design a +phased radar so to detect this unknown + + align:start position:0% +phased radar so to detect this unknown + + + align:start position:0% +phased radar so to detect this unknown +object and Skype what we actually really + + align:start position:0% +object and Skype what we actually really + + + align:start position:0% +object and Skype what we actually really +need to have electromagnetic wave + + align:start position:0% +need to have electromagnetic wave + + + align:start position:0% +need to have electromagnetic wave +pointing to a specific direction and + + align:start position:0% +pointing to a specific direction and + + + align:start position:0% +pointing to a specific direction and +that can be achieved by using motifs + + align:start position:0% +that can be achieved by using motifs + + + align:start position:0% +that can be achieved by using motifs +lead trans motifs lead interference and + + align:start position:0% +lead trans motifs lead interference and + + + align:start position:0% +lead trans motifs lead interference and +this is actually that the property of + + align:start position:0% +this is actually that the property of + + + align:start position:0% +this is actually that the property of +the two slit interference pattern and + + align:start position:0% +the two slit interference pattern and + + + align:start position:0% +the two slit interference pattern and +you are going to have many many Peaks + + align:start position:0% +you are going to have many many Peaks + + + align:start position:0% +you are going to have many many Peaks +they have equal height I for two slit + + align:start position:0% +they have equal height I for two slit + + + align:start position:0% +they have equal height I for two slit +interference if you ignore any if that + + align:start position:0% +interference if you ignore any if that + + + align:start position:0% +interference if you ignore any if that +coming from diffraction okay so if we + + align:start position:0% +coming from diffraction okay so if we + + + align:start position:0% +coming from diffraction okay so if we +assume that the speed is I should + + align:start position:0% +assume that the speed is I should + + + align:start position:0% +assume that the speed is I should +infinite this small right the slit is + + align:start position:0% +infinite this small right the slit is + + + align:start position:0% +infinite this small right the slit is +super duper narrow and then we can + + align:start position:0% +super duper narrow and then we can + + + align:start position:0% +super duper narrow and then we can +actually ignore the diffraction a single + + align:start position:0% +actually ignore the diffraction a single + + + align:start position:0% +actually ignore the diffraction a single +slit diffraction if that then all the + + align:start position:0% +slit diffraction if that then all the + + + align:start position:0% +slit diffraction if that then all the +peaks due to these two slit interference + + align:start position:0% +peaks due to these two slit interference + + + align:start position:0% +peaks due to these two slit interference +we have the same height on the other + + align:start position:0% +we have the same height on the other + + + align:start position:0% +we have the same height on the other +hand when we actually start to increase + + align:start position:0% +hand when we actually start to increase + + + align:start position:0% +hand when we actually start to increase +the number of sleet for example n equal + + align:start position:0% +the number of sleet for example n equal + + + align:start position:0% +the number of sleet for example n equal +to 3 n equal to 4 and equal to 5 and + + align:start position:0% +to 3 n equal to 4 and equal to 5 and + + + align:start position:0% +to 3 n equal to 4 and equal to 5 and +equal to 6 because you can see that the + + align:start position:0% +equal to 6 because you can see that the + + + align:start position:0% +equal to 6 because you can see that the +structure of the intensity as a function + + align:start position:0% +structure of the intensity as a function + + + align:start position:0% +structure of the intensity as a function +of delta which stuff which is the phase + + align:start position:0% +of delta which stuff which is the phase + + + align:start position:0% +of delta which stuff which is the phase +difference is actually changing and you + + align:start position:0% +difference is actually changing and you + + + align:start position:0% +difference is actually changing and you +can see that the general + + align:start position:0% +can see that the general + + + align:start position:0% +can see that the general +structure is the powering so if you have + + align:start position:0% +structure is the powering so if you have + + + align:start position:0% +structure is the powering so if you have +an equal to 3 then basically you have to + + align:start position:0% +an equal to 3 then basically you have to + + + align:start position:0% +an equal to 3 then basically you have to +add ow and and between then you have one + + align:start position:0% +add ow and and between then you have one + + + align:start position:0% +add ow and and between then you have one +child and if you have unequal to 6 then + + align:start position:0% +child and if you have unequal to 6 then + + + align:start position:0% +child and if you have unequal to 6 then +basically you have to word out and + + align:start position:0% +basically you have to word out and + + + align:start position:0% +basically you have to word out and +somehow there are four children in in + + align:start position:0% +somehow there are four children in in + + + align:start position:0% +somehow there are four children in in +this collection right so basically a lot + + align:start position:0% +this collection right so basically a lot + + + align:start position:0% +this collection right so basically a lot +is actually what is we actually learn + + align:start position:0% +is actually what is we actually learn + + + align:start position:0% +is actually what is we actually learn +from the solution of the motifs lead + + align:start position:0% +from the solution of the motifs lead + + + align:start position:0% +from the solution of the motifs lead +interference and though in this way we + + align:start position:0% +interference and though in this way we + + + align:start position:0% +interference and though in this way we +can actually make the wheels of the + + align:start position:0% +can actually make the wheels of the + + + align:start position:0% +can actually make the wheels of the +principal Maxima as narrow as you you + + align:start position:0% +principal Maxima as narrow as you you + + + align:start position:0% +principal Maxima as narrow as you you +want okay so that is actually why first + + align:start position:0% +want okay so that is actually why first + + + align:start position:0% +want okay so that is actually why first +phase the radii works and then we + + align:start position:0% +phase the radii works and then we + + + align:start position:0% +phase the radii works and then we +discuss about the fraction so so that is + + align:start position:0% +discuss about the fraction so so that is + + + align:start position:0% +discuss about the fraction so so that is +AG related again to the the explanation + + align:start position:0% +AG related again to the the explanation + + + align:start position:0% +AG related again to the the explanation +of laser ping and we discuss about the + + align:start position:0% +of laser ping and we discuss about the + + + align:start position:0% +of laser ping and we discuss about the +design of a Star Trek ship the gun front + + align:start position:0% +design of a Star Trek ship the gun front + + + align:start position:0% +design of a Star Trek ship the gun front +for the ship and we also talk about + + align:start position:0% +for the ship and we also talk about + + + align:start position:0% +for the ship and we also talk about +resolution and what is actually + + align:start position:0% +resolution and what is actually + + + align:start position:0% +resolution and what is actually +happening here is the following singles + + align:start position:0% +happening here is the following singles + + + align:start position:0% +happening here is the following singles +the diffraction is actually can be + + align:start position:0% +the diffraction is actually can be + + + align:start position:0% +the diffraction is actually can be +viewed as infinite number of source + + align:start position:0% +viewed as infinite number of source + + + align:start position:0% +viewed as infinite number of source +interference right and you just need to + + align:start position:0% +interference right and you just need to + + + align:start position:0% +interference right and you just need to +integrate over order or the point like + + align:start position:0% +integrate over order or the point like + + + align:start position:0% +integrate over order or the point like +source between between the two wars and + + align:start position:0% +source between between the two wars and + + + align:start position:0% +source between between the two wars and +all of them are acting like severe cold + + align:start position:0% +all of them are acting like severe cold + + + align:start position:0% +all of them are acting like severe cold +wave source right so basically for every + + align:start position:0% +wave source right so basically for every + + + align:start position:0% +wave source right so basically for every +point continuously every points between + + align:start position:0% +point continuously every points between + + + align:start position:0% +point continuously every points between +these two was a point source of vertical + + align:start position:0% +these two was a point source of vertical + + + align:start position:0% +these two was a point source of vertical +wave and that is actually a Huygens + + align:start position:0% +wave and that is actually a Huygens + + + align:start position:0% +wave and that is actually a Huygens +principle and we can see that the + + align:start position:0% +principle and we can see that the + + + align:start position:0% +principle and we can see that the +structures of the intensity as a + + align:start position:0% +structures of the intensity as a + + + align:start position:0% +structures of the intensity as a +function of position is the following so + + align:start position:0% +function of position is the following so + + + align:start position:0% +function of position is the following so +basically you have a principal Maxima + + align:start position:0% +basically you have a principal Maxima + + + align:start position:0% +basically you have a principal Maxima +which is actually a peak at in the + + align:start position:0% +which is actually a peak at in the + + + align:start position:0% +which is actually a peak at in the +middle and at some angle basically you + + align:start position:0% +middle and at some angle basically you + + + align:start position:0% +middle and at some angle basically you +have destructive interference such that + + align:start position:0% +have destructive interference such that + + + align:start position:0% +have destructive interference such that +if you integrate over all the + + align:start position:0% +if you integrate over all the + + + align:start position:0% +if you integrate over all the +contribution of infinite number source + + align:start position:0% +contribution of infinite number source + + + align:start position:0% +contribution of infinite number source +in this window basically you see that + + align:start position:0% +in this window basically you see that + + + align:start position:0% +in this window basically you see that +they completely cancel each other so + + align:start position:0% +they completely cancel each other so + + + align:start position:0% +they completely cancel each other so +that is actually the origin of all those + + align:start position:0% +that is actually the origin of all those + + + align:start position:0% +that is actually the origin of all those +this the tip structure minima and then + + align:start position:0% +this the tip structure minima and then + + + align:start position:0% +this the tip structure minima and then +after the minima issue did you see + + align:start position:0% +after the minima issue did you see + + + align:start position:0% +after the minima issue did you see +another peak but the height of the peak + + align:start position:0% +another peak but the height of the peak + + + align:start position:0% +another peak but the height of the peak +is a is suppressed by 1 over beta square + + align:start position:0% +is a is suppressed by 1 over beta square + + + align:start position:0% +is a is suppressed by 1 over beta square +and it would be good to review that and + + align:start position:0% +and it would be good to review that and + + + align:start position:0% +and it would be good to review that and +what is actually the consequence so if + + align:start position:0% +what is actually the consequence so if + + + align:start position:0% +what is actually the consequence so if +you shoot a laser beam to the to the + + align:start position:0% +you shoot a laser beam to the to the + + + align:start position:0% +you shoot a laser beam to the to the +moon basically the size of the laser + + align:start position:0% +moon basically the size of the laser + + + align:start position:0% +moon basically the size of the laser +beam will be very large + + align:start position:0% +beam will be very large + + + align:start position:0% +beam will be very large +after you learn it was three you know + + align:start position:0% +after you learn it was three you know + + + align:start position:0% +after you learn it was three you know +that the size of the laser beam is going + + align:start position:0% +that the size of the laser beam is going + + + align:start position:0% +that the size of the laser beam is going +to be very very large due to + + align:start position:0% +to be very very large due to + + + align:start position:0% +to be very very large due to +interference between all the point x + + align:start position:0% +interference between all the point x + + + align:start position:0% +interference between all the point x +source from the funded isoprene okay and + + align:start position:0% +source from the funded isoprene okay and + + + align:start position:0% +source from the funded isoprene okay and +finally we can put them all together so + + align:start position:0% +finally we can put them all together so + + + align:start position:0% +finally we can put them all together so +the single slit diffraction and the + + align:start position:0% +the single slit diffraction and the + + + align:start position:0% +the single slit diffraction and the +mattias lead interference you can put + + align:start position:0% +mattias lead interference you can put + + + align:start position:0% +mattias lead interference you can put +them all together and basically what you + + align:start position:0% +them all together and basically what you + + + align:start position:0% +them all together and basically what you +you get is the power so basically you + + align:start position:0% +you get is the power so basically you + + + align:start position:0% +you get is the power so basically you +have what is the interference pattern + + align:start position:0% +have what is the interference pattern + + + align:start position:0% +have what is the interference pattern +which is shown there but the now the + + align:start position:0% +which is shown there but the now the + + + align:start position:0% +which is shown there but the now the +intensity of the motifs the pattern is + + align:start position:0% +intensity of the motifs the pattern is + + + align:start position:0% +intensity of the motifs the pattern is +modulated by the single slit diffraction + + align:start position:0% +modulated by the single slit diffraction + + + align:start position:0% +modulated by the single slit diffraction +pattern and of course the the for + + align:start position:0% +pattern and of course the the for + + + align:start position:0% +pattern and of course the the for +formula will be given to you but on the + + align:start position:0% +formula will be given to you but on the + + + align:start position:0% +formula will be given to you but on the +other hand you are also requested to to + + align:start position:0% +other hand you are also requested to to + + + align:start position:0% +other hand you are also requested to to +know how to actually calculate just to + + align:start position:0% +know how to actually calculate just to + + + align:start position:0% +know how to actually calculate just to +add the contribution from you know + + align:start position:0% +add the contribution from you know + + + align:start position:0% +add the contribution from you know +motifs sleep together in case if we + + align:start position:0% +motifs sleep together in case if we + + + align:start position:0% +motifs sleep together in case if we +actually change the amplitude of the + + align:start position:0% +actually change the amplitude of the + + + align:start position:0% +actually change the amplitude of the +incident light or we change the face + + align:start position:0% +incident light or we change the face + + + align:start position:0% +incident light or we change the face +like what we should in the homework okay + + align:start position:0% +like what we should in the homework okay + + + align:start position:0% +like what we should in the homework okay +and I think that is should be one + + align:start position:0% +and I think that is should be one + + + align:start position:0% +and I think that is should be one +important point and you should actually + + align:start position:0% +important point and you should actually + + + align:start position:0% +important point and you should actually +review that and if you are not if you + + align:start position:0% +review that and if you are not if you + + + align:start position:0% +review that and if you are not if you +are not sure about how to proceed with + + align:start position:0% +are not sure about how to proceed with + + + align:start position:0% +are not sure about how to proceed with +that you would be good to review lecture + + align:start position:0% +that you would be good to review lecture + + + align:start position:0% +that you would be good to review lecture +22 nature 23 so finally we talked about + + align:start position:0% +22 nature 23 so finally we talked about + + + align:start position:0% +22 nature 23 so finally we talked about +the connection to quantum mechanics so + + align:start position:0% +the connection to quantum mechanics so + + + align:start position:0% +the connection to quantum mechanics so +Einstein already told us that I have + + align:start position:0% +Einstein already told us that I have + + + align:start position:0% +Einstein already told us that I have +said so many times + + align:start position:0% +said so many times + + + align:start position:0% +said so many times +God doesn't pray + + align:start position:0% +God doesn't pray + + + align:start position:0% +God doesn't pray +ties with the world but what we actually + + align:start position:0% +ties with the world but what we actually + + + align:start position:0% +ties with the world but what we actually +find is that there are two very + + align:start position:0% +find is that there are two very + + + align:start position:0% +find is that there are two very +interesting scene which we found the + + align:start position:0% +interesting scene which we found the + + + align:start position:0% +interesting scene which we found the +first thing is that if we have a single + + align:start position:0% +first thing is that if we have a single + + + align:start position:0% +first thing is that if we have a single +photon source and basically if we don't + + align:start position:0% +photon source and basically if we don't + + + align:start position:0% +photon source and basically if we don't +if we don't play dice we cannot HD + + align:start position:0% +if we don't play dice we cannot HD + + + align:start position:0% +if we don't play dice we cannot HD +explain the intensity of the okay after + + align:start position:0% +explain the intensity of the okay after + + + align:start position:0% +explain the intensity of the okay after +this single photon source passed through + + align:start position:0% +this single photon source passed through + + + align:start position:0% +this single photon source passed through +two polarizers and what happens is the + + align:start position:0% +two polarizers and what happens is the + + + align:start position:0% +two polarizers and what happens is the +power in so basically the result of a + + align:start position:0% +power in so basically the result of a + + + align:start position:0% +power in so basically the result of a +single photon source tells you that you + + align:start position:0% +single photon source tells you that you + + + align:start position:0% +single photon source tells you that you +would really need to pray ties so that + + align:start position:0% +would really need to pray ties so that + + + align:start position:0% +would really need to pray ties so that +you can actually get the result without + + align:start position:0% +you can actually get the result without + + + align:start position:0% +you can actually get the result without +it without in polarized light intensity + + align:start position:0% +it without in polarized light intensity + + + align:start position:0% +it without in polarized light intensity +and also the second as pseudo experiment + + align:start position:0% +and also the second as pseudo experiment + + + align:start position:0% +and also the second as pseudo experiment +we actually discuss is that if you have + + align:start position:0% +we actually discuss is that if you have + + + align:start position:0% +we actually discuss is that if you have +video board basically you have have been + + align:start position:0% +video board basically you have have been + + + align:start position:0% +video board basically you have have been +pass through the two slit experiment + + align:start position:0% +pass through the two slit experiment + + + align:start position:0% +pass through the two slit experiment +basically you are going to get is too + + align:start position:0% +basically you are going to get is too + + + align:start position:0% +basically you are going to get is too +pious Gaussian light distribution and if + + align:start position:0% +pious Gaussian light distribution and if + + + align:start position:0% +pious Gaussian light distribution and if +you have a single electron source what + + align:start position:0% +you have a single electron source what + + + align:start position:0% +you have a single electron source what +it does is that you actually interfere + + align:start position:0% +it does is that you actually interfere + + + align:start position:0% +it does is that you actually interfere +with itself as an electron single + + align:start position:0% +with itself as an electron single + + + align:start position:0% +with itself as an electron single +electron can interfere with itself and + + align:start position:0% +electron can interfere with itself and + + + align:start position:0% +electron can interfere with itself and +produce a pattern which is actually very + + align:start position:0% +produce a pattern which is actually very + + + align:start position:0% +produce a pattern which is actually very +similar to what we see in the top was + + align:start position:0% +similar to what we see in the top was + + + align:start position:0% +similar to what we see in the top was +lead interference pattern so that is + + align:start position:0% +lead interference pattern so that is + + + align:start position:0% +lead interference pattern so that is +actually really remarkable and also we + + align:start position:0% +actually really remarkable and also we + + + align:start position:0% +actually really remarkable and also we +talk about a single slit single electron + + align:start position:0% +talk about a single slit single electron + + + align:start position:0% +talk about a single slit single electron +experiment basically that give you also + + align:start position:0% +experiment basically that give you also + + + align:start position:0% +experiment basically that give you also +diffraction pattern we have to use the + + align:start position:0% +diffraction pattern we have to use the + + + align:start position:0% +diffraction pattern we have to use the +wave function to describe the position + + align:start position:0% +wave function to describe the position + + + align:start position:0% +wave function to describe the position +the probability density of the position + + align:start position:0% +the probability density of the position + + + align:start position:0% +the probability density of the position +of the electron on the screen and that + + align:start position:0% +of the electron on the screen and that + + + align:start position:0% +of the electron on the screen and that +is actually closely connected to the + + align:start position:0% +is actually closely connected to the + + + align:start position:0% +is actually closely connected to the +uncertainty principle which we as we + + align:start position:0% +uncertainty principle which we as we + + + align:start position:0% +uncertainty principle which we as we +discussed earlier Delta P Delta X + + align:start position:0% +discussed earlier Delta P Delta X + + + align:start position:0% +discussed earlier Delta P Delta X +greater or equal to H bar over 2 so if + + align:start position:0% +greater or equal to H bar over 2 so if + + + align:start position:0% +greater or equal to H bar over 2 so if +you have a very narrow window that means + + align:start position:0% +you have a very narrow window that means + + + align:start position:0% +you have a very narrow window that means +you have very small Delta + + align:start position:0% +you have very small Delta + + + align:start position:0% +you have very small Delta +so you have you have very very good + + align:start position:0% +so you have you have very very good + + + align:start position:0% +so you have you have very very good +confidence about the location of the + + align:start position:0% +confidence about the location of the + + + align:start position:0% +confidence about the location of the +electron and then the momentum he says + + align:start position:0% +electron and then the momentum he says + + + align:start position:0% +electron and then the momentum he says +in the next project the momentum in the + + align:start position:0% +in the next project the momentum in the + + + align:start position:0% +in the next project the momentum in the +X direction you have large uncertainty + + align:start position:0% +X direction you have large uncertainty + + + align:start position:0% +X direction you have large uncertainty +according to this equation and that + + align:start position:0% +according to this equation and that + + + align:start position:0% +according to this equation and that +essentially can be seen from this single + + align:start position:0% +essentially can be seen from this single + + + align:start position:0% +essentially can be seen from this single +slit diffraction diffraction pattern and + + align:start position:0% +slit diffraction diffraction pattern and + + + align:start position:0% +slit diffraction diffraction pattern and +in this course we connected to what we + + align:start position:0% +in this course we connected to what we + + + align:start position:0% +in this course we connected to what we +have learned before so where's this how + + align:start position:0% +have learned before so where's this how + + + align:start position:0% +have learned before so where's this how +to actually describe the what this issue + + align:start position:0% +to actually describe the what this issue + + + align:start position:0% +to actually describe the what this issue +is really the dispersion relation okay + + align:start position:0% +is really the dispersion relation okay + + + align:start position:0% +is really the dispersion relation okay +of the probability density wave is + + align:start position:0% +of the probability density wave is + + + align:start position:0% +of the probability density wave is +actually coming from showing the strong + + align:start position:0% +actually coming from showing the strong + + + align:start position:0% +actually coming from showing the strong +vigorous equation and this is actually + + align:start position:0% +vigorous equation and this is actually + + + align:start position:0% +vigorous equation and this is actually +given here we actually previously talked + + align:start position:0% +given here we actually previously talked + + + align:start position:0% +given here we actually previously talked +about that and and the consequence is + + align:start position:0% +about that and and the consequence is + + + align:start position:0% +about that and and the consequence is +appalling so basically you can actually + + align:start position:0% +appalling so basically you can actually + + + align:start position:0% +appalling so basically you can actually +describe the evolution of the wave + + align:start position:0% +describe the evolution of the wave + + + align:start position:0% +describe the evolution of the wave +function as a function of time by using + + align:start position:0% +function as a function of time by using + + + align:start position:0% +function as a function of time by using +this wave equation and this wave + + align:start position:0% +this wave equation and this wave + + + align:start position:0% +this wave equation and this wave +equation says she decided different from + + align:start position:0% +equation says she decided different from + + + align:start position:0% +equation says she decided different from +what we actually have learned before and + + align:start position:0% +what we actually have learned before and + + + align:start position:0% +what we actually have learned before and +we also can use what we have learned + + align:start position:0% +we also can use what we have learned + + + align:start position:0% +we also can use what we have learned +from l3 to solve + + align:start position:0% +from l3 to solve + + + align:start position:0% +from l3 to solve +particle in a box problem which is + + align:start position:0% +particle in a box problem which is + + + align:start position:0% +particle in a box problem which is +actually covered in lecture number 23 + + align:start position:0% +actually covered in lecture number 23 + + + align:start position:0% +actually covered in lecture number 23 +and I just want to say that you need to + + align:start position:0% +and I just want to say that you need to + + + align:start position:0% +and I just want to say that you need to +know the general principle but I'm not + + align:start position:0% +know the general principle but I'm not + + + align:start position:0% +know the general principle but I'm not +teaching ao4 so I'm not expecting you to + + align:start position:0% +teaching ao4 so I'm not expecting you to + + + align:start position:0% +teaching ao4 so I'm not expecting you to +solve quantum mechanics + + align:start position:0% +solve quantum mechanics + + + align:start position:0% +solve quantum mechanics +pappan but i would like to say that okay + + align:start position:0% +pappan but i would like to say that okay + + + align:start position:0% +pappan but i would like to say that okay +from this point he says should be + + align:start position:0% +from this point he says should be + + + align:start position:0% +from this point he says should be +motivating you to take a oh for right + + align:start position:0% +motivating you to take a oh for right + + + align:start position:0% +motivating you to take a oh for right +because there can be a lot of fun there + + align:start position:0% +because there can be a lot of fun there + + + align:start position:0% +because there can be a lot of fun there +as well and is actually closely related + + align:start position:0% +as well and is actually closely related + + + align:start position:0% +as well and is actually closely related +to what we have learned from elf ao3 + + align:start position:0% +to what we have learned from elf ao3 + + + align:start position:0% +to what we have learned from elf ao3 +so I just want to say in the last point + + align:start position:0% +so I just want to say in the last point + + + align:start position:0% +so I just want to say in the last point +is that this is actually really not the + + align:start position:0% +is that this is actually really not the + + + align:start position:0% +is that this is actually really not the +end of the vibrational waves it's just + + align:start position:0% +end of the vibrational waves it's just + + + align:start position:0% +end of the vibrational waves it's just +the beginning and there's a path toward + + align:start position:0% +the beginning and there's a path toward + + + align:start position:0% +the beginning and there's a path toward +a peak and you may take a long time to + + align:start position:0% +a peak and you may take a long time to + + + align:start position:0% +a peak and you may take a long time to +reach the peak + + align:start position:0% +reach the peak + + + align:start position:0% +reach the peak +all right and I would like to let you + + align:start position:0% +all right and I would like to let you + + + align:start position:0% +all right and I would like to let you +know that I'm really really very happy + + align:start position:0% +know that I'm really really very happy + + + align:start position:0% +know that I'm really really very happy +to be your lecturer this semester and I + + align:start position:0% +to be your lecturer this semester and I + + + align:start position:0% +to be your lecturer this semester and I +really enjoy teaching this class and + + align:start position:0% +really enjoy teaching this class and + + + align:start position:0% +really enjoy teaching this class and +getting your response when I ask + + align:start position:0% +getting your response when I ask + + + align:start position:0% +getting your response when I ask +questions thank you for the support and + + align:start position:0% +questions thank you for the support and + + + align:start position:0% +questions thank you for the support and +I would like to say good luck with the + + align:start position:0% +I would like to say good luck with the + + + align:start position:0% +I would like to say good luck with the +final exam and we have a hundred + + align:start position:0% +final exam and we have a hundred + + + align:start position:0% +final exam and we have a hundred +contribution on Piazza many thanks to + + align:start position:0% +contribution on Piazza many thanks to + + + align:start position:0% +contribution on Piazza many thanks to +Union who is actually doing all the hard + + align:start position:0% +Union who is actually doing all the hard + + + align:start position:0% +Union who is actually doing all the hard +work day and night and thank you very + + align:start position:0% +work day and night and thank you very + + + align:start position:0% +work day and night and thank you very +much and see you around and ID in the + + align:start position:0% +much and see you around and ID in the + + + align:start position:0% +much and see you around and ID in the +future thank you + + align:start position:0% +future thank you + + + align:start position:0% +future thank you +[Applause] + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/k2inA31Gups.txt b/k2inA31Gups.txt new file mode 100644 index 0000000000000000000000000000000000000000..0ae06a7a5f194c61f3ebfc187a677dea2b1d2a4b --- /dev/null +++ b/k2inA31Gups.txt @@ -0,0 +1,10171 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT OpenCourseWare continue to + + align:start position:0% +will help MIT OpenCourseWare continue to + + + align:start position:0% +will help MIT OpenCourseWare continue to +offer high quality educational resources + + align:start position:0% +offer high quality educational resources + + + align:start position:0% +offer high quality educational resources +for free + + align:start position:0% +for free + + + align:start position:0% +for free +to make a donation or to view additional + + align:start position:0% +to make a donation or to view additional + + + align:start position:0% +to make a donation or to view additional +materials from hundreds of MIT courses + + align:start position:0% +materials from hundreds of MIT courses + + + align:start position:0% +materials from hundreds of MIT courses +visit MIT opencourseware at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +inference again this was just an + + align:start position:0% +inference again this was just an + + + align:start position:0% +inference again this was just an +overview of what you can do in Bayesian + + align:start position:0% +overview of what you can do in Bayesian + + + align:start position:0% +overview of what you can do in Bayesian +inference and last time we started + + align:start position:0% +inference and last time we started + + + align:start position:0% +inference and last time we started +defining what's called Jeffrey's priors + + align:start position:0% +defining what's called Jeffrey's priors + + + align:start position:0% +defining what's called Jeffrey's priors +right so when you do Bayesian inference + + align:start position:0% +right so when you do Bayesian inference + + + align:start position:0% +right so when you do Bayesian inference +you have to introduce a prior on your + + align:start position:0% +you have to introduce a prior on your + + + align:start position:0% +you have to introduce a prior on your +parameter and we said that usually it's + + align:start position:0% +parameter and we said that usually it's + + + align:start position:0% +parameter and we said that usually it's +something that encodes your domain + + align:start position:0% +something that encodes your domain + + + align:start position:0% +something that encodes your domain +knowledge about where the parameter + + align:start position:0% +knowledge about where the parameter + + + align:start position:0% +knowledge about where the parameter +could be but there's also some + + align:start position:0% +could be but there's also some + + + align:start position:0% +could be but there's also some +principled way to do it if you want to + + align:start position:0% +principled way to do it if you want to + + + align:start position:0% +principled way to do it if you want to +do Bayesian inference without really + + align:start position:0% +do Bayesian inference without really + + + align:start position:0% +do Bayesian inference without really +having to think about it and for example + + align:start position:0% +having to think about it and for example + + + align:start position:0% +having to think about it and for example +one of the natural priors were those non + + align:start position:0% +one of the natural priors were those non + + + align:start position:0% +one of the natural priors were those non +informative priors right if you're on a + + align:start position:0% +informative priors right if you're on a + + + align:start position:0% +informative priors right if you're on a +compact set it's a uniform prior over + + align:start position:0% +compact set it's a uniform prior over + + + align:start position:0% +compact set it's a uniform prior over +this set if you're on an infinite set + + align:start position:0% +this set if you're on an infinite set + + + align:start position:0% +this set if you're on an infinite set +you can still think of taking the old + + align:start position:0% +you can still think of taking the old + + + align:start position:0% +you can still think of taking the old +ones prior and that's called and + + align:start position:0% +ones prior and that's called and + + + align:start position:0% +ones prior and that's called and +something probably that's always equal + + align:start position:0% +something probably that's always equal + + + align:start position:0% +something probably that's always equal +to one and that's an improper prior if + + align:start position:0% +to one and that's an improper prior if + + + align:start position:0% +to one and that's an improper prior if +you're an infinite set and/or + + align:start position:0% +you're an infinite set and/or + + + align:start position:0% +you're an infinite set and/or +proportional to one and so another + + align:start position:0% +proportional to one and so another + + + align:start position:0% +proportional to one and so another +project you can think of in the case + + align:start position:0% +project you can think of in the case + + + align:start position:0% +project you can think of in the case +where you have a Fisher information + + align:start position:0% +where you have a Fisher information + + + align:start position:0% +where you have a Fisher information +which is well defined is something + + align:start position:0% +which is well defined is something + + + align:start position:0% +which is well defined is something +called Jeffrey's prior and this prior is + + align:start position:0% +called Jeffrey's prior and this prior is + + + align:start position:0% +called Jeffrey's prior and this prior is +a prior which is proportional to square + + align:start position:0% +a prior which is proportional to square + + + align:start position:0% +a prior which is proportional to square +root of the determinant of the Fisher + + align:start position:0% +root of the determinant of the Fisher + + + align:start position:0% +root of the determinant of the Fisher +information matrix and if you just have + + align:start position:0% +information matrix and if you just have + + + align:start position:0% +information matrix and if you just have +if you're in one dimension it's + + align:start position:0% +if you're in one dimension it's + + + align:start position:0% +if you're in one dimension it's +basically proportional to square root of + + align:start position:0% +basically proportional to square root of + + + align:start position:0% +basically proportional to square root of +the Fisher information coefficient which + + align:start position:0% +the Fisher information coefficient which + + + align:start position:0% +the Fisher information coefficient which +we know for example as the synthetic + + align:start position:0% +we know for example as the synthetic + + + align:start position:0% +we know for example as the synthetic +variance at this of the maximum + + align:start position:0% +variance at this of the maximum + + + align:start position:0% +variance at this of the maximum +likelihood estimator and and it turns + + align:start position:0% +likelihood estimator and and it turns + + + align:start position:0% +likelihood estimator and and it turns +out that it's basically so square root + + align:start position:0% +out that it's basically so square root + + + align:start position:0% +out that it's basically so square root +of this thing is basically 1 over the + + align:start position:0% +of this thing is basically 1 over the + + + align:start position:0% +of this thing is basically 1 over the +standard deviation of the maximum + + align:start position:0% +standard deviation of the maximum + + + align:start position:0% +standard deviation of the maximum +likelihood estimator and so you can + + align:start position:0% +likelihood estimator and so you can + + + align:start position:0% +likelihood estimator and so you can +compute this right so you can compute + + align:start position:0% +compute this right so you can compute + + + align:start position:0% +compute this right so you can compute +for the maximum likelihood estimator we + + align:start position:0% +for the maximum likelihood estimator we + + + align:start position:0% +for the maximum likelihood estimator we +know that the variance is going to be P + + align:start position:0% +know that the variance is going to be P + + + align:start position:0% +know that the variance is going to be P +1 minus P in the in the Bernoulli + + align:start position:0% +1 minus P in the in the Bernoulli + + + align:start position:0% +1 minus P in the in the Bernoulli +statistical experiment so you get this 1 + + align:start position:0% +statistical experiment so you get this 1 + + + align:start position:0% +statistical experiment so you get this 1 +over square root of this thing + + align:start position:0% +over square root of this thing + + + align:start position:0% +over square root of this thing +and for example in the Gaussian setting + + align:start position:0% +and for example in the Gaussian setting + + + align:start position:0% +and for example in the Gaussian setting +you actually have the Fisher information + + align:start position:0% +you actually have the Fisher information + + + align:start position:0% +you actually have the Fisher information +even in the multivariate one is actually + + align:start position:0% +even in the multivariate one is actually + + + align:start position:0% +even in the multivariate one is actually +going to be something like the identity + + align:start position:0% +going to be something like the identity + + + align:start position:0% +going to be something like the identity +matrix so this is proportional to one + + align:start position:0% +matrix so this is proportional to one + + + align:start position:0% +matrix so this is proportional to one +it's the improper prior that you get in + + align:start position:0% +it's the improper prior that you get in + + + align:start position:0% +it's the improper prior that you get in +this case okay meaning that for the + + align:start position:0% +this case okay meaning that for the + + + align:start position:0% +this case okay meaning that for the +Gaussian setting no no place where you + + align:start position:0% +Gaussian setting no no place where you + + + align:start position:0% +Gaussian setting no no place where you +Center your Gaussian is actually better + + align:start position:0% +Center your Gaussian is actually better + + + align:start position:0% +Center your Gaussian is actually better +than any other alright so we basically + + align:start position:0% +than any other alright so we basically + + + align:start position:0% +than any other alright so we basically +left on this slide where we saw that + + align:start position:0% +left on this slide where we saw that + + + align:start position:0% +left on this slide where we saw that +Jeffrey's priors satisfy a repair + + align:start position:0% +Jeffrey's priors satisfy a repair + + + align:start position:0% +Jeffrey's priors satisfy a repair +motorization they're invariant by from + + align:start position:0% +motorization they're invariant by from + + + align:start position:0% +motorization they're invariant by from +transformation of your parameter which + + align:start position:0% +transformation of your parameter which + + + align:start position:0% +transformation of your parameter which +is a desirable property and and they say + + align:start position:0% +is a desirable property and and they say + + + align:start position:0% +is a desirable property and and they say +in a way it says that well if I have my + + align:start position:0% +in a way it says that well if I have my + + + align:start position:0% +in a way it says that well if I have my +prior on theta and then I certainly + + align:start position:0% +prior on theta and then I certainly + + + align:start position:0% +prior on theta and then I certainly +decide that theta is not the parameter I + + align:start position:0% +decide that theta is not the parameter I + + + align:start position:0% +decide that theta is not the parameter I +want to use to parameterize my problem + + align:start position:0% +want to use to parameterize my problem + + + align:start position:0% +want to use to parameterize my problem +actually what I want is five theta for + + align:start position:0% +actually what I want is five theta for + + + align:start position:0% +actually what I want is five theta for +thing for example as theta being the + + align:start position:0% +thing for example as theta being the + + + align:start position:0% +thing for example as theta being the +mean of a Gaussian and Phi of theta as + + align:start position:0% +mean of a Gaussian and Phi of theta as + + + align:start position:0% +mean of a Gaussian and Phi of theta as +being this mean to the cube okay this is + + align:start position:0% +being this mean to the cube okay this is + + + align:start position:0% +being this mean to the cube okay this is +a one-to-one map Phi right so for + + align:start position:0% +a one-to-one map Phi right so for + + + align:start position:0% +a one-to-one map Phi right so for +example if I want to go from theta + + align:start position:0% +example if I want to go from theta + + + align:start position:0% +example if I want to go from theta +choose theta cube and now I decide that + + align:start position:0% +choose theta cube and now I decide that + + + align:start position:0% +choose theta cube and now I decide that +this is the actual parameter that I want + + align:start position:0% +this is the actual parameter that I want + + + align:start position:0% +this is the actual parameter that I want +well then it means that on this + + align:start position:0% +well then it means that on this + + + align:start position:0% +well then it means that on this +parameter my original prior is going to + + align:start position:0% +parameter my original prior is going to + + + align:start position:0% +parameter my original prior is going to +induce another prior and here it says + + align:start position:0% +induce another prior and here it says + + + align:start position:0% +induce another prior and here it says +well this prior is actually also + + align:start position:0% +well this prior is actually also + + + align:start position:0% +well this prior is actually also +Jeffrey's prior okay so it's essentially + + align:start position:0% +Jeffrey's prior okay so it's essentially + + + align:start position:0% +Jeffrey's prior okay so it's essentially +telling you that for this new + + align:start position:0% +telling you that for this new + + + align:start position:0% +telling you that for this new +parameterization if you take Jeffrey's + + align:start position:0% +parameterization if you take Jeffrey's + + + align:start position:0% +parameterization if you take Jeffrey's +prior then you actually go back to + + align:start position:0% +prior then you actually go back to + + + align:start position:0% +prior then you actually go back to +having exactly something that's of the + + align:start position:0% +having exactly something that's of the + + + align:start position:0% +having exactly something that's of the +form skirt of determinate of the Fisher + + align:start position:0% +form skirt of determinate of the Fisher + + + align:start position:0% +form skirt of determinate of the Fisher +information but this thing with respect + + align:start position:0% +information but this thing with respect + + + align:start position:0% +information but this thing with respect +to your new parameter ization all right + + align:start position:0% +to your new parameter ization all right + + + align:start position:0% +to your new parameter ization all right +and so why is this true well it's just + + align:start position:0% +and so why is this true well it's just + + + align:start position:0% +and so why is this true well it's just +this change of variable theorem right so + + align:start position:0% +this change of variable theorem right so + + + align:start position:0% +this change of variable theorem right so +it's essentially telling you that if you + + align:start position:0% +it's essentially telling you that if you + + + align:start position:0% +it's essentially telling you that if you +call let's call P well let's call P + + align:start position:0% +call let's call P well let's call P + + + align:start position:0% +call let's call P well let's call P +tilde of Geeta prior over ETA and you + + align:start position:0% +tilde of Geeta prior over ETA and you + + + align:start position:0% +tilde of Geeta prior over ETA and you +have PI's of theta as the prior of theta + + align:start position:0% +have PI's of theta as the prior of theta + + + align:start position:0% +have PI's of theta as the prior of theta +then just by since ETA is of the form + + align:start position:0% +then just by since ETA is of the form + + + align:start position:0% +then just by since ETA is of the form +Phi of theta just by change of variable + + align:start position:0% + + + + align:start position:0% + +right so that's essentially a + + align:start position:0% +right so that's essentially a + + + align:start position:0% +right so that's essentially a +probability result it says that PI tilde + + align:start position:0% +probability result it says that PI tilde + + + align:start position:0% +probability result it says that PI tilde +of eta is equal to PI of ETA times D PI + + align:start position:0% +of eta is equal to PI of ETA times D PI + + + align:start position:0% +of eta is equal to PI of ETA times D PI +of theta times D theta over D ETA and + + align:start position:0% + + + + align:start position:0% + +sorry is that the one should I'm gonna + + align:start position:0% +sorry is that the one should I'm gonna + + + align:start position:0% +sorry is that the one should I'm gonna +have to write it because I always forget + + align:start position:0% +have to write it because I always forget + + + align:start position:0% +have to write it because I always forget +this so if I take a function okay so + + align:start position:0% +this so if I take a function okay so + + + align:start position:0% +this so if I take a function okay so +what I want is to check + + align:start position:0% + + + + align:start position:0% + +okay okay so I want a function of ETA + + align:start position:0% +okay okay so I want a function of ETA + + + align:start position:0% +okay okay so I want a function of ETA +that I can put here and what I know is + + align:start position:0% +that I can put here and what I know is + + + align:start position:0% +that I can put here and what I know is +that this is H of Phi of theta + + align:start position:0% +that this is H of Phi of theta + + + align:start position:0% +that this is H of Phi of theta +all right so sorry eta is five data + + align:start position:0% +all right so sorry eta is five data + + + align:start position:0% +all right so sorry eta is five data +right yeah so what I'm gonna do is I'm + + align:start position:0% +right yeah so what I'm gonna do is I'm + + + align:start position:0% +right yeah so what I'm gonna do is I'm +gonna do the change of variable theta is + + align:start position:0% +gonna do the change of variable theta is + + + align:start position:0% +gonna do the change of variable theta is +Phi inverse so eta is Phi of theta which + + align:start position:0% +Phi inverse so eta is Phi of theta which + + + align:start position:0% +Phi inverse so eta is Phi of theta which +means that D eta is equal to D twelve to + + align:start position:0% +means that D eta is equal to D twelve to + + + align:start position:0% +means that D eta is equal to D twelve to +Phi prime of theta D theta so what I'm + + align:start position:0% +Phi prime of theta D theta so what I'm + + + align:start position:0% +Phi prime of theta D theta so what I'm +gonna write this I'm gonna get integral + + align:start position:0% +gonna write this I'm gonna get integral + + + align:start position:0% +gonna write this I'm gonna get integral +of H actually me write this as a + + align:start position:0% +of H actually me write this as a + + + align:start position:0% +of H actually me write this as a +comfortable writing this as e with + + align:start position:0% +comfortable writing this as e with + + + align:start position:0% +comfortable writing this as e with +respect to a tie of HIV time okay so + + align:start position:0% +respect to a tie of HIV time okay so + + + align:start position:0% +respect to a tie of HIV time okay so +that's just it according to being drawn + + align:start position:0% +that's just it according to being drawn + + + align:start position:0% +that's just it according to being drawn +from the prior and I want to write this + + align:start position:0% +from the prior and I want to write this + + + align:start position:0% +from the prior and I want to write this +as the integral of H of ETA times some + + align:start position:0% +as the integral of H of ETA times some + + + align:start position:0% +as the integral of H of ETA times some +function right so this is the integral + + align:start position:0% +function right so this is the integral + + + align:start position:0% +function right so this is the integral +of H of Phi of theta phi of theta now + + align:start position:0% +of H of Phi of theta phi of theta now + + + align:start position:0% +of H of Phi of theta phi of theta now +I'm gonna do my change of variable so + + align:start position:0% +I'm gonna do my change of variable so + + + align:start position:0% +I'm gonna do my change of variable so +this is gonna be the integral of H of + + align:start position:0% +this is gonna be the integral of H of + + + align:start position:0% +this is gonna be the integral of H of +theta and then Phi of Phi Theta is and + + align:start position:0% +theta and then Phi of Phi Theta is and + + + align:start position:0% +theta and then Phi of Phi Theta is and +then prime of theta okay and so what is + + align:start position:0% +then prime of theta okay and so what is + + + align:start position:0% +then prime of theta okay and so what is +pi of Phi Theta so this thing is + + align:start position:0% +pi of Phi Theta so this thing is + + + align:start position:0% +pi of Phi Theta so this thing is +proportional so we're in say dimension + + align:start position:0% +proportional so we're in say dimension + + + align:start position:0% +proportional so we're in say dimension +one so it's proportional of square root + + align:start position:0% +one so it's proportional of square root + + + align:start position:0% +one so it's proportional of square root +of the Fisher information and the Fisher + + align:start position:0% +of the Fisher information and the Fisher + + + align:start position:0% +of the Fisher information and the Fisher +information we know is the expectation + + align:start position:0% +information we know is the expectation + + + align:start position:0% +information we know is the expectation +of the square of the derivative of the + + align:start position:0% +of the square of the derivative of the + + + align:start position:0% +of the square of the derivative of the +log likelihood right so this is square + + align:start position:0% +log likelihood right so this is square + + + align:start position:0% +log likelihood right so this is square +root of the expectation + + align:start position:0% +root of the expectation + + + align:start position:0% +root of the expectation +d over the theta of log of well now I + + align:start position:0% +d over the theta of log of well now I + + + align:start position:0% +d over the theta of log of well now I +need the density well let's just call it + + align:start position:0% +need the density well let's just call it + + + align:start position:0% +need the density well let's just call it +log let's call it L of theta and I want + + align:start position:0% +log let's call it L of theta and I want + + + align:start position:0% +log let's call it L of theta and I want +this to be taken at Phi inverse beta + + align:start position:0% +this to be taken at Phi inverse beta + + + align:start position:0% +this to be taken at Phi inverse beta +squared and then what I pick up is the + + align:start position:0% +squared and then what I pick up is the + + + align:start position:0% +squared and then what I pick up is the +so I'm going to put everything under the + + align:start position:0% +so I'm going to put everything under the + + + align:start position:0% +so I'm going to put everything under the +square so I get Phi prime of theta + + align:start position:0% +square so I get Phi prime of theta + + + align:start position:0% +square so I get Phi prime of theta +squared D theta ok so now I have the + + align:start position:0% +squared D theta ok so now I have the + + + align:start position:0% +squared D theta ok so now I have the +expectation of a squared this does not + + align:start position:0% +expectation of a squared this does not + + + align:start position:0% +expectation of a squared this does not +depend so this is sorry this is L of + + align:start position:0% +depend so this is sorry this is L of + + + align:start position:0% +depend so this is sorry this is L of +theta this is the expectation of L of + + align:start position:0% +theta this is the expectation of L of + + + align:start position:0% +theta this is the expectation of L of +theta and X right that's for some + + align:start position:0% +theta and X right that's for some + + + align:start position:0% +theta and X right that's for some +variable and the expectation here is + + align:start position:0% +variable and the expectation here is + + + align:start position:0% +variable and the expectation here is +with respect to X that's just the + + align:start position:0% +with respect to X that's just the + + + align:start position:0% +with respect to X that's just the +definition of the feature information so + + align:start position:0% +definition of the feature information so + + + align:start position:0% +definition of the feature information so +now I'm going to squeeze this guy into + + align:start position:0% +now I'm going to squeeze this guy into + + + align:start position:0% +now I'm going to squeeze this guy into +the expectation it does not depend on X + + align:start position:0% +the expectation it does not depend on X + + + align:start position:0% +the expectation it does not depend on X +it just acts as a constant and so what I + + align:start position:0% +it just acts as a constant and so what I + + + align:start position:0% +it just acts as a constant and so what I +have now is that this is actually + + align:start position:0% +have now is that this is actually + + + align:start position:0% +have now is that this is actually +proportional to the integral of H ETA + + align:start position:0% +proportional to the integral of H ETA + + + align:start position:0% +proportional to the integral of H ETA +times the square root of the expectation + + align:start position:0% +times the square root of the expectation + + + align:start position:0% +times the square root of the expectation +with respect to X of what well here I + + align:start position:0% +with respect to X of what well here I + + + align:start position:0% +with respect to X of what well here I +have D over D theta of log of theta and + + align:start position:0% +have D over D theta of log of theta and + + + align:start position:0% +have D over D theta of log of theta and +here this guy is really D ETA over D + + align:start position:0% +here this guy is really D ETA over D + + + align:start position:0% +here this guy is really D ETA over D +theta right ok so now what I'm really + + align:start position:0% +theta right ok so now what I'm really + + + align:start position:0% +theta right ok so now what I'm really +left by so I get D over D theta times + + align:start position:0% +left by so I get D over D theta times + + + align:start position:0% +left by so I get D over D theta times +this sorry times D theta over D ETA + + align:start position:0% + + + + align:start position:0% + +so that's just D over D ETA of log of + + align:start position:0% +so that's just D over D ETA of log of + + + align:start position:0% +so that's just D over D ETA of log of +ETA + + align:start position:0% +ETA + + + align:start position:0% +ETA +X + + align:start position:0% + + + + align:start position:0% + +and then this guy is now becoming DITA + + align:start position:0% +and then this guy is now becoming DITA + + + align:start position:0% +and then this guy is now becoming DITA +right okay so this was a mess this is a + + align:start position:0% +right okay so this was a mess this is a + + + align:start position:0% +right okay so this was a mess this is a +complete mess because they actually want + + align:start position:0% +complete mess because they actually want + + + align:start position:0% +complete mess because they actually want +to use fire should not actually + + align:start position:0% +to use fire should not actually + + + align:start position:0% +to use fire should not actually +introduce fire at all I should just talk + + align:start position:0% +introduce fire at all I should just talk + + + align:start position:0% +introduce fire at all I should just talk +about overdue data type of things and + + align:start position:0% +about overdue data type of things and + + + align:start position:0% +about overdue data type of things and +then that would actually make my life so + + align:start position:0% +then that would actually make my life so + + + align:start position:0% +then that would actually make my life so +much easier + + align:start position:0% +much easier + + + align:start position:0% +much easier +okay I'm not going to spend more time on + + align:start position:0% +okay I'm not going to spend more time on + + + align:start position:0% +okay I'm not going to spend more time on +this this is really just the idea right + + align:start position:0% +this this is really just the idea right + + + align:start position:0% +this this is really just the idea right +you have square root of a square in + + align:start position:0% +you have square root of a square in + + + align:start position:0% +you have square root of a square in +there and then when you do your change + + align:start position:0% +there and then when you do your change + + + align:start position:0% +there and then when you do your change +your variable you just pick up a square + + align:start position:0% +your variable you just pick up a square + + + align:start position:0% +your variable you just pick up a square +you just pick up something and here and + + align:start position:0% +you just pick up something and here and + + + align:start position:0% +you just pick up something and here and +so you just move this thing in there you + + align:start position:0% +so you just move this thing in there you + + + align:start position:0% +so you just move this thing in there you +get a square it goes inside the square + + align:start position:0% +get a square it goes inside the square + + + align:start position:0% +get a square it goes inside the square +and so your derivative of the log + + align:start position:0% +and so your derivative of the log + + + align:start position:0% +and so your derivative of the log +likelihood with the respective theta + + align:start position:0% +likelihood with the respective theta + + + align:start position:0% +likelihood with the respective theta +becomes a derivative of the likelihood + + align:start position:0% +becomes a derivative of the likelihood + + + align:start position:0% +becomes a derivative of the likelihood +respect to theta and that's just that's + + align:start position:0% +respect to theta and that's just that's + + + align:start position:0% +respect to theta and that's just that's +the only thing that's happening here + + align:start position:0% +the only thing that's happening here + + + align:start position:0% +the only thing that's happening here +I'm just being super sloppy for some + + align:start position:0% +I'm just being super sloppy for some + + + align:start position:0% +I'm just being super sloppy for some +reason okay and then of course now what + + align:start position:0% +reason okay and then of course now what + + + align:start position:0% +reason okay and then of course now what +you're left with is that this is really + + align:start position:0% +you're left with is that this is really + + + align:start position:0% +you're left with is that this is really +just proportional well this is actually + + align:start position:0% +just proportional well this is actually + + + align:start position:0% +just proportional well this is actually +equal everything is proportional but + + align:start position:0% +equal everything is proportional but + + + align:start position:0% +equal everything is proportional but +this is equal to the Fisher information + + align:start position:0% +this is equal to the Fisher information + + + align:start position:0% +this is equal to the Fisher information +tilde with respect to Chiquita now right + + align:start position:0% +tilde with respect to Chiquita now right + + + align:start position:0% +tilde with respect to Chiquita now right +you're doing this with respect to ETA + + align:start position:0% +you're doing this with respect to ETA + + + align:start position:0% +you're doing this with respect to ETA +and so that's a new that's your new + + align:start position:0% +and so that's a new that's your new + + + align:start position:0% +and so that's a new that's your new +prior with respect to theta okay so one + + align:start position:0% +prior with respect to theta okay so one + + + align:start position:0% +prior with respect to theta okay so one +thing that you want to do once you have + + align:start position:0% +thing that you want to do once you have + + + align:start position:0% +thing that you want to do once you have +so remember when you actually compute + + align:start position:0% +so remember when you actually compute + + + align:start position:0% +so remember when you actually compute +your your posterior right rather than + + align:start position:0% +your your posterior right rather than + + + align:start position:0% +your your posterior right rather than +having so you start with a prior and you + + align:start position:0% +having so you start with a prior and you + + + align:start position:0% +having so you start with a prior and you +have some observations let's say x1 to + + align:start position:0% +have some observations let's say x1 to + + + align:start position:0% +have some observations let's say x1 to +xn when you do Bayesian inference rather + + align:start position:0% +xn when you do Bayesian inference rather + + + align:start position:0% +xn when you do Bayesian inference rather +than spitting out just some theta hat + + align:start position:0% +than spitting out just some theta hat + + + align:start position:0% +than spitting out just some theta hat +which is an estimator for theta you + + align:start position:0% +which is an estimator for theta you + + + align:start position:0% +which is an estimator for theta you +actually spit out an entire posterior + + align:start position:0% +actually spit out an entire posterior + + + align:start position:0% +actually spit out an entire posterior +distribution PI of theta given X 1 xn ok + + align:start position:0% +distribution PI of theta given X 1 xn ok + + + align:start position:0% +distribution PI of theta given X 1 xn ok +so there's an entire distribution on the + + align:start position:0% +so there's an entire distribution on the + + + align:start position:0% +so there's an entire distribution on the +candidates theta and you can actually + + align:start position:0% +candidates theta and you can actually + + + align:start position:0% +candidates theta and you can actually +use this to perform inference rather + + align:start position:0% +use this to perform inference rather + + + align:start position:0% +use this to perform inference rather +than just having one number okay and so + + align:start position:0% +than just having one number okay and so + + + align:start position:0% +than just having one number okay and so +you could actually build confidence + + align:start position:0% +you could actually build confidence + + + align:start position:0% +you could actually build confidence +regions from this thing okay and so a a + + align:start position:0% +regions from this thing okay and so a a + + + align:start position:0% +regions from this thing okay and so a a +Bayesian + + align:start position:0% +Bayesian + + + align:start position:0% +Bayesian +confidence interval so if your set of + + align:start position:0% +confidence interval so if your set of + + + align:start position:0% +confidence interval so if your set of +parameters is included in the real line + + align:start position:0% +parameters is included in the real line + + + align:start position:0% +parameters is included in the real line +then you can actually it's not even it's + + align:start position:0% +then you can actually it's not even it's + + + align:start position:0% +then you can actually it's not even it's +not even guaranteed to be to be an + + align:start position:0% +not even guaranteed to be to be an + + + align:start position:0% +not even guaranteed to be to be an +interval so let me call it a confidence + + align:start position:0% +interval so let me call it a confidence + + + align:start position:0% +interval so let me call it a confidence +region so a bayesian confidence region + + align:start position:0% + + + + align:start position:0% + +okay so it's just a random subspace so + + align:start position:0% +okay so it's just a random subspace so + + + align:start position:0% +okay so it's just a random subspace so +let's call it R is included in theta and + + align:start position:0% +let's call it R is included in theta and + + + align:start position:0% +let's call it R is included in theta and +when you had the deterministic one we + + align:start position:0% +when you had the deterministic one we + + + align:start position:0% +when you had the deterministic one we +had a definition which was with respect + + align:start position:0% +had a definition which was with respect + + + align:start position:0% +had a definition which was with respect +to the randomness of the data right + + align:start position:0% +to the randomness of the data right + + + align:start position:0% +to the randomness of the data right +that's how you actually had a random + + align:start position:0% +that's how you actually had a random + + + align:start position:0% +that's how you actually had a random +subset you had a random confidence + + align:start position:0% +subset you had a random confidence + + + align:start position:0% +subset you had a random confidence +interval here it's actually conditioned + + align:start position:0% +interval here it's actually conditioned + + + align:start position:0% +interval here it's actually conditioned +on the data but with respect to the + + align:start position:0% +on the data but with respect to the + + + align:start position:0% +on the data but with respect to the +randomness that you actually get from + + align:start position:0% +randomness that you actually get from + + + align:start position:0% +randomness that you actually get from +your posterior distribution + + align:start position:0% +your posterior distribution + + + align:start position:0% +your posterior distribution +okay so such that the probability that + + align:start position:0% +okay so such that the probability that + + + align:start position:0% +okay so such that the probability that +your theta belongs to this confidence + + align:start position:0% +your theta belongs to this confidence + + + align:start position:0% +your theta belongs to this confidence +region given X 1 xn and say at least 1 + + align:start position:0% +region given X 1 xn and say at least 1 + + + align:start position:0% +region given X 1 xn and say at least 1 +minus alpha let's just take it equal to + + align:start position:0% +minus alpha let's just take it equal to + + + align:start position:0% +minus alpha let's just take it equal to +1 minus alpha okay so that's a + + align:start position:0% +1 minus alpha okay so that's a + + + align:start position:0% +1 minus alpha okay so that's a +confidence region at lab at level 1 + + align:start position:0% +confidence region at lab at level 1 + + + align:start position:0% +confidence region at lab at level 1 +minus alpha okay so that's one way so + + align:start position:0% +minus alpha okay so that's one way so + + + align:start position:0% +minus alpha okay so that's one way so +why would you actually I when I actually + + align:start position:0% +why would you actually I when I actually + + + align:start position:0% +why would you actually I when I actually +implement Bayesian inference I'm + + align:start position:0% +implement Bayesian inference I'm + + + align:start position:0% +implement Bayesian inference I'm +actually spinning out an entire + + align:start position:0% +actually spinning out an entire + + + align:start position:0% +actually spinning out an entire +distribution I need to summarize this + + align:start position:0% +distribution I need to summarize this + + + align:start position:0% +distribution I need to summarize this +this thing to communicate it right I + + align:start position:0% +this thing to communicate it right I + + + align:start position:0% +this thing to communicate it right I +cannot just say this is this entire + + align:start position:0% +cannot just say this is this entire + + + align:start position:0% +cannot just say this is this entire +function I want to know where are the + + align:start position:0% +function I want to know where are the + + + align:start position:0% +function I want to know where are the +regions of high probability where my + + align:start position:0% +regions of high probability where my + + + align:start position:0% +regions of high probability where my +parameter is supposed to be and so here + + align:start position:0% +parameter is supposed to be and so here + + + align:start position:0% +parameter is supposed to be and so here +when I have this thing what I actually + + align:start position:0% +when I have this thing what I actually + + + align:start position:0% +when I have this thing what I actually +want to have is something that says well + + align:start position:0% +want to have is something that says well + + + align:start position:0% +want to have is something that says well +I want to summarize this thing into some + + align:start position:0% +I want to summarize this thing into some + + + align:start position:0% +I want to summarize this thing into some +subset of the real line in which I'm + + align:start position:0% +subset of the real line in which I'm + + + align:start position:0% +subset of the real line in which I'm +sure that the area under the curve here + + align:start position:0% +sure that the area under the curve here + + + align:start position:0% +sure that the area under the curve here +of my posterior is actually 1 minus + + align:start position:0% +of my posterior is actually 1 minus + + + align:start position:0% +of my posterior is actually 1 minus +alpha and there's many ways to do this + + align:start position:0% +alpha and there's many ways to do this + + + align:start position:0% +alpha and there's many ways to do this +right so one way to do this + + align:start position:0% + + + + align:start position:0% + +is to look at level sets and so rather + + align:start position:0% +is to look at level sets and so rather + + + align:start position:0% +is to look at level sets and so rather +than actually so let's say my my + + align:start position:0% +than actually so let's say my my + + + align:start position:0% +than actually so let's say my my +posterior looks like this I know for + + align:start position:0% +posterior looks like this I know for + + + align:start position:0% +posterior looks like this I know for +example if I have a Gaussian + + align:start position:0% +example if I have a Gaussian + + + align:start position:0% +example if I have a Gaussian +distribution I can actually take my + + align:start position:0% +distribution I can actually take my + + + align:start position:0% +distribution I can actually take my +posterior to be my posterior is actually + + align:start position:0% +posterior to be my posterior is actually + + + align:start position:0% +posterior to be my posterior is actually +going to be Gaussian and what I can do + + align:start position:0% +going to be Gaussian and what I can do + + + align:start position:0% +going to be Gaussian and what I can do +is to try to cut it here on the y axis + + align:start position:0% +is to try to cut it here on the y axis + + + align:start position:0% +is to try to cut it here on the y axis +so that now the area under the curve + + align:start position:0% +so that now the area under the curve + + + align:start position:0% +so that now the area under the curve +when I cut here is actually 1 minus + + align:start position:0% +when I cut here is actually 1 minus + + + align:start position:0% +when I cut here is actually 1 minus +alpha okay so I have some threshold tau + + align:start position:0% +alpha okay so I have some threshold tau + + + align:start position:0% +alpha okay so I have some threshold tau +if tau goes to plus infinity then I'm + + align:start position:0% +if tau goes to plus infinity then I'm + + + align:start position:0% +if tau goes to plus infinity then I'm +gonna have that this area under the + + align:start position:0% +gonna have that this area under the + + + align:start position:0% +gonna have that this area under the +curve here is going to + + align:start position:0% + + + + align:start position:0% + +well no no so the air end of the curve + + align:start position:0% +well no no so the air end of the curve + + + align:start position:0% +well no no so the air end of the curve +when Tao is going to plus infinity think + + align:start position:0% +when Tao is going to plus infinity think + + + align:start position:0% +when Tao is going to plus infinity think +of the small the when Tao is just like + + align:start position:0% +of the small the when Tao is just like + + + align:start position:0% +of the small the when Tao is just like +right here so this is actually going to + + align:start position:0% +right here so this is actually going to + + + align:start position:0% +right here so this is actually going to +zero right and so I start here and then + + align:start position:0% +zero right and so I start here and then + + + align:start position:0% +zero right and so I start here and then +I start going down and down and down and + + align:start position:0% +I start going down and down and down and + + + align:start position:0% +I start going down and down and down and +down until I actually get something + + align:start position:0% +down until I actually get something + + + align:start position:0% +down until I actually get something +which is going down to one plus alpha + + align:start position:0% +which is going down to one plus alpha + + + align:start position:0% +which is going down to one plus alpha +but if tau is going down to zero then my + + align:start position:0% +but if tau is going down to zero then my + + + align:start position:0% +but if tau is going down to zero then my +area under the curve is going to if tau + + align:start position:0% +area under the curve is going to if tau + + + align:start position:0% +area under the curve is going to if tau +is here I'm cutting nowhere and so I'm + + align:start position:0% +is here I'm cutting nowhere and so I'm + + + align:start position:0% +is here I'm cutting nowhere and so I'm +getting one right agree + + align:start position:0% +getting one right agree + + + align:start position:0% +getting one right agree +think of when tau is very close to zero + + align:start position:0% +think of when tau is very close to zero + + + align:start position:0% +think of when tau is very close to zero +I'm cutting as very far here and so I'm + + align:start position:0% +I'm cutting as very far here and so I'm + + + align:start position:0% +I'm cutting as very far here and so I'm +getting some area under the curve which + + align:start position:0% +getting some area under the curve which + + + align:start position:0% +getting some area under the curve which +is almost everything and so it's going + + align:start position:0% +is almost everything and so it's going + + + align:start position:0% +is almost everything and so it's going +to one iced out going down to zero yeah + + align:start position:0% + + + + align:start position:0% + +no it does not I mean so this is a + + align:start position:0% +no it does not I mean so this is a + + + align:start position:0% +no it does not I mean so this is a +picture this picture so those two things + + align:start position:0% +picture this picture so those two things + + + align:start position:0% +picture this picture so those two things +work for all of them right but when you + + align:start position:0% +work for all of them right but when you + + + align:start position:0% +work for all of them right but when you +have a bino model actually this is + + align:start position:0% +have a bino model actually this is + + + align:start position:0% +have a bino model actually this is +actually when things start to become + + align:start position:0% +actually when things start to become + + + align:start position:0% +actually when things start to become +interesting right so when we had when we + + align:start position:0% +interesting right so when we had when we + + + align:start position:0% +interesting right so when we had when we +built a frequentist confidence interval + + align:start position:0% +built a frequentist confidence interval + + + align:start position:0% +built a frequentist confidence interval +it was always of the form x-bar plus or + + align:start position:0% +it was always of the form x-bar plus or + + + align:start position:0% +it was always of the form x-bar plus or +minus something but now if I start to + + align:start position:0% +minus something but now if I start to + + + align:start position:0% +minus something but now if I start to +have a posterior that looks like this + + align:start position:0% +have a posterior that looks like this + + + align:start position:0% +have a posterior that looks like this +I'm gonna start cutting off I'm gonna + + align:start position:0% +I'm gonna start cutting off I'm gonna + + + align:start position:0% +I'm gonna start cutting off I'm gonna +have to I mean my confidence region is + + align:start position:0% +have to I mean my confidence region is + + + align:start position:0% +have to I mean my confidence region is +going to be the union of those two + + align:start position:0% +going to be the union of those two + + + align:start position:0% +going to be the union of those two +things right and it really reflects the + + align:start position:0% +things right and it really reflects the + + + align:start position:0% +things right and it really reflects the +fact that there's this bimodal thing + + align:start position:0% +fact that there's this bimodal thing + + + align:start position:0% +fact that there's this bimodal thing +it's gonna say well with higher + + align:start position:0% +it's gonna say well with higher + + + align:start position:0% +it's gonna say well with higher +probability I'm actually going to be + + align:start position:0% +probability I'm actually going to be + + + align:start position:0% +probability I'm actually going to be +either here or here now the meaning here + + align:start position:0% +either here or here now the meaning here + + + align:start position:0% +either here or here now the meaning here +of a bayesian Conference region and a + + align:start position:0% +of a bayesian Conference region and a + + + align:start position:0% +of a bayesian Conference region and a +confidence interval or completely + + align:start position:0% +confidence interval or completely + + + align:start position:0% +confidence interval or completely +distinct notions right + + align:start position:0% +distinct notions right + + + align:start position:0% +distinct notions right +and it's actually I'm gonna work out an + + align:start position:0% +and it's actually I'm gonna work out an + + + align:start position:0% +and it's actually I'm gonna work out an +example with you so that we can actually + + align:start position:0% +example with you so that we can actually + + + align:start position:0% +example with you so that we can actually +see that sometimes I mean both of them + + align:start position:0% +see that sometimes I mean both of them + + + align:start position:0% +see that sometimes I mean both of them +actually you can come up with some crazy + + align:start position:0% +actually you can come up with some crazy + + + align:start position:0% +actually you can come up with some crazy +paradoxes so since we don't have that + + align:start position:0% +paradoxes so since we don't have that + + + align:start position:0% +paradoxes so since we don't have that +much time I will actually talk to you + + align:start position:0% +much time I will actually talk to you + + + align:start position:0% +much time I will actually talk to you +about why in some instances it's + + align:start position:0% +about why in some instances it's + + + align:start position:0% +about why in some instances it's +actually a good idea to think of + + align:start position:0% +actually a good idea to think of + + + align:start position:0% +actually a good idea to think of +Bayesian confidence intervals rather + + align:start position:0% +Bayesian confidence intervals rather + + + align:start position:0% +Bayesian confidence intervals rather +than frequentist ones so before I go + + align:start position:0% +than frequentist ones so before I go + + + align:start position:0% +than frequentist ones so before I go +into more details about what those + + align:start position:0% +into more details about what those + + + align:start position:0% +into more details about what those +Bayesian confidence intervals are let's + + align:start position:0% +Bayesian confidence intervals are let's + + + align:start position:0% +Bayesian confidence intervals are let's +remind ourselves what is it + + align:start position:0% +remind ourselves what is it + + + align:start position:0% +remind ourselves what is it +mean do you have a frequentist + + align:start position:0% +mean do you have a frequentist + + + align:start position:0% +mean do you have a frequentist +confidence interval right so okay so + + align:start position:0% +confidence interval right so okay so + + + align:start position:0% +confidence interval right so okay so +when I have a frequentist point + + align:start position:0% +when I have a frequentist point + + + align:start position:0% +when I have a frequentist point +confidence interval let's say something + + align:start position:0% +confidence interval let's say something + + + align:start position:0% +confidence interval let's say something +like X bar and it's minus 1.96 the Sigma + + align:start position:0% +like X bar and it's minus 1.96 the Sigma + + + align:start position:0% +like X bar and it's minus 1.96 the Sigma +over root N and X Bar n plus 1 point 9 6 + + align:start position:0% +over root N and X Bar n plus 1 point 9 6 + + + align:start position:0% +over root N and X Bar n plus 1 point 9 6 +Sigma over ribbon right so that's the + + align:start position:0% +Sigma over ribbon right so that's the + + + align:start position:0% +Sigma over ribbon right so that's the +confidence interval that you get for the + + align:start position:0% +confidence interval that you get for the + + + align:start position:0% +confidence interval that you get for the +mean of some Gaussian with known + + align:start position:0% +mean of some Gaussian with known + + + align:start position:0% +mean of some Gaussian with known +variants to be equal to Sigma square ok + + align:start position:0% +variants to be equal to Sigma square ok + + + align:start position:0% +variants to be equal to Sigma square ok +so what we know is that the meaning of + + align:start position:0% +so what we know is that the meaning of + + + align:start position:0% +so what we know is that the meaning of +this is the probability that theta + + align:start position:0% +this is the probability that theta + + + align:start position:0% +this is the probability that theta +belongs to this is equal to 95 percent + + align:start position:0% +belongs to this is equal to 95 percent + + + align:start position:0% +belongs to this is equal to 95 percent +right and this more general you can + + align:start position:0% +right and this more general you can + + + align:start position:0% +right and this more general you can +think of being Q alpha over 2 and when + + align:start position:0% +think of being Q alpha over 2 and when + + + align:start position:0% +think of being Q alpha over 2 and when +you're gonna get is 1 minus alpha here + + align:start position:0% +you're gonna get is 1 minus alpha here + + + align:start position:0% +you're gonna get is 1 minus alpha here +okay so what does it mean here well it + + align:start position:0% +okay so what does it mean here well it + + + align:start position:0% +okay so what does it mean here well it +means it looks very much like what we + + align:start position:0% +means it looks very much like what we + + + align:start position:0% +means it looks very much like what we +have here except that we're not + + align:start position:0% +have here except that we're not + + + align:start position:0% +have here except that we're not +conditioning on X 1 xn and we should not + + align:start position:0% +conditioning on X 1 xn and we should not + + + align:start position:0% +conditioning on X 1 xn and we should not +because there was a question like that + + align:start position:0% +because there was a question like that + + + align:start position:0% +because there was a question like that +in the midterm if I condition on X 1 X + + align:start position:0% +in the midterm if I condition on X 1 X + + + align:start position:0% +in the midterm if I condition on X 1 X +and this probability is either 0 or 1 + + align:start position:0% +and this probability is either 0 or 1 + + + align:start position:0% +and this probability is either 0 or 1 +okay because once I condition so here + + align:start position:0% +okay because once I condition so here + + + align:start position:0% +okay because once I condition so here +this probability actually here is with + + align:start position:0% +this probability actually here is with + + + align:start position:0% +this probability actually here is with +respect to the randomness in X 1 xn so + + align:start position:0% +respect to the randomness in X 1 xn so + + + align:start position:0% +respect to the randomness in X 1 xn so +if I condition let's call this thing our + + align:start position:0% +if I condition let's call this thing our + + + align:start position:0% +if I condition let's call this thing our +frack for frequent test well given X 1 + + align:start position:0% +frack for frequent test well given X 1 + + + align:start position:0% +frack for frequent test well given X 1 +xn and actually at only 2 nu X 1 xn + + align:start position:0% +xn and actually at only 2 nu X 1 xn + + + align:start position:0% +xn and actually at only 2 nu X 1 xn +really what I need to know is what xn + + align:start position:0% +really what I need to know is what xn + + + align:start position:0% +really what I need to know is what xn +bar is well this thing now is what it's + + align:start position:0% +bar is well this thing now is what it's + + + align:start position:0% +bar is well this thing now is what it's +1 if theta is in R and it's 0 if theta + + align:start position:0% +1 if theta is in R and it's 0 if theta + + + align:start position:0% +1 if theta is in R and it's 0 if theta +is not in our right that's all there is + + align:start position:0% +is not in our right that's all there is + + + align:start position:0% +is not in our right that's all there is +this is a deterministic confidence + + align:start position:0% +this is a deterministic confidence + + + align:start position:0% +this is a deterministic confidence +interval once I condition on X M 1 X n + + align:start position:0% +interval once I condition on X M 1 X n + + + align:start position:0% +interval once I condition on X M 1 X n +so I have a number the average is maybe + + align:start position:0% +so I have a number the average is maybe + + + align:start position:0% +so I have a number the average is maybe +3 and so I get 3 either theta is between + + align:start position:0% +3 and so I get 3 either theta is between + + + align:start position:0% +3 and so I get 3 either theta is between +3 minus 0.5 or in 3 point plus 0.5 or + + align:start position:0% +3 minus 0.5 or in 3 point plus 0.5 or + + + align:start position:0% +3 minus 0.5 or in 3 point plus 0.5 or +it's not and + + align:start position:0% +it's not and + + + align:start position:0% +it's not and +there's basically I mean I read it as + + align:start position:0% +there's basically I mean I read it as + + + align:start position:0% +there's basically I mean I read it as +probability but it's really not a + + align:start position:0% +probability but it's really not a + + + align:start position:0% +probability but it's really not a +probabilistic thing minutes either is + + align:start position:0% +probabilistic thing minutes either is + + + align:start position:0% +probabilistic thing minutes either is +sure or not agreed so what does it mean + + align:start position:0% +sure or not agreed so what does it mean + + + align:start position:0% +sure or not agreed so what does it mean +to have a frequentist confidence + + align:start position:0% +to have a frequentist confidence + + + align:start position:0% +to have a frequentist confidence +interval and means that if I were so and + + align:start position:0% +interval and means that if I were so and + + + align:start position:0% +interval and means that if I were so and +here it was where the word frequentist + + align:start position:0% +here it was where the word frequentist + + + align:start position:0% +here it was where the word frequentist +comes from it says that if I repeat this + + align:start position:0% +comes from it says that if I repeat this + + + align:start position:0% +comes from it says that if I repeat this +experiment over and over meaning that on + + align:start position:0% +experiment over and over meaning that on + + + align:start position:0% +experiment over and over meaning that on +Monday I could like the sample of size N + + align:start position:0% +Monday I could like the sample of size N + + + align:start position:0% +Monday I could like the sample of size N +and I build a confidence interval and + + align:start position:0% +and I build a confidence interval and + + + align:start position:0% +and I build a confidence interval and +then on Tuesday I collect another sample + + align:start position:0% +then on Tuesday I collect another sample + + + align:start position:0% +then on Tuesday I collect another sample +of size N and I build a confidence + + align:start position:0% +of size N and I build a confidence + + + align:start position:0% +of size N and I build a confidence +interval and on Wednesday I do this + + align:start position:0% +interval and on Wednesday I do this + + + align:start position:0% +interval and on Wednesday I do this +again and again what's gonna happen is + + align:start position:0% +again and again what's gonna happen is + + + align:start position:0% +again and again what's gonna happen is +the following I'm gonna have my truth + + align:start position:0% +the following I'm gonna have my truth + + + align:start position:0% +the following I'm gonna have my truth +theta that lives here and then on Monday + + align:start position:0% +theta that lives here and then on Monday + + + align:start position:0% +theta that lives here and then on Monday +this is the confidence interval that I + + align:start position:0% +this is the confidence interval that I + + + align:start position:0% +this is the confidence interval that I +build okay so this is the real line the + + align:start position:0% +build okay so this is the real line the + + + align:start position:0% +build okay so this is the real line the +truth theta is here and this is the + + align:start position:0% +truth theta is here and this is the + + + align:start position:0% +truth theta is here and this is the +comfortable I build on Monday + + align:start position:0% +comfortable I build on Monday + + + align:start position:0% +comfortable I build on Monday +all right so X bar was here and this is + + align:start position:0% +all right so X bar was here and this is + + + align:start position:0% +all right so X bar was here and this is +my confidence interval on Tuesday I + + align:start position:0% +my confidence interval on Tuesday I + + + align:start position:0% +my confidence interval on Tuesday I +built this confidence interval maybe + + align:start position:0% +built this confidence interval maybe + + + align:start position:0% +built this confidence interval maybe +thanks bar was closer to theta a bit + + align:start position:0% +thanks bar was closer to theta a bit + + + align:start position:0% +thanks bar was closer to theta a bit +smaller but then on Wednesday I built + + align:start position:0% +smaller but then on Wednesday I built + + + align:start position:0% +smaller but then on Wednesday I built +this confidence interval I'm not here + + align:start position:0% +this confidence interval I'm not here + + + align:start position:0% +this confidence interval I'm not here +it's not in there and that's this case + + align:start position:0% +it's not in there and that's this case + + + align:start position:0% +it's not in there and that's this case +right it happens that it's just not in + + align:start position:0% +right it happens that it's just not in + + + align:start position:0% +right it happens that it's just not in +there and then on Thursday I build + + align:start position:0% +there and then on Thursday I build + + + align:start position:0% +there and then on Thursday I build +another one I almost miss it but I'm in + + align:start position:0% +another one I almost miss it but I'm in + + + align:start position:0% +another one I almost miss it but I'm in +there etc maybe here I miss again and so + + align:start position:0% +there etc maybe here I miss again and so + + + align:start position:0% +there etc maybe here I miss again and so +what it means to have a confidence + + align:start position:0% +what it means to have a confidence + + + align:start position:0% +what it means to have a confidence +interval so what does it mean to have a + + align:start position:0% +interval so what does it mean to have a + + + align:start position:0% +interval so what does it mean to have a +confidence interval at 95% yeah so it + + align:start position:0% +confidence interval at 95% yeah so it + + + align:start position:0% +confidence interval at 95% yeah so it +means that if I repeat this the + + align:start position:0% +means that if I repeat this the + + + align:start position:0% +means that if I repeat this the +frequency of times hence the word + + align:start position:0% +frequency of times hence the word + + + align:start position:0% +frequency of times hence the word +frequentist at which I'm actually going + + align:start position:0% +frequentist at which I'm actually going + + + align:start position:0% +frequentist at which I'm actually going +to overlap that I'm actually going to + + align:start position:0% +to overlap that I'm actually going to + + + align:start position:0% +to overlap that I'm actually going to +contain theta should be 95% that's what + + align:start position:0% +contain theta should be 95% that's what + + + align:start position:0% +contain theta should be 95% that's what +frequencies means so it's just a matter + + align:start position:0% +frequencies means so it's just a matter + + + align:start position:0% +frequencies means so it's just a matter +of life trusting that so on one given + + align:start position:0% +of life trusting that so on one given + + + align:start position:0% +of life trusting that so on one given +thing one given realization of your data + + align:start position:0% +thing one given realization of your data + + + align:start position:0% +thing one given realization of your data +it's not telling you anything right + + align:start position:0% +it's not telling you anything right + + + align:start position:0% +it's not telling you anything right +there is there or not so it's not really + + align:start position:0% +there is there or not so it's not really + + + align:start position:0% +there is there or not so it's not really +something that's actually something that + + align:start position:0% +something that's actually something that + + + align:start position:0% +something that's actually something that +assesses the confidence of your decision + + align:start position:0% +assesses the confidence of your decision + + + align:start position:0% +assesses the confidence of your decision +such as theta is in there or not it's + + align:start position:0% +such as theta is in there or not it's + + + align:start position:0% +such as theta is in there or not it's +something that assesses the confidence + + align:start position:0% +something that assesses the confidence + + + align:start position:0% +something that assesses the confidence +you have in the method that you're using + + align:start position:0% +you have in the method that you're using + + + align:start position:0% +you have in the method that you're using +if you were to repeat it over and again + + align:start position:0% +if you were to repeat it over and again + + + align:start position:0% +if you were to repeat it over and again +would be the same thing + + align:start position:0% +would be the same thing + + + align:start position:0% +would be the same thing +would be 95% of the time correct right + + align:start position:0% +would be 95% of the time correct right + + + align:start position:0% +would be 95% of the time correct right +so for example we know that we could + + align:start position:0% +so for example we know that we could + + + align:start position:0% +so for example we know that we could +build a test right so it's pretty clear + + align:start position:0% +build a test right so it's pretty clear + + + align:start position:0% +build a test right so it's pretty clear +that you can actually build a test for + + align:start position:0% +that you can actually build a test for + + + align:start position:0% +that you can actually build a test for +whether theta is equal to theta naught + + align:start position:0% +whether theta is equal to theta naught + + + align:start position:0% +whether theta is equal to theta naught +or not equal to theta or not by just + + align:start position:0% +or not equal to theta or not by just + + + align:start position:0% +or not equal to theta or not by just +checking whether theta naught is in a + + align:start position:0% +checking whether theta naught is in a + + + align:start position:0% +checking whether theta naught is in a +confidence interval or not and what it + + align:start position:0% +confidence interval or not and what it + + + align:start position:0% +confidence interval or not and what it +means is that if you actually are doing + + align:start position:0% +means is that if you actually are doing + + + align:start position:0% +means is that if you actually are doing +those tests at 90 at 5% then it means + + align:start position:0% +those tests at 90 at 5% then it means + + + align:start position:0% +those tests at 90 at 5% then it means +that 5% of the time you should do this + + align:start position:0% +that 5% of the time you should do this + + + align:start position:0% +that 5% of the time you should do this +over and again 5% of the time you're + + align:start position:0% +over and again 5% of the time you're + + + align:start position:0% +over and again 5% of the time you're +gonna be wrong + + align:start position:0% +gonna be wrong + + + align:start position:0% +gonna be wrong +I mentioned my wife does come does + + align:start position:0% +I mentioned my wife does come does + + + align:start position:0% +I mentioned my wife does come does +market research and she does maybe I + + align:start position:0% +market research and she does maybe I + + + align:start position:0% +market research and she does maybe I +don't know a hundred thousand tests a + + align:start position:0% +don't know a hundred thousand tests a + + + align:start position:0% +don't know a hundred thousand tests a +year and if they do all of them at 1% + + align:start position:0% +year and if they do all of them at 1% + + + align:start position:0% +year and if they do all of them at 1% +then it means that 1% of the time which + + align:start position:0% +then it means that 1% of the time which + + + align:start position:0% +then it means that 1% of the time which +is a lot of time right when you do a + + align:start position:0% +is a lot of time right when you do a + + + align:start position:0% +is a lot of time right when you do a +hundred thousand a year it's 1,000 of + + align:start position:0% +hundred thousand a year it's 1,000 of + + + align:start position:0% +hundred thousand a year it's 1,000 of +them are actually wrong I mean they're + + align:start position:0% +them are actually wrong I mean they're + + + align:start position:0% +them are actually wrong I mean they're +she's actually you know hedging against + + align:start position:0% +she's actually you know hedging against + + + align:start position:0% +she's actually you know hedging against +the fact that 1% of them are going to be + + align:start position:0% +the fact that 1% of them are going to be + + + align:start position:0% +the fact that 1% of them are going to be +wrong that's the thousand of them that + + align:start position:0% +wrong that's the thousand of them that + + + align:start position:0% +wrong that's the thousand of them that +are gonna be wrong just like if you do + + align:start position:0% +are gonna be wrong just like if you do + + + align:start position:0% +are gonna be wrong just like if you do +this a hundred thousand times at 95% + + align:start position:0% +this a hundred thousand times at 95% + + + align:start position:0% +this a hundred thousand times at 95% +five thousand of those guys are actually + + align:start position:0% +five thousand of those guys are actually + + + align:start position:0% +five thousand of those guys are actually +not gonna be the correct ones okay so I + + align:start position:0% +not gonna be the correct ones okay so I + + + align:start position:0% +not gonna be the correct ones okay so I +mean it's kind of scary but that's the + + align:start position:0% +mean it's kind of scary but that's the + + + align:start position:0% +mean it's kind of scary but that's the +way it is so that's what the frequentist + + align:start position:0% +way it is so that's what the frequentist + + + align:start position:0% +way it is so that's what the frequentist +interpretation of this is now as I + + align:start position:0% +interpretation of this is now as I + + + align:start position:0% +interpretation of this is now as I +mentioned when we started this Bayesian + + align:start position:0% +mentioned when we started this Bayesian + + + align:start position:0% +mentioned when we started this Bayesian +chapter I said Bayesian statistics sort + + align:start position:0% +chapter I said Bayesian statistics sort + + + align:start position:0% +chapter I said Bayesian statistics sort +of converge to I mean Bayesian decisions + + align:start position:0% +of converge to I mean Bayesian decisions + + + align:start position:0% +of converge to I mean Bayesian decisions +and Bayesian methods sort of converged + + align:start position:0% +and Bayesian methods sort of converged + + + align:start position:0% +and Bayesian methods sort of converged +to frequentist methods they sort of when + + align:start position:0% +to frequentist methods they sort of when + + + align:start position:0% +to frequentist methods they sort of when +the sample size is large enough they + + align:start position:0% +the sample size is large enough they + + + align:start position:0% +the sample size is large enough they +sort of lead to the same decisions and + + align:start position:0% +sort of lead to the same decisions and + + + align:start position:0% +sort of lead to the same decisions and +in general there need not be the same + + align:start position:0% +in general there need not be the same + + + align:start position:0% +in general there need not be the same +but they tend to actually when the + + align:start position:0% +but they tend to actually when the + + + align:start position:0% +but they tend to actually when the +sample size is large enough to have the + + align:start position:0% +sample size is large enough to have the + + + align:start position:0% +sample size is large enough to have the +same behavior think about for example + + align:start position:0% +same behavior think about for example + + + align:start position:0% +same behavior think about for example +the posterior that you have when you + + align:start position:0% +the posterior that you have when you + + + align:start position:0% +the posterior that you have when you +have in the gaussian case right we said + + align:start position:0% +have in the gaussian case right we said + + + align:start position:0% +have in the gaussian case right we said +that in the gaussian case what you're + + align:start position:0% +that in the gaussian case what you're + + + align:start position:0% +that in the gaussian case what you're +gonna see is that it's as if you had an + + align:start position:0% +gonna see is that it's as if you had an + + + align:start position:0% +gonna see is that it's as if you had an +extra observation which was essentially + + align:start position:0% +extra observation which was essentially + + + align:start position:0% +extra observation which was essentially +given by your prior okay and and now + + align:start position:0% +given by your prior okay and and now + + + align:start position:0% +given by your prior okay and and now +it's the the what's gonna happen is that + + align:start position:0% +it's the the what's gonna happen is that + + + align:start position:0% +it's the the what's gonna happen is that +when the this just one observation among + + align:start position:0% +when the this just one observation among + + + align:start position:0% +when the this just one observation among +n plus one it's really going to be truly + + align:start position:0% +n plus one it's really going to be truly + + + align:start position:0% +n plus one it's really going to be truly +you know drawn and you won't see it when + + align:start position:0% +you know drawn and you won't see it when + + + align:start position:0% +you know drawn and you won't see it when +the sample size grows large + + align:start position:0% +the sample size grows large + + + align:start position:0% +the sample size grows large +so Bayesian methods are particularly + + align:start position:0% +so Bayesian methods are particularly + + + align:start position:0% +so Bayesian methods are particularly +useful when you have a small sample size + + align:start position:0% +useful when you have a small sample size + + + align:start position:0% +useful when you have a small sample size +and when you have a small sample size + + align:start position:0% +and when you have a small sample size + + + align:start position:0% +and when you have a small sample size +you can actually the effect of the prior + + align:start position:0% +you can actually the effect of the prior + + + align:start position:0% +you can actually the effect of the prior +is going to be bigger but most + + align:start position:0% +is going to be bigger but most + + + align:start position:0% +is going to be bigger but most +importantly you're not going to have to + + align:start position:0% +importantly you're not going to have to + + + align:start position:0% +importantly you're not going to have to +repeat this thing + + align:start position:0% +repeat this thing + + + align:start position:0% +repeat this thing +and again and you're gonna have a + + align:start position:0% +and again and you're gonna have a + + + align:start position:0% +and again and you're gonna have a +meaning you're gonna have to have + + align:start position:0% +meaning you're gonna have to have + + + align:start position:0% +meaning you're gonna have to have +something that has a meaning for this + + align:start position:0% +something that has a meaning for this + + + align:start position:0% +something that has a meaning for this +particular data set that you have right + + align:start position:0% +particular data set that you have right + + + align:start position:0% +particular data set that you have right +when I said that the probability that + + align:start position:0% +when I said that the probability that + + + align:start position:0% +when I said that the probability that +theta belongs to R and here I'm going to + + align:start position:0% +theta belongs to R and here I'm going to + + + align:start position:0% +theta belongs to R and here I'm going to +specify the fact that it's a Bayesian + + align:start position:0% +specify the fact that it's a Bayesian + + + align:start position:0% +specify the fact that it's a Bayesian +confidence region like this one this is + + align:start position:0% +confidence region like this one this is + + + align:start position:0% +confidence region like this one this is +actually conditionally on the data that + + align:start position:0% +actually conditionally on the data that + + + align:start position:0% +actually conditionally on the data that +you've collected it says given this data + + align:start position:0% +you've collected it says given this data + + + align:start position:0% +you've collected it says given this data +given the points that you have just put + + align:start position:0% +given the points that you have just put + + + align:start position:0% +given the points that you have just put +in some numbers if you want in there + + align:start position:0% +in some numbers if you want in there + + + align:start position:0% +in some numbers if you want in there +it's actually telling you the + + align:start position:0% +it's actually telling you the + + + align:start position:0% +it's actually telling you the +probability that theta belongs to this + + align:start position:0% +probability that theta belongs to this + + + align:start position:0% +probability that theta belongs to this +Bayesian thing to this Bayesian + + align:start position:0% +Bayesian thing to this Bayesian + + + align:start position:0% +Bayesian thing to this Bayesian +confidence region here since I've + + align:start position:0% +confidence region here since I've + + + align:start position:0% +confidence region here since I've +conditioned on X 1 X n this probability + + align:start position:0% +conditioned on X 1 X n this probability + + + align:start position:0% +conditioned on X 1 X n this probability +is really just with respect to theta + + align:start position:0% +is really just with respect to theta + + + align:start position:0% +is really just with respect to theta +drawn from the prior right and so now it + + align:start position:0% +drawn from the prior right and so now it + + + align:start position:0% +drawn from the prior right and so now it +has a slightly different meaning is just + + align:start position:0% +has a slightly different meaning is just + + + align:start position:0% +has a slightly different meaning is just +telling you that when I it's really + + align:start position:0% +telling you that when I it's really + + + align:start position:0% +telling you that when I it's really +making a statement about where the + + align:start position:0% +making a statement about where the + + + align:start position:0% +making a statement about where the +regions of high probability of your + + align:start position:0% +regions of high probability of your + + + align:start position:0% +regions of high probability of your +posterior are now why is that useful + + align:start position:0% +posterior are now why is that useful + + + align:start position:0% +posterior are now why is that useful +well there was actually there's actually + + align:start position:0% +well there was actually there's actually + + + align:start position:0% +well there was actually there's actually +an interesting story that goes behind + + align:start position:0% +an interesting story that goes behind + + + align:start position:0% +an interesting story that goes behind +Bayesian methods the anybody knows the + + align:start position:0% +Bayesian methods the anybody knows the + + + align:start position:0% +Bayesian methods the anybody knows the +the story of the USS scorpion do you + + align:start position:0% +the story of the USS scorpion do you + + + align:start position:0% +the story of the USS scorpion do you +know this the story so that was a + + align:start position:0% +know this the story so that was a + + + align:start position:0% +know this the story so that was a +American vessel that disappeared I think + + align:start position:0% +American vessel that disappeared I think + + + align:start position:0% +American vessel that disappeared I think +he was like close to Bermuda or + + align:start position:0% +he was like close to Bermuda or + + + align:start position:0% +he was like close to Bermuda or +something but you know you can tell the + + align:start position:0% +something but you know you can tell the + + + align:start position:0% +something but you know you can tell the +story the malaysian airlines' + + align:start position:0% +story the malaysian airlines' + + + align:start position:0% +story the malaysian airlines' +except that i don't think it's such a + + align:start position:0% +except that i don't think it's such a + + + align:start position:0% +except that i don't think it's such a +successful story but the idea was + + align:start position:0% +successful story but the idea was + + + align:start position:0% +successful story but the idea was +essentially we're trying to find where + + align:start position:0% +essentially we're trying to find where + + + align:start position:0% +essentially we're trying to find where +this thing happened and of course you + + align:start position:0% +this thing happened and of course you + + + align:start position:0% +this thing happened and of course you +don't have this is a one-time thing you + + align:start position:0% +don't have this is a one-time thing you + + + align:start position:0% +don't have this is a one-time thing you +actually have you need something that + + align:start position:0% +actually have you need something that + + + align:start position:0% +actually have you need something that +works once it's something that works for + + align:start position:0% +works once it's something that works for + + + align:start position:0% +works once it's something that works for +this particular vessel and you don't + + align:start position:0% +this particular vessel and you don't + + + align:start position:0% +this particular vessel and you don't +care if you go to the navy and you tell + + align:start position:0% +care if you go to the navy and you tell + + + align:start position:0% +care if you go to the navy and you tell +them well you know here's the method and + + align:start position:0% +them well you know here's the method and + + + align:start position:0% +them well you know here's the method and +for ninety five out of a hundred vessels + + align:start position:0% +for ninety five out of a hundred vessels + + + align:start position:0% +for ninety five out of a hundred vessels +that you're gonna lose we're gonna be + + align:start position:0% +that you're gonna lose we're gonna be + + + align:start position:0% +that you're gonna lose we're gonna be +able to find it and and they want this + + align:start position:0% +able to find it and and they want this + + + align:start position:0% +able to find it and and they want this +to work for this particular one and so + + align:start position:0% +to work for this particular one and so + + + align:start position:0% +to work for this particular one and so +they were looking and they were you know + + align:start position:0% +they were looking and they were you know + + + align:start position:0% +they were looking and they were you know +they were diving in different places and + + align:start position:0% +they were diving in different places and + + + align:start position:0% +they were diving in different places and +and suddenly they brought in this guy I + + align:start position:0% +and suddenly they brought in this guy I + + + align:start position:0% +and suddenly they brought in this guy I +forget his name I mean there's a whole + + align:start position:0% +forget his name I mean there's a whole + + + align:start position:0% +forget his name I mean there's a whole +story about this on Wikipedia and he + + align:start position:0% +story about this on Wikipedia and he + + + align:start position:0% +story about this on Wikipedia and he +started collecting the data that they + + align:start position:0% +started collecting the data that they + + + align:start position:0% +started collecting the data that they +had from different dives and maybe from + + align:start position:0% +had from different dives and maybe from + + + align:start position:0% +had from different dives and maybe from +currents and it started to put + + align:start position:0% +currents and it started to put + + + align:start position:0% +currents and it started to put +everything and he said okay what is the + + align:start position:0% +everything and he said okay what is the + + + align:start position:0% +everything and he said okay what is the +posterior distribution of the location + + align:start position:0% +posterior distribution of the location + + + align:start position:0% +posterior distribution of the location +of the vessel given all the things that + + align:start position:0% +of the vessel given all the things that + + + align:start position:0% +of the vessel given all the things that +I've seen and what are you have you seen + + align:start position:0% +I've seen and what are you have you seen + + + align:start position:0% +I've seen and what are you have you seen +well you've seen that + + align:start position:0% +well you've seen that + + + align:start position:0% +well you've seen that +it's not here it's not there and it's + + align:start position:0% +it's not here it's not there and it's + + + align:start position:0% +it's not here it's not there and it's +not there and you've also seen that the + + align:start position:0% +not there and you've also seen that the + + + align:start position:0% +not there and you've also seen that the +currents are going that way and the wind + + align:start position:0% +currents are going that way and the wind + + + align:start position:0% +currents are going that way and the wind +we're going that way and you can + + align:start position:0% +we're going that way and you can + + + align:start position:0% +we're going that way and you can +actually put some model and try to + + align:start position:0% +actually put some model and try to + + + align:start position:0% +actually put some model and try to +understand this now given this for this + + align:start position:0% +understand this now given this for this + + + align:start position:0% +understand this now given this for this +particular data that you have you can + + align:start position:0% +particular data that you have you can + + + align:start position:0% +particular data that you have you can +actually think of having a + + align:start position:0% +actually think of having a + + + align:start position:0% +actually think of having a +two-dimensional density that tells you + + align:start position:0% +two-dimensional density that tells you + + + align:start position:0% +two-dimensional density that tells you +where it's more likely then that the + + align:start position:0% +where it's more likely then that the + + + align:start position:0% +where it's more likely then that the +vessel is and where are you going to be + + align:start position:0% +vessel is and where are you going to be + + + align:start position:0% +vessel is and where are you going to be +looking for well if it's a multi-modal + + align:start position:0% +looking for well if it's a multi-modal + + + align:start position:0% +looking for well if it's a multi-modal +distribution you're just gonna go to the + + align:start position:0% +distribution you're just gonna go to the + + + align:start position:0% +distribution you're just gonna go to the +highest mode first because that's where + + align:start position:0% +highest mode first because that's where + + + align:start position:0% +highest mode first because that's where +it's the most likely to be and maybe + + align:start position:0% +it's the most likely to be and maybe + + + align:start position:0% +it's the most likely to be and maybe +it's not there so you're just gonna + + align:start position:0% +it's not there so you're just gonna + + + align:start position:0% +it's not there so you're just gonna +update your posterior based on the fact + + align:start position:0% +update your posterior based on the fact + + + align:start position:0% +update your posterior based on the fact +that it's not there and do it again + + align:start position:0% +that it's not there and do it again + + + align:start position:0% +that it's not there and do it again +and actually after - two dives I think + + align:start position:0% +and actually after - two dives I think + + + align:start position:0% +and actually after - two dives I think +he actually found the thing and that's + + align:start position:0% +he actually found the thing and that's + + + align:start position:0% +he actually found the thing and that's +exactly where Bayesian statistics start + + align:start position:0% +exactly where Bayesian statistics start + + + align:start position:0% +exactly where Bayesian statistics start +to kick in because you put a lot of + + align:start position:0% +to kick in because you put a lot of + + + align:start position:0% +to kick in because you put a lot of +knowledge into your into your model but + + align:start position:0% +knowledge into your into your model but + + + align:start position:0% +knowledge into your into your model but +you also can actually factor in a bunch + + align:start position:0% +you also can actually factor in a bunch + + + align:start position:0% +you also can actually factor in a bunch +of information right the model you had + + align:start position:0% +of information right the model you had + + + align:start position:0% +of information right the model you had +to build a model that was actually + + align:start position:0% +to build a model that was actually + + + align:start position:0% +to build a model that was actually +taking into account currents and and and + + align:start position:0% +taking into account currents and and and + + + align:start position:0% +taking into account currents and and and +when and what you can't have as a + + align:start position:0% +when and what you can't have as a + + + align:start position:0% +when and what you can't have as a +guarantee is that when you talk about + + align:start position:0% +guarantee is that when you talk about + + + align:start position:0% +guarantee is that when you talk about +the probability that this vessel is you + + align:start position:0% +the probability that this vessel is you + + + align:start position:0% +the probability that this vessel is you +know in this location given what you've + + align:start position:0% +know in this location given what you've + + + align:start position:0% +know in this location given what you've +observed in the past it actually has + + align:start position:0% +observed in the past it actually has + + + align:start position:0% +observed in the past it actually has +some sense whereas if you were to use a + + align:start position:0% +some sense whereas if you were to use a + + + align:start position:0% +some sense whereas if you were to use a +a frequentist approach then there's no + + align:start position:0% +a frequentist approach then there's no + + + align:start position:0% +a frequentist approach then there's no +probability either it's underneath this + + align:start position:0% +probability either it's underneath this + + + align:start position:0% +probability either it's underneath this +position or it's not right so that's + + align:start position:0% +position or it's not right so that's + + + align:start position:0% +position or it's not right so that's +actually where it it start to make sense + + align:start position:0% +actually where it it start to make sense + + + align:start position:0% +actually where it it start to make sense +and so you can actually build this and + + align:start position:0% +and so you can actually build this and + + + align:start position:0% +and so you can actually build this and +there's actually a lot of methods that + + align:start position:0% +there's actually a lot of methods that + + + align:start position:0% +there's actually a lot of methods that +are based on you know for search that + + align:start position:0% +are based on you know for search that + + + align:start position:0% +are based on you know for search that +are based on Bayesian methods I think + + align:start position:0% +are based on Bayesian methods I think + + + align:start position:0% +are based on Bayesian methods I think +for example the Higgs boson which based + + align:start position:0% +for example the Higgs boson which based + + + align:start position:0% +for example the Higgs boson which based +on a lot of Bayesian methods because + + align:start position:0% +on a lot of Bayesian methods because + + + align:start position:0% +on a lot of Bayesian methods because +this is something you need to find once + + align:start position:0% +this is something you need to find once + + + align:start position:0% +this is something you need to find once +right I mean there was a lot of prior + + align:start position:0% +right I mean there was a lot of prior + + + align:start position:0% +right I mean there was a lot of prior +that has to be built in okay so now you + + align:start position:0% +that has to be built in okay so now you + + + align:start position:0% +that has to be built in okay so now you +build this confidence interval and the + + align:start position:0% +build this confidence interval and the + + + align:start position:0% +build this confidence interval and the +nicest way to do it is to use level sets + + align:start position:0% +nicest way to do it is to use level sets + + + align:start position:0% +nicest way to do it is to use level sets +but again just like for gaussians right + + align:start position:0% +but again just like for gaussians right + + + align:start position:0% +but again just like for gaussians right +I mean if I had even in the in the even + + align:start position:0% +I mean if I had even in the in the even + + + align:start position:0% +I mean if I had even in the in the even +in the Gaussian case I decided to go at + + align:start position:0% +in the Gaussian case I decided to go at + + + align:start position:0% +in the Gaussian case I decided to go at +X bar plus or minus something but I + + align:start position:0% +X bar plus or minus something but I + + + align:start position:0% +X bar plus or minus something but I +could go at like something that's + + align:start position:0% +could go at like something that's + + + align:start position:0% +could go at like something that's +completely asymmetric so what's + + align:start position:0% +completely asymmetric so what's + + + align:start position:0% +completely asymmetric so what's +happening is that tier this method + + align:start position:0% +happening is that tier this method + + + align:start position:0% +happening is that tier this method +guarantees that you're gonna have the + + align:start position:0% +guarantees that you're gonna have the + + + align:start position:0% +guarantees that you're gonna have the +narrow as possible confidence intervals + + align:start position:0% +narrow as possible confidence intervals + + + align:start position:0% +narrow as possible confidence intervals +that's essentially what it's telling you + + align:start position:0% +that's essentially what it's telling you + + + align:start position:0% +that's essentially what it's telling you +okay because every time I'm choosing a + + align:start position:0% +okay because every time I'm choosing a + + + align:start position:0% +okay because every time I'm choosing a +point starting from here I'm actually + + align:start position:0% +point starting from here I'm actually + + + align:start position:0% +point starting from here I'm actually +putting as much area under the curve as + + align:start position:0% +putting as much area under the curve as + + + align:start position:0% +putting as much area under the curve as +I can all right + + align:start position:0% +I can all right + + + align:start position:0% +I can all right +so so those are called Bayesian + + align:start position:0% +so so those are called Bayesian + + + align:start position:0% +so so those are called Bayesian +confessional oh yeah and I promise you + + align:start position:0% +confessional oh yeah and I promise you + + + align:start position:0% +confessional oh yeah and I promise you +that we're gonna work on some example + + align:start position:0% +that we're gonna work on some example + + + align:start position:0% +that we're gonna work on some example +that actually sort of sort of give the + + align:start position:0% +that actually sort of sort of give the + + + align:start position:0% +that actually sort of sort of give the +meeting to what I just told you + + align:start position:0% +meeting to what I just told you + + + align:start position:0% +meeting to what I just told you +with like actual numbers so this is + + align:start position:0% +with like actual numbers so this is + + + align:start position:0% +with like actual numbers so this is +something that's taken from Worcester + + align:start position:0% +something that's taken from Worcester + + + align:start position:0% +something that's taken from Worcester +mins book and that's also it's all it's + + align:start position:0% +mins book and that's also it's all it's + + + align:start position:0% +mins book and that's also it's all it's +coming from a paper from stats paper + + align:start position:0% +coming from a paper from stats paper + + + align:start position:0% +coming from a paper from stats paper +from walpert and I don't know who from + + align:start position:0% +from walpert and I don't know who from + + + align:start position:0% +from walpert and I don't know who from +the 80s and essentially this is how it + + align:start position:0% +the 80s and essentially this is how it + + + align:start position:0% +the 80s and essentially this is how it +works + + align:start position:0% +works + + + align:start position:0% +works +so observe assume that you have N equals + + align:start position:0% +so observe assume that you have N equals + + + align:start position:0% +so observe assume that you have N equals +two observations and you have y1 so + + align:start position:0% +two observations and you have y1 so + + + align:start position:0% +two observations and you have y1 so +those observations are y1 let no sorry + + align:start position:0% +those observations are y1 let no sorry + + + align:start position:0% +those observations are y1 let no sorry +let's call them x1 which is theta plus + + align:start position:0% +let's call them x1 which is theta plus + + + align:start position:0% +let's call them x1 which is theta plus +epsilon 1 and X 2 which is theta plus + + align:start position:0% +epsilon 1 and X 2 which is theta plus + + + align:start position:0% +epsilon 1 and X 2 which is theta plus +epsilon 2 or epsilon 1 and epsilon 2 are + + align:start position:0% +epsilon 2 or epsilon 1 and epsilon 2 are + + + align:start position:0% +epsilon 2 or epsilon 1 and epsilon 2 are +iid and the probability that epsilon I + + align:start position:0% +iid and the probability that epsilon I + + + align:start position:0% +iid and the probability that epsilon I +is equal to plus 1 is equal to the + + align:start position:0% +is equal to plus 1 is equal to the + + + align:start position:0% +is equal to plus 1 is equal to the +probability that X 1 I is equal to minus + + align:start position:0% +probability that X 1 I is equal to minus + + + align:start position:0% +probability that X 1 I is equal to minus +1 is equal to 1/2 okay so it's just the + + align:start position:0% +1 is equal to 1/2 okay so it's just the + + + align:start position:0% +1 is equal to 1/2 okay so it's just the +uniform sign plus minus 1 okay now let's + + align:start position:0% +uniform sign plus minus 1 okay now let's + + + align:start position:0% +uniform sign plus minus 1 okay now let's +think about so you're trying to do some + + align:start position:0% +think about so you're trying to do some + + + align:start position:0% +think about so you're trying to do some +inference on theta maybe you actually + + align:start position:0% +inference on theta maybe you actually + + + align:start position:0% +inference on theta maybe you actually +want to find some inference on theta + + align:start position:0% +want to find some inference on theta + + + align:start position:0% +want to find some inference on theta +that's actually based on and that's + + align:start position:0% +that's actually based on and that's + + + align:start position:0% +that's actually based on and that's +based only on the epsilon x1 and x2 okay + + align:start position:0% +based only on the epsilon x1 and x2 okay + + + align:start position:0% +based only on the epsilon x1 and x2 okay +so I'm gonna actually build a confidence + + align:start position:0% +so I'm gonna actually build a confidence + + + align:start position:0% +so I'm gonna actually build a confidence +interval but what I really want to build + + align:start position:0% +interval but what I really want to build + + + align:start position:0% +interval but what I really want to build +is a is but let's start thinking about + + align:start position:0% +is a is but let's start thinking about + + + align:start position:0% +is a is but let's start thinking about +how I would find an estimator for those + + align:start position:0% +how I would find an estimator for those + + + align:start position:0% +how I would find an estimator for those +two things well what values am I going + + align:start position:0% +two things well what values am I going + + + align:start position:0% +two things well what values am I going +to be getting right so I'm gonna get + + align:start position:0% +to be getting right so I'm gonna get + + + align:start position:0% +to be getting right so I'm gonna get +either theta plus 1 or theta minus 1 and + + align:start position:0% +either theta plus 1 or theta minus 1 and + + + align:start position:0% +either theta plus 1 or theta minus 1 and +actually I can get basically four + + align:start position:0% +actually I can get basically four + + + align:start position:0% +actually I can get basically four +different observations right sorry four + + align:start position:0% +different observations right sorry four + + + align:start position:0% +different observations right sorry four +different pairs of observations + + align:start position:0% + + + + align:start position:0% + +plus plus theta minus Oh agreed + + align:start position:0% +plus plus theta minus Oh agreed + + + align:start position:0% +plus plus theta minus Oh agreed +those are the four possible observations + + align:start position:0% +those are the four possible observations + + + align:start position:0% +those are the four possible observations +that I can get agree either they're both + + align:start position:0% +that I can get agree either they're both + + + align:start position:0% +that I can get agree either they're both +equal to plus one + + align:start position:0% +equal to plus one + + + align:start position:0% +equal to plus one +the both equal to minus one or one of + + align:start position:0% +the both equal to minus one or one of + + + align:start position:0% +the both equal to minus one or one of +the two is equal to plus one the other + + align:start position:0% +the two is equal to plus one the other + + + align:start position:0% +the two is equal to plus one the other +one to minus one for the Epsilon's okay + + align:start position:0% +one to minus one for the Epsilon's okay + + + align:start position:0% +one to minus one for the Epsilon's okay +so the four observations I can get so in + + align:start position:0% +so the four observations I can get so in + + + align:start position:0% +so the four observations I can get so in +particular if they take the same value + + align:start position:0% +particular if they take the same value + + + align:start position:0% +particular if they take the same value +you know it's it's either theta plus 1 + + align:start position:0% +you know it's it's either theta plus 1 + + + align:start position:0% +you know it's it's either theta plus 1 +or theta minus 1 and if they take a + + align:start position:0% +or theta minus 1 and if they take a + + + align:start position:0% +or theta minus 1 and if they take a +different value I know one of them is + + align:start position:0% +different value I know one of them is + + + align:start position:0% +different value I know one of them is +theta plus one and one is actually theta + + align:start position:0% +theta plus one and one is actually theta + + + align:start position:0% +theta plus one and one is actually theta +minus one so in particular if I take the + + align:start position:0% +minus one so in particular if I take the + + + align:start position:0% +minus one so in particular if I take the +average of those two guys when they take + + align:start position:0% +average of those two guys when they take + + + align:start position:0% +average of those two guys when they take +different values I know I'm actually + + align:start position:0% +different values I know I'm actually + + + align:start position:0% +different values I know I'm actually +getting clear too right so let's build a + + align:start position:0% +getting clear too right so let's build a + + + align:start position:0% +getting clear too right so let's build a +confidence region okay so I'm actually + + align:start position:0% +confidence region okay so I'm actually + + + align:start position:0% +confidence region okay so I'm actually +going to take a conference region which + + align:start position:0% +going to take a conference region which + + + align:start position:0% +going to take a conference region which +is just a singleton and I'm gonna say + + align:start position:0% +is just a singleton and I'm gonna say + + + align:start position:0% +is just a singleton and I'm gonna say +the following + + align:start position:0% +the following + + + align:start position:0% +the following +well if x1 is equal to x2 I'm just gonna + + align:start position:0% +well if x1 is equal to x2 I'm just gonna + + + align:start position:0% +well if x1 is equal to x2 I'm just gonna +take x1 minus 1 okay so I'm just saying + + align:start position:0% +take x1 minus 1 okay so I'm just saying + + + align:start position:0% +take x1 minus 1 okay so I'm just saying +well I'm never gonna be able to resolve + + align:start position:0% +well I'm never gonna be able to resolve + + + align:start position:0% +well I'm never gonna be able to resolve +whether it's plus 1 or minus 1 that + + align:start position:0% +whether it's plus 1 or minus 1 that + + + align:start position:0% +whether it's plus 1 or minus 1 that +actually gives me the best one so I'm + + align:start position:0% +actually gives me the best one so I'm + + + align:start position:0% +actually gives me the best one so I'm +just gonna take a dive and say well it's + + align:start position:0% +just gonna take a dive and say well it's + + + align:start position:0% +just gonna take a dive and say well it's +just plus 1 okay and then if they're + + align:start position:0% +just plus 1 okay and then if they're + + + align:start position:0% +just plus 1 okay and then if they're +different then here I can do much better + + align:start position:0% +different then here I can do much better + + + align:start position:0% +different then here I can do much better +I'm gonna actually just take the average + + align:start position:0% + + + + align:start position:0% + +okay now what I claim is that this is a + + align:start position:0% +okay now what I claim is that this is a + + + align:start position:0% +okay now what I claim is that this is a +confidence region and by default when I + + align:start position:0% +confidence region and by default when I + + + align:start position:0% +confidence region and by default when I +don't mention it this is a frequentist + + align:start position:0% + + + + align:start position:0% + +confidence region at level 75 percent + + align:start position:0% +confidence region at level 75 percent + + + align:start position:0% +confidence region at level 75 percent +okay so let's just check that to check + + align:start position:0% +okay so let's just check that to check + + + align:start position:0% +okay so let's just check that to check +that this is correct I need to check + + align:start position:0% +that this is correct I need to check + + + align:start position:0% +that this is correct I need to check +that the probability under the + + align:start position:0% +that the probability under the + + + align:start position:0% +that the probability under the +realization of x1 and x2 that theta + + align:start position:0% +realization of x1 and x2 that theta + + + align:start position:0% +realization of x1 and x2 that theta +belongs is one of those two guys is + + align:start position:0% +belongs is one of those two guys is + + + align:start position:0% +belongs is one of those two guys is +actually equal to point 75 + + align:start position:0% +actually equal to point 75 + + + align:start position:0% +actually equal to point 75 +yes + + align:start position:0% + + + + align:start position:0% + +it's just a frequencies confidence + + align:start position:0% +it's just a frequencies confidence + + + align:start position:0% +it's just a frequencies confidence +interval that need not it does not need + + align:start position:0% +interval that need not it does not need + + + align:start position:0% +interval that need not it does not need +to be an interval actually in this case + + align:start position:0% +to be an interval actually in this case + + + align:start position:0% +to be an interval actually in this case +it's gonna be an interval but that's + + align:start position:0% +it's gonna be an interval but that's + + + align:start position:0% +it's gonna be an interval but that's +just what it means + + align:start position:0% +just what it means + + + align:start position:0% +just what it means +yeah Region four Bayesian was just + + align:start position:0% +yeah Region four Bayesian was just + + + align:start position:0% +yeah Region four Bayesian was just +because I mean the confidence intervals + + align:start position:0% +because I mean the confidence intervals + + + align:start position:0% +because I mean the confidence intervals +when we're frequentist we tend to make + + align:start position:0% +when we're frequentist we tend to make + + + align:start position:0% +when we're frequentist we tend to make +them intervals by because we want but + + align:start position:0% +them intervals by because we want but + + + align:start position:0% +them intervals by because we want but +when your vision you're doing this + + align:start position:0% +when your vision you're doing this + + + align:start position:0% +when your vision you're doing this +levels that thing you cannot really + + align:start position:0% +levels that thing you cannot really + + + align:start position:0% +levels that thing you cannot really +guarantee unless it's unimodal it's + + align:start position:0% +guarantee unless it's unimodal it's + + + align:start position:0% +guarantee unless it's unimodal it's +gonna be an integral so region is just a + + align:start position:0% +gonna be an integral so region is just a + + + align:start position:0% +gonna be an integral so region is just a +way to not have to say interval in case + + align:start position:0% +way to not have to say interval in case + + + align:start position:0% +way to not have to say interval in case +it's not okay so I have this distinct so + + align:start position:0% +it's not okay so I have this distinct so + + + align:start position:0% +it's not okay so I have this distinct so +what I need to check is the probability + + align:start position:0% +what I need to check is the probability + + + align:start position:0% +what I need to check is the probability +that theta is in one of those two things + + align:start position:0% +that theta is in one of those two things + + + align:start position:0% +that theta is in one of those two things +right so what I need to find is the + + align:start position:0% +right so what I need to find is the + + + align:start position:0% +right so what I need to find is the +probability of theta is in in well X 1 + + align:start position:0% +probability of theta is in in well X 1 + + + align:start position:0% +probability of theta is in in well X 1 +minus 1 and X 1 is not equal to X 2 and + + align:start position:0% +minus 1 and X 1 is not equal to X 2 and + + + align:start position:0% +minus 1 and X 1 is not equal to X 2 and +those are disjoint events is the plus + + align:start position:0% +those are disjoint events is the plus + + + align:start position:0% +those are disjoint events is the plus +the probability of theta is in X 1 plus + + align:start position:0% +the probability of theta is in X 1 plus + + + align:start position:0% +the probability of theta is in X 1 plus +X 2 over 2 and X 1 sorry that's equal + + align:start position:0% +X 2 over 2 and X 1 sorry that's equal + + + align:start position:0% +X 2 over 2 and X 1 sorry that's equal +that's different okay and okay just + + align:start position:0% +that's different okay and okay just + + + align:start position:0% +that's different okay and okay just +before we actually finish the + + align:start position:0% +before we actually finish the + + + align:start position:0% +before we actually finish the +computation why do I have 75% so + + align:start position:0% +computation why do I have 75% so + + + align:start position:0% +computation why do I have 75% so +refreshed percent is 3/4 so it means + + align:start position:0% +refreshed percent is 3/4 so it means + + + align:start position:0% +refreshed percent is 3/4 so it means +that we have four cases and essentially + + align:start position:0% +that we have four cases and essentially + + + align:start position:0% +that we have four cases and essentially +I did not account for one case and it's + + align:start position:0% +I did not account for one case and it's + + + align:start position:0% +I did not account for one case and it's +true I did not account for this case + + align:start position:0% +true I did not account for this case + + + align:start position:0% +true I did not account for this case +when the both of the epsilon i's are + + align:start position:0% +when the both of the epsilon i's are + + + align:start position:0% +when the both of the epsilon i's are +equal to minus 1 right so this is + + align:start position:0% +equal to minus 1 right so this is + + + align:start position:0% +equal to minus 1 right so this is +essentially the one I'm not gonna be + + align:start position:0% +essentially the one I'm not gonna be + + + align:start position:0% +essentially the one I'm not gonna be +able to account for and so we'll see + + align:start position:0% +able to account for and so we'll see + + + align:start position:0% +able to account for and so we'll see +that in a second so in this case we know + + align:start position:0% +that in a second so in this case we know + + + align:start position:0% +that in a second so in this case we know +that everything goes great right so in + + align:start position:0% +that everything goes great right so in + + + align:start position:0% +that everything goes great right so in +this case this is okay well that's just + + align:start position:0% +this case this is okay well that's just + + + align:start position:0% +this case this is okay well that's just +right + + align:start position:0% +right + + + align:start position:0% +right +let's start from the first line so the + + align:start position:0% +let's start from the first line so the + + + align:start position:0% +let's start from the first line so the +first line is the probability that theta + + align:start position:0% +first line is the probability that theta + + + align:start position:0% +first line is the probability that theta +is equal to X 1 minus 1 and those two + + align:start position:0% +is equal to X 1 minus 1 and those two + + + align:start position:0% +is equal to X 1 minus 1 and those two +are equal so this is the probability + + align:start position:0% +are equal so this is the probability + + + align:start position:0% +are equal so this is the probability +that theta is equal to well this is what + + align:start position:0% +that theta is equal to well this is what + + + align:start position:0% +that theta is equal to well this is what +this is theta plus epsilon 1 minus 1 and + + align:start position:0% + + + + align:start position:0% + +epsilon 1 is equal to epsilon 2 + + align:start position:0% + + + + align:start position:0% + +right because I can remove the theta + + align:start position:0% +right because I can remove the theta + + + align:start position:0% +right because I can remove the theta +from here and I can actually remove the + + align:start position:0% +from here and I can actually remove the + + + align:start position:0% +from here and I can actually remove the +theta from here so that this guy here is + + align:start position:0% +theta from here so that this guy here is + + + align:start position:0% +theta from here so that this guy here is +just epsilon one is equal to one so when + + align:start position:0% +just epsilon one is equal to one so when + + + align:start position:0% +just epsilon one is equal to one so when +I intersect with this guy it's actually + + align:start position:0% +I intersect with this guy it's actually + + + align:start position:0% +I intersect with this guy it's actually +the same thing as epsilon 1 is equal to + + align:start position:0% +the same thing as epsilon 1 is equal to + + + align:start position:0% +the same thing as epsilon 1 is equal to +one as well epsilon 2 is equal to 1 is 1 + + align:start position:0% +one as well epsilon 2 is equal to 1 is 1 + + + align:start position:0% +one as well epsilon 2 is equal to 1 is 1 +okay so this first thing is actually + + align:start position:0% +okay so this first thing is actually + + + align:start position:0% +okay so this first thing is actually +equal to the probability that epsilon 1 + + align:start position:0% +equal to the probability that epsilon 1 + + + align:start position:0% +equal to the probability that epsilon 1 +is equal to 1 and epsilon 2 is equal to + + align:start position:0% +is equal to 1 and epsilon 2 is equal to + + + align:start position:0% +is equal to 1 and epsilon 2 is equal to +1 which is equal to what we have 1/4 + + align:start position:0% +1 which is equal to what we have 1/4 + + + align:start position:0% +1 which is equal to what we have 1/4 +right so that's just the first case over + + align:start position:0% +right so that's just the first case over + + + align:start position:0% +right so that's just the first case over +there they're independent now I still + + align:start position:0% +there they're independent now I still + + + align:start position:0% +there they're independent now I still +need to do the second one so this case + + align:start position:0% +need to do the second one so this case + + + align:start position:0% +need to do the second one so this case +is what well when those things are equal + + align:start position:0% +is what well when those things are equal + + + align:start position:0% +is what well when those things are equal +X 1 plus X 2 over 2 is what well I get + + align:start position:0% +X 1 plus X 2 over 2 is what well I get + + + align:start position:0% +X 1 plus X 2 over 2 is what well I get +theta plus theta over 2 so that's just + + align:start position:0% +theta plus theta over 2 so that's just + + + align:start position:0% +theta plus theta over 2 so that's just +equal to the probability that epsilon 1 + + align:start position:0% +equal to the probability that epsilon 1 + + + align:start position:0% +equal to the probability that epsilon 1 +plus epsilon 2 over 2 is equal to 0 and + + align:start position:0% +plus epsilon 2 over 2 is equal to 0 and + + + align:start position:0% +plus epsilon 2 over 2 is equal to 0 and +epsilon 1 is different from epsilon 2 + + align:start position:0% +epsilon 1 is different from epsilon 2 + + + align:start position:0% +epsilon 1 is different from epsilon 2 +agreed I just removed the Thetas from + + align:start position:0% +agreed I just removed the Thetas from + + + align:start position:0% +agreed I just removed the Thetas from +these equations because I can't they're + + align:start position:0% +these equations because I can't they're + + + align:start position:0% +these equations because I can't they're +just on both sides every time ok and so + + align:start position:0% +just on both sides every time ok and so + + + align:start position:0% +just on both sides every time ok and so +that means what that means that the + + align:start position:0% +that means what that means that the + + + align:start position:0% +that means what that means that the +second part so this thing is actually + + align:start position:0% +second part so this thing is actually + + + align:start position:0% +second part so this thing is actually +equal to 1/4 plus the probability at + + align:start position:0% +equal to 1/4 plus the probability at + + + align:start position:0% +equal to 1/4 plus the probability at +epsilon 1 and epsilon 2 over 2 is equal + + align:start position:0% +epsilon 1 and epsilon 2 over 2 is equal + + + align:start position:0% +epsilon 1 and epsilon 2 over 2 is equal +to 0 I can remove the 2 so this is just + + align:start position:0% +to 0 I can remove the 2 so this is just + + + align:start position:0% +to 0 I can remove the 2 so this is just +the probably at 1 is 1 and the other one + + align:start position:0% +the probably at 1 is 1 and the other one + + + align:start position:0% +the probably at 1 is 1 and the other one +is minus 1 right + + align:start position:0% +is minus 1 right + + + align:start position:0% +is minus 1 right +so that's equal to the probability that + + align:start position:0% +so that's equal to the probability that + + + align:start position:0% +so that's equal to the probability that +epsilon 1 is equal to 1 and epsilon 2 is + + align:start position:0% +epsilon 1 is equal to 1 and epsilon 2 is + + + align:start position:0% +epsilon 1 is equal to 1 and epsilon 2 is +equal to minus 1 plus the probability + + align:start position:0% +equal to minus 1 plus the probability + + + align:start position:0% +equal to minus 1 plus the probability +that epsilon 1 is equal to minus 1 and + + align:start position:0% +that epsilon 1 is equal to minus 1 and + + + align:start position:0% +that epsilon 1 is equal to minus 1 and +epsilon 2 is equal to plus 1 ok because + + align:start position:0% +epsilon 2 is equal to plus 1 ok because + + + align:start position:0% +epsilon 2 is equal to plus 1 ok because +they're disjoint events so I can break + + align:start position:0% +they're disjoint events so I can break + + + align:start position:0% +they're disjoint events so I can break +them into the sum of the two and each of + + align:start position:0% +them into the sum of the two and each of + + + align:start position:0% +them into the sum of the two and each of +those guy is also one of the you know + + align:start position:0% +those guy is also one of the you know + + + align:start position:0% +those guy is also one of the you know +atomic part of it right one of the basic + + align:start position:0% +atomic part of it right one of the basic + + + align:start position:0% +atomic part of it right one of the basic +things and so each of those guys has + + align:start position:0% +things and so each of those guys has + + + align:start position:0% +things and so each of those guys has +probability 1/4 and so here we can + + align:start position:0% +probability 1/4 and so here we can + + + align:start position:0% +probability 1/4 and so here we can +really see that we accounted for + + align:start position:0% +really see that we accounted for + + + align:start position:0% +really see that we accounted for +everything except for the case when + + align:start position:0% +everything except for the case when + + + align:start position:0% +everything except for the case when +epsilon 1 was equal to minus 1 and + + align:start position:0% +epsilon 1 was equal to minus 1 and + + + align:start position:0% +epsilon 1 was equal to minus 1 and +epsilon 2 is equal to minus 1 so this is + + align:start position:0% +epsilon 2 is equal to minus 1 so this is + + + align:start position:0% +epsilon 2 is equal to minus 1 so this is +1/4 this is 1/4 so the whole thing is + + align:start position:0% +1/4 this is 1/4 so the whole thing is + + + align:start position:0% +1/4 this is 1/4 so the whole thing is +equal to 3/4 so now what we have is that + + align:start position:0% +equal to 3/4 so now what we have is that + + + align:start position:0% +equal to 3/4 so now what we have is that +the probability that epsilon 1 + + align:start position:0% +the probability that epsilon 1 + + + align:start position:0% +the probability that epsilon 1 +is in so the probability that theta + + align:start position:0% +is in so the probability that theta + + + align:start position:0% +is in so the probability that theta +belongs to this conference region is + + align:start position:0% +belongs to this conference region is + + + align:start position:0% +belongs to this conference region is +equal to 3/4 and that's very nice and + + align:start position:0% +equal to 3/4 and that's very nice and + + + align:start position:0% +equal to 3/4 and that's very nice and +you know but the thing is some people + + align:start position:0% +you know but the thing is some people + + + align:start position:0% +you know but the thing is some people +are sort of I mean it's not super nice + + align:start position:0% +are sort of I mean it's not super nice + + + align:start position:0% +are sort of I mean it's not super nice +to be able to say this because in a way + + align:start position:0% +to be able to say this because in a way + + + align:start position:0% +to be able to say this because in a way +I know that if I observe X 1 and X 2 + + align:start position:0% +I know that if I observe X 1 and X 2 + + + align:start position:0% +I know that if I observe X 1 and X 2 +that are different I know for sure that + + align:start position:0% +that are different I know for sure that + + + align:start position:0% +that are different I know for sure that +X is that theta that I actually got the + + align:start position:0% +X is that theta that I actually got the + + + align:start position:0% +X is that theta that I actually got the +right data right that this confidence + + align:start position:0% +right data right that this confidence + + + align:start position:0% +right data right that this confidence +interval is actually happening at a with + + align:start position:0% +interval is actually happening at a with + + + align:start position:0% +interval is actually happening at a with +probability 1 and the problem is that I + + align:start position:0% +probability 1 and the problem is that I + + + align:start position:0% +probability 1 and the problem is that I +do not know I cannot make this precise + + align:start position:0% +do not know I cannot make this precise + + + align:start position:0% +do not know I cannot make this precise +with the notion of frequentist + + align:start position:0% +with the notion of frequentist + + + align:start position:0% +with the notion of frequentist +confidence intervals okay because + + align:start position:0% +confidence intervals okay because + + + align:start position:0% +confidence intervals okay because +frequencies conference intervals have to + + align:start position:0% +frequencies conference intervals have to + + + align:start position:0% +frequencies conference intervals have to +account for the fact that in the future + + align:start position:0% +account for the fact that in the future + + + align:start position:0% +account for the fact that in the future +it might not be the case that x1 and x2 + + align:start position:0% +it might not be the case that x1 and x2 + + + align:start position:0% +it might not be the case that x1 and x2 +are different so Bayesian confidence + + align:start position:0% +are different so Bayesian confidence + + + align:start position:0% +are different so Bayesian confidence +regions by definition well they're all + + align:start position:0% +regions by definition well they're all + + + align:start position:0% +regions by definition well they're all +gone but they're conditioned on the data + + align:start position:0% +gone but they're conditioned on the data + + + align:start position:0% +gone but they're conditioned on the data +that I have and so that's what I want I + + align:start position:0% +that I have and so that's what I want I + + + align:start position:0% +that I have and so that's what I want I +want to be able to make a statement + + align:start position:0% +want to be able to make a statement + + + align:start position:0% +want to be able to make a statement +conditionally on the on the data that I + + align:start position:0% +conditionally on the on the data that I + + + align:start position:0% +conditionally on the on the data that I +have okay so if I want to be able to + + align:start position:0% +have okay so if I want to be able to + + + align:start position:0% +have okay so if I want to be able to +make this statement I'm gonna have to + + align:start position:0% +make this statement I'm gonna have to + + + align:start position:0% +make this statement I'm gonna have to +put if I want to build a Bayesian + + align:start position:0% +put if I want to build a Bayesian + + + align:start position:0% +put if I want to build a Bayesian +confidence region I'm gonna have to put + + align:start position:0% +confidence region I'm gonna have to put + + + align:start position:0% +confidence region I'm gonna have to put +a prior on theta so without loss of + + align:start position:0% +a prior on theta so without loss of + + + align:start position:0% +a prior on theta so without loss of +generality I mean maybe with but let's + + align:start position:0% +generality I mean maybe with but let's + + + align:start position:0% +generality I mean maybe with but let's +say assume that pi is a prior on theta + + align:start position:0% +say assume that pi is a prior on theta + + + align:start position:0% +say assume that pi is a prior on theta +and let's assume that pi of j is + + align:start position:0% +and let's assume that pi of j is + + + align:start position:0% +and let's assume that pi of j is +strictly positive for all integers J + + align:start position:0% +strictly positive for all integers J + + + align:start position:0% +strictly positive for all integers J +equals say 0 well actually for all J in + + align:start position:0% +equals say 0 well actually for all J in + + + align:start position:0% +equals say 0 well actually for all J in +the integers ok positive or negative ok + + align:start position:0% +the integers ok positive or negative ok + + + align:start position:0% +the integers ok positive or negative ok +so that's a pretty weak assumption on my + + align:start position:0% +so that's a pretty weak assumption on my + + + align:start position:0% +so that's a pretty weak assumption on my +prior I'm just saying I'm just assuming + + align:start position:0% +prior I'm just saying I'm just assuming + + + align:start position:0% +prior I'm just saying I'm just assuming +that theta is some integer and now let's + + align:start position:0% +that theta is some integer and now let's + + + align:start position:0% +that theta is some integer and now let's +build our confidence or a Bayesian + + align:start position:0% +build our confidence or a Bayesian + + + align:start position:0% +build our confidence or a Bayesian +confidence region well if I want to + + align:start position:0% +confidence region well if I want to + + + align:start position:0% +confidence region well if I want to +build a Bayesian confidence region I + + align:start position:0% +build a Bayesian confidence region I + + + align:start position:0% +build a Bayesian confidence region I +need to understand what my posterior is + + align:start position:0% +need to understand what my posterior is + + + align:start position:0% +need to understand what my posterior is +gonna be okay and if I want to + + align:start position:0% +gonna be okay and if I want to + + + align:start position:0% +gonna be okay and if I want to +understand what my posterior is gonna be + + align:start position:0% +understand what my posterior is gonna be + + + align:start position:0% +understand what my posterior is gonna be +I actually need to build + + align:start position:0% +I actually need to build + + + align:start position:0% +I actually need to build +a likelihood right so we know that it's + + align:start position:0% +a likelihood right so we know that it's + + + align:start position:0% +a likelihood right so we know that it's +the product of the likelihood and of the + + align:start position:0% +the product of the likelihood and of the + + + align:start position:0% +the product of the likelihood and of the +prior / okay so so what is my likelihood + + align:start position:0% +prior / okay so so what is my likelihood + + + align:start position:0% +prior / okay so so what is my likelihood +right so my likelihood is the + + align:start position:0% +right so my likelihood is the + + + align:start position:0% +right so my likelihood is the +probability of x1 x2 given theta right + + align:start position:0% +probability of x1 x2 given theta right + + + align:start position:0% +probability of x1 x2 given theta right +that's what the likelihood should be and + + align:start position:0% +that's what the likelihood should be and + + + align:start position:0% +that's what the likelihood should be and +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +now let's say that actually just to make + + align:start position:0% +now let's say that actually just to make + + + align:start position:0% +now let's say that actually just to make +things a little simpler let us assume + + align:start position:0% +things a little simpler let us assume + + + align:start position:0% +things a little simpler let us assume +that X 1 is equal to I don't know 5 and + + align:start position:0% +that X 1 is equal to I don't know 5 and + + + align:start position:0% +that X 1 is equal to I don't know 5 and +X 2 is equal to 7 + + align:start position:0% +X 2 is equal to 7 + + + align:start position:0% +X 2 is equal to 7 +okay so this is exactly I'm not going to + + align:start position:0% +okay so this is exactly I'm not going to + + + align:start position:0% +okay so this is exactly I'm not going to +take the case where they're actually + + align:start position:0% +take the case where they're actually + + + align:start position:0% +take the case where they're actually +equal to each other because they know + + align:start position:0% +equal to each other because they know + + + align:start position:0% +equal to each other because they know +that in this case x1 and x2 are + + align:start position:0% +that in this case x1 and x2 are + + + align:start position:0% +that in this case x1 and x2 are +different I know I'm gonna actually nail + + align:start position:0% +different I know I'm gonna actually nail + + + align:start position:0% +different I know I'm gonna actually nail +exactly what data is by looking at the + + align:start position:0% +exactly what data is by looking at the + + + align:start position:0% +exactly what data is by looking at the +average of those guys right here it must + + align:start position:0% +average of those guys right here it must + + + align:start position:0% +average of those guys right here it must +be that theta is equal to 0 to 6 so what + + align:start position:0% +be that theta is equal to 0 to 6 so what + + + align:start position:0% +be that theta is equal to 0 to 6 so what +I want is to compute the likelihood at 5 + + align:start position:0% +I want is to compute the likelihood at 5 + + + align:start position:0% +I want is to compute the likelihood at 5 +& 7 + + align:start position:0% +& 7 + + + align:start position:0% +& 7 +okay what is this likelihood well if + + align:start position:0% +okay what is this likelihood well if + + + align:start position:0% +okay what is this likelihood well if +theta is equal to 6 that's just the + + align:start position:0% +theta is equal to 6 that's just the + + + align:start position:0% +theta is equal to 6 that's just the +probability that I observe 5 & 7 right + + align:start position:0% +probability that I observe 5 & 7 right + + + align:start position:0% +probability that I observe 5 & 7 right +so what is the probability observe 5 & 7 + + align:start position:0% + + + + align:start position:0% + +yeah one that's 1/4 right is the + + align:start position:0% +yeah one that's 1/4 right is the + + + align:start position:0% +yeah one that's 1/4 right is the +probability I have minus 1 on the first + + align:start position:0% +probability I have minus 1 on the first + + + align:start position:0% +probability I have minus 1 on the first +on the for the first epsilon 1 right so + + align:start position:0% +on the for the first epsilon 1 right so + + + align:start position:0% +on the for the first epsilon 1 right so +this is an if then a 6 this is the + + align:start position:0% +this is an if then a 6 this is the + + + align:start position:0% +this is an if then a 6 this is the +probability that epsilon 1 is equal to + + align:start position:0% +probability that epsilon 1 is equal to + + + align:start position:0% +probability that epsilon 1 is equal to +plus one a to minus 1 and epsilon 2 is + + align:start position:0% +plus one a to minus 1 and epsilon 2 is + + + align:start position:0% +plus one a to minus 1 and epsilon 2 is +equal to plus 1 which is equal to 1/4 so + + align:start position:0% +equal to plus 1 which is equal to 1/4 so + + + align:start position:0% +equal to plus 1 which is equal to 1/4 so +this probability is 1/4 if theta is + + align:start position:0% +this probability is 1/4 if theta is + + + align:start position:0% +this probability is 1/4 if theta is +different from 6 what is this + + align:start position:0% +different from 6 what is this + + + align:start position:0% +different from 6 what is this +probability so if theta is different + + align:start position:0% +probability so if theta is different + + + align:start position:0% +probability so if theta is different +from 6 since we know that we've only + + align:start position:0% +from 6 since we know that we've only + + + align:start position:0% +from 6 since we know that we've only +loaded the integers right so theta has + + align:start position:0% +loaded the integers right so theta has + + + align:start position:0% +loaded the integers right so theta has +to be another integer what is the + + align:start position:0% +to be another integer what is the + + + align:start position:0% +to be another integer what is the +probability that I see 5 and 7 0 so + + align:start position:0% +probability that I see 5 and 7 0 so + + + align:start position:0% +probability that I see 5 and 7 0 so +that's my likelihood and if I want to + + align:start position:0% +that's my likelihood and if I want to + + + align:start position:0% +that's my likelihood and if I want to +know what my posterior is well it's just + + align:start position:0% +know what my posterior is well it's just + + + align:start position:0% +know what my posterior is well it's just +pi of theta times P of 5 6 given theta + + align:start position:0% +pi of theta times P of 5 6 given theta + + + align:start position:0% +pi of theta times P of 5 6 given theta +divided by the sum over all cheese say + + align:start position:0% +divided by the sum over all cheese say + + + align:start position:0% +divided by the sum over all cheese say +in Z all right so now I just need to + + align:start position:0% +in Z all right so now I just need to + + + align:start position:0% +in Z all right so now I just need to +normalize this thing so of PI of T P of + + align:start position:0% +normalize this thing so of PI of T P of + + + align:start position:0% +normalize this thing so of PI of T P of +5 6 given T agree that's just the + + align:start position:0% +5 6 given T agree that's just the + + + align:start position:0% +5 6 given T agree that's just the +definition of the posterior but when I + + align:start position:0% +definition of the posterior but when I + + + align:start position:0% +definition of the posterior but when I +sum these guys there's only one that + + align:start position:0% +sum these guys there's only one that + + + align:start position:0% +sum these guys there's only one that +counts because for those things we know + + align:start position:0% +counts because for those things we know + + + align:start position:0% +counts because for those things we know +that this is actually equal to 0 for + + align:start position:0% +that this is actually equal to 0 for + + + align:start position:0% +that this is actually equal to 0 for +every T except for when T is equal to 6 + + align:start position:0% +every T except for when T is equal to 6 + + + align:start position:0% +every T except for when T is equal to 6 +so this entire sum here is actually + + align:start position:0% +so this entire sum here is actually + + + align:start position:0% +so this entire sum here is actually +equal to PI of 6 times P of 5 6 + + align:start position:0% +equal to PI of 6 times P of 5 6 + + + align:start position:0% +equal to PI of 6 times P of 5 6 +sorry 5 7 of 5 7 + + align:start position:0% +sorry 5 7 of 5 7 + + + align:start position:0% +sorry 5 7 of 5 7 +given that I see given that theta is + + align:start position:0% +given that I see given that theta is + + + align:start position:0% +given that I see given that theta is +equal to 6 which we know is equal to 1/4 + + align:start position:0% +equal to 6 which we know is equal to 1/4 + + + align:start position:0% +equal to 6 which we know is equal to 1/4 +and I did not tell you what PI of 6 was + + align:start position:0% + + + + align:start position:0% + +right + + align:start position:0% +right + + + align:start position:0% +right +but it's the same thing here the + + align:start position:0% +but it's the same thing here the + + + align:start position:0% +but it's the same thing here the +posterior foresee any theater that's not + + align:start position:0% +posterior foresee any theater that's not + + + align:start position:0% +posterior foresee any theater that's not +six is actually gonna be this guy is + + align:start position:0% +six is actually gonna be this guy is + + + align:start position:0% +six is actually gonna be this guy is +going to be equal to zero so I really + + align:start position:0% +going to be equal to zero so I really + + + align:start position:0% +going to be equal to zero so I really +don't care what this guy is so what it + + align:start position:0% +don't care what this guy is so what it + + + align:start position:0% +don't care what this guy is so what it +means is that my posterior becomes what + + align:start position:0% + + + + align:start position:0% + +it becomes so posterior PI of theta + + align:start position:0% +it becomes so posterior PI of theta + + + align:start position:0% +it becomes so posterior PI of theta +given five and seven is equal to well + + align:start position:0% +given five and seven is equal to well + + + align:start position:0% +given five and seven is equal to well +when theta is equal to is not equal to 6 + + align:start position:0% +when theta is equal to is not equal to 6 + + + align:start position:0% +when theta is equal to is not equal to 6 +this is actually 0 so we regardless of + + align:start position:0% +this is actually 0 so we regardless of + + + align:start position:0% +this is actually 0 so we regardless of +what I do here I get something which is + + align:start position:0% +what I do here I get something which is + + + align:start position:0% +what I do here I get something which is +0 and if theta is equal to 6 what I get + + align:start position:0% +0 and if theta is equal to 6 what I get + + + align:start position:0% +0 and if theta is equal to 6 what I get +is PI of 6 times P of 5 7 given 6 which + + align:start position:0% +is PI of 6 times P of 5 7 given 6 which + + + align:start position:0% +is PI of 6 times P of 5 7 given 6 which +have just computed here which is 1/4 + + align:start position:0% +have just computed here which is 1/4 + + + align:start position:0% +have just computed here which is 1/4 +divided by PI of 6 the times 1/4 so it's + + align:start position:0% +divided by PI of 6 the times 1/4 so it's + + + align:start position:0% +divided by PI of 6 the times 1/4 so it's +the ratio of two things that are + + align:start position:0% +the ratio of two things that are + + + align:start position:0% +the ratio of two things that are +identical so I get 1 so now my posterior + + align:start position:0% +identical so I get 1 so now my posterior + + + align:start position:0% +identical so I get 1 so now my posterior +tells me that given that I observe 5 and + + align:start position:0% +tells me that given that I observe 5 and + + + align:start position:0% +tells me that given that I observe 5 and +7 the theta is giving me it has to be 1 + + align:start position:0% +7 the theta is giving me it has to be 1 + + + align:start position:0% +7 the theta is giving me it has to be 1 +with probability 6 with probability 1 so + + align:start position:0% +with probability 6 with probability 1 so + + + align:start position:0% +with probability 6 with probability 1 so +now I sort of say that this thing here + + align:start position:0% +now I sort of say that this thing here + + + align:start position:0% +now I sort of say that this thing here +so now I can act this is not something + + align:start position:0% +so now I can act this is not something + + + align:start position:0% +so now I can act this is not something +that actually makes sense + + align:start position:0% +that actually makes sense + + + align:start position:0% +that actually makes sense +when I talk about frequentist confidence + + align:start position:0% +when I talk about frequentist confidence + + + align:start position:0% +when I talk about frequentist confidence +intervals I cannot really they don't + + align:start position:0% +intervals I cannot really they don't + + + align:start position:0% +intervals I cannot really they don't +really make sense to talk about + + align:start position:0% +really make sense to talk about + + + align:start position:0% +really make sense to talk about +confidence intervals given something and + + align:start position:0% +confidence intervals given something and + + + align:start position:0% +confidence intervals given something and +so now given that I observed 5 and 7 I + + align:start position:0% +so now given that I observed 5 and 7 I + + + align:start position:0% +so now given that I observed 5 and 7 I +know that the probability of data is + + align:start position:0% +know that the probability of data is + + + align:start position:0% +know that the probability of data is +equal to 1 and in this sense the + + align:start position:0% +equal to 1 and in this sense the + + + align:start position:0% +equal to 1 and in this sense the +Bayesian confidence interval is actually + + align:start position:0% +Bayesian confidence interval is actually + + + align:start position:0% +Bayesian confidence interval is actually +more meaningful so one thing I want to + + align:start position:0% +more meaningful so one thing I want to + + + align:start position:0% +more meaningful so one thing I want to +actually say about this Bayesian + + align:start position:0% +actually say about this Bayesian + + + align:start position:0% +actually say about this Bayesian +confidence interval is that it's it's I + + align:start position:0% +confidence interval is that it's it's I + + + align:start position:0% +confidence interval is that it's it's I +mean here it's equal to the value 1 + + align:start position:0% +mean here it's equal to the value 1 + + + align:start position:0% +mean here it's equal to the value 1 +right so it really encompasses the thing + + align:start position:0% +right so it really encompasses the thing + + + align:start position:0% +right so it really encompasses the thing +that we want but the fact that we + + align:start position:0% +that we want but the fact that we + + + align:start position:0% +that we want but the fact that we +actually computed it using the Bayesian + + align:start position:0% +actually computed it using the Bayesian + + + align:start position:0% +actually computed it using the Bayesian +posterior and the Bayesian rule did not + + align:start position:0% +posterior and the Bayesian rule did not + + + align:start position:0% +posterior and the Bayesian rule did not +really matter for this argument all I + + align:start position:0% +really matter for this argument all I + + + align:start position:0% +really matter for this argument all I +just said it with it had a prior but + + align:start position:0% +just said it with it had a prior but + + + align:start position:0% +just said it with it had a prior but +just what I want to illustrate is the + + align:start position:0% +just what I want to illustrate is the + + + align:start position:0% +just what I want to illustrate is the +fact that we can actually give a meaning + + align:start position:0% +fact that we can actually give a meaning + + + align:start position:0% +fact that we can actually give a meaning +to the probability of that theta is + + align:start position:0% +to the probability of that theta is + + + align:start position:0% +to the probability of that theta is +equal to 6 given that I see 5 & 7 + + align:start position:0% +equal to 6 given that I see 5 & 7 + + + align:start position:0% +equal to 6 given that I see 5 & 7 +whereas we do not really in the other + + align:start position:0% +whereas we do not really in the other + + + align:start position:0% +whereas we do not really in the other +cases and we don't have to be + + align:start position:0% +cases and we don't have to be + + + align:start position:0% +cases and we don't have to be +particularly precise in the prior on + + align:start position:0% +particularly precise in the prior on + + + align:start position:0% +particularly precise in the prior on +theta + + align:start position:0% +theta + + + align:start position:0% +theta +to be able to give data this to give + + align:start position:0% +to be able to give data this to give + + + align:start position:0% +to be able to give data this to give +this meeting okay all right so now as I + + align:start position:0% +this meeting okay all right so now as I + + + align:start position:0% +this meeting okay all right so now as I +said I think the main power of Bayesian + + align:start position:0% +said I think the main power of Bayesian + + + align:start position:0% +said I think the main power of Bayesian +inference is that it spits out the + + align:start position:0% +inference is that it spits out the + + + align:start position:0% +inference is that it spits out the +posterior distribution and not just a + + align:start position:0% +posterior distribution and not just a + + + align:start position:0% +posterior distribution and not just a +single number like frequentist would + + align:start position:0% +single number like frequentist would + + + align:start position:0% +single number like frequentist would +give you then you know we can say + + align:start position:0% +give you then you know we can say + + + align:start position:0% +give you then you know we can say +decorate our theta hat or point estimate + + align:start position:0% +decorate our theta hat or point estimate + + + align:start position:0% +decorate our theta hat or point estimate +with maybe some confidence interval + + align:start position:0% +with maybe some confidence interval + + + align:start position:0% +with maybe some confidence interval +maybe we can do a bunch of tests but at + + align:start position:0% +maybe we can do a bunch of tests but at + + + align:start position:0% +maybe we can do a bunch of tests but at +the end of the day we just have + + align:start position:0% +the end of the day we just have + + + align:start position:0% +the end of the day we just have +essentially one number all right and + + align:start position:0% +essentially one number all right and + + + align:start position:0% +essentially one number all right and +maybe we can sort of understand what the + + align:start position:0% +maybe we can sort of understand what the + + + align:start position:0% +maybe we can sort of understand what the +fluctuations of this number are in a + + align:start position:0% +fluctuations of this number are in a + + + align:start position:0% +fluctuations of this number are in a +frequentist set up but but the Bayesian + + align:start position:0% +frequentist set up but but the Bayesian + + + align:start position:0% +frequentist set up but but the Bayesian +framework is essentially giving you a + + align:start position:0% +framework is essentially giving you a + + + align:start position:0% +framework is essentially giving you a +natural method and you can interpret it + + align:start position:0% +natural method and you can interpret it + + + align:start position:0% +natural method and you can interpret it +in terms of the probabilities that are + + align:start position:0% +in terms of the probabilities that are + + + align:start position:0% +in terms of the probabilities that are +associated to the prior but you can + + align:start position:0% +associated to the prior but you can + + + align:start position:0% +associated to the prior but you can +actually also try to make some right so + + align:start position:0% +actually also try to make some right so + + + align:start position:0% +actually also try to make some right so +a vision if you give me any prior you're + + align:start position:0% +a vision if you give me any prior you're + + + align:start position:0% +a vision if you give me any prior you're +gonna actually build an estimator from + + align:start position:0% +gonna actually build an estimator from + + + align:start position:0% +gonna actually build an estimator from +this fryer maybe from the posterior and + + align:start position:0% +this fryer maybe from the posterior and + + + align:start position:0% +this fryer maybe from the posterior and +maybe it's gonna have some frequencies + + align:start position:0% +maybe it's gonna have some frequencies + + + align:start position:0% +maybe it's gonna have some frequencies +properties and that's what's really nice + + align:start position:0% +properties and that's what's really nice + + + align:start position:0% +properties and that's what's really nice +about visions is that you can actually + + align:start position:0% +about visions is that you can actually + + + align:start position:0% +about visions is that you can actually +try to give some frequencies properties + + align:start position:0% +try to give some frequencies properties + + + align:start position:0% +try to give some frequencies properties +of Bayesian with methods that are built + + align:start position:0% +of Bayesian with methods that are built + + + align:start position:0% +of Bayesian with methods that are built +using Bayesian methodology but you + + align:start position:0% +using Bayesian methodology but you + + + align:start position:0% +using Bayesian methodology but you +cannot really go the other way around if + + align:start position:0% +cannot really go the other way around if + + + align:start position:0% +cannot really go the other way around if +I give you a frequencies methodology how + + align:start position:0% +I give you a frequencies methodology how + + + align:start position:0% +I give you a frequencies methodology how +are you gonna say something about the + + align:start position:0% +are you gonna say something about the + + + align:start position:0% +are you gonna say something about the +fact that you know the Prai there's a + + align:start position:0% +fact that you know the Prai there's a + + + align:start position:0% +fact that you know the Prai there's a +prior going on etc and so this is + + align:start position:0% +prior going on etc and so this is + + + align:start position:0% +prior going on etc and so this is +actually one of the things there's + + align:start position:0% +actually one of the things there's + + + align:start position:0% +actually one of the things there's +actually some research that's going on + + align:start position:0% +actually some research that's going on + + + align:start position:0% +actually some research that's going on +for this they call it a Bayesian a + + align:start position:0% +for this they call it a Bayesian a + + + align:start position:0% +for this they call it a Bayesian a +posterior concentration and one of the + + align:start position:0% +posterior concentration and one of the + + + align:start position:0% +posterior concentration and one of the +things so there's something called the + + align:start position:0% +things so there's something called the + + + align:start position:0% +things so there's something called the +Bernstein von Mises theorem and those + + align:start position:0% +Bernstein von Mises theorem and those + + + align:start position:0% +Bernstein von Mises theorem and those +are class of theorems and those are + + align:start position:0% +are class of theorems and those are + + + align:start position:0% +are class of theorems and those are +essentially methods that tell you well + + align:start position:0% +essentially methods that tell you well + + + align:start position:0% +essentially methods that tell you well +if I actually run a Bayesian method and + + align:start position:0% +if I actually run a Bayesian method and + + + align:start position:0% +if I actually run a Bayesian method and +I look at the posterior that I get right + + align:start position:0% +I look at the posterior that I get right + + + align:start position:0% +I look at the posterior that I get right +it's gonna be something like this but + + align:start position:0% +it's gonna be something like this but + + + align:start position:0% +it's gonna be something like this but +now I try to study this in a frequentist + + align:start position:0% +now I try to study this in a frequentist + + + align:start position:0% +now I try to study this in a frequentist +point of view there's actually a true + + align:start position:0% +point of view there's actually a true + + + align:start position:0% +point of view there's actually a true +parameter theta somewhere the true one + + align:start position:0% +parameter theta somewhere the true one + + + align:start position:0% +parameter theta somewhere the true one +there's no prior for this guy this is + + align:start position:0% +there's no prior for this guy this is + + + align:start position:0% +there's no prior for this guy this is +just one fixed number is it true that as + + align:start position:0% +just one fixed number is it true that as + + + align:start position:0% +just one fixed number is it true that as +my sample size is going to go to + + align:start position:0% +my sample size is going to go to + + + align:start position:0% +my sample size is going to go to +infinity then this thing is going to + + align:start position:0% +infinity then this thing is going to + + + align:start position:0% +infinity then this thing is going to +concentrate around theta and the rate of + + align:start position:0% +concentrate around theta and the rate of + + + align:start position:0% +concentrate around theta and the rate of +concentration of this thing the size of + + align:start position:0% +concentration of this thing the size of + + + align:start position:0% +concentration of this thing the size of +this with the standard deviation of this + + align:start position:0% +this with the standard deviation of this + + + align:start position:0% +this with the standard deviation of this +thing is something that should decay + + align:start position:0% +thing is something that should decay + + + align:start position:0% +thing is something that should decay +maybe like 1 over square root of N or + + align:start position:0% +maybe like 1 over square root of N or + + + align:start position:0% +maybe like 1 over square root of N or +something like this and the rate of + + align:start position:0% +something like this and the rate of + + + align:start position:0% +something like this and the rate of +posterior concentration + + align:start position:0% +posterior concentration + + + align:start position:0% +posterior concentration +when you characterize it is called the + + align:start position:0% +when you characterize it is called the + + + align:start position:0% +when you characterize it is called the +Bernstein when mesosphere and so people + + align:start position:0% +Bernstein when mesosphere and so people + + + align:start position:0% +Bernstein when mesosphere and so people +are looking at this in some + + align:start position:0% +are looking at this in some + + + align:start position:0% +are looking at this in some +nonparametric cases you can do it in + + align:start position:0% +nonparametric cases you can do it in + + + align:start position:0% +nonparametric cases you can do it in +pretty much everything we've been doing + + align:start position:0% +pretty much everything we've been doing + + + align:start position:0% +pretty much everything we've been doing +before right you can do it for you know + + align:start position:0% +before right you can do it for you know + + + align:start position:0% +before right you can do it for you know +nonparametric regression estimation or + + align:start position:0% +nonparametric regression estimation or + + + align:start position:0% +nonparametric regression estimation or +density estimation you can do it for of + + align:start position:0% +density estimation you can do it for of + + + align:start position:0% +density estimation you can do it for of +course you can do it for sparse + + align:start position:0% +course you can do it for sparse + + + align:start position:0% +course you can do it for sparse +estimation if you want okay so you can + + align:start position:0% +estimation if you want okay so you can + + + align:start position:0% +estimation if you want okay so you can +actually compute the posterior and and + + align:start position:0% +actually compute the posterior and and + + + align:start position:0% +actually compute the posterior and and +and and and and and yeah and so you can + + align:start position:0% +and and and and and yeah and so you can + + + align:start position:0% +and and and and and yeah and so you can +think of it as being just a method + + align:start position:0% +think of it as being just a method + + + align:start position:0% +think of it as being just a method +somehow now the estimator I'm talking + + align:start position:0% +somehow now the estimator I'm talking + + + align:start position:0% +somehow now the estimator I'm talking +about so that's just the general + + align:start position:0% +about so that's just the general + + + align:start position:0% +about so that's just the general +Bayesian posterior concentration but you + + align:start position:0% +Bayesian posterior concentration but you + + + align:start position:0% +Bayesian posterior concentration but you +can also try to understand what is the + + align:start position:0% +can also try to understand what is the + + + align:start position:0% +can also try to understand what is the +property of something that's extracted + + align:start position:0% +property of something that's extracted + + + align:start position:0% +property of something that's extracted +from this posterior and one thing that + + align:start position:0% +from this posterior and one thing that + + + align:start position:0% +from this posterior and one thing that +we actually described was for example + + align:start position:0% +we actually described was for example + + + align:start position:0% +we actually described was for example +well given this guy maybe it's a good + + align:start position:0% +well given this guy maybe it's a good + + + align:start position:0% +well given this guy maybe it's a good +idea to think about what the mean of + + align:start position:0% +idea to think about what the mean of + + + align:start position:0% +idea to think about what the mean of +this thing is right so there's gonna be + + align:start position:0% +this thing is right so there's gonna be + + + align:start position:0% +this thing is right so there's gonna be +some theta hat which is just the + + align:start position:0% +some theta hat which is just the + + + align:start position:0% +some theta hat which is just the +integral of theta pi theta given X 1 xn + + align:start position:0% +integral of theta pi theta given X 1 xn + + + align:start position:0% +integral of theta pi theta given X 1 xn +so that's my posterior D theta right so + + align:start position:0% +so that's my posterior D theta right so + + + align:start position:0% +so that's my posterior D theta right so +that's the posterior mean that's the + + align:start position:0% +that's the posterior mean that's the + + + align:start position:0% +that's the posterior mean that's the +expected value with respect to the + + align:start position:0% +expected value with respect to the + + + align:start position:0% +expected value with respect to the +posterior distribution and I want to + + align:start position:0% +posterior distribution and I want to + + + align:start position:0% +posterior distribution and I want to +know how does this thing behave how + + align:start position:0% +know how does this thing behave how + + + align:start position:0% +know how does this thing behave how +close it is to a true theta if I + + align:start position:0% +close it is to a true theta if I + + + align:start position:0% +close it is to a true theta if I +actually arm if I'm in a frequency setup + + align:start position:0% +actually arm if I'm in a frequency setup + + + align:start position:0% +actually arm if I'm in a frequency setup +so that's the posterior mean but this is + + align:start position:0% +so that's the posterior mean but this is + + + align:start position:0% +so that's the posterior mean but this is +not the only thing I can actually spit + + align:start position:0% +not the only thing I can actually spit + + + align:start position:0% +not the only thing I can actually spit +out right this is definitely uniquely + + align:start position:0% +out right this is definitely uniquely + + + align:start position:0% +out right this is definitely uniquely +defined if you give me a distribution I + + align:start position:0% +defined if you give me a distribution I + + + align:start position:0% +defined if you give me a distribution I +can actually spit out its posterior mean + + align:start position:0% +can actually spit out its posterior mean + + + align:start position:0% +can actually spit out its posterior mean +but I can also think of the posterior + + align:start position:0% +but I can also think of the posterior + + + align:start position:0% +but I can also think of the posterior +median but now if this is not continuous + + align:start position:0% +median but now if this is not continuous + + + align:start position:0% +median but now if this is not continuous +you might have some uncertainty maybe + + align:start position:0% +you might have some uncertainty maybe + + + align:start position:0% +you might have some uncertainty maybe +the median is not uniquely defined and + + align:start position:0% +the median is not uniquely defined and + + + align:start position:0% +the median is not uniquely defined and +so maybe that's not something you use as + + align:start position:0% +so maybe that's not something you use as + + + align:start position:0% +so maybe that's not something you use as +much maybe you can actually talk about + + align:start position:0% +much maybe you can actually talk about + + + align:start position:0% +much maybe you can actually talk about +the posterior mode alright so for + + align:start position:0% +the posterior mode alright so for + + + align:start position:0% +the posterior mode alright so for +example if your posterior density looks + + align:start position:0% +example if your posterior density looks + + + align:start position:0% +example if your posterior density looks +like this then maybe you just want to + + align:start position:0% +like this then maybe you just want to + + + align:start position:0% +like this then maybe you just want to +summarize your posterior with this + + align:start position:0% +summarize your posterior with this + + + align:start position:0% +summarize your posterior with this +number so clearly in this case it's not + + align:start position:0% +number so clearly in this case it's not + + + align:start position:0% +number so clearly in this case it's not +such a good idea because you completely + + align:start position:0% +such a good idea because you completely + + + align:start position:0% +such a good idea because you completely +forget about this mode but maybe that's + + align:start position:0% +forget about this mode but maybe that's + + + align:start position:0% +forget about this mode but maybe that's +what you want to do maybe you want to + + align:start position:0% +what you want to do maybe you want to + + + align:start position:0% +what you want to do maybe you want to +focus on the most peak mode and this is + + align:start position:0% +focus on the most peak mode and this is + + + align:start position:0% +focus on the most peak mode and this is +actually called max maximum is a + + align:start position:0% +actually called max maximum is a + + + align:start position:0% +actually called max maximum is a +posterior + + align:start position:0% +posterior + + + align:start position:0% +posterior +as I said you maybe you want to sample + + align:start position:0% +as I said you maybe you want to sample + + + align:start position:0% +as I said you maybe you want to sample +from this posterior distribution okay + + align:start position:0% +from this posterior distribution okay + + + align:start position:0% +from this posterior distribution okay +and so in all these cases this Bayesian + + align:start position:0% +and so in all these cases this Bayesian + + + align:start position:0% +and so in all these cases this Bayesian +estimators will depend on the prior + + align:start position:0% +estimators will depend on the prior + + + align:start position:0% +estimators will depend on the prior +distribution and the hope is that as the + + align:start position:0% +distribution and the hope is that as the + + + align:start position:0% +distribution and the hope is that as the +sample size grows you won't see that + + align:start position:0% +sample size grows you won't see that + + + align:start position:0% +sample size grows you won't see that +again okay so to conclude let's just do + + align:start position:0% +again okay so to conclude let's just do + + + align:start position:0% +again okay so to conclude let's just do +a couple of experiments right so if I + + align:start position:0% +a couple of experiments right so if I + + + align:start position:0% +a couple of experiments right so if I +look at did we do this yeah so for + + align:start position:0% +look at did we do this yeah so for + + + align:start position:0% +look at did we do this yeah so for +example so let's focus on the posterior + + align:start position:0% +example so let's focus on the posterior + + + align:start position:0% +example so let's focus on the posterior +mean and we know so remember in an + + align:start position:0% +mean and we know so remember in an + + + align:start position:0% +mean and we know so remember in an +experiment one answering the example one + + align:start position:0% +experiment one answering the example one + + + align:start position:0% +experiment one answering the example one +what we had was X 1 X n that were iid + + align:start position:0% +what we had was X 1 X n that were iid + + + align:start position:0% +what we had was X 1 X n that were iid +bernal EP and the prior I put on PI on P + + align:start position:0% +bernal EP and the prior I put on PI on P + + + align:start position:0% +bernal EP and the prior I put on PI on P +was a beta with parameter AAA okay and + + align:start position:0% +was a beta with parameter AAA okay and + + + align:start position:0% +was a beta with parameter AAA okay and +if I go back to what we computed you can + + align:start position:0% +if I go back to what we computed you can + + + align:start position:0% +if I go back to what we computed you can +actually compute the posterior of this + + align:start position:0% +actually compute the posterior of this + + + align:start position:0% +actually compute the posterior of this +thing and we know that it's actually + + align:start position:0% +thing and we know that it's actually + + + align:start position:0% +thing and we know that it's actually +gonna be sorry that was uniform worse + + align:start position:0% +gonna be sorry that was uniform worse + + + align:start position:0% +gonna be sorry that was uniform worse +yeah so what we get is that the + + align:start position:0% +yeah so what we get is that the + + + align:start position:0% +yeah so what we get is that the +posterior this thing is actually going + + align:start position:0% +posterior this thing is actually going + + + align:start position:0% +posterior this thing is actually going +to be a beta with parameter a plus the + + align:start position:0% +to be a beta with parameter a plus the + + + align:start position:0% +to be a beta with parameter a plus the +sum so a plus the number of ones and a + + align:start position:0% +sum so a plus the number of ones and a + + + align:start position:0% +sum so a plus the number of ones and a +plus the number of zeros okay and the + + align:start position:0% +plus the number of zeros okay and the + + + align:start position:0% +plus the number of zeros okay and the +posterior the beta was just something + + align:start position:0% +posterior the beta was just something + + + align:start position:0% +posterior the beta was just something +that looked like the density was P to + + align:start position:0% +that looked like the density was P to + + + align:start position:0% +that looked like the density was P to +the a minus 1 1 minus P + + align:start position:0% + + + + align:start position:0% + +okay so if I want to understand the + + align:start position:0% +okay so if I want to understand the + + + align:start position:0% +okay so if I want to understand the +posterior mean I need to be able to + + align:start position:0% +posterior mean I need to be able to + + + align:start position:0% +posterior mean I need to be able to +compute the expectation of a beta and + + align:start position:0% +compute the expectation of a beta and + + + align:start position:0% +compute the expectation of a beta and +then maybe plug in a for a plus this guy + + align:start position:0% +then maybe plug in a for a plus this guy + + + align:start position:0% +then maybe plug in a for a plus this guy +a minus this guy okay so actually let me + + align:start position:0% +a minus this guy okay so actually let me + + + align:start position:0% +a minus this guy okay so actually let me +do this okay so what is the expectation + + align:start position:0% + + + + align:start position:0% + +so what I want is something that looks + + align:start position:0% +so what I want is something that looks + + + align:start position:0% +so what I want is something that looks +like the integral between 0 and 1 of P + + align:start position:0% +like the integral between 0 and 1 of P + + + align:start position:0% +like the integral between 0 and 1 of P +times a minus 1 sorry P times P a minus + + align:start position:0% +times a minus 1 sorry P times P a minus + + + align:start position:0% +times a minus 1 sorry P times P a minus +1 1 minus P B minus 1 do we agree that + + align:start position:0% +1 1 minus P B minus 1 do we agree that + + + align:start position:0% +1 1 minus P B minus 1 do we agree that +this and then there's a normalizing + + align:start position:0% +this and then there's a normalizing + + + align:start position:0% +this and then there's a normalizing +constant let's call it C okay so this is + + align:start position:0% +constant let's call it C okay so this is + + + align:start position:0% +constant let's call it C okay so this is +what I need to compute so that's C of a + + align:start position:0% +what I need to compute so that's C of a + + + align:start position:0% +what I need to compute so that's C of a +and B do we agree that this is the + + align:start position:0% +and B do we agree that this is the + + + align:start position:0% +and B do we agree that this is the +posterior mean with respect to a beta + + align:start position:0% +posterior mean with respect to a beta + + + align:start position:0% +posterior mean with respect to a beta +with parameters a and B right I just + + align:start position:0% +with parameters a and B right I just + + + align:start position:0% +with parameters a and B right I just +integrate P against the density so what + + align:start position:0% +integrate P against the density so what + + + align:start position:0% +integrate P against the density so what +does this thing look like well I can + + align:start position:0% +does this thing look like well I can + + + align:start position:0% +does this thing look like well I can +actually move this guy in here and here + + align:start position:0% +actually move this guy in here and here + + + align:start position:0% +actually move this guy in here and here +I'm going to have a plus 1 minus 1 okay + + align:start position:0% +I'm going to have a plus 1 minus 1 okay + + + align:start position:0% +I'm going to have a plus 1 minus 1 okay +so the problem is that this thing is + + align:start position:0% +so the problem is that this thing is + + + align:start position:0% +so the problem is that this thing is +actually the constant is going to play a + + align:start position:0% +actually the constant is going to play a + + + align:start position:0% +actually the constant is going to play a +big role right because this is + + align:start position:0% +big role right because this is + + + align:start position:0% +big role right because this is +essentially equal to C A plus 1 B + + align:start position:0% +essentially equal to C A plus 1 B + + + align:start position:0% +essentially equal to C A plus 1 B +divided by C a B where C a plus 1 B is + + align:start position:0% +divided by C a B where C a plus 1 B is + + + align:start position:0% +divided by C a B where C a plus 1 B is +just the normalizing constant of a beta + + align:start position:0% +just the normalizing constant of a beta + + + align:start position:0% +just the normalizing constant of a beta +ei plus 1 B so I need to know the ratio + + align:start position:0% +ei plus 1 B so I need to know the ratio + + + align:start position:0% +ei plus 1 B so I need to know the ratio +of those two constants + + align:start position:0% + + + + align:start position:0% + +and this is not something I mean this is + + align:start position:0% +and this is not something I mean this is + + + align:start position:0% +and this is not something I mean this is +just a calculus exercise so in this case + + align:start position:0% +just a calculus exercise so in this case + + + align:start position:0% +just a calculus exercise so in this case +what you get is sorry in this case you + + align:start position:0% +what you get is sorry in this case you + + + align:start position:0% +what you get is sorry in this case you +get well okay so we get essentially a + + align:start position:0% + + + + align:start position:0% + +divided by I think it's a plus B yeah + + align:start position:0% +divided by I think it's a plus B yeah + + + align:start position:0% +divided by I think it's a plus B yeah +it's a plus B so that's this quantity + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and when I plug in a to be this guy and + + align:start position:0% +and when I plug in a to be this guy and + + + align:start position:0% +and when I plug in a to be this guy and +B to be this guy but I get is a plus + + align:start position:0% +B to be this guy but I get is a plus + + + align:start position:0% +B to be this guy but I get is a plus +some of the X I and then I get a plus + + align:start position:0% +some of the X I and then I get a plus + + + align:start position:0% +some of the X I and then I get a plus +this guy a plus n minus this guy so + + align:start position:0% +this guy a plus n minus this guy so + + + align:start position:0% +this guy a plus n minus this guy so +those two guys go away and I'm left with + + align:start position:0% +those two guys go away and I'm left with + + + align:start position:0% +those two guys go away and I'm left with +qu a plus n which does not work so ya + + align:start position:0% +qu a plus n which does not work so ya + + + align:start position:0% +qu a plus n which does not work so ya +know that actually works and so now what + + align:start position:0% +know that actually works and so now what + + + align:start position:0% +know that actually works and so now what +I do I can actually divide and get this + + align:start position:0% +I do I can actually divide and get this + + + align:start position:0% +I do I can actually divide and get this +thing over there okay so what you can + + align:start position:0% +thing over there okay so what you can + + + align:start position:0% +thing over there okay so what you can +see the the reason why this thing has + + align:start position:0% +see the the reason why this thing has + + + align:start position:0% +see the the reason why this thing has +been divided is that you can really see + + align:start position:0% +been divided is that you can really see + + + align:start position:0% +been divided is that you can really see +that as n goes to infinity then this + + align:start position:0% +that as n goes to infinity then this + + + align:start position:0% +that as n goes to infinity then this +thing behaves like xn bar which is our + + align:start position:0% +thing behaves like xn bar which is our + + + align:start position:0% +thing behaves like xn bar which is our +frequentist estimator the effect of a is + + align:start position:0% +frequentist estimator the effect of a is + + + align:start position:0% +frequentist estimator the effect of a is +actually going away the effect of the + + align:start position:0% +actually going away the effect of the + + + align:start position:0% +actually going away the effect of the +prior which is completely captured by a + + align:start position:0% +prior which is completely captured by a + + + align:start position:0% +prior which is completely captured by a +is going away as n goes to infinity is + + align:start position:0% +is going away as n goes to infinity is + + + align:start position:0% +is going away as n goes to infinity is +there any question you guys have a + + align:start position:0% +there any question you guys have a + + + align:start position:0% +there any question you guys have a +question what is it + + align:start position:0% +question what is it + + + align:start position:0% +question what is it +give a question + + align:start position:0% + + + + align:start position:0% + +is it / what oh yeah yeah then I said + + align:start position:0% +is it / what oh yeah yeah then I said + + + align:start position:0% +is it / what oh yeah yeah then I said +that this is equal to this right when so + + align:start position:0% +that this is equal to this right when so + + + align:start position:0% +that this is equal to this right when so +that's four that's four a becomes a plus + + align:start position:0% +that's four that's four a becomes a plus + + + align:start position:0% +that's four that's four a becomes a plus +some of the excise and B becomes a plus + + align:start position:0% +some of the excise and B becomes a plus + + + align:start position:0% +some of the excise and B becomes a plus +n minus some of the excise okay so + + align:start position:0% +n minus some of the excise okay so + + + align:start position:0% +n minus some of the excise okay so +that's just for the posterior one this + + align:start position:0% +that's just for the posterior one this + + + align:start position:0% +that's just for the posterior one this +guy to a right so I get a plus a plus n + + align:start position:0% +guy to a right so I get a plus a plus n + + + align:start position:0% +guy to a right so I get a plus a plus n +and then those two guys cancel okay and + + align:start position:0% +and then those two guys cancel okay and + + + align:start position:0% +and then those two guys cancel okay and +that's what you have here so for a is + + align:start position:0% +that's what you have here so for a is + + + align:start position:0% +that's what you have here so for a is +equal to one-half and I claim that this + + align:start position:0% +equal to one-half and I claim that this + + + align:start position:0% +equal to one-half and I claim that this +is Jeffrey's prior because remember + + align:start position:0% +is Jeffrey's prior because remember + + + align:start position:0% +is Jeffrey's prior because remember +Jeffrey's was what well it was square + + align:start position:0% +Jeffrey's was what well it was square + + + align:start position:0% +Jeffrey's was what well it was square +roots it was proportional to square root + + align:start position:0% +roots it was proportional to square root + + + align:start position:0% +roots it was proportional to square root +of P one minus P which I can write as P + + align:start position:0% +of P one minus P which I can write as P + + + align:start position:0% +of P one minus P which I can write as P +to the one-half 1 minus P to the + + align:start position:0% +to the one-half 1 minus P to the + + + align:start position:0% +to the one-half 1 minus P to the +one-half so it's just the case a is + + align:start position:0% +one-half so it's just the case a is + + + align:start position:0% +one-half so it's just the case a is +equal to one-half + + align:start position:0% +equal to one-half + + + align:start position:0% +equal to one-half +okay so if I use Jeffrey's prior I just + + align:start position:0% +okay so if I use Jeffrey's prior I just + + + align:start position:0% +okay so if I use Jeffrey's prior I just +plug in a equals to 1/2 and this is what + + align:start position:0% +plug in a equals to 1/2 and this is what + + + align:start position:0% +plug in a equals to 1/2 and this is what +I get + + align:start position:0% +I get + + + align:start position:0% +I get +ok so those things are gonna have an + + align:start position:0% +ok so those things are gonna have an + + + align:start position:0% +ok so those things are gonna have an +impact again when n is moderately large + + align:start position:0% +impact again when n is moderately large + + + align:start position:0% +impact again when n is moderately large +for large n those things whether you + + align:start position:0% +for large n those things whether you + + + align:start position:0% +for large n those things whether you +take Jeffrey's prior or you take + + align:start position:0% +take Jeffrey's prior or you take + + + align:start position:0% +take Jeffrey's prior or you take +whatever age you prefer it's gonna have + + align:start position:0% +whatever age you prefer it's gonna have + + + align:start position:0% +whatever age you prefer it's gonna have +no impact whatsoever but if n if a if n + + align:start position:0% +no impact whatsoever but if n if a if n + + + align:start position:0% +no impact whatsoever but if n if a if n +is like of the order of 10 maybe then + + align:start position:0% +is like of the order of 10 maybe then + + + align:start position:0% +is like of the order of 10 maybe then +you're gonna start to see some impact + + align:start position:0% +you're gonna start to see some impact + + + align:start position:0% +you're gonna start to see some impact +depending on what a you want to pick + + align:start position:0% + + + + align:start position:0% + +okay and in the in the second example + + align:start position:0% +okay and in the in the second example + + + align:start position:0% +okay and in the in the second example +well here we actually computed the + + align:start position:0% +well here we actually computed the + + + align:start position:0% +well here we actually computed the +posterior to be this guy well here I can + + align:start position:0% +posterior to be this guy well here I can + + + align:start position:0% +posterior to be this guy well here I can +just read off what the expectation is + + align:start position:0% +just read off what the expectation is + + + align:start position:0% +just read off what the expectation is +right I mean I don't have to actually + + align:start position:0% +right I mean I don't have to actually + + + align:start position:0% +right I mean I don't have to actually +compute the expectation of a Gaussian + + align:start position:0% +compute the expectation of a Gaussian + + + align:start position:0% +compute the expectation of a Gaussian +it's just X n bar and so in this case + + align:start position:0% +it's just X n bar and so in this case + + + align:start position:0% +it's just X n bar and so in this case +there's actually no I mean when I have + + align:start position:0% +there's actually no I mean when I have + + + align:start position:0% +there's actually no I mean when I have +non informative fryer for a Gaussian + + align:start position:0% +non informative fryer for a Gaussian + + + align:start position:0% +non informative fryer for a Gaussian +then I have basically xn bar and so as + + align:start position:0% +then I have basically xn bar and so as + + + align:start position:0% +then I have basically xn bar and so as +you can see actually this is an + + align:start position:0% +you can see actually this is an + + + align:start position:0% +you can see actually this is an +interesting example when I actually look + + align:start position:0% +interesting example when I actually look + + + align:start position:0% +interesting example when I actually look +at the posterior + + align:start position:0% +at the posterior + + + align:start position:0% +at the posterior +it's not something that costs me a lot + + align:start position:0% +it's not something that costs me a lot + + + align:start position:0% +it's not something that costs me a lot +to communicate to you right there's one + + align:start position:0% +to communicate to you right there's one + + + align:start position:0% +to communicate to you right there's one +symbol here one symbol here and one + + align:start position:0% +symbol here one symbol here and one + + + align:start position:0% +symbol here one symbol here and one +symbol here right I tell you the + + align:start position:0% +symbol here right I tell you the + + + align:start position:0% +symbol here right I tell you the +posterior is a Gaussian with mean xn bar + + align:start position:0% +posterior is a Gaussian with mean xn bar + + + align:start position:0% +posterior is a Gaussian with mean xn bar +and variance 1 over n when I actually + + align:start position:0% +and variance 1 over n when I actually + + + align:start position:0% +and variance 1 over n when I actually +turned that into a posterior mean I'm + + align:start position:0% +turned that into a posterior mean I'm + + + align:start position:0% +turned that into a posterior mean I'm +dropping all this information I'm just + + align:start position:0% +dropping all this information I'm just + + + align:start position:0% +dropping all this information I'm just +giving you the first parameter so you + + align:start position:0% +giving you the first parameter so you + + + align:start position:0% +giving you the first parameter so you +can see there's actually much more + + align:start position:0% +can see there's actually much more + + + align:start position:0% +can see there's actually much more +information in the posterior then there + + align:start position:0% +information in the posterior then there + + + align:start position:0% +information in the posterior then there +is in the than there is in the posterior + + align:start position:0% +is in the than there is in the posterior + + + align:start position:0% +is in the than there is in the posterior +mean the posterior mean is just a point + + align:start position:0% +mean the posterior mean is just a point + + + align:start position:0% +mean the posterior mean is just a point +it's not telling me how confident I am + + align:start position:0% +it's not telling me how confident I am + + + align:start position:0% +it's not telling me how confident I am +in this point and this thing is actually + + align:start position:0% +in this point and this thing is actually + + + align:start position:0% +in this point and this thing is actually +very interesting okay so you can talk + + align:start position:0% +very interesting okay so you can talk + + + align:start position:0% +very interesting okay so you can talk +about the posterior variance that's + + align:start position:0% +about the posterior variance that's + + + align:start position:0% +about the posterior variance that's +associated to it right you can talk + + align:start position:0% +associated to it right you can talk + + + align:start position:0% +associated to it right you can talk +about as an output you could give the + + align:start position:0% +about as an output you could give the + + + align:start position:0% +about as an output you could give the +posterior mean in the posterior variance + + align:start position:0% +posterior mean in the posterior variance + + + align:start position:0% +posterior mean in the posterior variance +and those things are actually + + align:start position:0% +and those things are actually + + + align:start position:0% +and those things are actually +interesting all right so I think this is + + align:start position:0% +interesting all right so I think this is + + + align:start position:0% +interesting all right so I think this is +it so as I said in general just like in + + align:start position:0% +it so as I said in general just like in + + + align:start position:0% +it so as I said in general just like in +this case you do not the choice of the + + align:start position:0% +this case you do not the choice of the + + + align:start position:0% +this case you do not the choice of the +priors being the the impact of the prior + + align:start position:0% +priors being the the impact of the prior + + + align:start position:0% +priors being the the impact of the prior +is being washed away as the sample size + + align:start position:0% +is being washed away as the sample size + + + align:start position:0% +is being washed away as the sample size +goes to infinity just while I here + + align:start position:0% +goes to infinity just while I here + + + align:start position:0% +goes to infinity just while I here +there's no impact of the priority with a + + align:start position:0% +there's no impact of the priority with a + + + align:start position:0% +there's no impact of the priority with a +non informative one but if you actually + + align:start position:0% +non informative one but if you actually + + + align:start position:0% +non informative one but if you actually +had an informative one you know CF + + align:start position:0% +had an informative one you know CF + + + align:start position:0% +had an informative one you know CF +homework yeah yeah so CF homework you + + align:start position:0% +homework yeah yeah so CF homework you + + + align:start position:0% +homework yeah yeah so CF homework you +would actually see an impact of the + + align:start position:0% +would actually see an impact of the + + + align:start position:0% +would actually see an impact of the +prior which again would be washed away + + align:start position:0% +prior which again would be washed away + + + align:start position:0% +prior which again would be washed away +as your sample size increases here it + + align:start position:0% +as your sample size increases here it + + + align:start position:0% +as your sample size increases here it +goes away you just get xn bar over one + + align:start position:0% +goes away you just get xn bar over one + + + align:start position:0% +goes away you just get xn bar over one +and and actually in this cases you see + + align:start position:0% +and and actually in this cases you see + + + align:start position:0% +and and actually in this cases you see +that the posterior distribution + + align:start position:0% +that the posterior distribution + + + align:start position:0% +that the posterior distribution +converges to sorry the Bayesian + + align:start position:0% +converges to sorry the Bayesian + + + align:start position:0% +converges to sorry the Bayesian +estimator is asymptotically normal this + + align:start position:0% +estimator is asymptotically normal this + + + align:start position:0% +estimator is asymptotically normal this +is different from the distribution of + + align:start position:0% +is different from the distribution of + + + align:start position:0% +is different from the distribution of +the posterior right this is just the + + align:start position:0% +the posterior right this is just the + + + align:start position:0% +the posterior right this is just the +posterior mean which happens to be + + align:start position:0% +posterior mean which happens to be + + + align:start position:0% +posterior mean which happens to be +asymptotically normal but the posterior + + align:start position:0% +asymptotically normal but the posterior + + + align:start position:0% +asymptotically normal but the posterior +may not have a I mean here the posterior + + align:start position:0% +may not have a I mean here the posterior + + + align:start position:0% +may not have a I mean here the posterior +is is a beta right I mean it's not + + align:start position:0% +is is a beta right I mean it's not + + + align:start position:0% +is is a beta right I mean it's not +normal + + align:start position:0% +normal + + + align:start position:0% +normal +okay so there's different those things + + align:start position:0% +okay so there's different those things + + + align:start position:0% +okay so there's different those things +are two different things + + align:start position:0% +are two different things + + + align:start position:0% +are two different things +your question + + align:start position:0% + + + + align:start position:0% + +a unit on one right that was the + + align:start position:0% +a unit on one right that was the + + + align:start position:0% +a unit on one right that was the +improper prior yeah well I mean yeah so + + align:start position:0% +improper prior yeah well I mean yeah so + + + align:start position:0% +improper prior yeah well I mean yeah so +it's essentially telling you that right + + align:start position:0% +it's essentially telling you that right + + + align:start position:0% +it's essentially telling you that right +so we said that when you have an + + align:start position:0% +so we said that when you have an + + + align:start position:0% +so we said that when you have an +improper when you have a non informative + + align:start position:0% +improper when you have a non informative + + + align:start position:0% +improper when you have a non informative +fryer essentially the maximum likelihood + + align:start position:0% +fryer essentially the maximum likelihood + + + align:start position:0% +fryer essentially the maximum likelihood +is the maximum a-posteriori right but in + + align:start position:0% +is the maximum a-posteriori right but in + + + align:start position:0% +is the maximum a-posteriori right but in +this case there's so much symmetry that + + align:start position:0% +this case there's so much symmetry that + + + align:start position:0% +this case there's so much symmetry that +it just so happens to the maximum I mean + + align:start position:0% +it just so happens to the maximum I mean + + + align:start position:0% +it just so happens to the maximum I mean +this thing is completely symmetric + + align:start position:0% +this thing is completely symmetric + + + align:start position:0% +this thing is completely symmetric +around its maximum so it means that the + + align:start position:0% +around its maximum so it means that the + + + align:start position:0% +around its maximum so it means that the +expectation is equal to maximum 2d art + + align:start position:0% +expectation is equal to maximum 2d art + + + align:start position:0% +expectation is equal to maximum 2d art +max yeah but hence do not pick the wrong + + align:start position:0% +max yeah but hence do not pick the wrong + + + align:start position:0% +max yeah but hence do not pick the wrong +prior I mean of course it would I mean + + align:start position:0% +prior I mean of course it would I mean + + + align:start position:0% +prior I mean of course it would I mean +it would mess up to of course I mean + + align:start position:0% +it would mess up to of course I mean + + + align:start position:0% +it would mess up to of course I mean +you're putting extra information but you + + align:start position:0% +you're putting extra information but you + + + align:start position:0% +you're putting extra information but you +could say the same thing by saying well + + align:start position:0% +could say the same thing by saying well + + + align:start position:0% +could say the same thing by saying well +the issue with frequencies methods is + + align:start position:0% +the issue with frequencies methods is + + + align:start position:0% +the issue with frequencies methods is +that if you mess up the choice of your + + align:start position:0% +that if you mess up the choice of your + + + align:start position:0% +that if you mess up the choice of your +likelihood then it's gonna mess up your + + align:start position:0% +likelihood then it's gonna mess up your + + + align:start position:0% +likelihood then it's gonna mess up your +output so here you just have two chances + + align:start position:0% +output so here you just have two chances + + + align:start position:0% +output so here you just have two chances +of messing it up right you have the well + + align:start position:0% +of messing it up right you have the well + + + align:start position:0% +of messing it up right you have the well +it's going so you have the product of + + align:start position:0% +it's going so you have the product of + + + align:start position:0% +it's going so you have the product of +the likelihood and the end the prior and + + align:start position:0% +the likelihood and the end the prior and + + + align:start position:0% +the likelihood and the end the prior and +you have one more chance to to but it's + + align:start position:0% +you have one more chance to to but it's + + + align:start position:0% +you have one more chance to to but it's +true if you assume that the model is + + align:start position:0% +true if you assume that the model is + + + align:start position:0% +true if you assume that the model is +right and of course finding the wrong + + align:start position:0% +right and of course finding the wrong + + + align:start position:0% +right and of course finding the wrong +prior could completely mess up thing if + + align:start position:0% +prior could completely mess up thing if + + + align:start position:0% +prior could completely mess up thing if +your prior for example has no support on + + align:start position:0% +your prior for example has no support on + + + align:start position:0% +your prior for example has no support on +the true parameter but if your prior has + + align:start position:0% +the true parameter but if your prior has + + + align:start position:0% +the true parameter but if your prior has +a positive weight on the true parameter + + align:start position:0% +a positive weight on the true parameter + + + align:start position:0% +a positive weight on the true parameter +as n goes to infinity you know I mean + + align:start position:0% +as n goes to infinity you know I mean + + + align:start position:0% +as n goes to infinity you know I mean +okay I cannot speak for all counter + + align:start position:0% +okay I cannot speak for all counter + + + align:start position:0% +okay I cannot speak for all counter +examples in the world but I'm sure under + + align:start position:0% +examples in the world but I'm sure under + + + align:start position:0% +examples in the world but I'm sure under +minor technical conditions you can + + align:start position:0% +minor technical conditions you can + + + align:start position:0% +minor technical conditions you can +guarantee that your posterior mean is + + align:start position:0% +guarantee that your posterior mean is + + + align:start position:0% +guarantee that your posterior mean is +gonna converge to what you needed to + + align:start position:0% +gonna converge to what you needed to + + + align:start position:0% +gonna converge to what you needed to +convert to any other question + + align:start position:0% + + + + align:start position:0% + +all right so I think this sort of closes + + align:start position:0% +all right so I think this sort of closes + + + align:start position:0% +all right so I think this sort of closes +the more traditional mathematical not + + align:start position:0% +the more traditional mathematical not + + + align:start position:0% +the more traditional mathematical not +mathematical but you know traditional + + align:start position:0% +mathematical but you know traditional + + + align:start position:0% +mathematical but you know traditional +statistics part of this class and from + + align:start position:0% +statistics part of this class and from + + + align:start position:0% +statistics part of this class and from +here on we'll talk about more + + align:start position:0% +here on we'll talk about more + + + align:start position:0% +here on we'll talk about more +multivariate statistics starting with + + align:start position:0% +multivariate statistics starting with + + + align:start position:0% +multivariate statistics starting with +principal component analysis so that's + + align:start position:0% +principal component analysis so that's + + + align:start position:0% +principal component analysis so that's +more like when you have multiple data we + + align:start position:0% +more like when you have multiple data we + + + align:start position:0% +more like when you have multiple data we +started in a way to talk about + + align:start position:0% +started in a way to talk about + + + align:start position:0% +started in a way to talk about +multivariate statistics when we talked + + align:start position:0% +multivariate statistics when we talked + + + align:start position:0% +multivariate statistics when we talked +about multivariate regression but we'll + + align:start position:0% +about multivariate regression but we'll + + + align:start position:0% +about multivariate regression but we'll +move on to you know principal component + + align:start position:0% +move on to you know principal component + + + align:start position:0% +move on to you know principal component +analysis I'll talk a bit about multiple + + align:start position:0% +analysis I'll talk a bit about multiple + + + align:start position:0% +analysis I'll talk a bit about multiple +testing I haven't made my mind yet about + + align:start position:0% +testing I haven't made my mind yet about + + + align:start position:0% +testing I haven't made my mind yet about +what we'll talk really in December but I + + align:start position:0% +what we'll talk really in December but I + + + align:start position:0% +what we'll talk really in December but I +want to make sure that you have a taste + + align:start position:0% +want to make sure that you have a taste + + + align:start position:0% +want to make sure that you have a taste +and the flavor of what you know is being + + align:start position:0% +and the flavor of what you know is being + + + align:start position:0% +and the flavor of what you know is being +interesting in statistics these days + + align:start position:0% +interesting in statistics these days + + + align:start position:0% +interesting in statistics these days +especially as you go towards more + + align:start position:0% +especially as you go towards more + + + align:start position:0% +especially as you go towards more +machine learning type of questions where + + align:start position:0% +machine learning type of questions where + + + align:start position:0% +machine learning type of questions where +really the focus is on prediction rather + + align:start position:0% +really the focus is on prediction rather + + + align:start position:0% +really the focus is on prediction rather +than the modeling itself I will talk + + align:start position:0% +than the modeling itself I will talk + + + align:start position:0% +than the modeling itself I will talk +about logistic regression as well for + + align:start position:0% +about logistic regression as well for + + + align:start position:0% +about logistic regression as well for +example which is and generalized linear + + align:start position:0% +example which is and generalized linear + + + align:start position:0% +example which is and generalized linear +models which is just the generalization + + align:start position:0% +models which is just the generalization + + + align:start position:0% +models which is just the generalization +in the case that Y does not take value + + align:start position:0% +in the case that Y does not take value + + + align:start position:0% +in the case that Y does not take value +in the whole real line may be 0 1 for + + align:start position:0% +in the whole real line may be 0 1 for + + + align:start position:0% +in the whole real line may be 0 1 for +example for regression all right thanks \ No newline at end of file diff --git a/k2jN_26m8LM.txt b/k2jN_26m8LM.txt new file mode 100644 index 0000000000000000000000000000000000000000..9fc630d8693d3283309d1249f42c38998bd080ef --- /dev/null +++ b/k2jN_26m8LM.txt @@ -0,0 +1,4377 @@ +OK. + +Good morning everyone. + +As I mentioned at the last lecture, we're +now moving into the nitty-gritty of the subsystems. + +And we have quite an extraordinary list of +speakers who actually worked on the original + +design of these systems. + +And, as Professor Cohen mentioned, not only +did they design these systems for the shuttle + +but, in most cases, they came from having +designed essentially the same systems on the + +Apollo program. + +So, in the question and answer period, if +there are some things that you'd like to know + +about the comparison of Apollo and Shuttle, +and also any questions about the future since + +some of you will be writing up possibilities +for future development of some of these systems, + +please ask the questions. + +And I spoke with Tom Moser, and he's fully +prepared to handle questions during the talk. + +Because there will be a lot of fairly detailed +technical stuff, so if there's something that + +you're not familiar with, you don't understand +or just have questions about, please ask while + +the lecture is going on. + +I want to remind you, we have fairly extensive +bios for all the speakers. + +Rather than take the time in class to read +through this, I've posted them all on the + +class website. + +So my suggestion is go to the class website +before each class and just see the background + +of the lecture. + +Professor Cohen is going to make some personal +remarks about, well, whatever it is that you + +want to say about our speaker. + +Before we go into that, two things. + +Tom Moser asked me if we had this book. + +This actually is my personal copy. + +I'm going to put it on reserve. + +We may actually have it in the library as +well. + +I'll check, and I'll make sure that this gets +on reserve. + +This really is a rather complete book. + +A lot the material that you've seen, the early +design of the shuttle is in here, discussions + +of subsystems, and then detailed discussions +of the individual flights all the way up through + +the first hundred shuttle flights. + +It's a very nice resource, and we'll have +it on reserve in the library. + +The next thing. + +I believe I have now indications from everybody +about what you want to do your paper on. + +We have two groups doing GN&C. + +One group doing displays and controls. + +We had two small groups interested in the +propulsion system. + +And I've asked Brian and other people, you've +gotten together? + +OK. + +Only one person, Dan, I think, indicated an +interest in the thermal protection system. + +I know we've got a lot people on GN&C. + +One of you, I think, had actually indicated +an interest in thermal protection. + +I will leave that up to you. + +If somebody would like to work on thermal +protection with Dan, he's back there and is + +available, I guess. + +We have one group which is going to do a little +bit of a different sort of project on modularity + +and some of the design methods that went into +the shuttle compared to modern techniques + +that are available now, so we'll be interested +in seeing what you'll come up with. + +And then we had a group that wants to look +at the propulsion system, but from the point + +of view of fuel storage and what the system +would have looked like if we had possibly + +used alternate fuels. + +We've got a nice spectrum of things that people +will look at. + +Any time you'd like to come and talk with +me, with Professor Cohen or take advantage + +of one of the speakers who happens to be talking +about the area that you're interested in, + +please do that. + +We do have time usually after class, if you're +free. + +The speakers will generally be available so +take advantage of it. + +OK. + +That's enough talking from me. + +Aaron, I'll give this to you.. + +I just have a few personal comments about +Mr. Moser. + +He is going to talk to you today, lecture +you today about the structures on the space + +shuttle. + +But Tom, as Jeff mentioned, did the same work +on the Apollo program. + +I was the manager of the Command and Service +Module on Apollo and on the Space Shuttle + +Orbiter, so Tom and I have been working tighter +for many years. + +And I relied very, very heavily on Tom throughout +the years. + +I told a little anecdote the other day, and +just let me say it again because the person + +that helped me with it is Tom Moser. + +During one of the shuttle missions, we were +getting ready to come back, about 11:00 at + +night, I was getting ready to leave my house +to go to the Control Center, which I live + +about ten minutes away, and we were getting +ready to make the de-orbit burn, I got a call + +from Rockwell International, their head of +the program there. + +And he said, Aaron, we just did this test. + +We took the panel of tiles and dumped it into +a bucket of waterproofing agent and all the + +tiles came off. + +I said what do you want me to do with that +information? + +I said they're getting ready to come back +and there's not much I can do about that. + +You're telling me all the tiles are going +to come off? + +He said no, they're not because that's not +really what we did on the shuttle. + +I said well, why did you do that test? + +That's sort of a dumb test. + +I had a decision to make, whether I'd call +the people in the Control Center like Chris + +Kraft and tell him we did this test and all +the tiles are going to come off. + +But we've got to come back. + +I decided what I would do is call my good +colleague Tom Moser. + +I said Tom, what should we do? + +We talked for a while and talked for a while, +and we decided to keep this information to + +ourselves until after the landing. + +It turns out it all worked out fine. + +There were no problems. + +But my point to you is that how much I relied +on Tom. + +The other point is you may find yourself in +that type of situation some day on a project + +maybe not associated with that. + +Tom turned out to be afterward my Deputy Manager +in the Orbiter Project Office. + +Then he went on to become Head of Engineering +at the Johnson Space Center and then went + +on to be Director of the Space Station in +Washington, DC and now is a consultant. + +So, with no further ado, let me turn it over +to Tom. + +One thing I learned to do is have my own mic +because Aaron will keep it. + +One of the advantages to having a gray beard, +besides some of the folks in the back, is + +I'm not going to refer to him as Professor +Cohen or as Professor Hoffman. + +It's Jeff and Aaron. + +It's not out of disrespect. + +It's just the way I grew up so that's OK to +do. + +When Aaron asked me to do this, and Jeff, +I thought that's easy, I'll just pull out + +some of my old notes and stuff like that and +I will be up the next day. + +Until Jeff sent me the syllabus and what it +was to do, it made me start thinking about + +what I'd spent a good part of my life doing. + +And that was designing and development of +the shuttle with Aaron and some of the others, + +but from a systems engineering perspective +which you guys are doing. + +So, what I did is I went back and looked at +everything from a systems engineering point + +of view from 1968 all the way until '81 when +the shuttle flew. + +But I looked at it through the knothole of +a structure and thermal person. + +So, that's what I'm going to present to you +today. + +And, as you go through each phase of the program +it changes. + +And sometimes it's down to the minute detail +and other times it is the macro. + +That's my objective, and I hope we accomplish +that. + +Ask me any questions any time that you want +to. + +Just a little bit of credit and recognition +of some of the people that made this thing + +happen. + +You're going to hear from a lot of these people. + +You won't hear from John Yardley or Max Faget +because they are deceased now, but these people + +up here made this program go. + +And then you will have also some references +that give you a lot more detail than I'm going + +to give you today, even though I'm going to +cover a lot of it. + +There is one unique thing about a program +like this that is complex. + +And that is the technical team and the management +team have to work together and get together. + +Everybody that is listed up there stayed on +this program from day one, and that is key. + +I don't think there has been a program since +then that that has happened. + +And I think that if people judge the Shuttle +Program as being successful, I think that + +that's a major contribution to that success. + +Beginning in '68 when the concept studies +began, all the way down to operations from + +a structural perspective, what is important +at each one of those phases in its weight + +and cost and produceability from day one. + +But then it gets into the certification phase, +the last part of the program, how are you + +going to certify this thing? + +How are you going to prove that it's good +for flight? + +How are you going to prove that the crew is +safe? + +And you have to do it on the ground. + +So, it's a completely different knothole you're +looking through and a completely different + +set of parameters. + +I didn't start on Apollo at the beginning +like Aaron did. + +I came out a little bit later. + +But, in this program, I had the good fortune +of working on it from sketchpad to launch + +pad. + +And that's the way I characterized it. + +And Aaron didn't know this, but at the end +I would have worked for free to complete the + +program because I was going to see something +from beginning to end. + +And so if you ever had that opportunity to +get on the program at the very beginning, + +I don't care what knothole you're looking +at it through, stay on that program if you + +can because it's a completely different life +at every step along the way. + +So, from the knothole of Orbiter structure, +I'm going to break this thing into two pieces, + +Orbiter structure and the thermal protection +system.. + +On the concept studies that began in '68, +what was the objective of those concept studies? + +Conceiving, characterizing and characterizing +by qualitative and quantitative concepts that + +would appear to work. + +So, it was determining really the feasibility +of the concepts. + +When that began, the only requirement in the +Shuttle Program was to have a reusable space + +transportation system. + +Get something that goes from earth to low +earth orbit and back reliably and reusable. + +There wasn't a requirement on payload size, +there wasn't a requirement on number of missions, + +there wasn't a requirement on any of those +things. + +That's what it was. + +The variables that we all looked at, though, +were budgets, yearly budgets, developments + +costs, operations cost. + +And you'll see, as you go through some of +this stuff, and probably some of the stuff + +that Dale Myers showed you, is development +cost, you can spend a lot of money on development + +and reduce the operations cost or you can +spend a little bit of money on development + +and have very high operational cost. + +So, there's a trade there. + +And when you're dealing with budgets that +you really don't understand exactly what they + +are, that's a very important variable. + +Payload mass and size is important from a +structural and thermal standpoint because + +it has to do with mass and it has to do with +energy that has to be dissipated during reentry. + +The operational orbit is important. + +Fully reusable flight systems or partially +reusable, and that's a trade on cost and weight. + +Turnaround time and cross-range. + +Cross-range was critical to us at this point +because NASA didn't have a requirement for + +cross-range. + +And that's cross-range after you come back +into the atmosphere to be able to deviate + +your normal ballistic trajectory coming back +in. + +But the Air Force thought that they had a +requirement so we had to include that. + +And then, as we got into the next phase of +it, looking at what was important from a structural + +standpoint is the efficiency of the load path, +the weight, the payload size, the aerodynamic + +surface loading, now we're beginning to get +in and look at what are the wing loads, et + +cetera, and how does that manifest itself +in weight and produceability? + +We did that under two years of contracted +effort. + +Then within JSC, the Johnson Space Center, +which was formally the Manned Space Craft + +Center, we conceptionally looked at designs +in-house. + +And we looked at 53 different designs. + +You talk about a systems engineering thing, +what we did was got a group of people about + +the size of this room and went away and locked +ourselves up. + +But we had expertise in every area, propulsion, +guidance and control, aerodynamics, aero heating, + +that kind of stuff. + +And we were almost doing a configuration a +week when we did that. + +So, when you look at 53 different configurations +over basically a two-year period, we were + +not only just looking at it but we were quantifying +then, what it meant in terms of all the parameters + +that I showed you a while ago. + +How much did it cost? + +What was the development cost? + +What was the operations cost? + +What was the weight? + +What was the maximum temperature as we saw +on the vehicle? + +Was there a thermal protection system that +could accommodate those types of temperatures? + +That was the characterization in the systems +engineering parameters that we used. + +Tom, where these designs kind of refined? + +Were you refining with each iteration or was +it like we'll try this for a couple iterations + +and then maybe try something completely different? + +Were you working towards a final [OVERLAPPING +VOICES]? + +Well, what we were doing was looking at the +variables. + +In other words, like here, when we looked +at 53 different things, we looked at payloads + +ranging anywhere from 15,000 to 40,000 pounds. + +We didn't know what the answer was going to +be. + +The driving thing there was reusability and +cost profile. + +We thought we knew what we could afford to +do. + +We looked at payloads from 8 feet in diameter +to 15 feet in diameter, 30 feet long to 75 + +feet long. + +We were looking at all of those things. + +And, as we did that, we changed configuration +from a straight wing, which is not good for + +cross-range, to a delta wing which is better +for a cross-range, to a double delta wing + +which is even more structurally efficient. + +Landing weights then was important. + +Just like everybody saw the plane landing +last night, it had to get that landing weight + +down to where it could control it. + +Well, that was the same thing we were doing. + +We were looking at landing weights, not only +from a controllability but also from a produceability. + +We looked at weights from 70,000 to 215,000 +pounds, boosters from fully reusable to partially + +reusable, propulsion systems and various types +of things. + +We even looked at air breathers so that they +didn't have to come back a dead stick like + +they do now when Jeff was in the vehicle. + +And pressure fed and pump fed systems. + +There was simplicity and complications in +all of them. + +Tankage, internal or external to the Orbiter. + +Could you maybe say, for people's benefit +here who have grown up in the computer age, + +something about the tools that you had? + +I am going to do that in a minute. + +You are, OK. + +I'm going to give you a challenge, too. + +So, we looked at all of those. + +And, we not only looked at it, we quantified +it to the extent that we could get the first + +order estimates on what the cost in all those +things where. + +Now then, I chose a couple of them here. + +This was one of the early designs of the Orbiter. + +Look where the locks and hydrogen are. + +It's inside the Orbiter. + +It has a straight wing so it was fairly lightweight, +except for having to carry all that tankage. + +The engines were on the Orbiter itself, but +the payload was really small. + +Very low cross-range, very low payload. + +So that was probably the 8 foot diameter 40,000 +pound payload. + +We evolved that over a series of studies until +we finally got down to about February of '72 + +where we said we're going to have to have +a larger payload than this. + +And the cost profile didn't fit. + +What we did is we came up with a configuration +that's almost like the shuttle that you see + +today. + +Large payload, all the propulsion systems, +the main propulsion systems are outside the + +Orbiter. + +And it's a fly back, and part of it was throwaway. + +In this case, we had a booster in line with +the external tank rather than in parallel + +with it like the SRBs are today. + +Basically that's what we started the detailed +design and development with, but not exactly. + +And I'll show you that. + +Now then, some of us who like to worry about +load pass and simplicity and low weight of + +the structure, we said ah-ha. + +What we will do is put the engines on the +external tank. + +All the mass is down here. + +Very little mass up here. + +And for boost reduce the weight of the Orbiter, +which is going to reduce development and operations + +costs a whole bunch and thermal protection +system, but we have to swing these engines + +for reusability from the external tank back +up the Orbiter and stow them for entry. + +Well, our brother in mechanical engineers, +they beat us pretty hard. + +They beat us black and blue. + +Anyway, that was a concept that we looked +at very late in the program. + +And that didn't go anywhere, even though Max +Faget and I wanted to do it pretty badly. + +As we continue now. + +Now we're four years into the thing, we've +done all these systems engineering analysis, + +so we end up with a final concept. + +Here's what we want. + +We want a 2.5 stage launch vehicle because +it costs too much basically to fly back the + +booster. + +We just didn't have the money so we said we +want to have the most important part be fully + +reusable, so that was the Orbiter. + +It was going to be a delta wing. + +We figured that the mission life, we had a +mission model of 500 total missions, 100 missions + +per vehicle, and there were five vehicles. + +We had an ascent acceleration of 3 g's. + +Why was that? + +Really, the requirement was to keep down the +inertia loads, but it was also to let people + +off the street flying the thing. + +Go ahead. + +What constitutes half a stage? + +Half a stage means that the external tank +is like a half a stage. + +The SRB is a stage, the engine, the Orbiter +is a stage, but the tank is a half a stage. + +We kept the max dynamic pressure down because +that was a major driver for control systems + +and for aerodynamic services. + +You would love not to have the wings on the +Orbiter going uphill. + +That's a penalty that you pay. + +So, one of the things to help reduce that +is to keep that aerodynamic load down on the + +wings. + +Then for atmospheric flights, and I'm going +to talk a little bit more about that, we said + +this thing is going to come back like an airplane. + +Let's fly it. + +Let's design it like an airplane 2.5 g normal +maneuver load factor and a negative 1 g. + +A crew of four for one week. + +That becomes kind of important because that +sized the crew module, that sized a lot of + +the environmental control systems you'll hear +about later and other things in the life support + +systems. + +So, without a lot of changes, to show you +what the flexibility and capability of this + +vehicle is, the Orbiter is now flying seven +people for two weeks. + +So, it went from 28 man days to 63 man days +basically. + +And I don't think a lot of people understand +what that has done. + +And there is a lot more robustness in the +Orbiter, in the shuttle system that was not + +designed into it but had some inherent capability. + +And also some of it was a little bit of forethought +in the thing. + +Here comes the Air Force stuff. + +65,000 pounds up. + +40,000 pounds return. + +That was the requirements. + +15 x 60. + +Another important thing is we didn't know +what they'd be but maybe up to five payloads + +at a time. + +And that's going to become a problem, I'll +show you about in a minute, as we start peeling + +this systems engineering onion of getting +down into the details. + +And deployable payloads. + +Cross-range. + +A little less than 1300 nautical miles cross-range. + +TPS material. + +We didn't know what the hell it was going +to be, but that's what we started with. + +So, we began the contract for design, development, +test and evaluation. + +NASA does pretty good stuff in-house. + +And I think with Dr. + +Mike Griffin at the helm now you're going +to see a lot more of that coming into NASA + +where they're doing a lot of stuff in-house. + +But when it gets down to doing the detail, +design and manufacturing and cost-control, + +down to the detailed parts and manifesting +everything around, that's where the contract + +is. + +NASA doesn't have that capability in a large +program. + +So, this is where we gave a contract to Rockwell +International. + +They had the integration contract. + +And another company, Martin, had the external +tank. + +[Backhaul?] had the SRBs. + +And who else am I missing? + +And Rockwell had the integration and Orbiter +contract, both. + +This is what they started with. + +That was their authority to proceed configuration, +even though this is shown as in 1972. + +But you see there is very little difference +in the configuration then and what the configuration + +is today. + +There was some minor mods which are not worthy +of even talking about right now. + +But let me give Aaron a lot of credit. + +His favorite word, the whole time he was the +project manager, was no. + +And he had above his blackboard better is +the enemy of good. + +We've got something. + +We know it will work. + +We knew that damn configuration would work. + +And Aaron got inundated with people coming +back after we started the program. + +Aaron, if you put reaction control jets out +on the wing tips and here and up on the vertical + +stabilizer you get a lot more control authority. + +And when you guys start looking at this guidance +and control stuff in propulsion you're going + +to come up with that. + +But it complicated the entry in the thermal +protection system. + +It complicated getting the fuel to those things, +so Aaron said no, no, no. + +And the astronauts would come in. + +They'll always meet with Aaron at 7:00 in +the morning because that's when they would + +get their word in. + +And so they would have to go do flight training +or something like that. + +And, as they walked out the door, Aaron would +say no. + +They didn't hear him, but it was always no. + +And that was critical in this thing. + +And so the program came in at $5.1 billion. + +It started $5.1 billion. + +It came in at $5.1 billion. + +It was only because of being able to say no. + +But to say no you better do a good systems +engineering job at the beginning. + +And were there some faults and errors? + +Yeah. + +I'll confess and open my kimono here on the +few of the things, but all in all it wasn't + +too bad. + +And I will say one other thing about systems +engineering. + +It was interesting to watch four or five different +large companies look at the various concepts. + +I can say this now because none of these companies +even exist in the form that they were then. + +Grumman had a very large systems engineering +organization. + +Rockwell had a very small systems engineering +organization, almost down to one or two people, + +but they were extremely good. + +They were extremely good systems engineers. + +NASA went with Rockwell for a number of reasons, +but one of the things that probably benefited + +the program was having a very concentrated +set of engineering requirements coming out + +of a systems engineer which almost turned +out to be one guy, Ed Smith. + +And he was very, very good at that. + +The reason I bring that up to you, the thing +that's most defficient, from my perspective + +now in the United States today, are good systems +engineers. + +Very good thermal engineers, good structural +engineers, good propulsion engineers. + +There are very few systems engineers that +are good. + +If you make a note of that and become one +of those, you'd be highly sought after. + +So, a little bit of this is a repeat. + +As we went into these requirements, and from +a government system's perspective, now the + +challenge was to give the contractor the requirements +that they need but don't over-specify the + +requirements. + +We were very careful to say here are the top +level requirements, don't ask us what the + +internal loads on the wing are because we're +not going to tell you what that is. + +That is for you to decide. + +And, if you want to change something within +these constraints, you can change it. + +But the burden is on you to make everything +else right. + +That is something that I think the Orbiter +did probably better than the external tank. + +I'll just say it like it is. + +Go ahead. + +I'm just wondering, sir, what happened to +the canard configuration with the delta wing? + +What happened to it? + +Yeah. + +It was not selected. + +And I don't remember why it was not selected. + +What was driving it, I don't know. + +I don't have those notes anymore. + +It could have been cross-range. + +I don't remember that particular configuration, +if it had the required cross-range for the + +payload mass. + +I just don't remember. + +I don't think it would have been cost. + +I think it was a lot of complexity. + +Well, it did have complexity so it had to +add some cost. + +Weight-wise, it probably was not too different +just because of the control authority of having + +the canards there. + +But that's a good question. + +Tom, you might mention [UNINTELLIGIBLE PHRASE]. + +I'm going to touch on that, again, a little +bit in a minute about what we did in surveying + +and determining the loads. + +And let me hold that if I can. + +Now we have begun with the design.. + +When you use the term top level requirements, +what does the top level refer to as opposed + +to just requirements or performance requirements? + +Well, the top level requirement changes as +the phase changes. + +The very beginning, in '68, the top level +requirement was a transportation system. + +We don't know what it's going to be, reusable, +and we don't know how much payload it is going + +to have to carry. + +So, that was the top level requirement. + +Then it was to look at all of the combinations +of things that you could create. + +The solution was it is feasible and we think +that this is about what it's going to cost. + +Now, as we get into this point, these are +the top level requirements. + +So, the granularity of the requirements increases +as the program advances. + +Good question.. + +For the challenges, now I'm going to call +it the challenges of beginning this thing, + +we know what the configuration is, you know +what the design life is, et cetera, all that + +kind of stuff, but we still haven't decided +on what the material of the airframe is going + +to be. + +We estimated some stuff because it could be +aluminum or it could be titanium and this + +is what it would be. + +And it all fits within the right cost and +performance envelopes, but let's optimize + +that from a systems standpoint a little bit +and see what that is. + +Some of the challenges in structural design, +and I'm going to talk about each one of these + +things that's listed on here separately, should +the cabin be an integral part of the fuselage + +or should it be a pressure vessel floating +within the fuselage? + +Trade to be made. + +How are we going to account for thermal stress +in this? + +Well, what the hell is thermal stress? + +Apollo, we didn't care a whole lot about thermal +stress. + +It really wasn't an issue, not to the extent +that a vehicle like this is. + +It was very sensitive for thermal stress. + +Compartment venting. + +We'll talk more about that. + +Major structure concept trades to reduce weight +basically. + +And then how in the hell do we get the design +loads on this thing? + +From a structural design criteria we said, +well, let's start with 1.5. + +That's what all airplanes are designed for +so we'll do that. + +Even though some of the boosters were designed +for 1.25. + +Does everybody know what an ultimate factor +safety is? + +That's the allowable of the material that +you've decided to use compared to the maximum + +expected load that you will ever want to see, +three sigma kind of loads. + +And then whatever the factor is about that, +that's the factor of safety. + +So, you simply take the maximum loads you +can expect to find, multiply it by 1.4 and + +it better meet what the allowable is. + +If there's margin in that allowable then that's +called a design margin. + +Ideally, you would like to have zero margin. + +That still gives you a 40% factor of safety. + +Everybody with me? + +Yield is classically something that you decided +on material. + +Well, I want to also have a factor safety +on yield. + +And we sat around and asked ourselves why +the hell do we care about that? + +The only thing you don't want it to do is +you don't want it to deform such that it won't + +operate so doors won't open, hinges won't +work, et cetera. + +We did not impose that on the program of the +yield factor safety. + +We didn't on the Orbiter. + +The external tank did. + +And they paid a weight for that because if +you put a 1.2 factor safety on yield for some + +materials, that gives you a lower allowable +than an ultimate factor safety when you're + +really only interested in ultimate strength. + +And then we had said thermal stress is going +to be important, but we don't want to be so + +conservative that we let the thermal stress +add in such a way that it adds conservatism. + +But, at the same time, we don't want it to +count on it if it's relieving when we cannot + +really rely on it to be there. + +So, it is decreasing from the stress point +of view. + +A scatter factor of four on life for a hundred +missions. + +What is scatter factor? + +Scatter factor just means a factor of four. + +If you have 10,000 cycles at 20,000 psi stress +then you have to certify it for 40,000 cycles. + +Typically, most airplanes you fly around on, +they have a design life of about 20,000 flight + +hours. + +I think that's about right. + +They are fatigue tested to 80,000 flight hours +to make sure that they have that kind of factor + +on life. + +And then we said well, this thing is going +to be used a lot, we've never looked at that + +before so we will arbitrarily say we'll use +a 1.2 factor at the end of life or ultimate. + +And then these are just classical engineering +material allowables that everybody uses today. + +A lot of people have mentioned lately, as +we were thinking of the end of the life of + +the shuttle, that although it was designed +for a hundred missions, I guess it was always + +assumed that those hundred missions would +be flown over the course of just a few years. + +And so, I think it's true, you more concerned +with the long-term effects of stress than + +things like weathering or being exposed to +salt, air over 20 years. + +Is that correct? + +Well, you hit a very key point. + +And you're exactly right. + +It turns out a hundred missions wasn't really +designing anything. + +I mean it could have. + +Well, as a matter of fact, it didn't. + +I don't know of anything. + +A hundred missions design is for a cyclic +stress, high cycle, low stress fatigue or + +low cycle high stress. + +It didn't. + +But the environment sitting around or the +life of the material exposed has. + +The leading edge turned out to be there is +a degradation in the strength of the leading + +edge material, the carbon-carbon material +because of being exposed to the conditions. + +There was some corrosion found in the wings +during an inspection. + +Nothing was wrong with the low carrying capability, +except it was beginning to corrode. + +[UNINTELLIGIBLE PHRASE] You've got me mixed +up with somebody else. + +I'm not talking about avionics. + +[LAUGHTER] No, but it's true. + +There, I think, just to bring that up, the +idea was they would not be good for that length + +of time so change them out, we're going to +have to upgrade them anyway. + +Aaron, I think, just left being program manager +when they decided to change,no you still were + +there, they decided to change the general-purpose +computers. + +It took ten years to change the general-purpose +computers because of all the certification. + +Did the use and safety factors, like what +numbers you were using, how much did the Apollo + +program [UNINTELLIGIBLE PHRASE] aircraft safety +factors? + +The Apollo program was like 1.2 factor of +safety, as I recall, because it was a single + +use item. + +And I'm going to take the opportunity to go +back and verify that, but I think that's was + +right for some conditions. + +And it could have been 1.5 on others. + +I know on pressure alone it was 1.5 psi. + +You say, well, why was it different for pressure +than it was for others? + +Because there was some historical data there +that NASA had that said that was the right + +thing to use. + +But that's a good question. + +Now you've caught me. + +I can remember on the boosters it was 1.25, +but on the command module itself, let me retract + +that, it was probably 1.5. + +It was 1.25 on the boosters and 1.5 on the +crude part of the vehicle. + +One of the challenges that we had here was +to establish a criteria. + +These were our objectives. + +To assure that there was a realistic stress +that we're putting in the vehicle and we weren't + +being overly conservative with it. + +We were not reducing the stress because of +thermal gradients. + +And then we were incorporating the classical +pressure induced stress. + +And now what were the details of that? + +Here were the details. + +We came up with this algorithm that says we +will use a factor of 1.4 on all external loads + +because that's aerodynamic loads, inertia +loads and so forth. + +We will use a factor of 1.4 on the thermally +induced loads, if you will. + +They are really thermally induced strains +and stress. + +We'll use a 1.4 factor on that if it's additive +to the mechanical, but if it's subtractive + +we'll only use one because we probably won't +reach the maximum thermal conditions so you + +cannot rely on that. + +On pressure, we used 1.4. + +Unless it was pressure alone, we used 1.5. + +But the whole thing is we would never have +less than 1.4 of the total combined load. + +So, that's what we did. + +And so you say why in the hell did you do +that? + +Why did you have to go to that kind of detail? + +The reason being is because you probably had +about 30,000 stress engineers working on the + +program, and they needed to know how to combine +this stuff. + +If you didn't, this guy is going to do one +thing and this guy is going to do something + +different. + +We got it down to that level to save weight +in the vehicle and save complexity in the + +vehicle. + +Well, we have our criteria set now. + +Let me give one more story on marginal safety. + +One of the people that I showed you at the +top of the credits list was John Yardley. + +And probably Aaron and Larry Young and other +people would probably agree with this, John + +Yardley is probably the best engineer that +I ever knew in my entire life. + +He's probably one of the best managers I ever +knew. + +John Yardley had the job of being the Program +Manager on McDonnell Douglas F4 aircraft. + +And he was an old stress guy. + +He knew that weight was going to be a critical +parameter in the success of that program and + +he had to keep the weight out. + +What he did, on that previous slide where +I showed you the stress criteria and make + +sure that you have a zero margin of safety +with a factor of 1.4, is he told all the stress + +engineers, because they all worked for him, +design to a negative 10%. + +Which means if you really do your job right +this thing is not going to be able to reach + +ultimate load. + +It's going to break. + +But he also knew that they were probably conservative +because he was one of those guys. + +And he also had in his hip pocket, if he's +wrong he would find out because he had the + +opportunity to do an ultimate load test on +the airframe. + +It turns out he did the ultimate load test, +it passed the ultimate load capability and + +he saved a bunch of weight in airplane which +made it a very successful airplane. + +Sometimes from a systems perspective, it's +what you learn in the details or in the trenches + +as you're coming up and being able to apply +it the same way that Aaron did a lot of stuff + +as he was managing the program. + +On the airframe we looked at a lot of different +structural materials, we looked at a lot of + +different TPS materials, and some of the parameters +that were coming out in there was not only + +strength of the material but how much heat +sink there was because you were having to + +rely on that to keep the weights down. + +And let me go up one slide and show you something +here. + +I don't know if you can read that, but on +the left side what it was is it was all aluminum + +airframe. + +It had an ablator thermal protection system +on it. + +And you said, well, I thought you said it +was going to be fully reusable. + +Well, we also had a cost constraint. + +So we put that in there as a reference point. + +And that was the lowest cost. + +And here's weight up here. + +It wasn't quite the lowest weight, it was +pretty low, but it still was violating the + +objectives and requirements that we had. + +And we said that will be our reference point. + +Then we looked at different types of aluminum. + +We looked a beryllium. + +We looked at titanium. + +We looked at the thermal protection system +on a beryllium substrate. + +Every kind of combination you could think +of. + +The interesting thing was, look where the +whites were staying. + +They were all staying within the 60,000 to +80,000 pound total weight envelope. + +What was happening is we were decreasing the +thermal protection system thickness. + +If we were using titanium, which we could +operate to 600 degrees, the TPS weight was + +going down. + +Titanium was not as good a heat sink as aluminum, +even though we're working it to a higher temperature. + +And it turned out that the combination of +TPS plus structure was pretty much a constant. + +I'm oversimplifying it, but that's basically +what it was. + +And you can see where the cost was. + +This is beryllium titanium. + +The cost was way out of whack compared to +everything else, so we said we're not going + +to do that. + +And there were some other exotic materials +over here for hot structures. + +We said let's now decide what this airframe +material is going to be. + +It's going to either be aluminum or titanium. + +And total weight, total cost doesn't make +any difference, they're about the same. + +We weren't' smart enough to decide so we went +out to the skunk works. + +Kelly Johnson skunk works, I don't know if +you know what that means. + +Kelly Johnson designed and built more airplanes +in a short period of time. + +And they were the ones, Larry, was it in the +`50s, the SR-71 was designed, the Black Bird? + +I think it was in the 1950s. + +It was somewhere in there. + +They had to develop titanium for that airplane. + +It was a hot structure design. + +We went out and spent some time with Kelly +Johnson. + +We went through all this stuff with him. + +All right, Mr. + +Johnson, at the end of the day it's a mix +for us. + +Would you build it out of aluminum or titanium? + +He said aluminum. + +And the reason being is because titanium was +so difficult to work to produce. + +The manufacturing was difficult. + +Today it's a lot less difficult than it was +then. + +We made the decision and went with aluminum, +so we had to protect that structure to 350 + +degrees. + +That was a lot of work and a lot of analysis +to make that decision. + +And we talked to Aaron and said that's what +we want to do, and he said go for it. + +The next thing we looked at, we got the airframe +design, now we're starting to put together + +the fuselage. + +We said we can put this crew cabin as part +of an integral part of the fuselage or we + +can make it a separate pressure vessel inside. + +Went through the trades on this. + +And we came up with some of the discrete advantages. + +It's a purely simple pressure vessel when +you don't have any inertia loads, except the + +mass that is inside the crew module itself. + +There is a discrete attachment between the +crew module and the forward fuselage which + +means you could start the design and construction +of these two things in parallel. + +And simple interfaces are important. + +Somebody mentioned modularity, and it's probably +modularity in some analytical tools. + +But simple interfaces where you're putting +things together are extremely important. + +So, this created a very simple interface for +us. + +Also, we didn't have a lot of heat transfer +to the crew module. + +It was easy to control the environment within +the crew module. + +And we designed it out of a material, a 2219 +aluminum, which had an inherent advantage + +of if it gets a crack, the crack doesn't grow +catastrophically under the operating stress + +before it starts leaking a lot. + +Well, that's good because, from a crew safety +standpoint, you know that if the seals are + +working and it's still leaking you've got +a crack in that pressure vessel but it's not + +going to be a crack that is going to propagate +to be a catastrophic failure. + +We chose the floating design. + +When I talked a while ago about the crew of +seven in two weeks now compared to four for + +seven days, back in '72 we said we don't know +what the requirements are going to be, but + +let's make this thing as robust as we can +without penalizing ourselves weight-wise. + +So, we went back to Apollo and said what were +all the densities in the Command Module for + +the Crew Module? + +We figured out a density and a volume. + +We said that will be our baseline. + +That's what we came up with. + +Well, for another 50 pounds of weight, we +could increase the carrying capability of + +the crew module by about 500 pounds. + +That was a good trade at that time so we did +it. + +We just said we're going to design this thing. + +Instead of for 25,000 pounds we'll design +it for 30,000 pounds of payload carrying capability + +within the crew module. + +It turned out to be a good decision. + +We weren't smart enough to know operationally +we'll need larger crews for a longer period + +of time, but that helped us out a lot. + +You probably also want to mention, when you +look at the structure of the crew cabin, in + +both of the shuttle disasters, the Challenger +and Columbia, we have every indication that + +the crew cabin actually survived the breakup +of the Orbiter. + +So, it really was an excellent structure. + +I'm glad you brought that up. + +As a matter of fact, I have a note here to +bring it up myself. + +Jeff is exactly right that that's what it +did, but it was never designed to be a crew + +escape module. + +It had some inherent capabilities, probably +could survive some things that it couldn't + +had it been part of the fuselage, different +flight regime, so it had that inherent capability. + +But it was never designed -- And I know there +was a lot of talk after Challenger that it + +looked like it would have survived all the +way, but it would have never made it all the + +way. + +But it would have under a lot of conditions. + +We said Apollo didn't have a lot of thermal +stress issues, but we know this vehicle now + +we've skinnied down weight-wise as much as +we can to the extent that the thermal gradients + +between any two different pieces of structure, +where they were different materials or different + +masses is going to cause a thermal gradient. + +And thermal gradient cause thermal stresses. + +And you will see in a minute that was not +only important to stress but is important + +to all these tiles we were sticking on the +outside of this thing. + +So we said we have to look at every one of +these thermal gradients and we have to understand + +what that induced stress is because we had +an indication it was going to probably contribute + +about 30% of the total stress in the vehicle. + +It was going to be from thermal stressors +at different flight regimes. + +Kelly Johnson helped us out pretty well deciding +on aluminum and titanium. + +We said why don't we just fix this thing? + +We'll design around all the thermal stress. + +We'll put stress relief in it, like expansion +joints along the sidewalk. + +We'll do all these kinds of cute things and +we'll simplify the heck out of this. + +As a matter of fact, the SR-71, the Black +Bird, it had huge thermal stress problems. + +So the wing on an SR-71, normally the skin +carries a lot of the wing bending. + +Not true on an SR-71. + +It's corrugated skin so it can expand and +contract. + +All the wing bending is carried in the spar +caps, the frames that go out the entire wing, + +and the caps themselves. + +They paid a penalty but avoided the thermal +stress issue. + +We said we'll be smart with that. + +We'll go talk to the SR-71 guys. + +And we'll go talk to the Concorde. + +The Concorde was an airplane that had high +thermal stress, even though it wasn't that + +high a temperature. + +I think it was reaching 500 or 600 degrees +outside, but it was moving fuel around all + +over the vehicle. + +So when it moved this high mass of fuel from +one part of the vehicle to the other, it was + +creating big thermal stresses. + +They knew what to do. + +They designed in stress relief at these high +points. + +It bit them. + +Every time they did it they had fatigue failures. + +Every time they did that. + +They finally gave up and said just accommodate. + +We said we'll do that. + +Now then, we decided on that criteria. + +We're going to account for thermal stress, +but how can we do it? + +We don't have a 3D model that we can apply +mechanical loads to, I'll call aero loads + +mechanical loads, and temperature distribution. + +The finite element model didn't exist. + +We had a finite element model that had 50,000 +degrees of freedom, but we didn't have a computing + +capability to combine thermal and mechanical +loads on there at the same time to be able + +to decide how to size the structure. + +We said now we've got a problem. + +What the hell are we going to do about that? + +What we did is looked at what were the conditions +causing the thermal stress? + +Going uphill thermal stress is not an issue. + +It's all coming back in, in the entry phase. + +We knew we had initial conditions that were +going to primarily be the cause of it. + +Coming back where the vehicle had been sitting +in top sun for a long time, bottom sun for + +a long time, side sun for a long time, so +we looked at those initial conditions as being + +the worse. + +And we proved to ourselves that it was the +worst. + +Then what we cleverly did is we went around +the vehicle where we had a detailed structural + +model of a lot of stuff. + +And we created a hundred different thermal +models of different types of structure. + +This is one that was in the wing truss. + +We had a wing skin panel, we had a truss member +and a lower wing skin panel. + +And we did a detailed thermal analysis of +these hundred models. + +We then applied that to a structural model +simplified, which was giving us the internal + +loads and stresses that we needed, and then +we hand extrapolated that over the entire + +vehicle. + +There was no other way to do it. + +So, as you look at your analytical capability +probably on your damn laptop now, computing + +capability, you couldn't really do it on that, +but think about that. + +And I noticed nobody wants to talk about structures +as one of these groups. + +If one of you changes then I'm going to feel +really good when I go back and fight the hurricane + +in Texas. + +But that's the way we did that. + +It was a necessity that we had, but we didn't +have the capability so we invented a way to + +do it. + +And, I'll show you in a minute, it worked. + +Another issue that we had. + +Normally you'd like to just vent everything +through one area in the vehicle, but we couldn't + +do that because the payload bay had to be +very clean. + +It had to be contamination free. + +And there was hydrogen in the backend of the +vehicle. + +There was a pressure vessel in the front-end +and a bulkhead up there. + +We said what we've got to do is we have dictated +to ourselves that we have to design a venting + +system. + +This turned out to be a major part of a lot +of internal loads in the vehicle because of + +venting from one compartment to the other. + +And, stop and think about it, we had vents +all along the fuselage. + +We had a different pressure coefficient at +each one of these vents for our various attitudes + +during ascent, for our various attitudes during +entry, so we now had a whole myriad of complicated + +internal pressures that we had to accommodate. + +But that was pretty straightforward. + +We just complicated our design with the venting +system that we had, but we had to do it to + +meet the requirement. + +I don't know that people are actually aware +that there are all these vent doors because + +it's not something that you would normally +pay attention to in the pictures. + +That's right, you don't. + +As a matter of fact, in this book that Jeff +referenced, it shows where all the vent doors + +are. + +I didn't show that detail to you today. + +And they do open and close at different times +during ascent and entry. + +Venting just for carbon dioxide gases? + +No. + +When you start off you're at one atmosphere, +right? + +As you rapidly go uphill there's a delta p +across internal bulkheads and internal compartments, + +internal and outside the vehicle. + +And, depending on what the flight regime is +and where the shockwave is and where the vent + +door is, it's changing the whole venting thing. + +That's a whole lecture in itself on what we +did. + +The crew compartment is designed to have a +delta pressure of one atmosphere, but inside + +the payload bay, that's not designed to be +a pressurized environment. + +And so you need to be sure that the air can +get out of the payload bay fast enough that + +you don't over-pressurize, for instance, the +payload bay doors or other parts of the structure. + +There were some other trades that we had to +make. + +Let me skip forward so you can better understand +this. + +For reference purposes, the main engines are +here, 1.5 million pounds of thrust coming + +into this part of the vehicle. + +There is a Longeron that goes all the way +along here. + +A big mass up here with a crew module. + +And the crew module, I showed you, had just +discrete attachment points. + +All of the ascent inertia loads are reacted +right here, so all these loads go along this + +Longeron. + +Now, all of a sudden we have a very good and +efficient load path. + +The wing right here, this is a primary load +carrying member of the wing. + +That's a spar. + +And it ties into this big bulkhead which is +right here. + +When Jeff talks about the pressure differential, +don't forget this thing is 15 feet in diameter + +here so you can imagine the total loads you +have on that with a couple of psi delta p. + +It's big. + +That was a significant part of the driving +stresses in that. + +Another point I want to make about this is +-- Well, I talked about simple interfaces + +between the crew module and the forward fuselage +with bolted attachments. + +We had a simple interface between the wing +and the mid fuselage. + +A simple interface between the mid fuselage +and the aft fuselage. + +The same thing with the vertical stabilizer +and aft fuselage and these orbital maneuvering + +propulsion system. + +That was important, from a structural point +of view, to be able to modularize and analyze + +these things. + +But it was also important because four different +contractors built all these parts so they + +had to have an interface that they could not +only design and analyze to but that they could + +physically attach to. + +Sometimes, when you have just a sketch on +a piece of paper, you don't think about that. + +And it does cause a little bit of complexity +sometimes in a program. + +The main thrust structure is carrying 1.5 +million pounds of load from the engines. + +How do we design that? + +Well, we could have done a space frame or +we could have done a truss configuration. + +We decided to go with the space frame or the +truss rather than a plate girder, the term + +I didn't use correctly. + +And with that we saved 1700 pounds of weight +in the vehicle. + +We used titanium. + +And this is a compression design. + +We thought we needed to get a little bit more +weight out of this thing. + +What can we do to increase the compression +modulus of titanium? + +We put boron/epoxy, scabbed it on the axial +load members of the thrust structure, and + +that's the way we got a lot of that weight +out. + +That was a manufacturing problem, I won't +go into now, of how you build this thrust + +structure, but it works fine. + +The aft wing carried through -- Excuse me. + +Go ahead. + +I just had a quick question. + +Sure. + +We heard earlier that there was a CG problem +in that the CG was too far forward in the + +aft [but bled in the back?] for a number a +number of missions. + +I was wondering how that weight that they +had to add to the CG compared to the weight + +that you guys saved. + +The weight of the payloads themselves, you're +saying that there was a problem if heavy weights + +were too far aft or too far forward? + +The Orbiter. + +I guess the CG location was too far forward +and they had to adjust it on certain missions + +by adding weight near the back. + +Well, what that is, that is true and that's +a problem. + +It's not a problem. + +It's something that has to be addressed on +every mission, depending on what the payload + +is that you're carrying. + +If you have a real heavy forward payload, +yeah, you have to add some ballast to the + +aft end of the thing. + +Now, normally the way they do it is they'll +find some payload that can fit in the aft + +end to help ballast that. + +But I think, in some of the early flights, +we put some ballast in the back for CG control. + +We've carried many tons of lead into orbit, +so it was ballasting the thing for control + +purposes. + +The same way yesterday in Jet Blue, a lot +of people had to move to the back end of the + +airplane because they wanted that CG for a +little bit different landing performance. + +1307 bulkhead, we saved about 500 pounds there. + +Now, see what we're doing? + +We started out with the initial trades in +the early concept phases. + +What's the wing loading? + +We didn't care about what the internal structure +trades were. + +Now we're getting down to trading all the +stuff at a semi-macro level. + +And I'll show you in a minute a micro-level +that we had to get into, which was pretty + +interesting. + +How are we doing time-wise? + +We're OK. + +So, we saved some weight there. + +An interesting thing about the payload bay +doors. + +We decided that for this vehicle to be safe +and to re-enter those doors had to close. + +We had a lot of trouble in Gemini with things +on orbit not working. + +Mechanical systems quite often are problems. + +Docking systems are problems. + +There have been a lot of door problems on +orbit in spacecraft. + +And you design them and you put them in thermal +vacuum chambers and they all work, but you + +get on orbit and sometimes they don't work. + +Maybe it's thermal distortion that we're not +accounting for. + +So, we said that is critical. + +We've got to close these payload bay doors. + +What we did was say the way we're going to +do that is the payload doors will carry only + +two types of load. + +They will carry pressure loads, like Jeff +talked about, and they'll carry torsion loads. + +Because, if they are closed, we know that +it is good for torsion in the vehicle, reacting + +torsional loads. + +But we will not let them carry body bending +loads or else we cannot make them flexible + +enough. + +What we did is all of the body bending in +this vehicle is carried along this Longeron + +through this section in the lower skin of +the vehicle. + +This is the modulus of the vehicle, if you +will, at a cross-section here between this + +Longeron and the lower skin. + +Payload bay doors don't come into being. + +And the way the doors close on orbit is they +start zipping along from here up to the top + +because they are flexible. + +And the same way back here, they zip closed, +zipping just a latch at a time. + +They were sort of ratcheting themselves closed. + +And then they close along the center line. + +There has never been a problem with payload +bay door closures on orbit. + +It was something we decided to add to the +design. + +We could have made the vehicle lighter had +we not done that, but we would have also complicated + +the safety of the vehicle if we had done it. + +Sort of in line, but it's not the CG thing, +we had a payload attachment issue. + +And, when we were laying out all this stuff +in the early `70s, we didn't know what the + +payloads were. + +We knew what the total mass was. + +We knew there may be five at a time. + +We didn't know what they were. + +Now, you can just go in and bolt a payload +into the fuselage of the Orbiter. + +And if you just do that randomly or without +thinking about it, now all of a sudden you + +start analyzing the Orbiter and you start +twisting it, what happens? + +The payload becomes part of the load path. + +Now, all of a sudden, you have impacted the +design of the payload or maybe you have impacted + +the design of the Orbiter depending on what +is happening in the payload. + +We said ah-ha, what we'll do is make it so +it's statically determinant. + +If two things are attached statically determinately +they cannot interact with one another as far + +as their stiffnesses are concerned. + +We said that's what we're going to do. + +We'll put attachments along the Longerons +to carry the axial loads, some along the keel + +to carry some of the lateral loads. + +Viola, we've got it. + +So, the requirement became that we would design +it that way. + +Our next step was, and you can ask Al Louviere +when he comes up about that because Al Louviere + +and Max Faget told me they would never fly +with those Longerons that way. + +We did it anyway. + +What we had to do then was say now we understand +what the attachment is. + +How do we determine within the CG constraints +for these different masses -- And we had to + +assume what they were not knowing exactly +the definition of the payloads. + +We did a Monte Carlo analysis. + +Ten million cases of combined payloads. + +CG locations, numbers of payloads, forward, +aft, all that. + +And we did that with a Monte Carlo analysis. + +We said voila, that's where we're going to +design the mid fuselage. + +That's the way we did it. + +Now getting into the detail design loads. + +How do we determine all these things now? + +Because now it's coming down to sizing the +vehicle. + +This part of the flight regime from liftoff +through max Q, that's a critical loading condition, + +a critical design for the Orbiter. + +When it gets into orbit pretty benign. + +Nothing is really happening up there except +some temperatures which are going to be important + +at this point over here, because now all of +a sudden you start adding more heat into it. + +Now you get into the regime where you're maneuvering +in the atmosphere. + +Now you're in a different loading regime which +becomes critical. + +So, critical as far as the airframe is concerned, +is here and over here only. + +Let me break that down into the constituent +portions there. + +Liftoff loads. + +We had another statistical challenge here +because what we had to do was needed to look + +at all the variables associated with the rocket +engines. + +They have start sequences. + +We've got three main engines that are not +going to start exactly the same time. + +They're not going to come up with the same +thrust profile as they start up. + +The thrust vector misalignment is going to +be different. + +And we also had to look at ignition over pressure. + +And I'll show you that was a surprise to us. + +Also part of liftoff we had to look at winds +and gusts, vortex shedding, proximity of aerodynamics + +to the other structures is on the gantry in +the pad. + +And then we had to do the pressurization and +also look at shrinkage of these vehicles that + +components or elements at cryo-temperatures. + +Here was a cross-section, in a generic sense, +of what's happening during liftoff. + +There is some combination of winds that you +have to account for. + +And I will show you what we did there. + +The thrust profile from the SSMEs. + +The SRBs come up to thrust after you get confirmation +that the engines are operating at full performance. + +And there is a lot of vibration acceleration +going on. + +Here is something that becomes pretty obvious +after a while. + +When you have a vehicle that is tied down +here with a base moment and you put 1.5 million + +pounds of thrust on it, this vehicle is going +to bend over this way. + +There is a lot of strained energy in the solid +rocket motors when that happens. + +If you were to ignite the SRBs, when that +vehicle is over here, the party is over because + +it releases all that strained energy and the +SRBs couldn't take it. + +When you see the Orbiter prior to liftoff, +the SSMEs will come up, you will see the vehicle + +do like this. + +And then, when it comes back over zero, viola, +you kick off the SRBs. + +But you have to wait until it gets back to +that neutral point. + +A little detail that is pretty important. + +Ascent. + +A really complicated part of the design of +the vehicle, especially with the aerodynamic + +surfaces. + +As I said before, you would like for these +things not to be there during ascent. + +They don't buy you anything. + +You just need them coming back. + +Some other complications here are the acoustic +effects will become important, as I'll show + +you, in acoustic fatigue for the vehicle. + +I showed you life. + +Well, that's going to be a critical thing. + +Another thing is the plumes of the vehicle +are changing the pressure distribution as + +you're going up. + +The pressure distribution along the Orbiter, +especially the wing, is changing the whole + +times you're accelerating, not only through +the various mach regimes but also because + +of the blockage from the plume expansion. + +We said how in the world are going to do that? + +We cannot analyze all those things. + +If we do it deterministically, you won't get +a capability that you need, we thought, operational. + +We said what we'll do is one piece of data +that we had, we had synthetic wind profiles + +for everything that existed at the Cape. + +We said that's a given. + +We'll use these synthetic wind profiles as +a guideline to all of our winds aloft. + +What we need to do is decide what the angle +of attack and the side slip is going to be + +through this vehicle flying through these +winds and a control system that's changing + +the attitude of the vehicle. + +That's a factor that we have to consider and +that's going to be important for the design + +of the elevon surfaces and all because they're +getting loaded up pretty heavily at that time. + +There are dispersions in the propulsion system +that have to be added. + +And then what we decided to do, after we looked +at all that, we said what we're going to do + +is we're going to take all these parameters, +and you won't find this in any textbook, but + +we created something called a squatcheloid. + +And I forgot to look up what squatcheloid +means. + +It must be a Greek term that was really good. + +But what we did was flew the vehicle through +different mach numbers. + +And we looked at the various conditions we +could get at for combinations of dynamic pressure + +and angle of attack and dynamic pressure and +side slip for all the mach numbers, and then + +we said is that realistic to do, not only +from a control systems standpoint but from + +a standpoint of the propulsion system capability? + +And we said it is feasible to do so we ought +to design within those envelopes. + +What we did was walked our way around all +of these external points with pressure and + +inertial loads and everything else and we +looked at the structural model that we had + +simplified. + +And we said we found the points that were +critical for the vertical stabilizer, for + +the outboard elevon, et cetera, and that's +the way we designed the vehicle for ascent + +loads. + +The thing that that enabled us to do, too, +is it enabled us to do a rational combination + +that Aaron brought up a while ago. + +What did you do with the SSMEs for engine +out and that kind of stuff? + +It let us do a rational combination of engine +out and also engine vector control. + +You could design the thrust structure so that +the engines went out to the extremes, but + +it didn't make sense as far as the control +system was concerned. + +What we did is we saved a lot of weight in +the vehicle by using a deterministic or realistic, + +I should say, SSME thrust profile and vector +characteristics. + +Well, I just mention that. + +That's what the squatcheloid did for it. + +Also what it did was then gave the guys who +were designing ascent trajectories, now they + +had an envelope to design to, which was key +for their operations. + +Next problem. + +Now we come back to descent loads. + +When you said that you designed it for realistic +cases instead of worst cases, does that mean + +the engines were never able to vector all +the way out to maximum? + +Right. + +It just could not happen? + +It could not happen. + +That was a failure mode that it had enough +redundancy and it couldn't happen, and there + +wasn't any need of creating a load condition +like that. + +It couldn't happen. + +OK, so you looked for it. + +We looked for the cases where you could be +in the worst case winds, the worst case misalignment + +with the SRB, with the different throttling +of the engines. + +And we did all that and said to control this +vehicle, because if you cannot control the + +vehicle there's no need to look at that load +case. + +We said to control it within those environments, +what's the extreme of the engines? + +We said that's a design case for the thrust +structure. + +Good question. + +Descent loads. + +This was pretty easy. + +The structure guys said this is a piece of +cake because this vehicle is coming back in, + +in a ballistic trajectory. + +And, viola, there are not even loads on this +vehicle. + +Well, that didn't make a whole lot of sense +because we knew that there would have to be + +more maneuvering capability than anybody was +fessing up to. + +Not that they weren't trying to hide it, but +we weren't smart enough. + +The Aaron Cohen guys weren't smart enough +to know all the conditions we would have to + +fly it to. + +What we did was we went through the classical +Venn diagram where you're plotting for different + +mach numbers. + +The normal load factor versus the velocity +of the vehicle that it can fly in that flight + +regime. + +We said if this thing is going to behave like +an airplane and have to perform like an airplane, + +we are going to design it like an airplane. + +We caught a lot of guff. + +When Bass Redd comes in and talks in the future +ask him about this because he fought us on + +this hand and foot. + +He said you guys don't have to design it that +way. + +We said well, we're going to, but let him +have capability in his aerodynamics and talk + +to the control system guys about that, too. + +And I see the Draper guys left on that. + +[LAUGHTER] We said we're going to build in +that capability for this thing to maneuver + +like an airplane. + +2.5 g's normal load factor. + +Follow-up classical Venn diagram where we +have equivalent airspeed of 375 psf. + +We were determining what the equivalent air +speed for those conditions was. + +And then we did it. + +Now we've gotten up to a point I'll call CDR, +and a point I should have mentioned a while + +ago. + +When I showed the authority to proceed, there +aren't any drawings which exist, except some + +sketches. + +I mean there are mol line drawings and that's +about it. + +And the mol line of the vehicle was what came +out of all the other studies. + +It said that's it, we've got to put everything +within this mol line for this vehicle to perform + +like it is. + +But there are no detailed drawings. + +When you get to a preliminary design review +in a classical design and development program, + +typically that's about where you reach 10% +of your drawings that are released. + +And what does it mean to release a drawing? + +That means you sign it off, whatever your +discipline is, and it say we can make this + +airplane to these drawings and it's given +to the people to go make it. + +So, once you release a drawing you don't ever +want to bring it back and change it because + +it costs you a lot of money. + +The PDR, which was somewhere like about '73, +'74, somewhere like that, that was the state + +which we existed. + +We hadn't defined everything on the structural +low pass like I told you about a while ago, + +nor the materials. + +Now we're at the detail design. + +Now we're into CDR, that's the critical design +review, and 90% of all your drawings are released. + +And now it gets very expensive to go back +and change. + +You can just see how it would ripple through +the entire operation if you change a drawing + +at that time. + +You have to, to make it work sometimes, but +you like not to change it. + +What we have to do here, our challenge from +a structural point of view is to complete + +the design, do some of the details which means +get weight out of the vehicle where you can + +scrape it without really changing a lot of +stuff. + +And then also decide how you're going to certify +the vehicle. + +It means what you're going to do on the ground +to say it's really safe for the crew to get + +in. + +That's what that was. + +Weight reduction is a major part of the program. + +Here are some of the things that we took out +about this timeframe. + +We took out 900 pounds of weight in the payload +bay doors. + +We didn't change the configuration, they were +still flexible, but they were aluminum honeycomb. + +We said we can save 900 pounds if we go to +graphite/epoxy. + +Graphite/epoxy characterization of the material +didn't even exist then. + +Literally Aaron, myself and three or four +other guys sat around. + +We said OK, Aaron, this is what we have, this +is what we know about it, here are the risks + +associated and here is the weight savings. + +Go for it. + +So, we went for it and it worked. + +That was the largest graphite/epoxy structure +ever flown. + +We characterized it, passed that on to the +industry and that helped a bunch. + +Another little interesting thing -- I have +to watch my time here. + +I mentioned the spending profile. + +Well, we got into the program about the time +we were starting to make the payload bay doors, + +which is probably '75, '76. + +And Aaron didn't get all the money that he +needed. + +We built the first set of payload bay doors, +which is people process dependant. + +It's like laying up fiberglass. + +It was all hand layup with epoxy and bake +it and all that kind of stuff. + +We got the first set built and we fired everybody +because we didn't have enough money to keep + +them on the payroll for the rest of that year. + +We literally laid everybody off at Rockwell +in Tulsa. + +And they came back a year later, not all of +them, but we had to start over again. + +So, there is a risk associated with that. + +Thrust structure. + +We saved 1200 pounds by stiffening, like I +told you about a while ago. + +And then we used a bunch of other composites. + +A lot of people said, especially after Challenger, +let's get rid of this vehicle because it's + +antiquated and was designed too long ago. + +That probably is still one of the most advanced +composite structure vehicles flying today. + +Except, where there is a lot of aluminum honeycomb, +you probably could go with graphite/epoxy. + +And I will give you a challenge with that +later on. + +But there are beryllium aluminum struts in +here. + +There are boron/epoxy scab on devices. + +There is graphite/epoxy all over the vehicle. + +Not all over the vehicle. + +In a lot of places in the vehicle. + +The vehicle has got a lot of composites. + +And we stretched to be able to do that. + +Certification. + +Now we've got the thing pretty well designed. + +What are we going to do to certify this thing? + +This is where we deviated from the norm and +were pretty innovative. + +Classically, in the way this program started +off, there was a dedicated structural test + +article and there was a dedicated fatigue +test article. + +There were a couple of problems with that. + +If you don't need it, you might as well not +build it, even though that was in the program. + +The situation was, as I showed you a while +ago, thermal stress was a major part of that. + +You couldn't apply a mechanical and thermal +load to this vehicle and still be practical. + +Concorde did it. + +The way that Concorde was designed and certified, +they applied mechanical loads in an environment + +in which they could induce the temperature +by convective heating on that vehicle. + +And it took them like three years to test +the vehicle. + +And it was extremely expensive. + +It was a big jobs program for Greg Britton +and France and some of the others, but we + +decided we couldn't afford to do that so we +are going to have to figure out how else to + +do it. + +Besides that, Aaron had $100 million problem +that year. + +What can you guy help us do? + +What we'll do, we think we can do this, is +take an airframe and we will apply 110% of + +the limit mechanical loads only to it. + +And that doesn't certify anything. + +And then we will put strain gauges all over +this vehicle. + +And we will pre-predict what the strain response +is going to be for 3,000 points on the vehicle. + +If we can pre-predict what the strain response +is for applying a bunch of different loads + +then we know how to analyze the vehicle. + +That proves we know how to analyze it. + +We can extrapolate to 140% to our ultimate +load capability from mechanical, and we will + +add the thermal stress to it analytically. + +So, we did that. + +And then we refurbished the vehicle and that +became Challenger. + +The test article is going to cost $100 million. + +We said we don't need it. + +We'll use it for a flight airframe. + +And Aaron gave us a little ceramic eagle for +doing it. + +Don't anybody expect As out of this deal, +if Aaron has anything to do with it. + +There it was. + +We applied the million and a half pounds of +load at the backend. + +We concentrated through loading fixtures, +loads on the wings of the fuselage, put pressure + +differential at various points on the vehicle, +and we did exactly what I said. + +Fatigue life. + +Mechanical fatigue was not a problem. + +Acoustic fatigue was an issue because we had +some really lightweight structures and really + +high acoustic levels. + +You cannot see it here. + +It was like 165 DB around the base-end of +the thing, lower levels on other portions, + +so we said how are we going to do that? + +We came up with a different way to do it. + +What we will do is we'll go around the vehicle +and we will identify a characteristic structure, + +graphite/epoxy, aluminum, 7075-T6 aluminum +fuselage up here, wing elevon, aluminum honeycomb, + +et cetera. + +We identified 44 test articles. + +We said that's what we'll do. + +We went to Aaron and said it's going to take +us 44 test articles. + +We went through all the rationale with each +one of them, and he said you can have 14. + +And so we said but that won't work. + +He said go figure it out. + +We went back and scratched out heads. + +Sure enough, we figured out how to do more +extrapolation. + +So, we had 14 test articles that you see. + +And then what we did was say now we've got +our test articles. + +Our approach to this thing was we would test +them to failure acoustically. + +Now we have an acoustic allowable for that +type of structure because it's a function + +of the details. + +I mean it had to be the detail. + +And, in addition to making sure we have a +good test, if this was our acoustic fatigue + +test article, only the center third was a +viable part of the test because the rest of + +it is boundary conditions that weren't right +because they were clamped along the edges + +or whatever. + +We said only the middle third of the test +article is viable. + +We tested that, we got a fatigue allowable +from acoustics and then we degraded it analytically + +for combined mechanical and combined thermal. + +We did that and said also we know that it's +probably not going to fail on the first flight + +so we'll do some inspections. + +Tom, let me just make a comment. + +He made it sound a lot simpler than it was. + +One thing that's important, whenever you do +a project or you're in charge of something, + +you don't want to have yes people around you. + +You want to have people that say you're not +doing it right. + +And it didn't go down that simple. + +They were not yes people, believe me. + +They were certainly not yes, sir, we're going +to go do this. + +That's very important. + +It's a wonder we still speak to one another. + +[LAUGHTER] I'm sorry. + +I don't know what a test article is. + +It's a test specimen. + +If you wanted to put so much mass in here +and you weren't sure whether this seam was + +going to work. + +You just put that much mass in here. + +You add a little bit more to it and you see +if that seam breaks. + +That's your test article. + +That's what it is, just a test specimen, test +article. + +But that's a good point because, don't forget, +we start off with two entire $100 million + +test articles for static test and for fatigue +test. + +Not counting acoustic fatigue. + +That was just mechanical fatigue. + +As we got into it we said we don't need that. + +Did the Challenger's mission life drop because +of the test? + +No. + +As a matter of fact, that's a very good question. + +That was one of the questions that was asked +by the investigation is what's different about + +this vehicle than any other vehicles? + +Well, it was a static test article. + +And we showed ad nauseam that had nothing +to do with the failure of Challenger. + +The leading edge was not -- Oh, no, excuse +me. + +I'm off on Columbia now. + +No, it didn't have anything to do with it. + +As a matter of fact, this is getting into +detailed details now, when you apply above + +a limit load on a vehicle like we did on Challenger +it puts a lot of the joints in residual compression. + +There is compression at the joint just as +you load it and you unload it. + +And residual compression increases the fatigue +life of the vehicle. + +And the reason it does is because fatigue +is the function of tensile cycles, not compressive + +cycles normally. + +When McDonnell Douglas tested a DC-10 and +they proof load a vehicle, it carries a premium + +on the selling price for that because it theoretically +has a longer life than one that hasn't been + +loaded. + +Good question. + +Tom, one more question. + +Yeah. + +How much did an increase in computer processing +speed and availability allow you to do these + +extrapolations and like do the thermal testing +just analytically? + +Was that a key factor? + +You mean how much as it increased? + +Well, how much did it increase between like, +say, Apollo and designing the Shuttle. + +Not a whole lot. + +As far as the analytical capabilities of the +finite element models and all, you could get + +more detail through simplification. + +There are more elements available, let me +put it that way. + +But as far as the crunching capability, it +increased somewhat but we were still, you + +know, if you have to go from here to here, +we were about here. + +That isn't a quantitative answer for you, +but we're still a long way. + +We basically used mainframes, and we did have +the NASTRAN model. + +Yeah, we had NASTRAN. + +But NASTRAN didn't have, on a large model +like that, the large capability for structural + +loads and thermal loads. + +But you used to put your cards in one day +and it would take a couple days before you + +got your answer. + +To do a complete load cycle on this vehicle +for internal loads it was something like three + +months it would take us to do that. + +And so it was quite [OVERLAPPING VOICES]. + +That's another story. + +Thermal protection system. + +Change gears now. + +Let's talk about the thing that protects the +vehicle. + +Now I'm going to switch back and go back to +get ready to proceed toward preliminary design. + +What were the requirements on the thermal +protection system? + +It had to protect the vehicle from max temperatures +like about 2800 degrees on the surface, reusable + +100 times, it had to be lightweight and had +to be cost-effective. + +Pretty simple high-level requirements. + +And Dr. + +Bob Ried will talk to you about the things +that they derived as far as the aerothermal + +in this and how it became that, but it was +a given to us. + +What did we know about this thing? + +Well, we had some ablative TPS experience +from Apollo. + +Gemini had some metallic TPS on it primarily +Rene 41 and some other exotic materials. + +Mercury had an ablative TPS, but they weren't +reusable. + +They were hot structure designs which existed +but that we didn't have materials that could + +carry the load at temperature such that it +could be a fully hot structural design, and + +that was extremely complex. + +Metallic TPS, we could get there theoretically +with some fairly exotic materials called columbium + +and Rene 41 and some other things, but the +devil is in the detail in that. + +Let me tell you a story about that. + +We were looking at some Haynes 188 panels. + +And so we had a test article, a big panel +about the size of the desk that you're sitting + +at, any one of you there, and it was corrugated +so that it could expand and contract. + +And it was good for 1800 degrees, so we tested +it to 1800 degrees in the center of the panel + +multiple times. + +And it had a frame around it where the panel +could move around because it needed to, to + +be able to thermally expand. + +And the center of the panel was 1800 degrees, +the edge of the panel where the heat sink + +was, was 40 degrees lower temperature than +the center. + +And the panel floated within a gap maybe about +like that, so it could move around pretty + +good. + +But what it also did, with that temperature +differential of 40 degrees, we got something + +called creep buckling. + +The structure expanded and crept and deformed +permanently. + +Had we flown that vehicle, had we designed +a vehicle like that, what that would have + +done is would have allowed plasma to flow +through the shingles, if you will, and into + +the structure. + +And that's exactly what happened in Columbia. + +Letting the hot plasma gas get in the vehicle, +you cannot stand it. + +It's the details about that. + +We said we're not going to go with a metallic +design. + +Plus, if you scratch it, it oxidizes. + +And, if it oxidizes, then it can fail. + +So we went with something that was just coming +online, and that was a fused silica material. + +And fused silica is pure sand, pure silica +material. + +That's all in the world it is. + +The process is you make it into a fibrous +structure, if you will. + +Fibrous material is a better term. + +A fibrous material that is mostly air. + +It is about the same density as balsa wood. + +It has an ultimate strength of about 12 psi, +tensile load is about all that it can take, + +but it has a thermal performance that is fantastic. + +As you will recall this chart here, when you +look at LI-1500, is what that was with aluminum, + +and that's what we went with, we used this +same characterization to decide what the material + +we were going to use was on the vehicle from +a weight standpoint and a cost standpoint. + +The way the tiles work thermally like this +is the low strength brittle, almost like glassy + +material, it's a ceramic, is coated with literally +a glass coating on the outside about 60-thousandths + +of an inch thick and it's black. + +As the vehicle comes back in and dissipates +its energy through drag and heating, 90% of + +the heat is radiated away from the vehicle, +10% of it goes into the vehicle. + +But this is such a good thermal isolator, +a poor thermal conductor, by the time the + +heat gets to the vehicle, the vehicle is back +into an atmosphere where it's not heating + +anymore. + +That dictated the thickness of these tiles, +of this silica material. + +The vehicle has got almost 21,000 tiles on +it, and they vary anywhere from a half inch + +thick up to about three inches thick. + +It's sculptured to stay within the mol line +because the aerodynamicist told us what it + +has to be. + +And so what we did was sculptured the TPS +so that we didn't have any more than we needed. + +Great job by all the thermal analysts. + +I mean they did this fantastic. + +I want to mention, when that says 9 pound +or 22 pound tiles, that's not the weight of + +each individual tile, that's the density per +cubic foot. + +Per cubic foot, correct. + +Thank you, Jeff. + +What was the footnote about Columbia on that? + +On the last chart, Tom, there is a footnote +about the difference in the Columbia. + +Let me come back to that in just one second. + +What I want to talk to you about right now, +this is something I had from some old material. + +I was just trying to get a characterization. + +What that said is on Columbia there was an +infrared sensor as an experiment. + +So, the number of tiles varied on that vehicle +compared to all the other vehicles because + +of this infrared thing at the top of the vertical +stabilizer. + +I should have cut that off. + +You're reading too close. + +[LAUGHTER] We thought let's figure out how +to take this fragile material and put it on + +this aluminum structure which has a high thermal +coefficient of expansion. + +The tiles have almost a zero thermal coefficient +expansion. + +We said we've got to isolate that. + +We put a strain isolation pad [UNINTELLIGIBLE +PHRASE]. + +Why do they vary in density? + +Yeah. + +Because primarily for strength, for one of +the things. + +And the LI-2200 was a little bit higher temperature +capability. + +And I don't remember [OVERLAPPING VOICES]. + +But it had a little higher peak temperature +capability. + +And that was dictated by what one of the failure +modes of a tile was if you exceed the temperature + +too much it starts slumping. + +I don't want to say melting but it begins +to distort. + +And a LI-2200 didn't distort to the same extent +that a LI-900 tile did. + +We said let's isolate the structure here from +this material up here which is required to + +keep from failing all these tiles, so we put +something between them. + +It was just a very loosely woven felt material. + +Now we proved that the aluminum can expand +all it wants to, or within limits, we looked + +at it realistically, and that the tile was +OK, except the tile couldn't be too large + +because of this relative expansion and contraction. + +So, that dictated the size of the tile. + +We literally pre-cracked them, if you will. + +We put expansion joints is another way of +looking at it. + +A typical tile is 6 inches by 6 inches when +it gets into the highly heated area. + +Now all of a sudden we've got some room for +the title to move relative to one another, + +structure to move underneath it because of +the strain isolation pad. + +And we said, viola, we've got this problem +fixed. + +We're good to go.. + +We said we've got 25,000 of these tiles that +we now have to certify that they're good to + +go for the vehicle. + +There were gaps between the tiles? + +Correct. + +But, when you re-enter, do the tiles expand +so that there are no gaps? + +No. + +What we do is make sure that the gap can just +close but not close such that you're loading + +one tile relative to the other. + +That set the gap. + +And, if during manufacturing which is not +that precise, if the gap was too large we + +just stuck a gap filler in. + +Not the one that was on the last vehicle. + +It's a different kind of gap fill. + +Just a piece of Nomex or SIP material strain +isolation pad coated with rubber or with RTV, + +and we stuck it in between the tile just to +reduce the flow if the gap was too large. + +So there is no chance that you would have +hot plasma coming in between them? + +Yes, there is a chance you can have plasma +going through there if the gap is too large. + +We had a very specific requirement. + +I think it was like 90-thousandths of an inch +between tiles. + +And if it were, say, 130-thousandths of an +inch, as installed because of tolerance buildup + +and all that kind of stuff, then what we did +was stuck a plasma flow preclude, if you will, + +a gap filler between those to stop the plasma +flow from getting between the tiles. + +And we had some experience where we lost some +gap fillers, plasma flowed between the tiles, + +caused excessive heating on the tiles and +started causing them to slump and melt a little + +bit, did a little bit of structural deformation +but nothing significant. + +Losing gap filler was a turnaround issue, +not a safety of flight issue. + +We made sure of that. + +Excellent question. + +This is more of a general question, but I'm +wondering if since then anybody has done any + +work to find a material that could accomplish +both tasks, the structure and the thermal + +protection rather than having to deal with +these types of issues. + +That was back to one of my trades were we +said let's take that approach and see if we + +cannot design a vehicle that can take the +temperature and the loads, too, both. + +There was no material that existed. + +I don't think a material exists today that +I know of to be worked to a high enough stress + +that you can keep the weight down to have +those kinds of temperatures and to be worked + +at a high temperature. + +I think on the X-33 design they were talking +once again of trying to make it out of a metallic + +structure. + +Part of it was structure and part of it was +tons. + +But we never got to the point of being able +to fly and test it. + +But they also were using a thermal isolation +system like tiles over part of the vehicle + +on the X-33. + +The Buran, which was the Soviet copy of the +Shuttle, they were very anxious to get away + +from the expense of the tiles. + +And they ended up with a thermal protection +system not very different than what you said. + +You mean they had tiles? + +Yeah. + +As a matter of fact, I remember they were +more like bigger blankets. + +That's a good point, Larry. + +I was about to skip over it. + +I said they were typically 6 inches where +they were really thick, but in other areas + +we made like 12 or 15 inch tiles that were +very thin. + +And the reason we could do that is we decided +if they crack it doesn't matter because the + +gap wouldn't be large enough for the plasma +flow to go through there and it would simply + +be a self-relieving. + +So, we tried to reduce the cost of manufacturing +by making some of these tiles larger. + +And I will show you that in just a second. + +I'm going to skip forward here and show you +one thing.. + +That's 50-thousandths of an inch. + +The allowable for the tile was 12 psi. + +The ultimate stress was 12 psi. + +The allowable stress was about 8 psi. + +And that's with the total loads combined on +the tile. + +What do you have to consider in one of these +25,000 tiles that you have to assure is not + +going to come off the vehicle? + +Remember I said when we looked in the early +phase studies of the vehicle we were looking + +at wing loads and stuff like that? + +Then we got into how is the wing going to +carry the load into the fuselage to the spar + +and what was our design trade on that? + +Those were sort of macro and semi-macro systems +engineering studies. + +Now we're into a micro. + +Now we've got this little critical part, 6 +inches by 6 inches. + +Lose any one of about 10,000 and you lose +the vehicle. + +It's got an 8 psi allowable strength. + +We said well, that's no big deal. + +What are all the environments on this thing? + +We started looking at pre-liftoff, liftoff, +ascent, et cetera. + +There is always something called mismatch. + +When you take something that is not perfectly +smooth and you bond something to it and they + +are not to the same flatness, if you will, +there is going to be a stress induced into + +both parts of those. + +Well, the structure doesn't care about that +stress but this little 8 psi allowable tile + +does. + +It says we cannot exceed about 19-thousandths +of an inch under one of these tiles for this + +to happen. + +There is ignition over pressure during ascent. + +There is acoustic and vibration and that kind +of stuff that has to be considered. + +On ascent there are gradients because of shock +moving across the tile. + +There is internal pressure. + +There is skin friction and drag on the tile, +so you've got to consider that. + +You have to consider the dynamics, the inertial +loads induced in it. + +And the out of plane deflection is now the +vehicle flying. + +The structure is deforming. + +So, you've got to consider that. + +Now you can see you've got 25,000 tiles with +all these combinations of load conditions + +so how in the hell do you design that? + +This is the characterization of it. + +This is what happens with a structural deformation +of like 10-thousandths of an inch deflection + +underneath a tile. + +With that kind of formation it causes 1 psi. + +And it linear almost. + +So, 20-thousandths of an inch deflection is +going to cause 2 psi. + +Well, 2 psi is not a lot but it's a quarter +of your allowable. + +We said we've got to consider that. + +We have to understand what is happening to +this structure as you fly it, a condition. + +This is a free body, if you will, of the pressure +distribution on a tile. + +It has internal pressure within the tile. + +It has a pressure differential on the outside +of the tile because of a shockwave moving + +across it because of the pressure as it varies +around the vehicle. + +So, you have to consider all of that. + +We did all that and said we've got a problem, +because what happened was all of a sudden + +our allowable on our tile was decreased by +half. + +And this was not good. + +We screwed up, in the systems engineering +point of view, when we did this. + +Remember we put the strain isolation pad underneath +the tile and we did all these other loads + +on it? + +What we forgot, or what we didn't realize +was this strain isolation pad had little stiff + +spots in it because of the way it was stitched +to keep the strain isolation pad together. + +And every stiff spot acted like a hard point. + +Now, when you take a tile and you put external +loads on it and there is a stress concentration + +on each one of those things, that stress concentration +had an amplification of two. + +All of a sudden our allowable were decreased +by a factor of two. + +And we thought we have a major problem. + +This is when Aaron and I got to know one another +better than we ever wanted to. + +We met every day on this thing. + +We had tiles bonded all over the vehicle. + +Necessity was the mother of invention. + +What we had to do was dissipate this stress +concentration. + +We said we'll put a plate underneath it, a +graphite/epoxy plate or something like that. + +That would have added a lot of weight to the +vehicle. + +Glen Ecord, a materials guy came up with the +idea in the lab one weekend, he took silica + +powder in water and just painted it on the +bottom of the tile. + +What it did was fill all the pours in the +tile for about three-sixteenths of an inch. + +And just compacted themselves in there. + +And that was an inherent capability of a tile +with that powder packed in it, if you will, + +that doubled the strength of the tile. + +What it did is it dissipated the load from +being concentrated into the tile. + +So, without any weight, some cost, we had +to pull some tiles off the vehicle and densify + +them. + +Now all tiles are densified. + +I meant to bring one to show you today but +I didn't. + +Analytically, we went through 25,000 tiles. + +Here was our factor of safety distribution +over the entire vehicle. + +We said we're good for that, but the thing +we don't know is if the tile is really bonded + +on the vehicle like it should be. + +We said we can fix that problem. + +We will verify it. + +We will pull on every tile and make sure that +it has a capability of the maximum expected + +mechanical load that it is going to see. + +And so we pulled on every tile. + +And John Yardley, being an old stress guy, +says let me ask you a question. + +When you pull on every tile, how do you know +you haven't induced more damage and decreased + +the allowable of the title because of your +proof test? + +Good question. + +Easy answer. + +We'll put a microphone on every tile and we +will characterize the sound of the tile as + +we pull up on it, and we will get a sound +allowable, if you will, for proof-testing + +the tile. + +We did that on every tile that had to be proof-tested. + +We had an acoustic emission device, we had +a microphone on there, we characterized all + +these tiles and we did it. + +Another little mother's necessity of invention. + +And I'm not going to go through this. + +You'll get a handout of this. + +What this did is said you cannot proof load +every tile, every tile is not densified, some + +tiles are thick, some tiles are thin, but +prove under no uncertain conditions that you're + +safe to fly. + +We went through this logic on everything. + +Some of these things had gates that said go +directly to fly. + +Others we had to go through. + +Others we had to pull off the vehicle and +densify and proof load and do a bunch of other + +things to prove that they were OK. + +We got there. + +Now we're into operations. + +We're just about out of time. + +I know. + +I've got three minutes left. + +Can I have all three? + +OK. + +Here is what we did. + +We did some pretty innovative things on this +thing, and I think I've shown you some of + +that stuff. + +But what were the surprises we had on the +first flight? + +Not very many. + +As we were going uphill, I told you about +the plume effect from the engines blocking + +the flow, that causes the pressure distribution +on the wing to be different than we designed + +for. + +The center pressure was further aft and outboard. + +That loaded up the wing more. + +It could not fly to the design conditions +that we needed to under worse case. + +And I'll tell you what we did on that. + +Well, let me just tell you right now. + +What we did was almost day-of-launch wind +analysis, loads analysis for the wings with + +load indicators in the wing to understand +what a specific flight regime was going to + +do for that vehicle. + +And we literally designed the trajectories +for the first six or eight or ten shuttle + +flights so it stayed within a reduced capability +of the vehicle. + +Because we characterized it so well, we could +do that. + +The other thing was the overpressure of the +vehicle, when the main engines let off there + +was an accumulation of hydrogen gas underneath +the vehicle. + +And as soon as the engines fired it ignited +that hydrogen and sent a big shockwave up + +the vehicle. + +It could have been pretty bad but it wasn't, +so we fixed that by isolating the isolation + +and also burning it off prior to engine ignition. + +And then we got some tile damage from external +tank. + +We fixed that. + +After about the second or third flight on +the external tank, we changed the foam process + +and controlled that. + +And so those were our only surprises. + +You remember the chart that I showed you of +all the combined environments on a tile? + +This is not politically correct what I'm going +to say, but I'm going to say it anyway. + +The shockwaves, the pressure, the out of plane +deformation, all that, you didn't see debris + +anyplace on that chart. + +Those tiles are not designed for debris, period. + +You can rationalize it. + +You can arm wave it. + +You can statistically analyze it. + +The vehicle is not designed to fly in debris. + +It can take every other thing it's designed +for, but it cannot take what it's not designed + +for. + +The engineers today have two choices. + +They can either eliminate the debris from +the external tank or, in my judgment, they + +can go back and recertify the tiles for the +expected debris. + +And that's probably not too big a deal, but +they cannot say we're ready to fly, going + +through a logic matrix like I did, until they +do that. + +OK, guys and gals. + +Here are some challenges for you. + +As you go through from the beginning of a +program, I would like you to be looking at + +this crew exploration vehicle, what other +parameters would you look at other than what + +I've shown you here and what tools would you +use? + +On the combined thermal mechanical, I think +a lot can be done on that. + +I don't know what all the computing capability +is today, but I think that you could really + +simplify and probably decrease the weight +of the vehicle by doing that. + +Could they be made more rugged? + +Yeah, they probably could. + +But be careful. + +This is a big systems engineering issue and +it's a political issue. + +And I'm going to get off the stage here in +one second. + +Should there be a dedicated crew escape system +or should the reliability be built in the + +vehicle? + +And I'll promise you that answer is not known. + +It may be known from a political standpoint +that you have to have a crew escape system, + +and that's OK. + +If that's a requirement, that's a requirement, +but in a total system crew safety reliability + +that's not obvious. + +It depends on what the design is and what +the reliability of the constituent elements + +are. + +How would you fix the ET? + +Put shrink wrap all over it. + +Another thing that's not part of the curriculum +here is political systems engineering. + +You can have the best engineering design in +the world, but if you don't have the political + +support in a program like this it doesn't +matter. + +How does political influence come into a systems +engineering thing, kind of like the crew escape + +system? + +Thank you. + +[APPLAUSE] Well, that was just super. + +This is hopefully the first of many lectures +which will take us to a much greater depth + +[then when we did the shuttle system?]. \ No newline at end of file diff --git a/kDhR4Zm53zc.txt b/kDhR4Zm53zc.txt new file mode 100644 index 0000000000000000000000000000000000000000..15a1150facff030597b8d42fe53d476029768990 --- /dev/null +++ b/kDhR4Zm53zc.txt @@ -0,0 +1,9272 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit MIT opencourseware + + align:start position:0% +of MIT courses visit MIT opencourseware + + + align:start position:0% +of MIT courses visit MIT opencourseware +at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu last time we were talking + + align:start position:0% +ocw.mit.edu last time we were talking + + + align:start position:0% +ocw.mit.edu last time we were talking +about binary search and I sort of left a + + align:start position:0% +about binary search and I sort of left a + + + align:start position:0% +about binary search and I sort of left a +promise to you which I need to pick up I + + align:start position:0% +promise to you which I need to pick up I + + + align:start position:0% +promise to you which I need to pick up I +want to remind mind you we're talking + + align:start position:0% +want to remind mind you we're talking + + + align:start position:0% +want to remind mind you we're talking +about search which is a very fundamental + + align:start position:0% +about search which is a very fundamental + + + align:start position:0% +about search which is a very fundamental +thing that we do in a whole lot of + + align:start position:0% +thing that we do in a whole lot of + + + align:start position:0% +thing that we do in a whole lot of +applications we want to go find things + + align:start position:0% +applications we want to go find things + + + align:start position:0% +applications we want to go find things +in some data set and I'll remind you + + align:start position:0% +in some data set and I'll remind you + + + align:start position:0% +in some data set and I'll remind you +that we sort of separated out two cases + + align:start position:0% +that we sort of separated out two cases + + + align:start position:0% +that we sort of separated out two cases +we said if we + + align:start position:0% +we said if we + + + align:start position:0% +we said if we +had an ordered + + align:start position:0% +had an ordered + + + align:start position:0% +had an ordered +list we could use binary search and we + + align:start position:0% +list we could use binary search and we + + + align:start position:0% +list we could use binary search and we +said that was logarithmic took log end + + align:start position:0% +said that was logarithmic took log end + + + align:start position:0% +said that was logarithmic took log end +time where ends the size of the of the + + align:start position:0% +time where ends the size of the of the + + + align:start position:0% +time where ends the size of the of the +list if it was an unordered list + + align:start position:0% +list if it was an unordered list + + + align:start position:0% +list if it was an unordered list +we were basically stuck with linear + + align:start position:0% +we were basically stuck with linear + + + align:start position:0% +we were basically stuck with linear +search got to walk through the whole + + align:start position:0% +search got to walk through the whole + + + align:start position:0% +search got to walk through the whole +list to see if the thing's there so that + + align:start position:0% +list to see if the thing's there so that + + + align:start position:0% +list to see if the thing's there so that +was of order + + align:start position:0% +was of order + + + align:start position:0% +was of order +in and then one of the things that I + + align:start position:0% +in and then one of the things that I + + + align:start position:0% +in and then one of the things that I +suggested was that if we could figure + + align:start position:0% +suggested was that if we could figure + + + align:start position:0% +suggested was that if we could figure +out some way to order it and in + + align:start position:0% +out some way to order it and in + + + align:start position:0% +out some way to order it and in +particular if we could order it in N log + + align:start position:0% +particular if we could order it in N log + + + align:start position:0% +particular if we could order it in N log +n + + align:start position:0% + + + + align:start position:0% + +time and we still haven't done that but + + align:start position:0% +time and we still haven't done that but + + + align:start position:0% +time and we still haven't done that but +if we could do that then we said the + + align:start position:0% +if we could do that then we said the + + + align:start position:0% +if we could do that then we said the +complexity changed a little bit but + + align:start position:0% +complexity changed a little bit but + + + align:start position:0% +complexity changed a little bit but +changed in a way that I want to remind + + align:start position:0% +changed in a way that I want to remind + + + align:start position:0% +changed in a way that I want to remind +you and the change was that in this case + + align:start position:0% +you and the change was that in this case + + + align:start position:0% +you and the change was that in this case +if I'm doing a single search I've got a + + align:start position:0% +if I'm doing a single search I've got a + + + align:start position:0% +if I'm doing a single search I've got a +choice I could still do the linear case + + align:start position:0% +choice I could still do the linear case + + + align:start position:0% +choice I could still do the linear case +which is order + + align:start position:0% +which is order + + + align:start position:0% +which is order +n or I could say look take the list + + align:start position:0% +n or I could say look take the list + + + align:start position:0% +n or I could say look take the list +let's sort it and then search it but in + + align:start position:0% +let's sort it and then search it but in + + + align:start position:0% +let's sort it and then search it but in +that case we said well to sort + + align:start position:0% +that case we said well to sort + + + align:start position:0% +that case we said well to sort +it was going to take n log n time + + align:start position:0% +it was going to take n log n time + + + align:start position:0% +it was going to take n log n time +assuming I can do that once I have it + + align:start position:0% +assuming I can do that once I have it + + + align:start position:0% +assuming I can do that once I have it +sort it I can search + + align:start position:0% +sort it I can search + + + align:start position:0% +sort it I can search +it in log end + + align:start position:0% +it in log end + + + align:start position:0% +it in log end +time but that still isn't as good as + + align:start position:0% +time but that still isn't as good as + + + align:start position:0% +time but that still isn't as good as +just doing n and this led to this idea + + align:start position:0% +just doing n and this led to this idea + + + align:start position:0% +just doing n and this led to this idea +of + + align:start position:0% + + + + align:start position:0% + +amortization which is I need to not only + + align:start position:0% +amortization which is I need to not only + + + align:start position:0% +amortization which is I need to not only +factor in the cost but how am I going to + + align:start position:0% +factor in the cost but how am I going to + + + align:start position:0% +factor in the cost but how am I going to +use it and typically I'm not going to + + align:start position:0% +use it and typically I'm not going to + + + align:start position:0% +use it and typically I'm not going to +just search Once in a list I'm going to + + align:start position:0% +just search Once in a list I'm going to + + + align:start position:0% +just search Once in a list I'm going to +search multiple times so if I have to do + + align:start position:0% +search multiple times so if I have to do + + + align:start position:0% +search multiple times so if I have to do +K + + align:start position:0% +K + + + align:start position:0% +K +searches then in the linear case I got + + align:start position:0% +searches then in the linear case I got + + + align:start position:0% +searches then in the linear case I got +to do order N Things K times it's order + + align:start position:0% +to do order N Things K times it's order + + + align:start position:0% +to do order N Things K times it's order +K in whereas in the ordered + + align:start position:0% +K in whereas in the ordered + + + align:start position:0% +K in whereas in the ordered +case I need to get sorted which is still + + align:start position:0% +case I need to get sorted which is still + + + align:start position:0% +case I need to get sorted which is still +n log n but then the search is only log + + align:start position:0% +n log n but then the search is only log + + + align:start position:0% +n log n but then the search is only log +n and I need to do K of + + align:start position:0% +n and I need to do K of + + + align:start position:0% +n and I need to do K of +those and we suggested while this is + + align:start position:0% +those and we suggested while this is + + + align:start position:0% +those and we suggested while this is +better than + + align:start position:0% +better than + + + align:start position:0% +better than +that this is certainly better than + + align:start position:0% +that this is certainly better than + + + align:start position:0% +that this is certainly better than +that n plus K All Times log n is in + + align:start position:0% +that n plus K All Times log n is in + + + align:start position:0% +that n plus K All Times log n is in +general going to be much better than K * + + align:start position:0% +general going to be much better than K * + + + align:start position:0% +general going to be much better than K * +n depends on n and K but obviously Zen + + align:start position:0% +n depends on n and K but obviously Zen + + + align:start position:0% +n depends on n and K but obviously Zen +gets big that one's going to be + + align:start position:0% +gets big that one's going to be + + + align:start position:0% +gets big that one's going to be +better and that's just a way of + + align:start position:0% +better and that's just a way of + + + align:start position:0% +better and that's just a way of +reminding you that um we want to think + + align:start position:0% +reminding you that um we want to think + + + align:start position:0% +reminding you that um we want to think +carefully about what are the things + + align:start position:0% +carefully about what are the things + + + align:start position:0% +carefully about what are the things +we're trying to measure when we talk + + align:start position:0% +we're trying to measure when we talk + + + align:start position:0% +we're trying to measure when we talk +about complexity here it's both the size + + align:start position:0% +about complexity here it's both the size + + + align:start position:0% +about complexity here it's both the size +of the thing and how often am I going to + + align:start position:0% +of the thing and how often am I going to + + + align:start position:0% +of the thing and how often am I going to +use it and there's some + + align:start position:0% +use it and there's some + + + align:start position:0% +use it and there's some +trade-offs but I still haven't said how + + align:start position:0% +trade-offs but I still haven't said how + + + align:start position:0% +trade-offs but I still haven't said how +am I going to get an N log n sorting + + align:start position:0% +am I going to get an N log n sorting + + + align:start position:0% +am I going to get an N log n sorting +algorithm and that's what I want to do + + align:start position:0% +algorithm and that's what I want to do + + + align:start position:0% +algorithm and that's what I want to do +today one of the two things I want to do + + align:start position:0% +today one of the two things I want to do + + + align:start position:0% +today one of the two things I want to do +today right to set the stage for this + + align:start position:0% +today right to set the stage for this + + + align:start position:0% +today right to set the stage for this +let's go back just for a second to + + align:start position:0% +let's go back just for a second to + + + align:start position:0% +let's go back just for a second to +binary + + align:start position:0% +binary + + + align:start position:0% +binary +search the end of the lecture I said + + align:start position:0% +search the end of the lecture I said + + + align:start position:0% +search the end of the lecture I said +binary search was an example + + align:start position:0% + + + + align:start position:0% + +of a divide and conquer + + align:start position:0% + + + + align:start position:0% + +algorithm sort of an a till of the Hun + + align:start position:0% +algorithm sort of an a till of the Hun + + + align:start position:0% +algorithm sort of an a till of the Hun +kind of approach to doing things if you + + align:start position:0% +kind of approach to doing things if you + + + align:start position:0% +kind of approach to doing things if you +like so let me say this boy I could have + + align:start position:0% +like so let me say this boy I could have + + + align:start position:0% +like so let me say this boy I could have +made a really bad political joke there + + align:start position:0% +made a really bad political joke there + + + align:start position:0% +made a really bad political joke there +which I will forego right so let's say + + align:start position:0% +which I will forego right so let's say + + + align:start position:0% +which I will forego right so let's say +what this actually means divide and + + align:start position:0% +what this actually means divide and + + + align:start position:0% +what this actually means divide and +conquer divide and conquer says + + align:start position:0% +conquer divide and conquer says + + + align:start position:0% +conquer divide and conquer says +basically do the following split the + + align:start position:0% + + + + align:start position:0% + +problem into several + + align:start position:0% + + + + align:start position:0% + +sub + + align:start position:0% + + + + align:start position:0% + +problems of the same + + align:start position:0% + + + + align:start position:0% + +type okay I'll come back in a second to + + align:start position:0% +type okay I'll come back in a second to + + + align:start position:0% +type okay I'll come back in a second to +how binary search matches in that but + + align:start position:0% +how binary search matches in that but + + + align:start position:0% +how binary search matches in that but +that's what we're going to do for each + + align:start position:0% +that's what we're going to do for each + + + align:start position:0% +that's what we're going to do for each +of those sub + + align:start position:0% +of those sub + + + align:start position:0% +of those sub +problems going to solve them + + align:start position:0% + + + + align:start position:0% + +independently and then we're going to + + align:start position:0% +independently and then we're going to + + + align:start position:0% +independently and then we're going to +combine those Solutions + + align:start position:0% + + + + align:start position:0% + +and it's called divide and conquer for + + align:start position:0% +and it's called divide and conquer for + + + align:start position:0% +and it's called divide and conquer for +the obvious reason I'm going to divide + + align:start position:0% +the obvious reason I'm going to divide + + + align:start position:0% +the obvious reason I'm going to divide +it up into sub problems with the hope + + align:start position:0% +it up into sub problems with the hope + + + align:start position:0% +it up into sub problems with the hope +that those sub problems get easier going + + align:start position:0% +that those sub problems get easier going + + + align:start position:0% +that those sub problems get easier going +to be easier to conquer if you like and + + align:start position:0% +to be easier to conquer if you like and + + + align:start position:0% +to be easier to conquer if you like and +then I'm going to merge them back now in + + align:start position:0% +then I'm going to merge them back now in + + + align:start position:0% +then I'm going to merge them back now in +the binary search case in some sense + + align:start position:0% +the binary search case in some sense + + + align:start position:0% +the binary search case in some sense +this was a little bit trivial what what + + align:start position:0% +this was a little bit trivial what what + + + align:start position:0% +this was a little bit trivial what what +trival right trivial blah what was the + + align:start position:0% +trival right trivial blah what was the + + + align:start position:0% +trival right trivial blah what was the +divide the Divide was breaking a big + + align:start position:0% +divide the Divide was breaking a big + + + align:start position:0% +divide the Divide was breaking a big +search up into a half a search we + + align:start position:0% +search up into a half a search we + + + align:start position:0% +search up into a half a search we +actually threw half of the list away and + + align:start position:0% +actually threw half of the list away and + + + align:start position:0% +actually threw half of the list away and +we kept dividing it down + + align:start position:0% +we kept dividing it down + + + align:start position:0% +we kept dividing it down +until ultimately we got something of + + align:start position:0% +until ultimately we got something of + + + align:start position:0% +until ultimately we got something of +size one to search that's really easy + + align:start position:0% +size one to search that's really easy + + + align:start position:0% +size one to search that's really easy +the combination was also sort of trivial + + align:start position:0% +the combination was also sort of trivial + + + align:start position:0% +the combination was also sort of trivial +in this case because the solution to the + + align:start position:0% +in this case because the solution to the + + + align:start position:0% +in this case because the solution to the +sub problem was in fact the solution to + + align:start position:0% +sub problem was in fact the solution to + + + align:start position:0% +sub problem was in fact the solution to +the larger problem okay but there's the + + align:start position:0% +the larger problem okay but there's the + + + align:start position:0% +the larger problem okay but there's the +idea of divide and conquer I'm going to + + align:start position:0% +idea of divide and conquer I'm going to + + + align:start position:0% +idea of divide and conquer I'm going to +use exactly that same idea to tackle + + align:start position:0% +use exactly that same idea to tackle + + + align:start position:0% +use exactly that same idea to tackle +sort again I got an unordered list of n + + align:start position:0% +sort again I got an unordered list of n + + + align:start position:0% +sort again I got an unordered list of n +elements I want to sort it into a + + align:start position:0% +elements I want to sort it into a + + + align:start position:0% +elements I want to sort it into a +obviously into a sorted list in that + + align:start position:0% +obviously into a sorted list in that + + + align:start position:0% +obviously into a sorted list in that +particular + + align:start position:0% +particular + + + align:start position:0% +particular +algorithm is actually a really nice + + align:start position:0% +algorithm is actually a really nice + + + align:start position:0% +algorithm is actually a really nice +algorithm called merge + + align:start position:0% + + + + align:start position:0% + +sort and it's actually a fairly old + + align:start position:0% +sort and it's actually a fairly old + + + align:start position:0% +sort and it's actually a fairly old +algorithm it was invented in 1945 by + + align:start position:0% +algorithm it was invented in 1945 by + + + align:start position:0% +algorithm it was invented in 1945 by +John Von noyman one of the + + align:start position:0% +John Von noyman one of the + + + align:start position:0% +John Von noyman one of the +pioneers of computer + + align:start position:0% +pioneers of computer + + + align:start position:0% +pioneers of computer +science and here's the idea behind merge + + align:start position:0% +science and here's the idea behind merge + + + align:start position:0% +science and here's the idea behind merge +sort actually I'm going to come into it + + align:start position:0% +sort actually I'm going to come into it + + + align:start position:0% +sort actually I'm going to come into it +I'm going to back into it in a funny way + + align:start position:0% +I'm going to back into it in a funny way + + + align:start position:0% +I'm going to back into it in a funny way +let's assume that I could somehow get to + + align:start position:0% +let's assume that I could somehow get to + + + align:start position:0% +let's assume that I could somehow get to +the stage where I've got two sorted + + align:start position:0% +the stage where I've got two sorted + + + align:start position:0% +the stage where I've got two sorted +lists how hard does it work or how much + + align:start position:0% +lists how hard does it work or how much + + + align:start position:0% +lists how hard does it work or how much +work do I have to do to actually merge + + align:start position:0% +work do I have to do to actually merge + + + align:start position:0% +work do I have to do to actually merge +them together all right so let me give + + align:start position:0% +them together all right so let me give + + + align:start position:0% +them together all right so let me give +you an example suppose I want to merge + + align:start position:0% +you an example suppose I want to merge + + + align:start position:0% +you an example suppose I want to merge +two + + align:start position:0% +two + + + align:start position:0% +two +lists and they're + + align:start position:0% +lists and they're + + + align:start position:0% +lists and they're +sorted just to give you an example + + align:start position:0% +sorted just to give you an example + + + align:start position:0% +sorted just to give you an example +here's one + + align:start position:0% + + + + align:start position:0% + +list right 312 17 + + align:start position:0% +list right 312 17 + + + align:start position:0% +list right 312 17 +24 God bless you here's another list 1 2 + + align:start position:0% +24 God bless you here's another list 1 2 + + + align:start position:0% +24 God bless you here's another list 1 2 + + align:start position:0% + + + align:start position:0% +30 I haven't said how I'm going to get + + align:start position:0% +30 I haven't said how I'm going to get + + + align:start position:0% +30 I haven't said how I'm going to get +those sorted lists but imagine I had two + + align:start position:0% +those sorted lists but imagine I had two + + + align:start position:0% +those sorted lists but imagine I had two +sorted lists like that how hard is it to + + align:start position:0% +sorted lists like that how hard is it to + + + align:start position:0% +sorted lists like that how hard is it to +merge them well it's pretty easy right I + + align:start position:0% +merge them well it's pretty easy right I + + + align:start position:0% +merge them well it's pretty easy right I +start at the beginning of each list and + + align:start position:0% +start at the beginning of each list and + + + align:start position:0% +start at the beginning of each list and +I say is one less than three sure so + + align:start position:0% +I say is one less than three sure so + + + align:start position:0% +I say is one less than three sure so +that says one should be the first + + align:start position:0% +that says one should be the first + + + align:start position:0% +that says one should be the first +element in my merge + + align:start position:0% +element in my merge + + + align:start position:0% +element in my merge +list now compare the first element in + + align:start position:0% +list now compare the first element in + + + align:start position:0% +list now compare the first element in +each of these lists two is less than + + align:start position:0% +each of these lists two is less than + + + align:start position:0% +each of these lists two is less than +three so two ought to be the next + + align:start position:0% +three so two ought to be the next + + + align:start position:0% +three so two ought to be the next +element of the list and you get the idea + + align:start position:0% +element of the list and you get the idea + + + align:start position:0% +element of the list and you get the idea +what do I do next I'm going to compare + + align:start position:0% +what do I do next I'm going to compare + + + align:start position:0% +what do I do next I'm going to compare +three against four + + align:start position:0% +three against four + + + align:start position:0% +three against four +three is the smallest one then I'm going + + align:start position:0% +three is the smallest one then I'm going + + + align:start position:0% +three is the smallest one then I'm going +to compare four against 12 which is + + align:start position:0% +to compare four against 12 which is + + + align:start position:0% +to compare four against 12 which is +going to give me four and then what do I + + align:start position:0% +going to give me four and then what do I + + + align:start position:0% +going to give me four and then what do I +have to do 12 against 30 12 is + + align:start position:0% + + + + align:start position:0% + +smaller take that out 17 against + + align:start position:0% + + + + align:start position:0% + +30 24 against + + align:start position:0% + + + + align:start position:0% + +30 and by this stage I got nothing left + + align:start position:0% +30 and by this stage I got nothing left + + + align:start position:0% +30 and by this stage I got nothing left +in this one so I just add the rest of + + align:start position:0% +in this one so I just add the rest of + + + align:start position:0% +in this one so I just add the rest of +that l in + + align:start position:0% +that l in + + + align:start position:0% +that l in +wow I can sort two lists or I can merge + + align:start position:0% +wow I can sort two lists or I can merge + + + align:start position:0% +wow I can sort two lists or I can merge +two lists I said it poorly what's the + + align:start position:0% +two lists I said it poorly what's the + + + align:start position:0% +two lists I said it poorly what's the +point how many operations did it take me + + align:start position:0% +point how many operations did it take me + + + align:start position:0% +point how many operations did it take me +to do this seven comparisons right I got + + align:start position:0% +to do this seven comparisons right I got + + + align:start position:0% +to do this seven comparisons right I got +eight elements it took me seven + + align:start position:0% + + + + align:start position:0% + +comparisons because I can take advantage + + align:start position:0% +comparisons because I can take advantage + + + align:start position:0% +comparisons because I can take advantage +of the fact I know I only ever have to + + align:start position:0% +of the fact I know I only ever have to + + + align:start position:0% +of the fact I know I only ever have to +look at the first element of each + + align:start position:0% +look at the first element of each + + + align:start position:0% +look at the first element of each +sublist those are the only things I need + + align:start position:0% +sublist those are the only things I need + + + align:start position:0% +sublist those are the only things I need +to compare and when I run out of one + + align:start position:0% +to compare and when I run out of one + + + align:start position:0% +to compare and when I run out of one +list I just add the rest of the list in + + align:start position:0% +list I just add the rest of the list in + + + align:start position:0% +list I just add the rest of the list in +okay what's the order of complexity + + align:start position:0% +okay what's the order of complexity + + + align:start position:0% +okay what's the order of complexity +of + + align:start position:0% +of + + + align:start position:0% +of +merging I heard it somewhere very + + align:start position:0% +merging I heard it somewhere very + + + align:start position:0% +merging I heard it somewhere very +quietly sorry n thank you linear + + align:start position:0% +quietly sorry n thank you linear + + + align:start position:0% +quietly sorry n thank you linear +absolutely right and what's n by the way + + align:start position:0% +absolutely right and what's n by the way + + + align:start position:0% +absolutely right and what's n by the way +here what's it + + align:start position:0% + + + + align:start position:0% + +measuring in both lists right so this is + + align:start position:0% +measuring in both lists right so this is + + + align:start position:0% +measuring in both lists right so this is +linear order n and n is the sum of the + + align:start position:0% +linear order n and n is the sum of the + + + align:start position:0% +linear order n and n is the sum of the +element or sorry of the number of + + align:start position:0% +element or sorry of the number of + + + align:start position:0% +element or sorry of the number of +elements in each list + + align:start position:0% + + + + align:start position:0% + +okay so I thought I was going to back my + + align:start position:0% +okay so I thought I was going to back my + + + align:start position:0% +okay so I thought I was going to back my +way into this that gives + + align:start position:0% +way into this that gives + + + align:start position:0% +way into this that gives +me a way to merge things so here's what + + align:start position:0% +me a way to merge things so here's what + + + align:start position:0% +me a way to merge things so here's what +merge sort would do right merge + + align:start position:0% +merge sort would do right merge + + + align:start position:0% +merge sort would do right merge +sort takes this + + align:start position:0% +sort takes this + + + align:start position:0% +sort takes this +idea of divide and + + align:start position:0% +idea of divide and + + + align:start position:0% +idea of divide and +conquer and it does the following it + + align:start position:0% +conquer and it does the following it + + + align:start position:0% +conquer and it does the following it +says let's divide the + + align:start position:0% + + + + align:start position:0% + +list in + + align:start position:0% +list in + + + align:start position:0% +list in +half there's the the div divide and + + align:start position:0% +half there's the the div divide and + + + align:start position:0% +half there's the the div divide and +conquer and let's keep dividing each of + + align:start position:0% +conquer and let's keep dividing each of + + + align:start position:0% +conquer and let's keep dividing each of +those lists in half until we get down to + + align:start position:0% +those lists in half until we get down to + + + align:start position:0% +those lists in half until we get down to +something that's really easy to sort + + align:start position:0% +something that's really easy to sort + + + align:start position:0% +something that's really easy to sort +what's the simplest thing to + + align:start position:0% +what's the simplest thing to + + + align:start position:0% +what's the simplest thing to +sort list to size one right right so + + align:start position:0% + + + + align:start position:0% + +continue + + align:start position:0% +continue + + + align:start position:0% +continue +until we have Singleton + + align:start position:0% + + + + align:start position:0% + +lists once I got list of size one + + align:start position:0% +lists once I got list of size one + + + align:start position:0% +lists once I got list of size one +they're sorted + + align:start position:0% +they're sorted + + + align:start position:0% +they're sorted +and then combine them and combine them + + align:start position:0% +and then combine them and combine them + + + align:start position:0% +and then combine them and combine them +by doing a + + align:start position:0% +by doing a + + + align:start position:0% +by doing a +merge the + + align:start position:0% + + + + align:start position:0% + +sublists and again you see that flavor + + align:start position:0% +sublists and again you see that flavor + + + align:start position:0% +sublists and again you see that flavor +I'm going to just keep dividing it up + + align:start position:0% +I'm going to just keep dividing it up + + + align:start position:0% +I'm going to just keep dividing it up +until I get something really easy and + + align:start position:0% +until I get something really easy and + + + align:start position:0% +until I get something really easy and +then I'm going to combine and this is + + align:start position:0% +then I'm going to combine and this is + + + align:start position:0% +then I'm going to combine and this is +different than binary search now the + + align:start position:0% +different than binary search now the + + + align:start position:0% +different than binary search now the +combine is going to have to do some work + + align:start position:0% +combine is going to have to do some work + + + align:start position:0% +combine is going to have to do some work +so I've given you a piece of code that + + align:start position:0% +so I've given you a piece of code that + + + align:start position:0% +so I've given you a piece of code that +does this I'm going to come back to it + + align:start position:0% +does this I'm going to come back to it + + + align:start position:0% +does this I'm going to come back to it +in a second but it's up there but what + + align:start position:0% +in a second but it's up there but what + + + align:start position:0% +in a second but it's up there but what +I'd like to do is to try and give you a + + align:start position:0% +I'd like to do is to try and give you a + + + align:start position:0% +I'd like to do is to try and give you a +sort of a little simulation of how this + + align:start position:0% +sort of a little simulation of how this + + + align:start position:0% +sort of a little simulation of how this +would work and I was going to originally + + align:start position:0% +would work and I was going to originally + + + align:start position:0% +would work and I was going to originally +make the Tas come up here and do it but + + align:start position:0% +make the Tas come up here and do it but + + + align:start position:0% +make the Tas come up here and do it but +I don't have enough Tas to do a full + + align:start position:0% +I don't have enough Tas to do a full + + + align:start position:0% +I don't have enough Tas to do a full +merge sort so I'm hoping and I also I + + align:start position:0% +merge sort so I'm hoping and I also I + + + align:start position:0% +merge sort so I'm hoping and I also I +have these really Hightech props I spent + + align:start position:0% +have these really Hightech props I spent + + + align:start position:0% +have these really Hightech props I spent +tons and tons of Department money on + + align:start position:0% +tons and tons of Department money on + + + align:start position:0% +tons and tons of Department money on +them as you can see I hope you can see + + align:start position:0% +them as you can see I hope you can see + + + align:start position:0% +them as you can see I hope you can see +this because I'm going to try and + + align:start position:0% +this because I'm going to try and + + + align:start position:0% +this because I'm going to try and +simulate what a merge sort does I've got + + align:start position:0% +simulate what a merge sort does I've got + + + align:start position:0% +simulate what a merge sort does I've got +eight things I want to sort here and + + align:start position:0% +eight things I want to sort here and + + + align:start position:0% +eight things I want to sort here and +those initially start out here at top + + align:start position:0% +those initially start out here at top + + + align:start position:0% +those initially start out here at top +level first step is divide them in + + align:start position:0% + + + + align:start position:0% + +half right and I should have had them + + align:start position:0% +half right and I should have had them + + + align:start position:0% +half right and I should have had them +marker here remember I need to come back + + align:start position:0% +marker here remember I need to come back + + + align:start position:0% +marker here remember I need to come back +there not yet done what do I do divide + + align:start position:0% +there not yet done what do I do divide + + + align:start position:0% +there not yet done what do I do divide +them in half + + align:start position:0% + + + + align:start position:0% + +again + + align:start position:0% +again + + + align:start position:0% +again +okay you know if I had like shells and + + align:start position:0% +okay you know if I had like shells and + + + align:start position:0% +okay you know if I had like shells and +peas here I could make some more money + + align:start position:0% +peas here I could make some more money + + + align:start position:0% +peas here I could make some more money +right all right what do I do I divide + + align:start position:0% +right all right what do I do I divide + + + align:start position:0% +right all right what do I do I divide +them in half one more + + align:start position:0% + + + + align:start position:0% + +time let me cluster them because really + + align:start position:0% +time let me cluster them because really + + + align:start position:0% +time let me cluster them because really +what I have sorry separate them out I've + + align:start position:0% +what I have sorry separate them out I've + + + align:start position:0% +what I have sorry separate them out I've +gone from one problem size eight down to + + align:start position:0% +gone from one problem size eight down to + + + align:start position:0% +gone from one problem size eight down to +eight problems of size one at this stage + + align:start position:0% +eight problems of size one at this stage + + + align:start position:0% +eight problems of size one at this stage +I'm at my Singleton case so this is easy + + align:start position:0% +I'm at my Singleton case so this is easy + + + align:start position:0% +I'm at my Singleton case so this is easy +what do I do I merge and the merge is + + align:start position:0% +what do I do I merge and the merge is + + + align:start position:0% +what do I do I merge and the merge is +put them in + + align:start position:0% + + + + align:start position:0% + +order okay what do I do next obvious + + align:start position:0% +order okay what do I do next obvious + + + align:start position:0% +order okay what do I do next obvious +thing I merg these and that as we saw + + align:start position:0% +thing I merg these and that as we saw + + + align:start position:0% +thing I merg these and that as we saw +was a nice linear operation it's fun to + + align:start position:0% +was a nice linear operation it's fun to + + + align:start position:0% +was a nice linear operation it's fun to +do it upside down + + align:start position:0% + + + + align:start position:0% + +and then one more merch which is I take + + align:start position:0% +and then one more merch which is I take + + + align:start position:0% +and then one more merch which is I take +the smallest elements of each one + + align:start position:0% + + + + align:start position:0% + +until get to where I + + align:start position:0% +until get to where I + + + align:start position:0% +until get to where I +want wow aren't you + + align:start position:0% +want wow aren't you + + + align:start position:0% +want wow aren't you +impressed okay no please don't clap not + + align:start position:0% +impressed okay no please don't clap not + + + align:start position:0% +impressed okay no please don't clap not +for that one now let me do it a second + + align:start position:0% +for that one now let me do it a second + + + align:start position:0% +for that one now let me do it a second +time to show you that that's sorry I'm + + align:start position:0% +time to show you that that's sorry I'm + + + align:start position:0% +time to show you that that's sorry I'm +saying this poorly let me say it again + + align:start position:0% +saying this poorly let me say it again + + + align:start position:0% +saying this poorly let me say it again +that's the general idea what was what + + align:start position:0% +that's the general idea what was what + + + align:start position:0% +that's the general idea what was what +should you see out of that I just kept + + align:start position:0% +should you see out of that I just kept + + + align:start position:0% +should you see out of that I just kept +subdividing down till I got really easy + + align:start position:0% +subdividing down till I got really easy + + + align:start position:0% +subdividing down till I got really easy +problems and then I combined them back I + + align:start position:0% +problems and then I combined them back I + + + align:start position:0% +problems and then I combined them back I +actually misled you slightly there or + + align:start position:0% +actually misled you slightly there or + + + align:start position:0% +actually misled you slightly there or +maybe a lot because I did it in parallel + + align:start position:0% +maybe a lot because I did it in parallel + + + align:start position:0% +maybe a lot because I did it in parallel +and in fact let me just Shuffle these up + + align:start position:0% +and in fact let me just Shuffle these up + + + align:start position:0% +and in fact let me just Shuffle these up +a little bit really what's going to + + align:start position:0% +a little bit really what's going to + + + align:start position:0% +a little bit really what's going to +happen here because this is a sequential + + align:start position:0% +happen here because this is a sequential + + + align:start position:0% +happen here because this is a sequential +computer is that we're going to start + + align:start position:0% +computer is that we're going to start + + + align:start position:0% +computer is that we're going to start +off up + + align:start position:0% +off up + + + align:start position:0% +off up +here at top level we're going to divide + + align:start position:0% +here at top level we're going to divide + + + align:start position:0% +here at top level we're going to divide +into + + align:start position:0% + + + + align:start position:0% + +half and then we're going to do the + + align:start position:0% +half and then we're going to do the + + + align:start position:0% +half and then we're going to do the +complete subdivision and merge here + + align:start position:0% +complete subdivision and merge here + + + align:start position:0% +complete subdivision and merge here +before we ever come back and do this one + + align:start position:0% +before we ever come back and do this one + + + align:start position:0% +before we ever come back and do this one +right we're going to do a + + align:start position:0% +right we're going to do a + + + align:start position:0% +right we're going to do a +division here and then a division there + + align:start position:0% +division here and then a division there + + + align:start position:0% +division here and then a division there +at that stage we can merge these and + + align:start position:0% +at that stage we can merge these and + + + align:start position:0% +at that stage we can merge these and +then take this down do the division + + align:start position:0% +then take this down do the division + + + align:start position:0% +then take this down do the division +merge and bring them back whoops sorry + + align:start position:0% +merge and bring them back whoops sorry + + + align:start position:0% +merge and bring them back whoops sorry +about that and bring them back + + align:start position:0% +about that and bring them back + + + align:start position:0% +about that and bring them back +up okay let me show you an example by + + align:start position:0% +up okay let me show you an example by + + + align:start position:0% +up okay let me show you an example by +running that I've got a little list I've + + align:start position:0% +running that I've got a little list I've + + + align:start position:0% +running that I've got a little list I've +made here called + + align:start position:0% +made here called + + + align:start position:0% +made here called +test let's run merge sword on + + align:start position:0% +test let's run merge sword on + + + align:start position:0% +test let's run merge sword on +it then we'll look at the + + align:start position:0% + + + + align:start position:0% + +code okay what I would like you to see + + align:start position:0% +code okay what I would like you to see + + + align:start position:0% +code okay what I would like you to see +is I've been printing out as I went + + align:start position:0% +is I've been printing out as I went + + + align:start position:0% +is I've been printing out as I went +along actually that's backup slightly + + align:start position:0% +along actually that's backup slightly + + + align:start position:0% +along actually that's backup slightly +and look at the code there's merge + + align:start position:0% +and look at the code there's merge + + + align:start position:0% +and look at the code there's merge +sort takes in a list what does it say to + + align:start position:0% +sort takes in a list what does it say to + + + align:start position:0% +sort takes in a list what does it say to +do it says check to see if I'm in that + + align:start position:0% +do it says check to see if I'm in that + + + align:start position:0% +do it says check to see if I'm in that +base case it's the list of less of + + align:start position:0% +base case it's the list of less of + + + align:start position:0% +base case it's the list of less of +length less than two is it one basically + + align:start position:0% +length less than two is it one basically + + + align:start position:0% +length less than two is it one basically +in which case just return a copy of the + + align:start position:0% +in which case just return a copy of the + + + align:start position:0% +in which case just return a copy of the +list okay that's the simple case + + align:start position:0% +list okay that's the simple case + + + align:start position:0% +list okay that's the simple case +otherwise notice what it says to do it + + align:start position:0% +otherwise notice what it says to do it + + + align:start position:0% +otherwise notice what it says to do it +says find the midpoint and split the + + align:start position:0% +says find the midpoint and split the + + + align:start position:0% +says find the midpoint and split the +list in half right copy of the back end + + align:start position:0% +list in half right copy of the back end + + + align:start position:0% +list in half right copy of the back end +sorry copy of the left side copy of the + + align:start position:0% +sorry copy of the left side copy of the + + + align:start position:0% +sorry copy of the left side copy of the +right side run merge sour on those by + + align:start position:0% +right side run merge sour on those by + + + align:start position:0% +right side run merge sour on those by +induction if it does the right thing I'm + + align:start position:0% +induction if it does the right thing I'm + + + align:start position:0% +induction if it does the right thing I'm +going to get back two lists and I'm + + align:start position:0% +going to get back two lists and I'm + + + align:start position:0% +going to get back two lists and I'm +going to then merge them together and + + align:start position:0% +going to then merge them together and + + + align:start position:0% +going to then merge them together and +notice what I'm going to do I'm going to + + align:start position:0% +notice what I'm going to do I'm going to + + + align:start position:0% +notice what I'm going to do I'm going to +print here the list as we go into it and + + align:start position:0% +print here the list as we go into it and + + + align:start position:0% +print here the list as we go into it and +a print of the merge when we're done and + + align:start position:0% +a print of the merge when we're done and + + + align:start position:0% +a print of the merge when we're done and +then just return that merge up here + + align:start position:0% +then just return that merge up here + + + align:start position:0% +then just return that merge up here +there's a little more code there I'll + + align:start position:0% +there's a little more code there I'll + + + align:start position:0% +there's a little more code there I'll +let you dis grock it but you can see + + align:start position:0% +let you dis grock it but you can see + + + align:start position:0% +let you dis grock it but you can see +it's basically doing what I did over + + align:start position:0% +it's basically doing what I did over + + + align:start position:0% +it's basically doing what I did over +there setting up two indices for the two + + align:start position:0% +there setting up two indices for the two + + + align:start position:0% +there setting up two indices for the two +sublist is just walking down finding the + + align:start position:0% +sublist is just walking down finding the + + + align:start position:0% +sublist is just walking down finding the +smallest element putting it into a new + + align:start position:0% +smallest element putting it into a new + + + align:start position:0% +smallest element putting it into a new +list when it gets to the end one of the + + align:start position:0% +list when it gets to the end one of the + + + align:start position:0% +list when it gets to the end one of the +lists it skips to the next part and only + + align:start position:0% +lists it skips to the next part and only + + + align:start position:0% +lists it skips to the next part and only +one of these two pieces will get called + + align:start position:0% +one of these two pieces will get called + + + align:start position:0% +one of these two pieces will get called +because only one of them is going to + + align:start position:0% +because only one of them is going to + + + align:start position:0% +because only one of them is going to +have things left over it's going to add + + align:start position:0% +have things left over it's going to add + + + align:start position:0% +have things left over it's going to add +the other pieces + + align:start position:0% +the other pieces + + + align:start position:0% +the other pieces +in okay if you look at that then let's + + align:start position:0% +in okay if you look at that then let's + + + align:start position:0% +in okay if you look at that then let's +look at what happened when we ran this + + align:start position:0% +look at what happened when we ran this + + + align:start position:0% +look at what happened when we ran this +right we started off with a call with + + align:start position:0% +right we started off with a call with + + + align:start position:0% +right we started off with a call with +that list aha split it in half it's + + align:start position:0% +that list aha split it in half it's + + + align:start position:0% +that list aha split it in half it's +going down the left side of this that + + align:start position:0% +going down the left side of this that + + + align:start position:0% +going down the left side of this that +got split in half and that got split in + + align:start position:0% +got split in half and that got split in + + + align:start position:0% +got split in half and that got split in +half until I got to a list of size one + + align:start position:0% +half until I got to a list of size one + + + align:start position:0% +half until I got to a list of size one +there's the first list of size one + + align:start position:0% +there's the first list of size one + + + align:start position:0% +there's the first list of size one +there's the second list to size one so I + + align:start position:0% +there's the second list to size one so I + + + align:start position:0% +there's the second list to size one so I +merg them it's now in the right order + + align:start position:0% +merg them it's now in the right order + + + align:start position:0% +merg them it's now in the right order +and that's coming from right there + + align:start position:0% +and that's coming from right there + + + align:start position:0% +and that's coming from right there +having done that it goes back up and + + align:start position:0% +having done that it goes back up and + + + align:start position:0% +having done that it goes back up and +picks the second subl list which came + + align:start position:0% +picks the second subl list which came + + + align:start position:0% +picks the second subl list which came +actually I should have said came from + + align:start position:0% +actually I should have said came from + + + align:start position:0% +actually I should have said came from +there right gets it down to base case + + align:start position:0% +there right gets it down to base case + + + align:start position:0% +there right gets it down to base case +merges it when these two merges are done + + align:start position:0% +merges it when these two merges are done + + + align:start position:0% +merges it when these two merges are done +we're basically at a stage in that + + align:start position:0% +we're basically at a stage in that + + + align:start position:0% +we're basically at a stage in that +Branch where we can now merge those two + + align:start position:0% +Branch where we can now merge those two + + + align:start position:0% +Branch where we can now merge those two +together which gives us that and it goes + + align:start position:0% +together which gives us that and it goes + + + align:start position:0% +together which gives us that and it goes +through the rest of + + align:start position:0% +through the rest of + + + align:start position:0% +through the rest of +it + + align:start position:0% +it + + + align:start position:0% +it +okay a really nice + + align:start position:0% +okay a really nice + + + align:start position:0% +okay a really nice +algorithm as I said an example of divide + + align:start position:0% +algorithm as I said an example of divide + + + align:start position:0% +algorithm as I said an example of divide +and conquer notice here that it's + + align:start position:0% +and conquer notice here that it's + + + align:start position:0% +and conquer notice here that it's +different than the binary search case + + align:start position:0% +different than the binary search case + + + align:start position:0% +different than the binary search case +we're certainly dividing down but the + + align:start position:0% +we're certainly dividing down but the + + + align:start position:0% +we're certainly dividing down but the +combination now actually takes some work + + align:start position:0% +combination now actually takes some work + + + align:start position:0% +combination now actually takes some work +right I have to actually figure out how + + align:start position:0% +right I have to actually figure out how + + + align:start position:0% +right I have to actually figure out how +to put them back together and that's a + + align:start position:0% +to put them back together and that's a + + + align:start position:0% +to put them back together and that's a +general thing you want to keep in mind + + align:start position:0% +general thing you want to keep in mind + + + align:start position:0% +general thing you want to keep in mind +when you're thinking about designing a + + align:start position:0% +when you're thinking about designing a + + + align:start position:0% +when you're thinking about designing a +divide and conquer kind of algorithm you + + align:start position:0% +divide and conquer kind of algorithm you + + + align:start position:0% +divide and conquer kind of algorithm you +really want to get the power of dividing + + align:start position:0% +really want to get the power of dividing + + + align:start position:0% +really want to get the power of dividing +things up but if you end up doing a ton + + align:start position:0% +things up but if you end up doing a ton + + + align:start position:0% +things up but if you end up doing a ton +of work at the combination stage you may + + align:start position:0% +of work at the combination stage you may + + + align:start position:0% +of work at the combination stage you may +not have gained anything so you really + + align:start position:0% +not have gained anything so you really + + + align:start position:0% +not have gained anything so you really +want to think that + + align:start position:0% +want to think that + + + align:start position:0% +want to think that +tradeoff all right having said that + + align:start position:0% +tradeoff all right having said that + + + align:start position:0% +tradeoff all right having said that +what's the complexity + + align:start position:0% + + + + align:start position:0% + +here well there's a dumb question + + align:start position:0% +here well there's a dumb question + + + align:start position:0% +here well there's a dumb question +because I've been telling you for the + + align:start position:0% +because I've been telling you for the + + + align:start position:0% +because I've been telling you for the +last two lectures the complexity is n + + align:start position:0% +last two lectures the complexity is n + + + align:start position:0% +last two lectures the complexity is n +log n but let's see if it really is + + align:start position:0% +log n but let's see if it really is + + + align:start position:0% +log n but let's see if it really is +what's the complexity + + align:start position:0% +what's the complexity + + + align:start position:0% +what's the complexity +here if we think about + + align:start position:0% + + + + align:start position:0% + +it we start off + + align:start position:0% + + + + align:start position:0% + +yeah with a problem of sizing + + align:start position:0% +yeah with a problem of sizing + + + align:start position:0% +yeah with a problem of sizing +n what do we do we split it into two + + align:start position:0% +n what do we do we split it into two + + + align:start position:0% +n what do we do we split it into two +problems of size + + align:start position:0% +problems of size + + + align:start position:0% +problems of size +n/2 those get split each into two + + align:start position:0% +n/2 those get split each into two + + + align:start position:0% +n/2 those get split each into two +problems of size n over4 and we keep + + align:start position:0% +problems of size n over4 and we keep + + + align:start position:0% +problems of size n over4 and we keep +doing that until we get down + + align:start position:0% + + + + align:start position:0% + +to a level in this tree where we have + + align:start position:0% +to a level in this tree where we have + + + align:start position:0% +to a level in this tree where we have +only Singleton left + + align:start position:0% +only Singleton left + + + align:start position:0% +only Singleton left +over okay once we're there we have to do + + align:start position:0% +over okay once we're there we have to do + + + align:start position:0% +over okay once we're there we have to do +the merge and notice what happens here + + align:start position:0% +the merge and notice what happens here + + + align:start position:0% +the merge and notice what happens here +we said each of the merge operations was + + align:start position:0% +we said each of the merge operations was + + + align:start position:0% +we said each of the merge operations was +of of of of order n but n is different + + align:start position:0% +of of of of order n but n is different + + + align:start position:0% +of of of of order n but n is different +right down here I've just got two things + + align:start position:0% +right down here I've just got two things + + + align:start position:0% +right down here I've just got two things +to merge and then I've got things of + + align:start position:0% +to merge and then I've got things of + + + align:start position:0% +to merge and then I've got things of +size two to merge and then things of + + align:start position:0% +size two to merge and then things of + + + align:start position:0% +size two to merge and then things of +size four to merge but notice the + + align:start position:0% +size four to merge but notice the + + + align:start position:0% +size four to merge but notice the +trade-off I have + + align:start position:0% +trade-off I have + + + align:start position:0% +trade-off I have +n operations if you like down there of + + align:start position:0% +n operations if you like down there of + + + align:start position:0% +n operations if you like down there of +size one up here I have n over two + + align:start position:0% +size one up here I have n over two + + + align:start position:0% +size one up here I have n over two +operations of size two up here I've got + + align:start position:0% +operations of size two up here I've got + + + align:start position:0% +operations of size two up here I've got +n over4 operations of size four so I + + align:start position:0% +n over4 operations of size four so I + + + align:start position:0% +n over4 operations of size four so I +always have to do a merge of n + + align:start position:0% +always have to do a merge of n + + + align:start position:0% +always have to do a merge of n +elements how much time does that + + align:start position:0% +elements how much time does that + + + align:start position:0% +elements how much time does that +take well we said it right + + align:start position:0% +take well we said it right + + + align:start position:0% +take well we said it right +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +oops where did I put it right there + + align:start position:0% +oops where did I put it right there + + + align:start position:0% +oops where did I put it right there +order n so I have order + + align:start position:0% +order n so I have order + + + align:start position:0% +order n so I have order +n + + align:start position:0% + + + + align:start position:0% + +operations at each level in the + + align:start position:0% + + + + align:start position:0% + +tree and then how many levels deep am I + + align:start position:0% +tree and then how many levels deep am I + + + align:start position:0% +tree and then how many levels deep am I +well that's the Divide right so how many + + align:start position:0% +well that's the Divide right so how many + + + align:start position:0% +well that's the Divide right so how many +levels do I + + align:start position:0% + + + + align:start position:0% + +have log M because at each stage I'm + + align:start position:0% +have log M because at each stage I'm + + + align:start position:0% +have log M because at each stage I'm +cutting the problem in half so I start + + align:start position:0% +cutting the problem in half so I start + + + align:start position:0% +cutting the problem in half so I start +off with n then it's n/2 n 4 n/8 so I + + align:start position:0% +off with n then it's n/2 n 4 n/8 so I + + + align:start position:0% +off with n then it's n/2 n 4 n/8 so I +got n so I have n operations log n times + + align:start position:0% +got n so I have n operations log n times + + + align:start position:0% +got n so I have n operations log n times +there we + + align:start position:0% +there we + + + align:start position:0% +there we +go and log + + align:start position:0% +go and log + + + align:start position:0% +go and log +in took us a long time to get there but + + align:start position:0% +in took us a long time to get there but + + + align:start position:0% +in took us a long time to get there but +it's a nice algorithm to + + align:start position:0% +it's a nice algorithm to + + + align:start position:0% +it's a nice algorithm to +have all right let me generalize this + + align:start position:0% +have all right let me generalize this + + + align:start position:0% +have all right let me generalize this +slightly + + align:start position:0% +slightly + + + align:start position:0% +slightly +okay when we get a problem a standard + + align:start position:0% +okay when we get a problem a standard + + + align:start position:0% +okay when we get a problem a standard +tool to try and attack it with is to say + + align:start position:0% +tool to try and attack it with is to say + + + align:start position:0% +tool to try and attack it with is to say +is there some way to break this problem + + align:start position:0% +is there some way to break this problem + + + align:start position:0% +is there some way to break this problem +problem down into simpler or shouldn't + + align:start position:0% +problem down into simpler or shouldn't + + + align:start position:0% +problem down into simpler or shouldn't +say simpler smaller versions of the same + + align:start position:0% +say simpler smaller versions of the same + + + align:start position:0% +say simpler smaller versions of the same +problem okay if I can do that it's a + + align:start position:0% +problem okay if I can do that it's a + + + align:start position:0% +problem okay if I can do that it's a +good candidate for divide and conquer + + align:start position:0% +good candidate for divide and conquer + + + align:start position:0% +good candidate for divide and conquer +and then the things I have to ask is how + + align:start position:0% +and then the things I have to ask is how + + + align:start position:0% +and then the things I have to ask is how +much of a division do I want to do the + + align:start position:0% +much of a division do I want to do the + + + align:start position:0% +much of a division do I want to do the +obvious ones to divide it in half but + + align:start position:0% +obvious ones to divide it in half but + + + align:start position:0% +obvious ones to divide it in half but +there may be cases where there are + + align:start position:0% +there may be cases where there are + + + align:start position:0% +there may be cases where there are +different divisions you want to have + + align:start position:0% +different divisions you want to have + + + align:start position:0% +different divisions you want to have +take place the second question I want to + + align:start position:0% +take place the second question I want to + + + align:start position:0% +take place the second question I want to +ask is what's the base case when do I + + align:start position:0% +ask is what's the base case when do I + + + align:start position:0% +ask is what's the base case when do I +get down to a problem small enough that + + align:start position:0% +get down to a problem small enough that + + + align:start position:0% +get down to a problem small enough that +it's basically trivial to solve here it + + align:start position:0% +it's basically trivial to solve here it + + + align:start position:0% +it's basically trivial to solve here it +was list of size one I put have stopped + + align:start position:0% +was list of size one I put have stopped + + + align:start position:0% +was list of size one I put have stopped +at list a size two right that's an easy + + align:start position:0% +at list a size two right that's an easy + + + align:start position:0% +at list a size two right that's an easy +comparison do one comparison and return + + align:start position:0% +comparison do one comparison and return + + + align:start position:0% +comparison do one comparison and return +one of two possible orders on it but I + + align:start position:0% +one of two possible orders on it but I + + + align:start position:0% +one of two possible orders on it but I +need you to decide that the third thing + + align:start position:0% +need you to decide that the third thing + + + align:start position:0% +need you to decide that the third thing +I need to decide is how do I combine + + align:start position:0% +I need to decide is how do I combine + + + align:start position:0% +I need to decide is how do I combine +okay and I'll point out to you in the + + align:start position:0% +okay and I'll point out to you in the + + + align:start position:0% +okay and I'll point out to you in the +binary search case combination was + + align:start position:0% +binary search case combination was + + + align:start position:0% +binary search case combination was +trivial right answer to the final search + + align:start position:0% +trivial right answer to the final search + + + align:start position:0% +trivial right answer to the final search +was just the answer all the way up here + + align:start position:0% +was just the answer all the way up here + + + align:start position:0% +was just the answer all the way up here +little more work and that's why I'll + + align:start position:0% +little more work and that's why I'll + + + align:start position:0% +little more work and that's why I'll +come back to that idea if it if I'm + + align:start position:0% +come back to that idea if it if I'm + + + align:start position:0% +come back to that idea if it if I'm +basically just squeezing Jello that is + + align:start position:0% +basically just squeezing Jello that is + + + align:start position:0% +basically just squeezing Jello that is +I'm trying to make the problem simpler + + align:start position:0% +I'm trying to make the problem simpler + + + align:start position:0% +I'm trying to make the problem simpler +but the combination turns out to be + + align:start position:0% +but the combination turns out to be + + + align:start position:0% +but the combination turns out to be +really complex I've not gained anything + + align:start position:0% +really complex I've not gained anything + + + align:start position:0% +really complex I've not gained anything +so things that are good candidates for + + align:start position:0% +so things that are good candidates for + + + align:start position:0% +so things that are good candidates for +divide and conquer are problems where + + align:start position:0% +divide and conquer are problems where + + + align:start position:0% +divide and conquer are problems where +it's easy to figure out how to divide + + align:start position:0% +it's easy to figure out how to divide + + + align:start position:0% +it's easy to figure out how to divide +down and the combination is of low + + align:start position:0% +down and the combination is of low + + + align:start position:0% +down and the combination is of low +complexity be nice if it was less than + + align:start position:0% +complexity be nice if it was less than + + + align:start position:0% +complexity be nice if it was less than +linear but linear is nice because then + + align:start position:0% +linear but linear is nice because then + + + align:start position:0% +linear but linear is nice because then +I'm going to get that n log in kind of + + align:start position:0% +I'm going to get that n log in kind of + + + align:start position:0% +I'm going to get that n log in kind of +behavior and if you ask the Tas in + + align:start position:0% +behavior and if you ask the Tas in + + + align:start position:0% +behavior and if you ask the Tas in +recitation tomorrow they'll tell you + + align:start position:0% +recitation tomorrow they'll tell you + + + align:start position:0% +recitation tomorrow they'll tell you +that you see a lot of nlog and + + align:start position:0% +that you see a lot of nlog and + + + align:start position:0% +that you see a lot of nlog and +algorithms in computer science it's a + + align:start position:0% +algorithms in computer science it's a + + + align:start position:0% +algorithms in computer science it's a +very common class of algorithm and it's + + align:start position:0% +very common class of algorithm and it's + + + align:start position:0% +very common class of algorithm and it's +a very useful one to + + align:start position:0% +a very useful one to + + + align:start position:0% +a very useful one to +have + + align:start position:0% +have + + + align:start position:0% +have +okay now + + align:start position:0% +okay now + + + align:start position:0% +okay now +one of the questions we could still ask + + align:start position:0% +one of the questions we could still ask + + + align:start position:0% +one of the questions we could still ask +is right we got binary search which has + + align:start position:0% +is right we got binary search which has + + + align:start position:0% +is right we got binary search which has +got this nice log + + align:start position:0% +got this nice log + + + align:start position:0% +got this nice log +Behavior if we can sort things um you + + align:start position:0% +Behavior if we can sort things um you + + + align:start position:0% +Behavior if we can sort things um you +know we get this this n log n behavior + + align:start position:0% +know we get this this n log n behavior + + + align:start position:0% +know we get this this n log n behavior +and we got an N log n Behavior overall + + align:start position:0% +and we got an N log n Behavior overall + + + align:start position:0% +and we got an N log n Behavior overall +but can we actually do better in terms + + align:start position:0% +but can we actually do better in terms + + + align:start position:0% +but can we actually do better in terms +of searching and I'm going to show you + + align:start position:0% +of searching and I'm going to show you + + + align:start position:0% +of searching and I'm going to show you +one last technique that in fact I'm + + align:start position:0% +one last technique that in fact I'm + + + align:start position:0% +one last technique that in fact I'm +going a weir put quotes around the word + + align:start position:0% +going a weir put quotes around the word + + + align:start position:0% +going a weir put quotes around the word +better but it does better than uh even + + align:start position:0% +better but it does better than uh even + + + align:start position:0% +better but it does better than uh even +this kind of binary search + + align:start position:0% +this kind of binary search + + + align:start position:0% +this kind of binary search +that's a method called + + align:start position:0% + + + + align:start position:0% + +hashing + + align:start position:0% +hashing + + + align:start position:0% +hashing +okay you've actually seen hashing you + + align:start position:0% +okay you've actually seen hashing you + + + align:start position:0% +okay you've actually seen hashing you +just don't know it hashing is the + + align:start position:0% +just don't know it hashing is the + + + align:start position:0% +just don't know it hashing is the +technique that's used in Python to + + align:start position:0% +technique that's used in Python to + + + align:start position:0% +technique that's used in Python to +represent + + align:start position:0% +represent + + + align:start position:0% +represent +dictionaries hashing is used when you + + align:start position:0% +dictionaries hashing is used when you + + + align:start position:0% +dictionaries hashing is used when you +actually come into Logan airport and + + align:start position:0% +actually come into Logan airport and + + + align:start position:0% +actually come into Logan airport and +immigration or Homeland Security checks + + align:start position:0% +immigration or Homeland Security checks + + + align:start position:0% +immigration or Homeland Security checks +your picture against a database um + + align:start position:0% +your picture against a database um + + + align:start position:0% +your picture against a database um +hashing is used every time you enter a + + align:start position:0% +hashing is used every time you enter a + + + align:start position:0% +hashing is used every time you enter a +password into a system so what in the + + align:start position:0% +password into a system so what in the + + + align:start position:0% +password into a system so what in the +world is hashing well let me start with + + align:start position:0% +world is hashing well let me start with + + + align:start position:0% +world is hashing well let me start with +a simple little example + + align:start position:0% +a simple little example + + + align:start position:0% +a simple little example +suppose I want to + + align:start position:0% +suppose I want to + + + align:start position:0% +suppose I want to +represent a + + align:start position:0% +represent a + + + align:start position:0% +represent a +collection of integers this is a really + + align:start position:0% +collection of integers this is a really + + + align:start position:0% +collection of integers this is a really +easy little + + align:start position:0% +easy little + + + align:start position:0% +easy little +example and I promise you that the + + align:start position:0% +example and I promise you that the + + + align:start position:0% +example and I promise you that the +integers are never going to be anything + + align:start position:0% +integers are never going to be anything + + + align:start position:0% +integers are never going to be anything +other than between the range of 0 to + + align:start position:0% +other than between the range of 0 to + + + align:start position:0% +other than between the range of 0 to +nine okay so it might be the collection + + align:start position:0% +nine okay so it might be the collection + + + align:start position:0% +nine okay so it might be the collection +one and five it might be 2 3 48 I mean + + align:start position:0% +one and five it might be 2 3 48 I mean + + + align:start position:0% +one and five it might be 2 3 48 I mean +some collection of integers but I + + align:start position:0% +some collection of integers but I + + + align:start position:0% +some collection of integers but I +guarantee you it's between zero and nine + + align:start position:0% +guarantee you it's between zero and nine + + + align:start position:0% +guarantee you it's between zero and nine +here's the trick I can + + align:start position:0% +here's the trick I can + + + align:start position:0% +here's the trick I can +play I can build + + align:start position:0% + + + + align:start position:0% + +I can't + + align:start position:0% + + + + align:start position:0% + +count I could build a + + align:start position:0% +count I could build a + + + align:start position:0% +count I could build a +list with spots for all of those + + align:start position:0% +list with spots for all of those + + + align:start position:0% +list with spots for all of those +elements 0 1 2 3 4 5 6 78 n and then + + align:start position:0% +elements 0 1 2 3 4 5 6 78 n and then + + + align:start position:0% +elements 0 1 2 3 4 5 6 78 n and then +when I want to create my set I could + + align:start position:0% +when I want to create my set I could + + + align:start position:0% +when I want to create my set I could +simply put a + + align:start position:0% +simply put a + + + align:start position:0% +simply put a +one + + align:start position:0% +one + + + align:start position:0% +one +everywhere that that integer Falls so if + + align:start position:0% +everywhere that that integer Falls so if + + + align:start position:0% +everywhere that that integer Falls so if +I wanted to represent that for example + + align:start position:0% +I wanted to represent that for example + + + align:start position:0% +I wanted to represent that for example +this is the set + + align:start position:0% +this is the set + + + align:start position:0% +this is the set +two six and eight I put a one in those + + align:start position:0% +two six and eight I put a one in those + + + align:start position:0% +two six and eight I put a one in those +slots right this seems a little weird + + align:start position:0% +slots right this seems a little weird + + + align:start position:0% +slots right this seems a little weird +but the bear with me for a second in + + align:start position:0% +but the bear with me for a second in + + + align:start position:0% +but the bear with me for a second in +fact I've given you a little piece of + + align:start position:0% +fact I've given you a little piece of + + + align:start position:0% +fact I've given you a little piece of +code to do + + align:start position:0% +code to do + + + align:start position:0% +code to do +it which is the next piece of code on + + align:start position:0% +it which is the next piece of code on + + + align:start position:0% +it which is the next piece of code on +the on the + + align:start position:0% +the on the + + + align:start position:0% +the on the +handout so let's take a look at it for a + + align:start position:0% +handout so let's take a look at it for a + + + align:start position:0% +handout so let's take a look at it for a +second right this little set of code + + align:start position:0% +second right this little set of code + + + align:start position:0% +second right this little set of code +here from create insert and member + + align:start position:0% +here from create insert and member + + + align:start position:0% +here from create insert and member +what's create do it says given a low and + + align:start position:0% +what's create do it says given a low and + + + align:start position:0% +what's create do it says given a low and +a high range in this case it' be zero to + + align:start position:0% +a high range in this case it' be zero to + + + align:start position:0% +a high range in this case it' be zero to +n9ine I'm going to build + + align:start position:0% +n9ine I'm going to build + + + align:start position:0% +n9ine I'm going to build +ah a list right you can see that little + + align:start position:0% +ah a list right you can see that little + + + align:start position:0% +ah a list right you can see that little +Loop through going through there what am + + align:start position:0% +Loop through going through there what am + + + align:start position:0% +Loop through going through there what am +I doing I'm creating a list with just + + align:start position:0% +I doing I'm creating a list with just + + + align:start position:0% +I doing I'm creating a list with just +that special symbol none in it so I'm + + align:start position:0% +that special symbol none in it so I'm + + + align:start position:0% +that special symbol none in it so I'm +building the list I'm returning that as + + align:start position:0% +building the list I'm returning that as + + + align:start position:0% +building the list I'm returning that as +my set and then to create the object + + align:start position:0% +my set and then to create the object + + + align:start position:0% +my set and then to create the object +I'll simply do a set of inserts if I + + align:start position:0% +I'll simply do a set of inserts if I + + + align:start position:0% +I'll simply do a set of inserts if I +want the values 2 six and eight in there + + align:start position:0% +want the values 2 six and eight in there + + + align:start position:0% +want the values 2 six and eight in there +I would do an insert of two into that + + align:start position:0% +I would do an insert of two into that + + + align:start position:0% +I would do an insert of two into that +set an insert of six into that set and + + align:start position:0% +set an insert of six into that set and + + + align:start position:0% +set an insert of six into that set and +an insert of eight into that set and + + align:start position:0% +an insert of eight into that set and + + + align:start position:0% +an insert of eight into that set and +what does it do it marks a one in each + + align:start position:0% +what does it do it marks a one in each + + + align:start position:0% +what does it do it marks a one in each +of those + + align:start position:0% +of those + + + align:start position:0% +of those +spots now what did I want to do I wanted + + align:start position:0% +spots now what did I want to do I wanted + + + align:start position:0% +spots now what did I want to do I wanted +to check membership I want to do search + + align:start position:0% +to check membership I want to do search + + + align:start position:0% +to check membership I want to do search +well that's simple given that + + align:start position:0% +well that's simple given that + + + align:start position:0% +well that's simple given that +representation and some value I just say + + align:start position:0% +representation and some value I just say + + + align:start position:0% +representation and some value I just say +G is it + + align:start position:0% +G is it + + + align:start position:0% +G is it +there what's the order of complexity + + align:start position:0% + + + + align:start position:0% + +here I know I drive you not asking + + align:start position:0% +here I know I drive you not asking + + + align:start position:0% +here I know I drive you not asking +questions what's the order of complexity + + align:start position:0% +questions what's the order of complexity + + + align:start position:0% +questions what's the order of complexity +here + + align:start position:0% +here + + + align:start position:0% +here +quadratic + + align:start position:0% +quadratic + + + align:start position:0% +quadratic +linear + + align:start position:0% +linear + + + align:start position:0% +linear +log + + align:start position:0% + + + + align:start position:0% + +constant any taker I know I have the + + align:start position:0% +constant any taker I know I have the + + + align:start position:0% +constant any taker I know I have the +wrong glasses on to see hands up too but + + align:start position:0% + + + + align:start position:0% + +uh who said it constant + + align:start position:0% +uh who said it constant + + + align:start position:0% +uh who said it constant +why yeah thank you all right it is + + align:start position:0% +why yeah thank you all right it is + + + align:start position:0% +why yeah thank you all right it is +constant you keep sitting back there + + align:start position:0% +constant you keep sitting back there + + + align:start position:0% +constant you keep sitting back there +where I can't get to you thank you very + + align:start position:0% +where I can't get to you thank you very + + + align:start position:0% +where I can't get to you thank you very +much why is it constant remember we said + + align:start position:0% +much why is it constant remember we said + + + align:start position:0% +much why is it constant remember we said +we designed lists so that the access no + + align:start position:0% +we designed lists so that the access no + + + align:start position:0% +we designed lists so that the access no +matter where it was in the list was of + + align:start position:0% +matter where it was in the list was of + + + align:start position:0% +matter where it was in the list was of +constant time that is another way of + + align:start position:0% +constant time that is another way of + + + align:start position:0% +constant time that is another way of +saying that looking up this thing here + + align:start position:0% +saying that looking up this thing here + + + align:start position:0% +saying that looking up this thing here +is constant so this is constant time + + align:start position:0% +is constant so this is constant time + + + align:start position:0% +is constant so this is constant time +order + + align:start position:0% + + + + align:start position:0% + +one okay come on you know representing + + align:start position:0% +one okay come on you know representing + + + align:start position:0% +one okay come on you know representing +sets of integers this is pretty dumb + + align:start position:0% +sets of integers this is pretty dumb + + + align:start position:0% +sets of integers this is pretty dumb +suppose I want to have a set of + + align:start position:0% +suppose I want to have a set of + + + align:start position:0% +suppose I want to have a set of +characters how could I do that well the + + align:start position:0% +characters how could I do that well the + + + align:start position:0% +characters how could I do that well the +idea of a hash what's called a hash + + align:start position:0% +idea of a hash what's called a hash + + + align:start position:0% +idea of a hash what's called a hash +function is to have some way of mapping + + align:start position:0% +function is to have some way of mapping + + + align:start position:0% +function is to have some way of mapping +any kind of data into integers so let's + + align:start position:0% +any kind of data into integers so let's + + + align:start position:0% +any kind of data into integers so let's +look at the second + + align:start position:0% +look at the second + + + align:start position:0% +look at the second +example all right ah I keep doing + + align:start position:0% +example all right ah I keep doing + + + align:start position:0% +example all right ah I keep doing +that this piece of code + + align:start position:0% +that this piece of code + + + align:start position:0% +that this piece of code +from here to here gives me a way of now + + align:start position:0% +from here to here gives me a way of now + + + align:start position:0% +from here to here gives me a way of now +creating a hash table of size + + align:start position:0% +creating a hash table of size + + + align:start position:0% +creating a hash table of size +256 O is a built-in python + + align:start position:0% +256 O is a built-in python + + + align:start position:0% +256 O is a built-in python +representation there's lots of them + + align:start position:0% +representation there's lots of them + + + align:start position:0% +representation there's lots of them +around that takes any character and + + align:start position:0% +around that takes any character and + + + align:start position:0% +around that takes any character and +gives you back an integer in fact just + + align:start position:0% +gives you back an integer in fact just + + + align:start position:0% +gives you back an integer in fact just +to show that to you if I go down here + + align:start position:0% +to show that to you if I go down here + + + align:start position:0% +to show that to you if I go down here +and I type + + align:start position:0% +and I type + + + align:start position:0% +and I type +O ah + + align:start position:0% + + + + align:start position:0% + +sorry I did that wrong let me try again + + align:start position:0% +sorry I did that wrong let me try again + + + align:start position:0% +sorry I did that wrong let me try again +we'll get to exceptions in a + + align:start position:0% + + + + align:start position:0% + +second I give it some character it gives + + align:start position:0% +second I give it some character it gives + + + align:start position:0% +second I give it some character it gives +me back an integer representing and it + + align:start position:0% +me back an integer representing and it + + + align:start position:0% +me back an integer representing and it +looks weird why is three come back to + + align:start position:0% +looks weird why is three come back to + + + align:start position:0% +looks weird why is three come back to +some other thing that's the internal + + align:start position:0% +some other thing that's the internal + + + align:start position:0% +some other thing that's the internal +representation that python uses for this + + align:start position:0% +representation that python uses for this + + + align:start position:0% +representation that python uses for this +if I give it some other + + align:start position:0% +if I give it some other + + + align:start position:0% +if I give it some other +character now it would help if I could + + align:start position:0% +character now it would help if I could + + + align:start position:0% +character now it would help if I could +type and give it some other character + + align:start position:0% +type and give it some other character + + + align:start position:0% +type and give it some other character +gives me back a + + align:start position:0% +gives me back a + + + align:start position:0% +gives me back a +representation so now here's the idea I + + align:start position:0% +representation so now here's the idea I + + + align:start position:0% +representation so now here's the idea I +build a list 256 elements long right and + + align:start position:0% +build a list 256 elements long right and + + + align:start position:0% +build a list 256 elements long right and +I fill it up with those special + + align:start position:0% +I fill it up with those special + + + align:start position:0% +I fill it up with those special +characters none that's what create is + + align:start position:0% +characters none that's what create is + + + align:start position:0% +characters none that's what create is +going to do right here and then hash + + align:start position:0% +going to do right here and then hash + + + align:start position:0% +going to do right here and then hash +character takes in any string or + + align:start position:0% +character takes in any string or + + + align:start position:0% +character takes in any string or +character Single Character gives me back + + align:start position:0% +character Single Character gives me back + + + align:start position:0% +character Single Character gives me back +a number and notice what I do if I want + + align:start position:0% +a number and notice what I do if I want + + + align:start position:0% +a number and notice what I do if I want +to create a set or a sequence + + align:start position:0% +to create a set or a sequence + + + align:start position:0% +to create a set or a sequence +representing these things I simply + + align:start position:0% +representing these things I simply + + + align:start position:0% +representing these things I simply +insert into that list that goes through + + align:start position:0% +insert into that list that goes through + + + align:start position:0% +insert into that list that goes through +and puts ones in the right place and + + align:start position:0% +and puts ones in the right place and + + + align:start position:0% +and puts ones in the right place and +then if I want to find out if a + + align:start position:0% +then if I want to find out if a + + + align:start position:0% +then if I want to find out if a +something's there I do the same thing + + align:start position:0% +something's there I do the same thing + + + align:start position:0% +something's there I do the same thing +but notice now hash is converting the + + align:start position:0% +but notice now hash is converting the + + + align:start position:0% +but notice now hash is converting the +input into an + + align:start position:0% +input into an + + + align:start position:0% +input into an +integer + + align:start position:0% +integer + + + align:start position:0% +integer +okay so what's the idea if I know what + + align:start position:0% +okay so what's the idea if I know what + + + align:start position:0% +okay so what's the idea if I know what +my hash function does it maps in this + + align:start position:0% +my hash function does it maps in this + + + align:start position:0% +my hash function does it maps in this +case characters into a range 0 to 256 0 + + align:start position:0% +case characters into a range 0 to 256 0 + + + align:start position:0% +case characters into a range 0 to 256 0 +to 255 I create a list that long and I + + align:start position:0% +to 255 I create a list that long and I + + + align:start position:0% +to 255 I create a list that long and I +simply Mark things and my lookup is + + align:start position:0% +simply Mark things and my lookup is + + + align:start position:0% +simply Mark things and my lookup is +still + + align:start position:0% +still + + + align:start position:0% +still +constant all right characters are simple + + align:start position:0% +constant all right characters are simple + + + align:start position:0% +constant all right characters are simple +suppose you want to represent sets of + + align:start position:0% +suppose you want to represent sets of + + + align:start position:0% +suppose you want to represent sets of +strings + + align:start position:0% +strings + + + align:start position:0% +strings +well you basically just generalize the + + align:start position:0% +well you basically just generalize the + + + align:start position:0% +well you basically just generalize the +hash function I think one of the classic + + align:start position:0% +hash function I think one of the classic + + + align:start position:0% +hash function I think one of the classic +ones for Strings is called The Raven + + align:start position:0% +ones for Strings is called The Raven + + + align:start position:0% +ones for Strings is called The Raven +carp algorithm and it's simply the same + + align:start position:0% +carp algorithm and it's simply the same + + + align:start position:0% +carp algorithm and it's simply the same +idea that you have a mapping from your + + align:start position:0% +idea that you have a mapping from your + + + align:start position:0% +idea that you have a mapping from your +input into a set of + + align:start position:0% +input into a set of + + + align:start position:0% +input into a set of +integers wow okay maybe not so well but + + align:start position:0% +integers wow okay maybe not so well but + + + align:start position:0% +integers wow okay maybe not so well but +this is now constant right this is + + align:start position:0% +this is now constant right this is + + + align:start position:0% +this is now constant right this is +constant time access so I can do + + align:start position:0% +constant time access so I can do + + + align:start position:0% +constant time access so I can do +searching in constant time which is + + align:start position:0% +searching in constant time which is + + + align:start position:0% +searching in constant time which is +great where's the + + align:start position:0% +great where's the + + + align:start position:0% +great where's the +penalty what did I trade off here + + align:start position:0% +penalty what did I trade off here + + + align:start position:0% +penalty what did I trade off here +well I'm going to suggest that what I + + align:start position:0% +well I'm going to suggest that what I + + + align:start position:0% +well I'm going to suggest that what I +did was I really + + align:start position:0% + + + + align:start position:0% + +traded + + align:start position:0% + + + + align:start position:0% + +space per + + align:start position:0% + + + + align:start position:0% + +time makes me sound like an + + align:start position:0% +time makes me sound like an + + + align:start position:0% +time makes me sound like an +astrophysicist somehow right what do I + + align:start position:0% +astrophysicist somehow right what do I + + + align:start position:0% +astrophysicist somehow right what do I +mean by that I have constant time access + + align:start position:0% +mean by that I have constant time access + + + align:start position:0% +mean by that I have constant time access +which is great but I paid a price which + + align:start position:0% +which is great but I paid a price which + + + align:start position:0% +which is great but I paid a price which +is I had to use up some space in the + + align:start position:0% +is I had to use up some space in the + + + align:start position:0% +is I had to use up some space in the +case of integers it was easy in the case + + align:start position:0% +case of integers it was easy in the case + + + align:start position:0% +case of integers it was easy in the case +of characters so I have to give up a + + align:start position:0% +of characters so I have to give up a + + + align:start position:0% +of characters so I have to give up a +list of 256 no no big deal imagine now + + align:start position:0% +list of 256 no no big deal imagine now + + + align:start position:0% +list of 256 no no big deal imagine now +you want to do faces right you got a + + align:start position:0% +you want to do faces right you got a + + + align:start position:0% +you want to do faces right you got a +picture of somebody's face it's a + + align:start position:0% +picture of somebody's face it's a + + + align:start position:0% +picture of somebody's face it's a +million pixels each pixel has a range of + + align:start position:0% +million pixels each pixel has a range of + + + align:start position:0% +million pixels each pixel has a range of +values from zero to 256 I want to Hash a + + align:start position:0% +values from zero to 256 I want to Hash a + + + align:start position:0% +values from zero to 256 I want to Hash a +face with some function into an integer + + align:start position:0% +face with some function into an integer + + + align:start position:0% +face with some function into an integer +okay I may not want to do the full range + + align:start position:0% +okay I may not want to do the full range + + + align:start position:0% +okay I may not want to do the full range +of this but I may decide I have to use a + + align:start position:0% +of this but I may decide I have to use a + + + align:start position:0% +of this but I may decide I have to use a +lot of gigabytes of space in order to do + + align:start position:0% +lot of gigabytes of space in order to do + + + align:start position:0% +lot of gigabytes of space in order to do +the trade-off the reason I'm showing you + + align:start position:0% +the trade-off the reason I'm showing you + + + align:start position:0% +the trade-off the reason I'm showing you +this is that this is again a common + + align:start position:0% +this is that this is again a common + + + align:start position:0% +this is that this is again a common +trade-off in computer science that in + + align:start position:0% +trade-off in computer science that in + + + align:start position:0% +trade-off in computer science that in +many cases I can gain efficiency if I'm + + align:start position:0% +many cases I can gain efficiency if I'm + + + align:start position:0% +many cases I can gain efficiency if I'm +willing to give up space + + align:start position:0% +willing to give up space + + + align:start position:0% +willing to give up space +having said that though there may still + + align:start position:0% +having said that though there may still + + + align:start position:0% +having said that though there may still +be a problem or there ought to be a + + align:start position:0% +be a problem or there ought to be a + + + align:start position:0% +be a problem or there ought to be a +problem that may be bugging you slightly + + align:start position:0% +problem that may be bugging you slightly + + + align:start position:0% +problem that may be bugging you slightly +which is how do I + + align:start position:0% +which is how do I + + + align:start position:0% +which is how do I +guarantee that my hash function takes + + align:start position:0% +guarantee that my hash function takes + + + align:start position:0% +guarantee that my hash function takes +any input into exactly one spot in the + + align:start position:0% +any input into exactly one spot in the + + + align:start position:0% +any input into exactly one spot in the +storage + + align:start position:0% +storage + + + align:start position:0% +storage +space the answer is I can't okay in the + + align:start position:0% +space the answer is I can't okay in the + + + align:start position:0% +space the answer is I can't okay in the +simple case of integers I can't but in + + align:start position:0% +simple case of integers I can't but in + + + align:start position:0% +simple case of integers I can't but in +the case of something more complex like + + align:start position:0% +the case of something more complex like + + + align:start position:0% +the case of something more complex like +faces or fingerprints or passwords for + + align:start position:0% +faces or fingerprints or passwords for + + + align:start position:0% +faces or fingerprints or passwords for +that matter it's hard to design a hash + + align:start position:0% +that matter it's hard to design a hash + + + align:start position:0% +that matter it's hard to design a hash +function that has completely even + + align:start position:0% +function that has completely even + + + align:start position:0% +function that has completely even +distribution meaning that it takes any + + align:start position:0% +distribution meaning that it takes any + + + align:start position:0% +distribution meaning that it takes any +input into exactly one output spot so + + align:start position:0% +input into exactly one output spot so + + + align:start position:0% +input into exactly one output spot so +what you typically do in a hash case is + + align:start position:0% +what you typically do in a hash case is + + + align:start position:0% +what you typically do in a hash case is +you design your code to deal with that + + align:start position:0% +you design your code to deal with that + + + align:start position:0% +you design your code to deal with that +you try and design actually I'm going to + + align:start position:0% +you try and design actually I'm going to + + + align:start position:0% +you try and design actually I'm going to +come back to that in a second you try + + align:start position:0% +come back to that in a second you try + + + align:start position:0% +come back to that in a second you try +and use a hash function that spreads + + align:start position:0% +and use a hash function that spreads + + + align:start position:0% +and use a hash function that spreads +things out pretty evenly but the places + + align:start position:0% +things out pretty evenly but the places + + + align:start position:0% +things out pretty evenly but the places +you store into and those lists may have + + align:start position:0% +you store into and those lists may have + + + align:start position:0% +you store into and those lists may have +to themselves have a small list in there + + align:start position:0% +to themselves have a small list in there + + + align:start position:0% +to themselves have a small list in there +and when you go to check something you + + align:start position:0% +and when you go to check something you + + + align:start position:0% +and when you go to check something you +may have to do a linear search through + + align:start position:0% +may have to do a linear search through + + + align:start position:0% +may have to do a linear search through +the elements in that list the good news + + align:start position:0% +the elements in that list the good news + + + align:start position:0% +the elements in that list the good news +is the elements in any one spot in the + + align:start position:0% +is the elements in any one spot in the + + + align:start position:0% +is the elements in any one spot in the +hash table are likely to be a small + + align:start position:0% +hash table are likely to be a small + + + align:start position:0% +hash table are likely to be a small +number 3 four five so the search is + + align:start position:0% +number 3 four five so the search is + + + align:start position:0% +number 3 four five so the search is +really easy you're not Sear searching a + + align:start position:0% +really easy you're not Sear searching a + + + align:start position:0% +really easy you're not Sear searching a +million things you're searching three or + + align:start position:0% +million things you're searching three or + + + align:start position:0% +million things you're searching three or +four things but nonetheless you have to + + align:start position:0% +four things but nonetheless you have to + + + align:start position:0% +four things but nonetheless you have to +do that + + align:start position:0% +do that + + + align:start position:0% +do that +tradeoff the last thing I want to say + + align:start position:0% +tradeoff the last thing I want to say + + + align:start position:0% +tradeoff the last thing I want to say +about hashes + + align:start position:0% + + + + align:start position:0% + +are that they're actually really hard to + + align:start position:0% +are that they're actually really hard to + + + align:start position:0% +are that they're actually really hard to +create there's been a lot of work done + + align:start position:0% +create there's been a lot of work done + + + align:start position:0% +create there's been a lot of work done +in these over the years but in fact it's + + align:start position:0% +in these over the years but in fact it's + + + align:start position:0% +in these over the years but in fact it's +pretty hard to invent a good hash + + align:start position:0% +pretty hard to invent a good hash + + + align:start position:0% +pretty hard to invent a good hash +function so my advice to you is if you + + align:start position:0% +function so my advice to you is if you + + + align:start position:0% +function so my advice to you is if you +want to use something with a hash go to + + align:start position:0% +want to use something with a hash go to + + + align:start position:0% +want to use something with a hash go to +a library look up a good hash function + + align:start position:0% +a library look up a good hash function + + + align:start position:0% +a library look up a good hash function +okay for Strings there's a classic set + + align:start position:0% +okay for Strings there's a classic set + + + align:start position:0% +okay for Strings there's a classic set +of them that work pretty well for + + align:start position:0% +of them that work pretty well for + + + align:start position:0% +of them that work pretty well for +integers there's some real simple ones + + align:start position:0% +integers there's some real simple ones + + + align:start position:0% +integers there's some real simple ones +if there's something more complex find a + + align:start position:0% +if there's something more complex find a + + + align:start position:0% +if there's something more complex find a +good hash function but designing a + + align:start position:0% +good hash function but designing a + + + align:start position:0% +good hash function but designing a +really good hash function takes a lot of + + align:start position:0% +really good hash function takes a lot of + + + align:start position:0% +really good hash function takes a lot of +effort because you want it to have that + + align:start position:0% +effort because you want it to have that + + + align:start position:0% +effort because you want it to have that +even distribution you'd like it to have + + align:start position:0% +even distribution you'd like it to have + + + align:start position:0% +even distribution you'd like it to have +as few duplicates if you like in each + + align:start position:0% +as few duplicates if you like in each + + + align:start position:0% +as few duplicates if you like in each +spot in the hash table for each one of + + align:start position:0% +spot in the hash table for each one of + + + align:start position:0% +spot in the hash table for each one of +the things that you + + align:start position:0% +the things that you + + + align:start position:0% +the things that you +use okay let me pull back for a second + + align:start position:0% +use okay let me pull back for a second + + + align:start position:0% +use okay let me pull back for a second +then what have we done over the last + + align:start position:0% +then what have we done over the last + + + align:start position:0% +then what have we done over the last +three or four lectures + + align:start position:0% +three or four lectures + + + align:start position:0% +three or four lectures +we've started introducing you to classes + + align:start position:0% +we've started introducing you to classes + + + align:start position:0% +we've started introducing you to classes +of algorithms things that I'd like you + + align:start position:0% +of algorithms things that I'd like you + + + align:start position:0% +of algorithms things that I'd like you +to be able to see are how to do some + + align:start position:0% +to be able to see are how to do some + + + align:start position:0% +to be able to see are how to do some +simple complexity analysis perhaps more + + align:start position:0% +simple complexity analysis perhaps more + + + align:start position:0% +simple complexity analysis perhaps more +importantly how to recognize a kind of + + align:start position:0% +importantly how to recognize a kind of + + + align:start position:0% +importantly how to recognize a kind of +algorithm based on its properties and + + align:start position:0% +algorithm based on its properties and + + + align:start position:0% +algorithm based on its properties and +know what class it belongs to this is a + + align:start position:0% +know what class it belongs to this is a + + + align:start position:0% +know what class it belongs to this is a +hint if you like leading towards the + + align:start position:0% +hint if you like leading towards the + + + align:start position:0% +hint if you like leading towards the +next Quiz that you ought to be able to + + align:start position:0% +next Quiz that you ought to be able to + + + align:start position:0% +next Quiz that you ought to be able to +say that looks like a logarithmic + + align:start position:0% +say that looks like a logarithmic + + + align:start position:0% +say that looks like a logarithmic +algorithm because it's got a particular + + align:start position:0% +algorithm because it's got a particular + + + align:start position:0% +algorithm because it's got a particular +property that looks like an N log n + + align:start position:0% +property that looks like an N log n + + + align:start position:0% +property that looks like an N log n +algorithm because it has a particular + + align:start position:0% +algorithm because it has a particular + + + align:start position:0% +algorithm because it has a particular +property and the third thing we've done + + align:start position:0% +property and the third thing we've done + + + align:start position:0% +property and the third thing we've done +is we've given you now a set set of sort + + align:start position:0% +is we've given you now a set set of sort + + + align:start position:0% +is we've given you now a set set of sort +of standard algorithms if you like Brute + + align:start position:0% +of standard algorithms if you like Brute + + + align:start position:0% +of standard algorithms if you like Brute +Force just walk through every possible + + align:start position:0% +Force just walk through every possible + + + align:start position:0% +Force just walk through every possible +case right works well if problem sizes + + align:start position:0% +case right works well if problem sizes + + + align:start position:0% +case right works well if problem sizes +are small we've had a number of variants + + align:start position:0% +are small we've had a number of variants + + + align:start position:0% +are small we've had a number of variants +of guess and check or hypothesize and + + align:start position:0% +of guess and check or hypothesize and + + + align:start position:0% +of guess and check or hypothesize and +test where you try and guess the + + align:start position:0% +test where you try and guess the + + + align:start position:0% +test where you try and guess the +solution and then check it and use that + + align:start position:0% +solution and then check it and use that + + + align:start position:0% +solution and then check it and use that +to refine your search success of + + align:start position:0% +to refine your search success of + + + align:start position:0% +to refine your search success of +approximation Newton rafson was one nice + + align:start position:0% +approximation Newton rafson was one nice + + + align:start position:0% +approximation Newton rafson was one nice +example but there's a whole class of + + align:start position:0% +example but there's a whole class of + + + align:start position:0% +example but there's a whole class of +things that get closer and closer + + align:start position:0% +things that get closer and closer + + + align:start position:0% +things that get closer and closer +reducing your error as you go along uh + + align:start position:0% +reducing your error as you go along uh + + + align:start position:0% +reducing your error as you go along uh +divide and conquer + + align:start position:0% +divide and conquer + + + align:start position:0% +divide and conquer +right and actually I guess in between + + align:start position:0% +right and actually I guess in between + + + align:start position:0% +right and actually I guess in between +their bsection which is really just a + + align:start position:0% +their bsection which is really just a + + + align:start position:0% +their bsection which is really just a +variant of of of successive + + align:start position:0% +variant of of of successive + + + align:start position:0% +variant of of of successive +approximation but divide and conquer as + + align:start position:0% +approximation but divide and conquer as + + + align:start position:0% +approximation but divide and conquer as +a class of algorithm these are tools you + + align:start position:0% +a class of algorithm these are tools you + + + align:start position:0% +a class of algorithm these are tools you +want in your toolbox these are the kinds + + align:start position:0% +want in your toolbox these are the kinds + + + align:start position:0% +want in your toolbox these are the kinds +of algorithms that you should be able to + + align:start position:0% +of algorithms that you should be able to + + + align:start position:0% +of algorithms that you should be able to +recognize and what I'd like you to begin + + align:start position:0% +recognize and what I'd like you to begin + + + align:start position:0% +recognize and what I'd like you to begin +to do is to look at a problem and say + + align:start position:0% +to do is to look at a problem and say + + + align:start position:0% +to do is to look at a problem and say +gee which kind of algorithm is most + + align:start position:0% +gee which kind of algorithm is most + + + align:start position:0% +gee which kind of algorithm is most +likely to be successful on this problem + + align:start position:0% +likely to be successful on this problem + + + align:start position:0% +likely to be successful on this problem +and map it into that + + align:start position:0% +and map it into that + + + align:start position:0% +and map it into that +case Okay starting next don't worry I'm + + align:start position:0% +case Okay starting next don't worry I'm + + + align:start position:0% +case Okay starting next don't worry I'm +not going to quit 36 minutes after I got + + align:start position:0% +not going to quit 36 minutes after I got + + + align:start position:0% +not going to quit 36 minutes after I got +one more topic for today but jumping + + align:start position:0% +one more topic for today but jumping + + + align:start position:0% +one more topic for today but jumping +ahead I'm going to skip in a second now + + align:start position:0% +ahead I'm going to skip in a second now + + + align:start position:0% +ahead I'm going to skip in a second now +to talk about one last linguistic thing + + align:start position:0% +to talk about one last linguistic thing + + + align:start position:0% +to talk about one last linguistic thing +from from python but I want to preface + + align:start position:0% +from from python but I want to preface + + + align:start position:0% +from from python but I want to preface +Professor good tag is going to pick up + + align:start position:0% +Professor good tag is going to pick up + + + align:start position:0% +Professor good tag is going to pick up +next week and what we're going to start + + align:start position:0% +next week and what we're going to start + + + align:start position:0% +next week and what we're going to start +doing then is taking these classes of + + align:start position:0% +doing then is taking these classes of + + + align:start position:0% +doing then is taking these classes of +algorithms and start start looking at + + align:start position:0% +algorithms and start start looking at + + + align:start position:0% +algorithms and start start looking at +much more complex algorithms things + + align:start position:0% +much more complex algorithms things + + + align:start position:0% +much more complex algorithms things +you're more likely to use in problems + + align:start position:0% +you're more likely to use in problems + + + align:start position:0% +you're more likely to use in problems +things like napsack Pro napsack problems + + align:start position:0% +things like napsack Pro napsack problems + + + align:start position:0% +things like napsack Pro napsack problems +as we move ahead but the tools you've + + align:start position:0% +as we move ahead but the tools you've + + + align:start position:0% +as we move ahead but the tools you've +seen so far are really the things that + + align:start position:0% +seen so far are really the things that + + + align:start position:0% +seen so far are really the things that +we're going to see as we build those + + align:start position:0% +we're going to see as we build those + + + align:start position:0% +we're going to see as we build those +algorithms okay I want to spend the last + + align:start position:0% +algorithms okay I want to spend the last + + + align:start position:0% +algorithms okay I want to spend the last +portion of this lecture doing one last + + align:start position:0% +portion of this lecture doing one last + + + align:start position:0% +portion of this lecture doing one last +piece of linguistic stuff one last + + align:start position:0% +piece of linguistic stuff one last + + + align:start position:0% +piece of linguistic stuff one last +little uh thing from Python and that's + + align:start position:0% +little uh thing from Python and that's + + + align:start position:0% +little uh thing from Python and that's +to talk about + + align:start position:0% + + + + align:start position:0% + +exceptions + + align:start position:0% +exceptions + + + align:start position:0% +exceptions +okay you've actually seen exceptions a + + align:start position:0% +okay you've actually seen exceptions a + + + align:start position:0% +okay you've actually seen exceptions a +lot you just didn't know that's what + + align:start position:0% +lot you just didn't know that's what + + + align:start position:0% +lot you just didn't know that's what +they were because exceptions show up + + align:start position:0% +they were because exceptions show up + + + align:start position:0% +they were because exceptions show up +everywhere in Python and let me give you + + align:start position:0% +everywhere in Python and let me give you + + + align:start position:0% +everywhere in Python and let me give you +a couple of + + align:start position:0% +a couple of + + + align:start position:0% +a couple of +examples clear some space here + + align:start position:0% +examples clear some space here + + + align:start position:0% +examples clear some space here +if I type in that + + align:start position:0% +if I type in that + + + align:start position:0% +if I type in that +expression I get an error right because + + align:start position:0% +expression I get an error right because + + + align:start position:0% +expression I get an error right because +it's not defined but in fact what this + + align:start position:0% +it's not defined but in fact what this + + + align:start position:0% +it's not defined but in fact what this +did was it threw an exception and the + + align:start position:0% +did was it threw an exception and the + + + align:start position:0% +did was it threw an exception and the +exceptions an a called a name error + + align:start position:0% +exceptions an a called a name error + + + align:start position:0% +exceptions an a called a name error +exception it says you gave me something + + align:start position:0% +exception it says you gave me something + + + align:start position:0% +exception it says you gave me something +I didn't know how to deal with I'm going + + align:start position:0% +I didn't know how to deal with I'm going + + + align:start position:0% +I didn't know how to deal with I'm going +to throw it or raise it to use the right + + align:start position:0% +to throw it or raise it to use the right + + + align:start position:0% +to throw it or raise it to use the right +term to somebody in case they can handle + + align:start position:0% +term to somebody in case they can handle + + + align:start position:0% +term to somebody in case they can handle +it but it's a particular kind of of of + + align:start position:0% +it but it's a particular kind of of of + + + align:start position:0% +it but it's a particular kind of of of +exception I might do something like I + + align:start position:0% +exception I might do something like I + + + align:start position:0% +exception I might do something like I +remind you I had test if I do this + + align:start position:0% + + + + align:start position:0% + +try and get the 10th element of a list + + align:start position:0% +try and get the 10th element of a list + + + align:start position:0% +try and get the 10th element of a list +that's only eight long I get what looks + + align:start position:0% +that's only eight long I get what looks + + + align:start position:0% +that's only eight long I get what looks +like an error but it's actually throwing + + align:start position:0% +like an error but it's actually throwing + + + align:start position:0% +like an error but it's actually throwing +an exception and the exception is right + + align:start position:0% +an exception and the exception is right + + + align:start position:0% +an exception and the exception is right +there it says it's an index error that + + align:start position:0% +there it says it's an index error that + + + align:start position:0% +there it says it's an index error that +is it's trying to do something going + + align:start position:0% +is it's trying to do something going + + + align:start position:0% +is it's trying to do something going +beyond the range of what this thing + + align:start position:0% +beyond the range of what this thing + + + align:start position:0% +beyond the range of what this thing +could deal + + align:start position:0% +could deal + + + align:start position:0% +could deal +with okay you say come on I've seen + + align:start position:0% +with okay you say come on I've seen + + + align:start position:0% +with okay you say come on I've seen +these all the time every time I type + + align:start position:0% +these all the time every time I type + + + align:start position:0% +these all the time every time I type +something into my program it does one of + + align:start position:0% +something into my program it does one of + + + align:start position:0% +something into my program it does one of +these things right when we're just + + align:start position:0% +these things right when we're just + + + align:start position:0% +these things right when we're just +interacting with Idol with the + + align:start position:0% +interacting with Idol with the + + + align:start position:0% +interacting with Idol with the +interactive editor or sorry the + + align:start position:0% +interactive editor or sorry the + + + align:start position:0% +interactive editor or sorry the +interactive environment if you like + + align:start position:0% +interactive environment if you like + + + align:start position:0% +interactive environment if you like +that's what you expect what's happening + + align:start position:0% +that's what you expect what's happening + + + align:start position:0% +that's what you expect what's happening +is that we're typing in something an + + align:start position:0% +is that we're typing in something an + + + align:start position:0% +is that we're typing in something an +expression it doesn't know how to deal + + align:start position:0% +expression it doesn't know how to deal + + + align:start position:0% +expression it doesn't know how to deal +with it's raising the exception but it's + + align:start position:0% +with it's raising the exception but it's + + + align:start position:0% +with it's raising the exception but it's +this simply bubbling up to the top level + + align:start position:0% +this simply bubbling up to the top level + + + align:start position:0% +this simply bubbling up to the top level +saying you've got a + + align:start position:0% +saying you've got a + + + align:start position:0% +saying you've got a +problemos it's been a long day suppose + + align:start position:0% +problemos it's been a long day suppose + + + align:start position:0% +problemos it's been a long day suppose +instead you're in the middle of some + + align:start position:0% +instead you're in the middle of some + + + align:start position:0% +instead you're in the middle of some +deep piece of coat and you get one of + + align:start position:0% +deep piece of coat and you get one of + + + align:start position:0% +deep piece of coat and you get one of +these cases it's kind of annoying if it + + align:start position:0% +these cases it's kind of annoying if it + + + align:start position:0% +these cases it's kind of annoying if it +throws it all the way back up to top + + align:start position:0% +throws it all the way back up to top + + + align:start position:0% +throws it all the way back up to top +level for you to fix if it's truly a bug + + align:start position:0% +level for you to fix if it's truly a bug + + + align:start position:0% +level for you to fix if it's truly a bug +that's the right thing to do you want to + + align:start position:0% +that's the right thing to do you want to + + + align:start position:0% +that's the right thing to do you want to +catch it but in many cases exceptions + + align:start position:0% +catch it but in many cases exceptions + + + align:start position:0% +catch it but in many cases exceptions +are things that in fact you as a program + + align:start position:0% +are things that in fact you as a program + + + align:start position:0% +are things that in fact you as a program +designer could have handled so I'm going + + align:start position:0% +designer could have handled so I'm going + + + align:start position:0% +designer could have handled so I'm going +to distinguish in fact between unhandled + + align:start position:0% + + + + align:start position:0% + +exceptions which are the things that we + + align:start position:0% +exceptions which are the things that we + + + align:start position:0% +exceptions which are the things that we +saw + + align:start position:0% +saw + + + align:start position:0% +saw +there and handled exceptions I'm going + + align:start position:0% +there and handled exceptions I'm going + + + align:start position:0% +there and handled exceptions I'm going +to show you in a second how to handle + + align:start position:0% +to show you in a second how to handle + + + align:start position:0% +to show you in a second how to handle +them but let's look at an example what + + align:start position:0% +them but let's look at an example what + + + align:start position:0% +them but let's look at an example what +do I mean by a handled + + align:start position:0% +do I mean by a handled + + + align:start position:0% +do I mean by a handled +exception well let's look at the next + + align:start position:0% +exception well let's look at the next + + + align:start position:0% +exception well let's look at the next +piece of + + align:start position:0% +piece of + + + align:start position:0% +piece of +code okay it's right here it's called + + align:start position:0% +code okay it's right here it's called + + + align:start position:0% +code okay it's right here it's called +read float look at it in a second + + align:start position:0% +read float look at it in a second + + + align:start position:0% +read float look at it in a second +well let me set set the stage up for + + align:start position:0% +well let me set set the stage up for + + + align:start position:0% +well let me set set the stage up for +this suppose I want to input or sorry I + + align:start position:0% +this suppose I want to input or sorry I + + + align:start position:0% +this suppose I want to input or sorry I +want you as a user to input a floating + + align:start position:0% +want you as a user to input a floating + + + align:start position:0% +want you as a user to input a floating +Point number right we talked about + + align:start position:0% +Point number right we talked about + + + align:start position:0% +Point number right we talked about +things you could do to try and make sure + + align:start position:0% +things you could do to try and make sure + + + align:start position:0% +things you could do to try and make sure +that happens you could run through a + + align:start position:0% +that happens you could run through a + + + align:start position:0% +that happens you could run through a +little Loop to say keep trying until you + + align:start position:0% +little Loop to say keep trying until you + + + align:start position:0% +little Loop to say keep trying until you +get one but one of the ways I could deal + + align:start position:0% +get one but one of the ways I could deal + + + align:start position:0% +get one but one of the ways I could deal +with it is what's shown here what's this + + align:start position:0% +with it is what's shown here what's this + + + align:start position:0% +with it is what's shown here what's this +little Loop say to do this little Loop + + align:start position:0% +little Loop say to do this little Loop + + + align:start position:0% +little Loop say to do this little Loop +says oops wrong one this little Loop + + align:start position:0% +says oops wrong one this little Loop + + + align:start position:0% +says oops wrong one this little Loop +says I'm going to write a function or + + align:start position:0% +says I'm going to write a function or + + + align:start position:0% +says I'm going to write a function or +procedure that takes in two messages I'm + + align:start position:0% +procedure that takes in two messages I'm + + + align:start position:0% +procedure that takes in two messages I'm +going to run through a loop and I'm + + align:start position:0% +going to run through a loop and I'm + + + align:start position:0% +going to run through a loop and I'm +going to request some input which I'm + + align:start position:0% +going to request some input which I'm + + + align:start position:0% +going to request some input which I'm +going to read in with with raw input I'm + + align:start position:0% +going to read in with with raw input I'm + + + align:start position:0% +going to read in with with raw input I'm +going to store that into Val and this as + + align:start position:0% +going to store that into Val and this as + + + align:start position:0% +going to store that into Val and this as +you might expect I'm going to then try + + align:start position:0% +you might expect I'm going to then try + + + align:start position:0% +you might expect I'm going to then try +and see if I can convert that into a + + align:start position:0% +and see if I can convert that into a + + + align:start position:0% +and see if I can convert that into a +float oh wait a minute that's a little + + align:start position:0% +float oh wait a minute that's a little + + + align:start position:0% +float oh wait a minute that's a little +different than what we did last time + + align:start position:0% +different than what we did last time + + + align:start position:0% +different than what we did last time +right last time we checked the type and + + align:start position:0% +right last time we checked the type and + + + align:start position:0% +right last time we checked the type and +said if it is a float you're okay if not + + align:start position:0% +said if it is a float you're okay if not + + + align:start position:0% +said if it is a float you're okay if not +carry on this case what would happen + + align:start position:0% +carry on this case what would happen + + + align:start position:0% +carry on this case what would happen +well float is going to try and do the + + align:start position:0% +well float is going to try and do the + + + align:start position:0% +well float is going to try and do the +the coion it's going to try and turn it + + align:start position:0% +the coion it's going to try and turn it + + + align:start position:0% +the coion it's going to try and turn it +into a floating Point number if it does + + align:start position:0% +into a floating Point number if it does + + + align:start position:0% +into a floating Point number if it does +I'm great right and i' like this to + + align:start position:0% +I'm great right and i' like this to + + + align:start position:0% +I'm great right and i' like this to +return Val if it doesn't float's going + + align:start position:0% +return Val if it doesn't float's going + + + align:start position:0% +return Val if it doesn't float's going +to throw or raise to use the right term + + align:start position:0% +to throw or raise to use the right term + + + align:start position:0% +to throw or raise to use the right term +an exception it's going to say something + + align:start position:0% +an exception it's going to say something + + + align:start position:0% +an exception it's going to say something +like a type error in fact let's try it + + align:start position:0% +like a type error in fact let's try it + + + align:start position:0% +like a type error in fact let's try it +over here right if I go over here and I + + align:start position:0% +over here right if I go over here and I + + + align:start position:0% +over here right if I go over here and I +say float of three it's going to do the + + align:start position:0% +say float of three it's going to do the + + + align:start position:0% +say float of three it's going to do the +conversion but if I say turn this into a + + align:start position:0% +conversion but if I say turn this into a + + + align:start position:0% +conversion but if I say turn this into a +float ah it throws a value error + + align:start position:0% +float ah it throws a value error + + + align:start position:0% +float ah it throws a value error +exception it says it's wrong kind of + + align:start position:0% +exception it says it's wrong kind of + + + align:start position:0% +exception it says it's wrong kind of +value that I've got so I'm going to + + align:start position:0% +value that I've got so I'm going to + + + align:start position:0% +value that I've got so I'm going to +write a little piece of code that says + + align:start position:0% +write a little piece of code that says + + + align:start position:0% +write a little piece of code that says +if it gives me a float I'm set but if + + align:start position:0% +if it gives me a float I'm set but if + + + align:start position:0% +if it gives me a float I'm set but if +not I'd like to have the code handled + + align:start position:0% +not I'd like to have the code handled + + + align:start position:0% +not I'd like to have the code handled +the exception and that's what this funky + + align:start position:0% +the exception and that's what this funky + + + align:start position:0% +the exception and that's what this funky +Tri accept thing does okay this is a tri + + align:start position:0% +Tri accept thing does okay this is a tri + + + align:start position:0% +Tri accept thing does okay this is a tri +accept + + align:start position:0% + + + + align:start position:0% + +block and here's the flow of control + + align:start position:0% +block and here's the flow of control + + + align:start position:0% +block and here's the flow of control +that takes place in there when I hit a + + align:start position:0% +that takes place in there when I hit a + + + align:start position:0% +that takes place in there when I hit a +try Block it's going to literally do + + align:start position:0% +try Block it's going to literally do + + + align:start position:0% +try Block it's going to literally do +that it's going to try and execute the + + align:start position:0% +that it's going to try and execute the + + + align:start position:0% +that it's going to try and execute the +instructions if it can successfully + + align:start position:0% +instructions if it can successfully + + + align:start position:0% +instructions if it can successfully +execute the instructions it is going to + + align:start position:0% +execute the instructions it is going to + + + align:start position:0% +execute the instructions it is going to +skip past the accept block and just + + align:start position:0% +skip past the accept block and just + + + align:start position:0% +skip past the accept block and just +carry on with the rest of the code if + + align:start position:0% +carry on with the rest of the code if + + + align:start position:0% +carry on with the rest of the code if +however it raises an + + align:start position:0% +however it raises an + + + align:start position:0% +however it raises an +exception that exception at least in + + align:start position:0% +exception that exception at least in + + + align:start position:0% +exception that exception at least in +this case where it's a pure accept with + + align:start position:0% +this case where it's a pure accept with + + + align:start position:0% +this case where it's a pure accept with +no tags on it is going to get if you + + align:start position:0% +no tags on it is going to get if you + + + align:start position:0% +no tags on it is going to get if you +like thrown directly to the accept block + + align:start position:0% +like thrown directly to the accept block + + + align:start position:0% +like thrown directly to the accept block +and it's going to try and execute that + + align:start position:0% +and it's going to try and execute that + + + align:start position:0% +and it's going to try and execute that +so notice what's going to happen here + + align:start position:0% +so notice what's going to happen here + + + align:start position:0% +so notice what's going to happen here +then if I give it something that can be + + align:start position:0% +then if I give it something that can be + + + align:start position:0% +then if I give it something that can be +turned into a float I come in here I + + align:start position:0% +turned into a float I come in here I + + + align:start position:0% +turned into a float I come in here I +read the input I'm if it can be turned + + align:start position:0% +read the input I'm if it can be turned + + + align:start position:0% +read the input I'm if it can be turned +into a float I'm going to just return + + align:start position:0% +into a float I'm going to just return + + + align:start position:0% +into a float I'm going to just return +the value and I'm set if not it's + + align:start position:0% +the value and I'm set if not it's + + + align:start position:0% +the value and I'm set if not it's +basically going to throw it to this + + align:start position:0% +basically going to throw it to this + + + align:start position:0% +basically going to throw it to this +point in which case I'm going to print + + align:start position:0% +point in which case I'm going to print + + + align:start position:0% +point in which case I'm going to print +out an error message and oh yeah I'm + + align:start position:0% +out an error message and oh yeah I'm + + + align:start position:0% +out an error message and oh yeah I'm +still in that while loop so it's going + + align:start position:0% +still in that while loop so it's going + + + align:start position:0% +still in that while loop so it's going +to go around so in fact if I go here and + + align:start position:0% +to go around so in fact if I go here and + + + align:start position:0% +to go around so in fact if I go here and +let me uncomment + + align:start position:0% +let me uncomment + + + align:start position:0% +let me uncomment +this and run the + + align:start position:0% +this and run the + + + align:start position:0% +this and run the +code says enter a float and if I give it + + align:start position:0% +code says enter a float and if I give it + + + align:start position:0% +code says enter a float and if I give it +something that can + + align:start position:0% + + + + align:start position:0% + +be uh sorry I've got yes never mind the + + align:start position:0% +be uh sorry I've got yes never mind the + + + align:start position:0% +be uh sorry I've got yes never mind the +grades crap uh where did I have + + align:start position:0% +grades crap uh where did I have + + + align:start position:0% +grades crap uh where did I have +that let me comment that out + + align:start position:0% +that let me comment that out + + + align:start position:0% +that let me comment that out +somehow it's appropriate in the middle + + align:start position:0% +somehow it's appropriate in the middle + + + align:start position:0% +somehow it's appropriate in the middle +of my lecture for it to say whoops at me + + align:start position:0% +of my lecture for it to say whoops at me + + + align:start position:0% +of my lecture for it to say whoops at me +but uh wasn't what I + + align:start position:0% +but uh wasn't what I + + + align:start position:0% +but uh wasn't what I +intended and we will try this + + align:start position:0% + + + + align:start position:0% + +again okay says enter a float I give it + + align:start position:0% +again okay says enter a float I give it + + + align:start position:0% +again okay says enter a float I give it +something that can be converted into a + + align:start position:0% +something that can be converted into a + + + align:start position:0% +something that can be converted into a +float it says fine let me go back and + + align:start position:0% +float it says fine let me go back and + + + align:start position:0% +float it says fine let me go back and +run it again though if I run it again it + + align:start position:0% +run it again though if I run it again it + + + align:start position:0% +run it again though if I run it again it +says enter a + + align:start position:0% + + + + align:start position:0% + +float aha it goes into that except + + align:start position:0% +float aha it goes into that except + + + align:start position:0% +float aha it goes into that except +portion prints out a message and goes + + align:start position:0% +portion prints out a message and goes + + + align:start position:0% +portion prints out a message and goes +back around the H Loop to say try again + + align:start position:0% +back around the H Loop to say try again + + + align:start position:0% +back around the H Loop to say try again +and it's going to keep keep doing this + + align:start position:0% +and it's going to keep keep doing this + + + align:start position:0% +and it's going to keep keep doing this +until I give it something that does + + align:start position:0% +until I give it something that does + + + align:start position:0% +until I give it something that does +serve as a + + align:start position:0% +serve as a + + + align:start position:0% +serve as a +float all right so an exception then has + + align:start position:0% +float all right so an exception then has + + + align:start position:0% +float all right so an exception then has +this format that I can control as a + + align:start position:0% +this format that I can control as a + + + align:start position:0% +this format that I can control as a +programmer why would I want to use this + + align:start position:0% +programmer why would I want to use this + + + align:start position:0% +programmer why would I want to use this +well some things I can actually expect + + align:start position:0% +well some things I can actually expect + + + align:start position:0% +well some things I can actually expect +may happen and I want to handle them the + + align:start position:0% +may happen and I want to handle them the + + + align:start position:0% +may happen and I want to handle them the +float example is a simple one I'm going + + align:start position:0% +float example is a simple one I'm going + + + align:start position:0% +float example is a simple one I'm going +to generalize in a second here's a + + align:start position:0% +to generalize in a second here's a + + + align:start position:0% +to generalize in a second here's a +better example I'm writing a piece of + + align:start position:0% +better example I'm writing a piece of + + + align:start position:0% +better example I'm writing a piece of +code that wants to input a file and I + + align:start position:0% +code that wants to input a file and I + + + align:start position:0% +code that wants to input a file and I +can certainly imagine something that + + align:start position:0% +can certainly imagine something that + + + align:start position:0% +can certainly imagine something that +says give me the file name I'm going to + + align:start position:0% +says give me the file name I'm going to + + + align:start position:0% +says give me the file name I'm going to +do something with it I can't guarantee + + align:start position:0% +do something with it I can't guarantee + + + align:start position:0% +do something with it I can't guarantee +that the file may exist under that name + + align:start position:0% +that the file may exist under that name + + + align:start position:0% +that the file may exist under that name +but I know that's something that might + + align:start position:0% +but I know that's something that might + + + align:start position:0% +but I know that's something that might +occur so a nice way to handle it is to + + align:start position:0% +occur so a nice way to handle it is to + + + align:start position:0% +occur so a nice way to handle it is to +write it as an exception that says + + align:start position:0% +write it as an exception that says + + + align:start position:0% +write it as an exception that says +here's what I want to do if I get the + + align:start position:0% +here's what I want to do if I get the + + + align:start position:0% +here's what I want to do if I get the +file but just in case the file name's + + align:start position:0% +file but just in case the file name's + + + align:start position:0% +file but just in case the file name's +not there here's what I want to do in + + align:start position:0% +not there here's what I want to do in + + + align:start position:0% +not there here's what I want to do in +that case to handle it let me specify + + align:start position:0% +that case to handle it let me specify + + + align:start position:0% +that case to handle it let me specify +what the exception should + + align:start position:0% +what the exception should + + + align:start position:0% +what the exception should +do all right in the example I just wrote + + align:start position:0% +do all right in the example I just wrote + + + align:start position:0% +do all right in the example I just wrote +here this is pretty trivial right okay + + align:start position:0% +here this is pretty trivial right okay + + + align:start position:0% +here this is pretty trivial right okay +I'm trying to input floats I could + + align:start position:0% +I'm trying to input floats I could + + + align:start position:0% +I'm trying to input floats I could +generalize this pretty nicely imagine + + align:start position:0% +generalize this pretty nicely imagine + + + align:start position:0% +generalize this pretty nicely imagine +the same kind of idea where I want to + + align:start position:0% +the same kind of idea where I want to + + + align:start position:0% +the same kind of idea where I want to +Simply say I want to take input of + + align:start position:0% +Simply say I want to take input of + + + align:start position:0% +Simply say I want to take input of +anything and try and see how to make + + align:start position:0% +anything and try and see how to make + + + align:start position:0% +anything and try and see how to make +sure I get the right kind of thing I + + align:start position:0% +sure I get the right kind of thing I + + + align:start position:0% +sure I get the right kind of thing I +want to make it + + align:start position:0% + + + + align:start position:0% + +polymorphic well that's pretty easy to + + align:start position:0% +polymorphic well that's pretty easy to + + + align:start position:0% +polymorphic well that's pretty easy to +do that is basically the next example + + align:start position:0% +do that is basically the next example + + + align:start position:0% +do that is basically the next example +right + + align:start position:0% +right + + + align:start position:0% +right +here okay in fact let me comment this + + align:start position:0% +here okay in fact let me comment this + + + align:start position:0% +here okay in fact let me comment this +one + + align:start position:0% +one + + + align:start position:0% +one +out I can do exactly the same kind of + + align:start position:0% +out I can do exactly the same kind of + + + align:start position:0% +out I can do exactly the same kind of +thing right but now what I'm going to + + align:start position:0% +thing right but now what I'm going to + + + align:start position:0% +thing right but now what I'm going to +try and do is read in a set of values + + align:start position:0% +try and do is read in a set of values + + + align:start position:0% +try and do is read in a set of values +where I'm going to give it a type of + + align:start position:0% +where I'm going to give it a type of + + + align:start position:0% +where I'm going to give it a type of +value as well as the messages formats + + align:start position:0% +value as well as the messages formats + + + align:start position:0% +value as well as the messages formats +the same I'm going to ask for some input + + align:start position:0% +the same I'm going to ask for some input + + + align:start position:0% +the same I'm going to ask for some input +and then I'm going to use that procedure + + align:start position:0% +and then I'm going to use that procedure + + + align:start position:0% +and then I'm going to use that procedure +to check is this the right type of value + + align:start position:0% +to check is this the right type of value + + + align:start position:0% +to check is this the right type of value +and I'm going to try and use that to do + + align:start position:0% +and I'm going to try and use that to do + + + align:start position:0% +and I'm going to try and use that to do +the coercion if you like same thing if + + align:start position:0% +the coercion if you like same thing if + + + align:start position:0% +the coercion if you like same thing if +it works I'm going to skip that if it + + align:start position:0% +it works I'm going to skip that if it + + + align:start position:0% +it works I'm going to skip that if it +not it's going to throw the + + align:start position:0% +not it's going to throw the + + + align:start position:0% +not it's going to throw the +exception why is this nice well that's a + + align:start position:0% +exception why is this nice well that's a + + + align:start position:0% +exception why is this nice well that's a +handy piece of code right because + + align:start position:0% +handy piece of code right because + + + align:start position:0% +handy piece of code right because +imagine I've got that now I can now + + align:start position:0% +imagine I've got that now I can now + + + align:start position:0% +imagine I've got that now I can now +store that away in some file name input + + align:start position:0% +store that away in some file name input + + + align:start position:0% +store that away in some file name input +top py and import it into every one of + + align:start position:0% +top py and import it into every one of + + + align:start position:0% +top py and import it into every one of +my procedure functions sorry my files of + + align:start position:0% +my procedure functions sorry my files of + + + align:start position:0% +my procedure functions sorry my files of +procedures because it's a standard way + + align:start position:0% +procedures because it's a standard way + + + align:start position:0% +procedures because it's a standard way +of now giving me the + + align:start position:0% +of now giving me the + + + align:start position:0% +of now giving me the +input okay so far though I've just shown + + align:start position:0% +input okay so far though I've just shown + + + align:start position:0% +input okay so far though I've just shown +you what happens inside a piece of code + + align:start position:0% +you what happens inside a piece of code + + + align:start position:0% +you what happens inside a piece of code +it raises an exception it goes to that + + align:start position:0% +it raises an exception it goes to that + + + align:start position:0% +it raises an exception it goes to that +except Clause we don't have to use it + + align:start position:0% +except Clause we don't have to use it + + + align:start position:0% +except Clause we don't have to use it +just inside of one place we can actually + + align:start position:0% +just inside of one place we can actually + + + align:start position:0% +just inside of one place we can actually +use it more generally and that gets me + + align:start position:0% +use it more generally and that gets me + + + align:start position:0% +use it more generally and that gets me +to the last example I wanted to show you + + align:start position:0% +to the last example I wanted to show you + + + align:start position:0% +to the last example I wanted to show you +and let me uncomment + + align:start position:0% + + + + align:start position:0% + +this let's take a look at this code + + align:start position:0% +this let's take a look at this code + + + align:start position:0% +this let's take a look at this code +this looks like a handy piece of code to + + align:start position:0% +this looks like a handy piece of code to + + + align:start position:0% +this looks like a handy piece of code to +have given what we just recently did to + + align:start position:0% +have given what we just recently did to + + + align:start position:0% +have given what we just recently did to +you right get grades it's a little + + align:start position:0% +you right get grades it's a little + + + align:start position:0% +you right get grades it's a little +function that's going to say give me a + + align:start position:0% +function that's going to say give me a + + + align:start position:0% +function that's going to say give me a +file name and I'm going to go off and + + align:start position:0% +file name and I'm going to go off and + + + align:start position:0% +file name and I'm going to go off and +open that up okay and bind it to a local + + align:start position:0% +open that up okay and bind it to a local + + + align:start position:0% +open that up okay and bind it to a local +variable and if it's successful then I + + align:start position:0% +variable and if it's successful then I + + + align:start position:0% +variable and if it's successful then I +just like to go off and do some things + + align:start position:0% +just like to go off and do some things + + + align:start position:0% +just like to go off and do some things +like turn it into a list so I can + + align:start position:0% +like turn it into a list so I can + + + align:start position:0% +like turn it into a list so I can +compute average score or distributions + + align:start position:0% +compute average score or distributions + + + align:start position:0% +compute average score or distributions +or something else I don't really care + + align:start position:0% +or something else I don't really care + + + align:start position:0% +or something else I don't really care +what's going on in here notice though + + align:start position:0% +what's going on in here notice though + + + align:start position:0% +what's going on in here notice though +what I've done + + align:start position:0% +what I've done + + + align:start position:0% +what I've done +open if it doesn't succeed is going to + + align:start position:0% +open if it doesn't succeed is going to + + + align:start position:0% +open if it doesn't succeed is going to +to raise a particular kind of exception + + align:start position:0% +to raise a particular kind of exception + + + align:start position:0% +to raise a particular kind of exception +called IO a and so I've done a little + + align:start position:0% +called IO a and so I've done a little + + + align:start position:0% +called IO a and so I've done a little +bit different thing here which is I've + + align:start position:0% +bit different thing here which is I've + + + align:start position:0% +bit different thing here which is I've +put the except part of the block with IO + + align:start position:0% +put the except part of the block with IO + + + align:start position:0% +put the except part of the block with IO +a what does that say it says if in the + + align:start position:0% +a what does that say it says if in the + + + align:start position:0% +a what does that say it says if in the +code up here I get a an exception of + + align:start position:0% +code up here I get a an exception of + + + align:start position:0% +code up here I get a an exception of +that sort I'm going to go to this place + + align:start position:0% +that sort I'm going to go to this place + + + align:start position:0% +that sort I'm going to go to this place +to handle it on the other hand if I'm + + align:start position:0% +to handle it on the other hand if I'm + + + align:start position:0% +to handle it on the other hand if I'm +inside this procedure and some other + + align:start position:0% +inside this procedure and some other + + + align:start position:0% +inside this procedure and some other +exception is raised that's not tagged by + + align:start position:0% +exception is raised that's not tagged by + + + align:start position:0% +exception is raised that's not tagged by +that one it's going to raise it up the + + align:start position:0% +that one it's going to raise it up the + + + align:start position:0% +that one it's going to raise it up the +chain if that procedure was called by + + align:start position:0% +chain if that procedure was called by + + + align:start position:0% +chain if that procedure was called by +some other procedure is going to say is + + align:start position:0% +some other procedure is going to say is + + + align:start position:0% +some other procedure is going to say is +there an exception Block in there that + + align:start position:0% +there an exception Block in there that + + + align:start position:0% +there an exception Block in there that +can handle that if not I'm going to keep + + align:start position:0% +can handle that if not I'm going to keep + + + align:start position:0% +can handle that if not I'm going to keep +going up the chain until eventually I + + align:start position:0% +going up the chain until eventually I + + + align:start position:0% +going up the chain until eventually I +get to the top level and you can see + + align:start position:0% +get to the top level and you can see + + + align:start position:0% +get to the top level and you can see +that down here I'm going to run this in + + align:start position:0% +that down here I'm going to run this in + + + align:start position:0% +that down here I'm going to run this in +a second but this is just a piece of + + align:start position:0% +a second but this is just a piece of + + + align:start position:0% +a second but this is just a piece of +code where I'm going to say gee if I can + + align:start position:0% +code where I'm going to say gee if I can + + + align:start position:0% +code where I'm going to say gee if I can +get the grades do something if + + align:start position:0% +get the grades do something if + + + align:start position:0% +get the grades do something if +not carry on right and if I go ahead and + + align:start position:0% +not carry on right and if I go ahead and + + + align:start position:0% +not carry on right and if I go ahead and +run + + align:start position:0% +run + + + align:start position:0% +run +this and now it's going to say whoops at + + align:start position:0% +this and now it's going to say whoops at + + + align:start position:0% +this and now it's going to say whoops at +me okay what + + align:start position:0% +me okay what + + + align:start position:0% +me okay what +happened I'm down here and try I'm + + align:start position:0% +happened I'm down here and try I'm + + + align:start position:0% +happened I'm down here and try I'm +trying to do get grades which is a call + + align:start position:0% +trying to do get grades which is a call + + + align:start position:0% +trying to do get grades which is a call +to that function which is not bound in + + align:start position:0% +to that function which is not bound in + + + align:start position:0% +to that function which is not bound in +my in my in my there in my computer that + + align:start position:0% +my in my in my there in my computer that + + + align:start position:0% +my in my in my there in my computer that +says it's in here it's in this Tri block + + align:start position:0% +says it's in here it's in this Tri block + + + align:start position:0% +says it's in here it's in this Tri block +it raised an exception but it wasn't an + + align:start position:0% +it raised an exception but it wasn't an + + + align:start position:0% +it raised an exception but it wasn't an +IO error so it passes it back past this + + align:start position:0% +IO error so it passes it back past this + + + align:start position:0% +IO error so it passes it back past this +exception up to this level which gets to + + align:start position:0% +exception up to this level which gets to + + + align:start position:0% +exception up to this level which gets to +that + + align:start position:0% +that + + + align:start position:0% +that +exception so let me say this a little + + align:start position:0% +exception so let me say this a little + + + align:start position:0% +exception so let me say this a little +bit better then I can write exceptions + + align:start position:0% +bit better then I can write exceptions + + + align:start position:0% +bit better then I can write exceptions +inside a piece of code try this if it + + align:start position:0% +inside a piece of code try this if it + + + align:start position:0% +inside a piece of code try this if it +doesn't work I can have an exception + + align:start position:0% +doesn't work I can have an exception + + + align:start position:0% +doesn't work I can have an exception +that catches any error at that level or + + align:start position:0% +that catches any error at that level or + + + align:start position:0% +that catches any error at that level or +I can say catch only these kinds of + + align:start position:0% +I can say catch only these kinds of + + + align:start position:0% +I can say catch only these kinds of +Errors at that level otherwise pass them + + align:start position:0% +Errors at that level otherwise pass them + + + align:start position:0% +Errors at that level otherwise pass them +up the chain and that exception will + + align:start position:0% +up the chain and that exception will + + + align:start position:0% +up the chain and that exception will +keep getting passed up the chain of + + align:start position:0% +keep getting passed up the chain of + + + align:start position:0% +keep getting passed up the chain of +calls until it either gets to top level + + align:start position:0% +calls until it either gets to top level + + + align:start position:0% +calls until it either gets to top level +in which case it looks like what you see + + align:start position:0% +in which case it looks like what you see + + + align:start position:0% +in which case it looks like what you see +all the time looks like an error but it + + align:start position:0% +all the time looks like an error but it + + + align:start position:0% +all the time looks like an error but it +tells you what the error came from or it + + align:start position:0% +tells you what the error came from or it + + + align:start position:0% +tells you what the error came from or it +gets an exception Handler that can deal + + align:start position:0% +gets an exception Handler that can deal + + + align:start position:0% +gets an exception Handler that can deal +with + + align:start position:0% +with + + + align:start position:0% +with +it okay so the last thing to say about + + align:start position:0% +it okay so the last thing to say about + + + align:start position:0% +it okay so the last thing to say about +this is what's the difference between an + + align:start position:0% +this is what's the difference between an + + + align:start position:0% +this is what's the difference between an +exception and an assert + + align:start position:0% + + + + align:start position:0% + +right we introduced asserts earlier on + + align:start position:0% +right we introduced asserts earlier on + + + align:start position:0% +right we introduced asserts earlier on +you've actually seen them in some pieces + + align:start position:0% +you've actually seen them in some pieces + + + align:start position:0% +you've actually seen them in some pieces +of code so um you know what's the + + align:start position:0% +of code so um you know what's the + + + align:start position:0% +of code so um you know what's the +difference between the two of + + align:start position:0% +difference between the two of + + + align:start position:0% +difference between the two of +them well here's my way of describing + + align:start position:0% +them well here's my way of describing + + + align:start position:0% +them well here's my way of describing +it the goal of an assert or an assert + + align:start position:0% +it the goal of an assert or an assert + + + align:start position:0% +it the goal of an assert or an assert +statement is basically to say look you + + align:start position:0% +statement is basically to say look you + + + align:start position:0% +statement is basically to say look you +can be sure that my function is going to + + align:start position:0% +can be sure that my function is going to + + + align:start position:0% +can be sure that my function is going to +give this kind of result if you give me + + align:start position:0% +give this kind of result if you give me + + + align:start position:0% +give this kind of result if you give me +inputs of a particular type sorry wrong + + align:start position:0% +inputs of a particular type sorry wrong + + + align:start position:0% +inputs of a particular type sorry wrong +way saying it if you give me inputs that + + align:start position:0% +way saying it if you give me inputs that + + + align:start position:0% +way saying it if you give me inputs that +satisfy some particular + + align:start position:0% +satisfy some particular + + + align:start position:0% +satisfy some particular +constraints right that was the kind of + + align:start position:0% +constraints right that was the kind of + + + align:start position:0% +constraints right that was the kind of +thing you saw aert said here are some + + align:start position:0% +thing you saw aert said here are some + + + align:start position:0% +thing you saw aert said here are some +conditions to test if they're true I'm + + align:start position:0% +conditions to test if they're true I'm + + + align:start position:0% +conditions to test if they're true I'm +going to let the rest of the code run if + + align:start position:0% +going to let the rest of the code run if + + + align:start position:0% +going to let the rest of the code run if +not I'm going to throw an error right so + + align:start position:0% +not I'm going to throw an error right so + + + align:start position:0% +not I'm going to throw an error right so +the assertion is basically saying we got + + align:start position:0% +the assertion is basically saying we got + + + align:start position:0% +the assertion is basically saying we got +some + + align:start position:0% + + + + align:start position:0% + +preconditions those are the Clauses + + align:start position:0% +preconditions those are the Clauses + + + align:start position:0% +preconditions those are the Clauses +inside the assert that have to be true + + align:start position:0% +inside the assert that have to be true + + + align:start position:0% +inside the assert that have to be true +and there's a post + + align:start position:0% + + + + align:start position:0% + +condition and in essence what the assert + + align:start position:0% +condition and in essence what the assert + + + align:start position:0% +condition and in essence what the assert +is saying is or rather the programmer + + align:start position:0% +is saying is or rather the programmer + + + align:start position:0% +is saying is or rather the programmer +saying using the assert is if you give + + align:start position:0% +saying using the assert is if you give + + + align:start position:0% +saying using the assert is if you give +me input that satisfies the + + align:start position:0% +me input that satisfies the + + + align:start position:0% +me input that satisfies the +preconditions I'm guaranteeing to you + + align:start position:0% +preconditions I'm guaranteeing to you + + + align:start position:0% +preconditions I'm guaranteeing to you +that my code is going to give you + + align:start position:0% +that my code is going to give you + + + align:start position:0% +that my code is going to give you +something that that meets the postc + + align:start position:0% +something that that meets the postc + + + align:start position:0% +something that that meets the postc +condition it's going to do the right + + align:start position:0% +condition it's going to do the right + + + align:start position:0% +condition it's going to do the right +thing and as a consequence as you saw + + align:start position:0% +thing and as a consequence as you saw + + + align:start position:0% +thing and as a consequence as you saw +with the asserts if the preconditions + + align:start position:0% +with the asserts if the preconditions + + + align:start position:0% +with the asserts if the preconditions +aren't true it throws an error okay it + + align:start position:0% +aren't true it throws an error okay it + + + align:start position:0% +aren't true it throws an error okay it +goes back up the top level saying stops + + align:start position:0% +goes back up the top level saying stops + + + align:start position:0% +goes back up the top level saying stops +operation immediately and goes back up + + align:start position:0% +operation immediately and goes back up + + + align:start position:0% +operation immediately and goes back up +the top level + + align:start position:0% +the top level + + + align:start position:0% +the top level +okay asserts in fact are nice in the + + align:start position:0% +okay asserts in fact are nice in the + + + align:start position:0% +okay asserts in fact are nice in the +sense that they let you check conditions + + align:start position:0% +sense that they let you check conditions + + + align:start position:0% +sense that they let you check conditions +at debugging time or testing time so you + + align:start position:0% +at debugging time or testing time so you + + + align:start position:0% +at debugging time or testing time so you +can actually use them to see where your + + align:start position:0% +can actually use them to see where your + + + align:start position:0% +can actually use them to see where your +code is + + align:start position:0% +code is + + + align:start position:0% +code is +going an exception when you use an + + align:start position:0% +going an exception when you use an + + + align:start position:0% +going an exception when you use an +exception basically what you're saying + + align:start position:0% +exception basically what you're saying + + + align:start position:0% +exception basically what you're saying +is look you can do anything you want + + align:start position:0% +is look you can do anything you want + + + align:start position:0% +is look you can do anything you want +with my function and you can be sure + + align:start position:0% +with my function and you can be sure + + + align:start position:0% +with my function and you can be sure +that I'm going to tell you if something + + align:start position:0% +that I'm going to tell you if something + + + align:start position:0% +that I'm going to tell you if something +is going wrong and in many cases I'm + + align:start position:0% +is going wrong and in many cases I'm + + + align:start position:0% +is going wrong and in many cases I'm +going to handle it + + align:start position:0% +going to handle it + + + align:start position:0% +going to handle it +myself so as as much as possible the + + align:start position:0% +myself so as as much as possible the + + + align:start position:0% +myself so as as much as possible the +exceptions are going to try and handle + + align:start position:0% +exceptions are going to try and handle + + + align:start position:0% +exceptions are going to try and handle +unexpected things actually wrong term + + align:start position:0% +unexpected things actually wrong term + + + align:start position:0% +unexpected things actually wrong term +you expected them but not what the the + + align:start position:0% +you expected them but not what the the + + + align:start position:0% +you expected them but not what the the +user did it's going to try and handle + + align:start position:0% +user did it's going to try and handle + + + align:start position:0% +user did it's going to try and handle +conditions other than the normal ones + + align:start position:0% +conditions other than the normal ones + + + align:start position:0% +conditions other than the normal ones +itself so you can use the thing in any + + align:start position:0% +itself so you can use the thing in any + + + align:start position:0% +itself so you can use the thing in any +way if it can't it's going to try and + + align:start position:0% +way if it can't it's going to try and + + + align:start position:0% +way if it can't it's going to try and +throw it to somebody else to handle and + + align:start position:0% +throw it to somebody else to handle and + + + align:start position:0% +throw it to somebody else to handle and +only if there is no Handler for that + + align:start position:0% +only if there is no Handler for that + + + align:start position:0% +only if there is no Handler for that +unexpected condition will it come up to + + align:start position:0% +unexpected condition will it come up to + + + align:start position:0% +unexpected condition will it come up to +top level so summarizing better assert + + align:start position:0% +top level so summarizing better assert + + + align:start position:0% +top level so summarizing better assert +is something you put in to say to the + + align:start position:0% +is something you put in to say to the + + + align:start position:0% +is something you put in to say to the +user make sure you're giving me input of + + align:start position:0% +user make sure you're giving me input of + + + align:start position:0% +user make sure you're giving me input of +this type but I'm going to guarantee you + + align:start position:0% +this type but I'm going to guarantee you + + + align:start position:0% +this type but I'm going to guarantee you +the rest of the code works correctly + + align:start position:0% +the rest of the code works correctly + + + align:start position:0% +the rest of the code works correctly +exceptions and exception handlers are + + align:start position:0% +exceptions and exception handlers are + + + align:start position:0% +exceptions and exception handlers are +saying here here are the odd cases that + + align:start position:0% +saying here here are the odd cases that + + + align:start position:0% +saying here here are the odd cases that +I might see and here's what I'd like to + + align:start position:0% +I might see and here's what I'd like to + + + align:start position:0% +I might see and here's what I'd like to +do in those cases in order to try and be + + align:start position:0% +do in those cases in order to try and be + + + align:start position:0% +do in those cases in order to try and be +able to deal with + + align:start position:0% +able to deal with + + + align:start position:0% +able to deal with +them last thing to say is why would you + + align:start position:0% +them last thing to say is why would you + + + align:start position:0% +them last thing to say is why would you +want to have + + align:start position:0% +want to have + + + align:start position:0% +want to have +exceptions well let's go back to that + + align:start position:0% +exceptions well let's go back to that + + + align:start position:0% +exceptions well let's go back to that +case of inputting a simple little + + align:start position:0% +case of inputting a simple little + + + align:start position:0% +case of inputting a simple little +floating + + align:start position:0% +floating + + + align:start position:0% +floating +point if I'm expecting mostly numbers in + + align:start position:0% +point if I'm expecting mostly numbers in + + + align:start position:0% +point if I'm expecting mostly numbers in +I can certainly try and do the coercion + + align:start position:0% +I can certainly try and do the coercion + + + align:start position:0% +I can certainly try and do the coercion +I could have done that just doing the + + align:start position:0% +I could have done that just doing the + + + align:start position:0% +I could have done that just doing the +coercion right the problem is I want to + + align:start position:0% +coercion right the problem is I want to + + + align:start position:0% +coercion right the problem is I want to +know if in fact I've got something + + align:start position:0% +know if in fact I've got something + + + align:start position:0% +know if in fact I've got something +that's not of the form I expect I'm much + + align:start position:0% +that's not of the form I expect I'm much + + + align:start position:0% +that's not of the form I expect I'm much +better having an exception get handled + + align:start position:0% +better having an exception get handled + + + align:start position:0% +better having an exception get handled +at the time of input than to let that + + align:start position:0% +at the time of input than to let that + + + align:start position:0% +at the time of input than to let that +prop that value rather propagate through + + align:start position:0% +prop that value rather propagate through + + + align:start position:0% +prop that value rather propagate through +a whole bunch of code until eventually + + align:start position:0% +a whole bunch of code until eventually + + + align:start position:0% +a whole bunch of code until eventually +it hits an error 17 calls later and you + + align:start position:0% +it hits an error 17 calls later and you + + + align:start position:0% +it hits an error 17 calls later and you +have no clue where it came from so the + + align:start position:0% +have no clue where it came from so the + + + align:start position:0% +have no clue where it came from so the +exceptions are useful when you want to + + align:start position:0% +exceptions are useful when you want to + + + align:start position:0% +exceptions are useful when you want to +have the ability to say I expect in + + align:start position:0% +have the ability to say I expect in + + + align:start position:0% +have the ability to say I expect in +general this kind of behavior but I do + + align:start position:0% +general this kind of behavior but I do + + + align:start position:0% +general this kind of behavior but I do +know there are some other things that + + align:start position:0% +know there are some other things that + + + align:start position:0% +know there are some other things that +might happen and here's what I'd like to + + align:start position:0% +might happen and here's what I'd like to + + + align:start position:0% +might happen and here's what I'd like to +do in each one of those cases but I do + + align:start position:0% +do in each one of those cases but I do + + + align:start position:0% +do in each one of those cases but I do +want to make sure that I don't let a + + align:start position:0% +want to make sure that I don't let a + + + align:start position:0% +want to make sure that I don't let a +value that I'm not expecting pass + + align:start position:0% +value that I'm not expecting pass + + + align:start position:0% +value that I'm not expecting pass +through that goes back to that idea of + + align:start position:0% +through that goes back to that idea of + + + align:start position:0% +through that goes back to that idea of +sort of discipline coding it's easy to + + align:start position:0% +sort of discipline coding it's easy to + + + align:start position:0% +sort of discipline coding it's easy to +have assumptions about what you think + + align:start position:0% +have assumptions about what you think + + + align:start position:0% +have assumptions about what you think +are going to come into the program when + + align:start position:0% +are going to come into the program when + + + align:start position:0% +are going to come into the program when +you write it if you really know what + + align:start position:0% +you write it if you really know what + + + align:start position:0% +you write it if you really know what +they are use an assert but if you think + + align:start position:0% +they are use an assert but if you think + + + align:start position:0% +they are use an assert but if you think +there's going to be some flexibility you + + align:start position:0% +there's going to be some flexibility you + + + align:start position:0% +there's going to be some flexibility you +want to prevent the user getting trapped + + align:start position:0% +want to prevent the user getting trapped + + + align:start position:0% +want to prevent the user getting trapped +in a bad spot and exceptions as a + + align:start position:0% +in a bad spot and exceptions as a + + + align:start position:0% +in a bad spot and exceptions as a +consequence are a good thing to use \ No newline at end of file diff --git a/kiCNa95DnnE.txt b/kiCNa95DnnE.txt new file mode 100644 index 0000000000000000000000000000000000000000..405a2d590e4bfd5f17e299da4d0787bc8c0a470e --- /dev/null +++ b/kiCNa95DnnE.txt @@ -0,0 +1,3875 @@ +align:start position:0% + +so remember as VFR pilot + + align:start position:0% +so remember as VFR pilot + + + align:start position:0% +so remember as VFR pilot +she's gonna be doing stuff that is in + + align:start position:0% +she's gonna be doing stuff that is in + + + align:start position:0% +she's gonna be doing stuff that is in +some ways more challenging than what + + align:start position:0% +some ways more challenging than what + + + align:start position:0% +some ways more challenging than what +airline pilots do because you're always + + align:start position:0% +airline pilots do because you're always + + + align:start position:0% +airline pilots do because you're always +trying to keep clearances from clouds + + align:start position:0% +trying to keep clearances from clouds + + + align:start position:0% +trying to keep clearances from clouds +that the IFR pilots don't care about and + + align:start position:0% +that the IFR pilots don't care about and + + + align:start position:0% +that the IFR pilots don't care about and +if you're flying a low performance + + align:start position:0% +if you're flying a low performance + + + align:start position:0% +if you're flying a low performance +airplane you're also dealing with you + + align:start position:0% +airplane you're also dealing with you + + + align:start position:0% +airplane you're also dealing with you +know flying through the leather instead + + align:start position:0% +know flying through the leather instead + + + align:start position:0% +know flying through the leather instead +of it's going on top of it so while + + align:start position:0% +of it's going on top of it so while + + + align:start position:0% +of it's going on top of it so while +you're the VFR only pilot these + + align:start position:0% +you're the VFR only pilot these + + + align:start position:0% +you're the VFR only pilot these +non-local flights really pay attention + + align:start position:0% +non-local flights really pay attention + + + align:start position:0% +non-local flights really pay attention +to whether airspace go and study this a + + align:start position:0% +to whether airspace go and study this a + + + align:start position:0% +to whether airspace go and study this a +little bit before the exam here are the + + align:start position:0% +little bit before the exam here are the + + + align:start position:0% +little bit before the exam here are the +different kinds remember Class A is up + + align:start position:0% +different kinds remember Class A is up + + + align:start position:0% +different kinds remember Class A is up +high in an instrument clearance Class B + + align:start position:0% +high in an instrument clearance Class B + + + align:start position:0% +high in an instrument clearance Class B +is around the biggest airports class + + align:start position:0% +is around the biggest airports class + + + align:start position:0% +is around the biggest airports class +Charlie's around Manchester New + + align:start position:0% +Charlie's around Manchester New + + + align:start position:0% +Charlie's around Manchester New +Hampshire and D is for Hanscom and E is + + align:start position:0% +Hampshire and D is for Hanscom and E is + + + align:start position:0% +Hampshire and D is for Hanscom and E is +kind of everywhere else okay + + align:start position:0% +kind of everywhere else okay + + + align:start position:0% +kind of everywhere else okay +the goal for the basic VFR weather + + align:start position:0% +the goal for the basic VFR weather + + + align:start position:0% +the goal for the basic VFR weather +minimums is to make sure that an IFR + + align:start position:0% +minimums is to make sure that an IFR + + + align:start position:0% +minimums is to make sure that an IFR +plane coming out of the cloud has time + + align:start position:0% +plane coming out of the cloud has time + + + align:start position:0% +plane coming out of the cloud has time +to see and avoid you because the air + + align:start position:0% +to see and avoid you because the air + + + align:start position:0% +to see and avoid you because the air +traffic controllers job is to separate + + align:start position:0% +traffic controllers job is to separate + + + align:start position:0% +traffic controllers job is to separate +IFR airplanes from each other not to + + align:start position:0% +IFR airplanes from each other not to + + + align:start position:0% +IFR airplanes from each other not to +separate IFR and VFR traffic they will + + align:start position:0% +separate IFR and VFR traffic they will + + + align:start position:0% +separate IFR and VFR traffic they will +tell you about them but you're + + align:start position:0% +tell you about them but you're + + + align:start position:0% +tell you about them but you're +responsible as the VFR pilot for staying + + align:start position:0% +responsible as the VFR pilot for staying + + + align:start position:0% +responsible as the VFR pilot for staying +reasonably clear of clouds so just + + align:start position:0% +reasonably clear of clouds so just + + + align:start position:0% +reasonably clear of clouds so just +review these cloud clearances Class E + + align:start position:0% +review these cloud clearances Class E + + + align:start position:0% +review these cloud clearances Class E +you can see that this is a pretty good + + align:start position:0% +you can see that this is a pretty good + + + align:start position:0% +you can see that this is a pretty good +one to remember for the test 500 below a + + align:start position:0% +one to remember for the test 500 below a + + + align:start position:0% +one to remember for the test 500 below a +thousand above two thousand horizontally + + align:start position:0% +thousand above two thousand horizontally + + + align:start position:0% +thousand above two thousand horizontally +if you're really low in Class G airspace + + align:start position:0% +if you're really low in Class G airspace + + + align:start position:0% +if you're really low in Class G airspace +you can do some crazy stuff again I + + align:start position:0% +you can do some crazy stuff again I + + + align:start position:0% +you can do some crazy stuff again I +don't think this is really there to let + + align:start position:0% +don't think this is really there to let + + + align:start position:0% +don't think this is really there to let +you you know go from Boston to Chicago + + align:start position:0% +you you know go from Boston to Chicago + + + align:start position:0% +you you know go from Boston to Chicago +Scott running with you know one mile of + + align:start position:0% +Scott running with you know one mile of + + + align:start position:0% +Scott running with you know one mile of +visibility and just clear of the clouds + + align:start position:0% +visibility and just clear of the clouds + + + align:start position:0% +visibility and just clear of the clouds +I think it's more to enable people to + + align:start position:0% +I think it's more to enable people to + + + align:start position:0% +I think it's more to enable people to +say take off and do pattern work at + + align:start position:0% +say take off and do pattern work at + + + align:start position:0% +say take off and do pattern work at +their home Airport in some kind of + + align:start position:0% +their home Airport in some kind of + + + align:start position:0% +their home Airport in some kind of +little tiny very slow airplane pattern + + align:start position:0% +little tiny very slow airplane pattern + + + align:start position:0% +little tiny very slow airplane pattern +work is just what we were drying on the + + align:start position:0% +work is just what we were drying on the + + + align:start position:0% +work is just what we were drying on the +chalk board flying the traffic pattern + + align:start position:0% +chalk board flying the traffic pattern + + + align:start position:0% +chalk board flying the traffic pattern +at an airport + + align:start position:0% +at an airport + + + align:start position:0% +at an airport +so again yeah just review the + + align:start position:0% +so again yeah just review the + + + align:start position:0% +so again yeah just review the +presentation or the fa book so you know + + align:start position:0% +presentation or the fa book so you know + + + align:start position:0% +presentation or the fa book so you know +your weather minimums + + align:start position:0% +your weather minimums + + + align:start position:0% +your weather minimums +yeah incredibly at night for class G + + align:start position:0% +yeah incredibly at night for class G + + + align:start position:0% +yeah incredibly at night for class G +getting back to that pattern work thing + + align:start position:0% +getting back to that pattern work thing + + + align:start position:0% +getting back to that pattern work thing +if you want to go out and practice + + align:start position:0% +if you want to go out and practice + + + align:start position:0% +if you want to go out and practice +takeoffs and landings at night if you + + align:start position:0% +takeoffs and landings at night if you + + + align:start position:0% +takeoffs and landings at night if you +stay within half a mile of the runway + + align:start position:0% +stay within half a mile of the runway + + + align:start position:0% +stay within half a mile of the runway +you can go right down to one mile of + + align:start position:0% +you can go right down to one mile of + + + align:start position:0% +you can go right down to one mile of +visibility and right off right up to the + + align:start position:0% +visibility and right off right up to the + + + align:start position:0% +visibility and right off right up to the +clouds + + align:start position:0% +clouds + + + align:start position:0% +clouds +okay here's that chart again learn it + + align:start position:0% +okay here's that chart again learn it + + + align:start position:0% +okay here's that chart again learn it +know it special VFR actually if you're + + align:start position:0% +know it special VFR actually if you're + + + align:start position:0% +know it special VFR actually if you're +at Hanscom and the weather is below the + + align:start position:0% +at Hanscom and the weather is below the + + + align:start position:0% +at Hanscom and the weather is below the +basic minimums and you say you want to + + align:start position:0% +basic minimums and you say you want to + + + align:start position:0% +basic minimums and you say you want to +do some pattern work anyway either in a + + align:start position:0% +do some pattern work anyway either in a + + + align:start position:0% +do some pattern work anyway either in a +helicopter or an airplane you can + + align:start position:0% +helicopter or an airplane you can + + + align:start position:0% +helicopter or an airplane you can +request they can't offer it but you can + + align:start position:0% +request they can't offer it but you can + + + align:start position:0% +request they can't offer it but you can +request a special VFR clearance and + + align:start position:0% +request a special VFR clearance and + + + align:start position:0% +request a special VFR clearance and +they'll say okay there's not too much + + align:start position:0% +they'll say okay there's not too much + + + align:start position:0% +they'll say okay there's not too much +higher traffic right now so you you know + + align:start position:0% +higher traffic right now so you you know + + + align:start position:0% +higher traffic right now so you you know +take off and land and do your do your + + align:start position:0% +take off and land and do your do your + + + align:start position:0% +take off and land and do your do your +stuff if it's a night you'll have to be + + align:start position:0% +stuff if it's a night you'll have to be + + + align:start position:0% +stuff if it's a night you'll have to be +an IFR pilot basically cirrus publishes + + align:start position:0% +an IFR pilot basically cirrus publishes + + + align:start position:0% +an IFR pilot basically cirrus publishes +this good personal minimum matrix I + + align:start position:0% +this good personal minimum matrix I + + + align:start position:0% +this good personal minimum matrix I +wouldn't say that you have to adopt + + align:start position:0% +wouldn't say that you have to adopt + + + align:start position:0% +wouldn't say that you have to adopt +their specific numbers but I think their + + align:start position:0% +their specific numbers but I think their + + + align:start position:0% +their specific numbers but I think their +way of thinking isn't bad so notice + + align:start position:0% +way of thinking isn't bad so notice + + + align:start position:0% +way of thinking isn't bad so notice +they're saying you know if you are let's + + align:start position:0% +they're saying you know if you are let's + + + align:start position:0% +they're saying you know if you are let's +see an average pilot so you've got you + + align:start position:0% +see an average pilot so you've got you + + + align:start position:0% +see an average pilot so you've got you +know ten IFR hours within the last 90 + + align:start position:0% +know ten IFR hours within the last 90 + + + align:start position:0% +know ten IFR hours within the last 90 +days you've done you know one not on out + + align:start position:0% +days you've done you know one not on out + + + align:start position:0% +days you've done you know one not on out +of it approach within the last 90 days + + align:start position:0% +of it approach within the last 90 days + + + align:start position:0% +of it approach within the last 90 days +I'll go over here and go down to a 500 + + align:start position:0% +I'll go over here and go down to a 500 + + + align:start position:0% +I'll go over here and go down to a 500 +foot ceiling in two miles of visibility + + align:start position:0% +foot ceiling in two miles of visibility + + + align:start position:0% +foot ceiling in two miles of visibility +don't go down to the published approach + + align:start position:0% +don't go down to the published approach + + + align:start position:0% +don't go down to the published approach +minimums which are designed for a two + + align:start position:0% +minimums which are designed for a two + + + align:start position:0% +minimums which are designed for a two +pilot professional crew unless you know + + align:start position:0% +pilot professional crew unless you know + + + align:start position:0% +pilot professional crew unless you know +you're very current you've done a whole + + align:start position:0% +you're very current you've done a whole + + + align:start position:0% +you're very current you've done a whole +bunch of flying in the last 90 days + + align:start position:0% +bunch of flying in the last 90 days + + + align:start position:0% +bunch of flying in the last 90 days +anyway so they just try to fit they try + + align:start position:0% +anyway so they just try to fit they try + + + align:start position:0% +anyway so they just try to fit they try +to say how challenging is this like how + + align:start position:0% +to say how challenging is this like how + + + align:start position:0% +to say how challenging is this like how +experienced are you in general how + + align:start position:0% +experienced are you in general how + + + align:start position:0% +experienced are you in general how +experienced are you recently and come up + + align:start position:0% +experienced are you recently and come up + + + align:start position:0% +experienced are you recently and come up +with some numbers so again you can pull + + align:start position:0% +with some numbers so again you can pull + + + align:start position:0% +with some numbers so again you can pull +this out of the slide and just to + + align:start position:0% +this out of the slide and just to + + + align:start position:0% +this out of the slide and just to +clarify what we're talking about when we + + align:start position:0% +clarify what we're talking about when we + + + align:start position:0% +clarify what we're talking about when we +talk about personal minimums so there + + align:start position:0% +talk about personal minimums so there + + + align:start position:0% +talk about personal minimums so there +there are minimums that you have to know + + align:start position:0% +there are minimums that you have to know + + + align:start position:0% +there are minimums that you have to know +for the FAA exam like we were just + + align:start position:0% +for the FAA exam like we were just + + + align:start position:0% +for the FAA exam like we were just +talking about in terms of the minimum + + align:start position:0% +talking about in terms of the minimum + + + align:start position:0% +talking about in terms of the minimum +visibility that must be + + align:start position:0% +visibility that must be + + + align:start position:0% +visibility that must be +there in order to for you to fly in + + align:start position:0% +there in order to for you to fly in + + + align:start position:0% +there in order to for you to fly in +certain classes of airspace but then + + align:start position:0% +certain classes of airspace but then + + + align:start position:0% +certain classes of airspace but then +there are also minimums that you set on + + align:start position:0% +there are also minimums that you set on + + + align:start position:0% +there are also minimums that you set on +yourself to be a safe pilot and to be + + align:start position:0% +yourself to be a safe pilot and to be + + + align:start position:0% +yourself to be a safe pilot and to be +kind of knowledgeable about what your + + align:start position:0% +kind of knowledgeable about what your + + + align:start position:0% +kind of knowledgeable about what your +restrictions and what your experience + + align:start position:0% +restrictions and what your experience + + + align:start position:0% +restrictions and what your experience +and what your currency is so for example + + align:start position:0% +and what your currency is so for example + + + align:start position:0% +and what your currency is so for example +we talked about crosswind so there isn't + + align:start position:0% +we talked about crosswind so there isn't + + + align:start position:0% +we talked about crosswind so there isn't +an FA reg necessarily you know as long + + align:start position:0% +an FA reg necessarily you know as long + + + align:start position:0% +an FA reg necessarily you know as long +as it's within your aircraft's operating + + align:start position:0% +as it's within your aircraft's operating + + + align:start position:0% +as it's within your aircraft's operating +conditions there's no specific reason + + align:start position:0% +conditions there's no specific reason + + + align:start position:0% +conditions there's no specific reason +why you know a 15 or 20 knot crosswind + + align:start position:0% +why you know a 15 or 20 knot crosswind + + + align:start position:0% +why you know a 15 or 20 knot crosswind +is a problem but maybe you're not very + + align:start position:0% +is a problem but maybe you're not very + + + align:start position:0% +is a problem but maybe you're not very +comfortable with it you haven't done a + + align:start position:0% +comfortable with it you haven't done a + + + align:start position:0% +comfortable with it you haven't done a +lot of slips recently you're still + + align:start position:0% +lot of slips recently you're still + + + align:start position:0% +lot of slips recently you're still +getting used to your aircraft so you + + align:start position:0% +getting used to your aircraft so you + + + align:start position:0% +getting used to your aircraft so you +might say you know a smaller crosswind + + align:start position:0% +might say you know a smaller crosswind + + + align:start position:0% +might say you know a smaller crosswind +or gusting winds would be appropriate + + align:start position:0% +or gusting winds would be appropriate + + + align:start position:0% +or gusting winds would be appropriate +for you to land it so that's setting a + + align:start position:0% +for you to land it so that's setting a + + + align:start position:0% +for you to land it so that's setting a +personal minimum on yourself and this + + align:start position:0% +personal minimum on yourself and this + + + align:start position:0% +personal minimum on yourself and this +this is an example of personal minimums + + align:start position:0% +this is an example of personal minimums + + + align:start position:0% +this is an example of personal minimums +based on your experience and your + + align:start position:0% +based on your experience and your + + + align:start position:0% +based on your experience and your +currency and the FAA will never suggest + + align:start position:0% +currency and the FAA will never suggest + + + align:start position:0% +currency and the FAA will never suggest +this but the appropriate escape from you + + align:start position:0% +this but the appropriate escape from you + + + align:start position:0% +this but the appropriate escape from you +know a challenging situation that you + + align:start position:0% +know a challenging situation that you + + + align:start position:0% +know a challenging situation that you +think might be on the edge of safety is + + align:start position:0% +think might be on the edge of safety is + + + align:start position:0% +think might be on the edge of safety is +to rent the five-seat sr22 instead of + + align:start position:0% +to rent the five-seat sr22 instead of + + + align:start position:0% +to rent the five-seat sr22 instead of +the forc'd sr20 and go with an + + align:start position:0% +the forc'd sr20 and go with an + + + align:start position:0% +the forc'd sr20 and go with an +instructor so it's as easy as that + + align:start position:0% +instructor so it's as easy as that + + + align:start position:0% +instructor so it's as easy as that +ok remember this was confusing they use + + align:start position:0% +ok remember this was confusing they use + + + align:start position:0% +ok remember this was confusing they use +category in class to mean totally two + + align:start position:0% +category in class to mean totally two + + + align:start position:0% +category in class to mean totally two +totally different things for getting + + align:start position:0% +totally different things for getting + + + align:start position:0% +totally different things for getting +your pilot's certificate the category is + + align:start position:0% +your pilot's certificate the category is + + + align:start position:0% +your pilot's certificate the category is +there on the left something like an + + align:start position:0% +there on the left something like an + + + align:start position:0% +there on the left something like an +airplane versus a rotorcraft + + align:start position:0% +airplane versus a rotorcraft + + + align:start position:0% +airplane versus a rotorcraft +and the class would be you know multi + + align:start position:0% +and the class would be you know multi + + + align:start position:0% +and the class would be you know multi +engine land versus helicopter category + + align:start position:0% +engine land versus helicopter category + + + align:start position:0% +engine land versus helicopter category +class but then for aircraft they do + + align:start position:0% +class but then for aircraft they do + + + align:start position:0% +class but then for aircraft they do +something totally different and they say + + align:start position:0% +something totally different and they say + + + align:start position:0% +something totally different and they say +category would be you know normal + + align:start position:0% +category would be you know normal + + + align:start position:0% +category would be you know normal +category or acrobatic and class would be + + align:start position:0% +category or acrobatic and class would be + + + align:start position:0% +category or acrobatic and class would be +airplane so they may ask you about this + + align:start position:0% +airplane so they may ask you about this + + + align:start position:0% +airplane so they may ask you about this +just because they like the torque for + + align:start position:0% +just because they like the torque for + + + align:start position:0% +just because they like the torque for +you the four forces of flight remember + + align:start position:0% +you the four forces of flight remember + + + align:start position:0% +you the four forces of flight remember +these Tina talked about them if you're + + align:start position:0% +these Tina talked about them if you're + + + align:start position:0% +these Tina talked about them if you're +just bombing along straight and level + + align:start position:0% +just bombing along straight and level + + + align:start position:0% +just bombing along straight and level +not accelerating then they're gonna all + + align:start position:0% +not accelerating then they're gonna all + + + align:start position:0% +not accelerating then they're gonna all +be in balance because F equals MA + + align:start position:0% +be in balance because F equals MA + + + align:start position:0% +be in balance because F equals MA +equals whatever get remembers math + + align:start position:0% +equals whatever get remembers math + + + align:start position:0% +equals whatever get remembers math +anyway F equals MA I know that much + + align:start position:0% +anyway F equals MA I know that much + + + align:start position:0% +anyway F equals MA I know that much +remember the three axes they'll ask you + + align:start position:0% +remember the three axes they'll ask you + + + align:start position:0% +remember the three axes they'll ask you +about this on the test usually in + + align:start position:0% +about this on the test usually in + + + align:start position:0% +about this on the test usually in +combination with some other stuff so + + align:start position:0% +combination with some other stuff so + + + align:start position:0% +combination with some other stuff so +rotation about the vertical axis is + + align:start position:0% +rotation about the vertical axis is + + + align:start position:0% +rotation about the vertical axis is +going to be yaw rotation about the this + + align:start position:0% +going to be yaw rotation about the this + + + align:start position:0% +going to be yaw rotation about the this +is complicated let's see rotation about + + align:start position:0% +is complicated let's see rotation about + + + align:start position:0% +is complicated let's see rotation about +the lateral axis is going to be pitch + + align:start position:0% +the lateral axis is going to be pitch + + + align:start position:0% +the lateral axis is going to be pitch +rotation around the longitudinal axis I + + align:start position:0% +rotation around the longitudinal axis I + + + align:start position:0% +rotation around the longitudinal axis I +believe will be roll so that's a little + + align:start position:0% +believe will be roll so that's a little + + + align:start position:0% +believe will be roll so that's a little +bit confusing since yeah here we have it + + align:start position:0% +bit confusing since yeah here we have it + + + align:start position:0% +bit confusing since yeah here we have it +pitch roll yaw right so think about it + + align:start position:0% +pitch roll yaw right so think about it + + + align:start position:0% +pitch roll yaw right so think about it +roll is really the lateral motion but + + align:start position:0% +roll is really the lateral motion but + + + align:start position:0% +roll is really the lateral motion but +it's around the longitudinal axis so + + align:start position:0% +it's around the longitudinal axis so + + + align:start position:0% +it's around the longitudinal axis so +don't get confused there remember why + + align:start position:0% +don't get confused there remember why + + + align:start position:0% +don't get confused there remember why +Johnny Cessna can't hover is also a + + align:start position:0% +Johnny Cessna can't hover is also a + + + align:start position:0% +Johnny Cessna can't hover is also a +limit for this is this limits everything + + align:start position:0% +limit for this is this limits everything + + + align:start position:0% +limit for this is this limits everything +basically the stalling angle of attack + + align:start position:0% +basically the stalling angle of attack + + + align:start position:0% +basically the stalling angle of attack +is why you need a helicopter if you want + + align:start position:0% +is why you need a helicopter if you want + + + align:start position:0% +is why you need a helicopter if you want +to hover and it is why you need to + + align:start position:0% +to hover and it is why you need to + + + align:start position:0% +to hover and it is why you need to +maintain a reasonable airspeed when + + align:start position:0% +maintain a reasonable airspeed when + + + align:start position:0% +maintain a reasonable airspeed when +you're a landing and it's also it limits + + align:start position:0% +you're a landing and it's also it limits + + + align:start position:0% +you're a landing and it's also it limits +your runway right if you had an airplane + + align:start position:0% +your runway right if you had an airplane + + + align:start position:0% +your runway right if you had an airplane +that didn't stall till it reached some + + align:start position:0% +that didn't stall till it reached some + + + align:start position:0% +that didn't stall till it reached some +crazy angle attack you could probably + + align:start position:0% +crazy angle attack you could probably + + + align:start position:0% +crazy angle attack you could probably +take off and land in 50 feet right and + + align:start position:0% +take off and land in 50 feet right and + + + align:start position:0% +take off and land in 50 feet right and +remember that we talked about even a + + align:start position:0% +remember that we talked about even a + + + align:start position:0% +remember that we talked about even a +paper airplane can generate lift so it's + + align:start position:0% +paper airplane can generate lift so it's + + + align:start position:0% +paper airplane can generate lift so it's +not about the shape of the cross section + + align:start position:0% +not about the shape of the cross section + + + align:start position:0% +not about the shape of the cross section +of the wing that is making you be able + + align:start position:0% +of the wing that is making you be able + + + align:start position:0% +of the wing that is making you be able +to generate lift it's the angle of + + align:start position:0% +to generate lift it's the angle of + + + align:start position:0% +to generate lift it's the angle of +attack and your ability to deflect air + + align:start position:0% +attack and your ability to deflect air + + + align:start position:0% +attack and your ability to deflect air +molecules down that's what generates + + align:start position:0% +molecules down that's what generates + + + align:start position:0% +molecules down that's what generates +lift that shape of the airfoil is just + + align:start position:0% +lift that shape of the airfoil is just + + + align:start position:0% +lift that shape of the airfoil is just +what Philip was saying that allows you + + align:start position:0% +what Philip was saying that allows you + + + align:start position:0% +what Philip was saying that allows you +to have the stall speed be lowered all + + align:start position:0% +to have the stall speed be lowered all + + + align:start position:0% +to have the stall speed be lowered all +right so remember your left-turning + + align:start position:0% +right so remember your left-turning + + + align:start position:0% +right so remember your left-turning +tendencies mostly you just remember that + + align:start position:0% +tendencies mostly you just remember that + + + align:start position:0% +tendencies mostly you just remember that +you need right rudder and a couple + + align:start position:0% +you need right rudder and a couple + + + align:start position:0% +you need right rudder and a couple +questions had come up on gyroscopic + + align:start position:0% +questions had come up on gyroscopic + + + align:start position:0% +questions had come up on gyroscopic +precession so I added two videos about + + align:start position:0% +precession so I added two videos about + + + align:start position:0% +precession so I added two videos about +gyroscopes to help you understand + + align:start position:0% +gyroscopes to help you understand + + + align:start position:0% +gyroscopes to help you understand +gyroscopic precession and why that force + + align:start position:0% +gyroscopic precession and why that force + + + align:start position:0% +gyroscopic precession and why that force +is applied 90 degrees later and + + align:start position:0% +is applied 90 degrees later and + + + align:start position:0% +is applied 90 degrees later and +those are really fun videos you can look + + align:start position:0% +those are really fun videos you can look + + + align:start position:0% +those are really fun videos you can look +at their in the slide deck called QA and + + align:start position:0% +at their in the slide deck called QA and + + + align:start position:0% +at their in the slide deck called QA and +review ok so let's go back to the + + align:start position:0% +review ok so let's go back to the + + + align:start position:0% +review ok so let's go back to the +altitudes so true altitude is your + + align:start position:0% +altitudes so true altitude is your + + + align:start position:0% +altitudes so true altitude is your +actual height above sea level this is + + align:start position:0% +actual height above sea level this is + + + align:start position:0% +actual height above sea level this is +what's important if you want to get over + + align:start position:0% +what's important if you want to get over + + + align:start position:0% +what's important if you want to get over +on mountain because the altitude on the + + align:start position:0% +on mountain because the altitude on the + + + align:start position:0% +on mountain because the altitude on the +chart for the mountain is also the + + align:start position:0% +chart for the mountain is also the + + + align:start position:0% +chart for the mountain is also the +actual height above sea level indicated + + align:start position:0% +actual height above sea level indicated + + + align:start position:0% +actual height above sea level indicated +it's what your L Timoner shows if you're + + align:start position:0% +it's what your L Timoner shows if you're + + + align:start position:0% +it's what your L Timoner shows if you're +below 18,000 feet and it's not some + + align:start position:0% +below 18,000 feet and it's not some + + + align:start position:0% +below 18,000 feet and it's not some +insane temperature and you've got a + + align:start position:0% +insane temperature and you've got a + + + align:start position:0% +insane temperature and you've got a +current altimeter setting from air + + align:start position:0% +current altimeter setting from air + + + align:start position:0% +current altimeter setting from air +traffic control as you fly along with + + align:start position:0% +traffic control as you fly along with + + + align:start position:0% +traffic control as you fly along with +VFR advisories they'll keep updating you + + align:start position:0% +VFR advisories they'll keep updating you + + + align:start position:0% +VFR advisories they'll keep updating you +with altitudes if you're not talking to + + align:start position:0% +with altitudes if you're not talking to + + + align:start position:0% +with altitudes if you're not talking to +ATC you know you may to nin to the + + align:start position:0% +ATC you know you may to nin to the + + + align:start position:0% +ATC you know you may to nin to the +airports that you're flying over to get + + align:start position:0% +airports that you're flying over to get + + + align:start position:0% +airports that you're flying over to get +the altimeter there if you have your + + align:start position:0% +the altimeter there if you have your + + + align:start position:0% +the altimeter there if you have your +correctly set altimeter it should be + + align:start position:0% +correctly set altimeter it should be + + + align:start position:0% +correctly set altimeter it should be +pretty close to your true altitude but + + align:start position:0% +pretty close to your true altitude but + + + align:start position:0% +pretty close to your true altitude but +and the GPS will give it to you as well + + align:start position:0% +and the GPS will give it to you as well + + + align:start position:0% +and the GPS will give it to you as well +all right absolute height above the + + align:start position:0% +all right absolute height above the + + + align:start position:0% +all right absolute height above the +ground I don't think that's ever really + + align:start position:0% +ground I don't think that's ever really + + + align:start position:0% +ground I don't think that's ever really +relevant pressure altitude is what you + + align:start position:0% +relevant pressure altitude is what you + + + align:start position:0% +relevant pressure altitude is what you +see if you tune your altimeter to to + + align:start position:0% +see if you tune your altimeter to to + + + align:start position:0% +see if you tune your altimeter to to +nine or nine or two density is critical + + align:start position:0% +nine or nine or two density is critical + + + align:start position:0% +nine or nine or two density is critical +for determining performance of both the + + align:start position:0% +for determining performance of both the + + + align:start position:0% +for determining performance of both the +aircraft in the engine so that's a + + align:start position:0% +aircraft in the engine so that's a + + + align:start position:0% +aircraft in the engine so that's a +measure of you know how many actual + + align:start position:0% +measure of you know how many actual + + + align:start position:0% +measure of you know how many actual +molecules of air are there gonna be in a + + align:start position:0% +molecules of air are there gonna be in a + + + align:start position:0% +molecules of air are there gonna be in a +one liter cylinder for example know your + + align:start position:0% +one liter cylinder for example know your + + + align:start position:0% +one liter cylinder for example know your +taxiway and runway markings this has + + align:start position:0% +taxiway and runway markings this has + + + align:start position:0% +taxiway and runway markings this has +practical value and also test value one + + align:start position:0% +practical value and also test value one + + + align:start position:0% +practical value and also test value one +easy thing to remember is if you're + + align:start position:0% +easy thing to remember is if you're + + + align:start position:0% +easy thing to remember is if you're +driving along a taxiway in your aircraft + + align:start position:0% +driving along a taxiway in your aircraft + + + align:start position:0% +driving along a taxiway in your aircraft +you will see yellow paint on a black pay + + align:start position:0% +you will see yellow paint on a black pay + + + align:start position:0% +you will see yellow paint on a black pay +of surface so that sign tells you what + + align:start position:0% +of surface so that sign tells you what + + + align:start position:0% +of surface so that sign tells you what +taxiway that you're actually on just + + align:start position:0% +taxiway that you're actually on just + + + align:start position:0% +taxiway that you're actually on just +like the real-world experience of yellow + + align:start position:0% +like the real-world experience of yellow + + + align:start position:0% +like the real-world experience of yellow +paint on black everything else is kind + + align:start position:0% +paint on black everything else is kind + + + align:start position:0% +paint on black everything else is kind +of reasonably self-explanatory they + + align:start position:0% +of reasonably self-explanatory they + + + align:start position:0% +of reasonably self-explanatory they +probably even though if you're not an + + align:start position:0% +probably even though if you're not an + + + align:start position:0% +probably even though if you're not an +instrument pilot they want you to know + + align:start position:0% +instrument pilot they want you to know + + + align:start position:0% +instrument pilot they want you to know +about this ILS hold short line so if + + align:start position:0% +about this ILS hold short line so if + + + align:start position:0% +about this ILS hold short line so if +it's kind of bad weather conditions and + + align:start position:0% +it's kind of bad weather conditions and + + + align:start position:0% +it's kind of bad weather conditions and +they're using the ILS they don't want + + align:start position:0% +they're using the ILS they don't want + + + align:start position:0% +they're using the ILS they don't want +you going beyond there because your + + align:start position:0% +you going beyond there because your + + + align:start position:0% +you going beyond there because your +metal airplane might interfere with the + + align:start position:0% +metal airplane might interfere with the + + + align:start position:0% +metal airplane might interfere with the +radio beams that are being sent up + + align:start position:0% +radio beams that are being sent up + + + align:start position:0% +radio beams that are being sent up +- landing IFR airplanes remember L over + + align:start position:0% +- landing IFR airplanes remember L over + + + align:start position:0% +- landing IFR airplanes remember L over +D max for a best glide speed so all + + align:start position:0% +D max for a best glide speed so all + + + align:start position:0% +D max for a best glide speed so all +these climb speeds guides beads etc are + + align:start position:0% +these climb speeds guides beads etc are + + + align:start position:0% +these climb speeds guides beads etc are +driven off of the points at which the + + align:start position:0% +driven off of the points at which the + + + align:start position:0% +driven off of the points at which the +various drags reach a minimum or a + + align:start position:0% +various drags reach a minimum or a + + + align:start position:0% +various drags reach a minimum or a +minimum per per mile traveled + + align:start position:0% +minimum per per mile traveled + + + align:start position:0% +minimum per per mile traveled +thunderstorms + + align:start position:0% +thunderstorms + + + align:start position:0% +thunderstorms +the one thing you I hope you do remember + + align:start position:0% +the one thing you I hope you do remember + + + align:start position:0% +the one thing you I hope you do remember +is that everything is bad about + + align:start position:0% +is that everything is bad about + + + align:start position:0% +is that everything is bad about +convective clouds unstable air leads to + + align:start position:0% +convective clouds unstable air leads to + + + align:start position:0% +convective clouds unstable air leads to +cumulus clouds they can become + + align:start position:0% +cumulus clouds they can become + + + align:start position:0% +cumulus clouds they can become +cumulonimbus clouds and now you have a + + align:start position:0% +cumulonimbus clouds and now you have a + + + align:start position:0% +cumulonimbus clouds and now you have a +really bad hazard aviation with terrible + + align:start position:0% +really bad hazard aviation with terrible + + + align:start position:0% +really bad hazard aviation with terrible +icing terrible turbulence may be hail so + + align:start position:0% +icing terrible turbulence may be hail so + + + align:start position:0% +icing terrible turbulence may be hail so +the squall line I think they sometimes + + align:start position:0% +the squall line I think they sometimes + + + align:start position:0% +the squall line I think they sometimes +ask about this on the test the frontal + + align:start position:0% +ask about this on the test the frontal + + + align:start position:0% +ask about this on the test the frontal +band of thunderstorms so just you know + + align:start position:0% +band of thunderstorms so just you know + + + align:start position:0% +band of thunderstorms so just you know +it's hard to get around them and you + + align:start position:0% +it's hard to get around them and you + + + align:start position:0% +it's hard to get around them and you +know you may have to go 500 miles out of + + align:start position:0% +know you may have to go 500 miles out of + + + align:start position:0% +know you may have to go 500 miles out of +your way to get around the cold front or + + align:start position:0% +your way to get around the cold front or + + + align:start position:0% +your way to get around the cold front or +hang out on the ground for a few hours + + align:start position:0% +hang out on the ground for a few hours + + + align:start position:0% +hang out on the ground for a few hours +and wait for it to pass + + align:start position:0% +and wait for it to pass + + + align:start position:0% +and wait for it to pass +also just big changes in weather usually + + align:start position:0% +also just big changes in weather usually + + + align:start position:0% +also just big changes in weather usually +are not a good thing so whether it's a + + align:start position:0% +are not a good thing so whether it's a + + + align:start position:0% +are not a good thing so whether it's a +big change in the barometric pressure or + + align:start position:0% +big change in the barometric pressure or + + + align:start position:0% +big change in the barometric pressure or +as we saw from yesterday today to today + + align:start position:0% +as we saw from yesterday today to today + + + align:start position:0% +as we saw from yesterday today to today +like a 4050 degree increase in the + + align:start position:0% +like a 4050 degree increase in the + + + align:start position:0% +like a 4050 degree increase in the +temperature it's going to be accompanied + + align:start position:0% +temperature it's going to be accompanied + + + align:start position:0% +temperature it's going to be accompanied +by massive gusting winds today is not a + + align:start position:0% +by massive gusting winds today is not a + + + align:start position:0% +by massive gusting winds today is not a +good day to go flying yeah although + + align:start position:0% +good day to go flying yeah although + + + align:start position:0% +good day to go flying yeah although +actually it might not just be the day it + + align:start position:0% +actually it might not just be the day it + + + align:start position:0% +actually it might not just be the day it +might be you know now referring the + + align:start position:0% +might be you know now referring the + + + align:start position:0% +might be you know now referring the +helicopter from Los Angeles back to + + align:start position:0% +helicopter from Los Angeles back to + + + align:start position:0% +helicopter from Los Angeles back to +Boston and you know there was a + + align:start position:0% +Boston and you know there was a + + + align:start position:0% +Boston and you know there was a +thunderstorm coming in so we just landed + + align:start position:0% +thunderstorm coming in so we just landed + + + align:start position:0% +thunderstorm coming in so we just landed +in an airport it was probably gusting + + align:start position:0% +in an airport it was probably gusting + + + align:start position:0% +in an airport it was probably gusting +about 30 knots at the time which isn't + + align:start position:0% +about 30 knots at the time which isn't + + + align:start position:0% +about 30 knots at the time which isn't +that bad for Robinson the four-seat + + align:start position:0% +that bad for Robinson the four-seat + + + align:start position:0% +that bad for Robinson the four-seat +Robinson but the helicopter and a hangar + + align:start position:0% +Robinson but the helicopter and a hangar + + + align:start position:0% +Robinson but the helicopter and a hangar +you know there's a huge storm and the + + align:start position:0% +you know there's a huge storm and the + + + align:start position:0% +you know there's a huge storm and the +two hours later later we took off in + + align:start position:0% +two hours later later we took off in + + + align:start position:0% +two hours later later we took off in +beautiful weather and continued our + + align:start position:0% +beautiful weather and continued our + + + align:start position:0% +beautiful weather and continued our +flight so don't you know there is an + + align:start position:0% +flight so don't you know there is an + + + align:start position:0% +flight so don't you know there is an +airport usually every 10 or 15 minutes + + align:start position:0% +airport usually every 10 or 15 minutes + + + align:start position:0% +airport usually every 10 or 15 minutes +of flight time so take advantage of that + + align:start position:0% +of flight time so take advantage of that + + + align:start position:0% +of flight time so take advantage of that +if things are getting beyond your + + align:start position:0% +if things are getting beyond your + + + align:start position:0% +if things are getting beyond your +comfort zone don't just blindly continue + + align:start position:0% +comfort zone don't just blindly continue + + + align:start position:0% +comfort zone don't just blindly continue +to your destination so remember the lee + + align:start position:0% +to your destination so remember the lee + + + align:start position:0% +to your destination so remember the lee +side of mountains is where you can get a + + align:start position:0% +side of mountains is where you can get a + + + align:start position:0% +side of mountains is where you can get a +lot of turbulence and downdrafts a + + align:start position:0% +lot of turbulence and downdrafts a + + + align:start position:0% +lot of turbulence and downdrafts a +little airplane doesn't have a whole lot + + align:start position:0% +little airplane doesn't have a whole lot + + + align:start position:0% +little airplane doesn't have a whole lot +of kind performance usually especially + + align:start position:0% +of kind performance usually especially + + + align:start position:0% +of kind performance usually especially +up in higher altitudes + + align:start position:0% +up in higher altitudes + + + align:start position:0% +up in higher altitudes +so be cautious about crossing big + + align:start position:0% +so be cautious about crossing big + + + align:start position:0% +so be cautious about crossing big +mountain ranges unless the winds law + + align:start position:0% +mountain ranges unless the winds law + + + align:start position:0% +mountain ranges unless the winds law +forecast is for very light winds indeed + + align:start position:0% +forecast is for very light winds indeed + + + align:start position:0% +forecast is for very light winds indeed +icing also super bad again as the VFR + + align:start position:0% +icing also super bad again as the VFR + + + align:start position:0% +icing also super bad again as the VFR +pilots you shouldn't have to worry about + + align:start position:0% +pilots you shouldn't have to worry about + + + align:start position:0% +pilots you shouldn't have to worry about +this once you get into instrument flying + + align:start position:0% +this once you get into instrument flying + + + align:start position:0% +this once you get into instrument flying +that's a help a lot of you will this is + + align:start position:0% +that's a help a lot of you will this is + + + align:start position:0% +that's a help a lot of you will this is +really what limits your ability to + + align:start position:0% +really what limits your ability to + + + align:start position:0% +really what limits your ability to +travel around in a piper Cessna or + + align:start position:0% +travel around in a piper Cessna or + + + align:start position:0% +travel around in a piper Cessna or +Cirrus during the winter and shoulder + + align:start position:0% +Cirrus during the winter and shoulder + + + align:start position:0% +Cirrus during the winter and shoulder +seasons remember how to read the meats + + align:start position:0% +seasons remember how to read the meats + + + align:start position:0% +seasons remember how to read the meats +are so this is back to Peachtree DeKalb + + align:start position:0% +are so this is back to Peachtree DeKalb + + + align:start position:0% +are so this is back to Peachtree DeKalb +Airport in Atlanta so there's it's the + + align:start position:0% +Airport in Atlanta so there's it's the + + + align:start position:0% +Airport in Atlanta so there's it's the +16th at 16 53 so about almost 5 p.m. in + + align:start position:0% +16th at 16 53 so about almost 5 p.m. in + + + align:start position:0% +16th at 16 53 so about almost 5 p.m. in +London Zulu time winds are variable at + + align:start position:0% +London Zulu time winds are variable at + + + align:start position:0% +London Zulu time winds are variable at +410 statute miles of visibility overcast + + align:start position:0% +410 statute miles of visibility overcast + + + align:start position:0% +410 statute miles of visibility overcast +6000 feet that's 6,000 feet above the + + align:start position:0% +6000 feet that's 6,000 feet above the + + + align:start position:0% +6000 feet that's 6,000 feet above the +airport not above sea level + + align:start position:0% +airport not above sea level + + + align:start position:0% +airport not above sea level +temps 14 dew points -7 altimeter three + + align:start position:0% +temps 14 dew points -7 altimeter three + + + align:start position:0% +temps 14 dew points -7 altimeter three +zero one five oh and in the remarks it + + align:start position:0% +zero one five oh and in the remarks it + + + align:start position:0% +zero one five oh and in the remarks it +says the rain ended 46 minutes after the + + align:start position:0% +says the rain ended 46 minutes after the + + + align:start position:0% +says the rain ended 46 minutes after the +hour there you have it + + align:start position:0% +hour there you have it + + + align:start position:0% +hour there you have it +alright human factor summary so you are + + align:start position:0% +alright human factor summary so you are + + + align:start position:0% +alright human factor summary so you are +the weakest link and if you develop some + + align:start position:0% +the weakest link and if you develop some + + + align:start position:0% +the weakest link and if you develop some +personal minimums you'll be way ahead of + + align:start position:0% +personal minimums you'll be way ahead of + + + align:start position:0% +personal minimums you'll be way ahead of +the game + + align:start position:0% +the game + + + align:start position:0% +the game +they should also factor in your recent + + align:start position:0% +they should also factor in your recent + + + align:start position:0% +they should also factor in your recent +experience not just your overall level + + align:start position:0% +experience not just your overall level + + + align:start position:0% +experience not just your overall level +of flying and always remember that it's + + align:start position:0% +of flying and always remember that it's + + + align:start position:0% +of flying and always remember that it's +a big aviation community there's a lot + + align:start position:0% +a big aviation community there's a lot + + + align:start position:0% +a big aviation community there's a lot +of people are happy to go flying + + align:start position:0% +of people are happy to go flying + + + align:start position:0% +of people are happy to go flying +you can send mail to the members of the + + align:start position:0% +you can send mail to the members of the + + + align:start position:0% +you can send mail to the members of the +MIT Flying Club and just take a copilot + + align:start position:0% +MIT Flying Club and just take a copilot + + + align:start position:0% +MIT Flying Club and just take a copilot +that's how the airlines have cut risk + + align:start position:0% +that's how the airlines have cut risk + + + align:start position:0% +that's how the airlines have cut risk +almost to zero magnetic variation this + + align:start position:0% +almost to zero magnetic variation this + + + align:start position:0% +almost to zero magnetic variation this +is kind of a topic that tends to snag + + align:start position:0% +is kind of a topic that tends to snag + + + align:start position:0% +is kind of a topic that tends to snag +people on the knowledge test so just + + align:start position:0% +people on the knowledge test so just + + + align:start position:0% +people on the knowledge test so just +remember you can read arrived it from + + align:start position:0% +remember you can read arrived it from + + + align:start position:0% +remember you can read arrived it from +the vor if you ever get stuck and East + + align:start position:0% +the vor if you ever get stuck and East + + + align:start position:0% +the vor if you ever get stuck and East +is leased West is best deviation then + + align:start position:0% +is leased West is best deviation then + + + align:start position:0% +is leased West is best deviation then +don't don't get deviation and variation + + align:start position:0% +don't don't get deviation and variation + + + align:start position:0% +don't don't get deviation and variation +confused so deviation remember + + align:start position:0% +confused so deviation remember + + + align:start position:0% +confused so deviation remember +is that tiny little correction that's + + align:start position:0% +is that tiny little correction that's + + + align:start position:0% +is that tiny little correction that's +printed right underneath the compass + + align:start position:0% +printed right underneath the compass + + + align:start position:0% +printed right underneath the compass +flight planning tip you saw this slide + + align:start position:0% +flight planning tip you saw this slide + + + align:start position:0% +flight planning tip you saw this slide +earlier even the far 61 and far 91 allow + + align:start position:0% +earlier even the far 61 and far 91 allow + + + align:start position:0% +earlier even the far 61 and far 91 allow +it and doesn't mean it's wise so if you + + align:start position:0% +it and doesn't mean it's wise so if you + + + align:start position:0% +it and doesn't mean it's wise so if you +look at far 121 and far 135 for charter + + align:start position:0% +look at far 121 and far 135 for charter + + + align:start position:0% +look at far 121 and far 135 for charter +and scheduled airline service they show + + align:start position:0% +and scheduled airline service they show + + + align:start position:0% +and scheduled airline service they show +you that there's some extra safety + + align:start position:0% +you that there's some extra safety + + + align:start position:0% +you that there's some extra safety +margins that can be built in night + + align:start position:0% +margins that can be built in night + + + align:start position:0% +margins that can be built in night +flying advice you just heard remember is + + align:start position:0% +flying advice you just heard remember is + + + align:start position:0% +flying advice you just heard remember is +the owner/operator you're responsible + + align:start position:0% +the owner/operator you're responsible + + + align:start position:0% +the owner/operator you're responsible +for keeping the airplane air worthy if + + align:start position:0% +for keeping the airplane air worthy if + + + align:start position:0% +for keeping the airplane air worthy if +you do choose to go out and buy an + + align:start position:0% +you do choose to go out and buy an + + + align:start position:0% +you do choose to go out and buy an +aircraft so these responsibilities are + + align:start position:0% +aircraft so these responsibilities are + + + align:start position:0% +aircraft so these responsibilities are +you know for most of you going to be on + + align:start position:0% +you know for most of you going to be on + + + align:start position:0% +you know for most of you going to be on +the flight school however you're still + + align:start position:0% +the flight school however you're still + + + align:start position:0% +the flight school however you're still +the final authority as the pilot and you + + align:start position:0% +the final authority as the pilot and you + + + align:start position:0% +the final authority as the pilot and you +can deviate from the rules in an + + align:start position:0% +can deviate from the rules in an + + + align:start position:0% +can deviate from the rules in an +emergency and you only have to report + + align:start position:0% +emergency and you only have to report + + + align:start position:0% +emergency and you only have to report +the deviation if requested I think that + + align:start position:0% +the deviation if requested I think that + + + align:start position:0% +the deviation if requested I think that +the feds like to ask this on the + + align:start position:0% +the feds like to ask this on the + + + align:start position:0% +the feds like to ask this on the +knowledge test because the natural + + align:start position:0% +knowledge test because the natural + + + align:start position:0% +knowledge test because the natural +answer is of course you have to report + + align:start position:0% +answer is of course you have to report + + + align:start position:0% +answer is of course you have to report +the deviation and I declared it an + + align:start position:0% +the deviation and I declared it an + + + align:start position:0% +the deviation and I declared it an +emergency and I broke the rules but you + + align:start position:0% +emergency and I broke the rules but you + + + align:start position:0% +emergency and I broke the rules but you +don't actually have to report that + + align:start position:0% +don't actually have to report that + + + align:start position:0% +don't actually have to report that +unless they ask you to but even aside + + align:start position:0% +unless they ask you to but even aside + + + align:start position:0% +unless they ask you to but even aside +from an emergency you're the pilot and + + align:start position:0% +from an emergency you're the pilot and + + + align:start position:0% +from an emergency you're the pilot and +command even if someone very assertively + + align:start position:0% +command even if someone very assertively + + + align:start position:0% +command even if someone very assertively +tells you to land and hold short or to + + align:start position:0% +tells you to land and hold short or to + + + align:start position:0% +tells you to land and hold short or to +fly straight to the numbers which means + + align:start position:0% +fly straight to the numbers which means + + + align:start position:0% +fly straight to the numbers which means +don't fly the profit proper traffic + + align:start position:0% +don't fly the profit proper traffic + + + align:start position:0% +don't fly the profit proper traffic +pattern but but land very quickly or + + align:start position:0% +pattern but but land very quickly or + + + align:start position:0% +pattern but but land very quickly or +tells you you know no delay on the go + + align:start position:0% +tells you you know no delay on the go + + + align:start position:0% +tells you you know no delay on the go +because they want you to get out quickly + + align:start position:0% +because they want you to get out quickly + + + align:start position:0% +because they want you to get out quickly +they have other jets + + align:start position:0% +they have other jets + + + align:start position:0% +they have other jets +you can just say unable and they have to + + align:start position:0% +you can just say unable and they have to + + + align:start position:0% +you can just say unable and they have to +deal with it and make sure you're flying + + align:start position:0% +deal with it and make sure you're flying + + + align:start position:0% +deal with it and make sure you're flying +safely and if you especially as a + + align:start position:0% +safely and if you especially as a + + + align:start position:0% +safely and if you especially as a +student pilot need extra time or extra + + align:start position:0% +student pilot need extra time or extra + + + align:start position:0% +student pilot need extra time or extra +consideration just add student pilot to + + align:start position:0% +consideration just add student pilot to + + + align:start position:0% +consideration just add student pilot to +the end of all your radio calls and + + align:start position:0% +the end of all your radio calls and + + + align:start position:0% +the end of all your radio calls and +they'll give you plenty of room to make + + align:start position:0% +they'll give you plenty of room to make + + + align:start position:0% +they'll give you plenty of room to make +mistakes but they might also make you + + align:start position:0% +mistakes but they might also make you + + + align:start position:0% +mistakes but they might also make you +sit there and fly a bunch of 360s while + + align:start position:0% +sit there and fly a bunch of 360s while + + + align:start position:0% +sit there and fly a bunch of 360s while +they land everybody else and then give + + align:start position:0% +they land everybody else and then give + + + align:start position:0% +they land everybody else and then give +you time and yeah so safety is not high + + align:start position:0% +you time and yeah so safety is not high + + + align:start position:0% +you time and yeah so safety is not high +tech it should be probably you know we + + align:start position:0% +tech it should be probably you know we + + + align:start position:0% +tech it should be probably you know we +should actually all the stuff that + + align:start position:0% +should actually all the stuff that + + + align:start position:0% +should actually all the stuff that +Michael showed you that's embedded in + + align:start position:0% +Michael showed you that's embedded in + + + align:start position:0% +Michael showed you that's embedded in +that DJI drone should probably be in + + align:start position:0% +that DJI drone should probably be in + + + align:start position:0% +that DJI drone should probably be in +these multi-million dollar aircraft but + + align:start position:0% +these multi-million dollar aircraft but + + + align:start position:0% +these multi-million dollar aircraft but +it's not so in the meantime + + align:start position:0% +it's not so in the meantime + + + align:start position:0% +it's not so in the meantime +you know since an airliner isn't + + align:start position:0% +you know since an airliner isn't + + + align:start position:0% +you know since an airliner isn't +actually that much smarter than a little + + align:start position:0% +actually that much smarter than a little + + + align:start position:0% +actually that much smarter than a little +Cessna you know why is it safer and if + + align:start position:0% +Cessna you know why is it safer and if + + + align:start position:0% +Cessna you know why is it safer and if +you take that perspective and just adapt + + align:start position:0% +you take that perspective and just adapt + + + align:start position:0% +you take that perspective and just adapt +all the things the airlines have done + + align:start position:0% +all the things the airlines have done + + + align:start position:0% +all the things the airlines have done +you can make flying that little Cessna + + align:start position:0% +you can make flying that little Cessna + + + align:start position:0% +you can make flying that little Cessna +dramatically safer + + align:start position:0% +dramatically safer + + + align:start position:0% +dramatically safer +so that means recurrent training you + + align:start position:0% +so that means recurrent training you + + + align:start position:0% +so that means recurrent training you +know maybe go up with an instructor + + align:start position:0% +know maybe go up with an instructor + + + align:start position:0% +know maybe go up with an instructor +every three months instead of the every + + align:start position:0% +every three months instead of the every + + + align:start position:0% +every three months instead of the every +two years that the FAA requires the + + align:start position:0% +two years that the FAA requires the + + + align:start position:0% +two years that the FAA requires the +instrument flying skills are really + + align:start position:0% +instrument flying skills are really + + + align:start position:0% +instrument flying skills are really +important for VFR safety they make you a + + align:start position:0% +important for VFR safety they make you a + + + align:start position:0% +important for VFR safety they make you a +much better pilot you know at night as + + align:start position:0% +much better pilot you know at night as + + + align:start position:0% +much better pilot you know at night as +we've just discussed and even bombing + + align:start position:0% +we've just discussed and even bombing + + + align:start position:0% +we've just discussed and even bombing +around during the day you'll be able to + + align:start position:0% +around during the day you'll be able to + + + align:start position:0% +around during the day you'll be able to +fly with about five percent of your + + align:start position:0% +fly with about five percent of your + + + align:start position:0% +fly with about five percent of your +mental energy instead of 50% if you are + + align:start position:0% +mental energy instead of 50% if you are + + + align:start position:0% +mental energy instead of 50% if you are +an instrument-rated pilot on a nice VFR + + align:start position:0% +an instrument-rated pilot on a nice VFR + + + align:start position:0% +an instrument-rated pilot on a nice VFR +day the two pilot crew and checklist is + + align:start position:0% +day the two pilot crew and checklist is + + + align:start position:0% +day the two pilot crew and checklist is +really the cornerstone of the airline + + align:start position:0% +really the cornerstone of the airline + + + align:start position:0% +really the cornerstone of the airline +safety system so and you can take + + align:start position:0% +safety system so and you can take + + + align:start position:0% +safety system so and you can take +advantage of that as a ga pilot even + + align:start position:0% +advantage of that as a ga pilot even + + + align:start position:0% +advantage of that as a ga pilot even +though the FA you know really about 5% + + align:start position:0% +though the FA you know really about 5% + + + align:start position:0% +though the FA you know really about 5% +of the FAA which is the one you've seen + + align:start position:0% +of the FAA which is the one you've seen + + + align:start position:0% +of the FAA which is the one you've seen +and interacted with it's all about + + align:start position:0% +and interacted with it's all about + + + align:start position:0% +and interacted with it's all about +encouraging people to be single pilots + + align:start position:0% +encouraging people to be single pilots + + + align:start position:0% +encouraging people to be single pilots +and 95% of the FAA is about forbidding + + align:start position:0% +and 95% of the FAA is about forbidding + + + align:start position:0% +and 95% of the FAA is about forbidding +people to operate single pilot every + + align:start position:0% +people to operate single pilot every + + + align:start position:0% +people to operate single pilot every +part of the FAA that regulates you know + + align:start position:0% +part of the FAA that regulates you know + + + align:start position:0% +part of the FAA that regulates you know +the airlines and charters of sizeable + + align:start position:0% +the airlines and charters of sizeable + + + align:start position:0% +the airlines and charters of sizeable +airplanes they say no of course you + + align:start position:0% +airplanes they say no of course you + + + align:start position:0% +airplanes they say no of course you +can't operate a single pilot that would + + align:start position:0% +can't operate a single pilot that would + + + align:start position:0% +can't operate a single pilot that would +be incredibly dangerous alright so just + + align:start position:0% +be incredibly dangerous alright so just + + + align:start position:0% +be incredibly dangerous alright so just +remember study a little bit about the + + align:start position:0% +remember study a little bit about the + + + align:start position:0% +remember study a little bit about the +part 61 and part 91 for learning - we + + align:start position:0% +part 61 and part 91 for learning - we + + + align:start position:0% +part 61 and part 91 for learning - we +know what does it take to be and + + align:start position:0% +know what does it take to be and + + + align:start position:0% +know what does it take to be and +maintain your status as a pilot or being + + align:start position:0% +maintain your status as a pilot or being + + + align:start position:0% +maintain your status as a pilot or being +able to exercise your privileges as a + + align:start position:0% +able to exercise your privileges as a + + + align:start position:0% +able to exercise your privileges as a +pilot that certificate never expires + + align:start position:0% +pilot that certificate never expires + + + align:start position:0% +pilot that certificate never expires +part 91 is about what you can do with an + + align:start position:0% +part 91 is about what you can do with an + + + align:start position:0% +part 91 is about what you can do with an +airplane operated privately and then + + align:start position:0% +airplane operated privately and then + + + align:start position:0% +airplane operated privately and then +there's this little corner over there + + align:start position:0% +there's this little corner over there + + + align:start position:0% +there's this little corner over there +under title 49 part 830 having to do + + align:start position:0% +under title 49 part 830 having to do + + + align:start position:0% +under title 49 part 830 having to do +with accident reporting and + + align:start position:0% +with accident reporting and + + + align:start position:0% +with accident reporting and +investigation if you want to get a + + align:start position:0% +investigation if you want to get a + + + align:start position:0% +investigation if you want to get a +hundred on the fa knowledge test a lot + + align:start position:0% +hundred on the fa knowledge test a lot + + + align:start position:0% +hundred on the fa knowledge test a lot +of East Coast Aero Club customers seem + + align:start position:0% +of East Coast Aero Club customers seem + + + align:start position:0% +of East Coast Aero Club customers seem +to over study I see a lot of 95 97 98 + + align:start position:0% +to over study I see a lot of 95 97 98 + + + align:start position:0% +to over study I see a lot of 95 97 98 +and 100's actual 100's just reread the + + align:start position:0% +and 100's actual 100's just reread the + + + align:start position:0% +and 100's actual 100's just reread the +FAA text + + align:start position:0% +FAA text + + + align:start position:0% +FAA text +I mean they can't ask you anything + + align:start position:0% +I mean they can't ask you anything + + + align:start position:0% +I mean they can't ask you anything +that's not in one of their own PDFs that + + align:start position:0% +that's not in one of their own PDFs that + + + align:start position:0% +that's not in one of their own PDFs that +includes the far aim though the the + + align:start position:0% +includes the far aim though the the + + + align:start position:0% +includes the far aim though the the +regulations and the aeronautical + + align:start position:0% +regulations and the aeronautical + + + align:start position:0% +regulations and the aeronautical +information manual there are test prep + + align:start position:0% +information manual there are test prep + + + align:start position:0% +information manual there are test prep +books and all nine equivalents that are + + align:start position:0% +books and all nine equivalents that are + + + align:start position:0% +books and all nine equivalents that are +worth it to finish this course actually + + align:start position:0% +worth it to finish this course actually + + + align:start position:0% +worth it to finish this course actually +you can get this you'll be able to get + + align:start position:0% +you can get this you'll be able to get + + + align:start position:0% +you can get this you'll be able to get +actually we don't even need to email you + + align:start position:0% +actually we don't even need to email you + + + align:start position:0% +actually we don't even need to email you +because if you have the course homepage + + align:start position:0% +because if you have the course homepage + + + align:start position:0% +because if you have the course homepage +you can see it here you go to this king + + align:start position:0% +you can see it here you go to this king + + + align:start position:0% +you can see it here you go to this king +school thing and you say you want to do + + align:start position:0% +school thing and you say you want to do + + + align:start position:0% +school thing and you say you want to do +60 questions 60 is a number of questions + + align:start position:0% +60 questions 60 is a number of questions + + + align:start position:0% +60 questions 60 is a number of questions +on the actual exam so we're making our + + align:start position:0% +on the actual exam so we're making our + + + align:start position:0% +on the actual exam so we're making our +final exam being the same and then you + + align:start position:0% +final exam being the same and then you + + + align:start position:0% +final exam being the same and then you +start test and you send us the results + + align:start position:0% + + + + align:start position:0% + +and we'll be happy + + align:start position:0% +and we'll be happy + + + align:start position:0% +and we'll be happy +all right next steps if you want to + + align:start position:0% +all right next steps if you want to + + + align:start position:0% +all right next steps if you want to +continue your journey beyond this class + + align:start position:0% +continue your journey beyond this class + + + align:start position:0% +continue your journey beyond this class +maybe that's for the one or two people + + align:start position:0% +maybe that's for the one or two people + + + align:start position:0% +maybe that's for the one or two people +that applies that actually want to + + align:start position:0% +that applies that actually want to + + + align:start position:0% +that applies that actually want to +continue their journey can I borrow the + + align:start position:0% +continue their journey can I borrow the + + + align:start position:0% +continue their journey can I borrow the +pointer for just a second this for the + + align:start position:0% +pointer for just a second this for the + + + align:start position:0% +pointer for just a second this for the +guys that we're getting tripped up + + align:start position:0% +guys that we're getting tripped up + + + align:start position:0% +guys that we're getting tripped up +thinking it was a river that's exactly + + align:start position:0% +thinking it was a river that's exactly + + + align:start position:0% +thinking it was a river that's exactly +what we're talking about this is a + + align:start position:0% +what we're talking about this is a + + + align:start position:0% +what we're talking about this is a +Boston Logan these blue lines circles + + align:start position:0% +Boston Logan these blue lines circles + + + align:start position:0% +Boston Logan these blue lines circles +that are rounded are not rivers it's + + align:start position:0% +that are rounded are not rivers it's + + + align:start position:0% +that are rounded are not rivers it's +indicating that class Bravo airspace and + + align:start position:0% +indicating that class Bravo airspace and + + + align:start position:0% +indicating that class Bravo airspace and +I have it open over here if you want to + + align:start position:0% +I have it open over here if you want to + + + align:start position:0% +I have it open over here if you want to +take a look okay so yeah join the flying + + align:start position:0% +take a look okay so yeah join the flying + + + align:start position:0% +take a look okay so yeah join the flying +club go visit a flight school most of + + align:start position:0% +club go visit a flight school most of + + + align:start position:0% +club go visit a flight school most of +the busier US airports have some kind of + + align:start position:0% +the busier US airports have some kind of + + + align:start position:0% +the busier US airports have some kind of +flight school that you can do and yeah + + align:start position:0% +flight school that you can do and yeah + + + align:start position:0% +flight school that you can do and yeah +in the two hours that are remaining to + + align:start position:0% +in the two hours that are remaining to + + + align:start position:0% +in the two hours that are remaining to +me for this presentation I would just + + align:start position:0% +me for this presentation I would just + + + align:start position:0% +me for this presentation I would just +like to say thank you now we're saying + + align:start position:0% +like to say thank you now we're saying + + + align:start position:0% +like to say thank you now we're saying +thank you but just to clarify there's + + align:start position:0% +thank you but just to clarify there's + + + align:start position:0% +thank you but just to clarify there's +there's a really cool guest speaker + + align:start position:0% +there's a really cool guest speaker + + + align:start position:0% +there's a really cool guest speaker +coming next but for the purposes of our + + align:start position:0% +coming next but for the purposes of our + + + align:start position:0% +coming next but for the purposes of our +teaching thank you very much and we'll + + align:start position:0% +teaching thank you very much and we'll + + + align:start position:0% +teaching thank you very much and we'll +take any questions + + align:start position:0% +take any questions + + + align:start position:0% +take any questions +you + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/kpUg96uZk2M.txt b/kpUg96uZk2M.txt new file mode 100644 index 0000000000000000000000000000000000000000..9861eb90ebf259df6c8d8fa1993e0ec877ad7450 --- /dev/null +++ b/kpUg96uZk2M.txt @@ -0,0 +1,7787 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit MIT opencourseware + + align:start position:0% +of MIT courses visit MIT opencourseware + + + align:start position:0% +of MIT courses visit MIT opencourseware +at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu so let's get started + + align:start position:0% + + + + align:start position:0% + +oh it's interesting that some of your + + align:start position:0% +oh it's interesting that some of your + + + align:start position:0% +oh it's interesting that some of your +questions had to do with things that I + + align:start position:0% +questions had to do with things that I + + + align:start position:0% +questions had to do with things that I +didn't quite cover in lecture but that's + + align:start position:0% +didn't quite cover in lecture but that's + + + align:start position:0% +didn't quite cover in lecture but that's +fine I'm going to cover them at the + + align:start position:0% +fine I'm going to cover them at the + + + align:start position:0% +fine I'm going to cover them at the +beginning of today's + + align:start position:0% + + + + align:start position:0% + +lecture this is a really important + + align:start position:0% +lecture this is a really important + + + align:start position:0% +lecture this is a really important +question how do you know what channel an + + align:start position:0% +question how do you know what channel an + + + align:start position:0% +question how do you know what channel an +is how do you know what I in a + + align:start position:0% +is how do you know what I in a + + + align:start position:0% +is how do you know what I in a +particular channel is + + align:start position:0% +particular channel is + + + align:start position:0% +particular channel is +conducting it's actually hard to + + align:start position:0% +conducting it's actually hard to + + + align:start position:0% +conducting it's actually hard to +determine they're very ious ways to do + + align:start position:0% +determine they're very ious ways to do + + + align:start position:0% +determine they're very ious ways to do +it where you can + + align:start position:0% +it where you can + + + align:start position:0% +it where you can +specifically um label the iron or follow + + align:start position:0% +specifically um label the iron or follow + + + align:start position:0% +specifically um label the iron or follow +a particular ion and address whether or + + align:start position:0% +a particular ion and address whether or + + + align:start position:0% +a particular ion and address whether or +not it's getting into a cell or across a + + align:start position:0% +not it's getting into a cell or across a + + + align:start position:0% +not it's getting into a cell or across a +membrane when there's a particular ION + + align:start position:0% +membrane when there's a particular ION + + + align:start position:0% +membrane when there's a particular ION +channel present but it's not completely + + align:start position:0% +channel present but it's not completely + + + align:start position:0% +channel present but it's not completely +trivial one of the things I didn't have + + align:start position:0% +trivial one of the things I didn't have + + + align:start position:0% +trivial one of the things I didn't have +time to go through with you but which is + + align:start position:0% +time to go through with you but which is + + + align:start position:0% +time to go through with you but which is +on one of the Powerpoints though is the + + align:start position:0% +on one of the Powerpoints though is the + + + align:start position:0% +on one of the Powerpoints though is the +fact that ion channels are really + + align:start position:0% +fact that ion channels are really + + + align:start position:0% +fact that ion channels are really +selective and they don't conduct ions on + + align:start position:0% +selective and they don't conduct ions on + + + align:start position:0% +selective and they don't conduct ions on +the base of size okay so you're not + + align:start position:0% +the base of size okay so you're not + + + align:start position:0% +the base of size okay so you're not +going to get a large ion CH channel that + + align:start position:0% +going to get a large ion CH channel that + + + align:start position:0% +going to get a large ion CH channel that +can accommodate a large ion also + + align:start position:0% +can accommodate a large ion also + + + align:start position:0% +can accommodate a large ion also +accommodating a small ion it's not a + + align:start position:0% +accommodating a small ion it's not a + + + align:start position:0% +accommodating a small ion it's not a +matter about of just opening up a space + + align:start position:0% +matter about of just opening up a space + + + align:start position:0% +matter about of just opening up a space +there are also charge considerations + + align:start position:0% +there are also charge considerations + + + align:start position:0% +there are also charge considerations +where the ions actually interact with + + align:start position:0% +where the ions actually interact with + + + align:start position:0% +where the ions actually interact with +the molecules in the channel in the + + align:start position:0% +the molecules in the channel in the + + + align:start position:0% +the molecules in the channel in the +actual pour through the membrane and + + align:start position:0% +actual pour through the membrane and + + + align:start position:0% +actual pour through the membrane and +it's that interaction which it selects + + align:start position:0% +it's that interaction which it selects + + + align:start position:0% +it's that interaction which it selects +for a particular ion but this notion of + + align:start position:0% +for a particular ion but this notion of + + + align:start position:0% +for a particular ion but this notion of +exactly what ions channels are + + align:start position:0% +exactly what ions channels are + + + align:start position:0% +exactly what ions channels are +conducting has been many many decades of + + align:start position:0% +conducting has been many many decades of + + + align:start position:0% +conducting has been many many decades of +work and what I've written up here is + + align:start position:0% +work and what I've written up here is + + + align:start position:0% +work and what I've written up here is +correct but if you want to explore it + + align:start position:0% +correct but if you want to explore it + + + align:start position:0% +correct but if you want to explore it +more with me come and talk during office + + align:start position:0% +more with me come and talk during office + + + align:start position:0% +more with me come and talk during office +hours and then a number of you started + + align:start position:0% +hours and then a number of you started + + + align:start position:0% +hours and then a number of you started +asking me about modulation of + + align:start position:0% +asking me about modulation of + + + align:start position:0% +asking me about modulation of +neurotransmitters which I'll talk about + + align:start position:0% +neurotransmitters which I'll talk about + + + align:start position:0% +neurotransmitters which I'll talk about +in today's lecture and these are clearly + + align:start position:0% +in today's lecture and these are clearly + + + align:start position:0% +in today's lecture and these are clearly +of interest because many recreational + + align:start position:0% +of interest because many recreational + + + align:start position:0% +of interest because many recreational +drugs and medications mod modulate + + align:start position:0% +drugs and medications mod modulate + + + align:start position:0% +drugs and medications mod modulate +neurotransmitter amounts and that is how + + align:start position:0% +neurotransmitter amounts and that is how + + + align:start position:0% +neurotransmitter amounts and that is how +they work so for example some of you + + align:start position:0% +they work so for example some of you + + + align:start position:0% +they work so for example some of you +might be taking things called SSRI + + align:start position:0% +might be taking things called SSRI + + + align:start position:0% +might be taking things called SSRI +specific serotonin reuptake Inhibitors + + align:start position:0% +specific serotonin reuptake Inhibitors + + + align:start position:0% +specific serotonin reuptake Inhibitors +like Prozac which make you feel less + + align:start position:0% +like Prozac which make you feel less + + + align:start position:0% +like Prozac which make you feel less +anxious and better about things and + + align:start position:0% +anxious and better about things and + + + align:start position:0% +anxious and better about things and +these act by prolonging serotonin + + align:start position:0% +these act by prolonging serotonin + + + align:start position:0% +these act by prolonging serotonin +activity by preventing it from being + + align:start position:0% +activity by preventing it from being + + + align:start position:0% +activity by preventing it from being +retaken up into cells and I'll touch on + + align:start position:0% +retaken up into cells and I'll touch on + + + align:start position:0% +retaken up into cells and I'll touch on +this at the beginning of the lecture and + + align:start position:0% +this at the beginning of the lecture and + + + align:start position:0% +this at the beginning of the lecture and +it takes a while is what I've written + + align:start position:0% +it takes a while is what I've written + + + align:start position:0% +it takes a while is what I've written +here for these medications to start + + align:start position:0% +here for these medications to start + + + align:start position:0% +here for these medications to start +working because you're really asking for + + align:start position:0% +working because you're really asking for + + + align:start position:0% +working because you're really asking for +a rearrangement of the whole synaptic + + align:start position:0% +a rearrangement of the whole synaptic + + + align:start position:0% +a rearrangement of the whole synaptic +process and the synaptic structure in + + align:start position:0% +process and the synaptic structure in + + + align:start position:0% +process and the synaptic structure in +order that they can work and here's + + align:start position:0% +order that they can work and here's + + + align:start position:0% +order that they can work and here's +another one what about amphetamines are + + align:start position:0% +another one what about amphetamines are + + + align:start position:0% +another one what about amphetamines are +they neurotransmitters no they they + + align:start position:0% +they neurotransmitters no they they + + + align:start position:0% +they neurotransmitters no they they +increase the release of dopamine which + + align:start position:0% +increase the release of dopamine which + + + align:start position:0% +increase the release of dopamine which +is a + + align:start position:0% +is a + + + align:start position:0% +is a +neurotransmitter um and they also seem + + align:start position:0% +neurotransmitter um and they also seem + + + align:start position:0% +neurotransmitter um and they also seem +to inhibit re-uptake of dopamine and + + align:start position:0% +to inhibit re-uptake of dopamine and + + + align:start position:0% +to inhibit re-uptake of dopamine and +serotonin as I'll I'll talk about + + align:start position:0% +serotonin as I'll I'll talk about + + + align:start position:0% +serotonin as I'll I'll talk about +reuptake very briefly in a + + align:start position:0% +reuptake very briefly in a + + + align:start position:0% +reuptake very briefly in a +moment for many medications both + + align:start position:0% +moment for many medications both + + + align:start position:0% +moment for many medications both +actually for many medications no matter + + align:start position:0% +actually for many medications no matter + + + align:start position:0% +actually for many medications no matter +whether or not they affect your brain or + + align:start position:0% +whether or not they affect your brain or + + + align:start position:0% +whether or not they affect your brain or +other parts of your body the precise + + align:start position:0% +other parts of your body the precise + + + align:start position:0% +other parts of your body the precise +mechanism of action is not is really not + + align:start position:0% +mechanism of action is not is really not + + + align:start position:0% +mechanism of action is not is really not +known there are guesses there's data but + + align:start position:0% +known there are guesses there's data but + + + align:start position:0% +known there are guesses there's data but +the precise mechanism is often not known + + align:start position:0% +the precise mechanism is often not known + + + align:start position:0% +the precise mechanism is often not known +so let's use that as a + + align:start position:0% +so let's use that as a + + + align:start position:0% +so let's use that as a +segue into our lecture I won't have + + align:start position:0% +segue into our lecture I won't have + + + align:start position:0% +segue into our lecture I won't have +office hours today due to my schedule I + + align:start position:0% +office hours today due to my schedule I + + + align:start position:0% +office hours today due to my schedule I +will have them next Wednesday due to the + + align:start position:0% +will have them next Wednesday due to the + + + align:start position:0% +will have them next Wednesday due to the +vacation schedule and you're welcome to + + align:start position:0% +vacation schedule and you're welcome to + + + align:start position:0% +vacation schedule and you're welcome to +email me in the meantime all right + + align:start position:0% + + + + align:start position:0% + +we've been walking through the cells + + align:start position:0% +we've been walking through the cells + + + align:start position:0% +we've been walking through the cells +involved in nervous system formation the + + align:start position:0% +involved in nervous system formation the + + + align:start position:0% +involved in nervous system formation the +connections between the cells and now + + align:start position:0% +connections between the cells and now + + + align:start position:0% +connections between the cells and now +today we're going to finish talking + + align:start position:0% +today we're going to finish talking + + + align:start position:0% +today we're going to finish talking +about the connections between the cells + + align:start position:0% +about the connections between the cells + + + align:start position:0% +about the connections between the cells +and segue into the incredibly complex + + align:start position:0% +and segue into the incredibly complex + + + align:start position:0% +and segue into the incredibly complex +topic of circuits in the nervous + + align:start position:0% +topic of circuits in the nervous + + + align:start position:0% +topic of circuits in the nervous +system so today the first thing I want + + align:start position:0% +system so today the first thing I want + + + align:start position:0% +system so today the first thing I want +to talk about is + + align:start position:0% +to talk about is + + + align:start position:0% +to talk about is +regulating + + align:start position:0% +regulating + + + align:start position:0% +regulating +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +synapses and you + + align:start position:0% +synapses and you + + + align:start position:0% +synapses and you +remember that we're talking about + + align:start position:0% +remember that we're talking about + + + align:start position:0% +remember that we're talking about +chemical + + align:start position:0% + + + + align:start position:0% + +synapses and the second thing I want to + + align:start position:0% +synapses and the second thing I want to + + + align:start position:0% +synapses and the second thing I want to +talk + + align:start position:0% +talk + + + align:start position:0% +talk +about are circuits is there a problem + + align:start position:0% +about are circuits is there a problem + + + align:start position:0% +about are circuits is there a problem +can you hear me okay at the back thumbs + + align:start position:0% +can you hear me okay at the back thumbs + + + align:start position:0% +can you hear me okay at the back thumbs +up great + + align:start position:0% + + + + align:start position:0% + +good when I introduced circuits when I + + align:start position:0% +good when I introduced circuits when I + + + align:start position:0% +good when I introduced circuits when I +introduced synapses to you + + align:start position:0% +introduced synapses to you + + + align:start position:0% +introduced synapses to you +I told you that one of the reasons that + + align:start position:0% +I told you that one of the reasons that + + + align:start position:0% +I told you that one of the reasons that +there was this chemical synapse in the + + align:start position:0% +there was this chemical synapse in the + + + align:start position:0% +there was this chemical synapse in the +midst with it slow chemical synapse in + + align:start position:0% +midst with it slow chemical synapse in + + + align:start position:0% +midst with it slow chemical synapse in +the midst of this rapid electrical + + align:start position:0% +the midst of this rapid electrical + + + align:start position:0% +the midst of this rapid electrical +transmission was because you could + + align:start position:0% +transmission was because you could + + + align:start position:0% +transmission was because you could +regulate synapses and that is really + + align:start position:0% +regulate synapses and that is really + + + align:start position:0% +regulate synapses and that is really +what fine-tunes US it allows us to + + align:start position:0% +what fine-tunes US it allows us to + + + align:start position:0% +what fine-tunes US it allows us to +respond in a graded way to stimuli both + + align:start position:0% +respond in a graded way to stimuli both + + + align:start position:0% +respond in a graded way to stimuli both +from within the body and outside it + + align:start position:0% +from within the body and outside it + + + align:start position:0% +from within the body and outside it +allows the body to adapt in ways that + + align:start position:0% +allows the body to adapt in ways that + + + align:start position:0% +allows the body to adapt in ways that +are not all or none where action + + align:start position:0% +are not all or none where action + + + align:start position:0% +are not all or none where action +potentials are all or none the overall + + align:start position:0% +potentials are all or none the overall + + + align:start position:0% +potentials are all or none the overall +response of the body clearly isn't it's + + align:start position:0% +response of the body clearly isn't it's + + + align:start position:0% +response of the body clearly isn't it's +very nuanced and all of this has to do + + align:start position:0% +very nuanced and all of this has to do + + + align:start position:0% +very nuanced and all of this has to do +with regulating chemical synapses and + + align:start position:0% +with regulating chemical synapses and + + + align:start position:0% +with regulating chemical synapses and +that's what we'll talk about for a few + + align:start position:0% +that's what we'll talk about for a few + + + align:start position:0% +that's what we'll talk about for a few +moments you can regulate chemical + + align:start position:0% +moments you can regulate chemical + + + align:start position:0% +moments you can regulate chemical +synapses by changing the amount of + + align:start position:0% +synapses by changing the amount of + + + align:start position:0% +synapses by changing the amount of +neurotransmitter + + align:start position:0% + + + + align:start position:0% + +and if you think about this for a moment + + align:start position:0% +and if you think about this for a moment + + + align:start position:0% +and if you think about this for a moment +if you think about the synapse there's + + align:start position:0% +if you think about the synapse there's + + + align:start position:0% +if you think about the synapse there's +the neurotransmitter released into the + + align:start position:0% +the neurotransmitter released into the + + + align:start position:0% +the neurotransmitter released into the +space between the two cells diffuses + + align:start position:0% +space between the two cells diffuses + + + align:start position:0% +space between the two cells diffuses +across the synaptic Clift and then does + + align:start position:0% +across the synaptic Clift and then does + + + align:start position:0% +across the synaptic Clift and then does +something to the post synaptic cell + + align:start position:0% +something to the post synaptic cell + + + align:start position:0% +something to the post synaptic cell +potentially to lead to an action + + align:start position:0% +potentially to lead to an action + + + align:start position:0% +potentially to lead to an action +potential now if that neurotransmitter + + align:start position:0% +potential now if that neurotransmitter + + + align:start position:0% +potential now if that neurotransmitter +stuck around in the space between the + + align:start position:0% +stuck around in the space between the + + + align:start position:0% +stuck around in the space between the +cells it would keep stimulating the post + + align:start position:0% +cells it would keep stimulating the post + + + align:start position:0% +cells it would keep stimulating the post +synaptic cell over and over and as more + + align:start position:0% +synaptic cell over and over and as more + + + align:start position:0% +synaptic cell over and over and as more +neurotransmitter was released so the + + align:start position:0% +neurotransmitter was released so the + + + align:start position:0% +neurotransmitter was released so the +post synaptic cell would be further + + align:start position:0% +post synaptic cell would be further + + + align:start position:0% +post synaptic cell would be further +stimulated and you'd get to a point + + align:start position:0% +stimulated and you'd get to a point + + + align:start position:0% +stimulated and you'd get to a point +where the post synaptic neuron was + + align:start position:0% +where the post synaptic neuron was + + + align:start position:0% +where the post synaptic neuron was +completely + + align:start position:0% +completely + + + align:start position:0% +completely +overstimulated and that's clearly not a + + align:start position:0% +overstimulated and that's clearly not a + + + align:start position:0% +overstimulated and that's clearly not a +way to regulate responsiveness to any + + align:start position:0% +way to regulate responsiveness to any + + + align:start position:0% +way to regulate responsiveness to any +stimuli so + + align:start position:0% +stimuli so + + + align:start position:0% +stimuli so +neurotransmitter does not stay in the + + align:start position:0% +neurotransmitter does not stay in the + + + align:start position:0% +neurotransmitter does not stay in the +synaptic Clift for very + + align:start position:0% + + + + align:start position:0% + +long so it's changing the amount of + + align:start position:0% +long so it's changing the amount of + + + align:start position:0% +long so it's changing the amount of +neurot + + align:start position:0% +neurot + + + align:start position:0% +neurot +transmitter + + align:start position:0% +transmitter + + + align:start position:0% +transmitter +via + + align:start position:0% + + + + align:start position:0% + +degradation once neurotransmitter is + + align:start position:0% +degradation once neurotransmitter is + + + align:start position:0% +degradation once neurotransmitter is +released in some cases it's degraded by + + align:start position:0% +released in some cases it's degraded by + + + align:start position:0% +released in some cases it's degraded by +specific enzymes for example in the case + + align:start position:0% +specific enzymes for example in the case + + + align:start position:0% +specific enzymes for example in the case +of acetyl + + align:start position:0% + + + + align:start position:0% + +choline there's a particular enzyme that + + align:start position:0% +choline there's a particular enzyme that + + + align:start position:0% +choline there's a particular enzyme that +breaks down acetyl choline and if that + + align:start position:0% +breaks down acetyl choline and if that + + + align:start position:0% +breaks down acetyl choline and if that +enzyme is inhibited you go into + + align:start position:0% +enzyme is inhibited you go into + + + align:start position:0% +enzyme is inhibited you go into +respiratory shock you cannot breathe + + align:start position:0% +respiratory shock you cannot breathe + + + align:start position:0% +respiratory shock you cannot breathe +anymore because you you have to activate + + align:start position:0% +anymore because you you have to activate + + + align:start position:0% +anymore because you you have to activate +and inactivate the muscles via the + + align:start position:0% +and inactivate the muscles via the + + + align:start position:0% +and inactivate the muscles via the +nerves as you + + align:start position:0% +nerves as you + + + align:start position:0% +nerves as you +breathe you can also regulate the amount + + align:start position:0% +breathe you can also regulate the amount + + + align:start position:0% +breathe you can also regulate the amount +of neurotransmitter by something called + + align:start position:0% +of neurotransmitter by something called + + + align:start position:0% +of neurotransmitter by something called +reuptake sometimes called + + align:start position:0% + + + + align:start position:0% + +reabsorption where the + + align:start position:0% +reabsorption where the + + + align:start position:0% +reabsorption where the +neurotransmitter + + align:start position:0% +neurotransmitter + + + align:start position:0% +neurotransmitter +so where the neurotransmitter is + + align:start position:0% +so where the neurotransmitter is + + + align:start position:0% +so where the neurotransmitter is +released and then it's taken up by the + + align:start position:0% +released and then it's taken up by the + + + align:start position:0% +released and then it's taken up by the +pratic cell which is kind of a a Frugal + + align:start position:0% +pratic cell which is kind of a a Frugal + + + align:start position:0% +pratic cell which is kind of a a Frugal +way of doing things it doesn't have to + + align:start position:0% +way of doing things it doesn't have to + + + align:start position:0% +way of doing things it doesn't have to +keep synthesizing the neurotransmitter + + align:start position:0% +keep synthesizing the neurotransmitter + + + align:start position:0% +keep synthesizing the neurotransmitter +and that so reabsorb reuptake by the + + align:start position:0% +and that so reabsorb reuptake by the + + + align:start position:0% +and that so reabsorb reuptake by the +pratic + + align:start position:0% + + + + align:start position:0% + +cell and that is the case for + + align:start position:0% +cell and that is the case for + + + align:start position:0% +cell and that is the case for +serotonin and + + align:start position:0% + + + + align:start position:0% + +dopamine and then in some cases you can + + align:start position:0% +dopamine and then in some cases you can + + + align:start position:0% +dopamine and then in some cases you can +regulate the in synth is the amount of + + align:start position:0% +regulate the in synth is the amount of + + + align:start position:0% +regulate the in synth is the amount of +neurotransmitter that's being made and + + align:start position:0% +neurotransmitter that's being made and + + + align:start position:0% +neurotransmitter that's being made and +the big class of neurotransmitters + + align:start position:0% +the big class of neurotransmitters + + + align:start position:0% +the big class of neurotransmitters +regulated in this way are the + + align:start position:0% +regulated in this way are the + + + align:start position:0% +regulated in this way are the +endorphins which are a group of peptide + + align:start position:0% +endorphins which are a group of peptide + + + align:start position:0% +endorphins which are a group of peptide +neurotransmitters that are the natural + + align:start position:0% +neurotransmitters that are the natural + + + align:start position:0% +neurotransmitters that are the natural +opiates of the body the natural pain um + + align:start position:0% +opiates of the body the natural pain um + + + align:start position:0% +opiates of the body the natural pain um +Regulators of the body and all of these + + align:start position:0% +Regulators of the body and all of these + + + align:start position:0% +Regulators of the body and all of these +processes are regulatable both for + + align:start position:0% +processes are regulatable both for + + + align:start position:0% +processes are regulatable both for +modulating normal + + align:start position:0% +modulating normal + + + align:start position:0% +modulating normal +synapses and also in all cases for for + + align:start position:0% +synapses and also in all cases for for + + + align:start position:0% +synapses and also in all cases for for +medication um for medication targets for + + align:start position:0% +medication um for medication targets for + + + align:start position:0% +medication um for medication targets for +drug targets so normal + + align:start position:0% + + + + align:start position:0% + +modulation and Drug + + align:start position:0% + + + + align:start position:0% + +targets let's look at a couple of + + align:start position:0% + + + + align:start position:0% + +slides acety choline is is a + + align:start position:0% +slides acety choline is is a + + + align:start position:0% +slides acety choline is is a +neurotransmitter that binds its receptor + + align:start position:0% +neurotransmitter that binds its receptor + + + align:start position:0% +neurotransmitter that binds its receptor +on the post synaptic membrane and after + + align:start position:0% +on the post synaptic membrane and after + + + align:start position:0% +on the post synaptic membrane and after +it's done so actil colonas the E here + + align:start position:0% +it's done so actil colonas the E here + + + align:start position:0% +it's done so actil colonas the E here +comes and breaks it down and stops IT + + align:start position:0% +comes and breaks it down and stops IT + + + align:start position:0% +comes and breaks it down and stops IT +restimulating the post synaptic + + align:start position:0% +restimulating the post synaptic + + + align:start position:0% +restimulating the post synaptic +cell many nerve + + align:start position:0% +cell many nerve + + + align:start position:0% +cell many nerve +gases sarin was one of the famous ones + + align:start position:0% +gases sarin was one of the famous ones + + + align:start position:0% +gases sarin was one of the famous ones +that was used in the Japanese + + align:start position:0% +that was used in the Japanese + + + align:start position:0% +that was used in the Japanese +underground some years ago inhibit atil + + align:start position:0% +underground some years ago inhibit atil + + + align:start position:0% +underground some years ago inhibit atil +colonas and in that case you get a + + align:start position:0% +colonas and in that case you get a + + + align:start position:0% +colonas and in that case you get a +buildup of acetel choline in the post in + + align:start position:0% +buildup of acetel choline in the post in + + + align:start position:0% +buildup of acetel choline in the post in +the synaptic cleft you get repeated + + align:start position:0% +the synaptic cleft you get repeated + + + align:start position:0% +the synaptic cleft you get repeated +stimulation of the post synaptic cell + + align:start position:0% +stimulation of the post synaptic cell + + + align:start position:0% +stimulation of the post synaptic cell +and that leads to as I said respiratory + + align:start position:0% +and that leads to as I said respiratory + + + align:start position:0% +and that leads to as I said respiratory +um paralysis and + + align:start position:0% +um paralysis and + + + align:start position:0% +um paralysis and +death our troops overseas have with them + + align:start position:0% +death our troops overseas have with them + + + align:start position:0% +death our troops overseas have with them +vials of + + align:start position:0% +vials of + + + align:start position:0% +vials of +atropine atropine is a competitive + + align:start position:0% +atropine atropine is a competitive + + + align:start position:0% +atropine atropine is a competitive +inhibitor of acetyl choline binds to the + + align:start position:0% +inhibitor of acetyl choline binds to the + + + align:start position:0% +inhibitor of acetyl choline binds to the +receptor and prevents acety choline from + + align:start position:0% +receptor and prevents acety choline from + + + align:start position:0% +receptor and prevents acety choline from +binding and in the case of a nerve gas + + align:start position:0% +binding and in the case of a nerve gas + + + align:start position:0% +binding and in the case of a nerve gas +attack if you inject yourself with + + align:start position:0% +attack if you inject yourself with + + + align:start position:0% +attack if you inject yourself with +atropine you'll stop the acetyl choline + + align:start position:0% +atropine you'll stop the acetyl choline + + + align:start position:0% +atropine you'll stop the acetyl choline +from working and you'll be okay you get + + align:start position:0% +from working and you'll be okay you get + + + align:start position:0% +from working and you'll be okay you get +a little kind of floppy but you can + + align:start position:0% +a little kind of floppy but you can + + + align:start position:0% +a little kind of floppy but you can +survive because they're alternate + + align:start position:0% +survive because they're alternate + + + align:start position:0% +survive because they're alternate +mechanisms of um stimulating those + + align:start position:0% +mechanisms of um stimulating those + + + align:start position:0% +mechanisms of um stimulating those +nerves + + align:start position:0% +nerves + + + align:start position:0% +nerves +okay here's serotonin the reuptake + + align:start position:0% +okay here's serotonin the reuptake + + + align:start position:0% +okay here's serotonin the reuptake +pathway serotonin is released as all + + align:start position:0% +pathway serotonin is released as all + + + align:start position:0% +pathway serotonin is released as all +neurotransmitters and then it's + + align:start position:0% +neurotransmitters and then it's + + + align:start position:0% +neurotransmitters and then it's +reabsorbed by the pratic cell and ssris + + align:start position:0% +reabsorbed by the pratic cell and ssris + + + align:start position:0% +reabsorbed by the pratic cell and ssris +whose mechanism of action is really not + + align:start position:0% +whose mechanism of action is really not + + + align:start position:0% +whose mechanism of action is really not +understood do something to block the + + align:start position:0% +understood do something to block the + + + align:start position:0% +understood do something to block the +re-uptake of + + align:start position:0% +re-uptake of + + + align:start position:0% +re-uptake of +Serotonin all + + align:start position:0% + + + + align:start position:0% + +right the other way clearly that one + + align:start position:0% +right the other way clearly that one + + + align:start position:0% +right the other way clearly that one +could modulate how often synapses are + + align:start position:0% +could modulate how often synapses are + + + align:start position:0% +could modulate how often synapses are +active or how often the post synaptic + + align:start position:0% +active or how often the post synaptic + + + align:start position:0% +active or how often the post synaptic +cell is stimulated is by modulating The + + align:start position:0% +cell is stimulated is by modulating The + + + align:start position:0% +cell is stimulated is by modulating The +receptors intuitively if you have more + + align:start position:0% +receptors intuitively if you have more + + + align:start position:0% +receptors intuitively if you have more +receptors the neurotransmitter has more + + align:start position:0% +receptors the neurotransmitter has more + + + align:start position:0% +receptors the neurotransmitter has more +place to bind it can send a greater + + align:start position:0% +place to bind it can send a greater + + + align:start position:0% +place to bind it can send a greater +signal by changing membrane potential if + + align:start position:0% +signal by changing membrane potential if + + + align:start position:0% +signal by changing membrane potential if +you decrease the number of receptors and + + align:start position:0% +you decrease the number of receptors and + + + align:start position:0% +you decrease the number of receptors and +so on and it turns out if you modify The + + align:start position:0% +so on and it turns out if you modify The + + + align:start position:0% +so on and it turns out if you modify The +receptors if you put phosphate groups on + + align:start position:0% +receptors if you put phosphate groups on + + + align:start position:0% +receptors if you put phosphate groups on +them sometimes you can also change how + + align:start position:0% +them sometimes you can also change how + + + align:start position:0% +them sometimes you can also change how +well they act so the other thing to + + align:start position:0% +well they act so the other thing to + + + align:start position:0% +well they act so the other thing to +do to modulate synaptic activity is by + + align:start position:0% +do to modulate synaptic activity is by + + + align:start position:0% +do to modulate synaptic activity is by +changing the + + align:start position:0% + + + + align:start position:0% + +receptors and there are really three + + align:start position:0% +receptors and there are really three + + + align:start position:0% +receptors and there are really three +ways to do + + align:start position:0% +ways to do + + + align:start position:0% +ways to do +this change in + + align:start position:0% + + + + align:start position:0% + +number or change in the type the + + align:start position:0% + + + + align:start position:0% + +subtype of a receptor where there might + + align:start position:0% +subtype of a receptor where there might + + + align:start position:0% +subtype of a receptor where there might +be a subtle change in amino acid because + + align:start position:0% +be a subtle change in amino acid because + + + align:start position:0% +be a subtle change in amino acid because +you're using now a different Gene to + + align:start position:0% +you're using now a different Gene to + + + align:start position:0% +you're using now a different Gene to +make the receptor you can increase or + + align:start position:0% +make the receptor you can increase or + + + align:start position:0% +make the receptor you can increase or +change the + + align:start position:0% + + + + align:start position:0% + +affinity for + + align:start position:0% +affinity for + + + align:start position:0% +affinity for +[Music] + + align:start position:0% + + + + align:start position:0% + +neurotransmitter and you can change + + align:start position:0% +neurotransmitter and you can change + + + align:start position:0% +neurotransmitter and you can change +receptor + + align:start position:0% + + + + align:start position:0% + +responsiveness all of these three things + + align:start position:0% +responsiveness all of these three things + + + align:start position:0% +responsiveness all of these three things +have got something to do + + align:start position:0% + + + + align:start position:0% + +with + + align:start position:0% +with + + + align:start position:0% +with +learning and + + align:start position:0% + + + + align:start position:0% + +memory they have to do with + + align:start position:0% + + + + align:start position:0% + +addiction and all of these changes are + + align:start position:0% +addiction and all of these changes are + + + align:start position:0% +addiction and all of these changes are +slow they occur over + + align:start position:0% +slow they occur over + + + align:start position:0% +slow they occur over +minutes + + align:start position:0% +minutes + + + align:start position:0% +minutes +days weeks + + align:start position:0% + + + + align:start position:0% + +even and for some we understand how + + align:start position:0% +even and for some we understand how + + + align:start position:0% +even and for some we understand how +these changes occur but for many we + + align:start position:0% +these changes occur but for many we + + + align:start position:0% +these changes occur but for many we +don't the outcome of changing the + + align:start position:0% +don't the outcome of changing the + + + align:start position:0% +don't the outcome of changing the +receptors and I see we have a board + + align:start position:0% +receptors and I see we have a board + + + align:start position:0% +receptors and I see we have a board +issue + + align:start position:0% +issue + + + align:start position:0% +issue +here um so I'm going to put this on + + align:start position:0% +here um so I'm going to put this on + + + align:start position:0% +here um so I'm going to put this on +actually let me put this board + + align:start position:0% + + + + align:start position:0% + +down and this board + + align:start position:0% +down and this board + + + align:start position:0% +down and this board +up one of the outcomes of changing all + + align:start position:0% +up one of the outcomes of changing all + + + align:start position:0% +up one of the outcomes of changing all +of these parameters about The receptors + + align:start position:0% +of these parameters about The receptors + + + align:start position:0% +of these parameters about The receptors +is that over a long period of time you + + align:start position:0% +is that over a long period of time you + + + align:start position:0% +is that over a long period of time you +really change how a synapse works and + + align:start position:0% +really change how a synapse works and + + + align:start position:0% +really change how a synapse works and +you can change how a synapse Works + + align:start position:0% +you can change how a synapse Works + + + align:start position:0% +you can change how a synapse Works +through these parameters by repeatedly + + align:start position:0% +through these parameters by repeatedly + + + align:start position:0% +through these parameters by repeatedly +stimulating that synapse okay this is + + align:start position:0% +stimulating that synapse okay this is + + + align:start position:0% +stimulating that synapse okay this is +what practice does when you practice + + align:start position:0% +what practice does when you practice + + + align:start position:0% +what practice does when you practice +your musical instrument or you practice + + align:start position:0% +your musical instrument or you practice + + + align:start position:0% +your musical instrument or you practice +your biochemistry problems and you do it + + align:start position:0% +your biochemistry problems and you do it + + + align:start position:0% +your biochemistry problems and you do it +over and over you're changing the + + align:start position:0% +over and over you're changing the + + + align:start position:0% +over and over you're changing the +synapses that allow you to engage these + + align:start position:0% +synapses that allow you to engage these + + + align:start position:0% +synapses that allow you to engage these +problems and these + + align:start position:0% +problems and these + + + align:start position:0% +problems and these +processes have got names so let me just + + align:start position:0% +processes have got names so let me just + + + align:start position:0% +processes have got names so let me just +complete this so by changing receptors + + align:start position:0% +complete this so by changing receptors + + + align:start position:0% +complete this so by changing receptors +so that repeated synaptic + + align:start position:0% + + + + align:start position:0% + +stimulation changes the responsiveness + + align:start position:0% +stimulation changes the responsiveness + + + align:start position:0% +stimulation changes the responsiveness +of the + + align:start position:0% + + + + align:start position:0% + +synapse generally + + align:start position:0% +synapse generally + + + align:start position:0% +synapse generally +as I say Through The receptors in this + + align:start position:0% +as I say Through The receptors in this + + + align:start position:0% +as I say Through The receptors in this +case okay and they there there two + + align:start position:0% +case okay and they there there two + + + align:start position:0% +case okay and they there there two +outputs one you can + + align:start position:0% +outputs one you can + + + align:start position:0% +outputs one you can +increase the synaptic response you can + + align:start position:0% +increase the synaptic response you can + + + align:start position:0% +increase the synaptic response you can +make it more likely that there'll be an + + align:start position:0% +make it more likely that there'll be an + + + align:start position:0% +make it more likely that there'll be an +action + + align:start position:0% +action + + + align:start position:0% +action +potential and that would take place at + + align:start position:0% +potential and that would take place at + + + align:start position:0% +potential and that would take place at +excitatory + + align:start position:0% + + + + align:start position:0% + +synapsis and this process is known as + + align:start position:0% +synapsis and this process is known as + + + align:start position:0% +synapsis and this process is known as +long long term + + align:start position:0% + + + + align:start position:0% + +potentiation it's the stuff you want + + align:start position:0% +potentiation it's the stuff you want + + + align:start position:0% +potentiation it's the stuff you want +when you're trying to learn something + + align:start position:0% +when you're trying to learn something + + + align:start position:0% +when you're trying to learn something +it's believed to be the way memory works + + align:start position:0% +it's believed to be the way memory works + + + align:start position:0% +it's believed to be the way memory works +you can also decrease the response of a + + align:start position:0% +you can also decrease the response of a + + + align:start position:0% +you can also decrease the response of a +particular synapse and that would work + + align:start position:0% +particular synapse and that would work + + + align:start position:0% +particular synapse and that would work +if it was an inhibitory + + align:start position:0% + + + + align:start position:0% + +synapse and in that case the process is + + align:start position:0% +synapse and in that case the process is + + + align:start position:0% +synapse and in that case the process is +called long-term + + align:start position:0% + + + + align:start position:0% + +let's just write it out + + align:start position:0% +let's just write it out + + + align:start position:0% +let's just write it out +long-term + + align:start position:0% + + + + align:start position:0% + +depression both of these processes have + + align:start position:0% +depression both of these processes have + + + align:start position:0% +depression both of these processes have +been shown to work in the lab in culture + + align:start position:0% +been shown to work in the lab in culture + + + align:start position:0% +been shown to work in the lab in culture +hard to do those experiments in real + + align:start position:0% +hard to do those experiments in real + + + align:start position:0% +hard to do those experiments in real +animals but it's believed that that's + + align:start position:0% +animals but it's believed that that's + + + align:start position:0% +animals but it's believed that that's +how memory works so on your first + + align:start position:0% +how memory works so on your first + + + align:start position:0% +how memory works so on your first +handout I've drawn out for you the idea + + align:start position:0% +handout I've drawn out for you the idea + + + align:start position:0% +handout I've drawn out for you the idea +here's a normal axon the pr synaptic and + + align:start position:0% +here's a normal axon the pr synaptic and + + + align:start position:0% +here's a normal axon the pr synaptic and +the post synaptic cell neurotrans + + align:start position:0% +the post synaptic cell neurotrans + + + align:start position:0% +the post synaptic cell neurotrans +Transit is released it engages receptors + + align:start position:0% +Transit is released it engages receptors + + + align:start position:0% +Transit is released it engages receptors +and at some frequency there's an action + + align:start position:0% +and at some frequency there's an action + + + align:start position:0% +and at some frequency there's an action +potential + + align:start position:0% +potential + + + align:start position:0% +potential +elicited if you change if you repeatedly + + align:start position:0% +elicited if you change if you repeatedly + + + align:start position:0% +elicited if you change if you repeatedly +stimulate that axon over time days + + align:start position:0% +stimulate that axon over time days + + + align:start position:0% +stimulate that axon over time days +minutes you change the receptor Spectrum + + align:start position:0% +minutes you change the receptor Spectrum + + + align:start position:0% +minutes you change the receptor Spectrum +on the post synaptic cell and in + + align:start position:0% +on the post synaptic cell and in + + + align:start position:0% +on the post synaptic cell and in +long-term potentiation responsiveness + + align:start position:0% +long-term potentiation responsiveness + + + align:start position:0% +long-term potentiation responsiveness +increases whereas in long-term + + align:start position:0% +increases whereas in long-term + + + align:start position:0% +increases whereas in long-term +depression you decrease receptor number + + align:start position:0% +depression you decrease receptor number + + + align:start position:0% +depression you decrease receptor number +or some other parameter and you lead to + + align:start position:0% +or some other parameter and you lead to + + + align:start position:0% +or some other parameter and you lead to +decreased responsiveness + + align:start position:0% + + + + align:start position:0% + +okay let us move on + + align:start position:0% + + + + align:start position:0% + +to our second topic which is that of + + align:start position:0% + + + + align:start position:0% + +circuits which refers to multiple + + align:start position:0% +circuits which refers to multiple + + + align:start position:0% +circuits which refers to multiple +connectivities multiple synapses forming + + align:start position:0% +connectivities multiple synapses forming + + + align:start position:0% +connectivities multiple synapses forming +in a way that is stable and that can + + align:start position:0% +in a way that is stable and that can + + + align:start position:0% +in a way that is stable and that can +lead to particular outcomes of + + align:start position:0% +lead to particular outcomes of + + + align:start position:0% +lead to particular outcomes of +particular + + align:start position:0% + + + + align:start position:0% + +stimuli let's look at your next handout + + align:start position:0% +stimuli let's look at your next handout + + + align:start position:0% +stimuli let's look at your next handout +to try to get a sense of where we + + align:start position:0% +to try to get a sense of where we + + + align:start position:0% +to try to get a sense of where we +are so I've diagrammed this out for you + + align:start position:0% +are so I've diagrammed this out for you + + + align:start position:0% +are so I've diagrammed this out for you +and I've started here with some kind of + + align:start position:0% +and I've started here with some kind of + + + align:start position:0% +and I've started here with some kind of +sensory neuron an interneuron and a + + align:start position:0% +sensory neuron an interneuron and a + + + align:start position:0% +sensory neuron an interneuron and a +motor neuron three connected + + align:start position:0% +motor neuron three connected + + + align:start position:0% +motor neuron three connected +neurons you could put a lot of these + + align:start position:0% +neurons you could put a lot of these + + + align:start position:0% +neurons you could put a lot of these +other things called called interneurons + + align:start position:0% +other things called called interneurons + + + align:start position:0% +other things called called interneurons +in the way Sensory neurons receive + + align:start position:0% +in the way Sensory neurons receive + + + align:start position:0% +in the way Sensory neurons receive +signals motor neurons tell things to + + align:start position:0% +signals motor neurons tell things to + + + align:start position:0% +signals motor neurons tell things to +happen like muscles to work and Inter + + align:start position:0% +happen like muscles to work and Inter + + + align:start position:0% +happen like muscles to work and Inter +neurons of which there can be many are + + align:start position:0% +neurons of which there can be many are + + + align:start position:0% +neurons of which there can be many are +the connectors between sensory and motor + + align:start position:0% +the connectors between sensory and motor + + + align:start position:0% +the connectors between sensory and motor +neurons there's an input and there's an + + align:start position:0% +neurons there's an input and there's an + + + align:start position:0% +neurons there's an input and there's an +output and what happens in + + align:start position:0% +output and what happens in + + + align:start position:0% +output and what happens in +between this is a synthesis of what + + align:start position:0% +between this is a synthesis of what + + + align:start position:0% +between this is a synthesis of what +we've talked about over the last couple + + align:start position:0% +we've talked about over the last couple + + + align:start position:0% +we've talked about over the last couple +of + + align:start position:0% +of + + + align:start position:0% +of +lectures the sensory neuron makes + + align:start position:0% +lectures the sensory neuron makes + + + align:start position:0% +lectures the sensory neuron makes +multiple synapses onto the interneuron + + align:start position:0% +multiple synapses onto the interneuron + + + align:start position:0% +multiple synapses onto the interneuron +they can be excitatory or inhibitory + + align:start position:0% +they can be excitatory or inhibitory + + + align:start position:0% +they can be excitatory or inhibitory +they're summated the interneuron then + + align:start position:0% +they're summated the interneuron then + + + align:start position:0% +they're summated the interneuron then +decides whether to make an action + + align:start position:0% +decides whether to make an action + + + align:start position:0% +decides whether to make an action +potential or not action potential yes or + + align:start position:0% +potential or not action potential yes or + + + align:start position:0% +potential or not action potential yes or +no in each case if it makes an action + + align:start position:0% +no in each case if it makes an action + + + align:start position:0% +no in each case if it makes an action +potential it sends its signal to the + + align:start position:0% +potential it sends its signal to the + + + align:start position:0% +potential it sends its signal to the +next neuron the motor neuron that motor + + align:start position:0% +next neuron the motor neuron that motor + + + align:start position:0% +next neuron the motor neuron that motor +neuron is getting a bunch of inputs + + align:start position:0% +neuron is getting a bunch of inputs + + + align:start position:0% +neuron is getting a bunch of inputs +excitatory or inhibitory and it again + + align:start position:0% +excitatory or inhibitory and it again + + + align:start position:0% +excitatory or inhibitory and it again +has to decide whether or not there's an + + align:start position:0% +has to decide whether or not there's an + + + align:start position:0% +has to decide whether or not there's an +action potential okay so that's the + + align:start position:0% +action potential okay so that's the + + + align:start position:0% +action potential okay so that's the +context that puts circuits where we have + + align:start position:0% +context that puts circuits where we have + + + align:start position:0% +context that puts circuits where we have +been discussing the process of setting + + align:start position:0% +been discussing the process of setting + + + align:start position:0% +been discussing the process of setting +up the connections in the nervous + + align:start position:0% + + + + align:start position:0% + +system the thing about circuits and + + align:start position:0% +system the thing about circuits and + + + align:start position:0% +system the thing about circuits and +here's a term you should know is that + + align:start position:0% +here's a term you should know is that + + + align:start position:0% +here's a term you should know is that +they have to do with + + align:start position:0% +they have to do with + + + align:start position:0% +they have to do with +axon path + + align:start position:0% + + + + align:start position:0% + +finding and so let's for a moment forget + + align:start position:0% +finding and so let's for a moment forget + + + align:start position:0% +finding and so let's for a moment forget +this diag + + align:start position:0% +this diag + + + align:start position:0% +this diag +which is a diagram of what there is in + + align:start position:0% +which is a diagram of what there is in + + + align:start position:0% +which is a diagram of what there is in +the adult and let's think about how + + align:start position:0% +the adult and let's think about how + + + align:start position:0% +the adult and let's think about how +these circuits are set up the circuits + + align:start position:0% +these circuits are set up the circuits + + + align:start position:0% +these circuits are set up the circuits +that we have in our brains and in our + + align:start position:0% +that we have in our brains and in our + + + align:start position:0% +that we have in our brains and in our +bodies are of the close to uncountable + + align:start position:0% +bodies are of the close to uncountable + + + align:start position:0% +bodies are of the close to uncountable +I'm not sure we ever will count them in + + align:start position:0% +I'm not sure we ever will count them in + + + align:start position:0% +I'm not sure we ever will count them in +an animal as complex as ourselves it's + + align:start position:0% +an animal as complex as ourselves it's + + + align:start position:0% +an animal as complex as ourselves it's +been done in + + align:start position:0% +been done in + + + align:start position:0% +been done in +cbtis which has got a thousand cells the + + align:start position:0% +cbtis which has got a thousand cells the + + + align:start position:0% +cbtis which has got a thousand cells the +little worm we talked about it's got a + + align:start position:0% +little worm we talked about it's got a + + + align:start position:0% +little worm we talked about it's got a +thousand cells and all of the connect + + align:start position:0% +thousand cells and all of the connect + + + align:start position:0% +thousand cells and all of the connect +in cbdas have been mapped and they are + + align:start position:0% +in cbdas have been mapped and they are + + + align:start position:0% +in cbdas have been mapped and they are +extremely complex but that's just a + + align:start position:0% +extremely complex but that's just a + + + align:start position:0% +extremely complex but that's just a +handful of neurons when you're talking + + align:start position:0% +handful of neurons when you're talking + + + align:start position:0% +handful of neurons when you're talking +about 10 to the 10th 10 to the 11th + + align:start position:0% +about 10 to the 10th 10 to the 11th + + + align:start position:0% +about 10 to the 10th 10 to the 11th +neurons those connections are + + align:start position:0% +neurons those connections are + + + align:start position:0% +neurons those connections are +enormous but we can ask some basic + + align:start position:0% +enormous but we can ask some basic + + + align:start position:0% +enormous but we can ask some basic +questions okay and let's just state it + + align:start position:0% +questions okay and let's just state it + + + align:start position:0% +questions okay and let's just state it +neurons are + + align:start position:0% +neurons are + + + align:start position:0% +neurons are +connected to form circuits + + align:start position:0% + + + + align:start position:0% + +we can say that they're functional + + align:start position:0% +we can say that they're functional + + + align:start position:0% +we can say that they're functional +circuits if you + + align:start position:0% +circuits if you + + + align:start position:0% +circuits if you +like that is implicit and the big + + align:start position:0% +like that is implicit and the big + + + align:start position:0% +like that is implicit and the big +question is how do these circuits know + + align:start position:0% +question is how do these circuits know + + + align:start position:0% +question is how do these circuits know +where to + + align:start position:0% + + + + align:start position:0% + +form or if you like the + + align:start position:0% +form or if you like the + + + align:start position:0% +form or if you like the +restatement how do the neurons know + + align:start position:0% +restatement how do the neurons know + + + align:start position:0% +restatement how do the neurons know +where to go + + align:start position:0% + + + + align:start position:0% + +know where to go and where to + + align:start position:0% + + + + align:start position:0% + +connect and there are two kind of + + align:start position:0% +connect and there are two kind of + + + align:start position:0% +connect and there are two kind of +intuitive answers both of which turn out + + align:start position:0% +intuitive answers both of which turn out + + + align:start position:0% +intuitive answers both of which turn out +to be correct either the neurons just go + + align:start position:0% +to be correct either the neurons just go + + + align:start position:0% +to be correct either the neurons just go +every which way and if it works that's + + align:start position:0% +every which way and if it works that's + + + align:start position:0% +every which way and if it works that's +retained and the rest of the connections + + align:start position:0% +retained and the rest of the connections + + + align:start position:0% +retained and the rest of the connections +just are dissolved and go way and that's + + align:start position:0% +just are dissolved and go way and that's + + + align:start position:0% +just are dissolved and go way and that's +true but the bigger truth is that the + + align:start position:0% +true but the bigger truth is that the + + + align:start position:0% +true but the bigger truth is that the +neurons are told where to + + align:start position:0% +neurons are told where to + + + align:start position:0% +neurons are told where to +go so you can phrase these that the + + align:start position:0% +go so you can phrase these that the + + + align:start position:0% +go so you can phrase these that the +neurons undergo some kind of random + + align:start position:0% +neurons undergo some kind of random + + + align:start position:0% +neurons undergo some kind of random +process where neurons + + align:start position:0% +process where neurons + + + align:start position:0% +process where neurons +survive if connections M are + + align:start position:0% + + + + align:start position:0% + +made or there's some kind of guided + + align:start position:0% +made or there's some kind of guided + + + align:start position:0% +made or there's some kind of guided +process where the neurons are told where + + align:start position:0% +process where the neurons are told where + + + align:start position:0% +process where the neurons are told where +to + + align:start position:0% + + + + align:start position:0% + +go and both of these turn out after many + + align:start position:0% +go and both of these turn out after many + + + align:start position:0% +go and both of these turn out after many +many years of work to be + + align:start position:0% + + + + align:start position:0% + +correct let's look at some slides here + + align:start position:0% +correct let's look at some slides here + + + align:start position:0% +correct let's look at some slides here +this is work from Professor fee over in + + align:start position:0% +this is work from Professor fee over in + + + align:start position:0% +this is work from Professor fee over in +brain and cognitive science he studies + + align:start position:0% +brain and cognitive science he studies + + + align:start position:0% +brain and cognitive science he studies +these little books birds and their s + + align:start position:0% +these little books birds and their s + + + align:start position:0% +these little books birds and their s +circuit which forms and reforms during + + align:start position:0% +circuit which forms and reforms during + + + align:start position:0% +circuit which forms and reforms during +the life of the bird the circuit is + + align:start position:0% +the life of the bird the circuit is + + + align:start position:0% +the life of the bird the circuit is +complicated these are not single neurons + + align:start position:0% +complicated these are not single neurons + + + align:start position:0% +complicated these are not single neurons +there are bundles of neurons but it's + + align:start position:0% +there are bundles of neurons but it's + + + align:start position:0% +there are bundles of neurons but it's +kind of mappable and this is one of the + + align:start position:0% +kind of mappable and this is one of the + + + align:start position:0% +kind of mappable and this is one of the +circuits it's got something to do with + + align:start position:0% +circuits it's got something to do with + + + align:start position:0% +circuits it's got something to do with +song within the bird brain it's not the + + align:start position:0% +song within the bird brain it's not the + + + align:start position:0% +song within the bird brain it's not the +entire circuit that's one of the things + + align:start position:0% +entire circuit that's one of the things + + + align:start position:0% +entire circuit that's one of the things +that's going on here on + + align:start position:0% +that's going on here on + + + align:start position:0% +that's going on here on +campus but when you start thinking about + + align:start position:0% +campus but when you start thinking about + + + align:start position:0% +campus but when you start thinking about +things like language I really like the + + align:start position:0% +things like language I really like the + + + align:start position:0% +things like language I really like the +slide + + align:start position:0% +slide + + + align:start position:0% +slide +because these are activity plots of the + + align:start position:0% +because these are activity plots of the + + + align:start position:0% +because these are activity plots of the +brain that can be done in a number of + + align:start position:0% +brain that can be done in a number of + + + align:start position:0% +brain that can be done in a number of +ways by monitoring oxygen uptake or + + align:start position:0% +ways by monitoring oxygen uptake or + + + align:start position:0% +ways by monitoring oxygen uptake or +glucose use but you can look and see + + align:start position:0% +glucose use but you can look and see + + + align:start position:0% +glucose use but you can look and see +different parts of the brain active and + + align:start position:0% +different parts of the brain active and + + + align:start position:0% +different parts of the brain active and +when you think about language here are + + align:start position:0% +when you think about language here are + + + align:start position:0% +when you think about language here are +these four parts of the brain actually + + align:start position:0% +these four parts of the brain actually + + + align:start position:0% +these four parts of the brain actually +here's a huge part of the brain used to + + align:start position:0% +here's a huge part of the brain used to + + + align:start position:0% +here's a huge part of the brain used to +generate words each of these parts of + + align:start position:0% +generate words each of these parts of + + + align:start position:0% +generate words each of these parts of +the brain are millions and millions of + + align:start position:0% +the brain are millions and millions of + + + align:start position:0% +the brain are millions and millions of +neurons which are connected to one + + align:start position:0% +neurons which are connected to one + + + align:start position:0% +neurons which are connected to one +another within these regions + + align:start position:0% +another within these regions + + + align:start position:0% +another within these regions +and then each of these regions is + + align:start position:0% +and then each of these regions is + + + align:start position:0% +and then each of these regions is +connected to one another and each of + + align:start position:0% +connected to one another and each of + + + align:start position:0% +connected to one another and each of +those regions is connected to the output + + align:start position:0% +those regions is connected to the output + + + align:start position:0% +those regions is connected to the output +which would be all of your vocal + + align:start position:0% +which would be all of your vocal + + + align:start position:0% +which would be all of your vocal +apparatus and all of this is connected + + align:start position:0% +apparatus and all of this is connected + + + align:start position:0% +apparatus and all of this is connected +to your auditory apparatus to your + + align:start position:0% +to your auditory apparatus to your + + + align:start position:0% +to your auditory apparatus to your +visual system so that you can read words + + align:start position:0% +visual system so that you can read words + + + align:start position:0% +visual system so that you can read words +they can be processed and so on the + + align:start position:0% +they can be processed and so on the + + + align:start position:0% +they can be processed and so on the +connections that give language probably + + align:start position:0% +connections that give language probably + + + align:start position:0% +connections that give language probably +take a very large part of your brain I + + align:start position:0% +take a very large part of your brain I + + + align:start position:0% +take a very large part of your brain I +would throw out 15 to 20% of your brain + + align:start position:0% +would throw out 15 to 20% of your brain + + + align:start position:0% +would throw out 15 to 20% of your brain +is involved in some aspect of language + + align:start position:0% +is involved in some aspect of language + + + align:start position:0% +is involved in some aspect of language +receiving generating or output and the + + align:start position:0% +receiving generating or output and the + + + align:start position:0% +receiving generating or output and the +circuits there as I said are enormous + + align:start position:0% +circuits there as I said are enormous + + + align:start position:0% +circuits there as I said are enormous +okay so do neurons know where to go let + + align:start position:0% +okay so do neurons know where to go let + + + align:start position:0% +okay so do neurons know where to go let +me go with you this isn't on your + + align:start position:0% +me go with you this isn't on your + + + align:start position:0% +me go with you this isn't on your +handout this is to look on the screen do + + align:start position:0% +handout this is to look on the screen do + + + align:start position:0% +handout this is to look on the screen do +neurons know where to connect there was + + align:start position:0% +neurons know where to connect there was + + + align:start position:0% +neurons know where to connect there was +a very famous experiment done by sper + + align:start position:0% +a very famous experiment done by sper + + + align:start position:0% +a very famous experiment done by sper +some many years ago Roger Sperry who got + + align:start position:0% +some many years ago Roger Sperry who got + + + align:start position:0% +some many years ago Roger Sperry who got +a Nobel Prize for his work that involved + + align:start position:0% +a Nobel Prize for his work that involved + + + align:start position:0% +a Nobel Prize for his work that involved +a frog and it involved figuring out + + align:start position:0% +a frog and it involved figuring out + + + align:start position:0% +a frog and it involved figuring out +where the neurons in the retina went so + + align:start position:0% +where the neurons in the retina went so + + + align:start position:0% +where the neurons in the retina went so +it turns out if you look at your eyes + + align:start position:0% +it turns out if you look at your eyes + + + align:start position:0% +it turns out if you look at your eyes +okay there are neurons that go from your + + align:start position:0% +okay there are neurons that go from your + + + align:start position:0% +okay there are neurons that go from your +eye back into your + + align:start position:0% +eye back into your + + + align:start position:0% +eye back into your +brain the neurons on the side of your + + align:start position:0% +brain the neurons on the side of your + + + align:start position:0% +brain the neurons on the side of your +nose are called the nasal neurons and + + align:start position:0% +nose are called the nasal neurons and + + + align:start position:0% +nose are called the nasal neurons and +the neurons on the side of your the + + align:start position:0% +the neurons on the side of your the + + + align:start position:0% +the neurons on the side of your the +outside of your face are called temporal + + align:start position:0% +outside of your face are called temporal + + + align:start position:0% +outside of your face are called temporal +neurons and what sper did was to take an + + align:start position:0% +neurons and what sper did was to take an + + + align:start position:0% +neurons and what sper did was to take an +adult frog and rotate the eye + + align:start position:0% +adult frog and rotate the eye + + + align:start position:0% +adult frog and rotate the eye +180° so that the nasal neurons would now + + align:start position:0% +180° so that the nasal neurons would now + + + align:start position:0% +180° so that the nasal neurons would now +be on the outside of the head the + + align:start position:0% +be on the outside of the head the + + + align:start position:0% +be on the outside of the head the +temporal neurons would be on the inside + + align:start position:0% +temporal neurons would be on the inside + + + align:start position:0% +temporal neurons would be on the inside +of the head okay and you know for a + + align:start position:0% +of the head okay and you know for a + + + align:start position:0% +of the head okay and you know for a +while after the operation the Frog was + + align:start position:0% +while after the operation the Frog was + + + align:start position:0% +while after the operation the Frog was +really + + align:start position:0% +really + + + align:start position:0% +really +confused but after a while it actually + + align:start position:0% +confused but after a while it actually + + + align:start position:0% +confused but after a while it actually +recovered so let's lay out this and the + + align:start position:0% +recovered so let's lay out this and the + + + align:start position:0% +recovered so let's lay out this and the +recovery as I'm going to tell you told + + align:start position:0% +recovery as I'm going to tell you told + + + align:start position:0% +recovery as I'm going to tell you told +Sperry and the world that neurons were + + align:start position:0% +Sperry and the world that neurons were + + + align:start position:0% +Sperry and the world that neurons were +told where to go so here is the retina + + align:start position:0% +told where to go so here is the retina + + + align:start position:0% +told where to go so here is the retina +depicted as a circle and here's a part + + align:start position:0% +depicted as a circle and here's a part + + + align:start position:0% +depicted as a circle and here's a part +of the brain called the optic tectum + + align:start position:0% +of the brain called the optic tectum + + + align:start position:0% +of the brain called the optic tectum +that the neurons connect to it's the + + align:start position:0% +that the neurons connect to it's the + + + align:start position:0% +that the neurons connect to it's the +first part of their circuit here are the + + align:start position:0% +first part of their circuit here are the + + + align:start position:0% +first part of their circuit here are the +temporal neurons connecting to the C + + align:start position:0% +temporal neurons connecting to the C + + + align:start position:0% +temporal neurons connecting to the C +region of the brain and the nasal + + align:start position:0% +region of the brain and the nasal + + + align:start position:0% +region of the brain and the nasal +neurons connecting to the r + + align:start position:0% +neurons connecting to the r + + + align:start position:0% +neurons connecting to the r +region so after to this rotation there + + align:start position:0% +region so after to this rotation there + + + align:start position:0% +region so after to this rotation there +were two possibilities one was that the + + align:start position:0% +were two possibilities one was that the + + + align:start position:0% +were two possibilities one was that the +axons growing out so so let's let's just + + align:start position:0% +axons growing out so so let's let's just + + + align:start position:0% +axons growing out so so let's let's just +be clear in this rotation these axons + + align:start position:0% +be clear in this rotation these axons + + + align:start position:0% +be clear in this rotation these axons +were severed they were cut they had to + + align:start position:0% +were severed they were cut they had to + + + align:start position:0% +were severed they were cut they had to +regrow and find their targets if they + + align:start position:0% +regrow and find their targets if they + + + align:start position:0% +regrow and find their targets if they +could so one possibility would be that + + align:start position:0% +could so one possibility would be that + + + align:start position:0% +could so one possibility would be that +the axons would grow out of this retina + + align:start position:0% +the axons would grow out of this retina + + + align:start position:0% +the axons would grow out of this retina +and they'd grow everywhere and they + + align:start position:0% +and they'd grow everywhere and they + + + align:start position:0% +and they'd grow everywhere and they +would make really wrong connections and + + align:start position:0% +would make really wrong connections and + + + align:start position:0% +would make really wrong connections and +things would be a mess in actual fact + + align:start position:0% +things would be a mess in actual fact + + + align:start position:0% +things would be a mess in actual fact +what really happened was that the nasal + + align:start position:0% +what really happened was that the nasal + + + align:start position:0% +what really happened was that the nasal +neurons even though they were on the + + align:start position:0% +neurons even though they were on the + + + align:start position:0% +neurons even though they were on the +wrong side of the face found their way + + align:start position:0% +wrong side of the face found their way + + + align:start position:0% +wrong side of the face found their way +to the r region and the texal neurons + + align:start position:0% +to the r region and the texal neurons + + + align:start position:0% +to the r region and the texal neurons +found their way to the Sea region just + + align:start position:0% +found their way to the Sea region just + + + align:start position:0% +found their way to the Sea region just +like they had connected to before and + + align:start position:0% +like they had connected to before and + + + align:start position:0% +like they had connected to before and +this was a really profound experiment + + align:start position:0% +this was a really profound experiment + + + align:start position:0% +this was a really profound experiment +that told investigators that axons knew + + align:start position:0% +that told investigators that axons knew + + + align:start position:0% +that told investigators that axons knew +where to go and we know the molecular + + align:start position:0% +where to go and we know the molecular + + + align:start position:0% +where to go and we know the molecular +basis of this now but I'm not going to + + align:start position:0% +basis of this now but I'm not going to + + + align:start position:0% +basis of this now but I'm not going to +tell you about + + align:start position:0% + + + + align:start position:0% + +it in order to understand more about + + align:start position:0% +it in order to understand more about + + + align:start position:0% +it in order to understand more about +this guidance process you need to + + align:start position:0% +this guidance process you need to + + + align:start position:0% +this guidance process you need to +understand a part of the axon that we + + align:start position:0% +understand a part of the axon that we + + + align:start position:0% +understand a part of the axon that we +haven't discussed and a time in the + + align:start position:0% +haven't discussed and a time in the + + + align:start position:0% +haven't discussed and a time in the +neurons life that we haven't discussed + + align:start position:0% +neurons life that we haven't discussed + + + align:start position:0% +neurons life that we haven't discussed +either and that is a time when neurons + + align:start position:0% +either and that is a time when neurons + + + align:start position:0% +either and that is a time when neurons +are growing most neuronal growth takes + + align:start position:0% +are growing most neuronal growth takes + + + align:start position:0% +are growing most neuronal growth takes +place during embryonic development but + + align:start position:0% +place during embryonic development but + + + align:start position:0% +place during embryonic development but +it continues throughout life and so this + + align:start position:0% +it continues throughout life and so this + + + align:start position:0% +it continues throughout life and so this +is a developmental process but also in + + align:start position:0% +is a developmental process but also in + + + align:start position:0% +is a developmental process but also in +that experiment that was an adult frog + + align:start position:0% +that experiment that was an adult frog + + + align:start position:0% +that experiment that was an adult frog +okay so + + align:start position:0% + + + + align:start position:0% + +guidance of neurons and as we'll + + align:start position:0% +guidance of neurons and as we'll + + + align:start position:0% +guidance of neurons and as we'll +discuss particularly + + align:start position:0% +discuss particularly + + + align:start position:0% +discuss particularly +axons occurs + + align:start position:0% +axons occurs + + + align:start position:0% +axons occurs +during + + align:start position:0% +during + + + align:start position:0% +during +development and + + align:start position:0% +development and + + + align:start position:0% +development and +repair and learning as well we can put + + align:start position:0% +repair and learning as well we can put + + + align:start position:0% +repair and learning as well we can put +that up as well during development + + align:start position:0% + + + + align:start position:0% + +repair and + + align:start position:0% +repair and + + + align:start position:0% +repair and +learning although I'd say for learning + + align:start position:0% +learning although I'd say for learning + + + align:start position:0% +learning although I'd say for learning +there's a bit of a question mark whether + + align:start position:0% +there's a bit of a question mark whether + + + align:start position:0% +there's a bit of a question mark whether +that's true but I think it's probably + + align:start position:0% +that's true but I think it's probably + + + align:start position:0% +that's true but I think it's probably +true + + align:start position:0% +true + + + align:start position:0% +true +okay and the cell that we need to + + align:start position:0% +okay and the cell that we need to + + + align:start position:0% +okay and the cell that we need to +consider is a committed neuron which is + + align:start position:0% +consider is a committed neuron which is + + + align:start position:0% +consider is a committed neuron which is +called a neuroblast doesn't matter but + + align:start position:0% +called a neuroblast doesn't matter but + + + align:start position:0% +called a neuroblast doesn't matter but +here's your committed + + align:start position:0% +here's your committed + + + align:start position:0% +here's your committed +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +neuron have to think back to past + + align:start position:0% +neuron have to think back to past + + + align:start position:0% +neuron have to think back to past +lectures a neuron that knows that it's + + align:start position:0% +lectures a neuron that knows that it's + + + align:start position:0% +lectures a neuron that knows that it's +going to be a neuron but hasn't decided + + align:start position:0% +going to be a neuron but hasn't decided + + + align:start position:0% +going to be a neuron but hasn't decided +to hasn't become one yet hasn't + + align:start position:0% +to hasn't become one yet hasn't + + + align:start position:0% +to hasn't become one yet hasn't +differentiated it's called a + + align:start position:0% +differentiated it's called a + + + align:start position:0% +differentiated it's called a +neuroblast and here it is it's just a + + align:start position:0% +neuroblast and here it is it's just a + + + align:start position:0% +neuroblast and here it is it's just a +cell body with the + + align:start position:0% + + + + align:start position:0% + +nucleus and over time this neuroblast + + align:start position:0% +nucleus and over time this neuroblast + + + align:start position:0% +nucleus and over time this neuroblast +sends out processes that are called + + align:start position:0% +sends out processes that are called + + + align:start position:0% +sends out processes that are called +neurites they initially look the same + + align:start position:0% +neurites they initially look the same + + + align:start position:0% +neurites they initially look the same +soon some of them become dendrites and + + align:start position:0% +soon some of them become dendrites and + + + align:start position:0% +soon some of them become dendrites and +one of them becomes an + + align:start position:0% +one of them becomes an + + + align:start position:0% +one of them becomes an +axon so + + align:start position:0% + + + + align:start position:0% + +neurite axon plus + + align:start position:0% + + + + align:start position:0% + +dendrite + + align:start position:0% + + + + align:start position:0% + +outgrowth so you have a cell now + + align:start position:0% +outgrowth so you have a cell now + + + align:start position:0% +outgrowth so you have a cell now +with some + + align:start position:0% +with some + + + align:start position:0% +with some +processes and one of these is going to + + align:start position:0% +processes and one of these is going to + + + align:start position:0% +processes and one of these is going to +be the axon and that axon grows and it's + + align:start position:0% +be the axon and that axon grows and it's + + + align:start position:0% +be the axon and that axon grows and it's +during that growth process that it + + align:start position:0% +during that growth process that it + + + align:start position:0% +during that growth process that it +figures out where to go the cell body + + align:start position:0% +figures out where to go the cell body + + + align:start position:0% +figures out where to go the cell body +doesn't move the dendrites don't move + + align:start position:0% +doesn't move the dendrites don't move + + + align:start position:0% +doesn't move the dendrites don't move +it's the axon that is doing the path + + align:start position:0% +it's the axon that is doing the path + + + align:start position:0% +it's the axon that is doing the path +finding so the + + align:start position:0% + + + + align:start position:0% + +axon extends + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +eventually Finds Its + + align:start position:0% + + + + align:start position:0% + +Target and this + + align:start position:0% +Target and this + + + align:start position:0% +Target and this +extension is a growth process that we'll + + align:start position:0% +extension is a growth process that we'll + + + align:start position:0% +extension is a growth process that we'll +talk + + align:start position:0% +talk + + + align:start position:0% +talk +about okay for every a nerve when we + + align:start position:0% +about okay for every a nerve when we + + + align:start position:0% +about okay for every a nerve when we +talk about nerves there are actually + + align:start position:0% +talk about nerves there are actually + + + align:start position:0% +talk about nerves there are actually +many many ax many neurons many axons + + align:start position:0% +many many ax many neurons many axons + + + align:start position:0% +many many ax many neurons many axons +they're bundles of axons and there's + + align:start position:0% +they're bundles of axons and there's + + + align:start position:0% +they're bundles of axons and there's +something about the first axon to find a + + align:start position:0% +something about the first axon to find a + + + align:start position:0% +something about the first axon to find a +Target that's very important the Pioneer + + align:start position:0% +Target that's very important the Pioneer + + + align:start position:0% +Target that's very important the Pioneer +axon the first one finds the + + align:start position:0% + + + + align:start position:0% + +Target and then others + + align:start position:0% + + + + align:start position:0% + +follow the same path it kind of lays + + align:start position:0% +follow the same path it kind of lays + + + align:start position:0% +follow the same path it kind of lays +down a path + + align:start position:0% +down a path + + + align:start position:0% +down a path +and they form + + align:start position:0% + + + + align:start position:0% + +bundles also called + + align:start position:0% +bundles also called + + + align:start position:0% +bundles also called +facies and these + + align:start position:0% +facies and these + + + align:start position:0% +facies and these +fices + + align:start position:0% +fices + + + align:start position:0% +fices +together make the + + align:start position:0% + + + + align:start position:0% + +nerve the part of the axon that's really + + align:start position:0% +nerve the part of the axon that's really + + + align:start position:0% +nerve the part of the axon that's really +important for this process is the very + + align:start position:0% +important for this process is the very + + + align:start position:0% +important for this process is the very +tip of the axon and it has a special + + align:start position:0% +tip of the axon and it has a special + + + align:start position:0% +tip of the axon and it has a special +name called the growth cone + + align:start position:0% + + + + align:start position:0% + +so the ax on tip or the growth + + align:start position:0% +so the ax on tip or the growth + + + align:start position:0% +so the ax on tip or the growth +cone is + + align:start position:0% +cone is + + + align:start position:0% +cone is +crucial and we can draw it on the + + align:start position:0% +crucial and we can draw it on the + + + align:start position:0% +crucial and we can draw it on the +board if we now + + align:start position:0% +board if we now + + + align:start position:0% +board if we now +draw an + + align:start position:0% + + + + align:start position:0% + +axon and we've blown it up now so + + align:start position:0% +axon and we've blown it up now so + + + align:start position:0% +axon and we've blown it up now so +usually you know we blow up and we lose + + align:start position:0% +usually you know we blow up and we lose + + + align:start position:0% +usually you know we blow up and we lose +bits but now we're not going to lose any + + align:start position:0% +bits but now we're not going to lose any + + + align:start position:0% +bits but now we're not going to lose any +bit of it here's the axon and down the + + align:start position:0% +bit of it here's the axon and down the + + + align:start position:0% +bit of it here's the axon and down the +length + + align:start position:0% + + + + align:start position:0% + +of the axon are parallel + + align:start position:0% +of the axon are parallel + + + align:start position:0% +of the axon are parallel +microtubules many of them and these + + align:start position:0% +microtubules many of them and these + + + align:start position:0% +microtubules many of them and these +microtubules both stabilize the + + align:start position:0% +microtubules both stabilize the + + + align:start position:0% +microtubules both stabilize the +axon and also transport substances to + + align:start position:0% +axon and also transport substances to + + + align:start position:0% +axon and also transport substances to +and from the cell + + align:start position:0% + + + + align:start position:0% + +body so they + + align:start position:0% +body so they + + + align:start position:0% +body so they +stabilize the + + align:start position:0% +stabilize the + + + align:start position:0% +stabilize the +shape of very long axons and they also + + align:start position:0% +shape of very long axons and they also + + + align:start position:0% +shape of very long axons and they also +transport like little railway + + align:start position:0% + + + + align:start position:0% + +tracks substances to and from the cell + + align:start position:0% +tracks substances to and from the cell + + + align:start position:0% +tracks substances to and from the cell +body that's not the tip of the + + align:start position:0% +body that's not the tip of the + + + align:start position:0% +body that's not the tip of the +axon at the very tip the microtubules + + align:start position:0% +axon at the very tip the microtubules + + + align:start position:0% +axon at the very tip the microtubules +end and they + + align:start position:0% +end and they + + + align:start position:0% +end and they +interdigitate with these finger-like + + align:start position:0% +interdigitate with these finger-like + + + align:start position:0% +interdigitate with these finger-like +protrusions which are very Dynamic that + + align:start position:0% +protrusions which are very Dynamic that + + + align:start position:0% +protrusions which are very Dynamic that +means they change all the time and these + + align:start position:0% +means they change all the time and these + + + align:start position:0% +means they change all the time and these +protrusions + + align:start position:0% +protrusions + + + align:start position:0% +protrusions +protrude because of polymerized actin + + align:start position:0% +protrude because of polymerized actin + + + align:start position:0% +protrude because of polymerized actin +and you might be saying we heard about + + align:start position:0% +and you might be saying we heard about + + + align:start position:0% +and you might be saying we heard about +that already Yes you heard about that in + + align:start position:0% +that already Yes you heard about that in + + + align:start position:0% +that already Yes you heard about that in +morphogenesis we've talked about this + + align:start position:0% +morphogenesis we've talked about this + + + align:start position:0% +morphogenesis we've talked about this +cell biology is cell biology whether + + align:start position:0% +cell biology is cell biology whether + + + align:start position:0% +cell biology is cell biology whether +it's about neurons or cells in your + + align:start position:0% +it's about neurons or cells in your + + + align:start position:0% +it's about neurons or cells in your +stomach or cells in your that give rise + + align:start position:0% +stomach or cells in your that give rise + + + align:start position:0% +stomach or cells in your that give rise +to the hairs on your head all of these + + align:start position:0% +to the hairs on your head all of these + + + align:start position:0% +to the hairs on your head all of these +cells are just cells so there are these + + align:start position:0% +cells are just cells so there are these + + + align:start position:0% +cells are just cells so there are these +protrusions at the + + align:start position:0% +protrusions at the + + + align:start position:0% +protrusions at the +end so this whole thing is the axon but + + align:start position:0% +end so this whole thing is the axon but + + + align:start position:0% +end so this whole thing is the axon but +the very end is the growth + + align:start position:0% +the very end is the growth + + + align:start position:0% +the very end is the growth +cone this very end is the growth + + align:start position:0% + + + + align:start position:0% + +cone and these + + align:start position:0% + + + + align:start position:0% + +protrusions go by the name of + + align:start position:0% +protrusions go by the name of + + + align:start position:0% +protrusions go by the name of +filopodia + + align:start position:0% +filopodia + + + align:start position:0% +filopodia +fenus and lamellopodia more flattened + + align:start position:0% +fenus and lamellopodia more flattened + + + align:start position:0% +fenus and lamellopodia more flattened +feet + + align:start position:0% + + + + align:start position:0% + +and they protrude because of the + + align:start position:0% +and they protrude because of the + + + align:start position:0% +and they protrude because of the +polymerization of actin within them so + + align:start position:0% + + + + align:start position:0% + +there's F + + align:start position:0% +there's F + + + align:start position:0% +there's F +actin leads + + align:start position:0% + + + + align:start position:0% + +to + + align:start position:0% + + + + align:start position:0% + +protrusions well that's one important + + align:start position:0% +protrusions well that's one important + + + align:start position:0% +protrusions well that's one important +thing and I'll show you a movie in a + + align:start position:0% +thing and I'll show you a movie in a + + + align:start position:0% +thing and I'll show you a movie in a +moment to show you that as an axon grows + + align:start position:0% +moment to show you that as an axon grows + + + align:start position:0% +moment to show you that as an axon grows +it's sending out zillions of these + + align:start position:0% +it's sending out zillions of these + + + align:start position:0% +it's sending out zillions of these +things all the time that are kind of + + align:start position:0% +things all the time that are kind of + + + align:start position:0% +things all the time that are kind of +feeling their way around the place + + align:start position:0% +feeling their way around the place + + + align:start position:0% +feeling their way around the place +actually I'll no I won't show you now + + align:start position:0% +actually I'll no I won't show you now + + + align:start position:0% +actually I'll no I won't show you now +because there's an intervening slide but + + align:start position:0% +because there's an intervening slide but + + + align:start position:0% +because there's an intervening slide but +the other thing you should know is that + + align:start position:0% +the other thing you should know is that + + + align:start position:0% +the other thing you should know is that +like all cells there are receptors on + + align:start position:0% +like all cells there are receptors on + + + align:start position:0% +like all cells there are receptors on +the surface of the growth cone that are + + align:start position:0% +the surface of the growth cone that are + + + align:start position:0% +the surface of the growth cone that are +also sampling what lians are in the + + align:start position:0% +also sampling what lians are in the + + + align:start position:0% +also sampling what lians are in the +environment and if the lians are + + align:start position:0% + + + + align:start position:0% + +favorable they will either stabilize + + align:start position:0% +favorable they will either stabilize + + + align:start position:0% +favorable they will either stabilize +these + + align:start position:0% +these + + + align:start position:0% +these +protrusions and make more of them take + + align:start position:0% +protrusions and make more of them take + + + align:start position:0% +protrusions and make more of them take +place so here are receptors all over the + + align:start position:0% + + + + align:start position:0% + +place this is a + + align:start position:0% + + + + align:start position:0% + +receptor and if + + align:start position:0% + + + + align:start position:0% + +receptors contact + + align:start position:0% + + + + align:start position:0% + +lians then again you will get fa actin + + align:start position:0% +lians then again you will get fa actin + + + align:start position:0% +lians then again you will get fa actin +formed and protrusions will be formed + + align:start position:0% +formed and protrusions will be formed + + + align:start position:0% +formed and protrusions will be formed +and they will be + + align:start position:0% +and they will be + + + align:start position:0% +and they will be +stabilized okay the growth cone is + + align:start position:0% +stabilized okay the growth cone is + + + align:start position:0% +stabilized okay the growth cone is +Paramount to axon outgrowth there are + + align:start position:0% +Paramount to axon outgrowth there are + + + align:start position:0% +Paramount to axon outgrowth there are +signals which both attract axons towards + + align:start position:0% +signals which both attract axons towards + + + align:start position:0% +signals which both attract axons towards +them and signals which repel + + align:start position:0% +them and signals which repel + + + align:start position:0% +them and signals which repel +axons we can call those not surprisingly + + align:start position:0% +axons we can call those not surprisingly + + + align:start position:0% +axons we can call those not surprisingly +attractive + + align:start position:0% +attractive + + + align:start position:0% +attractive +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +signals we'll talk about someon + + align:start position:0% +signals we'll talk about someon + + + align:start position:0% +signals we'll talk about someon +moment and in that case the growth cone + + align:start position:0% + + + + align:start position:0% + +extends and it + + align:start position:0% +extends and it + + + align:start position:0% +extends and it +extends not to be the dead horse here + + align:start position:0% +extends not to be the dead horse here + + + align:start position:0% +extends not to be the dead horse here +but because F actin increases or is + + align:start position:0% +but because F actin increases or is + + + align:start position:0% +but because F actin increases or is +stabilized and the flip is that the + + align:start position:0% +stabilized and the flip is that the + + + align:start position:0% +stabilized and the flip is that the +growth cone can be destabilized and + + align:start position:0% +growth cone can be destabilized and + + + align:start position:0% +growth cone can be destabilized and +literally + + align:start position:0% +literally + + + align:start position:0% +literally +collapse under repulsive signals + + align:start position:0% + + + + align:start position:0% + +the growth + + align:start position:0% + + + + align:start position:0% + +cone + + align:start position:0% +cone + + + align:start position:0% +cone +collapses and it collapses because fa + + align:start position:0% +collapses and it collapses because fa + + + align:start position:0% +collapses and it collapses because fa +actin now becomes G globular or + + align:start position:0% +actin now becomes G globular or + + + align:start position:0% +actin now becomes G globular or +unpolymerized Acton using exactly the + + align:start position:0% +unpolymerized Acton using exactly the + + + align:start position:0% +unpolymerized Acton using exactly the +same processes that we talked about + + align:start position:0% +same processes that we talked about + + + align:start position:0% +same processes that we talked about +during the morphogenesis lecture let's + + align:start position:0% +during the morphogenesis lecture let's + + + align:start position:0% +during the morphogenesis lecture let's +look at a couple of slides you don't + + align:start position:0% +look at a couple of slides you don't + + + align:start position:0% +look at a couple of slides you don't +have these so just look on the screen + + align:start position:0% +have these so just look on the screen + + + align:start position:0% +have these so just look on the screen +this is a cell drawn in professor + + align:start position:0% +this is a cell drawn in professor + + + align:start position:0% +this is a cell drawn in professor +loish's book here's the Leading Edge of + + align:start position:0% +loish's book here's the Leading Edge of + + + align:start position:0% +loish's book here's the Leading Edge of +the cell the direction of the cell is + + align:start position:0% +the cell the direction of the cell is + + + align:start position:0% +the cell the direction of the cell is +where there is lots of polymerized + + align:start position:0% +where there is lots of polymerized + + + align:start position:0% +where there is lots of polymerized +actin this I've just drawn on the board + + align:start position:0% +actin this I've just drawn on the board + + + align:start position:0% +actin this I've just drawn on the board +and here is an axonal growth cone and I + + align:start position:0% +and here is an axonal growth cone and I + + + align:start position:0% +and here is an axonal growth cone and I +really like this movie it's a timelaps + + align:start position:0% +really like this movie it's a timelaps + + + align:start position:0% +really like this movie it's a timelaps +taken over 10 minutes and you can see + + align:start position:0% +taken over 10 minutes and you can see + + + align:start position:0% +taken over 10 minutes and you can see +all these things at the end and on the + + align:start position:0% +all these things at the end and on the + + + align:start position:0% +all these things at the end and on the +sides + + align:start position:0% +sides + + + align:start position:0% +sides +these protrusions from the cell very + + align:start position:0% +these protrusions from the cell very + + + align:start position:0% +these protrusions from the cell very +active they're forming they're + + align:start position:0% +active they're forming they're + + + align:start position:0% +active they're forming they're +disaggregating forming again + + align:start position:0% +disaggregating forming again + + + align:start position:0% +disaggregating forming again +disaggregating as the cell those are the + + align:start position:0% +disaggregating as the cell those are the + + + align:start position:0% +disaggregating as the cell those are the +lamellopodia and the filopodia as the + + align:start position:0% +lamellopodia and the filopodia as the + + + align:start position:0% +lamellopodia and the filopodia as the +cell is kind of feeling its way through + + align:start position:0% +cell is kind of feeling its way through + + + align:start position:0% +cell is kind of feeling its way through +the environment trying to find somewhere + + align:start position:0% +the environment trying to find somewhere + + + align:start position:0% +the environment trying to find somewhere +to go okay so this is a real exploratory + + align:start position:0% +to go okay so this is a real exploratory + + + align:start position:0% +to go okay so this is a real exploratory +process by this + + align:start position:0% + + + + align:start position:0% + +cell + + align:start position:0% + + + + align:start position:0% + +good what are these guidance signals + + align:start position:0% +good what are these guidance signals + + + align:start position:0% +good what are these guidance signals +well this is not a mystery either lians + + align:start position:0% +well this is not a mystery either lians + + + align:start position:0% +well this is not a mystery either lians +we know about receptors you know about + + align:start position:0% +we know about receptors you know about + + + align:start position:0% +we know about receptors you know about +the guidance signals are + + align:start position:0% + + + + align:start position:0% + +lians and these + + align:start position:0% +lians and these + + + align:start position:0% +lians and these +lians when they're found to a + + align:start position:0% +lians when they're found to a + + + align:start position:0% +lians when they're found to a +receptor lead to signal transduction and + + align:start position:0% +receptor lead to signal transduction and + + + align:start position:0% +receptor lead to signal transduction and +acts on outgrowth so + + align:start position:0% +acts on outgrowth so + + + align:start position:0% +acts on outgrowth so +lians and we'll put in parentheses plus + + align:start position:0% + + + + align:start position:0% + +receptors to signal + + align:start position:0% + + + + align:start position:0% + +transduction and a change in the growth + + align:start position:0% +transduction and a change in the growth + + + align:start position:0% +transduction and a change in the growth +code + + align:start position:0% + + + + align:start position:0% + +there are two kinds of guidance signals + + align:start position:0% +there are two kinds of guidance signals + + + align:start position:0% +there are two kinds of guidance signals +that are reasonably separate from one + + align:start position:0% +that are reasonably separate from one + + + align:start position:0% +that are reasonably separate from one +another they're called short range and + + align:start position:0% +another they're called short range and + + + align:start position:0% +another they're called short range and +long range guidance + + align:start position:0% +long range guidance + + + align:start position:0% +long range guidance +signals short range + + align:start position:0% + + + + align:start position:0% + +signals require contact between the axon + + align:start position:0% +signals require contact between the axon + + + align:start position:0% +signals require contact between the axon +and the extracellular Matrix or the axon + + align:start position:0% +and the extracellular Matrix or the axon + + + align:start position:0% +and the extracellular Matrix or the axon +and another cell so there's some + + align:start position:0% +and another cell so there's some + + + align:start position:0% +and another cell so there's some +localized accumulation of a signal + + align:start position:0% +localized accumulation of a signal + + + align:start position:0% +localized accumulation of a signal +signal and that has to be um directly + + align:start position:0% +signal and that has to be um directly + + + align:start position:0% +signal and that has to be um directly +contacted between by the growth cones so + + align:start position:0% +contacted between by the growth cones so + + + align:start position:0% +contacted between by the growth cones so +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +require + + align:start position:0% +require + + + align:start position:0% +require +axon + + align:start position:0% +axon + + + align:start position:0% +axon +ECM or cell + + align:start position:0% + + + + align:start position:0% + +contact these + + align:start position:0% +contact these + + + align:start position:0% +contact these +signals are not + + align:start position:0% + + + + align:start position:0% + +diffusible + + align:start position:0% +diffusible + + + align:start position:0% +diffusible +therefore and they include things like + + align:start position:0% +therefore and they include things like + + + align:start position:0% +therefore and they include things like +aminon which is a part of the + + align:start position:0% +aminon which is a part of the + + + align:start position:0% +aminon which is a part of the +extracellular Matrix but also an axon + + align:start position:0% +extracellular Matrix but also an axon + + + align:start position:0% +extracellular Matrix but also an axon +guidance signal and then there are long + + align:start position:0% +guidance signal and then there are long + + + align:start position:0% +guidance signal and then there are long +range + + align:start position:0% + + + + align:start position:0% + +signals which would be the flip of the + + align:start position:0% +signals which would be the flip of the + + + align:start position:0% +signals which would be the flip of the +short range these are + + align:start position:0% + + + + align:start position:0% + +diffusible and they can be concentration + + align:start position:0% +diffusible and they can be concentration + + + align:start position:0% +diffusible and they can be concentration +dependent in their + + align:start position:0% + + + + align:start position:0% + +effect and we talked about things like + + align:start position:0% +effect and we talked about things like + + + align:start position:0% +effect and we talked about things like +this previously when we talked about + + align:start position:0% +this previously when we talked about + + + align:start position:0% +this previously when we talked about +morphogens other lians that can act at + + align:start position:0% +morphogens other lians that can act at + + + align:start position:0% +morphogens other lians that can act at +different concentrations in different + + align:start position:0% +different concentrations in different + + + align:start position:0% +different concentrations in different +ways okay and an example that I'll + + align:start position:0% +ways okay and an example that I'll + + + align:start position:0% +ways okay and an example that I'll +Explore More with you is the netron + + align:start position:0% + + + + align:start position:0% + +protein all right let me see what I have + + align:start position:0% +protein all right let me see what I have + + + align:start position:0% +protein all right let me see what I have +here okay this is nice this is on your + + align:start position:0% +here okay this is nice this is on your + + + align:start position:0% +here okay this is nice this is on your +this is your next handout and this is an + + align:start position:0% +this is your next handout and this is an + + + align:start position:0% +this is your next handout and this is an +assay for short range guidance signals + + align:start position:0% +assay for short range guidance signals + + + align:start position:0% +assay for short range guidance signals +it's called a stripe assay and this was + + align:start position:0% +it's called a stripe assay and this was + + + align:start position:0% +it's called a stripe assay and this was +how it was found what those nasal and re + + align:start position:0% +how it was found what those nasal and re + + + align:start position:0% +how it was found what those nasal and re +those nasal and temporal retinal neurons + + align:start position:0% +those nasal and temporal retinal neurons + + + align:start position:0% +those nasal and temporal retinal neurons +grew on the idea is you take a plastic + + align:start position:0% +grew on the idea is you take a plastic + + + align:start position:0% +grew on the idea is you take a plastic +dish and you put stripes of different + + align:start position:0% +dish and you put stripes of different + + + align:start position:0% +dish and you put stripes of different +molecules on the dish and then you put + + align:start position:0% +molecules on the dish and then you put + + + align:start position:0% +molecules on the dish and then you put +neurons all the way along one side of + + align:start position:0% +neurons all the way along one side of + + + align:start position:0% +neurons all the way along one side of +the dish and you look at them you ask + + align:start position:0% +the dish and you look at them you ask + + + align:start position:0% +the dish and you look at them you ask +where they grow and they'll choose where + + align:start position:0% +where they grow and they'll choose where + + + align:start position:0% +where they grow and they'll choose where +to grow and if they like one of the + + align:start position:0% +to grow and if they like one of the + + + align:start position:0% +to grow and if they like one of the +molecules if they can interact with one + + align:start position:0% +molecules if they can interact with one + + + align:start position:0% +molecules if they can interact with one +of the molecules on the dish they will + + align:start position:0% +of the molecules on the dish they will + + + align:start position:0% +of the molecules on the dish they will +grow in particular stripes and not in + + align:start position:0% +grow in particular stripes and not in + + + align:start position:0% +grow in particular stripes and not in +other stripes and that gives you your + + align:start position:0% +other stripes and that gives you your + + + align:start position:0% +other stripes and that gives you your +experiment and control in one dish this + + align:start position:0% +experiment and control in one dish this + + + align:start position:0% +experiment and control in one dish this +is what it looks like so here are the + + align:start position:0% +is what it looks like so here are the + + + align:start position:0% +is what it looks like so here are the +neurons from the nasal side of the + + align:start position:0% +neurons from the nasal side of the + + + align:start position:0% +neurons from the nasal side of the +retina and those nasal neurons which + + align:start position:0% +retina and those nasal neurons which + + + align:start position:0% +retina and those nasal neurons which +project to the r side of the tectum grow + + align:start position:0% +project to the r side of the tectum grow + + + align:start position:0% +project to the r side of the tectum grow +on R membranes but not on C membranes + + align:start position:0% +on R membranes but not on C membranes + + + align:start position:0% +on R membranes but not on C membranes +which is where they don't go you may not + + align:start position:0% +which is where they don't go you may not + + + align:start position:0% +which is where they don't go you may not +have this but you can go back and look + + align:start position:0% +have this but you can go back and look + + + align:start position:0% +have this but you can go back and look +at this later on all + + align:start position:0% +at this later on all + + + align:start position:0% +at this later on all +right but let's move on now to an + + align:start position:0% +right but let's move on now to an + + + align:start position:0% +right but let's move on now to an +example that I want to spend a bit of + + align:start position:0% +example that I want to spend a bit of + + + align:start position:0% +example that I want to spend a bit of +time on and the + + align:start position:0% +time on and the + + + align:start position:0% +time on and the +example of a long range signal is + + align:start position:0% +example of a long range signal is + + + align:start position:0% +example of a long range signal is +netron in the spinal + + align:start position:0% + + + + align:start position:0% + +cord and what we're going to talk about + + align:start position:0% +cord and what we're going to talk about + + + align:start position:0% +cord and what we're going to talk about +are two types of neurons one of which + + align:start position:0% +are two types of neurons one of which + + + align:start position:0% +are two types of neurons one of which +are growing down the spine spinal cord + + align:start position:0% +are growing down the spine spinal cord + + + align:start position:0% +are growing down the spine spinal cord +from the back more towards the belly and + + align:start position:0% +from the back more towards the belly and + + + align:start position:0% +from the back more towards the belly and +another type of neuron that's growing + + align:start position:0% +another type of neuron that's growing + + + align:start position:0% +another type of neuron that's growing +more from the belly side of the spinal + + align:start position:0% +more from the belly side of the spinal + + + align:start position:0% +more from the belly side of the spinal +cord back towards the back okay and + + align:start position:0% +cord back towards the back okay and + + + align:start position:0% +cord back towards the back okay and +those neurons always know where to go + + align:start position:0% +those neurons always know where to go + + + align:start position:0% +those neurons always know where to go +and it turns out they are told where to + + align:start position:0% +and it turns out they are told where to + + + align:start position:0% +and it turns out they are told where to +go by the same signal so there are two + + align:start position:0% +go by the same signal so there are two + + + align:start position:0% +go by the same signal so there are two +types of neurons there are + + align:start position:0% +types of neurons there are + + + align:start position:0% +types of neurons there are +um these things called + + align:start position:0% +um these things called + + + align:start position:0% +um these things called +cheral neurons + + align:start position:0% + + + + align:start position:0% + +and they + + align:start position:0% +and they + + + align:start position:0% +and they +grow + + align:start position:0% +grow + + + align:start position:0% +grow +ventrally or + + align:start position:0% +ventrally or + + + align:start position:0% +ventrally or +down towards something called the floor + + align:start position:0% +down towards something called the floor + + + align:start position:0% +down towards something called the floor +plate I'll show you in the + + align:start position:0% +plate I'll show you in the + + + align:start position:0% +plate I'll show you in the +diagram and then there these other ones + + align:start position:0% +diagram and then there these other ones + + + align:start position:0% +diagram and then there these other ones +called trar + + align:start position:0% +called trar + + + align:start position:0% +called trar +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +neurons that grow + + align:start position:0% +neurons that grow + + + align:start position:0% +neurons that grow +dorsally or + + align:start position:0% +dorsally or + + + align:start position:0% +dorsally or +up and they grow away from this thing + + align:start position:0% +up and they grow away from this thing + + + align:start position:0% +up and they grow away from this thing +called the floor plate and it turns out + + align:start position:0% +called the floor plate and it turns out + + + align:start position:0% +called the floor plate and it turns out +using an xplant assay that I'll go + + align:start position:0% +using an xplant assay that I'll go + + + align:start position:0% +using an xplant assay that I'll go +through with you in your slides but you + + align:start position:0% +through with you in your slides but you + + + align:start position:0% +through with you in your slides but you +should + + align:start position:0% +should + + + align:start position:0% +should +understand it was found that a single + + align:start position:0% +understand it was found that a single + + + align:start position:0% +understand it was found that a single +molecule called + + align:start position:0% + + + + align:start position:0% + +netron which is a secreted liand a + + align:start position:0% +netron which is a secreted liand a + + + align:start position:0% +netron which is a secreted liand a +secreted + + align:start position:0% + + + + align:start position:0% + +Protein that's expressed in the floor + + align:start position:0% +Protein that's expressed in the floor + + + align:start position:0% +Protein that's expressed in the floor +plate + + align:start position:0% + + + + align:start position:0% + +which we'll talk about in a + + align:start position:0% +which we'll talk about in a + + + align:start position:0% +which we'll talk about in a +moment is + + align:start position:0% + + + + align:start position:0% + +attractive for the cheral + + align:start position:0% + + + + align:start position:0% + +neurons and + + align:start position:0% +neurons and + + + align:start position:0% +neurons and +repulsive for the trar neurons + + align:start position:0% + + + + align:start position:0% + +and it also turns out as we'll go + + align:start position:0% +and it also turns out as we'll go + + + align:start position:0% +and it also turns out as we'll go +through in a moment that this has to do + + align:start position:0% +through in a moment that this has to do + + + align:start position:0% +through in a moment that this has to do +with different receptors and different + + align:start position:0% +with different receptors and different + + + align:start position:0% +with different receptors and different +receptor diers which bind the same liand + + align:start position:0% +receptor diers which bind the same liand + + + align:start position:0% +receptor diers which bind the same liand +and so here there is something called + + align:start position:0% +and so here there is something called + + + align:start position:0% +and so here there is something called +for the cissal neurons there's something + + align:start position:0% +for the cissal neurons there's something + + + align:start position:0% +for the cissal neurons there's something +called a + + align:start position:0% +called a + + + align:start position:0% +called a +DCC + + align:start position:0% +DCC + + + align:start position:0% +DCC +DCC + + align:start position:0% + + + + align:start position:0% + +recepto and for the tro neurons there is + + align:start position:0% +recepto and for the tro neurons there is + + + align:start position:0% +recepto and for the tro neurons there is +a DC + + align:start position:0% +a DC + + + align:start position:0% +a DC +C Unk + + align:start position:0% +C Unk + + + align:start position:0% +C Unk +five receptor pair and this will not + + align:start position:0% +five receptor pair and this will not + + + align:start position:0% +five receptor pair and this will not +mean much to you but now you can write + + align:start position:0% +mean much to you but now you can write + + + align:start position:0% +mean much to you but now you can write +it down and then you can go through your + + align:start position:0% +it down and then you can go through your + + + align:start position:0% +it down and then you can go through your +slides and you'll have a reference point + + align:start position:0% +slides and you'll have a reference point + + + align:start position:0% +slides and you'll have a reference point +on right with you okay so here is the + + align:start position:0% +on right with you okay so here is the + + + align:start position:0% +on right with you okay so here is the +diagram the cell bodies of the cheral + + align:start position:0% +diagram the cell bodies of the cheral + + + align:start position:0% +diagram the cell bodies of the cheral +neurons are up in near this region of + + align:start position:0% +neurons are up in near this region of + + + align:start position:0% +neurons are up in near this region of +the spinal cord called the roof plate + + align:start position:0% +the spinal cord called the roof plate + + + align:start position:0% +the spinal cord called the roof plate +it's the top of the spinal cord + + align:start position:0% +it's the top of the spinal cord + + + align:start position:0% +it's the top of the spinal cord +and on the bottom of the spinal cord + + align:start position:0% +and on the bottom of the spinal cord + + + align:start position:0% +and on the bottom of the spinal cord +near your belly there's a kind of a + + align:start position:0% +near your belly there's a kind of a + + + align:start position:0% +near your belly there's a kind of a +cone-shaped group of cells that forms + + align:start position:0% +cone-shaped group of cells that forms + + + align:start position:0% +cone-shaped group of cells that forms +this thing called the floor plate the + + align:start position:0% +this thing called the floor plate the + + + align:start position:0% +this thing called the floor plate the +floor plate doesn't actually make + + align:start position:0% +floor plate doesn't actually make + + + align:start position:0% +floor plate doesn't actually make +neurons it turns out to be a really + + align:start position:0% +neurons it turns out to be a really + + + align:start position:0% +neurons it turns out to be a really +important source of signals it's an + + align:start position:0% +important source of signals it's an + + + align:start position:0% +important source of signals it's an +organizer if you like and it not only + + align:start position:0% +organizer if you like and it not only + + + align:start position:0% +organizer if you like and it not only +organizes these axons in the spinal cord + + align:start position:0% +organizes these axons in the spinal cord + + + align:start position:0% +organizes these axons in the spinal cord +it actually also organizes your midline + + align:start position:0% +it actually also organizes your midline + + + align:start position:0% +it actually also organizes your midline +and it's one of the reasons if you're + + align:start position:0% +and it's one of the reasons if you're + + + align:start position:0% +and it's one of the reasons if you're +missing the midline of the body things + + align:start position:0% +missing the midline of the body things + + + align:start position:0% +missing the midline of the body things +go wrong it's because the floor plates + + align:start position:0% +go wrong it's because the floor plates + + + align:start position:0% +go wrong it's because the floor plates +not there so the floor Plate's an + + align:start position:0% +not there so the floor Plate's an + + + align:start position:0% +not there so the floor Plate's an +organizer there the cheral neurons + + align:start position:0% +organizer there the cheral neurons + + + align:start position:0% +organizer there the cheral neurons +growing towards it and here are the tro + + align:start position:0% +growing towards it and here are the tro + + + align:start position:0% +growing towards it and here are the tro +neurons growing away from the floor + + align:start position:0% +neurons growing away from the floor + + + align:start position:0% +neurons growing away from the floor +plate this is what it looks like if you + + align:start position:0% +plate this is what it looks like if you + + + align:start position:0% +plate this is what it looks like if you +do an imuno stain the cell bodies are in + + align:start position:0% +do an imuno stain the cell bodies are in + + + align:start position:0% +do an imuno stain the cell bodies are in +red and here are the cheral neurons + + align:start position:0% +red and here are the cheral neurons + + + align:start position:0% +red and here are the cheral neurons +coming down in the spinal cord and this + + align:start position:0% +coming down in the spinal cord and this + + + align:start position:0% +coming down in the spinal cord and this +is a section through the spinal cord + + align:start position:0% +is a section through the spinal cord + + + align:start position:0% +is a section through the spinal cord +okay you've cut through cut through at + + align:start position:0% +okay you've cut through cut through at + + + align:start position:0% +okay you've cut through cut through at +the waist and then turned the section on + + align:start position:0% +the waist and then turned the section on + + + align:start position:0% +the waist and then turned the section on +its side so you're looking into the + + align:start position:0% +its side so you're looking into the + + + align:start position:0% +its side so you're looking into the +spinal cord which would be coming out in + + align:start position:0% +spinal cord which would be coming out in + + + align:start position:0% +spinal cord which would be coming out in +its length from the board from the + + align:start position:0% +its length from the board from the + + + align:start position:0% +its length from the board from the +screen all right here's an explant assay + + align:start position:0% +screen all right here's an explant assay + + + align:start position:0% +screen all right here's an explant assay +to figure out whether or not that floor + + align:start position:0% +to figure out whether or not that floor + + + align:start position:0% +to figure out whether or not that floor +plate has got something to do with the + + align:start position:0% +plate has got something to do with the + + + align:start position:0% +plate has got something to do with the +direction that those cissal neurons grow + + align:start position:0% +direction that those cissal neurons grow + + + align:start position:0% +direction that those cissal neurons grow +it's on your + + align:start position:0% +it's on your + + + align:start position:0% +it's on your +handout the idea was to take a piece of + + align:start position:0% +handout the idea was to take a piece of + + + align:start position:0% +handout the idea was to take a piece of +dorsal spinal cord that hadn't started + + align:start position:0% +dorsal spinal cord that hadn't started + + + align:start position:0% +dorsal spinal cord that hadn't started +to send neurons out yet and to culture + + align:start position:0% +to send neurons out yet and to culture + + + align:start position:0% +to send neurons out yet and to culture +it together in the laboratory in a + + align:start position:0% +it together in the laboratory in a + + + align:start position:0% +it together in the laboratory in a +plastic dish with some with some fluid + + align:start position:0% +plastic dish with some with some fluid + + + align:start position:0% +plastic dish with some with some fluid +and nutrients and so on and ask what + + align:start position:0% +and nutrients and so on and ask what + + + align:start position:0% +and nutrients and so on and ask what +happened and if you did that that dorsal + + align:start position:0% +happened and if you did that that dorsal + + + align:start position:0% +happened and if you did that that dorsal +spinal cord sent out neurons towards the + + align:start position:0% +spinal cord sent out neurons towards the + + + align:start position:0% +spinal cord sent out neurons towards the +floor + + align:start position:0% +floor + + + align:start position:0% +floor +plate on the other hand you could see + + align:start position:0% +plate on the other hand you could see + + + align:start position:0% +plate on the other hand you could see +that that experiment was specific + + align:start position:0% +that that experiment was specific + + + align:start position:0% +that that experiment was specific +because if you put the dorsal spinal + + align:start position:0% +because if you put the dorsal spinal + + + align:start position:0% +because if you put the dorsal spinal +cord together with some roof plate + + align:start position:0% +cord together with some roof plate + + + align:start position:0% +cord together with some roof plate +nothing happened there was no outgrowth + + align:start position:0% +nothing happened there was no outgrowth + + + align:start position:0% +nothing happened there was no outgrowth +so there was something special about + + align:start position:0% +so there was something special about + + + align:start position:0% +so there was something special about +this floor plate that elicited that + + align:start position:0% +this floor plate that elicited that + + + align:start position:0% +this floor plate that elicited that +cheral axon outgrowth and the idea idea + + align:start position:0% +cheral axon outgrowth and the idea idea + + + align:start position:0% +cheral axon outgrowth and the idea idea +is that the floor plate was attracting + + align:start position:0% +is that the floor plate was attracting + + + align:start position:0% +is that the floor plate was attracting +the cheral + + align:start position:0% +the cheral + + + align:start position:0% +the cheral +axons this is what it really looks like + + align:start position:0% +axons this is what it really looks like + + + align:start position:0% +axons this is what it really looks like +here's a chunk of dorsal spinal cord and + + align:start position:0% +here's a chunk of dorsal spinal cord and + + + align:start position:0% +here's a chunk of dorsal spinal cord and +floor plate and here are the growing + + align:start position:0% +floor plate and here are the growing + + + align:start position:0% +floor plate and here are the growing +axons and here's the control + + align:start position:0% +axons and here's the control + + + align:start position:0% +axons and here's the control +experiment all right so what is the + + align:start position:0% +experiment all right so what is the + + + align:start position:0% +experiment all right so what is the +protein involved well the idea was that + + align:start position:0% +protein involved well the idea was that + + + align:start position:0% +protein involved well the idea was that +it was something in the floor plate and + + align:start position:0% +it was something in the floor plate and + + + align:start position:0% +it was something in the floor plate and +it was really hard to find this because + + align:start position:0% +it was really hard to find this because + + + align:start position:0% +it was really hard to find this because +there's not much of it Professor Tessier + + align:start position:0% +there's not much of it Professor Tessier + + + align:start position:0% +there's not much of it Professor Tessier +LaVine who is now president of + + align:start position:0% +LaVine who is now president of + + + align:start position:0% +LaVine who is now president of +Rockefeller University but at the time + + align:start position:0% +Rockefeller University but at the time + + + align:start position:0% +Rockefeller University but at the time +time was running a research laboratory + + align:start position:0% +time was running a research laboratory + + + align:start position:0% +time was running a research laboratory +and he and many undergraduates and + + align:start position:0% +and he and many undergraduates and + + + align:start position:0% +and he and many undergraduates and +graduate students and postdocs and so on + + align:start position:0% +graduate students and postdocs and so on + + + align:start position:0% +graduate students and postdocs and so on +went ahead and dissected many many + + align:start position:0% +went ahead and dissected many many + + + align:start position:0% +went ahead and dissected many many +little floor plates and they also found + + align:start position:0% +little floor plates and they also found + + + align:start position:0% +little floor plates and they also found +that the brain of the chicken contained + + align:start position:0% +that the brain of the chicken contained + + + align:start position:0% +that the brain of the chicken contained +the same kind of activity so they + + align:start position:0% +the same kind of activity so they + + + align:start position:0% +the same kind of activity so they +dissected out many thousands I believe + + align:start position:0% +dissected out many thousands I believe + + + align:start position:0% +dissected out many thousands I believe +it was + + align:start position:0% +it was + + + align:start position:0% +it was +35,000 chick brains and spinal cords and + + align:start position:0% +35,000 chick brains and spinal cords and + + + align:start position:0% +35,000 chick brains and spinal cords and +they did biochemistry on this material + + align:start position:0% +they did biochemistry on this material + + + align:start position:0% +they did biochemistry on this material +and they used the xplant essay that I + + align:start position:0% +and they used the xplant essay that I + + + align:start position:0% +and they used the xplant essay that I +just showed you you where instead of the + + align:start position:0% +just showed you you where instead of the + + + align:start position:0% +just showed you you where instead of the +floor plate you'd have a little pallet + + align:start position:0% +floor plate you'd have a little pallet + + + align:start position:0% +floor plate you'd have a little pallet +of material in which you'd soaked the + + align:start position:0% +of material in which you'd soaked the + + + align:start position:0% +of material in which you'd soaked the +material that you purified by + + align:start position:0% +material that you purified by + + + align:start position:0% +material that you purified by +biochemistry from your shushed up + + align:start position:0% +biochemistry from your shushed up + + + align:start position:0% +biochemistry from your shushed up +dissected brains and from this it was + + align:start position:0% +dissected brains and from this it was + + + align:start position:0% +dissected brains and from this it was +really successful from this they got a + + align:start position:0% +really successful from this they got a + + + align:start position:0% +really successful from this they got a +single protein here's the RNA for the + + align:start position:0% +single protein here's the RNA for the + + + align:start position:0% +single protein here's the RNA for the +Protein that's right expressed in the + + align:start position:0% +Protein that's right expressed in the + + + align:start position:0% +Protein that's right expressed in the +floor plate that's what the white is + + align:start position:0% +floor plate that's what the white is + + + align:start position:0% +floor plate that's what the white is +that's the RNA this is an incu + + align:start position:0% +that's the RNA this is an incu + + + align:start position:0% +that's the RNA this is an incu +hybridization and they called it netrin + + align:start position:0% +hybridization and they called it netrin + + + align:start position:0% +hybridization and they called it netrin +netrin protein diffuses away from the + + align:start position:0% +netrin protein diffuses away from the + + + align:start position:0% +netrin protein diffuses away from the +the floor plate but it's still mostly on + + align:start position:0% +the floor plate but it's still mostly on + + + align:start position:0% +the floor plate but it's still mostly on +this ventral side of the spinal cord and + + align:start position:0% +this ventral side of the spinal cord and + + + align:start position:0% +this ventral side of the spinal cord and +you could show that netron was important + + align:start position:0% +you could show that netron was important + + + align:start position:0% +you could show that netron was important +because if you made a mouse that lacked + + align:start position:0% +because if you made a mouse that lacked + + + align:start position:0% +because if you made a mouse that lacked +netron here's the mouse that lacks + + align:start position:0% +netron here's the mouse that lacks + + + align:start position:0% +netron here's the mouse that lacks +netron the cheral neurons go all over + + align:start position:0% +netron the cheral neurons go all over + + + align:start position:0% +netron the cheral neurons go all over +the place they really don't know where + + align:start position:0% +the place they really don't know where + + + align:start position:0% +the place they really don't know where +to go all right The netron + + align:start position:0% +to go all right The netron + + + align:start position:0% +to go all right The netron +receptors as I drew on the board you can + + align:start position:0% +receptors as I drew on the board you can + + + align:start position:0% +receptors as I drew on the board you can +look on your last handout are twofold + + align:start position:0% + + + + align:start position:0% + +one of them are called DCC they're + + align:start position:0% +one of them are called DCC they're + + + align:start position:0% +one of them are called DCC they're +tyrosine + + align:start position:0% +tyrosine + + + align:start position:0% +tyrosine +kinases they also activate gtpases and + + align:start position:0% +kinases they also activate gtpases and + + + align:start position:0% +kinases they also activate gtpases and +do some other signal transduction and + + align:start position:0% +do some other signal transduction and + + + align:start position:0% +do some other signal transduction and +when netron binds to a dimer of + + align:start position:0% +when netron binds to a dimer of + + + align:start position:0% +when netron binds to a dimer of +DCC you get fum that's made micr tubules + + align:start position:0% +DCC you get fum that's made micr tubules + + + align:start position:0% +DCC you get fum that's made micr tubules +grow and the growth cone extends on the + + align:start position:0% +grow and the growth cone extends on the + + + align:start position:0% +grow and the growth cone extends on the +other hand when you get this + + align:start position:0% +other hand when you get this + + + align:start position:0% +other hand when you get this +heterodimer DCC and an5 or a different + + align:start position:0% +heterodimer DCC and an5 or a different + + + align:start position:0% +heterodimer DCC and an5 or a different +homodimer you you get cytoskeletal + + align:start position:0% +homodimer you you get cytoskeletal + + + align:start position:0% +homodimer you you get cytoskeletal +remodeling gacon made and the growth + + align:start position:0% +remodeling gacon made and the growth + + + align:start position:0% +remodeling gacon made and the growth +cone + + align:start position:0% +cone + + + align:start position:0% +cone +collapses okay close enough we'll stop + + align:start position:0% + + + + align:start position:0% + +there for \ No newline at end of file diff --git a/l1t2_5UZhPA.txt b/l1t2_5UZhPA.txt new file mode 100644 index 0000000000000000000000000000000000000000..12adbf073379daa128f3f935962cb9c0236d9fd1 --- /dev/null +++ b/l1t2_5UZhPA.txt @@ -0,0 +1,10771 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT OpenCourseWare continue to + + align:start position:0% +will help MIT OpenCourseWare continue to + + + align:start position:0% +will help MIT OpenCourseWare continue to +offer high quality educational resources + + align:start position:0% +offer high quality educational resources + + + align:start position:0% +offer high quality educational resources +for free + + align:start position:0% +for free + + + align:start position:0% +for free +to make a donation or view additional + + align:start position:0% +to make a donation or view additional + + + align:start position:0% +to make a donation or view additional +materials from hundreds of MIT courses + + align:start position:0% +materials from hundreds of MIT courses + + + align:start position:0% +materials from hundreds of MIT courses +visit MIT opencourseware at ocw.mit.edu + + align:start position:0% +visit MIT opencourseware at ocw.mit.edu + + + align:start position:0% +visit MIT opencourseware at ocw.mit.edu +I'm gonna be talking today about how + + align:start position:0% +I'm gonna be talking today about how + + + align:start position:0% +I'm gonna be talking today about how +infants and kids start to develop an + + align:start position:0% +infants and kids start to develop an + + + align:start position:0% +infants and kids start to develop an +understanding of communication and why + + align:start position:0% +understanding of communication and why + + + align:start position:0% +understanding of communication and why +this is an important topic for + + align:start position:0% +this is an important topic for + + + align:start position:0% +this is an important topic for +understanding human intelligence so what + + align:start position:0% +understanding human intelligence so what + + + align:start position:0% +understanding human intelligence so what +is communication so really basically + + align:start position:0% +is communication so really basically + + + align:start position:0% +is communication so really basically +communication is the transfer is a + + align:start position:0% +communication is the transfer is a + + + align:start position:0% +communication is the transfer is a +transfer or exchange of information and + + align:start position:0% +transfer or exchange of information and + + + align:start position:0% +transfer or exchange of information and +importantly in human communication this + + align:start position:0% +importantly in human communication this + + + align:start position:0% +importantly in human communication this +isn't just any kind of information but + + align:start position:0% +isn't just any kind of information but + + + align:start position:0% +isn't just any kind of information but +it's specifically the kind of + + align:start position:0% +it's specifically the kind of + + + align:start position:0% +it's specifically the kind of +information that's in our heads and in + + align:start position:0% +information that's in our heads and in + + + align:start position:0% +information that's in our heads and in +our minds so for example this + + align:start position:0% +our minds so for example this + + + align:start position:0% +our minds so for example this +information in my head right now that + + align:start position:0% +information in my head right now that + + + align:start position:0% +information in my head right now that +I'm going to be transferring to you over + + align:start position:0% +I'm going to be transferring to you over + + + align:start position:0% +I'm going to be transferring to you over +the course of this talk and the reason + + align:start position:0% +the course of this talk and the reason + + + align:start position:0% +the course of this talk and the reason +we need communication to do this and + + align:start position:0% +we need communication to do this and + + + align:start position:0% +we need communication to do this and +that we use it all the time + + align:start position:0% +that we use it all the time + + + align:start position:0% +that we use it all the time +is obviously that everyone has minds of + + align:start position:0% +is obviously that everyone has minds of + + + align:start position:0% +is obviously that everyone has minds of +their own and that we don't have access + + align:start position:0% +their own and that we don't have access + + + align:start position:0% +their own and that we don't have access +to the mental states of others and we + + align:start position:0% +to the mental states of others and we + + + align:start position:0% +to the mental states of others and we +can't automatically transfer our own + + align:start position:0% +can't automatically transfer our own + + + align:start position:0% +can't automatically transfer our own +mental states so there's without some + + align:start position:0% +mental states so there's without some + + + align:start position:0% +mental states so there's without some +means of making those mental states + + align:start position:0% +means of making those mental states + + + align:start position:0% +means of making those mental states +observable in the form of communicating + + align:start position:0% +observable in the form of communicating + + + align:start position:0% +observable in the form of communicating +with them so people are both cognitive + + align:start position:0% +with them so people are both cognitive + + + align:start position:0% +with them so people are both cognitive +beings we have to sort of navigate the + + align:start position:0% +beings we have to sort of navigate the + + + align:start position:0% +beings we have to sort of navigate the +thoughts in our heads and try to figure + + align:start position:0% +thoughts in our heads and try to figure + + + align:start position:0% +thoughts in our heads and try to figure +out the thoughts that our other's heads + + align:start position:0% +out the thoughts that our other's heads + + + align:start position:0% +out the thoughts that our other's heads +but we're also social beings we really + + align:start position:0% +but we're also social beings we really + + + align:start position:0% +but we're also social beings we really +benefit from gaining access to the + + align:start position:0% +benefit from gaining access to the + + + align:start position:0% +benefit from gaining access to the +thoughts and the minds of others and + + align:start position:0% +thoughts and the minds of others and + + + align:start position:0% +thoughts and the minds of others and +giving them access to our own thoughts + + align:start position:0% +giving them access to our own thoughts + + + align:start position:0% +giving them access to our own thoughts +so for example for cooperation + + align:start position:0% +so for example for cooperation + + + align:start position:0% +so for example for cooperation +competition learning and teaching and + + align:start position:0% +competition learning and teaching and + + + align:start position:0% +competition learning and teaching and +all the kinds of social interactions we + + align:start position:0% +all the kinds of social interactions we + + + align:start position:0% +all the kinds of social interactions we +do with each other we have to be able to + + align:start position:0% +do with each other we have to be able to + + + align:start position:0% +do with each other we have to be able to +share the contents of our mental states + + align:start position:0% +share the contents of our mental states + + + align:start position:0% +share the contents of our mental states +and it's this sort of joint both + + align:start position:0% +and it's this sort of joint both + + + align:start position:0% +and it's this sort of joint both +cognitive and social nature of + + align:start position:0% +cognitive and social nature of + + + align:start position:0% +cognitive and social nature of +communication that I think makes it + + align:start position:0% +communication that I think makes it + + + align:start position:0% +communication that I think makes it +especially important for understanding + + align:start position:0% +especially important for understanding + + + align:start position:0% +especially important for understanding +the development of human intelligence + + align:start position:0% +the development of human intelligence + + + align:start position:0% +the development of human intelligence +it sort of Crosscut's a lot of these + + align:start position:0% +it sort of Crosscut's a lot of these + + + align:start position:0% +it sort of Crosscut's a lot of these +core knowledge domains that Liz talked + + align:start position:0% +core knowledge domains that Liz talked + + + align:start position:0% +core knowledge domains that Liz talked +about in her talk + + align:start position:0% +about in her talk + + + align:start position:0% +about in her talk +so human communication requires + + align:start position:0% +so human communication requires + + + align:start position:0% +so human communication requires +reasoning about others cognitive states + + align:start position:0% +reasoning about others cognitive states + + + align:start position:0% +reasoning about others cognitive states +so understanding what other's beliefs + + align:start position:0% +so understanding what other's beliefs + + + align:start position:0% +so understanding what other's beliefs +and desires and intentions are + + align:start position:0% +and desires and intentions are + + + align:start position:0% +and desires and intentions are +it also requires reasoning about social + + align:start position:0% +it also requires reasoning about social + + + align:start position:0% +it also requires reasoning about social +interaction so understanding that + + align:start position:0% +interaction so understanding that + + + align:start position:0% +interaction so understanding that +typically these kinds of thoughts and + + align:start position:0% +typically these kinds of thoughts and + + + align:start position:0% +typically these kinds of thoughts and +beliefs and intentions are not shared + + align:start position:0% +beliefs and intentions are not shared + + + align:start position:0% +beliefs and intentions are not shared +among different people everyone has + + align:start position:0% +among different people everyone has + + + align:start position:0% +among different people everyone has +their own that are unobservable and + + align:start position:0% +their own that are unobservable and + + + align:start position:0% +their own that are unobservable and +housed in their own heads but that in + + align:start position:0% +housed in their own heads but that in + + + align:start position:0% +housed in their own heads but that in +the context of a particular kind of + + align:start position:0% +the context of a particular kind of + + + align:start position:0% +the context of a particular kind of +social interaction these people can + + align:start position:0% +social interaction these people can + + + align:start position:0% +social interaction these people can +intentionally share their thoughts with + + align:start position:0% +intentionally share their thoughts with + + + align:start position:0% +intentionally share their thoughts with +each other + + align:start position:0% +each other + + + align:start position:0% +each other +and communication often involves + + align:start position:0% +and communication often involves + + + align:start position:0% +and communication often involves +reasoning about a third thing which is + + align:start position:0% +reasoning about a third thing which is + + + align:start position:0% +reasoning about a third thing which is +language or communicative signals + + align:start position:0% +language or communicative signals + + + align:start position:0% +language or communicative signals +outside of language as well and so I'm + + align:start position:0% +outside of language as well and so I'm + + + align:start position:0% +outside of language as well and so I'm +going to come back to this point at the + + align:start position:0% +going to come back to this point at the + + + align:start position:0% +going to come back to this point at the +end but all these types of reasoning are + + align:start position:0% +end but all these types of reasoning are + + + align:start position:0% +end but all these types of reasoning are +going to come up in the studies about + + align:start position:0% +going to come up in the studies about + + + align:start position:0% +going to come up in the studies about +infant communication that I described in + + align:start position:0% +infant communication that I described in + + + align:start position:0% +infant communication that I described in +the talk and so Liz talked about how + + align:start position:0% +the talk and so Liz talked about how + + + align:start position:0% +the talk and so Liz talked about how +infants start out with these coherent + + align:start position:0% +infants start out with these coherent + + + align:start position:0% +infants start out with these coherent +separate principle core knowledge + + align:start position:0% +separate principle core knowledge + + + align:start position:0% +separate principle core knowledge +systems that contain some limited + + align:start position:0% +systems that contain some limited + + + align:start position:0% +systems that contain some limited +representations for reasoning about the + + align:start position:0% +representations for reasoning about the + + + align:start position:0% +representations for reasoning about the +world and which kind of come together + + align:start position:0% +world and which kind of come together + + + align:start position:0% +world and which kind of come together +around the end of the first year so if + + align:start position:0% +around the end of the first year so if + + + align:start position:0% +around the end of the first year so if +we want to figure out how to build a + + align:start position:0% +we want to figure out how to build a + + + align:start position:0% +we want to figure out how to build a +model of how social cognitive + + align:start position:0% +model of how social cognitive + + + align:start position:0% +model of how social cognitive +development works we're going to need to + + align:start position:0% +development works we're going to need to + + + align:start position:0% +development works we're going to need to +understand how an infant starts to + + align:start position:0% +understand how an infant starts to + + + align:start position:0% +understand how an infant starts to +figure out using these the core + + align:start position:0% +figure out using these the core + + + align:start position:0% +figure out using these the core +knowledge that they have early in life + + align:start position:0% +knowledge that they have early in life + + + align:start position:0% +knowledge that they have early in life +the components of communication and also + + align:start position:0% +the components of communication and also + + + align:start position:0% +the components of communication and also +how these components come together so + + align:start position:0% +how these components come together so + + + align:start position:0% +how these components come together so +that infants can build a more complex + + align:start position:0% +that infants can build a more complex + + + align:start position:0% +that infants can build a more complex +causal model of communication like + + align:start position:0% +causal model of communication like + + + align:start position:0% +causal model of communication like +adults have so in it this is just to + + align:start position:0% +adults have so in it this is just to + + + align:start position:0% +adults have so in it this is just to +illustrate the points I'm making about + + align:start position:0% +illustrate the points I'm making about + + + align:start position:0% +illustrate the points I'm making about +the communicative situation so in any + + align:start position:0% +the communicative situation so in any + + + align:start position:0% +the communicative situation so in any +given communicative situation we can't + + align:start position:0% +given communicative situation we can't + + + align:start position:0% +given communicative situation we can't +just think about the words that are + + align:start position:0% +just think about the words that are + + + align:start position:0% +just think about the words that are +being said or what we're hearing we need + + align:start position:0% +being said or what we're hearing we need + + + align:start position:0% +being said or what we're hearing we need +to think about it in this broader + + align:start position:0% +to think about it in this broader + + + align:start position:0% +to think about it in this broader +context of having a communicator or + + align:start position:0% +context of having a communicator or + + + align:start position:0% +context of having a communicator or +maybe multiple communicators an + + align:start position:0% +maybe multiple communicators an + + + align:start position:0% +maybe multiple communicators an +addressee or an audience and also the + + align:start position:0% +addressee or an audience and also the + + + align:start position:0% +addressee or an audience and also the +things that the communicator saying and + + align:start position:0% +things that the communicator saying and + + + align:start position:0% +things that the communicator saying and +the broader context that allow us to + + align:start position:0% +the broader context that allow us to + + + align:start position:0% +the broader context that allow us to +figure out what's going on in this + + align:start position:0% +figure out what's going on in this + + + align:start position:0% +figure out what's going on in this +social interaction so it really requires + + align:start position:0% +social interaction so it really requires + + + align:start position:0% +social interaction so it really requires +understanding that the communicators + + align:start position:0% +understanding that the communicators + + + align:start position:0% +understanding that the communicators +mental states are being transferred in + + align:start position:0% +mental states are being transferred in + + + align:start position:0% +mental states are being transferred in +this causal way to the mind of the + + align:start position:0% +this causal way to the mind of the + + + align:start position:0% +this causal way to the mind of the +addressee so I'm going to structure the + + align:start position:0% +addressee so I'm going to structure the + + + align:start position:0% +addressee so I'm going to structure the +talk in terms of some important insights + + align:start position:0% +talk in terms of some important insights + + + align:start position:0% +talk in terms of some important insights +from the philosophy of human language + + align:start position:0% +from the philosophy of human language + + + align:start position:0% +from the philosophy of human language +and communication that I think have + + align:start position:0% +and communication that I think have + + + align:start position:0% +and communication that I think have +really guided the way we have the way + + align:start position:0% +really guided the way we have the way + + + align:start position:0% +really guided the way we have the way +researchers in the last say 50 years + + align:start position:0% +researchers in the last say 50 years + + + align:start position:0% +researchers in the last say 50 years +have been thinking about the development + + align:start position:0% +have been thinking about the development + + + align:start position:0% +have been thinking about the development +of human communication as well so I'm + + align:start position:0% +of human communication as well so I'm + + + align:start position:0% +of human communication as well so I'm +gonna broadly illustrate the three + + align:start position:0% +gonna broadly illustrate the three + + + align:start position:0% +gonna broadly illustrate the three +points that I'm taking from each and + + align:start position:0% +points that I'm taking from each and + + + align:start position:0% +points that I'm taking from each and +then I'll expand on them in each section + + align:start position:0% +then I'll expand on them in each section + + + align:start position:0% +then I'll expand on them in each section +so the first insight that I think is + + align:start position:0% +so the first insight that I think is + + + align:start position:0% +so the first insight that I think is +really important for understanding how + + align:start position:0% +really important for understanding how + + + align:start position:0% +really important for understanding how +we think about communication comes from + + align:start position:0% +we think about communication comes from + + + align:start position:0% +we think about communication comes from +John Austin who brought up the important + + align:start position:0% +John Austin who brought up the important + + + align:start position:0% +John Austin who brought up the important +point so before Austin people tended to + + align:start position:0% +point so before Austin people tended to + + + align:start position:0% +point so before Austin people tended to +think about language or study language a + + align:start position:0% +think about language or study language a + + + align:start position:0% +think about language or study language a +lot in terms of language itself in this + + align:start position:0% +lot in terms of language itself in this + + + align:start position:0% +lot in terms of language itself in this +semantics and syntax and just the + + align:start position:0% +semantics and syntax and just the + + + align:start position:0% +semantics and syntax and just the +language signal but Austin pointed out + + align:start position:0% +language signal but Austin pointed out + + + align:start position:0% +language signal but Austin pointed out +that language is actually not just + + align:start position:0% +that language is actually not just + + + align:start position:0% +that language is actually not just +about the content but it's also in + + align:start position:0% +about the content but it's also in + + + align:start position:0% +about the content but it's also in +action it's actually something that we + + align:start position:0% +action it's actually something that we + + + align:start position:0% +action it's actually something that we +use and that we we do things with it in + + align:start position:0% +use and that we we do things with it in + + + align:start position:0% +use and that we we do things with it in +the same way that we do things and + + align:start position:0% +the same way that we do things and + + + align:start position:0% +the same way that we do things and +accomplish things in the world using + + align:start position:0% +accomplish things in the world using + + + align:start position:0% +accomplish things in the world using +other kinds of actions that we engage in + + align:start position:0% +other kinds of actions that we engage in + + + align:start position:0% +other kinds of actions that we engage in +so Austin's sort of brought up this + + align:start position:0% +so Austin's sort of brought up this + + + align:start position:0% +so Austin's sort of brought up this +important distinction that language is + + align:start position:0% +important distinction that language is + + + align:start position:0% +important distinction that language is +not just about the content so to + + align:start position:0% +not just about the content so to + + + align:start position:0% +not just about the content so to +illustrate with an example in this + + align:start position:0% +illustrate with an example in this + + + align:start position:0% +illustrate with an example in this +communicative interaction there's + + align:start position:0% +communicative interaction there's + + + align:start position:0% +communicative interaction there's +language here this person is saying is + + align:start position:0% +language here this person is saying is + + + align:start position:0% +language here this person is saying is +there any salt and Austin analyze this + + align:start position:0% +there any salt and Austin analyze this + + + align:start position:0% +there any salt and Austin analyze this +in terms of not only what the words + + align:start position:0% +in terms of not only what the words + + + align:start position:0% +in terms of not only what the words +meant but in terms of three layers of + + align:start position:0% +meant but in terms of three layers of + + + align:start position:0% +meant but in terms of three layers of +intentionality so in this simple + + align:start position:0% +intentionality so in this simple + + + align:start position:0% +intentionality so in this simple +interaction he pointed out that there's + + align:start position:0% +interaction he pointed out that there's + + + align:start position:0% +interaction he pointed out that there's +a locution airy Act or the meaning of + + align:start position:0% +a locution airy Act or the meaning of + + + align:start position:0% +a locution airy Act or the meaning of +the sentence which is that there's a + + align:start position:0% +the sentence which is that there's a + + + align:start position:0% +the sentence which is that there's a +question being asked about the presence + + align:start position:0% +question being asked about the presence + + + align:start position:0% +question being asked about the presence +of salt but that there's actually + + align:start position:0% +of salt but that there's actually + + + align:start position:0% +of salt but that there's actually +something else going on here as well + + align:start position:0% +something else going on here as well + + + align:start position:0% +something else going on here as well +which is that there's an illocutionary + + align:start position:0% +which is that there's an illocutionary + + + align:start position:0% +which is that there's an illocutionary +action which is what he considers to be + + align:start position:0% +action which is what he considers to be + + + align:start position:0% +action which is what he considers to be +sort of the intention underlying the + + align:start position:0% +sort of the intention underlying the + + + align:start position:0% +sort of the intention underlying the +action which is to request the salt so + + align:start position:0% +action which is to request the salt so + + + align:start position:0% +action which is to request the salt so +if you actually just read this sentence + + align:start position:0% +if you actually just read this sentence + + + align:start position:0% +if you actually just read this sentence +it it's kind of under determined it's + + align:start position:0% +it it's kind of under determined it's + + + align:start position:0% +it it's kind of under determined it's +not necessarily obvious that this + + align:start position:0% +not necessarily obvious that this + + + align:start position:0% +not necessarily obvious that this +person's asking the other person at this + + align:start position:0% +person's asking the other person at this + + + align:start position:0% +person's asking the other person at this +table to pass the salt but if you take + + align:start position:0% +table to pass the salt but if you take + + + align:start position:0% +table to pass the salt but if you take +it within the broader context of the + + align:start position:0% +it within the broader context of the + + + align:start position:0% +it within the broader context of the +interaction you can understand that + + align:start position:0% +interaction you can understand that + + + align:start position:0% +interaction you can understand that +what's really going on here is not just + + align:start position:0% +what's really going on here is not just + + + align:start position:0% +what's really going on here is not just +a sentence being produced but rather one + + align:start position:0% +a sentence being produced but rather one + + + align:start position:0% +a sentence being produced but rather one +individual requesting something from + + align:start position:0% +individual requesting something from + + + align:start position:0% +individual requesting something from +another who's then supposed to + + align:start position:0% +another who's then supposed to + + + align:start position:0% +another who's then supposed to +understand the request and in the third + + align:start position:0% +understand the request and in the third + + + align:start position:0% +understand the request and in the third +layer of analysis cause the addressee to + + align:start position:0% +layer of analysis cause the addressee to + + + align:start position:0% +layer of analysis cause the addressee to +provide the salt so the idea is that + + align:start position:0% +provide the salt so the idea is that + + + align:start position:0% +provide the salt so the idea is that +there are these multiple things going on + + align:start position:0% +there are these multiple things going on + + + align:start position:0% +there are these multiple things going on +in the context of a communicative + + align:start position:0% +in the context of a communicative + + + align:start position:0% +in the context of a communicative +interaction involving language the that + + align:start position:0% +interaction involving language the that + + + align:start position:0% +interaction involving language the that +sort of go beyond the words that are + + align:start position:0% +sort of go beyond the words that are + + + align:start position:0% +sort of go beyond the words that are +actually being spoken here and so if + + align:start position:0% +actually being spoken here and so if + + + align:start position:0% +actually being spoken here and so if +you're an infant + + align:start position:0% +you're an infant + + + align:start position:0% +you're an infant +just like in philosophy of language the + + align:start position:0% +just like in philosophy of language the + + + align:start position:0% +just like in philosophy of language the +focus in infant infant cognitive + + align:start position:0% +focus in infant infant cognitive + + + align:start position:0% +focus in infant infant cognitive +development also for a long time and + + align:start position:0% +development also for a long time and + + + align:start position:0% +development also for a long time and +still is we still need to understand + + align:start position:0% +still is we still need to understand + + + align:start position:0% +still is we still need to understand +these things is on was on understanding + + align:start position:0% +these things is on was on understanding + + + align:start position:0% +these things is on was on understanding +how infants learn words or how infants + + align:start position:0% +how infants learn words or how infants + + + align:start position:0% +how infants learn words or how infants +figure out the meaning of language and + + align:start position:0% +figure out the meaning of language and + + + align:start position:0% +figure out the meaning of language and +how it relates to objects in the + + align:start position:0% +how it relates to objects in the + + + align:start position:0% +how it relates to objects in the +environment and later to add the + + align:start position:0% +environment and later to add the + + + align:start position:0% +environment and later to add the +abstract concepts that language + + align:start position:0% +abstract concepts that language + + + align:start position:0% +abstract concepts that language +indicates but importantly understanding + + align:start position:0% +indicates but importantly understanding + + + align:start position:0% +indicates but importantly understanding +communication for an infant is going to + + align:start position:0% +communication for an infant is going to + + + align:start position:0% +communication for an infant is going to +be more than about just figuring out the + + align:start position:0% +be more than about just figuring out the + + + align:start position:0% +be more than about just figuring out the +meaning of these words and so following + + align:start position:0% +meaning of these words and so following + + + align:start position:0% +meaning of these words and so following +them the philosophical tradition of + + align:start position:0% +them the philosophical tradition of + + + align:start position:0% +them the philosophical tradition of +people like Austin who introduced the + + align:start position:0% +people like Austin who introduced the + + + align:start position:0% +people like Austin who introduced the +study of + + align:start position:0% +study of + + + align:start position:0% +study of +Mattox to language developmental + + align:start position:0% +Mattox to language developmental + + + align:start position:0% +Mattox to language developmental +psychologists as well started thinking + + align:start position:0% +psychologists as well started thinking + + + align:start position:0% +psychologists as well started thinking +about the importance of recognizing + + align:start position:0% +about the importance of recognizing + + + align:start position:0% +about the importance of recognizing +communication as this broader action in + + align:start position:0% +communication as this broader action in + + + align:start position:0% +communication as this broader action in +its context for understanding how + + align:start position:0% +its context for understanding how + + + align:start position:0% +its context for understanding how +infants come to be good communicators + + align:start position:0% +infants come to be good communicators + + + align:start position:0% +infants come to be good communicators +themselves so if communication involves + + align:start position:0% +themselves so if communication involves + + + align:start position:0% +themselves so if communication involves +this whole context of action and + + align:start position:0% +this whole context of action and + + + align:start position:0% +this whole context of action and +interaction between people if you're a + + align:start position:0% +interaction between people if you're a + + + align:start position:0% +interaction between people if you're a +baby who's in the business of + + align:start position:0% +baby who's in the business of + + + align:start position:0% +baby who's in the business of +understanding the social world the agent + + align:start position:0% +understanding the social world the agent + + + align:start position:0% +understanding the social world the agent +world in the world of language you're + + align:start position:0% +world in the world of language you're + + + align:start position:0% +world in the world of language you're +going to be well served by developing an + + align:start position:0% +going to be well served by developing an + + + align:start position:0% +going to be well served by developing an +ability to identify these kinds of + + align:start position:0% +ability to identify these kinds of + + + align:start position:0% +ability to identify these kinds of +communicative actions or situations and + + align:start position:0% +communicative actions or situations and + + + align:start position:0% +communicative actions or situations and +their components and to begin to + + align:start position:0% +their components and to begin to + + + align:start position:0% +their components and to begin to +understand how they work so how do + + align:start position:0% +understand how they work so how do + + + align:start position:0% +understand how they work so how do +infants start to figure out when + + align:start position:0% +infants start to figure out when + + + align:start position:0% +infants start to figure out when +communication is going on in the world + + align:start position:0% +communication is going on in the world + + + align:start position:0% +communication is going on in the world +around them rather than just identifying + + align:start position:0% +around them rather than just identifying + + + align:start position:0% +around them rather than just identifying +words and associating them with objects + + align:start position:0% +words and associating them with objects + + + align:start position:0% +words and associating them with objects +so actually there's a lot of evidence + + align:start position:0% +so actually there's a lot of evidence + + + align:start position:0% +so actually there's a lot of evidence +that infants are identifying key + + align:start position:0% +that infants are identifying key + + + align:start position:0% +that infants are identifying key +features of communicative situations + + align:start position:0% +features of communicative situations + + + align:start position:0% +features of communicative situations +really early in life so from the time + + align:start position:0% +really early in life so from the time + + + align:start position:0% +really early in life so from the time +they're born newborn human infants + + align:start position:0% +they're born newborn human infants + + + align:start position:0% +they're born newborn human infants +prefer listening to speech over other + + align:start position:0% +prefer listening to speech over other + + + align:start position:0% +prefer listening to speech over other +sounds so the typical method that's used + + align:start position:0% +sounds so the typical method that's used + + + align:start position:0% +sounds so the typical method that's used +to measure the preference of an infant + + align:start position:0% +to measure the preference of an infant + + + align:start position:0% +to measure the preference of an infant +who's only one to four days old is to + + align:start position:0% +who's only one to four days old is to + + + align:start position:0% +who's only one to four days old is to +have them suck on a pacifier that's + + align:start position:0% +have them suck on a pacifier that's + + + align:start position:0% +have them suck on a pacifier that's +connected to a machine that detects how + + align:start position:0% +connected to a machine that detects how + + + align:start position:0% +connected to a machine that detects how +strongly infants are sucking and then + + align:start position:0% +strongly infants are sucking and then + + + align:start position:0% +strongly infants are sucking and then +the sucking is used as a measure of + + align:start position:0% +the sucking is used as a measure of + + + align:start position:0% +the sucking is used as a measure of +infant's arousal upon hearing a + + align:start position:0% +infant's arousal upon hearing a + + + align:start position:0% +infant's arousal upon hearing a +particular sound or being exposed to a + + align:start position:0% +particular sound or being exposed to a + + + align:start position:0% +particular sound or being exposed to a +particular stimulus and so what + + align:start position:0% +particular stimulus and so what + + + align:start position:0% +particular stimulus and so what +researchers found is that if you have + + align:start position:0% +researchers found is that if you have + + + align:start position:0% +researchers found is that if you have +infants suck on this pacifier while + + align:start position:0% +infants suck on this pacifier while + + + align:start position:0% +infants suck on this pacifier while +listening to speech sound and norm + + align:start position:0% +listening to speech sound and norm + + + align:start position:0% +listening to speech sound and norm +speech sounds and alternation non-speech + + align:start position:0% +speech sounds and alternation non-speech + + + align:start position:0% +speech sounds and alternation non-speech +sounds being a sine wave produce sounds + + align:start position:0% +sounds being a sine wave produce sounds + + + align:start position:0% +sounds being a sine wave produce sounds +that are very similar to speech in their + + align:start position:0% +that are very similar to speech in their + + + align:start position:0% +that are very similar to speech in their +features if you listen to it has the + + align:start position:0% +features if you listen to it has the + + + align:start position:0% +features if you listen to it has the +prasada contours of speech and sounds a + + align:start position:0% +prasada contours of speech and sounds a + + + align:start position:0% +prasada contours of speech and sounds a +lot like it but it's not actually speech + + align:start position:0% +lot like it but it's not actually speech + + + align:start position:0% +lot like it but it's not actually speech +you can't understand you can't actually + + align:start position:0% +you can't understand you can't actually + + + align:start position:0% +you can't understand you can't actually +parse any words from it infants showed a + + align:start position:0% +parse any words from it infants showed a + + + align:start position:0% +parse any words from it infants showed a +preference for listening to speech over + + align:start position:0% +preference for listening to speech over + + + align:start position:0% +preference for listening to speech over +non speech or more arousal than they + + align:start position:0% +non speech or more arousal than they + + + align:start position:0% +non speech or more arousal than they +listen to speech they maintained their + + align:start position:0% +listen to speech they maintained their + + + align:start position:0% +listen to speech they maintained their +arousal for speech over the course of + + align:start position:0% +arousal for speech over the course of + + + align:start position:0% +arousal for speech over the course of +the experiment but for non speech it + + align:start position:0% +the experiment but for non speech it + + + align:start position:0% +the experiment but for non speech it +decline and so extremely early in life + + align:start position:0% +decline and so extremely early in life + + + align:start position:0% +decline and so extremely early in life +infants seem to have this bias for + + align:start position:0% +infants seem to have this bias for + + + align:start position:0% +infants seem to have this bias for +paying attention to the primary + + align:start position:0% +paying attention to the primary + + + align:start position:0% +paying attention to the primary +communicative signal of our species that + + align:start position:0% +communicative signal of our species that + + + align:start position:0% +communicative signal of our species that +is humans + + align:start position:0% + + + + align:start position:0% + +quite early in life as well infants + + align:start position:0% +quite early in life as well infants + + + align:start position:0% +quite early in life as well infants +recognize that speech recognize some of + + align:start position:0% +recognize that speech recognize some of + + + align:start position:0% +recognize that speech recognize some of +the important features of the social + + align:start position:0% +the important features of the social + + + align:start position:0% +the important features of the social +context surrounding speech so getting + + align:start position:0% +context surrounding speech so getting + + + align:start position:0% +context surrounding speech so getting +more into the domain of the important + + align:start position:0% +more into the domain of the important + + + align:start position:0% +more into the domain of the important +features for communication so by six + + align:start position:0% +features for communication so by six + + + align:start position:0% +features for communication so by six +months infants seem to recognize that + + align:start position:0% +months infants seem to recognize that + + + align:start position:0% +months infants seem to recognize that +speech is human produced or at least + + align:start position:0% +speech is human produced or at least + + + align:start position:0% +speech is human produced or at least +associate speech with other humans and + + align:start position:0% +associate speech with other humans and + + + align:start position:0% +associate speech with other humans and +also human directed so in one study + + align:start position:0% +also human directed so in one study + + + align:start position:0% +also human directed so in one study +infants saw pictures of human faces or + + align:start position:0% +infants saw pictures of human faces or + + + align:start position:0% +infants saw pictures of human faces or +faces of monkeys and they heard + + align:start position:0% +faces of monkeys and they heard + + + align:start position:0% +faces of monkeys and they heard +different sounds so they either heard it + + align:start position:0% +different sounds so they either heard it + + + align:start position:0% +different sounds so they either heard it +seems like that sound isn't on but + + align:start position:0% +seems like that sound isn't on but + + + align:start position:0% +seems like that sound isn't on but +that's okay + + align:start position:0% +that's okay + + + align:start position:0% +that's okay +so they either so they either heard a + + align:start position:0% +so they either so they either heard a + + + align:start position:0% +so they either so they either heard a +speech sound in a language they'd never + + align:start position:0% +speech sound in a language they'd never + + + align:start position:0% +speech sound in a language they'd never +heard before repeating itself or they + + align:start position:0% +heard before repeating itself or they + + + align:start position:0% +heard before repeating itself or they +heard a monkey call an infants in one + + align:start position:0% +heard a monkey call an infants in one + + + align:start position:0% +heard a monkey call an infants in one +trial either saw so in the first trial + + align:start position:0% +trial either saw so in the first trial + + + align:start position:0% +trial either saw so in the first trial +said they'd see the human face and then + + align:start position:0% +said they'd see the human face and then + + + align:start position:0% +said they'd see the human face and then +they could listen repeatedly to a speech + + align:start position:0% +they could listen repeatedly to a speech + + + align:start position:0% +they could listen repeatedly to a speech +sound until they looked away for two + + align:start position:0% +sound until they looked away for two + + + align:start position:0% +sound until they looked away for two +seconds and then they would see a monkey + + align:start position:0% +seconds and then they would see a monkey + + + align:start position:0% +seconds and then they would see a monkey +face and then they would hear either a + + align:start position:0% +face and then they would hear either a + + + align:start position:0% +face and then they would hear either a +speech under a monkey sound and be able + + align:start position:0% +speech under a monkey sound and be able + + + align:start position:0% +speech under a monkey sound and be able +to look at this image while listening to + + align:start position:0% +to look at this image while listening to + + + align:start position:0% +to look at this image while listening to +that sound until they looked away for + + align:start position:0% +that sound until they looked away for + + + align:start position:0% +that sound until they looked away for +two seconds and so they got all possible + + align:start position:0% +two seconds and so they got all possible + + + align:start position:0% +two seconds and so they got all possible +combinations sometimes they saw a human + + align:start position:0% +combinations sometimes they saw a human + + + align:start position:0% +combinations sometimes they saw a human +face and listen to speech sometimes they + + align:start position:0% +face and listen to speech sometimes they + + + align:start position:0% +face and listen to speech sometimes they +saw a human face and listen that the + + align:start position:0% +saw a human face and listen that the + + + align:start position:0% +saw a human face and listen that the +monkey sounds and sometimes they said + + align:start position:0% +monkey sounds and sometimes they said + + + align:start position:0% +monkey sounds and sometimes they said +the monkey face and listen to either + + align:start position:0% +the monkey face and listen to either + + + align:start position:0% +the monkey face and listen to either +human speech or the monkey sound and the + + align:start position:0% +human speech or the monkey sound and the + + + align:start position:0% +human speech or the monkey sound and the +idea and the question was whether + + align:start position:0% +idea and the question was whether + + + align:start position:0% +idea and the question was whether +infants could actually could match the + + align:start position:0% +infants could actually could match the + + + align:start position:0% +infants could actually could match the +speech sounds to humans and recognize + + align:start position:0% +speech sounds to humans and recognize + + + align:start position:0% +speech sounds to humans and recognize +that they should be produced by the + + align:start position:0% +that they should be produced by the + + + align:start position:0% +that they should be produced by the +human rather than the monkey and that's + + align:start position:0% +human rather than the monkey and that's + + + align:start position:0% +human rather than the monkey and that's +what they found so you can see that when + + align:start position:0% +what they found so you can see that when + + + align:start position:0% +what they found so you can see that when +infants heard speech they were much more + + align:start position:0% +infants heard speech they were much more + + + align:start position:0% +infants heard speech they were much more +likely to look at the yet they were + + align:start position:0% +likely to look at the yet they were + + + align:start position:0% +likely to look at the yet they were +looking at the human when they heard + + align:start position:0% +looking at the human when they heard + + + align:start position:0% +looking at the human when they heard +speech and then they were looking at the + + align:start position:0% +speech and then they were looking at the + + + align:start position:0% +speech and then they were looking at the +monkey when they heard the monkey calls + + align:start position:0% +monkey when they heard the monkey calls + + + align:start position:0% +monkey when they heard the monkey calls +I'm similarly infants seem to understand + + align:start position:0% +I'm similarly infants seem to understand + + + align:start position:0% +I'm similarly infants seem to understand +by six months that speech is directed at + + align:start position:0% +by six months that speech is directed at + + + align:start position:0% +by six months that speech is directed at +other humans so when they saw a person + + align:start position:0% +other humans so when they saw a person + + + align:start position:0% +other humans so when they saw a person +talking talking behind a barrier versus + + align:start position:0% +talking talking behind a barrier versus + + + align:start position:0% +talking talking behind a barrier versus +acting so sort of swiping with her hand + + align:start position:0% +acting so sort of swiping with her hand + + + align:start position:0% +acting so sort of swiping with her hand +behind a barrier and then the barrier + + align:start position:0% +behind a barrier and then the barrier + + + align:start position:0% +behind a barrier and then the barrier +was revealed to reveal either a person + + align:start position:0% +was revealed to reveal either a person + + + align:start position:0% +was revealed to reveal either a person +or an object infants look longer for the + + align:start position:0% +or an object infants look longer for the + + + align:start position:0% +or an object infants look longer for the +speaking familiarization when they saw + + align:start position:0% +speaking familiarization when they saw + + + align:start position:0% +speaking familiarization when they saw +that there had been an object behind the + + align:start position:0% +that there had been an object behind the + + + align:start position:0% +that there had been an object behind the +barrier than a person suggesting that + + align:start position:0% +barrier than a person suggesting that + + + align:start position:0% +barrier than a person suggesting that +they + + align:start position:0% +they + + + align:start position:0% +they +did speech to be directed towards + + align:start position:0% +did speech to be directed towards + + + align:start position:0% +did speech to be directed towards +another person and in contrast when they + + align:start position:0% +another person and in contrast when they + + + align:start position:0% +another person and in contrast when they +saw the person swiping they look much + + align:start position:0% +saw the person swiping they look much + + + align:start position:0% +saw the person swiping they look much +longer when they saw a person behind the + + align:start position:0% +longer when they saw a person behind the + + + align:start position:0% +longer when they saw a person behind the +barrier because typically we don't swipe + + align:start position:0% +barrier because typically we don't swipe + + + align:start position:0% +barrier because typically we don't swipe +it people we tend to speak to them so so + + align:start position:0% +it people we tend to speak to them so so + + + align:start position:0% +it people we tend to speak to them so so +this suggests that infants understand + + align:start position:0% +this suggests that infants understand + + + align:start position:0% +this suggests that infants understand +some of the features of the context in + + align:start position:0% +some of the features of the context in + + + align:start position:0% +some of the features of the context in +which communication in which human + + align:start position:0% +which communication in which human + + + align:start position:0% +which communication in which human +communication is produced importantly it + + align:start position:0% +communication is produced importantly it + + + align:start position:0% +communication is produced importantly it +infants do still seem to be developing + + align:start position:0% +infants do still seem to be developing + + + align:start position:0% +infants do still seem to be developing +this ability over the first year of life + + align:start position:0% +this ability over the first year of life + + + align:start position:0% +this ability over the first year of life +because it's not until ten months that + + align:start position:0% +because it's not until ten months that + + + align:start position:0% +because it's not until ten months that +they expect mutual gaze between speakers + + align:start position:0% +they expect mutual gaze between speakers + + + align:start position:0% +they expect mutual gaze between speakers +which tends to be important part of + + align:start position:0% +which tends to be important part of + + + align:start position:0% +which tends to be important part of +understanding the social context of + + align:start position:0% +understanding the social context of + + + align:start position:0% +understanding the social context of +communication so in this study infants + + align:start position:0% +communication so in this study infants + + + align:start position:0% +communication so in this study infants +saw two people facing each other this is + + align:start position:0% +saw two people facing each other this is + + + align:start position:0% +saw two people facing each other this is +just one of the experiments from the + + align:start position:0% +just one of the experiments from the + + + align:start position:0% +just one of the experiments from the +study but you can see that they saw the + + align:start position:0% +study but you can see that they saw the + + + align:start position:0% +study but you can see that they saw the +two people looking at each other and + + align:start position:0% +two people looking at each other and + + + align:start position:0% +two people looking at each other and +speaking to each other or the two people + + align:start position:0% +speaking to each other or the two people + + + align:start position:0% +speaking to each other or the two people +looking apart and speaking to each other + + align:start position:0% +looking apart and speaking to each other + + + align:start position:0% +looking apart and speaking to each other +and infants expected that infants at + + align:start position:0% +and infants expected that infants at + + + align:start position:0% +and infants expected that infants at +nine months didn't differentiate between + + align:start position:0% +nine months didn't differentiate between + + + align:start position:0% +nine months didn't differentiate between +these at all so at nine months they + + align:start position:0% +these at all so at nine months they + + + align:start position:0% +these at all so at nine months they +didn't necessarily think that the people + + align:start position:0% +didn't necessarily think that the people + + + align:start position:0% +didn't necessarily think that the people +were going to look at each other when + + align:start position:0% +were going to look at each other when + + + align:start position:0% +were going to look at each other when +they were speaking but at ten months you + + align:start position:0% +they were speaking but at ten months you + + + align:start position:0% +they were speaking but at ten months you +can see here the infants looked longer + + align:start position:0% +can see here the infants looked longer + + + align:start position:0% +can see here the infants looked longer +for the averted gaze than for the mutual + + align:start position:0% +for the averted gaze than for the mutual + + + align:start position:0% +for the averted gaze than for the mutual +gaze + + align:start position:0% + + + + align:start position:0% + +so infants seem to be able to recognize + + align:start position:0% +so infants seem to be able to recognize + + + align:start position:0% +so infants seem to be able to recognize +when a communicative context is going on + + align:start position:0% +when a communicative context is going on + + + align:start position:0% +when a communicative context is going on +early in life but we don't necessarily + + align:start position:0% +early in life but we don't necessarily + + + align:start position:0% +early in life but we don't necessarily +know from these studies whether they + + align:start position:0% +know from these studies whether they + + + align:start position:0% +know from these studies whether they +really understand that communication is + + align:start position:0% +really understand that communication is + + + align:start position:0% +really understand that communication is +happening or whether they're just seeing + + align:start position:0% +happening or whether they're just seeing + + + align:start position:0% +happening or whether they're just seeing +detecting some important features of + + align:start position:0% +detecting some important features of + + + align:start position:0% +detecting some important features of +communicative interactions that might + + align:start position:0% +communicative interactions that might + + + align:start position:0% +communicative interactions that might +help them to glom onto communication so + + align:start position:0% +help them to glom onto communication so + + + align:start position:0% +help them to glom onto communication so +that they can eventually develop an + + align:start position:0% +that they can eventually develop an + + + align:start position:0% +that they can eventually develop an +ability to figure out what's going on + + align:start position:0% +ability to figure out what's going on + + + align:start position:0% +ability to figure out what's going on +within the communicative interaction of + + align:start position:0% +within the communicative interaction of + + + align:start position:0% +within the communicative interaction of +themselves so so far in the studies I've + + align:start position:0% +themselves so so far in the studies I've + + + align:start position:0% +themselves so so far in the studies I've +mentioned there's nothing cognitive here + + align:start position:0% +mentioned there's nothing cognitive here + + + align:start position:0% +mentioned there's nothing cognitive here +there's nothing really about infants + + align:start position:0% +there's nothing really about infants + + + align:start position:0% +there's nothing really about infants +having to understand the attentions or + + align:start position:0% +having to understand the attentions or + + + align:start position:0% +having to understand the attentions or +the mental states of the speaker going + + align:start position:0% +the mental states of the speaker going + + + align:start position:0% +the mental states of the speaker going +into the mind of the addressee like I + + align:start position:0% +into the mind of the addressee like I + + + align:start position:0% +into the mind of the addressee like I +was talking about before + + align:start position:0% +was talking about before + + + align:start position:0% +was talking about before +so the question I've explored in my + + align:start position:0% +so the question I've explored in my + + + align:start position:0% +so the question I've explored in my +research is whether infants recognize + + align:start position:0% +research is whether infants recognize + + + align:start position:0% +research is whether infants recognize +that when these features are in place + + align:start position:0% +that when these features are in place + + + align:start position:0% +that when these features are in place +when you have a communicative signal + + align:start position:0% +when you have a communicative signal + + + align:start position:0% +when you have a communicative signal +which is something they recognize when + + align:start position:0% +which is something they recognize when + + + align:start position:0% +which is something they recognize when +you have a communicator an addressee who + + align:start position:0% +you have a communicator an addressee who + + + align:start position:0% +you have a communicator an addressee who +are socially engaged with each other to + + align:start position:0% +are socially engaged with each other to + + + align:start position:0% +are socially engaged with each other to +infants recognize that communication can + + align:start position:0% +infants recognize that communication can + + + align:start position:0% +infants recognize that communication can +actually lead to the transfer of + + align:start position:0% +actually lead to the transfer of + + + align:start position:0% +actually lead to the transfer of +information so two infants understand + + align:start position:0% +information so two infants understand + + + align:start position:0% +information so two infants understand +that that speech using speech because + + align:start position:0% +that that speech using speech because + + + align:start position:0% +that that speech using speech because +this is something that infants seem to + + align:start position:0% +this is something that infants seem to + + + align:start position:0% +this is something that infants seem to +recognize as a signal that's important + + align:start position:0% +recognize as a signal that's important + + + align:start position:0% +recognize as a signal that's important +in communicative contexts can transfer + + align:start position:0% +in communicative contexts can transfer + + + align:start position:0% +in communicative contexts can transfer +information between individuals so we + + align:start position:0% +information between individuals so we + + + align:start position:0% +information between individuals so we +can use speech to communicate with each + + align:start position:0% +can use speech to communicate with each + + + align:start position:0% +can use speech to communicate with each +other about what we're interested in so + + align:start position:0% +other about what we're interested in so + + + align:start position:0% +other about what we're interested in so +if I'm observing this interaction + + align:start position:0% +if I'm observing this interaction + + + align:start position:0% +if I'm observing this interaction +between a communicator and addressee I + + align:start position:0% +between a communicator and addressee I + + + align:start position:0% +between a communicator and addressee I +can infer that the if the communicator + + align:start position:0% +can infer that the if the communicator + + + align:start position:0% +can infer that the if the communicator +says the cup and there's only one cup + + align:start position:0% +says the cup and there's only one cup + + + align:start position:0% +says the cup and there's only one cup +present the addressee is probably going + + align:start position:0% +present the addressee is probably going + + + align:start position:0% +present the addressee is probably going +to be able to figure out what it is that + + align:start position:0% +to be able to figure out what it is that + + + align:start position:0% +to be able to figure out what it is that +the communicator wants and I can figure + + align:start position:0% +the communicator wants and I can figure + + + align:start position:0% +the communicator wants and I can figure +this out even from a third party + + align:start position:0% +this out even from a third party + + + align:start position:0% +this out even from a third party +perspective and I can also understand + + align:start position:0% +perspective and I can also understand + + + align:start position:0% +perspective and I can also understand +that other kinds of sounds like perhaps + + align:start position:0% +that other kinds of sounds like perhaps + + + align:start position:0% +that other kinds of sounds like perhaps +a positive emotional vocalization are + + align:start position:0% +a positive emotional vocalization are + + + align:start position:0% +a positive emotional vocalization are +not going to be as effective in + + align:start position:0% +not going to be as effective in + + + align:start position:0% +not going to be as effective in +communicating to the addressee what the + + align:start position:0% +communicating to the addressee what the + + + align:start position:0% +communicating to the addressee what the +communicator is interested in so speech + + align:start position:0% +communicator is interested in so speech + + + align:start position:0% +communicator is interested in so speech +and also other communicative signals as + + align:start position:0% +and also other communicative signals as + + + align:start position:0% +and also other communicative signals as +well that can specify this sort of + + align:start position:0% +well that can specify this sort of + + + align:start position:0% +well that can specify this sort of +information perhaps like pointing or + + align:start position:0% +information perhaps like pointing or + + + align:start position:0% +information perhaps like pointing or +particular kinds of gestures can + + align:start position:0% +particular kinds of gestures can + + + align:start position:0% +particular kinds of gestures can +transfer information from one individual + + align:start position:0% +transfer information from one individual + + + align:start position:0% +transfer information from one individual +to another + + align:start position:0% +to another + + + align:start position:0% +to another +so speech is going to be more effective + + align:start position:0% +so speech is going to be more effective + + + align:start position:0% +so speech is going to be more effective +for communicating than other kinds of + + align:start position:0% +for communicating than other kinds of + + + align:start position:0% +for communicating than other kinds of +non-communicative actions and + + align:start position:0% +non-communicative actions and + + + align:start position:0% +non-communicative actions and +importantly for the purposes of this + + align:start position:0% +importantly for the purposes of this + + + align:start position:0% +importantly for the purposes of this +study you're not just going to know that + + align:start position:0% +study you're not just going to know that + + + align:start position:0% +study you're not just going to know that +communicate communicative information + + align:start position:0% +communicate communicative information + + + align:start position:0% +communicate communicative information +transfer is going on because you know + + align:start position:0% +transfer is going on because you know + + + align:start position:0% +transfer is going on because you know +what the word cup means even in a + + align:start position:0% +what the word cup means even in a + + + align:start position:0% +what the word cup means even in a +situation where other kinds of words + + align:start position:0% +situation where other kinds of words + + + align:start position:0% +situation where other kinds of words +where you're listening to a foreign + + align:start position:0% +where you're listening to a foreign + + + align:start position:0% +where you're listening to a foreign +language and you have no idea what the + + align:start position:0% +language and you have no idea what the + + + align:start position:0% +language and you have no idea what the +meaning of + + align:start position:0% +meaning of + + + align:start position:0% +meaning of +are even in this situation you're going + + align:start position:0% +are even in this situation you're going + + + align:start position:0% +are even in this situation you're going +to understand that some kind of + + align:start position:0% +to understand that some kind of + + + align:start position:0% +to understand that some kind of +communicate information transfer can + + align:start position:0% +communicate information transfer can + + + align:start position:0% +communicate information transfer can +happen so we've all had the experience + + align:start position:0% +happen so we've all had the experience + + + align:start position:0% +happen so we've all had the experience +of being in a foreign country presumably + + align:start position:0% +of being in a foreign country presumably + + + align:start position:0% +of being in a foreign country presumably +where you're listening to people speak + + align:start position:0% +where you're listening to people speak + + + align:start position:0% +where you're listening to people speak +to each other you can't necessarily + + align:start position:0% +to each other you can't necessarily + + + align:start position:0% +to each other you can't necessarily +understand what they're saying but you + + align:start position:0% +understand what they're saying but you + + + align:start position:0% +understand what they're saying but you +know that information transfer is + + align:start position:0% +know that information transfer is + + + align:start position:0% +know that information transfer is +happening so the interesting thing about + + align:start position:0% +happening so the interesting thing about + + + align:start position:0% +happening so the interesting thing about +communicative actions like speech is + + align:start position:0% +communicative actions like speech is + + + align:start position:0% +communicative actions like speech is +that when we witness them we can know + + align:start position:0% +that when we witness them we can know + + + align:start position:0% +that when we witness them we can know +that people are communicatively sharing + + align:start position:0% +that people are communicatively sharing + + + align:start position:0% +that people are communicatively sharing +information even when we don't know what + + align:start position:0% +information even when we don't know what + + + align:start position:0% +information even when we don't know what +information is being communicated + + align:start position:0% +information is being communicated + + + align:start position:0% +information is being communicated +ourselves and this insight suggests that + + align:start position:0% +ourselves and this insight suggests that + + + align:start position:0% +ourselves and this insight suggests that +maybe if you're an infant one really + + align:start position:0% +maybe if you're an infant one really + + + align:start position:0% +maybe if you're an infant one really +good way to sort of jump into the + + align:start position:0% +good way to sort of jump into the + + + align:start position:0% +good way to sort of jump into the +communicative interactions around you + + align:start position:0% +communicative interactions around you + + + align:start position:0% +communicative interactions around you +and start to understand what's going on + + align:start position:0% +and start to understand what's going on + + + align:start position:0% +and start to understand what's going on +is to figure out when other it's to be + + align:start position:0% +is to figure out when other it's to be + + + align:start position:0% +is to figure out when other it's to be +able to identify when others are + + align:start position:0% +able to identify when others are + + + align:start position:0% +able to identify when others are +communicating and hearing the sounds of + + align:start position:0% +communicating and hearing the sounds of + + + align:start position:0% +communicating and hearing the sounds of +speech exchange between two people in + + align:start position:0% +speech exchange between two people in + + + align:start position:0% +speech exchange between two people in +the context of a social interaction + + align:start position:0% +the context of a social interaction + + + align:start position:0% +the context of a social interaction +might be a really good way to do this so + + align:start position:0% +might be a really good way to do this so + + + align:start position:0% +might be a really good way to do this so +an ability to figure out when + + align:start position:0% +an ability to figure out when + + + align:start position:0% +an ability to figure out when +communications going on like this might + + align:start position:0% +communications going on like this might + + + align:start position:0% +communications going on like this might +provide infants with this really + + align:start position:0% +provide infants with this really + + + align:start position:0% +provide infants with this really +powerful way of being able to track the + + align:start position:0% +powerful way of being able to track the + + + align:start position:0% +powerful way of being able to track the +information flow between two other + + align:start position:0% +information flow between two other + + + align:start position:0% +information flow between two other +people's minds and also to figure out + + align:start position:0% +people's minds and also to figure out + + + align:start position:0% +people's minds and also to figure out +based on their responses to each other + + align:start position:0% +based on their responses to each other + + + align:start position:0% +based on their responses to each other +what the actual content of the words + + align:start position:0% +what the actual content of the words + + + align:start position:0% +what the actual content of the words +might mean so we asked whether infants + + align:start position:0% +might mean so we asked whether infants + + + align:start position:0% +might mean so we asked whether infants +recognize that speech is communicative + + align:start position:0% +recognize that speech is communicative + + + align:start position:0% +recognize that speech is communicative +at 12 months of age and so in the + + align:start position:0% +at 12 months of age and so in the + + + align:start position:0% +at 12 months of age and so in the +procedure of the study infants were + + align:start position:0% +procedure of the study infants were + + + align:start position:0% +procedure of the study infants were +privy to add a third party interaction + + align:start position:0% +privy to add a third party interaction + + + align:start position:0% +privy to add a third party interaction +between a communicator and addressee and + + align:start position:0% +between a communicator and addressee and + + + align:start position:0% +between a communicator and addressee and +the infant is always just observing the + + align:start position:0% +the infant is always just observing the + + + align:start position:0% +the infant is always just observing the +interaction this is so that we can + + align:start position:0% +interaction this is so that we can + + + align:start position:0% +interaction this is so that we can +isolate whether infants think that + + align:start position:0% +isolate whether infants think that + + + align:start position:0% +isolate whether infants think that +communicate that certain communicative + + align:start position:0% +communicate that certain communicative + + + align:start position:0% +communicate that certain communicative +vocalizations can transfer information + + align:start position:0% +vocalizations can transfer information + + + align:start position:0% +vocalizations can transfer information +from the communicator to an addressee + + align:start position:0% +from the communicator to an addressee + + + align:start position:0% +from the communicator to an addressee +even when the infant themselves has all + + align:start position:0% +even when the infant themselves has all + + + align:start position:0% +even when the infant themselves has all +the information so the third party + + align:start position:0% +the information so the third party + + + align:start position:0% +the information so the third party +nature this procedure is important here + + align:start position:0% +nature this procedure is important here + + + align:start position:0% +nature this procedure is important here +for seeing whether infants really are + + align:start position:0% +for seeing whether infants really are + + + align:start position:0% +for seeing whether infants really are +thinking about the fact that thoughts + + align:start position:0% +thinking about the fact that thoughts + + + align:start position:0% +thinking about the fact that thoughts +are typically isolated in particular + + align:start position:0% +are typically isolated in particular + + + align:start position:0% +are typically isolated in particular +people's minds but the with + + align:start position:0% +people's minds but the with + + + align:start position:0% +people's minds but the with +communication they can be shared so in + + align:start position:0% +communication they can be shared so in + + + align:start position:0% +communication they can be shared so in +truth in these studies were given a + + align:start position:0% +truth in these studies were given a + + + align:start position:0% +truth in these studies were given a +violation of expectation paradigm so in + + align:start position:0% +violation of expectation paradigm so in + + + align:start position:0% +violation of expectation paradigm so in +this kind of experiment as many of you + + align:start position:0% +this kind of experiment as many of you + + + align:start position:0% +this kind of experiment as many of you +probably know infants are sort of shown + + align:start position:0% +probably know infants are sort of shown + + + align:start position:0% +probably know infants are sort of shown +a story through a series of scenes and + + align:start position:0% +a story through a series of scenes and + + + align:start position:0% +a story through a series of scenes and +then in the last scene or series of + + align:start position:0% +then in the last scene or series of + + + align:start position:0% +then in the last scene or series of +scenes they're shown different kinds of + + align:start position:0% +scenes they're shown different kinds of + + + align:start position:0% +scenes they're shown different kinds of +endings and we're interested in whether + + align:start position:0% +endings and we're interested in whether + + + align:start position:0% +endings and we're interested in whether +infants are surprised or look longer at + + align:start position:0% +infants are surprised or look longer at + + + align:start position:0% +infants are surprised or look longer at +some + + align:start position:0% +some + + + align:start position:0% +some +and names more than they do with others + + align:start position:0% +and names more than they do with others + + + align:start position:0% +and names more than they do with others +so infants in these studies were shown a + + align:start position:0% +so infants in these studies were shown a + + + align:start position:0% +so infants in these studies were shown a +live display where they had an actor in + + align:start position:0% +live display where they had an actor in + + + align:start position:0% +live display where they had an actor in +front of them in a stage first they were + + align:start position:0% +front of them in a stage first they were + + + align:start position:0% +front of them in a stage first they were +familiarized with this actor showing a + + align:start position:0% +familiarized with this actor showing a + + + align:start position:0% +familiarized with this actor showing a +preference for an object by picking it + + align:start position:0% +preference for an object by picking it + + + align:start position:0% +preference for an object by picking it +up and playing with it repeatedly in + + align:start position:0% +up and playing with it repeatedly in + + + align:start position:0% +up and playing with it repeatedly in +three separate scenes and so as in the + + align:start position:0% +three separate scenes and so as in the + + + align:start position:0% +three separate scenes and so as in the +studies by Amanda Woodward that Liz + + align:start position:0% +studies by Amanda Woodward that Liz + + + align:start position:0% +studies by Amanda Woodward that Liz +already mentioned infants tend to + + align:start position:0% +already mentioned infants tend to + + + align:start position:0% +already mentioned infants tend to +infants by 12 months and as early as + + align:start position:0% +infants by 12 months and as early as + + + align:start position:0% +infants by 12 months and as early as +three months will attribute a goal to + + align:start position:0% +three months will attribute a goal to + + + align:start position:0% +three months will attribute a goal to +this person for reaching for that + + align:start position:0% +this person for reaching for that + + + align:start position:0% +this person for reaching for that +particular target object so after being + + align:start position:0% +particular target object so after being + + + align:start position:0% +particular target object so after being +familiarized to this infant saw an + + align:start position:0% +familiarized to this infant saw an + + + align:start position:0% +familiarized to this infant saw an +address see who is a new person present + + align:start position:0% +address see who is a new person present + + + align:start position:0% +address see who is a new person present +in a totally different part of the stage + + align:start position:0% +in a totally different part of the stage + + + align:start position:0% +in a totally different part of the stage +they had never seen this person before + + align:start position:0% +they had never seen this person before + + + align:start position:0% +they had never seen this person before +and they'd never seen the two people + + align:start position:0% +and they'd never seen the two people + + + align:start position:0% +and they'd never seen the two people +together before this person reached for + + align:start position:0% +together before this person reached for + + + align:start position:0% +together before this person reached for +both objects in turn so first she + + align:start position:0% +both objects in turn so first she + + + align:start position:0% +both objects in turn so first she +grabbed this one then this one and then + + align:start position:0% +grabbed this one then this one and then + + + align:start position:0% +grabbed this one then this one and then +this one and then this one again to show + + align:start position:0% +this one and then this one again to show + + + align:start position:0% +this one and then this one again to show +that she didn't have a preference + + align:start position:0% +that she didn't have a preference + + + align:start position:0% +that she didn't have a preference +between the objects and could reach both + + align:start position:0% +between the objects and could reach both + + + align:start position:0% +between the objects and could reach both +of them then in the test scene so this + + align:start position:0% +of them then in the test scene so this + + + align:start position:0% +of them then in the test scene so this +is the ending that we showed infants + + align:start position:0% +is the ending that we showed infants + + + align:start position:0% +is the ending that we showed infants +they saw the two people together for the + + align:start position:0% +they saw the two people together for the + + + align:start position:0% +they saw the two people together for the +first time but now the communicator + + align:start position:0% +first time but now the communicator + + + align:start position:0% +first time but now the communicator +couldn't reach the objects because only + + align:start position:0% +couldn't reach the objects because only + + + align:start position:0% +couldn't reach the objects because only +her face would had access to the stage + + align:start position:0% +her face would had access to the stage + + + align:start position:0% +her face would had access to the stage +but the addressee could still reach them + + align:start position:0% +but the addressee could still reach them + + + align:start position:0% +but the addressee could still reach them +just fine at this point the the crucial + + align:start position:0% +just fine at this point the the crucial + + + align:start position:0% +just fine at this point the the crucial +manipulation was the vocalization + + align:start position:0% +manipulation was the vocalization + + + align:start position:0% +manipulation was the vocalization +uttered by the communicator so she + + align:start position:0% +uttered by the communicator so she + + + align:start position:0% +uttered by the communicator so she +either produced a speech sound the + + align:start position:0% +either produced a speech sound the + + + align:start position:0% +either produced a speech sound the +nonsense word koba which infants had not + + align:start position:0% +nonsense word koba which infants had not + + + align:start position:0% +nonsense word koba which infants had not +heard before she produced a coughing + + align:start position:0% +heard before she produced a coughing + + + align:start position:0% +heard before she produced a coughing +sound so something that would typically + + align:start position:0% +sound so something that would typically + + + align:start position:0% +sound so something that would typically +be physiological and not intentional or + + align:start position:0% +be physiological and not intentional or + + + align:start position:0% +be physiological and not intentional or +communicative in any way or an emotional + + align:start position:0% +communicative in any way or an emotional + + + align:start position:0% +communicative in any way or an emotional +vocalization so a sound that perhaps + + align:start position:0% +vocalization so a sound that perhaps + + + align:start position:0% +vocalization so a sound that perhaps +could convey information if I say ooh + + align:start position:0% +could convey information if I say ooh + + + align:start position:0% +could convey information if I say ooh +you might think I'm interested in + + align:start position:0% +you might think I'm interested in + + + align:start position:0% +you might think I'm interested in +something I'm feeling positive but you + + align:start position:0% +something I'm feeling positive but you + + + align:start position:0% +something I'm feeling positive but you +won't necessarily know what it is so + + align:start position:0% +won't necessarily know what it is so + + + align:start position:0% +won't necessarily know what it is so +this one's sort of in the middle of the + + align:start position:0% +this one's sort of in the middle of the + + + align:start position:0% +this one's sort of in the middle of the +other two and then infants saw the + + align:start position:0% +other two and then infants saw the + + + align:start position:0% +other two and then infants saw the +addressee either provide the target + + align:start position:0% +addressee either provide the target + + + align:start position:0% +addressee either provide the target +object that the communicator had reached + + align:start position:0% +object that the communicator had reached + + + align:start position:0% +object that the communicator had reached +for before or the non target object and + + align:start position:0% +for before or the non target object and + + + align:start position:0% +for before or the non target object and +the question is do infants understand + + align:start position:0% +the question is do infants understand + + + align:start position:0% +the question is do infants understand +that speech as a communicative signal do + + align:start position:0% +that speech as a communicative signal do + + + align:start position:0% +that speech as a communicative signal do +they have some expectation that even + + align:start position:0% +they have some expectation that even + + + align:start position:0% +they have some expectation that even +though they've never heard this + + align:start position:0% +though they've never heard this + + + align:start position:0% +though they've never heard this +particular speech sound used before that + + align:start position:0% +particular speech sound used before that + + + align:start position:0% +particular speech sound used before that +speech can transfer information such + + align:start position:0% +speech can transfer information such + + + align:start position:0% +speech can transfer information such +that the addressee will now be able to + + align:start position:0% +that the addressee will now be able to + + + align:start position:0% +that the addressee will now be able to +select the correct object whereas + + align:start position:0% +select the correct object whereas + + + align:start position:0% +select the correct object whereas +non-speech vocalizations like coughing + + align:start position:0% +non-speech vocalizations like coughing + + + align:start position:0% +non-speech vocalizations like coughing +and emotional vocalizations can't so if + + align:start position:0% +and emotional vocalizations can't so if + + + align:start position:0% +and emotional vocalizations can't so if +so infants in the speech condition + + align:start position:0% +so infants in the speech condition + + + align:start position:0% +so infants in the speech condition +should look longer tune on target than + + align:start position:0% +should look longer tune on target than + + + align:start position:0% +should look longer tune on target than +target actions finding these responses + + align:start position:0% +target actions finding these responses + + + align:start position:0% +target actions finding these responses +finding these unexpected and infants in + + align:start position:0% +finding these unexpected and infants in + + + align:start position:0% +finding these unexpected and infants in +the other two conditions + + align:start position:0% +the other two conditions + + + align:start position:0% +the other two conditions +differentiate between the two and this + + align:start position:0% +differentiate between the two and this + + + align:start position:0% +differentiate between the two and this +is what we found sofa then the speech + + align:start position:0% +is what we found sofa then the speech + + + align:start position:0% +is what we found sofa then the speech +condition infants are looking longer to + + align:start position:0% +condition infants are looking longer to + + + align:start position:0% +condition infants are looking longer to +non-target than targets suggesting that + + align:start position:0% +non-target than targets suggesting that + + + align:start position:0% +non-target than targets suggesting that +they understand that speech can transfer + + align:start position:0% +they understand that speech can transfer + + + align:start position:0% +they understand that speech can transfer +information about the communicators goal + + align:start position:0% +information about the communicators goal + + + align:start position:0% +information about the communicators goal +but when the communicator costs are + + align:start position:0% +but when the communicator costs are + + + align:start position:0% +but when the communicator costs are +produced as an emotional vocalization + + align:start position:0% +produced as an emotional vocalization + + + align:start position:0% +produced as an emotional vocalization +infants don't show these same + + align:start position:0% +infants don't show these same + + + align:start position:0% +infants don't show these same +expectations so this is some initial + + align:start position:0% +expectations so this is some initial + + + align:start position:0% +expectations so this is some initial +evidence that by 12 months infants not + + align:start position:0% +evidence that by 12 months infants not + + + align:start position:0% +evidence that by 12 months infants not +only recognize the context in which + + align:start position:0% +only recognize the context in which + + + align:start position:0% +only recognize the context in which +communication occurs and attend to + + align:start position:0% +communication occurs and attend to + + + align:start position:0% +communication occurs and attend to +speech is a special signal for + + align:start position:0% +speech is a special signal for + + + align:start position:0% +speech is a special signal for +communication but they also understand + + align:start position:0% +communication but they also understand + + + align:start position:0% +communication but they also understand +that that speech is something that's + + align:start position:0% +that that speech is something that's + + + align:start position:0% +that that speech is something that's +able to transfer information between two + + align:start position:0% +able to transfer information between two + + + align:start position:0% +able to transfer information between two +people so we also ran a few control + + align:start position:0% +people so we also ran a few control + + + align:start position:0% +people so we also ran a few control +conditions to rule out alternative + + align:start position:0% +conditions to rule out alternative + + + align:start position:0% +conditions to rule out alternative +explanations for this so one important + + align:start position:0% +explanations for this so one important + + + align:start position:0% +explanations for this so one important +question is our infants really reasoning + + align:start position:0% +question is our infants really reasoning + + + align:start position:0% +question is our infants really reasoning +about the the addresses access to + + align:start position:0% +about the the addresses access to + + + align:start position:0% +about the the addresses access to +information in this situation so for + + align:start position:0% +information in this situation so for + + + align:start position:0% +information in this situation so for +example in the case where the if infants + + align:start position:0% +example in the case where the if infants + + + align:start position:0% +example in the case where the if infants +are really reasoning with the addresses + + align:start position:0% +are really reasoning with the addresses + + + align:start position:0% +are really reasoning with the addresses +access to information then in a case + + align:start position:0% +access to information then in a case + + + align:start position:0% +access to information then in a case +where the communicator it makes a + + align:start position:0% +where the communicator it makes a + + + align:start position:0% +where the communicator it makes a +positive emotional vocalization and the + + align:start position:0% +positive emotional vocalization and the + + + align:start position:0% +positive emotional vocalization and the +addressee has previous information about + + align:start position:0% +addressee has previous information about + + + align:start position:0% +addressee has previous information about +what she's interested in so for example + + align:start position:0% +what she's interested in so for example + + + align:start position:0% +what she's interested in so for example +if she just saw that the communicator + + align:start position:0% +if she just saw that the communicator + + + align:start position:0% +if she just saw that the communicator +was trying to feed her child or wanted a + + align:start position:0% +was trying to feed her child or wanted a + + + align:start position:0% +was trying to feed her child or wanted a +drink of water she might know now that a + + align:start position:0% +drink of water she might know now that a + + + align:start position:0% +drink of water she might know now that a +positive emotional vocalization is + + align:start position:0% +positive emotional vocalization is + + + align:start position:0% +positive emotional vocalization is +indicating something like the cup so we + + align:start position:0% +indicating something like the cup so we + + + align:start position:0% +indicating something like the cup so we +set up a scenario like this as well in + + align:start position:0% +set up a scenario like this as well in + + + align:start position:0% +set up a scenario like this as well in +this case it's exactly the same as the + + align:start position:0% +this case it's exactly the same as the + + + align:start position:0% +this case it's exactly the same as the +previous study except that the addressee + + align:start position:0% +previous study except that the addressee + + + align:start position:0% +previous study except that the addressee +had visual access to the communicators + + align:start position:0% +had visual access to the communicators + + + align:start position:0% +had visual access to the communicators +preference during the familiarization + + align:start position:0% +preference during the familiarization + + + align:start position:0% +preference during the familiarization +phase so now she knows what it is that + + align:start position:0% +phase so now she knows what it is that + + + align:start position:0% +phase so now she knows what it is that +the communicator likes and this is + + align:start position:0% +the communicator likes and this is + + + align:start position:0% +the communicator likes and this is +important for making sure that infants + + align:start position:0% +important for making sure that infants + + + align:start position:0% +important for making sure that infants +recognize that something like visual + + align:start position:0% +recognize that something like visual + + + align:start position:0% +recognize that something like visual +access can provide the addressee with + + align:start position:0% +access can provide the addressee with + + + align:start position:0% +access can provide the addressee with +information about the communicators + + align:start position:0% +information about the communicators + + + align:start position:0% +information about the communicators +interest so now infants all the same + + align:start position:0% +interest so now infants all the same + + + align:start position:0% +interest so now infants all the same +address see familiarization and then in + + align:start position:0% +address see familiarization and then in + + + align:start position:0% +address see familiarization and then in +the test they saw the communicator + + align:start position:0% +the test they saw the communicator + + + align:start position:0% +the test they saw the communicator +produce the vocalization once again so + + align:start position:0% +produce the vocalization once again so + + + align:start position:0% +produce the vocalization once again so +now even though o is a not was not + + align:start position:0% +now even though o is a not was not + + + align:start position:0% +now even though o is a not was not +treated as a communicative vocalization + + align:start position:0% +treated as a communicative vocalization + + + align:start position:0% +treated as a communicative vocalization +in the previous studies if infants are + + align:start position:0% +in the previous studies if infants are + + + align:start position:0% +in the previous studies if infants are +reasoning about the kinds of information + + align:start position:0% +reasoning about the kinds of information + + + align:start position:0% +reasoning about the kinds of information +that the addressee has access to they + + align:start position:0% +that the addressee has access to they + + + align:start position:0% +that the addressee has access to they +should now expect that the addressee + + align:start position:0% +should now expect that the addressee + + + align:start position:0% +should now expect that the addressee +will provide the target object because + + align:start position:0% +will provide the target object because + + + align:start position:0% +will provide the target object because +she knows from a previous C and what the + + align:start position:0% +she knows from a previous C and what the + + + align:start position:0% +she knows from a previous C and what the +communicator was in + + align:start position:0% +communicator was in + + + align:start position:0% +communicator was in +student so this is important also for + + align:start position:0% +student so this is important also for + + + align:start position:0% +student so this is important also for +ruling out the possibility that maybe + + align:start position:0% +ruling out the possibility that maybe + + + align:start position:0% +ruling out the possibility that maybe +just hearing these non-communicative + + align:start position:0% +just hearing these non-communicative + + + align:start position:0% +just hearing these non-communicative +vocalizations surprises or confuses + + align:start position:0% +vocalizations surprises or confuses + + + align:start position:0% +vocalizations surprises or confuses +infants or makes them unable to reason + + align:start position:0% +infants or makes them unable to reason + + + align:start position:0% +infants or makes them unable to reason +about the scenario anymore here they're + + align:start position:0% +about the scenario anymore here they're + + + align:start position:0% +about the scenario anymore here they're +getting a non communicative vocalization + + align:start position:0% +getting a non communicative vocalization + + + align:start position:0% +getting a non communicative vocalization +but the addressee has access to + + align:start position:0% +but the addressee has access to + + + align:start position:0% +but the addressee has access to +information and here as in the speech + + align:start position:0% +information and here as in the speech + + + align:start position:0% +information and here as in the speech +condition infants look longer at the non + + align:start position:0% +condition infants look longer at the non + + + align:start position:0% +condition infants look longer at the non +target outcome so this is just sort of a + + align:start position:0% +target outcome so this is just sort of a + + + align:start position:0% +target outcome so this is just sort of a +some evidence that infants are really + + align:start position:0% +some evidence that infants are really + + + align:start position:0% +some evidence that infants are really +thinking about the idea that relevant + + align:start position:0% +thinking about the idea that relevant + + + align:start position:0% +thinking about the idea that relevant +sources of information such as a + + align:start position:0% +sources of information such as a + + + align:start position:0% +sources of information such as a +communicative vocalization but also + + align:start position:0% +communicative vocalization but also + + + align:start position:0% +communicative vocalization but also +prior visual access can give the address + + align:start position:0% +prior visual access can give the address + + + align:start position:0% +prior visual access can give the address +the information about the communicators + + align:start position:0% +the information about the communicators + + + align:start position:0% +the information about the communicators +goal so they are reasoning about + + align:start position:0% +goal so they are reasoning about + + + align:start position:0% +goal so they are reasoning about +information access another important + + align:start position:0% +information access another important + + + align:start position:0% +information access another important +question is are they really thinking + + align:start position:0% +question is are they really thinking + + + align:start position:0% +question is are they really thinking +about the source of information or do + + align:start position:0% +about the source of information or do + + + align:start position:0% +about the source of information or do +they have so what's what's really the + + align:start position:0% +they have so what's what's really the + + + align:start position:0% +they have so what's what's really the +mechanism behind what infants are doing + + align:start position:0% +mechanism behind what infants are doing + + + align:start position:0% +mechanism behind what infants are doing +here are they thinking something like + + align:start position:0% +here are they thinking something like + + + align:start position:0% +here are they thinking something like +when I hear speech everything will go + + align:start position:0% +when I hear speech everything will go + + + align:start position:0% +when I hear speech everything will go +well or the speaker is gonna get what + + align:start position:0% +well or the speaker is gonna get what + + + align:start position:0% +well or the speaker is gonna get what +she wants are they really thinking about + + align:start position:0% +she wants are they really thinking about + + + align:start position:0% +she wants are they really thinking about +communication in this causal way where + + align:start position:0% +communication in this causal way where + + + align:start position:0% +communication in this causal way where +the information has to come from the + + align:start position:0% +the information has to come from the + + + align:start position:0% +the information has to come from the +speaker and be delivered to the listener + + align:start position:0% +speaker and be delivered to the listener + + + align:start position:0% +speaker and be delivered to the listener +in order for it to work so to test for + + align:start position:0% +in order for it to work so to test for + + + align:start position:0% +in order for it to work so to test for +this infants another communicator + + align:start position:0% +this infants another communicator + + + align:start position:0% +this infants another communicator +familiarisation here the communicators + + align:start position:0% +familiarisation here the communicators + + + align:start position:0% +familiarisation here the communicators +alone so they've never seen the two + + align:start position:0% +alone so they've never seen the two + + + align:start position:0% +alone so they've never seen the two +people together before she reaches for + + align:start position:0% +people together before she reaches for + + + align:start position:0% +people together before she reaches for +the target object then they see the + + align:start position:0% +the target object then they see the + + + align:start position:0% +the target object then they see the +addressee again and then in the test + + align:start position:0% +addressee again and then in the test + + + align:start position:0% +addressee again and then in the test +scene in this case the addressee is the + + align:start position:0% +scene in this case the addressee is the + + + align:start position:0% +scene in this case the addressee is the +one who produces a speech so speech is + + align:start position:0% +one who produces a speech so speech is + + + align:start position:0% +one who produces a speech so speech is +present in the scene as it was before + + align:start position:0% +present in the scene as it was before + + + align:start position:0% +present in the scene as it was before +but it's not being produced by the + + align:start position:0% +but it's not being produced by the + + + align:start position:0% +but it's not being produced by the +communicator or the person who showed a + + align:start position:0% +communicator or the person who showed a + + + align:start position:0% +communicator or the person who showed a +preference + + align:start position:0% +preference + + + align:start position:0% +preference +so if infants just think that speech + + align:start position:0% +so if infants just think that speech + + + align:start position:0% +so if infants just think that speech +leads to people obtaining their goals or + + align:start position:0% +leads to people obtaining their goals or + + + align:start position:0% +leads to people obtaining their goals or +magical outcomes happening then they + + align:start position:0% +magical outcomes happening then they + + + align:start position:0% +magical outcomes happening then they +should expect the addressee to provide + + align:start position:0% +should expect the addressee to provide + + + align:start position:0% +should expect the addressee to provide +the target here as well but if they + + align:start position:0% +the target here as well but if they + + + align:start position:0% +the target here as well but if they +understand that they don't know anything + + align:start position:0% +understand that they don't know anything + + + align:start position:0% +understand that they don't know anything +about the addressee in which case this + + align:start position:0% +about the addressee in which case this + + + align:start position:0% +about the addressee in which case this +is not really informative about either + + align:start position:0% +is not really informative about either + + + align:start position:0% +is not really informative about either +object then they should look equally to + + align:start position:0% +object then they should look equally to + + + align:start position:0% +object then they should look equally to +both outcomes and in fact this is what + + align:start position:0% +both outcomes and in fact this is what + + + align:start position:0% +both outcomes and in fact this is what +they do at 12 months so infants here + + align:start position:0% +they do at 12 months so infants here + + + align:start position:0% +they do at 12 months so infants here +don't expect information to be + + align:start position:0% +don't expect information to be + + + align:start position:0% +don't expect information to be +transferred from one person to another + + align:start position:0% +transferred from one person to another + + + align:start position:0% +transferred from one person to another +unless the first person who communicated + + align:start position:0% +unless the first person who communicated + + + align:start position:0% +unless the first person who communicated +is the one who actually had the + + align:start position:0% +is the one who actually had the + + + align:start position:0% +is the one who actually had the +information to provide + + align:start position:0% + + + + align:start position:0% + +so in by 12 months infants seem to + + align:start position:0% +so in by 12 months infants seem to + + + align:start position:0% +so in by 12 months infants seem to +recognize that speech is communicative + + align:start position:0% +recognize that speech is communicative + + + align:start position:0% +recognize that speech is communicative +and they seem to have some of the parts + + align:start position:0% +and they seem to have some of the parts + + + align:start position:0% +and they seem to have some of the parts +of a causal model of communication + + align:start position:0% +of a causal model of communication + + + align:start position:0% +of a causal model of communication +they're not just thinking about speech + + align:start position:0% +they're not just thinking about speech + + + align:start position:0% +they're not just thinking about speech +as something that can produce successful + + align:start position:0% +as something that can produce successful + + + align:start position:0% +as something that can produce successful +outcomes but as something that can be + + align:start position:0% +outcomes but as something that can be + + + align:start position:0% +outcomes but as something that can be +used to have information move from the + + align:start position:0% +used to have information move from the + + + align:start position:0% +used to have information move from the +mind of one individual to another so a + + align:start position:0% +mind of one individual to another so a + + + align:start position:0% +mind of one individual to another so a +12 month olds seem to recognize that + + align:start position:0% +12 month olds seem to recognize that + + + align:start position:0% +12 month olds seem to recognize that +speech is communicative but we really + + align:start position:0% +speech is communicative but we really + + + align:start position:0% +speech is communicative but we really +wanted to get it the idea that + + align:start position:0% +wanted to get it the idea that + + + align:start position:0% +wanted to get it the idea that +understanding that speech is + + align:start position:0% +understanding that speech is + + + align:start position:0% +understanding that speech is +communicative might be something that + + align:start position:0% +communicative might be something that + + + align:start position:0% +communicative might be something that +drives and guides were learning and + + align:start position:0% +drives and guides were learning and + + + align:start position:0% +drives and guides were learning and +language acquisition rather than + + align:start position:0% +language acquisition rather than + + + align:start position:0% +language acquisition rather than +something that is as a result so what a + + align:start position:0% +something that is as a result so what a + + + align:start position:0% +something that is as a result so what a +12 month old could be doing in this + + align:start position:0% +12 month old could be doing in this + + + align:start position:0% +12 month old could be doing in this +study is hearing the word Koba + + align:start position:0% +study is hearing the word Koba + + + align:start position:0% +study is hearing the word Koba +associating it with the object that the + + align:start position:0% +associating it with the object that the + + + align:start position:0% +associating it with the object that the +communicator had reached for and then + + align:start position:0% +communicator had reached for and then + + + align:start position:0% +communicator had reached for and then +thinking okay that one's the Koba so + + align:start position:0% +thinking okay that one's the Koba so + + + align:start position:0% +thinking okay that one's the Koba so +that's what the address he should reach + + align:start position:0% +that's what the address he should reach + + + align:start position:0% +that's what the address he should reach +for but in these studies we were + + align:start position:0% +for but in these studies we were + + + align:start position:0% +for but in these studies we were +interested in whether infants at an even + + align:start position:0% +interested in whether infants at an even + + + align:start position:0% +interested in whether infants at an even +younger age who would very very very + + align:start position:0% +younger age who would very very very + + + align:start position:0% +younger age who would very very very +unlikely to be associating the word with + + align:start position:0% +unlikely to be associating the word with + + + align:start position:0% +unlikely to be associating the word with +the object are learning a label for the + + align:start position:0% +the object are learning a label for the + + + align:start position:0% +the object are learning a label for the +object over the course of the study + + align:start position:0% +object over the course of the study + + + align:start position:0% +object over the course of the study +would also recognize that speech can + + align:start position:0% +would also recognize that speech can + + + align:start position:0% +would also recognize that speech can +transfer information about one person to + + align:start position:0% +transfer information about one person to + + + align:start position:0% +transfer information about one person to +another person and so for this reason we + + align:start position:0% +another person and so for this reason we + + + align:start position:0% +another person and so for this reason we +tested six month olds because six month + + align:start position:0% +tested six month olds because six month + + + align:start position:0% +tested six month olds because six month +olds understand only some very very + + align:start position:0% +olds understand only some very very + + + align:start position:0% +olds understand only some very very +common words in their environment and + + align:start position:0% +common words in their environment and + + + align:start position:0% +common words in their environment and +will look to the right object when they + + align:start position:0% +will look to the right object when they + + + align:start position:0% +will look to the right object when they +hear the label for it but there's these + + align:start position:0% +hear the label for it but there's these + + + align:start position:0% +hear the label for it but there's these +are very very limited words and there's + + align:start position:0% +are very very limited words and there's + + + align:start position:0% +are very very limited words and there's +no evidence for learning a word in a + + align:start position:0% +no evidence for learning a word in a + + + align:start position:0% +no evidence for learning a word in a +single trial which is what they would + + align:start position:0% +single trial which is what they would + + + align:start position:0% +single trial which is what they would +have to do in this study they would have + + align:start position:0% +have to do in this study they would have + + + align:start position:0% +have to do in this study they would have +to hear Koba and then think back to what + + align:start position:0% +to hear Koba and then think back to what + + + align:start position:0% +to hear Koba and then think back to what +the ad communicator had reached for and + + align:start position:0% +the ad communicator had reached for and + + + align:start position:0% +the ad communicator had reached for and +really learn learn that word over the + + align:start position:0% +really learn learn that word over the + + + align:start position:0% +really learn learn that word over the +course of study which we have no + + align:start position:0% +course of study which we have no + + + align:start position:0% +course of study which we have no +evidence that a six-month-old can do so + + align:start position:0% +evidence that a six-month-old can do so + + + align:start position:0% +evidence that a six-month-old can do so +the goal of looking at this age group + + align:start position:0% +the goal of looking at this age group + + + align:start position:0% +the goal of looking at this age group +was to see whether infants might have a + + align:start position:0% +was to see whether infants might have a + + + align:start position:0% +was to see whether infants might have a +more abstract understanding of the idea + + align:start position:0% +more abstract understanding of the idea + + + align:start position:0% +more abstract understanding of the idea +that when speech is produced information + + align:start position:0% +that when speech is produced information + + + align:start position:0% +that when speech is produced information +can be transferred from one person to + + align:start position:0% +can be transferred from one person to + + + align:start position:0% +can be transferred from one person to +another even when they can when they + + align:start position:0% +another even when they can when they + + + align:start position:0% +another even when they can when they +themselves don't know what that + + align:start position:0% +themselves don't know what that + + + align:start position:0% +themselves don't know what that +information or what the the link between + + align:start position:0% +information or what the the link between + + + align:start position:0% +information or what the the link between +the word and the object so six-month-old + + align:start position:0% +the word and the object so six-month-old + + + align:start position:0% +the word and the object so six-month-old +saw the same scenes we give them the + + align:start position:0% +saw the same scenes we give them the + + + align:start position:0% +saw the same scenes we give them the +speech versus cough contrast and they + + align:start position:0% +speech versus cough contrast and they + + + align:start position:0% +speech versus cough contrast and they +look the same as the 12 month olds here + + align:start position:0% +look the same as the 12 month olds here + + + align:start position:0% +look the same as the 12 month olds here +so you can see that in the speech case + + align:start position:0% +so you can see that in the speech case + + + align:start position:0% +so you can see that in the speech case +they're looking longer for the + + align:start position:0% +they're looking longer for the + + + align:start position:0% +they're looking longer for the +non-target outcome in the COFF case + + align:start position:0% +non-target outcome in the COFF case + + + align:start position:0% +non-target outcome in the COFF case +they're looking longer for the target + + align:start position:0% +they're looking longer for the target + + + align:start position:0% +they're looking longer for the target +outcome and so we haven't done all the + + align:start position:0% +outcome and so we haven't done all the + + + align:start position:0% +outcome and so we haven't done all the +same control conditions as with the 12 + + align:start position:0% +same control conditions as with the 12 + + + align:start position:0% +same control conditions as with the 12 +month olds here so I think there's a lot + + align:start position:0% +month olds here so I think there's a lot + + + align:start position:0% +month olds here so I think there's a lot +of room for questions about how is six + + align:start position:0% +of room for questions about how is six + + + align:start position:0% +of room for questions about how is six +month olds understanding of + + align:start position:0% +month olds understanding of + + + align:start position:0% +month olds understanding of +munication in this causal way more + + align:start position:0% +munication in this causal way more + + + align:start position:0% +munication in this causal way more +limited than the understanding of 12 + + align:start position:0% +limited than the understanding of 12 + + + align:start position:0% +limited than the understanding of 12 +month olds would a six month old think + + align:start position:0% +month olds would a six month old think + + + align:start position:0% +month olds would a six month old think +that if speech was produced by a loud + + align:start position:0% +that if speech was produced by a loud + + + align:start position:0% +that if speech was produced by a loud +speaker or by the addressee that the + + align:start position:0% +speaker or by the addressee that the + + + align:start position:0% +speaker or by the addressee that the +communicator would still get the right + + align:start position:0% +communicator would still get the right + + + align:start position:0% +communicator would still get the right +object so there are a lot of open + + align:start position:0% +object so there are a lot of open + + + align:start position:0% +object so there are a lot of open +questions about the sort of basic these + + align:start position:0% +questions about the sort of basic these + + + align:start position:0% +questions about the sort of basic these +basic questions about how infants + + align:start position:0% +basic questions about how infants + + + align:start position:0% +basic questions about how infants +understanding of communicative + + align:start position:0% +understanding of communicative + + + align:start position:0% +understanding of communicative +information transfer starts out so these + + align:start position:0% +information transfer starts out so these + + + align:start position:0% +information transfer starts out so these +experiments suggest that by six months + + align:start position:0% +experiments suggest that by six months + + + align:start position:0% +experiments suggest that by six months +infants seem to understand that speech + + align:start position:0% +infants seem to understand that speech + + + align:start position:0% +infants seem to understand that speech +is communicative and they in addition to + + align:start position:0% +is communicative and they in addition to + + + align:start position:0% +is communicative and they in addition to +the other studies suggest they + + align:start position:0% +the other studies suggest they + + + align:start position:0% +the other studies suggest they +understand some of the features of + + align:start position:0% +understand some of the features of + + + align:start position:0% +understand some of the features of +communicative interactions and they + + align:start position:0% +communicative interactions and they + + + align:start position:0% +communicative interactions and they +recognize that it transfers information + + align:start position:0% +recognize that it transfers information + + + align:start position:0% +recognize that it transfers information +from one person to another and I'd like + + align:start position:0% +from one person to another and I'd like + + + align:start position:0% +from one person to another and I'd like +to argue that this might be something + + align:start position:0% +to argue that this might be something + + + align:start position:0% +to argue that this might be something +that provides a mechanism for language + + align:start position:0% +that provides a mechanism for language + + + align:start position:0% +that provides a mechanism for language +and knowledge acquisition so sort of + + align:start position:0% +and knowledge acquisition so sort of + + + align:start position:0% +and knowledge acquisition so sort of +guides infants to the kinds of relevant + + align:start position:0% +guides infants to the kinds of relevant + + + align:start position:0% +guides infants to the kinds of relevant +interactions where they might want to + + align:start position:0% +interactions where they might want to + + + align:start position:0% +interactions where they might want to +learn things about people and their + + align:start position:0% +learn things about people and their + + + align:start position:0% +learn things about people and their +mental states and the words that they're + + align:start position:0% +mental states and the words that they're + + + align:start position:0% +mental states and the words that they're +using rather than first learning those + + align:start position:0% +using rather than first learning those + + + align:start position:0% +using rather than first learning those +words through association and then later + + align:start position:0% +words through association and then later + + + align:start position:0% +words through association and then later +coming to this more abstract + + align:start position:0% +coming to this more abstract + + + align:start position:0% +coming to this more abstract +understanding so the idea of the + + align:start position:0% +understanding so the idea of the + + + align:start position:0% +understanding so the idea of the +infant's might start out with this + + align:start position:0% +infant's might start out with this + + + align:start position:0% +infant's might start out with this +understanding of what communication is + + align:start position:0% +understanding of what communication is + + + align:start position:0% +understanding of what communication is +and when it's happening and then can + + align:start position:0% +and when it's happening and then can + + + align:start position:0% +and when it's happening and then can +sort of fill in the rest from there and + + align:start position:0% +sort of fill in the rest from there and + + + align:start position:0% +sort of fill in the rest from there and +that this might be one of the earlier + + align:start position:0% +that this might be one of the earlier + + + align:start position:0% +that this might be one of the earlier +blocks of that so I'll try to go fairly + + align:start position:0% +blocks of that so I'll try to go fairly + + + align:start position:0% +blocks of that so I'll try to go fairly +quickly through the rest so the second + + align:start position:0% +quickly through the rest so the second + + + align:start position:0% +quickly through the rest so the second +insight I wanted to bring out that I + + align:start position:0% +insight I wanted to bring out that I + + + align:start position:0% +insight I wanted to bring out that I +think is especially important is that + + align:start position:0% +think is especially important is that + + + align:start position:0% +think is especially important is that +communication requires us focus on + + align:start position:0% +communication requires us focus on + + + align:start position:0% +communication requires us focus on +intentions and this was really the work + + align:start position:0% +intentions and this was really the work + + + align:start position:0% +intentions and this was really the work +of Grice that highlighted this and in + + align:start position:0% +of Grice that highlighted this and in + + + align:start position:0% +of Grice that highlighted this and in +particular a special type of + + align:start position:0% +particular a special type of + + + align:start position:0% +particular a special type of +communicative intention so going back to + + align:start position:0% +communicative intention so going back to + + + align:start position:0% +communicative intention so going back to +the example from the beginning when + + align:start position:0% +the example from the beginning when + + + align:start position:0% +the example from the beginning when +someone asks is there any salt austin + + align:start position:0% +someone asks is there any salt austin + + + align:start position:0% +someone asks is there any salt austin +proposed that there are these three + + align:start position:0% +proposed that there are these three + + + align:start position:0% +proposed that there are these three +levels on which we can think about this + + align:start position:0% +levels on which we can think about this + + + align:start position:0% +levels on which we can think about this +communicative action and grace was the + + align:start position:0% +communicative action and grace was the + + + align:start position:0% +communicative action and grace was the +one who really formalized this by + + align:start position:0% +one who really formalized this by + + + align:start position:0% +one who really formalized this by +talking about this special kind of + + align:start position:0% +talking about this special kind of + + + align:start position:0% +talking about this special kind of +intention that we see in the domain of + + align:start position:0% +intention that we see in the domain of + + + align:start position:0% +intention that we see in the domain of +communication human communication in + + align:start position:0% +communication human communication in + + + align:start position:0% +communication human communication in +particular which is the idea of speaker + + align:start position:0% +particular which is the idea of speaker + + + align:start position:0% +particular which is the idea of speaker +meaning and so his idea is that there + + align:start position:0% +meaning and so his idea is that there + + + align:start position:0% +meaning and so his idea is that there +are the there's this double layered + + align:start position:0% +are the there's this double layered + + + align:start position:0% +are the there's this double layered +intention that comes when we're + + align:start position:0% +intention that comes when we're + + + align:start position:0% +intention that comes when we're +communicating with each other so we have + + align:start position:0% +communicating with each other so we have + + + align:start position:0% +communicating with each other so we have +a communicator who intends the addressee + + align:start position:0% +a communicator who intends the addressee + + + align:start position:0% +a communicator who intends the addressee +to respond in a particular way so here + + align:start position:0% +to respond in a particular way so here + + + align:start position:0% +to respond in a particular way so here +the communicator wants the addressee to + + align:start position:0% +the communicator wants the addressee to + + + align:start position:0% +the communicator wants the addressee to +provide some salt the communicator + + align:start position:0% +provide some salt the communicator + + + align:start position:0% +provide some salt the communicator +intends for the addressee to recognize + + align:start position:0% +intends for the addressee to recognize + + + align:start position:0% +intends for the addressee to recognize +that the communicator intends to have + + align:start position:0% +that the communicator intends to have + + + align:start position:0% +that the communicator intends to have +that response so this person not only + + align:start position:0% +that response so this person not only + + + align:start position:0% +that response so this person not only +wants this person to pass the salt but + + align:start position:0% +wants this person to pass the salt but + + + align:start position:0% +wants this person to pass the salt but +wants her to pass the salt but wants her + + align:start position:0% +wants her to pass the salt but wants her + + + align:start position:0% +wants her to pass the salt but wants her +to recognize that + + align:start position:0% +to recognize that + + + align:start position:0% +to recognize that +what he's asking for that that is the + + align:start position:0% +what he's asking for that that is the + + + align:start position:0% +what he's asking for that that is the +request that he's making and importantly + + align:start position:0% +request that he's making and importantly + + + align:start position:0% +request that he's making and importantly +this third point which is that the + + align:start position:0% +this third point which is that the + + + align:start position:0% +this third point which is that the +communicator intends the addressee to + + align:start position:0% +communicator intends the addressee to + + + align:start position:0% +communicator intends the addressee to +fulfill the to respond that way on the + + align:start position:0% +fulfill the to respond that way on the + + + align:start position:0% +fulfill the to respond that way on the +basis of the recognition of that + + align:start position:0% +basis of the recognition of that + + + align:start position:0% +basis of the recognition of that +intention and so to make this a little + + align:start position:0% +intention and so to make this a little + + + align:start position:0% +intention and so to make this a little +more concrete in this case if he asks + + align:start position:0% +more concrete in this case if he asks + + + align:start position:0% +more concrete in this case if he asks +her for the salt and she passes it + + align:start position:0% +her for the salt and she passes it + + + align:start position:0% +her for the salt and she passes it +because she heard him and understands + + align:start position:0% +because she heard him and understands + + + align:start position:0% +because she heard him and understands +that that those he's asking for it + + align:start position:0% +that that those he's asking for it + + + align:start position:0% +that that those he's asking for it +that's great but the argument is that + + align:start position:0% +that's great but the argument is that + + + align:start position:0% +that's great but the argument is that +communication wouldn't really be + + align:start position:0% +communication wouldn't really be + + + align:start position:0% +communication wouldn't really be +happening if for example she was wearing + + align:start position:0% +happening if for example she was wearing + + + align:start position:0% +happening if for example she was wearing +headphones and listening to music and + + align:start position:0% +headphones and listening to music and + + + align:start position:0% +headphones and listening to music and +she hadn't really been listening to him + + align:start position:0% +she hadn't really been listening to him + + + align:start position:0% +she hadn't really been listening to him +and she just happened to pick up the + + align:start position:0% +and she just happened to pick up the + + + align:start position:0% +and she just happened to pick up the +salt and pass it to him so communication + + align:start position:0% +salt and pass it to him so communication + + + align:start position:0% +salt and pass it to him so communication +I mean it would looks like it would look + + align:start position:0% +I mean it would looks like it would look + + + align:start position:0% +I mean it would looks like it would look +like a communicative interaction the + + align:start position:0% +like a communicative interaction the + + + align:start position:0% +like a communicative interaction the +right kind of outcome is still happening + + align:start position:0% +right kind of outcome is still happening + + + align:start position:0% +right kind of outcome is still happening +in response to what he said but if she + + align:start position:0% +in response to what he said but if she + + + align:start position:0% +in response to what he said but if she +has no access to the actual message if + + align:start position:0% +has no access to the actual message if + + + align:start position:0% +has no access to the actual message if +she doesn't produce the response by + + align:start position:0% +she doesn't produce the response by + + + align:start position:0% +she doesn't produce the response by +virtue of understanding what the + + align:start position:0% +virtue of understanding what the + + + align:start position:0% +virtue of understanding what the +communicators trying to say then + + align:start position:0% +communicators trying to say then + + + align:start position:0% +communicators trying to say then +communication hasn't really occurred + + align:start position:0% +communication hasn't really occurred + + + align:start position:0% +communication hasn't really occurred +it's just sort of a lucky accident + + align:start position:0% + + + + align:start position:0% + +so I'll skip this part so the question + + align:start position:0% +so I'll skip this part so the question + + + align:start position:0% +so I'll skip this part so the question +is so this is this important kind of + + align:start position:0% +is so this is this important kind of + + + align:start position:0% +is so this is this important kind of +intention that we see in human + + align:start position:0% +intention that we see in human + + + align:start position:0% +intention that we see in human +communication in which I later briefly + + align:start position:0% +communication in which I later briefly + + + align:start position:0% +communication in which I later briefly +mentioned we don't really see an animal + + align:start position:0% +mentioned we don't really see an animal + + + align:start position:0% +mentioned we don't really see an animal +communication in the same sort of way so + + align:start position:0% +communication in the same sort of way so + + + align:start position:0% +communication in the same sort of way so +how do infants start to get this idea + + align:start position:0% +how do infants start to get this idea + + + align:start position:0% +how do infants start to get this idea +about communication that it's not just + + align:start position:0% +about communication that it's not just + + + align:start position:0% +about communication that it's not just +about identifying communicative + + align:start position:0% +about identifying communicative + + + align:start position:0% +about identifying communicative +interactions but also about + + align:start position:0% +interactions but also about + + + align:start position:0% +interactions but also about +understanding these particular kinds of + + align:start position:0% +understanding these particular kinds of + + + align:start position:0% +understanding these particular kinds of +intentions so in the 90s there was this + + align:start position:0% +intentions so in the 90s there was this + + + align:start position:0% +intentions so in the 90s there was this +shift in developmental psychology to + + align:start position:0% +shift in developmental psychology to + + + align:start position:0% +shift in developmental psychology to +looking at word learning not only in + + align:start position:0% +looking at word learning not only in + + + align:start position:0% +looking at word learning not only in +terms of of infants associations of + + align:start position:0% +terms of of infants associations of + + + align:start position:0% +terms of of infants associations of +words in the environment but also with + + align:start position:0% +words in the environment but also with + + + align:start position:0% +words in the environment but also with +the work of Dara Baldwin to thinking + + align:start position:0% +the work of Dara Baldwin to thinking + + + align:start position:0% +the work of Dara Baldwin to thinking +about other people's intentions when + + align:start position:0% +about other people's intentions when + + + align:start position:0% +about other people's intentions when +they're using words and so she had these + + align:start position:0% +they're using words and so she had these + + + align:start position:0% +they're using words and so she had these +really elegant studies where with kind + + align:start position:0% +really elegant studies where with kind + + + align:start position:0% +really elegant studies where with kind +of this funny image where she pointed + + align:start position:0% +of this funny image where she pointed + + + align:start position:0% +of this funny image where she pointed +out that if infants really were learning + + align:start position:0% +out that if infants really were learning + + + align:start position:0% +out that if infants really were learning +words through association then they + + align:start position:0% +words through association then they + + + align:start position:0% +words through association then they +would it wouldn't be very efficient for + + align:start position:0% +would it wouldn't be very efficient for + + + align:start position:0% +would it wouldn't be very efficient for +them because they would make a lot of + + align:start position:0% +them because they would make a lot of + + + align:start position:0% +them because they would make a lot of +mistakes so for example in this kind of + + align:start position:0% +mistakes so for example in this kind of + + + align:start position:0% +mistakes so for example in this kind of +situation here's a dad and his baby the + + align:start position:0% +situation here's a dad and his baby the + + + align:start position:0% +situation here's a dad and his baby the +baby is looking at this lizard the dad + + align:start position:0% +baby is looking at this lizard the dad + + + align:start position:0% +baby is looking at this lizard the dad +is looking at this rooster and the dad + + align:start position:0% +is looking at this rooster and the dad + + + align:start position:0% +is looking at this rooster and the dad +says what a cheeky rooster so if you as + + align:start position:0% +says what a cheeky rooster so if you as + + + align:start position:0% +says what a cheeky rooster so if you as +the infant are only learning words on + + align:start position:0% +the infant are only learning words on + + + align:start position:0% +the infant are only learning words on +the basis of associating what you hear + + align:start position:0% +the basis of associating what you hear + + + align:start position:0% +the basis of associating what you hear +with what you see you're going to learn + + align:start position:0% +with what you see you're going to learn + + + align:start position:0% +with what you see you're going to learn +that the word + + align:start position:0% +that the word + + + align:start position:0% +that the word +rooster refers to this thing rather than + + align:start position:0% +rooster refers to this thing rather than + + + align:start position:0% +rooster refers to this thing rather than +to this thing and you're gonna get it + + align:start position:0% +to this thing and you're gonna get it + + + align:start position:0% +to this thing and you're gonna get it +wrong so Baldwin did these whole host of + + align:start position:0% +wrong so Baldwin did these whole host of + + + align:start position:0% +wrong so Baldwin did these whole host of +studies in the second year of life where + + align:start position:0% +studies in the second year of life where + + + align:start position:0% +studies in the second year of life where +she had infants she set up situations + + align:start position:0% +she had infants she set up situations + + + align:start position:0% +she had infants she set up situations +where infants were looking at particular + + align:start position:0% +where infants were looking at particular + + + align:start position:0% +where infants were looking at particular +objects like here and then she had their + + align:start position:0% +objects like here and then she had their + + + align:start position:0% +objects like here and then she had their +parents or an experimenter look at a + + align:start position:0% +parents or an experimenter look at a + + + align:start position:0% +parents or an experimenter look at a +different object and labeled that one to + + align:start position:0% +different object and labeled that one to + + + align:start position:0% +different object and labeled that one to +see what infants would do and what she + + align:start position:0% +see what infants would do and what she + + + align:start position:0% +see what infants would do and what she +found is that infants actually would + + align:start position:0% +found is that infants actually would + + + align:start position:0% +found is that infants actually would +consult their parent or consult the + + align:start position:0% +consult their parent or consult the + + + align:start position:0% +consult their parent or consult the +other person for cues to reference to + + align:start position:0% +other person for cues to reference to + + + align:start position:0% +other person for cues to reference to +what they're intending to label so if + + align:start position:0% +what they're intending to label so if + + + align:start position:0% +what they're intending to label so if +for example in this situation the infant + + align:start position:0% +for example in this situation the infant + + + align:start position:0% +for example in this situation the infant +went hearing this instead of just + + align:start position:0% +went hearing this instead of just + + + align:start position:0% +went hearing this instead of just +assuming the word refers to what they're + + align:start position:0% +assuming the word refers to what they're + + + align:start position:0% +assuming the word refers to what they're +looking at would actually look up to dad + + align:start position:0% +looking at would actually look up to dad + + + align:start position:0% +looking at would actually look up to dad +to see what he's looking at and then + + align:start position:0% +to see what he's looking at and then + + + align:start position:0% +to see what he's looking at and then +follow his line of gaze to understand + + align:start position:0% +follow his line of gaze to understand + + + align:start position:0% +follow his line of gaze to understand +that this is the object that he's + + align:start position:0% +that this is the object that he's + + + align:start position:0% +that this is the object that he's +actually talking about so hmm yeah at + + align:start position:0% +actually talking about so hmm yeah at + + + align:start position:0% +actually talking about so hmm yeah at +this age yep so the idea is that infants + + align:start position:0% +this age yep so the idea is that infants + + + align:start position:0% +this age yep so the idea is that infants +in the second year of life at least our + + align:start position:0% +in the second year of life at least our + + + align:start position:0% +in the second year of life at least our +understanding that referent that + + align:start position:0% +understanding that referent that + + + align:start position:0% +understanding that referent that +understanding what someone's referring + + align:start position:0% +understanding what someone's referring + + + align:start position:0% +understanding what someone's referring +to involves consulting cues to their + + align:start position:0% +to involves consulting cues to their + + + align:start position:0% +to involves consulting cues to their +attention and intentions rather than + + align:start position:0% +attention and intentions rather than + + + align:start position:0% +attention and intentions rather than +just there at the infant zone and I + + align:start position:0% +just there at the infant zone and I + + + align:start position:0% +just there at the infant zone and I +think I'll skip this one there's just + + align:start position:0% +think I'll skip this one there's just + + + align:start position:0% +think I'll skip this one there's just +there other studies showing this to + + align:start position:0% +there other studies showing this to + + + align:start position:0% +there other studies showing this to +where so in this one there's an + + align:start position:0% +where so in this one there's an + + + align:start position:0% +where so in this one there's an +experimenter who puts these two objects + + align:start position:0% +experimenter who puts these two objects + + + align:start position:0% +experimenter who puts these two objects +in a box the objects which while she's + + align:start position:0% +in a box the objects which while she's + + + align:start position:0% +in a box the objects which while she's +absent and then she looks in one box and + + align:start position:0% +absent and then she looks in one box and + + + align:start position:0% +absent and then she looks in one box and +says she the boxes are closed and she + + align:start position:0% +says she the boxes are closed and she + + + align:start position:0% +says she the boxes are closed and she +says there's a CFO in here so if the + + align:start position:0% +says there's a CFO in here so if the + + + align:start position:0% +says there's a CFO in here so if the +infant understands that they have to pay + + align:start position:0% +infant understands that they have to pay + + + align:start position:0% +infant understands that they have to pay +attention to what the person knows about + + align:start position:0% +attention to what the person knows about + + + align:start position:0% +attention to what the person knows about +or the what the person thinks rather + + align:start position:0% +or the what the person thinks rather + + + align:start position:0% +or the what the person thinks rather +than their own knowledge to figure out + + align:start position:0% +than their own knowledge to figure out + + + align:start position:0% +than their own knowledge to figure out +what she's labeling but now when she + + align:start position:0% +what she's labeling but now when she + + + align:start position:0% +what she's labeling but now when she +says can you get the CFO the infant + + align:start position:0% +says can you get the CFO the infant + + + align:start position:0% +says can you get the CFO the infant +should actually pull the object out of + + align:start position:0% +should actually pull the object out of + + + align:start position:0% +should actually pull the object out of +here + + align:start position:0% +here + + + align:start position:0% +here +assuming that this is the one she's + + align:start position:0% +assuming that this is the one she's + + + align:start position:0% +assuming that this is the one she's +labeling because that's the one that she + + align:start position:0% +labeling because that's the one that she + + + align:start position:0% +labeling because that's the one that she +was attempting to intending label and in + + align:start position:0% +was attempting to intending label and in + + + align:start position:0% +was attempting to intending label and in +fact that's what infants do at 17 months + + align:start position:0% +fact that's what infants do at 17 months + + + align:start position:0% +fact that's what infants do at 17 months +in the case where the experiment had a + + align:start position:0% +in the case where the experiment had a + + + align:start position:0% +in the case where the experiment had a +false belief or about the location of + + align:start position:0% +false belief or about the location of + + + align:start position:0% +false belief or about the location of +the object infants tend to go to the non + + align:start position:0% +the object infants tend to go to the non + + + align:start position:0% +the object infants tend to go to the non +referred box more often because they + + align:start position:0% +referred box more often because they + + + align:start position:0% +referred box more often because they +think that that's the one that she's + + align:start position:0% +think that that's the one that she's + + + align:start position:0% +think that that's the one that she's +labeling but in the case where she saw + + align:start position:0% +labeling but in the case where she saw + + + align:start position:0% +labeling but in the case where she saw +this which happened so now she knows + + align:start position:0% +this which happened so now she knows + + + align:start position:0% +this which happened so now she knows +what every where infants will just go to + + align:start position:0% +what every where infants will just go to + + + align:start position:0% +what every where infants will just go to +the box that she's referring to to + + align:start position:0% +the box that she's referring to to + + + align:start position:0% +the box that she's referring to to +figure out the location of the object + + align:start position:0% +figure out the location of the object + + + align:start position:0% +figure out the location of the object +that she's naming + + align:start position:0% +that she's naming + + + align:start position:0% +that she's naming +so this is all in the second year of + + align:start position:0% +so this is all in the second year of + + + align:start position:0% +so this is all in the second year of +life not those younger sort of core + + align:start position:0% +life not those younger sort of core + + + align:start position:0% +life not those younger sort of core +knowledge ages that Liz was talking + + align:start position:0% +knowledge ages that Liz was talking + + + align:start position:0% +knowledge ages that Liz was talking +about but these so these are this is + + align:start position:0% +about but these so these are this is + + + align:start position:0% +about but these so these are this is +evidence that infants consult speaker + + align:start position:0% +evidence that infants consult speaker + + + align:start position:0% +evidence that infants consult speaker +cues to intentions but not of this + + align:start position:0% +cues to intentions but not of this + + + align:start position:0% +cues to intentions but not of this +special kind of intention that grace was + + align:start position:0% +special kind of intention that grace was + + + align:start position:0% +special kind of intention that grace was +pointing out so I'm just going to tell + + align:start position:0% +pointing out so I'm just going to tell + + + align:start position:0% +pointing out so I'm just going to tell +you about a couple of well one of my + + align:start position:0% +you about a couple of well one of my + + + align:start position:0% +you about a couple of well one of my +favorite studies I just think this is + + align:start position:0% +favorite studies I just think this is + + + align:start position:0% +favorite studies I just think this is +really neat where Ellen Martin's lab and + + align:start position:0% +really neat where Ellen Martin's lab and + + + align:start position:0% +really neat where Ellen Martin's lab and +then later replicated by Thomas Ellis + + align:start position:0% +then later replicated by Thomas Ellis + + + align:start position:0% +then later replicated by Thomas Ellis +lab showed that it seems like children + + align:start position:0% +lab showed that it seems like children + + + align:start position:0% +lab showed that it seems like children +by 30 months and then gotten down to 18 + + align:start position:0% +by 30 months and then gotten down to 18 + + + align:start position:0% +by 30 months and then gotten down to 18 +months by gross at all actually do seem + + align:start position:0% +months by gross at all actually do seem + + + align:start position:0% +months by gross at all actually do seem +to care about not only the effects of + + align:start position:0% +to care about not only the effects of + + + align:start position:0% +to care about not only the effects of +action the effects of communication but + + align:start position:0% +action the effects of communication but + + + align:start position:0% +action the effects of communication but +also that the the effects are produced + + align:start position:0% +also that the the effects are produced + + + align:start position:0% +also that the the effects are produced +by virtue of the message being + + align:start position:0% +by virtue of the message being + + + align:start position:0% +by virtue of the message being +understood so you're probably wondering + + align:start position:0% +understood so you're probably wondering + + + align:start position:0% +understood so you're probably wondering +why there's a dirty sock on the screen + + align:start position:0% +why there's a dirty sock on the screen + + + align:start position:0% +why there's a dirty sock on the screen +so in this study infants where children + + align:start position:0% +so in this study infants where children + + + align:start position:0% +so in this study infants where children +were presented with these with two + + align:start position:0% +were presented with these with two + + + align:start position:0% +were presented with these with two +objects so they saw on a table there + + align:start position:0% +objects so they saw on a table there + + + align:start position:0% +objects so they saw on a table there +were two objects that were out of their + + align:start position:0% +were two objects that were out of their + + + align:start position:0% +were two objects that were out of their +reach a truck and a and a dirty sock and + + align:start position:0% +reach a truck and a and a dirty sock and + + + align:start position:0% +reach a truck and a and a dirty sock and +the idea was to elicit children to + + align:start position:0% +the idea was to elicit children to + + + align:start position:0% +the idea was to elicit children to +request an object now obviously the + + align:start position:0% +request an object now obviously the + + + align:start position:0% +request an object now obviously the +children are going to request this + + align:start position:0% +children are going to request this + + + align:start position:0% +children are going to request this +object which is what the researchers had + + align:start position:0% +object which is what the researchers had + + + align:start position:0% +object which is what the researchers had +intended in this case + + align:start position:0% +intended in this case + + + align:start position:0% +intended in this case +so children tended to point at this + + align:start position:0% +so children tended to point at this + + + align:start position:0% +so children tended to point at this +object so they had children producing + + align:start position:0% +object so they had children producing + + + align:start position:0% +object so they had children producing +their own communication and then the + + align:start position:0% +their own communication and then the + + + align:start position:0% +their own communication and then the +experimenter responded to the + + align:start position:0% +experimenter responded to the + + + align:start position:0% +experimenter responded to the +communication of the infant in one of + + align:start position:0% +communication of the infant in one of + + + align:start position:0% +communication of the infant in one of +four different ways so she either said + + align:start position:0% +four different ways so she either said + + + align:start position:0% +four different ways so she either said +you asked for the truck I'm gonna give + + align:start position:0% +you asked for the truck I'm gonna give + + + align:start position:0% +you asked for the truck I'm gonna give +you the truck so she expressed + + align:start position:0% +you the truck so she expressed + + + align:start position:0% +you the truck so she expressed +understanding of the request and she + + align:start position:0% +understanding of the request and she + + + align:start position:0% +understanding of the request and she +provided the requested object in a + + align:start position:0% +provided the requested object in a + + + align:start position:0% +provided the requested object in a +second case she said you asked for the + + align:start position:0% +second case she said you asked for the + + + align:start position:0% +second case she said you asked for the +truck I'm gonna give you the sock so he + + align:start position:0% +truck I'm gonna give you the sock so he + + + align:start position:0% +truck I'm gonna give you the sock so he +or she expressed understanding but + + align:start position:0% +or she expressed understanding but + + + align:start position:0% +or she expressed understanding but +refused to commit to the request to give + + align:start position:0% +refused to commit to the request to give + + + align:start position:0% +refused to commit to the request to give +alert the same the thing the child had + + align:start position:0% +alert the same the thing the child had + + + align:start position:0% +alert the same the thing the child had +asked for in a third case the + + align:start position:0% +asked for in a third case the + + + align:start position:0% +asked for in a third case the +experimenter said you asked for the sock + + align:start position:0% +experimenter said you asked for the sock + + + align:start position:0% +experimenter said you asked for the sock +I'm going to give you the truck so this + + align:start position:0% +I'm going to give you the truck so this + + + align:start position:0% +I'm going to give you the truck so this +isn't it this is kind of a strange + + align:start position:0% +isn't it this is kind of a strange + + + align:start position:0% +isn't it this is kind of a strange +pragmatic situation where the + + align:start position:0% +pragmatic situation where the + + + align:start position:0% +pragmatic situation where the +experimenter actually gave the child the + + align:start position:0% +experimenter actually gave the child the + + + align:start position:0% +experimenter actually gave the child the +object they wanted but she expressed a + + align:start position:0% +object they wanted but she expressed a + + + align:start position:0% +object they wanted but she expressed a +misunderstanding of the child's request + + align:start position:0% +misunderstanding of the child's request + + + align:start position:0% +misunderstanding of the child's request +and this is the crucial case here so the + + align:start position:0% +and this is the crucial case here so the + + + align:start position:0% +and this is the crucial case here so the +question is obviously in the case where + + align:start position:0% +question is obviously in the case where + + + align:start position:0% +question is obviously in the case where +the experimenter provides the thing and + + align:start position:0% +the experimenter provides the thing and + + + align:start position:0% +the experimenter provides the thing and +expressed as understanding infants + + align:start position:0% +expressed as understanding infants + + + align:start position:0% +expressed as understanding infants +children should be quite happy and in + + align:start position:0% +children should be quite happy and in + + + align:start position:0% +children should be quite happy and in +this situation they probably shouldn't + + align:start position:0% +this situation they probably shouldn't + + + align:start position:0% +this situation they probably shouldn't +be very happy and what the experimenters + + align:start position:0% +be very happy and what the experimenters + + + align:start position:0% +be very happy and what the experimenters +measured was the amount of times that + + align:start position:0% +measured was the amount of times that + + + align:start position:0% +measured was the amount of times that +the child repeated the label of the + + align:start position:0% +the child repeated the label of the + + + align:start position:0% +the child repeated the label of the +object that they had asked for and they + + align:start position:0% +object that they had asked for and they + + + align:start position:0% +object that they had asked for and they +also measured other + + align:start position:0% +also measured other + + + align:start position:0% +also measured other +behaviors as well it's this situation + + align:start position:0% +behaviors as well it's this situation + + + align:start position:0% +behaviors as well it's this situation +that's important for understanding + + align:start position:0% +that's important for understanding + + + align:start position:0% +that's important for understanding +whether what what kids care about in the + + align:start position:0% +whether what what kids care about in the + + + align:start position:0% +whether what what kids care about in the +context of this communicative + + align:start position:0% +context of this communicative + + + align:start position:0% +context of this communicative +interaction so the question is do our + + align:start position:0% +interaction so the question is do our + + + align:start position:0% +interaction so the question is do our +infants perfectly happy here to take the + + align:start position:0% +infants perfectly happy here to take the + + + align:start position:0% +infants perfectly happy here to take the +truck and not complain because they got + + align:start position:0% +truck and not complain because they got + + + align:start position:0% +truck and not complain because they got +what they wanted or do they care about + + align:start position:0% +what they wanted or do they care about + + + align:start position:0% +what they wanted or do they care about +the experiment or giving them what they + + align:start position:0% +the experiment or giving them what they + + + align:start position:0% +the experiment or giving them what they +wanted because they're communicated + + align:start position:0% +wanted because they're communicated + + + align:start position:0% +wanted because they're communicated +message had the proper effect on the + + align:start position:0% +message had the proper effect on the + + + align:start position:0% +message had the proper effect on the +communicator on the on addressing and + + align:start position:0% +communicator on the on addressing and + + + align:start position:0% +communicator on the on addressing and +what they find is that when the correct + + align:start position:0% +what they find is that when the correct + + + align:start position:0% +what they find is that when the correct +object is provided and the experimenter + + align:start position:0% +object is provided and the experimenter + + + align:start position:0% +object is provided and the experimenter +does not express understanding of the + + align:start position:0% +does not express understanding of the + + + align:start position:0% +does not express understanding of the +request infants actually showed the most + + align:start position:0% +request infants actually showed the most + + + align:start position:0% +request infants actually showed the most +repetitions of the name of the requested + + align:start position:0% +repetitions of the name of the requested + + + align:start position:0% +repetitions of the name of the requested +object in this case and so it seems like + + align:start position:0% +object in this case and so it seems like + + + align:start position:0% +object in this case and so it seems like +they the researchers concluded from this + + align:start position:0% +they the researchers concluded from this + + + align:start position:0% +they the researchers concluded from this +the infants don't just care about + + align:start position:0% +the infants don't just care about + + + align:start position:0% +the infants don't just care about +getting what they want or using + + align:start position:0% +getting what they want or using + + + align:start position:0% +getting what they want or using +communication as a means of as a sort of + + align:start position:0% +communication as a means of as a sort of + + + align:start position:0% +communication as a means of as a sort of +instrumental means of getting people to + + align:start position:0% +instrumental means of getting people to + + + align:start position:0% +instrumental means of getting people to +act in certain ways but rather as an + + align:start position:0% +act in certain ways but rather as an + + + align:start position:0% +act in certain ways but rather as an +intention to have their messages + + align:start position:0% +intention to have their messages + + + align:start position:0% +intention to have their messages +understood and delivered to the other + + align:start position:0% +understood and delivered to the other + + + align:start position:0% +understood and delivered to the other +person so they care about the impact of + + align:start position:0% +person so they care about the impact of + + + align:start position:0% +person so they care about the impact of +their communicative signals on the + + align:start position:0% +their communicative signals on the + + + align:start position:0% +their communicative signals on the +understanding of the addressee not just + + align:start position:0% +understanding of the addressee not just + + + align:start position:0% +understanding of the addressee not just +on the response of the addressee which + + align:start position:0% +on the response of the addressee which + + + align:start position:0% +on the response of the addressee which +is sort of like the idea that grace was + + align:start position:0% +is sort of like the idea that grace was + + + align:start position:0% +is sort of like the idea that grace was +talking about with speaker meaning + + align:start position:0% +talking about with speaker meaning + + + align:start position:0% +talking about with speaker meaning +similarly when children are responding + + align:start position:0% +similarly when children are responding + + + align:start position:0% +similarly when children are responding +to other people's requests they also + + align:start position:0% +to other people's requests they also + + + align:start position:0% +to other people's requests they also +care about this so this is a study that + + align:start position:0% +care about this so this is a study that + + + align:start position:0% +care about this so this is a study that +I did in graduate school we had it's + + align:start position:0% +I did in graduate school we had it's + + + align:start position:0% +I did in graduate school we had it's +kind of sort of the opposite of the + + align:start position:0% +kind of sort of the opposite of the + + + align:start position:0% +kind of sort of the opposite of the +previous study or the inverse so we had + + align:start position:0% +previous study or the inverse so we had + + + align:start position:0% +previous study or the inverse so we had +an experiment or asking requesting the + + align:start position:0% +an experiment or asking requesting the + + + align:start position:0% +an experiment or asking requesting the +chat from the child specific object for + + align:start position:0% +chat from the child specific object for + + + align:start position:0% +chat from the child specific object for +doing specific tasks so she would ask + + align:start position:0% +doing specific tasks so she would ask + + + align:start position:0% +doing specific tasks so she would ask +for some this was three-year-olds so she + + align:start position:0% +for some this was three-year-olds so she + + + align:start position:0% +for some this was three-year-olds so she +would request something like a cup to + + align:start position:0% +would request something like a cup to + + + align:start position:0% +would request something like a cup to +pour a cup of water the child had + + align:start position:0% +pour a cup of water the child had + + + align:start position:0% +pour a cup of water the child had +previous information from playing games + + align:start position:0% +previous information from playing games + + + align:start position:0% +previous information from playing games +with the object with another experiment + + align:start position:0% +with the object with another experiment + + + align:start position:0% +with the object with another experiment +or that one of the cups was perfectly + + align:start position:0% +or that one of the cups was perfectly + + + align:start position:0% +or that one of the cups was perfectly +fine and one of the cups was broken and + + align:start position:0% +fine and one of the cups was broken and + + + align:start position:0% +fine and one of the cups was broken and +had a big hole in the bottom and so when + + align:start position:0% +had a big hole in the bottom and so when + + + align:start position:0% +had a big hole in the bottom and so when +the experimenter asked for a cup the + + align:start position:0% +the experimenter asked for a cup the + + + align:start position:0% +the experimenter asked for a cup the +child could either give the cup the + + align:start position:0% +child could either give the cup the + + + align:start position:0% +child could either give the cup the +experimenter asked for which was + + align:start position:0% +experimenter asked for which was + + + align:start position:0% +experimenter asked for which was +sometimes the perfectly good cup or they + + align:start position:0% +sometimes the perfectly good cup or they + + + align:start position:0% +sometimes the perfectly good cup or they +could give the or sometimes the + + align:start position:0% +could give the or sometimes the + + + align:start position:0% +could give the or sometimes the +experiment or requested the broken cup + + align:start position:0% +experiment or requested the broken cup + + + align:start position:0% +experiment or requested the broken cup +and the question was do children pay + + align:start position:0% +and the question was do children pay + + + align:start position:0% +and the question was do children pay +attention to the fit between the task + + align:start position:0% +attention to the fit between the task + + + align:start position:0% +attention to the fit between the task +and what the experimenter wanted when + + align:start position:0% +and what the experimenter wanted when + + + align:start position:0% +and what the experimenter wanted when +they're responding to her request and + + align:start position:0% +they're responding to her request and + + + align:start position:0% +they're responding to her request and +what we found is the infants is that + + align:start position:0% +what we found is the infants is that + + + align:start position:0% +what we found is the infants is that +children were much more likely to give + + align:start position:0% +children were much more likely to give + + + align:start position:0% +children were much more likely to give +the requested object when the experiment + + align:start position:0% +the requested object when the experiment + + + align:start position:0% +the requested object when the experiment +requested a functional object then when + + align:start position:0% +requested a functional object then when + + + align:start position:0% +requested a functional object then when +she'd requested a dysfunctional object + + align:start position:0% +she'd requested a dysfunctional object + + + align:start position:0% +she'd requested a dysfunctional object +so if I say I need to pour a cup of + + align:start position:0% +so if I say I need to pour a cup of + + + align:start position:0% +so if I say I need to pour a cup of +water can you give me that cup and the + + align:start position:0% +water can you give me that cup and the + + + align:start position:0% +water can you give me that cup and the +cup is broken + + align:start position:0% +cup is broken + + + align:start position:0% +cup is broken +children tended to go and get a better + + align:start position:0% +children tended to go and get a better + + + align:start position:0% +children tended to go and get a better +cup instead instead of the one that I + + align:start position:0% +cup instead instead of the one that I + + + align:start position:0% +cup instead instead of the one that I +had requested interestingly though even + + align:start position:0% +had requested interestingly though even + + + align:start position:0% +had requested interestingly though even +though children did this it didn't seem + + align:start position:0% +though children did this it didn't seem + + + align:start position:0% +though children did this it didn't seem +to be enough for them to give the + + align:start position:0% +to be enough for them to give the + + + align:start position:0% +to be enough for them to give the +experiment or something good that she + + align:start position:0% +experiment or something good that she + + + align:start position:0% +experiment or something good that she +wanted this is a graph of the comments + + align:start position:0% +wanted this is a graph of the comments + + + align:start position:0% +wanted this is a graph of the comments +that children made about the function of + + align:start position:0% +that children made about the function of + + + align:start position:0% +that children made about the function of +the object depending on the kind of + + align:start position:0% +the object depending on the kind of + + + align:start position:0% +the object depending on the kind of +request that was made and what you can + + align:start position:0% +request that was made and what you can + + + align:start position:0% +request that was made and what you can +see is that when a dysfunctional object + + align:start position:0% +see is that when a dysfunctional object + + + align:start position:0% +see is that when a dysfunctional object +was requested when children tended to + + align:start position:0% +was requested when children tended to + + + align:start position:0% +was requested when children tended to +provide the functional object instead + + align:start position:0% +provide the functional object instead + + + align:start position:0% +provide the functional object instead +and not respond to the requests they + + align:start position:0% +and not respond to the requests they + + + align:start position:0% +and not respond to the requests they +were much more likely to try to explain + + align:start position:0% +were much more likely to try to explain + + + align:start position:0% +were much more likely to try to explain +their behavior to the experimenter and + + align:start position:0% +their behavior to the experimenter and + + + align:start position:0% +their behavior to the experimenter and +acknowledge what it was the experimenter + + align:start position:0% +acknowledge what it was the experimenter + + + align:start position:0% +acknowledge what it was the experimenter +had originally wanted so it seems like + + align:start position:0% +had originally wanted so it seems like + + + align:start position:0% +had originally wanted so it seems like +children in their own behavior by at + + align:start position:0% +children in their own behavior by at + + + align:start position:0% +children in their own behavior by at +least three which is a little older than + + align:start position:0% +least three which is a little older than + + + align:start position:0% +least three which is a little older than +the other studies acknowledge what the + + align:start position:0% +the other studies acknowledge what the + + + align:start position:0% +the other studies acknowledge what the +speaker meant to ask for and explain + + align:start position:0% +speaker meant to ask for and explain + + + align:start position:0% +speaker meant to ask for and explain +while they're doing something else + + align:start position:0% +while they're doing something else + + + align:start position:0% +while they're doing something else +even when they're not responding to that + + align:start position:0% +even when they're not responding to that + + + align:start position:0% +even when they're not responding to that +thing and so just briefly in the last + + align:start position:0% +thing and so just briefly in the last + + + align:start position:0% +thing and so just briefly in the last +section on I'll talk about a third + + align:start position:0% +section on I'll talk about a third + + + align:start position:0% +section on I'll talk about a third +insight about communication that I think + + align:start position:0% +insight about communication that I think + + + align:start position:0% +insight about communication that I think +is really important which comes from + + align:start position:0% +is really important which comes from + + + align:start position:0% +is really important which comes from +Clarke which is that communication is + + align:start position:0% +Clarke which is that communication is + + + align:start position:0% +Clarke which is that communication is +this joint action of accumulating common + + align:start position:0% +this joint action of accumulating common + + + align:start position:0% +this joint action of accumulating common +ground and so in an example of an adult + + align:start position:0% +ground and so in an example of an adult + + + align:start position:0% +ground and so in an example of an adult +study about this + + align:start position:0% +study about this + + + align:start position:0% +study about this +they showed adults pictures like this + + align:start position:0% +they showed adults pictures like this + + + align:start position:0% +they showed adults pictures like this +one of New York City and they had people + + align:start position:0% +one of New York City and they had people + + + align:start position:0% +one of New York City and they had people +play this game in pairs they had people + + align:start position:0% +play this game in pairs they had people + + + align:start position:0% +play this game in pairs they had people +who knew about New York City who were + + align:start position:0% +who knew about New York City who were + + + align:start position:0% +who knew about New York City who were +experts and who lived there and then + + align:start position:0% +experts and who lived there and then + + + align:start position:0% +experts and who lived there and then +they had other people who didn't know + + align:start position:0% +they had other people who didn't know + + + align:start position:0% +they had other people who didn't know +anything about New York City and they + + align:start position:0% +anything about New York City and they + + + align:start position:0% +anything about New York City and they +gave them a bunch of pictures and they + + align:start position:0% +gave them a bunch of pictures and they + + + align:start position:0% +gave them a bunch of pictures and they +wanted to see they told them that their + + align:start position:0% +wanted to see they told them that their + + + align:start position:0% +wanted to see they told them that their +goal was to had that what the person who + + align:start position:0% +goal was to had that what the person who + + + align:start position:0% +goal was to had that what the person who +was the address he had to sort the + + align:start position:0% +was the address he had to sort the + + + align:start position:0% +was the address he had to sort the +objects in the way that the communicator + + align:start position:0% +objects in the way that the communicator + + + align:start position:0% +objects in the way that the communicator +told them to and so as a communicator + + align:start position:0% +told them to and so as a communicator + + + align:start position:0% +told them to and so as a communicator +the communicator had to indicate because + + align:start position:0% +the communicator had to indicate because + + + align:start position:0% +the communicator had to indicate because +they couldn't see the pictures which + + align:start position:0% +they couldn't see the pictures which + + + align:start position:0% +they couldn't see the pictures which +picture the address he should put where + + align:start position:0% +picture the address he should put where + + + align:start position:0% +picture the address he should put where +and to do this she had to refer that a + + align:start position:0% +and to do this she had to refer that a + + + align:start position:0% +and to do this she had to refer that a +communicator had to refer to things like + + align:start position:0% +communicator had to refer to things like + + + align:start position:0% +communicator had to refer to things like +the picture with the Empire State + + align:start position:0% +the picture with the Empire State + + + align:start position:0% +the picture with the Empire State +Building in it and what they looked at + + align:start position:0% +Building in it and what they looked at + + + align:start position:0% +Building in it and what they looked at +was how people in these interactions + + align:start position:0% +was how people in these interactions + + + align:start position:0% +was how people in these interactions +accumulated shared knowledge or common + + align:start position:0% +accumulated shared knowledge or common + + + align:start position:0% +accumulated shared knowledge or common +ground over time and coordinated so + + align:start position:0% +ground over time and coordinated so + + + align:start position:0% +ground over time and coordinated so +their communication could become more + + align:start position:0% +their communication could become more + + + align:start position:0% +their communication could become more +efficient and what they found is that + + align:start position:0% +efficient and what they found is that + + + align:start position:0% +efficient and what they found is that +when they had two New Yorkers who are + + align:start position:0% +when they had two New Yorkers who are + + + align:start position:0% +when they had two New Yorkers who are +interacting with each other they tended + + align:start position:0% +interacting with each other they tended + + + align:start position:0% +interacting with each other they tended +to very quickly do the tasks because + + align:start position:0% +to very quickly do the tasks because + + + align:start position:0% +to very quickly do the tasks because +they could just they could recognize + + align:start position:0% +they could just they could recognize + + + align:start position:0% +they could just they could recognize +immediately + + align:start position:0% +immediately + + + align:start position:0% +immediately +that person's in New Yorker and would + + align:start position:0% +that person's in New Yorker and would + + + align:start position:0% +that person's in New Yorker and would +just say things like oh it's going with + + align:start position:0% +just say things like oh it's going with + + + align:start position:0% +just say things like oh it's going with +Empire State Building + + align:start position:0% +Empire State Building + + + align:start position:0% +Empire State Building +whereas when they were talking to + + align:start position:0% +whereas when they were talking to + + + align:start position:0% +whereas when they were talking to +someone who wasn't in New Yorker they + + align:start position:0% +someone who wasn't in New Yorker they + + + align:start position:0% +someone who wasn't in New Yorker they +had to sort of ground the conversation + + align:start position:0% +had to sort of ground the conversation + + + align:start position:0% +had to sort of ground the conversation +by establishing these common reference + + align:start position:0% +by establishing these common reference + + + align:start position:0% +by establishing these common reference +before getting to this point and so they + + align:start position:0% +before getting to this point and so they + + + align:start position:0% +before getting to this point and so they +might start out with saying things like + + align:start position:0% +might start out with saying things like + + + align:start position:0% +might start out with saying things like +Oh from the move the one with the + + align:start position:0% +Oh from the move the one with the + + + align:start position:0% +Oh from the move the one with the +building with the pointy top and then + + align:start position:0% +building with the pointy top and then + + + align:start position:0% +building with the pointy top and then +eventually they would coordinate on what + + align:start position:0% +eventually they would coordinate on what + + + align:start position:0% +eventually they would coordinate on what +the actual labels for these up for these + + align:start position:0% +the actual labels for these up for these + + + align:start position:0% +the actual labels for these up for these +things were and so Clark's idea is that + + align:start position:0% +things were and so Clark's idea is that + + + align:start position:0% +things were and so Clark's idea is that +communication is really efficient we're + + align:start position:0% +communication is really efficient we're + + + align:start position:0% +communication is really efficient we're +able to do it in the way we are because + + align:start position:0% +able to do it in the way we are because + + + align:start position:0% +able to do it in the way we are because +we have because we're thinking about the + + align:start position:0% +we have because we're thinking about the + + + align:start position:0% +we have because we're thinking about the +common ground we have with other people + + align:start position:0% +common ground we have with other people + + + align:start position:0% +common ground we have with other people +and we're able to figure out what kind + + align:start position:0% +and we're able to figure out what kind + + + align:start position:0% +and we're able to figure out what kind +of common ground we have with others + + align:start position:0% +of common ground we have with others + + + align:start position:0% +of common ground we have with others +fairly quickly so if I'm interacting + + align:start position:0% +fairly quickly so if I'm interacting + + + align:start position:0% +fairly quickly so if I'm interacting +with one of you I might assume okay we + + align:start position:0% +with one of you I might assume okay we + + + align:start position:0% +with one of you I might assume okay we +both know a lot about cognitive science + + align:start position:0% +both know a lot about cognitive science + + + align:start position:0% +both know a lot about cognitive science +already so I can sort of start at a + + align:start position:0% +already so I can sort of start at a + + + align:start position:0% +already so I can sort of start at a +different level that I might start with + + align:start position:0% +different level that I might start with + + + align:start position:0% +different level that I might start with +say a child or someone who didn't know + + align:start position:0% +say a child or someone who didn't know + + + align:start position:0% +say a child or someone who didn't know +anything about this area and so this is + + align:start position:0% +anything about this area and so this is + + + align:start position:0% +anything about this area and so this is +an important piece of human + + align:start position:0% +an important piece of human + + + align:start position:0% +an important piece of human +communication that it seems like endless + + align:start position:0% +communication that it seems like endless + + + align:start position:0% +communication that it seems like endless +talked a little about this - it seems + + align:start position:0% +talked a little about this - it seems + + + align:start position:0% +talked a little about this - it seems +like infants are starting to show some + + align:start position:0% +like infants are starting to show some + + + align:start position:0% +like infants are starting to show some +signs of understanding the importance of + + align:start position:0% +signs of understanding the importance of + + + align:start position:0% +signs of understanding the importance of +common ground or shared knowledge and + + align:start position:0% +common ground or shared knowledge and + + + align:start position:0% +common ground or shared knowledge and +communication from a really early age + + align:start position:0% +communication from a really early age + + + align:start position:0% +communication from a really early age +but importantly this seems to come in + + align:start position:0% +but importantly this seems to come in + + + align:start position:0% +but importantly this seems to come in +around the same time that they're + + align:start position:0% +around the same time that they're + + + align:start position:0% +around the same time that they're +recognizing the importance of speakers + + align:start position:0% +recognizing the importance of speakers + + + align:start position:0% +recognizing the importance of speakers +facing each other in conversation and + + align:start position:0% +facing each other in conversation and + + + align:start position:0% +facing each other in conversation and +perhaps putting together some of their + + align:start position:0% +perhaps putting together some of their + + + align:start position:0% +perhaps putting together some of their +core knowledge domains which is around + + align:start position:0% +core knowledge domains which is around + + + align:start position:0% +core knowledge domains which is around +nine months to a year so this is really + + align:start position:0% +nine months to a year so this is really + + + align:start position:0% +nine months to a year so this is really +a lot of work on this and this domain + + align:start position:0% +a lot of work on this and this domain + + + align:start position:0% +a lot of work on this and this domain +has been done by Tomasello who showed + + align:start position:0% +has been done by Tomasello who showed + + + align:start position:0% +has been done by Tomasello who showed +that around nine months children were + + align:start position:0% +that around nine months children were + + + align:start position:0% +that around nine months children were +starting to do something different than + + align:start position:0% +starting to do something different than + + + align:start position:0% +starting to do something different than +they've been doing earlier so under nine + + align:start position:0% +they've been doing earlier so under nine + + + align:start position:0% +they've been doing earlier so under nine +months children tend to tend to they + + align:start position:0% +months children tend to tend to they + + + align:start position:0% +months children tend to tend to they +play with objects they interact with + + align:start position:0% +play with objects they interact with + + + align:start position:0% +play with objects they interact with +people but they don't seem to put these + + align:start position:0% +people but they don't seem to put these + + + align:start position:0% +people but they don't seem to put these +two things together whereas at nine + + align:start position:0% +two things together whereas at nine + + + align:start position:0% +two things together whereas at nine +months what they start doing is paying + + align:start position:0% +months what they start doing is paying + + + align:start position:0% +months what they start doing is paying +attention not just objects or to people + + align:start position:0% +attention not just objects or to people + + + align:start position:0% +attention not just objects or to people +but to object and people at the same + + align:start position:0% +but to object and people at the same + + + align:start position:0% +but to object and people at the same +time in the context of a joint + + align:start position:0% +time in the context of a joint + + + align:start position:0% +time in the context of a joint +interaction so they might do things like + + align:start position:0% +interaction so they might do things like + + + align:start position:0% +interaction so they might do things like +look at an object and then look at mom + + align:start position:0% +look at an object and then look at mom + + + align:start position:0% +look at an object and then look at mom +to make sure mom is also looking at it + + align:start position:0% +to make sure mom is also looking at it + + + align:start position:0% +to make sure mom is also looking at it +or they might point at things not just + + align:start position:0% +or they might point at things not just + + + align:start position:0% +or they might point at things not just +because they want the things as a + + align:start position:0% +because they want the things as a + + + align:start position:0% +because they want the things as a +younger child might do but in order only + + align:start position:0% +younger child might do but in order only + + + align:start position:0% +younger child might do but in order only +to share a tension with a parent or with + + align:start position:0% +to share a tension with a parent or with + + + align:start position:0% +to share a tension with a parent or with +someone else to point out that they're + + align:start position:0% +someone else to point out that they're + + + align:start position:0% +someone else to point out that they're +interested in something and to make sure + + align:start position:0% +interested in something and to make sure + + + align:start position:0% +interested in something and to make sure +that the parent is looking and is + + align:start position:0% +that the parent is looking and is + + + align:start position:0% +that the parent is looking and is +interested in it as well so Tomasello + + align:start position:0% +interested in it as well so Tomasello + + + align:start position:0% +interested in it as well so Tomasello +argues that this ability for engaging in + + align:start position:0% +argues that this ability for engaging in + + + align:start position:0% +argues that this ability for engaging in +joint attention sharing attention with + + align:start position:0% +joint attention sharing attention with + + + align:start position:0% +joint attention sharing attention with +someone + + align:start position:0% +someone + + + align:start position:0% +someone +to an object or external referent in the + + align:start position:0% +to an object or external referent in the + + + align:start position:0% +to an object or external referent in the +world is the foundation of linguistic + + align:start position:0% +world is the foundation of linguistic + + + align:start position:0% +world is the foundation of linguistic +communication and also cooperation and + + align:start position:0% +communication and also cooperation and + + + align:start position:0% +communication and also cooperation and +other very important human activities + + align:start position:0% +other very important human activities + + + align:start position:0% +other very important human activities +and it's certainly going to be important + + align:start position:0% +and it's certainly going to be important + + + align:start position:0% +and it's certainly going to be important +for an understanding of common ground + + align:start position:0% +for an understanding of common ground + + + align:start position:0% +for an understanding of common ground +which is important for communication so + + align:start position:0% +which is important for communication so + + + align:start position:0% +which is important for communication so +there's also evidence that around 12 + + align:start position:0% +there's also evidence that around 12 + + + align:start position:0% +there's also evidence that around 12 +months and then start to use prior + + align:start position:0% +months and then start to use prior + + + align:start position:0% +months and then start to use prior +shared experience to interpret + + align:start position:0% +shared experience to interpret + + + align:start position:0% +shared experience to interpret +communication I'm going to skip this I + + align:start position:0% +communication I'm going to skip this I + + + align:start position:0% +communication I'm going to skip this I +think but basically the idea well I'll + + align:start position:0% +think but basically the idea well I'll + + + align:start position:0% +think but basically the idea well I'll +just go through it quickly the idea is + + align:start position:0% +just go through it quickly the idea is + + + align:start position:0% +just go through it quickly the idea is +that infants will use the activities and + + align:start position:0% +that infants will use the activities and + + + align:start position:0% +that infants will use the activities and +objects that they've shared with people + + align:start position:0% +objects that they've shared with people + + + align:start position:0% +objects that they've shared with people +previously to figure out what the person + + align:start position:0% +previously to figure out what the person + + + align:start position:0% +previously to figure out what the person +means in a new case so if the infant + + align:start position:0% +means in a new case so if the infant + + + align:start position:0% +means in a new case so if the infant +interacts with one communicator with one + + align:start position:0% +interacts with one communicator with one + + + align:start position:0% +interacts with one communicator with one +toy and with another communicator with a + + align:start position:0% +toy and with another communicator with a + + + align:start position:0% +toy and with another communicator with a +different toy separately they will + + align:start position:0% +different toy separately they will + + + align:start position:0% +different toy separately they will +figure out the referent of a + + align:start position:0% +figure out the referent of a + + + align:start position:0% +figure out the referent of a +communicators ambiguous request by + + align:start position:0% +communicators ambiguous request by + + + align:start position:0% +communicators ambiguous request by +thinking about what information they've + + align:start position:0% +thinking about what information they've + + + align:start position:0% +thinking about what information they've +shared in the past so it seems like + + align:start position:0% +shared in the past so it seems like + + + align:start position:0% +shared in the past so it seems like +they're starting to track what kinds of + + align:start position:0% +they're starting to track what kinds of + + + align:start position:0% +they're starting to track what kinds of +knowledge is shared and what isn't in + + align:start position:0% +knowledge is shared and what isn't in + + + align:start position:0% +knowledge is shared and what isn't in +order to effectively communicate with + + align:start position:0% +order to effectively communicate with + + + align:start position:0% +order to effectively communicate with +others + + align:start position:0% + + + + align:start position:0% + +okay so there's a lot of other important + + align:start position:0% +okay so there's a lot of other important + + + align:start position:0% +okay so there's a lot of other important +questions about common ground but I'm + + align:start position:0% +questions about common ground but I'm + + + align:start position:0% +questions about common ground but I'm +gonna skip those now I just want to come + + align:start position:0% +gonna skip those now I just want to come + + + align:start position:0% +gonna skip those now I just want to come +back to the question of why this why + + align:start position:0% +back to the question of why this why + + + align:start position:0% +back to the question of why this why +infants understanding and children + + align:start position:0% +infants understanding and children + + + align:start position:0% +infants understanding and children +understanding of communication is + + align:start position:0% +understanding of communication is + + + align:start position:0% +understanding of communication is +important for understanding human + + align:start position:0% +important for understanding human + + + align:start position:0% +important for understanding human +intelligence so I think that one reason + + align:start position:0% +intelligence so I think that one reason + + + align:start position:0% +intelligence so I think that one reason +is that when you think about the + + align:start position:0% +is that when you think about the + + + align:start position:0% +is that when you think about the +insights these philosophers had and how + + align:start position:0% +insights these philosophers had and how + + + align:start position:0% +insights these philosophers had and how +we how they seem to be realized in very + + align:start position:0% +we how they seem to be realized in very + + + align:start position:0% +we how they seem to be realized in very +in fairly young infants early and + + align:start position:0% +in fairly young infants early and + + + align:start position:0% +in fairly young infants early and +children infants or early in development + + align:start position:0% +children infants or early in development + + + align:start position:0% +children infants or early in development +when you look at these abilities that + + align:start position:0% +when you look at these abilities that + + + align:start position:0% +when you look at these abilities that +humans have and even that there are + + align:start position:0% +humans have and even that there are + + + align:start position:0% +humans have and even that there are +young humans have and you compare them + + align:start position:0% +young humans have and you compare them + + + align:start position:0% +young humans have and you compare them +to what non-human animals are doing + + align:start position:0% +to what non-human animals are doing + + + align:start position:0% +to what non-human animals are doing +things look really different and so just + + align:start position:0% +things look really different and so just + + + align:start position:0% +things look really different and so just +briefly an animal communication we see + + align:start position:0% +briefly an animal communication we see + + + align:start position:0% +briefly an animal communication we see +some of the same kinds of features that + + align:start position:0% +some of the same kinds of features that + + + align:start position:0% +some of the same kinds of features that +we see in human communication so for one + + align:start position:0% +we see in human communication so for one + + + align:start position:0% +we see in human communication so for one +thing animal communication clearly has a + + align:start position:0% +thing animal communication clearly has a + + + align:start position:0% +thing animal communication clearly has a +social function in the same way that + + align:start position:0% +social function in the same way that + + + align:start position:0% +social function in the same way that +human communication does so it's + + align:start position:0% +human communication does so it's + + + align:start position:0% +human communication does so it's +socially rich in a number of ways I'm + + align:start position:0% +socially rich in a number of ways I'm + + + align:start position:0% +socially rich in a number of ways I'm +not going to go over specific species + + align:start position:0% +not going to go over specific species + + + align:start position:0% +not going to go over specific species +but just to gloss over it most animal + + align:start position:0% +but just to gloss over it most animal + + + align:start position:0% +but just to gloss over it most animal +communication is sensitive to the + + align:start position:0% +communication is sensitive to the + + + align:start position:0% +communication is sensitive to the +presence of an audience so it matters + + align:start position:0% +presence of an audience so it matters + + + align:start position:0% +presence of an audience so it matters +that someone's there to hear your + + align:start position:0% +that someone's there to hear your + + + align:start position:0% +that someone's there to hear your +communication for example species that + + align:start position:0% +communication for example species that + + + align:start position:0% +communication for example species that +produce alarm calls to warn others in + + align:start position:0% +produce alarm calls to warn others in + + + align:start position:0% +produce alarm calls to warn others in +their species in their group of + + align:start position:0% +their species in their group of + + + align:start position:0% +their species in their group of +predators will rarely produce these + + align:start position:0% +predators will rarely produce these + + + align:start position:0% +predators will rarely produce these +calls if there are no other members of + + align:start position:0% +calls if there are no other members of + + + align:start position:0% +calls if there are no other members of +their species present in many cases the + + align:start position:0% +their species present in many cases the + + + align:start position:0% +their species present in many cases the +sensitivity to the audience depends on + + align:start position:0% +sensitivity to the audience depends on + + + align:start position:0% +sensitivity to the audience depends on +the identity of the audience so for + + align:start position:0% +the identity of the audience so for + + + align:start position:0% +the identity of the audience so for +example in some species on such as + + align:start position:0% +example in some species on such as + + + align:start position:0% +example in some species on such as +ground squirrels they call much more in + + align:start position:0% +ground squirrels they call much more in + + + align:start position:0% +ground squirrels they call much more in +the presence of their kin than when + + align:start position:0% +the presence of their kin than when + + + align:start position:0% +the presence of their kin than when +their kin are not around or when there + + align:start position:0% +their kin are not around or when there + + + align:start position:0% +their kin are not around or when there +are other individuals there and in some + + align:start position:0% +are other individuals there and in some + + + align:start position:0% +are other individuals there and in some +cases it seems like there might actually + + align:start position:0% +cases it seems like there might actually + + + align:start position:0% +cases it seems like there might actually +even be a sensitivity to the knowledge + + align:start position:0% +even be a sensitivity to the knowledge + + + align:start position:0% +even be a sensitivity to the knowledge +state of the audience so this is looking + + align:start position:0% +state of the audience so this is looking + + + align:start position:0% +state of the audience so this is looking +a little more like the kind of + + align:start position:0% +a little more like the kind of + + + align:start position:0% +a little more like the kind of +sophisticated communication we see in + + align:start position:0% +sophisticated communication we see in + + + align:start position:0% +sophisticated communication we see in +humans so a wild chimpanzee for example + + align:start position:0% +humans so a wild chimpanzee for example + + + align:start position:0% +humans so a wild chimpanzee for example +will produce an alarm call will start to + + align:start position:0% +will produce an alarm call will start to + + + align:start position:0% +will produce an alarm call will start to +alarm call more if other chimpanzees + + align:start position:0% +alarm call more if other chimpanzees + + + align:start position:0% +alarm call more if other chimpanzees +come over who hadn't heard the original + + align:start position:0% +come over who hadn't heard the original + + + align:start position:0% +come over who hadn't heard the original +alarm call or who hadn't seen the + + align:start position:0% +alarm call or who hadn't seen the + + + align:start position:0% +alarm call or who hadn't seen the +predator but if everyone around has + + align:start position:0% +predator but if everyone around has + + + align:start position:0% +predator but if everyone around has +already seen it they'll reduce their + + align:start position:0% +already seen it they'll reduce their + + + align:start position:0% +already seen it they'll reduce their +alarm calling so it seems like they + + align:start position:0% +alarm calling so it seems like they + + + align:start position:0% +alarm calling so it seems like they +tailor it to how much information others + + align:start position:0% +tailor it to how much information others + + + align:start position:0% +tailor it to how much information others +around them have had + + align:start position:0% + + + + align:start position:0% + +however despite these really interesting + + align:start position:0% +however despite these really interesting + + + align:start position:0% +however despite these really interesting +ways in which animal communication is + + align:start position:0% +ways in which animal communication is + + + align:start position:0% +ways in which animal communication is +social and complex it's also limited in + + align:start position:0% +social and complex it's also limited in + + + align:start position:0% +social and complex it's also limited in +a number of ways that human + + align:start position:0% +a number of ways that human + + + align:start position:0% +a number of ways that human +communication is not so the eliciting + + align:start position:0% +communication is not so the eliciting + + + align:start position:0% +communication is not so the eliciting +stimuli for these communicative signals + + align:start position:0% +stimuli for these communicative signals + + + align:start position:0% +stimuli for these communicative signals +tend to be fairly limited I'll do the + + align:start position:0% +tend to be fairly limited I'll do the + + + align:start position:0% +tend to be fairly limited I'll do the +signals themselves so there tends to be + + align:start position:0% +signals themselves so there tends to be + + + align:start position:0% +signals themselves so there tends to be +sayin vervet monkeys one cry for a hawk + + align:start position:0% +sayin vervet monkeys one cry for a hawk + + + align:start position:0% +sayin vervet monkeys one cry for a hawk +and one cry for snake and they can't + + align:start position:0% +and one cry for snake and they can't + + + align:start position:0% +and one cry for snake and they can't +produce realize new signals for new + + align:start position:0% +produce realize new signals for new + + + align:start position:0% +produce realize new signals for new +kinds of predators and situations as in + + align:start position:0% +kinds of predators and situations as in + + + align:start position:0% +kinds of predators and situations as in +humans the receivers or in humans + + align:start position:0% +humans the receivers or in humans + + + align:start position:0% +humans the receivers or in humans +addressees acquire information from the + + align:start position:0% +addressees acquire information from the + + + align:start position:0% +addressees acquire information from the +signals of others but there's no + + align:start position:0% +signals of others but there's no + + + align:start position:0% +signals of others but there's no +evidence that this information tells the + + align:start position:0% +evidence that this information tells the + + + align:start position:0% +evidence that this information tells the +receivers in animal and animal species + + align:start position:0% +receivers in animal and animal species + + + align:start position:0% +receivers in animal and animal species +anything about the mental states of the + + align:start position:0% +anything about the mental states of the + + + align:start position:0% +anything about the mental states of the +communicator and additionally the + + align:start position:0% +communicator and additionally the + + + align:start position:0% +communicator and additionally the +communicator signals can often cause a + + align:start position:0% +communicator signals can often cause a + + + align:start position:0% +communicator signals can often cause a +response and receivers that's beneficial + + align:start position:0% +response and receivers that's beneficial + + + align:start position:0% +response and receivers that's beneficial +to the communicator for example they get + + align:start position:0% +to the communicator for example they get + + + align:start position:0% +to the communicator for example they get +a bump to indirect Fitness if their can + + align:start position:0% +a bump to indirect Fitness if their can + + + align:start position:0% +a bump to indirect Fitness if their can +run away and survive predators so there + + align:start position:0% +run away and survive predators so there + + + align:start position:0% +run away and survive predators so there +can be benefits of communication but + + align:start position:0% +can be benefits of communication but + + + align:start position:0% +can be benefits of communication but +there's no evidence that the + + align:start position:0% +there's no evidence that the + + + align:start position:0% +there's no evidence that the +communicator has any intention of + + align:start position:0% +communicator has any intention of + + + align:start position:0% +communicator has any intention of +changing the receivers mental state so + + align:start position:0% +changing the receivers mental state so + + + align:start position:0% +changing the receivers mental state so +there's really no evidence of this sort + + align:start position:0% +there's really no evidence of this sort + + + align:start position:0% +there's really no evidence of this sort +of speaker meaning or this special kind + + align:start position:0% +of speaker meaning or this special kind + + + align:start position:0% +of speaker meaning or this special kind +of communication communicative intention + + align:start position:0% +of communication communicative intention + + + align:start position:0% +of communication communicative intention +we see in humans which is that a + + align:start position:0% +we see in humans which is that a + + + align:start position:0% +we see in humans which is that a +communicator doesn't just intend for the + + align:start position:0% +communicator doesn't just intend for the + + + align:start position:0% +communicator doesn't just intend for the +addressee to respond in a particular way + + align:start position:0% +addressee to respond in a particular way + + + align:start position:0% +addressee to respond in a particular way +but intends for the address effort the + + align:start position:0% +but intends for the address effort the + + + align:start position:0% +but intends for the address effort the +audience to respond in a particular way + + align:start position:0% +audience to respond in a particular way + + + align:start position:0% +audience to respond in a particular way +by virtue of having understood the + + align:start position:0% +by virtue of having understood the + + + align:start position:0% +by virtue of having understood the +intention of that communication and so + + align:start position:0% +intention of that communication and so + + + align:start position:0% +intention of that communication and so +this is just a I think particularly well + + align:start position:0% +this is just a I think particularly well + + + align:start position:0% +this is just a I think particularly well +worded quote from Seaforth and Cheney + + align:start position:0% +worded quote from Seaforth and Cheney + + + align:start position:0% +worded quote from Seaforth and Cheney +who say basically that listeners can + + align:start position:0% +who say basically that listeners can + + + align:start position:0% +who say basically that listeners can +acquire information from signalers but + + align:start position:0% +acquire information from signalers but + + + align:start position:0% +acquire information from signalers but +the signalers themselves don't in the + + align:start position:0% +the signalers themselves don't in the + + + align:start position:0% +the signalers themselves don't in the +human sense intend to provide that + + align:start position:0% +human sense intend to provide that + + + align:start position:0% +human sense intend to provide that +information so yeah so the reason really + + align:start position:0% +information so yeah so the reason really + + + align:start position:0% +information so yeah so the reason really +for this contrast between the human and + + align:start position:0% +for this contrast between the human and + + + align:start position:0% +for this contrast between the human and +animal cases that I think if we want to + + align:start position:0% +animal cases that I think if we want to + + + align:start position:0% +animal cases that I think if we want to +build a model of human communication we + + align:start position:0% +build a model of human communication we + + + align:start position:0% +build a model of human communication we +need it to we need to differentiate it + + align:start position:0% +need it to we need to differentiate it + + + align:start position:0% +need it to we need to differentiate it +from other kinds of communicative models + + align:start position:0% +from other kinds of communicative models + + + align:start position:0% +from other kinds of communicative models +we could have and we also needed to + + align:start position:0% +we could have and we also needed to + + + align:start position:0% +we could have and we also needed to +develop the types of abilities that + + align:start position:0% +develop the types of abilities that + + + align:start position:0% +develop the types of abilities that +human infants have taking into account + + align:start position:0% +human infants have taking into account + + + align:start position:0% +human infants have taking into account +the resources that infants start out + + align:start position:0% +the resources that infants start out + + + align:start position:0% +the resources that infants start out +with and the developments that we see in + + align:start position:0% +with and the developments that we see in + + + align:start position:0% +with and the developments that we see in +the first few years of life so if not + + align:start position:0% +the first few years of life so if not + + + align:start position:0% +the first few years of life so if not +going to be enough to have agents that + + align:start position:0% +going to be enough to have agents that + + + align:start position:0% +going to be enough to have agents that +can influence each other's responses or + + align:start position:0% +can influence each other's responses or + + + align:start position:0% +can influence each other's responses or +who can understand language because it + + align:start position:0% +who can understand language because it + + + align:start position:0% +who can understand language because it +seems like the recognition of these more + + align:start position:0% +seems like the recognition of these more + + + align:start position:0% +seems like the recognition of these more +abstract features of communication and + + align:start position:0% +abstract features of communication and + + + align:start position:0% +abstract features of communication and +its causal effects on mental states is + + align:start position:0% +its causal effects on mental states is + + + align:start position:0% +its causal effects on mental states is +actually present fairly + + align:start position:0% +actually present fairly + + + align:start position:0% +actually present fairly +early on as well and I think just + + align:start position:0% +early on as well and I think just + + + align:start position:0% +early on as well and I think just +relating this back to Liz's theory that + + align:start position:0% +relating this back to Liz's theory that + + + align:start position:0% +relating this back to Liz's theory that +we have the infant's might have these + + align:start position:0% +we have the infant's might have these + + + align:start position:0% +we have the infant's might have these +different systems for agents + + align:start position:0% +different systems for agents + + + align:start position:0% +different systems for agents +understanding agents and their actions + + align:start position:0% +understanding agents and their actions + + + align:start position:0% +understanding agents and their actions +on object and then for social being than + + align:start position:0% +on object and then for social being than + + + align:start position:0% +on object and then for social being than +their interactions with each other it + + align:start position:0% +their interactions with each other it + + + align:start position:0% +their interactions with each other it +seems like communication and this type + + align:start position:0% +seems like communication and this type + + + align:start position:0% +seems like communication and this type +of communicative intention that we see + + align:start position:0% +of communicative intention that we see + + + align:start position:0% +of communicative intention that we see +sort of combines these two kinds of + + align:start position:0% +sort of combines these two kinds of + + + align:start position:0% +sort of combines these two kinds of +things where you have an intention to + + align:start position:0% +things where you have an intention to + + + align:start position:0% +things where you have an intention to +produce an effect on someone else but by + + align:start position:0% +produce an effect on someone else but by + + + align:start position:0% +produce an effect on someone else but by +virtue of them understanding the mental + + align:start position:0% +virtue of them understanding the mental + + + align:start position:0% +virtue of them understanding the mental +states that you have toward the world + + align:start position:0% +states that you have toward the world + + + align:start position:0% +states that you have toward the world +and as well as toward them so and maybe + + align:start position:0% +and as well as toward them so and maybe + + + align:start position:0% +and as well as toward them so and maybe +it's the combining of these different + + align:start position:0% +it's the combining of these different + + + align:start position:0% +it's the combining of these different +domains that that helps infants put + + align:start position:0% +domains that that helps infants put + + + align:start position:0% +domains that that helps infants put +together they're possibly human unique + + align:start position:0% +together they're possibly human unique + + + align:start position:0% +together they're possibly human unique +but maybe not communication skills + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/lCKxeRiBdjQ.txt b/lCKxeRiBdjQ.txt new file mode 100644 index 0000000000000000000000000000000000000000..4eb5bc69d94c94cb71e327234521c3cb747318c5 --- /dev/null +++ b/lCKxeRiBdjQ.txt @@ -0,0 +1,1691 @@ +align:start position:0% + +welcome back to recitation in this video + + align:start position:0% +welcome back to recitation in this video + + + align:start position:0% +welcome back to recitation in this video +I'd like us to work on the following + + align:start position:0% +I'd like us to work on the following + + + align:start position:0% +I'd like us to work on the following +problem so given the region R shown + + align:start position:0% +problem so given the region R shown + + + align:start position:0% +problem so given the region R shown +below which I'll mention more of in a + + align:start position:0% +below which I'll mention more of in a + + + align:start position:0% +below which I'll mention more of in a +moment compute the integral double + + align:start position:0% +moment compute the integral double + + + align:start position:0% +moment compute the integral double +integral over R of the quantity 4x^2 - + + align:start position:0% +integral over R of the quantity 4x^2 - + + + align:start position:0% +integral over R of the quantity 4x^2 - +i^ 2 y^2 sorry to the 4th DX Dy and I + + align:start position:0% +i^ 2 y^2 sorry to the 4th DX Dy and I + + + align:start position:0% +i^ 2 y^2 sorry to the 4th DX Dy and I +want you to do it by changing variables + + align:start position:0% +want you to do it by changing variables + + + align:start position:0% +want you to do it by changing variables +to U is equal to 2x - Y and V is Al to + + align:start position:0% +to U is equal to 2x - Y and V is Al to + + + align:start position:0% +to U is equal to 2x - Y and V is Al to +2x + y and the region defined down here + + align:start position:0% +2x + y and the region defined down here + + + align:start position:0% +2x + y and the region defined down here +is just the these three line segments in + + align:start position:0% +is just the these three line segments in + + + align:start position:0% +is just the these three line segments in +their the intersection of the of the + + align:start position:0% +their the intersection of the of the + + + align:start position:0% +their the intersection of the of the +region uh bounded by these three line + + align:start position:0% +region uh bounded by these three line + + + align:start position:0% +region uh bounded by these three line +segments so one of them is a portion of + + align:start position:0% +segments so one of them is a portion of + + + align:start position:0% +segments so one of them is a portion of +the y- axis one of them is a portion of + + align:start position:0% +the y- axis one of them is a portion of + + + align:start position:0% +the y- axis one of them is a portion of +the line defined by 2x - yal 0 and one + + align:start position:0% +the line defined by 2x - yal 0 and one + + + align:start position:0% +the line defined by 2x - yal 0 and one +of them is a portion of the line defined + + align:start position:0% +of them is a portion of the line defined + + + align:start position:0% +of them is a portion of the line defined +by 2x + Y = 2 + + align:start position:0% +by 2x + Y = 2 + + + align:start position:0% +by 2x + Y = 2 +so why don't you do this make make sure + + align:start position:0% +so why don't you do this make make sure + + + align:start position:0% +so why don't you do this make make sure +you use this change of variables and + + align:start position:0% +you use this change of variables and + + + align:start position:0% +you use this change of variables and +then I'll come back and I'll draw uh the + + align:start position:0% +then I'll come back and I'll draw uh the + + + align:start position:0% +then I'll come back and I'll draw uh the +accompanying region in the UV plane and + + align:start position:0% +accompanying region in the UV plane and + + + align:start position:0% +accompanying region in the UV plane and +then we'll see uh how how I set it + + align:start position:0% + + + + align:start position:0% + +up okay welcome back well the first + + align:start position:0% +up okay welcome back well the first + + + align:start position:0% +up okay welcome back well the first +thing I'm going to do is I'm going to + + align:start position:0% +thing I'm going to do is I'm going to + + + align:start position:0% +thing I'm going to do is I'm going to +draw the region in the UV plane that is + + align:start position:0% +draw the region in the UV plane that is + + + align:start position:0% +draw the region in the UV plane that is +determined by this region in the XY + + align:start position:0% +determined by this region in the XY + + + align:start position:0% +determined by this region in the XY +plane and the ch change of variables now + + align:start position:0% +plane and the ch change of variables now + + + align:start position:0% +plane and the ch change of variables now +as was mentioned in the lecture uh all + + align:start position:0% +as was mentioned in the lecture uh all + + + align:start position:0% +as was mentioned in the lecture uh all +of the changes are linear and so I'm + + align:start position:0% +of the changes are linear and so I'm + + + align:start position:0% +of the changes are linear and so I'm +going to be taking lines to lines so + + align:start position:0% +going to be taking lines to lines so + + + align:start position:0% +going to be taking lines to lines so +what I'm going to do is determine uh at + + align:start position:0% +what I'm going to do is determine uh at + + + align:start position:0% +what I'm going to do is determine uh at +each end point here where that end point + + align:start position:0% +each end point here where that end point + + + align:start position:0% +each end point here where that end point +goes under the transformation and then I + + align:start position:0% +goes under the transformation and then I + + + align:start position:0% +goes under the transformation and then I +will connect the dots so what do I get + + align:start position:0% +will connect the dots so what do I get + + + align:start position:0% +will connect the dots so what do I get +well this first one is0 0 for x and y + + align:start position:0% +well this first one is0 0 for x and y + + + align:start position:0% +well this first one is0 0 for x and y +and so that corresponds to X and Y are + + align:start position:0% +and so that corresponds to X and Y are + + + align:start position:0% +and so that corresponds to X and Y are +zero and here so U is zero and X and Y + + align:start position:0% +zero and here so U is zero and X and Y + + + align:start position:0% +zero and here so U is zero and X and Y +are zero here so V is zero so that's the + + align:start position:0% +are zero here so V is zero so that's the + + + align:start position:0% +are zero here so V is zero so that's the +point Z 0 on the UV plane now I want to + + align:start position:0% +point Z 0 on the UV plane now I want to + + + align:start position:0% +point Z 0 on the UV plane now I want to +mention something here is that based on + + align:start position:0% +mention something here is that based on + + + align:start position:0% +mention something here is that based on +how these lines were defined this is + + align:start position:0% +how these lines were defined this is + + + align:start position:0% +how these lines were defined this is +telling you that all along this line 2x + + align:start position:0% +telling you that all along this line 2x + + + align:start position:0% +telling you that all along this line 2x +- y equal 0 that means U is equal to Zer + + align:start position:0% +- y equal 0 that means U is equal to Zer + + + align:start position:0% +- y equal 0 that means U is equal to Zer +all along that segment and if you'll + + align:start position:0% +all along that segment and if you'll + + + align:start position:0% +all along that segment and if you'll +notice also 2x + y is equal to 2 here so + + align:start position:0% +notice also 2x + y is equal to 2 here so + + + align:start position:0% +notice also 2x + y is equal to 2 here so +V is equal to two all along this segment + + align:start position:0% +V is equal to two all along this segment + + + align:start position:0% +V is equal to two all along this segment +so we should expect whatever U is V is + + align:start position:0% +so we should expect whatever U is V is + + + align:start position:0% +so we should expect whatever U is V is +going to be two here and whatever V is + + align:start position:0% +going to be two here and whatever V is + + + align:start position:0% +going to be two here and whatever V is +here U is going to be zero okay + + align:start position:0% +here U is going to be zero okay + + + align:start position:0% +here U is going to be zero okay +so I'm going to have something with u0 + + align:start position:0% +so I'm going to have something with u0 + + + align:start position:0% +so I'm going to have something with u0 +initially and then V2 I can already + + align:start position:0% +initially and then V2 I can already + + + align:start position:0% +initially and then V2 I can already +expect it's going to come up here and + + align:start position:0% +expect it's going to come up here and + + + align:start position:0% +expect it's going to come up here and +move over that way but let's just check + + align:start position:0% +move over that way but let's just check + + + align:start position:0% +move over that way but let's just check +so this is the point + + align:start position:0% +so this is the point + + + align:start position:0% +so this is the point +020 for x and two for y let's see what + + align:start position:0% +020 for x and two for y let's see what + + + align:start position:0% +020 for x and two for y let's see what +it is in the uh UV variables so u in + + align:start position:0% +it is in the uh UV variables so u in + + + align:start position:0% +it is in the uh UV variables so u in +that case is -2 and v in that case is + + align:start position:0% +that case is -2 and v in that case is + + + align:start position:0% +that case is -2 and v in that case is +two and so I'm going to go left two and + + align:start position:0% +two and so I'm going to go left two and + + + align:start position:0% +two and so I'm going to go left two and +up + + align:start position:0% +up + + + align:start position:0% +up +two this might not be drawn to scale but + + align:start position:0% +two this might not be drawn to scale but + + + align:start position:0% +two this might not be drawn to scale but +this is -2 + + align:start position:0% +this is -2 + + + align:start position:0% +this is -2 +and this is up two here and so that's + + align:start position:0% +and this is up two here and so that's + + + align:start position:0% +and this is up two here and so that's +where this point goes under the + + align:start position:0% +where this point goes under the + + + align:start position:0% +where this point goes under the +transformation and this point is2 comma + + align:start position:0% +transformation and this point is2 comma + + + align:start position:0% +transformation and this point is2 comma +2 1 half comma 1 you can actually check + + align:start position:0% +2 1 half comma 1 you can actually check + + + align:start position:0% +2 1 half comma 1 you can actually check +what it is but actually as I mentioned + + align:start position:0% +what it is but actually as I mentioned + + + align:start position:0% +what it is but actually as I mentioned +you already know what has to happen + + align:start position:0% +you already know what has to happen + + + align:start position:0% +you already know what has to happen +because this segment is connected right + + align:start position:0% + + + + align:start position:0% + +here and then we said all along this + + align:start position:0% +here and then we said all along this + + + align:start position:0% +here and then we said all along this +line V is two + + align:start position:0% + + + + align:start position:0% + +and all along this line U is zero and so + + align:start position:0% +and all along this line U is zero and so + + + align:start position:0% +and all along this line U is zero and so +that actually carves out that rectangle + + align:start position:0% +that actually carves out that rectangle + + + align:start position:0% +that actually carves out that rectangle +so if you were worried and you didn't + + align:start position:0% +so if you were worried and you didn't + + + align:start position:0% +so if you were worried and you didn't +you weren't able to do it that way what + + align:start position:0% +you weren't able to do it that way what + + + align:start position:0% +you weren't able to do it that way what +you could actually do is say well where + + align:start position:0% +you could actually do is say well where + + + align:start position:0% +you could actually do is say well where +does the point one2 one go if I plug in + + align:start position:0% +does the point one2 one go if I plug in + + + align:start position:0% +does the point one2 one go if I plug in +1/2 for x and one for y I notice that I + + align:start position:0% +1/2 for x and one for y I notice that I + + + align:start position:0% +1/2 for x and one for y I notice that I +get U equal 0 and V equals 2 and that's + + align:start position:0% +get U equal 0 and V equals 2 and that's + + + align:start position:0% +get U equal 0 and V equals 2 and that's +this point and so now I'm looking at + + align:start position:0% +this point and so now I'm looking at + + + align:start position:0% +this point and so now I'm looking at +this region now these two things are not + + align:start position:0% +this region now these two things are not + + + align:start position:0% +this region now these two things are not +drawn to scale because what I want to + + align:start position:0% +drawn to scale because what I want to + + + align:start position:0% +drawn to scale because what I want to +point out is they're both triangles it's + + align:start position:0% +point out is they're both triangles it's + + + align:start position:0% +point out is they're both triangles it's +easy to find the area based on how + + align:start position:0% +easy to find the area based on how + + + align:start position:0% +easy to find the area based on how +they're they sitting in two-dimensional + + align:start position:0% +they're they sitting in two-dimensional + + + align:start position:0% +they're they sitting in two-dimensional +space so what we see here is if I wanted + + align:start position:0% +space so what we see here is if I wanted + + + align:start position:0% +space so what we see here is if I wanted +to find the area of this triangle let's + + align:start position:0% +to find the area of this triangle let's + + + align:start position:0% +to find the area of this triangle let's +make this the base that base is two and + + align:start position:0% +make this the base that base is two and + + + align:start position:0% +make this the base that base is two and +the height is 1/2 so 1/2 of Base times + + align:start position:0% +the height is 1/2 so 1/2 of Base times + + + align:start position:0% +the height is 1/2 so 1/2 of Base times +height is that area is equal to 1/2 so + + align:start position:0% +height is that area is equal to 1/2 so + + + align:start position:0% +height is that area is equal to 1/2 so +the area of R is 1/2 and what's the area + + align:start position:0% +the area of R is 1/2 and what's the area + + + align:start position:0% +the area of R is 1/2 and what's the area +of this one the area of this one is well + + align:start position:0% +of this one the area of this one is well + + + align:start position:0% +of this one the area of this one is well +I've got uh base two and height two and + + align:start position:0% +I've got uh base two and height two and + + + align:start position:0% +I've got uh base two and height two and +so it's one2 of 2 * 2 and so that gives + + align:start position:0% +so it's one2 of 2 * 2 and so that gives + + + align:start position:0% +so it's one2 of 2 * 2 and so that gives +me area is two so here the area is 1/2 + + align:start position:0% +me area is two so here the area is 1/2 + + + align:start position:0% +me area is two so here the area is 1/2 +here the area is is two and so notice + + align:start position:0% +here the area is is two and so notice + + + align:start position:0% +here the area is is two and so notice +that I've multiplied by four to get from + + align:start position:0% +that I've multiplied by four to get from + + + align:start position:0% +that I've multiplied by four to get from +here to here so I can anticipate that I + + align:start position:0% +here to here so I can anticipate that I + + + align:start position:0% +here to here so I can anticipate that I +should have based on the the principle + + align:start position:0% +should have based on the the principle + + + align:start position:0% +should have based on the the principle +you saw in lecture I should have + + align:start position:0% +you saw in lecture I should have + + + align:start position:0% +you saw in lecture I should have +something like dudv is going to equal 4 + + align:start position:0% +something like dudv is going to equal 4 + + + align:start position:0% +something like dudv is going to equal 4 +* + + align:start position:0% +* + + + align:start position:0% +* +dxdy that is what I expect to get now + + align:start position:0% +dxdy that is what I expect to get now + + + align:start position:0% +dxdy that is what I expect to get now +let's see if when we do the the Jacobian + + align:start position:0% +let's see if when we do the the Jacobian + + + align:start position:0% +let's see if when we do the the Jacobian +we get the same thing let me double + + align:start position:0% +we get the same thing let me double + + + align:start position:0% +we get the same thing let me double +check right this is this is area two + + align:start position:0% +check right this is this is area two + + + align:start position:0% +check right this is this is area two +this is area 1/2 so I have 1/2 * 4 is + + align:start position:0% +this is area 1/2 so I have 1/2 * 4 is + + + align:start position:0% +this is area 1/2 so I have 1/2 * 4 is +going to give me two yeah that's what I + + align:start position:0% +going to give me two yeah that's what I + + + align:start position:0% +going to give me two yeah that's what I +should get okay + + align:start position:0% +should get okay + + + align:start position:0% +should get okay +okay oops that sticks out a little so + + align:start position:0% +okay oops that sticks out a little so + + + align:start position:0% +okay oops that sticks out a little so +now let's just check our check our + + align:start position:0% +now let's just check our check our + + + align:start position:0% +now let's just check our check our +Jacobian and see if that is indeed what + + align:start position:0% +Jacobian and see if that is indeed what + + + align:start position:0% +Jacobian and see if that is indeed what +we get okay so I'm going to look at uh u + + align:start position:0% +we get okay so I'm going to look at uh u + + + align:start position:0% +we get okay so I'm going to look at uh u +subx u + + align:start position:0% +subx u + + + align:start position:0% +subx u +suby v subx v suby right so U subx is 2 + + align:start position:0% +suby v subx v suby right so U subx is 2 + + + align:start position:0% +suby v subx v suby right so U subx is 2 +U sub y is 1 so I get + + align:start position:0% +U sub y is 1 so I get + + + align:start position:0% +U sub y is 1 so I get +21 V subx is 2 V sub y is 1 so I get 2 1 + + align:start position:0% +21 V subx is 2 V sub y is 1 so I get 2 1 + + + align:start position:0% +21 V subx is 2 V sub y is 1 so I get 2 1 +2 * 1 is 2 + + align:start position:0% +2 * 1 is 2 + + + align:start position:0% +2 * 1 is 2 +minus -2 gives me indeed four so I do + + align:start position:0% +minus -2 gives me indeed four so I do + + + align:start position:0% +minus -2 gives me indeed four so I do +get in fact du DV is equal to 4 + + align:start position:0% +get in fact du DV is equal to 4 + + + align:start position:0% +get in fact du DV is equal to 4 +dxdy so I know that I'm going to have to + + align:start position:0% +dxdy so I know that I'm going to have to + + + align:start position:0% +dxdy so I know that I'm going to have to +because I'm changing variables though + + align:start position:0% +because I'm changing variables though + + + align:start position:0% +because I'm changing variables though +from dxdy to duv I'm going to divide by + + align:start position:0% +from dxdy to duv I'm going to divide by + + + align:start position:0% +from dxdy to duv I'm going to divide by +four obviously when I do the + + align:start position:0% +four obviously when I do the + + + align:start position:0% +four obviously when I do the +substitution the substitution will be + + align:start position:0% +substitution the substitution will be + + + align:start position:0% +substitution the substitution will be +replacing just + + align:start position:0% +replacing just + + + align:start position:0% +replacing just +dxdy so I just mentioned that but notice + + align:start position:0% +dxdy so I just mentioned that but notice + + + align:start position:0% +dxdy so I just mentioned that but notice +again we get what we expect to get we + + align:start position:0% +again we get what we expect to get we + + + align:start position:0% +again we get what we expect to get we +got a four based on the the the picture + + align:start position:0% +got a four based on the the the picture + + + align:start position:0% +got a four based on the the the picture +and we get a four based on the + + align:start position:0% +and we get a four based on the + + + align:start position:0% +and we get a four based on the +Jacobian and so now we we need to finish + + align:start position:0% +Jacobian and so now we we need to finish + + + align:start position:0% +Jacobian and so now we we need to finish +up the process we need to figure out how + + align:start position:0% +up the process we need to figure out how + + + align:start position:0% +up the process we need to figure out how +to write this in terms of u and v and + + align:start position:0% +to write this in terms of u and v and + + + align:start position:0% +to write this in terms of u and v and +then figure out our bounds in terms of u + + align:start position:0% +then figure out our bounds in terms of u + + + align:start position:0% +then figure out our bounds in terms of u +and v and then we're done okay so let me + + align:start position:0% +and v and then we're done okay so let me + + + align:start position:0% +and v and then we're done okay so let me +mention one thing you should notice is + + align:start position:0% +mention one thing you should notice is + + + align:start position:0% +mention one thing you should notice is +that U * V is equal to exactly this is a + + align:start position:0% +that U * V is equal to exactly this is a + + + align:start position:0% +that U * V is equal to exactly this is a +this is going to be a difference of two + + align:start position:0% +this is going to be a difference of two + + + align:start position:0% +this is going to be a difference of two +squares and it is precisely 4x^2 minus + + align:start position:0% +squares and it is precisely 4x^2 minus + + + align:start position:0% +squares and it is precisely 4x^2 minus +y^2 if you need to multiply it out to + + align:start position:0% +y^2 if you need to multiply it out to + + + align:start position:0% +y^2 if you need to multiply it out to +check that's you can check it but that's + + align:start position:0% +check that's you can check it but that's + + + align:start position:0% +check that's you can check it but that's +indeed what it is which is why this + + align:start position:0% +indeed what it is which is why this + + + align:start position:0% +indeed what it is which is why this +particular substitution is quite nice + + align:start position:0% +particular substitution is quite nice + + + align:start position:0% +particular substitution is quite nice +because that means this function I'm + + align:start position:0% +because that means this function I'm + + + align:start position:0% +because that means this function I'm +supposed to be integrating is just UV + + align:start position:0% +supposed to be integrating is just UV + + + align:start position:0% +supposed to be integrating is just UV +raised to 4th so I'm almost done so let + + align:start position:0% +raised to 4th so I'm almost done so let + + + align:start position:0% +raised to 4th so I'm almost done so let +me write in the pieces I know and then + + align:start position:0% +me write in the pieces I know and then + + + align:start position:0% +me write in the pieces I know and then +we'll fill in the last two spots or four + + align:start position:0% +we'll fill in the last two spots or four + + + align:start position:0% +we'll fill in the last two spots or four +spots which will be all the bounds on + + align:start position:0% +spots which will be all the bounds on + + + align:start position:0% +spots which will be all the bounds on +the integral so I'm going to write it + + align:start position:0% +the integral so I'm going to write it + + + align:start position:0% +the integral so I'm going to write it +here give myself some space to write the + + align:start position:0% +here give myself some space to write the + + + align:start position:0% +here give myself some space to write the +bounds and then so I'm replacing the + + align:start position:0% +bounds and then so I'm replacing the + + + align:start position:0% +bounds and then so I'm replacing the +4x^2 minus y^2 by a UV so I'm going to + + align:start position:0% +4x^2 minus y^2 by a UV so I'm going to + + + align:start position:0% +4x^2 minus y^2 by a UV so I'm going to +get U * V and then the function is + + align:start position:0% +get U * V and then the function is + + + align:start position:0% +get U * V and then the function is +raised that is raised to the 4th in the + + align:start position:0% +raised that is raised to the 4th in the + + + align:start position:0% +raised that is raised to the 4th in the +in the initial problem so I raise that + + align:start position:0% +in the initial problem so I raise that + + + align:start position:0% +in the initial problem so I raise that +to the fourth then dxdy as I mentioned + + align:start position:0% +to the fourth then dxdy as I mentioned + + + align:start position:0% +to the fourth then dxdy as I mentioned +will be replaced by a DV / 4 and so I + + align:start position:0% +will be replaced by a DV / 4 and so I + + + align:start position:0% +will be replaced by a DV / 4 and so I +can just put this over four and write uh + + align:start position:0% +can just put this over four and write uh + + + align:start position:0% +can just put this over four and write uh +duv well I should be careful which order + + align:start position:0% +duv well I should be careful which order + + + align:start position:0% +duv well I should be careful which order +I want to do doesn't really matter I can + + align:start position:0% +I want to do doesn't really matter I can + + + align:start position:0% +I want to do doesn't really matter I can +do either + + align:start position:0% +do either + + + align:start position:0% +do either +one du DV okay and so now I want to know + + align:start position:0% +one du DV okay and so now I want to know + + + align:start position:0% +one du DV okay and so now I want to know +what U goes from and to and then what V + + align:start position:0% +what U goes from and to and then what V + + + align:start position:0% +what U goes from and to and then what V +has to go from and to so if I come over + + align:start position:0% +has to go from and to so if I come over + + + align:start position:0% +has to go from and to so if I come over +here you'll see it didn't matter because + + align:start position:0% +here you'll see it didn't matter because + + + align:start position:0% +here you'll see it didn't matter because +I could have picked either direction to + + align:start position:0% +I could have picked either direction to + + + align:start position:0% +I could have picked either direction to +go but if I'm going to go + + align:start position:0% +go but if I'm going to go + + + align:start position:0% +go but if I'm going to go +with u I'm coming from whatever this + + align:start position:0% +with u I'm coming from whatever this + + + align:start position:0% +with u I'm coming from whatever this +function is over to here right and this + + align:start position:0% +function is over to here right and this + + + align:start position:0% +function is over to here right and this +value here is easy that's U equals 0 so + + align:start position:0% +value here is easy that's U equals 0 so + + + align:start position:0% +value here is easy that's U equals 0 so +the top Bound for U is zero and the + + align:start position:0% +the top Bound for U is zero and the + + + align:start position:0% +the top Bound for U is zero and the +bottom Bound for U this is V is equal to + + align:start position:0% +bottom Bound for U this is V is equal to + + + align:start position:0% +bottom Bound for U this is V is equal to +minus U so the bottom Bound for U is + + align:start position:0% +minus U so the bottom Bound for U is + + + align:start position:0% +minus U so the bottom Bound for U is +When U is equal to negative V so I'm + + align:start position:0% +When U is equal to negative V so I'm + + + align:start position:0% +When U is equal to negative V so I'm +running from because I put the DU on the + + align:start position:0% +running from because I put the DU on the + + + align:start position:0% +running from because I put the DU on the +inside my first one is running from + + align:start position:0% +inside my first one is running from + + + align:start position:0% +inside my first one is running from +minus V to what did I say zero and then + + align:start position:0% +minus V to what did I say zero and then + + + align:start position:0% +minus V to what did I say zero and then +the V values from there go between zero + + align:start position:0% +the V values from there go between zero + + + align:start position:0% +the V values from there go between zero +and two you can see this easily from the + + align:start position:0% +and two you can see this easily from the + + + align:start position:0% +and two you can see this easily from the +picture so they go between Z and + + align:start position:0% +picture so they go between Z and + + + align:start position:0% +picture so they go between Z and +two and I am not going to finish it off + + align:start position:0% +two and I am not going to finish it off + + + align:start position:0% +two and I am not going to finish it off +from here because it would require not + + align:start position:0% +from here because it would require not + + + align:start position:0% +from here because it would require not +too much work it's actually quite simple + + align:start position:0% +too much work it's actually quite simple + + + align:start position:0% +too much work it's actually quite simple +because it's just it's just a polinomial + + align:start position:0% +because it's just it's just a polinomial + + + align:start position:0% +because it's just it's just a polinomial +in U and a polinomial in V but there are + + align:start position:0% +in U and a polinomial in V but there are + + + align:start position:0% +in U and a polinomial in V but there are +a lot of powers and there will be big + + align:start position:0% +a lot of powers and there will be big + + + align:start position:0% +a lot of powers and there will be big +powers of two so suffice it to say at + + align:start position:0% +powers of two so suffice it to say at + + + align:start position:0% +powers of two so suffice it to say at +this point we can evaluate this integral + + align:start position:0% +this point we can evaluate this integral + + + align:start position:0% +this point we can evaluate this integral +and it's quite easy to evaluate and the + + align:start position:0% +and it's quite easy to evaluate and the + + + align:start position:0% +and it's quite easy to evaluate and the +main point I think we should make is how + + align:start position:0% +main point I think we should make is how + + + align:start position:0% +main point I think we should make is how +did it make it simpler I mean the the + + align:start position:0% +did it make it simpler I mean the the + + + align:start position:0% +did it make it simpler I mean the the +initial problem if we come over + + align:start position:0% +initial problem if we come over + + + align:start position:0% +initial problem if we come over +here this is annoying to to find an + + align:start position:0% +here this is annoying to to find an + + + align:start position:0% +here this is annoying to to find an +anti-derivative but not impossible but + + align:start position:0% +anti-derivative but not impossible but + + + align:start position:0% +anti-derivative but not impossible but +the really annoying part is kind of I + + align:start position:0% +the really annoying part is kind of I + + + align:start position:0% +the really annoying part is kind of I +would have to take this region and split + + align:start position:0% +would have to take this region and split + + + align:start position:0% +would have to take this region and split +it into a bunch of pieces or at least + + align:start position:0% +it into a bunch of pieces or at least + + + align:start position:0% +it into a bunch of pieces or at least +two pieces to to evaluate the integral + + align:start position:0% +two pieces to to evaluate the integral + + + align:start position:0% +two pieces to to evaluate the integral +in a reasonable way or my yv values + + align:start position:0% +in a reasonable way or my yv values + + + align:start position:0% +in a reasonable way or my yv values +would go from this line here up to this + + align:start position:0% +would go from this line here up to this + + + align:start position:0% +would go from this line here up to this +line here could be complicated so what + + align:start position:0% +line here could be complicated so what + + + align:start position:0% +line here could be complicated so what +we've really done is we've simplified + + align:start position:0% +we've really done is we've simplified + + + align:start position:0% +we've really done is we've simplified +the region that's the the easiest thing + + align:start position:0% +the region that's the the easiest thing + + + align:start position:0% +the region that's the the easiest thing +I mean + + align:start position:0% + + + + align:start position:0% + +sorry we also simplified the function + + align:start position:0% +sorry we also simplified the function + + + align:start position:0% +sorry we also simplified the function +but we've we've really simplified the + + align:start position:0% +but we've we've really simplified the + + + align:start position:0% +but we've we've really simplified the +region we're integrating over and so we + + align:start position:0% +region we're integrating over and so we + + + align:start position:0% +region we're integrating over and so we +only have one is a one is a function and + + align:start position:0% +only have one is a one is a function and + + + align:start position:0% +only have one is a one is a function and +one is a constant and that's quite nice + + align:start position:0% +one is a constant and that's quite nice + + + align:start position:0% +one is a constant and that's quite nice +to have on the inside so I think that's + + align:start position:0% +to have on the inside so I think that's + + + align:start position:0% +to have on the inside so I think that's +where I'll stop \ No newline at end of file diff --git a/lU_QT5GSuxI.txt b/lU_QT5GSuxI.txt new file mode 100644 index 0000000000000000000000000000000000000000..f671eee479feedb29ab5e80d9d33c366fe557cdf --- /dev/null +++ b/lU_QT5GSuxI.txt @@ -0,0 +1,1035 @@ +align:start position:0% + +our method for estimating sums can also + + align:start position:0% +our method for estimating sums can also + + + align:start position:0% +our method for estimating sums can also +be used to estimate products basically + + align:start position:0% +be used to estimate products basically + + + align:start position:0% +be used to estimate products basically +by taking logs to turn a product into a + + align:start position:0% +by taking logs to turn a product into a + + + align:start position:0% +by taking logs to turn a product into a +sum and we're going to use that to come + + align:start position:0% +sum and we're going to use that to come + + + align:start position:0% +sum and we're going to use that to come +up with another important estimate of a + + align:start position:0% +up with another important estimate of a + + + align:start position:0% +up with another important estimate of a +quantity that will come up really very + + align:start position:0% +quantity that will come up really very + + + align:start position:0% +quantity that will come up really very +regularly called n factorial so n + + align:start position:0% +regularly called n factorial so n + + + align:start position:0% +regularly called n factorial so n +factorial is the product of the first n + + align:start position:0% +factorial is the product of the first n + + + align:start position:0% +factorial is the product of the first n +integers 1 times 2 of little n minus 1 + + align:start position:0% +integers 1 times 2 of little n minus 1 + + + align:start position:0% +integers 1 times 2 of little n minus 1 +times n and concise product notation + + align:start position:0% +times n and concise product notation + + + align:start position:0% +times n and concise product notation +it's the product that's PI capital ply + + align:start position:0% +it's the product that's PI capital ply + + + align:start position:0% +it's the product that's PI capital ply +for product from I equals 1 to N of I + + align:start position:0% +for product from I equals 1 to N of I + + + align:start position:0% +for product from I equals 1 to N of I +and it's standard abbreviation is to + + align:start position:0% +and it's standard abbreviation is to + + + align:start position:0% +and it's standard abbreviation is to +write it as n bank pronounced n + + align:start position:0% +write it as n bank pronounced n + + + align:start position:0% +write it as n bank pronounced n +factorial so what I'd like to do is get + + align:start position:0% +factorial so what I'd like to do is get + + + align:start position:0% +factorial so what I'd like to do is get +an asymptotic estimate for n factorial + + align:start position:0% +an asymptotic estimate for n factorial + + + align:start position:0% +an asymptotic estimate for n factorial +again n factorial is one of these + + align:start position:0% +again n factorial is one of these + + + align:start position:0% +again n factorial is one of these +quantities where there isn't any exact + + align:start position:0% +quantities where there isn't any exact + + + align:start position:0% +quantities where there isn't any exact +formula that doesn't have those ellipses + + align:start position:0% +formula that doesn't have those ellipses + + + align:start position:0% +formula that doesn't have those ellipses +in it there's no short formula with + + align:start position:0% +in it there's no short formula with + + + align:start position:0% +in it there's no short formula with +basic operations fixed size up formula + + align:start position:0% +basic operations fixed size up formula + + + align:start position:0% +basic operations fixed size up formula +that expresses n factorial but we get a + + align:start position:0% +that expresses n factorial but we get a + + + align:start position:0% +that expresses n factorial but we get a +nice formula for a tight asymptotic + + align:start position:0% +nice formula for a tight asymptotic + + + align:start position:0% +nice formula for a tight asymptotic +estimate so as I said the first trick is + + align:start position:0% +estimate so as I said the first trick is + + + align:start position:0% +estimate so as I said the first trick is +to turn the product into a sum by taking + + align:start position:0% +to turn the product into a sum by taking + + + align:start position:0% +to turn the product into a sum by taking +logs so log of n factorial is the log of + + align:start position:0% +logs so log of n factorial is the log of + + + align:start position:0% +logs so log of n factorial is the log of +1 the product of 1 through n but a log + + align:start position:0% +1 the product of 1 through n but a log + + + align:start position:0% +1 the product of 1 through n but a log +of a product is the sum of the logs so + + align:start position:0% +of a product is the sum of the logs so + + + align:start position:0% +of a product is the sum of the logs so +it's simply log of 1 plus log of 2 up + + align:start position:0% +it's simply log of 1 plus log of 2 up + + + align:start position:0% +it's simply log of 1 plus log of 2 up +through log of n and expressed in some + + align:start position:0% +through log of n and expressed in some + + + align:start position:0% +through log of n and expressed in some +notation it's the sum from I equals 1 to + + align:start position:0% +notation it's the sum from I equals 1 to + + + align:start position:0% +notation it's the sum from I equals 1 to +N of log of log of a my now the integral + + align:start position:0% +N of log of log of a my now the integral + + + align:start position:0% +N of log of log of a my now the integral +method gives us a way to estimate this + + align:start position:0% +method gives us a way to estimate this + + + align:start position:0% +method gives us a way to estimate this +sum by bracketing it between the values + + align:start position:0% +sum by bracketing it between the values + + + align:start position:0% +sum by bracketing it between the values +of some integrals namely restating the + + align:start position:0% +of some integrals namely restating the + + + align:start position:0% +of some integrals namely restating the +the integral method for some metaphor + + align:start position:0% +the integral method for some metaphor + + + align:start position:0% +the integral method for some metaphor +for bounding integrals by sums this time + + align:start position:0% +for bounding integrals by sums this time + + + align:start position:0% +for bounding integrals by sums this time +we're looking at an increasing function + + align:start position:0% +we're looking at an increasing function + + + align:start position:0% +we're looking at an increasing function +because it's log of X let F be a weakly + + align:start position:0% +because it's log of X let F be a weakly + + + align:start position:0% +because it's log of X let F be a weakly +increasing function from positive reals + + align:start position:0% +increasing function from positive reals + + + align:start position:0% +increasing function from positive reals +to positive reals I'm interested in the + + align:start position:0% +to positive reals I'm interested in the + + + align:start position:0% +to positive reals I'm interested in the +sum from I equals 1 to N of F of I and I + + align:start position:0% +sum from I equals 1 to N of F of I and I + + + align:start position:0% +sum from I equals 1 to N of F of I and I +want to relate it and bound it by the + + align:start position:0% +want to relate it and bound it by the + + + align:start position:0% +want to relate it and bound it by the +integral from 0 from 1 to N of f of X + + align:start position:0% +integral from 0 from 1 to N of f of X + + + align:start position:0% +integral from 0 from 1 to N of f of X +where in this case the particular F that + + align:start position:0% +where in this case the particular F that + + + align:start position:0% +where in this case the particular F that +we're interested in is f of X is log X + + align:start position:0% +we're interested in is f of X is log X + + + align:start position:0% +we're interested in is f of X is log X +and the theorem says that with + + align:start position:0% +and the theorem says that with + + + align:start position:0% +and the theorem says that with +increasing functions S is bracketed + + align:start position:0% +increasing functions S is bracketed + + + align:start position:0% +increasing functions S is bracketed +between the integral plus the + + align:start position:0% +between the integral plus the + + + align:start position:0% +between the integral plus the +term in the sum and the integral plus + + align:start position:0% +term in the sum and the integral plus + + + align:start position:0% +term in the sum and the integral plus +the first term in the sum remember since + + align:start position:0% +the first term in the sum remember since + + + align:start position:0% +the first term in the sum remember since +the functions weakly increasing f of 1 + + align:start position:0% +the functions weakly increasing f of 1 + + + align:start position:0% +the functions weakly increasing f of 1 +is smaller than f of n so that's the way + + align:start position:0% +is smaller than f of n so that's the way + + + align:start position:0% +is smaller than f of n so that's the way +you remember which way the bounds go so + + align:start position:0% +you remember which way the bounds go so + + + align:start position:0% +you remember which way the bounds go so +s is between I plus F of 1 and I plus F + + align:start position:0% +s is between I plus F of 1 and I plus F + + + align:start position:0% +s is between I plus F of 1 and I plus F +of n by our general formula for applying + + align:start position:0% +of n by our general formula for applying + + + align:start position:0% +of n by our general formula for applying +integral balance to sums well what that + + align:start position:0% +integral balance to sums well what that + + + align:start position:0% +integral balance to sums well what that +tells us then is that the sum from 1 to + + align:start position:0% +tells us then is that the sum from 1 to + + + align:start position:0% +tells us then is that the sum from 1 to +N of log of I which is what we're + + align:start position:0% +N of log of I which is what we're + + + align:start position:0% +N of log of I which is what we're +interested in is bracketed between the + + align:start position:0% +interested in is bracketed between the + + + align:start position:0% +interested in is bracketed between the +integral from 1 to N of log X and the + + align:start position:0% +integral from 1 to N of log X and the + + + align:start position:0% +integral from 1 to N of log X and the +integral from 1 to N well it's plus log + + align:start position:0% +integral from 1 to N well it's plus log + + + align:start position:0% +integral from 1 to N well it's plus log +of 0 but a log of 1 rather but that's 0 + + align:start position:0% +of 0 but a log of 1 rather but that's 0 + + + align:start position:0% +of 0 but a log of 1 rather but that's 0 +and the integral from 1 to N of log of X + + align:start position:0% +and the integral from 1 to N of log of X + + + align:start position:0% +and the integral from 1 to N of log of X +plus the last term which is log of n ok + + align:start position:0% +plus the last term which is log of n ok + + + align:start position:0% +plus the last term which is log of n ok +in case you don't remember from first + + align:start position:0% +in case you don't remember from first + + + align:start position:0% +in case you don't remember from first +term calculus the integral from of log + + align:start position:0% +term calculus the integral from of log + + + align:start position:0% +term calculus the integral from of log +of X is in fact has the indefinite + + align:start position:0% +of X is in fact has the indefinite + + + align:start position:0% +of X is in fact has the indefinite +integral is X log of x over E which you + + align:start position:0% +integral is X log of x over E which you + + + align:start position:0% +integral is X log of x over E which you +can easily check by differentiating X + + align:start position:0% +can easily check by differentiating X + + + align:start position:0% +can easily check by differentiating X +log X over e ln means natural log + + align:start position:0% +log X over e ln means natural log + + + align:start position:0% +log X over e ln means natural log +remember in computer science l OG log + + align:start position:0% +remember in computer science l OG log + + + align:start position:0% +remember in computer science l OG log +means log to the base 2 unless you + + align:start position:0% +means log to the base 2 unless you + + + align:start position:0% +means log to the base 2 unless you +explicitly put some base on it like log + + align:start position:0% +explicitly put some base on it like log + + + align:start position:0% +explicitly put some base on it like log +L o G sub 10 so ellen is the natural log + + align:start position:0% +L o G sub 10 so ellen is the natural log + + + align:start position:0% +L o G sub 10 so ellen is the natural log +from calculus and plugging in this value + + align:start position:0% +from calculus and plugging in this value + + + align:start position:0% +from calculus and plugging in this value +for the indefinite integral of log of X + + align:start position:0% +for the indefinite integral of log of X + + + align:start position:0% +for the indefinite integral of log of X +and using the bounds 1/n what we come up + + align:start position:0% +and using the bounds 1/n what we come up + + + align:start position:0% +and using the bounds 1/n what we come up +with is that the sum of the logs is + + align:start position:0% +with is that the sum of the logs is + + + align:start position:0% +with is that the sum of the logs is +bounded between n Times log and over E + + align:start position:0% +bounded between n Times log and over E + + + align:start position:0% +bounded between n Times log and over E +and n Times log and over e plus log of n + + align:start position:0% +and n Times log and over e plus log of n + + + align:start position:0% +and n Times log and over e plus log of n +it's a pretty tight bounds what that + + align:start position:0% +it's a pretty tight bounds what that + + + align:start position:0% +it's a pretty tight bounds what that +means is that informally speaking the + + align:start position:0% +means is that informally speaking the + + + align:start position:0% +means is that informally speaking the +sum of the logs is about this term Plus + + align:start position:0% +sum of the logs is about this term Plus + + + align:start position:0% +sum of the logs is about this term Plus +that term Plus let's take the average + + align:start position:0% +that term Plus let's take the average + + + align:start position:0% +that term Plus let's take the average +value of that term which is half this + + align:start position:0% +value of that term which is half this + + + align:start position:0% +value of that term which is half this +term so we could say that the sum of the + + align:start position:0% +term so we could say that the sum of the + + + align:start position:0% +term so we could say that the sum of the +logs is approximately equal that's a + + align:start position:0% +logs is approximately equal that's a + + + align:start position:0% +logs is approximately equal that's a +little vague but live with it n log n + + align:start position:0% +little vague but live with it n log n + + + align:start position:0% +little vague but live with it n log n +over e plus a lot half of log n well now + + align:start position:0% +over e plus a lot half of log n well now + + + align:start position:0% +over e plus a lot half of log n well now +if I'm interest to remember in an + + align:start position:0% +if I'm interest to remember in an + + + align:start position:0% +if I'm interest to remember in an +estimate for n factorial so let's + + align:start position:0% +estimate for n factorial so let's + + + align:start position:0% +estimate for n factorial so let's +exponentiate both sides so taking eita + + align:start position:0% +exponentiate both sides so taking eita + + + align:start position:0% +exponentiate both sides so taking eita +this sum gives me a product of e to the + + align:start position:0% +this sum gives me a product of e to the + + + align:start position:0% +this sum gives me a product of e to the +e to this times e to that well eat to + + align:start position:0% +e to this times e to that well eat to + + + align:start position:0% +e to this times e to that well eat to +this + + align:start position:0% +this + + + align:start position:0% +this +is really--it's e to the log of n over e + + align:start position:0% +is really--it's e to the log of n over e + + + align:start position:0% +is really--it's e to the log of n over e +to the nth power which means it's n over + + align:start position:0% +to the nth power which means it's n over + + + align:start position:0% +to the nth power which means it's n over +e to the N and this is e to the log of n + + align:start position:0% +e to the N and this is e to the log of n + + + align:start position:0% +e to the N and this is e to the log of n +to the power half or square root of n so + + align:start position:0% +to the power half or square root of n so + + + align:start position:0% +to the power half or square root of n so +we wind up with n factorial is + + align:start position:0% +we wind up with n factorial is + + + align:start position:0% +we wind up with n factorial is +approximately equal to the square root + + align:start position:0% +approximately equal to the square root + + + align:start position:0% +approximately equal to the square root +of n times n over e to the N now this + + align:start position:0% +of n times n over e to the N now this + + + align:start position:0% +of n times n over e to the N now this +approximately equal is imprecise it's + + align:start position:0% +approximately equal is imprecise it's + + + align:start position:0% +approximately equal is imprecise it's +not asymptotically equal because we were + + align:start position:0% +not asymptotically equal because we were + + + align:start position:0% +not asymptotically equal because we were +doing an arithmetic average of zero and + + align:start position:0% +doing an arithmetic average of zero and + + + align:start position:0% +doing an arithmetic average of zero and +log n over two in addition it's very + + align:start position:0% +log n over two in addition it's very + + + align:start position:0% +log n over two in addition it's very +dangerous when you have two things that + + align:start position:0% +dangerous when you have two things that + + + align:start position:0% +dangerous when you have two things that +are approximately equal to exponentiate + + align:start position:0% +are approximately equal to exponentiate + + + align:start position:0% +are approximately equal to exponentiate +them and expect that they're still + + align:start position:0% +them and expect that they're still + + + align:start position:0% +them and expect that they're still +approximately equal often they aren't + + align:start position:0% +approximately equal often they aren't + + + align:start position:0% +approximately equal often they aren't +but nevertheless this is a kind of a + + align:start position:0% +but nevertheless this is a kind of a + + + align:start position:0% +but nevertheless this is a kind of a +heuristic derivation of some kind of + + align:start position:0% +heuristic derivation of some kind of + + + align:start position:0% +heuristic derivation of some kind of +asymptotic estimate that we would expect + + align:start position:0% +asymptotic estimate that we would expect + + + align:start position:0% +asymptotic estimate that we would expect +that n factorial was roughly like the + + align:start position:0% +that n factorial was roughly like the + + + align:start position:0% +that n factorial was roughly like the +square root of n times n over e to the + + align:start position:0% +square root of n times n over e to the + + + align:start position:0% +square root of n times n over e to the +enth power and it turns out that it's + + align:start position:0% +enth power and it turns out that it's + + + align:start position:0% +enth power and it turns out that it's +that this heuristic gives a pretty + + align:start position:0% +that this heuristic gives a pretty + + + align:start position:0% +that this heuristic gives a pretty +accurate answer a precise approximation + + align:start position:0% +accurate answer a precise approximation + + + align:start position:0% +accurate answer a precise approximation +is that n factorial is actually + + align:start position:0% +is that n factorial is actually + + + align:start position:0% +is that n factorial is actually +asymptotically equal to the square root + + align:start position:0% +asymptotically equal to the square root + + + align:start position:0% +asymptotically equal to the square root +of 2 pi n times n over e to the end and + + align:start position:0% +of 2 pi n times n over e to the end and + + + align:start position:0% +of 2 pi n times n over e to the end and +we're not going to prove that it + + align:start position:0% +we're not going to prove that it + + + align:start position:0% +we're not going to prove that it +requires elementary calculus but more + + align:start position:0% +requires elementary calculus but more + + + align:start position:0% +requires elementary calculus but more +than we want to take time for and this + + align:start position:0% +than we want to take time for and this + + + align:start position:0% +than we want to take time for and this +crucial formula though that we will be + + align:start position:0% +crucial formula though that we will be + + + align:start position:0% +crucial formula though that we will be +using very regularly to estimate the + + align:start position:0% +using very regularly to estimate the + + + align:start position:0% +using very regularly to estimate the +size of n factorial is called Sterling's + + align:start position:0% +size of n factorial is called Sterling's + + + align:start position:0% +size of n factorial is called Sterling's +formula and it's one to have on your + + align:start position:0% +formula and it's one to have on your + + + align:start position:0% +formula and it's one to have on your +crib sheets if you haven't memorized it \ No newline at end of file diff --git a/mnkTn0Y6GsU.txt b/mnkTn0Y6GsU.txt new file mode 100644 index 0000000000000000000000000000000000000000..febcd9320991dc7ed9e54419f39018f10a977954 --- /dev/null +++ b/mnkTn0Y6GsU.txt @@ -0,0 +1,3055 @@ +PROFESSOR: So OK, what +did we do last time? + +Thanks for coming +back by the way. + +So last time, we +did MDS codes. + +MDS codes, and we +looked at this. + +And we derived some generic +properties of these things if + +they existed. + +And then eventually, we moved +to Reed-Solomon codes. + +And so indeed, they exist. + +We talked a little bit about +existence altogether, the main + +conjection, MDS codes, +I just wrote it down. + +And like I said, you +want to be rich and + +famous, solve this. + +There's people doing geometry +in math that would be + +deliriously happy if +you solved it. + +So if for nothing else. + +So the last thing I wrote down +last time was something about + +a matrix which somebody +recognized as some Fourier + +transform matrix. + +And that's where I want to pick +up here, at least quickly + +make that connection. + +So let me rewrite the definition +of Reed-Solomon + +codes again. + +And so a Reed-Solomon code, +the way we defined it last + +time was all field elements, +we would evaluate the + +polynomial in all +field elements. + +Now we do it slightly +different. + +Let me make it Solomon-Stein +in order to denote that + +difference. + +And let's say this is +beta 0, beta n. + +So that's the old definition. + +Only the, let's say, the beta 0, +beta 1, up to beta n, they + +are the non-zero elements now. + +And just for the heck of it, so +we talked about punctured + +Reed-Solomon codes last +time that it would + +still be MDS codes. + +So nothing has changed there. + +In particular, all the arguments +would be the same. + +In particular, just to humor me, +let's say beta i is omega + +to the i, where omega +is primitive in Fq. + +So what that means, you remember +that primitive means + +that the powers of omega +cycle through all + +the non-zero elements. + +Remember the non-zero elements +are a multiplicative group. + +And it's a cyclic group. + +And it's the generator +of the group. + +Good. + +So once we write it like this, +we can actually write down the + +whole Reed-Solomon code in some +sort of transfer domain + +description in the Fourier +transform. + +And the way this goes +is the following. + +So from now on, I will make +implicit identification + +without making them. + +So this is an identification +which I + +just jump around between. + +A vector -- + +so this one would be a Fqn. + +And Fx would be maybe +0 to MDS 1. + +Let's leave it at that. + +So I make this -- + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: Yeah, let's make +this identification free. + +It's just a vector of length n +and a polynomial of length n. + +And so whenever I want this +to have a low degree, the + +polynomial, then I just +write that expression. + +So this identification +we make freely now. + +And then how can we write F? + +Let F now be code word in +the Reed-Solomon code. + +And then I say Fi. + +What is Fi? + +The i is element. + +Well, we know that this is +F of omega to the i. + +So this is, at the moment, +counted from 0. + +So this is -- + +you write it out -- + +Fj omega to the i to the +j, which is omega i j. + +And now, at this point in time, + +everybody recognizes this. + +This would be the discrete +Fourier transform of a vector. + +This is an element of order n. + +Usually, there's e to +the j and then an + +element of order n. + +Now it's in the finite field. + +But what's the difference? + +This would be the Fourier +transform. + +So a code word would be the +Fourier transform of a vector + +F. Let's just make sure it also +goes the other direction. + +So I claim that Fl would be -- +so what would be the Fourier + +transform if it, indeed, is +the Fourier transform? + +It is a minus, and then +it goes n minus 1 + +Fj omega minus jl. + +So the question is +is that true? + +Because that would +be the inverse. + +Is that true? + +Well, let's do what we do with +proofs of this type. + +I need that space here. + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: Sorry? + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: Yeah. + +So let's do what we do with +proofs of this type. + +That means we write it out. + +That's another beautiful thing +about finite fields. + +You never have to worry +about convergence. + +So for the F, we just +plug that in here. + +Sum, this would be -- + +what do we call it -- + +Fi omega to the ij. + +So this would be Fj. + +And then I want omega +minus jl. + +So is that true? + +Is the identity now true? + +Well, we see two sums. + +What do we do with two sums? + +If we're compelled to exchange +the order, that's + +always what we do. + +So Fi goes out. + +And then you get +omega to the -- + +what do we do -- + +i minus l times j. + +We have this. + +And so what is this? + +How can we work this out? + +Well, you know how to +express the sum. + +So this part of the sum is +really just omega i minus l to + +the n minus 1 minus 1. + +Well, that's a standard +formula for summing + +these things up. + +But omega is an element +of order n. + +Omega was an element +of order n. + +That's how we chose it. + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: It's what? + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: You multiplied +omega -- + +it's primitive in the +field, so omega -- + +we have omega da-da-da-da-da i +unequal to 1 for all i less + +than n and omega n +is equal to 1. + +So OK. + +That's fine. + +So it's an element of order n. + +That means the n-th power. + +We can interchange this. + +So this is 1 to the some +power remains 1. + +So 1 minus 1 is 0. + +The denominator -- + +well, actually, we get +two results here. + +If i is unequal to l, +then this is 0. + +If i is equal to l, then this +was just the sum of n once. + +So we get n here. + +i equal to 0. + +But n was q minus 1, the number +of non-zero field + +elements because it was +primitive in the field. + +And this one is just minus +1 in the field. + +Because q, we compute q is the +power of the prime of p. + +So that would be 0. + +If we just come out +as minus 1, that + +explains this minus here. + +And we can get rid of +the question mark. + +Look correct? + +All right. + +According to popular +vote, it is. + +So what do we really +have here? + +We have everything we want +from a Fourier transform. + +We have a Fourier +transform pair. + +We have a vector f, which we can +think of as being in the + +frequency domain. + +Then we have a vector F, +which is a Fourier + +transform of that. + +This one would be in the code +if the degree of this + +polynomial here would +be less than k. + +So now how can we understand +Reed-Solomon codes now from an + +engineering point of view? + +Classical -- + +what about band-limited +functions? + +What do we know about +band-limited functions? + +Because in a sense, the degree +less than k, this means that + +Fi is 0 for all i +greater than k. + +That's what it means. + +So in a sense, it's nothing but +a band-limited function if + +this is a frequency domain, +if you consider this as a + +frequency domain. + +So what do we know about the +band-limited function? + +Well, if a function +is band limited, + +it cannot be impulsive. + +We know that. + +It's a part of the frequency, +and the frequency domain is + +inversely relational to the +support of the function. + +So the whole idea of +Reed-Solomon codes, in a + +sense, can actually be +understood, at least + +intuitively, from Fourier +transform and the duality + +between time and frequency. + +Yeah. + +AUDIENCE: Was q a +prime number? + +PROFESSOR: q is not prime. +q is a power of a prime. + +q to the n. + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: There always is. + +Oh, sorry. + +AUDIENCE: [INAUDIBLE] + +or because for any q, there +would be always a primitive? + +PROFESSOR: Why there's always +a primitive element + +in the field -- + +yeah, sorry. + +I thought you had gone +through that. + +It's because the non-zero +elements in a field always + +make up a multiplicative +group. + +And it's always a cyclic +multiplicative group. + +So it's a cyclic multiplicative +group. + +And it's just the generator +of that group. + +AUDIENCE: [INAUDIBLE] +it was a -- + +PROFESSOR: It's the same +statement as saying, a cyclic + +group has a generator. + +AUDIENCE: If Fq, for example, +was a z, zq, + +then q has to be prime. + +PROFESSOR: Yeah. + +Yeah, in order for it to be a +field, q has to be prime. + +Right. + +That's true. + +That's true. + +But we are not worried +about -- + +There's also a beautiful theory +[UNINTELLIGIBLE PHRASE] + +rings if this would not be a +prime, very nice theory, + +becomes a little bit +more technical. + +You see, more technical, +then more difficult. + +I just wanted to give you this +correspondence on the Fourier + +transform because it's, from an +engineering point of view, + +a very nice insight. + +One of the reasons one can +understand that Reed-Solomon + +codes have a good minimum +distance is because it has a + +transform of a band-limited +function. + +So that's what I wanted +to say about the + +Fourier transforms here. + +I do not want to spend +too much time. + +I have to get through +decoding here. + +Since we have now this Fourier +transform correspondence, we + +can do another thing. + +We can, namely, say, well, F is +in the code if and only if + +the Fourier transform -- + +so that was the back +transform here. + +Also now, the code word, we can +interpret the code word as + +a polynomial. + +And the inverse transform +is just evaluating + +it at an omega again. + +F is in the code if and only the +transform of a code word + +is 0 for all i greater than +k up to n minus 1. + +Yeah. + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: So it basically +just means the support. + +If this one is band limited, +then this one cannot have + +arbitrarily small support. + +That's what it means. + +That's really all +I wanted to say. + +i greater than k and +less than n. + +So we have that F is in the +code if and only the + +polynomial evaluates to 0 +at a bunch of points. + +Now that leads to something +interesting. + +Because now we can say, well, +so what if we've just + +construct our set of vectors F +so that they evaluate to 0 + +somewhere where we want +them to zero. + +We construct them somewhat +differently than here. + +And in particular, let's define +g as a product of i + +equal k up to n minus 1 of +x minus omega minus i. + +So it's a polynomial. + +This is a polynomial which +satisfies this. + +So in particular, we have g of +omega minus i is equal to 0 + +for all i less than +n less than -- + +I'm sorry -- + +and greater than k. + +So this is a code word, right? + +We are agreed this +is a code word? + +Good. + +So we found a code word without +going through this + +here, without going through +the evaluation map. + +We found it straight away. + +But not only did we find this. + +This has degree n minus k. + +This has degree n minus k. + +So maybe there's another +interpretation. + +Now we can give a whole new +definition of the Reed-Solomon + +code, namely, as a set of +polynomials, which are sort of + +implicitly identified with a set +of vectors such that times + +this g of x and h of x +is less then k again. + +So what we have here, it's +again, you take a vector space + +of functions the h. + +It's a k dimensional +vector space. + +And we multiplied with this g. + +It's again a linear map, this +multiplication with a fixed + +polynomial. + +A linear map of this vector +space gives us, again, a + +vector space of dimension k. + +And all elements in this vector +space evaluate to 0 for + +all omega to the minus i. + +That's just the same +again, just the + +Reed-Solomon code again. + +So it's a very nice +complementary description to + +the same Reed-Solomon code we +could define up here, we have + +found again down here. + +What is so nice about this? + +Yeah, what do you think +is so nice about this? + +About this description? + +So now you have to think +as engineers. + +AUDIENCE: You can still +evaluate it. + +There, we have to evaluate it +at end points of function. + +PROFESSOR: Yeah, exactly. + +This is so easy to implement. + +So now we think a little +bit about encoder. + +An encoder for a Reed-Solomon +code. + +How would we do that? + +You look at this here. + +Hey, let's do this. + +Let's exactly do this. + +Meaning in VLSI, we do +something like -- + +and here, you would write +-- and this is + +just a delay element. + +This one would be g n minus k. + +This one -- + +so these would be the +coefficients. + +This polynomial, we can evaluate +once and for all. + +We do that once before we +start our communication. + +We evaluate that polynomial +once and for all. + +We know these coefficients. + +So these are multipliers which +multiply with those + +corresponding coefficients. + +And we feed into here the +coefficients of this + +polynomial. + +This is our information symbols, +which we simply feed + +into this circuitry. + +And into this circuit, out +comes F, out comes the + +coefficient. + +Polynomial multiplication. + +If you show that to a +VLSI designer, they + +are deliriously happy. + +They say, you know what? + +I implement you this thing. + +I implement you in 5,000 gates, +which is close to + +nothing nowadays. + +Maybe not. + +Maybe 10,000. + +And there you get to the +second reason that + +Reed-Solomon codes +are so extremely + +important in practice. + +On the one hand, they are MDS +codes, meaning they are about + +as good as it gets. + +And on the other hand, +they are algorithms. + +They are circuitry for these +things whose cost is close to + +nothing at least today. + +When they were invented, that +was quite different. + +In the '60s, that would have +not been implementable with + +transistors on a board or +something like that. + +But today, the cost is +close to nothing. + +So the whole algorithmic +treatment of Reed-Solomon + +codes is very well developed. + +The encoder you could +do like this. + +Yeah. + +AUDIENCE: Question about why +do you still require that + +degree [INAUDIBLE]? + +PROFESSOR: You don't +need to do that. + +But then the mapping is not +one-to-one anymore. + +Then the mapping is not +one-to-one anymore. + +Let's put it other ways. + +You want code words +of length n. + +If the degree is larger, +you run over. + +In order to still get a code +word, then you have to take it + +modular x to the n minus 1. + +And that would fold the +coefficients back. + +And still, it gives you a valid +code word then, but this + +is not one-to-one anymore. + +Anyway, the short answer is if +you allow more, then they + +become longer than n. + +So what's the time? + +OK. + +So this is a nice encoder. + +There even is a nicer encoder, +which I just want to give the + +formula for. + +The one reason that people still +have a problem with this + +is it's not systematic. + +People like to see the symbols +in the code words themselves. + +They want the systematic part. + +How could we achieve that? + +Well, we go from the same +description here. + +We say, well, let +h of x be given. + +Then compute x to the n minus k +times h of x modular g of x. + +So we divide this polynomial +by this polynomial g -- + +it has a name. + +It's called the generator +polynomial. + +We divide it by g. + +And out comes some polynomial +r of x of some low degree, + +degree less than g. + +And degree r of x less than +n minus k in particular. + +So and then we can +form a code word. + +I claim F of x, no, F is -- + +and here we write r, and +here we write h. + +The coefficient vector +of h and the + +coefficient vector of r. + +Why is that a code word? + +Why is that a code word? + +Maybe minus here. + +I'm always thinking +characteristic 2 anyway. + +So why is this a code word? + +Anybody, it's clear? + +What this is in terms of F of +x is r of x plus h of x. + +Oh, minus r of x. + +That's because we wrote +it like this. + +If we now take the F of x +modular g of x, well, this + +part has degree low. + +It's not affected by this +modular operation. + +This would be minus r of x plus +this one, modular g of x, + +which is r of x. + +So the whole thing is 0. + +If this is 0, that means g of +x is a factor of F. Hence, + +it's a code word. + +So we have a code word here. + +And in the code word, pop up +our symbols right away, our + +encoded information symbols +right away. + +So we get some nice systematic +encoding going. + +This division circuit by +g is pretty much the + +same size as this. + +It's not larger at all. + +So there, we get beautiful +algorithms. + +This is actually what's +implemented. + +If we go to any disc drive +[UNINTELLIGIBLE], that is + +usually what is implemented +in there, exactly this. + +Algorithms. + +Algorithmic treatment of +Reed-Solomon codes. + +Do you have any questions +about any of this? + +Yeah. + +AUDIENCE: I have a question +about do any these + +Reed-Solomon codes +map [INAUDIBLE]? + +PROFESSOR: They are +very costly map. + +Usually, it depends a lot +on the application. + +If you think disc drives, +[UNINTELLIGIBLE] as just being + +mapped, you take Reed-Solomon +codes over a characteristic 2. + +Then each field element is + +represented as a binary vector. + +And that binary vector is mapped +into on-off keying. + +Straight off the bat. + +Nothing more fancy. + +That is for disc drives. + +And as you do this, the +satellite standard, where it's + +mapped onto the 256-QAM field +elements [UNINTELLIGIBLE]. + +So it's many different ways. + +Many different ways. + +AUDIENCE: But to prove some +performance [UNINTELLIGIBLE] + +in the [UNINTELLIGIBLE], we need +to have mappings, right? + +PROFESSOR: In order to prove +performance mode, we need to + +have mappings. + +And the Hamming distance bounds +that we get from here + +give you bounds on the minimum +Euclidean distance. + +If these are good bounds or +not depends a lot on the + +modulation scheme. + +And to be perfectly honest, +they usually are not. + +They usually are not very +good, the bounds. + +But it's a very difficult +problem to design a code or to + +find a representation of the +fields that maps nicely onto a + +modulation scheme. + +Very difficult problem. + +AUDIENCE: How do we know +how to think that + +this is a good code? + +PROFESSOR: The code itself is +excellent in terms of MDS, the + +MDS property. + +AUDIENCE: But why does +MDS mean good codes? + +PROFESSOR: In respect +to modulation? + +AUDIENCE: Yes. + +PROFESSOR: It doesn't. + +It doesn't. + +It's a bit like this. + +It's really not easy to define +codes in Euclidean space. + +So all that we do is we find +ways to do that and guarantee + +some performance, some +sort of performance. + +It's not easy to spread out -- + +I don't know -- + +2 to the 1,000 points +in 1,500 dimensions. + +These would be typical +numbers really. + +It's not easy. + +And since that problem is +practically daunting, it's a + +daunting task, you have to +develop all sort of crutches + +to do that. + +And this is really one. + +So how to code MDS +codes playing a + +part in this mapping. + +If you want to be more fancy +about that, then you put a + +convolutional code or some other +code also in there and + +do a combine scheme. + +I think Professor Forney will +talk about that more. + +So here, it's just the +coding theoretic + +groundwork of these things. + +Anything else? + +Yeah. + +AUDIENCE: [INAUDIBLE] + +of the [INAUDIBLE] n minus 1. + +Close, very close [INAUDIBLE]. + +PROFESSOR: Yeah, thanks. + +So the algorithmic treatment +of Reed-Solomon codes is + +extremely elegant. + +And that's the second main +reason they are so much used. + +It doesn't cost so much +to implement them. + +Well, at least we've seen +that for the encoder. + +That's a fairly small circuit. + +So what about decoding? + +Decoding. + +How do we decode these things? + +How could we possibly +decode them? + +And I give you -- + +AUDIENCE: Fourier? + +PROFESSOR: Right, that's true. + +We could do the Fourier +transform. + +But it doesn't help us so much +because we receive something. + +And we receive a +vector, say, y. + +From now on, let's say +x is a code word. + +rs, right. + +So x, it's usually a code +word from now on. + +So this is a code word +plus an error. + +So in particular, if we take the +Fourier transform, we take + +the Fourier transform of the +code word, which is fine. + +But then we get the Fourier +transform of the error. + +So that destroys all the fun. + +What else could we do? + +Here's typical parameters +of a code. + +255, 239, 256. + +And you immediately see +that, OK, any sort of + +group force is out. + +How many code words +do we have here? + +We have 8 to the +239 code words. + +Now you don't want +to search that. + +You definitely don't want +to search that. + +So how could we possibly +decode these things? + +Turns out, to decode them in +some sort of optimal fashion, + +maximum likelihood [INAUDIBLE] + +actually, it's an +NP-hard problem. + +Maybe last year, actually, it +has been shown that it's an + +NP-hard problem to decode +Reed-Solomon codes. + +It was known that decoding +in general was NP-hard. + +But this is now the constraint +to Reed-Solomon + +codes is still hard. + +So what do we do? + +Yes, OK, what do we do? + +Let's say x is a code word. + +We know that. + +And set rate e, let's +just call it t. + +So what happens if you +don't have an error? + +Just thought experiment. + +Thought experiment, if you don't +have an error, then yi + +in all the positions is +equal to F of xi for + +some F of x of degree. + +In particular, since we +know the x's, we know + +the positions -- + +sorry, oh, sorry. + +That's not what I +wanted to write. + +This is definitely not what +I wanted to write. + +Let's keep that as c as a code +word and position i in c is + +associated with xi +in the fields. + +So meaning ci would +be F of xi. + +That's really what I +wanted to write. + +It makes more sense. + +So thought experiment. + +No errors. + +Then yi is F of xi for some F. +If they ran no errors, then we + +could just solve this linear +system of equations to find + +the coefficient of F. And the +coefficient of F, say, were + +our information circuits. + +Is it clear that this is a +linear system of equations? + +Yeah? + +You could write it out as +y0, y1, y2 equal to -- + +and here we have f0, +f1, up to fk-1. + +This is the linear system +of equations. + +We know the xi's. + +This is a linear system of +equation we have to solve. + +If there are no errors, +then life is easy. + +That seems to be reasonable. + +So what happens if we +do have errors? + +Somehow, we have to make sure +that the errors that we get do + +not cause any problem for us. + +And then we do something +very ingenious. + +We define something called an +error locator which is a + +polynomial x such +that x minus xi. + +So it's a polynomial which is +0 in all error positions. + +Well, you might say, we do not +know the error positions. + +Well, OK, that's true. + +Basically, this is, in the end, +what we want to find, + +this polynomial. + +But nonetheless, this +polynomial exists. + +We can cast, actually, +the coding problem -- + +this is form 1 s. + +Yes, what? + +AUDIENCE: [INAUDIBLE PHRASE]. + +PROFESSOR: Yeah, it's an +additive error model. + +But you can cast pretty +much anything in the + +[UNINTELLIGIBLE]. + +If a position is altered, you +can always model that as if + +something was added to it. + +Decoding problem one is find +lambda of x of minimal degree + +such that lambda of xi, +is 0 for all xi and + +degree f less than k. + +So I claim if you solve this +problem, namely, this is a + +problem I give you. + +I give you vector y. + +I give you vector y. + +Here it is. + +Here is vector y. + +And I give you vector x which +corresponds to the field + +elements where you evaluated +that in order to + +get the code word. + +And then I said, given y and x, +find two polynomials lambda + +and f such that f has maximum +degree k and lambda has + +minimum degree, the smaller +degree possible so + +that this is true. + +And I claim this solves +the decoding problem. + +This would solve the decoding +problem because once we have + +found this, then we +can take lambda to + +be the error locator. + +And we can basically read +off the information + +symbols from the f. + +So this decoding formulation now +brings it, at least, into + +the algebraic ground, brings +the whole decoding problem, + +makes it something +algebraically. + +But now the question becomes, +is that easy? + +Or can we do this? + +This problem here. + +Do you see any hope for +solving this problem? + +I guess the only +answer that -- + +OK, anybody says no? + +Anybody does not see any hope? + +All right. + +This is great. + +You all see hope here. + +You all see hope here, which +seems to make you an + +opportunistic bunch. + +Not opportunistic. + +What's the word? + +Optimistic. + +Optimistic bunch. + +Let's put it like this. + +What is the problem +in solving this? + +It's not linear. + +You get the coefficients +of lambda. + +Multiply the coefficients +of f. + +That whole thing becomes a +nonlinear problem, where we + +say in the end, find the +solution to a set of + +polynomial equations in a field, +which is a multivariate + +polynomial equations, where the +coefficients of lambda and + +f are the variables. + +You can do that. + +You could use techniques like +Grobner basis or so, and you + +could do that. + +But this is very difficult. + +This is computationally +tedious. + +So is that clear why this is +nonlinear, and why this is + +hard to solve a nonlinear +problem here? + +If not, then you have to say +something now, or forever hold + +your peace. + +So what do we do with +hard problems? + +Once you take the optimization +classes, there's almost like a + +reflex, there is a relax time. + +We find the proper relaxation +of the problem. + +Now the proper relaxation of +this problem is the following. + +Decoding problem two. + +Find lambda of x of minimal +degree such that -- + +it's almost the same, +almost the same -- + +lambda fi yi minus h of xi is +0, where the degree of h is + +less than k plus +degree lambda. + +So all that we did from this +formulation, which would give + +us a clean solution to the whole +thing, right now, we + +multiply in this lambda which +gives here, it keeps the + +lambda times y. + +And here, we get a new +polynomial, lambda times f, + +which now has degree at most +k plus degree lambda. + +And then we say, let's instead +solve this problem. + +Let's solve this problem. + +In particular, the question now +becomes well, we do not + +require this anymore. + +In this relaxed formulation, +we do not require this. + +And that makes all +the difference. + +It makes a world of difference +because this one -- + +look at it -- it's +a linear problem. + +It's a linear program. + +Why is it a linear problem? + +Do you see it's a +linear problem? + +Could you write down the +equation, the matrix equation? + +It's pretty straight, right? + +It's pretty straight. + +You could, for example, +write it like, here, a + +diagonal matrix yn. + +Here, you would get something. + +I think that seems +to be all right. + +And here, just the evaluation +of the h. + +So up to hk plus +degree lambda. + +That's a linear system +of equations. + +We can certainly solve this. + +Well, we do not know really +what the lambda is, what + +degree the lambda has. + +But we're just hypothesizing on +all the possible degrees. + +Well, we could say, OK, let's +assume the degree lambda is 0. + +It's a constant, which would +be the same as saying there + +are no errors. + +Then we can look at the +system of equations. + +Does it have a solution? + +Well, yes, no. + +If no, then we say, all right, +let's assume it's 1. + +Well, does it have a solution? + +Yes, no. + +And so on. + +Then we can move on. + +So we can solve this +relaxed problem. + +Does that help us? + +It's nice to solve a +relaxed problem. + +And in the end, we get two +vectors out of it, two + +polynomials, lambda and h. + +Does it really help us? + +Well, yes. + +Why? + +Because -- + +let's put it like this. + +We could easily check +if this is true. + +Once we have our h, we can +easily check if this is true. + +And if it is true, then we +have solved this problem. + +If it is true, we have solved +this problem, which is the + +problem we wanted to solve. + +Good. + +So is that all we need +to know about this? + +We want to give guarantees. + +We want to give guarantees that +we correct up to so many + +errors, t errors, right? + +So we have to guarantee that if +there are not more than t + +errors, whatever t will turn +out to be, we can guarantee + +that A, we will find +a solution, and + +B, this will hold. + +So two things to prove. + +Is that clear? + +That we have to prove +those two things? + +So the first one first. + +When do we find a solution? + +And are we guaranteed +to find it? + +Can we guarantee the existence +of a solution? + +Well, when can we do that? + +Let's look at this. + +These are n constraints. + +This is a system of linear +equations with n constraints. + +If the total number of degrees +of freedom exceeds n, then we + +are left with something +non-trivial after we solve the + +system of equations. + +So what's the total number +of degrees of freedom? + +The number of degrees +of freedom -- + +so we get the lambda as a degree +of freedom, so which is + +degree lambda plus 1. + +And the other one is plus -- + +what is this one -- + +plus k plus degree lambda. + +This is the total number of +degrees of freedom here. + +And the reason is that this +one should be minus 1. + +Sorry. + +So this is total number +of degrees of freedom. + +If this is greater than n, +then we can guarantee the + +existence of a solution, +a nontrivial solution. + +Then this thing will +have a solution. + +It's a homogeneous system +of equations. + +So the 0 is always a solution. + +But that's not much +good to us. + +So what do we get here? + +Degree lambda. + +To a degree lambda greater +than n minus k plus minus + +1 or n minus k. + +So the degree lambda greater +than n minus k over 2 -- does + +that remind you of +anything here? + +So this one is d +minus 1 over 2. + +So very interesting, right? + +Once upon a time, you learned +that if you make less than d/2 + +errors, you can correct that. + +Very nice. + +It pops up here. + +It pops up here out +of the blue. + +The reason that it pops up here +is, of course, the same + +statement, that as long as we +stay within d/2 errors, we are + +guaranteed to be able +to decode this. + +So this is one. + +So we know this one was +the number of errors. + +If t is greater or equal +than this, then -- + +let's forget about the t. + +If you proceed in this algorithm +hypothesizing the + +degrees of lambda, once we've +reached this number in the + +degree, there will +be a solution. + +And we don't have to go +further than that. + +So that's the first one. + +So the second thing we have +to prove is that -- + +I shouldn't have done this -- + +that for some t -- + +Yeah? + +AUDIENCE: [INAUDIBLE] + +standard degree of freedom +or less constraints? + +PROFESSOR: You want to +guarantee a solution. + +If you have more constraints +than degrees of freedom, then, + +since it's homogeneous, you +usually would be stuck with a + +zero solution. + +Everything's 0, which +is no good to us. + +It solves this problem, but +it doesn't give us any + +information. + +Is that all right? + +AUDIENCE: Why does it have to be +the condition that degrees + +of freedom has to be greater +than the constraints? + +PROFESSOR: No, no, the +degrees of freedom -- + +well, OK, it's true. + +We could get lucky. + +We could have redundancy in +this system of equations. + +And if we get lucky, that's +just for the better. + +And actually, you can show that +you do get lucky if very + +few errors happen. + +Then this would have low rank. + +You can show that. + +But short of knowing much, +we want to guarantee -- + +I just want, at this point in +time, to guarantee that there + +is a solution. + +There is a non-zero solution to +this system of equations, + +and the degree of lambda +is not more than d + +minus 1 over 2. + +There is a solution with a +degree of lambda being upper + +bounded by this. + +AUDIENCE: So [INAUDIBLE] + +less constraints? + +PROFESSOR: Yeah, no, no. + +Once this is satisfied, +I guarantee + +you there is a solution. + +That means, the smallest +solution is guaranteed not to + +be larger than that. + +But there are, of course, many, + +many more larger solutions. + +There are many solutions of +larger degree here, which we + +are not interested in since +we are interested + +in the minimal degree. + +So this is an upper bound on +the minimal degree lambda. + +So now the other one. + +So now we want to make the +statement about this one here. + +When can we guarantee that our +relaxation didn't matter? + +Despite our relaxation, our +solution that we find that in + +the solution that we find +lambda divides h. + +How can we guarantee this? + +So how can we guarantee this? + +How can we guarantee this? + +Let's look at lambda xi +yi minus h of xi. + +And we know this is +0 for all xi. + +We know that. + +We know that this guy here can +actually be written as ci plus + +ei minus h of xi. + +This is just expanding +this guy. + +We also know that we can write +lambda xi times ci alone minus + +f of xi lambda xi. + +This is 0. + +We know that this is true too. + +AUDIENCE: For some f. + +PROFESSOR: For some f. + +The text is to f, so that +this is true too. + +Then let's just subtract +these two guys. + +Let's just subtract these +two things here. + +And then we know that lambda +xi times ei -- + +so the first two cancel -- + +minus h of xi minus So we +know this is true too. + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: Yeah, sorry. + +Just in time. + +So what can we learn +from this? + +So what is the degree of this? + +What is the degree of this? + +Well, this guy here -- + +we'll write it somewhere +else -- + +well, this guy had degree h was +less than n minus k plus + +degree lambda less than +k plus degree lambda. + +That's because we set up +that problem that way. + +And we know that this +guy degree lambda. + +We know that. + +So this whole thing, let's call +it S. We know it's 0 for + +degree S less than +degree lambda. + +So why does that help us? + +Well, let's look +at the vector. + +Now let's look at all +the positions. + +Let's look at the vector where +we had, in the vector, we have + +lambda xi ei. + +And now the fundamental +question. + +What is the rate +of this vector? + +At most? + +What's the rate of +this guy at most? + +It's 12 seconds, +[UNINTELLIGIBLE]? + +Well, the rate of +this vector -- + +it's definitely not more than +the rate of the error. + +Because every time the error +is 0, the rate drops out. + +That's at most t. + +What is the rate +of this vector? + +So here we have a vector on +the other side, S of xi, a + +vector on the other side. + +What's the rate of this guy? + +That's just the polynomial of +degree at most k plus degree + +lambda minus 1. + +So we have that the rate of this +vector is n minus k plus + +degree lambda minus 1 plus +1 because of the minus. + +AUDIENCE: Greater than +or equal to? + +PROFESSOR: It's greater +than or equal, sorry. + +Otherwise, I would have been in +trouble in a second here. + +Yeah, so what does that mean? + +So actually, this one is nice +to rewrite is equal to d n + +minus t plus 1 d -- + +I really should have done it +like this in order not to -- + +it's d minus degree lambda. + +So what can we learn +from that? + +So we know this is true +for all the positions. + +So if this is true for all +positions, then -- + +so if d minus degree lambda -- + +actually, this is t because +the rate was defined. + +t was the number of errors. + +And the error locator was just +defined to have degree t. + +Right? + +The error locator was just x +minus xi over all positions + +where we had an error, so there + +are t of those positions. + +The degree of lambda +is equal to t. + +So now we take this. + +If d minus t is greater than +t, so if the rate of this + +vector is greater than the rate +of this vector, then we + +have a problem because +that cannot be. + +Of course, by this identity, +the rate of these + +two vectors is equal. + +So what is the way out? + +What's the way out? + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: Yeah. + +So if this is true, then S of +xi I claim has to be 0 and + +lambda of xi times ei has +to be 0 too for all i. + +That's the only way +out of this. + +Because, obviously, +this was allowed. + +If we really did find what we +wanted to find, namely, an + +error locator here, then +this vector -- + +we said it has to +be less than t. + +It can be less. + +In particular, it can +be 0 if this is, + +indeed, an error locator. + +And if our relaxation +didn't matter -- + +that means the h that we +find factors as that -- + +if the relaxation didn't matter, +then S would be 0 too. + +So that is a fair solution. + +That's a possibility. + +And if d minus t is greater than +t, then this proves this + +is the only solution +that is feasible. + +That's the only solution +you have. + +So what that means is if t +less than t/2, then the + +relaxation doesn't matter and h +of xi is equal to lambda of + +xi times f of xi. + +So is that clear? + +That's two very simple, yet +nice ways to prove things. + +Here, we guarantee +the solution. + +Here, we guarantee +the solution. + +Here, we guarantee that solution +is correct, namely, + +if not too many errors happen, +if less than t/2 errors + +happens, then relaxing the +original problem here to this + +other form, which we +could solve, does + +not change the solution. + +That's what's proved there. + +But about one-third +looks puzzled. + +About half looks puzzled, +I would think. + +Half looks puzzled. + +Is there any way I can +explain that better? + +Think. + +Let's just go through +the steps quickly. + +We had problem number one. + +Problem number one, which is a +nonlinear problem, but you see + +that if you could solve +this, you could solve + +the decoding problem. + +So you see that. + +Anybody who doesn't see that? + +All right. + +You're smart guys. + +If we can solve problem number +one, we are home free. + +We have solved the +decoding problem. + +Fine, we cannot solve it. + +It's a nonlinear problem. + +Well, we can solve it in +exponential time, but that's + +little fun. + +So we relax it. + +We relax it into problem +number two. + +All that we do, we multiply +things out. + +And we do not require, +once we solve the + +problem, this anymore. + +Now we have solved +this problem. + +We have solved this linear +system of equations. + +And after doing so, we have +found lambda and h. + +They are lying on the table +and looking at us. + +Now what? + +Are they any good? + +In particular, since a priori we +cannot guarantee that this + +relaxation didn't completely +destroy everything. + +We have solved the system. + +Now those two things are lying +on the table, looking at us, + +and asking, what am I? + +And in general, if there's an +arbitrary amount of errors + +happening near the channel, +actually, + +they do not mean much. + +They do not mean much. + +But now I claim that, well, if +not too many errors happened, + +but if the number of errors is +bounded to be this, less than + +half the minimum distance, then, +actually, I claim it did + +not matter if we solved +the relaxation or + +the original problem. + +And the argument is +roughly this. + +It goes like this. + +Here, we start. + +We have solved this. + +We have two polynomials lambda +and h, so that this is true + +for all xi. + +We know that we can write +it like this. + +That's just by definition +of yi, just + +expanding the yi into this. + +We know that this is true by +the definition of the code. + +The ci is the evaluation of +f, of some polynomial f. + +So we can write this just by +definition of the code. + +So once we have these two guys +here, we can subtract them + +[UNINTELLIGIBLE] here. + +So we know that we have solved +the following problem. + +We have found lambda and h. + +So that there is guaranteed to +exist the polynomial f, so + +that this whole thing, namely, +S of xi, that S is a + +polynomial of degree +at most -- + +what did we have -- + +k plus degree lambda minus 1. + +So that's a semi-hairy +step here. + +Is that clear that we can +guarantee the existence of a + +polynomial S of degree at most +k plus degree lambda minus 1? + +So that this equation holds. + +Once we have solved this, +we can guarantee the + +existence of this. + +That's what we're saying. + +We can guarantee the +existence of this. + +So now look at this. + +If you write this out for all +i's and put it in a vector, + +what's the rate of +this vector? + +Well, it's at most t because +all the other e's are 0. + +If lambda is an error +locator, it is 0. + +But we do not know that yet. + +All we know, it's at most t. + +This is on this side, so that +vector has a rate at most t. + +On this side, the rate of this +vector is at least this. + +Just by evaluating a polynomial +of this degree, + +this is the maximum number +of 0's we can get. + +So now we have two equalities, +this one and this one. + +But obviously, the two vectors +must be the same. + +So how can these two vectors be +the same and still satisfy + +these two inequalities? + +Good question. + +How can they be the same and +still satisfy this inequality? + +If t is less than d/2, then the +rate of this vector would + +have to be larger than +the rate of this. + +If they are non-zero. + +If they are non-zero, this would +have to be larger than + +this because then d minus t +would be greater than t. + +If this is true, this +implies this. + +If this is true, this implies +this which implies that the + +rate of this vector would be +larger than the rate of this + +vector if they are non-zero. + +But how can that be? + +Answer is cannot. + +Cannot be, hence, +they must be 0. + +Both vectors must be 0 +completely, which means this + +is an error locator. + +Because otherwise, this wouldn't +be 0, and this one -- + +where did I write it? + +Somewhere I wrote it. + +Where did I write it? + +Oh, here. + +So this S has to be 0 too. + +If this S is 0, then h of xi is +exactly this, means factors + +in the way you want it to. + +So that's all I can say. + +I could say it again, but it's +exactly the same words. + +And there's a limited benefit +to even the repetition code. + +So beautiful, right? + +We have brought down the entire +decoding problem for + +Reed-Solomon codes to solving a +linear system of equations, + +namely, this one here or this +one in short form, which, + +well, it's no problem at all in +the grand scheme of things. + +And that's the other thing that +makes Reed-Solomon codes + +so beautiful. + +They're access encoding, they're +access decoding, + +they're everything +that we want. + +Let me do one more thing about +the decoding just to bring it + +down a little bit, to talk a +little bit about complexity. + +Solving this linear system of +equations has been subject to + +research for 30 years, +40 years. + +So it started out with an +algorithm which essentially + +solved that linear +system directly. + +It was formulated a +bit different, but + +that's what it is. + +It's called the + +Peterson-Gorenstein-Zierler algorithm. + +They realized it was a +polynomial time decoding + +algorithm, a nice decoding +algorithm. + +Then Berlekamp -- + +I should write down the name. + +Berlekamp came up with a fast + +algorithm and square algorithm. + +Massey had his own formulation +of that algorithm, which was a + +bit more streamlined I think. + +Then there was a later version, +Berlekamp-Welch. + +The complexity of these +algorithms is all roughly the + +same, is all n squared roughly, + +which solved this here. + +And then there's +roughly nothing + +happening for 30 years. + +And after 30 years, then Madhu +Sudan made the next serious + +dent in the decoding history +of Reed-Solomon codes. + +So he found a way to solve this +problem even beyond half + +the minimum distance. + +And in hindsight, it's a very +nice and very simple trick + +that he used. + +So we started with +the following. + +We started that, well, if we +have no errors, then the pairs + +of points xi, yi lie +on this curve. + +That's another way to formulate +what we said that yi + +minus f of xi has to be 0. + +We said, well, if there are no +errors, all the points that we + +receive lie on this curve. + +Because there are errors, we +have to multiply this with an + +error locator and say this +is 0 for all xi, yi. + +So this was problem +number one. + +The relaxed form was lambda +xy minus h of x 0 xi, yi. + +That's the way we do it. + +So what did Madhu do? + +Very clever. + +He said, all that we have to do +is annihilate the effect of + +the error right in this. + +The whole reason for that lambda +was to annihilate -- + +so to take out the error +influence out of this + +interpolation formula, to allow +for a few errors to + +happen, which we can +put in lambda. + +Well, Madhu said, well, what +about we take a polynomial in + +two variables? + +A polynomial in two variables, +then same thing. + +If no errors happen, then all +the points xi, yi will lie on + +that curve. + +If a few errors happen, then +let's find a lambda xy, two + +variables of some minimal +degree, some very small degree + +so that this is still +satisfied. + +And the problem is entirely +the same. + +And this one, you cannot +solve either. + +You cannot solve either. + +But again, you can solve +the relaxation minus -- + +again, you can solve +the relaxation. + +This is, again, a linear +system of equations. + +And the coefficients of +lambda and psi now. + +Once you solve this linear +system of equations -- + +actually, this one you can more +handily write simply -- + +now there is no way to +distinguish the y anymore + +since both sides anyway +depend on y. + +Find a polynomial in two +variables such that this is 0 + +for all xi, yi. + +This is his central problem. + +This is his relaxation. + +Find a polynomial in two +variables, which he + +evaluates to 0. + +And then he has, essentially, +the same proofs we have here, + +a bit more technical, +but not much. + +I'm sure you can come up with +this if you sit down at home. + +Let's put it like this. + +There's no heavy machinery +in it. + +There's no heavy math in it. + +There's a lot of being clever +in it, but there's no heavy + +math in it. + +He can now guarantee that q of +xy, if t is less than n minus + +square root of 2k -- + +is that right -- + +2kn, then you can guarantee +that y minus fx is + +a factor q of xy. + +The same thing we wanted +to guarantee. + +And like I said, the proof is +very clever, but no heavy + +machinery in it. + +It's no heavy algebraic +geometry or any of + +this stuff in that. + +It's high school algebra. + +Well, freshman college +algebra. + +So that's what happens here. + +It took 30 years and a computer +scientist to solve + +that problem. + +That was not all I wanted +to say, but that's + +all I have time for. + +There's one minute left, so +there's no point in starting + +something now. + +Do you have any questions +about any of this? + +I should say that this 2 one can +get rid of, but that takes + +a little bit more machinery. + +The 2 one can get rid of, but +that's a bit more heavy. + +All right. + +So thanks so much. + +That's it. + +That's it. \ No newline at end of file diff --git a/nDuS5uQ7-lo.txt b/nDuS5uQ7-lo.txt new file mode 100644 index 0000000000000000000000000000000000000000..a0c44d3fc490e07ba6c7a9de1783bbe8f34d8a73 --- /dev/null +++ b/nDuS5uQ7-lo.txt @@ -0,0 +1,2315 @@ +align:start position:0% + +hi welcome back to recitation in lecture + + align:start position:0% +hi welcome back to recitation in lecture + + + align:start position:0% +hi welcome back to recitation in lecture +you've been learning about using the + + align:start position:0% +you've been learning about using the + + + align:start position:0% +you've been learning about using the +method of lrange multipliers to optimize + + align:start position:0% +method of lrange multipliers to optimize + + + align:start position:0% +method of lrange multipliers to optimize +functions of several variables given a + + align:start position:0% +functions of several variables given a + + + align:start position:0% +functions of several variables given a +constraint so here's a problem that you + + align:start position:0% +constraint so here's a problem that you + + + align:start position:0% +constraint so here's a problem that you +can use you can practice this method on + + align:start position:0% +can use you can practice this method on + + + align:start position:0% +can use you can practice this method on +so I've got a function f of XYZ = x^2 + + + align:start position:0% +so I've got a function f of XYZ = x^2 + + + + align:start position:0% +so I've got a function f of XYZ = x^2 + +x + 2 y^2 + 3 z^ 2 and what I'd like you + + align:start position:0% +x + 2 y^2 + 3 z^ 2 and what I'd like you + + + align:start position:0% +x + 2 y^2 + 3 z^ 2 and what I'd like you +to do is find the maximum and minimum + + align:start position:0% +to do is find the maximum and minimum + + + align:start position:0% +to do is find the maximum and minimum +values this function takes as the point + + align:start position:0% +values this function takes as the point + + + align:start position:0% +values this function takes as the point +XYZ moves around the unit sphere x^2 + + + align:start position:0% +XYZ moves around the unit sphere x^2 + + + + align:start position:0% +XYZ moves around the unit sphere x^2 + +y^2 + z^2 = 1 so to optimize this + + align:start position:0% +y^2 + z^2 = 1 so to optimize this + + + align:start position:0% +y^2 + z^2 = 1 so to optimize this +function given the constraint x^2 + y^2 + + align:start position:0% +function given the constraint x^2 + y^2 + + + align:start position:0% +function given the constraint x^2 + y^2 ++ z^2 equal 1 so why don't you pause the + + align:start position:0% ++ z^2 equal 1 so why don't you pause the + + + align:start position:0% ++ z^2 equal 1 so why don't you pause the +video take some time to work that out + + align:start position:0% +video take some time to work that out + + + align:start position:0% +video take some time to work that out +come back and we can work it out + + align:start position:0% + + + + align:start position:0% + +together hopefully you had some luck + + align:start position:0% +together hopefully you had some luck + + + align:start position:0% +together hopefully you had some luck +working on this problem let's have a go + + align:start position:0% +working on this problem let's have a go + + + align:start position:0% +working on this problem let's have a go +at it so remember that the method of + + align:start position:0% +at it so remember that the method of + + + align:start position:0% +at it so remember that the method of +lrange multipliers in order to apply it + + align:start position:0% +lrange multipliers in order to apply it + + + align:start position:0% +lrange multipliers in order to apply it +what it says is that when you have a a + + align:start position:0% +what it says is that when you have a a + + + align:start position:0% +what it says is that when you have a a +function being being optimized on some + + align:start position:0% +function being being optimized on some + + + align:start position:0% +function being being optimized on some +constraint condition what you what you + + align:start position:0% +constraint condition what you what you + + + align:start position:0% +constraint condition what you what you +do to find the points where the function + + align:start position:0% +do to find the points where the function + + + align:start position:0% +do to find the points where the function +could be maximum or minimum is that that + + align:start position:0% +could be maximum or minimum is that that + + + align:start position:0% +could be maximum or minimum is that that +first you look for points where the + + align:start position:0% +first you look for points where the + + + align:start position:0% +first you look for points where the +gradient of your objective function is + + align:start position:0% +gradient of your objective function is + + + align:start position:0% +gradient of your objective function is +parallel to the gradient of your + + align:start position:0% +parallel to the gradient of your + + + align:start position:0% +parallel to the gradient of your +constraint function so what that means + + align:start position:0% +constraint function so what that means + + + align:start position:0% +constraint function so what that means +is you take the partial derivatives FX + + align:start position:0% +is you take the partial derivatives FX + + + align:start position:0% +is you take the partial derivatives FX +FY FZ and you say FX has to be equal to + + align:start position:0% +FY FZ and you say FX has to be equal to + + + align:start position:0% +FY FZ and you say FX has to be equal to +Lambda * GX FY has to be equal to Lambda + + align:start position:0% +Lambda * GX FY has to be equal to Lambda + + + align:start position:0% +Lambda * GX FY has to be equal to Lambda +* gy and FZ has to be equal to Lambda * + + align:start position:0% +* gy and FZ has to be equal to Lambda * + + + align:start position:0% +* gy and FZ has to be equal to Lambda * +gz for some Lambda and then you solve + + align:start position:0% +gz for some Lambda and then you solve + + + align:start position:0% +gz for some Lambda and then you solve +that system together with the constraint + + align:start position:0% +that system together with the constraint + + + align:start position:0% +that system together with the constraint +equation and so the points that give you + + align:start position:0% +equation and so the points that give you + + + align:start position:0% +equation and so the points that give you +that that are the solutions of of that + + align:start position:0% +that that are the solutions of of that + + + align:start position:0% +that that are the solutions of of that +system of equations those points are + + align:start position:0% +system of equations those points are + + + align:start position:0% +system of equations those points are +your points that you have to check for + + align:start position:0% +your points that you have to check for + + + align:start position:0% +your points that you have to check for +whether they're the maximum or the + + align:start position:0% +whether they're the maximum or the + + + align:start position:0% +whether they're the maximum or the +minimum and also sometimes you have some + + align:start position:0% +minimum and also sometimes you have some + + + align:start position:0% +minimum and also sometimes you have some +some boundary to your region and you + + align:start position:0% +some boundary to your region and you + + + align:start position:0% +some boundary to your region and you +have to check that as well so in this + + align:start position:0% +have to check that as well so in this + + + align:start position:0% +have to check that as well so in this +case the sphere is doesn't have boundary + + align:start position:0% +case the sphere is doesn't have boundary + + + align:start position:0% +case the sphere is doesn't have boundary +right so so we don't have any boundary + + align:start position:0% +right so so we don't have any boundary + + + align:start position:0% +right so so we don't have any boundary +conditions to check so we're going to + + align:start position:0% +conditions to check so we're going to + + + align:start position:0% +conditions to check so we're going to +have a really straightforward problem to + + align:start position:0% +have a really straightforward problem to + + + align:start position:0% +have a really straightforward problem to +solve where we just have to look at the + + align:start position:0% +solve where we just have to look at the + + + align:start position:0% +solve where we just have to look at the +at the partial derivatives so let's + + align:start position:0% +at the partial derivatives so let's + + + align:start position:0% +at the partial derivatives so let's +write down that system of equations that + + align:start position:0% +write down that system of equations that + + + align:start position:0% +write down that system of equations that +we have to solve so the partial + + align:start position:0% +we have to solve so the partial + + + align:start position:0% +we have to solve so the partial +derivative of f with respect to X is + + align:start position:0% +derivative of f with respect to X is + + + align:start position:0% +derivative of f with respect to X is +going to be 2x + 1 so we have to solve + + align:start position:0% +going to be 2x + 1 so we have to solve + + + align:start position:0% +going to be 2x + 1 so we have to solve +the system 2x + 1 equals and the partial + + align:start position:0% +the system 2x + 1 equals and the partial + + + align:start position:0% +the system 2x + 1 equals and the partial +derivative of our constraint is with + + align:start position:0% +derivative of our constraint is with + + + align:start position:0% +derivative of our constraint is with +respect to X is 2x so this has to 2x + 1 + + align:start position:0% +respect to X is 2x so this has to 2x + 1 + + + align:start position:0% +respect to X is 2x so this has to 2x + 1 +has to equal Lambda * 2x that's what we + + align:start position:0% +has to equal Lambda * 2x that's what we + + + align:start position:0% +has to equal Lambda * 2x that's what we +get from the from the X partial + + align:start position:0% +get from the from the X partial + + + align:start position:0% +get from the from the X partial +derivatives how about from the Y partial + + align:start position:0% +derivatives how about from the Y partial + + + align:start position:0% +derivatives how about from the Y partial +derivatives the Y partial derivative of + + align:start position:0% +derivatives the Y partial derivative of + + + align:start position:0% +derivatives the Y partial derivative of +f is going to be 4 + + align:start position:0% +f is going to be 4 + + + align:start position:0% +f is going to be 4 +y so that has to be equal to Lambda and + + align:start position:0% +y so that has to be equal to Lambda and + + + align:start position:0% +y so that has to be equal to Lambda and +the Y partial derivative of the + + align:start position:0% +the Y partial derivative of the + + + align:start position:0% +the Y partial derivative of the +constraint equation is 2 + + align:start position:0% +constraint equation is 2 + + + align:start position:0% +constraint equation is 2 +Y and the Z partial derivative of f is 6 + + align:start position:0% + + + + align:start position:0% + +Z so 6z has to be equal to Lambda time + + align:start position:0% +Z so 6z has to be equal to Lambda time + + + align:start position:0% +Z so 6z has to be equal to Lambda time +well well the Z partial derivative of + + align:start position:0% +well well the Z partial derivative of + + + align:start position:0% +well well the Z partial derivative of +the constraint function is 2 Z Lambda * + + align:start position:0% +the constraint function is 2 Z Lambda * + + + align:start position:0% +the constraint function is 2 Z Lambda * +2 Z and we have the last equation x^2 + + + align:start position:0% +2 Z and we have the last equation x^2 + + + + align:start position:0% +2 Z and we have the last equation x^2 + +y^2 + z^2 = 1 so we get four equations + + align:start position:0% +y^2 + z^2 = 1 so we get four equations + + + align:start position:0% +y^2 + z^2 = 1 so we get four equations +in our variables X Y and Z plus this new + + align:start position:0% +in our variables X Y and Z plus this new + + + align:start position:0% +in our variables X Y and Z plus this new +parameter Lambda that we introduce and + + align:start position:0% +parameter Lambda that we introduce and + + + align:start position:0% +parameter Lambda that we introduce and +we want to solve these to find the + + align:start position:0% +we want to solve these to find the + + + align:start position:0% +we want to solve these to find the +points X Y and Z at which these + + align:start position:0% +points X Y and Z at which these + + + align:start position:0% +points X Y and Z at which these +equations are all satisfied and then + + align:start position:0% +equations are all satisfied and then + + + align:start position:0% +equations are all satisfied and then +once we get those points we have to test + + align:start position:0% +once we get those points we have to test + + + align:start position:0% +once we get those points we have to test +them to see whether they're the maximum + + align:start position:0% +them to see whether they're the maximum + + + align:start position:0% +them to see whether they're the maximum +or the minimum or neither um so so okay + + align:start position:0% +or the minimum or neither um so so okay + + + align:start position:0% +or the minimum or neither um so so okay +so we have this system of equations now + + align:start position:0% +so we have this system of equations now + + + align:start position:0% +so we have this system of equations now +this is a little bit complicated it's + + align:start position:0% +this is a little bit complicated it's + + + align:start position:0% +this is a little bit complicated it's +not a system of linear equations um so + + align:start position:0% +not a system of linear equations um so + + + align:start position:0% +not a system of linear equations um so +we need to think about ways that we can + + align:start position:0% +we need to think about ways that we can + + + align:start position:0% +we need to think about ways that we can +solve it and one thing that I think we + + align:start position:0% +solve it and one thing that I think we + + + align:start position:0% +solve it and one thing that I think we +can do here is if you look at the second + + align:start position:0% +can do here is if you look at the second + + + align:start position:0% +can do here is if you look at the second +and third equations you see that in the + + align:start position:0% +and third equations you see that in the + + + align:start position:0% +and third equations you see that in the +second equation everything has a factor + + align:start position:0% +second equation everything has a factor + + + align:start position:0% +second equation everything has a factor +of Y in it so either Y is equal to zero + + align:start position:0% +of Y in it so either Y is equal to zero + + + align:start position:0% +of Y in it so either Y is equal to zero +or we can divide by it so from the + + align:start position:0% +or we can divide by it so from the + + + align:start position:0% +or we can divide by it so from the +second equation + + align:start position:0% + + + + align:start position:0% + +we have that either Y is equal to zero + + align:start position:0% +we have that either Y is equal to zero + + + align:start position:0% +we have that either Y is equal to zero +or we can divide by + + align:start position:0% +or we can divide by + + + align:start position:0% +or we can divide by +Y in which case we get Lambda is equal + + align:start position:0% +Y in which case we get Lambda is equal + + + align:start position:0% +Y in which case we get Lambda is equal +to two similarly from the third equation + + align:start position:0% +to two similarly from the third equation + + + align:start position:0% +to two similarly from the third equation +we have that either Z is equal to zero + + align:start position:0% +we have that either Z is equal to zero + + + align:start position:0% +we have that either Z is equal to zero +or we can divide by Z and we get Lambda + + align:start position:0% +or we can divide by Z and we get Lambda + + + align:start position:0% +or we can divide by Z and we get Lambda +is equal to 3 so from the + + align:start position:0% +is equal to 3 so from the + + + align:start position:0% +is equal to 3 so from the +third equation we have Z equal 0 + + align:start position:0% +third equation we have Z equal 0 + + + align:start position:0% +third equation we have Z equal 0 +or Lambda equal 3 so now we have a bunch + + align:start position:0% +or Lambda equal 3 so now we have a bunch + + + align:start position:0% +or Lambda equal 3 so now we have a bunch +of possibilities right so either we have + + align:start position:0% +of possibilities right so either we have + + + align:start position:0% +of possibilities right so either we have +y = zal 0 or we have yal 0 and Lambda + + align:start position:0% +y = zal 0 or we have yal 0 and Lambda + + + align:start position:0% +y = zal 0 or we have yal 0 and Lambda +equal 3 or we have Lambda = 2 and zal 0 + + align:start position:0% +equal 3 or we have Lambda = 2 and zal 0 + + + align:start position:0% +equal 3 or we have Lambda = 2 and zal 0 +or well we the other possibility would + + align:start position:0% +or well we the other possibility would + + + align:start position:0% +or well we the other possibility would +be Lambda equal 2 and Lambda equals 3 + + align:start position:0% +be Lambda equal 2 and Lambda equals 3 + + + align:start position:0% +be Lambda equal 2 and Lambda equals 3 +but that can't happen so we have three + + align:start position:0% +but that can't happen so we have three + + + align:start position:0% +but that can't happen so we have three +possibilities three different ways that + + align:start position:0% +possibilities three different ways that + + + align:start position:0% +possibilities three different ways that +this could be satisfied so let's go over + + align:start position:0% +this could be satisfied so let's go over + + + align:start position:0% +this could be satisfied so let's go over +here and and write down what those U + + align:start position:0% +here and and write down what those U + + + align:start position:0% +here and and write down what those U +possibilities are so case one maybe I'll + + align:start position:0% +possibilities are so case one maybe I'll + + + align:start position:0% +possibilities are so case one maybe I'll +call it case a so the case a is when Y + + align:start position:0% +call it case a so the case a is when Y + + + align:start position:0% +call it case a so the case a is when Y +is equal to Z is equal to + + align:start position:0% +is equal to Z is equal to + + + align:start position:0% +is equal to Z is equal to +zero so when Y is equal to Z is equal 0 + + align:start position:0% +zero so when Y is equal to Z is equal 0 + + + align:start position:0% +zero so when Y is equal to Z is equal 0 +okay well we need to find X still so + + align:start position:0% +okay well we need to find X still so + + + align:start position:0% +okay well we need to find X still so +let's look back at our equations and + + align:start position:0% +let's look back at our equations and + + + align:start position:0% +let's look back at our equations and +when Y is equal to Z is equal to 0 well + + align:start position:0% +when Y is equal to Z is equal to 0 well + + + align:start position:0% +when Y is equal to Z is equal to 0 well +we can solve our constraint equation for + + align:start position:0% +we can solve our constraint equation for + + + align:start position:0% +we can solve our constraint equation for +x when y = zal 0 we have the x^2 = 1 so + + align:start position:0% +x when y = zal 0 we have the x^2 = 1 so + + + align:start position:0% +x when y = zal 0 we have the x^2 = 1 so +there are two possibilities the point uh + + align:start position:0% +there are two possibilities the point uh + + + align:start position:0% +there are two possibilities the point uh +1 0 0 and the point minus one 0 0 so + + align:start position:0% +1 0 0 and the point minus one 0 0 so + + + align:start position:0% +1 0 0 and the point minus one 0 0 so +this gives us in this case we have x = 1 + + align:start position:0% +this gives us in this case we have x = 1 + + + align:start position:0% +this gives us in this case we have x = 1 +or x = + + align:start position:0% +or x = + + + align:start position:0% +or x = +-1 so that gives us the points 1 0 0 and + + align:start position:0% +-1 so that gives us the points 1 0 0 and + + + align:start position:0% +-1 so that gives us the points 1 0 0 and +Min - one 0 0 that we're going to have + + align:start position:0% +Min - one 0 0 that we're going to have + + + align:start position:0% +Min - one 0 0 that we're going to have +to check at the end all right so the + + align:start position:0% +to check at the end all right so the + + + align:start position:0% +to check at the end all right so the +second case is we could have y equal to + + align:start position:0% +second case is we could have y equal to + + + align:start position:0% +second case is we could have y equal to +Z and Lambda equal to 3 so in this case + + align:start position:0% +Z and Lambda equal to 3 so in this case + + + align:start position:0% +Z and Lambda equal to 3 so in this case +let's go back to our equations again so + + align:start position:0% +let's go back to our equations again so + + + align:start position:0% +let's go back to our equations again so +from y from Lambda equals 3 + + align:start position:0% +from y from Lambda equals 3 + + + align:start position:0% +from y from Lambda equals 3 +we have in our first equation that 2x + + + align:start position:0% +we have in our first equation that 2x + + + + align:start position:0% +we have in our first equation that 2x + +1 = 6X so 1 = 4X or X = one4 so this + + align:start position:0% +1 = 6X so 1 = 4X or X = one4 so this + + + align:start position:0% +1 = 6X so 1 = 4X or X = one4 so this +implies over here that x equal one4 and + + align:start position:0% +implies over here that x equal one4 and + + + align:start position:0% +implies over here that x equal one4 and +now let's we still need to find Z so if + + align:start position:0% +now let's we still need to find Z so if + + + align:start position:0% +now let's we still need to find Z so if +we go back to our uh our constraint + + align:start position:0% +we go back to our uh our constraint + + + align:start position:0% +we go back to our uh our constraint +equation here we have that X is a + + align:start position:0% +equation here we have that X is a + + + align:start position:0% +equation here we have that X is a +quarter and Y is Zer so that means 116 + + + align:start position:0% +quarter and Y is Zer so that means 116 + + + + align:start position:0% +quarter and Y is Zer so that means 116 + +z^2 = 1 so has to be the square root of + + align:start position:0% +z^2 = 1 so has to be the square root of + + + align:start position:0% +z^2 = 1 so has to be the square root of +1516 plus or minus um so and Z is equal + + align:start position:0% +1516 plus or minus um so and Z is equal + + + align:start position:0% +1516 plus or minus um so and Z is equal +to plus or minus so that we can also + + align:start position:0% +to plus or minus so that we can also + + + align:start position:0% +to plus or minus so that we can also +write that as the > 15 over 4 so this + + align:start position:0% +write that as the > 15 over 4 so this + + + align:start position:0% +write that as the > 15 over 4 so this +also gives us two points to check the + + align:start position:0% +also gives us two points to check the + + + align:start position:0% +also gives us two points to check the +points are + + align:start position:0% +points are + + + align:start position:0% +points are +one4 + + align:start position:0% +one4 + + + align:start position:0% +one4 +0 < TK 15 over 4 and + + align:start position:0% +0 < TK 15 over 4 and + + + align:start position:0% +0 < TK 15 over 4 and +one4 0 - > 15 over 4 and Fin finally we + + align:start position:0% +one4 0 - > 15 over 4 and Fin finally we + + + align:start position:0% +one4 0 - > 15 over 4 and Fin finally we +have our third case so our third case is + + align:start position:0% +have our third case so our third case is + + + align:start position:0% +have our third case so our third case is +when Lambda is equal to 2 and Z is equal + + align:start position:0% +when Lambda is equal to 2 and Z is equal + + + align:start position:0% +when Lambda is equal to 2 and Z is equal +to + + align:start position:0% +to + + + align:start position:0% +to +zero so again um let's go back over to + + align:start position:0% +zero so again um let's go back over to + + + align:start position:0% +zero so again um let's go back over to +our equation so when Lambda equals 2 in + + align:start position:0% +our equation so when Lambda equals 2 in + + + align:start position:0% +our equation so when Lambda equals 2 in +the first equation we have 2X + 1 = 4X + + align:start position:0% +the first equation we have 2X + 1 = 4X + + + align:start position:0% +the first equation we have 2X + 1 = 4X +so 2x = 1 or X is a half so this gives + + align:start position:0% +so 2x = 1 or X is a half so this gives + + + align:start position:0% +so 2x = 1 or X is a half so this gives +us + + align:start position:0% +us + + + align:start position:0% +us +xal a half and now if you take zal 0 and + + align:start position:0% +xal a half and now if you take zal 0 and + + + align:start position:0% +xal a half and now if you take zal 0 and +x = 1/2 we can take that down to to our + + align:start position:0% +x = 1/2 we can take that down to to our + + + align:start position:0% +x = 1/2 we can take that down to to our +constraint equation and we get A4 + y^2 + + align:start position:0% +constraint equation and we get A4 + y^2 + + + align:start position:0% +constraint equation and we get A4 + y^2 += 1 so Y is aare < TK of + + align:start position:0% += 1 so Y is aare < TK of + + + align:start position:0% += 1 so Y is aare < TK of +3/4 so y = plus orus < TK 3 / 2 and this + + align:start position:0% +3/4 so y = plus orus < TK 3 / 2 and this + + + align:start position:0% +3/4 so y = plus orus < TK 3 / 2 and this +gives us two + + align:start position:0% +gives us two + + + align:start position:0% +gives us two +points 12 < TK 3 over2 + + align:start position:0% +points 12 < TK 3 over2 + + + align:start position:0% +points 12 < TK 3 over2 +0 and 12 - > 3 over2 + + align:start position:0% +0 and 12 - > 3 over2 + + + align:start position:0% +0 and 12 - > 3 over2 +zero those were our three cases we've + + align:start position:0% +zero those were our three cases we've + + + align:start position:0% +zero those were our three cases we've +solved each of them we' solved each of + + align:start position:0% +solved each of them we' solved each of + + + align:start position:0% +solved each of them we' solved each of +them all the way down to finding the the + + align:start position:0% +them all the way down to finding the the + + + align:start position:0% +them all the way down to finding the the +points that they they lead to now + + align:start position:0% +points that they they lead to now + + + align:start position:0% +points that they they lead to now +remember we said already that there's no + + align:start position:0% +remember we said already that there's no + + + align:start position:0% +remember we said already that there's no +boundry to this region it's just the + + align:start position:0% +boundry to this region it's just the + + + align:start position:0% +boundry to this region it's just the +sphere has it has no edges um so so + + align:start position:0% +sphere has it has no edges um so so + + + align:start position:0% +sphere has it has no edges um so so +these are the only points we have to + + align:start position:0% +these are the only points we have to + + + align:start position:0% +these are the only points we have to +check we have to check these six points + + align:start position:0% +check we have to check these six points + + + align:start position:0% +check we have to check these six points +what do we have to check them for well + + align:start position:0% +what do we have to check them for well + + + align:start position:0% +what do we have to check them for well +we have to look at the value of F at + + align:start position:0% +we have to look at the value of F at + + + align:start position:0% +we have to look at the value of F at +each of these six points to and figure + + align:start position:0% +each of these six points to and figure + + + align:start position:0% +each of these six points to and figure +out we want to figure out where f is + + align:start position:0% +out we want to figure out where f is + + + align:start position:0% +out we want to figure out where f is +maximized and where f is minimized and + + align:start position:0% +maximized and where f is minimized and + + + align:start position:0% +maximized and where f is minimized and +these six points are the the only points + + align:start position:0% +these six points are the the only points + + + align:start position:0% +these six points are the the only points +where that could happen where F could be + + align:start position:0% +where that could happen where F could be + + + align:start position:0% +where that could happen where F could be +maximized or minimized so we just have + + align:start position:0% +maximized or minimized so we just have + + + align:start position:0% +maximized or minimized so we just have +to evaluate our our objective function f + + align:start position:0% +to evaluate our our objective function f + + + align:start position:0% +to evaluate our our objective function f +at these six points and find the largest + + align:start position:0% +at these six points and find the largest + + + align:start position:0% +at these six points and find the largest +value and the smallest value so let's do + + align:start position:0% +value and the smallest value so let's do + + + align:start position:0% +value and the smallest value so let's do +that so our objective function remember + + align:start position:0% +that so our objective function remember + + + align:start position:0% +that so our objective function remember +it's all the way back over here it's + + align:start position:0% +it's all the way back over here it's + + + align:start position:0% +it's all the way back over here it's +this function x^2 + x + 2 y^2 + 3 z^ + + align:start position:0% +this function x^2 + x + 2 y^2 + 3 z^ + + + align:start position:0% +this function x^2 + x + 2 y^2 + 3 z^ +2 Okay so let's let's look at the value + + align:start position:0% +2 Okay so let's let's look at the value + + + align:start position:0% +2 Okay so let's let's look at the value +of that function at these points so x^2 + + align:start position:0% +of that function at these points so x^2 + + + align:start position:0% +of that function at these points so x^2 ++ x + 2 y^2 + 3 z^ 2 at the point 1 0 + + align:start position:0% ++ x + 2 y^2 + 3 z^ 2 at the point 1 0 + + + align:start position:0% ++ x + 2 y^2 + 3 z^ 2 at the point 1 0 +that's just equal to 2 two so I'm just + + align:start position:0% +that's just equal to 2 two so I'm just + + + align:start position:0% +that's just equal to 2 two so I'm just +I'm going to write the function values + + align:start position:0% +I'm going to write the function values + + + align:start position:0% +I'm going to write the function values +just off to the side of the of the + + align:start position:0% +just off to the side of the of the + + + align:start position:0% +just off to the side of the of the +points here so so this gives me the + + align:start position:0% +points here so so this gives me the + + + align:start position:0% +points here so so this gives me the +value two and I'm going to and I'm going + + align:start position:0% +value two and I'm going to and I'm going + + + align:start position:0% +value two and I'm going to and I'm going +to circle them so the point 1 0 0 gives + + align:start position:0% +to circle them so the point 1 0 0 gives + + + align:start position:0% +to circle them so the point 1 0 0 gives +me the value two the point minus one 0 0 + + align:start position:0% +me the value two the point minus one 0 0 + + + align:start position:0% +me the value two the point minus one 0 0 +so that's x^2 is 1 + x is min - one so + + align:start position:0% +so that's x^2 is 1 + x is min - one so + + + align:start position:0% +so that's x^2 is 1 + x is min - one so +that's 1 - 1 is zero and then the Y and + + align:start position:0% +that's 1 - 1 is zero and then the Y and + + + align:start position:0% +that's 1 - 1 is zero and then the Y and +Z terms are both zero so at at the point + + align:start position:0% +Z terms are both zero so at at the point + + + align:start position:0% +Z terms are both zero so at at the point +minus one 0 0 the function value is zero + + align:start position:0% +minus one 0 0 the function value is zero + + + align:start position:0% +minus one 0 0 the function value is zero +I'm going to circle + + align:start position:0% +I'm going to circle + + + align:start position:0% +I'm going to circle +that oh boy okay so at these points at + + align:start position:0% +that oh boy okay so at these points at + + + align:start position:0% +that oh boy okay so at these points at +the point one + + align:start position:0% +the point one + + + align:start position:0% +the point one +qu0 > 15 over4 and 1 qu + + align:start position:0% +qu0 > 15 over4 and 1 qu + + + align:start position:0% +qu0 > 15 over4 and 1 qu +0us 15 over4 uh I'm going to cheat and + + align:start position:0% +0us 15 over4 uh I'm going to cheat and + + + align:start position:0% +0us 15 over4 uh I'm going to cheat and +look at what I wrote down already so you + + align:start position:0% +look at what I wrote down already so you + + + align:start position:0% +look at what I wrote down already so you +could do the arithmetic yourself um but + + align:start position:0% +could do the arithmetic yourself um but + + + align:start position:0% +could do the arithmetic yourself um but +I think it's not that hard to work out + + align:start position:0% +I think it's not that hard to work out + + + align:start position:0% +I think it's not that hard to work out +that in the in both of these cases the + + align:start position:0% +that in the in both of these cases the + + + align:start position:0% +that in the in both of these cases the +function value that you get out is 25 + + align:start position:0% +function value that you get out is 25 + + + align:start position:0% +function value that you get out is 25 +over 8 I'm not going to do the + + align:start position:0% +over 8 I'm not going to do the + + + align:start position:0% +over 8 I'm not going to do the +arithmetic uh right now I don't um so uh + + align:start position:0% +arithmetic uh right now I don't um so uh + + + align:start position:0% +arithmetic uh right now I don't um so uh +but you can you can double check that + + align:start position:0% +but you can you can double check that + + + align:start position:0% +but you can you can double check that +for yourself and at these last two + + align:start position:0% +for yourself and at these last two + + + align:start position:0% +for yourself and at these last two +points the points 12 < tk3 over2 0 and + + align:start position:0% +points the points 12 < tk3 over2 0 and + + + align:start position:0% +points the points 12 < tk3 over2 0 and +12 minus < tk3 over 2 0 um the and and + + align:start position:0% +12 minus < tk3 over 2 0 um the and and + + + align:start position:0% +12 minus < tk3 over 2 0 um the and and +this the the function has the same value + + align:start position:0% +this the the function has the same value + + + align:start position:0% +this the the function has the same value +of both those points that value is + + align:start position:0% + + + + align:start position:0% + +94s yeah so 25 or8 was the value at both + + align:start position:0% +94s yeah so 25 or8 was the value at both + + + align:start position:0% +94s yeah so 25 or8 was the value at both +of these points and 9/4 was the is the + + align:start position:0% +of these points and 9/4 was the is the + + + align:start position:0% +of these points and 9/4 was the is the +value of both of these points so now to + + align:start position:0% +value of both of these points so now to + + + align:start position:0% +value of both of these points so now to +Maxim to find the maximum value of the + + align:start position:0% +Maxim to find the maximum value of the + + + align:start position:0% +Maxim to find the maximum value of the +function and the minimum value of the + + align:start position:0% +function and the minimum value of the + + + align:start position:0% +function and the minimum value of the +function we just look at the values that + + align:start position:0% +function we just look at the values that + + + align:start position:0% +function we just look at the values that +we got and say which of these is biggest + + align:start position:0% +we got and say which of these is biggest + + + align:start position:0% +we got and say which of these is biggest +and which of these is smallest and in + + align:start position:0% +and which of these is smallest and in + + + align:start position:0% +and which of these is smallest and in +our case it's easy to see that zero is + + align:start position:0% +our case it's easy to see that zero is + + + align:start position:0% +our case it's easy to see that zero is +the + + align:start position:0% +the + + + align:start position:0% +the +minimum you know all all the other + + align:start position:0% +minimum you know all all the other + + + align:start position:0% +minimum you know all all the other +values are are positive so zero is the + + align:start position:0% +values are are positive so zero is the + + + align:start position:0% +values are are positive so zero is the +minimum so our minimum + + align:start position:0% +minimum so our minimum + + + align:start position:0% +minimum so our minimum +value the minimum value of f is + + align:start position:0% +value the minimum value of f is + + + align:start position:0% +value the minimum value of f is +zero at the point -1 0 0 and if you just + + align:start position:0% +zero at the point -1 0 0 and if you just + + + align:start position:0% +zero at the point -1 0 0 and if you just +compare the values two and 258 and 9/4 + + align:start position:0% +compare the values two and 258 and 9/4 + + + align:start position:0% +compare the values two and 258 and 9/4 +uh 258 is the is the largest this is + + align:start position:0% +uh 258 is the is the largest this is + + + align:start position:0% +uh 258 is the is the largest this is +bigger than three whereas both of those + + align:start position:0% +bigger than three whereas both of those + + + align:start position:0% +bigger than three whereas both of those +are less than three for example is one + + align:start position:0% +are less than three for example is one + + + align:start position:0% +are less than three for example is one +easy way to see that so the + + align:start position:0% + + + + align:start position:0% + +max of + + align:start position:0% +max of + + + align:start position:0% +max of +f is + + align:start position:0% +f is + + + align:start position:0% +f is +258 and that's achieved at the point + + align:start position:0% +258 and that's achieved at the point + + + align:start position:0% +258 and that's achieved at the point +one4 0 plus orus < TK 15 over + + align:start position:0% +one4 0 plus orus < TK 15 over + + + align:start position:0% +one4 0 plus orus < TK 15 over +4 so there you have it the method of + + align:start position:0% +4 so there you have it the method of + + + align:start position:0% +4 so there you have it the method of +lrange multipliers we just followed + + align:start position:0% +lrange multipliers we just followed + + + align:start position:0% +lrange multipliers we just followed +exactly the the the strategy that that + + align:start position:0% +exactly the the the strategy that that + + + align:start position:0% +exactly the the the strategy that that +that we have so you have you start out + + align:start position:0% +that we have so you have you start out + + + align:start position:0% +that we have so you have you start out +and you have an objective function and a + + align:start position:0% +and you have an objective function and a + + + align:start position:0% +and you have an objective function and a +and a constraint function and so what do + + align:start position:0% +and a constraint function and so what do + + + align:start position:0% +and a constraint function and so what do +you do you write down their partial + + align:start position:0% +you do you write down their partial + + + align:start position:0% +you do you write down their partial +derivatives and you come up with the + + align:start position:0% +derivatives and you come up with the + + + align:start position:0% +derivatives and you come up with the +system of equations so the system of + + align:start position:0% +system of equations so the system of + + + align:start position:0% +system of equations so the system of +equations that you get by setting you + + align:start position:0% +equations that you get by setting you + + + align:start position:0% +equations that you get by setting you +know FX equal Lambda GX FY equal Lambda + + align:start position:0% +know FX equal Lambda GX FY equal Lambda + + + align:start position:0% +know FX equal Lambda GX FY equal Lambda +gy FZ equals Lambda gz and your + + align:start position:0% +gy FZ equals Lambda gz and your + + + align:start position:0% +gy FZ equals Lambda gz and your +constraint equation g equals some + + align:start position:0% +constraint equation g equals some + + + align:start position:0% +constraint equation g equals some +constant + + align:start position:0% +constant + + + align:start position:0% +constant +so then the the one part of this + + align:start position:0% +so then the the one part of this + + + align:start position:0% +so then the the one part of this +procedure that isn't just a a recipe is + + align:start position:0% +procedure that isn't just a a recipe is + + + align:start position:0% +procedure that isn't just a a recipe is +that you need to solve this this system + + align:start position:0% +that you need to solve this this system + + + align:start position:0% +that you need to solve this this system +of equations and sometimes that can be + + align:start position:0% +of equations and sometimes that can be + + + align:start position:0% +of equations and sometimes that can be +hard so in this case there were some a + + align:start position:0% +hard so in this case there were some a + + + align:start position:0% +hard so in this case there were some a +couple of observations that we could + + align:start position:0% +couple of observations that we could + + + align:start position:0% +couple of observations that we could +make from the second and third equations + + align:start position:0% +make from the second and third equations + + + align:start position:0% +make from the second and third equations +that made it relatively straightforward + + align:start position:0% +that made it relatively straightforward + + + align:start position:0% +that made it relatively straightforward +to do um and that gave us some cases and + + align:start position:0% +to do um and that gave us some cases and + + + align:start position:0% +to do um and that gave us some cases and +then in each of those cases we were able + + align:start position:0% +then in each of those cases we were able + + + align:start position:0% +then in each of those cases we were able +to completely solve for the points x y + + align:start position:0% +to completely solve for the points x y + + + align:start position:0% +to completely solve for the points x y +and z now we also could solve for the + + align:start position:0% +and z now we also could solve for the + + + align:start position:0% +and z now we also could solve for the +associated values of Lambda but Lambda + + align:start position:0% +associated values of Lambda but Lambda + + + align:start position:0% +associated values of Lambda but Lambda +isn't important to us it doesn't it + + align:start position:0% +isn't important to us it doesn't it + + + align:start position:0% +isn't important to us it doesn't it +doesn't affect F it's it we can forget + + align:start position:0% +doesn't affect F it's it we can forget + + + align:start position:0% +doesn't affect F it's it we can forget +about it as soon as we' found it once + + align:start position:0% +about it as soon as we' found it once + + + align:start position:0% +about it as soon as we' found it once +we' once we found X Y and Z so we were + + align:start position:0% +we' once we found X Y and Z so we were + + + align:start position:0% +we' once we found X Y and Z so we were +able to solve in this case we got six + + align:start position:0% +able to solve in this case we got six + + + align:start position:0% +able to solve in this case we got six +points of interest and then you just + + align:start position:0% +points of interest and then you just + + + align:start position:0% +points of interest and then you just +look at the value of your objective + + align:start position:0% +look at the value of your objective + + + align:start position:0% +look at the value of your objective +function at those points so that was + + align:start position:0% +function at those points so that was + + + align:start position:0% +function at those points so that was +what I wrote down in these circles so + + align:start position:0% +what I wrote down in these circles so + + + align:start position:0% +what I wrote down in these circles so +you look at the at the value of the + + align:start position:0% +you look at the at the value of the + + + align:start position:0% +you look at the at the value of the +objective function and to find the + + align:start position:0% +objective function and to find the + + + align:start position:0% +objective function and to find the +maximum value of the function you just + + align:start position:0% +maximum value of the function you just + + + align:start position:0% +maximum value of the function you just +look at which of those is largest now + + align:start position:0% +look at which of those is largest now + + + align:start position:0% +look at which of those is largest now +sometimes not in this problem but in + + align:start position:0% +sometimes not in this problem but in + + + align:start position:0% +sometimes not in this problem but in +other problems you'll also have to check + + align:start position:0% +other problems you'll also have to check + + + align:start position:0% +other problems you'll also have to check +if if the region has a boundary you'll + + align:start position:0% +if if the region has a boundary you'll + + + align:start position:0% +if if the region has a boundary you'll +also have to check for possible Maxima + + align:start position:0% +also have to check for possible Maxima + + + align:start position:0% +also have to check for possible Maxima +and Minima on the boundary of the region + + align:start position:0% +and Minima on the boundary of the region + + + align:start position:0% +and Minima on the boundary of the region +but a sphere doesn't have any edges so + + align:start position:0% +but a sphere doesn't have any edges so + + + align:start position:0% +but a sphere doesn't have any edges so +it doesn't have any boundary so we don't + + align:start position:0% +it doesn't have any boundary so we don't + + + align:start position:0% +it doesn't have any boundary so we don't +have to worry about that so that's how + + align:start position:0% +have to worry about that so that's how + + + align:start position:0% +have to worry about that so that's how +we apply the method of lrange + + align:start position:0% +we apply the method of lrange + + + align:start position:0% +we apply the method of lrange +multipliers to this problem and and how + + align:start position:0% +multipliers to this problem and and how + + + align:start position:0% +multipliers to this problem and and how +you can apply it to other problems as + + align:start position:0% +you can apply it to other problems as + + + align:start position:0% +you can apply it to other problems as +well I'll end there \ No newline at end of file diff --git a/nyuKHTzr6xA.txt b/nyuKHTzr6xA.txt new file mode 100644 index 0000000000000000000000000000000000000000..db6dd16ffc3274c235a148644dc7aecc7b07a85b --- /dev/null +++ b/nyuKHTzr6xA.txt @@ -0,0 +1,675 @@ +align:start position:0% + +now let's talk briefly about + + align:start position:0% +now let's talk briefly about + + + align:start position:0% +now let's talk briefly about +different types of ventilation and + + align:start position:0% +different types of ventilation and + + + align:start position:0% +different types of ventilation and +different ways that they can mix or not + + align:start position:0% +different ways that they can mix or not + + + align:start position:0% +different ways that they can mix or not +mix a + + align:start position:0% +mix a + + + align:start position:0% +mix a +a room the air in a room so the first + + align:start position:0% +a room the air in a room so the first + + + align:start position:0% +a room the air in a room so the first +type which is what we've mainly been + + align:start position:0% +type which is what we've mainly been + + + align:start position:0% +type which is what we've mainly been +talking about is so-called mixing + + align:start position:0% +talking about is so-called mixing + + + align:start position:0% +talking about is so-called mixing +ventilation + + align:start position:0% +ventilation + + + align:start position:0% +ventilation +so this is when uh the cold colder air + + align:start position:0% +so this is when uh the cold colder air + + + align:start position:0% +so this is when uh the cold colder air +is forced from above or in other cases + + align:start position:0% +is forced from above or in other cases + + + align:start position:0% +is forced from above or in other cases +the warmer air is forced from below in + + align:start position:0% +the warmer air is forced from below in + + + align:start position:0% +the warmer air is forced from below in +such a way that there's an + + align:start position:0% +such a way that there's an + + + align:start position:0% +such a way that there's an +unstable thermal gradient so that the + + align:start position:0% +unstable thermal gradient so that the + + + align:start position:0% +unstable thermal gradient so that the +buoyancy + + align:start position:0% +buoyancy + + + align:start position:0% +buoyancy +forces end up contributing towards + + align:start position:0% +forces end up contributing towards + + + align:start position:0% +forces end up contributing towards +mixing + + align:start position:0% +mixing + + + align:start position:0% +mixing +and then you can see that if a person's + + align:start position:0% +and then you can see that if a person's + + + align:start position:0% +and then you can see that if a person's +in the room the natural thermal plume + + align:start position:0% +in the room the natural thermal plume + + + align:start position:0% +in the room the natural thermal plume +rising around + + align:start position:0% +rising around + + + align:start position:0% +rising around +that person of warmer air as well as the + + align:start position:0% +that person of warmer air as well as the + + + align:start position:0% +that person of warmer air as well as the +respiratory plume sketch turn yellow + + align:start position:0% +respiratory plume sketch turn yellow + + + align:start position:0% +respiratory plume sketch turn yellow +from all the breathing + + align:start position:0% +from all the breathing + + + align:start position:0% +from all the breathing +both of them are kind of rising and then + + align:start position:0% +both of them are kind of rising and then + + + align:start position:0% +both of them are kind of rising and then +well mixed in the room before + + align:start position:0% +well mixed in the room before + + + align:start position:0% +well mixed in the room before +they're finally removed by the outlet of + + align:start position:0% +they're finally removed by the outlet of + + + align:start position:0% +they're finally removed by the outlet of +the ventilation + + align:start position:0% +the ventilation + + + align:start position:0% +the ventilation +and so that is the situation we've been + + align:start position:0% +and so that is the situation we've been + + + align:start position:0% +and so that is the situation we've been +mainly talking about of the well-mixed + + align:start position:0% +mainly talking about of the well-mixed + + + align:start position:0% +mainly talking about of the well-mixed +room + + align:start position:0% +room + + + align:start position:0% +room +but it's worth considering that in some + + align:start position:0% +but it's worth considering that in some + + + align:start position:0% +but it's worth considering that in some +other cases the ventilation specifically + + align:start position:0% +other cases the ventilation specifically + + + align:start position:0% +other cases the ventilation specifically +is set up to + + align:start position:0% +is set up to + + + align:start position:0% +is set up to +reduce mixing so especially in rooms + + align:start position:0% +reduce mixing so especially in rooms + + + align:start position:0% +reduce mixing so especially in rooms +that have high + + align:start position:0% +that have high + + + align:start position:0% +that have high +ceilings it can be advantageous to set + + align:start position:0% +ceilings it can be advantageous to set + + + align:start position:0% +ceilings it can be advantageous to set +up a stratified ambient + + align:start position:0% +up a stratified ambient + + + align:start position:0% +up a stratified ambient +where the thermal plume from the body is + + align:start position:0% +where the thermal plume from the body is + + + align:start position:0% +where the thermal plume from the body is +rising + + align:start position:0% +rising + + + align:start position:0% +rising +as well as the respiratory plumes and + + align:start position:0% +as well as the respiratory plumes and + + + align:start position:0% +as well as the respiratory plumes and +are collecting + + align:start position:0% +are collecting + + + align:start position:0% +are collecting +in the upper uh area of the room uh + + align:start position:0% +in the upper uh area of the room uh + + + align:start position:0% +in the upper uh area of the room uh +where they're being uh + + align:start position:0% +where they're being uh + + + align:start position:0% +where they're being uh +gently sucked out as the colder air is + + align:start position:0% +gently sucked out as the colder air is + + + align:start position:0% +gently sucked out as the colder air is +being pumped in now from below so that's + + align:start position:0% +being pumped in now from below so that's + + + align:start position:0% +being pumped in now from below so that's +actually a stable + + align:start position:0% +actually a stable + + + align:start position:0% +actually a stable +thermal gradient uh and so at least the + + align:start position:0% +thermal gradient uh and so at least the + + + align:start position:0% +thermal gradient uh and so at least the +the buoyancy forces are not leading to + + align:start position:0% +the buoyancy forces are not leading to + + + align:start position:0% +the buoyancy forces are not leading to +any uh large-scale convection although + + align:start position:0% +any uh large-scale convection although + + + align:start position:0% +any uh large-scale convection although +there certainly are still boundary layer + + align:start position:0% +there certainly are still boundary layer + + + align:start position:0% +there certainly are still boundary layer +flows and plumes from the people + + align:start position:0% +flows and plumes from the people + + + align:start position:0% +flows and plumes from the people +and from their motion as i have + + align:start position:0% +and from their motion as i have + + + align:start position:0% +and from their motion as i have +described earlier + + align:start position:0% +described earlier + + + align:start position:0% +described earlier +one advantage here is that if a mask is + + align:start position:0% +one advantage here is that if a mask is + + + align:start position:0% +one advantage here is that if a mask is +worn + + align:start position:0% +worn + + + align:start position:0% +worn +then the uh respiratory droplets coming + + align:start position:0% +then the uh respiratory droplets coming + + + align:start position:0% +then the uh respiratory droplets coming +from breathing which are sketcher and + + align:start position:0% +from breathing which are sketcher and + + + align:start position:0% +from breathing which are sketcher and +yellow are kind of brought + + align:start position:0% +yellow are kind of brought + + + align:start position:0% +yellow are kind of brought +closer to the thermal plume and forced + + align:start position:0% +closer to the thermal plume and forced + + + align:start position:0% +closer to the thermal plume and forced +to rise more + + align:start position:0% +to rise more + + + align:start position:0% +to rise more +so it basically causes the uh little + + align:start position:0% +so it basically causes the uh little + + + align:start position:0% +so it basically causes the uh little +droplet let's see the infectious + + align:start position:0% +droplet let's see the infectious + + + align:start position:0% +droplet let's see the infectious +aerosols from the breath + + align:start position:0% +aerosols from the breath + + + align:start position:0% +aerosols from the breath +to be more likely swept to the upper + + align:start position:0% +to be more likely swept to the upper + + + align:start position:0% +to be more likely swept to the upper +reaches where they might sit + + align:start position:0% +reaches where they might sit + + + align:start position:0% +reaches where they might sit +at the higher levels of the room and + + align:start position:0% +at the higher levels of the room and + + + align:start position:0% +at the higher levels of the room and +then be sucked out so that can actually + + align:start position:0% +then be sucked out so that can actually + + + align:start position:0% +then be sucked out so that can actually +be a situation + + align:start position:0% +be a situation + + + align:start position:0% +be a situation +where a less well mixed room can be + + align:start position:0% +where a less well mixed room can be + + + align:start position:0% +where a less well mixed room can be +better on the other hand + + align:start position:0% +better on the other hand + + + align:start position:0% +better on the other hand +the advantage of a well-mixed room is + + align:start position:0% +the advantage of a well-mixed room is + + + align:start position:0% +the advantage of a well-mixed room is +that the pathogen in the droplets is + + align:start position:0% +that the pathogen in the droplets is + + + align:start position:0% +that the pathogen in the droplets is +diluted throughout a larger space and + + align:start position:0% +diluted throughout a larger space and + + + align:start position:0% +diluted throughout a larger space and +that can be + + align:start position:0% +that can be + + + align:start position:0% +that can be +more advantageous in any case this + + align:start position:0% +more advantageous in any case this + + + align:start position:0% +more advantageous in any case this +situation with having uh with high + + align:start position:0% +situation with having uh with high + + + align:start position:0% +situation with having uh with high +ceilings and especially with natural + + align:start position:0% +ceilings and especially with natural + + + align:start position:0% +ceilings and especially with natural +ventilation + + align:start position:0% +ventilation + + + align:start position:0% +ventilation +where you set up a stratified ambient is + + align:start position:0% +where you set up a stratified ambient is + + + align:start position:0% +where you set up a stratified ambient is +a strategy that's been used for a long + + align:start position:0% +a strategy that's been used for a long + + + align:start position:0% +a strategy that's been used for a long +time in fact florence nightingale in the + + align:start position:0% +time in fact florence nightingale in the + + + align:start position:0% +time in fact florence nightingale in the +1800s + + align:start position:0% +1800s + + + align:start position:0% +1800s +recommended that hospitals should have + + align:start position:0% +recommended that hospitals should have + + + align:start position:0% +recommended that hospitals should have +high ceilings and good ventilation + + align:start position:0% +high ceilings and good ventilation + + + align:start position:0% +high ceilings and good ventilation +for protection against airborne + + align:start position:0% + + + + align:start position:0% + +pathogens \ No newline at end of file diff --git a/p8918BiV01c.txt b/p8918BiV01c.txt new file mode 100644 index 0000000000000000000000000000000000000000..9d40d43a398014a562363092f6b5f7ccf27281bd --- /dev/null +++ b/p8918BiV01c.txt @@ -0,0 +1,6043 @@ +align:start position:0% + +I'm Sarah Hansen and today I'm talking + + align:start position:0% +I'm Sarah Hansen and today I'm talking + + + align:start position:0% +I'm Sarah Hansen and today I'm talking +with Anna Bell. She's a super smart + + align:start position:0% +with Anna Bell. She's a super smart + + + align:start position:0% +with Anna Bell. She's a super smart +programmer, author, and senior lecturer + + align:start position:0% +programmer, author, and senior lecturer + + + align:start position:0% +programmer, author, and senior lecturer +at MIT. Her computer science videos on + + align:start position:0% +at MIT. Her computer science videos on + + + align:start position:0% +at MIT. Her computer science videos on +our channel have captivated millions of + + align:start position:0% +our channel have captivated millions of + + + align:start position:0% +our channel have captivated millions of +learners around the world. Today, we + + align:start position:0% +learners around the world. Today, we + + + align:start position:0% +learners around the world. Today, we +talk about Python, growth mindset, and + + align:start position:0% +talk about Python, growth mindset, and + + + align:start position:0% +talk about Python, growth mindset, and +rubber ducks. I have to know what the + + align:start position:0% +rubber ducks. I have to know what the + + + align:start position:0% +rubber ducks. I have to know what the +ducks are now. Like, I I can't continue. + + align:start position:0% +ducks are now. Like, I I can't continue. + + + align:start position:0% +ducks are now. Like, I I can't continue. +Then I ask her, with the emergence of + + align:start position:0% +Then I ask her, with the emergence of + + + align:start position:0% +Then I ask her, with the emergence of +AI, do we even still need to learn how + + align:start position:0% +AI, do we even still need to learn how + + + align:start position:0% +AI, do we even still need to learn how +to code? What's the value proposition of + + align:start position:0% +to code? What's the value proposition of + + + align:start position:0% +to code? What's the value proposition of +learning a language like Python? Do we + + align:start position:0% +learning a language like Python? Do we + + + align:start position:0% +learning a language like Python? Do we +still need to do it? So, not sure if + + align:start position:0% +still need to do it? So, not sure if + + + align:start position:0% +still need to do it? So, not sure if +this exactly answers the question. Oh, + + align:start position:0% +this exactly answers the question. Oh, + + + align:start position:0% +this exactly answers the question. Oh, +tell me more. Find out her answer today + + align:start position:0% +tell me more. Find out her answer today + + + align:start position:0% +tell me more. Find out her answer today +on Chalk Radio. Hi, Anna. Hi. How are + + align:start position:0% +on Chalk Radio. Hi, Anna. Hi. How are + + + align:start position:0% +on Chalk Radio. Hi, Anna. Hi. How are +you? I'm good. You're here. I'm so + + align:start position:0% +you? I'm good. You're here. I'm so + + + align:start position:0% +you? I'm good. You're here. I'm so +excited. Yes, me, too. This is one of + + align:start position:0% +excited. Yes, me, too. This is one of + + + align:start position:0% +excited. Yes, me, too. This is one of +our pilot episodes for something new + + align:start position:0% +our pilot episodes for something new + + + align:start position:0% +our pilot episodes for something new +that we're trying, which is a video + + align:start position:0% +that we're trying, which is a video + + + align:start position:0% +that we're trying, which is a video +version of our Chalk Radio podcast. Many + + align:start position:0% +version of our Chalk Radio podcast. Many + + + align:start position:0% +version of our Chalk Radio podcast. Many +ways, it's an experiment. How do you + + align:start position:0% +ways, it's an experiment. How do you + + + align:start position:0% +ways, it's an experiment. How do you +feel about experiments? Are you an + + align:start position:0% +feel about experiments? Are you an + + + align:start position:0% +feel about experiments? Are you an +adventurous person? No, not at all. Oh, + + align:start position:0% +adventurous person? No, not at all. Oh, + + + align:start position:0% +adventurous person? No, not at all. Oh, +great. We're going to be great. Yeah, I + + align:start position:0% +great. We're going to be great. Yeah, I + + + align:start position:0% +great. We're going to be great. Yeah, I +like stability and I like boring days. + + align:start position:0% +like stability and I like boring days. + + + align:start position:0% +like stability and I like boring days. +Oh, well, I'm not sure we're going to + + align:start position:0% +Oh, well, I'm not sure we're going to + + + align:start position:0% +Oh, well, I'm not sure we're going to +have one of those with these with these + + align:start position:0% +have one of those with these with these + + + align:start position:0% +have one of those with these with these +ducks and so I I actually don't know + + align:start position:0% +ducks and so I I actually don't know + + + align:start position:0% +ducks and so I I actually don't know +what the ducks mean. Um, so I think + + align:start position:0% +what the ducks mean. Um, so I think + + + align:start position:0% +what the ducks mean. Um, so I think +you're going to tell me a little bit + + align:start position:0% +you're going to tell me a little bit + + + align:start position:0% +you're going to tell me a little bit +later, but as we Yeah, I think we're in + + align:start position:0% +later, but as we Yeah, I think we're in + + + align:start position:0% +later, but as we Yeah, I think we're in +for an adventure and a little bit maybe + + align:start position:0% +for an adventure and a little bit maybe + + + align:start position:0% +for an adventure and a little bit maybe +of a choose your own adventure. Mhm. So, + + align:start position:0% +of a choose your own adventure. Mhm. So, + + + align:start position:0% +of a choose your own adventure. Mhm. So, +you're at MIT, you've been here for + + align:start position:0% +you're at MIT, you've been here for + + + align:start position:0% +you're at MIT, you've been here for +about 10 years. Um, and you spend most + + align:start position:0% +about 10 years. Um, and you spend most + + + align:start position:0% +about 10 years. Um, and you spend most +of your time thinking about and teaching + + align:start position:0% +of your time thinking about and teaching + + + align:start position:0% +of your time thinking about and teaching +people who are new to programming, + + align:start position:0% +people who are new to programming, + + + align:start position:0% +people who are new to programming, +introducing them. And I'm wondering what + + align:start position:0% +introducing them. And I'm wondering what + + + align:start position:0% +introducing them. And I'm wondering what +that means to you, why you're interested + + align:start position:0% +that means to you, why you're interested + + + align:start position:0% +that means to you, why you're interested +in teaching in particular, like people + + align:start position:0% +in teaching in particular, like people + + + align:start position:0% +in teaching in particular, like people +like me. What do you get out of that? + + align:start position:0% +like me. What do you get out of that? + + + align:start position:0% +like me. What do you get out of that? +And tell me about that experience. Um, + + align:start position:0% +And tell me about that experience. Um, + + + align:start position:0% +And tell me about that experience. Um, +so I recognize that I well I don't want + + align:start position:0% +so I recognize that I well I don't want + + + align:start position:0% +so I recognize that I well I don't want +everyone to become a computer scientist, + + align:start position:0% +everyone to become a computer scientist, + + + align:start position:0% +everyone to become a computer scientist, +but I do think that everyone should + + align:start position:0% +but I do think that everyone should + + + align:start position:0% +but I do think that everyone should +learn programming as a skill. So + + align:start position:0% +learn programming as a skill. So + + + align:start position:0% +learn programming as a skill. So +programming is should become sort of + + align:start position:0% +programming is should become sort of + + + align:start position:0% +programming is should become sort of +like what math is now where you kind of + + align:start position:0% +like what math is now where you kind of + + + align:start position:0% +like what math is now where you kind of +learn it in um elementary school and you + + align:start position:0% +learn it in um elementary school and you + + + align:start position:0% +learn it in um elementary school and you +obviously use it here and there in your + + align:start position:0% +obviously use it here and there in your + + + align:start position:0% +obviously use it here and there in your +adult life. But I don't know, you know, + + align:start position:0% +adult life. But I don't know, you know, + + + align:start position:0% +adult life. But I don't know, you know, +when you've last used calculus, right? + + align:start position:0% +when you've last used calculus, right? + + + align:start position:0% +when you've last used calculus, right? +like we don't all need to become + + align:start position:0% +like we don't all need to become + + + align:start position:0% +like we don't all need to become +mathematicians after we've learned basic + + align:start position:0% +mathematicians after we've learned basic + + + align:start position:0% +mathematicians after we've learned basic +math. Similarly, I do think people + + align:start position:0% +math. Similarly, I do think people + + + align:start position:0% +math. Similarly, I do think people +should learn basic programming, but they + + align:start position:0% +should learn basic programming, but they + + + align:start position:0% +should learn basic programming, but they +don't have to become computer + + align:start position:0% +don't have to become computer + + + align:start position:0% +don't have to become computer +scientists. So, the reason that I enjoy + + align:start position:0% +scientists. So, the reason that I enjoy + + + align:start position:0% +scientists. So, the reason that I enjoy +teaching students intro programming and + + align:start position:0% +teaching students intro programming and + + + align:start position:0% +teaching students intro programming and +exposing them to intromputer science is + + align:start position:0% +exposing them to intromputer science is + + + align:start position:0% +exposing them to intromputer science is +because it was really hard for me to + + align:start position:0% +because it was really hard for me to + + + align:start position:0% +because it was really hard for me to +understand programming when I first + + align:start position:0% +understand programming when I first + + + align:start position:0% +understand programming when I first +started and I just always remember how + + align:start position:0% +started and I just always remember how + + + align:start position:0% +started and I just always remember how +tough it was. + + align:start position:0% +tough it was. + + + align:start position:0% +tough it was. +And I'm at right I teach at MIT and + + align:start position:0% +And I'm at right I teach at MIT and + + + align:start position:0% +And I'm at right I teach at MIT and +there's obviously a lot of really smart + + align:start position:0% +there's obviously a lot of really smart + + + align:start position:0% +there's obviously a lot of really smart +people here. And I think as you teach + + align:start position:0% +people here. And I think as you teach + + + align:start position:0% +people here. And I think as you teach +more and more it's easy to forget how + + align:start position:0% +more and more it's easy to forget how + + + align:start position:0% +more and more it's easy to forget how +hard it was to start learning. And so + + align:start position:0% +hard it was to start learning. And so + + + align:start position:0% +hard it was to start learning. And so +you know as an intro course you know you + + align:start position:0% +you know as an intro course you know you + + + align:start position:0% +you know as an intro course you know you +might make the problems you give + + align:start position:0% +might make the problems you give + + + align:start position:0% +might make the problems you give +students harder and harder each year + + align:start position:0% +students harder and harder each year + + + align:start position:0% +students harder and harder each year +just because they get maybe boring for + + align:start position:0% +just because they get maybe boring for + + + align:start position:0% +just because they get maybe boring for +you but it's not boring for the + + align:start position:0% +you but it's not boring for the + + + align:start position:0% +you but it's not boring for the +students. And I try to recognize that + + align:start position:0% +students. And I try to recognize that + + + align:start position:0% +students. And I try to recognize that +every like every semester I just + + align:start position:0% +every like every semester I just + + + align:start position:0% +every like every semester I just +remember it was really hard for me. + + align:start position:0% +remember it was really hard for me. + + + align:start position:0% +remember it was really hard for me. +they've never seen this before. So, it's + + align:start position:0% +they've never seen this before. So, it's + + + align:start position:0% +they've never seen this before. So, it's +really important to make sure that they + + align:start position:0% +really important to make sure that they + + + align:start position:0% +really important to make sure that they +have a really good experience. You + + align:start position:0% +have a really good experience. You + + + align:start position:0% +have a really good experience. You +mentioned that when you first started + + align:start position:0% +mentioned that when you first started + + + align:start position:0% +mentioned that when you first started +programming it was difficult. Y I'm + + align:start position:0% +programming it was difficult. Y I'm + + + align:start position:0% +programming it was difficult. Y I'm +wondering like what made it difficult + + align:start position:0% +wondering like what made it difficult + + + align:start position:0% +wondering like what made it difficult +and then what are you doing in your + + align:start position:0% +and then what are you doing in your + + + align:start position:0% +and then what are you doing in your +teaching to make it less difficult? I + + align:start position:0% +teaching to make it less difficult? I + + + align:start position:0% +teaching to make it less difficult? I +honestly don't know what made it + + align:start position:0% +honestly don't know what made it + + + align:start position:0% +honestly don't know what made it +difficult. The the beginning was easy + + align:start position:0% +difficult. The the beginning was easy + + + align:start position:0% +difficult. The the beginning was easy +just kind of understanding the basics of + + align:start position:0% +just kind of understanding the basics of + + + align:start position:0% +just kind of understanding the basics of +just you know writing uh the basics of + + align:start position:0% +just you know writing uh the basics of + + + align:start position:0% +just you know writing uh the basics of +creating an algorithm is basically three + + align:start position:0% +creating an algorithm is basically three + + + align:start position:0% +creating an algorithm is basically three +things. So the first is a sequence of + + align:start position:0% +things. So the first is a sequence of + + + align:start position:0% +things. So the first is a sequence of +steps. So step one, step two, step + + align:start position:0% +steps. So step one, step two, step + + + align:start position:0% +steps. So step one, step two, step +three. Um some sort of way to control + + align:start position:0% +three. Um some sort of way to control + + + align:start position:0% +three. Um some sort of way to control +the flow of those steps. So usually you + + align:start position:0% +the flow of those steps. So usually you + + + align:start position:0% +the flow of those steps. So usually you +go step by step, but at some point you + + align:start position:0% +go step by step, but at some point you + + + align:start position:0% +go step by step, but at some point you +say, well, if this is true, do this, + + align:start position:0% +say, well, if this is true, do this, + + + align:start position:0% +say, well, if this is true, do this, +otherwise do this. So like a branching + + align:start position:0% +otherwise do this. So like a branching + + + align:start position:0% +otherwise do this. So like a branching +kind of idea. And then there's also a + + align:start position:0% +kind of idea. And then there's also a + + + align:start position:0% +kind of idea. And then there's also a +way to control the flow by asking the py + + align:start position:0% +way to control the flow by asking the py + + + align:start position:0% +way to control the flow by asking the py +the program to repeat certain lines. So + + align:start position:0% +the program to repeat certain lines. So + + + align:start position:0% +the program to repeat certain lines. So +it's like, well, if this is true, go + + align:start position:0% +it's like, well, if this is true, go + + + align:start position:0% +it's like, well, if this is true, go +back and repeat this a million times, + + align:start position:0% +back and repeat this a million times, + + + align:start position:0% +back and repeat this a million times, +which is very easy for a computer to do. + + align:start position:0% +which is very easy for a computer to do. + + + align:start position:0% +which is very easy for a computer to do. +So a sequence of steps, a way to control + + align:start position:0% +So a sequence of steps, a way to control + + + align:start position:0% +So a sequence of steps, a way to control +the flow of those steps, and then a way + + align:start position:0% +the flow of those steps, and then a way + + + align:start position:0% +the flow of those steps, and then a way +to stop. Those are the three things that + + align:start position:0% +to stop. Those are the three things that + + + align:start position:0% +to stop. Those are the three things that +make an algorithm. That's that's how you + + align:start position:0% +make an algorithm. That's that's how you + + + align:start position:0% +make an algorithm. That's that's how you +write a program. And the grasping that + + align:start position:0% +write a program. And the grasping that + + + align:start position:0% +write a program. And the grasping that +was not hard. It was just sort of once + + align:start position:0% +was not hard. It was just sort of once + + + align:start position:0% +was not hard. It was just sort of once +you've gotten over that learning curve, + + align:start position:0% +you've gotten over that learning curve, + + + align:start position:0% +you've gotten over that learning curve, +it's learning sort of some of the more + + align:start position:0% +it's learning sort of some of the more + + + align:start position:0% +it's learning sort of some of the more +advanced concepts that were + + align:start position:0% +advanced concepts that were + + + align:start position:0% +advanced concepts that were +um that were harder some of the details + + align:start position:0% +um that were harder some of the details + + + align:start position:0% +um that were harder some of the details +for how that specific language works. So + + align:start position:0% +for how that specific language works. So + + + align:start position:0% +for how that specific language works. So +I started with Java, not Python, which + + align:start position:0% +I started with Java, not Python, which + + + align:start position:0% +I started with Java, not Python, which +was a little which was harder than it's + + align:start position:0% +was a little which was harder than it's + + + align:start position:0% +was a little which was harder than it's +a lot harder than Python. There's a + + align:start position:0% +a lot harder than Python. There's a + + + align:start position:0% +a lot harder than Python. There's a +bunch of details that you need to think + + align:start position:0% +bunch of details that you need to think + + + align:start position:0% +bunch of details that you need to think +about there. So I had the opportunity to + + align:start position:0% +about there. So I had the opportunity to + + + align:start position:0% +about there. So I had the opportunity to +watch some of your lecture videos. Yeah. + + align:start position:0% +watch some of your lecture videos. Yeah. + + + align:start position:0% +watch some of your lecture videos. Yeah. +And I noticed that you make space and + + align:start position:0% +And I noticed that you make space and + + + align:start position:0% +And I noticed that you make space and +time for students to practice like right + + align:start position:0% +time for students to practice like right + + + align:start position:0% +time for students to practice like right +in the class itself. Um definitely + + align:start position:0% +in the class itself. Um definitely + + + align:start position:0% +in the class itself. Um definitely +outside the class as well, but like in + + align:start position:0% +outside the class as well, but like in + + + align:start position:0% +outside the class as well, but like in +the actual space where you're teaching. + + align:start position:0% +the actual space where you're teaching. + + + align:start position:0% +the actual space where you're teaching. +And I'm wondering if you could talk + + align:start position:0% +And I'm wondering if you could talk + + + align:start position:0% +And I'm wondering if you could talk +about that a little bit, why you do + + align:start position:0% +about that a little bit, why you do + + + align:start position:0% +about that a little bit, why you do +that. + + align:start position:0% +that. + + + align:start position:0% +that. +Yeah. So, I think I mentioned this + + align:start position:0% +Yeah. So, I think I mentioned this + + + align:start position:0% +Yeah. So, I think I mentioned this +before. I sort of see programming like + + align:start position:0% +before. I sort of see programming like + + + align:start position:0% +before. I sort of see programming like +math is now, but this will be, you know, + + align:start position:0% +math is now, but this will be, you know, + + + align:start position:0% +math is now, but this will be, you know, +many years from now. Um, it's a skill + + align:start position:0% +many years from now. Um, it's a skill + + + align:start position:0% +many years from now. Um, it's a skill +that people need to get that they don't + + align:start position:0% +that people need to get that they don't + + + align:start position:0% +that people need to get that they don't +have yet. And so, if we think about the + + align:start position:0% +have yet. And so, if we think about the + + + align:start position:0% +have yet. And so, if we think about the +way we learn math in school, it's a lot + + align:start position:0% +way we learn math in school, it's a lot + + + align:start position:0% +way we learn math in school, it's a lot +a lot of practice, right? You just + + align:start position:0% +a lot of practice, right? You just + + + align:start position:0% +a lot of practice, right? You just +always constantly practice adding, + + align:start position:0% +always constantly practice adding, + + + align:start position:0% +always constantly practice adding, +subtracting, multiplying, right? The + + align:start position:0% +subtracting, multiplying, right? The + + + align:start position:0% +subtracting, multiplying, right? The +kids. Yeah. So I think it's very + + align:start position:0% +kids. Yeah. So I think it's very + + + align:start position:0% +kids. Yeah. So I think it's very +important for students to actually get + + align:start position:0% +important for students to actually get + + + align:start position:0% +important for students to actually get +the time to to do to do that practice. + + align:start position:0% +the time to to do to do that practice. + + + align:start position:0% +the time to to do to do that practice. +The way I run the class is a sort of a + + align:start position:0% +The way I run the class is a sort of a + + + align:start position:0% +The way I run the class is a sort of a +flip classroom or a blended learning + + align:start position:0% +flip classroom or a blended learning + + + align:start position:0% +flip classroom or a blended learning +style where students watch sort of the + + align:start position:0% +style where students watch sort of the + + + align:start position:0% +style where students watch sort of the +basics through video first and then in + + align:start position:0% +basics through video first and then in + + + align:start position:0% +basics through video first and then in +the actual classroom we do active + + align:start position:0% +the actual classroom we do active + + + align:start position:0% +the actual classroom we do active +learning. So, uh, I go over maybe + + align:start position:0% +learning. So, uh, I go over maybe + + + align:start position:0% +learning. So, uh, I go over maybe +something that's a little bit more + + align:start position:0% +something that's a little bit more + + + align:start position:0% +something that's a little bit more +confusing and then I give them time to + + align:start position:0% +confusing and then I give them time to + + + align:start position:0% +confusing and then I give them time to +break with the hope that me forcing them + + align:start position:0% +break with the hope that me forcing them + + + align:start position:0% +break with the hope that me forcing them +to have them actually start coding, + + align:start position:0% +to have them actually start coding, + + + align:start position:0% +to have them actually start coding, +they'll be able to see, oh, um, I + + align:start position:0% +they'll be able to see, oh, um, I + + + align:start position:0% +they'll be able to see, oh, um, I +totally understood what she was talking + + align:start position:0% +totally understood what she was talking + + + align:start position:0% +totally understood what she was talking +about in the video and I can totally + + align:start position:0% +about in the video and I can totally + + + align:start position:0% +about in the video and I can totally +code that, but then when they actually + + align:start position:0% +code that, but then when they actually + + + align:start position:0% +code that, but then when they actually +when I'm forcing them to actually do it, + + align:start position:0% +when I'm forcing them to actually do it, + + + align:start position:0% +when I'm forcing them to actually do it, +you know, starting with a blank slate, + + align:start position:0% +you know, starting with a blank slate, + + + align:start position:0% +you know, starting with a blank slate, +it's pretty daunting. And so I want them + + align:start position:0% +it's pretty daunting. And so I want them + + + align:start position:0% +it's pretty daunting. And so I want them +to get over that bump where it's like + + align:start position:0% +to get over that bump where it's like + + + align:start position:0% +to get over that bump where it's like +you have a blank piece of, you know, + + align:start position:0% +you have a blank piece of, you know, + + + align:start position:0% +you have a blank piece of, you know, +blank editor or whatever. And then you + + align:start position:0% +blank editor or whatever. And then you + + + align:start position:0% +blank editor or whatever. And then you +just have to start writing something + + align:start position:0% +just have to start writing something + + + align:start position:0% +just have to start writing something +down once the more you do it, the more + + align:start position:0% +down once the more you do it, the more + + + align:start position:0% +down once the more you do it, the more +you feel comfortable with it. So there's + + align:start position:0% +you feel comfortable with it. So there's + + + align:start position:0% +you feel comfortable with it. So there's +all these breaks for all these + + align:start position:0% +all these breaks for all these + + + align:start position:0% +all these breaks for all these +activities that I that I try to keep the + + align:start position:0% +activities that I that I try to keep the + + + align:start position:0% +activities that I that I try to keep the +class lively, of course, and and kind of + + align:start position:0% +class lively, of course, and and kind of + + + align:start position:0% +class lively, of course, and and kind of +indirectly have them practice these + + align:start position:0% +indirectly have them practice these + + + align:start position:0% +indirectly have them practice these +skills like just just write something + + align:start position:0% +skills like just just write something + + + align:start position:0% +skills like just just write something +just write something down. Yeah. And + + align:start position:0% +just write something down. Yeah. And + + + align:start position:0% +just write something down. Yeah. And +also that does two things I think. Um it + + align:start position:0% +also that does two things I think. Um it + + + align:start position:0% +also that does two things I think. Um it +deemphasizes perfection. You're like + + align:start position:0% +deemphasizes perfection. You're like + + + align:start position:0% +deemphasizes perfection. You're like +this is practice like Yep. I think like + + align:start position:0% +this is practice like Yep. I think like + + + align:start position:0% +this is practice like Yep. I think like +an artist, right? So just like get a + + align:start position:0% +an artist, right? So just like get a + + + align:start position:0% +an artist, right? So just like get a +sketch, write a few lines like just get + + align:start position:0% +sketch, write a few lines like just get + + + align:start position:0% +sketch, write a few lines like just get +something down. Yes. And then we can + + align:start position:0% +something down. Yes. And then we can + + + align:start position:0% +something down. Yes. And then we can +improve it. Yep. Um and then that speaks + + align:start position:0% +improve it. Yep. Um and then that speaks + + + align:start position:0% +improve it. Yep. Um and then that speaks +to something else you've mentioned + + align:start position:0% +to something else you've mentioned + + + align:start position:0% +to something else you've mentioned +before and that's like growth mindset + + align:start position:0% +before and that's like growth mindset + + + align:start position:0% +before and that's like growth mindset +and that programming is not like a gift + + align:start position:0% +and that programming is not like a gift + + + align:start position:0% +and that programming is not like a gift +and you have it or you don't but it's + + align:start position:0% +and you have it or you don't but it's + + + align:start position:0% +and you have it or you don't but it's +really something that can be developed. + + align:start position:0% +really something that can be developed. + + + align:start position:0% +really something that can be developed. +Yeah. A lot of a lot of you know you see + + align:start position:0% +Yeah. A lot of a lot of you know you see + + + align:start position:0% +Yeah. A lot of a lot of you know you see +some people who are really good at + + align:start position:0% +some people who are really good at + + + align:start position:0% +some people who are really good at +programming they didn't get good just + + align:start position:0% +programming they didn't get good just + + + align:start position:0% +programming they didn't get good just +because they had that skill they were + + align:start position:0% +because they had that skill they were + + + align:start position:0% +because they had that skill they were +born with it right there's a lot of + + align:start position:0% +born with it right there's a lot of + + + align:start position:0% +born with it right there's a lot of +growth mindset involved in that and + + align:start position:0% +growth mindset involved in that and + + + align:start position:0% +growth mindset involved in that and +anybody can reach that level of being + + align:start position:0% +anybody can reach that level of being + + + align:start position:0% +anybody can reach that level of being +good at at something programming + + align:start position:0% +good at at something programming + + + align:start position:0% +good at at something programming +included just by lots of practice trying + + align:start position:0% +included just by lots of practice trying + + + align:start position:0% +included just by lots of practice trying +different things challenging themselves + + align:start position:0% +different things challenging themselves + + + align:start position:0% +different things challenging themselves +so not just sticking to things that are + + align:start position:0% +so not just sticking to things that are + + + align:start position:0% +so not just sticking to things that are +obviously way too easy because then + + align:start position:0% +obviously way too easy because then + + + align:start position:0% +obviously way too easy because then +you'll never grow but you kind of like I + + align:start position:0% +you'll never grow but you kind of like I + + + align:start position:0% +you'll never grow but you kind of like I +don't know if you know this um the state + + align:start position:0% +don't know if you know this um the state + + + align:start position:0% +don't know if you know this um the state +of flow. It's like this chart where you + + align:start position:0% +of flow. It's like this chart where you + + + align:start position:0% +of flow. It's like this chart where you +kind of want to be in this like middle + + align:start position:0% +kind of want to be in this like middle + + + align:start position:0% +kind of want to be in this like middle +band + + align:start position:0% +band + + + align:start position:0% +band +um but kind of oscillating between doing + + align:start position:0% +um but kind of oscillating between doing + + + align:start position:0% +um but kind of oscillating between doing +things that are too easy and then + + align:start position:0% +things that are too easy and then + + + align:start position:0% +things that are too easy and then +challenging yourself and doing things + + align:start position:0% +challenging yourself and doing things + + + align:start position:0% +challenging yourself and doing things +that a little bit harder. Um and not you + + align:start position:0% +that a little bit harder. Um and not you + + + align:start position:0% +that a little bit harder. Um and not you +don't want to always do two things too + + align:start position:0% +don't want to always do two things too + + + align:start position:0% +don't want to always do two things too +hard because then that's discouraging + + align:start position:0% +hard because then that's discouraging + + + align:start position:0% +hard because then that's discouraging +and you'll stop. But you don't want to + + align:start position:0% +and you'll stop. But you don't want to + + + align:start position:0% +and you'll stop. But you don't want to +do things that are always too easy + + align:start position:0% +do things that are always too easy + + + align:start position:0% +do things that are always too easy +because then you'll never grow. I wonder + + align:start position:0% +because then you'll never grow. I wonder + + + align:start position:0% +because then you'll never grow. I wonder +if we could write an algorithm for + + align:start position:0% +if we could write an algorithm for + + + align:start position:0% +if we could write an algorithm for +staying in the flow like it tracks like + + align:start position:0% +staying in the flow like it tracks like + + + align:start position:0% +staying in the flow like it tracks like +oh this is too easy for you get in a lot + + align:start position:0% +oh this is too easy for you get in a lot + + + align:start position:0% +oh this is too easy for you get in a lot +of the education platforms right are + + align:start position:0% +of the education platforms right are + + + align:start position:0% +of the education platforms right are +trying to give uh students based on + + align:start position:0% +trying to give uh students based on + + + align:start position:0% +trying to give uh students based on +their responses you know even in math + + align:start position:0% +their responses you know even in math + + + align:start position:0% +their responses you know even in math +questions right and be like oh this + + align:start position:0% +questions right and be like oh this + + + align:start position:0% +questions right and be like oh this +student totally got all these let me + + align:start position:0% +student totally got all these let me + + + align:start position:0% +student totally got all these let me +give them a harder one and it's like oh + + align:start position:0% +give them a harder one and it's like oh + + + align:start position:0% +give them a harder one and it's like oh +that was too hard let me yeah how did + + align:start position:0% +that was too hard let me yeah how did + + + align:start position:0% +that was too hard let me yeah how did +you find your way to programming is this + + align:start position:0% +you find your way to programming is this + + + align:start position:0% +you find your way to programming is this +something that you've always wanted to + + align:start position:0% +something that you've always wanted to + + + align:start position:0% +something that you've always wanted to +do or did it develop along the way um so + + align:start position:0% +do or did it develop along the way um so + + + align:start position:0% +do or did it develop along the way um so +my my parents immigrated from Romania + + align:start position:0% +my my parents immigrated from Romania + + + align:start position:0% +my my parents immigrated from Romania +and we went uh we immigrated to Canada + + align:start position:0% +and we went uh we immigrated to Canada + + + align:start position:0% +and we went uh we immigrated to Canada +and my dad was a electrical engineer and + + align:start position:0% +and my dad was a electrical engineer and + + + align:start position:0% +and my dad was a electrical engineer and +then he went into software engineering + + align:start position:0% +then he went into software engineering + + + align:start position:0% +then he went into software engineering +and uh being an immigrant uh immigrant + + align:start position:0% +and uh being an immigrant uh immigrant + + + align:start position:0% +and uh being an immigrant uh immigrant +parents from Europe uh we were highly + + align:start position:0% +parents from Europe uh we were highly + + + align:start position:0% +parents from Europe uh we were highly +encouraged my sister and I were highly + + align:start position:0% +encouraged my sister and I were highly + + + align:start position:0% +encouraged my sister and I were highly +encouraged to get uh some sort of + + align:start position:0% +encouraged to get uh some sort of + + + align:start position:0% +encouraged to get uh some sort of +engineering job right so it's just what + + align:start position:0% +engineering job right so it's just what + + + align:start position:0% +engineering job right so it's just what +what what is done and so uh computer + + align:start position:0% +what what is done and so uh computer + + + align:start position:0% +what what is done and so uh computer +computer engineering or computer + + align:start position:0% +computer engineering or computer + + + align:start position:0% +computer engineering or computer +science, something along those lines + + align:start position:0% +science, something along those lines + + + align:start position:0% +science, something along those lines +seemed to be the best option uh given + + align:start position:0% +seemed to be the best option uh given + + + align:start position:0% +seemed to be the best option uh given +sort of where things were going in the + + align:start position:0% +sort of where things were going in the + + + align:start position:0% +sort of where things were going in the +future. This was the '9s. Um so just the + + align:start position:0% +future. This was the '9s. Um so just the + + + align:start position:0% +future. This was the '9s. Um so just the +beginning of the internet, the beginning + + align:start position:0% +beginning of the internet, the beginning + + + align:start position:0% +beginning of the internet, the beginning +of all that um right that boom. Uh, so + + align:start position:0% +of all that um right that boom. Uh, so + + + align:start position:0% +of all that um right that boom. Uh, so +my dad recognized that that was sort of + + align:start position:0% +my dad recognized that that was sort of + + + align:start position:0% +my dad recognized that that was sort of +what the what the future would be and he + + align:start position:0% +what the what the future would be and he + + + align:start position:0% +what the what the future would be and he +said, "You should probably learn to + + align:start position:0% +said, "You should probably learn to + + + align:start position:0% +said, "You should probably learn to +program and potentially go, you know, + + align:start position:0% +program and potentially go, you know, + + + align:start position:0% +program and potentially go, you know, +and probably go into that sort of + + align:start position:0% +and probably go into that sort of + + + align:start position:0% +and probably go into that sort of +career." And I wasn't super interested + + align:start position:0% +career." And I wasn't super interested + + + align:start position:0% +career." And I wasn't super interested +in anything else, so I just said, + + align:start position:0% +in anything else, so I just said, + + + align:start position:0% +in anything else, so I just said, +"Sure." Um, and so he taught us Java + + align:start position:0% +"Sure." Um, and so he taught us Java + + + align:start position:0% +"Sure." Um, and so he taught us Java +when I was about 12. Um, I have a a + + align:start position:0% +when I was about 12. Um, I have a a + + + align:start position:0% +when I was about 12. Um, I have a a +picture here. Oh, yeah. Let's see it. + + align:start position:0% +picture here. Oh, yeah. Let's see it. + + + align:start position:0% +picture here. Oh, yeah. Let's see it. +Okay. And it's in this really cool + + align:start position:0% +Okay. And it's in this really cool + + + align:start position:0% +Okay. And it's in this really cool +frame. Oh, I love that frame. Okay. Uh, + + align:start position:0% +frame. Oh, I love that frame. Okay. Uh, + + + align:start position:0% +frame. Oh, I love that frame. Okay. Uh, +very fitting. And so this is this um + + align:start position:0% +very fitting. And so this is this um + + + align:start position:0% +very fitting. And so this is this um +this is very '9s. Like this exudes '90s. + + align:start position:0% +this is very '9s. Like this exudes '90s. + + + align:start position:0% +this is very '9s. Like this exudes '90s. +Peak '9s right there. So we've got the + + align:start position:0% +Peak '9s right there. So we've got the + + + align:start position:0% +Peak '9s right there. So we've got the +room with the computer, right? Like as + + align:start position:0% +room with the computer, right? Like as + + + align:start position:0% +room with the computer, right? Like as +was in the '9s. You all had like the + + align:start position:0% +was in the '9s. You all had like the + + + align:start position:0% +was in the '9s. You all had like the +room with the computer. Yes. And then + + align:start position:0% +room with the computer. Yes. And then + + + align:start position:0% +room with the computer. Yes. And then +like the big chair and the side ponytail + + align:start position:0% +like the big chair and the side ponytail + + + align:start position:0% +like the big chair and the side ponytail +or whatever. That's me on the on the on + + align:start position:0% +or whatever. That's me on the on the on + + + align:start position:0% +or whatever. That's me on the on the on +the left there. That's me. Yep. Yep. And + + align:start position:0% +the left there. That's me. Yep. Yep. And + + + align:start position:0% +the left there. That's me. Yep. Yep. And +that's my sister in the on the chair. Uh + + align:start position:0% +that's my sister in the on the chair. Uh + + + align:start position:0% +that's my sister in the on the chair. Uh +sitting on the chair. Yeah. And that's + + align:start position:0% +sitting on the chair. Yeah. And that's + + + align:start position:0% +sitting on the chair. Yeah. And that's +when we first um or maybe before like + + align:start position:0% +when we first um or maybe before like + + + align:start position:0% +when we first um or maybe before like +very close to the time that we had first + + align:start position:0% +very close to the time that we had first + + + align:start position:0% +very close to the time that we had first +uh started programming. My dad just + + align:start position:0% +uh started programming. My dad just + + + align:start position:0% +uh started programming. My dad just +said, you know, here's you know, here's + + align:start position:0% +said, you know, here's you know, here's + + + align:start position:0% +said, you know, here's you know, here's +some really basic things. And then I + + align:start position:0% +some really basic things. And then I + + + align:start position:0% +some really basic things. And then I +only got to the the if like the the + + align:start position:0% +only got to the the if like the the + + + align:start position:0% +only got to the the if like the the +branching part of the control flow. I + + align:start position:0% +branching part of the control flow. I + + + align:start position:0% +branching part of the control flow. I +didn't really get to the repeating part + + align:start position:0% +didn't really get to the repeating part + + + align:start position:0% +didn't really get to the repeating part +of the control flow. So I made this + + align:start position:0% +of the control flow. So I made this + + + align:start position:0% +of the control flow. So I made this +choose your own adventure program where + + align:start position:0% +choose your own adventure program where + + + align:start position:0% +choose your own adventure program where +it was like I forget what it was like. + + align:start position:0% +it was like I forget what it was like. + + + align:start position:0% +it was like I forget what it was like. +get out and you know exit a castle or + + align:start position:0% +get out and you know exit a castle or + + + align:start position:0% +get out and you know exit a castle or +whatever it was and it was just like a + + align:start position:0% +whatever it was and it was just like a + + + align:start position:0% +whatever it was and it was just like a +bunch of if else if else if else if else + + align:start position:0% +bunch of if else if else if else if else + + + align:start position:0% +bunch of if else if else if else if else +if like something like that. It looked + + align:start position:0% +if like something like that. It looked + + + align:start position:0% +if like something like that. It looked +really ugly but I had a lot of fun doing + + align:start position:0% +really ugly but I had a lot of fun doing + + + align:start position:0% +really ugly but I had a lot of fun doing +it. But in a way you're helping people + + align:start position:0% +it. But in a way you're helping people + + + align:start position:0% +it. But in a way you're helping people +choose their own adventure today through + + align:start position:0% +choose their own adventure today through + + + align:start position:0% +choose their own adventure today through +programming like gaining independence, + + align:start position:0% +programming like gaining independence, + + + align:start position:0% +programming like gaining independence, +critical thinking, uh doing things that + + align:start position:0% +critical thinking, uh doing things that + + + align:start position:0% +critical thinking, uh doing things that +they rely on other people to do like + + align:start position:0% +they rely on other people to do like + + + align:start position:0% +they rely on other people to do like +they can do themselves. Like that's kind + + align:start position:0% +they can do themselves. Like that's kind + + + align:start position:0% +they can do themselves. Like that's kind +of incredible that you do that. It's + + align:start position:0% +of incredible that you do that. It's + + + align:start position:0% +of incredible that you do that. It's +pretty fun. That's that's what I get out + + align:start position:0% +pretty fun. That's that's what I get out + + + align:start position:0% +pretty fun. That's that's what I get out +of it. I like I said, I don't want + + align:start position:0% +of it. I like I said, I don't want + + + align:start position:0% +of it. I like I said, I don't want +people to become computer scientists. I + + align:start position:0% +people to become computer scientists. I + + + align:start position:0% +people to become computer scientists. I +just want to empower them to I don't + + align:start position:0% +just want to empower them to I don't + + + align:start position:0% +just want to empower them to I don't +know like if they want to make their own + + align:start position:0% +know like if they want to make their own + + + align:start position:0% +know like if they want to make their own +app, they can totally do that using + + align:start position:0% +app, they can totally do that using + + + align:start position:0% +app, they can totally do that using +really basic computer science skills or + + align:start position:0% +really basic computer science skills or + + + align:start position:0% +really basic computer science skills or +programming skills, not necessarily + + align:start position:0% +programming skills, not necessarily + + + align:start position:0% +programming skills, not necessarily +computer science skills, but yeah. Yeah. + + align:start position:0% +computer science skills, but yeah. Yeah. + + + align:start position:0% +computer science skills, but yeah. Yeah. +So, uh controversial question. Uh I + + align:start position:0% +So, uh controversial question. Uh I + + + align:start position:0% +So, uh controversial question. Uh I +asked you before the show a question and + + align:start position:0% +asked you before the show a question and + + + align:start position:0% +asked you before the show a question and +I have not seen the answer yet but um + + align:start position:0% +I have not seen the answer yet but um + + + align:start position:0% +I have not seen the answer yet but um +the question was um in an environment + + align:start position:0% +the question was um in an environment + + + align:start position:0% +the question was um in an environment +when there are coding tools out there + + align:start position:0% +when there are coding tools out there + + + align:start position:0% +when there are coding tools out there +that allow people to build things um + + align:start position:0% +that allow people to build things um + + + align:start position:0% +that allow people to build things um +what's the value proposition of learning + + align:start position:0% +what's the value proposition of learning + + + align:start position:0% +what's the value proposition of learning +a language like Python to do that? Like + + align:start position:0% +a language like Python to do that? Like + + + align:start position:0% +a language like Python to do that? Like +do we still need to do it? And what's + + align:start position:0% +do we still need to do it? And what's + + + align:start position:0% +do we still need to do it? And what's +the value proposition of doing it? So + + align:start position:0% +the value proposition of doing it? So + + + align:start position:0% +the value proposition of doing it? So +you're going to reveal your answer. I'll + + align:start position:0% +you're going to reveal your answer. I'll + + + align:start position:0% +you're going to reveal your answer. I'll +reveal my answer. + + align:start position:0% +reveal my answer. + + + align:start position:0% +reveal my answer. +So, not sure if this exactly answers the + + align:start position:0% +So, not sure if this exactly answers the + + + align:start position:0% +So, not sure if this exactly answers the +question, but I said trust, but verify. + + align:start position:0% +question, but I said trust, but verify. + + + align:start position:0% +question, but I said trust, but verify. +Oh, tell me more. Okay. Yeah, I've + + align:start position:0% +Oh, tell me more. Okay. Yeah, I've + + + align:start position:0% +Oh, tell me more. Okay. Yeah, I've +certainly definitely used Genaii tools + + align:start position:0% +certainly definitely used Genaii tools + + + align:start position:0% +certainly definitely used Genaii tools +before. And for even for really simple + + align:start position:0% +before. And for even for really simple + + + align:start position:0% +before. And for even for really simple +things, it can get it wrong, especially + + align:start position:0% +things, it can get it wrong, especially + + + align:start position:0% +things, it can get it wrong, especially +um mathematical things and even + + align:start position:0% +um mathematical things and even + + + align:start position:0% +um mathematical things and even +programming things. And so, I have sort + + align:start position:0% +programming things. And so, I have sort + + + align:start position:0% +programming things. And so, I have sort +of a I would say a basic knowledge of + + align:start position:0% +of a I would say a basic knowledge of + + + align:start position:0% +of a I would say a basic knowledge of +programming. And I Wait, I'm not ready. + + align:start position:0% +programming. And I Wait, I'm not ready. + + + align:start position:0% +programming. And I Wait, I'm not ready. +IoT is a little more than basic for + + align:start position:0% +IoT is a little more than basic for + + + align:start position:0% +IoT is a little more than basic for +everyone out there. More than basic. + + align:start position:0% +everyone out there. More than basic. + + + align:start position:0% +everyone out there. More than basic. +Continue. Um, and so I was able to start + + align:start position:0% +Continue. Um, and so I was able to start + + + align:start position:0% +Continue. Um, and so I was able to start +with what Genai gave me as a as as a + + align:start position:0% +with what Genai gave me as a as as a + + + align:start position:0% +with what Genai gave me as a as as a +program and kind of kind of tell, you + + align:start position:0% +program and kind of kind of tell, you + + + align:start position:0% +program and kind of kind of tell, you +know what, it in this particular test + + align:start position:0% +know what, it in this particular test + + + align:start position:0% +know what, it in this particular test +case, it doesn't really work that well. + + align:start position:0% +case, it doesn't really work that well. + + + align:start position:0% +case, it doesn't really work that well. +And I didn't have to go back and ask it + + align:start position:0% +And I didn't have to go back and ask it + + + align:start position:0% +And I didn't have to go back and ask it +to fix it because that requires a lot + + align:start position:0% +to fix it because that requires a lot + + + align:start position:0% +to fix it because that requires a lot +more sort of back and forth with the + + align:start position:0% +more sort of back and forth with the + + + align:start position:0% +more sort of back and forth with the +with prompting. And I was able, you + + align:start position:0% +with prompting. And I was able, you + + + align:start position:0% +with prompting. And I was able, you +know, to just fix it on my own. It + + align:start position:0% +know, to just fix it on my own. It + + + align:start position:0% +know, to just fix it on my own. It +wasn't that hard of a fix. And, you + + align:start position:0% +wasn't that hard of a fix. And, you + + + align:start position:0% +wasn't that hard of a fix. And, you +know, as soon as you go back and prompt + + align:start position:0% +know, as soon as you go back and prompt + + + align:start position:0% +know, as soon as you go back and prompt +the the genai again and again and again, + + align:start position:0% +the the genai again and again and again, + + + align:start position:0% +the the genai again and again and again, +you start to introduce sort of + + align:start position:0% +you start to introduce sort of + + + align:start position:0% +you start to introduce sort of +variability of English language, right? + + align:start position:0% +variability of English language, right? + + + align:start position:0% +variability of English language, right? +You're like when you're talking to + + align:start position:0% +You're like when you're talking to + + + align:start position:0% +You're like when you're talking to +someone online, it's really hard to tell + + align:start position:0% +someone online, it's really hard to tell + + + align:start position:0% +someone online, it's really hard to tell +what they mean or right, there's all + + align:start position:0% +what they mean or right, there's all + + + align:start position:0% +what they mean or right, there's all +these double meanings. Um, and Genai is + + align:start position:0% +these double meanings. Um, and Genai is + + + align:start position:0% +these double meanings. Um, and Genai is +all probabilistic. So they're basically + + align:start position:0% +all probabilistic. So they're basically + + + align:start position:0% +all probabilistic. So they're basically +going to, you know, pick the highest + + align:start position:0% +going to, you know, pick the highest + + + align:start position:0% +going to, you know, pick the highest +probability of what you mean and then + + align:start position:0% +probability of what you mean and then + + + align:start position:0% +probability of what you mean and then +when they give you answers back again, + + align:start position:0% +when they give you answers back again, + + + align:start position:0% +when they give you answers back again, +they give it to you with whatever the + + align:start position:0% +they give it to you with whatever the + + + align:start position:0% +they give it to you with whatever the +highest probability for the next word to + + align:start position:0% +highest probability for the next word to + + + align:start position:0% +highest probability for the next word to +be, that's what they spit back at you. + + align:start position:0% +be, that's what they spit back at you. + + + align:start position:0% +be, that's what they spit back at you. +So as soon as you introduce sort of that + + align:start position:0% +So as soon as you introduce sort of that + + + align:start position:0% +So as soon as you introduce sort of that +prompting back and forth, it can + + align:start position:0% +prompting back and forth, it can + + + align:start position:0% +prompting back and forth, it can +introduce errors that potentially stack + + align:start position:0% +introduce errors that potentially stack + + + align:start position:0% +introduce errors that potentially stack +on top of errors, misunderstandings, and + + align:start position:0% +on top of errors, misunderstandings, and + + + align:start position:0% +on top of errors, misunderstandings, and +things like that. So having a really + + align:start position:0% +things like that. So having a really + + + align:start position:0% +things like that. So having a really +basic knowledge of programming could + + align:start position:0% +basic knowledge of programming could + + + align:start position:0% +basic knowledge of programming could +allow you to maybe start with a piece of + + align:start position:0% +allow you to maybe start with a piece of + + + align:start position:0% +allow you to maybe start with a piece of +code that the Genai gives you back so + + align:start position:0% +code that the Genai gives you back so + + + align:start position:0% +code that the Genai gives you back so +you're not starting with a blank slate. + + align:start position:0% +you're not starting with a blank slate. + + + align:start position:0% +you're not starting with a blank slate. +It's not super daunting to write it + + align:start position:0% +It's not super daunting to write it + + + align:start position:0% +It's not super daunting to write it +yourself, but you start with something + + align:start position:0% +yourself, but you start with something + + + align:start position:0% +yourself, but you start with something +and then you potentially test it and + + align:start position:0% +and then you potentially test it and + + + align:start position:0% +and then you potentially test it and +then debug it and then, you know, figure + + align:start position:0% +then debug it and then, you know, figure + + + align:start position:0% +then debug it and then, you know, figure +it out. Okay, now I trust that it works + + align:start position:0% +it out. Okay, now I trust that it works + + + align:start position:0% +it out. Okay, now I trust that it works +well. Yeah. I feel like the ability to + + align:start position:0% +well. Yeah. I feel like the ability to + + + align:start position:0% +well. Yeah. I feel like the ability to +verify is the human component. Yes. And + + align:start position:0% +verify is the human component. Yes. And + + + align:start position:0% +verify is the human component. Yes. And +that is sort of what creates the balance + + align:start position:0% +that is sort of what creates the balance + + + align:start position:0% +that is sort of what creates the balance +with AI. Like if you let AI make all the + + align:start position:0% +with AI. Like if you let AI make all the + + + align:start position:0% +with AI. Like if you let AI make all the +decisions, then you've lost your + + align:start position:0% +decisions, then you've lost your + + + align:start position:0% +decisions, then you've lost your +self-reliance. Um, and you can't choose + + align:start position:0% +self-reliance. Um, and you can't choose + + + align:start position:0% +self-reliance. Um, and you can't choose +your own adventure because you're going + + align:start position:0% +your own adventure because you're going + + + align:start position:0% +your own adventure because you're going +to get a bunch of errors and it's going + + align:start position:0% +to get a bunch of errors and it's going + + + align:start position:0% +to get a bunch of errors and it's going +to lead you down the wrong path. So, you + + align:start position:0% +to lead you down the wrong path. So, you + + + align:start position:0% +to lead you down the wrong path. So, you +need the knowledge to be able to choose + + align:start position:0% +need the knowledge to be able to choose + + + align:start position:0% +need the knowledge to be able to choose +um a path that makes sense. Yeah. I have + + align:start position:0% +um a path that makes sense. Yeah. I have + + + align:start position:0% +um a path that makes sense. Yeah. I have +to know what the ducks are now. Like I I + + align:start position:0% +to know what the ducks are now. Like I I + + + align:start position:0% +to know what the ducks are now. Like I I +can't continue. So, okay. And a pig. I'm + + align:start position:0% +can't continue. So, okay. And a pig. I'm + + + align:start position:0% +can't continue. So, okay. And a pig. I'm +Is that like noisy data or just noisy + + align:start position:0% +Is that like noisy data or just noisy + + + align:start position:0% +Is that like noisy data or just noisy +data? Okay. So, okay. Uh every semester + + align:start position:0% +data? Okay. So, okay. Uh every semester + + + align:start position:0% +data? Okay. So, okay. Uh every semester +when we run our classes uh on intro to + + align:start position:0% +when we run our classes uh on intro to + + + align:start position:0% +when we run our classes uh on intro to +programming and computer science, there + + align:start position:0% +programming and computer science, there + + + align:start position:0% +programming and computer science, there +is one particular class that is on + + align:start position:0% +is one particular class that is on + + + align:start position:0% +is one particular class that is on +debugging. Okay. which is the process of + + align:start position:0% +debugging. Okay. which is the process of + + + align:start position:0% +debugging. Okay. which is the process of +okay, you wrote a piece of code and it's + + align:start position:0% +okay, you wrote a piece of code and it's + + + align:start position:0% +okay, you wrote a piece of code and it's +not running as you expect it to. So how + + align:start position:0% +not running as you expect it to. So how + + + align:start position:0% +not running as you expect it to. So how +do you fix it? That is the debugging + + align:start position:0% +do you fix it? That is the debugging + + + align:start position:0% +do you fix it? That is the debugging +process. And so a a lot of times a bunch + + align:start position:0% +process. And so a a lot of times a bunch + + + align:start position:0% +process. And so a a lot of times a bunch +of the errors might be things that you + + align:start position:0% +of the errors might be things that you + + + align:start position:0% +of the errors might be things that you +can easily fix but most of the time uh + + align:start position:0% +can easily fix but most of the time uh + + + align:start position:0% +can easily fix but most of the time uh +your program runs fine and it gives you + + align:start position:0% +your program runs fine and it gives you + + + align:start position:0% +your program runs fine and it gives you +an answer but the answer is not what you + + align:start position:0% +an answer but the answer is not what you + + + align:start position:0% +an answer but the answer is not what you +thought it should be. That's kind of + + align:start position:0% +thought it should be. That's kind of + + + align:start position:0% +thought it should be. That's kind of +where like uh programming is kind of + + align:start position:0% +where like uh programming is kind of + + + align:start position:0% +where like uh programming is kind of +different than like English for example + + align:start position:0% +different than like English for example + + + align:start position:0% +different than like English for example +because in English like if you write a + + align:start position:0% +because in English like if you write a + + + align:start position:0% +because in English like if you write a +sentence somebody else can interpret it + + align:start position:0% +sentence somebody else can interpret it + + + align:start position:0% +sentence somebody else can interpret it +however they'd like. Like one example we + + align:start position:0% +however they'd like. Like one example we + + + align:start position:0% +however they'd like. Like one example we +give to students is the chicken is ready + + align:start position:0% +give to students is the chicken is ready + + + align:start position:0% +give to students is the chicken is ready +to eat. What do you think about when you + + align:start position:0% +to eat. What do you think about when you + + + align:start position:0% +to eat. What do you think about when you +when I say the chicken is ready to eat? + + align:start position:0% +when I say the chicken is ready to eat? + + + align:start position:0% +when I say the chicken is ready to eat? +Well I'm a vegetarian so I don't want to + + align:start position:0% +Well I'm a vegetarian so I don't want to + + + align:start position:0% +Well I'm a vegetarian so I don't want to +actually eat the chicken but I would + + align:start position:0% +actually eat the chicken but I would + + + align:start position:0% +actually eat the chicken but I would +like because I'm a vegetarian I assume + + align:start position:0% +like because I'm a vegetarian I assume + + + align:start position:0% +like because I'm a vegetarian I assume +the chicken wants to eat his food. Okay, + + align:start position:0% +the chicken wants to eat his food. Okay, + + + align:start position:0% +the chicken wants to eat his food. Okay, +there you go. But I would assume I enjoy + + align:start position:0% +there you go. But I would assume I enjoy + + + align:start position:0% +there you go. But I would assume I enjoy +meat. + + align:start position:0% +meat. + + + align:start position:0% +meat. +So, so I my uh my take on that is uh I + + align:start position:0% +So, so I my uh my take on that is uh I + + + align:start position:0% +So, so I my uh my take on that is uh I +have a chicken on the table and I'm + + align:start position:0% +have a chicken on the table and I'm + + + align:start position:0% +have a chicken on the table and I'm +going to eat it. Right. So, there's two + + align:start position:0% +going to eat it. Right. So, there's two + + + align:start position:0% +going to eat it. Right. So, there's two +interpretations to that. But when we + + align:start position:0% +interpretations to that. But when we + + + align:start position:0% +interpretations to that. But when we +write code, there's only one way to + + align:start position:0% +write code, there's only one way to + + + align:start position:0% +write code, there's only one way to +interpret that piece of code that is + + align:start position:0% +interpret that piece of code that is + + + align:start position:0% +interpret that piece of code that is +written, right? So, um, so that's where + + align:start position:0% +written, right? So, um, so that's where + + + align:start position:0% +written, right? So, um, so that's where +things go wrong in our code because + + align:start position:0% +things go wrong in our code because + + + align:start position:0% +things go wrong in our code because +we're like, well, it should work because + + align:start position:0% +we're like, well, it should work because + + + align:start position:0% +we're like, well, it should work because +in my mind, like when I kind of thought + + align:start position:0% +in my mind, like when I kind of thought + + + align:start position:0% +in my mind, like when I kind of thought +about it, it's supposed to give me the + + align:start position:0% +about it, it's supposed to give me the + + + align:start position:0% +about it, it's supposed to give me the +right answer, but it doesn't, right? And + + align:start position:0% +right answer, but it doesn't, right? And + + + align:start position:0% +right answer, but it doesn't, right? And +so, obviously, the program is the one + + align:start position:0% +so, obviously, the program is the one + + + align:start position:0% +so, obviously, the program is the one +who's wrong because the computer is + + align:start position:0% +who's wrong because the computer is + + + align:start position:0% +who's wrong because the computer is +merely following the algorithm, the set + + align:start position:0% +merely following the algorithm, the set + + + align:start position:0% +merely following the algorithm, the set +of instructions, and there's only one + + align:start position:0% +of instructions, and there's only one + + + align:start position:0% +of instructions, and there's only one +way to follow those instructions. That's + + align:start position:0% +way to follow those instructions. That's + + + align:start position:0% +way to follow those instructions. That's +basically what that whole lecture, that + + align:start position:0% +basically what that whole lecture, that + + + align:start position:0% +basically what that whole lecture, that +whole class is about. And then I bring + + align:start position:0% +whole class is about. And then I bring + + + align:start position:0% +whole class is about. And then I bring +out this big box of ducks and I say and + + align:start position:0% +out this big box of ducks and I say and + + + align:start position:0% +out this big box of ducks and I say and +I say, um, well, uh, programming is + + align:start position:0% +I say, um, well, uh, programming is + + + align:start position:0% +I say, um, well, uh, programming is +actually kind of + + align:start position:0% +actually kind of + + + align:start position:0% +actually kind of +creative + + align:start position:0% +creative + + + align:start position:0% +creative +because the solution to a problem, I + + align:start position:0% +because the solution to a problem, I + + + align:start position:0% +because the solution to a problem, I +mean, you could brute force a bunch of + + align:start position:0% +mean, you could brute force a bunch of + + + align:start position:0% +mean, you could brute force a bunch of +things, but often times the solution to + + align:start position:0% +things, but often times the solution to + + + align:start position:0% +things, but often times the solution to +a debugging problem is just to take time + + align:start position:0% +a debugging problem is just to take time + + + align:start position:0% +a debugging problem is just to take time +away from it and then potentially + + align:start position:0% +away from it and then potentially + + + align:start position:0% +away from it and then potentially +explain exactly what your you think the + + align:start position:0% +explain exactly what your you think the + + + align:start position:0% +explain exactly what your you think the +code is doing to someone who knows + + align:start position:0% +code is doing to someone who knows + + + align:start position:0% +code is doing to someone who knows +absolutely nothing about programming. It + + align:start position:0% +absolutely nothing about programming. It + + + align:start position:0% +absolutely nothing about programming. It +could be you. Yes, I'm available. Or it + + align:start position:0% +could be you. Yes, I'm available. Or it + + + align:start position:0% +could be you. Yes, I'm available. Or it +could be a rubber duck. Oh, so this is + + align:start position:0% +could be a rubber duck. Oh, so this is + + + align:start position:0% +could be a rubber duck. Oh, so this is +called rubber ducky debugging. Oh, + + align:start position:0% +called rubber ducky debugging. Oh, + + + align:start position:0% +called rubber ducky debugging. Oh, +because uh it's an inanimate object that + + align:start position:0% +because uh it's an inanimate object that + + + align:start position:0% +because uh it's an inanimate object that +doesn't know anything about programming, + + align:start position:0% +doesn't know anything about programming, + + + align:start position:0% +doesn't know anything about programming, +right? And it forces you to scrutinize + + align:start position:0% +right? And it forces you to scrutinize + + + align:start position:0% +right? And it forces you to scrutinize +every single line of code that you + + align:start position:0% +every single line of code that you + + + align:start position:0% +every single line of code that you +wrote, even ones you think are correct. + + align:start position:0% +wrote, even ones you think are correct. + + + align:start position:0% +wrote, even ones you think are correct. +Um, most often it's the ones that are + + align:start position:0% +Um, most often it's the ones that are + + + align:start position:0% +Um, most often it's the ones that are +that you think are correct that kind of + + align:start position:0% +that you think are correct that kind of + + + align:start position:0% +that you think are correct that kind of +are are the issue. It's kind of like + + align:start position:0% +are are the issue. It's kind of like + + + align:start position:0% +are are the issue. It's kind of like +like where did I put my glasses, right? + + align:start position:0% +like where did I put my glasses, right? + + + align:start position:0% +like where did I put my glasses, right? +And you spend a long time looking for + + align:start position:0% +And you spend a long time looking for + + + align:start position:0% +And you spend a long time looking for +them and they're on top of your head. + + align:start position:0% +them and they're on top of your head. + + + align:start position:0% +them and they're on top of your head. +It's that exact feeling. It's like where + + align:start position:0% +It's that exact feeling. It's like where + + + align:start position:0% +It's that exact feeling. It's like where +is that error coming from? And it's + + align:start position:0% +is that error coming from? And it's + + + align:start position:0% +is that error coming from? And it's +going to be something super simple. So, + + align:start position:0% +going to be something super simple. So, + + + align:start position:0% +going to be something super simple. So, +the rubber duck is what um helps you + + align:start position:0% +the rubber duck is what um helps you + + + align:start position:0% +the rubber duck is what um helps you +figure that that problem out because + + align:start position:0% +figure that that problem out because + + + align:start position:0% +figure that that problem out because +you're explaining it in very grave + + align:start position:0% +you're explaining it in very grave + + + align:start position:0% +you're explaining it in very grave +detail to something that doesn't know. + + align:start position:0% +detail to something that doesn't know. + + + align:start position:0% +detail to something that doesn't know. +And if ducks are not your thing, there + + align:start position:0% +And if ducks are not your thing, there + + + align:start position:0% +And if ducks are not your thing, there +are frogs. Oh, and the pig pigs, of + + align:start position:0% +are frogs. Oh, and the pig pigs, of + + + align:start position:0% +are frogs. Oh, and the pig pigs, of +course. Of course. Or friends, you want + + align:start position:0% +course. Of course. Or friends, you want + + + align:start position:0% +course. Of course. Or friends, you want +to explain it to them. But friends can + + align:start position:0% +to explain it to them. But friends can + + + align:start position:0% +to explain it to them. But friends can +be judgy. Friends can be judgy. Yes. So, + + align:start position:0% +be judgy. Friends can be judgy. Yes. So, + + + align:start position:0% +be judgy. Friends can be judgy. Yes. So, +I used to explain my code to my son when + + align:start position:0% +I used to explain my code to my son when + + + align:start position:0% +I used to explain my code to my son when +he was one. Yeah. Yeah. When I had + + align:start position:0% +he was one. Yeah. Yeah. When I had + + + align:start position:0% +he was one. Yeah. Yeah. When I had +issues cuz he doesn't know anything + + align:start position:0% +issues cuz he doesn't know anything + + + align:start position:0% +issues cuz he doesn't know anything +about programming, right? And so it's + + align:start position:0% +about programming, right? And so it's + + + align:start position:0% +about programming, right? And so it's +the act of talking it through. But you + + align:start position:0% +the act of talking it through. But you + + + align:start position:0% +the act of talking it through. But you +said it has to be in great detail. Yes. + + align:start position:0% +said it has to be in great detail. Yes. + + + align:start position:0% +said it has to be in great detail. Yes. +You can't skip because that's when cuz + + align:start position:0% +You can't skip because that's when cuz + + + align:start position:0% +You can't skip because that's when cuz +you already like clearly your code is + + align:start position:0% +you already like clearly your code is + + + align:start position:0% +you already like clearly your code is +wrong + + align:start position:0% +wrong + + + align:start position:0% +wrong +because of you. And and so don't skip + + align:start position:0% +because of you. And and so don't skip + + + align:start position:0% +because of you. And and so don't skip +any details. Right. That's I feel like + + align:start position:0% +any details. Right. That's I feel like + + + align:start position:0% +any details. Right. That's I feel like +this very much like life outside of + + align:start position:0% +this very much like life outside of + + + align:start position:0% +this very much like life outside of +academia. like you 90% of the time the + + align:start position:0% +academia. like you 90% of the time the + + + align:start position:0% +academia. like you 90% of the time the +problem is probably you you know and + + align:start position:0% +problem is probably you you know and + + + align:start position:0% +problem is probably you you know and +it's like you have to figure out how to + + align:start position:0% +it's like you have to figure out how to + + + align:start position:0% +it's like you have to figure out how to +interact in the world or with others. So + + align:start position:0% +interact in the world or with others. So + + + align:start position:0% +interact in the world or with others. So +I brought all this all these ducks a + + align:start position:0% +I brought all this all these ducks a + + + align:start position:0% +I brought all this all these ducks a +wide variety. So now I have a a question + + align:start position:0% +wide variety. So now I have a a question + + + align:start position:0% +wide variety. So now I have a a question +for you. Which duck would you like to + + align:start position:0% +for you. Which duck would you like to + + + align:start position:0% +for you. Which duck would you like to +keep? This is a hidden personality test. + + align:start position:0% +keep? This is a hidden personality test. + + + align:start position:0% +keep? This is a hidden personality test. +Oh + + align:start position:0% +Oh + + + align:start position:0% +Oh +we'll probably have to cut this because + + align:start position:0% +we'll probably have to cut this because + + + align:start position:0% +we'll probably have to cut this because +it might take a long time. Um I would um + + align:start position:0% +it might take a long time. Um I would um + + + align:start position:0% +it might take a long time. Um I would um +this guy. This guy. Yeah. He's a little + + align:start position:0% +this guy. This guy. Yeah. He's a little + + + align:start position:0% +this guy. This guy. Yeah. He's a little +bit offbeat. Yeah. + + align:start position:0% +bit offbeat. Yeah. + + + align:start position:0% +bit offbeat. Yeah. +Um, you know, + + align:start position:0% +Um, you know, + + + align:start position:0% +Um, you know, +eye-catching and I feel like I could + + align:start position:0% +eye-catching and I feel like I could + + + align:start position:0% +eye-catching and I feel like I could +explain stuff to him. I get to keep him. + + align:start position:0% +explain stuff to him. I get to keep him. + + + align:start position:0% +explain stuff to him. I get to keep him. +Yeah, of course. Thank you. That's so + + align:start position:0% +Yeah, of course. Thank you. That's so + + + align:start position:0% +Yeah, of course. Thank you. That's so +great. You put one for the set as well. + + align:start position:0% +great. You put one for the set as well. + + + align:start position:0% +great. You put one for the set as well. +Really? Oh gosh. Does someone from the + + align:start position:0% +Really? Oh gosh. Does someone from the + + + align:start position:0% +Really? Oh gosh. Does someone from the +crew want to like pick a duck for the + + align:start position:0% +crew want to like pick a duck for the + + + align:start position:0% +crew want to like pick a duck for the +set? You took the one I would have + + align:start position:0% +set? You took the one I would have + + + align:start position:0% +set? You took the one I would have +picked. Oh, no. + + align:start position:0% +picked. Oh, no. + + + align:start position:0% +picked. Oh, no. +All right, then. Um, there's another + + align:start position:0% +All right, then. Um, there's another + + + align:start position:0% +All right, then. Um, there's another +mohawk guy right over there. Yeah. Yeah, + + align:start position:0% +mohawk guy right over there. Yeah. Yeah, + + + align:start position:0% +mohawk guy right over there. Yeah. Yeah, +we'll go two mohawks. There you go. + + align:start position:0% +we'll go two mohawks. There you go. + + + align:start position:0% +we'll go two mohawks. There you go. +Thank you. Yeah, of course. What a gift. + + align:start position:0% +Thank you. Yeah, of course. What a gift. + + + align:start position:0% +Thank you. Yeah, of course. What a gift. +So, you can use it for programming if + + align:start position:0% +So, you can use it for programming if + + + align:start position:0% +So, you can use it for programming if +you decide to start or as you said in + + align:start position:0% +you decide to start or as you said in + + + align:start position:0% +you decide to start or as you said in +even in your day-to-day life, you can if + + align:start position:0% +even in your day-to-day life, you can if + + + align:start position:0% +even in your day-to-day life, you can if +you just explain the problem to Yes. You + + align:start position:0% +you just explain the problem to Yes. You + + + align:start position:0% +you just explain the problem to Yes. You +know, something that doesn't judge or + + align:start position:0% +know, something that doesn't judge or + + + align:start position:0% +know, something that doesn't judge or +Yeah. Um this idea of taking a break + + align:start position:0% +Yeah. Um this idea of taking a break + + + align:start position:0% +Yeah. Um this idea of taking a break +like the process of programming itself + + align:start position:0% +like the process of programming itself + + + align:start position:0% +like the process of programming itself +seems quite intense. There's like an + + align:start position:0% +seems quite intense. There's like an + + + align:start position:0% +seems quite intense. There's like an +image in popular culture of like a + + align:start position:0% +image in popular culture of like a + + + align:start position:0% +image in popular culture of like a +person working alone in the dark like + + align:start position:0% +person working alone in the dark like + + + align:start position:0% +person working alone in the dark like +with a hoodie and like tap tap tap. um + + align:start position:0% +with a hoodie and like tap tap tap. um + + + align:start position:0% +with a hoodie and like tap tap tap. um +for hours on end. Like that sounds + + align:start position:0% +for hours on end. Like that sounds + + + align:start position:0% +for hours on end. Like that sounds +intense. Um so there's two pieces like + + align:start position:0% +intense. Um so there's two pieces like + + + align:start position:0% +intense. Um so there's two pieces like +is that accurate and two like do people + + align:start position:0% +is that accurate and two like do people + + + align:start position:0% +is that accurate and two like do people +work in isolation like that or is it + + align:start position:0% +work in isolation like that or is it + + + align:start position:0% +work in isolation like that or is it +more collaborative? Um so I tend to + + align:start position:0% +more collaborative? Um so I tend to + + + align:start position:0% +more collaborative? Um so I tend to +encourage collaboration. Okay. Uh I have + + align:start position:0% +encourage collaboration. Okay. Uh I have + + + align:start position:0% +encourage collaboration. Okay. Uh I have +certainly put a hoodie on and the hood + + align:start position:0% +certainly put a hoodie on and the hood + + + align:start position:0% +certainly put a hoodie on and the hood +on in the past just like a leave me + + align:start position:0% +on in the past just like a leave me + + + align:start position:0% +on in the past just like a leave me +alone kind of state. Uh mostly for you + + align:start position:0% +alone kind of state. Uh mostly for you + + + align:start position:0% +alone kind of state. Uh mostly for you +know homework and things like that. But + + align:start position:0% +know homework and things like that. But + + + align:start position:0% +know homework and things like that. But +I for for students learning to program I + + align:start position:0% +I for for students learning to program I + + + align:start position:0% +I for for students learning to program I +definitely encourage collaboration + + align:start position:0% +definitely encourage collaboration + + + align:start position:0% +definitely encourage collaboration +because it's when you talk to somebody + + align:start position:0% +because it's when you talk to somebody + + + align:start position:0% +because it's when you talk to somebody +else you kind of see their viewpoint and + + align:start position:0% +else you kind of see their viewpoint and + + + align:start position:0% +else you kind of see their viewpoint and +in programming I know I talked about + + align:start position:0% +in programming I know I talked about + + + align:start position:0% +in programming I know I talked about +like an algorithm but for you know for a + + align:start position:0% +like an algorithm but for you know for a + + + align:start position:0% +like an algorithm but for you know for a +particular algorithm or even just to + + align:start position:0% +particular algorithm or even just to + + + align:start position:0% +particular algorithm or even just to +solve a specific problem there's a ton + + align:start position:0% +solve a specific problem there's a ton + + + align:start position:0% +solve a specific problem there's a ton +of ways to solve it. So I learn from in + + align:start position:0% +of ways to solve it. So I learn from in + + + align:start position:0% +of ways to solve it. So I learn from in +the classroom when students when I ask + + align:start position:0% +the classroom when students when I ask + + + align:start position:0% +the classroom when students when I ask +students for how did they solve a + + align:start position:0% +students for how did they solve a + + + align:start position:0% +students for how did they solve a +particular problem after I give them + + align:start position:0% +particular problem after I give them + + + align:start position:0% +particular problem after I give them +some time to think about it they have so + + align:start position:0% +some time to think about it they have so + + + align:start position:0% +some time to think about it they have so +many different approaches to it that I + + align:start position:0% +many different approaches to it that I + + + align:start position:0% +many different approaches to it that I +would never have thought of and it's + + align:start position:0% +would never have thought of and it's + + + align:start position:0% +would never have thought of and it's +important for students to see all these + + align:start position:0% +important for students to see all these + + + align:start position:0% +important for students to see all these +different approaches because my way + + align:start position:0% +different approaches because my way + + + align:start position:0% +different approaches because my way +might not be the way that they think uh + + align:start position:0% +might not be the way that they think uh + + + align:start position:0% +might not be the way that they think uh +to approach the problem. So I encourage + + align:start position:0% +to approach the problem. So I encourage + + + align:start position:0% +to approach the problem. So I encourage +kind of working together especially as + + align:start position:0% +kind of working together especially as + + + align:start position:0% +kind of working together especially as +you're learning now after you find your + + align:start position:0% +you're learning now after you find your + + + align:start position:0% +you're learning now after you find your +groove maybe it's you know not necessary + + align:start position:0% +groove maybe it's you know not necessary + + + align:start position:0% +groove maybe it's you know not necessary +but yeah as an outsider to this I didn't + + align:start position:0% +but yeah as an outsider to this I didn't + + + align:start position:0% +but yeah as an outsider to this I didn't +realize there was such room for + + align:start position:0% +realize there was such room for + + + align:start position:0% +realize there was such room for +divergent thinking so that's really + + align:start position:0% +divergent thinking so that's really + + + align:start position:0% +divergent thinking so that's really +cool. Yeah, but the taking a break. So, + + align:start position:0% +cool. Yeah, but the taking a break. So, + + + align:start position:0% +cool. Yeah, but the taking a break. So, +especially at a place like MIT, like I + + align:start position:0% +especially at a place like MIT, like I + + + align:start position:0% +especially at a place like MIT, like I +don't I don't know if like taking a + + align:start position:0% +don't I don't know if like taking a + + + align:start position:0% +don't I don't know if like taking a +break is on the menu really. Um, but it + + align:start position:0% +break is on the menu really. Um, but it + + + align:start position:0% +break is on the menu really. Um, but it +should be. I'm guessing it should be. + + align:start position:0% +should be. I'm guessing it should be. + + + align:start position:0% +should be. I'm guessing it should be. +Yeah. And then I'm wondering if you can + + align:start position:0% +Yeah. And then I'm wondering if you can + + + align:start position:0% +Yeah. And then I'm wondering if you can +talk to us about like the thing you + + align:start position:0% +talk to us about like the thing you + + + align:start position:0% +talk to us about like the thing you +created in the world to help people take + + align:start position:0% +created in the world to help people take + + + align:start position:0% +created in the world to help people take +a break and why it's important. Sure. + + align:start position:0% +a break and why it's important. Sure. + + + align:start position:0% +a break and why it's important. Sure. +So, this was a project uh for I don't + + align:start position:0% +So, this was a project uh for I don't + + + align:start position:0% +So, this was a project uh for I don't +know. I just had an idea. I was like, + + align:start position:0% +know. I just had an idea. I was like, + + + align:start position:0% +know. I just had an idea. I was like, +let me just make a coloring book. um + + align:start position:0% +let me just make a coloring book. um + + + align:start position:0% +let me just make a coloring book. um +like you know one of those uh coloring + + align:start position:0% +like you know one of those uh coloring + + + align:start position:0% +like you know one of those uh coloring +books that you just kind of doodle in + + align:start position:0% +books that you just kind of doodle in + + + align:start position:0% +books that you just kind of doodle in +into. And I thought let me just make it + + align:start position:0% +into. And I thought let me just make it + + + align:start position:0% +into. And I thought let me just make it +um computer science themed. And so each + + align:start position:0% +um computer science themed. And so each + + + align:start position:0% +um computer science themed. And so each +one of these is you know like here's a + + align:start position:0% +one of these is you know like here's a + + + align:start position:0% +one of these is you know like here's a +circuit and it's like here's a network + + align:start position:0% +circuit and it's like here's a network + + + align:start position:0% +circuit and it's like here's a network +right of connected people and then + + align:start position:0% +right of connected people and then + + + align:start position:0% +right of connected people and then +here's a like a matrix kind of thing + + align:start position:0% +here's a like a matrix kind of thing + + + align:start position:0% +here's a like a matrix kind of thing +right with bits. + + align:start position:0% +right with bits. + + + align:start position:0% +right with bits. +So uh it was just kind of all these + + align:start position:0% +So uh it was just kind of all these + + + align:start position:0% +So uh it was just kind of all these +ideas from uh computer science and the + + align:start position:0% +ideas from uh computer science and the + + + align:start position:0% +ideas from uh computer science and the +hope is that if you are stuck and you + + align:start position:0% +hope is that if you are stuck and you + + + align:start position:0% +hope is that if you are stuck and you +don't have a duck right then you can + + align:start position:0% +don't have a duck right then you can + + + align:start position:0% +don't have a duck right then you can +take a coloring book doesn't have to be + + align:start position:0% +take a coloring book doesn't have to be + + + align:start position:0% +take a coloring book doesn't have to be +this one but just something that uh + + align:start position:0% +this one but just something that uh + + + align:start position:0% +this one but just something that uh +gives your brain a break but it's this + + align:start position:0% +gives your brain a break but it's this + + + align:start position:0% +gives your brain a break but it's this +idea of mind wandering and this is an + + align:start position:0% +idea of mind wandering and this is an + + + align:start position:0% +idea of mind wandering and this is an +idea from uh psychology where mind + + align:start position:0% +idea from uh psychology where mind + + + align:start position:0% +idea from uh psychology where mind +wandering is not bad like if you're + + align:start position:0% +wandering is not bad like if you're + + + align:start position:0% +wandering is not bad like if you're +folding laundry right you're doing a + + align:start position:0% +folding laundry right you're doing a + + + align:start position:0% +folding laundry right you're doing a +very repetitive task + + align:start position:0% +very repetitive task + + + align:start position:0% +very repetitive task +your brain doesn't have to super focus + + align:start position:0% +your brain doesn't have to super focus + + + align:start position:0% +your brain doesn't have to super focus +on it. And so that's when inspiration + + align:start position:0% +on it. And so that's when inspiration + + + align:start position:0% +on it. And so that's when inspiration +comes because you're kind of + + align:start position:0% +comes because you're kind of + + + align:start position:0% +comes because you're kind of +subconsciously thinking about other + + align:start position:0% +subconsciously thinking about other + + + align:start position:0% +subconsciously thinking about other +things, maybe problems that you have or, + + align:start position:0% +things, maybe problems that you have or, + + + align:start position:0% +things, maybe problems that you have or, +you know, things that you're worried + + align:start position:0% +you know, things that you're worried + + + align:start position:0% +you know, things that you're worried +about. And that's kind of when solutions + + align:start position:0% +about. And that's kind of when solutions + + + align:start position:0% +about. And that's kind of when solutions +come. Just like, you know, when you're + + align:start position:0% +come. Just like, you know, when you're + + + align:start position:0% +come. Just like, you know, when you're +taking a shower, that's mind wandering + + align:start position:0% +taking a shower, that's mind wandering + + + align:start position:0% +taking a shower, that's mind wandering +as well because you're doing a test that + + align:start position:0% +as well because you're doing a test that + + + align:start position:0% +as well because you're doing a test that +you already know how to do. You don't + + align:start position:0% +you already know how to do. You don't + + + align:start position:0% +you already know how to do. You don't +need to dedicate any thought to it. So + + align:start position:0% +need to dedicate any thought to it. So + + + align:start position:0% +need to dedicate any thought to it. So +your brain kind of dedicates thought to + + align:start position:0% +your brain kind of dedicates thought to + + + align:start position:0% +your brain kind of dedicates thought to +other things that um might be worrying + + align:start position:0% +other things that um might be worrying + + + align:start position:0% +other things that um might be worrying +you or on your mind. That's great that + + align:start position:0% +you or on your mind. That's great that + + + align:start position:0% +you or on your mind. That's great that +you've created that. Do you feel like + + align:start position:0% +you've created that. Do you feel like + + + align:start position:0% +you've created that. Do you feel like +programming + + align:start position:0% +programming + + + align:start position:0% +programming +is like what's the percentage of logic + + align:start position:0% +is like what's the percentage of logic + + + align:start position:0% +is like what's the percentage of logic +to creativity when it comes to + + align:start position:0% +to creativity when it comes to + + + align:start position:0% +to creativity when it comes to +programming? Are we like 50/50, 8020? + + align:start position:0% +programming? Are we like 50/50, 8020? + + + align:start position:0% +programming? Are we like 50/50, 8020? +Interesting. 6040 + + align:start position:0% +Interesting. 6040 + + + align:start position:0% +Interesting. 6040 +maybe 50/50 I would say. I think + + align:start position:0% +maybe 50/50 I would say. I think + + + align:start position:0% +maybe 50/50 I would say. I think +creativity comes into the process at all + + align:start position:0% +creativity comes into the process at all + + + align:start position:0% +creativity comes into the process at all +the different levels. So when you're + + align:start position:0% +the different levels. So when you're + + + align:start position:0% +the different levels. So when you're +coming up with a problem or something + + align:start position:0% +coming up with a problem or something + + + align:start position:0% +coming up with a problem or something +that you want to solve using + + align:start position:0% +that you want to solve using + + + align:start position:0% +that you want to solve using +programming, right, you have to be + + align:start position:0% +programming, right, you have to be + + + align:start position:0% +programming, right, you have to be +creative like right. Um so just coming + + align:start position:0% +creative like right. Um so just coming + + + align:start position:0% +creative like right. Um so just coming +up with that is mostly is creativity + + align:start position:0% +up with that is mostly is creativity + + + align:start position:0% +up with that is mostly is creativity +when you're deciding how to solve the + + align:start position:0% +when you're deciding how to solve the + + + align:start position:0% +when you're deciding how to solve the +problem or how to uh how to write the + + align:start position:0% +problem or how to uh how to write the + + + align:start position:0% +problem or how to uh how to write the +code sort of maybe what algorithm to use + + align:start position:0% +code sort of maybe what algorithm to use + + + align:start position:0% +code sort of maybe what algorithm to use +or how to structure it or like what + + align:start position:0% +or how to structure it or like what + + + align:start position:0% +or how to structure it or like what +pieces to use and where. um that + + align:start position:0% +pieces to use and where. um that + + + align:start position:0% +pieces to use and where. um that +requires some creativity potentially, + + align:start position:0% +requires some creativity potentially, + + + align:start position:0% +requires some creativity potentially, +you know, putting things together that + + align:start position:0% +you know, putting things together that + + + align:start position:0% +you know, putting things together that +you might not have put before, you know, + + align:start position:0% +you might not have put before, you know, + + + align:start position:0% +you might not have put before, you know, +pieces of uh uh programming concepts + + align:start position:0% +pieces of uh uh programming concepts + + + align:start position:0% +pieces of uh uh programming concepts +together that you might not have put + + align:start position:0% +together that you might not have put + + + align:start position:0% +together that you might not have put +before. And then you're obviously going + + align:start position:0% +before. And then you're obviously going + + + align:start position:0% +before. And then you're obviously going +to uh run into an error after you write + + align:start position:0% +to uh run into an error after you write + + + align:start position:0% +to uh run into an error after you write +the code the first time. And so then + + align:start position:0% +the code the first time. And so then + + + align:start position:0% +the code the first time. And so then +tons of creativity comes into play + + align:start position:0% +tons of creativity comes into play + + + align:start position:0% +tons of creativity comes into play +there. Uh but you know, drawing or + + align:start position:0% +there. Uh but you know, drawing or + + + align:start position:0% +there. Uh but you know, drawing or +talking to a duck. Um, I'm liking + + align:start position:0% +talking to a duck. Um, I'm liking + + + align:start position:0% +talking to a duck. Um, I'm liking +programming more and more, I have to + + align:start position:0% +programming more and more, I have to + + + align:start position:0% +programming more and more, I have to +say. I know once you're programming, + + align:start position:0% +say. I know once you're programming, + + + align:start position:0% +say. I know once you're programming, +it's kind of like reading a really good + + align:start position:0% +it's kind of like reading a really good + + + align:start position:0% +it's kind of like reading a really good +book. Like, you're in this zen space + + align:start position:0% +book. Like, you're in this zen space + + + align:start position:0% +book. Like, you're in this zen space +where you're just like, "Yeah, this is + + align:start position:0% +where you're just like, "Yeah, this is + + + align:start position:0% +where you're just like, "Yeah, this is +working." Like, I totally see where I'm + + align:start position:0% +working." Like, I totally see where I'm + + + align:start position:0% +working." Like, I totally see where I'm +where this is going. Like, I know what I + + align:start position:0% +where this is going. Like, I know what I + + + align:start position:0% +where this is going. Like, I know what I +want to write next, you know? Like, the + + align:start position:0% +want to write next, you know? Like, the + + + align:start position:0% +want to write next, you know? Like, the +code just kind of fits together. So, + + align:start position:0% +code just kind of fits together. So, + + + align:start position:0% +code just kind of fits together. So, +just like being in a good book is is + + align:start position:0% +just like being in a good book is is + + + align:start position:0% +just like being in a good book is is +awesome. Wow. And then the more you + + align:start position:0% +awesome. Wow. And then the more you + + + align:start position:0% +awesome. Wow. And then the more you +program, the more you want to program + + align:start position:0% +program, the more you want to program + + + align:start position:0% +program, the more you want to program +cuz you're just gaining these skills + + align:start position:0% +cuz you're just gaining these skills + + + align:start position:0% +cuz you're just gaining these skills +along the way. So, it's like you're like + + align:start position:0% +along the way. So, it's like you're like + + + align:start position:0% +along the way. So, it's like you're like +I play video games, so you know, you're + + align:start position:0% +I play video games, so you know, you're + + + align:start position:0% +I play video games, so you know, you're +just constantly like looking for new + + align:start position:0% +just constantly like looking for new + + + align:start position:0% +just constantly like looking for new +ways to level up, but there's no cap. + + align:start position:0% +ways to level up, but there's no cap. + + + align:start position:0% +ways to level up, but there's no cap. +It's uh really fascinating because + + align:start position:0% +It's uh really fascinating because + + + align:start position:0% +It's uh really fascinating because +unlike video games, most of them like + + align:start position:0% +unlike video games, most of them like + + + align:start position:0% +unlike video games, most of them like +you could use open-source + + align:start position:0% +you could use open-source + + + align:start position:0% +you could use open-source +um coding languages and financial + + align:start position:0% +um coding languages and financial + + + align:start position:0% +um coding languages and financial +barriers don't come into play to get + + align:start position:0% +barriers don't come into play to get + + + align:start position:0% +barriers don't come into play to get +that area for growth and that like that + + align:start position:0% +that area for growth and that like that + + + align:start position:0% +that area for growth and that like that +dopamine hit of like leveling up, + + align:start position:0% +dopamine hit of like leveling up, + + + align:start position:0% +dopamine hit of like leveling up, +increasing your skills. It's just Yeah, + + align:start position:0% +increasing your skills. It's just Yeah, + + + align:start position:0% +increasing your skills. It's just Yeah, +it's just kind of a different Like you + + align:start position:0% +it's just kind of a different Like you + + + align:start position:0% +it's just kind of a different Like you +said, it's a growth mindset, right? It's + + align:start position:0% +said, it's a growth mindset, right? It's + + + align:start position:0% +said, it's a growth mindset, right? It's +a different way of of It's a different + + align:start position:0% +a different way of of It's a different + + + align:start position:0% +a different way of of It's a different +fun. It's a different fun. It's a + + align:start position:0% +fun. It's a different fun. It's a + + + align:start position:0% +fun. It's a different fun. It's a +different fun. I I'm like more and more + + align:start position:0% +different fun. I I'm like more and more + + + align:start position:0% +different fun. I I'm like more and more +I'm like maybe I want to try this one. + + align:start position:0% +I'm like maybe I want to try this one. + + + align:start position:0% +I'm like maybe I want to try this one. +Well, oh, there's a book right here. + + align:start position:0% +Well, oh, there's a book right here. + + + align:start position:0% +Well, oh, there's a book right here. +Get programming. Learn to code with + + align:start position:0% +Get programming. Learn to code with + + + align:start position:0% +Get programming. Learn to code with +Python. Yeah. So, this I wrote a while + + align:start position:0% +Python. Yeah. So, this I wrote a while + + + align:start position:0% +Python. Yeah. So, this I wrote a while +ago. + + align:start position:0% +ago. + + + align:start position:0% +ago. +Um, it's a book made lots of books or + + align:start position:0% +Um, it's a book made lots of books or + + + align:start position:0% +Um, it's a book made lots of books or +lots of things claim to be for + + align:start position:0% +lots of things claim to be for + + + align:start position:0% +lots of things claim to be for +beginners, but I wanted to write + + align:start position:0% +beginners, but I wanted to write + + + align:start position:0% +beginners, but I wanted to write +something that is actually for people + + align:start position:0% +something that is actually for people + + + align:start position:0% +something that is actually for people +who have never programmed before. So, I + + align:start position:0% +who have never programmed before. So, I + + + align:start position:0% +who have never programmed before. So, I +think we don't even get into writing + + align:start position:0% +think we don't even get into writing + + + align:start position:0% +think we don't even get into writing +code to like chapter 7 or something like + + align:start position:0% +code to like chapter 7 or something like + + + align:start position:0% +code to like chapter 7 or something like +that. It's mostly kind of just setting + + align:start position:0% +that. It's mostly kind of just setting + + + align:start position:0% +that. It's mostly kind of just setting +up motivation, but not not boring like I + + align:start position:0% +up motivation, but not not boring like I + + + align:start position:0% +up motivation, but not not boring like I +wanted it to re read like a novel, + + align:start position:0% +wanted it to re read like a novel, + + + align:start position:0% +wanted it to re read like a novel, +right? Like you're just like, "Oh, I'm + + align:start position:0% +right? Like you're just like, "Oh, I'm + + + align:start position:0% +right? Like you're just like, "Oh, I'm +just following along." Um, so if you + + align:start position:0% +just following along." Um, so if you + + + align:start position:0% +just following along." Um, so if you +want to start, you could also, you know, + + align:start position:0% +want to start, you could also, you know, + + + align:start position:0% +want to start, you could also, you know, +you could try this book. You can keep + + align:start position:0% +you could try this book. You can keep + + + align:start position:0% +you could try this book. You can keep +this hot. Oh my gosh. I have to tell you + + align:start position:0% +this hot. Oh my gosh. I have to tell you + + + align:start position:0% +this hot. Oh my gosh. I have to tell you +a secret. Yes. So, I requested this + + align:start position:0% +a secret. Yes. So, I requested this + + + align:start position:0% +a secret. Yes. So, I requested this +through interl loan at my home library. + + align:start position:0% +through interl loan at my home library. + + + align:start position:0% +through interl loan at my home library. +So, and I asked um one of my family + + align:start position:0% +So, and I asked um one of my family + + + align:start position:0% +So, and I asked um one of my family +members to pick it up and I was like, + + align:start position:0% +members to pick it up and I was like, + + + align:start position:0% +members to pick it up and I was like, +just so you know, it's really for me. + + align:start position:0% +just so you know, it's really for me. + + + align:start position:0% +just so you know, it's really for me. +Like, cuz they would be like, why is she + + align:start position:0% +Like, cuz they would be like, why is she + + + align:start position:0% +Like, cuz they would be like, why is she +getting this book? This must be the + + align:start position:0% +getting this book? This must be the + + + align:start position:0% +getting this book? This must be the +wrong thing. I was like, it's not a + + align:start position:0% +wrong thing. I was like, it's not a + + + align:start position:0% +wrong thing. I was like, it's not a +mistake. Like, it's actually for me. And + + align:start position:0% +mistake. Like, it's actually for me. And + + + align:start position:0% +mistake. Like, it's actually for me. And +but I didn't really believe that, but + + align:start position:0% +but I didn't really believe that, but + + + align:start position:0% +but I didn't really believe that, but +now I feel like it is for me. Oh, great. + + align:start position:0% +now I feel like it is for me. Oh, great. + + + align:start position:0% +now I feel like it is for me. Oh, great. +Like I do want to read it now, learn. + + align:start position:0% +Like I do want to read it now, learn. + + + align:start position:0% +Like I do want to read it now, learn. +Yeah, anybody can can start for sure. + + align:start position:0% +Yeah, anybody can can start for sure. + + + align:start position:0% +Yeah, anybody can can start for sure. +Yeah, that's just great. Um, do you have + + align:start position:0% +Yeah, that's just great. Um, do you have + + + align:start position:0% +Yeah, that's just great. Um, do you have +any like hot tips for newbies who might + + align:start position:0% +any like hot tips for newbies who might + + + align:start position:0% +any like hot tips for newbies who might +um want to start or even people who are + + align:start position:0% +um want to start or even people who are + + + align:start position:0% +um want to start or even people who are +like deep into programming, deep into + + align:start position:0% +like deep into programming, deep into + + + align:start position:0% +like deep into programming, deep into +the hoodie already? Like things you're + + align:start position:0% +the hoodie already? Like things you're + + + align:start position:0% +the hoodie already? Like things you're +interested in reading or you think other + + align:start position:0% +interested in reading or you think other + + + align:start position:0% +interested in reading or you think other +people should view or listen to um to + + align:start position:0% +people should view or listen to um to + + + align:start position:0% +people should view or listen to um to +start or continue their journey? Mostly + + align:start position:0% +start or continue their journey? Mostly + + + align:start position:0% +start or continue their journey? Mostly +tip for mostly tips for newbies I would + + align:start position:0% +tip for mostly tips for newbies I would + + + align:start position:0% +tip for mostly tips for newbies I would +say. Okay. Um don't get discouraged. + + align:start position:0% +say. Okay. Um don't get discouraged. + + + align:start position:0% +say. Okay. Um don't get discouraged. +Learning curve is steep. Yeah. Okay. + + align:start position:0% +Learning curve is steep. Yeah. Okay. + + + align:start position:0% +Learning curve is steep. Yeah. Okay. +Yeah. It sucks. But can I text you when + + align:start position:0% +Yeah. It sucks. But can I text you when + + + align:start position:0% +Yeah. It sucks. But can I text you when +I Yes, you can text me. Thank you. If + + align:start position:0% +I Yes, you can text me. Thank you. If + + + align:start position:0% +I Yes, you can text me. Thank you. If +the duck doesn't work. If the duck + + align:start position:0% +the duck doesn't work. If the duck + + + align:start position:0% +the duck doesn't work. If the duck +doesn't work. Yeah. No, it's it's I + + align:start position:0% +doesn't work. Yeah. No, it's it's I + + + align:start position:0% +doesn't work. Yeah. No, it's it's I +mean, you're learning a new language. + + align:start position:0% +mean, you're learning a new language. + + + align:start position:0% +mean, you're learning a new language. +Like it's called a programming language, + + align:start position:0% +Like it's called a programming language, + + + align:start position:0% +Like it's called a programming language, +right? And it's basically learning a new + + align:start position:0% +right? And it's basically learning a new + + + align:start position:0% +right? And it's basically learning a new +way to write things that you already + + align:start position:0% +way to write things that you already + + + align:start position:0% +way to write things that you already +know how to do in or how to write in + + align:start position:0% +know how to do in or how to write in + + + align:start position:0% +know how to do in or how to write in +English. Yeah. You're just structuring + + align:start position:0% +English. Yeah. You're just structuring + + + align:start position:0% +English. Yeah. You're just structuring +it structuring it in a completely + + align:start position:0% +it structuring it in a completely + + + align:start position:0% +it structuring it in a completely +different way and a different language. + + align:start position:0% +different way and a different language. + + + align:start position:0% +different way and a different language. +So it the learning curve is steep. But + + align:start position:0% +So it the learning curve is steep. But + + + align:start position:0% +So it the learning curve is steep. But +don't get discouraged with Genai tools. + + align:start position:0% +don't get discouraged with Genai tools. + + + align:start position:0% +don't get discouraged with Genai tools. +Now though it's easy + + align:start position:0% +Now though it's easy + + + align:start position:0% +Now though it's easy +to get started right that's not from + + align:start position:0% +to get started right that's not from + + + align:start position:0% +to get started right that's not from +scratch. So like I mentioned earlier, if + + align:start position:0% +scratch. So like I mentioned earlier, if + + + align:start position:0% +scratch. So like I mentioned earlier, if +you're stuck on a problem, just ask + + align:start position:0% +you're stuck on a problem, just ask + + + align:start position:0% +you're stuck on a problem, just ask +prompt it to give you a solution and + + align:start position:0% +prompt it to give you a solution and + + + align:start position:0% +prompt it to give you a solution and +then work on the trust but verify + + align:start position:0% +then work on the trust but verify + + + align:start position:0% +then work on the trust but verify +uh piece where you'll actually get + + align:start position:0% +uh piece where you'll actually get + + + align:start position:0% +uh piece where you'll actually get +valuable experience debugging, right? + + align:start position:0% +valuable experience debugging, right? + + + align:start position:0% +valuable experience debugging, right? +Because you already start with a piece + + align:start position:0% +Because you already start with a piece + + + align:start position:0% +Because you already start with a piece +of code. So like the confidence level is + + align:start position:0% +of code. So like the confidence level is + + + align:start position:0% +of code. So like the confidence level is +already kind of there. You're like, + + align:start position:0% +already kind of there. You're like, + + + align:start position:0% +already kind of there. You're like, +okay, I'm not starting blank. And then + + align:start position:0% +okay, I'm not starting blank. And then + + + align:start position:0% +okay, I'm not starting blank. And then +you can, you know, try to fix it or + + align:start position:0% +you can, you know, try to fix it or + + + align:start position:0% +you can, you know, try to fix it or +agree that it works. And both are really + + align:start position:0% +agree that it works. And both are really + + + align:start position:0% +agree that it works. And both are really +valuable skills to to practice as + + align:start position:0% +valuable skills to to practice as + + + align:start position:0% +valuable skills to to practice as +beginner programmers. I love the idea of + + align:start position:0% +beginner programmers. I love the idea of + + + align:start position:0% +beginner programmers. I love the idea of +starting with code and practicing + + align:start position:0% +starting with code and practicing + + + align:start position:0% +starting with code and practicing +debugging. That feels like low stakes + + align:start position:0% +debugging. That feels like low stakes + + + align:start position:0% +debugging. That feels like low stakes +and doable. Totally. Yeah. Um, what have + + align:start position:0% +and doable. Totally. Yeah. Um, what have + + + align:start position:0% +and doable. Totally. Yeah. Um, what have +I not asked you that I should have asked + + align:start position:0% +I not asked you that I should have asked + + + align:start position:0% +I not asked you that I should have asked +you? I want to know what games. What + + align:start position:0% +you? I want to know what games. What + + + align:start position:0% +you? I want to know what games. What +games? What games you play? Oh my gosh. + + align:start position:0% +games? What games you play? Oh my gosh. + + + align:start position:0% +games? What games you play? Oh my gosh. +Like video games? Y I like driving a + + align:start position:0% +Like video games? Y I like driving a + + + align:start position:0% +Like video games? Y I like driving a +lot. So I drive in the real I do not. + + align:start position:0% +lot. So I drive in the real I do not. + + + align:start position:0% +lot. So I drive in the real I do not. +You said you don't like being stuck in + + align:start position:0% +You said you don't like being stuck in + + + align:start position:0% +You said you don't like being stuck in +traffic. No, I don't like being stuck. + + align:start position:0% +traffic. No, I don't like being stuck. + + + align:start position:0% +traffic. No, I don't like being stuck. +So, I like to drive. So, I also enjoy + + align:start position:0% +So, I like to drive. So, I also enjoy + + + align:start position:0% +So, I like to drive. So, I also enjoy +driving games. Okay. + + align:start position:0% +driving games. Okay. + + + align:start position:0% +driving games. Okay. +Not just around the track, but like + + align:start position:0% +Not just around the track, but like + + + align:start position:0% +Not just around the track, but like +through random cities and things like + + align:start position:0% +through random cities and things like + + + align:start position:0% +through random cities and things like +that. Escaping the police and you know, + + align:start position:0% +that. Escaping the police and you know, + + + align:start position:0% +that. Escaping the police and you know, +like the You have a whole other side to + + align:start position:0% +like the You have a whole other side to + + + align:start position:0% +like the You have a whole other side to +you. Me for speed. + + align:start position:0% +you. Me for speed. + + + align:start position:0% +you. Me for speed. +GTA played Need for Speed. Yeah. Yeah. I + + align:start position:0% +GTA played Need for Speed. Yeah. Yeah. I + + + align:start position:0% +GTA played Need for Speed. Yeah. Yeah. I +have the setup with the wheel and Yeah. + + align:start position:0% +have the setup with the wheel and Yeah. + + + align:start position:0% +have the setup with the wheel and Yeah. +Yeah. Oh, wow. Well, thank you so much + + align:start position:0% +Yeah. Oh, wow. Well, thank you so much + + + align:start position:0% +Yeah. Oh, wow. Well, thank you so much +for being here. I learned about myself. + + align:start position:0% +for being here. I learned about myself. + + + align:start position:0% +for being here. I learned about myself. +I learned about programming. I have a + + align:start position:0% +I learned about programming. I have a + + + align:start position:0% +I learned about programming. I have a +whole new world view on what is possible + + align:start position:0% +whole new world view on what is possible + + + align:start position:0% +whole new world view on what is possible +with and through programming. And that's + + align:start position:0% +with and through programming. And that's + + + align:start position:0% +with and through programming. And that's +just an incredible gift. And I'm so glad + + align:start position:0% +just an incredible gift. And I'm so glad + + + align:start position:0% +just an incredible gift. And I'm so glad +we get to share that with a lot of + + align:start position:0% +we get to share that with a lot of + + + align:start position:0% +we get to share that with a lot of +people who might also take that gift and + + align:start position:0% +people who might also take that gift and + + + align:start position:0% +people who might also take that gift and +run with it. So, thank you. That's + + align:start position:0% +run with it. So, thank you. That's + + + align:start position:0% +run with it. So, thank you. That's +awesome. Glad to hear. Thank you for the + + align:start position:0% +awesome. Glad to hear. Thank you for the + + + align:start position:0% +awesome. Glad to hear. Thank you for the +chat. This was awesome. And thank you + + align:start position:0% +chat. This was awesome. And thank you + + + align:start position:0% +chat. This was awesome. And thank you +for the duck. Yes. + + align:start position:0% + + + + align:start position:0% + +[Music] \ No newline at end of file diff --git a/peJUDjHJGb4.txt b/peJUDjHJGb4.txt new file mode 100644 index 0000000000000000000000000000000000000000..f7ae9296901d5697757be477aa49cb3b6ab4c144 --- /dev/null +++ b/peJUDjHJGb4.txt @@ -0,0 +1,851 @@ +align:start position:0% + +here I present a spherical distribution + + align:start position:0% +here I present a spherical distribution + + + align:start position:0% +here I present a spherical distribution +problem and how I went about finding an + + align:start position:0% +problem and how I went about finding an + + + align:start position:0% +problem and how I went about finding an +approximate solution in Mathematica + + align:start position:0% +approximate solution in Mathematica + + + align:start position:0% +approximate solution in Mathematica +if you observe light that passes through + + align:start position:0% +if you observe light that passes through + + + align:start position:0% +if you observe light that passes through +a translucent spherical object a + + align:start position:0% +a translucent spherical object a + + + align:start position:0% +a translucent spherical object a +radiation that is transmitted through a + + align:start position:0% +radiation that is transmitted through a + + + align:start position:0% +radiation that is transmitted through a +spherical attenuator the intensity is + + align:start position:0% +spherical attenuator the intensity is + + + align:start position:0% +spherical attenuator the intensity is +not evenly distributed the intensity of + + align:start position:0% +not evenly distributed the intensity of + + + align:start position:0% +not evenly distributed the intensity of +transmitted radiation is described by + + align:start position:0% +transmitted radiation is described by + + + align:start position:0% +transmitted radiation is described by +this exponential function where the + + align:start position:0% +this exponential function where the + + + align:start position:0% +this exponential function where the +intensity distribution is governed by + + align:start position:0% +intensity distribution is governed by + + + align:start position:0% +intensity distribution is governed by +the material thickness X and density + + align:start position:0% +the material thickness X and density + + + align:start position:0% +the material thickness X and density +lambda + + align:start position:0% + + + + align:start position:0% + +let's plot this function + + align:start position:0% + + + + align:start position:0% + +you can see that as the material + + align:start position:0% +you can see that as the material + + + align:start position:0% +you can see that as the material +thickness X increases the intensity of + + align:start position:0% +thickness X increases the intensity of + + + align:start position:0% +thickness X increases the intensity of +the transmitted radiation decreases + + align:start position:0% +the transmitted radiation decreases + + + align:start position:0% +the transmitted radiation decreases +exponentially let's make a function to + + align:start position:0% +exponentially let's make a function to + + + align:start position:0% +exponentially let's make a function to +model the transmitted radiation + + align:start position:0% +model the transmitted radiation + + + align:start position:0% +model the transmitted radiation +intensity in 3d in this module I defined + + align:start position:0% +intensity in 3d in this module I defined + + + align:start position:0% +intensity in 3d in this module I defined +I I naught and lambda to be local + + align:start position:0% +I I naught and lambda to be local + + + align:start position:0% +I I naught and lambda to be local +variables Z is the function for a + + align:start position:0% +variables Z is the function for a + + + align:start position:0% +variables Z is the function for a +hemisphere we want to look at the + + align:start position:0% +hemisphere we want to look at the + + + align:start position:0% +hemisphere we want to look at the +effects on a sphere but it's easier to + + align:start position:0% +effects on a sphere but it's easier to + + + align:start position:0% +effects on a sphere but it's easier to +work with the hemisphere so I multiplied + + align:start position:0% +work with the hemisphere so I multiplied + + + align:start position:0% +work with the hemisphere so I multiplied +the hemisphere by 2 and the function + + align:start position:0% +the hemisphere by 2 and the function + + + align:start position:0% +the hemisphere by 2 and the function +returns intensity as a function of x and + + align:start position:0% +returns intensity as a function of x and + + + align:start position:0% +returns intensity as a function of x and +y position where the xy-plane is the + + align:start position:0% +y position where the xy-plane is the + + + align:start position:0% +y position where the xy-plane is the +projection of the sphere let's have a + + align:start position:0% +projection of the sphere let's have a + + + align:start position:0% +projection of the sphere let's have a +look at the intensity distribution in 3d + + align:start position:0% +look at the intensity distribution in 3d + + + align:start position:0% +look at the intensity distribution in 3d +this plot shows us that the intensity at + + align:start position:0% +this plot shows us that the intensity at + + + align:start position:0% +this plot shows us that the intensity at +the edges of the projection is greater + + align:start position:0% +the edges of the projection is greater + + + align:start position:0% +the edges of the projection is greater +than the intensity in the middle of the + + align:start position:0% +than the intensity in the middle of the + + + align:start position:0% +than the intensity in the middle of the +projection it's a bit hard to visualize + + align:start position:0% +projection it's a bit hard to visualize + + + align:start position:0% +projection it's a bit hard to visualize +so here's another way to look at it + + align:start position:0% + + + + align:start position:0% + +you can see that the intensity is + + align:start position:0% +you can see that the intensity is + + + align:start position:0% +you can see that the intensity is +highest around the edges and lowest in + + align:start position:0% +highest around the edges and lowest in + + + align:start position:0% +highest around the edges and lowest in +the center of the projection I did this + + align:start position:0% +the center of the projection I did this + + + align:start position:0% +the center of the projection I did this +by making the arrow length a function of + + align:start position:0% +by making the arrow length a function of + + + align:start position:0% +by making the arrow length a function of +the intensity + + align:start position:0% + + + + align:start position:0% + +now let's see what happens when we + + align:start position:0% +now let's see what happens when we + + + align:start position:0% +now let's see what happens when we +replace lambda which was a constant with + + align:start position:0% +replace lambda which was a constant with + + + align:start position:0% +replace lambda which was a constant with +a function this means that we are + + align:start position:0% +a function this means that we are + + + align:start position:0% +a function this means that we are +changing the materials density as a + + align:start position:0% +changing the materials density as a + + + align:start position:0% +changing the materials density as a +function of the spheres radius I'm going + + align:start position:0% +function of the spheres radius I'm going + + + align:start position:0% +function of the spheres radius I'm going +to alter the intensity function I made + + align:start position:0% +to alter the intensity function I made + + + align:start position:0% +to alter the intensity function I made +before so that we can specify different + + align:start position:0% +before so that we can specify different + + + align:start position:0% +before so that we can specify different +functions for lambda + + align:start position:0% + + + + align:start position:0% + +here I'll show you three functions I + + align:start position:0% +here I'll show you three functions I + + + align:start position:0% +here I'll show you three functions I +tried out earlier for lambda to try and + + align:start position:0% +tried out earlier for lambda to try and + + + align:start position:0% +tried out earlier for lambda to try and +make the intensity constant there's a + + align:start position:0% +make the intensity constant there's a + + + align:start position:0% +make the intensity constant there's a +cosine function a nested sine function + + align:start position:0% +cosine function a nested sine function + + + align:start position:0% +cosine function a nested sine function +as suggested by professor Carter and a + + align:start position:0% +as suggested by professor Carter and a + + + align:start position:0% +as suggested by professor Carter and a +spherical Bessel function let's check + + align:start position:0% +spherical Bessel function let's check + + + align:start position:0% +spherical Bessel function let's check +that our function works on the lambda is + + align:start position:0% +that our function works on the lambda is + + + align:start position:0% +that our function works on the lambda is +a constant case we tried before + + align:start position:0% +a constant case we tried before + + + align:start position:0% +a constant case we tried before +okay good it works + + align:start position:0% +okay good it works + + + align:start position:0% +okay good it works +now let's look at our new density + + align:start position:0% +now let's look at our new density + + + align:start position:0% +now let's look at our new density +functions + + align:start position:0% + + + + align:start position:0% + +the first one is the cosine function you + + align:start position:0% +the first one is the cosine function you + + + align:start position:0% +the first one is the cosine function you +can see that the shape is not quite a + + align:start position:0% +can see that the shape is not quite a + + + align:start position:0% +can see that the shape is not quite a +hemisphere and now looks a bit closer to + + align:start position:0% +hemisphere and now looks a bit closer to + + + align:start position:0% +hemisphere and now looks a bit closer to +a cylinder next is the sine function it + + align:start position:0% +a cylinder next is the sine function it + + + align:start position:0% +a cylinder next is the sine function it +looks a lot like the cosine function + + align:start position:0% +looks a lot like the cosine function + + + align:start position:0% +looks a lot like the cosine function +more like a cylinder than a hemisphere + + align:start position:0% +more like a cylinder than a hemisphere + + + align:start position:0% +more like a cylinder than a hemisphere +and last is the Bessel function + + align:start position:0% + + + + align:start position:0% + +you + + align:start position:0% +you + + + align:start position:0% +you +it also looks a lot like design and + + align:start position:0% +it also looks a lot like design and + + + align:start position:0% +it also looks a lot like design and +cosine functions + + align:start position:0% + + + + align:start position:0% + +since the sine cosine and Bessel + + align:start position:0% +since the sine cosine and Bessel + + + align:start position:0% +since the sine cosine and Bessel +functions are very similar I'll plot + + align:start position:0% +functions are very similar I'll plot + + + align:start position:0% +functions are very similar I'll plot +them a different way so you can see them + + align:start position:0% +them a different way so you can see them + + + align:start position:0% +them a different way so you can see them +more clearly here the blue line is the + + align:start position:0% +more clearly here the blue line is the + + + align:start position:0% +more clearly here the blue line is the +Bessel function the red line is the + + align:start position:0% +Bessel function the red line is the + + + align:start position:0% +Bessel function the red line is the +cosine function and the yellow line is + + align:start position:0% +cosine function and the yellow line is + + + align:start position:0% +cosine function and the yellow line is +the nested sine function okay since it's + + align:start position:0% +the nested sine function okay since it's + + + align:start position:0% +the nested sine function okay since it's +hard to see from the 3d plots which of + + align:start position:0% +hard to see from the 3d plots which of + + + align:start position:0% +hard to see from the 3d plots which of +the density functions is closest to + + align:start position:0% +the density functions is closest to + + + align:start position:0% +the density functions is closest to +giving me constant intensity professor + + align:start position:0% +giving me constant intensity professor + + + align:start position:0% +giving me constant intensity professor +Carter suggested that I make a numerical + + align:start position:0% +Carter suggested that I make a numerical + + + align:start position:0% +Carter suggested that I make a numerical +error analysis if the intensity were + + align:start position:0% +error analysis if the intensity were + + + align:start position:0% +error analysis if the intensity were +constant we would get a cylinder in a 3d + + align:start position:0% +constant we would get a cylinder in a 3d + + + align:start position:0% +constant we would get a cylinder in a 3d +plot so I found the height of that + + align:start position:0% +plot so I found the height of that + + + align:start position:0% +plot so I found the height of that +theoretical cylinder by finding the + + align:start position:0% +theoretical cylinder by finding the + + + align:start position:0% +theoretical cylinder by finding the +minimum for each of the intensity + + align:start position:0% +minimum for each of the intensity + + + align:start position:0% +minimum for each of the intensity +functions then I subtracted the volume + + align:start position:0% +functions then I subtracted the volume + + + align:start position:0% +functions then I subtracted the volume +of the intensity from the volume of the + + align:start position:0% +of the intensity from the volume of the + + + align:start position:0% +of the intensity from the volume of the +theoretical cylinder and the square of + + align:start position:0% +theoretical cylinder and the square of + + + align:start position:0% +theoretical cylinder and the square of +this difference is the error here's a + + align:start position:0% +this difference is the error here's a + + + align:start position:0% +this difference is the error here's a +list of the errors but it will be easier + + align:start position:0% +list of the errors but it will be easier + + + align:start position:0% +list of the errors but it will be easier +to compare if I make a bar chart + + align:start position:0% + + + + align:start position:0% + +okay now you can clearly see which + + align:start position:0% +okay now you can clearly see which + + + align:start position:0% +okay now you can clearly see which +function is the winner when the density + + align:start position:0% +function is the winner when the density + + + align:start position:0% +function is the winner when the density +is constant the intensity is the + + align:start position:0% +is constant the intensity is the + + + align:start position:0% +is constant the intensity is the +furthest from being constant the sine + + align:start position:0% +furthest from being constant the sine + + + align:start position:0% +furthest from being constant the sine +and cosine functions are much closer to + + align:start position:0% +and cosine functions are much closer to + + + align:start position:0% +and cosine functions are much closer to +making the intensity constant but the + + align:start position:0% +making the intensity constant but the + + + align:start position:0% +making the intensity constant but the +spherical Bessel function definitely + + align:start position:0% +spherical Bessel function definitely + + + align:start position:0% +spherical Bessel function definitely +makes the most even intensity + + align:start position:0% +makes the most even intensity + + + align:start position:0% +makes the most even intensity +distribution there is no perfect + + align:start position:0% +distribution there is no perfect + + + align:start position:0% +distribution there is no perfect +solution because at the limit of the + + align:start position:0% +solution because at the limit of the + + + align:start position:0% +solution because at the limit of the +edge of the sphere the material + + align:start position:0% +edge of the sphere the material + + + align:start position:0% +edge of the sphere the material +thickness goes to zero and therefore the + + align:start position:0% +thickness goes to zero and therefore the + + + align:start position:0% +thickness goes to zero and therefore the +density function must go to infinity but + + align:start position:0% +density function must go to infinity but + + + align:start position:0% +density function must go to infinity but +it looks like the Bessel function makes + + align:start position:0% +it looks like the Bessel function makes + + + align:start position:0% +it looks like the Bessel function makes +a good approximation + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/pusPy4EDPC0.txt b/pusPy4EDPC0.txt new file mode 100644 index 0000000000000000000000000000000000000000..ce5fbabc383ec90a080235bb6f246777daf84358 --- /dev/null +++ b/pusPy4EDPC0.txt @@ -0,0 +1,15515 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a creative commons license + + align:start position:0% +a creative commons license + + + align:start position:0% +a creative commons license +your support will help mit + + align:start position:0% +your support will help mit + + + align:start position:0% +your support will help mit +opencourseware continue to offer high + + align:start position:0% +opencourseware continue to offer high + + + align:start position:0% +opencourseware continue to offer high +quality educational resources for free + + align:start position:0% +quality educational resources for free + + + align:start position:0% +quality educational resources for free +to make a donation or view additional + + align:start position:0% +to make a donation or view additional + + + align:start position:0% +to make a donation or view additional +materials from hundreds of mit courses + + align:start position:0% +materials from hundreds of mit courses + + + align:start position:0% +materials from hundreds of mit courses +visit mit open courseware at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +all right so let's get started + + align:start position:0% + + + + align:start position:0% + +so last time we were talking we talked + + align:start position:0% +so last time we were talking we talked + + + align:start position:0% +so last time we were talking we talked +about factorization in the effective + + align:start position:0% +about factorization in the effective + + + align:start position:0% +about factorization in the effective +theory and + + align:start position:0% +theory and + + + align:start position:0% +theory and +there is one type of factorization which + + align:start position:0% +there is one type of factorization which + + + align:start position:0% +there is one type of factorization which +is this hard clinical factorization that + + align:start position:0% +is this hard clinical factorization that + + + align:start position:0% +is this hard clinical factorization that +happened when the wilson ko which is a + + align:start position:0% +happened when the wilson ko which is a + + + align:start position:0% +happened when the wilson ko which is a +factorization between sort of the low + + align:start position:0% +factorization between sort of the low + + + align:start position:0% +factorization between sort of the low +energy physics described by the operator + + align:start position:0% +energy physics described by the operator + + + align:start position:0% +energy physics described by the operator +and the wilson coefficients + + align:start position:0% +and the wilson coefficients + + + align:start position:0% +and the wilson coefficients +and we decided we wanted to think about + + align:start position:0% +and we decided we wanted to think about + + + align:start position:0% +and we decided we wanted to think about +that in the following ways having + + align:start position:0% +that in the following ways having + + + align:start position:0% +that in the following ways having +convolutions between + + align:start position:0% +convolutions between + + + align:start position:0% +convolutions between +variables that appear in the wilson + + align:start position:0% +variables that appear in the wilson + + + align:start position:0% +variables that appear in the wilson +coefficients and variables that appear + + align:start position:0% +coefficients and variables that appear + + + align:start position:0% +coefficients and variables that appear +in the operator and the way that we can + + align:start position:0% +in the operator and the way that we can + + + align:start position:0% +in the operator and the way that we can +think about that is just what the most + + align:start position:0% +think about that is just what the most + + + align:start position:0% +think about that is just what the most +general possible thing is that we can + + align:start position:0% +general possible thing is that we can + + + align:start position:0% +general possible thing is that we can +write down for the wilson coefficients + + align:start position:0% +write down for the wilson coefficients + + + align:start position:0% +write down for the wilson coefficients +and of course it can depend on large + + align:start position:0% +and of course it can depend on large + + + align:start position:0% +and of course it can depend on large +momenta + + align:start position:0% +momenta + + + align:start position:0% +momenta +and so + + align:start position:0% +and so + + + align:start position:0% +and so +large momenta here includes the label + + align:start position:0% +large momenta here includes the label + + + align:start position:0% +large momenta here includes the label +operator + + align:start position:0% +operator + + + align:start position:0% + +so large momentum always show up in the + + align:start position:0% +so large momentum always show up in the + + + align:start position:0% +so large momentum always show up in the +wilson wilson coefficients + + align:start position:0% +wilson wilson coefficients + + + align:start position:0% +wilson wilson coefficients +and in this case that includes momenta + + align:start position:0% +and in this case that includes momenta + + + align:start position:0% +and in this case that includes momenta +that are the large component the lambda + + align:start position:0% +that are the large component the lambda + + + align:start position:0% +that are the large component the lambda +ordered lambda zero component of linear + + align:start position:0% +ordered lambda zero component of linear + + + align:start position:0% +ordered lambda zero component of linear +fields + + align:start position:0% + + + + align:start position:0% + +so this is hard linear factorization + + align:start position:0% + + + + align:start position:0% + +and it just comes out in a kind of + + align:start position:0% +and it just comes out in a kind of + + + align:start position:0% +and it just comes out in a kind of +natural standard way in this effective + + align:start position:0% +natural standard way in this effective + + + align:start position:0% +natural standard way in this effective +theory because + + align:start position:0% +theory because + + + align:start position:0% +theory because +we've set up the effective theory to + + align:start position:0% +we've set up the effective theory to + + + align:start position:0% +we've set up the effective theory to +have the right low energy degrees of + + align:start position:0% +have the right low energy degrees of + + + align:start position:0% +have the right low energy degrees of +freedom + + align:start position:0% +freedom + + + align:start position:0% +freedom +so even though it's a little more + + align:start position:0% +so even though it's a little more + + + align:start position:0% +so even though it's a little more +complicated than just a simple product + + align:start position:0% +complicated than just a simple product + + + align:start position:0% +complicated than just a simple product +we see sort of what the variables are + + align:start position:0% +we see sort of what the variables are + + + align:start position:0% +we see sort of what the variables are +that can connect the two things + + align:start position:0% +that can connect the two things + + + align:start position:0% +that can connect the two things +just by power counting essentially + + align:start position:0% +just by power counting essentially + + + align:start position:0% +just by power counting essentially +the large momentum are the + + align:start position:0% +the large momentum are the + + + align:start position:0% +the large momentum are the +ones that are + + align:start position:0% +ones that are + + + align:start position:0% +ones that are +order lambda to zero + + align:start position:0% +order lambda to zero + + + align:start position:0% +order lambda to zero +we can kind of do this generically if we + + align:start position:0% +we can kind of do this generically if we + + + align:start position:0% +we can kind of do this generically if we +recall the definition of our wilson line + + align:start position:0% + + + + align:start position:0% + +you can see how this would carry over to + + align:start position:0% +you can see how this would carry over to + + + align:start position:0% +you can see how this would carry over to +a generic case in the following way + + align:start position:0% + + + + align:start position:0% + +so that was + + align:start position:0% +so that was + + + align:start position:0% +so that was +one way of defining the wilson line + + align:start position:0% + + + + align:start position:0% + +and as an operator we had relations as + + align:start position:0% +and as an operator we had relations as + + + align:start position:0% +and as an operator we had relations as +well + + align:start position:0% + + + + align:start position:0% + +so we had + + align:start position:0% + + + + align:start position:0% + +this relation and in particular + + align:start position:0% +this relation and in particular + + + align:start position:0% +this relation and in particular +we could take this to any power + + align:start position:0% +we could take this to any power + + + align:start position:0% +we could take this to any power +and that just takes the p bar to any + + align:start position:0% +and that just takes the p bar to any + + + align:start position:0% +and that just takes the p bar to any +power + + align:start position:0% + + + + align:start position:0% + +like that + + align:start position:0% +like that + + + align:start position:0% +like that +so you can really think of this as given + + align:start position:0% +so you can really think of this as given + + + align:start position:0% +so you can really think of this as given +any function + + align:start position:0% +any function + + + align:start position:0% +any function +of + + align:start position:0% +of + + + align:start position:0% +of +this + + align:start position:0% +this + + + align:start position:0% +this +operator imbar.d + + align:start position:0% +operator imbar.d + + + align:start position:0% +operator imbar.d +you can always write that as a wilson + + align:start position:0% +you can always write that as a wilson + + + align:start position:0% +you can always write that as a wilson +line a function of p bar + + align:start position:0% +line a function of p bar + + + align:start position:0% +line a function of p bar +and a wilson line + + align:start position:0% + + + + align:start position:0% + +and what you want to do is you want to + + align:start position:0% +and what you want to do is you want to + + + align:start position:0% +and what you want to do is you want to +stick these wilson lines in the operator + + align:start position:0% +stick these wilson lines in the operator + + + align:start position:0% +stick these wilson lines in the operator +and you want to put this function in the + + align:start position:0% +and you want to put this function in the + + + align:start position:0% +and you want to put this function in the +wilson coefficient + + align:start position:0% +wilson coefficient + + + align:start position:0% +wilson coefficient +so you could think let me start with + + align:start position:0% +so you could think let me start with + + + align:start position:0% +so you could think let me start with +operators where i just + + align:start position:0% +operators where i just + + + align:start position:0% +operators where i just +i can throw in i and bar.ds because + + align:start position:0% +i can throw in i and bar.ds because + + + align:start position:0% +i can throw in i and bar.ds because +these guys are ordered lambda 0. these + + align:start position:0% +these guys are ordered lambda 0. these + + + align:start position:0% +these guys are ordered lambda 0. these +are the linear derivatives + + align:start position:0% +are the linear derivatives + + + align:start position:0% +are the linear derivatives +i just allowed to stick as many of those + + align:start position:0% +i just allowed to stick as many of those + + + align:start position:0% +i just allowed to stick as many of those +as i like in my operator + + align:start position:0% +as i like in my operator + + + align:start position:0% +as i like in my operator +but given that i put in any function of + + align:start position:0% +but given that i put in any function of + + + align:start position:0% +but given that i put in any function of +them i could always do this and the + + align:start position:0% +them i could always do this and the + + + align:start position:0% +them i could always do this and the +right way of thinking about it + + align:start position:0% +right way of thinking about it + + + align:start position:0% +right way of thinking about it +is that this should this is + + align:start position:0% +is that this should this is + + + align:start position:0% +is that this should this is +this function here is what your is + + align:start position:0% +this function here is what your is + + + align:start position:0% +this function here is what your is +determined by matching it's your wilson + + align:start position:0% +determined by matching it's your wilson + + + align:start position:0% +determined by matching it's your wilson +coefficient + + align:start position:0% +coefficient + + + align:start position:0% +coefficient +so + + align:start position:0% + + + + align:start position:0% + +and that's what we were effectively + + align:start position:0% +and that's what we were effectively + + + align:start position:0% +and that's what we were effectively +doing up here + + align:start position:0% +doing up here + + + align:start position:0% +doing up here +but this is in some sense a more general + + align:start position:0% +but this is in some sense a more general + + + align:start position:0% +but this is in some sense a more general +discussion you can see that even if you + + align:start position:0% +discussion you can see that even if you + + + align:start position:0% +discussion you can see that even if you +had multiple places in the operator + + align:start position:0% +had multiple places in the operator + + + align:start position:0% +had multiple places in the operator +where you could insert these derivatives + + align:start position:0% +where you could insert these derivatives + + + align:start position:0% +where you could insert these derivatives +then you would just do this and what + + align:start position:0% +then you would just do this and what + + + align:start position:0% +then you would just do this and what +would happen is at the end of the day + + align:start position:0% +would happen is at the end of the day + + + align:start position:0% +would happen is at the end of the day +you get a function of all the possible + + align:start position:0% +you get a function of all the possible + + + align:start position:0% +you get a function of all the possible +large momenta that you + + align:start position:0% +large momenta that you + + + align:start position:0% +large momenta that you +can form from the operator + + align:start position:0% +can form from the operator + + + align:start position:0% +can form from the operator +so + + align:start position:0% + + + + align:start position:0% + +maybe one more line + + align:start position:0% + + + + align:start position:0% + +so think of it that you can always + + align:start position:0% +so think of it that you can always + + + align:start position:0% +so think of it that you can always +separate out + + align:start position:0% +separate out + + + align:start position:0% +separate out +you can always separate out that + + align:start position:0% + + + + align:start position:0% + +make a split like we did over there with + + align:start position:0% +make a split like we did over there with + + + align:start position:0% +make a split like we did over there with +the integral over some variable and then + + align:start position:0% +the integral over some variable and then + + + align:start position:0% +the integral over some variable and then +leave something that you can stick in + + align:start position:0% +leave something that you can stick in + + + align:start position:0% +leave something that you can stick in +your operator + + align:start position:0% +your operator + + + align:start position:0% +your operator +if you make it like this so this could + + align:start position:0% +if you make it like this so this could + + + align:start position:0% +if you make it like this so this could +go in the operator + + align:start position:0% + + + + align:start position:0% + +and then + + align:start position:0% +and then + + + align:start position:0% +and then +that's the coefficient + + align:start position:0% + + + + align:start position:0% + +well here i didn't write it so if i + + align:start position:0% +well here i didn't write it so if i + + + align:start position:0% +well here i didn't write it so if i +wanted to put in i and bar dot d's i'd + + align:start position:0% +wanted to put in i and bar dot d's i'd + + + align:start position:0% +wanted to put in i and bar dot d's i'd +stick them between + + align:start position:0% +stick them between + + + align:start position:0% +stick them between +right if i wanted to have used the + + align:start position:0% +right if i wanted to have used the + + + align:start position:0% +right if i wanted to have used the +formula if i wanted to use this kind of + + align:start position:0% +formula if i wanted to use this kind of + + + align:start position:0% +formula if i wanted to use this kind of +logic i wouldn't have written this + + align:start position:0% +logic i wouldn't have written this + + + align:start position:0% +logic i wouldn't have written this +and i would have said said let me stick + + align:start position:0% +and i would have said said let me stick + + + align:start position:0% +and i would have said said let me stick +an arbitrary function of i and bar.d in + + align:start position:0% +an arbitrary function of i and bar.d in + + + align:start position:0% +an arbitrary function of i and bar.d in +here + + align:start position:0% +here + + + align:start position:0% +here +sorry before you even write it has to be + + align:start position:0% +sorry before you even write it has to be + + + align:start position:0% +sorry before you even write it has to be +between them because of the gauging + + align:start position:0% +between them because of the gauging + + + align:start position:0% +between them because of the gauging +you even write variance the wilson line + + align:start position:0% +you even write variance the wilson line + + + align:start position:0% +you even write variance the wilson line +so let's say you started to say okay oh + + align:start position:0% +so let's say you started to say okay oh + + + align:start position:0% +so let's say you started to say okay oh +yeah so there's still right this wilson + + align:start position:0% +yeah so there's still right this wilson + + + align:start position:0% +yeah so there's still right this wilson +line here right right this wilson line + + align:start position:0% +line here right right this wilson line + + + align:start position:0% +line here right right this wilson line +here came from this h + + align:start position:0% +here came from this h + + + align:start position:0% +here came from this h +so that's still going to be true + + align:start position:0% +so that's still going to be true + + + align:start position:0% +so that's still going to be true +and what i'm saying if you think about + + align:start position:0% +and what i'm saying if you think about + + + align:start position:0% +and what i'm saying if you think about +this operator + + align:start position:0% +this operator + + + align:start position:0% +this operator +right i could dress it up by putting any + + align:start position:0% +right i could dress it up by putting any + + + align:start position:0% +right i could dress it up by putting any +function of imbar.ds + + align:start position:0% +function of imbar.ds + + + align:start position:0% +function of imbar.ds +right in here + + align:start position:0% +right in here + + + align:start position:0% +right in here +because that would still be an order + + align:start position:0% +because that would still be an order + + + align:start position:0% +because that would still be an order +walk same order and gauge invariant + + align:start position:0% + + + + align:start position:0% + +but then if i use this right then if i + + align:start position:0% +but then if i use this right then if i + + + align:start position:0% +but then if i use this right then if i +use this formula + + align:start position:0% +use this formula + + + align:start position:0% +use this formula +it would sort of + + align:start position:0% +it would sort of + + + align:start position:0% +it would sort of +push + + align:start position:0% +push + + + align:start position:0% +push +this w + + align:start position:0% +this w + + + align:start position:0% +this w +that would cancel there and then this w + + align:start position:0% +that would cancel there and then this w + + + align:start position:0% +that would cancel there and then this w +comes back then you get the f + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so in general the right way of thinking + + align:start position:0% +so in general the right way of thinking + + + align:start position:0% +so in general the right way of thinking +about this is as follows we can + + align:start position:0% +about this is as follows we can + + + align:start position:0% +about this is as follows we can +encode this in some notation + + align:start position:0% + + + + align:start position:0% + +by just setting up a convenient set of + + align:start position:0% +by just setting up a convenient set of + + + align:start position:0% +by just setting up a convenient set of +building blocks + + align:start position:0% +building blocks + + + align:start position:0% +building blocks +which are + + align:start position:0% +which are + + + align:start position:0% +which are +gauge and variant objects under the + + align:start position:0% +gauge and variant objects under the + + + align:start position:0% +gauge and variant objects under the +linear gauge transformations + + align:start position:0% + + + + align:start position:0% + +and so + + align:start position:0% +and so + + + align:start position:0% +and so +we need to have a fermion + + align:start position:0% +we need to have a fermion + + + align:start position:0% +we need to have a fermion +field but we know that the fermion field + + align:start position:0% +field but we know that the fermion field + + + align:start position:0% +field but we know that the fermion field +generically + + align:start position:0% +generically + + + align:start position:0% +generically +we can make it gage invariant by + + align:start position:0% +we can make it gage invariant by + + + align:start position:0% +we can make it gage invariant by +multiplying by a wilson line like that + + align:start position:0% +multiplying by a wilson line like that + + + align:start position:0% +multiplying by a wilson line like that +and because of this what we were just + + align:start position:0% +and because of this what we were just + + + align:start position:0% +and because of this what we were just +discussing here generically we can be in + + align:start position:0% +discussing here generically we can be in + + + align:start position:0% +discussing here generically we can be in +our wilson coefficients sensitive to the + + align:start position:0% +our wilson coefficients sensitive to the + + + align:start position:0% +our wilson coefficients sensitive to the +momentum of this object + + align:start position:0% +momentum of this object + + + align:start position:0% +momentum of this object +and so we can do that + + align:start position:0% +and so we can do that + + + align:start position:0% +and so we can do that +denote that by + + align:start position:0% +denote that by + + + align:start position:0% +denote that by +defining the following thing + + align:start position:0% + + + + align:start position:0% + +which is just a chi + + align:start position:0% +which is just a chi + + + align:start position:0% +which is just a chi +field that carries some momentum which + + align:start position:0% +field that carries some momentum which + + + align:start position:0% +field that carries some momentum which +is the overall large momentum of this + + align:start position:0% +is the overall large momentum of this + + + align:start position:0% +is the overall large momentum of this +product of fields + + align:start position:0% + + + + align:start position:0% + +and sometimes this guy goes by the name + + align:start position:0% +and sometimes this guy goes by the name + + + align:start position:0% +and sometimes this guy goes by the name +of the cork + + align:start position:0% + + + + align:start position:0% + +jet field + + align:start position:0% +jet field + + + align:start position:0% +jet field +because it's kind of the object if you + + align:start position:0% +because it's kind of the object if you + + + align:start position:0% +because it's kind of the object if you +were to produce a quark in the hard + + align:start position:0% +were to produce a quark in the hard + + + align:start position:0% +were to produce a quark in the hard +scattering process the cork would be + + align:start position:0% +scattering process the cork would be + + + align:start position:0% +scattering process the cork would be +represented in your operator by this w + + align:start position:0% +represented in your operator by this w + + + align:start position:0% +represented in your operator by this w +dagger c + + align:start position:0% +dagger c + + + align:start position:0% +dagger c +the wilson coefficients would talk to + + align:start position:0% +the wilson coefficients would talk to + + + align:start position:0% +the wilson coefficients would talk to +that quark through the large momentum + + align:start position:0% +that quark through the large momentum + + + align:start position:0% +that quark through the large momentum +and that quark in the low energy theory + + align:start position:0% +and that quark in the low energy theory + + + align:start position:0% +and that quark in the low energy theory +would evolve into a jet + + align:start position:0% +would evolve into a jet + + + align:start position:0% +would evolve into a jet +so it goes by that name you could also + + align:start position:0% +so it goes by that name you could also + + + align:start position:0% +so it goes by that name you could also +think of it as a part on field + + align:start position:0% + + + + align:start position:0% + +because as it turns out and as we'll + + align:start position:0% +because as it turns out and as we'll + + + align:start position:0% +because as it turns out and as we'll +talk about + + align:start position:0% +talk about + + + align:start position:0% +talk about +later on if you were to think about the + + align:start position:0% +later on if you were to think about the + + + align:start position:0% +later on if you were to think about the +part-time distribution function + + align:start position:0% +part-time distribution function + + + align:start position:0% +part-time distribution function +and what pulls a quark out of the proton + + align:start position:0% +and what pulls a quark out of the proton + + + align:start position:0% +and what pulls a quark out of the proton +it's exactly this operator + + align:start position:0% +it's exactly this operator + + + align:start position:0% +it's exactly this operator +and then that + + align:start position:0% +and then that + + + align:start position:0% +and then that +park's momentum what momentum that quark + + align:start position:0% +park's momentum what momentum that quark + + + align:start position:0% +park's momentum what momentum that quark +carries is exactly picked up by this + + align:start position:0% +carries is exactly picked up by this + + + align:start position:0% +carries is exactly picked up by this +delta function as well + + align:start position:0% + + + + align:start position:0% + +so these are the objects we'll actually + + align:start position:0% +so these are the objects we'll actually + + + align:start position:0% +so these are the objects we'll actually +usually want to work in terms of + + align:start position:0% +usually want to work in terms of + + + align:start position:0% +usually want to work in terms of +we can do something similar for the + + align:start position:0% +we can do something similar for the + + + align:start position:0% +we can do something similar for the +gluon + + align:start position:0% + + + + align:start position:0% + +which is a curly bee + + align:start position:0% + + + + align:start position:0% + +and i'm going to define it + + align:start position:0% +and i'm going to define it + + + align:start position:0% +and i'm going to define it +if we wanted to get a glue on the + + align:start position:0% +if we wanted to get a glue on the + + + align:start position:0% +if we wanted to get a glue on the +natural thing is to use a field strength + + align:start position:0% +natural thing is to use a field strength + + + align:start position:0% +natural thing is to use a field strength +because then you get a glue on without + + align:start position:0% +because then you get a glue on without + + + align:start position:0% +because then you get a glue on without +any derivatives + + align:start position:0% +any derivatives + + + align:start position:0% +any derivatives +but i want my + + align:start position:0% +but i want my + + + align:start position:0% +but i want my +object to be dimension one + + align:start position:0% +object to be dimension one + + + align:start position:0% +object to be dimension one +so i'm going to define it in the + + align:start position:0% +so i'm going to define it in the + + + align:start position:0% +so i'm going to define it in the +following way + + align:start position:0% + + + + align:start position:0% + +so here's a field strength commutator of + + align:start position:0% +so here's a field strength commutator of + + + align:start position:0% +so here's a field strength commutator of +covariant derivatives + + align:start position:0% +covariant derivatives + + + align:start position:0% +covariant derivatives +these are linear derivatives + + align:start position:0% + + + + align:start position:0% + +and i throw wilson lines around it to + + align:start position:0% +and i throw wilson lines around it to + + + align:start position:0% +and i throw wilson lines around it to +make it gauge invariant and then to make + + align:start position:0% +make it gauge invariant and then to make + + + align:start position:0% +make it gauge invariant and then to make +it dimension one i throw in a one over p + + align:start position:0% +it dimension one i throw in a one over p + + + align:start position:0% +it dimension one i throw in a one over p +bar + + align:start position:0% + + + + align:start position:0% + +and if you start expanding this out + + align:start position:0% + + + + align:start position:0% + +then the first term will be the a n perp + + align:start position:0% +then the first term will be the a n perp + + + align:start position:0% +then the first term will be the a n perp +gluon and tell you this b just has the a + + align:start position:0% +gluon and tell you this b just has the a + + + align:start position:0% +gluon and tell you this b just has the a +and perp gluon in the same way that the + + align:start position:0% +and perp gluon in the same way that the + + + align:start position:0% +and perp gluon in the same way that the +first kind of border term in this chi is + + align:start position:0% +first kind of border term in this chi is + + + align:start position:0% +first kind of border term in this chi is +just the fermion if i set the wilson + + align:start position:0% +just the fermion if i set the wilson + + + align:start position:0% +just the fermion if i set the wilson +line to one + + align:start position:0% +line to one + + + align:start position:0% +line to one +okay so it's starting out as a + + align:start position:0% +okay so it's starting out as a + + + align:start position:0% +okay so it's starting out as a +perpendicular gluon + + align:start position:0% +perpendicular gluon + + + align:start position:0% +perpendicular gluon +but it's dressed up in a way that makes + + align:start position:0% +but it's dressed up in a way that makes + + + align:start position:0% +but it's dressed up in a way that makes +it gauge invariant in dimension one + + align:start position:0% + + + + align:start position:0% + +and then just like we did here we can + + align:start position:0% +and then just like we did here we can + + + align:start position:0% +and then just like we did here we can +put a subscript on it with a mega + + align:start position:0% +put a subscript on it with a mega + + + align:start position:0% +put a subscript on it with a mega +to give it to say that we fixed the + + align:start position:0% +to give it to say that we fixed the + + + align:start position:0% +to give it to say that we fixed the +large momentum of it + + align:start position:0% +large momentum of it + + + align:start position:0% +large momentum of it +and + + align:start position:0% + + + + align:start position:0% + +sometimes there's a convention that + + align:start position:0% +sometimes there's a convention that + + + align:start position:0% +sometimes there's a convention that +that's done + + align:start position:0% +that's done + + + align:start position:0% +that's done +you have to decide if you want the + + align:start position:0% +you have to decide if you want the + + + align:start position:0% +you have to decide if you want the +wilson line i mean the delt function to + + align:start position:0% +wilson line i mean the delt function to + + + align:start position:0% +wilson line i mean the delt function to +be a w minus p bar w minus p bar dagger + + align:start position:0% + + + + align:start position:0% + +anyway it doesn't really matter that + + align:start position:0% +anyway it doesn't really matter that + + + align:start position:0% +anyway it doesn't really matter that +much but it's just not because it's just + + align:start position:0% +much but it's just not because it's just + + + align:start position:0% +much but it's just not because it's just +a sign of what you mean by a w + + align:start position:0% +a sign of what you mean by a w + + + align:start position:0% +a sign of what you mean by a w +if it's an outgoing gluon this is a more + + align:start position:0% +if it's an outgoing gluon this is a more + + + align:start position:0% +if it's an outgoing gluon this is a more +convenient convention + + align:start position:0% +convenient convention + + + align:start position:0% +convenient convention +okay and so this delta function here and + + align:start position:0% +okay and so this delta function here and + + + align:start position:0% +okay and so this delta function here and +this p bar here when i put these square + + align:start position:0% +this p bar here when i put these square + + + align:start position:0% +this p bar here when i put these square +brackets what i mean by that is that + + align:start position:0% +brackets what i mean by that is that + + + align:start position:0% +brackets what i mean by that is that +they do they don't act outside they just + + align:start position:0% +they do they don't act outside they just + + + align:start position:0% +they do they don't act outside they just +act on the operators inside + + align:start position:0% +act on the operators inside + + + align:start position:0% +act on the operators inside +so + + align:start position:0% + + + + align:start position:0% + +these are objects that exist by + + align:start position:0% +these are objects that exist by + + + align:start position:0% +these are objects that exist by +themselves and they don't care about + + align:start position:0% +themselves and they don't care about + + + align:start position:0% +themselves and they don't care about +other things that are multiplying them + + align:start position:0% +other things that are multiplying them + + + align:start position:0% +other things that are multiplying them +later + + align:start position:0% + + + + align:start position:0% + +so that's the gluon analog of the quark + + align:start position:0% + + + + align:start position:0% + +so it turns out that we can show + + align:start position:0% + + + + align:start position:0% + +the following + + align:start position:0% + + + + align:start position:0% + +that if you want to build operators that + + align:start position:0% +that if you want to build operators that + + + align:start position:0% +that if you want to build operators that +are subletting order a complete set of + + align:start position:0% +are subletting order a complete set of + + + align:start position:0% +are subletting order a complete set of +things to do that is as follows it's + + align:start position:0% +things to do that is as follows it's + + + align:start position:0% +things to do that is as follows it's +this cayenne + + align:start position:0% +this cayenne + + + align:start position:0% +this cayenne +the bn perp + + align:start position:0% + + + + align:start position:0% + +and then + + align:start position:0% +and then + + + align:start position:0% +and then +you could also need + + align:start position:0% +you could also need + + + align:start position:0% +you could also need +p perps + + align:start position:0% +p perps + + + align:start position:0% +p perps +and then you could also have ultrasoft + + align:start position:0% +and then you could also have ultrasoft + + + align:start position:0% +and then you could also have ultrasoft +fields + + align:start position:0% + + + + align:start position:0% + +where it's really kind of similar to how + + align:start position:0% +where it's really kind of similar to how + + + align:start position:0% +where it's really kind of similar to how +you're used to building operators and + + align:start position:0% +you're used to building operators and + + + align:start position:0% +you're used to building operators and +effective field theories + + align:start position:0% +effective field theories + + + align:start position:0% +effective field theories +but if you just want to talk about the + + align:start position:0% +but if you just want to talk about the + + + align:start position:0% +but if you just want to talk about the +clinical sector the only things you need + + align:start position:0% +clinical sector the only things you need + + + align:start position:0% +clinical sector the only things you need +are this chi in this bn field and then p + + align:start position:0% +are this chi in this bn field and then p + + + align:start position:0% +are this chi in this bn field and then p +perps and no other things + + align:start position:0% + + + + align:start position:0% + +all orders so why aren't there any i'll + + align:start position:0% +all orders so why aren't there any i'll + + + align:start position:0% +all orders so why aren't there any i'll +talk about it + + align:start position:0% +talk about it + + + align:start position:0% +talk about it +yeah we'll show you i'll show you + + align:start position:0% +yeah we'll show you i'll show you + + + align:start position:0% +yeah we'll show you i'll show you +yeah i mean intuitively you would think + + align:start position:0% +yeah i mean intuitively you would think + + + align:start position:0% +yeah i mean intuitively you would think +these are the physical degrees of + + align:start position:0% +these are the physical degrees of + + + align:start position:0% +these are the physical degrees of +freedom right there's two of them + + align:start position:0% +freedom right there's two of them + + + align:start position:0% +freedom right there's two of them +so that's intuitive but i'll show you + + align:start position:0% +so that's intuitive but i'll show you + + + align:start position:0% +so that's intuitive but i'll show you +how you get rid of all the other ones + + align:start position:0% + + + + align:start position:0% + +it kind of matches up with what you want + + align:start position:0% +it kind of matches up with what you want + + + align:start position:0% +it kind of matches up with what you want +you could think that you know these are + + align:start position:0% +you could think that you know these are + + + align:start position:0% +you could think that you know these are +the physical gluons that you're + + align:start position:0% +the physical gluons that you're + + + align:start position:0% +the physical gluons that you're +producing and your operators can be set + + align:start position:0% +producing and your operators can be set + + + align:start position:0% +producing and your operators can be set +up so that they only depend + + align:start position:0% +up so that they only depend + + + align:start position:0% +up so that they only depend +that there's not so sort of any spurious + + align:start position:0% + + + + align:start position:0% + +components + + align:start position:0% + + + + align:start position:0% + +okay so + + align:start position:0% +okay so + + + align:start position:0% +okay so +we'll get there + + align:start position:0% + + + + align:start position:0% + +so let me do let me introduce a bit of + + align:start position:0% +so let me do let me introduce a bit of + + + align:start position:0% +so let me do let me introduce a bit of +notation + + align:start position:0% + + + + align:start position:0% + +i have to do + + align:start position:0% + + + + align:start position:0% + +so let's consider this thing a covalent + + align:start position:0% +so let's consider this thing a covalent + + + align:start position:0% +so let's consider this thing a covalent +derivative sandwiched with wilson lines + + align:start position:0% +derivative sandwiched with wilson lines + + + align:start position:0% +derivative sandwiched with wilson lines +on either side + + align:start position:0% +on either side + + + align:start position:0% +on either side +and this idn here + + align:start position:0% +and this idn here + + + align:start position:0% +and this idn here +is like p bar plus + + align:start position:0% + + + + align:start position:0% + +so it just involves the linear gluon + + align:start position:0% +so it just involves the linear gluon + + + align:start position:0% +so it just involves the linear gluon +field + + align:start position:0% + + + + align:start position:0% + +so then if i have that operator and i + + align:start position:0% +so then if i have that operator and i + + + align:start position:0% +so then if i have that operator and i +just take n bar + + align:start position:0% +just take n bar + + + align:start position:0% +just take n bar +idn then that's p bar + + align:start position:0% + + + + align:start position:0% + +if i take + + align:start position:0% +if i take + + + align:start position:0% +if i take +i + + align:start position:0% +i + + + align:start position:0% +i +d n perp mu + + align:start position:0% +d n perp mu + + + align:start position:0% +d n perp mu +then you can show + + align:start position:0% +then you can show + + + align:start position:0% +then you can show +that this guy is p perp u + + align:start position:0% +that this guy is p perp u + + + align:start position:0% +that this guy is p perp u +plus g + + align:start position:0% +plus g + + + align:start position:0% +plus g +b n perp mu + + align:start position:0% + + + + align:start position:0% + +so this one is just a relation we talked + + align:start position:0% +so this one is just a relation we talked + + + align:start position:0% +so this one is just a relation we talked +about before this one is not as obvious + + align:start position:0% +about before this one is not as obvious + + + align:start position:0% +about before this one is not as obvious +but + + align:start position:0% +but + + + align:start position:0% +but +if you take this guy you can either let + + align:start position:0% +if you take this guy you can either let + + + align:start position:0% +if you take this guy you can either let +the derivative you can let this + + align:start position:0% +the derivative you can let this + + + align:start position:0% +the derivative you can let this +derivative + + align:start position:0% +derivative + + + align:start position:0% +derivative +act on the wilson line or act through if + + align:start position:0% +act on the wilson line or act through if + + + align:start position:0% +act on the wilson line or act through if +it acts through that's this term + + align:start position:0% +it acts through that's this term + + + align:start position:0% +it acts through that's this term +if it acts on then i can manipulate the + + align:start position:0% +if it acts on then i can manipulate the + + + align:start position:0% +if it acts on then i can manipulate the +operator + + align:start position:0% +operator + + + align:start position:0% +operator +so that it is exactly of this form + + align:start position:0% +so that it is exactly of this form + + + align:start position:0% +so that it is exactly of this form +and part of that comes from the fact + + align:start position:0% +and part of that comes from the fact + + + align:start position:0% +and part of that comes from the fact +that + + align:start position:0% +that + + + align:start position:0% +that +i can explain it to you here i have it + + align:start position:0% +i can explain it to you here i have it + + + align:start position:0% +i can explain it to you here i have it +in my notes and you can look at it later + + align:start position:0% +in my notes and you can look at it later + + + align:start position:0% +in my notes and you can look at it later +but let me just explain it in words if + + align:start position:0% +but let me just explain it in words if + + + align:start position:0% +but let me just explain it in words if +you looked at the term in this + + align:start position:0% +you looked at the term in this + + + align:start position:0% +you looked at the term in this +commutator that was the other order + + align:start position:0% +commutator that was the other order + + + align:start position:0% +commutator that was the other order +where the i n bar dot d was acting up + + align:start position:0% +where the i n bar dot d was acting up + + + align:start position:0% +where the i n bar dot d was acting up +was sitting here it would hit the wilson + + align:start position:0% +was sitting here it would hit the wilson + + + align:start position:0% +was sitting here it would hit the wilson +line you get zero so that term was just + + align:start position:0% +line you get zero so that term was just + + + align:start position:0% +line you get zero so that term was just +put in to make it look like a gauge + + align:start position:0% +put in to make it look like a gauge + + + align:start position:0% +put in to make it look like a gauge +field i mean a covariant + + align:start position:0% +field i mean a covariant + + + align:start position:0% +field i mean a covariant +to make it look like a field strength + + align:start position:0% +to make it look like a field strength + + + align:start position:0% +to make it look like a field strength +uh + + align:start position:0% +uh + + + align:start position:0% +uh +okay so so really you have i am bar.d dn + + align:start position:0% +okay so so really you have i am bar.d dn + + + align:start position:0% +okay so so really you have i am bar.d dn +perp without the + + align:start position:0% +perp without the + + + align:start position:0% +perp without the +without the comma without the brackets + + align:start position:0% +without the comma without the brackets + + + align:start position:0% +without the comma without the brackets +but then this combination here + + align:start position:0% +but then this combination here + + + align:start position:0% +but then this combination here +uh + + align:start position:0% +uh + + + align:start position:0% +uh +this combination here is just + + align:start position:0% +this combination here is just + + + align:start position:0% +this combination here is just +you can use the identity that we had + + align:start position:0% +you can use the identity that we had + + + align:start position:0% +you can use the identity that we had +with the and basically + + align:start position:0% +with the and basically + + + align:start position:0% +with the and basically +if you push this guy through here you're + + align:start position:0% +if you push this guy through here you're + + + align:start position:0% +if you push this guy through here you're +canceling the p bar + + align:start position:0% +canceling the p bar + + + align:start position:0% +canceling the p bar +so it's just giving you the wilson line + + align:start position:0% +so it's just giving you the wilson line + + + align:start position:0% +so it's just giving you the wilson line +so that's basically + + align:start position:0% +so that's basically + + + align:start position:0% +so that's basically +how you go from here to here + + align:start position:0% +how you go from here to here + + + align:start position:0% +how you go from here to here +okay so this is by way of arguing that i + + align:start position:0% +okay so this is by way of arguing that i + + + align:start position:0% +okay so this is by way of arguing that i +don't really need if i'm considering p + + align:start position:0% +don't really need if i'm considering p + + + align:start position:0% +don't really need if i'm considering p +this is basically what this is saying is + + align:start position:0% +this is basically what this is saying is + + + align:start position:0% +this is basically what this is saying is +i don't need to consider covariant + + align:start position:0% +i don't need to consider covariant + + + align:start position:0% +i don't need to consider covariant +derivatives because i can instead + + align:start position:0% +derivatives because i can instead + + + align:start position:0% +derivatives because i can instead +consider p perps and b perps and that's + + align:start position:0% +consider p perps and b perps and that's + + + align:start position:0% +consider p perps and b perps and that's +equally good + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +now + + align:start position:0% + + + + align:start position:0% + +if you do a similar type of thing + + align:start position:0% +if you do a similar type of thing + + + align:start position:0% +if you do a similar type of thing +in the end component + + align:start position:0% +in the end component + + + align:start position:0% +in the end component +then you can derive a similar type of + + align:start position:0% +then you can derive a similar type of + + + align:start position:0% +then you can derive a similar type of +object so this is the same object as we + + align:start position:0% +object so this is the same object as we + + + align:start position:0% +object so this is the same object as we +have over here but instead of having an + + align:start position:0% +have over here but instead of having an + + + align:start position:0% +have over here but instead of having an +idn perp i'd have an n dot d + + align:start position:0% + + + + align:start position:0% + +so dn replace to + + align:start position:0% +so dn replace to + + + align:start position:0% +so dn replace to +n.d + + align:start position:0% + + + + align:start position:0% + +and that looks like it could be + + align:start position:0% +and that looks like it could be + + + align:start position:0% +and that looks like it could be +something that you build operators out + + align:start position:0% +something that you build operators out + + + align:start position:0% +something that you build operators out +of + + align:start position:0% +of + + + align:start position:0% +of +so why not and and also furthermore why + + align:start position:0% +so why not and and also furthermore why + + + align:start position:0% +so why not and and also furthermore why +not have operators that depend on this + + align:start position:0% +not have operators that depend on this + + + align:start position:0% +not have operators that depend on this +end up partial + + align:start position:0% +end up partial + + + align:start position:0% +end up partial +okay + + align:start position:0% + + + + align:start position:0% + +so for p bar we don't have to worry + + align:start position:0% +so for p bar we don't have to worry + + + align:start position:0% +so for p bar we don't have to worry +about that + + align:start position:0% +about that + + + align:start position:0% +about that +so okay we have you know i said we'll + + align:start position:0% +so okay we have you know i said we'll + + + align:start position:0% +so okay we have you know i said we'll +include this we'll include that + + align:start position:0% +include this we'll include that + + + align:start position:0% +include this we'll include that +i didn't say we include this this and + + align:start position:0% +i didn't say we include this this and + + + align:start position:0% +i didn't say we include this this and +this so there's three things i have to + + align:start position:0% +this so there's three things i have to + + + align:start position:0% +this so there's three things i have to +argue away here + + align:start position:0% +argue away here + + + align:start position:0% +argue away here +the derivatives that are p bars those + + align:start position:0% +the derivatives that are p bars those + + + align:start position:0% +the derivatives that are p bars those +just go into the wilson coefficient so + + align:start position:0% +just go into the wilson coefficient so + + + align:start position:0% +just go into the wilson coefficient so +if we had like p bar + + align:start position:0% +if we had like p bar + + + align:start position:0% +if we had like p bar +chi m comma + + align:start position:0% +chi m comma + + + align:start position:0% +chi m comma +omega for example + + align:start position:0% +omega for example + + + align:start position:0% +omega for example +and that's omega + + align:start position:0% +and that's omega + + + align:start position:0% +and that's omega +k n comma omega and this is in the + + align:start position:0% +k n comma omega and this is in the + + + align:start position:0% +k n comma omega and this is in the +put into the wilson coefficient + + align:start position:0% + + + + align:start position:0% + +so that's why we don't have to worry + + align:start position:0% +so that's why we don't have to worry + + + align:start position:0% +so that's why we don't have to worry +about having p bars + + align:start position:0% +about having p bars + + + align:start position:0% +about having p bars +in some sense we do have p bars they're + + align:start position:0% +in some sense we do have p bars they're + + + align:start position:0% +in some sense we do have p bars they're +all in the wilson coefficients + + align:start position:0% +all in the wilson coefficients + + + align:start position:0% +all in the wilson coefficients +so it's really these other two that we + + align:start position:0% +so it's really these other two that we + + + align:start position:0% +so it's really these other two that we +have to worry more about + + align:start position:0% +have to worry more about + + + align:start position:0% +have to worry more about +and those actually can be simplified + + align:start position:0% +and those actually can be simplified + + + align:start position:0% +and those actually can be simplified +using the equation of motion so + + align:start position:0% +using the equation of motion so + + + align:start position:0% +using the equation of motion so +if you have i and dot p on i end up + + align:start position:0% +if you have i and dot p on i end up + + + align:start position:0% +if you have i and dot p on i end up +partial on cayenne then the equation of + + align:start position:0% +partial on cayenne then the equation of + + + align:start position:0% +partial on cayenne then the equation of +motion + + align:start position:0% +motion + + + align:start position:0% +motion +when you write it out in terms of these + + align:start position:0% +when you write it out in terms of these + + + align:start position:0% +when you write it out in terms of these +objects + + align:start position:0% + + + + align:start position:0% + +it has some form + + align:start position:0% +it has some form + + + align:start position:0% +it has some form +and basically you can just get rid of + + align:start position:0% +and basically you can just get rid of + + + align:start position:0% +and basically you can just get rid of +those terms + + align:start position:0% + + + + align:start position:0% + +so equation of motion allows us to get + + align:start position:0% +so equation of motion allows us to get + + + align:start position:0% +so equation of motion allows us to get +rid of ion dot + + align:start position:0% +rid of ion dot + + + align:start position:0% +rid of ion dot +partials that are on chi ends + + align:start position:0% + + + + align:start position:0% + +so that's why we don't have to worry + + align:start position:0% +so that's why we don't have to worry + + + align:start position:0% +so that's why we don't have to worry +about + + align:start position:0% + + + + align:start position:0% + +those and this is just like + + align:start position:0% +those and this is just like + + + align:start position:0% +those and this is just like +saying that in our leading order action + + align:start position:0% +saying that in our leading order action + + + align:start position:0% +saying that in our leading order action +in our leading order action there wasn't + + align:start position:0% +in our leading order action there wasn't + + + align:start position:0% +in our leading order action there wasn't +i end up partial + + align:start position:0% +i end up partial + + + align:start position:0% +i end up partial +but and that's just like saying there + + align:start position:0% +but and that's just like saying there + + + align:start position:0% +but and that's just like saying there +was time derivatives in our leading + + align:start position:0% +was time derivatives in our leading + + + align:start position:0% +was time derivatives in our leading +order action in some standard effective + + align:start position:0% +order action in some standard effective + + + align:start position:0% +order action in some standard effective +field theory + + align:start position:0% +field theory + + + align:start position:0% +field theory +but then in the low in the higher + + align:start position:0% +but then in the low in the higher + + + align:start position:0% +but then in the low in the higher +dimension operators you can always use + + align:start position:0% +dimension operators you can always use + + + align:start position:0% +dimension operators you can always use +the equations of motion to get rid of + + align:start position:0% +the equations of motion to get rid of + + + align:start position:0% +the equations of motion to get rid of +those time derivatives and here we're + + align:start position:0% +those time derivatives and here we're + + + align:start position:0% +those time derivatives and here we're +using the equation of motion to get rid + + align:start position:0% +using the equation of motion to get rid + + + align:start position:0% +using the equation of motion to get rid +of i end up partial so it appears in the + + align:start position:0% +of i end up partial so it appears in the + + + align:start position:0% +of i end up partial so it appears in the +leading reaction but then we don't have + + align:start position:0% +leading reaction but then we don't have + + + align:start position:0% +leading reaction but then we don't have +to have it in any other + + align:start position:0% +to have it in any other + + + align:start position:0% +to have it in any other +subleading operator and that's why it's + + align:start position:0% +subleading operator and that's why it's + + + align:start position:0% +subleading operator and that's why it's +not one of the ones + + align:start position:0% + + + + align:start position:0% + +that's included in the list + + align:start position:0% +that's included in the list + + + align:start position:0% +that's included in the list +and if you had i end up partial on curly + + align:start position:0% +and if you had i end up partial on curly + + + align:start position:0% +and if you had i end up partial on curly +b that's also a part of the equations of + + align:start position:0% +b that's also a part of the equations of + + + align:start position:0% +b that's also a part of the equations of +motion of the gluon field + + align:start position:0% + + + + align:start position:0% + +now when you do the gluon equations of + + align:start position:0% +now when you do the gluon equations of + + + align:start position:0% +now when you do the gluon equations of +motion there's components because it's a + + align:start position:0% +motion there's components because it's a + + + align:start position:0% +motion there's components because it's a +vector + + align:start position:0% +vector + + + align:start position:0% +vector +and one of the other components allows + + align:start position:0% +and one of the other components allows + + + align:start position:0% +and one of the other components allows +you to get rid of the end of n dot b + + align:start position:0% +you to get rid of the end of n dot b + + + align:start position:0% +you to get rid of the end of n dot b +so there's another term that you can + + align:start position:0% +so there's another term that you can + + + align:start position:0% +so there's another term that you can +rearrange + + align:start position:0% +rearrange + + + align:start position:0% +rearrange +and i won't write it out because the + + align:start position:0% +and i won't write it out because the + + + align:start position:0% +and i won't write it out because the +equation is rather messy but + + align:start position:0% + + + + align:start position:0% + +give you some idea + + align:start position:0% + + + + align:start position:0% + +there's another component that + + align:start position:0% + + + + align:start position:0% + +looks like this + + align:start position:0% +looks like this + + + align:start position:0% +looks like this +where i can get rid of all the n-dot + + align:start position:0% +where i can get rid of all the n-dot + + + align:start position:0% +where i can get rid of all the n-dot +curly b's using the gluon equipped so i + + align:start position:0% +curly b's using the gluon equipped so i + + + align:start position:0% +curly b's using the gluon equipped so i +the glue on equations of motions allows + + align:start position:0% +the glue on equations of motions allows + + + align:start position:0% +the glue on equations of motions allows +me to get rid of both of these things + + align:start position:0% +me to get rid of both of these things + + + align:start position:0% +me to get rid of both of these things +and then i just have the and basically + + align:start position:0% +and then i just have the and basically + + + align:start position:0% +and then i just have the and basically +after i've done that i just have the + + align:start position:0% +after i've done that i just have the + + + align:start position:0% +after i've done that i just have the +objects that i've + + align:start position:0% +objects that i've + + + align:start position:0% +objects that i've +told you we can use + + align:start position:0% + + + + align:start position:0% + +so after using equations of motion we + + align:start position:0% +so after using equations of motion we + + + align:start position:0% +so after using equations of motion we +can get down to those objects + + align:start position:0% + + + + align:start position:0% + +and any other thing + + align:start position:0% +and any other thing + + + align:start position:0% +and any other thing +that you might dream up + + align:start position:0% +that you might dream up + + + align:start position:0% +that you might dream up +can be reduced + + align:start position:0% +can be reduced + + + align:start position:0% +can be reduced +to these objects + + align:start position:0% +to these objects + + + align:start position:0% +to these objects +so i'm not + + align:start position:0% +so i'm not + + + align:start position:0% +so i'm not +saying that i went through a complete + + align:start position:0% +saying that i went through a complete + + + align:start position:0% +saying that i went through a complete +list here for example what if you had a + + align:start position:0% +list here for example what if you had a + + + align:start position:0% +list here for example what if you had a +commutator of two + + align:start position:0% +commutator of two + + + align:start position:0% +commutator of two +dn perps + + align:start position:0% +dn perps + + + align:start position:0% +dn perps +right you might say oh that's some new + + align:start position:0% +right you might say oh that's some new + + + align:start position:0% +right you might say oh that's some new +thing + + align:start position:0% +thing + + + align:start position:0% +thing +it's not + + align:start position:0% +it's not + + + align:start position:0% +it's not +it's one of these you can also reduce + + align:start position:0% +it's one of these you can also reduce + + + align:start position:0% +it's one of these you can also reduce +that too + + align:start position:0% + + + + align:start position:0% + +so let me list that one just to give you + + align:start position:0% +so let me list that one just to give you + + + align:start position:0% +so let me list that one just to give you +some idea that there's + + align:start position:0% +some idea that there's + + + align:start position:0% +some idea that there's +others you might think of dreaming up + + align:start position:0% + + + + align:start position:0% + +so you can reduce all others to this set + + align:start position:0% +so you can reduce all others to this set + + + align:start position:0% +so you can reduce all others to this set +okay so for the linear sector this is + + align:start position:0% +okay so for the linear sector this is + + + align:start position:0% +okay so for the linear sector this is +enough for higher to build higher + + align:start position:0% +enough for higher to build higher + + + align:start position:0% +enough for higher to build higher +dimension operators just these three + + align:start position:0% +dimension operators just these three + + + align:start position:0% +dimension operators just these three +and then for the ultrasoft sector + + align:start position:0% +and then for the ultrasoft sector + + + align:start position:0% +and then for the ultrasoft sector +so i guess + + align:start position:0% +so i guess + + + align:start position:0% +so i guess +this is two + + align:start position:0% +this is two + + + align:start position:0% +this is two +we do need ultra soft cleaner drip + + align:start position:0% +we do need ultra soft cleaner drip + + + align:start position:0% +we do need ultra soft cleaner drip +ultrasoft derivatives + + align:start position:0% + + + + align:start position:0% + +and ultrasoft field strengths + + align:start position:0% + + + + align:start position:0% + +and ultrasoft quarks + + align:start position:0% + + + + align:start position:0% + +so this part is really just similar to + + align:start position:0% +so this part is really just similar to + + + align:start position:0% +so this part is really just similar to +the story that you'd have + + align:start position:0% +the story that you'd have + + + align:start position:0% +the story that you'd have +for a standard low energy effective + + align:start position:0% +for a standard low energy effective + + + align:start position:0% +for a standard low energy effective +field theory + + align:start position:0% +field theory + + + align:start position:0% +field theory +like integrating out a massive particle + + align:start position:0% +like integrating out a massive particle + + + align:start position:0% +like integrating out a massive particle +you can use the equation of motion + + align:start position:0% + + + + align:start position:0% + +one thing that + + align:start position:0% +one thing that + + + align:start position:0% +one thing that +is worth commenting about is the + + align:start position:0% +is worth commenting about is the + + + align:start position:0% +is worth commenting about is the +connection between one and two so one is + + align:start position:0% +connection between one and two so one is + + + align:start position:0% +connection between one and two so one is +collinear and two is ultra soft and a + + align:start position:0% +collinear and two is ultra soft and a + + + align:start position:0% +collinear and two is ultra soft and a +priori you might think well just + + align:start position:0% +priori you might think well just + + + align:start position:0% +priori you might think well just +they're totally independent but we saw + + align:start position:0% +they're totally independent but we saw + + + align:start position:0% +they're totally independent but we saw +last time that re-parametrization and + + align:start position:0% +last time that re-parametrization and + + + align:start position:0% +last time that re-parametrization and +variance connects them + + align:start position:0% +variance connects them + + + align:start position:0% +variance connects them +so if i've decided that this is the type + + align:start position:0% +so if i've decided that this is the type + + + align:start position:0% +so if i've decided that this is the type +of basis i want to use for my operators + + align:start position:0% +of basis i want to use for my operators + + + align:start position:0% +of basis i want to use for my operators +then what is the reparameterization + + align:start position:0% +then what is the reparameterization + + + align:start position:0% +then what is the reparameterization +connection + + align:start position:0% +connection + + + align:start position:0% +connection +you can rewrite what we said last time + + align:start position:0% +you can rewrite what we said last time + + + align:start position:0% +you can rewrite what we said last time +in terms of these curly d's + + align:start position:0% +in terms of these curly d's + + + align:start position:0% +in terms of these curly d's +because it basically just means moving + + align:start position:0% +because it basically just means moving + + + align:start position:0% +because it basically just means moving +the wilson lines that we had in this + + align:start position:0% +the wilson lines that we had in this + + + align:start position:0% +the wilson lines that we had in this +formula last time + + align:start position:0% + + + + align:start position:0% + +they were around the ultrasoft + + align:start position:0% +they were around the ultrasoft + + + align:start position:0% +they were around the ultrasoft +operator last time + + align:start position:0% +operator last time + + + align:start position:0% +operator last time +and if i just move them over to the + + align:start position:0% +and if i just move them over to the + + + align:start position:0% +and if i just move them over to the +cliniar operator then i get this curly d + + align:start position:0% +cliniar operator then i get this curly d + + + align:start position:0% +cliniar operator then i get this curly d +right so the rpi + + align:start position:0% +right so the rpi + + + align:start position:0% +right so the rpi +connection + + align:start position:0% + + + + align:start position:0% + +is connecting the curly d to the d ultra + + align:start position:0% +is connecting the curly d to the d ultra + + + align:start position:0% +is connecting the curly d to the d ultra +curly d linear to the d ultra soft and + + align:start position:0% +curly d linear to the d ultra soft and + + + align:start position:0% +curly d linear to the d ultra soft and +then you can write this guy as the p + + align:start position:0% +then you can write this guy as the p + + + align:start position:0% +then you can write this guy as the p +part plus the b perp + + align:start position:0% +part plus the b perp + + + align:start position:0% +part plus the b perp +okay so that's + + align:start position:0% +okay so that's + + + align:start position:0% +okay so that's +and likewise + + align:start position:0% +and likewise + + + align:start position:0% +and likewise +if you do the same for the n bar sector + + align:start position:0% +if you do the same for the n bar sector + + + align:start position:0% +if you do the same for the n bar sector +you move the wilson lines + + align:start position:0% +you move the wilson lines + + + align:start position:0% +you move the wilson lines +from this term to that term then it + + align:start position:0% +from this term to that term then it + + + align:start position:0% +from this term to that term then it +looks like these two combinations so + + align:start position:0% +looks like these two combinations so + + + align:start position:0% +looks like these two combinations so +that's just rewriting what we had before + + align:start position:0% +that's just rewriting what we had before + + + align:start position:0% +that's just rewriting what we had before +but now in terms of these + + align:start position:0% +but now in terms of these + + + align:start position:0% +but now in terms of these +this type of notation + + align:start position:0% + + + + align:start position:0% + +okay so that's enough to build operators + + align:start position:0% +okay so that's enough to build operators + + + align:start position:0% +okay so that's enough to build operators +at higher order + + align:start position:0% +at higher order + + + align:start position:0% +at higher order +and then + + align:start position:0% +and then + + + align:start position:0% +and then +we + + align:start position:0% +we + + + align:start position:0% +we +write down wilson coefficients for those + + align:start position:0% +write down wilson coefficients for those + + + align:start position:0% +write down wilson coefficients for those +operators that are functions of the + + align:start position:0% +operators that are functions of the + + + align:start position:0% +operators that are functions of the +large momentum and then we start doing + + align:start position:0% +large momentum and then we start doing + + + align:start position:0% +large momentum and then we start doing +physics with them + + align:start position:0% +physics with them + + + align:start position:0% +physics with them +so any questions about that + + align:start position:0% + + + + align:start position:0% + +what are the equations of motion yeah + + align:start position:0% +what are the equations of motion yeah + + + align:start position:0% +what are the equations of motion yeah +you always just use the leading order + + align:start position:0% +you always just use the leading order + + + align:start position:0% +you always just use the leading order +equation motion yeah into higher order + + align:start position:0% +equation motion yeah into higher order + + + align:start position:0% +equation motion yeah into higher order +yeah these are the l zero equations of + + align:start position:0% +yeah these are the l zero equations of + + + align:start position:0% +yeah these are the l zero equations of +motion that's what i'm doing here + + align:start position:0% +motion that's what i'm doing here + + + align:start position:0% +motion that's what i'm doing here +writing here + + align:start position:0% + + + + align:start position:0% + +yeah there's one more actually there's + + align:start position:0% +yeah there's one more actually there's + + + align:start position:0% +yeah there's one more actually there's +three that + + align:start position:0% + + + + align:start position:0% + +it's only needed at some very high order + + align:start position:0% +it's only needed at some very high order + + + align:start position:0% +it's only needed at some very high order +but + + align:start position:0% +but + + + align:start position:0% +but +okay so + + align:start position:0% +okay so + + + align:start position:0% +okay so +the next thing i want to talk about + + align:start position:0% +the next thing i want to talk about + + + align:start position:0% +the next thing i want to talk about +before we start doing + + align:start position:0% +before we start doing + + + align:start position:0% +before we start doing +explicit examples and going through + + align:start position:0% +explicit examples and going through + + + align:start position:0% +explicit examples and going through +processes is how loops work in this + + align:start position:0% +processes is how loops work in this + + + align:start position:0% +processes is how loops work in this +effective theory + + align:start position:0% + + + + align:start position:0% + +and we're going to have to come back and + + align:start position:0% +and we're going to have to come back and + + + align:start position:0% +and we're going to have to come back and +talk about our grid that we had for this + + align:start position:0% +talk about our grid that we had for this + + + align:start position:0% +talk about our grid that we had for this +split up of momentum how should we + + align:start position:0% +split up of momentum how should we + + + align:start position:0% +split up of momentum how should we +actually think about it in + + align:start position:0% +actually think about it in + + + align:start position:0% +actually think about it in +practice + + align:start position:0% + + + + align:start position:0% + +and then we'll also deal with how + + align:start position:0% +and then we'll also deal with how + + + align:start position:0% +and then we'll also deal with how +matching and running work + + align:start position:0% + + + + align:start position:0% + +so i'm going to do this in the context + + align:start position:0% +so i'm going to do this in the context + + + align:start position:0% +so i'm going to do this in the context +of an example and again i'm just going + + align:start position:0% +of an example and again i'm just going + + + align:start position:0% +of an example and again i'm just going +to pick the simplest example that has + + align:start position:0% +to pick the simplest example that has + + + align:start position:0% +to pick the simplest example that has +only one jet + + align:start position:0% +only one jet + + + align:start position:0% +only one jet +just to make our lives a little bit + + align:start position:0% +just to make our lives a little bit + + + align:start position:0% +just to make our lives a little bit +simpler + + align:start position:0% + + + + align:start position:0% + +so we'll consider our heavy-duty light + + align:start position:0% +so we'll consider our heavy-duty light + + + align:start position:0% +so we'll consider our heavy-duty light +current + + align:start position:0% + + + + align:start position:0% + +and i think actually once you see how it + + align:start position:0% +and i think actually once you see how it + + + align:start position:0% +and i think actually once you see how it +works in this example + + align:start position:0% +works in this example + + + align:start position:0% +works in this example +you'll understand what all the all the + + align:start position:0% +you'll understand what all the all the + + + align:start position:0% +you'll understand what all the all the +general features are of + + align:start position:0% +general features are of + + + align:start position:0% +general features are of +doing loops in sct + + align:start position:0% + + + + align:start position:0% + +so we had + + align:start position:0% + + + + align:start position:0% + +operators that we constructed lowest + + align:start position:0% +operators that we constructed lowest + + + align:start position:0% +operators that we constructed lowest +order operator + + align:start position:0% + + + + align:start position:0% + +and let me write it in this + + align:start position:0% +and let me write it in this + + + align:start position:0% +and let me write it in this +way which was + + align:start position:0% +way which was + + + align:start position:0% +way which was +prior to making our field redefinition + + align:start position:0% +prior to making our field redefinition + + + align:start position:0% +prior to making our field redefinition +i'll just write it this way if i want + + align:start position:0% +i'll just write it this way if i want + + + align:start position:0% +i'll just write it this way if i want +and gamma + + align:start position:0% +and gamma + + + align:start position:0% +and gamma +for bds gamma + + align:start position:0% +for bds gamma + + + align:start position:0% +for bds gamma +is a tensor operator + + align:start position:0% + + + + align:start position:0% + +and there's + + align:start position:0% +and there's + + + align:start position:0% +and there's +a photon field + + align:start position:0% +a photon field + + + align:start position:0% +a photon field +which is a field strength f menu so + + align:start position:0% +which is a field strength f menu so + + + align:start position:0% +which is a field strength f menu so +let's just think of that as all part of + + align:start position:0% +let's just think of that as all part of + + + align:start position:0% +let's just think of that as all part of +the gamma + + align:start position:0% +the gamma + + + align:start position:0% +the gamma +okay and then that's also appearing here + + align:start position:0% +okay and then that's also appearing here + + + align:start position:0% +okay and then that's also appearing here +and i could use the spin structure + + align:start position:0% +and i could use the spin structure + + + align:start position:0% +and i could use the spin structure +properties of these things to reduce the + + align:start position:0% +properties of these things to reduce the + + + align:start position:0% +properties of these things to reduce the +sigma mu but + + align:start position:0% +sigma mu but + + + align:start position:0% +sigma mu but +that's not really going to be part of + + align:start position:0% +that's not really going to be part of + + + align:start position:0% +that's not really going to be part of +our story so let's not bother with that + + align:start position:0% +our story so let's not bother with that + + + align:start position:0% +our story so let's not bother with that +so what do i do i just compute the qcd + + align:start position:0% +so what do i do i just compute the qcd + + + align:start position:0% +so what do i do i just compute the qcd +loops and the sct loops and i compare + + align:start position:0% +loops and the sct loops and i compare + + + align:start position:0% +loops and the sct loops and i compare +them + + align:start position:0% +them + + + align:start position:0% +them +and if sct is the right effective theory + + align:start position:0% +and if sct is the right effective theory + + + align:start position:0% +and if sct is the right effective theory +for this + + align:start position:0% +for this + + + align:start position:0% +for this +limit where i have an energetic photon + + align:start position:0% +limit where i have an energetic photon + + + align:start position:0% +limit where i have an energetic photon +and a back to back with an energetic + + align:start position:0% +and a back to back with an energetic + + + align:start position:0% +and a back to back with an energetic +strange quark + + align:start position:0% +strange quark + + + align:start position:0% +strange quark +then i should match all the infra + + align:start position:0% +then i should match all the infra + + + align:start position:0% +then i should match all the infra +divergences in that qcd computation + + align:start position:0% +divergences in that qcd computation + + + align:start position:0% +divergences in that qcd computation +i should be able to extract the matching + + align:start position:0% +i should be able to extract the matching + + + align:start position:0% +i should be able to extract the matching +coefficient + + align:start position:0% +coefficient + + + align:start position:0% +coefficient +i should be able to determine this what + + align:start position:0% +i should be able to determine this what + + + align:start position:0% +i should be able to determine this what +the c is + + align:start position:0% +the c is + + + align:start position:0% +the c is +from that calculation + + align:start position:0% +from that calculation + + + align:start position:0% +from that calculation +and i should be able to run the operator + + align:start position:0% +and i should be able to run the operator + + + align:start position:0% +and i should be able to run the operator +i should be able to + + align:start position:0% +i should be able to + + + align:start position:0% +i should be able to +make this into ms bar do some more + + align:start position:0% +make this into ms bar do some more + + + align:start position:0% +make this into ms bar do some more +normalization + + align:start position:0% +normalization + + + align:start position:0% +normalization +of this operator and then do some + + align:start position:0% +of this operator and then do some + + + align:start position:0% +of this operator and then do some +normalization group evolution of that of + + align:start position:0% +normalization group evolution of that of + + + align:start position:0% +normalization group evolution of that of +wilson coefficient + + align:start position:0% + + + + align:start position:0% + +well let's just think about computing + + align:start position:0% +well let's just think about computing + + + align:start position:0% +well let's just think about computing +the graphs + + align:start position:0% + + + + align:start position:0% + +so we have to decide when we compute the + + align:start position:0% +so we have to decide when we compute the + + + align:start position:0% +so we have to decide when we compute the +graphs how to regulate them + + align:start position:0% +graphs how to regulate them + + + align:start position:0% +graphs how to regulate them +right we're going to and we need to use + + align:start position:0% +right we're going to and we need to use + + + align:start position:0% +right we're going to and we need to use +the same infrared regulator in the full + + align:start position:0% +the same infrared regulator in the full + + + align:start position:0% +the same infrared regulator in the full +theory of defective theory + + align:start position:0% +theory of defective theory + + + align:start position:0% +theory of defective theory +so here's how i'm going to regulate them + + align:start position:0% +so here's how i'm going to regulate them + + + align:start position:0% +so here's how i'm going to regulate them +we could do this different ways and it's + + align:start position:0% +we could do this different ways and it's + + + align:start position:0% +we could do this different ways and it's +useful to understand that + + align:start position:0% +useful to understand that + + + align:start position:0% +useful to understand that +various answers that we get are + + align:start position:0% +various answers that we get are + + + align:start position:0% +various answers that we get are +independent of the regulator + + align:start position:0% + + + + align:start position:0% + +so i'm going to take p squared not equal + + align:start position:0% +so i'm going to take p squared not equal + + + align:start position:0% +so i'm going to take p squared not equal +to zero for the strange quark + + align:start position:0% + + + + align:start position:0% + +so there's infrared divergences + + align:start position:0% +so there's infrared divergences + + + align:start position:0% +so there's infrared divergences +associated to the strange quark and i'm + + align:start position:0% +associated to the strange quark and i'm + + + align:start position:0% +associated to the strange quark and i'm +going to + + align:start position:0% +going to + + + align:start position:0% +going to +take p squared not equal to 0 for them + + align:start position:0% +take p squared not equal to 0 for them + + + align:start position:0% +take p squared not equal to 0 for them +i'm going to use dim rag + + align:start position:0% +i'm going to use dim rag + + + align:start position:0% +i'm going to use dim rag +for the heavy clark + + align:start position:0% + + + + align:start position:0% + +so i could take the b quark to also be + + align:start position:0% +so i could take the b quark to also be + + + align:start position:0% +so i could take the b quark to also be +off shell that would make the formulas + + align:start position:0% +off shell that would make the formulas + + + align:start position:0% +off shell that would make the formulas +even more complicated so instead of + + align:start position:0% +even more complicated so instead of + + + align:start position:0% +even more complicated so instead of +doing that i'm just going to allow + + align:start position:0% +doing that i'm just going to allow + + + align:start position:0% +doing that i'm just going to allow +epsilon to regulate the b cork these + + align:start position:0% +epsilon to regulate the b cork these + + + align:start position:0% +epsilon to regulate the b cork these +guys are pretty easy to track so + + align:start position:0% +guys are pretty easy to track so + + + align:start position:0% +guys are pretty easy to track so +that won't + + align:start position:0% +that won't + + + align:start position:0% +that won't +be a problem + + align:start position:0% +be a problem + + + align:start position:0% +be a problem +and i'm going to use feinman gauge + + align:start position:0% + + + + align:start position:0% + +i don't have to do that but + + align:start position:0% +i don't have to do that but + + + align:start position:0% +i don't have to do that but +that's a nice gauge for doing + + align:start position:0% +that's a nice gauge for doing + + + align:start position:0% +that's a nice gauge for doing +calculations + + align:start position:0% +calculations + + + align:start position:0% +calculations +so what are the diagrams where i have my + + align:start position:0% +so what are the diagrams where i have my + + + align:start position:0% +so what are the diagrams where i have my +photon + + align:start position:0% +photon + + + align:start position:0% +photon +and i have a vertex + + align:start position:0% +and i have a vertex + + + align:start position:0% +and i have a vertex +diagram like this + + align:start position:0% +diagram like this + + + align:start position:0% +diagram like this +and then i have wave function or + + align:start position:0% +and then i have wave function or + + + align:start position:0% +and then i have wave function or +normalization and so + + align:start position:0% +normalization and so + + + align:start position:0% +normalization and so +let me in the usual kind of cavalier way + + align:start position:0% +let me in the usual kind of cavalier way + + + align:start position:0% +let me in the usual kind of cavalier way +denote the wave function or + + align:start position:0% +denote the wave function or + + + align:start position:0% +denote the wave function or +normalization + + align:start position:0% +normalization + + + align:start position:0% +normalization +which is just the multiplication by the + + align:start position:0% +which is just the multiplication by the + + + align:start position:0% +which is just the multiplication by the +appropriate z factors + + align:start position:0% +appropriate z factors + + + align:start position:0% +appropriate z factors +by diagrams like that + + align:start position:0% + + + + align:start position:0% + +and this is a standard qcd calculation + + align:start position:0% +and this is a standard qcd calculation + + + align:start position:0% +and this is a standard qcd calculation +and we can + + align:start position:0% +and we can + + + align:start position:0% +and we can +carry it out + + align:start position:0% + + + + align:start position:0% + +and what does the answer look like + + align:start position:0% + + + + align:start position:0% + +so this diagram + + align:start position:0% +so this diagram + + + align:start position:0% +so this diagram +here + + align:start position:0% + + + + align:start position:0% + +has double logs + + align:start position:0% + + + + align:start position:0% + +and single logs + + align:start position:0% + + + + align:start position:0% + +that involve p squared which is our ir + + align:start position:0% +that involve p squared which is our ir + + + align:start position:0% +that involve p squared which is our ir +regulator + + align:start position:0% +regulator + + + align:start position:0% +regulator +and then it has + + align:start position:0% +and then it has + + + align:start position:0% +and then it has +some terms that are finite + + align:start position:0% +some terms that are finite + + + align:start position:0% +some terms that are finite +which i'll just denote by + + align:start position:0% +which i'll just denote by + + + align:start position:0% +which i'll just denote by +so p here is the momentum of our strange + + align:start position:0% +so p here is the momentum of our strange + + + align:start position:0% +so p here is the momentum of our strange +quark going out + + align:start position:0% +quark going out + + + align:start position:0% +quark going out +and + + align:start position:0% +and + + + align:start position:0% +and +pb is the momentum of our v quark coming + + align:start position:0% +pb is the momentum of our v quark coming + + + align:start position:0% +pb is the momentum of our v quark coming +in + + align:start position:0% +in + + + align:start position:0% +in +and let me not try to + + align:start position:0% +and let me not try to + + + align:start position:0% +and let me not try to +we're not going to talk much about these + + align:start position:0% +we're not going to talk much about these + + + align:start position:0% +we're not going to talk much about these +finite terms but there is some + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% + + + + align:start position:0% + +terms + + align:start position:0% +terms + + + align:start position:0% +terms +with + + align:start position:0% +with + + + align:start position:0% +with +what i mean by finite here is terms with + + align:start position:0% +what i mean by finite here is terms with + + + align:start position:0% +what i mean by finite here is terms with +no i are divergences + + align:start position:0% +no i are divergences + + + align:start position:0% +no i are divergences +so the ir divergences are these single + + align:start position:0% +so the ir divergences are these single + + + align:start position:0% +so the ir divergences are these single +logs and double logs and then there's + + align:start position:0% +logs and double logs and then there's + + + align:start position:0% +logs and double logs and then there's +some + + align:start position:0% +some + + + align:start position:0% +some +some remainder that i can write that way + + align:start position:0% +some remainder that i can write that way + + + align:start position:0% +some remainder that i can write that way +i'm expanding for small p squared so p + + align:start position:0% +i'm expanding for small p squared so p + + + align:start position:0% +i'm expanding for small p squared so p +squared is not equal to zero but i take + + align:start position:0% +squared is not equal to zero but i take + + + align:start position:0% +squared is not equal to zero but i take +the limit p squared goes to zero and + + align:start position:0% +the limit p squared goes to zero and + + + align:start position:0% +the limit p squared goes to zero and +then that limit these are the ir + + align:start position:0% +then that limit these are the ir + + + align:start position:0% +then that limit these are the ir +singularities and then there's + + align:start position:0% +singularities and then there's + + + align:start position:0% +singularities and then there's +some function of p dot p + + align:start position:0% +some function of p dot p + + + align:start position:0% +some function of p dot p +b which is just an order one thing and + + align:start position:0% +b which is just an order one thing and + + + align:start position:0% +b which is just an order one thing and +then b squared of course is p b squared + + align:start position:0% +then b squared of course is p b squared + + + align:start position:0% +then b squared of course is p b squared +so that's sort of the remaining + + align:start position:0% +so that's sort of the remaining + + + align:start position:0% +so that's sort of the remaining +kinematic variables this could possibly + + align:start position:0% +kinematic variables this could possibly + + + align:start position:0% +kinematic variables this could possibly +depend on + + align:start position:0% + + + + align:start position:0% + +no + + align:start position:0% + + + + align:start position:0% + +it's really finite there's no + + align:start position:0% +it's really finite there's no + + + align:start position:0% +it's really finite there's no +so + + align:start position:0% +so + + + align:start position:0% +so +yeah um + + align:start position:0% +yeah um + + + align:start position:0% +yeah um +yeah so i let's see i uh + + align:start position:0% +yeah so i let's see i uh + + + align:start position:0% +yeah so i let's see i uh +yeah i guess i carried out the so there + + align:start position:0% +yeah i guess i carried out the so there + + + align:start position:0% +yeah i guess i carried out the so there +is a z-10 for the tensor + + align:start position:0% +is a z-10 for the tensor + + + align:start position:0% +is a z-10 for the tensor +and when i write this + + align:start position:0% + + + + align:start position:0% + +yeah let's see + + align:start position:0% + + + + align:start position:0% + +so okay + + align:start position:0% + + + + align:start position:0% + +let me do this + + align:start position:0% +let me do this + + + align:start position:0% +let me do this +i think it's better so i added up all + + align:start position:0% +i think it's better so i added up all + + + align:start position:0% +i think it's better so i added up all +these graphs and i want to add one more + + align:start position:0% +these graphs and i want to add one more + + + align:start position:0% +these graphs and i want to add one more +just + + align:start position:0% + + + + align:start position:0% + +so there's a there's a counter term for + + align:start position:0% +so there's a there's a counter term for + + + align:start position:0% +so there's a there's a counter term for +the tensor field + + align:start position:0% + + + + align:start position:0% + +so let me add up let me change what i + + align:start position:0% +so let me add up let me change what i + + + align:start position:0% +so let me add up let me change what i +was going to say and do it this way so + + align:start position:0% +was going to say and do it this way so + + + align:start position:0% +was going to say and do it this way so +the sum of these four graphs is this + + align:start position:0% +the sum of these four graphs is this + + + align:start position:0% +the sum of these four graphs is this +okay so then if there's no uv + + align:start position:0% +okay so then if there's no uv + + + align:start position:0% +okay so then if there's no uv +divergences and i'll just tell you what + + align:start position:0% +divergences and i'll just tell you what + + + align:start position:0% +divergences and i'll just tell you what +the z factors for these three are then + + align:start position:0% +the z factors for these three are then + + + align:start position:0% +the z factors for these three are then +you could figure out what this graph is + + align:start position:0% +you could figure out what this graph is + + + align:start position:0% +you could figure out what this graph is +but subtract the two + + align:start position:0% + + + + align:start position:0% + +so the tensor current in qcd + + align:start position:0% +so the tensor current in qcd + + + align:start position:0% +so the tensor current in qcd +has a + + align:start position:0% +has a + + + align:start position:0% +has a +has a z factor + + align:start position:0% +has a z factor + + + align:start position:0% +has a z factor +it looks like that + + align:start position:0% + + + + align:start position:0% + +there's a z + + align:start position:0% +there's a z + + + align:start position:0% +there's a z +for the + + align:start position:0% + + + + align:start position:0% + +heavy cork + + align:start position:0% +heavy cork + + + align:start position:0% +heavy cork +and if i include the finite residue as + + align:start position:0% +and if i include the finite residue as + + + align:start position:0% +and if i include the finite residue as +well as the divergent pieces + + align:start position:0% + + + + align:start position:0% + +this looks like this + + align:start position:0% + + + + align:start position:0% + +i think i'm going to have to make one + + align:start position:0% +i think i'm going to have to make one + + + align:start position:0% +i think i'm going to have to make one +adjustment to my formula here + + align:start position:0% + + + + align:start position:0% + +let's fix something here + + align:start position:0% +let's fix something here + + + align:start position:0% +let's fix something here +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +so if i want it to be the way i say + + align:start position:0% +so if i want it to be the way i say + + + align:start position:0% +so if i want it to be the way i say +then + + align:start position:0% +then + + + align:start position:0% +then +do i have to do so this guy should be + + align:start position:0% +do i have to do so this guy should be + + + align:start position:0% +do i have to do so this guy should be +three + + align:start position:0% + + + + align:start position:0% + +halves and + + align:start position:0% +halves and + + + align:start position:0% +halves and +there will be one + + align:start position:0% +there will be one + + + align:start position:0% +there will be one +more divergence + + align:start position:0% + + + + align:start position:0% + +i think that's right + + align:start position:0% +i think that's right + + + align:start position:0% +i think that's right +so this 2 over epsilon ir here + + align:start position:0% +so this 2 over epsilon ir here + + + align:start position:0% +so this 2 over epsilon ir here +is that one over epsilon i r + + align:start position:0% +is that one over epsilon i r + + + align:start position:0% +is that one over epsilon i r +and the uv renormalization is taken care + + align:start position:0% +and the uv renormalization is taken care + + + align:start position:0% +and the uv renormalization is taken care +of once i have the z tensor that there's + + align:start position:0% +of once i have the z tensor that there's + + + align:start position:0% +of once i have the z tensor that there's +z there's divergences in this diagram + + align:start position:0% +z there's divergences in this diagram + + + align:start position:0% +z there's divergences in this diagram +and these ones but there's one left over + + align:start position:0% +and these ones but there's one left over + + + align:start position:0% +and these ones but there's one left over +and that's taken care of by z tensor so + + align:start position:0% +and that's taken care of by z tensor so + + + align:start position:0% +and that's taken care of by z tensor so +there's no one over epsilon uvs after i + + align:start position:0% +there's no one over epsilon uvs after i + + + align:start position:0% +there's no one over epsilon uvs after i +after i take care of + + align:start position:0% +after i take care of + + + align:start position:0% +after i take care of +this guy + + align:start position:0% + + + + align:start position:0% + +okay so that's just + + align:start position:0% +okay so that's just + + + align:start position:0% +okay so that's just +kind of by the definition of what z + + align:start position:0% +kind of by the definition of what z + + + align:start position:0% +kind of by the definition of what z +tensor should be + + align:start position:0% +tensor should be + + + align:start position:0% +tensor should be +and then everything else is as i wrote + + align:start position:0% + + + + align:start position:0% + +so there's ir divergences that are + + align:start position:0% +so there's ir divergences that are + + + align:start position:0% +so there's ir divergences that are +associated to the strange quark off + + align:start position:0% +associated to the strange quark off + + + align:start position:0% +associated to the strange quark off +shellness that's these two terms there's + + align:start position:0% +shellness that's these two terms there's + + + align:start position:0% +shellness that's these two terms there's +an iron divergence associated the heavy + + align:start position:0% +an iron divergence associated the heavy + + + align:start position:0% +an iron divergence associated the heavy +quark going on shell that's that term + + align:start position:0% +quark going on shell that's that term + + + align:start position:0% +quark going on shell that's that term +that's the sum of diagrams + + align:start position:0% + + + + align:start position:0% + +okay so what about sct + + align:start position:0% + + + + align:start position:0% + +so there's going to be an sct linear + + align:start position:0% +so there's going to be an sct linear + + + align:start position:0% +so there's going to be an sct linear +diagrams and + + align:start position:0% +diagrams and + + + align:start position:0% +diagrams and +ultrasoft diagrams + + align:start position:0% + + + + align:start position:0% + +so i'm going to use fine engage for + + align:start position:0% +so i'm going to use fine engage for + + + align:start position:0% +so i'm going to use fine engage for +everything again + + align:start position:0% + + + + align:start position:0% + +this is not something i have to do + + align:start position:0% +this is not something i have to do + + + align:start position:0% +this is not something i have to do +this is what i'm going to do + + align:start position:0% + + + + align:start position:0% + +let's start with the ultra soft loops + + align:start position:0% + + + + align:start position:0% + +so there's a vertex graph + + align:start position:0% + + + + align:start position:0% + +so using + + align:start position:0% +so using + + + align:start position:0% +so using +the notation that we've adopted + + align:start position:0% +the notation that we've adopted + + + align:start position:0% +the notation that we've adopted +where the linear quarks are + + align:start position:0% +where the linear quarks are + + + align:start position:0% +where the linear quarks are +dashed and the heavy forks are double + + align:start position:0% +dashed and the heavy forks are double + + + align:start position:0% +dashed and the heavy forks are double +lines we have a diagram that looks like + + align:start position:0% +lines we have a diagram that looks like + + + align:start position:0% +lines we have a diagram that looks like +that + + align:start position:0% +that + + + align:start position:0% +that +there's some pre-factor + + align:start position:0% +there's some pre-factor + + + align:start position:0% +there's some pre-factor +let's focus on what the loop integral + + align:start position:0% +let's focus on what the loop integral + + + align:start position:0% +let's focus on what the loop integral +looks like + + align:start position:0% +looks like + + + align:start position:0% +looks like +so this loop here the k that's going + + align:start position:0% +so this loop here the k that's going + + + align:start position:0% +so this loop here the k that's going +through this loop + + align:start position:0% +through this loop + + + align:start position:0% +through this loop +is just a residual + + align:start position:0% +is just a residual + + + align:start position:0% +is just a residual +k there's no label k for this loop + + align:start position:0% +k there's no label k for this loop + + + align:start position:0% +k there's no label k for this loop +because it's an ultrasoft gluon + + align:start position:0% +because it's an ultrasoft gluon + + + align:start position:0% +because it's an ultrasoft gluon +so when we write down + + align:start position:0% +so when we write down + + + align:start position:0% +so when we write down +all the terms in this loop it's just + + align:start position:0% +all the terms in this loop it's just + + + align:start position:0% +all the terms in this loop it's just +standard field theory there's nothing + + align:start position:0% +standard field theory there's nothing + + + align:start position:0% +standard field theory there's nothing +special about + + align:start position:0% + + + + align:start position:0% + +it since i'm taking + + align:start position:0% +it since i'm taking + + + align:start position:0% +it since i'm taking +the strange quark off shell + + align:start position:0% + + + + align:start position:0% + +the propagator that i get is this + + align:start position:0% +the propagator that i get is this + + + align:start position:0% +the propagator that i get is this +shifted icon propagator where the + + align:start position:0% +shifted icon propagator where the + + + align:start position:0% +shifted icon propagator where the +basically the fact that it's off shell + + align:start position:0% +basically the fact that it's off shell + + + align:start position:0% +basically the fact that it's off shell +gives me this + + align:start position:0% +gives me this + + + align:start position:0% +gives me this +extra term there that's regulating some + + align:start position:0% +extra term there that's regulating some + + + align:start position:0% +extra term there that's regulating some +ir divergences and we want that because + + align:start position:0% +ir divergences and we want that because + + + align:start position:0% +ir divergences and we want that because +we want to regulate the iron divergences + + align:start position:0% +we want to regulate the iron divergences + + + align:start position:0% +we want to regulate the iron divergences +in the same way in the full theory and + + align:start position:0% +in the same way in the full theory and + + + align:start position:0% +in the same way in the full theory and +the effective theory + + align:start position:0% + + + + align:start position:0% + +this is proportional to that + + align:start position:0% +this is proportional to that + + + align:start position:0% +this is proportional to that +and if i put in all the factors + + align:start position:0% + + + + align:start position:0% + +so it does have double logs + + align:start position:0% +so it does have double logs + + + align:start position:0% +so it does have double logs +of the p squared + + align:start position:0% +of the p squared + + + align:start position:0% +of the p squared +it doesn't have single logs of the p + + align:start position:0% +it doesn't have single logs of the p + + + align:start position:0% +it doesn't have single logs of the p +squared + + align:start position:0% +squared + + + align:start position:0% +squared +and actually if we look at the double + + align:start position:0% +and actually if we look at the double + + + align:start position:0% +and actually if we look at the double +logs the coefficients also don't match + + align:start position:0% +logs the coefficients also don't match + + + align:start position:0% +logs the coefficients also don't match +with what we had over there and + + align:start position:0% + + + + align:start position:0% + +so there's going to be some other + + align:start position:0% +so there's going to be some other + + + align:start position:0% +so there's going to be some other +diagrams that are going to involve + + align:start position:0% +diagrams that are going to involve + + + align:start position:0% +diagrams that are going to involve +double logs of p squared as well + + align:start position:0% +double logs of p squared as well + + + align:start position:0% +double logs of p squared as well +one thing that we can note here is that + + align:start position:0% +one thing that we can note here is that + + + align:start position:0% +one thing that we can note here is that +if you think about the scales in the + + align:start position:0% +if you think about the scales in the + + + align:start position:0% +if you think about the scales in the +problem + + align:start position:0% +problem + + + align:start position:0% +problem +remember that our loop integral is + + align:start position:0% +remember that our loop integral is + + + align:start position:0% +remember that our loop integral is +totally homogeneous in the power + + align:start position:0% +totally homogeneous in the power + + + align:start position:0% +totally homogeneous in the power +counting lambdas were totally + + align:start position:0% +counting lambdas were totally + + + align:start position:0% +counting lambdas were totally +homogeneous + + align:start position:0% +homogeneous + + + align:start position:0% +homogeneous +and if you think about p squared + + align:start position:0% +and if you think about p squared + + + align:start position:0% +and if you think about p squared +as scaling like lambda squared + + align:start position:0% +as scaling like lambda squared + + + align:start position:0% +as scaling like lambda squared +which is natural size for an external + + align:start position:0% +which is natural size for an external + + + align:start position:0% +which is natural size for an external +linear momentum + + align:start position:0% +linear momentum + + + align:start position:0% +linear momentum +right + + align:start position:0% +right + + + align:start position:0% +right +if p squared squared is like lambda + + align:start position:0% +if p squared squared is like lambda + + + align:start position:0% +if p squared squared is like lambda +squared then + + align:start position:0% +squared then + + + align:start position:0% +squared then +so does + + align:start position:0% +so does + + + align:start position:0% +so does +p squared over m bar dot p + + align:start position:0% + + + + align:start position:0% + +and this is a dimension one thing and + + align:start position:0% +and this is a dimension one thing and + + + align:start position:0% +and this is a dimension one thing and +this is the ultrasoft scale right + + align:start position:0% + + + + align:start position:0% + +for + + align:start position:0% +for + + + align:start position:0% +for +some + + align:start position:0% +some + + + align:start position:0% +some +ultrasoft momentum + + align:start position:0% +ultrasoft momentum + + + align:start position:0% +ultrasoft momentum +and so + + align:start position:0% +and so + + + align:start position:0% +and so +if you want to look at these logarithms + + align:start position:0% +if you want to look at these logarithms + + + align:start position:0% +if you want to look at these logarithms +and you ask what scale is this effective + + align:start position:0% +and you ask what scale is this effective + + + align:start position:0% +and you ask what scale is this effective +field of theory diagram + + align:start position:0% +field of theory diagram + + + align:start position:0% +field of theory diagram +sensitive to it's sensitive to the + + align:start position:0% +sensitive to it's sensitive to the + + + align:start position:0% +sensitive to it's sensitive to the +ultrasound scale + + align:start position:0% + + + + align:start position:0% + +so the logs are not large logs they're + + align:start position:0% +so the logs are not large logs they're + + + align:start position:0% +so the logs are not large logs they're +order one logs + + align:start position:0% +order one logs + + + align:start position:0% +order one logs +as long as mu squared mu is + + align:start position:0% +as long as mu squared mu is + + + align:start position:0% +as long as mu squared mu is +of order lambda squared which is the + + align:start position:0% +of order lambda squared which is the + + + align:start position:0% +of order lambda squared which is the +scale for the for ultrasoft momentum and + + align:start position:0% +scale for the for ultrasoft momentum and + + + align:start position:0% +scale for the for ultrasoft momentum and +that's what we expect from this ultra + + align:start position:0% +that's what we expect from this ultra + + + align:start position:0% +that's what we expect from this ultra +soft diagram that it's telling us about + + align:start position:0% +soft diagram that it's telling us about + + + align:start position:0% +soft diagram that it's telling us about +physics at the ultrasoft scale and + + align:start position:0% +physics at the ultrasoft scale and + + + align:start position:0% +physics at the ultrasoft scale and +that's what we see + + align:start position:0% +that's what we see + + + align:start position:0% +that's what we see +from setting things up + + align:start position:0% +from setting things up + + + align:start position:0% +from setting things up +doing the calculation + + align:start position:0% + + + + align:start position:0% + +so you could also think about a wave + + align:start position:0% +so you could also think about a wave + + + align:start position:0% +so you could also think about a wave +function diagram with an ultrasoft gluon + + align:start position:0% +function diagram with an ultrasoft gluon + + + align:start position:0% +function diagram with an ultrasoft gluon +but this guy's zero + + align:start position:0% +but this guy's zero + + + align:start position:0% +but this guy's zero +since in feynman gage + + align:start position:0% +since in feynman gage + + + align:start position:0% +since in feynman gage +you just get n mu n mu which is zero + + align:start position:0% +you just get n mu n mu which is zero + + + align:start position:0% +you just get n mu n mu which is zero +so there's no + + align:start position:0% +so there's no + + + align:start position:0% +so there's no +so + + align:start position:0% +so + + + align:start position:0% +so +z for the + + align:start position:0% +z for the + + + align:start position:0% +z for the +linear quark field from an ultra soft + + align:start position:0% +linear quark field from an ultra soft + + + align:start position:0% +linear quark field from an ultra soft +loop is zero + + align:start position:0% +loop is zero + + + align:start position:0% +loop is zero +that wouldn't necessarily be true in + + align:start position:0% +that wouldn't necessarily be true in + + + align:start position:0% +that wouldn't necessarily be true in +some other gauge and some but in some + + align:start position:0% +some other gauge and some but in some + + + align:start position:0% +some other gauge and some but in some +other gauge this diagram would also + + align:start position:0% +other gauge this diagram would also + + + align:start position:0% +other gauge this diagram would also +change all the diagrams would change and + + align:start position:0% +change all the diagrams would change and + + + align:start position:0% +change all the diagrams would change and +so if there was a non-zero contribution + + align:start position:0% +so if there was a non-zero contribution + + + align:start position:0% +so if there was a non-zero contribution +in this diagram it would just be taken + + align:start position:0% +in this diagram it would just be taken + + + align:start position:0% +in this diagram it would just be taken +care of gauge invariants + + align:start position:0% + + + + align:start position:0% + +and then finally + + align:start position:0% + + + + align:start position:0% + +there's ultrasoft loop on the heavy + + align:start position:0% +there's ultrasoft loop on the heavy + + + align:start position:0% +there's ultrasoft loop on the heavy +quark + + align:start position:0% +quark + + + align:start position:0% +quark +and that actually just gives us that's + + align:start position:0% +and that actually just gives us that's + + + align:start position:0% +and that actually just gives us that's +an hqt diagram has nothing to do with + + align:start position:0% +an hqt diagram has nothing to do with + + + align:start position:0% +an hqt diagram has nothing to do with +the clinical quark + + align:start position:0% +the clinical quark + + + align:start position:0% +the clinical quark +so from that diagram we would just get + + align:start position:0% +so from that diagram we would just get + + + align:start position:0% +so from that diagram we would just get +the z factor + + align:start position:0% + + + + align:start position:0% + +which is the appropriate z factoring + + align:start position:0% +which is the appropriate z factoring + + + align:start position:0% +which is the appropriate z factoring +hqet + + align:start position:0% + + + + align:start position:0% + +with r regulator + + align:start position:0% +with r regulator + + + align:start position:0% +with r regulator +if i specify ultraviolet and infrared + + align:start position:0% +if i specify ultraviolet and infrared + + + align:start position:0% +if i specify ultraviolet and infrared +divergences that's this + + align:start position:0% +divergences that's this + + + align:start position:0% +divergences that's this +and this infrared divergence here is + + align:start position:0% +and this infrared divergence here is + + + align:start position:0% +and this infrared divergence here is +actually exactly the same as the one + + align:start position:0% +actually exactly the same as the one + + + align:start position:0% +actually exactly the same as the one +that we had + + align:start position:0% +that we had + + + align:start position:0% +that we had +over here + + align:start position:0% + + + + align:start position:0% + +okay so the ultrasoft sector is really + + align:start position:0% +okay so the ultrasoft sector is really + + + align:start position:0% +okay so the ultrasoft sector is really +just there's nothing really tricky about + + align:start position:0% +just there's nothing really tricky about + + + align:start position:0% +just there's nothing really tricky about +it it's just write down the diagrams do + + align:start position:0% +it it's just write down the diagrams do + + + align:start position:0% +it it's just write down the diagrams do +the loops + + align:start position:0% + + + + align:start position:0% + +isn't that like uh higher emergencies of + + align:start position:0% +isn't that like uh higher emergencies of + + + align:start position:0% +isn't that like uh higher emergencies of +those diagrams cancer without we never + + align:start position:0% +those diagrams cancer without we never + + + align:start position:0% +those diagrams cancer without we never +really ever mentioned elevators or for + + align:start position:0% +really ever mentioned elevators or for + + + align:start position:0% +really ever mentioned elevators or for +the initial variable + + align:start position:0% +the initial variable + + + align:start position:0% +the initial variable +um it depends so what are we looking at + + align:start position:0% +um it depends so what are we looking at + + + align:start position:0% +um it depends so what are we looking at +right so it depends on what we're + + align:start position:0% +right so it depends on what we're + + + align:start position:0% +right so it depends on what we're +looking at at here + + align:start position:0% +looking at at here + + + align:start position:0% +looking at at here +and what i'm doing + + align:start position:0% +and what i'm doing + + + align:start position:0% +and what i'm doing +so yes in general that would be true + + align:start position:0% +so yes in general that would be true + + + align:start position:0% +so yes in general that would be true +right if you were calculating some cross + + align:start position:0% +right if you were calculating some cross + + + align:start position:0% +right if you were calculating some cross +section which was ir finite cross + + align:start position:0% +section which was ir finite cross + + + align:start position:0% +section which was ir finite cross +section and + + align:start position:0% +section and + + + align:start position:0% +section and +you that of course would depend on + + align:start position:0% +you that of course would depend on + + + align:start position:0% +you that of course would depend on +defining what you mean by measuring this + + align:start position:0% +defining what you mean by measuring this + + + align:start position:0% +defining what you mean by measuring this +quark + + align:start position:0% +quark + + + align:start position:0% +quark +right so the ir divergence would become + + align:start position:0% +right so the ir divergence would become + + + align:start position:0% +right so the ir divergence would become +some physical scale like you know the + + align:start position:0% +some physical scale like you know the + + + align:start position:0% +some physical scale like you know the +mass of the jet or the + + align:start position:0% +mass of the jet or the + + + align:start position:0% +mass of the jet or the +some some something the ir divergences + + align:start position:0% +some some something the ir divergences + + + align:start position:0% +some some something the ir divergences +would turn into something physical right + + align:start position:0% +would turn into something physical right + + + align:start position:0% +would turn into something physical right +if you put this into a physical cross + + align:start position:0% +if you put this into a physical cross + + + align:start position:0% +if you put this into a physical cross +section + + align:start position:0% +section + + + align:start position:0% +section +um + + align:start position:0% +um + + + align:start position:0% +um +and that's exactly basically what would + + align:start position:0% +and that's exactly basically what would + + + align:start position:0% +and that's exactly basically what would +happen these p squares would become sort + + align:start position:0% +happen these p squares would become sort + + + align:start position:0% +happen these p squares would become sort +of the mx squareds that we talked about + + align:start position:0% +of the mx squareds that we talked about + + + align:start position:0% +of the mx squareds that we talked about +when we talked about + + align:start position:0% +when we talked about + + + align:start position:0% +when we talked about +bds gamma + + align:start position:0% +bds gamma + + + align:start position:0% +bds gamma +but here what we're interested in doing + + align:start position:0% +but here what we're interested in doing + + + align:start position:0% +but here what we're interested in doing +is a matching calculation so we fix + + align:start position:0% +is a matching calculation so we fix + + + align:start position:0% +is a matching calculation so we fix +the external states to have a particular + + align:start position:0% +the external states to have a particular + + + align:start position:0% +the external states to have a particular +number of protons + + align:start position:0% +number of protons + + + align:start position:0% +number of protons +and we want to compare the full theory + + align:start position:0% +and we want to compare the full theory + + + align:start position:0% +and we want to compare the full theory +calculation of the effective theory the + + align:start position:0% +calculation of the effective theory the + + + align:start position:0% +calculation of the effective theory the +effect of theory should reproduce the + + align:start position:0% +effect of theory should reproduce the + + + align:start position:0% +effect of theory should reproduce the +infrared divergences + + align:start position:0% +infrared divergences + + + align:start position:0% +infrared divergences +so really all we care about is not that + + align:start position:0% +so really all we care about is not that + + + align:start position:0% +so really all we care about is not that +this is infrared finite + + align:start position:0% +this is infrared finite + + + align:start position:0% +this is infrared finite +but rather that it's got the right + + align:start position:0% +but rather that it's got the right + + + align:start position:0% +but rather that it's got the right +infra the effective theory has the same + + align:start position:0% +infra the effective theory has the same + + + align:start position:0% +infra the effective theory has the same +infrared divergences + + align:start position:0% +infrared divergences + + + align:start position:0% +infrared divergences +and we'll see that in the end what you + + align:start position:0% +and we'll see that in the end what you + + + align:start position:0% +and we'll see that in the end what you +can think about is rather than canceling + + align:start position:0% +can think about is rather than canceling + + + align:start position:0% +can think about is rather than canceling +infrared divergences as you're thinking + + align:start position:0% +infrared divergences as you're thinking + + + align:start position:0% +infrared divergences as you're thinking +in the full theory we've matched the + + align:start position:0% +in the full theory we've matched the + + + align:start position:0% +in the full theory we've matched the +full theory onto the effective theory + + align:start position:0% +full theory onto the effective theory + + + align:start position:0% +full theory onto the effective theory +and that matching gives us the wilson + + align:start position:0% +and that matching gives us the wilson + + + align:start position:0% +and that matching gives us the wilson +coefficient + + align:start position:0% +coefficient + + + align:start position:0% +coefficient +and then we take the effect of theory + + align:start position:0% +and then we take the effect of theory + + + align:start position:0% +and then we take the effect of theory +and all the cancellations that you're + + align:start position:0% +and all the cancellations that you're + + + align:start position:0% +and all the cancellations that you're +thinking about between real and virtual + + align:start position:0% +thinking about between real and virtual + + + align:start position:0% +thinking about between real and virtual +graphs will occur in the effective + + align:start position:0% +graphs will occur in the effective + + + align:start position:0% +graphs will occur in the effective +theory too + + align:start position:0% +theory too + + + align:start position:0% +theory too +so you can just think about the + + align:start position:0% +so you can just think about the + + + align:start position:0% +so you can just think about the +effective theory virtual real graphs and + + align:start position:0% +effective theory virtual real graphs and + + + align:start position:0% +effective theory virtual real graphs and +then the cancellation will take place + + align:start position:0% +then the cancellation will take place + + + align:start position:0% +then the cancellation will take place +there + + align:start position:0% +there + + + align:start position:0% +there +but that then you're thinking about that + + align:start position:0% +but that then you're thinking about that + + + align:start position:0% +but that then you're thinking about that +cancellation later at a lower scale + + align:start position:0% +cancellation later at a lower scale + + + align:start position:0% +cancellation later at a lower scale +which is what you actually want to do + + align:start position:0% +which is what you actually want to do + + + align:start position:0% +which is what you actually want to do +because + + align:start position:0% +because + + + align:start position:0% +because +what i just was telling you about ir + + align:start position:0% +what i just was telling you about ir + + + align:start position:0% +what i just was telling you about ir +divergences becoming + + align:start position:0% +divergences becoming + + + align:start position:0% +divergences becoming +different things in the effect in the + + align:start position:0% +different things in the effect in the + + + align:start position:0% +different things in the effect in the +final state becomes very trivial once + + align:start position:0% +final state becomes very trivial once + + + align:start position:0% +final state becomes very trivial once +you're in the effective theory + + align:start position:0% +you're in the effective theory + + + align:start position:0% +you're in the effective theory +and we'll see sort of exactly how that + + align:start position:0% +and we'll see sort of exactly how that + + + align:start position:0% +and we'll see sort of exactly how that +works + + align:start position:0% +works + + + align:start position:0% +works +later on + + align:start position:0% +later on + + + align:start position:0% +later on +but first + + align:start position:0% +but first + + + align:start position:0% +but first +we have to + + align:start position:0% +we have to + + + align:start position:0% +we have to +talk about linear graphs + + align:start position:0% + + + + align:start position:0% + +so in the linear graphs we had graphs + + align:start position:0% +so in the linear graphs we had graphs + + + align:start position:0% +so in the linear graphs we had graphs +like this one where we could take a + + align:start position:0% +like this one where we could take a + + + align:start position:0% +like this one where we could take a +gluon out of the out of the + + align:start position:0% +gluon out of the out of the + + + align:start position:0% +gluon out of the out of the +vertex here that corresponds to taking + + align:start position:0% +vertex here that corresponds to taking + + + align:start position:0% +vertex here that corresponds to taking +it out of the wilson line + + align:start position:0% +it out of the wilson line + + + align:start position:0% +it out of the wilson line +so let's label the graph in the + + align:start position:0% +so let's label the graph in the + + + align:start position:0% +so let's label the graph in the +following way this will be k plus p this + + align:start position:0% +following way this will be k plus p this + + + align:start position:0% +following way this will be k plus p this +will be p + + align:start position:0% +will be p + + + align:start position:0% +will be p +this will be k + + align:start position:0% +this will be k + + + align:start position:0% +this will be k +and if we follow our rules for what this + + align:start position:0% +and if we follow our rules for what this + + + align:start position:0% +and if we follow our rules for what this +is + + align:start position:0% +is + + + align:start position:0% +is +we would write a sum + + align:start position:0% +we would write a sum + + + align:start position:0% +we would write a sum +over labels + + align:start position:0% + + + + align:start position:0% + +and then an integral over residuals + + align:start position:0% + + + + align:start position:0% + +and let me put the residual integral in + + align:start position:0% +and let me put the residual integral in + + + align:start position:0% +and let me put the residual integral in +dimensional regulation + + align:start position:0% + + + + align:start position:0% + +try to squeeze in everything + + align:start position:0% + + + + align:start position:0% + +which won't be possible but + + align:start position:0% + + + + align:start position:0% + +so i'm going to write out the components + + align:start position:0% +so i'm going to write out the components + + + align:start position:0% +so i'm going to write out the components +to make clear who's the residual and + + align:start position:0% +to make clear who's the residual and + + + align:start position:0% +to make clear who's the residual and +who's label + + align:start position:0% + + + + align:start position:0% + +so in the denominator there's one more + + align:start position:0% +so in the denominator there's one more + + + align:start position:0% +so in the denominator there's one more +term + + align:start position:0% + + + + align:start position:0% + +so the plus guys are always residual the + + align:start position:0% +so the plus guys are always residual the + + + align:start position:0% +so the plus guys are always residual the +curve and the minuses are always labeled + + align:start position:0% +curve and the minuses are always labeled + + + align:start position:0% +curve and the minuses are always labeled +it's + + align:start position:0% +it's + + + align:start position:0% +it's +the short way of saying what i'm trying + + align:start position:0% +the short way of saying what i'm trying + + + align:start position:0% +the short way of saying what i'm trying +to squeeze in here + + align:start position:0% + + + + align:start position:0% + +okay so the denominator has these three + + align:start position:0% +okay so the denominator has these three + + + align:start position:0% +okay so the denominator has these three +terms this guy here this guy here and + + align:start position:0% +terms this guy here this guy here and + + + align:start position:0% +terms this guy here this guy here and +this guy here + + align:start position:0% + + + + align:start position:0% + +and when i label the diagram like this + + align:start position:0% +and when i label the diagram like this + + + align:start position:0% +and when i label the diagram like this +you should think + + align:start position:0% +you should think + + + align:start position:0% +you should think +that each of these + + align:start position:0% + + + + align:start position:0% + +has a label and residual part + + align:start position:0% + + + + align:start position:0% + +so k + + align:start position:0% +so k + + + align:start position:0% +so k +you can think of as a pair k label k + + align:start position:0% +you can think of as a pair k label k + + + align:start position:0% +you can think of as a pair k label k +residual for now + + align:start position:0% +residual for now + + + align:start position:0% +residual for now +and remember the importance of doing + + align:start position:0% +and remember the importance of doing + + + align:start position:0% +and remember the importance of doing +this the importance of doing this was + + align:start position:0% +this the importance of doing this was + + + align:start position:0% +this the importance of doing this was +related to always being able to identify + + align:start position:0% +related to always being able to identify + + + align:start position:0% +related to always being able to identify +what the lowest order term was on the + + align:start position:0% +what the lowest order term was on the + + + align:start position:0% +what the lowest order term was on the +right here + + align:start position:0% +right here + + + align:start position:0% +right here +okay and that actually becomes more + + align:start position:0% +okay and that actually becomes more + + + align:start position:0% +okay and that actually becomes more +important once you start to think about + + align:start position:0% +important once you start to think about + + + align:start position:0% +important once you start to think about +diagrams where + + align:start position:0% +diagrams where + + + align:start position:0% +diagrams where +you would add like an extra ultrasoft + + align:start position:0% +you would add like an extra ultrasoft + + + align:start position:0% +you would add like an extra ultrasoft +gluon somewhere in this picture then + + align:start position:0% +gluon somewhere in this picture then + + + align:start position:0% +gluon somewhere in this picture then +it's + + align:start position:0% +it's + + + align:start position:0% +it's +then of course when that ultra soft glue + + align:start position:0% +then of course when that ultra soft glue + + + align:start position:0% +then of course when that ultra soft glue +on feeds its way through this loop you + + align:start position:0% +on feeds its way through this loop you + + + align:start position:0% +on feeds its way through this loop you +got to make sure that it's only the + + align:start position:0% +got to make sure that it's only the + + + align:start position:0% +got to make sure that it's only the +lowest order piece + + align:start position:0% +lowest order piece + + + align:start position:0% +lowest order piece +that's showing up + + align:start position:0% +that's showing up + + + align:start position:0% +that's showing up +in this case here it's really just we + + align:start position:0% +in this case here it's really just we + + + align:start position:0% +in this case here it's really just we +just have a linear loop + + align:start position:0% +just have a linear loop + + + align:start position:0% +just have a linear loop +and we don't have any sort of + + align:start position:0% +and we don't have any sort of + + + align:start position:0% +and we don't have any sort of +uh + + align:start position:0% +uh + + + align:start position:0% +uh +real ultrasoft momentum from ultrasoft + + align:start position:0% +real ultrasoft momentum from ultrasoft + + + align:start position:0% +real ultrasoft momentum from ultrasoft +particles besides the heavy quark + + align:start position:0% +particles besides the heavy quark + + + align:start position:0% +particles besides the heavy quark +okay + + align:start position:0% +okay + + + align:start position:0% +okay +which is just an external particle to + + align:start position:0% +which is just an external particle to + + + align:start position:0% +which is just an external particle to +the loop + + align:start position:0% +the loop + + + align:start position:0% +the loop +so what we want to do with this is we + + align:start position:0% +so what we want to do with this is we + + + align:start position:0% +so what we want to do with this is we +want to turn it back into an integral + + align:start position:0% + + + + align:start position:0% + +oh just let me say it this way + + align:start position:0% + + + + align:start position:0% + +and if it wasn't for these restrictions + + align:start position:0% +and if it wasn't for these restrictions + + + align:start position:0% +and if it wasn't for these restrictions +here + + align:start position:0% +here + + + align:start position:0% +here +then that's very easy actually + + align:start position:0% +then that's very easy actually + + + align:start position:0% +then that's very easy actually +so i claim and then i'll talk about why + + align:start position:0% +so i claim and then i'll talk about why + + + align:start position:0% +so i claim and then i'll talk about why +it's true + + align:start position:0% +it's true + + + align:start position:0% +it's true +i claim that if we ignored the + + align:start position:0% +i claim that if we ignored the + + + align:start position:0% +i claim that if we ignored the +restrictions + + align:start position:0% + + + + align:start position:0% + +and those restrictions are ensuring that + + align:start position:0% +and those restrictions are ensuring that + + + align:start position:0% +and those restrictions are ensuring that +we don't double count + + align:start position:0% +we don't double count + + + align:start position:0% +we don't double count +between our linear and our ultrasoft + + align:start position:0% +between our linear and our ultrasoft + + + align:start position:0% +between our linear and our ultrasoft +degrees of freedom so they are important + + align:start position:0% +degrees of freedom so they are important + + + align:start position:0% +degrees of freedom so they are important +but let's ignore them for a minute if we + + align:start position:0% +but let's ignore them for a minute if we + + + align:start position:0% +but let's ignore them for a minute if we +do ignore them + + align:start position:0% + + + + align:start position:0% + +we would just get the following + + align:start position:0% + + + + align:start position:0% + +where i just basically stop thinking + + align:start position:0% +where i just basically stop thinking + + + align:start position:0% +where i just basically stop thinking +about residuals and labels write + + align:start position:0% +about residuals and labels write + + + align:start position:0% +about residuals and labels write +everything + + align:start position:0% +everything + + + align:start position:0% +everything +as a full momentum and write down + + align:start position:0% +as a full momentum and write down + + + align:start position:0% +as a full momentum and write down +exactly the same thing i just wrote + + align:start position:0% +exactly the same thing i just wrote + + + align:start position:0% +exactly the same thing i just wrote +so this is a full k squared + + align:start position:0% +so this is a full k squared + + + align:start position:0% +so this is a full k squared +and this is the full k plus p squared + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +so what i'm going to do is i'm going to + + align:start position:0% +so what i'm going to do is i'm going to + + + align:start position:0% +so what i'm going to do is i'm going to +first + + align:start position:0% +first + + + align:start position:0% +first +ignore these relabel these restrictions + + align:start position:0% +ignore these relabel these restrictions + + + align:start position:0% +ignore these relabel these restrictions +and then i'm going to tell you how it + + align:start position:0% +and then i'm going to tell you how it + + + align:start position:0% +and then i'm going to tell you how it +would work how like this actually does + + align:start position:0% +would work how like this actually does + + + align:start position:0% +would work how like this actually does +turn into this + + align:start position:0% +turn into this + + + align:start position:0% +turn into this +what are the rules for doing that + + align:start position:0% +what are the rules for doing that + + + align:start position:0% +what are the rules for doing that +and then i'll come back and i'll tell + + align:start position:0% +and then i'll come back and i'll tell + + + align:start position:0% +and then i'll come back and i'll tell +you what what these extra + + align:start position:0% +you what what these extra + + + align:start position:0% +you what what these extra +conditions do + + align:start position:0% + + + + align:start position:0% + +so really in order to see + + align:start position:0% +so really in order to see + + + align:start position:0% +so really in order to see +so this is this looks like maybe it's + + align:start position:0% +so this is this looks like maybe it's + + + align:start position:0% +so this is this looks like maybe it's +trivial but + + align:start position:0% +trivial but + + + align:start position:0% +trivial but +we should think about it and + + align:start position:0% +we should think about it and + + + align:start position:0% +we should think about it and +uh it's almost trivial but not quite so + + align:start position:0% +uh it's almost trivial but not quite so + + + align:start position:0% +uh it's almost trivial but not quite so +really what we're doing here is we're + + align:start position:0% +really what we're doing here is we're + + + align:start position:0% +really what we're doing here is we're +combining back together labels in + + align:start position:0% +combining back together labels in + + + align:start position:0% +combining back together labels in +residual momentum right + + align:start position:0% +residual momentum right + + + align:start position:0% +residual momentum right +and the place that we have to worry + + align:start position:0% +and the place that we have to worry + + + align:start position:0% +and the place that we have to worry +about that is in the perp and the minus + + align:start position:0% +about that is in the perp and the minus + + + align:start position:0% +about that is in the perp and the minus +space and recall we have the + + align:start position:0% + + + + align:start position:0% + +grid and the grid is sort of our way of + + align:start position:0% +grid and the grid is sort of our way of + + + align:start position:0% +grid and the grid is sort of our way of +got our guiding + + align:start position:0% +got our guiding + + + align:start position:0% +got our guiding +our guidance to sort of see how to put + + align:start position:0% +our guidance to sort of see how to put + + + align:start position:0% +our guidance to sort of see how to put +things back together + + align:start position:0% + + + + align:start position:0% + +so we had vectors that lived in this + + align:start position:0% +so we had vectors that lived in this + + + align:start position:0% +so we had vectors that lived in this +space and + + align:start position:0% +space and + + + align:start position:0% +space and +you know this is the label and then + + align:start position:0% +you know this is the label and then + + + align:start position:0% +you know this is the label and then +there's the residual if we want to point + + align:start position:0% +there's the residual if we want to point + + + align:start position:0% +there's the residual if we want to point +to some place in that space + + align:start position:0% + + + + align:start position:0% + +this picture was like a wilsonian + + align:start position:0% +this picture was like a wilsonian + + + align:start position:0% +this picture was like a wilsonian +effective field theory + + align:start position:0% +effective field theory + + + align:start position:0% +effective field theory +because the picture makes you think of + + align:start position:0% +because the picture makes you think of + + + align:start position:0% +because the picture makes you think of +sharp edges + + align:start position:0% + + + + align:start position:0% + +but the real effective theory that we're + + align:start position:0% +but the real effective theory that we're + + + align:start position:0% +but the real effective theory that we're +doing is a continuum one + + align:start position:0% + + + + align:start position:0% + +and so you have to expand your brain a + + align:start position:0% +and so you have to expand your brain a + + + align:start position:0% +and so you have to expand your brain a +little bit and think that each of the + + align:start position:0% +little bit and think that each of the + + + align:start position:0% +little bit and think that each of the +boxes in this picture is actually + + align:start position:0% +boxes in this picture is actually + + + align:start position:0% +boxes in this picture is actually +an infinite space as well + + align:start position:0% +an infinite space as well + + + align:start position:0% +an infinite space as well +because the residual space doesn't have + + align:start position:0% +because the residual space doesn't have + + + align:start position:0% +because the residual space doesn't have +restrictions like that that would spoil + + align:start position:0% +restrictions like that that would spoil + + + align:start position:0% +restrictions like that that would spoil +lorenz symmetry + + align:start position:0% + + + + align:start position:0% + +so each grid point + + align:start position:0% + + + + align:start position:0% + +really is specifying an infinite + + align:start position:0% +really is specifying an infinite + + + align:start position:0% +really is specifying an infinite +space + + align:start position:0% + + + + align:start position:0% + +of residual manta + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +it's r4 i mean or it's minkowski space + + align:start position:0% +it's r4 i mean or it's minkowski space + + + align:start position:0% +it's r4 i mean or it's minkowski space +so the momenta components are real + + align:start position:0% +so the momenta components are real + + + align:start position:0% +so the momenta components are real +numbers + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +there's some rules so what are the rules + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% + + + + align:start position:0% + +i'll tell you what the rules are without + + align:start position:0% +i'll tell you what the rules are without + + + align:start position:0% +i'll tell you what the rules are without +restrictions for now + + align:start position:0% +restrictions for now + + + align:start position:0% +restrictions for now +and then we'll come back and i'll tell + + align:start position:0% +and then we'll come back and i'll tell + + + align:start position:0% +and then we'll come back and i'll tell +you what the rules are with restrictions + + align:start position:0% + + + + align:start position:0% + +so rule number one is the simplest and + + align:start position:0% +so rule number one is the simplest and + + + align:start position:0% +so rule number one is the simplest and +it just says that say i had a + + align:start position:0% +it just says that say i had a + + + align:start position:0% +it just says that say i had a +the following + + align:start position:0% +the following + + + align:start position:0% +the following +i'll use kind of a one-dimensional + + align:start position:0% +i'll use kind of a one-dimensional + + + align:start position:0% +i'll use kind of a one-dimensional +notation + + align:start position:0% +notation + + + align:start position:0% +notation +say i had a sum over kl's and an + + align:start position:0% +say i had a sum over kl's and an + + + align:start position:0% +say i had a sum over kl's and an +integral over all kr's + + align:start position:0% +integral over all kr's + + + align:start position:0% +integral over all kr's +well that's just the same as not having + + align:start position:0% +well that's just the same as not having + + + align:start position:0% +well that's just the same as not having +split it up and doing an integral over + + align:start position:0% +split it up and doing an integral over + + + align:start position:0% +split it up and doing an integral over +everything + + align:start position:0% +everything + + + align:start position:0% +everything +because we split this thing into boxes + + align:start position:0% +because we split this thing into boxes + + + align:start position:0% +because we split this thing into boxes +and if we really integrate over all + + align:start position:0% +and if we really integrate over all + + + align:start position:0% +and if we really integrate over all +boxes and + + align:start position:0% +boxes and + + + align:start position:0% +boxes and +and uh + + align:start position:0% +and uh + + + align:start position:0% +and uh +sum over all labels then we should just + + align:start position:0% +sum over all labels then we should just + + + align:start position:0% +sum over all labels then we should just +get back the full integration over all + + align:start position:0% +get back the full integration over all + + + align:start position:0% +get back the full integration over all +the momentum + + align:start position:0% + + + + align:start position:0% + +so that's true for each + + align:start position:0% +so that's true for each + + + align:start position:0% +so that's true for each +for minus and momenta + + align:start position:0% + + + + align:start position:0% + +but really what we have to do + + align:start position:0% +but really what we have to do + + + align:start position:0% +but really what we have to do +is we have to do this with some + + align:start position:0% +is we have to do this with some + + + align:start position:0% +is we have to do this with some +integrand right so + + align:start position:0% +integrand right so + + + align:start position:0% +integrand right so +the type of integrand that we have is + + align:start position:0% +the type of integrand that we have is + + + align:start position:0% +the type of integrand that we have is +this following + + align:start position:0% +this following + + + align:start position:0% +this following +if you think about the components + + align:start position:0% + + + + align:start position:0% + +if you think about the components that + + align:start position:0% +if you think about the components that + + + align:start position:0% +if you think about the components that +we're talking about here + + align:start position:0% +we're talking about here + + + align:start position:0% +we're talking about here +which are the minus and perp ones + + align:start position:0% +which are the minus and perp ones + + + align:start position:0% +which are the minus and perp ones +then there's in our integrand up there + + align:start position:0% +then there's in our integrand up there + + + align:start position:0% +then there's in our integrand up there +there's no minus or perp + + align:start position:0% +there's no minus or perp + + + align:start position:0% +there's no minus or perp +residuals + + align:start position:0% +residuals + + + align:start position:0% +residuals +so + + align:start position:0% +so + + + align:start position:0% +so +it's just a function of the labels + + align:start position:0% + + + + align:start position:0% + +right + + align:start position:0% +right + + + align:start position:0% +right +and so what that says effectively is + + align:start position:0% +and so what that says effectively is + + + align:start position:0% +and so what that says effectively is +that + + align:start position:0% +that + + + align:start position:0% +that +this is a constant function in in this + + align:start position:0% +this is a constant function in in this + + + align:start position:0% +this is a constant function in in this +box + + align:start position:0% +box + + + align:start position:0% +box +in each of the boxes + + align:start position:0% + + + + align:start position:0% + +and effectively the way that you use + + align:start position:0% +and effectively the way that you use + + + align:start position:0% +and effectively the way that you use +this formula as you do the following + + align:start position:0% +this formula as you do the following + + + align:start position:0% +this formula as you do the following +you say well if it's a constant function + + align:start position:0% +you say well if it's a constant function + + + align:start position:0% +you say well if it's a constant function +in the box + + align:start position:0% +in the box + + + align:start position:0% +in the box +i could evaluate at a different point in + + align:start position:0% +i could evaluate at a different point in + + + align:start position:0% +i could evaluate at a different point in +the box and i'd still get the same value + + align:start position:0% +the box and i'd still get the same value + + + align:start position:0% +the box and i'd still get the same value +so in particular i could evaluate it k + + align:start position:0% +so in particular i could evaluate it k + + + align:start position:0% +so in particular i could evaluate it k +label plus k residual + + align:start position:0% +label plus k residual + + + align:start position:0% +label plus k residual +and then i can use that formula up there + + align:start position:0% +and then i can use that formula up there + + + align:start position:0% +and then i can use that formula up there +to say that this is just an integral + + align:start position:0% +to say that this is just an integral + + + align:start position:0% +to say that this is just an integral +with a continuous k + + align:start position:0% +with a continuous k + + + align:start position:0% +with a continuous k +of the function evaluated at that + + align:start position:0% +of the function evaluated at that + + + align:start position:0% +of the function evaluated at that +continuous k + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% + + + + align:start position:0% + +so that's the way that sort of number + + align:start position:0% +so that's the way that sort of number + + + align:start position:0% +so that's the way that sort of number +one works + + align:start position:0% +one works + + + align:start position:0% +one works +we are integrating functions that are + + align:start position:0% +we are integrating functions that are + + + align:start position:0% +we are integrating functions that are +constant in the boxes and so then it's + + align:start position:0% +constant in the boxes and so then it's + + + align:start position:0% +constant in the boxes and so then it's +kind of trivial that we just how to put + + align:start position:0% +kind of trivial that we just how to put + + + align:start position:0% +kind of trivial that we just how to put +the boxes back together + + align:start position:0% +the boxes back together + + + align:start position:0% +the boxes back together +yeah so this uh + + align:start position:0% +yeah so this uh + + + align:start position:0% +yeah so this uh +dk identification doesn't have k out of + + align:start position:0% +dk identification doesn't have k out of + + + align:start position:0% +dk identification doesn't have k out of +place + + align:start position:0% +place + + + align:start position:0% +place +yeah so what i mean by it is + + align:start position:0% +yeah so what i mean by it is + + + align:start position:0% +yeah so what i mean by it is +yeah so each of so i'm using here + + align:start position:0% +yeah so each of so i'm using here + + + align:start position:0% +yeah so each of so i'm using here +for each minus or perp momenta a + + align:start position:0% +for each minus or perp momenta a + + + align:start position:0% +for each minus or perp momenta a +one-dimensional notation yeah and so i + + align:start position:0% +one-dimensional notation yeah and so i + + + align:start position:0% +one-dimensional notation yeah and so i +have three of these i have to do this + + align:start position:0% +have three of these i have to do this + + + align:start position:0% +have three of these i have to do this +and for each one of them it's true that + + align:start position:0% +and for each one of them it's true that + + + align:start position:0% +and for each one of them it's true that +what i'm saying + + align:start position:0% +what i'm saying + + + align:start position:0% +what i'm saying +but of course if i tried to write that + + align:start position:0% +but of course if i tried to write that + + + align:start position:0% +but of course if i tried to write that +on the board then it would confuse the + + align:start position:0% +on the board then it would confuse the + + + align:start position:0% +on the board then it would confuse the +point i think + + align:start position:0% +point i think + + + align:start position:0% +point i think +which is some sense a simple point + + align:start position:0% +which is some sense a simple point + + + align:start position:0% +which is some sense a simple point +okay so this is in some sense saying + + align:start position:0% +okay so this is in some sense saying + + + align:start position:0% +okay so this is in some sense saying +that this whole split up that we were + + align:start position:0% +that this whole split up that we were + + + align:start position:0% +that this whole split up that we were +doing was not really needed we could + + align:start position:0% +doing was not really needed we could + + + align:start position:0% +doing was not really needed we could +have just written a continuous integral + + align:start position:0% +have just written a continuous integral + + + align:start position:0% +have just written a continuous integral +and that's kind of what this is saying + + align:start position:0% +and that's kind of what this is saying + + + align:start position:0% +and that's kind of what this is saying +right that + + align:start position:0% +right that + + + align:start position:0% +right that +we could have just written a continuous + + align:start position:0% +we could have just written a continuous + + + align:start position:0% +we could have just written a continuous +integral and not worried so much about + + align:start position:0% +integral and not worried so much about + + + align:start position:0% +integral and not worried so much about +all the split up that we were doing + + align:start position:0% +all the split up that we were doing + + + align:start position:0% +all the split up that we were doing +the place that that we have to be + + align:start position:0% +the place that that we have to be + + + align:start position:0% +the place that that we have to be +careful about is these restrictions and + + align:start position:0% +careful about is these restrictions and + + + align:start position:0% +careful about is these restrictions and +we'll come back to that + + align:start position:0% +we'll come back to that + + + align:start position:0% +we'll come back to that +and the other place they have to be + + align:start position:0% +and the other place they have to be + + + align:start position:0% +and the other place they have to be +careful about is when you have the + + align:start position:0% +careful about is when you have the + + + align:start position:0% +careful about is when you have the +multiple expansion but as long as you + + align:start position:0% +multiple expansion but as long as you + + + align:start position:0% +multiple expansion but as long as you +sort of take care of that then basically + + align:start position:0% +sort of take care of that then basically + + + align:start position:0% +sort of take care of that then basically +this is always + + align:start position:0% +this is always + + + align:start position:0% +this is always +is always happening + + align:start position:0% +is always happening + + + align:start position:0% +is always happening +so + + align:start position:0% +so + + + align:start position:0% +so +the reason why this works + + align:start position:0% +the reason why this works + + + align:start position:0% +the reason why this works +is the following + + align:start position:0% + + + + align:start position:0% + +for every label loop momentum that there + + align:start position:0% +for every label loop momentum that there + + + align:start position:0% +for every label loop momentum that there +is in any diagram + + align:start position:0% +is in any diagram + + + align:start position:0% +is in any diagram +there's always going to be some + + align:start position:0% +there's always going to be some + + + align:start position:0% +there's always going to be some +corresponding + + align:start position:0% + + + + align:start position:0% + +residual + + align:start position:0% + + + + align:start position:0% + +that's not specified by delta functions + + align:start position:0% +that's not specified by delta functions + + + align:start position:0% +that's not specified by delta functions +in terms of external momenta + + align:start position:0% +in terms of external momenta + + + align:start position:0% +in terms of external momenta +and effectively therefore we can that we + + align:start position:0% +and effectively therefore we can that we + + + align:start position:0% +and effectively therefore we can that we +can absorb + + align:start position:0% +can absorb + + + align:start position:0% +can absorb +in order to do what we just said + + align:start position:0% + + + + align:start position:0% + +so we can always go back from + + align:start position:0% +so we can always go back from + + + align:start position:0% +so we can always go back from +this discrete type notation back to a + + align:start position:0% +this discrete type notation back to a + + + align:start position:0% +this discrete type notation back to a +continuous notation the discrete + + align:start position:0% +continuous notation the discrete + + + align:start position:0% +continuous notation the discrete +notation was just helping us to set up + + align:start position:0% +notation was just helping us to set up + + + align:start position:0% +notation was just helping us to set up +the expansion and be careful about it + + align:start position:0% +the expansion and be careful about it + + + align:start position:0% +the expansion and be careful about it +but we can always go back to the + + align:start position:0% +but we can always go back to the + + + align:start position:0% +but we can always go back to the +continuous one because there's always a + + align:start position:0% +continuous one because there's always a + + + align:start position:0% +continuous one because there's always a +kr + + align:start position:0% +kr + + + align:start position:0% +kr +that has this property that it's + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% + + + + align:start position:0% + +now in general though you might have + + align:start position:0% +now in general though you might have + + + align:start position:0% +now in general though you might have +some more complicated thing and if i'm + + align:start position:0% +some more complicated thing and if i'm + + + align:start position:0% +some more complicated thing and if i'm +going to give you some rules i should + + align:start position:0% +going to give you some rules i should + + + align:start position:0% +going to give you some rules i should +sort of give you a complete set + + align:start position:0% +sort of give you a complete set + + + align:start position:0% +sort of give you a complete set +so + + align:start position:0% +so + + + align:start position:0% +so +we have to append our + + align:start position:0% + + + + align:start position:0% + +our list of rules by the following one + + align:start position:0% + + + + align:start position:0% + +so if i thought about doing what i just + + align:start position:0% +so if i thought about doing what i just + + + align:start position:0% +so if i thought about doing what i just +said over here but i went to some higher + + align:start position:0% +said over here but i went to some higher + + + align:start position:0% +said over here but i went to some higher +order then what could happen + + align:start position:0% +order then what could happen + + + align:start position:0% +order then what could happen +well then these kr minus and kr perps + + align:start position:0% +well then these kr minus and kr perps + + + align:start position:0% +well then these kr minus and kr perps +could show up + + align:start position:0% +could show up + + + align:start position:0% +could show up +they'd never show up in the denominator + + align:start position:0% +they'd never show up in the denominator + + + align:start position:0% +they'd never show up in the denominator +of our propagators if they were just + + align:start position:0% +of our propagators if they were just + + + align:start position:0% +of our propagators if they were just +linear propagators but they could show + + align:start position:0% +linear propagators but they could show + + + align:start position:0% +linear propagators but they could show +up at some point in the numerator + + align:start position:0% +up at some point in the numerator + + + align:start position:0% +up at some point in the numerator +and we need actually a rule like this + + align:start position:0% +and we need actually a rule like this + + + align:start position:0% +and we need actually a rule like this +one which is + + align:start position:0% +one which is + + + align:start position:0% +one which is +would be clear if we were regulating dkr + + align:start position:0% +would be clear if we were regulating dkr + + + align:start position:0% +would be clear if we were regulating dkr +in in dimensional organization that the + + align:start position:0% +in in dimensional organization that the + + + align:start position:0% +in in dimensional organization that the +power divergences are getting set to + + align:start position:0% +power divergences are getting set to + + + align:start position:0% +power divergences are getting set to +zero + + align:start position:0% +zero + + + align:start position:0% +zero +and that is is basically to maintain the + + align:start position:0% +and that is is basically to maintain the + + + align:start position:0% +and that is is basically to maintain the +the rent symmetry in the residual space + + align:start position:0% +the rent symmetry in the residual space + + + align:start position:0% +the rent symmetry in the residual space +we need a rule like this + + align:start position:0% + + + + align:start position:0% + +for j greater than zero + + align:start position:0% + + + + align:start position:0% + +so that only comes in doesn't come into + + align:start position:0% +so that only comes in doesn't come into + + + align:start position:0% +so that only comes in doesn't come into +our calculation but + + align:start position:0% +our calculation but + + + align:start position:0% +our calculation but +include it for completeness + + align:start position:0% +include it for completeness + + + align:start position:0% +include it for completeness +so when would these integral over kr + + align:start position:0% +so when would these integral over kr + + + align:start position:0% +so when would these integral over kr +actually do something non-trivial it + + align:start position:0% +actually do something non-trivial it + + + align:start position:0% +actually do something non-trivial it +would do something non-trivial if we had + + align:start position:0% +would do something non-trivial if we had + + + align:start position:0% +would do something non-trivial if we had +ultra soft loops and collinear loops at + + align:start position:0% +ultra soft loops and collinear loops at + + + align:start position:0% +ultra soft loops and collinear loops at +the same time + + align:start position:0% + + + + align:start position:0% + +so in the case where we just have + + align:start position:0% +so in the case where we just have + + + align:start position:0% +so in the case where we just have +collinear loops it's basically up to + + align:start position:0% +collinear loops it's basically up to + + + align:start position:0% +collinear loops it's basically up to +this issue about the restrictions that + + align:start position:0% +this issue about the restrictions that + + + align:start position:0% +this issue about the restrictions that +we'll talk about it's basically that we + + align:start position:0% +we'll talk about it's basically that we + + + align:start position:0% +we'll talk about it's basically that we +just could have done everything as + + align:start position:0% +just could have done everything as + + + align:start position:0% +just could have done everything as +continuous and ignored this + + align:start position:0% +continuous and ignored this + + + align:start position:0% +continuous and ignored this +this split + + align:start position:0% + + + + align:start position:0% + +but if we have both ultrasoft particles + + align:start position:0% +but if we have both ultrasoft particles + + + align:start position:0% +but if we have both ultrasoft particles +that are sort of participating through + + align:start position:0% +that are sort of participating through + + + align:start position:0% +that are sort of participating through +the loops + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +or and and or + + align:start position:0% + + + + align:start position:0% + +then these will give non-trivial + + align:start position:0% + + + + align:start position:0% + +in general these will give non-trivial + + align:start position:0% +in general these will give non-trivial + + + align:start position:0% +in general these will give non-trivial +loop momenta + + align:start position:0% +loop momenta + + + align:start position:0% +loop momenta +in the residual momentum + + align:start position:0% +in the residual momentum + + + align:start position:0% +in the residual momentum +and + + align:start position:0% +and + + + align:start position:0% +and +hence there will be some that we can't + + align:start position:0% +hence there will be some that we can't + + + align:start position:0% +hence there will be some that we can't +just absorb in the fashion that we just + + align:start position:0% +just absorb in the fashion that we just + + + align:start position:0% +just absorb in the fashion that we just +said so there will be + + align:start position:0% +said so there will be + + + align:start position:0% +said so there will be +in this situation + + align:start position:0% +in this situation + + + align:start position:0% +in this situation +residual momentum some residual momentum + + align:start position:0% +residual momentum some residual momentum + + + align:start position:0% +residual momentum some residual momentum +will be absorbed in the same way to turn + + align:start position:0% +will be absorbed in the same way to turn + + + align:start position:0% +will be absorbed in the same way to turn +the integrals into continuous ones but + + align:start position:0% +the integrals into continuous ones but + + + align:start position:0% +the integrals into continuous ones but +other ones won't be absorbed + + align:start position:0% + + + + align:start position:0% + +and that's because the ultrasoft + + align:start position:0% +and that's because the ultrasoft + + + align:start position:0% +and that's because the ultrasoft +propagators rate would involve l r + + align:start position:0% +propagators rate would involve l r + + + align:start position:0% +propagators rate would involve l r +the lr plus the lr minus and the lr perp + + align:start position:0% +the lr plus the lr minus and the lr perp + + + align:start position:0% +the lr plus the lr minus and the lr perp +in the denominator + + align:start position:0% +in the denominator + + + align:start position:0% +in the denominator +so we don't have this rule to apply we + + align:start position:0% +so we don't have this rule to apply we + + + align:start position:0% +so we don't have this rule to apply we +can't do what we said here with the + + align:start position:0% +can't do what we said here with the + + + align:start position:0% +can't do what we said here with the +constant boxes because now the functions + + align:start position:0% +constant boxes because now the functions + + + align:start position:0% +constant boxes because now the functions +are depending on that variable + + align:start position:0% +are depending on that variable + + + align:start position:0% +are depending on that variable +so we just have to do the integral + + align:start position:0% +so we just have to do the integral + + + align:start position:0% +so we just have to do the integral +so you could have something that looks + + align:start position:0% +so you could have something that looks + + + align:start position:0% +so you could have something that looks +like + + align:start position:0% + + + + align:start position:0% + +just in kind of a schematic formula + + align:start position:0% +just in kind of a schematic formula + + + align:start position:0% +just in kind of a schematic formula +let's have there be two kr and an lr + + align:start position:0% +let's have there be two kr and an lr + + + align:start position:0% +let's have there be two kr and an lr +we're in kind of an obvious notation + + align:start position:0% +we're in kind of an obvious notation + + + align:start position:0% +we're in kind of an obvious notation +i'm saying that the function could + + align:start position:0% +i'm saying that the function could + + + align:start position:0% +i'm saying that the function could +depend on lr residual it doesn't depend + + align:start position:0% +depend on lr residual it doesn't depend + + + align:start position:0% +depend on lr residual it doesn't depend +on kr residuals so we absorb kr back + + align:start position:0% +on kr residuals so we absorb kr back + + + align:start position:0% +on kr residuals so we absorb kr back +into the sum to make it continuous and + + align:start position:0% +into the sum to make it continuous and + + + align:start position:0% +into the sum to make it continuous and +then this integral we just have to do + + align:start position:0% + + + + align:start position:0% + +okay but it's still + + align:start position:0% +okay but it's still + + + align:start position:0% +okay but it's still +we're still in the end just doing an + + align:start position:0% +we're still in the end just doing an + + + align:start position:0% +we're still in the end just doing an +interval + + align:start position:0% + + + + align:start position:0% + +so this guy + + align:start position:0% + + + + align:start position:0% + +come from ultra soft propagators for + + align:start position:0% +come from ultra soft propagators for + + + align:start position:0% +come from ultra soft propagators for +example + + align:start position:0% + + + + align:start position:0% + +okay so those are the kind of different + + align:start position:0% +okay so those are the kind of different + + + align:start position:0% +okay so those are the kind of different +cases that you can get but nevertheless + + align:start position:0% +cases that you can get but nevertheless + + + align:start position:0% +cases that you can get but nevertheless +even if you have ultrasoft particles and + + align:start position:0% +even if you have ultrasoft particles and + + + align:start position:0% +even if you have ultrasoft particles and +propagators floating around there will + + align:start position:0% +propagators floating around there will + + + align:start position:0% +propagators floating around there will +always be a residual momentum associated + + align:start position:0% +always be a residual momentum associated + + + align:start position:0% +always be a residual momentum associated +to the sort of what we were doing over + + align:start position:0% +to the sort of what we were doing over + + + align:start position:0% +to the sort of what we were doing over +here + + align:start position:0% +here + + + align:start position:0% +here +that you can absorb in the same way i + + align:start position:0% +that you can absorb in the same way i + + + align:start position:0% +that you can absorb in the same way i +i stated + + align:start position:0% + + + + align:start position:0% + +so let's proceed along these lines and + + align:start position:0% +so let's proceed along these lines and + + + align:start position:0% +so let's proceed along these lines and +see where it takes us and then we'll + + align:start position:0% +see where it takes us and then we'll + + + align:start position:0% +see where it takes us and then we'll +come back and put in this + + align:start position:0% +come back and put in this + + + align:start position:0% +come back and put in this +additional restrictions + + align:start position:0% +additional restrictions + + + align:start position:0% +additional restrictions +will you ever have to do a discrete + + align:start position:0% +will you ever have to do a discrete + + + align:start position:0% +will you ever have to do a discrete +sound like is there a cell + + align:start position:0% + + + + align:start position:0% + +yeah so you never have to do a discrete + + align:start position:0% +yeah so you never have to do a discrete + + + align:start position:0% +yeah so you never have to do a discrete +sum + + align:start position:0% +sum + + + align:start position:0% +sum +yep + + align:start position:0% +yep + + + align:start position:0% +yep +the discrete sum is really just a way of + + align:start position:0% +the discrete sum is really just a way of + + + align:start position:0% +the discrete sum is really just a way of +thinking and and i + + align:start position:0% +thinking and and i + + + align:start position:0% +thinking and and i +i'll show you in a minute that you even + + align:start position:0% +i'll show you in a minute that you even + + + align:start position:0% +i'll show you in a minute that you even +can avoid thinking about it once you + + align:start position:0% +can avoid thinking about it once you + + + align:start position:0% +can avoid thinking about it once you +know what to do + + align:start position:0% +know what to do + + + align:start position:0% +know what to do +so it's guiding you towards the right + + align:start position:0% +so it's guiding you towards the right + + + align:start position:0% +so it's guiding you towards the right +answer but it's not really something + + align:start position:0% +answer but it's not really something + + + align:start position:0% +answer but it's not really something +that you have to think about this grid + + align:start position:0% +that you have to think about this grid + + + align:start position:0% +that you have to think about this grid +picture it's really just if you get + + align:start position:0% +picture it's really just if you get + + + align:start position:0% +picture it's really just if you get +confused you can always think about it + + align:start position:0% +confused you can always think about it + + + align:start position:0% +confused you can always think about it +but if you're not confused you don't + + align:start position:0% +but if you're not confused you don't + + + align:start position:0% +but if you're not confused you don't +have to think about it + + align:start position:0% + + + + align:start position:0% + +okay so this guy + + align:start position:0% +okay so this guy + + + align:start position:0% +okay so this guy +is what we said + + align:start position:0% +is what we said + + + align:start position:0% +is what we said +proportional to what we said + + align:start position:0% +proportional to what we said + + + align:start position:0% +proportional to what we said +it's just + + align:start position:0% + + + + align:start position:0% + +in this case the reason why it was so + + align:start position:0% +in this case the reason why it was so + + + align:start position:0% +in this case the reason why it was so +simple is because there was only k + + align:start position:0% +simple is because there was only k + + + align:start position:0% +simple is because there was only k +k residual is one component of this guy + + align:start position:0% +k residual is one component of this guy + + + align:start position:0% +k residual is one component of this guy +and then there's these other three right + + align:start position:0% +and then there's these other three right + + + align:start position:0% +and then there's these other three right +and for the other three we just absorb + + align:start position:0% +and for the other three we just absorb + + + align:start position:0% +and for the other three we just absorb +we absorb the sum and the integral back + + align:start position:0% +we absorb the sum and the integral back + + + align:start position:0% +we absorb the sum and the integral back +together and there's + + align:start position:0% +together and there's + + + align:start position:0% +together and there's +nothing further to talk about so that's + + align:start position:0% +nothing further to talk about so that's + + + align:start position:0% +nothing further to talk about so that's +why this isn't + + align:start position:0% + + + + align:start position:0% + +some sense very simple + + align:start position:0% +some sense very simple + + + align:start position:0% +some sense very simple +so we just do that + + align:start position:0% + + + + align:start position:0% + +and what do we get + + align:start position:0% + + + + align:start position:0% + +get some one over epsilons + + align:start position:0% + + + + align:start position:0% + +we get some logs of p squared + + align:start position:0% + + + + align:start position:0% + +and i'm putting an even + + align:start position:0% +and i'm putting an even + + + align:start position:0% +and i'm putting an even +the constant term since it's pretty + + align:start position:0% +the constant term since it's pretty + + + align:start position:0% +the constant term since it's pretty +simple 4 minus pi squared over 6. + + align:start position:0% +simple 4 minus pi squared over 6. + + + align:start position:0% +simple 4 minus pi squared over 6. +so this is + + align:start position:0% +so this is + + + align:start position:0% +so this is +we had a loop we had a if you remember + + align:start position:0% +we had a loop we had a if you remember + + + align:start position:0% +we had a loop we had a if you remember +think about where this came from there + + align:start position:0% +think about where this came from there + + + align:start position:0% +think about where this came from there +was a the place that this wilson line + + align:start position:0% +was a the place that this wilson line + + + align:start position:0% +was a the place that this wilson line +came from was attaching this guy over + + align:start position:0% +came from was attaching this guy over + + + align:start position:0% +came from was attaching this guy over +here and then integrating out that prop + + align:start position:0% +here and then integrating out that prop + + + align:start position:0% +here and then integrating out that prop +that offshore propagator so this is a + + align:start position:0% +that offshore propagator so this is a + + + align:start position:0% +that offshore propagator so this is a +vertex diagram we had a vertex diagram + + align:start position:0% +vertex diagram we had a vertex diagram + + + align:start position:0% +vertex diagram we had a vertex diagram +which is an ultrasoft gluon and now + + align:start position:0% +which is an ultrasoft gluon and now + + + align:start position:0% +which is an ultrasoft gluon and now +we've added an identical type topology + + align:start position:0% +we've added an identical type topology + + + align:start position:0% +we've added an identical type topology +except we drew it different because + + align:start position:0% +except we drew it different because + + + align:start position:0% +except we drew it different because +this line was off shell + + align:start position:0% +this line was off shell + + + align:start position:0% +this line was off shell +so we drew it as a wilson line and + + align:start position:0% +so we drew it as a wilson line and + + + align:start position:0% +so we drew it as a wilson line and +that's the right way of thinking about + + align:start position:0% +that's the right way of thinking about + + + align:start position:0% +that's the right way of thinking about +it but if you think about where it came + + align:start position:0% +it but if you think about where it came + + + align:start position:0% +it but if you think about where it came +from it was the same topology and we've + + align:start position:0% +from it was the same topology and we've + + + align:start position:0% +from it was the same topology and we've +added another vertex diagram so the + + align:start position:0% +added another vertex diagram so the + + + align:start position:0% +added another vertex diagram so the +effective theory has two type of vertex + + align:start position:0% +effective theory has two type of vertex + + + align:start position:0% +effective theory has two type of vertex +diagrams this collinear one and the + + align:start position:0% +diagrams this collinear one and the + + + align:start position:0% +diagrams this collinear one and the +ultrasoft one and we're going to add + + align:start position:0% +ultrasoft one and we're going to add + + + align:start position:0% +ultrasoft one and we're going to add +them together + + align:start position:0% +them together + + + align:start position:0% +them together +and in this one you see the logs are + + align:start position:0% +and in this one you see the logs are + + + align:start position:0% +and in this one you see the logs are +minimized at a different scale mu + + align:start position:0% +minimized at a different scale mu + + + align:start position:0% +minimized at a different scale mu +squared of order p squared which is the + + align:start position:0% +squared of order p squared which is the + + + align:start position:0% +squared of order p squared which is the +right scale for a collinear loop + + align:start position:0% + + + + align:start position:0% + +because remember the linear particles + + align:start position:0% +because remember the linear particles + + + align:start position:0% +because remember the linear particles +lived at a larger p squared than the + + align:start position:0% + + + + align:start position:0% + +the ultrasoft ones + + align:start position:0% +the ultrasoft ones + + + align:start position:0% +the ultrasoft ones +so this is a larger there's a larger + + align:start position:0% +so this is a larger there's a larger + + + align:start position:0% +so this is a larger there's a larger +scale that would minimize these loops + + align:start position:0% +scale that would minimize these loops + + + align:start position:0% +scale that would minimize these loops +it's the linear scale + + align:start position:0% + + + + align:start position:0% + +so the effective theory is capturing the + + align:start position:0% +so the effective theory is capturing the + + + align:start position:0% +so the effective theory is capturing the +physics at that scale + + align:start position:0% + + + + align:start position:0% + +let's squeeze in another diagram here + + align:start position:0% + + + + align:start position:0% + +if we do the linear wave function + + align:start position:0% +if we do the linear wave function + + + align:start position:0% +if we do the linear wave function +normalization + + align:start position:0% +normalization + + + align:start position:0% +normalization +then this is non-zero this was zero for + + align:start position:0% +then this is non-zero this was zero for + + + align:start position:0% +then this is non-zero this was zero for +the ultrasoft gluon and but for the + + align:start position:0% +the ultrasoft gluon and but for the + + + align:start position:0% +the ultrasoft gluon and but for the +cleaner glue and it's non-zero + + align:start position:0% +cleaner glue and it's non-zero + + + align:start position:0% +cleaner glue and it's non-zero +and it's exactly actually the same as + + align:start position:0% +and it's exactly actually the same as + + + align:start position:0% +and it's exactly actually the same as +the full theory + + align:start position:0% + + + + align:start position:0% + +it's same as massless qcd + + align:start position:0% + + + + align:start position:0% + +so you can do the diagram using the + + align:start position:0% +so you can do the diagram using the + + + align:start position:0% +so you can do the diagram using the +effective theory fire neurals and that's + + align:start position:0% +effective theory fire neurals and that's + + + align:start position:0% +effective theory fire neurals and that's +what you find + + align:start position:0% +what you find + + + align:start position:0% +what you find +but you could also understand why that's + + align:start position:0% +but you could also understand why that's + + + align:start position:0% +but you could also understand why that's +true + + align:start position:0% + + + + align:start position:0% + +and the reason why it's true is nothing + + align:start position:0% +and the reason why it's true is nothing + + + align:start position:0% +and the reason why it's true is nothing +in this diagram really specifies + + align:start position:0% +in this diagram really specifies + + + align:start position:0% +in this diagram really specifies +a frame + + align:start position:0% +a frame + + + align:start position:0% +a frame +we called all the particles linear but + + align:start position:0% +we called all the particles linear but + + + align:start position:0% +we called all the particles linear but +it's not attached to anything so we + + align:start position:0% +it's not attached to anything so we + + + align:start position:0% +it's not attached to anything so we +could just take the whole diagram and + + align:start position:0% +could just take the whole diagram and + + + align:start position:0% +could just take the whole diagram and +kind of boost back to the + + align:start position:0% +kind of boost back to the + + + align:start position:0% +kind of boost back to the +frame where everything's kind of soft + + align:start position:0% +frame where everything's kind of soft + + + align:start position:0% +frame where everything's kind of soft +and then we would usually be thinking + + align:start position:0% +and then we would usually be thinking + + + align:start position:0% +and then we would usually be thinking +about it in terms of the full theory + + align:start position:0% +about it in terms of the full theory + + + align:start position:0% +about it in terms of the full theory +field so + + align:start position:0% +field so + + + align:start position:0% +field so +there's uh + + align:start position:0% +there's uh + + + align:start position:0% +there's uh +yeah and + + align:start position:0% +yeah and + + + align:start position:0% +yeah and +that's effectively why + + align:start position:0% +that's effectively why + + + align:start position:0% +that's effectively why +this diagram + + align:start position:0% +this diagram + + + align:start position:0% +this diagram +like this that doesn't have any + + align:start position:0% +like this that doesn't have any + + + align:start position:0% +like this that doesn't have any +kind of reference unlike this one which + + align:start position:0% +kind of reference unlike this one which + + + align:start position:0% +kind of reference unlike this one which +has a reference because it's attached to + + align:start position:0% +has a reference because it's attached to + + + align:start position:0% +has a reference because it's attached to +the heavy quark + + align:start position:0% +the heavy quark + + + align:start position:0% +the heavy quark +that's why it's the same as qcd + + align:start position:0% + + + + align:start position:0% + +how do you know what yeah + + align:start position:0% + + + + align:start position:0% + +yeah for this one um + + align:start position:0% +yeah for this one um + + + align:start position:0% +yeah for this one um +you for this guy + + align:start position:0% +you for this guy + + + align:start position:0% +you for this guy +it actually + + align:start position:0% +it actually + + + align:start position:0% +it actually +doesn't depend on the i epsilon + + align:start position:0% +doesn't depend on the i epsilon + + + align:start position:0% +doesn't depend on the i epsilon +prescription up to uh + + align:start position:0% +prescription up to uh + + + align:start position:0% +prescription up to uh +yeah if i remember correctly + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +that's true i believe when i'm being a + + align:start position:0% +that's true i believe when i'm being a + + + align:start position:0% +that's true i believe when i'm being a +little bit cavalier with it but once i + + align:start position:0% +little bit cavalier with it but once i + + + align:start position:0% +little bit cavalier with it but once i +put in the zero bin restrictions i'm not + + align:start position:0% +put in the zero bin restrictions i'm not + + + align:start position:0% +put in the zero bin restrictions i'm not +sure if that's true anymore + + align:start position:0% + + + + align:start position:0% + +like + + align:start position:0% +like + + + align:start position:0% +like +yeah i mean really what solves that is + + align:start position:0% +yeah i mean really what solves that is + + + align:start position:0% +yeah i mean really what solves that is +that in a minute i'm going to be talking + + align:start position:0% +that in a minute i'm going to be talking + + + align:start position:0% +that in a minute i'm going to be talking +about the fact that there's a + + align:start position:0% +about the fact that there's a + + + align:start position:0% +about the fact that there's a +subtraction term here and once you put + + align:start position:0% +subtraction term here and once you put + + + align:start position:0% +subtraction term here and once you put +the subtraction term in that i zero is + + align:start position:0% +the subtraction term in that i zero is + + + align:start position:0% +the subtraction term in that i zero is +not relevant + + align:start position:0% + + + + align:start position:0% + +but i think even if you do this diagram + + align:start position:0% +but i think even if you do this diagram + + + align:start position:0% +but i think even if you do this diagram +with arbitrary i zero + + align:start position:0% + + + + align:start position:0% + +because what's happening is that pole is + + align:start position:0% +because what's happening is that pole is + + + align:start position:0% +because what's happening is that pole is +embargo not k going to zero is related + + align:start position:0% +embargo not k going to zero is related + + + align:start position:0% +embargo not k going to zero is related +to some of these one over epsilon so + + align:start position:0% +to some of these one over epsilon so + + + align:start position:0% +to some of these one over epsilon so +we'll talk about that more in a minute + + align:start position:0% + + + + align:start position:0% + +yeah i'm not 100 sure it could be that + + align:start position:0% +yeah i'm not 100 sure it could be that + + + align:start position:0% +yeah i'm not 100 sure it could be that +there's some sign that might flip + + align:start position:0% +there's some sign that might flip + + + align:start position:0% +there's some sign that might flip +i'm not 100 sure that then + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +i i guess i know that + + align:start position:0% +i i guess i know that + + + align:start position:0% +i i guess i know that +if yeah what i know is that + + align:start position:0% +if yeah what i know is that + + + align:start position:0% +if yeah what i know is that +yeah let me let me answer your question + + align:start position:0% +yeah let me let me answer your question + + + align:start position:0% +yeah let me let me answer your question +later it'll be easier because i'm trying + + align:start position:0% +later it'll be easier because i'm trying + + + align:start position:0% +later it'll be easier because i'm trying +to say a bunch of things that depend on + + align:start position:0% +to say a bunch of things that depend on + + + align:start position:0% +to say a bunch of things that depend on +something else that i haven't explained + + align:start position:0% +something else that i haven't explained + + + align:start position:0% +something else that i haven't explained +yet so + + align:start position:0% + + + + align:start position:0% + +so what are the other possible + + align:start position:0% +so what are the other possible + + + align:start position:0% +so what are the other possible +topologies we could write down so we + + align:start position:0% +topologies we could write down so we + + + align:start position:0% +topologies we could write down so we +could write down this one where we take + + align:start position:0% +could write down this one where we take + + + align:start position:0% +could write down this one where we take +two attachments in the wilson line and + + align:start position:0% +two attachments in the wilson line and + + + align:start position:0% +two attachments in the wilson line and +just loop them back up + + align:start position:0% +just loop them back up + + + align:start position:0% +just loop them back up +but that's proportional n bar squared + + align:start position:0% +but that's proportional n bar squared + + + align:start position:0% +but that's proportional n bar squared +and so that's zero in our final gauge + + align:start position:0% + + + + align:start position:0% + +and likewise + + align:start position:0% +and likewise + + + align:start position:0% +and likewise +there's kind of a looping back up + + align:start position:0% +there's kind of a looping back up + + + align:start position:0% +there's kind of a looping back up +in the vertex in the wave function + + align:start position:0% +in the vertex in the wave function + + + align:start position:0% +in the vertex in the wave function +normalization but this guy's scaleless + + align:start position:0% + + + + align:start position:0% + +power law divergent + + align:start position:0% + + + + align:start position:0% + +and so we can just set it to zero and + + align:start position:0% +and so we can just set it to zero and + + + align:start position:0% +and so we can just set it to zero and +dim reg + + align:start position:0% + + + + align:start position:0% + +you don't have to worry about it + + align:start position:0% + + + + align:start position:0% + +okay so that's all the diagrams let's + + align:start position:0% +okay so that's all the diagrams let's + + + align:start position:0% +okay so that's all the diagrams let's +think about doing matching + + align:start position:0% +think about doing matching + + + align:start position:0% +think about doing matching +right let's think about comparing + + align:start position:0% +right let's think about comparing + + + align:start position:0% +right let's think about comparing +qcd and sct by adding up the diagrams + + align:start position:0% + + + + align:start position:0% + +in qcd we carried out the normalization + + align:start position:0% +in qcd we carried out the normalization + + + align:start position:0% +in qcd we carried out the normalization +we added the z for the tensor current + + align:start position:0% + + + + align:start position:0% + +let me just write again what the + + align:start position:0% +let me just write again what the + + + align:start position:0% +let me just write again what the +answer kind of looked like + + align:start position:0% + + + + align:start position:0% + +in sat we didn't carry out normalization + + align:start position:0% +in sat we didn't carry out normalization + + + align:start position:0% +in sat we didn't carry out normalization +yet + + align:start position:0% +yet + + + align:start position:0% +yet +so let me call this the bear fct result + + align:start position:0% +so let me call this the bear fct result + + + align:start position:0% +so let me call this the bear fct result +for now + + align:start position:0% + + + + align:start position:0% + +once we add the ultrasoft and linear + + align:start position:0% +once we add the ultrasoft and linear + + + align:start position:0% +once we add the ultrasoft and linear +diagrams together the logs of p squared + + align:start position:0% +diagrams together the logs of p squared + + + align:start position:0% +diagrams together the logs of p squared +match up exactly with the full theory + + align:start position:0% + + + + align:start position:0% + +so this is the first sign that we're + + align:start position:0% +so this is the first sign that we're + + + align:start position:0% +so this is the first sign that we're +really that it makes sense to be + + align:start position:0% +really that it makes sense to be + + + align:start position:0% +really that it makes sense to be +thinking about adding these loops even + + align:start position:0% +thinking about adding these loops even + + + align:start position:0% +thinking about adding these loops even +though they were the same topology we + + align:start position:0% +though they were the same topology we + + + align:start position:0% +though they were the same topology we +are + + align:start position:0% +are + + + align:start position:0% +are +correctly reproducing those logs of p + + align:start position:0% +correctly reproducing those logs of p + + + align:start position:0% +correctly reproducing those logs of p +squared in the full theory + + align:start position:0% + + + + align:start position:0% + +and then there's some other pieces + + align:start position:0% + + + + align:start position:0% + +i'll write out all the other pieces so + + align:start position:0% +i'll write out all the other pieces so + + + align:start position:0% +i'll write out all the other pieces so +you see what they look like + + align:start position:0% +you see what they look like + + + align:start position:0% +you see what they look like +well maybe i won't i won't write the + + align:start position:0% +well maybe i won't i won't write the + + + align:start position:0% +well maybe i won't i won't write the +constant + + align:start position:0% + + + + align:start position:0% + +so there's all the effective field + + align:start position:0% +so there's all the effective field + + + align:start position:0% +so there's all the effective field +theory terms + + align:start position:0% +theory terms + + + align:start position:0% +theory terms +so + + align:start position:0% +so + + + align:start position:0% +so +these terms here + + align:start position:0% +these terms here + + + align:start position:0% +these terms here +we can match up + + align:start position:0% +we can match up + + + align:start position:0% +we can match up +with these terms here + + align:start position:0% + + + + align:start position:0% + +so that's + + align:start position:0% +so that's + + + align:start position:0% +so that's +good these terms here + + align:start position:0% +good these terms here + + + align:start position:0% +good these terms here +which remember in the full theory were + + align:start position:0% +which remember in the full theory were + + + align:start position:0% +which remember in the full theory were +finite and these terms here which in the + + align:start position:0% +finite and these terms here which in the + + + align:start position:0% +finite and these terms here which in the +effective theory are finite the + + align:start position:0% +effective theory are finite the + + + align:start position:0% +effective theory are finite the +difference of those is going to give the + + align:start position:0% +difference of those is going to give the + + + align:start position:0% +difference of those is going to give the +wilson coefficient + + align:start position:0% + + + + align:start position:0% + +now we said that the wilson coefficient + + align:start position:0% +now we said that the wilson coefficient + + + align:start position:0% +now we said that the wilson coefficient +could be a function of p bar + + align:start position:0% +could be a function of p bar + + + align:start position:0% +could be a function of p bar +so what's going on with that + + align:start position:0% +so what's going on with that + + + align:start position:0% +so what's going on with that +well if you look at momentum + + align:start position:0% +well if you look at momentum + + + align:start position:0% +well if you look at momentum +conservation in this process of b s + + align:start position:0% +conservation in this process of b s + + + align:start position:0% +conservation in this process of b s +gamma + + align:start position:0% + + + + align:start position:0% + +so i probably should have said this + + align:start position:0% +so i probably should have said this + + + align:start position:0% +so i probably should have said this +earlier + + align:start position:0% +earlier + + + align:start position:0% +earlier +so when you look at b s gamma if you + + align:start position:0% +so when you look at b s gamma if you + + + align:start position:0% +so when you look at b s gamma if you +look at momentum conservation then + + align:start position:0% +look at momentum conservation then + + + align:start position:0% +look at momentum conservation then +the p minus of the strange quark + + align:start position:0% +the p minus of the strange quark + + + align:start position:0% +the p minus of the strange quark +has to be equal to the p minus of the b + + align:start position:0% +has to be equal to the p minus of the b + + + align:start position:0% +has to be equal to the p minus of the b +quark but that's just mb + + align:start position:0% + + + + align:start position:0% + +okay so + + align:start position:0% +okay so + + + align:start position:0% +okay so +actually p minus is equal to mb by + + align:start position:0% +actually p minus is equal to mb by + + + align:start position:0% +actually p minus is equal to mb by +kinematics + + align:start position:0% + + + + align:start position:0% + +so mb's in this + + align:start position:0% +so mb's in this + + + align:start position:0% +so mb's in this +result here you should think of as p + + align:start position:0% +result here you should think of as p + + + align:start position:0% +result here you should think of as p +minuses and that's + + align:start position:0% +minuses and that's + + + align:start position:0% +minuses and that's +the things that this p-bar that was in + + align:start position:0% +the things that this p-bar that was in + + + align:start position:0% +the things that this p-bar that was in +our wilson coefficient is just getting + + align:start position:0% +our wilson coefficient is just getting + + + align:start position:0% +our wilson coefficient is just getting +set to mb because of some delta + + align:start position:0% +set to mb because of some delta + + + align:start position:0% +set to mb because of some delta +functions that are specifying kinematics + + align:start position:0% +functions that are specifying kinematics + + + align:start position:0% +functions that are specifying kinematics +so that leaves the kind of one over + + align:start position:0% +so that leaves the kind of one over + + + align:start position:0% +so that leaves the kind of one over +epsilon terms + + align:start position:0% +epsilon terms + + + align:start position:0% +epsilon terms +and so what we'd like is that those + + align:start position:0% +and so what we'd like is that those + + + align:start position:0% +and so what we'd like is that those +terms are associated to normalization + + align:start position:0% + + + + align:start position:0% + +of the effective theory right i wrote + + align:start position:0% +of the effective theory right i wrote + + + align:start position:0% +of the effective theory right i wrote +that the factor theory was bare + + align:start position:0% + + + + align:start position:0% + +but if i want to do that then i have to + + align:start position:0% +but if i want to do that then i have to + + + align:start position:0% +but if i want to do that then i have to +ensure that all these epsilons that are + + align:start position:0% +ensure that all these epsilons that are + + + align:start position:0% +ensure that all these epsilons that are +appearing here + + align:start position:0% +appearing here + + + align:start position:0% +appearing here +are really ultraviolet divergences + + align:start position:0% +are really ultraviolet divergences + + + align:start position:0% +are really ultraviolet divergences +if they're + + align:start position:0% +if they're + + + align:start position:0% +if they're +infrared divergences then doing that + + align:start position:0% +infrared divergences then doing that + + + align:start position:0% +infrared divergences then doing that +doesn't make sense + + align:start position:0% +doesn't make sense + + + align:start position:0% +doesn't make sense +and that's actually + + align:start position:0% +and that's actually + + + align:start position:0% +and that's actually +the remaining issue that we have to deal + + align:start position:0% +the remaining issue that we have to deal + + + align:start position:0% +the remaining issue that we have to deal +with if i + + align:start position:0% +with if i + + + align:start position:0% +with if i +i just wrote epsilon that means i'm + + align:start position:0% +i just wrote epsilon that means i'm + + + align:start position:0% +i just wrote epsilon that means i'm +ignorant to what they are + + align:start position:0% +ignorant to what they are + + + align:start position:0% +ignorant to what they are +and if i i knew this one was epsilon ir + + align:start position:0% +and if i i knew this one was epsilon ir + + + align:start position:0% +and if i i knew this one was epsilon ir +because it came from the wave function + + align:start position:0% +because it came from the wave function + + + align:start position:0% +because it came from the wave function +or normalization of the heavy quark and + + align:start position:0% +or normalization of the heavy quark and + + + align:start position:0% +or normalization of the heavy quark and +that was the same on both sides it was + + align:start position:0% +that was the same on both sides it was + + + align:start position:0% +that was the same on both sides it was +the same diagram as the wave function + + align:start position:0% +the same diagram as the wave function + + + align:start position:0% +the same diagram as the wave function +realization diagram the full and the + + align:start position:0% +realization diagram the full and the + + + align:start position:0% +realization diagram the full and the +effective theory so i could match up + + align:start position:0% +effective theory so i could match up + + + align:start position:0% +effective theory so i could match up +that one + + align:start position:0% +that one + + + align:start position:0% +that one +these ones just came out + + align:start position:0% +these ones just came out + + + align:start position:0% +these ones just came out +but it turns out that so far with what + + align:start position:0% +but it turns out that so far with what + + + align:start position:0% +but it turns out that so far with what +we've done some of these epsilons here + + align:start position:0% +we've done some of these epsilons here + + + align:start position:0% +we've done some of these epsilons here +are ir + + align:start position:0% +are ir + + + align:start position:0% +are ir +and so the ir divergences aren't + + align:start position:0% +and so the ir divergences aren't + + + align:start position:0% +and so the ir divergences aren't +matching up + + align:start position:0% + + + + align:start position:0% + +and the reason is because we didn't put + + align:start position:0% +and the reason is because we didn't put + + + align:start position:0% +and the reason is because we didn't put +in those restrictions + + align:start position:0% +in those restrictions + + + align:start position:0% +in those restrictions +on our sum over labels + + align:start position:0% + + + + align:start position:0% + +uh + + align:start position:0% + + + + align:start position:0% + +okay so that we have these restrictions + + align:start position:0% +okay so that we have these restrictions + + + align:start position:0% +okay so that we have these restrictions +k label not equal to zero + + align:start position:0% +k label not equal to zero + + + align:start position:0% +k label not equal to zero +and k label not equal to minus pl + + align:start position:0% + + + + align:start position:0% + +those are the ones those are the + + align:start position:0% +those are the ones those are the + + + align:start position:0% +those are the ones those are the +restrictions that i'm talking about + + align:start position:0% +restrictions that i'm talking about + + + align:start position:0% +restrictions that i'm talking about +the place that those restrictions came + + align:start position:0% +the place that those restrictions came + + + align:start position:0% +the place that those restrictions came +from was kl was the + + align:start position:0% +from was kl was the + + + align:start position:0% +from was kl was the +k was the momentum of the gluon kl not + + align:start position:0% +k was the momentum of the gluon kl not + + + align:start position:0% +k was the momentum of the gluon kl not +equal to zero is saying that the gluon + + align:start position:0% +equal to zero is saying that the gluon + + + align:start position:0% +equal to zero is saying that the gluon +shouldn't be + + align:start position:0% +shouldn't be + + + align:start position:0% +shouldn't be +this is the restriction that the gluon + + align:start position:0% +this is the restriction that the gluon + + + align:start position:0% +this is the restriction that the gluon +is linear + + align:start position:0% + + + + align:start position:0% + +because kl equals 0 is the ultrasoft + + align:start position:0% +because kl equals 0 is the ultrasoft + + + align:start position:0% +because kl equals 0 is the ultrasoft +gluon + + align:start position:0% + + + + align:start position:0% + +and this is the restriction that the + + align:start position:0% +and this is the restriction that the + + + align:start position:0% +and this is the restriction that the +fermion is collinear + + align:start position:0% + + + + align:start position:0% + +in the loop + + align:start position:0% +in the loop + + + align:start position:0% +in the loop +that's why there was two of them + + align:start position:0% + + + + align:start position:0% + +so these are called zero bins + + align:start position:0% +so these are called zero bins + + + align:start position:0% +so these are called zero bins +zero because it's + + align:start position:0% +zero because it's + + + align:start position:0% +zero because it's +the where the ultrasoft momentum lives + + align:start position:0% +the where the ultrasoft momentum lives + + + align:start position:0% +the where the ultrasoft momentum lives +and that's kind of from the point of + + align:start position:0% +and that's kind of from the point of + + + align:start position:0% +and that's kind of from the point of +view of collinear that's zero + + align:start position:0% + + + + align:start position:0% + +so composing these restrictions is + + align:start position:0% +so composing these restrictions is + + + align:start position:0% +so composing these restrictions is +removing the zero bin if you like + + align:start position:0% +removing the zero bin if you like + + + align:start position:0% +removing the zero bin if you like +and what these restrictions do is they + + align:start position:0% +and what these restrictions do is they + + + align:start position:0% +and what these restrictions do is they +avoid double double counting + + align:start position:0% +avoid double double counting + + + align:start position:0% +avoid double double counting +and the way i've said it that's i think + + align:start position:0% +and the way i've said it that's i think + + + align:start position:0% +and the way i've said it that's i think +clearer + + align:start position:0% + + + + align:start position:0% + +so so far in our calculation we haven't + + align:start position:0% +so so far in our calculation we haven't + + + align:start position:0% +so so far in our calculation we haven't +avoided double counting and that's the + + align:start position:0% +avoided double counting and that's the + + + align:start position:0% +avoided double counting and that's the +problem + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% + + + + align:start position:0% + +okay so we have to modify our rule or we + + align:start position:0% +okay so we have to modify our rule or we + + + align:start position:0% +okay so we have to modify our rule or we +extend our rule to avoid to include the + + align:start position:0% +extend our rule to avoid to include the + + + align:start position:0% +extend our rule to avoid to include the +case where we have these restrictions + + align:start position:0% +case where we have these restrictions + + + align:start position:0% +case where we have these restrictions +so + + align:start position:0% + + + + align:start position:0% + +in an extended version of rule two + + align:start position:0% + + + + align:start position:0% + +that has restrictions + + align:start position:0% + + + + align:start position:0% + +so really what we want to do is that + + align:start position:0% +so really what we want to do is that + + + align:start position:0% +so really what we want to do is that +and we want to think about that as an + + align:start position:0% +and we want to think about that as an + + + align:start position:0% +and we want to think about that as an +integral + + align:start position:0% + + + + align:start position:0% + +so here's how we can manipulate these to + + align:start position:0% +so here's how we can manipulate these to + + + align:start position:0% +so here's how we can manipulate these to +think about it as an integral + + align:start position:0% +think about it as an integral + + + align:start position:0% +think about it as an integral +let's sum over all kls + + align:start position:0% + + + + align:start position:0% + +but then we'll + + align:start position:0% +but then we'll + + + align:start position:0% +but then we'll +subtract + + align:start position:0% + + + + align:start position:0% + +the sort of + + align:start position:0% + + + + align:start position:0% + +we'll subtract the limit of this f + + align:start position:0% +we'll subtract the limit of this f + + + align:start position:0% +we'll subtract the limit of this f +where we take the f and we we let the kl + + align:start position:0% +where we take the f and we we let the kl + + + align:start position:0% +where we take the f and we we let the kl +go to the the place so we integrate over + + align:start position:0% +go to the the place so we integrate over + + + align:start position:0% +go to the the place so we integrate over +everywhere including the place we don't + + align:start position:0% +everywhere including the place we don't + + + align:start position:0% +everywhere including the place we don't +want to go + + align:start position:0% +want to go + + + align:start position:0% +want to go +and we subtract the and then we subtract + + align:start position:0% +and we subtract the and then we subtract + + + align:start position:0% +and we subtract the and then we subtract +it back + + align:start position:0% + + + + align:start position:0% + +so what is this fl of k + + align:start position:0% + + + + align:start position:0% + +this f k l goes to zero + + align:start position:0% + + + + align:start position:0% + +it's defined by taking the scaling limit + + align:start position:0% +it's defined by taking the scaling limit + + + align:start position:0% +it's defined by taking the scaling limit +of the collinear momenta towards the + + align:start position:0% +of the collinear momenta towards the + + + align:start position:0% +of the collinear momenta towards the +ultra soft + + align:start position:0% + + + + align:start position:0% + +so you take your collinear momentum + + align:start position:0% +so you take your collinear momentum + + + align:start position:0% +so you take your collinear momentum +which are the plot minus and the perp + + align:start position:0% +which are the plot minus and the perp + + + align:start position:0% +which are the plot minus and the perp +here and you scale them towards the an + + align:start position:0% +here and you scale them towards the an + + + align:start position:0% +here and you scale them towards the an +ultrasoft momentum in whatever + + align:start position:0% +ultrasoft momentum in whatever + + + align:start position:0% +ultrasoft momentum in whatever +components + + align:start position:0% +components + + + align:start position:0% +components +i.e you start counting the k ends is + + align:start position:0% +i.e you start counting the k ends is + + + align:start position:0% +i.e you start counting the k ends is +water lambda squared + + align:start position:0% +water lambda squared + + + align:start position:0% +water lambda squared +and you keep the leading order piece + + align:start position:0% + + + + align:start position:0% + +or you keep the piece that's the same + + align:start position:0% +or you keep the piece that's the same + + + align:start position:0% +or you keep the piece that's the same +size as this term + + align:start position:0% + + + + align:start position:0% + +and then that defines what this + + align:start position:0% +and then that defines what this + + + align:start position:0% +and then that defines what this +f is it's the once you take that limit + + align:start position:0% +f is it's the once you take that limit + + + align:start position:0% +f is it's the once you take that limit +and you expand then that's what this f + + align:start position:0% +and you expand then that's what this f + + + align:start position:0% +and you expand then that's what this f +is + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +so what you're doing here by doing this + + align:start position:0% +so what you're doing here by doing this + + + align:start position:0% +so what you're doing here by doing this +procedure + + align:start position:0% +procedure + + + align:start position:0% +procedure +is you're basically setting things up so + + align:start position:0% +is you're basically setting things up so + + + align:start position:0% +is you're basically setting things up so +that + + align:start position:0% +that + + + align:start position:0% +that +this guy is integrated over in a way + + align:start position:0% +this guy is integrated over in a way + + + align:start position:0% +this guy is integrated over in a way +that we can combine back into an + + align:start position:0% +that we can combine back into an + + + align:start position:0% +that we can combine back into an +integral but then we have to subtract + + align:start position:0% +integral but then we have to subtract + + + align:start position:0% +integral but then we have to subtract +kind of an overlap + + align:start position:0% +kind of an overlap + + + align:start position:0% +kind of an overlap +of when that integral would go into the + + align:start position:0% +of when that integral would go into the + + + align:start position:0% +of when that integral would go into the +ultrasoft region + + align:start position:0% +ultrasoft region + + + align:start position:0% +ultrasoft region +but the overlap we're subtracting is + + align:start position:0% +but the overlap we're subtracting is + + + align:start position:0% +but the overlap we're subtracting is +also an integral + + align:start position:0% + + + + align:start position:0% + +so we have a difference of integrals + + align:start position:0% +so we have a difference of integrals + + + align:start position:0% +so we have a difference of integrals +and you should think of the second + + align:start position:0% +and you should think of the second + + + align:start position:0% +and you should think of the second +integral as kind of like the square + + align:start position:0% +integral as kind of like the square + + + align:start position:0% +integral as kind of like the square +integrating over the square where the + + align:start position:0% +integrating over the square where the + + + align:start position:0% +integrating over the square where the +zero bin was + + align:start position:0% +zero bin was + + + align:start position:0% +zero bin was +so if you think about our + + align:start position:0% +so if you think about our + + + align:start position:0% +so if you think about our +picture where the cleaners were up here + + align:start position:0% +picture where the cleaners were up here + + + align:start position:0% +picture where the cleaners were up here +the ultrasounds are down here and you + + align:start position:0% +the ultrasounds are down here and you + + + align:start position:0% +the ultrasounds are down here and you +thought about there being some box + + align:start position:0% +thought about there being some box + + + align:start position:0% +thought about there being some box +you're taking the scaling limit when + + align:start position:0% +you're taking the scaling limit when + + + align:start position:0% +you're taking the scaling limit when +this guy goes down into that box + + align:start position:0% +this guy goes down into that box + + + align:start position:0% +this guy goes down into that box +you add up all the boxes that's this + + align:start position:0% +you add up all the boxes that's this + + + align:start position:0% +you add up all the boxes that's this +and then you subtract out that box again + + align:start position:0% +and then you subtract out that box again + + + align:start position:0% +and then you subtract out that box again +and that avoids having a double counting + + align:start position:0% +and that avoids having a double counting + + + align:start position:0% +and that avoids having a double counting +in that region + + align:start position:0% + + + + align:start position:0% + +okay so then this guy here + + align:start position:0% +okay so then this guy here + + + align:start position:0% +okay so then this guy here +you can do the same kind of trick as + + align:start position:0% +you can do the same kind of trick as + + + align:start position:0% +you can do the same kind of trick as +before so + + align:start position:0% +before so + + + align:start position:0% +before so +continuing with the equation + + align:start position:0% + + + + align:start position:0% + +if kl is going to zero we can think of + + align:start position:0% +if kl is going to zero we can think of + + + align:start position:0% +if kl is going to zero we can think of +it just as a function of kr's + + align:start position:0% +it just as a function of kr's + + + align:start position:0% +it just as a function of kr's +and so effectively what we get in the + + align:start position:0% +and so effectively what we get in the + + + align:start position:0% +and so effectively what we get in the +end is an integral over all k + + align:start position:0% +end is an integral over all k + + + align:start position:0% +end is an integral over all k +of + + align:start position:0% +of + + + align:start position:0% +of +f of k the full f + + align:start position:0% +f of k the full f + + + align:start position:0% +f of k the full f +evaluated with a continuous momentum + + align:start position:0% +evaluated with a continuous momentum + + + align:start position:0% +evaluated with a continuous momentum +minus some f + + align:start position:0% +minus some f + + + align:start position:0% +minus some f +that's expanded + + align:start position:0% +that's expanded + + + align:start position:0% +that's expanded +and avoids there being overlap in this + + align:start position:0% +and avoids there being overlap in this + + + align:start position:0% +and avoids there being overlap in this +box + + align:start position:0% +box + + + align:start position:0% +box +so rather than having this discrete sum + + align:start position:0% +so rather than having this discrete sum + + + align:start position:0% +so rather than having this discrete sum +with the restriction we have a + + align:start position:0% +with the restriction we have a + + + align:start position:0% +with the restriction we have a +difference of integrals and this + + align:start position:0% +difference of integrals and this + + + align:start position:0% +difference of integrals and this +subtraction term avoids + + align:start position:0% +subtraction term avoids + + + align:start position:0% +subtraction term avoids +the overlap in that region + + align:start position:0% +the overlap in that region + + + align:start position:0% +the overlap in that region +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so all the discrete sums are good for is + + align:start position:0% +so all the discrete sums are good for is + + + align:start position:0% +so all the discrete sums are good for is +a means of + + align:start position:0% +a means of + + + align:start position:0% +a means of +figuring out what limits you need to + + align:start position:0% +figuring out what limits you need to + + + align:start position:0% +figuring out what limits you need to +take to generate these subtractions once + + align:start position:0% +take to generate these subtractions once + + + align:start position:0% +take to generate these subtractions once +you've done that everything's a + + align:start position:0% +you've done that everything's a + + + align:start position:0% +you've done that everything's a +continuous integral + + align:start position:0% + + + + align:start position:0% + +and this is called the zero bin + + align:start position:0% +and this is called the zero bin + + + align:start position:0% +and this is called the zero bin +subtraction + + align:start position:0% + + + + align:start position:0% + +okay so if you like one way of phrasing + + align:start position:0% +okay so if you like one way of phrasing + + + align:start position:0% +okay so if you like one way of phrasing +what's going on is that the linear + + align:start position:0% +what's going on is that the linear + + + align:start position:0% +what's going on is that the linear +propagators are really distributions + + align:start position:0% +propagators are really distributions + + + align:start position:0% +propagators are really distributions +they're distributions that + + align:start position:0% +they're distributions that + + + align:start position:0% +they're distributions that +know that there should be that they + + align:start position:0% +know that there should be that they + + + align:start position:0% +know that there should be that they +should have a subtraction in order to + + align:start position:0% +should have a subtraction in order to + + + align:start position:0% +should have a subtraction in order to +not overlap the other region where we + + align:start position:0% +not overlap the other region where we + + + align:start position:0% +not overlap the other region where we +have another degree of freedom + + align:start position:0% +have another degree of freedom + + + align:start position:0% +have another degree of freedom +so you could think about it that way in + + align:start position:0% +so you could think about it that way in + + + align:start position:0% +so you could think about it that way in +this having this sum + + align:start position:0% +this having this sum + + + align:start position:0% +this having this sum +is just a way of sort of encoding that + + align:start position:0% +is just a way of sort of encoding that + + + align:start position:0% +is just a way of sort of encoding that +but in the end it kind of looks like + + align:start position:0% +but in the end it kind of looks like + + + align:start position:0% +but in the end it kind of looks like +some kind of plus function where you + + align:start position:0% +some kind of plus function where you + + + align:start position:0% +some kind of plus function where you +have a subtraction + + align:start position:0% +have a subtraction + + + align:start position:0% +have a subtraction +so it seems like in the second term + + align:start position:0% +so it seems like in the second term + + + align:start position:0% +so it seems like in the second term +you would have to rewrite the expression + + align:start position:0% +you would have to rewrite the expression + + + align:start position:0% +you would have to rewrite the expression +because initially you know okay you + + align:start position:0% +because initially you know okay you + + + align:start position:0% +because initially you know okay you +ignore yeah + + align:start position:0% +ignore yeah + + + align:start position:0% +ignore yeah +i'll show you how it works in an example + + align:start position:0% + + + + align:start position:0% + +so let's go to our example + + align:start position:0% + + + + align:start position:0% + +yeah it's not so what you just said is + + align:start position:0% +yeah it's not so what you just said is + + + align:start position:0% +yeah it's not so what you just said is +not quite the way you should think about + + align:start position:0% +not quite the way you should think about + + + align:start position:0% +not quite the way you should think about +it you should think about it you're + + align:start position:0% +it you should think about it you're + + + align:start position:0% +it you should think about it you're +given the effect of theory f + + align:start position:0% +given the effect of theory f + + + align:start position:0% +given the effect of theory f +and now i'm + + align:start position:0% +and now i'm + + + align:start position:0% +and now i'm +saying that that f as given with its + + align:start position:0% +saying that that f as given with its + + + align:start position:0% +saying that that f as given with its +momentum as given has it still has an + + align:start position:0% +momentum as given has it still has an + + + align:start position:0% +momentum as given has it still has an +overlap with the ultrasoft region that i + + align:start position:0% +overlap with the ultrasoft region that i + + + align:start position:0% +overlap with the ultrasoft region that i +want to subtract + + align:start position:0% +want to subtract + + + align:start position:0% +want to subtract +so i'm taking a limit of that f i'm not + + align:start position:0% +so i'm taking a limit of that f i'm not + + + align:start position:0% +so i'm taking a limit of that f i'm not +adding anything back to it + + align:start position:0% + + + + align:start position:0% + +so this guy + + align:start position:0% +so this guy + + + align:start position:0% +so this guy +don't integral dk + + align:start position:0% + + + + align:start position:0% + +so this is what we wrote before + + align:start position:0% + + + + align:start position:0% + +and now if i take the ultrasoft limit of + + align:start position:0% +and now if i take the ultrasoft limit of + + + align:start position:0% +and now if i take the ultrasoft limit of +it + + align:start position:0% +it + + + align:start position:0% +it +of the k + + align:start position:0% +of the k + + + align:start position:0% +of the k +then i would write this + + align:start position:0% + + + + align:start position:0% + +okay so + + align:start position:0% +okay so + + + align:start position:0% +okay so +when i take the scaling limit + + align:start position:0% +when i take the scaling limit + + + align:start position:0% +when i take the scaling limit +if you think about k squared it's k plus + + align:start position:0% +if you think about k squared it's k plus + + + align:start position:0% +if you think about k squared it's k plus +k minus minus k perp squared + + align:start position:0% +k minus minus k perp squared + + + align:start position:0% +k minus minus k perp squared +when i take the scaling limit of all + + align:start position:0% +when i take the scaling limit of all + + + align:start position:0% +when i take the scaling limit of all +momentum being ultrasoft the components + + align:start position:0% +momentum being ultrasoft the components + + + align:start position:0% +momentum being ultrasoft the components +of the k are still homogeneous so + + align:start position:0% +of the k are still homogeneous so + + + align:start position:0% +of the k are still homogeneous so +there's nothing there to expand + + align:start position:0% +there's nothing there to expand + + + align:start position:0% +there's nothing there to expand +some expansion happened in this k plus p + + align:start position:0% +some expansion happened in this k plus p + + + align:start position:0% +some expansion happened in this k plus p +term + + align:start position:0% +term + + + align:start position:0% +term +1 over mbar.k changes its power counting + + align:start position:0% +1 over mbar.k changes its power counting + + + align:start position:0% +1 over mbar.k changes its power counting +but + + align:start position:0% +but + + + align:start position:0% +but +uh it's still mbar.k and we don't + + align:start position:0% +uh it's still mbar.k and we don't + + + align:start position:0% +uh it's still mbar.k and we don't +there's nothing to expand there so this + + align:start position:0% +there's nothing to expand there so this + + + align:start position:0% +there's nothing to expand there so this +is what the subtraction looks like and + + align:start position:0% +is what the subtraction looks like and + + + align:start position:0% +is what the subtraction looks like and +in the numerator the nbar.k can be + + align:start position:0% +in the numerator the nbar.k can be + + + align:start position:0% +in the numerator the nbar.k can be +dropped relative to the mbar.p which is + + align:start position:0% +dropped relative to the mbar.p which is + + + align:start position:0% +dropped relative to the mbar.p which is +large and external + + align:start position:0% + + + + align:start position:0% + +okay so this is taking the ultrasoft + + align:start position:0% +okay so this is taking the ultrasoft + + + align:start position:0% +okay so this is taking the ultrasoft +limit of this + + align:start position:0% + + + + align:start position:0% + +yeah so in general i would have to + + align:start position:0% +yeah so in general i would have to + + + align:start position:0% +yeah so in general i would have to +subtract off the ultrasoft limit of the + + align:start position:0% +subtract off the ultrasoft limit of the + + + align:start position:0% +subtract off the ultrasoft limit of the +cork as well + + align:start position:0% +cork as well + + + align:start position:0% +cork as well +and when i do that what i find is a term + + align:start position:0% +and when i do that what i find is a term + + + align:start position:0% +and when i do that what i find is a term +that's power suppressed and i so i drop + + align:start position:0% +that's power suppressed and i so i drop + + + align:start position:0% +that's power suppressed and i so i drop +it + + align:start position:0% +it + + + align:start position:0% +it +but in general i would have to do that + + align:start position:0% +but in general i would have to do that + + + align:start position:0% +but in general i would have to do that +as well that's right + + align:start position:0% +as well that's right + + + align:start position:0% +as well that's right +um + + align:start position:0% +um + + + align:start position:0% +um +and so this is you know it looks kind of + + align:start position:0% +and so this is you know it looks kind of + + + align:start position:0% +and so this is you know it looks kind of +like an ultra soft diagram except it's + + align:start position:0% +like an ultra soft diagram except it's + + + align:start position:0% +like an ultra soft diagram except it's +got this n bar dot k and + + align:start position:0% +got this n bar dot k and + + + align:start position:0% +got this n bar dot k and +instead of the v dot k that we had in + + align:start position:0% +instead of the v dot k that we had in + + + align:start position:0% +instead of the v dot k that we had in +the ultra soft diagram + + align:start position:0% +the ultra soft diagram + + + align:start position:0% +the ultra soft diagram +um + + align:start position:0% +um + + + align:start position:0% +um +and if you do a power counting with the + + align:start position:0% +and if you do a power counting with the + + + align:start position:0% +and if you do a power counting with the +loop momentum scaling as ultrasoft then + + align:start position:0% +loop momentum scaling as ultrasoft then + + + align:start position:0% +loop momentum scaling as ultrasoft then +you're this pieces of order the same + + align:start position:0% +you're this pieces of order the same + + + align:start position:0% +you're this pieces of order the same +size as this piece and that's why you + + align:start position:0% +size as this piece and that's why you + + + align:start position:0% +size as this piece and that's why you +keep only that term + + align:start position:0% + + + + align:start position:0% + +no + + align:start position:0% +no + + + align:start position:0% +no +so the prescription we have is that we + + align:start position:0% +so the prescription we have is that we + + + align:start position:0% +so the prescription we have is that we +drop the higher powers + + align:start position:0% + + + + align:start position:0% + +oh if you did the higher power lower + + align:start position:0% +oh if you did the higher power lower + + + align:start position:0% +oh if you did the higher power lower +power + + align:start position:0% +power + + + align:start position:0% +power +higher power zero no + + align:start position:0% +higher power zero no + + + align:start position:0% +higher power zero no +so if we did the higher power then this + + align:start position:0% +so if we did the higher power then this + + + align:start position:0% +so if we did the higher power then this +would start out with higher power + + align:start position:0% +would start out with higher power + + + align:start position:0% +would start out with higher power +and then when we took the limit of it it + + align:start position:0% +and then when we took the limit of it it + + + align:start position:0% +and then when we took the limit of it it +would end up you know just starting at + + align:start position:0% +would end up you know just starting at + + + align:start position:0% +would end up you know just starting at +that power or higher + + align:start position:0% + + + + align:start position:0% + +yeah you don't have to you don't have to + + align:start position:0% +yeah you don't have to you don't have to + + + align:start position:0% +yeah you don't have to you don't have to +no + + align:start position:0% +no + + + align:start position:0% +no +no + + align:start position:0% +no + + + align:start position:0% +no +yeah + + align:start position:0% + + + + align:start position:0% + +yeah so it's kind of really what you + + align:start position:0% +yeah so it's kind of really what you + + + align:start position:0% +yeah so it's kind of really what you +care about subtracting here are the log + + align:start position:0% +care about subtracting here are the log + + + align:start position:0% +care about subtracting here are the log +divergences + + align:start position:0% +divergences + + + align:start position:0% +divergences +and that's what this minimal subtraction + + align:start position:0% +and that's what this minimal subtraction + + + align:start position:0% +and that's what this minimal subtraction +is doing by taking the piece that you're + + align:start position:0% +is doing by taking the piece that you're + + + align:start position:0% +is doing by taking the piece that you're +only keeping the piece that's scaling + + align:start position:0% +only keeping the piece that's scaling + + + align:start position:0% +only keeping the piece that's scaling +the same way you're removing the log + + align:start position:0% +the same way you're removing the log + + + align:start position:0% +the same way you're removing the log +divergent pieces + + align:start position:0% +divergent pieces + + + align:start position:0% +divergent pieces +and it's the log divergent pieces which + + align:start position:0% +and it's the log divergent pieces which + + + align:start position:0% +and it's the log divergent pieces which +are giving our one over epsilons + + align:start position:0% +are giving our one over epsilons + + + align:start position:0% +are giving our one over epsilons +um the pieces that you would get from + + align:start position:0% +um the pieces that you would get from + + + align:start position:0% +um the pieces that you would get from +the higher expansion + + align:start position:0% +the higher expansion + + + align:start position:0% +the higher expansion +you know they would all be kind of like + + align:start position:0% +you know they would all be kind of like + + + align:start position:0% +you know they would all be kind of like +power law divergent terms from the point + + align:start position:0% +power law divergent terms from the point + + + align:start position:0% +power law divergent terms from the point +of view of the power counting and we + + align:start position:0% +of view of the power counting and we + + + align:start position:0% +of view of the power counting and we +just don't have to worry about those + + align:start position:0% +just don't have to worry about those + + + align:start position:0% +just don't have to worry about those +and another way of saying it is you know + + align:start position:0% +and another way of saying it is you know + + + align:start position:0% +and another way of saying it is you know +it's not that i'm removing absolutely + + align:start position:0% +it's not that i'm removing absolutely + + + align:start position:0% +it's not that i'm removing absolutely +this whole integrand in that region + + align:start position:0% +this whole integrand in that region + + + align:start position:0% +this whole integrand in that region +right there could still be a constant + + align:start position:0% +right there could still be a constant + + + align:start position:0% +right there could still be a constant +for example that comes from that region + + align:start position:0% +for example that comes from that region + + + align:start position:0% +for example that comes from that region +but if there's a constant that comes + + align:start position:0% +but if there's a constant that comes + + + align:start position:0% +but if there's a constant that comes +from that region i don't care what i + + align:start position:0% +from that region i don't care what i + + + align:start position:0% +from that region i don't care what i +care about removing is any spurious ir + + align:start position:0% +care about removing is any spurious ir + + + align:start position:0% +care about removing is any spurious ir +singularities + + align:start position:0% +singularities + + + align:start position:0% +singularities +and for those i can make a kind of + + align:start position:0% +and for those i can make a kind of + + + align:start position:0% +and for those i can make a kind of +minimal subtraction which is just the + + align:start position:0% +minimal subtraction which is just the + + + align:start position:0% +minimal subtraction which is just the +first + + align:start position:0% +first + + + align:start position:0% +first +term all right so + + align:start position:0% +term all right so + + + align:start position:0% +term all right so +i want to finish this discussion so if + + align:start position:0% +i want to finish this discussion so if + + + align:start position:0% +i want to finish this discussion so if +we do this we get an answer + + align:start position:0% +we do this we get an answer + + + align:start position:0% +we do this we get an answer +which is + + align:start position:0% + + + + align:start position:0% + +i will try + + align:start position:0% +i will try + + + align:start position:0% +i will try +to right on the board for you + + align:start position:0% + + + + align:start position:0% + +so now i'm going to distinguish all the + + align:start position:0% +so now i'm going to distinguish all the + + + align:start position:0% +so now i'm going to distinguish all the +the epsilons and then we'll see what the + + align:start position:0% +the epsilons and then we'll see what the + + + align:start position:0% +the epsilons and then we'll see what the +subtraction does + + align:start position:0% + + + + align:start position:0% + +so if i was careful and i distinguished + + align:start position:0% +so if i was careful and i distinguished + + + align:start position:0% +so if i was careful and i distinguished +all the epsilons in our original + + align:start position:0% +all the epsilons in our original + + + align:start position:0% +all the epsilons in our original +calculation + + align:start position:0% +calculation + + + align:start position:0% +calculation +it would actually look like this + + align:start position:0% +it would actually look like this + + + align:start position:0% +it would actually look like this +and then the subtraction piece + + align:start position:0% +and then the subtraction piece + + + align:start position:0% +and then the subtraction piece +gives an extra + + align:start position:0% + + + + align:start position:0% + +contribution and it's actually scaleless + + align:start position:0% + + + + align:start position:0% + +in in the mbar.k here it's so it's + + align:start position:0% + + + + align:start position:0% + +there's a scaleless loop in this in this + + align:start position:0% +there's a scaleless loop in this in this + + + align:start position:0% +there's a scaleless loop in this in this +guy + + align:start position:0% + + + + align:start position:0% + +so it + + align:start position:0% + + + + align:start position:0% + +it actually vanishes if the epsilon ir + + align:start position:0% +it actually vanishes if the epsilon ir + + + align:start position:0% +it actually vanishes if the epsilon ir +and the epsilon uv are said to be equal + + align:start position:0% +and the epsilon uv are said to be equal + + + align:start position:0% +and the epsilon uv are said to be equal +but what it does is it converts the + + align:start position:0% +but what it does is it converts the + + + align:start position:0% +but what it does is it converts the +epsilon irs that are in the first + + align:start position:0% +epsilon irs that are in the first + + + align:start position:0% +epsilon irs that are in the first +expression + + align:start position:0% +expression + + + align:start position:0% +expression +into epsilon uvs which is what we want + + align:start position:0% +into epsilon uvs which is what we want + + + align:start position:0% +into epsilon uvs which is what we want +so once you add up these two things the + + align:start position:0% +so once you add up these two things the + + + align:start position:0% +so once you add up these two things the +epsilon irs are canceling and the + + align:start position:0% +epsilon irs are canceling and the + + + align:start position:0% +epsilon irs are canceling and the +epsilon irs that were coming in the + + align:start position:0% +epsilon irs that were coming in the + + + align:start position:0% +epsilon irs that were coming in the +original formula + + align:start position:0% +original formula + + + align:start position:0% +original formula +those were coming about because of this + + align:start position:0% +those were coming about because of this + + + align:start position:0% +those were coming about because of this +bad behavior as nbar.k goes kind of into + + align:start position:0% +bad behavior as nbar.k goes kind of into + + + align:start position:0% +bad behavior as nbar.k goes kind of into +the ultrasound into the limit of sort of + + align:start position:0% +the ultrasound into the limit of sort of + + + align:start position:0% +the ultrasound into the limit of sort of +mr.k going small you can think about + + align:start position:0% +mr.k going small you can think about + + + align:start position:0% +mr.k going small you can think about +that roughly is where the ultrasoft is + + align:start position:0% +that roughly is where the ultrasoft is + + + align:start position:0% +that roughly is where the ultrasoft is +this is kind of subtracting off that + + align:start position:0% +this is kind of subtracting off that + + + align:start position:0% +this is kind of subtracting off that +behavior + + align:start position:0% +behavior + + + align:start position:0% +behavior +and the remainder then is coming from + + align:start position:0% +and the remainder then is coming from + + + align:start position:0% +and the remainder then is coming from +you're only having divergences for sort + + align:start position:0% +you're only having divergences for sort + + + align:start position:0% +you're only having divergences for sort +of n bar dot k goes to infinity which is + + align:start position:0% +of n bar dot k goes to infinity which is + + + align:start position:0% +of n bar dot k goes to infinity which is +a sort of proper collinear + + align:start position:0% +a sort of proper collinear + + + align:start position:0% +a sort of proper collinear +ultraviolet divergence not from mbar.k + + align:start position:0% +ultraviolet divergence not from mbar.k + + + align:start position:0% +ultraviolet divergence not from mbar.k +going to zero + + align:start position:0% +going to zero + + + align:start position:0% +going to zero +so once you put the two together the + + align:start position:0% +so once you put the two together the + + + align:start position:0% +so once you put the two together the +epsilon irs cancel and then we get + + align:start position:0% +epsilon irs cancel and then we get + + + align:start position:0% +epsilon irs cancel and then we get +exactly actually the same expression we + + align:start position:0% +exactly actually the same expression we + + + align:start position:0% +exactly actually the same expression we +had + + align:start position:0% +had + + + align:start position:0% +had +before but where all those one over + + align:start position:0% +before but where all those one over + + + align:start position:0% +before but where all those one over +epsilons are one over epsilon uvs + + align:start position:0% + + + + align:start position:0% + +from both terms so they both have + + align:start position:0% +from both terms so they both have + + + align:start position:0% +from both terms so they both have +epsilon irs but they cancel between them + + align:start position:0% + + + + align:start position:0% + +yeah and the remainder is just epsilon + + align:start position:0% +yeah and the remainder is just epsilon + + + align:start position:0% +yeah and the remainder is just epsilon +uv so all the epsilons that i wrote my + + align:start position:0% +uv so all the epsilons that i wrote my + + + align:start position:0% +uv so all the epsilons that i wrote my +earlier formula would be now epsilon uvs + + align:start position:0% +earlier formula would be now epsilon uvs + + + align:start position:0% +earlier formula would be now epsilon uvs +once i take into account the subtraction + + align:start position:0% +once i take into account the subtraction + + + align:start position:0% +once i take into account the subtraction +so i could have just ignored the + + align:start position:0% +so i could have just ignored the + + + align:start position:0% +so i could have just ignored the +subtraction and that's a lot often what + + align:start position:0% +subtraction and that's a lot often what + + + align:start position:0% +subtraction and that's a lot often what +people do once if they know that this is + + align:start position:0% +people do once if they know that this is + + + align:start position:0% +people do once if they know that this is +that the zero bins are kind of giving a + + align:start position:0% +that the zero bins are kind of giving a + + + align:start position:0% +that the zero bins are kind of giving a +scalar integral they say well let's + + align:start position:0% +scalar integral they say well let's + + + align:start position:0% +scalar integral they say well let's +ignore the subtraction we'll just say + + align:start position:0% +ignore the subtraction we'll just say + + + align:start position:0% +ignore the subtraction we'll just say +that all the epsilons are uv + + align:start position:0% +that all the epsilons are uv + + + align:start position:0% +that all the epsilons are uv +and the zero bin makes them uv + + align:start position:0% +and the zero bin makes them uv + + + align:start position:0% +and the zero bin makes them uv +but if we really want to look and see + + align:start position:0% +but if we really want to look and see + + + align:start position:0% +but if we really want to look and see +that things are working properly we + + align:start position:0% +that things are working properly we + + + align:start position:0% +that things are working properly we +should + + align:start position:0% +should + + + align:start position:0% +should +take the subtraction and calculate it + + align:start position:0% +take the subtraction and calculate it + + + align:start position:0% +take the subtraction and calculate it +and make sure that that's true + + align:start position:0% +and make sure that that's true + + + align:start position:0% +and make sure that that's true +but we could have just taken the answer + + align:start position:0% +but we could have just taken the answer + + + align:start position:0% +but we could have just taken the answer +that i wrote down earlier and said those + + align:start position:0% +that i wrote down earlier and said those + + + align:start position:0% +that i wrote down earlier and said those +epsilons are ultraviolet and let's throw + + align:start position:0% +epsilons are ultraviolet and let's throw + + + align:start position:0% +epsilons are ultraviolet and let's throw +them in a counter term and calculate an + + align:start position:0% +them in a counter term and calculate an + + + align:start position:0% +them in a counter term and calculate an +almost dimension and that is indeed so + + align:start position:0% +almost dimension and that is indeed so + + + align:start position:0% +almost dimension and that is indeed so +we'll go we'll proceed that way next + + align:start position:0% +we'll go we'll proceed that way next + + + align:start position:0% +we'll go we'll proceed that way next +time but we now know that actually they + + align:start position:0% +time but we now know that actually they + + + align:start position:0% +time but we now know that actually they +are + + align:start position:0% +are + + + align:start position:0% +are +ultraviolet divergences + + align:start position:0% +ultraviolet divergences + + + align:start position:0% +ultraviolet divergences +so next time we'll take that that count + + align:start position:0% +so next time we'll take that that count + + + align:start position:0% +so next time we'll take that that count +the ultraviolet divergences and we'll + + align:start position:0% +the ultraviolet divergences and we'll + + + align:start position:0% +the ultraviolet divergences and we'll +define from them a counter term + + align:start position:0% +define from them a counter term + + + align:start position:0% +define from them a counter term +and we'll see how we get an almost + + align:start position:0% +and we'll see how we get an almost + + + align:start position:0% +and we'll see how we get an almost +dimension and what kind of logs + + align:start position:0% +dimension and what kind of logs + + + align:start position:0% +dimension and what kind of logs +we sum by using that in anomalous + + align:start position:0% +we sum by using that in anomalous + + + align:start position:0% +we sum by using that in anomalous +dimension + + align:start position:0% + + + + align:start position:0% + +so the zero bin that that's scalars in + + align:start position:0% +so the zero bin that that's scalars in + + + align:start position:0% +so the zero bin that that's scalars in +this particular example is not always + + align:start position:0% +this particular example is not always + + + align:start position:0% +this particular example is not always +scaleless so sometimes it could give the + + align:start position:0% +scaleless so sometimes it could give the + + + align:start position:0% +scaleless so sometimes it could give the +non depends on the problem you're + + align:start position:0% +non depends on the problem you're + + + align:start position:0% +non depends on the problem you're +dealing with so + + align:start position:0% +dealing with so + + + align:start position:0% +dealing with so +if you're + + align:start position:0% +if you're + + + align:start position:0% +if you're +sometimes you can set things up so + + align:start position:0% +sometimes you can set things up so + + + align:start position:0% +sometimes you can set things up so +that's scalise and then you just + + align:start position:0% +that's scalise and then you just + + + align:start position:0% +that's scalise and then you just +basically can ignore it + + align:start position:0% +basically can ignore it + + + align:start position:0% +basically can ignore it +but that's not always true so you do + + align:start position:0% +but that's not always true so you do + + + align:start position:0% +but that's not always true so you do +have to think about whether it's really + + align:start position:0% +have to think about whether it's really + + + align:start position:0% +have to think about whether it's really +going to be true for what you're doing + + align:start position:0% +going to be true for what you're doing + + + align:start position:0% +going to be true for what you're doing +if it is true then you can ignore then + + align:start position:0% +if it is true then you can ignore then + + + align:start position:0% +if it is true then you can ignore then +you could effectively ignore it because + + align:start position:0% +you could effectively ignore it because + + + align:start position:0% +you could effectively ignore it because +it's sort of just + + align:start position:0% +it's sort of just + + + align:start position:0% +it's sort of just +making the physics come out right making + + align:start position:0% +making the physics come out right making + + + align:start position:0% +making the physics come out right making +sure there's no overlap but if your + + align:start position:0% +sure there's no overlap but if your + + + align:start position:0% +sure there's no overlap but if your +regulator is set up so that it's + + align:start position:0% +regulator is set up so that it's + + + align:start position:0% +regulator is set up so that it's +scaleless you can kind of just + + align:start position:0% +scaleless you can kind of just + + + align:start position:0% +scaleless you can kind of just +get around it but in general that might + + align:start position:0% +get around it but in general that might + + + align:start position:0% +get around it but in general that might +not be true + + align:start position:0% +not be true + + + align:start position:0% +not be true +if you had more scales in the problem if + + align:start position:0% +if you had more scales in the problem if + + + align:start position:0% +if you had more scales in the problem if +you're doing some calculation that had + + align:start position:0% +you're doing some calculation that had + + + align:start position:0% +you're doing some calculation that had +some + + align:start position:0% +some + + + align:start position:0% +some +jets a finite size then + + align:start position:0% +jets a finite size then + + + align:start position:0% +jets a finite size then +that won't be true + + align:start position:0% +that won't be true + + + align:start position:0% +that won't be true +typically \ No newline at end of file diff --git a/q2mz6LZVnT8.txt b/q2mz6LZVnT8.txt new file mode 100644 index 0000000000000000000000000000000000000000..340111353242488f22b3b84d6b19e114d5783a54 --- /dev/null +++ b/q2mz6LZVnT8.txt @@ -0,0 +1,1531 @@ +align:start position:0% + +we're talking today about the role that + + align:start position:0% +we're talking today about the role that + + + align:start position:0% +we're talking today about the role that +shaping the future work + + align:start position:0% +shaping the future work + + + align:start position:0% +shaping the future work +we're talking with Professor Scott's + + align:start position:0% +we're talking with Professor Scott's + + + align:start position:0% +we're talking with Professor Scott's +turn the chair of our Sloan schools + + align:start position:0% +turn the chair of our Sloan schools + + + align:start position:0% +turn the chair of our Sloan schools +technological innovation + + align:start position:0% +technological innovation + + + align:start position:0% +technological innovation +entrepreneurship and strategy group and + + align:start position:0% +entrepreneurship and strategy group and + + + align:start position:0% +entrepreneurship and strategy group and +with Barbara Dyer the president of + + align:start position:0% +with Barbara Dyer the president of + + + align:start position:0% +with Barbara Dyer the president of +Hitachi foundation the foundation works + + align:start position:0% +Hitachi foundation the foundation works + + + align:start position:0% +Hitachi foundation the foundation works +with entrepreneurs to build both good + + align:start position:0% +with entrepreneurs to build both good + + + align:start position:0% +with entrepreneurs to build both good +companies that are financially + + align:start position:0% +companies that are financially + + + align:start position:0% +companies that are financially +successful as well as ones that provide + + align:start position:0% +successful as well as ones that provide + + + align:start position:0% +successful as well as ones that provide +good job opportunities can entrepreneurs + + align:start position:0% +good job opportunities can entrepreneurs + + + align:start position:0% +good job opportunities can entrepreneurs +build a good job strategy creating good + + align:start position:0% +build a good job strategy creating good + + + align:start position:0% +build a good job strategy creating good +opportunities for the full workforce in + + align:start position:0% +opportunities for the full workforce in + + + align:start position:0% +opportunities for the full workforce in +from the beginning so I think one of the + + align:start position:0% +from the beginning so I think one of the + + + align:start position:0% +from the beginning so I think one of the +greatest misconceptions is that being a + + align:start position:0% +greatest misconceptions is that being a + + + align:start position:0% +greatest misconceptions is that being a +good entrepreneur and building a company + + align:start position:0% +good entrepreneur and building a company + + + align:start position:0% +good entrepreneur and building a company +that really scales is actually in + + align:start position:0% +that really scales is actually in + + + align:start position:0% +that really scales is actually in +opposition to building a company that + + align:start position:0% +opposition to building a company that + + + align:start position:0% +opposition to building a company that +creates great jobs in fact I'd claim + + align:start position:0% +creates great jobs in fact I'd claim + + + align:start position:0% +creates great jobs in fact I'd claim +that exactly the reverse is true to + + align:start position:0% +that exactly the reverse is true to + + + align:start position:0% +that exactly the reverse is true to +attract the really best people to really + + align:start position:0% +attract the really best people to really + + + align:start position:0% +attract the really best people to really +create meaningful innovative value for + + align:start position:0% +create meaningful innovative value for + + + align:start position:0% +create meaningful innovative value for +consumers to really be in a situation + + align:start position:0% +consumers to really be in a situation + + + align:start position:0% +consumers to really be in a situation +where ultimately you are able to charge + + align:start position:0% +where ultimately you are able to charge + + + align:start position:0% +where ultimately you are able to charge +a price well above your cost and create + + align:start position:0% +a price well above your cost and create + + + align:start position:0% +a price well above your cost and create +that kind of value means that you need + + align:start position:0% +that kind of value means that you need + + + align:start position:0% +that kind of value means that you need +to be attracting nurturing investing in + + align:start position:0% +to be attracting nurturing investing in + + + align:start position:0% +to be attracting nurturing investing in +employees in meaningful ways if everyone + + align:start position:0% +employees in meaningful ways if everyone + + + align:start position:0% +employees in meaningful ways if everyone +who shows up to your company is simply + + align:start position:0% +who shows up to your company is simply + + + align:start position:0% +who shows up to your company is simply +you all it is about cost well then + + align:start position:0% +you all it is about cost well then + + + align:start position:0% +you all it is about cost well then +there's not much of a company at all + + align:start position:0% +there's not much of a company at all + + + align:start position:0% +there's not much of a company at all +there's not much of an organization + + align:start position:0% +there's not much of an organization + + + align:start position:0% +there's not much of an organization +there what we've observed at the nearly + + align:start position:0% +there what we've observed at the nearly + + + align:start position:0% +there what we've observed at the nearly +100 companies that we've looked at + + align:start position:0% +100 companies that we've looked at + + + align:start position:0% +100 companies that we've looked at +across healthcare and manufacturing is + + align:start position:0% +across healthcare and manufacturing is + + + align:start position:0% +across healthcare and manufacturing is +it the businesses that create great + + align:start position:0% +it the businesses that create great + + + align:start position:0% +it the businesses that create great +quality jobs don't begin with the + + align:start position:0% +quality jobs don't begin with the + + + align:start position:0% +quality jobs don't begin with the +premise that this is a good HR strategy + + align:start position:0% +premise that this is a good HR strategy + + + align:start position:0% +premise that this is a good HR strategy +they start with what is excellence and + + align:start position:0% +they start with what is excellence and + + + align:start position:0% +they start with what is excellence and +they very quickly figure out that the + + align:start position:0% +they very quickly figure out that the + + + align:start position:0% +they very quickly figure out that the +workforce piece of it is a critical part + + align:start position:0% +workforce piece of it is a critical part + + + align:start position:0% +workforce piece of it is a critical part +of operations they have to invest in + + align:start position:0% +of operations they have to invest in + + + align:start position:0% +of operations they have to invest in +their people and they have to create + + align:start position:0% +their people and they have to create + + + align:start position:0% +their people and they have to create +systems to provide ongoing support + + align:start position:0% +systems to provide ongoing support + + + align:start position:0% +systems to provide ongoing support +ongoing learning ongoing incentives so + + align:start position:0% +ongoing learning ongoing incentives so + + + align:start position:0% +ongoing learning ongoing incentives so +that their people are really delivering + + align:start position:0% +that their people are really delivering + + + align:start position:0% +that their people are really delivering +in the best possible way we hear that + + align:start position:0% +in the best possible way we hear that + + + align:start position:0% +in the best possible way we hear that +many investors have a mindset that labor + + align:start position:0% +many investors have a mindset that labor + + + align:start position:0% +many investors have a mindset that labor +is a cost + + align:start position:0% +is a cost + + + align:start position:0% +is a cost +minimized and and put a lot of pressure + + align:start position:0% +minimized and and put a lot of pressure + + + align:start position:0% +minimized and and put a lot of pressure +on entrepreneurs how can we overcome + + align:start position:0% +on entrepreneurs how can we overcome + + + align:start position:0% +on entrepreneurs how can we overcome +that resistance we have to do the hard + + align:start position:0% +that resistance we have to do the hard + + + align:start position:0% +that resistance we have to do the hard +work of persuading investors that it's + + align:start position:0% +work of persuading investors that it's + + + align:start position:0% +work of persuading investors that it's +not a choice between lower profits but a + + align:start position:0% +not a choice between lower profits but a + + + align:start position:0% +not a choice between lower profits but a +better workforce right versus higher + + align:start position:0% +better workforce right versus higher + + + align:start position:0% +better workforce right versus higher +profits and cheaper workforce instead + + align:start position:0% +profits and cheaper workforce instead + + + align:start position:0% +profits and cheaper workforce instead +the choice is for equally viable + + align:start position:0% +the choice is for equally viable + + + align:start position:0% +the choice is for equally viable +businesses we get to choose the kind of + + align:start position:0% +businesses we get to choose the kind of + + + align:start position:0% +businesses we get to choose the kind of +organizations we built successful + + align:start position:0% +organizations we built successful + + + align:start position:0% +organizations we built successful +venture capitalists who have built + + align:start position:0% +venture capitalists who have built + + + align:start position:0% +venture capitalists who have built +successful companies they meaningfully + + align:start position:0% +successful companies they meaningfully + + + align:start position:0% +successful companies they meaningfully +talk about the great organizations + + align:start position:0% +talk about the great organizations + + + align:start position:0% +talk about the great organizations +they've built entrepreneurs are + + align:start position:0% +they've built entrepreneurs are + + + align:start position:0% +they've built entrepreneurs are +uncomfortable talking to investors about + + align:start position:0% +uncomfortable talking to investors about + + + align:start position:0% +uncomfortable talking to investors about +a workforce strategy they are concerned + + align:start position:0% +a workforce strategy they are concerned + + + align:start position:0% +a workforce strategy they are concerned +that investors will view this as excess + + align:start position:0% +that investors will view this as excess + + + align:start position:0% +that investors will view this as excess +as having too high a burn rate they + + align:start position:0% +as having too high a burn rate they + + + align:start position:0% +as having too high a burn rate they +don't have fully at their grasp the + + align:start position:0% +don't have fully at their grasp the + + + align:start position:0% +don't have fully at their grasp the +economics of it they can't really make + + align:start position:0% +economics of it they can't really make + + + align:start position:0% +economics of it they can't really make +the business case as well as they might + + align:start position:0% +the business case as well as they might + + + align:start position:0% +the business case as well as they might +like to as to why it is that building a + + align:start position:0% +like to as to why it is that building a + + + align:start position:0% +like to as to why it is that building a +strategy like this will end up achieving + + align:start position:0% +strategy like this will end up achieving + + + align:start position:0% +strategy like this will end up achieving +the numbers in the next 25 10 years + + align:start position:0% +the numbers in the next 25 10 years + + + align:start position:0% +the numbers in the next 25 10 years +there is a tendency to expect that at + + align:start position:0% +there is a tendency to expect that at + + + align:start position:0% +there is a tendency to expect that at +the startup phase the founders will + + align:start position:0% +the startup phase the founders will + + + align:start position:0% +the startup phase the founders will +certainly work for below market rates + + align:start position:0% +certainly work for below market rates + + + align:start position:0% +certainly work for below market rates +and that the people that are hired will + + align:start position:0% +and that the people that are hired will + + + align:start position:0% +and that the people that are hired will +work for below market rates they'll work + + align:start position:0% +work for below market rates they'll work + + + align:start position:0% +work for below market rates they'll work +around the clock there should be no + + align:start position:0% +around the clock there should be no + + + align:start position:0% +around the clock there should be no +expectation of salary increases or + + align:start position:0% +expectation of salary increases or + + + align:start position:0% +expectation of salary increases or +benefits because the company hasn't + + align:start position:0% +benefits because the company hasn't + + + align:start position:0% +benefits because the company hasn't +started generating a profit now you're a + + align:start position:0% +started generating a profit now you're a + + + align:start position:0% +started generating a profit now you're a +scholar you know that the research tells + + align:start position:0% +scholar you know that the research tells + + + align:start position:0% +scholar you know that the research tells +us that if you build into the DNA of a + + align:start position:0% +us that if you build into the DNA of a + + + align:start position:0% +us that if you build into the DNA of a +company from the very start this kind of + + align:start position:0% +company from the very start this kind of + + + align:start position:0% +company from the very start this kind of +commitment this kind of strategy it'll + + align:start position:0% +commitment this kind of strategy it'll + + + align:start position:0% +commitment this kind of strategy it'll +be the driving framework for the company + + align:start position:0% +be the driving framework for the company + + + align:start position:0% +be the driving framework for the company +over time and so that's where all the + + align:start position:0% +over time and so that's where all the + + + align:start position:0% +over time and so that's where all the +evidence from other organizations plays + + align:start position:0% +evidence from other organizations plays + + + align:start position:0% +evidence from other organizations plays +in if you can help them to make that + + align:start position:0% +in if you can help them to make that + + + align:start position:0% +in if you can help them to make that +business case to understand the + + align:start position:0% +business case to understand the + + + align:start position:0% +business case to understand the +potential then there's some hope and so + + align:start position:0% +potential then there's some hope and so + + + align:start position:0% +potential then there's some hope and so +we have to find ways to deal with that + + align:start position:0% +we have to find ways to deal with that + + + align:start position:0% +we have to find ways to deal with that +could you give us an example of an + + align:start position:0% +could you give us an example of an + + + align:start position:0% +could you give us an example of an +organization or two that has really + + align:start position:0% +organization or two that has really + + + align:start position:0% +organization or two that has really +invested in this way take for example BP + + align:start position:0% +invested in this way take for example BP + + + align:start position:0% +invested in this way take for example BP +BP is an online car marketplace that's + + align:start position:0% +BP is an online car marketplace that's + + + align:start position:0% +BP is an online car marketplace that's +really kind of fixing the lemons problem + + align:start position:0% +really kind of fixing the lemons problem + + + align:start position:0% +really kind of fixing the lemons problem +for used cars basically right now you + + align:start position:0% +for used cars basically right now you + + + align:start position:0% +for used cars basically right now you +can think of the used-car industry is + + align:start position:0% +can think of the used-car industry is + + + align:start position:0% +can think of the used-car industry is +definitely not associated with a good + + align:start position:0% +definitely not associated with a good + + + align:start position:0% +definitely not associated with a good +job strategy not even a good service one + + align:start position:0% +job strategy not even a good service one + + + align:start position:0% +job strategy not even a good service one +of the key choices that alley resident + + align:start position:0% +of the key choices that alley resident + + + align:start position:0% +of the key choices that alley resident +one of the founders of this firm had to + + align:start position:0% +one of the founders of this firm had to + + + align:start position:0% +one of the founders of this firm had to +make was whether or not the technicians + + align:start position:0% +make was whether or not the technicians + + + align:start position:0% +make was whether or not the technicians +the people who'd be inspecting the cars + + align:start position:0% +the people who'd be inspecting the cars + + + align:start position:0% +the people who'd be inspecting the cars +was going to be hiring a series of + + align:start position:0% +was going to be hiring a series of + + + align:start position:0% +was going to be hiring a series of +contractor inspectors or whether or not + + align:start position:0% +contractor inspectors or whether or not + + + align:start position:0% +contractor inspectors or whether or not +he'd be investing in long-term employees + + align:start position:0% +he'd be investing in long-term employees + + + align:start position:0% +he'd be investing in long-term employees +he got different advice from different + + align:start position:0% +he got different advice from different + + + align:start position:0% +he got different advice from different +investors about that choice he + + align:start position:0% +investors about that choice he + + + align:start position:0% +investors about that choice he +ultimately decided that the strength and + + align:start position:0% +ultimately decided that the strength and + + + align:start position:0% +ultimately decided that the strength and +the quality and the innovations of his + + align:start position:0% +the quality and the innovations of his + + + align:start position:0% +the quality and the innovations of his +company could best be made by investing + + align:start position:0% +company could best be made by investing + + + align:start position:0% +company could best be made by investing +in employees they all those employees + + align:start position:0% +in employees they all those employees + + + align:start position:0% +in employees they all those employees +get extensive training they're upping + + align:start position:0% +get extensive training they're upping + + + align:start position:0% +get extensive training they're upping +their skill level they get some equity + + align:start position:0% +their skill level they get some equity + + + align:start position:0% +their skill level they get some equity +in the company and as that company has + + align:start position:0% +in the company and as that company has + + + align:start position:0% +in the company and as that company has +grown all of a sudden they are the + + align:start position:0% +grown all of a sudden they are the + + + align:start position:0% +grown all of a sudden they are the +single most visible and single most + + align:start position:0% +single most visible and single most + + + align:start position:0% +single most visible and single most +memorable and single best advocates for + + align:start position:0% +memorable and single best advocates for + + + align:start position:0% +memorable and single best advocates for +the company as it's scaled across the + + align:start position:0% +the company as it's scaled across the + + + align:start position:0% +the company as it's scaled across the +United States jessamine Rodriguez who is + + align:start position:0% +United States jessamine Rodriguez who is + + + align:start position:0% +United States jessamine Rodriguez who is +the founder of hot bread kitchen started + + align:start position:0% +the founder of hot bread kitchen started + + + align:start position:0% +the founder of hot bread kitchen started +with a long-term vision the idea was to + + align:start position:0% +with a long-term vision the idea was to + + + align:start position:0% +with a long-term vision the idea was to +enable primarily immigrant but other + + align:start position:0% +enable primarily immigrant but other + + + align:start position:0% +enable primarily immigrant but other +women and men who have an ethnic bread + + align:start position:0% +women and men who have an ethnic bread + + + align:start position:0% +women and men who have an ethnic bread +to take that to the market to create + + align:start position:0% +to take that to the market to create + + + align:start position:0% +to take that to the market to create +real economic opportunity through baking + + align:start position:0% +real economic opportunity through baking + + + align:start position:0% +real economic opportunity through baking +bread and to enable them to build their + + align:start position:0% +bread and to enable them to build their + + + align:start position:0% +bread and to enable them to build their +own businesses around their particular + + align:start position:0% +own businesses around their particular + + + align:start position:0% +own businesses around their particular +craft and so hot bread kitchen now very + + align:start position:0% +craft and so hot bread kitchen now very + + + align:start position:0% +craft and so hot bread kitchen now very +successful operation in Harlem is + + align:start position:0% +successful operation in Harlem is + + + align:start position:0% +successful operation in Harlem is +incubating bread businesses throughout + + align:start position:0% +incubating bread businesses throughout + + + align:start position:0% +incubating bread businesses throughout +New York and beyond so it's a bakery yes + + align:start position:0% +New York and beyond so it's a bakery yes + + + align:start position:0% +New York and beyond so it's a bakery yes +but it's far more than that and to help + + align:start position:0% +but it's far more than that and to help + + + align:start position:0% +but it's far more than that and to help +individuals to kind of build math skills + + align:start position:0% +individuals to kind of build math skills + + + align:start position:0% +individuals to kind of build math skills +while they're creating breads to build + + align:start position:0% +while they're creating breads to build + + + align:start position:0% +while they're creating breads to build +business skills while they're creating + + align:start position:0% +business skills while they're creating + + + align:start position:0% +business skills while they're creating +breads to build marketing + + align:start position:0% +breads to build marketing + + + align:start position:0% +breads to build marketing +skills while they're creating bread was + + align:start position:0% +skills while they're creating bread was + + + align:start position:0% +skills while they're creating bread was +a brilliant touch the bakery is a great + + align:start position:0% +a brilliant touch the bakery is a great + + + align:start position:0% +a brilliant touch the bakery is a great +example in one place I should clearly + + align:start position:0% +example in one place I should clearly + + + align:start position:0% +example in one place I should clearly +visit how about other examples recently + + align:start position:0% +visit how about other examples recently + + + align:start position:0% +visit how about other examples recently +we were supporting a sector of energy + + align:start position:0% +we were supporting a sector of energy + + + align:start position:0% +we were supporting a sector of energy +entrepreneurs looking to address issues + + align:start position:0% +entrepreneurs looking to address issues + + + align:start position:0% +entrepreneurs looking to address issues +of climate change and one company + + align:start position:0% +of climate change and one company + + + align:start position:0% +of climate change and one company +rebound is a remarkable refrigeration + + align:start position:0% +rebound is a remarkable refrigeration + + + align:start position:0% +rebound is a remarkable refrigeration +company that has the potential of saving + + align:start position:0% +company that has the potential of saving + + + align:start position:0% +company that has the potential of saving +supermarkets enormous amount of money in + + align:start position:0% +supermarkets enormous amount of money in + + + align:start position:0% +supermarkets enormous amount of money in +refrigeration costs and dramatically + + align:start position:0% +refrigeration costs and dramatically + + + align:start position:0% +refrigeration costs and dramatically +reducing the amount of co2 the founder + + align:start position:0% +reducing the amount of co2 the founder + + + align:start position:0% +reducing the amount of co2 the founder +of that company is eager to build a + + align:start position:0% +of that company is eager to build a + + + align:start position:0% +of that company is eager to build a +business that is focused on good people + + align:start position:0% +business that is focused on good people + + + align:start position:0% +business that is focused on good people +great jobs pathways of upward mobility + + align:start position:0% +great jobs pathways of upward mobility + + + align:start position:0% +great jobs pathways of upward mobility +it's who he is it's where he wants to + + align:start position:0% +it's who he is it's where he wants to + + + align:start position:0% +it's who he is it's where he wants to +take his company entrepreneurship can be + + align:start position:0% +take his company entrepreneurship can be + + + align:start position:0% +take his company entrepreneurship can be +used to provide good jobs how do we get + + align:start position:0% +used to provide good jobs how do we get + + + align:start position:0% +used to provide good jobs how do we get +this to become the norm people need to + + align:start position:0% +this to become the norm people need to + + + align:start position:0% +this to become the norm people need to +vote with their feet right as you when + + align:start position:0% +vote with their feet right as you when + + + align:start position:0% +vote with their feet right as you when +you think about joining a company when + + align:start position:0% +you think about joining a company when + + + align:start position:0% +you think about joining a company when +you think about as say you're in a big + + align:start position:0% +you think about as say you're in a big + + + align:start position:0% +you think about as say you're in a big +company thinking about which kind of + + align:start position:0% +company thinking about which kind of + + + align:start position:0% +company thinking about which kind of +companies to partner with when you think + + align:start position:0% +companies to partner with when you think + + + align:start position:0% +companies to partner with when you think +about I even as an investor make sure + + align:start position:0% +about I even as an investor make sure + + + align:start position:0% +about I even as an investor make sure +you're having that conversation and + + align:start position:0% +you're having that conversation and + + + align:start position:0% +you're having that conversation and +understanding as you're selecting among + + align:start position:0% +understanding as you're selecting among + + + align:start position:0% +understanding as you're selecting among +different groups to work with different + + align:start position:0% +different groups to work with different + + + align:start position:0% +different groups to work with different +firms to work with even different + + align:start position:0% +firms to work with even different + + + align:start position:0% +firms to work with even different +portfolio companies to invest in go one + + align:start position:0% +portfolio companies to invest in go one + + + align:start position:0% +portfolio companies to invest in go one +layer beyond the simple value creation + + align:start position:0% +layer beyond the simple value creation + + + align:start position:0% +layer beyond the simple value creation +value capture logic and get to the + + align:start position:0% +value capture logic and get to the + + + align:start position:0% +value capture logic and get to the +organization and the team you are more + + align:start position:0% +organization and the team you are more + + + align:start position:0% +organization and the team you are more +likely to be investing in a long-term + + align:start position:0% +likely to be investing in a long-term + + + align:start position:0% +likely to be investing in a long-term +play that really delivers fundamental + + align:start position:0% +play that really delivers fundamental + + + align:start position:0% +play that really delivers fundamental +value and really delivers strong returns + + align:start position:0% +value and really delivers strong returns + + + align:start position:0% +value and really delivers strong returns +if you're investing in the kind of + + align:start position:0% +if you're investing in the kind of + + + align:start position:0% +if you're investing in the kind of +company that people are going to be + + align:start position:0% +company that people are going to be + + + align:start position:0% +company that people are going to be +attracted to and allows people to + + align:start position:0% +attracted to and allows people to + + + align:start position:0% +attracted to and allows people to +nurture and grow well Scott I think this + + align:start position:0% +nurture and grow well Scott I think this + + + align:start position:0% +nurture and grow well Scott I think this +is an important message for + + align:start position:0% +is an important message for + + + align:start position:0% +is an important message for +entrepreneurs for investors and for + + align:start position:0% +entrepreneurs for investors and for + + + align:start position:0% +entrepreneurs for investors and for +young people who really do want to build + + align:start position:0% +young people who really do want to build + + + align:start position:0% +young people who really do want to build +great companies that address big + + align:start position:0% +great companies that address big + + + align:start position:0% +great companies that address big +problems in society that are successful + + align:start position:0% +problems in society that are successful + + + align:start position:0% +problems in society that are successful +and that provide good jobs and career + + align:start position:0% +and that provide good jobs and career + + + align:start position:0% +and that provide good jobs and career +opportunities to their peers so thank + + align:start position:0% +opportunities to their peers so thank + + + align:start position:0% +opportunities to their peers so thank +you very much thank you very much as + + align:start position:0% +you very much thank you very much as + + + align:start position:0% +you very much thank you very much as +well thank you so much thank you for + + align:start position:0% +well thank you so much thank you for + + + align:start position:0% +well thank you so much thank you for +your time today you're welcome + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/r2NMWEsNcTs.txt b/r2NMWEsNcTs.txt new file mode 100644 index 0000000000000000000000000000000000000000..4bf3f412bb784decb0c49dfca6f3cd2ff0da326e --- /dev/null +++ b/r2NMWEsNcTs.txt @@ -0,0 +1,11323 @@ +align:start position:0% + +The following content is provided under + + align:start position:0% +The following content is provided under + + + align:start position:0% +The following content is provided under +a Creative Common License. Your support + + align:start position:0% +a Creative Common License. Your support + + + align:start position:0% +a Creative Common License. Your support +will help MIT Open Courseware continue + + align:start position:0% +will help MIT Open Courseware continue + + + align:start position:0% +will help MIT Open Courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free. To make a donation + + align:start position:0% +resources for free. To make a donation + + + align:start position:0% +resources for free. To make a donation +or to view additional materials from + + align:start position:0% +or to view additional materials from + + + align:start position:0% +or to view additional materials from +hundreds of MIT courses, visit MIT Open + + align:start position:0% +hundreds of MIT courses, visit MIT Open + + + align:start position:0% +hundreds of MIT courses, visit MIT Open +Courseware at + + align:start position:0% + + + + align:start position:0% + +ocw.mmit.edu. about a theorem that + + align:start position:0% +ocw.mmit.edu. about a theorem that + + + align:start position:0% +ocw.mmit.edu. about a theorem that +was quite powerful and applied to + + align:start position:0% +was quite powerful and applied to + + + align:start position:0% +was quite powerful and applied to +complex vector + + align:start position:0% +complex vector + + + align:start position:0% +complex vector +spaces for all V belonging to + + align:start position:0% +spaces for all V belonging to + + + align:start position:0% +spaces for all V belonging to +V + + align:start position:0% +V + + + align:start position:0% +V +complex vector space. + + align:start position:0% +complex vector space. + + + align:start position:0% +complex vector space. +This implied that the operator was + + align:start position:0% +This implied that the operator was + + + align:start position:0% +This implied that the operator was +zero and uh it's not true for real + + align:start position:0% +zero and uh it's not true for real + + + align:start position:0% +zero and uh it's not true for real +vector + + align:start position:0% +vector + + + align:start position:0% +vector +spaces and uh we gave a proof that made + + align:start position:0% +spaces and uh we gave a proof that made + + + align:start position:0% +spaces and uh we gave a proof that made +it clear that indeed u proof wouldn't + + align:start position:0% +it clear that indeed u proof wouldn't + + + align:start position:0% +it clear that indeed u proof wouldn't +work for a real vector space. I will ask + + align:start position:0% +work for a real vector space. I will ask + + + align:start position:0% +work for a real vector space. I will ask +you in the homework to do something that + + align:start position:0% +you in the homework to do something that + + + align:start position:0% +you in the homework to do something that +uh presumably would be the first thing + + align:start position:0% +uh presumably would be the first thing + + + align:start position:0% +uh presumably would be the first thing +you would do if you had to try to + + align:start position:0% +you would do if you had to try to + + + align:start position:0% +you would do if you had to try to +understand why this is true. take 2x two + + align:start position:0% +understand why this is true. take 2x two + + + align:start position:0% +understand why this is true. take 2x two +matrices and just see why it has to be + + align:start position:0% +matrices and just see why it has to be + + + align:start position:0% +matrices and just see why it has to be +zero in one case and it doesn't have to + + align:start position:0% +zero in one case and it doesn't have to + + + align:start position:0% +zero in one case and it doesn't have to +be zero in the other case and uh I think + + align:start position:0% +be zero in the other case and uh I think + + + align:start position:0% +be zero in the other case and uh I think +that will give you a a better + + align:start position:0% +that will give you a a better + + + align:start position:0% +that will give you a a better +perspective on why this happens and u + + align:start position:0% +perspective on why this happens and u + + + align:start position:0% +perspective on why this happens and u +then once you do it for 2x two and you + + align:start position:0% +then once you do it for 2x two and you + + + align:start position:0% +then once you do it for 2x two and you +see how it works you can do it for n byn + + align:start position:0% +see how it works you can do it for n byn + + + align:start position:0% +see how it works you can do it for n byn +um matrices and it will be clear as well + + align:start position:0% +um matrices and it will be clear as well + + + align:start position:0% +um matrices and it will be clear as well +so we'll use this theorem our immediate + + align:start position:0% +so we'll use this theorem our immediate + + + align:start position:0% +so we'll use this theorem our immediate +application + + align:start position:0% +application + + + align:start position:0% +application +of this theorem + + align:start position:0% +of this theorem + + + align:start position:0% +of this theorem +was + + align:start position:0% + + + + align:start position:0% + +application. a well-known result that uh + + align:start position:0% +application. a well-known result that uh + + + align:start position:0% +application. a well-known result that uh +you could prove now rigorously that t is + + align:start position:0% +you could prove now rigorously that t is + + + align:start position:0% +you could prove now rigorously that t is +equal to t + + align:start position:0% +equal to t + + + align:start position:0% +equal to t +dagger which is to say the operator is + + align:start position:0% +dagger which is to say the operator is + + + align:start position:0% +dagger which is to say the operator is +equal to the adjint and I still I think + + align:start position:0% +equal to the adjint and I still I think + + + align:start position:0% +equal to the adjint and I still I think +I will call this and in the notes you + + align:start position:0% +I will call this and in the notes you + + + align:start position:0% +I will call this and in the notes you +will see always the adjint as opposed to + + align:start position:0% +will see always the adjint as opposed to + + + align:start position:0% +will see always the adjint as opposed to +her mission conjugate and I will say + + align:start position:0% +her mission conjugate and I will say + + + align:start position:0% +her mission conjugate and I will say +whenever the operator is equal to the + + align:start position:0% +whenever the operator is equal to the + + + align:start position:0% +whenever the operator is equal to the +adjint that it is + + align:start position:0% +adjint that it is + + + align:start position:0% +adjint that it is +hermission. So a hermission operator is + + align:start position:0% +hermission. So a hermission operator is + + + align:start position:0% +hermission. So a hermission operator is +equivalent to saying that V + + align:start position:0% +equivalent to saying that V + + + align:start position:0% +equivalent to saying that V +TV is a real number for all + + align:start position:0% +TV is a real number for all + + + align:start position:0% +TV is a real number for all +V. And we prove + + align:start position:0% + + + + align:start position:0% + +that in other words + + align:start position:0% +that in other words + + + align:start position:0% +that in other words +physically her mission operators have + + align:start position:0% +physically her mission operators have + + + align:start position:0% +physically her mission operators have +real expectation values. This is an + + align:start position:0% +real expectation values. This is an + + + align:start position:0% +real expectation values. This is an +expectation value because as as you + + align:start position:0% +expectation value because as as you + + + align:start position:0% +expectation value because as as you +remember in the bracket notation + + align:start position:0% +remember in the bracket notation + + + align:start position:0% +remember in the bracket notation +vtv you could write it v t v it's the + + align:start position:0% +vtv you could write it v t v it's the + + + align:start position:0% +vtv you could write it v t v it's the +same thing. So it is an expectation + + align:start position:0% +same thing. So it is an expectation + + + align:start position:0% +same thing. So it is an expectation +value. So it's an important thing + + align:start position:0% +value. So it's an important thing + + + align:start position:0% +value. So it's an important thing +because we usually deal with hermission + + align:start position:0% +because we usually deal with hermission + + + align:start position:0% +because we usually deal with hermission +operators and we want expectation values + + align:start position:0% +operators and we want expectation values + + + align:start position:0% +operators and we want expectation values +of hermission operators to be real. + + align:start position:0% +of hermission operators to be real. + + + align:start position:0% +of hermission operators to be real. +Now now that we're talking about + + align:start position:0% +Now now that we're talking about + + + align:start position:0% +Now now that we're talking about +hermission operators, I will delay a + + align:start position:0% +hermission operators, I will delay a + + + align:start position:0% +hermission operators, I will delay a +complete discussion of u diagonalization + + align:start position:0% +complete discussion of u diagonalization + + + align:start position:0% +complete discussion of u diagonalization +and diagonalization of several operators + + align:start position:0% +and diagonalization of several operators + + + align:start position:0% +and diagonalization of several operators +simultaneously for the next lecture. Um + + align:start position:0% +simultaneously for the next lecture. Um + + + align:start position:0% +simultaneously for the next lecture. Um +today I want to move forward a bit and + + align:start position:0% +today I want to move forward a bit and + + + align:start position:0% +today I want to move forward a bit and +do some other things and uh this way we + + align:start position:0% +do some other things and uh this way we + + + align:start position:0% +do some other things and uh this way we +spread out a little more the math and uh + + align:start position:0% +spread out a little more the math and uh + + + align:start position:0% +spread out a little more the math and uh +we can begin to look more at u physical + + align:start position:0% +we can begin to look more at u physical + + + align:start position:0% +we can begin to look more at u physical +issues and how they apply here. But at + + align:start position:0% +issues and how they apply here. But at + + + align:start position:0% +issues and how they apply here. But at +any rate, we're just here already and we + + align:start position:0% +any rate, we're just here already and we + + + align:start position:0% +any rate, we're just here already and we +can prove two basic things that uh are + + align:start position:0% +can prove two basic things that uh are + + + align:start position:0% +can prove two basic things that uh are +the kind of things + + align:start position:0% +the kind of things + + + align:start position:0% +the kind of things +that an 805 student should be able to + + align:start position:0% +that an 805 student should be able to + + + align:start position:0% +that an 805 student should be able to +prove at any time. They're really very + + align:start position:0% +prove at any time. They're really very + + + align:start position:0% +prove at any time. They're really very +simple and uh it's a kind of proof that + + align:start position:0% +simple and uh it's a kind of proof that + + + align:start position:0% +simple and uh it's a kind of proof that +is very short couple of lines something + + align:start position:0% +is very short couple of lines something + + + align:start position:0% +is very short couple of lines something +you should be able to reproduce at any + + align:start position:0% +you should be able to reproduce at any + + + align:start position:0% +you should be able to reproduce at any +time. So the first theorem says the igen + + align:start position:0% + + + + align:start position:0% + +values of hermission operators. + + align:start position:0% +values of hermission operators. + + + align:start position:0% +values of hermission operators. +H is for her mission are + + align:start position:0% + + + + align:start position:0% + +real and + + align:start position:0% +real and + + + align:start position:0% +real and +of I will do a little bit of a notation + + align:start position:0% +of I will do a little bit of a notation + + + align:start position:0% +of I will do a little bit of a notation +in which I will start with an + + align:start position:0% +in which I will start with an + + + align:start position:0% +in which I will start with an +expression and evaluate it sort of to + + align:start position:0% +expression and evaluate it sort of to + + + align:start position:0% +expression and evaluate it sort of to +the left and to the right. So when you + + align:start position:0% +the left and to the right. So when you + + + align:start position:0% +the left and to the right. So when you +have an equation you start here and you + + align:start position:0% +have an equation you start here and you + + + align:start position:0% +have an equation you start here and you +start evaluating there. So I will start + + align:start position:0% +start evaluating there. So I will start + + + align:start position:0% +start evaluating there. So I will start +with this. consider v + + align:start position:0% +with this. consider v + + + align:start position:0% +with this. consider v +TV and I will box it as being the origin + + align:start position:0% +TV and I will box it as being the origin + + + align:start position:0% +TV and I will box it as being the origin +and I will start evaluating it. Now if V + + align:start position:0% +and I will start evaluating it. Now if V + + + align:start position:0% +and I will start evaluating it. Now if V +is an igon vector. So let V be an igon + + align:start position:0% + + + + align:start position:0% + +vector on + + align:start position:0% +vector on + + + align:start position:0% +vector on +vector + + align:start position:0% +vector + + + align:start position:0% +vector +vector. So that um TV is equal to lambda + + align:start position:0% +vector. So that um TV is equal to lambda + + + align:start position:0% +vector. So that um TV is equal to lambda +V and now we say consider that + + align:start position:0% +V and now we say consider that + + + align:start position:0% +V and now we say consider that +expression in the + + align:start position:0% +expression in the + + + align:start position:0% +expression in the +box and you try to evaluate it. So one + + align:start position:0% +box and you try to evaluate it. So one + + + align:start position:0% +box and you try to evaluate it. So one +way to evaluate it, I evaluate to the + + align:start position:0% +way to evaluate it, I evaluate to the + + + align:start position:0% +way to evaluate it, I evaluate to the +left and then evaluate to the right is + + align:start position:0% +left and then evaluate to the right is + + + align:start position:0% +left and then evaluate to the right is +the naive evaluation. T on V is lambda + + align:start position:0% +the naive evaluation. T on V is lambda + + + align:start position:0% +the naive evaluation. T on V is lambda +V. So substitute it there. V lambda V. + + align:start position:0% +V. So substitute it there. V lambda V. + + + align:start position:0% +V. So substitute it there. V lambda V. +We know it. And then by homogenity this + + align:start position:0% +We know it. And then by homogenity this + + + align:start position:0% +We know it. And then by homogenity this +lambda goes out and therefore it's + + align:start position:0% +lambda goes out and therefore it's + + + align:start position:0% +lambda goes out and therefore it's +lambda + + align:start position:0% + + + + align:start position:0% + +VV. On the other + + align:start position:0% + + + + align:start position:0% + +hand, we have that we can go to the + + align:start position:0% +hand, we have that we can go to the + + + align:start position:0% +hand, we have that we can go to the +right. And what is the way you move an + + align:start position:0% +right. And what is the way you move an + + + align:start position:0% +right. And what is the way you move an +operator to the first position? By + + align:start position:0% +operator to the first position? By + + + align:start position:0% +operator to the first position? By +putting a dagger. That's a definition. + + align:start position:0% +putting a dagger. That's a definition. + + + align:start position:0% +putting a dagger. That's a definition. +So this is by + + align:start position:0% +So this is by + + + align:start position:0% +So this is by +definition. By + + align:start position:0% +definition. By + + + align:start position:0% +definition. By +definition. Now we use that the operator + + align:start position:0% +definition. Now we use that the operator + + + align:start position:0% +definition. Now we use that the operator +is hermission. So this is equal + + align:start position:0% +is hermission. So this is equal + + + align:start position:0% +is hermission. So this is equal +to t + + align:start position:0% +to t + + + align:start position:0% +to t +v and this is by t + + align:start position:0% +v and this is by t + + + align:start position:0% +v and this is by t +hermission. Then you can apply again the + + align:start position:0% +hermission. Then you can apply again the + + + align:start position:0% +hermission. Then you can apply again the +equation of the igon value. So this is + + align:start position:0% +equation of the igon value. So this is + + + align:start position:0% +equation of the igon value. So this is +lambda + + align:start position:0% + + + + align:start position:0% + +v and by conjugate homogeneity of the + + align:start position:0% +v and by conjugate homogeneity of the + + + align:start position:0% +v and by conjugate homogeneity of the +first input this is lambda + + align:start position:0% +first input this is lambda + + + align:start position:0% +first input this is lambda +star + + align:start position:0% + + + + align:start position:0% + +vv. So at the end of the day you have + + align:start position:0% +vv. So at the end of the day you have + + + align:start position:0% +vv. So at the end of the day you have +something on the extreme left something + + align:start position:0% +something on the extreme left something + + + align:start position:0% +something on the extreme left something +on the extreme right. + + align:start position:0% + + + + align:start position:0% + +V if it's if there is an igon vector V + + align:start position:0% +V if it's if there is an igon vector V + + + align:start position:0% +V if it's if there is an igon vector V +can be assumed to be non zero. Um the + + align:start position:0% +can be assumed to be non zero. Um the + + + align:start position:0% +can be assumed to be non zero. Um the +way we are saying things in a sense zero + + align:start position:0% +way we are saying things in a sense zero + + + align:start position:0% +way we are saying things in a sense zero +we also think of it as an igon vector + + align:start position:0% +we also think of it as an igon vector + + + align:start position:0% +we also think of it as an igon vector +but it's a trivial one but uh the fact + + align:start position:0% +but it's a trivial one but uh the fact + + + align:start position:0% +but it's a trivial one but uh the fact +that there's an igon value means there's + + align:start position:0% +that there's an igon value means there's + + + align:start position:0% +that there's an igon value means there's +a nonzero v that solves this equation. + + align:start position:0% +a nonzero v that solves this equation. + + + align:start position:0% +a nonzero v that solves this equation. +So we're using that nonzero v and + + align:start position:0% +So we're using that nonzero v and + + + align:start position:0% +So we're using that nonzero v and +therefore this is a + + align:start position:0% +therefore this is a + + + align:start position:0% +therefore this is a +number that is non zero. You + + align:start position:0% +number that is non zero. You + + + align:start position:0% +number that is non zero. You +bring one to the other side and you have + + align:start position:0% +bring one to the other side and you have + + + align:start position:0% +bring one to the other side and you have +lambda minus lambda star time + + align:start position:0% +lambda minus lambda star time + + + align:start position:0% +lambda minus lambda star time +v equals zero. This is different from + + align:start position:0% + + + + align:start position:0% + +zero. This is different from zero and + + align:start position:0% +zero. This is different from zero and + + + align:start position:0% +zero. This is different from zero and +therefore lambda is equal to lambda + + align:start position:0% + + + + align:start position:0% + +star. So it's a classic proof + + align:start position:0% +star. So it's a classic proof + + + align:start position:0% +star. So it's a classic proof +of relatively straightforward. + + align:start position:0% +of relatively straightforward. + + + align:start position:0% +of relatively straightforward. +The second theorem is as simple to prove + + align:start position:0% +The second theorem is as simple to prove + + + align:start position:0% +The second theorem is as simple to prove +and um it's already interesting and it + + align:start position:0% +and um it's already interesting and it + + + align:start position:0% +and um it's already interesting and it +states that different vectors of a + + align:start position:0% +states that different vectors of a + + + align:start position:0% +states that different vectors of a +hermission operator + + align:start position:0% +hermission operator + + + align:start position:0% +hermission operator +um well different values of hermission + + align:start position:0% +um well different values of hermission + + + align:start position:0% +um well different values of hermission +operators correspond to orthogonal + + align:start position:0% +operators correspond to orthogonal + + + align:start position:0% +operators correspond to orthogonal +functions or vectors. So + + align:start position:0% + + + + align:start position:0% + +different + + align:start position:0% + + + + align:start position:0% + +values of hermission + + align:start position:0% +values of hermission + + + align:start position:0% +values of hermission +ops + + align:start position:0% + + + + align:start position:0% + +correspond to + + align:start position:0% + + + + align:start position:0% + +orthogonal functions on vectors I'm + + align:start position:0% + + + + align:start position:0% + +sorry. So what are we saying here? We're + + align:start position:0% +sorry. So what are we saying here? We're + + + align:start position:0% +sorry. So what are we saying here? We're +saying that suppose you have a v1 that + + align:start position:0% +saying that suppose you have a v1 that + + + align:start position:0% +saying that suppose you have a v1 that +acted on t gives you a lambda 1 v1. It's + + align:start position:0% +acted on t gives you a lambda 1 v1. It's + + + align:start position:0% +acted on t gives you a lambda 1 v1. It's +one value. You have another one v2 is + + align:start position:0% +one value. You have another one v2 is + + + align:start position:0% +one value. You have another one v2 is +equal to lambda 2 v2 and lambda 1 is + + align:start position:0% +equal to lambda 2 v2 and lambda 1 is + + + align:start position:0% +equal to lambda 2 v2 and lambda 1 is +different from lambda 2. + + align:start position:0% + + + + align:start position:0% + +Now just focusing on a fact that is + + align:start position:0% +Now just focusing on a fact that is + + + align:start position:0% +Now just focusing on a fact that is +going to show up later and it's going to + + align:start position:0% +going to show up later and it's going to + + + align:start position:0% +going to show up later and it's going to +cause uh make life interesting is that + + align:start position:0% +cause uh make life interesting is that + + + align:start position:0% +cause uh make life interesting is that +some values may have a multiplicity of + + align:start position:0% +some values may have a multiplicity of + + + align:start position:0% +some values may have a multiplicity of +igon vectors. + + align:start position:0% +igon vectors. + + + align:start position:0% +igon vectors. +In other words, it's not, you know, if a + + align:start position:0% +In other words, it's not, you know, if a + + + align:start position:0% +In other words, it's not, you know, if a +vector V is an igon vector, minus V is + + align:start position:0% +vector V is an igon vector, minus V is + + + align:start position:0% +vector V is an igon vector, minus V is +an igon vector. Square root of 3 V is an + + align:start position:0% +an igon vector. Square root of 3 V is an + + + align:start position:0% +an igon vector. Square root of 3 V is an +igon vector, but that's a onedimensional + + align:start position:0% +igon vector, but that's a onedimensional + + + align:start position:0% +igon vector, but that's a onedimensional +subspace. But sometimes for a given + + align:start position:0% +subspace. But sometimes for a given + + + align:start position:0% +subspace. But sometimes for a given +value, there might be a higher + + align:start position:0% +value, there might be a higher + + + align:start position:0% +value, there might be a higher +dimensional subspace of vectors. That's + + align:start position:0% +dimensional subspace of vectors. That's + + + align:start position:0% +dimensional subspace of vectors. That's +a problem of + + align:start position:0% +a problem of + + + align:start position:0% +a problem of +degeneracy and it's very interesting. + + align:start position:0% +degeneracy and it's very interesting. + + + align:start position:0% +degeneracy and it's very interesting. +Makes life really interesting in quantum + + align:start position:0% +Makes life really interesting in quantum + + + align:start position:0% +Makes life really interesting in quantum +mechanics. So if you have degeneracy in + + align:start position:0% +mechanics. So if you have degeneracy in + + + align:start position:0% +mechanics. So if you have degeneracy in +that set of iggon vectors form a + + align:start position:0% +that set of iggon vectors form a + + + align:start position:0% +that set of iggon vectors form a +subspace and you can choose a basis and + + align:start position:0% +subspace and you can choose a basis and + + + align:start position:0% +subspace and you can choose a basis and +you could have several vectors here. Now + + align:start position:0% +you could have several vectors here. Now + + + align:start position:0% +you could have several vectors here. Now +what do you do in that case? The theorem + + align:start position:0% +what do you do in that case? The theorem + + + align:start position:0% +what do you do in that case? The theorem +doesn't say much. So it means choose + + align:start position:0% +doesn't say much. So it means choose + + + align:start position:0% +doesn't say much. So it means choose +anyone. If you had a basis there choose + + align:start position:0% +anyone. If you had a basis there choose + + + align:start position:0% +anyone. If you had a basis there choose +anyone. The fact remains that if these + + align:start position:0% +anyone. The fact remains that if these + + + align:start position:0% +anyone. The fact remains that if these +two igon values are different then you + + align:start position:0% +two igon values are different then you + + + align:start position:0% +two igon values are different then you +will be able to show that the igon + + align:start position:0% +will be able to show that the igon + + + align:start position:0% +will be able to show that the igon +vectors are + + align:start position:0% +vectors are + + + align:start position:0% +vectors are +orthogonal. So if you have some space of + + align:start position:0% +orthogonal. So if you have some space of + + + align:start position:0% +orthogonal. So if you have some space of +vectors a degenerate higher dimensional + + align:start position:0% +vectors a degenerate higher dimensional + + + align:start position:0% +vectors a degenerate higher dimensional +space of igon vectors one value and + + align:start position:0% +space of igon vectors one value and + + + align:start position:0% +space of igon vectors one value and +another space with another value any + + align:start position:0% +another space with another value any + + + align:start position:0% +another space with another value any +vector here is orthogonal to any vector + + align:start position:0% +vector here is orthogonal to any vector + + + align:start position:0% +vector here is orthogonal to any vector +there. So how do you show + + align:start position:0% +there. So how do you show + + + align:start position:0% +there. So how do you show +this? How do you show this property? + + align:start position:0% +this? How do you show this property? + + + align:start position:0% +this? How do you show this property? +Well, + + align:start position:0% +Well, + + + align:start position:0% +Well, +uh you have to involve V_sub_1 and V2. + + align:start position:0% +uh you have to involve V_sub_1 and V2. + + + align:start position:0% +uh you have to involve V_sub_1 and V2. +So you're never going to be using the + + align:start position:0% +So you're never going to be using the + + + align:start position:0% +So you're never going to be using the +property that T is her mission unless + + align:start position:0% +property that T is her mission unless + + + align:start position:0% +property that T is her mission unless +you have an inner product. So if you + + align:start position:0% +you have an inner product. So if you + + + align:start position:0% +you have an inner product. So if you +didn't have any idea how to prove that + + align:start position:0% +didn't have any idea how to prove that + + + align:start position:0% +didn't have any idea how to prove that +you + + align:start position:0% +you + + + align:start position:0% +you +presumably at some stage realize that + + align:start position:0% +presumably at some stage realize that + + + align:start position:0% +presumably at some stage realize that +you probably have to use an inner + + align:start position:0% +you probably have to use an inner + + + align:start position:0% +you probably have to use an inner +product and we should mix the vector. So + + align:start position:0% +product and we should mix the vector. So + + + align:start position:0% +product and we should mix the vector. So +maybe a V2 inner product with this. So + + align:start position:0% +maybe a V2 inner product with this. So + + + align:start position:0% +maybe a V2 inner product with this. So +we'll take a + + align:start position:0% +we'll take a + + + align:start position:0% +we'll take a +V2 inner product with + + align:start position:0% + + + + align:start position:0% + +TV1. And this is interesting because uh + + align:start position:0% +TV1. And this is interesting because uh + + + align:start position:0% +TV1. And this is interesting because uh +we can use the that TV1 is lambda 1 v1 + + align:start position:0% +we can use the that TV1 is lambda 1 v1 + + + align:start position:0% +we can use the that TV1 is lambda 1 v1 +to show that this is just lambda + + align:start position:0% +to show that this is just lambda + + + align:start position:0% +to show that this is just lambda +1 v2 + + align:start position:0% + + + + align:start position:0% + +v1 and that already brings all kinds of + + align:start position:0% +v1 and that already brings all kinds of + + + align:start position:0% +v1 and that already brings all kinds of +good things. You're interested in this + + align:start position:0% +good things. You're interested in this + + + align:start position:0% +good things. You're interested in this +inner product. You want to show it zero + + align:start position:0% +inner product. You want to show it zero + + + align:start position:0% +inner product. You want to show it zero +so it shows up. So it's a good idea. So + + align:start position:0% +so it shows up. So it's a good idea. So + + + align:start position:0% +so it shows up. So it's a good idea. So +we've evaluated this and now you have to + + align:start position:0% +we've evaluated this and now you have to + + + align:start position:0% +we've evaluated this and now you have to +think of evaluating it in a different + + align:start position:0% +think of evaluating it in a different + + + align:start position:0% +think of evaluating it in a different +way. Again the operator is her mission. + + align:start position:0% +way. Again the operator is her mission. + + + align:start position:0% +way. Again the operator is her mission. +So it's asking you to move it to the + + align:start position:0% +So it's asking you to move it to the + + + align:start position:0% +So it's asking you to move it to the +other side and exploit that. So we'll + + align:start position:0% +other side and exploit that. So we'll + + + align:start position:0% +other side and exploit that. So we'll +move it to the other side a little + + align:start position:0% +move it to the other side a little + + + align:start position:0% +move it to the other side a little +quicker this time. Goes as t dagger but + + align:start position:0% +quicker this time. Goes as t dagger but + + + align:start position:0% +quicker this time. Goes as t dagger but +t dagger is equal to t because it's her + + align:start position:0% +t dagger is equal to t because it's her + + + align:start position:0% +t dagger is equal to t because it's her +mission. So this is equal to so this is + + align:start position:0% +mission. So this is equal to so this is + + + align:start position:0% +mission. So this is equal to so this is +the center of the equation. We go one + + align:start position:0% +the center of the equation. We go one + + + align:start position:0% +the center of the equation. We go one +way we go the other way. this time down. + + align:start position:0% +way we go the other way. this time down. + + + align:start position:0% +way we go the other way. this time down. +So we'll put t + + align:start position:0% +So we'll put t + + + align:start position:0% +So we'll put t +v2 + + align:start position:0% +v2 + + + align:start position:0% +v2 +v1 and this is equal to + + align:start position:0% +v1 and this is equal to + + + align:start position:0% +v1 and this is equal to +lambda let let me go a little slow here. + + align:start position:0% +lambda let let me go a little slow here. + + + align:start position:0% +lambda let let me go a little slow here. +uh lambda 2 v2 v1. Uh your impulse + + align:start position:0% +uh lambda 2 v2 v1. Uh your impulse + + + align:start position:0% +uh lambda 2 v2 v1. Uh your impulse +should be oh it goes out as lambda 2 + + align:start position:0% +should be oh it goes out as lambda 2 + + + align:start position:0% +should be oh it goes out as lambda 2 +star but the igon values are already + + align:start position:0% +star but the igon values are already + + + align:start position:0% +star but the igon values are already +real. So it goes out as lambda + + align:start position:0% +real. So it goes out as lambda + + + align:start position:0% +real. So it goes out as lambda +2 v2 + + align:start position:0% + + + + align:start position:0% + +v1 because the operator is hermission. + + align:start position:0% +v1 because the operator is hermission. + + + align:start position:0% +v1 because the operator is hermission. +So at this moment you have these two + + align:start position:0% +So at this moment you have these two + + + align:start position:0% +So at this moment you have these two +equations. You bring say this to the + + align:start position:0% +equations. You bring say this to the + + + align:start position:0% +equations. You bring say this to the +right hand side and you get lambda 1 + + align:start position:0% +right hand side and you get lambda 1 + + + align:start position:0% +right hand side and you get lambda 1 +minus lambda + + align:start position:0% +minus lambda + + + align:start position:0% +minus lambda +2 vub1 v2 is equal to + + align:start position:0% +2 vub1 v2 is equal to + + + align:start position:0% +2 vub1 v2 is equal to +zero. And since the igen values are + + align:start position:0% +zero. And since the igen values are + + + align:start position:0% +zero. And since the igen values are +supposed to be different you conclude + + align:start position:0% +supposed to be different you conclude + + + align:start position:0% +supposed to be different you conclude +that v1 inner product with v2 is + + align:start position:0% +that v1 inner product with v2 is + + + align:start position:0% +that v1 inner product with v2 is +zero. So that's the end of the proof. + + align:start position:0% + + + + align:start position:0% + +And + + align:start position:0% + + + + align:start position:0% + +uh and those are the two properties that + + align:start position:0% +uh and those are the two properties that + + + align:start position:0% +uh and those are the two properties that +are very + + align:start position:0% +are very + + + align:start position:0% +are very +quickly proven with rather little + + align:start position:0% +quickly proven with rather little + + + align:start position:0% +quickly proven with rather little +effort. + + align:start position:0% +effort. + + + align:start position:0% +effort. +So what do we go? Where do we go from + + align:start position:0% +So what do we go? Where do we go from + + + align:start position:0% +So what do we go? Where do we go from +now? Well, there's one more class of + + align:start position:0% +now? Well, there's one more class of + + + align:start position:0% +now? Well, there's one more class of +operators that are crucial in the + + align:start position:0% +operators that are crucial in the + + + align:start position:0% +operators that are crucial in the +physics. They're perhaps the as + + align:start position:0% +physics. They're perhaps the as + + + align:start position:0% +physics. They're perhaps the as +important as the hermission operators if + + align:start position:0% +important as the hermission operators if + + + align:start position:0% +important as the hermission operators if +not more. They are some operators that + + align:start position:0% +not more. They are some operators that + + + align:start position:0% +not more. They are some operators that +are called unitary + + align:start position:0% +are called unitary + + + align:start position:0% +are called unitary +operators. And the way I will introduce + + align:start position:0% +operators. And the way I will introduce + + + align:start position:0% +operators. And the way I will introduce +them is as follows. + + align:start position:0% +them is as follows. + + + align:start position:0% +them is as follows. +So I + + align:start position:0% + + + + align:start position:0% + +will say and it's an economical way to + + align:start position:0% +will say and it's an economical way to + + + align:start position:0% +will say and it's an economical way to +introduce them. So we'll talk about + + align:start position:0% +introduce them. So we'll talk about + + + align:start position:0% +introduce them. So we'll talk about +unitary operators. + + align:start position:0% + + + + align:start position:0% + +See if + + align:start position:0% + + + + align:start position:0% + +S is + + align:start position:0% + + + + align:start position:0% + +unitary and mathematicians call it an + + align:start position:0% +unitary and mathematicians call it an + + + align:start position:0% +unitary and mathematicians call it an +isometry. + + align:start position:0% + + + + align:start position:0% + +If you find that s acting on any + + align:start position:0% +If you find that s acting on any + + + align:start position:0% +If you find that s acting on any +vector, if you take the + + align:start position:0% +vector, if you take the + + + align:start position:0% +vector, if you take the +norm, it's equal to the norm of the + + align:start position:0% +norm, it's equal to the norm of the + + + align:start position:0% +norm, it's equal to the norm of the +vector for all + + align:start position:0% +vector for all + + + align:start position:0% +vector for all +u in the vector space. + + align:start position:0% + + + + align:start position:0% + +So let's follow + + align:start position:0% + + + + align:start position:0% + +this and uh make a couple of comments. + + align:start position:0% +this and uh make a couple of comments. + + + align:start position:0% +this and uh make a couple of comments. +An example, a trivial + + align:start position:0% +An example, a trivial + + + align:start position:0% +An example, a trivial +example. This operator lambda times the + + align:start position:0% + + + + align:start position:0% + +identity. Lambda times the identity acts + + align:start position:0% +identity. Lambda times the identity acts + + + align:start position:0% +identity. Lambda times the identity acts +on vectors. What does it do? Lambda + + align:start position:0% +on vectors. What does it do? Lambda + + + align:start position:0% +on vectors. What does it do? Lambda +times the identity. The identity does + + align:start position:0% +times the identity. The identity does + + + align:start position:0% +times the identity. The identity does +nothing on the vector. and lambda + + align:start position:0% +nothing on the vector. and lambda + + + align:start position:0% +nothing on the vector. and lambda +stretches + + align:start position:0% +stretches + + + align:start position:0% +stretches +it. So lambda in order not to change the + + align:start position:0% +it. So lambda in order not to change the + + + align:start position:0% +it. So lambda in order not to change the +length of an iggon ve of any vector + + align:start position:0% +length of an iggon ve of any vector + + + align:start position:0% +length of an iggon ve of any vector +should be kind of one. Well, in fact, + + align:start position:0% +should be kind of one. Well, in fact, + + + align:start position:0% +should be kind of one. Well, in fact, +this + + align:start position:0% +this + + + align:start position:0% +this +suffices is + + align:start position:0% + + + + align:start position:0% + +unitary if the absolute value of lambda + + align:start position:0% +unitary if the absolute value of lambda + + + align:start position:0% +unitary if the absolute value of lambda +is equal to + + align:start position:0% +is equal to + + + align:start position:0% +is equal to +one because then lambda is a phase and + + align:start position:0% +one because then lambda is a phase and + + + align:start position:0% +one because then lambda is a phase and +it just rotates the vector. Or in other + + align:start position:0% +it just rotates the vector. Or in other + + + align:start position:0% +it just rotates the vector. Or in other +words, you know that the norm of + + align:start position:0% +words, you know that the norm of + + + align:start position:0% +words, you know that the norm of +AV is equal to the absolute value of A + + align:start position:0% +AV is equal to the absolute value of A + + + align:start position:0% +AV is equal to the absolute value of A +times the norm of V where this is a + + align:start position:0% + + + + align:start position:0% + +number. And remember these two norms are + + align:start position:0% +number. And remember these two norms are + + + align:start position:0% +number. And remember these two norms are +different. This is the norm of a vector. + + align:start position:0% +different. This is the norm of a vector. + + + align:start position:0% +different. This is the norm of a vector. +This is the norm of a complex number. + + align:start position:0% +This is the norm of a complex number. + + + align:start position:0% +This is the norm of a complex number. +And therefore if you take lambda + + align:start position:0% +And therefore if you take lambda + + + align:start position:0% +And therefore if you take lambda +I lambda I u norm is lambda u is equal + + align:start position:0% +I lambda I u norm is lambda u is equal + + + align:start position:0% +I lambda I u norm is lambda u is equal +absolute value of lambda u and absolute + + align:start position:0% +absolute value of lambda u and absolute + + + align:start position:0% +absolute value of lambda u and absolute +value of lambda is equal to one is the + + align:start position:0% +value of lambda is equal to one is the + + + align:start position:0% +value of lambda is equal to one is the +answer. So + + align:start position:0% +answer. So + + + align:start position:0% +answer. So +that's a simple unitary operator but a + + align:start position:0% +that's a simple unitary operator but a + + + align:start position:0% +that's a simple unitary operator but a +important one. Another observation + + align:start position:0% +important one. Another observation + + + align:start position:0% +important one. Another observation +um what are the vectors annihilated by + + align:start position:0% +um what are the vectors annihilated by + + + align:start position:0% +um what are the vectors annihilated by +this operator u + + align:start position:0% + + + + align:start position:0% + +zero is the only vector because any + + align:start position:0% +zero is the only vector because any + + + align:start position:0% +zero is the only vector because any +other vector is non zero has some length + + align:start position:0% +other vector is non zero has some length + + + align:start position:0% +other vector is non zero has some length +so it's not killed so it kills only zero + + align:start position:0% +so it's not killed so it kills only zero + + + align:start position:0% +so it's not killed so it kills only zero +so um the + + align:start position:0% +so um the + + + align:start position:0% +so um the +null space of S is equal to zero + + align:start position:0% +null space of S is equal to zero + + + align:start position:0% +null space of S is equal to zero +vector. So this + + align:start position:0% +vector. So this + + + align:start position:0% +vector. So this +operator has no kernel. Nothing + + align:start position:0% +operator has no kernel. Nothing + + + align:start position:0% +operator has no kernel. Nothing +non-trivial is put to zero. It's an + + align:start position:0% +non-trivial is put to zero. It's an + + + align:start position:0% +non-trivial is put to zero. It's an +invertible + + align:start position:0% +invertible + + + align:start position:0% +invertible +operator. So s is + + align:start position:0% + + + + align:start position:0% + +invertible. + + align:start position:0% + + + + align:start position:0% + +Vertible. So that's a few things that + + align:start position:0% +Vertible. So that's a few things that + + + align:start position:0% +Vertible. So that's a few things that +you get very cheaply. Now from this + + align:start position:0% +you get very cheaply. Now from this + + + align:start position:0% +you get very cheaply. Now from this +equation s u= u. If you square that + + align:start position:0% +equation s u= u. If you square that + + + align:start position:0% +equation s u= u. If you square that +equation you would + + align:start position:0% +equation you would + + + align:start position:0% +equation you would +have s + + align:start position:0% +have s + + + align:start position:0% +have s +u s + + align:start position:0% +u s + + + align:start position:0% +u s +u is equal to u u. Maybe I should call + + align:start position:0% +u is equal to u u. Maybe I should call + + + align:start position:0% +u is equal to u u. Maybe I should call +it v. I don't know why I call it u but + + align:start position:0% +it v. I don't know why I call it u but + + + align:start position:0% +it v. I don't know why I call it u but +let's stick to you. + + align:start position:0% +let's stick to you. + + + align:start position:0% +let's stick to you. +Now remember that we can move operators + + align:start position:0% +Now remember that we can move operators + + + align:start position:0% +Now remember that we can move operators +from one side to the other. So I'll move + + align:start position:0% +from one side to the other. So I'll move + + + align:start position:0% +from one side to the other. So I'll move +this one to that side. If you move an S + + align:start position:0% +this one to that side. If you move an S + + + align:start position:0% +this one to that side. If you move an S +here, you would put an S dagger. But + + align:start position:0% +here, you would put an S dagger. But + + + align:start position:0% +here, you would put an S dagger. But +since the dagger of + + align:start position:0% +since the dagger of + + + align:start position:0% +since the dagger of +uh of an S dagger is S, you can move + + align:start position:0% +uh of an S dagger is S, you can move + + + align:start position:0% +uh of an S dagger is S, you can move +also the S to that side as an S dagger. + + align:start position:0% +also the S to that side as an S dagger. + + + align:start position:0% +also the S to that side as an S dagger. +So U S + + align:start position:0% +So U S + + + align:start position:0% +So U S +dagger S U. You see that if you want to + + align:start position:0% +dagger S U. You see that if you want to + + + align:start position:0% +dagger S U. You see that if you want to +move this one, you can move it by + + align:start position:0% +move this one, you can move it by + + + align:start position:0% +move this one, you can move it by +putting another dagger and you get that + + align:start position:0% +putting another dagger and you get that + + + align:start position:0% +putting another dagger and you get that +one. And this is u + + align:start position:0% +one. And this is u + + + align:start position:0% +one. And this is u +u and therefore you get + + align:start position:0% +u and therefore you get + + + align:start position:0% +u and therefore you get +u s + + align:start position:0% +u s + + + align:start position:0% +u s +dagger s minus the identity acting on u + + align:start position:0% +dagger s minus the identity acting on u + + + align:start position:0% +dagger s minus the identity acting on u +is equal to zero for all + + align:start position:0% + + + + align:start position:0% + +u. So for every vector this is true + + align:start position:0% +u. So for every vector this is true + + + align:start position:0% +u. So for every vector this is true +because this is true. We just squared + + align:start position:0% +because this is true. We just squared + + + align:start position:0% +because this is true. We just squared +it. And now you have our favorite + + align:start position:0% +it. And now you have our favorite + + + align:start position:0% +it. And now you have our favorite +theorem that says if this is true in a + + align:start position:0% +theorem that says if this is true in a + + + align:start position:0% +theorem that says if this is true in a +complex vector space this is zero. And + + align:start position:0% +complex vector space this is zero. And + + + align:start position:0% +complex vector space this is zero. And +therefore you've shown that s dagger s + + align:start position:0% +therefore you've shown that s dagger s + + + align:start position:0% +therefore you've shown that s dagger s +is equal to + + align:start position:0% + + + + align:start position:0% + +one. So that's another property of uh + + align:start position:0% +one. So that's another property of uh + + + align:start position:0% +one. So that's another property of uh +unitary operators. In fact that's the + + align:start position:0% +unitary operators. In fact that's the + + + align:start position:0% +unitary operators. In fact that's the +way it's many times defined. Unitary + + align:start position:0% +way it's many times defined. Unitary + + + align:start position:0% +way it's many times defined. Unitary +operators sometimes are said to be + + align:start position:0% +operators sometimes are said to be + + + align:start position:0% +operators sometimes are said to be +operators whose inverse is s + + align:start position:0% +operators whose inverse is s + + + align:start position:0% +operators whose inverse is s +dagger. I will not go into the + + align:start position:0% +dagger. I will not go into the + + + align:start position:0% +dagger. I will not go into the +subtleties of + + align:start position:0% +subtleties of + + + align:start position:0% +subtleties of +whether what steps in all these things + + align:start position:0% +whether what steps in all these things + + + align:start position:0% +whether what steps in all these things +I'm saying are true or not true for + + align:start position:0% +I'm saying are true or not true for + + + align:start position:0% +I'm saying are true or not true for +infinite dimensional operators um + + align:start position:0% +infinite dimensional operators um + + + align:start position:0% +infinite dimensional operators um +infinite dimensional vector spaces. So I + + align:start position:0% +infinite dimensional vector spaces. So I + + + align:start position:0% +infinite dimensional vector spaces. So I +will assume and it will be true in our + + align:start position:0% +will assume and it will be true in our + + + align:start position:0% +will assume and it will be true in our +examples that if s dagger is an inverse + + align:start position:0% +examples that if s dagger is an inverse + + + align:start position:0% +examples that if s dagger is an inverse +from the left it's also an inverse from + + align:start position:0% +from the left it's also an inverse from + + + align:start position:0% +from the left it's also an inverse from +the right and perhaps um everything is + + align:start position:0% +the right and perhaps um everything is + + + align:start position:0% +the right and perhaps um everything is +true for infinite dimensional operator + + align:start position:0% +true for infinite dimensional operator + + + align:start position:0% +true for infinite dimensional operator +vector spaces but I'm not 100% + + align:start position:0% +vector spaces but I'm not 100% + + + align:start position:0% +vector spaces but I'm not 100% +positive. + + align:start position:0% +positive. + + + align:start position:0% +positive. +So s dagger is the + + align:start position:0% +So s dagger is the + + + align:start position:0% +So s dagger is the +inverse dagger is the + + align:start position:0% + + + + align:start position:0% + +inverse of s and + + align:start position:0% + + + + align:start position:0% + +u + + align:start position:0% +u + + + align:start position:0% +u +that's pretty important thing. So one + + align:start position:0% +that's pretty important thing. So one + + + align:start position:0% +that's pretty important thing. So one +last + + align:start position:0% + + + + align:start position:0% + +comment has to do unitary operators has + + align:start position:0% +comment has to do unitary operators has + + + align:start position:0% +comment has to do unitary operators has +to do with bases. So suppose you have an + + align:start position:0% +to do with bases. So suppose you have an + + + align:start position:0% +to do with bases. So suppose you have an +orthonormal + + align:start position:0% + + + + align:start position:0% + +basis E1 E up to E N. + + align:start position:0% + + + + align:start position:0% + +Now you can define another basis + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% +um + + + align:start position:0% +um +fi equal I'll I'll change to a letter u + + align:start position:0% +fi equal I'll I'll change to a letter u + + + align:start position:0% +fi equal I'll I'll change to a letter u +u + + align:start position:0% +u + + + align:start position:0% +u +ei where u is unitary so it's like the + + align:start position:0% +ei where u is unitary so it's like the + + + align:start position:0% +ei where u is unitary so it's like the +s in fact most books in physics call u + + align:start position:0% +s in fact most books in physics call u + + + align:start position:0% +s in fact most books in physics call u +for unitary So maybe I should have + + align:start position:0% +for unitary So maybe I should have + + + align:start position:0% +for unitary So maybe I should have +changed that letter there too as well. + + align:start position:0% +changed that letter there too as well. + + + align:start position:0% +changed that letter there too as well. +So suppose you change bases, you put + + align:start position:0% +So suppose you change bases, you put + + + align:start position:0% +So suppose you change bases, you put +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +um + + align:start position:0% +um + + + align:start position:0% +um +oh there was something else I wanted to + + align:start position:0% +oh there was something else I wanted to + + + align:start position:0% +oh there was something else I wanted to +say + + align:start position:0% +say + + + align:start position:0% +say +before. Thanks to this equation, + + align:start position:0% +before. Thanks to this equation, + + + align:start position:0% +before. Thanks to this equation, +consider now the following thing. S U SV + + align:start position:0% + + + + align:start position:0% + +S U SV. You can move this S for example + + align:start position:0% +S U SV. You can move this S for example + + + align:start position:0% +S U SV. You can move this S for example +to the other side is S dagger S U V and + + align:start position:0% +to the other side is S dagger S U V and + + + align:start position:0% +to the other side is S dagger S U V and +S dagger S is equal to one and it's + + align:start position:0% +S dagger S is equal to one and it's + + + align:start position:0% +S dagger S is equal to one and it's +UV. So this is a pretty nice property. + + align:start position:0% +UV. So this is a pretty nice property. + + + align:start position:0% +UV. So this is a pretty nice property. +We started from the fact that it + + align:start position:0% +We started from the fact that it + + + align:start position:0% +We started from the fact that it +preserved the norm of a single vector of + + align:start position:0% +preserved the norm of a single vector of + + + align:start position:0% +preserved the norm of a single vector of +all vectors and now you see that in fact + + align:start position:0% +all vectors and now you see that in fact + + + align:start position:0% +all vectors and now you see that in fact +it preserves the inner product. So if + + align:start position:0% +it preserves the inner product. So if + + + align:start position:0% +it preserves the inner product. So if +you have two vectors to compute their + + align:start position:0% +you have two vectors to compute their + + + align:start position:0% +you have two vectors to compute their +inner product compute them after action + + align:start position:0% +inner product compute them after action + + + align:start position:0% +inner product compute them after action +with u or before action with u and it + + align:start position:0% +with u or before action with u and it + + + align:start position:0% +with u or before action with u and it +doesn't make a difference. + + align:start position:0% +doesn't make a difference. + + + align:start position:0% +doesn't make a difference. +So suppose you define a second basis + + align:start position:0% +So suppose you define a second basis + + + align:start position:0% +So suppose you define a second basis +here. You have one orthonormal basis. + + align:start position:0% +here. You have one orthonormal basis. + + + align:start position:0% +here. You have one orthonormal basis. +You define basis vectors like this. Then + + align:start position:0% +You define basis vectors like this. Then + + + align:start position:0% +You define basis vectors like this. Then +the + + align:start position:0% +the + + + align:start position:0% +the +claim is that the f_sub_1 up to + + align:start position:0% +claim is that the f_sub_1 up to + + + align:start position:0% +claim is that the f_sub_1 up to +fn is + + align:start position:0% +fn is + + + align:start position:0% +fn is +orthonormal. And for + + align:start position:0% +orthonormal. And for + + + align:start position:0% +orthonormal. And for +that you simply do the following. Just + + align:start position:0% +that you simply do the following. Just + + + align:start position:0% +that you simply do the following. Just +check fi + + align:start position:0% +check fi + + + align:start position:0% +check fi +fj is equal to u + + align:start position:0% +fj is equal to u + + + align:start position:0% +fj is equal to u +ei u + + align:start position:0% +ei u + + + align:start position:0% +ei u +ej by this property you can delete both + + align:start position:0% +ej by this property you can delete both + + + align:start position:0% +ej by this property you can delete both +u's and therefore this is e i + + align:start position:0% +u's and therefore this is e i + + + align:start position:0% +u's and therefore this is e i +ej and that's delta j. So the new basis + + align:start position:0% +ej and that's delta j. So the new basis + + + align:start position:0% +ej and that's delta j. So the new basis +is + + align:start position:0% + + + + align:start position:0% + +orthonormal. If you play with these + + align:start position:0% +orthonormal. If you play with these + + + align:start position:0% +orthonormal. If you play with these +things, it's easy to get uh some extra + + align:start position:0% +things, it's easy to get uh some extra + + + align:start position:0% +things, it's easy to get uh some extra +curious fact + + align:start position:0% +curious fact + + + align:start position:0% +curious fact +here. Let's think of + + align:start position:0% +here. Let's think of + + + align:start position:0% +here. Let's think of +the matrix representation of um of the + + align:start position:0% +the matrix representation of um of the + + + align:start position:0% +the matrix representation of um of the +operator U. + + align:start position:0% + + + + align:start position:0% + +U well we know how these things are and + + align:start position:0% +U well we know how these things are and + + + align:start position:0% +U well we know how these things are and +let's think of this in the basis E basis + + align:start position:0% +let's think of this in the basis E basis + + + align:start position:0% +let's think of this in the basis E basis +so U + + align:start position:0% +so U + + + align:start position:0% +so U +KI is equal to E + + align:start position:0% + + + + align:start position:0% + +K U U E + + align:start position:0% + + + + align:start position:0% + +EI that's the definition of + + align:start position:0% +EI that's the definition of + + + align:start position:0% +EI that's the definition of +U in the basis + + align:start position:0% + + + + align:start position:0% + +E the matrix elements of + + align:start position:0% + + + + align:start position:0% + +U. You can try to figure out what is + + align:start position:0% +U. You can try to figure out what is + + + align:start position:0% +U. You can try to figure out what is +UKI in the F basis. How does the + + align:start position:0% +UKI in the F basis. How does the + + + align:start position:0% +UKI in the F basis. How does the +operator U look in the F + + align:start position:0% +operator U look in the F + + + align:start position:0% +operator U look in the F +basis? Well, let's just do it without + + align:start position:0% +basis? Well, let's just do it without + + + align:start position:0% +basis? Well, let's just do it without +thinking. Um so in the f basis I would + + align:start position:0% +thinking. Um so in the f basis I would + + + align:start position:0% +thinking. Um so in the f basis I would +put f k + + align:start position:0% +put f k + + + align:start position:0% +put f k +u + + align:start position:0% + + + + align:start position:0% + +fi. Well but f k is u e k. So I'll put u + + align:start position:0% +fi. Well but f k is u e k. So I'll put u + + + align:start position:0% +fi. Well but f k is u e k. So I'll put u +e k + + align:start position:0% +e k + + + align:start position:0% +e k +u fi. + + align:start position:0% +u fi. + + + align:start position:0% +u fi. +Now I can delete both + + align:start position:0% + + + + align:start position:0% + +U's and it's E + + align:start position:0% +U's and it's E + + + align:start position:0% +U's and it's E +K + + align:start position:0% +K + + + align:start position:0% +K +FI and I can remember what FI was which + + align:start position:0% +FI and I can remember what FI was which + + + align:start position:0% +FI and I can remember what FI was which +is E + + align:start position:0% +is E + + + align:start position:0% +is E +K + + align:start position:0% +K + + + align:start position:0% +K +U + + align:start position:0% +U + + + align:start position:0% +U +EI and it's just the same as the one we + + align:start position:0% +EI and it's just the same as the one we + + + align:start position:0% +EI and it's just the same as the one we +had there. So the operator unitary + + align:start position:0% +had there. So the operator unitary + + + align:start position:0% +had there. So the operator unitary +operator looks the same in both bases. + + align:start position:0% + + + + align:start position:0% + +Now, that might seem strange or a + + align:start position:0% +Now, that might seem strange or a + + + align:start position:0% +Now, that might seem strange or a +coincidence, but it's not. So, I leave + + align:start position:0% +coincidence, but it's not. So, I leave + + + align:start position:0% +coincidence, but it's not. So, I leave +it to you to think about that + + align:start position:0% +it to you to think about that + + + align:start position:0% +it to you to think about that +and visualize why did that + + align:start position:0% +and visualize why did that + + + align:start position:0% +and visualize why did that +happen? What's what's the reason? + + align:start position:0% + + + + align:start position:0% + +So the bracket notation we've been using + + align:start position:0% +So the bracket notation we've been using + + + align:start position:0% +So the bracket notation we've been using +it here and + + align:start position:0% +it here and + + + align:start position:0% +it here and +there and uh I will ask you to please + + align:start position:0% +there and uh I will ask you to please + + + align:start position:0% +there and uh I will ask you to please +read the notes. The notes will be posted + + align:start position:0% +read the notes. The notes will be posted + + + align:start position:0% +read the notes. The notes will be posted +this afternoon and they will have not + + align:start position:0% +this afternoon and they will have not + + + align:start position:0% +this afternoon and they will have not +maybe all we've done today but they will + + align:start position:0% +maybe all we've done today but they will + + + align:start position:0% +maybe all we've done today but they will +have some of what we'll do today and all + + align:start position:0% +have some of what we'll do today and all + + + align:start position:0% +have some of what we'll do today and all +of what we've been doing. And the way + + align:start position:0% +of what we've been doing. And the way + + + align:start position:0% +of what we've been doing. And the way +it's done is first done in the sort of + + align:start position:0% +it's done is first done in the sort of + + + align:start position:0% +it's done is first done in the sort of +inner product language and then things + + align:start position:0% +inner product language and then things + + + align:start position:0% +inner product language and then things +are done in the bracket language and + + align:start position:0% +are done in the bracket language and + + + align:start position:0% +are done in the bracket language and +it's a little repetitious and I'm trying + + align:start position:0% +it's a little repetitious and I'm trying + + + align:start position:0% +it's a little repetitious and I'm trying +to take out some things here and there + + align:start position:0% +to take out some things here and there + + + align:start position:0% +to take out some things here and there +so it's less repetitious but um at this + + align:start position:0% +so it's less repetitious but um at this + + + align:start position:0% +so it's less repetitious but um at this +moment it's probably worth reading it + + align:start position:0% +moment it's probably worth reading it + + + align:start position:0% +moment it's probably worth reading it +and reading it again. Yes. Uh is that + + align:start position:0% +and reading it again. Yes. Uh is that + + + align:start position:0% +and reading it again. Yes. Uh is that +true in reverse as well? If you have two + + align:start position:0% +true in reverse as well? If you have two + + + align:start position:0% +true in reverse as well? If you have two +orthonormal bases is the transformation + + align:start position:0% +orthonormal bases is the transformation + + + align:start position:0% +orthonormal bases is the transformation +necessarily unitary. + + align:start position:0% +necessarily unitary. + + + align:start position:0% +necessarily unitary. +Yes. + + align:start position:0% + + + + align:start position:0% + +Yes. All right. So, so as I was saying, + + align:start position:0% +Yes. All right. So, so as I was saying, + + + align:start position:0% +Yes. All right. So, so as I was saying, +we're going to go into the dra notation + + align:start position:0% +we're going to go into the dra notation + + + align:start position:0% +we're going to go into the dra notation +again. And here is an example of a place + + align:start position:0% +again. And here is an example of a place + + + align:start position:0% +again. And here is an example of a place +where everybody I think tends to use + + align:start position:0% +where everybody I think tends to use + + + align:start position:0% +where everybody I think tends to use +direct notation. And the reason is a a + + align:start position:0% +direct notation. And the reason is a a + + + align:start position:0% +direct notation. And the reason is a a +little curious and uh you will + + align:start position:0% +little curious and uh you will + + + align:start position:0% +little curious and uh you will +appreciate + + align:start position:0% +appreciate + + + align:start position:0% +appreciate +it quite + + align:start position:0% +it quite + + + align:start position:0% +it quite +fast. Um so this will be the case of + + align:start position:0% +fast. Um so this will be the case of + + + align:start position:0% +fast. Um so this will be the case of +where we return to X and P + + align:start position:0% +where we return to X and P + + + align:start position:0% +where we return to X and P +operators and uh nondenuable + + align:start position:0% +operators and uh nondenuable + + + align:start position:0% +operators and uh nondenuable +bases + + align:start position:0% +bases + + + align:start position:0% +bases +non + + align:start position:0% + + + + align:start position:0% + +denuablerable + + align:start position:0% + + + + align:start position:0% + +bases. So + + align:start position:0% +bases. So + + + align:start position:0% +bases. So +uh we're going to try to do X and P. Now + + align:start position:0% +uh we're going to try to do X and P. Now + + + align:start position:0% +uh we're going to try to do X and P. Now +this is the classic of dra notation. + + align:start position:0% +this is the classic of dra notation. + + + align:start position:0% +this is the classic of dra notation. +It's probably as I said the place where + + align:start position:0% +It's probably as I said the place where + + + align:start position:0% +It's probably as I said the place where +everybody likes to use direct notation + + align:start position:0% +everybody likes to use direct notation + + + align:start position:0% +everybody likes to use direct notation +and the reason it's efficient is because + + align:start position:0% +and the reason it's efficient is because + + + align:start position:0% +and the reason it's efficient is because +it prevents you from confusing two + + align:start position:0% +it prevents you from confusing two + + + align:start position:0% +it prevents you from confusing two +things. + + align:start position:0% +things. + + + align:start position:0% +things. +So what was the you know I I've written + + align:start position:0% +So what was the you know I I've written + + + align:start position:0% +So what was the you know I I've written +in the notes that we have all these V's + + align:start position:0% +in the notes that we have all these V's + + + align:start position:0% +in the notes that we have all these V's +that belong to the vector space and then + + align:start position:0% +that belong to the vector space and then + + + align:start position:0% +that belong to the vector space and then +we put this and we still say it belongs + + align:start position:0% +we put this and we still say it belongs + + + align:start position:0% +we put this and we still say it belongs +to the vector space and this is just a + + align:start position:0% +to the vector space and this is just a + + + align:start position:0% +to the vector space and this is just a +decoration that doesn't do + + align:start position:0% +decoration that doesn't do + + + align:start position:0% +decoration that doesn't do +much and we can play with this. Now in + + align:start position:0% +much and we can play with this. Now in + + + align:start position:0% +much and we can play with this. Now in +the non-denuable bases the catch and the + + align:start position:0% +the non-denuable bases the catch and the + + + align:start position:0% +the non-denuable bases the catch and the +possible confusion is that the label is + + align:start position:0% +possible confusion is that the label is + + + align:start position:0% +possible confusion is that the label is +not quite a vector in the vector space. + + align:start position:0% +not quite a vector in the vector space. + + + align:start position:0% +not quite a vector in the vector space. +So that that is the reason why the + + align:start position:0% +So that that is the reason why the + + + align:start position:0% +So that that is the reason why the +notation is helpful because it helps you + + align:start position:0% +notation is helpful because it helps you + + + align:start position:0% +notation is helpful because it helps you +and helps you distinguish two things + + align:start position:0% +and helps you distinguish two things + + + align:start position:0% +and helps you distinguish two things +that you could + + align:start position:0% +that you could + + + align:start position:0% +that you could +confuse. So here here we go. We're going + + align:start position:0% +confuse. So here here we go. We're going + + + align:start position:0% +confuse. So here here we go. We're going +to talk about coordinates X and the X + + align:start position:0% +to talk about coordinates X and the X + + + align:start position:0% +to talk about coordinates X and the X +operator and + + align:start position:0% +operator and + + + align:start position:0% +operator and +the states. Well, this is a state space. + + align:start position:0% +the states. Well, this is a state space. + + + align:start position:0% +the states. Well, this is a state space. +So, what kind of states do we have here? + + align:start position:0% +So, what kind of states do we have here? + + + align:start position:0% +So, what kind of states do we have here? +Well, we've talked about wave functions + + align:start position:0% +Well, we've talked about wave functions + + + align:start position:0% +Well, we've talked about wave functions +as we could give the value of the wave + + align:start position:0% +as we could give the value of the wave + + + align:start position:0% +as we could give the value of the wave +function at different places. We're + + align:start position:0% +function at different places. We're + + + align:start position:0% +function at different places. We're +going to go for a more intrinsic + + align:start position:0% +going to go for a more intrinsic + + + align:start position:0% +going to go for a more intrinsic +definition. We're going to try to + + align:start position:0% +definition. We're going to try to + + + align:start position:0% +definition. We're going to try to +introduce position + + align:start position:0% + + + + align:start position:0% + +states and position states will be + + align:start position:0% +states and position states will be + + + align:start position:0% +states and position states will be +called + + align:start position:0% +called + + + align:start position:0% +called +this + + align:start position:0% + + + + align:start position:0% + +x. Now what is the meaning of this + + align:start position:0% +x. Now what is the meaning of this + + + align:start position:0% +x. Now what is the meaning of this +position state? We should think of this + + align:start position:0% +position state? We should think of this + + + align:start position:0% +position state? We should think of this +intuitively as a + + align:start position:0% + + + + align:start position:0% + +particle at + + align:start position:0% + + + + align:start position:0% + +X. Now, here is how you can go wrong + + align:start position:0% +X. Now, here is how you can go wrong + + + align:start position:0% +X. Now, here is how you can go wrong +with this thing. If you stop + + align:start position:0% +with this thing. If you stop + + + align:start position:0% +with this thing. If you stop +thinking for a + + align:start position:0% + + + + align:start position:0% + +second, what is then ax? + + align:start position:0% +second, what is then ax? + + + align:start position:0% +second, what is then ax? +Is it a + + align:start position:0% + + + + align:start position:0% + +x? a being a number. Is it the same + + align:start position:0% +x? a being a number. Is it the same + + + align:start position:0% +x? a being a number. Is it the same +thing? No, not at all. This is a + + align:start position:0% +thing? No, not at all. This is a + + + align:start position:0% +thing? No, not at all. This is a +particle at the coordinate + + align:start position:0% +particle at the coordinate + + + align:start position:0% +particle at the coordinate +ax and this is a particle at x with some + + align:start position:0% +ax and this is a particle at x with some + + + align:start position:0% +ax and this is a particle at x with some +different + + align:start position:0% +different + + + align:start position:0% +different +amplitude. Very different. So this is + + align:start position:0% +amplitude. Very different. So this is + + + align:start position:0% +amplitude. Very different. So this is +not true. Typical mistake. This is not + + align:start position:0% +not true. Typical mistake. This is not + + + align:start position:0% +not true. Typical mistake. This is not +uh minus + + align:start position:0% +uh minus + + + align:start position:0% +uh minus +x. That that's totally different. So + + align:start position:0% +x. That that's totally different. So + + + align:start position:0% +x. That that's totally different. So +there's no such thing as this + + align:start position:0% + + + + align:start position:0% + +either linear. It doesn't mean anything. + + align:start position:0% +either linear. It doesn't mean anything. + + + align:start position:0% +either linear. It doesn't mean anything. +And the reason is that these things are + + align:start position:0% +And the reason is that these things are + + + align:start position:0% +And the reason is that these things are +not our vectors. Our vector is this + + align:start position:0% +not our vectors. Our vector is this + + + align:start position:0% +not our vectors. Our vector is this +whole thing that says a particle at X. + + align:start position:0% +whole thing that says a particle at X. + + + align:start position:0% +whole thing that says a particle at X. +Maybe to make the + + align:start position:0% +Maybe to make the + + + align:start position:0% +Maybe to make the +the a clearer impression, imagine you're + + align:start position:0% +the a clearer impression, imagine you're + + + align:start position:0% +the a clearer impression, imagine you're +in three dimensions and you have an X + + align:start position:0% +in three dimensions and you have an X + + + align:start position:0% +in three dimensions and you have an X +vector. So then you have the K. + + align:start position:0% + + + + align:start position:0% + +This this is the cat particle at + + align:start position:0% +This this is the cat particle at + + + align:start position:0% +This this is the cat particle at +x. X is now a vector but it's a + + align:start position:0% +x. X is now a vector but it's a + + + align:start position:0% +x. X is now a vector but it's a +three-dimensional vector. This is a + + align:start position:0% +three-dimensional vector. This is a + + + align:start position:0% +three-dimensional vector. This is a +vector but it's a vector in an infinite + + align:start position:0% +vector but it's a vector in an infinite + + + align:start position:0% +vector but it's a vector in an infinite +dimensional + + align:start position:0% +dimensional + + + align:start position:0% +dimensional +space because a particle can be + + align:start position:0% +space because a particle can be + + + align:start position:0% +space because a particle can be +anywhere. So this is a vector in quantum + + align:start position:0% +anywhere. So this is a vector in quantum + + + align:start position:0% +anywhere. So this is a vector in quantum +mechanics. This is a complex vector + + align:start position:0% +mechanics. This is a complex vector + + + align:start position:0% +mechanics. This is a complex vector +space. This is a real vector space and + + align:start position:0% +space. This is a real vector space and + + + align:start position:0% +space. This is a real vector space and +it's the label here. So again min - x is + + align:start position:0% +it's the label here. So again min - x is + + + align:start position:0% +it's the label here. So again min - x is +not + + align:start position:0% +not + + + align:start position:0% +not +minus x vector. It it's not the vector. + + align:start position:0% +minus x vector. It it's not the vector. + + + align:start position:0% +minus x vector. It it's not the vector. +The addition of the bra has moved you + + align:start position:0% +The addition of the bra has moved you + + + align:start position:0% +The addition of the bra has moved you +from vectors that you're familiar with + + align:start position:0% +from vectors that you're familiar with + + + align:start position:0% +from vectors that you're familiar with +to states that are a little more + + align:start position:0% +to states that are a little more + + + align:start position:0% +to states that are a little more +abstract. + + align:start position:0% + + + + align:start position:0% + +So the reason this notation is quite + + align:start position:0% +So the reason this notation is quite + + + align:start position:0% +So the reason this notation is quite +good is because this is a number but + + align:start position:0% +good is because this is a number but + + + align:start position:0% +good is because this is a number but +this is or this is a coordinate and this + + align:start position:0% +this is or this is a coordinate and this + + + align:start position:0% +this is or this is a coordinate and this +is a vector already. + + align:start position:0% +is a vector already. + + + align:start position:0% +is a vector already. +So these are going to be our basis + + align:start position:0% +So these are going to be our basis + + + align:start position:0% +So these are going to be our basis +states and they're + + align:start position:0% + + + + align:start position:0% + +non-denuable basis + + align:start position:0% +non-denuable basis + + + align:start position:0% +non-denuable basis +states. And here you can have that all x + + align:start position:0% +states. And here you can have that all x + + + align:start position:0% +states. And here you can have that all x +must belong to the real numbers because + + align:start position:0% +must belong to the real numbers because + + + align:start position:0% +must belong to the real numbers because +we have particles in a + + align:start position:0% +we have particles in a + + + align:start position:0% +we have particles in a +line. While this thing can be changed by + + align:start position:0% +line. While this thing can be changed by + + + align:start position:0% +line. While this thing can be changed by +real numbers, the states can be + + align:start position:0% +real numbers, the states can be + + + align:start position:0% +real numbers, the states can be +multiplied by complex numbers because + + align:start position:0% +multiplied by complex numbers because + + + align:start position:0% +multiplied by complex numbers because +we're doing quantum mechanics. + + align:start position:0% + + + + align:start position:0% + +So if you want to define a vector space + + align:start position:0% +So if you want to define a vector space + + + align:start position:0% +So if you want to define a vector space +now this is all infinite dimensional + + align:start position:0% +now this is all infinite dimensional + + + align:start position:0% +now this is all infinite dimensional +it's a little worse in the sense the + + align:start position:0% +it's a little worse in the sense the + + + align:start position:0% +it's a little worse in the sense the +basis is non-enuable. If I use this + + align:start position:0% +basis is non-enuable. If I use this + + + align:start position:0% +basis is non-enuable. If I use this +basis I cannot make a list of all the + + align:start position:0% +basis I cannot make a list of all the + + + align:start position:0% +basis I cannot make a list of all the +basis + + align:start position:0% +basis + + + align:start position:0% +basis +vectors. So for the inner product we + + align:start position:0% +vectors. So for the inner product we + + + align:start position:0% +vectors. So for the inner product we +will take the following. We will take x + + align:start position:0% +will take the following. We will take x + + + align:start position:0% +will take the following. We will take x +with + + align:start position:0% +with + + + align:start position:0% +with +y to be delta of x - + + align:start position:0% +y to be delta of x - + + + align:start position:0% +y to be delta of x - +y. That will be our inner product. And + + align:start position:0% +y. That will be our inner product. And + + + align:start position:0% +y. That will be our inner product. And +it has all the properties of the inner + + align:start position:0% +it has all the properties of the inner + + + align:start position:0% +it has all the properties of the inner +product + + align:start position:0% +product + + + align:start position:0% +product +um that we may + + align:start position:0% +um that we may + + + align:start position:0% +um that we may +want. And + + align:start position:0% +want. And + + + align:start position:0% +want. And +uh what else? Well, at this moment we + + align:start position:0% +uh what else? Well, at this moment we + + + align:start position:0% +uh what else? Well, at this moment we +can try to this this is physically + + align:start position:0% +can try to this this is physically + + + align:start position:0% +can try to this this is physically +sensible. Let me say because if you have + + align:start position:0% +sensible. Let me say because if you have + + + align:start position:0% +sensible. Let me say because if you have +a particle at one point and a particle + + align:start position:0% +a particle at one point and a particle + + + align:start position:0% +a particle at one point and a particle +at another point, the amplitude that + + align:start position:0% +at another point, the amplitude that + + + align:start position:0% +at another point, the amplitude that +this particle at one point is at this + + align:start position:0% +this particle at one point is at this + + + align:start position:0% +this particle at one point is at this +other point is zero. And these states + + align:start position:0% +other point is zero. And these states + + + align:start position:0% +other point is zero. And these states +are not normalizable. They correspond to + + align:start position:0% +are not normalizable. They correspond to + + + align:start position:0% +are not normalizable. They correspond to +a particle at a point. So once you try + + align:start position:0% +a particle at a point. So once you try + + + align:start position:0% +a particle at a point. So once you try +to normalize them, you get infinity and + + align:start position:0% +to normalize them, you get infinity and + + + align:start position:0% +to normalize them, you get infinity and +you can't do much. But what you can do + + align:start position:0% +you can't do much. But what you can do + + + align:start position:0% +you can't do much. But what you can do +here is uh state more of the properties + + align:start position:0% +here is uh state more of the properties + + + align:start position:0% +here is uh state more of the properties +and learn how to manipulate this. So + + align:start position:0% +and learn how to manipulate this. So + + + align:start position:0% +and learn how to manipulate this. So +remember we had one was the sum + + align:start position:0% +remember we had one was the sum + + + align:start position:0% +remember we had one was the sum +of all + + align:start position:0% + + + + align:start position:0% + +ei the unit operator was + + align:start position:0% +ei the unit operator was + + + align:start position:0% +ei the unit operator was +that well let's try to write a similar + + align:start position:0% +that well let's try to write a similar + + + align:start position:0% +that well let's try to write a similar +one. + + align:start position:0% +one. + + + align:start position:0% +one. +The unit operator will be the sum over + + align:start position:0% +The unit operator will be the sum over + + + align:start position:0% +The unit operator will be the sum over +all + + align:start position:0% + + + + align:start position:0% + +x's. And uh you could say, well, looks + + align:start position:0% +x's. And uh you could say, well, looks + + + align:start position:0% +x's. And uh you could say, well, looks +reasonable, but maybe there's a 1/2 in + + align:start position:0% +reasonable, but maybe there's a 1/2 in + + + align:start position:0% +reasonable, but maybe there's a 1/2 in +here or some factor. Well, no factor is + + align:start position:0% +here or some factor. Well, no factor is + + + align:start position:0% +here or some factor. Well, no factor is +needed. You can check that that you've + + align:start position:0% +needed. You can check that that you've + + + align:start position:0% +needed. You can check that that you've +defined this thing + + align:start position:0% +defined this thing + + + align:start position:0% +defined this thing +properly. So, let me do it. + + align:start position:0% +properly. So, let me do it. + + + align:start position:0% +properly. So, let me do it. +So act on this so-called resolution of + + align:start position:0% +So act on this so-called resolution of + + + align:start position:0% +So act on this so-called resolution of +the identity with the vector y. So one + + align:start position:0% +the identity with the vector y. So one + + + align:start position:0% +the identity with the vector y. So one +on + + align:start position:0% +on + + + align:start position:0% +on +y is equal to y. And now let's act on + + align:start position:0% +y is equal to y. And now let's act on + + + align:start position:0% +y is equal to y. And now let's act on +the + + align:start position:0% +the + + + align:start position:0% +the +right. x + + align:start position:0% +right. x + + + align:start position:0% +right. x +x y. This is delta of x - y. And then + + align:start position:0% +x y. This is delta of x - y. And then + + + align:start position:0% +x y. This is delta of x - y. And then +when you integrate you get y. + + align:start position:0% +when you integrate you get y. + + + align:start position:0% +when you integrate you get y. +So we're + + align:start position:0% + + + + align:start position:0% + +fine. So this looks a little too + + align:start position:0% +fine. So this looks a little too + + + align:start position:0% +fine. So this looks a little too +abstract, but it's not abstract if you + + align:start position:0% +abstract, but it's not abstract if you + + + align:start position:0% +abstract, but it's not abstract if you +now introduce wave functions. So let's + + align:start position:0% +now introduce wave functions. So let's + + + align:start position:0% +now introduce wave functions. So let's +do wave functions. So um you have a + + align:start position:0% +do wave functions. So um you have a + + + align:start position:0% +do wave functions. So um you have a +particle a state of a particle + + align:start position:0% +particle a state of a particle + + + align:start position:0% +particle a state of a particle +pi. Time would be irrelevant. So I will + + align:start position:0% +pi. Time would be irrelevant. So I will + + + align:start position:0% +pi. Time would be irrelevant. So I will +put just this pi like that without the + + align:start position:0% +put just this pi like that without the + + + align:start position:0% +put just this pi like that without the +bottom + + align:start position:0% +bottom + + + align:start position:0% +bottom +line. And uh let's look at it. Oh, I + + align:start position:0% +line. And uh let's look at it. Oh, I + + + align:start position:0% +line. And uh let's look at it. Oh, I +want to say one more thing. + + align:start position:0% +want to say one more thing. + + + align:start position:0% +want to say one more thing. +Um the x + + align:start position:0% +Um the x + + + align:start position:0% +Um the x +operator acts on the x states to give + + align:start position:0% + + + + align:start position:0% + +x. So these are states of the x + + align:start position:0% +x. So these are states of the x + + + align:start position:0% +x. So these are states of the x +operator. We declare them to be igon + + align:start position:0% +operator. We declare them to be igon + + + align:start position:0% +operator. We declare them to be igon +states of the x operator with iggon + + align:start position:0% +states of the x operator with iggon + + + align:start position:0% +states of the x operator with iggon +value x. That's their physical + + align:start position:0% +value x. That's their physical + + + align:start position:0% +value x. That's their physical +interpretation. I probably should have + + align:start position:0% +interpretation. I probably should have + + + align:start position:0% +interpretation. I probably should have +said that + + align:start position:0% +said that + + + align:start position:0% +said that +before. Now if we have a + + align:start position:0% +before. Now if we have a + + + align:start position:0% +before. Now if we have a +pi as a state or a vector, how do we get + + align:start position:0% +pi as a state or a vector, how do we get + + + align:start position:0% +pi as a state or a vector, how do we get +the wave function? Well, in this + + align:start position:0% +the wave function? Well, in this + + + align:start position:0% +the wave function? Well, in this +language, the wave function which we + + align:start position:0% +language, the wave function which we + + + align:start position:0% +language, the wave function which we +call p of x is defined to be the overlap + + align:start position:0% +call p of x is defined to be the overlap + + + align:start position:0% +call p of x is defined to be the overlap +of x with pi. + + align:start position:0% + + + + align:start position:0% + +And that makes sense because this + + align:start position:0% +And that makes sense because this + + + align:start position:0% +And that makes sense because this +overlap is a function of this label here + + align:start position:0% +overlap is a function of this label here + + + align:start position:0% +overlap is a function of this label here +where the particle is and therefore the + + align:start position:0% +where the particle is and therefore the + + + align:start position:0% +where the particle is and therefore the +result is a complex number that is + + align:start position:0% +result is a complex number that is + + + align:start position:0% +result is a complex number that is +dependent on x. So this belongs to the + + align:start position:0% +dependent on x. So this belongs to the + + + align:start position:0% +dependent on x. So this belongs to the +complex numbers because inner products + + align:start position:0% +complex numbers because inner products + + + align:start position:0% +complex numbers because inner products +can have complex numbers. Now I didn't + + align:start position:0% +can have complex numbers. Now I didn't + + + align:start position:0% +can have complex numbers. Now I didn't +put any complex number here but when you + + align:start position:0% +put any complex number here but when you + + + align:start position:0% +put any complex number here but when you +form states you can superpose states + + align:start position:0% +form states you can superpose states + + + align:start position:0% +form states you can superpose states +with complex numbers. So this pi of x + + align:start position:0% +with complex numbers. So this pi of x + + + align:start position:0% +with complex numbers. So this pi of x +will come out this + + align:start position:0% +will come out this + + + align:start position:0% +will come out this +way. And now you can now that you're + + align:start position:0% +way. And now you can now that you're + + + align:start position:0% +way. And now you can now that you're +armed with that you can even think of + + align:start position:0% +armed with that you can even think of + + + align:start position:0% +armed with that you can even think of +this in a nicer way. The state p is + + align:start position:0% +this in a nicer way. The state p is + + + align:start position:0% +this in a nicer way. The state p is +equal to 1 * p and then use the res this + + align:start position:0% +equal to 1 * p and then use the res this + + + align:start position:0% +equal to 1 * p and then use the res this +formula. So this is integral + + align:start position:0% +formula. So this is integral + + + align:start position:0% +formula. So this is integral +dx x x + + align:start position:0% + + + + align:start position:0% + +x and again the bracket notation is + + align:start position:0% +x and again the bracket notation is + + + align:start position:0% +x and again the bracket notation is +quite nice because the brow already + + align:start position:0% +quite nice because the brow already + + + align:start position:0% +quite nice because the brow already +meets the k. This is a number and this + + align:start position:0% +meets the k. This is a number and this + + + align:start position:0% +meets the k. This is a number and this +is + + align:start position:0% +is + + + align:start position:0% +is +dx x s of + + align:start position:0% + + + + align:start position:0% + +x. This equation has a nice + + align:start position:0% +x. This equation has a nice + + + align:start position:0% +x. This equation has a nice +interpretation. It says that the state + + align:start position:0% +interpretation. It says that the state + + + align:start position:0% +interpretation. It says that the state +is a superposition of the basis states + + align:start position:0% +is a superposition of the basis states + + + align:start position:0% +is a superposition of the basis states +the position states and the component of + + align:start position:0% +the position states and the component of + + + align:start position:0% +the position states and the component of +your original state along the basis + + align:start position:0% +your original state along the basis + + + align:start position:0% +your original state along the basis +state x is precisely the value of the + + align:start position:0% +state x is precisely the value of the + + + align:start position:0% +state x is precisely the value of the +wave function at x. So the wave function + + align:start position:0% +wave function at x. So the wave function + + + align:start position:0% +wave function at x. So the wave function +at x is giving you the weight of the + + align:start position:0% +at x is giving you the weight of the + + + align:start position:0% +at x is giving you the weight of the +state x as it enters into the sum. + + align:start position:0% + + + + align:start position:0% + +So one can compute more things. Uh you + + align:start position:0% +So one can compute more things. Uh you + + + align:start position:0% +So one can compute more things. Uh you +will get practice on this type of + + align:start position:0% +will get practice on this type of + + + align:start position:0% +will get practice on this type of +computations. They're just limited type + + align:start position:0% +computations. They're just limited type + + + align:start position:0% +computations. They're just limited type +of variations that you can do. So uh + + align:start position:0% +of variations that you can do. So uh + + + align:start position:0% +of variations that you can do. So uh +it's not that + + align:start position:0% +it's not that + + + align:start position:0% +it's not that +um complicated. Basically you can + + align:start position:0% +um complicated. Basically you can + + + align:start position:0% +um complicated. Basically you can +introduce resolutions of the identity + + align:start position:0% +introduce resolutions of the identity + + + align:start position:0% +introduce resolutions of the identity +wherever you need them. And uh if you + + align:start position:0% +wherever you need them. And uh if you + + + align:start position:0% +wherever you need them. And uh if you +introduce too many you waste time but um + + align:start position:0% +introduce too many you waste time but um + + + align:start position:0% +introduce too many you waste time but um +you typically get the answer anyway. Um + + align:start position:0% +you typically get the answer anyway. Um + + + align:start position:0% +you typically get the answer anyway. Um +so it's it's not too serious. Um so + + align:start position:0% +so it's it's not too serious. Um so + + + align:start position:0% +so it's it's not too serious. Um so +suppose you want to understand what is + + align:start position:0% +suppose you want to understand what is + + + align:start position:0% +suppose you want to understand what is +the inner product of two + + align:start position:0% + + + + align:start position:0% + +states. Put a resolution of the identity + + align:start position:0% +states. Put a resolution of the identity + + + align:start position:0% +states. Put a resolution of the identity +in between. So put five and then put the + + align:start position:0% +in between. So put five and then put the + + + align:start position:0% +in between. So put five and then put the +integral + + align:start position:0% +integral + + + align:start position:0% +integral +dx x + + align:start position:0% + + + + align:start position:0% + +x. Well, the integral goes out and you + + align:start position:0% +x. Well, the integral goes out and you + + + align:start position:0% +x. Well, the integral goes out and you +get five + + align:start position:0% +get five + + + align:start position:0% +get five +x + + align:start position:0% +x + + + align:start position:0% +x +xi and uh remember if x psi is s of + + align:start position:0% +xi and uh remember if x psi is s of + + + align:start position:0% +xi and uh remember if x psi is s of +x 5x is the complex conjugate. So it's + + align:start position:0% +x 5x is the complex conjugate. So it's + + + align:start position:0% +x 5x is the complex conjugate. So it's +phi star of x and that's what you know + + align:start position:0% +phi star of x and that's what you know + + + align:start position:0% +phi star of x and that's what you know +you knew that if you have two wave + + align:start position:0% +you knew that if you have two wave + + + align:start position:0% +you knew that if you have two wave +functions and you want to compute their + + align:start position:0% +functions and you want to compute their + + + align:start position:0% +functions and you want to compute their +overlap you integrate the complex + + align:start position:0% +overlap you integrate the complex + + + align:start position:0% +overlap you integrate the complex +conjugate of one against the + + align:start position:0% +conjugate of one against the + + + align:start position:0% +conjugate of one against the +other. So this notation is doing all + + align:start position:0% +other. So this notation is doing all + + + align:start position:0% +other. So this notation is doing all +what you want from + + align:start position:0% + + + + align:start position:0% + +this. You want to compute a matrix + + align:start position:0% +this. You want to compute a matrix + + + align:start position:0% +this. You want to compute a matrix +element of + + align:start position:0% + + + + align:start position:0% + +X. Well, put another resolution of the + + align:start position:0% +X. Well, put another resolution of the + + + align:start position:0% +X. Well, put another resolution of the +identity + + align:start position:0% +identity + + + align:start position:0% +identity +here. So this would be integral + + align:start position:0% +here. So this would be integral + + + align:start position:0% +here. So this would be integral +dx fi the x hat is here and then you put + + align:start position:0% +dx fi the x hat is here and then you put + + + align:start position:0% +dx fi the x hat is here and then you put +x + + align:start position:0% + + + + align:start position:0% + +x the x hat on x is x that's what this + + align:start position:0% +x the x hat on x is x that's what this + + + align:start position:0% +x the x hat on x is x that's what this +operator does. So you get integral dx of + + align:start position:0% +operator does. So you get integral dx of + + + align:start position:0% +operator does. So you get integral dx of +um I'll put + + align:start position:0% +um I'll put + + + align:start position:0% +um I'll put +x + + align:start position:0% +x + + + align:start position:0% +x +5x x pi which is what you expect it to + + align:start position:0% +5x x pi which is what you expect it to + + + align:start position:0% +5x x pi which is what you expect it to +be integral of x 5 star of x pi of x. + + align:start position:0% + + + + align:start position:0% + +Now we can do exactly the same thing + + align:start position:0% +Now we can do exactly the same thing + + + align:start position:0% +Now we can do exactly the same thing +with momentum states. So I don't want to + + align:start position:0% +with momentum states. So I don't want to + + + align:start position:0% +with momentum states. So I don't want to +bore you. So I just list the properties. + + align:start position:0% +bore you. So I just list the properties. + + + align:start position:0% +bore you. So I just list the properties. +Basis + + align:start position:0% + + + + align:start position:0% + +states are momenta where the momenta is + + align:start position:0% +states are momenta where the momenta is + + + align:start position:0% +states are momenta where the momenta is +real. P prime p is equal delta of p + + align:start position:0% +real. P prime p is equal delta of p + + + align:start position:0% +real. P prime p is equal delta of p +minus p prime. + + align:start position:0% +minus p prime. + + + align:start position:0% +minus p prime. +1 is the integral DP of P + + align:start position:0% +1 is the integral DP of P + + + align:start position:0% +1 is the integral DP of P +P and P hat P is equal to P + + align:start position:0% + + + + align:start position:0% + +P. So these are the momentum basis is + + align:start position:0% +P. So these are the momentum basis is + + + align:start position:0% +P. So these are the momentum basis is +exactly analogous. So all what we've + + align:start position:0% +exactly analogous. So all what we've + + + align:start position:0% +exactly analogous. So all what we've +done for X is true. the completeness and + + align:start position:0% +done for X is true. the completeness and + + + align:start position:0% +done for X is true. the completeness and +normalization are well work well + + align:start position:0% +normalization are well work well + + + align:start position:0% +normalization are well work well +together like we check there and + + align:start position:0% +together like we check there and + + + align:start position:0% +together like we check there and +everything is true. The only thing that + + align:start position:0% +everything is true. The only thing that + + + align:start position:0% +everything is true. The only thing that +you need to make this + + align:start position:0% +you need to make this + + + align:start position:0% +you need to make this +more interesting is a relation between + + align:start position:0% +more interesting is a relation between + + + align:start position:0% +more interesting is a relation between +the x basis and the p basis and that's + + align:start position:0% +the x basis and the p basis and that's + + + align:start position:0% +the x basis and the p basis and that's +where physics comes in. Anybody can + + align:start position:0% +where physics comes in. Anybody can + + + align:start position:0% +where physics comes in. Anybody can +define this too. But then a physical + + align:start position:0% +define this too. But then a physical + + + align:start position:0% +define this too. But then a physical +assumption as to what you really mean by + + align:start position:0% +assumption as to what you really mean by + + + align:start position:0% +assumption as to what you really mean by +momentum + + align:start position:0% +momentum + + + align:start position:0% +momentum +um is necessary. And what we've said is + + align:start position:0% +um is necessary. And what we've said is + + + align:start position:0% +um is necessary. And what we've said is +that the wave function of a particle + + align:start position:0% +that the wave function of a particle + + + align:start position:0% +that the wave function of a particle +with momentum + + align:start position:0% +with momentum + + + align:start position:0% +with momentum +P is e to the + + align:start position:0% +P is e to the + + + align:start position:0% +P is e to the +ip x over h + + align:start position:0% +ip x over h + + + align:start position:0% +ip x over h +bar over square<unk> of 2 pih. + + align:start position:0% +bar over square<unk> of 2 pih. + + + align:start position:0% +bar over square<unk> of 2 pih. +convenient normalization but + + align:start position:0% +convenient normalization but + + + align:start position:0% +convenient normalization but +uh but that was it. That was our + + align:start position:0% +uh but that was it. That was our + + + align:start position:0% +uh but that was it. That was our +physical interpretation of the wave + + align:start position:0% +physical interpretation of the wave + + + align:start position:0% +physical interpretation of the wave +function of a particle with some + + align:start position:0% +function of a particle with some + + + align:start position:0% +function of a particle with some +momentum. And therefore if this is a + + align:start position:0% +momentum. And therefore if this is a + + + align:start position:0% +momentum. And therefore if this is a +wave function that's + + align:start position:0% + + + + align:start position:0% + +XP a state of momentum P has this wave + + align:start position:0% +XP a state of momentum P has this wave + + + align:start position:0% +XP a state of momentum P has this wave +function. So we write this + + align:start position:0% + + + + align:start position:0% + +Okay. Uh there are checks you can do and + + align:start position:0% +Okay. Uh there are checks you can do and + + + align:start position:0% +Okay. Uh there are checks you can do and +please read the notes but uh let's do a + + align:start position:0% +please read the notes but uh let's do a + + + align:start position:0% +please read the notes but uh let's do a +little computation. Suppose you want to + + align:start position:0% +little computation. Suppose you want to + + + align:start position:0% +little computation. Suppose you want to +compute what is p on + + align:start position:0% +compute what is p on + + + align:start position:0% +compute what is p on +pi and you can say well I don't know why + + align:start position:0% +pi and you can say well I don't know why + + + align:start position:0% +pi and you can say well I don't know why +why would I want to do something with + + align:start position:0% +why would I want to do something with + + + align:start position:0% +why would I want to do something with +that looks simple enough. Well, it's + + align:start position:0% +that looks simple enough. Well, it's + + + align:start position:0% +that looks simple enough. Well, it's +simple enough, but you could say, I want + + align:start position:0% +simple enough, but you could say, I want + + + align:start position:0% +simple enough, but you could say, I want +to see it in terms of wave + + align:start position:0% +to see it in terms of wave + + + align:start position:0% +to see it in terms of wave +functions, coordinate space wave + + align:start position:0% +functions, coordinate space wave + + + align:start position:0% +functions, coordinate space wave +functions. Well, if you want to see them + + align:start position:0% +functions. Well, if you want to see them + + + align:start position:0% +functions. Well, if you want to see them +in terms of coordinate space wave + + align:start position:0% +in terms of coordinate space wave + + + align:start position:0% +in terms of coordinate space wave +functions, you have to introduce a + + align:start position:0% +functions, you have to introduce a + + + align:start position:0% +functions, you have to introduce a +complete set of states. So, + + align:start position:0% +complete set of states. So, + + + align:start position:0% +complete set of states. So, +introduce P + + align:start position:0% + + + + align:start position:0% + +XI. Then you have this wave function and + + align:start position:0% +XI. Then you have this wave function and + + + align:start position:0% +XI. Then you have this wave function and +oh, this is sort of known because it's + + align:start position:0% +oh, this is sort of known because it's + + + align:start position:0% +oh, this is sort of known because it's +the complex conjugate of this. So it's + + align:start position:0% +the complex conjugate of this. So it's + + + align:start position:0% +the complex conjugate of this. So it's +integral + + align:start position:0% + + + + align:start position:0% + +dx px / h bar square<unk> of 2 pi h bar + + align:start position:0% +dx px / h bar square<unk> of 2 pi h bar + + + align:start position:0% +dx px / h bar square<unk> of 2 pi h bar +time p s of + + align:start position:0% +time p s of + + + align:start position:0% +time p s of +x and this was the fia transform what we + + align:start position:0% +x and this was the fia transform what we + + + align:start position:0% +x and this was the fia transform what we +call the fia transform of the wave + + align:start position:0% +call the fia transform of the wave + + + align:start position:0% +call the fia transform of the wave +function. So we can call it sit tilda of + + align:start position:0% + + + + align:start position:0% + +p just to distinguish it. Uh because we + + align:start position:0% +p just to distinguish it. Uh because we + + + align:start position:0% +p just to distinguish it. Uh because we +call pi with x p s p s p s p s p s p s p + + align:start position:0% +call pi with x p s p s p s p s p s p s p + + + align:start position:0% +call pi with x p s p s p s p s p s p s p +s p s p s p s p of x. So if I didn't put + + align:start position:0% +s p s p s p s p of x. So if I didn't put + + + align:start position:0% +s p s p s p s p of x. So if I didn't put +a tilda, you might think it's the same + + align:start position:0% +a tilda, you might think it's the same + + + align:start position:0% +a tilda, you might think it's the same +functional form, but it's the momentum + + align:start position:0% +functional form, but it's the momentum + + + align:start position:0% +functional form, but it's the momentum +space wave + + align:start position:0% +space wave + + + align:start position:0% +space wave +function. So uh here is the wave + + align:start position:0% +function. So uh here is the wave + + + align:start position:0% +function. So uh here is the wave +function in the p basis. It's the FIA + + align:start position:0% +function in the p basis. It's the FIA + + + align:start position:0% +function in the p basis. It's the FIA +transform of the wave function in the x + + align:start position:0% +transform of the wave function in the x + + + align:start position:0% +transform of the wave function in the x +basis. + + align:start position:0% +basis. + + + align:start position:0% +basis. +One last computation and then we change + + align:start position:0% +One last computation and then we change + + + align:start position:0% +One last computation and then we change +subjects + + align:start position:0% + + + + align:start position:0% + +again. It's the classic + + align:start position:0% +again. It's the classic + + + align:start position:0% +again. It's the classic +computation + + align:start position:0% +computation + + + align:start position:0% +computation +that you have now a mixed situation in + + align:start position:0% +that you have now a mixed situation in + + + align:start position:0% +that you have now a mixed situation in +which you have the momentum operator + + align:start position:0% +which you have the momentum operator + + + align:start position:0% +which you have the momentum operator +states and a coordinate um bra. So what + + align:start position:0% + + + + align:start position:0% + +is is the following expression + + align:start position:0% +is is the following expression + + + align:start position:0% +is is the following expression +um + + align:start position:0% + + + + align:start position:0% + +x p + + align:start position:0% +x p + + + align:start position:0% +x p +hat s. + + align:start position:0% + + + + align:start position:0% + +Okay. What is your temptation? Your + + align:start position:0% +Okay. What is your temptation? Your + + + align:start position:0% +Okay. What is your temptation? Your +temptation is to say + + align:start position:0% +temptation is to say + + + align:start position:0% +temptation is to say +look this is like the momentum + + align:start position:0% +look this is like the momentum + + + align:start position:0% +look this is like the momentum +operator acting on the wave function in + + align:start position:0% +operator acting on the wave function in + + + align:start position:0% +operator acting on the wave function in +the x basis. It can only be har over i + + align:start position:0% +the x basis. It can only be har over i + + + align:start position:0% +the x basis. It can only be har over i +dx of s of x. That's probably what it + + align:start position:0% +dx of s of x. That's probably what it + + + align:start position:0% +dx of s of x. That's probably what it +means. Um but the notation is clear + + align:start position:0% +means. Um but the notation is clear + + + align:start position:0% +means. Um but the notation is clear +enough so we can check if that is + + align:start position:0% +enough so we can check if that is + + + align:start position:0% +enough so we can check if that is +exactly what it is. We we can manipulate + + align:start position:0% +exactly what it is. We we can manipulate + + + align:start position:0% +exactly what it is. We we can manipulate +things already. So let's do it. So for + + align:start position:0% +things already. So let's do it. So for + + + align:start position:0% +things already. So let's do it. So for +that I first have to try to get rid of + + align:start position:0% +that I first have to try to get rid of + + + align:start position:0% +that I first have to try to get rid of +this operator. Now the only way I know + + align:start position:0% +this operator. Now the only way I know + + + align:start position:0% +this operator. Now the only way I know +how to get rid of this operator P is + + align:start position:0% +how to get rid of this operator P is + + + align:start position:0% +how to get rid of this operator P is +because it + + align:start position:0% +because it + + + align:start position:0% +because it +has state. So it suggests very strongly + + align:start position:0% +has state. So it suggests very strongly + + + align:start position:0% +has state. So it suggests very strongly +that we should introduce momentum states + + align:start position:0% +that we should introduce momentum states + + + align:start position:0% +that we should introduce momentum states +completeness. So I'll put + + align:start position:0% +completeness. So I'll put + + + align:start position:0% +completeness. So I'll put +DP X P hat + + align:start position:0% + + + + align:start position:0% + +P S P S P S P S P S P S P S P S P S P S + + align:start position:0% + + + + align:start position:0% + +P and now I can evaluate a + + align:start position:0% +P and now I can evaluate a + + + align:start position:0% +P and now I can evaluate a +little because P hat and P is little P + + align:start position:0% +little because P hat and P is little P + + + align:start position:0% +little because P hat and P is little P +or P without the hat. So this is + + align:start position:0% +or P without the hat. So this is + + + align:start position:0% +or P without the hat. So this is +P XP + + align:start position:0% + + + + align:start position:0% + +P S P S P S P S P S P S P S P S P S P S + + align:start position:0% + + + + align:start position:0% + +P + + align:start position:0% +P + + + align:start position:0% +P +Now you can uh look at that and and + + align:start position:0% +Now you can uh look at that and and + + + align:start position:0% +Now you can uh look at that and and +think + + align:start position:0% +think + + + align:start position:0% +think +carefully what should you do and there's + + align:start position:0% +carefully what should you do and there's + + + align:start position:0% +carefully what should you do and there's +one thing that you can + + align:start position:0% +one thing that you can + + + align:start position:0% +one thing that you can +do is uh look at the equation on top and + + align:start position:0% +do is uh look at the equation on top and + + + align:start position:0% +do is uh look at the equation on top and +this is a way to avoid working very + + align:start position:0% +this is a way to avoid working very + + + align:start position:0% +this is a way to avoid working very +hard. So look at the equation on top. XP + + align:start position:0% +hard. So look at the equation on top. XP + + + align:start position:0% +hard. So look at the equation on top. XP +is equal to that. How do I get a P to + + align:start position:0% +is equal to that. How do I get a P to + + + align:start position:0% +is equal to that. How do I get a P to +multiply this? I can get a P to multiply + + align:start position:0% +multiply this? I can get a P to multiply + + + align:start position:0% +multiply this? I can get a P to multiply +this + + align:start position:0% +this + + + align:start position:0% +this +XP by doing H bar over + + align:start position:0% +XP by doing H bar over + + + align:start position:0% +XP by doing H bar over +I + + align:start position:0% +I + + + align:start position:0% +I +ddx + + align:start position:0% +ddx + + + align:start position:0% +ddx +of XP. + + align:start position:0% + + + + align:start position:0% + +Because if I see it there, I see that + + align:start position:0% +Because if I see it there, I see that + + + align:start position:0% +Because if I see it there, I see that +differentiating by h by ddx brings down + + align:start position:0% +differentiating by h by ddx brings down + + + align:start position:0% +differentiating by h by ddx brings down +an ip over h bar. So if I multiply by h + + align:start position:0% +an ip over h bar. So if I multiply by h + + + align:start position:0% +an ip over h bar. So if I multiply by h +bar over i, I get that. So let's do + + align:start position:0% +bar over i, I get that. So let's do + + + align:start position:0% +bar over i, I get that. So let's do +this. + + align:start position:0% + + + + align:start position:0% + +Now I claim we can take the h over i dx + + align:start position:0% +Now I claim we can take the h over i dx + + + align:start position:0% +Now I claim we can take the h over i dx +out of this uh + + align:start position:0% +out of this uh + + + align:start position:0% +out of this uh +integral and the reason is that first is + + align:start position:0% +integral and the reason is that first is + + + align:start position:0% +integral and the reason is that first is +not an x integral it's a p integral and + + align:start position:0% +not an x integral it's a p integral and + + + align:start position:0% +not an x integral it's a p integral and +nothing else except this factor depends + + align:start position:0% +nothing else except this factor depends + + + align:start position:0% +nothing else except this factor depends +on x. So if I take it out and they want + + align:start position:0% +on x. So if I take it out and they want + + + align:start position:0% +on x. So if I take it out and they want +to bring it back, it will only act on + + align:start position:0% +to bring it back, it will only act on + + + align:start position:0% +to bring it back, it will only act on +this because this is not X + + align:start position:0% +this because this is not X + + + align:start position:0% +this because this is not X +dependent. So you should think of S. S + + align:start position:0% +dependent. So you should think of S. S + + + align:start position:0% +dependent. So you should think of S. S +doesn't have an X + + align:start position:0% +doesn't have an X + + + align:start position:0% +doesn't have an X +dependence. P S is a state and here is P + + align:start position:0% +dependence. P S is a state and here is P + + + align:start position:0% +dependence. P S is a state and here is P +doesn't have an X dependence. No, it + + align:start position:0% +doesn't have an X dependence. No, it + + + align:start position:0% +doesn't have an X dependence. No, it +does. It looks + + align:start position:0% +does. It looks + + + align:start position:0% +does. It looks +here. No, but it doesn't have it that + + align:start position:0% +here. No, but it doesn't have it that + + + align:start position:0% +here. No, but it doesn't have it that +has been + + align:start position:0% +has been + + + align:start position:0% +has been +integrated. It really doesn't have X + + align:start position:0% +integrated. It really doesn't have X + + + align:start position:0% +integrated. It really doesn't have X +dependence. So we can take this out. + + align:start position:0% +dependence. So we can take this out. + + + align:start position:0% +dependence. So we can take this out. +And we'll have h over i + + align:start position:0% +And we'll have h over i + + + align:start position:0% +And we'll have h over i +dx. And now we have + + align:start position:0% +dx. And now we have + + + align:start position:0% +dx. And now we have +dp x + + align:start position:0% + + + + align:start position:0% + +pi. And now by completeness this is just + + align:start position:0% +pi. And now by completeness this is just + + + align:start position:0% +pi. And now by completeness this is just +one. So this becomes xi. So h bar over i + + align:start position:0% +one. So this becomes xi. So h bar over i + + + align:start position:0% +one. So this becomes xi. So h bar over i +dx of + + align:start position:0% +dx of + + + align:start position:0% +dx of +xi which is what we claimed it would + + align:start position:0% + + + + align:start position:0% + +be. So + + align:start position:0% +be. So + + + align:start position:0% +be. So +uh this is rigorous rigorous derivation + + align:start position:0% +uh this is rigorous rigorous derivation + + + align:start position:0% +uh this is rigorous rigorous derivation +as you + + align:start position:0% +as you + + + align:start position:0% +as you +know there's u no guessing uh you can + + align:start position:0% +know there's u no guessing uh you can + + + align:start position:0% +know there's u no guessing uh you can +introduce complete states until you can + + align:start position:0% +introduce complete states until you can + + + align:start position:0% +introduce complete states until you can +see how things act and basically but the + + align:start position:0% +see how things act and basically but the + + + align:start position:0% +see how things act and basically but the +moral is here that you shouldn't have to + + align:start position:0% +moral is here that you shouldn't have to + + + align:start position:0% +moral is here that you shouldn't have to +go through this more than once in your + + align:start position:0% +go through this more than once in your + + + align:start position:0% +go through this more than once in your +life or practice it but once you see + + align:start position:0% +life or practice it but once you see + + + align:start position:0% +life or practice it but once you see +something like that you think you're + + align:start position:0% +something like that you think you're + + + align:start position:0% +something like that you think you're +using x representation and you're + + align:start position:0% +using x representation and you're + + + align:start position:0% +using x representation and you're +talking about the operator P. It cannot + + align:start position:0% +talking about the operator P. It cannot + + + align:start position:0% +talking about the operator P. It cannot +be anything like that. If you want to + + align:start position:0% +be anything like that. If you want to + + + align:start position:0% +be anything like that. If you want to +practice something different, show that + + align:start position:0% +practice something different, show that + + + align:start position:0% +practice something different, show that +the analog P Xhat pi is equal I H bar + + align:start position:0% +the analog P Xhat pi is equal I H bar + + + align:start position:0% +the analog P Xhat pi is equal I H bar +DDP of PI tilda of P. So it's the + + align:start position:0% +DDP of PI tilda of P. So it's the + + + align:start position:0% +DDP of PI tilda of P. So it's the +opposite relation. + + align:start position:0% + + + + align:start position:0% + +All right, questions. + + align:start position:0% + + + + align:start position:0% + +Yes. So, how is one supposed to? So, + + align:start position:0% +Yes. So, how is one supposed to? So, + + + align:start position:0% +Yes. So, how is one supposed to? So, +what it appears is happening is you're + + align:start position:0% +what it appears is happening is you're + + + align:start position:0% +what it appears is happening is you're +basically taking some state like S and + + align:start position:0% +basically taking some state like S and + + + align:start position:0% +basically taking some state like S and +you're basically writing in terms of + + align:start position:0% +you're basically writing in terms of + + + align:start position:0% +you're basically writing in terms of +some basis, correct? And then you're + + align:start position:0% +some basis, correct? And then you're + + + align:start position:0% +some basis, correct? And then you're +basically using the L2 norm on the + + align:start position:0% +basically using the L2 norm on the + + + align:start position:0% +basically using the L2 norm on the +coordinates of this thing. But the + + align:start position:0% +coordinates of this thing. But the + + + align:start position:0% +coordinates of this thing. But the +question is what does the this basis + + align:start position:0% +question is what does the this basis + + + align:start position:0% +question is what does the this basis +actually look like? Like what are these + + align:start position:0% +actually look like? Like what are these + + + align:start position:0% +actually look like? Like what are these +vectors? Because if you put them in + + align:start position:0% +vectors? Because if you put them in + + + align:start position:0% +vectors? Because if you put them in +their own coordinates, they're just + + align:start position:0% +their own coordinates, they're just + + + align:start position:0% +their own coordinates, they're just +infinite. Yeah, they're not even delta. + + align:start position:0% +infinite. Yeah, they're not even delta. + + + align:start position:0% +infinite. Yeah, they're not even delta. +I mean, they are delta functions. Uh + + align:start position:0% +I mean, they are delta functions. Uh + + + align:start position:0% +I mean, they are delta functions. Uh +these vectors are delta functions + + align:start position:0% +these vectors are delta functions + + + align:start position:0% +these vectors are delta functions +because if you have a state that has + + align:start position:0% +because if you have a state that has + + + align:start position:0% +because if you have a state that has +this as the position state of a + + align:start position:0% +this as the position state of a + + + align:start position:0% +this as the position state of a +particle, you find the wave function by + + align:start position:0% +particle, you find the wave function by + + + align:start position:0% +particle, you find the wave function by +doing x on it. That's our definition of + + align:start position:0% +doing x on it. That's our definition of + + + align:start position:0% +doing x on it. That's our definition of +a wave function. And it's uh infinite. + + align:start position:0% +a wave function. And it's uh infinite. + + + align:start position:0% +a wave function. And it's uh infinite. +So + + align:start position:0% +So + + + align:start position:0% +So +uh you know it's there's not too much + + align:start position:0% +uh you know it's there's not too much + + + align:start position:0% +uh you know it's there's not too much +one can say about this. You know if + + align:start position:0% +one can say about this. You know if + + + align:start position:0% +one can say about this. You know if +people want to work more ma + + align:start position:0% +people want to work more ma + + + align:start position:0% +people want to work more ma +mathematically in a more comfortable way + + align:start position:0% +mathematically in a more comfortable way + + + align:start position:0% +mathematically in a more comfortable way +what you do is instead of taking + + align:start position:0% +what you do is instead of taking + + + align:start position:0% +what you do is instead of taking +infinite things you put everything on a + + align:start position:0% +infinite things you put everything on a + + + align:start position:0% +infinite things you put everything on a +big circle and then you have a furious + + align:start position:0% +big circle and then you have a furious + + + align:start position:0% +big circle and then you have a furious +series and the transform is sums and + + align:start position:0% +series and the transform is sums and + + + align:start position:0% +series and the transform is sums and +everything goes into sums but there's no + + align:start position:0% +everything goes into sums but there's no + + + align:start position:0% +everything goes into sums but there's no +real need. These operations are safe and + + align:start position:0% +real need. These operations are safe and + + + align:start position:0% +real need. These operations are safe and +uh we managed to do them and we're okay + + align:start position:0% +uh we managed to do them and we're okay + + + align:start position:0% +uh we managed to do them and we're okay +with them. + + align:start position:0% +with them. + + + align:start position:0% +with them. +Other + + align:start position:0% +Other + + + align:start position:0% +Other +questions? Yes. + + align:start position:0% +questions? Yes. + + + align:start position:0% +questions? Yes. +So infinite + + align:start position:0% +So infinite + + + align:start position:0% +So infinite +basis are these rules for any + + align:start position:0% +basis are these rules for any + + + align:start position:0% +basis are these rules for any +probably not. You know infinite bases + + align:start position:0% +probably not. You know infinite bases + + + align:start position:0% +probably not. You know infinite bases +are delicate. Um you know Hilbert spaces + + align:start position:0% +are delicate. Um you know Hilbert spaces + + + align:start position:0% +are delicate. Um you know Hilbert spaces +are infinite dimensional vector spaces + + align:start position:0% +are infinite dimensional vector spaces + + + align:start position:0% +are infinite dimensional vector spaces +and uh they not every infinite + + align:start position:0% +and uh they not every infinite + + + align:start position:0% +and uh they not every infinite +dimensional space is a Hilbert space. + + align:start position:0% +dimensional space is a Hilbert space. + + + align:start position:0% +dimensional space is a Hilbert space. +Not you know the most important thing of + + align:start position:0% +Not you know the most important thing of + + + align:start position:0% +Not you know the most important thing of +a Hilbert space is this norm this inner + + align:start position:0% +a Hilbert space is this norm this inner + + + align:start position:0% +a Hilbert space is this norm this inner +product but um the other important thing + + align:start position:0% +product but um the other important thing + + + align:start position:0% +product but um the other important thing +is some convergence facts about + + align:start position:0% +is some convergence facts about + + + align:start position:0% +is some convergence facts about +sequences of vectors that converge to + + align:start position:0% +sequences of vectors that converge to + + + align:start position:0% +sequences of vectors that converge to +points that are on the space. So it's + + align:start position:0% +points that are on the space. So it's + + + align:start position:0% +points that are on the space. So it's +delicate. Infinite dimensional spaces + + align:start position:0% +delicate. Infinite dimensional spaces + + + align:start position:0% +delicate. Infinite dimensional spaces +can be pretty bad. A banana space is not + + align:start position:0% +can be pretty bad. A banana space is not + + + align:start position:0% +can be pretty bad. A banana space is not +a Hilbert space and it's more comp + + align:start position:0% +a Hilbert space and it's more comp + + + align:start position:0% +a Hilbert space and it's more comp +only for Hilbert spaces. and and + + align:start position:0% +only for Hilbert spaces. and and + + + align:start position:0% +only for Hilbert spaces. and and +basically you + + align:start position:0% +basically you + + + align:start position:0% +basically you +know this this problem of a particle on + + align:start position:0% +know this this problem of a particle on + + + align:start position:0% +know this this problem of a particle on +a line or a particle in three space is + + align:start position:0% +a line or a particle in three space is + + + align:start position:0% +a line or a particle in three space is +sufficiently well known that we're + + align:start position:0% +sufficiently well known that we're + + + align:start position:0% +sufficiently well known that we're +totally comfortable with this somewhat + + align:start position:0% +totally comfortable with this somewhat + + + align:start position:0% +totally comfortable with this somewhat +uh singular operations. So the operator + + align:start position:0% +uh singular operations. So the operator + + + align:start position:0% +uh singular operations. So the operator +X or the operator P may not be what + + align:start position:0% +X or the operator P may not be what + + + align:start position:0% +X or the operator P may not be what +mathematicians like them to be bounded + + align:start position:0% +mathematicians like them to be bounded + + + align:start position:0% +mathematicians like them to be bounded +operators and Hbert spaces but but we + + align:start position:0% +operators and Hbert spaces but but we + + + align:start position:0% +operators and Hbert spaces but but we +know how to not to make mistakes with + + align:start position:0% +know how to not to make mistakes with + + + align:start position:0% +know how to not to make mistakes with +them. And uh if you have a very subtle + + align:start position:0% +them. And uh if you have a very subtle + + + align:start position:0% +them. And uh if you have a very subtle +problem one day you probably have to be + + align:start position:0% +problem one day you probably have to be + + + align:start position:0% +problem one day you probably have to be +more careful but for the problems we're + + align:start position:0% +more careful but for the problems we're + + + align:start position:0% +more careful but for the problems we're +interested now we don't. + + align:start position:0% + + + + align:start position:0% + +So, our last topic today um is + + align:start position:0% +So, our last topic today um is + + + align:start position:0% +So, our last topic today um is +uncertainties and uncertainty relations. + + align:start position:0% +uncertainties and uncertainty relations. + + + align:start position:0% +uncertainties and uncertainty relations. +Um I probably won't get through all of + + align:start position:0% +Um I probably won't get through all of + + + align:start position:0% +Um I probably won't get through all of +it, but um we'll get + + align:start position:0% +it, but um we'll get + + + align:start position:0% +it, but um we'll get +started and + + align:start position:0% + + + + align:start position:0% + +um and so we'll have + + align:start position:0% + + + + align:start position:0% + +uncertainties. + + align:start position:0% +uncertainties. + + + align:start position:0% +uncertainties. +necessarily + + align:start position:0% + + + + align:start position:0% + +these and uh we will talk about + + align:start position:0% +these and uh we will talk about + + + align:start position:0% +these and uh we will talk about +operators and uh permission operators. + + align:start position:0% +operators and uh permission operators. + + + align:start position:0% +operators and uh permission operators. +So here is the question basically if you + + align:start position:0% +So here is the question basically if you + + + align:start position:0% +So here is the question basically if you +have a + + align:start position:0% +have a + + + align:start position:0% +have a +state we know the result of a + + align:start position:0% +state we know the result of a + + + align:start position:0% +state we know the result of a +measurement of an observable is the + + align:start position:0% +measurement of an observable is the + + + align:start position:0% +measurement of an observable is the +value of a hermission operator. + + align:start position:0% +value of a hermission operator. + + + align:start position:0% +value of a hermission operator. +Now if the state is an iggon state of + + align:start position:0% +Now if the state is an iggon state of + + + align:start position:0% +Now if the state is an iggon state of +the hermission operator, you measure the + + align:start position:0% +the hermission operator, you measure the + + + align:start position:0% +the hermission operator, you measure the +observable and out comes the iggon + + align:start position:0% +observable and out comes the iggon + + + align:start position:0% +observable and out comes the iggon +value and there's no uncertainty in the + + align:start position:0% +value and there's no uncertainty in the + + + align:start position:0% +value and there's no uncertainty in the +measured observable because the measured + + align:start position:0% +measured observable because the measured + + + align:start position:0% +measured observable because the measured +observable is an igon value and the + + align:start position:0% +observable is an igon value and the + + + align:start position:0% +observable is an igon value and the +state is an iggon state. + + align:start position:0% +state is an iggon state. + + + align:start position:0% +state is an iggon state. +The problem arises when the state that + + align:start position:0% +The problem arises when the state that + + + align:start position:0% +The problem arises when the state that +you're trying to measure this property + + align:start position:0% +you're trying to measure this property + + + align:start position:0% +you're trying to measure this property +is not an iggon state of the + + align:start position:0% +is not an iggon state of the + + + align:start position:0% +is not an iggon state of the +observable. So you know that the + + align:start position:0% +observable. So you know that the + + + align:start position:0% +observable. So you know that the +interpretation of quantum mechanics is + + align:start position:0% +interpretation of quantum mechanics is + + + align:start position:0% +interpretation of quantum mechanics is +there's a probabilistic distribution. + + align:start position:0% +there's a probabilistic distribution. + + + align:start position:0% +there's a probabilistic distribution. +You sometimes get one thing, sometimes + + align:start position:0% +You sometimes get one thing, sometimes + + + align:start position:0% +You sometimes get one thing, sometimes +get another thing depending on the + + align:start position:0% +get another thing depending on the + + + align:start position:0% +get another thing depending on the +amplitudes of the states to be in in + + align:start position:0% +amplitudes of the states to be in in + + + align:start position:0% +amplitudes of the states to be in in +those particular states. But there's an + + align:start position:0% +those particular states. But there's an + + + align:start position:0% +those particular states. But there's an +uncertainty at this time. you don't know + + align:start position:0% +uncertainty at this time. you don't know + + + align:start position:0% +uncertainty at this time. you don't know +what the measured value will + + align:start position:0% +what the measured value will + + + align:start position:0% +what the measured value will +be. So we'll define the uncertainty + + align:start position:0% +be. So we'll define the uncertainty + + + align:start position:0% +be. So we'll define the uncertainty +associated to a hermission + + align:start position:0% +associated to a hermission + + + align:start position:0% +associated to a hermission +operator and uh we want to define this + + align:start position:0% +operator and uh we want to define this + + + align:start position:0% +operator and uh we want to define this +answer. So a will be a hermission + + align:start position:0% + + + + align:start position:0% + +operator + + align:start position:0% + + + + align:start position:0% + +operator and you were talking about the + + align:start position:0% +operator and you were talking about the + + + align:start position:0% +operator and you were talking about the +uncertainty. Now the uncertainty of that + + align:start position:0% +uncertainty. Now the uncertainty of that + + + align:start position:0% +uncertainty. Now the uncertainty of that +operator the first thing that you should + + align:start position:0% +operator the first thing that you should + + + align:start position:0% +operator the first thing that you should +remember is you cannot talk about the + + align:start position:0% +remember is you cannot talk about the + + + align:start position:0% +remember is you cannot talk about the +uncertainty of the operator unless you + + align:start position:0% +uncertainty of the operator unless you + + + align:start position:0% +uncertainty of the operator unless you +give me a state. So all the formulas + + align:start position:0% +give me a state. So all the formulas + + + align:start position:0% +give me a state. So all the formulas +we're going to write for uncertainties + + align:start position:0% +we're going to write for uncertainties + + + align:start position:0% +we're going to write for uncertainties +are uncertainties of operators in some + + align:start position:0% +are uncertainties of operators in some + + + align:start position:0% +are uncertainties of operators in some +state. So let's call the + + align:start position:0% +state. So let's call the + + + align:start position:0% +state. So let's call the +state + + align:start position:0% + + + + align:start position:0% + +s and time will not be relevant. So + + align:start position:0% +s and time will not be relevant. So + + + align:start position:0% +s and time will not be relevant. So +maybe I should delete the the well the + + align:start position:0% +maybe I should delete the the well the + + + align:start position:0% +maybe I should delete the the well the +I'll leave that bar there um just in + + align:start position:0% +I'll leave that bar there um just in + + + align:start position:0% +I'll leave that bar there um just in +case. + + align:start position:0% +case. + + + align:start position:0% +case. +So we're going to try to define + + align:start position:0% +So we're going to try to define + + + align:start position:0% +So we're going to try to define +uncertainty. But uh before we do that, + + align:start position:0% +uncertainty. But uh before we do that, + + + align:start position:0% +uncertainty. But uh before we do that, +let's try to define another thing. The + + align:start position:0% +let's try to define another thing. The + + + align:start position:0% +let's try to define another thing. The +expectation value. Well, the expectation + + align:start position:0% +expectation value. Well, the expectation + + + align:start position:0% +expectation value. Well, the expectation +value, you know it, the expectation + + align:start position:0% +value, you know it, the expectation + + + align:start position:0% +value, you know it, the expectation +value of a. And you could put a pi here + + align:start position:0% +value of a. And you could put a pi here + + + align:start position:0% +value of a. And you could put a pi here +if you wish to remind you that it + + align:start position:0% +if you wish to remind you that it + + + align:start position:0% +if you wish to remind you that it +depends on on the state is well + + align:start position:0% +depends on on the state is well + + + align:start position:0% +depends on on the state is well +pi + + align:start position:0% +pi + + + align:start position:0% +pi +api that's what we call expectation + + align:start position:0% +api that's what we call expectation + + + align:start position:0% +api that's what we call expectation +value in the inner product notation + + align:start position:0% +value in the inner product notation + + + align:start position:0% +value in the inner product notation +would be + + align:start position:0% +would be + + + align:start position:0% +would be +pi + + align:start position:0% + + + + align:start position:0% + +apai and one thing you know that this + + align:start position:0% +apai and one thing you know that this + + + align:start position:0% +apai and one thing you know that this +thing is + + align:start position:0% +thing is + + + align:start position:0% +thing is +real because + + align:start position:0% +real because + + + align:start position:0% +real because +the expectation values of permission + + align:start position:0% +the expectation values of permission + + + align:start position:0% +the expectation values of permission +operators is real. That's something we + + align:start position:0% +operators is real. That's something we + + + align:start position:0% +operators is real. That's something we +reviewed at the beginning of the lecture + + align:start position:0% +reviewed at the beginning of the lecture + + + align:start position:0% +reviewed at the beginning of the lecture +today. + + align:start position:0% +today. + + + align:start position:0% +today. +So now comes the question + + align:start position:0% +So now comes the question + + + align:start position:0% +So now comes the question +um what can I do to define an + + align:start position:0% +um what can I do to define an + + + align:start position:0% +um what can I do to define an +uncertainty of an operator and an + + align:start position:0% +uncertainty of an operator and an + + + align:start position:0% +uncertainty of an operator and an +uncertainty now we've said already + + align:start position:0% +uncertainty now we've said already + + + align:start position:0% +uncertainty now we've said already +something I wish to define an + + align:start position:0% +something I wish to define an + + + align:start position:0% +something I wish to define an +uncertainty that is such that the + + align:start position:0% +uncertainty that is such that the + + + align:start position:0% +uncertainty that is such that the +uncertainty is zero if the + + align:start position:0% +uncertainty is zero if the + + + align:start position:0% +uncertainty is zero if the +operator if the state is an iggon state + + align:start position:0% +operator if the state is an iggon state + + + align:start position:0% +operator if the state is an iggon state +and the uncertainty is different from + + align:start position:0% +and the uncertainty is different from + + + align:start position:0% +and the uncertainty is different from +zero if it's not an igen state. In fact, + + align:start position:0% +zero if it's not an igen state. In fact, + + + align:start position:0% +zero if it's not an igen state. In fact, +I wish that the uncertainty is zero if + + align:start position:0% +I wish that the uncertainty is zero if + + + align:start position:0% +I wish that the uncertainty is zero if +and only if the state is an iggon state. + + align:start position:0% +and only if the state is an iggon state. + + + align:start position:0% +and only if the state is an iggon state. +So actually we can achieve that and + + align:start position:0% +So actually we can achieve that and + + + align:start position:0% +So actually we can achieve that and +uh and we sort of in some sense I think + + align:start position:0% +uh and we sort of in some sense I think + + + align:start position:0% +uh and we sort of in some sense I think +the most intuitive + + align:start position:0% +the most intuitive + + + align:start position:0% +the most intuitive +definition is the one + + align:start position:0% +definition is the one + + + align:start position:0% +definition is the one +that I will show here is that we define + + align:start position:0% +that I will show here is that we define + + + align:start position:0% +that I will show here is that we define +the uncertainty delta a and I'll put the + + align:start position:0% +the uncertainty delta a and I'll put the + + + align:start position:0% +the uncertainty delta a and I'll put the +pi here. So this is called the + + align:start position:0% +pi here. So this is called the + + + align:start position:0% +pi here. So this is called the +uncertainty + + align:start position:0% + + + + align:start position:0% + +of + + align:start position:0% +of + + + align:start position:0% +of +a in the state + + align:start position:0% + + + + align:start position:0% + +p. So we'll define it a simple way. What + + align:start position:0% +p. So we'll define it a simple way. What + + + align:start position:0% +p. So we'll define it a simple way. What +else do we want? We + + align:start position:0% +else do we want? We + + + align:start position:0% +else do we want? We +said this should be zero if and only if + + align:start position:0% +said this should be zero if and only if + + + align:start position:0% +said this should be zero if and only if +the state is an iggon + + align:start position:0% +the state is an iggon + + + align:start position:0% +the state is an iggon +state. Second I want this thing to be a + + align:start position:0% +state. Second I want this thing to be a + + + align:start position:0% +state. Second I want this thing to be a +real number. + + align:start position:0% +real number. + + + align:start position:0% +real number. +in fact a positive + + align:start position:0% +in fact a positive + + + align:start position:0% +in fact a positive +number. What function do we + + align:start position:0% +number. What function do we + + + align:start position:0% +number. What function do we +know in quantum mechanics that can do + + align:start position:0% +know in quantum mechanics that can do + + + align:start position:0% +know in quantum mechanics that can do +that magic? Well, it's a norm. The norm + + align:start position:0% +that magic? Well, it's a norm. The norm + + + align:start position:0% +that magic? Well, it's a norm. The norm +function is always real and positive. So + + align:start position:0% +function is always real and positive. So + + + align:start position:0% +function is always real and positive. So +this will try to set it equal to a norm. + + align:start position:0% +this will try to set it equal to a norm. + + + align:start position:0% +this will try to set it equal to a norm. +So claim is the norm of the state a + + align:start position:0% +So claim is the norm of the state a + + + align:start position:0% +So claim is the norm of the state a +minus expectation value of a * + + align:start position:0% +minus expectation value of a * + + + align:start position:0% +minus expectation value of a * +1 acting on + + align:start position:0% +1 acting on + + + align:start position:0% +1 acting on +s. This will be our + + align:start position:0% +s. This will be our + + + align:start position:0% +s. This will be our +definition of the + + align:start position:0% + + + + align:start position:0% + +uncertainty. So it's the norm of this + + align:start position:0% +uncertainty. So it's the norm of this + + + align:start position:0% +uncertainty. So it's the norm of this +vector. + + align:start position:0% + + + + align:start position:0% + +Now let's look at this uh suppose the + + align:start position:0% +Now let's look at this uh suppose the + + + align:start position:0% +Now let's look at this uh suppose the +norm + + align:start position:0% + + + + align:start position:0% + +uncertainty is + + align:start position:0% + + + + align:start position:0% + +zero and if the uncertainty is zero this + + align:start position:0% +zero and if the uncertainty is zero this + + + align:start position:0% +zero and if the uncertainty is zero this +vector must be zero. So + + align:start position:0% +vector must be zero. So + + + align:start position:0% +vector must be zero. So +a minus expectation value of + + align:start position:0% +a minus expectation value of + + + align:start position:0% +a minus expectation value of +a on + + align:start position:0% +a on + + + align:start position:0% +a on +s is zero + + align:start position:0% +s is zero + + + align:start position:0% +s is zero +or + + align:start position:0% +or + + + align:start position:0% +or +a + + align:start position:0% +a + + + align:start position:0% +a +pi is equal to expectation value of a on + + align:start position:0% +pi is equal to expectation value of a on + + + align:start position:0% +pi is equal to expectation value of a on +pi. The one doesn't do much. Many people + + align:start position:0% +pi. The one doesn't do much. Many people + + + align:start position:0% +pi. The one doesn't do much. Many people +don't write the one. I could get tired + + align:start position:0% +don't write the one. I could get tired + + + align:start position:0% +don't write the one. I could get tired +and stop writing it. uh you should um + + align:start position:0% +and stop writing it. uh you should um + + + align:start position:0% +and stop writing it. uh you should um +probably it's good manners to write the + + align:start position:0% +probably it's good manners to write the + + + align:start position:0% +probably it's good manners to write the +I but uh it's not all that necessary. + + align:start position:0% +I but uh it's not all that necessary. + + + align:start position:0% +I but uh it's not all that necessary. +You don't get that confused. If there's + + align:start position:0% +You don't get that confused. If there's + + + align:start position:0% +You don't get that confused. If there's +an operator and uh a number here, there + + align:start position:0% +an operator and uh a number here, there + + + align:start position:0% +an operator and uh a number here, there +must be a identity matrix. So if the + + align:start position:0% +must be a identity matrix. So if the + + + align:start position:0% +must be a identity matrix. So if the +uncertainty is zero, the vector is zero + + align:start position:0% +uncertainty is zero, the vector is zero + + + align:start position:0% +uncertainty is zero, the vector is zero +and this is true. Now you say well this + + align:start position:0% +and this is true. Now you say well this + + + align:start position:0% +and this is true. Now you say well this +equation looks kind of funny but it's it + + align:start position:0% +equation looks kind of funny but it's it + + + align:start position:0% +equation looks kind of funny but it's it +says that pi is an igen state of a + + align:start position:0% +says that pi is an igen state of a + + + align:start position:0% +says that pi is an igen state of a +because this is a + + align:start position:0% +because this is a + + + align:start position:0% +because this is a +number you know it looks a little funny + + align:start position:0% +number you know it looks a little funny + + + align:start position:0% +number you know it looks a little funny +because we're accustom a pi lambda pi + + align:start position:0% +because we're accustom a pi lambda pi + + + align:start position:0% +because we're accustom a pi lambda pi +but this is a number and in fact let me + + align:start position:0% +but this is a number and in fact let me + + + align:start position:0% +but this is a number and in fact let me +show you one thing if you have a pi + + align:start position:0% +show you one thing if you have a pi + + + align:start position:0% +show you one thing if you have a pi +equal lambda + + align:start position:0% +equal lambda + + + align:start position:0% +equal lambda +pi oh I should say here that pi is + + align:start position:0% + + + + align:start position:0% + +normalized. You know if pi would not be + + align:start position:0% +normalized. You know if pi would not be + + + align:start position:0% +normalized. You know if pi would not be +normalize you change the normalization + + align:start position:0% +normalize you change the normalization + + + align:start position:0% +normalize you change the normalization +you change the uh uncertainty. So it + + align:start position:0% +you change the uh uncertainty. So it + + + align:start position:0% +you change the uh uncertainty. So it +should be + + align:start position:0% +should be + + + align:start position:0% +should be +normalized. And look at this. If you + + align:start position:0% +normalized. And look at this. If you + + + align:start position:0% +normalized. And look at this. If you +have a pi equal + + align:start position:0% +have a pi equal + + + align:start position:0% +have a pi equal +lambda, do the inner product with a + + align:start position:0% +lambda, do the inner product with a + + + align:start position:0% +lambda, do the inner product with a +um no do the inner product with pi + + align:start position:0% +um no do the inner product with pi + + + align:start position:0% +um no do the inner product with pi +s, a + + align:start position:0% +s, a + + + align:start position:0% +s, a +pi would be equal to lambda because pi + + align:start position:0% +pi would be equal to lambda because pi + + + align:start position:0% +pi would be equal to lambda because pi +inner product with pi is one. But what + + align:start position:0% +inner product with pi is one. But what + + + align:start position:0% +inner product with pi is one. But what +is this? This is the expectation value + + align:start position:0% +is this? This is the expectation value + + + align:start position:0% +is this? This is the expectation value +of a. + + align:start position:0% +of a. + + + align:start position:0% +of a. +So, so actually given our definition + + align:start position:0% +So, so actually given our definition + + + align:start position:0% +So, so actually given our definition +the value of some operator uh on the + + align:start position:0% +the value of some operator uh on the + + + align:start position:0% +the value of some operator uh on the +state is the expectation value of the + + align:start position:0% +state is the expectation value of the + + + align:start position:0% +state is the expectation value of the +operator in the state. So back to the + + align:start position:0% +operator in the state. So back to the + + + align:start position:0% +operator in the state. So back to the +argument if the uncertainty is + + align:start position:0% +argument if the uncertainty is + + + align:start position:0% +argument if the uncertainty is +zero the state is an + + align:start position:0% +zero the state is an + + + align:start position:0% +zero the state is an +enig value happens to be the expectation + + align:start position:0% +enig value happens to be the expectation + + + align:start position:0% +enig value happens to be the expectation +value that is if the uncertainty is + + align:start position:0% +value that is if the uncertainty is + + + align:start position:0% +value that is if the uncertainty is +zero. On the other hand, if you're in an + + align:start position:0% +zero. On the other hand, if you're in an + + + align:start position:0% +zero. On the other hand, if you're in an +igen state, you're here, then lambda is + + align:start position:0% +igen state, you're here, then lambda is + + + align:start position:0% +igen state, you're here, then lambda is +a and this equation shows that this + + align:start position:0% +a and this equation shows that this + + + align:start position:0% +a and this equation shows that this +vector is zero and therefore you get + + align:start position:0% +vector is zero and therefore you get + + + align:start position:0% +vector is zero and therefore you get +zero. So you've shown that this expecta + + align:start position:0% +zero. So you've shown that this expecta + + + align:start position:0% +zero. So you've shown that this expecta +this norm or this uncertainty is zero if + + align:start position:0% +this norm or this uncertainty is zero if + + + align:start position:0% +this norm or this uncertainty is zero if +and only if the state is an igen state. + + align:start position:0% +and only if the state is an igen state. + + + align:start position:0% +and only if the state is an igen state. +And that's a very powerful statement. + + align:start position:0% +And that's a very powerful statement. + + + align:start position:0% +And that's a very powerful statement. +the the statement that is always known + + align:start position:0% +the the statement that is always known + + + align:start position:0% +the the statement that is always known +by everybody is that um if you have an + + align:start position:0% +by everybody is that um if you have an + + + align:start position:0% +by everybody is that um if you have an +iggon state yes no uncertainty but if + + align:start position:0% +iggon state yes no uncertainty but if + + + align:start position:0% +iggon state yes no uncertainty but if +there's no uncertainty you must have an + + align:start position:0% +there's no uncertainty you must have an + + + align:start position:0% +there's no uncertainty you must have an +iggon state that's the second part and + + align:start position:0% +iggon state that's the second part and + + + align:start position:0% +iggon state that's the second part and +uses the fact that the only vector with + + align:start position:0% +uses the fact that the only vector with + + + align:start position:0% +uses the fact that the only vector with +zero norm is the zero vector a thing + + align:start position:0% +zero norm is the zero vector a thing + + + align:start position:0% +zero norm is the zero vector a thing +that we use over and over again. So let + + align:start position:0% +that we use over and over again. So let + + + align:start position:0% +that we use over and over again. So let +me make + + align:start position:0% +me make + + + align:start position:0% +me make +um couple more comments on how you + + align:start position:0% +um couple more comments on how you + + + align:start position:0% +um couple more comments on how you +compute this. + + align:start position:0% +compute this. + + + align:start position:0% +compute this. +Um so that's the + + align:start position:0% +Um so that's the + + + align:start position:0% +Um so that's the +uncertainty so + + align:start position:0% + + + + align:start position:0% + +far. So the uncertainty vanishes in that + + align:start position:0% +far. So the uncertainty vanishes in that + + + align:start position:0% +far. So the uncertainty vanishes in that +case. Now we can square this equation to + + align:start position:0% +case. Now we can square this equation to + + + align:start position:0% +case. Now we can square this equation to +find a + + align:start position:0% +find a + + + align:start position:0% +find a +formula that is perhaps more familiar + + align:start position:0% +formula that is perhaps more familiar + + + align:start position:0% +formula that is perhaps more familiar +not necessarily more useful but also + + align:start position:0% +not necessarily more useful but also + + + align:start position:0% +not necessarily more useful but also +good for computations is pretty good. + + align:start position:0% +good for computations is pretty good. + + + align:start position:0% +good for computations is pretty good. +Delta a of pi which is real we square + + align:start position:0% +Delta a of pi which is real we square + + + align:start position:0% +Delta a of pi which is real we square +it. Well, the norm square is the inner + + align:start position:0% +it. Well, the norm square is the inner + + + align:start position:0% +it. Well, the norm square is the inner +product of this a + + align:start position:0% +product of this a + + + align:start position:0% +product of this a +- + + align:start position:0% + + + + align:start position:0% + +a + + align:start position:0% +a + + + align:start position:0% +a +s a - + + align:start position:0% + + + + align:start position:0% + +a + + align:start position:0% +a + + + align:start position:0% +a +s norm squared is the inner product of + + align:start position:0% +s norm squared is the inner product of + + + align:start position:0% +s norm squared is the inner product of +these two vectors. Now the thing that we + + align:start position:0% +these two vectors. Now the thing that we + + + align:start position:0% +these two vectors. Now the thing that we +like to do is to move this factor to + + align:start position:0% +like to do is to move this factor to + + + align:start position:0% +like to do is to move this factor to +that + + align:start position:0% +that + + + align:start position:0% +that +side. How do you move a factor on the + + align:start position:0% +side. How do you move a factor on the + + + align:start position:0% +side. How do you move a factor on the +first input to the other input? You take + + align:start position:0% +first input to the other input? You take + + + align:start position:0% +first input to the other input? You take +the adjint. So I should move it with an + + align:start position:0% +the adjint. So I should move it with an + + + align:start position:0% +the adjint. So I should move it with an +adjint. So what do I get? + + align:start position:0% +adjint. So what do I get? + + + align:start position:0% +adjint. So what do I get? +S and then I get the + + align:start position:0% + + + + align:start position:0% + +adjint and this factor + + align:start position:0% + + + + align:start position:0% + +again. Now I should put a dagger + + align:start position:0% +again. Now I should put a dagger + + + align:start position:0% +again. Now I should put a dagger +here but let me not put it because a is + + align:start position:0% +here but let me not put it because a is + + + align:start position:0% +here but let me not put it because a is +her + + align:start position:0% +her + + + align:start position:0% +her +mission and + + align:start position:0% +mission and + + + align:start position:0% +mission and +moreover expectation value of a is + + align:start position:0% +moreover expectation value of a is + + + align:start position:0% +moreover expectation value of a is +real her. So no need for the dagger. So + + align:start position:0% +real her. So no need for the dagger. So + + + align:start position:0% +real her. So no need for the dagger. So +you can put the dagger and then explain + + align:start position:0% +you can put the dagger and then explain + + + align:start position:0% +you can put the dagger and then explain +that this is her mission and this is + + align:start position:0% +that this is her mission and this is + + + align:start position:0% +that this is her mission and this is +real or just not put + + align:start position:0% +real or just not put + + + align:start position:0% +real or just not put +it. And now look at this. This is a + + align:start position:0% +it. And now look at this. This is a + + + align:start position:0% +it. And now look at this. This is a +typical calculation. You'll do it many + + align:start position:0% +typical calculation. You'll do it many + + + align:start position:0% +typical calculation. You'll do it many +many + + align:start position:0% +many + + + align:start position:0% +many +times. You just spread out the things. + + align:start position:0% +times. You just spread out the things. + + + align:start position:0% +times. You just spread out the things. +So let me just do it once. U here you + + align:start position:0% +So let me just do it once. U here you + + + align:start position:0% +So let me just do it once. U here you +get a squared minus a expectation value + + align:start position:0% +get a squared minus a expectation value + + + align:start position:0% +get a squared minus a expectation value +of a minus expectation value of a + + align:start position:0% +of a minus expectation value of a + + + align:start position:0% +of a minus expectation value of a +a plus expectation value of a squared. + + align:start position:0% + + + + align:start position:0% + +Sigh. So I multiplied everything but you + + align:start position:0% +Sigh. So I multiplied everything but you + + + align:start position:0% +Sigh. So I multiplied everything but you +shouldn't be all that. I should put a + + align:start position:0% +shouldn't be all that. I should put a + + + align:start position:0% +shouldn't be all that. I should put a +one here probably. + + align:start position:0% +one here probably. + + + align:start position:0% +one here probably. +Um shouldn't worry about this much. This + + align:start position:0% +Um shouldn't worry about this much. This + + + align:start position:0% +Um shouldn't worry about this much. This +is a number and an a number and an a. + + align:start position:0% +is a number and an a number and an a. + + + align:start position:0% +is a number and an a number and an a. +The order doesn't matter. These two + + align:start position:0% +The order doesn't matter. These two + + + align:start position:0% +The order doesn't matter. These two +terms are really the + + align:start position:0% +terms are really the + + + align:start position:0% +terms are really the +same. Well let me go slowly on this + + align:start position:0% +same. Well let me go slowly on this + + + align:start position:0% +same. Well let me go slowly on this +once. Um what is the first term? It's pi + + align:start position:0% +once. Um what is the first term? It's pi + + + align:start position:0% +once. Um what is the first term? It's pi +a^2 pi. So it's the expectation value of + + align:start position:0% +a^2 pi. So it's the expectation value of + + + align:start position:0% +a^2 pi. So it's the expectation value of +a + + align:start position:0% +a + + + align:start position:0% +a +squared. Now what is this term? Well, + + align:start position:0% +squared. Now what is this term? Well, + + + align:start position:0% +squared. Now what is this term? Well, +you have a number here which is real + + align:start position:0% +you have a number here which is real + + + align:start position:0% +you have a number here which is real +goes out of whatever you're doing and + + align:start position:0% +goes out of whatever you're doing and + + + align:start position:0% +goes out of whatever you're doing and +you have pi api. So this is expectation + + align:start position:0% +you have pi api. So this is expectation + + + align:start position:0% +you have pi api. So this is expectation +value of a and from the leftover pi api + + align:start position:0% +value of a and from the leftover pi api + + + align:start position:0% +value of a and from the leftover pi api +you get another expectation value of a. + + align:start position:0% +you get another expectation value of a. + + + align:start position:0% +you get another expectation value of a. +So this is a + + align:start position:0% + + + + align:start position:0% + +a here the same thing the number goes + + align:start position:0% +a here the same thing the number goes + + + align:start position:0% +a here the same thing the number goes +out and you're left with a pi a pi which + + align:start position:0% +out and you're left with a pi a pi which + + + align:start position:0% +out and you're left with a pi a pi which +is another expectation value of a so you + + align:start position:0% +is another expectation value of a so you + + + align:start position:0% +is another expectation value of a so you +get minus + + align:start position:0% +get minus + + + align:start position:0% +get minus +a + + align:start position:0% +a + + + align:start position:0% +a +a and you have a plus expectation value + + align:start position:0% +a and you have a plus expectation value + + + align:start position:0% +a and you have a plus expectation value +of a squared and I don't need the i + + align:start position:0% +of a squared and I don't need the i + + + align:start position:0% +of a squared and I don't need the i +anymore because uh the expectation + + align:start position:0% +anymore because uh the expectation + + + align:start position:0% +anymore because uh the expectation +values have been taken and this always + + align:start position:0% +values have been taken and this always + + + align:start position:0% +values have been taken and this always +happens And there's a minus here, a + + align:start position:0% +happens And there's a minus here, a + + + align:start position:0% +happens And there's a minus here, a +minus here, and a plus here. So there's + + align:start position:0% +minus here, and a plus here. So there's + + + align:start position:0% +minus here, and a plus here. So there's +just one minus at the end of the + + align:start position:0% + + + + align:start position:0% + +day. One minus at the end of the day. + + align:start position:0% +day. One minus at the end of the day. + + + align:start position:0% +day. One minus at the end of the day. +And the familiar or famous + + align:start position:0% +And the familiar or famous + + + align:start position:0% +And the familiar or famous +formula comes + + align:start position:0% +formula comes + + + align:start position:0% +formula comes +out + + align:start position:0% +out + + + align:start position:0% +out +that delta of a on + + align:start position:0% +that delta of a on + + + align:start position:0% +that delta of a on +squared is equal to expectation value of + + align:start position:0% +squared is equal to expectation value of + + + align:start position:0% +squared is equal to expectation value of +a^ 2 minus expectation value of a + + align:start position:0% +a^ 2 minus expectation value of a + + + align:start position:0% +a^ 2 minus expectation value of a +squared which shows something uh quite + + align:start position:0% +squared which shows something uh quite + + + align:start position:0% +squared which shows something uh quite +powerful. This is has connections of + + align:start position:0% +powerful. This is has connections of + + + align:start position:0% +powerful. This is has connections of +course with statistical mechanics and + + align:start position:0% +course with statistical mechanics and + + + align:start position:0% +course with statistical mechanics and +standard + + align:start position:0% +standard + + + align:start position:0% +standard +deviations. + + align:start position:0% +deviations. + + + align:start position:0% +deviations. +Um is the probabilistic interpretation + + align:start position:0% +Um is the probabilistic interpretation + + + align:start position:0% +Um is the probabilistic interpretation +of this formula. But one fact that this + + align:start position:0% +of this formula. But one fact that this + + + align:start position:0% +of this formula. But one fact that this +has allowed us to prove is that the + + align:start position:0% +has allowed us to prove is that the + + + align:start position:0% +has allowed us to prove is that the +expectation value of a squared is always + + align:start position:0% +expectation value of a squared is always + + + align:start position:0% +expectation value of a squared is always +greater or equal than that because this + + align:start position:0% +greater or equal than that because this + + + align:start position:0% +greater or equal than that because this +number is positive because it's the + + align:start position:0% +number is positive because it's the + + + align:start position:0% +number is positive because it's the +square of a real positive number. So + + align:start position:0% +square of a real positive number. So + + + align:start position:0% +square of a real positive number. So +that's a slightly non-trivial thing and + + align:start position:0% +that's a slightly non-trivial thing and + + + align:start position:0% +that's a slightly non-trivial thing and +it's good to know + + align:start position:0% +it's good to know + + + align:start position:0% +it's good to know +it. + + align:start position:0% +it. + + + align:start position:0% +it. +Now and this formula of course is very + + align:start position:0% +Now and this formula of course is very + + + align:start position:0% +Now and this formula of course is very +well + + align:start position:0% +well + + + align:start position:0% +well +known. Now I'm going to give now a a + + align:start position:0% +known. Now I'm going to give now a a + + + align:start position:0% +known. Now I'm going to give now a a +funny geometrical interpretation of the + + align:start position:0% +funny geometrical interpretation of the + + + align:start position:0% +funny geometrical interpretation of the +uncertainty. Maybe you will find it + + align:start position:0% +uncertainty. Maybe you will find it + + + align:start position:0% +uncertainty. Maybe you will find it +illuminating in some way is turning into + + align:start position:0% +illuminating in some way is turning into + + + align:start position:0% +illuminating in some way is turning into +pictures all the calculations we've + + align:start position:0% +pictures all the calculations we've + + + align:start position:0% +pictures all the calculations we've +done. I think it actually adds value to + + align:start position:0% +done. I think it actually adds value to + + + align:start position:0% +done. I think it actually adds value to +it and uh I don't think it's very well + + align:start position:0% +it and uh I don't think it's very well + + + align:start position:0% +it and uh I don't think it's very well +known. Um or you know it's kind of funny + + align:start position:0% +known. Um or you know it's kind of funny + + + align:start position:0% +known. Um or you know it's kind of funny +because it's nice not be very well known + + align:start position:0% +because it's nice not be very well known + + + align:start position:0% +because it's nice not be very well known +but maybe people don't find it that + + align:start position:0% +but maybe people don't find it that + + + align:start position:0% +but maybe people don't find it that +suggestive but I I kind of find it + + align:start position:0% +suggestive but I I kind of find it + + + align:start position:0% +suggestive but I I kind of find it +suggestive. So here is what I want to + + align:start position:0% +suggestive. So here is what I want to + + + align:start position:0% +suggestive. So here is what I want to +say. + + align:start position:0% +say. + + + align:start position:0% +say. +Um + + align:start position:0% +Um + + + align:start position:0% +Um +geometrically you have this vector space + + align:start position:0% +geometrically you have this vector space + + + align:start position:0% +geometrically you have this vector space +and you have a vector + + align:start position:0% + + + + align:start position:0% + +pi. Then you come + + align:start position:0% +pi. Then you come + + + align:start position:0% +pi. Then you come +along and you act with the operator + + align:start position:0% +along and you act with the operator + + + align:start position:0% +along and you act with the operator +a. Now the fact that this thing is + + align:start position:0% +a. Now the fact that this thing is + + + align:start position:0% +a. Now the fact that this thing is +not an igen state means that the after + + align:start position:0% +not an igen state means that the after + + + align:start position:0% +not an igen state means that the after +you act with a you don't keep in the + + align:start position:0% +you act with a you don't keep in the + + + align:start position:0% +you act with a you don't keep in the +same direction. you go in different + + align:start position:0% +same direction. you go in different + + + align:start position:0% +same direction. you go in different +direction. So here + + align:start position:0% + + + + align:start position:0% + +is + + align:start position:0% + + + + align:start position:0% + +apesai. So what can we say here? Well + + align:start position:0% +apesai. So what can we say here? Well + + + align:start position:0% +apesai. So what can we say here? Well +actually here is this thing. Think of + + align:start position:0% +actually here is this thing. Think of + + + align:start position:0% +actually here is this thing. Think of +this vector + + align:start position:0% +this vector + + + align:start position:0% +this vector +space spanned by + + align:start position:0% + + + + align:start position:0% + +pi. Let's call it + + align:start position:0% +pi. Let's call it + + + align:start position:0% +pi. Let's call it +UPI. So it's that line + + align:start position:0% +UPI. So it's that line + + + align:start position:0% +UPI. So it's that line +there. You can + + align:start position:0% +there. You can + + + align:start position:0% +there. You can +project this in + + align:start position:0% +project this in + + + align:start position:0% +project this in +here + + align:start position:0% + + + + align:start position:0% + +orthogonally. Here is the first claim. + + align:start position:0% +orthogonally. Here is the first claim. + + + align:start position:0% +orthogonally. Here is the first claim. +The vector that you get up to here, this + + align:start position:0% +The vector that you get up to here, this + + + align:start position:0% +The vector that you get up to here, this +vector is nothing else but expectation + + align:start position:0% +vector is nothing else but expectation + + + align:start position:0% +vector is nothing else but expectation +value of a times + + align:start position:0% +value of a times + + + align:start position:0% +value of a times +pi. And that makes sense because it's a + + align:start position:0% +pi. And that makes sense because it's a + + + align:start position:0% +pi. And that makes sense because it's a +number time pi. But precisely the + + align:start position:0% +number time pi. But precisely the + + + align:start position:0% +number time pi. But precisely the +orthogonal projection is this. And here + + align:start position:0% +orthogonal projection is this. And here + + + align:start position:0% +orthogonal projection is this. And here +you get an orthogonal vector that we'll + + align:start position:0% +you get an orthogonal vector that we'll + + + align:start position:0% +you get an orthogonal vector that we'll +call it + + align:start position:0% + + + + align:start position:0% + +pi. And the funny thing about this piper + + align:start position:0% +pi. And the funny thing about this piper + + + align:start position:0% +pi. And the funny thing about this piper +is that its + + align:start position:0% +is that its + + + align:start position:0% +is that its +length is precisely the + + align:start position:0% + + + + align:start position:0% + +uncertainty. + + align:start position:0% +uncertainty. + + + align:start position:0% +uncertainty. +So all these you could trans prove I'm + + align:start position:0% +So all these you could trans prove I'm + + + align:start position:0% +So all these you could trans prove I'm +going to do it. Uh I'm going to show you + + align:start position:0% +going to do it. Uh I'm going to show you + + + align:start position:0% +going to do it. Uh I'm going to show you +all these things are true. But it gives + + align:start position:0% +all these things are true. But it gives + + + align:start position:0% +all these things are true. But it gives +you a bit of an insight. You have a + + align:start position:0% +you a bit of an insight. You have a + + + align:start position:0% +you a bit of an insight. You have a +vector a moves you out. What is the + + align:start position:0% +vector a moves you out. What is the + + + align:start position:0% +vector a moves you out. What is the +uncertainty is the this vertical + + align:start position:0% +uncertainty is the this vertical + + + align:start position:0% +uncertainty is the this vertical +projection vertical thing is the + + align:start position:0% +projection vertical thing is the + + + align:start position:0% +projection vertical thing is the +uncertainty. If you down there you get + + align:start position:0% +uncertainty. If you down there you get + + + align:start position:0% +uncertainty. If you down there you get +nothing. So uh how do we prove + + align:start position:0% +nothing. So uh how do we prove + + + align:start position:0% +nothing. So uh how do we prove +that? Well + + align:start position:0% +that? Well + + + align:start position:0% +that? Well +um let's construct a + + align:start position:0% +um let's construct a + + + align:start position:0% +um let's construct a +projector down to the space up which is + + align:start position:0% +projector down to the space up which is + + + align:start position:0% +projector down to the space up which is +just + + align:start position:0% +just + + + align:start position:0% +just +pi s. + + align:start position:0% +pi s. + + + align:start position:0% +pi s. +This is a + + align:start position:0% + + + + align:start position:0% + +projector just like any E1. E1 is a + + align:start position:0% +projector just like any E1. E1 is a + + + align:start position:0% +projector just like any E1. E1 is a +projector into the direction of one. + + align:start position:0% +projector into the direction of one. + + + align:start position:0% +projector into the direction of one. +Well, you know, take your first basis + + align:start position:0% +Well, you know, take your first basis + + + align:start position:0% +Well, you know, take your first basis +vector to be pi and that's a projection + + align:start position:0% +vector to be pi and that's a projection + + + align:start position:0% +vector to be pi and that's a projection +to the pi. So let's see what it + + align:start position:0% +to the pi. So let's see what it + + + align:start position:0% +to the pi. So let's see what it +it's a projection to pi. So now let's + + align:start position:0% +it's a projection to pi. So now let's + + + align:start position:0% +it's a projection to pi. So now let's +see what it gives you when it acts on a + + align:start position:0% +see what it gives you when it acts on a + + + align:start position:0% +see what it gives you when it acts on a +pi. + + align:start position:0% +pi. + + + align:start position:0% +pi. +This projector acting on a + + align:start position:0% + + + + align:start position:0% + +pi is equal to + + align:start position:0% +pi is equal to + + + align:start position:0% +pi is equal to +pi p + + align:start position:0% +pi p + + + align:start position:0% +pi p +si a + + align:start position:0% + + + + align:start position:0% + +pi and again the usefulness of bracket + + align:start position:0% +pi and again the usefulness of bracket + + + align:start position:0% +pi and again the usefulness of bracket +notation is kind of nice here. So what + + align:start position:0% +notation is kind of nice here. So what + + + align:start position:0% +notation is kind of nice here. So what +is this the expectation value of a. So + + align:start position:0% +is this the expectation value of a. So + + + align:start position:0% +is this the expectation value of a. So +indeed s expectation value of a is what + + align:start position:0% +indeed s expectation value of a is what + + + align:start position:0% +indeed s expectation value of a is what +you get when you project this + + align:start position:0% + + + + align:start position:0% + +down. + + align:start position:0% + + + + align:start position:0% + +So + + align:start position:0% + + + + align:start position:0% + +then the + + align:start position:0% +then the + + + align:start position:0% +then the +rest is sort of simple. So if you take + + align:start position:0% +rest is sort of simple. So if you take + + + align:start position:0% +rest is sort of simple. So if you take +pi and + + align:start position:0% +pi and + + + align:start position:0% +pi and +subtract from s + + align:start position:0% +subtract from s + + + align:start position:0% +subtract from s +um well + + align:start position:0% +um well + + + align:start position:0% +um well +I'll subtract from s u s times + + align:start position:0% +I'll subtract from s u s times + + + align:start position:0% +I'll subtract from s u s times +expectation value of a + + align:start position:0% + + + + align:start position:0% + +um you can I'm sorry I was saying it + + align:start position:0% +um you can I'm sorry I was saying it + + + align:start position:0% +um you can I'm sorry I was saying it +wrong. If you take the original vector a + + align:start position:0% + + + + align:start position:0% + +pi and subtract from it what we took + + align:start position:0% +pi and subtract from it what we took + + + align:start position:0% +pi and subtract from it what we took +out which is s time expectation value of + + align:start position:0% +out which is s time expectation value of + + + align:start position:0% +out which is s time expectation value of +a the projected thing. This is some + + align:start position:0% +a the projected thing. This is some + + + align:start position:0% +a the projected thing. This is some +vector but the main thing is that this + + align:start position:0% +vector but the main thing is that this + + + align:start position:0% +vector but the main thing is that this +vector is + + align:start position:0% +vector is + + + align:start position:0% +vector is +orthogonal to + + align:start position:0% +orthogonal to + + + align:start position:0% +orthogonal to +pi. Why? If you take a pi on the left, + + align:start position:0% +pi. Why? If you take a pi on the left, + + + align:start position:0% +pi. Why? If you take a pi on the left, +this is + + align:start position:0% +this is + + + align:start position:0% +this is +orthogonal to pi and how do you see it? + + align:start position:0% +orthogonal to pi and how do you see it? + + + align:start position:0% +orthogonal to pi and how do you see it? +Put up from the + + align:start position:0% +Put up from the + + + align:start position:0% +Put up from the +left and what do you get here? P a pi + + align:start position:0% +left and what do you get here? P a pi + + + align:start position:0% +left and what do you get here? P a pi +which is expectation value of a pi which + + align:start position:0% +which is expectation value of a pi which + + + align:start position:0% +which is expectation value of a pi which +is one and expectation value of a is + + align:start position:0% +is one and expectation value of a is + + + align:start position:0% +is one and expectation value of a is +zero. So this is a vector pip + + align:start position:0% +zero. So this is a vector pip + + + align:start position:0% +zero. So this is a vector pip +per and this is of course a minus + + align:start position:0% +per and this is of course a minus + + + align:start position:0% +per and this is of course a minus +expectation value of a acting on the + + align:start position:0% +expectation value of a acting on the + + + align:start position:0% +expectation value of a acting on the +state + + align:start position:0% +state + + + align:start position:0% +state +pi. Well precisely the norm of piper is + + align:start position:0% +pi. Well precisely the norm of piper is + + + align:start position:0% +pi. Well precisely the norm of piper is +the norm of this but that's what we + + align:start position:0% +the norm of this but that's what we + + + align:start position:0% +the norm of this but that's what we +define to be the uncertainty. + + align:start position:0% + + + + align:start position:0% + +So of indeed the norm of + + align:start position:0% + + + + align:start position:0% + +psy is delta a of + + align:start position:0% +psy is delta a of + + + align:start position:0% +psy is delta a of +pi. So our ideas of projectors and + + align:start position:0% +pi. So our ideas of projectors and + + + align:start position:0% +pi. So our ideas of projectors and +orthogonal projectors allow you to + + align:start position:0% +orthogonal projectors allow you to + + + align:start position:0% +orthogonal projectors allow you to +understand better what is the + + align:start position:0% +understand better what is the + + + align:start position:0% +understand better what is the +uncertainty more pictorially. You have a + + align:start position:0% +uncertainty more pictorially. You have a + + + align:start position:0% +uncertainty more pictorially. You have a +a pictures of vectors and orthogonal + + align:start position:0% +a pictures of vectors and orthogonal + + + align:start position:0% +a pictures of vectors and orthogonal +projections and you want to make the + + align:start position:0% +projections and you want to make the + + + align:start position:0% +projections and you want to make the +uncertainty zero. You have to push the a + + align:start position:0% +uncertainty zero. You have to push the a + + + align:start position:0% +uncertainty zero. You have to push the a +pi into pi. You have to be an ien state + + align:start position:0% +pi into pi. You have to be an ien state + + + align:start position:0% +pi into pi. You have to be an ien state +and you're there. Now the last thing + + align:start position:0% +and you're there. Now the last thing + + + align:start position:0% +and you're there. Now the last thing +I'll use the last five minutes to + + align:start position:0% +I'll use the last five minutes to + + + align:start position:0% +I'll use the last five minutes to +motivate the uncertainty the famous + + align:start position:0% +motivate the uncertainty the famous + + + align:start position:0% +motivate the uncertainty the famous +uncertainty + + align:start position:0% + + + + align:start position:0% + +theorem. Uncertainty theorem. + + align:start position:0% + + + + align:start position:0% + +And typically the uncertainty theorem is + + align:start position:0% +And typically the uncertainty theorem is + + + align:start position:0% +And typically the uncertainty theorem is +useful for A and + + align:start position:0% +useful for A and + + + align:start position:0% +useful for A and +B to her + + align:start position:0% +B to her + + + align:start position:0% +B to her +mission + + align:start position:0% + + + + align:start position:0% + +operators. And it relates the + + align:start position:0% +operators. And it relates the + + + align:start position:0% +operators. And it relates the +uncertainty in + + align:start position:0% +uncertainty in + + + align:start position:0% +uncertainty in +A on the state side to the uncertainty + + align:start position:0% +A on the state side to the uncertainty + + + align:start position:0% +A on the state side to the uncertainty +in + + align:start position:0% +in + + + align:start position:0% +in +B of Sing it must be bigger than or + + align:start position:0% +B of Sing it must be bigger than or + + + align:start position:0% +B of Sing it must be bigger than or +equal that some + + align:start position:0% + + + + align:start position:0% + +number. Now, if you look at + + align:start position:0% +number. Now, if you look at + + + align:start position:0% +number. Now, if you look at +that and you think of all the bath we've + + align:start position:0% +that and you think of all the bath we've + + + align:start position:0% +that and you think of all the bath we've +been talking + + align:start position:0% +been talking + + + align:start position:0% +been talking +about, you maybe know + + align:start position:0% +about, you maybe know + + + align:start position:0% +about, you maybe know +exactly how you're supposed to prove the + + align:start position:0% +exactly how you're supposed to prove the + + + align:start position:0% +exactly how you're supposed to prove the +uncertainty + + align:start position:0% + + + + align:start position:0% + +theorem. Well, what does this remind you + + align:start position:0% +theorem. Well, what does this remind you + + + align:start position:0% +theorem. Well, what does this remind you +of? + + align:start position:0% + + + + align:start position:0% + +Ky Schwarz. Uh, Schwarz inequality. I'm + + align:start position:0% +Ky Schwarz. Uh, Schwarz inequality. I'm + + + align:start position:0% +Ky Schwarz. Uh, Schwarz inequality. I'm +sorry, not Ky Schwartz. + + align:start position:0% +sorry, not Ky Schwartz. + + + align:start position:0% +sorry, not Ky Schwartz. +Why? Because and for Schwarz inequality + + align:start position:0% +Why? Because and for Schwarz inequality + + + align:start position:0% +Why? Because and for Schwarz inequality +you have norm of u norm of + + align:start position:0% +you have norm of u norm of + + + align:start position:0% +you have norm of u norm of +v is greater than or equal than the norm + + align:start position:0% +v is greater than or equal than the norm + + + align:start position:0% +v is greater than or equal than the norm +of the inner product of u and + + align:start position:0% +of the inner product of u and + + + align:start position:0% +of the inner product of u and +v absolute value of the inner product of + + align:start position:0% +v absolute value of the inner product of + + + align:start position:0% +v absolute value of the inner product of +u and + + align:start position:0% +u and + + + align:start position:0% +u and +v. Remember in this thing this is norm + + align:start position:0% +v. Remember in this thing this is norm + + + align:start position:0% +v. Remember in this thing this is norm +of a vector norm of a vector and this is + + align:start position:0% +of a vector norm of a vector and this is + + + align:start position:0% +of a vector norm of a vector and this is +value of a scalar and + + align:start position:0% +value of a scalar and + + + align:start position:0% +value of a scalar and +our uncertainties are + + align:start position:0% +our uncertainties are + + + align:start position:0% +our uncertainties are +norms. So it better be that that + + align:start position:0% +norms. So it better be that that + + + align:start position:0% +norms. So it better be that that +inequality is the only inequality that + + align:start position:0% +inequality is the only inequality that + + + align:start position:0% +inequality is the only inequality that +can possibly give you the + + align:start position:0% +can possibly give you the + + + align:start position:0% +can possibly give you the +answer. So + + align:start position:0% +answer. So + + + align:start position:0% +answer. So +uh how would you set this up? You would + + align:start position:0% +uh how would you set this up? You would + + + align:start position:0% +uh how would you set this up? You would +say define as we'll say + + align:start position:0% +say define as we'll say + + + align:start position:0% +say define as we'll say +f equal a min - + + align:start position:0% +f equal a min - + + + align:start position:0% +f equal a min - +a acting on + + align:start position:0% +a acting on + + + align:start position:0% +a acting on +pi and g is equal to b - + + align:start position:0% +pi and g is equal to b - + + + align:start position:0% +pi and g is equal to b - +b acting on pi and then + + align:start position:0% + + + + align:start position:0% + +f or ff is delta a squared + + align:start position:0% +f or ff is delta a squared + + + align:start position:0% +f or ff is delta a squared +F G F + + align:start position:0% + + + + align:start position:0% + +G is delta B + + align:start position:0% + + + + align:start position:0% + +squared and uh you just need to compute + + align:start position:0% +squared and uh you just need to compute + + + align:start position:0% +squared and uh you just need to compute +the inner product of + + align:start position:0% +the inner product of + + + align:start position:0% +the inner product of +FG because you need the mix one. + + align:start position:0% +FG because you need the mix one. + + + align:start position:0% +FG because you need the mix one. +So if you want to have fun, try it. + + align:start position:0% +So if you want to have fun, try it. + + + align:start position:0% +So if you want to have fun, try it. +We'll do it next time anyway. All right, + + align:start position:0% +We'll do it next time anyway. All right, + + + align:start position:0% +We'll do it next time anyway. All right, +that's it for \ No newline at end of file diff --git a/reYwbnuhFU0.txt b/reYwbnuhFU0.txt new file mode 100644 index 0000000000000000000000000000000000000000..7920a8479e096d1506c258aec84f9ba811d58096 --- /dev/null +++ b/reYwbnuhFU0.txt @@ -0,0 +1,602 @@ +PROFESSOR: Now having cut +DNA, we then need to + +do something else. + +What's the next thing +we have to do? + +AUDIENCE: Paste it. + +PROFESSOR: Paste it right. + +Oh, I put past. + +It should be paste. + +There we go. + +We should paste it. + +So, how are we going +to paste our DNA? + +So let's take some human DNA. + +We'll take your human DNA. + +We'll add EcoR1 to it. + +And your human DNA is going to +get cut up in lots of little + +pieces of length about 4,000. + +And I'm writing R1 at the ends +because these pieces of DNA + +have EcoR1 sites. + +Now, I can take that human DNA +and I can combine it with + +other pieces of DNA. + +Here's a piece of DNA. + +Remember it had this +overhang like that. + +T-T-A-A was this piece +here of human DNA. + +And I could take another piece +of DNA that matched it a + +A-A-T-T. + +And it doesn't have +to be human. + +It could be something else. + +It could be zebra. + +Some human DNA, some zebra DNA, +and by that base pairing + +of those four bases, they'll +sort of stick. + +It's not that strong. + +It's four bases of base pairing, +but they'll stick. + +Now I'd like to glue +them together. + +What's the word for attaching +together DNA strands? + +We talked about it-- + +Ligate, we want to ligate +them together. + +So now we go back to our MIT +engineers and say, please + +invent me a protein that's +able to ligate + +together pieces of DNA. + +But actually, who invented +it first? + +Bacteria invented it first. + +And it's called? + +Ligase. + +So all we have to do +is add ligase. + +So it was kind of useful +to know how + +DNA replication worked. + +We add ligase. + +And what does ligase +do for a living? + +For a living, ligase is paid to +go around and find pieces + +of DNA that have nicks and seal +them back up by repairing + +the sugar phosphate +backbone of DNA. + +And again, ancient molecular +biologists would prove their + +mettle by purifying ligase and +using it in their reactions. + +And today, where do +we get ligase? + +It's in the catalog. + +Ligase is in the catalog, +reasonably cheap. + +So, when we add ligase we could +now get a hybrid piece + +of DNA that was half human +and half zebra. + +I got to say, this freaks +some people out. + +This doesn't freak me out +because it's just a sequence + +of nucleotides. + +If I give you a sequence of +nucleotides, to my mind, + +there's nothing human +or zebra about it. + +It's a chemical. + +And you can make bonds between +chemicals and all that. + +So, we now pasted our +DNA using ligase. + +Ligase from the catalog. + +Now the question is, what are we +going to paste our DNA to? + +What do we paste our DNA to? + +We're going to paste our DNA to +a fascinating other piece + +of DNA like this. + +I'll make that a little +bigger here. + +That has an EcoR1 site, +has an EcoR1 site. + +And we're going to take our +human DNA and paste it in such + +a way that it makes a circle. + +This piece of DNA is a vector. + +Vector means it travels +around. + +It carries things with it. + +So I want this vector to be +able to replicate if I + +transfer it to E Coli. + +So that's the trick. + +I would like to be able to +attachment my human DNA to + +this vector DNA, and when I +transfer it to E coli, have + +this thing be able to grow. + +So that means we need to invent +a piece of DNA, a + +vector, that is capable +of causing E. coli + +to replicate itself. + +It's got to have all the +instructions to cause E. coli + +to replicate this +piece of DNA. + +So this is another amazing +bit of engineering. + +How do we invent just the right +sequence of letters that + +would allow E. coli to +replicate this thing? + +AUDIENCE: Already +been invented. + +PROFESSOR: Sorry. + +AUDIENCE: It's already been +invented by E. coli. + +PROFESSOR: It's already +been invented by E. + +coli, hasn't it? + +So you're getting the theme +here, is that we don't + +actually do anything in +molecular biology. + +Now look, in fairness, life's +had 3.5 billion years. + +We've been at this a decade +or two, on the + +whole, maybe three. + +On the whole, life's had +a lot more time to + +work this stuff out. + +And usually the best solution +is to look in nature to see + +where nature has already +done it for you. + +So E. coli, it turns out, +replicates its own chromosome. + +You could use the machinery +from its own chromosome. + +But it turns out even +better than that. + +E. coli has the following. + +Here's its big chromosome, four +million letters of E. + +coli chromosome. + +E. Coli also has within +it little circles + +of DNA called plasmids. + +These little circles +of DNA are able to + +autonomously replicate. + +They can copy themselves. + +Or that is to say, E. +coli copies them. + +These little plasmids have the +full replication instructions + +encoded in them. + +Now why does E. coli have +these plasmids? + +What's in these plasmids? + +What's going on? + +Well let's blow up one +of these plasmids. + +It's a big circle. + +And it has an instruction here, +a sequence, called an + +origin of replication - or +amongst friends, just ORI. + +It's called ORI. + +You'll find on maps, origin +of replication. + +That sequence alone is enough to +cause E. coli to open it up + +and start doing its DNA +replication from the origin. + +But what tells you why this is +so important is that these + +plasmids typically have +one or two genes. + +And the one or two genes that +they typically have are genes + +that encode a protein that gives +them resistance to an + +antibiotic, like say, +penicillin. + +There could be a gene that +gives you penicillin + +resistance. + +That's kind of cool. + +E. coli, or other bacteria-- + +not E. coli necessarily +for penicillin-- + +carry around often +little circles. + +And these little circles encode +genes that give them + +resistance to streptomycin, +penicillin, ampicillin, all + +sorts of things. + +This allows it to grow, even if +you're taking penicillin. + +Now, that's pretty clever. + +How did E. Coli come up? + +How is it so smart to know to +have come up with a gene able + +to break down penicillin, given +that we've only been + +using penicillin since +the 1940s? + +Pretty fast for E. coli to have +figured out how to do + +that, isn't it? + +Oh yeah, who invented +penicillin? + +Nature invented penicillin. + +It's produced by fungi. + +Fungi have been fighting E. +Coli with penicillin for + +millions of years. + +E. coli didn't invent +it for us. + +E. Coli invented it because it's +in a war down there at + +the single cell level +with fungi. + +Fungi make antibi-- + +You see, we think +we're so cool. + +We make antibiotics. + +Well we've been making +antibiotics + +only since the 1940s. + +Nature's been making antibiotics +forever. + +Just like the viruses are +infecting E. coli and E. coli + +needs an immune system +against the viruses. + +Well the fungi are throwing +antibiotics at the bacteria + +and it needs a defense +mechanism. + +And the defense mechanism are +these genes that can break + +down those antibiotics. + +And as usual, we just +come along and we + +say, oh look at that. + +It's already been invented. + +Kind of cool. + +We'll use that one too. + +Now why are these on these +little circles? + +They're on the little circles +because when this bacteria has + +lived a long and happy life and +it dies and it spews its + +guts out, neighboring bacteria +suck up the DNA. + +Sounds a little cannibalistic +or something. + +But that's how it +is down there at + +the single cell level. + +The neighboring bacteria +will suck up DNA. + +And why is that cool? + +It's cool because they can +acquire these resistances. + +That's pretty impressive. + +They can acquire +the resistance. + +And in fact, it even works +across species. + +That's why you don't put it +on the chromosome here. + +Because E. coli could pick it up +from another species that's + +not E. coli, but related +enough that it + +can use that plasmid. + +And you can transfer antibiotic +resistance across + +many species of bacteria. + +So the bacteria like to suck up +DNA and see what they find. + +Pretty cool. + +By the way, this is also why +indiscriminate use of + +antibiotics, for example, in +animal feed, or when you were + +given antibiotics by the MIT +health service and are told to + +take them for two weeks and you +take them for five days, + +you're not doing anything +very good. + +You're just selecting for +bacteria that can grow in the + +presence of antibiotics and +selecting for multidrug + +resistance in the spread +of antibiotics. + +We have to be pretty careful. + +Because all these mechanisms +of swapping antibiotic + +resistance are pretty +impressive tricks. + +Anyway, so these things exist. + +And originally, molecular +biologists + +discovered these plasmids. + +They purified these plasmids. + +And the deal was this, +they cut the + +plasmid with EcoR1, ideally. + +So I'm going to put this +up here, vectors. + +They cut the plasmid +with EcoR1. + +They ligate human DNA into it. + +And they get these circles. + +And there you go. + +Now today, obviously, if I +wanted to do this experiment, + +would I purify the +plasmid myself? + +No. + +Where would I get the +plasmid from? + +AUDIENCE: Catalog. + +PROFESSOR: It's in +the catalog. + +There's a whole section +a plasmids here. + +They have vectors +of all sorts. + +So you get it from +the catalog. + +All right. \ No newline at end of file diff --git a/sB547f1ogWc.txt b/sB547f1ogWc.txt new file mode 100644 index 0000000000000000000000000000000000000000..004b3612aaf268d22ae3c0d960c936a368e33e3b --- /dev/null +++ b/sB547f1ogWc.txt @@ -0,0 +1,8922 @@ +align:start position:0% + +so I wanted to keep talking about uh DC + + align:start position:0% +so I wanted to keep talking about uh DC + + + align:start position:0% +so I wanted to keep talking about uh DC +todc converters today and keep talking + + align:start position:0% +todc converters today and keep talking + + + align:start position:0% +todc converters today and keep talking +about the impact of Ripple and operating + + align:start position:0% +about the impact of Ripple and operating + + + align:start position:0% +about the impact of Ripple and operating +modes of DCd converters right so we said + + align:start position:0% +modes of DCd converters right so we said + + + align:start position:0% +modes of DCd converters right so we said +we we did some analysis last time and + + align:start position:0% +we we did some analysis last time and + + + align:start position:0% +we we did some analysis last time and +what we found is that under reasonable + + align:start position:0% +what we found is that under reasonable + + + align:start position:0% +what we found is that under reasonable +approximations the inductor current wave + + align:start position:0% +approximations the inductor current wave + + + align:start position:0% +approximations the inductor current wave +forms in a pwm dcdc converter tend to + + align:start position:0% +forms in a pwm dcdc converter tend to + + + align:start position:0% +forms in a pwm dcdc converter tend to +look like some DC Value Plus some + + align:start position:0% +look like some DC Value Plus some + + + align:start position:0% +look like some DC Value Plus some +triangular + + align:start position:0% +triangular + + + align:start position:0% +triangular +Ripple and the same thing for the + + align:start position:0% +Ripple and the same thing for the + + + align:start position:0% +Ripple and the same thing for the +capacitor voltage waveforms okay and we + + align:start position:0% +capacitor voltage waveforms okay and we + + + align:start position:0% +capacitor voltage waveforms okay and we +said that we could represent this kind + + align:start position:0% +said that we could represent this kind + + + align:start position:0% +said that we could represent this kind +of waveform sort of a triangle wave with + + align:start position:0% +of waveform sort of a triangle wave with + + + align:start position:0% +of waveform sort of a triangle wave with +an offset as having some DC + + align:start position:0% +an offset as having some DC + + + align:start position:0% +an offset as having some DC +value uh plus triangular Ripple where we + + align:start position:0% +value uh plus triangular Ripple where we + + + align:start position:0% +value uh plus triangular Ripple where we +could find the we could Define + + align:start position:0% +could find the we could Define + + + align:start position:0% +could find the we could Define +the average value and then the peak + + align:start position:0% +the average value and then the peak + + + align:start position:0% +the average value and then the peak +value and because of the properties of a + + align:start position:0% +value and because of the properties of a + + + align:start position:0% +value and because of the properties of a +triangle wave the peak is right in the + + align:start position:0% +triangle wave the peak is right in the + + + align:start position:0% +triangle wave the peak is right in the +average is right in the middle of + + align:start position:0% +average is right in the middle of + + + align:start position:0% +average is right in the middle of +between the two peaks so you sort of + + align:start position:0% +between the two peaks so you sort of + + + align:start position:0% +between the two peaks so you sort of +Swing Delta X Peak to Peak over two + + align:start position:0% +Swing Delta X Peak to Peak over two + + + align:start position:0% +Swing Delta X Peak to Peak over two +above the average and Delta X Peak to + + align:start position:0% +above the average and Delta X Peak to + + + align:start position:0% +above the average and Delta X Peak to +Peak over to below the average okay and + + align:start position:0% +Peak over to below the average okay and + + + align:start position:0% +Peak over to below the average okay and +so we can Define sort of a ripple ratio + + align:start position:0% +so we can Define sort of a ripple ratio + + + align:start position:0% +so we can Define sort of a ripple ratio +for such a wave form sort of a notion of + + align:start position:0% +for such a wave form sort of a notion of + + + align:start position:0% +for such a wave form sort of a notion of +a percentage Ripple which we Define in + + align:start position:0% +a percentage Ripple which we Define in + + + align:start position:0% +a percentage Ripple which we Define in +this class as half half of the peak to + + align:start position:0% +this class as half half of the peak to + + + align:start position:0% +this class as half half of the peak to +Peak swing or the mean to Peak swing + + align:start position:0% +Peak swing or the mean to Peak swing + + + align:start position:0% +Peak swing or the mean to Peak swing +normalized to the average + + align:start position:0% +normalized to the average + + + align:start position:0% +normalized to the average +value okay and one of the nice things + + align:start position:0% +value okay and one of the nice things + + + align:start position:0% +value okay and one of the nice things +about that is we can then if I knew the + + align:start position:0% +about that is we can then if I knew the + + + align:start position:0% +about that is we can then if I knew the +average value from our calculations I + + align:start position:0% +average value from our calculations I + + + align:start position:0% +average value from our calculations I +can actually find the peak value as + + align:start position:0% +can actually find the peak value as + + + align:start position:0% +can actually find the peak value as +being the average time 1 plus the Ripple + + align:start position:0% +being the average time 1 plus the Ripple + + + align:start position:0% +being the average time 1 plus the Ripple +ratio okay um if we apply + + align:start position:0% +ratio okay um if we apply + + + align:start position:0% +ratio okay um if we apply +that we also talked about the device + + align:start position:0% +that we also talked about the device + + + align:start position:0% +that we also talked about the device +stresses in a direct converter such as a + + align:start position:0% +stresses in a direct converter such as a + + + align:start position:0% +stresses in a direct converter such as a +buck or a boost converter and an + + align:start position:0% +buck or a boost converter and an + + + align:start position:0% +buck or a boost converter and an +indirect converter such as the the uh + + align:start position:0% +indirect converter such as the the uh + + + align:start position:0% +indirect converter such as the the uh +inverting buck boost converter and we + + align:start position:0% +inverting buck boost converter and we + + + align:start position:0% +inverting buck boost converter and we +had written it as sort of for a direct + + align:start position:0% +had written it as sort of for a direct + + + align:start position:0% +had written it as sort of for a direct +converter the peak switch voltage the + + align:start position:0% +converter the peak switch voltage the + + + align:start position:0% +converter the peak switch voltage the +peak di voltage which is also the peak + + align:start position:0% +peak di voltage which is also the peak + + + align:start position:0% +peak di voltage which is also the peak +capacitor voltage is this maximum of V1 + + align:start position:0% +capacitor voltage is this maximum of V1 + + + align:start position:0% +capacitor voltage is this maximum of V1 +and V2 times 1 plus the Ripple ratio + + align:start position:0% +and V2 times 1 plus the Ripple ratio + + + align:start position:0% +and V2 times 1 plus the Ripple ratio +that's how we get from this is the + + align:start position:0% +that's how we get from this is the + + + align:start position:0% +that's how we get from this is the +average DC value we see in terms of the + + align:start position:0% +average DC value we see in terms of the + + + align:start position:0% +average DC value we see in terms of the +DC Value Plus the Ripple on the passer + + align:start position:0% +DC Value Plus the Ripple on the passer + + + align:start position:0% +DC Value Plus the Ripple on the passer +voltage increases the peak voltages we + + align:start position:0% +voltage increases the peak voltages we + + + align:start position:0% +voltage increases the peak voltages we +see a little bit and likewise we can + + align:start position:0% +see a little bit and likewise we can + + + align:start position:0% +see a little bit and likewise we can +talk about the uh switch current and the + + align:start position:0% +talk about the uh switch current and the + + + align:start position:0% +talk about the uh switch current and the +diode current Peak values which are + + align:start position:0% +diode current Peak values which are + + + align:start position:0% +diode current Peak values which are +related to the maximum of the average + + align:start position:0% +related to the maximum of the average + + + align:start position:0% +related to the maximum of the average +and input and output currents okay so + + align:start position:0% +and input and output currents okay so + + + align:start position:0% +and input and output currents okay so +for a buck converter the output current + + align:start position:0% +for a buck converter the output current + + + align:start position:0% +for a buck converter the output current +is the bigger one and the input voltage + + align:start position:0% +is the bigger one and the input voltage + + + align:start position:0% +is the bigger one and the input voltage +is the bigger one but we see Peak + + align:start position:0% +is the bigger one but we see Peak + + + align:start position:0% +is the bigger one but we see Peak +stresses and uh and voltage and current + + align:start position:0% +stresses and uh and voltage and current + + + align:start position:0% +stresses and uh and voltage and current +that are related to the maximum of the + + align:start position:0% +that are related to the maximum of the + + + align:start position:0% +that are related to the maximum of the +input and output DC waveforms and the + + align:start position:0% +input and output DC waveforms and the + + + align:start position:0% +input and output DC waveforms and the +Ripple + + align:start position:0% +Ripple + + + align:start position:0% +Ripple +okay then we looked also at this + + align:start position:0% +okay then we looked also at this + + + align:start position:0% +okay then we looked also at this +indirect converter we found the + + align:start position:0% +indirect converter we found the + + + align:start position:0% +indirect converter we found the +difference is instead of seeing the + + align:start position:0% +difference is instead of seeing the + + + align:start position:0% +difference is instead of seeing the +maximum of the input and output we see + + align:start position:0% +maximum of the input and output we see + + + align:start position:0% +maximum of the input and output we see +the sum of the input and output currents + + align:start position:0% +the sum of the input and output currents + + + align:start position:0% +the sum of the input and output currents +and voltages okay so this tells us no + + align:start position:0% +and voltages okay so this tells us no + + + align:start position:0% +and voltages okay so this tells us no +matter what for a given conversion ratio + + align:start position:0% +matter what for a given conversion ratio + + + align:start position:0% +matter what for a given conversion ratio +V1 V2 i1 I2 we're always going to have + + align:start position:0% +V1 V2 i1 I2 we're always going to have + + + align:start position:0% +V1 V2 i1 I2 we're always going to have +higher stresses in an indirect converter + + align:start position:0% +higher stresses in an indirect converter + + + align:start position:0% +higher stresses in an indirect converter +compared to a direct converter and that + + align:start position:0% +compared to a direct converter and that + + + align:start position:0% +compared to a direct converter and that +makes sense because of how we're + + align:start position:0% +makes sense because of how we're + + + align:start position:0% +makes sense because of how we're +processing energy through the converter + + align:start position:0% +processing energy through the converter + + + align:start position:0% +processing energy through the converter +the indirect converter you're basically + + align:start position:0% +the indirect converter you're basically + + + align:start position:0% +the indirect converter you're basically +storing all the energy in the middle of + + align:start position:0% +storing all the energy in the middle of + + + align:start position:0% +storing all the energy in the middle of +the converter and in the direct + + align:start position:0% +the converter and in the direct + + + align:start position:0% +the converter and in the direct +converter you're sort of some of it gets + + align:start position:0% +converter you're sort of some of it gets + + + align:start position:0% +converter you're sort of some of it gets +to flow right through the converter you + + align:start position:0% +to flow right through the converter you + + + align:start position:0% +to flow right through the converter you +can take advantage of that okay so this + + align:start position:0% +can take advantage of that okay so this + + + align:start position:0% +can take advantage of that okay so this +is just a quick review of the + + align:start position:0% +is just a quick review of the + + + align:start position:0% +is just a quick review of the +conclusions we came to last time any + + align:start position:0% +conclusions we came to last time any + + + align:start position:0% +conclusions we came to last time any +questions about this so + + align:start position:0% + + + + align:start position:0% + +far the other thing we did was then we + + align:start position:0% +far the other thing we did was then we + + + align:start position:0% +far the other thing we did was then we +took that and we said okay well I know + + align:start position:0% +took that and we said okay well I know + + + align:start position:0% +took that and we said okay well I know +that my inductor current for example has + + align:start position:0% +that my inductor current for example has + + + align:start position:0% +that my inductor current for example has +some triangular Ripple on it right so + + align:start position:0% +some triangular Ripple on it right so + + + align:start position:0% +some triangular Ripple on it right so +this this iil looks like some average + + align:start position:0% +this this iil looks like some average + + + align:start position:0% +this this iil looks like some average +value and some Ripple right and we could + + align:start position:0% +value and some Ripple right and we could + + + align:start position:0% +value and some Ripple right and we could +calculate if I wanted to limit my + + align:start position:0% +calculate if I wanted to limit my + + + align:start position:0% +calculate if I wanted to limit my +peak-to Peak inductor current Ripple + + align:start position:0% +peak-to Peak inductor current Ripple + + + align:start position:0% +peak-to Peak inductor current Ripple +below some value because that's my input + + align:start position:0% +below some value because that's my input + + + align:start position:0% +below some value because that's my input +Ripple current or my Peak to Peak output + + align:start position:0% +Ripple current or my Peak to Peak output + + + align:start position:0% +Ripple current or my Peak to Peak output +voltage Ripple below a certain value I + + align:start position:0% +voltage Ripple below a certain value I + + + align:start position:0% +voltage Ripple below a certain value I +can come up with + + align:start position:0% +can come up with + + + align:start position:0% +can come up with +minimum capacitor and inductor values to + + align:start position:0% +minimum capacitor and inductor values to + + + align:start position:0% +minimum capacitor and inductor values to +do that that are related to you know the + + align:start position:0% +do that that are related to you know the + + + align:start position:0% +do that that are related to you know the +conversion + + align:start position:0% +conversion + + + align:start position:0% +conversion +ratio and I expressed it here in terms + + align:start position:0% +ratio and I expressed it here in terms + + + align:start position:0% +ratio and I expressed it here in terms +of the allowed Ripple ratio of the + + align:start position:0% +of the allowed Ripple ratio of the + + + align:start position:0% +of the allowed Ripple ratio of the +designs okay so now we have a means to + + align:start position:0% +designs okay so now we have a means to + + + align:start position:0% +designs okay so now we have a means to +start sizing inductors and capacitors + + align:start position:0% +start sizing inductors and capacitors + + + align:start position:0% +start sizing inductors and capacitors +right we can't practically use nearly + + align:start position:0% +right we can't practically use nearly + + + align:start position:0% +right we can't practically use nearly +infinite ones because they get too big + + align:start position:0% +infinite ones because they get too big + + + align:start position:0% +infinite ones because they get too big +and expensive if you have too smaller + + align:start position:0% +and expensive if you have too smaller + + + align:start position:0% +and expensive if you have too smaller +one you get too much Ripple and bad + + align:start position:0% +one you get too much Ripple and bad + + + align:start position:0% +one you get too much Ripple and bad +things happen and so the question is how + + align:start position:0% +things happen and so the question is how + + + align:start position:0% +things happen and so the question is how +do you pick those values and one of the + + align:start position:0% +do you pick those values and one of the + + + align:start position:0% +do you pick those values and one of the +things that used to pick those values is + + align:start position:0% +things that used to pick those values is + + + align:start position:0% +things that used to pick those values is +some sort of notion of an an allowable + + align:start position:0% +some sort of notion of an an allowable + + + align:start position:0% +some sort of notion of an an allowable +Ripple which we could express in terms + + align:start position:0% +Ripple which we could express in terms + + + align:start position:0% +Ripple which we could express in terms +of peak to Peak Ripple or we could + + align:start position:0% +of peak to Peak Ripple or we could + + + align:start position:0% +of peak to Peak Ripple or we could +express in terms of Ripple ratios okay + + align:start position:0% +express in terms of Ripple ratios okay + + + align:start position:0% +express in terms of Ripple ratios okay +typically you know in this example + + align:start position:0% +typically you know in this example + + + align:start position:0% +typically you know in this example +you're not usually allowed very much + + align:start position:0% +you're not usually allowed very much + + + align:start position:0% +you're not usually allowed very much +Ripple ratio on the capacitor right + + align:start position:0% +Ripple ratio on the capacitor right + + + align:start position:0% +Ripple ratio on the capacitor right +because um you know if you want a DC + + align:start position:0% +because um you know if you want a DC + + + align:start position:0% +because um you know if you want a DC +output voltage you can't have 10% Ripple + + align:start position:0% +output voltage you can't have 10% Ripple + + + align:start position:0% +output voltage you can't have 10% Ripple +in your up voltage that would usually be + + align:start position:0% +in your up voltage that would usually be + + + align:start position:0% +in your up voltage that would usually be +bad right so maybe that's a percent or + + align:start position:0% +bad right so maybe that's a percent or + + + align:start position:0% +bad right so maybe that's a percent or +something it depends on your + + align:start position:0% +something it depends on your + + + align:start position:0% +something it depends on your +specifications inductor current Ripple + + align:start position:0% +specifications inductor current Ripple + + + align:start position:0% +specifications inductor current Ripple +um you know maybe a bit more is + + align:start position:0% +um you know maybe a bit more is + + + align:start position:0% +um you know maybe a bit more is +acceptable maybe you could have 25% + + align:start position:0% +acceptable maybe you could have 25% + + + align:start position:0% +acceptable maybe you could have 25% +Ripple in that current especially if you + + align:start position:0% +Ripple in that current especially if you + + + align:start position:0% +Ripple in that current especially if you +add on you know another capacitor to + + align:start position:0% +add on you know another capacitor to + + + align:start position:0% +add on you know another capacitor to +help you filter it back here + + align:start position:0% +help you filter it back here + + + align:start position:0% +help you filter it back here +okay so um there's the notion of sizing + + align:start position:0% +okay so um there's the notion of sizing + + + align:start position:0% +okay so um there's the notion of sizing +and we'll talk about this is sort of one + + align:start position:0% +and we'll talk about this is sort of one + + + align:start position:0% +and we'll talk about this is sort of one +way you can start to pick your inductor + + align:start position:0% +way you can start to pick your inductor + + + align:start position:0% +way you can start to pick your inductor +and capacitor values based on Ripple + + align:start position:0% +and capacitor values based on Ripple + + + align:start position:0% +and capacitor values based on Ripple +there are other factors too where we + + align:start position:0% +there are other factors too where we + + + align:start position:0% +there are other factors too where we +said size right so you can kind of + + align:start position:0% +said size right so you can kind of + + + align:start position:0% +said size right so you can kind of +figure the biggest value you can get + + align:start position:0% +figure the biggest value you can get + + + align:start position:0% +figure the biggest value you can get +before it gets too big is probably a + + align:start position:0% +before it gets too big is probably a + + + align:start position:0% +before it gets too big is probably a +good thing but also in terms of + + align:start position:0% +good thing but also in terms of + + + align:start position:0% +good thing but also in terms of +transient performance the dynamic + + align:start position:0% +transient performance the dynamic + + + align:start position:0% +transient performance the dynamic +performance your converter we'll talk + + align:start position:0% +performance your converter we'll talk + + + align:start position:0% +performance your converter we'll talk +about that aspect a little later but + + align:start position:0% +about that aspect a little later but + + + align:start position:0% +about that aspect a little later but +that can also come into to how you pick + + align:start position:0% +that can also come into to how you pick + + + align:start position:0% +that can also come into to how you pick +the values and the reason I mentioned + + align:start position:0% +the values and the reason I mentioned + + + align:start position:0% +the values and the reason I mentioned +that is because you know in your design + + align:start position:0% +that is because you know in your design + + + align:start position:0% +that is because you know in your design +project you're going to have to pick + + align:start position:0% +project you're going to have to pick + + + align:start position:0% +project you're going to have to pick +values and you're going to have to think + + align:start position:0% +values and you're going to have to think + + + align:start position:0% +values and you're going to have to think +about these different aspects okay um + + align:start position:0% +about these different aspects okay um + + + align:start position:0% +about these different aspects okay um +the other thing we said was okay if I + + align:start position:0% +the other thing we said was okay if I + + + align:start position:0% +the other thing we said was okay if I +have some minimum values based on Ripple + + align:start position:0% +have some minimum values based on Ripple + + + align:start position:0% +have some minimum values based on Ripple +what is that say about the energy + + align:start position:0% +what is that say about the energy + + + align:start position:0% +what is that say about the energy +storage requirement of my inductor and + + align:start position:0% +storage requirement of my inductor and + + + align:start position:0% +storage requirement of my inductor and +my capacitor and the reason we talk + + align:start position:0% +my capacitor and the reason we talk + + + align:start position:0% +my capacitor and the reason we talk +about energy storage requirement is + + align:start position:0% +about energy storage requirement is + + + align:start position:0% +about energy storage requirement is +because we ought to you know it's + + align:start position:0% +because we ought to you know it's + + + align:start position:0% +because we ought to you know it's +reasonable to expect that the size of + + align:start position:0% +reasonable to expect that the size of + + + align:start position:0% +reasonable to expect that the size of +your component is probably monotonic + + align:start position:0% +your component is probably monotonic + + + align:start position:0% +your component is probably monotonic +with its energy storage capability right + + align:start position:0% +with its energy storage capability right + + + align:start position:0% +with its energy storage capability right +it's going to get bigger if you have to + + align:start position:0% +it's going to get bigger if you have to + + + align:start position:0% +it's going to get bigger if you have to +store more energy usually right there's + + align:start position:0% +store more energy usually right there's + + + align:start position:0% +store more energy usually right there's +a + + align:start position:0% +a + + + align:start position:0% +a +complex tradeoff to design actual + + align:start position:0% +complex tradeoff to design actual + + + align:start position:0% +complex tradeoff to design actual +especially magnetic components but + + align:start position:0% +especially magnetic components but + + + align:start position:0% +especially magnetic components but +nonetheless it's reasonable to expect + + align:start position:0% +nonetheless it's reasonable to expect + + + align:start position:0% +nonetheless it's reasonable to expect +that and what we can see from this + + align:start position:0% +that and what we can see from this + + + align:start position:0% +that and what we can see from this +expression is that if I looked at the + + align:start position:0% +expression is that if I looked at the + + + align:start position:0% +expression is that if I looked at the +energ stored in the capacitor right it + + align:start position:0% +energ stored in the capacitor right it + + + align:start position:0% +energ stored in the capacitor right it +gets + + align:start position:0% +gets + + + align:start position:0% +gets +bigger if I have smaller Ripple ratio + + align:start position:0% +bigger if I have smaller Ripple ratio + + + align:start position:0% +bigger if I have smaller Ripple ratio +this this Factor here tends to get big + + align:start position:0% +this this Factor here tends to get big + + + align:start position:0% +this this Factor here tends to get big +if I make Ripple ratio very + + align:start position:0% +if I make Ripple ratio very + + + align:start position:0% +if I make Ripple ratio very +small okay it gets bigger proportional + + align:start position:0% +small okay it gets bigger proportional + + + align:start position:0% +small okay it gets bigger proportional +to the power my converter needs to + + align:start position:0% +to the power my converter needs to + + + align:start position:0% +to the power my converter needs to +handle okay that's kind of reasonable if + + align:start position:0% +handle okay that's kind of reasonable if + + + align:start position:0% +handle okay that's kind of reasonable if +I want a kilowatt converter it's going + + align:start position:0% +I want a kilowatt converter it's going + + + align:start position:0% +I want a kilowatt converter it's going +to be physically have more energy + + align:start position:0% +to be physically have more energy + + + align:start position:0% +to be physically have more energy +storage than 100 watt + + align:start position:0% +storage than 100 watt + + + align:start position:0% +storage than 100 watt +converter it depends depends on the + + align:start position:0% +converter it depends depends on the + + + align:start position:0% +converter it depends depends on the +conversion ratio and in this case for a + + align:start position:0% +conversion ratio and in this case for a + + + align:start position:0% +conversion ratio and in this case for a +boost converter a bigger conversion + + align:start position:0% +boost converter a bigger conversion + + + align:start position:0% +boost converter a bigger conversion +ratio is a bigger duty cycle so the More + + align:start position:0% +ratio is a bigger duty cycle so the More + + + align:start position:0% +ratio is a bigger duty cycle so the More +Voltage conversion I'm doing the more + + align:start position:0% +Voltage conversion I'm doing the more + + + align:start position:0% +Voltage conversion I'm doing the more +energy storage I'm going to need to do + + align:start position:0% +energy storage I'm going to need to do + + + align:start position:0% +energy storage I'm going to need to do +it okay and the last thing which weighs + + align:start position:0% +it okay and the last thing which weighs + + + align:start position:0% +it okay and the last thing which weighs +heavily on a lot of designers Minds is + + align:start position:0% +heavily on a lot of designers Minds is + + + align:start position:0% +heavily on a lot of designers Minds is +uh we expressed it last time in terms of + + align:start position:0% +uh we expressed it last time in terms of + + + align:start position:0% +uh we expressed it last time in terms of +switching period here I'm expressing it + + align:start position:0% +switching period here I'm expressing it + + + align:start position:0% +switching period here I'm expressing it +in terms of the switching + + align:start position:0% +in terms of the switching + + + align:start position:0% +in terms of the switching +frequency um the energy storage gets + + align:start position:0% +frequency um the energy storage gets + + + align:start position:0% +frequency um the energy storage gets +smaller if I go to a higher switching + + align:start position:0% +smaller if I go to a higher switching + + + align:start position:0% +smaller if I go to a higher switching +frequency so usually I'd like to switch + + align:start position:0% +frequency so usually I'd like to switch + + + align:start position:0% +frequency so usually I'd like to switch +as fast as I can commensurate with other + + align:start position:0% +as fast as I can commensurate with other + + + align:start position:0% +as fast as I can commensurate with other +constraints right because my energy + + align:start position:0% +constraints right because my energy + + + align:start position:0% +constraints right because my energy +storage got smaller my components will + + align:start position:0% +storage got smaller my components will + + + align:start position:0% +storage got smaller my components will +then hopefully get smaller life is good + + align:start position:0% +then hopefully get smaller life is good + + + align:start position:0% +then hopefully get smaller life is good +so there's been always a lot of effort + + align:start position:0% +so there's been always a lot of effort + + + align:start position:0% +so there's been always a lot of effort +to go as high as a frequency you can + + align:start position:0% +to go as high as a frequency you can + + + align:start position:0% +to go as high as a frequency you can +until we run into some other limits and + + align:start position:0% +until we run into some other limits and + + + align:start position:0% +until we run into some other limits and +we'll talk about those limits loss being + + align:start position:0% +we'll talk about those limits loss being + + + align:start position:0% +we'll talk about those limits loss being +one of them okay and I will say that + + align:start position:0% +one of them okay and I will say that + + + align:start position:0% +one of them okay and I will say that +everything we just said about the + + align:start position:0% +everything we just said about the + + + align:start position:0% +everything we just said about the +capacitor we could say in the inductor + + align:start position:0% +capacitor we could say in the inductor + + + align:start position:0% +capacitor we could say in the inductor +and I should note that in this set of + + align:start position:0% +and I should note that in this set of + + + align:start position:0% +and I should note that in this set of +lectures notes I think I wrote 1 minus D + + align:start position:0% +lectures notes I think I wrote 1 minus D + + + align:start position:0% +lectures notes I think I wrote 1 minus D +here and this should be D which is is + + align:start position:0% +here and this should be D which is is + + + align:start position:0% +here and this should be D which is is +correct in the last set of leure notes + + align:start position:0% +correct in the last set of leure notes + + + align:start position:0% +correct in the last set of leure notes +okay but nonetheless the same ideas + + align:start position:0% +okay but nonetheless the same ideas + + + align:start position:0% +okay but nonetheless the same ideas +pertain smaller Ripple means larger + + align:start position:0% +pertain smaller Ripple means larger + + + align:start position:0% +pertain smaller Ripple means larger +energy storage requirement larger + + align:start position:0% +energy storage requirement larger + + + align:start position:0% +energy storage requirement larger +conversion ratio means larger energy + + align:start position:0% +conversion ratio means larger energy + + + align:start position:0% +conversion ratio means larger energy +storage requirement and higher frequency + + align:start position:0% +storage requirement and higher frequency + + + align:start position:0% +storage requirement and higher frequency +means lower energy storage requirements + + align:start position:0% +means lower energy storage requirements + + + align:start position:0% +means lower energy storage requirements +okay any questions about + + align:start position:0% + + + + align:start position:0% + +that okay I'd like to keep talking + + align:start position:0% +that okay I'd like to keep talking + + + align:start position:0% +that okay I'd like to keep talking +about this notion of um conversion and + + align:start position:0% +about this notion of um conversion and + + + align:start position:0% +about this notion of um conversion and +the Ripple you see in your converters + + align:start position:0% +the Ripple you see in your converters + + + align:start position:0% +the Ripple you see in your converters +because we haven't actually sort of + + align:start position:0% +because we haven't actually sort of + + + align:start position:0% +because we haven't actually sort of +gotten to all possible cases yet okay + + align:start position:0% +gotten to all possible cases yet okay + + + align:start position:0% +gotten to all possible cases yet okay +and let's just go think about this boost + + align:start position:0% +and let's just go think about this boost + + + align:start position:0% +and let's just go think about this boost +converter okay and what we'll do is + + align:start position:0% +converter okay and what we'll do is + + + align:start position:0% +converter okay and what we'll do is +let's think about the inductor current + + align:start position:0% +let's think about the inductor current + + + align:start position:0% +let's think about the inductor current +and I'll think about the inductor + + align:start position:0% +and I'll think about the inductor + + + align:start position:0% +and I'll think about the inductor +voltage vabel here okay so if I'm + + align:start position:0% +voltage vabel here okay so if I'm + + + align:start position:0% +voltage vabel here okay so if I'm +switching my converter right I'm going + + align:start position:0% +switching my converter right I'm going + + + align:start position:0% +switching my converter right I'm going +to have some switching signal which is + + align:start position:0% +to have some switching signal which is + + + align:start position:0% +to have some switching signal which is +driving you know which is telling when + + align:start position:0% +driving you know which is telling when + + + align:start position:0% +driving you know which is telling when +this gate is turning on and off okay so + + align:start position:0% +this gate is turning on and off okay so + + + align:start position:0% +this gate is turning on and off okay so +I'll have some switching + + align:start position:0% +I'll have some switching + + + align:start position:0% +I'll have some switching +function that's doing this right so it's + + align:start position:0% +function that's doing this right so it's + + + align:start position:0% +function that's doing this right so it's +high for sometime + + align:start position:0% +high for sometime + + + align:start position:0% +high for sometime +DT and then it's low for some time and + + align:start position:0% +DT and then it's low for some time and + + + align:start position:0% +DT and then it's low for some time and +then it's high for some time you know + + align:start position:0% +then it's high for some time you know + + + align:start position:0% +then it's high for some time you know +after a period okay and then I can say + + align:start position:0% +after a period okay and then I can say + + + align:start position:0% +after a period okay and then I can say +okay well what does my inductor voltage + + align:start position:0% +okay well what does my inductor voltage + + + align:start position:0% +okay well what does my inductor voltage +do during that + + align:start position:0% +do during that + + + align:start position:0% +do during that +time okay well my inductor voltage is + + align:start position:0% +time okay well my inductor voltage is + + + align:start position:0% +time okay well my inductor voltage is +positive at V1 when I turn the switch + + align:start position:0% +positive at V1 when I turn the switch + + + align:start position:0% +positive at V1 when I turn the switch +on okay so it looks like + + align:start position:0% +on okay so it looks like + + + align:start position:0% +on okay so it looks like +this at Value + + align:start position:0% +this at Value + + + align:start position:0% +this at Value +V1 and then when I turn the switch off I + + align:start position:0% +V1 and then when I turn the switch off I + + + align:start position:0% +V1 and then when I turn the switch off I +have V1 minus V2 across it and I get + + align:start position:0% +have V1 minus V2 across it and I get + + + align:start position:0% +have V1 minus V2 across it and I get +some negative + + align:start position:0% +some negative + + + align:start position:0% +some negative +voltage okay and what we know is that in + + align:start position:0% +voltage okay and what we know is that in + + + align:start position:0% +voltage okay and what we know is that in +periodic steady state this area + + align:start position:0% +periodic steady state this area + + + align:start position:0% +periodic steady state this area +must equal this + + align:start position:0% +must equal this + + + align:start position:0% +must equal this +area and this ends up being V1 minus + + align:start position:0% +area and this ends up being V1 minus + + + align:start position:0% +area and this ends up being V1 minus +V2 okay and if I were to plot the + + align:start position:0% +V2 okay and if I were to plot the + + + align:start position:0% +V2 okay and if I were to plot the +current okay in the inductor what would + + align:start position:0% +current okay in the inductor what would + + + align:start position:0% +current okay in the inductor what would +I + + align:start position:0% +I + + + align:start position:0% +I +see okay over this same time + + align:start position:0% +see okay over this same time + + + align:start position:0% +see okay over this same time +period right I have some DC + + align:start position:0% +period right I have some DC + + + align:start position:0% +period right I have some DC +value in the inductor current which is + + align:start position:0% +value in the inductor current which is + + + align:start position:0% +value in the inductor current which is +i1 right the DC input current here is + + align:start position:0% +i1 right the DC input current here is + + + align:start position:0% +i1 right the DC input current here is +the DC current coming from the + + align:start position:0% +the DC current coming from the + + + align:start position:0% +the DC current coming from the +source okay + + align:start position:0% +source okay + + + align:start position:0% +source okay +and that's my average value and what + + align:start position:0% +and that's my average value and what + + + align:start position:0% +and that's my average value and what +we'll have is in the first part of the + + align:start position:0% +we'll have is in the first part of the + + + align:start position:0% +we'll have is in the first part of the +cycle I store energy in the inductor and + + align:start position:0% +cycle I store energy in the inductor and + + + align:start position:0% +cycle I store energy in the inductor and +I get this positive triangular Ripple + + align:start position:0% +I get this positive triangular Ripple + + + align:start position:0% +I get this positive triangular Ripple +and in the second part of the cycle I + + align:start position:0% +and in the second part of the cycle I + + + align:start position:0% +and in the second part of the cycle I +get negative slope and I have my + + align:start position:0% +get negative slope and I have my + + + align:start position:0% +get negative slope and I have my +periodic steady state waveform like this + + align:start position:0% +periodic steady state waveform like this + + + align:start position:0% +periodic steady state waveform like this +and this is + + align:start position:0% + + + + align:start position:0% + +Delta I Peak to + + align:start position:0% +Delta I Peak to + + + align:start position:0% +Delta I Peak to +Peak okay so that that's what our + + align:start position:0% +Peak okay so that that's what our + + + align:start position:0% +Peak okay so that that's what our +waveforms look + + align:start position:0% +waveforms look + + + align:start position:0% +waveforms look +like okay so let's think about this in + + align:start position:0% +like okay so let's think about this in + + + align:start position:0% +like okay so let's think about this in +terms of Ripple ratio okay so what do I + + align:start position:0% +terms of Ripple ratio okay so what do I + + + align:start position:0% +terms of Ripple ratio okay so what do I +know um Delta i l Peak to + + align:start position:0% + + + + align:start position:0% + +Peak is you know Delta I is V over L + + align:start position:0% +Peak is you know Delta I is V over L + + + align:start position:0% +Peak is you know Delta I is V over L +delta T right so V is V1 + + align:start position:0% + + + + align:start position:0% + +/ L time + + align:start position:0% +/ L time + + + align:start position:0% +/ L time +GT right so this is an expression of how + + align:start position:0% +GT right so this is an expression of how + + + align:start position:0% +GT right so this is an expression of how +much I Rise I'm applying V1 for time DT + + align:start position:0% +much I Rise I'm applying V1 for time DT + + + align:start position:0% +much I Rise I'm applying V1 for time DT +so the Delta is V1 over L + + align:start position:0% +so the Delta is V1 over L + + + align:start position:0% +so the Delta is V1 over L +DT + + align:start position:0% +DT + + + align:start position:0% +DT +okay what is the input current + + align:start position:0% +okay what is the input current + + + align:start position:0% +okay what is the input current +i1 okay what what's i1 going to be well + + align:start position:0% +i1 okay what what's i1 going to be well + + + align:start position:0% +i1 okay what what's i1 going to be well +um the the DC output current is going to + + align:start position:0% +um the the DC output current is going to + + + align:start position:0% +um the the DC output current is going to +be V2 / by whatever this resistor is + + align:start position:0% +be V2 / by whatever this resistor is + + + align:start position:0% +be V2 / by whatever this resistor is +right so if I wanted I2 I would have + + align:start position:0% +right so if I wanted I2 I would have + + + align:start position:0% +right so if I wanted I2 I would have +V2 ID R but this is I2 how does I2 + + align:start position:0% +V2 ID R but this is I2 how does I2 + + + align:start position:0% +V2 ID R but this is I2 how does I2 +relate to i1 I I2 is going to be i1 over + + align:start position:0% +relate to i1 I I2 is going to be i1 over + + + align:start position:0% +relate to i1 I I2 is going to be i1 over +1 minus + + align:start position:0% +1 minus + + + align:start position:0% +1 minus +d + + align:start position:0% + + + + align:start position:0% + +right because i1 is bigger than I2 right + + align:start position:0% +right because i1 is bigger than I2 right + + + align:start position:0% +right because i1 is bigger than I2 right +that's just this is + + align:start position:0% +that's just this is + + + align:start position:0% +that's just this is +you know this factor is I2 and then this + + align:start position:0% +you know this factor is I2 and then this + + + align:start position:0% +you know this factor is I2 and then this +gives me 1 over 1 minus D gives me the + + align:start position:0% +gives me 1 over 1 minus D gives me the + + + align:start position:0% +gives me 1 over 1 minus D gives me the +conversion to i1 okay any question about + + align:start position:0% + + + + align:start position:0% + +that so then if I were to write the + + align:start position:0% +that so then if I were to write the + + + align:start position:0% +that so then if I were to write the +Ripple + + align:start position:0% +Ripple + + + align:start position:0% +Ripple +ratio right the Ripple ratio in the + + align:start position:0% +ratio right the Ripple ratio in the + + + align:start position:0% +ratio right the Ripple ratio in the +inductor in this example is simply equal + + align:start position:0% +inductor in this example is simply equal + + + align:start position:0% +inductor in this example is simply equal +to Delta I Peak to Peak over two divid + + align:start position:0% +to Delta I Peak to Peak over two divid + + + align:start position:0% +to Delta I Peak to Peak over two divid +by i + + align:start position:0% +by i + + + align:start position:0% +by i +l and this is also equal to I + + align:start position:0% +l and this is also equal to I + + + align:start position:0% +l and this is also equal to I +right and so this is going to give me V1 + + align:start position:0% +right and so this is going to give me V1 + + + align:start position:0% +right and so this is going to give me V1 +DT over + + align:start position:0% +DT over + + + align:start position:0% +DT over +l so this is going to be um 2 l i + + align:start position:0% +l so this is going to be um 2 l i + + + align:start position:0% +l so this is going to be um 2 l i +subel is um + + align:start position:0% +subel is um + + + align:start position:0% +subel is um +V2 R * 1us + + align:start position:0% +V2 R * 1us + + + align:start position:0% +V2 R * 1us +D + + align:start position:0% +D + + + align:start position:0% +D +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and I can um rewrite this + + align:start position:0% +and I can um rewrite this + + + align:start position:0% +and I can um rewrite this +um in terms + + align:start position:0% + + + + align:start position:0% + +of I can get rid of um V1 and V2 here + + align:start position:0% +of I can get rid of um V1 and V2 here + + + align:start position:0% +of I can get rid of um V1 and V2 here +why because V2 + + align:start position:0% +why because V2 + + + align:start position:0% +why because V2 +of V2 is going to be V1 over 1 minus D + + align:start position:0% +of V2 is going to be V1 over 1 minus D + + + align:start position:0% +of V2 is going to be V1 over 1 minus D +so I could rewrite this at V1 over 1 + + align:start position:0% +so I could rewrite this at V1 over 1 + + + align:start position:0% +so I could rewrite this at V1 over 1 +minus D is + + align:start position:0% +minus D is + + + align:start position:0% +minus D is +V2 or V2 * 1 - D is V1 so I could + + align:start position:0% +V2 or V2 * 1 - D is V1 so I could + + + align:start position:0% +V2 or V2 * 1 - D is V1 so I could +rewrite this as d + + align:start position:0% +rewrite this as d + + + align:start position:0% +rewrite this as d +* 1 - d^ + + align:start position:0% + + + + align:start position:0% + +2 t + + align:start position:0% +2 t + + + align:start position:0% +2 t +r over 2 + + align:start position:0% +r over 2 + + + align:start position:0% +r over 2 +L + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +um and what does this tell + + align:start position:0% +um and what does this tell + + + align:start position:0% +um and what does this tell +me + + align:start position:0% +me + + + align:start position:0% +me +well this says how you know essentially + + align:start position:0% +well this says how you know essentially + + + align:start position:0% +well this says how you know essentially +I'm asking what's this Ripple compared + + align:start position:0% +I'm asking what's this Ripple compared + + + align:start position:0% +I'm asking what's this Ripple compared +to the average value of my current right + + align:start position:0% +to the average value of my current right + + + align:start position:0% +to the average value of my current right +and we can see that the Ripple ratio + + align:start position:0% +and we can see that the Ripple ratio + + + align:start position:0% +and we can see that the Ripple ratio +goes + + align:start position:0% +goes + + + align:start position:0% +goes +up as what it goes up when either R goes + + align:start position:0% +up as what it goes up when either R goes + + + align:start position:0% +up as what it goes up when either R goes +up + + align:start position:0% +up + + + align:start position:0% +up +or L goes + + align:start position:0% +or L goes + + + align:start position:0% +or L goes +down all right those are two things that + + align:start position:0% +down all right those are two things that + + + align:start position:0% +down all right those are two things that +will make the Ripple ratio bigger right + + align:start position:0% +will make the Ripple ratio bigger right + + + align:start position:0% +will make the Ripple ratio bigger right +and that makes sense right + + align:start position:0% +and that makes sense right + + + align:start position:0% +and that makes sense right +it making L smaller is going to make the + + align:start position:0% +it making L smaller is going to make the + + + align:start position:0% +it making L smaller is going to make the +Ripple ratio bigger because I have a + + align:start position:0% +Ripple ratio bigger because I have a + + + align:start position:0% +Ripple ratio bigger because I have a +higher Ripple on the + + align:start position:0% +higher Ripple on the + + + align:start position:0% +higher Ripple on the +inductor okay any questions about + + align:start position:0% +inductor okay any questions about + + + align:start position:0% +inductor okay any questions about +that yeah the DC values of the currents + + align:start position:0% +that yeah the DC values of the currents + + + align:start position:0% +that yeah the DC values of the currents +are + + align:start position:0% +are + + + align:start position:0% +are +L uh the DC vales are ignoring loss yeah + + align:start position:0% +L uh the DC vales are ignoring loss yeah + + + align:start position:0% +L uh the DC vales are ignoring loss yeah +there's no loss this is a perfect + + align:start position:0% +there's no loss this is a perfect + + + align:start position:0% +there's no loss this is a perfect +converter everything's lossless yeah you + + align:start position:0% +converter everything's lossless yeah you + + + align:start position:0% +converter everything's lossless yeah you +throw in loss and things happen right + + align:start position:0% +throw in loss and things happen right + + + align:start position:0% +throw in loss and things happen right +right now I'm treating everything as + + align:start position:0% +right now I'm treating everything as + + + align:start position:0% +right now I'm treating everything as +being perfect + + align:start position:0% + + + + align:start position:0% + +so let's start to think about the impact + + align:start position:0% +so let's start to think about the impact + + + align:start position:0% +so let's start to think about the impact +of changing sort of + + align:start position:0% +of changing sort of + + + align:start position:0% +of changing sort of +um + + align:start position:0% +um + + + align:start position:0% +um +resistance and inductance so let me + + align:start position:0% +resistance and inductance so let me + + + align:start position:0% +resistance and inductance so let me +replot this so let me plot I again + + align:start position:0% + + + + align:start position:0% + +right okay and we said okay maybe I have + + align:start position:0% +right okay and we said okay maybe I have + + + align:start position:0% +right okay and we said okay maybe I have +some average + + align:start position:0% +some average + + + align:start position:0% +some average +value and I have some Ripple that does + + align:start position:0% + + + + align:start position:0% + +this and so forth okay and this is at + + align:start position:0% +this and so forth okay and this is at + + + align:start position:0% +this and so forth okay and this is at +some resistance value what would happen + + align:start position:0% +some resistance value what would happen + + + align:start position:0% +some resistance value what would happen +if I increase my resistance + + align:start position:0% +if I increase my resistance + + + align:start position:0% +if I increase my resistance +value okay well up here I see if I + + align:start position:0% +value okay well up here I see if I + + + align:start position:0% +value okay well up here I see if I +increase my resistance value I increase + + align:start position:0% +increase my resistance value I increase + + + align:start position:0% +increase my resistance value I increase +the Ripple ratio but how does it change + + align:start position:0% +the Ripple ratio but how does it change + + + align:start position:0% +the Ripple ratio but how does it change +the IL waveforms this is I okay but if I + + align:start position:0% +the IL waveforms this is I okay but if I + + + align:start position:0% +the IL waveforms this is I okay but if I +used a bigger resistance value what + + align:start position:0% +used a bigger resistance value what + + + align:start position:0% +used a bigger resistance value what +might happen happens it might look like + + align:start position:0% +might happen happens it might look like + + + align:start position:0% +might happen happens it might look like +this I will have some lower current + + align:start position:0% +this I will have some lower current + + + align:start position:0% +this I will have some lower current +right to supply the same + + align:start position:0% +right to supply the same + + + align:start position:0% +right to supply the same +voltage at the + + align:start position:0% +voltage at the + + + align:start position:0% +voltage at the +output if I if I doubled my resistance I + + align:start position:0% +output if I if I doubled my resistance I + + + align:start position:0% +output if I if I doubled my resistance I +need have the current half the current + + align:start position:0% +need have the current half the current + + + align:start position:0% +need have the current half the current +to get to the same output voltage if my + + align:start position:0% +to get to the same output voltage if my + + + align:start position:0% +to get to the same output voltage if my +output current halves my input current + + align:start position:0% +output current halves my input current + + + align:start position:0% +output current halves my input current +halves and that means my inductor + + align:start position:0% +halves and that means my inductor + + + align:start position:0% +halves and that means my inductor +current on average halves so okay I get + + align:start position:0% +current on average halves so okay I get + + + align:start position:0% +current on average halves so okay I get +I reduced the average inductor current + + align:start position:0% +I reduced the average inductor current + + + align:start position:0% +I reduced the average inductor current +but V1 and V2 have stayed the same right + + align:start position:0% +but V1 and V2 have stayed the same right + + + align:start position:0% +but V1 and V2 have stayed the same right +and if V1 and V2 have stayed the same + + align:start position:0% +and if V1 and V2 have stayed the same + + + align:start position:0% +and if V1 and V2 have stayed the same +the slope on the Ripple is stayed the + + align:start position:0% +the slope on the Ripple is stayed the + + + align:start position:0% +the slope on the Ripple is stayed the +same right so my inductor current at a + + align:start position:0% +same right so my inductor current at a + + + align:start position:0% +same right so my inductor current at a +higher resistance might look like this + + align:start position:0% +higher resistance might look like this + + + align:start position:0% +higher resistance might look like this +okay this is parallel this is parallel + + align:start position:0% +okay this is parallel this is parallel + + + align:start position:0% +okay this is parallel this is parallel +and so forth and I get this so this is i + + align:start position:0% +and so forth and I get this so this is i + + + align:start position:0% +and so forth and I get this so this is i +l you know this is I at R + + align:start position:0% + + + + align:start position:0% + +small this is I at RL medium + + align:start position:0% + + + + align:start position:0% + +what would happen if I kept increasing + + align:start position:0% +what would happen if I kept increasing + + + align:start position:0% +what would happen if I kept increasing +my resistance value well all we saw is + + align:start position:0% +my resistance value well all we saw is + + + align:start position:0% +my resistance value well all we saw is +the waveform doesn't the waveform shape + + align:start position:0% +the waveform doesn't the waveform shape + + + align:start position:0% +the waveform doesn't the waveform shape +just doesn't change the average just + + align:start position:0% +just doesn't change the average just + + + align:start position:0% +just doesn't change the average just +moves down right the Ripple is the same + + align:start position:0% +moves down right the Ripple is the same + + + align:start position:0% +moves down right the Ripple is the same +but the DC value is changing because I + + align:start position:0% +but the DC value is changing because I + + + align:start position:0% +but the DC value is changing because I +need more or less average current to + + align:start position:0% +need more or less average current to + + + align:start position:0% +need more or less average current to +support the output and more or less + + align:start position:0% +support the output and more or less + + + align:start position:0% +support the output and more or less +average power draw to support the + + align:start position:0% +average power draw to support the + + + align:start position:0% +average power draw to support the +output So eventually what's going to + + align:start position:0% +output So eventually what's going to + + + align:start position:0% +output So eventually what's going to +happen is we're going to get something + + align:start position:0% +happen is we're going to get something + + + align:start position:0% +happen is we're going to get something +that we hit another mode of operation + + align:start position:0% +that we hit another mode of operation + + + align:start position:0% +that we hit another mode of operation +we're going to get something where does + + align:start position:0% +we're going to get something where does + + + align:start position:0% +we're going to get something where does +this I'm going to turn my switch + + align:start position:0% +this I'm going to turn my switch + + + align:start position:0% +this I'm going to turn my switch +on and then it's going to come + + align:start position:0% + + + + align:start position:0% + +down and then + + align:start position:0% +down and then + + + align:start position:0% +down and then +stop okay so here this is supposed to be + + align:start position:0% +stop okay so here this is supposed to be + + + align:start position:0% +stop okay so here this is supposed to be +the same + + align:start position:0% +the same + + + align:start position:0% +the same +DT okay and here's the same + + align:start position:0% +DT okay and here's the same + + + align:start position:0% +DT okay and here's the same +T okay but I'm going to get this time + + align:start position:0% +T okay but I'm going to get this time + + + align:start position:0% +T okay but I'm going to get this time +period where the current comes down to + + align:start position:0% +period where the current comes down to + + + align:start position:0% +period where the current comes down to +zero now why am I not drawing the + + align:start position:0% +zero now why am I not drawing the + + + align:start position:0% +zero now why am I not drawing the +current is going negative + + align:start position:0% + + + + align:start position:0% + +I can't really get a negative current + + align:start position:0% +I can't really get a negative current + + + align:start position:0% +I can't really get a negative current +through the diode right so once the + + align:start position:0% +through the diode right so once the + + + align:start position:0% +through the diode right so once the +inductor current ramps down to zero the + + align:start position:0% +inductor current ramps down to zero the + + + align:start position:0% +inductor current ramps down to zero the +diode's going to turn off whereas the + + align:start position:0% +diode's going to turn off whereas the + + + align:start position:0% +diode's going to turn off whereas the +diode was conducting before okay so I + + align:start position:0% +diode was conducting before okay so I + + + align:start position:0% +diode was conducting before okay so I +could build a converter where this was + + align:start position:0% +could build a converter where this was + + + align:start position:0% +could build a converter where this was +an active switch and Allowed by + + align:start position:0% +an active switch and Allowed by + + + align:start position:0% +an active switch and Allowed by +directional current and people do that + + align:start position:0% +directional current and people do that + + + align:start position:0% +directional current and people do that +but if I'm going to build it with a + + align:start position:0% +but if I'm going to build it with a + + + align:start position:0% +but if I'm going to build it with a +diode I'm going to get this alternative + + align:start position:0% +diode I'm going to get this alternative + + + align:start position:0% +diode I'm going to get this alternative +State okay so in this alternative state + + align:start position:0% +State okay so in this alternative state + + + align:start position:0% +State okay so in this alternative state +right what do I have in this Ty here I + + align:start position:0% +right what do I have in this Ty here I + + + align:start position:0% +right what do I have in this Ty here I +have the switch + + align:start position:0% + + + + align:start position:0% + +on here I have the diode + + align:start position:0% +on here I have the diode + + + align:start position:0% +on here I have the diode +on okay and in this time period + + align:start position:0% +on okay and in this time period + + + align:start position:0% +on okay and in this time period +everything is + + align:start position:0% + + + + align:start position:0% + +off okay so we haven't considered this + + align:start position:0% +off okay so we haven't considered this + + + align:start position:0% +off okay so we haven't considered this +mode of operation right we always + + align:start position:0% +mode of operation right we always + + + align:start position:0% +mode of operation right we always +assumed it was either the switch or the + + align:start position:0% +assumed it was either the switch or the + + + align:start position:0% +assumed it was either the switch or the +diode that was + + align:start position:0% +diode that was + + + align:start position:0% +diode that was +conducting now I'm telling you hey if I + + align:start position:0% +conducting now I'm telling you hey if I + + + align:start position:0% +conducting now I'm telling you hey if I +make R big + + align:start position:0% + + + + align:start position:0% + +and how big is Big we'll get into that + + align:start position:0% +and how big is Big we'll get into that + + + align:start position:0% +and how big is Big we'll get into that +but if I make RL big enough the average + + align:start position:0% +but if I make RL big enough the average + + + align:start position:0% +but if I make RL big enough the average +current goes down to the fact that my + + align:start position:0% +current goes down to the fact that my + + + align:start position:0% +current goes down to the fact that my +current Ripple is going to make me hit + + align:start position:0% +current Ripple is going to make me hit + + + align:start position:0% +current Ripple is going to make me hit +zero current and I'm going to get this + + align:start position:0% +zero current and I'm going to get this + + + align:start position:0% +zero current and I'm going to get this +new kind of funny + + align:start position:0% +new kind of funny + + + align:start position:0% +new kind of funny +state does that make sense to + + align:start position:0% +state does that make sense to + + + align:start position:0% +state does that make sense to +everybody so this is what happens with + + align:start position:0% +everybody so this is what happens with + + + align:start position:0% +everybody so this is what happens with +variations with + + align:start position:0% +variations with + + + align:start position:0% +variations with +resistance + + align:start position:0% +resistance + + + align:start position:0% +resistance +okay what happens with variations in + + align:start position:0% +okay what happens with variations in + + + align:start position:0% +okay what happens with variations in +inductance well slightly + + align:start position:0% +inductance well slightly + + + align:start position:0% +inductance well slightly +different okay maybe what I have is this + + align:start position:0% +different okay maybe what I have is this + + + align:start position:0% +different okay maybe what I have is this +okay I will have again um some value + + align:start position:0% + + + + align:start position:0% + +I maybe this actually maybe maybe make + + align:start position:0% +I maybe this actually maybe maybe make + + + align:start position:0% +I maybe this actually maybe maybe make +it a little smaller I have some average + + align:start position:0% +it a little smaller I have some average + + + align:start position:0% +it a little smaller I have some average +value of I that I'm generating and if I + + align:start position:0% +value of I that I'm generating and if I + + + align:start position:0% +value of I that I'm generating and if I +have some big inductance maybe my ripple + + align:start position:0% +have some big inductance maybe my ripple + + + align:start position:0% +have some big inductance maybe my ripple +is small so it does this + + align:start position:0% + + + + align:start position:0% + +right so this is i l l + + align:start position:0% +right so this is i l l + + + align:start position:0% +right so this is i l l +big right have a big inductance in there + + align:start position:0% +big right have a big inductance in there + + + align:start position:0% +big right have a big inductance in there +the Ripple's relatively + + align:start position:0% +the Ripple's relatively + + + align:start position:0% +the Ripple's relatively +small if I got a bit smaller inductor I + + align:start position:0% +small if I got a bit smaller inductor I + + + align:start position:0% +small if I got a bit smaller inductor I +I turn off my converter I pull out one + + align:start position:0% +I turn off my converter I pull out one + + + align:start position:0% +I turn off my converter I pull out one +inductor I put in a new inductor that's + + align:start position:0% +inductor I put in a new inductor that's + + + align:start position:0% +inductor I put in a new inductor that's +half the value what would happen well + + align:start position:0% +half the value what would happen well + + + align:start position:0% +half the value what would happen well +the Ripple would increase right and I + + align:start position:0% +the Ripple would increase right and I + + + align:start position:0% +the Ripple would increase right and I +would get something that did + + align:start position:0% +would get something that did + + + align:start position:0% +would get something that did +this right the Delta I Peak to Peak is + + align:start position:0% +this right the Delta I Peak to Peak is + + + align:start position:0% +this right the Delta I Peak to Peak is +inversely proportional to L so my ripple + + align:start position:0% +inversely proportional to L so my ripple + + + align:start position:0% +inversely proportional to L so my ripple +current would in was a terrible drawing + + align:start position:0% +current would in was a terrible drawing + + + align:start position:0% +current would in was a terrible drawing +my ripple current would + + align:start position:0% +my ripple current would + + + align:start position:0% +my ripple current would +increase + + align:start position:0% +increase + + + align:start position:0% +increase +okay if I turn the converter off and + + align:start position:0% +okay if I turn the converter off and + + + align:start position:0% +okay if I turn the converter off and +then I put in even a smaller inductor + + align:start position:0% +then I put in even a smaller inductor + + + align:start position:0% +then I put in even a smaller inductor +what would happen if I get a really + + align:start position:0% +what would happen if I get a really + + + align:start position:0% +what would happen if I get a really +small inductor I pull a smallest + + align:start position:0% +small inductor I pull a smallest + + + align:start position:0% +small inductor I pull a smallest +inductor I can find in my kit maybe I + + align:start position:0% +inductor I can find in my kit maybe I + + + align:start position:0% +inductor I can find in my kit maybe I +get a waveform that does + + align:start position:0% +get a waveform that does + + + align:start position:0% +get a waveform that does +this starts at zero comes down hits zero + + align:start position:0% +this starts at zero comes down hits zero + + + align:start position:0% +this starts at zero comes down hits zero +and then stays at zero okay so I'm going + + align:start position:0% +and then stays at zero okay so I'm going + + + align:start position:0% +and then stays at zero okay so I'm going +to get a again a case where um I have + + align:start position:0% +to get a again a case where um I have + + + align:start position:0% +to get a again a case where um I have +the diode + + align:start position:0% +the diode + + + align:start position:0% +the diode +on and then I have I'm sorry I have the + + align:start position:0% +on and then I have I'm sorry I have the + + + align:start position:0% +on and then I have I'm sorry I have the +switch + + align:start position:0% +switch + + + align:start position:0% +switch +on in this case and this is only + + align:start position:0% +on in this case and this is only + + + align:start position:0% +on in this case and this is only +pertaining to this bottom picture the + + align:start position:0% +pertaining to this bottom picture the + + + align:start position:0% +pertaining to this bottom picture the +diode's + + align:start position:0% +diode's + + + align:start position:0% +diode's +on and then I get a time period where + + align:start position:0% +on and then I get a time period where + + + align:start position:0% +on and then I get a time period where +both are + + align:start position:0% + + + + align:start position:0% + +off okay and this is a different mode of + + align:start position:0% +off okay and this is a different mode of + + + align:start position:0% +off okay and this is a different mode of +operation + + align:start position:0% + + + + align:start position:0% + +any questions about + + align:start position:0% + + + + align:start position:0% + +that this is + + align:start position:0% +that this is + + + align:start position:0% +that this is +um this mode of + + align:start position:0% +um this mode of + + + align:start position:0% +um this mode of +operation uh is known as discontinuous + + align:start position:0% +operation uh is known as discontinuous + + + align:start position:0% +operation uh is known as discontinuous +conduction + + align:start position:0% + + + + align:start position:0% + +mode it's often abbreviated DCM + + align:start position:0% +mode it's often abbreviated DCM + + + align:start position:0% +mode it's often abbreviated DCM +okay now when we say discontinuous + + align:start position:0% +okay now when we say discontinuous + + + align:start position:0% +okay now when we say discontinuous +there's nothing discontinuous about the + + align:start position:0% +there's nothing discontinuous about the + + + align:start position:0% +there's nothing discontinuous about the +inductor current obviously the inductor + + align:start position:0% +inductor current obviously the inductor + + + align:start position:0% +inductor current obviously the inductor +current is always a continuous waveform + + align:start position:0% +current is always a continuous waveform + + + align:start position:0% +current is always a continuous waveform +but what it's what's meant by that is + + align:start position:0% +but what it's what's meant by that is + + + align:start position:0% +but what it's what's meant by that is +it's not continuously flowing positive + + align:start position:0% +it's not continuously flowing positive + + + align:start position:0% +it's not continuously flowing positive +and negative right it it has this third + + align:start position:0% +and negative right it it has this third + + + align:start position:0% +and negative right it it has this third +state where both devices are off okay + + align:start position:0% +state where both devices are off okay + + + align:start position:0% +state where both devices are off okay +and keep in mind that that's all the + + align:start position:0% +and keep in mind that that's all the + + + align:start position:0% +and keep in mind that that's all the +possible cases because I cannot have a + + align:start position:0% +possible cases because I cannot have a + + + align:start position:0% +possible cases because I cannot have a +case where both the switch and the diode + + align:start position:0% +case where both the switch and the diode + + + align:start position:0% +case where both the switch and the diode +are on the voltage is positive right + + align:start position:0% +are on the voltage is positive right + + + align:start position:0% +are on the voltage is positive right +that can't exist so we sort of exercise + + align:start position:0% +that can't exist so we sort of exercise + + + align:start position:0% +that can't exist so we sort of exercise +all the things that can + + align:start position:0% +all the things that can + + + align:start position:0% +all the things that can +happen right any questions about + + align:start position:0% + + + + align:start position:0% + +that so when does this + + align:start position:0% +that so when does this + + + align:start position:0% +that so when does this +happen well right the Ripple ratio like + + align:start position:0% +happen well right the Ripple ratio like + + + align:start position:0% +happen well right the Ripple ratio like +if I were right at the edge of + + align:start position:0% +if I were right at the edge of + + + align:start position:0% +if I were right at the edge of +discontinuous conduction right you could + + align:start position:0% +discontinuous conduction right you could + + + align:start position:0% +discontinuous conduction right you could +imagine a situation where I pick some + + align:start position:0% +imagine a situation where I pick some + + + align:start position:0% +imagine a situation where I pick some +intermediate + + align:start position:0% +intermediate + + + align:start position:0% +intermediate +value + + align:start position:0% +value + + + align:start position:0% +value +of resistance for example in this case + + align:start position:0% +of resistance for example in this case + + + align:start position:0% +of resistance for example in this case +where it go does exactly + + align:start position:0% + + + + align:start position:0% + +this right that oops I didn't draw that + + align:start position:0% +this right that oops I didn't draw that + + + align:start position:0% +this right that oops I didn't draw that +very + + align:start position:0% +very + + + align:start position:0% +very +well right I'm sitting right at the edge + + align:start position:0% +well right I'm sitting right at the edge + + + align:start position:0% +well right I'm sitting right at the edge +right where yes my waveforms are + + align:start position:0% +right where yes my waveforms are + + + align:start position:0% +right where yes my waveforms are +continuous my my diode never turns off + + align:start position:0% +continuous my my diode never turns off + + + align:start position:0% +continuous my my diode never turns off +but only barely so right in that case + + align:start position:0% +but only barely so right in that case + + + align:start position:0% +but only barely so right in that case +the peak to Peak Ripple is exactly twice + + align:start position:0% +the peak to Peak Ripple is exactly twice + + + align:start position:0% +the peak to Peak Ripple is exactly twice +the average current or this case is + + align:start position:0% +the average current or this case is + + + align:start position:0% +the average current or this case is +Ripple ratio equal to + + align:start position:0% +Ripple ratio equal to + + + align:start position:0% +Ripple ratio equal to +one okay it's Rippling up from zero to + + align:start position:0% +one okay it's Rippling up from zero to + + + align:start position:0% +one okay it's Rippling up from zero to +twice the average and back down to zero + + align:start position:0% +twice the average and back down to zero + + + align:start position:0% +twice the average and back down to zero +it's still a triangle wave it's not this + + align:start position:0% +it's still a triangle wave it's not this + + + align:start position:0% +it's still a triangle wave it's not this +funny clipped triangle wave it's still a + + align:start position:0% +funny clipped triangle wave it's still a + + + align:start position:0% +funny clipped triangle wave it's still a +pure triangle wave and that's exactly + + align:start position:0% +pure triangle wave and that's exactly + + + align:start position:0% +pure triangle wave and that's exactly +the Ripple ratio equal to one case does + + align:start position:0% +the Ripple ratio equal to one case does + + + align:start position:0% +the Ripple ratio equal to one case does +that make sense + + align:start position:0% +that make sense + + + align:start position:0% +that make sense +everybody so what do I get from + + align:start position:0% +everybody so what do I get from + + + align:start position:0% +everybody so what do I get from +that well + + align:start position:0% +that well + + + align:start position:0% +that well +we can come back and just calculate what + + align:start position:0% +we can come back and just calculate what + + + align:start position:0% +we can come back and just calculate what +happens I have my expression for ripple + + align:start position:0% +happens I have my expression for ripple + + + align:start position:0% +happens I have my expression for ripple +ratio is equal to one so I can write + + align:start position:0% +ratio is equal to one so I can write + + + align:start position:0% +ratio is equal to one so I can write +that again here I get R subel is equal + + align:start position:0% +that again here I get R subel is equal + + + align:start position:0% +that again here I get R subel is equal +to + + align:start position:0% +to + + + align:start position:0% +to +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +D * 1 - d^ 2 TR r/ + + align:start position:0% + + + + align:start position:0% + +2L and that's equal to one at the edge + + align:start position:0% +2L and that's equal to one at the edge + + + align:start position:0% +2L and that's equal to one at the edge +of DCM + + align:start position:0% + + + + align:start position:0% + +right that's where I transition between + + align:start position:0% +right that's where I transition between + + + align:start position:0% +right that's where I transition between +the two + + align:start position:0% +the two + + + align:start position:0% +the two +modes okay so from this we can say the + + align:start position:0% +modes okay so from this we can say the + + + align:start position:0% +modes okay so from this we can say the +DCM happens + + align:start position:0% +DCM happens + + + align:start position:0% +DCM happens +for R is greater + + align:start position:0% +for R is greater + + + align:start position:0% +for R is greater +than uh + + align:start position:0% +than uh + + + align:start position:0% +than uh +2L over D * 1 - d^ + + align:start position:0% +2L over D * 1 - d^ + + + align:start position:0% +2L over D * 1 - d^ + + align:start position:0% + + + + align:start position:0% + +uh t + + align:start position:0% +uh t + + + align:start position:0% +uh t +right + + align:start position:0% +right + + + align:start position:0% +right +or for L is less + + align:start position:0% +or for L is less + + + align:start position:0% +or for L is less +than + + align:start position:0% +than + + + align:start position:0% +than +um D * 1 - d^ 2 + + align:start position:0% +um D * 1 - d^ 2 + + + align:start position:0% +um D * 1 - d^ 2 +T r/ + + align:start position:0% +T r/ + + + align:start position:0% +T r/ +2 okay this is sometimes this value of + + align:start position:0% +2 okay this is sometimes this value of + + + align:start position:0% +2 okay this is sometimes this value of +L okay is sometimes called the critical + + align:start position:0% +L okay is sometimes called the critical + + + align:start position:0% +L okay is sometimes called the critical +inductance in the literature there's + + align:start position:0% +inductance in the literature there's + + + align:start position:0% +inductance in the literature there's +nothing very critical about it but all + + align:start position:0% +nothing very critical about it but all + + + align:start position:0% +nothing very critical about it but all +it's saying is if I go out and pick a + + align:start position:0% +it's saying is if I go out and pick a + + + align:start position:0% +it's saying is if I go out and pick a +big inductor bigger than this for the + + align:start position:0% +big inductor bigger than this for the + + + align:start position:0% +big inductor bigger than this for the +specified operating conditions I'm not + + align:start position:0% +specified operating conditions I'm not + + + align:start position:0% +specified operating conditions I'm not +going to run into discontinuous + + align:start position:0% +going to run into discontinuous + + + align:start position:0% +going to run into discontinuous +conduction + + align:start position:0% +conduction + + + align:start position:0% +conduction +okay but understand in a lot of cases + + align:start position:0% +okay but understand in a lot of cases + + + align:start position:0% +okay but understand in a lot of cases +you for some operating mode you're going + + align:start position:0% +you for some operating mode you're going + + + align:start position:0% +you for some operating mode you're going +to have to run into discontinuous + + align:start position:0% +to have to run into discontinuous + + + align:start position:0% +to have to run into discontinuous +conduction why because think about it + + align:start position:0% +conduction why because think about it + + + align:start position:0% +conduction why because think about it +this + + align:start position:0% +this + + + align:start position:0% +this +way I have to run for different load + + align:start position:0% +way I have to run for different load + + + align:start position:0% +way I have to run for different load +resistances right nobody I mean mostly + + align:start position:0% +resistances right nobody I mean mostly + + + align:start position:0% +resistances right nobody I mean mostly +in a power converter right you build a + + align:start position:0% +in a power converter right you build a + + + align:start position:0% +in a power converter right you build a +converter and then people hook loads up + + align:start position:0% +converter and then people hook loads up + + + align:start position:0% +converter and then people hook loads up +up to it you don't know what load they + + align:start position:0% +up to it you don't know what load they + + + align:start position:0% +up to it you don't know what load they +hook up to it right there's some maximum + + align:start position:0% +hook up to it right there's some maximum + + + align:start position:0% +hook up to it right there's some maximum +power rating but maybe they want to put + + align:start position:0% +power rating but maybe they want to put + + + align:start position:0% +power rating but maybe they want to put +very little load on it sometimes right + + align:start position:0% +very little load on it sometimes right + + + align:start position:0% +very little load on it sometimes right +maybe sometimes your microprocessor is + + align:start position:0% +maybe sometimes your microprocessor is + + + align:start position:0% +maybe sometimes your microprocessor is +running maybe sometimes it's not right + + align:start position:0% +running maybe sometimes it's not right + + + align:start position:0% +running maybe sometimes it's not right +and so you might have to deal with a + + align:start position:0% +and so you might have to deal with a + + + align:start position:0% +and so you might have to deal with a +very wide range of load currents up to + + align:start position:0% +very wide range of load currents up to + + + align:start position:0% +very wide range of load currents up to +some Maximum well if you have to deal + + align:start position:0% +some Maximum well if you have to deal + + + align:start position:0% +some Maximum well if you have to deal +with a very high load resistance or a + + align:start position:0% +with a very high load resistance or a + + + align:start position:0% +with a very high load resistance or a +very low load or a light load that means + + align:start position:0% +very low load or a light load that means + + + align:start position:0% +very low load or a light load that means +you're average is going to come down and + + align:start position:0% +you're average is going to come down and + + + align:start position:0% +you're average is going to come down and +down and down and the only way to keep + + align:start position:0% +down and down and the only way to keep + + + align:start position:0% +down and down and the only way to keep +it into CCM would be to use smaller + + align:start position:0% +it into CCM would be to use smaller + + + align:start position:0% +it into CCM would be to use smaller +smaller and smaller Ripple so you never + + align:start position:0% +smaller and smaller Ripple so you never + + + align:start position:0% +smaller and smaller Ripple so you never +hit that mode and the only way to do + + align:start position:0% +hit that mode and the only way to do + + + align:start position:0% +hit that mode and the only way to do +that is to get a bigger and bigger and + + align:start position:0% +that is to get a bigger and bigger and + + + align:start position:0% +that is to get a bigger and bigger and +bigger inductor but guess what you got + + align:start position:0% +bigger inductor but guess what you got + + + align:start position:0% +bigger inductor but guess what you got +to run it high load too and you run into + + align:start position:0% +to run it high load too and you run into + + + align:start position:0% +to run it high load too and you run into +this case where + + align:start position:0% +this case where + + + align:start position:0% +this case where +suddenly right if you've got if you've + + align:start position:0% +suddenly right if you've got if you've + + + align:start position:0% +suddenly right if you've got if you've +done that by a much bigger inductor + + align:start position:0% +done that by a much bigger inductor + + + align:start position:0% +done that by a much bigger inductor +suddenly you've gotten to the point + + align:start position:0% +suddenly you've gotten to the point + + + align:start position:0% +suddenly you've gotten to the point +where you've got a lot of inductor + + align:start position:0% +where you've got a lot of inductor + + + align:start position:0% +where you've got a lot of inductor +energy + + align:start position:0% +energy + + + align:start position:0% +energy +storage right if you're if your Ripple + + align:start position:0% +storage right if you're if your Ripple + + + align:start position:0% +storage right if you're if your Ripple +ratio is small at light load it's really + + align:start position:0% +ratio is small at light load it's really + + + align:start position:0% +ratio is small at light load it's really +tiny at high load and this Factor will + + align:start position:0% +tiny at high load and this Factor will + + + align:start position:0% +tiny at high load and this Factor will +kill you you just have way too big a + + align:start position:0% +kill you you just have way too big a + + + align:start position:0% +kill you you just have way too big a +component so as a practical matter if + + align:start position:0% +component so as a practical matter if + + + align:start position:0% +component so as a practical matter if +you're going to run run over a really + + align:start position:0% +you're going to run run over a really + + + align:start position:0% +you're going to run run over a really +wide power range you might have to deal + + align:start position:0% +wide power range you might have to deal + + + align:start position:0% +wide power range you might have to deal +with DCM okay so we often design our + + align:start position:0% +with DCM okay so we often design our + + + align:start position:0% +with DCM okay so we often design our +converters for continuous conduction + + align:start position:0% +converters for continuous conduction + + + align:start position:0% +converters for continuous conduction +mode at full power but they might go + + align:start position:0% +mode at full power but they might go + + + align:start position:0% +mode at full power but they might go +into DCM if you're at very light load + + align:start position:0% +into DCM if you're at very light load + + + align:start position:0% +into DCM if you're at very light load +power any questions about + + align:start position:0% + + + + align:start position:0% + +that + + align:start position:0% +that + + + align:start position:0% +that +okay so what can we say about you know + + align:start position:0% +okay so what can we say about you know + + + align:start position:0% +okay so what can we say about you know +operating in this new Switch State okay + + align:start position:0% +operating in this new Switch State okay + + + align:start position:0% +operating in this new Switch State okay +well let's think about that what do our + + align:start position:0% +well let's think about that what do our + + + align:start position:0% +well let's think about that what do our +waveforms look like let's recreate our + + align:start position:0% +waveforms look like let's recreate our + + + align:start position:0% +waveforms look like let's recreate our +switching + + align:start position:0% +switching + + + align:start position:0% +switching +waveforms we said we were going to have + + align:start position:0% +waveforms we said we were going to have + + + align:start position:0% +waveforms we said we were going to have +some Duty ratio right for our switch and + + align:start position:0% +some Duty ratio right for our switch and + + + align:start position:0% +some Duty ratio right for our switch and +we were always focusing on the duty + + align:start position:0% +we were always focusing on the duty + + + align:start position:0% +we were always focusing on the duty +ratio of the switch and that's useful in + + align:start position:0% +ratio of the switch and that's useful in + + + align:start position:0% +ratio of the switch and that's useful in +CCM because you know the diode does + + align:start position:0% +CCM because you know the diode does + + + align:start position:0% +CCM because you know the diode does +exactly the opposite of what the switch + + align:start position:0% +exactly the opposite of what the switch + + + align:start position:0% +exactly the opposite of what the switch +does but now if we're going to talk + + align:start position:0% +does but now if we're going to talk + + + align:start position:0% +does but now if we're going to talk +about DC M we can't talk about that so + + align:start position:0% +about DC M we can't talk about that so + + + align:start position:0% +about DC M we can't talk about that so +here's Q of + + align:start position:0% +here's Q of + + + align:start position:0% +here's Q of +T right and Q of T is doing + + align:start position:0% + + + + align:start position:0% + +something so here's T + + align:start position:0% +something so here's T + + + align:start position:0% +something so here's T +DT here's Q of t for the + + align:start position:0% +DT here's Q of t for the + + + align:start position:0% +DT here's Q of t for the +switch but I might have then think okay + + align:start position:0% +switch but I might have then think okay + + + align:start position:0% +switch but I might have then think okay +maybe what I have is some Q + + align:start position:0% + + + + align:start position:0% + +subd This is the switching period for + + align:start position:0% +subd This is the switching period for + + + align:start position:0% +subd This is the switching period for +the + + align:start position:0% + + + + align:start position:0% + +diode Q subd of T right the purple + + align:start position:0% +diode Q subd of T right the purple + + + align:start position:0% +diode Q subd of T right the purple +waveform tells me when the diode's on + + align:start position:0% +waveform tells me when the diode's on + + + align:start position:0% +waveform tells me when the diode's on +because now I have a time where the + + align:start position:0% +because now I have a time where the + + + align:start position:0% +because now I have a time where the +switch is on when the diod on and when + + align:start position:0% +switch is on when the diod on and when + + + align:start position:0% +switch is on when the diod on and when +neither are on all right and maybe this + + align:start position:0% +neither are on all right and maybe this + + + align:start position:0% +neither are on all right and maybe this +happens for some time you know this time + + align:start position:0% +happens for some time you know this time + + + align:start position:0% +happens for some time you know this time +period might might be um D + D2 * T so + + align:start position:0% +period might might be um D + D2 * T so + + + align:start position:0% +period might might be um D + D2 * T so +the diode runs with some Duty ratio + + align:start position:0% +the diode runs with some Duty ratio + + + align:start position:0% +the diode runs with some Duty ratio +D2 okay and you know to be in DCM D2 is + + align:start position:0% +D2 okay and you know to be in DCM D2 is + + + align:start position:0% +D2 okay and you know to be in DCM D2 is +less than 1us d right make sense + + align:start position:0% + + + + align:start position:0% + +everybody so okay um we have this + + align:start position:0% +everybody so okay um we have this + + + align:start position:0% +everybody so okay um we have this +additional mode what does the voltage on + + align:start position:0% +additional mode what does the voltage on + + + align:start position:0% +additional mode what does the voltage on +the inductor look like right we were + + align:start position:0% +the inductor look like right we were + + + align:start position:0% +the inductor look like right we were +focusing you know we had the voltage on + + align:start position:0% +focusing you know we had the voltage on + + + align:start position:0% +focusing you know we had the voltage on +the inductor here what does he look + + align:start position:0% + + + + align:start position:0% + +like well in the first part of the cycle + + align:start position:0% +like well in the first part of the cycle + + + align:start position:0% +like well in the first part of the cycle +he's at V1 right + + align:start position:0% +he's at V1 right + + + align:start position:0% +he's at V1 right +here's the voltage on the inductor he + + align:start position:0% +here's the voltage on the inductor he + + + align:start position:0% +here's the voltage on the inductor he +started at V1 in the first part of the + + align:start position:0% +started at V1 in the first part of the + + + align:start position:0% +started at V1 in the first part of the +cycle then when the switch turns off and + + align:start position:0% +cycle then when the switch turns off and + + + align:start position:0% +cycle then when the switch turns off and +the diode turns on he's at V1 minus + + align:start position:0% +the diode turns on he's at V1 minus + + + align:start position:0% +the diode turns on he's at V1 minus +V2 + + align:start position:0% +V2 + + + align:start position:0% +V2 +okay and then he's on for a while until + + align:start position:0% +okay and then he's on for a while until + + + align:start position:0% +okay and then he's on for a while until +this second time period D plus D2 ends + + align:start position:0% +this second time period D plus D2 ends + + + align:start position:0% +this second time period D plus D2 ends +what happens if both the switch and the + + align:start position:0% +what happens if both the switch and the + + + align:start position:0% +what happens if both the switch and the +diode are + + align:start position:0% +diode are + + + align:start position:0% +diode are +off well if both the switch and the + + align:start position:0% +off well if both the switch and the + + + align:start position:0% +off well if both the switch and the +diode are off there's no current in the + + align:start position:0% +diode are off there's no current in the + + + align:start position:0% +diode are off there's no current in the +inductor there's no didt in the inductor + + align:start position:0% +inductor there's no didt in the inductor + + + align:start position:0% +inductor there's no didt in the inductor +if there's no didt in the inductor then + + align:start position:0% +if there's no didt in the inductor then + + + align:start position:0% +if there's no didt in the inductor then +there could be no voltage across the + + align:start position:0% +there could be no voltage across the + + + align:start position:0% +there could be no voltage across the +inductor and ideally this voltage across + + align:start position:0% +inductor and ideally this voltage across + + + align:start position:0% +inductor and ideally this voltage across +the inductor would have to go to zero + + align:start position:0% +the inductor would have to go to zero + + + align:start position:0% +the inductor would have to go to zero +okay so then I'm going to get a time + + align:start position:0% +okay so then I'm going to get a time + + + align:start position:0% +okay so then I'm going to get a time +period where the inductor voltage is + + align:start position:0% +period where the inductor voltage is + + + align:start position:0% +period where the inductor voltage is +zero until the end of the cycle okay so + + align:start position:0% +zero until the end of the cycle okay so + + + align:start position:0% +zero until the end of the cycle okay so +this is the ideal + + align:start position:0% + + + + align:start position:0% + +waveforms for a discontinuous conduction + + align:start position:0% +waveforms for a discontinuous conduction + + + align:start position:0% +waveforms for a discontinuous conduction +mode where I'm plotting Vel of + + align:start position:0% +mode where I'm plotting Vel of + + + align:start position:0% +mode where I'm plotting Vel of +T okay and what do I have for periodic + + align:start position:0% +T okay and what do I have for periodic + + + align:start position:0% +T okay and what do I have for periodic +steady state requirement the average + + align:start position:0% +steady state requirement the average + + + align:start position:0% +steady state requirement the average +voltage across the inductor still has to + + align:start position:0% +voltage across the inductor still has to + + + align:start position:0% +voltage across the inductor still has to +be zero that means that this + + align:start position:0% +be zero that means that this + + + align:start position:0% +be zero that means that this +area now balances against this area Okay + + align:start position:0% +area now balances against this area Okay + + + align:start position:0% +area now balances against this area Okay +so the average the integral of this over + + align:start position:0% +so the average the integral of this over + + + align:start position:0% +so the average the integral of this over +the cycle still has to be + + align:start position:0% +the cycle still has to be + + + align:start position:0% +the cycle still has to be +zero does that make sense + + align:start position:0% + + + + align:start position:0% + +everybody and if I just plotted the + + align:start position:0% +everybody and if I just plotted the + + + align:start position:0% +everybody and if I just plotted the +current to complete everything right in + + align:start position:0% +current to complete everything right in + + + align:start position:0% +current to complete everything right in +this + + align:start position:0% + + + + align:start position:0% + +case the current starts at zero and + + align:start position:0% +case the current starts at zero and + + + align:start position:0% +case the current starts at zero and +ramps + + align:start position:0% +ramps + + + align:start position:0% +ramps +up in the second part of the cycle it + + align:start position:0% +up in the second part of the cycle it + + + align:start position:0% +up in the second part of the cycle it +ramps down and then it sits at zero for + + align:start position:0% +ramps down and then it sits at zero for + + + align:start position:0% +ramps down and then it sits at zero for +the rest of the cycle until + + align:start position:0% +the rest of the cycle until + + + align:start position:0% +the rest of the cycle until +T okay and so this is + + align:start position:0% + + + + align:start position:0% + +Isabel all right so this is what we're + + align:start position:0% +Isabel all right so this is what we're + + + align:start position:0% +Isabel all right so this is what we're +going to have in + + align:start position:0% +going to have in + + + align:start position:0% +going to have in +DCM + + align:start position:0% +DCM + + + align:start position:0% +DCM +okay um + + align:start position:0% + + + + align:start position:0% + +what is the conversion ratio in DCM and + + align:start position:0% +what is the conversion ratio in DCM and + + + align:start position:0% +what is the conversion ratio in DCM and +I say well why why do I have to ask that + + align:start position:0% +I say well why why do I have to ask that + + + align:start position:0% +I say well why why do I have to ask that +question because previously how did I + + align:start position:0% +question because previously how did I + + + align:start position:0% +question because previously how did I +find the conversion ratio right the way + + align:start position:0% +find the conversion ratio right the way + + + align:start position:0% +find the conversion ratio right the way +we got that voltage conversion ratio is + + align:start position:0% +we got that voltage conversion ratio is + + + align:start position:0% +we got that voltage conversion ratio is +what we did was we said that V1 DT is + + align:start position:0% +what we did was we said that V1 DT is + + + align:start position:0% +what we did was we said that V1 DT is +actually equal has got to be equal to V2 + + align:start position:0% +actually equal has got to be equal to V2 + + + align:start position:0% +actually equal has got to be equal to V2 +minus V1 * 1 minus DT right the average + + align:start position:0% +minus V1 * 1 minus DT right the average + + + align:start position:0% +minus V1 * 1 minus DT right the average +voltage across the inductor was Zero but + + align:start position:0% +voltage across the inductor was Zero but + + + align:start position:0% +voltage across the inductor was Zero but +that was based on this waveform our + + align:start position:0% +that was based on this waveform our + + + align:start position:0% +that was based on this waveform our +waveforms are now different so now we + + align:start position:0% +waveforms are now different so now we + + + align:start position:0% +waveforms are now different so now we +got to rec + + align:start position:0% +got to rec + + + align:start position:0% +got to rec +calculated okay but we can find the + + align:start position:0% +calculated okay but we can find the + + + align:start position:0% +calculated okay but we can find the +conversion ratio the same way we do it + + align:start position:0% +conversion ratio the same way we do it + + + align:start position:0% +conversion ratio the same way we do it +we know that the average voltage across + + align:start position:0% +we know that the average voltage across + + + align:start position:0% +we know that the average voltage across +the inductor has to be zero so let's + + align:start position:0% +the inductor has to be zero so let's + + + align:start position:0% +the inductor has to be zero so let's +just calculate that in + + align:start position:0% + + + + align:start position:0% + +PSS what do I get I get the average + + align:start position:0% +PSS what do I get I get the average + + + align:start position:0% +PSS what do I get I get the average +voltage across the inductor is equal to + + align:start position:0% +voltage across the inductor is equal to + + + align:start position:0% +voltage across the inductor is equal to +zero and that's got to be equal to D * + + align:start position:0% +zero and that's got to be equal to D * + + + align:start position:0% +zero and that's got to be equal to D * +V1 + + align:start position:0% +V1 + + + align:start position:0% +V1 +plus + + align:start position:0% +plus + + + align:start position:0% +plus +D2 * V1 - + + align:start position:0% +D2 * V1 - + + + align:start position:0% +D2 * V1 - +V2 that has to equal zero so what I get + + align:start position:0% +V2 that has to equal zero so what I get + + + align:start position:0% +V2 that has to equal zero so what I get +is if I rearrange this equation what I + + align:start position:0% +is if I rearrange this equation what I + + + align:start position:0% +is if I rearrange this equation what I +should get is D plus + + align:start position:0% +should get is D plus + + + align:start position:0% +should get is D plus +D2 * V1 is equal to D2 + + align:start position:0% + + + + align:start position:0% + +V2 or + + align:start position:0% +V2 or + + + align:start position:0% +V2 or +V2 over V1 is equal to uh D plus D2 over + + align:start position:0% +V2 over V1 is equal to uh D plus D2 over + + + align:start position:0% +V2 over V1 is equal to uh D plus D2 over +D2 + + align:start position:0% +D2 + + + align:start position:0% +D2 +V1 or D2 plus d over + + align:start position:0% +V1 or D2 plus d over + + + align:start position:0% +V1 or D2 plus d over +D2 okay which is also equal + + align:start position:0% +D2 okay which is also equal + + + align:start position:0% +D2 okay which is also equal +to + + align:start position:0% +to + + + align:start position:0% +to +um 1 + D over + + align:start position:0% +um 1 + D over + + + align:start position:0% +um 1 + D over +D2 okay so that's not exactly an + + align:start position:0% +D2 okay so that's not exactly an + + + align:start position:0% +D2 okay so that's not exactly an +answer okay in terms of it because it + + align:start position:0% +answer okay in terms of it because it + + + align:start position:0% +answer okay in terms of it because it +depends on the duty ratio of the switch + + align:start position:0% +depends on the duty ratio of the switch + + + align:start position:0% +depends on the duty ratio of the switch +but then I got to go figure out what the + + align:start position:0% +but then I got to go figure out what the + + + align:start position:0% +but then I got to go figure out what the +duty ratio of that diode's going to look + + align:start position:0% +duty ratio of that diode's going to look + + + align:start position:0% +duty ratio of that diode's going to look +like + + align:start position:0% +like + + + align:start position:0% +like +okay but what I what do I know I know + + align:start position:0% +okay but what I what do I know I know + + + align:start position:0% +okay but what I what do I know I know +that D2 is less than 1 minus D whatever + + align:start position:0% +that D2 is less than 1 minus D whatever + + + align:start position:0% +that D2 is less than 1 minus D whatever +it is is one less than one minus d right + + align:start position:0% +it is is one less than one minus d right + + + align:start position:0% +it is is one less than one minus d right +because this is the duration + + align:start position:0% +because this is the duration + + + align:start position:0% +because this is the duration +D2 or d2t right and that's less than 1 + + align:start position:0% +D2 or d2t right and that's less than 1 + + + align:start position:0% +D2 or d2t right and that's less than 1 +minus DT okay so if I took the + + align:start position:0% +minus DT okay so if I took the + + + align:start position:0% +minus DT okay so if I took the +CCM okay let's what is it this is + + align:start position:0% +CCM okay let's what is it this is + + + align:start position:0% +CCM okay let's what is it this is +DCM okay what is it in + + align:start position:0% +DCM okay what is it in + + + align:start position:0% +DCM okay what is it in +CCM okay in CCM V2 over + + align:start position:0% +CCM okay in CCM V2 over + + + align:start position:0% +CCM okay in CCM V2 over +V1 is equal to 1 over 1us D which is I + + align:start position:0% +V1 is equal to 1 over 1us D which is I + + + align:start position:0% +V1 is equal to 1 over 1us D which is I +could rewrite as 1 - D + D over 1 minus + + align:start position:0% +could rewrite as 1 - D + D over 1 minus + + + align:start position:0% +could rewrite as 1 - D + D over 1 minus +d right all I did was add a minus D and + + align:start position:0% +d right all I did was add a minus D and + + + align:start position:0% +d right all I did was add a minus D and +A plus d in the + + align:start position:0% +A plus d in the + + + align:start position:0% +A plus d in the +numerator and then I could rewrite this + + align:start position:0% +numerator and then I could rewrite this + + + align:start position:0% +numerator and then I could rewrite this +as 1 + D over 1us d + + align:start position:0% + + + + align:start position:0% + +right so here we can say that the + + align:start position:0% +right so here we can say that the + + + align:start position:0% +right so here we can say that the +conversion ratio in CCM is can be + + align:start position:0% +conversion ratio in CCM is can be + + + align:start position:0% +conversion ratio in CCM is can be +Rewritten it's less convenient form but + + align:start position:0% +Rewritten it's less convenient form but + + + align:start position:0% +Rewritten it's less convenient form but +it's 1 plus d over 1 minus + + align:start position:0% +it's 1 plus d over 1 minus + + + align:start position:0% +it's 1 plus d over 1 minus +D okay so it's clear for any value of D + + align:start position:0% +D okay so it's clear for any value of D + + + align:start position:0% +D okay so it's clear for any value of D +the conversion ratio is going to be + + align:start position:0% +the conversion ratio is going to be + + + align:start position:0% +the conversion ratio is going to be +greater than + + align:start position:0% +greater than + + + align:start position:0% +greater than +one okay here because D2 is less than 1 + + align:start position:0% +one okay here because D2 is less than 1 + + + align:start position:0% +one okay here because D2 is less than 1 +minus D V2 over V1 is bigger in + + align:start position:0% +minus D V2 over V1 is bigger in + + + align:start position:0% +minus D V2 over V1 is bigger in +discontinuous conduction mode than it + + align:start position:0% +discontinuous conduction mode than it + + + align:start position:0% +discontinuous conduction mode than it +would be in continuous conduction + + align:start position:0% +would be in continuous conduction + + + align:start position:0% +would be in continuous conduction +mode all right so what's going to + + align:start position:0% +mode all right so what's going to + + + align:start position:0% +mode all right so what's going to +happen is for a given Duty ratio + + align:start position:0% +happen is for a given Duty ratio + + + align:start position:0% +happen is for a given Duty ratio +whatever I get for my V2 it's going to + + align:start position:0% +whatever I get for my V2 it's going to + + + align:start position:0% +whatever I get for my V2 it's going to +be bigger than I would get in continuous + + align:start position:0% +be bigger than I would get in continuous + + + align:start position:0% +be bigger than I would get in continuous +conduction mode the output voltage is + + align:start position:0% +conduction mode the output voltage is + + + align:start position:0% +conduction mode the output voltage is +going to get pumped up a + + align:start position:0% +going to get pumped up a + + + align:start position:0% +going to get pumped up a +bit okay so I can tell + + align:start position:0% +bit okay so I can tell + + + align:start position:0% +bit okay so I can tell +that + + align:start position:0% +that + + + align:start position:0% +that +um that's + + align:start position:0% +um that's + + + align:start position:0% +um that's +pretty + + align:start position:0% +pretty + + + align:start position:0% +pretty +straightforward okay um it's a little + + align:start position:0% +straightforward okay um it's a little + + + align:start position:0% +straightforward okay um it's a little +little bit messy but we can go figure + + align:start position:0% +little bit messy but we can go figure + + + align:start position:0% +little bit messy but we can go figure +this out because I have the means to + + align:start position:0% +this out because I have the means to + + + align:start position:0% +this out because I have the means to +calculate what D2 is because I know + + align:start position:0% +calculate what D2 is because I know + + + align:start position:0% +calculate what D2 is because I know +exactly what these Ripple waveforms look + + align:start position:0% +exactly what these Ripple waveforms look + + + align:start position:0% +exactly what these Ripple waveforms look +like if I if I write the exact + + align:start position:0% +like if I if I write the exact + + + align:start position:0% +like if I if I write the exact +expression if I basically eliminate D2 + + align:start position:0% +expression if I basically eliminate D2 + + + align:start position:0% +expression if I basically eliminate D2 +from this expression here's what you get + + align:start position:0% +from this expression here's what you get + + + align:start position:0% +from this expression here's what you get +you get V2 over + + align:start position:0% +you get V2 over + + + align:start position:0% +you get V2 over +V1 is equal to a + + align:start position:0% +V1 is equal to a + + + align:start position:0% +V1 is equal to a +half + + align:start position:0% +half + + + align:start position:0% +half +plus uh 12 the square Ro t + + align:start position:0% + + + + align:start position:0% + +of 1 + + align:start position:0% +of 1 + + + align:start position:0% +of 1 ++ 2 d^2 RT over 2L or RT over L for DCM + + align:start position:0% + + + + align:start position:0% + +boost okay so I'm just writing what this + + align:start position:0% +boost okay so I'm just writing what this + + + align:start position:0% +boost okay so I'm just writing what this +is + + align:start position:0% +is + + + align:start position:0% +is +um for a boost converter okay it would + + align:start position:0% +um for a boost converter okay it would + + + align:start position:0% +um for a boost converter okay it would +be different for different kind of + + align:start position:0% +be different for different kind of + + + align:start position:0% +be different for different kind of +converters this is just an example but + + align:start position:0% +converters this is just an example but + + + align:start position:0% +converters this is just an example but +what's the difference well we said look + + align:start position:0% +what's the difference well we said look + + + align:start position:0% +what's the difference well we said look +if I'm in + + align:start position:0% +if I'm in + + + align:start position:0% +if I'm in +CCM + + align:start position:0% +CCM + + + align:start position:0% +CCM +right the voltage conversion RTI is just + + align:start position:0% +right the voltage conversion RTI is just + + + align:start position:0% +right the voltage conversion RTI is just +a function of Duty ratio it doesn't + + align:start position:0% +a function of Duty ratio it doesn't + + + align:start position:0% +a function of Duty ratio it doesn't +matter the inductance it doesn't matter + + align:start position:0% +matter the inductance it doesn't matter + + + align:start position:0% +matter the inductance it doesn't matter +the load resistance it's just going to + + align:start position:0% +the load resistance it's just going to + + + align:start position:0% +the load resistance it's just going to +you know very straightforward + + align:start position:0% +you know very straightforward + + + align:start position:0% +you know very straightforward +relationship suddenly when I get into + + align:start position:0% +relationship suddenly when I get into + + + align:start position:0% +relationship suddenly when I get into +DCM it depends on everything it depends + + align:start position:0% +DCM it depends on everything it depends + + + align:start position:0% +DCM it depends on everything it depends +on my load resistor it depends on my + + align:start position:0% +on my load resistor it depends on my + + + align:start position:0% +on my load resistor it depends on my +switching period it depends on my + + align:start position:0% +switching period it depends on my + + + align:start position:0% +switching period it depends on my +inductance it's a mess doesn't mean you + + align:start position:0% +inductance it's a mess doesn't mean you + + + align:start position:0% +inductance it's a mess doesn't mean you +can't do it it's just not a simple + + align:start position:0% +can't do it it's just not a simple + + + align:start position:0% +can't do it it's just not a simple +relationship + + align:start position:0% +relationship + + + align:start position:0% +relationship +anymore okay okay so suddenly it's a lot + + align:start position:0% +anymore okay okay so suddenly it's a lot + + + align:start position:0% +anymore okay okay so suddenly it's a lot +more um complicated than it was in + + align:start position:0% +more um complicated than it was in + + + align:start position:0% +more um complicated than it was in +continuous conduction mode okay and it + + align:start position:0% +continuous conduction mode okay and it + + + align:start position:0% +continuous conduction mode okay and it +also affects the converter's Dynamics as + + align:start position:0% +also affects the converter's Dynamics as + + + align:start position:0% +also affects the converter's Dynamics as +we'll + + align:start position:0% +we'll + + + align:start position:0% +we'll +see + + align:start position:0% +see + + + align:start position:0% +see +right any questions about + + align:start position:0% + + + + align:start position:0% + +that but that said we can't avoid it + + align:start position:0% +that but that said we can't avoid it + + + align:start position:0% +that but that said we can't avoid it +you how do we know that we stay periodic + + align:start position:0% +you how do we know that we stay periodic + + + align:start position:0% +you how do we know that we stay periodic +St State when we go through these + + align:start position:0% +St State when we go through these + + + align:start position:0% +St State when we go through these +different modes of + + align:start position:0% +different modes of + + + align:start position:0% +different modes of +operation that's a good question um it's + + align:start position:0% +operation that's a good question um it's + + + align:start position:0% +operation that's a good question um it's +a question of will it reach periodic + + align:start position:0% +a question of will it reach periodic + + + align:start position:0% +a question of will it reach periodic +steady + + align:start position:0% +steady + + + align:start position:0% +steady +state um that's the same analysis you go + + align:start position:0% +state um that's the same analysis you go + + + align:start position:0% +state um that's the same analysis you go +do right you can go do this analysis and + + align:start position:0% +do right you can go do this analysis and + + + align:start position:0% +do right you can go do this analysis and +find out whether it'll end up in + + align:start position:0% +find out whether it'll end up in + + + align:start position:0% +find out whether it'll end up in +periodic steady state uh It generally + + align:start position:0% +periodic steady state uh It generally + + + align:start position:0% +periodic steady state uh It generally +will settle I mean because you can solve + + align:start position:0% +will settle I mean because you can solve + + + align:start position:0% +will settle I mean because you can solve +for these things the Boost converter + + align:start position:0% +for these things the Boost converter + + + align:start position:0% +for these things the Boost converter +will end up in periodic steady state + + align:start position:0% +will end up in periodic steady state + + + align:start position:0% +will end up in periodic steady state +unless suppose I disconnected this load + + align:start position:0% +unless suppose I disconnected this load + + + align:start position:0% +unless suppose I disconnected this load +resistor in this case that's equival to + + align:start position:0% +resistor in this case that's equival to + + + align:start position:0% +resistor in this case that's equival to +making r equal to Infinity + + align:start position:0% +making r equal to Infinity + + + align:start position:0% +making r equal to Infinity +right if I come over + + align:start position:0% +right if I come over + + + align:start position:0% +right if I come over +here + + align:start position:0% +here + + + align:start position:0% +here +um and I make r equal to Infinity V2 + + align:start position:0% +um and I make r equal to Infinity V2 + + + align:start position:0% +um and I make r equal to Infinity V2 +over V1 goes to Infinity right that + + align:start position:0% +over V1 goes to Infinity right that + + + align:start position:0% +over V1 goes to Infinity right that +means + + align:start position:0% +means + + + align:start position:0% +means +the it's just going to wander off to + + align:start position:0% +the it's just going to wander off to + + + align:start position:0% +the it's just going to wander off to +Infinity the output will wander off to + + align:start position:0% +Infinity the output will wander off to + + + align:start position:0% +Infinity the output will wander off to +Infinity why would that happen because + + align:start position:0% +Infinity why would that happen because + + + align:start position:0% +Infinity why would that happen because +look this is iil in DCM right so every + + align:start position:0% +look this is iil in DCM right so every + + + align:start position:0% +look this is iil in DCM right so every +cycle I take energy out of the input put + + align:start position:0% +cycle I take energy out of the input put + + + align:start position:0% +cycle I take energy out of the input put +it in the inductor turn off the switch + + align:start position:0% +it in the inductor turn off the switch + + + align:start position:0% +it in the inductor turn off the switch +and that energy goes to the output and I + + align:start position:0% +and that energy goes to the output and I + + + align:start position:0% +and that energy goes to the output and I +build up some energy on the + + align:start position:0% +build up some energy on the + + + align:start position:0% +build up some energy on the +capacitor and the feedback mechanism + + align:start position:0% +capacitor and the feedback mechanism + + + align:start position:0% +capacitor and the feedback mechanism +that gets you to steady state is the + + align:start position:0% +that gets you to steady state is the + + + align:start position:0% +that gets you to steady state is the +resistor drains some of that energy but + + align:start position:0% +resistor drains some of that energy but + + + align:start position:0% +resistor drains some of that energy but +if you don't ever drain the energy this + + align:start position:0% +if you don't ever drain the energy this + + + align:start position:0% +if you don't ever drain the energy this +just wanders off to Infinity I actually + + align:start position:0% +just wanders off to Infinity I actually + + + align:start position:0% +just wanders off to Infinity I actually +had a converter explode on me once + + align:start position:0% +had a converter explode on me once + + + align:start position:0% +had a converter explode on me once +because of that the the electrolytic + + align:start position:0% +because of that the the electrolytic + + + align:start position:0% +because of that the the electrolytic +capacitor literally blew up in my face + + align:start position:0% +capacitor literally blew up in my face + + + align:start position:0% +capacitor literally blew up in my face +um I what's + + align:start position:0% +um I what's + + + align:start position:0% +um I what's +that you're damn right I I can still + + align:start position:0% +that you're damn right I I can still + + + align:start position:0% +that you're damn right I I can still +see I always wear glasses when working + + align:start position:0% +see I always wear glasses when working + + + align:start position:0% +see I always wear glasses when working +on a higher power thing these days and I + + align:start position:0% +on a higher power thing these days and I + + + align:start position:0% +on a higher power thing these days and I +should on any converter because I + + align:start position:0% +should on any converter because I + + + align:start position:0% +should on any converter because I +literally I was looking down to it and I + + align:start position:0% +literally I was looking down to it and I + + + align:start position:0% +literally I was looking down to it and I +bumped the connection to the load with + + align:start position:0% +bumped the connection to the load with + + + align:start position:0% +bumped the connection to the load with +my elbow and the capacitor just + + align:start position:0% +my elbow and the capacitor just + + + align:start position:0% +my elbow and the capacitor just +literally exploded in my face um they + + align:start position:0% +literally exploded in my face um they + + + align:start position:0% +literally exploded in my face um they +often don't vent so dramatically they're + + align:start position:0% +often don't vent so dramatically they're + + + align:start position:0% +often don't vent so dramatically they're +not supposed to but in this case it + + align:start position:0% +not supposed to but in this case it + + + align:start position:0% +not supposed to but in this case it +exploded um so yes wearing glasses is a + + align:start position:0% +exploded um so yes wearing glasses is a + + + align:start position:0% +exploded um so yes wearing glasses is a +good idea in these kind of things I + + align:start position:0% +good idea in these kind of things I + + + align:start position:0% +good idea in these kind of things I +actually did that this morning on our + + align:start position:0% +actually did that this morning on our + + + align:start position:0% +actually did that this morning on our +demo converter too but that's not what + + align:start position:0% +demo converter too but that's not what + + + align:start position:0% +demo converter too but that's not what +happened uh but what happened was um the + + align:start position:0% +happened uh but what happened was um the + + + align:start position:0% +happened uh but what happened was um the +mosfet started breaking down in other + + align:start position:0% +mosfet started breaking down in other + + + align:start position:0% +mosfet started breaking down in other +words it would just start dumping energy + + align:start position:0% +words it would just start dumping energy + + + align:start position:0% +words it would just start dumping energy +into the mosfet which isn't good for the + + align:start position:0% +into the mosfet which isn't good for the + + + align:start position:0% +into the mosfet which isn't good for the +mosfet so fortunately I didn't kill the + + align:start position:0% +mosfet so fortunately I didn't kill the + + + align:start position:0% +mosfet so fortunately I didn't kill the +demo because I was being stupid by + + align:start position:0% +demo because I was being stupid by + + + align:start position:0% +demo because I was being stupid by +taking off the load okay but the point + + align:start position:0% +taking off the load okay but the point + + + align:start position:0% +taking off the load okay but the point +is you you don't necessarily have to get + + align:start position:0% +is you you don't necessarily have to get + + + align:start position:0% +is you you don't necessarily have to get +to periodic steady state in all + + align:start position:0% +to periodic steady state in all + + + align:start position:0% +to periodic steady state in all +converters and this is an example where + + align:start position:0% +converters and this is an example where + + + align:start position:0% +converters and this is an example where +you can get to really high voltages in + + align:start position:0% +you can get to really high voltages in + + + align:start position:0% +you can get to really high voltages in +fact if you look at like little photo + + align:start position:0% +fact if you look at like little photo + + + align:start position:0% +fact if you look at like little photo +flash chargers for for um you know those + + align:start position:0% +flash chargers for for um you know those + + + align:start position:0% +flash chargers for for um you know those +little cameras that you use you know at + + align:start position:0% +little cameras that you use you know at + + + align:start position:0% +little cameras that you use you know at +weddings that actual film cameras + + align:start position:0% +weddings that actual film cameras + + + align:start position:0% +weddings that actual film cameras +yielding cameras right they they often + + align:start position:0% +yielding cameras right they they often + + + align:start position:0% +yielding cameras right they they often +use a boost or a flyback in DCM to + + align:start position:0% +use a boost or a flyback in DCM to + + + align:start position:0% +use a boost or a flyback in DCM to +charge the output voltage up from like a + + align:start position:0% +charge the output voltage up from like a + + + align:start position:0% +charge the output voltage up from like a +volt and a half up to a few hundred + + align:start position:0% +volt and a half up to a few hundred + + + align:start position:0% +volt and a half up to a few hundred +volts same trick you can get to very + + align:start position:0% +volts same trick you can get to very + + + align:start position:0% +volts same trick you can get to very +large conversion ratios this way all + + align:start position:0% +large conversion ratios this way all + + + align:start position:0% +large conversion ratios this way all +right so your know DCM is harder to + + align:start position:0% +right so your know DCM is harder to + + + align:start position:0% +right so your know DCM is harder to +model how would I think about modeling + + align:start position:0% +model how would I think about modeling + + + align:start position:0% +model how would I think about modeling +it um and I'll let Mony start to set up + + align:start position:0% +it um and I'll let Mony start to set up + + + align:start position:0% +it um and I'll let Mony start to set up +and roll down screens and stuff + + align:start position:0% +and roll down screens and stuff + + + align:start position:0% +and roll down screens and stuff +um one way I could think about this is + + align:start position:0% +um one way I could think about this is + + + align:start position:0% +um one way I could think about this is +the + + align:start position:0% +the + + + align:start position:0% +the +following okay maybe I would think about + + align:start position:0% +following okay maybe I would think about + + + align:start position:0% +following okay maybe I would think about +if I if I looked at my converter + + align:start position:0% +if I if I looked at my converter + + + align:start position:0% +if I if I looked at my converter +here this is my inductor current + + align:start position:0% + + + + align:start position:0% + +waveform what does my diode current + + align:start position:0% +waveform what does my diode current + + + align:start position:0% +waveform what does my diode current +waveform look like I + + align:start position:0% + + + + align:start position:0% + +subd okay I subd is zero in the first + + align:start position:0% +subd okay I subd is zero in the first + + + align:start position:0% +subd okay I subd is zero in the first +part of the s + + align:start position:0% +part of the s + + + align:start position:0% +part of the s +cycle then it conducts in this second + + align:start position:0% +cycle then it conducts in this second + + + align:start position:0% +cycle then it conducts in this second +part of the cycle until D plus + + align:start position:0% +part of the cycle until D plus + + + align:start position:0% +part of the cycle until D plus +D2 and then it's zero for the rest of + + align:start position:0% +D2 and then it's zero for the rest of + + + align:start position:0% +D2 and then it's zero for the rest of +the cycle right so this is DT this is D+ + + align:start position:0% +the cycle right so this is DT this is D+ + + + align:start position:0% +the cycle right so this is DT this is D+ +D2 T and so forth right so + + align:start position:0% +D2 T and so forth right so + + + align:start position:0% +D2 T and so forth right so +maybe I could think about modeling my + + align:start position:0% +maybe I could think about modeling my + + + align:start position:0% +maybe I could think about modeling my +converter from a control perspective as + + align:start position:0% +converter from a control perspective as + + + align:start position:0% +converter from a control perspective as +just whatever this current ID is into + + align:start position:0% +just whatever this current ID is into + + + align:start position:0% +just whatever this current ID is into +the output right so maybe I would model + + align:start position:0% +the output right so maybe I would model + + + align:start position:0% +the output right so maybe I would model +it by saying okay let me think of my + + align:start position:0% +it by saying okay let me think of my + + + align:start position:0% +it by saying okay let me think of my +converter is this current + + align:start position:0% + + + + align:start position:0% + +ID which looks like + + align:start position:0% + + + + align:start position:0% + +this DT D+ D2 T and T and just repeats + + align:start position:0% +this DT D+ D2 T and T and just repeats + + + align:start position:0% +this DT D+ D2 T and T and just repeats +right into my output + + align:start position:0% +right into my output + + + align:start position:0% +right into my output +capacitor + + align:start position:0% +capacitor + + + align:start position:0% +capacitor +okay and + + align:start position:0% +okay and + + + align:start position:0% +okay and +resistor so maybe I would s start to + + align:start position:0% +resistor so maybe I would s start to + + + align:start position:0% +resistor so maybe I would s start to +think of my converter as some s sort of + + align:start position:0% +think of my converter as some s sort of + + + align:start position:0% +think of my converter as some s sort of +funny current source and maybe I can + + align:start position:0% +funny current source and maybe I can + + + align:start position:0% +funny current source and maybe I can +relate this current Source back to the + + align:start position:0% +relate this current Source back to the + + + align:start position:0% +relate this current Source back to the +component values and just start thinking + + align:start position:0% +component values and just start thinking + + + align:start position:0% +component values and just start thinking +about my converter as a current Source + + align:start position:0% +about my converter as a current Source + + + align:start position:0% +about my converter as a current Source +because that's really what I've turned + + align:start position:0% +because that's really what I've turned + + + align:start position:0% +because that's really what I've turned +it into right I'm going to be squirting + + align:start position:0% +it into right I'm going to be squirting + + + align:start position:0% +it into right I'm going to be squirting +some current into that output capacitor + + align:start position:0% +some current into that output capacitor + + + align:start position:0% +some current into that output capacitor +every cycle all right well what does + + align:start position:0% +every cycle all right well what does + + + align:start position:0% +every cycle all right well what does +that look like um what I know here is + + align:start position:0% +that look like um what I know here is + + + align:start position:0% +that look like um what I know here is +that this + + align:start position:0% +that this + + + align:start position:0% +that this +current I + + align:start position:0% +current I + + + align:start position:0% +current I +Peak I Peak + + align:start position:0% +Peak I Peak + + + align:start position:0% +Peak I Peak +is equal to V1 DT + + align:start position:0% +is equal to V1 DT + + + align:start position:0% +is equal to V1 DT +L + + align:start position:0% +L + + + align:start position:0% +L +right and this time + + align:start position:0% + + + + align:start position:0% + +period let me call this time period to + + align:start position:0% +period let me call this time period to + + + align:start position:0% +period let me call this time period to +discharge delta T right which is just + + align:start position:0% +discharge delta T right which is just + + + align:start position:0% +discharge delta T right which is just +d2t right uh what do I know I know that + + align:start position:0% +d2t right uh what do I know I know that + + + align:start position:0% +d2t right uh what do I know I know that +V is equal to LD + + align:start position:0% +V is equal to LD + + + align:start position:0% +V is equal to LD +DT right so delta T is equal to + + align:start position:0% +DT right so delta T is equal to + + + align:start position:0% +DT right so delta T is equal to +d2t is equal to + + align:start position:0% +d2t is equal to + + + align:start position:0% +d2t is equal to +l i + + align:start position:0% +l i + + + align:start position:0% +l i +Peak divided + + align:start position:0% +Peak divided + + + align:start position:0% +Peak divided +by + + align:start position:0% +by + + + align:start position:0% +by +um Li Peak divided V which is V2 minus + + align:start position:0% + + + + align:start position:0% + +V1 + + align:start position:0% +V1 + + + align:start position:0% +V1 +right and I can put in I Peak here so + + align:start position:0% +right and I can put in I Peak here so + + + align:start position:0% +right and I can put in I Peak here so +that's just going to be uh V1 + + align:start position:0% + + + + align:start position:0% + +DT V1 DT over L / V2 minus + + align:start position:0% +DT V1 DT over L / V2 minus + + + align:start position:0% +DT V1 DT over L / V2 minus +V1 okay that make sense to + + align:start position:0% +V1 okay that make sense to + + + align:start position:0% +V1 okay that make sense to +everybody and so let me ask what is the + + align:start position:0% +everybody and so let me ask what is the + + + align:start position:0% +everybody and so let me ask what is the +average what's important over the + + align:start position:0% +average what's important over the + + + align:start position:0% +average what's important over the +switching cycle is what's the average + + align:start position:0% +switching cycle is what's the average + + + align:start position:0% +switching cycle is what's the average +current that I'm sticking into the + + align:start position:0% +current that I'm sticking into the + + + align:start position:0% +current that I'm sticking into the +output right I should ask sort of each + + align:start position:0% +output right I should ask sort of each + + + align:start position:0% +output right I should ask sort of each +cycle how much on average am I squirting + + align:start position:0% +cycle how much on average am I squirting + + + align:start position:0% +cycle how much on average am I squirting +into the output well I subd the average + + align:start position:0% +into the output well I subd the average + + + align:start position:0% +into the output well I subd the average +value of I subd is basically the area + + align:start position:0% +value of I subd is basically the area + + + align:start position:0% +value of I subd is basically the area +there which would be 12 the base of that + + align:start position:0% +there which would be 12 the base of that + + + align:start position:0% +there which would be 12 the base of that +which is this delta + + align:start position:0% +which is this delta + + + align:start position:0% +which is this delta +T V1 + + align:start position:0% +T V1 + + + align:start position:0% +T V1 +DT over V2 minus + + align:start position:0% + + + + align:start position:0% + +V1 okay half the base times the height + + align:start position:0% +V1 okay half the base times the height + + + align:start position:0% +V1 okay half the base times the height +which is I Peak which is V1 + + align:start position:0% +which is I Peak which is V1 + + + align:start position:0% +which is I Peak which is V1 +DT over L okay this is the area under + + align:start position:0% +DT over L okay this is the area under + + + align:start position:0% +DT over L okay this is the area under +that triangle 12 base * height * 1/ + + align:start position:0% +that triangle 12 base * height * 1/ + + + align:start position:0% +that triangle 12 base * height * 1/ +T okay if I rewrite that then what I'm + + align:start position:0% +T okay if I rewrite that then what I'm + + + align:start position:0% +T okay if I rewrite that then what I'm +going to get is 12 + + align:start position:0% +going to get is 12 + + + align:start position:0% +going to get is 12 +V1 + + align:start position:0% +V1 + + + align:start position:0% +V1 +T + + align:start position:0% +T + + + align:start position:0% +T +V1 + + align:start position:0% +V1 + + + align:start position:0% +V1 +squared + + align:start position:0% +squared + + + align:start position:0% +squared +T over 2 V2 - V1 L * D + + align:start position:0% + + + + align:start position:0% + +^2 okay + + align:start position:0% +^2 okay + + + align:start position:0% +^2 okay +I just see double check to make sure I + + align:start position:0% +I just see double check to make sure I + + + align:start position:0% +I just see double check to make sure I +did my math right here something like + + align:start position:0% +did my math right here something like + + + align:start position:0% +did my math right here something like +this anyways v1^2 T over 2L V2 minus V1 + + align:start position:0% +this anyways v1^2 T over 2L V2 minus V1 + + + align:start position:0% +this anyways v1^2 T over 2L V2 minus V1 +d^2 okay yeah so really what I have is + + align:start position:0% +d^2 okay yeah so really what I have is + + + align:start position:0% +d^2 okay yeah so really what I have is +now I can think of the all the converter + + align:start position:0% +now I can think of the all the converter + + + align:start position:0% +now I can think of the all the converter +leading up to the output cap as just a + + align:start position:0% +leading up to the output cap as just a + + + align:start position:0% +leading up to the output cap as just a +current Source that's a function of the + + align:start position:0% +current Source that's a function of the + + + align:start position:0% +current Source that's a function of the +duty ratio I + + align:start position:0% +duty ratio I + + + align:start position:0% +duty ratio I +control right so I've sort of turned + + align:start position:0% +control right so I've sort of turned + + + align:start position:0% +control right so I've sort of turned +this thing into a current source that + + align:start position:0% +this thing into a current source that + + + align:start position:0% +this thing into a current source that +squirts current into the output and I + + align:start position:0% +squirts current into the output and I + + + align:start position:0% +squirts current into the output and I +think about it that way and control it + + align:start position:0% +think about it that way and control it + + + align:start position:0% +think about it that way and control it +that way and if I know what my load + + align:start position:0% +that way and if I know what my load + + + align:start position:0% +that way and if I know what my load +resistor is and the voltage I want I + + align:start position:0% +resistor is and the voltage I want I + + + align:start position:0% +resistor is and the voltage I want I +know how much average current I want to + + align:start position:0% +know how much average current I want to + + + align:start position:0% +know how much average current I want to +stick into it okay so that's how I might + + align:start position:0% +stick into it okay so that's how I might + + + align:start position:0% +stick into it okay so that's how I might +Model A DCM + + align:start position:0% +Model A DCM + + + align:start position:0% +Model A DCM +converter it's more complicated in some + + align:start position:0% +converter it's more complicated in some + + + align:start position:0% +converter it's more complicated in some +sense than my continuous conduction mode + + align:start position:0% +sense than my continuous conduction mode + + + align:start position:0% +sense than my continuous conduction mode +converter because it's a function of all + + align:start position:0% +converter because it's a function of all + + + align:start position:0% +converter because it's a function of all +this junk it m you know my switching + + align:start position:0% +this junk it m you know my switching + + + align:start position:0% +this junk it m you know my switching +period And my and my inductor value and + + align:start position:0% +period And my and my inductor value and + + + align:start position:0% +period And my and my inductor value and +all that stuff matters where it didn't + + align:start position:0% +all that stuff matters where it didn't + + + align:start position:0% +all that stuff matters where it didn't +before but you know I have to live with + + align:start position:0% +before but you know I have to live with + + + align:start position:0% +before but you know I have to live with +that because it's this more complicated + + align:start position:0% +that because it's this more complicated + + + align:start position:0% +that because it's this more complicated +operating + + align:start position:0% +operating + + + align:start position:0% +operating +mode okay yeah so does that mean when + + align:start position:0% +mode okay yeah so does that mean when + + + align:start position:0% +mode okay yeah so does that mean when +you go from CCM DCM you're probably + + align:start position:0% +you go from CCM DCM you're probably + + + align:start position:0% +you go from CCM DCM you're probably +going to change a duty cycle to maintain + + align:start position:0% +going to change a duty cycle to maintain + + + align:start position:0% +going to change a duty cycle to maintain +a Target voltage that's right you're + + align:start position:0% +a Target voltage that's right you're + + + align:start position:0% +a Target voltage that's right you're +going to use a lower duty cycle than you + + align:start position:0% +going to use a lower duty cycle than you + + + align:start position:0% +going to use a lower duty cycle than you +would otherwise use in the Boost + + align:start position:0% +would otherwise use in the Boost + + + align:start position:0% +would otherwise use in the Boost +converter + + align:start position:0% +converter + + + align:start position:0% +converter +yes that's right because the conversion + + align:start position:0% +yes that's right because the conversion + + + align:start position:0% +yes that's right because the conversion +ratio goes up and so your controller and + + align:start position:0% +ratio goes up and so your controller and + + + align:start position:0% +ratio goes up and so your controller and +we'll talk about this later your + + align:start position:0% +we'll talk about this later your + + + align:start position:0% +we'll talk about this later your +controller usually has to manage that + + align:start position:0% +controller usually has to manage that + + + align:start position:0% +controller usually has to manage that +boundary you know you have to have a + + align:start position:0% +boundary you know you have to have a + + + align:start position:0% +boundary you know you have to have a +controller that works for either case + + align:start position:0% +controller that works for either case + + + align:start position:0% +controller that works for either case +okay let's just take a look at this so + + align:start position:0% +okay let's just take a look at this so + + + align:start position:0% +okay let's just take a look at this so +mon set up a an actual boost converter + + align:start position:0% +mon set up a an actual boost converter + + + align:start position:0% +mon set up a an actual boost converter +that's doing this and let's take take a + + align:start position:0% +that's doing this and let's take take a + + + align:start position:0% +that's doing this and let's take take a +look at the + + align:start position:0% +look at the + + + align:start position:0% +look at the +waveforms in + + align:start position:0% +waveforms in + + + align:start position:0% +waveforms in +yellow you can see the + + align:start position:0% +yellow you can see the + + + align:start position:0% +yellow you can see the +uh you can essentially see the switch + + align:start position:0% +uh you can essentially see the switch + + + align:start position:0% +uh you can essentially see the switch +voltage waveform which is essentially + + align:start position:0% +voltage waveform which is essentially + + + align:start position:0% +voltage waveform which is essentially +this waveform moved up where this is + + align:start position:0% +this waveform moved up where this is + + + align:start position:0% +this waveform moved up where this is +zero right so in the first part of the + + align:start position:0% +zero right so in the first part of the + + + align:start position:0% +zero right so in the first part of the +cycle you get + + align:start position:0% +cycle you get + + + align:start position:0% +cycle you get +zero okay in the yellow away from the + + align:start position:0% +zero okay in the yellow away from the + + + align:start position:0% +zero okay in the yellow away from the +second part of the cycle it's at V2 and + + align:start position:0% +second part of the cycle it's at V2 and + + + align:start position:0% +second part of the cycle it's at V2 and +then you get this time period where you + + align:start position:0% +then you get this time period where you + + + align:start position:0% +then you get this time period where you +see this voltage range + + align:start position:0% +see this voltage range + + + align:start position:0% +see this voltage range +okay what the heck is that well I said + + align:start position:0% +okay what the heck is that well I said + + + align:start position:0% +okay what the heck is that well I said +we had this time period where both the + + align:start position:0% +we had this time period where both the + + + align:start position:0% +we had this time period where both the +switch and the diode were open and so + + align:start position:0% +switch and the diode were open and so + + + align:start position:0% +switch and the diode were open and so +that this voltage here ought to be + + align:start position:0% +that this voltage here ought to be + + + align:start position:0% +that this voltage here ought to be +exactly at B1 right but what really + + align:start position:0% +exactly at B1 right but what really + + + align:start position:0% +exactly at B1 right but what really +happens in the real world is that guess + + align:start position:0% +happens in the real world is that guess + + + align:start position:0% +happens in the real world is that guess +what there's some switch + + align:start position:0% +what there's some switch + + + align:start position:0% +what there's some switch +capacitance and some diode capacitance + + align:start position:0% +capacitance and some diode capacitance + + + align:start position:0% +capacitance and some diode capacitance +and so what happens is this voltage + + align:start position:0% +and so what happens is this voltage + + + align:start position:0% +and so what happens is this voltage +instead of going to zero + + align:start position:0% + + + + align:start position:0% + +rings with those capacitance the + + align:start position:0% +rings with those capacitance the + + + align:start position:0% +rings with those capacitance the +inductor ringing with the parasitic + + align:start position:0% +inductor ringing with the parasitic + + + align:start position:0% +inductor ringing with the parasitic +capacitances people don't like that + + align:start position:0% +capacitances people don't like that + + + align:start position:0% +capacitances people don't like that +that's unpleasant right it causes noise + + align:start position:0% +that's unpleasant right it causes noise + + + align:start position:0% +that's unpleasant right it causes noise +and stuff but you can't do anything + + align:start position:0% +and stuff but you can't do anything + + + align:start position:0% +and stuff but you can't do anything +about it if you're going to have both + + align:start position:0% +about it if you're going to have both + + + align:start position:0% +about it if you're going to have both +devices off in some cases actually + + align:start position:0% +devices off in some cases actually + + + align:start position:0% +devices off in some cases actually +people actually even put in another + + align:start position:0% +people actually even put in another + + + align:start position:0% +people actually even put in another +switch to short it out but generally you + + align:start position:0% +switch to short it out but generally you + + + align:start position:0% +switch to short it out but generally you +don't generally just let it ring and + + align:start position:0% +don't generally just let it ring and + + + align:start position:0% +don't generally just let it ring and +that's life + + align:start position:0% +that's life + + + align:start position:0% +that's life +okay um but you can now see that you + + align:start position:0% +okay um but you can now see that you + + + align:start position:0% +okay um but you can now see that you +have the rising inductor current the + + align:start position:0% +have the rising inductor current the + + + align:start position:0% +have the rising inductor current the +falling inductor current is zero it's + + align:start position:0% +falling inductor current is zero it's + + + align:start position:0% +falling inductor current is zero it's +exactly doing what this yellow waveform + + align:start position:0% +exactly doing what this yellow waveform + + + align:start position:0% +exactly doing what this yellow waveform +is doing here okay any questions about + + align:start position:0% + + + + align:start position:0% + +that yeah can you mention the source + + align:start position:0% +that yeah can you mention the source + + + align:start position:0% +that yeah can you mention the source +that cost that range again the it's + + align:start position:0% +that cost that range again the it's + + + align:start position:0% +that cost that range again the it's +basically the + + align:start position:0% + + + + align:start position:0% + +inductor resonating with parasitic + + align:start position:0% +inductor resonating with parasitic + + + align:start position:0% +inductor resonating with parasitic +capacitance at this + + align:start position:0% +capacitance at this + + + align:start position:0% +capacitance at this +node yeah it's it's an unfortunate thing + + align:start position:0% +node yeah it's it's an unfortunate thing + + + align:start position:0% +node yeah it's it's an unfortunate thing +people don't like it it causes noise a + + align:start position:0% +people don't like it it causes noise a + + + align:start position:0% +people don't like it it causes noise a +little bit annoying that's life okay + + align:start position:0% +little bit annoying that's life okay + + + align:start position:0% +little bit annoying that's life okay +um so I said sometimes you have to live + + align:start position:0% +um so I said sometimes you have to live + + + align:start position:0% +um so I said sometimes you have to live +with TCM operation especially if you + + align:start position:0% +with TCM operation especially if you + + + align:start position:0% +with TCM operation especially if you +operate over really wide load ranges + + align:start position:0% +operate over really wide load ranges + + + align:start position:0% +operate over really wide load ranges +right or you want a finite value for + + align:start position:0% +right or you want a finite value for + + + align:start position:0% +right or you want a finite value for +your inductor sizes + + align:start position:0% +your inductor sizes + + + align:start position:0% +your inductor sizes +okay sometimes you actually want DCM + + align:start position:0% +okay sometimes you actually want DCM + + + align:start position:0% +okay sometimes you actually want DCM +operation people often design their + + align:start position:0% +operation people often design their + + + align:start position:0% +operation people often design their +converters for DCM operation why is that + + align:start position:0% +converters for DCM operation why is that + + + align:start position:0% +converters for DCM operation why is that +well + + align:start position:0% + + + + align:start position:0% + +suppose I thought of I had a reference + + align:start position:0% +suppose I thought of I had a reference + + + align:start position:0% +suppose I thought of I had a reference +current and in this case since I'm + + align:start position:0% +current and in this case since I'm + + + align:start position:0% +current and in this case since I'm +talking about a boost converter let me + + align:start position:0% +talking about a boost converter let me + + + align:start position:0% +talking about a boost converter let me +think of suppose I had a reference + + align:start position:0% +think of suppose I had a reference + + + align:start position:0% +think of suppose I had a reference +current for current to draw to deliver + + align:start position:0% +current for current to draw to deliver + + + align:start position:0% +current for current to draw to deliver +the power I wanted from the output from + + align:start position:0% +the power I wanted from the output from + + + align:start position:0% +the power I wanted from the output from +the + + align:start position:0% +the + + + align:start position:0% +the +input okay if I have a small Ripple + + align:start position:0% +input okay if I have a small Ripple + + + align:start position:0% +input okay if I have a small Ripple +converter and I say okay you know + + align:start position:0% +converter and I say okay you know + + + align:start position:0% +converter and I say okay you know +ideally speaking to support the load I + + align:start position:0% +ideally speaking to support the load I + + + align:start position:0% +ideally speaking to support the load I +had this low current reference and then + + align:start position:0% +had this low current reference and then + + + align:start position:0% +had this low current reference and then +I stepped it up for this higher current + + align:start position:0% +I stepped it up for this higher current + + + align:start position:0% +I stepped it up for this higher current +reference this is sort of I ref for the + + align:start position:0% +reference this is sort of I ref for the + + + align:start position:0% +reference this is sort of I ref for the +reference current for the inductor + + align:start position:0% +reference current for the inductor + + + align:start position:0% +reference current for the inductor +waveform right if I have a small Ripple + + align:start position:0% +waveform right if I have a small Ripple + + + align:start position:0% +waveform right if I have a small Ripple +converter right and it's Rippling like + + align:start position:0% +converter right and it's Rippling like + + + align:start position:0% +converter right and it's Rippling like +this and then I step the reference I + + align:start position:0% +this and then I step the reference I + + + align:start position:0% +this and then I step the reference I +want much more current to deliver more + + align:start position:0% +want much more current to deliver more + + + align:start position:0% +want much more current to deliver more +power what has to happen well the + + align:start position:0% +power what has to happen well the + + + align:start position:0% +power what has to happen well the +inductor current is going to slew + + align:start position:0% +inductor current is going to slew + + + align:start position:0% +inductor current is going to slew +up and eventually it can get there and I + + align:start position:0% +up and eventually it can get there and I + + + align:start position:0% +up and eventually it can get there and I +can deliver this again right but you + + align:start position:0% +can deliver this again right but you + + + align:start position:0% +can deliver this again right but you +notice that there's this time period + + align:start position:0% +notice that there's this time period + + + align:start position:0% +notice that there's this time period +where the inductor current takes a lot + + align:start position:0% +where the inductor current takes a lot + + + align:start position:0% +where the inductor current takes a lot +of time to change if the Ripple is small + + align:start position:0% +of time to change if the Ripple is small + + + align:start position:0% +of time to change if the Ripple is small +the inductor value is Big it takes a lot + + align:start position:0% +the inductor value is Big it takes a lot + + + align:start position:0% +the inductor value is Big it takes a lot +of time to put the voltage across the + + align:start position:0% +of time to put the voltage across the + + + align:start position:0% +of time to put the voltage across the +inductor to slew the current in it right + + align:start position:0% +inductor to slew the current in it right + + + align:start position:0% +inductor to slew the current in it right +and that means for all this time period + + align:start position:0% +and that means for all this time period + + + align:start position:0% +and that means for all this time period +you're not delivering the right output + + align:start position:0% +you're not delivering the right output + + + align:start position:0% +you're not delivering the right output +power or you're at least not drawing the + + align:start position:0% +power or you're at least not drawing the + + + align:start position:0% +power or you're at least not drawing the +right input power right so this + + align:start position:0% +right input power right so this + + + align:start position:0% +right input power right so this +converter its ability to change its + + align:start position:0% +converter its ability to change its + + + align:start position:0% +converter its ability to change its +operating point is limited by the small + + align:start position:0% +operating point is limited by the small + + + align:start position:0% +operating point is limited by the small +Ripple suppose I had a DCM + + align:start position:0% +Ripple suppose I had a DCM + + + align:start position:0% +Ripple suppose I had a DCM +converter well you know maybe I have + + align:start position:0% +converter well you know maybe I have + + + align:start position:0% +converter well you know maybe I have +something like this and I again I step + + align:start position:0% +something like this and I again I step + + + align:start position:0% +something like this and I again I step +my ripple but maybe in a DCM converter + + align:start position:0% +my ripple but maybe in a DCM converter + + + align:start position:0% +my ripple but maybe in a DCM converter +my inductor current looks like + + align:start position:0% + + + + align:start position:0% + +this and the next cycle I want more fine + + align:start position:0% + + + + align:start position:0% + +boom right I can deliver that almost + + align:start position:0% +boom right I can deliver that almost + + + align:start position:0% +boom right I can deliver that almost +instantly in other words the high Ripple + + align:start position:0% +instantly in other words the high Ripple + + + align:start position:0% +instantly in other words the high Ripple +means that I can change the average + + align:start position:0% +means that I can change the average + + + align:start position:0% +means that I can change the average +current in the inductor much faster + + align:start position:0% +current in the inductor much faster + + + align:start position:0% +current in the inductor much faster +maybe even within a cycle okay so + + align:start position:0% +maybe even within a cycle okay so + + + align:start position:0% +maybe even within a cycle okay so +there's on the one hand we often want + + align:start position:0% +there's on the one hand we often want + + + align:start position:0% +there's on the one hand we often want +small Ripple because we want nice + + align:start position:0% +small Ripple because we want nice + + + align:start position:0% +small Ripple because we want nice +waveform and not a lot of Ripple and we + + align:start position:0% +waveform and not a lot of Ripple and we + + + align:start position:0% +waveform and not a lot of Ripple and we +got to filter it on the other hand the + + align:start position:0% +got to filter it on the other hand the + + + align:start position:0% +got to filter it on the other hand the +ability to change the energy storage and + + align:start position:0% +ability to change the energy storage and + + + align:start position:0% +ability to change the energy storage and +the energy processing of the converter + + align:start position:0% +the energy processing of the converter + + + align:start position:0% +the energy processing of the converter +quickly might take you towards using DCM + + align:start position:0% +quickly might take you towards using DCM + + + align:start position:0% +quickly might take you towards using DCM +so for a very high transient response + + align:start position:0% +so for a very high transient response + + + align:start position:0% +so for a very high transient response +converter having high Ripple and + + align:start position:0% +converter having high Ripple and + + + align:start position:0% +converter having high Ripple and +possibly DCM operation can be a good + + align:start position:0% +possibly DCM operation can be a good + + + align:start position:0% +possibly DCM operation can be a good +thing + + align:start position:0% +thing + + + align:start position:0% +thing +okay any last questions before we wrap + + align:start position:0% + + + + align:start position:0% + +up okay uh next class we're going to + + align:start position:0% +up okay uh next class we're going to + + + align:start position:0% +up okay uh next class we're going to +start talking about how do I actually do + + align:start position:0% +start talking about how do I actually do + + + align:start position:0% +start talking about how do I actually do +things like design our inductors have a + + align:start position:0% +things like design our inductors have a + + + align:start position:0% +things like design our inductors have a +great day \ No newline at end of file diff --git a/t2hNMFoIv8w.txt b/t2hNMFoIv8w.txt new file mode 100644 index 0000000000000000000000000000000000000000..3dbd83d11b1b88b4d8669ffb2bb2703f9567f146 --- /dev/null +++ b/t2hNMFoIv8w.txt @@ -0,0 +1,8272 @@ +align:start position:0% + +The following content is provided under + + align:start position:0% +The following content is provided under + + + align:start position:0% +The following content is provided under +a Creative Common License. Your support + + align:start position:0% +a Creative Common License. Your support + + + align:start position:0% +a Creative Common License. Your support +will help MIT Open Courseware continue + + align:start position:0% +will help MIT Open Courseware continue + + + align:start position:0% +will help MIT Open Courseware continue +to offer high-quality educational + + align:start position:0% +to offer high-quality educational + + + align:start position:0% +to offer high-quality educational +resources for free. To make a donation + + align:start position:0% +resources for free. To make a donation + + + align:start position:0% +resources for free. To make a donation +or view additional materials from + + align:start position:0% +or view additional materials from + + + align:start position:0% +or view additional materials from +hundreds of MIT courses, visit MIT Open + + align:start position:0% +hundreds of MIT courses, visit MIT Open + + + align:start position:0% +hundreds of MIT courses, visit MIT Open +Courseware at ocw.mmit.edu. + + align:start position:0% + + + + align:start position:0% + +Hello. + + align:start position:0% +Hello. + + + align:start position:0% +Hello. +So, welcome to the last lecture in + + align:start position:0% +So, welcome to the last lecture in + + + align:start position:0% +So, welcome to the last lecture in +003. So, there are more lectures + + align:start position:0% +003. So, there are more lectures + + + align:start position:0% +003. So, there are more lectures +scheduled, but I don't believe in trying + + align:start position:0% +scheduled, but I don't believe in trying + + + align:start position:0% +scheduled, but I don't believe in trying +to cram new material in the last couple + + align:start position:0% +to cram new material in the last couple + + + align:start position:0% +to cram new material in the last couple +of hours before the exam. So, no new + + align:start position:0% +of hours before the exam. So, no new + + + align:start position:0% +of hours before the exam. So, no new +material after today, although it will + + align:start position:0% +material after today, although it will + + + align:start position:0% +material after today, although it will +be helpful if you continue to try to + + align:start position:0% +be helpful if you continue to try to + + + align:start position:0% +be helpful if you continue to try to +work on problems and try to u + + align:start position:0% +work on problems and try to u + + + align:start position:0% +work on problems and try to u +internalize what we did more more + + align:start position:0% +internalize what we did more more + + + align:start position:0% +internalize what we did more more +recently. That's the idea. So, I'm not + + align:start position:0% +recently. That's the idea. So, I'm not + + + align:start position:0% +recently. That's the idea. So, I'm not +trying to pump new information in. That + + align:start position:0% +trying to pump new information in. That + + + align:start position:0% +trying to pump new information in. That +doesn't mean that there are things there + + align:start position:0% +doesn't mean that there are things there + + + align:start position:0% +doesn't mean that there are things there +aren't things that you should be doing. + + align:start position:0% +aren't things that you should be doing. + + + align:start position:0% +aren't things that you should be doing. +Okay. But uh after today, no new + + align:start position:0% +Okay. But uh after today, no new + + + align:start position:0% +Okay. But uh after today, no new +information. In fact, today there's no + + align:start position:0% +information. In fact, today there's no + + + align:start position:0% +information. In fact, today there's no +new + + align:start position:0% +new + + + align:start position:0% +new +information. There will be a session on + + align:start position:0% +information. There will be a session on + + + align:start position:0% +information. There will be a session on +Tuesday, but the idea is primarily to + + align:start position:0% +Tuesday, but the idea is primarily to + + + align:start position:0% +Tuesday, but the idea is primarily to +get feedback from you + + align:start position:0% +get feedback from you + + + align:start position:0% +get feedback from you +people. As I mentioned last time, we've + + align:start position:0% +people. As I mentioned last time, we've + + + align:start position:0% +people. As I mentioned last time, we've +changed a lot of things. We change a lot + + align:start position:0% +changed a lot of things. We change a lot + + + align:start position:0% +changed a lot of things. We change a lot +of things every term. And our primary + + align:start position:0% +of things every term. And our primary + + + align:start position:0% +of things every term. And our primary +source of information is the end of term + + align:start position:0% +source of information is the end of term + + + align:start position:0% +source of information is the end of term +surveys. Tell us what worked. Tell us + + align:start position:0% +surveys. Tell us what worked. Tell us + + + align:start position:0% +surveys. Tell us what worked. Tell us +what didn't work. Tell us what you like. + + align:start position:0% +what didn't work. Tell us what you like. + + + align:start position:0% +what didn't work. Tell us what you like. +Tell us what you didn't like. If you + + align:start position:0% +Tell us what you didn't like. If you + + + align:start position:0% +Tell us what you didn't like. If you +didn't like the electronic submission of + + align:start position:0% +didn't like the electronic submission of + + + align:start position:0% +didn't like the electronic submission of +homework, tell us. If you didn't like + + align:start position:0% +homework, tell us. If you didn't like + + + align:start position:0% +homework, tell us. If you didn't like +the tutor, tell us. If you would rather + + align:start position:0% +the tutor, tell us. If you would rather + + + align:start position:0% +the tutor, tell us. If you would rather +have individual office hours instead of + + align:start position:0% +have individual office hours instead of + + + align:start position:0% +have individual office hours instead of +block office hours, it's a good chance + + align:start position:0% +block office hours, it's a good chance + + + align:start position:0% +block office hours, it's a good chance +for you to tell us um what you think. + + align:start position:0% +for you to tell us um what you think. + + + align:start position:0% +for you to tell us um what you think. +And it's especially important that you + + align:start position:0% +And it's especially important that you + + + align:start position:0% +And it's especially important that you +fill out the uh online subject + + align:start position:0% +fill out the uh online subject + + + align:start position:0% +fill out the uh online subject +evaluation. So, please, if you have a + + align:start position:0% +evaluation. So, please, if you have a + + + align:start position:0% +evaluation. So, please, if you have a +laptop with a certificate on it, feel + + align:start position:0% +laptop with a certificate on it, feel + + + align:start position:0% +laptop with a certificate on it, feel +free to bring it to lecture next time. + + align:start position:0% +free to bring it to lecture next time. + + + align:start position:0% +free to bring it to lecture next time. +Uh that's one of the main ideas, but + + align:start position:0% +Uh that's one of the main ideas, but + + + align:start position:0% +Uh that's one of the main ideas, but +we'll also spend some time just + + align:start position:0% +we'll also spend some time just + + + align:start position:0% +we'll also spend some time just +discussing what uh what you think uh + + align:start position:0% +discussing what uh what you think uh + + + align:start position:0% +discussing what uh what you think uh +what you would suggest for improvements + + align:start position:0% +what you would suggest for improvements + + + align:start position:0% +what you would suggest for improvements +for next + + align:start position:0% +for next + + + align:start position:0% +for next +time. Questions or + + align:start position:0% + + + + align:start position:0% + +comments? Okay. So today is mostly just + + align:start position:0% +comments? Okay. So today is mostly just + + + align:start position:0% +comments? Okay. So today is mostly just +for + + align:start position:0% +for + + + align:start position:0% +for +fun. Today is mostly just to tell you + + align:start position:0% +fun. Today is mostly just to tell you + + + align:start position:0% +fun. Today is mostly just to tell you +about the way 63 plays out in + + align:start position:0% +about the way 63 plays out in + + + align:start position:0% +about the way 63 plays out in +technologies that you might have some uh + + align:start position:0% +technologies that you might have some uh + + + align:start position:0% +technologies that you might have some uh +interest in. And I chose a technology + + align:start position:0% +interest in. And I chose a technology + + + align:start position:0% +interest in. And I chose a technology +that I am particularly interested in + + align:start position:0% +that I am particularly interested in + + + align:start position:0% +that I am particularly interested in +because I've, as I probably have + + align:start position:0% +because I've, as I probably have + + + align:start position:0% +because I've, as I probably have +mentioned in the past, like many of you, + + align:start position:0% +mentioned in the past, like many of you, + + + align:start position:0% +mentioned in the past, like many of you, +I was afflicted with an addiction of + + align:start position:0% +I was afflicted with an addiction of + + + align:start position:0% +I was afflicted with an addiction of +with music at about your age. I + + align:start position:0% +with music at about your age. I + + + align:start position:0% +with music at about your age. I +recovered. You will too. + + align:start position:0% +recovered. You will too. + + + align:start position:0% +recovered. You will too. +Um, but I was very interested in it. It + + align:start position:0% +Um, but I was very interested in it. It + + + align:start position:0% +Um, but I was very interested in it. It +was a very hot topic. And I want to talk + + align:start position:0% +was a very hot topic. And I want to talk + + + align:start position:0% +was a very hot topic. And I want to talk +about some of the things that 003 has + + align:start position:0% +about some of the things that 003 has + + + align:start position:0% +about some of the things that 003 has +done to make that industry very + + align:start position:0% +done to make that industry very + + + align:start position:0% +done to make that industry very +different today from what it was when I + + align:start position:0% +different today from what it was when I + + + align:start position:0% +different today from what it was when I +was an + + align:start position:0% +was an + + + align:start position:0% +was an +undergraduate. It may not surprise + + align:start position:0% +undergraduate. It may not surprise + + + align:start position:0% +undergraduate. It may not surprise +you, but it surprises + + align:start position:0% +you, but it surprises + + + align:start position:0% +you, but it surprises +me that the technology that we used was + + align:start position:0% +me that the technology that we used was + + + align:start position:0% +me that the technology that we used was +really not very different from the + + align:start position:0% +really not very different from the + + + align:start position:0% +really not very different from the +technology that the inventor invented. + + align:start position:0% +technology that the inventor invented. + + + align:start position:0% +technology that the inventor invented. +So who invented the uh photograph? + + align:start position:0% +So who invented the uh photograph? + + + align:start position:0% +So who invented the uh photograph? +You can look at the notes. You're + + align:start position:0% +You can look at the notes. You're + + + align:start position:0% +You can look at the notes. You're +supposed to know + + align:start position:0% + + + + align:start position:0% + +that. Just shout, right? Makes me feel + + align:start position:0% +that. Just shout, right? Makes me feel + + + align:start position:0% +that. Just shout, right? Makes me feel +better. Thank you, + + align:start position:0% +better. Thank you, + + + align:start position:0% +better. Thank you, +Edison. So, Edison was, of course, a + + align:start position:0% +Edison. So, Edison was, of course, a + + + align:start position:0% +Edison. So, Edison was, of course, a +genius uh and a prolific inventor. He + + align:start position:0% +genius uh and a prolific inventor. He + + + align:start position:0% +genius uh and a prolific inventor. He +was interested at the time he invented + + align:start position:0% +was interested at the time he invented + + + align:start position:0% +was interested at the time he invented +the photograph, he was interested in two + + align:start position:0% +the photograph, he was interested in two + + + align:start position:0% +the photograph, he was interested in two +things, two things that he was trying to + + align:start position:0% +things, two things that he was trying to + + + align:start position:0% +things, two things that he was trying to +draw, um relations between, telegraphy + + align:start position:0% +draw, um relations between, telegraphy + + + align:start position:0% +draw, um relations between, telegraphy +and telefan. We talked about telegraphy + + align:start position:0% +and telefan. We talked about telegraphy + + + align:start position:0% +and telefan. We talked about telegraphy +before. Telegraphy, telegraph was a way + + align:start position:0% +before. Telegraphy, telegraph was a way + + + align:start position:0% +before. Telegraphy, telegraph was a way +of getting messages + + align:start position:0% +of getting messages + + + align:start position:0% +of getting messages +pointtooint. So person A wanted to get a + + align:start position:0% +pointtooint. So person A wanted to get a + + + align:start position:0% +pointtooint. So person A wanted to get a +message to person B and it would be + + align:start position:0% +message to person B and it would be + + + align:start position:0% +message to person B and it would be +transmitted via the telegraph system. + + align:start position:0% +transmitted via the telegraph system. + + + align:start position:0% +transmitted via the telegraph system. +Now I kind of oversimplified the way the + + align:start position:0% +Now I kind of oversimplified the way the + + + align:start position:0% +Now I kind of oversimplified the way the +telegraph system worked when I talked + + align:start position:0% +telegraph system worked when I talked + + + align:start position:0% +telegraph system worked when I talked +about it the last time. It really worked + + align:start position:0% +about it the last time. It really worked + + + align:start position:0% +about it the last time. It really worked +a lot more like message + + align:start position:0% +a lot more like message + + + align:start position:0% +a lot more like message +passing than you might have thought. + + align:start position:0% +passing than you might have thought. + + + align:start position:0% +passing than you might have thought. +What would happen is that there wouldn't + + align:start position:0% +What would happen is that there wouldn't + + + align:start position:0% +What would happen is that there wouldn't +be a direct connection between person A + + align:start position:0% +be a direct connection between person A + + + align:start position:0% +be a direct connection between person A +and person B. it might have to go + + align:start position:0% +and person B. it might have to go + + + align:start position:0% +and person B. it might have to go +through six + + align:start position:0% +through six + + + align:start position:0% +through six +relays. So in order to get to + + align:start position:0% +relays. So in order to get to + + + align:start position:0% +relays. So in order to get to +California, it might be important that + + align:start position:0% +California, it might be important that + + + align:start position:0% +California, it might be important that +um a message that originated in Boston + + align:start position:0% +um a message that originated in Boston + + + align:start position:0% +um a message that originated in Boston +would go to New York and from New York + + align:start position:0% +would go to New York and from New York + + + align:start position:0% +would go to New York and from New York +to I don't know Pennsylvania, from + + align:start position:0% +to I don't know Pennsylvania, from + + + align:start position:0% +to I don't know Pennsylvania, from +Pennsylvania to Chicago, uh etc. So it + + align:start position:0% +Pennsylvania to Chicago, uh etc. So it + + + align:start position:0% +Pennsylvania to Chicago, uh etc. So it +there may not be a direct route over + + align:start position:0% +there may not be a direct route over + + + align:start position:0% +there may not be a direct route over +long distances. So the way that was + + align:start position:0% +long distances. So the way that was + + + align:start position:0% +long distances. So the way that was +done, you would take your message to + + align:start position:0% +done, you would take your message to + + + align:start position:0% +done, you would take your message to +telegraph office A. The operator would + + align:start position:0% +telegraph office A. The operator would + + + align:start position:0% +telegraph office A. The operator would +uh key it in. It would get written down + + align:start position:0% +uh key it in. It would get written down + + + align:start position:0% +uh key it in. It would get written down +by the receiver, say in New + + align:start position:0% +by the receiver, say in New + + + align:start position:0% +by the receiver, say in New +York, who would listen to the message, + + align:start position:0% +York, who would listen to the message, + + + align:start position:0% +York, who would listen to the message, +write it out, basically reproducing your + + align:start position:0% +write it out, basically reproducing your + + + align:start position:0% +write it out, basically reproducing your +message there, then key it in to the + + align:start position:0% +message there, then key it in to the + + + align:start position:0% +message there, then key it in to the +next + + align:start position:0% +next + + + align:start position:0% +next +relay. So it might actually be keyed in + + align:start position:0% +relay. So it might actually be keyed in + + + align:start position:0% +relay. So it might actually be keyed in +uh a dozen times before it hits the + + align:start position:0% +uh a dozen times before it hits the + + + align:start position:0% +uh a dozen times before it hits the +final destination. And that was tedious, + + align:start position:0% +final destination. And that was tedious, + + + align:start position:0% +final destination. And that was tedious, +laborious, hard. And um Edison was + + align:start position:0% +laborious, hard. And um Edison was + + + align:start position:0% +laborious, hard. And um Edison was +interested in uh fixing that. And to do + + align:start position:0% +interested in uh fixing that. And to do + + + align:start position:0% +interested in uh fixing that. And to do +so, he invented a paper tape system so + + align:start position:0% +so, he invented a paper tape system so + + + align:start position:0% +so, he invented a paper tape system so +that the receiver wouldn't need to + + align:start position:0% +that the receiver wouldn't need to + + + align:start position:0% +that the receiver wouldn't need to +listen. It would just punch out paper + + align:start position:0% +listen. It would just punch out paper + + + align:start position:0% +listen. It would just punch out paper +tape as the as the clicks came in. So as + + align:start position:0% +tape as the as the clicks came in. So as + + + align:start position:0% +tape as the as the clicks came in. So as +the dots and dashes came in, it would + + align:start position:0% +the dots and dashes came in, it would + + + align:start position:0% +the dots and dashes came in, it would +make holes in paper. The holes in paper + + align:start position:0% +make holes in paper. The holes in paper + + + align:start position:0% +make holes in paper. The holes in paper +then could be used to transmit to the + + align:start position:0% +then could be used to transmit to the + + + align:start position:0% +then could be used to transmit to the +next station. So Edison did that. + + align:start position:0% +next station. So Edison did that. + + + align:start position:0% +next station. So Edison did that. +He was interested in thinking about + + align:start position:0% +He was interested in thinking about + + + align:start position:0% +He was interested in thinking about +whether you could do the same sort of + + align:start position:0% +whether you could do the same sort of + + + align:start position:0% +whether you could do the same sort of +thing with other kinds of signals + + align:start position:0% +thing with other kinds of signals + + + align:start position:0% +thing with other kinds of signals +besides telegraph signals. And that's + + align:start position:0% +besides telegraph signals. And that's + + + align:start position:0% +besides telegraph signals. And that's +the origin of the photograph. He was + + align:start position:0% +the origin of the photograph. He was + + + align:start position:0% +the origin of the photograph. He was +interested in could you send a voice + + align:start position:0% +interested in could you send a voice + + + align:start position:0% +interested in could you send a voice +message to a relay have it automatically + + align:start position:0% +message to a relay have it automatically + + + align:start position:0% +message to a relay have it automatically +recorded so that it could then be + + align:start position:0% +recorded so that it could then be + + + align:start position:0% +recorded so that it could then be +rebroadcast over the next link. So he + + align:start position:0% +rebroadcast over the next link. So he + + + align:start position:0% +rebroadcast over the next link. So he +was kind of imagining a telephone + + align:start position:0% +was kind of imagining a telephone + + + align:start position:0% +was kind of imagining a telephone +network that was based on the same + + align:start position:0% +network that was based on the same + + + align:start position:0% +network that was based on the same +principle that the telegraph network had + + align:start position:0% +principle that the telegraph network had + + + align:start position:0% +principle that the telegraph network had +been. So the idea was to uh try to + + align:start position:0% +been. So the idea was to uh try to + + + align:start position:0% +been. So the idea was to uh try to +record an audio signal of the type that + + align:start position:0% +record an audio signal of the type that + + + align:start position:0% +record an audio signal of the type that +would come across a um telephone + + align:start position:0% +would come across a um telephone + + + align:start position:0% +would come across a um telephone +wire. So uh he got together with his aid + + align:start position:0% +wire. So uh he got together with his aid + + + align:start position:0% +wire. So uh he got together with his aid +bachelor and made this drawing. This was + + align:start position:0% +bachelor and made this drawing. This was + + + align:start position:0% +bachelor and made this drawing. This was +u + + align:start position:0% +u + + + align:start position:0% +u +1877 and 30 hours later kind of rapid + + align:start position:0% +1877 and 30 hours later kind of rapid + + + align:start position:0% +1877 and 30 hours later kind of rapid +prototyping for the time uh his + + align:start position:0% +prototyping for the time uh his + + + align:start position:0% +prototyping for the time uh his +machinist made this. So that's the first + + align:start position:0% +machinist made this. So that's the first + + + align:start position:0% +machinist made this. So that's the first +photograph. The idea was uh you wrap + + align:start position:0% +photograph. The idea was uh you wrap + + + align:start position:0% +photograph. The idea was uh you wrap +that disc with a piece of wax + + align:start position:0% +that disc with a piece of wax + + + align:start position:0% +that disc with a piece of wax +paper. You turn the + + align:start position:0% +paper. You turn the + + + align:start position:0% +paper. You turn the +crank. As you turn the crank, uh this + + align:start position:0% +crank. As you turn the crank, uh this + + + align:start position:0% +crank. As you turn the crank, uh this +thing is connected to a screw so that + + align:start position:0% +thing is connected to a screw so that + + + align:start position:0% +thing is connected to a screw so that +it's moving this way at the same time + + align:start position:0% +it's moving this way at the same time + + + align:start position:0% +it's moving this way at the same time +this big thing is going around that way. + + align:start position:0% +this big thing is going around that way. + + + align:start position:0% +this big thing is going around that way. +This is a diaphragm so that you shout in + + align:start position:0% +This is a diaphragm so that you shout in + + + align:start position:0% +This is a diaphragm so that you shout in +here and there's a needle connected on + + align:start position:0% +here and there's a needle connected on + + + align:start position:0% +here and there's a needle connected on +the other end so that as you shout the + + align:start position:0% +the other end so that as you shout the + + + align:start position:0% +the other end so that as you shout the +needle gets moved with audio frequencies + + align:start position:0% +needle gets moved with audio frequencies + + + align:start position:0% +needle gets moved with audio frequencies +contained in your voice. Okay. So how do + + align:start position:0% +contained in your voice. Okay. So how do + + + align:start position:0% +contained in your voice. Okay. So how do +you do this then? So you grab the + + align:start position:0% +you do this then? So you grab the + + + align:start position:0% +you do this then? So you grab the +handle, you put a new sheet of wax paper + + align:start position:0% +handle, you put a new sheet of wax paper + + + align:start position:0% +handle, you put a new sheet of wax paper +on it, you grab the handle, you turn at + + align:start position:0% +on it, you grab the handle, you turn at + + + align:start position:0% +on it, you grab the handle, you turn at +a constant speed and shout. + + align:start position:0% +a constant speed and shout. + + + align:start position:0% +a constant speed and shout. +Okay, it took some + + align:start position:0% +Okay, it took some + + + align:start position:0% +Okay, it took some +coordination. Uh, the remarkable thing + + align:start position:0% +coordination. Uh, the remarkable thing + + + align:start position:0% +coordination. Uh, the remarkable thing +is it + + align:start position:0% +is it + + + align:start position:0% +is it +worked. So Edison said, "Mary had a + + align:start position:0% +worked. So Edison said, "Mary had a + + + align:start position:0% +worked. So Edison said, "Mary had a +little + + align:start position:0% +little + + + align:start position:0% +little +lamb." And on replaying it, the device + + align:start position:0% +lamb." And on replaying it, the device + + + align:start position:0% +lamb." And on replaying it, the device +said, "Mary had a little lamb." It was a + + align:start position:0% +said, "Mary had a little lamb." It was a + + + align:start position:0% +said, "Mary had a little lamb." It was a +the very first try it worked. Now, it + + align:start position:0% +the very first try it worked. Now, it + + + align:start position:0% +the very first try it worked. Now, it +didn't work all that great. What do you + + align:start position:0% +didn't work all that great. What do you + + + align:start position:0% +didn't work all that great. What do you +suppose happened? + + align:start position:0% + + + + align:start position:0% + +Noise. Of course, there was noise. Yes. + + align:start position:0% +Noise. Of course, there was noise. Yes. + + + align:start position:0% +Noise. Of course, there was noise. Yes. +frequency was + + align:start position:0% +frequency was + + + align:start position:0% +frequency was +terrible. Anything more disastrous? + + align:start position:0% +terrible. Anything more disastrous? + + + align:start position:0% +terrible. Anything more disastrous? +Yeah. + + align:start position:0% +Yeah. + + + align:start position:0% +Yeah. +Cranking is not at all constant. So you + + align:start position:0% +Cranking is not at all constant. So you + + + align:start position:0% +Cranking is not at all constant. So you +can make it sound like uh Alvin the + + align:start position:0% +can make it sound like uh Alvin the + + + align:start position:0% +can make it sound like uh Alvin the +Chipmunk if you like. + + align:start position:0% + + + + align:start position:0% + +Uh something + + align:start position:0% + + + + align:start position:0% + +worse. How long do you think the + + align:start position:0% +worse. How long do you think the + + + align:start position:0% +worse. How long do you think the +recording lasted? + + align:start position:0% + + + + align:start position:0% + +Yeah, about once. + + align:start position:0% + + + + align:start position:0% + +So, so the problem was to get the energy + + align:start position:0% +So, so the problem was to get the energy + + + align:start position:0% +So, so the problem was to get the energy +back + + align:start position:0% +back + + + align:start position:0% +back +out, right? You have to, so after + + align:start position:0% +out, right? You have to, so after + + + align:start position:0% +out, right? You have to, so after +recording, right? So, you clean sheet of + + align:start position:0% +recording, right? So, you clean sheet of + + + align:start position:0% +recording, right? So, you clean sheet of +wax paper, crank, crank, crank, yell, + + align:start position:0% +wax paper, crank, crank, crank, yell, + + + align:start position:0% +wax paper, crank, crank, crank, yell, +scream, and now reset the needle to the + + align:start position:0% +scream, and now reset the needle to the + + + align:start position:0% +scream, and now reset the needle to the +beginning and now crank without + + align:start position:0% +beginning and now crank without + + + align:start position:0% +beginning and now crank without +screaming. + + align:start position:0% +screaming. + + + align:start position:0% +screaming. +In order to get the the message back + + align:start position:0% +In order to get the the message back + + + align:start position:0% +In order to get the the message back +out, you had to push on the needle so + + align:start position:0% +out, you had to push on the needle so + + + align:start position:0% +out, you had to push on the needle so +that it would follow the indentations on + + align:start position:0% +that it would follow the indentations on + + + align:start position:0% +that it would follow the indentations on +the + + align:start position:0% +the + + + align:start position:0% +the +wax. But if you pushed hard enough for + + align:start position:0% +wax. But if you pushed hard enough for + + + align:start position:0% +wax. But if you pushed hard enough for +it to follow it, what would + + align:start position:0% +it to follow it, what would + + + align:start position:0% +it to follow it, what would +happen? It erased the message, right? So + + align:start position:0% +happen? It erased the message, right? So + + + align:start position:0% +happen? It erased the message, right? So +it was kind of a destructive readout. It + + align:start position:0% +it was kind of a destructive readout. It + + + align:start position:0% +it was kind of a destructive readout. It +was a it didn't last very long because + + align:start position:0% +was a it didn't last very long because + + + align:start position:0% +was a it didn't last very long because +the act of reading it back out tended to + + align:start position:0% +the act of reading it back out tended to + + + align:start position:0% +the act of reading it back out tended to +erase it. So he redid the thing with uh + + align:start position:0% +erase it. So he redid the thing with uh + + + align:start position:0% +erase it. So he redid the thing with uh +tinfoil that worked much better and in + + align:start position:0% +tinfoil that worked much better and in + + + align:start position:0% +tinfoil that worked much better and in +fact it caught on like like + + align:start position:0% +fact it caught on like like + + + align:start position:0% +fact it caught on like like +overnight. So within two years he was + + align:start position:0% +overnight. So within two years he was + + + align:start position:0% +overnight. So within two years he was +invited to the Nationalmies of Sciences + + align:start position:0% +invited to the Nationalmies of Sciences + + + align:start position:0% +invited to the Nationalmies of Sciences +to give a talk on this. That's him + + align:start position:0% +to give a talk on this. That's him + + + align:start position:0% +to give a talk on this. That's him +posing at the National Academy of + + align:start position:0% +posing at the National Academy of + + + align:start position:0% +posing at the National Academy of +Sciences with his then + + align:start position:0% +Sciences with his then + + + align:start position:0% +Sciences with his then +photograph. They loved + + align:start position:0% +photograph. They loved + + + align:start position:0% +photograph. They loved +it. + + align:start position:0% +it. + + + align:start position:0% +it. +Now despite the fact they loved it, + + align:start position:0% +Now despite the fact they loved it, + + + align:start position:0% +Now despite the fact they loved it, +nobody knew what to do with it. + + align:start position:0% +nobody knew what to do with it. + + + align:start position:0% +nobody knew what to do with it. +Everybody thought it was just the + + align:start position:0% +Everybody thought it was just the + + + align:start position:0% +Everybody thought it was just the +neatest thing in the world, but they + + align:start position:0% +neatest thing in the world, but they + + + align:start position:0% +neatest thing in the world, but they +didn't have a clue what to do with it. + + align:start position:0% +didn't have a clue what to do with it. + + + align:start position:0% +didn't have a clue what to do with it. +And of course, Edison wanted was a bit + + align:start position:0% +And of course, Edison wanted was a bit + + + align:start position:0% +And of course, Edison wanted was a bit +self-promoting, so he wrote articles + + align:start position:0% +self-promoting, so he wrote articles + + + align:start position:0% +self-promoting, so he wrote articles +about it and tried to explain. He put in + + align:start position:0% +about it and tried to explain. He put in + + + align:start position:0% +about it and tried to explain. He put in +the patent. In the patent, he listed + + align:start position:0% +the patent. In the patent, he listed + + + align:start position:0% +the patent. In the patent, he listed +about seven or eight things you could do + + align:start position:0% +about seven or eight things you could do + + + align:start position:0% +about seven or eight things you could do +with this thing. Today, they sound a + + align:start position:0% +with this thing. Today, they sound a + + + align:start position:0% +with this thing. Today, they sound a +little far-fetched. + + align:start position:0% +little far-fetched. + + + align:start position:0% +little far-fetched. +um recording uh important historical + + align:start position:0% +um recording uh important historical + + + align:start position:0% +um recording uh important historical +addresses, medical + + align:start position:0% +addresses, medical + + + align:start position:0% +addresses, medical +transcription, the one that seems most + + align:start position:0% +transcription, the one that seems most + + + align:start position:0% +transcription, the one that seems most +uh I don't know, sort of gruesome to me, + + align:start position:0% +uh I don't know, sort of gruesome to me, + + + align:start position:0% +uh I don't know, sort of gruesome to me, +recording the last will and testament of + + align:start position:0% +recording the last will and testament of + + + align:start position:0% +recording the last will and testament of +a person as they're + + align:start position:0% +a person as they're + + + align:start position:0% +a person as they're +dying. Now, that sounds gruesome to + + align:start position:0% +dying. Now, that sounds gruesome to + + + align:start position:0% +dying. Now, that sounds gruesome to +me, but imagine what it was like back + + align:start position:0% +me, but imagine what it was like back + + + align:start position:0% +me, but imagine what it was like back +then. Back then, nobody had ever heard + + align:start position:0% +then. Back then, nobody had ever heard + + + align:start position:0% +then. Back then, nobody had ever heard +somebody's voice who was not + + align:start position:0% + + + + align:start position:0% + +alive. I mean, the technology had didn't + + align:start position:0% +alive. I mean, the technology had didn't + + + align:start position:0% +alive. I mean, the technology had didn't +exist. So, all of a sudden, he's + + align:start position:0% +exist. So, all of a sudden, he's + + + align:start position:0% +exist. So, all of a sudden, he's +proposing to record the dying breath of + + align:start position:0% +proposing to record the dying breath of + + + align:start position:0% +proposing to record the dying breath of +it kind of mortified everybody. What + + align:start position:0% +it kind of mortified everybody. What + + + align:start position:0% +it kind of mortified everybody. What +Edison didn't like was the idea that it + + align:start position:0% +Edison didn't like was the idea that it + + + align:start position:0% +Edison didn't like was the idea that it +would be used for music. Okay, that was + + align:start position:0% +would be used for music. Okay, that was + + + align:start position:0% +would be used for music. Okay, that was +trivial. He was doing important + + align:start position:0% +trivial. He was doing important + + + align:start position:0% +trivial. He was doing important +science. So he didn't like the idea that + + align:start position:0% +science. So he didn't like the idea that + + + align:start position:0% +science. So he didn't like the idea that +this would be used for music and so he + + align:start position:0% +this would be used for music and so he + + + align:start position:0% +this would be used for music and so he +downplayed that his entire life. + + align:start position:0% +downplayed that his entire life. + + + align:start position:0% +downplayed that his entire life. +Nevertheless, the commercial + + align:start position:0% +Nevertheless, the commercial + + + align:start position:0% +Nevertheless, the commercial +success was + + align:start position:0% +success was + + + align:start position:0% +success was +music. He was trying to promote this as + + align:start position:0% +music. He was trying to promote this as + + + align:start position:0% +music. He was trying to promote this as +a system for + + align:start position:0% +a system for + + + align:start position:0% +a system for +recording speech, right? Medical + + align:start position:0% +recording speech, right? Medical + + + align:start position:0% +recording speech, right? Medical +transcription, dying breaths, historical + + align:start position:0% +transcription, dying breaths, historical + + + align:start position:0% +transcription, dying breaths, historical +talks. That didn't really catch on. This + + align:start position:0% +talks. That didn't really catch on. This + + + align:start position:0% +talks. That didn't really catch on. This +was a playback device. + + align:start position:0% +was a playback device. + + + align:start position:0% +was a playback device. +This really did catch on. Uh this was + + align:start position:0% +This really did catch on. Uh this was + + + align:start position:0% +This really did catch on. Uh this was +about 60 years later. It's virtually + + align:start position:0% +about 60 years later. It's virtually + + + align:start position:0% +about 60 years later. It's virtually +identical. It became a piece of + + align:start position:0% +identical. It became a piece of + + + align:start position:0% +identical. It became a piece of +furniture that everybody had in their + + align:start position:0% +furniture that everybody had in their + + + align:start position:0% +furniture that everybody had in their +house. Uh the cylinders had gone back to + + align:start position:0% +house. Uh the cylinders had gone back to + + + align:start position:0% +house. Uh the cylinders had gone back to +wax. Alexander Graanbell had worked on + + align:start position:0% +wax. Alexander Graanbell had worked on + + + align:start position:0% +wax. Alexander Graanbell had worked on +the problem. He figured out how to make + + align:start position:0% +the problem. He figured out how to make + + + align:start position:0% +the problem. He figured out how to make +long-lasting + + align:start position:0% +long-lasting + + + align:start position:0% +long-lasting +wax. This crank cranked a + + align:start position:0% +wax. This crank cranked a + + + align:start position:0% +wax. This crank cranked a +spring so you could crank it up, but + + align:start position:0% +spring so you could crank it up, but + + + align:start position:0% +spring so you could crank it up, but +over time it would play. So, you didn't + + align:start position:0% +over time it would play. So, you didn't + + + align:start position:0% +over time it would play. So, you didn't +need to go at exactly the right speed + + align:start position:0% +need to go at exactly the right speed + + + align:start position:0% +need to go at exactly the right speed +anymore. Uh, a number of big + + align:start position:0% +anymore. Uh, a number of big + + + align:start position:0% +anymore. Uh, a number of big +improvements. The cylinders held two + + align:start position:0% +improvements. The cylinders held two + + + align:start position:0% +improvements. The cylinders held two +minutes of recording, so they weren't + + align:start position:0% +minutes of recording, so they weren't + + + align:start position:0% +minutes of recording, so they weren't +exactly long + + align:start position:0% +exactly long + + + align:start position:0% +exactly long +playing. Okay. This was uh the same + + align:start position:0% +playing. Okay. This was uh the same + + + align:start position:0% +playing. Okay. This was uh the same +model of uh photograph I had in college. + + align:start position:0% +model of uh photograph I had in college. + + + align:start position:0% +model of uh photograph I had in college. +Okay. And it's actually remarkably + + align:start position:0% +Okay. And it's actually remarkably + + + align:start position:0% +Okay. And it's actually remarkably +similar. So, uh there's some + + align:start position:0% +similar. So, uh there's some + + + align:start position:0% +similar. So, uh there's some +differences. + + align:start position:0% +differences. + + + align:start position:0% +differences. +There was no + + align:start position:0% +There was no + + + align:start position:0% +There was no +crank. We had + + align:start position:0% +crank. We had + + + align:start position:0% +crank. We had +electricity. It had a motor. So, the + + align:start position:0% +electricity. It had a motor. So, the + + + align:start position:0% +electricity. It had a motor. So, the +motor propelled it. It was no longer a + + align:start position:0% +motor propelled it. It was no longer a + + + align:start position:0% +motor propelled it. It was no longer a +cylinder. Now, it's a disc. There was no + + align:start position:0% + + + + align:start position:0% + +screw. So, how does the needle track the + + align:start position:0% +screw. So, how does the needle track the + + + align:start position:0% +screw. So, how does the needle track the +the grooves if there's no screw? + + align:start position:0% + + + + align:start position:0% + +There's a there's a spiral. So, the the + + align:start position:0% +There's a there's a spiral. So, the the + + + align:start position:0% +There's a there's a spiral. So, the the +records had a spiral. That's right. + + align:start position:0% +records had a spiral. That's right. + + + align:start position:0% +records had a spiral. That's right. +What held what made the re So this was + + align:start position:0% +What held what made the re So this was + + + align:start position:0% +What held what made the re So this was +the uh thing that read the the grooves. + + align:start position:0% +the uh thing that read the the grooves. + + + align:start position:0% +the uh thing that read the the grooves. +What what held that in the + + align:start position:0% +What what held that in the + + + align:start position:0% +What what held that in the +groove? That was + + align:start position:0% +groove? That was + + + align:start position:0% +groove? That was +gravity, right? So it was the same kind + + align:start position:0% +gravity, right? So it was the same kind + + + align:start position:0% +gravity, right? So it was the same kind +of idea. You had to push on the the + + align:start position:0% +of idea. You had to push on the the + + + align:start position:0% +of idea. You had to push on the the +needle to hold the needle in the groove + + align:start position:0% +needle to hold the needle in the groove + + + align:start position:0% +needle to hold the needle in the groove +so that the needle wouldn't uh so that + + align:start position:0% +so that the needle wouldn't uh so that + + + align:start position:0% +so that the needle wouldn't uh so that +the needle could rec uh report the + + align:start position:0% +the needle could rec uh report the + + + align:start position:0% +the needle could rec uh report the +vibrations that were recorded there. + + align:start position:0% +vibrations that were recorded there. + + + align:start position:0% +vibrations that were recorded there. +Okay, but this was much classier than + + align:start position:0% +Okay, but this was much classier than + + + align:start position:0% +Okay, but this was much classier than +than uh the version in Edison's time. Uh + + align:start position:0% +than uh the version in Edison's time. Uh + + + align:start position:0% +than uh the version in Edison's time. Uh +so in fact, you could tell how serious + + align:start position:0% +so in fact, you could tell how serious + + + align:start position:0% +so in fact, you could tell how serious +the audio file was by how by the + + align:start position:0% +the audio file was by how by the + + + align:start position:0% +the audio file was by how by the +different kinds of uh performance + + align:start position:0% +different kinds of uh performance + + + align:start position:0% +different kinds of uh performance +enhancements of of this sort of thing. + + align:start position:0% +enhancements of of this sort of thing. + + + align:start position:0% +enhancements of of this sort of thing. +So for example, + + align:start position:0% +So for example, + + + align:start position:0% +So for example, +um this little knob, this controls the + + align:start position:0% +um this little knob, this controls the + + + align:start position:0% +um this little knob, this controls the +weight, the force that's placed on the + + align:start position:0% +weight, the force that's placed on the + + + align:start position:0% +weight, the force that's placed on the +needle. If you had a good setup, you + + align:start position:0% +needle. If you had a good setup, you + + + align:start position:0% +needle. If you had a good setup, you +could set it for about 1.2 grams. If you + + align:start position:0% +could set it for about 1.2 grams. If you + + + align:start position:0% +could set it for about 1.2 grams. If you +had a bad setup, it'd go up to two + + align:start position:0% +had a bad setup, it'd go up to two + + + align:start position:0% +had a bad setup, it'd go up to two +grams. So, you could tell by by u + + align:start position:0% +grams. So, you could tell by by u + + + align:start position:0% +grams. So, you could tell by by u +uh you could tell how serious a person + + align:start position:0% +uh you could tell how serious a person + + + align:start position:0% +uh you could tell how serious a person +was by how many uh uh how much force was + + align:start position:0% +was by how many uh uh how much force was + + + align:start position:0% +was by how many uh uh how much force was +required to track. So, uh you could tell + + align:start position:0% +required to track. So, uh you could tell + + + align:start position:0% +required to track. So, uh you could tell +so for example uh the primary thing that + + align:start position:0% +so for example uh the primary thing that + + + align:start position:0% +so for example uh the primary thing that +determined how well the system worked + + align:start position:0% +determined how well the system worked + + + align:start position:0% +determined how well the system worked +was the + + align:start position:0% +was the + + + align:start position:0% +was the +cartridge. So, here's a blow up of a + + align:start position:0% +cartridge. So, here's a blow up of a + + + align:start position:0% +cartridge. So, here's a blow up of a +cartridge. + + align:start position:0% +cartridge. + + + align:start position:0% +cartridge. +cartridge. Anybody who was serious had a + + align:start position:0% +cartridge. Anybody who was serious had a + + + align:start position:0% +cartridge. Anybody who was serious had a +diamond tip needle, right? If they + + align:start position:0% +diamond tip needle, right? If they + + + align:start position:0% +diamond tip needle, right? If they +didn't have a diamond tip tip needle, + + align:start position:0% +didn't have a diamond tip tip needle, + + + align:start position:0% +didn't have a diamond tip tip needle, +you just didn't even think about them. + + align:start position:0% +you just didn't even think about them. + + + align:start position:0% +you just didn't even think about them. +So, everybody I knew had a diamond tip + + align:start position:0% +So, everybody I knew had a diamond tip + + + align:start position:0% +So, everybody I knew had a diamond tip +needle. That was just the way it was. + + align:start position:0% +needle. That was just the way it was. + + + align:start position:0% +needle. That was just the way it was. +Uh, the least expensive kind of + + align:start position:0% +Uh, the least expensive kind of + + + align:start position:0% +Uh, the least expensive kind of +cartridges was a little piece of pre pzo + + align:start position:0% +cartridges was a little piece of pre pzo + + + align:start position:0% +cartridges was a little piece of pre pzo +ceramic. The PZO ceramic was + + align:start position:0% +ceramic. The PZO ceramic was + + + align:start position:0% +ceramic. The PZO ceramic was +stiff so that as you played the records, + + align:start position:0% +stiff so that as you played the records, + + + align:start position:0% +stiff so that as you played the records, +they tended to wear out because you had + + align:start position:0% +they tended to wear out because you had + + + align:start position:0% +they tended to wear out because you had +to put a lot of force on it. + + align:start position:0% +to put a lot of force on it. + + + align:start position:0% +to put a lot of force on it. +mine. I had the V15 type 4. Okay. So, + + align:start position:0% +mine. I had the V15 type 4. Okay. So, + + + align:start position:0% +mine. I had the V15 type 4. Okay. So, +this was a magnetic device. So, there + + align:start position:0% +this was a magnetic device. So, there + + + align:start position:0% +this was a magnetic device. So, there +were tiny little electromagnets so that + + align:start position:0% +were tiny little electromagnets so that + + + align:start position:0% +were tiny little electromagnets so that +the up and down motions would be + + align:start position:0% +the up and down motions would be + + + align:start position:0% +the up and down motions would be +converted into an electrical signal by + + align:start position:0% +converted into an electrical signal by + + + align:start position:0% +converted into an electrical signal by +magnetism, not by paso electric effect. + + align:start position:0% +magnetism, not by paso electric effect. + + + align:start position:0% +magnetism, not by paso electric effect. +And you could track that with a much + + align:start position:0% +And you could track that with a much + + + align:start position:0% +And you could track that with a much +smaller force. And I should just mention + + align:start position:0% +smaller force. And I should just mention + + + align:start position:0% +smaller force. And I should just mention +just, you know, so you know that, you + + align:start position:0% +just, you know, so you know that, you + + + align:start position:0% +just, you know, so you know that, you +know, we were serious back then. So, + + align:start position:0% +know, we were serious back then. So, + + + align:start position:0% +know, we were serious back then. So, +this cost $160 then dollars. + + align:start position:0% +this cost $160 then dollars. + + + align:start position:0% +this cost $160 then dollars. +there's been a factor of six or so + + align:start position:0% +there's been a factor of six or so + + + align:start position:0% +there's been a factor of six or so +inflation. This cost + + align:start position:0% +inflation. This cost + + + align:start position:0% +inflation. This cost +$1,000, right? And if you were serious, + + align:start position:0% +$1,000, right? And if you were serious, + + + align:start position:0% +$1,000, right? And if you were serious, +you had + + align:start position:0% +you had + + + align:start position:0% +you had +these. So, + + align:start position:0% +these. So, + + + align:start position:0% +these. So, +um, that's kind of the technology as it + + align:start position:0% +um, that's kind of the technology as it + + + align:start position:0% +um, that's kind of the technology as it +existed um when I was in undergraduate + + align:start position:0% +existed um when I was in undergraduate + + + align:start position:0% +existed um when I was in undergraduate +and it was good. It had existed for over + + align:start position:0% +and it was good. It had existed for over + + + align:start position:0% +and it was good. It had existed for over +a hundred + + align:start position:0% +a hundred + + + align:start position:0% +a hundred +years, but it was still basically the + + align:start position:0% +years, but it was still basically the + + + align:start position:0% +years, but it was still basically the +same thing Edison had done. + + align:start position:0% +same thing Edison had done. + + + align:start position:0% +same thing Edison had done. +uh the media. Oh, I should show it just + + align:start position:0% +uh the media. Oh, I should show it just + + + align:start position:0% +uh the media. Oh, I should show it just +in case you've never seen a media. + + align:start position:0% +in case you've never seen a media. + + + align:start position:0% +in case you've never seen a media. +Right. So, this is a record. This was my + + align:start position:0% +Right. So, this is a record. This was my + + + align:start position:0% +Right. So, this is a record. This was my +record. + + align:start position:0% + + + + align:start position:0% + +Um and the problem is of course they + + align:start position:0% +Um and the problem is of course they + + + align:start position:0% +Um and the problem is of course they +scratch, right? So over time these + + align:start position:0% +scratch, right? So over time these + + + align:start position:0% +scratch, right? So over time these +things would scratch. So the + + align:start position:0% +things would scratch. So the + + + align:start position:0% +things would scratch. So the +technologies were things like uh how do + + align:start position:0% +technologies were things like uh how do + + + align:start position:0% +technologies were things like uh how do +you keep them from scratching? How do + + align:start position:0% +you keep them from scratching? How do + + + align:start position:0% +you keep them from scratching? How do +you wear them out? I mean you can also + + align:start position:0% +you wear them out? I mean you can also + + + align:start position:0% +you wear them out? I mean you can also +appreciate sort of where the music + + align:start position:0% +appreciate sort of where the music + + + align:start position:0% +appreciate sort of where the music +industry is coming from. This cost about + + align:start position:0% +industry is coming from. This cost about + + + align:start position:0% +industry is coming from. This cost about +$15. 15 then dollars, right? So with + + align:start position:0% +$15. 15 then dollars, right? So with + + + align:start position:0% +$15. 15 then dollars, right? So with +factor of six is about + + align:start position:0% +factor of six is about + + + align:start position:0% +factor of six is about +$100. So from the point of view of + + align:start position:0% +$100. So from the point of view of + + + align:start position:0% +$100. So from the point of view of +buying music, it was much more expensive + + align:start position:0% +buying music, it was much more expensive + + + align:start position:0% +buying music, it was much more expensive +back then. And from the point of view of + + align:start position:0% +back then. And from the point of view of + + + align:start position:0% +back then. And from the point of view of +the recording industry, think of it, you + + align:start position:0% +the recording industry, think of it, you + + + align:start position:0% +the recording industry, think of it, you +had all these addicted people wanting to + + align:start position:0% +had all these addicted people wanting to + + + align:start position:0% +had all these addicted people wanting to +buy this + + align:start position:0% +buy this + + + align:start position:0% +buy this +stuff and it wears + + align:start position:0% +stuff and it wears + + + align:start position:0% +stuff and it wears +out. So you play it for two or three + + align:start position:0% +out. So you play it for two or three + + + align:start position:0% +out. So you play it for two or three +years, you have to buy a new one. Okay? + + align:start position:0% +years, you have to buy a new one. Okay? + + + align:start position:0% +years, you have to buy a new one. Okay? +So you can sort of appreciate where the + + align:start position:0% +So you can sort of appreciate where the + + + align:start position:0% +So you can sort of appreciate where the +music industry is coming from because + + align:start position:0% +music industry is coming from because + + + align:start position:0% +music industry is coming from because +things have + + align:start position:0% +things have + + + align:start position:0% +things have +changed. Okay. So + + align:start position:0% +changed. Okay. So + + + align:start position:0% +changed. Okay. So +um distortions, expensive, fragile, blah + + align:start position:0% +um distortions, expensive, fragile, blah + + + align:start position:0% +um distortions, expensive, fragile, blah +blah blah. Then in the 1980s, everything + + align:start position:0% +blah blah. Then in the 1980s, everything + + + align:start position:0% +blah blah. Then in the 1980s, everything +changed. In the 1980s there was the + + align:start position:0% +changed. In the 1980s there was the + + + align:start position:0% +changed. In the 1980s there was the +invention of the CD. CD was invented by + + align:start position:0% +invention of the CD. CD was invented by + + + align:start position:0% +invention of the CD. CD was invented by +Philips Corp and Sony Corp working + + align:start position:0% +Philips Corp and Sony Corp working + + + align:start position:0% +Philips Corp and Sony Corp working +together and just everything was + + align:start position:0% +together and just everything was + + + align:start position:0% +together and just everything was +revolutionized. + + align:start position:0% +revolutionized. + + + align:start position:0% +revolutionized. +So + + align:start position:0% +So + + + align:start position:0% +So +um we'll talk a little bit about how + + align:start position:0% +um we'll talk a little bit about how + + + align:start position:0% +um we'll talk a little bit about how +this thing how the CD works. The + + align:start position:0% +this thing how the CD works. The + + + align:start position:0% +this thing how the CD works. The +important thing for the discussion is + + align:start position:0% +important thing for the discussion is + + + align:start position:0% +important thing for the discussion is +that unlike records, CDs are virtually + + align:start position:0% +that unlike records, CDs are virtually + + + align:start position:0% +that unlike records, CDs are virtually +indestructible. They have very low + + align:start position:0% +indestructible. They have very low + + + align:start position:0% +indestructible. They have very low +distortion. They're next to + + align:start position:0% +distortion. They're next to + + + align:start position:0% +distortion. They're next to +free and all of that is technology + + align:start position:0% +free and all of that is technology + + + align:start position:0% +free and all of that is technology +that's in large part enabled by 63 and + + align:start position:0% +that's in large part enabled by 63 and + + + align:start position:0% +that's in large part enabled by 63 and +that's what I want to actually talk + + align:start position:0% +that's what I want to actually talk + + + align:start position:0% +that's what I want to actually talk +about. So uh what is a CD? CD is not + + align:start position:0% +about. So uh what is a CD? CD is not + + + align:start position:0% +about. So uh what is a CD? CD is not +very different from a record. So a CD + + align:start position:0% +very different from a record. So a CD + + + align:start position:0% +very different from a record. So a CD +has tracks. The information is written + + align:start position:0% +has tracks. The information is written + + + align:start position:0% +has tracks. The information is written +in tracks. The tracks are written as a + + align:start position:0% +in tracks. The tracks are written as a + + + align:start position:0% +in tracks. The tracks are written as a +spiral. The spiral starts at the inside + + align:start position:0% +spiral. The spiral starts at the inside + + + align:start position:0% +spiral. The spiral starts at the inside +and spirals + + align:start position:0% +and spirals + + + align:start position:0% +and spirals +out. And so the idea is that you read a + + align:start position:0% +out. And so the idea is that you read a + + + align:start position:0% +out. And so the idea is that you read a +spiral of messages. And just like a + + align:start position:0% +spiral of messages. And just like a + + + align:start position:0% +spiral of messages. And just like a +record, the way you make a record is + + align:start position:0% +record, the way you make a record is + + + align:start position:0% +record, the way you make a record is +called embossing. You make a master and + + align:start position:0% +called embossing. You make a master and + + + align:start position:0% +called embossing. You make a master and +then you take um u molten + + align:start position:0% +then you take um u molten + + + align:start position:0% +then you take um u molten +plastic and uh press it and copy the + + align:start position:0% +plastic and uh press it and copy the + + + align:start position:0% +plastic and uh press it and copy the +patterns to make that record. Right? In + + align:start position:0% +patterns to make that record. Right? In + + + align:start position:0% +patterns to make that record. Right? In +fact, there was a big technology on the + + align:start position:0% +fact, there was a big technology on the + + + align:start position:0% +fact, there was a big technology on the +formula that you used for the vinyl. + + align:start position:0% +formula that you used for the vinyl. + + + align:start position:0% +formula that you used for the vinyl. +Right? One of the secrets of RCA at the + + align:start position:0% +Right? One of the secrets of RCA at the + + + align:start position:0% +Right? One of the secrets of RCA at the +time when I was in graduate school, when + + align:start position:0% +time when I was in graduate school, when + + + align:start position:0% +time when I was in graduate school, when +I was in graduate school, they had a + + align:start position:0% +I was in graduate school, they had a + + + align:start position:0% +I was in graduate school, they had a +secret recipe that included dropping + + align:start position:0% +secret recipe that included dropping + + + align:start position:0% +secret recipe that included dropping +four slices of American cheese in their + + align:start position:0% +four slices of American cheese in their + + + align:start position:0% +four slices of American cheese in their +vinyl producing because somebody had + + align:start position:0% +vinyl producing because somebody had + + + align:start position:0% +vinyl producing because somebody had +accidentally once dropped a sandwich and + + align:start position:0% +accidentally once dropped a sandwich and + + + align:start position:0% +accidentally once dropped a sandwich and +those records came out + + align:start position:0% +those records came out + + + align:start position:0% +those records came out +good. So, so there were there were + + align:start position:0% +good. So, so there were there were + + + align:start position:0% +good. So, so there were there were +magical things like that that were trade + + align:start position:0% +magical things like that that were trade + + + align:start position:0% +magical things like that that were trade +secrets at the time. Okay. said that so + + align:start position:0% +secrets at the time. Okay. said that so + + + align:start position:0% +secrets at the time. Okay. said that so +that technology was basically embossing + + align:start position:0% +that technology was basically embossing + + + align:start position:0% +that technology was basically embossing +and that's the same thing you do when + + align:start position:0% +and that's the same thing you do when + + + align:start position:0% +and that's the same thing you do when +you make a CD. CD is + + align:start position:0% +you make a CD. CD is + + + align:start position:0% +you make a CD. CD is +polycarbonate which is u injection + + align:start position:0% +polycarbonate which is u injection + + + align:start position:0% +polycarbonate which is u injection +molded. So um you make a master. The + + align:start position:0% +molded. So um you make a master. The + + + align:start position:0% +molded. So um you make a master. The +master is usually made out of aluminum. + + align:start position:0% +master is usually made out of aluminum. + + + align:start position:0% +master is usually made out of aluminum. +The master is made very similar to the + + align:start position:0% +The master is made very similar to the + + + align:start position:0% +The master is made very similar to the +way that Edison would make a master. + + align:start position:0% +way that Edison would make a master. + + + align:start position:0% +way that Edison would make a master. +There's a big device with an + + align:start position:0% +There's a big device with an + + + align:start position:0% +There's a big device with an +electromagnet with a small stylus and it + + align:start position:0% +electromagnet with a small stylus and it + + + align:start position:0% +electromagnet with a small stylus and it +punches them. + + align:start position:0% +punches them. + + + align:start position:0% +punches them. +But then you copy the CDs uh by + + align:start position:0% +But then you copy the CDs uh by + + + align:start position:0% +But then you copy the CDs uh by +injection molding. So you take that + + align:start position:0% +injection molding. So you take that + + + align:start position:0% +injection molding. So you take that +original and there's actually a + + align:start position:0% +original and there's actually a + + + align:start position:0% +original and there's actually a +complicated process. You use the + + align:start position:0% +complicated process. You use the + + + align:start position:0% +complicated process. You use the +original to make a a half a dozen + + align:start position:0% +original to make a a half a dozen + + + align:start position:0% +original to make a a half a dozen +fathers. The fathers are used to make + + align:start position:0% +fathers. The fathers are used to make + + + align:start position:0% +fathers. The fathers are used to make +mothers. Each father makes 20 mothers. + + align:start position:0% +mothers. Each father makes 20 mothers. + + + align:start position:0% +mothers. Each father makes 20 mothers. +Then each of the mothers make children. + + align:start position:0% +Then each of the mothers make children. + + + align:start position:0% +Then each of the mothers make children. +And so you end up being able to get a + + align:start position:0% +And so you end up being able to get a + + + align:start position:0% +And so you end up being able to get a +lot of copies out of the original + + align:start position:0% +lot of copies out of the original + + + align:start position:0% +lot of copies out of the original +master. The polycarbonate. And there's a + + align:start position:0% +master. The polycarbonate. And there's a + + + align:start position:0% +master. The polycarbonate. And there's a +reflective layer of aluminum that's + + align:start position:0% +reflective layer of aluminum that's + + + align:start position:0% +reflective layer of aluminum that's +evaporated on top of the polycarbonate. + + align:start position:0% +evaporated on top of the polycarbonate. + + + align:start position:0% +evaporated on top of the polycarbonate. +And then there's a thin layer of plastic + + align:start position:0% +And then there's a thin layer of plastic + + + align:start position:0% +And then there's a thin layer of plastic +put over the top. That results in + + align:start position:0% +put over the top. That results in + + + align:start position:0% +put over the top. That results in +something that's extremely um robust. + + align:start position:0% +something that's extremely um robust. + + + align:start position:0% +something that's extremely um robust. +So, and we'll see in a minute how they + + align:start position:0% +So, and we'll see in a minute how they + + + align:start position:0% +So, and we'll see in a minute how they +make it + + align:start position:0% +make it + + + align:start position:0% +make it +robust, but this dimension is like um + + align:start position:0% +robust, but this dimension is like um + + + align:start position:0% +robust, but this dimension is like um +over a millimeter. So when you So um so + + align:start position:0% +over a millimeter. So when you So um so + + + align:start position:0% +over a millimeter. So when you So um so +this is CD version of the same + + align:start position:0% +this is CD version of the same + + + align:start position:0% +this is CD version of the same +album. So this surface is the + + align:start position:0% +album. So this surface is the + + + align:start position:0% +album. So this surface is the +information reading side, right? There's + + align:start position:0% +information reading side, right? There's + + + align:start position:0% +information reading side, right? There's +a millimeter of stuff + + align:start position:0% +a millimeter of stuff + + + align:start position:0% +a millimeter of stuff +here. There's a millimeter of + + align:start position:0% +here. There's a millimeter of + + + align:start position:0% +here. There's a millimeter of +polycarbonate protecting the surface + + align:start position:0% +polycarbonate protecting the surface + + + align:start position:0% +polycarbonate protecting the surface +that has the information from the + + align:start position:0% +that has the information from the + + + align:start position:0% +that has the information from the +environment. So in fact, the way if you + + align:start position:0% +environment. So in fact, the way if you + + + align:start position:0% +environment. So in fact, the way if you +want to destroy somebody's CD, you might + + align:start position:0% +want to destroy somebody's CD, you might + + + align:start position:0% +want to destroy somebody's CD, you might +think the way to do that would be to + + align:start position:0% +think the way to do that would be to + + + align:start position:0% +think the way to do that would be to +write in felt tip on here. No, don't do + + align:start position:0% +write in felt tip on here. No, don't do + + + align:start position:0% +write in felt tip on here. No, don't do +it that way. Use a ballpoint pen on this + + align:start position:0% +it that way. Use a ballpoint pen on this + + + align:start position:0% +it that way. Use a ballpoint pen on this +side because that layer of plastic is + + align:start position:0% +side because that layer of plastic is + + + align:start position:0% +side because that layer of plastic is +very thin. So, use a ballpoint pen here. + + align:start position:0% +very thin. So, use a ballpoint pen here. + + + align:start position:0% +very thin. So, use a ballpoint pen here. +It'll completely screw it up. So, uh + + align:start position:0% +It'll completely screw it up. So, uh + + + align:start position:0% +It'll completely screw it up. So, uh +it's very robust when uh against + + align:start position:0% +it's very robust when uh against + + + align:start position:0% +it's very robust when uh against +imperfections on the read + + align:start position:0% +imperfections on the read + + + align:start position:0% +imperfections on the read +side. Okay. So, uh that's kind of the + + align:start position:0% +side. Okay. So, uh that's kind of the + + + align:start position:0% +side. Okay. So, uh that's kind of the +structure. It's virtually indestructible + + align:start position:0% +structure. It's virtually indestructible + + + align:start position:0% +structure. It's virtually indestructible +is the point. + + align:start position:0% +is the point. + + + align:start position:0% +is the point. +So then uh how do you get the + + align:start position:0% +So then uh how do you get the + + + align:start position:0% +So then uh how do you get the +information on it? Well, the information + + align:start position:0% +information on it? Well, the information + + + align:start position:0% +information on it? Well, the information +is coated in these patterns. The + + align:start position:0% +is coated in these patterns. The + + + align:start position:0% +is coated in these patterns. The +patterns are small. The the pattern + + align:start position:0% +patterns are small. The the pattern + + + align:start position:0% +patterns are small. The the pattern +width is half micron. A human hair is 50 + + align:start position:0% +width is half micron. A human hair is 50 + + + align:start position:0% +width is half micron. A human hair is 50 +to 100 microns + + align:start position:0% +to 100 microns + + + align:start position:0% +to 100 microns +thick. So if you and I have white hair, + + align:start position:0% +thick. So if you and I have white hair, + + + align:start position:0% +thick. So if you and I have white hair, +well I used to have blonde hair. I have + + align:start position:0% +well I used to have blonde hair. I have + + + align:start position:0% +well I used to have blonde hair. I have +gray hair now. Ignoring that for the + + align:start position:0% +gray hair now. Ignoring that for the + + + align:start position:0% +gray hair now. Ignoring that for the +moment. Uh I used to have blonde hair. + + align:start position:0% +moment. Uh I used to have blonde hair. + + + align:start position:0% +moment. Uh I used to have blonde hair. +Blonde hair is about 50 microns um + + align:start position:0% +Blonde hair is about 50 microns um + + + align:start position:0% +Blonde hair is about 50 microns um +diameter. Black hair is about 100 + + align:start position:0% +diameter. Black hair is about 100 + + + align:start position:0% +diameter. Black hair is about 100 +microns diameter. So depending on the + + align:start position:0% +microns diameter. So depending on the + + + align:start position:0% +microns diameter. So depending on the +color of your hair, it would obscure so + + align:start position:0% +color of your hair, it would obscure so + + + align:start position:0% +color of your hair, it would obscure so +30 to 60 tracks if you were to lay a + + align:start position:0% +30 to 60 tracks if you were to lay a + + + align:start position:0% +30 to 60 tracks if you were to lay a +hair across it. So these are very very + + align:start position:0% +hair across it. So these are very very + + + align:start position:0% +hair across it. So these are very very +small + + align:start position:0% +small + + + align:start position:0% +small +patterns. And so the trick + + align:start position:0% +patterns. And so the trick + + + align:start position:0% +patterns. And so the trick +uh for uh uh how you code them is a big + + align:start position:0% +uh for uh uh how you code them is a big + + + align:start position:0% +uh for uh uh how you code them is a big +problem. Before we get there though, the + + align:start position:0% +problem. Before we get there though, the + + + align:start position:0% +problem. Before we get there though, the +how do you code the audio? You won't be + + align:start position:0% +how do you code the audio? You won't be + + + align:start position:0% +how do you code the audio? You won't be +too surprised to find out that it's a + + align:start position:0% +too surprised to find out that it's a + + + align:start position:0% +too surprised to find out that it's a +sample data system. So we do sampling + + align:start position:0% +sample data system. So we do sampling + + + align:start position:0% +sample data system. So we do sampling +just the way we've talked about it + + align:start position:0% +just the way we've talked about it + + + align:start position:0% +just the way we've talked about it +before. Audio, you can hear sounds from + + align:start position:0% +before. Audio, you can hear sounds from + + + align:start position:0% +before. Audio, you can hear sounds from +about 20 hertz to about 20 kHz. This is + + align:start position:0% +about 20 hertz to about 20 kHz. This is + + + align:start position:0% +about 20 hertz to about 20 kHz. This is +an audiogram. Aiograms plot as a + + align:start position:0% +an audiogram. Aiograms plot as a + + + align:start position:0% +an audiogram. Aiograms plot as a +function of frequency. What's the + + align:start position:0% +function of frequency. What's the + + + align:start position:0% +function of frequency. What's the +minimum amplitude required to be able to + + align:start position:0% +minimum amplitude required to be able to + + + align:start position:0% +minimum amplitude required to be able to +hear that frequency? You're most + + align:start position:0% +hear that frequency? You're most + + + align:start position:0% +hear that frequency? You're most +sensitive in the kilhertz + + align:start position:0% +sensitive in the kilhertz + + + align:start position:0% +sensitive in the kilhertz +region. Uh the scale over here is db in + + align:start position:0% +region. Uh the scale over here is db in + + + align:start position:0% +region. Uh the scale over here is db in +something we call sound pressure level. + + align:start position:0% +something we call sound pressure level. + + + align:start position:0% +something we call sound pressure level. +Sound pressure level is the centigrade + + align:start position:0% +Sound pressure level is the centigrade + + + align:start position:0% +Sound pressure level is the centigrade +equivalent for hearing. So zero is just + + align:start position:0% +equivalent for hearing. So zero is just + + + align:start position:0% +equivalent for hearing. So zero is just +audible, 100 is starts to hurt, 120 is + + align:start position:0% +audible, 100 is starts to hurt, 120 is + + + align:start position:0% +audible, 100 is starts to hurt, 120 is +uh permanent damage kind of thing. So + + align:start position:0% +uh permanent damage kind of thing. So + + + align:start position:0% +uh permanent damage kind of thing. So +you can hear about u 100 + + align:start position:0% +you can hear about u 100 + + + align:start position:0% +you can hear about u 100 +dB over a range from 20 to 20 + + align:start position:0% +dB over a range from 20 to 20 + + + align:start position:0% +dB over a range from 20 to 20 +kHz. And so the way they coded it for + + align:start position:0% +kHz. And so the way they coded it for + + + align:start position:0% +kHz. And so the way they coded it for +the CD was uh sampled at 44.1 kHz. They + + align:start position:0% +the CD was uh sampled at 44.1 kHz. They + + + align:start position:0% +the CD was uh sampled at 44.1 kHz. They +chose that funny + + align:start position:0% +chose that funny + + + align:start position:0% +chose that funny +number to be a little bit bigger than + + align:start position:0% +number to be a little bit bigger than + + + align:start position:0% +number to be a little bit bigger than +twice the highest frequency that you can + + align:start position:0% +twice the highest frequency that you can + + + align:start position:0% +twice the highest frequency that you can +hear, but they made it the funny number + + align:start position:0% +hear, but they made it the funny number + + + align:start position:0% +hear, but they made it the funny number +because they wanted it to be an integer + + align:start position:0% +because they wanted it to be an integer + + + align:start position:0% +because they wanted it to be an integer +multip integer multiple of 60. So it was + + align:start position:0% +multip integer multiple of 60. So it was + + + align:start position:0% +multip integer multiple of 60. So it was +easy to synchronize with television + + align:start position:0% +easy to synchronize with television + + + align:start position:0% +easy to synchronize with television +signals. That's where the funny number + + align:start position:0% +signals. That's where the funny number + + + align:start position:0% +signals. That's where the funny number +came from. So 44.1 kHz divided by 60 is + + align:start position:0% +came from. So 44.1 kHz divided by 60 is + + + align:start position:0% +came from. So 44.1 kHz divided by 60 is +some integer. + + align:start position:0% +some integer. + + + align:start position:0% +some integer. +The problem is of course that they + + align:start position:0% +The problem is of course that they + + + align:start position:0% +The problem is of course that they +wanted to be greedy. They wanted all the + + align:start position:0% +wanted to be greedy. They wanted all the + + + align:start position:0% +wanted to be greedy. They wanted all the +bits to code + + align:start position:0% +bits to code + + + align:start position:0% +bits to code +audio. So they only sampled barely over + + align:start position:0% +audio. So they only sampled barely over + + + align:start position:0% +audio. So they only sampled barely over +the frequency that was required. Right? + + align:start position:0% +the frequency that was required. Right? + + + align:start position:0% +the frequency that was required. Right? +So you would according to the sampling + + align:start position:0% +So you would according to the sampling + + + align:start position:0% +So you would according to the sampling +theorem you need + + align:start position:0% +theorem you need + + + align:start position:0% +theorem you need +40 if you get any information that's not + + align:start position:0% +40 if you get any information that's not + + + align:start position:0% +40 if you get any information that's not +that. So if you had um a sample data + + align:start position:0% +that. So if you had um a sample data + + + align:start position:0% +that. So if you had um a sample data +system running at 44, any amount of + + align:start position:0% +system running at 44, any amount of + + + align:start position:0% +system running at 44, any amount of +signal above + + align:start position:0% +signal above + + + align:start position:0% +signal above +22 would alias and sound + + align:start position:0% +22 would alias and sound + + + align:start position:0% +22 would alias and sound +terrible. So you need to put an + + align:start position:0% +terrible. So you need to put an + + + align:start position:0% +terrible. So you need to put an +anti-aliasing filter to prevent + + align:start position:0% +anti-aliasing filter to prevent + + + align:start position:0% +anti-aliasing filter to prevent +that. Uh we've kind of cheated the whole + + align:start position:0% +that. Uh we've kind of cheated the whole + + + align:start position:0% +that. Uh we've kind of cheated the whole +way through. We always said when you + + align:start position:0% +way through. We always said when you + + + align:start position:0% +way through. We always said when you +need a low pass filter, use an ideal + + align:start position:0% +need a low pass filter, use an ideal + + + align:start position:0% +need a low pass filter, use an ideal +one. Well, they don't exist, right? Uh + + align:start position:0% +one. Well, they don't exist, right? Uh + + + align:start position:0% +one. Well, they don't exist, right? Uh +we use ideal filters because they're + + align:start position:0% +we use ideal filters because they're + + + align:start position:0% +we use ideal filters because they're +conceptually simple. There is no such + + align:start position:0% +conceptually simple. There is no such + + + align:start position:0% +conceptually simple. There is no such +thing. If you actually try to make a a + + align:start position:0% +thing. If you actually try to make a a + + + align:start position:0% +thing. If you actually try to make a a +filter using designs like Russ talked + + align:start position:0% +filter using designs like Russ talked + + + align:start position:0% +filter using designs like Russ talked +about in recitation, butterworth + + align:start position:0% +about in recitation, butterworth + + + align:start position:0% +about in recitation, butterworth +filters, things like that, they have + + align:start position:0% +filters, things like that, they have + + + align:start position:0% +filters, things like that, they have +transition bandwidths. So there's a + + align:start position:0% +transition bandwidths. So there's a + + + align:start position:0% +transition bandwidths. So there's a +range of frequencies for which the + + align:start position:0% +range of frequencies for which the + + + align:start position:0% +range of frequencies for which the +filter is neither fully on nor fully off + + align:start position:0% +filter is neither fully on nor fully off + + + align:start position:0% +filter is neither fully on nor fully off +and it's in + + align:start position:0% +and it's in + + + align:start position:0% +and it's in +transition. Uh you would like that range + + align:start position:0% +transition. Uh you would like that range + + + align:start position:0% +transition. Uh you would like that range +of frequencies to be very small so you + + align:start position:0% +of frequencies to be very small so you + + + align:start position:0% +of frequencies to be very small so you +don't waste + + align:start position:0% +don't waste + + + align:start position:0% +don't waste +bandwidth. they allocated. So, so they + + align:start position:0% +bandwidth. they allocated. So, so they + + + align:start position:0% +bandwidth. they allocated. So, so they +would like to reconstruct up to 40 and + + align:start position:0% +would like to reconstruct up to 40 and + + + align:start position:0% +would like to reconstruct up to 40 and +they only allowed four kilhertz in the + + align:start position:0% +they only allowed four kilhertz in the + + + align:start position:0% +they only allowed four kilhertz in the +guard band, right? That was intentional + + align:start position:0% +guard band, right? That was intentional + + + align:start position:0% +guard band, right? That was intentional +because they didn't want to have a lot + + align:start position:0% +because they didn't want to have a lot + + + align:start position:0% +because they didn't want to have a lot +of bits that were not useful for + + align:start position:0% +of bits that were not useful for + + + align:start position:0% +of bits that were not useful for +recording audio. That's the reason they + + align:start position:0% +recording audio. That's the reason they + + + align:start position:0% +recording audio. That's the reason they +only went up to 44 instead of say 80, + + align:start position:0% +only went up to 44 instead of say 80, + + + align:start position:0% +only went up to 44 instead of say 80, +which would have made the anti-aliasing + + align:start position:0% +which would have made the anti-aliasing + + + align:start position:0% +which would have made the anti-aliasing +problem + + align:start position:0% +problem + + + align:start position:0% +problem +simple, but it complicated the the + + align:start position:0% +simple, but it complicated the the + + + align:start position:0% +simple, but it complicated the the +making of the anti-alias filter, right? + + align:start position:0% +making of the anti-alias filter, right? + + + align:start position:0% +making of the anti-alias filter, right? +because there is sounds that come into + + align:start position:0% +because there is sounds that come into + + + align:start position:0% +because there is sounds that come into +microphones above 20 kHz. It's just that + + align:start position:0% +microphones above 20 kHz. It's just that + + + align:start position:0% +microphones above 20 kHz. It's just that +you can't hear + + align:start position:0% +you can't hear + + + align:start position:0% +you can't hear +them. But if you were to record those + + align:start position:0% +them. But if you were to record those + + + align:start position:0% +them. But if you were to record those +sounds and then sample them at at um 40 + + align:start position:0% +sounds and then sample them at at um 40 + + + align:start position:0% +sounds and then sample them at at um 40 +kHz, you would hear the alias and it + + align:start position:0% +kHz, you would hear the alias and it + + + align:start position:0% +kHz, you would hear the alias and it +would be highly objectionable. So you + + align:start position:0% +would be highly objectionable. So you + + + align:start position:0% +would be highly objectionable. So you +have to + + align:start position:0% +have to + + + align:start position:0% +have to +anti-alias. And that's actually hard + + align:start position:0% +anti-alias. And that's actually hard + + + align:start position:0% +anti-alias. And that's actually hard +because if you'd like to hear up to + + align:start position:0% +because if you'd like to hear up to + + + align:start position:0% +because if you'd like to hear up to +20 and if you're sampling at + + align:start position:0% +20 and if you're sampling at + + + align:start position:0% +20 and if you're sampling at +44.1 20 + + align:start position:0% +44.1 20 + + + align:start position:0% +44.1 20 +uh reflects down to + + align:start position:0% +uh reflects down to + + + align:start position:0% +uh reflects down to +24.1 which means that you you want the + + align:start position:0% +24.1 which means that you you want the + + + align:start position:0% +24.1 which means that you you want the +transition band to be u only 4 + + align:start position:0% +transition band to be u only 4 + + + align:start position:0% +transition band to be u only 4 +kHz. Okay. + + align:start position:0% +kHz. Okay. + + + align:start position:0% +kHz. Okay. +And if you think about the design of a + + align:start position:0% +And if you think about the design of a + + + align:start position:0% +And if you think about the design of a +filter like a Butterworth + + align:start position:0% +filter like a Butterworth + + + align:start position:0% +filter like a Butterworth +filter, in order to get a transition + + align:start position:0% +filter, in order to get a transition + + + align:start position:0% +filter, in order to get a transition +that attenuates by 80 + + align:start position:0% +that attenuates by 80 + + + align:start position:0% +that attenuates by 80 +dB, think about the dynamic range of + + align:start position:0% +dB, think about the dynamic range of + + + align:start position:0% +dB, think about the dynamic range of +hearing, you have to make the loudest + + align:start position:0% +hearing, you have to make the loudest + + + align:start position:0% +hearing, you have to make the loudest +sounds small enough so that you can no + + align:start position:0% +sounds small enough so that you can no + + + align:start position:0% +sounds small enough so that you can no +longer hear them. So in general, you + + align:start position:0% +longer hear them. So in general, you + + + align:start position:0% +longer hear them. So in general, you +have to attenuate by about 80 + + align:start position:0% +have to attenuate by about 80 + + + align:start position:0% +have to attenuate by about 80 +dB. Um, you need about 50 poles to get + + align:start position:0% +dB. Um, you need about 50 poles to get + + + align:start position:0% +dB. Um, you need about 50 poles to get +an add attenuation. + + align:start position:0% +an add attenuation. + + + align:start position:0% +an add attenuation. +uh using a Butterworth design in 4 kHz + + align:start position:0% +uh using a Butterworth design in 4 kHz + + + align:start position:0% +uh using a Butterworth design in 4 kHz +at 20 kHz. Everybody sort of know what + + align:start position:0% +at 20 kHz. Everybody sort of know what + + + align:start position:0% +at 20 kHz. Everybody sort of know what +I'm talking + + align:start position:0% +I'm talking + + + align:start position:0% +I'm talking +about. That's + + align:start position:0% +about. That's + + + align:start position:0% +about. That's +impossible. Uh lining up filters there. + + align:start position:0% +impossible. Uh lining up filters there. + + + align:start position:0% +impossible. Uh lining up filters there. +So the way the Butterworth filters work, + + align:start position:0% +So the way the Butterworth filters work, + + + align:start position:0% +So the way the Butterworth filters work, +you remember? So you have + + align:start position:0% +you remember? So you have + + + align:start position:0% +you remember? So you have +um you have a bunch of + + align:start position:0% +um you have a bunch of + + + align:start position:0% +um you have a bunch of +poles like + + align:start position:0% +poles like + + + align:start position:0% +poles like +so. The way you think about that is that + + align:start position:0% +so. The way you think about that is that + + + align:start position:0% +so. The way you think about that is that +you start with a design that looks like + + align:start position:0% +you start with a design that looks like + + + align:start position:0% +you start with a design that looks like +a not so good low pass + + align:start position:0% +a not so good low pass + + + align:start position:0% +a not so good low pass +filter. Then you add these + + align:start position:0% +filter. Then you add these + + + align:start position:0% +filter. Then you add these +poles which give you a peaky + + align:start position:0% +poles which give you a peaky + + + align:start position:0% +poles which give you a peaky +response like that. So that when this is + + align:start position:0% +response like that. So that when this is + + + align:start position:0% +response like that. So that when this is +going down the peakiness here helps to + + align:start position:0% +going down the peakiness here helps to + + + align:start position:0% +going down the peakiness here helps to +cancel + + align:start position:0% +cancel + + + align:start position:0% +cancel +that. Then you do that + + align:start position:0% +that. Then you do that + + + align:start position:0% +that. Then you do that +again. So you do you can think about + + align:start position:0% +again. So you do you can think about + + + align:start position:0% +again. So you do you can think about +these uh successive pole pairs as + + align:start position:0% +these uh successive pole pairs as + + + align:start position:0% +these uh successive pole pairs as +sharpening the transition by pushing + + align:start position:0% +sharpening the transition by pushing + + + align:start position:0% +sharpening the transition by pushing +up on the center frequency and rolling + + align:start position:0% +up on the center frequency and rolling + + + align:start position:0% +up on the center frequency and rolling +off on the edge frequency. But in order + + align:start position:0% +off on the edge frequency. But in order + + + align:start position:0% +off on the edge frequency. But in order +for that to work, they have to all be + + align:start position:0% +for that to work, they have to all be + + + align:start position:0% +for that to work, they have to all be +lined up. So if you've got 50 of them, + + align:start position:0% +lined up. So if you've got 50 of them, + + + align:start position:0% +lined up. So if you've got 50 of them, +you've got to be able to line these up + + align:start position:0% +you've got to be able to line these up + + + align:start position:0% +you've got to be able to line these up +to about a percent or so. Otherwise, + + align:start position:0% +to about a percent or so. Otherwise, + + + align:start position:0% +to about a percent or so. Otherwise, +they don't perform the way they're + + align:start position:0% +they don't perform the way they're + + + align:start position:0% +they don't perform the way they're +supposed to, and they can actually make + + align:start position:0% +supposed to, and they can actually make + + + align:start position:0% +supposed to, and they can actually make +things worse. + + align:start position:0% +things worse. + + + align:start position:0% +things worse. +So making uh an analog filter of that + + align:start position:0% +So making uh an analog filter of that + + + align:start position:0% +So making uh an analog filter of that +type + + align:start position:0% +type + + + align:start position:0% +type +uh was impossible then and is difficult + + align:start position:0% +uh was impossible then and is difficult + + + align:start position:0% +uh was impossible then and is difficult +now. Here's sort of the + + align:start position:0% +now. Here's sort of the + + + align:start position:0% +now. Here's sort of the +state-of-the-art. So this is uh this + + align:start position:0% +state-of-the-art. So this is uh this + + + align:start position:0% +state-of-the-art. So this is uh this +actually does have 80 dB of rolloff + + align:start position:0% +actually does have 80 dB of rolloff + + + align:start position:0% +actually does have 80 dB of rolloff +because it's a fancier design. It's an + + align:start position:0% +because it's a fancier design. It's an + + + align:start position:0% +because it's a fancier design. It's an +elliptic design. The trick here though + + align:start position:0% +elliptic design. The trick here though + + + align:start position:0% +elliptic design. The trick here though +is that all the parts are laser trimmed. + + align:start position:0% +is that all the parts are laser trimmed. + + + align:start position:0% +is that all the parts are laser trimmed. +So they're all done on one substrate. + + align:start position:0% +So they're all done on one substrate. + + + align:start position:0% +So they're all done on one substrate. +All the inductors, all the capacitors + + align:start position:0% +All the inductors, all the capacitors + + + align:start position:0% +All the inductors, all the capacitors +are done on a single substrate. Then + + align:start position:0% +are done on a single substrate. Then + + + align:start position:0% +are done on a single substrate. Then +they're laser trimmed so that they fall + + align:start position:0% +they're laser trimmed so that they fall + + + align:start position:0% +they're laser trimmed so that they fall +in exactly the right + + align:start position:0% +in exactly the right + + + align:start position:0% +in exactly the right +places. Then it's u encased in aluminum + + align:start position:0% +places. Then it's u encased in aluminum + + + align:start position:0% +places. Then it's u encased in aluminum +to help to hold the uh temperature + + align:start position:0% +to help to hold the uh temperature + + + align:start position:0% +to help to hold the uh temperature +constant and to keep the electromagnetic + + align:start position:0% +constant and to keep the electromagnetic + + + align:start position:0% +constant and to keep the electromagnetic +inter interference + + align:start position:0% +inter interference + + + align:start position:0% +inter interference +out. And even so this has just 11 pole + + align:start position:0% +out. And even so this has just 11 pole + + + align:start position:0% +out. And even so this has just 11 pole +pairs. So this is not nearly adequate + + align:start position:0% +pairs. So this is not nearly adequate + + + align:start position:0% +pairs. So this is not nearly adequate +for that kind of a design. + + align:start position:0% +for that kind of a design. + + + align:start position:0% +for that kind of a design. +So what we do instead + + align:start position:0% +So what we do instead + + + align:start position:0% +So what we do instead +uh is we do something called uh + + align:start position:0% +uh is we do something called uh + + + align:start position:0% +uh is we do something called uh +oversampling. So instead of sampling at + + align:start position:0% +oversampling. So instead of sampling at + + + align:start position:0% +oversampling. So instead of sampling at +44.1 which is what you would think would + + align:start position:0% +44.1 which is what you would think would + + + align:start position:0% +44.1 which is what you would think would +happen in a CD, you sample at four times + + align:start position:0% +happen in a CD, you sample at four times + + + align:start position:0% +happen in a CD, you sample at four times +that. By sampling at a very high + + align:start position:0% +that. By sampling at a very high + + + align:start position:0% +that. By sampling at a very high +frequency, you make it easy to make an + + align:start position:0% +frequency, you make it easy to make an + + + align:start position:0% +frequency, you make it easy to make an +anti-aliasing + + align:start position:0% +anti-aliasing + + + align:start position:0% +anti-aliasing +filter because now you only need to + + align:start position:0% +filter because now you only need to + + + align:start position:0% +filter because now you only need to +worry about saving the frequencies up to + + align:start position:0% +worry about saving the frequencies up to + + + align:start position:0% +worry about saving the frequencies up to + + align:start position:0% + + + align:start position:0% +kHz, but you've got 170 kHz to drop the + + align:start position:0% +kHz, but you've got 170 kHz to drop the + + + align:start position:0% +kHz, but you've got 170 kHz to drop the +uh transition to do the transition. So + + align:start position:0% +uh transition to do the transition. So + + + align:start position:0% +uh transition to do the transition. So +the filter design becomes very easy. In + + align:start position:0% +the filter design becomes very easy. In + + + align:start position:0% +the filter design becomes very easy. In +fact, a typical design only has five + + align:start position:0% +fact, a typical design only has five + + + align:start position:0% +fact, a typical design only has five +poles. So just a handful of capacitor + + align:start position:0% +poles. So just a handful of capacitor + + + align:start position:0% +poles. So just a handful of capacitor +just uh two capacitors uh uh and two op + + align:start position:0% +just uh two capacitors uh uh and two op + + + align:start position:0% +just uh two capacitors uh uh and two op +amps will do + + align:start position:0% +amps will do + + + align:start position:0% +amps will do +that. So then you've got a system that + + align:start position:0% +that. So then you've got a system that + + + align:start position:0% +that. So then you've got a system that +uh is sampled at 176 kHz. What's the + + align:start position:0% +uh is sampled at 176 kHz. What's the + + + align:start position:0% +uh is sampled at 176 kHz. What's the +problem with + + align:start position:0% + + + + align:start position:0% + +that? What's the problem with sampling + + align:start position:0% +that? What's the problem with sampling + + + align:start position:0% +that? What's the problem with sampling +at 176 kHz? + + align:start position:0% + + + + align:start position:0% + +too much information. So what you've + + align:start position:0% +too much information. So what you've + + + align:start position:0% +too much information. So what you've +done by sampling at the higher frequency + + align:start position:0% +done by sampling at the higher frequency + + + align:start position:0% +done by sampling at the higher frequency +is you've increased the amount of + + align:start position:0% +is you've increased the amount of + + + align:start position:0% +is you've increased the amount of +information that needs to be stored by a + + align:start position:0% +information that needs to be stored by a + + + align:start position:0% +information that needs to be stored by a +factor of four. So instead of being able + + align:start position:0% +factor of four. So instead of being able + + + align:start position:0% +factor of four. So instead of being able +to record 74 minutes of + + align:start position:0% +to record 74 minutes of + + + align:start position:0% +to record 74 minutes of +music, you can record 74 divided by + + align:start position:0% +music, you can record 74 divided by + + + align:start position:0% +music, you can record 74 divided by +four, 18 minutes of music. Nobody would + + align:start position:0% +four, 18 minutes of music. Nobody would + + + align:start position:0% +four, 18 minutes of music. Nobody would +like that, right? So how do you fix + + align:start position:0% + + + + align:start position:0% + +that? Down sample. + + align:start position:0% +that? Down sample. + + + align:start position:0% +that? Down sample. +Exactly. So what you do is you run that + + align:start position:0% +Exactly. So what you do is you run that + + + align:start position:0% +Exactly. So what you do is you run that +176 this that uh discrete time signal + + align:start position:0% +176 this that uh discrete time signal + + + align:start position:0% +176 this that uh discrete time signal +that was sampled at 176 through a + + align:start position:0% +that was sampled at 176 through a + + + align:start position:0% +that was sampled at 176 through a +discrete lowass + + align:start position:0% +discrete lowass + + + align:start position:0% +discrete lowass +filter which you implement digitally + + align:start position:0% +filter which you implement digitally + + + align:start position:0% +filter which you implement digitally +with arbitrary precision as much as you + + align:start position:0% +with arbitrary precision as much as you + + + align:start position:0% +with arbitrary precision as much as you +want. So here's a design uh based + + align:start position:0% +want. So here's a design uh based + + + align:start position:0% +want. So here's a design uh based +on uh a filter whose length is 200 + + align:start position:0% +on uh a filter whose length is 200 + + + align:start position:0% +on uh a filter whose length is 200 +By making a length 200 discrete time + + align:start position:0% +By making a length 200 discrete time + + + align:start position:0% +By making a length 200 discrete time +filter, you can capture the basic sin t + + align:start position:0% +filter, you can capture the basic sin t + + + align:start position:0% +filter, you can capture the basic sin t +over t shape that you're trying to get + + align:start position:0% +over t shape that you're trying to get + + + align:start position:0% +over t shape that you're trying to get +with an ideal + + align:start position:0% +with an ideal + + + align:start position:0% +with an ideal +filter. You can you so here uh with 200 + + align:start position:0% +filter. You can you so here uh with 200 + + + align:start position:0% +filter. You can you so here uh with 200 +samples, it's easy to reproduce + + align:start position:0% +samples, it's easy to reproduce + + + align:start position:0% +samples, it's easy to reproduce +uh a large number of ripples similar to + + align:start position:0% +uh a large number of ripples similar to + + + align:start position:0% +uh a large number of ripples similar to +the large number of ripples that I + + align:start position:0% +the large number of ripples that I + + + align:start position:0% +the large number of ripples that I +wanted over here, but now with digital + + align:start position:0% +wanted over here, but now with digital + + + align:start position:0% +wanted over here, but now with digital +multiplies, not with uh resistors and + + align:start position:0% +multiplies, not with uh resistors and + + + align:start position:0% +multiplies, not with uh resistors and +capacitors. + + align:start position:0% +capacitors. + + + align:start position:0% +capacitors. +And the um this shows where the poles + + align:start position:0% +And the um this shows where the poles + + + align:start position:0% +And the um this shows where the poles +this is an all zero filter. It's a + + align:start position:0% +this is an all zero filter. It's a + + + align:start position:0% +this is an all zero filter. It's a +finite length filter. We didn't talk + + align:start position:0% +finite length filter. We didn't talk + + + align:start position:0% +finite length filter. We didn't talk +about that. It's an easy way to + + align:start position:0% +about that. It's an easy way to + + + align:start position:0% +about that. It's an easy way to +implement uh filter design. It's an easy + + align:start position:0% +implement uh filter design. It's an easy + + + align:start position:0% +implement uh filter design. It's an easy +way to design filters. Uh it's very + + align:start position:0% +way to design filters. Uh it's very + + + align:start position:0% +way to design filters. Uh it's very +popular way of doing it. So it's an all + + align:start position:0% +popular way of doing it. So it's an all + + + align:start position:0% +popular way of doing it. So it's an all +zero filter and you can sort of figure + + align:start position:0% +zero filter and you can sort of figure + + + align:start position:0% +zero filter and you can sort of figure +out by thinking about the spacing of the + + align:start position:0% +out by thinking about the spacing of the + + + align:start position:0% +out by thinking about the spacing of the +zeros relative to the unit circle how + + align:start position:0% +zeros relative to the unit circle how + + + align:start position:0% +zeros relative to the unit circle how +that implements a low pass filter. That + + align:start position:0% +that implements a low pass filter. That + + + align:start position:0% +that implements a low pass filter. That +was done with an automated u optimizing + + align:start position:0% +was done with an automated u optimizing + + + align:start position:0% +was done with an automated u optimizing +algorithm for finding the best low pass + + align:start position:0% +algorithm for finding the best low pass + + + align:start position:0% +algorithm for finding the best low pass +filter. The method is called the + + align:start position:0% +filter. The method is called the + + + align:start position:0% +filter. The method is called the +parksman + + align:start position:0% +parksman + + + align:start position:0% +parksman +algorithm and it makes a very nice + + align:start position:0% +algorithm and it makes a very nice + + + align:start position:0% +algorithm and it makes a very nice +filter. So this shows a transition of um + + align:start position:0% +filter. So this shows a transition of um + + + align:start position:0% +filter. So this shows a transition of um +uh + + align:start position:0% +uh + + + align:start position:0% +uh +80dB passing 20 kHz signals and + + align:start position:0% +80dB passing 20 kHz signals and + + + align:start position:0% +80dB passing 20 kHz signals and +attenuating uh 24 and above. So you can + + align:start position:0% +attenuating uh 24 and above. So you can + + + align:start position:0% +attenuating uh 24 and above. So you can +get a very nice filter by doing that in + + align:start position:0% +get a very nice filter by doing that in + + + align:start position:0% +get a very nice filter by doing that in +discrete time. + + align:start position:0% +discrete time. + + + align:start position:0% +discrete time. +So then uh having done the digital + + align:start position:0% +So then uh having done the digital + + + align:start position:0% +So then uh having done the digital +filter you can throw away the + + align:start position:0% +filter you can throw away the + + + align:start position:0% +filter you can throw away the +frequencies that would alias and then + + align:start position:0% +frequencies that would alias and then + + + align:start position:0% +frequencies that would alias and then +down sample. + + align:start position:0% +down sample. + + + align:start position:0% +down sample. +Yeah. Is the filter in those zero + + align:start position:0% +Yeah. Is the filter in those zero + + + align:start position:0% +Yeah. Is the filter in those zero +locations standardized by anybody or is + + align:start position:0% +locations standardized by anybody or is + + + align:start position:0% +locations standardized by anybody or is +any manufacturer any manufacturer? Yeah. + + align:start position:0% +any manufacturer any manufacturer? Yeah. + + + align:start position:0% +any manufacturer any manufacturer? Yeah. +Every manufacturer is different. What's + + align:start position:0% +Every manufacturer is different. What's + + + align:start position:0% +Every manufacturer is different. What's +happening over time though is that the + + align:start position:0% +happening over time though is that the + + + align:start position:0% +happening over time though is that the +chips are becoming standardized. So if + + align:start position:0% +chips are becoming standardized. So if + + + align:start position:0% +chips are becoming standardized. So if +you buy a particular chip, it has a + + align:start position:0% +you buy a particular chip, it has a + + + align:start position:0% +you buy a particular chip, it has a +particular filter set but it's not + + align:start position:0% +particular filter set but it's not + + + align:start position:0% +particular filter set but it's not +standardized in the code. + + align:start position:0% + + + + align:start position:0% + +Okay, so that's um uh how you generate a + + align:start position:0% +Okay, so that's um uh how you generate a + + + align:start position:0% +Okay, so that's um uh how you generate a +signal that is robust and it's basically + + align:start position:0% +signal that is robust and it's basically + + + align:start position:0% +signal that is robust and it's basically +just 03. Now we have to think about how + + align:start position:0% +just 03. Now we have to think about how + + + align:start position:0% +just 03. Now we have to think about how +would you make the + + align:start position:0% +would you make the + + + align:start position:0% +would you make the +player because what we'd like to do is + + align:start position:0% +player because what we'd like to do is + + + align:start position:0% +player because what we'd like to do is +enable you to + + align:start position:0% + + + + align:start position:0% + +um use a CD in a more portable fashion + + align:start position:0% +um use a CD in a more portable fashion + + + align:start position:0% +um use a CD in a more portable fashion +than you could use this technology. + + align:start position:0% +than you could use this technology. + + + align:start position:0% +than you could use this technology. +Right? So the question is now, how would + + align:start position:0% +Right? So the question is now, how would + + + align:start position:0% +Right? So the question is now, how would +you make a player that can pick up this + + align:start position:0% +you make a player that can pick up this + + + align:start position:0% +you make a player that can pick up this +information off of the + + align:start position:0% +information off of the + + + align:start position:0% +information off of the +CD so that you can reproduce it in a + + align:start position:0% +CD so that you can reproduce it in a + + + align:start position:0% +CD so that you can reproduce it in a +Walkman or in a in a more portable + + align:start position:0% +Walkman or in a in a more portable + + + align:start position:0% +Walkman or in a in a more portable +environment. So I had this brilliant + + align:start position:0% +environment. So I had this brilliant + + + align:start position:0% +environment. So I had this brilliant +idea about two years ago that I would + + align:start position:0% +idea about two years ago that I would + + + align:start position:0% +idea about two years ago that I would +take this + + align:start position:0% +take this + + + align:start position:0% +take this +CD and I would use my microscope. Okay, + + align:start position:0% +CD and I would use my microscope. Okay, + + + align:start position:0% +CD and I would use my microscope. Okay, +I may have mentioned I like microscopy. + + align:start position:0% +I may have mentioned I like microscopy. + + + align:start position:0% +I may have mentioned I like microscopy. +I went into my microscope. I used my + + align:start position:0% +I went into my microscope. I used my + + + align:start position:0% +I went into my microscope. I used my +research quality microscope which cost + + align:start position:0% +research quality microscope which cost + + + align:start position:0% +research quality microscope which cost +$70,000. And I'll take a beautiful + + align:start position:0% +$70,000. And I'll take a beautiful + + + align:start position:0% +$70,000. And I'll take a beautiful +picture of the bits on here and I'll + + align:start position:0% +picture of the bits on here and I'll + + + align:start position:0% +picture of the bits on here and I'll +write a problem set for 003 where you + + align:start position:0% +write a problem set for 003 where you + + + align:start position:0% +write a problem set for 003 where you +have to decode the the bitstream. Okay. + + align:start position:0% +have to decode the the bitstream. Okay. + + + align:start position:0% +have to decode the the bitstream. Okay. +I thought it was brilliant. Uh and you + + align:start position:0% +I thought it was brilliant. Uh and you + + + align:start position:0% +I thought it was brilliant. Uh and you +know it was like a week before the + + align:start position:0% +know it was like a week before the + + + align:start position:0% +know it was like a week before the +homework had to be written. You know the + + align:start position:0% +homework had to be written. You know the + + + align:start position:0% +homework had to be written. You know the +standard thing. And of course I couldn't + + align:start position:0% +standard thing. And of course I couldn't + + + align:start position:0% +standard thing. And of course I couldn't +get it to work in time. The problem was + + align:start position:0% +get it to work in time. The problem was + + + align:start position:0% +get it to work in time. The problem was +that even my $70,000 research microscope + + align:start position:0% +that even my $70,000 research microscope + + + align:start position:0% +that even my $70,000 research microscope +has trouble seeing the the + + align:start position:0% +has trouble seeing the the + + + align:start position:0% +has trouble seeing the the +bits. The bits are really + + align:start position:0% +bits. The bits are really + + + align:start position:0% +bits. The bits are really +small. So when I first tried it, I + + align:start position:0% +small. So when I first tried it, I + + + align:start position:0% +small. So when I first tried it, I +couldn't see + + align:start position:0% +couldn't see + + + align:start position:0% +couldn't see +anything. So I fiddled around with the + + align:start position:0% +anything. So I fiddled around with the + + + align:start position:0% +anything. So I fiddled around with the +microscope. I tried all different kinds + + align:start position:0% +microscope. I tried all different kinds + + + align:start position:0% +microscope. I tried all different kinds +of magnifications. I tried all kinds of + + align:start position:0% +of magnifications. I tried all kinds of + + + align:start position:0% +of magnifications. I tried all kinds of +different optical tricks that I know. I + + align:start position:0% +different optical tricks that I know. I + + + align:start position:0% +different optical tricks that I know. I +couldn't figure out anything. I couldn't + + align:start position:0% +couldn't figure out anything. I couldn't + + + align:start position:0% +couldn't figure out anything. I couldn't +get it to work. So I got my graduate + + align:start position:0% +get it to work. So I got my graduate + + + align:start position:0% +get it to work. So I got my graduate +students. They're always much better at + + align:start position:0% +students. They're always much better at + + + align:start position:0% +students. They're always much better at +this sort of thing. uh and we finally + + align:start position:0% +this sort of thing. uh and we finally + + + align:start position:0% +this sort of thing. uh and we finally +got it to work. We cheated like + + align:start position:0% +got it to work. We cheated like + + + align:start position:0% +got it to work. We cheated like +crazy. So we had to use something called + + align:start position:0% +crazy. So we had to use something called + + + align:start position:0% +crazy. So we had to use something called +water immersion. So uh you put a drop of + + align:start position:0% +water immersion. So uh you put a drop of + + + align:start position:0% +water immersion. So uh you put a drop of +water on the surface so that you can use + + align:start position:0% +water on the surface so that you can use + + + align:start position:0% +water on the surface so that you can use +the so you lose resolution when you go + + align:start position:0% +the so you lose resolution when you go + + + align:start position:0% +the so you lose resolution when you go +through an a um + + align:start position:0% +through an a um + + + align:start position:0% +through an a um +um glass to air + + align:start position:0% +um glass to air + + + align:start position:0% +um glass to air +interface. That's a bunch of microscopy + + align:start position:0% +interface. That's a bunch of microscopy + + + align:start position:0% +interface. That's a bunch of microscopy +that you don't need to know but you do. + + align:start position:0% +that you don't need to know but you do. + + + align:start position:0% +that you don't need to know but you do. +So there are tricks in microscopy where + + align:start position:0% +So there are tricks in microscopy where + + + align:start position:0% +So there are tricks in microscopy where +you can avoid having the air interface + + align:start position:0% +you can avoid having the air interface + + + align:start position:0% +you can avoid having the air interface +by using water. The water is more + + align:start position:0% +by using water. The water is more + + + align:start position:0% +by using water. The water is more +closely optically matched to glass. So + + align:start position:0% +closely optically matched to glass. So + + + align:start position:0% +closely optically matched to glass. So +what we did was we did u immersion + + align:start position:0% +what we did was we did u immersion + + + align:start position:0% +what we did was we did u immersion +microscopy. Put a drop of water on here. + + align:start position:0% +microscopy. Put a drop of water on here. + + + align:start position:0% +microscopy. Put a drop of water on here. +Put the lens in the water and that's the + + align:start position:0% +Put the lens in the water and that's the + + + align:start position:0% +Put the lens in the water and that's the +picture I + + align:start position:0% +picture I + + + align:start position:0% +picture I +got. So the point is that I had to + + align:start position:0% +got. So the point is that I had to + + + align:start position:0% +got. So the point is that I had to +work to get a $70,000 + + align:start position:0% +work to get a $70,000 + + + align:start position:0% +work to get a $70,000 +microscope to read the bits off here. + + align:start position:0% +microscope to read the bits off here. + + + align:start position:0% +microscope to read the bits off here. +And I sort of gave up with the idea that + + align:start position:0% +And I sort of gave up with the idea that + + + align:start position:0% +And I sort of gave up with the idea that +I would record a track because it was + + align:start position:0% +I would record a track because it was + + + align:start position:0% +I would record a track because it was +just too painful to just get this one + + align:start position:0% +just too painful to just get this one + + + align:start position:0% +just too painful to just get this one +image. Now, the trick is they make + + align:start position:0% +image. Now, the trick is they make + + + align:start position:0% +image. Now, the trick is they make +players that cost + + align:start position:0% +players that cost + + + align:start position:0% +players that cost +$10. What do they know that I don't + + align:start position:0% +$10. What do they know that I don't + + + align:start position:0% +$10. What do they know that I don't +know? Right? So, here I am with a + + align:start position:0% +know? Right? So, here I am with a + + + align:start position:0% +know? Right? So, here I am with a +$70,000 research microscope having a + + align:start position:0% +$70,000 research microscope having a + + + align:start position:0% +$70,000 research microscope having a +difficult time getting the bits off. How + + align:start position:0% +difficult time getting the bits off. How + + + align:start position:0% +difficult time getting the bits off. How +do they make a um a CD player for + + align:start position:0% +do they make a um a CD player for + + + align:start position:0% +do they make a um a CD player for +$10? Uh just for fun, I did the same + + align:start position:0% +$10? Uh just for fun, I did the same + + + align:start position:0% +$10? Uh just for fun, I did the same +thing with the DVD. After I figured out + + align:start position:0% +thing with the DVD. After I figured out + + + align:start position:0% +thing with the DVD. After I figured out +how to do the immersion microscopy, I + + align:start position:0% +how to do the immersion microscopy, I + + + align:start position:0% +how to do the immersion microscopy, I +figured I'd at least So, this is a DVD + + align:start position:0% +figured I'd at least So, this is a DVD + + + align:start position:0% +figured I'd at least So, this is a DVD +done with the same sort of + + align:start position:0% +done with the same sort of + + + align:start position:0% +done with the same sort of +thing. So, how do they do it? They do + + align:start position:0% +thing. So, how do they do it? They do + + + align:start position:0% +thing. So, how do they do it? They do +very clever things. The first trick they + + align:start position:0% +very clever things. The first trick they + + + align:start position:0% +very clever things. The first trick they +use is interference. So, I talked about + + align:start position:0% +use is interference. So, I talked about + + + align:start position:0% +use is interference. So, I talked about +interference last time with our uh + + align:start position:0% +interference last time with our uh + + + align:start position:0% +interference last time with our uh +standing wave illumination micros + + align:start position:0% +standing wave illumination micros + + + align:start position:0% +standing wave illumination micros +microscope. + + align:start position:0% +microscope. + + + align:start position:0% +microscope. +they do interference. So I told you that + + align:start position:0% +they do interference. So I told you that + + + align:start position:0% +they do interference. So I told you that +the that this is polycarbonate with an + + align:start position:0% +the that this is polycarbonate with an + + + align:start position:0% +the that this is polycarbonate with an +aluminum coating. The aluminum is + + align:start position:0% +aluminum coating. The aluminum is + + + align:start position:0% +aluminum coating. The aluminum is +actually working like a + + align:start position:0% +actually working like a + + + align:start position:0% +actually working like a +mirror and that's the intent. So they + + align:start position:0% +mirror and that's the intent. So they + + + align:start position:0% +mirror and that's the intent. So they +don't actually um try to code black and + + align:start position:0% +don't actually um try to code black and + + + align:start position:0% +don't actually um try to code black and +white. What they try to code is + + align:start position:0% +white. What they try to code is + + + align:start position:0% +white. What they try to code is +distance. So, the idea is that you take + + align:start position:0% +distance. So, the idea is that you take + + + align:start position:0% +distance. So, the idea is that you take +a laser beam and you you uh reflect it + + align:start position:0% +a laser beam and you you uh reflect it + + + align:start position:0% +a laser beam and you you uh reflect it +off of the CD much like it reflects off + + align:start position:0% +off of the CD much like it reflects off + + + align:start position:0% +off of the CD much like it reflects off +a + + align:start position:0% +a + + + align:start position:0% +a +mirror. And then the features that were + + align:start position:0% +mirror. And then the features that were + + + align:start position:0% +mirror. And then the features that were +embossed are at different depths and the + + align:start position:0% +embossed are at different depths and the + + + align:start position:0% +embossed are at different depths and the +depths chosen very specifically to be + + align:start position:0% +depths chosen very specifically to be + + + align:start position:0% +depths chosen very specifically to be +lambda over four. The wavelength of the + + align:start position:0% +lambda over four. The wavelength of the + + + align:start position:0% +lambda over four. The wavelength of the +light. They use a 700 nanometer + + align:start position:0% +light. They use a 700 nanometer + + + align:start position:0% +light. They use a 700 nanometer +laser and the de the um features are + + align:start position:0% +laser and the de the um features are + + + align:start position:0% +laser and the de the um features are +offset by lambda over + + align:start position:0% +offset by lambda over + + + align:start position:0% +offset by lambda over +four. The idea is that uh so if you have + + align:start position:0% +four. The idea is that uh so if you have + + + align:start position:0% +four. The idea is that uh so if you have +a + + align:start position:0% + + + + align:start position:0% + +feature and you have + + align:start position:0% +feature and you have + + + align:start position:0% +feature and you have +so you compare what would be the timing + + align:start position:0% +so you compare what would be the timing + + + align:start position:0% +so you compare what would be the timing +for this laser beam if it struck the + + align:start position:0% +for this laser beam if it struck the + + + align:start position:0% +for this laser beam if it struck the +mirror. You compare that to what it + + align:start position:0% +mirror. You compare that to what it + + + align:start position:0% +mirror. You compare that to what it +would be if it struck a feature and you + + align:start position:0% +would be if it struck a feature and you + + + align:start position:0% +would be if it struck a feature and you +rig it so that those two times are + + align:start position:0% +rig it so that those two times are + + + align:start position:0% +rig it so that those two times are +different by lambda over two. lambda + + align:start position:0% +different by lambda over two. lambda + + + align:start position:0% +different by lambda over two. lambda +over four in and lambda over four + + align:start position:0% +over four in and lambda over four + + + align:start position:0% +over four in and lambda over four +out. So then if you rig the + + align:start position:0% +out. So then if you rig the + + + align:start position:0% +out. So then if you rig the +beam to be half of the light falls on + + align:start position:0% +beam to be half of the light falls on + + + align:start position:0% +beam to be half of the light falls on +both, what's the sum of these waveforms + + align:start position:0% +both, what's the sum of these waveforms + + + align:start position:0% +both, what's the sum of these waveforms +going to be? If you have a component + + align:start position:0% +going to be? If you have a component + + + align:start position:0% +going to be? If you have a component +that's at the mirror and a component at + + align:start position:0% +that's at the mirror and a component at + + + align:start position:0% +that's at the mirror and a component at +the indented, if these are different in + + align:start position:0% +the indented, if these are different in + + + align:start position:0% +the indented, if these are different in +timing by lambda over two, when you add + + align:start position:0% +timing by lambda over two, when you add + + + align:start position:0% +timing by lambda over two, when you add +them, the answer + + align:start position:0% + + + + align:start position:0% + +is yeah, you get complete destructive + + align:start position:0% +is yeah, you get complete destructive + + + align:start position:0% +is yeah, you get complete destructive +interference. You get an answer of zero. + + align:start position:0% +interference. You get an answer of zero. + + + align:start position:0% +interference. You get an answer of zero. +So the idea in the reading of them is to + + align:start position:0% +So the idea in the reading of them is to + + + align:start position:0% +So the idea in the reading of them is to +use + + align:start position:0% +use + + + align:start position:0% +use +interference and rig it so that zeros + + align:start position:0% +interference and rig it so that zeros + + + align:start position:0% +interference and rig it so that zeros +are represented by no + + align:start position:0% +are represented by no + + + align:start position:0% +are represented by no +light and ones are represented by lots + + align:start position:0% +light and ones are represented by lots + + + align:start position:0% +light and ones are represented by lots +of light. Okay, so that's the first uh + + align:start position:0% +of light. Okay, so that's the first uh + + + align:start position:0% +of light. Okay, so that's the first uh +clever trick they + + align:start position:0% +clever trick they + + + align:start position:0% +clever trick they +do. Then the question is how do you + + align:start position:0% +do. Then the question is how do you + + + align:start position:0% +do. Then the question is how do you +focus it? Right? When I was doing my + + align:start position:0% +focus it? Right? When I was doing my + + + align:start position:0% +focus it? Right? When I was doing my +research um microscope, the research + + align:start position:0% +research um microscope, the research + + + align:start position:0% +research um microscope, the research +microscope first off it sits on a half + + align:start position:0% +microscope first off it sits on a half + + + align:start position:0% +microscope first off it sits on a half +ton of granite to make it all very + + align:start position:0% +ton of granite to make it all very + + + align:start position:0% +ton of granite to make it all very +stable because when you're doing the + + align:start position:0% +stable because when you're doing the + + + align:start position:0% +stable because when you're doing the +focusing you you don't want so the + + align:start position:0% +focusing you you don't want so the + + + align:start position:0% +focusing you you don't want so the +vibrations of the floor in my lab are + + align:start position:0% +vibrations of the floor in my lab are + + + align:start position:0% +vibrations of the floor in my lab are +about 100 nanometers about 100 + + align:start position:0% +about 100 nanometers about 100 + + + align:start position:0% +about 100 nanometers about 100 +micrometers + + align:start position:0% +micrometers + + + align:start position:0% +micrometers +sorry it's about 100 micrometers and I + + align:start position:0% +sorry it's about 100 micrometers and I + + + align:start position:0% +sorry it's about 100 micrometers and I +have to have the stability of the system + + align:start position:0% +have to have the stability of the system + + + align:start position:0% +have to have the stability of the system +sub micron so I use a h a table made out + + align:start position:0% +sub micron so I use a h a table made out + + + align:start position:0% +sub micron so I use a h a table made out +of a half ton of granite + + align:start position:0% +of a half ton of granite + + + align:start position:0% +of a half ton of granite +and the microscope sits on top of that + + align:start position:0% +and the microscope sits on top of that + + + align:start position:0% +and the microscope sits on top of that +and that makes everything nice and + + align:start position:0% +and that makes everything nice and + + + align:start position:0% +and that makes everything nice and +stable. They can't do that. So, how do + + align:start position:0% +stable. They can't do that. So, how do + + + align:start position:0% +stable. They can't do that. So, how do +they control the focus without using a + + align:start position:0% +they control the focus without using a + + + align:start position:0% +they control the focus without using a +half I mean it wouldn't work to make a + + align:start position:0% +half I mean it wouldn't work to make a + + + align:start position:0% +half I mean it wouldn't work to make a +walk band, you know, that is uh half ton + + align:start position:0% +walk band, you know, that is uh half ton + + + align:start position:0% +walk band, you know, that is uh half ton +granite, right? So, what do they do to + + align:start position:0% +granite, right? So, what do they do to + + + align:start position:0% +granite, right? So, what do they do to +enable them to um do the same kind of + + align:start position:0% +enable them to um do the same kind of + + + align:start position:0% +enable them to um do the same kind of +focusing that I was doing? They use + + align:start position:0% +focusing that I was doing? They use + + + align:start position:0% +focusing that I was doing? They use +feedback. So the idea is to substitute + + align:start position:0% +feedback. So the idea is to substitute + + + align:start position:0% +feedback. So the idea is to substitute +feedback for precision. So rather than + + align:start position:0% +feedback for precision. So rather than + + + align:start position:0% +feedback for precision. So rather than +trying to make the parts precise, they + + align:start position:0% +trying to make the parts precise, they + + + align:start position:0% +trying to make the parts precise, they +put the imprecise parts in a feedback + + align:start position:0% +put the imprecise parts in a feedback + + + align:start position:0% +put the imprecise parts in a feedback +loop. Very powerful + + align:start position:0% +loop. Very powerful + + + align:start position:0% +loop. Very powerful +method. So here's here's what they do. + + align:start position:0% +method. So here's here's what they do. + + + align:start position:0% +method. So here's here's what they do. +They take the laser, it's trying to + + align:start position:0% +They take the laser, it's trying to + + + align:start position:0% +They take the laser, it's trying to +focus onto the CD that has patterns in + + align:start position:0% +focus onto the CD that has patterns in + + + align:start position:0% +focus onto the CD that has patterns in +it. + + align:start position:0% + + + + align:start position:0% + +And uh so there's a beam splitter so + + align:start position:0% +And uh so there's a beam splitter so + + + align:start position:0% +And uh so there's a beam splitter so +that part of the light goes over to the + + align:start position:0% +that part of the light goes over to the + + + align:start position:0% +that part of the light goes over to the +detector. Excuse me, I didn't do that + + align:start position:0% +detector. Excuse me, I didn't do that + + + align:start position:0% +detector. Excuse me, I didn't do that +right. The laser squirts up to here, + + align:start position:0% +right. The laser squirts up to here, + + + align:start position:0% +right. The laser squirts up to here, +goes straight through the beam splitter, + + align:start position:0% +goes straight through the beam splitter, + + + align:start position:0% +goes straight through the beam splitter, +comes back through a focusing lens, + + align:start position:0% +comes back through a focusing lens, + + + align:start position:0% +comes back through a focusing lens, +bounces off the beam splitter through + + align:start position:0% +bounces off the beam splitter through + + + align:start position:0% +bounces off the beam splitter through +another lens, and hits a detector. So + + align:start position:0% +another lens, and hits a detector. So + + + align:start position:0% +another lens, and hits a detector. So +this is So the detector is this way. And + + align:start position:0% +this is So the detector is this way. And + + + align:start position:0% +this is So the detector is this way. And +I'm showing this view then. So the + + align:start position:0% +I'm showing this view then. So the + + + align:start position:0% +I'm showing this view then. So the +detector should be there. I'm showing a + + align:start position:0% +detector should be there. I'm showing a + + + align:start position:0% +detector should be there. I'm showing a +view of it over here. And it's um it's + + align:start position:0% +view of it over here. And it's um it's + + + align:start position:0% +view of it over here. And it's um it's +rigged so that these two lenses, one of + + align:start position:0% +rigged so that these two lenses, one of + + + align:start position:0% +rigged so that these two lenses, one of +the lenses is spherical and one is + + align:start position:0% +the lenses is spherical and one is + + + align:start position:0% +the lenses is spherical and one is +cylindrical. What that means is you + + align:start position:0% +cylindrical. What that means is you + + + align:start position:0% +cylindrical. What that means is you +remember uh I've talked about microscopy + + align:start position:0% +remember uh I've talked about microscopy + + + align:start position:0% +remember uh I've talked about microscopy +in the past out of focus means + + align:start position:0% +in the past out of focus means + + + align:start position:0% +in the past out of focus means +blurred. Blurred for a spot means + + align:start position:0% +blurred. Blurred for a spot means + + + align:start position:0% +blurred. Blurred for a spot means +bigger. As a as a microscope goes out of + + align:start position:0% +bigger. As a as a microscope goes out of + + + align:start position:0% +bigger. As a as a microscope goes out of +focus, the spot gets bigger. + + align:start position:0% +focus, the spot gets bigger. + + + align:start position:0% +focus, the spot gets bigger. +What you do with these two lenses + + align:start position:0% +What you do with these two lenses + + + align:start position:0% +What you do with these two lenses +because one is circularly symmetric and + + align:start position:0% +because one is circularly symmetric and + + + align:start position:0% +because one is circularly symmetric and +the other is cylindrically symmetric. + + align:start position:0% +the other is cylindrically symmetric. + + + align:start position:0% +the other is cylindrically symmetric. +What you do is you make the beam uh in + + align:start position:0% +What you do is you make the beam uh in + + + align:start position:0% +What you do is you make the beam uh in +this direction go out of focus as it's + + align:start position:0% +this direction go out of focus as it's + + + align:start position:0% +this direction go out of focus as it's +going into focus in this + + align:start position:0% + + + + align:start position:0% + +direction. Okay. So because you get two + + align:start position:0% +direction. Okay. So because you get two + + + align:start position:0% +direction. Okay. So because you get two +lenses, one is symmetric in XY and one + + align:start position:0% +lenses, one is symmetric in XY and one + + + align:start position:0% +lenses, one is symmetric in XY and one +has no magnification in Y but big + + align:start position:0% +has no magnification in Y but big + + + align:start position:0% +has no magnification in Y but big +magnification in X. You can rig it so + + align:start position:0% +magnification in X. You can rig it so + + + align:start position:0% +magnification in X. You can rig it so +that this dot will go out of focus + + align:start position:0% +that this dot will go out of focus + + + align:start position:0% +that this dot will go out of focus +horizontally while it's coming into + + align:start position:0% +horizontally while it's coming into + + + align:start position:0% +horizontally while it's coming into +focus + + align:start position:0% +focus + + + align:start position:0% +focus +vertically. The result is that if you + + align:start position:0% +vertically. The result is that if you + + + align:start position:0% +vertically. The result is that if you +move the CD closer, it becomes fat. + + align:start position:0% +move the CD closer, it becomes fat. + + + align:start position:0% +move the CD closer, it becomes fat. +And if you move the CD further, it + + align:start position:0% +And if you move the CD further, it + + + align:start position:0% +And if you move the CD further, it +becomes + + align:start position:0% +becomes + + + align:start position:0% +becomes +skinny. So all they need to do then is + + align:start position:0% +skinny. So all they need to do then is + + + align:start position:0% +skinny. So all they need to do then is +uh focus up and down until the dot is as + + align:start position:0% +uh focus up and down until the dot is as + + + align:start position:0% +uh focus up and down until the dot is as +close to being circular as they can get + + align:start position:0% +close to being circular as they can get + + + align:start position:0% +close to being circular as they can get +it. That's why they use a quadrant + + align:start position:0% +it. That's why they use a quadrant + + + align:start position:0% +it. That's why they use a quadrant +detector. So the quadrant detector lets + + align:start position:0% +detector. So the quadrant detector lets + + + align:start position:0% +detector. So the quadrant detector lets +them calculate a plus c minus b plus + + align:start position:0% +them calculate a plus c minus b plus + + + align:start position:0% +them calculate a plus c minus b plus +d. And you would like that answer to be + + align:start position:0% +d. And you would like that answer to be + + + align:start position:0% +d. And you would like that answer to be +zero. So now you use that as your error. + + align:start position:0% +zero. So now you use that as your error. + + + align:start position:0% +zero. So now you use that as your error. +You use the light that hits this + + align:start position:0% +You use the light that hits this + + + align:start position:0% +You use the light that hits this +quadrant + + align:start position:0% +quadrant + + + align:start position:0% +quadrant +detector to compute this number. Put + + align:start position:0% +detector to compute this number. Put + + + align:start position:0% +detector to compute this number. Put +that in a feedback loop that drives the + + align:start position:0% +that in a feedback loop that drives the + + + align:start position:0% +that in a feedback loop that drives the +stage up and down the focus. So here's + + align:start position:0% +stage up and down the focus. So here's + + + align:start position:0% +stage up and down the focus. So here's +an ancient CD. The CD would be here. + + align:start position:0% +an ancient CD. The CD would be here. + + + align:start position:0% +an ancient CD. The CD would be here. +Here's the the uh reading + + align:start position:0% +Here's the the uh reading + + + align:start position:0% +Here's the the uh reading +lens. Here's a platform that has an + + align:start position:0% +lens. Here's a platform that has an + + + align:start position:0% +lens. Here's a platform that has an +electromagnet under it that will move it + + align:start position:0% +electromagnet under it that will move it + + + align:start position:0% +electromagnet under it that will move it +up and down 100 microns. + + align:start position:0% +up and down 100 microns. + + + align:start position:0% +up and down 100 microns. +So what you do is + + align:start position:0% +So what you do is + + + align:start position:0% +So what you do is +um so this is this electro u magnet is + + align:start position:0% +um so this is this electro u magnet is + + + align:start position:0% +um so this is this electro u magnet is +under the stage. So this whole thing + + align:start position:0% +under the stage. So this whole thing + + + align:start position:0% +under the stage. So this whole thing +goes up and down to make in a feedback + + align:start position:0% +goes up and down to make in a feedback + + + align:start position:0% +goes up and down to make in a feedback +loop that tries to make this error + + align:start position:0% +loop that tries to make this error + + + align:start position:0% +loop that tries to make this error +signal be + + align:start position:0% +signal be + + + align:start position:0% +signal be +zero. Tries to make the pattern + + align:start position:0% +zero. Tries to make the pattern + + + align:start position:0% +zero. Tries to make the pattern +circularly symmetric. So it's extremely + + align:start position:0% +circularly symmetric. So it's extremely + + + align:start position:0% +circularly symmetric. So it's extremely +clever. + + align:start position:0% +clever. + + + align:start position:0% +clever. +Then + + align:start position:0% +Then + + + align:start position:0% +Then +uh you have this pattern. So the light + + align:start position:0% +uh you have this pattern. So the light + + + align:start position:0% +uh you have this pattern. So the light +is twice as big. Half the photons are + + align:start position:0% +is twice as big. Half the photons are + + + align:start position:0% +is twice as big. Half the photons are +supposed to fit in the pit and half the + + align:start position:0% +supposed to fit in the pit and half the + + + align:start position:0% +supposed to fit in the pit and half the +photons are supposed to hit in the land + + align:start position:0% +photons are supposed to hit in the land + + + align:start position:0% +photons are supposed to hit in the land +that surrounds the pit. + + align:start position:0% +that surrounds the pit. + + + align:start position:0% +that surrounds the pit. +So that as the um CD is + + align:start position:0% + + + + align:start position:0% + +spinning, if + + align:start position:0% +spinning, if + + + align:start position:0% +spinning, if +the spot illuminates a place that's + + align:start position:0% +the spot illuminates a place that's + + + align:start position:0% +the spot illuminates a place that's +entirely in the pit, the dot is small + + align:start position:0% +entirely in the pit, the dot is small + + + align:start position:0% +entirely in the pit, the dot is small +because of + + align:start position:0% +because of + + + align:start position:0% +because of +interference. And if it hits a place + + align:start position:0% +interference. And if it hits a place + + + align:start position:0% +interference. And if it hits a place +that doesn't have a pit, the dot is + + align:start position:0% +that doesn't have a pit, the dot is + + + align:start position:0% +that doesn't have a pit, the dot is +large because there's no interference. + + align:start position:0% +large because there's no interference. + + + align:start position:0% +large because there's no interference. +But then you have the problem of how do + + align:start position:0% +But then you have the problem of how do + + + align:start position:0% +But then you have the problem of how do +you keep the dot reading the center of + + align:start position:0% +you keep the dot reading the center of + + + align:start position:0% +you keep the dot reading the center of +the groove. Right? So in this technology + + align:start position:0% +the groove. Right? So in this technology + + + align:start position:0% +the groove. Right? So in this technology +we kept the dot in the center of the + + align:start position:0% +we kept the dot in the center of the + + + align:start position:0% +we kept the dot in the center of the +groove by using + + align:start position:0% +groove by using + + + align:start position:0% +groove by using +gravity. Right? We obviously don't want + + align:start position:0% +gravity. Right? We obviously don't want + + + align:start position:0% +gravity. Right? We obviously don't want +to touch that surface. So that's not the + + align:start position:0% +to touch that surface. So that's not the + + + align:start position:0% +to touch that surface. So that's not the +technology we use. We don't use a + + align:start position:0% +technology we use. We don't use a + + + align:start position:0% +technology we use. We don't use a +screw. We use feedback. Right? + + align:start position:0% +screw. We use feedback. Right? + + + align:start position:0% +screw. We use feedback. Right? +So in order to so here what we + + align:start position:0% +So in order to so here what we + + + align:start position:0% +So in order to so here what we +do instead of projecting a single dot we + + align:start position:0% +do instead of projecting a single dot we + + + align:start position:0% +do instead of projecting a single dot we +use a beam splitter that turns the one + + align:start position:0% +use a beam splitter that turns the one + + + align:start position:0% +use a beam splitter that turns the one +dot into three + + align:start position:0% +dot into three + + + align:start position:0% +dot into three +dots and the three dots are positioned + + align:start position:0% +dots and the three dots are positioned + + + align:start position:0% +dots and the three dots are positioned +so that they hit two more photo sensors + + align:start position:0% +so that they hit two more photo sensors + + + align:start position:0% +so that they hit two more photo sensors +one on each side of the main photo + + align:start position:0% +one on each side of the main photo + + + align:start position:0% +one on each side of the main photo +sensor. And the idea is that if the if + + align:start position:0% +sensor. And the idea is that if the if + + + align:start position:0% +sensor. And the idea is that if the if +the u light is perfectly centered on the + + align:start position:0% +the u light is perfectly centered on the + + + align:start position:0% +the u light is perfectly centered on the +track, these will have equal + + align:start position:0% +track, these will have equal + + + align:start position:0% +track, these will have equal +brightness. But now if the uh beam is + + align:start position:0% +brightness. But now if the uh beam is + + + align:start position:0% +brightness. But now if the uh beam is +off center, one of the dots will be + + align:start position:0% +off center, one of the dots will be + + + align:start position:0% +off center, one of the dots will be +bright because it hit all land compared + + align:start position:0% +bright because it hit all land compared + + + align:start position:0% +bright because it hit all land compared +to the other one which is some of the + + align:start position:0% +to the other one which is some of the + + + align:start position:0% +to the other one which is some of the +light is hitting the + + align:start position:0% +light is hitting the + + + align:start position:0% +light is hitting the +pit. So this is just like the head + + align:start position:0% +pit. So this is just like the head + + + align:start position:0% +pit. So this is just like the head +tracking thing in 601. + + align:start position:0% +tracking thing in 601. + + + align:start position:0% +tracking thing in 601. +So whichever of the two photo sensors + + align:start position:0% +So whichever of the two photo sensors + + + align:start position:0% +So whichever of the two photo sensors +gets more light, you um move the track + + align:start position:0% +gets more light, you um move the track + + + align:start position:0% +gets more light, you um move the track +to compensate for that. So it all works + + align:start position:0% +to compensate for that. So it all works + + + align:start position:0% +to compensate for that. So it all works +in a feedback + + align:start position:0% +in a feedback + + + align:start position:0% +in a feedback +loop. So the idea here is + + align:start position:0% + + + + align:start position:0% + +um the same sort of deal. You have two + + align:start position:0% +um the same sort of deal. You have two + + + align:start position:0% +um the same sort of deal. You have two +sensors here and you use that the error + + align:start position:0% +sensors here and you use that the error + + + align:start position:0% +sensors here and you use that the error +which is the difference between the two + + align:start position:0% +which is the difference between the two + + + align:start position:0% +which is the difference between the two +to u to move the head to track and the + + align:start position:0% +to u to move the head to track and the + + + align:start position:0% +to u to move the head to track and the +head motion is this thing over here. So + + align:start position:0% +head motion is this thing over here. So + + + align:start position:0% +head motion is this thing over here. So +here's a rack and pinion connected up to + + align:start position:0% +here's a rack and pinion connected up to + + + align:start position:0% +here's a rack and pinion connected up to +a motor and so you have that motor uh + + align:start position:0% +a motor and so you have that motor uh + + + align:start position:0% +a motor and so you have that motor uh +servoed back to some um photo sensors + + align:start position:0% +servoed back to some um photo sensors + + + align:start position:0% +servoed back to some um photo sensors +over here that keep the the beam + + align:start position:0% +over here that keep the the beam + + + align:start position:0% +over here that keep the the beam +centered. + + align:start position:0% + + + + align:start position:0% + +So the idea then is that what you get + + align:start position:0% +So the idea then is that what you get + + + align:start position:0% +So the idea then is that what you get +for $10 to read this thing is completely + + align:start position:0% +for $10 to read this thing is completely + + + align:start position:0% +for $10 to read this thing is completely +remarkable. The idea is that it's got + + align:start position:0% +remarkable. The idea is that it's got + + + align:start position:0% +remarkable. The idea is that it's got +very complicated servo mechanisms that + + align:start position:0% +very complicated servo mechanisms that + + + align:start position:0% +very complicated servo mechanisms that +can read very small things that even a + + align:start position:0% +can read very small things that even a + + + align:start position:0% +can read very small things that even a +$70,000 microscope has trouble + + align:start position:0% +$70,000 microscope has trouble + + + align:start position:0% +$70,000 microscope has trouble +reading. And it's stable and you can run + + align:start position:0% +reading. And it's stable and you can run + + + align:start position:0% +reading. And it's stable and you can run +them. You can, you know, jostle them + + align:start position:0% +them. You can, you know, jostle them + + + align:start position:0% +them. You can, you know, jostle them +around and jog with them. And that's all + + align:start position:0% +around and jog with them. And that's all + + + align:start position:0% +around and jog with them. And that's all +because the they use feedback rather + + align:start position:0% +because the they use feedback rather + + + align:start position:0% +because the they use feedback rather +than trying to make precision + + align:start position:0% +than trying to make precision + + + align:start position:0% +than trying to make precision +machining and then they make the signals + + align:start position:0% +machining and then they make the signals + + + align:start position:0% +machining and then they make the signals +robust by using the kind of DT signal + + align:start position:0% +robust by using the kind of DT signal + + + align:start position:0% +robust by using the kind of DT signal +processing that we talked about. So + + align:start position:0% +processing that we talked about. So + + + align:start position:0% +processing that we talked about. So +anyway, the point of today was just to + + align:start position:0% +anyway, the point of today was just to + + + align:start position:0% +anyway, the point of today was just to +give some motivation of the way 603 + + align:start position:0% +give some motivation of the way 603 + + + align:start position:0% +give some motivation of the way 603 +factors into technologies that you might + + align:start position:0% +factors into technologies that you might + + + align:start position:0% +factors into technologies that you might +be interested in. And this is just one + + align:start position:0% +be interested in. And this is just one + + + align:start position:0% +be interested in. And this is just one +example. I could have chosen any number + + align:start position:0% +example. I could have chosen any number + + + align:start position:0% +example. I could have chosen any number +of different devices and they would have + + align:start position:0% +of different devices and they would have + + + align:start position:0% +of different devices and they would have +been similar. So, I hope you enjoyed the + + align:start position:0% +been similar. So, I hope you enjoyed the + + + align:start position:0% +been similar. So, I hope you enjoyed the +course. I hope that you u have fun with + + align:start position:0% +course. I hope that you u have fun with + + + align:start position:0% +course. I hope that you u have fun with +the final. Please come on Tuesday and + + align:start position:0% +the final. Please come on Tuesday and + + + align:start position:0% +the final. Please come on Tuesday and +tell us uh what we should do differently + + align:start position:0% +tell us uh what we should do differently + + + align:start position:0% +tell us uh what we should do differently +next time. Thanks. \ No newline at end of file diff --git a/tEMkDHV2uU8.txt b/tEMkDHV2uU8.txt new file mode 100644 index 0000000000000000000000000000000000000000..5ad6b1e361d42da83323c2c93153f8e7c9ef8076 --- /dev/null +++ b/tEMkDHV2uU8.txt @@ -0,0 +1,5875 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT OpenCourseWare continue to + + align:start position:0% +will help MIT OpenCourseWare continue to + + + align:start position:0% +will help MIT OpenCourseWare continue to +offer high quality educational resources + + align:start position:0% +offer high quality educational resources + + + align:start position:0% +offer high quality educational resources +for free + + align:start position:0% +for free + + + align:start position:0% +for free +to make a donation or view additional + + align:start position:0% +to make a donation or view additional + + + align:start position:0% +to make a donation or view additional +materials from hundreds of MIT courses + + align:start position:0% +materials from hundreds of MIT courses + + + align:start position:0% +materials from hundreds of MIT courses +visit MIT opencourseware at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +and so just to go as an overview today + + align:start position:0% +and so just to go as an overview today + + + align:start position:0% +and so just to go as an overview today +we're going to be talking about + + align:start position:0% +we're going to be talking about + + + align:start position:0% +we're going to be talking about +different techniques to do that are used + + align:start position:0% +different techniques to do that are used + + + align:start position:0% +different techniques to do that are used +to determine protein structure and we + + align:start position:0% +to determine protein structure and we + + + align:start position:0% +to determine protein structure and we +were talking a little bit about the + + align:start position:0% +were talking a little bit about the + + + align:start position:0% +were talking a little bit about the +protein databank or the PDB and then the + + align:start position:0% +protein databank or the PDB and then the + + + align:start position:0% +protein databank or the PDB and then the +latter half of the recitation will be on + + align:start position:0% +latter half of the recitation will be on + + + align:start position:0% +latter half of the recitation will be on +we'll be doing a worksheet to look at + + align:start position:0% +we'll be doing a worksheet to look at + + + align:start position:0% +we'll be doing a worksheet to look at +the structure of ubiquitin and I you + + align:start position:0% +the structure of ubiquitin and I you + + + align:start position:0% +the structure of ubiquitin and I you +acquitted using PI mole so that's just + + align:start position:0% +acquitted using PI mole so that's just + + + align:start position:0% +acquitted using PI mole so that's just +to get you familiar with using PI mole + + align:start position:0% +to get you familiar with using PI mole + + + align:start position:0% +to get you familiar with using PI mole +and so for the first first question that + + align:start position:0% +and so for the first first question that + + + align:start position:0% +and so for the first first question that +I like to pose to you is why should we + + align:start position:0% +I like to pose to you is why should we + + + align:start position:0% +I like to pose to you is why should we +determine protein structure what we can + + align:start position:0% +determine protein structure what we can + + + align:start position:0% +determine protein structure what we can +learn from determining a protein + + align:start position:0% +learn from determining a protein + + + align:start position:0% +learn from determining a protein +structure and so I look to you for + + align:start position:0% +structure and so I look to you for + + + align:start position:0% +structure and so I look to you for +answers a lot of answers but doesn't + + align:start position:0% +answers a lot of answers but doesn't + + + align:start position:0% +answers a lot of answers but doesn't +really have any ideas yeah + + align:start position:0% + + + + align:start position:0% + +yeah absolutely yeah you can knowing + + align:start position:0% +yeah absolutely yeah you can knowing + + + align:start position:0% +yeah absolutely yeah you can knowing +protein structures does help you + + align:start position:0% +protein structures does help you + + + align:start position:0% +protein structures does help you +determine enzyme mechanisms anything + + align:start position:0% +determine enzyme mechanisms anything + + + align:start position:0% +determine enzyme mechanisms anything +else + + align:start position:0% + + + + align:start position:0% + +structure what yes absolutely structure + + align:start position:0% +structure what yes absolutely structure + + + align:start position:0% +structure what yes absolutely structure +does indicate function I can you be a + + align:start position:0% +does indicate function I can you be a + + + align:start position:0% +does indicate function I can you be a +bit more specific with respect to that + + align:start position:0% + + + + align:start position:0% + +yeah absolutely yeah you can determine + + align:start position:0% +yeah absolutely yeah you can determine + + + align:start position:0% +yeah absolutely yeah you can determine +active sites of enzymes + + align:start position:0% +active sites of enzymes + + + align:start position:0% +active sites of enzymes +any other ideas it's a lot more to go + + align:start position:0% + + + + align:start position:0% + +what about can you learn interactions + + align:start position:0% +what about can you learn interactions + + + align:start position:0% +what about can you learn interactions +with other macromolecules say okay well + + align:start position:0% +with other macromolecules say okay well + + + align:start position:0% +with other macromolecules say okay well +let's just go through some of them + + align:start position:0% +let's just go through some of them + + + align:start position:0% +let's just go through some of them +so yeah structure does indeed determine + + align:start position:0% +so yeah structure does indeed determine + + + align:start position:0% +so yeah structure does indeed determine +function and the idea is if you know the + + align:start position:0% +function and the idea is if you know the + + + align:start position:0% +function and the idea is if you know the +structure of a protein you can learn a + + align:start position:0% +structure of a protein you can learn a + + + align:start position:0% +structure of a protein you can learn a +lot about its function in vivo and so + + align:start position:0% +lot about its function in vivo and so + + + align:start position:0% +lot about its function in vivo and so +some of the things that you can study is + + align:start position:0% +some of the things that you can study is + + + align:start position:0% +some of the things that you can study is +you can set the enzyme mechanisms it's + + align:start position:0% +you can set the enzyme mechanisms it's + + + align:start position:0% +you can set the enzyme mechanisms it's +relatively hard to do in extra extra fee + + align:start position:0% +relatively hard to do in extra extra fee + + + align:start position:0% +relatively hard to do in extra extra fee +because every time you solve a crystal + + align:start position:0% +because every time you solve a crystal + + + align:start position:0% +because every time you solve a crystal +structure it's only one snapshot off the + + align:start position:0% +structure it's only one snapshot off the + + + align:start position:0% +structure it's only one snapshot off the +enzyme but you can definitely do it + + align:start position:0% +enzyme but you can definitely do it + + + align:start position:0% +enzyme but you can definitely do it +you can design drugs or substrate that + + align:start position:0% +you can design drugs or substrate that + + + align:start position:0% +you can design drugs or substrate that +bind to the protein if you know what the + + align:start position:0% +bind to the protein if you know what the + + + align:start position:0% +bind to the protein if you know what the +active site looks like you can design a + + align:start position:0% +active site looks like you can design a + + + align:start position:0% +active site looks like you can design a +high affinity inhibitor and this is used + + align:start position:0% +high affinity inhibitor and this is used + + + align:start position:0% +high affinity inhibitor and this is used +in farming this tree a lot you can study + + align:start position:0% +in farming this tree a lot you can study + + + align:start position:0% +in farming this tree a lot you can study +translation and transcription which is + + align:start position:0% +translation and transcription which is + + + align:start position:0% +translation and transcription which is +what we've been learning about in class + + align:start position:0% +what we've been learning about in class + + + align:start position:0% +what we've been learning about in class +this week and we'll be learning next + + align:start position:0% +this week and we'll be learning next + + + align:start position:0% +this week and we'll be learning next +week as well you can also make KO + + align:start position:0% +week as well you can also make KO + + + align:start position:0% +week as well you can also make KO +crystals of proteins with other proteins + + align:start position:0% +crystals of proteins with other proteins + + + align:start position:0% +crystals of proteins with other proteins +and nucleic acids and study interactions + + align:start position:0% +and nucleic acids and study interactions + + + align:start position:0% +and nucleic acids and study interactions +between macromolecules and this is + + align:start position:0% +between macromolecules and this is + + + align:start position:0% +between macromolecules and this is +something that has been emerging it + + align:start position:0% +something that has been emerging it + + + align:start position:0% +something that has been emerging it +makes it harder to solve the crystal + + align:start position:0% +makes it harder to solve the crystal + + + align:start position:0% +makes it harder to solve the crystal +structure but it's very x-ray is very + + align:start position:0% +structure but it's very x-ray is very + + + align:start position:0% +structure but it's very x-ray is very +extra crystallography is a very powerful + + align:start position:0% +extra crystallography is a very powerful + + + align:start position:0% +extra crystallography is a very powerful +tool for this you can also say the + + align:start position:0% +tool for this you can also say the + + + align:start position:0% +tool for this you can also say the +immune system function so this is more + + align:start position:0% +immune system function so this is more + + + align:start position:0% +immune system function so this is more +on the biological side of things you can + + align:start position:0% +on the biological side of things you can + + + align:start position:0% +on the biological side of things you can +study host-pathogen receptors and their + + align:start position:0% +study host-pathogen receptors and their + + + align:start position:0% +study host-pathogen receptors and their +interactions and many many more really + + align:start position:0% +interactions and many many more really + + + align:start position:0% +interactions and many many more really +there's no reason why you shouldn't have + + align:start position:0% +there's no reason why you shouldn't have + + + align:start position:0% +there's no reason why you shouldn't have +a structure for whatever protein you're + + align:start position:0% +a structure for whatever protein you're + + + align:start position:0% +a structure for whatever protein you're +studying right and so the key idea is + + align:start position:0% +studying right and so the key idea is + + + align:start position:0% +studying right and so the key idea is +that protein structures if you know the + + align:start position:0% +that protein structures if you know the + + + align:start position:0% +that protein structures if you know the +protein structure you can that allows + + align:start position:0% +protein structure you can that allows + + + align:start position:0% +protein structure you can that allows +you to carry out biochemical studies but + + align:start position:0% +you to carry out biochemical studies but + + + align:start position:0% +you to carry out biochemical studies but +then also if you if you determine the + + align:start position:0% +then also if you if you determine the + + + align:start position:0% +then also if you if you determine the +structure that can help rationalize + + align:start position:0% +structure that can help rationalize + + + align:start position:0% +structure that can help rationalize +results that you get from a chemical + + align:start position:0% +results that you get from a chemical + + + align:start position:0% +results that you get from a chemical +studies so it goes both ways and final + + align:start position:0% +studies so it goes both ways and final + + + align:start position:0% +studies so it goes both ways and final +point that is + + align:start position:0% +point that is + + + align:start position:0% +point that is +not perhaps not emphasized that much is + + align:start position:0% +not perhaps not emphasized that much is + + + align:start position:0% +not perhaps not emphasized that much is +the structure as a result of sequence + + align:start position:0% +the structure as a result of sequence + + + align:start position:0% +the structure as a result of sequence +and ideally what we would like to know + + align:start position:0% +and ideally what we would like to know + + + align:start position:0% +and ideally what we would like to know +is if we know the primary amino acid + + align:start position:0% +is if we know the primary amino acid + + + align:start position:0% +is if we know the primary amino acid +sequence of a polypeptide we'd like to + + align:start position:0% +sequence of a polypeptide we'd like to + + + align:start position:0% +sequence of a polypeptide we'd like to +be able to predict its complete t + + align:start position:0% +be able to predict its complete t + + + align:start position:0% +be able to predict its complete t +dimensional fold and that's sort of the + + align:start position:0% +dimensional fold and that's sort of the + + + align:start position:0% +dimensional fold and that's sort of the +idea behind protein folding we're not + + align:start position:0% +idea behind protein folding we're not + + + align:start position:0% +idea behind protein folding we're not +quite at that stage yet computationally + + align:start position:0% +quite at that stage yet computationally + + + align:start position:0% +quite at that stage yet computationally +and so that's why we need experiment + + align:start position:0% +and so that's why we need experiment + + + align:start position:0% +and so that's why we need experiment +data but that's something we're moving + + align:start position:0% +data but that's something we're moving + + + align:start position:0% +data but that's something we're moving +forward moving towards as a science and + + align:start position:0% +forward moving towards as a science and + + + align:start position:0% +forward moving towards as a science and +so just to go over I'm gonna cover the + + align:start position:0% +so just to go over I'm gonna cover the + + + align:start position:0% +so just to go over I'm gonna cover the +three main techniques and protein + + align:start position:0% +three main techniques and protein + + + align:start position:0% +three main techniques and protein +structure determination and so the first + + align:start position:0% +structure determination and so the first + + + align:start position:0% +structure determination and so the first +the most common one is extra traction + + align:start position:0% +the most common one is extra traction + + + align:start position:0% +the most common one is extra traction +and the I'll go over some of the details + + align:start position:0% +and the I'll go over some of the details + + + align:start position:0% +and the I'll go over some of the details +of x-ray later I'll be focusing on x-ray + + align:start position:0% +of x-ray later I'll be focusing on x-ray + + + align:start position:0% +of x-ray later I'll be focusing on x-ray +diffraction in this talk some of the + + align:start position:0% +diffraction in this talk some of the + + + align:start position:0% +diffraction in this talk some of the +selling points of x-ray diffraction are + + align:start position:0% +selling points of x-ray diffraction are + + + align:start position:0% +selling points of x-ray diffraction are +that you can study a protein of any size + + align:start position:0% +that you can study a protein of any size + + + align:start position:0% +that you can study a protein of any size +small proteins large proteins you can + + align:start position:0% +small proteins large proteins you can + + + align:start position:0% +small proteins large proteins you can +study complexes or proteins there is a + + align:start position:0% +study complexes or proteins there is a + + + align:start position:0% +study complexes or proteins there is a +need to crystallize your sample which + + align:start position:0% +need to crystallize your sample which + + + align:start position:0% +need to crystallize your sample which +makes a challenging it's very hard to + + align:start position:0% +makes a challenging it's very hard to + + + align:start position:0% +makes a challenging it's very hard to +crystallize proteins in your body no + + align:start position:0% +crystallize proteins in your body no + + + align:start position:0% +crystallize proteins in your body no +protein is crystallized right so you're + + align:start position:0% +protein is crystallized right so you're + + + align:start position:0% +protein is crystallized right so you're +trying to make proteins do something + + align:start position:0% +trying to make proteins do something + + + align:start position:0% +trying to make proteins do something +that they don't really like doing you + + align:start position:0% +that they don't really like doing you + + + align:start position:0% +that they don't really like doing you +can obtain a high resolution high + + align:start position:0% +can obtain a high resolution high + + + align:start position:0% +can obtain a high resolution high +resolution structure so a resolution of + + align:start position:0% +resolution structure so a resolution of + + + align:start position:0% +resolution structure so a resolution of +two angstroms or even less is pretty + + align:start position:0% +two angstroms or even less is pretty + + + align:start position:0% +two angstroms or even less is pretty +common for good protein x-ray structures + + align:start position:0% +common for good protein x-ray structures + + + align:start position:0% +common for good protein x-ray structures +but then also it's difficult to observe + + align:start position:0% +but then also it's difficult to observe + + + align:start position:0% +but then also it's difficult to observe +dynamics so an x-ray structure is just a + + align:start position:0% +dynamics so an x-ray structure is just a + + + align:start position:0% +dynamics so an x-ray structure is just a +snapshot of the protein at a specific + + align:start position:0% +snapshot of the protein at a specific + + + align:start position:0% +snapshot of the protein at a specific +time and so you need often a series of + + align:start position:0% +time and so you need often a series of + + + align:start position:0% +time and so you need often a series of +x-ray structures to really learn + + align:start position:0% +x-ray structures to really learn + + + align:start position:0% +x-ray structures to really learn +something about the mechanism or the + + align:start position:0% +something about the mechanism or the + + + align:start position:0% +something about the mechanism or the +dynamics of these proteins another + + align:start position:0% +dynamics of these proteins another + + + align:start position:0% +dynamics of these proteins another +common the second most popular technique + + align:start position:0% +common the second most popular technique + + + align:start position:0% +common the second most popular technique +is nuclear magnetic resonance or NMR NMR + + align:start position:0% +is nuclear magnetic resonance or NMR NMR + + + align:start position:0% +is nuclear magnetic resonance or NMR NMR +is typically used to study small + + align:start position:0% +is typically used to study small + + + align:start position:0% +is typically used to study small +proteins and the reason for this is that + + align:start position:0% +proteins and the reason for this is that + + + align:start position:0% +proteins and the reason for this is that +if you look at this so this is a 2d NMR + + align:start position:0% +if you look at this so this is a 2d NMR + + + align:start position:0% +if you look at this so this is a 2d NMR +spectra if you look at the 2d NMR + + align:start position:0% +spectra if you look at the 2d NMR + + + align:start position:0% +spectra if you look at the 2d NMR +spectra there's a lot of Peaks right and + + align:start position:0% +spectra there's a lot of Peaks right and + + + align:start position:0% +spectra there's a lot of Peaks right and +the more residues you have the more + + align:start position:0% +the more residues you have the more + + + align:start position:0% +the more residues you have the more +amino acids you have the more Peaks you + + align:start position:0% +amino acids you have the more Peaks you + + + align:start position:0% +amino acids you have the more Peaks you +have and it gets very crowded and so + + align:start position:0% +have and it gets very crowded and so + + + align:start position:0% +have and it gets very crowded and so +that's sort of the limiting factor with + + align:start position:0% +that's sort of the limiting factor with + + + align:start position:0% +that's sort of the limiting factor with +with using NMR to study larger proteins + + align:start position:0% +with using NMR to study larger proteins + + + align:start position:0% +with using NMR to study larger proteins +is that you can't resolve all the + + align:start position:0% +is that you can't resolve all the + + + align:start position:0% +is that you can't resolve all the +chemical shifts the plus point is that + + align:start position:0% +chemical shifts the plus point is that + + + align:start position:0% +chemical shifts the plus point is that +there's no need to crystallize your + + align:start position:0% +there's no need to crystallize your + + + align:start position:0% +there's no need to crystallize your +protein you can study it in solution + + align:start position:0% +protein you can study it in solution + + + align:start position:0% +protein you can study it in solution +state or solid state so let's state NMR + + align:start position:0% +state or solid state so let's state NMR + + + align:start position:0% +state or solid state so let's state NMR +is typically used for membrane proteins + + align:start position:0% +is typically used for membrane proteins + + + align:start position:0% +is typically used for membrane proteins +and solution you can use you can use + + align:start position:0% +and solution you can use you can use + + + align:start position:0% +and solution you can use you can use +Marcus Ellie any soluble proteins you do + + align:start position:0% +Marcus Ellie any soluble proteins you do + + + align:start position:0% +Marcus Ellie any soluble proteins you do +need isotopically labeled samples so + + align:start position:0% +need isotopically labeled samples so + + + align:start position:0% +need isotopically labeled samples so +these are 13 C or 15 n enriched samples + + align:start position:0% +these are 13 C or 15 n enriched samples + + + align:start position:0% +these are 13 C or 15 n enriched samples +which is very hard and expensive to do + + align:start position:0% +which is very hard and expensive to do + + + align:start position:0% +which is very hard and expensive to do +so that's one of the drawbacks with NMR + + align:start position:0% +so that's one of the drawbacks with NMR + + + align:start position:0% +so that's one of the drawbacks with NMR +is that it's a relatively expensive + + align:start position:0% +is that it's a relatively expensive + + + align:start position:0% +is that it's a relatively expensive +technique well x-ray is more is more + + align:start position:0% +technique well x-ray is more is more + + + align:start position:0% +technique well x-ray is more is more +accessible you can obtain a + + align:start position:0% +accessible you can obtain a + + + align:start position:0% +accessible you can obtain a +high-resolution picture with NMR as well + + align:start position:0% +high-resolution picture with NMR as well + + + align:start position:0% +high-resolution picture with NMR as well +but it often requires more work than + + align:start position:0% +but it often requires more work than + + + align:start position:0% +but it often requires more work than +x-ray crystallography in that you need + + align:start position:0% +x-ray crystallography in that you need + + + align:start position:0% +x-ray crystallography in that you need +to do about say 5 experiments NMR + + align:start position:0% +to do about say 5 experiments NMR + + + align:start position:0% +to do about say 5 experiments NMR +experiments that can sometimes take + + align:start position:0% +experiments that can sometimes take + + + align:start position:0% +experiments that can sometimes take +months to determine high resolution + + align:start position:0% +months to determine high resolution + + + align:start position:0% +months to determine high resolution +structure x-ray is more accessible but + + align:start position:0% +structure x-ray is more accessible but + + + align:start position:0% +structure x-ray is more accessible but +really the big upshot of NMR is that you + + align:start position:0% +really the big upshot of NMR is that you + + + align:start position:0% +really the big upshot of NMR is that you +can observe dynamics within proteins so + + align:start position:0% +can observe dynamics within proteins so + + + align:start position:0% +can observe dynamics within proteins so +you can really see proteins are living + + align:start position:0% +you can really see proteins are living + + + align:start position:0% +you can really see proteins are living +breathing machines and you can see that + + align:start position:0% +breathing machines and you can see that + + + align:start position:0% +breathing machines and you can see that +with NMR better than you can with any + + align:start position:0% +with NMR better than you can with any + + + align:start position:0% +with NMR better than you can with any +other technique another quick point + + align:start position:0% +other technique another quick point + + + align:start position:0% +other technique another quick point +which I don't have written up here is + + align:start position:0% +which I don't have written up here is + + + align:start position:0% +which I don't have written up here is +that NMR is sensitive to protons and you + + align:start position:0% +that NMR is sensitive to protons and you + + + align:start position:0% +that NMR is sensitive to protons and you +can study hydrogen's with NMR you cannot + + align:start position:0% +can study hydrogen's with NMR you cannot + + + align:start position:0% +can study hydrogen's with NMR you cannot +study hydrogens with x-ray diffraction + + align:start position:0% +study hydrogens with x-ray diffraction + + + align:start position:0% +study hydrogens with x-ray diffraction +on for reasons that we'll come back to + + align:start position:0% +on for reasons that we'll come back to + + + align:start position:0% +on for reasons that we'll come back to +later in the talk + + align:start position:0% + + + + align:start position:0% + +yes so there are a series of different I + + align:start position:0% +yes so there are a series of different I + + + align:start position:0% +yes so there are a series of different I +don't know how much detail you guys know + + align:start position:0% +don't know how much detail you guys know + + + align:start position:0% +don't know how much detail you guys know +about Emma but basically you can study + + align:start position:0% +about Emma but basically you can study + + + align:start position:0% +about Emma but basically you can study +relaxation of nuclei that's often one + + align:start position:0% +relaxation of nuclei that's often one + + + align:start position:0% +relaxation of nuclei that's often one +that's used so you study t1 and to treat + + align:start position:0% +that's used so you study t1 and to treat + + + align:start position:0% +that's used so you study t1 and to treat +relaxation of nuclei and more mobile + + align:start position:0% +relaxation of nuclei and more mobile + + + align:start position:0% +relaxation of nuclei and more mobile +residues or more mobile atoms relax + + align:start position:0% +residues or more mobile atoms relax + + + align:start position:0% +residues or more mobile atoms relax +faster but really the idea is you can + + align:start position:0% +faster but really the idea is you can + + + align:start position:0% +faster but really the idea is you can +use their whole different their whole + + align:start position:0% +use their whole different their whole + + + align:start position:0% +use their whole different their whole +bunch of different experiments in NMR + + align:start position:0% +bunch of different experiments in NMR + + + align:start position:0% +bunch of different experiments in NMR +and you can access time skills from the + + align:start position:0% +and you can access time skills from the + + + align:start position:0% +and you can access time skills from the +nanosecond up till the milliseconds so + + align:start position:0% +nanosecond up till the milliseconds so + + + align:start position:0% +nanosecond up till the milliseconds so +you know 10 to the negative 9 to about + + align:start position:0% +you know 10 to the negative 9 to about + + + align:start position:0% +you know 10 to the negative 9 to about +10 to the negative 3 seconds of motion + + align:start position:0% +10 to the negative 3 seconds of motion + + + align:start position:0% +10 to the negative 3 seconds of motion +so it's quite and we use different + + align:start position:0% +so it's quite and we use different + + + align:start position:0% +so it's quite and we use different +experiments for different parts of that + + align:start position:0% +experiments for different parts of that + + + align:start position:0% +experiments for different parts of that +time scale and we can talk more about + + align:start position:0% +time scale and we can talk more about + + + align:start position:0% +time scale and we can talk more about +that in in detail the third technique is + + align:start position:0% +that in in detail the third technique is + + + align:start position:0% +that in in detail the third technique is +electron microscopy + + align:start position:0% +electron microscopy + + + align:start position:0% +electron microscopy +so this is restricted so far to large + + align:start position:0% +so this is restricted so far to large + + + align:start position:0% +so this is restricted so far to large +proteins the reason for this is that + + align:start position:0% +proteins the reason for this is that + + + align:start position:0% +proteins the reason for this is that +resolution is not so good again you + + align:start position:0% +resolution is not so good again you + + + align:start position:0% +resolution is not so good again you +don't need to crystallize your proteins + + align:start position:0% +don't need to crystallize your proteins + + + align:start position:0% +don't need to crystallize your proteins +so that's that's not red you don't need + + align:start position:0% +so that's that's not red you don't need + + + align:start position:0% +so that's that's not red you don't need +to use label samples either so the + + align:start position:0% +to use label samples either so the + + + align:start position:0% +to use label samples either so the +sample preparation is probably the + + align:start position:0% +sample preparation is probably the + + + align:start position:0% +sample preparation is probably the +easiest for for electron microscopy the + + align:start position:0% +easiest for for electron microscopy the + + + align:start position:0% +easiest for for electron microscopy the +picture that you get is sometimes low + + align:start position:0% +picture that you get is sometimes low + + + align:start position:0% +picture that you get is sometimes low +resolution because but the but the + + align:start position:0% +resolution because but the but the + + + align:start position:0% +resolution because but the but the +technology is moving forward to the + + align:start position:0% +technology is moving forward to the + + + align:start position:0% +technology is moving forward to the +point where we can get resolution as + + align:start position:0% +point where we can get resolution as + + + align:start position:0% +point where we can get resolution as +good as x-ray structures and I think I + + align:start position:0% +good as x-ray structures and I think I + + + align:start position:0% +good as x-ray structures and I think I +know that there's a 2.2 angstrom + + align:start position:0% +know that there's a 2.2 angstrom + + + align:start position:0% +know that there's a 2.2 angstrom +resolution structure out there + + align:start position:0% +resolution structure out there + + + align:start position:0% +resolution structure out there +definitely and there are others there + + align:start position:0% +definitely and there are others there + + + align:start position:0% +definitely and there are others there +are 3 point 2 angstroms but maybe + + align:start position:0% +are 3 point 2 angstroms but maybe + + + align:start position:0% +are 3 point 2 angstroms but maybe +there's something better than that out + + align:start position:0% +there's something better than that out + + + align:start position:0% +there's something better than that out +there in the literature again it's + + align:start position:0% +there in the literature again it's + + + align:start position:0% +there in the literature again it's +difficult to observe dynamics so similar + + align:start position:0% +difficult to observe dynamics so similar + + + align:start position:0% +difficult to observe dynamics so similar +to x-ray it's just a snapshot of your + + align:start position:0% +to x-ray it's just a snapshot of your + + + align:start position:0% +to x-ray it's just a snapshot of your +enzyme + + align:start position:0% + + + + align:start position:0% + +like yeah yeah absolutely it is very + + align:start position:0% +like yeah yeah absolutely it is very + + + align:start position:0% +like yeah yeah absolutely it is very +similar and you're the only thing is + + align:start position:0% +similar and you're the only thing is + + + align:start position:0% +similar and you're the only thing is +you're you're looking at how electrons + + align:start position:0% +you're you're looking at how electrons + + + align:start position:0% +you're you're looking at how electrons +interact with your métier sample as + + align:start position:0% +interact with your métier sample as + + + align:start position:0% +interact with your métier sample as +compared to light right visible light I + + align:start position:0% +compared to light right visible light I + + + align:start position:0% +compared to light right visible light I +guess + + align:start position:0% +guess + + + align:start position:0% +guess +and yeah you basically each so each of + + align:start position:0% +and yeah you basically each so each of + + + align:start position:0% +and yeah you basically each so each of +these particles here is and is is your + + align:start position:0% +these particles here is and is is your + + + align:start position:0% +these particles here is and is is your +protein is a protein molecule and then + + align:start position:0% +protein is a protein molecule and then + + + align:start position:0% +protein is a protein molecule and then +these are three-dimensional + + align:start position:0% +these are three-dimensional + + + align:start position:0% +these are three-dimensional +reconstruction + + align:start position:0% +reconstruction + + + align:start position:0% +reconstruction +so there's computer software that does + + align:start position:0% +so there's computer software that does + + + align:start position:0% +so there's computer software that does +this so to go from this you basically a + + align:start position:0% +this so to go from this you basically a + + + align:start position:0% +this so to go from this you basically a +signal average over all of these + + align:start position:0% +signal average over all of these + + + align:start position:0% +signal average over all of these +different molecules and then you signal + + align:start position:0% +different molecules and then you signal + + + align:start position:0% +different molecules and then you signal +average all over all of your different + + align:start position:0% +average all over all of your different + + + align:start position:0% +average all over all of your different +orientations of the protein that are + + align:start position:0% +orientations of the protein that are + + + align:start position:0% +orientations of the protein that are +trapped in your static electron + + align:start position:0% +trapped in your static electron + + + align:start position:0% +trapped in your static electron +microscope image and then using some + + align:start position:0% +microscope image and then using some + + + align:start position:0% +microscope image and then using some +image processing you generate a + + align:start position:0% +image processing you generate a + + + align:start position:0% +image processing you generate a +three-dimensional image of your protein + + align:start position:0% +three-dimensional image of your protein + + + align:start position:0% +three-dimensional image of your protein +that has a higher resolution than what + + align:start position:0% +that has a higher resolution than what + + + align:start position:0% +that has a higher resolution than what +you can see just with you know one + + align:start position:0% +you can see just with you know one + + + align:start position:0% +you can see just with you know one +single photo I guess so there's a lot of + + align:start position:0% +single photo I guess so there's a lot of + + + align:start position:0% +single photo I guess so there's a lot of +computer processing that happens behind + + align:start position:0% +computer processing that happens behind + + + align:start position:0% +computer processing that happens behind +the scenes okay yeah sorry + + align:start position:0% + + + + align:start position:0% + +so fluorescence the difference with + + align:start position:0% +so fluorescence the difference with + + + align:start position:0% +so fluorescence the difference with +fluorescence I mean here electrons can + + align:start position:0% +fluorescence I mean here electrons can + + + align:start position:0% +fluorescence I mean here electrons can +interact with any atoms right any + + align:start position:0% +interact with any atoms right any + + + align:start position:0% +interact with any atoms right any +material + + align:start position:0% + + + + align:start position:0% + +yes you can because different atoms + + align:start position:0% +yes you can because different atoms + + + align:start position:0% +yes you can because different atoms +interact with different nuclei interact + + align:start position:0% +interact with different nuclei interact + + + align:start position:0% +interact with different nuclei interact +an electron density is interact with + + align:start position:0% +an electron density is interact with + + + align:start position:0% +an electron density is interact with +electrons differently but with + + align:start position:0% +electrons differently but with + + + align:start position:0% +electrons differently but with +fluorescence microscopy you're usually + + align:start position:0% +fluorescence microscopy you're usually + + + align:start position:0% +fluorescence microscopy you're usually +looking at just a single molecule a + + align:start position:0% +looking at just a single molecule a + + + align:start position:0% +looking at just a single molecule a +fluorophore + + align:start position:0% +fluorophore + + + align:start position:0% +fluorophore +right that's reporting on where your + + align:start position:0% +right that's reporting on where your + + + align:start position:0% +right that's reporting on where your +protein is but electron microscopy is a + + align:start position:0% +protein is but electron microscopy is a + + + align:start position:0% +protein is but electron microscopy is a +much higher resolution picture it's + + align:start position:0% +much higher resolution picture it's + + + align:start position:0% +much higher resolution picture it's +actually an Adamek level well maybe a + + align:start position:0% +actually an Adamek level well maybe a + + + align:start position:0% +actually an Adamek level well maybe a +few atoms level picture fluorescence + + align:start position:0% +few atoms level picture fluorescence + + + align:start position:0% +few atoms level picture fluorescence +microscopy is usually just used to study + + align:start position:0% +microscopy is usually just used to study + + + align:start position:0% +microscopy is usually just used to study +where your protein is if proteins are + + align:start position:0% +where your protein is if proteins are + + + align:start position:0% +where your protein is if proteins are +interacting so that's more macro + + align:start position:0% +interacting so that's more macro + + + align:start position:0% +interacting so that's more macro +molecular interactions but you can get + + align:start position:0% +molecular interactions but you can get + + + align:start position:0% +molecular interactions but you can get +single molecule resolution with + + align:start position:0% +single molecule resolution with + + + align:start position:0% +single molecule resolution with +fluorescence microscopy if you use the + + align:start position:0% +fluorescence microscopy if you use the + + + align:start position:0% +fluorescence microscopy if you use the +correct techniques and so just as an + + align:start position:0% +correct techniques and so just as an + + + align:start position:0% +correct techniques and so just as an +introduction to the protein databank + + align:start position:0% +introduction to the protein databank + + + align:start position:0% +introduction to the protein databank +so the first graph tells you the number + + align:start position:0% +so the first graph tells you the number + + + align:start position:0% +so the first graph tells you the number +of PDB structures in the PDB as a + + align:start position:0% +of PDB structures in the PDB as a + + + align:start position:0% +of PDB structures in the PDB as a +function of year going from 1975 all the + + align:start position:0% +function of year going from 1975 all the + + + align:start position:0% +function of year going from 1975 all the +way to 2015 and so you'll see today + + align:start position:0% +way to 2015 and so you'll see today + + + align:start position:0% +way to 2015 and so you'll see today +there are about 110,000 structures of + + align:start position:0% +there are about 110,000 structures of + + + align:start position:0% +there are about 110,000 structures of +which a hundred thousand were deposited + + align:start position:0% +which a hundred thousand were deposited + + + align:start position:0% +which a hundred thousand were deposited +our work determined using x-ray + + align:start position:0% +our work determined using x-ray + + + align:start position:0% +our work determined using x-ray +crystallography and about ten thousand + + align:start position:0% +crystallography and about ten thousand + + + align:start position:0% +crystallography and about ten thousand +using NMR and about a thousand using + + align:start position:0% +using NMR and about a thousand using + + + align:start position:0% +using NMR and about a thousand using +I'll try microscopy it's a really quite + + align:start position:0% +I'll try microscopy it's a really quite + + + align:start position:0% +I'll try microscopy it's a really quite +a nice ratio there and if you see the + + align:start position:0% +a nice ratio there and if you see the + + + align:start position:0% +a nice ratio there and if you see the +yearly increase in the number of PDB + + align:start position:0% +yearly increase in the number of PDB + + + align:start position:0% +yearly increase in the number of PDB +structures you'll see that x-ray is of + + align:start position:0% +structures you'll see that x-ray is of + + + align:start position:0% +structures you'll see that x-ray is of +course really big NMR has been fairly + + align:start position:0% +course really big NMR has been fairly + + + align:start position:0% +course really big NMR has been fairly +consistent over time I think that has to + + align:start position:0% +consistent over time I think that has to + + + align:start position:0% +consistent over time I think that has to +do with the fact that it's expensive and + + align:start position:0% +do with the fact that it's expensive and + + + align:start position:0% +do with the fact that it's expensive and +it takes time to prepare your samples + + align:start position:0% +it takes time to prepare your samples + + + align:start position:0% +it takes time to prepare your samples +but you also see a huge spike in + + align:start position:0% +but you also see a huge spike in + + + align:start position:0% +but you also see a huge spike in +electron microscopy of late and so with + + align:start position:0% +electron microscopy of late and so with + + + align:start position:0% +electron microscopy of late and so with +the advent of cryo am a lot more a lot + + align:start position:0% +the advent of cryo am a lot more a lot + + + align:start position:0% +the advent of cryo am a lot more a lot +more people start using cryo-em to + + align:start position:0% +more people start using cryo-em to + + + align:start position:0% +more people start using cryo-em to +determine protein structure + + align:start position:0% + + + + align:start position:0% + +yeah it can be but so for the problem + + align:start position:0% +yeah it can be but so for the problem + + + align:start position:0% +yeah it can be but so for the problem +with that is when you put your sample in + + align:start position:0% +with that is when you put your sample in + + + align:start position:0% +with that is when you put your sample in +the derailleur you can get chemical + + align:start position:0% +the derailleur you can get chemical + + + align:start position:0% +the derailleur you can get chemical +shifts information but chemical shift + + align:start position:0% +shifts information but chemical shift + + + align:start position:0% +shifts information but chemical shift +doesn't tell you anything about protein + + align:start position:0% +doesn't tell you anything about protein + + + align:start position:0% +doesn't tell you anything about protein +structure I mean it tells you a little + + align:start position:0% +structure I mean it tells you a little + + + align:start position:0% +structure I mean it tells you a little +bit about it tells you about what the + + align:start position:0% +bit about it tells you about what the + + + align:start position:0% +bit about it tells you about what the +electron density is at the atoms but + + align:start position:0% +electron density is at the atoms but + + + align:start position:0% +electron density is at the atoms but +what you really need to get from NMR + + align:start position:0% +what you really need to get from NMR + + + align:start position:0% +what you really need to get from NMR +experiments are distance restraints and + + align:start position:0% +experiments are distance restraints and + + + align:start position:0% +experiments are distance restraints and +so this is through space experiments so + + align:start position:0% +so this is through space experiments so + + + align:start position:0% +so this is through space experiments so +you can say that oh you know this carbon + + align:start position:0% +you can say that oh you know this carbon + + + align:start position:0% +you can say that oh you know this carbon +this one carbon nuclei is at a distance + + align:start position:0% +this one carbon nuclei is at a distance + + + align:start position:0% +this one carbon nuclei is at a distance +of six angstroms away from this other + + align:start position:0% +of six angstroms away from this other + + + align:start position:0% +of six angstroms away from this other +carbon nuclei and you typically want to + + align:start position:0% +carbon nuclei and you typically want to + + + align:start position:0% +carbon nuclei and you typically want to +accumulate about five restraints per + + align:start position:0% +accumulate about five restraints per + + + align:start position:0% +accumulate about five restraints per +atom and so to collect you know five + + align:start position:0% +atom and so to collect you know five + + + align:start position:0% +atom and so to collect you know five +times how many other atoms you have in + + align:start position:0% +times how many other atoms you have in + + + align:start position:0% +times how many other atoms you have in +your sample it can take time it's hard + + align:start position:0% +your sample it can take time it's hard + + + align:start position:0% +your sample it can take time it's hard +to do so a chemical shift by itself + + align:start position:0% +to do so a chemical shift by itself + + + align:start position:0% +to do so a chemical shift by itself +doesn't tell you much about protein + + align:start position:0% +doesn't tell you much about protein + + + align:start position:0% +doesn't tell you much about protein +structure any other questions all right + + align:start position:0% +structure any other questions all right + + + align:start position:0% +structure any other questions all right +so so now we will focus the rest of the + + align:start position:0% +so so now we will focus the rest of the + + + align:start position:0% +so so now we will focus the rest of the +talk on well for another part of the + + align:start position:0% +talk on well for another part of the + + + align:start position:0% +talk on well for another part of the +talk on x-axis lovely and so + + align:start position:0% +talk on x-axis lovely and so + + + align:start position:0% +talk on x-axis lovely and so +crystallography is the science of + + align:start position:0% +crystallography is the science of + + + align:start position:0% +crystallography is the science of +determining the three-dimensional + + align:start position:0% +determining the three-dimensional + + + align:start position:0% +determining the three-dimensional +position of atoms in in a crystal and so + + align:start position:0% +position of atoms in in a crystal and so + + + align:start position:0% +position of atoms in in a crystal and so +what a crystal is a crystal is a solid + + align:start position:0% +what a crystal is a crystal is a solid + + + align:start position:0% +what a crystal is a crystal is a solid +material whose constituents are arranged + + align:start position:0% +material whose constituents are arranged + + + align:start position:0% +material whose constituents are arranged +in an ordered pattern expanding and + + align:start position:0% +in an ordered pattern expanding and + + + align:start position:0% +in an ordered pattern expanding and +extending in all three spatial + + align:start position:0% +extending in all three spatial + + + align:start position:0% +extending in all three spatial +dimensions and so the key idea is that + + align:start position:0% +dimensions and so the key idea is that + + + align:start position:0% +dimensions and so the key idea is that +there's translation translational + + align:start position:0% +there's translation translational + + + align:start position:0% +there's translation translational +symmetry to be go in any of the three + + align:start position:0% +symmetry to be go in any of the three + + + align:start position:0% +symmetry to be go in any of the three +directions started for a certain amount + + align:start position:0% +directions started for a certain amount + + + align:start position:0% +directions started for a certain amount +of time or certain amount of length + + align:start position:0% +of time or certain amount of length + + + align:start position:0% +of time or certain amount of length +you'll come back to the same pattern + + align:start position:0% +you'll come back to the same pattern + + + align:start position:0% +you'll come back to the same pattern +that you start off with and so this is + + align:start position:0% +that you start off with and so this is + + + align:start position:0% +that you start off with and so this is +say a crystal off your protein of + + align:start position:0% +say a crystal off your protein of + + + align:start position:0% +say a crystal off your protein of +interest what you want to know is you + + align:start position:0% +interest what you want to know is you + + + align:start position:0% +interest what you want to know is you +want to know how the proteins are packed + + align:start position:0% +want to know how the proteins are packed + + + align:start position:0% +want to know how the proteins are packed +or arranged within this crystal + + align:start position:0% +or arranged within this crystal + + + align:start position:0% +or arranged within this crystal +structure and also as a result how the + + align:start position:0% +structure and also as a result how the + + + align:start position:0% +structure and also as a result how the +atoms are arranged within the crystal + + align:start position:0% +atoms are arranged within the crystal + + + align:start position:0% +atoms are arranged within the crystal +structure and the way this works is by + + align:start position:0% +structure and the way this works is by + + + align:start position:0% +structure and the way this works is by +diffracting x-rays through your sample + + align:start position:0% +diffracting x-rays through your sample + + + align:start position:0% +diffracting x-rays through your sample +of interests and with this slide I just + + align:start position:0% +of interests and with this slide I just + + + align:start position:0% +of interests and with this slide I just +wanted to point out that it's not + + align:start position:0% +wanted to point out that it's not + + + align:start position:0% +wanted to point out that it's not +restricted to proteins you can study + + align:start position:0% +restricted to proteins you can study + + + align:start position:0% +restricted to proteins you can study +salt so you can study your favorite + + align:start position:0% +salt so you can study your favorite + + + align:start position:0% +salt so you can study your favorite +small organic molecule whatever you want + + align:start position:0% +small organic molecule whatever you want + + + align:start position:0% +small organic molecule whatever you want +really and so the general workflow is + + align:start position:0% +really and so the general workflow is + + + align:start position:0% +really and so the general workflow is +that you have a source of x-rays that + + align:start position:0% +that you have a source of x-rays that + + + align:start position:0% +that you have a source of x-rays that +can be a synchrotron or a local source + + align:start position:0% +can be a synchrotron or a local source + + + align:start position:0% +can be a synchrotron or a local source +ink runs are much brighter than local + + align:start position:0% +ink runs are much brighter than local + + + align:start position:0% +ink runs are much brighter than local +sources that you shine on your crystal + + align:start position:0% +sources that you shine on your crystal + + + align:start position:0% +sources that you shine on your crystal +and you obtain what is known as a + + align:start position:0% +and you obtain what is known as a + + + align:start position:0% +and you obtain what is known as a +diffraction pattern and so this tells + + align:start position:0% +diffraction pattern and so this tells + + + align:start position:0% +diffraction pattern and so this tells +you how + + align:start position:0% +you how + + + align:start position:0% +you how +the x-rays are in track this tells you + + align:start position:0% +the x-rays are in track this tells you + + + align:start position:0% +the x-rays are in track this tells you +something about how the x-rays are + + align:start position:0% +something about how the x-rays are + + + align:start position:0% +something about how the x-rays are +interacting with the atoms in the + + align:start position:0% +interacting with the atoms in the + + + align:start position:0% +interacting with the atoms in the +material in the crystal and so this will + + align:start position:0% +material in the crystal and so this will + + + align:start position:0% +material in the crystal and so this will +use to be collected on a photographic + + align:start position:0% +use to be collected on a photographic + + + align:start position:0% +use to be collected on a photographic +plate this particular image is on a + + align:start position:0% +plate this particular image is on a + + + align:start position:0% +plate this particular image is on a +photographic plate but now you use + + align:start position:0% +photographic plate but now you use + + + align:start position:0% +photographic plate but now you use +people your CCD sensors it's a lot + + align:start position:0% +people your CCD sensors it's a lot + + + align:start position:0% +people your CCD sensors it's a lot +easier and knowing the different Ella I + + align:start position:0% +easier and knowing the different Ella I + + + align:start position:0% +easier and knowing the different Ella I +also think each of these dots light and + + align:start position:0% +also think each of these dots light and + + + align:start position:0% +also think each of these dots light and +dark on the diffraction pattern is + + align:start position:0% +dark on the diffraction pattern is + + + align:start position:0% +dark on the diffraction pattern is +called a reflection and that contains + + align:start position:0% +called a reflection and that contains + + + align:start position:0% +called a reflection and that contains +some information about the outer + + align:start position:0% +some information about the outer + + + align:start position:0% +some information about the outer +intensity in the crystal structure and + + align:start position:0% +intensity in the crystal structure and + + + align:start position:0% +intensity in the crystal structure and +from your diffraction pattern you can + + align:start position:0% +from your diffraction pattern you can + + + align:start position:0% +from your diffraction pattern you can +then back calculate the electron density + + align:start position:0% +then back calculate the electron density + + + align:start position:0% +then back calculate the electron density +in your crystal structure that gave rise + + align:start position:0% +in your crystal structure that gave rise + + + align:start position:0% +in your crystal structure that gave rise +to this diffraction pattern and the way + + align:start position:0% +to this diffraction pattern and the way + + + align:start position:0% +to this diffraction pattern and the way +you do that is by looking at the + + align:start position:0% +you do that is by looking at the + + + align:start position:0% +you do that is by looking at the +intensity of these reflections and you + + align:start position:0% +intensity of these reflections and you + + + align:start position:0% +intensity of these reflections and you +also need there's also something called + + align:start position:0% +also need there's also something called + + + align:start position:0% +also need there's also something called +phase we need to determine phase and + + align:start position:0% +phase we need to determine phase and + + + align:start position:0% +phase we need to determine phase and +sometimes you will see if in the paper + + align:start position:0% +sometimes you will see if in the paper + + + align:start position:0% +sometimes you will see if in the paper +in the literature you'll see heavy atoms + + align:start position:0% +in the literature you'll see heavy atoms + + + align:start position:0% +in the literature you'll see heavy atoms +being introduced or mercury being + + align:start position:0% +being introduced or mercury being + + + align:start position:0% +being introduced or mercury being +introduced and that's often to determine + + align:start position:0% +introduced and that's often to determine + + + align:start position:0% +introduced and that's often to determine +the phase which is essential for + + align:start position:0% +the phase which is essential for + + + align:start position:0% +the phase which is essential for +calculating the electron density once + + align:start position:0% +calculating the electron density once + + + align:start position:0% +calculating the electron density once +you determine the outer intensity you + + align:start position:0% +you determine the outer intensity you + + + align:start position:0% +you determine the outer intensity you +know what protein you start off with and + + align:start position:0% +know what protein you start off with and + + + align:start position:0% +know what protein you start off with and +so you know what what your protein looks + + align:start position:0% +so you know what what your protein looks + + + align:start position:0% +so you know what what your protein looks +you know the sequence of your protein + + align:start position:0% +you know the sequence of your protein + + + align:start position:0% +you know the sequence of your protein +right and so then you just take your + + align:start position:0% +right and so then you just take your + + + align:start position:0% +right and so then you just take your +after intensity and fit whatever + + align:start position:0% +after intensity and fit whatever + + + align:start position:0% +after intensity and fit whatever +polypeptide chains you have to that and + + align:start position:0% +polypeptide chains you have to that and + + + align:start position:0% +polypeptide chains you have to that and +then usually this is all automated + + align:start position:0% +then usually this is all automated + + + align:start position:0% +then usually this is all automated +nowadays so you press a few buttons and + + align:start position:0% +nowadays so you press a few buttons and + + + align:start position:0% +nowadays so you press a few buttons and +it goes through sort of software does + + align:start position:0% +it goes through sort of software does + + + align:start position:0% +it goes through sort of software does +everything for you but it was much more + + align:start position:0% +everything for you but it was much more + + + align:start position:0% +everything for you but it was much more +challenging early on and even now the + + align:start position:0% +challenging early on and even now the + + + align:start position:0% +challenging early on and even now the +computers will get you up to a certain + + align:start position:0% +computers will get you up to a certain + + + align:start position:0% +computers will get you up to a certain +point and then in the last last stages + + align:start position:0% +point and then in the last last stages + + + align:start position:0% +point and then in the last last stages +of refinement you always want to use + + align:start position:0% +of refinement you always want to use + + + align:start position:0% +of refinement you always want to use +usually people do that by hand any + + align:start position:0% +usually people do that by hand any + + + align:start position:0% +usually people do that by hand any +questions about x-ray crystallography + + align:start position:0% + + + + align:start position:0% + +instead from diffraction pattern but I + + align:start position:0% +instead from diffraction pattern but I + + + align:start position:0% +instead from diffraction pattern but I +mean in organic chemistry in basics one + + align:start position:0% +mean in organic chemistry in basics one + + + align:start position:0% +mean in organic chemistry in basics one +I know that you can from diffraction + + align:start position:0% +I know that you can from diffraction + + + align:start position:0% +I know that you can from diffraction +pattern like you can learn the distance + + align:start position:0% +pattern like you can learn the distance + + + align:start position:0% +pattern like you can learn the distance +between atoms in the the path like in + + align:start position:0% +between atoms in the the path like in + + + align:start position:0% +between atoms in the the path like in +the lattice yes points + + align:start position:0% +the lattice yes points + + + align:start position:0% +the lattice yes points +yes but here in with proteins every + + align:start position:0% +yes but here in with proteins every + + + align:start position:0% +yes but here in with proteins every +point is itself a protein right every + + align:start position:0% + + + + align:start position:0% + +because you're looking at every point in + + align:start position:0% +because you're looking at every point in + + + align:start position:0% +because you're looking at every point in +the lattice is still an atom for if + + align:start position:0% +the lattice is still an atom for if + + + align:start position:0% +the lattice is still an atom for if +you're doing proteins it's just that + + align:start position:0% +you're doing proteins it's just that + + + align:start position:0% +you're doing proteins it's just that +there are a lot more atoms and the + + align:start position:0% +there are a lot more atoms and the + + + align:start position:0% +there are a lot more atoms and the +lattice is a lot bigger which is what + + align:start position:0% +lattice is a lot bigger which is what + + + align:start position:0% +lattice is a lot bigger which is what +makes protein crystallography hard + + align:start position:0% +makes protein crystallography hard + + + align:start position:0% +makes protein crystallography hard +compared to small molecule + + align:start position:0% +compared to small molecule + + + align:start position:0% +compared to small molecule +crystallography so it's harder to solve + + align:start position:0% +crystallography so it's harder to solve + + + align:start position:0% +crystallography so it's harder to solve +a protein crystal structure than it is a + + align:start position:0% +a protein crystal structure than it is a + + + align:start position:0% +a protein crystal structure than it is a +small molecule true structure just + + align:start position:0% +small molecule true structure just + + + align:start position:0% +small molecule true structure just +because there's so many more atoms in + + align:start position:0% +because there's so many more atoms in + + + align:start position:0% +because there's so many more atoms in +your lattice but there but the idea is + + align:start position:0% +your lattice but there but the idea is + + + align:start position:0% +your lattice but there but the idea is +exactly the same as small molecule it's + + align:start position:0% +exactly the same as small molecule it's + + + align:start position:0% +exactly the same as small molecule it's +just a lot harder to do and for more + + align:start position:0% +just a lot harder to do and for more + + + align:start position:0% +just a lot harder to do and for more +information I actually have a resource + + align:start position:0% +information I actually have a resource + + + align:start position:0% +information I actually have a resource +at the end that goes sort of in depth + + align:start position:0% +at the end that goes sort of in depth + + + align:start position:0% +at the end that goes sort of in depth +into the mats math off the process but + + align:start position:0% +into the mats math off the process but + + + align:start position:0% +into the mats math off the process but +just soon briefly this diffraction + + align:start position:0% +just soon briefly this diffraction + + + align:start position:0% +just soon briefly this diffraction +pattern is collected and so what's + + align:start position:0% +pattern is collected and so what's + + + align:start position:0% +pattern is collected and so what's +called reciprocal space and to go from + + align:start position:0% +called reciprocal space and to go from + + + align:start position:0% +called reciprocal space and to go from +this to our intensity you need to do a + + align:start position:0% +this to our intensity you need to do a + + + align:start position:0% +this to our intensity you need to do a +Fourier transform into hilbert space + + align:start position:0% +Fourier transform into hilbert space + + + align:start position:0% +Fourier transform into hilbert space +which is what your intensity is based in + + align:start position:0% +which is what your intensity is based in + + + align:start position:0% +which is what your intensity is based in +but I provide a reference for sort of + + align:start position:0% +but I provide a reference for sort of + + + align:start position:0% +but I provide a reference for sort of +more information on that and so the next + + align:start position:0% +more information on that and so the next + + + align:start position:0% +more information on that and so the next +part of the discussion part of this + + align:start position:0% +part of the discussion part of this + + + align:start position:0% +part of the discussion part of this +recitation would be thinking about some + + align:start position:0% +recitation would be thinking about some + + + align:start position:0% +recitation would be thinking about some +of the limitations of x-ray + + align:start position:0% +of the limitations of x-ray + + + align:start position:0% +of the limitations of x-ray +crystallography so they're large them + + align:start position:0% +crystallography so they're large them + + + align:start position:0% +crystallography so they're large them +but I'll turn to all of you for inputs + + align:start position:0% +but I'll turn to all of you for inputs + + + align:start position:0% +but I'll turn to all of you for inputs +yes absolutely it's really hard to + + align:start position:0% +yes absolutely it's really hard to + + + align:start position:0% +yes absolutely it's really hard to +purify and crystallize proteins it's + + align:start position:0% +purify and crystallize proteins it's + + + align:start position:0% +purify and crystallize proteins it's +really not a trivial task it can take + + align:start position:0% +really not a trivial task it can take + + + align:start position:0% +really not a trivial task it can take +months or even years to do so and + + align:start position:0% +months or even years to do so and + + + align:start position:0% +months or even years to do so and +nowadays you have robots that can set up + + align:start position:0% +nowadays you have robots that can set up + + + align:start position:0% +nowadays you have robots that can set up +reactions under hundreds of different + + align:start position:0% +reactions under hundreds of different + + + align:start position:0% +reactions under hundreds of different +crystallization conditions and it's it's + + align:start position:0% +crystallization conditions and it's it's + + + align:start position:0% +crystallization conditions and it's it's +sort of a black magic sort of art like + + align:start position:0% +sort of a black magic sort of art like + + + align:start position:0% +sort of a black magic sort of art like +you can't it's hard to predict what + + align:start position:0% +you can't it's hard to predict what + + + align:start position:0% +you can't it's hard to predict what +crystallization conditions are going to + + align:start position:0% +crystallization conditions are going to + + + align:start position:0% +crystallization conditions are going to +give you a high quality crystal anything + + align:start position:0% +give you a high quality crystal anything + + + align:start position:0% +give you a high quality crystal anything +else yes + + align:start position:0% + + + + align:start position:0% + +yes absolutely but yeah it's hard to + + align:start position:0% +yes absolutely but yeah it's hard to + + + align:start position:0% +yes absolutely but yeah it's hard to +tell whether the crystal structure that + + align:start position:0% +tell whether the crystal structure that + + + align:start position:0% +tell whether the crystal structure that +you get is depicting what's happening + + align:start position:0% +you get is depicting what's happening + + + align:start position:0% +you get is depicting what's happening +with the protein in vivo and this is + + align:start position:0% +with the protein in vivo and this is + + + align:start position:0% +with the protein in vivo and this is +really this is I mean this is a problem + + align:start position:0% +really this is I mean this is a problem + + + align:start position:0% +really this is I mean this is a problem +that inherent x-ray crystallography rate + + align:start position:0% +that inherent x-ray crystallography rate + + + align:start position:0% +that inherent x-ray crystallography rate +every time you solve it with structure + + align:start position:0% +every time you solve it with structure + + + align:start position:0% +every time you solve it with structure +you don't know whether it's relevant but + + align:start position:0% +you don't know whether it's relevant but + + + align:start position:0% +you don't know whether it's relevant but +I mean usually I think it turned out + + align:start position:0% +I mean usually I think it turned out + + + align:start position:0% +I mean usually I think it turned out +that it's pretty close if not completely + + align:start position:0% +that it's pretty close if not completely + + + align:start position:0% +that it's pretty close if not completely +accurate in solution but sometimes you + + align:start position:0% +accurate in solution but sometimes you + + + align:start position:0% +accurate in solution but sometimes you +do have to be careful about this it's + + align:start position:0% +do have to be careful about this it's + + + align:start position:0% +do have to be careful about this it's +especially challenging for stuff like + + align:start position:0% +especially challenging for stuff like + + + align:start position:0% +especially challenging for stuff like +membrane proteins where you don't really + + align:start position:0% +membrane proteins where you don't really + + + align:start position:0% +membrane proteins where you don't really +know any other ideas + + align:start position:0% + + + + align:start position:0% + +so when proteins are translated do they + + align:start position:0% +so when proteins are translated do they + + + align:start position:0% +so when proteins are translated do they +usually I they usually used just like + + align:start position:0% +usually I they usually used just like + + + align:start position:0% +usually I they usually used just like +that or there's something else happened + + align:start position:0% +that or there's something else happened + + + align:start position:0% +that or there's something else happened +to the proteins in most cells yes + + align:start position:0% +to the proteins in most cells yes + + + align:start position:0% +to the proteins in most cells yes +absolutely posters are made of + + align:start position:0% +absolutely posters are made of + + + align:start position:0% +absolutely posters are made of +modification so most lot of proteins are + + align:start position:0% +modification so most lot of proteins are + + + align:start position:0% +modification so most lot of proteins are +post-translationally modified and so + + align:start position:0% +post-translationally modified and so + + + align:start position:0% +post-translationally modified and so +when you appear when you're making when + + align:start position:0% +when you appear when you're making when + + + align:start position:0% +when you appear when you're making when +you're growing a crystal if your protein + + align:start position:0% +you're growing a crystal if your protein + + + align:start position:0% +you're growing a crystal if your protein +you usually you usually just use a + + align:start position:0% +you usually you usually just use a + + + align:start position:0% +you usually you usually just use a +purified version of your protein so you + + align:start position:0% +purified version of your protein so you + + + align:start position:0% +purified version of your protein so you +can't really calculate and sometimes + + align:start position:0% +can't really calculate and sometimes + + + align:start position:0% +can't really calculate and sometimes +these PTMs are essential for the + + align:start position:0% +these PTMs are essential for the + + + align:start position:0% +these PTMs are essential for the +function of the protein so you're + + align:start position:0% +function of the protein so you're + + + align:start position:0% +function of the protein so you're +missing some part of the picture + + align:start position:0% +missing some part of the picture + + + align:start position:0% +missing some part of the picture +anything else + + align:start position:0% +anything else + + + align:start position:0% +anything else +what about movement can you tell what + + align:start position:0% +what about movement can you tell what + + + align:start position:0% +what about movement can you tell what +proteins are flexible what parts of the + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +yes that is true you can can discern + + align:start position:0% +yes that is true you can can discern + + + align:start position:0% +yes that is true you can can discern +anything about dynamics in flexibility + + align:start position:0% +anything about dynamics in flexibility + + + align:start position:0% +anything about dynamics in flexibility +and the answer is you can tell something + + align:start position:0% +and the answer is you can tell something + + + align:start position:0% +and the answer is you can tell something +you can tell about you can tell + + align:start position:0% +you can tell about you can tell + + + align:start position:0% +you can tell about you can tell +something about the relative motion of + + align:start position:0% +something about the relative motion of + + + align:start position:0% +something about the relative motion of +different parts of the protein with + + align:start position:0% +different parts of the protein with + + + align:start position:0% +different parts of the protein with +respect to each other + + align:start position:0% +respect to each other + + + align:start position:0% +respect to each other +but it's hard to tell something about + + align:start position:0% +but it's hard to tell something about + + + align:start position:0% +but it's hard to tell something about +the absolute motion of these proteins so + + align:start position:0% +the absolute motion of these proteins so + + + align:start position:0% +the absolute motion of these proteins so +you can see say a larger scale of + + align:start position:0% +you can see say a larger scale of + + + align:start position:0% +you can see say a larger scale of +motions right most proteins are living + + align:start position:0% +motions right most proteins are living + + + align:start position:0% +motions right most proteins are living +breathing machines and you really it's + + align:start position:0% +breathing machines and you really it's + + + align:start position:0% +breathing machines and you really it's +hard to capture that in an x-ray + + align:start position:0% +hard to capture that in an x-ray + + + align:start position:0% +hard to capture that in an x-ray +structure all right and one more thing + + align:start position:0% +structure all right and one more thing + + + align:start position:0% +structure all right and one more thing +so is there any element that you cannot + + align:start position:0% +so is there any element that you cannot + + + align:start position:0% +so is there any element that you cannot +detect in extra crystallography very + + align:start position:0% +detect in extra crystallography very + + + align:start position:0% +detect in extra crystallography very +well this has to do with the way so in + + align:start position:0% +well this has to do with the way so in + + + align:start position:0% +well this has to do with the way so in +x-ray crystallography you're studying + + align:start position:0% +x-ray crystallography you're studying + + + align:start position:0% +x-ray crystallography you're studying +interactions of x-rays with without + + align:start position:0% +interactions of x-rays with without + + + align:start position:0% +interactions of x-rays with without +Tron's right so does anybody know which + + align:start position:0% + + + + align:start position:0% + +protons have one out Tron and so they're + + align:start position:0% +protons have one out Tron and so they're + + + align:start position:0% +protons have one out Tron and so they're +x-ray signal so-called is really weak + + align:start position:0% +x-ray signal so-called is really weak + + + align:start position:0% +x-ray signal so-called is really weak +really really weak and so you can't + + align:start position:0% +really really weak and so you can't + + + align:start position:0% +really really weak and so you can't +really see protons with x-ray + + align:start position:0% +really see protons with x-ray + + + align:start position:0% +really see protons with x-ray +crystallography until you can really + + align:start position:0% +crystallography until you can really + + + align:start position:0% +crystallography until you can really +study hydrogen's or hydrogen bonds and + + align:start position:0% +study hydrogen's or hydrogen bonds and + + + align:start position:0% +study hydrogen's or hydrogen bonds and +if you look at a structure of proteins + + align:start position:0% +if you look at a structure of proteins + + + align:start position:0% +if you look at a structure of proteins +that has hydrogens in it those hydrogens + + align:start position:0% +that has hydrogens in it those hydrogens + + + align:start position:0% +that has hydrogens in it those hydrogens +were put there as a result of an average + + align:start position:0% +were put there as a result of an average + + + align:start position:0% +were put there as a result of an average +bond length their typical bond length + + align:start position:0% +bond length their typical bond length + + + align:start position:0% +bond length their typical bond length +calculation so it's not actually + + align:start position:0% +calculation so it's not actually + + + align:start position:0% +calculation so it's not actually +experimentally determined you can use + + align:start position:0% +experimentally determined you can use + + + align:start position:0% +experimentally determined you can use +Neutron diffraction to get around this + + align:start position:0% +Neutron diffraction to get around this + + + align:start position:0% +Neutron diffraction to get around this +but Neutron diffraction is hard to do + + align:start position:0% +but Neutron diffraction is hard to do + + + align:start position:0% +but Neutron diffraction is hard to do +because you need to grow very large + + align:start position:0% +because you need to grow very large + + + align:start position:0% +because you need to grow very large +crystals to study and I think there are + + align:start position:0% +crystals to study and I think there are + + + align:start position:0% +crystals to study and I think there are +about 80 + + align:start position:0% +about 80 + + + align:start position:0% +about 80 +I think neutron around 100 Neutron + + align:start position:0% +I think neutron around 100 Neutron + + + align:start position:0% +I think neutron around 100 Neutron +structures in the PDB so far but for + + align:start position:0% +structures in the PDB so far but for + + + align:start position:0% +structures in the PDB so far but for +small molecules neutron is much more + + align:start position:0% +small molecules neutron is much more + + + align:start position:0% +small molecules neutron is much more +accessible Neutron diffraction and so + + align:start position:0% +accessible Neutron diffraction and so + + + align:start position:0% +accessible Neutron diffraction and so +the idea is the same as x-ray + + align:start position:0% +the idea is the same as x-ray + + + align:start position:0% +the idea is the same as x-ray +lithography except for you're using + + align:start position:0% +lithography except for you're using + + + align:start position:0% +lithography except for you're using +neutrons all right and the final point + + align:start position:0% +neutrons all right and the final point + + + align:start position:0% +neutrons all right and the final point +is that one structure only tells you + + align:start position:0% +is that one structure only tells you + + + align:start position:0% +is that one structure only tells you +part of the story again and this is + + align:start position:0% +part of the story again and this is + + + align:start position:0% +part of the story again and this is +emphasizing the fact that one structure + + align:start position:0% +emphasizing the fact that one structure + + + align:start position:0% +emphasizing the fact that one structure +is just a snapshot off the protein at a + + align:start position:0% +is just a snapshot off the protein at a + + + align:start position:0% +is just a snapshot off the protein at a +certain time and you want to correctly + + align:start position:0% +certain time and you want to correctly + + + align:start position:0% +certain time and you want to correctly +interpret your data and learn something + + align:start position:0% +interpret your data and learn something + + + align:start position:0% +interpret your data and learn something +more about the protein you often have to + + align:start position:0% +more about the protein you often have to + + + align:start position:0% +more about the protein you often have to +you have to use complementary + + align:start position:0% +you have to use complementary + + + align:start position:0% +you have to use complementary +biophysical biochemical techniques are + + align:start position:0% +biophysical biochemical techniques are + + + align:start position:0% +biophysical biochemical techniques are +there any questions at this point so the + + align:start position:0% +there any questions at this point so the + + + align:start position:0% +there any questions at this point so the +last part of the talk is on how to + + align:start position:0% +last part of the talk is on how to + + + align:start position:0% +last part of the talk is on how to +assess the quality of structures in the + + align:start position:0% +assess the quality of structures in the + + + align:start position:0% +assess the quality of structures in the +PDB there are large structures and you + + align:start position:0% +PDB there are large structures and you + + + align:start position:0% +PDB there are large structures and you +want to be able to know whether the + + align:start position:0% +want to be able to know whether the + + + align:start position:0% +want to be able to know whether the +model is presented to you is act is + + align:start position:0% +model is presented to you is act is + + + align:start position:0% +model is presented to you is act is +actually accurate + + align:start position:0% +actually accurate + + + align:start position:0% +actually accurate +accurately reflects the data that was + + align:start position:0% +accurately reflects the data that was + + + align:start position:0% +accurately reflects the data that was +collected and so the first point is what + + align:start position:0% +collected and so the first point is what + + + align:start position:0% +collected and so the first point is what +is the resolution of a structure and so + + align:start position:0% +is the resolution of a structure and so + + + align:start position:0% +is the resolution of a structure and so +the take-home message at a lower number + + align:start position:0% +the take-home message at a lower number + + + align:start position:0% +the take-home message at a lower number +means a greater resolution and the + + align:start position:0% +means a greater resolution and the + + + align:start position:0% +means a greater resolution and the +resolution actually here is referring to + + align:start position:0% +resolution actually here is referring to + + + align:start position:0% +resolution actually here is referring to +the distances between the atoms in the + + align:start position:0% +the distances between the atoms in the + + + align:start position:0% +the distances between the atoms in the +plane and so that's where the s coming + + align:start position:0% +plane and so that's where the s coming + + + align:start position:0% +plane and so that's where the s coming +from so that's why you if you have a low + + align:start position:0% +from so that's why you if you have a low + + + align:start position:0% +from so that's why you if you have a low +resolution that means you can resolve + + align:start position:0% +resolution that means you can resolve + + + align:start position:0% +resolution that means you can resolve +atoms one angstrom resolution means that + + align:start position:0% +atoms one angstrom resolution means that + + + align:start position:0% +atoms one angstrom resolution means that +you can resolve atoms that are one + + align:start position:0% +you can resolve atoms that are one + + + align:start position:0% +you can resolve atoms that are one +absolute apart on parallel planes but + + align:start position:0% +absolute apart on parallel planes but + + + align:start position:0% +absolute apart on parallel planes but +the take-home message is for at a 1 + + align:start position:0% +the take-home message is for at a 1 + + + align:start position:0% +the take-home message is for at a 1 +angstrom resolution you can see + + align:start position:0% +angstrom resolution you can see + + + align:start position:0% +angstrom resolution you can see +individual atoms and you can discern the + + align:start position:0% +individual atoms and you can discern the + + + align:start position:0% +individual atoms and you can discern the +identities of those atoms by looking at + + align:start position:0% +identities of those atoms by looking at + + + align:start position:0% +identities of those atoms by looking at +their electron density but if you come + + align:start position:0% +their electron density but if you come + + + align:start position:0% +their electron density but if you come +down to a 4 angstrom structure you see + + align:start position:0% +down to a 4 angstrom structure you see + + + align:start position:0% +down to a 4 angstrom structure you see +the benzene ring doesn't really have a + + align:start position:0% +the benzene ring doesn't really have a + + + align:start position:0% +the benzene ring doesn't really have a +clearly defined that tron density and + + align:start position:0% +clearly defined that tron density and + + + align:start position:0% +clearly defined that tron density and +there's no hole in the center but if you + + align:start position:0% +there's no hole in the center but if you + + + align:start position:0% +there's no hole in the center but if you +look at the one angstrom structure you + + align:start position:0% +look at the one angstrom structure you + + + align:start position:0% +look at the one angstrom structure you +can see that there's even a hole in them + + align:start position:0% +can see that there's even a hole in them + + + align:start position:0% +can see that there's even a hole in them +in the benzene ring to account for an + + align:start position:0% +in the benzene ring to account for an + + + align:start position:0% +in the benzene ring to account for an +oil trend entry there and then if you + + align:start position:0% +oil trend entry there and then if you + + + align:start position:0% +oil trend entry there and then if you +look at so this is these are the data + + align:start position:0% +look at so this is these are the data + + + align:start position:0% +look at so this is these are the data +statistics so this is just pulled from + + align:start position:0% +statistics so this is just pulled from + + + align:start position:0% +statistics so this is just pulled from +PDB off to jf5 so this is a PDB ID for + + align:start position:0% +PDB off to jf5 so this is a PDB ID for + + + align:start position:0% +PDB off to jf5 so this is a PDB ID for +Diavik Witten and we'll be looking at + + align:start position:0% +Diavik Witten and we'll be looking at + + + align:start position:0% +Diavik Witten and we'll be looking at +this structure later in the worksheet + + align:start position:0% +this structure later in the worksheet + + + align:start position:0% +this structure later in the worksheet +the resolution tells you of course about + + align:start position:0% +the resolution tells you of course about + + + align:start position:0% +the resolution tells you of course about +the resolution of the crystal structure + + align:start position:0% +the resolution of the crystal structure + + + align:start position:0% +the resolution of the crystal structure +and so this is in this case it's one + + align:start position:0% +and so this is in this case it's one + + + align:start position:0% +and so this is in this case it's one +point nine five angstroms or two + + align:start position:0% +point nine five angstroms or two + + + align:start position:0% +point nine five angstroms or two +angstroms and so that's pretty high + + align:start position:0% +angstroms and so that's pretty high + + + align:start position:0% +angstroms and so that's pretty high +resolution reflections our reflections + + align:start position:0% +resolution reflections our reflections + + + align:start position:0% +resolution reflections our reflections +are each of those points in the + + align:start position:0% +are each of those points in the + + + align:start position:0% +are each of those points in the +diffraction pattern that you collect and + + align:start position:0% +diffraction pattern that you collect and + + + align:start position:0% +diffraction pattern that you collect and +a unique reflection refers to the fact + + align:start position:0% +a unique reflection refers to the fact + + + align:start position:0% +a unique reflection refers to the fact +that you've only collected at once + + align:start position:0% +that you've only collected at once + + + align:start position:0% +that you've only collected at once +so usually when you when you collect + + align:start position:0% +so usually when you when you collect + + + align:start position:0% +so usually when you when you collect +diffraction patterns you collect you put + + align:start position:0% +diffraction patterns you collect you put + + + align:start position:0% +diffraction patterns you collect you put +your protein at a certain certain + + align:start position:0% +your protein at a certain certain + + + align:start position:0% +your protein at a certain certain +orientation respect with respect to the + + align:start position:0% +orientation respect with respect to the + + + align:start position:0% +orientation respect with respect to the +x-ray beam and then you collect + + align:start position:0% +x-ray beam and then you collect + + + align:start position:0% +x-ray beam and then you collect +infraction pattern and then you rotate + + align:start position:0% +infraction pattern and then you rotate + + + align:start position:0% +infraction pattern and then you rotate +to your crystal a whole bunch of times + + align:start position:0% +to your crystal a whole bunch of times + + + align:start position:0% +to your crystal a whole bunch of times +and you collect a whole bunch of + + align:start position:0% +and you collect a whole bunch of + + + align:start position:0% +and you collect a whole bunch of +different diffraction patterns and then + + align:start position:0% +different diffraction patterns and then + + + align:start position:0% +different diffraction patterns and then +you superimpose all of those together to + + align:start position:0% +you superimpose all of those together to + + + align:start position:0% +you superimpose all of those together to +get the master diffraction pattern + + align:start position:0% +get the master diffraction pattern + + + align:start position:0% +get the master diffraction pattern +redundancy refers to the facts of how + + align:start position:0% +redundancy refers to the facts of how + + + align:start position:0% +redundancy refers to the facts of how +often each reflection was observed and + + align:start position:0% +often each reflection was observed and + + + align:start position:0% +often each reflection was observed and +so this is just signal averaging the + + align:start position:0% +so this is just signal averaging the + + + align:start position:0% +so this is just signal averaging the +more redundancy you have the greater + + align:start position:0% +more redundancy you have the greater + + + align:start position:0% +more redundancy you have the greater +number of times you observe that + + align:start position:0% +number of times you observe that + + + align:start position:0% +number of times you observe that +particular reflection completed nough + + align:start position:0% +particular reflection completed nough + + + align:start position:0% +particular reflection completed nough +stuffers - how many of the data points + + align:start position:0% +stuffers - how many of the data points + + + align:start position:0% +stuffers - how many of the data points +were actually measured and so this is + + align:start position:0% +were actually measured and so this is + + + align:start position:0% +were actually measured and so this is +when you created your model you can back + + align:start position:0% +when you created your model you can back + + + align:start position:0% +when you created your model you can back +calculate your diffraction pattern + + align:start position:0% +calculate your diffraction pattern + + + align:start position:0% +calculate your diffraction pattern +and then you see how many of this those + + align:start position:0% +and then you see how many of this those + + + align:start position:0% +and then you see how many of this those +reflections were experimentally observed + + align:start position:0% +reflections were experimentally observed + + + align:start position:0% +reflections were experimentally observed +in your dataset and so for this usually + + align:start position:0% +in your dataset and so for this usually + + + align:start position:0% +in your dataset and so for this usually +one I supposed 100% and anything above + + align:start position:0% +one I supposed 100% and anything above + + + align:start position:0% +one I supposed 100% and anything above +95% is considered fairly good our merge + + align:start position:0% +95% is considered fairly good our merge + + + align:start position:0% +95% is considered fairly good our merge +is is an indicator of how consistent + + align:start position:0% +is is an indicator of how consistent + + + align:start position:0% +is is an indicator of how consistent +measurements are so this is a measure of + + align:start position:0% +measurements are so this is a measure of + + + align:start position:0% +measurements are so this is a measure of +what the DBA what the difference between + + align:start position:0% +what the DBA what the difference between + + + align:start position:0% +what the DBA what the difference between +different measurements for the same + + align:start position:0% +different measurements for the same + + + align:start position:0% +different measurements for the same +reflection are so if you collect the if + + align:start position:0% +reflection are so if you collect the if + + + align:start position:0% +reflection are so if you collect the if +you look at the intensity for for the + + align:start position:0% +you look at the intensity for for the + + + align:start position:0% +you look at the intensity for for the +same reflection a different number of + + align:start position:0% +same reflection a different number of + + + align:start position:0% +same reflection a different number of +times is saying the standard deviation + + align:start position:0% +times is saying the standard deviation + + + align:start position:0% +times is saying the standard deviation +of that and so you want lower as lower + + align:start position:0% +of that and so you want lower as lower + + + align:start position:0% +of that and so you want lower as lower +number as possible so it usually wanted + + align:start position:0% +number as possible so it usually wanted + + + align:start position:0% +number as possible so it usually wanted +to be about point about one tenth of the + + align:start position:0% +to be about point about one tenth of the + + + align:start position:0% +to be about point about one tenth of the +resolution of your crystal structure + + align:start position:0% +resolution of your crystal structure + + + align:start position:0% +resolution of your crystal structure +which is point to act was in this case I + + align:start position:0% +which is point to act was in this case I + + + align:start position:0% +which is point to act was in this case I +forgot to mention this but the values in + + align:start position:0% +forgot to mention this but the values in + + + align:start position:0% +forgot to mention this but the values in +parentheses are for a high resolution + + align:start position:0% +parentheses are for a high resolution + + + align:start position:0% +parentheses are for a high resolution +bin so this is just a certain subset of + + align:start position:0% +bin so this is just a certain subset of + + + align:start position:0% +bin so this is just a certain subset of +this data set that's considered to be + + align:start position:0% +this data set that's considered to be + + + align:start position:0% +this data set that's considered to be +higher quality than the original dataset + + align:start position:0% +higher quality than the original dataset + + + align:start position:0% +higher quality than the original dataset +and that's actually coming from this + + align:start position:0% +and that's actually coming from this + + + align:start position:0% +and that's actually coming from this +value which is signal intense signal or + + align:start position:0% +value which is signal intense signal or + + + align:start position:0% +value which is signal intense signal or +signal intensity over Sigma signal + + align:start position:0% +signal intensity over Sigma signal + + + align:start position:0% +signal intensity over Sigma signal +intensity and that's a measure of the + + align:start position:0% +intensity and that's a measure of the + + + align:start position:0% +intensity and that's a measure of the +signal-to-noise ratio so you want a + + align:start position:0% +signal-to-noise ratio so you want a + + + align:start position:0% +signal-to-noise ratio so you want a +higher signal-to-noise ratio is better + + align:start position:0% +higher signal-to-noise ratio is better + + + align:start position:0% +higher signal-to-noise ratio is better +and this is fairly good and the higher + + align:start position:0% +and this is fairly good and the higher + + + align:start position:0% +and this is fairly good and the higher +the better and cutoff is that two for + + align:start position:0% +the better and cutoff is that two for + + + align:start position:0% +the better and cutoff is that two for +the high resolution bin off your data + + align:start position:0% +the high resolution bin off your data + + + align:start position:0% +the high resolution bin off your data +points all right so this is just the raw + + align:start position:0% +points all right so this is just the raw + + + align:start position:0% +points all right so this is just the raw +data and then the refinement statistics + + align:start position:0% +data and then the refinement statistics + + + align:start position:0% +data and then the refinement statistics +tell you something about your refinement + + align:start position:0% +tell you something about your refinement + + + align:start position:0% +tell you something about your refinement +process that gave you the crystal + + align:start position:0% +process that gave you the crystal + + + align:start position:0% +process that gave you the crystal +structure which you calculated so our + + align:start position:0% +structure which you calculated so our + + + align:start position:0% +structure which you calculated so our +crystallization which is also our crisp + + align:start position:0% +crystallization which is also our crisp + + + align:start position:0% +crystallization which is also our crisp +which is also call our work and also + + align:start position:0% +which is also call our work and also + + + align:start position:0% +which is also call our work and also +Carl called the R factor that tells you + + align:start position:0% +Carl called the R factor that tells you + + + align:start position:0% +Carl called the R factor that tells you +how well your data and your your model + + align:start position:0% +how well your data and your your model + + + align:start position:0% +how well your data and your your model +in your data match and so this is where + + align:start position:0% +in your data match and so this is where + + + align:start position:0% +in your data match and so this is where +you calculate the difference in the + + align:start position:0% +you calculate the difference in the + + + align:start position:0% +you calculate the difference in the +diffraction patterns between what you + + align:start position:0% +diffraction patterns between what you + + + align:start position:0% +diffraction patterns between what you +observed and what with you in what do + + align:start position:0% +observed and what with you in what do + + + align:start position:0% +observed and what with you in what do +you experiment observe and what you + + align:start position:0% +you experiment observe and what you + + + align:start position:0% +you experiment observe and what you +calculated using the model of electron + + align:start position:0% +calculated using the model of electron + + + align:start position:0% +calculated using the model of electron +density our free tells you how well your + + align:start position:0% +density our free tells you how well your + + + align:start position:0% +density our free tells you how well your +model and data match been corrected for + + align:start position:0% +model and data match been corrected for + + + align:start position:0% +model and data match been corrected for +overfitting so the idea behind this is + + align:start position:0% +overfitting so the idea behind this is + + + align:start position:0% +overfitting so the idea behind this is +that when you collect when you collect + + align:start position:0% +that when you collect when you collect + + + align:start position:0% +that when you collect when you collect +your data set you put aside about 5% of + + align:start position:0% +your data set you put aside about 5% of + + + align:start position:0% +your data set you put aside about 5% of +the reflections that you observe in that + + align:start position:0% +the reflections that you observe in that + + + align:start position:0% +the reflections that you observe in that +data set + + align:start position:0% +data set + + + align:start position:0% +data set +to prevent over-fitting and then when + + align:start position:0% +to prevent over-fitting and then when + + + align:start position:0% +to prevent over-fitting and then when +you've created your model you go back + + align:start position:0% +you've created your model you go back + + + align:start position:0% +you've created your model you go back +and see how well those five percent of + + align:start position:0% +and see how well those five percent of + + + align:start position:0% +and see how well those five percent of +data points fit the model that you've + + align:start position:0% +data points fit the model that you've + + + align:start position:0% +data points fit the model that you've +come up with and if they fit well that + + align:start position:0% +come up with and if they fit well that + + + align:start position:0% +come up with and if they fit well that +means you've accurately predicted your + + align:start position:0% +means you've accurately predicted your + + + align:start position:0% +means you've accurately predicted your +crystal structure using the data that + + align:start position:0% +crystal structure using the data that + + + align:start position:0% +crystal structure using the data that +you have but if you don't fit well that + + align:start position:0% +you have but if you don't fit well that + + + align:start position:0% +you have but if you don't fit well that +means you've just fit whatever data + + align:start position:0% +means you've just fit whatever data + + + align:start position:0% +means you've just fit whatever data +points you have to some model right you + + align:start position:0% +points you have to some model right you + + + align:start position:0% +points you have to some model right you +use a bunch of data point and you fit it + + align:start position:0% +use a bunch of data point and you fit it + + + align:start position:0% +use a bunch of data point and you fit it +to some model but that doesn't actually + + align:start position:0% +to some model but that doesn't actually + + + align:start position:0% +to some model but that doesn't actually +that's not actually accurate to the + + align:start position:0% +that's not actually accurate to the + + + align:start position:0% +that's not actually accurate to the +protein structure that you determine and + + align:start position:0% +protein structure that you determine and + + + align:start position:0% +protein structure that you determine and +so for this you want it to be about + + align:start position:0% +so for this you want it to be about + + + align:start position:0% +so for this you want it to be about +one-tenth of a resolution that's also + + align:start position:0% +one-tenth of a resolution that's also + + + align:start position:0% +one-tenth of a resolution that's also +true for our crest but then the other + + align:start position:0% +true for our crest but then the other + + + align:start position:0% +true for our crest but then the other +key point is that it should be very + + align:start position:0% +key point is that it should be very + + + align:start position:0% +key point is that it should be very +close to the R Chris we're just telling + + align:start position:0% +close to the R Chris we're just telling + + + align:start position:0% +close to the R Chris we're just telling +you that it's it's random error or it's + + align:start position:0% +you that it's it's random error or it's + + + align:start position:0% +you that it's it's random error or it's +a quality of a data set that's causing + + align:start position:0% +a quality of a data set that's causing + + + align:start position:0% +a quality of a data set that's causing +this and not some not some over + + align:start position:0% +this and not some not some over + + + align:start position:0% +this and not some not some over +refinement that you've done during the + + align:start position:0% +refinement that you've done during the + + + align:start position:0% +refinement that you've done during the +refinement process B factor tells you + + align:start position:0% +refinement process B factor tells you + + + align:start position:0% +refinement process B factor tells you +about how mobile atoms are in the + + align:start position:0% +about how mobile atoms are in the + + + align:start position:0% +about how mobile atoms are in the +crystal lattice and this is something + + align:start position:0% +crystal lattice and this is something + + + align:start position:0% +crystal lattice and this is something +that's not it's not particularly useful + + align:start position:0% +that's not it's not particularly useful + + + align:start position:0% +that's not it's not particularly useful +if you look at the bulb out statistic + + align:start position:0% +if you look at the bulb out statistic + + + align:start position:0% +if you look at the bulb out statistic +but if you need to it's important to + + align:start position:0% +but if you need to it's important to + + + align:start position:0% +but if you need to it's important to +evaluate this by residue and so if you + + align:start position:0% +evaluate this by residue and so if you + + + align:start position:0% +evaluate this by residue and so if you +look at amino acids in the loops or + + align:start position:0% +look at amino acids in the loops or + + + align:start position:0% +look at amino acids in the loops or +proteins you'll find that they have a + + align:start position:0% +proteins you'll find that they have a + + + align:start position:0% +proteins you'll find that they have a +higher B factor usually meaning that + + align:start position:0% +higher B factor usually meaning that + + + align:start position:0% +higher B factor usually meaning that +they're more mobile and so you can often + + align:start position:0% +they're more mobile and so you can often + + + align:start position:0% +they're more mobile and so you can often +tell what residues are important for + + align:start position:0% +tell what residues are important for + + + align:start position:0% +tell what residues are important for +function by looking at the B factor it + + align:start position:0% +function by looking at the B factor it + + + align:start position:0% +function by looking at the B factor it +also I mean we factors coming from + + align:start position:0% +also I mean we factors coming from + + + align:start position:0% +also I mean we factors coming from +there's inherent vibration vibration + + align:start position:0% +there's inherent vibration vibration + + + align:start position:0% +there's inherent vibration vibration +emotions in all atoms right so there + + align:start position:0% +emotions in all atoms right so there + + + align:start position:0% +emotions in all atoms right so there +will be a B Factory at any temperature + + align:start position:0% +will be a B Factory at any temperature + + + align:start position:0% +will be a B Factory at any temperature +greater than zero but it also does tell + + align:start position:0% +greater than zero but it also does tell + + + align:start position:0% +greater than zero but it also does tell +you a little bit about the disorder in + + align:start position:0% +you a little bit about the disorder in + + + align:start position:0% +you a little bit about the disorder in +protein structures and the B factor of + + align:start position:0% +protein structures and the B factor of + + + align:start position:0% +protein structures and the B factor of +water is often included just so that + + align:start position:0% +water is often included just so that + + + align:start position:0% +water is often included just so that +people who are looking at the crew + + align:start position:0% +people who are looking at the crew + + + align:start position:0% +people who are looking at the crew +structure afterwards can decide whether + + align:start position:0% +structure afterwards can decide whether + + + align:start position:0% +structure afterwards can decide whether +that what is really there or really was + + align:start position:0% +that what is really there or really was + + + align:start position:0% +that what is really there or really was +part of the electron density or whether + + align:start position:0% +part of the electron density or whether + + + align:start position:0% +part of the electron density or whether +it's just an artifact of or refinement + + align:start position:0% +it's just an artifact of or refinement + + + align:start position:0% +it's just an artifact of or refinement +or something like that and then the + + align:start position:0% +or something like that and then the + + + align:start position:0% +or something like that and then the +final statistic that you can look at is + + align:start position:0% +final statistic that you can look at is + + + align:start position:0% +final statistic that you can look at is +at the rmsd from ideal geometry so the + + align:start position:0% +at the rmsd from ideal geometry so the + + + align:start position:0% +at the rmsd from ideal geometry so the +geometries of these bonds and angles are + + align:start position:0% +geometries of these bonds and angles are + + + align:start position:0% +geometries of these bonds and angles are +usually well known and so if you compare + + align:start position:0% +usually well known and so if you compare + + + align:start position:0% +usually well known and so if you compare +the results from your structure to the + + align:start position:0% +the results from your structure to the + + + align:start position:0% +the results from your structure to the +knowns a Stewart chemistry you will find + + align:start position:0% +knowns a Stewart chemistry you will find + + + align:start position:0% +knowns a Stewart chemistry you will find +that this is actually just at the + + align:start position:0% +that this is actually just at the + + + align:start position:0% +that this is actually just at the +threshold of the cutoff for what's + + align:start position:0% +threshold of the cutoff for what's + + + align:start position:0% +threshold of the cutoff for what's +considered good so 0.015 angstroms this + + align:start position:0% +considered good so 0.015 angstroms this + + + align:start position:0% +considered good so 0.015 angstroms this +is a standard deviation of bond lengths + + align:start position:0% +is a standard deviation of bond lengths + + + align:start position:0% +is a standard deviation of bond lengths +your model versus what is well what is + + align:start position:0% +your model versus what is well what is + + + align:start position:0% +your model versus what is well what is +already known and to 0.015 angstroms is + + align:start position:0% +already known and to 0.015 angstroms is + + + align:start position:0% +already known and to 0.015 angstroms is +is just about the cutoff that's + + align:start position:0% +is just about the cutoff that's + + + align:start position:0% +is just about the cutoff that's +considered good for this for extra + + align:start position:0% +considered good for this for extra + + + align:start position:0% +considered good for this for extra +structures and it's same for bond angles + + align:start position:0% +structures and it's same for bond angles + + + align:start position:0% +structures and it's same for bond angles +1.5 degrees is considered sort of the + + align:start position:0% +1.5 degrees is considered sort of the + + + align:start position:0% +1.5 degrees is considered sort of the +threshold of what is conceptual and you + + align:start position:0% +threshold of what is conceptual and you + + + align:start position:0% +threshold of what is conceptual and you +can also look at Ramachandran statistics + + align:start position:0% +can also look at Ramachandran statistics + + + align:start position:0% +can also look at Ramachandran statistics +so this is looking at five side backbone + + align:start position:0% +so this is looking at five side backbone + + + align:start position:0% +so this is looking at five side backbone +angles to tell you if there are any + + align:start position:0% +angles to tell you if there are any + + + align:start position:0% +angles to tell you if there are any +steric clashes say between between four + + align:start position:0% +steric clashes say between between four + + + align:start position:0% +steric clashes say between between four +side chains that should really shouldn't + + align:start position:0% +side chains that should really shouldn't + + + align:start position:0% +side chains that should really shouldn't +be there and you can if you do have + + align:start position:0% +be there and you can if you do have + + + align:start position:0% +be there and you can if you do have +steric clash nowadays you have to report + + align:start position:0% +steric clash nowadays you have to report + + + align:start position:0% +steric clash nowadays you have to report +it to PDB the only exception is for + + align:start position:0% +it to PDB the only exception is for + + + align:start position:0% +it to PDB the only exception is for +glycine which doesn't have a side chain + + align:start position:0% +glycine which doesn't have a side chain + + + align:start position:0% +glycine which doesn't have a side chain +and so it can adopt a strange fire angle + + align:start position:0% +and so it can adopt a strange fire angle + + + align:start position:0% +and so it can adopt a strange fire angle +that's outside the Ramachandran plot any + + align:start position:0% +that's outside the Ramachandran plot any + + + align:start position:0% +that's outside the Ramachandran plot any +questions about on this anything else + + align:start position:0% +questions about on this anything else + + + align:start position:0% +questions about on this anything else +about x-ray crystallography so this + + align:start position:0% +about x-ray crystallography so this + + + align:start position:0% +about x-ray crystallography so this +brings us to the end of the talk and + + align:start position:0% +brings us to the end of the talk and + + + align:start position:0% +brings us to the end of the talk and +this is sort of a nice a resource that I + + align:start position:0% +this is sort of a nice a resource that I + + + align:start position:0% +this is sort of a nice a resource that I +found that has more information about + + align:start position:0% +found that has more information about + + + align:start position:0% +found that has more information about +exa crystallography and the math behind + + align:start position:0% +exa crystallography and the math behind + + + align:start position:0% +exa crystallography and the math behind +x-ray crystallography and more of the + + align:start position:0% +x-ray crystallography and more of the + + + align:start position:0% +x-ray crystallography and more of the +theory behind it but again I want to + + align:start position:0% +theory behind it but again I want to + + + align:start position:0% +theory behind it but again I want to +emphasize that today it's a very + + align:start position:0% +emphasize that today it's a very + + + align:start position:0% +emphasize that today it's a very +automated process is that you click a + + align:start position:0% +automated process is that you click a + + + align:start position:0% +automated process is that you click a +few buttons and anybody can do it + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/tOsdeaYDCMk.txt b/tOsdeaYDCMk.txt new file mode 100644 index 0000000000000000000000000000000000000000..4c94f9737d6212f54552af249a55634919680172 --- /dev/null +++ b/tOsdeaYDCMk.txt @@ -0,0 +1,2219 @@ +align:start position:0% + +now the standard thing you do with a + + align:start position:0% +now the standard thing you do with a + + + align:start position:0% +now the standard thing you do with a +recursive data type in programming is + + align:start position:0% +recursive data type in programming is + + + align:start position:0% +recursive data type in programming is +you define recursive procedures on them + + align:start position:0% +you define recursive procedures on them + + + align:start position:0% +you define recursive procedures on them +so let's look at how that works I'm + + align:start position:0% +so let's look at how that works I'm + + + align:start position:0% +so let's look at how that works I'm +going to define a function f on a + + align:start position:0% +going to define a function f on a + + + align:start position:0% +going to define a function f on a +recursively defined data type r the way + + align:start position:0% +recursively defined data type r the way + + + align:start position:0% +recursively defined data type r the way +I'm going to do it is I'm going to + + align:start position:0% +I'm going to do it is I'm going to + + + align:start position:0% +I'm going to do it is I'm going to +define f of b explicitly in terms of b + + align:start position:0% +define f of b explicitly in terms of b + + + align:start position:0% +define f of b explicitly in terms of b +and operations that are already + + align:start position:0% +and operations that are already + + + align:start position:0% +and operations that are already +understood for all of the base cases of + + align:start position:0% +understood for all of the base cases of + + + align:start position:0% +understood for all of the base cases of +B in R and then I'm going to define F of + + align:start position:0% +B in R and then I'm going to define F of + + + align:start position:0% +B in R and then I'm going to define F of +a constructor applied to X in terms of X + + align:start position:0% +a constructor applied to X in terms of X + + + align:start position:0% +a constructor applied to X in terms of X +and f of X and if I keep to that + + align:start position:0% +and f of X and if I keep to that + + + align:start position:0% +and f of X and if I keep to that +structure that gives me a recursive + + align:start position:0% +structure that gives me a recursive + + + align:start position:0% +structure that gives me a recursive +definition of the function f on the + + align:start position:0% +definition of the function f on the + + + align:start position:0% +definition of the function f on the +recursively defined data set R let's + + align:start position:0% +recursively defined data set R let's + + + align:start position:0% +recursively defined data set R let's +look at an example to make this recipe + + align:start position:0% +look at an example to make this recipe + + + align:start position:0% +look at an example to make this recipe +explicit and clearer let's think about a + + align:start position:0% +explicit and clearer let's think about a + + + align:start position:0% +explicit and clearer let's think about a +recursive function on the set of matched + + align:start position:0% +recursive function on the set of matched + + + align:start position:0% +recursive function on the set of matched +brackets this is a some one interesting + + align:start position:0% +brackets this is a some one interesting + + + align:start position:0% +brackets this is a some one interesting +one let's define the depth of a string + + align:start position:0% +one let's define the depth of a string + + + align:start position:0% +one let's define the depth of a string +as follows and the ideas that's how + + align:start position:0% +as follows and the ideas that's how + + + align:start position:0% +as follows and the ideas that's how +deeply nested are they successive pairs + + align:start position:0% +deeply nested are they successive pairs + + + align:start position:0% +deeply nested are they successive pairs +of left and right brackets well the + + align:start position:0% +of left and right brackets well the + + + align:start position:0% +of left and right brackets well the +depth of the empty string is 0 got to + + align:start position:0% +depth of the empty string is 0 got to + + + align:start position:0% +depth of the empty string is 0 got to +start somewhere + + align:start position:0% +start somewhere + + + align:start position:0% +start somewhere +and it's got enough no brackets we'll + + align:start position:0% +and it's got enough no brackets we'll + + + align:start position:0% +and it's got enough no brackets we'll +call it f 0 now what about the depth of + + align:start position:0% +call it f 0 now what about the depth of + + + align:start position:0% +call it f 0 now what about the depth of +the constructor putting brackets around + + align:start position:0% +the constructor putting brackets around + + + align:start position:0% +the constructor putting brackets around +s and then following it by Tay well + + align:start position:0% +s and then following it by Tay well + + + align:start position:0% +s and then following it by Tay well +putting brackets around s gives you a + + align:start position:0% +putting brackets around s gives you a + + + align:start position:0% +putting brackets around s gives you a +string that's one deeper than s is and + + align:start position:0% +string that's one deeper than s is and + + + align:start position:0% +string that's one deeper than s is and +then you follow it by Tay and it's as + + align:start position:0% +then you follow it by Tay and it's as + + + align:start position:0% +then you follow it by Tay and it's as +deep as T is so the result is that the + + align:start position:0% +deep as T is so the result is that the + + + align:start position:0% +deep as T is so the result is that the +depth of the constructor is a string + + align:start position:0% +depth of the constructor is a string + + + align:start position:0% +depth of the constructor is a string +whose which is is a number which is + + align:start position:0% +whose which is is a number which is + + + align:start position:0% +whose which is is a number which is +equal to 1 plus the depth of s and the + + align:start position:0% +equal to 1 plus the depth of s and the + + + align:start position:0% +equal to 1 plus the depth of s and the +depth of T whichever is larger the max + + align:start position:0% +depth of T whichever is larger the max + + + align:start position:0% +depth of T whichever is larger the max +of 1 plus depth of s and depth of T and + + align:start position:0% +of 1 plus depth of s and depth of T and + + + align:start position:0% +of 1 plus depth of s and depth of T and +that's our recursive definition of depth + + align:start position:0% +that's our recursive definition of depth + + + align:start position:0% +that's our recursive definition of depth +let's look at maybe another even more + + align:start position:0% +let's look at maybe another even more + + + align:start position:0% +let's look at maybe another even more +familiar example of a recursive + + align:start position:0% +familiar example of a recursive + + + align:start position:0% +familiar example of a recursive +definition let's define the nth power of + + align:start position:0% +definition let's define the nth power of + + + align:start position:0% +definition let's define the nth power of +a an integer or real number + + align:start position:0% +a an integer or real number + + + align:start position:0% +a an integer or real number +kay the zeroth power of K is defined to + + align:start position:0% +kay the zeroth power of K is defined to + + + align:start position:0% +kay the zeroth power of K is defined to +be one and the n plus first power of K + + align:start position:0% +be one and the n plus first power of K + + + align:start position:0% +be one and the n plus first power of K +is defined to be K times the nth power + + align:start position:0% +is defined to be K times the nth power + + + align:start position:0% +is defined to be K times the nth power +of K and this would be an executable + + align:start position:0% +of K and this would be an executable + + + align:start position:0% +of K and this would be an executable +definition of the exponentiation + + align:start position:0% +definition of the exponentiation + + + align:start position:0% +definition of the exponentiation +function in a lot of programming + + align:start position:0% +function in a lot of programming + + + align:start position:0% +function in a lot of programming +languages and my point here is that this + + align:start position:0% +languages and my point here is that this + + + align:start position:0% +languages and my point here is that this +familiar definition a recursive + + align:start position:0% +familiar definition a recursive + + + align:start position:0% +familiar definition a recursive +definition on a non-negative integer n + + align:start position:0% +definition on a non-negative integer n + + + align:start position:0% +definition on a non-negative integer n +is in fact a structural induction using + + align:start position:0% +is in fact a structural induction using + + + align:start position:0% +is in fact a structural induction using +the fact that the natural numbers are + + align:start position:0% +the fact that the natural numbers are + + + align:start position:0% +the fact that the natural numbers are +sorry that the non-negative integers can + + align:start position:0% +sorry that the non-negative integers can + + + align:start position:0% +sorry that the non-negative integers can +be defined recursively as follows zero + + align:start position:0% +be defined recursively as follows zero + + + align:start position:0% +be defined recursively as follows zero +is a non-negative integer and if N is a + + align:start position:0% +is a non-negative integer and if N is a + + + align:start position:0% +is a non-negative integer and if N is a +non-negative integer then n plus 1 is a + + align:start position:0% +non-negative integer then n plus 1 is a + + + align:start position:0% +non-negative integer then n plus 1 is a +non-negative integer so to summarize the + + align:start position:0% +non-negative integer so to summarize the + + + align:start position:0% +non-negative integer so to summarize the +recipe for a recursive function + + align:start position:0% +recipe for a recursive function + + + align:start position:0% +recipe for a recursive function +definition is you define f going from + + align:start position:0% +definition is you define f going from + + + align:start position:0% +definition is you define f going from +the recursive data type to values + + align:start position:0% +the recursive data type to values + + + align:start position:0% +the recursive data type to values +whatever kind of values you want to + + align:start position:0% +whatever kind of values you want to + + + align:start position:0% +whatever kind of values you want to +assign to these recursive data F of B is + + align:start position:0% +assign to these recursive data F of B is + + + align:start position:0% +assign to these recursive data F of B is +defined directly for the base case B of + + align:start position:0% +defined directly for the base case B of + + + align:start position:0% +defined directly for the base case B of +base cases B and F of the constructor of + + align:start position:0% +base cases B and F of the constructor of + + + align:start position:0% +base cases B and F of the constructor of +X is defined using f of X and X now once + + align:start position:0% +X is defined using f of X and X now once + + + align:start position:0% +X is defined using f of X and X now once +you've gotten a function defined + + align:start position:0% +you've gotten a function defined + + + align:start position:0% +you've gotten a function defined +recursively you could start proving + + align:start position:0% +recursively you could start proving + + + align:start position:0% +recursively you could start proving +things about it by structural induction + + align:start position:0% +things about it by structural induction + + + align:start position:0% +things about it by structural induction +or by induction on its own definition or + + align:start position:0% +or by induction on its own definition or + + + align:start position:0% +or by induction on its own definition or +its own recursive definition so let's + + align:start position:0% +its own recursive definition so let's + + + align:start position:0% +its own recursive definition so let's +look at an example of that I want to + + align:start position:0% +look at an example of that I want to + + + align:start position:0% +look at an example of that I want to +prove the following property of the + + align:start position:0% +prove the following property of the + + + align:start position:0% +prove the following property of the +depth of strings in M namely that if I + + align:start position:0% +depth of strings in M namely that if I + + + align:start position:0% +depth of strings in M namely that if I +look at the length of a string R plus 2 + + align:start position:0% +look at the length of a string R plus 2 + + + align:start position:0% +look at the length of a string R plus 2 +so the brackets around R means the the + + align:start position:0% +so the brackets around R means the the + + + align:start position:0% +so the brackets around R means the the +number of of sorry the vertical bars + + align:start position:0% +number of of sorry the vertical bars + + + align:start position:0% +number of of sorry the vertical bars +around our mean the number of brackets + + align:start position:0% +around our mean the number of brackets + + + align:start position:0% +around our mean the number of brackets +in the string R plus 2 is less than or + + align:start position:0% +in the string R plus 2 is less than or + + + align:start position:0% +in the string R plus 2 is less than or +equal to 2 to the power a depth plus 1 + + align:start position:0% +equal to 2 to the power a depth plus 1 + + + align:start position:0% +equal to 2 to the power a depth plus 1 +twice the 2 to the depths of the string + + align:start position:0% +twice the 2 to the depths of the string + + + align:start position:0% +twice the 2 to the depths of the string +and I want to prove that this holds for + + align:start position:0% +and I want to prove that this holds for + + + align:start position:0% +and I want to prove that this holds for +all strings are of matched brackets and + + align:start position:0% +all strings are of matched brackets and + + + align:start position:0% +all strings are of matched brackets and +I'm going to prove it by structural + + align:start position:0% +I'm going to prove it by structural + + + align:start position:0% +I'm going to prove it by structural +induction and just as a walk through + + align:start position:0% +induction and just as a walk through + + + align:start position:0% +induction and just as a walk through +here's how the proof is going to go + + align:start position:0% +here's how the proof is going to go + + + align:start position:0% +here's how the proof is going to go +let's suppose that r is the base case + + align:start position:0% +let's suppose that r is the base case + + + align:start position:0% +let's suppose that r is the base case +is it the case that this inequality + + align:start position:0% +is it the case that this inequality + + + align:start position:0% +is it the case that this inequality +holds for the empty string well the + + align:start position:0% +holds for the empty string well the + + + align:start position:0% +holds for the empty string well the +length of our is zero so length of our + + align:start position:0% +length of our is zero so length of our + + + align:start position:0% +length of our is zero so length of our +plus two is 2 is 0 plus 2 or 2 which is + + align:start position:0% +plus two is 2 is 0 plus 2 or 2 which is + + + align:start position:0% +plus two is 2 is 0 plus 2 or 2 which is +the same as 2 to the 0 plus 1 which is + + align:start position:0% +the same as 2 to the 0 plus 1 which is + + + align:start position:0% +the same as 2 to the 0 plus 1 which is +in fact equal to 2 to the depth of the + + align:start position:0% +in fact equal to 2 to the depth of the + + + align:start position:0% +in fact equal to 2 to the depth of the +empty string plus 1 so this inequality + + align:start position:0% +empty string plus 1 so this inequality + + + align:start position:0% +empty string plus 1 so this inequality +actually holds as an equality in the + + align:start position:0% +actually holds as an equality in the + + + align:start position:0% +actually holds as an equality in the +base case and we're we're good there but + + align:start position:0% +base case and we're we're good there but + + + align:start position:0% +base case and we're we're good there but +we next leave this show is that this + + align:start position:0% +we next leave this show is that this + + + align:start position:0% +we next leave this show is that this +inequality holds in the constructor case + + align:start position:0% +inequality holds in the constructor case + + + align:start position:0% +inequality holds in the constructor case +so we're looking at a an arbitrary + + align:start position:0% +so we're looking at a an arbitrary + + + align:start position:0% +so we're looking at a an arbitrary +string R that's built out of s and T and + + align:start position:0% +string R that's built out of s and T and + + + align:start position:0% +string R that's built out of s and T and +R is left bracket S right bracket P and + + align:start position:0% +R is left bracket S right bracket P and + + + align:start position:0% +R is left bracket S right bracket P and +I want to show that our satisfies this + + align:start position:0% +I want to show that our satisfies this + + + align:start position:0% +I want to show that our satisfies this +inequality well by induction hypothesis + + align:start position:0% +inequality well by induction hypothesis + + + align:start position:0% +inequality well by induction hypothesis +I can assume the S&T satisfy the + + align:start position:0% +I can assume the S&T satisfy the + + + align:start position:0% +I can assume the S&T satisfy the +inequality so I have that the length of + + align:start position:0% +inequality so I have that the length of + + + align:start position:0% +inequality so I have that the length of +s plus 2 is at most 2 to the depth of s + + align:start position:0% +s plus 2 is at most 2 to the depth of s + + + align:start position:0% +s plus 2 is at most 2 to the depth of s +plus 1 and the length of T plus 2 is at + + align:start position:0% +plus 1 and the length of T plus 2 is at + + + align:start position:0% +plus 1 and the length of T plus 2 is at +most 2 to the depth of T plus 1 and + + align:start position:0% +most 2 to the depth of T plus 1 and + + + align:start position:0% +most 2 to the depth of T plus 1 and +let's just walk through the proof you + + align:start position:0% +let's just walk through the proof you + + + align:start position:0% +let's just walk through the proof you +can slow this down and replay it if need + + align:start position:0% +can slow this down and replay it if need + + + align:start position:0% +can slow this down and replay it if need +be some you're just going to go through + + align:start position:0% +be some you're just going to go through + + + align:start position:0% +be some you're just going to go through +it quickly the length of our plus 2r is + + align:start position:0% +it quickly the length of our plus 2r is + + + align:start position:0% +it quickly the length of our plus 2r is +after all brackets s T so it's simply + + align:start position:0% +after all brackets s T so it's simply + + + align:start position:0% +after all brackets s T so it's simply +the length of that string plus 2 by the + + align:start position:0% +the length of that string plus 2 by the + + + align:start position:0% +the length of that string plus 2 by the +definition of our the length of brackets + + align:start position:0% +definition of our the length of brackets + + + align:start position:0% +definition of our the length of brackets +s T is the length of T plus the length + + align:start position:0% +s T is the length of T plus the length + + + align:start position:0% +s T is the length of T plus the length +of s plus the 2 for the two brackets + + align:start position:0% +of s plus the 2 for the two brackets + + + align:start position:0% +of s plus the 2 for the two brackets +that we've added and so we're plugging + + align:start position:0% +that we've added and so we're plugging + + + align:start position:0% +that we've added and so we're plugging +that in to the previous term and getting + + align:start position:0% +that in to the previous term and getting + + + align:start position:0% +that in to the previous term and getting +that plus 2 then just rearrange the + + align:start position:0% +that plus 2 then just rearrange the + + + align:start position:0% +that plus 2 then just rearrange the +terms it's the same as the size of s + + align:start position:0% +terms it's the same as the size of s + + + align:start position:0% +terms it's the same as the size of s +plus 2 plus the size of T plus 2 and I + + align:start position:0% +plus 2 plus the size of T plus 2 and I + + + align:start position:0% +plus 2 plus the size of T plus 2 and I +arranged it that way because by + + align:start position:0% +arranged it that way because by + + + align:start position:0% +arranged it that way because by +induction hypothesis I know that the + + align:start position:0% +induction hypothesis I know that the + + + align:start position:0% +induction hypothesis I know that the +size of s plus 2 is less than or equal + + align:start position:0% +size of s plus 2 is less than or equal + + + align:start position:0% +size of s plus 2 is less than or equal +to 2 to the depth of s plus 1 and + + align:start position:0% +to 2 to the depth of s plus 1 and + + + align:start position:0% +to 2 to the depth of s plus 1 and +likewise for teh now I just play a nice + + align:start position:0% +likewise for teh now I just play a nice + + + align:start position:0% +likewise for teh now I just play a nice +trick to get these two exponents to look + + align:start position:0% +trick to get these two exponents to look + + + align:start position:0% +trick to get these two exponents to look +alike i I say that the depth of s is + + align:start position:0% +alike i I say that the depth of s is + + + align:start position:0% +alike i I say that the depth of s is +less than or equal to the max of the + + align:start position:0% +less than or equal to the max of the + + + align:start position:0% +less than or equal to the max of the +depth of s and the depth of T likewise + + align:start position:0% +depth of s and the depth of T likewise + + + align:start position:0% +depth of s and the depth of T likewise +for the depth of T so in both of those + + align:start position:0% +for the depth of T so in both of those + + + align:start position:0% +for the depth of T so in both of those +terms here I can replace the exponent or + + align:start position:0% +terms here I can replace the exponent or + + + align:start position:0% +terms here I can replace the exponent or +replace the depth of s by the max + + align:start position:0% +replace the depth of s by the max + + + align:start position:0% +replace the depth of s by the max +of depth SNT and likewise here now I've + + align:start position:0% +of depth SNT and likewise here now I've + + + align:start position:0% +of depth SNT and likewise here now I've +got the same term twice so I can say + + align:start position:0% +got the same term twice so I can say + + + align:start position:0% +got the same term twice so I can say +that it's simply twice the max depth and + + align:start position:0% +that it's simply twice the max depth and + + + align:start position:0% +that it's simply twice the max depth and +of course that is equal to by definition + + align:start position:0% +of course that is equal to by definition + + + align:start position:0% +of course that is equal to by definition +of the depth of our twice to to the + + align:start position:0% +of the depth of our twice to to the + + + align:start position:0% +of the depth of our twice to to the +depth of our which is of course two to + + align:start position:0% +depth of our which is of course two to + + + align:start position:0% +depth of our which is of course two to +the depth of our plus 1 and I have by + + align:start position:0% +the depth of our plus 1 and I have by + + + align:start position:0% +the depth of our plus 1 and I have by +more or less automatically plugging into + + align:start position:0% +more or less automatically plugging into + + + align:start position:0% +more or less automatically plugging into +the definitions and a structural + + align:start position:0% +the definitions and a structural + + + align:start position:0% +the definitions and a structural +induction I've proved that this + + align:start position:0% +induction I've proved that this + + + align:start position:0% +induction I've proved that this +inequality holds for the recursively + + align:start position:0% +inequality holds for the recursively + + + align:start position:0% +inequality holds for the recursively +defined depth function and we're done + + align:start position:0% +defined depth function and we're done + + + align:start position:0% +defined depth function and we're done +let's look at one more familiar example + + align:start position:0% +let's look at one more familiar example + + + align:start position:0% +let's look at one more familiar example +I want to give a recursive definition of + + align:start position:0% +I want to give a recursive definition of + + + align:start position:0% +I want to give a recursive definition of +the positive powers of two so the base + + align:start position:0% +the positive powers of two so the base + + + align:start position:0% +the positive powers of two so the base +case is that 2 is a positive power of 2 + + align:start position:0% +case is that 2 is a positive power of 2 + + + align:start position:0% +case is that 2 is a positive power of 2 +and the constructor is just one + + align:start position:0% +and the constructor is just one + + + align:start position:0% +and the constructor is just one +constructor I'm going to use that if x + + align:start position:0% +constructor I'm going to use that if x + + + align:start position:0% +constructor I'm going to use that if x +and y are positive powers of 2 then + + align:start position:0% +and y are positive powers of 2 then + + + align:start position:0% +and y are positive powers of 2 then +their product is a positive power of 2 + + align:start position:0% +their product is a positive power of 2 + + + align:start position:0% +their product is a positive power of 2 +so let's look at some examples I can + + align:start position:0% +so let's look at some examples I can + + + align:start position:0% +so let's look at some examples I can +start with 2 and then the only thing I + + align:start position:0% +start with 2 and then the only thing I + + + align:start position:0% +start with 2 and then the only thing I +can do as a constructor is multiply 2 by + + align:start position:0% +can do as a constructor is multiply 2 by + + + align:start position:0% +can do as a constructor is multiply 2 by +2 to get 4 once I got 4 I can do 4 times + + align:start position:0% +2 to get 4 once I got 4 I can do 4 times + + + align:start position:0% +2 to get 4 once I got 4 I can do 4 times +2 to get 8 and I can do 4 times 4 to get + + align:start position:0% +2 to get 8 and I can do 4 times 4 to get + + + align:start position:0% +2 to get 8 and I can do 4 times 4 to get +16 and I can do 4 times 8 to get 32 and + + align:start position:0% +16 and I can do 4 times 8 to get 32 and + + + align:start position:0% +16 and I can do 4 times 8 to get 32 and +all of these are positive powers of 2 + + align:start position:0% + + + + align:start position:0% + +now let's define the log to the base 2 + + align:start position:0% +now let's define the log to the base 2 + + + align:start position:0% +now let's define the log to the base 2 +of a positive power of tow recursively + + align:start position:0% +of a positive power of tow recursively + + + align:start position:0% +of a positive power of tow recursively +well the log to the base 2 of 2 is 1 I'd + + align:start position:0% +well the log to the base 2 of 2 is 1 I'd + + + align:start position:0% +well the log to the base 2 of 2 is 1 I'd +have to define log to the base 2 in the + + align:start position:0% +have to define log to the base 2 in the + + + align:start position:0% +have to define log to the base 2 in the +base case and that's easy to do what + + align:start position:0% +base case and that's easy to do what + + + align:start position:0% +base case and that's easy to do what +about in the constructor case well the + + align:start position:0% +about in the constructor case well the + + + align:start position:0% +about in the constructor case well the +log to the base 2 of X Y is equal to the + + align:start position:0% +log to the base 2 of X Y is equal to the + + + align:start position:0% +log to the base 2 of X Y is equal to the +log to the base 2 of X plus the log to + + align:start position:0% +log to the base 2 of X plus the log to + + + align:start position:0% +log to the base 2 of X plus the log to +the base 2 of Y for all the X why's that + + align:start position:0% +the base 2 of Y for all the X why's that + + + align:start position:0% +the base 2 of Y for all the X why's that +are positive powers of 2 and so I have + + align:start position:0% +are positive powers of 2 and so I have + + + align:start position:0% +are positive powers of 2 and so I have +defined log of the constructor X Y in + + align:start position:0% +defined log of the constructor X Y in + + + align:start position:0% +defined log of the constructor X Y in +terms of the function log of X and the + + align:start position:0% +terms of the function log of X and the + + + align:start position:0% +terms of the function log of X and the +function log applied to Y it conforms to + + align:start position:0% +function log applied to Y it conforms to + + + align:start position:0% +function log applied to Y it conforms to +the standard definition of + + align:start position:0% +the standard definition of + + + align:start position:0% +the standard definition of +a recursive function on a recursively + + align:start position:0% +a recursive function on a recursively + + + align:start position:0% +a recursive function on a recursively +defined data type the positive powers of + + align:start position:0% +defined data type the positive powers of + + + align:start position:0% +defined data type the positive powers of +two this looks okay let's just check it + + align:start position:0% +two this looks okay let's just check it + + + align:start position:0% +two this looks okay let's just check it +out so log of four is log of 2 times two + + align:start position:0% +out so log of four is log of 2 times two + + + align:start position:0% +out so log of four is log of 2 times two +which is by the by that definition of + + align:start position:0% +which is by the by that definition of + + + align:start position:0% +which is by the by that definition of +log the log of 2 plus the log of 2 which + + align:start position:0% +log the log of 2 plus the log of 2 which + + + align:start position:0% +log the log of 2 plus the log of 2 which +is 1 plus 1 which is equal to 2 and + + align:start position:0% +is 1 plus 1 which is equal to 2 and + + + align:start position:0% +is 1 plus 1 which is equal to 2 and +guess what that's correct the log of 8 + + align:start position:0% +guess what that's correct the log of 8 + + + align:start position:0% +guess what that's correct the log of 8 +well 8 is 2 times 4 so by the recursive + + align:start position:0% +well 8 is 2 times 4 so by the recursive + + + align:start position:0% +well 8 is 2 times 4 so by the recursive +definition that's the log of 2 plus the + + align:start position:0% +definition that's the log of 2 plus the + + + align:start position:0% +definition that's the log of 2 plus the +log of 4 which we previously figured out + + align:start position:0% +log of 4 which we previously figured out + + + align:start position:0% +log of 4 which we previously figured out +log of 4 was 2 so we get 3 and the + + align:start position:0% +log of 4 was 2 so we get 3 and the + + + align:start position:0% +log of 4 was 2 so we get 3 and the +answer comes out right now remember + + align:start position:0% +answer comes out right now remember + + + align:start position:0% +answer comes out right now remember +you're not supposed to end this + + align:start position:0% +you're not supposed to end this + + + align:start position:0% +you're not supposed to end this +reasoning use the properties that you + + align:start position:0% +reasoning use the properties that you + + + align:start position:0% +reasoning use the properties that you +know that log to the base 2 has because + + align:start position:0% +know that log to the base 2 has because + + + align:start position:0% +know that log to the base 2 has because +we're defining this function which were + + align:start position:0% +we're defining this function which were + + + align:start position:0% +we're defining this function which were +calling log to the base 2 and implicitly + + align:start position:0% +calling log to the base 2 and implicitly + + + align:start position:0% +calling log to the base 2 and implicitly +claiming that it's right but in order to + + align:start position:0% +claiming that it's right but in order to + + + align:start position:0% +claiming that it's right but in order to +prove that it's right we need to be + + align:start position:0% +prove that it's right we need to be + + + align:start position:0% +prove that it's right we need to be +using just the the structural definition + + align:start position:0% +using just the the structural definition + + + align:start position:0% +using just the the structural definition +of log to the base 2 to prove its + + align:start position:0% +of log to the base 2 to prove its + + + align:start position:0% +of log to the base 2 to prove its +properties so that was what I was + + align:start position:0% +properties so that was what I was + + + align:start position:0% +properties so that was what I was +illustrating with this reasoning that + + align:start position:0% +illustrating with this reasoning that + + + align:start position:0% +illustrating with this reasoning that +just plugging in the the constructor + + align:start position:0% +just plugging in the the constructor + + + align:start position:0% +just plugging in the the constructor +case of log of X Y as log of X plus log + + align:start position:0% +case of log of X Y as log of X plus log + + + align:start position:0% +case of log of X Y as log of X plus log +of Y I can get these numbers out so the + + align:start position:0% +of Y I can get these numbers out so the + + + align:start position:0% +of Y I can get these numbers out so the +point of this is just to make the + + align:start position:0% +point of this is just to make the + + + align:start position:0% +point of this is just to make the +following definition look reasonable I'm + + align:start position:0% +following definition look reasonable I'm + + + align:start position:0% +following definition look reasonable I'm +going to define a new function which I'm + + align:start position:0% +going to define a new function which I'm + + + align:start position:0% +going to define a new function which I'm +going to call the log e function + + align:start position:0% +going to call the log e function + + + align:start position:0% +going to call the log e function +it's another function on the positive + + align:start position:0% +it's another function on the positive + + + align:start position:0% +it's another function on the positive +powers of 2 and here's the definition of + + align:start position:0% +powers of 2 and here's the definition of + + + align:start position:0% +powers of 2 and here's the definition of +the log e function the log e of 2 is + + align:start position:0% +the log e function the log e of 2 is + + + align:start position:0% +the log e function the log e of 2 is +going to be one just as the log is but + + align:start position:0% +going to be one just as the log is but + + + align:start position:0% +going to be one just as the log is but +the log e of XY is gonna be X plus the + + align:start position:0% +the log e of XY is gonna be X plus the + + + align:start position:0% +the log e of XY is gonna be X plus the +log e of Y for all X Y in positive + + align:start position:0% +log e of Y for all X Y in positive + + + align:start position:0% +log e of Y for all X Y in positive +powers of 2 well let's try that + + align:start position:0% +powers of 2 well let's try that + + + align:start position:0% +powers of 2 well let's try that +definition log e of 4 is log you have 2 + + align:start position:0% +definition log e of 4 is log you have 2 + + + align:start position:0% +definition log e of 4 is log you have 2 +times 2 which according to the recursive + + align:start position:0% +times 2 which according to the recursive + + + align:start position:0% +times 2 which according to the recursive +definition is 2 plus the log e of 2 + + align:start position:0% +definition is 2 plus the log e of 2 + + + align:start position:0% +definition is 2 plus the log e of 2 +which is 1 namely it's 3 ok log e of 8 + + align:start position:0% +which is 1 namely it's 3 ok log e of 8 + + + align:start position:0% +which is 1 namely it's 3 ok log e of 8 +well 8 is 2 times 4 so the log e of 8 is + + align:start position:0% +well 8 is 2 times 4 so the log e of 8 is + + + align:start position:0% +well 8 is 2 times 4 so the log e of 8 is +2 plus the log e of 4 we just figured + + align:start position:0% +2 plus the log e of 4 we just figured + + + align:start position:0% +2 plus the log e of 4 we just figured +out that the loggia 4 was 3 so it's 2 + + align:start position:0% +out that the loggia 4 was 3 so it's 2 + + + align:start position:0% +out that the loggia 4 was 3 so it's 2 +plus 3 is 5 + + align:start position:0% +plus 3 is 5 + + + align:start position:0% +plus 3 is 5 +G of 8 is 5 and finally log e of 16 well + + align:start position:0% +G of 8 is 5 and finally log e of 16 well + + + align:start position:0% +G of 8 is 5 and finally log e of 16 well +16 is 8 times 2 so the log e of 8 times + + align:start position:0% +16 is 8 times 2 so the log e of 8 times + + + align:start position:0% +16 is 8 times 2 so the log e of 8 times +2 is 8 plus the log e of 2 which we know + + align:start position:0% +2 is 8 plus the log e of 2 which we know + + + align:start position:0% +2 is 8 plus the log e of 2 which we know +is 1 it's 9 so we've just figured out + + align:start position:0% +is 1 it's 9 so we've just figured out + + + align:start position:0% +is 1 it's 9 so we've just figured out +the log e of 16 is 9 but but now comes + + align:start position:0% +the log e of 16 is 9 but but now comes + + + align:start position:0% +the log e of 16 is 9 but but now comes +the problem 16 of course is not only 8 + + align:start position:0% +the problem 16 of course is not only 8 + + + align:start position:0% +the problem 16 of course is not only 8 +times 2 but it's 2 times 8 and so the + + align:start position:0% +times 2 but it's 2 times 8 and so the + + + align:start position:0% +times 2 but it's 2 times 8 and so the +log e of 2 times 8 is 2 plus the log e + + align:start position:0% +log e of 2 times 8 is 2 plus the log e + + + align:start position:0% +log e of 2 times 8 is 2 plus the log e +of 8 log e of 8 we previously figured + + align:start position:0% +of 8 log e of 8 we previously figured + + + align:start position:0% +of 8 log e of 8 we previously figured +out was 5 so the log e of 16 is 7 and + + align:start position:0% +out was 5 so the log e of 16 is 7 and + + + align:start position:0% +out was 5 so the log e of 16 is 7 and +now I have an inconsistency I have used + + align:start position:0% +now I have an inconsistency I have used + + + align:start position:0% +now I have an inconsistency I have used +this recursive definition of log E to + + align:start position:0% +this recursive definition of log E to + + + align:start position:0% +this recursive definition of log E to +conclude that the log e of 16 is both 9 + + align:start position:0% +conclude that the log e of 16 is both 9 + + + align:start position:0% +conclude that the log e of 16 is both 9 +and 7 and we got a problem it's not a + + align:start position:0% +and 7 and we got a problem it's not a + + + align:start position:0% +and 7 and we got a problem it's not a +good definition of a function the + + align:start position:0% +good definition of a function the + + + align:start position:0% +good definition of a function the +problem is a simple one called ambiguity + + align:start position:0% +problem is a simple one called ambiguity + + + align:start position:0% +problem is a simple one called ambiguity +there's more than one way to construct + + align:start position:0% +there's more than one way to construct + + + align:start position:0% +there's more than one way to construct +the elements of pp2 of positive powers + + align:start position:0% +the elements of pp2 of positive powers + + + align:start position:0% +the elements of pp2 of positive powers +of 2 from the constructor x times y 16 + + align:start position:0% +of 2 from the constructor x times y 16 + + + align:start position:0% +of 2 from the constructor x times y 16 +was 8 times 2 but it's also 2 times 8 + + align:start position:0% +was 8 times 2 but it's also 2 times 8 + + + align:start position:0% +was 8 times 2 but it's also 2 times 8 +and of course it's also 4 times 4 and + + align:start position:0% + + + + align:start position:0% + +depending on which constructor you use + + align:start position:0% +depending on which constructor you use + + + align:start position:0% +depending on which constructor you use +to construct 16 you're going to get out + + align:start position:0% +to construct 16 you're going to get out + + + align:start position:0% +to construct 16 you're going to get out +different values assigned to the log e + + align:start position:0% +different values assigned to the log e + + + align:start position:0% +different values assigned to the log e +function so when you have an ambiguously + + align:start position:0% +function so when you have an ambiguously + + + align:start position:0% +function so when you have an ambiguously +defined recursive data structure for + + align:start position:0% +defined recursive data structure for + + + align:start position:0% +defined recursive data structure for +example F 18 is very ambiguous then + + align:start position:0% +example F 18 is very ambiguous then + + + align:start position:0% +example F 18 is very ambiguous then +defining a function defining recursive + + align:start position:0% +defining a function defining recursive + + + align:start position:0% +defining a function defining recursive +functions on that definition is not + + align:start position:0% +functions on that definition is not + + + align:start position:0% +functions on that definition is not +going to work well and you have to very + + align:start position:0% +going to work well and you have to very + + + align:start position:0% +going to work well and you have to very +carefully prove that if a recursive + + align:start position:0% +carefully prove that if a recursive + + + align:start position:0% +carefully prove that if a recursive +definition actually works in his + + align:start position:0% +definition actually works in his + + + align:start position:0% +definition actually works in his +single-valued so for example log to the + + align:start position:0% +single-valued so for example log to the + + + align:start position:0% +single-valued so for example log to the +base 2 does work but that would require + + align:start position:0% +base 2 does work but that would require + + + align:start position:0% +base 2 does work but that would require +proof it doesn't follow on general + + align:start position:0% +proof it doesn't follow on general + + + align:start position:0% +proof it doesn't follow on general +principles when you define a recursive + + align:start position:0% +principles when you define a recursive + + + align:start position:0% +principles when you define a recursive +function on a an ambiguous data type + + align:start position:0% +function on a an ambiguous data type + + + align:start position:0% +function on a an ambiguous data type +I mean only hand the reason why we chose + + align:start position:0% +I mean only hand the reason why we chose + + + align:start position:0% +I mean only hand the reason why we chose +that somewhat unexpected single + + align:start position:0% +that somewhat unexpected single + + + align:start position:0% +that somewhat unexpected single +constructor for the balanced strings am + + align:start position:0% +constructor for the balanced strings am + + + align:start position:0% +constructor for the balanced strings am +ballast the balanced bracket strings was + + align:start position:0% +ballast the balanced bracket strings was + + + align:start position:0% +ballast the balanced bracket strings was +that it turns out + + align:start position:0% +that it turns out + + + align:start position:0% +that it turns out +be unambiguous and so that definition of + + align:start position:0% +be unambiguous and so that definition of + + + align:start position:0% +be unambiguous and so that definition of +depth is a good definition as is any + + align:start position:0% +depth is a good definition as is any + + + align:start position:0% +depth is a good definition as is any +definition based on the recursive + + align:start position:0% +definition based on the recursive + + + align:start position:0% +definition based on the recursive +definition of the set M so the general + + align:start position:0% +definition of the set M so the general + + + align:start position:0% +definition of the set M so the general +problem we have to watch out for + + align:start position:0% + + + + align:start position:0% + +instructor created the datum II if + + align:start position:0% +instructor created the datum II if + + + align:start position:0% +instructor created the datum II if +there's more than one way to construct e + + align:start position:0% +there's more than one way to construct e + + + align:start position:0% +there's more than one way to construct e +then you're gonna you're not quite sure + + align:start position:0% +then you're gonna you're not quite sure + + + align:start position:0% +then you're gonna you're not quite sure +which case to use to define the function + + align:start position:0% +which case to use to define the function + + + align:start position:0% +which case to use to define the function +f and that's why this issue of whether + + align:start position:0% +f and that's why this issue of whether + + + align:start position:0% +f and that's why this issue of whether +or not the data structures ambiguous is + + align:start position:0% +or not the data structures ambiguous is + + + align:start position:0% +or not the data structures ambiguous is +critical to getting good definitions of + + align:start position:0% +critical to getting good definitions of + + + align:start position:0% +critical to getting good definitions of +recursive functions \ No newline at end of file diff --git a/tYkr4jMSOFg.txt b/tYkr4jMSOFg.txt new file mode 100644 index 0000000000000000000000000000000000000000..1be95bb787baeab6ee39253ee48822dfe74bea61 --- /dev/null +++ b/tYkr4jMSOFg.txt @@ -0,0 +1,206 @@ +PHIL: I mean everyone will +probably eat lunch. + +It's just a matter of where they +eat it and who they eat + +it with and if they +pay for it. + +I mean, I'm sure everyone's +going to eat lunch on a day, + +but some are going to have +to buy their own. + +Some are going to be +dining with me. + +[MUSIC PLAYING] + +NARRATOR: Yesterday in 5.301, +the students set up their + +crystal growing experiments, +and some are growing fast. + +JULIE: My crystal was +the first to form. + +I think this is the largest +one I've seen so far. + +So I thought I had won. + +JOHN DOLHUN: Well, Julie +did get her crystal. + +So I saw it with my own eyes. + +NARRATOR: Other crystals are +growing too, but their owner + +isn't looking. + +When Jason finally checks up +on his crystals, they're + +looking good. + +TENGFEI: In this well, we have +several a single crystals, and + +they are all big. + +JASON: She had a crystal first, +but I haven't been + +checking mine daily. + +So I might have a +crystal first. + +I don't know. + +TENGFEI: Congratulations. + +JASON: Thank you. + +JULIE: I had a single crystal. + +JASON: But I had multiple +single crystals. + +JULIE: What? + +JASON: I had multiple +single crystals. + +JULIE: But my crystal +came first. + +JASON: + +JULIE: I'm not going +to bring it up. + +I'm still the winner +as of right now. + +JASON: I'm gonna bring it up. + +I won. + +I had the largest crystal. + +I just didn't check it because +I didn't want to disturb it. + +Mine is definitely +bigger, clearly. + +JULIE: OK, but mine crystallized +like made a + +single crystal first. + +JASON: And like Julie was like, +I won, I won, I won. + +I've got this tiny +little crystal. + +I just got it first. + +No. + +The competition was the largest + +crystal in one week period. + +So I checked after one week. + +JULIE: His fault for not talking +to Dr. Dolhun earlier. + +So-- + +JASON: If I would have just like +looked at it earlier and + +told Dr. Dolhun earlier, I have +a crystal growing, then I + +would have won. + +JOHN DOLHUN: But you see +yeah, Jason, if you + +would have came forward-- + +JASON: I checked mine later. + +And then I told Dr. Dolhun. + +He was like, yeah, +but Julie won. + +JOHN DOLHUN: We've already +declared a winner here. + +JULIE: Mine. + +Fantastic. + +JASON: Julie rubs it in +my face all the time. + +JULIE: I mean, I was already +declared the winner, so he + +can't, yeah. + +He's honorable mention. + +NARRATOR: So Julie wins the +prize, lunch for her and a + +friend or so she thinks. + +PHIL: They both grew really +beautiful single crystals. + +So the whole class got to enjoy +a lunch with the TAs and + +the instructor. + +PHIL: We ended up going to +Chinatown for dim sum. + +And I have actually never +tried dim sum before. + +So I got to try a lot +of new foods, + +chicken feet, and tripe. + +JASON: It's basically +the lining of a + +cow's stomach, I think. + +PHIL: It was good. + +It was good. + +I always enjoy trying new +food, so everyone had + +a really good time. + +I've never felt so close to +dying in my entire life. + +[MUSIC PLAYING] \ No newline at end of file diff --git a/ttuvXdZNcDM.txt b/ttuvXdZNcDM.txt new file mode 100644 index 0000000000000000000000000000000000000000..a3652ba3fb41c5c1fa0d55f927684d758d95ff65 --- /dev/null +++ b/ttuvXdZNcDM.txt @@ -0,0 +1,291 @@ +align:start position:0% + +basically just a programmable visualizer + + align:start position:0% +basically just a programmable visualizer + + + align:start position:0% +basically just a programmable visualizer +that uses an LED array and ugly no so + + align:start position:0% +that uses an LED array and ugly no so + + + align:start position:0% +that uses an LED array and ugly no so +basically we wanted to be able to have + + align:start position:0% +basically we wanted to be able to have + + + align:start position:0% +basically we wanted to be able to have +cool modern art that's moving with our + + align:start position:0% +cool modern art that's moving with our + + + align:start position:0% +cool modern art that's moving with our +loss and it can display what sorts of + + align:start position:0% +loss and it can display what sorts of + + + align:start position:0% +loss and it can display what sorts of +things basically anything we wanted to + + align:start position:0% +things basically anything we wanted to + + + align:start position:0% +things basically anything we wanted to +but for now we'll just do a little demo + + align:start position:0% +but for now we'll just do a little demo + + + align:start position:0% +but for now we'll just do a little demo +the Lord it looks like we kind of a + + align:start position:0% +the Lord it looks like we kind of a + + + align:start position:0% +the Lord it looks like we kind of a +really colorful pattern and these are of + + align:start position:0% +really colorful pattern and these are of + + + align:start position:0% +really colorful pattern and these are of +course separate ones so they're not + + align:start position:0% +course separate ones so they're not + + + align:start position:0% +course separate ones so they're not +connected to just one are do you know + + align:start position:0% +connected to just one are do you know + + + align:start position:0% +connected to just one are do you know +because we all wanted to take one home + + align:start position:0% +because we all wanted to take one home + + + align:start position:0% +because we all wanted to take one home +they're also four of us in the group + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +so I mean kind of variations I wanted + + align:start position:0% +so I mean kind of variations I wanted + + + align:start position:0% +so I mean kind of variations I wanted +this is like a standalone this is like + + align:start position:0% +this is like a standalone this is like + + + align:start position:0% +this is like a standalone this is like +one of the bigger versions and then + + align:start position:0% +one of the bigger versions and then + + + align:start position:0% +one of the bigger versions and then +these are my kind of smaller versions + + align:start position:0% +these are my kind of smaller versions + + + align:start position:0% +these are my kind of smaller versions +that can be I guess these three can face + + align:start position:0% +that can be I guess these three can face + + + align:start position:0% +that can be I guess these three can face +up photo frames and you can program on + + align:start position:0% +up photo frames and you can program on + + + align:start position:0% +up photo frames and you can program on +it + + align:start position:0% +it + + + align:start position:0% +it +so we're exploring some + + align:start position:0% + + + + align:start position:0% + +so I think I'll just put Pryor + + align:start position:0% +so I think I'll just put Pryor + + + align:start position:0% +so I think I'll just put Pryor +you like + + align:start position:0% + + + + align:start position:0% + +it's not great like resolution just + + align:start position:0% +it's not great like resolution just + + + align:start position:0% +it's not great like resolution just +like one led per square inch + + align:start position:0% + + + + align:start position:0% + +let's cool under fire + + align:start position:0% + + + + align:start position:0% + +oh yeah the original time is activated + + align:start position:0% +oh yeah the original time is activated + + + align:start position:0% +oh yeah the original time is activated +in the frame were thrust of blacks but + + align:start position:0% +in the frame were thrust of blacks but + + + align:start position:0% +in the frame were thrust of blacks but +they were ordered I don't think they can + + align:start position:0% +they were ordered I don't think they can + + + align:start position:0% +they were ordered I don't think they can +even though unfortunately but this will + + align:start position:0% +even though unfortunately but this will + + + align:start position:0% +even though unfortunately but this will +do but it's cool because we'll be able + + align:start position:0% +do but it's cool because we'll be able + + + align:start position:0% +do but it's cool because we'll be able +to use these for you know anything from + + align:start position:0% +to use these for you know anything from + + + align:start position:0% +to use these for you know anything from +danger visualization next arts or + + align:start position:0% +danger visualization next arts or + + + align:start position:0% +danger visualization next arts or +something for just like nice artwork if + + align:start position:0% +something for just like nice artwork if + + + align:start position:0% +something for just like nice artwork if +you draw on the paper as well + + align:start position:0% +you draw on the paper as well + + + align:start position:0% +you draw on the paper as well +and fill it in with \ No newline at end of file diff --git a/v90JNWCTupk.txt b/v90JNWCTupk.txt new file mode 100644 index 0000000000000000000000000000000000000000..c65b6bbf7c841612b6fabeb1b74cc8fedfd9bb89 --- /dev/null +++ b/v90JNWCTupk.txt @@ -0,0 +1,1563 @@ +align:start position:0% + +Hi, welcome back to recitation. We've + + align:start position:0% +Hi, welcome back to recitation. We've + + + align:start position:0% +Hi, welcome back to recitation. We've +been talking in lecture about + + align:start position:0% +been talking in lecture about + + + align:start position:0% +been talking in lecture about +anti-derivatives. So I have here a + + align:start position:0% +anti-derivatives. So I have here a + + + align:start position:0% +anti-derivatives. So I have here a +problem for you, just an exercise about + + align:start position:0% +problem for you, just an exercise about + + + align:start position:0% +problem for you, just an exercise about +computing an anti-derivative. So the + + align:start position:0% +computing an anti-derivative. So the + + + align:start position:0% +computing an anti-derivative. So the +question is to compute an + + align:start position:0% +question is to compute an + + + align:start position:0% +question is to compute an +anti-derivative of this big fraction. So + + align:start position:0% +anti-derivative of this big fraction. So + + + align:start position:0% +anti-derivative of this big fraction. So +it on top it's got x 8 + 2x cubed - x + + align:start position:0% +it on top it's got x 8 + 2x cubed - x + + + align:start position:0% +it on top it's got x 8 + 2x cubed - x +2/3 - 3 that whole thing over x^2. + + align:start position:0% +2/3 - 3 that whole thing over x^2. + + + align:start position:0% +2/3 - 3 that whole thing over x^2. +So just a a quick linguistic note about + + align:start position:0% +So just a a quick linguistic note about + + + align:start position:0% +So just a a quick linguistic note about +about why I said an anti-derivatives + + align:start position:0% +about why I said an anti-derivatives + + + align:start position:0% +about why I said an anti-derivatives +instead of the anti-derivative and then + + align:start position:0% +instead of the anti-derivative and then + + + align:start position:0% +instead of the anti-derivative and then +I'll I'll let you work on it a little. + + align:start position:0% +I'll I'll let you work on it a little. + + + align:start position:0% +I'll I'll let you work on it a little. +So an anti-derivative there are many + + align:start position:0% +So an anti-derivative there are many + + + align:start position:0% +So an anti-derivative there are many +functions whose whose derivative is is + + align:start position:0% +functions whose whose derivative is is + + + align:start position:0% +functions whose whose derivative is is +this function right? So, so they all + + align:start position:0% +this function right? So, so they all + + + align:start position:0% +this function right? So, so they all +differ from each other by by constants, + + align:start position:0% +differ from each other by by constants, + + + align:start position:0% +differ from each other by by constants, +but but um so you know I would be happy + + align:start position:0% +but but um so you know I would be happy + + + align:start position:0% +but but um so you know I would be happy +with any one as an answer to this + + align:start position:0% +with any one as an answer to this + + + align:start position:0% +with any one as an answer to this +question. That's why I chose the the + + align:start position:0% +question. That's why I chose the the + + + align:start position:0% +question. That's why I chose the the +word an anti-derivant and + + align:start position:0% +word an anti-derivant and + + + align:start position:0% +word an anti-derivant and +anti-derivative. So I'm looking for a + + align:start position:0% +anti-derivative. So I'm looking for a + + + align:start position:0% +anti-derivative. So I'm looking for a +function whose derivative is equal to + + align:start position:0% +function whose derivative is equal to + + + align:start position:0% +function whose derivative is equal to +this function. So why don't you take a + + align:start position:0% +this function. So why don't you take a + + + align:start position:0% +this function. So why don't you take a +couple minutes work this out come back + + align:start position:0% +couple minutes work this out come back + + + align:start position:0% +couple minutes work this out come back +and you can check your answer against my + + align:start position:0% +and you can check your answer against my + + + align:start position:0% +and you can check your answer against my +work. + + align:start position:0% + + + + align:start position:0% + +Okay, welcome back. So, we were just + + align:start position:0% +Okay, welcome back. So, we were just + + + align:start position:0% +Okay, welcome back. So, we were just +talking about uh this anti-derivative + + align:start position:0% +talking about uh this anti-derivative + + + align:start position:0% +talking about uh this anti-derivative +here. So, one thing you'll you'll notice + + align:start position:0% +here. So, one thing you'll you'll notice + + + align:start position:0% +here. So, one thing you'll you'll notice +about this function is that I've written + + align:start position:0% +about this function is that I've written + + + align:start position:0% +about this function is that I've written +this in a sort of silly form. And it + + align:start position:0% +this in a sort of silly form. And it + + + align:start position:0% +this in a sort of silly form. And it +it's probably a lot easier to get a get + + align:start position:0% +it's probably a lot easier to get a get + + + align:start position:0% +it's probably a lot easier to get a get +a feel for what this function is if you + + align:start position:0% +a feel for what this function is if you + + + align:start position:0% +a feel for what this function is if you +if you break this fraction apart into + + align:start position:0% +if you break this fraction apart into + + + align:start position:0% +if you break this fraction apart into +its several pieces. So, for example, x + + align:start position:0% +its several pieces. So, for example, x + + + align:start position:0% +its several pieces. So, for example, x +to the eth over x^2 is just x. So, well, + + align:start position:0% +to the eth over x^2 is just x. So, well, + + + align:start position:0% +to the eth over x^2 is just x. So, well, +okay. Okay. So let me So this this + + align:start position:0% +okay. Okay. So let me So this this + + + align:start position:0% +okay. Okay. So let me So this this +anti-derivative that I'm interested in + + align:start position:0% +anti-derivative that I'm interested in + + + align:start position:0% +anti-derivative that I'm interested in +anti-derivative of x 8 + 2x cub - x^ 2/3 + + align:start position:0% +anti-derivative of x 8 + 2x cub - x^ 2/3 + + + align:start position:0% +anti-derivative of x 8 + 2x cub - x^ 2/3 +- 3 + + align:start position:0% +- 3 + + + align:start position:0% +- 3 +over x^2 + + align:start position:0% +over x^2 + + + align:start position:0% +over x^2 +dx. So I've written this in the silly + + align:start position:0% +dx. So I've written this in the silly + + + align:start position:0% +dx. So I've written this in the silly +form and you can get it in a nicer form + + align:start position:0% +form and you can get it in a nicer form + + + align:start position:0% +form and you can get it in a nicer form +if you if you just realize that you know + + align:start position:0% +if you if you just realize that you know + + + align:start position:0% +if you if you just realize that you know +this is just a sum of powers of x that + + align:start position:0% +this is just a sum of powers of x that + + + align:start position:0% +this is just a sum of powers of x that +I've I've sort of put over this silly + + align:start position:0% +I've I've sort of put over this silly + + + align:start position:0% +I've I've sort of put over this silly +common denominator here. So okay so so + + align:start position:0% +common denominator here. So okay so so + + + align:start position:0% +common denominator here. So okay so so +our life will be a little simpler if we + + align:start position:0% +our life will be a little simpler if we + + + align:start position:0% +our life will be a little simpler if we +write this out by splitting it up uh + + align:start position:0% +write this out by splitting it up uh + + + align:start position:0% +write this out by splitting it up uh +into the the separate fractions. So if I + + align:start position:0% +into the the separate fractions. So if I + + + align:start position:0% +into the the separate fractions. So if I +do that, this is just equal to the + + align:start position:0% +do that, this is just equal to the + + + align:start position:0% +do that, this is just equal to the +anti-derivative of well x to the eth + + align:start position:0% +anti-derivative of well x to the eth + + + align:start position:0% +anti-derivative of well x to the eth +overx^2 that's x 6 and 2x cubed over x^2 + + align:start position:0% +overx^2 that's x 6 and 2x cubed over x^2 + + + align:start position:0% +overx^2 that's x 6 and 2x cubed over x^2 +is just x. So I have x sorry it's 2x + + align:start position:0% +is just x. So I have x sorry it's 2x + + + align:start position:0% +is just x. So I have x sorry it's 2x ++ 2x + + align:start position:0% ++ 2x + + + align:start position:0% ++ 2x +now okay so x to the 2/3 over x^2. So + + align:start position:0% +now okay so x to the 2/3 over x^2. So + + + align:start position:0% +now okay so x to the 2/3 over x^2. So +that's x to the 2/3 minus 2 which is x + + align:start position:0% +that's x to the 2/3 minus 2 which is x + + + align:start position:0% +that's x to the 2/3 minus 2 which is x +to the - 4/3 + + align:start position:0% +to the - 4/3 + + + align:start position:0% +to the - 4/3 +and - 3x^2. So okay so we could write + + align:start position:0% +and - 3x^2. So okay so we could write + + + align:start position:0% +and - 3x^2. So okay so we could write +that as - 3x^2 or maybe it's a little + + align:start position:0% +that as - 3x^2 or maybe it's a little + + + align:start position:0% +that as - 3x^2 or maybe it's a little +more convenient to write it as -3 x -2 + + align:start position:0% +more convenient to write it as -3 x -2 + + + align:start position:0% +more convenient to write it as -3 x -2 +dx. So, so far I haven't really done + + align:start position:0% +dx. So, so far I haven't really done + + + align:start position:0% +dx. So, so far I haven't really done +anything, you know, a little bit of a + + align:start position:0% +anything, you know, a little bit of a + + + align:start position:0% +anything, you know, a little bit of a +little bit of algebra here. Okay. But + + align:start position:0% +little bit of algebra here. Okay. But + + + align:start position:0% +little bit of algebra here. Okay. But +now we know that we we've we've seen a + + align:start position:0% +now we know that we we've we've seen a + + + align:start position:0% +now we know that we we've we've seen a +formula for anti anti-ifferiating a + + align:start position:0% +formula for anti anti-ifferiating a + + + align:start position:0% +formula for anti anti-ifferiating a +single power of x. I mean, we know how + + align:start position:0% +single power of x. I mean, we know how + + + align:start position:0% +single power of x. I mean, we know how +to differentiate a single power of x. + + align:start position:0% +to differentiate a single power of x. + + + align:start position:0% +to differentiate a single power of x. +And so to do an anti-derivative is just + + align:start position:0% +And so to do an anti-derivative is just + + + align:start position:0% +And so to do an anti-derivative is just +the the inverse process. Um, and + + align:start position:0% +the the inverse process. Um, and + + + align:start position:0% +the the inverse process. Um, and +we also know that when you have the + + align:start position:0% +we also know that when you have the + + + align:start position:0% +we also know that when you have the +derivative of a sum, it's the sum of + + align:start position:0% +derivative of a sum, it's the sum of + + + align:start position:0% +derivative of a sum, it's the sum of +derivatives. And so consequently, if you + + align:start position:0% +derivatives. And so consequently, if you + + + align:start position:0% +derivatives. And so consequently, if you +have the anti-derivative of a sum, it's + + align:start position:0% +have the anti-derivative of a sum, it's + + + align:start position:0% +have the anti-derivative of a sum, it's +just the sum of the anti-derivatives. So + + align:start position:0% +just the sum of the anti-derivatives. So + + + align:start position:0% +just the sum of the anti-derivatives. So +we can write this out into its into its + + align:start position:0% +we can write this out into its into its + + + align:start position:0% +we can write this out into its into its +constituent parts. So it's the + + align:start position:0% +constituent parts. So it's the + + + align:start position:0% +constituent parts. So it's the +anti-derivative of x to the 6 dx + + align:start position:0% +anti-derivative of x to the 6 dx + + + align:start position:0% +anti-derivative of x to the 6 dx +plus the anti. Now, of course, you don't + + align:start position:0% +plus the anti. Now, of course, you don't + + + align:start position:0% +plus the anti. Now, of course, you don't +have to do this. You could probably + + align:start position:0% +have to do this. You could probably + + + align:start position:0% +have to do this. You could probably +proceed just from this step onwards or + + align:start position:0% +proceed just from this step onwards or + + + align:start position:0% +proceed just from this step onwards or +uh but but I don't see any harm in in + + align:start position:0% +uh but but I don't see any harm in in + + + align:start position:0% +uh but but I don't see any harm in in +actually splitting it up myself. So + + align:start position:0% +actually splitting it up myself. So + + + align:start position:0% +actually splitting it up myself. So +anti-derivative of 2x dxus + + align:start position:0% +anti-derivative of 2x dxus + + + align:start position:0% +anti-derivative of 2x dxus +okay x to the - 4/3 dx + + align:start position:0% +okay x to the - 4/3 dx + + + align:start position:0% +okay x to the - 4/3 dx +plus + + align:start position:0% +plus + + + align:start position:0% +plus +- 3x to the - 2 dx. Okay, so I just + + align:start position:0% +- 3x to the - 2 dx. Okay, so I just + + + align:start position:0% +- 3x to the - 2 dx. Okay, so I just +split it up into a bunch of pieces. Oh, + + align:start position:0% +split it up into a bunch of pieces. Oh, + + + align:start position:0% +split it up into a bunch of pieces. Oh, +I guess this one I sort of pulled the + + align:start position:0% +I guess this one I sort of pulled the + + + align:start position:0% +I guess this one I sort of pulled the +minus sign out and this one I didn't. + + align:start position:0% +minus sign out and this one I didn't. + + + align:start position:0% +minus sign out and this one I didn't. +But you know, whatever e either either + + align:start position:0% +But you know, whatever e either either + + + align:start position:0% +But you know, whatever e either either +way. Um, okay. So now, now we just need + + align:start position:0% +way. Um, okay. So now, now we just need + + + align:start position:0% +way. Um, okay. So now, now we just need +to remember our our formulas for for + + align:start position:0% +to remember our our formulas for for + + + align:start position:0% +to remember our our formulas for for +taking the anti-derivative of a power of + + align:start position:0% +taking the anti-derivative of a power of + + + align:start position:0% +taking the anti-derivative of a power of +x. So in order to do that, so when you + + align:start position:0% +x. So in order to do that, so when you + + + align:start position:0% +x. So in order to do that, so when you +take a derivative, + + align:start position:0% +take a derivative, + + + align:start position:0% +take a derivative, +the the power goes down by one. So if + + align:start position:0% +the the power goes down by one. So if + + + align:start position:0% +the the power goes down by one. So if +you take an anti-derivative, the power + + align:start position:0% +you take an anti-derivative, the power + + + align:start position:0% +you take an anti-derivative, the power +will always go up by one. So + + align:start position:0% +will always go up by one. So + + + align:start position:0% +will always go up by one. So +in this case, you get so you're going to + + align:start position:0% +in this case, you get so you're going to + + + align:start position:0% +in this case, you get so you're going to +get x to the 7th. And now when you + + align:start position:0% +get x to the 7th. And now when you + + + align:start position:0% +get x to the 7th. And now when you +differentiate x to the 7th a seven comes + + align:start position:0% +differentiate x to the 7th a seven comes + + + align:start position:0% +differentiate x to the 7th a seven comes +down in front right you get 7 x to the + + align:start position:0% +down in front right you get 7 x to the + + + align:start position:0% +down in front right you get 7 x to the +6th. So in order to get just x to the + + align:start position:0% +6th. So in order to get just x to the + + + align:start position:0% +6th. So in order to get just x to the +6th we have to also divide by that seven + + align:start position:0% +6th we have to also divide by that seven + + + align:start position:0% +6th we have to also divide by that seven +there. So x to the 6 the anti-derivative + + align:start position:0% +there. So x to the 6 the anti-derivative + + + align:start position:0% +there. So x to the 6 the anti-derivative +is x 7th over 7 2x. So that's going to + + align:start position:0% +is x 7th over 7 2x. So that's going to + + + align:start position:0% +is x 7th over 7 2x. So that's going to +give us plus + + align:start position:0% +give us plus + + + align:start position:0% +give us plus +2x^2 + + align:start position:0% +2x^2 + + + align:start position:0% +2x^2 +over 2. Or if you like you could just + + align:start position:0% +over 2. Or if you like you could just + + + align:start position:0% +over 2. Or if you like you could just +recognize right away that 2x is the + + align:start position:0% +recognize right away that 2x is the + + + align:start position:0% +recognize right away that 2x is the +derivative of x^2. + + align:start position:0% +derivative of x^2. + + + align:start position:0% +derivative of x^2. +um + + align:start position:0% +um + + + align:start position:0% +um +minus okay now we've got minus powers + + align:start position:0% +minus okay now we've got minus powers + + + align:start position:0% +minus okay now we've got minus powers +rather negative powers so so that always + + align:start position:0% +rather negative powers so so that always + + + align:start position:0% +rather negative powers so so that always +is a little trickier to to keep track of + + align:start position:0% +is a little trickier to to keep track of + + + align:start position:0% +is a little trickier to to keep track of +so again the same thing is true though + + align:start position:0% +so again the same thing is true though + + + align:start position:0% +so again the same thing is true though +you have to you add one to the to the + + align:start position:0% +you have to you add one to the to the + + + align:start position:0% +you have to you add one to the to the +exponent the exponent goes up by one + + align:start position:0% +exponent the exponent goes up by one + + + align:start position:0% +exponent the exponent goes up by one +when you take an anti-derivative goes + + align:start position:0% +when you take an anti-derivative goes + + + align:start position:0% +when you take an anti-derivative goes +down by one when you take a derivative + + align:start position:0% +down by one when you take a derivative + + + align:start position:0% +down by one when you take a derivative +so okay so when you add one to minus 4/3 + + align:start position:0% +so okay so when you add one to minus 4/3 + + + align:start position:0% +so okay so when you add one to minus 4/3 +you get -3 so we have x to the minus + + align:start position:0% +you get -3 so we have x to the minus + + + align:start position:0% +you get -3 so we have x to the minus +1/3 and then I have to divide divide by + + align:start position:0% +1/3 and then I have to divide divide by + + + align:start position:0% +1/3 and then I have to divide divide by +minus + + align:start position:0% +minus + + + align:start position:0% +minus +1/3 when I take a derivative here we get + + align:start position:0% +1/3 when I take a derivative here we get + + + align:start position:0% +1/3 when I take a derivative here we get +of of x^us 1/3 I get - 1/3 x to the - + + align:start position:0% +of of x^us 1/3 I get - 1/3 x to the - + + + align:start position:0% +of of x^us 1/3 I get - 1/3 x to the - +4/3 so I need to divide by that - 1/3 + + align:start position:0% +4/3 so I need to divide by that - 1/3 + + + align:start position:0% +4/3 so I need to divide by that - 1/3 +okay and finally here so - 3x^us2 + + align:start position:0% +okay and finally here so - 3x^us2 + + + align:start position:0% +okay and finally here so - 3x^us2 +so okay so so just like this first one + + align:start position:0% +so okay so so just like this first one + + + align:start position:0% +so okay so so just like this first one +you you you might recognize that right + + align:start position:0% +you you you might recognize that right + + + align:start position:0% +you you you might recognize that right +off as the derivative of x to the minus + + align:start position:0% +off as the derivative of x to the minus + + + align:start position:0% +off as the derivative of x to the minus +3 so this is plus + + align:start position:0% +3 so this is plus + + + align:start position:0% +3 so this is plus +Oh. Oh. Uh, you could you could do that + + align:start position:0% +Oh. Oh. Uh, you could you could do that + + + align:start position:0% +Oh. Oh. Uh, you could you could do that +if you were completely confused like me. + + align:start position:0% +if you were completely confused like me. + + + align:start position:0% +if you were completely confused like me. +Um, so right. So x to the minus2 it + + align:start position:0% +Um, so right. So x to the minus2 it + + + align:start position:0% +Um, so right. So x to the minus2 it +increase by one increases by one. So + + align:start position:0% +increase by one increases by one. So + + + align:start position:0% +increase by one increases by one. So +when it increases by one you get minus + + align:start position:0% +when it increases by one you get minus + + + align:start position:0% +when it increases by one you get minus +one notus 3. Oh okay good. So this is -3 + + align:start position:0% +one notus 3. Oh okay good. So this is -3 + + + align:start position:0% +one notus 3. Oh okay good. So this is -3 +* x to the minus1 over minus1. Okay + + align:start position:0% +* x to the minus1 over minus1. Okay + + + align:start position:0% +* x to the minus1 over minus1. Okay +that's much better. And if you like + + align:start position:0% +that's much better. And if you like + + + align:start position:0% +that's much better. And if you like +right. So okay. Okay, so we could any + + align:start position:0% +right. So okay. Okay, so we could any + + + align:start position:0% +right. So okay. Okay, so we could any +any constant we add to this, it'll still + + align:start position:0% +any constant we add to this, it'll still + + + align:start position:0% +any constant we add to this, it'll still +be an anti-derivative. Okay, and now we + + align:start position:0% +be an anti-derivative. Okay, and now we + + + align:start position:0% +be an anti-derivative. Okay, and now we +could do a little bit of arithmetic to + + align:start position:0% +could do a little bit of arithmetic to + + + align:start position:0% +could do a little bit of arithmetic to +to rearrange this into nicer forms if + + align:start position:0% +to rearrange this into nicer forms if + + + align:start position:0% +to rearrange this into nicer forms if +you wanted. So you could rewrite this as + + align:start position:0% +you wanted. So you could rewrite this as + + + align:start position:0% +you wanted. So you could rewrite this as +say x to the 7th over 7 + + align:start position:0% +say x to the 7th over 7 + + + align:start position:0% +say x to the 7th over 7 ++ x^2 + + align:start position:0% + + + + align:start position:0% + ++ 3x^ + + align:start position:0% ++ 3x^ + + + align:start position:0% ++ 3x^ +- 1/3 + + align:start position:0% + + + + align:start position:0% + ++ 3xus + + align:start position:0% ++ 3xus + + + align:start position:0% ++ 3xus +1 plus a constant. Now suppose you got + + align:start position:0% +1 plus a constant. Now suppose you got + + + align:start position:0% +1 plus a constant. Now suppose you got +here and suppose that you know you did + + align:start position:0% +here and suppose that you know you did + + + align:start position:0% +here and suppose that you know you did +the same mistake that I just made um and + + align:start position:0% +the same mistake that I just made um and + + + align:start position:0% +the same mistake that I just made um and +you and you had accidentally thought + + align:start position:0% +you and you had accidentally thought + + + align:start position:0% +you and you had accidentally thought +that this was going to be a minus3 power + + align:start position:0% +that this was going to be a minus3 power + + + align:start position:0% +that this was going to be a minus3 power +instead of a minus 1st power. So how + + align:start position:0% +instead of a minus 1st power. So how + + + align:start position:0% +instead of a minus 1st power. So how +would you is there is there any way that + + align:start position:0% +would you is there is there any way that + + + align:start position:0% +would you is there is there any way that +you can prevent yourself making that + + align:start position:0% +you can prevent yourself making that + + + align:start position:0% +you can prevent yourself making that +mistake? Well, there actually is. So one + + align:start position:0% +mistake? Well, there actually is. So one + + + align:start position:0% +mistake? Well, there actually is. So one +nice thing about anti-derivatives is + + align:start position:0% +nice thing about anti-derivatives is + + + align:start position:0% +nice thing about anti-derivatives is +that it's really easy to check your work + + align:start position:0% +that it's really easy to check your work + + + align:start position:0% +that it's really easy to check your work +after you've computed an anti-derivative + + align:start position:0% +after you've computed an anti-derivative + + + align:start position:0% +after you've computed an anti-derivative +or or something that you think is an + + align:start position:0% +or or something that you think is an + + + align:start position:0% +or or something that you think is an +anti-derivative. you can always go back + + align:start position:0% +anti-derivative. you can always go back + + + align:start position:0% +anti-derivative. you can always go back +and take the derivative of the thing + + align:start position:0% +and take the derivative of the thing + + + align:start position:0% +and take the derivative of the thing +that you've computed and check that it's + + align:start position:0% +that you've computed and check that it's + + + align:start position:0% +that you've computed and check that it's +equal to what you started with. So if + + align:start position:0% +equal to what you started with. So if + + + align:start position:0% +equal to what you started with. So if +you if you're if you're ever worried + + align:start position:0% +you if you're if you're ever worried + + + align:start position:0% +you if you're if you're ever worried +that you made a mistake computing an + + align:start position:0% +that you made a mistake computing an + + + align:start position:0% +that you made a mistake computing an +anti-derivative, one thing you can + + align:start position:0% +anti-derivative, one thing you can + + + align:start position:0% +anti-derivative, one thing you can +always do is take a derivative of what + + align:start position:0% +always do is take a derivative of what + + + align:start position:0% +always do is take a derivative of what +you've got at the end. So if we take a + + align:start position:0% +you've got at the end. So if we take a + + + align:start position:0% +you've got at the end. So if we take a +derivative here, we get x 6 + 2x - x - + + align:start position:0% +derivative here, we get x 6 + 2x - x - + + + align:start position:0% +derivative here, we get x 6 + 2x - x - +4/3 - 3xus 2. Okay, so that was just + + align:start position:0% +4/3 - 3xus 2. Okay, so that was just + + + align:start position:0% +4/3 - 3xus 2. Okay, so that was just +using our our rule for powers one by one + + align:start position:0% +using our our rule for powers one by one + + + align:start position:0% +using our our rule for powers one by one +and okay, so you say that out loud or + + align:start position:0% +and okay, so you say that out loud or + + + align:start position:0% +and okay, so you say that out loud or +write it down and then you just check, + + align:start position:0% +write it down and then you just check, + + + align:start position:0% +write it down and then you just check, +right? So, so I said that. So that's + + align:start position:0% +right? So, so I said that. So that's + + + align:start position:0% +right? So, so I said that. So that's +exactly the same thing we've got right + + align:start position:0% +exactly the same thing we've got right + + + align:start position:0% +exactly the same thing we've got right +here. Yeah. So, so x 6 + 2x - x - 4/3 - + + align:start position:0% +here. Yeah. So, so x 6 + 2x - x - 4/3 - + + + align:start position:0% +here. Yeah. So, so x 6 + 2x - x - 4/3 - +3xus 2. So, + + align:start position:0% +3xus 2. So, + + + align:start position:0% +3xus 2. So, +one of the nicest things about + + align:start position:0% +one of the nicest things about + + + align:start position:0% +one of the nicest things about +anti-derivatives, they can be difficult + + align:start position:0% +anti-derivatives, they can be difficult + + + align:start position:0% +anti-derivatives, they can be difficult +to to figure out in the first place, but + + align:start position:0% +to to figure out in the first place, but + + + align:start position:0% +to to figure out in the first place, but +after you've got something that you + + align:start position:0% +after you've got something that you + + + align:start position:0% +after you've got something that you +think is an anti-derivative, it's very + + align:start position:0% +think is an anti-derivative, it's very + + + align:start position:0% +think is an anti-derivative, it's very +easy to go back and check whether you + + align:start position:0% +easy to go back and check whether you + + + align:start position:0% +easy to go back and check whether you +did it correctly by taking the + + align:start position:0% +did it correctly by taking the + + + align:start position:0% +did it correctly by taking the +derivative and making sure that it + + align:start position:0% +derivative and making sure that it + + + align:start position:0% +derivative and making sure that it +matches the the the, you know, the the + + align:start position:0% +matches the the the, you know, the the + + + align:start position:0% +matches the the the, you know, the the +thing that you were trying to + + align:start position:0% +thing that you were trying to + + + align:start position:0% +thing that you were trying to +anti-ifferiate at the beginning. So, + + align:start position:0% +anti-ifferiate at the beginning. So, + + + align:start position:0% +anti-ifferiate at the beginning. So, +that's that. \ No newline at end of file diff --git a/w3HgjULieFA.txt b/w3HgjULieFA.txt new file mode 100644 index 0000000000000000000000000000000000000000..0d294bb4c2a26548ae9dbd03fe4a778042dbcf6b --- /dev/null +++ b/w3HgjULieFA.txt @@ -0,0 +1,15587 @@ +align:start position:0% + +right so today we are going to start a + + align:start position:0% +right so today we are going to start a + + + align:start position:0% +right so today we are going to start a +series of several uh lectures on + + align:start position:0% +series of several uh lectures on + + + align:start position:0% +series of several uh lectures on +refractive index Diagnostics so these + + align:start position:0% +refractive index Diagnostics so these + + + align:start position:0% +refractive index Diagnostics so these +are Diagnostics which use the fact that + + align:start position:0% +are Diagnostics which use the fact that + + + align:start position:0% +are Diagnostics which use the fact that +the refractive index of a plasma is not + + align:start position:0% +the refractive index of a plasma is not + + + align:start position:0% +the refractive index of a plasma is not +one uh in order to make measurements + + align:start position:0% +one uh in order to make measurements + + + align:start position:0% +one uh in order to make measurements +about the plasma so first of all what + + align:start position:0% +about the plasma so first of all what + + + align:start position:0% +about the plasma so first of all what +we're going to do is a very quick recap + + align:start position:0% +we're going to do is a very quick recap + + + align:start position:0% +we're going to do is a very quick recap +of electromagnetic + + align:start position:0% +of electromagnetic + + + align:start position:0% +of electromagnetic +waves in a + + align:start position:0% + + + + align:start position:0% + +plasma and you have doubtless seen this + + align:start position:0% +plasma and you have doubtless seen this + + + align:start position:0% +plasma and you have doubtless seen this +before in some courses that you've done + + align:start position:0% +before in some courses that you've done + + + align:start position:0% +before in some courses that you've done +like it's in Chen um there's also a very + + align:start position:0% +like it's in Chen um there's also a very + + + align:start position:0% +like it's in Chen um there's also a very +good expanation of it in Hutchinson um + + align:start position:0% +good expanation of it in Hutchinson um + + + align:start position:0% +good expanation of it in Hutchinson um +and I am going to give like a little + + align:start position:0% +and I am going to give like a little + + + align:start position:0% +and I am going to give like a little +taster of how this derivation goes just + + align:start position:0% +taster of how this derivation goes just + + + align:start position:0% +taster of how this derivation goes just +to sort of remind folks of how this + + align:start position:0% +to sort of remind folks of how this + + + align:start position:0% +to sort of remind folks of how this +actually this result actually comes + + align:start position:0% +actually this result actually comes + + + align:start position:0% +actually this result actually comes +about and I'm going to do it in a rather + + align:start position:0% +about and I'm going to do it in a rather + + + align:start position:0% +about and I'm going to do it in a rather +restrictive way here so that we can make + + align:start position:0% +restrictive way here so that we can make + + + align:start position:0% +restrictive way here so that we can make +some rapid progress and we'll go back + + align:start position:0% +some rapid progress and we'll go back + + + align:start position:0% +some rapid progress and we'll go back +and add in more bits of theory later on + + align:start position:0% +and add in more bits of theory later on + + + align:start position:0% +and add in more bits of theory later on +as we need it okay so for our + + align:start position:0% +as we need it okay so for our + + + align:start position:0% +as we need it okay so for our +electromagnetic waves in a plasma we + + align:start position:0% +electromagnetic waves in a plasma we + + + align:start position:0% +electromagnetic waves in a plasma we +have two fields we have e and B like + + align:start position:0% +have two fields we have e and B like + + + align:start position:0% +have two fields we have e and B like +this and we have Maxell + + align:start position:0% + + + + align:start position:0% + +equations so we have that the curl of e + + align:start position:0% +equations so we have that the curl of e + + + align:start position:0% +equations so we have that the curl of e +is equal to minus B Dot and we have c^2 + + align:start position:0% +is equal to minus B Dot and we have c^2 + + + align:start position:0% +is equal to minus B Dot and we have c^2 +* the the curl of b + + align:start position:0% +* the the curl of b + + + align:start position:0% +* the the curl of b +equals e dot plus J over Epsilon KN you + + align:start position:0% +equals e dot plus J over Epsilon KN you + + + align:start position:0% +equals e dot plus J over Epsilon KN you +might be more used to seeing this + + align:start position:0% +might be more used to seeing this + + + align:start position:0% +might be more used to seeing this +equation with a mu I just mov the c s + + align:start position:0% +equation with a mu I just mov the c s + + + align:start position:0% +equation with a mu I just mov the c s +over the other side because it makes the + + align:start position:0% +over the other side because it makes the + + + align:start position:0% +over the other side because it makes the +math a little bit easier on the next + + align:start position:0% +math a little bit easier on the next + + + align:start position:0% +math a little bit easier on the next +step + + align:start position:0% +step + + + align:start position:0% +step +here and so these equations are just + + align:start position:0% +here and so these equations are just + + + align:start position:0% +here and so these equations are just +true they're true in any medium um and + + align:start position:0% +true they're true in any medium um and + + + align:start position:0% +true they're true in any medium um and +so what we want to do is try and reduce + + align:start position:0% +so what we want to do is try and reduce + + + align:start position:0% +so what we want to do is try and reduce +them down a little bit and then put some + + align:start position:0% +them down a little bit and then put some + + + align:start position:0% +them down a little bit and then put some +plasma physics in so the first thing we + + align:start position:0% +plasma physics in so the first thing we + + + align:start position:0% +plasma physics in so the first thing we +normally do when we're D deriving + + align:start position:0% +normally do when we're D deriving + + + align:start position:0% +normally do when we're D deriving +electromagnetic waves is we say what if + + align:start position:0% +electromagnetic waves is we say what if + + + align:start position:0% +electromagnetic waves is we say what if +all of our vectors um had some sort of + + align:start position:0% +all of our vectors um had some sort of + + + align:start position:0% +all of our vectors um had some sort of +time and space variation that looked + + align:start position:0% +time and space variation that looked + + + align:start position:0% +time and space variation that looked +like exponential of I some wave vector k + + align:start position:0% +like exponential of I some wave vector k + + + align:start position:0% +like exponential of I some wave vector k +do some position Vector x minus Omega + + align:start position:0% +do some position Vector x minus Omega + + + align:start position:0% +do some position Vector x minus Omega +the frequency time time like that and so + + align:start position:0% +the frequency time time like that and so + + + align:start position:0% +the frequency time time like that and so +this is a little bit like Foria + + align:start position:0% +this is a little bit like Foria + + + align:start position:0% +this is a little bit like Foria +Transforming Our equations here and we + + align:start position:0% +Transforming Our equations here and we + + + align:start position:0% +Transforming Our equations here and we +end up with oh + + align:start position:0% +end up with oh + + + align:start position:0% +end up with oh +uh K cross E equals I + + align:start position:0% +uh K cross E equals I + + + align:start position:0% +uh K cross E equals I +Omega B and we have c^ 2 K cross B = + + align:start position:0% +Omega B and we have c^ 2 K cross B = + + + align:start position:0% +Omega B and we have c^ 2 K cross B = +minus I + + align:start position:0% +minus I + + + align:start position:0% +minus I +Omega e plus J upon Epsilon and the + + align:start position:0% +Omega e plus J upon Epsilon and the + + + align:start position:0% +Omega e plus J upon Epsilon and the +astute amongst you have noticed I made a + + align:start position:0% +astute amongst you have noticed I made a + + + align:start position:0% +astute amongst you have noticed I made a +sign error in the first equation here so + + align:start position:0% +sign error in the first equation here so + + + align:start position:0% +sign error in the first equation here so +this is plus I Omega B not + + align:start position:0% +this is plus I Omega B not + + + align:start position:0% +this is plus I Omega B not +okay very good and so we could call + + align:start position:0% +okay very good and so we could call + + + align:start position:0% +okay very good and so we could call +these equations one and two and we can + + align:start position:0% +these equations one and two and we can + + + align:start position:0% +these equations one and two and we can +note that if we do K cross with equation + + align:start position:0% +note that if we do K cross with equation + + + align:start position:0% +note that if we do K cross with equation +one that is equal to iega upon c^2 of + + align:start position:0% +one that is equal to iega upon c^2 of + + + align:start position:0% +one that is equal to iega upon c^2 of +equation two so what we're doing here is + + align:start position:0% +equation two so what we're doing here is + + + align:start position:0% +equation two so what we're doing here is +we're just looking at this term and this + + align:start position:0% +we're just looking at this term and this + + + align:start position:0% +we're just looking at this term and this +term and being like hey they've both got + + align:start position:0% +term and being like hey they've both got + + + align:start position:0% +term and being like hey they've both got +B in them we can probably make them look + + align:start position:0% +B in them we can probably make them look + + + align:start position:0% +B in them we can probably make them look +the same so then we can equate we can do + + align:start position:0% +the same so then we can equate we can do + + + align:start position:0% +the same so then we can equate we can do +this calcul we can equate the two sides + + align:start position:0% +this calcul we can equate the two sides + + + align:start position:0% +this calcul we can equate the two sides +of the equation and with a little bit of + + align:start position:0% +of the equation and with a little bit of + + + align:start position:0% +of the equation and with a little bit of +vector magic Vector calculus magic we + + align:start position:0% +vector magic Vector calculus magic we + + + align:start position:0% +vector magic Vector calculus magic we +would end up with something that looks + + align:start position:0% +would end up with something that looks + + + align:start position:0% +would end up with something that looks +like k k dot + + align:start position:0% +like k k dot + + + align:start position:0% +like k k dot +e plus k^ + + align:start position:0% +e plus k^ + + + align:start position:0% +e plus k^ +2 e is equal + + align:start position:0% +2 e is equal + + + align:start position:0% +2 e is equal +to I Omega J over Epsilon c^ 2 plus + + align:start position:0% +to I Omega J over Epsilon c^ 2 plus + + + align:start position:0% +to I Omega J over Epsilon c^ 2 plus +Omega 2 upon c^ 2 + + align:start position:0% +Omega 2 upon c^ 2 + + + align:start position:0% +Omega 2 upon c^ 2 +e like + + align:start position:0% +e like + + + align:start position:0% +e like +that now we are searching for transverse + + align:start position:0% +that now we are searching for transverse + + + align:start position:0% +that now we are searching for transverse +waves here electromagnetic waves that + + align:start position:0% +waves here electromagnetic waves that + + + align:start position:0% +waves here electromagnetic waves that +tend to be transverse and that means + + align:start position:0% +tend to be transverse and that means + + + align:start position:0% +tend to be transverse and that means +that k. e is zero so we're just going to + + align:start position:0% +that k. e is zero so we're just going to + + + align:start position:0% +that k. e is zero so we're just going to +look for transverse wave Solutions + + align:start position:0% +look for transverse wave Solutions + + + align:start position:0% +look for transverse wave Solutions +here we can drop that and that means + + align:start position:0% +here we can drop that and that means + + + align:start position:0% +here we can drop that and that means +that our equation can be Rewritten as + + align:start position:0% +that our equation can be Rewritten as + + + align:start position:0% +that our equation can be Rewritten as +Omega 2 minus c^ 2 k^ 2 * + + align:start position:0% +Omega 2 minus c^ 2 k^ 2 * + + + align:start position:0% +Omega 2 minus c^ 2 k^ 2 * +E equals minus I + + align:start position:0% +E equals minus I + + + align:start position:0% +E equals minus I +Omega + + align:start position:0% +Omega + + + align:start position:0% +Omega +J upon + + align:start position:0% +J upon + + + align:start position:0% +J upon +Epsilon like that and I just want to + + align:start position:0% +Epsilon like that and I just want to + + + align:start position:0% +Epsilon like that and I just want to +point out there's absolutely no plasma + + align:start position:0% +point out there's absolutely no plasma + + + align:start position:0% +point out there's absolutely no plasma +physics in this at the moment right all + + align:start position:0% +physics in this at the moment right all + + + align:start position:0% +physics in this at the moment right all +we've done is manipulate maximal + + align:start position:0% +we've done is manipulate maximal + + + align:start position:0% +we've done is manipulate maximal +equations we haven't said anything about + + align:start position:0% +equations we haven't said anything about + + + align:start position:0% +equations we haven't said anything about +the planting so if I take a standard + + align:start position:0% +the planting so if I take a standard + + + align:start position:0% +the planting so if I take a standard +limit here say I let the current equal + + align:start position:0% +limit here say I let the current equal + + + align:start position:0% +limit here say I let the current equal +zero which is what would be in the + + align:start position:0% +zero which is what would be in the + + + align:start position:0% +zero which is what would be in the +vacuum of space where there's no + + align:start position:0% +vacuum of space where there's no + + + align:start position:0% +vacuum of space where there's no +particles to carry any current then we' + + align:start position:0% +particles to carry any current then we' + + + align:start position:0% +particles to carry any current then we' +simply send up end up with an equation + + align:start position:0% +simply send up end up with an equation + + + align:start position:0% +simply send up end up with an equation +for light INF space and it would have a + + align:start position:0% +for light INF space and it would have a + + + align:start position:0% +for light INF space and it would have a +dispersion relationship Omega s = c^2 k + + align:start position:0% +dispersion relationship Omega s = c^2 k + + + align:start position:0% +dispersion relationship Omega s = c^2 k +s like that so those are light waves so + + align:start position:0% +s like that so those are light waves so + + + align:start position:0% +s like that so those are light waves so +life is + + align:start position:0% +life is + + + align:start position:0% +life is +good any questions on that before we put + + align:start position:0% +good any questions on that before we put + + + align:start position:0% +good any questions on that before we put +some plasma + + align:start position:0% + + + + align:start position:0% + +physics hopefully you're dredging up + + align:start position:0% +physics hopefully you're dredging up + + + align:start position:0% +physics hopefully you're dredging up +your memories of Griffiths and Jackson + + align:start position:0% +your memories of Griffiths and Jackson + + + align:start position:0% +your memories of Griffiths and Jackson +and all sorts of wonderful things like + + align:start position:0% +and all sorts of wonderful things like + + + align:start position:0% +and all sorts of wonderful things like +this this is all making sense so let's + + align:start position:0% +this this is all making sense so let's + + + align:start position:0% +this this is all making sense so let's +keep going + + align:start position:0% + + + + align:start position:0% + +uh the next thing we want to do then is + + align:start position:0% +uh the next thing we want to do then is + + + align:start position:0% +uh the next thing we want to do then is +add in some plasma physics and we're + + align:start position:0% +add in some plasma physics and we're + + + align:start position:0% +add in some plasma physics and we're +going to add in some plasma physics with + + align:start position:0% +going to add in some plasma physics with + + + align:start position:0% +going to add in some plasma physics with +some serious assumptions which let us + + align:start position:0% +some serious assumptions which let us + + + align:start position:0% +some serious assumptions which let us +make significant progress quickly uh and + + align:start position:0% +make significant progress quickly uh and + + + align:start position:0% +make significant progress quickly uh and +these assumptions can all be justified + + align:start position:0% +these assumptions can all be justified + + + align:start position:0% +these assumptions can all be justified +uh for most plasmas um and if you can't + + align:start position:0% +uh for most plasmas um and if you can't + + + align:start position:0% +uh for most plasmas um and if you can't +justify it for your plasma you may want + + align:start position:0% +justify it for your plasma you may want + + + align:start position:0% +justify it for your plasma you may want +to revisit these a little bit okay so + + align:start position:0% +to revisit these a little bit okay so + + + align:start position:0% +to revisit these a little bit okay so +the first assumption we're going to make + + align:start position:0% +the first assumption we're going to make + + + align:start position:0% +the first assumption we're going to make +is that we're at using high frequency + + align:start position:0% +is that we're at using high frequency + + + align:start position:0% +is that we're at using high frequency +waves here here and high frequency this + + align:start position:0% +waves here here and high frequency this + + + align:start position:0% +waves here here and high frequency this +is kind of a wishy-washy term uh we want + + align:start position:0% +is kind of a wishy-washy term uh we want + + + align:start position:0% +is kind of a wishy-washy term uh we want +to make that more precise by having a + + align:start position:0% +to make that more precise by having a + + + align:start position:0% +to make that more precise by having a +dimensionless parameter and so we're + + align:start position:0% +dimensionless parameter and so we're + + + align:start position:0% +dimensionless parameter and so we're +going to say that Omega is much much + + align:start position:0% +going to say that Omega is much much + + + align:start position:0% +going to say that Omega is much much +larger larger than Omega Pi here so the + + align:start position:0% +larger larger than Omega Pi here so the + + + align:start position:0% +larger larger than Omega Pi here so the +frequency of our waves is much higher + + align:start position:0% +frequency of our waves is much higher + + + align:start position:0% +frequency of our waves is much higher +than the uh ion plasma frequency what + + align:start position:0% +than the uh ion plasma frequency what + + + align:start position:0% +than the uh ion plasma frequency what +does that condition physically respond + + align:start position:0% +does that condition physically respond + + + align:start position:0% +does that condition physically respond +to what are we saying about the ions and + + align:start position:0% +to what are we saying about the ions and + + + align:start position:0% +to what are we saying about the ions and +their interaction with this Wave by + + align:start position:0% +their interaction with this Wave by + + + align:start position:0% +their interaction with this Wave by +putting this condition in + + align:start position:0% + + + + align:start position:0% + +well you're saying you're saying they + + align:start position:0% +well you're saying you're saying they + + + align:start position:0% +well you're saying you're saying they +essentially don't interact at that point + + align:start position:0% +essentially don't interact at that point + + + align:start position:0% +essentially don't interact at that point +yeah so the ions are frozen in + + align:start position:0% +yeah so the ions are frozen in + + + align:start position:0% +yeah so the ions are frozen in +place and they are not going to + + align:start position:0% +place and they are not going to + + + align:start position:0% +place and they are not going to +participate in any of the physics that + + align:start position:0% +participate in any of the physics that + + + align:start position:0% +participate in any of the physics that +we're interested in here and again you + + align:start position:0% +we're interested in here and again you + + + align:start position:0% +we're interested in here and again you +can work out the ion plasma frequency + + align:start position:0% +can work out the ion plasma frequency + + + align:start position:0% +can work out the ion plasma frequency +for um you know some density that you're + + align:start position:0% +for um you know some density that you're + + + align:start position:0% +for um you know some density that you're +interested in and you'll find out it's + + align:start position:0% +interested in and you'll find out it's + + + align:start position:0% +interested in and you'll find out it's +pretty low so this is kind of pretty + + align:start position:0% +pretty low so this is kind of pretty + + + align:start position:0% +pretty low so this is kind of pretty +reasonable but if you start using very + + align:start position:0% +reasonable but if you start using very + + + align:start position:0% +reasonable but if you start using very +low frequency waves it won't be + + align:start position:0% +low frequency waves it won't be + + + align:start position:0% +low frequency waves it won't be +reasonable so another thing that we're + + align:start position:0% +reasonable so another thing that we're + + + align:start position:0% +reasonable so another thing that we're +going to do is make the cold plasma + + align:start position:0% + + + + align:start position:0% + +approximation and again we can't just + + align:start position:0% +approximation and again we can't just + + + align:start position:0% +approximation and again we can't just +use the word cold we have to say what we + + align:start position:0% +use the word cold we have to say what we + + + align:start position:0% +use the word cold we have to say what we +mean by cold and we're going to say the + + align:start position:0% +mean by cold and we're going to say the + + + align:start position:0% +mean by cold and we're going to say the +thermal of the electrons is much much + + align:start position:0% +thermal of the electrons is much much + + + align:start position:0% +thermal of the electrons is much much +less than the speed of light here and + + align:start position:0% +less than the speed of light here and + + + align:start position:0% +less than the speed of light here and +this condition is equivalent to us not + + align:start position:0% +this condition is equivalent to us not + + + align:start position:0% +this condition is equivalent to us not +worrying about the maxwan distribution + + align:start position:0% +worrying about the maxwan distribution + + + align:start position:0% +worrying about the maxwan distribution +of the electron so all the electrons are + + align:start position:0% +of the electron so all the electrons are + + + align:start position:0% +of the electron so all the electrons are +just going to sort of be moving with no + + align:start position:0% +just going to sort of be moving with no + + + align:start position:0% +just going to sort of be moving with no +they will be moving unlike the ions + + align:start position:0% +they will be moving unlike the ions + + + align:start position:0% +they will be moving unlike the ions +which are frozen but they will be moving + + align:start position:0% +which are frozen but they will be moving + + + align:start position:0% +which are frozen but they will be moving +uh all at the same speed there's no + + align:start position:0% +uh all at the same speed there's no + + + align:start position:0% +uh all at the same speed there's no +spread of velocities here so um we have + + align:start position:0% +spread of velocities here so um we have + + + align:start position:0% +spread of velocities here so um we have +like a Delta function of velocities and + + align:start position:0% +like a Delta function of velocities and + + + align:start position:0% +like a Delta function of velocities and +we do not + + align:start position:0% +we do not + + + align:start position:0% +we do not +have our maxwan distribution that we + + align:start position:0% +have our maxwan distribution that we + + + align:start position:0% +have our maxwan distribution that we +might normally think + + align:start position:0% +might normally think + + + align:start position:0% +might normally think +about and the final condition we're + + align:start position:0% +about and the final condition we're + + + align:start position:0% +about and the final condition we're +going to write down is + + align:start position:0% +going to write down is + + + align:start position:0% +going to write down is +unmagnetized now this is the one which I + + align:start position:0% +unmagnetized now this is the one which I + + + align:start position:0% +unmagnetized now this is the one which I +think is most complicated because in + + align:start position:0% +think is most complicated because in + + + align:start position:0% +think is most complicated because in +fact there are like a dozen different + + align:start position:0% +fact there are like a dozen different + + + align:start position:0% +fact there are like a dozen different +ways you can write down a dimensionist + + align:start position:0% +ways you can write down a dimensionist + + + align:start position:0% +ways you can write down a dimensionist +parameter for unmagnetized and they all + + align:start position:0% +parameter for unmagnetized and they all + + + align:start position:0% +parameter for unmagnetized and they all +mean subtly different things we could + + align:start position:0% +mean subtly different things we could + + + align:start position:0% +mean subtly different things we could +think about collisionality we could + + align:start position:0% +think about collisionality we could + + + align:start position:0% +think about collisionality we could +think about pressure balance all sorts + + align:start position:0% +think about pressure balance all sorts + + + align:start position:0% +think about pressure balance all sorts +of things like that for the purposes of + + align:start position:0% +of things like that for the purposes of + + + align:start position:0% +of things like that for the purposes of +this derivation unmagnetized means Omega + + align:start position:0% +this derivation unmagnetized means Omega + + + align:start position:0% +this derivation unmagnetized means Omega +is much much larger than Capital Omega I + + align:start position:0% +is much much larger than Capital Omega I + + + align:start position:0% +is much much larger than Capital Omega I +know it's confusing and I'll put a + + align:start position:0% +know it's confusing and I'll put a + + + align:start position:0% +know it's confusing and I'll put a +little subscript e here because we've + + align:start position:0% +little subscript e here because we've + + + align:start position:0% +little subscript e here because we've +Frozen the ions but this is the gyro + + align:start position:0% +Frozen the ions but this is the gyro + + + align:start position:0% +Frozen the ions but this is the gyro +motion of the electrons so the electrons + + align:start position:0% +motion of the electrons so the electrons + + + align:start position:0% +motion of the electrons so the electrons +may be gyrating around field lines there + + align:start position:0% +may be gyrating around field lines there + + + align:start position:0% +may be gyrating around field lines there +may be some magnetic field it doesn't + + align:start position:0% +may be some magnetic field it doesn't + + + align:start position:0% +may be some magnetic field it doesn't +have to be zero but on the time scale + + align:start position:0% +have to be zero but on the time scale + + + align:start position:0% +have to be zero but on the time scale +that the wave goes B and does its stuff + + align:start position:0% +that the wave goes B and does its stuff + + + align:start position:0% +that the wave goes B and does its stuff +the electrons do not move appreciably + + align:start position:0% +the electrons do not move appreciably + + + align:start position:0% +the electrons do not move appreciably +around their gyro orbit so we don't have + + align:start position:0% +around their gyro orbit so we don't have + + + align:start position:0% +around their gyro orbit so we don't have +to care about their gyro motion this is + + align:start position:0% +to care about their gyro motion this is + + + align:start position:0% +to care about their gyro motion this is +one of the places we will definitely + + align:start position:0% +one of the places we will definitely + + + align:start position:0% +one of the places we will definitely +have to relax later on when we want to + + align:start position:0% +have to relax later on when we want to + + + align:start position:0% +have to relax later on when we want to +do Faraday rotation Imaging which relies + + align:start position:0% +do Faraday rotation Imaging which relies + + + align:start position:0% +do Faraday rotation Imaging which relies +on that gyro motion to give us the + + align:start position:0% +on that gyro motion to give us the + + + align:start position:0% +on that gyro motion to give us the +effect okay so this is the final + + align:start position:0% +effect okay so this is the final + + + align:start position:0% +effect okay so this is the final +condition any questions on those three + + align:start position:0% + + + + align:start position:0% + +assumptions okay so then we can write + + align:start position:0% +assumptions okay so then we can write + + + align:start position:0% +assumptions okay so then we can write +down that the current + + align:start position:0% +down that the current + + + align:start position:0% +down that the current +inside our plasma is simply going to be + + align:start position:0% +inside our plasma is simply going to be + + + align:start position:0% +inside our plasma is simply going to be +equal to the charge on the electrons the + + align:start position:0% +equal to the charge on the electrons the + + + align:start position:0% +equal to the charge on the electrons the +number of electrons and how fast they're + + align:start position:0% +number of electrons and how fast they're + + + align:start position:0% +number of electrons and how fast they're +moving and so we've simply transferred + + align:start position:0% +moving and so we've simply transferred + + + align:start position:0% +moving and so we've simply transferred +our lack of knowledge about J into our + + align:start position:0% +our lack of knowledge about J into our + + + align:start position:0% +our lack of knowledge about J into our +lack of knowledge about V so we better + + align:start position:0% +lack of knowledge about V so we better + + + align:start position:0% +lack of knowledge about V so we better +do something about that and we're going + + align:start position:0% +do something about that and we're going + + + align:start position:0% +do something about that and we're going +to do that using the electron equation + + align:start position:0% +to do that using the electron equation + + + align:start position:0% +to do that using the electron equation +of motion and that electron equation of + + align:start position:0% +of motion and that electron equation of + + + align:start position:0% +of motion and that electron equation of +motion looks like M dve DT is equal to + + align:start position:0% +motion looks like M dve DT is equal to + + + align:start position:0% +motion looks like M dve DT is equal to +minus E the charge times capital e the + + align:start position:0% +minus E the charge times capital e the + + + align:start position:0% +minus E the charge times capital e the +vector electric field like + + align:start position:0% +vector electric field like + + + align:start position:0% +vector electric field like +that okay so we could rearrange that so + + align:start position:0% +that okay so we could rearrange that so + + + align:start position:0% +that okay so we could rearrange that so +that we have V is equal to + + align:start position:0% +that we have V is equal to + + + align:start position:0% +that we have V is equal to +e Vector e over I Omega we've done the + + align:start position:0% +e Vector e over I Omega we've done the + + + align:start position:0% +e Vector e over I Omega we've done the +same for transform trick that we did + + align:start position:0% +same for transform trick that we did + + + align:start position:0% +same for transform trick that we did +with all the other quantities we assume + + align:start position:0% +with all the other quantities we assume + + + align:start position:0% +with all the other quantities we assume +it's going to be oscillating in some way + + align:start position:0% +it's going to be oscillating in some way + + + align:start position:0% +it's going to be oscillating in some way +substitute that back into our equation + + align:start position:0% +substitute that back into our equation + + + align:start position:0% +substitute that back into our equation +for e and we'll get Omega s minus c^ 2 + + align:start position:0% +for e and we'll get Omega s minus c^ 2 + + + align:start position:0% +for e and we'll get Omega s minus c^ 2 +k^2 e as we had before is equal to NE + + align:start position:0% +k^2 e as we had before is equal to NE + + + align:start position:0% +k^2 e as we had before is equal to NE +e^2 + + align:start position:0% +e^2 + + + align:start position:0% +e^2 +over Epsilon + + align:start position:0% +over Epsilon + + + align:start position:0% +over Epsilon +me capital E sorry was there a question + + align:start position:0% +me capital E sorry was there a question + + + align:start position:0% +me capital E sorry was there a question +I had someone + + align:start position:0% +I had someone + + + align:start position:0% +I had someone +speak no that was an accident sorry oh + + align:start position:0% +speak no that was an accident sorry oh + + + align:start position:0% +speak no that was an accident sorry oh +no right all good um and just to be + + align:start position:0% +no right all good um and just to be + + + align:start position:0% +no right all good um and just to be +clear here this equation of motion + + align:start position:0% +clear here this equation of motion + + + align:start position:0% +clear here this equation of motion +doesn't have the uh V crossb term in it + + align:start position:0% +doesn't have the uh V crossb term in it + + + align:start position:0% +doesn't have the uh V crossb term in it +which should be like the magnetic field + + align:start position:0% +which should be like the magnetic field + + + align:start position:0% +which should be like the magnetic field +term because we've dropped it because + + align:start position:0% +term because we've dropped it because + + + align:start position:0% +term because we've dropped it because +we're making this uh unmagnetized + + align:start position:0% +we're making this uh unmagnetized + + + align:start position:0% +we're making this uh unmagnetized +approximation but that's where you put + + align:start position:0% +approximation but that's where you put + + + align:start position:0% +approximation but that's where you put +it back in you put in a little term that + + align:start position:0% +it back in you put in a little term that + + + align:start position:0% +it back in you put in a little term that +was like plus b cross B in here and put + + align:start position:0% +was like plus b cross B in here and put + + + align:start position:0% +was like plus b cross B in here and put +little brackets around but for now we're + + align:start position:0% +little brackets around but for now we're + + + align:start position:0% +little brackets around but for now we're +just setting that equal to zero okay + + align:start position:0% +just setting that equal to zero okay + + + align:start position:0% +just setting that equal to zero okay +good and the solution to this equation + + align:start position:0% +good and the solution to this equation + + + align:start position:0% +good and the solution to this equation +that we've got now is Omega s equals + + align:start position:0% +that we've got now is Omega s equals + + + align:start position:0% +that we've got now is Omega s equals +Omega p^ 2 plus c^ 2 K 2 so this looks + + align:start position:0% +Omega p^ 2 plus c^ 2 K 2 so this looks + + + align:start position:0% +Omega p^ 2 plus c^ 2 K 2 so this looks +an awful lot like what we had before + + align:start position:0% +an awful lot like what we had before + + + align:start position:0% +an awful lot like what we had before +which was just these two terms but now + + align:start position:0% +which was just these two terms but now + + + align:start position:0% +which was just these two terms but now +we've got this additional term which + + align:start position:0% +we've got this additional term which + + + align:start position:0% +we've got this additional term which +includes some plasma physics and I could + + align:start position:0% +includes some plasma physics and I could + + + align:start position:0% +includes some plasma physics and I could +write that this is omega PE s um and you + + align:start position:0% +write that this is omega PE s um and you + + + align:start position:0% +write that this is omega PE s um and you +know make it clear it's the electrons + + align:start position:0% +know make it clear it's the electrons + + + align:start position:0% +know make it clear it's the electrons +but remember we've dropped the IR motion + + align:start position:0% +but remember we've dropped the IR motion + + + align:start position:0% +but remember we've dropped the IR motion +already so there's only one uh plasma + + align:start position:0% +already so there's only one uh plasma + + + align:start position:0% +already so there's only one uh plasma +frequency that's very interesting the + + align:start position:0% +frequency that's very interesting the + + + align:start position:0% +frequency that's very interesting the +electron plasma frequency for this + + align:start position:0% +electron plasma frequency for this + + + align:start position:0% +electron plasma frequency for this +derivation + + align:start position:0% +derivation + + + align:start position:0% +derivation +here and then we can go ahead and do all + + align:start position:0% +here and then we can go ahead and do all + + + align:start position:0% +here and then we can go ahead and do all +the standard things we do with a + + align:start position:0% +the standard things we do with a + + + align:start position:0% +the standard things we do with a +um one of these uh functions which is to + + align:start position:0% +um one of these uh functions which is to + + + align:start position:0% +um one of these uh functions which is to +try and write down the phase velocity + + align:start position:0% +try and write down the phase velocity + + + align:start position:0% +try and write down the phase velocity +and the phase velocity squ is just equal + + align:start position:0% +and the phase velocity squ is just equal + + + align:start position:0% +and the phase velocity squ is just equal +to Omega 2 upon k^2 and so that means + + align:start position:0% +to Omega 2 upon k^2 and so that means + + + align:start position:0% +to Omega 2 upon k^2 and so that means +our phase velocity is C + + align:start position:0% +our phase velocity is C + + + align:start position:0% +our phase velocity is C +upon 1 minus Omega p ^ 2 upon Omega s so + + align:start position:0% +upon 1 minus Omega p ^ 2 upon Omega s so + + + align:start position:0% +upon 1 minus Omega p ^ 2 upon Omega s so +a + + align:start position:0% +a + + + align:start position:0% +a +half and then we can write down the + + align:start position:0% +half and then we can write down the + + + align:start position:0% +half and then we can write down the +refractive index because our refractive + + align:start position:0% +refractive index because our refractive + + + align:start position:0% +refractive index because our refractive +index capital N is just equal to C over + + align:start position:0% +index capital N is just equal to C over + + + align:start position:0% +index capital N is just equal to C over +the phase velocity and that is going to + + align:start position:0% +the phase velocity and that is going to + + + align:start position:0% +the phase velocity and that is going to +be equal to 1 - Omega p^ 2 over Omega 2 + + align:start position:0% +be equal to 1 - Omega p^ 2 over Omega 2 + + + align:start position:0% +be equal to 1 - Omega p^ 2 over Omega 2 +and we we often write this not in terms + + align:start position:0% +and we we often write this not in terms + + + align:start position:0% +and we we often write this not in terms +of frequencies but in terms of densities + + align:start position:0% +of frequencies but in terms of densities + + + align:start position:0% +of frequencies but in terms of densities +because the plasma frequency has inside + + align:start position:0% +because the plasma frequency has inside + + + align:start position:0% +because the plasma frequency has inside +it an electron density we write 1 minus + + align:start position:0% +it an electron density we write 1 minus + + + align:start position:0% +it an electron density we write 1 minus +NE Over N critical like this where n + + align:start position:0% +NE Over N critical like this where n + + + align:start position:0% +NE Over N critical like this where n +critical is some critical density and + + align:start position:0% +critical is some critical density and + + + align:start position:0% +critical is some critical density and +we'll get on to why it's so critical in + + align:start position:0% +we'll get on to why it's so critical in + + + align:start position:0% +we'll get on to why it's so critical in +a moment but if you want to approximate + + align:start position:0% +a moment but if you want to approximate + + + align:start position:0% +a moment but if you want to approximate +it then n critical in centimeters to + + align:start position:0% +it then n critical in centimeters to + + + align:start position:0% +it then n critical in centimeters to +minus 3 so particles per cubic + + align:start position:0% +minus 3 so particles per cubic + + + align:start position:0% +minus 3 so particles per cubic +centimeter is roughly 10 21 over Lambda + + align:start position:0% +centimeter is roughly 10 21 over Lambda + + + align:start position:0% +centimeter is roughly 10 21 over Lambda +when Lambda is in microns here so if + + align:start position:0% +when Lambda is in microns here so if + + + align:start position:0% +when Lambda is in microns here so if +you're using like a laser beam at one + + align:start position:0% +you're using like a laser beam at one + + + align:start position:0% +you're using like a laser beam at one +micron that would be a very standard + + align:start position:0% +micron that would be a very standard + + + align:start position:0% +micron that would be a very standard +laser wavelength from a near demium yag + + align:start position:0% +laser wavelength from a near demium yag + + + align:start position:0% +laser wavelength from a near demium yag +or near demium glass laser then you have + + align:start position:0% +or near demium glass laser then you have + + + align:start position:0% +or near demium glass laser then you have +a critical density about 10 to 21 which + + align:start position:0% +a critical density about 10 to 21 which + + + align:start position:0% +a critical density about 10 to 21 which +depending on which your field you're + + align:start position:0% +depending on which your field you're + + + align:start position:0% +depending on which your field you're +working in is either hilariously high + + align:start position:0% +working in is either hilariously high + + + align:start position:0% +working in is either hilariously high +and unreachable or crazy low and happens + + align:start position:0% +and unreachable or crazy low and happens + + + align:start position:0% +and unreachable or crazy low and happens +all the time so again this is one of the + + align:start position:0% +all the time so again this is one of the + + + align:start position:0% +all the time so again this is one of the +exciting things about doing plasma + + align:start position:0% +exciting things about doing plasma + + + align:start position:0% +exciting things about doing plasma +Diagnostics course where we span 60 OD + + align:start position:0% +Diagnostics course where we span 60 OD + + + align:start position:0% +Diagnostics course where we span 60 OD +of magnitude in density + + align:start position:0% +of magnitude in density + + + align:start position:0% +of magnitude in density +um any questions + + align:start position:0% +um any questions + + + align:start position:0% +um any questions +on yeah what's the critical density + + align:start position:0% +on yeah what's the critical density + + + align:start position:0% +on yeah what's the critical density +Point + + align:start position:0% +Point + + + align:start position:0% +Point +again as in what is its physical + + align:start position:0% +again as in what is its physical + + + align:start position:0% +again as in what is its physical +significance yeah like why why do you + + align:start position:0% +significance yeah like why why do you + + + align:start position:0% +significance yeah like why why do you +choose that number we're gonna we're + + align:start position:0% +choose that number we're gonna we're + + + align:start position:0% +choose that number we're gonna we're +gonna look look into that in a moment + + align:start position:0% +gonna look look into that in a moment + + + align:start position:0% +gonna look look into that in a moment +it's a good question it's a solid + + align:start position:0% +it's a good question it's a solid + + + align:start position:0% +it's a good question it's a solid +question but it's just to be clear I can + + align:start position:0% +question but it's just to be clear I can + + + align:start position:0% +question but it's just to be clear I can +the reason I've got there is I've taken + + align:start position:0% +the reason I've got there is I've taken + + + align:start position:0% +the reason I've got there is I've taken +this Omega p squ and this Omega squ and + + align:start position:0% +this Omega p squ and this Omega squ and + + + align:start position:0% +this Omega p squ and this Omega squ and +I've noticed that Omega p^ s has inside + + align:start position:0% +I've noticed that Omega p^ s has inside + + + align:start position:0% +I've noticed that Omega p^ s has inside +it + + align:start position:0% +it + + + align:start position:0% +it +the electron density and I've Rewritten + + align:start position:0% +the electron density and I've Rewritten + + + align:start position:0% +the electron density and I've Rewritten +all the other terms so uh this n + + align:start position:0% +all the other terms so uh this n + + + align:start position:0% +all the other terms so uh this n +critical now has inside it things like + + align:start position:0% +critical now has inside it things like + + + align:start position:0% +critical now has inside it things like +uh Omega squar I made a critical mistake + + align:start position:0% +uh Omega squar I made a critical mistake + + + align:start position:0% +uh Omega squar I made a critical mistake +in my equation up here this is Lambda + + align:start position:0% +in my equation up here this is Lambda + + + align:start position:0% +in my equation up here this is Lambda +squared here for approximating this in + + align:start position:0% +squared here for approximating this in + + + align:start position:0% +squared here for approximating this in +terms of sort of symol quantities so the + + align:start position:0% +terms of sort of symol quantities so the + + + align:start position:0% +terms of sort of symol quantities so the +the N critical now depends on the uh + + align:start position:0% +the N critical now depends on the uh + + + align:start position:0% +the N critical now depends on the uh +laser wavelength or the the frequency of + + align:start position:0% +laser wavelength or the the frequency of + + + align:start position:0% +laser wavelength or the the frequency of +your probing electromagnetic radiation + + align:start position:0% +your probing electromagnetic radiation + + + align:start position:0% +your probing electromagnetic radiation +so it's different for every frequency um + + align:start position:0% +so it's different for every frequency um + + + align:start position:0% +so it's different for every frequency um +but that's the only it depends on the + + align:start position:0% +but that's the only it depends on the + + + align:start position:0% +but that's the only it depends on the +rest of it is all like fundamental + + align:start position:0% +rest of it is all like fundamental + + + align:start position:0% +rest of it is all like fundamental +constants like e and the electron mass + + align:start position:0% +constants like e and the electron mass + + + align:start position:0% +constants like e and the electron mass +that don't change so this is a parameter + + align:start position:0% +that don't change so this is a parameter + + + align:start position:0% +that don't change so this is a parameter +there's a critical density for every + + align:start position:0% +there's a critical density for every + + + align:start position:0% +there's a critical density for every +single uh laser wavelength or + + align:start position:0% +single uh laser wavelength or + + + align:start position:0% +single uh laser wavelength or +electromagnetic wave frequency I'm going + + align:start position:0% +electromagnetic wave frequency I'm going + + + align:start position:0% +electromagnetic wave frequency I'm going +to talk about lasers a lot of course + + align:start position:0% +to talk about lasers a lot of course + + + align:start position:0% +to talk about lasers a lot of course +this also applies like mic waves and + + align:start position:0% +this also applies like mic waves and + + + align:start position:0% +this also applies like mic waves and +things like that as well but some sort + + align:start position:0% +things like that as well but some sort + + + align:start position:0% +things like that as well but some sort +of source of em radiation so I'm going + + align:start position:0% +of source of em radiation so I'm going + + + align:start position:0% +of source of em radiation so I'm going +to get on to what n critical is in in + + align:start position:0% +to get on to what n critical is in in + + + align:start position:0% +to get on to what n critical is in in +just a moment uh but any other questions + + align:start position:0% +just a moment uh but any other questions + + + align:start position:0% +just a moment uh but any other questions +on this before we keep going + + align:start position:0% + + + + align:start position:0% + +okay so we just said that n is equal to + + align:start position:0% +okay so we just said that n is equal to + + + align:start position:0% +okay so we just said that n is equal to +theare root of 1 minus NE Over N + + align:start position:0% +theare root of 1 minus NE Over N + + + align:start position:0% +theare root of 1 minus NE Over N +critical if we work in a regime where NE + + align:start position:0% +critical if we work in a regime where NE + + + align:start position:0% +critical if we work in a regime where NE +is much much less than n critical so we + + align:start position:0% +is much much less than n critical so we + + + align:start position:0% +is much much less than n critical so we +work far from the critical density we + + align:start position:0% +work far from the critical density we + + + align:start position:0% +work far from the critical density we +can do a tailor expansion and which is + + align:start position:0% +can do a tailor expansion and which is + + + align:start position:0% +can do a tailor expansion and which is +what we often end up doing and we write + + align:start position:0% +what we often end up doing and we write + + + align:start position:0% +what we often end up doing and we write +one minus NE over two and critical like + + align:start position:0% +one minus NE over two and critical like + + + align:start position:0% +one minus NE over two and critical like +this so my questions for you now and we + + align:start position:0% +this so my questions for you now and we + + + align:start position:0% +this so my questions for you now and we +will try and work out what and critical + + align:start position:0% +will try and work out what and critical + + + align:start position:0% +will try and work out what and critical +is doing together for + + align:start position:0% +is doing together for + + + align:start position:0% +is doing together for +n for a density which is greater than + + align:start position:0% +n for a density which is greater than + + + align:start position:0% +n for a density which is greater than +the critical density what + + align:start position:0% + + + + align:start position:0% + +happens to + + align:start position:0% + + + + align:start position:0% + +M the refractor + + align:start position:0% + + + + align:start position:0% + +index the wave becomes + + align:start position:0% +index the wave becomes + + + align:start position:0% +index the wave becomes +right yeah well so that's the result + + align:start position:0% +right yeah well so that's the result + + + align:start position:0% +right yeah well so that's the result +yeah so what happens to n + + align:start position:0% +yeah so what happens to n + + + align:start position:0% +yeah so what happens to n +itself Big N it's + + align:start position:0% +itself Big N it's + + + align:start position:0% +itself Big N it's +imaginary right exactly yeah yeah you + + align:start position:0% +imaginary right exactly yeah yeah you + + + align:start position:0% +imaginary right exactly yeah yeah you +you you you've got the right answer I + + align:start position:0% +you you you've got the right answer I + + + align:start position:0% +you you you've got the right answer I +just wanted to take in a few more steps + + align:start position:0% +just wanted to take in a few more steps + + + align:start position:0% +just wanted to take in a few more steps +so n is + + align:start position:0% +so n is + + + align:start position:0% +so n is +imaginary because it's going to be the + + align:start position:0% +imaginary because it's going to be the + + + align:start position:0% +imaginary because it's going to be the +square root of a negative number which + + align:start position:0% +square root of a negative number which + + + align:start position:0% +square root of a negative number which +we can see + + align:start position:0% +we can see + + + align:start position:0% +we can see +here and so that means our wave becomes + + align:start position:0% +here and so that means our wave becomes + + + align:start position:0% +here and so that means our wave becomes +evanescent so it's going to have + + align:start position:0% +evanescent so it's going to have + + + align:start position:0% +evanescent so it's going to have +properties which decay in time so it's + + align:start position:0% +properties which decay in time so it's + + + align:start position:0% +properties which decay in time so it's +going to look like e minus alpha x e + + align:start position:0% +going to look like e minus alpha x e + + + align:start position:0% +going to look like e minus alpha x e +minus gamma T like this so it dies off + + align:start position:0% +minus gamma T like this so it dies off + + + align:start position:0% +minus gamma T like this so it dies off +okay so that means that we can't + + align:start position:0% +okay so that means that we can't + + + align:start position:0% +okay so that means that we can't +propagate a wave at densities greater + + align:start position:0% +propagate a wave at densities greater + + + align:start position:0% +propagate a wave at densities greater +than the critical density what happens + + align:start position:0% +than the critical density what happens + + + align:start position:0% +than the critical density what happens +to all the energy + + align:start position:0% + + + + align:start position:0% + +then because this wave is carrying + + align:start position:0% + + + + align:start position:0% + +energy abor + + align:start position:0% + + + + align:start position:0% + +no absorption mechanism in our equations + + align:start position:0% + + + + align:start position:0% + +actually yeah so that I mean from the + + align:start position:0% +actually yeah so that I mean from the + + + align:start position:0% +actually yeah so that I mean from the +math we have it the only option is + + align:start position:0% +math we have it the only option is + + + align:start position:0% +math we have it the only option is +reflection right + + align:start position:0% +reflection right + + + align:start position:0% +reflection right +yeah so reflection is indeed the answer + + align:start position:0% +yeah so reflection is indeed the answer + + + align:start position:0% +yeah so reflection is indeed the answer +so we will get reflection of this wave + + align:start position:0% +so we will get reflection of this wave + + + align:start position:0% +so we will get reflection of this wave +that will bounce off the critical + + align:start position:0% +that will bounce off the critical + + + align:start position:0% +that will bounce off the critical +surface and go somewhere + + align:start position:0% + + + + align:start position:0% + +else um we'd only be able to have + + align:start position:0% +else um we'd only be able to have + + + align:start position:0% +else um we'd only be able to have +absorption if we put for example + + align:start position:0% +absorption if we put for example + + + align:start position:0% +absorption if we put for example +collisions into the equation of motion + + align:start position:0% +collisions into the equation of motion + + + align:start position:0% +collisions into the equation of motion +all the way back there and then we could + + align:start position:0% +all the way back there and then we could + + + align:start position:0% +all the way back there and then we could +have what's called inverse brmr which is + + align:start position:0% +have what's called inverse brmr which is + + + align:start position:0% +have what's called inverse brmr which is +effectively the electrons get oscillated + + align:start position:0% +effectively the electrons get oscillated + + + align:start position:0% +effectively the electrons get oscillated +by the wave and then they collide with + + align:start position:0% +by the wave and then they collide with + + + align:start position:0% +by the wave and then they collide with +some ions and transfer the energy to the + + align:start position:0% +some ions and transfer the energy to the + + + align:start position:0% +some ions and transfer the energy to the +ions and that's a damping mechanism + + align:start position:0% +ions and that's a damping mechanism + + + align:start position:0% +ions and that's a damping mechanism +there could be other damping mechanisms + + align:start position:0% +there could be other damping mechanisms + + + align:start position:0% +there could be other damping mechanisms +like landal but in the equations we've + + align:start position:0% +like landal but in the equations we've + + + align:start position:0% +like landal but in the equations we've +got so far we we don't actually have + + align:start position:0% +got so far we we don't actually have + + + align:start position:0% +got so far we we don't actually have +those so reflection is the only thing + + align:start position:0% +those so reflection is the only thing + + + align:start position:0% +those so reflection is the only thing +that can happen now we also had this + + align:start position:0% +that can happen now we also had this + + + align:start position:0% +that can happen now we also had this +equation for the phase velocity which + + align:start position:0% +equation for the phase velocity which + + + align:start position:0% +equation for the phase velocity which +was that VP is equal to + + align:start position:0% +was that VP is equal to + + + align:start position:0% +was that VP is equal to +C over 1us Omega p^ 2 upon Omega s to + + align:start position:0% +C over 1us Omega p^ 2 upon Omega s to + + + align:start position:0% +C over 1us Omega p^ 2 upon Omega s to +the half does anyone want to comment on + + align:start position:0% +the half does anyone want to comment on + + + align:start position:0% +the half does anyone want to comment on +what happens to the phase velocity as we + + align:start position:0% +what happens to the phase velocity as we + + + align:start position:0% +what happens to the phase velocity as we +go above the critical + + align:start position:0% + + + + align:start position:0% + +density there's a go to + + align:start position:0% +density there's a go to + + + align:start position:0% +density there's a go to +Infinity oh I mean we'll do that + + align:start position:0% +Infinity oh I mean we'll do that + + + align:start position:0% +Infinity oh I mean we'll do that +eventually yes yeah yes I guess right + + align:start position:0% +eventually yes yeah yes I guess right + + + align:start position:0% +eventually yes yeah yes I guess right +there at that point diverges extremely + + align:start position:0% +there at that point diverges extremely + + + align:start position:0% +there at that point diverges extremely +large yeah + + align:start position:0% +large yeah + + + align:start position:0% +large yeah +yes yeah so this is this is going to + + align:start position:0% +yes yeah so this is this is going to + + + align:start position:0% +yes yeah so this is this is going to +start doing very + + align:start position:0% +start doing very + + + align:start position:0% +start doing very +silly things here and those things don't + + align:start position:0% +silly things here and those things don't + + + align:start position:0% +silly things here and those things don't +seem very physical of course because we + + align:start position:0% +seem very physical of course because we + + + align:start position:0% +seem very physical of course because we +don't want things traveling FAS than the + + align:start position:0% +don't want things traveling FAS than the + + + align:start position:0% +don't want things traveling FAS than the +speed of light um fortunately this isn't + + align:start position:0% +speed of light um fortunately this isn't + + + align:start position:0% +speed of light um fortunately this isn't +a big problem um because the phase + + align:start position:0% +a big problem um because the phase + + + align:start position:0% +a big problem um because the phase +velocity doesn't carry any information + + align:start position:0% +velocity doesn't carry any information + + + align:start position:0% +velocity doesn't carry any information +the limitations on things going faster + + align:start position:0% +the limitations on things going faster + + + align:start position:0% +the limitations on things going faster +and the speed of light have to do with + + align:start position:0% +and the speed of light have to do with + + + align:start position:0% +and the speed of light have to do with +information and the information is + + align:start position:0% +information and the information is + + + align:start position:0% +information and the information is +encoded in a quantity called the group + + align:start position:0% +encoded in a quantity called the group + + + align:start position:0% +encoded in a quantity called the group +velocity and the group velocity just + + align:start position:0% +velocity and the group velocity just + + + align:start position:0% +velocity and the group velocity just +looks like + + align:start position:0% +looks like + + + align:start position:0% +looks like +this c times the square root of 1 minus + + align:start position:0% +this c times the square root of 1 minus + + + align:start position:0% +this c times the square root of 1 minus +Omega p^ 2 upon Omega squ and so as we + + align:start position:0% +Omega p^ 2 upon Omega squ and so as we + + + align:start position:0% +Omega p^ 2 upon Omega squ and so as we +get close to the critical density here + + align:start position:0% +get close to the critical density here + + + align:start position:0% +get close to the critical density here +all that happens is the group velocity + + align:start position:0% +all that happens is the group velocity + + + align:start position:0% +all that happens is the group velocity +goes to zero and effectively we transmit + + align:start position:0% +goes to zero and effectively we transmit + + + align:start position:0% +goes to zero and effectively we transmit +no information through that evanescent + + align:start position:0% +no information through that evanescent + + + align:start position:0% +no information through that evanescent +region so we don't have to worry about + + align:start position:0% +region so we don't have to worry about + + + align:start position:0% +region so we don't have to worry about +the fact phase velocity is super luminal + + align:start position:0% +the fact phase velocity is super luminal + + + align:start position:0% +the fact phase velocity is super luminal +because our group velocity is still + + align:start position:0% +because our group velocity is still + + + align:start position:0% +because our group velocity is still +subluminal as you know we'd like + + align:start position:0% +subluminal as you know we'd like + + + align:start position:0% +subluminal as you know we'd like +sh so if the waves being reflected here + + align:start position:0% +sh so if the waves being reflected here + + + align:start position:0% +sh so if the waves being reflected here +and the group velocity is going to zero + + align:start position:0% +and the group velocity is going to zero + + + align:start position:0% +and the group velocity is going to zero +to me that seems like the wave + + align:start position:0% +to me that seems like the wave + + + align:start position:0% +to me that seems like the wave +information is sort of stagnating at the + + align:start position:0% +information is sort of stagnating at the + + + align:start position:0% +information is sort of stagnating at the +Reflection Point how do we see from + + align:start position:0% +Reflection Point how do we see from + + + align:start position:0% +Reflection Point how do we see from +these equations that the wave + + align:start position:0% +these equations that the wave + + + align:start position:0% +these equations that the wave +information is actually being reflected + + align:start position:0% +information is actually being reflected + + + align:start position:0% +information is actually being reflected +back + + align:start position:0% +back + + + align:start position:0% +back +out it's very good + + align:start position:0% +out it's very good + + + align:start position:0% +out it's very good +question I think you um excuse me I + + align:start position:0% +question I think you um excuse me I + + + align:start position:0% +question I think you um excuse me I +think you need to like impose boundary + + align:start position:0% +think you need to like impose boundary + + + align:start position:0% +think you need to like impose boundary +conditions to to do that so because + + align:start position:0% +conditions to to do that so because + + + align:start position:0% +conditions to to do that so because +there' be some sort of discontinuity + + align:start position:0% +there' be some sort of discontinuity + + + align:start position:0% +there' be some sort of discontinuity +right yeah I suspect the model I'm + + align:start position:0% +right yeah I suspect the model I'm + + + align:start position:0% +right yeah I suspect the model I'm +presenting is a little bit too + + align:start position:0% +presenting is a little bit too + + + align:start position:0% +presenting is a little bit too +simplistic to handle this stuff um so we + + align:start position:0% +simplistic to handle this stuff um so we + + + align:start position:0% +simplistic to handle this stuff um so we +would need to bake in some more + + align:start position:0% +would need to bake in some more + + + align:start position:0% +would need to bake in some more +information + + align:start position:0% +information + + + align:start position:0% +information +I think so there certainly as you get + + align:start position:0% +I think so there certainly as you get + + + align:start position:0% +I think so there certainly as you get +very very slow group velocities you're + + align:start position:0% +very very slow group velocities you're + + + align:start position:0% +very very slow group velocities you're +going to + + align:start position:0% +going to + + + align:start position:0% +going to +start we've been making some assumptions + + align:start position:0% +start we've been making some assumptions + + + align:start position:0% +start we've been making some assumptions +about the homogeneity here and so we're + + align:start position:0% +about the homogeneity here and so we're + + + align:start position:0% +about the homogeneity here and so we're +effectively there's going to be some + + align:start position:0% +effectively there's going to be some + + + align:start position:0% +effectively there's going to be some +length scale in here which is going to + + align:start position:0% +length scale in here which is going to + + + align:start position:0% +length scale in here which is going to +be like K the size of the wave Vector of + + align:start position:0% +be like K the size of the wave Vector of + + + align:start position:0% +be like K the size of the wave Vector of +the light at a given point and we're + + align:start position:0% +the light at a given point and we're + + + align:start position:0% +the light at a given point and we're +going to be comparing that to the length + + align:start position:0% +going to be comparing that to the length + + + align:start position:0% +going to be comparing that to the length +scale associated with how quickly the + + align:start position:0% +scale associated with how quickly the + + + align:start position:0% +scale associated with how quickly the +electron density changes this gradient + + align:start position:0% +electron density changes this gradient + + + align:start position:0% +electron density changes this gradient +length scale here and as the + + align:start position:0% +length scale here and as the + + + align:start position:0% +length scale here and as the +group velocity gets very very low that K + + align:start position:0% +group velocity gets very very low that K + + + align:start position:0% +group velocity gets very very low that K +is going to get uh very very long and uh + + align:start position:0% +is going to get uh very very long and uh + + + align:start position:0% +is going to get uh very very long and uh +we're going to start violating our our + + align:start position:0% +we're going to start violating our our + + + align:start position:0% +we're going to start violating our our +assumption that K is let's see let me + + align:start position:0% +assumption that K is let's see let me + + + align:start position:0% +assumption that K is let's see let me +maybe I can write this as Lambda that + + align:start position:0% +maybe I can write this as Lambda that + + + align:start position:0% +maybe I can write this as Lambda that +Lambda is going to be much much less + + align:start position:0% +Lambda is going to be much much less + + + align:start position:0% +Lambda is going to be much much less +than this uh change in the gradient so + + align:start position:0% +than this uh change in the gradient so + + + align:start position:0% +than this uh change in the gradient so +for any realistic system our density has + + align:start position:0% +for any realistic system our density has + + + align:start position:0% +for any realistic system our density has +to ramp up right it can't just + + align:start position:0% +to ramp up right it can't just + + + align:start position:0% +to ramp up right it can't just +immediately get up to the critical + + align:start position:0% +immediately get up to the critical + + + align:start position:0% +immediately get up to the critical +density this could be the critical + + align:start position:0% +density this could be the critical + + + align:start position:0% +density this could be the critical +density here and we're going to find out + + align:start position:0% +density here and we're going to find out + + + align:start position:0% +density here and we're going to find out +that there's some region where some of + + align:start position:0% +that there's some region where some of + + + align:start position:0% +that there's some region where some of +the approximations we've implicitly been + + align:start position:0% +the approximations we've implicitly been + + + align:start position:0% +the approximations we've implicitly been +making break down and then you not need + + align:start position:0% +making break down and then you not need + + + align:start position:0% +making break down and then you not need +to start doing like uh wbk and all that + + align:start position:0% +to start doing like uh wbk and all that + + + align:start position:0% +to start doing like uh wbk and all that +sort of stuff and doing everything + + align:start position:0% +sort of stuff and doing everything + + + align:start position:0% +sort of stuff and doing everything +properly so I think effectively this + + align:start position:0% +properly so I think effectively this + + + align:start position:0% +properly so I think effectively this +simple model breaks down but if you do + + align:start position:0% +simple model breaks down but if you do + + + align:start position:0% +simple model breaks down but if you do +it properly and I think Hutchinson does + + align:start position:0% +it properly and I think Hutchinson does + + + align:start position:0% +it properly and I think Hutchinson does +this in the reflectometry section so we + + align:start position:0% +this in the reflectometry section so we + + + align:start position:0% +this in the reflectometry section so we +may end up doing it um you you can get + + align:start position:0% +may end up doing it um you you can get + + + align:start position:0% +may end up doing it um you you can get +the answer about the reflection there + + align:start position:0% +the answer about the reflection there + + + align:start position:0% +the answer about the reflection there +it's a good question this is very + + align:start position:0% +it's a good question this is very + + + align:start position:0% +it's a good question this is very +handwavy at this point I agree thanks + + align:start position:0% +handwavy at this point I agree thanks + + + align:start position:0% +handwavy at this point I agree thanks +cool any other questions on this because + + align:start position:0% +cool any other questions on this because + + + align:start position:0% +cool any other questions on this because +this this equation here we are now going + + align:start position:0% +this this equation here we are now going + + + align:start position:0% +this this equation here we are now going +to use an awful lot so I'd like you to + + align:start position:0% +to use an awful lot so I'd like you to + + + align:start position:0% +to use an awful lot so I'd like you to +agree that it's valid within the + + align:start position:0% +agree that it's valid within the + + + align:start position:0% +agree that it's valid within the +assumptions that we've made and if you + + align:start position:0% +assumptions that we've made and if you + + + align:start position:0% +assumptions that we've made and if you +don't agree we should have talk about + + align:start position:0% + + + + align:start position:0% + +it okay good so let's keep going so + + align:start position:0% +it okay good so let's keep going so + + + align:start position:0% +it okay good so let's keep going so +there is a series of different + + align:start position:0% +there is a series of different + + + align:start position:0% +there is a series of different +measurements that we can make and these + + align:start position:0% +measurements that we can make and these + + + align:start position:0% +measurements that we can make and these +are the refractive index Diagnostics so + + align:start position:0% +are the refractive index Diagnostics so + + + align:start position:0% +are the refractive index Diagnostics so +I'm going to just call these n + + align:start position:0% +I'm going to just call these n + + + align:start position:0% +I'm going to just call these n +measurements or n + + align:start position:0% +measurements or n + + + align:start position:0% +measurements or n +Diagnostics because they rely on the + + align:start position:0% +Diagnostics because they rely on the + + + align:start position:0% +Diagnostics because they rely on the +change in the refractive index here so + + align:start position:0% +change in the refractive index here so + + + align:start position:0% +change in the refractive index here so +one type is when the refractive index is + + align:start position:0% +one type is when the refractive index is + + + align:start position:0% +one type is when the refractive index is +not equal to one there's a refractive + + align:start position:0% +not equal to one there's a refractive + + + align:start position:0% +not equal to one there's a refractive +index inside our plasma is not equal to + + align:start position:0% +index inside our plasma is not equal to + + + align:start position:0% +index inside our plasma is not equal to +one which is true anytime there's any + + align:start position:0% +one which is true anytime there's any + + + align:start position:0% +one which is true anytime there's any +density inside the + + align:start position:0% +density inside the + + + align:start position:0% +density inside the +plasma this sort of diagnostic causes a + + align:start position:0% +plasma this sort of diagnostic causes a + + + align:start position:0% +plasma this sort of diagnostic causes a +phase shift so the plasma ends up the + + align:start position:0% +phase shift so the plasma ends up the + + + align:start position:0% +phase shift so the plasma ends up the +the the laser beam going through or the + + align:start position:0% +the the laser beam going through or the + + + align:start position:0% +the the laser beam going through or the +electromagnetic radiation going through + + align:start position:0% +electromagnetic radiation going through + + + align:start position:0% +electromagnetic radiation going through +plas ends up with a different phasee + + align:start position:0% +plas ends up with a different phasee + + + align:start position:0% +plas ends up with a different phasee +than it would have done in the absence + + align:start position:0% +than it would have done in the absence + + + align:start position:0% +than it would have done in the absence +of the plasma and we can measure that + + align:start position:0% +of the plasma and we can measure that + + + align:start position:0% +of the plasma and we can measure that +phase shift using a technique called + + align:start position:0% +phase shift using a technique called + + + align:start position:0% +phase shift using a technique called +interferometry and with interferometry + + align:start position:0% +interferometry and with interferometry + + + align:start position:0% +interferometry and with interferometry +we can therefore say something about the + + align:start position:0% +we can therefore say something about the + + + align:start position:0% +we can therefore say something about the +density inside the + + align:start position:0% +density inside the + + + align:start position:0% +density inside the +plasma another technique is when the + + align:start position:0% +plasma another technique is when the + + + align:start position:0% +plasma another technique is when the +gradient of the refractive index is not + + align:start position:0% +gradient of the refractive index is not + + + align:start position:0% +gradient of the refractive index is not +equal to zero so this is when there is + + align:start position:0% +equal to zero so this is when there is + + + align:start position:0% +equal to zero so this is when there is +any change in the refractive index and + + align:start position:0% +any change in the refractive index and + + + align:start position:0% +any change in the refractive index and +in a plasma that corresponds very + + align:start position:0% +in a plasma that corresponds very + + + align:start position:0% +in a plasma that corresponds very +clearly to just changes in the electron + + align:start position:0% +clearly to just changes in the electron + + + align:start position:0% +clearly to just changes in the electron +density so gradients in the electron + + align:start position:0% +density so gradients in the electron + + + align:start position:0% +density so gradients in the electron +density but of course in general this + + align:start position:0% +density but of course in general this + + + align:start position:0% +density but of course in general this +technique could be used for any medium + + align:start position:0% +technique could be used for any medium + + + align:start position:0% +technique could be used for any medium +weather refractive index changes so air + + align:start position:0% +weather refractive index changes so air + + + align:start position:0% +weather refractive index changes so air +if you heat it up the refracted index + + align:start position:0% +if you heat it up the refracted index + + + align:start position:0% +if you heat it up the refracted index +changes and so you could use these + + align:start position:0% +changes and so you could use these + + + align:start position:0% +changes and so you could use these +techniques these are not specific to + + align:start position:0% +techniques these are not specific to + + + align:start position:0% +techniques these are not specific to +plasma physics and these Diagnostics + + align:start position:0% +plasma physics and these Diagnostics + + + align:start position:0% +plasma physics and these Diagnostics +tend to be called refraction Diagnostics + + align:start position:0% +tend to be called refraction Diagnostics + + + align:start position:0% +tend to be called refraction Diagnostics +because the light refracts and it bends + + align:start position:0% +because the light refracts and it bends + + + align:start position:0% +because the light refracts and it bends +and we end up doing techniques such as + + align:start position:0% +and we end up doing techniques such as + + + align:start position:0% +and we end up doing techniques such as +schen and + + align:start position:0% + + + + align:start position:0% + +ography and then the final type that I'm + + align:start position:0% +ography and then the final type that I'm + + + align:start position:0% +ography and then the final type that I'm +going to talk about are ones where + + align:start position:0% +going to talk about are ones where + + + align:start position:0% +going to talk about are ones where +actually the + + align:start position:0% +actually the + + + align:start position:0% +actually the +polarization uh the the the medium is B + + align:start position:0% +polarization uh the the the medium is B + + + align:start position:0% +polarization uh the the the medium is B +refringent it treats different + + align:start position:0% +refringent it treats different + + + align:start position:0% +refringent it treats different +polarizations differently and so we can + + align:start position:0% +polarizations differently and so we can + + + align:start position:0% +polarizations differently and so we can +have polarizations of Light which are + + align:start position:0% +have polarizations of Light which are + + + align:start position:0% +have polarizations of Light which are +circular we can have the left-handed and + + align:start position:0% +circular we can have the left-handed and + + + align:start position:0% +circular we can have the left-handed and +the right-handed polarizations which we + + align:start position:0% +the right-handed polarizations which we + + + align:start position:0% +the right-handed polarizations which we +sometimes refer to as plus and minus and + + align:start position:0% +sometimes refer to as plus and minus and + + + align:start position:0% +sometimes refer to as plus and minus and +here we would say that the refractive + + align:start position:0% +here we would say that the refractive + + + align:start position:0% +here we would say that the refractive +index for the plus wave is not equal to + + align:start position:0% +index for the plus wave is not equal to + + + align:start position:0% +index for the plus wave is not equal to +the refractive index of the minus wave + + align:start position:0% +the refractive index of the minus wave + + + align:start position:0% +the refractive index of the minus wave +here and so there here we measure the + + align:start position:0% + + + + align:start position:0% + +polarization and this is using a + + align:start position:0% +polarization and this is using a + + + align:start position:0% +polarization and this is using a +technique called + + align:start position:0% +technique called + + + align:start position:0% +technique called +Faraday + + align:start position:0% + + + + align:start position:0% + +or Faraday + + align:start position:0% + + + + align:start position:0% + +rotation which we briefly discussed in + + align:start position:0% +rotation which we briefly discussed in + + + align:start position:0% +rotation which we briefly discussed in +the context of magnetic field + + align:start position:0% +the context of magnetic field + + + align:start position:0% +the context of magnetic field +measurements using ver glass + + align:start position:0% +measurements using ver glass + + + align:start position:0% +measurements using ver glass +um and in fact it turns out that you + + align:start position:0% +um and in fact it turns out that you + + + align:start position:0% +um and in fact it turns out that you +need to have magnetic fields that are + + align:start position:0% +need to have magnetic fields that are + + + align:start position:0% +need to have magnetic fields that are +nonzero and we also need to relax our + + align:start position:0% +nonzero and we also need to relax our + + + align:start position:0% +nonzero and we also need to relax our +assumption that the plasma is + + align:start position:0% +assumption that the plasma is + + + align:start position:0% +assumption that the plasma is +unmagnetized in the sense that the light + + align:start position:0% +unmagnetized in the sense that the light + + + align:start position:0% +unmagnetized in the sense that the light +frequency is much larger than the + + align:start position:0% +frequency is much larger than the + + + align:start position:0% +frequency is much larger than the +electron cyron frequency so those are + + align:start position:0% +electron cyron frequency so those are + + + align:start position:0% +electron cyron frequency so those are +three different types of refractive + + align:start position:0% +three different types of refractive + + + align:start position:0% +three different types of refractive +index Diagnostic and we're going to + + align:start position:0% +index Diagnostic and we're going to + + + align:start position:0% +index Diagnostic and we're going to +start with what I think is conceptually + + align:start position:0% +start with what I think is conceptually + + + align:start position:0% +start with what I think is conceptually +the simplest but still often causes us + + align:start position:0% +the simplest but still often causes us + + + align:start position:0% +the simplest but still often causes us +lots of problems + + align:start position:0% +lots of problems + + + align:start position:0% +lots of problems +which are the refraction Diagnostics + + align:start position:0% + + + + align:start position:0% + +here I see some people rising so I'm + + align:start position:0% +here I see some people rising so I'm + + + align:start position:0% +here I see some people rising so I'm +just going to pause on this slide for a + + align:start position:0% + + + + align:start position:0% + +moment oky do + + align:start position:0% +moment oky do + + + align:start position:0% +moment oky do +now I just want to have a little aside + + align:start position:0% +now I just want to have a little aside + + + align:start position:0% +now I just want to have a little aside +and this is on conceptual models + + align:start position:0% + + + + align:start position:0% + +for + + align:start position:0% +for + + + align:start position:0% +for +electromagnetic + + align:start position:0% + + + + align:start position:0% + +propagation because I'm going to be + + align:start position:0% +propagation because I'm going to be + + + align:start position:0% +propagation because I'm going to be +switching quite a lot between different + + align:start position:0% +switching quite a lot between different + + + align:start position:0% +switching quite a lot between different +ways of thinking about electromagnetic + + align:start position:0% +ways of thinking about electromagnetic + + + align:start position:0% +ways of thinking about electromagnetic +radiation and how it moves through a + + align:start position:0% +radiation and how it moves through a + + + align:start position:0% +radiation and how it moves through a +plasma because sometimes some models are + + align:start position:0% +plasma because sometimes some models are + + + align:start position:0% +plasma because sometimes some models are +easier to work with than others + + align:start position:0% +easier to work with than others + + + align:start position:0% +easier to work with than others +sometimes models are simplifications and + + align:start position:0% +sometimes models are simplifications and + + + align:start position:0% +sometimes models are simplifications and +they throw away physics um but they make + + align:start position:0% +they throw away physics um but they make + + + align:start position:0% +they throw away physics um but they make +the intuition much simpler so I just + + align:start position:0% +the intuition much simpler so I just + + + align:start position:0% +the intuition much simpler so I just +want to show you two different models + + align:start position:0% +want to show you two different models + + + align:start position:0% +want to show you two different models +that we be going to be using in these + + align:start position:0% +that we be going to be using in these + + + align:start position:0% +that we be going to be using in these +next few lectures so that you have an + + align:start position:0% +next few lectures so that you have an + + + align:start position:0% +next few lectures so that you have an +idea of what's going on one model will + + align:start position:0% +idea of what's going on one model will + + + align:start position:0% +idea of what's going on one model will +be a model of wave + + align:start position:0% +be a model of wave + + + align:start position:0% +be a model of wave +fronts so this is based on the idea that + + align:start position:0% +fronts so this is based on the idea that + + + align:start position:0% +fronts so this is based on the idea that +as we said our electric and magnetic + + align:start position:0% +as we said our electric and magnetic + + + align:start position:0% +as we said our electric and magnetic +fields can be written as just a single + + align:start position:0% +fields can be written as just a single + + + align:start position:0% +fields can be written as just a single +Foria component so there's some strength + + align:start position:0% +Foria component so there's some strength + + + align:start position:0% +Foria component so there's some strength +and polarization of the electric uh + + align:start position:0% +and polarization of the electric uh + + + align:start position:0% +and polarization of the electric uh +field here and this is multiplied by the + + align:start position:0% +field here and this is multiplied by the + + + align:start position:0% +field here and this is multiplied by the +exponential of what we call the phase + + align:start position:0% +exponential of what we call the phase + + + align:start position:0% +exponential of what we call the phase +Factor so i k Dot x minus Omega T like + + align:start position:0% +Factor so i k Dot x minus Omega T like + + + align:start position:0% +Factor so i k Dot x minus Omega T like +this which we could write as e0 + + align:start position:0% +this which we could write as e0 + + + align:start position:0% +this which we could write as e0 +exponential of I times some scalar + + align:start position:0% +exponential of I times some scalar + + + align:start position:0% +exponential of I times some scalar +quantity which is the phase here and so + + align:start position:0% +quantity which is the phase here and so + + + align:start position:0% +quantity which is the phase here and so +if we think of our electromagnetic wave + + align:start position:0% +if we think of our electromagnetic wave + + + align:start position:0% +if we think of our electromagnetic wave +as having a phase and the + + align:start position:0% +as having a phase and the + + + align:start position:0% +as having a phase and the +electromagnetic wave still exists in all + + align:start position:0% +electromagnetic wave still exists in all + + + align:start position:0% +electromagnetic wave still exists in all +places at all points in time blah blah + + align:start position:0% +places at all points in time blah blah + + + align:start position:0% +places at all points in time blah blah +blah blah blah um but that's a very + + align:start position:0% +blah blah blah um but that's a very + + + align:start position:0% +blah blah blah um but that's a very +difficult thing for me to sketch on my + + align:start position:0% +difficult thing for me to sketch on my + + + align:start position:0% +difficult thing for me to sketch on my +iPad here or on the board in front of + + align:start position:0% +iPad here or on the board in front of + + + align:start position:0% +iPad here or on the board in front of +you so what I'll end up sketching are + + align:start position:0% +you so what I'll end up sketching are + + + align:start position:0% +you so what I'll end up sketching are +what we call isophase + + align:start position:0% +what we call isophase + + + align:start position:0% +what we call isophase +Contours so these are + + align:start position:0% +Contours so these are + + + align:start position:0% +Contours so these are +Contours along which the phase + + align:start position:0% +Contours along which the phase + + + align:start position:0% +Contours along which the phase +is constant and so for example it could + + align:start position:0% +is constant and so for example it could + + + align:start position:0% +is constant and so for example it could +be at some integer multiple of Pi right + + align:start position:0% +be at some integer multiple of Pi right + + + align:start position:0% +be at some integer multiple of Pi right +for yes M belonging to Zen so this might + + align:start position:0% +for yes M belonging to Zen so this might + + + align:start position:0% +for yes M belonging to Zen so this might +look like some + + align:start position:0% +look like some + + + align:start position:0% +look like some +waves like this this would be + + align:start position:0% +waves like this this would be + + + align:start position:0% +waves like this this would be +electromagnetic wave which is diverging + + align:start position:0% +electromagnetic wave which is diverging + + + align:start position:0% +electromagnetic wave which is diverging +here actually it could be an + + align:start position:0% +here actually it could be an + + + align:start position:0% +here actually it could be an +electromagnetic wave which is converging + + align:start position:0% +electromagnetic wave which is converging + + + align:start position:0% +electromagnetic wave which is converging +to the left but you know at the moment + + align:start position:0% +to the left but you know at the moment + + + align:start position:0% +to the left but you know at the moment +it looks like it's diverging to the + + align:start position:0% +it looks like it's diverging to the + + + align:start position:0% +it looks like it's diverging to the +right okay so that's one way I could + + align:start position:0% +right okay so that's one way I could + + + align:start position:0% +right okay so that's one way I could +draw a wave + + align:start position:0% +draw a wave + + + align:start position:0% +draw a wave +here another way I could do it is with + + align:start position:0% +here another way I could do it is with + + + align:start position:0% +here another way I could do it is with +array + + align:start position:0% + + + + align:start position:0% + +model and this gets into a topic which + + align:start position:0% +model and this gets into a topic which + + + align:start position:0% +model and this gets into a topic which +is called geometric + + align:start position:0% + + + + align:start position:0% + +optics and it turns out what you can do + + align:start position:0% +optics and it turns out what you can do + + + align:start position:0% +optics and it turns out what you can do +if you have some isophase Contours like + + align:start position:0% +if you have some isophase Contours like + + + align:start position:0% +if you have some isophase Contours like +the ones I just drew say these Contours + + align:start position:0% +the ones I just drew say these Contours + + + align:start position:0% +the ones I just drew say these Contours +here they're doing something slightly + + align:start position:0% +here they're doing something slightly + + + align:start position:0% +here they're doing something slightly +strange because but perhaps there's a + + align:start position:0% +strange because but perhaps there's a + + + align:start position:0% +strange because but perhaps there's a +plasma there which is like you know + + align:start position:0% +plasma there which is like you know + + + align:start position:0% +plasma there which is like you know +moving the phase Contour around right we + + align:start position:0% +moving the phase Contour around right we + + + align:start position:0% +moving the phase Contour around right we +said if there's a change in refractive + + align:start position:0% +said if there's a change in refractive + + + align:start position:0% +said if there's a change in refractive +index that affect the phase the Rays + + align:start position:0% +index that affect the phase the Rays + + + align:start position:0% +index that affect the phase the Rays +that we draw here I can just take these + + align:start position:0% +that we draw here I can just take these + + + align:start position:0% +that we draw here I can just take these +phase contols and I can draw Rays such + + align:start position:0% +phase contols and I can draw Rays such + + + align:start position:0% +phase contols and I can draw Rays such +that they are everywhere normal to the + + align:start position:0% +that they are everywhere normal to the + + + align:start position:0% +that they are everywhere normal to the +isophase Contours so this Ray would look + + align:start position:0% +isophase Contours so this Ray would look + + + align:start position:0% +isophase Contours so this Ray would look +like this this one would look like this + + align:start position:0% +like this this one would look like this + + + align:start position:0% +like this this one would look like this +and this one would look like that so + + align:start position:0% +and this one would look like that so + + + align:start position:0% +and this one would look like that so +they are perpendicular to the wave + + align:start position:0% + + + + align:start position:0% + +fronts conveniently they're also + + align:start position:0% +fronts conveniently they're also + + + align:start position:0% +fronts conveniently they're also +parallel to the pointing + + align:start position:0% +parallel to the pointing + + + align:start position:0% +parallel to the pointing +Vector least I'm pretty convinced they + + align:start position:0% +Vector least I'm pretty convinced they + + + align:start position:0% +Vector least I'm pretty convinced they +are If someone knows more about + + align:start position:0% +are If someone knows more about + + + align:start position:0% +are If someone knows more about +geometric optics and thinks I'm wrong + + align:start position:0% +geometric optics and thinks I'm wrong + + + align:start position:0% +geometric optics and thinks I'm wrong +please shout out because this was a very + + align:start position:0% +please shout out because this was a very + + + align:start position:0% +please shout out because this was a very +hard fact to check um in like 10 minutes + + align:start position:0% +hard fact to check um in like 10 minutes + + + align:start position:0% +hard fact to check um in like 10 minutes +before the lecture but I'm pretty + + align:start position:0% +before the lecture but I'm pretty + + + align:start position:0% +before the lecture but I'm pretty +certain they represent the direction of + + align:start position:0% +certain they represent the direction of + + + align:start position:0% +certain they represent the direction of +the energy flux in electromagnetic wav + + align:start position:0% +the energy flux in electromagnetic wav + + + align:start position:0% +the energy flux in electromagnetic wav +so they're quite conceptually useful as + + align:start position:0% +so they're quite conceptually useful as + + + align:start position:0% +so they're quite conceptually useful as +well they tell us where the power is + + align:start position:0% +well they tell us where the power is + + + align:start position:0% +well they tell us where the power is +Flowing now when we think about these + + align:start position:0% +Flowing now when we think about these + + + align:start position:0% +Flowing now when we think about these +Rays here we can start thinking them a + + align:start position:0% +Rays here we can start thinking them a + + + align:start position:0% +Rays here we can start thinking them a +little bit like it's a + + align:start position:0% +little bit like it's a + + + align:start position:0% +little bit like it's a +particle trajectory and I put particle + + align:start position:0% +particle trajectory and I put particle + + + align:start position:0% +particle trajectory and I put particle +here in speech marks so I don't think + + align:start position:0% +here in speech marks so I don't think + + + align:start position:0% +here in speech marks so I don't think +you really need to think about these as + + align:start position:0% +you really need to think about these as + + + align:start position:0% +you really need to think about these as +photons but you can think about them as + + align:start position:0% +photons but you can think about them as + + + align:start position:0% +photons but you can think about them as +little Point particles that move around + + align:start position:0% +little Point particles that move around + + + align:start position:0% +little Point particles that move around +inside a plasma and we'll find out some + + align:start position:0% +inside a plasma and we'll find out some + + + align:start position:0% +inside a plasma and we'll find out some +rules for how they move inside a plasma + + align:start position:0% +rules for how they move inside a plasma + + + align:start position:0% +rules for how they move inside a plasma +in a moment and if you sort of track + + align:start position:0% +in a moment and if you sort of track + + + align:start position:0% +in a moment and if you sort of track +their trajectory that's where the Rays + + align:start position:0% +their trajectory that's where the Rays + + + align:start position:0% +their trajectory that's where the Rays +gone and then you also know some places + + align:start position:0% +gone and then you also know some places + + + align:start position:0% +gone and then you also know some places +where you'll have lines which are normal + + align:start position:0% +where you'll have lines which are normal + + + align:start position:0% +where you'll have lines which are normal +to the wavefront so maybe you can + + align:start position:0% +to the wavefront so maybe you can + + + align:start position:0% +to the wavefront so maybe you can +reconstruct the wavefronts later on um + + align:start position:0% +reconstruct the wavefronts later on um + + + align:start position:0% +reconstruct the wavefronts later on um +but it's important that when we're doing + + align:start position:0% +but it's important that when we're doing + + + align:start position:0% +but it's important that when we're doing +this we ignore the wave + + align:start position:0% +this we ignore the wave + + + align:start position:0% +this we ignore the wave +effects so we no longer track the phase + + align:start position:0% +effects so we no longer track the phase + + + align:start position:0% +effects so we no longer track the phase +of each particle right it's now just a + + align:start position:0% +of each particle right it's now just a + + + align:start position:0% +of each particle right it's now just a +little billiard ball and Billiard balls + + align:start position:0% +little billiard ball and Billiard balls + + + align:start position:0% +little billiard ball and Billiard balls +don't have phase and so we're we're + + align:start position:0% +don't have phase and so we're we're + + + align:start position:0% +don't have phase and so we're we're +gonna get rid of effects like + + align:start position:0% +gonna get rid of effects like + + + align:start position:0% +gonna get rid of effects like +interference and uh defraction + + align:start position:0% +interference and uh defraction + + + align:start position:0% +interference and uh defraction +and we're going to keep effects only + + align:start position:0% +and we're going to keep effects only + + + align:start position:0% +and we're going to keep effects only +like refraction here so no interference + + align:start position:0% +like refraction here so no interference + + + align:start position:0% +like refraction here so no interference +no defraction just refraction so this is + + align:start position:0% +no defraction just refraction so this is + + + align:start position:0% +no defraction just refraction so this is +our Ray model so does anyone have any + + align:start position:0% +our Ray model so does anyone have any + + + align:start position:0% +our Ray model so does anyone have any +questions on these models before we + + align:start position:0% +questions on these models before we + + + align:start position:0% +questions on these models before we +start trying to use + + align:start position:0% + + + + align:start position:0% + +them um I was just wondering so if the + + align:start position:0% +them um I was just wondering so if the + + + align:start position:0% +them um I was just wondering so if the +pointing Vector right is e cross B does + + align:start position:0% +pointing Vector right is e cross B does + + + align:start position:0% +pointing Vector right is e cross B does +that mean that if we have any parallel + + align:start position:0% +that mean that if we have any parallel + + + align:start position:0% +that mean that if we have any parallel +electric field to hey like I was + + align:start position:0% +electric field to hey like I was + + + align:start position:0% +electric field to hey like I was +wondering um the your point about the + + align:start position:0% +wondering um the your point about the + + + align:start position:0% +wondering um the your point about the +pointing Vector would that break if + + align:start position:0% +pointing Vector would that break if + + + align:start position:0% +pointing Vector would that break if +there was like a parallel e to the main + + align:start position:0% +there was like a parallel e to the main + + + align:start position:0% +there was like a parallel e to the main +back background magnetic field or is + + align:start position:0% +back background magnetic field or is + + + align:start position:0% +back background magnetic field or is +that just the oscillating D + + align:start position:0% + + + + align:start position:0% + +there that question make sense it does + + align:start position:0% +there that question make sense it does + + + align:start position:0% +there that question make sense it does +actually and I know the answer to it + + align:start position:0% +actually and I know the answer to it + + + align:start position:0% +actually and I know the answer to it +that's good right so if you had some + + align:start position:0% +that's good right so if you had some + + + align:start position:0% +that's good right so if you had some +background magnetic field like in the + + align:start position:0% +background magnetic field like in the + + + align:start position:0% +background magnetic field like in the +toac and then your e was parallel to it + + align:start position:0% +toac and then your e was parallel to it + + + align:start position:0% +toac and then your e was parallel to it +um well let's put it this way the the + + align:start position:0% +um well let's put it this way the the + + + align:start position:0% +um well let's put it this way the the +pointing flux uh oscillates right and so + + align:start position:0% +pointing flux uh oscillates right and so + + + align:start position:0% +pointing flux uh oscillates right and so +you when you're averaging it time + + align:start position:0% +you when you're averaging it time + + + align:start position:0% +you when you're averaging it time +averaging it that's what gives you the + + align:start position:0% +averaging it that's what gives you the + + + align:start position:0% +averaging it that's what gives you the +actual power that's moving if you've got + + align:start position:0% +actual power that's moving if you've got + + + align:start position:0% +actual power that's moving if you've got +a static magnetic field your average + + align:start position:0% +a static magnetic field your average + + + align:start position:0% +a static magnetic field your average +power will go to zero okay y thank you + + align:start position:0% +power will go to zero okay y thank you + + + align:start position:0% +power will go to zero okay y thank you +so you'll only get power flow from + + align:start position:0% +so you'll only get power flow from + + + align:start position:0% +so you'll only get power flow from +oscillating components here because + + align:start position:0% +oscillating components here because + + + align:start position:0% +oscillating components here because +that's what's transporting the + + align:start position:0% +that's what's transporting the + + + align:start position:0% +that's what's transporting the +electromagnetic energy but it's a really + + align:start position:0% +electromagnetic energy but it's a really + + + align:start position:0% +electromagnetic energy but it's a really +good + + align:start position:0% +good + + + align:start position:0% +good +question than like I said I'm not + + align:start position:0% +question than like I said I'm not + + + align:start position:0% +question than like I said I'm not +completely 100% sure that Rays follow + + align:start position:0% +completely 100% sure that Rays follow + + + align:start position:0% +completely 100% sure that Rays follow +the trajectory of the pointing Vector + + align:start position:0% +the trajectory of the pointing Vector + + + align:start position:0% +the trajectory of the pointing Vector +but I I'm pretty certain have to + + align:start position:0% +but I I'm pretty certain have to + + + align:start position:0% +but I I'm pretty certain have to +thinking about it for about 10 minutes + + align:start position:0% +thinking about it for about 10 minutes + + + align:start position:0% +thinking about it for about 10 minutes +that they do so if someone finds out + + align:start position:0% +that they do so if someone finds out + + + align:start position:0% +that they do so if someone finds out +that's wrong please let me know and I'll + + align:start position:0% +that's wrong please let me know and I'll + + + align:start position:0% +that's wrong please let me know and I'll +take it + + align:start position:0% +take it + + + align:start position:0% +take it +out okay so everyone is going to be + + align:start position:0% +out okay so everyone is going to be + + + align:start position:0% +out okay so everyone is going to be +pretty happy if I start drawing Ray + + align:start position:0% +pretty happy if I start drawing Ray + + + align:start position:0% +pretty happy if I start drawing Ray +diagrams and they'll understand that + + align:start position:0% +diagrams and they'll understand that + + + align:start position:0% +diagrams and they'll understand that +these Ray diagrams represent the sort of + + align:start position:0% +these Ray diagrams represent the sort of + + + align:start position:0% +these Ray diagrams represent the sort of +trajectory of little beamlets of light + + align:start position:0% +trajectory of little beamlets of light + + + align:start position:0% +trajectory of little beamlets of light +and you could also reconstruct the fa + + align:start position:0% +and you could also reconstruct the fa + + + align:start position:0% +and you could also reconstruct the fa +wave fronts from them and therefore you + + align:start position:0% +wave fronts from them and therefore you + + + align:start position:0% +wave fronts from them and therefore you +could sort of reconstruct visually what + + align:start position:0% +could sort of reconstruct visually what + + + align:start position:0% +could sort of reconstruct visually what +the entire electromagnetic field looks + + align:start position:0% +the entire electromagnetic field looks + + + align:start position:0% +the entire electromagnetic field looks +like and we're implicitly assuming + + align:start position:0% +like and we're implicitly assuming + + + align:start position:0% +like and we're implicitly assuming +everywhere here that our magnetic field + + align:start position:0% +everywhere here that our magnetic field + + + align:start position:0% +everywhere here that our magnetic field +is perpendicular to our electric field + + align:start position:0% +is perpendicular to our electric field + + + align:start position:0% +is perpendicular to our electric field +which is a pretty good approximation for + + align:start position:0% +which is a pretty good approximation for + + + align:start position:0% +which is a pretty good approximation for +the assumptions we've made so + + align:start position:0% + + + + align:start position:0% + +far okay so now let's try putting + + align:start position:0% +far okay so now let's try putting + + + align:start position:0% +far okay so now let's try putting +electromagnetic wave through a + + align:start position:0% + + + + align:start position:0% + +plasma and it's not going to be any old + + align:start position:0% +plasma and it's not going to be any old + + + align:start position:0% +plasma and it's not going to be any old +plasma here I'm going to choose a slab + + align:start position:0% +plasma here I'm going to choose a slab + + + align:start position:0% +plasma here I'm going to choose a slab +of plasma like this and this slab is + + align:start position:0% +of plasma like this and this slab is + + + align:start position:0% +of plasma like this and this slab is +going to be much + + align:start position:0% +going to be much + + + align:start position:0% +going to be much +denser at the top than it is at the + + align:start position:0% +denser at the top than it is at the + + + align:start position:0% +denser at the top than it is at the +bottom which I've tried to really closly + + align:start position:0% +bottom which I've tried to really closly + + + align:start position:0% +bottom which I've tried to really closly +do is some shading here right so it's + + align:start position:0% +do is some shading here right so it's + + + align:start position:0% +do is some shading here right so it's +going to have a gradient of electron + + align:start position:0% +going to have a gradient of electron + + + align:start position:0% +going to have a gradient of electron +density going up like that and of course + + align:start position:0% +density going up like that and of course + + + align:start position:0% +density going up like that and of course +you remember our Formula 1 minus NE over + + align:start position:0% +you remember our Formula 1 minus NE over + + + align:start position:0% +you remember our Formula 1 minus NE over +2N critical for our refractive index + + align:start position:0% +2N critical for our refractive index + + + align:start position:0% +2N critical for our refractive index +we're going to work in this regime where + + align:start position:0% +we're going to work in this regime where + + + align:start position:0% +we're going to work in this regime where +the density is much less than the + + align:start position:0% +the density is much less than the + + + align:start position:0% +the density is much less than the +critical density so we don't have to + + align:start position:0% +critical density so we don't have to + + + align:start position:0% +critical density so we don't have to +worry about what happens if we get close + + align:start position:0% +worry about what happens if we get close + + + align:start position:0% +worry about what happens if we get close +to the critical + + align:start position:0% +to the critical + + + align:start position:0% +to the critical +density and so you can see then that if + + align:start position:0% +density and so you can see then that if + + + align:start position:0% +density and so you can see then that if +the gradient in the electron density is + + align:start position:0% +the gradient in the electron density is + + + align:start position:0% +the gradient in the electron density is +in this direction then the gradient in + + align:start position:0% +in this direction then the gradient in + + + align:start position:0% +in this direction then the gradient in +the ref active index is in the opposite + + align:start position:0% +the ref active index is in the opposite + + + align:start position:0% +the ref active index is in the opposite +direction like + + align:start position:0% +direction like + + + align:start position:0% +direction like +that and we're going to start by putting + + align:start position:0% +that and we're going to start by putting + + + align:start position:0% +that and we're going to start by putting +through some phase + + align:start position:0% +through some phase + + + align:start position:0% +through some phase +fronts and we're going to start with a + + align:start position:0% +fronts and we're going to start with a + + + align:start position:0% +fronts and we're going to start with a +plain wave right so this is a wave in + + align:start position:0% +plain wave right so this is a wave in + + + align:start position:0% +plain wave right so this is a wave in +which the phase fronts are flat and + + align:start position:0% +which the phase fronts are flat and + + + align:start position:0% +which the phase fronts are flat and +parallel and uh uniformly spaced so + + align:start position:0% +parallel and uh uniformly spaced so + + + align:start position:0% +parallel and uh uniformly spaced so +those are my uh wave + + align:start position:0% +those are my uh wave + + + align:start position:0% +those are my uh wave +fronts I'll put a little coordinate + + align:start position:0% +fronts I'll put a little coordinate + + + align:start position:0% +fronts I'll put a little coordinate +system in here I'm going to tend to put + + align:start position:0% +system in here I'm going to tend to put + + + align:start position:0% +system in here I'm going to tend to put +the Zed coordinate in the direction + + align:start position:0% +the Zed coordinate in the direction + + + align:start position:0% +the Zed coordinate in the direction +waves are going and so there'll be two + + align:start position:0% +waves are going and so there'll be two + + + align:start position:0% +waves are going and so there'll be two +transverse coordinates y and x and I'll + + align:start position:0% +transverse coordinates y and x and I'll + + + align:start position:0% +transverse coordinates y and x and I'll +probably just write y on most of these + + align:start position:0% +probably just write y on most of these + + + align:start position:0% +probably just write y on most of these +I'll try and do things in like a + + align:start position:0% +I'll try and do things in like a + + + align:start position:0% +I'll try and do things in like a +one-dimensional sense but everything I + + align:start position:0% +one-dimensional sense but everything I + + + align:start position:0% +one-dimensional sense but everything I +say you can imagine could be applied to + + align:start position:0% +say you can imagine could be applied to + + + align:start position:0% +say you can imagine could be applied to +a threedimensional picture here I'm + + align:start position:0% +a threedimensional picture here I'm + + + align:start position:0% +a threedimensional picture here I'm +going to say that this plasma slab has + + align:start position:0% +going to say that this plasma slab has + + + align:start position:0% +going to say that this plasma slab has +some length L and it's homogeneous + + align:start position:0% +some length L and it's homogeneous + + + align:start position:0% +some length L and it's homogeneous +within that length apart from the + + align:start position:0% +within that length apart from the + + + align:start position:0% +within that length apart from the +gradient in the uh density + + align:start position:0% +gradient in the uh density + + + align:start position:0% +gradient in the uh density +here so does anyone know what happens to + + align:start position:0% +here so does anyone know what happens to + + + align:start position:0% +here so does anyone know what happens to +the phase fronts as they emerge out from + + align:start position:0% +the phase fronts as they emerge out from + + + align:start position:0% +the phase fronts as they emerge out from +this + + align:start position:0% +this + + + align:start position:0% +this +plasma the wave fronts all the Rays I + + align:start position:0% +plasma the wave fronts all the Rays I + + + align:start position:0% +plasma the wave fronts all the Rays I +don't + + align:start position:0% + + + + align:start position:0% + +mind bent and uh wait Upp down + + align:start position:0% + + + + align:start position:0% + +what + + align:start position:0% + + + + align:start position:0% + +sorry yeah + + align:start position:0% + + + + align:start position:0% + +Daniel oh yeah um they're bent down word + + align:start position:0% +Daniel oh yeah um they're bent down word + + + align:start position:0% +Daniel oh yeah um they're bent down word +right because you've got a lower + + align:start position:0% +right because you've got a lower + + + align:start position:0% +right because you've got a lower +refractive index in the upper + + align:start position:0% +refractive index in the upper + + + align:start position:0% +refractive index in the upper +half yeah you're absolutely right so + + align:start position:0% +half yeah you're absolutely right so + + + align:start position:0% +half yeah you're absolutely right so +these rays will emerge or these wave + + align:start position:0% +these rays will emerge or these wave + + + align:start position:0% +these rays will emerge or these wave +fronts will emerge + + align:start position:0% +fronts will emerge + + + align:start position:0% +fronts will emerge +bent like this and so the rays which I + + align:start position:0% +bent like this and so the rays which I + + + align:start position:0% +bent like this and so the rays which I +didn't draw on before but I meant to so + + align:start position:0% +didn't draw on before but I meant to so + + + align:start position:0% +didn't draw on before but I meant to so +here are some rays for you here you see + + align:start position:0% +here are some rays for you here you see + + + align:start position:0% +here are some rays for you here you see +how they're all normal the wave fronts + + align:start position:0% +how they're all normal the wave fronts + + + align:start position:0% +how they're all normal the wave fronts +here are some rays for you + + align:start position:0% + + + + align:start position:0% + +here okay and they're going to be bent + + align:start position:0% +here okay and they're going to be bent + + + align:start position:0% +here okay and they're going to be bent +by some angle which we'll call Theta + + align:start position:0% +by some angle which we'll call Theta + + + align:start position:0% +by some angle which we'll call Theta +here + + align:start position:0% +here + + + align:start position:0% +here +and it turns out if you go and look how + + align:start position:0% +and it turns out if you go and look how + + + align:start position:0% +and it turns out if you go and look how +to do this Theta is going to be equal to + + align:start position:0% +to do this Theta is going to be equal to + + + align:start position:0% +to do this Theta is going to be equal to +D phase + + align:start position:0% +D phase + + + align:start position:0% +D phase +Dy time Lambda over 2 pi and so we can + + align:start position:0% +Dy time Lambda over 2 pi and so we can + + + align:start position:0% +Dy time Lambda over 2 pi and so we can +actually put that all together and we + + align:start position:0% +actually put that all together and we + + + align:start position:0% +actually put that all together and we +can say it's going to be equal to D Dy + + align:start position:0% +can say it's going to be equal to D Dy + + + align:start position:0% +can say it's going to be equal to D Dy +times the integral of capital n d z like + + align:start position:0% +times the integral of capital n d z like + + + align:start position:0% +times the integral of capital n d z like +that which for our plasma is min-1 / 2N + + align:start position:0% +that which for our plasma is min-1 / 2N + + + align:start position:0% +that which for our plasma is min-1 / 2N +critical integral of gradient of the + + align:start position:0% +critical integral of gradient of the + + + align:start position:0% +critical integral of gradient of the +electron density d + + align:start position:0% + + + + align:start position:0% + +z and this DZ here is going to be + + align:start position:0% +z and this DZ here is going to be + + + align:start position:0% +z and this DZ here is going to be +running from zero to + + align:start position:0% + + + + align:start position:0% + +L + + align:start position:0% +L + + + align:start position:0% +L +now I don't know how clear this is to + + align:start position:0% +now I don't know how clear this is to + + + align:start position:0% +now I don't know how clear this is to +everyone that the the Rays should bend + + align:start position:0% +everyone that the the Rays should bend + + + align:start position:0% +everyone that the the Rays should bend +or that they Bend downwards or why they + + align:start position:0% +or that they Bend downwards or why they + + + align:start position:0% +or that they Bend downwards or why they +Bend there's lots of different ways of + + align:start position:0% +Bend there's lots of different ways of + + + align:start position:0% +Bend there's lots of different ways of +thinking about it you can go and just + + align:start position:0% +thinking about it you can go and just + + + align:start position:0% +thinking about it you can go and just +solve a load of equations if you want to + + align:start position:0% +solve a load of equations if you want to + + + align:start position:0% +solve a load of equations if you want to +I like to think of it and you may laugh + + align:start position:0% +I like to think of it and you may laugh + + + align:start position:0% +I like to think of it and you may laugh +at me for this uh as a bunch of soldiers + + align:start position:0% +at me for this uh as a bunch of soldiers + + + align:start position:0% +at me for this uh as a bunch of soldiers +marching arm in-arm through some mixed + + align:start position:0% +marching arm in-arm through some mixed + + + align:start position:0% +marching arm in-arm through some mixed +terrain here so here's my soldiers I'm + + align:start position:0% +terrain here so here's my soldiers I'm + + + align:start position:0% +terrain here so here's my soldiers I'm +looking them from + + align:start position:0% +looking them from + + + align:start position:0% +looking them from +above you can see how I'm lining them up + + align:start position:0% +above you can see how I'm lining them up + + + align:start position:0% +above you can see how I'm lining them up +nicely with the wave fronts very + + align:start position:0% + + + + align:start position:0% + +suggestively and maybe some of the + + align:start position:0% +suggestively and maybe some of the + + + align:start position:0% +suggestively and maybe some of the +soldiers over here have got some sort of + + align:start position:0% +soldiers over here have got some sort of + + + align:start position:0% +soldiers over here have got some sort of +marsh they've got to walk through and + + align:start position:0% +marsh they've got to walk through and + + + align:start position:0% +marsh they've got to walk through and +these soldiers are going to fall + + align:start position:0% + + + + align:start position:0% + +behind and because they've all linked + + align:start position:0% +behind and because they've all linked + + + align:start position:0% +behind and because they've all linked +arms they've still got to stay in a + + align:start position:0% +arms they've still got to stay in a + + + align:start position:0% +arms they've still got to stay in a +straight line with each other and so as + + align:start position:0% +straight line with each other and so as + + + align:start position:0% +straight line with each other and so as +they go they turn more and more + + align:start position:0% +they go they turn more and more + + + align:start position:0% +they go they turn more and more +round like this and this is what leads + + align:start position:0% +round like this and this is what leads + + + align:start position:0% +round like this and this is what leads +to our bending here and you can make + + align:start position:0% +to our bending here and you can make + + + align:start position:0% +to our bending here and you can make +this a bit more uh you know rigorous if + + align:start position:0% +this a bit more uh you know rigorous if + + + align:start position:0% +this a bit more uh you know rigorous if +you start thinking about the Rays as + + align:start position:0% +you start thinking about the Rays as + + + align:start position:0% +you start thinking about the Rays as +particles and you think about their + + align:start position:0% +particles and you think about their + + + align:start position:0% +particles and you think about their +velocity and you think about the speed + + align:start position:0% +velocity and you think about the speed + + + align:start position:0% +velocity and you think about the speed +that they're going at inside the plasma + + align:start position:0% +that they're going at inside the plasma + + + align:start position:0% +that they're going at inside the plasma +and you realize that they're actually + + align:start position:0% +and you realize that they're actually + + + align:start position:0% +and you realize that they're actually +going slower in the denser regions and + + align:start position:0% +going slower in the denser regions and + + + align:start position:0% +going slower in the denser regions and +that's going to start giving you uh + + align:start position:0% +that's going to start giving you uh + + + align:start position:0% +that's going to start giving you uh +twist sorry they're going faster in the + + align:start position:0% +twist sorry they're going faster in the + + + align:start position:0% +twist sorry they're going faster in the +denser Regions they're going slower in + + align:start position:0% +denser Regions they're going slower in + + + align:start position:0% +denser Regions they're going slower in +the regions with high refractive index + + align:start position:0% +the regions with high refractive index + + + align:start position:0% +the regions with high refractive index +and that's what gives you the bending + + align:start position:0% +and that's what gives you the bending + + + align:start position:0% +and that's what gives you the bending +here so this is just like a little uh + + align:start position:0% +here so this is just like a little uh + + + align:start position:0% +here so this is just like a little uh +mental model to think about when you're + + align:start position:0% +mental model to think about when you're + + + align:start position:0% +mental model to think about when you're +trying to work out why it is that the + + align:start position:0% +trying to work out why it is that the + + + align:start position:0% +trying to work out why it is that the +the Rays of light are turning but + + align:start position:0% +the Rays of light are turning but + + + align:start position:0% +the Rays of light are turning but +there's many many different ways to get + + align:start position:0% + + + + align:start position:0% + +this oh hello hi there is there a + + align:start position:0% +this oh hello hi there is there a + + + align:start position:0% +this oh hello hi there is there a +gradient in density along the uh the Z + + align:start position:0% +gradient in density along the uh the Z + + + align:start position:0% +gradient in density along the uh the Z +axis the way it's drawn it looks like + + align:start position:0% +axis the way it's drawn it looks like + + + align:start position:0% +axis the way it's drawn it looks like +it's only within the y axis it is only + + align:start position:0% +it's only within the y axis it is only + + + align:start position:0% +it's only within the y axis it is only +in the y axis + + align:start position:0% +in the y axis + + + align:start position:0% +in the y axis +yes so then integral of the gradient of + + align:start position:0% +yes so then integral of the gradient of + + + align:start position:0% +yes so then integral of the gradient of +density along Z wouldn't that be + + align:start position:0% +density along Z wouldn't that be + + + align:start position:0% +density along Z wouldn't that be +constant then what is + + align:start position:0% +constant then what is + + + align:start position:0% +constant then what is +it is there no is there a density change + + align:start position:0% +it is there no is there a density change + + + align:start position:0% +it is there no is there a density change +in Z the what I'm asking not in this + + align:start position:0% +in Z the what I'm asking not in this + + + align:start position:0% +in Z the what I'm asking not in this +really simple model I'm proposing of + + align:start position:0% +really simple model I'm proposing of + + + align:start position:0% +really simple model I'm proposing of +course in general there can be a density + + align:start position:0% +course in general there can be a density + + + align:start position:0% +course in general there can be a density +change really this should read + + align:start position:0% +change really this should read + + + align:start position:0% +change really this should read +um radiant of + + align:start position:0% +um radiant of + + + align:start position:0% +um radiant of +density + + align:start position:0% +density + + + align:start position:0% +density +dot DL where L is an + + align:start position:0% +dot DL where L is an + + + align:start position:0% +dot DL where L is an +infimal uh no sorry ignore + + align:start position:0% +infimal uh no sorry ignore + + + align:start position:0% +infimal uh no sorry ignore +that + + align:start position:0% +that + + + align:start position:0% +that +um yeah there was there was no gradient + + align:start position:0% +um yeah there was there was no gradient + + + align:start position:0% +um yeah there was there was no gradient +and density in Z and we don't need one + + align:start position:0% +and density in Z and we don't need one + + + align:start position:0% +and density in Z and we don't need one +to get any bending in fact if there was + + align:start position:0% +to get any bending in fact if there was + + + align:start position:0% +to get any bending in fact if there was +a gradient and density in Z it wouldn't + + align:start position:0% +a gradient and density in Z it wouldn't + + + align:start position:0% +a gradient and density in Z it wouldn't +have any effect on the + + align:start position:0% +have any effect on the + + + align:start position:0% +have any effect on the +light it would just forwards at a + + align:start position:0% +light it would just forwards at a + + + align:start position:0% +light it would just forwards at a +different speed but it wouldn't get + + align:start position:0% +different speed but it wouldn't get + + + align:start position:0% +different speed but it wouldn't get +bent all right and then so but then that + + align:start position:0% +bent all right and then so but then that + + + align:start position:0% +bent all right and then so but then that +roll that it's + + align:start position:0% +roll that it's + + + align:start position:0% +roll that it's +just uh grum and + + align:start position:0% +just uh grum and + + + align:start position:0% +just uh grum and +l oh yes for this very simple model + + align:start position:0% +l oh yes for this very simple model + + + align:start position:0% +l oh yes for this very simple model +you're absolutely right I'm just + + align:start position:0% +you're absolutely right I'm just + + + align:start position:0% +you're absolutely right I'm just +introducing generality because we may + + align:start position:0% +introducing generality because we may + + + align:start position:0% +introducing generality because we may +have something different but you're + + align:start position:0% +have something different but you're + + + align:start position:0% +have something different but you're +quite right so we could write this as + + align:start position:0% +quite right so we could write this as + + + align:start position:0% +quite right so we could write this as +minus 2ncr time L and maybe I put a + + align:start position:0% +minus 2ncr time L and maybe I put a + + + align:start position:0% +minus 2ncr time L and maybe I put a +subscript Zed so that I know that it's + + align:start position:0% +subscript Zed so that I know that it's + + + align:start position:0% +subscript Zed so that I know that it's +like my length scale in Zed and Times by + + align:start position:0% +like my length scale in Zed and Times by + + + align:start position:0% +like my length scale in Zed and Times by +the gradient in NE and if this uh is + + align:start position:0% +the gradient in NE and if this uh is + + + align:start position:0% +the gradient in NE and if this uh is +like some + + align:start position:0% +like some + + + align:start position:0% +like some +simple density ramp so I would have any + + align:start position:0% +simple density ramp so I would have any + + + align:start position:0% +simple density ramp so I would have any +0 * 1us X upon ly or something like that + + align:start position:0% +0 * 1us X upon ly or something like that + + + align:start position:0% +0 * 1us X upon ly or something like that +I could simply put this in and say that + + align:start position:0% +I could simply put this in and say that + + + align:start position:0% +I could simply put this in and say that +the entire beam is now Twisted by a nice + + align:start position:0% +the entire beam is now Twisted by a nice + + + align:start position:0% +the entire beam is now Twisted by a nice +linear angle which has an LZ inside it + + align:start position:0% +linear angle which has an LZ inside it + + + align:start position:0% +linear angle which has an LZ inside it +an + + align:start position:0% +an + + + align:start position:0% +an +ne0 and an + + align:start position:0% + + + + align:start position:0% + +uh minus one upon ly like this so this + + align:start position:0% +uh minus one upon ly like this so this + + + align:start position:0% +uh minus one upon ly like this so this +is if I give you some analytical result + + align:start position:0% +is if I give you some analytical result + + + align:start position:0% +is if I give you some analytical result +you can then go and work out what the + + align:start position:0% +you can then go and work out what the + + + align:start position:0% +you can then go and work out what the +angle would be and that's a super useful + + align:start position:0% +angle would be and that's a super useful + + + align:start position:0% +angle would be and that's a super useful +thing to be able to do uh as I segue + + align:start position:0% +thing to be able to do uh as I segue + + + align:start position:0% +thing to be able to do uh as I segue +perfectly into my next remark which is + + align:start position:0% +perfectly into my next remark which is + + + align:start position:0% +perfectly into my next remark which is +to do with the first problem that this + + align:start position:0% +to do with the first problem that this + + + align:start position:0% +to do with the first problem that this +causes so this is issues with + + align:start position:0% + + + + align:start position:0% + +deflection the first issue is if you've + + align:start position:0% +deflection the first issue is if you've + + + align:start position:0% +deflection the first issue is if you've +got some plasma and you're trying to put + + align:start position:0% +got some plasma and you're trying to put + + + align:start position:0% +got some plasma and you're trying to put +some electromagnetic radiation in it you + + align:start position:0% +some electromagnetic radiation in it you + + + align:start position:0% +some electromagnetic radiation in it you +you want to collect that radiation you + + align:start position:0% +you want to collect that radiation you + + + align:start position:0% +you want to collect that radiation you +want to put it onto a detector maybe + + align:start position:0% +want to put it onto a detector maybe + + + align:start position:0% +want to put it onto a detector maybe +that detector is a camera or it might be + + align:start position:0% +that detector is a camera or it might be + + + align:start position:0% +that detector is a camera or it might be +like a wave guide that you're collecting + + align:start position:0% +like a wave guide that you're collecting + + + align:start position:0% +like a wave guide that you're collecting +microwaves with uh and so that camera + + align:start position:0% +microwaves with uh and so that camera + + + align:start position:0% +microwaves with uh and so that camera +has some physical size right and so + + align:start position:0% +has some physical size right and so + + + align:start position:0% +has some physical size right and so +maybe the camera is represented by this + + align:start position:0% +maybe the camera is represented by this + + + align:start position:0% +maybe the camera is represented by this +lens here it's got some physical size d + + align:start position:0% +lens here it's got some physical size d + + + align:start position:0% +lens here it's got some physical size d +and if your rays get + + align:start position:0% +and if your rays get + + + align:start position:0% +and if your rays get +deflected that was a terrible straight + + align:start position:0% +deflected that was a terrible straight + + + align:start position:0% +deflected that was a terrible straight +line okay if your rays get deflected by + + align:start position:0% +line okay if your rays get deflected by + + + align:start position:0% +line okay if your rays get deflected by +an angle greater than Theta Max where + + align:start position:0% +an angle greater than Theta Max where + + + align:start position:0% +an angle greater than Theta Max where +tangent of theta Max is equal to D over + + align:start position:0% +tangent of theta Max is equal to D over + + + align:start position:0% +tangent of theta Max is equal to D over +2 * + + align:start position:0% +2 * + + + align:start position:0% +2 * +L I forgot to put in this L here there + + align:start position:0% +L I forgot to put in this L here there + + + align:start position:0% +L I forgot to put in this L here there +we go then your ray is going to be lost + + align:start position:0% +we go then your ray is going to be lost + + + align:start position:0% +we go then your ray is going to be lost +so for Theta greater than Theta + + align:start position:0% +so for Theta greater than Theta + + + align:start position:0% +so for Theta greater than Theta +Max you lose your + + align:start position:0% +Max you lose your + + + align:start position:0% +Max you lose your +rays so that means you can't collect + + align:start position:0% +rays so that means you can't collect + + + align:start position:0% +rays so that means you can't collect +them you can't detect them anymore so + + align:start position:0% +them you can't detect them anymore so + + + align:start position:0% +them you can't detect them anymore so +this causes big problems because it + + align:start position:0% +this causes big problems because it + + + align:start position:0% +this causes big problems because it +means that we're going to start losing + + align:start position:0% +means that we're going to start losing + + + align:start position:0% +means that we're going to start losing +lights here and just for most situations + + align:start position:0% +lights here and just for most situations + + + align:start position:0% +lights here and just for most situations +we can use the small angle per aular + + align:start position:0% +we can use the small angle per aular + + + align:start position:0% +we can use the small angle per aular +approximation and just replace the tan + + align:start position:0% +approximation and just replace the tan + + + align:start position:0% +approximation and just replace the tan +Theta with Theta here so that means you + + align:start position:0% +Theta with Theta here so that means you + + + align:start position:0% +Theta with Theta here so that means you +want to keep your deflection angle Theta + + align:start position:0% +want to keep your deflection angle Theta + + + align:start position:0% +want to keep your deflection angle Theta +um which is equal to as we said ddy of + + align:start position:0% +um which is equal to as we said ddy of + + + align:start position:0% +um which is equal to as we said ddy of +the integral of ndl that wants to be + + align:start position:0% +the integral of ndl that wants to be + + + align:start position:0% +the integral of ndl that wants to be +less than beta Max so there's a few + + align:start position:0% +less than beta Max so there's a few + + + align:start position:0% +less than beta Max so there's a few +things that you can do to try and do + + align:start position:0% +things that you can do to try and do + + + align:start position:0% +things that you can do to try and do +this you can have a nice big + + align:start position:0% + + + + align:start position:0% + +lens uh you can have a close lens you + + align:start position:0% +lens uh you can have a close lens you + + + align:start position:0% +lens uh you can have a close lens you +can put it nice and close in or you can + + align:start position:0% +can put it nice and close in or you can + + + align:start position:0% +can put it nice and close in or you can +use a + + align:start position:0% +use a + + + align:start position:0% +use a +shorter wavelength because if you go to + + align:start position:0% +shorter wavelength because if you go to + + + align:start position:0% +shorter wavelength because if you go to +a shorter wavelength uh you get a + + align:start position:0% +a shorter wavelength uh you get a + + + align:start position:0% +a shorter wavelength uh you get a +smaller deflection angle uh which you + + align:start position:0% +smaller deflection angle uh which you + + + align:start position:0% +smaller deflection angle uh which you +can see if you go back to maybe this + + align:start position:0% +can see if you go back to maybe this + + + align:start position:0% +can see if you go back to maybe this +formula here a shter wavelength + + align:start position:0% +formula here a shter wavelength + + + align:start position:0% +formula here a shter wavelength +corresponds to a larger and critical and + + align:start position:0% +corresponds to a larger and critical and + + + align:start position:0% +corresponds to a larger and critical and +so you'll get a smaller Angle now not + + align:start position:0% +so you'll get a smaller Angle now not + + + align:start position:0% +so you'll get a smaller Angle now not +all of these things are possible in a + + align:start position:0% +all of these things are possible in a + + + align:start position:0% +all of these things are possible in a +standard experiment if youve got a toat + + align:start position:0% +standard experiment if youve got a toat + + + align:start position:0% +standard experiment if youve got a toat +uh you may have a limit on how big your + + align:start position:0% +uh you may have a limit on how big your + + + align:start position:0% +uh you may have a limit on how big your +detector can be because it's got to fit + + align:start position:0% +detector can be because it's got to fit + + + align:start position:0% +detector can be because it's got to fit +in a gap between some magnets you'll + + align:start position:0% +in a gap between some magnets you'll + + + align:start position:0% +in a gap between some magnets you'll +certainly have a limit on how close you + + align:start position:0% +certainly have a limit on how close you + + + align:start position:0% +certainly have a limit on how close you +can put it to the plasma because you + + align:start position:0% +can put it to the plasma because you + + + align:start position:0% +can put it to the plasma because you +don't want to stick it right inside um + + align:start position:0% +don't want to stick it right inside um + + + align:start position:0% +don't want to stick it right inside um +and you may not be able to choose + + align:start position:0% +and you may not be able to choose + + + align:start position:0% +and you may not be able to choose +whatever wavelength you want perhaps + + align:start position:0% +whatever wavelength you want perhaps + + + align:start position:0% +whatever wavelength you want perhaps +you're doing looking at electron cyron + + align:start position:0% +you're doing looking at electron cyron + + + align:start position:0% +you're doing looking at electron cyron +emission and you've got no choice but to + + align:start position:0% +emission and you've got no choice but to + + + align:start position:0% +emission and you've got no choice but to +use the wavelength that's admitted that + + align:start position:0% +use the wavelength that's admitted that + + + align:start position:0% +use the wavelength that's admitted that +so this can cause big problems and so if + + align:start position:0% +so this can cause big problems and so if + + + align:start position:0% +so this can cause big problems and so if +you're doing some electromagnetic + + align:start position:0% +you're doing some electromagnetic + + + align:start position:0% +you're doing some electromagnetic +probing of your plasma one of the first + + align:start position:0% +probing of your plasma one of the first + + + align:start position:0% +probing of your plasma one of the first +things you should probably do is check + + align:start position:0% +things you should probably do is check + + + align:start position:0% +things you should probably do is check +whether the density gradients are going + + align:start position:0% +whether the density gradients are going + + + align:start position:0% +whether the density gradients are going +to make it hard to actually measure + + align:start position:0% +to make it hard to actually measure + + + align:start position:0% +to make it hard to actually measure +anything any questions on this + + align:start position:0% + + + + align:start position:0% + +all right so we're now going to plunge + + align:start position:0% +all right so we're now going to plunge + + + align:start position:0% +all right so we're now going to plunge +in our first + + align:start position:0% +in our first + + + align:start position:0% +in our first +Diagnostic and the point I want to make + + align:start position:0% +Diagnostic and the point I want to make + + + align:start position:0% +Diagnostic and the point I want to make +here is although deflection can be + + align:start position:0% +here is although deflection can be + + + align:start position:0% +here is although deflection can be +frustrating it can also be + + align:start position:0% +frustrating it can also be + + + align:start position:0% +frustrating it can also be +useful because we can use it to measure + + align:start position:0% +useful because we can use it to measure + + + align:start position:0% +useful because we can use it to measure +something about the + + align:start position:0% + + + + align:start position:0% + +plasma the first thing we're going to + + align:start position:0% +plasma the first thing we're going to + + + align:start position:0% +plasma the first thing we're going to +talk about is schen Imaging + + align:start position:0% + + + + align:start position:0% + +this word schen people often assume + + align:start position:0% +this word schen people often assume + + + align:start position:0% +this word schen people often assume +refers to a person it does not um so it + + align:start position:0% +refers to a person it does not um so it + + + align:start position:0% +refers to a person it does not um so it +doesn't have a capital S despite what + + align:start position:0% +doesn't have a capital S despite what + + + align:start position:0% +doesn't have a capital S despite what +Obel will tell you uh and it's actually + + align:start position:0% +Obel will tell you uh and it's actually + + + align:start position:0% +Obel will tell you uh and it's actually +after a German word Scher which is like + + align:start position:0% +after a German word Scher which is like + + + align:start position:0% +after a German word Scher which is like +streaks because this was first used for + + align:start position:0% +streaks because this was first used for + + + align:start position:0% +streaks because this was first used for +looking at small imperfections in Optics + + align:start position:0% +looking at small imperfections in Optics + + + align:start position:0% +looking at small imperfections in Optics +uh and so looking at these little + + align:start position:0% +uh and so looking at these little + + + align:start position:0% +uh and so looking at these little +streaks here so it's a way we of Imaging + + align:start position:0% +streaks here so it's a way we of Imaging + + + align:start position:0% +streaks here so it's a way we of Imaging +things which would otherwise be + + align:start position:0% +things which would otherwise be + + + align:start position:0% +things which would otherwise be +impossible to see uh because they cause + + align:start position:0% +impossible to see uh because they cause + + + align:start position:0% +impossible to see uh because they cause +small gradients in refractive + + align:start position:0% +small gradients in refractive + + + align:start position:0% +small gradients in refractive +index so let's have a little example + + align:start position:0% +index so let's have a little example + + + align:start position:0% +index so let's have a little example +building up towards and imaging this + + align:start position:0% +building up towards and imaging this + + + align:start position:0% +building up towards and imaging this +first thing I'm going to show you is not + + align:start position:0% +first thing I'm going to show you is not + + + align:start position:0% +first thing I'm going to show you is not +SCH and imaging this is just Imaging but + + align:start position:0% +SCH and imaging this is just Imaging but + + + align:start position:0% +SCH and imaging this is just Imaging but +my impression is that some folks need a + + align:start position:0% +my impression is that some folks need a + + + align:start position:0% +my impression is that some folks need a +refresher with some Optics so we're + + align:start position:0% +refresher with some Optics so we're + + + align:start position:0% +refresher with some Optics so we're +going to start with a solid object it's + + align:start position:0% +going to start with a solid object it's + + + align:start position:0% +going to start with a solid object it's +going to be this nice little chalice + + align:start position:0% + + + + align:start position:0% + +here and we're going to put in some rays + + align:start position:0% +here and we're going to put in some rays + + + align:start position:0% +here and we're going to put in some rays +of light + + align:start position:0% +of light + + + align:start position:0% +of light +like this now this object is solid and + + align:start position:0% +like this now this object is solid and + + + align:start position:0% +like this now this object is solid and +so it blocks any rays of Light which hit + + align:start position:0% +so it blocks any rays of Light which hit + + + align:start position:0% +so it blocks any rays of Light which hit +it these two Central ones and allows + + align:start position:0% +it these two Central ones and allows + + + align:start position:0% +it these two Central ones and allows +through rays of light going past it + + align:start position:0% +through rays of light going past it + + + align:start position:0% +through rays of light going past it +no allows through rays of light going + + align:start position:0% +no allows through rays of light going + + + align:start position:0% +no allows through rays of light going +past it very + + align:start position:0% + + + + align:start position:0% + +good and what we would probably do here + + align:start position:0% +good and what we would probably do here + + + align:start position:0% +good and what we would probably do here +if we're doing a standard Imaging system + + align:start position:0% +if we're doing a standard Imaging system + + + align:start position:0% +if we're doing a standard Imaging system +is we would have a lens right so this is + + align:start position:0% +is we would have a lens right so this is + + + align:start position:0% +is we would have a lens right so this is +how you form an image so we'll put our + + align:start position:0% +how you form an image so we'll put our + + + align:start position:0% +how you form an image so we'll put our +lens here it's going to have a focal + + align:start position:0% +lens here it's going to have a focal + + + align:start position:0% +lens here it's going to have a focal +length F and we're going to place it at + + align:start position:0% +length F and we're going to place it at + + + align:start position:0% +length F and we're going to place it at +a distance which + + align:start position:0% +a distance which + + + align:start position:0% +a distance which +is 2f away from the object we're trying + + align:start position:0% +is 2f away from the object we're trying + + + align:start position:0% +is 2f away from the object we're trying +to image I'll just put that f up + + align:start position:0% +to image I'll just put that f up + + + align:start position:0% +to image I'll just put that f up +there now behind this lens if we're + + align:start position:0% +there now behind this lens if we're + + + align:start position:0% +there now behind this lens if we're +doing a standard 2f Imaging system we're + + align:start position:0% +doing a standard 2f Imaging system we're + + + align:start position:0% +doing a standard 2f Imaging system we're +going to have a focal point and that's + + align:start position:0% +going to have a focal point and that's + + + align:start position:0% +going to have a focal point and that's +going to be at F away and then we're + + align:start position:0% +going to be at F away and then we're + + + align:start position:0% +going to be at F away and then we're +going to have an object + + align:start position:0% +going to have an object + + + align:start position:0% +going to have an object +plane which is also an F away H sorry an + + align:start position:0% +plane which is also an F away H sorry an + + + align:start position:0% +plane which is also an F away H sorry an +image plane + + align:start position:0% + + + + align:start position:0% + +this is the object + + align:start position:0% + + + + align:start position:0% + +play and this is the length with focal + + align:start position:0% +play and this is the length with focal + + + align:start position:0% +play and this is the length with focal +length F so hopefully some of you have + + align:start position:0% +length F so hopefully some of you have + + + align:start position:0% +length F so hopefully some of you have +seen this sort of thing before you know + + align:start position:0% +seen this sort of thing before you know + + + align:start position:0% +seen this sort of thing before you know +that the Rays will pass through the + + align:start position:0% +that the Rays will pass through the + + + align:start position:0% +that the Rays will pass through the +focal point here he says drawing them + + align:start position:0% + + + + align:start position:0% + +carefully and what we'll end up with + + align:start position:0% + + + + align:start position:0% + +you can't do this on a CH + + align:start position:0% + + + + align:start position:0% + +board is a copy of our image of our + + align:start position:0% +board is a copy of our image of our + + + align:start position:0% +board is a copy of our image of our +object here but it's going to be + + align:start position:0% +object here but it's going to be + + + align:start position:0% +object here but it's going to be +inverted and you can tell that because + + align:start position:0% +inverted and you can tell that because + + + align:start position:0% +inverted and you can tell that because +you can see the Rays have changed place + + align:start position:0% +you can see the Rays have changed place + + + align:start position:0% +you can see the Rays have changed place +so this is a nice one + + align:start position:0% +so this is a nice one + + + align:start position:0% +so this is a nice one +toone + + align:start position:0% +toone + + + align:start position:0% +toone +image it's at + + align:start position:0% +image it's at + + + align:start position:0% +image it's at +magnification one and it is + + align:start position:0% +magnification one and it is + + + align:start position:0% +magnification one and it is +inverted so this is this simplest I + + align:start position:0% +inverted so this is this simplest I + + + align:start position:0% +inverted so this is this simplest I +think the simplest possible Imaging + + align:start position:0% +think the simplest possible Imaging + + + align:start position:0% +think the simplest possible Imaging +system you could possibly develop right + + align:start position:0% +system you could possibly develop right + + + align:start position:0% +system you could possibly develop right +it simply takes whatever is at the + + align:start position:0% +it simply takes whatever is at the + + + align:start position:0% +it simply takes whatever is at the +object plane and puts it at the image FL + + align:start position:0% +object plane and puts it at the image FL + + + align:start position:0% +object plane and puts it at the image FL +some distance + + align:start position:0% +some distance + + + align:start position:0% +some distance +away this could be a microscope this + + align:start position:0% +away this could be a microscope this + + + align:start position:0% +away this could be a microscope this +could be a camera all sorts of things + + align:start position:0% +could be a camera all sorts of things + + + align:start position:0% +could be a camera all sorts of things +like that yes + + align:start position:0% +like that yes + + + align:start position:0% +like that yes +Vincent uh I I think I missed what was F + + align:start position:0% +Vincent uh I I think I missed what was F + + + align:start position:0% +Vincent uh I I think I missed what was F +again I think what what was F like the + + align:start position:0% +again I think what what was F like the + + + align:start position:0% +again I think what what was F like the +focal length of the + + align:start position:0% +focal length of the + + + align:start position:0% +focal length of the +lens thank cool any other questions + + align:start position:0% + + + + align:start position:0% + +okay let's make this more interesting + + align:start position:0% +okay let's make this more interesting + + + align:start position:0% +okay let's make this more interesting +let's put a plasma here + + align:start position:0% + + + + align:start position:0% + +instead okay and we're still going to + + align:start position:0% +instead okay and we're still going to + + + align:start position:0% +instead okay and we're still going to +have our + + align:start position:0% + + + + align:start position:0% + +lens there's still going to be a focal + + align:start position:0% +lens there's still going to be a focal + + + align:start position:0% +lens there's still going to be a focal +point and there's still going to be an + + align:start position:0% +point and there's still going to be an + + + align:start position:0% +point and there's still going to be an +image plane here but the + + align:start position:0% +image plane here but the + + + align:start position:0% +image plane here but the +plasma doesn't block the Rays of light + + align:start position:0% +plasma doesn't block the Rays of light + + + align:start position:0% +plasma doesn't block the Rays of light +as long as we've got for example any + + align:start position:0% +as long as we've got for example any + + + align:start position:0% +as long as we've got for example any +much much less than the critical density + + align:start position:0% +much much less than the critical density + + + align:start position:0% +much much less than the critical density +here so that the Rays can pass through + + align:start position:0% +here so that the Rays can pass through + + + align:start position:0% +here so that the Rays can pass through +easily instead what we're going to have + + align:start position:0% +easily instead what we're going to have + + + align:start position:0% +easily instead what we're going to have +is rays that come + + align:start position:0% + + + + align:start position:0% + +in and then they're going to be + + align:start position:0% +in and then they're going to be + + + align:start position:0% +in and then they're going to be +deflected slightly inside this plasma so + + align:start position:0% +deflected slightly inside this plasma so + + + align:start position:0% +deflected slightly inside this plasma so +I haven't draw drawn the density + + align:start position:0% +I haven't draw drawn the density + + + align:start position:0% +I haven't draw drawn the density +gradients we can imagine we've just got + + align:start position:0% +gradients we can imagine we've just got + + + align:start position:0% +gradients we can imagine we've just got +a whole range of exciting density + + align:start position:0% +a whole range of exciting density + + + align:start position:0% +a whole range of exciting density +gradients that cause some deflections so + + align:start position:0% +gradients that cause some deflections so + + + align:start position:0% +gradients that cause some deflections so +they deflect this Ray slightly downwards + + align:start position:0% +they deflect this Ray slightly downwards + + + align:start position:0% +they deflect this Ray slightly downwards +they deflect this Ray slightly upward + + align:start position:0% +they deflect this Ray slightly upward + + + align:start position:0% +they deflect this Ray slightly upward +they deflect this bottom Ray what have I + + align:start position:0% +they deflect this bottom Ray what have I + + + align:start position:0% +they deflect this bottom Ray what have I +done for this one let's how this one go + + align:start position:0% +done for this one let's how this one go + + + align:start position:0% +done for this one let's how this one go +straight for some reason there's no + + align:start position:0% +straight for some reason there's no + + + align:start position:0% +straight for some reason there's no +density gradient exactly there so the r + + align:start position:0% +density gradient exactly there so the r + + + align:start position:0% +density gradient exactly there so the r +just goes through and this bottom one + + align:start position:0% +just goes through and this bottom one + + + align:start position:0% +just goes through and this bottom one +gets deflected downwards as well and + + align:start position:0% +gets deflected downwards as well and + + + align:start position:0% +gets deflected downwards as well and +let's + + align:start position:0% +let's + + + align:start position:0% +let's +say it just about makes it onto the lens + + align:start position:0% +say it just about makes it onto the lens + + + align:start position:0% +say it just about makes it onto the lens +and I'll move the lens downwards to make + + align:start position:0% +and I'll move the lens downwards to make + + + align:start position:0% +and I'll move the lens downwards to make +that + + align:start position:0% +that + + + align:start position:0% +that +true don't do that on the CH board + + align:start position:0% +true don't do that on the CH board + + + align:start position:0% +true don't do that on the CH board +either okay good so what will the lens + + align:start position:0% +either okay good so what will the lens + + + align:start position:0% +either okay good so what will the lens +due to these Rays + + align:start position:0% + + + + align:start position:0% + +now well it's still going to deflect the + + align:start position:0% +now well it's still going to deflect the + + + align:start position:0% +now well it's still going to deflect the +Rays and it's going to deflect them + + align:start position:0% +Rays and it's going to deflect them + + + align:start position:0% +Rays and it's going to deflect them +let's start with this one that actually + + align:start position:0% +let's start with this one that actually + + + align:start position:0% +let's start with this one that actually +didn't get deflected at all so it angle + + align:start position:0% +didn't get deflected at all so it angle + + + align:start position:0% +didn't get deflected at all so it angle +hasn't changed it's going to go straight + + align:start position:0% +hasn't changed it's going to go straight + + + align:start position:0% +hasn't changed it's going to go straight +through the focal point as as you'd + + align:start position:0% +through the focal point as as you'd + + + align:start position:0% +through the focal point as as you'd +expect this one that was deflected + + align:start position:0% +expect this one that was deflected + + + align:start position:0% +expect this one that was deflected +upwards is going to be deflected down + + align:start position:0% +upwards is going to be deflected down + + + align:start position:0% +upwards is going to be deflected down +but it's going to slightly miss the + + align:start position:0% +but it's going to slightly miss the + + + align:start position:0% +but it's going to slightly miss the +focal point it's going to be slightly + + align:start position:0% +focal point it's going to be slightly + + + align:start position:0% +focal point it's going to be slightly +above it like that this one that was + + align:start position:0% +above it like that this one that was + + + align:start position:0% +above it like that this one that was +deflected downwards is going to be the + + align:start position:0% +deflected downwards is going to be the + + + align:start position:0% +deflected downwards is going to be the +opposite way it's going to be slightly + + align:start position:0% +opposite way it's going to be slightly + + + align:start position:0% +opposite way it's going to be slightly +below the focal point and this one was + + align:start position:0% +below the focal point and this one was + + + align:start position:0% +below the focal point and this one was +reflected uh downwards is also going to + + align:start position:0% +reflected uh downwards is also going to + + + align:start position:0% +reflected uh downwards is also going to +be uh slightly below the focal point and + + align:start position:0% +be uh slightly below the focal point and + + + align:start position:0% +be uh slightly below the focal point and +that was a mistake there we + + align:start position:0% + + + + align:start position:0% + +go there we go it's not a very good + + align:start position:0% +go there we go it's not a very good + + + align:start position:0% +go there we go it's not a very good +image compared to the one I was hoping + + align:start position:0% +image compared to the one I was hoping + + + align:start position:0% +image compared to the one I was hoping +to draw but there we go nothing quite + + align:start position:0% +to draw but there we go nothing quite + + + align:start position:0% +to draw but there we go nothing quite +works out so we should have an image of + + align:start position:0% +works out so we should have an image of + + + align:start position:0% +works out so we should have an image of +our plasma here this image of the plasma + + align:start position:0% +our plasma here this image of the plasma + + + align:start position:0% +our plasma here this image of the plasma +should still be one: + + align:start position:0% +should still be one: + + + align:start position:0% +should still be one: +one mag one + + align:start position:0% +one mag one + + + align:start position:0% +one mag one +and + + align:start position:0% + + + + align:start position:0% + +inverted the fact that I haven't quite + + align:start position:0% +inverted the fact that I haven't quite + + + align:start position:0% +inverted the fact that I haven't quite +managed to get to work is probably just + + align:start position:0% +managed to get to work is probably just + + + align:start position:0% +managed to get to work is probably just +a flaw is how I managed to draw the Rays + + align:start position:0% +a flaw is how I managed to draw the Rays + + + align:start position:0% +a flaw is how I managed to draw the Rays +this time + + align:start position:0% +this time + + + align:start position:0% +this time +around not quite sure what what went + + align:start position:0% +around not quite sure what what went + + + align:start position:0% +around not quite sure what what went +wrong there + + align:start position:0% + + + + align:start position:0% + +looks good on my notes anyway this stuff + + align:start position:0% +looks good on my notes anyway this stuff + + + align:start position:0% +looks good on my notes anyway this stuff +gets a little bit tricky the point is + + align:start position:0% +gets a little bit tricky the point is + + + align:start position:0% +gets a little bit tricky the point is +although the Rays here look like they've + + align:start position:0% +although the Rays here look like they've + + + align:start position:0% +although the Rays here look like they've +all gone upwards slightly they should + + align:start position:0% +all gone upwards slightly they should + + + align:start position:0% +all gone upwards slightly they should +actually still end up in the same places + + align:start position:0% +actually still end up in the same places + + + align:start position:0% +actually still end up in the same places +that they did before and the fact that I + + align:start position:0% +that they did before and the fact that I + + + align:start position:0% +that they did before and the fact that I +can't get it to work right now just + + align:start position:0% +can't get it to work right now just + + + align:start position:0% +can't get it to work right now just +means that I've made a mistake while + + align:start position:0% +means that I've made a mistake while + + + align:start position:0% +means that I've made a mistake while +drawing it live okay good Jack Jack this + + align:start position:0% +drawing it live okay good Jack Jack this + + + align:start position:0% +drawing it live okay good Jack Jack this +said a very basic question but what + + align:start position:0% +said a very basic question but what + + + align:start position:0% +said a very basic question but what +what's the point of having all the Rays + + align:start position:0% +what's the point of having all the Rays + + + align:start position:0% +what's the point of having all the Rays +go through the the trouble of going + + align:start position:0% +go through the the trouble of going + + + align:start position:0% +go through the the trouble of going +through the lens when we could just have + + align:start position:0% +through the lens when we could just have + + + align:start position:0% +through the lens when we could just have +them go straight through and hit our + + align:start position:0% +them go straight through and hit our + + + align:start position:0% +them go straight through and hit our +image plane like I I guess I missed that + + align:start position:0% +image plane like I I guess I missed that + + + align:start position:0% +image plane like I I guess I missed that +up you know what I mean oh yeah + + align:start position:0% +up you know what I mean oh yeah + + + align:start position:0% +up you know what I mean oh yeah +absolutely um so in the top case with + + align:start position:0% +absolutely um so in the top case with + + + align:start position:0% +absolutely um so in the top case with +the solid object the Rays could go if + + align:start position:0% +the solid object the Rays could go if + + + align:start position:0% +the solid object the Rays could go if +the Rays went straight through and hit + + align:start position:0% +the Rays went straight through and hit + + + align:start position:0% +the Rays went straight through and hit +the image plane they will be deflected + + align:start position:0% +the image plane they will be deflected + + + align:start position:0% +the image plane they will be deflected +slightly at the edges and so you'll end + + align:start position:0% +slightly at the edges and so you'll end + + + align:start position:0% +slightly at the edges and so you'll end +up with something fuzzy so it'll be out + + align:start position:0% +up with something fuzzy so it'll be out + + + align:start position:0% +up with something fuzzy so it'll be out +of focus okay so you need a lens to + + align:start position:0% +of focus okay so you need a lens to + + + align:start position:0% +of focus okay so you need a lens to +bring it to focus which effectively is + + align:start position:0% +bring it to focus which effectively is + + + align:start position:0% +bring it to focus which effectively is +mapping the Rays from where they came + + align:start position:0% +mapping the Rays from where they came + + + align:start position:0% +mapping the Rays from where they came +from back to the same place on the + + align:start position:0% +from back to the same place on the + + + align:start position:0% +from back to the same place on the +object plane if you if in the case of + + align:start position:0% +object plane if you if in the case of + + + align:start position:0% +object plane if you if in the case of +the plasma if you don't have the lens + + align:start position:0% +the plasma if you don't have the lens + + + align:start position:0% +the plasma if you don't have the lens +and you just put if you don't have the + + align:start position:0% +and you just put if you don't have the + + + align:start position:0% +and you just put if you don't have the +lens and you just let the Rays propagate + + align:start position:0% +lens and you just let the Rays propagate + + + align:start position:0% +lens and you just let the Rays propagate +to the screen that's a technique called + + align:start position:0% +to the screen that's a technique called + + + align:start position:0% +to the screen that's a technique called +shog graphy which we'll talk about next + + align:start position:0% +shog graphy which we'll talk about next + + + align:start position:0% +shog graphy which we'll talk about next +lecture which I actually think is more + + align:start position:0% +lecture which I actually think is more + + + align:start position:0% +lecture which I actually think is more +difficult even though it's simpler to + + align:start position:0% +difficult even though it's simpler to + + + align:start position:0% +difficult even though it's simpler to +draw and so I want to talk about it + + align:start position:0% +draw and so I want to talk about it + + + align:start position:0% +draw and so I want to talk about it +after this one um + + align:start position:0% +after this one um + + + align:start position:0% +after this one um +so we haven't done anything here at the + + align:start position:0% +so we haven't done anything here at the + + + align:start position:0% +so we haven't done anything here at the +moment and in fact if you do this with a + + align:start position:0% +moment and in fact if you do this with a + + + align:start position:0% +moment and in fact if you do this with a +plasma you won't see anything at all + + align:start position:0% +plasma you won't see anything at all + + + align:start position:0% +plasma you won't see anything at all +because all of the rays are mapped back + + align:start position:0% +because all of the rays are mapped back + + + align:start position:0% +because all of the rays are mapped back +to where they started from and that + + align:start position:0% +to where they started from and that + + + align:start position:0% +to where they started from and that +means that you are going to end up with + + align:start position:0% +means that you are going to end up with + + + align:start position:0% +means that you are going to end up with +uh just the same laser beam that you + + align:start position:0% +uh just the same laser beam that you + + + align:start position:0% +uh just the same laser beam that you +originally started with or the same + + align:start position:0% +originally started with or the same + + + align:start position:0% +originally started with or the same +microwaves you originally started with + + align:start position:0% +microwaves you originally started with + + + align:start position:0% +microwaves you originally started with +so this will be uh invisible so the only + + align:start position:0% +so this will be uh invisible so the only + + + align:start position:0% +so this will be uh invisible so the only +way we can make this visible is to + + align:start position:0% +way we can make this visible is to + + + align:start position:0% +way we can make this visible is to +notice that the Rays do not all pass + + align:start position:0% +notice that the Rays do not all pass + + + align:start position:0% +notice that the Rays do not all pass +through the focal + + align:start position:0% + + + + align:start position:0% + +point now you saw in the case where we + + align:start position:0% +point now you saw in the case where we + + + align:start position:0% +point now you saw in the case where we +did the Imaging that all the Rays did + + align:start position:0% +did the Imaging that all the Rays did + + + align:start position:0% +did the Imaging that all the Rays did +indeed still pass through focal point + + align:start position:0% +indeed still pass through focal point + + + align:start position:0% +indeed still pass through focal point +but here some of them gone above and + + align:start position:0% +but here some of them gone above and + + + align:start position:0% +but here some of them gone above and +some of them gone below and in fact the + + align:start position:0% +some of them gone below and in fact the + + + align:start position:0% +some of them gone below and in fact the +distance they've gone above and the + + align:start position:0% +distance they've gone above and the + + + align:start position:0% +distance they've gone above and the +distance they've gone below is directly + + align:start position:0% +distance they've gone below is directly + + + align:start position:0% +distance they've gone below is directly +proportional to the angle with which + + align:start position:0% +proportional to the angle with which + + + align:start position:0% +proportional to the angle with which +they exited the plasma here and so we + + align:start position:0% +they exited the plasma here and so we + + + align:start position:0% +they exited the plasma here and so we +can learn something about the angle they + + align:start position:0% +can learn something about the angle they + + + align:start position:0% +can learn something about the angle they +can selected uh exited the plasma by + + align:start position:0% +can selected uh exited the plasma by + + + align:start position:0% +can selected uh exited the plasma by +placing a filter at this focal PL and + + align:start position:0% +placing a filter at this focal PL and + + + align:start position:0% +placing a filter at this focal PL and +this filter maybe looks a little bit + + align:start position:0% +this filter maybe looks a little bit + + + align:start position:0% +this filter maybe looks a little bit +like + + align:start position:0% +like + + + align:start position:0% +like +this this filter for example here is + + align:start position:0% +this this filter for example here is + + + align:start position:0% +this this filter for example here is +like a little aperture and it lets + + align:start position:0% +like a little aperture and it lets + + + align:start position:0% +like a little aperture and it lets +through these two rays let me color code + + align:start position:0% +through these two rays let me color code + + + align:start position:0% +through these two rays let me color code +them this one and this one and it blocks + + align:start position:0% +them this one and this one and it blocks + + + align:start position:0% +them this one and this one and it blocks +off these two + + align:start position:0% +off these two + + + align:start position:0% +off these two +rays and so lights coming from that bit + + align:start position:0% +rays and so lights coming from that bit + + + align:start position:0% +rays and so lights coming from that bit +of the plasma where the density + + align:start position:0% +of the plasma where the density + + + align:start position:0% +of the plasma where the density +gradients were large will be blocked it + + align:start position:0% +gradients were large will be blocked it + + + align:start position:0% +gradients were large will be blocked it +will no longer appear on our final image + + align:start position:0% +will no longer appear on our final image + + + align:start position:0% +will no longer appear on our final image +and this is what schan Imaging is so we + + align:start position:0% +and this is what schan Imaging is so we + + + align:start position:0% +and this is what schan Imaging is so we +place + + align:start position:0% +place + + + align:start position:0% +place +a a + + align:start position:0% +a a + + + align:start position:0% +a a +stop at the focal play + + align:start position:0% + + + + align:start position:0% + +and we + + align:start position:0% +and we + + + align:start position:0% +and we +filter by + + align:start position:0% + + + + align:start position:0% + +angle I'm going to do some exhaustive + + align:start position:0% +angle I'm going to do some exhaustive + + + align:start position:0% +angle I'm going to do some exhaustive +examples of this to try and build some + + align:start position:0% +examples of this to try and build some + + + align:start position:0% +examples of this to try and build some +intuition for what's going on if you're + + align:start position:0% +intuition for what's going on if you're + + + align:start position:0% +intuition for what's going on if you're +a little bit confused right now any + + align:start position:0% +a little bit confused right now any + + + align:start position:0% +a little bit confused right now any +questions on this before we keep going + + align:start position:0% + + + + align:start position:0% + +I have sort of a overall conceptual + + align:start position:0% +I have sort of a overall conceptual + + + align:start position:0% +I have sort of a overall conceptual +question I feel like the highest + + align:start position:0% +question I feel like the highest + + + align:start position:0% +question I feel like the highest +gradients a lot of the time are well + + align:start position:0% +gradients a lot of the time are well + + + align:start position:0% +gradients a lot of the time are well +maybe this isn't quite true but I can + + align:start position:0% +maybe this isn't quite true but I can + + + align:start position:0% +maybe this isn't quite true but I can +imagine a lot of cases it's going to be + + align:start position:0% +imagine a lot of cases it's going to be + + + align:start position:0% +imagine a lot of cases it's going to be +affected most by the edges where it's + + align:start position:0% +affected most by the edges where it's + + + align:start position:0% +affected most by the edges where it's +entering and leaving the plasma because + + align:start position:0% +entering and leaving the plasma because + + + align:start position:0% +entering and leaving the plasma because +you're you know depending on how uniform + + align:start position:0% +you're you know depending on how uniform + + + align:start position:0% +you're you know depending on how uniform +things are so just curious what you + + align:start position:0% +things are so just curious what you + + + align:start position:0% +things are so just curious what you +actually get an image of I mean if you + + align:start position:0% +actually get an image of I mean if you + + + align:start position:0% +actually get an image of I mean if you +especially you don't have a great sense + + align:start position:0% +especially you don't have a great sense + + + align:start position:0% +especially you don't have a great sense +of where the the gradients are or if you + + align:start position:0% +of where the the gradients are or if you + + + align:start position:0% +of where the the gradients are or if you +have the gradients inside don't know + + align:start position:0% +have the gradients inside don't know + + + align:start position:0% +have the gradients inside don't know +about + + align:start position:0% +about + + + align:start position:0% +about +or yeah absolutely um these images are + + align:start position:0% +or yeah absolutely um these images are + + + align:start position:0% +or yeah absolutely um these images are +difficult to interpret so this is not a + + align:start position:0% +difficult to interpret so this is not a + + + align:start position:0% +difficult to interpret so this is not a +generic diagnostic technique that will + + align:start position:0% +generic diagnostic technique that will + + + align:start position:0% +generic diagnostic technique that will +immediately tell you what's going on you + + align:start position:0% +immediately tell you what's going on you + + + align:start position:0% +immediately tell you what's going on you +need to know something about your plasma + + align:start position:0% +need to know something about your plasma + + + align:start position:0% +need to know something about your plasma +maybe you have a simulation and you do a + + align:start position:0% +maybe you have a simulation and you do a + + + align:start position:0% +maybe you have a simulation and you do a +synthetic diagnostic on it or maybe + + align:start position:0% +synthetic diagnostic on it or maybe + + + align:start position:0% +synthetic diagnostic on it or maybe +you've set up your experiment such it's + + align:start position:0% +you've set up your experiment such it's + + + align:start position:0% +you've set up your experiment such it's +particularly simple and we'll talk a + + align:start position:0% +particularly simple and we'll talk a + + + align:start position:0% +particularly simple and we'll talk a +little bit about some simple + + align:start position:0% +little bit about some simple + + + align:start position:0% +little bit about some simple +distributions and what patterns they + + align:start position:0% +distributions and what patterns they + + + align:start position:0% +distributions and what patterns they +make and that will give us an idea for + + align:start position:0% +make and that will give us an idea for + + + align:start position:0% +make and that will give us an idea for +what sorts of things we might be able to + + align:start position:0% +what sorts of things we might be able to + + + align:start position:0% +what sorts of things we might be able to +measure with this but like a a turbul + + align:start position:0% +measure with this but like a a turbul + + + align:start position:0% +measure with this but like a a turbul +like turbulence in the edge of a toac or + + align:start position:0% +like turbulence in the edge of a toac or + + + align:start position:0% +like turbulence in the edge of a toac or +something like that is maybe not the + + align:start position:0% +something like that is maybe not the + + + align:start position:0% +something like that is maybe not the +ideal diagnostic for it fair enough yes + + align:start position:0% +ideal diagnostic for it fair enough yes + + + align:start position:0% +ideal diagnostic for it fair enough yes +and and just I want to make very clear + + align:start position:0% +and and just I want to make very clear + + + align:start position:0% +and and just I want to make very clear +because I I don't know if it came across + + align:start position:0% +because I I don't know if it came across + + + align:start position:0% +because I I don't know if it came across +um when we were talking about it before + + align:start position:0% +um when we were talking about it before + + + align:start position:0% +um when we were talking about it before +but we're we're we only get deflections + + align:start position:0% +but we're we're we only get deflections + + + align:start position:0% +but we're we're we only get deflections +from density gradients which are + + align:start position:0% +from density gradients which are + + + align:start position:0% +from density gradients which are +perpendicular to the direction here so + + align:start position:0% +perpendicular to the direction here so + + + align:start position:0% +perpendicular to the direction here so +if our Ray is going in this direction in + + align:start position:0% +if our Ray is going in this direction in + + + align:start position:0% +if our Ray is going in this direction in +the Z direction we + + align:start position:0% +the Z direction we + + + align:start position:0% +the Z direction we +sense D Dy of NE and D DX of NE but we + + align:start position:0% +sense D Dy of NE and D DX of NE but we + + + align:start position:0% +sense D Dy of NE and D DX of NE but we +do not + + align:start position:0% +do not + + + align:start position:0% +do not +sense d d z of NE so if there's density + + align:start position:0% +sense d d z of NE so if there's density + + + align:start position:0% +sense d d z of NE so if there's density +gradients in the direction the ray is + + align:start position:0% +gradients in the direction the ray is + + + align:start position:0% +gradients in the direction the ray is +propagating the ray will slow down or + + align:start position:0% +propagating the ray will slow down or + + + align:start position:0% +propagating the ray will slow down or +speed up but it won't actually deflect + + align:start position:0% +speed up but it won't actually deflect + + + align:start position:0% +speed up but it won't actually deflect +from that and so that helps you a little + + align:start position:0% +from that and so that helps you a little + + + align:start position:0% +from that and so that helps you a little +bit you're only sensitive to gradients + + align:start position:0% +bit you're only sensitive to gradients + + + align:start position:0% +bit you're only sensitive to gradients +perpendicular to the probing direction + + align:start position:0% +perpendicular to the probing direction + + + align:start position:0% +perpendicular to the probing direction +that might also tell you if you've got a + + align:start position:0% +that might also tell you if you've got a + + + align:start position:0% +that might also tell you if you've got a +plasma which you think has some geometry + + align:start position:0% +plasma which you think has some geometry + + + align:start position:0% +plasma which you think has some geometry +there may be a good direction to send + + align:start position:0% +there may be a good direction to send + + + align:start position:0% +there may be a good direction to send +the probing beam through there may be a + + align:start position:0% +the probing beam through there may be a + + + align:start position:0% +the probing beam through there may be a +bad Direction so you want to think about + + align:start position:0% +bad Direction so you want to think about + + + align:start position:0% +bad Direction so you want to think about +that a little bit + + align:start position:0% + + + + align:start position:0% + +so let's have a talk about some of these + + align:start position:0% +so let's have a talk about some of these + + + align:start position:0% +so let's have a talk about some of these +uh stops right so I've said that we can + + align:start position:0% +uh stops right so I've said that we can + + + align:start position:0% +uh stops right so I've said that we can +place these stops here let's have a chat + + align:start position:0% +place these stops here let's have a chat + + + align:start position:0% +place these stops here let's have a chat +about what sort of different stops are + + align:start position:0% +about what sort of different stops are + + + align:start position:0% +about what sort of different stops are +available to + + align:start position:0% +available to + + + align:start position:0% +available to +us so types of + + align:start position:0% + + + + align:start position:0% + +stop the first type is to decide whether + + align:start position:0% +stop the first type is to decide whether + + + align:start position:0% +stop the first type is to decide whether +our stop is going to be dark field or + + align:start position:0% +our stop is going to be dark field or + + + align:start position:0% +our stop is going to be dark field or +light field so I'm putting dark in + + align:start position:0% +light field so I'm putting dark in + + + align:start position:0% +light field so I'm putting dark in +Brackets because it will save me writing + + align:start position:0% +Brackets because it will save me writing + + + align:start position:0% +Brackets because it will save me writing +in a moment + + align:start position:0% +in a moment + + + align:start position:0% +in a moment +the difference between dark field and + + align:start position:0% +the difference between dark field and + + + align:start position:0% +the difference between dark field and +light field is that the dark field + + align:start position:0% +light field is that the dark field + + + align:start position:0% +light field is that the dark field +blocks undeflected + + align:start position:0% +blocks undeflected + + + align:start position:0% +blocks undeflected +Rays so ones that do pass through the + + align:start position:0% +Rays so ones that do pass through the + + + align:start position:0% +Rays so ones that do pass through the +focal point and the light field blocks + + align:start position:0% +focal point and the light field blocks + + + align:start position:0% +focal point and the light field blocks +deflected Rays ones which do not pass + + align:start position:0% +deflected Rays ones which do not pass + + + align:start position:0% +deflected Rays ones which do not pass +through the focal point so you can + + align:start position:0% +through the focal point so you can + + + align:start position:0% +through the focal point so you can +either look for Regions where there are + + align:start position:0% +either look for Regions where there are + + + align:start position:0% +either look for Regions where there are +density gradients or where there aren't + + align:start position:0% +density gradients or where there aren't + + + align:start position:0% +density gradients or where there aren't +density gradients we can also choose the + + align:start position:0% +density gradients we can also choose the + + + align:start position:0% +density gradients we can also choose the +shape of our stop because our stop uh is + + align:start position:0% +shape of our stop because our stop uh is + + + align:start position:0% +shape of our stop because our stop uh is +sort of a two diens dimensional plane at + + align:start position:0% +sort of a two diens dimensional plane at + + + align:start position:0% +sort of a two diens dimensional plane at +the focal plane here so we could have a + + align:start position:0% +the focal plane here so we could have a + + + align:start position:0% +the focal plane here so we could have a +circular + + align:start position:0% +circular + + + align:start position:0% +circular +stop and that doesn't care what + + align:start position:0% +stop and that doesn't care what + + + align:start position:0% +stop and that doesn't care what +direction the ray is deflected in it + + align:start position:0% +direction the ray is deflected in it + + + align:start position:0% +direction the ray is deflected in it +only cares on the size of the angle so + + align:start position:0% +only cares on the size of the angle so + + + align:start position:0% +only cares on the size of the angle so +the size of theta so that is basically + + align:start position:0% +the size of theta so that is basically + + + align:start position:0% +the size of theta so that is basically +are there any large density gradients or + + align:start position:0% +are there any large density gradients or + + + align:start position:0% +are there any large density gradients or +we could have what's called a knife + + align:start position:0% +we could have what's called a knife + + + align:start position:0% +we could have what's called a knife +edge which is + + align:start position:0% +edge which is + + + align:start position:0% +edge which is +linear + + align:start position:0% +linear + + + align:start position:0% +linear +uh like this and that is sensitive to + + align:start position:0% +uh like this and that is sensitive to + + + align:start position:0% +uh like this and that is sensitive to +density gradients in Only One Direction + + align:start position:0% +density gradients in Only One Direction + + + align:start position:0% +density gradients in Only One Direction +and it still cares about the size of the + + align:start position:0% +and it still cares about the size of the + + + align:start position:0% +and it still cares about the size of the +density gradient I'll WR that it's like + + align:start position:0% +density gradient I'll WR that it's like + + + align:start position:0% +density gradient I'll WR that it's like +X hat + + align:start position:0% +X hat + + + align:start position:0% +X hat +here so we could for example + + align:start position:0% +here so we could for example + + + align:start position:0% +here so we could for example +have a + + align:start position:0% +have a + + + align:start position:0% +have a +scop at the focal plane no it's not + + align:start position:0% +scop at the focal plane no it's not + + + align:start position:0% +scop at the focal plane no it's not +going to do + + align:start position:0% + + + + align:start position:0% + +it okay fine I can't get a nice round + + align:start position:0% +it okay fine I can't get a nice round + + + align:start position:0% +it okay fine I can't get a nice round +circle we could have a stop which is an + + align:start position:0% +circle we could have a stop which is an + + + align:start position:0% +circle we could have a stop which is an +opening inside an opaque sheet of + + align:start position:0% +opening inside an opaque sheet of + + + align:start position:0% +opening inside an opaque sheet of +material here and this opening could be + + align:start position:0% +material here and this opening could be + + + align:start position:0% +material here and this opening could be +positioned such that the focal + + align:start position:0% +positioned such that the focal + + + align:start position:0% +positioned such that the focal +spot in the absence of any plasma sits + + align:start position:0% +spot in the absence of any plasma sits + + + align:start position:0% +spot in the absence of any plasma sits +inside it what sort of stop would this + + align:start position:0% + + + + align:start position:0% + +be light field so this is a light field + + align:start position:0% +be light field so this is a light field + + + align:start position:0% +be light field so this is a light field +stop and what shape is it + + align:start position:0% + + + + align:start position:0% + +the best yes okay Circle thank + + align:start position:0% + + + + align:start position:0% + +you uh we could also have a stock that + + align:start position:0% + + + + align:start position:0% + +looks like + + align:start position:0% + + + + align:start position:0% + +this and we can position it such that + + align:start position:0% +this and we can position it such that + + + align:start position:0% +this and we can position it such that +the focal spot is actually within the + + align:start position:0% +the focal spot is actually within the + + + align:start position:0% +the focal spot is actually within the +opaque region and what sort of slot + + align:start position:0% +opaque region and what sort of slot + + + align:start position:0% +opaque region and what sort of slot +would this be + + align:start position:0% + + + + align:start position:0% + +dark field dark field okay dark field + + align:start position:0% +dark field dark field okay dark field + + + align:start position:0% +dark field dark field okay dark field +and what shape is + + align:start position:0% +and what shape is + + + align:start position:0% +and what shape is +it + + align:start position:0% +it + + + align:start position:0% +it +linear so a knife edge here + + align:start position:0% +linear so a knife edge here + + + align:start position:0% +linear so a knife edge here +yeah we call it a knife edge because + + align:start position:0% +yeah we call it a knife edge because + + + align:start position:0% +yeah we call it a knife edge because +actually using a razor blade is a pretty + + align:start position:0% +actually using a razor blade is a pretty + + + align:start position:0% +actually using a razor blade is a pretty +good thing to have because you get a + + align:start position:0% +good thing to have because you get a + + + align:start position:0% +good thing to have because you get a +very nice sharp uniform Edge to it okay + + align:start position:0% +very nice sharp uniform Edge to it okay + + + align:start position:0% +very nice sharp uniform Edge to it okay +and so depending on these stops you can + + align:start position:0% +and so depending on these stops you can + + + align:start position:0% +and so depending on these stops you can +think of as filters in angle space right + + align:start position:0% +think of as filters in angle space right + + + align:start position:0% +think of as filters in angle space right +so they allow through certain angles you + + align:start position:0% +so they allow through certain angles you + + + align:start position:0% +so they allow through certain angles you +can think of arbitrarily complicated + + align:start position:0% +can think of arbitrarily complicated + + + align:start position:0% +can think of arbitrarily complicated +versions of this there's a a technique + + align:start position:0% +versions of this there's a a technique + + + align:start position:0% +versions of this there's a a technique +called um angular not Fringe angular + + align:start position:0% +called um angular not Fringe angular + + + align:start position:0% +called um angular not Fringe angular +filter refractometry which has a set of + + align:start position:0% +filter refractometry which has a set of + + + align:start position:0% +filter refractometry which has a set of +nested anuli which let + + align:start position:0% +nested anuli which let + + + align:start position:0% +nested anuli which let +through uh light which has been + + align:start position:0% +through uh light which has been + + + align:start position:0% +through uh light which has been +deflected by certain specific angles so + + align:start position:0% +deflected by certain specific angles so + + + align:start position:0% +deflected by certain specific angles so +you know the world is your oyster you + + align:start position:0% +you know the world is your oyster you + + + align:start position:0% +you know the world is your oyster you +can come up with all sorts of exciting + + align:start position:0% +can come up with all sorts of exciting + + + align:start position:0% +can come up with all sorts of exciting +different stops if you want to one thing + + align:start position:0% +different stops if you want to one thing + + + align:start position:0% +different stops if you want to one thing +I will note is that the D dynamic range + + align:start position:0% +I will note is that the D dynamic range + + + align:start position:0% +I will note is that the D dynamic range +of your diagnostic which we'll talk + + align:start position:0% +of your diagnostic which we'll talk + + + align:start position:0% +of your diagnostic which we'll talk +about more later depends a great deal on + + align:start position:0% +about more later depends a great deal on + + + align:start position:0% +about more later depends a great deal on +your focal spot + + align:start position:0% +your focal spot + + + align:start position:0% +your focal spot +size so I've shown these focal spots to + + align:start position:0% +size so I've shown these focal spots to + + + align:start position:0% +size so I've shown these focal spots to +be relatively small here uh but that + + align:start position:0% +be relatively small here uh but that + + + align:start position:0% +be relatively small here uh but that +focal spot size at least in a defraction + + align:start position:0% +focal spot size at least in a defraction + + + align:start position:0% +focal spot size at least in a defraction +limited sense it covers an angle which + + align:start position:0% +limited sense it covers an angle which + + + align:start position:0% +limited sense it covers an angle which +is equal to the wavelength of your light + + align:start position:0% +is equal to the wavelength of your light + + + align:start position:0% +is equal to the wavelength of your light +over the size of your lens the diameter + + align:start position:0% +over the size of your lens the diameter + + + align:start position:0% +over the size of your lens the diameter +of your lens here and so you might end + + align:start position:0% +of your lens here and so you might end + + + align:start position:0% +of your lens here and so you might end +up having focal spots which are are not + + align:start position:0% +up having focal spots which are are not + + + align:start position:0% +up having focal spots which are are not +small but actually could be rather large + + align:start position:0% +small but actually could be rather large + + + align:start position:0% +small but actually could be rather large +and then part of the focal spot could be + + align:start position:0% +and then part of the focal spot could be + + + align:start position:0% +and then part of the focal spot could be +obscured and part of the focal spot + + align:start position:0% +obscured and part of the focal spot + + + align:start position:0% +obscured and part of the focal spot +could be clear for some given deflection + + align:start position:0% +could be clear for some given deflection + + + align:start position:0% +could be clear for some given deflection +angle so and in general when we've got a + + align:start position:0% +angle so and in general when we've got a + + + align:start position:0% +angle so and in general when we've got a +plasma + + align:start position:0% +plasma + + + align:start position:0% +plasma +here we have say a small focal spot + + align:start position:0% +here we have say a small focal spot + + + align:start position:0% +here we have say a small focal spot +before we put uh any Plasma in the way + + align:start position:0% +before we put uh any Plasma in the way + + + align:start position:0% +before we put uh any Plasma in the way +when the Plasma's gone in the way + + align:start position:0% +when the Plasma's gone in the way + + + align:start position:0% +when the Plasma's gone in the way +different rays of Light have being + + align:start position:0% +different rays of Light have being + + + align:start position:0% +different rays of Light have being +deflected by different amounts so this + + align:start position:0% +deflected by different amounts so this + + + align:start position:0% +deflected by different amounts so this +thing may take on some complicated + + align:start position:0% +thing may take on some complicated + + + align:start position:0% +thing may take on some complicated +shape here and this is the shape that + + align:start position:0% +shape here and this is the shape that + + + align:start position:0% +shape here and this is the shape that +you're filtering you might be filtering + + align:start position:0% +you're filtering you might be filtering + + + align:start position:0% +you're filtering you might be filtering +it with your knife edge like this or you + + align:start position:0% +it with your knife edge like this or you + + + align:start position:0% +it with your knife edge like this or you +might be filtering it with your circular + + align:start position:0% +might be filtering it with your circular + + + align:start position:0% +might be filtering it with your circular +stop like this so we're basically + + align:start position:0% +stop like this so we're basically + + + align:start position:0% +stop like this so we're basically +filtering the Rays based on how far + + align:start position:0% +filtering the Rays based on how far + + + align:start position:0% +filtering the Rays based on how far +they've been deflected but the focal + + align:start position:0% +they've been deflected but the focal + + + align:start position:0% +they've been deflected but the focal +plane there's no information about where + + align:start position:0% +plane there's no information about where + + + align:start position:0% +plane there's no information about where +the Rays came from inside their plasma + + align:start position:0% +the Rays came from inside their plasma + + + align:start position:0% +the Rays came from inside their plasma +so their spatial information has been + + align:start position:0% +so their spatial information has been + + + align:start position:0% +so their spatial information has been +lost the only thing we know about them + + align:start position:0% +lost the only thing we know about them + + + align:start position:0% +lost the only thing we know about them +is their angular uh position so rays + + align:start position:0% +is their angular uh position so rays + + + align:start position:0% +is their angular uh position so rays +which are deflected by an angle Theta + + align:start position:0% +which are deflected by an angle Theta + + + align:start position:0% +which are deflected by an angle Theta +one from at the top of the plasma and + + align:start position:0% +one from at the top of the plasma and + + + align:start position:0% +one from at the top of the plasma and +rays which are deflected by the same + + align:start position:0% +rays which are deflected by the same + + + align:start position:0% +rays which are deflected by the same +angle from the bottom of plasma end up + + align:start position:0% +angle from the bottom of plasma end up + + + align:start position:0% +angle from the bottom of plasma end up +at the same place in the focal plane um + + align:start position:0% +at the same place in the focal plane um + + + align:start position:0% +at the same place in the focal plane um +even though they came from different + + align:start position:0% +even though they came from different + + + align:start position:0% +even though they came from different +parts of the plas this is the magic of + + align:start position:0% +parts of the plas this is the magic of + + + align:start position:0% +parts of the plas this is the magic of +geometric + + align:start position:0% +geometric + + + align:start position:0% +geometric +optics so any questions on this or + + align:start position:0% +optics so any questions on this or + + + align:start position:0% +optics so any questions on this or +should we do a a little + + align:start position:0% + + + + align:start position:0% + +example okay let's do our + + align:start position:0% +example okay let's do our + + + align:start position:0% +example okay let's do our +example so let us + + align:start position:0% +example so let us + + + align:start position:0% +example so let us +consider a very simple plasma + + align:start position:0% +consider a very simple plasma + + + align:start position:0% +consider a very simple plasma +this + + align:start position:0% + + + + align:start position:0% + +plasma will have the coordinate system y + + align:start position:0% +plasma will have the coordinate system y + + + align:start position:0% +plasma will have the coordinate system y +vertically and we'll have Zs in the + + align:start position:0% +vertically and we'll have Zs in the + + + align:start position:0% +vertically and we'll have Zs in the +direction of propagation as we discussed + + align:start position:0% +direction of propagation as we discussed + + + align:start position:0% +direction of propagation as we discussed +before um we'll have Rays oh well I'll + + align:start position:0% +before um we'll have Rays oh well I'll + + + align:start position:0% +before um we'll have Rays oh well I'll +draw the plasma first so the plasma is + + align:start position:0% +draw the plasma first so the plasma is + + + align:start position:0% +draw the plasma first so the plasma is +going to have a density distribution + + align:start position:0% +going to have a density distribution + + + align:start position:0% +going to have a density distribution +that sort of looks gaussian is some sort + + align:start position:0% +that sort of looks gaussian is some sort + + + align:start position:0% +that sort of looks gaussian is some sort +of nice Peak + + align:start position:0% + + + + align:start position:0% + +function so this is density and + + align:start position:0% +function so this is density and + + + align:start position:0% +function so this is density and +so you can think about this for example + + align:start position:0% +so you can think about this for example + + + align:start position:0% +so you can think about this for example +as like a cylinder so you've got a + + align:start position:0% +as like a cylinder so you've got a + + + align:start position:0% +as like a cylinder so you've got a +cylinder of plasma like a z pinch and + + align:start position:0% +cylinder of plasma like a z pinch and + + + align:start position:0% +cylinder of plasma like a z pinch and +you're probing down the axis of this Z + + align:start position:0% +you're probing down the axis of this Z + + + align:start position:0% +you're probing down the axis of this Z +pinch and it's got a gouon distribution + + align:start position:0% +pinch and it's got a gouon distribution + + + align:start position:0% +pinch and it's got a gouon distribution +of density to it um anything like that + + align:start position:0% +of density to it um anything like that + + + align:start position:0% +of density to it um anything like that +and then we'll have the Rays of light + + align:start position:0% +and then we'll have the Rays of light + + + align:start position:0% +and then we'll have the Rays of light +coming through so we'll have rays of + + align:start position:0% +coming through so we'll have rays of + + + align:start position:0% +coming through so we'll have rays of +Light which are sampling very small + + align:start position:0% +Light which are sampling very small + + + align:start position:0% +Light which are sampling very small +density gradients at the edges here and + + align:start position:0% +density gradients at the edges here and + + + align:start position:0% +density gradients at the edges here and +these + + align:start position:0% +these + + + align:start position:0% +these +rays will just go straight through + + align:start position:0% + + + + align:start position:0% + +there's also be a ray that goes through + + align:start position:0% +there's also be a ray that goes through + + + align:start position:0% +there's also be a ray that goes through +the center which also sees a very small + + align:start position:0% +the center which also sees a very small + + + align:start position:0% +the center which also sees a very small +density gradient here right right at the + + align:start position:0% +density gradient here right right at the + + + align:start position:0% +density gradient here right right at the +center of this distribution the density + + align:start position:0% +center of this distribution the density + + + align:start position:0% +center of this distribution the density +gradient is zero but the edges here + + align:start position:0% +gradient is zero but the edges here + + + align:start position:0% +gradient is zero but the edges here +where the density gradient is large will + + align:start position:0% +where the density gradient is large will + + + align:start position:0% +where the density gradient is large will +have some + + align:start position:0% + + + + align:start position:0% + +deflection and if we place our lens as + + align:start position:0% +deflection and if we place our lens as + + + align:start position:0% +deflection and if we place our lens as +we did + + align:start position:0% +we did + + + align:start position:0% +we did +before some distance away it's going to + + align:start position:0% +before some distance away it's going to + + + align:start position:0% +before some distance away it's going to +focus those Rays onto our focal + + align:start position:0% +focus those Rays onto our focal + + + align:start position:0% +focus those Rays onto our focal +plane and in our focal plane we're going + + align:start position:0% +plane and in our focal plane we're going + + + align:start position:0% +plane and in our focal plane we're going +to put some sort of stop here so the + + align:start position:0% +to put some sort of stop here so the + + + align:start position:0% +to put some sort of stop here so the +undeflected rays are just going to + + align:start position:0% +undeflected rays are just going to + + + align:start position:0% +undeflected rays are just going to +go + + align:start position:0% +go + + + align:start position:0% +go +uh straight through the focal point + + align:start position:0% + + + + align:start position:0% + +that but the deflected rays are not + + align:start position:0% +that but the deflected rays are not + + + align:start position:0% +that but the deflected rays are not +going to go through the focal point + + align:start position:0% +going to go through the focal point + + + align:start position:0% +going to go through the focal point +right the deflected rays are going to go + + align:start position:0% + + + + align:start position:0% + +above and + + align:start position:0% + + + + align:start position:0% + +below so now we can put a series of + + align:start position:0% +below so now we can put a series of + + + align:start position:0% +below so now we can put a series of +stops inside here so we could have a + + align:start position:0% + + + + align:start position:0% + +stop and that blue dash line that looks + + align:start position:0% + + + + align:start position:0% + +like a light + + align:start position:0% +like a light + + + align:start position:0% +like a light +field knife + + align:start position:0% +field knife + + + align:start position:0% +field knife +edge we could have a stop that looks + + align:start position:0% + + + + align:start position:0% + +like dark field life + + align:start position:0% +like dark field life + + + align:start position:0% +like dark field life +Edge we could have a stop that looks + + align:start position:0% + + + + align:start position:0% + +like a light field Circle + + align:start position:0% +like a light field Circle + + + align:start position:0% +like a light field Circle +and we could have a stop that looks + + align:start position:0% + + + + align:start position:0% + +like a dark field Circle and what we're + + align:start position:0% +like a dark field Circle and what we're + + + align:start position:0% +like a dark field Circle and what we're +going to do is sketch out what we expect + + align:start position:0% +going to do is sketch out what we expect + + + align:start position:0% +going to do is sketch out what we expect +the intensity to look like from each of + + align:start position:0% +the intensity to look like from each of + + + align:start position:0% +the intensity to look like from each of +these different uh knife edges + + align:start position:0% +these different uh knife edges + + + align:start position:0% +these different uh knife edges +here so if I + + align:start position:0% + + + + align:start position:0% + +plot one + + align:start position:0% + + + + align:start position:0% + +I'll just draw the density distribution + + align:start position:0% +I'll just draw the density distribution + + + align:start position:0% +I'll just draw the density distribution +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +again like that so that's our density + + align:start position:0% +again like that so that's our density + + + align:start position:0% +again like that so that's our density +now we want to know what our intensity + + align:start position:0% +now we want to know what our intensity + + + align:start position:0% +now we want to know what our intensity +distribution looks like so this is now + + align:start position:0% +distribution looks like so this is now + + + align:start position:0% +distribution looks like so this is now +intensity we have our initial intensity + + align:start position:0% +intensity we have our initial intensity + + + align:start position:0% +intensity we have our initial intensity +one and we have zero intensity + + align:start position:0% +one and we have zero intensity + + + align:start position:0% +one and we have zero intensity +corresponding to all the Rays being + + align:start position:0% +corresponding to all the Rays being + + + align:start position:0% +corresponding to all the Rays being +blocked so where for the light field + + align:start position:0% +blocked so where for the light field + + + align:start position:0% +blocked so where for the light field +knife edge do we see no intensity + + align:start position:0% + + + + align:start position:0% + +sorry I didn't have that proper can you + + align:start position:0% +sorry I didn't have that proper can you + + + align:start position:0% +sorry I didn't have that proper can you +say it + + align:start position:0% + + + + align:start position:0% + +again so I think what you said was in + + align:start position:0% +again so I think what you said was in + + + align:start position:0% +again so I think what you said was in +the upper side uh where there's the + + align:start position:0% +the upper side uh where there's the + + + align:start position:0% +the upper side uh where there's the +largest density gradient right so this + + align:start position:0% +largest density gradient right so this + + + align:start position:0% +largest density gradient right so this +this is where the density gradient is + + align:start position:0% +this is where the density gradient is + + + align:start position:0% +this is where the density gradient is +very large so we expect outside of that + + align:start position:0% +very large so we expect outside of that + + + align:start position:0% +very large so we expect outside of that +region + + align:start position:0% +region + + + align:start position:0% +region +our intensity would be pretty much + + align:start position:0% +our intensity would be pretty much + + + align:start position:0% +our intensity would be pretty much +constant but inside that region we'd + + align:start position:0% +constant but inside that region we'd + + + align:start position:0% +constant but inside that region we'd +expect the intensity would drop to zero + + align:start position:0% +expect the intensity would drop to zero + + + align:start position:0% +expect the intensity would drop to zero +because we're blocking the rays which + + align:start position:0% +because we're blocking the rays which + + + align:start position:0% +because we're blocking the rays which +have a large deflection angle uh in One + + align:start position:0% +have a large deflection angle uh in One + + + align:start position:0% +have a large deflection angle uh in One +Direction upwards and the rays which + + align:start position:0% +Direction upwards and the rays which + + + align:start position:0% +Direction upwards and the rays which +have a large deflection angle in One + + align:start position:0% +have a large deflection angle in One + + + align:start position:0% +have a large deflection angle in One +Direction upwards corresponds to that + + align:start position:0% +Direction upwards corresponds to that + + + align:start position:0% +Direction upwards corresponds to that +specific density gradient + + align:start position:0% + + + + align:start position:0% + +there okay anyone want to have a go at + + align:start position:0% +there okay anyone want to have a go at + + + align:start position:0% +there okay anyone want to have a go at +telling me what happens with this + + align:start position:0% + + + + align:start position:0% + +one what's happening at the edges what's + + align:start position:0% +one what's happening at the edges what's + + + align:start position:0% +one what's happening at the edges what's +happening out in these regions here + + align:start position:0% +happening out in these regions here + + + align:start position:0% +happening out in these regions here +where the density gradients are small + + align:start position:0% + + + + align:start position:0% + +they're cropped out because they mostly + + align:start position:0% +they're cropped out because they mostly + + + align:start position:0% +they're cropped out because they mostly +go through the focal fcal spot right + + align:start position:0% +go through the focal fcal spot right + + + align:start position:0% +go through the focal fcal spot right +yeah so these are going to be zero right + + align:start position:0% +yeah so these are going to be zero right + + + align:start position:0% +yeah so these are going to be zero right +so zero zero is there any region where + + align:start position:0% +so zero zero is there any region where + + + align:start position:0% +so zero zero is there any region where +it's not + + align:start position:0% +it's not + + + align:start position:0% +it's not +zero uh I think it's not zero for the + + align:start position:0% +zero uh I think it's not zero for the + + + align:start position:0% +zero uh I think it's not zero for the +uh High gradient region that's lower in + + align:start position:0% +uh High gradient region that's lower in + + + align:start position:0% +uh High gradient region that's lower in +y it's deflected below so you think it's + + align:start position:0% +y it's deflected below so you think it's + + + align:start position:0% +y it's deflected below so you think it's +not zero for this region here yeah yes + + align:start position:0% +not zero for this region here yeah yes + + + align:start position:0% +not zero for this region here yeah yes +does anyone agree with sir or does + + align:start position:0% +does anyone agree with sir or does + + + align:start position:0% +does anyone agree with sir or does +anyone + + align:start position:0% + + + + align:start position:0% + +disagree I think that looks + + align:start position:0% + + + + align:start position:0% + +right okay so we're talking + + align:start position:0% +right okay so we're talking + + + align:start position:0% +right okay so we're talking +about this Ray here + + align:start position:0% + + + + align:start position:0% + +yeah so this Ray is indeed passing low + + align:start position:0% +yeah so this Ray is indeed passing low + + + align:start position:0% +yeah so this Ray is indeed passing low +down compared to the knife edge so we'd + + align:start position:0% +down compared to the knife edge so we'd + + + align:start position:0% +down compared to the knife edge so we'd +expect this to show some intensity here + + align:start position:0% +expect this to show some intensity here + + + align:start position:0% +expect this to show some intensity here +not for the upper one which passes + + align:start position:0% +not for the upper one which passes + + + align:start position:0% +not for the upper one which passes +higher + + align:start position:0% +higher + + + align:start position:0% +higher +up okay good we're getting that what + + align:start position:0% +up okay good we're getting that what + + + align:start position:0% +up okay good we're getting that what +about for the circular light + + align:start position:0% +about for the circular light + + + align:start position:0% +about for the circular light +field anyone want to tell me what the + + align:start position:0% +field anyone want to tell me what the + + + align:start position:0% +field anyone want to tell me what the +intensity looks like + + align:start position:0% + + + + align:start position:0% + +here you'd probably get Three Peaks so + + align:start position:0% +here you'd probably get Three Peaks so + + + align:start position:0% +here you'd probably get Three Peaks so +on the edges where the density isn't + + align:start position:0% +on the edges where the density isn't + + + align:start position:0% +on the edges where the density isn't +really where the density is just low and + + align:start position:0% +really where the density is just low and + + + align:start position:0% +really where the density is just low and +then right in the middle where the + + align:start position:0% +then right in the middle where the + + + align:start position:0% +then right in the middle where the +density is high but not really changing + + align:start position:0% +density is high but not really changing + + + align:start position:0% +density is high but not really changing +too much yeah so you say three Peaks I'm + + align:start position:0% +too much yeah so you say three Peaks I'm + + + align:start position:0% +too much yeah so you say three Peaks I'm +going to think about them as two notches + + align:start position:0% +going to think about them as two notches + + + align:start position:0% +going to think about them as two notches +but I agree with what you're saying so + + align:start position:0% +but I agree with what you're saying so + + + align:start position:0% +but I agree with what you're saying so +these notches here correspond to the + + align:start position:0% +these notches here correspond to the + + + align:start position:0% +these notches here correspond to the +points where the density gradient is + + align:start position:0% +points where the density gradient is + + + align:start position:0% +points where the density gradient is +largest here and so those those Rays got + + align:start position:0% +largest here and so those those Rays got + + + align:start position:0% +largest here and so those those Rays got +a big deflection angle they're being + + align:start position:0% +a big deflection angle they're being + + + align:start position:0% +a big deflection angle they're being +blocked out what + + align:start position:0% +blocked out what + + + align:start position:0% +blocked out what +about for the final one here darkfield + + align:start position:0% +about for the final one here darkfield + + + align:start position:0% +about for the final one here darkfield +circular + + align:start position:0% + + + + align:start position:0% + +aperture well there there your basically + + align:start position:0% +aperture well there there your basically + + + align:start position:0% +aperture well there there your basically +notching out all the uh un the minimally + + align:start position:0% +notching out all the uh un the minimally + + + align:start position:0% +notching out all the uh un the minimally +deflected arays so you lose the uh ones + + align:start position:0% +deflected arays so you lose the uh ones + + + align:start position:0% +deflected arays so you lose the uh ones +on the edges and + + align:start position:0% +on the edges and + + + align:start position:0% +on the edges and +Center yeah so we'd have something that + + align:start position:0% +Center yeah so we'd have something that + + + align:start position:0% +Center yeah so we'd have something that +looks like this right so we would just + + align:start position:0% +looks like this right so we would just + + + align:start position:0% +looks like this right so we would just +see light where there was a significant + + align:start position:0% +see light where there was a significant + + + align:start position:0% +see light where there was a significant +deflection + + align:start position:0% + + + + align:start position:0% + +angle okay um this may still seem a + + align:start position:0% +angle okay um this may still seem a + + + align:start position:0% +angle okay um this may still seem a +little bit abstract so we're going to + + align:start position:0% +little bit abstract so we're going to + + + align:start position:0% +little bit abstract so we're going to +try try one more thing and I hope that + + align:start position:0% +try try one more thing and I hope that + + + align:start position:0% +try try one more thing and I hope that +you don't hate me for spending so much + + align:start position:0% +you don't hate me for spending so much + + + align:start position:0% +you don't hate me for spending so much +time on Shin but I absolutely love it so + + align:start position:0% +time on Shin but I absolutely love it so + + + align:start position:0% +time on Shin but I absolutely love it so +um that's your loss um which is going to + + align:start position:0% +um that's your loss um which is going to + + + align:start position:0% +um that's your loss um which is going to +be a two-dimensional example here I'll + + align:start position:0% +be a two-dimensional example here I'll + + + align:start position:0% +be a two-dimensional example here I'll +just draw on this uh distribution + + align:start position:0% +just draw on this uh distribution + + + align:start position:0% +just draw on this uh distribution +function there we go density function + + align:start position:0% +function there we go density function + + + align:start position:0% +function there we go density function +down that last one just so you've got + + align:start position:0% + + + + align:start position:0% + +it so this actually goes back to + + align:start position:0% +it so this actually goes back to + + + align:start position:0% +it so this actually goes back to +a sketch that I did during the B dot + + align:start position:0% +a sketch that I did during the B dot + + + align:start position:0% +a sketch that I did during the B dot +lecture where we stuck a little B dot + + align:start position:0% +lecture where we stuck a little B dot + + + align:start position:0% +lecture where we stuck a little B dot +inside the plasma and we have plasma + + align:start position:0% +inside the plasma and we have plasma + + + align:start position:0% +inside the plasma and we have plasma +flow coming from left to right and + + align:start position:0% +flow coming from left to right and + + + align:start position:0% +flow coming from left to right and +because it collides with this we get + + align:start position:0% +because it collides with this we get + + + align:start position:0% +because it collides with this we get +some sort of bowel shock like + + align:start position:0% +some sort of bowel shock like + + + align:start position:0% +some sort of bowel shock like +this and we as we all know from our + + align:start position:0% +this and we as we all know from our + + + align:start position:0% +this and we as we all know from our +shock physics at the bow shock we have + + align:start position:0% +shock physics at the bow shock we have + + + align:start position:0% +shock physics at the bow shock we have +strong density + + align:start position:0% +strong density + + + align:start position:0% +strong density +gradients like + + align:start position:0% +gradients like + + + align:start position:0% +gradients like +this where the density jumps across the + + align:start position:0% +this where the density jumps across the + + + align:start position:0% +this where the density jumps across the +shock + + align:start position:0% +shock + + + align:start position:0% +shock +here so if we look at this system when + + align:start position:0% +here so if we look at this system when + + + align:start position:0% +here so if we look at this system when +we have our probing laser coming towards + + align:start position:0% +we have our probing laser coming towards + + + align:start position:0% +we have our probing laser coming towards +us right so our laser is looking towards + + align:start position:0% +us right so our laser is looking towards + + + align:start position:0% +us right so our laser is looking towards +us like this we are the camera what + + align:start position:0% +us like this we are the camera what + + + align:start position:0% +us like this we are the camera what +would we see about this bow shock what + + align:start position:0% +would we see about this bow shock what + + + align:start position:0% +would we see about this bow shock what +could we tell about it so maybe the + + align:start position:0% +could we tell about it so maybe the + + + align:start position:0% +could we tell about it so maybe the +first thing we could do is ask for like + + align:start position:0% +first thing we could do is ask for like + + + align:start position:0% +first thing we could do is ask for like +a light field circular aperture what do + + align:start position:0% +a light field circular aperture what do + + + align:start position:0% +a light field circular aperture what do +we think we would see + + align:start position:0% + + + + align:start position:0% + +here and if you're not quite sure at + + align:start position:0% +here and if you're not quite sure at + + + align:start position:0% +here and if you're not quite sure at +each of these places where I've drawn + + align:start position:0% +each of these places where I've drawn + + + align:start position:0% +each of these places where I've drawn +this little arrow you could say that the + + align:start position:0% + + + + align:start position:0% + +density maybe as a simple model looks + + align:start position:0% +density maybe as a simple model looks + + + align:start position:0% +density maybe as a simple model looks +like sort of hyperbolic e Tangy type + + align:start position:0% +like sort of hyperbolic e Tangy type + + + align:start position:0% +like sort of hyperbolic e Tangy type +thing like that it's got some region + + align:start position:0% +thing like that it's got some region + + + align:start position:0% +thing like that it's got some region +where the density is NE Z some region + + align:start position:0% +where the density is NE Z some region + + + align:start position:0% +where the density is NE Z some region +where the density is any1 and then some + + align:start position:0% +where the density is any1 and then some + + + align:start position:0% +where the density is any1 and then some +region where the density changes rapidly + + align:start position:0% +region where the density changes rapidly + + + align:start position:0% +region where the density changes rapidly +that's not true for a shock but yeah + + align:start position:0% +that's not true for a shock but yeah + + + align:start position:0% +that's not true for a shock but yeah +it's a model just to get us thinking + + align:start position:0% +it's a model just to get us thinking + + + align:start position:0% +it's a model just to get us thinking +about what this looks like so what would + + align:start position:0% +about what this looks like so what would + + + align:start position:0% +about what this looks like so what would +I see on my image I've got this expanded + + align:start position:0% +I see on my image I've got this expanded + + + align:start position:0% +I see on my image I've got this expanded +laser beam going through this shock and + + align:start position:0% +laser beam going through this shock and + + + align:start position:0% +laser beam going through this shock and +I've decided to use a circular light + + align:start position:0% +I've decided to use a circular light + + + align:start position:0% +I've decided to use a circular light +field + + align:start position:0% +field + + + align:start position:0% +field +stop I might be doing this backwards but + + align:start position:0% +stop I might be doing this backwards but + + + align:start position:0% +stop I might be doing this backwards but +from it looks like what we drew above + + align:start position:0% +from it looks like what we drew above + + + align:start position:0% +from it looks like what we drew above +that would mean that you're not getting + + align:start position:0% +that would mean that you're not getting + + + align:start position:0% +that would mean that you're not getting +your speep gradient sections so it + + align:start position:0% +your speep gradient sections so it + + + align:start position:0% +your speep gradient sections so it +should be dark where the bow shock is + + align:start position:0% +should be dark where the bow shock is + + + align:start position:0% +should be dark where the bow shock is +and yeah so you'd actually have an image + + align:start position:0% +and yeah so you'd actually have an image + + + align:start position:0% +and yeah so you'd actually have an image +yeah you'd have an image which you know + + align:start position:0% +yeah you'd have an image which you know + + + align:start position:0% +yeah you'd have an image which you know +if I was on a chalk board I could do + + align:start position:0% +if I was on a chalk board I could do + + + align:start position:0% +if I was on a chalk board I could do +with an eraser was actually quite hard + + align:start position:0% +with an eraser was actually quite hard + + + align:start position:0% +with an eraser was actually quite hard +here if you imagine this is filled with + + align:start position:0% +here if you imagine this is filled with + + + align:start position:0% +here if you imagine this is filled with +green laser beam beautiful nice laser + + align:start position:0% +green laser beam beautiful nice laser + + + align:start position:0% +green laser beam beautiful nice laser +beam image then you would have a region + + align:start position:0% +beam image then you would have a region + + + align:start position:0% +beam image then you would have a region +where no the Eraser is not very good if + + align:start position:0% +where no the Eraser is not very good if + + + align:start position:0% +where no the Eraser is not very good if +I could make the Eraser smaller that + + align:start position:0% +I could make the Eraser smaller that + + + align:start position:0% +I could make the Eraser smaller that +would work much better you would have a + + align:start position:0% +would work much better you would have a + + + align:start position:0% +would work much better you would have a +region where there was no light + + align:start position:0% +region where there was no light + + + align:start position:0% +region where there was no light +whatsoever and there was just darkness + + align:start position:0% +whatsoever and there was just darkness + + + align:start position:0% +whatsoever and there was just darkness +right so You' just have this dark region + + align:start position:0% +right so You' just have this dark region + + + align:start position:0% +right so You' just have this dark region +here corresponding to the bow shock and + + align:start position:0% +here corresponding to the bow shock and + + + align:start position:0% +here corresponding to the bow shock and +if you did this with a dark field + + align:start position:0% +if you did this with a dark field + + + align:start position:0% +if you did this with a dark field +circular aperture then you'd have the + + align:start position:0% +circular aperture then you'd have the + + + align:start position:0% +circular aperture then you'd have the +opposite you'd have complete darkness + + align:start position:0% +opposite you'd have complete darkness + + + align:start position:0% +opposite you'd have complete darkness +and you would just have a region where + + align:start position:0% +and you would just have a region where + + + align:start position:0% +and you would just have a region where +the bow shock shows up very nicely like + + align:start position:0% +the bow shock shows up very nicely like + + + align:start position:0% +the bow shock shows up very nicely like +this uh and so this is actually + + align:start position:0% +this uh and so this is actually + + + align:start position:0% +this uh and so this is actually +typically what we use for uh shock + + align:start position:0% +typically what we use for uh shock + + + align:start position:0% +typically what we use for uh shock +measurements is dark field circular + + align:start position:0% +measurements is dark field circular + + + align:start position:0% +measurements is dark field circular +aperture + + align:start position:0% + + + + align:start position:0% + +if you do happen to do something like a + + align:start position:0% +if you do happen to do something like a + + + align:start position:0% +if you do happen to do something like a +dark field with a knife + + align:start position:0% +dark field with a knife + + + align:start position:0% +dark field with a knife +edge and you put your knife + + align:start position:0% +edge and you put your knife + + + align:start position:0% +edge and you put your knife +edge like this so you were measuring + + align:start position:0% +edge like this so you were measuring + + + align:start position:0% +edge like this so you were measuring +density + + align:start position:0% +density + + + align:start position:0% +density +gradients that were in this + + align:start position:0% +gradients that were in this + + + align:start position:0% +gradients that were in this +direction you would end up seeing + + align:start position:0% +direction you would end up seeing + + + align:start position:0% +direction you would end up seeing +something a little bit like just one + + align:start position:0% +something a little bit like just one + + + align:start position:0% +something a little bit like just one +half of the bow shock like that so if + + align:start position:0% +half of the bow shock like that so if + + + align:start position:0% +half of the bow shock like that so if +your set your probe was was sitting here + + align:start position:0% +your set your probe was was sitting here + + + align:start position:0% +your set your probe was was sitting here +you would just see a little bit of the B + + align:start position:0% +you would just see a little bit of the B + + + align:start position:0% +you would just see a little bit of the B +shop you wouldn't see this section + + align:start position:0% +shop you wouldn't see this section + + + align:start position:0% +shop you wouldn't see this section +because the density gradients wouldn't + + align:start position:0% +because the density gradients wouldn't + + + align:start position:0% +because the density gradients wouldn't +be in the correct direction so you + + align:start position:0% +be in the correct direction so you + + + align:start position:0% +be in the correct direction so you +wouldn't be able to observe those but + + align:start position:0% +wouldn't be able to observe those but + + + align:start position:0% +wouldn't be able to observe those but +the knife edge might be a better choice + + align:start position:0% +the knife edge might be a better choice + + + align:start position:0% +the knife edge might be a better choice +for some Shock geometries if you're only + + align:start position:0% +for some Shock geometries if you're only + + + align:start position:0% +for some Shock geometries if you're only +interested in gradients in One Direction + + align:start position:0% +interested in gradients in One Direction + + + align:start position:0% +interested in gradients in One Direction +Aiden I see your + + align:start position:0% +Aiden I see your + + + align:start position:0% +Aiden I see your +hand oh yeah I'm curious how + + align:start position:0% +hand oh yeah I'm curious how + + + align:start position:0% +hand oh yeah I'm curious how +distinct + + align:start position:0% +distinct + + + align:start position:0% +distinct +um the the the actual image gradients + + align:start position:0% +um the the the actual image gradients + + + align:start position:0% +um the the the actual image gradients +would be um given that this is like a + + align:start position:0% +would be um given that this is like a + + + align:start position:0% +would be um given that this is like a +cylindrical phenomenon right the + + align:start position:0% +cylindrical phenomenon right the + + + align:start position:0% +cylindrical phenomenon right the +shock so I assume there's some some + + align:start position:0% +shock so I assume there's some some + + + align:start position:0% +shock so I assume there's some some +density gradients that they slowly + + align:start position:0% +density gradients that they slowly + + + align:start position:0% +density gradients that they slowly +become um parallel to your propagation + + align:start position:0% +become um parallel to your propagation + + + align:start position:0% +become um parallel to your propagation +direction as you rotate to the yeah so + + align:start position:0% +direction as you rotate to the yeah so + + + align:start position:0% +direction as you rotate to the yeah so +you won't see those density gradients + + align:start position:0% +you won't see those density gradients + + + align:start position:0% +you won't see those density gradients +but you will see the ones on the edges + + align:start position:0% +but you will see the ones on the edges + + + align:start position:0% +but you will see the ones on the edges +of the shock yeah it it depends on the + + align:start position:0% +of the shock yeah it it depends on the + + + align:start position:0% +of the shock yeah it it depends on the +exact shock morphology whether it's some + + align:start position:0% +exact shock morphology whether it's some + + + align:start position:0% +exact shock morphology whether it's some +extended like a bow shock that's + + align:start position:0% +extended like a bow shock that's + + + align:start position:0% +extended like a bow shock that's +extended like this or whether it's a bow + + align:start position:0% +extended like this or whether it's a bow + + + align:start position:0% +extended like this or whether it's a bow +shock sort of rotated like the tip of + + align:start position:0% +shock sort of rotated like the tip of + + + align:start position:0% +shock sort of rotated like the tip of +the a nose cone on an aircraft or + + align:start position:0% +the a nose cone on an aircraft or + + + align:start position:0% +the a nose cone on an aircraft or +something like that so it will it will + + align:start position:0% +something like that so it will it will + + + align:start position:0% +something like that so it will it will +make a difference but this is just to + + align:start position:0% +make a difference but this is just to + + + align:start position:0% +make a difference but this is just to +try and get a feel for what this looks + + align:start position:0% +try and get a feel for what this looks + + + align:start position:0% +try and get a feel for what this looks +like in terms of Imaging here I can send + + align:start position:0% +like in terms of Imaging here I can send + + + align:start position:0% +like in terms of Imaging here I can send +around some papers later which have some + + align:start position:0% +around some papers later which have some + + + align:start position:0% +around some papers later which have some +very nice images of schen of shock + + align:start position:0% +very nice images of schen of shock + + + align:start position:0% +very nice images of schen of shock +structures that show you know what sort + + align:start position:0% +structures that show you know what sort + + + align:start position:0% +structures that show you know what sort +of quality of data you can get out from + + align:start position:0% + + + + align:start position:0% + +this so any other questions on schen and + + align:start position:0% +this so any other questions on schen and + + + align:start position:0% +this so any other questions on schen and +will then just summarize exactly how to + + align:start position:0% +will then just summarize exactly how to + + + align:start position:0% +will then just summarize exactly how to +use it and when not to use it and things + + align:start position:0% +use it and when not to use it and things + + + align:start position:0% +use it and when not to use it and things +like that but if anyone has any + + align:start position:0% +like that but if anyone has any + + + align:start position:0% +like that but if anyone has any +questions on these sort of worked + + align:start position:0% +questions on these sort of worked + + + align:start position:0% +questions on these sort of worked +examples we've done please go ahead and + + align:start position:0% +examples we've done please go ahead and + + + align:start position:0% +examples we've done please go ahead and +Shout + + align:start position:0% + + + + align:start position:0% + +out + + align:start position:0% + + + + align:start position:0% + +okay so schen is good for + + align:start position:0% +okay so schen is good for + + + align:start position:0% +okay so schen is good for +visualizing density + + align:start position:0% +visualizing density + + + align:start position:0% +visualizing density +gradients right and in particular it's + + align:start position:0% +gradients right and in particular it's + + + align:start position:0% +gradients right and in particular it's +good for visualizing strong density + + align:start position:0% +good for visualizing strong density + + + align:start position:0% +good for visualizing strong density +gradients so in particular it's good at + + align:start position:0% +gradients so in particular it's good at + + + align:start position:0% +gradients so in particular it's good at +visualizing shocks so if you're looking + + align:start position:0% +visualizing shocks so if you're looking + + + align:start position:0% +visualizing shocks so if you're looking +at shocks in plasmas this is a nice + + align:start position:0% +at shocks in plasmas this is a nice + + + align:start position:0% +at shocks in plasmas this is a nice +Diagnostic and it's particularly nice + + align:start position:0% +Diagnostic and it's particularly nice + + + align:start position:0% +Diagnostic and it's particularly nice +because it's very simple to set up as I + + align:start position:0% +because it's very simple to set up as I + + + align:start position:0% +because it's very simple to set up as I +showed you it's just got at minimum a + + align:start position:0% +showed you it's just got at minimum a + + + align:start position:0% +showed you it's just got at minimum a +single optic you need to form a focal + + align:start position:0% +single optic you need to form a focal + + + align:start position:0% +single optic you need to form a focal +point so you need to have an optic you + + align:start position:0% +point so you need to have an optic you + + + align:start position:0% +point so you need to have an optic you +need a focal point and you need a stop + + align:start position:0% +need a focal point and you need a stop + + + align:start position:0% +need a focal point and you need a stop +so this is a very simple thing to set up + + align:start position:0% +so this is a very simple thing to set up + + + align:start position:0% +so this is a very simple thing to set up +you can do it very very quickly the + + align:start position:0% +you can do it very very quickly the + + + align:start position:0% +you can do it very very quickly the +trouble is although it's simple it's + + align:start position:0% +trouble is although it's simple it's + + + align:start position:0% +trouble is although it's simple it's +very difficult to be + + align:start position:0% + + + + align:start position:0% + +quantitative we can say there is some + + align:start position:0% +quantitative we can say there is some + + + align:start position:0% +quantitative we can say there is some +sort of density gradient there we think + + align:start position:0% +sort of density gradient there we think + + + align:start position:0% +sort of density gradient there we think +the density gradient has to be larger + + align:start position:0% +the density gradient has to be larger + + + align:start position:0% +the density gradient has to be larger +than some certain limiting value but + + align:start position:0% +than some certain limiting value but + + + align:start position:0% +than some certain limiting value but +other than that we can't really say much + + align:start position:0% +other than that we can't really say much + + + align:start position:0% +other than that we can't really say much +more than that so it's useful for seeing + + align:start position:0% +more than that so it's useful for seeing + + + align:start position:0% +more than that so it's useful for seeing +where shocks are and their morphology + + align:start position:0% +where shocks are and their morphology + + + align:start position:0% +where shocks are and their morphology +but it's not useful for measuring + + align:start position:0% +but it's not useful for measuring + + + align:start position:0% +but it's not useful for measuring +gradient of NE so we can't measure + + align:start position:0% + + + + align:start position:0% + +graad NE e we can + + align:start position:0% +graad NE e we can + + + align:start position:0% +graad NE e we can +measure shape and location of the + + align:start position:0% +measure shape and location of the + + + align:start position:0% +measure shape and location of the +density + + align:start position:0% + + + + align:start position:0% + +gradients now there are some ways where + + align:start position:0% +gradients now there are some ways where + + + align:start position:0% +gradients now there are some ways where +you can make this more quantitative so + + align:start position:0% +you can make this more quantitative so + + + align:start position:0% +you can make this more quantitative so +imagine you've got a little beam of + + align:start position:0% +imagine you've got a little beam of + + + align:start position:0% +imagine you've got a little beam of +light coming + + align:start position:0% +light coming + + + align:start position:0% +light coming +in like this this is going in this + + align:start position:0% +in like this this is going in this + + + align:start position:0% +in like this this is going in this +direction and you have a knife edge that + + align:start position:0% +direction and you have a knife edge that + + + align:start position:0% +direction and you have a knife edge that +looks like this + + align:start position:0% +looks like this + + + align:start position:0% +looks like this +that knife edge is going to be entirely + + align:start position:0% +that knife edge is going to be entirely + + + align:start position:0% +that knife edge is going to be entirely +blocking what's coming through we'll + + align:start position:0% +blocking what's coming through we'll + + + align:start position:0% +blocking what's coming through we'll +have zero light coming through but if we + + align:start position:0% +have zero light coming through but if we + + + align:start position:0% +have zero light coming through but if we +have a beam that comes through and it's + + align:start position:0% +have a beam that comes through and it's + + + align:start position:0% +have a beam that comes through and it's +lined up like + + align:start position:0% +lined up like + + + align:start position:0% +lined up like +this you can see that now about half the + + align:start position:0% +this you can see that now about half the + + + align:start position:0% +this you can see that now about half the +light is going to get through and if we + + align:start position:0% +light is going to get through and if we + + + align:start position:0% +light is going to get through and if we +have a beam come through that's lined up + + align:start position:0% +have a beam come through that's lined up + + + align:start position:0% +have a beam come through that's lined up +above the knife edge we'll have all of + + align:start position:0% +above the knife edge we'll have all of + + + align:start position:0% +above the knife edge we'll have all of +the light coming through and it turns + + align:start position:0% +the light coming through and it turns + + + align:start position:0% +the light coming through and it turns +out that if you have a large enough spot + + align:start position:0% +out that if you have a large enough spot + + + align:start position:0% +out that if you have a large enough spot +that you can actually see this partial + + align:start position:0% +that you can actually see this partial + + + align:start position:0% +that you can actually see this partial +obscuration + + align:start position:0% +obscuration + + + align:start position:0% +obscuration +of the focal point you end up in a + + align:start position:0% +of the focal point you end up in a + + + align:start position:0% +of the focal point you end up in a +regime where the intensity that you see + + align:start position:0% +regime where the intensity that you see + + + align:start position:0% +regime where the intensity that you see +on your detector I is in fact + + align:start position:0% +on your detector I is in fact + + + align:start position:0% +on your detector I is in fact +proportional directly to the gradient of + + align:start position:0% +proportional directly to the gradient of + + + align:start position:0% +proportional directly to the gradient of +the electron + + align:start position:0% +the electron + + + align:start position:0% +the electron +density I'm putting it in Brackets + + align:start position:0% +density I'm putting it in Brackets + + + align:start position:0% +density I'm putting it in Brackets +because you need a large + + align:start position:0% +because you need a large + + + align:start position:0% +because you need a large +uniform focal spot and I'll talk in a + + align:start position:0% +uniform focal spot and I'll talk in a + + + align:start position:0% +uniform focal spot and I'll talk in a +moment about why that's actually + + align:start position:0% +moment about why that's actually + + + align:start position:0% +moment about why that's actually +extremely difficult uh using a laser + + align:start position:0% +extremely difficult uh using a laser + + + align:start position:0% +extremely difficult uh using a laser +which is what we normally use + + align:start position:0% +which is what we normally use + + + align:start position:0% +which is what we normally use +here okay if you can't guarantee that + + align:start position:0% +here okay if you can't guarantee that + + + align:start position:0% +here okay if you can't guarantee that +you have a nice large uniform focal spot + + align:start position:0% +you have a nice large uniform focal spot + + + align:start position:0% +you have a nice large uniform focal spot +you could also use a a graded neutral + + align:start position:0% +you could also use a a graded neutral + + + align:start position:0% +you could also use a a graded neutral +density + + align:start position:0% +density + + + align:start position:0% +density +filter so a neutral density filter is + + align:start position:0% +filter so a neutral density filter is + + + align:start position:0% +filter so a neutral density filter is +sort of smoky glass that blocks light + + align:start position:0% +sort of smoky glass that blocks light + + + align:start position:0% +sort of smoky glass that blocks light +and you can change the amount of + + align:start position:0% +and you can change the amount of + + + align:start position:0% +and you can change the amount of +impurities in it to block more light so + + align:start position:0% +impurities in it to block more light so + + + align:start position:0% +impurities in it to block more light so +we could carefully fabricate for + + align:start position:0% +we could carefully fabricate for + + + align:start position:0% +we could carefully fabricate for +ourselves a neutral density + + align:start position:0% +ourselves a neutral density + + + align:start position:0% +ourselves a neutral density +filter that has a changing absorption so + + align:start position:0% +filter that has a changing absorption so + + + align:start position:0% +filter that has a changing absorption so +we can have a gradient and say we'll + + align:start position:0% +we can have a gradient and say we'll + + + align:start position:0% +we can have a gradient and say we'll +call the absorption Alpha here and then + + align:start position:0% +call the absorption Alpha here and then + + + align:start position:0% +call the absorption Alpha here and then +the idea is that different rays of + + align:start position:0% +the idea is that different rays of + + + align:start position:0% +the idea is that different rays of +Lights at different points of your stop + + align:start position:0% +Lights at different points of your stop + + + align:start position:0% +Lights at different points of your stop +will either come through + + align:start position:0% + + + + align:start position:0% + +uh not at all or very attenuated or they + + align:start position:0% +uh not at all or very attenuated or they + + + align:start position:0% +uh not at all or very attenuated or they +will come + + align:start position:0% +will come + + + align:start position:0% +will come +through partially + + align:start position:0% +through partially + + + align:start position:0% +through partially +attenuated or they will come + + align:start position:0% + + + + align:start position:0% + +through basally not attenuated at all + + align:start position:0% +through basally not attenuated at all + + + align:start position:0% +through basally not attenuated at all +and so if you have a really good graded + + align:start position:0% +and so if you have a really good graded + + + align:start position:0% +and so if you have a really good graded +neutral density filter you can again up + + align:start position:0% +neutral density filter you can again up + + + align:start position:0% +neutral density filter you can again up +in this regime where you actually get + + align:start position:0% +in this regime where you actually get + + + align:start position:0% +in this regime where you actually get +some + + align:start position:0% + + + + align:start position:0% + +sensitivity to uh the position of the + + align:start position:0% +sensitivity to uh the position of the + + + align:start position:0% +sensitivity to uh the position of the +beam and that can get you back into this + + align:start position:0% +beam and that can get you back into this + + + align:start position:0% +beam and that can get you back into this +nice regime up here where the intensity + + align:start position:0% +nice regime up here where the intensity + + + align:start position:0% +nice regime up here where the intensity +of your signal is actually proportional + + align:start position:0% +of your signal is actually proportional + + + align:start position:0% +of your signal is actually proportional +to the gradient of the electron density + + align:start position:0% +to the gradient of the electron density + + + align:start position:0% +to the gradient of the electron density +so that would be a very nice um place to + + align:start position:0% +so that would be a very nice um place to + + + align:start position:0% +so that would be a very nice um place to +be but this is hard to + + align:start position:0% +be but this is hard to + + + align:start position:0% +be but this is hard to +make and you still need a uniform beam + + align:start position:0% +make and you still need a uniform beam + + + align:start position:0% +make and you still need a uniform beam +to start with which is also hard to + + align:start position:0% +to start with which is also hard to + + + align:start position:0% +to start with which is also hard to +make so these techniques a lot of schen + + align:start position:0% +make so these techniques a lot of schen + + + align:start position:0% +make so these techniques a lot of schen +was actually developed um using light + + align:start position:0% +was actually developed um using light + + + align:start position:0% +was actually developed um using light +sources which are very different from + + align:start position:0% +sources which are very different from + + + align:start position:0% +sources which are very different from +the light sources that we have to end up + + align:start position:0% +the light sources that we have to end up + + + align:start position:0% +the light sources that we have to end up +using in um our experiments with plasmas + + align:start position:0% +using in um our experiments with plasmas + + + align:start position:0% +using in um our experiments with plasmas +uh and so you end up yes so I just + + align:start position:0% +uh and so you end up yes so I just + + + align:start position:0% +uh and so you end up yes so I just +looking at the beautiful pictures that + + align:start position:0% +looking at the beautiful pictures that + + + align:start position:0% +looking at the beautiful pictures that +uh Matthew put in the chat here these + + align:start position:0% +uh Matthew put in the chat here these + + + align:start position:0% +uh Matthew put in the chat here these +pictures here are absolutely glorious + + align:start position:0% +pictures here are absolutely glorious + + + align:start position:0% +pictures here are absolutely glorious +and you can see there's a huge amount of + + align:start position:0% +and you can see there's a huge amount of + + + align:start position:0% +and you can see there's a huge amount of +detail on them and this detail uh is due + + align:start position:0% +detail on them and this detail uh is due + + + align:start position:0% +detail on them and this detail uh is due +to the fact that actually I think for + + align:start position:0% +to the fact that actually I think for + + + align:start position:0% +to the fact that actually I think for +these ones they're using the Sun as the + + align:start position:0% +these ones they're using the Sun as the + + + align:start position:0% +these ones they're using the Sun as the +backlighter I may have forgotten this + + align:start position:0% +backlighter I may have forgotten this + + + align:start position:0% +backlighter I may have forgotten this +exactly but the light source is the sun + + align:start position:0% +exactly but the light source is the sun + + + align:start position:0% +exactly but the light source is the sun +and the sun is actually quite large it's + + align:start position:0% +and the sun is actually quite large it's + + + align:start position:0% +and the sun is actually quite large it's +an extended object you may have noticed + + align:start position:0% +an extended object you may have noticed + + + align:start position:0% +an extended object you may have noticed +in the sky um and this gives you really + + align:start position:0% +in the sky um and this gives you really + + + align:start position:0% +in the sky um and this gives you really +nice clearing Imaging but we don't tend + + align:start position:0% +nice clearing Imaging but we don't tend + + + align:start position:0% +nice clearing Imaging but we don't tend +to use nice large objects uh for our + + align:start position:0% +to use nice large objects uh for our + + + align:start position:0% +to use nice large objects uh for our +um our experiments with plasmas we tend + + align:start position:0% +um our experiments with plasmas we tend + + + align:start position:0% +um our experiments with plasmas we tend +to use things like lasers + + align:start position:0% + + + + align:start position:0% + +and lasers are not a good scharen + + align:start position:0% + + + + align:start position:0% + +source and if you want to read in more + + align:start position:0% +source and if you want to read in more + + + align:start position:0% +source and if you want to read in more +detail why lasers are actually a really + + align:start position:0% +detail why lasers are actually a really + + + align:start position:0% +detail why lasers are actually a really +bad idea you should go read the book + + align:start position:0% +bad idea you should go read the book + + + align:start position:0% +bad idea you should go read the book +that's listed in the bibliography by + + align:start position:0% +that's listed in the bibliography by + + + align:start position:0% +that's listed in the bibliography by +settles which is an absolutely cracking + + align:start position:0% +settles which is an absolutely cracking + + + align:start position:0% +settles which is an absolutely cracking +book has lots of lovely pictures like + + align:start position:0% +book has lots of lovely pictures like + + + align:start position:0% +book has lots of lovely pictures like +the ones which we just posted in the + + align:start position:0% +the ones which we just posted in the + + + align:start position:0% +the ones which we just posted in the +chat and also a very detailed + + align:start position:0% +chat and also a very detailed + + + align:start position:0% +chat and also a very detailed +description of this stuff um but can + + align:start position:0% +description of this stuff um but can + + + align:start position:0% +description of this stuff um but can +anyone tell me why if lasers aren't very + + align:start position:0% +anyone tell me why if lasers aren't very + + + align:start position:0% +anyone tell me why if lasers aren't very +good why do we end up up using lasers as + + align:start position:0% +good why do we end up up using lasers as + + + align:start position:0% +good why do we end up up using lasers as +the light source for schin Imaging in + + align:start position:0% +the light source for schin Imaging in + + + align:start position:0% +the light source for schin Imaging in +plasma + + align:start position:0% + + + + align:start position:0% + +physics what property of a laser is it + + align:start position:0% +physics what property of a laser is it + + + align:start position:0% +physics what property of a laser is it +that we particularly + + align:start position:0% + + + + align:start position:0% + +want monatic time is monocromatic so + + align:start position:0% +want monatic time is monocromatic so + + + align:start position:0% +want monatic time is monocromatic so +monochromatic is somewhat useful + + align:start position:0% +monochromatic is somewhat useful + + + align:start position:0% +monochromatic is somewhat useful +actually it turns out you can do really + + align:start position:0% +actually it turns out you can do really + + + align:start position:0% +actually it turns out you can do really +cool showing techniques with a broad + + align:start position:0% +cool showing techniques with a broad + + + align:start position:0% +cool showing techniques with a broad +band light source as well and filters + + align:start position:0% +band light source as well and filters + + + align:start position:0% +band light source as well and filters +because the different wavelengths will + + align:start position:0% +because the different wavelengths will + + + align:start position:0% +because the different wavelengths will +be deflected by different amounts and so + + align:start position:0% +be deflected by different amounts and so + + + align:start position:0% +be deflected by different amounts and so +if you have like multiple cameras with + + align:start position:0% +if you have like multiple cameras with + + + align:start position:0% +if you have like multiple cameras with +different filters you can really + + align:start position:0% +different filters you can really + + + align:start position:0% +different filters you can really +carefully reconstruct the reflection + + align:start position:0% +carefully reconstruct the reflection + + + align:start position:0% +carefully reconstruct the reflection +angles so monochromatic is a good guess + + align:start position:0% +angles so monochromatic is a good guess + + + align:start position:0% +angles so monochromatic is a good guess +but actually will be okay with Broadband + + align:start position:0% +but actually will be okay with Broadband + + + align:start position:0% +but actually will be okay with Broadband +uh what else when you think laser what + + align:start position:0% +uh what else when you think laser what + + + align:start position:0% +uh what else when you think laser what +do you + + align:start position:0% +do you + + + align:start position:0% +do you +think + + align:start position:0% +think + + + align:start position:0% +think +coherence coherence actually coherence + + align:start position:0% +coherence coherence actually coherence + + + align:start position:0% +coherence coherence actually coherence +isn't good for this and uh we've been + + align:start position:0% +isn't good for this and uh we've been + + + align:start position:0% +isn't good for this and uh we've been +using a ray picture and the coherence + + align:start position:0% +using a ray picture and the coherence + + + align:start position:0% +using a ray picture and the coherence +screws up our nice simple picture it's + + align:start position:0% +screws up our nice simple picture it's + + + align:start position:0% +screws up our nice simple picture it's +going to cause problem so we really want + + align:start position:0% +going to cause problem so we really want + + + align:start position:0% +going to cause problem so we really want +coherence for interferometry and we + + align:start position:0% +coherence for interferometry and we + + + align:start position:0% +coherence for interferometry and we +absolutely hate it for um schen and + + align:start position:0% +absolutely hate it for um schen and + + + align:start position:0% +absolutely hate it for um schen and +that's another that settles has in his + + align:start position:0% +that's another that settles has in his + + + align:start position:0% +that's another that settles has in his +book so coherence is a bad thing so I'm + + align:start position:0% +book so coherence is a bad thing so I'm + + + align:start position:0% +book so coherence is a bad thing so I'm +going to put + + align:start position:0% +going to put + + + align:start position:0% +going to put +coherence no we actually don't want it + + align:start position:0% +coherence no we actually don't want it + + + align:start position:0% +coherence no we actually don't want it +what else do we think about + + align:start position:0% + + + + align:start position:0% + +lasers well they tend to produce nice + + align:start position:0% +lasers well they tend to produce nice + + + align:start position:0% +lasers well they tend to produce nice +round spots so it's also easy to deflect + + align:start position:0% +round spots so it's also easy to deflect + + + align:start position:0% +round spots so it's also easy to deflect +them without a changing + + align:start position:0% +them without a changing + + + align:start position:0% +them without a changing +that nice beam yeah you can do that with + + align:start position:0% +that nice beam yeah you can do that with + + + align:start position:0% +that nice beam yeah you can do that with +other light sources but fine it is a + + align:start position:0% +other light sources but fine it is a + + + align:start position:0% +other light sources but fine it is a +nice + + align:start position:0% +nice + + + align:start position:0% +nice +beam anyone ever sha a laser pointer in + + align:start position:0% +beam anyone ever sha a laser pointer in + + + align:start position:0% +beam anyone ever sha a laser pointer in +their eye + + align:start position:0% +their eye + + + align:start position:0% +their eye +if not why + + align:start position:0% +if not why + + + align:start position:0% +if not why +not high energy density they're very + + align:start position:0% +not high energy density they're very + + + align:start position:0% +not high energy density they're very +bright should we put it that way okay so + + align:start position:0% +bright should we put it that way okay so + + + align:start position:0% +bright should we put it that way okay so +lasers are extremely bright why do we + + align:start position:0% +lasers are extremely bright why do we + + + align:start position:0% +lasers are extremely bright why do we +want a bright light source when we're + + align:start position:0% +want a bright light source when we're + + + align:start position:0% +want a bright light source when we're +dealing with + + align:start position:0% +dealing with + + + align:start position:0% +dealing with +plasmas the Plasma's glow yes so we need + + align:start position:0% +plasmas the Plasma's glow yes so we need + + + align:start position:0% +plasmas the Plasma's glow yes so we need +to + + align:start position:0% +to + + + align:start position:0% +to +overcome the + + align:start position:0% +overcome the + + + align:start position:0% +overcome the +plasma glow should we call it or should + + align:start position:0% +plasma glow should we call it or should + + + align:start position:0% +plasma glow should we call it or should +I say a mission here so when you're + + align:start position:0% +I say a mission here so when you're + + + align:start position:0% +I say a mission here so when you're +working with like jet planes flying + + align:start position:0% +working with like jet planes flying + + + align:start position:0% +working with like jet planes flying +around and you're taking um schan images + + align:start position:0% +around and you're taking um schan images + + + align:start position:0% +around and you're taking um schan images +of them using the Sun as your background + + align:start position:0% +of them using the Sun as your background + + + align:start position:0% +of them using the Sun as your background +you don't actually have to worry about + + align:start position:0% +you don't actually have to worry about + + + align:start position:0% +you don't actually have to worry about +the the the plasma or the the shock + + align:start position:0% +the the the plasma or the the shock + + + align:start position:0% +the the the plasma or the the shock +shocked air around the plane glowing and + + align:start position:0% +shocked air around the plane glowing and + + + align:start position:0% +shocked air around the plane glowing and +ruining your measurement was a plasma + + align:start position:0% +ruining your measurement was a plasma + + + align:start position:0% +ruining your measurement was a plasma +you really do it makes an awful lot of + + align:start position:0% +you really do it makes an awful lot of + + + align:start position:0% +you really do it makes an awful lot of +light so you need an incredibly bright + + align:start position:0% +light so you need an incredibly bright + + + align:start position:0% +light so you need an incredibly bright +light source and so despite the fact + + align:start position:0% +light source and so despite the fact + + + align:start position:0% +light source and so despite the fact +lasers are terrible for schin it's the + + align:start position:0% +lasers are terrible for schin it's the + + + align:start position:0% +lasers are terrible for schin it's the +brightest light source that we have + + align:start position:0% +brightest light source that we have + + + align:start position:0% +brightest light source that we have +available so we end up using that but + + align:start position:0% +available so we end up using that but + + + align:start position:0% +available so we end up using that but +the trouble with lasers is that they + + align:start position:0% +the trouble with lasers is that they + + + align:start position:0% +the trouble with lasers is that they +have a very small focal spot so they're + + align:start position:0% +have a very small focal spot so they're + + + align:start position:0% +have a very small focal spot so they're +in fact incredibly easy + + align:start position:0% +in fact incredibly easy + + + align:start position:0% +in fact incredibly easy +uh to focus down to a point and we don't + + align:start position:0% +uh to focus down to a point and we don't + + + align:start position:0% +uh to focus down to a point and we don't +want that we want a nice large focal + + align:start position:0% +want that we want a nice large focal + + + align:start position:0% +want that we want a nice large focal +spot and it's actually very difficult to + + align:start position:0% +spot and it's actually very difficult to + + + align:start position:0% +spot and it's actually very difficult to +get a laser to decco here enough to get + + align:start position:0% +get a laser to decco here enough to get + + + align:start position:0% +get a laser to decco here enough to get +a nice big focal spot but maybe there + + align:start position:0% +a nice big focal spot but maybe there + + + align:start position:0% +a nice big focal spot but maybe there +are some t techniques you can do and + + align:start position:0% +are some t techniques you can do and + + + align:start position:0% +are some t techniques you can do and +because we've got a small focal spot + + align:start position:0% +because we've got a small focal spot + + + align:start position:0% +because we've got a small focal spot +laser schen is effectively binary and + + align:start position:0% +laser schen is effectively binary and + + + align:start position:0% +laser schen is effectively binary and +I'll explain what I mean by that when I + + align:start position:0% +I'll explain what I mean by that when I + + + align:start position:0% +I'll explain what I mean by that when I +remember how to spell + + align:start position:0% + + + + align:start position:0% + +schen what I mean by that is the spot is + + align:start position:0% +schen what I mean by that is the spot is + + + align:start position:0% +schen what I mean by that is the spot is +so small the laser schin it is either + + align:start position:0% +so small the laser schin it is either + + + align:start position:0% +so small the laser schin it is either +completely blocked by the knife + + align:start position:0% +completely blocked by the knife + + + align:start position:0% +completely blocked by the knife +edge or it is completely visible + + align:start position:0% +edge or it is completely visible + + + align:start position:0% +edge or it is completely visible +unblocked by the knife edge and so when + + align:start position:0% +unblocked by the knife edge and so when + + + align:start position:0% +unblocked by the knife edge and so when +you do a laser SCH and image you get an + + align:start position:0% +you do a laser SCH and image you get an + + + align:start position:0% +you do a laser SCH and image you get an +image which is either dark or light zero + + align:start position:0% +image which is either dark or light zero + + + align:start position:0% +image which is either dark or light zero +or one no intensity or full + + align:start position:0% +or one no intensity or full + + + align:start position:0% +or one no intensity or full +intensity and so you don't get those + + align:start position:0% +intensity and so you don't get those + + + align:start position:0% +intensity and so you don't get those +nice images that we were just looking at + + align:start position:0% +nice images that we were just looking at + + + align:start position:0% +nice images that we were just looking at +that were linked and we also um don't + + align:start position:0% +that were linked and we also um don't + + + align:start position:0% +that were linked and we also um don't +have the ability to use the change in + + align:start position:0% +have the ability to use the change in + + + align:start position:0% +have the ability to use the change in +intensity to measure the gradients in + + align:start position:0% +intensity to measure the gradients in + + + align:start position:0% +intensity to measure the gradients in +the electron density because the + + align:start position:0% +the electron density because the + + + align:start position:0% +the electron density because the +intensity is either zero or one so uh we + + align:start position:0% +intensity is either zero or one so uh we + + + align:start position:0% +intensity is either zero or one so uh we +have very very limited dynamic range you + + align:start position:0% +have very very limited dynamic range you + + + align:start position:0% +have very very limited dynamic range you +can think about it that way we have no + + align:start position:0% +can think about it that way we have no + + + align:start position:0% +can think about it that way we have no +dynamic range we even though the density + + align:start position:0% +dynamic range we even though the density + + + align:start position:0% +dynamic range we even though the density +gradient is larger than a number or it's + + align:start position:0% +gradient is larger than a number or it's + + + align:start position:0% +gradient is larger than a number or it's +smaller than a number and that's it so + + align:start position:0% +smaller than a number and that's it so + + + align:start position:0% +smaller than a number and that's it so +it makes very good shock pictures but + + align:start position:0% +it makes very good shock pictures but + + + align:start position:0% +it makes very good shock pictures but +you can't do all the beautiful + + align:start position:0% +you can't do all the beautiful + + + align:start position:0% +you can't do all the beautiful +techniques that people use schen for in + + align:start position:0% +techniques that people use schen for in + + + align:start position:0% +techniques that people use schen for in +standard fluid dynamics where they have + + align:start position:0% +standard fluid dynamics where they have + + + align:start position:0% +standard fluid dynamics where they have +access to different sources so someone + + align:start position:0% +access to different sources so someone + + + align:start position:0% +access to different sources so someone +came up with a nice bright incoherent + + align:start position:0% +came up with a nice bright incoherent + + + align:start position:0% +came up with a nice bright incoherent +large area laser that we could use that + + align:start position:0% +large area laser that we could use that + + + align:start position:0% +large area laser that we could use that +would be absolutely great I have a few + + align:start position:0% +would be absolutely great I have a few + + + align:start position:0% +would be absolutely great I have a few +ideas along this direction um but I + + align:start position:0% +ideas along this direction um but I + + + align:start position:0% +ideas along this direction um but I +haven't had a chance to try them out yet + + align:start position:0% +haven't had a chance to try them out yet + + + align:start position:0% +haven't had a chance to try them out yet +um so yeah they they have some serious + + align:start position:0% +um so yeah they they have some serious + + + align:start position:0% +um so yeah they they have some serious +limitations so schin is a lovely + + align:start position:0% +limitations so schin is a lovely + + + align:start position:0% +limitations so schin is a lovely +technique for plasmas it's very limited + + align:start position:0% +technique for plasmas it's very limited + + + align:start position:0% +technique for plasmas it's very limited +it's obviously useful when you have + + align:start position:0% +it's obviously useful when you have + + + align:start position:0% +it's obviously useful when you have +shocks so you need to be having fast + + align:start position:0% +shocks so you need to be having fast + + + align:start position:0% +shocks so you need to be having fast +moving plasmas and so this is not really + + align:start position:0% +moving plasmas and so this is not really + + + align:start position:0% +moving plasmas and so this is not really +a technique that we normally use inside + + align:start position:0% +a technique that we normally use inside + + + align:start position:0% +a technique that we normally use inside +say a toac or magnetically confirmed + + align:start position:0% +say a toac or magnetically confirmed + + + align:start position:0% +say a toac or magnetically confirmed +device but it is very good when you have + + align:start position:0% +device but it is very good when you have + + + align:start position:0% +device but it is very good when you have +larger + + align:start position:0% + + + + align:start position:0% + +densities all right so any questions on + + align:start position:0% + + + + align:start position:0% + +this Nigel yeah so did we ever say how + + align:start position:0% +this Nigel yeah so did we ever say how + + + align:start position:0% +this Nigel yeah so did we ever say how +exactly the critical uh density was + + align:start position:0% +exactly the critical uh density was + + + align:start position:0% +exactly the critical uh density was +determined is that for a lecture oh do + + align:start position:0% +determined is that for a lecture oh do + + + align:start position:0% +determined is that for a lecture oh do +you mean like what is a numer what is an + + align:start position:0% +you mean like what is a numer what is an + + + align:start position:0% +you mean like what is a numer what is an +analytical result for the critical + + align:start position:0% +analytical result for the critical + + + align:start position:0% +analytical result for the critical +density yeah when when we had like one + + align:start position:0% +density yeah when when we had like one + + + align:start position:0% +density yeah when when we had like one +minus NE Over N critical like where that + + align:start position:0% +minus NE Over N critical like where that + + + align:start position:0% +minus NE Over N critical like where that +was over determined or is it just like + + align:start position:0% +was over determined or is it just like + + + align:start position:0% +was over determined or is it just like +kind of guess and check when oh no it's + + align:start position:0% +kind of guess and check when oh no it's + + + align:start position:0% +kind of guess and check when oh no it's +absolutely you can you can write it down + + align:start position:0% +absolutely you can you can write it down + + + align:start position:0% +absolutely you can you can write it down +it's a function and I I I neglected to + + align:start position:0% +it's a function and I I I neglected to + + + align:start position:0% +it's a function and I I I neglected to +write it down here and I'm not going to + + align:start position:0% +write it down here and I'm not going to + + + align:start position:0% +write it down here and I'm not going to +try and remember what it is but it is a + + align:start position:0% +try and remember what it is but it is a + + + align:start position:0% +try and remember what it is but it is a +function which has inside it the + + align:start position:0% +function which has inside it the + + + align:start position:0% +function which has inside it the +frequency of the laser light Epsilon not + + align:start position:0% +frequency of the laser light Epsilon not + + + align:start position:0% +frequency of the laser light Epsilon not +e and me and the no not the density + + align:start position:0% +e and me and the no not the density + + + align:start position:0% +e and me and the no not the density +definitely another density inside it so + + align:start position:0% +definitely another density inside it so + + + align:start position:0% +definitely another density inside it so +it is effectively comes from rearranging + + align:start position:0% +it is effectively comes from rearranging + + + align:start position:0% +it is effectively comes from rearranging +the plasma frequency here and you can + + align:start position:0% +the plasma frequency here and you can + + + align:start position:0% +the plasma frequency here and you can +find this in Hutchinson's book and I + + align:start position:0% +find this in Hutchinson's book and I + + + align:start position:0% +find this in Hutchinson's book and I +really should have written in my notes + + align:start position:0% +really should have written in my notes + + + align:start position:0% +really should have written in my notes +but I just didn't okay so um and I'm not + + align:start position:0% +but I just didn't okay so um and I'm not + + + align:start position:0% +but I just didn't okay so um and I'm not +going to try and you and look + + align:start position:0% +going to try and you and look + + + align:start position:0% +going to try and you and look +it up now so yeah the the critical + + align:start position:0% +it up now so yeah the the critical + + + align:start position:0% +it up now so yeah the the critical +density is a number that we can defin it + + align:start position:0% +density is a number that we can defin it + + + align:start position:0% +density is a number that we can defin it +is uniquely defined for every uh + + align:start position:0% +is uniquely defined for every uh + + + align:start position:0% +is uniquely defined for every uh +electromagnetic + + align:start position:0% +electromagnetic + + + align:start position:0% +electromagnetic +wavelength and that is the density which + + align:start position:0% +wavelength and that is the density which + + + align:start position:0% +wavelength and that is the density which +you cannot go above and if you're + + align:start position:0% +you cannot go above and if you're + + + align:start position:0% +you cannot go above and if you're +sensible you'll work well away from the + + align:start position:0% +sensible you'll work well away from the + + + align:start position:0% +sensible you'll work well away from the +critical density because if you get + + align:start position:0% +critical density because if you get + + + align:start position:0% +critical density because if you get +anywhere close to it it really screws up + + align:start position:0% +anywhere close to it it really screws up + + + align:start position:0% +anywhere close to it it really screws up +most of these calculations so most of + + align:start position:0% +most of these calculations so most of + + + align:start position:0% +most of these calculations so most of +the time we relying on this + + align:start position:0% +the time we relying on this + + + align:start position:0% +the time we relying on this +approximation that the density we're + + align:start position:0% +approximation that the density we're + + + align:start position:0% +approximation that the density we're +using is much less than the criticality + + align:start position:0% +using is much less than the criticality + + + align:start position:0% +using is much less than the criticality +and we'll come across that approximation + + align:start position:0% +and we'll come across that approximation + + + align:start position:0% +and we'll come across that approximation +very strongly when we deal with + + align:start position:0% +very strongly when we deal with + + + align:start position:0% +very strongly when we deal with +interferometry in a little + + align:start position:0% +interferometry in a little + + + align:start position:0% +interferometry in a little +bit but we did also use it already when + + align:start position:0% +bit but we did also use it already when + + + align:start position:0% +bit but we did also use it already when +we were ding the schan angle when we got + + align:start position:0% +we were ding the schan angle when we got + + + align:start position:0% +we were ding the schan angle when we got +to this point here we used this linear + + align:start position:0% +to this point here we used this linear + + + align:start position:0% +to this point here we used this linear +approximation where the density is much + + align:start position:0% +approximation where the density is much + + + align:start position:0% +approximation where the density is much +less than the critical + + align:start position:0% +less than the critical + + + align:start position:0% +less than the critical +density any other questions + + align:start position:0% + + + + align:start position:0% + +yeah so uh you were can you hear me I + + align:start position:0% +yeah so uh you were can you hear me I + + + align:start position:0% +yeah so uh you were can you hear me I +can hear you yeah Okay cool so um would + + align:start position:0% +can hear you yeah Okay cool so um would + + + align:start position:0% +can hear you yeah Okay cool so um would +it not be possible to use the quote + + align:start position:0% +it not be possible to use the quote + + + align:start position:0% +it not be possible to use the quote +unquote glow of the plasma itself to use + + align:start position:0% +unquote glow of the plasma itself to use + + + align:start position:0% +unquote glow of the plasma itself to use +lein in some other part of the plasma + + align:start position:0% +lein in some other part of the plasma + + + align:start position:0% +lein in some other part of the plasma +that isn't glowing itself or that it's + + align:start position:0% +that isn't glowing itself or that it's + + + align:start position:0% +that isn't glowing itself or that it's +glowing at some other + + align:start position:0% + + + + align:start position:0% + +frequency I thought about this I think + + align:start position:0% +frequency I thought about this I think + + + align:start position:0% +frequency I thought about this I think +it's a really cool idea um you + + align:start position:0% +it's a really cool idea um you + + + align:start position:0% +it's a really cool idea um you +definitely have to arrange your plasma + + align:start position:0% +definitely have to arrange your plasma + + + align:start position:0% +definitely have to arrange your plasma +so there's a bit that's glowing and a + + align:start position:0% +so there's a bit that's glowing and a + + + align:start position:0% +so there's a bit that's glowing and a +bit that isn't if the bit you want to + + align:start position:0% +bit that isn't if the bit you want to + + + align:start position:0% +bit that isn't if the bit you want to +measure is also glowing that's going to + + align:start position:0% +measure is also glowing that's going to + + + align:start position:0% +measure is also glowing that's going to +make things very very difficult um so + + align:start position:0% +make things very very difficult um so + + + align:start position:0% +make things very very difficult um so +yeah you could potentially have + + align:start position:0% +yeah you could potentially have + + + align:start position:0% +yeah you could potentially have +something like that like a ICF hotspot + + align:start position:0% +something like that like a ICF hotspot + + + align:start position:0% +something like that like a ICF hotspot +backlighting the whole Ram plasma uh + + align:start position:0% +backlighting the whole Ram plasma uh + + + align:start position:0% +backlighting the whole Ram plasma uh +that sort of thing could could work yeah + + align:start position:0% +that sort of thing could could work yeah + + + align:start position:0% +that sort of thing could could work yeah +but I don't know of anyone who's + + align:start position:0% +but I don't know of anyone who's + + + align:start position:0% +but I don't know of anyone who's +done okay thank + + align:start position:0% +done okay thank + + + align:start position:0% +done okay thank +you all right we're we're past the hour + + align:start position:0% +you all right we're we're past the hour + + + align:start position:0% +you all right we're we're past the hour +now so I think we'll leave it here I + + align:start position:0% +now so I think we'll leave it here I + + + align:start position:0% +now so I think we'll leave it here I +will be back in the classroom next + + align:start position:0% +will be back in the classroom next + + + align:start position:0% +will be back in the classroom next +Tuesday Tuesday I look forward to seeing + + align:start position:0% +Tuesday Tuesday I look forward to seeing + + + align:start position:0% +Tuesday Tuesday I look forward to seeing +all of you there and all the Columbia + + align:start position:0% +all of you there and all the Columbia + + + align:start position:0% +all of you there and all the Columbia +folks online and yeah enjoy your weekend + + align:start position:0% +folks online and yeah enjoy your weekend + + + align:start position:0% +folks online and yeah enjoy your weekend +and bye for now \ No newline at end of file diff --git a/wBnlmQR5Vhk.txt b/wBnlmQR5Vhk.txt new file mode 100644 index 0000000000000000000000000000000000000000..a64bf468d1b64fe4ebe644368a82b4194b0b5ff8 --- /dev/null +++ b/wBnlmQR5Vhk.txt @@ -0,0 +1,267 @@ +align:start position:0% + +this lecture consists of two parts that + + align:start position:0% +this lecture consists of two parts that + + + align:start position:0% +this lecture consists of two parts that +deal with two rather different topics in + + align:start position:0% +deal with two rather different topics in + + + align:start position:0% +deal with two rather different topics in +the first part we look into it an + + align:start position:0% +the first part we look into it an + + + align:start position:0% +the first part we look into it an +important special case of a derived + + align:start position:0% +important special case of a derived + + + align:start position:0% +important special case of a derived +distribution problem we start with two + + align:start position:0% +distribution problem we start with two + + + align:start position:0% +distribution problem we start with two +independent random variables with known + + align:start position:0% +independent random variables with known + + + align:start position:0% +independent random variables with known +distributions and wish to find the + + align:start position:0% +distributions and wish to find the + + + align:start position:0% +distributions and wish to find the +distribution of their sum we will see + + align:start position:0% +distribution of their sum we will see + + + align:start position:0% +distribution of their sum we will see +that for either the discrete or the + + align:start position:0% +that for either the discrete or the + + + align:start position:0% +that for either the discrete or the +continuous case there is a nice formula + + align:start position:0% +continuous case there is a nice formula + + + align:start position:0% +continuous case there is a nice formula +gives us the answer we will develop this + + align:start position:0% +gives us the answer we will develop this + + + align:start position:0% +gives us the answer we will develop this +formula and then we will talk a little + + align:start position:0% +formula and then we will talk a little + + + align:start position:0% +formula and then we will talk a little +bit about a graphical way of carrying + + align:start position:0% +bit about a graphical way of carrying + + + align:start position:0% +bit about a graphical way of carrying +out the calculations involved as we will + + align:start position:0% +out the calculations involved as we will + + + align:start position:0% +out the calculations involved as we will +discuss this formula also allows us to + + align:start position:0% +discuss this formula also allows us to + + + align:start position:0% +discuss this formula also allows us to +establish the very important fact that + + align:start position:0% +establish the very important fact that + + + align:start position:0% +establish the very important fact that +the sum of two independent normal random + + align:start position:0% +the sum of two independent normal random + + + align:start position:0% +the sum of two independent normal random +variables is normal in the second part + + align:start position:0% +variables is normal in the second part + + + align:start position:0% +variables is normal in the second part +who introduced the covariance of two + + align:start position:0% +who introduced the covariance of two + + + align:start position:0% +who introduced the covariance of two +random variables and the correlation + + align:start position:0% +random variables and the correlation + + + align:start position:0% +random variables and the correlation +coefficient these are certain quantities + + align:start position:0% +coefficient these are certain quantities + + + align:start position:0% +coefficient these are certain quantities +that allow us to quantify the degree to + + align:start position:0% +that allow us to quantify the degree to + + + align:start position:0% +that allow us to quantify the degree to +which two dependent random variables are + + align:start position:0% +which two dependent random variables are + + + align:start position:0% +which two dependent random variables are +related for example a high value of the + + align:start position:0% +related for example a high value of the + + + align:start position:0% +related for example a high value of the +correlation coefficient will indicate a + + align:start position:0% +correlation coefficient will indicate a + + + align:start position:0% +correlation coefficient will indicate a +strong relation between these random + + align:start position:0% +strong relation between these random + + + align:start position:0% +strong relation between these random +variables we will see the basic + + align:start position:0% +variables we will see the basic + + + align:start position:0% +variables we will see the basic +mathematical properties of these + + align:start position:0% +mathematical properties of these + + + align:start position:0% +mathematical properties of these +quantities and provide some + + align:start position:0% +quantities and provide some + + + align:start position:0% +quantities and provide some +interpretation later on in this class we + + align:start position:0% +interpretation later on in this class we + + + align:start position:0% +interpretation later on in this class we +will see that they play an important + + align:start position:0% +will see that they play an important + + + align:start position:0% +will see that they play an important +role in the problem of estimating one + + align:start position:0% +role in the problem of estimating one + + + align:start position:0% +role in the problem of estimating one +random variable given the value of + + align:start position:0% +random variable given the value of + + + align:start position:0% +random variable given the value of +another \ No newline at end of file diff --git a/wOHrNt9ScYs.txt b/wOHrNt9ScYs.txt new file mode 100644 index 0000000000000000000000000000000000000000..5a51e4473344eca358978e966b61de40a2cc5514 --- /dev/null +++ b/wOHrNt9ScYs.txt @@ -0,0 +1,7731 @@ +align:start position:0% + +The following content is provided under + + align:start position:0% +The following content is provided under + + + align:start position:0% +The following content is provided under +a Creative Common license. Your support + + align:start position:0% +a Creative Common license. Your support + + + align:start position:0% +a Creative Common license. Your support +will help MIT Open Courseware continue + + align:start position:0% +will help MIT Open Courseware continue + + + align:start position:0% +will help MIT Open Courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free. To make a donation + + align:start position:0% +resources for free. To make a donation + + + align:start position:0% +resources for free. To make a donation +or to view additional materials from + + align:start position:0% +or to view additional materials from + + + align:start position:0% +or to view additional materials from +hundreds of MIT courses, visit MIT Open + + align:start position:0% +hundreds of MIT courses, visit MIT Open + + + align:start position:0% +hundreds of MIT courses, visit MIT Open +Courseware at ocw.mmit.edu. + + align:start position:0% + + + + align:start position:0% + +Last time we left off with a question + + align:start position:0% +Last time we left off with a question + + + align:start position:0% +Last time we left off with a question +having to do with playing with blocks. + + align:start position:0% +having to do with playing with blocks. + + + align:start position:0% +having to do with playing with blocks. +And this is supposed to get give us a + + align:start position:0% +And this is supposed to get give us a + + + align:start position:0% +And this is supposed to get give us a +visceral feel for for something anyway + + align:start position:0% +visceral feel for for something anyway + + + align:start position:0% +visceral feel for for something anyway +having to do with series. And the + + align:start position:0% +having to do with series. And the + + + align:start position:0% +having to do with series. And the +question was whether I could stack these + + align:start position:0% +question was whether I could stack these + + + align:start position:0% +question was whether I could stack these +blocks build a stack so that I'm going + + align:start position:0% +blocks build a stack so that I'm going + + + align:start position:0% +blocks build a stack so that I'm going +to try it here up. I'm already off + + align:start position:0% +to try it here up. I'm already off + + + align:start position:0% +to try it here up. I'm already off +balance here. See the question is can I + + align:start position:0% +balance here. See the question is can I + + + align:start position:0% +balance here. See the question is can I +build this + + align:start position:0% +build this + + + align:start position:0% +build this +so that the um let's draw a picture of + + align:start position:0% +so that the um let's draw a picture of + + + align:start position:0% +so that the um let's draw a picture of +it + + align:start position:0% +it + + + align:start position:0% +it +so that the uh first block is like this. + + align:start position:0% +so that the uh first block is like this. + + + align:start position:0% +so that the uh first block is like this. +The next block is like this. And maybe + + align:start position:0% +The next block is like this. And maybe + + + align:start position:0% +The next block is like this. And maybe +the next block is like this. And notice + + align:start position:0% +the next block is like this. And notice + + + align:start position:0% +the next block is like this. And notice +there's no visible means of support for + + align:start position:0% +there's no visible means of support for + + + align:start position:0% +there's no visible means of support for +this block. It's completely to the left + + align:start position:0% +this block. It's completely to the left + + + align:start position:0% +this block. It's completely to the left +of the first block. + + align:start position:0% +of the first block. + + + align:start position:0% +of the first block. +And the question is uh will this fall + + align:start position:0% +And the question is uh will this fall + + + align:start position:0% +And the question is uh will this fall +down + + align:start position:0% +down + + + align:start position:0% +down +or at least + + align:start position:0% + + + + align:start position:0% + +or more precisely eventually we'll ask + + align:start position:0% +or more precisely eventually we'll ask + + + align:start position:0% +or more precisely eventually we'll ask +you know how far can we go? Now before + + align:start position:0% +you know how far can we go? Now before + + + align:start position:0% +you know how far can we go? Now before +you answer this question + + align:start position:0% +you answer this question + + + align:start position:0% +you answer this question +um the claim is that that this is a kind + + align:start position:0% +um the claim is that that this is a kind + + + align:start position:0% +um the claim is that that this is a kind +of a natural physical question which + + align:start position:0% +of a natural physical question which + + + align:start position:0% +of a natural physical question which +involves some important + + align:start position:0% +involves some important + + + align:start position:0% +involves some important +answer no matter whether the answer is + + align:start position:0% +answer no matter whether the answer is + + + align:start position:0% +answer no matter whether the answer is +you can do it or you can't. So this is + + align:start position:0% +you can do it or you can't. So this is + + + align:start position:0% +you can do it or you can't. So this is +the good kind of math question where no + + align:start position:0% +the good kind of math question where no + + + align:start position:0% +the good kind of math question where no +matter what the answer is if when you + + align:start position:0% +matter what the answer is if when you + + + align:start position:0% +matter what the answer is if when you +figure out the answer you're going to + + align:start position:0% +figure out the answer you're going to + + + align:start position:0% +figure out the answer you're going to +get something interesting out of it + + align:start position:0% +get something interesting out of it + + + align:start position:0% +get something interesting out of it +because there are two possibilities. + + align:start position:0% +because there are two possibilities. + + + align:start position:0% +because there are two possibilities. +Either there's a limit to how far to the + + align:start position:0% +Either there's a limit to how far to the + + + align:start position:0% +Either there's a limit to how far to the +left we can go in which case that's a + + align:start position:0% +left we can go in which case that's a + + + align:start position:0% +left we can go in which case that's a +very interesting number + + align:start position:0% +very interesting number + + + align:start position:0% +very interesting number +or else there is no limit you can go + + align:start position:0% +or else there is no limit you can go + + + align:start position:0% +or else there is no limit you can go +arbitrarily far and that's also + + align:start position:0% +arbitrarily far and that's also + + + align:start position:0% +arbitrarily far and that's also +interesting and curious and that's the + + align:start position:0% +interesting and curious and that's the + + + align:start position:0% +interesting and curious and that's the +difference between convergence and + + align:start position:0% +difference between convergence and + + + align:start position:0% +difference between convergence and +divergence + + align:start position:0% +divergence + + + align:start position:0% +divergence +the the thing that we were talking about + + align:start position:0% +the the thing that we were talking about + + + align:start position:0% +the the thing that we were talking about +up to now concerning series so my first + + align:start position:0% +up to now concerning series so my first + + + align:start position:0% +up to now concerning series so my first +question is do you think that I can get + + align:start position:0% +question is do you think that I can get + + + align:start position:0% +question is do you think that I can get +it uh get it so that this thing doesn't + + align:start position:0% +it uh get it so that this thing doesn't + + + align:start position:0% +it uh get it so that this thing doesn't +fall down with with well, you see, I + + align:start position:0% +fall down with with well, you see, I + + + align:start position:0% +fall down with with well, you see, I +have about eight blocks here or so. So, + + align:start position:0% +have about eight blocks here or so. So, + + + align:start position:0% +have about eight blocks here or so. So, +you you can vote now. How many in favor + + align:start position:0% +you you can vote now. How many in favor + + + align:start position:0% +you you can vote now. How many in favor +that I can that I can succeed in doing + + align:start position:0% +that I can that I can succeed in doing + + + align:start position:0% +that I can that I can succeed in doing +this sort of thing with maybe more than + + align:start position:0% +this sort of thing with maybe more than + + + align:start position:0% +this sort of thing with maybe more than +three blocks. How many in favor? All + + align:start position:0% +three blocks. How many in favor? All + + + align:start position:0% +three blocks. How many in favor? All +right, somebody's voting twice there. + + align:start position:0% +right, somebody's voting twice there. + + + align:start position:0% +right, somebody's voting twice there. +That's good. I like that. Um, how about + + align:start position:0% +That's good. I like that. Um, how about + + + align:start position:0% +That's good. I like that. Um, how about +how about opposed? + + align:start position:0% +how about opposed? + + + align:start position:0% +how about opposed? +Uh, so I I that was really close to a + + align:start position:0% +Uh, so I I that was really close to a + + + align:start position:0% +Uh, so I I that was really close to a +tie. All right. Uh, but I think that + + align:start position:0% +tie. All right. Uh, but I think that + + + align:start position:0% +tie. All right. Uh, but I think that +there was slightly more opposed. + + align:start position:0% +there was slightly more opposed. + + + align:start position:0% +there was slightly more opposed. +I don't know. You guys who were in the + + align:start position:0% +I don't know. You guys who were in the + + + align:start position:0% +I don't know. You guys who were in the +back maybe could tell. Anyway, it was it + + align:start position:0% +back maybe could tell. Anyway, it was it + + + align:start position:0% +back maybe could tell. Anyway, it was it +was pretty close. All right. So, now I'm + + align:start position:0% +was pretty close. All right. So, now I'm + + + align:start position:0% +was pretty close. All right. So, now I'm +going because this is a real life thing. + + align:start position:0% +going because this is a real life thing. + + + align:start position:0% +going because this is a real life thing. +I'm going to try to do it. All right. + + align:start position:0% +I'm going to try to do it. All right. + + + align:start position:0% +I'm going to try to do it. All right. +All right. So, now I'm going to tell you + + align:start position:0% +All right. So, now I'm going to tell you + + + align:start position:0% +All right. So, now I'm going to tell you +what the trick is. + + align:start position:0% +what the trick is. + + + align:start position:0% +what the trick is. +The trick is to do it backwards. When + + align:start position:0% +The trick is to do it backwards. When + + + align:start position:0% +The trick is to do it backwards. When +most people are playing with blocks, + + align:start position:0% +most people are playing with blocks, + + + align:start position:0% +most people are playing with blocks, +they decide to build it from the bottom + + align:start position:0% +they decide to build it from the bottom + + + align:start position:0% +they decide to build it from the bottom +up, right? But we're going to build it + + align:start position:0% +up, right? But we're going to build it + + + align:start position:0% +up, right? But we're going to build it +from the top down. From the top down. + + align:start position:0% +from the top down. From the top down. + + + align:start position:0% +from the top down. From the top down. +And that's going to make it possible for + + align:start position:0% +And that's going to make it possible for + + + align:start position:0% +And that's going to make it possible for +us to do the optimal thing at each + + align:start position:0% +us to do the optimal thing at each + + + align:start position:0% +us to do the optimal thing at each +stage. So when I build it from the top + + align:start position:0% +stage. So when I build it from the top + + + align:start position:0% +stage. So when I build it from the top +down, the best I can do is well, it'll + + align:start position:0% +down, the best I can do is well, it'll + + + align:start position:0% +down, the best I can do is well, it'll +fall off. I I need to have it less, you + + align:start position:0% +fall off. I I need to have it less, you + + + align:start position:0% +fall off. I I need to have it less, you +know, halfway across. That's the best I + + align:start position:0% +know, halfway across. That's the best I + + + align:start position:0% +know, halfway across. That's the best I +can do. So the top one I'm going to + + align:start position:0% +can do. So the top one I'm going to + + + align:start position:0% +can do. So the top one I'm going to +build like that. I'm going to take it as + + align:start position:0% +build like that. I'm going to take it as + + + align:start position:0% +build like that. I'm going to take it as +far to the left as I can. And then I'm + + align:start position:0% +far to the left as I can. And then I'm + + + align:start position:0% +far to the left as I can. And then I'm +gonna put the next one down as far to + + align:start position:0% +gonna put the next one down as far to + + + align:start position:0% +gonna put the next one down as far to +the left as I can. And then the next one + + align:start position:0% +the left as I can. And then the next one + + + align:start position:0% +the left as I can. And then the next one +as far to the left as I can. Oh, that + + align:start position:0% +as far to the left as I can. Oh, that + + + align:start position:0% +as far to the left as I can. Oh, that +was a little too far. And then I'm going + + align:start position:0% +was a little too far. And then I'm going + + + align:start position:0% +was a little too far. And then I'm going +to do the next one as far to the left as + + align:start position:0% +to do the next one as far to the left as + + + align:start position:0% +to do the next one as far to the left as +I can. And then I'm going to do the next + + align:start position:0% +I can. And then I'm going to do the next + + + align:start position:0% +I can. And then I'm going to do the next +one. Well, let's line it up first. + + align:start position:0% +one. Well, let's line it up first. + + + align:start position:0% +one. Well, let's line it up first. +As far to the left as I can. All right. + + align:start position:0% +As far to the left as I can. All right. + + + align:start position:0% +As far to the left as I can. All right. +And then the next one as far to the left + + align:start position:0% +And then the next one as far to the left + + + align:start position:0% +And then the next one as far to the left +as I can. All right. Now, those of you + + align:start position:0% +as I can. All right. Now, those of you + + + align:start position:0% +as I can. All right. Now, those of you +who are in this line can see. + + align:start position:0% +who are in this line can see. + + + align:start position:0% +who are in this line can see. +All right, I succeeded. All right, this + + align:start position:0% +All right, I succeeded. All right, this + + + align:start position:0% +All right, I succeeded. All right, this +is that's over the edge. All right, so + + align:start position:0% +is that's over the edge. All right, so + + + align:start position:0% +is that's over the edge. All right, so +it can be done. All right. + + align:start position:0% + + + + align:start position:0% + +All right. So now we know that we can + + align:start position:0% +All right. So now we know that we can + + + align:start position:0% +All right. So now we know that we can +get farther than you know we can we can + + align:start position:0% +get farther than you know we can we can + + + align:start position:0% +get farther than you know we can we can +we can make it overflow. So the question + + align:start position:0% +we can make it overflow. So the question + + + align:start position:0% +we can make it overflow. So the question +now is how far can I get? Okay. Do you + + align:start position:0% +now is how far can I get? Okay. Do you + + + align:start position:0% +now is how far can I get? Okay. Do you +think I can get to here? Can I Can I get + + align:start position:0% +think I can get to here? Can I Can I get + + + align:start position:0% +think I can get to here? Can I Can I get +to the end over here? So, how many how + + align:start position:0% +to the end over here? So, how many how + + + align:start position:0% +to the end over here? So, how many how +many people think I can get this this + + align:start position:0% +many people think I can get this this + + + align:start position:0% +many people think I can get this this +far over to here? How many people think + + align:start position:0% +far over to here? How many people think + + + align:start position:0% +far over to here? How many people think +I can get this far? Well, you know, + + align:start position:0% +I can get this far? Well, you know, + + + align:start position:0% +I can get this far? Well, you know, +remember I'm going to have to use more + + align:start position:0% +remember I'm going to have to use more + + + align:start position:0% +remember I'm going to have to use more +than just this one more block that I've + + align:start position:0% +than just this one more block that I've + + + align:start position:0% +than just this one more block that I've +got. I don't Right. Obviously, I'm + + align:start position:0% +got. I don't Right. Obviously, I'm + + + align:start position:0% +got. I don't Right. Obviously, I'm +thinking actually I do have some more + + align:start position:0% +thinking actually I do have some more + + + align:start position:0% +thinking actually I do have some more +blocks at home, but okay, we're not + + align:start position:0% +blocks at home, but okay, we're not + + + align:start position:0% +blocks at home, but okay, we're not +going to. But anyway, you think I can + + align:start position:0% +going to. But anyway, you think I can + + + align:start position:0% +going to. But anyway, you think I can +get over to here? How many people say + + align:start position:0% +get over to here? How many people say + + + align:start position:0% +get over to here? How many people say +yes? + + align:start position:0% +yes? + + + align:start position:0% +yes? +And how many people say no? + + align:start position:0% +And how many people say no? + + + align:start position:0% +And how many people say no? +More people said no than yes. All right. + + align:start position:0% +More people said no than yes. All right. + + + align:start position:0% +More people said no than yes. All right. +So maybe the the stopping place is some + + align:start position:0% +So maybe the the stopping place is some + + + align:start position:0% +So maybe the the stopping place is some +mysterious number in between here. All + + align:start position:0% +mysterious number in between here. All + + + align:start position:0% +mysterious number in between here. All +right. Well, okay. So now now we're + + align:start position:0% +right. Well, okay. So now now we're + + + align:start position:0% +right. Well, okay. So now now we're +going to do the arithmetic and we're + + align:start position:0% +going to do the arithmetic and we're + + + align:start position:0% +going to do the arithmetic and we're +going to figure out what happens with + + align:start position:0% +going to figure out what happens with + + + align:start position:0% +going to figure out what happens with +this with this problem in in Okay. Let's + + align:start position:0% +this with this problem in in Okay. Let's + + + align:start position:0% +this with this problem in in Okay. Let's +let's do it. + + align:start position:0% +let's do it. + + + align:start position:0% +let's do it. +All right. So now again the idea is the + + align:start position:0% +All right. So now again the idea is the + + + align:start position:0% +All right. So now again the idea is the +idea is we're going to start with the + + align:start position:0% +idea is we're going to start with the + + + align:start position:0% +idea is we're going to start with the +top + + align:start position:0% + + + + align:start position:0% + +the top block. + + align:start position:0% +the top block. + + + align:start position:0% +the top block. +We'll call that block number one. + + align:start position:0% + + + + align:start position:0% + +And then the farthest if you like to the + + align:start position:0% +And then the farthest if you like to the + + + align:start position:0% +And then the farthest if you like to the +right that you can put a block + + align:start position:0% +right that you can put a block + + + align:start position:0% +right that you can put a block +underneath it is exactly halfway. + + align:start position:0% +underneath it is exactly halfway. + + + align:start position:0% +underneath it is exactly halfway. +All right. Well, that's the best job I + + align:start position:0% +All right. Well, that's the best job I + + + align:start position:0% +All right. Well, that's the best job I +can do. Now, in order to make my units + + align:start position:0% +can do. Now, in order to make my units + + + align:start position:0% +can do. Now, in order to make my units +work out easily, I'm going to decide to + + align:start position:0% +work out easily, I'm going to decide to + + + align:start position:0% +work out easily, I'm going to decide to +call the length of the block two. All + + align:start position:0% +call the length of the block two. All + + + align:start position:0% +call the length of the block two. All +right? And that means if I start at + + align:start position:0% +right? And that means if I start at + + + align:start position:0% +right? And that means if I start at +location zero, then the first place + + align:start position:0% +location zero, then the first place + + + align:start position:0% +location zero, then the first place +where I am is supposed to be halfway + + align:start position:0% +where I am is supposed to be halfway + + + align:start position:0% +where I am is supposed to be halfway +and that will be one. + + align:start position:0% +and that will be one. + + + align:start position:0% +and that will be one. +Okay. So, so the first step in the + + align:start position:0% +Okay. So, so the first step in the + + + align:start position:0% +Okay. So, so the first step in the +process is one more to the right or if + + align:start position:0% +process is one more to the right or if + + + align:start position:0% +process is one more to the right or if +you like if I were building up, which is + + align:start position:0% +you like if I were building up, which is + + + align:start position:0% +you like if I were building up, which is +what you would actually have to do in + + align:start position:0% +what you would actually have to do in + + + align:start position:0% +what you would actually have to do in +real life, it would be one to the left. + + align:start position:0% +real life, it would be one to the left. + + + align:start position:0% +real life, it would be one to the left. +Okay. Now, the next one, now here's the + + align:start position:0% +Okay. Now, the next one, now here's the + + + align:start position:0% +Okay. Now, the next one, now here's the +the the the way that you start figuring + + align:start position:0% +the the the way that you start figuring + + + align:start position:0% +the the the way that you start figuring +out the arithmetic. The next one is is + + align:start position:0% +out the arithmetic. The next one is is + + + align:start position:0% +out the arithmetic. The next one is is +based on a physical principle which is + + align:start position:0% +based on a physical principle which is + + + align:start position:0% +based on a physical principle which is +that I the farthest I can stick this + + align:start position:0% +that I the farthest I can stick this + + + align:start position:0% +that I the farthest I can stick this +next block underneath is at what's + + align:start position:0% +next block underneath is at what's + + + align:start position:0% +next block underneath is at what's +called the center of mass of these two + + align:start position:0% +called the center of mass of these two + + + align:start position:0% +called the center of mass of these two +which is exactly halfway here. That is + + align:start position:0% +which is exactly halfway here. That is + + + align:start position:0% +which is exactly halfway here. That is +there's a quarter of this guy and a + + align:start position:0% +there's a quarter of this guy and a + + + align:start position:0% +there's a quarter of this guy and a +quarter of that guy balancing each + + align:start position:0% +quarter of that guy balancing each + + + align:start position:0% +quarter of that guy balancing each +other. All right. So that's as far as I + + align:start position:0% +other. All right. So that's as far as I + + + align:start position:0% +other. All right. So that's as far as I +can go. If I go farther than that it'll + + align:start position:0% +can go. If I go farther than that it'll + + + align:start position:0% +can go. If I go farther than that it'll +fall over. So that's the absolute + + align:start position:0% +fall over. So that's the absolute + + + align:start position:0% +fall over. So that's the absolute +farthest I can do. So the next block + + align:start position:0% +farthest I can do. So the next block + + + align:start position:0% +farthest I can do. So the next block +is going to be over here. And a quarter + + align:start position:0% +is going to be over here. And a quarter + + + align:start position:0% +is going to be over here. And a quarter +of two is a half. So this is three + + align:start position:0% +of two is a half. So this is three + + + align:start position:0% +of two is a half. So this is three +halves here. All right. So we went to + + align:start position:0% +halves here. All right. So we went to + + + align:start position:0% +halves here. All right. So we went to +one, we went to three halves here. And + + align:start position:0% +one, we went to three halves here. And + + + align:start position:0% +one, we went to three halves here. And +then I'm going to keep on going with + + align:start position:0% +then I'm going to keep on going with + + + align:start position:0% +then I'm going to keep on going with +this eventually. All right. So we're + + align:start position:0% +this eventually. All right. So we're + + + align:start position:0% +this eventually. All right. So we're +going to figure out what happens with + + align:start position:0% +going to figure out what happens with + + + align:start position:0% +going to figure out what happens with +this with this stack. + + align:start position:0% +this with this stack. + + + align:start position:0% +this with this stack. +Question. How do you know that this is + + align:start position:0% +Question. How do you know that this is + + + align:start position:0% +Question. How do you know that this is +the best way to optimize + + align:start position:0% +the best way to optimize + + + align:start position:0% +the best way to optimize +your The question is how do I know that + + align:start position:0% +your The question is how do I know that + + + align:start position:0% +your The question is how do I know that +this is the best way to optimize? Um I'm + + align:start position:0% +this is the best way to optimize? Um I'm + + + align:start position:0% +this is the best way to optimize? Um I'm +I can't answer that question, but I can + + align:start position:0% +I can't answer that question, but I can + + + align:start position:0% +I can't answer that question, but I can +tell you that it's the best way if I + + align:start position:0% +tell you that it's the best way if I + + + align:start position:0% +tell you that it's the best way if I +start with the top like this and the + + align:start position:0% +start with the top like this and the + + + align:start position:0% +start with the top like this and the +next one like this, right? Because I'm + + align:start position:0% +next one like this, right? Because I'm + + + align:start position:0% +next one like this, right? Because I'm +doing the farthest possible at each + + align:start position:0% +doing the farthest possible at each + + + align:start position:0% +doing the farthest possible at each +stage. That actually has a name in in + + align:start position:0% +stage. That actually has a name in in + + + align:start position:0% +stage. That actually has a name in in +computer science that's called the + + align:start position:0% +computer science that's called the + + + align:start position:0% +computer science that's called the +greedy algorithm. I'm trying to do the + + align:start position:0% +greedy algorithm. I'm trying to do the + + + align:start position:0% +greedy algorithm. I'm trying to do the +best possible at each stage. The greedy + + align:start position:0% +best possible at each stage. The greedy + + + align:start position:0% +best possible at each stage. The greedy +algorithm starting from the bottom is an + + align:start position:0% +algorithm starting from the bottom is an + + + align:start position:0% +algorithm starting from the bottom is an +extremely bad strategy because when you + + align:start position:0% +extremely bad strategy because when you + + + align:start position:0% +extremely bad strategy because when you +do that you stack it this way and it + + align:start position:0% +do that you stack it this way and it + + + align:start position:0% +do that you stack it this way and it +almost falls over and then the next time + + align:start position:0% +almost falls over and then the next time + + + align:start position:0% +almost falls over and then the next time +you can't do anything. So the greedy + + align:start position:0% +you can't do anything. So the greedy + + + align:start position:0% +you can't do anything. So the greedy +algorithm is terrible from the bottom + + align:start position:0% +algorithm is terrible from the bottom + + + align:start position:0% +algorithm is terrible from the bottom +but it turn this is the greedy algorithm + + align:start position:0% +but it turn this is the greedy algorithm + + + align:start position:0% +but it turn this is the greedy algorithm +starting from the top and it turns out + + align:start position:0% +starting from the top and it turns out + + + align:start position:0% +starting from the top and it turns out +to do much better than the greedy + + align:start position:0% +to do much better than the greedy + + + align:start position:0% +to do much better than the greedy +algorithm starting from the bottom. But + + align:start position:0% +algorithm starting from the bottom. But + + + align:start position:0% +algorithm starting from the bottom. But +of course I'm not addressing whether + + align:start position:0% +of course I'm not addressing whether + + + align:start position:0% +of course I'm not addressing whether +there might not be some other incredibly + + align:start position:0% +there might not be some other incredibly + + + align:start position:0% +there might not be some other incredibly +clever strategy where I wiggle around + + align:start position:0% +clever strategy where I wiggle around + + + align:start position:0% +clever strategy where I wiggle around +and make it go up. That's I'm I'm not an + + align:start position:0% +and make it go up. That's I'm I'm not an + + + align:start position:0% +and make it go up. That's I'm I'm not an +addressing that question. All right. It + + align:start position:0% +addressing that question. All right. It + + + align:start position:0% +addressing that question. All right. It +turns out this is the best you could do, + + align:start position:0% +turns out this is the best you could do, + + + align:start position:0% +turns out this is the best you could do, +but that's not not clear. All right. So + + align:start position:0% +but that's not not clear. All right. So + + + align:start position:0% +but that's not not clear. All right. So +now here here we have this thing and now + + align:start position:0% +now here here we have this thing and now + + + align:start position:0% +now here here we have this thing and now +I have to figure out what the arithmetic + + align:start position:0% +I have to figure out what the arithmetic + + + align:start position:0% +I have to figure out what the arithmetic +pattern is so that I can figure out what + + align:start position:0% +pattern is so that I can figure out what + + + align:start position:0% +pattern is so that I can figure out what +I was doing with those shapes. + + align:start position:0% + + + + align:start position:0% + +So let's let's uh uh figure out the the + + align:start position:0% +So let's let's uh uh figure out the the + + + align:start position:0% +So let's let's uh uh figure out the the +a thought experiment here. All right. + + align:start position:0% +a thought experiment here. All right. + + + align:start position:0% +a thought experiment here. All right. +Now, the thought experiment I want to + + align:start position:0% +Now, the thought experiment I want to + + + align:start position:0% +Now, the thought experiment I want to +imagine to you for you is you've got a + + align:start position:0% +imagine to you for you is you've got a + + + align:start position:0% +imagine to you for you is you've got a +stack of a bunch of blocks. + + align:start position:0% + + + + align:start position:0% + +And this is the first n blocks. + + align:start position:0% + + + + align:start position:0% + +All right. And now we're going to put + + align:start position:0% +All right. And now we're going to put + + + align:start position:0% +All right. And now we're going to put +one underneath it. + + align:start position:0% +one underneath it. + + + align:start position:0% +one underneath it. +And what we're going to figure out + + align:start position:0% +And what we're going to figure out + + + align:start position:0% +And what we're going to figure out +is the center of mass + + align:start position:0% +is the center of mass + + + align:start position:0% +is the center of mass +of those n blocks, which I'm going to + + align:start position:0% +of those n blocks, which I'm going to + + + align:start position:0% +of those n blocks, which I'm going to +call C subn. + + align:start position:0% +call C subn. + + + align:start position:0% +call C subn. +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +And that's the place where I'm going to + + align:start position:0% +And that's the place where I'm going to + + + align:start position:0% +And that's the place where I'm going to +put this very next block. I'll put it in + + align:start position:0% +put this very next block. I'll put it in + + + align:start position:0% +put this very next block. I'll put it in +a different color here. Here's the new + + align:start position:0% +a different color here. Here's the new + + + align:start position:0% +a different color here. Here's the new +the next block over. And the next block + + align:start position:0% +the next block over. And the next block + + + align:start position:0% +the next block over. And the next block +over is the n plus first block. + + align:start position:0% + + + + align:start position:0% + +And now I want you to think about what's + + align:start position:0% +And now I want you to think about what's + + + align:start position:0% +And now I want you to think about what's +going on here. If the center of mass of + + align:start position:0% +going on here. If the center of mass of + + + align:start position:0% +going on here. If the center of mass of +the first n blocks is this number, this + + align:start position:0% +the first n blocks is this number, this + + + align:start position:0% +the first n blocks is this number, this +new one, it's of length two and its + + align:start position:0% +new one, it's of length two and its + + + align:start position:0% +new one, it's of length two and its +center of mass is one further to the + + align:start position:0% +center of mass is one further to the + + + align:start position:0% +center of mass is one further to the +right than the center of mass that we + + align:start position:0% +right than the center of mass that we + + + align:start position:0% +right than the center of mass that we +had before. So in other words, I've + + align:start position:0% +had before. So in other words, I've + + + align:start position:0% +had before. So in other words, I've +added to this configuration of n blocks + + align:start position:0% +added to this configuration of n blocks + + + align:start position:0% +added to this configuration of n blocks +one more block which is shifted whose + + align:start position:0% +one more block which is shifted whose + + + align:start position:0% +one more block which is shifted whose +center of mass is not lined up with the + + align:start position:0% +center of mass is not lined up with the + + + align:start position:0% +center of mass is not lined up with the +center of mass of this but actually over + + align:start position:0% +center of mass of this but actually over + + + align:start position:0% +center of mass of this but actually over +farther to the to the right. Right? So + + align:start position:0% +farther to the to the right. Right? So + + + align:start position:0% +farther to the to the right. Right? So +the new center of mass of this new block + + align:start position:0% +the new center of mass of this new block + + + align:start position:0% +the new center of mass of this new block +or this is the extra piece of + + align:start position:0% +or this is the extra piece of + + + align:start position:0% +or this is the extra piece of +information that I want to observe is + + align:start position:0% +information that I want to observe is + + + align:start position:0% +information that I want to observe is +that this thing has a center of mass + + align:start position:0% +that this thing has a center of mass + + + align:start position:0% +that this thing has a center of mass +at + + align:start position:0% +at + + + align:start position:0% +at +CN + 1. It's one unit over because this + + align:start position:0% +CN + 1. It's one unit over because this + + + align:start position:0% +CN + 1. It's one unit over because this +total length is two. So right in the + + align:start position:0% +total length is two. So right in the + + + align:start position:0% +total length is two. So right in the +middle there is one over + + align:start position:0% +middle there is one over + + + align:start position:0% +middle there is one over +according to my units. + + align:start position:0% +according to my units. + + + align:start position:0% +according to my units. +All right. Now, this is going to make it + + align:start position:0% +All right. Now, this is going to make it + + + align:start position:0% +All right. Now, this is going to make it +possible for me to figure out what the + + align:start position:0% +possible for me to figure out what the + + + align:start position:0% +possible for me to figure out what the +new center of mass is. So, CN + one is + + align:start position:0% +new center of mass is. So, CN + one is + + + align:start position:0% +new center of mass is. So, CN + one is +the center of mass + + align:start position:0% + + + + align:start position:0% + +of n +1 blocks. + + align:start position:0% +of n +1 blocks. + + + align:start position:0% +of n +1 blocks. +Now, this is really only in the + + align:start position:0% +Now, this is really only in the + + + align:start position:0% +Now, this is really only in the +horizontal variable, right? I'm not I'm + + align:start position:0% +horizontal variable, right? I'm not I'm + + + align:start position:0% +horizontal variable, right? I'm not I'm +not keeping track of the center of mass. + + align:start position:0% +not keeping track of the center of mass. + + + align:start position:0% +not keeping track of the center of mass. +Actually, this thing is hard to build + + align:start position:0% +Actually, this thing is hard to build + + + align:start position:0% +Actually, this thing is hard to build +because the center of mass is also + + align:start position:0% +because the center of mass is also + + + align:start position:0% +because the center of mass is also +rising. It's getting higher and higher, + + align:start position:0% +rising. It's getting higher and higher, + + + align:start position:0% +rising. It's getting higher and higher, +but I'm only keeping track of its left + + align:start position:0% +but I'm only keeping track of its left + + + align:start position:0% +but I'm only keeping track of its left +right characteristic. So this is the + + align:start position:0% +right characteristic. So this is the + + + align:start position:0% +right characteristic. So this is the +xcoordinate of it. + + align:start position:0% + + + + align:start position:0% + +All right. So now here's the idea. + + align:start position:0% +All right. So now here's the idea. + + + align:start position:0% +All right. So now here's the idea. +I'm combining the white ones, the n + + align:start position:0% +I'm combining the white ones, the n + + + align:start position:0% +I'm combining the white ones, the n +blocks, with the pink one, which is the + + align:start position:0% +blocks, with the pink one, which is the + + + align:start position:0% +blocks, with the pink one, which is the +one on the bottom. And there are n of + + align:start position:0% +one on the bottom. And there are n of + + + align:start position:0% +one on the bottom. And there are n of +the white ones, and there's one of the + + align:start position:0% +the white ones, and there's one of the + + + align:start position:0% +the white ones, and there's one of the +pink one. And so in order to get the + + align:start position:0% +pink one. And so in order to get the + + + align:start position:0% +pink one. And so in order to get the +center of mass of the hole, I have to + + align:start position:0% +center of mass of the hole, I have to + + + align:start position:0% +center of mass of the hole, I have to +take the weighted average of the two. + + align:start position:0% +take the weighted average of the two. + + + align:start position:0% +take the weighted average of the two. +That's n * cn plus 1 times the uh center + + align:start position:0% +That's n * cn plus 1 times the uh center + + + align:start position:0% +That's n * cn plus 1 times the uh center +of mass of the pink one, which is cn + + + align:start position:0% +of mass of the pink one, which is cn + + + + align:start position:0% +of mass of the pink one, which is cn + +one. + + align:start position:0% +one. + + + align:start position:0% +one. +And then I have to divide if it's + + align:start position:0% +And then I have to divide if it's + + + align:start position:0% +And then I have to divide if it's +weighted average is a total of n plus1 + + align:start position:0% +weighted average is a total of n plus1 + + + align:start position:0% +weighted average is a total of n plus1 +blocks by n +1. + + align:start position:0% +blocks by n +1. + + + align:start position:0% +blocks by n +1. +Now this is going to give me the new + + align:start position:0% +Now this is going to give me the new + + + align:start position:0% +Now this is going to give me the new +center of mass of my configuration at + + align:start position:0% +center of mass of my configuration at + + + align:start position:0% +center of mass of my configuration at +the n plus1 first stage. + + align:start position:0% + + + + align:start position:0% + +And now I can just do the arithmetic and + + align:start position:0% +And now I can just do the arithmetic and + + + align:start position:0% +And now I can just do the arithmetic and +figure out what this is. + + align:start position:0% +figure out what this is. + + + align:start position:0% +figure out what this is. +And the two CN combine I get n +1 * cn + + + align:start position:0% +And the two CN combine I get n +1 * cn + + + + align:start position:0% +And the two CN combine I get n +1 * cn + +1 / n +1. + + align:start position:0% +1 / n +1. + + + align:start position:0% +1 / n +1. +And if I combine these two things and do + + align:start position:0% +And if I combine these two things and do + + + align:start position:0% +And if I combine these two things and do +the cancellation, that gives me this + + align:start position:0% +the cancellation, that gives me this + + + align:start position:0% +the cancellation, that gives me this +recurrence formula. CN + one is equal to + + align:start position:0% +recurrence formula. CN + one is equal to + + + align:start position:0% +recurrence formula. CN + one is equal to +CN plus there's a little extra. These + + align:start position:0% +CN plus there's a little extra. These + + + align:start position:0% +CN plus there's a little extra. These +two cancel. That gives me the CN. But + + align:start position:0% +two cancel. That gives me the CN. But + + + align:start position:0% +two cancel. That gives me the CN. But +then I also have 1 over 1 uh n + one. + + align:start position:0% + + + + align:start position:0% + +That's how much gain I can get in the + + align:start position:0% +That's how much gain I can get in the + + + align:start position:0% +That's how much gain I can get in the +center of mass by adding one more block. + + align:start position:0% +center of mass by adding one more block. + + + align:start position:0% +center of mass by adding one more block. +That's how much I can shift things over + + align:start position:0% +That's how much I can shift things over + + + align:start position:0% +That's how much I can shift things over +uh depending on how we're thinking of + + align:start position:0% +uh depending on how we're thinking of + + + align:start position:0% +uh depending on how we're thinking of +things to the to the left or the right + + align:start position:0% +things to the to the left or the right + + + align:start position:0% +things to the to the left or the right +depending on which direction we're + + align:start position:0% +depending on which direction we're + + + align:start position:0% +depending on which direction we're +building them. + + align:start position:0% +building them. + + + align:start position:0% +building them. +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +All right. So now I'm going to work out + + align:start position:0% +All right. So now I'm going to work out + + + align:start position:0% +All right. So now I'm going to work out +the formulas. First of all, C1 that was + + align:start position:0% +the formulas. First of all, C1 that was + + + align:start position:0% +the formulas. First of all, C1 that was +the center of the first block. I put its + + align:start position:0% +the center of the first block. I put its + + + align:start position:0% +the center of the first block. I put its +left end at zero. The center of the + + align:start position:0% +left end at zero. The center of the + + + align:start position:0% +left end at zero. The center of the +first block is at one. That means that + + align:start position:0% +first block is at one. That means that + + + align:start position:0% +first block is at one. That means that +C1 is one. + + align:start position:0% +C1 is one. + + + align:start position:0% +C1 is one. +Okay. C2 + + align:start position:0% +Okay. C2 + + + align:start position:0% +Okay. C2 +according to this formula and actually I + + align:start position:0% +according to this formula and actually I + + + align:start position:0% +according to this formula and actually I +worked it out. We'll check it in a + + align:start position:0% +worked it out. We'll check it in a + + + align:start position:0% +worked it out. We'll check it in a +second. C2 is C1 + 1 /2, right? That's + + align:start position:0% +second. C2 is C1 + 1 /2, right? That's + + + align:start position:0% +second. C2 is C1 + 1 /2, right? That's +the case N= 1. So this is 1 plus a half. + + align:start position:0% +the case N= 1. So this is 1 plus a half. + + + align:start position:0% +the case N= 1. So this is 1 plus a half. +That's what we already did. + + align:start position:0% +That's what we already did. + + + align:start position:0% +That's what we already did. +That's the three halves number. And now + + align:start position:0% +That's the three halves number. And now + + + align:start position:0% +That's the three halves number. And now +the next one is C2 + a3. + + align:start position:0% +the next one is C2 + a3. + + + align:start position:0% +the next one is C2 + a3. +That's the formula again. And so that + + align:start position:0% +That's the formula again. And so that + + + align:start position:0% +That's the formula again. And so that +comes out to be 1 + a half plus a third. + + align:start position:0% +comes out to be 1 + a half plus a third. + + + align:start position:0% +comes out to be 1 + a half plus a third. +And now you can see what the pattern is. + + align:start position:0% +And now you can see what the pattern is. + + + align:start position:0% +And now you can see what the pattern is. +CN, + + align:start position:0% +CN, + + + align:start position:0% +CN, +if you just keep on going here, CN is + + align:start position:0% +if you just keep on going here, CN is + + + align:start position:0% +if you just keep on going here, CN is +going to be 1 + a half plus a third plus + + align:start position:0% +going to be 1 + a half plus a third plus + + + align:start position:0% +going to be 1 + a half plus a third plus +a 4th + + align:start position:0% +a 4th + + + align:start position:0% +a 4th +plus 1 / n. + + align:start position:0% + + + + align:start position:0% + +So now I would like you to vote again. + + align:start position:0% +So now I would like you to vote again. + + + align:start position:0% +So now I would like you to vote again. +Do you think I can now that we have the + + align:start position:0% +Do you think I can now that we have the + + + align:start position:0% +Do you think I can now that we have the +formula, do you think I can get over to + + align:start position:0% +formula, do you think I can get over to + + + align:start position:0% +formula, do you think I can get over to +here? + + align:start position:0% +here? + + + align:start position:0% +here? +How many people think I can get over to + + align:start position:0% +How many people think I can get over to + + + align:start position:0% +How many people think I can get over to +here? + + align:start position:0% + + + + align:start position:0% + +How many people think I can't get over + + align:start position:0% +How many people think I can't get over + + + align:start position:0% +How many people think I can't get over +to here? Oh, there's still a lot of + + align:start position:0% +to here? Oh, there's still a lot of + + + align:start position:0% +to here? Oh, there's still a lot of +people who do. So it's still almost + + align:start position:0% +people who do. So it's still almost + + + align:start position:0% +people who do. So it's still almost +50/50. That's that's amazing. Well, so + + align:start position:0% +50/50. That's that's amazing. Well, so + + + align:start position:0% +50/50. That's that's amazing. Well, so +we'll address that in a in a in a few + + align:start position:0% +we'll address that in a in a in a few + + + align:start position:0% +we'll address that in a in a in a few +minutes. So now let me tell you what's + + align:start position:0% +minutes. So now let me tell you what's + + + align:start position:0% +minutes. So now let me tell you what's +going on. + + align:start position:0% +going on. + + + align:start position:0% +going on. +This CN of course is the same as what we + + align:start position:0% +This CN of course is the same as what we + + + align:start position:0% +This CN of course is the same as what we +called last time Sn. + + align:start position:0% +called last time Sn. + + + align:start position:0% +called last time Sn. +And remember that we actually estimated + + align:start position:0% +And remember that we actually estimated + + + align:start position:0% +And remember that we actually estimated +the size of this guy. This is related to + + align:start position:0% +the size of this guy. This is related to + + + align:start position:0% +the size of this guy. This is related to +what's called the harmonic series. And + + align:start position:0% +what's called the harmonic series. And + + + align:start position:0% +what's called the harmonic series. And +what we showed was that log n is less + + align:start position:0% +what we showed was that log n is less + + + align:start position:0% +what we showed was that log n is less +than sn which is less than s n + one. + + align:start position:0% +than sn which is less than s n + one. + + + align:start position:0% +than sn which is less than s n + one. +All right. + + align:start position:0% +All right. + + + align:start position:0% +All right. +Now I'm going to call your attention to + + align:start position:0% +Now I'm going to call your attention to + + + align:start position:0% +Now I'm going to call your attention to +the + + align:start position:0% +the + + + align:start position:0% +the +red part which is the divergence part of + + align:start position:0% +red part which is the divergence part of + + + align:start position:0% +red part which is the divergence part of +this estimate which is this one for the + + align:start position:0% +this estimate which is this one for the + + + align:start position:0% +this estimate which is this one for the +time being. All right, which is saying + + align:start position:0% +time being. All right, which is saying + + + align:start position:0% +time being. All right, which is saying +that this thing is growing. And what + + align:start position:0% +that this thing is growing. And what + + + align:start position:0% +that this thing is growing. And what +this is saying is that as n goes to + + align:start position:0% +this is saying is that as n goes to + + + align:start position:0% +this is saying is that as n goes to +infinity, + + align:start position:0% + + + + align:start position:0% + +log n goes to infinity. + + align:start position:0% + + + + align:start position:0% + +So that means + + align:start position:0% +So that means + + + align:start position:0% +So that means +that um sn goes to infinity + + align:start position:0% + + + + align:start position:0% + +because of this inequality here. It's + + align:start position:0% +because of this inequality here. It's + + + align:start position:0% +because of this inequality here. It's +bigger than log n. And so if n is big + + align:start position:0% +bigger than log n. And so if n is big + + + align:start position:0% +bigger than log n. And so if n is big +enough, we can get as far as we like. + + align:start position:0% +enough, we can get as far as we like. + + + align:start position:0% +enough, we can get as far as we like. +All right. + + align:start position:0% +All right. + + + align:start position:0% +All right. +So I can get to here. And at least half + + align:start position:0% +So I can get to here. And at least half + + + align:start position:0% +So I can get to here. And at least half +of you, at least the ones who voted. + + align:start position:0% +of you, at least the ones who voted. + + + align:start position:0% +of you, at least the ones who voted. +That was I don't know. We have a quorum + + align:start position:0% +That was I don't know. We have a quorum + + + align:start position:0% +That was I don't know. We have a quorum +here, but I'm not sure. We certainly + + align:start position:0% +here, but I'm not sure. We certainly + + + align:start position:0% +here, but I'm not sure. We certainly +didn't have a majority on either side. + + align:start position:0% +didn't have a majority on either side. + + + align:start position:0% +didn't have a majority on either side. +Anyway, + + align:start position:0% +Anyway, + + + align:start position:0% +Anyway, +this thing does go to infinity. So in + + align:start position:0% +this thing does go to infinity. So in + + + align:start position:0% +this thing does go to infinity. So in +principle, if I had enough blocks, I + + align:start position:0% +principle, if I had enough blocks, I + + + align:start position:0% +principle, if I had enough blocks, I +could get it over to get it over to + + align:start position:0% +could get it over to get it over to + + + align:start position:0% +could get it over to get it over to +here. + + align:start position:0% +here. + + + align:start position:0% +here. +All right. And that's the meaning of + + align:start position:0% +All right. And that's the meaning of + + + align:start position:0% +All right. And that's the meaning of +divergence in this case. + + align:start position:0% + + + + align:start position:0% + +On the other hand, + + align:start position:0% +On the other hand, + + + align:start position:0% +On the other hand, +I want to discuss with you and the + + align:start position:0% +I want to discuss with you and the + + + align:start position:0% +I want to discuss with you and the +reason why I use this example is I want + + align:start position:0% +reason why I use this example is I want + + + align:start position:0% +reason why I use this example is I want +to discuss with you also what's going on + + align:start position:0% +to discuss with you also what's going on + + + align:start position:0% +to discuss with you also what's going on +with this other inequality here and what + + align:start position:0% +with this other inequality here and what + + + align:start position:0% +with this other inequality here and what +its significance is + + align:start position:0% +its significance is + + + align:start position:0% +its significance is +which is that it's going to take us a + + align:start position:0% +which is that it's going to take us a + + + align:start position:0% +which is that it's going to take us a +lot of numbers n a lot of blocks to get + + align:start position:0% +lot of numbers n a lot of blocks to get + + + align:start position:0% +lot of numbers n a lot of blocks to get +up to a certain level. In other words, I + + align:start position:0% +up to a certain level. In other words, I + + + align:start position:0% +up to a certain level. In other words, I +can't do it with just eight blocks or + + align:start position:0% +can't do it with just eight blocks or + + + align:start position:0% +can't do it with just eight blocks or +nine blocks. In order to get over here, + + align:start position:0% +nine blocks. In order to get over here, + + + align:start position:0% +nine blocks. In order to get over here, +I'd have to use quite a few of them. + + align:start position:0% +I'd have to use quite a few of them. + + + align:start position:0% +I'd have to use quite a few of them. +So, let's just see how many it is. + + align:start position:0% +So, let's just see how many it is. + + + align:start position:0% +So, let's just see how many it is. +So, I I worked this out carefully + + align:start position:0% +So, I I worked this out carefully + + + align:start position:0% +So, I I worked this out carefully +and let's see what I got. + + align:start position:0% +and let's see what I got. + + + align:start position:0% +and let's see what I got. +So to get + + align:start position:0% +So to get + + + align:start position:0% +So to get +across + + align:start position:0% +across + + + align:start position:0% +across +the lab tables. + + align:start position:0% + + + + align:start position:0% + +All right. Um this this distance here I + + align:start position:0% +All right. Um this this distance here I + + + align:start position:0% +All right. Um this this distance here I +I already did this secretly. Uh but I I + + align:start position:0% +I already did this secretly. Uh but I I + + + align:start position:0% +I already did this secretly. Uh but I I +don't actually even have enough of these + + align:start position:0% +don't actually even have enough of these + + + align:start position:0% +don't actually even have enough of these +to show you, but well 1 2 3 4 5 6 and a + + align:start position:0% +to show you, but well 1 2 3 4 5 6 and a + + + align:start position:0% +to show you, but well 1 2 3 4 5 6 and a +half. I guess that's enough. So it's six + + align:start position:0% +half. I guess that's enough. So it's six + + + align:start position:0% +half. I guess that's enough. So it's six +and a half. So it's it's two lab tables + + align:start position:0% +and a half. So it's it's two lab tables + + + align:start position:0% +and a half. So it's it's two lab tables +is 13 of these blocks. All right. So + + align:start position:0% +is 13 of these blocks. All right. So + + + align:start position:0% +is 13 of these blocks. All right. So +there are 13 blocks + + align:start position:0% + + + + align:start position:0% + +which is equal to 26 units. + + align:start position:0% +which is equal to 26 units. + + + align:start position:0% +which is equal to 26 units. +Okay. That's how far to get across I + + align:start position:0% +Okay. That's how far to get across I + + + align:start position:0% +Okay. That's how far to get across I +need. And uh the first one is already + + align:start position:0% +need. And uh the first one is already + + + align:start position:0% +need. And uh the first one is already +two. So it's really 26 minus 2 which is + + align:start position:0% +two. So it's really 26 minus 2 which is + + + align:start position:0% +two. So it's really 26 minus 2 which is +24 which is that's what I need. Okay. + + align:start position:0% +24 which is that's what I need. Okay. + + + align:start position:0% +24 which is that's what I need. Okay. +So I need log n to be equal to 24 + + align:start position:0% + + + + align:start position:0% + +roughly speaking in order to get that + + align:start position:0% +roughly speaking in order to get that + + + align:start position:0% +roughly speaking in order to get that +far. So let's just see how how how big + + align:start position:0% +far. So let's just see how how how big + + + align:start position:0% +far. So let's just see how how how big +that is. All right, + + align:start position:0% +that is. All right, + + + align:start position:0% +that is. All right, +I think I worked this out. + + align:start position:0% + + + + align:start position:0% + +So let's see that means that n is equal + + align:start position:0% +So let's see that means that n is equal + + + align:start position:0% +So let's see that means that n is equal +to e to the 24th. + + align:start position:0% +to e to the 24th. + + + align:start position:0% +to e to the 24th. +And if you if you realize that these + + align:start position:0% +And if you if you realize that these + + + align:start position:0% +And if you if you realize that these +blocks + + align:start position:0% +blocks + + + align:start position:0% +blocks +are 3 cm high. + + align:start position:0% + + + + align:start position:0% + +Okay, let's see how many how many that + + align:start position:0% +Okay, let's see how many how many that + + + align:start position:0% +Okay, let's see how many how many that +we would need here. That's kind of a + + align:start position:0% +we would need here. That's kind of a + + + align:start position:0% +we would need here. That's kind of a +lot. Let's see. It's 3 cm + + align:start position:0% +lot. Let's see. It's 3 cm + + + align:start position:0% +lot. Let's see. It's 3 cm +time um e 24th which is about 8 * 10 the + + align:start position:0% +time um e 24th which is about 8 * 10 the + + + align:start position:0% +time um e 24th which is about 8 * 10 the +8 m. + + align:start position:0% +8 m. + + + align:start position:0% +8 m. +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +And that is twice the distance to the + + align:start position:0% +And that is twice the distance to the + + + align:start position:0% +And that is twice the distance to the +moon. + + align:start position:0% + + + + align:start position:0% + +All right. So, um, so, okay, I could do + + align:start position:0% +All right. So, um, so, okay, I could do + + + align:start position:0% +All right. So, um, so, okay, I could do +it maybe, + + align:start position:0% +it maybe, + + + align:start position:0% +it maybe, +but, uh, I would need a lot of blocks, + + align:start position:0% +but, uh, I would need a lot of blocks, + + + align:start position:0% +but, uh, I would need a lot of blocks, +right? It's not not very plausible here. + + align:start position:0% +right? It's not not very plausible here. + + + align:start position:0% +right? It's not not very plausible here. +All right, so those of you who voted + + align:start position:0% +All right, so those of you who voted + + + align:start position:0% +All right, so those of you who voted +against this were actually sort of half + + align:start position:0% +against this were actually sort of half + + + align:start position:0% +against this were actually sort of half +right. And in fact, if you wanted to get + + align:start position:0% +right. And in fact, if you wanted to get + + + align:start position:0% +right. And in fact, if you wanted to get +it to the wall over there, which is over + + align:start position:0% +it to the wall over there, which is over + + + align:start position:0% +it to the wall over there, which is over +30 pe feet, the height would be about + + align:start position:0% +30 pe feet, the height would be about + + + align:start position:0% +30 pe feet, the height would be about +the um diameter of the observable + + align:start position:0% +the um diameter of the observable + + + align:start position:0% +the um diameter of the observable +universe. That's kind of kind of a long + + align:start position:0% +universe. That's kind of kind of a long + + + align:start position:0% +universe. That's kind of kind of a long +way. Um there there's there's one other + + align:start position:0% +way. Um there there's there's one other + + + align:start position:0% +way. Um there there's there's one other +thing that that that I wanted to to + + align:start position:0% +thing that that that I wanted to to + + + align:start position:0% +thing that that that I wanted to to +point out to you about this shape here, + + align:start position:0% +point out to you about this shape here, + + + align:start position:0% +point out to you about this shape here, +which is that if you if you lean to the + + align:start position:0% +which is that if you if you lean to the + + + align:start position:0% +which is that if you if you lean to the +left, right, if you if you put your head + + align:start position:0% +left, right, if you if you put your head + + + align:start position:0% +left, right, if you if you put your head +like this, of course, you have to be on + + align:start position:0% +like this, of course, you have to be on + + + align:start position:0% +like this, of course, you have to be on +your side to look at it. This this curve + + align:start position:0% +your side to look at it. This this curve + + + align:start position:0% +your side to look at it. This this curve +um is is the um + + align:start position:0% +um is is the um + + + align:start position:0% +um is is the um +is the shape of a of a of a logarithmic + + align:start position:0% +is the shape of a of a of a logarithmic + + + align:start position:0% +is the shape of a of a of a logarithmic +curve. So in other words, if you think + + align:start position:0% +curve. So in other words, if you think + + + align:start position:0% +curve. So in other words, if you think +of this, the the vertical is the x- axis + + align:start position:0% +of this, the the vertical is the x- axis + + + align:start position:0% +of this, the the vertical is the x- axis +and the the the horizontal that way is + + align:start position:0% +and the the the horizontal that way is + + + align:start position:0% +and the the the horizontal that way is +the vertical is the up direction. Then + + align:start position:0% +the vertical is the up direction. Then + + + align:start position:0% +the vertical is the up direction. Then +this thing is growing very very very + + align:start position:0% +this thing is growing very very very + + + align:start position:0% +this thing is growing very very very +very slowly. If you send the x-axis all + + align:start position:0% +very slowly. If you send the x-axis all + + + align:start position:0% +very slowly. If you send the x-axis all +the way up to the moon, you're still the + + align:start position:0% +the way up to the moon, you're still the + + + align:start position:0% +the way up to the moon, you're still the +graph still hasn't gotten across the lab + + align:start position:0% +graph still hasn't gotten across the lab + + + align:start position:0% +graph still hasn't gotten across the lab +tables here. It's only partway there. If + + align:start position:0% +tables here. It's only partway there. If + + + align:start position:0% +tables here. It's only partway there. If +you go twice the distance to the moon up + + align:start position:0% +you go twice the distance to the moon up + + + align:start position:0% +you go twice the distance to the moon up +that way, it's gotten finally to that + + align:start position:0% +that way, it's gotten finally to that + + + align:start position:0% +that way, it's gotten finally to that +end. All right. So that's how slowly the + + align:start position:0% +end. All right. So that's how slowly the + + + align:start position:0% +end. All right. So that's how slowly the +logarithm grows. It grows very very + + align:start position:0% +logarithm grows. It grows very very + + + align:start position:0% +logarithm grows. It grows very very +slowly. And if you look at it another + + align:start position:0% +slowly. And if you look at it another + + + align:start position:0% +slowly. And if you look at it another +way, if you stand on your head, you can + + align:start position:0% +way, if you stand on your head, you can + + + align:start position:0% +way, if you stand on your head, you can +see a uh an exponential curve and see so + + align:start position:0% +see a uh an exponential curve and see so + + + align:start position:0% +see a uh an exponential curve and see so +you get some sense as to the growth + + align:start position:0% +you get some sense as to the growth + + + align:start position:0% +you get some sense as to the growth +properties of these functions. And + + align:start position:0% +properties of these functions. And + + + align:start position:0% +properties of these functions. And +fortunately, + + align:start position:0% +fortunately, + + + align:start position:0% +fortunately, +these are protecting us from uh from all + + align:start position:0% +these are protecting us from uh from all + + + align:start position:0% +these are protecting us from uh from all +kinds of stuff that would happen if + + align:start position:0% +kinds of stuff that would happen if + + + align:start position:0% +kinds of stuff that would happen if +there weren't exponentially small tails + + align:start position:0% +there weren't exponentially small tails + + + align:start position:0% +there weren't exponentially small tails +in the world. like you know I could walk + + align:start position:0% +in the world. like you know I could walk + + + align:start position:0% +in the world. like you know I could walk +through this wall which I wouldn't like + + align:start position:0% +through this wall which I wouldn't like + + + align:start position:0% +through this wall which I wouldn't like +doing. + + align:start position:0% +doing. + + + align:start position:0% +doing. +Um okay + + align:start position:0% +Um okay + + + align:start position:0% +Um okay +now so this is our last example and and + + align:start position:0% +now so this is our last example and and + + + align:start position:0% +now so this is our last example and and +the important number we for + + align:start position:0% +the important number we for + + + align:start position:0% +the important number we for +unfortunately we didn't discover another + + align:start position:0% +unfortunately we didn't discover another + + + align:start position:0% +unfortunately we didn't discover another +important number there wasn't an amazing + + align:start position:0% +important number there wasn't an amazing + + + align:start position:0% +important number there wasn't an amazing +number place where this stopped all we + + align:start position:0% +number place where this stopped all we + + + align:start position:0% +number place where this stopped all we +discovered again is is some property of + + align:start position:0% +discovered again is is some property of + + + align:start position:0% +discovered again is is some property of +infinity so infinity is still a nice + + align:start position:0% +infinity so infinity is still a nice + + + align:start position:0% +infinity so infinity is still a nice +number and the theme here is just that + + align:start position:0% +number and the theme here is just that + + + align:start position:0% +number and the theme here is just that +infinity isn't just one thing it's a has + + align:start position:0% +infinity isn't just one thing it's a has + + + align:start position:0% +infinity isn't just one thing it's a has +a character which is a rate of growth + + align:start position:0% +a character which is a rate of growth + + + align:start position:0% +a character which is a rate of growth +and you shouldn't just think of there + + align:start position:0% +and you shouldn't just think of there + + + align:start position:0% +and you shouldn't just think of there +being one order of infinity. There are + + align:start position:0% +being one order of infinity. There are + + + align:start position:0% +being one order of infinity. There are +lots of different orders and some of + + align:start position:0% +lots of different orders and some of + + + align:start position:0% +lots of different orders and some of +them have different meaning from others. + + align:start position:0% +them have different meaning from others. + + + align:start position:0% +them have different meaning from others. +All right, so that's the the theme I + + align:start position:0% +All right, so that's the the theme I + + + align:start position:0% +All right, so that's the the theme I +wanted to to do and just have an a + + align:start position:0% +wanted to to do and just have an a + + + align:start position:0% +wanted to to do and just have an a +visceral example of infinity. Now, we're + + align:start position:0% +visceral example of infinity. Now, we're + + + align:start position:0% +visceral example of infinity. Now, we're +going to move on now to some other kinds + + align:start position:0% +going to move on now to some other kinds + + + align:start position:0% +going to move on now to some other kinds +of uh techniques and this is going to be + + align:start position:0% +of uh techniques and this is going to be + + + align:start position:0% +of uh techniques and this is going to be +our last subject. + + align:start position:0% +our last subject. + + + align:start position:0% +our last subject. +What we're going to talk about is what + + align:start position:0% +What we're going to talk about is what + + + align:start position:0% +What we're going to talk about is what +are known as power series. + + align:start position:0% +are known as power series. + + + align:start position:0% +are known as power series. +Now, we've already seen our first power + + align:start position:0% +Now, we've already seen our first power + + + align:start position:0% +Now, we've already seen our first power +series, + + align:start position:0% + + + + align:start position:0% + +and I'm going to remind you of that. + + align:start position:0% + + + + align:start position:0% + +So, here we are with power series. + + align:start position:0% +So, here we are with power series. + + + align:start position:0% +So, here we are with power series. +Our + + align:start position:0% + + + + align:start position:0% + +first series was was this one. + + align:start position:0% + + + + align:start position:0% + +And we mentioned last time that it was + + align:start position:0% +And we mentioned last time that it was + + + align:start position:0% +And we mentioned last time that it was +equal to 1 over 1 - x + + align:start position:0% +equal to 1 over 1 - x + + + align:start position:0% +equal to 1 over 1 - x +for x less than one. + + align:start position:0% + + + + align:start position:0% + +This one is known as the geometric + + align:start position:0% +This one is known as the geometric + + + align:start position:0% +This one is known as the geometric +series. I didn't use the letter x last + + align:start position:0% +series. I didn't use the letter x last + + + align:start position:0% +series. I didn't use the letter x last +time. I used the letter a. But this is + + align:start position:0% +time. I used the letter a. But this is + + + align:start position:0% +time. I used the letter a. But this is +known as a geometric series. + + align:start position:0% + + + + align:start position:0% + +Now I'm going to show you one reason why + + align:start position:0% +Now I'm going to show you one reason why + + + align:start position:0% +Now I'm going to show you one reason why +this is true, + + align:start position:0% +this is true, + + + align:start position:0% +this is true, +why the formula holds, + + align:start position:0% +why the formula holds, + + + align:start position:0% +why the formula holds, +and it's just the kind of manipulation + + align:start position:0% +and it's just the kind of manipulation + + + align:start position:0% +and it's just the kind of manipulation +that uh was done when these things were + + align:start position:0% +that uh was done when these things were + + + align:start position:0% +that uh was done when these things were +first introduced. Uh and here's the the + + align:start position:0% +first introduced. Uh and here's the the + + + align:start position:0% +first introduced. Uh and here's the the +idea of a of a proof. + + align:start position:0% +idea of a of a proof. + + + align:start position:0% +idea of a of a proof. +So suppose + + align:start position:0% + + + + align:start position:0% + +that this sum is equal to some number s + + align:start position:0% +that this sum is equal to some number s + + + align:start position:0% +that this sum is equal to some number s +which is the sum of all of the these + + align:start position:0% +which is the sum of all of the these + + + align:start position:0% +which is the sum of all of the these +numbers here. + + align:start position:0% + + + + align:start position:0% + +The first thing that I'm going to do is + + align:start position:0% +The first thing that I'm going to do is + + + align:start position:0% +The first thing that I'm going to do is +I'm going to multiply by x. + + align:start position:0% +I'm going to multiply by x. + + + align:start position:0% +I'm going to multiply by x. +Okay. So if I multiply by x, + + align:start position:0% +Okay. So if I multiply by x, + + + align:start position:0% +Okay. So if I multiply by x, +let's think about that. I multiply by x + + align:start position:0% +let's think about that. I multiply by x + + + align:start position:0% +let's think about that. I multiply by x +on both the left and the right hand + + align:start position:0% +on both the left and the right hand + + + align:start position:0% +on both the left and the right hand +side. Then on the left side I get x + + + align:start position:0% +side. Then on the left side I get x + + + + align:start position:0% +side. Then on the left side I get x + +x^2 + x cubed plus and so forth. And on + + align:start position:0% +x^2 + x cubed plus and so forth. And on + + + align:start position:0% +x^2 + x cubed plus and so forth. And on +the right side I get s * x. + + align:start position:0% + + + + align:start position:0% + +And now I'm going to subtract the two + + align:start position:0% +And now I'm going to subtract the two + + + align:start position:0% +And now I'm going to subtract the two +equations one from the other. And + + align:start position:0% +equations one from the other. And + + + align:start position:0% +equations one from the other. And +there's a very very substantial + + align:start position:0% +there's a very very substantial + + + align:start position:0% +there's a very very substantial +cancellation. This whole tail here gets + + align:start position:0% +cancellation. This whole tail here gets + + + align:start position:0% +cancellation. This whole tail here gets +canceled off. And the only thing that's + + align:start position:0% +canceled off. And the only thing that's + + + align:start position:0% +canceled off. And the only thing that's +left is the one. So when I subtract + + align:start position:0% +left is the one. So when I subtract + + + align:start position:0% +left is the one. So when I subtract +I get one on the left hand side and on + + align:start position:0% +I get one on the left hand side and on + + + align:start position:0% +I get one on the left hand side and on +the right hand side I get s + + align:start position:0% +the right hand side I get s + + + align:start position:0% +the right hand side I get s +time uh minus s * x. + + align:start position:0% +time uh minus s * x. + + + align:start position:0% +time uh minus s * x. +All right. + + align:start position:0% + + + + align:start position:0% + +And now uh that can be rewritten as s * + + align:start position:0% +And now uh that can be rewritten as s * + + + align:start position:0% +And now uh that can be rewritten as s * +1 - x. And so I've got my my formula + + align:start position:0% +1 - x. And so I've got my my formula + + + align:start position:0% +1 - x. And so I've got my my formula +here. This is 1 over 1 - x is equal to + + align:start position:0% +here. This is 1 over 1 - x is equal to + + + align:start position:0% +here. This is 1 over 1 - x is equal to +s. + + align:start position:0% +s. + + + align:start position:0% +s. +Right. + + align:start position:0% + + + + align:start position:0% + +Now, + + align:start position:0% +Now, + + + align:start position:0% +Now, +this reasoning + + align:start position:0% +this reasoning + + + align:start position:0% +this reasoning +is has one flaw. + + align:start position:0% +is has one flaw. + + + align:start position:0% +is has one flaw. +It's not complete. And the this + + align:start position:0% +It's not complete. And the this + + + align:start position:0% +It's not complete. And the this +reasoning is is is basically correct + + align:start position:0% +reasoning is is is basically correct + + + align:start position:0% +reasoning is is is basically correct +but it's incomplete + + align:start position:0% + + + + align:start position:0% + +uh because + + align:start position:0% +uh because + + + align:start position:0% +uh because +it requires + + align:start position:0% + + + + align:start position:0% + +that s exists + + align:start position:0% + + + + align:start position:0% + +for example it doesn't make any sense in + + align:start position:0% +for example it doesn't make any sense in + + + align:start position:0% +for example it doesn't make any sense in +the case x= 1. So for example in the + + align:start position:0% +the case x= 1. So for example in the + + + align:start position:0% +the case x= 1. So for example in the +case s x x= 1 we have 1 + 1 + 1 + etc + + align:start position:0% +case s x x= 1 we have 1 + 1 + 1 + etc + + + align:start position:0% +case s x x= 1 we have 1 + 1 + 1 + etc +equals whatever we call s and then when + + align:start position:0% +equals whatever we call s and then when + + + align:start position:0% +equals whatever we call s and then when +we multiply through by 1 we get 1 + 1 + + + align:start position:0% +we multiply through by 1 we get 1 + 1 + + + + align:start position:0% +we multiply through by 1 we get 1 + 1 + +1 + + + align:start position:0% +1 + + + + align:start position:0% +1 + += s * 1. And now you see that the + + align:start position:0% += s * 1. And now you see that the + + + align:start position:0% += s * 1. And now you see that the +subtraction gives us infinity minus + + align:start position:0% +subtraction gives us infinity minus + + + align:start position:0% +subtraction gives us infinity minus +infinity is equal to infinity minus + + align:start position:0% +infinity is equal to infinity minus + + + align:start position:0% +infinity is equal to infinity minus +infinity. That's what's really going on + + align:start position:0% +infinity. That's what's really going on + + + align:start position:0% +infinity. That's what's really going on +in the argument in this in this context. + + align:start position:0% +in the argument in this in this context. + + + align:start position:0% +in the argument in this in this context. +So it's just nonsense. I mean it doesn't + + align:start position:0% +So it's just nonsense. I mean it doesn't + + + align:start position:0% +So it's just nonsense. I mean it doesn't +give us anything meaningful. + + align:start position:0% +give us anything meaningful. + + + align:start position:0% +give us anything meaningful. +So the the this argument it's great and + + align:start position:0% +So the the this argument it's great and + + + align:start position:0% +So the the this argument it's great and +it gives us the right answer but not + + align:start position:0% +it gives us the right answer but not + + + align:start position:0% +it gives us the right answer but not +always and the times when it gives us + + align:start position:0% +always and the times when it gives us + + + align:start position:0% +always and the times when it gives us +the answer the correct answer is when + + align:start position:0% +the answer the correct answer is when + + + align:start position:0% +the answer the correct answer is when +the series is convergent + + align:start position:0% +the series is convergent + + + align:start position:0% +the series is convergent +and that's why we care about convergence + + align:start position:0% +and that's why we care about convergence + + + align:start position:0% +and that's why we care about convergence +because we want manipulations like this + + align:start position:0% +because we want manipulations like this + + + align:start position:0% +because we want manipulations like this +to be allowed. + + align:start position:0% + + + + align:start position:0% + +So the good case, this is the red case + + align:start position:0% +So the good case, this is the red case + + + align:start position:0% +So the good case, this is the red case +that we were describing last time and + + align:start position:0% +that we were describing last time and + + + align:start position:0% +that we were describing last time and +it's the bad case. But what we want is + + align:start position:0% +it's the bad case. But what we want is + + + align:start position:0% +it's the bad case. But what we want is +the good case, the convergent case. And + + align:start position:0% +the good case, the convergent case. And + + + align:start position:0% +the good case, the convergent case. And +that is the case when x is less than + + align:start position:0% +that is the case when x is less than + + + align:start position:0% +that is the case when x is less than +one. So this is the convergent case + + align:start position:0% + + + + align:start position:0% + +now. Okay. So there are there are much + + align:start position:0% +now. Okay. So there are there are much + + + align:start position:0% +now. Okay. So there are there are much +more detailed things to check exactly + + align:start position:0% +more detailed things to check exactly + + + align:start position:0% +more detailed things to check exactly +what's going on. But I'm going to just + + align:start position:0% +what's going on. But I'm going to just + + + align:start position:0% +what's going on. But I'm going to just +say general words about how you + + align:start position:0% +say general words about how you + + + align:start position:0% +say general words about how you +recognize convergence. And then we're + + align:start position:0% +recognize convergence. And then we're + + + align:start position:0% +recognize convergence. And then we're +not going to worry about so much about + + align:start position:0% +not going to worry about so much about + + + align:start position:0% +not going to worry about so much about +convergence because it works very very + + align:start position:0% +convergence because it works very very + + + align:start position:0% +convergence because it works very very +well and it's always easy to diagnose + + align:start position:0% +well and it's always easy to diagnose + + + align:start position:0% +well and it's always easy to diagnose +when there's convergence with a power + + align:start position:0% +when there's convergence with a power + + + align:start position:0% +when there's convergence with a power +series. + + align:start position:0% +series. + + + align:start position:0% +series. +All right. So here's the general setup. + + align:start position:0% + + + + align:start position:0% + +The general setup is that we have + + align:start position:0% +The general setup is that we have + + + align:start position:0% +The general setup is that we have +not just the coefficients one all the + + align:start position:0% +not just the coefficients one all the + + + align:start position:0% +not just the coefficients one all the +time but any numbers here + + align:start position:0% + + + + align:start position:0% + +dot dot dot and we abbreviate that with + + align:start position:0% +dot dot dot and we abbreviate that with + + + align:start position:0% +dot dot dot and we abbreviate that with +this summation notation. This is the sum + + align:start position:0% +this summation notation. This is the sum + + + align:start position:0% +this summation notation. This is the sum +a n x to the n n n n n n n n n n n n n n + + align:start position:0% +a n x to the n n n n n n n n n n n n n n + + + align:start position:0% +a n x to the n n n n n n n n n n n n n n +n n n n n n n= 0 to infinity + + align:start position:0% +n n n n n n n= 0 to infinity + + + align:start position:0% +n n n n n n n= 0 to infinity +and that's what's known as a power + + align:start position:0% +and that's what's known as a power + + + align:start position:0% +and that's what's known as a power +series. + + align:start position:0% + + + + align:start position:0% + +Fortunately, there's a very simple rule + + align:start position:0% +Fortunately, there's a very simple rule + + + align:start position:0% +Fortunately, there's a very simple rule +about how power series converge and it's + + align:start position:0% +about how power series converge and it's + + + align:start position:0% +about how power series converge and it's +the following. + + align:start position:0% +the following. + + + align:start position:0% +the following. +There's a magic number r which depends + + align:start position:0% +There's a magic number r which depends + + + align:start position:0% +There's a magic number r which depends +on these numbers here such that and this + + align:start position:0% +on these numbers here such that and this + + + align:start position:0% +on these numbers here such that and this +thing is known as a radius of + + align:start position:0% +thing is known as a radius of + + + align:start position:0% +thing is known as a radius of +convergence + + align:start position:0% + + + + align:start position:0% + +in the problem that we had it's this + + align:start position:0% +in the problem that we had it's this + + + align:start position:0% +in the problem that we had it's this +number one here this thing works for x + + align:start position:0% +number one here this thing works for x + + + align:start position:0% +number one here this thing works for x +less than one in our case it's maybe x + + align:start position:0% +less than one in our case it's maybe x + + + align:start position:0% +less than one in our case it's maybe x +less than r so that's some symmetric + + align:start position:0% +less than r so that's some symmetric + + + align:start position:0% +less than r so that's some symmetric +interval right that's the same as minus + + align:start position:0% +interval right that's the same as minus + + + align:start position:0% +interval right that's the same as minus +r less than x less than are + + align:start position:0% +r less than x less than are + + + align:start position:0% +r less than x less than are +and uh this is the so where there's + + align:start position:0% +and uh this is the so where there's + + + align:start position:0% +and uh this is the so where there's +convergence + + align:start position:0% +convergence + + + align:start position:0% +convergence +okay where the series converges + + align:start position:0% + + + + align:start position:0% + +converges + + align:start position:0% +converges + + + align:start position:0% +converges +and + + align:start position:0% +and + + + align:start position:0% +and +then there's the region where every + + align:start position:0% +then there's the region where every + + + align:start position:0% +then there's the region where every +computation that you give will give you + + align:start position:0% +computation that you give will give you + + + align:start position:0% +computation that you give will give you +nonsense. + + align:start position:0% +nonsense. + + + align:start position:0% +nonsense. +So x greater than r is the um sum a n x + + align:start position:0% +So x greater than r is the um sum a n x + + + align:start position:0% +So x greater than r is the um sum a n x +to the n diverges. + + align:start position:0% + + + + align:start position:0% + +Um and + + align:start position:0% +Um and + + + align:start position:0% +Um and +x= r is very delicate + + align:start position:0% + + + + align:start position:0% + +borderline + + align:start position:0% + + + + align:start position:0% + +and will not be used by us. + + align:start position:0% + + + + align:start position:0% + +Okay, we're going to stick inside the + + align:start position:0% +Okay, we're going to stick inside the + + + align:start position:0% +Okay, we're going to stick inside the +radius of convergence. + + align:start position:0% +radius of convergence. + + + align:start position:0% +radius of convergence. +Now, the way you'll be able to recognize + + align:start position:0% +Now, the way you'll be able to recognize + + + align:start position:0% +Now, the way you'll be able to recognize +this is the following. What always + + align:start position:0% +this is the following. What always + + + align:start position:0% +this is the following. What always +happens is that these numbers tend to + + align:start position:0% +happens is that these numbers tend to + + + align:start position:0% +happens is that these numbers tend to +zero exponentially fast + + align:start position:0% + + + + align:start position:0% + +fast + + align:start position:0% +fast + + + align:start position:0% +fast +for X in R + + align:start position:0% +for X in R + + + align:start position:0% +for X in R +and + + align:start position:0% + + + + align:start position:0% + +doesn't even tend to zero at all for + + align:start position:0% +doesn't even tend to zero at all for + + + align:start position:0% +doesn't even tend to zero at all for +X greater than R. + + align:start position:0% +X greater than R. + + + align:start position:0% +X greater than R. +All right. So, so you'll just it'll be + + align:start position:0% +All right. So, so you'll just it'll be + + + align:start position:0% +All right. So, so you'll just it'll be +totally obvious when you look at this + + align:start position:0% +totally obvious when you look at this + + + align:start position:0% +totally obvious when you look at this +series here. What's happening when x + + align:start position:0% +series here. What's happening when x + + + align:start position:0% +series here. What's happening when x +less than r is that the numbers are + + align:start position:0% +less than r is that the numbers are + + + align:start position:0% +less than r is that the numbers are +getting smaller and smaller. I'm less + + align:start position:0% +getting smaller and smaller. I'm less + + + align:start position:0% +getting smaller and smaller. I'm less +than one. When x is bigger than one, the + + align:start position:0% +than one. When x is bigger than one, the + + + align:start position:0% +than one. When x is bigger than one, the +numbers are getting bigger and bigger. + + align:start position:0% +numbers are getting bigger and bigger. + + + align:start position:0% +numbers are getting bigger and bigger. +There's no chance that the series + + align:start position:0% +There's no chance that the series + + + align:start position:0% +There's no chance that the series +converges. So that's going to be the + + align:start position:0% +converges. So that's going to be the + + + align:start position:0% +converges. So that's going to be the +case with all power series. there's + + align:start position:0% +case with all power series. there's + + + align:start position:0% +case with all power series. there's +going to be a cutoff and it'll be one + + align:start position:0% +going to be a cutoff and it'll be one + + + align:start position:0% +going to be a cutoff and it'll be one +particular number and below that it'll + + align:start position:0% +particular number and below that it'll + + + align:start position:0% +particular number and below that it'll +be obvious that you have convergence and + + align:start position:0% +be obvious that you have convergence and + + + align:start position:0% +be obvious that you have convergence and +you'll be able to do computations and + + align:start position:0% +you'll be able to do computations and + + + align:start position:0% +you'll be able to do computations and +above that every formula will be wrong + + align:start position:0% +above that every formula will be wrong + + + align:start position:0% +above that every formula will be wrong +and won't make sense. So it's a very + + align:start position:0% +and won't make sense. So it's a very + + + align:start position:0% +and won't make sense. So it's a very +clean thing. There is this very subtle + + align:start position:0% +clean thing. There is this very subtle + + + align:start position:0% +clean thing. There is this very subtle +borderline but we're not going to + + align:start position:0% +borderline but we're not going to + + + align:start position:0% +borderline but we're not going to +discuss that in this in this class and + + align:start position:0% +discuss that in this in this class and + + + align:start position:0% +discuss that in this in this class and +it's actually not used uh uh in direct + + align:start position:0% +it's actually not used uh uh in direct + + + align:start position:0% +it's actually not used uh uh in direct +studies of power series. How do you tell + + align:start position:0% +studies of power series. How do you tell + + + align:start position:0% +studies of power series. How do you tell +when it's when the numbers are declining + + align:start position:0% +when it's when the numbers are declining + + + align:start position:0% +when it's when the numbers are declining +exponentially fast versus it's just + + align:start position:0% +exponentially fast versus it's just + + + align:start position:0% +exponentially fast versus it's just +In other words, 1 /x you zero. The + + align:start position:0% +In other words, 1 /x you zero. The + + + align:start position:0% +In other words, 1 /x you zero. The +question is how could why why was I able + + align:start position:0% +question is how could why why was I able + + + align:start position:0% +question is how could why why was I able +to tell you this word here? Why was I + + align:start position:0% +to tell you this word here? Why was I + + + align:start position:0% +to tell you this word here? Why was I +able to tell you not only is it going to + + align:start position:0% +able to tell you not only is it going to + + + align:start position:0% +able to tell you not only is it going to +zero but it's going exponentially fast? + + align:start position:0% +zero but it's going exponentially fast? + + + align:start position:0% +zero but it's going exponentially fast? +I'm telling you extra information. I'm + + align:start position:0% +I'm telling you extra information. I'm + + + align:start position:0% +I'm telling you extra information. I'm +telling you it always goes exponentially + + align:start position:0% +telling you it always goes exponentially + + + align:start position:0% +telling you it always goes exponentially +fast. You can identify it. In other + + align:start position:0% +fast. You can identify it. In other + + + align:start position:0% +fast. You can identify it. In other +words, in other words, in other words, + + align:start position:0% +words, in other words, in other words, + + + align:start position:0% +words, in other words, in other words, +you'll see it and it will happen every + + align:start position:0% +you'll see it and it will happen every + + + align:start position:0% +you'll see it and it will happen every +single time. I'm just promising you that + + align:start position:0% +single time. I'm just promising you that + + + align:start position:0% +single time. I'm just promising you that +it works that way. And it's really for + + align:start position:0% +it works that way. And it's really for + + + align:start position:0% +it works that way. And it's really for +the same reason that it works that way + + align:start position:0% +the same reason that it works that way + + + align:start position:0% +the same reason that it works that way +here that these are powers. And what's + + align:start position:0% +here that these are powers. And what's + + + align:start position:0% +here that these are powers. And what's +going on over here is there are it's + + align:start position:0% +going on over here is there are it's + + + align:start position:0% +going on over here is there are it's +close to powers with these a + + align:start position:0% +close to powers with these a + + + align:start position:0% +close to powers with these a +right + + align:start position:0% +right + + + align:start position:0% +right +there's a long discussion of radius of + + align:start position:0% +there's a long discussion of radius of + + + align:start position:0% +there's a long discussion of radius of +convergence in many textbooks but really + + align:start position:0% +convergence in many textbooks but really + + + align:start position:0% +convergence in many textbooks but really +it's it's not necessary all right for + + align:start position:0% +it's it's not necessary all right for + + + align:start position:0% +it's it's not necessary all right for +this purpose. + + align:start position:0% +this purpose. + + + align:start position:0% +this purpose. +Yeah. + + align:start position:0% +Yeah. + + + align:start position:0% +Yeah. +The question was how do you find r? Yes. + + align:start position:0% +The question was how do you find r? Yes. + + + align:start position:0% +The question was how do you find r? Yes. +So I just said there's a long discussion + + align:start position:0% +So I just said there's a long discussion + + + align:start position:0% +So I just said there's a long discussion +of how you find the radius of + + align:start position:0% +of how you find the radius of + + + align:start position:0% +of how you find the radius of +convergence in textbooks, but we will we + + align:start position:0% +convergence in textbooks, but we will we + + + align:start position:0% +convergence in textbooks, but we will we +will not be discussing that here and it + + align:start position:0% +will not be discussing that here and it + + + align:start position:0% +will not be discussing that here and it +won't be necessary for you because it + + align:start position:0% +won't be necessary for you because it + + + align:start position:0% +won't be necessary for you because it +will be obvious in any given series what + + align:start position:0% +will be obvious in any given series what + + + align:start position:0% +will be obvious in any given series what +what the r is. It will always be either + + align:start position:0% +what the r is. It will always be either + + + align:start position:0% +what the r is. It will always be either +one or infinity. It will always work for + + align:start position:0% +one or infinity. It will always work for + + + align:start position:0% +one or infinity. It will always work for +all x or maybe it'll stop at some point + + align:start position:0% +all x or maybe it'll stop at some point + + + align:start position:0% +all x or maybe it'll stop at some point +but it'll be very clear where it stops + + align:start position:0% +but it'll be very clear where it stops + + + align:start position:0% +but it'll be very clear where it stops +as it is for the for the geometric + + align:start position:0% +as it is for the for the geometric + + + align:start position:0% +as it is for the for the geometric +series. + + align:start position:0% +series. + + + align:start position:0% +series. +All right. + + align:start position:0% +All right. + + + align:start position:0% +All right. +Okay. So now I need to give you the the + + align:start position:0% +Okay. So now I need to give you the the + + + align:start position:0% +Okay. So now I need to give you the the +basic facts and give you a few examples. + + align:start position:0% + + + + align:start position:0% + +So why are we looking at these series? + + align:start position:0% + + + + align:start position:0% + +Uh the answer is we're looking at these + + align:start position:0% +Uh the answer is we're looking at these + + + align:start position:0% +Uh the answer is we're looking at these +series because the role that they play + + align:start position:0% +series because the role that they play + + + align:start position:0% +series because the role that they play +is exactly the reverse of this inequal + + align:start position:0% +is exactly the reverse of this inequal + + + align:start position:0% +is exactly the reverse of this inequal +of this equation here. + + align:start position:0% +of this equation here. + + + align:start position:0% +of this equation here. +That is and this is a theme which I've + + align:start position:0% +That is and this is a theme which I've + + + align:start position:0% +That is and this is a theme which I've +tried to emphasize throughout this + + align:start position:0% +tried to emphasize throughout this + + + align:start position:0% +tried to emphasize throughout this +course. You can read equalities in two + + align:start position:0% +course. You can read equalities in two + + + align:start position:0% +course. You can read equalities in two +directions. + + align:start position:0% +directions. + + + align:start position:0% +directions. +Both are interesting. Typically you can + + align:start position:0% +Both are interesting. Typically you can + + + align:start position:0% +Both are interesting. Typically you can +think I don't know what the value of + + align:start position:0% +think I don't know what the value of + + + align:start position:0% +think I don't know what the value of +this is. Here's a way of evaluating it. + + align:start position:0% +this is. Here's a way of evaluating it. + + + align:start position:0% +this is. Here's a way of evaluating it. +In other words, the left side the the + + align:start position:0% +In other words, the left side the the + + + align:start position:0% +In other words, the left side the the +right side is a formula for the left + + align:start position:0% +right side is a formula for the left + + + align:start position:0% +right side is a formula for the left +side. Or you can think of the left side + + align:start position:0% +side. Or you can think of the left side + + + align:start position:0% +side. Or you can think of the left side +as being a formula for the right side. + + align:start position:0% + + + + align:start position:0% + +And the idea of series is that they're + + align:start position:0% +And the idea of series is that they're + + + align:start position:0% +And the idea of series is that they're +flexible enough to represent all of the + + align:start position:0% +flexible enough to represent all of the + + + align:start position:0% +flexible enough to represent all of the +functions that we've encountered in this + + align:start position:0% +functions that we've encountered in this + + + align:start position:0% +functions that we've encountered in this +course. + + align:start position:0% +course. + + + align:start position:0% +course. +Uh this is the tool which is very much + + align:start position:0% +Uh this is the tool which is very much + + + align:start position:0% +Uh this is the tool which is very much +like the decimal expansion which allows + + align:start position:0% +like the decimal expansion which allows + + + align:start position:0% +like the decimal expansion which allows +you to represent numbers like the square + + align:start position:0% +you to represent numbers like the square + + + align:start position:0% +you to represent numbers like the square +root of two. Now we're going to be + + align:start position:0% +root of two. Now we're going to be + + + align:start position:0% +root of two. Now we're going to be +representing all the numbers all the + + align:start position:0% +representing all the numbers all the + + + align:start position:0% +representing all the numbers all the +functions that we know e to the x arc + + align:start position:0% +functions that we know e to the x arc + + + align:start position:0% +functions that we know e to the x arc +tangent s cosine all of those functions + + align:start position:0% +tangent s cosine all of those functions + + + align:start position:0% +tangent s cosine all of those functions +become completely flexible and + + align:start position:0% +become completely flexible and + + + align:start position:0% +become completely flexible and +completely available to us and + + align:start position:0% +completely available to us and + + + align:start position:0% +completely available to us and +computationally available to us + + align:start position:0% +computationally available to us + + + align:start position:0% +computationally available to us +directly. So that's that's what this is + + align:start position:0% +directly. So that's that's what this is + + + align:start position:0% +directly. So that's that's what this is +a tool for and it's just like decimal + + align:start position:0% +a tool for and it's just like decimal + + + align:start position:0% +a tool for and it's just like decimal +expansions giving you a handle on all + + align:start position:0% +expansions giving you a handle on all + + + align:start position:0% +expansions giving you a handle on all +real numbers. + + align:start position:0% + + + + align:start position:0% + +So here's how it works. + + align:start position:0% +So here's how it works. + + + align:start position:0% +So here's how it works. +the rules + + align:start position:0% +the rules + + + align:start position:0% +the rules +for + + align:start position:0% +for + + + align:start position:0% +for +um convergent power series + + align:start position:0% + + + + align:start position:0% + +um are just like + + align:start position:0% + + + + align:start position:0% + +polomials. + + align:start position:0% + + + + align:start position:0% + +All of the manipulations that you do for + + align:start position:0% +All of the manipulations that you do for + + + align:start position:0% +All of the manipulations that you do for +power serieses are essentially the same + + align:start position:0% +power serieses are essentially the same + + + align:start position:0% +power serieses are essentially the same +as for polomials. So what kinds of + + align:start position:0% +as for polomials. So what kinds of + + + align:start position:0% +as for polomials. So what kinds of +things do we do with polomials? + + align:start position:0% +things do we do with polomials? + + + align:start position:0% +things do we do with polomials? +We add them. + + align:start position:0% + + + + align:start position:0% + +We multiply them together. + + align:start position:0% + + + + align:start position:0% + +We do substitutions, + + align:start position:0% +We do substitutions, + + + align:start position:0% +We do substitutions, +right? We take one function of another + + align:start position:0% +right? We take one function of another + + + align:start position:0% +right? We take one function of another +function. + + align:start position:0% +function. + + + align:start position:0% +function. +We divide them. + + align:start position:0% + + + + align:start position:0% + +Okay. And these are all really not very + + align:start position:0% +Okay. And these are all really not very + + + align:start position:0% +Okay. And these are all really not very +surprising operations and we'll be able + + align:start position:0% +surprising operations and we'll be able + + + align:start position:0% +surprising operations and we'll be able +to do them with power series 2. The ones + + align:start position:0% +to do them with power series 2. The ones + + + align:start position:0% +to do them with power series 2. The ones +that are interesting really interesting + + align:start position:0% +that are interesting really interesting + + + align:start position:0% +that are interesting really interesting +for calculus are the last two. We + + align:start position:0% +for calculus are the last two. We + + + align:start position:0% +for calculus are the last two. We +differentiate them + + align:start position:0% +differentiate them + + + align:start position:0% +differentiate them +and we integrate them. + + align:start position:0% + + + + align:start position:0% + +And all of these operations we'll be + + align:start position:0% +And all of these operations we'll be + + + align:start position:0% +And all of these operations we'll be +able to do for power series as well. + + align:start position:0% + + + + align:start position:0% + +So now let's explain the high points of + + align:start position:0% +So now let's explain the high points of + + + align:start position:0% +So now let's explain the high points of +this which is mainly just the + + align:start position:0% +this which is mainly just the + + + align:start position:0% +this which is mainly just the +differentiation and the integration + + align:start position:0% +differentiation and the integration + + + align:start position:0% +differentiation and the integration +part. So if I take a series like this + + align:start position:0% + + + + align:start position:0% + +and so forth, the formula for its + + align:start position:0% +and so forth, the formula for its + + + align:start position:0% +and so forth, the formula for its +derivative is just like polomials. + + align:start position:0% +derivative is just like polomials. + + + align:start position:0% +derivative is just like polomials. +That's what I just said. It's just like + + align:start position:0% +That's what I just said. It's just like + + + align:start position:0% +That's what I just said. It's just like +polinomials. So the derivative of the + + align:start position:0% +polinomials. So the derivative of the + + + align:start position:0% +polinomials. So the derivative of the +constant is zero. The derivative of this + + align:start position:0% +constant is zero. The derivative of this + + + align:start position:0% +constant is zero. The derivative of this +term is a1. This one is + 2 a2x. + + align:start position:0% +term is a1. This one is + 2 a2x. + + + align:start position:0% +term is a1. This one is + 2 a2x. +This one is 3 a3 x^2 + etc. That's the + + align:start position:0% +This one is 3 a3 x^2 + etc. That's the + + + align:start position:0% +This one is 3 a3 x^2 + etc. That's the +formula. + + align:start position:0% +formula. + + + align:start position:0% +formula. +Similarly, + + align:start position:0% +Similarly, + + + align:start position:0% +Similarly, +if I integrate, + + align:start position:0% + + + + align:start position:0% + +well, there's an unknown constant which + + align:start position:0% +well, there's an unknown constant which + + + align:start position:0% +well, there's an unknown constant which +I'm going to put first rather than last, + + align:start position:0% +I'm going to put first rather than last, + + + align:start position:0% +I'm going to put first rather than last, +which corresponds sort of to the a z + + align:start position:0% +which corresponds sort of to the a z + + + align:start position:0% +which corresponds sort of to the a z +term which is going to get wiped out. + + align:start position:0% +term which is going to get wiped out. + + + align:start position:0% +term which is going to get wiped out. +That a zero term suddenly becomes a zox + + align:start position:0% +That a zero term suddenly becomes a zox + + + align:start position:0% +That a zero term suddenly becomes a zox +and the anti-derivative of this next + + align:start position:0% +and the anti-derivative of this next + + + align:start position:0% +and the anti-derivative of this next +term is a1x^2 over 2 and the next term + + align:start position:0% +term is a1x^2 over 2 and the next term + + + align:start position:0% +term is a1x^2 over 2 and the next term +is a2x cubed over 3 + + align:start position:0% +is a2x cubed over 3 + + + align:start position:0% +is a2x cubed over 3 +and so forth. + + align:start position:0% +and so forth. + + + align:start position:0% +and so forth. +Yeah. Question is that a series or a + + align:start position:0% +Yeah. Question is that a series or a + + + align:start position:0% +Yeah. Question is that a series or a +polomial? Is this a series or a + + align:start position:0% +polomial? Is this a series or a + + + align:start position:0% +polomial? Is this a series or a +polomial? Good question. It's a polomial + + align:start position:0% +polomial? Good question. It's a polomial + + + align:start position:0% +polomial? Good question. It's a polomial +if it ends. If it goes on infinitely + + align:start position:0% +if it ends. If it goes on infinitely + + + align:start position:0% +if it ends. If it goes on infinitely +far, + + align:start position:0% +far, + + + align:start position:0% +far, +then it's a series. They look + + align:start position:0% +then it's a series. They look + + + align:start position:0% +then it's a series. They look +practically the same. Polinomials and + + align:start position:0% +practically the same. Polinomials and + + + align:start position:0% +practically the same. Polinomials and +series. There's this little dot dot dot + + align:start position:0% +series. There's this little dot dot dot + + + align:start position:0% +series. There's this little dot dot dot +here. + + align:start position:0% +here. + + + align:start position:0% +here. +Is this a series or a polinomial? It's + + align:start position:0% +Is this a series or a polinomial? It's + + + align:start position:0% +Is this a series or a polinomial? It's +the same rule. If it stops at a finite + + align:start position:0% +the same rule. If it stops at a finite + + + align:start position:0% +the same rule. If it stops at a finite +stage, this one stops at a finite stage. + + align:start position:0% +stage, this one stops at a finite stage. + + + align:start position:0% +stage, this one stops at a finite stage. +If it goes on forever, it goes on + + align:start position:0% +If it goes on forever, it goes on + + + align:start position:0% +If it goes on forever, it goes on +forever. So, I thought that series add + + align:start position:0% +forever. So, I thought that series add + + + align:start position:0% +forever. So, I thought that series add +up finite numbers. You can add up terms + + align:start position:0% +up finite numbers. You can add up terms + + + align:start position:0% +up finite numbers. You can add up terms +of x in the series. + + align:start position:0% + + + + align:start position:0% + +Uh + + align:start position:0% +Uh + + + align:start position:0% +Uh +so u an interesting question. So the the + + align:start position:0% +so u an interesting question. So the the + + + align:start position:0% +so u an interesting question. So the the +the question that was just asked is I + + align:start position:0% +the question that was just asked is I + + + align:start position:0% +the question that was just asked is I +thought that a series added up finite + + align:start position:0% +thought that a series added up finite + + + align:start position:0% +thought that a series added up finite +numbers. You could add up x. That was + + align:start position:0% +numbers. You could add up x. That was + + + align:start position:0% +numbers. You could add up x. That was +that was what you said, right? Okay. Now + + align:start position:0% +that was what you said, right? Okay. Now + + + align:start position:0% +that was what you said, right? Okay. Now +notice + + align:start position:0% +notice + + + align:start position:0% +notice +that I pulled that off on you by + + align:start position:0% +that I pulled that off on you by + + + align:start position:0% +that I pulled that off on you by +changing the letter a to the letter x at + + align:start position:0% +changing the letter a to the letter x at + + + align:start position:0% +changing the letter a to the letter x at +the very beginning of this + + align:start position:0% +the very beginning of this + + + align:start position:0% +the very beginning of this +commentary here. + + align:start position:0% +commentary here. + + + align:start position:0% +commentary here. +This is a series. For each individual + + align:start position:0% +This is a series. For each individual + + + align:start position:0% +This is a series. For each individual +value of x, it's a number. So in other + + align:start position:0% +value of x, it's a number. So in other + + + align:start position:0% +value of x, it's a number. So in other +words, if I plug in here x equals a + + align:start position:0% +words, if I plug in here x equals a + + + align:start position:0% +words, if I plug in here x equals a +half, I'm going to add one plus a half + + align:start position:0% +half, I'm going to add one plus a half + + + align:start position:0% +half, I'm going to add one plus a half +plus a/4 plus an eighth and I'll get a + + align:start position:0% +plus a/4 plus an eighth and I'll get a + + + align:start position:0% +plus a/4 plus an eighth and I'll get a +number which is two. And I'll plug in a + + align:start position:0% +number which is two. And I'll plug in a + + + align:start position:0% +number which is two. And I'll plug in a +number over here and I get a number. On + + align:start position:0% +number over here and I get a number. On + + + align:start position:0% +number over here and I get a number. On +the other hand, I can do this for each + + align:start position:0% +the other hand, I can do this for each + + + align:start position:0% +the other hand, I can do this for each +value of x. So the interpretation of + + align:start position:0% +value of x. So the interpretation of + + + align:start position:0% +value of x. So the interpretation of +this is that it's a function of x. And + + align:start position:0% +this is that it's a function of x. And + + + align:start position:0% +this is that it's a function of x. And +similarly, this is a function of x. it + + align:start position:0% +similarly, this is a function of x. it + + + align:start position:0% +similarly, this is a function of x. it +works when you plug in the possible + + align:start position:0% +works when you plug in the possible + + + align:start position:0% +works when you plug in the possible +values of x between minus1 and one. + + align:start position:0% +values of x between minus1 and one. + + + align:start position:0% +values of x between minus1 and one. +So there's so there there's there's + + align:start position:0% +So there's so there there's there's + + + align:start position:0% +So there's so there there's there's +really no distinction there. It's just I + + align:start position:0% +really no distinction there. It's just I + + + align:start position:0% +really no distinction there. It's just I +slipped it past you. These are functions + + align:start position:0% +slipped it past you. These are functions + + + align:start position:0% +slipped it past you. These are functions +of x. + + align:start position:0% +of x. + + + align:start position:0% +of x. +And the notion of a power series is this + + align:start position:0% +And the notion of a power series is this + + + align:start position:0% +And the notion of a power series is this +idea that you put coefficients on a + + align:start position:0% +idea that you put coefficients on a + + + align:start position:0% +idea that you put coefficients on a +series, but then you allow yourself the + + align:start position:0% +series, but then you allow yourself the + + + align:start position:0% +series, but then you allow yourself the +flexibility to stick powers here. And + + align:start position:0% +flexibility to stick powers here. And + + + align:start position:0% +flexibility to stick powers here. And +that's exactly what we're what we're + + align:start position:0% +that's exactly what we're what we're + + + align:start position:0% +that's exactly what we're what we're +doing. Okay. There there are other kinds + + align:start position:0% +doing. Okay. There there are other kinds + + + align:start position:0% +doing. Okay. There there are other kinds +of series where you stick other + + align:start position:0% +of series where you stick other + + + align:start position:0% +of series where you stick other +interesting functions in here like ss + + align:start position:0% +interesting functions in here like ss + + + align:start position:0% +interesting functions in here like ss +and cosiness. There are lots of other + + align:start position:0% +and cosiness. There are lots of other + + + align:start position:0% +and cosiness. There are lots of other +series that people study and these are + + align:start position:0% +series that people study and these are + + + align:start position:0% +series that people study and these are +the simplest ones and all of those + + align:start position:0% +the simplest ones and all of those + + + align:start position:0% +the simplest ones and all of those +examples are extremely helpful for + + align:start position:0% +examples are extremely helpful for + + + align:start position:0% +examples are extremely helpful for +representing functions but we're only + + align:start position:0% +representing functions but we're only + + + align:start position:0% +representing functions but we're only +going to do this example here. + + align:start position:0% +going to do this example here. + + + align:start position:0% +going to do this example here. +All right. So here are the the the two + + align:start position:0% +All right. So here are the the the two + + + align:start position:0% +All right. So here are the the the two +rules. And now there's only one other + + align:start position:0% +rules. And now there's only one other + + + align:start position:0% +rules. And now there's only one other +complication here which I have to + + align:start position:0% +complication here which I have to + + + align:start position:0% +complication here which I have to +explain to you + + align:start position:0% +explain to you + + + align:start position:0% +explain to you +before giving you a bunch of examples to + + align:start position:0% +before giving you a bunch of examples to + + + align:start position:0% +before giving you a bunch of examples to +show you that this works extremely well. + + align:start position:0% +show you that this works extremely well. + + + align:start position:0% +show you that this works extremely well. +And the last thing that I have to do for + + align:start position:0% +And the last thing that I have to do for + + + align:start position:0% +And the last thing that I have to do for +you is explain to you something called + + align:start position:0% +you is explain to you something called + + + align:start position:0% +you is explain to you something called +Taylor's formula. + + align:start position:0% + + + + align:start position:0% + +Taylor's formula is the way you get from + + align:start position:0% +Taylor's formula is the way you get from + + + align:start position:0% +Taylor's formula is the way you get from +the representation that we're used to of + + align:start position:0% +the representation that we're used to of + + + align:start position:0% +the representation that we're used to of +functions to the representation in the + + align:start position:0% +functions to the representation in the + + + align:start position:0% +functions to the representation in the +form of these coefficients. When I gave + + align:start position:0% +form of these coefficients. When I gave + + + align:start position:0% +form of these coefficients. When I gave +you the function e to the x, it didn't + + align:start position:0% +you the function e to the x, it didn't + + + align:start position:0% +you the function e to the x, it didn't +look like a polomial. + + align:start position:0% +look like a polomial. + + + align:start position:0% +look like a polomial. +And we have to figure out which of these + + align:start position:0% +And we have to figure out which of these + + + align:start position:0% +And we have to figure out which of these +guys it is if it's going to fall into + + align:start position:0% +guys it is if it's going to fall into + + + align:start position:0% +guys it is if it's going to fall into +our category here. + + align:start position:0% +our category here. + + + align:start position:0% +our category here. +And here's the formula. I'll explain to + + align:start position:0% +And here's the formula. I'll explain to + + + align:start position:0% +And here's the formula. I'll explain to +you how it works in a second. So the + + align:start position:0% +you how it works in a second. So the + + + align:start position:0% +you how it works in a second. So the +formula is f ofx turns out there's a + + align:start position:0% +formula is f ofx turns out there's a + + + align:start position:0% +formula is f ofx turns out there's a +formula in terms of the derivatives of + + align:start position:0% +formula in terms of the derivatives of + + + align:start position:0% +formula in terms of the derivatives of +f. Namely, you differentiate n times and + + align:start position:0% +f. Namely, you differentiate n times and + + + align:start position:0% +f. Namely, you differentiate n times and +you evaluate it at zero and you divide + + align:start position:0% +you evaluate it at zero and you divide + + + align:start position:0% +you evaluate it at zero and you divide +by n factorial and multiply by x to the + + align:start position:0% +by n factorial and multiply by x to the + + + align:start position:0% +by n factorial and multiply by x to the +n. + + align:start position:0% +n. + + + align:start position:0% +n. +So here's the here's Taylor's formula. + + align:start position:0% +So here's the here's Taylor's formula. + + + align:start position:0% +So here's the here's Taylor's formula. +This tells you what the uh tailaylor + + align:start position:0% +This tells you what the uh tailaylor + + + align:start position:0% +This tells you what the uh tailaylor +series is. + + align:start position:0% +series is. + + + align:start position:0% +series is. +Now about half of our job for the next + + align:start position:0% +Now about half of our job for the next + + + align:start position:0% +Now about half of our job for the next +few minutes is going to be to give + + align:start position:0% +few minutes is going to be to give + + + align:start position:0% +few minutes is going to be to give +examples of this. But let me just + + align:start position:0% +examples of this. But let me just + + + align:start position:0% +examples of this. But let me just +explain to you why this + + align:start position:0% +explain to you why this + + + align:start position:0% +explain to you why this +has to be. If you pick out this number + + align:start position:0% +has to be. If you pick out this number + + + align:start position:0% +has to be. If you pick out this number +here, this is the a n the magic number a + + align:start position:0% +here, this is the a n the magic number a + + + align:start position:0% +here, this is the a n the magic number a +n here. So let's just illustrate it. If + + align:start position:0% +n here. So let's just illustrate it. If + + + align:start position:0% +n here. So let's just illustrate it. If +f ofx + + align:start position:0% +f ofx + + + align:start position:0% +f ofx +happens to be a 0 + a1 x + a2 x^2 + a3 x + + align:start position:0% +happens to be a 0 + a1 x + a2 x^2 + a3 x + + + align:start position:0% +happens to be a 0 + a1 x + a2 x^2 + a3 x +cubed plus dot dot dot and now I + + align:start position:0% +cubed plus dot dot dot and now I + + + align:start position:0% +cubed plus dot dot dot and now I +differentiate it right I get a1 + 2 a2x + + align:start position:0% +differentiate it right I get a1 + 2 a2x + + + align:start position:0% +differentiate it right I get a1 + 2 a2x ++ 3 a3 x^2 + + align:start position:0% ++ 3 a3 x^2 + + + align:start position:0% ++ 3 a3 x^2 +if I differentiate it another time I get + + align:start position:0% +if I differentiate it another time I get + + + align:start position:0% +if I differentiate it another time I get +2 a2 + 3 sorry 3 * 2 a3 x + dot dot dot + + align:start position:0% +2 a2 + 3 sorry 3 * 2 a3 x + dot dot dot + + + align:start position:0% +2 a2 + 3 sorry 3 * 2 a3 x + dot dot dot +and now a third time + + align:start position:0% +and now a third time + + + align:start position:0% +and now a third time +I get 3 * 2 a3 plus + + align:start position:0% +I get 3 * 2 a3 plus + + + align:start position:0% +I get 3 * 2 a3 plus +etc. So this next term is really in + + align:start position:0% +etc. So this next term is really in + + + align:start position:0% +etc. So this next term is really in +disguise 4 * 3 * 2 x sorry uh a 4x + + align:start position:0% +disguise 4 * 3 * 2 x sorry uh a 4x + + + align:start position:0% +disguise 4 * 3 * 2 x sorry uh a 4x +that's what really comes down if I kept + + align:start position:0% +that's what really comes down if I kept + + + align:start position:0% +that's what really comes down if I kept +track of the fourth term there. + + align:start position:0% +track of the fourth term there. + + + align:start position:0% +track of the fourth term there. +So now here is my function. + + align:start position:0% +So now here is my function. + + + align:start position:0% +So now here is my function. +But now you see if I plug in xals 0 I + + align:start position:0% +But now you see if I plug in xals 0 I + + + align:start position:0% +But now you see if I plug in xals 0 I +can pick off + + align:start position:0% +can pick off + + + align:start position:0% +can pick off +the third term. + + align:start position:0% +the third term. + + + align:start position:0% +the third term. +F triple prime of 0 is equal to 3 * 2 * + + align:start position:0% +F triple prime of 0 is equal to 3 * 2 * + + + align:start position:0% +F triple prime of 0 is equal to 3 * 2 * +a3. + + align:start position:0% +a3. + + + align:start position:0% +a3. +Right? Because all the rest of those + + align:start position:0% +Right? Because all the rest of those + + + align:start position:0% +Right? Because all the rest of those +terms when I plug in zero are just zero. + + align:start position:0% +terms when I plug in zero are just zero. + + + align:start position:0% +terms when I plug in zero are just zero. +Here's the the formula. And so the the + + align:start position:0% +Here's the the formula. And so the the + + + align:start position:0% +Here's the the formula. And so the the +the pattern here is this. And what's + + align:start position:0% +the pattern here is this. And what's + + + align:start position:0% +the pattern here is this. And what's +really going on here is this is really 3 + + align:start position:0% +really going on here is this is really 3 + + + align:start position:0% +really going on here is this is really 3 +* 2 * 1 a3. + + align:start position:0% +* 2 * 1 a3. + + + align:start position:0% +* 2 * 1 a3. +And in general, + + align:start position:0% + + + + align:start position:0% + +a n is equal to f nth derivative / n + + align:start position:0% +a n is equal to f nth derivative / n + + + align:start position:0% +a n is equal to f nth derivative / n +factorial. And of course, n factorial, I + + align:start position:0% +factorial. And of course, n factorial, I + + + align:start position:0% +factorial. And of course, n factorial, I +remind you, is n * n -1 + + align:start position:0% +remind you, is n * n -1 + + + align:start position:0% +remind you, is n * n -1 +* n - 2 all the way down to one. + + align:start position:0% + + + + align:start position:0% + +Now there's one more crazy + + align:start position:0% +Now there's one more crazy + + + align:start position:0% +Now there's one more crazy +convention which is always used which is + + align:start position:0% +convention which is always used which is + + + align:start position:0% +convention which is always used which is +that there's something very strange here + + align:start position:0% +that there's something very strange here + + + align:start position:0% +that there's something very strange here +down at zero which is that zero + + align:start position:0% +down at zero which is that zero + + + align:start position:0% +down at zero which is that zero +factorial turns out has to be set equal + + align:start position:0% +factorial turns out has to be set equal + + + align:start position:0% +factorial turns out has to be set equal +to one. All right. So that's that's what + + align:start position:0% +to one. All right. So that's that's what + + + align:start position:0% +to one. All right. So that's that's what +you do in order to make this formula + + align:start position:0% +you do in order to make this formula + + + align:start position:0% +you do in order to make this formula +work out and that's one of the reasons + + align:start position:0% +work out and that's one of the reasons + + + align:start position:0% +work out and that's one of the reasons +for this convention. + + align:start position:0% + + + + align:start position:0% + +All right. So my my uh next goal is to + + align:start position:0% +All right. So my my uh next goal is to + + + align:start position:0% +All right. So my my uh next goal is to +is to give you some examples + + align:start position:0% +is to give you some examples + + + align:start position:0% +is to give you some examples +and let's do + + align:start position:0% + + + + align:start position:0% + +let's do + + align:start position:0% +let's do + + + align:start position:0% +let's do +a couple. + + align:start position:0% +a couple. + + + align:start position:0% +a couple. +So here's well you know + + align:start position:0% +So here's well you know + + + align:start position:0% +So here's well you know +I'm gonna have to let you see a few of + + align:start position:0% +I'm gonna have to let you see a few of + + + align:start position:0% +I'm gonna have to let you see a few of +them next time. But let me just let me + + align:start position:0% +them next time. But let me just let me + + + align:start position:0% +them next time. But let me just let me +just tell you this one which is by far + + align:start position:0% +just tell you this one which is by far + + + align:start position:0% +just tell you this one which is by far +the most impressive. + + align:start position:0% + + + + align:start position:0% + +So what happens with e to the x if the + + align:start position:0% +So what happens with e to the x if the + + + align:start position:0% +So what happens with e to the x if the +function is f ofx is e to the x is that + + align:start position:0% +function is f ofx is e to the x is that + + + align:start position:0% +function is f ofx is e to the x is that +its derivative is also e to the x and + + align:start position:0% +its derivative is also e to the x and + + + align:start position:0% +its derivative is also e to the x and +its second derivative is also e to the x + + align:start position:0% +its second derivative is also e to the x + + + align:start position:0% +its second derivative is also e to the x +and it just keeps on going that way. + + align:start position:0% +and it just keeps on going that way. + + + align:start position:0% +and it just keeps on going that way. +They're all the same. + + align:start position:0% +They're all the same. + + + align:start position:0% +They're all the same. +So that means that these numbers in + + align:start position:0% +So that means that these numbers in + + + align:start position:0% +So that means that these numbers in +Taylor's formula in the numerator + + align:start position:0% +Taylor's formula in the numerator + + + align:start position:0% +Taylor's formula in the numerator +the nth derivative is very easy to + + align:start position:0% +the nth derivative is very easy to + + + align:start position:0% +the nth derivative is very easy to +evaluate. + + align:start position:0% +evaluate. + + + align:start position:0% +evaluate. +It's just e to the x. And if I evaluate + + align:start position:0% +It's just e to the x. And if I evaluate + + + align:start position:0% +It's just e to the x. And if I evaluate +it at xals 0 I just get one. So all of + + align:start position:0% +it at xals 0 I just get one. So all of + + + align:start position:0% +it at xals 0 I just get one. So all of +those numerators are one. + + align:start position:0% +those numerators are one. + + + align:start position:0% +those numerators are one. +So the formula here is the sum n= 0 to + + align:start position:0% +So the formula here is the sum n= 0 to + + + align:start position:0% +So the formula here is the sum n= 0 to +infinity of 1 / n factorial x to the n. + + align:start position:0% + + + + align:start position:0% + +In particular, we now have an honest + + align:start position:0% +In particular, we now have an honest + + + align:start position:0% +In particular, we now have an honest +formula for e to the first power which + + align:start position:0% +formula for e to the first power which + + + align:start position:0% +formula for e to the first power which +is just e, which if I plug it in x= 1, I + + align:start position:0% +is just e, which if I plug it in x= 1, I + + + align:start position:0% +is just e, which if I plug it in x= 1, I +get 1. This is the n=0 term plus one. + + align:start position:0% +get 1. This is the n=0 term plus one. + + + align:start position:0% +get 1. This is the n=0 term plus one. +This is the n= 1 term plus 1 over2 + + align:start position:0% +This is the n= 1 term plus 1 over2 + + + align:start position:0% +This is the n= 1 term plus 1 over2 +factorial plus 1 over 3 factorial plus 1 + + align:start position:0% +factorial plus 1 over 3 factorial plus 1 + + + align:start position:0% +factorial plus 1 over 3 factorial plus 1 +over 4 factorial. + + align:start position:0% + + + + align:start position:0% + +All right. So this is our first honest + + align:start position:0% +All right. So this is our first honest + + + align:start position:0% +All right. So this is our first honest +formula for e and also this is how you + + align:start position:0% +formula for e and also this is how you + + + align:start position:0% +formula for e and also this is how you +you compute the exponential function. + + align:start position:0% + + + + align:start position:0% + +Finally, + + align:start position:0% + + + + align:start position:0% + +if you take a function like sinx, + + align:start position:0% +if you take a function like sinx, + + + align:start position:0% +if you take a function like sinx, +what you'll discover is that we can + + align:start position:0% +what you'll discover is that we can + + + align:start position:0% +what you'll discover is that we can +complete the sort of strange business + + align:start position:0% +complete the sort of strange business + + + align:start position:0% +complete the sort of strange business +that we did at the beginning of the + + align:start position:0% +that we did at the beginning of the + + + align:start position:0% +that we did at the beginning of the +course or cossinex + + align:start position:0% + + + + align:start position:0% + +where we took the uh linear and + + align:start position:0% +where we took the uh linear and + + + align:start position:0% +where we took the uh linear and +quadratic approximations. Now, we're + + align:start position:0% +quadratic approximations. Now, we're + + + align:start position:0% +quadratic approximations. Now, we're +going to get complete formulas for these + + align:start position:0% +going to get complete formulas for these + + + align:start position:0% +going to get complete formulas for these +functions. + + align:start position:0% +functions. + + + align:start position:0% +functions. +Sin x turns out to be equal to x - x cub + + align:start position:0% +Sin x turns out to be equal to x - x cub + + + align:start position:0% +Sin x turns out to be equal to x - x cub +over 3 factorial + x 5 over 5 factorial + + align:start position:0% +over 3 factorial + x 5 over 5 factorial + + + align:start position:0% +over 3 factorial + x 5 over 5 factorial +- x 7th / 7 factorial + + align:start position:0% +- x 7th / 7 factorial + + + align:start position:0% +- x 7th / 7 factorial +etc. + + align:start position:0% +etc. + + + align:start position:0% +etc. +And cossine x is equal to 1 - x^2 over 2 + + align:start position:0% +And cossine x is equal to 1 - x^2 over 2 + + + align:start position:0% +And cossine x is equal to 1 - x^2 over 2 +factorial. That's the same as this 2 + + align:start position:0% +factorial. That's the same as this 2 + + + align:start position:0% +factorial. That's the same as this 2 +here + + align:start position:0% +here + + + align:start position:0% +here +plus x 4th over 4 factorial - x 6 / 6 + + align:start position:0% +plus x 4th over 4 factorial - x 6 / 6 + + + align:start position:0% +plus x 4th over 4 factorial - x 6 / 6 +factorial plus etc. Now these may feel + + align:start position:0% +factorial plus etc. Now these may feel + + + align:start position:0% +factorial plus etc. Now these may feel +like they're hard to memorize because + + align:start position:0% +like they're hard to memorize because + + + align:start position:0% +like they're hard to memorize because +I've just pulled them out of a hat. + + align:start position:0% +I've just pulled them out of a hat. + + + align:start position:0% +I've just pulled them out of a hat. +Uh, I do expect you to know them. + + align:start position:0% +Uh, I do expect you to know them. + + + align:start position:0% +Uh, I do expect you to know them. +They're actually extremely similar + + align:start position:0% +They're actually extremely similar + + + align:start position:0% +They're actually extremely similar +formulas. The exponential here just has + + align:start position:0% +formulas. The exponential here just has + + + align:start position:0% +formulas. The exponential here just has +this collection of factorials. The sign + + align:start position:0% +this collection of factorials. The sign + + + align:start position:0% +this collection of factorials. The sign +is all the odd powers with alternating + + align:start position:0% +is all the odd powers with alternating + + + align:start position:0% +is all the odd powers with alternating +signs and the cosine is all the even + + align:start position:0% +signs and the cosine is all the even + + + align:start position:0% +signs and the cosine is all the even +powers with alternating signs. So all + + align:start position:0% +powers with alternating signs. So all + + + align:start position:0% +powers with alternating signs. So all +three of them form part of the same + + align:start position:0% +three of them form part of the same + + + align:start position:0% +three of them form part of the same +family. So this will actually make it + + align:start position:0% +family. So this will actually make it + + + align:start position:0% +family. So this will actually make it +easier for you to remember rather than + + align:start position:0% +easier for you to remember rather than + + + align:start position:0% +easier for you to remember rather than +harder. + + align:start position:0% + + + + align:start position:0% + +And and so with that, I'll leave the + + align:start position:0% +And and so with that, I'll leave the + + + align:start position:0% +And and so with that, I'll leave the +practice on differentiation for next + + align:start position:0% +practice on differentiation for next + + + align:start position:0% +practice on differentiation for next +time. And good luck everybody. I'll talk + + align:start position:0% +time. And good luck everybody. I'll talk + + + align:start position:0% +time. And good luck everybody. I'll talk +to you individually. \ No newline at end of file diff --git a/wmoKns-IQ-E.txt b/wmoKns-IQ-E.txt new file mode 100644 index 0000000000000000000000000000000000000000..5db1bf41f7325f2d4250cbc2ce23caaa6158249d --- /dev/null +++ b/wmoKns-IQ-E.txt @@ -0,0 +1,8131 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license + + align:start position:0% +a Creative Commons license + + + align:start position:0% +a Creative Commons license +your support will help MIT + + align:start position:0% +your support will help MIT + + + align:start position:0% +your support will help MIT +OpenCourseWare continue to offer high + + align:start position:0% +OpenCourseWare continue to offer high + + + align:start position:0% +OpenCourseWare continue to offer high +quality educational resources for free + + align:start position:0% +quality educational resources for free + + + align:start position:0% +quality educational resources for free +to make a donation or view additional + + align:start position:0% +to make a donation or view additional + + + align:start position:0% +to make a donation or view additional +materials from hundreds of MIT courses + + align:start position:0% +materials from hundreds of MIT courses + + + align:start position:0% +materials from hundreds of MIT courses +visit MIT opencourseware at ocw.mit.edu + + align:start position:0% +visit MIT opencourseware at ocw.mit.edu + + + align:start position:0% +visit MIT opencourseware at ocw.mit.edu +alright so today's reading comes from a + + align:start position:0% +alright so today's reading comes from a + + + align:start position:0% +alright so today's reading comes from a +game designer who is Pulsifer who + + align:start position:0% +game designer who is Pulsifer who + + + align:start position:0% +game designer who is Pulsifer who +traditionally working war games I + + align:start position:0% +traditionally working war games I + + + align:start position:0% +traditionally working war games I +believe he's telling us on some of the + + align:start position:0% +believe he's telling us on some of the + + + align:start position:0% +believe he's telling us on some of the +board games as well but for the most + + align:start position:0% +board games as well but for the most + + + align:start position:0% +board games as well but for the most +part I think is recognized poised before + + align:start position:0% +part I think is recognized poised before + + + align:start position:0% +part I think is recognized poised before +the wargaming work and that was actually + + align:start position:0% +the wargaming work and that was actually + + + align:start position:0% +the wargaming work and that was actually +there's actually quite a lot of + + align:start position:0% +there's actually quite a lot of + + + align:start position:0% +there's actually quite a lot of +wargaming journals mostly written by + + align:start position:0% +wargaming journals mostly written by + + + align:start position:0% +wargaming journals mostly written by +designers for fan softball fan or for + + align:start position:0% +designers for fan softball fan or for + + + align:start position:0% +designers for fan softball fan or for +pen or by fans for fans things like the + + align:start position:0% +pen or by fans for fans things like the + + + align:start position:0% +pen or by fans for fans things like the +complete strategists used to be quite a + + align:start position:0% +complete strategists used to be quite a + + + align:start position:0% +complete strategists used to be quite a +PC gamer of wargaming right you know + + align:start position:0% +PC gamer of wargaming right you know + + + align:start position:0% +PC gamer of wargaming right you know +it's like this is what's happening and + + align:start position:0% +it's like this is what's happening and + + + align:start position:0% +it's like this is what's happening and +this these are our thoughts these are + + align:start position:0% +this these are our thoughts these are + + + align:start position:0% +this these are our thoughts these are +critiques and that particular reading I + + align:start position:0% +critiques and that particular reading I + + + align:start position:0% +critiques and that particular reading I +feel is very typical of that sort of + + align:start position:0% +feel is very typical of that sort of + + + align:start position:0% +feel is very typical of that sort of +hero of maybe late 80s early to mid 90s + + align:start position:0% +hero of maybe late 80s early to mid 90s + + + align:start position:0% +hero of maybe late 80s early to mid 90s +magazine publications and it's + + align:start position:0% +magazine publications and it's + + + align:start position:0% +magazine publications and it's +interesting because already at that time + + align:start position:0% +interesting because already at that time + + + align:start position:0% +interesting because already at that time +sure there are people who say wrote the + + align:start position:0% +sure there are people who say wrote the + + + align:start position:0% +sure there are people who say wrote the +core rule sets for various games like + + align:start position:0% +core rule sets for various games like + + + align:start position:0% +core rule sets for various games like +you know Axis and Allies of all things + + align:start position:0% +you know Axis and Allies of all things + + + align:start position:0% +you know Axis and Allies of all things +like Dungeons and Dragons but it wasn't + + align:start position:0% +like Dungeons and Dragons but it wasn't + + + align:start position:0% +like Dungeons and Dragons but it wasn't +going to be this assumption that if + + align:start position:0% +going to be this assumption that if + + + align:start position:0% +going to be this assumption that if +you're interested in something like + + align:start position:0% +you're interested in something like + + + align:start position:0% +you're interested in something like +wargaming you're also interested in + + align:start position:0% +wargaming you're also interested in + + + align:start position:0% +wargaming you're also interested in +creating your own scenarios you are + + align:start position:0% +creating your own scenarios you are + + + align:start position:0% +creating your own scenarios you are +already halfway a game designer and so + + align:start position:0% +already halfway a game designer and so + + + align:start position:0% +already halfway a game designer and so +you have to keep all of these things in + + align:start position:0% +you have to keep all of these things in + + + align:start position:0% +you have to keep all of these things in +mind particular game master has everyone + + align:start position:0% +mind particular game master has everyone + + + align:start position:0% +mind particular game master has everyone +been like a dungeon master or game + + align:start position:0% +been like a dungeon master or game + + + align:start position:0% +been like a dungeon master or game +master for role-playing group ok yeah + + align:start position:0% +master for role-playing group ok yeah + + + align:start position:0% +master for role-playing group ok yeah +basically a game designer yeah yeah you + + align:start position:0% +basically a game designer yeah yeah you + + + align:start position:0% +basically a game designer yeah yeah you +know you're taking rule sets that + + align:start position:0% +know you're taking rule sets that + + + align:start position:0% +know you're taking rule sets that +somebody else came and cherry picking + + align:start position:0% +somebody else came and cherry picking + + + align:start position:0% +somebody else came and cherry picking +the stuff that you really want to work + + align:start position:0% +the stuff that you really want to work + + + align:start position:0% +the stuff that you really want to work +with them discarding the stuff that + + align:start position:0% +with them discarding the stuff that + + + align:start position:0% +with them discarding the stuff that +doesn't end in coming up with with your + + align:start position:0% +doesn't end in coming up with with your + + + align:start position:0% +doesn't end in coming up with with your +own rules so so just I said a sample of + + align:start position:0% +own rules so so just I said a sample of + + + align:start position:0% +own rules so so just I said a sample of +reading I felt I believe this the first + + align:start position:0% +reading I felt I believe this the first + + + align:start position:0% +reading I felt I believe this the first +time I've asked you to read anything + + align:start position:0% +time I've asked you to read anything + + + align:start position:0% +time I've asked you to read anything +from the tabletop book + + align:start position:0% + + + + align:start position:0% + +okay alright chill ranma's first that's + + align:start position:0% +okay alright chill ranma's first that's + + + align:start position:0% +okay alright chill ranma's first that's +true yeah but this particular piece of + + align:start position:0% +true yeah but this particular piece of + + + align:start position:0% +true yeah but this particular piece of +reading host is also nice little time + + align:start position:0% +reading host is also nice little time + + + align:start position:0% +reading host is also nice little time +capsule of how people used to write + + align:start position:0% +capsule of how people used to write + + + align:start position:0% +capsule of how people used to write +about game design it's a fairly modern + + align:start position:0% +about game design it's a fairly modern + + + align:start position:0% +about game design it's a fairly modern +piece of writing but still it still has + + align:start position:0% +piece of writing but still it still has + + + align:start position:0% +piece of writing but still it still has +that same sort of style so there's a lot + + align:start position:0% +that same sort of style so there's a lot + + + align:start position:0% +that same sort of style so there's a lot +of examples of like this is how this + + align:start position:0% +of examples of like this is how this + + + align:start position:0% +of examples of like this is how this +theoretical game is going to be play and + + align:start position:0% +theoretical game is going to be play and + + + align:start position:0% +theoretical game is going to be play and +I'm going to write it out completely in + + align:start position:0% +I'm going to write it out completely in + + + align:start position:0% +I'm going to write it out completely in +pearls you know it's not going to say + + align:start position:0% +pearls you know it's not going to say + + + align:start position:0% +pearls you know it's not going to say +and II and even when it talks when when + + align:start position:0% +and II and even when it talks when when + + + align:start position:0% +and II and even when it talks when when +they refer to games that already exist + + align:start position:0% +they refer to games that already exist + + + align:start position:0% +they refer to games that already exist +like they do cybg yeah yeah yeah I get + + align:start position:0% +like they do cybg yeah yeah yeah I get + + + align:start position:0% +like they do cybg yeah yeah yeah I get +the explained on they explained that the + + align:start position:0% +the explained on they explained that the + + + align:start position:0% +the explained on they explained that the +mechanic said that discussing about in + + align:start position:0% +mechanic said that discussing about in + + + align:start position:0% +mechanic said that discussing about in +prose it's not like in point form or + + align:start position:0% +prose it's not like in point form or + + + align:start position:0% +prose it's not like in point form or +anything like that it's just free free + + align:start position:0% +anything like that it's just free free + + + align:start position:0% +anything like that it's just free free +prose I don't think there's ever any + + align:start position:0% +prose I don't think there's ever any + + + align:start position:0% +prose I don't think there's ever any +assumption that at all if you + + align:start position:0% +assumption that at all if you + + + align:start position:0% +assumption that at all if you +contributed an essay for something like + + align:start position:0% +contributed an essay for something like + + + align:start position:0% +contributed an essay for something like +the complete strategist that you that + + align:start position:0% +the complete strategist that you that + + + align:start position:0% +the complete strategist that you that +diagrams that you included will be + + align:start position:0% +diagrams that you included will be + + + align:start position:0% +diagrams that you included will be +included into the magazine right because + + align:start position:0% +included into the magazine right because + + + align:start position:0% +included into the magazine right because +a lot of people who actually created + + align:start position:0% +a lot of people who actually created + + + align:start position:0% +a lot of people who actually created +those essays weren't necessarily artists + + align:start position:0% +those essays weren't necessarily artists + + + align:start position:0% +those essays weren't necessarily artists +and that's not to say that you didn't + + align:start position:0% +and that's not to say that you didn't + + + align:start position:0% +and that's not to say that you didn't +have diagrams and magazines like that + + align:start position:0% +have diagrams and magazines like that + + + align:start position:0% +have diagrams and magazines like that +but it was expensive this is before + + align:start position:0% +but it was expensive this is before + + + align:start position:0% +but it was expensive this is before +desktop publishing so people just got + + align:start position:0% +desktop publishing so people just got + + + align:start position:0% +desktop publishing so people just got +really really used to describing things + + align:start position:0% +really really used to describing things + + + align:start position:0% +really really used to describing things +in prose describing core game mechanics + + align:start position:0% +in prose describing core game mechanics + + + align:start position:0% +in prose describing core game mechanics +in prose not even point form more for + + align:start position:0% +in prose not even point form more for + + + align:start position:0% +in prose not even point form more for +the points so so there were basically + + align:start position:0% +the points so so there were basically + + + align:start position:0% +the points so so there were basically +two suggestions that he has on how to + + align:start position:0% +two suggestions that he has on how to + + + align:start position:0% +two suggestions that he has on how to +deal with the whole three player problem + + align:start position:0% +deal with the whole three player problem + + + align:start position:0% +deal with the whole three player problem +you know that like the actually before I + + align:start position:0% +you know that like the actually before I + + + align:start position:0% +you know that like the actually before I +get into this so you guys don't get + + align:start position:0% +get into this so you guys don't get + + + align:start position:0% +get into this so you guys don't get +anyone that I quickly sum up what's the + + align:start position:0% +anyone that I quickly sum up what's the + + + align:start position:0% +anyone that I quickly sum up what's the +main problem with having this design any + + align:start position:0% +main problem with having this design any + + + align:start position:0% +main problem with having this design any +important three players + + align:start position:0% + + + + align:start position:0% + +I mean where do eclipse or go I began + + align:start position:0% +I mean where do eclipse or go I began + + + align:start position:0% +I mean where do eclipse or go I began +themselves back + + align:start position:0% + + + + align:start position:0% + +okay so that's most of all positive set + + align:start position:0% +okay so that's most of all positive set + + + align:start position:0% +okay so that's most of all positive set +of rules that's one kind of strategy + + align:start position:0% +of rules that's one kind of strategy + + + align:start position:0% +of rules that's one kind of strategy +which encourages you to basically not + + align:start position:0% +which encourages you to basically not + + + align:start position:0% +which encourages you to basically not +interact with anybody else and then when + + align:start position:0% +interact with anybody else and then when + + + align:start position:0% +interact with anybody else and then when +you get it right I was gonna say there + + align:start position:0% +you get it right I was gonna say there + + + align:start position:0% +you get it right I was gonna say there +is this is where it's just one player + + align:start position:0% +is this is where it's just one player + + + align:start position:0% +is this is where it's just one player +chooses what's the other place wins + + align:start position:0% +chooses what's the other place wins + + + align:start position:0% +chooses what's the other place wins +mm-hmm so so I believe keep making what + + align:start position:0% +mm-hmm so so I believe keep making what + + + align:start position:0% +mm-hmm so so I believe keep making what +the name that was given to do that you + + align:start position:0% +the name that was given to do that you + + + align:start position:0% +the name that was given to do that you +may not be in a position to win the game + + align:start position:0% +may not be in a position to win the game + + + align:start position:0% +may not be in a position to win the game +but a game with only three players you + + align:start position:0% +but a game with only three players you + + + align:start position:0% +but a game with only three players you +might have enough influence to basically + + align:start position:0% +might have enough influence to basically + + + align:start position:0% +might have enough influence to basically +say I don't like you that's why you are + + align:start position:0% +say I don't like you that's why you are + + + align:start position:0% +say I don't like you that's why you are +not gonna win that's what the other + + align:start position:0% +not gonna win that's what the other + + + align:start position:0% +not gonna win that's what the other +person's got away even though I right + + align:start position:0% +person's got away even though I right + + + align:start position:0% +person's got away even though I right +now work you more more sort of like + + align:start position:0% +now work you more more sort of like + + + align:start position:0% +now work you more more sort of like +subtle problems that you described + + align:start position:0% +subtle problems that you described + + + align:start position:0% +subtle problems that you described +remember Nia + + align:start position:0% + + + + align:start position:0% + +one with politics of two people the + + align:start position:0% +one with politics of two people the + + + align:start position:0% +one with politics of two people the +other campaign uh Rock yeah he brought + + align:start position:0% +other campaign uh Rock yeah he brought + + + align:start position:0% +other campaign uh Rock yeah he brought +it up this that's come up in a reading + + align:start position:0% +it up this that's come up in a reading + + + align:start position:0% +it up this that's come up in a reading +yeah it's not necessary described as a + + align:start position:0% +yeah it's not necessary described as a + + + align:start position:0% +yeah it's not necessary described as a +problem but something that does happen + + align:start position:0% +problem but something that does happen + + + align:start position:0% +problem but something that does happen +and happens often so you either take + + align:start position:0% +and happens often so you either take + + + align:start position:0% +and happens often so you either take +advantage of it or as a designer or you + + align:start position:0% +advantage of it or as a designer or you + + + align:start position:0% +advantage of it or as a designer or you +or you own all your game separates + + align:start position:0% +or you own all your game separates + + + align:start position:0% +or you own all your game separates +because you hadn't thought about it + + align:start position:0% +because you hadn't thought about it + + + align:start position:0% +because you hadn't thought about it +right this whole idea of somebody's it + + align:start position:0% +right this whole idea of somebody's it + + + align:start position:0% +right this whole idea of somebody's it +elite and two people probably want to do + + align:start position:0% +elite and two people probably want to do + + + align:start position:0% +elite and two people probably want to do +a temporary alliance that very nice try + + align:start position:0% +a temporary alliance that very nice try + + + align:start position:0% +a temporary alliance that very nice try +to take down with that way those are + + align:start position:0% +to take down with that way those are + + + align:start position:0% +to take down with that way those are +called sanitizing and I'm actually + + align:start position:0% +called sanitizing and I'm actually + + + align:start position:0% +called sanitizing and I'm actually +forgetting what that means + + align:start position:0% + + + + align:start position:0% + +oh yeah pretending that you are light + + align:start position:0% +oh yeah pretending that you are light + + + align:start position:0% +oh yeah pretending that you are light +light like all your trying like + + align:start position:0% +light like all your trying like + + + align:start position:0% +light like all your trying like +bordering on lying right you know honest + + align:start position:0% +bordering on lying right you know honest + + + align:start position:0% +bordering on lying right you know honest +like now I'm not gonna win the game in + + align:start position:0% +like now I'm not gonna win the game in + + + align:start position:0% +like now I'm not gonna win the game in +the next turn + + align:start position:0% +the next turn + + + align:start position:0% +the next turn +don't worry about me new leaf and used + + align:start position:0% +don't worry about me new leaf and used + + + align:start position:0% +don't worry about me new leaf and used +area you know and that that sort of + + align:start position:0% +area you know and that that sort of + + + align:start position:0% +area you know and that that sort of +light Sun of defeat where where you have + + align:start position:0% +light Sun of defeat where where you have + + + align:start position:0% +light Sun of defeat where where you have +to like actively conceal the fact that + + align:start position:0% +to like actively conceal the fact that + + + align:start position:0% +to like actively conceal the fact that +you are not Italy then there are some + + align:start position:0% +you are not Italy then there are some + + + align:start position:0% +you are not Italy then there are some +games that say all right here are some + + align:start position:0% +games that say all right here are some + + + align:start position:0% +games that say all right here are some +ways that you can do that I'm not sure + + align:start position:0% + + + + align:start position:0% + +yeah yeah so crunches a game about being + + align:start position:0% +yeah yeah so crunches a game about being + + + align:start position:0% +yeah yeah so crunches a game about being +a banker during I'm trying to fill up + + align:start position:0% +a banker during I'm trying to fill up + + + align:start position:0% +a banker during I'm trying to fill up +your golden parachute before the market + + align:start position:0% +your golden parachute before the market + + + align:start position:0% +your golden parachute before the market +crashes and you are encouraged to play + + align:start position:0% +crashes and you are encouraged to play + + + align:start position:0% +crashes and you are encouraged to play +the game and it's releases so that you + + align:start position:0% +the game and it's releases so that you + + + align:start position:0% +the game and it's releases so that you +can actually actively hide parts and and + + align:start position:0% +can actually actively hide parts and and + + + align:start position:0% +can actually actively hide parts and and +the idea is that at the end of the game + + align:start position:0% +the idea is that at the end of the game + + + align:start position:0% +the idea is that at the end of the game +the amount of money that you've managed + + align:start position:0% +the amount of money that you've managed + + + align:start position:0% +the amount of money that you've managed +to sequester for your own personal use + + align:start position:0% +to sequester for your own personal use + + + align:start position:0% +to sequester for your own personal use +including any cards that you have habit + + align:start position:0% +including any cards that you have habit + + + align:start position:0% +including any cards that you have habit +of hitting on off on yourself will we do + + align:start position:0% +of hitting on off on yourself will we do + + + align:start position:0% +of hitting on off on yourself will we do +the game it's not about keeping your + + align:start position:0% +the game it's not about keeping your + + + align:start position:0% +the game it's not about keeping your +bank system at all it's all about + + align:start position:0% +bank system at all it's all about + + + align:start position:0% +bank system at all it's all about +leaving with the one with with largest + + align:start position:0% +leaving with the one with with largest + + + align:start position:0% +leaving with the one with with largest +personal fortune so it's this rice + + align:start position:0% +personal fortune so it's this rice + + + align:start position:0% +personal fortune so it's this rice +satirical game but that one actively + + align:start position:0% +satirical game but that one actively + + + align:start position:0% +satirical game but that one actively +encourages you to conceal how well + + align:start position:0% +encourages you to conceal how well + + + align:start position:0% +encourages you to conceal how well +they're performing now it's to play a + + align:start position:0% +they're performing now it's to play a + + + align:start position:0% +they're performing now it's to play a +game it's not like a like a trip to + + align:start position:0% +game it's not like a like a trip to + + + align:start position:0% +game it's not like a like a trip to +anything so that you are also well aware + + align:start position:0% +anything so that you are also well aware + + + align:start position:0% +anything so that you are also well aware +that your foot is doing the same sort of + + align:start position:0% +that your foot is doing the same sort of + + + align:start position:0% +that your foot is doing the same sort of +thing you're just trying to do the best + + align:start position:0% +thing you're just trying to do the best + + + align:start position:0% +thing you're just trying to do the best +that you can in accumulating as much + + align:start position:0% +that you can in accumulating as much + + + align:start position:0% +that you can in accumulating as much +cash as possible + + align:start position:0% +cash as possible + + + align:start position:0% +cash as possible +because that that's what's gonna win you + + align:start position:0% +because that that's what's gonna win you + + + align:start position:0% +because that that's what's gonna win you +again but in the situation with three + + align:start position:0% +again but in the situation with three + + + align:start position:0% +again but in the situation with three +players you can imagine a situation + + align:start position:0% +players you can imagine a situation + + + align:start position:0% +players you can imagine a situation +where someone could figure out that + + align:start position:0% +where someone could figure out that + + + align:start position:0% +where someone could figure out that +you're in the lead and that person can + + align:start position:0% +you're in the lead and that person can + + + align:start position:0% +you're in the lead and that person can +catch up and you know what can you do + + align:start position:0% +catch up and you know what can you do + + + align:start position:0% +catch up and you know what can you do +like pass cards to the to the player + + align:start position:0% +like pass cards to the to the player + + + align:start position:0% +like pass cards to the to the player +that you want to win you know for + + align:start position:0% +that you want to win you know for + + + align:start position:0% +that you want to win you know for +instance and that might be tough because + + align:start position:0% +instance and that might be tough because + + + align:start position:0% +instance and that might be tough because +someone might not be able to interfere + + align:start position:0% +someone might not be able to interfere + + + align:start position:0% +someone might not be able to interfere +with the process + + align:start position:0% + + + + align:start position:0% + +there's like you're like into your a + + align:start position:0% +there's like you're like into your a + + + align:start position:0% +there's like you're like into your a +like politician in sunlight and some + + align:start position:0% +like politician in sunlight and some + + + align:start position:0% +like politician in sunlight and some +Latin American Banana Republic their + + align:start position:0% +Latin American Banana Republic their + + + align:start position:0% +Latin American Banana Republic their +goal was to embezzle as much warning + + align:start position:0% +goal was to embezzle as much warning + + + align:start position:0% +goal was to embezzle as much warning +money as possible and one of the things + + align:start position:0% +money as possible and one of the things + + + align:start position:0% +money as possible and one of the things +that the the Ghana for daily drama + + align:start position:0% +that the the Ghana for daily drama + + + align:start position:0% +that the the Ghana for daily drama +eacher is variable and like only the + + align:start position:0% +eacher is variable and like only the + + + align:start position:0% +eacher is variable and like only the +president really knows me and so like + + align:start position:0% +president really knows me and so like + + + align:start position:0% +president really knows me and so like +that's other parts lien is that + + align:start position:0% +that's other parts lien is that + + + align:start position:0% +that's other parts lien is that +sometimes like the president will draw + + align:start position:0% +sometimes like the president will draw + + + align:start position:0% +sometimes like the president will draw +very much where's my like cause even + + align:start position:0% +very much where's my like cause even + + + align:start position:0% +very much where's my like cause even +logic cool against it because they think + + align:start position:0% +logic cool against it because they think + + + align:start position:0% +logic cool against it because they think +he's lying and taking a lot for himself + + align:start position:0% +he's lying and taking a lot for himself + + + align:start position:0% +he's lying and taking a lot for himself +and they're scared and waiting for a + + align:start position:0% +and they're scared and waiting for a + + + align:start position:0% +and they're scared and waiting for a +reason like yeah basically there's so + + align:start position:0% +reason like yeah basically there's so + + + align:start position:0% +reason like yeah basically there's so +much uncertainty about how much like + + align:start position:0% +much uncertainty about how much like + + + align:start position:0% +much uncertainty about how much like +it's not computable how much people have + + align:start position:0% +it's not computable how much people have + + + align:start position:0% +it's not computable how much people have +in their head with a J right there yeah + + align:start position:0% +in their head with a J right there yeah + + + align:start position:0% +in their head with a J right there yeah +so because need right it sort of plays + + align:start position:0% +so because need right it sort of plays + + + align:start position:0% +so because need right it sort of plays +around around with this idea that you + + align:start position:0% +around around with this idea that you + + + align:start position:0% +around around with this idea that you +know you have this dictator that's + + align:start position:0% +know you have this dictator that's + + + align:start position:0% +know you have this dictator that's +that's seems to be amassing a large + + align:start position:0% +that's seems to be amassing a large + + + align:start position:0% +that's seems to be amassing a large +personal fortune whether or not the + + align:start position:0% +personal fortune whether or not the + + + align:start position:0% +personal fortune whether or not the +dictator that that is actually being + + align:start position:0% +dictator that that is actually being + + + align:start position:0% +dictator that that is actually being +successful in a process of amassing a + + align:start position:0% +successful in a process of amassing a + + + align:start position:0% +successful in a process of amassing a +bit large personal fortune it is that + + align:start position:0% +bit large personal fortune it is that + + + align:start position:0% +bit large personal fortune it is that +that game is designed to paint a giant + + align:start position:0% +that game is designed to paint a giant + + + align:start position:0% +that game is designed to paint a giant +target may be another game here called + + align:start position:0% +target may be another game here called + + + align:start position:0% +target may be another game here called +king of Tokyo which is basically giant + + align:start position:0% +king of Tokyo which is basically giant + + + align:start position:0% +king of Tokyo which is basically giant +monsters trying to take over the bait + + align:start position:0% +monsters trying to take over the bait + + + align:start position:0% +monsters trying to take over the bait +took away every single generic giant + + align:start position:0% +took away every single generic giant + + + align:start position:0% +took away every single generic giant +robot giant dinosaur octopus singing + + align:start position:0% +robot giant dinosaur octopus singing + + + align:start position:0% +robot giant dinosaur octopus singing +make a dinosaur and and whoever happens + + align:start position:0% +make a dinosaur and and whoever happens + + + align:start position:0% +make a dinosaur and and whoever happens +to be a king of the hill at that point + + align:start position:0% +to be a king of the hill at that point + + + align:start position:0% +to be a king of the hill at that point +has a giant target on not that many game + + align:start position:0% +has a giant target on not that many game + + + align:start position:0% +has a giant target on not that many game +mechanics all support that that's what + + align:start position:0% +mechanics all support that that's what + + + align:start position:0% +mechanics all support that that's what +the games all about so so those are some + + align:start position:0% +the games all about so so those are some + + + align:start position:0% +the games all about so so those are some +of the problems and he and he proposes + + align:start position:0% +of the problems and he and he proposes + + + align:start position:0% +of the problems and he and he proposes +two solutions it's not necessarily in + + align:start position:0% +two solutions it's not necessarily in + + + align:start position:0% +two solutions it's not necessarily in +the only two solutions but these are the + + align:start position:0% +the only two solutions but these are the + + + align:start position:0% +the only two solutions but these are the +ones that now occurs to him and + + align:start position:0% +ones that now occurs to him and + + + align:start position:0% +ones that now occurs to him and +particularly in the wargaming since this + + align:start position:0% +particularly in the wargaming since this + + + align:start position:0% +particularly in the wargaming since this +might work and there are actually kind + + align:start position:0% +might work and there are actually kind + + + align:start position:0% +might work and there are actually kind +of opposite ends of the spectrum + + align:start position:0% +of opposite ends of the spectrum + + + align:start position:0% +of opposite ends of the spectrum +anyone remember one of those two + + align:start position:0% +anyone remember one of those two + + + align:start position:0% +anyone remember one of those two +solutions + + align:start position:0% +solutions + + + align:start position:0% +solutions +equilibrium if one person gets ahead + + align:start position:0% + + + + align:start position:0% + +they cannot be significant + + align:start position:0% + + + + align:start position:0% + +I think equilibrium was the opposite of + + align:start position:0% +I think equilibrium was the opposite of + + + align:start position:0% +I think equilibrium was the opposite of +that yeah so so you've actually just + + align:start position:0% +that yeah so so you've actually just + + + align:start position:0% +that yeah so so you've actually just +completed two answers into one which is + + align:start position:0% +completed two answers into one which is + + + align:start position:0% +completed two answers into one which is +good so so the equilibrium if I recall + + align:start position:0% +good so so the equilibrium if I recall + + + align:start position:0% +good so so the equilibrium if I recall +correctly from the reading the + + align:start position:0% +correctly from the reading the + + + align:start position:0% +correctly from the reading the +equilibria method was or design goal + + align:start position:0% +equilibria method was or design goal + + + align:start position:0% +equilibria method was or design goal +that seems like if you manage to in sign + + align:start position:0% +that seems like if you manage to in sign + + + align:start position:0% +that seems like if you manage to in sign +that is taking advantage of things like + + align:start position:0% +that is taking advantage of things like + + + align:start position:0% +that is taking advantage of things like +the balance of power theory which is if + + align:start position:0% +the balance of power theory which is if + + + align:start position:0% +the balance of power theory which is if +there is a person who's clearly ahead + + align:start position:0% +there is a person who's clearly ahead + + + align:start position:0% +there is a person who's clearly ahead +everybody else who is weaker is probably + + align:start position:0% +everybody else who is weaker is probably + + + align:start position:0% +everybody else who is weaker is probably +going to band up and take you down and + + align:start position:0% +going to band up and take you down and + + + align:start position:0% +going to band up and take you down and +if you balance the game in a certain way + + align:start position:0% +if you balance the game in a certain way + + + align:start position:0% +if you balance the game in a certain way +you give that the tools to do that and + + align:start position:0% +you give that the tools to do that and + + + align:start position:0% +you give that the tools to do that and +does take anyone who seems to be ahead + + align:start position:0% +does take anyone who seems to be ahead + + + align:start position:0% +does take anyone who seems to be ahead +back to a sort of equal power level + + align:start position:0% +back to a sort of equal power level + + + align:start position:0% +back to a sort of equal power level +that's a bad balance of power theory is + + align:start position:0% +that's a bad balance of power theory is + + + align:start position:0% +that's a bad balance of power theory is +something for political science I've + + align:start position:0% +something for political science I've + + + align:start position:0% +something for political science I've +only heard about it in passing if + + align:start position:0% +only heard about it in passing if + + + align:start position:0% +only heard about it in passing if +there's anybody here who's taking + + align:start position:0% +there's anybody here who's taking + + + align:start position:0% +there's anybody here who's taking +political science classes you can tell + + align:start position:0% +political science classes you can tell + + + align:start position:0% +political science classes you can tell +me ever getting this right around the + + align:start position:0% +me ever getting this right around the + + + align:start position:0% +me ever getting this right around the +whole place is not a far-fetched idea + + align:start position:0% +whole place is not a far-fetched idea + + + align:start position:0% +whole place is not a far-fetched idea +right you know you got if you've got a + + align:start position:0% +right you know you got if you've got a + + + align:start position:0% +right you know you got if you've got a +powerful nation other nations were + + align:start position:0% +powerful nation other nations were + + + align:start position:0% +powerful nation other nations were +bothering them that that powerful nation + + align:start position:0% +bothering them that that powerful nation + + + align:start position:0% +bothering them that that powerful nation +are likely to either team up with the + + align:start position:0% +are likely to either team up with the + + + align:start position:0% +are likely to either team up with the +powerful nation are more likely to + + align:start position:0% +powerful nation are more likely to + + + align:start position:0% +powerful nation are more likely to +perish together even though they may not + + align:start position:0% +perish together even though they may not + + + align:start position:0% +perish together even though they may not +be ideologically later ideologically + + align:start position:0% +be ideologically later ideologically + + + align:start position:0% +be ideologically later ideologically +with against that tell powerful nation + + align:start position:0% +with against that tell powerful nation + + + align:start position:0% +with against that tell powerful nation +yeah so in same thing with those four + + align:start position:0% +yeah so in same thing with those four + + + align:start position:0% +yeah so in same thing with those four +players so basically comes down to + + align:start position:0% +players so basically comes down to + + + align:start position:0% +players so basically comes down to +giving everybody the tool to take down + + align:start position:0% +giving everybody the tool to take down + + + align:start position:0% +giving everybody the tool to take down +the leader a notch and man does restore + + align:start position:0% +the leader a notch and man does restore + + + align:start position:0% +the leader a notch and man does restore +everything to a sort of equilibrium + + align:start position:0% +everything to a sort of equilibrium + + + align:start position:0% +everything to a sort of equilibrium +state and then yours your your success + + align:start position:0% +state and then yours your your success + + + align:start position:0% +state and then yours your your success +criteria for the game probably isn't + + align:start position:0% +criteria for the game probably isn't + + + align:start position:0% +criteria for the game probably isn't +who's going to to gain such a massively + + align:start position:0% +who's going to to gain such a massively + + + align:start position:0% +who's going to to gain such a massively +because the game is deliberately + + align:start position:0% +because the game is deliberately + + + align:start position:0% +because the game is deliberately +designed to restore everything to + + align:start position:0% +designed to restore everything to + + + align:start position:0% +designed to restore everything to +equilibria you have you need to have + + align:start position:0% +equilibria you have you need to have + + + align:start position:0% +equilibria you have you need to have +some other kinds of success criteria + + align:start position:0% +some other kinds of success criteria + + + align:start position:0% +some other kinds of success criteria +maybe the game is kind limited for + + align:start position:0% +maybe the game is kind limited for + + + align:start position:0% +maybe the game is kind limited for +instance maybe the game is different + + align:start position:0% +instance maybe the game is different + + + align:start position:0% +instance maybe the game is different +goals for each player or something so + + align:start position:0% +goals for each player or something so + + + align:start position:0% +goals for each player or something so +even though your power levels are about + + align:start position:0% +even though your power levels are about + + + align:start position:0% +even though your power levels are about +the same you might be a + + align:start position:0% +the same you might be a + + + align:start position:0% +the same you might be a +to accomplish of get victory points on + + align:start position:0% +to accomplish of get victory points on + + + align:start position:0% +to accomplish of get victory points on +something faster than others what about + + align:start position:0% +something faster than others what about + + + align:start position:0% +something faster than others what about +the the alternative which you internet + + align:start position:0% +the the alternative which you internet + + + align:start position:0% +the the alternative which you internet +which was basically making it difficult + + align:start position:0% +which was basically making it difficult + + + align:start position:0% +which was basically making it difficult +to take down the person who's in the + + align:start position:0% +to take down the person who's in the + + + align:start position:0% +to take down the person who's in the +lead + + align:start position:0% +lead + + + align:start position:0% +lead +once they already in the lead so that + + align:start position:0% +once they already in the lead so that + + + align:start position:0% +once they already in the lead so that +was like he had one very specific + + align:start position:0% +was like he had one very specific + + + align:start position:0% +was like he had one very specific +implementation of this or one one + + align:start position:0% +implementation of this or one one + + + align:start position:0% +implementation of this or one one +particular rule of thumb on how how how + + align:start position:0% +particular rule of thumb on how how how + + + align:start position:0% +particular rule of thumb on how how how +how effect it must have president he'd + + align:start position:0% +how effect it must have president he'd + + + align:start position:0% +how effect it must have president he'd +be in order to prevent the key making + + align:start position:0% +be in order to prevent the key making + + + align:start position:0% +be in order to prevent the key making +and assign my gaining and + + align:start position:0% + + + + align:start position:0% + +well the basic idea is that you must be + + align:start position:0% +well the basic idea is that you must be + + + align:start position:0% +well the basic idea is that you must be +able to do it in a trip and turns in a + + align:start position:0% +able to do it in a trip and turns in a + + + align:start position:0% +able to do it in a trip and turns in a +single turn you should be able to if you + + align:start position:0% +single turn you should be able to if you + + + align:start position:0% +single turn you should be able to if you +are in the lead you should be able to + + align:start position:0% +are in the lead you should be able to + + + align:start position:0% +are in the lead you should be able to +complete the game and win the game as an + + align:start position:0% +complete the game and win the game as an + + + align:start position:0% +complete the game and win the game as an +alternate I'm not so sure whether I + + align:start position:0% +alternate I'm not so sure whether I + + + align:start position:0% +alternate I'm not so sure whether I +agree with that but and I don't think he + + align:start position:0% +agree with that but and I don't think he + + + align:start position:0% +agree with that but and I don't think he +means win it on your turn I think it + + align:start position:0% +means win it on your turn I think it + + + align:start position:0% +means win it on your turn I think it +means like in a round of people like by + + align:start position:0% +means like in a round of people like by + + + align:start position:0% +means like in a round of people like by +the time if you are in the lead in the + + align:start position:0% +the time if you are in the lead in the + + + align:start position:0% +the time if you are in the lead in the +game you should be able to do something + + align:start position:0% +game you should be able to do something + + + align:start position:0% +game you should be able to do something +that to cement that lead so that within + + align:start position:0% +that to cement that lead so that within + + + align:start position:0% +that to cement that lead so that within +that turn no one's gonna be able to do + + align:start position:0% +that turn no one's gonna be able to do + + + align:start position:0% +that turn no one's gonna be able to do +anything about energy before them okay + + align:start position:0% +anything about energy before them okay + + + align:start position:0% +anything about energy before them okay +this is a missus four games where there + + align:start position:0% +this is a missus four games where there + + + align:start position:0% +this is a missus four games where there +is like a clear win condition that's + + align:start position:0% +is like a clear win condition that's + + + align:start position:0% +is like a clear win condition that's +based on overpowering your opponents + + align:start position:0% +based on overpowering your opponents + + + align:start position:0% +based on overpowering your opponents +then you don't want to have the + + align:start position:0% +then you don't want to have the + + + align:start position:0% +then you don't want to have the +situation where yeah I'm in the lead but + + align:start position:0% +situation where yeah I'm in the lead but + + + align:start position:0% +situation where yeah I'm in the lead but +I'm still but everybody else still has + + align:start position:0% +I'm still but everybody else still has + + + align:start position:0% +I'm still but everybody else still has +enough time to to take me down to the + + align:start position:0% +enough time to to take me down to the + + + align:start position:0% +enough time to to take me down to the +point that somebody else can then catch + + align:start position:0% +point that somebody else can then catch + + + align:start position:0% +point that somebody else can then catch +up and be in the lead because that + + align:start position:0% +up and be in the lead because that + + + align:start position:0% +up and be in the lead because that +basically means that you that the first + + align:start position:0% +basically means that you that the first + + + align:start position:0% +basically means that you that the first +person to get in a league will probably + + align:start position:0% +person to get in a league will probably + + + align:start position:0% +person to get in a league will probably +use and that that's that's that sad but + + align:start position:0% +use and that that's that's that sad but + + + align:start position:0% +use and that that's that's that sad but +we've seen that in certain computer + + align:start position:0% +we've seen that in certain computer + + + align:start position:0% +we've seen that in certain computer +games we've seen games where you know + + align:start position:0% +games we've seen games where you know + + + align:start position:0% +games we've seen games where you know +whoever who's in the lead has giant + + align:start position:0% +whoever who's in the lead has giant + + + align:start position:0% +whoever who's in the lead has giant +target painted on their back and you + + align:start position:0% +target painted on their back and you + + + align:start position:0% +target painted on their back and you +know you're expected to be taken down if + + align:start position:0% +know you're expected to be taken down if + + + align:start position:0% +know you're expected to be taken down if +you're the first one in the lead you are + + align:start position:0% +you're the first one in the lead you are + + + align:start position:0% +you're the first one in the lead you are +probably going to get hit but that now + + align:start position:0% +probably going to get hit but that now + + + align:start position:0% +probably going to get hit but that now +gives you enough time to be able to pull + + align:start position:0% +gives you enough time to be able to pull + + + align:start position:0% +gives you enough time to be able to pull +ahead so so that's that's closer to the + + align:start position:0% +ahead so so that's that's closer to the + + + align:start position:0% +ahead so so that's that's closer to the +equilibrium style right so I think I + + align:start position:0% +equilibrium style right so I think I + + + align:start position:0% +equilibrium style right so I think I +heard someone give me Mario Kart in the + + align:start position:0% +heard someone give me Mario Kart in the + + + align:start position:0% +heard someone give me Mario Kart in the +obvious one you get increasingly + + align:start position:0% +obvious one you get increasingly + + + align:start position:0% +obvious one you get increasingly +powerful weapons in support of you and + + align:start position:0% +powerful weapons in support of you and + + + align:start position:0% +powerful weapons in support of you and +you get more useful things that's an + + align:start position:0% +you get more useful things that's an + + + align:start position:0% +you get more useful things that's an +example in this book here the rules of + + align:start position:0% +example in this book here the rules of + + + align:start position:0% +example in this book here the rules of +play this is this is the paperback + + align:start position:0% +play this is this is the paperback + + + align:start position:0% +play this is this is the paperback +version as a perfect Super Monkey Ball + + align:start position:0% +version as a perfect Super Monkey Ball + + + align:start position:0% +version as a perfect Super Monkey Ball +and basically all the weapons say + + align:start position:0% +and basically all the weapons say + + + align:start position:0% +and basically all the weapons say +storage so if you're number one you can + + align:start position:0% +storage so if you're number one you can + + + align:start position:0% +storage so if you're number one you can +only shoot for it that's nothing to + + align:start position:0% +only shoot for it that's nothing to + + + align:start position:0% +only shoot for it that's nothing to +shoot there's nobody ahead of you so + + align:start position:0% +shoot there's nobody ahead of you so + + + align:start position:0% +shoot there's nobody ahead of you so +it's not actually just that it's not a + + align:start position:0% +it's not actually just that it's not a + + + align:start position:0% +it's not actually just that it's not a +technical visit but it's not like a + + align:start position:0% +technical visit but it's not like a + + + align:start position:0% +technical visit but it's not like a +weapon that slows you down but you know + + align:start position:0% +weapon that slows you down but you know + + + align:start position:0% +weapon that slows you down but you know +it's + + align:start position:0% +it's + + + align:start position:0% +it's +it's a useless thing you get these + + align:start position:0% +it's a useless thing you get these + + + align:start position:0% +it's a useless thing you get these +power-ups that are useless so a lot of + + align:start position:0% +power-ups that are useless so a lot of + + + align:start position:0% +power-ups that are useless so a lot of +these feed into a different way of + + align:start position:0% +these feed into a different way of + + + align:start position:0% +these feed into a different way of +looking at games that is very formal + + align:start position:0% +looking at games that is very formal + + + align:start position:0% +looking at games that is very formal +very techie and one that you've probably + + align:start position:0% +very techie and one that you've probably + + + align:start position:0% +very techie and one that you've probably +heard of mentioned multiple times in + + align:start position:0% +heard of mentioned multiple times in + + + align:start position:0% +heard of mentioned multiple times in +this class at another time as well + + align:start position:0% +this class at another time as well + + + align:start position:0% +this class at another time as well +that's just feedback systems I'm not + + align:start position:0% +that's just feedback systems I'm not + + + align:start position:0% +that's just feedback systems I'm not +talking about you IP bag I'm talking + + align:start position:0% +talking about you IP bag I'm talking + + + align:start position:0% +talking about you IP bag I'm talking +about the event from the cybernetics + + align:start position:0% +about the event from the cybernetics + + + align:start position:0% +about the event from the cybernetics +sense anyone tears heard about + + align:start position:0% +sense anyone tears heard about + + + align:start position:0% +sense anyone tears heard about +cybernetics from another class yeah yeah + + align:start position:0% +cybernetics from another class yeah yeah + + + align:start position:0% +cybernetics from another class yeah yeah +yeah yeah I definitely brought it up + + align:start position:0% +yeah yeah I definitely brought it up + + + align:start position:0% +yeah yeah I definitely brought it up +yeah or you had a feedback systems back + + align:start position:0% +yeah or you had a feedback systems back + + + align:start position:0% +yeah or you had a feedback systems back +with you that's it's a positive and + + align:start position:0% +with you that's it's a positive and + + + align:start position:0% +with you that's it's a positive and +negative deal if you win you either will + + align:start position:0% +negative deal if you win you either will + + + align:start position:0% +negative deal if you win you either will +start with even more or you're losing + + align:start position:0% +start with even more or you're losing + + + align:start position:0% +start with even more or you're losing +you start to catch up right so that's + + align:start position:0% +you start to catch up right so that's + + + align:start position:0% +you start to catch up right so that's +the whole basic idea of cybernetics is + + align:start position:0% +the whole basic idea of cybernetics is + + + align:start position:0% +the whole basic idea of cybernetics is +based on sort of automated control you + + align:start position:0% +based on sort of automated control you + + + align:start position:0% +based on sort of automated control you +know you've got you create systems + + align:start position:0% +know you've got you create systems + + + align:start position:0% +know you've got you create systems +mechanical or electronic or with a set + + align:start position:0% +mechanical or electronic or with a set + + + align:start position:0% +mechanical or electronic or with a set +of rules that basically going to either + + align:start position:0% +of rules that basically going to either + + + align:start position:0% +of rules that basically going to either +accelerate or sort of this off slow off + + align:start position:0% +accelerate or sort of this off slow off + + + align:start position:0% +accelerate or sort of this off slow off +slow ball the the performance of the + + align:start position:0% +slow ball the the performance of the + + + align:start position:0% +slow ball the the performance of the +system or bring it back to equilibrium + + align:start position:0% +system or bring it back to equilibrium + + + align:start position:0% +system or bring it back to equilibrium +if this sounds very familiar to + + align:start position:0% +if this sounds very familiar to + + + align:start position:0% +if this sounds very familiar to +something and Mickey or Yee or something + + align:start position:0% +something and Mickey or Yee or something + + + align:start position:0% +something and Mickey or Yee or something +that's that's completely expected thing + + align:start position:0% +that's that's completely expected thing + + + align:start position:0% +that's that's completely expected thing +this all came of that + + align:start position:0% +this all came of that + + + align:start position:0% +this all came of that +so the basic model is then you have some + + align:start position:0% +so the basic model is then you have some + + + align:start position:0% +so the basic model is then you have some +sort of sensor something that detects an + + align:start position:0% +sort of sensor something that detects an + + + align:start position:0% +sort of sensor something that detects an +environmental change it could be + + align:start position:0% +environmental change it could be + + + align:start position:0% +environmental change it could be +something that detects treat the stain + + align:start position:0% +something that detects treat the stain + + + align:start position:0% +something that detects treat the stain +of your game some way of telling you + + align:start position:0% +of your game some way of telling you + + + align:start position:0% +of your game some way of telling you +this is the current state that you're + + align:start position:0% +this is the current state that you're + + + align:start position:0% +this is the current state that you're +looking at that goes to a comparator + + align:start position:0% + + + + align:start position:0% + +a small space because it's longer work + + align:start position:0% +a small space because it's longer work + + + align:start position:0% +a small space because it's longer work +compared read before which performs some + + align:start position:0% +compared read before which performs some + + + align:start position:0% +compared read before which performs some +sort of logical assessment on the state + + align:start position:0% +sort of logical assessment on the state + + + align:start position:0% +sort of logical assessment on the state +of the system that you're looking at + + align:start position:0% +of the system that you're looking at + + + align:start position:0% +of the system that you're looking at +then are you going to an actuator which + + align:start position:0% +then are you going to an actuator which + + + align:start position:0% +then are you going to an actuator which +perform some sort of action and it's + + align:start position:0% +perform some sort of action and it's + + + align:start position:0% +perform some sort of action and it's +called feedback because this thing just + + align:start position:0% +called feedback because this thing just + + + align:start position:0% +called feedback because this thing just +keeps me depend right real life systems + + align:start position:0% +keeps me depend right real life systems + + + align:start position:0% +keeps me depend right real life systems +that do this like what some of the + + align:start position:0% +that do this like what some of the + + + align:start position:0% +that do this like what some of the +simplest real life systems that it is + + align:start position:0% +simplest real life systems that it is + + + align:start position:0% +simplest real life systems that it is +like electronically or mechanically + + align:start position:0% +like electronically or mechanically + + + align:start position:0% +like electronically or mechanically +without human knowledge without + + align:start position:0% +without human knowledge without + + + align:start position:0% +without human knowledge without +intervention washing machine washing + + align:start position:0% +intervention washing machine washing + + + align:start position:0% +intervention washing machine washing +machine never said that was that that's + + align:start position:0% +machine never said that was that that's + + + align:start position:0% +machine never said that was that that's +that way oh yeah yeah yeah that's true + + align:start position:0% +that way oh yeah yeah yeah that's true + + + align:start position:0% +that way oh yeah yeah yeah that's true +so so much that things get too hot + + align:start position:0% +so so much that things get too hot + + + align:start position:0% +so so much that things get too hot +turn on the cooling system you know shut + + align:start position:0% +turn on the cooling system you know shut + + + align:start position:0% +turn on the cooling system you know shut +off the heating system you see + + align:start position:0% + + + + align:start position:0% + +the sensor is you know whether the water + + align:start position:0% +the sensor is you know whether the water + + + align:start position:0% +the sensor is you know whether the water +is actually hit that hole you know in + + align:start position:0% +is actually hit that hole you know in + + + align:start position:0% +is actually hit that hole you know in +context + + align:start position:0% +context + + + align:start position:0% +context +I guess the sensor is the level of the + + align:start position:0% +I guess the sensor is the level of the + + + align:start position:0% +I guess the sensor is the level of the +water the comparator is at a height of + + align:start position:0% +water the comparator is at a height of + + + align:start position:0% +water the comparator is at a height of +the hole and then the activator is if + + align:start position:0% +the hole and then the activator is if + + + align:start position:0% +the hole and then the activator is if +it's at the right of the hole called a + + align:start position:0% +it's at the right of the hole called a + + + align:start position:0% +it's at the right of the hole called a +hole right so so it's actually just like + + align:start position:0% +hole right so so it's actually just like + + + align:start position:0% +hole right so so it's actually just like +physics is the entire system for you but + + align:start position:0% +physics is the entire system for you but + + + align:start position:0% +physics is the entire system for you but +it's been interior in a way to take a + + align:start position:0% +it's been interior in a way to take a + + + align:start position:0% +it's been interior in a way to take a +bunch of systems like autopilot Amy + + align:start position:0% +bunch of systems like autopilot Amy + + + align:start position:0% +bunch of systems like autopilot Amy +mm-hm this sort of keeping you on the + + align:start position:0% +mm-hm this sort of keeping you on the + + + align:start position:0% +mm-hm this sort of keeping you on the +path that you're supposed to be and it's + + align:start position:0% +path that you're supposed to be and it's + + + align:start position:0% +path that you're supposed to be and it's +always just doing my cute little + + align:start position:0% +always just doing my cute little + + + align:start position:0% +always just doing my cute little +Corrections majority of these things are + + align:start position:0% +Corrections majority of these things are + + + align:start position:0% +Corrections majority of these things are +real world applications of these + + align:start position:0% +real world applications of these + + + align:start position:0% +real world applications of these +negative feedback systems so the idea is + + align:start position:0% +negative feedback systems so the idea is + + + align:start position:0% +negative feedback systems so the idea is +that you know if there is a change in + + align:start position:0% +that you know if there is a change in + + + align:start position:0% +that you know if there is a change in +one direction pull it back you know if + + align:start position:0% +one direction pull it back you know if + + + align:start position:0% +one direction pull it back you know if +it goes if you had a direction pull it + + align:start position:0% +it goes if you had a direction pull it + + + align:start position:0% +it goes if you had a direction pull it +forward so that it so they're always + + align:start position:0% +forward so that it so they're always + + + align:start position:0% +forward so that it so they're always +sort of hovers around let's see these + + align:start position:0% +sort of hovers around let's see these + + + align:start position:0% +sort of hovers around let's see these +are like deliberately designed systems + + align:start position:0% +are like deliberately designed systems + + + align:start position:0% +are like deliberately designed systems +trying to do this all the time but there + + align:start position:0% +trying to do this all the time but there + + + align:start position:0% +trying to do this all the time but there +are a lot of real systems that do the + + align:start position:0% +are a lot of real systems that do the + + + align:start position:0% +are a lot of real systems that do the +opposite right stuff it snowballs for + + align:start position:0% +opposite right stuff it snowballs for + + + align:start position:0% +opposite right stuff it snowballs for +instance a snowball rolling down the + + align:start position:0% +instance a snowball rolling down the + + + align:start position:0% +instance a snowball rolling down the +hill and as it goes down it gets larger + + align:start position:0% +hill and as it goes down it gets larger + + + align:start position:0% +hill and as it goes down it gets larger +and it makes it slightly easier to + + align:start position:0% +and it makes it slightly easier to + + + align:start position:0% +and it makes it slightly easier to +continue whole thing I think surface + + align:start position:0% +continue whole thing I think surface + + + align:start position:0% +continue whole thing I think surface +area in contact to the snow actually + + align:start position:0% +area in contact to the snow actually + + + align:start position:0% +area in contact to the snow actually +decreases from the ratio 522 makes it + + align:start position:0% +decreases from the ratio 522 makes it + + + align:start position:0% +decreases from the ratio 522 makes it +easier to keep only it exact most well I + + align:start position:0% +easier to keep only it exact most well I + + + align:start position:0% +easier to keep only it exact most well I +guess another matter + + align:start position:0% +guess another matter + + + align:start position:0% +guess another matter +at the positive feedback system + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +that's for asteroids because fairly easy + + align:start position:0% +that's for asteroids because fairly easy + + + align:start position:0% +that's for asteroids because fairly easy +other small edits to you + + align:start position:0% + + + + align:start position:0% + +so there are two games that might that + + align:start position:0% +so there are two games that might that + + + align:start position:0% +so there are two games that might that +might be on what is orbital the Nintendo + + align:start position:0% +might be on what is orbital the Nintendo + + + align:start position:0% +might be on what is orbital the Nintendo +game what which can we suspect that + + align:start position:0% +game what which can we suspect that + + + align:start position:0% +game what which can we suspect that +sounds like category policies it's not + + align:start position:0% +sounds like category policies it's not + + + align:start position:0% +sounds like category policies it's not +like oh yeah let's see Osmos yeah I + + align:start position:0% +like oh yeah let's see Osmos yeah I + + + align:start position:0% +like oh yeah let's see Osmos yeah I +think that's a PC and portable device + + align:start position:0% +think that's a PC and portable device + + + align:start position:0% +think that's a PC and portable device +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +so that I suppose it's an interesting + + align:start position:0% +so that I suppose it's an interesting + + + align:start position:0% +so that I suppose it's an interesting +situation because yes the bigger you get + + align:start position:0% +situation because yes the bigger you get + + + align:start position:0% +situation because yes the bigger you get +the bigger you can get because the idea + + align:start position:0% +the bigger you can get because the idea + + + align:start position:0% +the bigger you can get because the idea +of osmosis by journalists I know people + + align:start position:0% +of osmosis by journalists I know people + + + align:start position:0% +of osmosis by journalists I know people +like long so a story I mean a little + + align:start position:0% +like long so a story I mean a little + + + align:start position:0% +like long so a story I mean a little +like law you can eat anything smaller + + align:start position:0% +like law you can eat anything smaller + + + align:start position:0% +like law you can eat anything smaller +than you and everything that you eat + + align:start position:0% +than you and everything that you eat + + + align:start position:0% +than you and everything that you eat +makes you bigger so you can eat even + + align:start position:0% +makes you bigger so you can eat even + + + align:start position:0% +makes you bigger so you can eat even +bigger things but actually makes it more + + align:start position:0% +bigger things but actually makes it more + + + align:start position:0% +bigger things but actually makes it more +difficult for you to navigate because + + align:start position:0% +difficult for you to navigate because + + + align:start position:0% +difficult for you to navigate because +you're more massive now so you actually + + align:start position:0% +you're more massive now so you actually + + + align:start position:0% +you're more massive now so you actually +had both negative and positive loops + + align:start position:0% +had both negative and positive loops + + + align:start position:0% +had both negative and positive loops +going on at once bumps + + align:start position:0% + + + + align:start position:0% + +it makes other things explode well + + align:start position:0% +it makes other things explode well + + + align:start position:0% +it makes other things explode well +there's that they also know so like like + + align:start position:0% +there's that they also know so like like + + + align:start position:0% +there's that they also know so like like +like that you're using an atomic bomb to + + align:start position:0% +like that you're using an atomic bomb to + + + align:start position:0% +like that you're using an atomic bomb to +set off the hydrogen bomb it's something + + align:start position:0% +set off the hydrogen bomb it's something + + + align:start position:0% +set off the hydrogen bomb it's something +okay yeah yeah you can sort of positive + + align:start position:0% +okay yeah yeah you can sort of positive + + + align:start position:0% +okay yeah yeah you can sort of positive +feedback often happens in military + + align:start position:0% +feedback often happens in military + + + align:start position:0% +feedback often happens in military +conflict right you know if you've got + + align:start position:0% +conflict right you know if you've got + + + align:start position:0% +conflict right you know if you've got +overwhelming if you've got overwhelming + + align:start position:0% +overwhelming if you've got overwhelming + + + align:start position:0% +overwhelming if you've got overwhelming +forces and I'll being every engagement + + align:start position:0% +forces and I'll being every engagement + + + align:start position:0% +forces and I'll being every engagement +just mix though makes the ratio if + + align:start position:0% +just mix though makes the ratio if + + + align:start position:0% +just mix though makes the ratio if +everything goes according to military + + align:start position:0% +everything goes according to military + + + align:start position:0% +everything goes according to military +doctrine every engagement is going to + + align:start position:0% +doctrine every engagement is going to + + + align:start position:0% +doctrine every engagement is going to +give you a yet greater advantage thirty + + align:start position:0% +give you a yet greater advantage thirty + + + align:start position:0% +give you a yet greater advantage thirty +so the way how this has been applied in + + align:start position:0% +so the way how this has been applied in + + + align:start position:0% +so the way how this has been applied in +games is you know just just to make it + + align:start position:0% +games is you know just just to make it + + + align:start position:0% +games is you know just just to make it +literal you have a state some sort of + + align:start position:0% +literal you have a state some sort of + + + align:start position:0% +literal you have a state some sort of +state of the game am I getting this + + align:start position:0% +state of the game am I getting this + + + align:start position:0% +state of the game am I getting this +right yeah you have to stay up the game + + align:start position:0% +right yeah you have to stay up the game + + + align:start position:0% +right yeah you have to stay up the game +you have this let me just make you make + + align:start position:0% +you have this let me just make you make + + + align:start position:0% +you have this let me just make you make +sure I got this perfectly right here we + + align:start position:0% +sure I got this perfectly right here we + + + align:start position:0% +sure I got this perfectly right here we +go you had some sort of scoring function + + align:start position:0% +go you had some sort of scoring function + + + align:start position:0% +go you had some sort of scoring function +it doesn't have to be the literal score + + align:start position:0% +it doesn't have to be the literal score + + + align:start position:0% +it doesn't have to be the literal score +but it has to be some way of assessing + + align:start position:0% +but it has to be some way of assessing + + + align:start position:0% +but it has to be some way of assessing +how close you are to some sort of goal + + align:start position:0% +how close you are to some sort of goal + + + align:start position:0% +how close you are to some sort of goal +so either there's a short-term goal or + + align:start position:0% +so either there's a short-term goal or + + + align:start position:0% +so either there's a short-term goal or +the overall goal of a game some sort of + + align:start position:0% +the overall goal of a game some sort of + + + align:start position:0% +the overall goal of a game some sort of +scoring function and that goes into some + + align:start position:0% +scoring function and that goes into some + + + align:start position:0% +scoring function and that goes into some +sort of player input + + align:start position:0% + + + + align:start position:0% + +there are some versions of this diagram + + align:start position:0% +there are some versions of this diagram + + + align:start position:0% +there are some versions of this diagram +that separates this into two things + + align:start position:0% +that separates this into two things + + + align:start position:0% +that separates this into two things +that's kind of like the player decides + + align:start position:0% +that's kind of like the player decides + + + align:start position:0% +that's kind of like the player decides +what they're going to do and then + + align:start position:0% +what they're going to do and then + + + align:start position:0% +what they're going to do and then +actually execute the input and that goes + + align:start position:0% +actually execute the input and that goes + + + align:start position:0% +actually execute the input and that goes +back and actually there is one more + + align:start position:0% +back and actually there is one more + + + align:start position:0% +back and actually there is one more +stage sorry there is one more stage and + + align:start position:0% +stage sorry there is one more stage and + + + align:start position:0% +stage sorry there is one more stage and +that's the kind of the mechanical bias + + align:start position:0% + + + + align:start position:0% + +so so the state of the game can be + + align:start position:0% +so so the state of the game can be + + + align:start position:0% +so so the state of the game can be +revealed in some sort of scoring fun + + align:start position:0% +revealed in some sort of scoring fun + + + align:start position:0% +revealed in some sort of scoring fun +part in a player SSS what they want to + + align:start position:0% +part in a player SSS what they want to + + + align:start position:0% +part in a player SSS what they want to +do and then tries to execute it that is + + align:start position:0% +do and then tries to execute it that is + + + align:start position:0% +do and then tries to execute it that is +filtered within the computers or the + + align:start position:0% +filtered within the computers or the + + + align:start position:0% +filtered within the computers or the +board games or the card games + + align:start position:0% +board games or the card games + + + align:start position:0% +board games or the card games +interpretation of what that inputs gonna + + align:start position:0% +interpretation of what that inputs gonna + + + align:start position:0% +interpretation of what that inputs gonna +do and then that feeds back into a game + + align:start position:0% +do and then that feeds back into a game + + + align:start position:0% +do and then that feeds back into a game +state right so for games like Mario Kart + + align:start position:0% +state right so for games like Mario Kart + + + align:start position:0% +state right so for games like Mario Kart +you know you perceive that you are doing + + align:start position:0% +you know you perceive that you are doing + + + align:start position:0% +you know you perceive that you are doing +you perceive you are doing madly because + + align:start position:0% +you perceive you are doing madly because + + + align:start position:0% +you perceive you are doing madly because +you all you know you are the last one at + + align:start position:0% +you all you know you are the last one at + + + align:start position:0% +you all you know you are the last one at +the back of the of the races you drive + + align:start position:0% +the back of the of the races you drive + + + align:start position:0% +the back of the of the races you drive +your your vehicle into one of those + + align:start position:0% +your your vehicle into one of those + + + align:start position:0% +your your vehicle into one of those +rotating boxes because that you're + + align:start position:0% +rotating boxes because that you're + + + align:start position:0% +rotating boxes because that you're +deliberately steering into them because + + align:start position:0% +deliberately steering into them because + + + align:start position:0% +deliberately steering into them because +they're probably your only chance to be + + align:start position:0% +they're probably your only chance to be + + + align:start position:0% +they're probably your only chance to be +able to catch up again you'll get + + align:start position:0% +able to catch up again you'll get + + + align:start position:0% +able to catch up again you'll get +usually something really really sweet + + align:start position:0% +usually something really really sweet + + + align:start position:0% +usually something really really sweet +because you're all the way behind and + + align:start position:0% +because you're all the way behind and + + + align:start position:0% +because you're all the way behind and +the way how the game is designed if + + align:start position:0% +the way how the game is designed if + + + align:start position:0% +the way how the game is designed if +you're all the way behind you get all + + align:start position:0% +you're all the way behind you get all + + + align:start position:0% +you're all the way behind you get all +the best toys you get all the every + + align:start position:0% +the best toys you get all the every + + + align:start position:0% +the best toys you get all the every +single tool that you need to be able to + + align:start position:0% +single tool that you need to be able to + + + align:start position:0% +single tool that you need to be able to +catch up is given to you when you're all + + align:start position:0% +catch up is given to you when you're all + + + align:start position:0% +catch up is given to you when you're all +the way in the back + + align:start position:0% +the way in the back + + + align:start position:0% +the way in the back +that's the mechanic bias all right it + + align:start position:0% +that's the mechanic bias all right it + + + align:start position:0% +that's the mechanic bias all right it +gives you the right tool and that + + align:start position:0% +gives you the right tool and that + + + align:start position:0% +gives you the right tool and that +effects game state because now you have + + align:start position:0% +effects game state because now you have + + + align:start position:0% +effects game state because now you have +this wonderful tool and you use it + + align:start position:0% +this wonderful tool and you use it + + + align:start position:0% +this wonderful tool and you use it +hopefully it works you know and then you + + align:start position:0% +hopefully it works you know and then you + + + align:start position:0% +hopefully it works you know and then you +gain a couple of places up in the race + + align:start position:0% +gain a couple of places up in the race + + + align:start position:0% +gain a couple of places up in the race +so that there are a couple of other + + align:start position:0% +so that there are a couple of other + + + align:start position:0% +so that there are a couple of other +examples that are a little bit you know + + align:start position:0% +examples that are a little bit you know + + + align:start position:0% +examples that are a little bit you know +clearer so say say basketball if you've + + align:start position:0% +clearer so say say basketball if you've + + + align:start position:0% +clearer so say say basketball if you've +got a situation where you've got five + + align:start position:0% +got a situation where you've got five + + + align:start position:0% +got a situation where you've got five +people on your side you could do a game + + align:start position:0% +people on your side you could do a game + + + align:start position:0% +people on your side you could do a game +where if you start to have a lead of + + align:start position:0% +where if you start to have a lead of + + + align:start position:0% +where if you start to have a lead of +five points + + align:start position:0% +five points + + + align:start position:0% +five points +you lose a player you know someone's + + align:start position:0% +you lose a player you know someone's + + + align:start position:0% +you lose a player you know someone's +benched so is that peccadilloes that + + align:start position:0% +benched so is that peccadilloes that + + + align:start position:0% +benched so is that peccadilloes that +positive that's negative right because + + align:start position:0% +positive that's negative right because + + + align:start position:0% +positive that's negative right because +you say all right you were far enough + + align:start position:0% +you say all right you were far enough + + + align:start position:0% +you say all right you were far enough +ahead we're going to take away one of + + align:start position:0% +ahead we're going to take away one of + + + align:start position:0% +ahead we're going to take away one of +the advantages is there another way to + + align:start position:0% +the advantages is there another way to + + + align:start position:0% +the advantages is there another way to +do negative feedback on that example + + align:start position:0% +do negative feedback on that example + + + align:start position:0% +do negative feedback on that example +instead of taking away a player you can + + align:start position:0% +instead of taking away a player you can + + + align:start position:0% +instead of taking away a player you can +add another player to the other side all + + align:start position:0% +add another player to the other side all + + + align:start position:0% +add another player to the other side all +right + + align:start position:0% +right + + + align:start position:0% +right +that's also negative feedback you know + + align:start position:0% +that's also negative feedback you know + + + align:start position:0% +that's also negative feedback you know +that even though you're adding something + + align:start position:0% +that even though you're adding something + + + align:start position:0% +that even though you're adding something +what you're really doing is you're going + + align:start position:0% +what you're really doing is you're going + + + align:start position:0% +what you're really doing is you're going +to give an advantage to someone who is + + align:start position:0% +to give an advantage to someone who is + + + align:start position:0% +to give an advantage to someone who is +not doing so on and does try to bring + + align:start position:0% +not doing so on and does try to bring + + + align:start position:0% +not doing so on and does try to bring +things away forever + + align:start position:0% +things away forever + + + align:start position:0% +things away forever +positive feedback version of this would + + align:start position:0% +positive feedback version of this would + + + align:start position:0% +positive feedback version of this would +be I was thinking something more literal + + align:start position:0% +be I was thinking something more literal + + + align:start position:0% +be I was thinking something more literal +like just giving the person who that the + + align:start position:0% +like just giving the person who that the + + + align:start position:0% +like just giving the person who that the +team that I hit extra players right like + + align:start position:0% +team that I hit extra players right like + + + align:start position:0% +team that I hit extra players right like +you could do it every five points that + + align:start position:0% +you could do it every five points that + + + align:start position:0% +you could do it every five points that +you get one more player and pretty soon + + align:start position:0% +you get one more player and pretty soon + + + align:start position:0% +you get one more player and pretty soon +you've got to buckle yeah and then you + + align:start position:0% +you've got to buckle yeah and then you + + + align:start position:0% +you've got to buckle yeah and then you +just have more more people then anyone + + align:start position:0% +just have more more people then anyone + + + align:start position:0% +just have more more people then anyone +can move on the basketball court and as + + align:start position:0% +can move on the basketball court and as + + + align:start position:0% +can move on the basketball court and as +a result of that you kind of with my + + align:start position:0% +a result of that you kind of with my + + + align:start position:0% +a result of that you kind of with my +default sorry it's like + + align:start position:0% +default sorry it's like + + + align:start position:0% +default sorry it's like +somebody's on fire and make three shots + + align:start position:0% +somebody's on fire and make three shots + + + align:start position:0% +somebody's on fire and make three shots +in a row and a lot of something just + + align:start position:0% +in a row and a lot of something just + + + align:start position:0% +in a row and a lot of something just +like doing it better explain it run + + align:start position:0% +like doing it better explain it run + + + align:start position:0% +like doing it better explain it run +faster they jump a little higher yeah + + align:start position:0% +faster they jump a little higher yeah + + + align:start position:0% +faster they jump a little higher yeah +and the computer game you kissed eclis + + align:start position:0% +and the computer game you kissed eclis + + + align:start position:0% +and the computer game you kissed eclis +if you're if you're throwing a good game + + align:start position:0% +if you're if you're throwing a good game + + + align:start position:0% +if you're if you're throwing a good game +and you're doing better than war a + + align:start position:0% +and you're doing better than war a + + + align:start position:0% +and you're doing better than war a +mortgage is better better pitches more + + align:start position:0% +mortgage is better better pitches more + + + align:start position:0% +mortgage is better better pitches more +playing better but I'm wondering whether + + align:start position:0% +playing better but I'm wondering whether + + + align:start position:0% +playing better but I'm wondering whether +that's correlation of causation + + align:start position:0% +that's correlation of causation + + + align:start position:0% +that's correlation of causation +it's like if the reason why you're doing + + align:start position:0% +it's like if the reason why you're doing + + + align:start position:0% +it's like if the reason why you're doing +better be great effort right now they're + + align:start position:0% +better be great effort right now they're + + + align:start position:0% +better be great effort right now they're +thinking it's causation is causation but + + align:start position:0% +thinking it's causation is causation but + + + align:start position:0% +thinking it's causation is causation but +it definitely comes up in someone + + align:start position:0% +it definitely comes up in someone + + + align:start position:0% +it definitely comes up in someone +psychology right you know is that you + + align:start position:0% +psychology right you know is that you + + + align:start position:0% +psychology right you know is that you +you are sort of building on the mental + + align:start position:0% +you are sort of building on the mental + + + align:start position:0% +you are sort of building on the mental +momentum of doing well and similarly a + + align:start position:0% +momentum of doing well and similarly a + + + align:start position:0% +momentum of doing well and similarly a +team that's not doing well can lose hope + + align:start position:0% +team that's not doing well can lose hope + + + align:start position:0% +team that's not doing well can lose hope +that's that's again that's positive + + align:start position:0% +that's that's again that's positive + + + align:start position:0% +that's that's again that's positive +feedback I just want to be extremely + + align:start position:0% +feedback I just want to be extremely + + + align:start position:0% +feedback I just want to be extremely +clear about that we use the positive is + + align:start position:0% +clear about that we use the positive is + + + align:start position:0% +clear about that we use the positive is +there anything that sort of amplifies + + align:start position:0% +there anything that sort of amplifies + + + align:start position:0% +there anything that sort of amplifies +differences that already exist so now + + align:start position:0% +differences that already exist so now + + + align:start position:0% +differences that already exist so now +let me there are a couple of things to + + align:start position:0% +let me there are a couple of things to + + + align:start position:0% +let me there are a couple of things to +think about when it comes to feedback + + align:start position:0% +think about when it comes to feedback + + + align:start position:0% +think about when it comes to feedback +especially as a problem-solving + + align:start position:0% +especially as a problem-solving + + + align:start position:0% +especially as a problem-solving +technique for design so we've already + + align:start position:0% +technique for design so we've already + + + align:start position:0% +technique for design so we've already +talked about how negative feedback tries + + align:start position:0% +talked about how negative feedback tries + + + align:start position:0% +talked about how negative feedback tries +to bring things down to equilibrium so + + align:start position:0% +to bring things down to equilibrium so + + + align:start position:0% +to bring things down to equilibrium so +it's a stabilizing force if your game is + + align:start position:0% +it's a stabilizing force if your game is + + + align:start position:0% +it's a stabilizing force if your game is +like out of control and unpredictable + + align:start position:0% +like out of control and unpredictable + + + align:start position:0% +like out of control and unpredictable +and chaotic negative feedback and sort + + align:start position:0% +and chaotic negative feedback and sort + + + align:start position:0% +and chaotic negative feedback and sort +of like doing things a little bit I + + align:start position:0% +of like doing things a little bit I + + + align:start position:0% +of like doing things a little bit I +assure me may be unpredictable but it's + + align:start position:0% +assure me may be unpredictable but it's + + + align:start position:0% +assure me may be unpredictable but it's +not going to hurt me so bad or if + + align:start position:0% +not going to hurt me so bad or if + + + align:start position:0% +not going to hurt me so bad or if +somebody gets an advantage it's not + + align:start position:0% +somebody gets an advantage it's not + + + align:start position:0% +somebody gets an advantage it's not +going to be it's not going to be a + + align:start position:0% +going to be it's not going to be a + + + align:start position:0% +going to be it's not going to be a +runaway advantage similar behavior games + + align:start position:0% +runaway advantage similar behavior games + + + align:start position:0% +runaway advantage similar behavior games +just kind of you know actually always + + align:start position:0% +just kind of you know actually always + + + align:start position:0% +just kind of you know actually always +hovering and equilibrium and nobody + + align:start position:0% +hovering and equilibrium and nobody + + + align:start position:0% +hovering and equilibrium and nobody +seems to be getting advantage and + + align:start position:0% +seems to be getting advantage and + + + align:start position:0% +seems to be getting advantage and +positive feedback mechanisms will be + + align:start position:0% +positive feedback mechanisms will be + + + align:start position:0% +positive feedback mechanisms will be +something will destabilize that well it + + align:start position:0% +something will destabilize that well it + + + align:start position:0% +something will destabilize that well it +will make it more likely that somebody + + align:start position:0% +will make it more likely that somebody + + + align:start position:0% +will make it more likely that somebody +who get an advantage will actually get a + + align:start position:0% +who get an advantage will actually get a + + + align:start position:0% +who get an advantage will actually get a +large advantage + + align:start position:0% +large advantage + + + align:start position:0% +large advantage +and that could be a good thing if your + + align:start position:0% +and that could be a good thing if your + + + align:start position:0% +and that could be a good thing if your +games kind of like doll and it's always + + align:start position:0% +games kind of like doll and it's always + + + align:start position:0% +games kind of like doll and it's always +just kind of hovering at the same level + + align:start position:0% +just kind of hovering at the same level + + + align:start position:0% +just kind of hovering at the same level +but that's it but that's a trade-off + + align:start position:0% +but that's it but that's a trade-off + + + align:start position:0% +but that's it but that's a trade-off +with that because any amount of feedback + + align:start position:0% +with that because any amount of feedback + + + align:start position:0% +with that because any amount of feedback +that you're adding into a into your game + + align:start position:0% +that you're adding into a into your game + + + align:start position:0% +that you're adding into a into your game +especially this kind of automated + + align:start position:0% +especially this kind of automated + + + align:start position:0% +especially this kind of automated +feedback this is something that your + + align:start position:0% +feedback this is something that your + + + align:start position:0% +feedback this is something that your +rules are automatically generating can + + align:start position:0% +rules are automatically generating can + + + align:start position:0% +rules are automatically generating can +actually be taking control away from + + align:start position:0% +actually be taking control away from + + + align:start position:0% +actually be taking control away from +players and as a result of that might + + align:start position:0% +players and as a result of that might + + + align:start position:0% +players and as a result of that might +actually make a game less engaging so + + align:start position:0% +actually make a game less engaging so + + + align:start position:0% +actually make a game less engaging so +even a game like with like a party all + + align:start position:0% +even a game like with like a party all + + + align:start position:0% +even a game like with like a party all +right this game is too stable well going + + align:start position:0% +right this game is too stable well going + + + align:start position:0% +right this game is too stable well going +to add some positive feedback mechanisms + + align:start position:0% +to add some positive feedback mechanisms + + + align:start position:0% +to add some positive feedback mechanisms +so that people who have an advantage can + + align:start position:0% +so that people who have an advantage can + + + align:start position:0% +so that people who have an advantage can +sort of capitalize on that advantage but + + align:start position:0% +sort of capitalize on that advantage but + + + align:start position:0% +sort of capitalize on that advantage but +if if that's not done right then you've + + align:start position:0% +if if that's not done right then you've + + + align:start position:0% +if if that's not done right then you've +just got a situation where once once up + + align:start position:0% +just got a situation where once once up + + + align:start position:0% +just got a situation where once once up +someone starts winning everybody else + + align:start position:0% +someone starts winning everybody else + + + align:start position:0% +someone starts winning everybody else +loses interest because there's no way + + align:start position:0% +loses interest because there's no way + + + align:start position:0% +loses interest because there's no way +that they came in sort of catch up so + + align:start position:0% +that they came in sort of catch up so + + + align:start position:0% +that they came in sort of catch up so +these stabilizes it in a point yeah + + align:start position:0% +these stabilizes it in a point yeah + + + align:start position:0% +these stabilizes it in a point yeah +someone's gonna win this game whereas + + align:start position:0% +someone's gonna win this game whereas + + + align:start position:0% +someone's gonna win this game whereas +previously is always stuck in + + align:start position:0% +previously is always stuck in + + + align:start position:0% +previously is always stuck in +equilibrium but it's actually lost it's + + align:start position:0% +equilibrium but it's actually lost it's + + + align:start position:0% +equilibrium but it's actually lost it's +very easy to sort of lose people in a + + align:start position:0% +very easy to sort of lose people in a + + + align:start position:0% +very easy to sort of lose people in a +process because you just create an + + align:start position:0% +process because you just create an + + + align:start position:0% +process because you just create an +automated system to take control away + + align:start position:0% +automated system to take control away + + + align:start position:0% +automated system to take control away +for that so that's one danger of putting + + align:start position:0% +for that so that's one danger of putting + + + align:start position:0% +for that so that's one danger of putting +in a feedback system also we talked + + align:start position:0% +in a feedback system also we talked + + + align:start position:0% +in a feedback system also we talked +about breaking things down so we could + + align:start position:0% +about breaking things down so we could + + + align:start position:0% +about breaking things down so we could +never be able to sort of like make + + align:start position:0% +never be able to sort of like make + + + align:start position:0% +never be able to sort of like make +things a little bit easier for people to + + align:start position:0% +things a little bit easier for people to + + + align:start position:0% +things a little bit easier for people to +catch up on to make advantages a little + + align:start position:0% +catch up on to make advantages a little + + + align:start position:0% +catch up on to make advantages a little +bit less drastic that can also make a + + align:start position:0% +bit less drastic that can also make a + + + align:start position:0% +bit less drastic that can also make a +game much longer right there's nobody + + align:start position:0% +game much longer right there's nobody + + + align:start position:0% +game much longer right there's nobody +get an advantage and depending on your + + align:start position:0% +get an advantage and depending on your + + + align:start position:0% +get an advantage and depending on your +win condition depending on your end of + + align:start position:0% +win condition depending on your end of + + + align:start position:0% +win condition depending on your end of +game conditions could actually just you + + align:start position:0% +game conditions could actually just you + + + align:start position:0% +game conditions could actually just you +know make it interminably long you can + + align:start position:0% +know make it interminably long you can + + + align:start position:0% +know make it interminably long you can +take a half an hour game and make it one + + align:start position:0% +take a half an hour game and make it one + + + align:start position:0% +take a half an hour game and make it one +our game so on the flipside positive + + align:start position:0% +our game so on the flipside positive + + + align:start position:0% +our game so on the flipside positive +feedback game can actually help rein in + + align:start position:0% +feedback game can actually help rein in + + + align:start position:0% +feedback game can actually help rein in +the length of the game so the game is + + align:start position:0% +the length of the game so the game is + + + align:start position:0% +the length of the game so the game is +currently taking you know an hour long + + align:start position:0% +currently taking you know an hour long + + + align:start position:0% +currently taking you know an hour long +with anything like that and and your + + align:start position:0% +with anything like that and and your + + + align:start position:0% +with anything like that and and your +victory conditions happen to be on + + align:start position:0% +victory conditions happen to be on + + + align:start position:0% +victory conditions happen to be on +getting gaining an advantage over your + + align:start position:0% +getting gaining an advantage over your + + + align:start position:0% +getting gaining an advantage over your +the opponents that a positive feedback + + align:start position:0% +the opponents that a positive feedback + + + align:start position:0% +the opponents that a positive feedback +system can help speed that along right + + align:start position:0% +system can help speed that along right + + + align:start position:0% +system can help speed that along right +okay maybe we can cut it down by half by + + align:start position:0% +okay maybe we can cut it down by half by + + + align:start position:0% +okay maybe we can cut it down by half by +just giving some advantages to the + + align:start position:0% +just giving some advantages to the + + + align:start position:0% +just giving some advantages to the +person who's ahead or penalizing the + + align:start position:0% +person who's ahead or penalizing the + + + align:start position:0% +person who's ahead or penalizing the +people who are behind that's a + + align:start position:0% +people who are behind that's a + + + align:start position:0% +people who are behind that's a +interesting little side effect which is + + align:start position:0% +interesting little side effect which is + + + align:start position:0% +interesting little side effect which is +positive because positive feedback + + align:start position:0% +positive because positive feedback + + + align:start position:0% +positive because positive feedback +builds on itself if you have an + + align:start position:0% +builds on itself if you have an + + + align:start position:0% +builds on itself if you have an +advantage early on when you have an + + align:start position:0% +advantage early on when you have an + + + align:start position:0% +advantage early on when you have an +early success then a positive feedback + + align:start position:0% +early success then a positive feedback + + + align:start position:0% +early success then a positive feedback +is going to be the mechanism that's + + align:start position:0% +is going to be the mechanism that's + + + align:start position:0% +is going to be the mechanism that's +going to help you fill in that on the + + align:start position:0% +going to help you fill in that on the + + + align:start position:0% +going to help you fill in that on the +other hand if you have a negative + + align:start position:0% +other hand if you have a negative + + + align:start position:0% +other hand if you have a negative +feedback system in a game which means + + align:start position:0% +feedback system in a game which means + + + align:start position:0% +feedback system in a game which means +everything's kind of being brought down + + align:start position:0% +everything's kind of being brought down + + + align:start position:0% +everything's kind of being brought down +to an equilibrium but everyone's getting + + align:start position:0% +to an equilibrium but everyone's getting + + + align:start position:0% +to an equilibrium but everyone's getting +closer to actually finishing the game + + align:start position:0% +closer to actually finishing the game + + + align:start position:0% +closer to actually finishing the game +but no one really has like a huge lead + + align:start position:0% +but no one really has like a huge lead + + + align:start position:0% +but no one really has like a huge lead +then late successes mean a lot more that + + align:start position:0% +then late successes mean a lot more that + + + align:start position:0% +then late successes mean a lot more that +last boost when you are near the final + + align:start position:0% +last boost when you are near the final + + + align:start position:0% +last boost when you are near the final +the winning line was the finish line the + + align:start position:0% +the winning line was the finish line the + + + align:start position:0% +the winning line was the finish line the +finish line that last boost of the + + align:start position:0% +finish line that last boost of the + + + align:start position:0% +finish line that last boost of the +filler of before you hit the finish line + + align:start position:0% +filler of before you hit the finish line + + + align:start position:0% +filler of before you hit the finish line +and very last Verano mariokart means a + + align:start position:0% +and very last Verano mariokart means a + + + align:start position:0% +and very last Verano mariokart means a +lot because the whole game is designed + + align:start position:0% +lot because the whole game is designed + + + align:start position:0% +lot because the whole game is designed +with and and could make all the + + align:start position:0% +with and and could make all the + + + align:start position:0% +with and and could make all the +difference + + align:start position:0% +difference + + + align:start position:0% +difference +that was pretty much it for not fighting + + align:start position:0% +that was pretty much it for not fighting + + + align:start position:0% +that was pretty much it for not fighting +over it so I'm just saying you know so + + align:start position:0% +over it so I'm just saying you know so + + + align:start position:0% +over it so I'm just saying you know so +negative feedback prioritizes what + + align:start position:0% +negative feedback prioritizes what + + + align:start position:0% +negative feedback prioritizes what +happens they make games but it's + + align:start position:0% +happens they make games but it's + + + align:start position:0% +happens they make games but it's +positive feedback prioritizes what + + align:start position:0% +positive feedback prioritizes what + + + align:start position:0% +positive feedback prioritizes what +happens earlier on strategies that you + + align:start position:0% +happens earlier on strategies that you + + + align:start position:0% +happens earlier on strategies that you +pick the cards that you haven't before + + align:start position:0% +pick the cards that you haven't before + + + align:start position:0% +pick the cards that you haven't before +all employee right in the beginning on + + align:start position:0% +all employee right in the beginning on + + + align:start position:0% +all employee right in the beginning on +the minute something of the people + + align:start position:0% +the minute something of the people + + + align:start position:0% +the minute something of the people +positive feedback stress exactly + + align:start position:0% + + + + align:start position:0% + +and finally always keep in mind that any + + align:start position:0% +and finally always keep in mind that any + + + align:start position:0% +and finally always keep in mind that any +interaction of game systems probably + + align:start position:0% +interaction of game systems probably + + + align:start position:0% +interaction of game systems probably +creates version feedback loops even if + + align:start position:0% +creates version feedback loops even if + + + align:start position:0% +creates version feedback loops even if +you have a design of it so what we want + + align:start position:0% +you have a design of it so what we want + + + align:start position:0% +you have a design of it so what we want +to do is you want to try to find that + + align:start position:0% +to do is you want to try to find that + + + align:start position:0% +to do is you want to try to find that +there the tool out there that I've seen + + align:start position:0% +there the tool out there that I've seen + + + align:start position:0% +there the tool out there that I've seen +some student teams use and I don't know + + align:start position:0% +some student teams use and I don't know + + + align:start position:0% +some student teams use and I don't know +whether it be useful for you're just + + align:start position:0% +whether it be useful for you're just + + + align:start position:0% +whether it be useful for you're just +going to do good has anyone heard of + + align:start position:0% +going to do good has anyone heard of + + + align:start position:0% +going to do good has anyone heard of +causal loop diagrams + + align:start position:0% +causal loop diagrams + + + align:start position:0% +causal loop diagrams +that's from economics you + + align:start position:0% + + + + align:start position:0% + +it's a very simple concept you just + + align:start position:0% +it's a very simple concept you just + + + align:start position:0% +it's a very simple concept you just +basically write it your variables in + + align:start position:0% +basically write it your variables in + + + align:start position:0% +basically write it your variables in +your game and you can add in a few looks + + align:start position:0% +your game and you can add in a few looks + + + align:start position:0% +your game and you can add in a few looks +sort of in between variables if you know + + align:start position:0% +sort of in between variables if you know + + + align:start position:0% +sort of in between variables if you know +how players are thinking about your game + + align:start position:0% +how players are thinking about your game + + + align:start position:0% +how players are thinking about your game +so I could be using Mario Kart too much + + align:start position:0% +so I could be using Mario Kart too much + + + align:start position:0% +so I could be using Mario Kart too much +for example let's pick another game with + + align:start position:0% +for example let's pick another game with + + + align:start position:0% +for example let's pick another game with +obviously just okay so so our pieces in + + align:start position:0% +obviously just okay so so our pieces in + + + align:start position:0% +obviously just okay so so our pieces in +chess sort of influences the number of + + align:start position:0% +chess sort of influences the number of + + + align:start position:0% +chess sort of influences the number of +attack past all right so which means + + align:start position:0% +attack past all right so which means + + + align:start position:0% +attack past all right so which means +number of pieces + + align:start position:0% +number of pieces + + + align:start position:0% +number of pieces +well influence a number of pieces being + + align:start position:0% +well influence a number of pieces being + + + align:start position:0% +well influence a number of pieces being +threatened off of your opponent's pieces + + align:start position:0% +threatened off of your opponent's pieces + + + align:start position:0% +threatened off of your opponent's pieces +right + + align:start position:0% + + + + align:start position:0% + +Christian until it's just number one end + + align:start position:0% + + + + align:start position:0% + +this taken now if I flick this around a + + align:start position:0% +this taken now if I flick this around a + + + align:start position:0% +this taken now if I flick this around a +little bit I think I could make an + + align:start position:0% +little bit I think I could make an + + + align:start position:0% +little bit I think I could make an +argument that if I switch this to number + + align:start position:0% +argument that if I switch this to number + + + align:start position:0% +argument that if I switch this to number +of my own pieces rather than my opponent + + align:start position:0% +of my own pieces rather than my opponent + + + align:start position:0% +of my own pieces rather than my opponent +pieces then it connects but not + + align:start position:0% +pieces then it connects but not + + + align:start position:0% +pieces then it connects but not +everything is a positive connection + + align:start position:0% +everything is a positive connection + + + align:start position:0% +everything is a positive connection +number of pieces that I have means I if + + align:start position:0% +number of pieces that I have means I if + + + align:start position:0% +number of pieces that I have means I if +I have more pieces I have more attack us + + align:start position:0% +I have more pieces I have more attack us + + + align:start position:0% +I have more pieces I have more attack us +Sarnoff is not exactly linear but it's + + align:start position:0% +Sarnoff is not exactly linear but it's + + + align:start position:0% +Sarnoff is not exactly linear but it's +not ever landed on Chester right I have + + align:start position:0% +not ever landed on Chester right I have + + + align:start position:0% +not ever landed on Chester right I have +more pieces then thank you I am always + + align:start position:0% +more pieces then thank you I am always + + + align:start position:0% +more pieces then thank you I am always +to attack if I have always to attack + + align:start position:0% +to attack if I have always to attack + + + align:start position:0% +to attack if I have always to attack +than you then actually I have few Jesus + + align:start position:0% +than you then actually I have few Jesus + + + align:start position:0% +than you then actually I have few Jesus +read it because I get it's also more + + align:start position:0% +read it because I get it's also more + + + align:start position:0% +read it because I get it's also more +ways to defend so I can say anything + + align:start position:0% +ways to defend so I can say anything + + + align:start position:0% +ways to defend so I can say anything +that I can attack I can prevent from I + + align:start position:0% +that I can attack I can prevent from I + + + align:start position:0% +that I can attack I can prevent from I +say well if you take this piece then I + + align:start position:0% +say well if you take this piece then I + + + align:start position:0% +say well if you take this piece then I +just want to take the piece that we just + + align:start position:0% +just want to take the piece that we just + + + align:start position:0% +just want to take the piece that we just +used and there's good a one-for-one + + align:start position:0% +used and there's good a one-for-one + + + align:start position:0% +used and there's good a one-for-one +trade postal that offices and you and so + + align:start position:0% +trade postal that offices and you and so + + + align:start position:0% +trade postal that offices and you and so +if I can if fewer of my pieces are + + align:start position:0% +if I can if fewer of my pieces are + + + align:start position:0% +if I can if fewer of my pieces are +threatened that means I can see number + + align:start position:0% +threatened that means I can see number + + + align:start position:0% +threatened that means I can see number +of pieces of threatened goes down then a + + align:start position:0% +of pieces of threatened goes down then a + + + align:start position:0% +of pieces of threatened goes down then a +number of pieces that I can kick goes up + + align:start position:0% +number of pieces that I can kick goes up + + + align:start position:0% +number of pieces that I can kick goes up +I think I think I know + + align:start position:0% + + + + align:start position:0% + +and the number of Europe then you come + + align:start position:0% +and the number of Europe then you come + + + align:start position:0% +and the number of Europe then you come +you're taking this down as well yeah + + align:start position:0% +you're taking this down as well yeah + + + align:start position:0% +you're taking this down as well yeah +those two are yes yes all right so and + + align:start position:0% +those two are yes yes all right so and + + + align:start position:0% +those two are yes yes all right so and +that should be a series and and and if + + align:start position:0% +that should be a series and and and if + + + align:start position:0% +that should be a series and and and if +the number of pieces taken goes down if + + align:start position:0% +the number of pieces taken goes down if + + + align:start position:0% +the number of pieces taken goes down if +there are pieces of piece of stick and + + align:start position:0% +there are pieces of piece of stick and + + + align:start position:0% +there are pieces of piece of stick and +goes up then I have two pieces if I have + + align:start position:0% +goes up then I have two pieces if I have + + + align:start position:0% +goes up then I have two pieces if I have +fewer pieces taken then I am one four + + align:start position:0% +fewer pieces taken then I am one four + + + align:start position:0% +fewer pieces taken then I am one four +pieces so we have two pluses that we + + align:start position:0% +pieces so we have two pluses that we + + + align:start position:0% +pieces so we have two pluses that we +have to - as relations overall this + + align:start position:0% +have to - as relations overall this + + + align:start position:0% +have to - as relations overall this +entire loop is fully reinforced English + + align:start position:0% +entire loop is fully reinforced English + + + align:start position:0% +entire loop is fully reinforced English +right this is positive feedback you can + + align:start position:0% +right this is positive feedback you can + + + align:start position:0% +right this is positive feedback you can +connect this to other things maybe in + + align:start position:0% +connect this to other things maybe in + + + align:start position:0% +connect this to other things maybe in +chess and I I'm not terribly good at + + align:start position:0% +chess and I I'm not terribly good at + + + align:start position:0% +chess and I I'm not terribly good at +causal loop diagrams to begin with but + + align:start position:0% +causal loop diagrams to begin with but + + + align:start position:0% +causal loop diagrams to begin with but +in chess again you might be able to + + align:start position:0% +in chess again you might be able to + + + align:start position:0% +in chess again you might be able to +connect it to other things like a + + align:start position:0% +connect it to other things like a + + + align:start position:0% +connect it to other things like a +positioning sensor or the valuable + + align:start position:0% +positioning sensor or the valuable + + + align:start position:0% +positioning sensor or the valuable +pieces and so what those might be + + align:start position:0% +pieces and so what those might be + + + align:start position:0% +pieces and so what those might be +reinforcing and reinforcing is basically + + align:start position:0% +reinforcing and reinforcing is basically + + + align:start position:0% +reinforcing and reinforcing is basically +another one I was saying in the positive + + align:start position:0% +another one I was saying in the positive + + + align:start position:0% +another one I was saying in the positive +feedback you another way that you can + + align:start position:0% +feedback you another way that you can + + + align:start position:0% +feedback you another way that you can +say is that the balancing loop which + + align:start position:0% +say is that the balancing loop which + + + align:start position:0% +say is that the balancing loop which +means not a negative image and that's + + align:start position:0% +means not a negative image and that's + + + align:start position:0% +means not a negative image and that's +usually depicted with + + align:start position:0% + + + + align:start position:0% + +the students that I've seen uses for all + + align:start position:0% +the students that I've seen uses for all + + + align:start position:0% +the students that I've seen uses for all +the students from my economics and + + align:start position:0% +the students from my economics and + + + align:start position:0% +the students from my economics and +management who actually learned that + + align:start position:0% +management who actually learned that + + + align:start position:0% +management who actually learned that +because they're trying to study things + + align:start position:0% +because they're trying to study things + + + align:start position:0% +because they're trying to study things +like supply chain power system that's + + align:start position:0% +like supply chain power system that's + + + align:start position:0% +like supply chain power system that's +why before you use this tool and then + + align:start position:0% +why before you use this tool and then + + + align:start position:0% +why before you use this tool and then +decaffeinated and but you know so it + + align:start position:0% +decaffeinated and but you know so it + + + align:start position:0% +decaffeinated and but you know so it +might be was looking up there might be a + + align:start position:0% +might be was looking up there might be a + + + align:start position:0% +might be was looking up there might be a +useful diagnostic tool for your game if + + align:start position:0% +useful diagnostic tool for your game if + + + align:start position:0% +useful diagnostic tool for your game if +you're just trying to figure out what + + align:start position:0% +you're just trying to figure out what + + + align:start position:0% +you're just trying to figure out what +are all the different loops just like + + align:start position:0% +are all the different loops just like + + + align:start position:0% +are all the different loops just like +right just write out all of your + + align:start position:0% +right just write out all of your + + + align:start position:0% +right just write out all of your +variables and figure out whether things + + align:start position:0% +variables and figure out whether things + + + align:start position:0% +variables and figure out whether things +even up to negatives and to positives + + align:start position:0% +even up to negatives and to positives + + + align:start position:0% +even up to negatives and to positives +gives you reinforce in the loop + + align:start position:0% +gives you reinforce in the loop + + + align:start position:0% +gives you reinforce in the loop +positive positive positive positive + + align:start position:0% +positive positive positive positive + + + align:start position:0% +positive positive positive positive +gives you a reinforcing do positive + + align:start position:0% +gives you a reinforcing do positive + + + align:start position:0% +gives you a reinforcing do positive +positive negative and that's a fancy + + align:start position:0% +positive negative and that's a fancy + + + align:start position:0% +positive negative and that's a fancy +blue so the one thing to keep in mind is + + align:start position:0% +blue so the one thing to keep in mind is + + + align:start position:0% +blue so the one thing to keep in mind is +that occasionally what happens is that + + align:start position:0% +that occasionally what happens is that + + + align:start position:0% +that occasionally what happens is that +you have something like you get a + + align:start position:0% +you have something like you get a + + + align:start position:0% +you have something like you get a +benefit in something for instance why we + + align:start position:0% +benefit in something for instance why we + + + align:start position:0% +benefit in something for instance why we +was a box fiber change and you can you + + align:start position:0% +was a box fiber change and you can you + + + align:start position:0% +was a box fiber change and you can you +can put money you can invest money into + + align:start position:0% +can put money you can invest money into + + + align:start position:0% +can put money you can invest money into +research yeah at some point of time in a + + align:start position:0% +research yeah at some point of time in a + + + align:start position:0% +research yeah at some point of time in a +far far future that is off right but + + align:start position:0% +far far future that is off right but + + + align:start position:0% +far far future that is off right but +that doesn't necessarily mean that it's + + align:start position:0% +that doesn't necessarily mean that it's + + + align:start position:0% +that doesn't necessarily mean that it's +going to pay off right away + + align:start position:0% +going to pay off right away + + + align:start position:0% +going to pay off right away +so so it so that may end up in + + align:start position:0% +so so it so that may end up in + + + align:start position:0% +so so it so that may end up in +situations where you start getting + + align:start position:0% +situations where you start getting + + + align:start position:0% +situations where you start getting +things like big fluctuations around is + + align:start position:0% +things like big fluctuations around is + + + align:start position:0% +things like big fluctuations around is +still it's all balancing in terms of + + align:start position:0% +still it's all balancing in terms of + + + align:start position:0% +still it's all balancing in terms of +equilibrium by this but just like a + + align:start position:0% +equilibrium by this but just like a + + + align:start position:0% +equilibrium by this but just like a +thermostat that's you know very slow to + + align:start position:0% +thermostat that's you know very slow to + + + align:start position:0% +thermostat that's you know very slow to +respond you might have something like a + + align:start position:0% +respond you might have something like a + + + align:start position:0% +respond you might have something like a +heater that warms up a room and it makes + + align:start position:0% +heater that warms up a room and it makes + + + align:start position:0% +heater that warms up a room and it makes +a room to warm before the sensor + + align:start position:0% +a room to warm before the sensor + + + align:start position:0% +a room to warm before the sensor +actually realizes that it's warm enough + + align:start position:0% +actually realizes that it's warm enough + + + align:start position:0% +actually realizes that it's warm enough +and then shuts it off and then the room + + align:start position:0% +and then shuts it off and then the room + + + align:start position:0% +and then shuts it off and then the room +becomes really really cold before the + + align:start position:0% +becomes really really cold before the + + + align:start position:0% +becomes really really cold before the +sensor realizes that is too cold and + + align:start position:0% +sensor realizes that is too cold and + + + align:start position:0% +sensor realizes that is too cold and +then turns it back on again + + align:start position:0% +then turns it back on again + + + align:start position:0% +then turns it back on again +and that's again this these oscillations + + align:start position:0% +and that's again this these oscillations + + + align:start position:0% +and that's again this these oscillations +so keep in mind also things like time + + align:start position:0% +so keep in mind also things like time + + + align:start position:0% +so keep in mind also things like time +light when you're drawing out is that + + align:start position:0% +light when you're drawing out is that + + + align:start position:0% +light when you're drawing out is that +right now how long does it take this + + align:start position:0% +right now how long does it take this + + + align:start position:0% +right now how long does it take this +advantage to coming to that advantage of + + align:start position:0% +advantage to coming to that advantage of + + + align:start position:0% +advantage to coming to that advantage of +this increase to 30 to that decrease um + + align:start position:0% +this increase to 30 to that decrease um + + + align:start position:0% +this increase to 30 to that decrease um +and yeah any questions like how much + + align:start position:0% +and yeah any questions like how much + + + align:start position:0% +and yeah any questions like how much +does your point being really near like + + align:start position:0% +does your point being really near like + + + align:start position:0% +does your point being really near like +how much about a one-point lead right + + align:start position:0% +how much about a one-point lead right + + + align:start position:0% +how much about a one-point lead right +now + + align:start position:0% +now + + + align:start position:0% +now +positive P that means this is really + + align:start position:0% +positive P that means this is really + + + align:start position:0% +positive P that means this is really +like a cheaper way to provide more for + + align:start position:0% +like a cheaper way to provide more for + + + align:start position:0% +like a cheaper way to provide more for +me later and even though the user system + + align:start position:0% +me later and even though the user system + + + align:start position:0% +me later and even though the user system +o- it's actually more like a half point + + align:start position:0% +o- it's actually more like a half point + + + align:start position:0% +o- it's actually more like a half point +we just was like yeah I that means like + + align:start position:0% +we just was like yeah I that means like + + + align:start position:0% +we just was like yeah I that means like +power grid for instance and I definitely + + align:start position:0% +power grid for instance and I definitely + + + align:start position:0% +power grid for instance and I definitely +have a case where sometimes negative in + + align:start position:0% +have a case where sometimes negative in + + + align:start position:0% +have a case where sometimes negative in +fact to literally be negative in the + + align:start position:0% +fact to literally be negative in the + + + align:start position:0% +fact to literally be negative in the +sense that like taking this leader it + + align:start position:0% +sense that like taking this leader it + + + align:start position:0% +sense that like taking this leader it +now could actually hurt me because the + + align:start position:0% +now could actually hurt me because the + + + align:start position:0% +now could actually hurt me because the +thinking could actually like for me long + + align:start position:0% +thinking could actually like for me long + + + align:start position:0% +thinking could actually like for me long +yeah I didn't positive and negative + + align:start position:0% +yeah I didn't positive and negative + + + align:start position:0% +yeah I didn't positive and negative +since I was originally inherited from + + align:start position:0% +since I was originally inherited from + + + align:start position:0% +since I was originally inherited from +Matt's cybernetics it's actually + + align:start position:0% +Matt's cybernetics it's actually + + + align:start position:0% +Matt's cybernetics it's actually +referring to like a differential yeah + + align:start position:0% +referring to like a differential yeah + + + align:start position:0% +referring to like a differential yeah +rather than B that is it's referring to + + align:start position:0% +rather than B that is it's referring to + + + align:start position:0% +rather than B that is it's referring to +a rate of change right so rather than + + align:start position:0% +a rate of change right so rather than + + + align:start position:0% +a rate of change right so rather than +the actual moment yeah so so that's + + align:start position:0% +the actual moment yeah so so that's + + + align:start position:0% +the actual moment yeah so so that's +that's that's something that we that we + + align:start position:0% +that's that's something that we that we + + + align:start position:0% +that's that's something that we that we +that doesn't package everything up but + + align:start position:0% +that doesn't package everything up but + + + align:start position:0% +that doesn't package everything up but +it's sort of thus it's not because some + + align:start position:0% +it's sort of thus it's not because some + + + align:start position:0% +it's sort of thus it's not because some +people think negative feedback means bad + + align:start position:0% +people think negative feedback means bad + + + align:start position:0% +people think negative feedback means bad +right that's like no we're not gonna sit + + align:start position:0% +right that's like no we're not gonna sit + + + align:start position:0% +right that's like no we're not gonna sit +back put me good and could mean that and + + align:start position:0% +back put me good and could mean that and + + + align:start position:0% +back put me good and could mean that and +negative feedback for someone who's + + align:start position:0% +negative feedback for someone who's + + + align:start position:0% +negative feedback for someone who's +behind could be an advantage so the + + align:start position:0% +behind could be an advantage so the + + + align:start position:0% +behind could be an advantage so the +terminology doesn't quite make it easy + + align:start position:0% +terminology doesn't quite make it easy + + + align:start position:0% +terminology doesn't quite make it easy +for it for everyone to use but it's + + align:start position:0% +for it for everyone to use but it's + + + align:start position:0% +for it for everyone to use but it's +something that is currently in use plus + + align:start position:0% +something that is currently in use plus + + + align:start position:0% +something that is currently in use plus +good to know that game designers between + + align:start position:0% +good to know that game designers between + + + align:start position:0% +good to know that game designers between +using terms the control system where + + align:start position:0% +using terms the control system where + + + align:start position:0% +using terms the control system where +positive feedback would be bad yeah I + + align:start position:0% +positive feedback would be bad yeah I + + + align:start position:0% +positive feedback would be bad yeah I +think that's kind of the opposite of the + + align:start position:0% +think that's kind of the opposite of the + + + align:start position:0% +think that's kind of the opposite of the +word control shake chain reaction might + + align:start position:0% +word control shake chain reaction might + + + align:start position:0% +word control shake chain reaction might +be a great way to describe for you any + + align:start position:0% +be a great way to describe for you any + + + align:start position:0% +be a great way to describe for you any +other questions about these ideas + + align:start position:0% +other questions about these ideas + + + align:start position:0% +other questions about these ideas +a lot of these stuff that I've been + + align:start position:0% +a lot of these stuff that I've been + + + align:start position:0% +a lot of these stuff that I've been +talking about is known as first order + + align:start position:0% +talking about is known as first order + + + align:start position:0% +talking about is known as first order +cybernetics which is basically the + + align:start position:0% +cybernetics which is basically the + + + align:start position:0% +cybernetics which is basically the +system it's doing its own thing happily + + align:start position:0% +system it's doing its own thing happily + + + align:start position:0% +system it's doing its own thing happily +and if I'm taking a look at the system + + align:start position:0% +and if I'm taking a look at the system + + + align:start position:0% +and if I'm taking a look at the system +from the outside you know I don't really + + align:start position:0% +from the outside you know I don't really + + + align:start position:0% +from the outside you know I don't really +have any influence how it's going to + + align:start position:0% +have any influence how it's going to + + + align:start position:0% +have any influence how it's going to +perform but there is a second order + + align:start position:0% +perform but there is a second order + + + align:start position:0% +perform but there is a second order +that's cool whole school of second order + + align:start position:0% +that's cool whole school of second order + + + align:start position:0% +that's cool whole school of second order +cybernetics and I'm totally unfamiliar + + align:start position:0% +cybernetics and I'm totally unfamiliar + + + align:start position:0% +cybernetics and I'm totally unfamiliar +with which actually takes into account + + align:start position:0% +with which actually takes into account + + + align:start position:0% +with which actually takes into account +having a person which you would think + + align:start position:0% +having a person which you would think + + + align:start position:0% +having a person which you would think +would be a lot more of the comfortable + + align:start position:0% +would be a lot more of the comfortable + + + align:start position:0% +would be a lot more of the comfortable +games especially game being played by + + align:start position:0% +games especially game being played by + + + align:start position:0% +games especially game being played by +cable but I think I don't know + + align:start position:0% +cable but I think I don't know + + + align:start position:0% +cable but I think I don't know +southern accent interested in a research + + align:start position:0% +southern accent interested in a research + + + align:start position:0% +southern accent interested in a research +project something like that you know + + align:start position:0% +project something like that you know + + + align:start position:0% +project something like that you know +this is something I never thought I + + align:start position:0% +this is something I never thought I + + + align:start position:0% +this is something I never thought I +would have to be able to find out about + + align:start position:0% +would have to be able to find out about + + + align:start position:0% +would have to be able to find out about +all right + + align:start position:0% + + + + align:start position:0% + +one final word this is a very formal way + + align:start position:0% +one final word this is a very formal way + + + align:start position:0% +one final word this is a very formal way +of looking at game systems just as I + + align:start position:0% +of looking at game systems just as I + + + align:start position:0% +of looking at game systems just as I +have already I just admitted that it + + align:start position:0% +have already I just admitted that it + + + align:start position:0% +have already I just admitted that it +doesn't take people's involvement in the + + align:start position:0% +doesn't take people's involvement in the + + + align:start position:0% +doesn't take people's involvement in the +process very well it is not necessarily + + align:start position:0% +process very well it is not necessarily + + + align:start position:0% +process very well it is not necessarily +the case that the form of ways of + + align:start position:0% +the case that the form of ways of + + + align:start position:0% +the case that the form of ways of +looking at a system just looking at how + + align:start position:0% +looking at a system just looking at how + + + align:start position:0% +looking at a system just looking at how +the rules interact it's necessarily + + align:start position:0% +the rules interact it's necessarily + + + align:start position:0% +the rules interact it's necessarily +always the best way to look at at games + + align:start position:0% +always the best way to look at at games + + + align:start position:0% +always the best way to look at at games +in many ways in many occasions that it's + + align:start position:0% +in many ways in many occasions that it's + + + align:start position:0% +in many ways in many occasions that it's +actually not a useful technique you know + + align:start position:0% +actually not a useful technique you know + + + align:start position:0% +actually not a useful technique you know +I can have all these systems in my rules + + align:start position:0% +I can have all these systems in my rules + + + align:start position:0% +I can have all these systems in my rules +but if you know if people are going to + + align:start position:0% +but if you know if people are going to + + + align:start position:0% +but if you know if people are going to +read my rules and interpret my rules + + align:start position:0% +read my rules and interpret my rules + + + align:start position:0% +read my rules and interpret my rules +that's you've already seen happen in + + align:start position:0% +that's you've already seen happen in + + + align:start position:0% +that's you've already seen happen in +this class differently than dia you know + + align:start position:0% +this class differently than dia you know + + + align:start position:0% +this class differently than dia you know +they may be motivated to do things that + + align:start position:0% +they may be motivated to do things that + + + align:start position:0% +they may be motivated to do things that +operate against my assumptions because + + align:start position:0% +operate against my assumptions because + + + align:start position:0% +operate against my assumptions because +there's something else in my Meredith my + + align:start position:0% +there's something else in my Meredith my + + + align:start position:0% +there's something else in my Meredith my +aesthetic in their own individual + + align:start position:0% +aesthetic in their own individual + + + align:start position:0% +aesthetic in their own individual +motivations like if somebody wants to + + align:start position:0% +motivations like if somebody wants to + + + align:start position:0% +motivations like if somebody wants to +take down somebody else in the game just + + align:start position:0% +take down somebody else in the game just + + + align:start position:0% +take down somebody else in the game just +because they happened to keep that + + align:start position:0% +because they happened to keep that + + + align:start position:0% +because they happened to keep that +person you know and it's outside of the + + align:start position:0% +person you know and it's outside of the + + + align:start position:0% +person you know and it's outside of the +gating rules you know then nothing in + + align:start position:0% +gating rules you know then nothing in + + + align:start position:0% +gating rules you know then nothing in +the rules going to tell me that but it's + + align:start position:0% +the rules going to tell me that but it's + + + align:start position:0% +the rules going to tell me that but it's +still going to affect how that game gets + + align:start position:0% +still going to affect how that game gets + + + align:start position:0% +still going to affect how that game gets +played and I wondered and I wanted to + + align:start position:0% +played and I wondered and I wanted to + + + align:start position:0% +played and I wondered and I wanted to +thank you account the game of the policy + + align:start position:0% +thank you account the game of the policy + + + align:start position:0% +thank you account the game of the policy +for instance you know it has to take + + align:start position:0% +for instance you know it has to take + + + align:start position:0% +for instance you know it has to take +into account the fact that people that + + align:start position:0% +into account the fact that people that + + + align:start position:0% +into account the fact that people that +you're probably playing in with people + + align:start position:0% +you're probably playing in with people + + + align:start position:0% +you're probably playing in with people +that you know and you have some sort of + + align:start position:0% +that you know and you have some sort of + + + align:start position:0% +that you know and you have some sort of +existing relationship I don't think it + + align:start position:0% +existing relationship I don't think it + + + align:start position:0% +existing relationship I don't think it +does a very very good job of insulating + + align:start position:0% +does a very very good job of insulating + + + align:start position:0% +does a very very good job of insulating +you from the fallout of the game + + align:start position:0% + + + + align:start position:0% + +everyone knows nothing about right okay + + align:start position:0% +everyone knows nothing about right okay + + + align:start position:0% +everyone knows nothing about right okay +just aren't friends and people that you + + align:start position:0% +just aren't friends and people that you + + + align:start position:0% +just aren't friends and people that you +play diplomacy with anymore that's why I + + align:start position:0% +play diplomacy with anymore that's why I + + + align:start position:0% +play diplomacy with anymore that's why I +like talking about it so you know that + + align:start position:0% +like talking about it so you know that + + + align:start position:0% +like talking about it so you know that +that will be going into things like + + align:start position:0% +that will be going into things like + + + align:start position:0% +that will be going into things like +games games for social play in the + + align:start position:0% +games games for social play in the + + + align:start position:0% +games games for social play in the +social function + + align:start position:0% +social function + + + align:start position:0% +social function +you interact with with people some other + + align:start position:0% +you interact with with people some other + + + align:start position:0% +you interact with with people some other +topics are going to be things like games + + align:start position:0% +topics are going to be things like games + + + align:start position:0% +topics are going to be things like games +of simulation games as a and as its + + align:start position:0% +of simulation games as a and as its + + + align:start position:0% +of simulation games as a and as its +might be flow on the road to the real + + align:start position:0% +might be flow on the road to the real + + + align:start position:0% +might be flow on the road to the real +world but an interesting way you know + + align:start position:0% +world but an interesting way you know + + + align:start position:0% +world but an interesting way you know +but it could be a fun house terribly so + + align:start position:0% +but it could be a fun house terribly so + + + align:start position:0% +but it could be a fun house terribly so +so we'll be looking at that in weeks + + align:start position:0% +so we'll be looking at that in weeks + + + align:start position:0% +so we'll be looking at that in weeks +this is probably about exploring this + + align:start position:0% +this is probably about exploring this + + + align:start position:0% +this is probably about exploring this +weekend maybe talking about things like + + align:start position:0% +weekend maybe talking about things like + + + align:start position:0% +weekend maybe talking about things like +information system there's also very + + align:start position:0% +information system there's also very + + + align:start position:0% +information system there's also very +formal just keep in mind that's just + + align:start position:0% +formal just keep in mind that's just + + + align:start position:0% +formal just keep in mind that's just +like one school of paper and writing so + + align:start position:0% +like one school of paper and writing so + + + align:start position:0% +like one school of paper and writing so +weird things that all have an + + align:start position:0% +weird things that all have an + + + align:start position:0% +weird things that all have an +interesting way of dealing with this + + align:start position:0% +interesting way of dealing with this + + + align:start position:0% +interesting way of dealing with this +some of them you are going to see these + + align:start position:0% +some of them you are going to see these + + + align:start position:0% +some of them you are going to see these +problems come up like especially in + + align:start position:0% +problems come up like especially in + + + align:start position:0% +problems come up like especially in +through the game Tommy people we have in + + align:start position:0% +through the game Tommy people we have in + + + align:start position:0% +through the game Tommy people we have in +class today one two three four five six + + align:start position:0% +class today one two three four five six + + + align:start position:0% +class today one two three four five six +seven so 11 that's like + + align:start position:0% + + + + align:start position:0% + +okay so we got a hot to be employed on + + align:start position:0% +okay so we got a hot to be employed on + + + align:start position:0% +okay so we got a hot to be employed on +internet ones are some games like king + + align:start position:0% +internet ones are some games like king + + + align:start position:0% +internet ones are some games like king +of Tokyo is very much a king of the hill + + align:start position:0% +of Tokyo is very much a king of the hill + + + align:start position:0% +of Tokyo is very much a king of the hill +need so it's deliberately trying to ask + + align:start position:0% +need so it's deliberately trying to ask + + + align:start position:0% +need so it's deliberately trying to ask +you to take down the person who's led + + align:start position:0% +you to take down the person who's led + + + align:start position:0% +you to take down the person who's led +and they gave mechanics make you wonder + + align:start position:0% +and they gave mechanics make you wonder + + + align:start position:0% +and they gave mechanics make you wonder +whether being in the lead is really all + + align:start position:0% +whether being in the lead is really all + + + align:start position:0% +whether being in the lead is really all +that great so this playing around is + + align:start position:0% +that great so this playing around is + + + align:start position:0% +that great so this playing around is +like a small world is occupying + + align:start position:0% +like a small world is occupying + + + align:start position:0% +like a small world is occupying +territory with your audience + + align:start position:0% +territory with your audience + + + align:start position:0% +territory with your audience +yeah yeah anybody talk about Vinci small + + align:start position:0% +yeah yeah anybody talk about Vinci small + + + align:start position:0% +yeah yeah anybody talk about Vinci small +roles a updated Vinci yeah no faster to + + align:start position:0% +roles a updated Vinci yeah no faster to + + + align:start position:0% +roles a updated Vinci yeah no faster to +play fix that arrives that we are + + align:start position:0% +play fix that arrives that we are + + + align:start position:0% +play fix that arrives that we are +to if anybody wants to take a look at + + align:start position:0% +to if anybody wants to take a look at + + + align:start position:0% +to if anybody wants to take a look at +that we don't because they think that + + align:start position:0% +that we don't because they think that + + + align:start position:0% +that we don't because they think that +two hours under surface area you know it + + align:start position:0% +two hours under surface area you know it + + + align:start position:0% +two hours under surface area you know it +is lifeboats it's about bunch of sailors + + align:start position:0% +is lifeboats it's about bunch of sailors + + + align:start position:0% +is lifeboats it's about bunch of sailors +trying to get to the trying to get to + + align:start position:0% +trying to get to the trying to get to + + + align:start position:0% +trying to get to the trying to get to +safety + + align:start position:0% +safety + + + align:start position:0% +safety +basically the boat is same boats are + + align:start position:0% +basically the boat is same boats are + + + align:start position:0% +basically the boat is same boats are +sinking and they're all trying to get + + align:start position:0% +sinking and they're all trying to get + + + align:start position:0% +sinking and they're all trying to get +the safety and everyone's jumping on and + + align:start position:0% +the safety and everyone's jumping on and + + + align:start position:0% +the safety and everyone's jumping on and +pushing people out of lifeboats and + + align:start position:0% +pushing people out of lifeboats and + + + align:start position:0% +pushing people out of lifeboats and +slipping to lifeboats and that so so + + align:start position:0% +slipping to lifeboats and that so so + + + align:start position:0% +slipping to lifeboats and that so so +it's all about 2020 yeah I know + + align:start position:0% +it's all about 2020 yeah I know + + + align:start position:0% +it's all about 2020 yeah I know +relatively little about these ones I + + align:start position:0% +relatively little about these ones I + + + align:start position:0% +relatively little about these ones I +forget + + align:start position:0% +forget + + + align:start position:0% +forget +yeah these were recommended by some + + align:start position:0% +yeah these were recommended by some + + + align:start position:0% +yeah these were recommended by some +money scholars when I + + align:start position:0% + + + + align:start position:0% + +el Grande Spanish shame about the yes + + align:start position:0% +el Grande Spanish shame about the yes + + + align:start position:0% +el Grande Spanish shame about the yes +yeah that's the pocket or anybody but + + align:start position:0% +yeah that's the pocket or anybody but + + + align:start position:0% +yeah that's the pocket or anybody but +I'm pretty sure I look in there against + + align:start position:0% +I'm pretty sure I look in there against + + + align:start position:0% +I'm pretty sure I look in there against +operative prediction of future intrigue + + align:start position:0% +operative prediction of future intrigue + + + align:start position:0% +operative prediction of future intrigue +is again that I like the theme the books + + align:start position:0% +is again that I like the theme the books + + + align:start position:0% +is again that I like the theme the books +it's basically you run a university and + + align:start position:0% +it's basically you run a university and + + + align:start position:0% +it's basically you run a university and +you're trying to put your clothes off in + + align:start position:0% +you're trying to put your clothes off in + + + align:start position:0% +you're trying to put your clothes off in +other universities that's not what the + + align:start position:0% +other universities that's not what the + + + align:start position:0% +other universities that's not what the +game says in the box but I would like + + align:start position:0% +game says in the box but I would like + + + align:start position:0% +game says in the box but I would like +you to try playing the game with that so + + align:start position:0% +you to try playing the game with that so + + + align:start position:0% +you to try playing the game with that so +so yeah you know it's an interesting + + align:start position:0% +so yeah you know it's an interesting + + + align:start position:0% +so yeah you know it's an interesting +game because you are trying you are + + align:start position:0% +game because you are trying you are + + + align:start position:0% +game because you are trying you are +doing exactly the same thing that + + align:start position:0% +doing exactly the same thing that + + + align:start position:0% +doing exactly the same thing that +everybody else is trying to do but in + + align:start position:0% +everybody else is trying to do but in + + + align:start position:0% +everybody else is trying to do but in +order to succeed in the game you have to + + align:start position:0% +order to succeed in the game you have to + + + align:start position:0% +order to succeed in the game you have to +put your troops your your your scholars + + align:start position:0% +put your troops your your your scholars + + + align:start position:0% +put your troops your your your scholars +into other people's territory if you are + + align:start position:0% +into other people's territory if you are + + + align:start position:0% +into other people's territory if you are +trying to put into yours and there's a + + align:start position:0% +trying to put into yours and there's a + + + align:start position:0% +trying to put into yours and there's a +mutual benefit and a whole lot of + + align:start position:0% +mutual benefit and a whole lot of + + + align:start position:0% +mutual benefit and a whole lot of +politicking so a lot of opportunities + + align:start position:0% +politicking so a lot of opportunities + + + align:start position:0% +politicking so a lot of opportunities +for you to sort of it's a pretty good + + align:start position:0% +for you to sort of it's a pretty good + + + align:start position:0% +for you to sort of it's a pretty good +feedback game because it gives you a + + align:start position:0% +feedback game because it gives you a + + + align:start position:0% +feedback game because it gives you a +whole bunch of tools to basically take a + + align:start position:0% +whole bunch of tools to basically take a + + + align:start position:0% +whole bunch of tools to basically take a +look at with which games hi the Wayne + + align:start position:0% +look at with which games hi the Wayne + + + align:start position:0% +look at with which games hi the Wayne +foundation hide the progress or players + + align:start position:0% +foundation hide the progress or players + + + align:start position:0% +foundation hide the progress or players +from you you know something + + align:start position:0% +from you you know something + + + align:start position:0% +from you you know something +some of these games you can easily see + + align:start position:0% +some of these games you can easily see + + + align:start position:0% +some of these games you can easily see +this ahead is up on this game is really + + align:start position:0% +this ahead is up on this game is really + + + align:start position:0% +this ahead is up on this game is really +hard to tell it has a debris so that it + + align:start position:0% +hard to tell it has a debris so that it + + + align:start position:0% +hard to tell it has a debris so that it +was have these situations where someone + + align:start position:0% +was have these situations where someone + + + align:start position:0% +was have these situations where someone +organza on people who + + align:start position:0% +organza on people who + + + align:start position:0% +organza on people who +look at me how they avoid things like + + align:start position:0% +look at me how they avoid things like + + + align:start position:0% +look at me how they avoid things like +totally how they discouraged in place + + align:start position:0% +totally how they discouraged in place + + + align:start position:0% +totally how they discouraged in place +I'm 90 or maybe something to encourage + + align:start position:0% +I'm 90 or maybe something to encourage + + + align:start position:0% +I'm 90 or maybe something to encourage +them and use them to the compound to in + + align:start position:0% +them and use them to the compound to in + + + align:start position:0% +them and use them to the compound to in +favor of them I think we've definitely + + align:start position:0% +favor of them I think we've definitely + + + align:start position:0% +favor of them I think we've definitely +decided all right and then what are + + align:start position:0% +decided all right and then what are + + + align:start position:0% +decided all right and then what are +these boxes up at three o'clock working + + align:start position:0% +these boxes up at three o'clock working + + + align:start position:0% +these boxes up at three o'clock working +our team's it's going to be a lot of + + align:start position:0% +our team's it's going to be a lot of + + + align:start position:0% +our team's it's going to be a lot of +time you're gonna see your team's before + + align:start position:0% +time you're gonna see your team's before + + + align:start position:0% +time you're gonna see your team's before +spring break + + align:start position:0% +spring break + + + align:start position:0% +spring break +so you might want to give each other + + align:start position:0% +so you might want to give each other + + + align:start position:0% +so you might want to give each other +tasks to work on during spring break if + + align:start position:0% +tasks to work on during spring break if + + + align:start position:0% +tasks to work on during spring break if +you can't think of anything test over + + align:start position:0% +you can't think of anything test over + + + align:start position:0% +you can't think of anything test over +spring break Prague a good number of you + + align:start position:0% +spring break Prague a good number of you + + + align:start position:0% +spring break Prague a good number of you +I'm going to see people who who haven't + + align:start position:0% +I'm going to see people who who haven't + + + align:start position:0% +I'm going to see people who who haven't +seen your game yeah and written rules + + align:start position:0% +seen your game yeah and written rules + + + align:start position:0% +seen your game yeah and written rules +the first round here it's great + + align:start position:0% +the first round here it's great + + + align:start position:0% +the first round here it's great +and if you don't have a first chocolate + + align:start position:0% +and if you don't have a first chocolate + + + align:start position:0% +and if you don't have a first chocolate +written rules then this last hour of + + align:start position:0% +written rules then this last hour of + + + align:start position:0% +written rules then this last hour of +class is probably a good time to bring + + align:start position:0% +class is probably a good time to bring + + + align:start position:0% +class is probably a good time to bring +up the laptop and just might start + + align:start position:0% +up the laptop and just might start + + + align:start position:0% +up the laptop and just might start +editing that tanks so that yes you can + + align:start position:0% +editing that tanks so that yes you can + + + align:start position:0% +editing that tanks so that yes you can +go into spring break with something that + + align:start position:0% +go into spring break with something that + + + align:start position:0% +go into spring break with something that +you can test with all right for the game + + align:start position:0% +you can test with all right for the game + + + align:start position:0% +you can test with all right for the game +is probably people to play twice maybe + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +yeah but Brandis probably thank him for + + align:start position:0% +yeah but Brandis probably thank him for + + + align:start position:0% +yeah but Brandis probably thank him for +all the sporty + + align:start position:0% +all the sporty + + + align:start position:0% +all the sporty +[Music] \ No newline at end of file diff --git a/wnOOQnW5Un4.txt b/wnOOQnW5Un4.txt new file mode 100644 index 0000000000000000000000000000000000000000..3f2539ef5fe4e96fe86c4cc04b53a4c2c2638741 --- /dev/null +++ b/wnOOQnW5Un4.txt @@ -0,0 +1,1870 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high quality educational +resources for free. + +To make a donation or view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +PROFESSOR: Please note that this +is a clicker competition, + +perhaps the last of the year, +before you put in your vote + +for this particular +clicker question. + +And the defending champs are +recitation three, and I + +believe that no recitation +has won more than once. + +Is that true? + +Is there a recitation that +has two victories? + +So, this might be your last +chance if your recitation has + +not won, or if you want to be +decisive victors in the + +clicker competition to have a +repeat victory, this is your + +chance -- no pressure. + +But go ahead and put in +your clicker response. + +OK, let's just take 10 more +seconds to click in. + +OK, the answer here is b, and +the trick was to recognize + +which is the equation for first +order half life, and + +which is the equation for +second order half life. + +Most people got this right. + +And we picked this clicker +question to demonstrate a + +point that will, for the final +exam, which is that you will + +have an equation sheet +of all the equations. + +There'll be a few you have to +memorize, we'll let you know + +what they are, but that's +a lot of equations. + +So, so far on each hour exam, +you've had an equation sheet + +that's been related to that +particular material. + +On the final, you of an equation +sheet that has the + +equations from exam 1, exam 2, +exam 3, and also the fourth + +exam material. + +And so, it doesn't say on them, +oh, first order half + +life equation, colon, and then +the equation, it just has all + +of the equations. + +So one thing that you have to do +is recognize which equation + +can be applied where. + +And this is something that +people, occasionally that's + +part of knowing the +material is to + +know/recognize the equations. + +You don't have to memorize them, +but you do have to be + +able to recognize them and +know when to apply them. + +So that's something you should +be thinking about as you're + +reviewing the material +for the exam. + +And we're just going to at jump +right in and talk about + +reaction mechanisms. So this is +the last type of question + +that's on problem-set 10. + +So, when you're investigating +reaction mechanisms, you often + +will have an experimentally +determined rate law, and then + +you want to try to come up +with a mechanism that's + +consistent with that rate law. + +So, for this particular +reaction, we have 2 n o plus o + +2 going to 2 n o 2 gas. + +And experimental rate laws +determined there was a rate + +constant called k obs, for k +observed, the observed rate + +constant that was calculated. + +And we know that it's the order +of the reactions here. + +Overall, what is the overall +order at this + +particular rate law? + +Three. + +So we have second order in n +o and first order in o 2. + +So if it's overall order of +three, is it likely to occur + +in one step? + +No. + +What would it be called if it +did occur in one step -- if + +three things came together +at the same + +time to form a product? + +Yeah, thermonuclear. + +And we learned last time +that thermonuclear + +reactions are rare. + +So it's unlikely that those +three things, the two n o's + +and the one o 2 are going to +come together at the same time + +to form product, so +it probably has + +more than one step. + +So, on the board here and on +your notes, we have a two-step + +proposed mechanism, and let's +talk about these two steps and + +come up with a rate law that's +consistent with this + +mechanism, and then see if +that agrees with the + +experimental rate law +that was determined. + +So, in the first step of this +reaction, we have 2 n o's + +coming together. + +There's a little rate constant, +k 1, above the first + +arrow, and for the reverse +direction, we have k minus 1, + +so this is written as a +reversible reaction, and it's + +forming an intermediate +n 2 o 2. + +In the second step, we have the +o 2 coming in, reacting + +with that intermediate with a +rate constant, k 2, and it's + +forming two molecules +of n o 2. + +So now we can write the +rates for each of + +these individual steps. + +We can write the rate for the +foward reaction here, and so + +that's going to be +equal to k 1. + +And we have n o, two n +o's, so n o squared. + +And again, this is a step or an +elementary reaction so we + +can write the reaction +exactly as it occurs. + +We can write a rate law for +that step using the + +stiochiometry of the reaction. + +For an overall reaction, you +can't do that, it has to be + +experimentally determined. + +But for an elementary reaction +or a step in a mechanism, you + +can do that. + +So we write it exactly +as it occurs. + +So, what would be the order of +this particular reaction as + +written here? + +Two. + +And what about molecularity? + +It would be bimolecular. + +So we're just getting you used +to some of these terms. + +All right, so then for the +reverse direction, the rate of + +the reverse direction would be +equal to what rate constant? + +k minus 1. + +Times what? + +Yeah, n 2 o 2. + +So what's the order here? + +One. + +And what's this called? + +Yeah, so that's called +unimolecular. + +All right, what about step 2? + +What would be the rate +here, and that + +is a clicker question. + +OK, just 10 more seconds. + +Yup, so we write it exactly as +written, so we have a k 2 + +times the concentration +of o 2 times the + +concentration of n 2 o 2. + +All right, so what is the +overall order here? + +Two. + +And again, that would +be the bimolecular. + +All right, so we have our two +steps, and we've written rates + +for all of those particular +steps. + +Now we're interested in writing +the rate of the + +overall reaction that +forms n o 2. + +So, let's think about what the +rate of n o 2 formation is. + +So, in the last step, we're +forming n o 2, and we can just + +use that last step to +write this out. + +We're forming two molecules +of n o 2. + +So we're going to put a 2 in +there, because the rate at + +which the concentration of this +will increase twice as + +much as will decrease +this amount. + +And the book is somewhat +inconsistent in its use of 2's + +in these equations. + +If you're forming two molecules +in your last step, + +there should be a 2, but 2 is +not always in the answer key. + +So what I've done in the past +is if you put a 2 and there + +should be a 2, great, but if you +don't put it, that's OK, + +too, so I have not taken off for +this because the book is + +not been completely consistent +in its use of that. + +But, if you see a two, and 2 +things are being formed, you + +know where that comes from. + +So, 2 times k 2, that's the +rate constant of that last + +step, and that we're talking +about the concentration of o 2 + +and the concentration +of n 2 o 2. + +So we're writing out just that +last out there with the 2, + +because two molecules of +n o 2 are being formed. + +But we're not done with this, we +can't use this, because it + +has an intermediate +term in there. + +And if we're going to write the +rate of a reaction, the + +rate of product formation, we +can't have any intermediates + +in our equation. + +We need to solve it in terms +of products and reactants. + +So, we need to solve +for n 2 o 2. + +So we need to solve for the +concentration of n 2 o 2, and + +substitute that into +our equation. + +So we need to solve +for it in terms of + +products and reactants. + +So, we need to think about how +this intermediate is formed, + +and we need to think about +how the intermediate is + +decomposed, and we need to +think about how this + +intermediate is consumed. + +So, the net formation of n 2 o +2 is going to be equal to the + +rate at which it's formed. + +So the rate at which +it's formed. + +What step is it formed in, the +intermediate formed in? + +It's in step one in the forward +direction, so the rate + +at which its formed is k +1 times n o squared. + +So that's the forward rate +of the first step. + +Then we need to think about +the rate at which its + +decomposed. + +What step does the intermediate +decompose in? + +Right, the reverse of +the first step. + +So we're going to put a minus +sign here, and k minus 1 times + +the concentration of +the intermediate. + +And then we also want to +think about the rate + +at which it's consumed. + +And it's consumed in the second +step, so that's k 2 + +times the concentration of the +intermediate times the + +concentration of o 2. + +So that's the net formation. + +And now we can use something +called the steady state + +approximation, and the steady +state approximation is used in + +all sorts of kinetics, including +enzyme kinetics, and + +it can be phrased two different +ways, which are + +equivalent. + +You can say that the steady +state approximation is that + +the net formation of the +intermediate equals zero -- + +i.e. this is the net formation +of the intermediate, so this + +entire equation equals zero. + +Another way to say it is that +the rate of formation of the + +intermediate equals +the rate of decay. + +So that's saying the same thing, +that this term is going + +to be equal to those +two terms. That's + +saying the same thing. + +So, if we can set this whole +equation equal to zero, then + +we can solve for the +concentrations of the + +intermediates in terms of the +rate constants and the + +concentrations of the reactants +and the products, + +which is what we need to do. + +So, let's do that. + +So we can rearrange this +expression now that we have + +set equal to zero, and so we can +bring n 2 o 2 over to one + +side, so we have our +intermediate on one side. + +And then we are going to have k +minus 1, and our little k 2 + +times the concentration +of o 2. + +And so, that is the rate in +which the intermediate is + +decomposed and consumed, and +that's going to be equal to + +the rate at which it's formed, +which is another way of + +expressing the steady +state approximation. + +So we've just moved the +decomposed and consumed to one + +side, and we have the rate at +which it's formed on the other + +side, and now we can easily +solve for the concentration of + +the n 2 o 2, so we're going +to do that over here. + +So that's now going to be equal +to our k 1 times n o + +squared over k minus 1 +plus k 2 times the + +concentration of o 2. + +So now we've just solved for n +2 o 2, our intermediate, in + +terms of our rate constants and +in terms of our reactants. + +So that's good. + +Now we need to take this and +substitute it back into here. + +And if we substitute it back +into here, let's do that over + +here, so now we'll have +k, 2 times k 2, we'll + +also have a k 1 term. + +We're going to have, we +have n o squared. + +We also have an o 2 term from +over here, and this is all + +going to be over k minus +1 plus k 2 times our + +concentration of o 2. + +So we've just substituted that +term in here, and now we have + +a new expression for the rate of +our product formation, and + +that's lovely. + +Except that it doesn't agree +with the experiment. + +So we have a problem. + +In the experiment, there's n o +squared and o 2, but there is + +no o 2 in the bottom, so +something is going on. + +So that means that our reaction +as written, which + +didn't have any fast steps or +any slow steps is inconsistent + +if you write a mechanism for +this, if you write a rate law + +for this, it's inconsistent +with the experiment. + +So we need to do more to +our proposed mechanism. + +We need to add fast steps and +slow steps until we can write + +a mechanism that agrees +with the experiment. + +And so, if we want to do this, +we're going to assume, now we + +can try that the first +step is fast and the + +second step is slow. + +So let's talk about this slow +step and what happens if you + +have a slow step. + +So I'm going to introduce this +term of rate determining step. + +So the slowest step in an +elementary reaction is going + +to determine the overall rate. + +If it's slow compared +to the other steps. + +And so, the overall rate, it +can't be any faster than that + +slow step, and that slow step +is going to govern how fast + +the overall reaction is. + +All right, so let me give +you an example of this. + +I know they're you're all +very anxious to complete + +problem-set 10, the last +problem-set that will be + +graded in this course. + +And you know, because I told you +at the beginning of class, + +that after today's lecture, you +will know all the material + +that will allow you to complete +that problem-set. + +So some of you are going to get +really antsy at the end of + +class thinking OK, I can go +and do that problem-set. + +So, you're going to be ready, +you may have already started + +packing up your backpack as the +class is winding down, you + +see we're getting close to the +end of the handouts saying, + +all right, I've got to get out +of here, I've got to get to + +the library and finish the +rest of problem-set 10. + +All right, so let's say it takes +you five seconds to pack + +up and be out the door. + +Or maybe there's some people +coming in, OK, maybe ten + +seconds to get out the door. + +Then you're running down toward +the library and you're + +moving pretty fast, you're +jumping over people that are + +stopping and talking to their +friends, you're moving very + +quickly, you might slide down +the banisters to get to the + +first floor, and you get +to the library, but + +you were too slow. + +Even though you did it really +fast, all the tables are busy, + +everyone else is completing +problem-set 10. + +So you go up and down, you're +looking for a table, there's + +no tables, they're all busy, +everyone has their chemistry + +textbooks out and +they're going. + +All right. + +So, then you have to leave the +library, you go to building 2, + +that's close by, they're +classrooms, they're not in + +use, the first couple +you check there's + +recitations going on. + +Finally you find the +one that's empty. + +When you find it that's empty, +your backpack is off, your + +books are out, your +calculator's + +out and you're going. + +Right, maybe another +ten seconds. + +But it took you about +20 minutes to + +find that free table. + +So, maybe ten seconds to get +out of this classroom, ten + +seconds to get your books out of +your backpack, but then 20 + +minutes overall to find +that free table. + +So that's the rate determining +step, that 20 minutes to find + +that table is going +to control the + +overall rate of the reaction. + +And so, many of you have +probably experienced rate + +determining steps in your life, +some of you may have + +friends that are always your +rate determining step, and so + +you know about this. + +You know about this. + +And so rate determining steps +allow us to come up with + +different kinds of mechanisms +and simplify different + +expressions. + +All right, so let's look at what +this does for us here. + +If we make assumptions now about +a step being fast and a + +step being slow. + +All right, so we're going to be +able to -- this expression + +here, we're going to be +able to simplify. + +All right, so we're going to ask +the question then, here, + +we're assuming that we're going +to say, all right, let's + +just say the first step +is fast and the + +second step is slow. + +We're going to see whether that +gives us an answer that's + +consistent with the +experimentally + +determined rate law. + +So here, if we say this is +fast and this is slow, + +basically we're asking the +question, is the decomposition + +of the intermediate or it's +consumption faster? + +So as we wrote this, then, we're +saying decomposition is + +fast. The first step is fast +and reversible, so the + +decomposition is fast. The +second step is slow, the + +consumption of that intermediate +is slow. + +So that allows us to +change our rate. + +So, what we're then saying in +terms of the here's the words, + +here's sort of the equations, +we're saying that this term + +here, this k minus 1 times the +intermediate term, is a lot + +bigger, because this is +faster than this. + +This is slow, the rate of +consumption is slow. + +So k minus 1 is going to +be a bigger number + +than k 2 times o 2. + +So, if we say that, if we say +this is fast, that's a big + +number, this is a fast step, +k 2 is a small number, it's + +slow, if this is a lot smaller +than k minus 1, and these are + +both appearing in the bottom +of the equation here, that + +allows you to get rid +of this term. + +So if you have something really +big and something + +pretty small, on the bottom of +this equation, the really + +small thing is kind +of insignificant. + +And so we can get rid +of that here. + +So we can get rid +of this term. + +So that allows us to simplify +this expression. + +Now we have k 1 times n o +squared over k minus 1. + +We can also rearrange that and +bring our concentration terms + +on one side, so we have our +intermediate over our n o + +squared and have that now is +going to be equal to k 1 + +over k minus 1. + +What is little rate constant +k 1 over rate + +constant k minus 1? + +Big k, right. + +So that's another way of +saying the equilibrium + +expression. + +So it's the equilibrium constant +for the first step is + +equal to k 1 over k minus 1. + +So basically what we're saying +then, if we have the first + +step being fast and reversible, +and the second + +step being slow, we're saying +that the first step is really + +an equilibrium. + +So what allows us to say that? + +Well, if you have a fast +reversible step followed by a + +slow step, that means that not +much of your intermediate is + +being siphoned off by the second +step, allowing you to + +reach equilibrium. + +So you can think about that in +terms of this plot here. + +If you have reactants going to +intermediate, and this is fast + +and reversible, so they're going +back and forth, fast, + +reversible, and very little of +that intermediate is getting + +siphoned off, this +is very slow. + +So very, very little +of this is being + +siphoned off to products. + +So that allows that first step +to really reach equilibrium + +conditions, because this doesn't +really factor in, and + +so you reach an equilibrium +here. + +And that allows you to simplify +your expressions. + +So now, we can go back with our +simplified expression, and + +we can express it as rate +constant k 1 over rate + +constant k minus 1 times n o +squared, or we can write it as + +the equilibrium constant 1 times +n o squared, and we can + +plug that in solving for +our intermediate. + +And so, if we put that now back +into this expression, we + +have the 2 k 1, k 2, we have our +oxygen concentration and + +our n o squared over k minus 1, +or we can have equilibrium + +constant 1 with our +k 2 in our 2. + +And now, we're consistent. + +If we realize that the k +observed that was given in the + +experimental rate law is a +combination of all of our k + +terms. So it's a combination, +you can't, at least in this + +experiment, you weren't able to +come up with the individual + +rate constants, they just came +up with overall observed rate, + +and so that's all of +our terms in there. + +And so if we put that in here, +we realize that this is + +consistent with the +experiment. + +And in doing these problems, +it's OK to leave your little + +rate constants, it's OK to use +equilibrium constants in + +there, you should show all of +your work, so that if you have + +a k obs in your final answer, we +can look back and see what + +that was equal to. + +So it's hard not to show all +your work as you're writing + +through all of these on a test, +but you can end your + +answer, it would be correct +end your answer + +here or here or here. + +So I don't care which k is +in your final answer, but + +definitely show all your work. + +So that agrees with +the experiment. + +All right, so let's look +at another example now. + +And now we have, again, a 2-step +reaction, and the first + +step is fast and reversible, and +the second step is slow. + +So, with those predictions of +the mechanism, let's just go + +right through and try to solve +for the rate here without + +going through all of the steps +we did the first time and see + +if we can do this more +efficiently. + +And again, this is a reaction +with ozone, and depletion of + +ozone is a major problem that +will be facing us, that has + +faced us, and will continue +to face us in the future. + +All right. + +So lets first think about the +rates of the individual steps. + +So the rate of the forward +reaction here + +is going to be what? + +Just yell it out. + +Yup, k 1 times the concentration +of o 3. + +What about for the +reverse step? + +Yup, it's like clear and then +it gets mumbly. k minus 1 + +times the concentration of o 2 +times this concentration of o, + +which is an intermediate. + +All right, so let's look at +the second step here. + +So the rate here is going to be +k 2 times this intermediate + +-- concentration of this +intermediate, o times the + +concentration of o 3. + +All right, so now we know that +this second step is going to + +be controlling the rate, it's +a slow step, at least that's + +our prediction that we're +going to write a rate + +expression based on. + +And so, that's going to be +our slow step, our rate + +determining step. + +And again, we're forming two +molecules of o 2 in this step. + +So we can have a two in there. + +And that the rate of formation +of o 2 in this last step, 2 + +times k 2 times our intermediate +o times o 3. + +Are we done? + +Was it that easy? + +Are we done? + +No. + +Why isn't this finished? + +There's an intermediate. + +Intermediates will not be your +friend in doing these + +problems. + +Yes, we have an intermediate +so we're not complete. + +We need to solve for o in terms +of products, reactants, + +and rate constants. + +So we're not done. + +So we need to get rid +of the intermediate. + +But now, we can do that more +simply because we've set this + +up that we have a fast +reversible step + +followed by a slow step. + +So we can solve for the +concentration of that + +intermediate in terms of +equilibrium expressions. + +So, if you haven't learned how +to write an equilibrium + +expression yet, remember you +need it for the unit on + +chemical equilibrium, the unit +of acid base, the unit of + +oxidation reduction, and here +you need it again in kinetics, + +so definitely want to be able to +write those for the final. + +So we can go ahead +and write those. + +So, for the first step, again, +it's products over reactants. + +You can also express that in +terms of rate constant k 1 + +over rate constant k minus 1, +and that's all equal to our + +big k, our equilibrium +constant, k 1. + +And so now we can solve in terms +of o, our intermediate, + +and so here, we pull that out, +here we've solved for it in + +terms of k 1 times o 3 over k +minus 1 times o 2, so we just + +brought those to +the other side. + +You could have also used the +equilibrium constant here + +instead of the rate constants, +either one is OK. + +So, now we've solved for it +here, and we can put it down + +into this expression here. + +So we are going back +to our overall + +expression that we wrote. + +So the expression that we wrote +based on this was 2, k 2 + +times the concentration of our +intermediate, times the + +concentration of o 3. + +Now we substitute in for the +intermediate, so we have 2 + +times k 2, k 1, we have o 3 and +an o 3, so that squared, + +over k minus 1 times o 2. + +And this can also be expressed +in terms of k observed, + +putting those terms together, +o 3 squared over o 2. + +And that would be the answer to +what the rate is for that + +particular proposed mechanism. + +So, let's think about if that's +true, what we should + +expect if we do some +experiments, what we should + +expect about the order of the +reactions, and what would + +happen if you double +concentrations of things and + +look for the effect. + +So if you're going to +test this proposal, + +what would we get? + +So, what is the overall order +of this rate law here. + +Oh, sorry, the order first +let's do of o 3. + +2. + +So if we double the +concentration of o 3, what + +would you expect to see +in terms of the rate? + +It will what? + +Yup, quadruple. + +What is the overall order of o +2, or order of o 2, and that + +is a clicker question, +actually. + +So you know what some +people think. + +And not only tell me the order, +but tell me the effect + +of doubling. + +OK, let's just take +10 more seconds. + +Very good. + +All right, so the overall minus +1, that's what it means + +if it's on the bottom of +that equation there. + +And so if we double it +then it should half. + +So overall then, what is the +order of the reaction? + +It's 1. + +And so, remember you can sum up +the order of the individual + +ones to get the overall order, +so the overall order is 1. + +And what about if you double +both things, what's going to + +happen to the rate? + +OK, let's just take +10 more seconds. + +OK, people are doing +quite well on this. + +All right, so you double +both and you double. + +So, everyone's in very good +shape on these types of + +problems, which is excellent +because this is worth + +a lot on the final. + +All right, so let's do a final +example, and in this case + +we're given an experimental rate +law, which is up here, k + +observed times the concentration +of n o and the + +concentration of b r 2, and we +want to figure out from this, + +we'll look at if we have one +step is being fast and the + +other step is being fast, and +see which would be consistent + +with this experimentally +determined rate law. + +So these are some of the types +of problems you have, your + +given experimental rate law and +say tell me which step has + +to be fast and which has to be +slow to have a rate that's + +consistent with the +observed rate. + +So, in this reaction we +have 2 n o plus b r 2 + +going 2 n o b r. + +So if we write this in the first +step, we have n o plus b + +r 2 going to an intermediate, +n o b r 2 with forward rate + +constant, k 1, and reverse +rate constant, k minus 1. + +And in the second step we have +the intermediate interacting + +with another molecule of n o +forming two molecules of n o b + +r, our product. + +So let's consider what the rate +of the forward reaction + +is here, and so that would be +-- you can yell it out. k 1 + +times -- yes, excellent. + +And for the reverse reaction +then we're going to have our k + +minus 1 times our intermediate +concentration. + +Now we can look at step 2 where +our intermediate is + +being consumed, and the rate +would equal then k 2 times the + +concentration of the +intermediate, n o b r 2 times + +the concentration of n o. + +All right, so we know nothing +now about fast or slow steps, + +so we can write the formation +of our product just in terms + +of this second step. + +And again, there are two +molecules being formed, so we + +have a 2, and 2 times this rate +for this second step, k 2 + +times intermediate times n o. + +So again, now we have an +intermediate that we have to + +get rid of. + +We can't have an intermediate +in our final expression. + +But we can't use the equilibrium +constant right now + +because we don't know anything +about what are the fast or the + +slow steps. + +So we're going to write it the +long way with no assumption + +about fast or slow steps. + +So to do this, so we have our +intermediate, and so we're + +going to solve for it in terms +of products and reactants. + +So we're going to write about +the change in the + +concentration of that +intermediate. + +So, the intermediate's being +formed in the first step. + +So we first write the rate at +which it's being formed. + +So it's being formed here, so +that's k 1 times n o times the + +concentration of b r 2, so this +is how it's being formed. + +And then we're going to consider +how it's being + +decomposed, and you told me +before it gets decomposed in + +the reverse of the first step. + +So we have a minus sign, because +this is a negative + +change in concentration, it's +being decomposed, and it's + +being decomposed with a rate +constant of k minus 1 times + +the concentration of +that intermediate. + +And the intermediate's also +being consumed, so that's + +decreasing the concentration of +the intermediate, and it's + +being consumed in this +second step. + +So it's being consumed here with +the rate constant of k 2 + +times the intermediate +times n o. + +So that second step. + +So this is how we write it if +we don't know anything about + +the rate at which -- what's slow +and what's fast. So this + +will always, always work to +write things this way. + +So that's the overall change +in the concentration of the + +intermediate, how it's +being formed, + +decomposed, and consumed. + +Now we can use the steady state +approximation, and you + +can always use the steady state +approximation in these + +problems, and that says that +this net change is going to be + +equal to zero. + +So the steady state +approximation, then, let's you + +set this entire term +equal to zero. + +And sometimes, a question you +might get is to say what the + +steady state approximation is. + +So you should be able to +articulate that in words as + +well as use it on a problem. + +So now we can set this all +equal to zero, and we can + +solve for our concentration +of our intermediate. + +So, rearranging this then, +bringing our intermediate + +terms on one side of the +expression, and again, here's + +the rate at which it's +decomposed and consumed being + +equal to the rate at which +it's being formed. + +And we can pull out our +intermediate, so then that's + +times k minus 1, k 2 times n +o, and that's equal to the + +rate at which it's +being formed. + +And so now we can take that, +divide by that term, and we + +get an expression for the +concentration of the + +intermediate in terms +of our reactants + +and our rate constants. + +So now we need to plug that +back in to the original + +equation that we had. + +So this is what we solved for, +and now we can put it into + +here, and if you rearrange that, +we have the 2, we have + +the k 1, we have the k 2, we +have an n o here, we have an n + +o there, so it's squared, b r 2 +here, and then on the bottom + +we have k minus 1 plus +k 2 times n o. + +OK, so that's great, but that's +not consistent with the + +experimentally determined rate +law, so something has to be + +fast and something +has to be slow. + +So let's first consider if the +first step is slow and the + +second step is fast, which would +mean that the second + +step is bigger, it's faster, +that's k 2 times n o would be + +bigger than k minus 1. + +So the second step then is +fast, faster than this. + +So now why don't you go ahead +and tell me how this + +simplifies if that is true. + +All right, let's just take +10 more seconds. + +Yup. + +All right, let's look at why. + +All right, so that's the answer +and let's consider why. + +So that means if this is much +bigger than this term, that + +cancels out. + +If that cancels out, what else +cancels? k 2 also cancels, and + +what else cancels? one n o +cancels giving you this + +expression. + +And that is consistent with +the answer up there. + +So you could also see that +as the k observed. + +So that's consistent. + +And let's just quick +-- oh, first tell + +me the overall order. + +2. + +And now let's just look at what +would have been true if + +we had done it the +other way around. + +So if we did it the other way +around, we'd say that the + +first step is fast so that's +a lot bigger than this. + +If this is a lot bigger than +that, we'd cancel out this + +second term here. + +Can anything else cancel? + +No. + +So, we're left with this +expression, and that is not + +consistent with this up +here, because we have + +this squared term. + +So even if you write it as +k observed, that's not + +consistent. + +And so, the overall order for +this would have been 3, which + +is not consistent with +the experiment. + +All right, so now you know +everything you need to know to + +finish problem-set 10. + +Don't let anything be your +rate determining step. \ No newline at end of file diff --git a/x-ijexq_D2U.txt b/x-ijexq_D2U.txt new file mode 100644 index 0000000000000000000000000000000000000000..9fba17833a15808eba4cde7f437c90b3a036b5c4 --- /dev/null +++ b/x-ijexq_D2U.txt @@ -0,0 +1,22515 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a creative commons license your support + + align:start position:0% +a creative commons license your support + + + align:start position:0% +a creative commons license your support +will help mit opencourseware continue to + + align:start position:0% +will help mit opencourseware continue to + + + align:start position:0% +will help mit opencourseware continue to +offer high quality educational resources + + align:start position:0% +offer high quality educational resources + + + align:start position:0% +offer high quality educational resources +for free + + align:start position:0% +for free + + + align:start position:0% +for free +to make a donation or to view additional + + align:start position:0% +to make a donation or to view additional + + + align:start position:0% +to make a donation or to view additional +materials from hundreds of mit courses + + align:start position:0% +materials from hundreds of mit courses + + + align:start position:0% +materials from hundreds of mit courses +visit mit opencourseware at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +so yeah today's talk is on computational + + align:start position:0% +so yeah today's talk is on computational + + + align:start position:0% +so yeah today's talk is on computational +imaging which as you'll see + + align:start position:0% +imaging which as you'll see + + + align:start position:0% +imaging which as you'll see +there's a lot of inspiration you can + + align:start position:0% +there's a lot of inspiration you can + + + align:start position:0% +there's a lot of inspiration you can +take from this work and i just like to + + align:start position:0% +take from this work and i just like to + + + align:start position:0% +take from this work and i just like to +mention a lot of these slides came from + + align:start position:0% +mention a lot of these slides came from + + + align:start position:0% +mention a lot of these slides came from +our which is graph course so if you want + + align:start position:0% +our which is graph course so if you want + + + align:start position:0% +our which is graph course so if you want +any more detail go to his website and + + align:start position:0% +any more detail go to his website and + + + align:start position:0% +any more detail go to his website and +you can actually see the original uh + + align:start position:0% +you can actually see the original uh + + + align:start position:0% +you can actually see the original uh +course material for this + + align:start position:0% +course material for this + + + align:start position:0% +course material for this +so the basic idea is that + + align:start position:0% +so the basic idea is that + + + align:start position:0% +so the basic idea is that +science is really driven by our + + align:start position:0% +science is really driven by our + + + align:start position:0% +science is really driven by our +technology this is not surprising anyone + + align:start position:0% +technology this is not surprising anyone + + + align:start position:0% +technology this is not surprising anyone +in the room you know the classic example + + align:start position:0% +in the room you know the classic example + + + align:start position:0% +in the room you know the classic example +marco boyd put here is that you know if + + align:start position:0% +marco boyd put here is that you know if + + + align:start position:0% +marco boyd put here is that you know if +you have low end hoof plus microscope + + align:start position:0% +you have low end hoof plus microscope + + + align:start position:0% +you have low end hoof plus microscope +equals microbiology and so really in + + align:start position:0% +equals microbiology and so really in + + + align:start position:0% +equals microbiology and so really in +some sense in the sciences you're + + align:start position:0% +some sense in the sciences you're + + + align:start position:0% +some sense in the sciences you're +waiting around for new technology to + + align:start position:0% +waiting around for new technology to + + + align:start position:0% +waiting around for new technology to +make new discoveries right we're waiting + + align:start position:0% +make new discoveries right we're waiting + + + align:start position:0% +make new discoveries right we're waiting +to put satellites up we're waiting for + + align:start position:0% +to put satellites up we're waiting for + + + align:start position:0% +to put satellites up we're waiting for +birds to stop ruining the large hadron + + align:start position:0% +birds to stop ruining the large hadron + + + align:start position:0% +birds to stop ruining the large hadron +collider right technology is what we're + + align:start position:0% +collider right technology is what we're + + + align:start position:0% +collider right technology is what we're +waiting for + + align:start position:0% +waiting for + + + align:start position:0% +waiting for +and so the question mark avoid ask is + + align:start position:0% +and so the question mark avoid ask is + + + align:start position:0% +and so the question mark avoid ask is +what's the most important instrument in + + align:start position:0% +what's the most important instrument in + + + align:start position:0% +what's the most important instrument in +the last century you know arguably in + + align:start position:0% +the last century you know arguably in + + + align:start position:0% +the last century you know arguably in +terms of science you know what would + + align:start position:0% +terms of science you know what would + + + align:start position:0% +terms of science you know what would +some people put up you could only choose + + align:start position:0% +some people put up you could only choose + + + align:start position:0% +some people put up you could only choose +one thing to take with you on desert + + align:start position:0% +one thing to take with you on desert + + + align:start position:0% +one thing to take with you on desert +desert island where they do science what + + align:start position:0% +desert island where they do science what + + + align:start position:0% +desert island where they do science what +would you take + + align:start position:0% +would you take + + + align:start position:0% +would you take +microwave computers + + align:start position:0% +microwave computers + + + align:start position:0% +microwave computers +exactly you know this is this is not + + align:start position:0% +exactly you know this is this is not + + + align:start position:0% +exactly you know this is this is not +news to anyone that the computer is + + align:start position:0% +news to anyone that the computer is + + + align:start position:0% +news to anyone that the computer is +really arguably the greatest + + align:start position:0% +really arguably the greatest + + + align:start position:0% +really arguably the greatest +scientific device and so what can we + + align:start position:0% +scientific device and so what can we + + + align:start position:0% +scientific device and so what can we +really do with this so you know they + + align:start position:0% +really do with this so you know they + + + align:start position:0% +really do with this so you know they +asked + + align:start position:0% +asked + + + align:start position:0% +asked +just people + + align:start position:0% +just people + + + align:start position:0% +just people +in the general population + + align:start position:0% +in the general population + + + align:start position:0% +in the general population +which of them which is the most + + align:start position:0% +which of them which is the most + + + align:start position:0% +which of them which is the most +important technology that has changed + + align:start position:0% +important technology that has changed + + + align:start position:0% +important technology that has changed +their life + + align:start position:0% +their life + + + align:start position:0% +their life +and they said remote control + + align:start position:0% +and they said remote control + + + align:start position:0% +and they said remote control +and a microwave microwave or remote + + align:start position:0% +and a microwave microwave or remote + + + align:start position:0% +and a microwave microwave or remote +control microwave is the greatest + + align:start position:0% +control microwave is the greatest + + + align:start position:0% +control microwave is the greatest +product + + align:start position:0% +product + + + align:start position:0% +product +so professor horn has said and this is + + align:start position:0% +so professor horn has said and this is + + + align:start position:0% +so professor horn has said and this is +of course very similar to the ideas of + + align:start position:0% +of course very similar to the ideas of + + + align:start position:0% +of course very similar to the ideas of +this class that computational imaging is + + align:start position:0% +this class that computational imaging is + + + align:start position:0% +this class that computational imaging is +simply imaging methods in which + + align:start position:0% +simply imaging methods in which + + + align:start position:0% +simply imaging methods in which +computation is inherent in image + + align:start position:0% +computation is inherent in image + + + align:start position:0% +computation is inherent in image +formation and so when we look at medical + + align:start position:0% +formation and so when we look at medical + + + align:start position:0% +formation and so when we look at medical +imaging and scientific imaging really + + align:start position:0% +imaging and scientific imaging really + + + align:start position:0% +imaging and scientific imaging really +this is the key story in the 20th + + align:start position:0% +this is the key story in the 20th + + + align:start position:0% +this is the key story in the 20th +century and so in some of this talk i'll + + align:start position:0% +century and so in some of this talk i'll + + + align:start position:0% +century and so in some of this talk i'll +show you what the modern way is to take + + align:start position:0% +show you what the modern way is to take + + + align:start position:0% +show you what the modern way is to take +some sort of image say using computer + + align:start position:0% +some sort of image say using computer + + + align:start position:0% +some sort of image say using computer +tomography and i'll show you how they + + align:start position:0% +tomography and i'll show you how they + + + align:start position:0% +tomography and i'll show you how they +did that 100 years ago before they had + + align:start position:0% +did that 100 years ago before they had + + + align:start position:0% +did that 100 years ago before they had +computing power how they did that using + + align:start position:0% +computing power how they did that using + + + align:start position:0% +computing power how they did that using +mechanical computing and so i think + + align:start position:0% +mechanical computing and so i think + + + align:start position:0% +mechanical computing and so i think +that's an interesting process to see how + + align:start position:0% +that's an interesting process to see how + + + align:start position:0% +that's an interesting process to see how +computation is really revolutionized how + + align:start position:0% +computation is really revolutionized how + + + align:start position:0% +computation is really revolutionized how +we take pictures in medicine and science + + align:start position:0% +we take pictures in medicine and science + + + align:start position:0% +we take pictures in medicine and science +and so then if we look out well beyond + + align:start position:0% +and so then if we look out well beyond + + + align:start position:0% +and so then if we look out well beyond +sort of the box we're in which is optics + + align:start position:0% +sort of the box we're in which is optics + + + align:start position:0% +sort of the box we're in which is optics +you know most of what we talk about + + align:start position:0% +you know most of what we talk about + + + align:start position:0% +you know most of what we talk about +coaching photography is this sort of + + align:start position:0% +coaching photography is this sort of + + + align:start position:0% +coaching photography is this sort of +wavefront coding like field photography + + align:start position:0% +wavefront coding like field photography + + + align:start position:0% +wavefront coding like field photography +holography things you've looked at in + + align:start position:0% +holography things you've looked at in + + + align:start position:0% +holography things you've looked at in +your homework if you open the box up a + + align:start position:0% +your homework if you open the box up a + + + align:start position:0% +your homework if you open the box up a +little bit these same ideas really come + + align:start position:0% +little bit these same ideas really come + + + align:start position:0% +little bit these same ideas really come +from a much more broader field and so + + align:start position:0% +from a much more broader field and so + + + align:start position:0% +from a much more broader field and so +the first part i'll talk about is + + align:start position:0% +the first part i'll talk about is + + + align:start position:0% +the first part i'll talk about is +medical imaging i think the key story in + + align:start position:0% +medical imaging i think the key story in + + + align:start position:0% +medical imaging i think the key story in +medical imaging is tomography really + + align:start position:0% +medical imaging is tomography really + + + align:start position:0% +medical imaging is tomography really +that's the central problem how do you + + align:start position:0% +that's the central problem how do you + + + align:start position:0% +that's the central problem how do you +take a cross-sectional image of an + + align:start position:0% +take a cross-sectional image of an + + + align:start position:0% +take a cross-sectional image of an +object non-invasively and you can do + + align:start position:0% +object non-invasively and you can do + + + align:start position:0% +object non-invasively and you can do +that in two ways you can use + + align:start position:0% +that in two ways you can use + + + align:start position:0% +that in two ways you can use +transmission or reflection tomography + + align:start position:0% +transmission or reflection tomography + + + align:start position:0% +transmission or reflection tomography +we'll talk about both and then that + + align:start position:0% +we'll talk about both and then that + + + align:start position:0% +we'll talk about both and then that +story is sort of repeated throughout the + + align:start position:0% +story is sort of repeated throughout the + + + align:start position:0% +story is sort of repeated throughout the +sciences once they understood tomography + + align:start position:0% +sciences once they understood tomography + + + align:start position:0% +sciences once they understood tomography +they said okay we can solve all these + + align:start position:0% +they said okay we can solve all these + + + align:start position:0% +they said okay we can solve all these +problems we can look at geophysics the + + align:start position:0% +problems we can look at geophysics the + + + align:start position:0% +problems we can look at geophysics the +exact same methodologies can be applied + + align:start position:0% +exact same methodologies can be applied + + + align:start position:0% +exact same methodologies can be applied +there which is really what's happening + + align:start position:0% +there which is really what's happening + + + align:start position:0% +there which is really what's happening +in optics now we've you know sort of in + + align:start position:0% +in optics now we've you know sort of in + + + align:start position:0% +in optics now we've you know sort of in +the late 90s they found this link + + align:start position:0% +the late 90s they found this link + + + align:start position:0% +the late 90s they found this link +between tomography and optics and then + + align:start position:0% +between tomography and optics and then + + + align:start position:0% +between tomography and optics and then +all of a sudden you had life build + + align:start position:0% +all of a sudden you had life build + + + align:start position:0% +all of a sudden you had life build +photography geophysics did that about in + + align:start position:0% +photography geophysics did that about in + + + align:start position:0% +photography geophysics did that about in +the 80s they discovered that link and + + align:start position:0% +the 80s they discovered that link and + + + align:start position:0% +the 80s they discovered that link and +they invented all of these methods + + align:start position:0% +they invented all of these methods + + + align:start position:0% +they invented all of these methods +for for unobtrusive measurement + + align:start position:0% +for for unobtrusive measurement + + + align:start position:0% +for for unobtrusive measurement +underground and then in applied physics + + align:start position:0% +underground and then in applied physics + + + align:start position:0% +underground and then in applied physics +we'll sort of talk about when the + + align:start position:0% +we'll sort of talk about when the + + + align:start position:0% +we'll sort of talk about when the +problems become much more difficult + + align:start position:0% +problems become much more difficult + + + align:start position:0% +problems become much more difficult +for light flow photography we look at + + align:start position:0% +for light flow photography we look at + + + align:start position:0% +for light flow photography we look at +ray optics once we start considering uh + + align:start position:0% +ray optics once we start considering uh + + + align:start position:0% +ray optics once we start considering uh +coherent optics or scattering tomography + + align:start position:0% +coherent optics or scattering tomography + + + align:start position:0% +coherent optics or scattering tomography +that's when the problems really get + + align:start position:0% +that's when the problems really get + + + align:start position:0% +that's when the problems really get +interesting i think for those of you + + align:start position:0% +interesting i think for those of you + + + align:start position:0% +interesting i think for those of you +working on final projects really looking + + align:start position:0% +working on final projects really looking + + + align:start position:0% +working on final projects really looking +at scattering tomography and it's linked + + align:start position:0% +at scattering tomography and it's linked + + + align:start position:0% +at scattering tomography and it's linked +to life of photography is where there's + + align:start position:0% +to life of photography is where there's + + + align:start position:0% +to life of photography is where there's +some exciting ideas and hopefully some + + align:start position:0% +some exciting ideas and hopefully some + + + align:start position:0% +some exciting ideas and hopefully some +of you are already thinking about that + + align:start position:0% +of you are already thinking about that + + + align:start position:0% +of you are already thinking about that +for your projects and then we'll we'll + + align:start position:0% +for your projects and then we'll we'll + + + align:start position:0% +for your projects and then we'll we'll +sort of jump away from tomography again + + align:start position:0% +sort of jump away from tomography again + + + align:start position:0% +sort of jump away from tomography again +i'm going to talk about all these things + + align:start position:0% +i'm going to talk about all these things + + + align:start position:0% +i'm going to talk about all these things +but then we'll move to something else + + align:start position:0% +but then we'll move to something else + + + align:start position:0% +but then we'll move to something else +which is really in biology the story + + align:start position:0% +which is really in biology the story + + + align:start position:0% +which is really in biology the story +isn't tomography + + align:start position:0% +isn't tomography + + + align:start position:0% +isn't tomography +necessarily it's again how he took a + + align:start position:0% +necessarily it's again how he took a + + + align:start position:0% +necessarily it's again how he took a +cross-sectional picture but the tricks + + align:start position:0% +cross-sectional picture but the tricks + + + align:start position:0% +cross-sectional picture but the tricks +are very different so we'll talk about + + align:start position:0% +are very different so we'll talk about + + + align:start position:0% +are very different so we'll talk about +confocal microscopy deconvolution uh + + align:start position:0% +confocal microscopy deconvolution uh + + + align:start position:0% +confocal microscopy deconvolution uh +debluring which some of you have + + align:start position:0% +debluring which some of you have + + + align:start position:0% +debluring which some of you have +probably seen already and if the final + + align:start position:0% +probably seen already and if the final + + + align:start position:0% +probably seen already and if the final +area i'll end up on is astronomy which + + align:start position:0% +area i'll end up on is astronomy which + + + align:start position:0% +area i'll end up on is astronomy which +is really where most of my work comes + + align:start position:0% +is really where most of my work comes + + + align:start position:0% +is really where most of my work comes +from is the idea many of these ideas + + align:start position:0% +from is the idea many of these ideas + + + align:start position:0% +from is the idea many of these ideas +especially in biological sciences + + align:start position:0% +especially in biological sciences + + + align:start position:0% +especially in biological sciences +involve refractive optics and then we'll + + align:start position:0% +involve refractive optics and then we'll + + + align:start position:0% +involve refractive optics and then we'll +look at how you can image without + + align:start position:0% +look at how you can image without + + + align:start position:0% +look at how you can image without +refraction and so again for x-rays gamma + + align:start position:0% +refraction and so again for x-rays gamma + + + align:start position:0% +refraction and so again for x-rays gamma +rays you can't build refractive optics + + align:start position:0% +rays you can't build refractive optics + + + align:start position:0% +rays you can't build refractive optics +and so then you get into the ideas of + + align:start position:0% +and so then you get into the ideas of + + + align:start position:0% +and so then you get into the ideas of +coded aperture imaging and + + align:start position:0% +coded aperture imaging and + + + align:start position:0% +coded aperture imaging and +interferometric imaging and then the + + align:start position:0% +interferometric imaging and then the + + + align:start position:0% +interferometric imaging and then the +rest of this is stuff you've already + + align:start position:0% +rest of this is stuff you've already + + + align:start position:0% +rest of this is stuff you've already +seen how do you build panoramas how do + + align:start position:0% +seen how do you build panoramas how do + + + align:start position:0% +seen how do you build panoramas how do +you take light field photographs + + align:start position:0% +you take light field photographs + + + align:start position:0% +you take light field photographs +and so really let's start which i think + + align:start position:0% +and so really let's start which i think + + + align:start position:0% +and so really let's start which i think +this is a great example of medical + + align:start position:0% +this is a great example of medical + + + align:start position:0% +this is a great example of medical +imaging and the idea of tomography and + + align:start position:0% +imaging and the idea of tomography and + + + align:start position:0% +imaging and the idea of tomography and +so + + align:start position:0% +so + + + align:start position:0% +so +the problem statement is very simple you + + align:start position:0% +the problem statement is very simple you + + + align:start position:0% +the problem statement is very simple you +want to non-invasively image inside of + + align:start position:0% +want to non-invasively image inside of + + + align:start position:0% +want to non-invasively image inside of +of of a living object and so of course + + align:start position:0% +of of a living object and so of course + + + align:start position:0% +of of a living object and so of course +any of you have been to the the ct + + align:start position:0% +any of you have been to the the ct + + + align:start position:0% +any of you have been to the the ct +scanner at the hospital you might have + + align:start position:0% +scanner at the hospital you might have + + + align:start position:0% +scanner at the hospital you might have +had them produce images like this so the + + align:start position:0% +had them produce images like this so the + + + align:start position:0% +had them produce images like this so the +question is how can you do this without + + align:start position:0% +question is how can you do this without + + + align:start position:0% +question is how can you do this without +simply slicing open a person and taking + + align:start position:0% +simply slicing open a person and taking + + + align:start position:0% +simply slicing open a person and taking +a photograph + + align:start position:0% +a photograph + + + align:start position:0% +a photograph +and so in general this involves + + align:start position:0% +and so in general this involves + + + align:start position:0% +and so in general this involves +basically taking the last hundred years + + align:start position:0% +basically taking the last hundred years + + + align:start position:0% +basically taking the last hundred years +of mathematics and solving an inverse + + align:start position:0% +of mathematics and solving an inverse + + + align:start position:0% +of mathematics and solving an inverse +problem we'll talk about what that + + align:start position:0% +problem we'll talk about what that + + + align:start position:0% +problem we'll talk about what that +inverse problem is then there's other + + align:start position:0% +inverse problem is then there's other + + + align:start position:0% +inverse problem is then there's other +ways instead of inverting a system you + + align:start position:0% +ways instead of inverting a system you + + + align:start position:0% +ways instead of inverting a system you +can of course use endoscopes thermal + + align:start position:0% +can of course use endoscopes thermal + + + align:start position:0% +can of course use endoscopes thermal +imaging microscopy to just simply + + align:start position:0% +imaging microscopy to just simply + + + align:start position:0% +imaging microscopy to just simply +directly measure inside the body + + align:start position:0% +directly measure inside the body + + + align:start position:0% +directly measure inside the body +and i think the key thing here is to + + align:start position:0% +and i think the key thing here is to + + + align:start position:0% +and i think the key thing here is to +notice that the mathematics behind + + align:start position:0% +notice that the mathematics behind + + + align:start position:0% +notice that the mathematics behind +tomography all of these devices are + + align:start position:0% +tomography all of these devices are + + + align:start position:0% +tomography all of these devices are +essentially the same ct scanners mri + + align:start position:0% +essentially the same ct scanners mri + + + align:start position:0% +essentially the same ct scanners mri +machines pet scanners ultrasound they + + align:start position:0% +machines pet scanners ultrasound they + + + align:start position:0% +machines pet scanners ultrasound they +all use the same underlying mathematics + + align:start position:0% +all use the same underlying mathematics + + + align:start position:0% +all use the same underlying mathematics +the only difference is the wavelength of + + align:start position:0% +the only difference is the wavelength of + + + align:start position:0% +the only difference is the wavelength of +radiation to zeroth order + + align:start position:0% +radiation to zeroth order + + + align:start position:0% +radiation to zeroth order +and of course the other main areas are + + align:start position:0% +and of course the other main areas are + + + align:start position:0% +and of course the other main areas are +eeg and meg + + align:start position:0% +eeg and meg + + + align:start position:0% +eeg and meg +and so if you think about designing a + + align:start position:0% +and so if you think about designing a + + + align:start position:0% +and so if you think about designing a +non-invasive medical device the first + + align:start position:0% +non-invasive medical device the first + + + align:start position:0% +non-invasive medical device the first +problem you have is ionizing radiation + + align:start position:0% +problem you have is ionizing radiation + + + align:start position:0% +problem you have is ionizing radiation +ct scanners use x-rays whereas mris use + + align:start position:0% +ct scanners use x-rays whereas mris use + + + align:start position:0% +ct scanners use x-rays whereas mris use +radio waves so that's the first major + + align:start position:0% +radio waves so that's the first major + + + align:start position:0% +radio waves so that's the first major +benefit but really the other problems to + + align:start position:0% +benefit but really the other problems to + + + align:start position:0% +benefit but really the other problems to +think about are again minimizing the + + align:start position:0% +think about are again minimizing the + + + align:start position:0% +think about are again minimizing the +invasiveness + + align:start position:0% +invasiveness + + + align:start position:0% +invasiveness +not inserting devices or probes and also + + align:start position:0% +not inserting devices or probes and also + + + align:start position:0% +not inserting devices or probes and also +improving temporal spatial resolution + + align:start position:0% +improving temporal spatial resolution + + + align:start position:0% +improving temporal spatial resolution +and finally making these things very + + align:start position:0% +and finally making these things very + + + align:start position:0% +and finally making these things very +inexpensive for the developing world + + align:start position:0% +inexpensive for the developing world + + + align:start position:0% +inexpensive for the developing world +and so now let's just jump into to what + + align:start position:0% +and so now let's just jump into to what + + + align:start position:0% +and so now let's just jump into to what +tomography is well it's a greek word + + align:start position:0% +tomography is well it's a greek word + + + align:start position:0% +tomography is well it's a greek word +greek origin and it's simply the word + + align:start position:0% +greek origin and it's simply the word + + + align:start position:0% +greek origin and it's simply the word +tomos or a section or cutting plus + + align:start position:0% +tomos or a section or cutting plus + + + align:start position:0% +tomos or a section or cutting plus +photography graphic taking a picture so + + align:start position:0% +photography graphic taking a picture so + + + align:start position:0% +photography graphic taking a picture so +it's a cross-sectional picture of an + + align:start position:0% +it's a cross-sectional picture of an + + + align:start position:0% +it's a cross-sectional picture of an +object so if you have some volumetric + + align:start position:0% +object so if you have some volumetric + + + align:start position:0% +object so if you have some volumetric +function in 3d tomography will take a + + align:start position:0% +function in 3d tomography will take a + + + align:start position:0% +function in 3d tomography will take a +slice of that 3d function and return a + + align:start position:0% +slice of that 3d function and return a + + + align:start position:0% +slice of that 3d function and return a +2d image that's our goal the question is + + align:start position:0% +2d image that's our goal the question is + + + align:start position:0% +2d image that's our goal the question is +how exactly can we do that + + align:start position:0% +how exactly can we do that + + + align:start position:0% +how exactly can we do that +non-invasively and it's a very simple + + align:start position:0% +non-invasively and it's a very simple + + + align:start position:0% +non-invasively and it's a very simple +idea the idea is to this is what i'm + + align:start position:0% +idea the idea is to this is what i'm + + + align:start position:0% +idea the idea is to this is what i'm +describing is known as transmission + + align:start position:0% +describing is known as transmission + + + align:start position:0% +describing is known as transmission +tomography there's also reflection to + + align:start position:0% +tomography there's also reflection to + + + align:start position:0% +tomography there's also reflection to +moderate people we'll get to that later + + align:start position:0% +moderate people we'll get to that later + + + align:start position:0% +moderate people we'll get to that later +so the idea of transmission tomography + + align:start position:0% +so the idea of transmission tomography + + + align:start position:0% +so the idea of transmission tomography +is we have some density function let's + + align:start position:0% +is we have some density function let's + + + align:start position:0% +is we have some density function let's +say our human body and it absorbs + + align:start position:0% +say our human body and it absorbs + + + align:start position:0% +say our human body and it absorbs +electromagnetic radiation and so we're + + align:start position:0% +electromagnetic radiation and so we're + + + align:start position:0% +electromagnetic radiation and so we're +going to put a single point source + + align:start position:0% +going to put a single point source + + + align:start position:0% +going to put a single point source +in the scene say like an x-ray source + + align:start position:0% +in the scene say like an x-ray source + + + align:start position:0% +in the scene say like an x-ray source +have it emit isotropically into the + + align:start position:0% +have it emit isotropically into the + + + align:start position:0% +have it emit isotropically into the +world and put a film plane sensitive to + + align:start position:0% +world and put a film plane sensitive to + + + align:start position:0% +world and put a film plane sensitive to +x-rays on one side of the object and our + + align:start position:0% +x-rays on one side of the object and our + + + align:start position:0% +x-rays on one side of the object and our +hope is that some wavelength of + + align:start position:0% +hope is that some wavelength of + + + align:start position:0% +hope is that some wavelength of +radiation that we can find + + align:start position:0% +radiation that we can find + + + align:start position:0% +radiation that we can find +will transmit ballistically through the + + align:start position:0% +will transmit ballistically through the + + + align:start position:0% +will transmit ballistically through the +object so it'll be little scattering but + + align:start position:0% +object so it'll be little scattering but + + + align:start position:0% +object so it'll be little scattering but +absorption so along a given ray from the + + align:start position:0% +absorption so along a given ray from the + + + align:start position:0% +absorption so along a given ray from the +source to our foam plane + + align:start position:0% +source to our foam plane + + + align:start position:0% +source to our foam plane +the electromagnetic creation the + + align:start position:0% +the electromagnetic creation the + + + align:start position:0% +the electromagnetic creation the +photonics if you will will simply travel + + align:start position:0% +photonics if you will will simply travel + + + align:start position:0% +photonics if you will will simply travel +through the object and the only thing + + align:start position:0% +through the object and the only thing + + + align:start position:0% +through the object and the only thing +that happens is that they're attenuated + + align:start position:0% +that happens is that they're attenuated + + + align:start position:0% +that happens is that they're attenuated +somewhat by the object that's our + + align:start position:0% +somewhat by the object that's our + + + align:start position:0% +somewhat by the object that's our +assumption now of course in the visible + + align:start position:0% +assumption now of course in the visible + + + align:start position:0% +assumption now of course in the visible +wavelength that's not true for human + + align:start position:0% +wavelength that's not true for human + + + align:start position:0% +wavelength that's not true for human +bodies you can't do this and so that's + + align:start position:0% +bodies you can't do this and so that's + + + align:start position:0% +bodies you can't do this and so that's +why they chose x-rays + + align:start position:0% +why they chose x-rays + + + align:start position:0% +why they chose x-rays +because that's easy to generate easy to + + align:start position:0% +because that's easy to generate easy to + + + align:start position:0% +because that's easy to generate easy to +build detectors and for the most part + + align:start position:0% +build detectors and for the most part + + + align:start position:0% +build detectors and for the most part +human bodies + + align:start position:0% +human bodies + + + align:start position:0% +human bodies +satisfy the scattering assumptions and + + align:start position:0% +satisfy the scattering assumptions and + + + align:start position:0% +satisfy the scattering assumptions and +so if you look back at ct scanner + + align:start position:0% +so if you look back at ct scanner + + + align:start position:0% +so if you look back at ct scanner +history if we go back 30 to 40 years + + align:start position:0% +history if we go back 30 to 40 years + + + align:start position:0% +history if we go back 30 to 40 years +really you have two technologies sort of + + align:start position:0% +really you have two technologies sort of + + + align:start position:0% +really you have two technologies sort of +competing against each other but the the + + align:start position:0% +competing against each other but the the + + + align:start position:0% +competing against each other but the the +basic idea is the same we're going to + + align:start position:0% +basic idea is the same we're going to + + + align:start position:0% +basic idea is the same we're going to +have some volumetric function like our + + align:start position:0% +have some volumetric function like our + + + align:start position:0% +have some volumetric function like our +body and we're going to take many + + align:start position:0% +body and we're going to take many + + + align:start position:0% +body and we're going to take many +projections of it right because we're + + align:start position:0% +projections of it right because we're + + + align:start position:0% +projections of it right because we're +trying to estimate a three-dimensional + + align:start position:0% +trying to estimate a three-dimensional + + + align:start position:0% +trying to estimate a three-dimensional +function we need to make a well-posed + + align:start position:0% +function we need to make a well-posed + + + align:start position:0% +function we need to make a well-posed +system to inverse so we need to somehow + + align:start position:0% +system to inverse so we need to somehow + + + align:start position:0% +system to inverse so we need to somehow +sample the variation so a single picture + + align:start position:0% +sample the variation so a single picture + + + align:start position:0% +sample the variation so a single picture +will only take a two-dimensional + + align:start position:0% +will only take a two-dimensional + + + align:start position:0% +will only take a two-dimensional +projection but then if we move the + + align:start position:0% +projection but then if we move the + + + align:start position:0% +projection but then if we move the +source to a new position we'll get a new + + align:start position:0% +source to a new position we'll get a new + + + align:start position:0% +source to a new position we'll get a new +projection if we take a full set of + + align:start position:0% +projection if we take a full set of + + + align:start position:0% +projection if we take a full set of +projections we hope that there's enough + + align:start position:0% +projections we hope that there's enough + + + align:start position:0% +projections we hope that there's enough +data to invert that system and we'll see + + align:start position:0% +data to invert that system and we'll see + + + align:start position:0% +data to invert that system and we'll see +how you do that but really before they + + align:start position:0% +how you do that but really before they + + + align:start position:0% +how you do that but really before they +invented + + align:start position:0% +invented + + + align:start position:0% +invented +the fan simple fan beam tomography there + + align:start position:0% +the fan simple fan beam tomography there + + + align:start position:0% +the fan simple fan beam tomography there +was actually a competing idea that's the + + align:start position:0% +was actually a competing idea that's the + + + align:start position:0% +was actually a competing idea that's the +reason it became popular is the + + align:start position:0% +reason it became popular is the + + + align:start position:0% +reason it became popular is the +mathematical inversion is actually + + align:start position:0% +mathematical inversion is actually + + + align:start position:0% +mathematical inversion is actually +easier and the idea is that + + align:start position:0% +easier and the idea is that + + + align:start position:0% +easier and the idea is that +instead of creating an x-ray point + + align:start position:0% +instead of creating an x-ray point + + + align:start position:0% +instead of creating an x-ray point +source + + align:start position:0% +source + + + align:start position:0% +source +we say have some some cathode 2 that + + align:start position:0% +we say have some some cathode 2 that + + + align:start position:0% +we say have some some cathode 2 that +generates x-rays and then we collimate + + align:start position:0% +generates x-rays and then we collimate + + + align:start position:0% +generates x-rays and then we collimate +them say with a series of lead fans and + + align:start position:0% +them say with a series of lead fans and + + + align:start position:0% +them say with a series of lead fans and +then we get a set of parallel beams so + + align:start position:0% +then we get a set of parallel beams so + + + align:start position:0% +then we get a set of parallel beams so +this is a parallel beam democracy + + align:start position:0% +this is a parallel beam democracy + + + align:start position:0% +this is a parallel beam democracy +problem which is really the easiest one + + align:start position:0% +problem which is really the easiest one + + + align:start position:0% +problem which is really the easiest one +to solve mathematically + + align:start position:0% +to solve mathematically + + + align:start position:0% +to solve mathematically +but now that we have plenty of computing + + align:start position:0% +but now that we have plenty of computing + + + align:start position:0% +but now that we have plenty of computing +power it's very easy to solve this + + align:start position:0% +power it's very easy to solve this + + + align:start position:0% +power it's very easy to solve this +system which is easier to build + + align:start position:0% +system which is easier to build + + + align:start position:0% +system which is easier to build +mechanically which is to simply have + + align:start position:0% +mechanically which is to simply have + + + align:start position:0% +mechanically which is to simply have +point x resources rotating around the + + align:start position:0% +point x resources rotating around the + + + align:start position:0% +point x resources rotating around the +patient so that's our data set simply a + + align:start position:0% +patient so that's our data set simply a + + + align:start position:0% +patient so that's our data set simply a +set of projections so now we have a + + align:start position:0% +set of projections so now we have a + + + align:start position:0% +set of projections so now we have a +mathematical problem it's very simple + + align:start position:0% +mathematical problem it's very simple + + + align:start position:0% +mathematical problem it's very simple +there's some underlying density function + + align:start position:0% +there's some underlying density function + + + align:start position:0% +there's some underlying density function +and so again array is going to pass + + align:start position:0% +and so again array is going to pass + + + align:start position:0% +and so again array is going to pass +through this density function you + + align:start position:0% +through this density function you + + + align:start position:0% +through this density function you +evaluate the line integral and that will + + align:start position:0% +evaluate the line integral and that will + + + align:start position:0% +evaluate the line integral and that will +be the absorption and our task is to + + align:start position:0% +be the absorption and our task is to + + + align:start position:0% +be the absorption and our task is to +invert that those set of line integrals + + align:start position:0% +invert that those set of line integrals + + + align:start position:0% +invert that those set of line integrals +to recover the density function + + align:start position:0% +to recover the density function + + + align:start position:0% +to recover the density function +so if you just take the case of the + + align:start position:0% +so if you just take the case of the + + + align:start position:0% +so if you just take the case of the +simple fan beam projection we have an + + align:start position:0% +simple fan beam projection we have an + + + align:start position:0% +simple fan beam projection we have an +x-ray source that's collimated a foam + + align:start position:0% +x-ray source that's collimated a foam + + + align:start position:0% +x-ray source that's collimated a foam +plane on the opposite side and rotates + + align:start position:0% +plane on the opposite side and rotates + + + align:start position:0% +plane on the opposite side and rotates +180 degrees around the patient and that + + align:start position:0% +180 degrees around the patient and that + + + align:start position:0% +180 degrees around the patient and that +gives you what's known as the radon + + align:start position:0% +gives you what's known as the radon + + + align:start position:0% +gives you what's known as the radon +transform maybe this is sounding + + align:start position:0% +transform maybe this is sounding + + + align:start position:0% +transform maybe this is sounding +familiar to a lot of those in the room + + align:start position:0% +familiar to a lot of those in the room + + + align:start position:0% +familiar to a lot of those in the room +so this radon transform again + + align:start position:0% +so this radon transform again + + + align:start position:0% +so this radon transform again +is simply the crop the projection of the + + align:start position:0% +is simply the crop the projection of the + + + align:start position:0% +is simply the crop the projection of the +density function along a given direction + + align:start position:0% +density function along a given direction + + + align:start position:0% +density function along a given direction +so this is the data set that a ct + + align:start position:0% +so this is the data set that a ct + + + align:start position:0% +so this is the data set that a ct +scanner will give you for the most part + + align:start position:0% +scanner will give you for the most part + + + align:start position:0% +scanner will give you for the most part +and then if you compare that to fan beam + + align:start position:0% +and then if you compare that to fan beam + + + align:start position:0% +and then if you compare that to fan beam +projection where you can imagine i'm + + align:start position:0% +projection where you can imagine i'm + + + align:start position:0% +projection where you can imagine i'm +putting + + align:start position:0% +putting + + + align:start position:0% +putting +a point source say the corner and then + + align:start position:0% +a point source say the corner and then + + + align:start position:0% +a point source say the corner and then +rotating it for the most part it looks + + align:start position:0% +rotating it for the most part it looks + + + align:start position:0% +rotating it for the most part it looks +almost identical it's just this slight + + align:start position:0% +almost identical it's just this slight + + + align:start position:0% +almost identical it's just this slight +nonlinear transformation of the parallel + + align:start position:0% +nonlinear transformation of the parallel + + + align:start position:0% +nonlinear transformation of the parallel +beam projection and so now that we have + + align:start position:0% +beam projection and so now that we have + + + align:start position:0% +beam projection and so now that we have +ample computing power it's very easy to + + align:start position:0% +ample computing power it's very easy to + + + align:start position:0% +ample computing power it's very easy to +re-sample this data set to be equivalent + + align:start position:0% +re-sample this data set to be equivalent + + + align:start position:0% +re-sample this data set to be equivalent +and then use the red inverse radar + + align:start position:0% +and then use the red inverse radar + + + align:start position:0% +and then use the red inverse radar +transform to solve but we still don't + + align:start position:0% +transform to solve but we still don't + + + align:start position:0% +transform to solve but we still don't +know how to invert this problem if i + + align:start position:0% +know how to invert this problem if i + + + align:start position:0% +know how to invert this problem if i +give you this image what algorithm can + + align:start position:0% +give you this image what algorithm can + + + align:start position:0% +give you this image what algorithm can +you apply to recover the original image + + align:start position:0% +you apply to recover the original image + + + align:start position:0% +you apply to recover the original image +so that's really where the insight was + + align:start position:0% +so that's really where the insight was + + + align:start position:0% +so that's really where the insight was +and so i'd recommend make sure + + align:start position:0% +and so i'd recommend make sure + + + align:start position:0% +and so i'd recommend make sure +everybody's up to us with us on the + + align:start position:0% +everybody's up to us with us on the + + + align:start position:0% +everybody's up to us with us on the +forward process + + align:start position:0% +forward process + + + align:start position:0% +forward process +is everybody clear how you go from the + + align:start position:0% +is everybody clear how you go from the + + + align:start position:0% +is everybody clear how you go from the +first image to the second image + + align:start position:0% +first image to the second image + + + align:start position:0% +first image to the second image +right + + align:start position:0% +right + + + align:start position:0% +right +now yes first one to second that's the + + align:start position:0% +now yes first one to second that's the + + + align:start position:0% +now yes first one to second that's the +easiest one + + align:start position:0% + + + + align:start position:0% + +is that clear i mean just a mechanic is + + align:start position:0% +is that clear i mean just a mechanic is + + + align:start position:0% +is that clear i mean just a mechanic is +very easy to simulate imagine + + align:start position:0% +very easy to simulate imagine + + + align:start position:0% +very easy to simulate imagine +imagine this line is our collimated + + align:start position:0% +imagine this line is our collimated + + + align:start position:0% +imagine this line is our collimated +x-ray source so it's just emitting + + align:start position:0% +x-ray source so it's just emitting + + + align:start position:0% +x-ray source so it's just emitting +parallel rays along the y-axis + + align:start position:0% +parallel rays along the y-axis + + + align:start position:0% +parallel rays along the y-axis +and this is our film plane + + align:start position:0% +and this is our film plane + + + align:start position:0% +and this is our film plane +and so if i just simulate the light + + align:start position:0% +and so if i just simulate the light + + + align:start position:0% +and so if i just simulate the light +going through here along given ray i + + align:start position:0% +going through here along given ray i + + + align:start position:0% +going through here along given ray i +perform the line integral + + align:start position:0% +perform the line integral + + + align:start position:0% +perform the line integral +of this function that gives me the + + align:start position:0% +of this function that gives me the + + + align:start position:0% +of this function that gives me the +absorption along that ray so a given ray + + align:start position:0% +absorption along that ray so a given ray + + + align:start position:0% +absorption along that ray so a given ray +would be some rotation angle and + + align:start position:0% +would be some rotation angle and + + + align:start position:0% +would be some rotation angle and +position so the first column of that + + align:start position:0% +position so the first column of that + + + align:start position:0% +position so the first column of that +middle image is the first parallel beam + + align:start position:0% +middle image is the first parallel beam + + + align:start position:0% +middle image is the first parallel beam +projection + + align:start position:0% +projection + + + align:start position:0% +projection +and then we'd rotate + + align:start position:0% +and then we'd rotate + + + align:start position:0% +and then we'd rotate +both of these slightly + + align:start position:0% +both of these slightly + + + align:start position:0% +both of these slightly +say in 90 degrees that would bring us + + align:start position:0% +say in 90 degrees that would bring us + + + align:start position:0% +say in 90 degrees that would bring us +already here we take another projection + + align:start position:0% +already here we take another projection + + + align:start position:0% +already here we take another projection +and we just get the series of + + align:start position:0% +and we just get the series of + + + align:start position:0% +and we just get the series of +projections as a function of angle do + + align:start position:0% +projections as a function of angle do + + + align:start position:0% +projections as a function of angle do +you have the moving chance uh i don't + + align:start position:0% +you have the moving chance uh i don't + + + align:start position:0% +you have the moving chance uh i don't +have a movie in this one no the the yeah + + align:start position:0% +have a movie in this one no the the yeah + + + align:start position:0% +have a movie in this one no the the yeah +we'll get to it at the end i should put + + align:start position:0% +we'll get to it at the end i should put + + + align:start position:0% +we'll get to it at the end i should put +that earlier + + align:start position:0% +that earlier + + + align:start position:0% +that earlier +um and so then the fan made projection + + align:start position:0% +um and so then the fan made projection + + + align:start position:0% +um and so then the fan made projection +is very simple to simulate as well + + align:start position:0% +is very simple to simulate as well + + + align:start position:0% +is very simple to simulate as well +instead of a line source we have a point + + align:start position:0% +instead of a line source we have a point + + + align:start position:0% +instead of a line source we have a point +source in this corner + + align:start position:0% +source in this corner + + + align:start position:0% +source in this corner +or say in the center here and we we have + + align:start position:0% +or say in the center here and we we have + + + align:start position:0% +or say in the center here and we we have +a set of fan beams going out and then we + + align:start position:0% +a set of fan beams going out and then we + + + align:start position:0% +a set of fan beams going out and then we +rotate those too which is why you get + + align:start position:0% +rotate those too which is why you get + + + align:start position:0% +rotate those too which is why you get +this non-linear transformation so that's + + align:start position:0% +this non-linear transformation so that's + + + align:start position:0% +this non-linear transformation so that's +our input data set now we're trying to + + align:start position:0% +our input data set now we're trying to + + + align:start position:0% +our input data set now we're trying to +invert the system and go from one of the + + align:start position:0% +invert the system and go from one of the + + + align:start position:0% +invert the system and go from one of the +the right images back to the original it + + align:start position:0% +the right images back to the original it + + + align:start position:0% +the right images back to the original it +is a common problem in a lot of + + align:start position:0% +is a common problem in a lot of + + + align:start position:0% +is a common problem in a lot of +conventional imaging situations right + + align:start position:0% +conventional imaging situations right + + + align:start position:0% +conventional imaging situations right +because as uh as duck said you want to + + align:start position:0% +because as uh as duck said you want to + + + align:start position:0% +because as uh as duck said you want to +you don't want to slice the patient + + align:start position:0% +you don't want to slice the patient + + + align:start position:0% +you don't want to slice the patient +so all your observations are from + + align:start position:0% +so all your observations are from + + + align:start position:0% +so all your observations are from +outside + + align:start position:0% +outside + + + align:start position:0% +outside +but you want to infer what's inside + + align:start position:0% +but you want to infer what's inside + + + align:start position:0% +but you want to infer what's inside +so from external observations + + align:start position:0% +so from external observations + + + align:start position:0% +so from external observations +you want to infer what's internal to the + + align:start position:0% +you want to infer what's internal to the + + + align:start position:0% +you want to infer what's internal to the +patient or to an object + + align:start position:0% +patient or to an object + + + align:start position:0% +patient or to an object +or to a oil well + + align:start position:0% + + + + align:start position:0% + +right so now we'll go into the map which + + align:start position:0% +right so now we'll go into the map which + + + align:start position:0% +right so now we'll go into the map which +there's really one nice result and again + + align:start position:0% +there's really one nice result and again + + + align:start position:0% +there's really one nice result and again +if anyone's working on this you should + + align:start position:0% +if anyone's working on this you should + + + align:start position:0% +if anyone's working on this you should +really look at slanted slanting and cat + + align:start position:0% +really look at slanted slanting and cat + + + align:start position:0% +really look at slanted slanting and cat +they have a really nice book that's + + align:start position:0% +they have a really nice book that's + + + align:start position:0% +they have a really nice book that's +online i think it's out of print now but + + align:start position:0% +online i think it's out of print now but + + + align:start position:0% +online i think it's out of print now but +you can the whole book is online and + + align:start position:0% +you can the whole book is online and + + + align:start position:0% +you can the whole book is online and +these figures are there but really the + + align:start position:0% +these figures are there but really the + + + align:start position:0% +these figures are there but really the +core idea behind this and you've + + align:start position:0% +core idea behind this and you've + + + align:start position:0% +core idea behind this and you've +probably seen this in your own homeworks + + align:start position:0% +probably seen this in your own homeworks + + + align:start position:0% +probably seen this in your own homeworks +on in light field photography i think + + align:start position:0% +on in light field photography i think + + + align:start position:0% +on in light field photography i think +you did refocusing i'm guessing + + align:start position:0% +you did refocusing i'm guessing + + + align:start position:0% +you did refocusing i'm guessing +i don't know if you did foia domain + + align:start position:0% +i don't know if you did foia domain + + + align:start position:0% +i don't know if you did foia domain +refocusing or just + + align:start position:0% +refocusing or just + + + align:start position:0% +refocusing or just +okay so you did the shift and some + + align:start position:0% +okay so you did the shift and some + + + align:start position:0% +okay so you did the shift and some +refocusing and it turns out this is the + + align:start position:0% +refocusing and it turns out this is the + + + align:start position:0% +refocusing and it turns out this is the +first example again mark lavoy + + align:start position:0% +first example again mark lavoy + + + align:start position:0% +first example again mark lavoy +originally + + align:start position:0% +originally + + + align:start position:0% +originally +put these slides together and he had a + + align:start position:0% +put these slides together and he had a + + + align:start position:0% +put these slides together and he had a +very nice paper i think it's 2005 the + + align:start position:0% +very nice paper i think it's 2005 the + + + align:start position:0% +very nice paper i think it's 2005 the +thesis but the idea was that you know + + align:start position:0% +thesis but the idea was that you know + + + align:start position:0% +thesis but the idea was that you know +you for your lifestyle refocusing you + + align:start position:0% +you for your lifestyle refocusing you + + + align:start position:0% +you for your lifestyle refocusing you +did shift and sum which is computational + + align:start position:0% +did shift and sum which is computational + + + align:start position:0% +did shift and sum which is computational +expensive using the foid projection + + align:start position:0% +expensive using the foid projection + + + align:start position:0% +expensive using the foid projection +slice theorem you can actually improve + + align:start position:0% +slice theorem you can actually improve + + + align:start position:0% +slice theorem you can actually improve +uh the running time of that algorithm + + align:start position:0% +uh the running time of that algorithm + + + align:start position:0% +uh the running time of that algorithm +you'll probably see that once we get + + align:start position:0% +you'll probably see that once we get + + + align:start position:0% +you'll probably see that once we get +through this but let's just let's just + + align:start position:0% +through this but let's just let's just + + + align:start position:0% +through this but let's just let's just +consider the tomography problem again we + + align:start position:0% +consider the tomography problem again we + + + align:start position:0% +consider the tomography problem again we +have this density function in 2d let's + + align:start position:0% +have this density function in 2d let's + + + align:start position:0% +have this density function in 2d let's +just analyze this in 2d to begin with so + + align:start position:0% +just analyze this in 2d to begin with so + + + align:start position:0% +just analyze this in 2d to begin with so +we have some density function of x + + align:start position:0% +we have some density function of x + + + align:start position:0% +we have some density function of x +x and y so this is our absorption + + align:start position:0% +x and y so this is our absorption + + + align:start position:0% +x and y so this is our absorption +function + + align:start position:0% +function + + + align:start position:0% +function +and then we're going to take a + + align:start position:0% +and then we're going to take a + + + align:start position:0% +and then we're going to take a +projection + + align:start position:0% +projection + + + align:start position:0% +projection +again this is a parallel beam projection + + align:start position:0% +again this is a parallel beam projection + + + align:start position:0% +again this is a parallel beam projection +along some angle and so if we're just + + align:start position:0% +along some angle and so if we're just + + + align:start position:0% +along some angle and so if we're just +projecting along y + + align:start position:0% +projecting along y + + + align:start position:0% +projecting along y +then the projection + + align:start position:0% +then the projection + + + align:start position:0% +then the projection +along y + + align:start position:0% +along y + + + align:start position:0% +along y +is simply the line the integral of this + + align:start position:0% +is simply the line the integral of this + + + align:start position:0% +is simply the line the integral of this +function over y right does that make + + align:start position:0% +function over y right does that make + + + align:start position:0% +function over y right does that make +sense so we're projecting this function + + align:start position:0% +sense so we're projecting this function + + + align:start position:0% +sense so we're projecting this function +onto the x-axis right that's our first + + align:start position:0% +onto the x-axis right that's our first + + + align:start position:0% +onto the x-axis right that's our first +that's that's obvious + + align:start position:0% +that's that's obvious + + + align:start position:0% +that's that's obvious +now the question is let's let's look at + + align:start position:0% +now the question is let's let's look at + + + align:start position:0% +now the question is let's let's look at +a four domain analysis of this problem + + align:start position:0% +a four domain analysis of this problem + + + align:start position:0% +a four domain analysis of this problem +so + + align:start position:0% +so + + + align:start position:0% +so +let's take the two dimensional fourier + + align:start position:0% +let's take the two dimensional fourier + + + align:start position:0% +let's take the two dimensional fourier +transform of our original density + + align:start position:0% +transform of our original density + + + align:start position:0% +transform of our original density +function and so you can write that it's + + align:start position:0% +function and so you can write that it's + + + align:start position:0% +function and so you can write that it's +very simple everyone remembers this the + + align:start position:0% +very simple everyone remembers this the + + + align:start position:0% +very simple everyone remembers this the +fourier transform function of the two + + align:start position:0% +fourier transform function of the two + + + align:start position:0% +fourier transform function of the two +frequency parameters is simply the + + align:start position:0% +frequency parameters is simply the + + + align:start position:0% +frequency parameters is simply the +original function times this complex + + align:start position:0% +original function times this complex + + + align:start position:0% +original function times this complex +exponential which is the sum of the + + align:start position:0% +exponential which is the sum of the + + + align:start position:0% +exponential which is the sum of the +coefficients in each direction + + align:start position:0% +coefficients in each direction + + + align:start position:0% +coefficients in each direction +and here's the key insight what we'd + + align:start position:0% +and here's the key insight what we'd + + + align:start position:0% +and here's the key insight what we'd +like to do is somehow relate the + + align:start position:0% +like to do is somehow relate the + + + align:start position:0% +like to do is somehow relate the +properties of this fourier transform to + + align:start position:0% +properties of this fourier transform to + + + align:start position:0% +properties of this fourier transform to +a slice in our primary domain and so + + align:start position:0% +a slice in our primary domain and so + + + align:start position:0% +a slice in our primary domain and so +this this is really the neat trick + + align:start position:0% +this this is really the neat trick + + + align:start position:0% +this this is really the neat trick +behind the toy projection slice there is + + align:start position:0% +behind the toy projection slice there is + + + align:start position:0% +behind the toy projection slice there is +let's just look + + align:start position:0% +let's just look + + + align:start position:0% +let's just look +at + + align:start position:0% +at + + + align:start position:0% +at +this 1d slice + + align:start position:0% +this 1d slice + + + align:start position:0% +this 1d slice +along the kx + + align:start position:0% +along the kx + + + align:start position:0% +along the kx +the f frequency axis + + align:start position:0% +the f frequency axis + + + align:start position:0% +the f frequency axis +in the foia domain and so that that's + + align:start position:0% +in the foia domain and so that that's + + + align:start position:0% +in the foia domain and so that that's +just given by substituting 0 for the y + + align:start position:0% +just given by substituting 0 for the y + + + align:start position:0% +just given by substituting 0 for the y +into our previous expression right so + + align:start position:0% +into our previous expression right so + + + align:start position:0% +into our previous expression right so +essentially this k x and k y can be + + align:start position:0% +essentially this k x and k y can be + + + align:start position:0% +essentially this k x and k y can be +thought of as a vector and we're just + + align:start position:0% +thought of as a vector and we're just + + + align:start position:0% +thought of as a vector and we're just +selecting the one along x and so here + + align:start position:0% +selecting the one along x and so here + + + align:start position:0% +selecting the one along x and so here +you see that our y term drops out + + align:start position:0% +you see that our y term drops out + + + align:start position:0% +you see that our y term drops out +and what this gives us is the flight + + align:start position:0% +and what this gives us is the flight + + + align:start position:0% +and what this gives us is the flight +transform along the kx axis right just + + align:start position:0% +transform along the kx axis right just + + + align:start position:0% +transform along the kx axis right just +the 1d slice + + align:start position:0% +the 1d slice + + + align:start position:0% +the 1d slice +so the next step is really where all the + + align:start position:0% +so the next step is really where all the + + + align:start position:0% +so the next step is really where all the +magic happens it's just regrouping terms + + align:start position:0% +magic happens it's just regrouping terms + + + align:start position:0% +magic happens it's just regrouping terms +in that integral so if you look at this + + align:start position:0% +in that integral so if you look at this + + + align:start position:0% +in that integral so if you look at this +you can see that it's separable and so + + align:start position:0% +you can see that it's separable and so + + + align:start position:0% +you can see that it's separable and so +we can do the y integration regroup it + + align:start position:0% +we can do the y integration regroup it + + + align:start position:0% +we can do the y integration regroup it +and then do the fourier transform and so + + align:start position:0% +and then do the fourier transform and so + + + align:start position:0% +and then do the fourier transform and so +now you can just substitute the first + + align:start position:0% +now you can just substitute the first + + + align:start position:0% +now you can just substitute the first +expression + + align:start position:0% +expression + + + align:start position:0% +expression +and you get this very nice result so can + + align:start position:0% +and you get this very nice result so can + + + align:start position:0% +and you get this very nice result so can +they do why interpret this you sort of + + align:start position:0% +they do why interpret this you sort of + + + align:start position:0% +they do why interpret this you sort of +you see what this means + + align:start position:0% +you see what this means + + + align:start position:0% +you see what this means +i can explain to you but it'd be nice to + + align:start position:0% +i can explain to you but it'd be nice to + + + align:start position:0% +i can explain to you but it'd be nice to +sort of see if people are following + + align:start position:0% +sort of see if people are following + + + align:start position:0% +sort of see if people are following +so remember we started with + + align:start position:0% +so remember we started with + + + align:start position:0% +so remember we started with +the first row is p of x which means + + align:start position:0% +the first row is p of x which means + + + align:start position:0% +the first row is p of x which means +it's the photo + + align:start position:0% +it's the photo + + + align:start position:0% +it's the photo +taken along the x direction right if you + + align:start position:0% +taken along the x direction right if you + + + align:start position:0% +taken along the x direction right if you +put a sensor + + align:start position:0% +put a sensor + + + align:start position:0% +put a sensor +um + + align:start position:0% +um + + + align:start position:0% +um +we get the px photo + + align:start position:0% +we get the px photo + + + align:start position:0% +we get the px photo +and then + + align:start position:0% +and then + + + align:start position:0% +and then +you go through the whole math + + align:start position:0% +you go through the whole math + + + align:start position:0% +you go through the whole math +the second equation is fourier transform + + align:start position:0% +the second equation is fourier transform + + + align:start position:0% +the second equation is fourier transform +third equation is fourier transform + + align:start position:0% +third equation is fourier transform + + + align:start position:0% +third equation is fourier transform +along uh is it along the y axis along + + align:start position:0% +along uh is it along the y axis along + + + align:start position:0% +along uh is it along the y axis along +dropping it just for your transform + + align:start position:0% +dropping it just for your transform + + + align:start position:0% +dropping it just for your transform +along x yeah along x + + align:start position:0% +along x yeah along x + + + align:start position:0% +along x yeah along x +and then but what you get back at the + + align:start position:0% +and then but what you get back at the + + + align:start position:0% +and then but what you get back at the +bottom + + align:start position:0% +bottom + + + align:start position:0% +bottom +is the px term which was the original + + align:start position:0% +is the px term which was the original + + + align:start position:0% +is the px term which was the original +photo that you started with + + align:start position:0% + + + + align:start position:0% + +right so so looking at this expression + + align:start position:0% +right so so looking at this expression + + + align:start position:0% +right so so looking at this expression +there's now this relationship between + + align:start position:0% +there's now this relationship between + + + align:start position:0% +there's now this relationship between +the frequency domain + + align:start position:0% +the frequency domain + + + align:start position:0% +the frequency domain +the fourier transform or density + + align:start position:0% +the fourier transform or density + + + align:start position:0% +the fourier transform or density +function in the original function do you + + align:start position:0% +function in the original function do you + + + align:start position:0% +function in the original function do you +see what that relationship is here + + align:start position:0% +see what that relationship is here + + + align:start position:0% +see what that relationship is here +what is this saying the slice is just + + align:start position:0% +what is this saying the slice is just + + + align:start position:0% +what is this saying the slice is just +the fourier transform of the original + + align:start position:0% +the fourier transform of the original + + + align:start position:0% +the fourier transform of the original +exactly very good so the fourier + + align:start position:0% +exactly very good so the fourier + + + align:start position:0% +exactly very good so the fourier +projection slice theorem this is the key + + align:start position:0% +projection slice theorem this is the key + + + align:start position:0% +projection slice theorem this is the key +insight is that if i take a 1d slice + + align:start position:0% +insight is that if i take a 1d slice + + + align:start position:0% +insight is that if i take a 1d slice +of my density function take its fourier + + align:start position:0% +of my density function take its fourier + + + align:start position:0% +of my density function take its fourier +transform 1d + + align:start position:0% +transform 1d + + + align:start position:0% +transform 1d +1d4 transform that's equal to a slice of + + align:start position:0% +1d4 transform that's equal to a slice of + + + align:start position:0% +1d4 transform that's equal to a slice of +the 2d4 transform + + align:start position:0% +the 2d4 transform + + + align:start position:0% +the 2d4 transform +okay so we have this inside so how could + + align:start position:0% +okay so we have this inside so how could + + + align:start position:0% +okay so we have this inside so how could +you use this to now solve our problem + + align:start position:0% +you use this to now solve our problem + + + align:start position:0% +you use this to now solve our problem +let's go back + + align:start position:0% +let's go back + + + align:start position:0% +let's go back +do you see how you could use this to now + + align:start position:0% +do you see how you could use this to now + + + align:start position:0% +do you see how you could use this to now +go from say this image which is a + + align:start position:0% +go from say this image which is a + + + align:start position:0% +go from say this image which is a +parallel beam projection back to the + + align:start position:0% +parallel beam projection back to the + + + align:start position:0% +parallel beam projection back to the +original density + + align:start position:0% +original density + + + align:start position:0% +original density +can anyone describe the algorithm + + align:start position:0% +can anyone describe the algorithm + + + align:start position:0% +can anyone describe the algorithm +roughly + + align:start position:0% +roughly + + + align:start position:0% +roughly +just take the us + + align:start position:0% + + + + align:start position:0% + +and then we construct all the + + align:start position:0% +and then we construct all the + + + align:start position:0% +and then we construct all the +slices of okay so + + align:start position:0% +slices of okay so + + + align:start position:0% +slices of okay so +so so okay here's your image what's the + + align:start position:0% +so so okay here's your image what's the + + + align:start position:0% +so so okay here's your image what's the +first step + + align:start position:0% +first step + + + align:start position:0% +first step +um take the line one line say every + + align:start position:0% +um take the line one line say every + + + align:start position:0% +um take the line one line say every +column here is a px okay + + align:start position:0% +column here is a px okay + + + align:start position:0% +column here is a px okay +great um and take all of them uh take + + align:start position:0% +great um and take all of them uh take + + + align:start position:0% +great um and take all of them uh take +their inverses inverse of the x inverse + + align:start position:0% +their inverses inverse of the x inverse + + + align:start position:0% +their inverses inverse of the x inverse +fourier transform the fourier transform + + align:start position:0% +fourier transform the fourier transform + + + align:start position:0% +fourier transform the fourier transform +yeah yeah + + align:start position:0% +yeah yeah + + + align:start position:0% +yeah yeah +and then you will get uh kx + + align:start position:0% +and then you will get uh kx + + + align:start position:0% +and then you will get uh kx +yes and then keep rotating all the cases + + align:start position:0% +yes and then keep rotating all the cases + + + align:start position:0% +yes and then keep rotating all the cases +to generate capital f that's absolutely + + align:start position:0% +to generate capital f that's absolutely + + + align:start position:0% +to generate capital f that's absolutely +correct great and then and then the last + + align:start position:0% +correct great and then and then the last + + + align:start position:0% +correct great and then and then the last +step + + align:start position:0% +step + + + align:start position:0% +step +exactly so let me just summarize that up + + align:start position:0% +exactly so let me just summarize that up + + + align:start position:0% +exactly so let me just summarize that up +that's great that's exactly what they do + + align:start position:0% +that's great that's exactly what they do + + + align:start position:0% +that's great that's exactly what they do +so the algorithm is very simple remember + + align:start position:0% +so the algorithm is very simple remember + + + align:start position:0% +so the algorithm is very simple remember +we're going to get a slice + + align:start position:0% +we're going to get a slice + + + align:start position:0% +we're going to get a slice +for each angle + + align:start position:0% +for each angle + + + align:start position:0% +for each angle +so so you simply take the projection + + align:start position:0% +so so you simply take the projection + + + align:start position:0% +so so you simply take the projection +take its 1d40 transform and assign + + align:start position:0% +take its 1d40 transform and assign + + + align:start position:0% +take its 1d40 transform and assign +initialize an accumulator it's all zeros + + align:start position:0% +initialize an accumulator it's all zeros + + + align:start position:0% +initialize an accumulator it's all zeros +assign the fourier transform then rotate + + align:start position:0% +assign the fourier transform then rotate + + + align:start position:0% +assign the fourier transform then rotate +your source receiver take a new slice + + align:start position:0% +your source receiver take a new slice + + + align:start position:0% +your source receiver take a new slice +one before you transform assign it and + + align:start position:0% +one before you transform assign it and + + + align:start position:0% +one before you transform assign it and +you're going to build up this whole + + align:start position:0% +you're going to build up this whole + + + align:start position:0% +you're going to build up this whole +space + + align:start position:0% +space + + + align:start position:0% +space +and after a full 180 degree rotation + + align:start position:0% +and after a full 180 degree rotation + + + align:start position:0% +and after a full 180 degree rotation +you'll have populated + + align:start position:0% +you'll have populated + + + align:start position:0% +you'll have populated +this entire volume + + align:start position:0% +this entire volume + + + align:start position:0% +this entire volume +and then you're gonna inversely + + align:start position:0% +and then you're gonna inversely + + + align:start position:0% +and then you're gonna inversely +transform and get get everything back so + + align:start position:0% +transform and get get everything back so + + + align:start position:0% +transform and get get everything back so +let's i think i have a picture here of + + align:start position:0% +let's i think i have a picture here of + + + align:start position:0% +let's i think i have a picture here of +how that works + + align:start position:0% +how that works + + + align:start position:0% +how that works +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +so you just described this algorithm + + align:start position:0% +so you just described this algorithm + + + align:start position:0% +so you just described this algorithm +correctly + + align:start position:0% +correctly + + + align:start position:0% +correctly +so + + align:start position:0% +so + + + align:start position:0% +so +so now you can see + + align:start position:0% +so now you can see + + + align:start position:0% +so now you can see +basically that procedure i outlined at + + align:start position:0% +basically that procedure i outlined at + + + align:start position:0% +basically that procedure i outlined at +each step we're going to populate our + + align:start position:0% +each step we're going to populate our + + + align:start position:0% +each step we're going to populate our +accumulator once it's full we can + + align:start position:0% +accumulator once it's full we can + + + align:start position:0% +accumulator once it's full we can +inverse 2d4 transform we get our image + + align:start position:0% +inverse 2d4 transform we get our image + + + align:start position:0% +inverse 2d4 transform we get our image +right so what are some problems you can + + align:start position:0% +right so what are some problems you can + + + align:start position:0% +right so what are some problems you can +see this is this is the textbook and + + align:start position:0% +see this is this is the textbook and + + + align:start position:0% +see this is this is the textbook and +there's the textbook again solution to + + align:start position:0% +there's the textbook again solution to + + + align:start position:0% +there's the textbook again solution to +the inverse radon transform so what are + + align:start position:0% +the inverse radon transform so what are + + + align:start position:0% +the inverse radon transform so what are +some limitations you can already see you + + align:start position:0% +some limitations you can already see you + + + align:start position:0% +some limitations you can already see you +know sort of practically if you built a + + align:start position:0% +know sort of practically if you built a + + + align:start position:0% +know sort of practically if you built a +ct scanner that used this algorithm what + + align:start position:0% +ct scanner that used this algorithm what + + + align:start position:0% +ct scanner that used this algorithm what +would be some of the limitations the + + align:start position:0% +would be some of the limitations the + + + align:start position:0% +would be some of the limitations the +resolution of the angles at which you + + align:start position:0% +resolution of the angles at which you + + + align:start position:0% +resolution of the angles at which you +can take exactly + + align:start position:0% +can take exactly + + + align:start position:0% +can take exactly +so so you see that the problem here is + + align:start position:0% +so so you see that the problem here is + + + align:start position:0% +so so you see that the problem here is +we need to fully populate + + align:start position:0% +we need to fully populate + + + align:start position:0% +we need to fully populate +this transform before we take we need to + + align:start position:0% +this transform before we take we need to + + + align:start position:0% +this transform before we take we need to +fully populate our 2d4 transform before + + align:start position:0% +fully populate our 2d4 transform before + + + align:start position:0% +fully populate our 2d4 transform before +we inverse transform or else we'll have + + align:start position:0% +we inverse transform or else we'll have + + + align:start position:0% +we inverse transform or else we'll have +missing data and artifacts does that + + align:start position:0% +missing data and artifacts does that + + + align:start position:0% +missing data and artifacts does that +make sense + + align:start position:0% +make sense + + + align:start position:0% +make sense +and so this this insight is really at + + align:start position:0% +and so this this insight is really at + + + align:start position:0% +and so this this insight is really at +the core of tomography you can see a lot + + align:start position:0% +the core of tomography you can see a lot + + + align:start position:0% +the core of tomography you can see a lot +of the limitations so the first one you + + align:start position:0% +of the limitations so the first one you + + + align:start position:0% +of the limitations so the first one you +mentioned + + align:start position:0% +mentioned + + + align:start position:0% +mentioned +is resolution + + align:start position:0% +is resolution + + + align:start position:0% +is resolution +right so you mean by angular resolution + + align:start position:0% +right so you mean by angular resolution + + + align:start position:0% +right so you mean by angular resolution +i think so if we built if we built a ct + + align:start position:0% +i think so if we built if we built a ct + + + align:start position:0% +i think so if we built if we built a ct +scanner that took a projection every + + align:start position:0% +scanner that took a projection every + + + align:start position:0% +scanner that took a projection every +five degrees + + align:start position:0% +five degrees + + + align:start position:0% +five degrees +right + + align:start position:0% +right + + + align:start position:0% +right +or every 20 degrees we have lots of + + align:start position:0% +or every 20 degrees we have lots of + + + align:start position:0% +or every 20 degrees we have lots of +zeros left in this data set if we take + + align:start position:0% +zeros left in this data set if we take + + + align:start position:0% +zeros left in this data set if we take +every 20 degrees you're filling up this + + align:start position:0% +every 20 degrees you're filling up this + + + align:start position:0% +every 20 degrees you're filling up this +this image only at every 20 degrees + + align:start position:0% +this image only at every 20 degrees + + + align:start position:0% +this image only at every 20 degrees +right 20 40 60 80 and so right so you + + align:start position:0% +right 20 40 60 80 and so right so you + + + align:start position:0% +right 20 40 60 80 and so right so you +can imagine they'll be huge near the + + align:start position:0% +can imagine they'll be huge near the + + + align:start position:0% +can imagine they'll be huge near the +origin you'll be okay your low frequency + + align:start position:0% +origin you'll be okay your low frequency + + + align:start position:0% +origin you'll be okay your low frequency +reconstruction will be all right but + + align:start position:0% +reconstruction will be all right but + + + align:start position:0% +reconstruction will be all right but +your high frequency detail will be lost + + align:start position:0% +your high frequency detail will be lost + + + align:start position:0% +your high frequency detail will be lost +right or unknown right you'll have many + + align:start position:0% +right or unknown right you'll have many + + + align:start position:0% +right or unknown right you'll have many +zeros out here + + align:start position:0% +zeros out here + + + align:start position:0% +zeros out here +so that already implies that cp scanners + + align:start position:0% +so that already implies that cp scanners + + + align:start position:0% +so that already implies that cp scanners +need to have very dense set of rotations + + align:start position:0% +need to have very dense set of rotations + + + align:start position:0% +need to have very dense set of rotations +or you need to have some prior about the + + align:start position:0% +or you need to have some prior about the + + + align:start position:0% +or you need to have some prior about the +scene but that's that's one problem + + align:start position:0% +scene but that's that's one problem + + + align:start position:0% +scene but that's that's one problem +what's what's another problem you can + + align:start position:0% +what's what's another problem you can + + + align:start position:0% +what's what's another problem you can +see + + align:start position:0% +see + + + align:start position:0% +see +so if i built a ct scanner for instance + + align:start position:0% +so if i built a ct scanner for instance + + + align:start position:0% +so if i built a ct scanner for instance +that could only scan a limited set of + + align:start position:0% +that could only scan a limited set of + + + align:start position:0% +that could only scan a limited set of +angles + + align:start position:0% +angles + + + align:start position:0% +angles +not a full 180 degree rotation + + align:start position:0% +not a full 180 degree rotation + + + align:start position:0% +not a full 180 degree rotation +right then you also have a lot of + + align:start position:0% +right then you also have a lot of + + + align:start position:0% +right then you also have a lot of +missing data here right + + align:start position:0% +missing data here right + + + align:start position:0% +missing data here right +and so that that's the second so having + + align:start position:0% +and so that that's the second so having + + + align:start position:0% +and so that that's the second so having +sufficient angular sampling is one + + align:start position:0% +sufficient angular sampling is one + + + align:start position:0% +sufficient angular sampling is one +problem of ct scanning the other is + + align:start position:0% +problem of ct scanning the other is + + + align:start position:0% +problem of ct scanning the other is +limited baseline if i only rotate over a + + align:start position:0% +limited baseline if i only rotate over a + + + align:start position:0% +limited baseline if i only rotate over a +small set of angles because maybe in + + align:start position:0% +small set of angles because maybe in + + + align:start position:0% +small set of angles because maybe in +whatever system i'm using it's difficult + + align:start position:0% +whatever system i'm using it's difficult + + + align:start position:0% +whatever system i'm using it's difficult +to rotate over a full 100 degree + + align:start position:0% +to rotate over a full 100 degree + + + align:start position:0% +to rotate over a full 100 degree +rotation then i won't be able to get a + + align:start position:0% +rotation then i won't be able to get a + + + align:start position:0% +rotation then i won't be able to get a +complete reconstruction + + align:start position:0% +complete reconstruction + + + align:start position:0% +complete reconstruction +so really keep in tune though keep in + + align:start position:0% +so really keep in tune though keep in + + + align:start position:0% +so really keep in tune though keep in +mind those two limitations of ct + + align:start position:0% +mind those two limitations of ct + + + align:start position:0% +mind those two limitations of ct +scanning you need to have sufficient + + align:start position:0% +scanning you need to have sufficient + + + align:start position:0% +scanning you need to have sufficient +angular density and sufficient baseline + + align:start position:0% +angular density and sufficient baseline + + + align:start position:0% +angular density and sufficient baseline +and they actually map directly to + + align:start position:0% +and they actually map directly to + + + align:start position:0% +and they actually map directly to +problems with lightfield cameras + + align:start position:0% +problems with lightfield cameras + + + align:start position:0% +problems with lightfield cameras +but then let's just look at the step + + align:start position:0% +but then let's just look at the step + + + align:start position:0% +but then let's just look at the step +back again and think about this + + align:start position:0% +back again and think about this + + + align:start position:0% +back again and think about this +so again + + align:start position:0% +so again + + + align:start position:0% +so again +our algorithm is we rotate our source + + align:start position:0% +our algorithm is we rotate our source + + + align:start position:0% +our algorithm is we rotate our source +and receiver around the object if it's + + align:start position:0% +and receiver around the object if it's + + + align:start position:0% +and receiver around the object if it's +fan meme or trello being tomography you + + align:start position:0% +fan meme or trello being tomography you + + + align:start position:0% +fan meme or trello being tomography you +sort of end up with the same thing where + + align:start position:0% +sort of end up with the same thing where + + + align:start position:0% +sort of end up with the same thing where +you take the voice the one these + + align:start position:0% +you take the voice the one these + + + align:start position:0% +you take the voice the one these +transforms and you assign them to the + + align:start position:0% +transforms and you assign them to the + + + align:start position:0% +transforms and you assign them to the +frequency domain and we may have some + + align:start position:0% +frequency domain and we may have some + + + align:start position:0% +frequency domain and we may have some +zeros but there's a third problem which + + align:start position:0% +zeros but there's a third problem which + + + align:start position:0% +zeros but there's a third problem which +i didn't describe and you can sort of + + align:start position:0% +i didn't describe and you can sort of + + + align:start position:0% +i didn't describe and you can sort of +see it here again the algorithm was we + + align:start position:0% +see it here again the algorithm was we + + + align:start position:0% +see it here again the algorithm was we +initialize an accumulator to all zeros + + align:start position:0% +initialize an accumulator to all zeros + + + align:start position:0% +initialize an accumulator to all zeros +we take the 1d40 transform add to the + + align:start position:0% +we take the 1d40 transform add to the + + + align:start position:0% +we take the 1d40 transform add to the +accumulator + + align:start position:0% +accumulator + + + align:start position:0% +accumulator +then rotate add the next one add the + + align:start position:0% +then rotate add the next one add the + + + align:start position:0% +then rotate add the next one add the +next one out of the next one you can see + + align:start position:0% +next one out of the next one you can see + + + align:start position:0% +next one out of the next one you can see +it right here with the opacity i made + + align:start position:0% +it right here with the opacity i made + + + align:start position:0% +it right here with the opacity i made +all of these equal and you can see we're + + align:start position:0% +all of these equal and you can see we're + + + align:start position:0% +all of these equal and you can see we're +building up this really high density in + + align:start position:0% +building up this really high density in + + + align:start position:0% +building up this really high density in +the center + + align:start position:0% +the center + + + align:start position:0% +the center +does that make sense and so when i + + align:start position:0% +does that make sense and so when i + + + align:start position:0% +does that make sense and so when i +inverse square i transform essentially + + align:start position:0% +inverse square i transform essentially + + + align:start position:0% +inverse square i transform essentially +my low frequency terms have been boosted + + align:start position:0% +my low frequency terms have been boosted + + + align:start position:0% +my low frequency terms have been boosted +right and so + + align:start position:0% +right and so + + + align:start position:0% +right and so +we'll lose edge contrast if we don't do + + align:start position:0% +we'll lose edge contrast if we don't do + + + align:start position:0% +we'll lose edge contrast if we don't do +anything here right so the third problem + + align:start position:0% +anything here right so the third problem + + + align:start position:0% +anything here right so the third problem +i identified with the inverse radon + + align:start position:0% +i identified with the inverse radon + + + align:start position:0% +i identified with the inverse radon +transform is that you can't you can't + + align:start position:0% +transform is that you can't you can't + + + align:start position:0% +transform is that you can't you can't +simply evaluate this accumulator in + + align:start position:0% +simply evaluate this accumulator in + + + align:start position:0% +simply evaluate this accumulator in +inverse transform + + align:start position:0% +inverse transform + + + align:start position:0% +inverse transform +right so here's just an example so if + + align:start position:0% +right so here's just an example so if + + + align:start position:0% +right so here's just an example so if +you only take it every 30 degrees you + + align:start position:0% +you only take it every 30 degrees you + + + align:start position:0% +you only take it every 30 degrees you +can see verse 5 versus one degree + + align:start position:0% +can see verse 5 versus one degree + + + align:start position:0% +can see verse 5 versus one degree +there's a there's a huge difference in + + align:start position:0% +there's a there's a huge difference in + + + align:start position:0% +there's a there's a huge difference in +the density of angular sampling but then + + align:start position:0% +the density of angular sampling but then + + + align:start position:0% +the density of angular sampling but then +come back + + align:start position:0% +come back + + + align:start position:0% +come back +we have this problem where we get this + + align:start position:0% +we have this problem where we get this + + + align:start position:0% +we have this problem where we get this +hot spot in the center and so if you + + align:start position:0% +hot spot in the center and so if you + + + align:start position:0% +hot spot in the center and so if you +look at this it sort of goes as the + + align:start position:0% +look at this it sort of goes as the + + + align:start position:0% +look at this it sort of goes as the +inverse of the radial frequency + + align:start position:0% +inverse of the radial frequency + + + align:start position:0% +inverse of the radial frequency +right so as i go up higher in radial + + align:start position:0% +right so as i go up higher in radial + + + align:start position:0% +right so as i go up higher in radial +frequency i don't have this problem as + + align:start position:0% +frequency i don't have this problem as + + + align:start position:0% +frequency i don't have this problem as +much and so the solution it's up here + + align:start position:0% +much and so the solution it's up here + + + align:start position:0% +much and so the solution it's up here +but does anyone want to tell me what the + + align:start position:0% +but does anyone want to tell me what the + + + align:start position:0% +but does anyone want to tell me what the +solution is + + align:start position:0% +solution is + + + align:start position:0% +solution is +to solve the hot spot + + align:start position:0% + + + + align:start position:0% + +multiply by the inverse right so that + + align:start position:0% +multiply by the inverse right so that + + + align:start position:0% +multiply by the inverse right so that +inverse is sort of interesting this so + + align:start position:0% +inverse is sort of interesting this so + + + align:start position:0% +inverse is sort of interesting this so +the direct inverse of this function is + + align:start position:0% +the direct inverse of this function is + + + align:start position:0% +the direct inverse of this function is +simply + + align:start position:0% +simply + + + align:start position:0% +simply +omega itself absolute value of omega so + + align:start position:0% +omega itself absolute value of omega so + + + align:start position:0% +omega itself absolute value of omega so +as a frequency domain filter it's simply + + align:start position:0% +as a frequency domain filter it's simply + + + align:start position:0% +as a frequency domain filter it's simply +saying multiply by a gain which is + + align:start position:0% +saying multiply by a gain which is + + + align:start position:0% +saying multiply by a gain which is +proportional to your radius away from + + align:start position:0% +proportional to your radius away from + + + align:start position:0% +proportional to your radius away from +the center of the image + + align:start position:0% +the center of the image + + + align:start position:0% +the center of the image +right so what kind of filter is this + + align:start position:0% + + + + align:start position:0% + +high pass filter right so the algorithm + + align:start position:0% +high pass filter right so the algorithm + + + align:start position:0% +high pass filter right so the algorithm +is telling us so we're multiplying by + + align:start position:0% +is telling us so we're multiplying by + + + align:start position:0% +is telling us so we're multiplying by +this high pass filter which means what + + align:start position:0% +this high pass filter which means what + + + align:start position:0% +this high pass filter which means what +we're doing in the primary domain is + + align:start position:0% +we're doing in the primary domain is + + + align:start position:0% +we're doing in the primary domain is +we're sharpening does that make sense + + align:start position:0% +we're sharpening does that make sense + + + align:start position:0% +we're sharpening does that make sense +we're convolving with a sharpening + + align:start position:0% +we're convolving with a sharpening + + + align:start position:0% +we're convolving with a sharpening +filter + + align:start position:0% +filter + + + align:start position:0% +filter +and so that adds some other problems is + + align:start position:0% +and so that adds some other problems is + + + align:start position:0% +and so that adds some other problems is +basically this is this filter amplifies + + align:start position:0% +basically this is this filter amplifies + + + align:start position:0% +basically this is this filter amplifies +high frequency noise + + align:start position:0% +high frequency noise + + + align:start position:0% +high frequency noise +right so in general in ct scanning in + + align:start position:0% +right so in general in ct scanning in + + + align:start position:0% +right so in general in ct scanning in +the 80s and 70s basically they examined + + align:start position:0% +the 80s and 70s basically they examined + + + align:start position:0% +the 80s and 70s basically they examined +you're sort of appetizing this filter + + align:start position:0% +you're sort of appetizing this filter + + + align:start position:0% +you're sort of appetizing this filter +having it trail off + + align:start position:0% +having it trail off + + + align:start position:0% +having it trail off +at some frequency so you don't + + align:start position:0% +at some frequency so you don't + + + align:start position:0% +at some frequency so you don't +arbitrarily amplify high frequencies so + + align:start position:0% +arbitrarily amplify high frequencies so + + + align:start position:0% +arbitrarily amplify high frequencies so +again you can sort of just this is again + + align:start position:0% +again you can sort of just this is again + + + align:start position:0% +again you can sort of just this is again +all this is the textbook solution but it + + align:start position:0% +all this is the textbook solution but it + + + align:start position:0% +all this is the textbook solution but it +sort of contains all of the ideas of ct + + align:start position:0% +sort of contains all of the ideas of ct + + + align:start position:0% +sort of contains all of the ideas of ct +and certainly how they apply to light + + align:start position:0% +and certainly how they apply to light + + + align:start position:0% +and certainly how they apply to light +fields all of these ideas are there as + + align:start position:0% +fields all of these ideas are there as + + + align:start position:0% +fields all of these ideas are there as +well in light field + + align:start position:0% +well in light field + + + align:start position:0% +well in light field +refocusing you need to have these + + align:start position:0% +refocusing you need to have these + + + align:start position:0% +refocusing you need to have these +filters to represent prevent aliasing + + align:start position:0% +filters to represent prevent aliasing + + + align:start position:0% +filters to represent prevent aliasing +right it might feel refocusing you have + + align:start position:0% +right it might feel refocusing you have + + + align:start position:0% +right it might feel refocusing you have +a baseline to sample your light field + + align:start position:0% +a baseline to sample your light field + + + align:start position:0% +a baseline to sample your light field +etc so uh for those of you working on + + align:start position:0% +etc so uh for those of you working on + + + align:start position:0% +etc so uh for those of you working on +final projects you should really try to + + align:start position:0% +final projects you should really try to + + + align:start position:0% +final projects you should really try to +think about the connection to tomography + + align:start position:0% +think about the connection to tomography + + + align:start position:0% +think about the connection to tomography +we're going to talk about the + + align:start position:0% +we're going to talk about the + + + align:start position:0% +we're going to talk about the +teeth oh yeah sorry uh yeah i almost + + align:start position:0% +teeth oh yeah sorry uh yeah i almost + + + align:start position:0% +teeth oh yeah sorry uh yeah i almost +missed that so this is another + + align:start position:0% +missed that so this is another + + + align:start position:0% +missed that so this is another +so the whole assumption that we made at + + align:start position:0% +so the whole assumption that we made at + + + align:start position:0% +so the whole assumption that we made at +the very beginning is that we could find + + align:start position:0% +the very beginning is that we could find + + + align:start position:0% +the very beginning is that we could find +some wavelength of light + + align:start position:0% +some wavelength of light + + + align:start position:0% +some wavelength of light +or electromagnetic radiation that + + align:start position:0% +or electromagnetic radiation that + + + align:start position:0% +or electromagnetic radiation that +travels on a ballistic trajectory + + align:start position:0% +travels on a ballistic trajectory + + + align:start position:0% +travels on a ballistic trajectory +through our object right so our object + + align:start position:0% +through our object right so our object + + + align:start position:0% +through our object right so our object +becomes semi-transparent and simply + + align:start position:0% +becomes semi-transparent and simply + + + align:start position:0% +becomes semi-transparent and simply +absorbs but that's not true for the + + align:start position:0% +absorbs but that's not true for the + + + align:start position:0% +absorbs but that's not true for the +human body for the most part it inside + + align:start position:0% +human body for the most part it inside + + + align:start position:0% +human body for the most part it inside +bone skin + + align:start position:0% +bone skin + + + align:start position:0% +bone skin +and and in various cells that's for the + + align:start position:0% +and and in various cells that's for the + + + align:start position:0% +and and in various cells that's for the +most part true that x-rays travel on a + + align:start position:0% +most part true that x-rays travel on a + + + align:start position:0% +most part true that x-rays travel on a +ballistic trajectory there is some + + align:start position:0% +ballistic trajectory there is some + + + align:start position:0% +ballistic trajectory there is some +scattering for bone you need to handle + + align:start position:0% +scattering for bone you need to handle + + + align:start position:0% +scattering for bone you need to handle +but can anyone guess what these are here + + align:start position:0% +but can anyone guess what these are here + + + align:start position:0% +but can anyone guess what these are here +yes + + align:start position:0% +yes + + + align:start position:0% +yes +so the problem with fillings is they're + + align:start position:0% +so the problem with fillings is they're + + + align:start position:0% +so the problem with fillings is they're +metal + + align:start position:0% +metal + + + align:start position:0% +metal +and so they for the most part scatter + + align:start position:0% +and so they for the most part scatter + + + align:start position:0% +and so they for the most part scatter +and absorb x-rays + + align:start position:0% +and absorb x-rays + + + align:start position:0% +and absorb x-rays +and so you'll see we get these artifacts + + align:start position:0% +and so you'll see we get these artifacts + + + align:start position:0% +and so you'll see we get these artifacts +where essentially we have missing data + + align:start position:0% +where essentially we have missing data + + + align:start position:0% +where essentially we have missing data +and so when we reconstruct we get these + + align:start position:0% +and so when we reconstruct we get these + + + align:start position:0% +and so when we reconstruct we get these +halos around the object + + align:start position:0% +halos around the object + + + align:start position:0% +halos around the object +and so yeah i think they're called + + align:start position:0% +and so yeah i think they're called + + + align:start position:0% +and so yeah i think they're called +starbursts + + align:start position:0% + + + + align:start position:0% + +okay so you get these starbursts which + + align:start position:0% +okay so you get these starbursts which + + + align:start position:0% +okay so you get these starbursts which +have to do with your number of samples + + align:start position:0% +have to do with your number of samples + + + align:start position:0% +have to do with your number of samples +you took because you can see the + + align:start position:0% +you took because you can see the + + + align:start position:0% +you took because you can see the +starburst pattern like in the 30 degree + + align:start position:0% +starburst pattern like in the 30 degree + + + align:start position:0% +starburst pattern like in the 30 degree +if you have limited angle you can + + align:start position:0% +if you have limited angle you can + + + align:start position:0% +if you have limited angle you can +actually get starburst patterns you can + + align:start position:0% +actually get starburst patterns you can + + + align:start position:0% +actually get starburst patterns you can +see it also in that one on the left + + align:start position:0% +see it also in that one on the left + + + align:start position:0% +see it also in that one on the left +and so then the question is + + align:start position:0% +and so then the question is + + + align:start position:0% +and so then the question is +how do you handle these occlusion + + align:start position:0% +how do you handle these occlusion + + + align:start position:0% +how do you handle these occlusion +functions and there are some simple and + + align:start position:0% +functions and there are some simple and + + + align:start position:0% +functions and there are some simple and +more complicated methods to handle this + + align:start position:0% +more complicated methods to handle this + + + align:start position:0% +more complicated methods to handle this +but modern ct scanners for the most part + + align:start position:0% +but modern ct scanners for the most part + + + align:start position:0% +but modern ct scanners for the most part +can now scan fillings using + + align:start position:0% +can now scan fillings using + + + align:start position:0% +can now scan fillings using +relatively simple algorithms + + align:start position:0% +relatively simple algorithms + + + align:start position:0% +relatively simple algorithms +and so now + + align:start position:0% +and so now + + + align:start position:0% +and so now +putting all this together we solved the + + align:start position:0% +putting all this together we solved the + + + align:start position:0% +putting all this together we solved the +problem in flatland so now we can build + + align:start position:0% +problem in flatland so now we can build + + + align:start position:0% +problem in flatland so now we can build +a ct scanner to do the volumetric + + align:start position:0% +a ct scanner to do the volumetric + + + align:start position:0% +a ct scanner to do the volumetric +scanning task it's very simple we're + + align:start position:0% +scanning task it's very simple we're + + + align:start position:0% +scanning task it's very simple we're +just going to solve the problem + + align:start position:0% +just going to solve the problem + + + align:start position:0% +just going to solve the problem +repeatedly in two dimensions and so how + + align:start position:0% +repeatedly in two dimensions and so how + + + align:start position:0% +repeatedly in two dimensions and so how +many here have had a ct scan anyone no + + align:start position:0% +many here have had a ct scan anyone no + + + align:start position:0% +many here have had a ct scan anyone no +one + + align:start position:0% +one + + + align:start position:0% +one +right the older ones of us have had cc + + align:start position:0% +right the older ones of us have had cc + + + align:start position:0% +right the older ones of us have had cc +scans i guess + + align:start position:0% +scans i guess + + + align:start position:0% +scans i guess +so uh + + align:start position:0% +so uh + + + align:start position:0% +so uh +so this i think this is great + + align:start position:0% + + + + align:start position:0% + +so if you go to youtube this is a ct + + align:start position:0% +so if you go to youtube this is a ct + + + align:start position:0% +so if you go to youtube this is a ct +scanner opened up so + + align:start position:0% +scanner opened up so + + + align:start position:0% +scanner opened up so +maybe i should stop it and go back to + + align:start position:0% +maybe i should stop it and go back to + + + align:start position:0% +maybe i should stop it and go back to +the beginning just to explain what + + align:start position:0% +the beginning just to explain what + + + align:start position:0% +the beginning just to explain what +you're seeing + + align:start position:0% +you're seeing + + + align:start position:0% +you're seeing +here so + + align:start position:0% + + + + align:start position:0% + +let's see + + align:start position:0% +let's see + + + align:start position:0% +let's see +we'll see + + align:start position:0% +we'll see + + + align:start position:0% +we'll see +yeah the audio is very important so uh + + align:start position:0% +yeah the audio is very important so uh + + + align:start position:0% +yeah the audio is very important so uh +the radiologists at the hospital have to + + align:start position:0% +the radiologists at the hospital have to + + + align:start position:0% +the radiologists at the hospital have to +take apprentice ct scanner periodically + + align:start position:0% +take apprentice ct scanner periodically + + + align:start position:0% +take apprentice ct scanner periodically +and inspect it for damage because it's + + align:start position:0% +and inspect it for damage because it's + + + align:start position:0% +and inspect it for damage because it's +essentially a high quality motor like a + + align:start position:0% +essentially a high quality motor like a + + + align:start position:0% +essentially a high quality motor like a +jet engine so you'll see in a minute why + + align:start position:0% +jet engine so you'll see in a minute why + + + align:start position:0% +jet engine so you'll see in a minute why +why general electric and other + + align:start position:0% +why general electric and other + + + align:start position:0% +why general electric and other +industrial you know jet engine + + align:start position:0% +industrial you know jet engine + + + align:start position:0% +industrial you know jet engine +manufacturers make ct scanners but this + + align:start position:0% +manufacturers make ct scanners but this + + + align:start position:0% +manufacturers make ct scanners but this +this is a ct scanner with the cover + + align:start position:0% +this is a ct scanner with the cover + + + align:start position:0% +this is a ct scanner with the cover +removed and so basically the patient + + align:start position:0% +removed and so basically the patient + + + align:start position:0% +removed and so basically the patient +lays on this gurney and they're slowly + + align:start position:0% +lays on this gurney and they're slowly + + + align:start position:0% +lays on this gurney and they're slowly +translated through this doughnut + + align:start position:0% +translated through this doughnut + + + align:start position:0% +translated through this doughnut +right and so you'll see here this is the + + align:start position:0% +right and so you'll see here this is the + + + align:start position:0% +right and so you'll see here this is the +x it's a little blurry and still but you + + align:start position:0% +x it's a little blurry and still but you + + + align:start position:0% +x it's a little blurry and still but you +can see this is the x-ray source it's a + + align:start position:0% +can see this is the x-ray source it's a + + + align:start position:0% +can see this is the x-ray source it's a +point source this is a fan beam + + align:start position:0% +point source this is a fan beam + + + align:start position:0% +point source this is a fan beam +projection and over here with a bunch of + + align:start position:0% +projection and over here with a bunch of + + + align:start position:0% +projection and over here with a bunch of +fans on top of it are the x-ray + + align:start position:0% +fans on top of it are the x-ray + + + align:start position:0% +fans on top of it are the x-ray +detectors because they generate a lot of + + align:start position:0% +detectors because they generate a lot of + + + align:start position:0% +detectors because they generate a lot of +heat and so basically this thing will + + align:start position:0% +heat and so basically this thing will + + + align:start position:0% +heat and so basically this thing will +rotate around the patient as the patient + + align:start position:0% +rotate around the patient as the patient + + + align:start position:0% +rotate around the patient as the patient +translates slowly so the so in the frame + + align:start position:0% +translates slowly so the so in the frame + + + align:start position:0% +translates slowly so the so in the frame +of the patient the x-ray source will + + align:start position:0% +of the patient the x-ray source will + + + align:start position:0% +of the patient the x-ray source will +move on this helix + + align:start position:0% +move on this helix + + + align:start position:0% +move on this helix +right and at each orientation it will + + align:start position:0% +right and at each orientation it will + + + align:start position:0% +right and at each orientation it will +take a fan beam projection and you can + + align:start position:0% +take a fan beam projection and you can + + + align:start position:0% +take a fan beam projection and you can +re-sample that data + + align:start position:0% +re-sample that data + + + align:start position:0% +re-sample that data +if you have a dense enough helix to be + + align:start position:0% +if you have a dense enough helix to be + + + align:start position:0% +if you have a dense enough helix to be +just a set of pair of parallel beam + + align:start position:0% +just a set of pair of parallel beam + + + align:start position:0% +just a set of pair of parallel beam +projections which you then each of those + + align:start position:0% +projections which you then each of those + + + align:start position:0% +projections which you then each of those +independently apply the inverse radon + + align:start position:0% +independently apply the inverse radon + + + align:start position:0% +independently apply the inverse radon +transform that's not exactly what they + + align:start position:0% +transform that's not exactly what they + + + align:start position:0% +transform that's not exactly what they +do but if you were to implement this in + + align:start position:0% +do but if you were to implement this in + + + align:start position:0% +do but if you were to implement this in +matlab that would be basically good + + align:start position:0% +matlab that would be basically good + + + align:start position:0% +matlab that would be basically good +enough and so then you'll get a series + + align:start position:0% +enough and so then you'll get a series + + + align:start position:0% +enough and so then you'll get a series +of cross-sectional images + + align:start position:0% +of cross-sectional images + + + align:start position:0% +of cross-sectional images +then you can simply do segmentation and + + align:start position:0% +then you can simply do segmentation and + + + align:start position:0% +then you can simply do segmentation and +thresholding for instance high density + + align:start position:0% +thresholding for instance high density + + + align:start position:0% +thresholding for instance high density +regions correspond to bone + + align:start position:0% +regions correspond to bone + + + align:start position:0% +regions correspond to bone +other properties correspond to blood + + align:start position:0% +other properties correspond to blood + + + align:start position:0% +other properties correspond to blood +vessel networks so that's the basics of + + align:start position:0% +vessel networks so that's the basics of + + + align:start position:0% +vessel networks so that's the basics of +the ct scanner but i think it's so the + + align:start position:0% +the ct scanner but i think it's so the + + + align:start position:0% +the ct scanner but i think it's so the +see the the radiologists and the techs + + align:start position:0% +see the the radiologists and the techs + + + align:start position:0% +see the the radiologists and the techs +often have to take this apart to inspect + + align:start position:0% +often have to take this apart to inspect + + + align:start position:0% +often have to take this apart to inspect +it and so you'll notice uh this thing is + + align:start position:0% +it and so you'll notice uh this thing is + + + align:start position:0% +it and so you'll notice uh this thing is +quite scary with the cover off + + align:start position:0% +quite scary with the cover off + + + align:start position:0% +quite scary with the cover off +and you can listen to what the + + align:start position:0% +and you can listen to what the + + + align:start position:0% +and you can listen to what the +radiologists are saying as they're + + align:start position:0% +radiologists are saying as they're + + + align:start position:0% +radiologists are saying as they're +inspecting this + + align:start position:0% +inspecting this + + + align:start position:0% +inspecting this +so again it spins up + + align:start position:0% + + + + align:start position:0% + +so if you ever get a ct scan that's + + align:start position:0% +so if you ever get a ct scan that's + + + align:start position:0% +so if you ever get a ct scan that's +what's happening but of course the + + align:start position:0% +what's happening but of course the + + + align:start position:0% +what's happening but of course the +safest place to be is inside the donut + + align:start position:0% +safest place to be is inside the donut + + + align:start position:0% +safest place to be is inside the donut +outside is the problem inside the room + + align:start position:0% +outside is the problem inside the room + + + align:start position:0% +outside is the problem inside the room +outside the room is a better place but + + align:start position:0% +outside the room is a better place but + + + align:start position:0% +outside the room is a better place but +you can see that there's a lot of + + align:start position:0% +you can see that there's a lot of + + + align:start position:0% +you can see that there's a lot of +problems i have to solve mechanical so + + align:start position:0% +problems i have to solve mechanical so + + + align:start position:0% +problems i have to solve mechanical so +they have sort of like a hard drive they + + align:start position:0% +they have sort of like a hard drive they + + + align:start position:0% +they have sort of like a hard drive they +have optical encoders here to track + + align:start position:0% +have optical encoders here to track + + + align:start position:0% +have optical encoders here to track +their rotational velocity and then they + + align:start position:0% +their rotational velocity and then they + + + align:start position:0% +their rotational velocity and then they +have what's known as slip rings because + + align:start position:0% +have what's known as slip rings because + + + align:start position:0% +have what's known as slip rings because +basically one of the evolutions believe + + align:start position:0% +basically one of the evolutions believe + + + align:start position:0% +basically one of the evolutions believe +it or not was just getting the data off + + align:start position:0% +it or not was just getting the data off + + + align:start position:0% +it or not was just getting the data off +these detectors and so they actually the + + align:start position:0% +these detectors and so they actually the + + + align:start position:0% +these detectors and so they actually the +bearings are used as a circuit to just + + align:start position:0% +bearings are used as a circuit to just + + + align:start position:0% +bearings are used as a circuit to just +transmit data across the bearings and + + align:start position:0% +transmit data across the bearings and + + + align:start position:0% +transmit data across the bearings and +believe it or not that was a big insight + + align:start position:0% +believe it or not that was a big insight + + + align:start position:0% +believe it or not that was a big insight +and a huge patent and before they they + + align:start position:0% +and a huge patent and before they they + + + align:start position:0% +and a huge patent and before they they +actually could only rotate once and the + + align:start position:0% +actually could only rotate once and the + + + align:start position:0% +actually could only rotate once and the +wires would get tangled up + + align:start position:0% +wires would get tangled up + + + align:start position:0% +wires would get tangled up +so having the slip ring bearing transfer + + align:start position:0% +so having the slip ring bearing transfer + + + align:start position:0% +so having the slip ring bearing transfer +mechanism was the big evolution that + + align:start position:0% +mechanism was the big evolution that + + + align:start position:0% +mechanism was the big evolution that +made million dollar ct scanners possible + + align:start position:0% +made million dollar ct scanners possible + + + align:start position:0% +made million dollar ct scanners possible +and so most of these cost a million + + align:start position:0% +and so most of these cost a million + + + align:start position:0% +and so most of these cost a million +dollars and as you're watching this + + align:start position:0% +dollars and as you're watching this + + + align:start position:0% +dollars and as you're watching this +uh + + align:start position:0% +uh + + + align:start position:0% +uh +just point out again that the story i'm + + align:start position:0% +just point out again that the story i'm + + + align:start position:0% +just point out again that the story i'm +trying to give you is that this very + + align:start position:0% +trying to give you is that this very + + + align:start position:0% +trying to give you is that this very +basic idea of tomography and inverse + + align:start position:0% +basic idea of tomography and inverse + + + align:start position:0% +basic idea of tomography and inverse +radon transform gives you almost all the + + align:start position:0% +radon transform gives you almost all the + + + align:start position:0% +radon transform gives you almost all the +medical scanning devices that we're so + + align:start position:0% +medical scanning devices that we're so + + + align:start position:0% +medical scanning devices that we're so +proud of in the 20th century you know of + + align:start position:0% +proud of in the 20th century you know of + + + align:start position:0% +proud of in the 20th century you know of +course x-rays give you ct if you move to + + align:start position:0% +course x-rays give you ct if you move to + + + align:start position:0% +course x-rays give you ct if you move to +gamma rays you get spect + + align:start position:0% +gamma rays you get spect + + + align:start position:0% +gamma rays you get spect +if you look at positron emission + + align:start position:0% +if you look at positron emission + + + align:start position:0% +if you look at positron emission +tomography it's just a different + + align:start position:0% +tomography it's just a different + + + align:start position:0% +tomography it's just a different +wavelength of light and again if we move + + align:start position:0% +wavelength of light and again if we move + + + align:start position:0% +wavelength of light and again if we move +to ultrasound so we become acoustic + + align:start position:0% +to ultrasound so we become acoustic + + + align:start position:0% +to ultrasound so we become acoustic +that's really when you get into + + align:start position:0% +that's really when you get into + + + align:start position:0% +that's really when you get into +ultrasonography which is a reflection + + align:start position:0% +ultrasonography which is a reflection + + + align:start position:0% +ultrasonography which is a reflection +mode version of this you can reformulate + + align:start position:0% +mode version of this you can reformulate + + + align:start position:0% +mode version of this you can reformulate +all of these equations instead of the + + align:start position:0% +all of these equations instead of the + + + align:start position:0% +all of these equations instead of the +transmission through reflection mode and + + align:start position:0% +transmission through reflection mode and + + + align:start position:0% +transmission through reflection mode and +that's in slightly impact but i actually + + align:start position:0% +that's in slightly impact but i actually + + + align:start position:0% +that's in slightly impact but i actually +won't go into it so the takeaway message + + align:start position:0% +won't go into it so the takeaway message + + + align:start position:0% +won't go into it so the takeaway message +is that choose your wavelength apply + + align:start position:0% +is that choose your wavelength apply + + + align:start position:0% +is that choose your wavelength apply +inverse radon transform and you too can + + align:start position:0% +inverse radon transform and you too can + + + align:start position:0% +inverse radon transform and you too can +can image non-invasively so just as a + + align:start position:0% +can image non-invasively so just as a + + + align:start position:0% +can image non-invasively so just as a +thought experiment can you see a + + align:start position:0% +thought experiment can you see a + + + align:start position:0% +thought experiment can you see a +relationship between this crazy jet + + align:start position:0% +relationship between this crazy jet + + + align:start position:0% +relationship between this crazy jet +engine + + align:start position:0% +engine + + + align:start position:0% +engine +and delightful camera + + align:start position:0% + + + + align:start position:0% + +we'll come back to it but just keep that + + align:start position:0% +we'll come back to it but just keep that + + + align:start position:0% +we'll come back to it but just keep that +in the back of your mind + + align:start position:0% +in the back of your mind + + + align:start position:0% +in the back of your mind +just take the four transformers so + + align:start position:0% +just take the four transformers so + + + align:start position:0% +just take the four transformers so +that's it that's all there is that is + + align:start position:0% +that's it that's all there is that is + + + align:start position:0% +that's it that's all there is that is +this is it and imagine now the + + align:start position:0% +this is it and imagine now the + + + align:start position:0% +this is it and imagine now the +light-filled camera is compact and + + align:start position:0% +light-filled camera is compact and + + + align:start position:0% +light-filled camera is compact and +something you can carry in your pocket + + align:start position:0% +something you can carry in your pocket + + + align:start position:0% +something you can carry in your pocket +question is + + align:start position:0% +question is + + + align:start position:0% +question is +can you carry the cat scan + + align:start position:0% +can you carry the cat scan + + + align:start position:0% +can you carry the cat scan +machine + + align:start position:0% +machine + + + align:start position:0% +machine +in the future + + align:start position:0% +in the future + + + align:start position:0% +in the future +in your pocket + + align:start position:0% +in your pocket + + + align:start position:0% +in your pocket +right so we'll come back to our meshes + + align:start position:0% +right so we'll come back to our meshes + + + align:start position:0% +right so we'll come back to our meshes +puzzle at the end and see if anyone + + align:start position:0% +puzzle at the end and see if anyone + + + align:start position:0% +puzzle at the end and see if anyone +solved it + + align:start position:0% +solved it + + + align:start position:0% +solved it +so before i go on there's a slide later + + align:start position:0% +so before i go on there's a slide later + + + align:start position:0% +so before i go on there's a slide later +that you explain score i only explained + + align:start position:0% +that you explain score i only explained + + + align:start position:0% +that you explain score i only explained +the frequency domain version of this and + + align:start position:0% +the frequency domain version of this and + + + align:start position:0% +the frequency domain version of this and +so for various reasons if you don't have + + align:start position:0% +so for various reasons if you don't have + + + align:start position:0% +so for various reasons if you don't have +a fast fft + + align:start position:0% +a fast fft + + + align:start position:0% +a fast fft +which you do of course now + + align:start position:0% +which you do of course now + + + align:start position:0% +which you do of course now +there's a purely spatial domain + + align:start position:0% +there's a purely spatial domain + + + align:start position:0% +there's a purely spatial domain +algorithm so remember our algorithm was + + align:start position:0% +algorithm so remember our algorithm was + + + align:start position:0% +algorithm so remember our algorithm was +we take all of these projections take + + align:start position:0% +we take all of these projections take + + + align:start position:0% +we take all of these projections take +their one equation transforms and + + align:start position:0% +their one equation transforms and + + + align:start position:0% +their one equation transforms and +populate + + align:start position:0% +populate + + + align:start position:0% +populate +our four transforming inverse but you + + align:start position:0% +our four transforming inverse but you + + + align:start position:0% +our four transforming inverse but you +can actually do this without ever taking + + align:start position:0% +can actually do this without ever taking + + + align:start position:0% +can actually do this without ever taking +a fourier transform + + align:start position:0% +a fourier transform + + + align:start position:0% +a fourier transform +does anyone see how you do that + + align:start position:0% +does anyone see how you do that + + + align:start position:0% +does anyone see how you do that +there's a purely spatial domain + + align:start position:0% +there's a purely spatial domain + + + align:start position:0% +there's a purely spatial domain +algorithm you get the set of projections + + align:start position:0% +algorithm you get the set of projections + + + align:start position:0% +algorithm you get the set of projections +and you directly reconstruct the density + + align:start position:0% +and you directly reconstruct the density + + + align:start position:0% +and you directly reconstruct the density +function + + align:start position:0% +function + + + align:start position:0% +function +you just accumulate the + + align:start position:0% +you just accumulate the + + + align:start position:0% +you just accumulate the +projections + + align:start position:0% +projections + + + align:start position:0% +projections +how so + + align:start position:0% +how so + + + align:start position:0% +how so +let's go back to our image so you can + + align:start position:0% +let's go back to our image so you can + + + align:start position:0% +let's go back to our image so you can +tell i overused the socratic method but + + align:start position:0% +tell i overused the socratic method but + + + align:start position:0% +tell i overused the socratic method but +i like you guys to figure things out + + align:start position:0% +i like you guys to figure things out + + + align:start position:0% +i like you guys to figure things out +because i know the answer + + align:start position:0% +because i know the answer + + + align:start position:0% +because i know the answer +so so you give this data go for it + + align:start position:0% +so so you give this data go for it + + + align:start position:0% +so so you give this data go for it +transfers now how you can get back to + + align:start position:0% +transfers now how you can get back to + + + align:start position:0% +transfers now how you can get back to +this + + align:start position:0% +this + + + align:start position:0% +this +without fourier transform this time + + align:start position:0% +without fourier transform this time + + + align:start position:0% +without fourier transform this time +right this is problem b on the home on + + align:start position:0% +right this is problem b on the home on + + + align:start position:0% +right this is problem b on the home on +the on the on the final part a with the + + align:start position:0% +the on the on the final part a with the + + + align:start position:0% +the on the on the final part a with the +support train so now you're not allowed + + align:start position:0% +support train so now you're not allowed + + + align:start position:0% +support train so now you're not allowed +on the mixture + + align:start position:0% +on the mixture + + + align:start position:0% +on the mixture +okay which is next week there will be a + + align:start position:0% +okay which is next week there will be a + + + align:start position:0% +okay which is next week there will be a +question on tomography so yeah okay okay + + align:start position:0% +question on tomography so yeah okay okay + + + align:start position:0% +question on tomography so yeah okay okay +i'm just kind of like shooting the darts + + align:start position:0% +i'm just kind of like shooting the darts + + + align:start position:0% +i'm just kind of like shooting the darts +that's great but uh i guess they take + + align:start position:0% +that's great but uh i guess they take + + + align:start position:0% +that's great but uh i guess they take +the first round and since that yeah oh + + align:start position:0% +the first round and since that yeah oh + + + align:start position:0% +the first round and since that yeah oh +wait actually rotation is this way so + + align:start position:0% +wait actually rotation is this way so + + + align:start position:0% +wait actually rotation is this way so +take the first row like this first let's + + align:start position:0% +take the first row like this first let's + + + align:start position:0% +take the first row like this first let's +follow + + align:start position:0% +follow + + + align:start position:0% +follow +rower kong what do you want first column + + align:start position:0% +rower kong what do you want first column + + + align:start position:0% +rower kong what do you want first column +is the first photo first column is first + + align:start position:0% +is the first photo first column is first + + + align:start position:0% +is the first photo first column is first +projection oh + + align:start position:0% +projection oh + + + align:start position:0% +projection oh +okay first column okay i got first + + align:start position:0% +okay first column okay i got first + + + align:start position:0% +okay first column okay i got first +column and then i'll basically create + + align:start position:0% +column and then i'll basically create + + + align:start position:0% +column and then i'll basically create +rays they're + + align:start position:0% +rays they're + + + align:start position:0% +rays they're +uh representative of those individual + + align:start position:0% +uh representative of those individual + + + align:start position:0% +uh representative of those individual +measured densities and just + + align:start position:0% +measured densities and just + + + align:start position:0% +measured densities and just +uh shoot them back out okay + + align:start position:0% +uh shoot them back out okay + + + align:start position:0% +uh shoot them back out okay +that's the next column and then i guess + + align:start position:0% +that's the next column and then i guess + + + align:start position:0% +that's the next column and then i guess +it's a different slightly different + + align:start position:0% +it's a different slightly different + + + align:start position:0% +it's a different slightly different +angle so i'll do just shoot them back so + + align:start position:0% +angle so i'll do just shoot them back so + + + align:start position:0% +angle so i'll do just shoot them back so +so you're okay so just you're going to + + align:start position:0% +so you're okay so just you're going to + + + align:start position:0% +so you're okay so just you're going to +start with an accumulator again that's + + align:start position:0% +start with an accumulator again that's + + + align:start position:0% +start with an accumulator again that's +all zeros that's your initial estimate + + align:start position:0% +all zeros that's your initial estimate + + + align:start position:0% +all zeros that's your initial estimate +i'm going to take one line of that and + + align:start position:0% +i'm going to take one line of that and + + + align:start position:0% +i'm going to take one line of that and +basically + + align:start position:0% +basically + + + align:start position:0% +basically +uh just fill the entire thing + + align:start position:0% +uh just fill the entire thing + + + align:start position:0% +uh just fill the entire thing +with + + align:start position:0% +with + + + align:start position:0% +with +that so we're gonna take that value and + + align:start position:0% +that so we're gonna take that value and + + + align:start position:0% +that so we're gonna take that value and +just replicate it basically okay and + + align:start position:0% +just replicate it basically okay and + + + align:start position:0% +just replicate it basically okay and +then i'll do that for the second one but + + align:start position:0% +then i'll do that for the second one but + + + align:start position:0% +then i'll do that for the second one but +at an angle okay and i'll normalize it + + align:start position:0% +at an angle okay and i'll normalize it + + + align:start position:0% +at an angle okay and i'll normalize it +yep hopefully i'll get something that + + align:start position:0% +yep hopefully i'll get something that + + + align:start position:0% +yep hopefully i'll get something that +looks like a skull okay that is the + + align:start position:0% +looks like a skull okay that is the + + + align:start position:0% +looks like a skull okay that is the +algorithm it's called filtered back + + align:start position:0% +algorithm it's called filtered back + + + align:start position:0% +algorithm it's called filtered back +projection can you prove why it's + + align:start position:0% +projection can you prove why it's + + + align:start position:0% +projection can you prove why it's +correct + + align:start position:0% +correct + + + align:start position:0% +correct +so so does it does that does everyone + + align:start position:0% +so so does it does that does everyone + + + align:start position:0% +so so does it does that does everyone +understand why that would work even + + align:start position:0% +understand why that would work even + + + align:start position:0% +understand why that would work even +intuitively like imagine + + align:start position:0% +intuitively like imagine + + + align:start position:0% +intuitively like imagine +let's go back to intuition works pretty + + align:start position:0% +let's go back to intuition works pretty + + + align:start position:0% +let's go back to intuition works pretty +well here imagine i just had a big + + align:start position:0% +well here imagine i just had a big + + + align:start position:0% +well here imagine i just had a big +circle here it's it's absorbing 50 it's + + align:start position:0% +circle here it's it's absorbing 50 it's + + + align:start position:0% +circle here it's it's absorbing 50 it's +just a circle right so what about what + + align:start position:0% +just a circle right so what about what + + + align:start position:0% +just a circle right so what about what +i'll see here will just be a big + + align:start position:0% +i'll see here will just be a big + + + align:start position:0% +i'll see here will just be a big +rectangle right + + align:start position:0% +rectangle right + + + align:start position:0% +rectangle right +right i'll just have at some value + + align:start position:0% +right i'll just have at some value + + + align:start position:0% +right i'll just have at some value +it'll be one everywhere in 50 everywhere + + align:start position:0% +it'll be one everywhere in 50 everywhere + + + align:start position:0% +it'll be one everywhere in 50 everywhere +inside and 0 outside right + + align:start position:0% +inside and 0 outside right + + + align:start position:0% +inside and 0 outside right +so if i use kevin's algorithm + + align:start position:0% +so if i use kevin's algorithm + + + align:start position:0% +so if i use kevin's algorithm +first my accumulator will be all + + align:start position:0% +first my accumulator will be all + + + align:start position:0% +first my accumulator will be all +all everything in here will be 50 then + + align:start position:0% +all everything in here will be 50 then + + + align:start position:0% +all everything in here will be 50 then +i'll turn and the center will start + + align:start position:0% +i'll turn and the center will start + + + align:start position:0% +i'll turn and the center will start +getting higher + + align:start position:0% +getting higher + + + align:start position:0% +getting higher +right so i'll get that starburst pattern + + align:start position:0% +right so i'll get that starburst pattern + + + align:start position:0% +right so i'll get that starburst pattern +we saw earlier so intuitively it works + + align:start position:0% +we saw earlier so intuitively it works + + + align:start position:0% +we saw earlier so intuitively it works +but mathematically why does it work and + + align:start position:0% +but mathematically why does it work and + + + align:start position:0% +but mathematically why does it work and +i think again now you can use the foil + + align:start position:0% +i think again now you can use the foil + + + align:start position:0% +i think again now you can use the foil +transform it's easy to see + + align:start position:0% +transform it's easy to see + + + align:start position:0% +transform it's easy to see +for those of you familiar with the foil + + align:start position:0% +for those of you familiar with the foil + + + align:start position:0% +for those of you familiar with the foil +transform it's pretty direct let's go + + align:start position:0% +transform it's pretty direct let's go + + + align:start position:0% +transform it's pretty direct let's go +back to uh + + align:start position:0% +back to uh + + + align:start position:0% +back to uh +okay so anytime you have a foia domain + + align:start position:0% +okay so anytime you have a foia domain + + + align:start position:0% +okay so anytime you have a foia domain +problem you always use the same tricks + + align:start position:0% +problem you always use the same tricks + + + align:start position:0% +problem you always use the same tricks +take slices or or use four transform + + align:start position:0% +take slices or or use four transform + + + align:start position:0% +take slices or or use four transform +pairs right and so + + align:start position:0% +pairs right and so + + + align:start position:0% +pairs right and so +so we know that the slice here + + align:start position:0% +so we know that the slice here + + + align:start position:0% +so we know that the slice here +is equivalent to the projection right + + align:start position:0% +is equivalent to the projection right + + + align:start position:0% +is equivalent to the projection right +so if i had some slice some function + + align:start position:0% +so if i had some slice some function + + + align:start position:0% +so if i had some slice some function +again the slice being this value + + align:start position:0% +again the slice being this value + + + align:start position:0% +again the slice being this value +and i'd take its inverse 2d transform of + + align:start position:0% +and i'd take its inverse 2d transform of + + + align:start position:0% +and i'd take its inverse 2d transform of +just a slice what would i get + + align:start position:0% + + + + align:start position:0% + +the bingo + + align:start position:0% +the bingo + + + align:start position:0% +the bingo +yeah so it's not easy to see but + + align:start position:0% +yeah so it's not easy to see but + + + align:start position:0% +yeah so it's not easy to see but +so give me some yeah so + + align:start position:0% +so give me some yeah so + + + align:start position:0% +so give me some yeah so +so if i just start and i have my + + align:start position:0% +so if i just start and i have my + + + align:start position:0% +so if i just start and i have my +accumulator + + align:start position:0% +accumulator + + + align:start position:0% +accumulator +can everyone hope you can see that i + + align:start position:0% +can everyone hope you can see that i + + + align:start position:0% +can everyone hope you can see that i +have kx i have ky + + align:start position:0% +have kx i have ky + + + align:start position:0% +have kx i have ky +and i have some slice we'll say along x + + align:start position:0% +and i have some slice we'll say along x + + + align:start position:0% +and i have some slice we'll say along x +there's a switch right next to it on the + + align:start position:0% +there's a switch right next to it on the + + + align:start position:0% +there's a switch right next to it on the +right side + + align:start position:0% +right side + + + align:start position:0% +right side +right + + align:start position:0% +right + + + align:start position:0% +right +and this function along if i was just + + align:start position:0% +and this function along if i was just + + + align:start position:0% +and this function along if i was just +apply it i'd have kx + + align:start position:0% +apply it i'd have kx + + + align:start position:0% +apply it i'd have kx +versus + + align:start position:0% +versus + + + align:start position:0% +versus +what we call s of + + align:start position:0% +what we call s of + + + align:start position:0% +what we call s of +kx well we'll say it's a continuous + + align:start position:0% +kx well we'll say it's a continuous + + + align:start position:0% +kx well we'll say it's a continuous +function right so i'd have some function + + align:start position:0% +function right so i'd have some function + + + align:start position:0% +function right so i'd have some function +here + + align:start position:0% +here + + + align:start position:0% +here +right + + align:start position:0% +right + + + align:start position:0% +right +and now what i'm asking is if i take + + align:start position:0% +and now what i'm asking is if i take + + + align:start position:0% +and now what i'm asking is if i take +the inverse + + align:start position:0% +the inverse + + + align:start position:0% +the inverse +y transform + + align:start position:0% +y transform + + + align:start position:0% +y transform +what does this function look like + + align:start position:0% +what does this function look like + + + align:start position:0% +what does this function look like +in the primary domain which is x + + align:start position:0% +in the primary domain which is x + + + align:start position:0% +in the primary domain which is x +and y + + align:start position:0% +and y + + + align:start position:0% +and y +it's constantly one of those little + + align:start position:0% +it's constantly one of those little + + + align:start position:0% +it's constantly one of those little +dimensions of these right because this + + align:start position:0% +dimensions of these right because this + + + align:start position:0% +dimensions of these right because this +guy you can write as some function + + align:start position:0% +guy you can write as some function + + + align:start position:0% +guy you can write as some function +f of kx times a delta function of what + + align:start position:0% +f of kx times a delta function of what + + + align:start position:0% +f of kx times a delta function of what +y right + + align:start position:0% +y right + + + align:start position:0% +y right +and we know that the fourier transform + + align:start position:0% +and we know that the fourier transform + + + align:start position:0% +and we know that the fourier transform +pair of a delta function + + align:start position:0% +pair of a delta function + + + align:start position:0% +pair of a delta function +is this + + align:start position:0% +is this + + + align:start position:0% +is this +is all constant absolutely great + + align:start position:0% +is all constant absolutely great + + + align:start position:0% +is all constant absolutely great +so we get the 1d4 transform + + align:start position:0% +so we get the 1d4 transform + + + align:start position:0% +so we get the 1d4 transform +is this thing and the values are simply + + align:start position:0% +is this thing and the values are simply + + + align:start position:0% +is this thing and the values are simply +the inverse + + align:start position:0% +the inverse + + + align:start position:0% +the inverse +for a transform of the 1d function here + + align:start position:0% +for a transform of the 1d function here + + + align:start position:0% +for a transform of the 1d function here +right so we get you know some different + + align:start position:0% +right so we get you know some different + + + align:start position:0% +right so we get you know some different +values here right + + align:start position:0% +values here right + + + align:start position:0% +values here right +right in the middle and not surprisingly + + align:start position:0% +right in the middle and not surprisingly + + + align:start position:0% +right in the middle and not surprisingly +right so this gets why kevin said + + align:start position:0% +right so this gets why kevin said + + + align:start position:0% +right so this gets why kevin said +he may have already known the algorithm + + align:start position:0% +he may have already known the algorithm + + + align:start position:0% +he may have already known the algorithm +but this is mathematically why we smear + + align:start position:0% +but this is mathematically why we smear + + + align:start position:0% +but this is mathematically why we smear +and now if we rotate + + align:start position:0% +and now if we rotate + + + align:start position:0% +and now if we rotate +we have this one + + align:start position:0% +we have this one + + + align:start position:0% +we have this one +which now comes in as a new smear along + + align:start position:0% +which now comes in as a new smear along + + + align:start position:0% +which now comes in as a new smear along +a new angle + + align:start position:0% +a new angle + + + align:start position:0% +a new angle +i do it the wrong way probably but + + align:start position:0% +i do it the wrong way probably but + + + align:start position:0% +i do it the wrong way probably but +right + + align:start position:0% +right + + + align:start position:0% +right +and so it's linearity you can write the + + align:start position:0% +and so it's linearity you can write the + + + align:start position:0% +and so it's linearity you can write the +total fourier transform + + align:start position:0% +total fourier transform + + + align:start position:0% +total fourier transform +f + + align:start position:0% +f + + + align:start position:0% +f +of kx ky + + align:start position:0% +of kx ky + + + align:start position:0% +of kx ky +is equal to sum + + align:start position:0% +is equal to sum + + + align:start position:0% +is equal to sum +over all of your angles of this function + + align:start position:0% +over all of your angles of this function + + + align:start position:0% +over all of your angles of this function +f of which we'll just call it the angle + + align:start position:0% +f of which we'll just call it the angle + + + align:start position:0% +f of which we'll just call it the angle +of delta of which is another function of + + align:start position:0% +of delta of which is another function of + + + align:start position:0% +of delta of which is another function of +the angle right + + align:start position:0% +the angle right + + + align:start position:0% +the angle right +and then by linearity of the fourier + + align:start position:0% +and then by linearity of the fourier + + + align:start position:0% +and then by linearity of the fourier +transform + + align:start position:0% +transform + + + align:start position:0% +transform +we come over here we get a sum over + + align:start position:0% +we come over here we get a sum over + + + align:start position:0% +we come over here we get a sum over +angles of the inverse + + align:start position:0% +angles of the inverse + + + align:start position:0% +angles of the inverse +for a transform of that thing right + + align:start position:0% +for a transform of that thing right + + + align:start position:0% +for a transform of that thing right +linearity of fourier transform so that + + align:start position:0% +linearity of fourier transform so that + + + align:start position:0% +linearity of fourier transform so that +gives you + + align:start position:0% +gives you + + + align:start position:0% +gives you +does that roughly make sense to everyone + + align:start position:0% +does that roughly make sense to everyone + + + align:start position:0% +does that roughly make sense to everyone +so just by applying properties you + + align:start position:0% +so just by applying properties you + + + align:start position:0% +so just by applying properties you +already know the fourier transform + + align:start position:0% +already know the fourier transform + + + align:start position:0% +already know the fourier transform +you can argue why it's correct using + + align:start position:0% +you can argue why it's correct using + + + align:start position:0% +you can argue why it's correct using +using the foid projection slice theorem + + align:start position:0% +using the foid projection slice theorem + + + align:start position:0% +using the foid projection slice theorem +but the end result is you don't need to + + align:start position:0% +but the end result is you don't need to + + + align:start position:0% +but the end result is you don't need to +take any fourier transforms you still + + align:start position:0% +take any fourier transforms you still + + + align:start position:0% +take any fourier transforms you still +need to have that sharpening filter + + align:start position:0% +need to have that sharpening filter + + + align:start position:0% +need to have that sharpening filter +though because you can see that you're + + align:start position:0% +though because you can see that you're + + + align:start position:0% +though because you can see that you're +going to build up too much weight in the + + align:start position:0% +going to build up too much weight in the + + + align:start position:0% +going to build up too much weight in the +center + + align:start position:0% +center + + + align:start position:0% +center +right + + align:start position:0% +right + + + align:start position:0% +right +but other than that pre-filtering step + + align:start position:0% +but other than that pre-filtering step + + + align:start position:0% +but other than that pre-filtering step +that sharpening step filtered back + + align:start position:0% +that sharpening step filtered back + + + align:start position:0% +that sharpening step filtered back +projection will solve the problem right + + align:start position:0% +projection will solve the problem right + + + align:start position:0% +projection will solve the problem right +so that's + + align:start position:0% +so that's + + + align:start position:0% +so that's +this algorithm i just described rather + + align:start position:0% +this algorithm i just described rather + + + align:start position:0% +this algorithm i just described rather +than using the inverse 2e40 transform + + align:start position:0% +than using the inverse 2e40 transform + + + align:start position:0% +than using the inverse 2e40 transform +it's called filtered back projection + + align:start position:0% +it's called filtered back projection + + + align:start position:0% +it's called filtered back projection +because the first step is you high pass + + align:start position:0% +because the first step is you high pass + + + align:start position:0% +because the first step is you high pass +filter all the projections the second + + align:start position:0% +filter all the projections the second + + + align:start position:0% +filter all the projections the second +step is you back project them you smear + + align:start position:0% +step is you back project them you smear + + + align:start position:0% +step is you back project them you smear +them through as kevin described + + align:start position:0% +them through as kevin described + + + align:start position:0% +them through as kevin described +so there's two ways to solve the inverse + + align:start position:0% +so there's two ways to solve the inverse + + + align:start position:0% +so there's two ways to solve the inverse +radon transform you can take the 2d4 + + align:start position:0% +radon transform you can take the 2d4 + + + align:start position:0% +radon transform you can take the 2d4 +transform or you can use the filter back + + align:start position:0% +transform or you can use the filter back + + + align:start position:0% +transform or you can use the filter back +projection + + align:start position:0% +projection + + + align:start position:0% +projection +okay so now we'll move on to so some of + + align:start position:0% +okay so now we'll move on to so some of + + + align:start position:0% +okay so now we'll move on to so some of +my own work i'm just going to plug so + + align:start position:0% +my own work i'm just going to plug so + + + align:start position:0% +my own work i'm just going to plug so +the idea of really marco boyhead and + + align:start position:0% +the idea of really marco boyhead and + + + align:start position:0% +the idea of really marco boyhead and +presenting this at siggraph is to take + + align:start position:0% +presenting this at siggraph is to take + + + align:start position:0% +presenting this at siggraph is to take +inspiration from medical and scientific + + align:start position:0% +inspiration from medical and scientific + + + align:start position:0% +inspiration from medical and scientific +imaging so we can make better canvas + + align:start position:0% +imaging so we can make better canvas + + + align:start position:0% +imaging so we can make better canvas +right we're competition photographer + + align:start position:0% +right we're competition photographer + + + align:start position:0% +right we're competition photographer +optics people how can we improve this + + align:start position:0% +optics people how can we improve this + + + align:start position:0% +optics people how can we improve this +idea and so + + align:start position:0% +idea and so + + + align:start position:0% +idea and so +one of the limitations ramesh identified + + align:start position:0% +one of the limitations ramesh identified + + + align:start position:0% +one of the limitations ramesh identified +with computer tomography why we can't + + align:start position:0% +with computer tomography why we can't + + + align:start position:0% +with computer tomography why we can't +put it in our pocket is that we have a + + align:start position:0% +put it in our pocket is that we have a + + + align:start position:0% +put it in our pocket is that we have a +lot of moving parts we have these x-ray + + align:start position:0% +lot of moving parts we have these x-ray + + + align:start position:0% +lot of moving parts we have these x-ray +sources moving around the object right + + align:start position:0% +sources moving around the object right + + + align:start position:0% +sources moving around the object right +so the question is how can we remove the + + align:start position:0% +so the question is how can we remove the + + + align:start position:0% +so the question is how can we remove the +moving x-ray sources and so just as a + + align:start position:0% +moving x-ray sources and so just as a + + + align:start position:0% +moving x-ray sources and so just as a +thought experiment i'll quickly explain + + align:start position:0% +thought experiment i'll quickly explain + + + align:start position:0% +thought experiment i'll quickly explain +what we did + + align:start position:0% +what we did + + + align:start position:0% +what we did +basically this is another version of ct + + align:start position:0% +basically this is another version of ct + + + align:start position:0% +basically this is another version of ct +you often find is where instead of + + align:start position:0% +you often find is where instead of + + + align:start position:0% +you often find is where instead of +having + + align:start position:0% +having + + + align:start position:0% +having +a rotating point source we simply have a + + align:start position:0% +a rotating point source we simply have a + + + align:start position:0% +a rotating point source we simply have a +linear array of sources + + align:start position:0% +linear array of sources + + + align:start position:0% +linear array of sources +right and then we have a film plane say + + align:start position:0% +right and then we have a film plane say + + + align:start position:0% +right and then we have a film plane say +our x-ray detector on one side of an + + align:start position:0% +our x-ray detector on one side of an + + + align:start position:0% +our x-ray detector on one side of an +object + + align:start position:0% +object + + + align:start position:0% +object +and then we simply switch these sources + + align:start position:0% +and then we simply switch these sources + + + align:start position:0% +and then we simply switch these sources +at very high speed + + align:start position:0% +at very high speed + + + align:start position:0% +at very high speed +right because only one source can be on + + align:start position:0% +right because only one source can be on + + + align:start position:0% +right because only one source can be on +at a time or else we'll have two + + align:start position:0% +at a time or else we'll have two + + + align:start position:0% +at a time or else we'll have two +projections overlap + + align:start position:0% +projections overlap + + + align:start position:0% +projections overlap +right and so there are + + align:start position:0% +right and so there are + + + align:start position:0% +right and so there are +there's a limitation with this design is + + align:start position:0% +there's a limitation with this design is + + + align:start position:0% +there's a limitation with this design is +you have a limited angle right if you + + align:start position:0% +you have a limited angle right if you + + + align:start position:0% +you have a limited angle right if you +think about this as a ct scanner we've + + align:start position:0% +think about this as a ct scanner we've + + + align:start position:0% +think about this as a ct scanner we've +only gone over some small baseline but + + align:start position:0% +only gone over some small baseline but + + + align:start position:0% +only gone over some small baseline but +using modern tomography that's not such + + align:start position:0% +using modern tomography that's not such + + + align:start position:0% +using modern tomography that's not such +a big deal you can use limited baseline + + align:start position:0% +a big deal you can use limited baseline + + + align:start position:0% +a big deal you can use limited baseline +reconstruction + + align:start position:0% +reconstruction + + + align:start position:0% +reconstruction +uh and so the main limitation with this + + align:start position:0% +uh and so the main limitation with this + + + align:start position:0% +uh and so the main limitation with this +type of device is how fast you can + + align:start position:0% +type of device is how fast you can + + + align:start position:0% +type of device is how fast you can +switch + + align:start position:0% +switch + + + align:start position:0% +switch +the sources on and off it turns out it's + + align:start position:0% +the sources on and off it turns out it's + + + align:start position:0% +the sources on and off it turns out it's +very difficult and expensive to do that + + align:start position:0% +very difficult and expensive to do that + + + align:start position:0% +very difficult and expensive to do that +so what we'd like is to have an + + align:start position:0% +so what we'd like is to have an + + + align:start position:0% +so what we'd like is to have an +algorithm where we simply have + + align:start position:0% +algorithm where we simply have + + + align:start position:0% +algorithm where we simply have +an array of point sources on all the + + align:start position:0% +an array of point sources on all the + + + align:start position:0% +an array of point sources on all the +time + + align:start position:0% +time + + + align:start position:0% +time +right + + align:start position:0% +right + + + align:start position:0% +right +but what you'll have is on the detector + + align:start position:0% +but what you'll have is on the detector + + + align:start position:0% +but what you'll have is on the detector +you have a linear superposition you'll + + align:start position:0% +you have a linear superposition you'll + + + align:start position:0% +you have a linear superposition you'll +have more than one projection + + align:start position:0% +have more than one projection + + + align:start position:0% +have more than one projection +overlapping + + align:start position:0% +overlapping + + + align:start position:0% +overlapping +all right so now you have an interesting + + align:start position:0% +all right so now you have an interesting + + + align:start position:0% +all right so now you have an interesting +mathematical problem which is how do you + + align:start position:0% +mathematical problem which is how do you + + + align:start position:0% +mathematical problem which is how do you +invert + + align:start position:0% +invert + + + align:start position:0% +invert +those series of projections to get back + + align:start position:0% +those series of projections to get back + + + align:start position:0% +those series of projections to get back +to your tomographic data set and as the + + align:start position:0% +to your tomographic data set and as the + + + align:start position:0% +to your tomographic data set and as the +number of point sources increase that + + align:start position:0% +number of point sources increase that + + + align:start position:0% +number of point sources increase that +inversion becomes ill post and so what + + align:start position:0% +inversion becomes ill post and so what + + + align:start position:0% +inversion becomes ill post and so what +we did + + align:start position:0% +we did + + + align:start position:0% +we did +is we inserted + + align:start position:0% +is we inserted + + + align:start position:0% +is we inserted +a mask here + + align:start position:0% +a mask here + + + align:start position:0% +a mask here +and so by putting say some + + align:start position:0% +and so by putting say some + + + align:start position:0% +and so by putting say some +so this is basically a lead panel with + + align:start position:0% +so this is basically a lead panel with + + + align:start position:0% +so this is basically a lead panel with +holes drilled in + + align:start position:0% +holes drilled in + + + align:start position:0% +holes drilled in +and so now you can actually optimize + + align:start position:0% +and so now you can actually optimize + + + align:start position:0% +and so now you can actually optimize +this pattern of holes + + align:start position:0% +this pattern of holes + + + align:start position:0% +this pattern of holes +so that the inverse problem is well + + align:start position:0% +so that the inverse problem is well + + + align:start position:0% +so that the inverse problem is well +poked so again our goal is to get the + + align:start position:0% +poked so again our goal is to get the + + + align:start position:0% +poked so again our goal is to get the +set of projections but they're all + + align:start position:0% +set of projections but they're all + + + align:start position:0% +set of projections but they're all +overlapping so now we're going to design + + align:start position:0% +overlapping so now we're going to design + + + align:start position:0% +overlapping so now we're going to design +a mask to invert that system + + align:start position:0% +a mask to invert that system + + + align:start position:0% +a mask to invert that system +and so if you want to look at this we + + align:start position:0% +and so if you want to look at this we + + + align:start position:0% +and so if you want to look at this we +have a cigarette paper on this called + + align:start position:0% +have a cigarette paper on this called + + + align:start position:0% +have a cigarette paper on this called +shield fields but that's the basic ideas + + align:start position:0% +shield fields but that's the basic ideas + + + align:start position:0% +shield fields but that's the basic ideas +by putting this mask here you can invert + + align:start position:0% +by putting this mask here you can invert + + + align:start position:0% +by putting this mask here you can invert +the system and if you think about it + + align:start position:0% +the system and if you think about it + + + align:start position:0% +the system and if you think about it +very simply it's like a 3d tv you could + + align:start position:0% +very simply it's like a 3d tv you could + + + align:start position:0% +very simply it's like a 3d tv you could +put what's called a parallax barrier + + align:start position:0% +put what's called a parallax barrier + + + align:start position:0% +put what's called a parallax barrier +here so you just have a series of + + align:start position:0% +here so you just have a series of + + + align:start position:0% +here so you just have a series of +pinholes + + align:start position:0% +pinholes + + + align:start position:0% +pinholes +right + + align:start position:0% +right + + + align:start position:0% +right +and then if each pinhole was separated + + align:start position:0% +and then if each pinhole was separated + + + align:start position:0% +and then if each pinhole was separated +by the size of this the image of this + + align:start position:0% +by the size of this the image of this + + + align:start position:0% +by the size of this the image of this +array you just get an array of pinhole + + align:start position:0% +array you just get an array of pinhole + + + align:start position:0% +array you just get an array of pinhole +cameras and you could invert that system + + align:start position:0% +cameras and you could invert that system + + + align:start position:0% +cameras and you could invert that system +but of course that doesn't patch them + + align:start position:0% +but of course that doesn't patch them + + + align:start position:0% +but of course that doesn't patch them +with past much light so you can optimize + + align:start position:0% +with past much light so you can optimize + + + align:start position:0% +with past much light so you can optimize +and find better masks so + + align:start position:0% +and find better masks so + + + align:start position:0% +and find better masks so +because we don't like working with + + align:start position:0% +because we don't like working with + + + align:start position:0% +because we don't like working with +x-rays because they didn't want cancer + + align:start position:0% +x-rays because they didn't want cancer + + + align:start position:0% +x-rays because they didn't want cancer +we built this invisible wavelength and + + align:start position:0% +we built this invisible wavelength and + + + align:start position:0% +we built this invisible wavelength and +so what you can see is this is sort of + + align:start position:0% +so what you can see is this is sort of + + + align:start position:0% +so what you can see is this is sort of +like a ct scan scanner built for a + + align:start position:0% +like a ct scan scanner built for a + + + align:start position:0% +like a ct scan scanner built for a +hundred dollars so we have an array of + + align:start position:0% +hundred dollars so we have an array of + + + align:start position:0% +hundred dollars so we have an array of +leds which serves our x-ray sources + + align:start position:0% +leds which serves our x-ray sources + + + align:start position:0% +leds which serves our x-ray sources +we have an opaque object a wooden + + align:start position:0% +we have an opaque object a wooden + + + align:start position:0% +we have an opaque object a wooden +mannequin and then we have what + + align:start position:0% +mannequin and then we have what + + + align:start position:0% +mannequin and then we have what +simulates a large format sensor so this + + align:start position:0% +simulates a large format sensor so this + + + align:start position:0% +simulates a large format sensor so this +is a trick maybe some of you are using + + align:start position:0% +is a trick maybe some of you are using + + + align:start position:0% +is a trick maybe some of you are using +your homework as well to make a really + + align:start position:0% +your homework as well to make a really + + + align:start position:0% +your homework as well to make a really +large detector you can use a camera and + + align:start position:0% +large detector you can use a camera and + + + align:start position:0% +large detector you can use a camera and +just a sheet of paper held between glass + + align:start position:0% +just a sheet of paper held between glass + + + align:start position:0% +just a sheet of paper held between glass +right so we take a photo from behind if + + align:start position:0% +right so we take a photo from behind if + + + align:start position:0% +right so we take a photo from behind if +i was to turn one led one led on it see + + align:start position:0% +i was to turn one led one led on it see + + + align:start position:0% +i was to turn one led one led on it see +a shadow i get the picture of the + + align:start position:0% +a shadow i get the picture of the + + + align:start position:0% +a shadow i get the picture of the +shadows as if i had a giant sensor right + + align:start position:0% +shadows as if i had a giant sensor right + + + align:start position:0% +shadows as if i had a giant sensor right +so that's your cheap way of making huge + + align:start position:0% +so that's your cheap way of making huge + + + align:start position:0% +so that's your cheap way of making huge +sensors and then do we just put a thin + + align:start position:0% +sensors and then do we just put a thin + + + align:start position:0% +sensors and then do we just put a thin +sheet of glass here with our high + + align:start position:0% +sheet of glass here with our high + + + align:start position:0% +sheet of glass here with our high +frequency mask + + align:start position:0% +frequency mask + + + align:start position:0% +frequency mask +and so now we get to the computer vision + + align:start position:0% +and so now we get to the computer vision + + + align:start position:0% +and so now we get to the computer vision +problem so that's what it looks like + + align:start position:0% +problem so that's what it looks like + + + align:start position:0% +problem so that's what it looks like +when the lights are on + + align:start position:0% +when the lights are on + + + align:start position:0% +when the lights are on +so you can sort of see the multiplex + + align:start position:0% +so you can sort of see the multiplex + + + align:start position:0% +so you can sort of see the multiplex +shadows + + align:start position:0% + + + + align:start position:0% + +and then this is the magic pattern we + + align:start position:0% +and then this is the magic pattern we + + + align:start position:0% +and then this is the magic pattern we +actually used which + + align:start position:0% +actually used which + + + align:start position:0% +actually used which +you can see why if you read the paper + + align:start position:0% +you can see why if you read the paper + + + align:start position:0% +you can see why if you read the paper +but again if you just think about this + + align:start position:0% +but again if you just think about this + + + align:start position:0% +but again if you just think about this +as a mathematical problem we have a set + + align:start position:0% +as a mathematical problem we have a set + + + align:start position:0% +as a mathematical problem we have a set +of projections that are all superimposed + + align:start position:0% +of projections that are all superimposed + + + align:start position:0% +of projections that are all superimposed +we're trying to invert and get the + + align:start position:0% +we're trying to invert and get the + + + align:start position:0% +we're trying to invert and get the +individual shadows + + align:start position:0% +individual shadows + + + align:start position:0% +individual shadows +and it turns out by putting this high + + align:start position:0% +and it turns out by putting this high + + + align:start position:0% +and it turns out by putting this high +frequency pattern in that inversion + + align:start position:0% +frequency pattern in that inversion + + + align:start position:0% +frequency pattern in that inversion +becomes well posed so i'll leave it to + + align:start position:0% +becomes well posed so i'll leave it to + + + align:start position:0% +becomes well posed so i'll leave it to +you to think why that would be you can + + align:start position:0% +you to think why that would be you can + + + align:start position:0% +you to think why that would be you can +also if you go back to the previous + + align:start position:0% +also if you go back to the previous + + + align:start position:0% +also if you go back to the previous +image + + align:start position:0% +image + + + align:start position:0% +image +you can also think of this + + align:start position:0% +you can also think of this + + + align:start position:0% +you can also think of this +as as if you're standing in front of an + + align:start position:0% +as as if you're standing in front of an + + + align:start position:0% +as as if you're standing in front of an +x-ray machine + + align:start position:0% + + + + align:start position:0% + +and every one of those shadows + + align:start position:0% +and every one of those shadows + + + align:start position:0% +and every one of those shadows +would be the shadow you would get in + + align:start position:0% +would be the shadow you would get in + + + align:start position:0% +would be the shadow you would get in +front of the x-ray machine + + align:start position:0% +front of the x-ray machine + + + align:start position:0% +front of the x-ray machine +and as you move the extra source + + align:start position:0% +and as you move the extra source + + + align:start position:0% +and as you move the extra source +you will get + + align:start position:0% +you will get + + + align:start position:0% +you will get +one of the shards they will move + + align:start position:0% +one of the shards they will move + + + align:start position:0% +one of the shards they will move +except here all the sources are on at + + align:start position:0% +except here all the sources are on at + + + align:start position:0% +except here all the sources are on at +the same time + + align:start position:0% + + + + align:start position:0% + +since you're getting this simultaneous + + align:start position:0% +since you're getting this simultaneous + + + align:start position:0% +since you're getting this simultaneous +projection of the x-ray so the question + + align:start position:0% +projection of the x-ray so the question + + + align:start position:0% +projection of the x-ray so the question +is from this one photo + + align:start position:0% +is from this one photo + + + align:start position:0% +is from this one photo +how can i resolve all the original + + align:start position:0% +how can i resolve all the original + + + align:start position:0% +how can i resolve all the original +shadows right + + align:start position:0% +shadows right + + + align:start position:0% +shadows right +and so + + align:start position:0% +and so + + + align:start position:0% +and so +here you can see this is sort of what + + align:start position:0% +here you can see this is sort of what + + + align:start position:0% +here you can see this is sort of what +the data set looks like + + align:start position:0% +the data set looks like + + + align:start position:0% +the data set looks like +so you don't really see anything there + + align:start position:0% +so you don't really see anything there + + + align:start position:0% +so you don't really see anything there +but then just by inverting that system + + align:start position:0% +but then just by inverting that system + + + align:start position:0% +but then just by inverting that system +of equations you can actually pull out + + align:start position:0% +of equations you can actually pull out + + + align:start position:0% +of equations you can actually pull out +from that single image all the + + align:start position:0% +from that single image all the + + + align:start position:0% +from that single image all the +individual shadows so it's as if you had + + align:start position:0% +individual shadows so it's as if you had + + + align:start position:0% +individual shadows so it's as if you had +36 projections all in one image so the + + align:start position:0% +36 projections all in one image so the + + + align:start position:0% +36 projections all in one image so the +key advantage here is we never strobe + + align:start position:0% +key advantage here is we never strobe + + + align:start position:0% +key advantage here is we never strobe +the light so we can record this as fast + + align:start position:0% +the light so we can record this as fast + + + align:start position:0% +the light so we can record this as fast +as the camera can record images right so + + align:start position:0% +as the camera can record images right so + + + align:start position:0% +as the camera can record images right so +for really high speed tomography instead + + align:start position:0% +for really high speed tomography instead + + + align:start position:0% +for really high speed tomography instead +of rotating or strobing the light + + align:start position:0% +of rotating or strobing the light + + + align:start position:0% +of rotating or strobing the light +sources we can just have the light + + align:start position:0% +sources we can just have the light + + + align:start position:0% +sources we can just have the light +sources on all the time we're only + + align:start position:0% +sources on all the time we're only + + + align:start position:0% +sources on all the time we're only +limited by the frame rate of the camera + + align:start position:0% +limited by the frame rate of the camera + + + align:start position:0% +limited by the frame rate of the camera +then of course from these projections + + align:start position:0% +then of course from these projections + + + align:start position:0% +then of course from these projections +you can use the visual hole algorithm + + align:start position:0% +you can use the visual hole algorithm + + + align:start position:0% +you can use the visual hole algorithm +and reconstruct again this isn't exactly + + align:start position:0% +and reconstruct again this isn't exactly + + + align:start position:0% +and reconstruct again this isn't exactly +tomography because it's an opaque object + + align:start position:0% +tomography because it's an opaque object + + + align:start position:0% +tomography because it's an opaque object +but it's essentially the same idea + + align:start position:0% +but it's essentially the same idea + + + align:start position:0% +but it's essentially the same idea +you're doing that filtered back + + align:start position:0% +you're doing that filtered back + + + align:start position:0% +you're doing that filtered back +projection and so you get this + + align:start position:0% +projection and so you get this + + + align:start position:0% +projection and so you get this +reconstruction you can see + + align:start position:0% +reconstruction you can see + + + align:start position:0% +reconstruction you can see +you know looking at the mannequin + + align:start position:0% +you know looking at the mannequin + + + align:start position:0% +you know looking at the mannequin +there's sort of this starburst effect + + align:start position:0% +there's sort of this starburst effect + + + align:start position:0% +there's sort of this starburst effect +you described earlier where you have + + align:start position:0% +you described earlier where you have + + + align:start position:0% +you described earlier where you have +this phantom because of the limited bass + + align:start position:0% +this phantom because of the limited bass + + + align:start position:0% +this phantom because of the limited bass +line and so again that just has to do + + align:start position:0% +line and so again that just has to do + + + align:start position:0% +line and so again that just has to do +with the algorithm used to reconstruct + + align:start position:0% +with the algorithm used to reconstruct + + + align:start position:0% +with the algorithm used to reconstruct +if you had some prior on the smoothness + + align:start position:0% +if you had some prior on the smoothness + + + align:start position:0% +if you had some prior on the smoothness +of the object you could take that out + + align:start position:0% +of the object you could take that out + + + align:start position:0% +of the object you could take that out +but again + + align:start position:0% +but again + + + align:start position:0% +but again +usually you'd have to strobe those + + align:start position:0% +usually you'd have to strobe those + + + align:start position:0% +usually you'd have to strobe those +lights on and off so you'd have to take + + align:start position:0% +lights on and off so you'd have to take + + + align:start position:0% +lights on and off so you'd have to take +36 pictures here we just take one so + + align:start position:0% +36 pictures here we just take one so + + + align:start position:0% +36 pictures here we just take one so +that was the inspiration we took + + align:start position:0% +that was the inspiration we took + + + align:start position:0% +that was the inspiration we took +from the medical imaging world and it + + align:start position:0% +from the medical imaging world and it + + + align:start position:0% +from the medical imaging world and it +turns out all of this can be applied + + align:start position:0% +turns out all of this can be applied + + + align:start position:0% +turns out all of this can be applied +uh to take light field photographs which + + align:start position:0% +uh to take light field photographs which + + + align:start position:0% +uh to take light field photographs which +is what ramesh did in 2007 by putting + + align:start position:0% +is what ramesh did in 2007 by putting + + + align:start position:0% +is what ramesh did in 2007 by putting +that high frequency mask inside the + + align:start position:0% +that high frequency mask inside the + + + align:start position:0% +that high frequency mask inside the +camera so you can see all these ideas + + align:start position:0% +camera so you can see all these ideas + + + align:start position:0% +camera so you can see all these ideas +linked back together + + align:start position:0% +linked back together + + + align:start position:0% +linked back together +and they all start with tomography + + align:start position:0% +and they all start with tomography + + + align:start position:0% +and they all start with tomography +and so now let's take a quick plug uh we + + align:start position:0% +and so now let's take a quick plug uh we + + + align:start position:0% +and so now let's take a quick plug uh we +have a recent paper where we took this + + align:start position:0% +have a recent paper where we took this + + + align:start position:0% +have a recent paper where we took this +idea in yet another direction + + align:start position:0% +idea in yet another direction + + + align:start position:0% +idea in yet another direction +and so the idea is that we're going to + + align:start position:0% +and so the idea is that we're going to + + + align:start position:0% +and so the idea is that we're going to +build this device maybe step back and + + align:start position:0% +build this device maybe step back and + + + align:start position:0% +build this device maybe step back and +did the mat do a presentation have you + + align:start position:0% +did the mat do a presentation have you + + + align:start position:0% +did the mat do a presentation have you +already seen this yeah i think you + + align:start position:0% +already seen this yeah i think you + + + align:start position:0% +already seen this yeah i think you +should so you can go through it quickly + + align:start position:0% +should so you can go through it quickly + + + align:start position:0% +should so you can go through it quickly +okay so the basic idea make sure you can + + align:start position:0% +okay so the basic idea make sure you can + + + align:start position:0% +okay so the basic idea make sure you can +describe the connection between yeah so + + align:start position:0% +describe the connection between yeah so + + + align:start position:0% +describe the connection between yeah so +the basic idea is that we're going to + + align:start position:0% +the basic idea is that we're going to + + + align:start position:0% +the basic idea is that we're going to +take this and build an lcd screen that + + align:start position:0% +take this and build an lcd screen that + + + align:start position:0% +take this and build an lcd screen that +can sense depth and so the trick is + + align:start position:0% +can sense depth and so the trick is + + + align:start position:0% +can sense depth and so the trick is +pretty simple ignore the lcd screen + + align:start position:0% +pretty simple ignore the lcd screen + + + align:start position:0% +pretty simple ignore the lcd screen +we're just going to build the exact + + align:start position:0% +we're just going to build the exact + + + align:start position:0% +we're just going to build the exact +device i just described so we have an + + align:start position:0% +device i just described so we have an + + + align:start position:0% +device i just described so we have an +lcd panel instead of displaying an image + + align:start position:0% +lcd panel instead of displaying an image + + + align:start position:0% +lcd panel instead of displaying an image +we're just going to use it to display + + align:start position:0% +we're just going to use it to display + + + align:start position:0% +we're just going to use it to display +our pieces right no big surprise there + + align:start position:0% +our pieces right no big surprise there + + + align:start position:0% +our pieces right no big surprise there +instead of printing the mask we use the + + align:start position:0% +instead of printing the mask we use the + + + align:start position:0% +instead of printing the mask we use the +lcd to display a mask and then behind + + align:start position:0% +lcd to display a mask and then behind + + + align:start position:0% +lcd to display a mask and then behind +the liquid crystal panel we'll have a + + align:start position:0% +the liquid crystal panel we'll have a + + + align:start position:0% +the liquid crystal panel we'll have a +diffuser which inside lcds you already + + align:start position:0% +diffuser which inside lcds you already + + + align:start position:0% +diffuser which inside lcds you already +have diffusers behind liquid crystal and + + align:start position:0% +have diffusers behind liquid crystal and + + + align:start position:0% +have diffusers behind liquid crystal and +so again we'll have that that giant + + align:start position:0% +so again we'll have that that giant + + + align:start position:0% +so again we'll have that that giant +sensor right we'll have a diffuser our + + align:start position:0% +sensor right we'll have a diffuser our + + + align:start position:0% +sensor right we'll have a diffuser our +lcd panel and some cameras behind it + + align:start position:0% +lcd panel and some cameras behind it + + + align:start position:0% +lcd panel and some cameras behind it +and then we'll be photographing the + + align:start position:0% +and then we'll be photographing the + + + align:start position:0% +and then we'll be photographing the +world + + align:start position:0% +world + + + align:start position:0% +world +and so it actually turns out that you + + align:start position:0% +and so it actually turns out that you + + + align:start position:0% +and so it actually turns out that you +can capture the light field with that + + align:start position:0% +can capture the light field with that + + + align:start position:0% +can capture the light field with that +setup + + align:start position:0% +setup + + + align:start position:0% +setup +so by just building that setup + + align:start position:0% +so by just building that setup + + + align:start position:0% +so by just building that setup +using the lcd as a mask + + align:start position:0% +using the lcd as a mask + + + align:start position:0% +using the lcd as a mask +you can capture the light field and then + + align:start position:0% +you can capture the light field and then + + + align:start position:0% +you can capture the light field and then +you can just time multiplex oops let me + + align:start position:0% +you can just time multiplex oops let me + + + align:start position:0% +you can just time multiplex oops let me +go back + + align:start position:0% + + + + align:start position:0% + +right so + + align:start position:0% +right so + + + align:start position:0% +right so +on the first frame we turn the back + + align:start position:0% +on the first frame we turn the back + + + align:start position:0% +on the first frame we turn the back +light on and we use the lcd to display a + + align:start position:0% +light on and we use the lcd to display a + + + align:start position:0% +light on and we use the lcd to display a +picture on the next frame we turn the + + align:start position:0% +picture on the next frame we turn the + + + align:start position:0% +picture on the next frame we turn the +back light off and use the lcd to + + align:start position:0% +back light off and use the lcd to + + + align:start position:0% +back light off and use the lcd to +display a mask and get the light filled + + align:start position:0% +display a mask and get the light filled + + + align:start position:0% +display a mask and get the light filled +and repeat at very high frequencies so + + align:start position:0% +and repeat at very high frequencies so + + + align:start position:0% +and repeat at very high frequencies so +that your eye can't perceive it + + align:start position:0% +that your eye can't perceive it + + + align:start position:0% +that your eye can't perceive it +and so now you're getting an lcd panel + + align:start position:0% +and so now you're getting an lcd panel + + + align:start position:0% +and so now you're getting an lcd panel +that can do multi-touch like you + + align:start position:0% +that can do multi-touch like you + + + align:start position:0% +that can do multi-touch like you +normally see and then as the user moves + + align:start position:0% +normally see and then as the user moves + + + align:start position:0% +normally see and then as the user moves +the hand off the table + + align:start position:0% +the hand off the table + + + align:start position:0% +the hand off the table +you can sense depth + + align:start position:0% +you can sense depth + + + align:start position:0% +you can sense depth +and so now instead of having normal + + align:start position:0% +and so now instead of having normal + + + align:start position:0% +and so now instead of having normal +multi-touch you can also have a z-axis + + align:start position:0% +multi-touch you can also have a z-axis + + + align:start position:0% +multi-touch you can also have a z-axis +you can pull things off the table this + + align:start position:0% +you can pull things off the table this + + + align:start position:0% +you can pull things off the table this +is a very simple proof of concept demo + + align:start position:0% +is a very simple proof of concept demo + + + align:start position:0% +is a very simple proof of concept demo +but it shows that just that basic idea + + align:start position:0% +but it shows that just that basic idea + + + align:start position:0% +but it shows that just that basic idea +now we've gone into the hci direction + + align:start position:0% +now we've gone into the hci direction + + + align:start position:0% +now we've gone into the hci direction +here's again matt hirsch did all this + + align:start position:0% +here's again matt hirsch did all this + + + align:start position:0% +here's again matt hirsch did all this +work uh + + align:start position:0% +work uh + + + align:start position:0% +work uh +so you should really talk to him to see + + align:start position:0% +so you should really talk to him to see + + + align:start position:0% +so you should really talk to him to see +the demos and so we're presenting this + + align:start position:0% +the demos and so we're presenting this + + + align:start position:0% +the demos and so we're presenting this +at etec and cigarette asia so if you + + align:start position:0% +at etec and cigarette asia so if you + + + align:start position:0% +at etec and cigarette asia so if you +have any good ideas + + align:start position:0% +have any good ideas + + + align:start position:0% +have any good ideas +on demos you could use with the depth + + align:start position:0% +on demos you could use with the depth + + + align:start position:0% +on demos you could use with the depth +sensing screen please email me or matt + + align:start position:0% +sensing screen please email me or matt + + + align:start position:0% +sensing screen please email me or matt +and if you want to implement them all + + align:start position:0% +and if you want to implement them all + + + align:start position:0% +and if you want to implement them all +the better we'll give you credit when + + align:start position:0% +the better we'll give you credit when + + + align:start position:0% +the better we'll give you credit when +the reporters ask who is the clever guy + + align:start position:0% +the reporters ask who is the clever guy + + + align:start position:0% +the reporters ask who is the clever guy +who programmed that + + align:start position:0% +who programmed that + + + align:start position:0% +who programmed that +so here you can see just a very simple + + align:start position:0% +so here you can see just a very simple + + + align:start position:0% +so here you can see just a very simple +sort of cad explorer you can choose your + + align:start position:0% +sort of cad explorer you can choose your + + + align:start position:0% +sort of cad explorer you can choose your +model which is a touch interaction you + + align:start position:0% +model which is a touch interaction you + + + align:start position:0% +model which is a touch interaction you +can move your hand around it just + + align:start position:0% +can move your hand around it just + + + align:start position:0% +can move your hand around it just +controls the rotation translation and + + align:start position:0% +controls the rotation translation and + + + align:start position:0% +controls the rotation translation and +scale matrix being applied to that model + + align:start position:0% +scale matrix being applied to that model + + + align:start position:0% +scale matrix being applied to that model +right but again so what's neat here is + + align:start position:0% +right but again so what's neat here is + + + align:start position:0% +right but again so what's neat here is +you don't see any cameras there's + + align:start position:0% +you don't see any cameras there's + + + align:start position:0% +you don't see any cameras there's +nothing hidden in the bezel + + align:start position:0% +nothing hidden in the bezel + + + align:start position:0% +nothing hidden in the bezel +so it's so to the user it's sort of + + align:start position:0% +so it's so to the user it's sort of + + + align:start position:0% +so it's so to the user it's sort of +surprising that you're getting the light + + align:start position:0% +surprising that you're getting the light + + + align:start position:0% +surprising that you're getting the light +field and the demo i'm not showing is + + align:start position:0% +field and the demo i'm not showing is + + + align:start position:0% +field and the demo i'm not showing is +that you can do light field transfer + + align:start position:0% +that you can do light field transfer + + + align:start position:0% +that you can do light field transfer +with this if you know what that is + + align:start position:0% +with this if you know what that is + + + align:start position:0% +with this if you know what that is +we done okay on time uh + + align:start position:0% +we done okay on time uh + + + align:start position:0% +we done okay on time uh +can move faster so + + align:start position:0% +can move faster so + + + align:start position:0% +can move faster so +i think ank had already presented this + + align:start position:0% +i think ank had already presented this + + + align:start position:0% +i think ank had already presented this +project right yeah hey project it wasn't + + align:start position:0% +project right yeah hey project it wasn't + + + align:start position:0% +project right yeah hey project it wasn't +pretty slow okay so i'll just go through + + align:start position:0% +pretty slow okay so i'll just go through + + + align:start position:0% +pretty slow okay so i'll just go through +this really fast then so again i + + align:start position:0% +this really fast then so again i + + + align:start position:0% +this really fast then so again i +mentioned that once the computer was + + align:start position:0% +mentioned that once the computer was + + + align:start position:0% +mentioned that once the computer was +invented tomography became easy because + + align:start position:0% +invented tomography became easy because + + + align:start position:0% +invented tomography became easy because +they knew the radon transform and they + + align:start position:0% +they knew the radon transform and they + + + align:start position:0% +they knew the radon transform and they +could invert it but if you don't have a + + align:start position:0% +could invert it but if you don't have a + + + align:start position:0% +could invert it but if you don't have a +computer how can you take a + + align:start position:0% +computer how can you take a + + + align:start position:0% +computer how can you take a +cross-sectional cross-sectional image of + + align:start position:0% +cross-sectional cross-sectional image of + + + align:start position:0% +cross-sectional cross-sectional image of +a patient + + align:start position:0% +a patient + + + align:start position:0% +a patient +right so + + align:start position:0% +right so + + + align:start position:0% +right so +so if i just had an x-ray source and an + + align:start position:0% +so if i just had an x-ray source and an + + + align:start position:0% +so if i just had an x-ray source and an +x-ray film + + align:start position:0% +x-ray film + + + align:start position:0% +x-ray film +film and i had the patient sitting on + + align:start position:0% +film and i had the patient sitting on + + + align:start position:0% +film and i had the patient sitting on +the bernie i could turn the source on i + + align:start position:0% +the bernie i could turn the source on i + + + align:start position:0% +the bernie i could turn the source on i +did a projection + + align:start position:0% +did a projection + + + align:start position:0% +did a projection +but the main problem is every i'm really + + align:start position:0% +but the main problem is every i'm really + + + align:start position:0% +but the main problem is every i'm really +only interested in taking a + + align:start position:0% +only interested in taking a + + + align:start position:0% +only interested in taking a +cross-sectional image so i can identify + + align:start position:0% +cross-sectional image so i can identify + + + align:start position:0% +cross-sectional image so i can identify +a tumor in the brain or something else + + align:start position:0% +a tumor in the brain or something else + + + align:start position:0% +a tumor in the brain or something else +right but everything else out of that + + align:start position:0% +right but everything else out of that + + + align:start position:0% +right but everything else out of that +plane i don't really care about and the + + align:start position:0% +plane i don't really care about and the + + + align:start position:0% +plane i don't really care about and the +problem is if i just have this this + + align:start position:0% +problem is if i just have this this + + + align:start position:0% +problem is if i just have this this +perspective projection everything out of + + align:start position:0% +perspective projection everything out of + + + align:start position:0% +perspective projection everything out of +focus will also be imaged on the sensor + + align:start position:0% +focus will also be imaged on the sensor + + + align:start position:0% +focus will also be imaged on the sensor +right + + align:start position:0% +right + + + align:start position:0% +right +so the question is how can i get an + + align:start position:0% +so the question is how can i get an + + + align:start position:0% +so the question is how can i get an +image just through along a slice through + + align:start position:0% +image just through along a slice through + + + align:start position:0% +image just through along a slice through +my volume without using computation + + align:start position:0% +my volume without using computation + + + align:start position:0% +my volume without using computation +and so i think i could explain this but + + align:start position:0% +and so i think i could explain this but + + + align:start position:0% +and so i think i could explain this but +100 years ago this day they did this and + + align:start position:0% +100 years ago this day they did this and + + + align:start position:0% +100 years ago this day they did this and +it's called laminography and it gives + + align:start position:0% +it's called laminography and it gives + + + align:start position:0% +it's called laminography and it gives +you almost identical results purely with + + align:start position:0% +you almost identical results purely with + + + align:start position:0% +you almost identical results purely with +mechanical means so the idea is simple + + align:start position:0% +mechanical means so the idea is simple + + + align:start position:0% +mechanical means so the idea is simple +you simply take the x-ray source and you + + align:start position:0% +you simply take the x-ray source and you + + + align:start position:0% +you simply take the x-ray source and you +mechanically translate it from left to + + align:start position:0% +mechanically translate it from left to + + + align:start position:0% +mechanically translate it from left to +right + + align:start position:0% +right + + + align:start position:0% +right +and then at the same time you + + align:start position:0% +and then at the same time you + + + align:start position:0% +and then at the same time you +mechanically translate your film + + align:start position:0% +mechanically translate your film + + + align:start position:0% +mechanically translate your film +from right to left and so pick some + + align:start position:0% +from right to left and so pick some + + + align:start position:0% +from right to left and so pick some +point in the patient and be stationary + + align:start position:0% +point in the patient and be stationary + + + align:start position:0% +point in the patient and be stationary +right you'll have some ray going through + + align:start position:0% +right you'll have some ray going through + + + align:start position:0% +right you'll have some ray going through +that point + + align:start position:0% +that point + + + align:start position:0% +that point +right and then if i turn on the next + + align:start position:0% +right and then if i turn on the next + + + align:start position:0% +right and then if i turn on the next +source you'll have some other ray coming + + align:start position:0% +source you'll have some other ray coming + + + align:start position:0% +source you'll have some other ray coming +in as long as i move the sensor + + align:start position:0% +in as long as i move the sensor + + + align:start position:0% +in as long as i move the sensor +so that that same pixel is illuminated + + align:start position:0% +so that that same pixel is illuminated + + + align:start position:0% +so that that same pixel is illuminated +right then that point will be focused + + align:start position:0% +right then that point will be focused + + + align:start position:0% +right then that point will be focused +but everything else won't + + align:start position:0% +but everything else won't + + + align:start position:0% +but everything else won't +so it's sort of a clever trick to get a + + align:start position:0% +so it's sort of a clever trick to get a + + + align:start position:0% +so it's sort of a clever trick to get a +ct scanner without any computers and so + + align:start position:0% +ct scanner without any computers and so + + + align:start position:0% +ct scanner without any computers and so +we use this uh to publish the paper and + + align:start position:0% +we use this uh to publish the paper and + + + align:start position:0% +we use this uh to publish the paper and +icc actually let's go back to that one + + align:start position:0% +icc actually let's go back to that one + + + align:start position:0% +icc actually let's go back to that one +there's a there's a minor difference + + align:start position:0% +there's a there's a minor difference + + + align:start position:0% +there's a there's a minor difference +though between + + align:start position:0% +though between + + + align:start position:0% +though between +between doing this + + align:start position:0% +between doing this + + + align:start position:0% +between doing this +achieving a cross-section image + + align:start position:0% +achieving a cross-section image + + + align:start position:0% +achieving a cross-section image +through this method versus doing the + + align:start position:0% +through this method versus doing the + + + align:start position:0% +through this method versus doing the +whole + + align:start position:0% +whole + + + align:start position:0% +whole +spinning and multiple projection thing + + align:start position:0% +spinning and multiple projection thing + + + align:start position:0% +spinning and multiple projection thing +what's the difference between the two + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so you don't get as much depth + + align:start position:0% +so you don't get as much depth + + + align:start position:0% +so you don't get as much depth +by what + + align:start position:0% +by what + + + align:start position:0% +by what +the plane of focus but you can control + + align:start position:0% +the plane of focus but you can control + + + align:start position:0% +the plane of focus but you can control +that based on how far how close the + + align:start position:0% +that based on how far how close the + + + align:start position:0% +that based on how far how close the +x-ray source and the sensor is so you + + align:start position:0% +x-ray source and the sensor is so you + + + align:start position:0% +x-ray source and the sensor is so you +can get a pretty narrow depth of field + + align:start position:0% +can get a pretty narrow depth of field + + + align:start position:0% +can get a pretty narrow depth of field +but what happens to stuff that's outside + + align:start position:0% +but what happens to stuff that's outside + + + align:start position:0% +but what happens to stuff that's outside +the depth of field + + align:start position:0% +the depth of field + + + align:start position:0% +the depth of field +it's still going to be blurred yeah and + + align:start position:0% +it's still going to be blurred yeah and + + + align:start position:0% +it's still going to be blurred yeah and +it will be still part of the image so + + align:start position:0% +it will be still part of the image so + + + align:start position:0% +it will be still part of the image so +you don't really eliminate + + align:start position:0% +you don't really eliminate + + + align:start position:0% +you don't really eliminate +what's above and below your plane of + + align:start position:0% +what's above and below your plane of + + + align:start position:0% +what's above and below your plane of +focus it's just + + align:start position:0% +focus it's just + + + align:start position:0% +focus it's just +out of focus but it's still there very + + align:start position:0% +out of focus but it's still there very + + + align:start position:0% +out of focus but it's still there very +fortunate you can make it stronger out + + align:start position:0% +fortunate you can make it stronger out + + + align:start position:0% +fortunate you can make it stronger out +of focus but your contrast will be lower + + align:start position:0% +of focus but your contrast will be lower + + + align:start position:0% +of focus but your contrast will be lower +than ct + + align:start position:0% +than ct + + + align:start position:0% +than ct +right + + align:start position:0% +right + + + align:start position:0% +right +so + + align:start position:0% +so + + + align:start position:0% +so +ankit + + align:start position:0% +ankit + + + align:start position:0% +ankit +had a great idea to apply this to uh to + + align:start position:0% +had a great idea to apply this to uh to + + + align:start position:0% +had a great idea to apply this to uh to +photography and so he's going to explain + + align:start position:0% +photography and so he's going to explain + + + align:start position:0% +photography and so he's going to explain +this to you so i'll go quickly through + + align:start position:0% +this to you so i'll go quickly through + + + align:start position:0% +this to you so i'll go quickly through +this but the basic idea is if i have my + + align:start position:0% +this but the basic idea is if i have my + + + align:start position:0% +this but the basic idea is if i have my +normal thin lens equation i have some + + align:start position:0% +normal thin lens equation i have some + + + align:start position:0% +normal thin lens equation i have some +plane in the world on the left and my + + align:start position:0% +plane in the world on the left and my + + + align:start position:0% +plane in the world on the left and my +sensor on the right the lens maps those + + align:start position:0% +sensor on the right the lens maps those + + + align:start position:0% +sensor on the right the lens maps those +and as i make as i stop down the + + align:start position:0% +and as i make as i stop down the + + + align:start position:0% +and as i make as i stop down the +aperture + + align:start position:0% +aperture + + + align:start position:0% +aperture +right the blur circle for the auto focus + + align:start position:0% +right the blur circle for the auto focus + + + align:start position:0% +right the blur circle for the auto focus +point decreases and in the limit if i + + align:start position:0% +point decreases and in the limit if i + + + align:start position:0% +point decreases and in the limit if i +just have a pinhole then i get + + align:start position:0% +just have a pinhole then i get + + + align:start position:0% +just have a pinhole then i get +everything in the world in focus and so + + align:start position:0% +everything in the world in focus and so + + + align:start position:0% +everything in the world in focus and so +if you look at your iphone camera your + + align:start position:0% +if you look at your iphone camera your + + + align:start position:0% +if you look at your iphone camera your +cell phone camera the apertures are so + + align:start position:0% +cell phone camera the apertures are so + + + align:start position:0% +cell phone camera the apertures are so +small that you're essentially taking + + align:start position:0% +small that you're essentially taking + + + align:start position:0% +small that you're essentially taking +pinhole images for everything right and + + align:start position:0% +pinhole images for everything right and + + + align:start position:0% +pinhole images for everything right and +what we'd like to do is take images with + + align:start position:0% +what we'd like to do is take images with + + + align:start position:0% +what we'd like to do is take images with +a cell phone camera that are as if they + + align:start position:0% +a cell phone camera that are as if they + + + align:start position:0% +a cell phone camera that are as if they +have a large lens because really when + + align:start position:0% +have a large lens because really when + + + align:start position:0% +have a large lens because really when +you pay a professional photographer to + + align:start position:0% +you pay a professional photographer to + + + align:start position:0% +you pay a professional photographer to +do your wedding photos it's really the + + align:start position:0% +do your wedding photos it's really the + + + align:start position:0% +do your wedding photos it's really the +blur one of the the blur is one of the + + align:start position:0% +blur one of the the blur is one of the + + + align:start position:0% +blur one of the the blur is one of the +big tricks they have right they take a + + align:start position:0% +big tricks they have right they take a + + + align:start position:0% +big tricks they have right they take a +painful blur you're paying for the blur + + align:start position:0% +painful blur you're paying for the blur + + + align:start position:0% +painful blur you're paying for the blur +in a way you're playing you're paying + + align:start position:0% +in a way you're playing you're paying + + + align:start position:0% +in a way you're playing you're paying +for that big piece of glass and a bit of + + align:start position:0% +for that big piece of glass and a bit of + + + align:start position:0% +for that big piece of glass and a bit of +the talent to focus on the foreground + + align:start position:0% +the talent to focus on the foreground + + + align:start position:0% +the talent to focus on the foreground +object so the background has this really + + align:start position:0% +object so the background has this really + + + align:start position:0% +object so the background has this really +beautiful blur right that's one of the + + align:start position:0% +beautiful blur right that's one of the + + + align:start position:0% +beautiful blur right that's one of the +things that you immediately noticed when + + align:start position:0% +things that you immediately noticed when + + + align:start position:0% +things that you immediately noticed when +you look at a wedding i was like oh gee + + align:start position:0% +you look at a wedding i was like oh gee + + + align:start position:0% +you look at a wedding i was like oh gee +they just blurred the background great + + align:start position:0% +they just blurred the background great + + + align:start position:0% +they just blurred the background great +right so the question is can we get nice + + align:start position:0% +right so the question is can we get nice + + + align:start position:0% +right so the question is can we get nice +defocus + + align:start position:0% +defocus + + + align:start position:0% +defocus +nice blur with a cell phone camera so in + + align:start position:0% +nice blur with a cell phone camera so in + + + align:start position:0% +nice blur with a cell phone camera so in +a way we're going to make our camera + + align:start position:0% +a way we're going to make our camera + + + align:start position:0% +a way we're going to make our camera +worse right a cell phone camera takes + + align:start position:0% +worse right a cell phone camera takes + + + align:start position:0% +worse right a cell phone camera takes +everything in focus which you know maybe + + align:start position:0% +everything in focus which you know maybe + + + align:start position:0% +everything in focus which you know maybe +that's a good thing but it doesn't have + + align:start position:0% +that's a good thing but it doesn't have + + + align:start position:0% +that's a good thing but it doesn't have +that aesthetic feel of having a nice + + align:start position:0% +that aesthetic feel of having a nice + + + align:start position:0% +that aesthetic feel of having a nice +defocused background + + align:start position:0% +defocused background + + + align:start position:0% +defocused background +and so the main trick again i'll credit + + align:start position:0% +and so the main trick again i'll credit + + + align:start position:0% +and so the main trick again i'll credit +with this is a nice insight is uh well + + align:start position:0% +with this is a nice insight is uh well + + + align:start position:0% +with this is a nice insight is uh well +first let's consider moving the pinhole + + align:start position:0% +first let's consider moving the pinhole + + + align:start position:0% +first let's consider moving the pinhole +because we just talked about + + align:start position:0% +because we just talked about + + + align:start position:0% +because we just talked about +laminography and that's like moving the + + align:start position:0% +laminography and that's like moving the + + + align:start position:0% +laminography and that's like moving the +x-ray source so our pinhole here is like + + align:start position:0% +x-ray source so our pinhole here is like + + + align:start position:0% +x-ray source so our pinhole here is like +our x-ray source it's our center of + + align:start position:0% +our x-ray source it's our center of + + + align:start position:0% +our x-ray source it's our center of +projection and so if you translate a + + align:start position:0% +projection and so if you translate a + + + align:start position:0% +projection and so if you translate a +pinhole + + align:start position:0% +pinhole + + + align:start position:0% +pinhole +right and again we have two two points + + align:start position:0% +right and again we have two two points + + + align:start position:0% +right and again we have two two points +in the world they're mapped onto our + + align:start position:0% +in the world they're mapped onto our + + + align:start position:0% +in the world they're mapped onto our +sensor nothing's moving other than the + + align:start position:0% +sensor nothing's moving other than the + + + align:start position:0% +sensor nothing's moving other than the +pinhole + + align:start position:0% +pinhole + + + align:start position:0% +pinhole +then you see that that + + align:start position:0% +then you see that that + + + align:start position:0% +then you see that that +without without moving the sensor you + + align:start position:0% +without without moving the sensor you + + + align:start position:0% +without without moving the sensor you +get these two blur circles + + align:start position:0% +get these two blur circles + + + align:start position:0% +get these two blur circles +but one of them + + align:start position:0% +but one of them + + + align:start position:0% +but one of them +is slightly larger + + align:start position:0% +is slightly larger + + + align:start position:0% +is slightly larger +right + + align:start position:0% +right + + + align:start position:0% +right +and so again in the interest of saving + + align:start position:0% +and so again in the interest of saving + + + align:start position:0% +and so again in the interest of saving +time you can go through a mathematical + + align:start position:0% +time you can go through a mathematical + + + align:start position:0% +time you can go through a mathematical +analysis but what's really important + + align:start position:0% +analysis but what's really important + + + align:start position:0% +analysis but what's really important +here is it's the same idea + + align:start position:0% +here is it's the same idea + + + align:start position:0% +here is it's the same idea +as laminography applied to c to + + align:start position:0% +as laminography applied to c to + + + align:start position:0% +as laminography applied to c to +to x-rays is basically this is like our + + align:start position:0% +to x-rays is basically this is like our + + + align:start position:0% +to x-rays is basically this is like our +x-ray source this is like our film plane + + align:start position:0% +x-ray source this is like our film plane + + + align:start position:0% +x-ray source this is like our film plane +and if we translate them + + align:start position:0% +and if we translate them + + + align:start position:0% +and if we translate them +at a certain velocity ratio we can + + align:start position:0% +at a certain velocity ratio we can + + + align:start position:0% +at a certain velocity ratio we can +actually put certain planes in the world + + align:start position:0% +actually put certain planes in the world + + + align:start position:0% +actually put certain planes in the world +into focus it's as if our patient has + + align:start position:0% +into focus it's as if our patient has + + + align:start position:0% +into focus it's as if our patient has +moved to the left side instead of the + + align:start position:0% +moved to the left side instead of the + + + align:start position:0% +moved to the left side instead of the +center now we have the x-ray source and + + align:start position:0% +center now we have the x-ray source and + + + align:start position:0% +center now we have the x-ray source and +the film and the velocity now becomes in + + align:start position:0% +the film and the velocity now becomes in + + + align:start position:0% +the film and the velocity now becomes in +the same direction instead of opposite + + align:start position:0% +the same direction instead of opposite + + + align:start position:0% +the same direction instead of opposite +directions but if you think about this + + align:start position:0% +directions but if you think about this + + + align:start position:0% +directions but if you think about this +it's identical + + align:start position:0% +it's identical + + + align:start position:0% +it's identical +right it's identical to the laminography + + align:start position:0% +right it's identical to the laminography + + + align:start position:0% +right it's identical to the laminography +we saw earlier and so then what we can + + align:start position:0% +we saw earlier and so then what we can + + + align:start position:0% +we saw earlier and so then what we can +do is we can just choose this velocity + + align:start position:0% +do is we can just choose this velocity + + + align:start position:0% +do is we can just choose this velocity +ratio + + align:start position:0% +ratio + + + align:start position:0% +ratio +and again if you say look at the blue + + align:start position:0% +and again if you say look at the blue + + + align:start position:0% +and again if you say look at the blue +ray here + + align:start position:0% +ray here + + + align:start position:0% +ray here +it'll always move to the same pixel on + + align:start position:0% +it'll always move to the same pixel on + + + align:start position:0% +it'll always move to the same pixel on +the sensor because we're moving the + + align:start position:0% +the sensor because we're moving the + + + align:start position:0% +the sensor because we're moving the +sensor at just the right speed so that + + align:start position:0% +sensor at just the right speed so that + + + align:start position:0% +sensor at just the right speed so that +that pixel always stays on the blu-ray + + align:start position:0% +that pixel always stays on the blu-ray + + + align:start position:0% +that pixel always stays on the blu-ray +but the blue one is getting the the red + + align:start position:0% +but the blue one is getting the the red + + + align:start position:0% +but the blue one is getting the the red +one is getting blurred right and by + + align:start position:0% +one is getting blurred right and by + + + align:start position:0% +one is getting blurred right and by +changing that velocity ratio we can then + + align:start position:0% +changing that velocity ratio we can then + + + align:start position:0% +changing that velocity ratio we can then +focus at a different point right very + + align:start position:0% +focus at a different point right very + + + align:start position:0% +focus at a different point right very +simple idea + + align:start position:0% +simple idea + + + align:start position:0% +simple idea +and so if you look in the paper what + + align:start position:0% +and so if you look in the paper what + + + align:start position:0% +and so if you look in the paper what +we've done is just recreated what a lens + + align:start position:0% +we've done is just recreated what a lens + + + align:start position:0% +we've done is just recreated what a lens +does but over time and so everyone knows + + align:start position:0% +does but over time and so everyone knows + + + align:start position:0% +does but over time and so everyone knows +this equation the gaussian thin lens + + align:start position:0% +this equation the gaussian thin lens + + + align:start position:0% +this equation the gaussian thin lens +equation right that the distance to the + + align:start position:0% +equation right that the distance to the + + + align:start position:0% +equation right that the distance to the +image plane and the object plane our + + align:start position:0% +image plane and the object plane our + + + align:start position:0% +image plane and the object plane our +inverse reciprocal is equal to the focal + + align:start position:0% +inverse reciprocal is equal to the focal + + + align:start position:0% +inverse reciprocal is equal to the focal +length right hopefully everyone knows + + align:start position:0% +length right hopefully everyone knows + + + align:start position:0% +length right hopefully everyone knows +that + + align:start position:0% +that + + + align:start position:0% +that +so normally this focal length is chosen + + align:start position:0% +so normally this focal length is chosen + + + align:start position:0% +so normally this focal length is chosen +by is selected by your chunk of glass + + align:start position:0% +by is selected by your chunk of glass + + + align:start position:0% +by is selected by your chunk of glass +right you choose some refractive index + + align:start position:0% +right you choose some refractive index + + + align:start position:0% +right you choose some refractive index +and some curvatures that gives you the + + align:start position:0% +and some curvatures that gives you the + + + align:start position:0% +and some curvatures that gives you the +focal length here + + align:start position:0% +focal length here + + + align:start position:0% +focal length here +you have a virtual focal length which is + + align:start position:0% +you have a virtual focal length which is + + + align:start position:0% +you have a virtual focal length which is +just simply + + align:start position:0% +just simply + + + align:start position:0% +just simply +it's very simple it's the register + + align:start position:0% +it's very simple it's the register + + + align:start position:0% +it's very simple it's the register +distance + + align:start position:0% +distance + + + align:start position:0% +distance +which is the distance to your pinhole to + + align:start position:0% +which is the distance to your pinhole to + + + align:start position:0% +which is the distance to your pinhole to +the sensor times the velocity ratio so + + align:start position:0% +the sensor times the velocity ratio so + + + align:start position:0% +the sensor times the velocity ratio so +as we change this velocity ratio we can + + align:start position:0% +as we change this velocity ratio we can + + + align:start position:0% +as we change this velocity ratio we can +make arbitrary lenses + + align:start position:0% +make arbitrary lenses + + + align:start position:0% +make arbitrary lenses +and that gives us a virtual f number and + + align:start position:0% +and that gives us a virtual f number and + + + align:start position:0% +and that gives us a virtual f number and +so then just to blow through this this + + align:start position:0% +so then just to blow through this this + + + align:start position:0% +so then just to blow through this this +is the prototype we built so again you + + align:start position:0% +is the prototype we built so again you + + + align:start position:0% +is the prototype we built so again you +can see the story here we knew about + + align:start position:0% +can see the story here we knew about + + + align:start position:0% +can see the story here we knew about +laminography which is a medical imaging + + align:start position:0% +laminography which is a medical imaging + + + align:start position:0% +laminography which is a medical imaging +topic we said we want to publish + + align:start position:0% +topic we said we want to publish + + + align:start position:0% +topic we said we want to publish +something in computational photography + + align:start position:0% +something in computational photography + + + align:start position:0% +something in computational photography +let's build an optical version and here + + align:start position:0% +let's build an optical version and here + + + align:start position:0% +let's build an optical version and here +you go + + align:start position:0% +you go + + + align:start position:0% +you go +so you have two translation stages right + + align:start position:0% +so you have two translation stages right + + + align:start position:0% +so you have two translation stages right +you can see those on the bottom these + + align:start position:0% +you can see those on the bottom these + + + align:start position:0% +you can see those on the bottom these +are from quinn + + align:start position:0% +are from quinn + + + align:start position:0% +are from quinn +and then we have lens and sensor + + align:start position:0% +and then we have lens and sensor + + + align:start position:0% +and then we have lens and sensor +and then you can see this is the type of + + align:start position:0% +and then you can see this is the type of + + + align:start position:0% +and then you can see this is the type of +image if you stop down the lens this is + + align:start position:0% +image if you stop down the lens this is + + + align:start position:0% +image if you stop down the lens this is +what your cell phone would give you + + align:start position:0% +what your cell phone would give you + + + align:start position:0% +what your cell phone would give you +and then by adjusting the velocity ratio + + align:start position:0% +and then by adjusting the velocity ratio + + + align:start position:0% +and then by adjusting the velocity ratio +by making it small we can focus on the + + align:start position:0% +by making it small we can focus on the + + + align:start position:0% +by making it small we can focus on the +foreground + + align:start position:0% +foreground + + + align:start position:0% +foreground +the middle or the background and so that + + align:start position:0% +the middle or the background and so that + + + align:start position:0% +the middle or the background and so that +you know we're only getting blurred 1d + + align:start position:0% +you know we're only getting blurred 1d + + + align:start position:0% +you know we're only getting blurred 1d +here so there's some more complexity but + + align:start position:0% +here so there's some more complexity but + + + align:start position:0% +here so there's some more complexity but +that's the basic idea right so you see + + align:start position:0% +that's the basic idea right so you see + + + align:start position:0% +that's the basic idea right so you see +that path we start with medical imaging + + align:start position:0% +that path we start with medical imaging + + + align:start position:0% +that path we start with medical imaging +we publish a paper in uh and not + + align:start position:0% +we publish a paper in uh and not + + + align:start position:0% +we publish a paper in uh and not +siggraph but a graphics journal it's + + align:start position:0% +siggraph but a graphics journal it's + + + align:start position:0% +siggraph but a graphics journal it's +pretty pretty straightforward algorithm + + align:start position:0% +pretty pretty straightforward algorithm + + + align:start position:0% +pretty pretty straightforward algorithm +and so now just to finish up tomography + + align:start position:0% +and so now just to finish up tomography + + + align:start position:0% +and so now just to finish up tomography +uh you know applying it to optics like + + align:start position:0% +uh you know applying it to optics like + + + align:start position:0% +uh you know applying it to optics like +we did is obvious it's also obvious how + + align:start position:0% +we did is obvious it's also obvious how + + + align:start position:0% +we did is obvious it's also obvious how +you would apply this to other + + align:start position:0% +you would apply this to other + + + align:start position:0% +you would apply this to other +applications so this + + align:start position:0% +applications so this + + + align:start position:0% +applications so this +this is an acoustic version of + + align:start position:0% +this is an acoustic version of + + + align:start position:0% +this is an acoustic version of +tomography because we're just changing + + align:start position:0% +tomography because we're just changing + + + align:start position:0% +tomography because we're just changing +the wavelength in a way + + align:start position:0% +the wavelength in a way + + + align:start position:0% +the wavelength in a way +and so the idea is that say we have some + + align:start position:0% +and so the idea is that say we have some + + + align:start position:0% +and so the idea is that say we have some +underground region we're looking for oil + + align:start position:0% +underground region we're looking for oil + + + align:start position:0% +underground region we're looking for oil +deposits or more noble things like + + align:start position:0% +deposits or more noble things like + + + align:start position:0% +deposits or more noble things like +looking for the skeletons or dinosaurs + + align:start position:0% +looking for the skeletons or dinosaurs + + + align:start position:0% +looking for the skeletons or dinosaurs +and so uh to to find + + align:start position:0% +and so uh to to find + + + align:start position:0% +and so uh to to find +the density function it's very easy you + + align:start position:0% +the density function it's very easy you + + + align:start position:0% +the density function it's very easy you +just set up a set of explosive charges + + align:start position:0% +just set up a set of explosive charges + + + align:start position:0% +just set up a set of explosive charges +right those are going to generate + + align:start position:0% +right those are going to generate + + + align:start position:0% +right those are going to generate +pressure + + align:start position:0% +pressure + + + align:start position:0% +pressure +pressure waves + + align:start position:0% +pressure waves + + + align:start position:0% +pressure waves +and they're going to travel hopefully if + + align:start position:0% +and they're going to travel hopefully if + + + align:start position:0% +and they're going to travel hopefully if +we do things correctly and we model it + + align:start position:0% +we do things correctly and we model it + + + align:start position:0% +we do things correctly and we model it +if we if we select things right then + + align:start position:0% +if we if we select things right then + + + align:start position:0% +if we if we select things right then +they mostly travel on ballistic paths to + + align:start position:0% +they mostly travel on ballistic paths to + + + align:start position:0% +they mostly travel on ballistic paths to +a series of microphones + + align:start position:0% +a series of microphones + + + align:start position:0% +a series of microphones +and then again we can just treat this as + + align:start position:0% +and then again we can just treat this as + + + align:start position:0% +and then again we can just treat this as +a limited baseline tomography and invert + + align:start position:0% +a limited baseline tomography and invert + + + align:start position:0% +a limited baseline tomography and invert +that system and here at each pixel or + + align:start position:0% +that system and here at each pixel or + + + align:start position:0% +that system and here at each pixel or +voxel we're reconstructing the velocity + + align:start position:0% +voxel we're reconstructing the velocity + + + align:start position:0% +voxel we're reconstructing the velocity +right because the velocity is + + align:start position:0% +right because the velocity is + + + align:start position:0% +right because the velocity is +proportional to the density of the + + align:start position:0% +proportional to the density of the + + + align:start position:0% +proportional to the density of the +material + + align:start position:0% +material + + + align:start position:0% +material +and so then we can reconstruct + + align:start position:0% +and so then we can reconstruct + + + align:start position:0% +and so then we can reconstruct +underground objects + + align:start position:0% +underground objects + + + align:start position:0% +underground objects +using tomography using explosives and + + align:start position:0% +using tomography using explosives and + + + align:start position:0% +using tomography using explosives and +microphones sort of cool idea + + align:start position:0% +microphones sort of cool idea + + + align:start position:0% +microphones sort of cool idea +so you can do this for for anything you + + align:start position:0% +so you can do this for for anything you + + + align:start position:0% +so you can do this for for anything you +can do this + + align:start position:0% +can do this + + + align:start position:0% +can do this +not just underground but + + align:start position:0% +not just underground but + + + align:start position:0% +not just underground but +this is how ultrasonic works as well + + align:start position:0% +this is how ultrasonic works as well + + + align:start position:0% +this is how ultrasonic works as well +ultrasound + + align:start position:0% +ultrasound + + + align:start position:0% +ultrasound +ultrasound scanners right + + align:start position:0% +ultrasound scanners right + + + align:start position:0% +ultrasound scanners right +and so then rock avoid proposed this in + + align:start position:0% +and so then rock avoid proposed this in + + + align:start position:0% +and so then rock avoid proposed this in +the course which which i always liked + + align:start position:0% +the course which which i always liked + + + align:start position:0% +the course which which i always liked +which was + + align:start position:0% +which was + + + align:start position:0% +which was +if you could convince the the italians + + align:start position:0% +if you could convince the the italians + + + align:start position:0% +if you could convince the the italians +that you can set up some explosive + + align:start position:0% +that you can set up some explosive + + + align:start position:0% +that you can set up some explosive +charges on their subway which they might + + align:start position:0% +charges on their subway which they might + + + align:start position:0% +charges on their subway which they might +have concerns with and use some + + align:start position:0% +have concerns with and use some + + + align:start position:0% +have concerns with and use some +microphones and you might be able to + + align:start position:0% +microphones and you might be able to + + + align:start position:0% +microphones and you might be able to +reconstruct uh underground rome + + align:start position:0% +reconstruct uh underground rome + + + align:start position:0% +reconstruct uh underground rome +uh just from that algorithm at least a + + align:start position:0% +uh just from that algorithm at least a + + + align:start position:0% +uh just from that algorithm at least a +rough estimate and so it's not bad i + + align:start position:0% +rough estimate and so it's not bad i + + + align:start position:0% +rough estimate and so it's not bad i +mean if you go out to these + + align:start position:0% +mean if you go out to these + + + align:start position:0% +mean if you go out to these +archaeological sites they're huge and + + align:start position:0% +archaeological sites they're huge and + + + align:start position:0% +archaeological sites they're huge and +they all often discover new sites + + align:start position:0% +they all often discover new sites + + + align:start position:0% +they all often discover new sites +underground and so this is another way + + align:start position:0% +underground and so this is another way + + + align:start position:0% +underground and so this is another way +to compete with uh with other scanning + + align:start position:0% +to compete with uh with other scanning + + + align:start position:0% +to compete with uh with other scanning +technologies it's very inexpensive and + + align:start position:0% +technologies it's very inexpensive and + + + align:start position:0% +technologies it's very inexpensive and +so then as long as i'm doing okay on + + align:start position:0% +so then as long as i'm doing okay on + + + align:start position:0% +so then as long as i'm doing okay on +time i'll quickly blow through yeah go + + align:start position:0% +time i'll quickly blow through yeah go + + + align:start position:0% +time i'll quickly blow through yeah go +ahead so + + align:start position:0% +ahead so + + + align:start position:0% +ahead so +we started with tomography which assumes + + align:start position:0% +we started with tomography which assumes + + + align:start position:0% +we started with tomography which assumes +everything travels on a ballistic path + + align:start position:0% +everything travels on a ballistic path + + + align:start position:0% +everything travels on a ballistic path +and so now let's start loosening our + + align:start position:0% +and so now let's start loosening our + + + align:start position:0% +and so now let's start loosening our +assumption on that ballistic path right + + align:start position:0% +assumption on that ballistic path right + + + align:start position:0% +assumption on that ballistic path right +so the first assumption is let's allow + + align:start position:0% +so the first assumption is let's allow + + + align:start position:0% +so the first assumption is let's allow +things to refract so instead of having + + align:start position:0% +things to refract so instead of having + + + align:start position:0% +things to refract so instead of having +an object with just just attenuates rays + + align:start position:0% +an object with just just attenuates rays + + + align:start position:0% +an object with just just attenuates rays +let's assume we have like a lens here + + align:start position:0% +let's assume we have like a lens here + + + align:start position:0% +let's assume we have like a lens here +that's going to bend raise and diffract + + align:start position:0% +that's going to bend raise and diffract + + + align:start position:0% +that's going to bend raise and diffract +them slightly right so we have weakly + + align:start position:0% +them slightly right so we have weakly + + + align:start position:0% +them slightly right so we have weakly +refractive media + + align:start position:0% +refractive media + + + align:start position:0% +refractive media +right so we've made this we've loosened + + align:start position:0% +right so we've made this we've loosened + + + align:start position:0% +right so we've made this we've loosened +it the prior model of the object so if + + align:start position:0% +it the prior model of the object so if + + + align:start position:0% +it the prior model of the object so if +you try applying the the inverse radon + + align:start position:0% +you try applying the the inverse radon + + + align:start position:0% +you try applying the the inverse radon +transform to the data set you gather it + + align:start position:0% +transform to the data set you gather it + + + align:start position:0% +transform to the data set you gather it +turns out we won't be able to + + align:start position:0% +turns out we won't be able to + + + align:start position:0% +turns out we won't be able to +reconstruct this + + align:start position:0% +reconstruct this + + + align:start position:0% +reconstruct this +right that assumption that things will + + align:start position:0% +right that assumption that things will + + + align:start position:0% +right that assumption that things will +move on ballistic paths is essential now + + align:start position:0% +move on ballistic paths is essential now + + + align:start position:0% +move on ballistic paths is essential now +there's some interesting work recently + + align:start position:0% +there's some interesting work recently + + + align:start position:0% +there's some interesting work recently +sigograph on schlieren tomography where + + align:start position:0% +sigograph on schlieren tomography where + + + align:start position:0% +sigograph on schlieren tomography where +they they do manage to do that with + + align:start position:0% +they they do manage to do that with + + + align:start position:0% +they they do manage to do that with +certain assumptions but anyways + + align:start position:0% +certain assumptions but anyways + + + align:start position:0% +certain assumptions but anyways +if we if we loosen this to allow + + align:start position:0% +if we if we loosen this to allow + + + align:start position:0% +if we if we loosen this to allow +refraction then the algorithm changes + + align:start position:0% +refraction then the algorithm changes + + + align:start position:0% +refraction then the algorithm changes +and says this is very clever work again + + align:start position:0% +and says this is very clever work again + + + align:start position:0% +and says this is very clever work again +this is in slandering hack if you're + + align:start position:0% +this is in slandering hack if you're + + + align:start position:0% +this is in slandering hack if you're +interested but the idea is let's + + align:start position:0% +interested but the idea is let's + + + align:start position:0% +interested but the idea is let's +illuminate the object let's make a + + align:start position:0% +illuminate the object let's make a + + + align:start position:0% +illuminate the object let's make a +parallel beam set up again so we'll + + align:start position:0% +parallel beam set up again so we'll + + + align:start position:0% +parallel beam set up again so we'll +start with some monochromatic plane wave + + align:start position:0% +start with some monochromatic plane wave + + + align:start position:0% +start with some monochromatic plane wave +so we have some laser that's generating + + align:start position:0% +so we have some laser that's generating + + + align:start position:0% +so we have some laser that's generating +one wavelength of light it's it's + + align:start position:0% +one wavelength of light it's it's + + + align:start position:0% +one wavelength of light it's it's +coherent traveling towards our object + + align:start position:0% +coherent traveling towards our object + + + align:start position:0% +coherent traveling towards our object +and it arrives on some detector and so + + align:start position:0% +and it arrives on some detector and so + + + align:start position:0% +and it arrives on some detector and so +we get our projection again again this + + align:start position:0% +we get our projection again again this + + + align:start position:0% +we get our projection again again this +what we're trying to reconstruct now is + + align:start position:0% +what we're trying to reconstruct now is + + + align:start position:0% +what we're trying to reconstruct now is +the index of refraction not the + + align:start position:0% +the index of refraction not the + + + align:start position:0% +the index of refraction not the +absorption okay + + align:start position:0% +absorption okay + + + align:start position:0% +absorption okay +so we receive the scattered wave and it + + align:start position:0% +so we receive the scattered wave and it + + + align:start position:0% +so we receive the scattered wave and it +turns out you also need to measure the + + align:start position:0% +turns out you also need to measure the + + + align:start position:0% +turns out you also need to measure the +phase so you'll have a second reference + + align:start position:0% +phase so you'll have a second reference + + + align:start position:0% +phase so you'll have a second reference +beam so essentially taking a hologram of + + align:start position:0% +beam so essentially taking a hologram of + + + align:start position:0% +beam so essentially taking a hologram of +the object for those of you familiar but + + align:start position:0% +the object for those of you familiar but + + + align:start position:0% +the object for those of you familiar but +you can sort of ignore that basically + + align:start position:0% +you can sort of ignore that basically + + + align:start position:0% +you can sort of ignore that basically +you have a plane wave + + align:start position:0% +you have a plane wave + + + align:start position:0% +you have a plane wave +projecting through the object creating + + align:start position:0% +projecting through the object creating + + + align:start position:0% +projecting through the object creating +some scattered field and so if you run + + align:start position:0% +some scattered field and so if you run + + + align:start position:0% +some scattered field and so if you run +through the math you get a new result + + align:start position:0% +through the math you get a new result + + + align:start position:0% +through the math you get a new result +which is very interesting the foid + + align:start position:0% +which is very interesting the foid + + + align:start position:0% +which is very interesting the foid +projection size theorem changes + + align:start position:0% +projection size theorem changes + + + align:start position:0% +projection size theorem changes +it turns out in your frequency domain + + align:start position:0% +it turns out in your frequency domain + + + align:start position:0% +it turns out in your frequency domain +again we take the 2d fourier transform + + align:start position:0% +again we take the 2d fourier transform + + + align:start position:0% +again we take the 2d fourier transform +or index refraction + + align:start position:0% +or index refraction + + + align:start position:0% +or index refraction +and in the transform domain + + align:start position:0% +and in the transform domain + + + align:start position:0% +and in the transform domain +a plane projection a parallel beam + + align:start position:0% +a plane projection a parallel beam + + + align:start position:0% +a plane projection a parallel beam +projection maps to a curve + + align:start position:0% +projection maps to a curve + + + align:start position:0% +projection maps to a curve +an arc in the frequency domain + + align:start position:0% +an arc in the frequency domain + + + align:start position:0% +an arc in the frequency domain +right so now to do tomography we could + + align:start position:0% +right so now to do tomography we could + + + align:start position:0% +right so now to do tomography we could +do what we did before we could rotate + + align:start position:0% +do what we did before we could rotate + + + align:start position:0% +do what we did before we could rotate +the source or the emitter and detector + + align:start position:0% +the source or the emitter and detector + + + align:start position:0% +the source or the emitter and detector +around the object + + align:start position:0% +around the object + + + align:start position:0% +around the object +right and then we just have to know what + + align:start position:0% +right and then we just have to know what + + + align:start position:0% +right and then we just have to know what +this curve trajectory is which is just + + align:start position:0% +this curve trajectory is which is just + + + align:start position:0% +this curve trajectory is which is just +dependent on the wavelength of light + + align:start position:0% +dependent on the wavelength of light + + + align:start position:0% +dependent on the wavelength of light +right and then we'll populate our + + align:start position:0% +right and then we'll populate our + + + align:start position:0% +right and then we'll populate our +accumulator as before inverse transform + + align:start position:0% +accumulator as before inverse transform + + + align:start position:0% +accumulator as before inverse transform +done + + align:start position:0% +done + + + align:start position:0% +done +does that make sense + + align:start position:0% +does that make sense + + + align:start position:0% +does that make sense +hopefully to everyone + + align:start position:0% +hopefully to everyone + + + align:start position:0% +hopefully to everyone +but there's a really clever trick again + + align:start position:0% +but there's a really clever trick again + + + align:start position:0% +but there's a really clever trick again +no moving parts is the usual theme in + + align:start position:0% +no moving parts is the usual theme in + + + align:start position:0% +no moving parts is the usual theme in +these things right to reconstruct + + align:start position:0% +these things right to reconstruct + + + align:start position:0% +these things right to reconstruct +tomographically this object we have to + + align:start position:0% +tomographically this object we have to + + + align:start position:0% +tomographically this object we have to +rotate something to populate this + + align:start position:0% +rotate something to populate this + + + align:start position:0% +rotate something to populate this +accumulator it turns out the clever + + align:start position:0% +accumulator it turns out the clever + + + align:start position:0% +accumulator it turns out the clever +trick here is that this arc is dependent + + align:start position:0% +trick here is that this arc is dependent + + + align:start position:0% +trick here is that this arc is dependent +on the frequency + + align:start position:0% +on the frequency + + + align:start position:0% +on the frequency +of illumination does anyone see without + + align:start position:0% +of illumination does anyone see without + + + align:start position:0% +of illumination does anyone see without +looking at the thing on the right what + + align:start position:0% +looking at the thing on the right what + + + align:start position:0% +looking at the thing on the right what +do you do + + align:start position:0% +do you do + + + align:start position:0% +do you do +change the frequency great + + align:start position:0% +change the frequency great + + + align:start position:0% +change the frequency great +that was a great good insight so + + align:start position:0% +that was a great good insight so + + + align:start position:0% +that was a great good insight so +if you just step through the frequency + + align:start position:0% +if you just step through the frequency + + + align:start position:0% +if you just step through the frequency +slowly + + align:start position:0% +slowly + + + align:start position:0% +slowly +right you'll sort of sweep this out + + align:start position:0% +right you'll sort of sweep this out + + + align:start position:0% +right you'll sort of sweep this out +right and you'll get + + align:start position:0% +right and you'll get + + + align:start position:0% +right and you'll get +at least half of the transform + + align:start position:0% +at least half of the transform + + + align:start position:0% +at least half of the transform +but what if i told you that was a real + + align:start position:0% +but what if i told you that was a real + + + align:start position:0% +but what if i told you that was a real +valued function + + align:start position:0% +valued function + + + align:start position:0% +valued function +can you do you know what the property is + + align:start position:0% + + + + align:start position:0% + +what kind of symmetry + + align:start position:0% + + + + align:start position:0% + +conjugate symmetric right right so we + + align:start position:0% +conjugate symmetric right right so we + + + align:start position:0% +conjugate symmetric right right so we +know that this this function is + + align:start position:0% +know that this this function is + + + align:start position:0% +know that this this function is +conjugate symmetric because it's a real + + align:start position:0% +conjugate symmetric because it's a real + + + align:start position:0% +conjugate symmetric because it's a real +value function so getting only half of + + align:start position:0% +value function so getting only half of + + + align:start position:0% +value function so getting only half of +it's enough so we can replicate it right + + align:start position:0% +it's enough so we can replicate it right + + + align:start position:0% +it's enough so we can replicate it right +so again tomography is basically + + align:start position:0% +so again tomography is basically + + + align:start position:0% +so again tomography is basically +remembering signal processing remember + + align:start position:0% +remembering signal processing remember + + + align:start position:0% +remembering signal processing remember +all those transform pairs + + align:start position:0% +all those transform pairs + + + align:start position:0% +all those transform pairs +you'll have good luck in your final + + align:start position:0% +you'll have good luck in your final + + + align:start position:0% +you'll have good luck in your final +project you've decided to use it and so + + align:start position:0% +project you've decided to use it and so + + + align:start position:0% +project you've decided to use it and so +now + + align:start position:0% +now + + + align:start position:0% +now +we can take a sequence of images where + + align:start position:0% +we can take a sequence of images where + + + align:start position:0% +we can take a sequence of images where +we just vary the frequency parameter + + align:start position:0% +we just vary the frequency parameter + + + align:start position:0% +we just vary the frequency parameter +we'll populate this guy use conjugate + + align:start position:0% +we'll populate this guy use conjugate + + + align:start position:0% +we'll populate this guy use conjugate +symmetric symmetry and inverse transform + + align:start position:0% +symmetric symmetry and inverse transform + + + align:start position:0% +symmetric symmetry and inverse transform +and so then you get a new result which + + align:start position:0% +and so then you get a new result which + + + align:start position:0% +and so then you get a new result which +is almost as fundamental in this field + + align:start position:0% +is almost as fundamental in this field + + + align:start position:0% +is almost as fundamental in this field +as the foil projection slice theorem + + align:start position:0% +as the foil projection slice theorem + + + align:start position:0% +as the foil projection slice theorem +which is that a white light + + align:start position:0% +which is that a white light + + + align:start position:0% +which is that a white light +hologram + + align:start position:0% +hologram + + + align:start position:0% +hologram +so basically can can reconstruct the + + align:start position:0% +so basically can can reconstruct the + + + align:start position:0% +so basically can can reconstruct the +index refraction of an object because + + align:start position:0% +index refraction of an object because + + + align:start position:0% +index refraction of an object because +right we can use superposition again we + + align:start position:0% +right we can use superposition again we + + + align:start position:0% +right we can use superposition again we +can eliminate with multiple frequencies + + align:start position:0% +can eliminate with multiple frequencies + + + align:start position:0% +can eliminate with multiple frequencies +at the same time as long as we can + + align:start position:0% +at the same time as long as we can + + + align:start position:0% +at the same time as long as we can +resolve them then we'll get all the data + + align:start position:0% +resolve them then we'll get all the data + + + align:start position:0% +resolve them then we'll get all the data +at once + + align:start position:0% +at once + + + align:start position:0% +at once +right so you basically have a broadband + + align:start position:0% +right so you basically have a broadband + + + align:start position:0% +right so you basically have a broadband +plane coherent wave traveling through + + align:start position:0% +plane coherent wave traveling through + + + align:start position:0% +plane coherent wave traveling through +the object and from that you + + align:start position:0% +the object and from that you + + + align:start position:0% +the object and from that you +instantaneously get the index refraction + + align:start position:0% +instantaneously get the index refraction + + + align:start position:0% +instantaneously get the index refraction +so the refraction diffraction is + + align:start position:0% +so the refraction diffraction is + + + align:start position:0% +so the refraction diffraction is +refraction and diffraction + + align:start position:0% +refraction and diffraction + + + align:start position:0% +refraction and diffraction +are being used + + align:start position:0% +are being used + + + align:start position:0% +are being used +interchangeably here yes you know what + + align:start position:0% +interchangeably here yes you know what + + + align:start position:0% +interchangeably here yes you know what +why refraction and diffraction yeah i + + align:start position:0% +why refraction and diffraction yeah i + + + align:start position:0% +why refraction and diffraction yeah i +mean you're trying to reconstruct + + align:start position:0% +mean you're trying to reconstruct + + + align:start position:0% +mean you're trying to reconstruct +something in presence of refraction + + align:start position:0% +something in presence of refraction + + + align:start position:0% +something in presence of refraction +right using a diffraction theorem + + align:start position:0% +right using a diffraction theorem + + + align:start position:0% +right using a diffraction theorem +right + + align:start position:0% +right + + + align:start position:0% +right +do you know what's the length what's + + align:start position:0% +do you know what's the length what's + + + align:start position:0% +do you know what's the length what's +yeah what's the reason for that i know i + + align:start position:0% +yeah what's the reason for that i know i + + + align:start position:0% +yeah what's the reason for that i know i +i don't think i understand this at a + + align:start position:0% +i don't think i understand this at a + + + align:start position:0% +i don't think i understand this at a +deep enough level that i mean + + align:start position:0% +deep enough level that i mean + + + align:start position:0% +deep enough level that i mean +fundamentally i just realized why + + align:start position:0% +fundamentally i just realized why + + + align:start position:0% +fundamentally i just realized why +confronted confusing the two so + + align:start position:0% +confronted confusing the two so + + + align:start position:0% +confronted confusing the two so +yeah i think + + align:start position:0% +yeah i think + + + align:start position:0% +yeah i think +yeah i have to get back to that okay + + align:start position:0% +yeah i have to get back to that okay + + + align:start position:0% +yeah i have to get back to that okay +it's in slam loop but + + align:start position:0% +it's in slam loop but + + + align:start position:0% +it's in slam loop but +this is getting beyond my + + align:start position:0% +this is getting beyond my + + + align:start position:0% +this is getting beyond my +my not so this is what a reconstruction + + align:start position:0% +my not so this is what a reconstruction + + + align:start position:0% +my not so this is what a reconstruction +looks like of a simulated object right + + align:start position:0% +looks like of a simulated object right + + + align:start position:0% +looks like of a simulated object right +so now our artifacts have this arc + + align:start position:0% +so now our artifacts have this arc + + + align:start position:0% +so now our artifacts have this arc +trajectory + + align:start position:0% +trajectory + + + align:start position:0% +trajectory +but again what this is interesting is if + + align:start position:0% +but again what this is interesting is if + + + align:start position:0% +but again what this is interesting is if +you look at schlieren tomography paper + + align:start position:0% +you look at schlieren tomography paper + + + align:start position:0% +you look at schlieren tomography paper +it means you could get real-time + + align:start position:0% +it means you could get real-time + + + align:start position:0% +it means you could get real-time +reconstruction without strobing any + + align:start position:0% +reconstruction without strobing any + + + align:start position:0% +reconstruction without strobing any +lights by just doing a mono by doing + + align:start position:0% +lights by just doing a mono by doing + + + align:start position:0% +lights by just doing a mono by doing +broadband hologram holographic imaging + + align:start position:0% +broadband hologram holographic imaging + + + align:start position:0% +broadband hologram holographic imaging +of your object and then this is why i + + align:start position:0% +of your object and then this is why i + + + align:start position:0% +of your object and then this is why i +mentioned the filtered back projection + + align:start position:0% +mentioned the filtered back projection + + + align:start position:0% +mentioned the filtered back projection +earlier that was the frequency domain + + align:start position:0% +earlier that was the frequency domain + + + align:start position:0% +earlier that was the frequency domain +reconstruction transform so it turns out + + align:start position:0% +reconstruction transform so it turns out + + + align:start position:0% +reconstruction transform so it turns out +there's a purely spatial domain + + align:start position:0% +there's a purely spatial domain + + + align:start position:0% +there's a purely spatial domain +transform for this one as well and so + + align:start position:0% +transform for this one as well and so + + + align:start position:0% +transform for this one as well and so +this one i don't know but the + + align:start position:0% +this one i don't know but the + + + align:start position:0% +this one i don't know but the +2d fourier transform of an arc + + align:start position:0% +2d fourier transform of an arc + + + align:start position:0% +2d fourier transform of an arc +right maps to this strange depth + + align:start position:0% +right maps to this strange depth + + + align:start position:0% +right maps to this strange depth +dependent function you see here + + align:start position:0% +dependent function you see here + + + align:start position:0% +dependent function you see here +right + + align:start position:0% +right + + + align:start position:0% +right +so that's what filter back projection + + align:start position:0% +so that's what filter back projection + + + align:start position:0% +so that's what filter back projection +becomes is smearing but along + + align:start position:0% +becomes is smearing but along + + + align:start position:0% +becomes is smearing but along +these paths that become wider as you go + + align:start position:0% +these paths that become wider as you go + + + align:start position:0% +these paths that become wider as you go +in depth + + align:start position:0% +in depth + + + align:start position:0% +in depth +right just because that's what the + + align:start position:0% +right just because that's what the + + + align:start position:0% +right just because that's what the +inverse right transform is of + + align:start position:0% +inverse right transform is of + + + align:start position:0% +inverse right transform is of +this arc pattern so you can do filtered + + align:start position:0% +this arc pattern so you can do filtered + + + align:start position:0% +this arc pattern so you can do filtered +back projection but it turns out it's + + align:start position:0% +back projection but it turns out it's + + + align:start position:0% +back projection but it turns out it's +much more computationally expensive so + + align:start position:0% +much more computationally expensive so + + + align:start position:0% +much more computationally expensive so +they generally do this using frequency + + align:start position:0% +they generally do this using frequency + + + align:start position:0% +they generally do this using frequency +domain i think + + align:start position:0% +domain i think + + + align:start position:0% +domain i think +and so then now we move so that was + + align:start position:0% +and so then now we move so that was + + + align:start position:0% +and so then now we move so that was +weakly refracting but now if we move to + + align:start position:0% +weakly refracting but now if we move to + + + align:start position:0% +weakly refracting but now if we move to +say like putting putting leds against + + align:start position:0% +say like putting putting leds against + + + align:start position:0% +say like putting putting leds against +your skin right now we're talking about + + align:start position:0% +your skin right now we're talking about + + + align:start position:0% +your skin right now we're talking about +things that are strongly scattered + + align:start position:0% +things that are strongly scattered + + + align:start position:0% +things that are strongly scattered +right so we've moved from complete just + + align:start position:0% +right so we've moved from complete just + + + align:start position:0% +right so we've moved from complete just +absorbing along a ballistic trajectory + + align:start position:0% +absorbing along a ballistic trajectory + + + align:start position:0% +absorbing along a ballistic trajectory +towards refracting a little bit and now + + align:start position:0% +towards refracting a little bit and now + + + align:start position:0% +towards refracting a little bit and now +we're just scattering completely imagine + + align:start position:0% +we're just scattering completely imagine + + + align:start position:0% +we're just scattering completely imagine +putting an led on your finger and you + + align:start position:0% +putting an led on your finger and you + + + align:start position:0% +putting an led on your finger and you +want to see the bone inside your finger + + align:start position:0% +want to see the bone inside your finger + + + align:start position:0% +want to see the bone inside your finger +right with just visible light so this is + + align:start position:0% +right with just visible light so this is + + + align:start position:0% +right with just visible light so this is +an example you can see like this is sort + + align:start position:0% +an example you can see like this is sort + + + align:start position:0% +an example you can see like this is sort +of like this is this is a cross section + + align:start position:0% +of like this is this is a cross section + + + align:start position:0% +of like this is this is a cross section +through our finger we'll say and we have + + align:start position:0% +through our finger we'll say and we have + + + align:start position:0% +through our finger we'll say and we have +photo diodes all around + + align:start position:0% +photo diodes all around + + + align:start position:0% +photo diodes all around +our finger and then we put this little + + align:start position:0% +our finger and then we put this little + + + align:start position:0% +our finger and then we put this little +like fiber optic + + align:start position:0% +like fiber optic + + + align:start position:0% +like fiber optic +right against our finger and illuminate + + align:start position:0% +right against our finger and illuminate + + + align:start position:0% +right against our finger and illuminate +it and so you'll sort of scatter light + + align:start position:0% +it and so you'll sort of scatter light + + + align:start position:0% +it and so you'll sort of scatter light +all through that volume and you'll + + align:start position:0% +all through that volume and you'll + + + align:start position:0% +all through that volume and you'll +measure its intensity at some points + + align:start position:0% +measure its intensity at some points + + + align:start position:0% +measure its intensity at some points +coming out on the surface right so this + + align:start position:0% +coming out on the surface right so this + + + align:start position:0% +coming out on the surface right so this +is known as diffuse optical tomography + + align:start position:0% +is known as diffuse optical tomography + + + align:start position:0% +is known as diffuse optical tomography +because diffusion is the key process + + align:start position:0% +because diffusion is the key process + + + align:start position:0% +because diffusion is the key process +we're trying to invert + + align:start position:0% +we're trying to invert + + + align:start position:0% +we're trying to invert +and so + + align:start position:0% +and so + + + align:start position:0% +and so +in all of these cases we're just + + align:start position:0% +in all of these cases we're just + + + align:start position:0% +in all of these cases we're just +creating this inverse system right we're + + align:start position:0% +creating this inverse system right we're + + + align:start position:0% +creating this inverse system right we're +creating something that we then apply + + align:start position:0% +creating something that we then apply + + + align:start position:0% +creating something that we then apply +the inverse square transform to invert + + align:start position:0% +the inverse square transform to invert + + + align:start position:0% +the inverse square transform to invert +or what have you so in strongly + + align:start position:0% +or what have you so in strongly + + + align:start position:0% +or what have you so in strongly +refractive or scattering media you end + + align:start position:0% +refractive or scattering media you end + + + align:start position:0% +refractive or scattering media you end +up with a very difficult model to infer + + align:start position:0% +up with a very difficult model to infer + + + align:start position:0% +up with a very difficult model to infer +it's still posed + + align:start position:0% +it's still posed + + + align:start position:0% +it's still posed +but it's ill-posed and non-linear which + + align:start position:0% +but it's ill-posed and non-linear which + + + align:start position:0% +but it's ill-posed and non-linear which +means it's very hard + + align:start position:0% +means it's very hard + + + align:start position:0% +means it's very hard +so what they generally do is they they + + align:start position:0% +so what they generally do is they they + + + align:start position:0% +so what they generally do is they they +use some tricks to get to sort of + + align:start position:0% +use some tricks to get to sort of + + + align:start position:0% +use some tricks to get to sort of +bootstrap the inversion right so if you + + align:start position:0% +bootstrap the inversion right so if you + + + align:start position:0% +bootstrap the inversion right so if you +can start with a good initial guess + + align:start position:0% +can start with a good initial guess + + + align:start position:0% +can start with a good initial guess +of say what the here we're looking maybe + + align:start position:0% +of say what the here we're looking maybe + + + align:start position:0% +of say what the here we're looking maybe +for optical density right we're looking + + align:start position:0% +for optical density right we're looking + + + align:start position:0% +for optical density right we're looking +at how dense the material is that's the + + align:start position:0% +at how dense the material is that's the + + + align:start position:0% +at how dense the material is that's the +2d function we're trying to reconstruct + + align:start position:0% +2d function we're trying to reconstruct + + + align:start position:0% +2d function we're trying to reconstruct +in a cross section + + align:start position:0% +in a cross section + + + align:start position:0% +in a cross section +and if we had a good initial guess for + + align:start position:0% +and if we had a good initial guess for + + + align:start position:0% +and if we had a good initial guess for +that + + align:start position:0% +that + + + align:start position:0% +that +then we could sort of use a forward + + align:start position:0% +then we could sort of use a forward + + + align:start position:0% +then we could sort of use a forward +modeling process where we sort of + + align:start position:0% +modeling process where we sort of + + + align:start position:0% +modeling process where we sort of +perturb that density function and see + + align:start position:0% +perturb that density function and see + + + align:start position:0% +perturb that density function and see +how well it predicts the values we found + + align:start position:0% +how well it predicts the values we found + + + align:start position:0% +how well it predicts the values we found +right and we sort of put that in an + + align:start position:0% +right and we sort of put that in an + + + align:start position:0% +right and we sort of put that in an +optimization framework so we do some + + align:start position:0% +optimization framework so we do some + + + align:start position:0% +optimization framework so we do some +gradient descent and we optimize our + + align:start position:0% +gradient descent and we optimize our + + + align:start position:0% +gradient descent and we optimize our +reconstruction the density function so + + align:start position:0% +reconstruction the density function so + + + align:start position:0% +reconstruction the density function so +that the observations match + + align:start position:0% +that the observations match + + + align:start position:0% +that the observations match +the predicted ops predictions match the + + align:start position:0% +the predicted ops predictions match the + + + align:start position:0% +the predicted ops predictions match the +observations right that's the general + + align:start position:0% +observations right that's the general + + + align:start position:0% +observations right that's the general +sort of inversion framework you have + + align:start position:0% +sort of inversion framework you have + + + align:start position:0% +sort of inversion framework you have +right some sort of non-linear gradient + + align:start position:0% +right some sort of non-linear gradient + + + align:start position:0% +right some sort of non-linear gradient +percent algorithm but the question is + + align:start position:0% +percent algorithm but the question is + + + align:start position:0% +percent algorithm but the question is +how do you get that initial guess + + align:start position:0% +how do you get that initial guess + + + align:start position:0% +how do you get that initial guess +of the density function and so you can + + align:start position:0% +of the density function and so you can + + + align:start position:0% +of the density function and so you can +see it says it right there + + align:start position:0% +see it says it right there + + + align:start position:0% +see it says it right there +you can use some other process that is + + align:start position:0% +you can use some other process that is + + + align:start position:0% +you can use some other process that is +ballistic and so that's correlated with + + align:start position:0% +ballistic and so that's correlated with + + + align:start position:0% +ballistic and so that's correlated with +your with your density function so what + + align:start position:0% +your with your density function so what + + + align:start position:0% +your with your density function so what +they generally do here is they use time + + align:start position:0% +they generally do here is they use time + + + align:start position:0% +they generally do here is they use time +of flight they strobe this record the + + align:start position:0% +of flight they strobe this record the + + + align:start position:0% +of flight they strobe this record the +time it takes to travel through + + align:start position:0% +time it takes to travel through + + + align:start position:0% +time it takes to travel through +it maybe not in this specific example + + align:start position:0% +it maybe not in this specific example + + + align:start position:0% +it maybe not in this specific example +but you can imagine doing this you turn + + align:start position:0% +but you can imagine doing this you turn + + + align:start position:0% +but you can imagine doing this you turn +the light on very quickly and look at + + align:start position:0% +the light on very quickly and look at + + + align:start position:0% +the light on very quickly and look at +the time delay and that will give you an + + align:start position:0% +the time delay and that will give you an + + + align:start position:0% +the time delay and that will give you an +initial rough estimate of your density + + align:start position:0% +initial rough estimate of your density + + + align:start position:0% +initial rough estimate of your density +function so that's generally borehole + + align:start position:0% +function so that's generally borehole + + + align:start position:0% +function so that's generally borehole +tomography also does this it uses time + + align:start position:0% +tomography also does this it uses time + + + align:start position:0% +tomography also does this it uses time +of flight to invert the process but also + + align:start position:0% +of flight to invert the process but also + + + align:start position:0% +of flight to invert the process but also +to get the initial guess + + align:start position:0% +to get the initial guess + + + align:start position:0% +to get the initial guess +and then this is used + + align:start position:0% +and then this is used + + + align:start position:0% +and then this is used +a lot in non-invasive medical imaging so + + align:start position:0% +a lot in non-invasive medical imaging so + + + align:start position:0% +a lot in non-invasive medical imaging so +if you don't want to do a ct scan + + align:start position:0% +if you don't want to do a ct scan + + + align:start position:0% +if you don't want to do a ct scan +because the patient's had too much + + align:start position:0% +because the patient's had too much + + + align:start position:0% +because the patient's had too much +dosage of x-rays + + align:start position:0% +dosage of x-rays + + + align:start position:0% +dosage of x-rays +you can for instance put electrodes + + align:start position:0% +you can for instance put electrodes + + + align:start position:0% +you can for instance put electrodes +on their body like you see here and at + + align:start position:0% +on their body like you see here and at + + + align:start position:0% +on their body like you see here and at +least get a rough something not as high + + align:start position:0% +least get a rough something not as high + + + align:start position:0% +least get a rough something not as high +quality as a ct scan but sufficient to + + align:start position:0% +quality as a ct scan but sufficient to + + + align:start position:0% +quality as a ct scan but sufficient to +make the diagnosis so here's an example + + align:start position:0% +make the diagnosis so here's an example + + + align:start position:0% +make the diagnosis so here's an example +of sort of how you apply diffuse optical + + align:start position:0% +of sort of how you apply diffuse optical + + + align:start position:0% +of sort of how you apply diffuse optical +tomography for diagnostic purposes so + + align:start position:0% +tomography for diagnostic purposes so + + + align:start position:0% +tomography for diagnostic purposes so +here we have two twins two babies + + align:start position:0% +here we have two twins two babies + + + align:start position:0% +here we have two twins two babies +left one versus the right one again the + + align:start position:0% +left one versus the right one again the + + + align:start position:0% +left one versus the right one again the +twins and then one of them uh had a + + align:start position:0% +twins and then one of them uh had a + + + align:start position:0% +twins and then one of them uh had a +says the specific thing left ventricular + + align:start position:0% +says the specific thing left ventricular + + + align:start position:0% +says the specific thing left ventricular +hemorrhage so they have blood vessel + + align:start position:0% +hemorrhage so they have blood vessel + + + align:start position:0% +hemorrhage so they have blood vessel +rupture on the left hemisphere and you + + align:start position:0% +rupture on the left hemisphere and you + + + align:start position:0% +rupture on the left hemisphere and you +can sort of see here you know so they + + align:start position:0% +can sort of see here you know so they + + + align:start position:0% +can sort of see here you know so they +attach all these electrodes + + align:start position:0% +attach all these electrodes + + + align:start position:0% +attach all these electrodes +and they generate these time of flight + + align:start position:0% +and they generate these time of flight + + + align:start position:0% +and they generate these time of flight +images + + align:start position:0% +images + + + align:start position:0% +images +for the initial gas and then i look at + + align:start position:0% +for the initial gas and then i look at + + + align:start position:0% +for the initial gas and then i look at +the absorption the conductivity and they + + align:start position:0% +the absorption the conductivity and they + + + align:start position:0% +the absorption the conductivity and they +reconstruct this density function which + + align:start position:0% +reconstruct this density function which + + + align:start position:0% +reconstruct this density function which +actually they get two density functions + + align:start position:0% +actually they get two density functions + + + align:start position:0% +actually they get two density functions +one is blood volume and oxygen + + align:start position:0% +one is blood volume and oxygen + + + align:start position:0% +one is blood volume and oxygen +saturation and so here you can clearly + + align:start position:0% +saturation and so here you can clearly + + + align:start position:0% +saturation and so here you can clearly +see the hemorrhage because this is the + + align:start position:0% +see the hemorrhage because this is the + + + align:start position:0% +see the hemorrhage because this is the +this is the twin that has the hemorrhage + + align:start position:0% +this is the twin that has the hemorrhage + + + align:start position:0% +this is the twin that has the hemorrhage +this is the one that doesn't you can see + + align:start position:0% +this is the one that doesn't you can see + + + align:start position:0% +this is the one that doesn't you can see +there's a lot of blood volume that's a + + align:start position:0% +there's a lot of blood volume that's a + + + align:start position:0% +there's a lot of blood volume that's a +good indication of a hemorrhage but not + + align:start position:0% +good indication of a hemorrhage but not + + + align:start position:0% +good indication of a hemorrhage but not +a great one because your prefrontal + + align:start position:0% +a great one because your prefrontal + + + align:start position:0% +a great one because your prefrontal +cortex has a lot of leveling to begin + + align:start position:0% +cortex has a lot of leveling to begin + + + align:start position:0% +cortex has a lot of leveling to begin +with but then also you can see low + + align:start position:0% +with but then also you can see low + + + align:start position:0% +with but then also you can see low +oxygenation right + + align:start position:0% +oxygenation right + + + align:start position:0% +oxygenation right +which tells you that that blood hasn't + + align:start position:0% +which tells you that that blood hasn't + + + align:start position:0% +which tells you that that blood hasn't +been refreshed in a while so it's a big + + align:start position:0% +been refreshed in a while so it's a big + + + align:start position:0% +been refreshed in a while so it's a big +big pile of blood that's not oxygenated + + align:start position:0% +big pile of blood that's not oxygenated + + + align:start position:0% +big pile of blood that's not oxygenated +which means hemorrhage + + align:start position:0% +which means hemorrhage + + + align:start position:0% +which means hemorrhage +so this is just an example where a ct + + align:start position:0% +so this is just an example where a ct + + + align:start position:0% +so this is just an example where a ct +scan really wouldn't show this because + + align:start position:0% +scan really wouldn't show this because + + + align:start position:0% +scan really wouldn't show this because +the density would be the same and so by + + align:start position:0% +the density would be the same and so by + + + align:start position:0% +the density would be the same and so by +using the diffuse optic filmography you + + align:start position:0% +using the diffuse optic filmography you + + + align:start position:0% +using the diffuse optic filmography you +can get a good reconstruction but + + align:start position:0% +can get a good reconstruction but + + + align:start position:0% +can get a good reconstruction but +because it's diffuse you're only going + + align:start position:0% +because it's diffuse you're only going + + + align:start position:0% +because it's diffuse you're only going +to get a low frequency detail + + align:start position:0% +to get a low frequency detail + + + align:start position:0% +to get a low frequency detail +and then here's another example where + + align:start position:0% +and then here's another example where + + + align:start position:0% +and then here's another example where +you can see the non-invasive part is + + align:start position:0% +you can see the non-invasive part is + + + align:start position:0% +you can see the non-invasive part is +starting to be weakened this looks + + align:start position:0% +starting to be weakened this looks + + + align:start position:0% +starting to be weakened this looks +pretty invasive to me because i don't + + align:start position:0% +pretty invasive to me because i don't + + + align:start position:0% +pretty invasive to me because i don't +want to take those electrodes off + + align:start position:0% +want to take those electrodes off + + + align:start position:0% +want to take those electrodes off +so + + align:start position:0% +so + + + align:start position:0% +so +so here you can see this is off + + align:start position:0% +so here you can see this is off + + + align:start position:0% +so here you can see this is off +wikipedia but this is just an example i + + align:start position:0% +wikipedia but this is just an example i + + + align:start position:0% +wikipedia but this is just an example i +found i found it was interesting where + + align:start position:0% +found i found it was interesting where + + + align:start position:0% +found i found it was interesting where +say we want to take ct like images of + + align:start position:0% +say we want to take ct like images of + + + align:start position:0% +say we want to take ct like images of +the heart to study you know + + align:start position:0% +the heart to study you know + + + align:start position:0% +the heart to study you know +some sort of function then we could just + + align:start position:0% +some sort of function then we could just + + + align:start position:0% +some sort of function then we could just +cope the patient electrodes wire them up + + align:start position:0% +cope the patient electrodes wire them up + + + align:start position:0% +cope the patient electrodes wire them up +strobe these electrodes on and off and + + align:start position:0% +strobe these electrodes on and off and + + + align:start position:0% +strobe these electrodes on and off and +the density of functional reconstructing + + align:start position:0% +the density of functional reconstructing + + + align:start position:0% +the density of functional reconstructing +here is conductivity and versus + + align:start position:0% +here is conductivity and versus + + + align:start position:0% +here is conductivity and versus +resistivity which we can then use to + + align:start position:0% +resistivity which we can then use to + + + align:start position:0% +resistivity which we can then use to +look for various problems you know watch + + align:start position:0% +look for various problems you know watch + + + align:start position:0% +look for various problems you know watch +the heartbeat etc + + align:start position:0% +the heartbeat etc + + + align:start position:0% +the heartbeat etc +and so this problem is actually very + + align:start position:0% +and so this problem is actually very + + + align:start position:0% +and so this problem is actually very +difficult it's called the halogerone + + align:start position:0% +difficult it's called the halogerone + + + align:start position:0% +difficult it's called the halogerone +problem and inverting this system + + align:start position:0% +problem and inverting this system + + + align:start position:0% +problem and inverting this system +is very challenging which is why the + + align:start position:0% +is very challenging which is why the + + + align:start position:0% +is very challenging which is why the +images are so low quality + + align:start position:0% +images are so low quality + + + align:start position:0% +images are so low quality +but again you can see this theme is just + + align:start position:0% +but again you can see this theme is just + + + align:start position:0% +but again you can see this theme is just +being extended and extended we're taking + + align:start position:0% +being extended and extended we're taking + + + align:start position:0% +being extended and extended we're taking +tomographic-like projections of the data + + align:start position:0% +tomographic-like projections of the data + + + align:start position:0% +tomographic-like projections of the data +set but our reconstruction equations are + + align:start position:0% +set but our reconstruction equations are + + + align:start position:0% +set but our reconstruction equations are +not just inverse fourier transform + + align:start position:0% +not just inverse fourier transform + + + align:start position:0% +not just inverse fourier transform +because of the scatter right + + align:start position:0% +because of the scatter right + + + align:start position:0% +because of the scatter right +and so then you might think about well + + align:start position:0% +and so then you might think about well + + + align:start position:0% +and so then you might think about well +if we're now going to make the + + align:start position:0% +if we're now going to make the + + + align:start position:0% +if we're now going to make the +competition photography product project + + align:start position:0% +competition photography product project + + + align:start position:0% +competition photography product project +out of this what if i have scatter + + align:start position:0% +out of this what if i have scatter + + + align:start position:0% +out of this what if i have scatter +scattered light and a light field + + align:start position:0% +scattered light and a light field + + + align:start position:0% +scattered light and a light field +photograph then i end up with this + + align:start position:0% +photograph then i end up with this + + + align:start position:0% +photograph then i end up with this +problem right so there's there's your + + align:start position:0% +problem right so there's there's your + + + align:start position:0% +problem right so there's there's your +final project a plus b equals project + + align:start position:0% +final project a plus b equals project + + + align:start position:0% +final project a plus b equals project +okay so + + align:start position:0% +okay so + + + align:start position:0% +okay so +now sort of moving we're almost through + + align:start position:0% +now sort of moving we're almost through + + + align:start position:0% +now sort of moving we're almost through +the talk now but uh we'll take so a lot + + align:start position:0% +the talk now but uh we'll take so a lot + + + align:start position:0% +the talk now but uh we'll take so a lot +of this was on tomography + + align:start position:0% +of this was on tomography + + + align:start position:0% +of this was on tomography +but the general idea of getting a + + align:start position:0% +but the general idea of getting a + + + align:start position:0% +but the general idea of getting a +cross-sectional image reappears + + align:start position:0% +cross-sectional image reappears + + + align:start position:0% +cross-sectional image reappears +throughout the sciences and so in + + align:start position:0% +throughout the sciences and so in + + + align:start position:0% +throughout the sciences and so in +biology + + align:start position:0% +biology + + + align:start position:0% +biology +uh rather than using x-rays they do this + + align:start position:0% +uh rather than using x-rays they do this + + + align:start position:0% +uh rather than using x-rays they do this +optically and they just use 3d + + align:start position:0% +optically and they just use 3d + + + align:start position:0% +optically and they just use 3d +convolution so it's a very simple idea + + align:start position:0% +convolution so it's a very simple idea + + + align:start position:0% +convolution so it's a very simple idea +probably all of you understand it + + align:start position:0% +probably all of you understand it + + + align:start position:0% +probably all of you understand it +already + + align:start position:0% +already + + + align:start position:0% +already +but the idea is say i have some specimen + + align:start position:0% +but the idea is say i have some specimen + + + align:start position:0% +but the idea is say i have some specimen +in a microscope that has some some depth + + align:start position:0% +in a microscope that has some some depth + + + align:start position:0% +in a microscope that has some some depth +to it and i want to reconstruct it in 3d + + align:start position:0% +to it and i want to reconstruct it in 3d + + + align:start position:0% +to it and i want to reconstruct it in 3d +so how do i do that well the simple + + align:start position:0% +so how do i do that well the simple + + + align:start position:0% +so how do i do that well the simple +observation is to model the image + + align:start position:0% +observation is to model the image + + + align:start position:0% +observation is to model the image +formation process + + align:start position:0% +formation process + + + align:start position:0% +formation process +so what if i just had a single beam in + + align:start position:0% +so what if i just had a single beam in + + + align:start position:0% +so what if i just had a single beam in +space + + align:start position:0% +space + + + align:start position:0% +space +and i focused on it then i sort of see + + align:start position:0% +and i focused on it then i sort of see + + + align:start position:0% +and i focused on it then i sort of see +this image that would be like the + + align:start position:0% +this image that would be like the + + + align:start position:0% +this image that would be like the +impulse response function for focusing + + align:start position:0% +impulse response function for focusing + + + align:start position:0% +impulse response function for focusing +on this plane + + align:start position:0% +on this plane + + + align:start position:0% +on this plane +and then if i focus slightly below our + + align:start position:0% +and then if i focus slightly below our + + + align:start position:0% +and then if i focus slightly below our +point source i'll see a defocus sort of + + align:start position:0% +point source i'll see a defocus sort of + + + align:start position:0% +point source i'll see a defocus sort of +blur as i defocus more and more i see a + + align:start position:0% +blur as i defocus more and more i see a + + + align:start position:0% +blur as i defocus more and more i see a +larger blur + + align:start position:0% +larger blur + + + align:start position:0% +larger blur +right so this is known as a focal stack + + align:start position:0% +right so this is known as a focal stack + + + align:start position:0% +right so this is known as a focal stack +right i take my microscope i just + + align:start position:0% +right i take my microscope i just + + + align:start position:0% +right i take my microscope i just +translate the specimen slide without + + align:start position:0% +translate the specimen slide without + + + align:start position:0% +translate the specimen slide without +changing the optics any and i create a + + align:start position:0% +changing the optics any and i create a + + + align:start position:0% +changing the optics any and i create a +focal step this three dimensional + + align:start position:0% +focal step this three dimensional + + + align:start position:0% +focal step this three dimensional +impulse response to a point source right + + align:start position:0% +impulse response to a point source right + + + align:start position:0% +impulse response to a point source right +so if i look at this as a function of + + align:start position:0% +so if i look at this as a function of + + + align:start position:0% +so if i look at this as a function of +depth if i just take say this slice + + align:start position:0% +depth if i just take say this slice + + + align:start position:0% +depth if i just take say this slice +through the + + align:start position:0% +through the + + + align:start position:0% +through the +point spread function and then i look as + + align:start position:0% +point spread function and then i look as + + + align:start position:0% +point spread function and then i look as +a function of depth into the object i + + align:start position:0% +a function of depth into the object i + + + align:start position:0% +a function of depth into the object i +have this three-dimensional blur where + + align:start position:0% +have this three-dimensional blur where + + + align:start position:0% +have this three-dimensional blur where +you can see it sort of goes out with + + align:start position:0% +you can see it sort of goes out with + + + align:start position:0% +you can see it sort of goes out with +these two inverted cones + + align:start position:0% +these two inverted cones + + + align:start position:0% +these two inverted cones +right + + align:start position:0% +right + + + align:start position:0% +right +and so now to model + + align:start position:0% +and so now to model + + + align:start position:0% +and so now to model +right now we can model + + align:start position:0% +right now we can model + + + align:start position:0% +right now we can model +the image formation process if you + + align:start position:0% +the image formation process if you + + + align:start position:0% +the image formation process if you +assume that the specimen you're + + align:start position:0% +assume that the specimen you're + + + align:start position:0% +assume that the specimen you're +observing does not scatter significantly + + align:start position:0% +observing does not scatter significantly + + + align:start position:0% +observing does not scatter significantly +then you can use a linear image + + align:start position:0% +then you can use a linear image + + + align:start position:0% +then you can use a linear image +formation model which is very simple + + align:start position:0% +formation model which is very simple + + + align:start position:0% +formation model which is very simple +you have some three-dimensional + + align:start position:0% +you have some three-dimensional + + + align:start position:0% +you have some three-dimensional +source function which is just + + align:start position:0% +source function which is just + + + align:start position:0% +source function which is just +decomposing your object into a series of + + align:start position:0% +decomposing your object into a series of + + + align:start position:0% +decomposing your object into a series of +point sources + + align:start position:0% +point sources + + + align:start position:0% +point sources +each point source generates a psf + + align:start position:0% +each point source generates a psf + + + align:start position:0% +each point source generates a psf +weighted by whatever the intensity of + + align:start position:0% +weighted by whatever the intensity of + + + align:start position:0% +weighted by whatever the intensity of +that point is that generates the focal + + align:start position:0% +that point is that generates the focal + + + align:start position:0% +that point is that generates the focal +stack i see that make sense to everyone + + align:start position:0% +stack i see that make sense to everyone + + + align:start position:0% +stack i see that make sense to everyone +and again this is only true + + align:start position:0% +and again this is only true + + + align:start position:0% +and again this is only true +under the assumption that scattering is + + align:start position:0% +under the assumption that scattering is + + + align:start position:0% +under the assumption that scattering is +not significant or else this this model + + align:start position:0% +not significant or else this this model + + + align:start position:0% +not significant or else this this model +is not not correct + + align:start position:0% +is not not correct + + + align:start position:0% +is not not correct +so generally what we're doing is we're + + align:start position:0% +so generally what we're doing is we're + + + align:start position:0% +so generally what we're doing is we're +taking a three-dimensional function + + align:start position:0% +taking a three-dimensional function + + + align:start position:0% +taking a three-dimensional function +convolving with another + + align:start position:0% +convolving with another + + + align:start position:0% +convolving with another +three-dimensional function and again you + + align:start position:0% +three-dimensional function and again you + + + align:start position:0% +three-dimensional function and again you +always use the same trick in medical + + align:start position:0% +always use the same trick in medical + + + align:start position:0% +always use the same trick in medical +imaging first thing you do is take the + + align:start position:0% +imaging first thing you do is take the + + + align:start position:0% +imaging first thing you do is take the +fourier transform so if we take the 3d + + align:start position:0% +fourier transform so if we take the 3d + + + align:start position:0% +fourier transform so if we take the 3d +fourier transform of this then everyone + + align:start position:0% +fourier transform of this then everyone + + + align:start position:0% +fourier transform of this then everyone +knows the convolution theorem to + + align:start position:0% +knows the convolution theorem to + + + align:start position:0% +knows the convolution theorem to +simulate this in the frequency domain we + + align:start position:0% +simulate this in the frequency domain we + + + align:start position:0% +simulate this in the frequency domain we +take the 3d40 transform the object 3d4 + + align:start position:0% +take the 3d40 transform the object 3d4 + + + align:start position:0% +take the 3d40 transform the object 3d4 +transform the psf + + align:start position:0% +transform the psf + + + align:start position:0% +transform the psf +multiply the two and that gives us the + + align:start position:0% +multiply the two and that gives us the + + + align:start position:0% +multiply the two and that gives us the +first transform of the focal step + + align:start position:0% +first transform of the focal step + + + align:start position:0% +first transform of the focal step +it won't follow + + align:start position:0% +it won't follow + + + align:start position:0% +it won't follow +okay so now if i want to get rid of the + + align:start position:0% +okay so now if i want to get rid of the + + + align:start position:0% +okay so now if i want to get rid of the +blur because remember we talked about + + align:start position:0% +blur because remember we talked about + + + align:start position:0% +blur because remember we talked about +laminography + + align:start position:0% +laminography + + + align:start position:0% +laminography +things out of the plane will be blurred + + align:start position:0% +things out of the plane will be blurred + + + align:start position:0% +things out of the plane will be blurred +right so i want to take a photograph + + align:start position:0% +right so i want to take a photograph + + + align:start position:0% +right so i want to take a photograph +with a microscope but i want to be like + + align:start position:0% +with a microscope but i want to be like + + + align:start position:0% +with a microscope but i want to be like +a pinhole i want every single thing to + + align:start position:0% +a pinhole i want every single thing to + + + align:start position:0% +a pinhole i want every single thing to +be in focus so i can look at structures + + align:start position:0% +be in focus so i can look at structures + + + align:start position:0% +be in focus so i can look at structures +that have some depth to them right + + align:start position:0% +that have some depth to them right + + + align:start position:0% +that have some depth to them right +but the problem with that is we have the + + align:start position:0% +but the problem with that is we have the + + + align:start position:0% +but the problem with that is we have the +blur and so then we just invert this so + + align:start position:0% +blur and so then we just invert this so + + + align:start position:0% +blur and so then we just invert this so +we take the 3d 40 transform of the focal + + align:start position:0% +we take the 3d 40 transform of the focal + + + align:start position:0% +we take the 3d 40 transform of the focal +stack + + align:start position:0% +stack + + + align:start position:0% +stack +and divide by the three before you + + align:start position:0% +and divide by the three before you + + + align:start position:0% +and divide by the three before you +transform the psf we end up with our + + align:start position:0% +transform the psf we end up with our + + + align:start position:0% +transform the psf we end up with our +object + + align:start position:0% +object + + + align:start position:0% +object +which we then inverse three for our + + align:start position:0% +which we then inverse three for our + + + align:start position:0% +which we then inverse three for our +transform and that gives us the focal + + align:start position:0% +transform and that gives us the focal + + + align:start position:0% +transform and that gives us the focal +stack all in focus + + align:start position:0% +stack all in focus + + + align:start position:0% +stack all in focus +so it probably most of you are you're + + align:start position:0% +so it probably most of you are you're + + + align:start position:0% +so it probably most of you are you're +who's familiar or done decompolation + + align:start position:0% +who's familiar or done decompolation + + + align:start position:0% +who's familiar or done decompolation +before understand it + + align:start position:0% +before understand it + + + align:start position:0% +before understand it +convolution is a new concept to everyone + + align:start position:0% +convolution is a new concept to everyone + + + align:start position:0% +convolution is a new concept to everyone +interesting okay well i probably should + + align:start position:0% +interesting okay well i probably should + + + align:start position:0% +interesting okay well i probably should +have explained this in 2d but hopefully + + align:start position:0% +have explained this in 2d but hopefully + + + align:start position:0% +have explained this in 2d but hopefully +you followed what i was explaining so if + + align:start position:0% +you followed what i was explaining so if + + + align:start position:0% +you followed what i was explaining so if +this was 2d + + align:start position:0% +this was 2d + + + align:start position:0% +this was 2d +right then you can just all these + + align:start position:0% +right then you can just all these + + + align:start position:0% +right then you can just all these +transform become two-dimensional right + + align:start position:0% +transform become two-dimensional right + + + align:start position:0% +transform become two-dimensional right +that's the basic idea but yeah so + + align:start position:0% +that's the basic idea but yeah so + + + align:start position:0% +that's the basic idea but yeah so +deconvolution is it's very similar to + + align:start position:0% +deconvolution is it's very similar to + + + align:start position:0% +deconvolution is it's very similar to +what you did for uh + + align:start position:0% +what you did for uh + + + align:start position:0% +what you did for uh +in the convolution is very similar to + + align:start position:0% +in the convolution is very similar to + + + align:start position:0% +in the convolution is very similar to +what you did for your lightful + + align:start position:0% +what you did for your lightful + + + align:start position:0% +what you did for your lightful +assignment which is + + align:start position:0% +assignment which is + + + align:start position:0% +assignment which is +shift and add shift and add is basically + + align:start position:0% +shift and add shift and add is basically + + + align:start position:0% +shift and add shift and add is basically +convolution + + align:start position:0% +convolution + + + align:start position:0% +convolution +and imagine if you given all those + + align:start position:0% +and imagine if you given all those + + + align:start position:0% +and imagine if you given all those +refocused images you wanted to go back + + align:start position:0% +refocused images you wanted to go back + + + align:start position:0% +refocused images you wanted to go back +and construct the light field + + align:start position:0% +and construct the light field + + + align:start position:0% +and construct the light field +that would be a form of decomposition + + align:start position:0% +that would be a form of decomposition + + + align:start position:0% +that would be a form of decomposition +and instead of doing it in frequency + + align:start position:0% +and instead of doing it in frequency + + + align:start position:0% +and instead of doing it in frequency +domain for the assignment you did it in + + align:start position:0% +domain for the assignment you did it in + + + align:start position:0% +domain for the assignment you did it in +the primal domain you just shifted and + + align:start position:0% +the primal domain you just shifted and + + + align:start position:0% +the primal domain you just shifted and +added the images shifting and adding + + align:start position:0% +added the images shifting and adding + + + align:start position:0% +added the images shifting and adding +in primary domain is same as + + align:start position:0% +in primary domain is same as + + + align:start position:0% +in primary domain is same as +projection or convolution in the sorry + + align:start position:0% +projection or convolution in the sorry + + + align:start position:0% +projection or convolution in the sorry +projection or + + align:start position:0% +projection or + + + align:start position:0% +projection or +convolution basically + + align:start position:0% +convolution basically + + + align:start position:0% +convolution basically +so + + align:start position:0% +so + + + align:start position:0% +so +so hopefully everyone understood that to + + align:start position:0% +so hopefully everyone understood that to + + + align:start position:0% +so hopefully everyone understood that to +de-blur to put everything sharply in + + align:start position:0% +de-blur to put everything sharply in + + + align:start position:0% +de-blur to put everything sharply in +focus + + align:start position:0% +focus + + + align:start position:0% +focus +so if i apply this algorithm to the + + align:start position:0% +so if i apply this algorithm to the + + + align:start position:0% +so if i apply this algorithm to the +impulse response itself what would you + + align:start position:0% +impulse response itself what would you + + + align:start position:0% +impulse response itself what would you +expect to see what would these images + + align:start position:0% +expect to see what would these images + + + align:start position:0% +expect to see what would these images +become + + align:start position:0% +become + + + align:start position:0% +become +maybe that's a check to see if you + + align:start position:0% +maybe that's a check to see if you + + + align:start position:0% +maybe that's a check to see if you +understood this + + align:start position:0% + + + + align:start position:0% + +question all become the point source + + align:start position:0% + + + + align:start position:0% + +so i'm trying to remove the blur if i + + align:start position:0% +so i'm trying to remove the blur if i + + + align:start position:0% +so i'm trying to remove the blur if i +had a point source again these images + + align:start position:0% +had a point source again these images + + + align:start position:0% +had a point source again these images +are at different depths right + + align:start position:0% + + + + align:start position:0% + +so if i apply the decomposition + + align:start position:0% +so if i apply the decomposition + + + align:start position:0% +so if i apply the decomposition +algorithm + + align:start position:0% +algorithm + + + align:start position:0% +algorithm +i expect to see certainly a sharp point + + align:start position:0% +i expect to see certainly a sharp point + + + align:start position:0% +i expect to see certainly a sharp point +right here right + + align:start position:0% +right here right + + + align:start position:0% +right here right +but what about if i move just a little + + align:start position:0% +but what about if i move just a little + + + align:start position:0% +but what about if i move just a little +in depth + + align:start position:0% + + + + align:start position:0% + +remember there's a blur here right yeah + + align:start position:0% +remember there's a blur here right yeah + + + align:start position:0% +remember there's a blur here right yeah +right so + + align:start position:0% +right so + + + align:start position:0% +right so +convolution means blur + + align:start position:0% +convolution means blur + + + align:start position:0% +convolution means blur +and in most of the cases deconvolution + + align:start position:0% +and in most of the cases deconvolution + + + align:start position:0% +and in most of the cases deconvolution +means removing the blur + + align:start position:0% +means removing the blur + + + align:start position:0% +means removing the blur +so you wouldn't see anything now you + + align:start position:0% +so you wouldn't see anything now you + + + align:start position:0% +so you wouldn't see anything now you +should see the other image from this one + + align:start position:0% +should see the other image from this one + + + align:start position:0% +should see the other image from this one +which will you see why wouldn't you see + + align:start position:0% +which will you see why wouldn't you see + + + align:start position:0% +which will you see why wouldn't you see +the + + align:start position:0% + + + + align:start position:0% + +you don't see anything + + align:start position:0% +you don't see anything + + + align:start position:0% +you don't see anything +all right so you get to go start and so + + align:start position:0% +all right so you get to go start and so + + + align:start position:0% +all right so you get to go start and so +that's that so that checks hopefully if + + align:start position:0% +that's that so that checks hopefully if + + + align:start position:0% +that's that so that checks hopefully if +you understand why all these images were + + align:start position:0% +you understand why all these images were + + + align:start position:0% +you understand why all these images were +completely dark except the center rule + + align:start position:0% +completely dark except the center rule + + + align:start position:0% +completely dark except the center rule +right then that's that's decomposition + + align:start position:0% +right then that's that's decomposition + + + align:start position:0% +right then that's that's decomposition +in general so then just to point out + + align:start position:0% +in general so then just to point out + + + align:start position:0% +in general so then just to point out +again + + align:start position:0% +again + + + align:start position:0% +again +when we're doing this inversion we're + + align:start position:0% +when we're doing this inversion we're + + + align:start position:0% +when we're doing this inversion we're +dividing + + align:start position:0% +dividing + + + align:start position:0% +dividing +by the point transform + + align:start position:0% +by the point transform + + + align:start position:0% +by the point transform +of our blur kernel right + + align:start position:0% +of our blur kernel right + + + align:start position:0% +of our blur kernel right +and so the problem here if you remember + + align:start position:0% +and so the problem here if you remember + + + align:start position:0% +and so the problem here if you remember +earlier when we were doing the inverse + + align:start position:0% +earlier when we were doing the inverse + + + align:start position:0% +earlier when we were doing the inverse +square transform the frequency domain + + align:start position:0% +square transform the frequency domain + + + align:start position:0% +square transform the frequency domain +you really don't want zeros right so if + + align:start position:0% +you really don't want zeros right so if + + + align:start position:0% +you really don't want zeros right so if +i divide by a zero i'm going to have + + align:start position:0% +i divide by a zero i'm going to have + + + align:start position:0% +i divide by a zero i'm going to have +problems right but if you look at our + + align:start position:0% +problems right but if you look at our + + + align:start position:0% +problems right but if you look at our +focal stack and look at the + + align:start position:0% +focal stack and look at the + + + align:start position:0% +focal stack and look at the +the blur kernel + + align:start position:0% +the blur kernel + + + align:start position:0% +the blur kernel +we have lots of zeros right + + align:start position:0% +we have lots of zeros right + + + align:start position:0% +we have lots of zeros right +and these zeros actually come in due to + + align:start position:0% +and these zeros actually come in due to + + + align:start position:0% +and these zeros actually come in due to +the numerical aperture the lens right if + + align:start position:0% +the numerical aperture the lens right if + + + align:start position:0% +the numerical aperture the lens right if +the lens sees at a very sharp angle + + align:start position:0% +the lens sees at a very sharp angle + + + align:start position:0% +the lens sees at a very sharp angle +right we can make this have fewer zeros + + align:start position:0% +right we can make this have fewer zeros + + + align:start position:0% +right we can make this have fewer zeros +so anyways since you haven't seen + + align:start position:0% +so anyways since you haven't seen + + + align:start position:0% +so anyways since you haven't seen +convolution before + + align:start position:0% +convolution before + + + align:start position:0% +convolution before +i think that's probably enough just to + + align:start position:0% +i think that's probably enough just to + + + align:start position:0% +i think that's probably enough just to +observe that when you're de-blurring + + align:start position:0% +observe that when you're de-blurring + + + align:start position:0% +observe that when you're de-blurring +you really need this function to not + + align:start position:0% +you really need this function to not + + + align:start position:0% +you really need this function to not +have zeros right so if you apply the + + align:start position:0% +have zeros right so if you apply the + + + align:start position:0% +have zeros right so if you apply the +concepts we saw earlier in the sort of + + align:start position:0% +concepts we saw earlier in the sort of + + + align:start position:0% +concepts we saw earlier in the sort of +computational photography idea the idea + + align:start position:0% +computational photography idea the idea + + + align:start position:0% +computational photography idea the idea +would be somehow to modify the optics at + + align:start position:0% +would be somehow to modify the optics at + + + align:start position:0% +would be somehow to modify the optics at +apertures codes to make this blur kernel + + align:start position:0% +apertures codes to make this blur kernel + + + align:start position:0% +apertures codes to make this blur kernel +not have zeros so when you do the + + align:start position:0% +not have zeros so when you do the + + + align:start position:0% +not have zeros so when you do the +inversion you don't amplify high + + align:start position:0% +inversion you don't amplify high + + + align:start position:0% +inversion you don't amplify high +frequencies other problems so so + + align:start position:0% +frequencies other problems so so + + + align:start position:0% +frequencies other problems so so +if i understand what you're getting + + align:start position:0% +if i understand what you're getting + + + align:start position:0% +if i understand what you're getting +correctly you're taking multiple images + + align:start position:0% +correctly you're taking multiple images + + + align:start position:0% +correctly you're taking multiple images +and different depth yes + + align:start position:0% +and different depth yes + + + align:start position:0% +and different depth yes +so why can't you focus at different + + align:start position:0% +so why can't you focus at different + + + align:start position:0% +so why can't you focus at different +depths why do you that's what we're + + align:start position:0% +depths why do you that's what we're + + + align:start position:0% +depths why do you that's what we're +doing so + + align:start position:0% +doing so + + + align:start position:0% +doing so +then if you are taking multiple images + + align:start position:0% +then if you are taking multiple images + + + align:start position:0% +then if you are taking multiple images +why don't you shift your focal plane to + + align:start position:0% +why don't you shift your focal plane to + + + align:start position:0% +why don't you shift your focal plane to +different depths that's exactly what + + align:start position:0% +different depths that's exactly what + + + align:start position:0% +different depths that's exactly what +we're doing so + + align:start position:0% +we're doing so + + + align:start position:0% +we're doing so +but it's just like laminography from + + align:start position:0% +but it's just like laminography from + + + align:start position:0% +but it's just like laminography from +before everything + + align:start position:0% +before everything + + + align:start position:0% +before everything +it's a thick specimen + + align:start position:0% +it's a thick specimen + + + align:start position:0% +it's a thick specimen +right so let's go to a picture pictures + + align:start position:0% +right so let's go to a picture pictures + + + align:start position:0% +right so let's go to a picture pictures +are always worth a lot more so we have + + align:start position:0% +are always worth a lot more so we have + + + align:start position:0% +are always worth a lot more so we have +this + + align:start position:0% +this + + + align:start position:0% +this +mandible of some insect right we're + + align:start position:0% +mandible of some insect right we're + + + align:start position:0% +mandible of some insect right we're +trying to get a cross-sectional image + + align:start position:0% +trying to get a cross-sectional image + + + align:start position:0% +trying to get a cross-sectional image +right + + align:start position:0% +right + + + align:start position:0% +right +but + + align:start position:0% +but + + + align:start position:0% +but +if we don't do anything if we just focus + + align:start position:0% +if we don't do anything if we just focus + + + align:start position:0% +if we don't do anything if we just focus +at some depth in the specimen it's back + + align:start position:0% +at some depth in the specimen it's back + + + align:start position:0% +at some depth in the specimen it's back +illuminated you get this halo right + + align:start position:0% +illuminated you get this halo right + + + align:start position:0% +illuminated you get this halo right +because everything out of the focal + + align:start position:0% +because everything out of the focal + + + align:start position:0% +because everything out of the focal +plane is blurred yes right yes so now i + + align:start position:0% +plane is blurred yes right yes so now i + + + align:start position:0% +plane is blurred yes right yes so now i +can focus + + align:start position:0% +can focus + + + align:start position:0% +can focus +at another depth and generate a new + + align:start position:0% +at another depth and generate a new + + + align:start position:0% +at another depth and generate a new +image which is exactly what a focal + + align:start position:0% +image which is exactly what a focal + + + align:start position:0% +image which is exactly what a focal +stack is but i'll still have that blur + + align:start position:0% +stack is but i'll still have that blur + + + align:start position:0% +stack is but i'll still have that blur +present + + align:start position:0% +present + + + align:start position:0% +present +so what i'm trying to do is is collect + + align:start position:0% +so what i'm trying to do is is collect + + + align:start position:0% +so what i'm trying to do is is collect +that focal stack and then invert that + + align:start position:0% +that focal stack and then invert that + + + align:start position:0% +that focal stack and then invert that +whole system so i get really what is a + + align:start position:0% +whole system so i get really what is a + + + align:start position:0% +whole system so i get really what is a +cross-sectional image + + align:start position:0% +cross-sectional image + + + align:start position:0% +cross-sectional image +so that nothing + + align:start position:0% +so that nothing + + + align:start position:0% +so that nothing +is blurred in it right which is what + + align:start position:0% +is blurred in it right which is what + + + align:start position:0% +is blurred in it right which is what +laminography does which is what + + align:start position:0% +laminography does which is what + + + align:start position:0% +laminography does which is what +tomography does in general right so you + + align:start position:0% +tomography does in general right so you + + + align:start position:0% +tomography does in general right so you +can see that theme something has to be + + align:start position:0% +can see that theme something has to be + + + align:start position:0% +can see that theme something has to be +done to remove the boiler + + align:start position:0% +done to remove the boiler + + + align:start position:0% +done to remove the boiler +right + + align:start position:0% +right + + + align:start position:0% +right +and so in this case what's done to + + align:start position:0% +and so in this case what's done to + + + align:start position:0% +and so in this case what's done to +remove the blur is that division + + align:start position:0% +remove the blur is that division + + + align:start position:0% +remove the blur is that division +by our impulse response point transform + + align:start position:0% +by our impulse response point transform + + + align:start position:0% +by our impulse response point transform +right so this d blurring algorithm + + align:start position:0% +right so this d blurring algorithm + + + align:start position:0% +right so this d blurring algorithm +right rather than using a tomographic + + align:start position:0% +right rather than using a tomographic + + + align:start position:0% +right rather than using a tomographic +type typography and so + + align:start position:0% +type typography and so + + + align:start position:0% +type typography and so +just to show you the gist so i think if + + align:start position:0% +just to show you the gist so i think if + + + align:start position:0% +just to show you the gist so i think if +since it seems that decomposition is a + + align:start position:0% +since it seems that decomposition is a + + + align:start position:0% +since it seems that decomposition is a +new concept for everyone definitely go + + align:start position:0% +new concept for everyone definitely go + + + align:start position:0% +new concept for everyone definitely go +and read the wiki entry because i think + + align:start position:0% +and read the wiki entry because i think + + + align:start position:0% +and read the wiki entry because i think +that idea has been beaten to death in + + align:start position:0% +that idea has been beaten to death in + + + align:start position:0% +that idea has been beaten to death in +the competition photography field so you + + align:start position:0% +the competition photography field so you + + + align:start position:0% +the competition photography field so you +can definitely get some final projects + + align:start position:0% +can definitely get some final projects + + + align:start position:0% +can definitely get some final projects +out of it + + align:start position:0% +out of it + + + align:start position:0% +out of it +you can see how you can use that so the + + align:start position:0% +you can see how you can use that so the + + + align:start position:0% +you can see how you can use that so the +base here's some nice results this is + + align:start position:0% +base here's some nice results this is + + + align:start position:0% +base here's some nice results this is +from mark lavoy's work so this is + + align:start position:0% +from mark lavoy's work so this is + + + align:start position:0% +from mark lavoy's work so this is +actually a light field uh microscopy + + align:start position:0% +actually a light field uh microscopy + + + align:start position:0% +actually a light field uh microscopy +image but the ideas are the same you + + align:start position:0% +image but the ideas are the same you + + + align:start position:0% +image but the ideas are the same you +could do deconvolution you can see he + + align:start position:0% +could do deconvolution you can see he + + + align:start position:0% +could do deconvolution you can see he +goes from something that this is what a + + align:start position:0% +goes from something that this is what a + + + align:start position:0% +goes from something that this is what a +typical microscope would produce we have + + align:start position:0% +typical microscope would produce we have + + + align:start position:0% +typical microscope would produce we have +this thick specimen but it's optically + + align:start position:0% +this thick specimen but it's optically + + + align:start position:0% +this thick specimen but it's optically +transparent we produce a nice + + align:start position:0% +transparent we produce a nice + + + align:start position:0% +transparent we produce a nice +tomographic image which we can then + + align:start position:0% +tomographic image which we can then + + + align:start position:0% +tomographic image which we can then +volume render and so if you go to + + align:start position:0% +volume render and so if you go to + + + align:start position:0% +volume render and so if you go to +you know some really expensive + + align:start position:0% +you know some really expensive + + + align:start position:0% +you know some really expensive +commercial packages this is sort of what + + align:start position:0% +commercial packages this is sort of what + + + align:start position:0% +commercial packages this is sort of what +you'll see for a deconvolution so you'll + + align:start position:0% +you'll see for a deconvolution so you'll + + + align:start position:0% +you'll see for a deconvolution so you'll +go from something on the left which has + + align:start position:0% +go from something on the left which has + + + align:start position:0% +go from something on the left which has +all the autofocus blur just some nice + + align:start position:0% +all the autofocus blur just some nice + + + align:start position:0% +all the autofocus blur just some nice +sharp all-in-focus image of an object + + align:start position:0% +sharp all-in-focus image of an object + + + align:start position:0% +sharp all-in-focus image of an object +with a lot of depth to it right so you + + align:start position:0% +with a lot of depth to it right so you + + + align:start position:0% +with a lot of depth to it right so you +can study the fine structure + + align:start position:0% +can study the fine structure + + + align:start position:0% +can study the fine structure +and so then + + align:start position:0% + + + + align:start position:0% + +i think we have a little time left let's + + align:start position:0% +i think we have a little time left let's + + + align:start position:0% +i think we have a little time left let's +look at some other tricks they use in + + align:start position:0% +look at some other tricks they use in + + + align:start position:0% +look at some other tricks they use in +biology so again the theme in all of + + align:start position:0% +biology so again the theme in all of + + + align:start position:0% +biology so again the theme in all of +these laminography tomography is always + + align:start position:0% +these laminography tomography is always + + + align:start position:0% +these laminography tomography is always +to remove the out-of-focus blur so we + + align:start position:0% +to remove the out-of-focus blur so we + + + align:start position:0% +to remove the out-of-focus blur so we +get a nice cross-sectional image right + + align:start position:0% +get a nice cross-sectional image right + + + align:start position:0% +get a nice cross-sectional image right +so we can see the tumors we can see + + align:start position:0% +so we can see the tumors we can see + + + align:start position:0% +so we can see the tumors we can see +structures clearly + + align:start position:0% +structures clearly + + + align:start position:0% +structures clearly +and so this idea + + align:start position:0% +and so this idea + + + align:start position:0% +and so this idea +is really nice and again i don't have + + align:start position:0% +is really nice and again i don't have + + + align:start position:0% +is really nice and again i don't have +time to show you but there have been two + + align:start position:0% +time to show you but there have been two + + + align:start position:0% +time to show you but there have been two +or three + + align:start position:0% +or three + + + align:start position:0% +or three +computational photography cigarette + + align:start position:0% +computational photography cigarette + + + align:start position:0% +computational photography cigarette +papers again from markleboy using this + + align:start position:0% +papers again from markleboy using this + + + align:start position:0% +papers again from markleboy using this +idea see this theme just keeps coming up + + align:start position:0% +idea see this theme just keeps coming up + + + align:start position:0% +idea see this theme just keeps coming up +you go to the medical literature look + + align:start position:0% +you go to the medical literature look + + + align:start position:0% +you go to the medical literature look +what they were doing in the 60s and 70s + + align:start position:0% +what they were doing in the 60s and 70s + + + align:start position:0% +what they were doing in the 60s and 70s +figure out how exactly it maps onto a + + align:start position:0% +figure out how exactly it maps onto a + + + align:start position:0% +figure out how exactly it maps onto a +camera do it you're published that's + + align:start position:0% +camera do it you're published that's + + + align:start position:0% +camera do it you're published that's +basically the algorithm although + + align:start position:0% +basically the algorithm although + + + align:start position:0% +basically the algorithm although +it's becoming harder to do that because + + align:start position:0% +it's becoming harder to do that because + + + align:start position:0% +it's becoming harder to do that because +too many of us have used that algorithm + + align:start position:0% +too many of us have used that algorithm + + + align:start position:0% +too many of us have used that algorithm +for papers so + + align:start position:0% +for papers so + + + align:start position:0% +for papers so +the idea behind uh confocal microscopy + + align:start position:0% +the idea behind uh confocal microscopy + + + align:start position:0% +the idea behind uh confocal microscopy +which you can be proud of marvin minsky + + align:start position:0% +which you can be proud of marvin minsky + + + align:start position:0% +which you can be proud of marvin minsky +is arguably credited with the invention + + align:start position:0% +is arguably credited with the invention + + + align:start position:0% +is arguably credited with the invention +of it uh here at the media lab and yeah + + align:start position:0% +of it uh here at the media lab and yeah + + + align:start position:0% +of it uh here at the media lab and yeah +live as well so + + align:start position:0% +live as well so + + + align:start position:0% +live as well so +the basic idea is i want i have some + + align:start position:0% +the basic idea is i want i have some + + + align:start position:0% +the basic idea is i want i have some +plane in our my specimen that i want to + + align:start position:0% +plane in our my specimen that i want to + + + align:start position:0% +plane in our my specimen that i want to +get a nice cross-sectional image up and + + align:start position:0% +get a nice cross-sectional image up and + + + align:start position:0% +get a nice cross-sectional image up and +i want everything that's out of focus to + + align:start position:0% +i want everything that's out of focus to + + + align:start position:0% +i want everything that's out of focus to +not contribute anything to the final + + align:start position:0% +not contribute anything to the final + + + align:start position:0% +not contribute anything to the final +image + + align:start position:0% +image + + + align:start position:0% +image +right so i can do that computationally + + align:start position:0% +right so i can do that computationally + + + align:start position:0% +right so i can do that computationally +by doing this deconvolution + + align:start position:0% +by doing this deconvolution + + + align:start position:0% +by doing this deconvolution +and that's sort of like ct scanning or i + + align:start position:0% +and that's sort of like ct scanning or i + + + align:start position:0% +and that's sort of like ct scanning or i +can do it mechanically which is sort of + + align:start position:0% +can do it mechanically which is sort of + + + align:start position:0% +can do it mechanically which is sort of +like laminography there'll be no + + align:start position:0% +like laminography there'll be no + + + align:start position:0% +like laminography there'll be no +computation here at all i'm just going + + align:start position:0% +computation here at all i'm just going + + + align:start position:0% +computation here at all i'm just going +to make sure that the point spread + + align:start position:0% +to make sure that the point spread + + + align:start position:0% +to make sure that the point spread +function + + align:start position:0% +function + + + align:start position:0% +function +right + + align:start position:0% +right + + + align:start position:0% +right +so if i go back to the point spread + + align:start position:0% +so if i go back to the point spread + + + align:start position:0% +so if i go back to the point spread +function this thing + + align:start position:0% +function this thing + + + align:start position:0% +function this thing +if this was just a point + + align:start position:0% +if this was just a point + + + align:start position:0% +if this was just a point +right then if you look at this math if + + align:start position:0% +right then if you look at this math if + + + align:start position:0% +right then if you look at this math if +you convolve a point with the object you + + align:start position:0% +you convolve a point with the object you + + + align:start position:0% +you convolve a point with the object you +just get the object again right so just + + align:start position:0% +just get the object again right so just + + + align:start position:0% +just get the object again right so just +like laminography sort of solve the + + align:start position:0% +like laminography sort of solve the + + + align:start position:0% +like laminography sort of solve the +problem mechanically if we can make this + + align:start position:0% +problem mechanically if we can make this + + + align:start position:0% +problem mechanically if we can make this +a point our impulse response is a point + + align:start position:0% +a point our impulse response is a point + + + align:start position:0% +a point our impulse response is a point +then we don't need to do deconvolution + + align:start position:0% +then we don't need to do deconvolution + + + align:start position:0% +then we don't need to do deconvolution +that's the main trick + + align:start position:0% +that's the main trick + + + align:start position:0% +that's the main trick +and so confocal microscopy does this in + + align:start position:0% +and so confocal microscopy does this in + + + align:start position:0% +and so confocal microscopy does this in +a very clever way we have some + + align:start position:0% +a very clever way we have some + + + align:start position:0% +a very clever way we have some +area light source put a pinhole in front + + align:start position:0% +area light source put a pinhole in front + + + align:start position:0% +area light source put a pinhole in front +of it okay now it goes through my thin + + align:start position:0% +of it okay now it goes through my thin + + + align:start position:0% +of it okay now it goes through my thin +lens and it goes it's focused based on + + align:start position:0% +lens and it goes it's focused based on + + + align:start position:0% +lens and it goes it's focused based on +the focal length down onto some point in + + align:start position:0% +the focal length down onto some point in + + + align:start position:0% +the focal length down onto some point in +the plane we care about + + align:start position:0% +the plane we care about + + + align:start position:0% +the plane we care about +okay so if i was to now take a picture + + align:start position:0% +okay so if i was to now take a picture + + + align:start position:0% +okay so if i was to now take a picture +somehow of this plane right + + align:start position:0% +somehow of this plane right + + + align:start position:0% +somehow of this plane right +then all i'd see would be things that + + align:start position:0% +then all i'd see would be things that + + + align:start position:0% +then all i'd see would be things that +get illuminated by this beam of light + + align:start position:0% +get illuminated by this beam of light + + + align:start position:0% +get illuminated by this beam of light +right everything else is not eliminated + + align:start position:0% +right everything else is not eliminated + + + align:start position:0% +right everything else is not eliminated +right + + align:start position:0% +right + + + align:start position:0% +right +so we're already doing okay because + + align:start position:0% +so we're already doing okay because + + + align:start position:0% +so we're already doing okay because +things way over here + + align:start position:0% +things way over here + + + align:start position:0% +things way over here +aren't going to contribute to the blur + + align:start position:0% +aren't going to contribute to the blur + + + align:start position:0% +aren't going to contribute to the blur +at all + + align:start position:0% +at all + + + align:start position:0% +at all +right so that's the purpose of the + + align:start position:0% +right so that's the purpose of the + + + align:start position:0% +right so that's the purpose of the +pinhole let's make this clear + + align:start position:0% +pinhole let's make this clear + + + align:start position:0% +pinhole let's make this clear +if i look at some point so again let's + + align:start position:0% +if i look at some point so again let's + + + align:start position:0% +if i look at some point so again let's +think about the mandible we saw earlier + + align:start position:0% +think about the mandible we saw earlier + + + align:start position:0% +think about the mandible we saw earlier +if we have some point that's higher in + + align:start position:0% +if we have some point that's higher in + + + align:start position:0% +if we have some point that's higher in +depth than the plane we're trying to + + align:start position:0% +depth than the plane we're trying to + + + align:start position:0% +depth than the plane we're trying to +focus on right then the light will be + + align:start position:0% +focus on right then the light will be + + + align:start position:0% +focus on right then the light will be +spread over a disk + + align:start position:0% +spread over a disk + + + align:start position:0% +spread over a disk +does that make sense we're going to take + + align:start position:0% +does that make sense we're going to take + + + align:start position:0% +does that make sense we're going to take +this cut through our cone of light + + align:start position:0% +this cut through our cone of light + + + align:start position:0% +this cut through our cone of light +right so as a function of radius or + + align:start position:0% +right so as a function of radius or + + + align:start position:0% +right so as a function of radius or +depth away from the plane we care about + + align:start position:0% +depth away from the plane we care about + + + align:start position:0% +depth away from the plane we care about +it's going to fall like what + + align:start position:0% +it's going to fall like what + + + align:start position:0% +it's going to fall like what +the brightness of that point + + align:start position:0% + + + + align:start position:0% + +yeah 1 over r squared great + + align:start position:0% +yeah 1 over r squared great + + + align:start position:0% +yeah 1 over r squared great +so already if you look think about our + + align:start position:0% +so already if you look think about our + + + align:start position:0% +so already if you look think about our +impulse response we had earlier + + align:start position:0% +impulse response we had earlier + + + align:start position:0% +impulse response we had earlier +right + + align:start position:0% +right + + + align:start position:0% +right +so it follows one over r squared now + + align:start position:0% +so it follows one over r squared now + + + align:start position:0% +so it follows one over r squared now +right + + align:start position:0% +right + + + align:start position:0% +right +that's not bad but can we make it even + + align:start position:0% +that's not bad but can we make it even + + + align:start position:0% +that's not bad but can we make it even +sharper any ideas + + align:start position:0% + + + + align:start position:0% + +higher numerical aperture + + align:start position:0% +higher numerical aperture + + + align:start position:0% +higher numerical aperture +that will spread the energy out it'll + + align:start position:0% +that will spread the energy out it'll + + + align:start position:0% +that will spread the energy out it'll +make it somewhat sharper that's right + + align:start position:0% + + + + align:start position:0% + +so the key trick + + align:start position:0% +so the key trick + + + align:start position:0% +so the key trick +oh you saw it previewed if anyone saw it + + align:start position:0% +oh you saw it previewed if anyone saw it + + + align:start position:0% +oh you saw it previewed if anyone saw it +does anyone think so that we're only + + align:start position:0% +does anyone think so that we're only + + + align:start position:0% +does anyone think so that we're only +doing thing on things on the lighting + + align:start position:0% +doing thing on things on the lighting + + + align:start position:0% +doing thing on things on the lighting +side we haven't considered how we take + + align:start position:0% +side we haven't considered how we take + + + align:start position:0% +side we haven't considered how we take +the picture yet + + align:start position:0% +the picture yet + + + align:start position:0% +the picture yet +it turns out you can use the exact same + + align:start position:0% +it turns out you can use the exact same + + + align:start position:0% +it turns out you can use the exact same +trick + + align:start position:0% +trick + + + align:start position:0% +trick +so to take the picture of this one point + + align:start position:0% +so to take the picture of this one point + + + align:start position:0% +so to take the picture of this one point +on the plane of focus we care about + + align:start position:0% +on the plane of focus we care about + + + align:start position:0% +on the plane of focus we care about +we're just going to put a big photocell + + align:start position:0% +we're just going to put a big photocell + + + align:start position:0% +we're just going to put a big photocell +here we photodiode + + align:start position:0% +here we photodiode + + + align:start position:0% +here we photodiode +right so if i didn't do anything + + align:start position:0% +right so if i didn't do anything + + + align:start position:0% +right so if i didn't do anything +and i put a beam splitter here + + align:start position:0% +and i put a beam splitter here + + + align:start position:0% +and i put a beam splitter here +right + + align:start position:0% +right + + + align:start position:0% +right +and this light would just fall on the + + align:start position:0% +and this light would just fall on the + + + align:start position:0% +and this light would just fall on the +photocell all over a big region so you + + align:start position:0% +photocell all over a big region so you + + + align:start position:0% +photocell all over a big region so you +have low s and r if you didn't have a + + align:start position:0% +have low s and r if you didn't have a + + + align:start position:0% +have low s and r if you didn't have a +lens here you need the lens of course + + align:start position:0% +lens here you need the lens of course + + + align:start position:0% +lens here you need the lens of course +right so we put a lens + + align:start position:0% +right so we put a lens + + + align:start position:0% +right so we put a lens +that focuses on this plane as well + + align:start position:0% +that focuses on this plane as well + + + align:start position:0% +that focuses on this plane as well +so it collects all the light scattered + + align:start position:0% +so it collects all the light scattered + + + align:start position:0% +so it collects all the light scattered +by this point back onto our photo dial + + align:start position:0% +by this point back onto our photo dial + + + align:start position:0% +by this point back onto our photo dial +right so if we put our photo down at + + align:start position:0% +right so if we put our photo down at + + + align:start position:0% +right so if we put our photo down at +this point + + align:start position:0% +this point + + + align:start position:0% +this point +we get a nice image + + align:start position:0% +we get a nice image + + + align:start position:0% +we get a nice image +but then if we took a focal stack + + align:start position:0% +but then if we took a focal stack + + + align:start position:0% +but then if we took a focal stack +right then the points out of focus would + + align:start position:0% +right then the points out of focus would + + + align:start position:0% +right then the points out of focus would +be + + align:start position:0% +be + + + align:start position:0% +be +have intensity one over r squared right + + align:start position:0% +have intensity one over r squared right + + + align:start position:0% +have intensity one over r squared right +but we can do better than that because + + align:start position:0% +but we can do better than that because + + + align:start position:0% +but we can do better than that because +now we can put a pinhole + + align:start position:0% +now we can put a pinhole + + + align:start position:0% +now we can put a pinhole +in front of our photocell + + align:start position:0% +in front of our photocell + + + align:start position:0% +in front of our photocell +right + + align:start position:0% +right + + + align:start position:0% +right +so if you think about this + + align:start position:0% +so if you think about this + + + align:start position:0% +so if you think about this +our image say you take this blur disk + + align:start position:0% +our image say you take this blur disk + + + align:start position:0% +our image say you take this blur disk +and you image it it images to a disk + + align:start position:0% +and you image it it images to a disk + + + align:start position:0% +and you image it it images to a disk +but then we're just going to take that + + align:start position:0% +but then we're just going to take that + + + align:start position:0% +but then we're just going to take that +little part in the center of the disk + + align:start position:0% +little part in the center of the disk + + + align:start position:0% +little part in the center of the disk +right so it turns out the imaging side + + align:start position:0% +right so it turns out the imaging side + + + align:start position:0% +right so it turns out the imaging side +by putting a pinhole on your photodiode + + align:start position:0% +by putting a pinhole on your photodiode + + + align:start position:0% +by putting a pinhole on your photodiode +also gives you a function of one over r + + align:start position:0% +also gives you a function of one over r + + + align:start position:0% +also gives you a function of one over r +squared so it actually goes one over r + + align:start position:0% +squared so it actually goes one over r + + + align:start position:0% +squared so it actually goes one over r +to the fourth now which is quite strong + + align:start position:0% +to the fourth now which is quite strong + + + align:start position:0% +to the fourth now which is quite strong +so that deconvolution isn't really + + align:start position:0% +so that deconvolution isn't really + + + align:start position:0% +so that deconvolution isn't really +needed anymore does that make sense and + + align:start position:0% +needed anymore does that make sense and + + + align:start position:0% +needed anymore does that make sense and +so that's why it's called confocal you + + align:start position:0% +so that's why it's called confocal you + + + align:start position:0% +so that's why it's called confocal you +have two pinholes two focal systems and + + align:start position:0% +have two pinholes two focal systems and + + + align:start position:0% +have two pinholes two focal systems and +they're aligned with each item + + align:start position:0% +they're aligned with each item + + + align:start position:0% +they're aligned with each item +but then of course how are you gonna get + + align:start position:0% +but then of course how are you gonna get + + + align:start position:0% +but then of course how are you gonna get +a picture you're gonna have to scan this + + align:start position:0% +a picture you're gonna have to scan this + + + align:start position:0% +a picture you're gonna have to scan this +thing which can take a lot of time right + + align:start position:0% +thing which can take a lot of time right + + + align:start position:0% +thing which can take a lot of time right +so you're going to have to move the + + align:start position:0% +so you're going to have to move the + + + align:start position:0% +so you're going to have to move the +pinholes on the light source + + align:start position:0% +pinholes on the light source + + + align:start position:0% +pinholes on the light source +and the detector in 2d raster scan the + + align:start position:0% +and the detector in 2d raster scan the + + + align:start position:0% +and the detector in 2d raster scan the +whole object right + + align:start position:0% +whole object right + + + align:start position:0% +whole object right +so that's really the limitation of this + + align:start position:0% +so that's really the limitation of this + + + align:start position:0% +so that's really the limitation of this +technique by doing deconvolution by + + align:start position:0% +technique by doing deconvolution by + + + align:start position:0% +technique by doing deconvolution by +doing tricks to make the psf invertible + + align:start position:0% +doing tricks to make the psf invertible + + + align:start position:0% +doing tricks to make the psf invertible +we can do it all in one shot + + align:start position:0% +we can do it all in one shot + + + align:start position:0% +we can do it all in one shot +but with confocal microscopy before we + + align:start position:0% +but with confocal microscopy before we + + + align:start position:0% +but with confocal microscopy before we +had computers + + align:start position:0% +had computers + + + align:start position:0% +had computers +we could do that without needing + + align:start position:0% +we could do that without needing + + + align:start position:0% +we could do that without needing +inversion so you see the trade right it + + align:start position:0% +inversion so you see the trade right it + + + align:start position:0% +inversion so you see the trade right it +should be the same trade as laminography + + align:start position:0% +should be the same trade as laminography + + + align:start position:0% +should be the same trade as laminography +and tomography + + align:start position:0% +and tomography + + + align:start position:0% +and tomography +and so then i should probably finish up + + align:start position:0% +and so then i should probably finish up + + + align:start position:0% +and so then i should probably finish up +right yeah + + align:start position:0% +right yeah + + + align:start position:0% +right yeah +so uh we're getting right near the end + + align:start position:0% +so uh we're getting right near the end + + + align:start position:0% +so uh we're getting right near the end +now so this is used in practice not + + align:start position:0% +now so this is used in practice not + + + align:start position:0% +now so this is used in practice not +quite the way i described it took + + align:start position:0% +quite the way i described it took + + + align:start position:0% +quite the way i described it took +a decade or two to commercialize marvin + + align:start position:0% +a decade or two to commercialize marvin + + + align:start position:0% +a decade or two to commercialize marvin +minsky's idea and this is sort of how + + align:start position:0% +minsky's idea and this is sort of how + + + align:start position:0% +minsky's idea and this is sort of how +it's used in biology and practice now + + align:start position:0% +it's used in biology and practice now + + + align:start position:0% +it's used in biology and practice now +it's called laser scanning confocal + + align:start position:0% +it's called laser scanning confocal + + + align:start position:0% +it's called laser scanning confocal +microscopy the idea is basically the + + align:start position:0% +microscopy the idea is basically the + + + align:start position:0% +microscopy the idea is basically the +same you have a laser source + + align:start position:0% +same you have a laser source + + + align:start position:0% +same you have a laser source +a minimal aperture on both the source + + align:start position:0% +a minimal aperture on both the source + + + align:start position:0% +a minimal aperture on both the source +and the detector and a photodiode and a + + align:start position:0% +and the detector and a photodiode and a + + + align:start position:0% +and the detector and a photodiode and a +special beam splitter we'll get to that + + align:start position:0% +special beam splitter we'll get to that + + + align:start position:0% +special beam splitter we'll get to that +what we do is really it's just like c2 + + align:start position:0% +what we do is really it's just like c2 + + + align:start position:0% +what we do is really it's just like c2 +scans you don't really just care about + + align:start position:0% +scans you don't really just care about + + + align:start position:0% +scans you don't really just care about +the absolute density function often you + + align:start position:0% +the absolute density function often you + + + align:start position:0% +the absolute density function often you +add some contrast agent right so if + + align:start position:0% +add some contrast agent right so if + + + align:start position:0% +add some contrast agent right so if +you're looking for a pulmonary edema you + + align:start position:0% +you're looking for a pulmonary edema you + + + align:start position:0% +you're looking for a pulmonary edema you +inject iodine into the veins + + align:start position:0% +inject iodine into the veins + + + align:start position:0% +inject iodine into the veins +iodine absorbs + + align:start position:0% +iodine absorbs + + + align:start position:0% +iodine absorbs +x-rays and so then you can look at the + + align:start position:0% +x-rays and so then you can look at the + + + align:start position:0% +x-rays and so then you can look at the +vein structures and how they evolve over + + align:start position:0% +vein structures and how they evolve over + + + align:start position:0% +vein structures and how they evolve over +time so they want to look at specific + + align:start position:0% +time so they want to look at specific + + + align:start position:0% +time so they want to look at specific +structures inside cells they don't just + + align:start position:0% +structures inside cells they don't just + + + align:start position:0% +structures inside cells they don't just +want a gross picture of a cell they want + + align:start position:0% +want a gross picture of a cell they want + + + align:start position:0% +want a gross picture of a cell they want +to they want to enhance certain details + + align:start position:0% +to they want to enhance certain details + + + align:start position:0% +to they want to enhance certain details +so what they use is fluorescent beads + + align:start position:0% +so what they use is fluorescent beads + + + align:start position:0% +so what they use is fluorescent beads +usually with some antigen tags for the + + align:start position:0% +usually with some antigen tags for the + + + align:start position:0% +usually with some antigen tags for the +biologists anyways i'll skip that they + + align:start position:0% +biologists anyways i'll skip that they + + + align:start position:0% +biologists anyways i'll skip that they +basically highlight they put fluorescent + + align:start position:0% +basically highlight they put fluorescent + + + align:start position:0% +basically highlight they put fluorescent +dyes + + align:start position:0% +dyes + + + align:start position:0% +dyes +somehow attached to structures they care + + align:start position:0% +somehow attached to structures they care + + + align:start position:0% +somehow attached to structures they care +about right + + align:start position:0% +about right + + + align:start position:0% +about right +so for instance mitochondria cell + + align:start position:0% +so for instance mitochondria cell + + + align:start position:0% +so for instance mitochondria cell +structures dna what have you and that + + align:start position:0% +structures dna what have you and that + + + align:start position:0% +structures dna what have you and that +will enhance the contrast in the final + + align:start position:0% +will enhance the contrast in the final + + + align:start position:0% +will enhance the contrast in the final +image and then what happens is the flexo + + align:start position:0% +image and then what happens is the flexo + + + align:start position:0% +image and then what happens is the flexo +beads are designed to fluoresce at some + + align:start position:0% +beads are designed to fluoresce at some + + + align:start position:0% +beads are designed to fluoresce at some +wavelength which is different than your + + align:start position:0% +wavelength which is different than your + + + align:start position:0% +wavelength which is different than your +source wavelength + + align:start position:0% +source wavelength + + + align:start position:0% +source wavelength +and then you have the beam splitter + + align:start position:0% +and then you have the beam splitter + + + align:start position:0% +and then you have the beam splitter +again but you have a filter on this beam + + align:start position:0% +again but you have a filter on this beam + + + align:start position:0% +again but you have a filter on this beam +splitter that only reflects + + align:start position:0% +splitter that only reflects + + + align:start position:0% +splitter that only reflects +the fluorescent wavelength not the + + align:start position:0% +the fluorescent wavelength not the + + + align:start position:0% +the fluorescent wavelength not the +stimulating wave + + align:start position:0% +stimulating wave + + + align:start position:0% +stimulating wave +right so that improves your contrast + + align:start position:0% +right so that improves your contrast + + + align:start position:0% +right so that improves your contrast +even more so that's the basic trick + + align:start position:0% +even more so that's the basic trick + + + align:start position:0% +even more so that's the basic trick +behind laser scanning focal microscopy + + align:start position:0% +behind laser scanning focal microscopy + + + align:start position:0% +behind laser scanning focal microscopy +but again you have to scan mechanically + + align:start position:0% +but again you have to scan mechanically + + + align:start position:0% +but again you have to scan mechanically +both the light source aperture and the + + align:start position:0% +both the light source aperture and the + + + align:start position:0% +both the light source aperture and the +detector aperture so this is a slow + + align:start position:0% +detector aperture so this is a slow + + + align:start position:0% +detector aperture so this is a slow +process but cellular division also a + + align:start position:0% +process but cellular division also a + + + align:start position:0% +process but cellular division also a +slow process so we can create videos of + + align:start position:0% +slow process so we can create videos of + + + align:start position:0% +slow process so we can create videos of +that + + align:start position:0% +that + + + align:start position:0% +that +for instance here you can see + + align:start position:0% +for instance here you can see + + + align:start position:0% +for instance here you can see +typical cellular division process where + + align:start position:0% +typical cellular division process where + + + align:start position:0% +typical cellular division process where +i think they've probably accentuated the + + align:start position:0% +i think they've probably accentuated the + + + align:start position:0% +i think they've probably accentuated the +telomeres so you can see them separate + + align:start position:0% +telomeres so you can see them separate + + + align:start position:0% +telomeres so you can see them separate +i'm guessing + + align:start position:0% + + + + align:start position:0% + +right so again cellular division occurs + + align:start position:0% +right so again cellular division occurs + + + align:start position:0% +right so again cellular division occurs +on a long enough time scale that we can + + align:start position:0% +on a long enough time scale that we can + + + align:start position:0% +on a long enough time scale that we can +raster scan that without any + + align:start position:0% +raster scan that without any + + + align:start position:0% +raster scan that without any +difficulties in creating videos + + align:start position:0% +difficulties in creating videos + + + align:start position:0% +difficulties in creating videos +and then just to show you how good the + + align:start position:0% +and then just to show you how good the + + + align:start position:0% +and then just to show you how good the +cross sectional image is i think this is + + align:start position:0% +cross sectional image is i think this is + + + align:start position:0% +cross sectional image is i think this is +a pollen grain + + align:start position:0% +a pollen grain + + + align:start position:0% +a pollen grain +here you can see that + + align:start position:0% +here you can see that + + + align:start position:0% +here you can see that +this is again without any deconvolution + + align:start position:0% +this is again without any deconvolution + + + align:start position:0% +this is again without any deconvolution +no computation you're creating this + + align:start position:0% +no computation you're creating this + + + align:start position:0% +no computation you're creating this +function and then you can take a slice + + align:start position:0% +function and then you can take a slice + + + align:start position:0% +function and then you can take a slice +of the function and you'll see it evolve + + align:start position:0% +of the function and you'll see it evolve + + + align:start position:0% +of the function and you'll see it evolve +on the right here these cross-sectional + + align:start position:0% +on the right here these cross-sectional + + + align:start position:0% +on the right here these cross-sectional +images are very sharp + + align:start position:0% + + + + align:start position:0% + +and again by using the fluorescent beads + + align:start position:0% +and again by using the fluorescent beads + + + align:start position:0% +and again by using the fluorescent beads +you can enhance the contrast as well + + align:start position:0% + + + + align:start position:0% + +so this is this idea taken to its + + align:start position:0% +so this is this idea taken to its + + + align:start position:0% +so this is this idea taken to its +natural conclusion this is the + + align:start position:0% +natural conclusion this is the + + + align:start position:0% +natural conclusion this is the +commercial product you get at the end + + align:start position:0% +commercial product you get at the end + + + align:start position:0% +commercial product you get at the end +and so now again to plug some of my own + + align:start position:0% +and so now again to plug some of my own + + + align:start position:0% +and so now again to plug some of my own +work uh well this isn't my own work but + + align:start position:0% +work uh well this isn't my own work but + + + align:start position:0% +work uh well this isn't my own work but +oops + + align:start position:0% +oops + + + align:start position:0% +oops +uh i want to talk just briefly about + + align:start position:0% +uh i want to talk just briefly about + + + align:start position:0% +uh i want to talk just briefly about +coated aperture names coded aperture + + align:start position:0% +coated aperture names coded aperture + + + align:start position:0% +coated aperture names coded aperture +images we talked about biology medical + + align:start position:0% +images we talked about biology medical + + + align:start position:0% +images we talked about biology medical +imaging a little bit about geology so + + align:start position:0% +imaging a little bit about geology so + + + align:start position:0% +imaging a little bit about geology so +now it's not leaving the astronomers out + + align:start position:0% +now it's not leaving the astronomers out + + + align:start position:0% +now it's not leaving the astronomers out +and so what sort of ideas can we mine + + align:start position:0% +and so what sort of ideas can we mine + + + align:start position:0% +and so what sort of ideas can we mine +from the field of astronomical imaging + + align:start position:0% +from the field of astronomical imaging + + + align:start position:0% +from the field of astronomical imaging +and i think + + align:start position:0% +and i think + + + align:start position:0% +and i think +the main takeaway message that's + + align:start position:0% +the main takeaway message that's + + + align:start position:0% +the main takeaway message that's +impacted computational photography is + + align:start position:0% +impacted computational photography is + + + align:start position:0% +impacted computational photography is +idea of coded apertures right so if i'm + + align:start position:0% +idea of coded apertures right so if i'm + + + align:start position:0% +idea of coded apertures right so if i'm +imaging in x-rays i'm looking for + + align:start position:0% +imaging in x-rays i'm looking for + + + align:start position:0% +imaging in x-rays i'm looking for +supernova bursts what have you uh it's + + align:start position:0% +supernova bursts what have you uh it's + + + align:start position:0% +supernova bursts what have you uh it's +impractical to build refractive optics + + align:start position:0% +impractical to build refractive optics + + + align:start position:0% +impractical to build refractive optics +really all you can do is attenuate + + align:start position:0% +really all you can do is attenuate + + + align:start position:0% +really all you can do is attenuate +x-rays you can build lead lead sheets + + align:start position:0% +x-rays you can build lead lead sheets + + + align:start position:0% +x-rays you can build lead lead sheets +like we did in our project + + align:start position:0% +like we did in our project + + + align:start position:0% +like we did in our project +and block them in various ways and so + + align:start position:0% +and block them in various ways and so + + + align:start position:0% +and block them in various ways and so +then the question is how can you image + + align:start position:0% +then the question is how can you image + + + align:start position:0% +then the question is how can you image +a non non-refractive uh wavelengths + + align:start position:0% +a non non-refractive uh wavelengths + + + align:start position:0% +a non non-refractive uh wavelengths +or all with right so any ideas well the + + align:start position:0% +or all with right so any ideas well the + + + align:start position:0% +or all with right so any ideas well the +first idea of course is built pinhole + + align:start position:0% +first idea of course is built pinhole + + + align:start position:0% +first idea of course is built pinhole +apertures right + + align:start position:0% +apertures right + + + align:start position:0% +apertures right +so say i want to take an x-ray image of + + align:start position:0% +so say i want to take an x-ray image of + + + align:start position:0% +so say i want to take an x-ray image of +the world + + align:start position:0% +the world + + + align:start position:0% +the world +but i can't build a thin lens that that + + align:start position:0% +but i can't build a thin lens that that + + + align:start position:0% +but i can't build a thin lens that that +refracts x-rays + + align:start position:0% +refracts x-rays + + + align:start position:0% +refracts x-rays +so i i have this x-ray gumballs + + align:start position:0% +so i i have this x-ray gumballs + + + align:start position:0% +so i i have this x-ray gumballs +and i have i just take a lead sheet + + align:start position:0% +and i have i just take a lead sheet + + + align:start position:0% +and i have i just take a lead sheet +drill a hole in it i have an x-ray film + + align:start position:0% +drill a hole in it i have an x-ray film + + + align:start position:0% +drill a hole in it i have an x-ray film +no problem i get an image + + align:start position:0% +no problem i get an image + + + align:start position:0% +no problem i get an image +but i have exposure issues as always + + align:start position:0% +but i have exposure issues as always + + + align:start position:0% +but i have exposure issues as always +right so any guesses about how to solve + + align:start position:0% +right so any guesses about how to solve + + + align:start position:0% +right so any guesses about how to solve +the exposure issues + + align:start position:0% +the exposure issues + + + align:start position:0% +the exposure issues +as engineers what would be some tricks + + align:start position:0% +as engineers what would be some tricks + + + align:start position:0% +as engineers what would be some tricks +any ideas + + align:start position:0% + + + + align:start position:0% + +since we're a pinhole you want something + + align:start position:0% +since we're a pinhole you want something + + + align:start position:0% +since we're a pinhole you want something +else + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +so if we didn't know about deconvolution + + align:start position:0% +so if we didn't know about deconvolution + + + align:start position:0% +so if we didn't know about deconvolution +yet which it seems the wiki will tell + + align:start position:0% +yet which it seems the wiki will tell + + + align:start position:0% +yet which it seems the wiki will tell +you later um the first step to getting + + align:start position:0% +you later um the first step to getting + + + align:start position:0% +you later um the first step to getting +more light is just make a larger pinhole + + align:start position:0% +more light is just make a larger pinhole + + + align:start position:0% +more light is just make a larger pinhole +right so if you don't really care about + + align:start position:0% +right so if you don't really care about + + + align:start position:0% +right so if you don't really care about +the resolution of your scene you can + + align:start position:0% +the resolution of your scene you can + + + align:start position:0% +the resolution of your scene you can +afford to blur it + + align:start position:0% +afford to blur it + + + align:start position:0% +afford to blur it +right so if we're just looking at stars + + align:start position:0% +right so if we're just looking at stars + + + align:start position:0% +right so if we're just looking at stars +we can blur them we can make bigger + + align:start position:0% +we can blur them we can make bigger + + + align:start position:0% +we can blur them we can make bigger +pinholes and then deconvolve that maybe + + align:start position:0% +pinholes and then deconvolve that maybe + + + align:start position:0% +pinholes and then deconvolve that maybe +even though it's difficult to develop a + + align:start position:0% +even though it's difficult to develop a + + + align:start position:0% +even though it's difficult to develop a +circular aperture right so that's not a + + align:start position:0% +circular aperture right so that's not a + + + align:start position:0% +circular aperture right so that's not a +great solution but we're letting more + + align:start position:0% +great solution but we're letting more + + + align:start position:0% +great solution but we're letting more +light by the function of the radius + + align:start position:0% +light by the function of the radius + + + align:start position:0% +light by the function of the radius +squared + + align:start position:0% +squared + + + align:start position:0% +squared +but the real solution here is again + + align:start position:0% +but the real solution here is again + + + align:start position:0% +but the real solution here is again +called coated aperture and the idea + + align:start position:0% +called coated aperture and the idea + + + align:start position:0% +called coated aperture and the idea +is to drill many holes as kevin said in + + align:start position:0% +is to drill many holes as kevin said in + + + align:start position:0% +is to drill many holes as kevin said in +a way that all the images that overlap + + align:start position:0% +a way that all the images that overlap + + + align:start position:0% +a way that all the images that overlap +are somehow invertible and you saw this + + align:start position:0% +are somehow invertible and you saw this + + + align:start position:0% +are somehow invertible and you saw this +hopefully you remember back to when i + + align:start position:0% +hopefully you remember back to when i + + + align:start position:0% +hopefully you remember back to when i +was talking about the shieldfield + + align:start position:0% +was talking about the shieldfield + + + align:start position:0% +was talking about the shieldfield +project we put all these holes in front + + align:start position:0% +project we put all these holes in front + + + align:start position:0% +project we put all these holes in front +of the plane so that you could invert + + align:start position:0% +of the plane so that you could invert + + + align:start position:0% +of the plane so that you could invert +that system and so we weren't the first + + align:start position:0% +that system and so we weren't the first + + + align:start position:0% +that system and so we weren't the first +to discover this + + align:start position:0% +to discover this + + + align:start position:0% +to discover this +at least for for imaging of point + + align:start position:0% +at least for for imaging of point + + + align:start position:0% +at least for for imaging of point +sources and the basic idea is that as + + align:start position:0% +sources and the basic idea is that as + + + align:start position:0% +sources and the basic idea is that as +long as we design this mask + + align:start position:0% +long as we design this mask + + + align:start position:0% +long as we design this mask +appropriately + + align:start position:0% +appropriately + + + align:start position:0% +appropriately +so that that system of equations is well + + align:start position:0% +so that that system of equations is well + + + align:start position:0% +so that that system of equations is well +posed we can invert it and so here i'll + + align:start position:0% +posed we can invert it and so here i'll + + + align:start position:0% +posed we can invert it and so here i'll +show you something that's not well posed + + align:start position:0% +show you something that's not well posed + + + align:start position:0% +show you something that's not well posed +this is sort of like the the shieldfield + + align:start position:0% +this is sort of like the the shieldfield + + + align:start position:0% +this is sort of like the the shieldfield +side we saw earlier where we had three + + align:start position:0% +side we saw earlier where we had three + + + align:start position:0% +side we saw earlier where we had three +x-ray sources on all the time + + align:start position:0% +x-ray sources on all the time + + + align:start position:0% +x-ray sources on all the time +and those three images were overlapping + + align:start position:0% +and those three images were overlapping + + + align:start position:0% +and those three images were overlapping +on the sensor right so if we do this in + + align:start position:0% +on the sensor right so if we do this in + + + align:start position:0% +on the sensor right so if we do this in +the x-ray domain we have three images + + align:start position:0% +the x-ray domain we have three images + + + align:start position:0% +the x-ray domain we have three images +coming from three centers of projection + + align:start position:0% +coming from three centers of projection + + + align:start position:0% +coming from three centers of projection +they're all just shifts from one another + + align:start position:0% +they're all just shifts from one another + + + align:start position:0% +they're all just shifts from one another +right + + align:start position:0% +right + + + align:start position:0% +right +so you can imagine if i just had two pen + + align:start position:0% +so you can imagine if i just had two pen + + + align:start position:0% +so you can imagine if i just had two pen +holes + + align:start position:0% +holes + + + align:start position:0% +holes +and some prior on the scene it wouldn't + + align:start position:0% +and some prior on the scene it wouldn't + + + align:start position:0% +and some prior on the scene it wouldn't +be too difficult to separate two images + + align:start position:0% +be too difficult to separate two images + + + align:start position:0% +be too difficult to separate two images +right so that would double my light + + align:start position:0% +right so that would double my light + + + align:start position:0% +right so that would double my light +and i'd probably be able to invert that + + align:start position:0% +and i'd probably be able to invert that + + + align:start position:0% +and i'd probably be able to invert that +as kevin said that that would be easy + + align:start position:0% +as kevin said that that would be easy + + + align:start position:0% +as kevin said that that would be easy +enough to deconvolve probably + + align:start position:0% +enough to deconvolve probably + + + align:start position:0% +enough to deconvolve probably +although it wouldn't be a linear process + + align:start position:0% +although it wouldn't be a linear process + + + align:start position:0% +although it wouldn't be a linear process +problem so then as we add more and more + + align:start position:0% +problem so then as we add more and more + + + align:start position:0% +problem so then as we add more and more +pinholes we let in more light but that + + align:start position:0% +pinholes we let in more light but that + + + align:start position:0% +pinholes we let in more light but that +inversion that system of equations + + align:start position:0% +inversion that system of equations + + + align:start position:0% +inversion that system of equations +becomes more ill-posed it's condition + + align:start position:0% +becomes more ill-posed it's condition + + + align:start position:0% +becomes more ill-posed it's condition +number uh it's much worse so then that's + + align:start position:0% +number uh it's much worse so then that's + + + align:start position:0% +number uh it's much worse so then that's +where we end up in the sort of field of + + align:start position:0% +where we end up in the sort of field of + + + align:start position:0% +where we end up in the sort of field of +optimizing coded apertures which is what + + align:start position:0% +optimizing coded apertures which is what + + + align:start position:0% +optimizing coded apertures which is what +our work was on and so any of you sort + + align:start position:0% +our work was on and so any of you sort + + + align:start position:0% +our work was on and so any of you sort +of considering + + align:start position:0% +of considering + + + align:start position:0% +of considering +using masks for light field capture or + + align:start position:0% +using masks for light field capture or + + + align:start position:0% +using masks for light field capture or +other things it will very quickly arrive + + align:start position:0% +other things it will very quickly arrive + + + align:start position:0% +other things it will very quickly arrive +at similar results and the idea is to + + align:start position:0% +at similar results and the idea is to + + + align:start position:0% +at similar results and the idea is to +use + + align:start position:0% +use + + + align:start position:0% +use +in this case they generally use + + align:start position:0% +in this case they generally use + + + align:start position:0% +in this case they generally use +something called a mirror code and it's + + align:start position:0% +something called a mirror code and it's + + + align:start position:0% +something called a mirror code and it's +just designed + + align:start position:0% +just designed + + + align:start position:0% +just designed +uh i'll tell you the the main fact about + + align:start position:0% +uh i'll tell you the the main fact about + + + align:start position:0% +uh i'll tell you the the main fact about +the mirror code is that it's our auto + + align:start position:0% +the mirror code is that it's our auto + + + align:start position:0% +the mirror code is that it's our auto +correlation function is equal to a delta + + align:start position:0% +correlation function is equal to a delta + + + align:start position:0% +correlation function is equal to a delta +function and so if you think about + + align:start position:0% +function and so if you think about + + + align:start position:0% +function and so if you think about +deconvolution + + align:start position:0% +deconvolution + + + align:start position:0% +deconvolution +for those of you it seems that you + + align:start position:0% +for those of you it seems that you + + + align:start position:0% +for those of you it seems that you +aren't familiar with it that should tell + + align:start position:0% +aren't familiar with it that should tell + + + align:start position:0% +aren't familiar with it that should tell +you why you can you can do this but the + + align:start position:0% +you why you can you can do this but the + + + align:start position:0% +you why you can you can do this but the +basic idea is that the image formation + + align:start position:0% +basic idea is that the image formation + + + align:start position:0% +basic idea is that the image formation +process we can now model is linear we + + align:start position:0% +process we can now model is linear we + + + align:start position:0% +process we can now model is linear we +have a sequence of pinholes of varying + + align:start position:0% +have a sequence of pinholes of varying + + + align:start position:0% +have a sequence of pinholes of varying +sizes and distributions to image the + + align:start position:0% +sizes and distributions to image the + + + align:start position:0% +sizes and distributions to image the +to simulate the image we receive we can + + align:start position:0% +to simulate the image we receive we can + + + align:start position:0% +to simulate the image we receive we can +involve our aperture + + align:start position:0% +involve our aperture + + + align:start position:0% +involve our aperture +scaled scale the aperture with our + + align:start position:0% +scaled scale the aperture with our + + + align:start position:0% +scaled scale the aperture with our +function this is the image we get on the + + align:start position:0% +function this is the image we get on the + + + align:start position:0% +function this is the image we get on the +sensor + + align:start position:0% +sensor + + + align:start position:0% +sensor +and then believe it or not to deconvolve + + align:start position:0% +and then believe it or not to deconvolve + + + align:start position:0% +and then believe it or not to deconvolve +you simply convolve again + + align:start position:0% +you simply convolve again + + + align:start position:0% +you simply convolve again +to involve this blurred image the + + align:start position:0% +to involve this blurred image the + + + align:start position:0% +to involve this blurred image the +superimposed image with the aperture + + align:start position:0% +superimposed image with the aperture + + + align:start position:0% +superimposed image with the aperture +function + + align:start position:0% +function + + + align:start position:0% +function +and you actually get back in the absence + + align:start position:0% +and you actually get back in the absence + + + align:start position:0% +and you actually get back in the absence +of noise you get back exactly the image + + align:start position:0% +of noise you get back exactly the image + + + align:start position:0% +of noise you get back exactly the image +and really this is the key problem of + + align:start position:0% +and really this is the key problem of + + + align:start position:0% +and really this is the key problem of +coded aperture and something you can + + align:start position:0% +coded aperture and something you can + + + align:start position:0% +coded aperture and something you can +investigate there have been a couple + + align:start position:0% +investigate there have been a couple + + + align:start position:0% +investigate there have been a couple +papers from sheen iron others in recent + + align:start position:0% +papers from sheen iron others in recent + + + align:start position:0% +papers from sheen iron others in recent +years where they applied this again it + + align:start position:0% +years where they applied this again it + + + align:start position:0% +years where they applied this again it +took astronomy applied it to + + align:start position:0% +took astronomy applied it to + + + align:start position:0% +took astronomy applied it to +computational photography and they said + + align:start position:0% +computational photography and they said + + + align:start position:0% +computational photography and they said +okay we're going to put coded apertures + + align:start position:0% +okay we're going to put coded apertures + + + align:start position:0% +okay we're going to put coded apertures +and cameras + + align:start position:0% +and cameras + + + align:start position:0% +and cameras +but the key trick is what's that + + align:start position:0% +but the key trick is what's that + + + align:start position:0% +but the key trick is what's that +aperture going to be so that the + + align:start position:0% +aperture going to be so that the + + + align:start position:0% +aperture going to be so that the +inversion is well posed + + align:start position:0% +inversion is well posed + + + align:start position:0% +inversion is well posed +in the presence of noise paper so so + + align:start position:0% +in the presence of noise paper so so + + + align:start position:0% +in the presence of noise paper so so +that should inspire you hopefully for + + align:start position:0% +that should inspire you hopefully for + + + align:start position:0% +that should inspire you hopefully for +your final projects and then + + align:start position:0% +your final projects and then + + + align:start position:0% +your final projects and then +this uh has also been applied for + + align:start position:0% +this uh has also been applied for + + + align:start position:0% +this uh has also been applied for +tomography and so you can do exactly + + align:start position:0% +tomography and so you can do exactly + + + align:start position:0% +tomography and so you can do exactly +what our goal in our project was which + + align:start position:0% +what our goal in our project was which + + + align:start position:0% +what our goal in our project was which +is to have no moving part instantaneous + + align:start position:0% +is to have no moving part instantaneous + + + align:start position:0% +is to have no moving part instantaneous +tomography using some of these concepts + + align:start position:0% +tomography using some of these concepts + + + align:start position:0% +tomography using some of these concepts +the main challenge is doing it when + + align:start position:0% +the main challenge is doing it when + + + align:start position:0% +the main challenge is doing it when +objects are close to the detector and so + + align:start position:0% +objects are close to the detector and so + + + align:start position:0% +objects are close to the detector and so +that's really the problem that we solved + + align:start position:0% +that's really the problem that we solved + + + align:start position:0% +that's really the problem that we solved +in our work + + align:start position:0% +in our work + + + align:start position:0% +in our work +so that concludes my talk so thank you + + align:start position:0% +so that concludes my talk so thank you + + + align:start position:0% +so that concludes my talk so thank you +for your attention if you have any + + align:start position:0% +for your attention if you have any + + + align:start position:0% +for your attention if you have any +questions i'll be i'll take them nice + + align:start position:0% +questions i'll be i'll take them nice + + + align:start position:0% +questions i'll be i'll take them nice +work done + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +all right so + + align:start position:0% +all right so + + + align:start position:0% +all right so +light films and tomography one the same + + align:start position:0% +light films and tomography one the same + + + align:start position:0% +light films and tomography one the same +thing + + align:start position:0% + + + + align:start position:0% + +is that clear to everybody + + align:start position:0% + + + + align:start position:0% + +all right let's draw on the let's scroll + + align:start position:0% +all right let's draw on the let's scroll + + + align:start position:0% +all right let's draw on the let's scroll +the board + + align:start position:0% +the board + + + align:start position:0% +the board +yeah i think that link is the really the + + align:start position:0% +yeah i think that link is the really the + + + align:start position:0% +yeah i think that link is the really the +one you're next + + align:start position:0% + + + + align:start position:0% + +and so your assignment number two which + + align:start position:0% +and so your assignment number two which + + + align:start position:0% +and so your assignment number two which +was all about + + align:start position:0% +was all about + + + align:start position:0% +was all about +shifting and adding but your goal was to + + align:start position:0% +shifting and adding but your goal was to + + + align:start position:0% +shifting and adding but your goal was to +do refocusing over there so you had a + + align:start position:0% + + + + align:start position:0% + +bunch of cameras + + align:start position:0% + + + + align:start position:0% + +and you had some scene out here + + align:start position:0% +and you had some scene out here + + + align:start position:0% +and you had some scene out here +and when you wanted to refocus on a + + align:start position:0% +and when you wanted to refocus on a + + + align:start position:0% +and when you wanted to refocus on a +particular plane if you if you just sum + + align:start position:0% +particular plane if you if you just sum + + + align:start position:0% +particular plane if you if you just sum +up all these images + + align:start position:0% +up all these images + + + align:start position:0% +up all these images +then you're focusing at infinity + + align:start position:0% +then you're focusing at infinity + + + align:start position:0% +then you're focusing at infinity +but if you wanted to focus somewhere + + align:start position:0% +but if you wanted to focus somewhere + + + align:start position:0% +but if you wanted to focus somewhere +closer + + align:start position:0% +closer + + + align:start position:0% +closer +then you would appropriately add + + align:start position:0% +then you would appropriately add + + + align:start position:0% +then you would appropriately add +appropriately shift this image as + + align:start position:0% +appropriately shift this image as + + + align:start position:0% +appropriately shift this image as +something + + align:start position:0% +something + + + align:start position:0% +something +right but what is this particular image + + align:start position:0% +right but what is this particular image + + + align:start position:0% +right but what is this particular image +it's basically + + align:start position:0% +it's basically + + + align:start position:0% +it's basically +a + + align:start position:0% +a + + + align:start position:0% +a +image of a scene + + align:start position:0% +image of a scene + + + align:start position:0% +image of a scene +where all these rays are + + align:start position:0% +where all these rays are + + + align:start position:0% +where all these rays are +you can take a very simplified a bit + + align:start position:0% +you can take a very simplified a bit + + + align:start position:0% +you can take a very simplified a bit +more work and whole model here + + align:start position:0% +more work and whole model here + + + align:start position:0% +more work and whole model here +the projection of the scene + + align:start position:0% +the projection of the scene + + + align:start position:0% +the projection of the scene +onto the sensor + + align:start position:0% +onto the sensor + + + align:start position:0% +onto the sensor +when you move it over here + + align:start position:0% +when you move it over here + + + align:start position:0% +when you move it over here +is the same almost the same word + + align:start position:0% +is the same almost the same word + + + align:start position:0% +is the same almost the same word +being projected from a slightly + + align:start position:0% +being projected from a slightly + + + align:start position:0% +being projected from a slightly +different report + + align:start position:0% + + + + align:start position:0% + +and when you're doing tomography it's + + align:start position:0% +and when you're doing tomography it's + + + align:start position:0% +and when you're doing tomography it's +almost the same thing after you have + + align:start position:0% +almost the same thing after you have + + + align:start position:0% +almost the same thing after you have +uh + + align:start position:0% + + + + align:start position:0% + +and you have a extra source + + align:start position:0% +and you have a extra source + + + align:start position:0% +and you have a extra source +and you have an object here + + align:start position:0% +and you have an object here + + + align:start position:0% +and you have an object here +and you have + + align:start position:0% +and you have + + + align:start position:0% +and you have +projected + + align:start position:0% +projected + + + align:start position:0% +projected +this object onto the sensor + + align:start position:0% +this object onto the sensor + + + align:start position:0% +this object onto the sensor +and when you shift it around + + align:start position:0% +and when you shift it around + + + align:start position:0% +and when you shift it around +and put the extra source here + + align:start position:0% +and put the extra source here + + + align:start position:0% +and put the extra source here +you're again projecting this + + align:start position:0% +you're again projecting this + + + align:start position:0% +you're again projecting this +from a slightly different viewpoint + + align:start position:0% +from a slightly different viewpoint + + + align:start position:0% +from a slightly different viewpoint +so if as if this object was + + align:start position:0% +so if as if this object was + + + align:start position:0% +so if as if this object was +in this case as if the object was + + align:start position:0% +in this case as if the object was + + + align:start position:0% +in this case as if the object was +outside + + align:start position:0% +outside + + + align:start position:0% +outside +and you're projecting through this + + align:start position:0% +and you're projecting through this + + + align:start position:0% +and you're projecting through this +pinhole and taking an image on this + + align:start position:0% +pinhole and taking an image on this + + + align:start position:0% +pinhole and taking an image on this +detector + + align:start position:0% +detector + + + align:start position:0% +detector +and by by moving this + + align:start position:0% +and by by moving this + + + align:start position:0% +and by by moving this +uh pinhole in this case here + + align:start position:0% +uh pinhole in this case here + + + align:start position:0% +uh pinhole in this case here +you're taking different projections of + + align:start position:0% +you're taking different projections of + + + align:start position:0% +you're taking different projections of +the scene + + align:start position:0% +the scene + + + align:start position:0% +the scene +and over here you're taking different + + align:start position:0% +and over here you're taking different + + + align:start position:0% +and over here you're taking different +projections of what's inside here what's + + align:start position:0% +projections of what's inside here what's + + + align:start position:0% +projections of what's inside here what's +outside and here what's inside but the + + align:start position:0% +outside and here what's inside but the + + + align:start position:0% +outside and here what's inside but the +basic principle is the same which is + + align:start position:0% +basic principle is the same which is + + + align:start position:0% +basic principle is the same which is +you're changing the viewpoint and taking + + align:start position:0% +you're changing the viewpoint and taking + + + align:start position:0% +you're changing the viewpoint and taking +projection of consolidation + + align:start position:0% +projection of consolidation + + + align:start position:0% +projection of consolidation +and as doug explained + + align:start position:0% +and as doug explained + + + align:start position:0% +and as doug explained +this data set is sufficient + + align:start position:0% +this data set is sufficient + + + align:start position:0% +this data set is sufficient +uh you can express it as a radar + + align:start position:0% +uh you can express it as a radar + + + align:start position:0% +uh you can express it as a radar +transform and you can invert that to + + align:start position:0% +transform and you can invert that to + + + align:start position:0% +transform and you can invert that to +figure out what's inside + + align:start position:0% +figure out what's inside + + + align:start position:0% +figure out what's inside +so if this was uh some material that's + + align:start position:0% +so if this was uh some material that's + + + align:start position:0% +so if this was uh some material that's +simply attenuating and not scattering + + align:start position:0% +simply attenuating and not scattering + + + align:start position:0% +simply attenuating and not scattering +then you can figure out the density + + align:start position:0% +then you can figure out the density + + + align:start position:0% +then you can figure out the density +function + + align:start position:0% +function + + + align:start position:0% +function +in case of refocusing + + align:start position:0% +in case of refocusing + + + align:start position:0% +in case of refocusing +what you were doing was you're shifting + + align:start position:0% +what you were doing was you're shifting + + + align:start position:0% +what you were doing was you're shifting +and adding + + align:start position:0% +and adding + + + align:start position:0% +and adding +to focus on a particular play + + align:start position:0% +to focus on a particular play + + + align:start position:0% +to focus on a particular play +and that's the form of a tomography + + align:start position:0% +and that's the form of a tomography + + + align:start position:0% +and that's the form of a tomography +or at least a form of a libenography as + + align:start position:0% +or at least a form of a libenography as + + + align:start position:0% +or at least a form of a libenography as +we were looking at earlier because + + align:start position:0% +we were looking at earlier because + + + align:start position:0% +we were looking at earlier because +you're just looking at a slice which is + + align:start position:0% +you're just looking at a slice which is + + + align:start position:0% +you're just looking at a slice which is +exactly what the word + + align:start position:0% +exactly what the word + + + align:start position:0% +exactly what the word +means recording of the slice + + align:start position:0% +means recording of the slice + + + align:start position:0% +means recording of the slice +and + + align:start position:0% +and + + + align:start position:0% +and +the mathematics is identical + + align:start position:0% +the mathematics is identical + + + align:start position:0% +the mathematics is identical +because + + align:start position:0% +because + + + align:start position:0% +because +at least at least to the first order + + align:start position:0% +at least at least to the first order + + + align:start position:0% +at least at least to the first order +because the projections of the 3d world + + align:start position:0% +because the projections of the 3d world + + + align:start position:0% +because the projections of the 3d world +or a 2d sensor + + align:start position:0% +or a 2d sensor + + + align:start position:0% +or a 2d sensor +eventually allow you to compute + + align:start position:0% +eventually allow you to compute + + + align:start position:0% +eventually allow you to compute +something about the 3d mode from a set + + align:start position:0% +something about the 3d mode from a set + + + align:start position:0% +something about the 3d mode from a set +of 2d images you can say something about + + align:start position:0% +of 2d images you can say something about + + + align:start position:0% +of 2d images you can say something about +the 3d world + + align:start position:0% +the 3d world + + + align:start position:0% +the 3d world +uh in in in light photography you mostly + + align:start position:0% +uh in in in light photography you mostly + + + align:start position:0% +uh in in in light photography you mostly +care about creating refocused images one + + align:start position:0% +care about creating refocused images one + + + align:start position:0% +care about creating refocused images one +layer at a time + + align:start position:0% +layer at a time + + + align:start position:0% +layer at a time +but if this was also a + + align:start position:0% +but if this was also a + + + align:start position:0% +but if this was also a +some kind of + + align:start position:0% +some kind of + + + align:start position:0% +some kind of +an object + + align:start position:0% +an object + + + align:start position:0% +an object +which had some + + align:start position:0% + + + + align:start position:0% + +density + + align:start position:0% +density + + + align:start position:0% +density +a pure attenuation then again from all + + align:start position:0% +a pure attenuation then again from all + + + align:start position:0% +a pure attenuation then again from all +these sequence of images you can + + align:start position:0% +these sequence of images you can + + + align:start position:0% +these sequence of images you can +reconstruct + + align:start position:0% +reconstruct + + + align:start position:0% +reconstruct +what the volumetric representation of + + align:start position:0% +what the volumetric representation of + + + align:start position:0% +what the volumetric representation of +this object is + + align:start position:0% + + + + align:start position:0% + +okay there's one major difference though + + align:start position:0% +okay there's one major difference though + + + align:start position:0% +okay there's one major difference though +between + + align:start position:0% +between + + + align:start position:0% +between +uh a cat scan here + + align:start position:0% +uh a cat scan here + + + align:start position:0% +uh a cat scan here +versus a electric camera that's + + align:start position:0% +versus a electric camera that's + + + align:start position:0% +versus a electric camera that's +has an area of uh + + align:start position:0% +has an area of uh + + + align:start position:0% +has an area of uh +a light fluid that's made up of carrier + + align:start position:0% +a light fluid that's made up of carrier + + + align:start position:0% +a light fluid that's made up of carrier +cameras + + align:start position:0% +cameras + + + align:start position:0% +cameras +what's the major difference + + align:start position:0% + + + + align:start position:0% + +i have + + align:start position:0% +i have + + + align:start position:0% +i have +a parallel beam that's that's one + + align:start position:0% +a parallel beam that's that's one + + + align:start position:0% +a parallel beam that's that's one +example in fact this if you have an area + + align:start position:0% +example in fact this if you have an area + + + align:start position:0% +example in fact this if you have an area +of pin holes it's very similar to the + + align:start position:0% +of pin holes it's very similar to the + + + align:start position:0% +of pin holes it's very similar to the +cone beam typography + + align:start position:0% + + + + align:start position:0% + +there are two or three limitations that + + align:start position:0% +there are two or three limitations that + + + align:start position:0% +there are two or three limitations that +i've mentioned yeah + + align:start position:0% + + + + align:start position:0% + +angular + + align:start position:0% +angular + + + align:start position:0% +angular +your step size + + align:start position:0% +your step size + + + align:start position:0% +your step size +you're losing a lot of data in terms of + + align:start position:0% +you're losing a lot of data in terms of + + + align:start position:0% +you're losing a lot of data in terms of +angle as well as resolution here you + + align:start position:0% +angle as well as resolution here you + + + align:start position:0% +angle as well as resolution here you +might take thousands of + + align:start position:0% +might take thousands of + + + align:start position:0% +might take thousands of +uh positions of the extra source to + + align:start position:0% +uh positions of the extra source to + + + align:start position:0% +uh positions of the extra source to +construct this volume but here you may + + align:start position:0% +construct this volume but here you may + + + align:start position:0% +construct this volume but here you may +have just a few tons of cameras and also + + align:start position:0% +have just a few tons of cameras and also + + + align:start position:0% +have just a few tons of cameras and also +here you may have a full 180 degree + + align:start position:0% +here you may have a full 180 degree + + + align:start position:0% +here you may have a full 180 degree +rotation of your source and detectors + + align:start position:0% +rotation of your source and detectors + + + align:start position:0% +rotation of your source and detectors +but here you are only within your + + align:start position:0% +but here you are only within your + + + align:start position:0% +but here you are only within your +limited almost by the field of view and + + align:start position:0% +limited almost by the field of view and + + + align:start position:0% +limited almost by the field of view and +the + + align:start position:0% +the + + + align:start position:0% +the +arrangement of this camera which is + + align:start position:0% +arrangement of this camera which is + + + align:start position:0% +arrangement of this camera which is +so you might with respect to a given + + align:start position:0% +so you might with respect to a given + + + align:start position:0% +so you might with respect to a given +point you might only span + + align:start position:0% +point you might only span + + + align:start position:0% +point you might only span +say + + align:start position:0% +say + + + align:start position:0% +say +30 degrees or 40 degrees depending on + + align:start position:0% +30 degrees or 40 degrees depending on + + + align:start position:0% +30 degrees or 40 degrees depending on +the frequency + + align:start position:0% +the frequency + + + align:start position:0% +the frequency +and the distance + + align:start position:0% +and the distance + + + align:start position:0% +and the distance +so you could have a missing problem + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +those are of course just limitations in + + align:start position:0% +those are of course just limitations in + + + align:start position:0% +those are of course just limitations in +terms of + + align:start position:0% +terms of + + + align:start position:0% +terms of +the type of reconstruction you can + + align:start position:0% +the type of reconstruction you can + + + align:start position:0% +the type of reconstruction you can +achieve from nitrates but + + align:start position:0% +achieve from nitrates but + + + align:start position:0% +achieve from nitrates but +again in terms of math in terms of how + + align:start position:0% +again in terms of math in terms of how + + + align:start position:0% +again in terms of math in terms of how +you set up the system yes + + align:start position:0% + + + + align:start position:0% + +cool + + align:start position:0% +cool + + + align:start position:0% +cool +so that's why you can construct a + + align:start position:0% +so that's why you can construct a + + + align:start position:0% +so that's why you can construct a +tomography machine + + align:start position:0% +tomography machine + + + align:start position:0% +tomography machine +using the light field idea which we + + align:start position:0% +using the light field idea which we + + + align:start position:0% +using the light field idea which we +saw as shield field and hopefully we can + + align:start position:0% +saw as shield field and hopefully we can + + + align:start position:0% +saw as shield field and hopefully we can +convert various complex concepts of + + align:start position:0% +convert various complex concepts of + + + align:start position:0% +convert various complex concepts of +tomography and deconvolution + + align:start position:0% +tomography and deconvolution + + + align:start position:0% +tomography and deconvolution +and confocal imaging and all that + + align:start position:0% +and confocal imaging and all that + + + align:start position:0% +and confocal imaging and all that +and achieve them with + + align:start position:0% +and achieve them with + + + align:start position:0% +and achieve them with +principles that we're unfamiliar with in + + align:start position:0% +principles that we're unfamiliar with in + + + align:start position:0% +principles that we're unfamiliar with in +the visible spectrum with optics or + + align:start position:0% +the visible spectrum with optics or + + + align:start position:0% +the visible spectrum with optics or +without optics + + align:start position:0% +without optics + + + align:start position:0% +without optics +and + + align:start position:0% +and + + + align:start position:0% +and +make them available on possibly your + + align:start position:0% +make them available on possibly your + + + align:start position:0% +make them available on possibly your +surface cameras \ No newline at end of file diff --git a/xDKnMXtZKq8.txt b/xDKnMXtZKq8.txt new file mode 100644 index 0000000000000000000000000000000000000000..4a4f0ef3ddb49ebb5522f989825afb9f6441b93d --- /dev/null +++ b/xDKnMXtZKq8.txt @@ -0,0 +1,12595 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT OpenCourseWare continue to + + align:start position:0% +will help MIT OpenCourseWare continue to + + + align:start position:0% +will help MIT OpenCourseWare continue to +offer high quality educational resources + + align:start position:0% +offer high quality educational resources + + + align:start position:0% +offer high quality educational resources +for free + + align:start position:0% +for free + + + align:start position:0% +for free +to make a donation or to view additional + + align:start position:0% +to make a donation or to view additional + + + align:start position:0% +to make a donation or to view additional +materials from hundreds of MIT courses + + align:start position:0% +materials from hundreds of MIT courses + + + align:start position:0% +materials from hundreds of MIT courses +visit MIT opencourseware at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +all right so we've talked a little bit + + align:start position:0% +all right so we've talked a little bit + + + align:start position:0% +all right so we've talked a little bit +about caching before but today we're + + align:start position:0% +about caching before but today we're + + + align:start position:0% +about caching before but today we're +going to talk in much more detail about + + align:start position:0% +going to talk in much more detail about + + + align:start position:0% +going to talk in much more detail about +caching and how to design cache + + align:start position:0% +caching and how to design cache + + + align:start position:0% +caching and how to design cache +efficient algorithms so first let's look + + align:start position:0% +efficient algorithms so first let's look + + + align:start position:0% +efficient algorithms so first let's look +at the caching Hardware on modern + + align:start position:0% +at the caching Hardware on modern + + + align:start position:0% +at the caching Hardware on modern +machines today so here's what the cache + + align:start position:0% +machines today so here's what the cache + + + align:start position:0% +machines today so here's what the cache +hierarchy looks like for a multi-core + + align:start position:0% +hierarchy looks like for a multi-core + + + align:start position:0% +hierarchy looks like for a multi-core +chip we have a whole bunch of processors + + align:start position:0% +chip we have a whole bunch of processors + + + align:start position:0% +chip we have a whole bunch of processors +they're all they all have their own + + align:start position:0% +they're all they all have their own + + + align:start position:0% +they're all they all have their own +private l1 caches for both the data as + + align:start position:0% +private l1 caches for both the data as + + + align:start position:0% +private l1 caches for both the data as +well as the instruction they also have a + + align:start position:0% +well as the instruction they also have a + + + align:start position:0% +well as the instruction they also have a +private l2 cache and then they share a + + align:start position:0% +private l2 cache and then they share a + + + align:start position:0% +private l2 cache and then they share a +last level cache or l3 cache which is + + align:start position:0% +last level cache or l3 cache which is + + + align:start position:0% +last level cache or l3 cache which is +also called LLC they're all connected to + + align:start position:0% +also called LLC they're all connected to + + + align:start position:0% +also called LLC they're all connected to +a memory controller that can access DRAM + + align:start position:0% +a memory controller that can access DRAM + + + align:start position:0% +a memory controller that can access DRAM +and then oftentimes you'll have multiple + + align:start position:0% +and then oftentimes you'll have multiple + + + align:start position:0% +and then oftentimes you'll have multiple +chips on the same same server and these + + align:start position:0% +chips on the same same server and these + + + align:start position:0% +chips on the same same server and these +chips would be connected through a + + align:start position:0% +chips would be connected through a + + + align:start position:0% +chips would be connected through a +network so here we have a bunch of + + align:start position:0% +network so here we have a bunch of + + + align:start position:0% +network so here we have a bunch of +multi-core chips that are connected + + align:start position:0% +multi-core chips that are connected + + + align:start position:0% +multi-core chips that are connected +together so we can see that there are + + align:start position:0% +together so we can see that there are + + + align:start position:0% +together so we can see that there are +different levels of memory here and the + + align:start position:0% +different levels of memory here and the + + + align:start position:0% +different levels of memory here and the +sizes of each one of these levels of + + align:start position:0% +sizes of each one of these levels of + + + align:start position:0% +sizes of each one of these levels of +memory is different so the sizes tend to + + align:start position:0% +memory is different so the sizes tend to + + + align:start position:0% +memory is different so the sizes tend to +go up as you move up the memory + + align:start position:0% +go up as you move up the memory + + + align:start position:0% +go up as you move up the memory +hierarchy the l1 caches tend to be about + + align:start position:0% +hierarchy the l1 caches tend to be about + + + align:start position:0% +hierarchy the l1 caches tend to be about +32 kilobytes in fact these are the + + align:start position:0% +32 kilobytes in fact these are the + + + align:start position:0% +32 kilobytes in fact these are the +specifications for the machines that + + align:start position:0% +specifications for the machines that + + + align:start position:0% +specifications for the machines that +you're using in this class so 32 + + align:start position:0% +you're using in this class so 32 + + + align:start position:0% +you're using in this class so 32 +kilobytes for both the l1 data cache in + + align:start position:0% +kilobytes for both the l1 data cache in + + + align:start position:0% +kilobytes for both the l1 data cache in +the l1 instruction cache 256 kilobytes + + align:start position:0% +the l1 instruction cache 256 kilobytes + + + align:start position:0% +the l1 instruction cache 256 kilobytes +for the l2 cache so the l2 cache tends + + align:start position:0% +for the l2 cache so the l2 cache tends + + + align:start position:0% +for the l2 cache so the l2 cache tends +to be about 8 to 10 times larger than l1 + + align:start position:0% +to be about 8 to 10 times larger than l1 + + + align:start position:0% +to be about 8 to 10 times larger than l1 +cache and then the last level cache the + + align:start position:0% +cache and then the last level cache the + + + align:start position:0% +cache and then the last level cache the +size is 30 megabytes so this is + + align:start position:0% +size is 30 megabytes so this is + + + align:start position:0% +size is 30 megabytes so this is +typically on the order of tens of + + align:start position:0% +typically on the order of tens of + + + align:start position:0% +typically on the order of tens of +megabytes and then DRAM is on the order + + align:start position:0% +megabytes and then DRAM is on the order + + + align:start position:0% +megabytes and then DRAM is on the order +of Giga bytes so + + align:start position:0% +of Giga bytes so + + + align:start position:0% +of Giga bytes so +we have 128 gigabyte DRAM and nowadays + + align:start position:0% +we have 128 gigabyte DRAM and nowadays + + + align:start position:0% +we have 128 gigabyte DRAM and nowadays +you can actually get machines that have + + align:start position:0% +you can actually get machines that have + + + align:start position:0% +you can actually get machines that have +terabytes of DRAM so the associativity + + align:start position:0% +terabytes of DRAM so the associativity + + + align:start position:0% +terabytes of DRAM so the associativity +tends to go up as you move up the cache + + align:start position:0% +tends to go up as you move up the cache + + + align:start position:0% +tends to go up as you move up the cache +are key and I'll talk more about social + + align:start position:0% +are key and I'll talk more about social + + + align:start position:0% +are key and I'll talk more about social +scientific on the next couple slides the + + align:start position:0% +scientific on the next couple slides the + + + align:start position:0% +scientific on the next couple slides the +time to access the memory also tends to + + align:start position:0% +time to access the memory also tends to + + + align:start position:0% +time to access the memory also tends to +go up so the latency tends to go up as + + align:start position:0% +go up so the latency tends to go up as + + + align:start position:0% +go up so the latency tends to go up as +you move up the memory hierarchies so + + align:start position:0% +you move up the memory hierarchies so + + + align:start position:0% +you move up the memory hierarchies so +the l1 caches are the quickest to access + + align:start position:0% +the l1 caches are the quickest to access + + + align:start position:0% +the l1 caches are the quickest to access +so about 2 nanoseconds you're just rough + + align:start position:0% +so about 2 nanoseconds you're just rough + + + align:start position:0% +so about 2 nanoseconds you're just rough +numbers the l2 cache is a little bit + + align:start position:0% +numbers the l2 cache is a little bit + + + align:start position:0% +numbers the l2 cache is a little bit +slower so say for nanoseconds last level + + align:start position:0% +slower so say for nanoseconds last level + + + align:start position:0% +slower so say for nanoseconds last level +cache maybe 6 nanoseconds and then when + + align:start position:0% +cache maybe 6 nanoseconds and then when + + + align:start position:0% +cache maybe 6 nanoseconds and then when +you have to go to DRAM it's about an + + align:start position:0% +you have to go to DRAM it's about an + + + align:start position:0% +you have to go to DRAM it's about an +order of magnitude slower so 50 + + align:start position:0% +order of magnitude slower so 50 + + + align:start position:0% +order of magnitude slower so 50 +nanoseconds in this example and the + + align:start position:0% +nanoseconds in this example and the + + + align:start position:0% +nanoseconds in this example and the +reason why the memories are further down + + align:start position:0% +reason why the memories are further down + + + align:start position:0% +reason why the memories are further down +in the cache mark you're faster is + + align:start position:0% +in the cache mark you're faster is + + + align:start position:0% +in the cache mark you're faster is +because they're using more expensive + + align:start position:0% +because they're using more expensive + + + align:start position:0% +because they're using more expensive +materials to manufacture these things + + align:start position:0% +materials to manufacture these things + + + align:start position:0% +materials to manufacture these things +but since they tend to be more expensive + + align:start position:0% +but since they tend to be more expensive + + + align:start position:0% +but since they tend to be more expensive +we can't fit as much of that on the + + align:start position:0% +we can't fit as much of that on the + + + align:start position:0% +we can't fit as much of that on the +machines so that's why the faster + + align:start position:0% +machines so that's why the faster + + + align:start position:0% +machines so that's why the faster +memories are smaller than the slower + + align:start position:0% +memories are smaller than the slower + + + align:start position:0% +memories are smaller than the slower +memories but if we're able to take + + align:start position:0% +memories but if we're able to take + + + align:start position:0% +memories but if we're able to take +advantage of locality in our programs + + align:start position:0% +advantage of locality in our programs + + + align:start position:0% +advantage of locality in our programs +and we can make use of the fast memory + + align:start position:0% +and we can make use of the fast memory + + + align:start position:0% +and we can make use of the fast memory +as much as possible we'll talk about + + align:start position:0% +as much as possible we'll talk about + + + align:start position:0% +as much as possible we'll talk about +ways to do that in this lecture today + + align:start position:0% +ways to do that in this lecture today + + + align:start position:0% +ways to do that in this lecture today +there's also the latency across the + + align:start position:0% +there's also the latency across the + + + align:start position:0% +there's also the latency across the +network which tends to be cheaper than + + align:start position:0% +network which tends to be cheaper than + + + align:start position:0% +network which tends to be cheaper than +going to main memory but slower than + + align:start position:0% +going to main memory but slower than + + + align:start position:0% +going to main memory but slower than +doing a last level cache access and + + align:start position:0% +doing a last level cache access and + + + align:start position:0% +doing a last level cache access and +there's a lot of work in trying to get + + align:start position:0% +there's a lot of work in trying to get + + + align:start position:0% +there's a lot of work in trying to get +the cache coherence protocols right as + + align:start position:0% +the cache coherence protocols right as + + + align:start position:0% +the cache coherence protocols right as +we mentioned before so since these + + align:start position:0% +we mentioned before so since these + + + align:start position:0% +we mentioned before so since these +processors all have private caches we + + align:start position:0% +processors all have private caches we + + + align:start position:0% +processors all have private caches we +need to make sure that they all see a + + align:start position:0% +need to make sure that they all see a + + + align:start position:0% +need to make sure that they all see a +consistent view of memory when they're + + align:start position:0% +consistent view of memory when they're + + + align:start position:0% +consistent view of memory when they're +trying to access the same memory + + align:start position:0% +trying to access the same memory + + + align:start position:0% +trying to access the same memory +addresses in parallel so we talked about + + align:start position:0% +addresses in parallel so we talked about + + + align:start position:0% +addresses in parallel so we talked about +the MSI cache protocol before and there + + align:start position:0% +the MSI cache protocol before and there + + + align:start position:0% +the MSI cache protocol before and there +are many other protocols out there and + + align:start position:0% +are many other protocols out there and + + + align:start position:0% +are many other protocols out there and +you can read more about these things + + align:start position:0% +you can read more about these things + + + align:start position:0% +you can read more about these things +online but these are very hard to get + + align:start position:0% +online but these are very hard to get + + + align:start position:0% +online but these are very hard to get +right and there's a lot of verification + + align:start position:0% +right and there's a lot of verification + + + align:start position:0% +right and there's a lot of verification +involved in trying to prove that the + + align:start position:0% +involved in trying to prove that the + + + align:start position:0% +involved in trying to prove that the +cache coherence protocols are correct + + align:start position:0% + + + + align:start position:0% + +so any questions so far okay so let's + + align:start position:0% +so any questions so far okay so let's + + + align:start position:0% +so any questions so far okay so let's +talk about the associativity of a cache + + align:start position:0% +talk about the associativity of a cache + + + align:start position:0% +talk about the associativity of a cache +so here I'm showing you a fully + + align:start position:0% +so here I'm showing you a fully + + + align:start position:0% +so here I'm showing you a fully +associative cache and in a fully + + align:start position:0% +associative cache and in a fully + + + align:start position:0% +associative cache and in a fully +associative cache a cache block can + + align:start position:0% +associative cache a cache block can + + + align:start position:0% +associative cache a cache block can +reside anywhere in the cache and the + + align:start position:0% +reside anywhere in the cache and the + + + align:start position:0% +reside anywhere in the cache and the +basic unit of movement here is a cache + + align:start position:0% +basic unit of movement here is a cache + + + align:start position:0% +basic unit of movement here is a cache +block in this example the cache block + + align:start position:0% +block in this example the cache block + + + align:start position:0% +block in this example the cache block +size is 4 bytes but on the on the + + align:start position:0% +size is 4 bytes but on the on the + + + align:start position:0% +size is 4 bytes but on the on the +machines that we're using for this class + + align:start position:0% +machines that we're using for this class + + + align:start position:0% +machines that we're using for this class +the cache block size is 64 bytes but for + + align:start position:0% +the cache block size is 64 bytes but for + + + align:start position:0% +the cache block size is 64 bytes but for +this example I'm going to use a 4 byte + + align:start position:0% +this example I'm going to use a 4 byte + + + align:start position:0% +this example I'm going to use a 4 byte +cache line so each row here corresponds + + align:start position:0% +cache line so each row here corresponds + + + align:start position:0% +cache line so each row here corresponds +to one cache line in a fully associative + + align:start position:0% +to one cache line in a fully associative + + + align:start position:0% +to one cache line in a fully associative +cache means that each line here can go + + align:start position:0% +cache means that each line here can go + + + align:start position:0% +cache means that each line here can go +anywhere in the cache and then here + + align:start position:0% +anywhere in the cache and then here + + + align:start position:0% +anywhere in the cache and then here +we're also assuming a cache size that + + align:start position:0% +we're also assuming a cache size that + + + align:start position:0% +we're also assuming a cache size that +has 32 bytes so in total it can store a + + align:start position:0% +has 32 bytes so in total it can store a + + + align:start position:0% +has 32 bytes so in total it can store a +cache lines since the cache line is 4 + + align:start position:0% +cache lines since the cache line is 4 + + + align:start position:0% +cache lines since the cache line is 4 +bytes so to find a block in a fully + + align:start position:0% +bytes so to find a block in a fully + + + align:start position:0% +bytes so to find a block in a fully +associative cache you have to actually + + align:start position:0% +associative cache you have to actually + + + align:start position:0% +associative cache you have to actually +search the entire cache because a cache + + align:start position:0% +search the entire cache because a cache + + + align:start position:0% +search the entire cache because a cache +line can appear anywhere in the cache + + align:start position:0% +line can appear anywhere in the cache + + + align:start position:0% +line can appear anywhere in the cache +and there's a tag associated with each + + align:start position:0% +and there's a tag associated with each + + + align:start position:0% +and there's a tag associated with each +of these cache lines here that that + + align:start position:0% +of these cache lines here that that + + + align:start position:0% +of these cache lines here that that +basically specify which of the memory + + align:start position:0% +basically specify which of the memory + + + align:start position:0% +basically specify which of the memory +addresses in virtual memory space it + + align:start position:0% +addresses in virtual memory space it + + + align:start position:0% +addresses in virtual memory space it +corresponds to so for the fully + + align:start position:0% +corresponds to so for the fully + + + align:start position:0% +corresponds to so for the fully +associative cache we're actually gonna + + align:start position:0% +associative cache we're actually gonna + + + align:start position:0% +associative cache we're actually gonna +use most of the bits of the address as a + + align:start position:0% +use most of the bits of the address as a + + + align:start position:0% +use most of the bits of the address as a +tag we don't actually need the two lower + + align:start position:0% +tag we don't actually need the two lower + + + align:start position:0% +tag we don't actually need the two lower +order bits because the things are being + + align:start position:0% +order bits because the things are being + + + align:start position:0% +order bits because the things are being +moved that degree and the granularity of + + align:start position:0% +moved that degree and the granularity of + + + align:start position:0% +moved that degree and the granularity of +cache lines which are 4 bytes so the two + + align:start position:0% +cache lines which are 4 bytes so the two + + + align:start position:0% +cache lines which are 4 bytes so the two +lower order bits are always going to be + + align:start position:0% +lower order bits are always going to be + + + align:start position:0% +lower order bits are always going to be +the same but we're just gonna use the + + align:start position:0% +the same but we're just gonna use the + + + align:start position:0% +the same but we're just gonna use the +rest of the bits to store the tag so if + + align:start position:0% +rest of the bits to store the tag so if + + + align:start position:0% +rest of the bits to store the tag so if +our address space is 64 bits then we're + + align:start position:0% +our address space is 64 bits then we're + + + align:start position:0% +our address space is 64 bits then we're +gonna use 62 bits to store the tag in a + + align:start position:0% +gonna use 62 bits to store the tag in a + + + align:start position:0% +gonna use 62 bits to store the tag in a +fully associative cache in scheme and + + align:start position:0% +fully associative cache in scheme and + + + align:start position:0% +fully associative cache in scheme and +when a cache becomes full a block that + + align:start position:0% +when a cache becomes full a block that + + + align:start position:0% +when a cache becomes full a block that +has to be victim a chrome for a new + + align:start position:0% +has to be victim a chrome for a new + + + align:start position:0% +has to be victim a chrome for a new +block and there are various ways that + + align:start position:0% +block and there are various ways that + + + align:start position:0% +block and there are various ways that +you can decide how to evict a block so + + align:start position:0% +you can decide how to evict a block so + + + align:start position:0% +you can decide how to evict a block so +this is known as the replacement policy + + align:start position:0% +this is known as the replacement policy + + + align:start position:0% +this is known as the replacement policy +one common replacement policy is LRU or + + align:start position:0% +one common replacement policy is LRU or + + + align:start position:0% +one common replacement policy is LRU or +least recently used + + align:start position:0% +least recently used + + + align:start position:0% +least recently used +so you basically kick the thing out that + + align:start position:0% +so you basically kick the thing out that + + + align:start position:0% +so you basically kick the thing out that +has been used the farthest in the past + + align:start position:0% +has been used the farthest in the past + + + align:start position:0% +has been used the farthest in the past +dollar schemes such as second chance and + + align:start position:0% +dollar schemes such as second chance and + + + align:start position:0% +dollar schemes such as second chance and +clock replacement we're not going to + + align:start position:0% +clock replacement we're not going to + + + align:start position:0% +clock replacement we're not going to +talk too much about the different + + align:start position:0% +talk too much about the different + + + align:start position:0% +talk too much about the different +replacement schemes today but you can + + align:start position:0% +replacement schemes today but you can + + + align:start position:0% +replacement schemes today but you can +feel free to read about these things + + align:start position:0% +feel free to read about these things + + + align:start position:0% +feel free to read about these things +online so what's a disadvantage of this + + align:start position:0% +online so what's a disadvantage of this + + + align:start position:0% +online so what's a disadvantage of this +scheme + + align:start position:0% + + + + align:start position:0% + +yes yeah why is it slow + + align:start position:0% + + + + align:start position:0% + +yeah so so the disadvantage is that + + align:start position:0% +yeah so so the disadvantage is that + + + align:start position:0% +yeah so so the disadvantage is that +searching for a cache line in the cache + + align:start position:0% +searching for a cache line in the cache + + + align:start position:0% +searching for a cache line in the cache +can be pretty slow because you have to + + align:start position:0% +can be pretty slow because you have to + + + align:start position:0% +can be pretty slow because you have to +search the entire cache in the worst + + align:start position:0% +search the entire cache in the worst + + + align:start position:0% +search the entire cache in the worst +case since a cache block can reside + + align:start position:0% +case since a cache block can reside + + + align:start position:0% +case since a cache block can reside +anywhere in the cache so even though the + + align:start position:0% +anywhere in the cache so even though the + + + align:start position:0% +anywhere in the cache so even though the +search can go on in parallel and + + align:start position:0% +search can go on in parallel and + + + align:start position:0% +search can go on in parallel and +hardware still expensive in terms of + + align:start position:0% +hardware still expensive in terms of + + + align:start position:0% +hardware still expensive in terms of +power and performance to have to search + + align:start position:0% +power and performance to have to search + + + align:start position:0% +power and performance to have to search +most of the cache every time so let's + + align:start position:0% +most of the cache every time so let's + + + align:start position:0% +most of the cache every time so let's +look at another extreme this is a direct + + align:start position:0% +look at another extreme this is a direct + + + align:start position:0% +look at another extreme this is a direct +mapped cache so in a direct mapped cache + + align:start position:0% +mapped cache so in a direct mapped cache + + + align:start position:0% +mapped cache so in a direct mapped cache +each cache block can only go in one + + align:start position:0% +each cache block can only go in one + + + align:start position:0% +each cache block can only go in one +place in the cache so I've color-coded + + align:start position:0% +place in the cache so I've color-coded + + + align:start position:0% +place in the cache so I've color-coded +these cache blocks here so the red + + align:start position:0% +these cache blocks here so the red + + + align:start position:0% +these cache blocks here so the red +blocks can only go in the first row of + + align:start position:0% +blocks can only go in the first row of + + + align:start position:0% +blocks can only go in the first row of +this cache the orange ones can only go + + align:start position:0% +this cache the orange ones can only go + + + align:start position:0% +this cache the orange ones can only go +in the second row and so on and the + + align:start position:0% +in the second row and so on and the + + + align:start position:0% +in the second row and so on and the +position which cache block can go into + + align:start position:0% +position which cache block can go into + + + align:start position:0% +position which cache block can go into +is known as that cache blocks set so the + + align:start position:0% +is known as that cache blocks set so the + + + align:start position:0% +is known as that cache blocks set so the +set determines the location in the cache + + align:start position:0% +set determines the location in the cache + + + align:start position:0% +set determines the location in the cache +for each particular block so let's look + + align:start position:0% +for each particular block so let's look + + + align:start position:0% +for each particular block so let's look +at how the virtual memory address is + + align:start position:0% +at how the virtual memory address is + + + align:start position:0% +at how the virtual memory address is +divided up into and which of the bits + + align:start position:0% +divided up into and which of the bits + + + align:start position:0% +divided up into and which of the bits +we're gonna use to figure out where a + + align:start position:0% +we're gonna use to figure out where a + + + align:start position:0% +we're gonna use to figure out where a +cache block should go in the cache so we + + align:start position:0% +cache block should go in the cache so we + + + align:start position:0% +cache block should go in the cache so we +have the offset we have the set and then + + align:start position:0% +have the offset we have the set and then + + + align:start position:0% +have the offset we have the set and then +the tag fields the offset just tells us + + align:start position:0% +the tag fields the offset just tells us + + + align:start position:0% +the tag fields the offset just tells us +which position we want to access within + + align:start position:0% +which position we want to access within + + + align:start position:0% +which position we want to access within +a cache block so since a cache block has + + align:start position:0% +a cache block so since a cache block has + + + align:start position:0% +a cache block so since a cache block has +B bytes we only need log base two of B + + align:start position:0% +B bytes we only need log base two of B + + + align:start position:0% +B bytes we only need log base two of B +bits that's offset and the reason why we + + align:start position:0% +bits that's offset and the reason why we + + + align:start position:0% +bits that's offset and the reason why we +have to also is because we're not always + + align:start position:0% +have to also is because we're not always + + + align:start position:0% +have to also is because we're not always +accessing something at the beginning of + + align:start position:0% +accessing something at the beginning of + + + align:start position:0% +accessing something at the beginning of +a cache block we might want to access + + align:start position:0% +a cache block we might want to access + + + align:start position:0% +a cache block we might want to access +something in the middle and that's why + + align:start position:0% +something in the middle and that's why + + + align:start position:0% +something in the middle and that's why +we need to offset to specify where in + + align:start position:0% +we need to offset to specify where in + + + align:start position:0% +we need to offset to specify where in +the cache block we want to access then + + align:start position:0% +the cache block we want to access then + + + align:start position:0% +the cache block we want to access then +there's a set field and the set field is + + align:start position:0% +there's a set field and the set field is + + + align:start position:0% +there's a set field and the set field is +going to determine which position in the + + align:start position:0% +going to determine which position in the + + + align:start position:0% +going to determine which position in the +cache that cache block can go into so + + align:start position:0% +cache that cache block can go into so + + + align:start position:0% +cache that cache block can go into so +there are eight possible positions for + + align:start position:0% +there are eight possible positions for + + + align:start position:0% +there are eight possible positions for +each cache block here and therefore we + + align:start position:0% +each cache block here and therefore we + + + align:start position:0% +each cache block here and therefore we +only need log base two of eight bits so + + align:start position:0% +only need log base two of eight bits so + + + align:start position:0% +only need log base two of eight bits so +three bits for the set in this example + + align:start position:0% +three bits for the set in this example + + + align:start position:0% +three bits for the set in this example +and more generally it's going to be log + + align:start position:0% +and more generally it's going to be log + + + align:start position:0% +and more generally it's going to be log +base 2 of M over B and here M over B is + + align:start position:0% +base 2 of M over B and here M over B is + + + align:start position:0% +base 2 of M over B and here M over B is +eight + + align:start position:0% +eight + + + align:start position:0% +eight +and then finally we're gonna use the + + align:start position:0% +and then finally we're gonna use the + + + align:start position:0% +and then finally we're gonna use the +remaining bits as a tag so W minus log + + align:start position:0% +remaining bits as a tag so W minus log + + + align:start position:0% +remaining bits as a tag so W minus log +base 2 of M bits for the tag and that + + align:start position:0% +base 2 of M bits for the tag and that + + + align:start position:0% +base 2 of M bits for the tag and that +gets stored along with the cache block + + align:start position:0% +gets stored along with the cache block + + + align:start position:0% +gets stored along with the cache block +in the cache and that's going to + + align:start position:0% +in the cache and that's going to + + + align:start position:0% +in the cache and that's going to +uniquely identify which of the which of + + align:start position:0% +uniquely identify which of the which of + + + align:start position:0% +uniquely identify which of the which of +the memory blocks the the cache block + + align:start position:0% +the memory blocks the the cache block + + + align:start position:0% +the memory blocks the the cache block +corresponds to in virtual memory and you + + align:start position:0% +corresponds to in virtual memory and you + + + align:start position:0% +corresponds to in virtual memory and you +can verify that the sum of all of these + + align:start position:0% +can verify that the sum of all of these + + + align:start position:0% +can verify that the sum of all of these +quantities here sums to W bits so in + + align:start position:0% +quantities here sums to W bits so in + + + align:start position:0% +quantities here sums to W bits so in +total we have a W bit address space and + + align:start position:0% +total we have a W bit address space and + + + align:start position:0% +total we have a W bit address space and +the sum of those three things is W so + + align:start position:0% +the sum of those three things is W so + + + align:start position:0% +the sum of those three things is W so +what's the advantage and disadvantage of + + align:start position:0% +what's the advantage and disadvantage of + + + align:start position:0% +what's the advantage and disadvantage of +this scheme + + align:start position:0% + + + + align:start position:0% + +so first what's the what's a good thing + + align:start position:0% +so first what's the what's a good thing + + + align:start position:0% +so first what's the what's a good thing +about this scheme compared to the + + align:start position:0% +about this scheme compared to the + + + align:start position:0% +about this scheme compared to the +previous scheme that we saw yes yes fast + + align:start position:0% +previous scheme that we saw yes yes fast + + + align:start position:0% +previous scheme that we saw yes yes fast +because you only have to check one place + + align:start position:0% +because you only have to check one place + + + align:start position:0% +because you only have to check one place +because each cache block can only go in + + align:start position:0% +because each cache block can only go in + + + align:start position:0% +because each cache block can only go in +one place in the cache and that's the + + align:start position:0% +one place in the cache and that's the + + + align:start position:0% +one place in the cache and that's the +only place you have to check when you + + align:start position:0% +only place you have to check when you + + + align:start position:0% +only place you have to check when you +try to do a lookup if the cache block is + + align:start position:0% +try to do a lookup if the cache block is + + + align:start position:0% +try to do a lookup if the cache block is +there then you find it if it's not then + + align:start position:0% +there then you find it if it's not then + + + align:start position:0% +there then you find it if it's not then +you know it's not in the cache what's + + align:start position:0% +you know it's not in the cache what's + + + align:start position:0% +you know it's not in the cache what's +the downside to this scheme yeah yeah so + + align:start position:0% +the downside to this scheme yeah yeah so + + + align:start position:0% +the downside to this scheme yeah yeah so +it's a good answer so the downside is + + align:start position:0% +it's a good answer so the downside is + + + align:start position:0% +it's a good answer so the downside is +that you might for example or just be + + align:start position:0% +that you might for example or just be + + + align:start position:0% +that you might for example or just be +accessing the rad cache blocks and then + + align:start position:0% +accessing the rad cache blocks and then + + + align:start position:0% +accessing the rad cache blocks and then +not accessing any of the other cache + + align:start position:0% +not accessing any of the other cache + + + align:start position:0% +not accessing any of the other cache +blocks they'll all get mapped to the + + align:start position:0% +blocks they'll all get mapped to the + + + align:start position:0% +blocks they'll all get mapped to the +same location in the cache and then + + align:start position:0% +same location in the cache and then + + + align:start position:0% +same location in the cache and then +they'll keep keep evicting each other + + align:start position:0% +they'll keep keep evicting each other + + + align:start position:0% +they'll keep keep evicting each other +even though there's a lot of empty space + + align:start position:0% +even though there's a lot of empty space + + + align:start position:0% +even though there's a lot of empty space +in the cache and this is known as a + + align:start position:0% +in the cache and this is known as a + + + align:start position:0% +in the cache and this is known as a +conflict miss and these can be very bad + + align:start position:0% +conflict miss and these can be very bad + + + align:start position:0% +conflict miss and these can be very bad +for performance and very hard to debug + + align:start position:0% +for performance and very hard to debug + + + align:start position:0% +for performance and very hard to debug +so that's one downside of a direct + + align:start position:0% +so that's one downside of a direct + + + align:start position:0% +so that's one downside of a direct +mapped cache is that you can get these + + align:start position:0% +mapped cache is that you can get these + + + align:start position:0% +mapped cache is that you can get these +conflict misses where you have to evict + + align:start position:0% +conflict misses where you have to evict + + + align:start position:0% +conflict misses where you have to evict +things from the cache even though + + align:start position:0% +things from the cache even though + + + align:start position:0% +things from the cache even though +there's empty space in the cache so as + + align:start position:0% +there's empty space in the cache so as + + + align:start position:0% +there's empty space in the cache so as +we said finding a block is very fast + + align:start position:0% +we said finding a block is very fast + + + align:start position:0% +we said finding a block is very fast +only a single location in the cache has + + align:start position:0% +only a single location in the cache has + + + align:start position:0% +only a single location in the cache has +to be searched but you might suffer from + + align:start position:0% +to be searched but you might suffer from + + + align:start position:0% +to be searched but you might suffer from +conflict misses if you keep accessing + + align:start position:0% +conflict misses if you keep accessing + + + align:start position:0% +conflict misses if you keep accessing +things in the same set repeatedly + + align:start position:0% +things in the same set repeatedly + + + align:start position:0% +things in the same set repeatedly +without accessing the things and the + + align:start position:0% +without accessing the things and the + + + align:start position:0% +without accessing the things and the +other sets so any questions + + align:start position:0% + + + + align:start position:0% + +okay so these are sort of the two + + align:start position:0% +okay so these are sort of the two + + + align:start position:0% +okay so these are sort of the two +extremes for cash design there's + + align:start position:0% +extremes for cash design there's + + + align:start position:0% +extremes for cash design there's +actually a hybrid solution called set + + align:start position:0% +actually a hybrid solution called set + + + align:start position:0% +actually a hybrid solution called set +associative cache and in a set + + align:start position:0% +associative cache and in a set + + + align:start position:0% +associative cache and in a set +associative cache you still have sets + + align:start position:0% +associative cache you still have sets + + + align:start position:0% +associative cache you still have sets +but each of the sets contains more than + + align:start position:0% +but each of the sets contains more than + + + align:start position:0% +but each of the sets contains more than +one line now so all the red blocks still + + align:start position:0% +one line now so all the red blocks still + + + align:start position:0% +one line now so all the red blocks still +map to the red set but there's actually + + align:start position:0% +map to the red set but there's actually + + + align:start position:0% +map to the red set but there's actually +two possible locations for the red + + align:start position:0% +two possible locations for the red + + + align:start position:0% +two possible locations for the red +blocks now so in this case this is known + + align:start position:0% +blocks now so in this case this is known + + + align:start position:0% +blocks now so in this case this is known +as a 2-way associative cache since there + + align:start position:0% +as a 2-way associative cache since there + + + align:start position:0% +as a 2-way associative cache since there +are two possible locations inside each + + align:start position:0% +are two possible locations inside each + + + align:start position:0% +are two possible locations inside each +set and again a cache blocks set + + align:start position:0% +set and again a cache blocks set + + + align:start position:0% +set and again a cache blocks set +determines K possible cache locations + + align:start position:0% +determines K possible cache locations + + + align:start position:0% +determines K possible cache locations +for that block so within a set it's + + align:start position:0% +for that block so within a set it's + + + align:start position:0% +for that block so within a set it's +fully associative but each block can + + align:start position:0% +fully associative but each block can + + + align:start position:0% +fully associative but each block can +only go in one of the sets so let's look + + align:start position:0% +only go in one of the sets so let's look + + + align:start position:0% +only go in one of the sets so let's look +again at how the bits are divided into + + align:start position:0% +again at how the bits are divided into + + + align:start position:0% +again at how the bits are divided into +in the address so we still have the tag + + align:start position:0% +in the address so we still have the tag + + + align:start position:0% +in the address so we still have the tag +set and offset fields the offset field + + align:start position:0% +set and offset fields the offset field + + + align:start position:0% +set and offset fields the offset field +is still log base 2 of B the set field + + align:start position:0% +is still log base 2 of B the set field + + + align:start position:0% +is still log base 2 of B the set field +is going to take log base 2 of M over KB + + align:start position:0% +is going to take log base 2 of M over KB + + + align:start position:0% +is going to take log base 2 of M over KB +bits so the number of sets we have is M + + align:start position:0% +bits so the number of sets we have is M + + + align:start position:0% +bits so the number of sets we have is M +over KB so we need log base 2 of that + + align:start position:0% +over KB so we need log base 2 of that + + + align:start position:0% +over KB so we need log base 2 of that +that number to represent the set of a + + align:start position:0% +that number to represent the set of a + + + align:start position:0% +that number to represent the set of a +block and then finally we use the + + align:start position:0% +block and then finally we use the + + + align:start position:0% +block and then finally we use the +remaining bits as a tag so it's going to + + align:start position:0% +remaining bits as a tag so it's going to + + + align:start position:0% +remaining bits as a tag so it's going to +be W minus log base 2 of M over K and + + align:start position:0% +be W minus log base 2 of M over K and + + + align:start position:0% +be W minus log base 2 of M over K and +now to find a block in the cache only K + + align:start position:0% +now to find a block in the cache only K + + + align:start position:0% +now to find a block in the cache only K +locations of the of its set must be + + align:start position:0% +locations of the of its set must be + + + align:start position:0% +locations of the of its set must be +searched + + align:start position:0% +searched + + + align:start position:0% +searched +so you basically find which set the + + align:start position:0% +so you basically find which set the + + + align:start position:0% +so you basically find which set the +cache block maps to and then you check + + align:start position:0% +cache block maps to and then you check + + + align:start position:0% +cache block maps to and then you check +all K locations within that set to see + + align:start position:0% +all K locations within that set to see + + + align:start position:0% +all K locations within that set to see +if that cache block is there and + + align:start position:0% +if that cache block is there and + + + align:start position:0% +if that cache block is there and +whenever you want to whenever you try to + + align:start position:0% +whenever you want to whenever you try to + + + align:start position:0% +whenever you want to whenever you try to +put something in the cache because it's + + align:start position:0% +put something in the cache because it's + + + align:start position:0% +put something in the cache because it's +not there you have to evict something + + align:start position:0% +not there you have to evict something + + + align:start position:0% +not there you have to evict something +and you've X something from the same set + + align:start position:0% +and you've X something from the same set + + + align:start position:0% +and you've X something from the same set +as the block that you're placing into + + align:start position:0% +as the block that you're placing into + + + align:start position:0% +as the block that you're placing into +the cache so for this example I showed a + + align:start position:0% +the cache so for this example I showed a + + + align:start position:0% +the cache so for this example I showed a +2-way associative cache but in practice + + align:start position:0% +2-way associative cache but in practice + + + align:start position:0% +2-way associative cache but in practice +the associativity is usually bigger say + + align:start position:0% +the associativity is usually bigger say + + + align:start position:0% +the associativity is usually bigger say +8 Way 16 way or sometimes 20 way and and + + align:start position:0% +8 Way 16 way or sometimes 20 way and and + + + align:start position:0% +8 Way 16 way or sometimes 20 way and and +as + + align:start position:0% +as + + + align:start position:0% +as +you keep increasing the associativity it + + align:start position:0% +you keep increasing the associativity it + + + align:start position:0% +you keep increasing the associativity it +looks it's gonna look more and more like + + align:start position:0% +looks it's gonna look more and more like + + + align:start position:0% +looks it's gonna look more and more like +a fully associative cache and if you + + align:start position:0% +a fully associative cache and if you + + + align:start position:0% +a fully associative cache and if you +have a one-way associative cache then + + align:start position:0% +have a one-way associative cache then + + + align:start position:0% +have a one-way associative cache then +it's just a direct mapped cache so this + + align:start position:0% +it's just a direct mapped cache so this + + + align:start position:0% +it's just a direct mapped cache so this +is a sort of a hybrid in-between a fully + + align:start position:0% +is a sort of a hybrid in-between a fully + + + align:start position:0% +is a sort of a hybrid in-between a fully +mapped cache and a fully associative + + align:start position:0% +mapped cache and a fully associative + + + align:start position:0% +mapped cache and a fully associative +cache in a direct mapped cache so any + + align:start position:0% +cache in a direct mapped cache so any + + + align:start position:0% +cache in a direct mapped cache so any +questions on set associative caches okay + + align:start position:0% +questions on set associative caches okay + + + align:start position:0% +questions on set associative caches okay +so let's go over a taxonomy of different + + align:start position:0% +so let's go over a taxonomy of different + + + align:start position:0% +so let's go over a taxonomy of different +types of cache misses that you can incur + + align:start position:0% +types of cache misses that you can incur + + + align:start position:0% +types of cache misses that you can incur +so the first type of cache miss is + + align:start position:0% +so the first type of cache miss is + + + align:start position:0% +so the first type of cache miss is +called a cold miss and this is a cache + + align:start position:0% +called a cold miss and this is a cache + + + align:start position:0% +called a cold miss and this is a cache +miss that you have to incur the first + + align:start position:0% +miss that you have to incur the first + + + align:start position:0% +miss that you have to incur the first +time you access a cache block and if you + + align:start position:0% +time you access a cache block and if you + + + align:start position:0% +time you access a cache block and if you +need to access this piece of data + + align:start position:0% +need to access this piece of data + + + align:start position:0% +need to access this piece of data +there's no way to get around getting a + + align:start position:0% +there's no way to get around getting a + + + align:start position:0% +there's no way to get around getting a +cold miss for this because your as cache + + align:start position:0% +cold miss for this because your as cache + + + align:start position:0% +cold miss for this because your as cache +starts out not having this block and the + + align:start position:0% +starts out not having this block and the + + + align:start position:0% +starts out not having this block and the +first time you access it you have to + + align:start position:0% +first time you access it you have to + + + align:start position:0% +first time you access it you have to +bring it into cache + + align:start position:0% +bring it into cache + + + align:start position:0% +bring it into cache +then there are capacity misses so + + align:start position:0% +then there are capacity misses so + + + align:start position:0% +then there are capacity misses so +capacity misses our cache misses you get + + align:start position:0% +capacity misses our cache misses you get + + + align:start position:0% +capacity misses our cache misses you get +because the cache is full and it can't + + align:start position:0% +because the cache is full and it can't + + + align:start position:0% +because the cache is full and it can't +fit all of the cache blocks that you + + align:start position:0% +fit all of the cache blocks that you + + + align:start position:0% +fit all of the cache blocks that you +want to access so you get a capacity + + align:start position:0% +want to access so you get a capacity + + + align:start position:0% +want to access so you get a capacity +miss when the previous cache copy would + + align:start position:0% +miss when the previous cache copy would + + + align:start position:0% +miss when the previous cache copy would +have been you victim 'van with a fully + + align:start position:0% +have been you victim 'van with a fully + + + align:start position:0% +have been you victim 'van with a fully +associative scheme so even if all of the + + align:start position:0% +associative scheme so even if all of the + + + align:start position:0% +associative scheme so even if all of the +possible locations in your cache could + + align:start position:0% +possible locations in your cache could + + + align:start position:0% +possible locations in your cache could +be used for a particular cache line that + + align:start position:0% +be used for a particular cache line that + + + align:start position:0% +be used for a particular cache line that +cache line still has to be evicted + + align:start position:0% +cache line still has to be evicted + + + align:start position:0% +cache line still has to be evicted +because there's not enough space so + + align:start position:0% +because there's not enough space so + + + align:start position:0% +because there's not enough space so +that's what's called a capacity miss and + + align:start position:0% +that's what's called a capacity miss and + + + align:start position:0% +that's what's called a capacity miss and +you can deal with capacity misses by + + align:start position:0% +you can deal with capacity misses by + + + align:start position:0% +you can deal with capacity misses by +introducing more locality into your code + + align:start position:0% +introducing more locality into your code + + + align:start position:0% +introducing more locality into your code +both spatial in temporal locality and + + align:start position:0% +both spatial in temporal locality and + + + align:start position:0% +both spatial in temporal locality and +we'll look at ways to reduce the + + align:start position:0% +we'll look at ways to reduce the + + + align:start position:0% +we'll look at ways to reduce the +capacity misses of algorithms later on + + align:start position:0% +capacity misses of algorithms later on + + + align:start position:0% +capacity misses of algorithms later on +in this lecture then Darr conflict + + align:start position:0% +in this lecture then Darr conflict + + + align:start position:0% +in this lecture then Darr conflict +misses and conflict misses happen in a + + align:start position:0% +misses and conflict misses happen in a + + + align:start position:0% +misses and conflict misses happen in a +set associative caches when you have too + + align:start position:0% +set associative caches when you have too + + + align:start position:0% +set associative caches when you have too +many blocks from the same set mapping to + + align:start position:0% +many blocks from the same set mapping to + + + align:start position:0% +many blocks from the same set mapping to +the wanting to go into the cache and + + align:start position:0% +the wanting to go into the cache and + + + align:start position:0% +the wanting to go into the cache and +some of these have to be evicted because + + align:start position:0% +some of these have to be evicted because + + + align:start position:0% +some of these have to be evicted because +the sack can't fit all of the blocks and + + align:start position:0% +the sack can't fit all of the blocks and + + + align:start position:0% +the sack can't fit all of the blocks and +these blocks wouldn't have been you + + align:start position:0% +these blocks wouldn't have been you + + + align:start position:0% +these blocks wouldn't have been you +Victor do had a fully associative + + align:start position:0% +Victor do had a fully associative + + + align:start position:0% +Victor do had a fully associative +schemes + + align:start position:0% +schemes + + + align:start position:0% +schemes +these are what's called conflict misses + + align:start position:0% +these are what's called conflict misses + + + align:start position:0% +these are what's called conflict misses +you have to for example if you have 16 + + align:start position:0% +you have to for example if you have 16 + + + align:start position:0% +you have to for example if you have 16 +things in a set and you keep accessing + + align:start position:0% +things in a set and you keep accessing + + + align:start position:0% +things in a set and you keep accessing +17 things that all belong in the set + + align:start position:0% +17 things that all belong in the set + + + align:start position:0% +17 things that all belong in the set +something's gonna get kicked out every + + align:start position:0% +something's gonna get kicked out every + + + align:start position:0% +something's gonna get kicked out every +time you want to access something and + + align:start position:0% +time you want to access something and + + + align:start position:0% +time you want to access something and +these cache evictions might not have + + align:start position:0% +these cache evictions might not have + + + align:start position:0% +these cache evictions might not have +happened if you had a fully associative + + align:start position:0% +happened if you had a fully associative + + + align:start position:0% +happened if you had a fully associative +cache and then finally there are sharing + + align:start position:0% +cache and then finally there are sharing + + + align:start position:0% +cache and then finally there are sharing +misses so sharing misses only happened + + align:start position:0% +misses so sharing misses only happened + + + align:start position:0% +misses so sharing misses only happened +in a parallel context and we talked a + + align:start position:0% +in a parallel context and we talked a + + + align:start position:0% +in a parallel context and we talked a +little bit about - sharing a false + + align:start position:0% +little bit about - sharing a false + + + align:start position:0% +little bit about - sharing a false +sharing misses in Prior lectures so + + align:start position:0% +sharing misses in Prior lectures so + + + align:start position:0% +sharing misses in Prior lectures so +let's just review this briefly so + + align:start position:0% +let's just review this briefly so + + + align:start position:0% +let's just review this briefly so +sharing this can happen if multiple + + align:start position:0% +sharing this can happen if multiple + + + align:start position:0% +sharing this can happen if multiple +processors are accessing the same cache + + align:start position:0% +processors are accessing the same cache + + + align:start position:0% +processors are accessing the same cache +line and at least one of them is writing + + align:start position:0% +line and at least one of them is writing + + + align:start position:0% +line and at least one of them is writing +to that cache line if all the processors + + align:start position:0% +to that cache line if all the processors + + + align:start position:0% +to that cache line if all the processors +are just reading from the cache line + + align:start position:0% +are just reading from the cache line + + + align:start position:0% +are just reading from the cache line +then the cache coherence protocol knows + + align:start position:0% +then the cache coherence protocol knows + + + align:start position:0% +then the cache coherence protocol knows +how to make it work so that you don't + + align:start position:0% +how to make it work so that you don't + + + align:start position:0% +how to make it work so that you don't +get cache misses they can all access the + + align:start position:0% +get cache misses they can all access the + + + align:start position:0% +get cache misses they can all access the +same cache line at the same time if + + align:start position:0% +same cache line at the same time if + + + align:start position:0% +same cache line at the same time if +nobody's modifying it but if at least + + align:start position:0% +nobody's modifying it but if at least + + + align:start position:0% +nobody's modifying it but if at least +one processor is modifying it you could + + align:start position:0% +one processor is modifying it you could + + + align:start position:0% +one processor is modifying it you could +get either true sharing misses or false + + align:start position:0% +get either true sharing misses or false + + + align:start position:0% +get either true sharing misses or false +sharing misses so a true sharing miss is + + align:start position:0% +sharing misses so a true sharing miss is + + + align:start position:0% +sharing misses so a true sharing miss is +when two processors are accessing the + + align:start position:0% +when two processors are accessing the + + + align:start position:0% +when two processors are accessing the +same data on the same cache line and as + + align:start position:0% +same data on the same cache line and as + + + align:start position:0% +same data on the same cache line and as +you recall from a previous lecture if + + align:start position:0% +you recall from a previous lecture if + + + align:start position:0% +you recall from a previous lecture if +one of the two processors is writing to + + align:start position:0% +one of the two processors is writing to + + + align:start position:0% +one of the two processors is writing to +this cache line whenever it does a write + + align:start position:0% +this cache line whenever it does a write + + + align:start position:0% +this cache line whenever it does a write +in that it needs to acquire the cache + + align:start position:0% +in that it needs to acquire the cache + + + align:start position:0% +in that it needs to acquire the cache +line in exclusive mode and then + + align:start position:0% +line in exclusive mode and then + + + align:start position:0% +line in exclusive mode and then +invalidate the that cache line in all + + align:start position:0% +invalidate the that cache line in all + + + align:start position:0% +invalidate the that cache line in all +other caches so then when when another + + align:start position:0% +other caches so then when when another + + + align:start position:0% +other caches so then when when another +processor tries to access the same + + align:start position:0% +processor tries to access the same + + + align:start position:0% +processor tries to access the same +memory location has to bring it back + + align:start position:0% +memory location has to bring it back + + + align:start position:0% +memory location has to bring it back +into its own cache and then you get a + + align:start position:0% +into its own cache and then you get a + + + align:start position:0% +into its own cache and then you get a +cache miss there a false sharing miss + + align:start position:0% +cache miss there a false sharing miss + + + align:start position:0% +cache miss there a false sharing miss +happens if two processes are accessing + + align:start position:0% +happens if two processes are accessing + + + align:start position:0% +happens if two processes are accessing +different data that just happened to + + align:start position:0% +different data that just happened to + + + align:start position:0% +different data that just happened to +reside on the same cache line because + + align:start position:0% +reside on the same cache line because + + + align:start position:0% +reside on the same cache line because +the basic unit of movement is a cache + + align:start position:0% +the basic unit of movement is a cache + + + align:start position:0% +the basic unit of movement is a cache +line in the architecture so even if + + align:start position:0% +line in the architecture so even if + + + align:start position:0% +line in the architecture so even if +you're accessing different things if + + align:start position:0% +you're accessing different things if + + + align:start position:0% +you're accessing different things if +they are on the same cache line you're + + align:start position:0% +they are on the same cache line you're + + + align:start position:0% +they are on the same cache line you're +still going to get a sharing miss and + + align:start position:0% +still going to get a sharing miss and + + + align:start position:0% +still going to get a sharing miss and +fall sharing is pretty hard to deal with + + align:start position:0% +fall sharing is pretty hard to deal with + + + align:start position:0% +fall sharing is pretty hard to deal with +because in general you don't know what + + align:start position:0% +because in general you don't know what + + + align:start position:0% +because in general you don't know what +data gets placed on what cache line + + align:start position:0% +data gets placed on what cache line + + + align:start position:0% +data gets placed on what cache line +there's certain heuristics you can use + + align:start position:0% +there's certain heuristics you can use + + + align:start position:0% +there's certain heuristics you can use +for example of your mouth looking a big + + align:start position:0% +for example of your mouth looking a big + + + align:start position:0% +for example of your mouth looking a big +we region you know that that memory + + align:start position:0% +we region you know that that memory + + + align:start position:0% +we region you know that that memory +region is contiguous so you can space + + align:start position:0% +region is contiguous so you can space + + + align:start position:0% +region is contiguous so you can space +your access is far enough apart by + + align:start position:0% +your access is far enough apart by + + + align:start position:0% +your access is far enough apart by +different processors so they don't touch + + align:start position:0% +different processors so they don't touch + + + align:start position:0% +different processors so they don't touch +the same cache line so if you're just + + align:start position:0% +the same cache line so if you're just + + + align:start position:0% +the same cache line so if you're just +declaring local variables on the stack + + align:start position:0% +declaring local variables on the stack + + + align:start position:0% +declaring local variables on the stack +you don't know where the compiler is + + align:start position:0% +you don't know where the compiler is + + + align:start position:0% +you don't know where the compiler is +going to decide to place these variables + + align:start position:0% +going to decide to place these variables + + + align:start position:0% +going to decide to place these variables +in the virtual memory address space so + + align:start position:0% +in the virtual memory address space so + + + align:start position:0% +in the virtual memory address space so +these are for different types of cache + + align:start position:0% +these are for different types of cache + + + align:start position:0% +these are for different types of cache +misses that you should know about + + align:start position:0% +misses that you should know about + + + align:start position:0% +misses that you should know about +and there's many models out there for + + align:start position:0% +and there's many models out there for + + + align:start position:0% +and there's many models out there for +analyzing the cache performance of + + align:start position:0% +analyzing the cache performance of + + + align:start position:0% +analyzing the cache performance of +algorithms and some of the models ignore + + align:start position:0% +algorithms and some of the models ignore + + + align:start position:0% +algorithms and some of the models ignore +some of these different types of cache + + align:start position:0% +some of these different types of cache + + + align:start position:0% +some of these different types of cache +misses so just be aware of this when + + align:start position:0% +misses so just be aware of this when + + + align:start position:0% +misses so just be aware of this when +you're looking at algorithm analysis + + align:start position:0% +you're looking at algorithm analysis + + + align:start position:0% +you're looking at algorithm analysis +because not all the models will capture + + align:start position:0% +because not all the models will capture + + + align:start position:0% +because not all the models will capture +all of these different types of cache + + align:start position:0% +all of these different types of cache + + + align:start position:0% +all of these different types of cache +misses so let's look at a bad case for + + align:start position:0% +misses so let's look at a bad case for + + + align:start position:0% +misses so let's look at a bad case for +conflict misses so here I'm I have a I + + align:start position:0% +conflict misses so here I'm I have a I + + + align:start position:0% +conflict misses so here I'm I have a I +want to access a sub matrix within a + + align:start position:0% +want to access a sub matrix within a + + + align:start position:0% +want to access a sub matrix within a +larger matrix and recall that the + + align:start position:0% +larger matrix and recall that the + + + align:start position:0% +larger matrix and recall that the +matrices are stored in row major order + + align:start position:0% +matrices are stored in row major order + + + align:start position:0% +matrices are stored in row major order +and let's say our matrix is 4096 columns + + align:start position:0% +and let's say our matrix is 4096 columns + + + align:start position:0% +and let's say our matrix is 4096 columns +by 4096 rows and it still stores doubles + + align:start position:0% +by 4096 rows and it still stores doubles + + + align:start position:0% +by 4096 rows and it still stores doubles +so therefore each row here is going to + + align:start position:0% +so therefore each row here is going to + + + align:start position:0% +so therefore each row here is going to +contain two to the fifteenth bytes + + align:start position:0% +contain two to the fifteenth bytes + + + align:start position:0% +contain two to the fifteenth bytes +because 4096 is 2 to the 12 and we have + + align:start position:0% +because 4096 is 2 to the 12 and we have + + + align:start position:0% +because 4096 is 2 to the 12 and we have +doubles each one of which takes 8 bytes + + align:start position:0% +doubles each one of which takes 8 bytes + + + align:start position:0% +doubles each one of which takes 8 bytes +so 2 to 12 times 2 to the third which is + + align:start position:0% +so 2 to 12 times 2 to the third which is + + + align:start position:0% +so 2 to 12 times 2 to the third which is +2 to 15th we're gonna assume the word + + align:start position:0% +2 to 15th we're gonna assume the word + + + align:start position:0% +2 to 15th we're gonna assume the word +width is 64 which is standard we're + + align:start position:0% +width is 64 which is standard we're + + + align:start position:0% +width is 64 which is standard we're +gonna assume that we have a cache size + + align:start position:0% +gonna assume that we have a cache size + + + align:start position:0% +gonna assume that we have a cache size +of 32 K and the cache block size is 64 + + align:start position:0% +of 32 K and the cache block size is 64 + + + align:start position:0% +of 32 K and the cache block size is 64 +which again is standard and let's say we + + align:start position:0% +which again is standard and let's say we + + + align:start position:0% +which again is standard and let's say we +have a four-way associative cache so + + align:start position:0% +have a four-way associative cache so + + + align:start position:0% +have a four-way associative cache so +let's look at how the how the bits are + + align:start position:0% +let's look at how the how the bits are + + + align:start position:0% +let's look at how the how the bits are +divided into so again we have this + + align:start position:0% +divided into so again we have this + + + align:start position:0% +divided into so again we have this +offset which takes log base 2 of B bits + + align:start position:0% +offset which takes log base 2 of B bits + + + align:start position:0% +offset which takes log base 2 of B bits +so how many bits do we have for the + + align:start position:0% +so how many bits do we have for the + + + align:start position:0% +so how many bits do we have for the +offset in this example + + align:start position:0% + + + + align:start position:0% + +all right so we have six bits so it's + + align:start position:0% +all right so we have six bits so it's + + + align:start position:0% +all right so we have six bits so it's +just log base 2 of 64 what about for + + align:start position:0% +just log base 2 of 64 what about for + + + align:start position:0% +just log base 2 of 64 what about for +this set how many bits do we have for + + align:start position:0% +this set how many bits do we have for + + + align:start position:0% +this set how many bits do we have for +that seven who said seven yeah so so it + + align:start position:0% +that seven who said seven yeah so so it + + + align:start position:0% +that seven who said seven yeah so so it +is seven so M is 32 K which is to 215th + + align:start position:0% +is seven so M is 32 K which is to 215th + + + align:start position:0% +is seven so M is 32 K which is to 215th +and then k is 2 to the 2 b is 2 to the 2 + + align:start position:0% +and then k is 2 to the 2 b is 2 to the 2 + + + align:start position:0% +and then k is 2 to the 2 b is 2 to the 2 +to the 6 so it's 2 to 15 divided by 2 + + align:start position:0% +to the 6 so it's 2 to 15 divided by 2 + + + align:start position:0% +to the 6 so it's 2 to 15 divided by 2 +the 8 which is 2 to 7th and log base 2 + + align:start position:0% +the 8 which is 2 to 7th and log base 2 + + + align:start position:0% +the 8 which is 2 to 7th and log base 2 +of that is 7 and finally what about the + + align:start position:0% +of that is 7 and finally what about the + + + align:start position:0% +of that is 7 and finally what about the +tag field + + align:start position:0% + + + + align:start position:0% + +51 why is that yes it's just 64 minus + + align:start position:0% +51 why is that yes it's just 64 minus + + + align:start position:0% +51 why is that yes it's just 64 minus +seven minus six which is 51 okay so + + align:start position:0% +seven minus six which is 51 okay so + + + align:start position:0% +seven minus six which is 51 okay so +let's say that we want to access a sub + + align:start position:0% +let's say that we want to access a sub + + + align:start position:0% +let's say that we want to access a sub +matrix within this larger matrix let's + + align:start position:0% +matrix within this larger matrix let's + + + align:start position:0% +matrix within this larger matrix let's +say we want to access a 32 by 32 sub + + align:start position:0% +say we want to access a 32 by 32 sub + + + align:start position:0% +say we want to access a 32 by 32 sub +matrix and this is pretty common in + + align:start position:0% +matrix and this is pretty common in + + + align:start position:0% +matrix and this is pretty common in +matrix algorithms where you want to + + align:start position:0% +matrix algorithms where you want to + + + align:start position:0% +matrix algorithms where you want to +access sub matrices especially in + + align:start position:0% +access sub matrices especially in + + + align:start position:0% +access sub matrices especially in +dividing conquer algorithms and let's + + align:start position:0% +dividing conquer algorithms and let's + + + align:start position:0% +dividing conquer algorithms and let's +say we want to access a column of this + + align:start position:0% +say we want to access a column of this + + + align:start position:0% +say we want to access a column of this +sub matrix a so the addresses of the + + align:start position:0% +sub matrix a so the addresses of the + + + align:start position:0% +sub matrix a so the addresses of the +elements that we're going to access are + + align:start position:0% +elements that we're going to access are + + + align:start position:0% +elements that we're going to access are +as follows so let's say we the first + + align:start position:0% +as follows so let's say we the first + + + align:start position:0% +as follows so let's say we the first +element in a column is sort out address + + align:start position:0% +element in a column is sort out address + + + align:start position:0% +element in a column is sort out address +X then the second element in the column + + align:start position:0% +X then the second element in the column + + + align:start position:0% +X then the second element in the column +is going to be stored at address X plus + + align:start position:0% +is going to be stored at address X plus + + + align:start position:0% +is going to be stored at address X plus +two to the fifteenth because each row + + align:start position:0% +two to the fifteenth because each row + + + align:start position:0% +two to the fifteenth because each row +has two to the fifteenth bytes and we're + + align:start position:0% +has two to the fifteenth bytes and we're + + + align:start position:0% +has two to the fifteenth bytes and we're +skipping over an entire row here to get + + align:start position:0% +skipping over an entire row here to get + + + align:start position:0% +skipping over an entire row here to get +to the element in the second in the next + + align:start position:0% +to the element in the second in the next + + + align:start position:0% +to the element in the second in the next +row of the sub matrix so we're gonna add + + align:start position:0% +row of the sub matrix so we're gonna add + + + align:start position:0% +row of the sub matrix so we're gonna add +to the fifteenth and then to get the + + align:start position:0% +to the fifteenth and then to get the + + + align:start position:0% +to the fifteenth and then to get the +third element we're gonna add two times + + align:start position:0% +third element we're gonna add two times + + + align:start position:0% +third element we're gonna add two times +two to the fifteenth and so on until we + + align:start position:0% +two to the fifteenth and so on until we + + + align:start position:0% +two to the fifteenth and so on until we +get to the last element which is X plus + + align:start position:0% +get to the last element which is X plus + + + align:start position:0% +get to the last element which is X plus +31 times two to the fifteenth so which + + align:start position:0% +31 times two to the fifteenth so which + + + align:start position:0% +31 times two to the fifteenth so which +the olds of the address are changing as + + align:start position:0% +the olds of the address are changing as + + + align:start position:0% +the olds of the address are changing as +we go through one column of this sub + + align:start position:0% +we go through one column of this sub + + + align:start position:0% +we go through one column of this sub +matrix + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% + + + + align:start position:0% + +yeah so it's just gonna be the tag + + align:start position:0% +yeah so it's just gonna be the tag + + + align:start position:0% +yeah so it's just gonna be the tag +that's changing the set and the offset + + align:start position:0% +that's changing the set and the offset + + + align:start position:0% +that's changing the set and the offset +are gonna stay the same because we're + + align:start position:0% +are gonna stay the same because we're + + + align:start position:0% +are gonna stay the same because we're +just using the lower 13 bits to store + + align:start position:0% +just using the lower 13 bits to store + + + align:start position:0% +just using the lower 13 bits to store +the setna tag and therefore when we + + align:start position:0% +the setna tag and therefore when we + + + align:start position:0% +the setna tag and therefore when we +increment by to the 15th we're not going + + align:start position:0% +increment by to the 15th we're not going + + + align:start position:0% +increment by to the 15th we're not going +to touch the set in the offset so all of + + align:start position:0% +to touch the set in the offset so all of + + + align:start position:0% +to touch the set in the offset so all of +these addresses fall into the same set + + align:start position:0% +these addresses fall into the same set + + + align:start position:0% +these addresses fall into the same set +and this is a problem because ours us + + align:start position:0% +and this is a problem because ours us + + + align:start position:0% +and this is a problem because ours us +our cache is only 4-way associative so + + align:start position:0% +our cache is only 4-way associative so + + + align:start position:0% +our cache is only 4-way associative so +we can only fit for cash for cache lines + + align:start position:0% +we can only fit for cash for cache lines + + + align:start position:0% +we can only fit for cash for cache lines +in each set and here we're accessing 31 + + align:start position:0% +in each set and here we're accessing 31 + + + align:start position:0% +in each set and here we're accessing 31 +of these things so by the time we get to + + align:start position:0% +of these things so by the time we get to + + + align:start position:0% +of these things so by the time we get to +the next column of a all the things that + + align:start position:0% +the next column of a all the things that + + + align:start position:0% +the next column of a all the things that +we access in the current column of a are + + align:start position:0% +we access in the current column of a are + + + align:start position:0% +we access in the current column of a are +going to be evicted from cache already + + align:start position:0% +going to be evicted from cache already + + + align:start position:0% +going to be evicted from cache already +and this is known as a conflict miss + + align:start position:0% +and this is known as a conflict miss + + + align:start position:0% +and this is known as a conflict miss +because if if you had a fully + + align:start position:0% +because if if you had a fully + + + align:start position:0% +because if if you had a fully +associative cache this might not have + + align:start position:0% +associative cache this might not have + + + align:start position:0% +associative cache this might not have +happened because you could actually use + + align:start position:0% +happened because you could actually use + + + align:start position:0% +happened because you could actually use +any location in the cache to store these + + align:start position:0% +any location in the cache to store these + + + align:start position:0% +any location in the cache to store these +cache blocks so is anybody have any + + align:start position:0% +cache blocks so is anybody have any + + + align:start position:0% +cache blocks so is anybody have any +questions on why we get conflict misses + + align:start position:0% +questions on why we get conflict misses + + + align:start position:0% +questions on why we get conflict misses +here + + align:start position:0% + + + + align:start position:0% + +so anybody have any ideas on how to fix + + align:start position:0% +so anybody have any ideas on how to fix + + + align:start position:0% +so anybody have any ideas on how to fix +this so what can I do to make it so that + + align:start position:0% +this so what can I do to make it so that + + + align:start position:0% +this so what can I do to make it so that +I'm not incrementing by to the exactly + + align:start position:0% +I'm not incrementing by to the exactly + + + align:start position:0% +I'm not incrementing by to the exactly +to the 15th every time + + align:start position:0% + + + + align:start position:0% + +yeah yeah yeah yeah so one solution is + + align:start position:0% +yeah yeah yeah yeah so one solution is + + + align:start position:0% +yeah yeah yeah yeah so one solution is +to Pat the matrix you can add some + + align:start position:0% +to Pat the matrix you can add some + + + align:start position:0% +to Pat the matrix you can add some +constant amount of space to the end of + + align:start position:0% +constant amount of space to the end of + + + align:start position:0% +constant amount of space to the end of +the matrix so each row is gonna be + + align:start position:0% +the matrix so each row is gonna be + + + align:start position:0% +the matrix so each row is gonna be +longer than to the 15th bytes so maybe + + align:start position:0% +longer than to the 15th bytes so maybe + + + align:start position:0% +longer than to the 15th bytes so maybe +you add some small constant like 17 so + + align:start position:0% +you add some small constant like 17 so + + + align:start position:0% +you add some small constant like 17 so +add 17 bytes the end of each row and now + + align:start position:0% +add 17 bytes the end of each row and now + + + align:start position:0% +add 17 bytes the end of each row and now +when you act as a column of this sub + + align:start position:0% +when you act as a column of this sub + + + align:start position:0% +when you act as a column of this sub +matrix + + align:start position:0% +matrix + + + align:start position:0% +matrix +you're not just incrementing by to the + + align:start position:0% +you're not just incrementing by to the + + + align:start position:0% +you're not just incrementing by to the +15th you're also adding some small + + align:start position:0% +15th you're also adding some small + + + align:start position:0% +15th you're also adding some small +integer and that's going to cause the + + align:start position:0% +integer and that's going to cause the + + + align:start position:0% +integer and that's going to cause the +set and offset fields to change as well + + align:start position:0% +set and offset fields to change as well + + + align:start position:0% +set and offset fields to change as well +and you're not going to get as many + + align:start position:0% +and you're not going to get as many + + + align:start position:0% +and you're not going to get as many +conflict misses so that's one way to + + align:start position:0% +conflict misses so that's one way to + + + align:start position:0% +conflict misses so that's one way to +solve the problem it turns out that if + + align:start position:0% +solve the problem it turns out that if + + + align:start position:0% +solve the problem it turns out that if +you're doing a matrix multiplication + + align:start position:0% +you're doing a matrix multiplication + + + align:start position:0% +you're doing a matrix multiplication +algorithm that's a cubic work algorithm + + align:start position:0% +algorithm that's a cubic work algorithm + + + align:start position:0% +algorithm that's a cubic work algorithm +and you can basically afford to copy the + + align:start position:0% +and you can basically afford to copy the + + + align:start position:0% +and you can basically afford to copy the +sub matrix into a temporary 32 by 32 + + align:start position:0% +sub matrix into a temporary 32 by 32 + + + align:start position:0% +sub matrix into a temporary 32 by 32 +matrix do all the operations on the + + align:start position:0% +matrix do all the operations on the + + + align:start position:0% +matrix do all the operations on the +temporary matrix and then copy it back + + align:start position:0% +temporary matrix and then copy it back + + + align:start position:0% +temporary matrix and then copy it back +out to the original matrix the copy + + align:start position:0% +out to the original matrix the copy + + + align:start position:0% +out to the original matrix the copy +copying only takes quadratic work to do + + align:start position:0% +copying only takes quadratic work to do + + + align:start position:0% +copying only takes quadratic work to do +across the whole algorithm and since the + + align:start position:0% +across the whole algorithm and since the + + + align:start position:0% +across the whole algorithm and since the +whole algorithm takes cubic work the + + align:start position:0% +whole algorithm takes cubic work the + + + align:start position:0% +whole algorithm takes cubic work the +quadratic work is a lower order term so + + align:start position:0% +quadratic work is a lower order term so + + + align:start position:0% +quadratic work is a lower order term so +you can also you can use temporary space + + align:start position:0% +you can also you can use temporary space + + + align:start position:0% +you can also you can use temporary space +to make sure that you don't get conflict + + align:start position:0% +to make sure that you don't get conflict + + + align:start position:0% +to make sure that you don't get conflict +misses any questions + + align:start position:0% + + + + align:start position:0% + +okay so this was conflict misses so + + align:start position:0% +okay so this was conflict misses so + + + align:start position:0% +okay so this was conflict misses so +conflict misses are important but + + align:start position:0% +conflict misses are important but + + + align:start position:0% +conflict misses are important but +usually we're going to be first + + align:start position:0% +usually we're going to be first + + + align:start position:0% +usually we're going to be first +concerned about getting good spatial and + + align:start position:0% +concerned about getting good spatial and + + + align:start position:0% +concerned about getting good spatial and +temporal locality because those are + + align:start position:0% +temporal locality because those are + + + align:start position:0% +temporal locality because those are +usually the higher-order factors in the + + align:start position:0% +usually the higher-order factors in the + + + align:start position:0% +usually the higher-order factors in the +performance of a program once we get + + align:start position:0% +performance of a program once we get + + + align:start position:0% +performance of a program once we get +good spatial and temporal locality in + + align:start position:0% +good spatial and temporal locality in + + + align:start position:0% +good spatial and temporal locality in +our program we can then start worrying + + align:start position:0% +our program we can then start worrying + + + align:start position:0% +our program we can then start worrying +about conflict misses for example by + + align:start position:0% +about conflict misses for example by + + + align:start position:0% +about conflict misses for example by +using temporary space or padding or our + + align:start position:0% +using temporary space or padding or our + + + align:start position:0% +using temporary space or padding or our +data by some small constants so that we + + align:start position:0% +data by some small constants so that we + + + align:start position:0% +data by some small constants so that we +don't have as many conflict misses okay + + align:start position:0% +don't have as many conflict misses okay + + + align:start position:0% +don't have as many conflict misses okay +so now I want to talk about a model that + + align:start position:0% +so now I want to talk about a model that + + + align:start position:0% +so now I want to talk about a model that +we can use to analyze the cache + + align:start position:0% +we can use to analyze the cache + + + align:start position:0% +we can use to analyze the cache +performance of algorithms and this is + + align:start position:0% +performance of algorithms and this is + + + align:start position:0% +performance of algorithms and this is +called the ideal cache model so in this + + align:start position:0% +called the ideal cache model so in this + + + align:start position:0% +called the ideal cache model so in this +model we have a two level cache + + align:start position:0% +model we have a two level cache + + + align:start position:0% +model we have a two level cache +hierarchy so we have the cash and then + + align:start position:0% +hierarchy so we have the cash and then + + + align:start position:0% +hierarchy so we have the cash and then +main memory the cache size is of size M + + align:start position:0% +main memory the cache size is of size M + + + align:start position:0% +main memory the cache size is of size M +and the cache line sizes of B bytes and + + align:start position:0% +and the cache line sizes of B bytes and + + + align:start position:0% +and the cache line sizes of B bytes and +therefore we can fit M over B cache + + align:start position:0% +therefore we can fit M over B cache + + + align:start position:0% +therefore we can fit M over B cache +lines inside our cache this model + + align:start position:0% +lines inside our cache this model + + + align:start position:0% +lines inside our cache this model +assumes that the cache is fully + + align:start position:0% +assumes that the cache is fully + + + align:start position:0% +assumes that the cache is fully +associative so any cache block can go + + align:start position:0% +associative so any cache block can go + + + align:start position:0% +associative so any cache block can go +anywhere in the cache and it also + + align:start position:0% +anywhere in the cache and it also + + + align:start position:0% +anywhere in the cache and it also +assumes an optimal Nishant replacement + + align:start position:0% +assumes an optimal Nishant replacement + + + align:start position:0% +assumes an optimal Nishant replacement +policy so this means that what we want + + align:start position:0% +policy so this means that what we want + + + align:start position:0% +policy so this means that what we want +to evict a cache block from the cache + + align:start position:0% +to evict a cache block from the cache + + + align:start position:0% +to evict a cache block from the cache +we're going to pick the thing to evict + + align:start position:0% +we're going to pick the thing to evict + + + align:start position:0% +we're going to pick the thing to evict +that gives us the best performance over + + align:start position:0% +that gives us the best performance over + + + align:start position:0% +that gives us the best performance over +all it gives us the lowest number of + + align:start position:0% +all it gives us the lowest number of + + + align:start position:0% +all it gives us the lowest number of +cache misses throughout our entire + + align:start position:0% +cache misses throughout our entire + + + align:start position:0% +cache misses throughout our entire +algorithm so we're assuming that we know + + align:start position:0% +algorithm so we're assuming that we know + + + align:start position:0% +algorithm so we're assuming that we know +the sequence of memory requests + + align:start position:0% +the sequence of memory requests + + + align:start position:0% +the sequence of memory requests +throughout the entire algorithm and + + align:start position:0% +throughout the entire algorithm and + + + align:start position:0% +throughout the entire algorithm and +that's why it's called the nisshin + + align:start position:0% +that's why it's called the nisshin + + + align:start position:0% +that's why it's called the nisshin +replacement policy and if something is + + align:start position:0% +replacement policy and if something is + + + align:start position:0% +replacement policy and if something is +in cache you can operate on it for free + + align:start position:0% +in cache you can operate on it for free + + + align:start position:0% +in cache you can operate on it for free +and if something is in main memory you + + align:start position:0% +and if something is in main memory you + + + align:start position:0% +and if something is in main memory you +have to bring it into cache and then you + + align:start position:0% +have to bring it into cache and then you + + + align:start position:0% +have to bring it into cache and then you +incur a cache miss so there are two + + align:start position:0% +incur a cache miss so there are two + + + align:start position:0% +incur a cache miss so there are two +performance measures that we care about + + align:start position:0% +performance measures that we care about + + + align:start position:0% +performance measures that we care about +first we care about the order in any + + align:start position:0% +first we care about the order in any + + + align:start position:0% +first we care about the order in any +work which is just the ordinary running + + align:start position:0% +work which is just the ordinary running + + + align:start position:0% +work which is just the ordinary running +time of a program so this this is the + + align:start position:0% +time of a program so this this is the + + + align:start position:0% +time of a program so this this is the +same as before when we were analyzing + + align:start position:0% +same as before when we were analyzing + + + align:start position:0% +same as before when we were analyzing +algorithms it's just a total number of + + align:start position:0% +algorithms it's just a total number of + + + align:start position:0% +algorithms it's just a total number of +operations that the program does and the + + align:start position:0% +operations that the program does and the + + + align:start position:0% +operations that the program does and the +number of cache misses is going to be + + align:start position:0% +number of cache misses is going to be + + + align:start position:0% +number of cache misses is going to be +the number of + + align:start position:0% +the number of + + + align:start position:0% +the number of +we have to transfer between the main + + align:start position:0% +we have to transfer between the main + + + align:start position:0% +we have to transfer between the main +memory and the cache so a number of + + align:start position:0% +memory and the cache so a number of + + + align:start position:0% +memory and the cache so a number of +cache misses just counts the number of + + align:start position:0% +cache misses just counts the number of + + + align:start position:0% +cache misses just counts the number of +cash transfers whereas the work counts + + align:start position:0% +cash transfers whereas the work counts + + + align:start position:0% +cash transfers whereas the work counts +all the operations that you have to do + + align:start position:0% +all the operations that you have to do + + + align:start position:0% +all the operations that you have to do +in the algorithm so ideally we would + + align:start position:0% +in the algorithm so ideally we would + + + align:start position:0% +in the algorithm so ideally we would +like to come up with algorithms that + + align:start position:0% +like to come up with algorithms that + + + align:start position:0% +like to come up with algorithms that +have a low number of cache misses + + align:start position:0% +have a low number of cache misses + + + align:start position:0% +have a low number of cache misses +without increasing the work from the + + align:start position:0% +without increasing the work from the + + + align:start position:0% +without increasing the work from the +traditional standard algorithm sometimes + + align:start position:0% +traditional standard algorithm sometimes + + + align:start position:0% +traditional standard algorithm sometimes +we can do that sometimes we can't do + + align:start position:0% +we can do that sometimes we can't do + + + align:start position:0% +we can do that sometimes we can't do +that and then there's a trade-off + + align:start position:0% +that and then there's a trade-off + + + align:start position:0% +that and then there's a trade-off +between the work and the number of cache + + align:start position:0% +between the work and the number of cache + + + align:start position:0% +between the work and the number of cache +misses and and then you it's a trade-off + + align:start position:0% +misses and and then you it's a trade-off + + + align:start position:0% +misses and and then you it's a trade-off +that you have to decide whether it's + + align:start position:0% +that you have to decide whether it's + + + align:start position:0% +that you have to decide whether it's +worthwhile as a performance engineer + + align:start position:0% +worthwhile as a performance engineer + + + align:start position:0% +worthwhile as a performance engineer +today we're gonna look at an algorithm + + align:start position:0% +today we're gonna look at an algorithm + + + align:start position:0% +today we're gonna look at an algorithm +where you can't actually reduce a number + + align:start position:0% +where you can't actually reduce a number + + + align:start position:0% +where you can't actually reduce a number +of cache misses without increasing the + + align:start position:0% +of cache misses without increasing the + + + align:start position:0% +of cache misses without increasing the +work so you basically get the best of + + align:start position:0% +work so you basically get the best of + + + align:start position:0% +work so you basically get the best of +both worlds so any questions on this + + align:start position:0% +both worlds so any questions on this + + + align:start position:0% +both worlds so any questions on this +ideal cache model + + align:start position:0% + + + + align:start position:0% + +so this model is just used for analyzing + + align:start position:0% +so this model is just used for analyzing + + + align:start position:0% +so this model is just used for analyzing +algorithms you can't actually buy one of + + align:start position:0% +algorithms you can't actually buy one of + + + align:start position:0% +algorithms you can't actually buy one of +these caches at the store so this is a + + align:start position:0% +these caches at the store so this is a + + + align:start position:0% +these caches at the store so this is a +very ideal cache and they don't exist + + align:start position:0% +very ideal cache and they don't exist + + + align:start position:0% +very ideal cache and they don't exist +but it turns out that this optimal + + align:start position:0% +but it turns out that this optimal + + + align:start position:0% +but it turns out that this optimal +initial reply sment policy has nice + + align:start position:0% +initial reply sment policy has nice + + + align:start position:0% +initial reply sment policy has nice +theoretical properties and this is a + + align:start position:0% +theoretical properties and this is a + + + align:start position:0% +theoretical properties and this is a +very important lemma that has that was + + align:start position:0% +very important lemma that has that was + + + align:start position:0% +very important lemma that has that was +proved in 1985 it's called the LRU lemma + + align:start position:0% +proved in 1985 it's called the LRU lemma + + + align:start position:0% +proved in 1985 it's called the LRU lemma +it was proof by Slater and targe end and + + align:start position:0% +it was proof by Slater and targe end and + + + align:start position:0% +it was proof by Slater and targe end and +the lemma says suppose that an algorithm + + align:start position:0% +the lemma says suppose that an algorithm + + + align:start position:0% +the lemma says suppose that an algorithm +incurs Q cache misses on an ideal cache + + align:start position:0% +incurs Q cache misses on an ideal cache + + + align:start position:0% +incurs Q cache misses on an ideal cache +of size M then on a fully associative + + align:start position:0% +of size M then on a fully associative + + + align:start position:0% +of size M then on a fully associative +cache of size 2m that uses the LRU or + + align:start position:0% +cache of size 2m that uses the LRU or + + + align:start position:0% +cache of size 2m that uses the LRU or +least recently used replacement policy + + align:start position:0% +least recently used replacement policy + + + align:start position:0% +least recently used replacement policy +it incurs at most 2q cache misses so + + align:start position:0% +it incurs at most 2q cache misses so + + + align:start position:0% +it incurs at most 2q cache misses so +what this says is if I can show the + + align:start position:0% +what this says is if I can show the + + + align:start position:0% +what this says is if I can show the +number of cache misses for an algorithm + + align:start position:0% +number of cache misses for an algorithm + + + align:start position:0% +number of cache misses for an algorithm +on the ideal cache then if I take a + + align:start position:0% +on the ideal cache then if I take a + + + align:start position:0% +on the ideal cache then if I take a +fully associative cache that's twice the + + align:start position:0% +fully associative cache that's twice the + + + align:start position:0% +fully associative cache that's twice the +size and use the LRU replacement policy + + align:start position:0% +size and use the LRU replacement policy + + + align:start position:0% +size and use the LRU replacement policy +which is a pretty practical policy then + + align:start position:0% +which is a pretty practical policy then + + + align:start position:0% +which is a pretty practical policy then +the algorithm is going to incur at most + + align:start position:0% +the algorithm is going to incur at most + + + align:start position:0% +the algorithm is going to incur at most +twice the number of cache misses and the + + align:start position:0% +twice the number of cache misses and the + + + align:start position:0% +twice the number of cache misses and the +implication of this Lama is that for + + align:start position:0% +implication of this Lama is that for + + + align:start position:0% +implication of this Lama is that for +asymptotic analysis you can assume + + align:start position:0% +asymptotic analysis you can assume + + + align:start position:0% +asymptotic analysis you can assume +either the optimal replacement policy or + + align:start position:0% +either the optimal replacement policy or + + + align:start position:0% +either the optimal replacement policy or +the LRU replacement policy as convenient + + align:start position:0% +the LRU replacement policy as convenient + + + align:start position:0% +the LRU replacement policy as convenient +because because the cache number of + + align:start position:0% +because because the cache number of + + + align:start position:0% +because because the cache number of +cache misses is just going to be within + + align:start position:0% +cache misses is just going to be within + + + align:start position:0% +cache misses is just going to be within +a constant factor of each other so this + + align:start position:0% +a constant factor of each other so this + + + align:start position:0% +a constant factor of each other so this +is a very important lemma it says that + + align:start position:0% +is a very important lemma it says that + + + align:start position:0% +is a very important lemma it says that +this basically makes it much easier for + + align:start position:0% +this basically makes it much easier for + + + align:start position:0% +this basically makes it much easier for +us to analyze our cache misses and + + align:start position:0% +us to analyze our cache misses and + + + align:start position:0% +us to analyze our cache misses and +algorithms and here's a software + + align:start position:0% +algorithms and here's a software + + + align:start position:0% +algorithms and here's a software +engineering principle that I want to + + align:start position:0% +engineering principle that I want to + + + align:start position:0% +engineering principle that I want to +point out so first when you're trying to + + align:start position:0% +point out so first when you're trying to + + + align:start position:0% +point out so first when you're trying to +get good performance you should come up + + align:start position:0% +get good performance you should come up + + + align:start position:0% +get good performance you should come up +with a theoretically good algorithm that + + align:start position:0% +with a theoretically good algorithm that + + + align:start position:0% +with a theoretically good algorithm that +has good bounds on the work in the cache + + align:start position:0% +has good bounds on the work in the cache + + + align:start position:0% +has good bounds on the work in the cache +complexity and after you come up with a + + align:start position:0% +complexity and after you come up with a + + + align:start position:0% +complexity and after you come up with a +algorithm that's theoretically good then + + align:start position:0% +algorithm that's theoretically good then + + + align:start position:0% +algorithm that's theoretically good then +you start engineering for detailed + + align:start position:0% +you start engineering for detailed + + + align:start position:0% +you start engineering for detailed +performance you start worrying about the + + align:start position:0% +performance you start worrying about the + + + align:start position:0% +performance you start worrying about the +details such as real world caches not + + align:start position:0% +details such as real world caches not + + + align:start position:0% +details such as real world caches not +being full + + align:start position:0% +being full + + + align:start position:0% +being full +associative and for example loads and + + align:start position:0% +associative and for example loads and + + + align:start position:0% +associative and for example loads and +stores having different costs with + + align:start position:0% +stores having different costs with + + + align:start position:0% +stores having different costs with +respect to bandwidth and latency but + + align:start position:0% +respect to bandwidth and latency but + + + align:start position:0% +respect to bandwidth and latency but +coming up with a theoretically good + + align:start position:0% +coming up with a theoretically good + + + align:start position:0% +coming up with a theoretically good +algorithm is the first-order bit to + + align:start position:0% +algorithm is the first-order bit to + + + align:start position:0% +algorithm is the first-order bit to +getting good performance questions + + align:start position:0% + + + + align:start position:0% + +okay so let's start analyzing the number + + align:start position:0% +okay so let's start analyzing the number + + + align:start position:0% +okay so let's start analyzing the number +of cache misses in program so here's a + + align:start position:0% +of cache misses in program so here's a + + + align:start position:0% +of cache misses in program so here's a +llama + + align:start position:0% +llama + + + align:start position:0% +llama +so the llama says suppose that a program + + align:start position:0% +so the llama says suppose that a program + + + align:start position:0% +so the llama says suppose that a program +reads a set of our data segments where + + align:start position:0% +reads a set of our data segments where + + + align:start position:0% +reads a set of our data segments where +the ithe segment consists of s sub I + + align:start position:0% +the ithe segment consists of s sub I + + + align:start position:0% +the ithe segment consists of s sub I +bytes and suppose that the sum of the + + align:start position:0% +bytes and suppose that the sum of the + + + align:start position:0% +bytes and suppose that the sum of the +sizes of all the segments is equal to N + + align:start position:0% +sizes of all the segments is equal to N + + + align:start position:0% +sizes of all the segments is equal to N +and we're going to assume that n is less + + align:start position:0% +and we're going to assume that n is less + + + align:start position:0% +and we're going to assume that n is less +than M over 3 so the segments the sum of + + align:start position:0% +than M over 3 so the segments the sum of + + + align:start position:0% +than M over 3 so the segments the sum of +the size of the segments is less than + + align:start position:0% +the size of the segments is less than + + + align:start position:0% +the size of the segments is less than +the cache size divided by 3 we're also + + align:start position:0% +the cache size divided by 3 we're also + + + align:start position:0% +the cache size divided by 3 we're also +going to assume that n over R is greater + + align:start position:0% +going to assume that n over R is greater + + + align:start position:0% +going to assume that n over R is greater +than or equal to B so recall that R is + + align:start position:0% +than or equal to B so recall that R is + + + align:start position:0% +than or equal to B so recall that R is +the number of data segments we have and + + align:start position:0% +the number of data segments we have and + + + align:start position:0% +the number of data segments we have and +n is the total size of the segment so + + align:start position:0% +n is the total size of the segment so + + + align:start position:0% +n is the total size of the segment so +what does n over B mean and over R means + + align:start position:0% +what does n over B mean and over R means + + + align:start position:0% +what does n over B mean and over R means +semantically yes yes oh and over R is + + align:start position:0% +semantically yes yes oh and over R is + + + align:start position:0% +semantically yes yes oh and over R is +just the average size of a segment and + + align:start position:0% +just the average size of a segment and + + + align:start position:0% +just the average size of a segment and +here we're saying that the average size + + align:start position:0% +here we're saying that the average size + + + align:start position:0% +here we're saying that the average size +of a segment is at least B's at least + + align:start position:0% +of a segment is at least B's at least + + + align:start position:0% +of a segment is at least B's at least +the size of a cache line so these two + + align:start position:0% +the size of a cache line so these two + + + align:start position:0% +the size of a cache line so these two +assumptions hold then all of the + + align:start position:0% +assumptions hold then all of the + + + align:start position:0% +assumptions hold then all of the +segments are going to fit into cache and + + align:start position:0% +segments are going to fit into cache and + + + align:start position:0% +segments are going to fit into cache and +the number of cache misses to read them + + align:start position:0% +the number of cache misses to read them + + + align:start position:0% +the number of cache misses to read them +all is at most 3 times n over B so if + + align:start position:0% +all is at most 3 times n over B so if + + + align:start position:0% +all is at most 3 times n over B so if +you if you had just a single array of + + align:start position:0% +you if you had just a single array of + + + align:start position:0% +you if you had just a single array of +size n then the number of cache misses + + align:start position:0% +size n then the number of cache misses + + + align:start position:0% +size n then the number of cache misses +you would need to read that array into + + align:start position:0% +you would need to read that array into + + + align:start position:0% +you would need to read that array into +cache is going to be n over B and this + + align:start position:0% +cache is going to be n over B and this + + + align:start position:0% +cache is going to be n over B and this +is saying that even if our data is + + align:start position:0% +is saying that even if our data is + + + align:start position:0% +is saying that even if our data is +divided into a bunch of segments as long + + align:start position:0% +divided into a bunch of segments as long + + + align:start position:0% +divided into a bunch of segments as long +as an average length of the segments is + + align:start position:0% +as an average length of the segments is + + + align:start position:0% +as an average length of the segments is +large enough then a number of cache + + align:start position:0% +large enough then a number of cache + + + align:start position:0% +large enough then a number of cache +misses is just a constant factor worse + + align:start position:0% +misses is just a constant factor worse + + + align:start position:0% +misses is just a constant factor worse +than reading a single array so let's try + + align:start position:0% +than reading a single array so let's try + + + align:start position:0% +than reading a single array so let's try +to prove this cache miss lemma so here's + + align:start position:0% +to prove this cache miss lemma so here's + + + align:start position:0% +to prove this cache miss lemma so here's +a proof so a single segment S sub I is + + align:start position:0% +a proof so a single segment S sub I is + + + align:start position:0% +a proof so a single segment S sub I is +going to incur at most s sub I over B + + align:start position:0% +going to incur at most s sub I over B + + + align:start position:0% +going to incur at most s sub I over B +plus 2 cache misses says anyone want to + + align:start position:0% +plus 2 cache misses says anyone want to + + + align:start position:0% +plus 2 cache misses says anyone want to +tell me where the S sub I over B plus 2 + + align:start position:0% +tell me where the S sub I over B plus 2 + + + align:start position:0% +tell me where the S sub I over B plus 2 +comes from + + align:start position:0% + + + + align:start position:0% + +so this is the let's say this is a + + align:start position:0% +so this is the let's say this is a + + + align:start position:0% +so this is the let's say this is a +segment that we're analyzing and this is + + align:start position:0% +segment that we're analyzing and this is + + + align:start position:0% +segment that we're analyzing and this is +how it's aligned in virtual memory yes + + align:start position:0% + + + + align:start position:0% + +yeah so S sub I over B plus two is the + + align:start position:0% +yeah so S sub I over B plus two is the + + + align:start position:0% +yeah so S sub I over B plus two is the +number of blocks that could overlap with + + align:start position:0% +number of blocks that could overlap with + + + align:start position:0% +number of blocks that could overlap with +in the worst case so you need s mi over + + align:start position:0% +in the worst case so you need s mi over + + + align:start position:0% +in the worst case so you need s mi over +B cache missus just to load those s of I + + align:start position:0% +B cache missus just to load those s of I + + + align:start position:0% +B cache missus just to load those s of I +bytes but then the beginning in the end + + align:start position:0% +bytes but then the beginning in the end + + + align:start position:0% +bytes but then the beginning in the end +of that segment might not be perfectly + + align:start position:0% +of that segment might not be perfectly + + + align:start position:0% +of that segment might not be perfectly +aligned with a cache line boundary and + + align:start position:0% +aligned with a cache line boundary and + + + align:start position:0% +aligned with a cache line boundary and +therefore you could waste at most one + + align:start position:0% +therefore you could waste at most one + + + align:start position:0% +therefore you could waste at most one +block on each side of this segment so + + align:start position:0% +block on each side of this segment so + + + align:start position:0% +block on each side of this segment so +that's where the plus two comes from so + + align:start position:0% +that's where the plus two comes from so + + + align:start position:0% +that's where the plus two comes from so +to get the total number of cache misses + + align:start position:0% +to get the total number of cache misses + + + align:start position:0% +to get the total number of cache misses +we just have to sum this quantity from I + + align:start position:0% +we just have to sum this quantity from I + + + align:start position:0% +we just have to sum this quantity from I +equals 1 to R so if I sum s of I over B + + align:start position:0% +equals 1 to R so if I sum s of I over B + + + align:start position:0% +equals 1 to R so if I sum s of I over B +from I equals 1 to R I just get n over B + + align:start position:0% +from I equals 1 to R I just get n over B + + + align:start position:0% +from I equals 1 to R I just get n over B +by definition and then I sum 2 from + + align:start position:0% +by definition and then I sum 2 from + + + align:start position:0% +by definition and then I sum 2 from +idols 1 to R so that just gives me 2 R + + align:start position:0% +idols 1 to R so that just gives me 2 R + + + align:start position:0% +idols 1 to R so that just gives me 2 R +now I'm going to multiply the top and + + align:start position:0% +now I'm going to multiply the top and + + + align:start position:0% +now I'm going to multiply the top and +the bottom of the second term by B so to + + align:start position:0% +the bottom of the second term by B so to + + + align:start position:0% +the bottom of the second term by B so to +R B over B now and then that's less than + + align:start position:0% +R B over B now and then that's less than + + + align:start position:0% +R B over B now and then that's less than +or equal to n over B plus 2 and over B + + align:start position:0% +or equal to n over B plus 2 and over B + + + align:start position:0% +or equal to n over B plus 2 and over B +so where did I get this inequality here + + align:start position:0% +so where did I get this inequality here + + + align:start position:0% +so where did I get this inequality here +why do I know that to R B is less than + + align:start position:0% +why do I know that to R B is less than + + + align:start position:0% +why do I know that to R B is less than +or equal to 2 n yes + + align:start position:0% +or equal to 2 n yes + + + align:start position:0% +or equal to 2 n yes +yes you know that n is greater than or + + align:start position:0% +yes you know that n is greater than or + + + align:start position:0% +yes you know that n is greater than or +equal to BR by this assumption up here + + align:start position:0% +equal to BR by this assumption up here + + + align:start position:0% +equal to BR by this assumption up here +so therefore RB is less than or equal to + + align:start position:0% +so therefore RB is less than or equal to + + + align:start position:0% +so therefore RB is less than or equal to +N and then NB plus 2n be just sums up to + + align:start position:0% +N and then NB plus 2n be just sums up to + + + align:start position:0% +N and then NB plus 2n be just sums up to +3 and B so in the worst case we're gonna + + align:start position:0% +3 and B so in the worst case we're gonna + + + align:start position:0% +3 and B so in the worst case we're gonna +incur 3 and over B cache misses okay so + + align:start position:0% +incur 3 and over B cache misses okay so + + + align:start position:0% +incur 3 and over B cache misses okay so +any questions on this cache miss lemma + + align:start position:0% + + + + align:start position:0% + +so important thing to remember here is + + align:start position:0% +so important thing to remember here is + + + align:start position:0% +so important thing to remember here is +that if you're if you have a whole bunch + + align:start position:0% +that if you're if you have a whole bunch + + + align:start position:0% +that if you're if you have a whole bunch +of data segments and the average length + + align:start position:0% +of data segments and the average length + + + align:start position:0% +of data segments and the average length +of your segments is large enough bigger + + align:start position:0% +of your segments is large enough bigger + + + align:start position:0% +of your segments is large enough bigger +than a cache block size that you can + + align:start position:0% +than a cache block size that you can + + + align:start position:0% +than a cache block size that you can +access all of these segments just like + + align:start position:0% +access all of these segments just like + + + align:start position:0% +access all of these segments just like +just like a single array it only + + align:start position:0% +just like a single array it only + + + align:start position:0% +just like a single array it only +increases the number of cache misses by + + align:start position:0% +increases the number of cache misses by + + + align:start position:0% +increases the number of cache misses by +a constant factor and if you're doing an + + align:start position:0% +a constant factor and if you're doing an + + + align:start position:0% +a constant factor and if you're doing an +asymptotic analysis then it doesn't + + align:start position:0% +asymptotic analysis then it doesn't + + + align:start position:0% +asymptotic analysis then it doesn't +matter so we're gonna be using this + + align:start position:0% +matter so we're gonna be using this + + + align:start position:0% +matter so we're gonna be using this +cache miss lemma later on when we + + align:start position:0% +cache miss lemma later on when we + + + align:start position:0% +cache miss lemma later on when we +analyze algorithms ok so another + + align:start position:0% +analyze algorithms ok so another + + + align:start position:0% +analyze algorithms ok so another +assumption that we're gonna need is + + align:start position:0% +assumption that we're gonna need is + + + align:start position:0% +assumption that we're gonna need is +called the tall cache assumption and the + + align:start position:0% +called the tall cache assumption and the + + + align:start position:0% +called the tall cache assumption and the +tall cache assumption basically says + + align:start position:0% +tall cache assumption basically says + + + align:start position:0% +tall cache assumption basically says +that the cache is taller than it is wide + + align:start position:0% +that the cache is taller than it is wide + + + align:start position:0% +that the cache is taller than it is wide +so says that B squared is less than cm + + align:start position:0% +so says that B squared is less than cm + + + align:start position:0% +so says that B squared is less than cm +for some sufficiently small constant C + + align:start position:0% +for some sufficiently small constant C + + + align:start position:0% +for some sufficiently small constant C +less than or equal to 1 so in other + + align:start position:0% +less than or equal to 1 so in other + + + align:start position:0% +less than or equal to 1 so in other +words it says that the number of cache + + align:start position:0% +words it says that the number of cache + + + align:start position:0% +words it says that the number of cache +lines and over B you have is going to be + + align:start position:0% +lines and over B you have is going to be + + + align:start position:0% +lines and over B you have is going to be +bigger than B and this tall cache + + align:start position:0% +bigger than B and this tall cache + + + align:start position:0% +bigger than B and this tall cache +assumption is usually satisfied in + + align:start position:0% +assumption is usually satisfied in + + + align:start position:0% +assumption is usually satisfied in +practice so here the cache line sizes + + align:start position:0% +practice so here the cache line sizes + + + align:start position:0% +practice so here the cache line sizes +and the cache sizes on the machines that + + align:start position:0% +and the cache sizes on the machines that + + + align:start position:0% +and the cache sizes on the machines that +we're using so cache line size is 64 + + align:start position:0% +we're using so cache line size is 64 + + + align:start position:0% +we're using so cache line size is 64 +bytes and the l1 cache size is 32 + + align:start position:0% +bytes and the l1 cache size is 32 + + + align:start position:0% +bytes and the l1 cache size is 32 +kilobytes so 64 bytes squared that's 2 + + align:start position:0% +kilobytes so 64 bytes squared that's 2 + + + align:start position:0% +kilobytes so 64 bytes squared that's 2 +to 12 and 32 kilobytes less to 215th + + align:start position:0% +to 12 and 32 kilobytes less to 215th + + + align:start position:0% +to 12 and 32 kilobytes less to 215th +bytes so 2 to 12 is less than 2 to 15 so + + align:start position:0% +bytes so 2 to 12 is less than 2 to 15 so + + + align:start position:0% +bytes so 2 to 12 is less than 2 to 15 so +it satisfies a tall cache assumption and + + align:start position:0% +it satisfies a tall cache assumption and + + + align:start position:0% +it satisfies a tall cache assumption and +as we go up the memory hierarchy the + + align:start position:0% +as we go up the memory hierarchy the + + + align:start position:0% +as we go up the memory hierarchy the +cache size increases but the cache line + + align:start position:0% +cache size increases but the cache line + + + align:start position:0% +cache size increases but the cache line +length stays the same so + + align:start position:0% +length stays the same so + + + align:start position:0% +length stays the same so +the cash has become even taller as we + + align:start position:0% +the cash has become even taller as we + + + align:start position:0% +the cash has become even taller as we +move up the memory hierarchy so let's + + align:start position:0% +move up the memory hierarchy so let's + + + align:start position:0% +move up the memory hierarchy so let's +see why this tall cache assumption is + + align:start position:0% +see why this tall cache assumption is + + + align:start position:0% +see why this tall cache assumption is +going to be useful to see that we're + + align:start position:0% +going to be useful to see that we're + + + align:start position:0% +going to be useful to see that we're +going to look at what's wrong with a + + align:start position:0% +going to look at what's wrong with a + + + align:start position:0% +going to look at what's wrong with a +short cache + + align:start position:0% +short cache + + + align:start position:0% +short cache +so in the short cache our lines are + + align:start position:0% +so in the short cache our lines are + + + align:start position:0% +so in the short cache our lines are +going to be very wide and they're wider + + align:start position:0% +going to be very wide and they're wider + + + align:start position:0% +going to be very wide and they're wider +than the number of lines that we can + + align:start position:0% +than the number of lines that we can + + + align:start position:0% +than the number of lines that we can +have in our cache and let's say we're + + align:start position:0% +have in our cache and let's say we're + + + align:start position:0% +have in our cache and let's say we're +working with an N by n sub matrix sort + + align:start position:0% +working with an N by n sub matrix sort + + + align:start position:0% +working with an N by n sub matrix sort +and row major order if you have a short + + align:start position:0% +and row major order if you have a short + + + align:start position:0% +and row major order if you have a short +cache then even if n squared is less + + align:start position:0% +cache then even if n squared is less + + + align:start position:0% +cache then even if n squared is less +than cm meaning that you can fit all the + + align:start position:0% +than cm meaning that you can fit all the + + + align:start position:0% +than cm meaning that you can fit all the +bytes of the sub matrix in cache you + + align:start position:0% +bytes of the sub matrix in cache you + + + align:start position:0% +bytes of the sub matrix in cache you +might still not be able to fit it into a + + align:start position:0% +might still not be able to fit it into a + + + align:start position:0% +might still not be able to fit it into a +short cache and this picture sort of + + align:start position:0% +short cache and this picture sort of + + + align:start position:0% +short cache and this picture sort of +illustrates this so we have n rows here + + align:start position:0% +illustrates this so we have n rows here + + + align:start position:0% +illustrates this so we have n rows here +but we can only fit M over B of the rows + + align:start position:0% +but we can only fit M over B of the rows + + + align:start position:0% +but we can only fit M over B of the rows +in the cache because the the cache lines + + align:start position:0% +in the cache because the the cache lines + + + align:start position:0% +in the cache because the the cache lines +are so long and we're actually wasting a + + align:start position:0% +are so long and we're actually wasting a + + + align:start position:0% +are so long and we're actually wasting a +lot of space on each of the cache lines + + align:start position:0% +lot of space on each of the cache lines + + + align:start position:0% +lot of space on each of the cache lines +we're only using a very small fraction + + align:start position:0% +we're only using a very small fraction + + + align:start position:0% +we're only using a very small fraction +of each cache line to store the row of + + align:start position:0% +of each cache line to store the row of + + + align:start position:0% +of each cache line to store the row of +this sub matrix if we if this were the + + align:start position:0% +this sub matrix if we if this were the + + + align:start position:0% +this sub matrix if we if this were the +entire matrix then it would actually be + + align:start position:0% +entire matrix then it would actually be + + + align:start position:0% +entire matrix then it would actually be +okay because consecutive rows are going + + align:start position:0% +okay because consecutive rows are going + + + align:start position:0% +okay because consecutive rows are going +to be placed together consecutively in + + align:start position:0% +to be placed together consecutively in + + + align:start position:0% +to be placed together consecutively in +memory but if this is a sub matrix then + + align:start position:0% +memory but if this is a sub matrix then + + + align:start position:0% +memory but if this is a sub matrix then +we can't be guaranteed that the next row + + align:start position:0% +we can't be guaranteed that the next row + + + align:start position:0% +we can't be guaranteed that the next row +is going to be placed right after the + + align:start position:0% +is going to be placed right after the + + + align:start position:0% +is going to be placed right after the +current row and oftentimes we have to + + align:start position:0% +current row and oftentimes we have to + + + align:start position:0% +current row and oftentimes we have to +deal with sub matrices when we're doing + + align:start position:0% +deal with sub matrices when we're doing + + + align:start position:0% +deal with sub matrices when we're doing +recursive matrix algorithms okay so this + + align:start position:0% +recursive matrix algorithms okay so this + + + align:start position:0% +recursive matrix algorithms okay so this +is what's wrong with short caches and + + align:start position:0% +is what's wrong with short caches and + + + align:start position:0% +is what's wrong with short caches and +that's why we want to assume the tall + + align:start position:0% +that's why we want to assume the tall + + + align:start position:0% +that's why we want to assume the tall +cache assumption and we can assume that + + align:start position:0% +cache assumption and we can assume that + + + align:start position:0% +cache assumption and we can assume that +because it's usually satisfied in + + align:start position:0% +because it's usually satisfied in + + + align:start position:0% +because it's usually satisfied in +practice the TLB actually tends to be + + align:start position:0% +practice the TLB actually tends to be + + + align:start position:0% +practice the TLB actually tends to be +short it only has a couple entries so it + + align:start position:0% +short it only has a couple entries so it + + + align:start position:0% +short it only has a couple entries so it +might not satisfy the tall cache + + align:start position:0% +might not satisfy the tall cache + + + align:start position:0% +might not satisfy the tall cache +assumption but all the other caches will + + align:start position:0% +assumption but all the other caches will + + + align:start position:0% +assumption but all the other caches will +satisfy this assumption any questions + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so here's another llama that's going to + + align:start position:0% +so here's another llama that's going to + + + align:start position:0% +so here's another llama that's going to +be useful this is called the sub-matrix + + align:start position:0% +be useful this is called the sub-matrix + + + align:start position:0% +be useful this is called the sub-matrix +caching llama so suppose that we have an + + align:start position:0% +caching llama so suppose that we have an + + + align:start position:0% +caching llama so suppose that we have an +N by n matrix a and it's read into a + + align:start position:0% +N by n matrix a and it's read into a + + + align:start position:0% +N by n matrix a and it's read into a +tall cache that satisfies B squared less + + align:start position:0% +tall cache that satisfies B squared less + + + align:start position:0% +tall cache that satisfies B squared less +than cm for some constant C less than + + align:start position:0% +than cm for some constant C less than + + + align:start position:0% +than cm for some constant C less than +equal to 1 and suppose that N squared is + + align:start position:0% +equal to 1 and suppose that N squared is + + + align:start position:0% +equal to 1 and suppose that N squared is +less than M over 3 but it's greater than + + align:start position:0% +less than M over 3 but it's greater than + + + align:start position:0% +less than M over 3 but it's greater than +or equal to CM then a is going to fit + + align:start position:0% +or equal to CM then a is going to fit + + + align:start position:0% +or equal to CM then a is going to fit +into cache in a number of cache misses + + align:start position:0% +into cache in a number of cache misses + + + align:start position:0% +into cache in a number of cache misses +required to read all of ADEs elements + + align:start position:0% +required to read all of ADEs elements + + + align:start position:0% +required to read all of ADEs elements +into cache is at most 3 n squared over B + + align:start position:0% + + + + align:start position:0% + +ok so let's see why this is true so + + align:start position:0% +ok so let's see why this is true so + + + align:start position:0% +ok so let's see why this is true so +we're gonna let big n denote the total + + align:start position:0% +we're gonna let big n denote the total + + + align:start position:0% +we're gonna let big n denote the total +number of bytes that we need to access + + align:start position:0% +number of bytes that we need to access + + + align:start position:0% +number of bytes that we need to access +so big n is going to be equal to N + + align:start position:0% +so big n is going to be equal to N + + + align:start position:0% +so big n is going to be equal to N +squared and we're gonna use the cache + + align:start position:0% +squared and we're gonna use the cache + + + align:start position:0% +squared and we're gonna use the cache +miss lemma which says that if the + + align:start position:0% +miss lemma which says that if the + + + align:start position:0% +miss lemma which says that if the +average length of our segments is large + + align:start position:0% +average length of our segments is large + + + align:start position:0% +average length of our segments is large +enough that we can read all the segments + + align:start position:0% +enough that we can read all the segments + + + align:start position:0% +enough that we can read all the segments +in just like it were a single contiguous + + align:start position:0% +in just like it were a single contiguous + + + align:start position:0% +in just like it were a single contiguous +array so the lengths of our segments + + align:start position:0% +array so the lengths of our segments + + + align:start position:0% +array so the lengths of our segments +here are going to be little n so R is + + align:start position:0% +here are going to be little n so R is + + + align:start position:0% +here are going to be little n so R is +gonna be little N and that's also the + + align:start position:0% +gonna be little N and that's also the + + + align:start position:0% +gonna be little N and that's also the +number of segments is going to be little + + align:start position:0% +number of segments is going to be little + + + align:start position:0% +number of segments is going to be little +and and the segment length is also going + + align:start position:0% +and and the segment length is also going + + + align:start position:0% +and and the segment length is also going +to be little ends since we're working + + align:start position:0% +to be little ends since we're working + + + align:start position:0% +to be little ends since we're working +with a square sub-matrix here and then + + align:start position:0% +with a square sub-matrix here and then + + + align:start position:0% +with a square sub-matrix here and then +we also have that the cache block size B + + align:start position:0% +we also have that the cache block size B + + + align:start position:0% +we also have that the cache block size B +is less than or equal to N and that's + + align:start position:0% +is less than or equal to N and that's + + + align:start position:0% +is less than or equal to N and that's +equal to big and over R and where do we + + align:start position:0% +equal to big and over R and where do we + + + align:start position:0% +equal to big and over R and where do we +get this property that B is less than or + + align:start position:0% +get this property that B is less than or + + + align:start position:0% +get this property that B is less than or +equal to n so I made some assumptions up + + align:start position:0% +equal to n so I made some assumptions up + + + align:start position:0% +equal to n so I made some assumptions up +here where I can use to infer that B is + + align:start position:0% +here where I can use to infer that B is + + + align:start position:0% +here where I can use to infer that B is +less than or equal to n does anybody see + + align:start position:0% +less than or equal to n does anybody see + + + align:start position:0% +less than or equal to n does anybody see +where yeah + + align:start position:0% + + + + align:start position:0% + +yeah so I know that B squared is less + + align:start position:0% +yeah so I know that B squared is less + + + align:start position:0% +yeah so I know that B squared is less +than cm cm is less than or equal to n + + align:start position:0% +than cm cm is less than or equal to n + + + align:start position:0% +than cm cm is less than or equal to n +square so therefore B squared is less + + align:start position:0% +square so therefore B squared is less + + + align:start position:0% +square so therefore B squared is less +than N squared in B is less than n so so + + align:start position:0% +than N squared in B is less than n so so + + + align:start position:0% +than N squared in B is less than n so so +now I also have that n is less than M + + align:start position:0% +now I also have that n is less than M + + + align:start position:0% +now I also have that n is less than M +over 3 just by assumption and therefore + + align:start position:0% +over 3 just by assumption and therefore + + + align:start position:0% +over 3 just by assumption and therefore +I can use the cache miss lemma so the + + align:start position:0% +I can use the cache miss lemma so the + + + align:start position:0% +I can use the cache miss lemma so the +cache miss lemma tells me that I only + + align:start position:0% +cache miss lemma tells me that I only + + + align:start position:0% +cache miss lemma tells me that I only +need a total of 3 N squared over B cache + + align:start position:0% +need a total of 3 N squared over B cache + + + align:start position:0% +need a total of 3 N squared over B cache +misses to read this whole thing in any + + align:start position:0% +misses to read this whole thing in any + + + align:start position:0% +misses to read this whole thing in any +questions on the sub-matrix hashing + + align:start position:0% +questions on the sub-matrix hashing + + + align:start position:0% +questions on the sub-matrix hashing +lemma + + align:start position:0% + + + + align:start position:0% + +okay so now let's analyze matrix + + align:start position:0% +okay so now let's analyze matrix + + + align:start position:0% +okay so now let's analyze matrix +multiplication so how many of you have + + align:start position:0% +multiplication so how many of you have + + + align:start position:0% +multiplication so how many of you have +seen matrix multiplication before so a + + align:start position:0% +seen matrix multiplication before so a + + + align:start position:0% +seen matrix multiplication before so a +couple of you okay so here's what the + + align:start position:0% +couple of you okay so here's what the + + + align:start position:0% +couple of you okay so here's what the +code looks like for the standard cubic + + align:start position:0% +code looks like for the standard cubic + + + align:start position:0% +code looks like for the standard cubic +work matrix multiplication algorithm so + + align:start position:0% +work matrix multiplication algorithm so + + + align:start position:0% +work matrix multiplication algorithm so +we have two input matrices a and B and + + align:start position:0% +we have two input matrices a and B and + + + align:start position:0% +we have two input matrices a and B and +we're gonna store the result in C and + + align:start position:0% +we're gonna store the result in C and + + + align:start position:0% +we're gonna store the result in C and +the height in the width of our matrix is + + align:start position:0% +the height in the width of our matrix is + + + align:start position:0% +the height in the width of our matrix is +n we're just going to deal with square + + align:start position:0% +n we're just going to deal with square + + + align:start position:0% +n we're just going to deal with square +matrices here but what I'm going to talk + + align:start position:0% +matrices here but what I'm going to talk + + + align:start position:0% +matrices here but what I'm going to talk +about also extends to non square + + align:start position:0% +about also extends to non square + + + align:start position:0% +about also extends to non square +matrices and then we just have three + + align:start position:0% +matrices and then we just have three + + + align:start position:0% +matrices and then we just have three +loops here we're going to loop through I + + align:start position:0% +loops here we're going to loop through I + + + align:start position:0% +loops here we're going to loop through I +from 0 to n minus 1 J from 0 to n minus + + align:start position:0% +from 0 to n minus 1 J from 0 to n minus + + + align:start position:0% +from 0 to n minus 1 J from 0 to n minus +1 and K from 0 to n minus 1 and then + + align:start position:0% +1 and K from 0 to n minus 1 and then + + + align:start position:0% +1 and K from 0 to n minus 1 and then +we're gonna let C of I n plus J be + + align:start position:0% +we're gonna let C of I n plus J be + + + align:start position:0% +we're gonna let C of I n plus J be +incremented by a of I n plus K times B + + align:start position:0% +incremented by a of I n plus K times B + + + align:start position:0% +incremented by a of I n plus K times B +of K n plus J so this is just the + + align:start position:0% +of K n plus J so this is just the + + + align:start position:0% +of K n plus J so this is just the +standard code for matrix multiply so + + align:start position:0% +standard code for matrix multiply so + + + align:start position:0% +standard code for matrix multiply so +what's the work of this algorithm should + + align:start position:0% + + + + align:start position:0% + +be all should be review for all of you + + align:start position:0% +be all should be review for all of you + + + align:start position:0% +be all should be review for all of you +and cubed + + align:start position:0% + + + + align:start position:0% + +okay so now let's analyze the number of + + align:start position:0% +okay so now let's analyze the number of + + + align:start position:0% +okay so now let's analyze the number of +cache misses this algorithm is going to + + align:start position:0% +cache misses this algorithm is going to + + + align:start position:0% +cache misses this algorithm is going to +incur and again we're gonna assume that + + align:start position:0% +incur and again we're gonna assume that + + + align:start position:0% +incur and again we're gonna assume that +the matrix is in row major order and we + + align:start position:0% +the matrix is in row major order and we + + + align:start position:0% +the matrix is in row major order and we +satisfy the tall cache assumption we're + + align:start position:0% +satisfy the tall cache assumption we're + + + align:start position:0% +satisfy the tall cache assumption we're +also going to analyze the number of + + align:start position:0% +also going to analyze the number of + + + align:start position:0% +also going to analyze the number of +cache misses in matrix B because it + + align:start position:0% +cache misses in matrix B because it + + + align:start position:0% +cache misses in matrix B because it +turns out that the number of cache + + align:start position:0% +turns out that the number of cache + + + align:start position:0% +turns out that the number of cache +misses incurred by matrix B is going to + + align:start position:0% +misses incurred by matrix B is going to + + + align:start position:0% +misses incurred by matrix B is going to +dominate the number of cache misses + + align:start position:0% +dominate the number of cache misses + + + align:start position:0% +dominate the number of cache misses +overall in there are three cases we need + + align:start position:0% +overall in there are three cases we need + + + align:start position:0% +overall in there are three cases we need +to consider the first case is when n is + + align:start position:0% +to consider the first case is when n is + + + align:start position:0% +to consider the first case is when n is +greater than C M over B for some + + align:start position:0% +greater than C M over B for some + + + align:start position:0% +greater than C M over B for some +constant C and we're gonna analyze + + align:start position:0% +constant C and we're gonna analyze + + + align:start position:0% +constant C and we're gonna analyze +matrix B as I said and we're also going + + align:start position:0% +matrix B as I said and we're also going + + + align:start position:0% +matrix B as I said and we're also going +to assume LRU because we can if you + + align:start position:0% +to assume LRU because we can if you + + + align:start position:0% +to assume LRU because we can if you +recall the LRU lemma it says that + + align:start position:0% +recall the LRU lemma it says that + + + align:start position:0% +recall the LRU lemma it says that +whatever we analyzed using the LRU is + + align:start position:0% +whatever we analyzed using the LRU is + + + align:start position:0% +whatever we analyzed using the LRU is +just going to be a constant factor + + align:start position:0% +just going to be a constant factor + + + align:start position:0% +just going to be a constant factor +within what we analyzed using the ideal + + align:start position:0% +within what we analyzed using the ideal + + + align:start position:0% +within what we analyzed using the ideal +cache so so to do this matrix + + align:start position:0% +cache so so to do this matrix + + + align:start position:0% +cache so so to do this matrix +multiplication I'm going to go through + + align:start position:0% +multiplication I'm going to go through + + + align:start position:0% +multiplication I'm going to go through +one row of a and one column of B and do + + align:start position:0% +one row of a and one column of B and do + + + align:start position:0% +one row of a and one column of B and do +the dot product there this is what + + align:start position:0% +the dot product there this is what + + + align:start position:0% +the dot product there this is what +happens in the innermost loop and how + + align:start position:0% +happens in the innermost loop and how + + + align:start position:0% +happens in the innermost loop and how +many cache misses am I going to incur + + align:start position:0% +many cache misses am I going to incur + + + align:start position:0% +many cache misses am I going to incur +when I go down one column of B here so + + align:start position:0% +when I go down one column of B here so + + + align:start position:0% +when I go down one column of B here so +here I have the case where n is greater + + align:start position:0% +here I have the case where n is greater + + + align:start position:0% +here I have the case where n is greater +than M over B so I can't fit all of I + + align:start position:0% +than M over B so I can't fit all of I + + + align:start position:0% +than M over B so I can't fit all of I +can't fit one block from each row into + + align:start position:0% +can't fit one block from each row into + + + align:start position:0% +can't fit one block from each row into +the cache so how many cache misses do I + + align:start position:0% +the cache so how many cache misses do I + + + align:start position:0% +the cache so how many cache misses do I +have the first time I go down a column + + align:start position:0% +have the first time I go down a column + + + align:start position:0% +have the first time I go down a column +of B so how many rows of B do I have and + + align:start position:0% +of B so how many rows of B do I have and + + + align:start position:0% +of B so how many rows of B do I have and +yeah and how many cache misses do I need + + align:start position:0% +yeah and how many cache misses do I need + + + align:start position:0% +yeah and how many cache misses do I need +for each row one so in total I'm going + + align:start position:0% +for each row one so in total I'm going + + + align:start position:0% +for each row one so in total I'm going +to need n cache misses for the first + + align:start position:0% +to need n cache misses for the first + + + align:start position:0% +to need n cache misses for the first +column of B what about the second column + + align:start position:0% +column of B what about the second column + + + align:start position:0% +column of B what about the second column +of B + + align:start position:0% + + + + align:start position:0% + +so recall that I'm assuming the LRU + + align:start position:0% +so recall that I'm assuming the LRU + + + align:start position:0% +so recall that I'm assuming the LRU +replacement policy here so when the + + align:start position:0% +replacement policy here so when the + + + align:start position:0% +replacement policy here so when the +cache is full + + align:start position:0% +cache is full + + + align:start position:0% +cache is full +I'm gonna evict the thing that was least + + align:start position:0% +I'm gonna evict the thing that was least + + + align:start position:0% +I'm gonna evict the thing that was least +recently used used the furthest in the + + align:start position:0% +recently used used the furthest in the + + + align:start position:0% +recently used used the furthest in the +past + + align:start position:0% + + + + align:start position:0% + +sorry could you repeat that yes it's + + align:start position:0% +sorry could you repeat that yes it's + + + align:start position:0% +sorry could you repeat that yes it's +still gonna be n why is that + + align:start position:0% + + + + align:start position:0% + +yeah so it's still gonna be n because I + + align:start position:0% +yeah so it's still gonna be n because I + + + align:start position:0% +yeah so it's still gonna be n because I +can't fit one cache block from each row + + align:start position:0% +can't fit one cache block from each row + + + align:start position:0% +can't fit one cache block from each row +into my cache and by the time I get back + + align:start position:0% +into my cache and by the time I get back + + + align:start position:0% +into my cache and by the time I get back +to the top of my matrix B the top block + + align:start position:0% +to the top of my matrix B the top block + + + align:start position:0% +to the top of my matrix B the top block +has already been evicted from the cache + + align:start position:0% +has already been evicted from the cache + + + align:start position:0% +has already been evicted from the cache +and I have to load it back in and this + + align:start position:0% +and I have to load it back in and this + + + align:start position:0% +and I have to load it back in and this +is the same for every other block that I + + align:start position:0% +is the same for every other block that I + + + align:start position:0% +is the same for every other block that I +access I'm again gonna need n cache + + align:start position:0% +access I'm again gonna need n cache + + + align:start position:0% +access I'm again gonna need n cache +misses for the second column of B and + + align:start position:0% +misses for the second column of B and + + + align:start position:0% +misses for the second column of B and +this is going to be the same for all the + + align:start position:0% +this is going to be the same for all the + + + align:start position:0% +this is going to be the same for all the +columns of B and I have to do this again + + align:start position:0% +columns of B and I have to do this again + + + align:start position:0% +columns of B and I have to do this again +for the second row of a so in total I'm + + align:start position:0% +for the second row of a so in total I'm + + + align:start position:0% +for the second row of a so in total I'm +going to need theta of n cubed number of + + align:start position:0% +going to need theta of n cubed number of + + + align:start position:0% +going to need theta of n cubed number of +cache misses and this is one cache miss + + align:start position:0% +cache misses and this is one cache miss + + + align:start position:0% +cache misses and this is one cache miss +per per entry that I access in B and + + align:start position:0% +per per entry that I access in B and + + + align:start position:0% +per per entry that I access in B and +this is not very good because the total + + align:start position:0% +this is not very good because the total + + + align:start position:0% +this is not very good because the total +work was also theta of n cube so I'm not + + align:start position:0% +work was also theta of n cube so I'm not + + + align:start position:0% +work was also theta of n cube so I'm not +gaining anything from having any + + align:start position:0% +gaining anything from having any + + + align:start position:0% +gaining anything from having any +locality in this in this algorithm here + + align:start position:0% +locality in this in this algorithm here + + + align:start position:0% +locality in this in this algorithm here +so any questions on this analysis so + + align:start position:0% +so any questions on this analysis so + + + align:start position:0% +so any questions on this analysis so +this is just a case one let's look at + + align:start position:0% +this is just a case one let's look at + + + align:start position:0% +this is just a case one let's look at +case two so in this case n is less than + + align:start position:0% +case two so in this case n is less than + + + align:start position:0% +case two so in this case n is less than +C M over B so I can fit one block from + + align:start position:0% +C M over B so I can fit one block from + + + align:start position:0% +C M over B so I can fit one block from +each row of B into cache and then n is + + align:start position:0% +each row of B into cache and then n is + + + align:start position:0% +each row of B into cache and then n is +also greater than another constant C + + align:start position:0% +also greater than another constant C + + + align:start position:0% +also greater than another constant C +prime times square root of M so I can't + + align:start position:0% +prime times square root of M so I can't + + + align:start position:0% +prime times square root of M so I can't +fit the whole matrix into cache and + + align:start position:0% +fit the whole matrix into cache and + + + align:start position:0% +fit the whole matrix into cache and +again let's analyze the number of cache + + align:start position:0% +again let's analyze the number of cache + + + align:start position:0% +again let's analyze the number of cache +misses incurred by accessing be assuming + + align:start position:0% +misses incurred by accessing be assuming + + + align:start position:0% +misses incurred by accessing be assuming +LRU so how many cache misses am I going + + align:start position:0% +LRU so how many cache misses am I going + + + align:start position:0% +LRU so how many cache misses am I going +to incur for the first column of B and + + align:start position:0% +to incur for the first column of B and + + + align:start position:0% +to incur for the first column of B and +so the same as before what about the + + align:start position:0% +so the same as before what about the + + + align:start position:0% +so the same as before what about the +second column of B so by the time I get + + align:start position:0% +second column of B so by the time I get + + + align:start position:0% +second column of B so by the time I get +to the beginning of the beginning of the + + align:start position:0% +to the beginning of the beginning of the + + + align:start position:0% +to the beginning of the beginning of the +matrix here is the top block going to be + + align:start position:0% +matrix here is the top block going to be + + + align:start position:0% +matrix here is the top block going to be +in cache so who thinks the block is + + align:start position:0% +in cache so who thinks the block is + + + align:start position:0% +in cache so who thinks the block is +still gonna be in cache when I get back + + align:start position:0% +still gonna be in cache when I get back + + + align:start position:0% +still gonna be in cache when I get back +to the beginning yeah so a couple of + + align:start position:0% +to the beginning yeah so a couple of + + + align:start position:0% +to the beginning yeah so a couple of +people who think is gonna be out of + + align:start position:0% +people who think is gonna be out of + + + align:start position:0% +people who think is gonna be out of +cache okay so turns out it is going to + + align:start position:0% +cache okay so turns out it is going to + + + align:start position:0% +cache okay so turns out it is going to +be in cache because I can fit one block + + align:start position:0% +be in cache because I can fit one block + + + align:start position:0% +be in cache because I can fit one block +for every row of B into my + + align:start position:0% +for every row of B into my + + + align:start position:0% +for every row of B into my +since I have n less than cm over B so + + align:start position:0% +since I have n less than cm over B so + + + align:start position:0% +since I have n less than cm over B so +therefore when I get to the beginning of + + align:start position:0% +therefore when I get to the beginning of + + + align:start position:0% +therefore when I get to the beginning of +the second column that block is still + + align:start position:0% +the second column that block is still + + + align:start position:0% +the second column that block is still +gonna be in cash because I loaded it in + + align:start position:0% +gonna be in cash because I loaded it in + + + align:start position:0% +gonna be in cash because I loaded it in +when I was accessing the first column so + + align:start position:0% +when I was accessing the first column so + + + align:start position:0% +when I was accessing the first column so +I'm not gonna incur any cash misses for + + align:start position:0% +I'm not gonna incur any cash misses for + + + align:start position:0% +I'm not gonna incur any cash misses for +the second column and in general if if + + align:start position:0% +the second column and in general if if + + + align:start position:0% +the second column and in general if if +my if I can fit B columns or some + + align:start position:0% +my if I can fit B columns or some + + + align:start position:0% +my if I can fit B columns or some +constant times B columns in in into cash + + align:start position:0% +constant times B columns in in into cash + + + align:start position:0% +constant times B columns in in into cash +then I can reduce the number of cache + + align:start position:0% +then I can reduce the number of cache + + + align:start position:0% +then I can reduce the number of cache +misses I have by a factor of B so I only + + align:start position:0% +misses I have by a factor of B so I only + + + align:start position:0% +misses I have by a factor of B so I only +need to incur a cache miss the first + + align:start position:0% +need to incur a cache miss the first + + + align:start position:0% +need to incur a cache miss the first +time I access a block and not for all + + align:start position:0% +time I access a block and not for all + + + align:start position:0% +time I access a block and not for all +the subsequent accesses and the same is + + align:start position:0% +the subsequent accesses and the same is + + + align:start position:0% +the subsequent accesses and the same is +true for the second row of a and since I + + align:start position:0% +true for the second row of a and since I + + + align:start position:0% +true for the second row of a and since I +have n rows of a I'm gonna have n times + + align:start position:0% +have n rows of a I'm gonna have n times + + + align:start position:0% +have n rows of a I'm gonna have n times +theta of N squared over B cache misses + + align:start position:0% +theta of N squared over B cache misses + + + align:start position:0% +theta of N squared over B cache misses +for each row of a I'm gonna incur and + + align:start position:0% +for each row of a I'm gonna incur and + + + align:start position:0% +for each row of a I'm gonna incur and +squared over B cache misses + + align:start position:0% +squared over B cache misses + + + align:start position:0% +squared over B cache misses +so the overall number of cache misses is + + align:start position:0% +so the overall number of cache misses is + + + align:start position:0% +so the overall number of cache misses is +and cubed over B and this is because + + align:start position:0% +and cubed over B and this is because + + + align:start position:0% +and cubed over B and this is because +inside matrix B I can exploit spatial + + align:start position:0% +inside matrix B I can exploit spatial + + + align:start position:0% +inside matrix B I can exploit spatial +locality once I load in a block I can + + align:start position:0% +locality once I load in a block I can + + + align:start position:0% +locality once I load in a block I can +reuse it the next time I traverse down a + + align:start position:0% +reuse it the next time I traverse down a + + + align:start position:0% +reuse it the next time I traverse down a +column that's nearby any questions on + + align:start position:0% +column that's nearby any questions on + + + align:start position:0% +column that's nearby any questions on +this analysis + + align:start position:0% + + + + align:start position:0% + +okay so let's look at the third case and + + align:start position:0% +okay so let's look at the third case and + + + align:start position:0% +okay so let's look at the third case and +here n is less than C prime times square + + align:start position:0% +here n is less than C prime times square + + + align:start position:0% +here n is less than C prime times square +root of M so this means that the entire + + align:start position:0% +root of M so this means that the entire + + + align:start position:0% +root of M so this means that the entire +matrix fits into cache so let's analyze + + align:start position:0% +matrix fits into cache so let's analyze + + + align:start position:0% +matrix fits into cache so let's analyze +the number of cache misses for matrix B + + align:start position:0% +the number of cache misses for matrix B + + + align:start position:0% +the number of cache misses for matrix B +again assuming LRU so how many cache + + align:start position:0% +again assuming LRU so how many cache + + + align:start position:0% +again assuming LRU so how many cache +misses do I have now so let's let's + + align:start position:0% +misses do I have now so let's let's + + + align:start position:0% +misses do I have now so let's let's +count the total number of cache misses I + + align:start position:0% +count the total number of cache misses I + + + align:start position:0% +count the total number of cache misses I +have for every time I go through a row + + align:start position:0% +have for every time I go through a row + + + align:start position:0% +have for every time I go through a row +of a yes yeah so the firt for the first + + align:start position:0% +of a yes yeah so the firt for the first + + + align:start position:0% +of a yes yeah so the firt for the first +column is going to be n what about the + + align:start position:0% +column is going to be n what about the + + + align:start position:0% +column is going to be n what about the +second column right so for the so + + align:start position:0% +second column right so for the so + + + align:start position:0% +second column right so for the so +basically for the first row of a the + + align:start position:0% +basically for the first row of a the + + + align:start position:0% +basically for the first row of a the +analysis is going to be the same as + + align:start position:0% +analysis is going to be the same as + + + align:start position:0% +analysis is going to be the same as +before I need n squared over B cache + + align:start position:0% +before I need n squared over B cache + + + align:start position:0% +before I need n squared over B cache +misses to load the cache in what about + + align:start position:0% +misses to load the cache in what about + + + align:start position:0% +misses to load the cache in what about +the second row of a how many cache + + align:start position:0% +the second row of a how many cache + + + align:start position:0% +the second row of a how many cache +misses am I going to incur + + align:start position:0% + + + + align:start position:0% + +yeah so for the second row of a I'm not + + align:start position:0% +yeah so for the second row of a I'm not + + + align:start position:0% +yeah so for the second row of a I'm not +gonna incur any cash misses because once + + align:start position:0% +gonna incur any cash misses because once + + + align:start position:0% +gonna incur any cash misses because once +I load B into cash + + align:start position:0% +I load B into cash + + + align:start position:0% +I load B into cash +it's gonna stay in cash because the + + align:start position:0% +it's gonna stay in cash because the + + + align:start position:0% +it's gonna stay in cash because the +entire matrix can fit in cash I assume + + align:start position:0% +entire matrix can fit in cash I assume + + + align:start position:0% +entire matrix can fit in cash I assume +that n is less than C prime times square + + align:start position:0% +that n is less than C prime times square + + + align:start position:0% +that n is less than C prime times square +root of M so total number of cache + + align:start position:0% +root of M so total number of cache + + + align:start position:0% +root of M so total number of cache +misses I need for matrix B is theta of n + + align:start position:0% +misses I need for matrix B is theta of n + + + align:start position:0% +misses I need for matrix B is theta of n +squared over B since everything fits in + + align:start position:0% +squared over B since everything fits in + + + align:start position:0% +squared over B since everything fits in +cache and I just applied the sub matrix + + align:start position:0% +cache and I just applied the sub matrix + + + align:start position:0% +cache and I just applied the sub matrix +caching lemma from before + + align:start position:0% + + + + align:start position:0% + +overall this is not a very good + + align:start position:0% +overall this is not a very good + + + align:start position:0% +overall this is not a very good +algorithm because as you recall in case + + align:start position:0% +algorithm because as you recall in case + + + align:start position:0% +algorithm because as you recall in case +one I needed a cubic cubic number of + + align:start position:0% +one I needed a cubic cubic number of + + + align:start position:0% +one I needed a cubic cubic number of +cache misses what happens if I swap the + + align:start position:0% +cache misses what happens if I swap the + + + align:start position:0% +cache misses what happens if I swap the +order of the inner two loops so recall + + align:start position:0% +order of the inner two loops so recall + + + align:start position:0% +order of the inner two loops so recall +that this was one of the optimizations + + align:start position:0% +that this was one of the optimizations + + + align:start position:0% +that this was one of the optimizations +in lecture one when Charles was talking + + align:start position:0% +in lecture one when Charles was talking + + + align:start position:0% +in lecture one when Charles was talking +about matrix multiplication and how to + + align:start position:0% +about matrix multiplication and how to + + + align:start position:0% +about matrix multiplication and how to +speed it up so if I swap the order of + + align:start position:0% +speed it up so if I swap the order of + + + align:start position:0% +speed it up so if I swap the order of +the two inner loops then then for every + + align:start position:0% +the two inner loops then then for every + + + align:start position:0% +the two inner loops then then for every +iteration what I'm doing is I'm actually + + align:start position:0% +iteration what I'm doing is I'm actually + + + align:start position:0% +iteration what I'm doing is I'm actually +going over a row of C in a row of B and + + align:start position:0% +going over a row of C in a row of B and + + + align:start position:0% +going over a row of C in a row of B and +a stays fixed inside the innermost + + align:start position:0% +a stays fixed inside the innermost + + + align:start position:0% +a stays fixed inside the innermost +iteration so now when I analyze the + + align:start position:0% +iteration so now when I analyze the + + + align:start position:0% +iteration so now when I analyze the +number of cache misses of matrix B + + align:start position:0% +number of cache misses of matrix B + + + align:start position:0% +number of cache misses of matrix B +assuming LRU I'm gonna benefit from + + align:start position:0% +assuming LRU I'm gonna benefit from + + + align:start position:0% +assuming LRU I'm gonna benefit from +spatial locality since I'm going row by + + align:start position:0% +spatial locality since I'm going row by + + + align:start position:0% +spatial locality since I'm going row by +row and the matrix is stored in row + + align:start position:0% +row and the matrix is stored in row + + + align:start position:0% +row and the matrix is stored in row +major order so across all of the rows + + align:start position:0% +major order so across all of the rows + + + align:start position:0% +major order so across all of the rows +I'm just going to require theta of n + + align:start position:0% +I'm just going to require theta of n + + + align:start position:0% +I'm just going to require theta of n +squared over B cache misses and I have + + align:start position:0% +squared over B cache misses and I have + + + align:start position:0% +squared over B cache misses and I have +to do this end times for the outer loop + + align:start position:0% +to do this end times for the outer loop + + + align:start position:0% +to do this end times for the outer loop +so in total I'm going to get theta of n + + align:start position:0% +so in total I'm going to get theta of n + + + align:start position:0% +so in total I'm going to get theta of n +cubed over B cache misses so if you swap + + align:start position:0% +cubed over B cache misses so if you swap + + + align:start position:0% +cubed over B cache misses so if you swap +the order of the inner two loops this + + align:start position:0% +the order of the inner two loops this + + + align:start position:0% +the order of the inner two loops this +significantly improves the locality of + + align:start position:0% +significantly improves the locality of + + + align:start position:0% +significantly improves the locality of +your algorithm and you can benefit from + + align:start position:0% +your algorithm and you can benefit from + + + align:start position:0% +your algorithm and you can benefit from +spatial locality and that's why we saw a + + align:start position:0% +spatial locality and that's why we saw a + + + align:start position:0% +spatial locality and that's why we saw a +significant performance improvement in + + align:start position:0% +significant performance improvement in + + + align:start position:0% +significant performance improvement in +the first lecture when we swapped the + + align:start position:0% +the first lecture when we swapped the + + + align:start position:0% +the first lecture when we swapped the +order of the loops any questions + + align:start position:0% + + + + align:start position:0% + +does anybody think we can do better than + + align:start position:0% +does anybody think we can do better than + + + align:start position:0% +does anybody think we can do better than +n cubed over B cache misses or you think + + align:start position:0% +n cubed over B cache misses or you think + + + align:start position:0% +n cubed over B cache misses or you think +that it's the best you can do so how + + align:start position:0% +that it's the best you can do so how + + + align:start position:0% +that it's the best you can do so how +many people think you can do better yeah + + align:start position:0% +many people think you can do better yeah + + + align:start position:0% +many people think you can do better yeah +and how many people think this is the + + align:start position:0% +and how many people think this is the + + + align:start position:0% +and how many people think this is the +best you can do okay and how many people + + align:start position:0% +best you can do okay and how many people + + + align:start position:0% +best you can do okay and how many people +don't care so turns out you can do + + align:start position:0% +don't care so turns out you can do + + + align:start position:0% +don't care so turns out you can do +better and we're gonna do better by + + align:start position:0% +better and we're gonna do better by + + + align:start position:0% +better and we're gonna do better by +using an optimization called tiling so + + align:start position:0% +using an optimization called tiling so + + + align:start position:0% +using an optimization called tiling so +how this is gonna work is instead of + + align:start position:0% +how this is gonna work is instead of + + + align:start position:0% +how this is gonna work is instead of +just having three for loops I'm gonna + + align:start position:0% +just having three for loops I'm gonna + + + align:start position:0% +just having three for loops I'm gonna +have six for loops and I'm gonna loop + + align:start position:0% +have six for loops and I'm gonna loop + + + align:start position:0% +have six for loops and I'm gonna loop +over tiles so I've got loop over s by s + + align:start position:0% +over tiles so I've got loop over s by s + + + align:start position:0% +over tiles so I've got loop over s by s +sub matrices and within each sub makes + + align:start position:0% +sub matrices and within each sub makes + + + align:start position:0% +sub matrices and within each sub makes +listing I'm gonna do all the computation + + align:start position:0% +listing I'm gonna do all the computation + + + align:start position:0% +listing I'm gonna do all the computation +I need for that sub matrix before moving + + align:start position:0% +I need for that sub matrix before moving + + + align:start position:0% +I need for that sub matrix before moving +on to the next sub matrix so the three + + align:start position:0% +on to the next sub matrix so the three + + + align:start position:0% +on to the next sub matrix so the three +innermost loops are going to loop inside + + align:start position:0% +innermost loops are going to loop inside + + + align:start position:0% +innermost loops are going to loop inside +a sub matrix and the three outermost + + align:start position:0% +a sub matrix and the three outermost + + + align:start position:0% +a sub matrix and the three outermost +loops are going to loop within the + + align:start position:0% +loops are going to loop within the + + + align:start position:0% +loops are going to loop within the +larger matrix one sub matrix at a time + + align:start position:0% +larger matrix one sub matrix at a time + + + align:start position:0% +larger matrix one sub matrix at a time +so let's analyze the work of this + + align:start position:0% +so let's analyze the work of this + + + align:start position:0% +so let's analyze the work of this +algorithm so the work that we need to do + + align:start position:0% +algorithm so the work that we need to do + + + align:start position:0% +algorithm so the work that we need to do +for a sub matrix of size s by s is going + + align:start position:0% +for a sub matrix of size s by s is going + + + align:start position:0% +for a sub matrix of size s by s is going +to be s cubed since that's just a bound + + align:start position:0% +to be s cubed since that's just a bound + + + align:start position:0% +to be s cubed since that's just a bound +for matrix multiplication and then a + + align:start position:0% +for matrix multiplication and then a + + + align:start position:0% +for matrix multiplication and then a +number of times I have to operate on sub + + align:start position:0% +number of times I have to operate on sub + + + align:start position:0% +number of times I have to operate on sub +matrices is going to be n over s cubed + + align:start position:0% +matrices is going to be n over s cubed + + + align:start position:0% +matrices is going to be n over s cubed +and you can see this if you just + + align:start position:0% +and you can see this if you just + + + align:start position:0% +and you can see this if you just +consider each sub matrix to be a single + + align:start position:0% +consider each sub matrix to be a single + + + align:start position:0% +consider each sub matrix to be a single +element and then using the same cubic + + align:start position:0% +element and then using the same cubic + + + align:start position:0% +element and then using the same cubic +work analysis on the smaller matrix so + + align:start position:0% +work analysis on the smaller matrix so + + + align:start position:0% +work analysis on the smaller matrix so +the work is n over s cubed times s cubed + + align:start position:0% +the work is n over s cubed times s cubed + + + align:start position:0% +the work is n over s cubed times s cubed +which is equal to theta n cube so the + + align:start position:0% +which is equal to theta n cube so the + + + align:start position:0% +which is equal to theta n cube so the +work of this tiled matrix multiplies the + + align:start position:0% +work of this tiled matrix multiplies the + + + align:start position:0% +work of this tiled matrix multiplies the +same as the version that didn't do + + align:start position:0% +same as the version that didn't do + + + align:start position:0% +same as the version that didn't do +tiling and now let's analyze the number + + align:start position:0% +tiling and now let's analyze the number + + + align:start position:0% +tiling and now let's analyze the number +of cache misses + + align:start position:0% + + + + align:start position:0% + +so we're gonna tune s so that the + + align:start position:0% +so we're gonna tune s so that the + + + align:start position:0% +so we're gonna tune s so that the +sub-matrices + + align:start position:0% +sub-matrices + + + align:start position:0% +sub-matrices +just fit into cash so we're gonna set s + + align:start position:0% +just fit into cash so we're gonna set s + + + align:start position:0% +just fit into cash so we're gonna set s +to be equal to theta of square root of M + + align:start position:0% +to be equal to theta of square root of M + + + align:start position:0% +to be equal to theta of square root of M +who actually need to make this like + + align:start position:0% +who actually need to make this like + + + align:start position:0% +who actually need to make this like +one-third square root of M because we + + align:start position:0% +one-third square root of M because we + + + align:start position:0% +one-third square root of M because we +need to fit three sub matrices in the + + align:start position:0% +need to fit three sub matrices in the + + + align:start position:0% +need to fit three sub matrices in the +cache but it's going to be some constant + + align:start position:0% +cache but it's going to be some constant + + + align:start position:0% +cache but it's going to be some constant +times square root of M the sub-matrix + + align:start position:0% +times square root of M the sub-matrix + + + align:start position:0% +times square root of M the sub-matrix +cashing leva implies that for each sub + + align:start position:0% +cashing leva implies that for each sub + + + align:start position:0% +cashing leva implies that for each sub +matrix + + align:start position:0% +matrix + + + align:start position:0% +matrix +we're gonna need s squared over B misses + + align:start position:0% +we're gonna need s squared over B misses + + + align:start position:0% +we're gonna need s squared over B misses +to load it in and once we load it into + + align:start position:0% +to load it in and once we load it into + + + align:start position:0% +to load it in and once we load it into +cash + + align:start position:0% +cash + + + align:start position:0% +cash +it fits entirely into cache so we can do + + align:start position:0% +it fits entirely into cache so we can do + + + align:start position:0% +it fits entirely into cache so we can do +all of our computations within cash and + + align:start position:0% +all of our computations within cash and + + + align:start position:0% +all of our computations within cash and +not incur any more cache misses so + + align:start position:0% +not incur any more cache misses so + + + align:start position:0% +not incur any more cache misses so +therefore the total number of cache + + align:start position:0% +therefore the total number of cache + + + align:start position:0% +therefore the total number of cache +misses we're going to incur it's going + + align:start position:0% +misses we're going to incur it's going + + + align:start position:0% +misses we're going to incur it's going +to be the number of subproblems which is + + align:start position:0% +to be the number of subproblems which is + + + align:start position:0% +to be the number of subproblems which is +n over s cubed and then the number of + + align:start position:0% +n over s cubed and then the number of + + + align:start position:0% +n over s cubed and then the number of +cache misses per subproblem which is s + + align:start position:0% +cache misses per subproblem which is s + + + align:start position:0% +cache misses per subproblem which is s +squared over B and if you multiply this + + align:start position:0% +squared over B and if you multiply this + + + align:start position:0% +squared over B and if you multiply this +out you're gonna get and cubed over B + + align:start position:0% +out you're gonna get and cubed over B + + + align:start position:0% +out you're gonna get and cubed over B +times square root of M so here I plugged + + align:start position:0% +times square root of M so here I plugged + + + align:start position:0% +times square root of M so here I plugged +in square root of M for s and this is a + + align:start position:0% +in square root of M for s and this is a + + + align:start position:0% +in square root of M for s and this is a +pretty cool result because it says that + + align:start position:0% +pretty cool result because it says that + + + align:start position:0% +pretty cool result because it says that +you can actually do better than the n + + align:start position:0% +you can actually do better than the n + + + align:start position:0% +you can actually do better than the n +cubed over B bound you can improve this + + align:start position:0% +cubed over B bound you can improve this + + + align:start position:0% +cubed over B bound you can improve this +bound by a factor of square root of M + + align:start position:0% +bound by a factor of square root of M + + + align:start position:0% +bound by a factor of square root of M +and in practice square root of M is + + align:start position:0% +and in practice square root of M is + + + align:start position:0% +and in practice square root of M is +actually not insignificant so for + + align:start position:0% +actually not insignificant so for + + + align:start position:0% +actually not insignificant so for +example if you're looking at the last + + align:start position:0% +example if you're looking at the last + + + align:start position:0% +example if you're looking at the last +level cache the size of that is on the + + align:start position:0% +level cache the size of that is on the + + + align:start position:0% +level cache the size of that is on the +order of megabytes so a square root of M + + align:start position:0% +order of megabytes so a square root of M + + + align:start position:0% +order of megabytes so a square root of M +is going to be on the order of thousands + + align:start position:0% +is going to be on the order of thousands + + + align:start position:0% +is going to be on the order of thousands +so this significantly improves the + + align:start position:0% +so this significantly improves the + + + align:start position:0% +so this significantly improves the +performance of the matrix multiplication + + align:start position:0% +performance of the matrix multiplication + + + align:start position:0% +performance of the matrix multiplication +code if you tune s so that the sub + + align:start position:0% +code if you tune s so that the sub + + + align:start position:0% +code if you tune s so that the sub +matrices just fit in the cache it turns + + align:start position:0% +matrices just fit in the cache it turns + + + align:start position:0% +matrices just fit in the cache it turns +out that this bound is off to most so + + align:start position:0% +out that this bound is off to most so + + + align:start position:0% +out that this bound is off to most so +this was shown in 1981 + + align:start position:0% +this was shown in 1981 + + + align:start position:0% +this was shown in 1981 +so for cubic work matrix multiplication + + align:start position:0% +so for cubic work matrix multiplication + + + align:start position:0% +so for cubic work matrix multiplication +this is the best you can do if you use + + align:start position:0% +this is the best you can do if you use + + + align:start position:0% +this is the best you can do if you use +another matrix multiply algorithm like + + align:start position:0% +another matrix multiply algorithm like + + + align:start position:0% +another matrix multiply algorithm like +strassens algorithm you can do better so + + align:start position:0% +strassens algorithm you can do better so + + + align:start position:0% +strassens algorithm you can do better so +I want you to remember this bound it's a + + align:start position:0% +I want you to remember this bound it's a + + + align:start position:0% +I want you to remember this bound it's a +very important bound to know says that + + align:start position:0% +very important bound to know says that + + + align:start position:0% +very important bound to know says that +for matrix multiplication you can you + + align:start position:0% +for matrix multiplication you can you + + + align:start position:0% +for matrix multiplication you can you +can benefit both from spatial locality + + align:start position:0% +can benefit both from spatial locality + + + align:start position:0% +can benefit both from spatial locality +as well as + + align:start position:0% +as well as + + + align:start position:0% +as well as +temporal locality so I get spatial + + align:start position:0% +temporal locality so I get spatial + + + align:start position:0% +temporal locality so I get spatial +locality in the denominator the B term + + align:start position:0% +locality in the denominator the B term + + + align:start position:0% +locality in the denominator the B term +in the denominator and then the square + + align:start position:0% +in the denominator and then the square + + + align:start position:0% +in the denominator and then the square +root of M term comes from temporal + + align:start position:0% +root of M term comes from temporal + + + align:start position:0% +root of M term comes from temporal +locality since I'm doing all of the work + + align:start position:0% +locality since I'm doing all of the work + + + align:start position:0% +locality since I'm doing all of the work +inside the sub-matrix before I evict + + align:start position:0% +inside the sub-matrix before I evict + + + align:start position:0% +inside the sub-matrix before I evict +that sub matrix from cache any questions + + align:start position:0% +that sub matrix from cache any questions + + + align:start position:0% +that sub matrix from cache any questions +on this analysis so what's one issue + + align:start position:0% +on this analysis so what's one issue + + + align:start position:0% +on this analysis so what's one issue +with this algorithm here yes yeah so the + + align:start position:0% +with this algorithm here yes yeah so the + + + align:start position:0% +with this algorithm here yes yeah so the +problem here is I have two two nests for + + align:start position:0% +problem here is I have two two nests for + + + align:start position:0% +problem here is I have two two nests for +my particular machine and I call this a + + align:start position:0% +my particular machine and I call this a + + + align:start position:0% +my particular machine and I call this a +voodoo parameter it's sort of like a + + align:start position:0% +voodoo parameter it's sort of like a + + + align:start position:0% +voodoo parameter it's sort of like a +magic number I I put into my program so + + align:start position:0% +magic number I I put into my program so + + + align:start position:0% +magic number I I put into my program so +that it fits in the cache on the + + align:start position:0% +that it fits in the cache on the + + + align:start position:0% +that it fits in the cache on the +particular machine I'm running on and + + align:start position:0% +particular machine I'm running on and + + + align:start position:0% +particular machine I'm running on and +this makes the code not portable because + + align:start position:0% +this makes the code not portable because + + + align:start position:0% +this makes the code not portable because +when I try if I try to run this code on + + align:start position:0% +when I try if I try to run this code on + + + align:start position:0% +when I try if I try to run this code on +another machine the cache sizes might be + + align:start position:0% +another machine the cache sizes might be + + + align:start position:0% +another machine the cache sizes might be +different there and then I won't get the + + align:start position:0% +different there and then I won't get the + + + align:start position:0% +different there and then I won't get the +same performance as I did on my machine + + align:start position:0% +same performance as I did on my machine + + + align:start position:0% +same performance as I did on my machine +and this is also an issue even if you're + + align:start position:0% +and this is also an issue even if you're + + + align:start position:0% +and this is also an issue even if you're +running it on the same machine because + + align:start position:0% +running it on the same machine because + + + align:start position:0% +running it on the same machine because +you might have other programs running at + + align:start position:0% +you might have other programs running at + + + align:start position:0% +you might have other programs running at +the same time and using a part of the + + align:start position:0% +the same time and using a part of the + + + align:start position:0% +the same time and using a part of the +cache so you don't actually know how + + align:start position:0% +cache so you don't actually know how + + + align:start position:0% +cache so you don't actually know how +much of the cache your program actually + + align:start position:0% +much of the cache your program actually + + + align:start position:0% +much of the cache your program actually +gets to use in a multi programming + + align:start position:0% +gets to use in a multi programming + + + align:start position:0% +gets to use in a multi programming +environment and then this was also just + + align:start position:0% +environment and then this was also just + + + align:start position:0% +environment and then this was also just +for one level of cache if we want to + + align:start position:0% +for one level of cache if we want to + + + align:start position:0% +for one level of cache if we want to +optimize for two levels of caches we're + + align:start position:0% +optimize for two levels of caches we're + + + align:start position:0% +optimize for two levels of caches we're +gonna have to voodoo parameters s and T + + align:start position:0% +gonna have to voodoo parameters s and T + + + align:start position:0% +gonna have to voodoo parameters s and T +we're gonna have sub matrices and sub + + align:start position:0% +we're gonna have sub matrices and sub + + + align:start position:0% +we're gonna have sub matrices and sub +sub matrices and then we have to tune + + align:start position:0% +sub matrices and then we have to tune + + + align:start position:0% +sub matrices and then we have to tune +both of these parameters to get the best + + align:start position:0% +both of these parameters to get the best + + + align:start position:0% +both of these parameters to get the best +performance on our machine and + + align:start position:0% +performance on our machine and + + + align:start position:0% +performance on our machine and +multi-dimensional tuning optimization + + align:start position:0% +multi-dimensional tuning optimization + + + align:start position:0% +multi-dimensional tuning optimization +can't be done simply with binary search + + align:start position:0% +can't be done simply with binary search + + + align:start position:0% +can't be done simply with binary search +so if you're just tuning for one level + + align:start position:0% +so if you're just tuning for one level + + + align:start position:0% +so if you're just tuning for one level +of cache you can do a binary search on + + align:start position:0% +of cache you can do a binary search on + + + align:start position:0% +of cache you can do a binary search on +the parameter s but here you can't do + + align:start position:0% +the parameter s but here you can't do + + + align:start position:0% +the parameter s but here you can't do +binary search so so it's much more + + align:start position:0% +binary search so so it's much more + + + align:start position:0% +binary search so so it's much more +expensive to optimize here and the code + + align:start position:0% +expensive to optimize here and the code + + + align:start position:0% +expensive to optimize here and the code +becomes a little bit Messier you have + + align:start position:0% +becomes a little bit Messier you have + + + align:start position:0% +becomes a little bit Messier you have +nine four loops instead of six and how + + align:start position:0% +nine four loops instead of six and how + + + align:start position:0% +nine four loops instead of six and how +many levels of caches do we have on the + + align:start position:0% +many levels of caches do we have on the + + + align:start position:0% +many levels of caches do we have on the +machines that we're using today three so + + align:start position:0% +machines that we're using today three so + + + align:start position:0% +machines that we're using today three so +four three level cache you have three + + align:start position:0% +four three level cache you have three + + + align:start position:0% +four three level cache you have three +voodoo + + align:start position:0% +voodoo + + + align:start position:0% +voodoo +parameters you have 12 nested for-loops + + align:start position:0% +parameters you have 12 nested for-loops + + + align:start position:0% +parameters you have 12 nested for-loops +this code becomes very ugly and you have + + align:start position:0% +this code becomes very ugly and you have + + + align:start position:0% +this code becomes very ugly and you have +to tune these parameters for your + + align:start position:0% +to tune these parameters for your + + + align:start position:0% +to tune these parameters for your +particular machine and this makes the + + align:start position:0% +particular machine and this makes the + + + align:start position:0% +particular machine and this makes the +code not very portable as one student + + align:start position:0% +code not very portable as one student + + + align:start position:0% +code not very portable as one student +pointed out and in a multi programmed + + align:start position:0% +pointed out and in a multi programmed + + + align:start position:0% +pointed out and in a multi programmed +environment you don't actually know the + + align:start position:0% +environment you don't actually know the + + + align:start position:0% +environment you don't actually know the +effective cache size that your program + + align:start position:0% +effective cache size that your program + + + align:start position:0% +effective cache size that your program +has access to because other jobs are + + align:start position:0% +has access to because other jobs are + + + align:start position:0% +has access to because other jobs are +running at the same time and therefore + + align:start position:0% +running at the same time and therefore + + + align:start position:0% +running at the same time and therefore +it's very easy to miss - in the + + align:start position:0% +it's very easy to miss - in the + + + align:start position:0% +it's very easy to miss - in the +parameters with their question so I need + + align:start position:0% +parameters with their question so I need + + + align:start position:0% +parameters with their question so I need +questions yeah yes so you I mean you can + + align:start position:0% +questions yeah yes so you I mean you can + + + align:start position:0% +questions yeah yes so you I mean you can +auto tune your program so that it's + + align:start position:0% +auto tune your program so that it's + + + align:start position:0% +auto tune your program so that it's +optimized for the cache sizes of your + + align:start position:0% +optimized for the cache sizes of your + + + align:start position:0% +optimized for the cache sizes of your +particular machine instruction to get + + align:start position:0% +particular machine instruction to get + + + align:start position:0% +particular machine instruction to get +the size of your cache I'm not actually + + align:start position:0% +the size of your cache I'm not actually + + + align:start position:0% +the size of your cache I'm not actually +sure do you know + + align:start position:0% + + + + align:start position:0% + +yeah in the rock + + align:start position:0% +yeah in the rock + + + align:start position:0% +yeah in the rock +[Music] + + align:start position:0% + + + + align:start position:0% + +yeah proxy pu info yeah yes so you can + + align:start position:0% +yeah proxy pu info yeah yes so you can + + + align:start position:0% +yeah proxy pu info yeah yes so you can +probably get that as well yeah yeah but + + align:start position:0% +probably get that as well yeah yeah but + + + align:start position:0% +probably get that as well yeah yeah but +even if you do that and you're running + + align:start position:0% +even if you do that and you're running + + + align:start position:0% +even if you do that and you're running +this program when other jobs are running + + align:start position:0% +this program when other jobs are running + + + align:start position:0% +this program when other jobs are running +you don't actually know how much cash + + align:start position:0% +you don't actually know how much cash + + + align:start position:0% +you don't actually know how much cash +your program has access to yes + + align:start position:0% + + + + align:start position:0% + +no it's they're actually general-purpose + + align:start position:0% +no it's they're actually general-purpose + + + align:start position:0% +no it's they're actually general-purpose +we're actually + + align:start position:0% +we're actually + + + align:start position:0% +we're actually +I mean today we're just looking at + + align:start position:0% +I mean today we're just looking at + + + align:start position:0% +I mean today we're just looking at +matrix multiply but in on Thursday's + + align:start position:0% +matrix multiply but in on Thursday's + + + align:start position:0% +matrix multiply but in on Thursday's +lecture we'll actually be looking at + + align:start position:0% +lecture we'll actually be looking at + + + align:start position:0% +lecture we'll actually be looking at +many other problems and how to optimize + + align:start position:0% +many other problems and how to optimize + + + align:start position:0% +many other problems and how to optimize +them for the cache hierarchy other + + align:start position:0% +them for the cache hierarchy other + + + align:start position:0% +them for the cache hierarchy other +questions + + align:start position:0% + + + + align:start position:0% + +okay so this was a I mean this was a + + align:start position:0% +okay so this was a I mean this was a + + + align:start position:0% +okay so this was a I mean this was a +good algorithm in terms of cache + + align:start position:0% +good algorithm in terms of cache + + + align:start position:0% +good algorithm in terms of cache +performance but it wasn't very portable + + align:start position:0% +performance but it wasn't very portable + + + align:start position:0% +performance but it wasn't very portable +so let's see if we can do better let's + + align:start position:0% +so let's see if we can do better let's + + + align:start position:0% +so let's see if we can do better let's +see we can come up with a simpler design + + align:start position:0% +see we can come up with a simpler design + + + align:start position:0% +see we can come up with a simpler design +where we still get pretty good cache + + align:start position:0% +where we still get pretty good cache + + + align:start position:0% +where we still get pretty good cache +performance so we're going to turn to + + align:start position:0% +performance so we're going to turn to + + + align:start position:0% +performance so we're going to turn to +dividing conquer we're going to look at + + align:start position:0% +dividing conquer we're going to look at + + + align:start position:0% +dividing conquer we're going to look at +the recursive matrix multiplication + + align:start position:0% +the recursive matrix multiplication + + + align:start position:0% +the recursive matrix multiplication +algorithm that we saw before again we're + + align:start position:0% +algorithm that we saw before again we're + + + align:start position:0% +algorithm that we saw before again we're +going to deal with square matrices but + + align:start position:0% +going to deal with square matrices but + + + align:start position:0% +going to deal with square matrices but +the results generalize to non square + + align:start position:0% +the results generalize to non square + + + align:start position:0% +the results generalize to non square +matrices so how this works is we're + + align:start position:0% +matrices so how this works is we're + + + align:start position:0% +matrices so how this works is we're +going to split our input matrices into + + align:start position:0% +going to split our input matrices into + + + align:start position:0% +going to split our input matrices into +four sub sub matrices or four quadrants + + align:start position:0% +four sub sub matrices or four quadrants + + + align:start position:0% +four sub sub matrices or four quadrants +and then for each quadrant of the output + + align:start position:0% +and then for each quadrant of the output + + + align:start position:0% +and then for each quadrant of the output +matrix it's just going to be the sum of + + align:start position:0% +matrix it's just going to be the sum of + + + align:start position:0% +matrix it's just going to be the sum of +two matrix multiplies on n over two by n + + align:start position:0% +two matrix multiplies on n over two by n + + + align:start position:0% +two matrix multiplies on n over two by n +over two matrices so c1 1 is going to be + + align:start position:0% +over two matrices so c1 1 is going to be + + + align:start position:0% +over two matrices so c1 1 is going to be +a1 1 times b1 1 plus a12 times b1 b2 1 + + align:start position:0% +a1 1 times b1 1 plus a12 times b1 b2 1 + + + align:start position:0% +a1 1 times b1 1 plus a12 times b1 b2 1 +and then we're gonna do this recursively + + align:start position:0% +and then we're gonna do this recursively + + + align:start position:0% +and then we're gonna do this recursively +so every level of recursion we're gonna + + align:start position:0% +so every level of recursion we're gonna + + + align:start position:0% +so every level of recursion we're gonna +get eight multiply adds of n over two by + + align:start position:0% +get eight multiply adds of n over two by + + + align:start position:0% +get eight multiply adds of n over two by +n over two matrices here's what the + + align:start position:0% +n over two matrices here's what the + + + align:start position:0% +n over two matrices here's what the +recursive code looks like you can see + + align:start position:0% +recursive code looks like you can see + + + align:start position:0% +recursive code looks like you can see +that we have eight recursive calls here + + align:start position:0% +that we have eight recursive calls here + + + align:start position:0% +that we have eight recursive calls here +the base case here is of size 1 in + + align:start position:0% +the base case here is of size 1 in + + + align:start position:0% +the base case here is of size 1 in +practice you want a course in the base + + align:start position:0% +practice you want a course in the base + + + align:start position:0% +practice you want a course in the base +case to overcome function call overheads + + align:start position:0% + + + + align:start position:0% + +let's also look at what these values + + align:start position:0% +let's also look at what these values + + + align:start position:0% +let's also look at what these values +here correspond to so I've color-coded + + align:start position:0% +here correspond to so I've color-coded + + + align:start position:0% +here correspond to so I've color-coded +these that they correspond to particular + + align:start position:0% +these that they correspond to particular + + + align:start position:0% +these that they correspond to particular +elements in the sub matrix that I'm + + align:start position:0% +elements in the sub matrix that I'm + + + align:start position:0% +elements in the sub matrix that I'm +looking at on the right so these values + + align:start position:0% +looking at on the right so these values + + + align:start position:0% +looking at on the right so these values +here corresponds to the index of the + + align:start position:0% +here corresponds to the index of the + + + align:start position:0% +here corresponds to the index of the +first element in each of my quadrants so + + align:start position:0% +first element in each of my quadrants so + + + align:start position:0% +first element in each of my quadrants so +the first element in my first quadrant + + align:start position:0% +the first element in my first quadrant + + + align:start position:0% +the first element in my first quadrant +is just gonna have an offset of zero and + + align:start position:0% +is just gonna have an offset of zero and + + + align:start position:0% +is just gonna have an offset of zero and +then the first element of my second + + align:start position:0% +then the first element of my second + + + align:start position:0% +then the first element of my second +quadrant that's gonna be on the same row + + align:start position:0% +quadrant that's gonna be on the same row + + + align:start position:0% +quadrant that's gonna be on the same row +as the first element in my first + + align:start position:0% +as the first element in my first + + + align:start position:0% +as the first element in my first +quadrant so I I just need to add a + + align:start position:0% +quadrant so I I just need to add a + + + align:start position:0% +quadrant so I I just need to add a +difference between the I just need to + + align:start position:0% +difference between the I just need to + + + align:start position:0% +difference between the I just need to +add the width of my quadrant which is n + + align:start position:0% +add the width of my quadrant which is n + + + align:start position:0% +add the width of my quadrant which is n +over 2 and then to get the first element + + align:start position:0% +over 2 and then to get the first element + + + align:start position:0% +over 2 and then to get the first element +in quadrant 2 1 I'm going to jump over + + align:start position:0% +in quadrant 2 1 I'm going to jump over + + + align:start position:0% +in quadrant 2 1 I'm going to jump over +and over to rows and + + align:start position:0% +and over to rows and + + + align:start position:0% +and over to rows and +each row has a length row size so it's + + align:start position:0% +each row has a length row size so it's + + + align:start position:0% +each row has a length row size so it's +just gonna be an over two times row size + + align:start position:0% +just gonna be an over two times row size + + + align:start position:0% +just gonna be an over two times row size +and then to get the first element in + + align:start position:0% +and then to get the first element in + + + align:start position:0% +and then to get the first element in +Quadrant 2 2 it's just the first element + + align:start position:0% +Quadrant 2 2 it's just the first element + + + align:start position:0% +Quadrant 2 2 it's just the first element +in Quadrant 2 1 + + / 2 so that's n over + + align:start position:0% +in Quadrant 2 1 + + / 2 so that's n over + + + align:start position:0% +in Quadrant 2 1 + + / 2 so that's n over +2 times row size plus 1 so let's analyze + + align:start position:0% +2 times row size plus 1 so let's analyze + + + align:start position:0% +2 times row size plus 1 so let's analyze +the work of this algorithm so what's the + + align:start position:0% +the work of this algorithm so what's the + + + align:start position:0% +the work of this algorithm so what's the +recurrence for this algorithm for the + + align:start position:0% +recurrence for this algorithm for the + + + align:start position:0% +recurrence for this algorithm for the +work of this algorithm so how many + + align:start position:0% +work of this algorithm so how many + + + align:start position:0% +work of this algorithm so how many +subproblems do we have 8 and what's the + + align:start position:0% +subproblems do we have 8 and what's the + + + align:start position:0% +subproblems do we have 8 and what's the +size of each subproblem n over 2 and how + + align:start position:0% +size of each subproblem n over 2 and how + + + align:start position:0% +size of each subproblem n over 2 and how +much work are we doing to set up the + + align:start position:0% +much work are we doing to set up the + + + align:start position:0% +much work are we doing to set up the +recursive calls constant amount of work + + align:start position:0% +recursive calls constant amount of work + + + align:start position:0% +recursive calls constant amount of work +so the recurrence is w of n is equal to + + align:start position:0% +so the recurrence is w of n is equal to + + + align:start position:0% +so the recurrence is w of n is equal to +8 w n over 2 plus theta of 1 and what + + align:start position:0% +8 w n over 2 plus theta of 1 and what + + + align:start position:0% +8 w n over 2 plus theta of 1 and what +does that solve to and cubed so it's one + + align:start position:0% +does that solve to and cubed so it's one + + + align:start position:0% +does that solve to and cubed so it's one +of the three cases of the master theorem + + align:start position:0% + + + + align:start position:0% + +we're actually going to analyze this in + + align:start position:0% +we're actually going to analyze this in + + + align:start position:0% +we're actually going to analyze this in +more detail using by drawing out the + + align:start position:0% +more detail using by drawing out the + + + align:start position:0% +more detail using by drawing out the +recursion tree and this is going to give + + align:start position:0% +recursion tree and this is going to give + + + align:start position:0% +recursion tree and this is going to give +us more intuition about why the master + + align:start position:0% +us more intuition about why the master + + + align:start position:0% +us more intuition about why the master +theorem is true so at the top level of + + align:start position:0% +theorem is true so at the top level of + + + align:start position:0% +theorem is true so at the top level of +my recursion tree I'm gonna have a + + align:start position:0% +my recursion tree I'm gonna have a + + + align:start position:0% +my recursion tree I'm gonna have a +problem of size N and then I'm gonna + + align:start position:0% +problem of size N and then I'm gonna + + + align:start position:0% +problem of size N and then I'm gonna +branch into 8 sub problems of size n + + align:start position:0% +branch into 8 sub problems of size n + + + align:start position:0% +branch into 8 sub problems of size n +over 2 and then I'm gonna do a constant + + align:start position:0% +over 2 and then I'm gonna do a constant + + + align:start position:0% +over 2 and then I'm gonna do a constant +amount of work to set up the recursive + + align:start position:0% +amount of work to set up the recursive + + + align:start position:0% +amount of work to set up the recursive +calls here I'm just labeling this with + + align:start position:0% +calls here I'm just labeling this with + + + align:start position:0% +calls here I'm just labeling this with +one so I'm ignoring the constants but + + align:start position:0% +one so I'm ignoring the constants but + + + align:start position:0% +one so I'm ignoring the constants but +it's not gonna matter for asymptotic + + align:start position:0% +it's not gonna matter for asymptotic + + + align:start position:0% +it's not gonna matter for asymptotic +analysis and then I'm gonna branch again + + align:start position:0% +analysis and then I'm gonna branch again + + + align:start position:0% +analysis and then I'm gonna branch again +into 8 sub problems of size and over + + align:start position:0% +into 8 sub problems of size and over + + + align:start position:0% +into 8 sub problems of size and over +four and eventually I'm gonna get down + + align:start position:0% +four and eventually I'm gonna get down + + + align:start position:0% +four and eventually I'm gonna get down +to the leaves and how many levels do I + + align:start position:0% +to the leaves and how many levels do I + + + align:start position:0% +to the leaves and how many levels do I +have until I get to the leaves + + align:start position:0% + + + + align:start position:0% + +yes yes o log n what's the base of the + + align:start position:0% +yes yes o log n what's the base of the + + + align:start position:0% +yes yes o log n what's the base of the +log + + align:start position:0% +log + + + align:start position:0% +log +yes it's log base 2 of n because I'm + + align:start position:0% +yes it's log base 2 of n because I'm + + + align:start position:0% +yes it's log base 2 of n because I'm +dividing my problem size by two every + + align:start position:0% +dividing my problem size by two every + + + align:start position:0% +dividing my problem size by two every +time and therefore the number of leaves + + align:start position:0% +time and therefore the number of leaves + + + align:start position:0% +time and therefore the number of leaves +I have is going to be 8 to the log base + + align:start position:0% +I have is going to be 8 to the log base + + + align:start position:0% +I have is going to be 8 to the log base +2 of n because I'm branching 8 ways + + align:start position:0% +2 of n because I'm branching 8 ways + + + align:start position:0% +2 of n because I'm branching 8 ways +every time 8 to the log base 2 of n is + + align:start position:0% +every time 8 to the log base 2 of n is + + + align:start position:0% +every time 8 to the log base 2 of n is +the same as n to the log base 2 of 8 + + align:start position:0% +the same as n to the log base 2 of 8 + + + align:start position:0% +the same as n to the log base 2 of 8 +which is n cubed the amount of work I'm + + align:start position:0% +which is n cubed the amount of work I'm + + + align:start position:0% +which is n cubed the amount of work I'm +doing at the top level is constant so + + align:start position:0% +doing at the top level is constant so + + + align:start position:0% +doing at the top level is constant so +I'm just gonna say one here the next log + + align:start position:0% +I'm just gonna say one here the next log + + + align:start position:0% +I'm just gonna say one here the next log +was eight times that then 64 and then + + align:start position:0% +was eight times that then 64 and then + + + align:start position:0% +was eight times that then 64 and then +when I get to the leaves it's going to + + align:start position:0% +when I get to the leaves it's going to + + + align:start position:0% +when I get to the leaves it's going to +be theta of n cubed since I have n cubed + + align:start position:0% +be theta of n cubed since I have n cubed + + + align:start position:0% +be theta of n cubed since I have n cubed +leaves and they're all doing constant + + align:start position:0% +leaves and they're all doing constant + + + align:start position:0% +leaves and they're all doing constant +work and the work is geometrically + + align:start position:0% +work and the work is geometrically + + + align:start position:0% +work and the work is geometrically +increasing as I go down the recursion + + align:start position:0% +increasing as I go down the recursion + + + align:start position:0% +increasing as I go down the recursion +tree so the overall work is just + + align:start position:0% +tree so the overall work is just + + + align:start position:0% +tree so the overall work is just +dominated by the work I need to do at + + align:start position:0% +dominated by the work I need to do at + + + align:start position:0% +dominated by the work I need to do at +the leaves so the overall work is just + + align:start position:0% +the leaves so the overall work is just + + + align:start position:0% +the leaves so the overall work is just +gonna be theta n cubed and this is the + + align:start position:0% +gonna be theta n cubed and this is the + + + align:start position:0% +gonna be theta n cubed and this is the +same as the looping versions of matrix + + align:start position:0% +same as the looping versions of matrix + + + align:start position:0% +same as the looping versions of matrix +multiply they're all cubic work now + + align:start position:0% +multiply they're all cubic work now + + + align:start position:0% +multiply they're all cubic work now +let's analyze the number of cache misses + + align:start position:0% +let's analyze the number of cache misses + + + align:start position:0% +let's analyze the number of cache misses +of this dividing conquer algorithm so + + align:start position:0% +of this dividing conquer algorithm so + + + align:start position:0% +of this dividing conquer algorithm so +now a migrant recurrence is gonna be + + align:start position:0% +now a migrant recurrence is gonna be + + + align:start position:0% +now a migrant recurrence is gonna be +different my base case now is when the + + align:start position:0% +different my base case now is when the + + + align:start position:0% +different my base case now is when the +sub matrix fits in the cache so when n + + align:start position:0% +sub matrix fits in the cache so when n + + + align:start position:0% +sub matrix fits in the cache so when n +squared is less than CM and when that's + + align:start position:0% +squared is less than CM and when that's + + + align:start position:0% +squared is less than CM and when that's +true I just need to load that some + + align:start position:0% +true I just need to load that some + + + align:start position:0% +true I just need to load that some +matrix in the cache and then I don't + + align:start position:0% +matrix in the cache and then I don't + + + align:start position:0% +matrix in the cache and then I don't +incur any more cache misses so I need + + align:start position:0% +incur any more cache misses so I need + + + align:start position:0% +incur any more cache misses so I need +theta of N squared over the cache misses + + align:start position:0% +theta of N squared over the cache misses + + + align:start position:0% +theta of N squared over the cache misses +when N squared is less than CM for some + + align:start position:0% +when N squared is less than CM for some + + + align:start position:0% +when N squared is less than CM for some +sophisticated sufficiently small + + align:start position:0% +sophisticated sufficiently small + + + align:start position:0% +sophisticated sufficiently small +constant C less than equal to 1 and then + + align:start position:0% +constant C less than equal to 1 and then + + + align:start position:0% +constant C less than equal to 1 and then +otherwise i recurse into 8 sub problems + + align:start position:0% +otherwise i recurse into 8 sub problems + + + align:start position:0% +otherwise i recurse into 8 sub problems +of size n over 2 and then I add theta of + + align:start position:0% +of size n over 2 and then I add theta of + + + align:start position:0% +of size n over 2 and then I add theta of +1 because I'm doing a constant amount of + + align:start position:0% +1 because I'm doing a constant amount of + + + align:start position:0% +1 because I'm doing a constant amount of +work to set up the recursive calls and I + + align:start position:0% +work to set up the recursive calls and I + + + align:start position:0% +work to set up the recursive calls and I +get this theta of N squared over B term + + align:start position:0% +get this theta of N squared over B term + + + align:start position:0% +get this theta of N squared over B term +from the sub matrix cashing lemma says I + + align:start position:0% +from the sub matrix cashing lemma says I + + + align:start position:0% +from the sub matrix cashing lemma says I +can just load the entire matrix into + + align:start position:0% +can just load the entire matrix into + + + align:start position:0% +can just load the entire matrix into +cache with this many cache misses so so + + align:start position:0% +cache with this many cache misses so so + + + align:start position:0% +cache with this many cache misses so so +the difference between the cache + + align:start position:0% +the difference between the cache + + + align:start position:0% +the difference between the cache +analysis here and the work analysis + + align:start position:0% +analysis here and the work analysis + + + align:start position:0% +analysis here and the work analysis +before is that I have a different base + + align:start position:0% +before is that I have a different base + + + align:start position:0% +before is that I have a different base +case and I think in all of that + + align:start position:0% +case and I think in all of that + + + align:start position:0% +case and I think in all of that +that you've seen before the base case + + align:start position:0% +that you've seen before the base case + + + align:start position:0% +that you've seen before the base case +was always of a constant size but here + + align:start position:0% +was always of a constant size but here + + + align:start position:0% +was always of a constant size but here +we're working with a base case that's + + align:start position:0% +we're working with a base case that's + + + align:start position:0% +we're working with a base case that's +not of a constant size so let's try to + + align:start position:0% +not of a constant size so let's try to + + + align:start position:0% +not of a constant size so let's try to +analyze this using the recursion tree + + align:start position:0% +analyze this using the recursion tree + + + align:start position:0% +analyze this using the recursion tree +approach so at the top level I have a + + align:start position:0% +approach so at the top level I have a + + + align:start position:0% +approach so at the top level I have a +problem of size n then I'm going to + + align:start position:0% +problem of size n then I'm going to + + + align:start position:0% +problem of size n then I'm going to +branch and do eight problems of size n + + align:start position:0% +branch and do eight problems of size n + + + align:start position:0% +branch and do eight problems of size n +over two and then I'm also going to + + align:start position:0% +over two and then I'm also going to + + + align:start position:0% +over two and then I'm also going to +incur constant number of cache misses + + align:start position:0% +incur constant number of cache misses + + + align:start position:0% +incur constant number of cache misses +I'm just gonna say one here then I'm + + align:start position:0% +I'm just gonna say one here then I'm + + + align:start position:0% +I'm just gonna say one here then I'm +gonna branch again and then eventually + + align:start position:0% +gonna branch again and then eventually + + + align:start position:0% +gonna branch again and then eventually +I'm going to get to the base case where + + align:start position:0% +I'm going to get to the base case where + + + align:start position:0% +I'm going to get to the base case where +N squared is less than CM and when N + + align:start position:0% +N squared is less than CM and when N + + + align:start position:0% +N squared is less than CM and when N +squared is less than CM then the number + + align:start position:0% +squared is less than CM then the number + + + align:start position:0% +squared is less than CM then the number +of cache misses that I'm gonna incur is + + align:start position:0% +of cache misses that I'm gonna incur is + + + align:start position:0% +of cache misses that I'm gonna incur is +going to be theta of CM over B so I can + + align:start position:0% +going to be theta of CM over B so I can + + + align:start position:0% +going to be theta of CM over B so I can +just plug in CM here for n squared and + + align:start position:0% +just plug in CM here for n squared and + + + align:start position:0% +just plug in CM here for n squared and +the number of levels of recursion I have + + align:start position:0% +the number of levels of recursion I have + + + align:start position:0% +the number of levels of recursion I have +in this recursion tree is no longer just + + align:start position:0% +in this recursion tree is no longer just + + + align:start position:0% +in this recursion tree is no longer just +log base two of n I'm gonna have log + + align:start position:0% +log base two of n I'm gonna have log + + + align:start position:0% +log base two of n I'm gonna have log +base two of n minus log base two of + + align:start position:0% +base two of n minus log base two of + + + align:start position:0% +base two of n minus log base two of +square root of CM number of levels which + + align:start position:0% +square root of CM number of levels which + + + align:start position:0% +square root of CM number of levels which +is the same as log base two of n minus + + align:start position:0% +is the same as log base two of n minus + + + align:start position:0% +is the same as log base two of n minus +1/2 times log base two of CM and then + + align:start position:0% +1/2 times log base two of CM and then + + + align:start position:0% +1/2 times log base two of CM and then +the number of leaves I get is going to + + align:start position:0% +the number of leaves I get is going to + + + align:start position:0% +the number of leaves I get is going to +be eight to this to this number of + + align:start position:0% +be eight to this to this number of + + + align:start position:0% +be eight to this to this number of +levels here says 8 to log base two of n + + align:start position:0% +levels here says 8 to log base two of n + + + align:start position:0% +levels here says 8 to log base two of n +minus 1/2 of log base two of cm and this + + align:start position:0% +minus 1/2 of log base two of cm and this + + + align:start position:0% +minus 1/2 of log base two of cm and this +is equal to theta of n cubed over m to + + align:start position:0% +is equal to theta of n cubed over m to + + + align:start position:0% +is equal to theta of n cubed over m to +the three halves so the n cubed comes + + align:start position:0% +the three halves so the n cubed comes + + + align:start position:0% +the three halves so the n cubed comes +from the eight to the log base two of n + + align:start position:0% +from the eight to the log base two of n + + + align:start position:0% +from the eight to the log base two of n +term and then if I do eight to the log + + align:start position:0% +term and then if I do eight to the log + + + align:start position:0% +term and then if I do eight to the log +base 8 to the negative one half of log + + align:start position:0% +base 8 to the negative one half of log + + + align:start position:0% +base 8 to the negative one half of log +base two of CM that's just gonna give me + + align:start position:0% +base two of CM that's just gonna give me + + + align:start position:0% +base two of CM that's just gonna give me +m over m to the three halves in the + + align:start position:0% +m over m to the three halves in the + + + align:start position:0% +m over m to the three halves in the +denominator so any questions on how I + + align:start position:0% +denominator so any questions on how I + + + align:start position:0% +denominator so any questions on how I +computed the number of levels of this + + align:start position:0% +computed the number of levels of this + + + align:start position:0% +computed the number of levels of this +recursion tree here + + align:start position:0% + + + + align:start position:0% + +so I'm basically dividing my problem + + align:start position:0% +so I'm basically dividing my problem + + + align:start position:0% +so I'm basically dividing my problem +size by two until I get to a problem + + align:start position:0% +size by two until I get to a problem + + + align:start position:0% +size by two until I get to a problem +size that fits into cash so that means n + + align:start position:0% +size that fits into cash so that means n + + + align:start position:0% +size that fits into cash so that means n +is less than square root of CM so + + align:start position:0% +is less than square root of CM so + + + align:start position:0% +is less than square root of CM so +therefore I can subtract that many + + align:start position:0% +therefore I can subtract that many + + + align:start position:0% +therefore I can subtract that many +levels for my recursion tree and then to + + align:start position:0% +levels for my recursion tree and then to + + + align:start position:0% +levels for my recursion tree and then to +get the number of leaves since I'm + + align:start position:0% +get the number of leaves since I'm + + + align:start position:0% +get the number of leaves since I'm +branching eight ways I just do eight to + + align:start position:0% +branching eight ways I just do eight to + + + align:start position:0% +branching eight ways I just do eight to +the power of the number of levels I have + + align:start position:0% +the power of the number of levels I have + + + align:start position:0% +the power of the number of levels I have +and then that gives me the total number + + align:start position:0% +and then that gives me the total number + + + align:start position:0% +and then that gives me the total number +of leaves + + align:start position:0% + + + + align:start position:0% + +so now let's analyze the number of cache + + align:start position:0% +so now let's analyze the number of cache + + + align:start position:0% +so now let's analyze the number of cache +misses I need at each level of this + + align:start position:0% +misses I need at each level of this + + + align:start position:0% +misses I need at each level of this +recursion tree at the top level I have a + + align:start position:0% +recursion tree at the top level I have a + + + align:start position:0% +recursion tree at the top level I have a +constant number of cache misses let's + + align:start position:0% +constant number of cache misses let's + + + align:start position:0% +constant number of cache misses let's +just say one the next level I have eight + + align:start position:0% +just say one the next level I have eight + + + align:start position:0% +just say one the next level I have eight +sixty-four and then at the leaves I'm + + align:start position:0% +sixty-four and then at the leaves I'm + + + align:start position:0% +sixty-four and then at the leaves I'm +going to have theta of n cubed over B + + align:start position:0% +going to have theta of n cubed over B + + + align:start position:0% +going to have theta of n cubed over B +times square root of M cache misses and + + align:start position:0% +times square root of M cache misses and + + + align:start position:0% +times square root of M cache misses and +I got this quantity just by multiplying + + align:start position:0% +I got this quantity just by multiplying + + + align:start position:0% +I got this quantity just by multiplying +the number of leaves by the number of + + align:start position:0% +the number of leaves by the number of + + + align:start position:0% +the number of leaves by the number of +cache misses per leaf so number of + + align:start position:0% +cache misses per leaf so number of + + + align:start position:0% +cache misses per leaf so number of +leaves is n cubed over m to the three + + align:start position:0% +leaves is n cubed over m to the three + + + align:start position:0% +leaves is n cubed over m to the three +halves the cache misses per leaves is + + align:start position:0% +halves the cache misses per leaves is + + + align:start position:0% +halves the cache misses per leaves is +state of CM over B so I lose one factor + + align:start position:0% +state of CM over B so I lose one factor + + + align:start position:0% +state of CM over B so I lose one factor +of B in the denominator I'm left with + + align:start position:0% +of B in the denominator I'm left with + + + align:start position:0% +of B in the denominator I'm left with +the square root of M at the bottom and + + align:start position:0% +the square root of M at the bottom and + + + align:start position:0% +the square root of M at the bottom and +then I also divide by the block size B + + align:start position:0% +then I also divide by the block size B + + + align:start position:0% +then I also divide by the block size B +so overall I get n cubed over B times + + align:start position:0% +so overall I get n cubed over B times + + + align:start position:0% +so overall I get n cubed over B times +square root of M cache misses and again + + align:start position:0% +square root of M cache misses and again + + + align:start position:0% +square root of M cache misses and again +this is a geometric series and the + + align:start position:0% +this is a geometric series and the + + + align:start position:0% +this is a geometric series and the +number of cache misses at the leaves + + align:start position:0% +number of cache misses at the leaves + + + align:start position:0% +number of cache misses at the leaves +dominates all of the other levels so the + + align:start position:0% +dominates all of the other levels so the + + + align:start position:0% +dominates all of the other levels so the +total number of cache misses I have is + + align:start position:0% +total number of cache misses I have is + + + align:start position:0% +total number of cache misses I have is +going to be theta n cubed over B times + + align:start position:0% +going to be theta n cubed over B times + + + align:start position:0% +going to be theta n cubed over B times +square root of M and notice that I'm + + align:start position:0% +square root of M and notice that I'm + + + align:start position:0% +square root of M and notice that I'm +getting the same number of cache misses + + align:start position:0% +getting the same number of cache misses + + + align:start position:0% +getting the same number of cache misses +as I did with the tiling version of the + + align:start position:0% +as I did with the tiling version of the + + + align:start position:0% +as I did with the tiling version of the +code but here I don't actually have the + + align:start position:0% +code but here I don't actually have the + + + align:start position:0% +code but here I don't actually have the +two in my code for the particular cache + + align:start position:0% +two in my code for the particular cache + + + align:start position:0% +two in my code for the particular cache +size so what cache sizes does this code + + align:start position:0% +size so what cache sizes does this code + + + align:start position:0% +size so what cache sizes does this code +work for + + align:start position:0% + + + + align:start position:0% + +so is this code gonna work on your + + align:start position:0% +so is this code gonna work on your + + + align:start position:0% +so is this code gonna work on your +machine it's gonna get good cache + + align:start position:0% +machine it's gonna get good cache + + + align:start position:0% +machine it's gonna get good cache +performance so this code is gonna work + + align:start position:0% +performance so this code is gonna work + + + align:start position:0% +performance so this code is gonna work +for all cache sizes because I didn't + + align:start position:0% +for all cache sizes because I didn't + + + align:start position:0% +for all cache sizes because I didn't +tune it for any particular cache size + + align:start position:0% +tune it for any particular cache size + + + align:start position:0% +tune it for any particular cache size +and this is what's known as a cache + + align:start position:0% +and this is what's known as a cache + + + align:start position:0% +and this is what's known as a cache +oblivious algorithm it doesn't have any + + align:start position:0% +oblivious algorithm it doesn't have any + + + align:start position:0% +oblivious algorithm it doesn't have any +Voodoo tuning parameters has no explicit + + align:start position:0% +Voodoo tuning parameters has no explicit + + + align:start position:0% +Voodoo tuning parameters has no explicit +knowledge of the caches and it's + + align:start position:0% +knowledge of the caches and it's + + + align:start position:0% +knowledge of the caches and it's +essentially passively Auto tuning itself + + align:start position:0% +essentially passively Auto tuning itself + + + align:start position:0% +essentially passively Auto tuning itself +for the particular cache size of your + + align:start position:0% +for the particular cache size of your + + + align:start position:0% +for the particular cache size of your +machine it can also work for multi-level + + align:start position:0% +machine it can also work for multi-level + + + align:start position:0% +machine it can also work for multi-level +caches automatically because I never + + align:start position:0% +caches automatically because I never + + + align:start position:0% +caches automatically because I never +specified what level of cache I'm + + align:start position:0% +specified what level of cache I'm + + + align:start position:0% +specified what level of cache I'm +analyzing this for I can analyze it for + + align:start position:0% +analyzing this for I can analyze it for + + + align:start position:0% +analyzing this for I can analyze it for +any level of cache and it's still gonna + + align:start position:0% +any level of cache and it's still gonna + + + align:start position:0% +any level of cache and it's still gonna +give me good cache complexity and this + + align:start position:0% +give me good cache complexity and this + + + align:start position:0% +give me good cache complexity and this +is also good in multi programmed + + align:start position:0% +is also good in multi programmed + + + align:start position:0% +is also good in multi programmed +environments where you might have other + + align:start position:0% +environments where you might have other + + + align:start position:0% +environments where you might have other +jobs running and you don't know your + + align:start position:0% +jobs running and you don't know your + + + align:start position:0% +jobs running and you don't know your +effective cache size this is just gonna + + align:start position:0% +effective cache size this is just gonna + + + align:start position:0% +effective cache size this is just gonna +pass all the auto-tune for whatever + + align:start position:0% +pass all the auto-tune for whatever + + + align:start position:0% +pass all the auto-tune for whatever +cache size is available turns out that + + align:start position:0% +cache size is available turns out that + + + align:start position:0% +cache size is available turns out that +the best cache oblivious codes today + + align:start position:0% +the best cache oblivious codes today + + + align:start position:0% +the best cache oblivious codes today +work on arbitrary rectangular matrices I + + align:start position:0% +work on arbitrary rectangular matrices I + + + align:start position:0% +work on arbitrary rectangular matrices I +just talked about square matrices but + + align:start position:0% +just talked about square matrices but + + + align:start position:0% +just talked about square matrices but +the best codes work on rectangular + + align:start position:0% +the best codes work on rectangular + + + align:start position:0% +the best codes work on rectangular +matrices and they perform binary + + align:start position:0% +matrices and they perform binary + + + align:start position:0% +matrices and they perform binary +splitting instead of eight-way splitting + + align:start position:0% +splitting instead of eight-way splitting + + + align:start position:0% +splitting instead of eight-way splitting +and you split on the largest of I J and + + align:start position:0% +and you split on the largest of I J and + + + align:start position:0% +and you split on the largest of I J and +K so this is what the best cache + + align:start position:0% +K so this is what the best cache + + + align:start position:0% +K so this is what the best cache +oblivious matrix multiplication + + align:start position:0% +oblivious matrix multiplication + + + align:start position:0% +oblivious matrix multiplication +algorithm does any questions + + align:start position:0% + + + + align:start position:0% + +okay so I only talked about the serial + + align:start position:0% +okay so I only talked about the serial + + + align:start position:0% +okay so I only talked about the serial +setting so far I was assuming that these + + align:start position:0% +setting so far I was assuming that these + + + align:start position:0% +setting so far I was assuming that these +algorithms ran on just a single thread + + align:start position:0% +algorithms ran on just a single thread + + + align:start position:0% +algorithms ran on just a single thread +what happens if I go to multiple + + align:start position:0% +what happens if I go to multiple + + + align:start position:0% +what happens if I go to multiple +processors turns out that the results do + + align:start position:0% +processors turns out that the results do + + + align:start position:0% +processors turns out that the results do +generalize to a parallel context so this + + align:start position:0% +generalize to a parallel context so this + + + align:start position:0% +generalize to a parallel context so this +is the recursive parallel + + align:start position:0% +is the recursive parallel + + + align:start position:0% +is the recursive parallel +matrix-multiply code that we saw before + + align:start position:0% +matrix-multiply code that we saw before + + + align:start position:0% +matrix-multiply code that we saw before +and notice that we're executing four sub + + align:start position:0% +and notice that we're executing four sub + + + align:start position:0% +and notice that we're executing four sub +calls in parallel doing a sync and then + + align:start position:0% +calls in parallel doing a sync and then + + + align:start position:0% +calls in parallel doing a sync and then +doing four more sub calls in parallel so + + align:start position:0% +doing four more sub calls in parallel so + + + align:start position:0% +doing four more sub calls in parallel so +let's try to analyze the number of cache + + align:start position:0% +let's try to analyze the number of cache + + + align:start position:0% +let's try to analyze the number of cache +misses in this parallel code and to do + + align:start position:0% +misses in this parallel code and to do + + + align:start position:0% +misses in this parallel code and to do +that we're gonna use this theorem which + + align:start position:0% +that we're gonna use this theorem which + + + align:start position:0% +that we're gonna use this theorem which +says that let Q sub P be the number of + + align:start position:0% +says that let Q sub P be the number of + + + align:start position:0% +says that let Q sub P be the number of +cache misses in a deterministic cell + + align:start position:0% +cache misses in a deterministic cell + + + align:start position:0% +cache misses in a deterministic cell +computation won't run on P processors + + align:start position:0% +computation won't run on P processors + + + align:start position:0% +computation won't run on P processors +each with a private cache of size M and + + align:start position:0% +each with a private cache of size M and + + + align:start position:0% +each with a private cache of size M and +let S sub P be the number of successful + + align:start position:0% +let S sub P be the number of successful + + + align:start position:0% +let S sub P be the number of successful +steals during the computation in the + + align:start position:0% +steals during the computation in the + + + align:start position:0% +steals during the computation in the +ideal cache model the number of cache + + align:start position:0% +ideal cache model the number of cache + + + align:start position:0% +ideal cache model the number of cache +misses we're gonna have is Q sub P equal + + align:start position:0% +misses we're gonna have is Q sub P equal + + + align:start position:0% +misses we're gonna have is Q sub P equal +to Q sub 1 plus Big O of number of + + align:start position:0% +to Q sub 1 plus Big O of number of + + + align:start position:0% +to Q sub 1 plus Big O of number of +steals times M over B so a number of + + align:start position:0% +steals times M over B so a number of + + + align:start position:0% +steals times M over B so a number of +cache misses in the parallel context is + + align:start position:0% +cache misses in the parallel context is + + + align:start position:0% +cache misses in the parallel context is +equal to a number of cache misses when + + align:start position:0% +equal to a number of cache misses when + + + align:start position:0% +equal to a number of cache misses when +you run it serially plus this term here + + align:start position:0% +you run it serially plus this term here + + + align:start position:0% +you run it serially plus this term here +which is the number of steals times M + + align:start position:0% +which is the number of steals times M + + + align:start position:0% +which is the number of steals times M +over B and a proof for this goes as fall + + align:start position:0% +over B and a proof for this goes as fall + + + align:start position:0% +over B and a proof for this goes as fall +so every call in the silk runtime system + + align:start position:0% +so every call in the silk runtime system + + + align:start position:0% +so every call in the silk runtime system +we can have workers steal tasks from + + align:start position:0% +we can have workers steal tasks from + + + align:start position:0% +we can have workers steal tasks from +other workers when they don't have work + + align:start position:0% +other workers when they don't have work + + + align:start position:0% +other workers when they don't have work +to do and after workers steals it has + + align:start position:0% +to do and after workers steals it has + + + align:start position:0% +to do and after workers steals it has +from another worker its cache becomes + + align:start position:0% +from another worker its cache becomes + + + align:start position:0% +from another worker its cache becomes +completely cold in the worst case + + align:start position:0% +completely cold in the worst case + + + align:start position:0% +completely cold in the worst case +because it wasn't actually working on + + align:start position:0% +because it wasn't actually working on + + + align:start position:0% +because it wasn't actually working on +that sub problem before but after M over + + align:start position:0% +that sub problem before but after M over + + + align:start position:0% +that sub problem before but after M over +B cold cache misses its cache is going + + align:start position:0% +B cold cache misses its cache is going + + + align:start position:0% +B cold cache misses its cache is going +to become identical to what it would be + + align:start position:0% +to become identical to what it would be + + + align:start position:0% +to become identical to what it would be +in the serial execution so we just need + + align:start position:0% +in the serial execution so we just need + + + align:start position:0% +in the serial execution so we just need +to pay em over B cache misses to make + + align:start position:0% +to pay em over B cache misses to make + + + align:start position:0% +to pay em over B cache misses to make +make it so that the cache looks the same + + align:start position:0% +make it so that the cache looks the same + + + align:start position:0% +make it so that the cache looks the same +as if they were executing serially and + + align:start position:0% +as if they were executing serially and + + + align:start position:0% +as if they were executing serially and +the same is true when a worker resumes a + + align:start position:0% +the same is true when a worker resumes a + + + align:start position:0% +the same is true when a worker resumes a +stolen computation after a silk sync and + + align:start position:0% +stolen computation after a silk sync and + + + align:start position:0% +stolen computation after a silk sync and +the number of times that these two + + align:start position:0% +the number of times that these two + + + align:start position:0% +the number of times that these two +situations can happen is two times SP + + align:start position:0% +situations can happen is two times SP + + + align:start position:0% +situations can happen is two times SP +two times the number of steals and each + + align:start position:0% +two times the number of steals and each + + + align:start position:0% +two times the number of steals and each +time we have to pay + + align:start position:0% +time we have to pay + + + align:start position:0% +time we have to pay +I'm over B cache misses and this is + + align:start position:0% +I'm over B cache misses and this is + + + align:start position:0% +I'm over B cache misses and this is +where this additive term comes from + + align:start position:0% +where this additive term comes from + + + align:start position:0% +where this additive term comes from +order S sub P times M over B we also + + align:start position:0% +order S sub P times M over B we also + + + align:start position:0% +order S sub P times M over B we also +know that the number of steals in a silk + + align:start position:0% +know that the number of steals in a silk + + + align:start position:0% +know that the number of steals in a silk +program is upper bounded by P times T + + align:start position:0% +program is upper bounded by P times T + + + align:start position:0% +program is upper bounded by P times T +infinity an expectation where P is a + + align:start position:0% +infinity an expectation where P is a + + + align:start position:0% +infinity an expectation where P is a +number of processors and T's infinity is + + align:start position:0% +number of processors and T's infinity is + + + align:start position:0% +number of processors and T's infinity is +the span of your computation so if you + + align:start position:0% +the span of your computation so if you + + + align:start position:0% +the span of your computation so if you +can minimize the span of your + + align:start position:0% +can minimize the span of your + + + align:start position:0% +can minimize the span of your +computation then this also gives you + + align:start position:0% +computation then this also gives you + + + align:start position:0% +computation then this also gives you +good cache bounds so moral of the story + + align:start position:0% +good cache bounds so moral of the story + + + align:start position:0% +good cache bounds so moral of the story +here is that minimizing the number of + + align:start position:0% +here is that minimizing the number of + + + align:start position:0% +here is that minimizing the number of +cache misses in the serial illusion + + align:start position:0% +cache misses in the serial illusion + + + align:start position:0% +cache misses in the serial illusion +essentially minimizes them in the + + align:start position:0% +essentially minimizes them in the + + + align:start position:0% +essentially minimizes them in the +parallel execution for a low span + + align:start position:0% +parallel execution for a low span + + + align:start position:0% +parallel execution for a low span +algorithm so in this recursive matrix + + align:start position:0% +algorithm so in this recursive matrix + + + align:start position:0% +algorithm so in this recursive matrix +multiplication algorithm the span of + + align:start position:0% +multiplication algorithm the span of + + + align:start position:0% +multiplication algorithm the span of +this is as follows so T infinity of n is + + align:start position:0% +this is as follows so T infinity of n is + + + align:start position:0% +this is as follows so T infinity of n is +2 T infinity of n over 2 plus theta of 1 + + align:start position:0% +2 T infinity of n over 2 plus theta of 1 + + + align:start position:0% +2 T infinity of n over 2 plus theta of 1 +since we're doing a sync here we have to + + align:start position:0% +since we're doing a sync here we have to + + + align:start position:0% +since we're doing a sync here we have to +pay the critical path length of two sub + + align:start position:0% +pay the critical path length of two sub + + + align:start position:0% +pay the critical path length of two sub +calls this solves two theta of N and + + align:start position:0% +calls this solves two theta of N and + + + align:start position:0% +calls this solves two theta of N and +applying the previous lemma this gives + + align:start position:0% +applying the previous lemma this gives + + + align:start position:0% +applying the previous lemma this gives +us a cache miss bound of theta of n + + align:start position:0% +us a cache miss bound of theta of n + + + align:start position:0% +us a cache miss bound of theta of n +cubed over B square root of M this is + + align:start position:0% +cubed over B square root of M this is + + + align:start position:0% +cubed over B square root of M this is +just the same as the serial execution + + align:start position:0% +just the same as the serial execution + + + align:start position:0% +just the same as the serial execution +and then this additive term is going to + + align:start position:0% +and then this additive term is going to + + + align:start position:0% +and then this additive term is going to +be order P times n and there's a span + + align:start position:0% +be order P times n and there's a span + + + align:start position:0% +be order P times n and there's a span +times M over B so that was a parallel + + align:start position:0% +times M over B so that was a parallel + + + align:start position:0% +times M over B so that was a parallel +that was a parallel algorithm for matrix + + align:start position:0% +that was a parallel algorithm for matrix + + + align:start position:0% +that was a parallel algorithm for matrix +multiply and we saw that we can also get + + align:start position:0% +multiply and we saw that we can also get + + + align:start position:0% +multiply and we saw that we can also get +good cache bounds there so here's a + + align:start position:0% +good cache bounds there so here's a + + + align:start position:0% +good cache bounds there so here's a +summary of what we talked about today we + + align:start position:0% +summary of what we talked about today we + + + align:start position:0% +summary of what we talked about today we +talked about Sousa tivity and caches + + align:start position:0% +talked about Sousa tivity and caches + + + align:start position:0% +talked about Sousa tivity and caches +different different ways you can design + + align:start position:0% +different different ways you can design + + + align:start position:0% +different different ways you can design +a cache talked about the ideal cache + + align:start position:0% +a cache talked about the ideal cache + + + align:start position:0% +a cache talked about the ideal cache +model that's useful for analyzing + + align:start position:0% +model that's useful for analyzing + + + align:start position:0% +model that's useful for analyzing +algorithms we talked about cache aware + + align:start position:0% +algorithms we talked about cache aware + + + align:start position:0% +algorithms we talked about cache aware +algorithm that have explicit knowledge + + align:start position:0% +algorithm that have explicit knowledge + + + align:start position:0% +algorithm that have explicit knowledge +of the cache and the example we use was + + align:start position:0% +of the cache and the example we use was + + + align:start position:0% +of the cache and the example we use was +tiled matrix multiply then we came up + + align:start position:0% +tiled matrix multiply then we came up + + + align:start position:0% +tiled matrix multiply then we came up +with a much simpler algorithm that was + + align:start position:0% +with a much simpler algorithm that was + + + align:start position:0% +with a much simpler algorithm that was +cache oblivious using dividing conquer + + align:start position:0% +cache oblivious using dividing conquer + + + align:start position:0% +cache oblivious using dividing conquer +and then on Thursdays lecture will + + align:start position:0% +and then on Thursdays lecture will + + + align:start position:0% +and then on Thursdays lecture will +actually see much more on cache + + align:start position:0% +actually see much more on cache + + + align:start position:0% +actually see much more on cache +oblivious algorithm designed and then + + align:start position:0% +oblivious algorithm designed and then + + + align:start position:0% +oblivious algorithm designed and then +you'll + + align:start position:0% +you'll + + + align:start position:0% +you'll +an opportunity to analyze the cash + + align:start position:0% +an opportunity to analyze the cash + + + align:start position:0% +an opportunity to analyze the cash +efficiency of some algorithms in the + + align:start position:0% +efficiency of some algorithms in the + + + align:start position:0% +efficiency of some algorithms in the +next homework \ No newline at end of file diff --git a/xDN5Onmu0mk.txt b/xDN5Onmu0mk.txt new file mode 100644 index 0000000000000000000000000000000000000000..ebb51ff09db91fc8a5aa3fce4c2ee33d536ba4d7 --- /dev/null +++ b/xDN5Onmu0mk.txt @@ -0,0 +1,1907 @@ +align:start position:0% + +we will now go through a beautiful + + align:start position:0% +we will now go through a beautiful + + + align:start position:0% +we will now go through a beautiful +example in which we approach the same + + align:start position:0% +example in which we approach the same + + + align:start position:0% +example in which we approach the same +question in a number of different ways + + align:start position:0% +question in a number of different ways + + + align:start position:0% +question in a number of different ways +and see that by reasoning based on the + + align:start position:0% +and see that by reasoning based on the + + + align:start position:0% +and see that by reasoning based on the +intuitive properties of a Poisson + + align:start position:0% +intuitive properties of a Poisson + + + align:start position:0% +intuitive properties of a Poisson +process we can arrive quickly to the + + align:start position:0% +process we can arrive quickly to the + + + align:start position:0% +process we can arrive quickly to the +right answer the problem is as follows + + align:start position:0% +right answer the problem is as follows + + + align:start position:0% +right answer the problem is as follows +we have three light bulbs and each light + + align:start position:0% +we have three light bulbs and each light + + + align:start position:0% +we have three light bulbs and each light +bulb is being lit at time 0 it starts + + align:start position:0% +bulb is being lit at time 0 it starts + + + align:start position:0% +bulb is being lit at time 0 it starts +working and the light bulb lasts for a + + align:start position:0% +working and the light bulb lasts for a + + + align:start position:0% +working and the light bulb lasts for a +certain amount of time which is random + + align:start position:0% +certain amount of time which is random + + + align:start position:0% +certain amount of time which is random +so this light bulb at last so long this + + align:start position:0% +so this light bulb at last so long this + + + align:start position:0% +so this light bulb at last so long this +one lasts so long this one lasts that + + align:start position:0% +one lasts so long this one lasts that + + + align:start position:0% +one lasts so long this one lasts that +long the lifetime of a light bulb the + + align:start position:0% +long the lifetime of a light bulb the + + + align:start position:0% +long the lifetime of a light bulb the +time until it burns out will be a random + + align:start position:0% +time until it burns out will be a random + + + align:start position:0% +time until it burns out will be a random +variable and we make the following + + align:start position:0% +variable and we make the following + + + align:start position:0% +variable and we make the following +assumptions the lifetimes of the three + + align:start position:0% +assumptions the lifetimes of the three + + + align:start position:0% +assumptions the lifetimes of the three +light bulbs which we denote by x y and z + + align:start position:0% +light bulbs which we denote by x y and z + + + align:start position:0% +light bulbs which we denote by x y and z +will be independent random variables + + align:start position:0% +will be independent random variables + + + align:start position:0% +will be independent random variables +each of which is an exponential random + + align:start position:0% +each of which is an exponential random + + + align:start position:0% +each of which is an exponential random +variable with the parameter lambda were + + align:start position:0% +variable with the parameter lambda were + + + align:start position:0% +variable with the parameter lambda were +interested in the question of + + align:start position:0% +interested in the question of + + + align:start position:0% +interested in the question of +calculating the expected time until a + + align:start position:0% +calculating the expected time until a + + + align:start position:0% +calculating the expected time until a +light bulb burns out for the first time + + align:start position:0% +light bulb burns out for the first time + + + align:start position:0% +light bulb burns out for the first time +so in this picture the light bulb that + + align:start position:0% +so in this picture the light bulb that + + + align:start position:0% +so in this picture the light bulb that +burned out first is this second light + + align:start position:0% +burned out first is this second light + + + align:start position:0% +burned out first is this second light +bulb and this quantity is the time until + + align:start position:0% +bulb and this quantity is the time until + + + align:start position:0% +bulb and this quantity is the time until +the first burn out how do we calculate + + align:start position:0% +the first burn out how do we calculate + + + align:start position:0% +the first burn out how do we calculate +this quantity the time until the first + + align:start position:0% +this quantity the time until the first + + + align:start position:0% +this quantity the time until the first +light bulb burns out is the minimum of + + align:start position:0% +light bulb burns out is the minimum of + + + align:start position:0% +light bulb burns out is the minimum of +the times at which each one of them + + align:start position:0% +the times at which each one of them + + + align:start position:0% +the times at which each one of them +burns out so we're interested in the + + align:start position:0% +burns out so we're interested in the + + + align:start position:0% +burns out so we're interested in the +expected value of this quantity it's a + + align:start position:0% +expected value of this quantity it's a + + + align:start position:0% +expected value of this quantity it's a +random variable which is a function of + + align:start position:0% +random variable which is a function of + + + align:start position:0% +random variable which is a function of +three random variables how do we + + align:start position:0% +three random variables how do we + + + align:start position:0% +three random variables how do we +calculate the expected value of a + + align:start position:0% +calculate the expected value of a + + + align:start position:0% +calculate the expected value of a +function of random variables we can use + + align:start position:0% +function of random variables we can use + + + align:start position:0% +function of random variables we can use +the expected value rule let us take the + + align:start position:0% +the expected value rule let us take the + + + align:start position:0% +the expected value rule let us take the +function of interest which is the + + align:start position:0% +function of interest which is the + + + align:start position:0% +function of interest which is the +minimum of three numbers then we need to + + align:start position:0% +minimum of three numbers then we need to + + + align:start position:0% +minimum of three numbers then we need to +multiply by the joint PDF of these three + + align:start position:0% +multiply by the joint PDF of these three + + + align:start position:0% +multiply by the joint PDF of these three +random variables XY and Z now because + + align:start position:0% +random variables XY and Z now because + + + align:start position:0% +random variables XY and Z now because +these three random variables are + + align:start position:0% +these three random variables are + + + align:start position:0% +these three random variables are +independent the joint PDF is the product + + align:start position:0% +independent the joint PDF is the product + + + align:start position:0% +independent the joint PDF is the product +of their individual PDFs which are all + + align:start position:0% +of their individual PDFs which are all + + + align:start position:0% +of their individual PDFs which are all +exponential and so we obtained this + + align:start position:0% +exponential and so we obtained this + + + align:start position:0% +exponential and so we obtained this +expression for the joint PDF and we need + + align:start position:0% +expression for the joint PDF and we need + + + align:start position:0% +expression for the joint PDF and we need +to integrate this over all x y&z + + align:start position:0% +to integrate this over all x y&z + + + align:start position:0% +to integrate this over all x y&z +so it's going to be an integral that + + align:start position:0% +so it's going to be an integral that + + + align:start position:0% +so it's going to be an integral that +goes for each one of the three variables + + align:start position:0% +goes for each one of the three variables + + + align:start position:0% +goes for each one of the three variables +from 0 to infinity and here we have DX + + align:start position:0% +from 0 to infinity and here we have DX + + + align:start position:0% +from 0 to infinity and here we have DX +dy DZ so this is one approach that can + + align:start position:0% +dy DZ so this is one approach that can + + + align:start position:0% +dy DZ so this is one approach that can +give us the answer if you're able to + + align:start position:0% +give us the answer if you're able to + + + align:start position:0% +give us the answer if you're able to +manipulate and keep track of everything + + align:start position:0% +manipulate and keep track of everything + + + align:start position:0% +manipulate and keep track of everything +that happens in this three-dimensional + + align:start position:0% +that happens in this three-dimensional + + + align:start position:0% +that happens in this three-dimensional +integral but this is too tedious and + + align:start position:0% +integral but this is too tedious and + + + align:start position:0% +integral but this is too tedious and +this is not a good way to go let us try + + align:start position:0% +this is not a good way to go let us try + + + align:start position:0% +this is not a good way to go let us try +to think of an alternative way can we + + align:start position:0% +to think of an alternative way can we + + + align:start position:0% +to think of an alternative way can we +figure out the distribution of this + + align:start position:0% +figure out the distribution of this + + + align:start position:0% +figure out the distribution of this +random variable it's a function of three + + align:start position:0% +random variable it's a function of three + + + align:start position:0% +random variable it's a function of three +random variables so in some sense it's a + + align:start position:0% +random variables so in some sense it's a + + + align:start position:0% +random variables so in some sense it's a +derived distribution problem so we can + + align:start position:0% +derived distribution problem so we can + + + align:start position:0% +derived distribution problem so we can +try to calculate the cumulative + + align:start position:0% +try to calculate the cumulative + + + align:start position:0% +try to calculate the cumulative +distribution function of the minimum of + + align:start position:0% +distribution function of the minimum of + + + align:start position:0% +distribution function of the minimum of +the three so for the cumulative we would + + align:start position:0% +the three so for the cumulative we would + + + align:start position:0% +the three so for the cumulative we would +be looking at the probability that the + + align:start position:0% +be looking at the probability that the + + + align:start position:0% +be looking at the probability that the +minimum of these three random variables + + align:start position:0% +minimum of these three random variables + + + align:start position:0% +minimum of these three random variables +is less than or equal to a certain + + align:start position:0% +is less than or equal to a certain + + + align:start position:0% +is less than or equal to a certain +number it turns out that the + + align:start position:0% +number it turns out that the + + + align:start position:0% +number it turns out that the +calculations are a little faster if we + + align:start position:0% +calculations are a little faster if we + + + align:start position:0% +calculations are a little faster if we +look at the probability that this is + + align:start position:0% +look at the probability that this is + + + align:start position:0% +look at the probability that this is +larger than or equal to a certain number + + align:start position:0% +larger than or equal to a certain number + + + align:start position:0% +larger than or equal to a certain number +what is this event the minimum is larger + + align:start position:0% +what is this event the minimum is larger + + + align:start position:0% +what is this event the minimum is larger +than or equal to T if and only if all + + align:start position:0% +than or equal to T if and only if all + + + align:start position:0% +than or equal to T if and only if all +three of them are larger than or equal + + align:start position:0% +three of them are larger than or equal + + + align:start position:0% +three of them are larger than or equal +to T so the probability of this event is + + align:start position:0% +to T so the probability of this event is + + + align:start position:0% +to T so the probability of this event is +the same as the probability that X is + + align:start position:0% +the same as the probability that X is + + + align:start position:0% +the same as the probability that X is +larger than or equal to T y larger than + + align:start position:0% +larger than or equal to T y larger than + + + align:start position:0% +larger than or equal to T y larger than +or equal to T and Z larger than or equal + + align:start position:0% +or equal to T and Z larger than or equal + + + align:start position:0% +or equal to T and Z larger than or equal +to T but now x y&z are independent so we + + align:start position:0% +to T but now x y&z are independent so we + + + align:start position:0% +to T but now x y&z are independent so we +need to multiply the probability that X + + align:start position:0% +need to multiply the probability that X + + + align:start position:0% +need to multiply the probability that X +is larger than or equal to T which for + + align:start position:0% +is larger than or equal to T which for + + + align:start position:0% +is larger than or equal to T which for +an exponential random variable is e to + + align:start position:0% +an exponential random variable is e to + + + align:start position:0% +an exponential random variable is e to +the minus lambda t then the probability + + align:start position:0% +the minus lambda t then the probability + + + align:start position:0% +the minus lambda t then the probability +of the second event which is again e to + + align:start position:0% +of the second event which is again e to + + + align:start position:0% +of the second event which is again e to +the minus lambda T and finally the + + align:start position:0% +the minus lambda T and finally the + + + align:start position:0% +the minus lambda T and finally the +probability of the third event which is + + align:start position:0% +probability of the third event which is + + + align:start position:0% +probability of the third event which is +again e to the minus lambda T which is e + + align:start position:0% +again e to the minus lambda T which is e + + + align:start position:0% +again e to the minus lambda T which is e +to the minus 3 lambda T now we look at + + align:start position:0% +to the minus 3 lambda T now we look at + + + align:start position:0% +to the minus 3 lambda T now we look at +this expression for the probability that + + align:start position:0% +this expression for the probability that + + + align:start position:0% +this expression for the probability that +the random variable is larger than or + + align:start position:0% +the random variable is larger than or + + + align:start position:0% +the random variable is larger than or +equal to T and recognize that this is + + align:start position:0% +equal to T and recognize that this is + + + align:start position:0% +equal to T and recognize that this is +the expression that we have when we have + + align:start position:0% +the expression that we have when we have + + + align:start position:0% +the expression that we have when we have +an exponential random variable with + + align:start position:0% +an exponential random variable with + + + align:start position:0% +an exponential random variable with +parameter equal + + align:start position:0% +parameter equal + + + align:start position:0% +parameter equal +two three lambda if you want to do it + + align:start position:0% +two three lambda if you want to do it + + + align:start position:0% +two three lambda if you want to do it +formally subtract this quantity from one + + align:start position:0% +formally subtract this quantity from one + + + align:start position:0% +formally subtract this quantity from one +to find the CDF take the derivative and + + align:start position:0% +to find the CDF take the derivative and + + + align:start position:0% +to find the CDF take the derivative and +you will find an exponential PDF so the + + align:start position:0% +you will find an exponential PDF so the + + + align:start position:0% +you will find an exponential PDF so the +conclusion is that this random variable + + align:start position:0% +conclusion is that this random variable + + + align:start position:0% +conclusion is that this random variable +is exponential with parameter three + + align:start position:0% +is exponential with parameter three + + + align:start position:0% +is exponential with parameter three +lambda and since it's an exponential + + align:start position:0% +lambda and since it's an exponential + + + align:start position:0% +lambda and since it's an exponential +with parameter three lambda then we know + + align:start position:0% +with parameter three lambda then we know + + + align:start position:0% +with parameter three lambda then we know +what the expected value is it is going + + align:start position:0% +what the expected value is it is going + + + align:start position:0% +what the expected value is it is going +to be one over three lambda and this is + + align:start position:0% +to be one over three lambda and this is + + + align:start position:0% +to be one over three lambda and this is +the answer to the question that you were + + align:start position:0% +the answer to the question that you were + + + align:start position:0% +the answer to the question that you were +interested in now the fact that this is + + align:start position:0% +interested in now the fact that this is + + + align:start position:0% +interested in now the fact that this is +an exponential random variable but with + + align:start position:0% +an exponential random variable but with + + + align:start position:0% +an exponential random variable but with +a different parameter is a pretty clean + + align:start position:0% +a different parameter is a pretty clean + + + align:start position:0% +a different parameter is a pretty clean +fact and so it should have a good + + align:start position:0% +fact and so it should have a good + + + align:start position:0% +fact and so it should have a good +explanation let us now try to think + + align:start position:0% +explanation let us now try to think + + + align:start position:0% +explanation let us now try to think +about a good explanation for this fact + + align:start position:0% +about a good explanation for this fact + + + align:start position:0% +about a good explanation for this fact +whenever we deal with an exponential + + align:start position:0% +whenever we deal with an exponential + + + align:start position:0% +whenever we deal with an exponential +random variable one way of thinking + + align:start position:0% +random variable one way of thinking + + + align:start position:0% +random variable one way of thinking +about it is that this exponential random + + align:start position:0% +about it is that this exponential random + + + align:start position:0% +about it is that this exponential random +variable is the first time in a Poisson + + align:start position:0% +variable is the first time in a Poisson + + + align:start position:0% +variable is the first time in a Poisson +process so imagine that there is a + + align:start position:0% +process so imagine that there is a + + + align:start position:0% +process so imagine that there is a +Poisson process that runs forever and X + + align:start position:0% +Poisson process that runs forever and X + + + align:start position:0% +Poisson process that runs forever and X +is the first arrival time for this light + + align:start position:0% +is the first arrival time for this light + + + align:start position:0% +is the first arrival time for this light +bulb we can think the same way and since + + align:start position:0% +bulb we can think the same way and since + + + align:start position:0% +bulb we can think the same way and since +x and y are assumed to be independent we + + align:start position:0% +x and y are assumed to be independent we + + + align:start position:0% +x and y are assumed to be independent we +can assume that here we have an + + align:start position:0% +can assume that here we have an + + + align:start position:0% +can assume that here we have an +independent Poisson process independent + + align:start position:0% +independent Poisson process independent + + + align:start position:0% +independent Poisson process independent +from the first one it has its own + + align:start position:0% +from the first one it has its own + + + align:start position:0% +from the first one it has its own +arrival times and Y is the first arrival + + align:start position:0% +arrival times and Y is the first arrival + + + align:start position:0% +arrival times and Y is the first arrival +time in this Poisson process and finally + + align:start position:0% +time in this Poisson process and finally + + + align:start position:0% +time in this Poisson process and finally +we have a third independent Poisson + + align:start position:0% +we have a third independent Poisson + + + align:start position:0% +we have a third independent Poisson +process and the random variable Z is the + + align:start position:0% +process and the random variable Z is the + + + align:start position:0% +process and the random variable Z is the +first arrival time in that Poisson + + align:start position:0% +first arrival time in that Poisson + + + align:start position:0% +first arrival time in that Poisson +process so XY and z are interpreted as + + align:start position:0% +process so XY and z are interpreted as + + + align:start position:0% +process so XY and z are interpreted as +first arrivals in three independent + + align:start position:0% +first arrivals in three independent + + + align:start position:0% +first arrivals in three independent +Poisson processes now let us take these + + align:start position:0% +Poisson processes now let us take these + + + align:start position:0% +Poisson processes now let us take these +three Poisson processes and merge them + + align:start position:0% +three Poisson processes and merge them + + + align:start position:0% +three Poisson processes and merge them +if we merge these three processes + + align:start position:0% +if we merge these three processes + + + align:start position:0% +if we merge these three processes +what we obtain is a merged process which + + align:start position:0% +what we obtain is a merged process which + + + align:start position:0% +what we obtain is a merged process which +is Poisson with parameter equal to the + + align:start position:0% +is Poisson with parameter equal to the + + + align:start position:0% +is Poisson with parameter equal to the +sum of the rates or parameters of each + + align:start position:0% +sum of the rates or parameters of each + + + align:start position:0% +sum of the rates or parameters of each +one of the processes so it's a Poisson + + align:start position:0% +one of the processes so it's a Poisson + + + align:start position:0% +one of the processes so it's a Poisson +process with parameter 3 lambda now how + + align:start position:0% +process with parameter 3 lambda now how + + + align:start position:0% +process with parameter 3 lambda now how +can we interpret the random variable of + + align:start position:0% +can we interpret the random variable of + + + align:start position:0% +can we interpret the random variable of +interest the first Burnout + + align:start position:0% +interest the first Burnout + + + align:start position:0% +interest the first Burnout +in terms of the merged process so the + + align:start position:0% +in terms of the merged process so the + + + align:start position:0% +in terms of the merged process so the +merged process has an arrival whenever + + align:start position:0% +merged process has an arrival whenever + + + align:start position:0% +merged process has an arrival whenever +one of those three processes has an + + align:start position:0% +one of those three processes has an + + + align:start position:0% +one of those three processes has an +arrival the first arrival in the merged + + align:start position:0% +arrival the first arrival in the merged + + + align:start position:0% +arrival the first arrival in the merged +process will happen the first time that + + align:start position:0% +process will happen the first time that + + + align:start position:0% +process will happen the first time that +one of these three processes is going to + + align:start position:0% +one of these three processes is going to + + + align:start position:0% +one of these three processes is going to +have an arrival therefore we can + + align:start position:0% +have an arrival therefore we can + + + align:start position:0% +have an arrival therefore we can +interpret the random variable of + + align:start position:0% +interpret the random variable of + + + align:start position:0% +interpret the random variable of +interest the first burnout time as the + + align:start position:0% +interest the first burnout time as the + + + align:start position:0% +interest the first burnout time as the +first arrival time in a merged process + + align:start position:0% +first arrival time in a merged process + + + align:start position:0% +first arrival time in a merged process +but now the merged process is Poisson + + align:start position:0% +but now the merged process is Poisson + + + align:start position:0% +but now the merged process is Poisson +with parameter three lambda therefore + + align:start position:0% +with parameter three lambda therefore + + + align:start position:0% +with parameter three lambda therefore +this random variable is going to be an + + align:start position:0% +this random variable is going to be an + + + align:start position:0% +this random variable is going to be an +exponential random variable with + + align:start position:0% +exponential random variable with + + + align:start position:0% +exponential random variable with +parameter three lambda and from this we + + align:start position:0% +parameter three lambda and from this we + + + align:start position:0% +parameter three lambda and from this we +also obtain the expected value of that + + align:start position:0% +also obtain the expected value of that + + + align:start position:0% +also obtain the expected value of that +random variable the beauty of this last + + align:start position:0% +random variable the beauty of this last + + + align:start position:0% +random variable the beauty of this last +approach for coming up with the answer + + align:start position:0% +approach for coming up with the answer + + + align:start position:0% +approach for coming up with the answer +by reasoning in terms of merged Poisson + + align:start position:0% +by reasoning in terms of merged Poisson + + + align:start position:0% +by reasoning in terms of merged Poisson +processes is that we didn't have to do + + align:start position:0% +processes is that we didn't have to do + + + align:start position:0% +processes is that we didn't have to do +any calculations at all just use the + + align:start position:0% +any calculations at all just use the + + + align:start position:0% +any calculations at all just use the +intuitive understanding of Poisson + + align:start position:0% +intuitive understanding of Poisson + + + align:start position:0% +intuitive understanding of Poisson +processes and especially the + + align:start position:0% +processes and especially the + + + align:start position:0% +processes and especially the +interpretation of an exponential random + + align:start position:0% +interpretation of an exponential random + + + align:start position:0% +interpretation of an exponential random +variable as the first arrival time in a + + align:start position:0% +variable as the first arrival time in a + + + align:start position:0% +variable as the first arrival time in a +Poisson process let us now try to solve + + align:start position:0% +Poisson process let us now try to solve + + + align:start position:0% +Poisson process let us now try to solve +a somewhat harder problem let us try to + + align:start position:0% +a somewhat harder problem let us try to + + + align:start position:0% +a somewhat harder problem let us try to +calculate the expected time until all + + align:start position:0% +calculate the expected time until all + + + align:start position:0% +calculate the expected time until all +light bulbs burn out so one light bulb + + align:start position:0% +light bulbs burn out so one light bulb + + + align:start position:0% +light bulbs burn out so one light bulb +will burn out then another one will burn + + align:start position:0% +will burn out then another one will burn + + + align:start position:0% +will burn out then another one will burn +out and finally the third one will burn + + align:start position:0% +out and finally the third one will burn + + + align:start position:0% +out and finally the third one will burn +out we want to find the expected time + + align:start position:0% +out we want to find the expected time + + + align:start position:0% +out we want to find the expected time +until this happens once more we will be + + align:start position:0% +until this happens once more we will be + + + align:start position:0% +until this happens once more we will be +thinking of these burn out times as the + + align:start position:0% +thinking of these burn out times as the + + + align:start position:0% +thinking of these burn out times as the +first arrival times in Poisson processes + + align:start position:0% +first arrival times in Poisson processes + + + align:start position:0% +first arrival times in Poisson processes +the total time until the third burnout + + align:start position:0% +the total time until the third burnout + + + align:start position:0% +the total time until the third burnout +can be split into different periods + + align:start position:0% +can be split into different periods + + + align:start position:0% +can be split into different periods +there is a time until one light bulb + + align:start position:0% +there is a time until one light bulb + + + align:start position:0% +there is a time until one light bulb +burns out and the expected value of this + + align:start position:0% +burns out and the expected value of this + + + align:start position:0% +burns out and the expected value of this +period here is going to be one over + + align:start position:0% +period here is going to be one over + + + align:start position:0% +period here is going to be one over +three lambda what happens at this time + + align:start position:0% +three lambda what happens at this time + + + align:start position:0% +three lambda what happens at this time +the second light bulb has burned out so + + align:start position:0% +the second light bulb has burned out so + + + align:start position:0% +the second light bulb has burned out so +we can forget about it take it out of + + align:start position:0% +we can forget about it take it out of + + + align:start position:0% +we can forget about it take it out of +the picture + + align:start position:0% +the picture + + + align:start position:0% +the picture +we have two light bulbs let us look at + + align:start position:0% +we have two light bulbs let us look at + + + align:start position:0% +we have two light bulbs let us look at +the time it will take until one of these + + align:start position:0% +the time it will take until one of these + + + align:start position:0% +the time it will take until one of these +two light bulbs burns out so we're + + align:start position:0% +two light bulbs burns out so we're + + + align:start position:0% +two light bulbs burns out so we're +interested in this period of time + + align:start position:0% +interested in this period of time + + + align:start position:0% +interested in this period of time +now the Poisson process starts fresh at + + align:start position:0% +now the Poisson process starts fresh at + + + align:start position:0% +now the Poisson process starts fresh at +this time after this time whatever + + align:start position:0% +this time after this time whatever + + + align:start position:0% +this time after this time whatever +happens is just an ordinary Poisson + + align:start position:0% +happens is just an ordinary Poisson + + + align:start position:0% +happens is just an ordinary Poisson +process as if it was starting at this + + align:start position:0% +process as if it was starting at this + + + align:start position:0% +process as if it was starting at this +time so this is going to be an + + align:start position:0% +time so this is going to be an + + + align:start position:0% +time so this is going to be an +exponential random variable starting + + align:start position:0% +exponential random variable starting + + + align:start position:0% +exponential random variable starting +from this time and this is going to be + + align:start position:0% +from this time and this is going to be + + + align:start position:0% +from this time and this is going to be +another exponential random variable so + + align:start position:0% +another exponential random variable so + + + align:start position:0% +another exponential random variable so +the time until the next light bulb burns + + align:start position:0% +the time until the next light bulb burns + + + align:start position:0% +the time until the next light bulb burns +out in this case is going to be the + + align:start position:0% +out in this case is going to be the + + + align:start position:0% +out in this case is going to be the +minimum of two exponential random + + align:start position:0% +minimum of two exponential random + + + align:start position:0% +minimum of two exponential random +variables we can think again about + + align:start position:0% +variables we can think again about + + + align:start position:0% +variables we can think again about +merging these two Poisson processes to + + align:start position:0% +merging these two Poisson processes to + + + align:start position:0% +merging these two Poisson processes to +obtain a Poisson process with total rate + + align:start position:0% +obtain a Poisson process with total rate + + + align:start position:0% +obtain a Poisson process with total rate +two lambda and the time until one of + + align:start position:0% +two lambda and the time until one of + + + align:start position:0% +two lambda and the time until one of +these two burns out is going to be the + + align:start position:0% +these two burns out is going to be the + + + align:start position:0% +these two burns out is going to be the +first arrival time in that merged + + align:start position:0% +first arrival time in that merged + + + align:start position:0% +first arrival time in that merged +process and so the expected time until + + align:start position:0% +process and so the expected time until + + + align:start position:0% +process and so the expected time until +the first arrival of the merged process + + align:start position:0% +the first arrival of the merged process + + + align:start position:0% +the first arrival of the merged process +is going to be one over two lambda and + + align:start position:0% +is going to be one over two lambda and + + + align:start position:0% +is going to be one over two lambda and +finally once this burned out has + + align:start position:0% +finally once this burned out has + + + align:start position:0% +finally once this burned out has +happened we can forget about this light + + align:start position:0% +happened we can forget about this light + + + align:start position:0% +happened we can forget about this light +bulb we're left just with one light bulb + + align:start position:0% +bulb we're left just with one light bulb + + + align:start position:0% +bulb we're left just with one light bulb +and starting from here we wait until + + align:start position:0% +and starting from here we wait until + + + align:start position:0% +and starting from here we wait until +that light bulb burns out once more + + align:start position:0% +that light bulb burns out once more + + + align:start position:0% +that light bulb burns out once more +because of the fresh start property of + + align:start position:0% +because of the fresh start property of + + + align:start position:0% +because of the fresh start property of +the Poisson process starting from here + + align:start position:0% +the Poisson process starting from here + + + align:start position:0% +the Poisson process starting from here +until it burns out is going to be a + + align:start position:0% +until it burns out is going to be a + + + align:start position:0% +until it burns out is going to be a +random variable which is an exponential + + align:start position:0% +random variable which is an exponential + + + align:start position:0% +random variable which is an exponential +random variable and in this case an + + align:start position:0% +random variable and in this case an + + + align:start position:0% +random variable and in this case an +exponential random variable with rate + + align:start position:0% +exponential random variable with rate + + + align:start position:0% +exponential random variable with rate +just lambda and by adding these three + + align:start position:0% +just lambda and by adding these three + + + align:start position:0% +just lambda and by adding these three +quantities we get the expected time + + align:start position:0% +quantities we get the expected time + + + align:start position:0% +quantities we get the expected time +until all three have burned out this is + + align:start position:0% +until all three have burned out this is + + + align:start position:0% +until all three have burned out this is +a problem that would have been quite + + align:start position:0% +a problem that would have been quite + + + align:start position:0% +a problem that would have been quite +hard to solve in a more analytical way + + align:start position:0% +hard to solve in a more analytical way + + + align:start position:0% +hard to solve in a more analytical way +we're dealing with a random variable + + align:start position:0% +we're dealing with a random variable + + + align:start position:0% +we're dealing with a random variable +which is now the maximum of XY and Z and + + align:start position:0% +which is now the maximum of XY and Z and + + + align:start position:0% +which is now the maximum of XY and Z and +the distribution of this random variable + + align:start position:0% +the distribution of this random variable + + + align:start position:0% +the distribution of this random variable +is not so simple to write down so it + + align:start position:0% +is not so simple to write down so it + + + align:start position:0% +is not so simple to write down so it +that would not be a very good approach + + align:start position:0% +that would not be a very good approach + + + align:start position:0% +that would not be a very good approach +for going about this problem but we + + align:start position:0% +for going about this problem but we + + + align:start position:0% +for going about this problem but we +managed to find the expected value + + align:start position:0% +managed to find the expected value + + + align:start position:0% +managed to find the expected value +this random variable without having to + + align:start position:0% +this random variable without having to + + + align:start position:0% +this random variable without having to +write down its distribution by breaking + + align:start position:0% +write down its distribution by breaking + + + align:start position:0% +write down its distribution by breaking +this random variable into a sum of three + + align:start position:0% +this random variable into a sum of three + + + align:start position:0% +this random variable into a sum of three +particular random variables each of + + align:start position:0% +particular random variables each of + + + align:start position:0% +particular random variables each of +which had a nice intuitive + + align:start position:0% +which had a nice intuitive + + + align:start position:0% +which had a nice intuitive +interpretation and that was the key to + + align:start position:0% +interpretation and that was the key to + + + align:start position:0% +interpretation and that was the key to +the solution of this problem \ No newline at end of file diff --git a/xVka6z1hu-I.txt b/xVka6z1hu-I.txt new file mode 100644 index 0000000000000000000000000000000000000000..065245a9bd81cf8cd6b03f6f9a80f68610189bc5 --- /dev/null +++ b/xVka6z1hu-I.txt @@ -0,0 +1,13739 @@ +align:start position:0% + +The following content is provided under + + align:start position:0% +The following content is provided under + + + align:start position:0% +The following content is provided under +a Creative Common License. Your support + + align:start position:0% +a Creative Common License. Your support + + + align:start position:0% +a Creative Common License. Your support +will help MIT Open Courseware continue + + align:start position:0% +will help MIT Open Courseware continue + + + align:start position:0% +will help MIT Open Courseware continue +to offer high-quality educational + + align:start position:0% +to offer high-quality educational + + + align:start position:0% +to offer high-quality educational +resources for free. To make a donation + + align:start position:0% +resources for free. To make a donation + + + align:start position:0% +resources for free. To make a donation +or view additional materials from + + align:start position:0% +or view additional materials from + + + align:start position:0% +or view additional materials from +hundreds of MIT courses, visit MIT Open + + align:start position:0% +hundreds of MIT courses, visit MIT Open + + + align:start position:0% +hundreds of MIT courses, visit MIT Open +Courseware at ocw.mmit.edu. + + align:start position:0% + + + + align:start position:0% + +All right, let's get started. + + align:start position:0% +All right, let's get started. + + + align:start position:0% +All right, let's get started. +Today we have another data structures + + align:start position:0% +Today we have another data structures + + + align:start position:0% +Today we have another data structures +topic which is data structure + + align:start position:0% +topic which is data structure + + + align:start position:0% +topic which is data structure +augmentation. + + align:start position:0% +augmentation. + + + align:start position:0% +augmentation. +Uh the idea here is we're going to take + + align:start position:0% +Uh the idea here is we're going to take + + + align:start position:0% +Uh the idea here is we're going to take +some existing data structure and augment + + align:start position:0% +some existing data structure and augment + + + align:start position:0% +some existing data structure and augment +it to do extra cool things. So + + align:start position:0% + + + + align:start position:0% + +take some other data structure that + + align:start position:0% +take some other data structure that + + + align:start position:0% +take some other data structure that +we've covered. Uh typically that'll be a + + align:start position:0% +we've covered. Uh typically that'll be a + + + align:start position:0% +we've covered. Uh typically that'll be a +balanced search tree like an AVL tree or + + align:start position:0% +balanced search tree like an AVL tree or + + + align:start position:0% +balanced search tree like an AVL tree or +a 23 tree. + + align:start position:0% + + + + align:start position:0% + +And then we'll modify it to store extra + + align:start position:0% +And then we'll modify it to store extra + + + align:start position:0% +And then we'll modify it to store extra +information which will enable additional + + align:start position:0% +information which will enable additional + + + align:start position:0% +information which will enable additional +kinds of searches typically + + align:start position:0% +kinds of searches typically + + + align:start position:0% +kinds of searches typically +and sometimes to do updates better. + + align:start position:0% + + + + align:start position:0% + +And in 006 you've seen an example of + + align:start position:0% +And in 006 you've seen an example of + + + align:start position:0% +And in 006 you've seen an example of +this where you took AVL trees and + + align:start position:0% +this where you took AVL trees and + + + align:start position:0% +this where you took AVL trees and +augmented AVL trees so that every node + + align:start position:0% +augmented AVL trees so that every node + + + align:start position:0% +augmented AVL trees so that every node +knew the number of nodes in that rooted + + align:start position:0% +knew the number of nodes in that rooted + + + align:start position:0% +knew the number of nodes in that rooted +subree. Uh today we're going to see that + + align:start position:0% +subree. Uh today we're going to see that + + + align:start position:0% +subree. Uh today we're going to see that +example but also a bunch of other + + align:start position:0% +example but also a bunch of other + + + align:start position:0% +example but also a bunch of other +examples different types of augmentation + + align:start position:0% +examples different types of augmentation + + + align:start position:0% +examples different types of augmentation +you could do. And we'll start out with a + + align:start position:0% +you could do. And we'll start out with a + + + align:start position:0% +you could do. And we'll start out with a +very simple one which I call easy tree + + align:start position:0% +very simple one which I call easy tree + + + align:start position:0% +very simple one which I call easy tree +augmentation + + align:start position:0% + + + + align:start position:0% + +which will include subree size as a + + align:start position:0% +which will include subree size as a + + + align:start position:0% +which will include subree size as a +special case. + + align:start position:0% + + + + align:start position:0% + +So with easy tree augmentation + + align:start position:0% +So with easy tree augmentation + + + align:start position:0% +So with easy tree augmentation +uh the idea is you have a tree like an + + align:start position:0% +uh the idea is you have a tree like an + + + align:start position:0% +uh the idea is you have a tree like an +AVL tree or 23 tree or something like + + align:start position:0% +AVL tree or 23 tree or something like + + + align:start position:0% +AVL tree or 23 tree or something like +that and you'd like to store for every + + align:start position:0% +that and you'd like to store for every + + + align:start position:0% +that and you'd like to store for every +node x some function of the subree + + align:start position:0% +node x some function of the subree + + + align:start position:0% +node x some function of the subree +rooted at x such as the number of nodes + + align:start position:0% +rooted at x such as the number of nodes + + + align:start position:0% +rooted at x such as the number of nodes +in there or the sum of the weights of + + align:start position:0% +in there or the sum of the weights of + + + align:start position:0% +in there or the sum of the weights of +the nodes or the sum of the squares of + + align:start position:0% +the nodes or the sum of the squares of + + + align:start position:0% +the nodes or the sum of the squares of +the weights or uh the min or the max or + + align:start position:0% +the weights or uh the min or the max or + + + align:start position:0% +the weights or uh the min or the max or +the median maybe I'm not sure uh any + + align:start position:0% +the median maybe I'm not sure uh any + + + align:start position:0% +the median maybe I'm not sure uh any +some some function f of x which is a + + align:start position:0% +some some function f of x which is a + + + align:start position:0% +some some function f of x which is a +function of that maybe not f ofx but we + + align:start position:0% +function of that maybe not f ofx but we + + + align:start position:0% +function of that maybe not f ofx but we +want to compute store some function of + + align:start position:0% +want to compute store some function of + + + align:start position:0% +want to compute store some function of +that sub tree. + + align:start position:0% + + + + align:start position:0% + +Say the goal + + align:start position:0% +Say the goal + + + align:start position:0% +Say the goal +is to store + + align:start position:0% +is to store + + + align:start position:0% +is to store +f of the sub tree rooted at x + + align:start position:0% + + + + align:start position:0% + +uh at each + + align:start position:0% +uh at each + + + align:start position:0% +uh at each +node x + + align:start position:0% +node x + + + align:start position:0% +node x +in a field which I'll call x.f. + + align:start position:0% +in a field which I'll call x.f. + + + align:start position:0% +in a field which I'll call x.f. +So normally nodes have like a left + + align:start position:0% +So normally nodes have like a left + + + align:start position:0% +So normally nodes have like a left +child, right child, parent, but we're + + align:start position:0% +child, right child, parent, but we're + + + align:start position:0% +child, right child, parent, but we're +going to store an extra field x.f for + + align:start position:0% +going to store an extra field x.f for + + + align:start position:0% +going to store an extra field x.f for +some function that you define. This is + + align:start position:0% +some function that you define. This is + + + align:start position:0% +some function that you define. This is +not always possible. + + align:start position:0% +not always possible. + + + align:start position:0% +not always possible. +But here's a case where it is possible. + + align:start position:0% +But here's a case where it is possible. + + + align:start position:0% +But here's a case where it is possible. +That's going to be the easy case. + + align:start position:0% +That's going to be the easy case. + + + align:start position:0% +That's going to be the easy case. +Suppose X.F F can be computed + + align:start position:0% +Suppose X.F F can be computed + + + align:start position:0% +Suppose X.F F can be computed +uh locally using lower information lower + + align:start position:0% +uh locally using lower information lower + + + align:start position:0% +uh locally using lower information lower +nodes + + align:start position:0% + + + + align:start position:0% + +and we'll say let's suppose it can be + + align:start position:0% +and we'll say let's suppose it can be + + + align:start position:0% +and we'll say let's suppose it can be +computed in constant time from + + align:start position:0% +computed in constant time from + + + align:start position:0% +computed in constant time from +information in the node X uh from X's + + align:start position:0% +information in the node X uh from X's + + + align:start position:0% +information in the node X uh from X's +children + + align:start position:0% +children + + + align:start position:0% +children +and + + align:start position:0% +and + + + align:start position:0% +and +uh from + + align:start position:0% +uh from + + + align:start position:0% +uh from +the f value that's stored in the + + align:start position:0% +the f value that's stored in the + + + align:start position:0% +the f value that's stored in the +children. So I'll call that children.f, + + align:start position:0% +children. So I'll call that children.f, + + + align:start position:0% +children. So I'll call that children.f, +but really I mean left child.f, right + + align:start position:0% +but really I mean left child.f, right + + + align:start position:0% +but really I mean left child.f, right +child.f or if you have a two three tree, + + align:start position:0% +child.f or if you have a two three tree, + + + align:start position:0% +child.f or if you have a two three tree, +you have three children potentially and + + align:start position:0% +you have three children potentially and + + + align:start position:0% +you have three children potentially and +the f of each of them. Okay, so suppose + + align:start position:0% +the f of each of them. Okay, so suppose + + + align:start position:0% +the f of each of them. Okay, so suppose +that you can compute x.f uh sort of + + align:start position:0% +that you can compute x.f uh sort of + + + align:start position:0% +that you can compute x.f uh sort of +locally just using one level down in + + align:start position:0% +locally just using one level down in + + + align:start position:0% +locally just using one level down in +constant time. Then as you might expect + + align:start position:0% +constant time. Then as you might expect + + + align:start position:0% +constant time. Then as you might expect +you can update whenever a node needs + + align:start position:0% +you can update whenever a node needs + + + align:start position:0% +you can update whenever a node needs +whenever a node ends up changing. + + align:start position:0% +whenever a node ends up changing. + + + align:start position:0% +whenever a node ends up changing. +Uh so more formally + + align:start position:0% +Uh so more formally + + + align:start position:0% +Uh so more formally +if some set of nodes change + + align:start position:0% + + + + align:start position:0% + +call the set Yes. + + align:start position:0% + + + + align:start position:0% + +uh so uh I'm stating a very general + + align:start position:0% +uh so uh I'm stating a very general + + + align:start position:0% +uh so uh I'm stating a very general +theorem here. If there are some set + + align:start position:0% +theorem here. If there are some set + + + align:start position:0% +theorem here. If there are some set +of nodes which we change something about + + align:start position:0% +of nodes which we change something about + + + align:start position:0% +of nodes which we change something about +them, we change either their F field, uh + + align:start position:0% +them, we change either their F field, uh + + + align:start position:0% +them, we change either their F field, uh +we change some of the data that's in the + + align:start position:0% +we change some of the data that's in the + + + align:start position:0% +we change some of the data that's in the +node or we change we do rotation, move + + align:start position:0% +node or we change we do rotation, move + + + align:start position:0% +node or we change we do rotation, move +some nodes around, then we count the + + align:start position:0% +some nodes around, then we count the + + + align:start position:0% +some nodes around, then we count the +total number of ancestors of these + + align:start position:0% +total number of ancestors of these + + + align:start position:0% +total number of ancestors of these +nodes. So this uh subree those are the + + align:start position:0% +nodes. So this uh subree those are the + + + align:start position:0% +nodes. So this uh subree those are the +nodes that need to be updated because + + align:start position:0% +nodes that need to be updated because + + + align:start position:0% +nodes that need to be updated because +we're assuming we can compute x.f f just + + align:start position:0% +we're assuming we can compute x.f f just + + + align:start position:0% +we're assuming we can compute x.f f just +given the children data. So if these if + + align:start position:0% +given the children data. So if these if + + + align:start position:0% +given the children data. So if these if +this data is changing, we have to update + + align:start position:0% +this data is changing, we have to update + + + align:start position:0% +this data is changing, we have to update +its parents value of f because it + + align:start position:0% +its parents value of f because it + + + align:start position:0% +its parents value of f because it +depends on this child value. We have to + + align:start position:0% +depends on this child value. We have to + + + align:start position:0% +depends on this child value. We have to +update all those parents all the way up + + align:start position:0% +update all those parents all the way up + + + align:start position:0% +update all those parents all the way up +to the root. Okay, so however many nodes + + align:start position:0% +to the root. Okay, so however many nodes + + + align:start position:0% +to the root. Okay, so however many nodes +there are there, that's the total cost. + + align:start position:0% +there are there, that's the total cost. + + + align:start position:0% +there are there, that's the total cost. +Now luckily + + align:start position:0% +Now luckily + + + align:start position:0% +Now luckily +um in an AVL tree or 23 tree, most uh + + align:start position:0% +um in an AVL tree or 23 tree, most uh + + + align:start position:0% +um in an AVL tree or 23 tree, most uh +balanced search structures, the updates + + align:start position:0% +balanced search structures, the updates + + + align:start position:0% +balanced search structures, the updates +you do are very localized. Like when we + + align:start position:0% +you do are very localized. Like when we + + + align:start position:0% +you do are very localized. Like when we +do splits in a two3 tree, we only do it + + align:start position:0% +do splits in a two3 tree, we only do it + + + align:start position:0% +do splits in a two3 tree, we only do it +up a single path to the root. So the + + align:start position:0% +up a single path to the root. So the + + + align:start position:0% +up a single path to the root. So the +number of ancestors here is just going + + align:start position:0% +number of ancestors here is just going + + + align:start position:0% +number of ancestors here is just going +to be log n. Same thing with an AVL + + align:start position:0% +to be log n. Same thing with an AVL + + + align:start position:0% +to be log n. Same thing with an AVL +tree. If you look at the rotations you + + align:start position:0% +tree. If you look at the rotations you + + + align:start position:0% +tree. If you look at the rotations you +do, they're up a single uh leaftoroot + + align:start position:0% +do, they're up a single uh leaftoroot + + + align:start position:0% +do, they're up a single uh leaftoroot +path. + + align:start position:0% +path. + + + align:start position:0% +path. +And so the number of ancestors is that + + align:start position:0% +And so the number of ancestors is that + + + align:start position:0% +And so the number of ancestors is that +that need to be updated is always order + + align:start position:0% +that need to be updated is always order + + + align:start position:0% +that need to be updated is always order +login. Order login things change and + + align:start position:0% +login. Order login things change and + + + align:start position:0% +login. Order login things change and +there's an order login ancestors of + + align:start position:0% +there's an order login ancestors of + + + align:start position:0% +there's an order login ancestors of +them. + + align:start position:0% +them. + + + align:start position:0% +them. +So this is a little more general than we + + align:start position:0% +So this is a little more general than we + + + align:start position:0% +So this is a little more general than we +need but it's just to point out if we + + align:start position:0% +need but it's just to point out if we + + + align:start position:0% +need but it's just to point out if we +did login rotation spread out somewhere + + align:start position:0% +did login rotation spread out somewhere + + + align:start position:0% +did login rotation spread out somewhere +in the tree that would actually be bad + + align:start position:0% +in the tree that would actually be bad + + + align:start position:0% +in the tree that would actually be bad +because the total number of ancestors + + align:start position:0% +because the total number of ancestors + + + align:start position:0% +because the total number of ancestors +could be like log squared right but + + align:start position:0% +could be like log squared right but + + + align:start position:0% +could be like log squared right but +because in the structures we've seen + + align:start position:0% +because in the structures we've seen + + + align:start position:0% +because in the structures we've seen +we just work on a single path to the + + align:start position:0% +we just work on a single path to the + + + align:start position:0% +we just work on a single path to the +root we get log + + align:start position:0% + + + + align:start position:0% + +So, uh, in a little more detail here, + + align:start position:0% +So, uh, in a little more detail here, + + + align:start position:0% +So, uh, in a little more detail here, +whenever we do a rotation in an AVL + + align:start position:0% +whenever we do a rotation in an AVL + + + align:start position:0% +whenever we do a rotation in an AVL +tree, + + align:start position:0% + + + + align:start position:0% + +Uh let's say a b c x y + + align:start position:0% +Uh let's say a b c x y + + + align:start position:0% +Uh let's say a b c x y +remember rotations. It's been a while + + align:start position:0% +remember rotations. It's been a while + + + align:start position:0% +remember rotations. It's been a while +since we've done rotations. Uh so we've + + align:start position:0% +since we've done rotations. Uh so we've + + + align:start position:0% +since we've done rotations. Uh so we've +we've we haven't changed any of the + + align:start position:0% +we've we haven't changed any of the + + + align:start position:0% +we've we haven't changed any of the +nodes in ABC, but we have changed the + + align:start position:0% +nodes in ABC, but we have changed the + + + align:start position:0% +nodes in ABC, but we have changed the +nodes X and Y. Uh, so we're gonna we + + align:start position:0% +nodes X and Y. Uh, so we're gonna we + + + align:start position:0% +nodes X and Y. Uh, so we're gonna we +would have to trigger an update of Y. + + align:start position:0% +would have to trigger an update of Y. + + + align:start position:0% +would have to trigger an update of Y. +First, we'd want to update Y.F. + + align:start position:0% +First, we'd want to update Y.F. + + + align:start position:0% +First, we'd want to update Y.F. +and then we're going to trigger the + + align:start position:0% +and then we're going to trigger the + + + align:start position:0% +and then we're going to trigger the +update to X.F. + + align:start position:0% +update to X.F. + + + align:start position:0% +update to X.F. +And as long as this one can be computed + + align:start position:0% +And as long as this one can be computed + + + align:start position:0% +And as long as this one can be computed +from its children, then we compute Y.F, + + align:start position:0% +from its children, then we compute Y.F, + + + align:start position:0% +from its children, then we compute Y.F, +then we can compute X from its children. + + align:start position:0% +then we can compute X from its children. + + + align:start position:0% +then we can compute X from its children. +Right? So, a constant number of extra + + align:start position:0% +Right? So, a constant number of extra + + + align:start position:0% +Right? So, a constant number of extra +things we need to do whenever we do a + + align:start position:0% +things we need to do whenever we do a + + + align:start position:0% +things we need to do whenever we do a +rotation. And because the rotations lie + + align:start position:0% +rotation. And because the rotations lie + + + align:start position:0% +rotation. And because the rotations lie +in a single path uh total cost that that + + align:start position:0% +in a single path uh total cost that that + + + align:start position:0% +in a single path uh total cost that that +you know once we stop doing the + + align:start position:0% +you know once we stop doing the + + + align:start position:0% +you know once we stop doing the +rotations uh in AVL insert say then we + + align:start position:0% +rotations uh in AVL insert say then we + + + align:start position:0% +rotations uh in AVL insert say then we +still have to keep updating up to the + + align:start position:0% +still have to keep updating up to the + + + align:start position:0% +still have to keep updating up to the +root but there's only login at most + + align:start position:0% +root but there's only login at most + + + align:start position:0% +root but there's only login at most +login nodes to do that. + + align:start position:0% +login nodes to do that. + + + align:start position:0% +login nodes to do that. +Okay, same thing with uh with two three + + align:start position:0% +Okay, same thing with uh with two three + + + align:start position:0% +Okay, same thing with uh with two three +trees. We have a node split. + + align:start position:0% +trees. We have a node split. + + + align:start position:0% +trees. We have a node split. +So we have I guess three keys, four + + align:start position:0% +So we have I guess three keys, four + + + align:start position:0% +So we have I guess three keys, four +children. That's too many. So we split + + align:start position:0% +children. That's too many. So we split + + + align:start position:0% +children. That's too many. So we split +to uh + + align:start position:0% +to uh + + + align:start position:0% +to uh +two nodes and an extra node up here. + + align:start position:0% +two nodes and an extra node up here. + + + align:start position:0% +two nodes and an extra node up here. +Uh then we just trigger an update of + + align:start position:0% +Uh then we just trigger an update of + + + align:start position:0% +Uh then we just trigger an update of +this f value, an update of this fvalue, + + align:start position:0% +this f value, an update of this fvalue, + + + align:start position:0% +this f value, an update of this fvalue, +and an update of that fal. And because + + align:start position:0% +and an update of that fal. And because + + + align:start position:0% +and an update of that fal. And because +that just follows a single path, + + align:start position:0% +that just follows a single path, + + + align:start position:0% +that just follows a single path, +everything's login. + + align:start position:0% +everything's login. + + + align:start position:0% +everything's login. +Okay, so this is a general theorem about + + align:start position:0% +Okay, so this is a general theorem about + + + align:start position:0% +Okay, so this is a general theorem about +augmentation. Any function that's well + + align:start position:0% +augmentation. Any function that's well + + + align:start position:0% +augmentation. Any function that's well +behaved in this sense, we can maintain + + align:start position:0% +behaved in this sense, we can maintain + + + align:start position:0% +behaved in this sense, we can maintain +in AVL trees and 23 trees. + + align:start position:0% +in AVL trees and 23 trees. + + + align:start position:0% +in AVL trees and 23 trees. +And I'll remind you + + align:start position:0% +And I'll remind you + + + align:start position:0% +And I'll remind you +and state a little more generally what + + align:start position:0% +and state a little more generally what + + + align:start position:0% +and state a little more generally what +you did in 006, which are called order + + align:start position:0% +you did in 006, which are called order + + + align:start position:0% +you did in 006, which are called order +statistic trees in the textbook. + + align:start position:0% + + + + align:start position:0% + +So here um we're going to let me first + + align:start position:0% +So here um we're going to let me first + + + align:start position:0% +So here um we're going to let me first +tell you what we're trying to achieve. + + align:start position:0% +tell you what we're trying to achieve. + + + align:start position:0% +tell you what we're trying to achieve. +This is the abstract data type or the + + align:start position:0% +This is the abstract data type or the + + + align:start position:0% +This is the abstract data type or the +interface of the data structure. + + align:start position:0% + + + + align:start position:0% + +uh we want to do insert + + align:start position:0% + + + + align:start position:0% + +uh delete + + align:start position:0% + + + + align:start position:0% + +and uh say successor searches. + + align:start position:0% + + + + align:start position:0% + +It's the usual thing we want out of a + + align:start position:0% +It's the usual thing we want out of a + + + align:start position:0% +It's the usual thing we want out of a +binary search tree. Predecessor 2. Sure. + + align:start position:0% +binary search tree. Predecessor 2. Sure. + + + align:start position:0% +binary search tree. Predecessor 2. Sure. +Uh we want to do rank + + align:start position:0% +Uh we want to do rank + + + align:start position:0% +Uh we want to do rank +of a of a given key which is uh tell me + + align:start position:0% +of a of a given key which is uh tell me + + + align:start position:0% +of a of a given key which is uh tell me +what is the index + + align:start position:0% +what is the index + + + align:start position:0% +what is the index +of that key + + align:start position:0% +of that key + + + align:start position:0% +of that key +uh in the overall sorted order of the + + align:start position:0% +uh in the overall sorted order of the + + + align:start position:0% +uh in the overall sorted order of the +items of the keys. We've talked about + + align:start position:0% +items of the keys. We've talked about + + + align:start position:0% +items of the keys. We've talked about +rank a few times already in this class. + + align:start position:0% +rank a few times already in this class. + + + align:start position:0% +rank a few times already in this class. +Uh depends whether you start at zero or + + align:start position:0% +Uh depends whether you start at zero or + + + align:start position:0% +Uh depends whether you start at zero or +one. But uh let's say we start at one. + + align:start position:0% +one. But uh let's say we start at one. + + + align:start position:0% +one. But uh let's say we start at one. +Uh so if you say rank of the key that + + align:start position:0% +Uh so if you say rank of the key that + + + align:start position:0% +Uh so if you say rank of the key that +happens to be the minimum, you want to + + align:start position:0% +happens to be the minimum, you want to + + + align:start position:0% +happens to be the minimum, you want to +get one. If you say rank of the key that + + align:start position:0% +get one. If you say rank of the key that + + + align:start position:0% +get one. If you say rank of the key that +happens to be the median, you want to + + align:start position:0% +happens to be the median, you want to + + + align:start position:0% +happens to be the median, you want to +get n over two plus one. Uh and so on. + + align:start position:0% +get n over two plus one. Uh and so on. + + + align:start position:0% +get n over two plus one. Uh and so on. +Okay. So that's a natural thing you + + align:start position:0% +Okay. So that's a natural thing you + + + align:start position:0% +Okay. So that's a natural thing you +might want to find out. uh and the + + align:start position:0% +might want to find out. uh and the + + + align:start position:0% +might want to find out. uh and the +converse operation is select + + align:start position:0% +converse operation is select + + + align:start position:0% +converse operation is select +say of I which is give me the key of + + align:start position:0% +say of I which is give me the key of + + + align:start position:0% +say of I which is give me the key of +rank I. + + align:start position:0% + + + + align:start position:0% + +Okay, we've talked about uh select as an + + align:start position:0% +Okay, we've talked about uh select as an + + + align:start position:0% +Okay, we've talked about uh select as an +offline operation given an array uh find + + align:start position:0% +offline operation given an array uh find + + + align:start position:0% +offline operation given an array uh find +me the median or find me the n over 7th + + align:start position:0% +me the median or find me the n over 7th + + + align:start position:0% +me the median or find me the n over 7th +uh rank item and we can do that in + + align:start position:0% +uh rank item and we can do that in + + + align:start position:0% +uh rank item and we can do that in +linear time given no data structure + + align:start position:0% +linear time given no data structure + + + align:start position:0% +linear time given no data structure +here. We want a data structure so that + + align:start position:0% +here. We want a data structure so that + + + align:start position:0% +here. We want a data structure so that +we can find the median or the uh seventh + + align:start position:0% +we can find the median or the uh seventh + + + align:start position:0% +we can find the median or the uh seventh +item or the n over7th key uh whatever in + + align:start position:0% +item or the n over7th key uh whatever in + + + align:start position:0% +item or the n over7th key uh whatever in +login time. We want to do all of these + + align:start position:0% +login time. We want to do all of these + + + align:start position:0% +login time. We want to do all of these +in + + align:start position:0% +in + + + align:start position:0% +in +login per operation. + + align:start position:0% + + + + align:start position:0% + +Okay, so in particular rank of select of + + align:start position:0% +Okay, so in particular rank of select of + + + align:start position:0% +Okay, so in particular rank of select of +I should equal I, right? We're trying to + + align:start position:0% +I should equal I, right? We're trying to + + + align:start position:0% +I should equal I, right? We're trying to +find the item of that rank. + + align:start position:0% + + + + align:start position:0% + +So far so good. Uh and + + align:start position:0% +So far so good. Uh and + + + align:start position:0% +So far so good. Uh and +just to plug these two parts together, + + align:start position:0% +just to plug these two parts together, + + + align:start position:0% +just to plug these two parts together, +we have this data structure augmentation + + align:start position:0% +we have this data structure augmentation + + + align:start position:0% +we have this data structure augmentation +tool. We have this goal we want to + + align:start position:0% +tool. We have this goal we want to + + + align:start position:0% +tool. We have this goal we want to +achieve. We're going to achieve this + + align:start position:0% +achieve. We're going to achieve this + + + align:start position:0% +achieve. We're going to achieve this +goal by applying this technique where f + + align:start position:0% +goal by applying this technique where f + + + align:start position:0% +goal by applying this technique where f +is just the subree size, the number of + + align:start position:0% +is just the subree size, the number of + + + align:start position:0% +is just the subree size, the number of +nodes in that subree because that will + + align:start position:0% +nodes in that subree because that will + + + align:start position:0% +nodes in that subree because that will +let us compute rank. + + align:start position:0% +let us compute rank. + + + align:start position:0% +let us compute rank. +So, we're going to use + + align:start position:0% +So, we're going to use + + + align:start position:0% +So, we're going to use +uh easy tree augmentation + + align:start position:0% + + + + align:start position:0% + +with f + + align:start position:0% +with f + + + align:start position:0% +with f +of + + align:start position:0% +of + + + align:start position:0% +of +subree + + align:start position:0% + + + + align:start position:0% + +equal to the number of nodes in the + + align:start position:0% +equal to the number of nodes in the + + + align:start position:0% +equal to the number of nodes in the +subree. + + align:start position:0% + + + + align:start position:0% + +So in order for this to apply we need to + + align:start position:0% +So in order for this to apply we need to + + + align:start position:0% +So in order for this to apply we need to +check that given a node x uh we can + + align:start position:0% +check that given a node x uh we can + + + align:start position:0% +check that given a node x uh we can +compute x do just using its children. + + align:start position:0% +compute x do just using its children. + + + align:start position:0% +compute x do just using its children. +This is easy. Uh + + align:start position:0% +This is easy. Uh + + + align:start position:0% +This is easy. Uh +we just add everything up. So x do would + + align:start position:0% +we just add everything up. So x do would + + + align:start position:0% +we just add everything up. So x do would +be equal to 1 that's for x plus the sum + + align:start position:0% +be equal to 1 that's for x plus the sum + + + align:start position:0% +be equal to 1 that's for x plus the sum +of cf + + align:start position:0% +of cf + + + align:start position:0% +of cf +for every child c. + + align:start position:0% + + + + align:start position:0% + +I'll write this as a python + + align:start position:0% +I'll write this as a python + + + align:start position:0% +I'll write this as a python +interpolation + + align:start position:0% +interpolation + + + align:start position:0% +interpolation +so it looks a little more like an + + align:start position:0% +so it looks a little more like an + + + align:start position:0% +so it looks a little more like an +algorithm. Um I'm trying to be generic + + align:start position:0% +algorithm. Um I'm trying to be generic + + + align:start position:0% +algorithm. Um I'm trying to be generic +here. If it's a binary search tree you + + align:start position:0% +here. If it's a binary search tree you + + + align:start position:0% +here. If it's a binary search tree you +just do x.left.f + + align:start position:0% +just do x.left.f + + + align:start position:0% +just do x.left.f +f plus x.right.f. But this will work + + align:start position:0% +f plus x.right.f. But this will work + + + align:start position:0% +f plus x.right.f. But this will work +also for two three trees. Pick your + + align:start position:0% +also for two three trees. Pick your + + + align:start position:0% +also for two three trees. Pick your +favorite uh data structure. As long as + + align:start position:0% +favorite uh data structure. As long as + + + align:start position:0% +favorite uh data structure. As long as +there's a constant number of children, + + align:start position:0% +there's a constant number of children, + + + align:start position:0% +there's a constant number of children, +then uh this will take constant time. So + + align:start position:0% +then uh this will take constant time. So + + + align:start position:0% +then uh this will take constant time. So +we satisfy this condition. So we can do + + align:start position:0% +we satisfy this condition. So we can do + + + align:start position:0% +we satisfy this condition. So we can do +easy tree augmentation. And now we know + + align:start position:0% +easy tree augmentation. And now we know + + + align:start position:0% +easy tree augmentation. And now we know +we have subree sizes. So given any node, + + align:start position:0% +we have subree sizes. So given any node, + + + align:start position:0% +we have subree sizes. So given any node, +we know the number of children sorry the + + align:start position:0% +we know the number of children sorry the + + + align:start position:0% +we know the number of children sorry the +number of descendants below that node. + + align:start position:0% +number of descendants below that node. + + + align:start position:0% +number of descendants below that node. +So that's cool. It lets us compute rank + + align:start position:0% +So that's cool. It lets us compute rank + + + align:start position:0% +So that's cool. It lets us compute rank +and select. I'll just uh give you those + + align:start position:0% +and select. I'll just uh give you those + + + align:start position:0% +and select. I'll just uh give you those +algorithms quickly. + + align:start position:0% +algorithms quickly. + + + align:start position:0% +algorithms quickly. +We can check that they're log end time. + + align:start position:0% + + + + align:start position:0% + +Uh + + align:start position:0% + + + + align:start position:0% + +yeah, so the the the idea is pretty + + align:start position:0% +yeah, so the the the idea is pretty + + + align:start position:0% +yeah, so the the the idea is pretty +simple. + + align:start position:0% +simple. + + + align:start position:0% +simple. +You have some key. Let's think about + + align:start position:0% +You have some key. Let's think about + + + align:start position:0% +You have some key. Let's think about +binary trees uh now because it's a + + align:start position:0% +binary trees uh now because it's a + + + align:start position:0% +binary trees uh now because it's a +little bit easier. Um we have some item + + align:start position:0% +little bit easier. Um we have some item + + + align:start position:0% +little bit easier. Um we have some item +X. + + align:start position:0% +X. + + + align:start position:0% +X. +It has a left subree, a right subree. + + align:start position:0% +It has a left subree, a right subree. + + + align:start position:0% +It has a left subree, a right subree. +And now let's uh let's look up from X. + + align:start position:0% +And now let's uh let's look up from X. + + + align:start position:0% +And now let's uh let's look up from X. +Just keep calling uh X.parent. + + align:start position:0% +Just keep calling uh X.parent. + + + align:start position:0% +Just keep calling uh X.parent. +So sometimes the parent is to the right + + align:start position:0% +So sometimes the parent is to the right + + + align:start position:0% +So sometimes the parent is to the right +of us and sometimes the parent is to the + + align:start position:0% +of us and sometimes the parent is to the + + + align:start position:0% +of us and sometimes the parent is to the +left of us. + + align:start position:0% +left of us. + + + align:start position:0% +left of us. +Okay, I'm going to draw this in a kind + + align:start position:0% +Okay, I'm going to draw this in a kind + + + align:start position:0% +Okay, I'm going to draw this in a kind +of funny way, + + align:start position:0% + + + + align:start position:0% + +but this funny way has a very special + + align:start position:0% +but this funny way has a very special + + + align:start position:0% +but this funny way has a very special +property + + align:start position:0% +property + + + align:start position:0% +property +which is that the xcoordinate in this + + align:start position:0% +which is that the xcoordinate in this + + + align:start position:0% +which is that the xcoordinate in this +diagram is the key value or is the + + align:start position:0% +diagram is the key value or is the + + + align:start position:0% +diagram is the key value or is the +sorted order of the keys. Right? + + align:start position:0% +sorted order of the keys. Right? + + + align:start position:0% +sorted order of the keys. Right? +Everything in the left subree of X is + + align:start position:0% +Everything in the left subree of X is + + + align:start position:0% +Everything in the left subree of X is +has a value less than X. If we say all + + align:start position:0% +has a value less than X. If we say all + + + align:start position:0% +has a value less than X. If we say all +the keys are different, everything to + + align:start position:0% +the keys are different, everything to + + + align:start position:0% +the keys are different, everything to +the right of X has a value greater than + + align:start position:0% +the right of X has a value greater than + + + align:start position:0% +the right of X has a value greater than +X. If the parent if x was the left child + + align:start position:0% +X. If the parent if x was the left child + + + align:start position:0% +X. If the parent if x was the left child +of its parent that means this thing is + + align:start position:0% +of its parent that means this thing is + + + align:start position:0% +of its parent that means this thing is +also greater than x. + + align:start position:0% +also greater than x. + + + align:start position:0% +also greater than x. +Uh and if we follow a parent and it was + + align:start position:0% +Uh and if we follow a parent and it was + + + align:start position:0% +Uh and if we follow a parent and it was +and this was the right child of that + + align:start position:0% +and this was the right child of that + + + align:start position:0% +and this was the right child of that +parent that means this thing is less + + align:start position:0% +parent that means this thing is less + + + align:start position:0% +parent that means this thing is less +than x. So that's why I drew it all the + + align:start position:0% +than x. So that's why I drew it all the + + + align:start position:0% +than x. So that's why I drew it all the +way over to the left. This thing is also + + align:start position:0% +way over to the left. This thing is also + + + align:start position:0% +way over to the left. This thing is also +less than x because it was a I'll call + + align:start position:0% +less than x because it was a I'll call + + + align:start position:0% +less than x because it was a I'll call +it a left parent. Here we have a right + + align:start position:0% +it a left parent. Here we have a right + + + align:start position:0% +it a left parent. Here we have a right +parent. So that means this is something + + align:start position:0% +parent. So that means this is something + + + align:start position:0% +parent. So that means this is something +greater than x. + + align:start position:0% +greater than x. + + + align:start position:0% +greater than x. +And over here we have a left parent. So + + align:start position:0% +And over here we have a left parent. So + + + align:start position:0% +And over here we have a left parent. So +this is something less than x. Let's say + + align:start position:0% +this is something less than x. Let's say + + + align:start position:0% +this is something less than x. Let's say +that's the root. In general, there's + + align:start position:0% +that's the root. In general, there's + + + align:start position:0% +that's the root. In general, there's +going to be some left edges and some + + align:start position:0% +going to be some left edges and some + + + align:start position:0% +going to be some left edges and some +right edges. As we go up, these arrows + + align:start position:0% +right edges. As we go up, these arrows + + + align:start position:0% +right edges. As we go up, these arrows +will go either left or right in a binary + + align:start position:0% +will go either left or right in a binary + + + align:start position:0% +will go either left or right in a binary +tree. So the rank of x is just uh one + + align:start position:0% +tree. So the rank of x is just uh one + + + align:start position:0% +tree. So the rank of x is just uh one +plus the number of nodes that are less + + align:start position:0% +plus the number of nodes that are less + + + align:start position:0% +plus the number of nodes that are less +than x. Number of keys that are less + + align:start position:0% +than x. Number of keys that are less + + + align:start position:0% +than x. Number of keys that are less +than x. So there's these guys, + + align:start position:0% +than x. So there's these guys, + + + align:start position:0% +than x. So there's these guys, +there's these guys, and there's whatever + + align:start position:0% +there's these guys, and there's whatever + + + align:start position:0% +there's these guys, and there's whatever +is hanging off. Okay, here I've almost + + align:start position:0% +is hanging off. Okay, here I've almost + + + align:start position:0% +is hanging off. Okay, here I've almost +violated my x coordinate rule. If I make + + align:start position:0% +violated my x coordinate rule. If I make + + + align:start position:0% +violated my x coordinate rule. If I make +these really narrow, that's right. + + align:start position:0% +these really narrow, that's right. + + + align:start position:0% +these really narrow, that's right. +So all of these things uh all of these + + align:start position:0% +So all of these things uh all of these + + + align:start position:0% +So all of these things uh all of these +nodes in the left sub trees of these + + align:start position:0% +nodes in the left sub trees of these + + + align:start position:0% +nodes in the left sub trees of these +less than x nodes will also be less than + + align:start position:0% +less than x nodes will also be less than + + + align:start position:0% +less than x nodes will also be less than +x. If you think about these other sub + + align:start position:0% +x. If you think about these other sub + + + align:start position:0% +x. If you think about these other sub +trees, they're going to be bigger than + + align:start position:0% +trees, they're going to be bigger than + + + align:start position:0% +trees, they're going to be bigger than +x. So we don't really care about them. + + align:start position:0% +x. So we don't really care about them. + + + align:start position:0% +x. So we don't really care about them. +So we just want to count up + + align:start position:0% +So we just want to count up + + + align:start position:0% +So we just want to count up +all + + align:start position:0% +all + + + align:start position:0% +all +of these nodes + + align:start position:0% +of these nodes + + + align:start position:0% +of these nodes +and all of these nodes. + + align:start position:0% + + + + align:start position:0% + +So the algorithm to do that is pretty + + align:start position:0% +So the algorithm to do that is pretty + + + align:start position:0% +So the algorithm to do that is pretty +simple. + + align:start position:0% + + + + align:start position:0% + +Uh we're just going to + + align:start position:0% +Uh we're just going to + + + align:start position:0% +Uh we're just going to +uh start out with + + align:start position:0% + + + + align:start position:0% + +I'm going to switch from this f notation + + align:start position:0% +I'm going to switch from this f notation + + + align:start position:0% +I'm going to switch from this f notation +to size. That's a little more natural. + + align:start position:0% +to size. That's a little more natural. + + + align:start position:0% +to size. That's a little more natural. +In general, you might have many + + align:start position:0% +In general, you might have many + + + align:start position:0% +In general, you might have many +functions. So size is the usual notion + + align:start position:0% +functions. So size is the usual notion + + + align:start position:0% +functions. So size is the usual notion +for usual notation for subree size. + + align:start position:0% +for usual notation for subree size. + + + align:start position:0% +for usual notation for subree size. +Uh so we start out by counting up how + + align:start position:0% +Uh so we start out by counting up how + + + align:start position:0% +Uh so we start out by counting up how +many items are here. And if we want to + + align:start position:0% +many items are here. And if we want to + + + align:start position:0% +many items are here. And if we want to +start at a rank of one, if the min has + + align:start position:0% +start at a rank of one, if the min has + + + align:start position:0% +start at a rank of one, if the min has +rank one, then I should also do plus one + + align:start position:0% +rank one, then I should also do plus one + + + align:start position:0% +rank one, then I should also do plus one +for x itself. If you wanted to start at + + align:start position:0% +for x itself. If you wanted to start at + + + align:start position:0% +for x itself. If you wanted to start at +zero, you just emit that plus one. + + align:start position:0% +zero, you just emit that plus one. + + + align:start position:0% +zero, you just emit that plus one. +And then all I do is walk up from x to + + align:start position:0% +And then all I do is walk up from x to + + + align:start position:0% +And then all I do is walk up from x to +the root of the tree. + + align:start position:0% +the root of the tree. + + + align:start position:0% +the root of the tree. +And uh whenever + + align:start position:0% +And uh whenever + + + align:start position:0% +And uh whenever +we go left + + align:start position:0% + + + + align:start position:0% + +uh from say x to x prime. So that means + + align:start position:0% +uh from say x to x prime. So that means + + + align:start position:0% +uh from say x to x prime. So that means +we have an x prime. It's right child is + + align:start position:0% +we have an x prime. It's right child is + + + align:start position:0% +we have an x prime. It's right child is +x. And so when we went from x to its + + align:start position:0% +x. And so when we went from x to its + + + align:start position:0% +x. And so when we went from x to its +parent, we went to the left. Uh then we + + align:start position:0% +parent, we went to the left. Uh then we + + + align:start position:0% +parent, we went to the left. Uh then we +say uh rank + + align:start position:0% +say uh rank + + + align:start position:0% +say uh rank +plus equals + + align:start position:0% +plus equals + + + align:start position:0% +plus equals +uh x prime. left + + align:start position:0% +uh x prime. left + + + align:start position:0% +uh x prime. left +dots size + + align:start position:0% + + + + align:start position:0% + +uh plus one for x prime itself. + + align:start position:0% +uh plus one for x prime itself. + + + align:start position:0% +uh plus one for x prime itself. +Okay, maybe there maybe x x xp prime. + + align:start position:0% +Okay, maybe there maybe x x xp prime. + + + align:start position:0% +Okay, maybe there maybe x x xp prime. +size is zero. Maybe there's no nodes + + align:start position:0% +size is zero. Maybe there's no nodes + + + align:start position:0% +size is zero. Maybe there's no nodes +over there. But at the very least, we + + align:start position:0% +over there. But at the very least, we + + + align:start position:0% +over there. But at the very least, we +have to count those nodes that are to + + align:start position:0% +have to count those nodes that are to + + + align:start position:0% +have to count those nodes that are to +the left of us. And if there anything + + align:start position:0% +the left of us. And if there anything + + + align:start position:0% +the left of us. And if there anything +down here, we add up all those things. + + align:start position:0% +down here, we add up all those things. + + + align:start position:0% +down here, we add up all those things. +So that lets us compute rank. How long + + align:start position:0% +So that lets us compute rank. How long + + + align:start position:0% +So that lets us compute rank. How long +does it take? Well, we're just walking + + align:start position:0% +does it take? Well, we're just walking + + + align:start position:0% +does it take? Well, we're just walking +up one path from a leaf to root or not + + align:start position:0% +up one path from a leaf to root or not + + + align:start position:0% +up one path from a leaf to root or not +necessarily leaf but from some node x to + + align:start position:0% +necessarily leaf but from some node x to + + + align:start position:0% +necessarily leaf but from some node x to +the root. And as long as we're using a + + align:start position:0% +the root. And as long as we're using a + + + align:start position:0% +the root. And as long as we're using a +balanced structure like AVL trees, uh I + + align:start position:0% +balanced structure like AVL trees, uh I + + + align:start position:0% +balanced structure like AVL trees, uh I +guess I want binary here. So let's say + + align:start position:0% +guess I want binary here. So let's say + + + align:start position:0% +guess I want binary here. So let's say +AVL trees uh then this will take login + + align:start position:0% +AVL trees uh then this will take login + + + align:start position:0% +AVL trees uh then this will take login +time. So I'm spending constant work per + + align:start position:0% +time. So I'm spending constant work per + + + align:start position:0% +time. So I'm spending constant work per +step and there's login steps. + + align:start position:0% +step and there's login steps. + + + align:start position:0% +step and there's login steps. +Clear? + + align:start position:0% +Clear? + + + align:start position:0% +Clear? +So that's good old rank. + + align:start position:0% +So that's good old rank. + + + align:start position:0% +So that's good old rank. +Easy to do once you have subree size. + + align:start position:0% +Easy to do once you have subree size. + + + align:start position:0% +Easy to do once you have subree size. +Let's do select for fun. + + align:start position:0% + + + + align:start position:0% + +This may seem like review, but I drew + + align:start position:0% +This may seem like review, but I drew + + + align:start position:0% +This may seem like review, but I drew +out this picture explicitly because + + align:start position:0% +out this picture explicitly because + + + align:start position:0% +out this picture explicitly because +we're going to do it a lot today. We'll + + align:start position:0% +we're going to do it a lot today. We'll + + + align:start position:0% +we're going to do it a lot today. We'll +have pictures like this a bunch of + + align:start position:0% +have pictures like this a bunch of + + + align:start position:0% +have pictures like this a bunch of +times. really helps to think about where + + align:start position:0% +times. really helps to think about where + + + align:start position:0% +times. really helps to think about where +the nodes are, which ones are less than + + align:start position:0% +the nodes are, which ones are less than + + + align:start position:0% +the nodes are, which ones are less than +x, which ones are greater than x. + + align:start position:0% +x, which ones are greater than x. + + + align:start position:0% +x, which ones are greater than x. +Okay, let's do select first. + + align:start position:0% + + + + align:start position:0% + +This you may not have seen in 006. + + align:start position:0% + + + + align:start position:0% + +So, we're going to do the reverse. We're + + align:start position:0% +So, we're going to do the reverse. We're + + + align:start position:0% +So, we're going to do the reverse. We're +going to start at the root and we're + + align:start position:0% +going to start at the root and we're + + + align:start position:0% +going to start at the root and we're +going to walk down. + + align:start position:0% +going to walk down. + + + align:start position:0% +going to walk down. +Sounds easy enough. Uh, but now walking + + align:start position:0% +Sounds easy enough. Uh, but now walking + + + align:start position:0% +Sounds easy enough. Uh, but now walking +down is kind of like doing a search, but + + align:start position:0% +down is kind of like doing a search, but + + + align:start position:0% +down is kind of like doing a search, but +we don't have a key we're searching for. + + align:start position:0% +we don't have a key we're searching for. + + + align:start position:0% +we don't have a key we're searching for. +We have a rank we're searching for. + + align:start position:0% +We have a rank we're searching for. + + + align:start position:0% +We have a rank we're searching for. +So, uh what is that rank? + + align:start position:0% + + + + align:start position:0% + +Rank is I. Okay. So, uh on the other + + align:start position:0% +Rank is I. Okay. So, uh on the other + + + align:start position:0% +Rank is I. Okay. So, uh on the other +hand, we have the node X. We'd like to + + align:start position:0% +hand, we have the node X. We'd like to + + + align:start position:0% +hand, we have the node X. We'd like to +know the rank of X and compare that to + + align:start position:0% +know the rank of X and compare that to + + + align:start position:0% +know the rank of X and compare that to +I. That will tell us whether we should + + align:start position:0% +I. That will tell us whether we should + + + align:start position:0% +I. That will tell us whether we should +go left or go right or whether we happen + + align:start position:0% +go left or go right or whether we happen + + + align:start position:0% +go left or go right or whether we happen +to find the item. Now, one possibility + + align:start position:0% +to find the item. Now, one possibility + + + align:start position:0% +to find the item. Now, one possibility +is we call rank of X to find the rank of + + align:start position:0% +is we call rank of X to find the rank of + + + align:start position:0% +is we call rank of X to find the rank of +X. But that's dangerous. Uh because I'm + + align:start position:0% +X. But that's dangerous. Uh because I'm + + + align:start position:0% +X. But that's dangerous. Uh because I'm +going to have a a for loop here. And if + + align:start position:0% +going to have a a for loop here. And if + + + align:start position:0% +going to have a a for loop here. And if +and it's going to take log n iterations. + + align:start position:0% +and it's going to take log n iterations. + + + align:start position:0% +and it's going to take log n iterations. +If at every iteration I'm computing rank + + align:start position:0% +If at every iteration I'm computing rank + + + align:start position:0% +If at every iteration I'm computing rank +of x and rank cost log n then overall + + align:start position:0% +of x and rank cost log n then overall + + + align:start position:0% +of x and rank cost log n then overall +cost might be log squared n. So I can't + + align:start position:0% +cost might be log squared n. So I can't + + + align:start position:0% +cost might be log squared n. So I can't +afford to I want to know what the rank + + align:start position:0% +afford to I want to know what the rank + + + align:start position:0% +afford to I want to know what the rank +of x is + + align:start position:0% +of x is + + + align:start position:0% +of x is +but I can't afford to say rank open x + + align:start position:0% +but I can't afford to say rank open x + + + align:start position:0% +but I can't afford to say rank open x +because that recursive call will be too + + align:start position:0% +because that recursive call will be too + + + align:start position:0% +because that recursive call will be too +expensive. So what is the rank of X in + + align:start position:0% +expensive. So what is the rank of X in + + + align:start position:0% +expensive. So what is the rank of X in +this case? This is a little special. + + align:start position:0% +this case? This is a little special. + + + align:start position:0% +this case? This is a little special. +What's that? + + align:start position:0% +What's that? + + + align:start position:0% +What's that? +Number of left children plus one. + + align:start position:0% +Number of left children plus one. + + + align:start position:0% +Number of left children plus one. +Number of left or the size of the left + + align:start position:0% +Number of left or the size of the left + + + align:start position:0% +Number of left or the size of the left +subree plus one. Yeah. + + align:start position:0% + + + + align:start position:0% + +Plus one if we're counting starting at + + align:start position:0% +Plus one if we're counting starting at + + + align:start position:0% +Plus one if we're counting starting at +one. Very good. + + align:start position:0% + + + + align:start position:0% + +I'm slowly getting better. Um didn't hit + + align:start position:0% +I'm slowly getting better. Um didn't hit + + + align:start position:0% +I'm slowly getting better. Um didn't hit +anyone this time. Okay. So at least for + + align:start position:0% +anyone this time. Okay. So at least for + + + align:start position:0% +anyone this time. Okay. So at least for +the root, this is the rank and that only + + align:start position:0% +the root, this is the rank and that only + + + align:start position:0% +the root, this is the rank and that only +takes us constant time in this special + + align:start position:0% +takes us constant time in this special + + + align:start position:0% +takes us constant time in this special +case. We'll have to check that it still + + align:start position:0% +case. We'll have to check that it still + + + align:start position:0% +case. We'll have to check that it still +holds after I do the loop, but it will. + + align:start position:0% +holds after I do the loop, but it will. + + + align:start position:0% +holds after I do the loop, but it will. +Uh so cool. Now there are three cases. U + + align:start position:0% +Uh so cool. Now there are three cases. U + + + align:start position:0% +Uh so cool. Now there are three cases. U +if I equals rank, if the rank we're + + align:start position:0% +if I equals rank, if the rank we're + + + align:start position:0% +if I equals rank, if the rank we're +searching for is the rank that we happen + + align:start position:0% +searching for is the rank that we happen + + + align:start position:0% +searching for is the rank that we happen +to have, then we're done, right? We just + + align:start position:0% +to have, then we're done, right? We just + + + align:start position:0% +to have, then we're done, right? We just +return x. + + align:start position:0% +return x. + + + align:start position:0% +return x. +Okay, that's the easy case. more more + + align:start position:0% +Okay, that's the easy case. more more + + + align:start position:0% +Okay, that's the easy case. more more +likely is that I will be either less + + align:start position:0% +likely is that I will be either less + + + align:start position:0% +likely is that I will be either less +than or greater than the rank of X. + + align:start position:0% + + + + align:start position:0% + +Okay. Uh so if I is less than the rank, + + align:start position:0% +Okay. Uh so if I is less than the rank, + + + align:start position:0% +Okay. Uh so if I is less than the rank, +this is fairly easy. We just say uh X= + + align:start position:0% +this is fairly easy. We just say uh X= + + + align:start position:0% +this is fairly easy. We just say uh X= +X.ft. + + align:start position:0% + + + + align:start position:0% + +Uh did I get that right? Yeah. Um in + + align:start position:0% +Uh did I get that right? Yeah. Um in + + + align:start position:0% +Uh did I get that right? Yeah. Um in +this case the rank so here we have x + + align:start position:0% +this case the rank so here we have x + + + align:start position:0% +this case the rank so here we have x +it's at rank rank and then we have the + + align:start position:0% +it's at rank rank and then we have the + + + align:start position:0% +it's at rank rank and then we have the +left subree uh and the right subree and + + align:start position:0% +left subree uh and the right subree and + + + align:start position:0% +left subree uh and the right subree and +so if the rank we're searching for is + + align:start position:0% +so if the rank we're searching for is + + + align:start position:0% +so if the rank we're searching for is +less than rank that means we know it's + + align:start position:0% +less than rank that means we know it's + + + align:start position:0% +less than rank that means we know it's +in here so we should go left and if we + + align:start position:0% +in here so we should go left and if we + + + align:start position:0% +in here so we should go left and if we +just set x= x.ft uh you might ask well + + align:start position:0% +just set x= x.ft uh you might ask well + + + align:start position:0% +just set x= x.ft uh you might ask well +what rank are we searching for in here? + + align:start position:0% +what rank are we searching for in here? + + + align:start position:0% +what rank are we searching for in here? +Well exactly the same rank fine that's + + align:start position:0% +Well exactly the same rank fine that's + + + align:start position:0% +Well exactly the same rank fine that's +the easy case. uh in the other situation + + align:start position:0% +the easy case. uh in the other situation + + + align:start position:0% +the easy case. uh in the other situation +if we're searching in here we're + + align:start position:0% +if we're searching in here we're + + + align:start position:0% +if we're searching in here we're +searching for a rank greater than rank + + align:start position:0% +searching for a rank greater than rank + + + align:start position:0% +searching for a rank greater than rank +uh then I want to go right + + align:start position:0% +uh then I want to go right + + + align:start position:0% +uh then I want to go right +but the new rank that I'm searching for + + align:start position:0% +but the new rank that I'm searching for + + + align:start position:0% +but the new rank that I'm searching for +is local to this subree I'm searching + + align:start position:0% +is local to this subree I'm searching + + + align:start position:0% +is local to this subree I'm searching +for uh I minus this stuff this stuff is + + align:start position:0% +for uh I minus this stuff this stuff is + + + align:start position:0% +for uh I minus this stuff this stuff is +rank so I'm going to let I be I minus + + align:start position:0% +rank so I'm going to let I be I minus + + + align:start position:0% +rank so I'm going to let I be I minus +rank + + align:start position:0% +rank + + + align:start position:0% +rank +sure I don't have any off by one errors. + + align:start position:0% +sure I don't have any off by one errors. + + + align:start position:0% +sure I don't have any off by one errors. +Yeah, that's to be right. + + align:start position:0% +Yeah, that's to be right. + + + align:start position:0% +Yeah, that's to be right. +Okay. And then I do a loop. So I'll + + align:start position:0% +Okay. And then I do a loop. So I'll + + + align:start position:0% +Okay. And then I do a loop. So I'll +write repeat. + + align:start position:0% + + + + align:start position:0% + +Uh so then I'm going to go up here and + + align:start position:0% +Uh so then I'm going to go up here and + + + align:start position:0% +Uh so then I'm going to go up here and +say okay now relative to this thing what + + align:start position:0% +say okay now relative to this thing what + + + align:start position:0% +say okay now relative to this thing what +is the rank of the root of this subree? + + align:start position:0% +is the rank of the root of this subree? + + + align:start position:0% +is the rank of the root of this subree? +Uh well it's again going to be that + + align:start position:0% +Uh well it's again going to be that + + + align:start position:0% +Uh well it's again going to be that +node.left size plus one. And now I have + + align:start position:0% +node.left size plus one. And now I have + + + align:start position:0% +node.left size plus one. And now I have +the new rank I'm searching for I. And I + + align:start position:0% +the new rank I'm searching for I. And I + + + align:start position:0% +the new rank I'm searching for I. And I +just keep going. You could write this + + align:start position:0% +just keep going. You could write this + + + align:start position:0% +just keep going. You could write this +recursively if you like, but here's an + + align:start position:0% +recursively if you like, but here's an + + + align:start position:0% +recursively if you like, but here's an +iterative version. + + align:start position:0% +iterative version. + + + align:start position:0% +iterative version. +So it's actually very familiar to the + + align:start position:0% +So it's actually very familiar to the + + + align:start position:0% +So it's actually very familiar to the +select algorithm that we had uh like + + align:start position:0% +select algorithm that we had uh like + + + align:start position:0% +select algorithm that we had uh like +when we did deterministic linear time + + align:start position:0% +when we did deterministic linear time + + + align:start position:0% +when we did deterministic linear time +median finding or randomized median + + align:start position:0% +median finding or randomized median + + + align:start position:0% +median finding or randomized median +finding. U they had a very similar kind + + align:start position:0% +finding. U they had a very similar kind + + + align:start position:0% +finding. U they had a very similar kind +of recursion but in that case we're + + align:start position:0% +of recursion but in that case we're + + + align:start position:0% +of recursion but in that case we're +spending linear time to do the partition + + align:start position:0% +spending linear time to do the partition + + + align:start position:0% +spending linear time to do the partition +and that was expensive. Here we're just + + align:start position:0% +and that was expensive. Here we're just + + + align:start position:0% +and that was expensive. Here we're just +spending constant time at each node and + + align:start position:0% +spending constant time at each node and + + + align:start position:0% +spending constant time at each node and +so the overall cost is login. + + align:start position:0% +so the overall cost is login. + + + align:start position:0% +so the overall cost is login. +So that's nice. Any questions about + + align:start position:0% +So that's nice. Any questions about + + + align:start position:0% +So that's nice. Any questions about +that? + + align:start position:0% + + + + align:start position:0% + +Okay. Uh I have a note here. Subree size + + align:start position:0% +Okay. Uh I have a note here. Subree size + + + align:start position:0% +Okay. Uh I have a note here. Subree size +is obvious once you know that that's + + align:start position:0% +is obvious once you know that that's + + + align:start position:0% +is obvious once you know that that's +what you should do. Another natural + + align:start position:0% +what you should do. Another natural + + + align:start position:0% +what you should do. Another natural +thing to try to do would be to augment + + align:start position:0% +thing to try to do would be to augment + + + align:start position:0% +thing to try to do would be to augment +for each node what is the rank of that + + align:start position:0% +for each node what is the rank of that + + + align:start position:0% +for each node what is the rank of that +node because then rank is really easy to + + align:start position:0% +node because then rank is really easy to + + + align:start position:0% +node because then rank is really easy to +find. And then select would basically be + + align:start position:0% +find. And then select would basically be + + + align:start position:0% +find. And then select would basically be +a regular search. I just look at the + + align:start position:0% +a regular search. I just look at the + + + align:start position:0% +a regular search. I just look at the +rank of the root. I see whether the rank + + align:start position:0% +rank of the root. I see whether the rank + + + align:start position:0% +rank of the root. I see whether the rank +I'm looking for is too big or too small + + align:start position:0% +I'm looking for is too big or too small + + + align:start position:0% +I'm looking for is too big or too small +and I go left or right accordingly. What + + align:start position:0% +and I go left or right accordingly. What + + + align:start position:0% +and I go left or right accordingly. What +would be bad about augmenting with rank + + align:start position:0% +would be bad about augmenting with rank + + + align:start position:0% +would be bad about augmenting with rank +of a node? + + align:start position:0% +of a node? + + + align:start position:0% +of a node? +Updates. Why? + + align:start position:0% + + + + align:start position:0% + +What's a bad example for an update? + + align:start position:0% +What's a bad example for an update? + + + align:start position:0% +What's a bad example for an update? +Yeah. + + align:start position:0% + + + + align:start position:0% + +Right. Say we insert a new minimum + + align:start position:0% +Right. Say we insert a new minimum + + + align:start position:0% +Right. Say we insert a new minimum +element. + + align:start position:0% + + + + align:start position:0% + +Ah, good catch, cameraman. + + align:start position:0% +Ah, good catch, cameraman. + + + align:start position:0% +Ah, good catch, cameraman. +That was for the camera, obviously. Um, + + align:start position:0% +That was for the camera, obviously. Um, + + + align:start position:0% +That was for the camera, obviously. Um, +so, right, if we insert, uh, this is off + + align:start position:0% +so, right, if we insert, uh, this is off + + + align:start position:0% +so, right, if we insert, uh, this is off +to the side, but say we insert, I'll + + align:start position:0% +to the side, but say we insert, I'll + + + align:start position:0% +to the side, but say we insert, I'll +call it minus infinity, a new key that + + align:start position:0% +call it minus infinity, a new key that + + + align:start position:0% +call it minus infinity, a new key that +is smaller than all other keys, then the + + align:start position:0% +is smaller than all other keys, then the + + + align:start position:0% +is smaller than all other keys, then the +rank of every node changes. + + align:start position:0% +rank of every node changes. + + + align:start position:0% +rank of every node changes. +So, uh, that's bad. + + align:start position:0% +So, uh, that's bad. + + + align:start position:0% +So, uh, that's bad. +U, it means that easy tree augmentation + + align:start position:0% +U, it means that easy tree augmentation + + + align:start position:0% +U, it means that easy tree augmentation +in particular isn't going to apply. And + + align:start position:0% +in particular isn't going to apply. And + + + align:start position:0% +in particular isn't going to apply. And +furthermore, it would take linear time + + align:start position:0% +furthermore, it would take linear time + + + align:start position:0% +furthermore, it would take linear time +to do this. And you could keep + + align:start position:0% +to do this. And you could keep + + + align:start position:0% +to do this. And you could keep +inserting. If you insert keys in + + align:start position:0% +inserting. If you insert keys in + + + align:start position:0% +inserting. If you insert keys in +decreasing order from there, every time + + align:start position:0% +decreasing order from there, every time + + + align:start position:0% +decreasing order from there, every time +you do an insert, all the ranks increase + + align:start position:0% +you do an insert, all the ranks increase + + + align:start position:0% +you do an insert, all the ranks increase +by one. Maintaining that's going to cost + + align:start position:0% +by one. Maintaining that's going to cost + + + align:start position:0% +by one. Maintaining that's going to cost +linear time per update. So you have to + + align:start position:0% +linear time per update. So you have to + + + align:start position:0% +linear time per update. So you have to +be really careful that uh the the + + align:start position:0% +be really careful that uh the the + + + align:start position:0% +be really careful that uh the the +function you you want to store actually + + align:start position:0% +function you you want to store actually + + + align:start position:0% +function you you want to store actually +can be maintained. Be very careful about + + align:start position:0% +can be maintained. Be very careful about + + + align:start position:0% +can be maintained. Be very careful about +that. Say on the quiz coming up uh that + + align:start position:0% +that. Say on the quiz coming up uh that + + + align:start position:0% +that. Say on the quiz coming up uh that +when you're augmenting something, you + + align:start position:0% +when you're augmenting something, you + + + align:start position:0% +when you're augmenting something, you +can actually maintain it. For example, + + align:start position:0% +can actually maintain it. For example, + + + align:start position:0% +can actually maintain it. For example, +it's very hard to maintain the depths of + + align:start position:0% +it's very hard to maintain the depths of + + + align:start position:0% +it's very hard to maintain the depths of +nodes because when you do a rotation, a + + align:start position:0% +nodes because when you do a rotation, a + + + align:start position:0% +nodes because when you do a rotation, a +whole lot of depths change. If your + + align:start position:0% +whole lot of depths change. If your + + + align:start position:0% +whole lot of depths change. If your +depth is counting from the root, how + + align:start position:0% +depth is counting from the root, how + + + align:start position:0% +depth is counting from the root, how +deep am I? Uh when I do a rotation, then + + align:start position:0% +deep am I? Uh when I do a rotation, then + + + align:start position:0% +deep am I? Uh when I do a rotation, then +this entire subree went down by one. + + align:start position:0% +this entire subree went down by one. + + + align:start position:0% +this entire subree went down by one. +This entire subree went up by one + + align:start position:0% +This entire subree went up by one + + + align:start position:0% +This entire subree went up by one +in this picture. Uh but it's very easy + + align:start position:0% +in this picture. Uh but it's very easy + + + align:start position:0% +in this picture. Uh but it's very easy +to maintain heights. For example, height + + align:start position:0% +to maintain heights. For example, height + + + align:start position:0% +to maintain heights. For example, height +counting from the bottom is okay because + + align:start position:0% +counting from the bottom is okay because + + + align:start position:0% +counting from the bottom is okay because +I don't affect the height of A, B, and + + align:start position:0% +I don't affect the height of A, B, and + + + align:start position:0% +I don't affect the height of A, B, and +C. I affect it for X and Y but that's + + align:start position:0% +C. I affect it for X and Y but that's + + + align:start position:0% +C. I affect it for X and Y but that's +just two nodes that I can afford. Okay, + + align:start position:0% +just two nodes that I can afford. Okay, + + + align:start position:0% +just two nodes that I can afford. Okay, +so that's what you want to be careful of + + align:start position:0% +so that's what you want to be careful of + + + align:start position:0% +so that's what you want to be careful of +uh in the easy tree augmentation. + + align:start position:0% + + + + align:start position:0% + +So most of the time easy tree + + align:start position:0% +So most of the time easy tree + + + align:start position:0% +So most of the time easy tree +augmentation does the job. But uh in the + + align:start position:0% +augmentation does the job. But uh in the + + + align:start position:0% +augmentation does the job. But uh in the +remaining two examples I want to show + + align:start position:0% +remaining two examples I want to show + + + align:start position:0% +remaining two examples I want to show +you cooler examples of augmentation. + + align:start position:0% +you cooler examples of augmentation. + + + align:start position:0% +you cooler examples of augmentation. +These are things you probably wouldn't + + align:start position:0% +These are things you probably wouldn't + + + align:start position:0% +These are things you probably wouldn't +be expected to come up with on your own + + align:start position:0% +be expected to come up with on your own + + + align:start position:0% +be expected to come up with on your own +but they're cool. So and that let us do + + align:start position:0% +but they're cool. So and that let us do + + + align:start position:0% +but they're cool. So and that let us do +more sophisticated operations. + + align:start position:0% + + + + align:start position:0% + +So first one is uh called level linking + + align:start position:0% + + + + align:start position:0% + +and here we're going to do it in the + + align:start position:0% +and here we're going to do it in the + + + align:start position:0% +and here we're going to do it in the +context of two three trees + + align:start position:0% +context of two three trees + + + align:start position:0% +context of two three trees +partly for variety. Um + + align:start position:0% +partly for variety. Um + + + align:start position:0% +partly for variety. Um +so uh the idea of level linking is very + + align:start position:0% +so uh the idea of level linking is very + + + align:start position:0% +so uh the idea of level linking is very +simple. Let me draw a 23 tree. + + align:start position:0% + + + + align:start position:0% + +Not a very impressive 23 tree because I + + align:start position:0% +Not a very impressive 23 tree because I + + + align:start position:0% +Not a very impressive 23 tree because I +don't feel like drawing too much. Uh + + align:start position:0% +don't feel like drawing too much. Uh + + + align:start position:0% +don't feel like drawing too much. Uh +level linking is the idea of in addition + + align:start position:0% +level linking is the idea of in addition + + + align:start position:0% +level linking is the idea of in addition +to these child and parent pointers, + + align:start position:0% +to these child and parent pointers, + + + align:start position:0% +to these child and parent pointers, +we're going to add links on all the + + align:start position:0% +we're going to add links on all the + + + align:start position:0% +we're going to add links on all the +levels. + + align:start position:0% + + + + align:start position:0% + +Horizontal links you might call + + align:start position:0% + + + + align:start position:0% + +Okay, so that's nice. Uh, two questions. + + align:start position:0% +Okay, so that's nice. Uh, two questions. + + + align:start position:0% +Okay, so that's nice. Uh, two questions. +Can we do this? and what's it good for? + + align:start position:0% +Can we do this? and what's it good for? + + + align:start position:0% +Can we do this? and what's it good for? +So let's start with can we do this? Uh + + align:start position:0% +So let's start with can we do this? Uh + + + align:start position:0% +So let's start with can we do this? Uh +remember in two three trees all we have + + align:start position:0% +remember in two three trees all we have + + + align:start position:0% +remember in two three trees all we have +to think about are splits and merges. So + + align:start position:0% +to think about are splits and merges. So + + + align:start position:0% +to think about are splits and merges. So +in a split + + align:start position:0% +in a split + + + align:start position:0% +in a split +we have for a brief period let's say uh + + align:start position:0% +we have for a brief period let's say uh + + + align:start position:0% +we have for a brief period let's say uh +three keys four children that's too + + align:start position:0% +three keys four children that's too + + + align:start position:0% +three keys four children that's too +many. + + align:start position:0% +many. + + + align:start position:0% +many. +So, we change that to uh + + align:start position:0% +So, we change that to uh + + + align:start position:0% +So, we change that to uh +uh yeah, + + align:start position:0% +uh yeah, + + + align:start position:0% +uh yeah, +I'm going to change this in a moment, + + align:start position:0% +I'm going to change this in a moment, + + + align:start position:0% +I'm going to change this in a moment, +but for now, this is the split you know + + align:start position:0% +but for now, this is the split you know + + + align:start position:0% +but for now, this is the split you know +and love maybe at least know. And uh if + + align:start position:0% +and love maybe at least know. And uh if + + + align:start position:0% +and love maybe at least know. And uh if +we think about where the level link + + align:start position:0% +we think about where the level link + + + align:start position:0% +we think about where the level link +pointers are, we have one before. Uh and + + align:start position:0% +pointers are, we have one before. Uh and + + + align:start position:0% +pointers are, we have one before. Uh and +then we just need to distribute those + + align:start position:0% +then we just need to distribute those + + + align:start position:0% +then we just need to distribute those +pointers + + align:start position:0% +pointers + + + align:start position:0% +pointers +uh to the two resulting nodes. And then + + align:start position:0% +uh to the two resulting nodes. And then + + + align:start position:0% +uh to the two resulting nodes. And then +we have to create a new pointer between + + align:start position:0% +we have to create a new pointer between + + + align:start position:0% +we have to create a new pointer between +the nodes that we just created. This is + + align:start position:0% +the nodes that we just created. This is + + + align:start position:0% +the nodes that we just created. This is +of course easy to do. We're here. We're + + align:start position:0% +of course easy to do. We're here. We're + + + align:start position:0% +of course easy to do. We're here. We're +taking this node. We're splitting it in + + align:start position:0% +taking this node. We're splitting it in + + + align:start position:0% +taking this node. We're splitting it in +half. Uh so we have the nodes right in + + align:start position:0% +half. Uh so we have the nodes right in + + + align:start position:0% +half. Uh so we have the nodes right in +our hands. So just add pointers between + + align:start position:0% +our hands. So just add pointers between + + + align:start position:0% +our hands. So just add pointers between +them. And key thing is there's some node + + align:start position:0% +them. And key thing is there's some node + + + align:start position:0% +them. And key thing is there's some node +over here on the left. It used to point + + align:start position:0% +over here on the left. It used to point + + + align:start position:0% +over here on the left. It used to point +to this node. Now we have to change it + + align:start position:0% +to this node. Now we have to change it + + + align:start position:0% +to this node. Now we have to change it +to point to the left version, the left + + align:start position:0% +to point to the left version, the left + + + align:start position:0% +to point to the left version, the left +half of the node. And there's some node + + align:start position:0% +half of the node. And there's some node + + + align:start position:0% +half of the node. And there's some node +over on the right. We have to change it + + align:start position:0% +over on the right. We have to change it + + + align:start position:0% +over on the right. We have to change it +left pointer to point to uh this right + + align:start position:0% +left pointer to point to uh this right + + + align:start position:0% +left pointer to point to uh this right +half of the node. But that's it. + + align:start position:0% +half of the node. But that's it. + + + align:start position:0% +half of the node. But that's it. +Constant time. Okay. So this is this + + align:start position:0% +Constant time. Okay. So this is this + + + align:start position:0% +Constant time. Okay. So this is this +doesn't fall under the category of easy + + align:start position:0% +doesn't fall under the category of easy + + + align:start position:0% +doesn't fall under the category of easy +tree augmentation because this is not + + align:start position:0% +tree augmentation because this is not + + + align:start position:0% +tree augmentation because this is not +isolated to the subree. We're also + + align:start position:0% +isolated to the subree. We're also + + + align:start position:0% +isolated to the subree. We're also +dealing with its left and right sub + + align:start position:0% +dealing with its left and right sub + + + align:start position:0% +dealing with its left and right sub +trees. But still easy to do in constant + + align:start position:0% +trees. But still easy to do in constant + + + align:start position:0% +trees. But still easy to do in constant +time. + + align:start position:0% + + + + align:start position:0% + +uh merging nodes is going to be similar. + + align:start position:0% + + + + align:start position:0% + +Uh if we steal a node from our uh parent + + align:start position:0% +Uh if we steal a node from our uh parent + + + align:start position:0% +Uh if we steal a node from our uh parent +then or from our sibling, nothing + + align:start position:0% +then or from our sibling, nothing + + + align:start position:0% +then or from our sibling, nothing +happens in terms of level lengths. But + + align:start position:0% +happens in terms of level lengths. But + + + align:start position:0% +happens in terms of level lengths. But +if we have say an empty node and a node + + align:start position:0% +if we have say an empty node and a node + + + align:start position:0% +if we have say an empty node and a node +that cannot afford any stealing. So we + + align:start position:0% +that cannot afford any stealing. So we + + + align:start position:0% +that cannot afford any stealing. So we +have single child here two children and + + align:start position:0% +have single child here two children and + + + align:start position:0% +have single child here two children and +we merge it into + + align:start position:0% +we merge it into + + + align:start position:0% +we merge it into +uh + + align:start position:0% + + + + align:start position:0% + +we're taking something from our parent + + align:start position:0% +we're taking something from our parent + + + align:start position:0% +we're taking something from our parent +bringing it down and we have three + + align:start position:0% +bringing it down and we have three + + + align:start position:0% +bringing it down and we have three +children afterwards. Again we used to + + align:start position:0% +children afterwards. Again we used to + + + align:start position:0% +children afterwards. Again we used to +have these these uh level pointers. Now + + align:start position:0% +have these these uh level pointers. Now + + + align:start position:0% +have these these uh level pointers. Now +we just have these level pointers. It's + + align:start position:0% +we just have these level pointers. It's + + + align:start position:0% +we just have these level pointers. It's +easy to maintain. It's just a constant + + align:start position:0% +easy to maintain. It's just a constant + + + align:start position:0% +easy to maintain. It's just a constant +sized neighborhood. Because we have the + + align:start position:0% +sized neighborhood. Because we have the + + + align:start position:0% +sized neighborhood. Because we have the +level links, we can get to our left and + + align:start position:0% +level links, we can get to our left and + + + align:start position:0% +level links, we can get to our left and +right neighbors and change where the + + align:start position:0% +right neighbors and change where the + + + align:start position:0% +right neighbors and change where the +links point to. So easy to maintain in + + align:start position:0% +links point to. So easy to maintain in + + + align:start position:0% +links point to. So easy to maintain in +constant time. + + align:start position:0% + + + + align:start position:0% + +I'll call it constant overhead. Every + + align:start position:0% +I'll call it constant overhead. Every + + + align:start position:0% +I'll call it constant overhead. Every +time we do a splitter merge, we spend uh + + align:start position:0% +time we do a splitter merge, we spend uh + + + align:start position:0% +time we do a splitter merge, we spend uh +an additional constant time to do it. + + align:start position:0% +an additional constant time to do it. + + + align:start position:0% +an additional constant time to do it. +We're already spending constant time, so + + align:start position:0% +We're already spending constant time, so + + + align:start position:0% +We're already spending constant time, so +just changes everything by a constant + + align:start position:0% +just changes everything by a constant + + + align:start position:0% +just changes everything by a constant +factor. + + align:start position:0% +factor. + + + align:start position:0% +factor. +So far so good. Uh, + + align:start position:0% +So far so good. Uh, + + + align:start position:0% +So far so good. Uh, +now I'm going to have to tweak this data + + align:start position:0% +now I'm going to have to tweak this data + + + align:start position:0% +now I'm going to have to tweak this data +structure a little bit, but let me first + + align:start position:0% +structure a little bit, but let me first + + + align:start position:0% +structure a little bit, but let me first +tell you why. What am I trying to + + align:start position:0% +tell you why. What am I trying to + + + align:start position:0% +tell you why. What am I trying to +achieve with this data structure? + + align:start position:0% + + + + align:start position:0% + +What I'm trying to achieve is something + + align:start position:0% +What I'm trying to achieve is something + + + align:start position:0% +What I'm trying to achieve is something +called uh the finger search property + + align:start position:0% + + + + align:start position:0% + +this is uh so let's just think about the + + align:start position:0% +this is uh so let's just think about the + + + align:start position:0% +this is uh so let's just think about the +case where I'm doing uh a successful + + align:start position:0% +case where I'm doing uh a successful + + + align:start position:0% +case where I'm doing uh a successful +search. I'm searching for a key X and I + + align:start position:0% +search. I'm searching for a key X and I + + + align:start position:0% +search. I'm searching for a key X and I +find it in the data structure. I find it + + align:start position:0% +find it in the data structure. I find it + + + align:start position:0% +find it in the data structure. I find it +in the tree. Uh + + align:start position:0% +in the tree. Uh + + + align:start position:0% +in the tree. Uh +suppose I found one. I searched for X. I + + align:start position:0% +suppose I found one. I searched for X. I + + + align:start position:0% +suppose I found one. I searched for X. I +found it. And then I searched for + + align:start position:0% +found it. And then I searched for + + + align:start position:0% +found it. And then I searched for +another key Y. Actually, I think I'll do + + align:start position:0% +another key Y. Actually, I think I'll do + + + align:start position:0% +another key Y. Actually, I think I'll do +the reverse. I first I found Y. Now I'm + + align:start position:0% +the reverse. I first I found Y. Now I'm + + + align:start position:0% +the reverse. I first I found Y. Now I'm +searching for X. If X and Y are nearby + + align:start position:0% +searching for X. If X and Y are nearby + + + align:start position:0% +searching for X. If X and Y are nearby +in the tree, I want this to run + + align:start position:0% +in the tree, I want this to run + + + align:start position:0% +in the tree, I want this to run +especially fast. For example, if X is a + + align:start position:0% +especially fast. For example, if X is a + + + align:start position:0% +especially fast. For example, if X is a +successor of Y, I want this to take + + align:start position:0% +successor of Y, I want this to take + + + align:start position:0% +successor of Y, I want this to take +constant time. That would be nice. + + align:start position:0% +constant time. That would be nice. + + + align:start position:0% +constant time. That would be nice. +uh in the worst case x and y are very + + align:start position:0% +uh in the worst case x and y are very + + + align:start position:0% +uh in the worst case x and y are very +far away from me in the tree then I + + align:start position:0% +far away from me in the tree then I + + + align:start position:0% +far away from me in the tree then I +wanted to take login time. So how could + + align:start position:0% +wanted to take login time. So how could + + + align:start position:0% +wanted to take login time. So how could +I interpolate between uh constant time + + align:start position:0% +I interpolate between uh constant time + + + align:start position:0% +I interpolate between uh constant time +for finding the the successor and login + + align:start position:0% +for finding the the successor and login + + + align:start position:0% +for finding the the successor and login +time for finding the uh worstase search. + + align:start position:0% +time for finding the uh worstase search. + + + align:start position:0% +time for finding the uh worstase search. +So I'm going to call this search + + align:start position:0% +So I'm going to call this search + + + align:start position:0% +So I'm going to call this search +of X from Y. Meaning uh this is a little + + align:start position:0% +of X from Y. Meaning uh this is a little + + + align:start position:0% +of X from Y. Meaning uh this is a little +imprecise, but what I mean is when I + + align:start position:0% +imprecise, but what I mean is when I + + + align:start position:0% +imprecise, but what I mean is when I +call search, I tell it where I've + + align:start position:0% +call search, I tell it where I've + + + align:start position:0% +call search, I tell it where I've +already found Y. And here it is. Here's + + align:start position:0% +already found Y. And here it is. Here's + + + align:start position:0% +already found Y. And here it is. Here's +the node storing Y. And now I want to + + align:start position:0% +the node storing Y. And now I want to + + + align:start position:0% +the node storing Y. And now I want to +I'm given a key X and I want to find + + align:start position:0% +I'm given a key X and I want to find + + + align:start position:0% +I'm given a key X and I want to find +that key X given the node that stores + + align:start position:0% +that key X given the node that stores + + + align:start position:0% +that key X given the node that stores +key Y. So how long should this take? + + align:start position:0% +key Y. So how long should this take? + + + align:start position:0% +key Y. So how long should this take? +What would be a good way to interpolate + + align:start position:0% +What would be a good way to interpolate + + + align:start position:0% +What would be a good way to interpolate +between constant time at one extreme in + + align:start position:0% +between constant time at one extreme in + + + align:start position:0% +between constant time at one extreme in +the good case when x and y are basically + + align:start position:0% +the good case when x and y are basically + + + align:start position:0% +the good case when x and y are basically +neighbors in + + align:start position:0% +neighbors in + + + align:start position:0% +neighbors in +in the sorted order versus uh log n time + + align:start position:0% +in the sorted order versus uh log n time + + + align:start position:0% +in the sorted order versus uh log n time +in the worst case. + + align:start position:0% +in the worst case. + + + align:start position:0% +in the worst case. +Yeah, + + align:start position:0% +Yeah, + + + align:start position:0% +Yeah, +the distance along the graph + + align:start position:0% +the distance along the graph + + + align:start position:0% +the distance along the graph +distance along the graph that would be + + align:start position:0% +distance along the graph that would be + + + align:start position:0% +distance along the graph that would be +one reasonable definition. Um, so I me I + + align:start position:0% +one reasonable definition. Um, so I me I + + + align:start position:0% +one reasonable definition. Um, so I me I +have a tree which you can think of as a + + align:start position:0% +have a tree which you can think of as a + + + align:start position:0% +have a tree which you can think of as a +graph. Measure the shortest path length + + align:start position:0% +graph. Measure the shortest path length + + + align:start position:0% +graph. Measure the shortest path length +from X to Y or or we have a more + + align:start position:0% +from X to Y or or we have a more + + + align:start position:0% +from X to Y or or we have a more +sophisticated graph over here. Uh maybe + + align:start position:0% +sophisticated graph over here. Uh maybe + + + align:start position:0% +sophisticated graph over here. Uh maybe +that that length. The trouble with the + + align:start position:0% +that that length. The trouble with the + + + align:start position:0% +that that length. The trouble with the +distance in the graph that's a + + align:start position:0% +distance in the graph that's a + + + align:start position:0% +distance in the graph that's a +reasonable suggestion, but it's very + + align:start position:0% +reasonable suggestion, but it's very + + + align:start position:0% +reasonable suggestion, but it's very +data structure specific. If I use an AVL + + align:start position:0% +data structure specific. If I use an AVL + + + align:start position:0% +data structure specific. If I use an AVL +tree without level links, then the + + align:start position:0% +tree without level links, then the + + + align:start position:0% +tree without level links, then the +distance could be one thing. Whereas if + + align:start position:0% +distance could be one thing. Whereas if + + + align:start position:0% +distance could be one thing. Whereas if +I use a 23 tree, even without level + + align:start position:0% +I use a 23 tree, even without level + + + align:start position:0% +I use a 23 tree, even without level +lengths, it's going to be a different + + align:start position:0% +lengths, it's going to be a different + + + align:start position:0% +lengths, it's going to be a different +distance. If I use a 23 tree with level + + align:start position:0% +distance. If I use a 23 tree with level + + + align:start position:0% +distance. If I use a 23 tree with level +lengths, it's going to be yet another + + align:start position:0% +lengths, it's going to be yet another + + + align:start position:0% +lengths, it's going to be yet another +distance. So that's a little + + align:start position:0% +distance. So that's a little + + + align:start position:0% +distance. So that's a little +unsatisfying. Uh I want this to be an + + align:start position:0% +unsatisfying. Uh I want this to be an + + + align:start position:0% +unsatisfying. Uh I want this to be an +answer to a question. Uh I don't want to + + align:start position:0% +answer to a question. Uh I don't want to + + + align:start position:0% +answer to a question. Uh I don't want to +phrase the question in terms of that + + align:start position:0% +phrase the question in terms of that + + + align:start position:0% +phrase the question in terms of that +data structure. Yeah. + + align:start position:0% +data structure. Yeah. + + + align:start position:0% +data structure. Yeah. +Difference between ranks between X and + + align:start position:0% +Difference between ranks between X and + + + align:start position:0% +Difference between ranks between X and +Y. That's close. + + align:start position:0% + + + + align:start position:0% + +So, I'm going to look at rank of X and + + align:start position:0% +So, I'm going to look at rank of X and + + + align:start position:0% +So, I'm going to look at rank of X and +rank of Y. Let's say take the absolute + + align:start position:0% +rank of Y. Let's say take the absolute + + + align:start position:0% +rank of Y. Let's say take the absolute +difference. That's kind of how far away + + align:start position:0% +difference. That's kind of how far away + + + align:start position:0% +difference. That's kind of how far away +they are in sorted order. Do you want to + + align:start position:0% +they are in sorted order. Do you want to + + + align:start position:0% +they are in sorted order. Do you want to +add anything? + + align:start position:0% +add anything? + + + align:start position:0% +add anything? +Log. Yeah. + + align:start position:0% +Log. Yeah. + + + align:start position:0% +Log. Yeah. +Because uh in the worst case, the + + align:start position:0% +Because uh in the worst case, the + + + align:start position:0% +Because uh in the worst case, the +difference in ranks could be linear. So, + + align:start position:0% +difference in ranks could be linear. So, + + + align:start position:0% +difference in ranks could be linear. So, +uh I want to add a log out here to get + + align:start position:0% +uh I want to add a log out here to get + + + align:start position:0% +uh I want to add a log out here to get +log N in that worst case. + + align:start position:0% +log N in that worst case. + + + align:start position:0% +log N in that worst case. +add a big O for safety. That's how much + + align:start position:0% +add a big O for safety. That's how much + + + align:start position:0% +add a big O for safety. That's how much +time we want to achieve. So this would + + align:start position:0% +time we want to achieve. So this would + + + align:start position:0% +time we want to achieve. So this would +be the finger search property that you + + align:start position:0% +be the finger search property that you + + + align:start position:0% +be the finger search property that you +can solve this problem in this much + + align:start position:0% +can solve this problem in this much + + + align:start position:0% +can solve this problem in this much +time. So again difference in ranks is at + + align:start position:0% +time. So again difference in ranks is at + + + align:start position:0% +time. So again difference in ranks is at +most n. So this is at most log n. But if + + align:start position:0% +most n. So this is at most log n. But if + + + align:start position:0% +most n. So this is at most log n. But if +y is the successor of x, this will only + + align:start position:0% +y is the successor of x, this will only + + + align:start position:0% +y is the successor of x, this will only +be constant and this will be constant. + + align:start position:0% +be constant and this will be constant. + + + align:start position:0% +be constant and this will be constant. +So this is great if you're doing lots of + + align:start position:0% +So this is great if you're doing lots of + + + align:start position:0% +So this is great if you're doing lots of +searches and you're always you tend to + + align:start position:0% +searches and you're always you tend to + + + align:start position:0% +searches and you're always you tend to +search for things that are nearby but + + align:start position:0% +search for things that are nearby but + + + align:start position:0% +search for things that are nearby but +sometimes you search for things that are + + align:start position:0% +sometimes you search for things that are + + + align:start position:0% +sometimes you search for things that are +far away. This gives you a nice nice + + align:start position:0% +far away. This gives you a nice nice + + + align:start position:0% +far away. This gives you a nice nice +bound. Uh + + align:start position:0% +bound. Uh + + + align:start position:0% +bound. Uh +so um on the one hand we have this is + + align:start position:0% +so um on the one hand we have this is + + + align:start position:0% +so um on the one hand we have this is +our goal log difference of ranks. On the + + align:start position:0% +our goal log difference of ranks. On the + + + align:start position:0% +our goal log difference of ranks. On the +other hand we have the suggestion that + + align:start position:0% +other hand we have the suggestion that + + + align:start position:0% +other hand we have the suggestion that +what we can achieve is something like + + align:start position:0% +what we can achieve is something like + + + align:start position:0% +what we can achieve is something like +the distance in the graph. + + align:start position:0% +the distance in the graph. + + + align:start position:0% +the distance in the graph. +Uh but we have a problem with this. I + + align:start position:0% +Uh but we have a problem with this. I + + + align:start position:0% +Uh but we have a problem with this. I +used to think that data structure solved + + align:start position:0% +used to think that data structure solved + + + align:start position:0% +used to think that data structure solved +this problem but it doesn't. Um so + + align:start position:0% + + + + align:start position:0% + +let me just draw actually I have a tree + + align:start position:0% +let me just draw actually I have a tree + + + align:start position:0% +let me just draw actually I have a tree +right there and I use that one. + + align:start position:0% + + + + align:start position:0% + +Suppose uh x is here and y is here. + + align:start position:0% +Suppose uh x is here and y is here. + + + align:start position:0% +Suppose uh x is here and y is here. +Okay, this is a bit of a small tree, but + + align:start position:0% +Okay, this is a bit of a small tree, but + + + align:start position:0% +Okay, this is a bit of a small tree, but +if you think about it long enough, uh + + align:start position:0% +if you think about it long enough, uh + + + align:start position:0% +if you think about it long enough, uh +this node is the predecessor of this + + align:start position:0% +this node is the predecessor of this + + + align:start position:0% +this node is the predecessor of this +node. So their difference in rank should + + align:start position:0% +node. So their difference in rank should + + + align:start position:0% +node. So their difference in rank should +be one. + + align:start position:0% + + + + align:start position:0% + +But the the distance in the graph here + + align:start position:0% +But the the distance in the graph here + + + align:start position:0% +But the the distance in the graph here +is two. Okay, not very impressive. But + + align:start position:0% +is two. Okay, not very impressive. But + + + align:start position:0% +is two. Okay, not very impressive. But +in general, you have a tree of height + + align:start position:0% +in general, you have a tree of height + + + align:start position:0% +in general, you have a tree of height +log n. If you look at the root and the + + align:start position:0% +log n. If you look at the root and the + + + align:start position:0% +log n. If you look at the root and the +predecessor of the root, + + align:start position:0% +predecessor of the root, + + + align:start position:0% +predecessor of the root, +they will have a rank difference of one + + align:start position:0% +they will have a rank difference of one + + + align:start position:0% +they will have a rank difference of one +by definition of predecessor, but the + + align:start position:0% +by definition of predecessor, but the + + + align:start position:0% +by definition of predecessor, but the +graph distance will be log n. So that's + + align:start position:0% +graph distance will be log n. So that's + + + align:start position:0% +graph distance will be log n. So that's +bad news because if we're only following + + align:start position:0% +bad news because if we're only following + + + align:start position:0% +bad news because if we're only following +pointers, there's no way to get from + + align:start position:0% +pointers, there's no way to get from + + + align:start position:0% +pointers, there's no way to get from +here to there in constant time. So we're + + align:start position:0% +here to there in constant time. So we're + + + align:start position:0% +here to there in constant time. So we're +not quite there. + + align:start position:0% +not quite there. + + + align:start position:0% +not quite there. +Uh we're going to use a different + + align:start position:0% +Uh we're going to use a different + + + align:start position:0% +Uh we're going to use a different +another tweak on that data structure + + align:start position:0% +another tweak on that data structure + + + align:start position:0% +another tweak on that data structure +which is uh + + align:start position:0% +which is uh + + + align:start position:0% +which is uh +store the data in the leaves. + + align:start position:0% + + + + align:start position:0% + +I tried to find a data structure that + + align:start position:0% +I tried to find a data structure that + + + align:start position:0% +I tried to find a data structure that +didn't require this and still got finger + + align:start position:0% +didn't require this and still got finger + + + align:start position:0% +didn't require this and still got finger +search but as far as I know there is + + align:start position:0% +search but as far as I know there is + + + align:start position:0% +search but as far as I know there is +none no such data structure. So uh if if + + align:start position:0% +none no such data structure. So uh if if + + + align:start position:0% +none no such data structure. So uh if if +you've looked if you look at say + + align:start position:0% +you've looked if you look at say + + + align:start position:0% +you've looked if you look at say +Wikipedia about B trees you'll see + + align:start position:0% +Wikipedia about B trees you'll see + + + align:start position:0% +Wikipedia about B trees you'll see +there's a ton of variations of B trees B + + align:start position:0% +there's a ton of variations of B trees B + + + align:start position:0% +there's a ton of variations of B trees B +plus trees B star trees. This is one of + + align:start position:0% +plus trees B star trees. This is one of + + + align:start position:0% +plus trees B star trees. This is one of +those I think B+ trees. Um + + align:start position:0% +those I think B+ trees. Um + + + align:start position:0% +those I think B+ trees. Um +as you saw B trees are two three trees. + + align:start position:0% +as you saw B trees are two three trees. + + + align:start position:0% +as you saw B trees are two three trees. +Every node stored uh one or two keys + + align:start position:0% +Every node stored uh one or two keys + + + align:start position:0% +Every node stored uh one or two keys +and each key only existed in one spot. + + align:start position:0% +and each key only existed in one spot. + + + align:start position:0% +and each key only existed in one spot. +We're still only going to put each key + + align:start position:0% +We're still only going to put each key + + + align:start position:0% +We're still only going to put each key +in one spot kind of uh but it's only + + align:start position:0% +in one spot kind of uh but it's only + + + align:start position:0% +in one spot kind of uh but it's only +going to be the leaf spots. Okay, good + + align:start position:0% +going to be the leaf spots. Okay, good + + + align:start position:0% +going to be the leaf spots. Okay, good +news is most nodes are leaves, right? + + align:start position:0% +news is most nodes are leaves, right? + + + align:start position:0% +news is most nodes are leaves, right? +Constant fraction of the nodes are going + + align:start position:0% +Constant fraction of the nodes are going + + + align:start position:0% +Constant fraction of the nodes are going +to be leaves. So it doesn't change too + + align:start position:0% +to be leaves. So it doesn't change too + + + align:start position:0% +to be leaves. So it doesn't change too +much from an efficiency space efficiency + + align:start position:0% +much from an efficiency space efficiency + + + align:start position:0% +much from an efficiency space efficiency +standpoint if we just put data down here + + align:start position:0% +standpoint if we just put data down here + + + align:start position:0% +standpoint if we just put data down here +and don't put I'm not going to put any + + align:start position:0% +and don't put I'm not going to put any + + + align:start position:0% +and don't put I'm not going to put any +keys up here for now. + + align:start position:0% +keys up here for now. + + + align:start position:0% +keys up here for now. +Okay. Uh so this is a little weird. + + align:start position:0% +Okay. Uh so this is a little weird. + + + align:start position:0% +Okay. Uh so this is a little weird. +Let me draw an example of such a tree. + + align:start position:0% +Let me draw an example of such a tree. + + + align:start position:0% +Let me draw an example of such a tree. +So maybe we have two and five and seven + + align:start position:0% +So maybe we have two and five and seven + + + align:start position:0% +So maybe we have two and five and seven +and + + align:start position:0% +and + + + align:start position:0% +and +uh + + align:start position:0% +uh + + + align:start position:0% +uh +eight + + align:start position:0% +eight + + + align:start position:0% +eight +nine. Let's say uh + + align:start position:0% +nine. Let's say uh + + + align:start position:0% +nine. Let's say uh +let's put a one here. So I'm going to + + align:start position:0% +let's put a one here. So I'm going to + + + align:start position:0% +let's put a one here. So I'm going to +have a node here with three children, a + + align:start position:0% +have a node here with three children, a + + + align:start position:0% +have a node here with three children, a +node here with two children, and here's + + align:start position:0% +node here with two children, and here's + + + align:start position:0% +node here with two children, and here's +a node with two children. So I think + + align:start position:0% +a node with two children. So I think + + + align:start position:0% +a node with two children. So I think +this mimics this tree roughly. I got Oh + + align:start position:0% +this mimics this tree roughly. I got Oh + + + align:start position:0% +this mimics this tree roughly. I got Oh +no, I got it exactly right. So here I've + + align:start position:0% +no, I got it exactly right. So here I've + + + align:start position:0% +no, I got it exactly right. So here I've +taken this tree structure. I've redrawn + + align:start position:0% +taken this tree structure. I've redrawn + + + align:start position:0% +taken this tree structure. I've redrawn +it. There's now no keys in these nodes. + + align:start position:0% +it. There's now no keys in these nodes. + + + align:start position:0% +it. There's now no keys in these nodes. +But everything else is going to be the + + align:start position:0% +But everything else is going to be the + + + align:start position:0% +But everything else is going to be the +same. Every node is going to have zero + + align:start position:0% +same. Every node is going to have zero + + + align:start position:0% +same. Every node is going to have zero +children if it's a leaf or two or three + + align:start position:0% +children if it's a leaf or two or three + + + align:start position:0% +children if it's a leaf or two or three +children otherwise. Never have one child + + align:start position:0% +children otherwise. Never have one child + + + align:start position:0% +children otherwise. Never have one child +because then you wouldn't get + + align:start position:0% +because then you wouldn't get + + + align:start position:0% +because then you wouldn't get +logarithmic depth. All the leaves are + + align:start position:0% +logarithmic depth. All the leaves are + + + align:start position:0% +logarithmic depth. All the leaves are +going to be at the same depth. + + align:start position:0% +going to be at the same depth. + + + align:start position:0% +going to be at the same depth. +Uh + + align:start position:0% +Uh + + + align:start position:0% +Uh +and that's it. + + align:start position:0% +and that's it. + + + align:start position:0% +and that's it. +Okay, that is uh 23 tree with the data + + align:start position:0% +Okay, that is uh 23 tree with the data + + + align:start position:0% +Okay, that is uh 23 tree with the data +stored in the leaves. It's a useful + + align:start position:0% +stored in the leaves. It's a useful + + + align:start position:0% +stored in the leaves. It's a useful +trick to know. Uh now we're going to do + + align:start position:0% +trick to know. Uh now we're going to do + + + align:start position:0% +trick to know. Uh now we're going to do +a level linked 23 tree. So in addition + + align:start position:0% +a level linked 23 tree. So in addition + + + align:start position:0% +a level linked 23 tree. So in addition +to that picture, we're going to have + + align:start position:0% +to that picture, we're going to have + + + align:start position:0% +to that picture, we're going to have +links like this. + + align:start position:0% + + + + align:start position:0% + +Okay. And I should check that I can + + align:start position:0% +Okay. And I should check that I can + + + align:start position:0% +Okay. And I should check that I can +still do insert and delete into these + + align:start position:0% +still do insert and delete into these + + + align:start position:0% +still do insert and delete into these +structures. It's actually not too hard. + + align:start position:0% +structures. It's actually not too hard. + + + align:start position:0% +structures. It's actually not too hard. +Uh but let's think about it. + + align:start position:0% + + + + align:start position:0% + +Uh I think actually it might be easier. + + align:start position:0% +Uh I think actually it might be easier. + + + align:start position:0% +Uh I think actually it might be easier. +Let's let's see. Uh + + align:start position:0% +Let's let's see. Uh + + + align:start position:0% +Let's let's see. Uh +so if I want to do an insert + + align:start position:0% + + + + align:start position:0% + +uh okay I have to first search for where + + align:start position:0% +uh okay I have to first search for where + + + align:start position:0% +uh okay I have to first search for where +I'm inserting. Uh I haven't told you how + + align:start position:0% +I'm inserting. Uh I haven't told you how + + + align:start position:0% +I'm inserting. Uh I haven't told you how +to do search yet. Um okay so let's first + + align:start position:0% +to do search yet. Um okay so let's first + + + align:start position:0% +to do search yet. Um okay so let's first +think about search. + + align:start position:0% + + + + align:start position:0% + +What we're going to do is + + align:start position:0% +What we're going to do is + + + align:start position:0% +What we're going to do is +uh data structure augmentation. we have + + align:start position:0% +uh data structure augmentation. we have + + + align:start position:0% +uh data structure augmentation. we have +simple tree augmentation. Um, so I'm + + align:start position:0% +simple tree augmentation. Um, so I'm + + + align:start position:0% +simple tree augmentation. Um, so I'm +going to do it and at each node what the + + align:start position:0% +going to do it and at each node what the + + + align:start position:0% +going to do it and at each node what the +functions I'm going to store are the + + align:start position:0% +functions I'm going to store are the + + + align:start position:0% +functions I'm going to store are the +minimum key in the subree and the + + align:start position:0% +minimum key in the subree and the + + + align:start position:0% +minimum key in the subree and the +maximum key in the subree. + + align:start position:0% + + + + align:start position:0% + +There are there are many ways to do this + + align:start position:0% +There are there are many ways to do this + + + align:start position:0% +There are there are many ways to do this +but uh here I think this is kind of the + + align:start position:0% +but uh here I think this is kind of the + + + align:start position:0% +but uh here I think this is kind of the +simplest. + + align:start position:0% + + + + align:start position:0% + +So what that means is at this node I'm + + align:start position:0% +So what that means is at this node I'm + + + align:start position:0% +So what that means is at this node I'm +going to store one as the min and seven + + align:start position:0% +going to store one as the min and seven + + + align:start position:0% +going to store one as the min and seven +as the max. + + align:start position:0% +as the max. + + + align:start position:0% +as the max. +Uh and at this node it's going to be one + + align:start position:0% +Uh and at this node it's going to be one + + + align:start position:0% +Uh and at this node it's going to be one +at the min and nine at the max. And here + + align:start position:0% +at the min and nine at the max. And here + + + align:start position:0% +at the min and nine at the max. And here +we have eight is the min and nine as the + + align:start position:0% +we have eight is the min and nine as the + + + align:start position:0% +we have eight is the min and nine as the +max. Again, min and max of sub trees are + + align:start position:0% +max. Again, min and max of sub trees are + + + align:start position:0% +max. Again, min and max of sub trees are +easy to store. If I ever change a node, + + align:start position:0% +easy to store. If I ever change a node, + + + align:start position:0% +easy to store. If I ever change a node, +I can update it uh based on its children + + align:start position:0% +I can update it uh based on its children + + + align:start position:0% +I can update it uh based on its children +just by looking at the min of the + + align:start position:0% +just by looking at the min of the + + + align:start position:0% +just by looking at the min of the +leftmost child and the max of the + + align:start position:0% +leftmost child and the max of the + + + align:start position:0% +leftmost child and the max of the +rightmost child. Right? If I had to if I + + align:start position:0% +rightmost child. Right? If I had to if I + + + align:start position:0% +rightmost child. Right? If I had to if I +didn't know one and nine, I could just + + align:start position:0% +didn't know one and nine, I could just + + + align:start position:0% +didn't know one and nine, I could just +look at this min and that max and that's + + align:start position:0% +look at this min and that max and that's + + + align:start position:0% +look at this min and that max and that's +going to be the min and the max of the + + align:start position:0% +going to be the min and the max of the + + + align:start position:0% +going to be the min and the max of the +overall tree. So in constant time I can + + align:start position:0% +overall tree. So in constant time I can + + + align:start position:0% +overall tree. So in constant time I can +update the min and the max of a node + + align:start position:0% +update the min and the max of a node + + + align:start position:0% +update the min and the max of a node +given the min and the max of its + + align:start position:0% +given the min and the max of its + + + align:start position:0% +given the min and the max of its +children. Uh special case is at the + + align:start position:0% +children. Uh special case is at the + + + align:start position:0% +children. Uh special case is at the +leaves. Then you have to actually look + + align:start position:0% +leaves. Then you have to actually look + + + align:start position:0% +leaves. Then you have to actually look +at keys and compare them. But leaves + + align:start position:0% +at keys and compare them. But leaves + + + align:start position:0% +at keys and compare them. But leaves +only have at most two keys. So pretty + + align:start position:0% +only have at most two keys. So pretty + + + align:start position:0% +only have at most two keys. So pretty +easy to compare them. Uh constant time. + + align:start position:0% +easy to compare them. Uh constant time. + + + align:start position:0% +easy to compare them. Uh constant time. +Okay. So that's how I do the + + align:start position:0% +Okay. So that's how I do the + + + align:start position:0% +Okay. So that's how I do the +augmentation. Now how do I do a search? + + align:start position:0% +augmentation. Now how do I do a search? + + + align:start position:0% +augmentation. Now how do I do a search? +Well, if I'm at a node and I'm searching + + align:start position:0% +Well, if I'm at a node and I'm searching + + + align:start position:0% +Well, if I'm at a node and I'm searching +for a key uh well let's say I'm at this + + align:start position:0% +for a key uh well let's say I'm at this + + + align:start position:0% +for a key uh well let's say I'm at this +node. I'm searching for a key like uh + + align:start position:0% +node. I'm searching for a key like uh + + + align:start position:0% +node. I'm searching for a key like uh +eight. What I'm going to do is look at + + align:start position:0% +eight. What I'm going to do is look at + + + align:start position:0% +eight. What I'm going to do is look at +all of the children. In this case, + + align:start position:0% +all of the children. In this case, + + + align:start position:0% +all of the children. In this case, +there's two. In the worst case, there's + + align:start position:0% +there's two. In the worst case, there's + + + align:start position:0% +there's two. In the worst case, there's +three. I look at the min and max and I + + align:start position:0% +three. I look at the min and max and I + + + align:start position:0% +three. I look at the min and max and I +see where does eight fall. Well, it + + align:start position:0% +see where does eight fall. Well, it + + + align:start position:0% +see where does eight fall. Well, it +falls in this interval. If I was + + align:start position:0% +falls in this interval. If I was + + + align:start position:0% +falls in this interval. If I was +searching for seven and a half, I'd know + + align:start position:0% +searching for seven and a half, I'd know + + + align:start position:0% +searching for seven and a half, I'd know +it's not there. It's somewhere. It's + + align:start position:0% +it's not there. It's somewhere. It's + + + align:start position:0% +it's not there. It's somewhere. It's +going to be in between here. If I'm + + align:start position:0% +going to be in between here. If I'm + + + align:start position:0% +going to be in between here. If I'm +doing successor, uh then uh I'll go to + + align:start position:0% +doing successor, uh then uh I'll go to + + + align:start position:0% +doing successor, uh then uh I'll go to +the right. If I'm doing predecessor, + + align:start position:0% +the right. If I'm doing predecessor, + + + align:start position:0% +the right. If I'm doing predecessor, +I'll go to the left and then take the + + align:start position:0% +I'll go to the left and then take the + + + align:start position:0% +I'll go to the left and then take the +either the maximum item or the minimum + + align:start position:0% +either the maximum item or the minimum + + + align:start position:0% +either the maximum item or the minimum +item. If I'm searching for eight, I see, + + align:start position:0% +item. If I'm searching for eight, I see, + + + align:start position:0% +item. If I'm searching for eight, I see, +oh, eight falls in the interval between + + align:start position:0% +oh, eight falls in the interval between + + + align:start position:0% +oh, eight falls in the interval between +eight and nine. So, I should clearly + + align:start position:0% +eight and nine. So, I should clearly + + + align:start position:0% +eight and nine. So, I should clearly +take the right child among those two + + align:start position:0% +take the right child among those two + + + align:start position:0% +take the right child among those two +children. In general, there's three + + align:start position:0% +children. In general, there's three + + + align:start position:0% +children. In general, there's three +children, three intervals, constant + + align:start position:0% +children, three intervals, constant + + + align:start position:0% +children, three intervals, constant +time. I can find where my key falls in + + align:start position:0% +time. I can find where my key falls in + + + align:start position:0% +time. I can find where my key falls in +the interval. Okay, so search is going + + align:start position:0% +the interval. Okay, so search is going + + + align:start position:0% +the interval. Okay, so search is going +to take login time again, provided I + + align:start position:0% +to take login time again, provided I + + + align:start position:0% +to take login time again, provided I +have these mins and maxes. + + align:start position:0% +have these mins and maxes. + + + align:start position:0% +have these mins and maxes. +Okay, so it's it's you think stare at it + + align:start position:0% +Okay, so it's it's you think stare at it + + + align:start position:0% +Okay, so it's it's you think stare at it +long enough, this is pretty much the + + align:start position:0% +long enough, this is pretty much the + + + align:start position:0% +long enough, this is pretty much the +same thing as regular search in a 23 + + align:start position:0% +same thing as regular search in a 23 + + + align:start position:0% +same thing as regular search in a 23 +tree. Uh but I've put the data just one + + align:start position:0% +tree. Uh but I've put the data just one + + + align:start position:0% +tree. Uh but I've put the data just one +level down. + + align:start position:0% +level down. + + + align:start position:0% +level down. +Okay, + + align:start position:0% + + + + align:start position:0% + +good. That was regular search. Uh I + + align:start position:0% +good. That was regular search. Uh I + + + align:start position:0% +good. That was regular search. Uh I +still need to do finger search, but + + align:start position:0% +still need to do finger search, but + + + align:start position:0% +still need to do finger search, but +we'll get there. Uh now, if I want to do + + align:start position:0% +we'll get there. Uh now, if I want to do + + + align:start position:0% +we'll get there. Uh now, if I want to do +an insert into this data structure, + + align:start position:0% +an insert into this data structure, + + + align:start position:0% +an insert into this data structure, +uh what happens? Well, I search for the + + align:start position:0% +uh what happens? Well, I search for the + + + align:start position:0% +uh what happens? Well, I search for the +key. Let's say I'm inserting six. Uh so + + align:start position:0% +key. Let's say I'm inserting six. Uh so + + + align:start position:0% +key. Let's say I'm inserting six. Uh so +maybe I go here. I say oh six because + + align:start position:0% +maybe I go here. I say oh six because + + + align:start position:0% +maybe I go here. I say oh six because +six is in this interval. Uh six is in + + align:start position:0% +six is in this interval. Uh six is in + + + align:start position:0% +six is in this interval. Uh six is in +neither of these intervals. So uh but + + align:start position:0% +neither of these intervals. So uh but + + + align:start position:0% +neither of these intervals. So uh but +it's closest to the interval 25 or the + + align:start position:0% +it's closest to the interval 25 or the + + + align:start position:0% +it's closest to the interval 25 or the +interval 7. Let's say I go down to 25. + + align:start position:0% +interval 7. Let's say I go down to 25. + + + align:start position:0% +interval 7. Let's say I go down to 25. +And well to insert six I'll just add a + + align:start position:0% +And well to insert six I'll just add a + + + align:start position:0% +And well to insert six I'll just add a +six on there. Of course now that note is + + align:start position:0% +six on there. Of course now that note is + + + align:start position:0% +six on there. Of course now that note is +too big. So there's still going to be a + + align:start position:0% +too big. So there's still going to be a + + + align:start position:0% +too big. So there's still going to be a +split case at the leaves where I have uh + + align:start position:0% +split case at the leaves where I have uh + + + align:start position:0% +split case at the leaves where I have uh +let's say A B C too many keys. + + align:start position:0% +let's say A B C too many keys. + + + align:start position:0% +let's say A B C too many keys. +I'm going to split that into + + align:start position:0% +I'm going to split that into + + + align:start position:0% +I'm going to split that into +AB + + align:start position:0% +AB + + + align:start position:0% +AB +and C. This is different from before. It + + align:start position:0% +and C. This is different from before. It + + + align:start position:0% +and C. This is different from before. It +used to be I would promote B to the + + align:start position:0% +used to be I would promote B to the + + + align:start position:0% +used to be I would promote B to the +parent because the parent needed a key + + align:start position:0% +parent because the parent needed a key + + + align:start position:0% +parent because the parent needed a key +there. Now parents don't have keys. So + + align:start position:0% +there. Now parents don't have keys. So + + + align:start position:0% +there. Now parents don't have keys. So +I'm just going to split this thing + + align:start position:0% +I'm just going to split this thing + + + align:start position:0% +I'm just going to split this thing +roughly in half. + + align:start position:0% +roughly in half. + + + align:start position:0% +roughly in half. +It works. Uh it's still the case that + + align:start position:0% +It works. Uh it's still the case that + + + align:start position:0% +It works. Uh it's still the case that +whoever was the parent up here now has + + align:start position:0% +whoever was the parent up here now has + + + align:start position:0% +whoever was the parent up here now has +an additional child. One more child. So + + align:start position:0% +an additional child. One more child. So + + + align:start position:0% +an additional child. One more child. So +maybe that node now has four children, + + align:start position:0% +maybe that node now has four children, + + + align:start position:0% +maybe that node now has four children, +but it's supposed to be two or three. So + + align:start position:0% +but it's supposed to be two or three. So + + + align:start position:0% +but it's supposed to be two or three. So +if I have a node with four children, + + align:start position:0% +if I have a node with four children, + + + align:start position:0% +if I have a node with four children, +what I'm going to do supposed to use + + align:start position:0% +what I'm going to do supposed to use + + + align:start position:0% +what I'm going to do supposed to use +these fancy arrows. Uh what do I do in + + align:start position:0% +these fancy arrows. Uh what do I do in + + + align:start position:0% +these fancy arrows. Uh what do I do in +this case? I'm just going to split that + + align:start position:0% +this case? I'm just going to split that + + + align:start position:0% +this case? I'm just going to split that +into two nodes with two children. Okay. + + align:start position:0% +into two nodes with two children. Okay. + + + align:start position:0% +into two nodes with two children. Okay. +And again, this used to have a parent. + + align:start position:0% +And again, this used to have a parent. + + + align:start position:0% +And again, this used to have a parent. +Now that parent has an additional child, + + align:start position:0% +Now that parent has an additional child, + + + align:start position:0% +Now that parent has an additional child, +and that may cause another split. It's + + align:start position:0% +and that may cause another split. It's + + + align:start position:0% +and that may cause another split. It's +just like before. We'll just potentially + + align:start position:0% +just like before. We'll just potentially + + + align:start position:0% +just like before. We'll just potentially +split all the way up to the root. + + align:start position:0% +split all the way up to the root. + + + align:start position:0% +split all the way up to the root. +If we split the root, then we get an + + align:start position:0% +If we split the root, then we get an + + + align:start position:0% +If we split the root, then we get an +additional level. But uh we can do all + + align:start position:0% +additional level. But uh we can do all + + + align:start position:0% +additional level. But uh we can do all +this and we can still maintain our uh + + align:start position:0% +this and we can still maintain our uh + + + align:start position:0% +this and we can still maintain our uh +level links if we want, + + align:start position:0% + + + + align:start position:0% + +but everything will take login. I won't + + align:start position:0% +but everything will take login. I won't + + + align:start position:0% +but everything will take login. I won't +draw the delete case. It's uh delete is + + align:start position:0% +draw the delete case. It's uh delete is + + + align:start position:0% +draw the delete case. It's uh delete is +slightly more annoying, but I think in + + align:start position:0% +slightly more annoying, but I think in + + + align:start position:0% +slightly more annoying, but I think in +this case, you never have to worry about + + align:start position:0% +this case, you never have to worry about + + + align:start position:0% +this case, you never have to worry about +where's the key coming from. from your + + align:start position:0% +where's the key coming from. from your + + + align:start position:0% +where's the key coming from. from your +child or your your parent. You're just + + align:start position:0% +child or your your parent. You're just + + + align:start position:0% +child or your your parent. You're just +uh you're just merging nodes. So it's a + + align:start position:0% +uh you're just merging nodes. So it's a + + + align:start position:0% +uh you're just merging nodes. So it's a +little bit simpler, but you have to deal + + align:start position:0% +little bit simpler, but you have to deal + + + align:start position:0% +little bit simpler, but you have to deal +with the leaf case separately from the + + align:start position:0% +with the leaf case separately from the + + + align:start position:0% +with the leaf case separately from the +non-leaf case. Okay. So all this was to + + align:start position:0% +non-leaf case. Okay. So all this was to + + + align:start position:0% +non-leaf case. Okay. So all this was to +convince you that we can store data in + + align:start position:0% +convince you that we can store data in + + + align:start position:0% +convince you that we can store data in +the leaves. Two three trees still work + + align:start position:0% +the leaves. Two three trees still work + + + align:start position:0% +the leaves. Two three trees still work +fine. + + align:start position:0% +fine. + + + align:start position:0% +fine. +Now I claim that the graph distance in + + align:start position:0% +Now I claim that the graph distance in + + + align:start position:0% +Now I claim that the graph distance in +level link trees is within a constant + + align:start position:0% +level link trees is within a constant + + + align:start position:0% +level link trees is within a constant +factor of the finger search bound. So I + + align:start position:0% +factor of the finger search bound. So I + + + align:start position:0% +factor of the finger search bound. So I +claim I can get the finger search + + align:start position:0% +claim I can get the finger search + + + align:start position:0% +claim I can get the finger search +property in two three trees with data in + + align:start position:0% +property in two three trees with data in + + + align:start position:0% +property in two three trees with data in +the leaves with level links. Okay. So + + align:start position:0% +the leaves with level links. Okay. So + + + align:start position:0% +the leaves with level links. Okay. So +lots of changes here but in the end + + align:start position:0% +lots of changes here but in the end + + + align:start position:0% +lots of changes here but in the end +we're going to get a finger search + + align:start position:0% +we're going to get a finger search + + + align:start position:0% +we're going to get a finger search +bound. + + align:start position:0% +bound. + + + align:start position:0% +bound. +Let's go here. + + align:start position:0% + + + + align:start position:0% + +So, here's a finger search operation. Uh + + align:start position:0% +So, here's a finger search operation. Uh + + + align:start position:0% +So, here's a finger search operation. Uh +first thing I want to do is identify uh + + align:start position:0% +first thing I want to do is identify uh + + + align:start position:0% +first thing I want to do is identify uh +a node that I'm working with. I want to + + align:start position:0% +a node that I'm working with. I want to + + + align:start position:0% +a node that I'm working with. I want to +start from y's node. And we're so we're + + align:start position:0% +start from y's node. And we're so we're + + + align:start position:0% +start from y's node. And we're so we're +supposing that we're told the node a + + align:start position:0% +supposing that we're told the node a + + + align:start position:0% +supposing that we're told the node a +leaf uh that contains y. So I'm going to + + align:start position:0% +leaf uh that contains y. So I'm going to + + + align:start position:0% +leaf uh that contains y. So I'm going to +let uh v be that leaf. + + align:start position:0% + + + + align:start position:0% + +Okay? because we're supposing we've + + align:start position:0% +Okay? because we're supposing we've + + + align:start position:0% +Okay? because we're supposing we've +already found y and now all the data is + + align:start position:0% +already found y and now all the data is + + + align:start position:0% +already found y and now all the data is +in the leaf. So give me the leaf that + + align:start position:0% +in the leaf. So give me the leaf that + + + align:start position:0% +in the leaf. So give me the leaf that +contains y. + + align:start position:0% +contains y. + + + align:start position:0% +contains y. +So that should take constant time. + + align:start position:0% +So that should take constant time. + + + align:start position:0% +So that should take constant time. +That's just part of the input. + + align:start position:0% +That's just part of the input. + + + align:start position:0% +That's just part of the input. +Now I'm going to do a combination of + + align:start position:0% +Now I'm going to do a combination of + + + align:start position:0% +Now I'm going to do a combination of +going up and horizontal. + + align:start position:0% +going up and horizontal. + + + align:start position:0% +going up and horizontal. +So I'm starting at a leaf + + align:start position:0% +So I'm starting at a leaf + + + align:start position:0% +So I'm starting at a leaf +and uh the first thing I'm going to do + + align:start position:0% +and uh the first thing I'm going to do + + + align:start position:0% +and uh the first thing I'm going to do +is check does this + + align:start position:0% +is check does this + + + align:start position:0% +is check does this +leaf contain what I want. Does it + + align:start position:0% +leaf contain what I want. Does it + + + align:start position:0% +leaf contain what I want. Does it +contain the key I'm searching for which + + align:start position:0% +contain the key I'm searching for which + + + align:start position:0% +contain the key I'm searching for which +is x. So that's going to be the case at + + align:start position:0% +is x. So that's going to be the case at + + + align:start position:0% +is x. So that's going to be the case at +every node I store the min and the max. + + align:start position:0% +every node I store the min and the max. + + + align:start position:0% +every node I store the min and the max. +So if x happens to fall between the min + + align:start position:0% +So if x happens to fall between the min + + + align:start position:0% +So if x happens to fall between the min +and the max then I'm happy. + + align:start position:0% +and the max then I'm happy. + + + align:start position:0% +and the max then I'm happy. +Then I'm going to do uh a regular search + + align:start position:0% + + + + align:start position:0% + +uh in these subree. + + align:start position:0% +uh in these subree. + + + align:start position:0% +uh in these subree. +Okay, this seems weird in the case of a + + align:start position:0% +Okay, this seems weird in the case of a + + + align:start position:0% +Okay, this seems weird in the case of a +leaf. In the case of a leaf, this is + + align:start position:0% +leaf. In the case of a leaf, this is + + + align:start position:0% +leaf. In the case of a leaf, this is +just check the two keys that are there + + align:start position:0% +just check the two keys that are there + + + align:start position:0% +just check the two keys that are there +whe which one is x. Okay. But in + + align:start position:0% +whe which one is x. Okay. But in + + + align:start position:0% +whe which one is x. Okay. But in +general, uh I gave you this search + + align:start position:0% +general, uh I gave you this search + + + align:start position:0% +general, uh I gave you this search +algorithm which was uh if uh I decide + + align:start position:0% +algorithm which was uh if uh I decide + + + align:start position:0% +algorithm which was uh if uh I decide +which child to take according to the + + align:start position:0% +which child to take according to the + + + align:start position:0% +which child to take according to the +ranges, that's a downward search. So + + align:start position:0% +ranges, that's a downward search. So + + + align:start position:0% +ranges, that's a downward search. So +that's what I'm calling regular search + + align:start position:0% +that's what I'm calling regular search + + + align:start position:0% +that's what I'm calling regular search +here. Maybe downward would be a little + + align:start position:0% +here. Maybe downward would be a little + + + align:start position:0% +here. Maybe downward would be a little +better. + + align:start position:0% + + + + align:start position:0% + +This is the usual login time thing. Uh + + align:start position:0% +This is the usual login time thing. Uh + + + align:start position:0% +This is the usual login time thing. Uh +but we're going to claim a bet a bound + + align:start position:0% +but we're going to claim a bet a bound + + + align:start position:0% +but we're going to claim a bet a bound +better than login. If this is not the + + align:start position:0% +better than login. If this is not the + + + align:start position:0% +better than login. If this is not the +case, then I know X either falls before + + align:start position:0% +case, then I know X either falls before + + + align:start position:0% +case, then I know X either falls before +V do min or after V domax. + + align:start position:0% + + + + align:start position:0% + +So if X is less than V dot min, + + align:start position:0% +So if X is less than V dot min, + + + align:start position:0% +So if X is less than V dot min, +then I'm going to uh go left. V equals V + + align:start position:0% +then I'm going to uh go left. V equals V + + + align:start position:0% +then I'm going to uh go left. V equals V +dot uh I'll call it level left to be + + align:start position:0% +dot uh I'll call it level left to be + + + align:start position:0% +dot uh I'll call it level left to be +clear. + + align:start position:0% +clear. + + + align:start position:0% +clear. +You might say left is the left child, + + align:start position:0% +You might say left is the left child, + + + align:start position:0% +You might say left is the left child, +but there's no left child here, of + + align:start position:0% +but there's no left child here, of + + + align:start position:0% +but there's no left child here, of +course, but level left is clear. we take + + align:start position:0% +course, but level left is clear. we take + + + align:start position:0% +course, but level left is clear. we take +the horizontal left pointer uh and + + align:start position:0% +the horizontal left pointer uh and + + + align:start position:0% +the horizontal left pointer uh and +otherwise uh x is greater than v domax + + align:start position:0% +otherwise uh x is greater than v domax + + + align:start position:0% +otherwise uh x is greater than v domax +and in that case uh we'll go right that + + align:start position:0% +and in that case uh we'll go right that + + + align:start position:0% +and in that case uh we'll go right that +seems logical + + align:start position:0% + + + + align:start position:0% + +and in both cases we're going to uh go + + align:start position:0% +and in both cases we're going to uh go + + + align:start position:0% +and in both cases we're going to uh go +up + + align:start position:0% +up + + + align:start position:0% +up +x= x dot parent oops v= parent + + align:start position:0% +x= x dot parent oops v= parent + + + align:start position:0% +x= x dot parent oops v= parent +X is not changing here. X is a key we're + + align:start position:0% +X is not changing here. X is a key we're + + + align:start position:0% +X is not changing here. X is a key we're +searching for. V is the node. V for + + align:start position:0% +searching for. V is the node. V for + + + align:start position:0% +searching for. V is the node. V for +vertex. + + align:start position:0% +vertex. + + + align:start position:0% +vertex. +So we're always going to go up and then + + align:start position:0% +So we're always going to go up and then + + + align:start position:0% +So we're always going to go up and then +we're going to go either left or right. + + align:start position:0% +we're going to go either left or right. + + + align:start position:0% +we're going to go either left or right. +And we're going to keep doing that until + + align:start position:0% +And we're going to keep doing that until + + + align:start position:0% +And we're going to keep doing that until +we find a sub tree that contains X in + + align:start position:0% +we find a sub tree that contains X in + + + align:start position:0% +we find a sub tree that contains X in +terms of key range. Then we're going to + + align:start position:0% +terms of key range. Then we're going to + + + align:start position:0% +terms of key range. Then we're going to +stop this part and we're just going to + + align:start position:0% +stop this part and we're just going to + + + align:start position:0% +stop this part and we're just going to +do downward search. I should say uh + + align:start position:0% +do downward search. I should say uh + + + align:start position:0% +do downward search. I should say uh +return here or something. + + align:start position:0% +return here or something. + + + align:start position:0% +return here or something. +uh I'm going to do a downward search + + align:start position:0% +uh I'm going to do a downward search + + + align:start position:0% +uh I'm going to do a downward search +which was this regular algorithm and + + align:start position:0% +which was this regular algorithm and + + + align:start position:0% +which was this regular algorithm and +then whatever it finds that's what I + + align:start position:0% +then whatever it finds that's what I + + + align:start position:0% +then whatever it finds that's what I +return. + + align:start position:0% +return. + + + align:start position:0% +return. +Okay, I claim the algorithm should be + + align:start position:0% +Okay, I claim the algorithm should be + + + align:start position:0% +Okay, I claim the algorithm should be +clear. What's less clear is that it + + align:start position:0% +clear. What's less clear is that it + + + align:start position:0% +clear. What's less clear is that it +achieves the bound that we want. But I + + align:start position:0% +achieves the bound that we want. But I + + + align:start position:0% +achieves the bound that we want. But I +claim this will achieve the finger + + align:start position:0% +claim this will achieve the finger + + + align:start position:0% +claim this will achieve the finger +search property. + + align:start position:0% +search property. + + + align:start position:0% +search property. +Uh let me draw a picture of what this + + align:start position:0% +Uh let me draw a picture of what this + + + align:start position:0% +Uh let me draw a picture of what this +thing looks like + + align:start position:0% + + + + align:start position:0% + +kind of generically. + + align:start position:0% +kind of generically. + + + align:start position:0% +kind of generically. +on small examples, it's hard to see + + align:start position:0% +on small examples, it's hard to see + + + align:start position:0% +on small examples, it's hard to see +what's going on. So, I'm going to draw a + + align:start position:0% +what's going on. So, I'm going to draw a + + + align:start position:0% +what's going on. So, I'm going to draw a +piece of a large example. + + align:start position:0% +piece of a large example. + + + align:start position:0% +piece of a large example. +So, + + align:start position:0% +So, + + + align:start position:0% +So, +uh let's say we start here. This is + + align:start position:0% +uh let's say we start here. This is + + + align:start position:0% +uh let's say we start here. This is +where Y was. I'm searching for X. Let's + + align:start position:0% +where Y was. I'm searching for X. Let's + + + align:start position:0% +where Y was. I'm searching for X. Let's +suppose X is to the right just because + + align:start position:0% +suppose X is to the right just because + + + align:start position:0% +suppose X is to the right just because +otherwise I go to the other board. Um so + + align:start position:0% +otherwise I go to the other board. Um so + + + align:start position:0% +otherwise I go to the other board. Um so +X is to the right. I'll discover that + + align:start position:0% +X is to the right. I'll discover that + + + align:start position:0% +X is to the right. I'll discover that +the range, you know, with just this + + align:start position:0% +the range, you know, with just this + + + align:start position:0% +the range, you know, with just this +node, this node maybe contains one other + + align:start position:0% +node, this node maybe contains one other + + + align:start position:0% +node, this node maybe contains one other +key. I'll find that range is too uh + + align:start position:0% +key. I'll find that range is too uh + + + align:start position:0% +key. I'll find that range is too uh +small. So I'm going to go follow the + + align:start position:0% +small. So I'm going to go follow the + + + align:start position:0% +small. So I'm going to go follow the +level right pointer and I get to some + + align:start position:0% +level right pointer and I get to some + + + align:start position:0% +level right pointer and I get to some +other node. Then I'm going to go to the + + align:start position:0% +other node. Then I'm going to go to the + + + align:start position:0% +other node. Then I'm going to go to the +parent. Maybe the parent was the parent + + align:start position:0% +parent. Maybe the parent was the parent + + + align:start position:0% +parent. Maybe the parent was the parent +of those two ch children. So I'm going + + align:start position:0% +of those two ch children. So I'm going + + + align:start position:0% +of those two ch children. So I'm going +to draw it like that. Um maybe I find + + align:start position:0% +to draw it like that. Um maybe I find + + + align:start position:0% +to draw it like that. Um maybe I find +this range is still too too low. I need + + align:start position:0% +this range is still too too low. I need + + + align:start position:0% +this range is still too too low. I need +to go right to get to X. So I'm going to + + align:start position:0% +to go right to get to X. So I'm going to + + + align:start position:0% +to go right to get to X. So I'm going to +follow a level pointer to the right. Uh + + align:start position:0% +follow a level pointer to the right. Uh + + + align:start position:0% +follow a level pointer to the right. Uh +I find a new subree. U I'll go to its + + align:start position:0% +I find a new subree. U I'll go to its + + + align:start position:0% +I find a new subree. U I'll go to its +parent. uh maybe I find that this subree + + align:start position:0% +parent. uh maybe I find that this subree + + + align:start position:0% +parent. uh maybe I find that this subree +still the max is too small so I have to + + align:start position:0% +still the max is too small so I have to + + + align:start position:0% +still the max is too small so I have to +go to the right again and then I take + + align:start position:0% +go to the right again and then I take + + + align:start position:0% +go to the right again and then I take +the parent uh so this was an example of + + align:start position:0% +the parent uh so this was an example of + + + align:start position:0% +the parent uh so this was an example of +a rightward parent here's an example of + + align:start position:0% +a rightward parent here's an example of + + + align:start position:0% +a rightward parent here's an example of +a leftward parent this is maybe the + + align:start position:0% +a leftward parent this is maybe the + + + align:start position:0% +a leftward parent this is maybe the +parent of both of these two children uh + + align:start position:0% +parent of both of these two children uh + + + align:start position:0% +parent of both of these two children uh +then maybe this subree is still too + + align:start position:0% +then maybe this subree is still too + + + align:start position:0% +then maybe this subree is still too +small the max is still smaller than x so + + align:start position:0% +small the max is still smaller than x so + + + align:start position:0% +small the max is still smaller than x so +then I go right one more time + + align:start position:0% +then I go right one more time + + + align:start position:0% +then I go right one more time +uh then I follow the parent always + + align:start position:0% +uh then I follow the parent always + + + align:start position:0% +uh then I follow the parent always +alternating between right and parent + + align:start position:0% +alternating between right and parent + + + align:start position:0% +alternating between right and parent +until I find a node whose subree + + align:start position:0% +until I find a node whose subree + + + align:start position:0% +until I find a node whose subree +contains X. It might have actually X may + + align:start position:0% +contains X. It might have actually X may + + + align:start position:0% +contains X. It might have actually X may +be down here because I immediately went + + align:start position:0% +be down here because I immediately went + + + align:start position:0% +be down here because I immediately went +to the parent without checking whether I + + align:start position:0% +to the parent without checking whether I + + + align:start position:0% +to the parent without checking whether I +found where X is. But if I know that X + + align:start position:0% +found where X is. But if I know that X + + + align:start position:0% +found where X is. But if I know that X +is somewhere in here, then I will do a + + align:start position:0% +is somewhere in here, then I will do a + + + align:start position:0% +is somewhere in here, then I will do a +downward search. Uh it might go left and + + align:start position:0% +downward search. Uh it might go left and + + + align:start position:0% +downward search. Uh it might go left and +then down here or it might go right or + + align:start position:0% +then down here or it might go right or + + + align:start position:0% +then down here or it might go right or +there's actually plus potentially three + + align:start position:0% +there's actually plus potentially three + + + align:start position:0% +there's actually plus potentially three +children. one of these searches will + + align:start position:0% +children. one of these searches will + + + align:start position:0% +children. one of these searches will +find the key X that I'm looking for + + align:start position:0% +find the key X that I'm looking for + + + align:start position:0% +find the key X that I'm looking for +because uh I'm in the case where X is + + align:start position:0% +because uh I'm in the case where X is + + + align:start position:0% +because uh I'm in the case where X is +between V domin + + align:start position:0% + + + + align:start position:0% + +X doesn't exist but it's uh predecessor + + align:start position:0% +X doesn't exist but it's uh predecessor + + + align:start position:0% +X doesn't exist but it's uh predecessor +or successor is in there somewhere. uh + + align:start position:0% +or successor is in there somewhere. uh + + + align:start position:0% +or successor is in there somewhere. uh +and so one of these three sub trees will + + align:start position:0% +and so one of these three sub trees will + + + align:start position:0% +and so one of these three sub trees will +contain the x range and then I go follow + + align:start position:0% +contain the x range and then I go follow + + + align:start position:0% +contain the x range and then I go follow +that path and keep going down uh until I + + align:start position:0% +that path and keep going down uh until I + + + align:start position:0% +that path and keep going down uh until I +find x or its predecessor or successor. + + align:start position:0% +find x or its predecessor or successor. + + + align:start position:0% +find x or its predecessor or successor. +Once I find its predecessor, I can use a + + align:start position:0% +Once I find its predecessor, I can use a + + + align:start position:0% +Once I find its predecessor, I can use a +level right pointer to find its + + align:start position:0% +level right pointer to find its + + + align:start position:0% +level right pointer to find its +successor and so on. + + align:start position:0% +successor and so on. + + + align:start position:0% +successor and so on. +So that's kind of the general picture of + + align:start position:0% +So that's kind of the general picture of + + + align:start position:0% +So that's kind of the general picture of +what's going on. We keep going rightward + + align:start position:0% +what's going on. We keep going rightward + + + align:start position:0% +what's going on. We keep going rightward +and we keep going up. Now + + align:start position:0% +and we keep going up. Now + + + align:start position:0% +and we keep going up. Now +uh + + align:start position:0% +uh + + + align:start position:0% +uh +suppose we do k up steps. + + align:start position:0% +suppose we do k up steps. + + + align:start position:0% +suppose we do k up steps. +Let's look at this uh this last step + + align:start position:0% +Let's look at this uh this last step + + + align:start position:0% +Let's look at this uh this last step +here. Uh step k. + + align:start position:0% + + + + align:start position:0% + +How high am I in the tree? I started at + + align:start position:0% +How high am I in the tree? I started at + + + align:start position:0% +How high am I in the tree? I started at +the leaf level. Remember in a 23 tree + + align:start position:0% +the leaf level. Remember in a 23 tree + + + align:start position:0% +the leaf level. Remember in a 23 tree +all the leaves have the same level and I + + align:start position:0% +all the leaves have the same level and I + + + align:start position:0% +all the leaves have the same level and I +went up every step. Uh sorry. Uh I don't + + align:start position:0% +went up every step. Uh sorry. Uh I don't + + + align:start position:0% +went up every step. Uh sorry. Uh I don't +know what this is like the two-step + + align:start position:0% +know what this is like the two-step + + + align:start position:0% +know what this is like the two-step +dance uh where when I let's say every + + align:start position:0% +dance uh where when I let's say every + + + align:start position:0% +dance uh where when I let's say every +iteration of this loop I do one left or + + align:start position:0% +iteration of this loop I do one left or + + + align:start position:0% +iteration of this loop I do one left or +right step and then a parent step. So uh + + align:start position:0% +right step and then a parent step. So uh + + + align:start position:0% +right step and then a parent step. So uh +I should call this iteration K. I guess + + align:start position:0% +I should call this iteration K. I guess + + + align:start position:0% +I should call this iteration K. I guess +there's two K steps then + + align:start position:0% + + + + align:start position:0% + +to be clear. Uh so in iteration K that + + align:start position:0% +to be clear. Uh so in iteration K that + + + align:start position:0% +to be clear. Uh so in iteration K that +means I've gone up K times and I've gone + + align:start position:0% +means I've gone up K times and I've gone + + + align:start position:0% +means I've gone up K times and I've gone +either right or left K times. You can + + align:start position:0% +either right or left K times. You can + + + align:start position:0% +either right or left K times. You can +show if you start going right you'll + + align:start position:0% +show if you start going right you'll + + + align:start position:0% +show if you start going right you'll +keep going right. If you keep if you + + align:start position:0% +keep going right. If you keep if you + + + align:start position:0% +keep going right. If you keep if you +initially go left you'll keep going + + align:start position:0% +initially go left you'll keep going + + + align:start position:0% +initially go left you'll keep going +left. That doesn't matter too much. Um + + align:start position:0% +left. That doesn't matter too much. Um + + + align:start position:0% +left. That doesn't matter too much. Um +at iteration K I am at height K + + align:start position:0% + + + + align:start position:0% + +or K minus one or however you want to + + align:start position:0% +or K minus one or however you want to + + + align:start position:0% +or K minus one or however you want to +count. Okay but let's call it K. So when + + align:start position:0% +count. Okay but let's call it K. So when + + + align:start position:0% +count. Okay but let's call it K. So when +I do this right pointer here, + + align:start position:0% + + + + align:start position:0% + +I know that uh for example, I am + + align:start position:0% +I know that uh for example, I am + + + align:start position:0% +I know that uh for example, I am +skipping over + + align:start position:0% + + + + align:start position:0% + +all of these keys. All the keys down, + + align:start position:0% +all of these keys. All the keys down, + + + align:start position:0% +all of these keys. All the keys down, +the keys are in the leaves. So all these + + align:start position:0% +the keys are in the leaves. So all these + + + align:start position:0% +the keys are in the leaves. So all these +keys down here, I'm jumping over them. + + align:start position:0% +keys down here, I'm jumping over them. + + + align:start position:0% +keys down here, I'm jumping over them. +How many keys are down there? + + align:start position:0% +How many keys are down there? + + + align:start position:0% +How many keys are down there? +Can you tell me uh roughly how many keys + + align:start position:0% +Can you tell me uh roughly how many keys + + + align:start position:0% +Can you tell me uh roughly how many keys +I'm skipping over when I'm moving right + + align:start position:0% +I'm skipping over when I'm moving right + + + align:start position:0% +I'm skipping over when I'm moving right +at height K? + + align:start position:0% + + + + align:start position:0% + +It's not a unique answer, but you can + + align:start position:0% +It's not a unique answer, but you can + + + align:start position:0% +It's not a unique answer, but you can +give me some bounds. + + align:start position:0% + + + + align:start position:0% + +Say again. It's like the number + + align:start position:0% +Say again. It's like the number + + + align:start position:0% +Say again. It's like the number +number of children to the k power. Yeah, + + align:start position:0% +number of children to the k power. Yeah, + + + align:start position:0% +number of children to the k power. Yeah, +except we don't know the number of + + align:start position:0% +except we don't know the number of + + + align:start position:0% +except we don't know the number of +children, but it's between two and + + align:start position:0% +children, but it's between two and + + + align:start position:0% +children, but it's between two and +three. Sorry, cluster one should be + + align:start position:0% +three. Sorry, cluster one should be + + + align:start position:0% +three. Sorry, cluster one should be +easy, but uh I fail. Um so it's between + + align:start position:0% +easy, but uh I fail. Um so it's between + + + align:start position:0% +easy, but uh I fail. Um so it's between +two and three children. So there's uh + + align:start position:0% +two and three children. So there's uh + + + align:start position:0% +two and three children. So there's uh +the number if you look at a uh a height + + align:start position:0% +the number if you look at a uh a height + + + align:start position:0% +the number if you look at a uh a height +k tree, + + align:start position:0% +k tree, + + + align:start position:0% +k tree, +how many leaves does it have? It's going + + align:start position:0% +how many leaves does it have? It's going + + + align:start position:0% +how many leaves does it have? It's going +to be between 2 to the k and 3 to the k. + + align:start position:0% +to be between 2 to the k and 3 to the k. + + + align:start position:0% +to be between 2 to the k and 3 to the k. +because I have between two and three + + align:start position:0% +because I have between two and three + + + align:start position:0% +because I have between two and three +children at every node. And so it's + + align:start position:0% +children at every node. And so it's + + + align:start position:0% +children at every node. And so it's +exponential in K. That's all I'll need. + + align:start position:0% +exponential in K. That's all I'll need. + + + align:start position:0% +exponential in K. That's all I'll need. +And so, okay, when I'm at height K here, + + align:start position:0% +And so, okay, when I'm at height K here, + + + align:start position:0% +And so, okay, when I'm at height K here, +I'm skipping over a height k minus one + + align:start position:0% +I'm skipping over a height k minus one + + + align:start position:0% +I'm skipping over a height k minus one +tree or something. uh but it's going to + + align:start position:0% +tree or something. uh but it's going to + + + align:start position:0% +tree or something. uh but it's going to +be + + align:start position:0% +be + + + align:start position:0% +be +so in iteration k I'm I'm skipping uh at + + align:start position:0% +so in iteration k I'm I'm skipping uh at + + + align:start position:0% +so in iteration k I'm I'm skipping uh at +least some constant times 2 to the k + + align:start position:0% +least some constant times 2 to the k + + + align:start position:0% +least some constant times 2 to the k +maybe 2 the k minus one or 2 the k minus + + align:start position:0% +maybe 2 the k minus one or 2 the k minus + + + align:start position:0% +maybe 2 the k minus one or 2 the k minus +2 I don't I'm being very sloppy it + + align:start position:0% +2 I don't I'm being very sloppy it + + + align:start position:0% +2 I don't I'm being very sloppy it +doesn't matter as long as it's + + align:start position:0% +doesn't matter as long as it's + + + align:start position:0% +doesn't matter as long as it's +exponential in k I'm happy because I'm + + align:start position:0% +exponential in k I'm happy because I'm + + + align:start position:0% +exponential in k I'm happy because I'm +supposing + + align:start position:0% +supposing + + + align:start position:0% +supposing +that x and y are somewhat close let's + + align:start position:0% +that x and y are somewhat close let's + + + align:start position:0% +that x and y are somewhat close let's +call this rank difference d + + align:start position:0% +call this rank difference d + + + align:start position:0% +call this rank difference d +then I claim the number of iterations + + align:start position:0% +then I claim the number of iterations + + + align:start position:0% +then I claim the number of iterations +I'll need to do in this loop is at most + + align:start position:0% +I'll need to do in this loop is at most + + + align:start position:0% +I'll need to do in this loop is at most +order log d + + align:start position:0% +order log d + + + align:start position:0% +order log d +because if uh when I get to the kth + + align:start position:0% +because if uh when I get to the kth + + + align:start position:0% +because if uh when I get to the kth +iteration I'm jumping over 2 to the k + + align:start position:0% +iteration I'm jumping over 2 to the k + + + align:start position:0% +iteration I'm jumping over 2 to the k +elements how how large does k have to be + + align:start position:0% +elements how how large does k have to be + + + align:start position:0% +elements how how large does k have to be +before 2 to the k is larger than uh d + + align:start position:0% +before 2 to the k is larger than uh d + + + align:start position:0% +before 2 to the k is larger than uh d +well log d + + align:start position:0% +well log d + + + align:start position:0% +well log d +log base 2 + + align:start position:0% + + + + align:start position:0% + +So uh the number of iterations + + align:start position:0% + + + + align:start position:0% + +is order log d + + align:start position:0% +is order log d + + + align:start position:0% +is order log d +where d is the rank difference. d is the + + align:start position:0% +where d is the rank difference. d is the + + + align:start position:0% +where d is the rank difference. d is the +absolute value between rank of x and + + align:start position:0% +absolute value between rank of x and + + + align:start position:0% +absolute value between rank of x and +rank of y. + + align:start position:0% + + + + align:start position:0% + +Okay, I'm being a little uh sloppy here. + + align:start position:0% +Okay, I'm being a little uh sloppy here. + + + align:start position:0% +Okay, I'm being a little uh sloppy here. +You probably want to use an induction. + + align:start position:0% +You probably want to use an induction. + + + align:start position:0% +You probably want to use an induction. +You need to show that they're really + + align:start position:0% +You need to show that they're really + + + align:start position:0% +You need to show that they're really +these items here that you're skipping + + align:start position:0% +these items here that you're skipping + + + align:start position:0% +these items here that you're skipping +over that are strictly between X and Y. + + align:start position:0% +over that are strictly between X and Y. + + + align:start position:0% +over that are strictly between X and Y. +But we know that there's only D items + + align:start position:0% +But we know that there's only D items + + + align:start position:0% +But we know that there's only D items +between X and Y. Actually, D minus one, + + align:start position:0% +between X and Y. Actually, D minus one, + + + align:start position:0% +between X and Y. Actually, D minus one, +I guess. So, uh as soon as we've skipped + + align:start position:0% +I guess. So, uh as soon as we've skipped + + + align:start position:0% +I guess. So, uh as soon as we've skipped +over all the items between X and Y, then + + align:start position:0% +over all the items between X and Y, then + + + align:start position:0% +over all the items between X and Y, then +we'll find a range that contains X and + + align:start position:0% +we'll find a range that contains X and + + + align:start position:0% +we'll find a range that contains X and +then we'll go do the downward search. + + align:start position:0% +then we'll go do the downward search. + + + align:start position:0% +then we'll go do the downward search. +Now, how long does the downward search + + align:start position:0% +Now, how long does the downward search + + + align:start position:0% +Now, how long does the downward search +cost? Whatever the height of the tree + + align:start position:0% +cost? Whatever the height of the tree + + + align:start position:0% +cost? Whatever the height of the tree +is. + + align:start position:0% +is. + + + align:start position:0% +is. +What's the height of the tree? That's + + align:start position:0% +What's the height of the tree? That's + + + align:start position:0% +What's the height of the tree? That's +the number of iterations. So, total + + align:start position:0% +the number of iterations. So, total + + + align:start position:0% +the number of iterations. So, total +cost, the downward search will cost the + + align:start position:0% +cost, the downward search will cost the + + + align:start position:0% +cost, the downward search will cost the +same as the rest of the search. + + align:start position:0% +same as the rest of the search. + + + align:start position:0% +same as the rest of the search. +And so, total cost is going to be order + + align:start position:0% +And so, total cost is going to be order + + + align:start position:0% +And so, total cost is going to be order +log d. + + align:start position:0% +log d. + + + align:start position:0% +log d. +Clear? + + align:start position:0% +Clear? + + + align:start position:0% +Clear? +Any questions about + + align:start position:0% +Any questions about + + + align:start position:0% +Any questions about +uh + + align:start position:0% +uh + + + align:start position:0% +uh +finger searching with level length data + + align:start position:0% +finger searching with level length data + + + align:start position:0% +finger searching with level length data +at the leaves? uh two three trees. Yeah. + + align:start position:0% +at the leaves? uh two three trees. Yeah. + + + align:start position:0% +at the leaves? uh two three trees. Yeah. +So I'm not sure what + + align:start position:0% +So I'm not sure what + + + align:start position:0% +So I'm not sure what +is + + align:start position:0% +is + + + align:start position:0% +is +I'm defining D to be the rank of X minus + + align:start position:0% +I'm defining D to be the rank of X minus + + + align:start position:0% +I'm defining D to be the rank of X minus +rank of Y. So then my goal is to achieve + + align:start position:0% +rank of Y. So then my goal is to achieve + + + align:start position:0% +rank of Y. So then my goal is to achieve +a log D bound and I'm claiming that + + align:start position:0% +a log D bound and I'm claiming that + + + align:start position:0% +a log D bound and I'm claiming that +because uh once I've skipped over D + + align:start position:0% +because uh once I've skipped over D + + + align:start position:0% +because uh once I've skipped over D +items then I'm done. Then I found X and + + align:start position:0% +items then I'm done. Then I found X and + + + align:start position:0% +items then I'm done. Then I found X and +that and in at step K I'm skipping over + + align:start position:0% +that and in at step K I'm skipping over + + + align:start position:0% +that and in at step K I'm skipping over +to the K items. So how big is K going to + + align:start position:0% +to the K items. So how big is K going to + + + align:start position:0% +to the K items. So how big is K going to +be? Log D. That's all. + + align:start position:0% +be? Log D. That's all. + + + align:start position:0% +be? Log D. That's all. +Yeah, that was just not I use D for + + align:start position:0% +Yeah, that was just not I use D for + + + align:start position:0% +Yeah, that was just not I use D for +notation here. + + align:start position:0% + + + + align:start position:0% + +Cool. So, uh + + align:start position:0% +Cool. So, uh + + + align:start position:0% +Cool. So, uh +finger searching it's nice especially if + + align:start position:0% +finger searching it's nice especially if + + + align:start position:0% +finger searching it's nice especially if +you're doing many consecutive searches + + align:start position:0% +you're doing many consecutive searches + + + align:start position:0% +you're doing many consecutive searches +that are all relatively close to each + + align:start position:0% +that are all relatively close to each + + + align:start position:0% +that are all relatively close to each +other. Uh + + align:start position:0% +other. Uh + + + align:start position:0% +other. Uh +but that was easy. Let's do a more + + align:start position:0% +but that was easy. Let's do a more + + + align:start position:0% +but that was easy. Let's do a more +difficult augmentation. Right. + + align:start position:0% +difficult augmentation. Right. + + + align:start position:0% +difficult augmentation. Right. +Uh so the last topic + + align:start position:0% +Uh so the last topic + + + align:start position:0% +Uh so the last topic +for today is range trees. This is + + align:start position:0% +for today is range trees. This is + + + align:start position:0% +for today is range trees. This is +probably the coolest example of + + align:start position:0% +probably the coolest example of + + + align:start position:0% +probably the coolest example of +augmentation at least that you'll see in + + align:start position:0% +augmentation at least that you'll see in + + + align:start position:0% +augmentation at least that you'll see in +this class. If you want to see more, you + + align:start position:0% +this class. If you want to see more, you + + + align:start position:0% +this class. If you want to see more, you +should take advanced data structure + + align:start position:0% +should take advanced data structure + + + align:start position:0% +should take advanced data structure +6851. + + align:start position:0% +6851. + + + align:start position:0% +6851. +Uh, + + align:start position:0% + + + + align:start position:0% + +and range trees solve a problem called + + align:start position:0% +and range trees solve a problem called + + + align:start position:0% +and range trees solve a problem called +orthogonal range searching. + + align:start position:0% +orthogonal range searching. + + + align:start position:0% +orthogonal range searching. +Not orthogonal search ranging. Uh, + + align:start position:0% +Not orthogonal search ranging. Uh, + + + align:start position:0% +Not orthogonal search ranging. Uh, +orthogonal + + align:start position:0% +orthogonal + + + align:start position:0% +orthogonal +range + + align:start position:0% +range + + + align:start position:0% +range +search. + + align:start position:0% + + + + align:start position:0% + +So, uh, what's the problem? I'm going to + + align:start position:0% +So, uh, what's the problem? I'm going to + + + align:start position:0% +So, uh, what's the problem? I'm going to +give you a bunch of points. + + align:start position:0% +give you a bunch of points. + + + align:start position:0% +give you a bunch of points. +Draw them as fat dots so you can + + align:start position:0% +Draw them as fat dots so you can + + + align:start position:0% +Draw them as fat dots so you can +actually see them. Uh, in some + + align:start position:0% +actually see them. Uh, in some + + + align:start position:0% +actually see them. Uh, in some +dimension. So, here's this is, for + + align:start position:0% +dimension. So, here's this is, for + + + align:start position:0% +dimension. So, here's this is, for +example, a 2D point set. + + align:start position:0% +example, a 2D point set. + + + align:start position:0% +example, a 2D point set. +Okay. Over here, I will draw a 3D point + + align:start position:0% +Okay. Over here, I will draw a 3D point + + + align:start position:0% +Okay. Over here, I will draw a 3D point +set. You can tell the difference, I'm + + align:start position:0% +set. You can tell the difference, I'm + + + align:start position:0% +set. You can tell the difference, I'm +sure. + + align:start position:0% + + + + align:start position:0% + +there. Now it's a 3D point set. Uh, and + + align:start position:0% +there. Now it's a 3D point set. Uh, and + + + align:start position:0% +there. Now it's a 3D point set. Uh, and +this is a static point set. You could + + align:start position:0% +this is a static point set. You could + + + align:start position:0% +this is a static point set. You could +make this dynamic, but let's just think + + align:start position:0% +make this dynamic, but let's just think + + + align:start position:0% +make this dynamic, but let's just think +about the static case. + + align:start position:0% +about the static case. + + + align:start position:0% +about the static case. +Uh, don't want the 2D points and the 3D + + align:start position:0% +Uh, don't want the 2D points and the 3D + + + align:start position:0% +Uh, don't want the 2D points and the 3D +points to mix. So, um, now you get to + + align:start position:0% +points to mix. So, um, now you get to + + + align:start position:0% +points to mix. So, um, now you get to +pre-process this into a data structure. + + align:start position:0% +pre-process this into a data structure. + + + align:start position:0% +pre-process this into a data structure. +So, it's a static data structure + + align:start position:0% +So, it's a static data structure + + + align:start position:0% +So, it's a static data structure +problem. And now I'm going to come along + + align:start position:0% +problem. And now I'm going to come along + + + align:start position:0% +problem. And now I'm going to come along +with a whole bunch of queries. A query + + align:start position:0% +with a whole bunch of queries. A query + + + align:start position:0% +with a whole bunch of queries. A query +will be a box. Okay. In two dimensions, + + align:start position:0% +will be a box. Okay. In two dimensions, + + + align:start position:0% +will be a box. Okay. In two dimensions, +a box is a rectangle + + align:start position:0% + + + + align:start position:0% + +something like this. Axis aligned. So I + + align:start position:0% +something like this. Axis aligned. So I + + + align:start position:0% +something like this. Axis aligned. So I +give you an x min, an xmaxx, a y min, + + align:start position:0% +give you an x min, an xmaxx, a y min, + + + align:start position:0% +give you an x min, an xmaxx, a y min, +and a yax. I want to know what are the + + align:start position:0% +and a yax. I want to know what are the + + + align:start position:0% +and a yax. I want to know what are the +points inside. Maybe I want you to list + + align:start position:0% +points inside. Maybe I want you to list + + + align:start position:0% +points inside. Maybe I want you to list +them. There's a lot of them. It's going + + align:start position:0% +them. There's a lot of them. It's going + + + align:start position:0% +them. There's a lot of them. It's going +to take a long time to list them. Maybe + + align:start position:0% +to take a long time to list them. Maybe + + + align:start position:0% +to take a long time to list them. Maybe +I just want to know 10 of them as + + align:start position:0% +I just want to know 10 of them as + + + align:start position:0% +I just want to know 10 of them as +examples. You know, maybe this is a + + align:start position:0% +examples. You know, maybe this is a + + + align:start position:0% +examples. You know, maybe this is a +Google search or something. I just get + + align:start position:0% +Google search or something. I just get + + + align:start position:0% +Google search or something. I just get +the first 10 results on the first page. + + align:start position:0% +the first 10 results on the first page. + + + align:start position:0% +the first 10 results on the first page. +I hit next, then I want the next 10. + + align:start position:0% +I hit next, then I want the next 10. + + + align:start position:0% +I hit next, then I want the next 10. +that kind of thing. Uh, or maybe I want + + align:start position:0% +that kind of thing. Uh, or maybe I want + + + align:start position:0% +that kind of thing. Uh, or maybe I want +to know how many search results there + + align:start position:0% +to know how many search results there + + + align:start position:0% +to know how many search results there +are, number of points in the rectangle, + + align:start position:0% +are, number of points in the rectangle, + + + align:start position:0% +are, number of points in the rectangle, +bunch of different problems. In 3D, it's + + align:start position:0% +bunch of different problems. In 3D, it's + + + align:start position:0% +bunch of different problems. In 3D, it's +a a 3D box, which is a little harder to + + align:start position:0% +a a 3D box, which is a little harder to + + + align:start position:0% +a a 3D box, which is a little harder to +draw, but or can't really tell which + + align:start position:0% +draw, but or can't really tell which + + + align:start position:0% +draw, but or can't really tell which +points are inside the box. Let's say + + align:start position:0% +points are inside the box. Let's say + + + align:start position:0% +points are inside the box. Let's say +these three points are all inside the + + align:start position:0% +these three points are all inside the + + + align:start position:0% +these three points are all inside the +box. I give you an interval in X, an + + align:start position:0% +box. I give you an interval in X, an + + + align:start position:0% +box. I give you an interval in X, an +interval in Y, and an interval in Z. And + + align:start position:0% +interval in Y, and an interval in Z. And + + + align:start position:0% +interval in Y, and an interval in Z. And +I want to know what are the points + + align:start position:0% +I want to know what are the points + + + align:start position:0% +I want to know what are the points +inside. Count how many are there? List + + align:start position:0% +inside. Count how many are there? List + + + align:start position:0% +inside. Count how many are there? List +them all. List 10 of them. Whatever. + + align:start position:0% +them all. List 10 of them. Whatever. + + + align:start position:0% +them all. List 10 of them. Whatever. +Okay. Uh + + align:start position:0% +Okay. Uh + + + align:start position:0% +Okay. Uh +I want to do this in poly log time. + + align:start position:0% +I want to do this in poly log time. + + + align:start position:0% +I want to do this in poly log time. +Let's say I'm going to do I'm going to + + align:start position:0% +Let's say I'm going to do I'm going to + + + align:start position:0% +Let's say I'm going to do I'm going to +achieve today log squared for the 2D + + align:start position:0% +achieve today log squared for the 2D + + + align:start position:0% +achieve today log squared for the 2D +problem and log cubed for the 3D problem + + align:start position:0% +problem and log cubed for the 3D problem + + + align:start position:0% +problem and log cubed for the 3D problem +plus whatever the size of the output is. + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +So let me just write that down. + + align:start position:0% + + + + align:start position:0% + +So the goal + + align:start position:0% +So the goal + + + align:start position:0% +So the goal +is to pre-process + + align:start position:0% + + + + align:start position:0% + +end points + + align:start position:0% +end points + + + align:start position:0% +end points +in dimensions. + + align:start position:0% +in dimensions. + + + align:start position:0% +in dimensions. +Uh so you get to spend a bunch of time + + align:start position:0% +Uh so you get to spend a bunch of time + + + align:start position:0% +Uh so you get to spend a bunch of time +pre-processing to support a query + + align:start position:0% +pre-processing to support a query + + + align:start position:0% +pre-processing to support a query +which is uh given a box + + align:start position:0% +which is uh given a box + + + align:start position:0% +which is uh given a box +axis aligned box uh find + + align:start position:0% +axis aligned box uh find + + + align:start position:0% +axis aligned box uh find +let's say the number of points + + align:start position:0% +let's say the number of points + + + align:start position:0% +let's say the number of points +in the box + + align:start position:0% +in the box + + + align:start position:0% +in the box +uh + + align:start position:0% +uh + + + align:start position:0% +uh +find k points in the box. + + align:start position:0% + + + + align:start position:0% + +I think that's good. That includes a + + align:start position:0% +I think that's good. That includes a + + + align:start position:0% +I think that's good. That includes a +special case of find all the points in + + align:start position:0% +special case of find all the points in + + + align:start position:0% +special case of find all the points in +the box. Uh so this of course we have to + + align:start position:0% +the box. Uh so this of course we have to + + + align:start position:0% +the box. Uh so this of course we have to +pay a penalty of order k for the output. + + align:start position:0% +pay a penalty of order k for the output. + + + align:start position:0% +pay a penalty of order k for the output. +Okay, no getting around that. Uh but I + + align:start position:0% +Okay, no getting around that. Uh but I + + + align:start position:0% +Okay, no getting around that. Uh but I +want the the rest of the time to be log + + align:start position:0% +want the the rest of the time to be log + + + align:start position:0% +want the the rest of the time to be log +to the d + + align:start position:0% + + + + align:start position:0% + +So we're going to achieve log to the dn + + align:start position:0% +So we're going to achieve log to the dn + + + align:start position:0% +So we're going to achieve log to the dn +plus size of the output + + align:start position:0% + + + + align:start position:0% + +and you get to control how big you want + + align:start position:0% +and you get to control how big you want + + + align:start position:0% +and you get to control how big you want +the output to be. So it's a pretty + + align:start position:0% +the output to be. So it's a pretty + + + align:start position:0% +the output to be. So it's a pretty +reasonable data structure in a certain + + align:start position:0% +reasonable data structure in a certain + + + align:start position:0% +reasonable data structure in a certain +sense. We will understand what the + + align:start position:0% +sense. We will understand what the + + + align:start position:0% +sense. We will understand what the +output is in log to the d time. If you + + align:start position:0% +output is in log to the d time. If you + + + align:start position:0% +output is in log to the d time. If you +actually want to list points well then + + align:start position:0% +actually want to list points well then + + + align:start position:0% +actually want to list points well then +you have to spend the time to do it. + + align:start position:0% +you have to spend the time to do it. + + + align:start position:0% +you have to spend the time to do it. +All right. So 2D and 3D are great but + + align:start position:0% +All right. So 2D and 3D are great but + + + align:start position:0% +All right. So 2D and 3D are great but +let's start with 1D first. We should + + align:start position:0% +let's start with 1D first. We should + + + align:start position:0% +let's start with 1D first. We should +understand 1D completely. Then we can + + align:start position:0% +understand 1D completely. Then we can + + + align:start position:0% +understand 1D completely. Then we can +generalize. + + align:start position:0% + + + + align:start position:0% + +1D we already know how to do. But + + align:start position:0% + + + + align:start position:0% + +1D I have a line. I have some points on + + align:start position:0% +1D I have a line. I have some points on + + + align:start position:0% +1D I have a line. I have some points on +the line. + + align:start position:0% + + + + align:start position:0% + +and I'm given as a query some interval + + align:start position:0% + + + + align:start position:0% + +and I want to know how many points are + + align:start position:0% +and I want to know how many points are + + + align:start position:0% +and I want to know how many points are +in the interval. Give me the points in + + align:start position:0% +in the interval. Give me the points in + + + align:start position:0% +in the interval. Give me the points in +the interval and so on. + + align:start position:0% +the interval and so on. + + + align:start position:0% +the interval and so on. +So how do I do this anyways? + + align:start position:0% + + + + align:start position:0% + +uh if d is one so I want to achieve log + + align:start position:0% +uh if d is one so I want to achieve log + + + align:start position:0% +uh if d is one so I want to achieve log +d sorry log n plus size of output + + align:start position:0% + + + + align:start position:0% + +I hear whispers + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +segment + + align:start position:0% +segment + + + align:start position:0% +segment +segment tree that's fancy we won't cover + + align:start position:0% +segment tree that's fancy we won't cover + + + align:start position:0% +segment tree that's fancy we won't cover +segment trees you probably probably + + align:start position:0% +segment trees you probably probably + + + align:start position:0% +segment trees you probably probably +segment tries do it but yeah we know + + align:start position:0% +segment tries do it but yeah we know + + + align:start position:0% +segment tries do it but yeah we know +lots of ways to do + + align:start position:0% + + + + align:start position:0% + +Yeah, + + align:start position:0% +Yeah, + + + align:start position:0% +Yeah, +sorted array is probably the simplest. + + align:start position:0% +sorted array is probably the simplest. + + + align:start position:0% +sorted array is probably the simplest. +If I store the items in a sorted array + + align:start position:0% +If I store the items in a sorted array + + + align:start position:0% +If I store the items in a sorted array +and I have two values here, I'll call + + align:start position:0% +and I have two values here, I'll call + + + align:start position:0% +and I have two values here, I'll call +them uh x1 and x2 because it's the like + + align:start position:0% +them uh x1 and x2 because it's the like + + + align:start position:0% +them uh x1 and x2 because it's the like +the x min and the xmaxx. Uh binary + + align:start position:0% +the x min and the xmaxx. Uh binary + + + align:start position:0% +the x min and the xmaxx. Uh binary +search for x1, binary search for x2, + + align:start position:0% +search for x1, binary search for x2, + + + align:start position:0% +search for x1, binary search for x2, +find the successor of x1 and the + + align:start position:0% +find the successor of x1 and the + + + align:start position:0% +find the successor of x1 and the +predecessor of x2. I'll find these two + + align:start position:0% +predecessor of x2. I'll find these two + + + align:start position:0% +predecessor of x2. I'll find these two +guys and then I know all the ones in + + align:start position:0% +guys and then I know all the ones in + + + align:start position:0% +guys and then I know all the ones in +between. That's the match. Okay, so + + align:start position:0% +between. That's the match. Okay, so + + + align:start position:0% +between. That's the match. Okay, so +that'll take login time to find those + + align:start position:0% +that'll take login time to find those + + + align:start position:0% +that'll take login time to find those +points and then we're good. + + align:start position:0% +points and then we're good. + + + align:start position:0% +points and then we're good. +Okay, so we could do a sorted array. Uh, + + align:start position:0% +Okay, so we could do a sorted array. Uh, + + + align:start position:0% +Okay, so we could do a sorted array. Uh, +of course sorted array is a little hard + + align:start position:0% +of course sorted array is a little hard + + + align:start position:0% +of course sorted array is a little hard +to generalize. Uh, I don't want to do a + + align:start position:0% +to generalize. Uh, I don't want to do a + + + align:start position:0% +to generalize. Uh, I don't want to do a +2D array. That sounds bad. Uh, you could + + align:start position:0% +2D array. That sounds bad. Uh, you could + + + align:start position:0% +2D array. That sounds bad. Uh, you could +of course do a binary search tree like + + align:start position:0% +of course do a binary search tree like + + + align:start position:0% +of course do a binary search tree like +an AVL tree. Same thing because we have + + align:start position:0% +an AVL tree. Same thing because we have + + + align:start position:0% +an AVL tree. Same thing because we have +login search find successor predecessor. + + align:start position:0% +login search find successor predecessor. + + + align:start position:0% +login search find successor predecessor. +I guess you could use van deoas but + + align:start position:0% +I guess you could use van deoas but + + + align:start position:0% +I guess you could use van deoas but +that's hard to generalize to 2D. Um, + + align:start position:0% +that's hard to generalize to 2D. Um, + + + align:start position:0% +that's hard to generalize to 2D. Um, +you could use level linked. Here's a + + align:start position:0% +you could use level linked. Here's a + + + align:start position:0% +you could use level linked. Here's a +fancy version. Uh, we could use level + + align:start position:0% +fancy version. Uh, we could use level + + + align:start position:0% +fancy version. Uh, we could use level +linked uh two three trees with data in + + align:start position:0% +linked uh two three trees with data in + + + align:start position:0% +linked uh two three trees with data in +the leaves. Then once I find xmin, I + + align:start position:0% +the leaves. Then once I find xmin, I + + + align:start position:0% +the leaves. Then once I find xmin, I +find this point I can go to the + + align:start position:0% +find this point I can go to the + + + align:start position:0% +find this point I can go to the +successor in constant time because + + align:start position:0% +successor in constant time because + + + align:start position:0% +successor in constant time because +that's a finger search with a rank + + align:start position:0% +that's a finger search with a rank + + + align:start position:0% +that's a finger search with a rank +difference of one. And I could just keep + + align:start position:0% +difference of one. And I could just keep + + + align:start position:0% +difference of one. And I could just keep +calling successor and in constant time + + align:start position:0% +calling successor and in constant time + + + align:start position:0% +calling successor and in constant time +per item, I will find the next item. So + + align:start position:0% +per item, I will find the next item. So + + + align:start position:0% +per item, I will find the next item. So +we could do that easily with the sorted + + align:start position:0% +we could do that easily with the sorted + + + align:start position:0% +we could do that easily with the sorted +array. BST is not so great if because + + align:start position:0% +array. BST is not so great if because + + + align:start position:0% +array. BST is not so great if because +successor might cost login each time. Uh + + align:start position:0% +successor might cost login each time. Uh + + + align:start position:0% +successor might cost login each time. Uh +but if I have the level lengths then + + align:start position:0% +but if I have the level lengths then + + + align:start position:0% +but if I have the level lengths then +basically I'm just walking down the link + + align:start position:0% +basically I'm just walking down the link + + + align:start position:0% +basically I'm just walking down the link +list at the bottom of the tree. Okay. So + + align:start position:0% +list at the bottom of the tree. Okay. So + + + align:start position:0% +list at the bottom of the tree. Okay. So +actually level + + align:start position:0% +actually level + + + align:start position:0% +actually level +is even better. + + align:start position:0% +is even better. + + + align:start position:0% +is even better. +Uh BST would achieve something like uh + + align:start position:0% +Uh BST would achieve something like uh + + + align:start position:0% +Uh BST would achieve something like uh +log n plus k log n where k is the size + + align:start position:0% +log n plus k log n where k is the size + + + align:start position:0% +log n plus k log n where k is the size +of the output. If there are k or if I + + align:start position:0% +of the output. If there are k or if I + + + align:start position:0% +of the output. If there are k or if I +want k points in the box, I have to pay + + align:start position:0% +want k points in the box, I have to pay + + + align:start position:0% +want k points in the box, I have to pay +log n for each level linked. I'll only + + align:start position:0% +log n for each level linked. I'll only + + + align:start position:0% +log n for each level linked. I'll only +pay log n plus k. + + align:start position:0% +pay log n plus k. + + + align:start position:0% +pay log n plus k. +Here I actually only need the levels at + + align:start position:0% +Here I actually only need the levels at + + + align:start position:0% +Here I actually only need the levels at +at the leaves, but the level lengths. + + align:start position:0% +at the leaves, but the level lengths. + + + align:start position:0% +at the leaves, but the level lengths. +Okay. All all good. But I actually want + + align:start position:0% +Okay. All all good. But I actually want + + + align:start position:0% +Okay. All all good. But I actually want +to tell you a different way to do it uh + + align:start position:0% +to tell you a different way to do it uh + + + align:start position:0% +to tell you a different way to do it uh +that will generalize better. + + align:start position:0% +that will generalize better. + + + align:start position:0% +that will generalize better. +So, + + align:start position:0% + + + + align:start position:0% + +the pictures are going to look just like + + align:start position:0% +the pictures are going to look just like + + + align:start position:0% +the pictures are going to look just like +the pictures we've talked about. + + align:start position:0% + + + + align:start position:0% + +So + + align:start position:0% + + + + align:start position:0% + +because I'm uh so this these would + + align:start position:0% +because I'm uh so this these would + + + align:start position:0% +because I'm uh so this these would +actually work dynamically. Uh my goal + + align:start position:0% +actually work dynamically. Uh my goal + + + align:start position:0% +actually work dynamically. Uh my goal +here is just to achieve a static data + + align:start position:0% +here is just to achieve a static data + + + align:start position:0% +here is just to achieve a static data +structure. I'm gonna idealize uh this + + align:start position:0% +structure. I'm gonna idealize uh this + + + align:start position:0% +structure. I'm gonna idealize uh this +solution a little bit + + align:start position:0% +solution a little bit + + + align:start position:0% +solution a little bit +and just say uh suppose I have a perfect + + align:start position:0% +and just say uh suppose I have a perfect + + + align:start position:0% +and just say uh suppose I have a perfect +perfectly balanced binary search tree. + + align:start position:0% +perfectly balanced binary search tree. + + + align:start position:0% +perfectly balanced binary search tree. +That's going to be my data structure. + + align:start position:0% +That's going to be my data structure. + + + align:start position:0% +That's going to be my data structure. +Okay, so the data structure is not hard. + + align:start position:0% +Okay, so the data structure is not hard. + + + align:start position:0% +Okay, so the data structure is not hard. +Uh but what's interesting is how I do a + + align:start position:0% +Uh but what's interesting is how I do a + + + align:start position:0% +Uh but what's interesting is how I do a +range search. + + align:start position:0% +range search. + + + align:start position:0% +range search. +So if I do + + align:start position:0% +So if I do + + + align:start position:0% +So if I do +a range query + + align:start position:0% + + + + align:start position:0% + +of the interval, I'll call it AB. + + align:start position:0% +of the interval, I'll call it AB. + + + align:start position:0% +of the interval, I'll call it AB. +Then what I'm just what I'm going to do + + align:start position:0% +Then what I'm just what I'm going to do + + + align:start position:0% +Then what I'm just what I'm going to do +is do a binary search for A. + + align:start position:0% +is do a binary search for A. + + + align:start position:0% +is do a binary search for A. +Do a binary search for B. + + align:start position:0% + + + + align:start position:0% + +Uh trim the common prefix + + align:start position:0% +Uh trim the common prefix + + + align:start position:0% +Uh trim the common prefix +of those search paths. + + align:start position:0% +of those search paths. + + + align:start position:0% +of those search paths. +That's basically finding the lowest + + align:start position:0% +That's basically finding the lowest + + + align:start position:0% +That's basically finding the lowest +common ancestor + + align:start position:0% +common ancestor + + + align:start position:0% +common ancestor +of those of A and B + + align:start position:0% + + + + align:start position:0% + +and then I'm going to do some stuff. Let + + align:start position:0% +and then I'm going to do some stuff. Let + + + align:start position:0% +and then I'm going to do some stuff. Let +me draw the picture. So here is suppose + + align:start position:0% +me draw the picture. So here is suppose + + + align:start position:0% +me draw the picture. So here is suppose +here's the node that contains A. Here's + + align:start position:0% +here's the node that contains A. Here's + + + align:start position:0% +here's the node that contains A. Here's +the node that contains B. They may not + + align:start position:0% +the node that contains B. They may not + + + align:start position:0% +the node that contains B. They may not +be at the same depth. Who knows? U then + + align:start position:0% +be at the same depth. Who knows? U then + + + align:start position:0% +be at the same depth. Who knows? U then +I'm going to look at the parents of A. I + + align:start position:0% +I'm going to look at the parents of A. I + + + align:start position:0% +I'm going to look at the parents of A. I +mean I just came down from some path + + align:start position:0% +mean I just came down from some path + + + align:start position:0% +mean I just came down from some path +here. and some path down to B. I want to + + align:start position:0% +here. and some path down to B. I want to + + + align:start position:0% +here. and some path down to B. I want to +find this branching point where the + + align:start position:0% +find this branching point where the + + + align:start position:0% +find this branching point where the +paths to A and the paths to B diverge. + + align:start position:0% + + + + align:start position:0% + +So, uh let's just look at the parent of + + align:start position:0% +So, uh let's just look at the parent of + + + align:start position:0% +So, uh let's just look at the parent of +A. It could be a right parent. + + align:start position:0% +A. It could be a right parent. + + + align:start position:0% +A. It could be a right parent. +Uh I guess draw that like that in which + + align:start position:0% +Uh I guess draw that like that in which + + + align:start position:0% +Uh I guess draw that like that in which +case there's a sub tree here. It could + + align:start position:0% +case there's a sub tree here. It could + + + align:start position:0% +case there's a sub tree here. It could +be a left parent case sub tree here. Uh + + align:start position:0% + + + + align:start position:0% + +I'm going to follow my convention again + + align:start position:0% +I'm going to follow my convention again + + + align:start position:0% +I'm going to follow my convention again +that X coordinate corresponds roughly to + + align:start position:0% +that X coordinate corresponds roughly to + + + align:start position:0% +that X coordinate corresponds roughly to +key. So maybe + + align:start position:0% +key. So maybe + + + align:start position:0% +key. So maybe +something like this. + + align:start position:0% +something like this. + + + align:start position:0% +something like this. +Left parent here. Maybe right parent + + align:start position:0% +Left parent here. Maybe right parent + + + align:start position:0% +Left parent here. Maybe right parent +here. + + align:start position:0% + + + + align:start position:0% + +Okay. something like that. + + align:start position:0% +Okay. something like that. + + + align:start position:0% +Okay. something like that. +Uh + + align:start position:0% + + + + align:start position:0% + +okay, remember it's a perfect tree. So + + align:start position:0% +okay, remember it's a perfect tree. So + + + align:start position:0% +okay, remember it's a perfect tree. So +actually all the leaves will be at the + + align:start position:0% +actually all the leaves will be at the + + + align:start position:0% +actually all the leaves will be at the +same level. + + align:start position:0% + + + + align:start position:0% + +And roughly here x coordinate + + align:start position:0% +And roughly here x coordinate + + + align:start position:0% +And roughly here x coordinate +corresponds to key. + + align:start position:0% +corresponds to key. + + + align:start position:0% +corresponds to key. +So here was a and I want to return all + + align:start position:0% +So here was a and I want to return all + + + align:start position:0% +So here was a and I want to return all +the keys that are between a and b. So + + align:start position:0% +the keys that are between a and b. So + + + align:start position:0% +the keys that are between a and b. So +that's everything in this sweep line. + + align:start position:0% + + + + align:start position:0% + +Okay. The parents of the LCA don't + + align:start position:0% +Okay. The parents of the LCA don't + + + align:start position:0% +Okay. The parents of the LCA don't +matter because this parent is either + + align:start position:0% +matter because this parent is either + + + align:start position:0% +matter because this parent is either +going to be way over to the right or way + + align:start position:0% +going to be way over to the right or way + + + align:start position:0% +going to be way over to the right or way +over to the left. In both cases, it's + + align:start position:0% +over to the left. In both cases, it's + + + align:start position:0% +over to the left. In both cases, it's +outside the interval A to B. So what + + align:start position:0% +outside the interval A to B. So what + + + align:start position:0% +outside the interval A to B. So what +I've tried to highlight here and I will + + align:start position:0% +I've tried to highlight here and I will + + + align:start position:0% +I've tried to highlight here and I will +color it in blue is + + align:start position:0% +color it in blue is + + + align:start position:0% +color it in blue is +the relevant nodes for the search + + align:start position:0% +the relevant nodes for the search + + + align:start position:0% +the relevant nodes for the search +between A and B. So A is between A and + + align:start position:0% +between A and B. So A is between A and + + + align:start position:0% +between A and B. So A is between A and +B. Uh this subree is greater than A and + + align:start position:0% +B. Uh this subree is greater than A and + + + align:start position:0% +B. Uh this subree is greater than A and +less than B. Uh this node and these + + align:start position:0% +less than B. Uh this node and these + + + align:start position:0% +less than B. Uh this node and these +nodes, this node and these nodes, + + align:start position:0% +nodes, this node and these nodes, + + + align:start position:0% +nodes, this node and these nodes, +this node and these nodes. + + align:start position:0% +this node and these nodes. + + + align:start position:0% +this node and these nodes. +uh the common ancestor and then the + + align:start position:0% +uh the common ancestor and then the + + + align:start position:0% +uh the common ancestor and then the +corresponding thing over here. + + align:start position:0% + + + + align:start position:0% + +Okay, all the nodes in all these blue + + align:start position:0% +Okay, all the nodes in all these blue + + + align:start position:0% +Okay, all the nodes in all these blue +sub trees plus these individual nodes + + align:start position:0% +sub trees plus these individual nodes + + + align:start position:0% +sub trees plus these individual nodes +fall in the interval between A and B. + + align:start position:0% +fall in the interval between A and B. + + + align:start position:0% +fall in the interval between A and B. +And that's it. + + align:start position:0% +And that's it. + + + align:start position:0% +And that's it. +Okay, this should look super familiar. + + align:start position:0% +Okay, this should look super familiar. + + + align:start position:0% +Okay, this should look super familiar. +It's just like when we were computing + + align:start position:0% +It's just like when we were computing + + + align:start position:0% +It's just like when we were computing +rank. We were trying to figure out how + + align:start position:0% +rank. We were trying to figure out how + + + align:start position:0% +rank. We were trying to figure out how +many guys are to our left or to our + + align:start position:0% +many guys are to our left or to our + + + align:start position:0% +many guys are to our left or to our +right. We're basically doing a rightward + + align:start position:0% +right. We're basically doing a rightward + + + align:start position:0% +right. We're basically doing a rightward +rank from A and a leftward rank from B. + + align:start position:0% +rank from A and a leftward rank from B. + + + align:start position:0% +rank from A and a leftward rank from B. +And that finds all the nodes and and + + align:start position:0% +And that finds all the nodes and and + + + align:start position:0% +And that finds all the nodes and and +stopping when those two searches + + align:start position:0% +stopping when those two searches + + + align:start position:0% +stopping when those two searches +converge. And then we're finding all the + + align:start position:0% +converge. And then we're finding all the + + + align:start position:0% +converge. And then we're finding all the +nodes between A and B. Okay, I'm not + + align:start position:0% +nodes between A and B. Okay, I'm not + + + align:start position:0% +nodes between A and B. Okay, I'm not +going to write down the pseudo code. + + align:start position:0% +going to write down the pseudo code. + + + align:start position:0% +going to write down the pseudo code. +Same kind of thing. You look at right + + align:start position:0% +Same kind of thing. You look at right + + + align:start position:0% +Same kind of thing. You look at right +parents and left parents. Whenever you + + align:start position:0% +parents and left parents. Whenever you + + + align:start position:0% +parents and left parents. Whenever you +you just walk up from A. Whenever you + + align:start position:0% +you just walk up from A. Whenever you + + + align:start position:0% +you just walk up from A. Whenever you +get a right parent, then you want that + + align:start position:0% +get a right parent, then you want that + + + align:start position:0% +get a right parent, then you want that +node and the subtree to its right. And + + align:start position:0% +node and the subtree to its right. And + + + align:start position:0% +node and the subtree to its right. And +so that will highlight these nodes. Same + + align:start position:0% +so that will highlight these nodes. Same + + + align:start position:0% +so that will highlight these nodes. Same +for B, but you look at left parents. And + + align:start position:0% +for B, but you look at left parents. And + + + align:start position:0% +for B, but you look at left parents. And +then you stop when those two searches + + align:start position:0% +then you stop when those two searches + + + align:start position:0% +then you stop when those two searches +converge. So you're going to do them in + + align:start position:0% +converge. So you're going to do them in + + + align:start position:0% +converge. So you're going to do them in +lock step. You do one step for A and B, + + align:start position:0% +lock step. You do one step for A and B, + + + align:start position:0% +lock step. You do one step for A and B, +one step for A and B, and when they + + align:start position:0% +one step for A and B, and when they + + + align:start position:0% +one step for A and B, and when they +happen to hit the same node, then you're + + align:start position:0% +happen to hit the same node, then you're + + + align:start position:0% +happen to hit the same node, then you're +done. You you add that node to your + + align:start position:0% +done. You you add that node to your + + + align:start position:0% +done. You you add that node to your +list. + + align:start position:0% +list. + + + align:start position:0% +list. +And what you end up with + + align:start position:0% +And what you end up with + + + align:start position:0% +And what you end up with +is a bunch of nodes + + align:start position:0% +is a bunch of nodes + + + align:start position:0% +is a bunch of nodes +and rooted sub trees. + + align:start position:0% + + + + align:start position:0% + +The things I circled in blue is going to + + align:start position:0% +The things I circled in blue is going to + + + align:start position:0% +The things I circled in blue is going to +be my return value. So I'm going to + + align:start position:0% +be my return value. So I'm going to + + + align:start position:0% +be my return value. So I'm going to +return all of these nodes explicitly and + + align:start position:0% +return all of these nodes explicitly and + + + align:start position:0% +return all of these nodes explicitly and +I'm also going to return these sub + + align:start position:0% +I'm also going to return these sub + + + align:start position:0% +I'm also going to return these sub +trees. I'm not going to have to write + + align:start position:0% +trees. I'm not going to have to write + + + align:start position:0% +trees. I'm not going to have to write +them down. I'm just going to return the + + align:start position:0% +them down. I'm just going to return the + + + align:start position:0% +them down. I'm just going to return the +root of the sub tree and say hey look + + align:start position:0% +root of the sub tree and say hey look + + + align:start position:0% +root of the sub tree and say hey look +here's an entire subree that contains + + align:start position:0% +here's an entire subree that contains + + + align:start position:0% +here's an entire subree that contains +nodes points that are in the answer. + + align:start position:0% +nodes points that are in the answer. + + + align:start position:0% +nodes points that are in the answer. +I don't have to list them explicitly. I + + align:start position:0% +I don't have to list them explicitly. I + + + align:start position:0% +I don't have to list them explicitly. I +can just give you the tree. Then if I + + align:start position:0% +can just give you the tree. Then if I + + + align:start position:0% +can just give you the tree. Then if I +want to know how many results are in the + + align:start position:0% +want to know how many results are in the + + + align:start position:0% +want to know how many results are in the +answer, well just augment to store + + align:start position:0% +answer, well just augment to store + + + align:start position:0% +answer, well just augment to store +subree size at at the beginning. Then I + + align:start position:0% +subree size at at the beginning. Then I + + + align:start position:0% +subree size at at the beginning. Then I +can count how many nodes are down here, + + align:start position:0% +can count how many nodes are down here, + + + align:start position:0% +can count how many nodes are down here, +how many nodes are down here. Add that + + align:start position:0% +how many nodes are down here. Add that + + + align:start position:0% +how many nodes are down here. Add that +up for all the triangles and then also + + align:start position:0% +up for all the triangles and then also + + + align:start position:0% +up for all the triangles and then also +add one for each of the blue nodes. And + + align:start position:0% +add one for each of the blue nodes. And + + + align:start position:0% +add one for each of the blue nodes. And +then I've counted the number uh the size + + align:start position:0% +then I've counted the number uh the size + + + align:start position:0% +then I've counted the number uh the size +of the answer in how much time how many + + align:start position:0% +of the answer in how much time how many + + + align:start position:0% +of the answer in how much time how many +sub trees and how many nodes am I + + align:start position:0% +sub trees and how many nodes am I + + + align:start position:0% +sub trees and how many nodes am I +returning here + + align:start position:0% +returning here + + + align:start position:0% +returning here +log + + align:start position:0% + + + + align:start position:0% + +log nodes and log n rooted sub trees + + align:start position:0% +log nodes and log n rooted sub trees + + + align:start position:0% +log nodes and log n rooted sub trees +because at each step I'm going up by one + + align:start position:0% +because at each step I'm going up by one + + + align:start position:0% +because at each step I'm going up by one +for a and up by one for b. So it's like + + align:start position:0% +for a and up by one for b. So it's like + + + align:start position:0% +for a and up by one for b. So it's like +two login. + + align:start position:0% + + + + align:start position:0% + +Cool. So I would call this an implicit + + align:start position:0% +Cool. So I would call this an implicit + + + align:start position:0% +Cool. So I would call this an implicit +representation of the answer. From that + + align:start position:0% +representation of the answer. From that + + + align:start position:0% +representation of the answer. From that +implicit representation, you can do uh + + align:start position:0% +implicit representation, you can do uh + + + align:start position:0% +implicit representation, you can do uh +subree size augmentation to count the + + align:start position:0% +subree size augmentation to count the + + + align:start position:0% +subree size augmentation to count the +size of the answer. You can just start + + align:start position:0% +size of the answer. You can just start + + + align:start position:0% +size of the answer. You can just start +walking through one by one. Uh do an in + + align:start position:0% +walking through one by one. Uh do an in + + + align:start position:0% +walking through one by one. Uh do an in +order traversal of the trees and you'll + + align:start position:0% +order traversal of the trees and you'll + + + align:start position:0% +order traversal of the trees and you'll +get the first k points in the answer in + + align:start position:0% +get the first k points in the answer in + + + align:start position:0% +get the first k points in the answer in +order K time question. + + align:start position:0% + + + + align:start position:0% + +That's right. As I'm walking up the + + align:start position:0% +That's right. As I'm walking up the + + + align:start position:0% +That's right. As I'm walking up the +tree, if it's a right parent, then I + + align:start position:0% +tree, if it's a right parent, then I + + + align:start position:0% +tree, if it's a right parent, then I +take the right sub tree and include that + + align:start position:0% +take the right sub tree and include that + + + align:start position:0% +take the right sub tree and include that +in the answer. If it's a left parent, + + align:start position:0% +in the answer. If it's a left parent, + + + align:start position:0% +in the answer. If it's a left parent, +just forget about it. Don't do anything. + + align:start position:0% +just forget about it. Don't do anything. + + + align:start position:0% +just forget about it. Don't do anything. +Just keep following parents. Whenever I + + align:start position:0% +Just keep following parents. Whenever I + + + align:start position:0% +Just keep following parents. Whenever I +do right parent, then I also add that + + align:start position:0% +do right parent, then I also add that + + + align:start position:0% +do right parent, then I also add that +node and the right sub tree. If it's a + + align:start position:0% +node and the right sub tree. If it's a + + + align:start position:0% +node and the right sub tree. If it's a +left parent, I don't include the node. I + + align:start position:0% +left parent, I don't include the node. I + + + align:start position:0% +left parent, I don't include the node. I +don't include the left subree. I also + + align:start position:0% +don't include the left subree. I also + + + align:start position:0% +don't include the left subree. I also +don't include the right sub tree. That + + align:start position:0% +don't include the right sub tree. That + + + align:start position:0% +don't include the right sub tree. That +would have too much stuff. Yep. + + align:start position:0% +would have too much stuff. Yep. + + + align:start position:0% +would have too much stuff. Yep. +It's easy when you see the picture. If + + align:start position:0% +It's easy when you see the picture. If + + + align:start position:0% +It's easy when you see the picture. If +we write down the algorithm, it's clear. + + align:start position:0% +we write down the algorithm, it's clear. + + + align:start position:0% +we write down the algorithm, it's clear. +It's left versus right uh parents. Yeah, + + align:start position:0% +It's left versus right uh parents. Yeah, + + + align:start position:0% +It's left versus right uh parents. Yeah, +would you include the left subree of B + + align:start position:0% +would you include the left subree of B + + + align:start position:0% +would you include the left subree of B +as well? + + align:start position:0% +as well? + + + align:start position:0% +as well? +I would also think you I should color + + align:start position:0% +I would also think you I should color + + + align:start position:0% +I would also think you I should color +the left subree of B. I didn't apply + + align:start position:0% +the left subree of B. I didn't apply + + + align:start position:0% +the left subree of B. I didn't apply +symmetry perfectly. So we have the right + + align:start position:0% +symmetry perfectly. So we have the right + + + align:start position:0% +symmetry perfectly. So we have the right +subree of A and the left subree of B. + + align:start position:0% +subree of A and the left subree of B. + + + align:start position:0% +subree of A and the left subree of B. +Thanks. Uh I would also include B + + align:start position:0% +Thanks. Uh I would also include B + + + align:start position:0% +Thanks. Uh I would also include B +if it's a closed interval. + + align:start position:0% +if it's a closed interval. + + + align:start position:0% +if it's a closed interval. +Okay, slightly more general. If A and B + + align:start position:0% +Okay, slightly more general. If A and B + + + align:start position:0% +Okay, slightly more general. If A and B +are not in the tree, then this is really + + align:start position:0% +are not in the tree, then this is really + + + align:start position:0% +are not in the tree, then this is really +the successor of A and this is the + + align:start position:0% +the successor of A and this is the + + + align:start position:0% +the successor of A and this is the +predecessor of B. Okay, so then A and B + + align:start position:0% +predecessor of B. Okay, so then A and B + + + align:start position:0% +predecessor of B. Okay, so then A and B +don't have to be in there. This is still + + align:start position:0% +don't have to be in there. This is still + + + align:start position:0% +don't have to be in there. This is still +a well- definfined range search. Okay, + + align:start position:0% +a well- definfined range search. Okay, + + + align:start position:0% +a well- definfined range search. Okay, +now we really understand 1D. I claim + + align:start position:0% +now we really understand 1D. I claim + + + align:start position:0% +now we really understand 1D. I claim +we're we've almost solved all + + align:start position:0% +we're we've almost solved all + + + align:start position:0% +we're we've almost solved all +dimensions. + + align:start position:0% +dimensions. + + + align:start position:0% +dimensions. +All we need is a little bit of + + align:start position:0% +All we need is a little bit of + + + align:start position:0% +All we need is a little bit of +augmentation. + + align:start position:0% +augmentation. + + + align:start position:0% +augmentation. +So, let's do it. + + align:start position:0% + + + + align:start position:0% + +Let's start with uh 2D but then 3D and + + align:start position:0% +Let's start with uh 2D but then 3D and + + + align:start position:0% +Let's start with uh 2D but then 3D and +4D and so on will be easy. + + align:start position:0% +4D and so on will be easy. + + + align:start position:0% +4D and so on will be easy. +Uh why do I care about 4D range trees? + + align:start position:0% +Uh why do I care about 4D range trees? + + + align:start position:0% +Uh why do I care about 4D range trees? +Because maybe I have a database. Each of + + align:start position:0% +Because maybe I have a database. Each of + + + align:start position:0% +Because maybe I have a database. Each of +these points is actually just a row in + + align:start position:0% +these points is actually just a row in + + + align:start position:0% +these points is actually just a row in +the database which has four columns, + + align:start position:0% +the database which has four columns, + + + align:start position:0% +the database which has four columns, +four values. And what I'm trying to do + + align:start position:0% +four values. And what I'm trying to do + + + align:start position:0% +four values. And what I'm trying to do +here is like find all the people in my + + align:start position:0% +here is like find all the people in my + + + align:start position:0% +here is like find all the people in my +database that have a salary between this + + align:start position:0% +database that have a salary between this + + + align:start position:0% +database that have a salary between this +and this and have an age between this + + align:start position:0% +and this and have an age between this + + + align:start position:0% +and this and have an age between this +and that and have a profession between + + align:start position:0% +and that and have a profession between + + + align:start position:0% +and that and have a profession between +this and this. I don't know what that + + align:start position:0% +this and this. I don't know what that + + + align:start position:0% +this and this. I don't know what that +means but uh number of degrees between + + align:start position:0% +means but uh number of degrees between + + + align:start position:0% +means but uh number of degrees between +this and this whatever you if you have + + align:start position:0% +this and this whatever you if you have + + + align:start position:0% +this and this whatever you if you have +some numerical data representing a + + align:start position:0% +some numerical data representing a + + + align:start position:0% +some numerical data representing a +person or a thing in your database then + + align:start position:0% +person or a thing in your database then + + + align:start position:0% +person or a thing in your database then +this is a typical kind of search you + + align:start position:0% +this is a typical kind of search you + + + align:start position:0% +this is a typical kind of search you +want to do and you want to know how many + + align:start position:0% +want to do and you want to know how many + + + align:start position:0% +want to do and you want to know how many +answers you've got and then list the + + align:start position:0% +answers you've got and then list the + + + align:start position:0% +answers you've got and then list the +first hundred of them or whatever. So + + align:start position:0% +first hundred of them or whatever. So + + + align:start position:0% +first hundred of them or whatever. So +this is a this is a practical thing in + + align:start position:0% +this is a this is a practical thing in + + + align:start position:0% +this is a this is a practical thing in +databases. It's what you might call an + + align:start position:0% +databases. It's what you might call an + + + align:start position:0% +databases. It's what you might call an +index in the database. + + align:start position:0% +index in the database. + + + align:start position:0% +index in the database. +Okay. But let's start. Suppose your data + + align:start position:0% +Okay. But let's start. Suppose your data + + + align:start position:0% +Okay. But let's start. Suppose your data +is just two dimensional. You have two + + align:start position:0% +is just two dimensional. You have two + + + align:start position:0% +is just two dimensional. You have two +fields for every item. + + align:start position:0% +fields for every item. + + + align:start position:0% +fields for every item. +What I'm going to do is store a 1D range + + align:start position:0% +What I'm going to do is store a 1D range + + + align:start position:0% +What I'm going to do is store a 1D range +tree + + align:start position:0% + + + + align:start position:0% + +on all points + + align:start position:0% + + + + align:start position:0% + +by X. + + align:start position:0% +by X. + + + align:start position:0% +by X. +So this this data structure makes sense + + align:start position:0% +So this this data structure makes sense + + + align:start position:0% +So this this data structure makes sense +if you fix a dimension. You say X is all + + align:start position:0% +if you fix a dimension. You say X is all + + + align:start position:0% +if you fix a dimension. You say X is all +I care about. Forget about Y. + + align:start position:0% +I care about. Forget about Y. + + + align:start position:0% +I care about. Forget about Y. +Still have my point set. Yeah. So + + align:start position:0% +Still have my point set. Yeah. So + + + align:start position:0% +Still have my point set. Yeah. So +what that corresponds to is projecting + + align:start position:0% +what that corresponds to is projecting + + + align:start position:0% +what that corresponds to is projecting +each of these points onto the X- axis. + + align:start position:0% + + + + align:start position:0% + +Okay. And now also projecting my query. + + align:start position:0% +Okay. And now also projecting my query. + + + align:start position:0% +Okay. And now also projecting my query. +So my new query is from here to here in + + align:start position:0% +So my new query is from here to here in + + + align:start position:0% +So my new query is from here to here in +X. + + align:start position:0% + + + + align:start position:0% + +And so this data structure will let me + + align:start position:0% +And so this data structure will let me + + + align:start position:0% +And so this data structure will let me +find all these points that match in X. + + align:start position:0% +find all these points that match in X. + + + align:start position:0% +find all these points that match in X. +Now that's not good because there's + + align:start position:0% +Now that's not good because there's + + + align:start position:0% +Now that's not good because there's +actually only two points that I want. + + align:start position:0% +actually only two points that I want. + + + align:start position:0% +actually only two points that I want. +But I find four points in this picture. + + align:start position:0% +But I find four points in this picture. + + + align:start position:0% +But I find four points in this picture. +Okay, but it's half of the answer. It's + + align:start position:0% +Okay, but it's half of the answer. It's + + + align:start position:0% +Okay, but it's half of the answer. It's +all the X matches forgetting about Y. + + align:start position:0% + + + + align:start position:0% + +Now, here's the fun part. + + align:start position:0% +Now, here's the fun part. + + + align:start position:0% +Now, here's the fun part. +So, when I do a search here, I get login + + align:start position:0% +So, when I do a search here, I get login + + + align:start position:0% +So, when I do a search here, I get login +nodes. + + align:start position:0% +nodes. + + + align:start position:0% +nodes. +Nodes are good because they have a + + align:start position:0% +Nodes are good because they have a + + + align:start position:0% +Nodes are good because they have a +single key in them. So, I'll just check + + align:start position:0% +single key in them. So, I'll just check + + + align:start position:0% +single key in them. So, I'll just check +for each of those login nodes. Do they + + align:start position:0% +for each of those login nodes. Do they + + + align:start position:0% +for each of those login nodes. Do they +also match in Y? If they do, add it to + + align:start position:0% +also match in Y? If they do, add it to + + + align:start position:0% +also match in Y? If they do, add it to +the answer. If they don't, forget about + + align:start position:0% +the answer. If they don't, forget about + + + align:start position:0% +the answer. If they don't, forget about +it. Okay. + + align:start position:0% +it. Okay. + + + align:start position:0% +it. Okay. +But the tricky part is I also get login + + align:start position:0% +But the tricky part is I also get login + + + align:start position:0% +But the tricky part is I also get login +sub trees representing parts of the + + align:start position:0% +sub trees representing parts of the + + + align:start position:0% +sub trees representing parts of the +answer. So potentially, you know, it + + align:start position:0% +answer. So potentially, you know, it + + + align:start position:0% +answer. So potentially, you know, it +could be that your search, this this + + align:start position:0% +could be that your search, this this + + + align:start position:0% +could be that your search, this this +rectangle only has like five points. But + + align:start position:0% +rectangle only has like five points. But + + + align:start position:0% +rectangle only has like five points. But +if you look at this whole vertical slab, + + align:start position:0% +if you look at this whole vertical slab, + + + align:start position:0% +if you look at this whole vertical slab, +there's a billion points. Now, luckily, + + align:start position:0% +there's a billion points. Now, luckily, + + + align:start position:0% +there's a billion points. Now, luckily, +those billion points are represented + + align:start position:0% +those billion points are represented + + + align:start position:0% +those billion points are represented +succinctly. There's just login subtree + + align:start position:0% +succinctly. There's just login subtree + + + align:start position:0% +succinctly. There's just login subtree +saying, well, there's half a billion + + align:start position:0% +saying, well, there's half a billion + + + align:start position:0% +saying, well, there's half a billion +here and a quarter billion here and an + + align:start position:0% +here and a quarter billion here and an + + + align:start position:0% +here and a quarter billion here and an +eighth of a billion here. Uh + + align:start position:0% +eighth of a billion here. Uh + + + align:start position:0% +eighth of a billion here. Uh +so + + align:start position:0% +so + + + align:start position:0% +so +can now for each of those that big chunk + + align:start position:0% +can now for each of those that big chunk + + + align:start position:0% +can now for each of those that big chunk +of output I want to very quickly find + + align:start position:0% +of output I want to very quickly find + + + align:start position:0% +of output I want to very quickly find +the ones that match in Y. How would I + + align:start position:0% +the ones that match in Y. How would I + + + align:start position:0% +the ones that match in Y. How would I +find the ones matching in Y? + + align:start position:0% + + + + align:start position:0% + +A range tree. Yeah. Okay. So here's what + + align:start position:0% +A range tree. Yeah. Okay. So here's what + + + align:start position:0% +A range tree. Yeah. Okay. So here's what +we're going to do. For each node + + align:start position:0% +we're going to do. For each node + + + align:start position:0% +we're going to do. For each node +uh let's call it X uh X X is overloaded. + + align:start position:0% +uh let's call it X uh X X is overloaded. + + + align:start position:0% +uh let's call it X uh X X is overloaded. +It's a coordinate so many things. Uh + + align:start position:0% +It's a coordinate so many things. Uh + + + align:start position:0% +It's a coordinate so many things. Uh +let's call it V. Uh in the + + align:start position:0% +let's call it V. Uh in the + + + align:start position:0% +let's call it V. Uh in the +this thing I'm going to call the X tree. + + align:start position:0% +this thing I'm going to call the X tree. + + + align:start position:0% +this thing I'm going to call the X tree. +So for every node in the x tree, I'm + + align:start position:0% +So for every node in the x tree, I'm + + + align:start position:0% +So for every node in the x tree, I'm +going to store another 1D range tree, + + align:start position:0% +going to store another 1D range tree, + + + align:start position:0% +going to store another 1D range tree, +but this time using the y-coordinate + + align:start position:0% + + + + align:start position:0% + +uh on + + align:start position:0% +uh on + + + align:start position:0% +uh on +all points + + align:start position:0% +all points + + + align:start position:0% +all points +in these rooted + + align:start position:0% +in these rooted + + + align:start position:0% +in these rooted +subree. + + align:start position:0% +subree. + + + align:start position:0% +subree. +Okay, at this point I really want to + + align:start position:0% +Okay, at this point I really want to + + + align:start position:0% +Okay, at this point I really want to +draw a diagram. + + align:start position:0% + + + + align:start position:0% + +So, uh, rough picture. + + align:start position:0% + + + + align:start position:0% + +Okay, + + align:start position:0% +Okay, + + + align:start position:0% +Okay, +forgive me for not drawing this + + align:start position:0% +forgive me for not drawing this + + + align:start position:0% +forgive me for not drawing this +perfectly. Uh this is roughly what the + + align:start position:0% +perfectly. Uh this is roughly what the + + + align:start position:0% +perfectly. Uh this is roughly what the +answer looks like + + align:start position:0% +answer looks like + + + align:start position:0% +answer looks like +for the 1D range search here. This is + + align:start position:0% +for the 1D range search here. This is + + + align:start position:0% +for the 1D range search here. This is +the X tree and here I've searched + + align:start position:0% +the X tree and here I've searched + + + align:start position:0% +the X tree and here I've searched +between this value and this value in the + + align:start position:0% +between this value and this value in the + + + align:start position:0% +between this value and this value in the +X coordinate. Basically I have login + + align:start position:0% +X coordinate. Basically I have login + + + align:start position:0% +X coordinate. Basically I have login +nodes. I'm going to check those + + align:start position:0% +nodes. I'm going to check those + + + align:start position:0% +nodes. I'm going to check those +separately. Then I also have these login + + align:start position:0% +separately. Then I also have these login + + + align:start position:0% +separately. Then I also have these login +sub trees. For each of those login + + align:start position:0% +sub trees. For each of those login + + + align:start position:0% +sub trees. For each of those login +subrees + + align:start position:0% +subrees + + + align:start position:0% +subrees +I'm going to have a pointer. This is the + + align:start position:0% +I'm going to have a pointer. This is the + + + align:start position:0% +I'm going to have a pointer. This is the +augmentation + + align:start position:0% +augmentation + + + align:start position:0% +augmentation +to uh another tree of exactly the same + + align:start position:0% +to uh another tree of exactly the same + + + align:start position:0% +to uh another tree of exactly the same +size on exactly the same data that's in + + align:start position:0% +size on exactly the same data that's in + + + align:start position:0% +size on exactly the same data that's in +here. It's also over here, but it's + + align:start position:0% +here. It's also over here, but it's + + + align:start position:0% +here. It's also over here, but it's +going to be sorted by Y. And it's a 1D + + align:start position:0% +going to be sorted by Y. And it's a 1D + + + align:start position:0% +going to be sorted by Y. And it's a 1D +range tree by Y. Tons of data + + align:start position:0% +range tree by Y. Tons of data + + + align:start position:0% +range tree by Y. Tons of data +duplication here. I took all these + + align:start position:0% +duplication here. I took all these + + + align:start position:0% +duplication here. I took all these +points and I copied them over here, but + + align:start position:0% +points and I copied them over here, but + + + align:start position:0% +points and I copied them over here, but +then built a 1D range tree in Y. This is + + align:start position:0% +then built a 1D range tree in Y. This is + + + align:start position:0% +then built a 1D range tree in Y. This is +all pre-processing, so I'm not I don't + + align:start position:0% +all pre-processing, so I'm not I don't + + + align:start position:0% +all pre-processing, so I'm not I don't +have to pay for this. It's polinomial + + align:start position:0% +have to pay for this. It's polinomial + + + align:start position:0% +have to pay for this. It's polinomial +time. Don't worry too much. Um, and then + + align:start position:0% +time. Don't worry too much. Um, and then + + + align:start position:0% +time. Don't worry too much. Um, and then +I'm going to search in here. What does + + align:start position:0% +I'm going to search in here. What does + + + align:start position:0% +I'm going to search in here. What does +the search in there look? Well, I'm + + align:start position:0% +the search in there look? Well, I'm + + + align:start position:0% +the search in there look? Well, I'm +going to get, you know, some more trees + + align:start position:0% +going to get, you know, some more trees + + + align:start position:0% +going to get, you know, some more trees +and a couple more nodes. + + align:start position:0% +and a couple more nodes. + + + align:start position:0% +and a couple more nodes. +Okay, but now those items, those points + + align:start position:0% +Okay, but now those items, those points + + + align:start position:0% +Okay, but now those items, those points +match in X and Y because this whole + + align:start position:0% +match in X and Y because this whole + + + align:start position:0% +match in X and Y because this whole +subree matched in X and I just did a Y + + align:start position:0% +subree matched in X and I just did a Y + + + align:start position:0% +subree matched in X and I just did a Y +search. So, I found things that matched + + align:start position:0% +search. So, I found things that matched + + + align:start position:0% +search. So, I found things that matched +in Y. So, I get here another login trees + + align:start position:0% +in Y. So, I get here another login trees + + + align:start position:0% +in Y. So, I get here another login trees +that are actually in my answer. And for + + align:start position:0% +that are actually in my answer. And for + + + align:start position:0% +that are actually in my answer. And for +each of these nodes, I have a + + align:start position:0% +each of these nodes, I have a + + + align:start position:0% +each of these nodes, I have a +corresponding other data structure where + + align:start position:0% +corresponding other data structure where + + + align:start position:0% +corresponding other data structure where +I find I do a little search and I get + + align:start position:0% +I find I do a little search and I get + + + align:start position:0% +I find I do a little search and I get +part of the answer. + + align:start position:0% + + + + align:start position:0% + +Okay, you get the idea. Everyone + + align:start position:0% +Okay, you get the idea. Everyone + + + align:start position:0% +Okay, you get the idea. Everyone +sounds huge. State structure sounds + + align:start position:0% +sounds huge. State structure sounds + + + align:start position:0% +sounds huge. State structure sounds +huge, but it's actually small. Uh, but + + align:start position:0% +huge, but it's actually small. Uh, but + + + align:start position:0% +huge, but it's actually small. Uh, but +one thing that's clear is it takes log + + align:start position:0% +one thing that's clear is it takes log + + + align:start position:0% +one thing that's clear is it takes log +squared n time because I have login + + align:start position:0% +squared n time because I have login + + + align:start position:0% +squared n time because I have login +triangles over here. For each of them I + + align:start position:0% +triangles over here. For each of them I + + + align:start position:0% +triangles over here. For each of them I +spend log n to find triangles over here. + + align:start position:0% +spend log n to find triangles over here. + + + align:start position:0% +spend log n to find triangles over here. +The total output is log squared nodes. + + align:start position:0% +The total output is log squared nodes. + + + align:start position:0% +The total output is log squared nodes. +For each of them I have to check + + align:start position:0% +For each of them I have to check + + + align:start position:0% +For each of them I have to check +manually plus uh and so over here I + + align:start position:0% +manually plus uh and so over here I + + + align:start position:0% +manually plus uh and so over here I +there's log n different searches I'm + + align:start position:0% +there's log n different searches I'm + + + align:start position:0% +there's log n different searches I'm +doing. Each one has size log n. So I get + + align:start position:0% +doing. Each one has size log n. So I get + + + align:start position:0% +doing. Each one has size log n. So I get +log squared little triangles that + + align:start position:0% +log squared little triangles that + + + align:start position:0% +log squared little triangles that +contain the results that match in x and + + align:start position:0% +contain the results that match in x and + + + align:start position:0% +contain the results that match in x and +y. How much space in this data + + align:start position:0% +y. How much space in this data + + + align:start position:0% +y. How much space in this data +structure? + + align:start position:0% +structure? + + + align:start position:0% +structure? +That's the remaining challenge. + + align:start position:0% +That's the remaining challenge. + + + align:start position:0% +That's the remaining challenge. +Uh + + align:start position:0% +Uh + + + align:start position:0% +Uh +actually + + align:start position:0% +actually + + + align:start position:0% +actually +it's it's not that hard because + + align:start position:0% +it's it's not that hard because + + + align:start position:0% +it's it's not that hard because +if you look at a key + + align:start position:0% +if you look at a key + + + align:start position:0% +if you look at a key +so look at some key in this X tree. + + align:start position:0% +so look at some key in this X tree. + + + align:start position:0% +so look at some key in this X tree. +Let's say look at a leaf because that's + + align:start position:0% +Let's say look at a leaf because that's + + + align:start position:0% +Let's say look at a leaf because that's +maybe the most interesting. + + align:start position:0% +maybe the most interesting. + + + align:start position:0% +maybe the most interesting. +I'm going to start start over here. + + align:start position:0% +I'm going to start start over here. + + + align:start position:0% +I'm going to start start over here. +Sorry. + + align:start position:0% +Sorry. + + + align:start position:0% +Sorry. +Here's the X tree. X tree has linear + + align:start position:0% +Here's the X tree. X tree has linear + + + align:start position:0% +Here's the X tree. X tree has linear +size just one tree. If I look at some + + align:start position:0% +size just one tree. If I look at some + + + align:start position:0% +size just one tree. If I look at some +key value, well, uh, you know, it lives + + align:start position:0% +key value, well, uh, you know, it lives + + + align:start position:0% +key value, well, uh, you know, it lives +in this subree. And so there's going to + + align:start position:0% +in this subree. And so there's going to + + + align:start position:0% +in this subree. And so there's going to +be a corresponding blue structure of + + align:start position:0% +be a corresponding blue structure of + + + align:start position:0% +be a corresponding blue structure of +that size that contains that key. And + + align:start position:0% +that size that contains that key. And + + + align:start position:0% +that size that contains that key. And +then there's the parent. So there's a + + align:start position:0% +then there's the parent. So there's a + + + align:start position:0% +then there's the parent. So there's a +structure here that has a corresponding + + align:start position:0% +structure here that has a corresponding + + + align:start position:0% +structure here that has a corresponding +blue triangle. And then its parent, + + align:start position:0% +blue triangle. And then its parent, + + + align:start position:0% +blue triangle. And then its parent, +that's another triangle that contains + + align:start position:0% +that's another triangle that contains + + + align:start position:0% +that's another triangle that contains +I'm looking at a key uh K here. All of + + align:start position:0% +I'm looking at a key uh K here. All of + + + align:start position:0% +I'm looking at a key uh K here. All of +these triangles contain the key K. And + + align:start position:0% +these triangles contain the key K. And + + + align:start position:0% +these triangles contain the key K. And +so key K will be duplicated all this + + align:start position:0% +so key K will be duplicated all this + + + align:start position:0% +so key K will be duplicated all this +many times. But how many how many sub + + align:start position:0% +many times. But how many how many sub + + + align:start position:0% +many times. But how many how many sub +trees is K in log N + + align:start position:0% +trees is K in log N + + + align:start position:0% +trees is K in log N +each key fundamental fact about uh + + align:start position:0% +each key fundamental fact about uh + + + align:start position:0% +each key fundamental fact about uh +binary balanced binary search trees. + + align:start position:0% +binary balanced binary search trees. + + + align:start position:0% +binary balanced binary search trees. +Each key lives in log sub trees namely + + align:start position:0% +Each key lives in log sub trees namely + + + align:start position:0% +Each key lives in log sub trees namely +all of its ancestors. + + align:start position:0% + + + + align:start position:0% + +Awesome. + + align:start position:0% + + + + align:start position:0% + +Because that means the total space is n + + align:start position:0% +Because that means the total space is n + + + align:start position:0% +Because that means the total space is n +login. + + align:start position:0% +login. + + + align:start position:0% +login. +There's n keys. Each of them is + + align:start position:0% +There's n keys. Each of them is + + + align:start position:0% +There's n keys. Each of them is +duplicated at most log n times. + + align:start position:0% + + + + align:start position:0% + +In general, log to the d minus one. So + + align:start position:0% +In general, log to the d minus one. So + + + align:start position:0% +In general, log to the d minus one. So +if you do it in 3D, each of the blue + + align:start position:0% +if you do it in 3D, each of the blue + + + align:start position:0% +if you do it in 3D, each of the blue +trees, every node in it has a + + align:start position:0% +trees, every node in it has a + + + align:start position:0% +trees, every node in it has a +corresponding pointer to a red tree + + align:start position:0% +corresponding pointer to a red tree + + + align:start position:0% +corresponding pointer to a red tree +that's sorted by Z. And you just keep + + align:start position:0% +that's sorted by Z. And you just keep + + + align:start position:0% +that's sorted by Z. And you just keep +doing this sort of nested searching. + + align:start position:0% +doing this sort of nested searching. + + + align:start position:0% +doing this sort of nested searching. +It's like super augmentation, but you're + + align:start position:0% +It's like super augmentation, but you're + + + align:start position:0% +It's like super augmentation, but you're +only losing a log factor each dimension + + align:start position:0% +only losing a log factor each dimension + + + align:start position:0% +only losing a log factor each dimension +you add. \ No newline at end of file diff --git a/xnEZqVz7iy4.txt b/xnEZqVz7iy4.txt new file mode 100644 index 0000000000000000000000000000000000000000..8fdafeba7196db4c55f5eeba2b8a74a1966a0244 --- /dev/null +++ b/xnEZqVz7iy4.txt @@ -0,0 +1,515 @@ +align:start position:0% + +Algorithms is an interesting area + + align:start position:0% +Algorithms is an interesting area + + + align:start position:0% +Algorithms is an interesting area +because it's it's very creative to come + + align:start position:0% +because it's it's very creative to come + + + align:start position:0% +because it's it's very creative to come +up with new algorithms. Um there's often + + align:start position:0% +up with new algorithms. Um there's often + + + align:start position:0% +up with new algorithms. Um there's often +many ways to solve the same problem. Uh + + align:start position:0% +many ways to solve the same problem. Uh + + + align:start position:0% +many ways to solve the same problem. Uh +but unlike art say and algorithms + + align:start position:0% +but unlike art say and algorithms + + + align:start position:0% +but unlike art say and algorithms +they're uh quantifiable measures for how + + align:start position:0% +they're uh quantifiable measures for how + + + align:start position:0% +they're uh quantifiable measures for how +good you did. What is the running time + + align:start position:0% +good you did. What is the running time + + + align:start position:0% +good you did. What is the running time +of the thing you ended up with? How much + + align:start position:0% +of the thing you ended up with? How much + + + align:start position:0% +of the thing you ended up with? How much +space does it use? You is it efficient? + + align:start position:0% +space does it use? You is it efficient? + + + align:start position:0% +space does it use? You is it efficient? +Um so it's nice in that you can act it's + + align:start position:0% +Um so it's nice in that you can act it's + + + align:start position:0% +Um so it's nice in that you can act it's +easy to evaluate whether you kind of + + align:start position:0% +easy to evaluate whether you kind of + + + align:start position:0% +easy to evaluate whether you kind of +succeeded. Did you get the n login and + + align:start position:0% +succeeded. Did you get the n login and + + + align:start position:0% +succeeded. Did you get the n login and +algorithm? Did you get the fastest + + align:start position:0% +algorithm? Did you get the fastest + + + align:start position:0% +algorithm? Did you get the fastest +that's possible? Um but it's hard to + + align:start position:0% +that's possible? Um but it's hard to + + + align:start position:0% +that's possible? Um but it's hard to +measure uh students understanding + + align:start position:0% +measure uh students understanding + + + align:start position:0% +measure uh students understanding +because it's like did you get the + + align:start position:0% +because it's like did you get the + + + align:start position:0% +because it's like did you get the +creative trick that we had in mind or + + align:start position:0% +creative trick that we had in mind or + + + align:start position:0% +creative trick that we had in mind or +find another one that's just as good. U + + align:start position:0% +find another one that's just as good. U + + + align:start position:0% +find another one that's just as good. U +students may find a different creative + + align:start position:0% +students may find a different creative + + + align:start position:0% +students may find a different creative +trick that doesn't end up with as good + + align:start position:0% +trick that doesn't end up with as good + + + align:start position:0% +trick that doesn't end up with as good +an algorithm in the end. So uh we + + align:start position:0% +an algorithm in the end. So uh we + + + align:start position:0% +an algorithm in the end. So uh we +penalize that somewhat but for the most + + align:start position:0% +penalize that somewhat but for the most + + + align:start position:0% +penalize that somewhat but for the most +part we are happy when people get + + align:start position:0% +part we are happy when people get + + + align:start position:0% +part we are happy when people get +correct algorithms when they they + + align:start position:0% +correct algorithms when they they + + + align:start position:0% +correct algorithms when they they +understand the techniques well enough + + align:start position:0% +understand the techniques well enough + + + align:start position:0% +understand the techniques well enough +that they get an algorithm it's pretty + + align:start position:0% +that they get an algorithm it's pretty + + + align:start position:0% +that they get an algorithm it's pretty +good may not be the best uh but we + + align:start position:0% +good may not be the best uh but we + + + align:start position:0% +good may not be the best uh but we +consider that much better than they were + + align:start position:0% +consider that much better than they were + + + align:start position:0% +consider that much better than they were +using the right technique but they ended + + align:start position:0% +using the right technique but they ended + + + align:start position:0% +using the right technique but they ended +up using it wrong and so they end up + + align:start position:0% +up using it wrong and so they end up + + + align:start position:0% +up using it wrong and so they end up +with something that doesn't even work + + align:start position:0% +with something that doesn't even work + + + align:start position:0% +with something that doesn't even work +and that's that's much more uh + + align:start position:0% +and that's that's much more uh + + + align:start position:0% +and that's that's much more uh +discouraging I Yes. Um, but in any case, + + align:start position:0% +discouraging I Yes. Um, but in any case, + + + align:start position:0% +discouraging I Yes. Um, but in any case, +in a timed exam, it's really hard to + + align:start position:0% +in a timed exam, it's really hard to + + + align:start position:0% +in a timed exam, it's really hard to +expect students to be creative. So, in + + align:start position:0% +expect students to be creative. So, in + + + align:start position:0% +expect students to be creative. So, in +that setting, it's hard. We don't expect + + align:start position:0% +that setting, it's hard. We don't expect + + + align:start position:0% +that setting, it's hard. We don't expect +a lot of creativity. We try to keep the + + align:start position:0% +a lot of creativity. We try to keep the + + + align:start position:0% +a lot of creativity. We try to keep the +questions relatively simple. So, you + + align:start position:0% +questions relatively simple. So, you + + + align:start position:0% +questions relatively simple. So, you +need just one simple idea. If you're + + align:start position:0% +need just one simple idea. If you're + + + align:start position:0% +need just one simple idea. If you're +familiar with the material, it should + + align:start position:0% +familiar with the material, it should + + + align:start position:0% +familiar with the material, it should +come quickly. Doesn't always, but um, so + + align:start position:0% +come quickly. Doesn't always, but um, so + + + align:start position:0% +come quickly. Doesn't always, but um, so +problem sets are definitely an easier + + align:start position:0% +problem sets are definitely an easier + + + align:start position:0% +problem sets are definitely an easier +way for students to express creativity. + + align:start position:0% +way for students to express creativity. + + + align:start position:0% +way for students to express creativity. +gives them a little more time to think + + align:start position:0% +gives them a little more time to think + + + align:start position:0% +gives them a little more time to think +about the problem. Uh because some + + align:start position:0% +about the problem. Uh because some + + + align:start position:0% +about the problem. Uh because some +problems are going to come easy to some + + align:start position:0% +problems are going to come easy to some + + + align:start position:0% +problems are going to come easy to some +students and hard to others. It's going + + align:start position:0% +students and hard to others. It's going + + + align:start position:0% +students and hard to others. It's going +to be different each problem set. So + + align:start position:0% +to be different each problem set. So + + + align:start position:0% +to be different each problem set. So +that gives them they have a week to + + align:start position:0% +that gives them they have a week to + + + align:start position:0% +that gives them they have a week to +think about it and also to talk to + + align:start position:0% +think about it and also to talk to + + + align:start position:0% +think about it and also to talk to +others. We allow collaboration in the + + align:start position:0% +others. We allow collaboration in the + + + align:start position:0% +others. We allow collaboration in the +problem sets. So that makes it a lot + + align:start position:0% +problem sets. So that makes it a lot + + + align:start position:0% +problem sets. So that makes it a lot +easier to find solutions but still learn + + align:start position:0% +easier to find solutions but still learn + + + align:start position:0% +easier to find solutions but still learn +learn a lot from it. In the exams it's a + + align:start position:0% +learn a lot from it. In the exams it's a + + + align:start position:0% +learn a lot from it. In the exams it's a +lot harder. Um, in past years, we've + + align:start position:0% +lot harder. Um, in past years, we've + + + align:start position:0% +lot harder. Um, in past years, we've +tried uh take-home exams as a way to + + align:start position:0% +tried uh take-home exams as a way to + + + align:start position:0% +tried uh take-home exams as a way to +more accurately gauge how creative + + align:start position:0% +more accurately gauge how creative + + + align:start position:0% +more accurately gauge how creative +someone is in applying these techniques + + align:start position:0% +someone is in applying these techniques + + + align:start position:0% +someone is in applying these techniques +to design new algorithms. Uh, we didn't + + align:start position:0% +to design new algorithms. Uh, we didn't + + + align:start position:0% +to design new algorithms. Uh, we didn't +do that this year. Um, it's not clear + + align:start position:0% +do that this year. Um, it's not clear + + + align:start position:0% +do that this year. Um, it's not clear +what the right answer is. It's a + + align:start position:0% +what the right answer is. It's a + + + align:start position:0% +what the right answer is. It's a +definitely a challenge in teaching + + align:start position:0% +definitely a challenge in teaching + + + align:start position:0% +definitely a challenge in teaching +algorithms is how to evaluate whether + + align:start position:0% +algorithms is how to evaluate whether + + + align:start position:0% +algorithms is how to evaluate whether +someone can really apply the techniques + + align:start position:0% +someone can really apply the techniques + + + align:start position:0% +someone can really apply the techniques +in new and creative ways. \ No newline at end of file diff --git a/y4uc4t5vcdI.txt b/y4uc4t5vcdI.txt new file mode 100644 index 0000000000000000000000000000000000000000..91358beeb5b2bbc1b9f2eeb2899a94e82ad05bfe --- /dev/null +++ b/y4uc4t5vcdI.txt @@ -0,0 +1,14371 @@ +align:start position:0% + +The following content is provided under + + align:start position:0% +The following content is provided under + + + align:start position:0% +The following content is provided under +a creative common license. Your support + + align:start position:0% +a creative common license. Your support + + + align:start position:0% +a creative common license. Your support +will help MIT Open Courseware continue + + align:start position:0% +will help MIT Open Courseware continue + + + align:start position:0% +will help MIT Open Courseware continue +to offer high-quality educational + + align:start position:0% +to offer high-quality educational + + + align:start position:0% +to offer high-quality educational +resources for free. To make a donation + + align:start position:0% +resources for free. To make a donation + + + align:start position:0% +resources for free. To make a donation +or view additional materials from + + align:start position:0% +or view additional materials from + + + align:start position:0% +or view additional materials from +hundreds of MIT courses, visit MIT Open + + align:start position:0% +hundreds of MIT courses, visit MIT Open + + + align:start position:0% +hundreds of MIT courses, visit MIT Open +Courseware at ocw.mmit.edu. + + align:start position:0% + + + + align:start position:0% + +There were a couple questions on + + align:start position:0% +There were a couple questions on + + + align:start position:0% +There were a couple questions on +estimations. So, one person was as asked + + align:start position:0% +estimations. So, one person was as asked + + + align:start position:0% +estimations. So, one person was as asked +for answers to estimations. I try to + + align:start position:0% +for answers to estimations. I try to + + + align:start position:0% +for answers to estimations. I try to +give you orders of magnitude and give + + align:start position:0% +give you orders of magnitude and give + + + align:start position:0% +give you orders of magnitude and give +you a sense, but if I've missed some, + + align:start position:0% +you a sense, but if I've missed some, + + + align:start position:0% +you a sense, but if I've missed some, +let if you want to like email me and be + + align:start position:0% +let if you want to like email me and be + + + align:start position:0% +let if you want to like email me and be +like, "Hey, I never I never really got + + align:start position:0% +like, "Hey, I never I never really got + + + align:start position:0% +like, "Hey, I never I never really got +this one, let me know and I can review + + align:start position:0% +this one, let me know and I can review + + + align:start position:0% +this one, let me know and I can review +them." Um, and then also the other thing + + align:start position:0% +them." Um, and then also the other thing + + + align:start position:0% +them." Um, and then also the other thing +is I'm never going to give you a like + + align:start position:0% +is I'm never going to give you a like + + + align:start position:0% +is I'm never going to give you a like +6.7 answer because I'm rarely asking you + + align:start position:0% +6.7 answer because I'm rarely asking you + + + align:start position:0% +6.7 answer because I'm rarely asking you +an estimation that has that kind of + + align:start position:0% +an estimation that has that kind of + + + align:start position:0% +an estimation that has that kind of +answer. like some of them do, but + + align:start position:0% +answer. like some of them do, but + + + align:start position:0% +answer. like some of them do, but +usually it's not even that important + + align:start position:0% +usually it's not even that important + + + align:start position:0% +usually it's not even that important +that you get to 6.7. It's important that + + align:start position:0% +that you get to 6.7. It's important that + + + align:start position:0% +that you get to 6.7. It's important that +you get to an order of magnitude of 10. + + align:start position:0% +you get to an order of magnitude of 10. + + + align:start position:0% +you get to an order of magnitude of 10. +And as long as you're there, I'm happy. + + align:start position:0% +And as long as you're there, I'm happy. + + + align:start position:0% +And as long as you're there, I'm happy. +And so that's why I'm not getting to the + + align:start position:0% +And so that's why I'm not getting to the + + + align:start position:0% +And so that's why I'm not getting to the +exact answer, which I know is + + align:start position:0% +exact answer, which I know is + + + align:start position:0% +exact answer, which I know is +uncomfortable and not what you're used + + align:start position:0% +uncomfortable and not what you're used + + + align:start position:0% +uncomfortable and not what you're used +to um educationally, but it's what the + + align:start position:0% +to um educationally, but it's what the + + + align:start position:0% +to um educationally, but it's what the +estimation is there for. Um, another + + align:start position:0% +estimation is there for. Um, another + + + align:start position:0% +estimation is there for. Um, another +person mentioned that uh some people + + align:start position:0% +person mentioned that uh some people + + + align:start position:0% +person mentioned that uh some people +seem like they were taking a really long + + align:start position:0% +seem like they were taking a really long + + + align:start position:0% +seem like they were taking a really long +time and getting sort of lost in the + + align:start position:0% +time and getting sort of lost in the + + + align:start position:0% +time and getting sort of lost in the +estimations. Um so I try to give you the + + align:start position:0% +estimations. Um so I try to give you the + + + align:start position:0% +estimations. Um so I try to give you the +right amount of time for the estimation + + align:start position:0% +right amount of time for the estimation + + + align:start position:0% +right amount of time for the estimation +so that it's reasonable but it is + + align:start position:0% +so that it's reasonable but it is + + + align:start position:0% +so that it's reasonable but it is +something to practice + + align:start position:0% +something to practice + + + align:start position:0% +something to practice +getting more fasile with I guess. All + + align:start position:0% +getting more fasile with I guess. All + + + align:start position:0% +getting more fasile with I guess. All +right so wind energy. So does anyone + + align:start position:0% +right so wind energy. So does anyone + + + align:start position:0% +right so wind energy. So does anyone +know why we have wind on the earth? + + align:start position:0% + + + + align:start position:0% + +Yeah + + align:start position:0% +Yeah + + + align:start position:0% +Yeah +because we have heat. + + align:start position:0% +because we have heat. + + + align:start position:0% +because we have heat. +Yes. From + + align:start position:0% +Yes. From + + + align:start position:0% +Yes. From +sun. + + align:start position:0% +sun. + + + align:start position:0% +sun. +Yes. So, it's kind of funny because wind + + align:start position:0% +Yes. So, it's kind of funny because wind + + + align:start position:0% +Yes. So, it's kind of funny because wind +energy is basically a funky solar + + align:start position:0% +energy is basically a funky solar + + + align:start position:0% +energy is basically a funky solar +energy, which I I find I find pleasing. + + align:start position:0% +energy, which I I find I find pleasing. + + + align:start position:0% +energy, which I I find I find pleasing. +I don't know why, but I do. Um, there's + + align:start position:0% +I don't know why, but I do. Um, there's + + + align:start position:0% +I don't know why, but I do. Um, there's +also some coriololis effect stuff going + + align:start position:0% +also some coriololis effect stuff going + + + align:start position:0% +also some coriololis effect stuff going +around on with the the Earth rotating, + + align:start position:0% +around on with the the Earth rotating, + + + align:start position:0% +around on with the the Earth rotating, +but the um indirect solar energy + + align:start position:0% +but the um indirect solar energy + + + align:start position:0% +but the um indirect solar energy +component is uh more + + align:start position:0% +component is uh more + + + align:start position:0% +component is uh more +more easy to think about and I I think I + + align:start position:0% +more easy to think about and I I think I + + + align:start position:0% +more easy to think about and I I think I +think is the bigger component, though + + align:start position:0% +think is the bigger component, though + + + align:start position:0% +think is the bigger component, though +I'm not sure of that. Um so basically + + align:start position:0% +I'm not sure of that. Um so basically + + + align:start position:0% +I'm not sure of that. Um so basically +you have uneating even heating of the + + align:start position:0% +you have uneating even heating of the + + + align:start position:0% +you have uneating even heating of the +earth. Um hot air rises causes a + + align:start position:0% +earth. Um hot air rises causes a + + + align:start position:0% +earth. Um hot air rises causes a +pressure drop cold air rushes in and + + align:start position:0% +pressure drop cold air rushes in and + + + align:start position:0% +pressure drop cold air rushes in and +that movement is is what we're getting + + align:start position:0% +that movement is is what we're getting + + + align:start position:0% +that movement is is what we're getting +in wind. So that's + + align:start position:0% +in wind. So that's + + + align:start position:0% +in wind. So that's +what's going on there. Um, and then a + + align:start position:0% +what's going on there. Um, and then a + + + align:start position:0% +what's going on there. Um, and then a +lot of confusion sometimes happens like + + align:start position:0% +lot of confusion sometimes happens like + + + align:start position:0% +lot of confusion sometimes happens like +a lot of people see these turbines on or + + align:start position:0% +a lot of people see these turbines on or + + + align:start position:0% +a lot of people see these turbines on or +not turbines but mills on farms and it's + + align:start position:0% +not turbines but mills on farms and it's + + + align:start position:0% +not turbines but mills on farms and it's +confusing like what's this versus this? + + align:start position:0% +confusing like what's this versus this? + + + align:start position:0% +confusing like what's this versus this? +Is this just a junky version of this? + + align:start position:0% +Is this just a junky version of this? + + + align:start position:0% +Is this just a junky version of this? +And so the difference is if it's a mill, + + align:start position:0% +And so the difference is if it's a mill, + + + align:start position:0% +And so the difference is if it's a mill, +it's extracting mechanical power versus + + align:start position:0% +it's extracting mechanical power versus + + + align:start position:0% +it's extracting mechanical power versus +a turbine is extracting electrical + + align:start position:0% +a turbine is extracting electrical + + + align:start position:0% +a turbine is extracting electrical +power. So these mills are um + + align:start position:0% +power. So these mills are um + + + align:start position:0% +power. So these mills are um +very high torque devices that um move + + align:start position:0% +very high torque devices that um move + + + align:start position:0% +very high torque devices that um move +relatively slowly um in terms of their + + align:start position:0% +relatively slowly um in terms of their + + + align:start position:0% +relatively slowly um in terms of their +rotation and are used to do things like + + align:start position:0% +rotation and are used to do things like + + + align:start position:0% +rotation and are used to do things like +pump water or grind grain. They've been + + align:start position:0% +pump water or grind grain. They've been + + + align:start position:0% +pump water or grind grain. They've been +around forever. They're still really + + align:start position:0% +around forever. They're still really + + + align:start position:0% +around forever. They're still really +common in the US and in many places for + + align:start position:0% +common in the US and in many places for + + + align:start position:0% +common in the US and in many places for +pumping water. So if you drive across + + align:start position:0% +pumping water. So if you drive across + + + align:start position:0% +pumping water. So if you drive across +the country, you'll see these + + align:start position:0% +the country, you'll see these + + + align:start position:0% +the country, you'll see these +everywhere. Um, and they're still in use + + align:start position:0% +everywhere. Um, and they're still in use + + + align:start position:0% +everywhere. Um, and they're still in use +and they're really nice and a whole lot + + align:start position:0% +and they're really nice and a whole lot + + + align:start position:0% +and they're really nice and a whole lot +cheaper to build a mill than to build a + + align:start position:0% +cheaper to build a mill than to build a + + + align:start position:0% +cheaper to build a mill than to build a +turbine because you're you're going from + + align:start position:0% +turbine because you're you're going from + + + align:start position:0% +turbine because you're you're going from +mechanical work to mechanical work. So + + align:start position:0% +mechanical work to mechanical work. So + + + align:start position:0% +mechanical work to mechanical work. So +that's very direct and much much cheaper + + align:start position:0% +that's very direct and much much cheaper + + + align:start position:0% +that's very direct and much much cheaper +than doing the extra steps to get from + + align:start position:0% +than doing the extra steps to get from + + + align:start position:0% +than doing the extra steps to get from +um mechanical work to electric power + + align:start position:0% +um mechanical work to electric power + + + align:start position:0% +um mechanical work to electric power +generation. So a wind turbine in + + align:start position:0% +generation. So a wind turbine in + + + align:start position:0% +generation. So a wind turbine in +contrast is electrical power. They have + + align:start position:0% +contrast is electrical power. They have + + + align:start position:0% +contrast is electrical power. They have +been around a long time too, but not not + + align:start position:0% +been around a long time too, but not not + + + align:start position:0% +been around a long time too, but not not +you know basically for most of humanity + + align:start position:0% +you know basically for most of humanity + + + align:start position:0% +you know basically for most of humanity +long time. Um + + align:start position:0% +long time. Um + + + align:start position:0% +long time. Um +and again they're uh they're going to be + + align:start position:0% +and again they're uh they're going to be + + + align:start position:0% +and again they're uh they're going to be +moving very quickly at um much slower + + align:start position:0% +moving very quickly at um much slower + + + align:start position:0% +moving very quickly at um much slower +torque. The the solidity thing to think + + align:start position:0% +torque. The the solidity thing to think + + + align:start position:0% +torque. The the solidity thing to think +about is that when you want high torque, + + align:start position:0% +about is that when you want high torque, + + + align:start position:0% +about is that when you want high torque, +you want to be getting as much of the + + align:start position:0% +you want to be getting as much of the + + + align:start position:0% +you want to be getting as much of the +air hitting your blades as possible. So + + align:start position:0% +air hitting your blades as possible. So + + + align:start position:0% +air hitting your blades as possible. So +that's why there's often many many + + align:start position:0% +that's why there's often many many + + + align:start position:0% +that's why there's often many many +blades or really thick blades on a + + align:start position:0% +blades or really thick blades on a + + + align:start position:0% +blades or really thick blades on a +windmill. Whereas a wind turbine, you + + align:start position:0% +windmill. Whereas a wind turbine, you + + + align:start position:0% +windmill. Whereas a wind turbine, you +want um + + align:start position:0% +want um + + + align:start position:0% +want um +low solidity. So you want a low + + align:start position:0% +low solidity. So you want a low + + + align:start position:0% +low solidity. So you want a low +proportion of your blade to be in that + + align:start position:0% +proportion of your blade to be in that + + + align:start position:0% +proportion of your blade to be in that +swept area. So that's why a turbine is + + align:start position:0% +swept area. So that's why a turbine is + + + align:start position:0% +swept area. So that's why a turbine is +it looks very different. + + align:start position:0% + + + + align:start position:0% + +Um so wind turbines I'm going to focus + + align:start position:0% +Um so wind turbines I'm going to focus + + + align:start position:0% +Um so wind turbines I'm going to focus +on. Um but I will go back to windmills a + + align:start position:0% +on. Um but I will go back to windmills a + + + align:start position:0% +on. Um but I will go back to windmills a +little bit at the end. + + align:start position:0% +little bit at the end. + + + align:start position:0% +little bit at the end. +um + + align:start position:0% + + + + align:start position:0% + +you have two types, right? The + + align:start position:0% +you have two types, right? The + + + align:start position:0% +you have two types, right? The +horizontal and the vertical axis. The + + align:start position:0% +horizontal and the vertical axis. The + + + align:start position:0% +horizontal and the vertical axis. The +vertical the horizontal axis is what + + align:start position:0% +vertical the horizontal axis is what + + + align:start position:0% +vertical the horizontal axis is what +you're used to seeing around here. Um + + align:start position:0% +you're used to seeing around here. Um + + + align:start position:0% +you're used to seeing around here. Um +and what's in the news a lot um because + + align:start position:0% +and what's in the news a lot um because + + + align:start position:0% +and what's in the news a lot um because +they can go to much higher heights and + + align:start position:0% +they can go to much higher heights and + + + align:start position:0% +they can go to much higher heights and +wind is much better the higher you go + + align:start position:0% +wind is much better the higher you go + + + align:start position:0% +wind is much better the higher you go +basically. Um, and so the horizontal + + align:start position:0% +basically. Um, and so the horizontal + + + align:start position:0% +basically. Um, and so the horizontal +wind axis turbines are um + + align:start position:0% +wind axis turbines are um + + + align:start position:0% +wind axis turbines are um +the more common thing at least in in my + + align:start position:0% +the more common thing at least in in my + + + align:start position:0% +the more common thing at least in in my +knowledge before I started doing any + + align:start position:0% +knowledge before I started doing any + + + align:start position:0% +knowledge before I started doing any +research into them. So there's the rotor + + align:start position:0% +research into them. So there's the rotor + + + align:start position:0% +research into them. So there's the rotor +and the mo the motor are at the top. It + + align:start position:0% +and the mo the motor are at the top. It + + + align:start position:0% +and the mo the motor are at the top. It +has to point into the wind. Um + + align:start position:0% +has to point into the wind. Um + + + align:start position:0% +has to point into the wind. Um +the higher you go the better. Um but you + + align:start position:0% +the higher you go the better. Um but you + + + align:start position:0% +the higher you go the better. Um but you +can imagine the higher you go adds costs + + align:start position:0% +can imagine the higher you go adds costs + + + align:start position:0% +can imagine the higher you go adds costs +and difficulty. Um, you often try to + + align:start position:0% +and difficulty. Um, you often try to + + + align:start position:0% +and difficulty. Um, you often try to +change your blade pitch to maximize the + + align:start position:0% +change your blade pitch to maximize the + + + align:start position:0% +change your blade pitch to maximize the +efficiency because depending on how fast + + align:start position:0% +efficiency because depending on how fast + + + align:start position:0% +efficiency because depending on how fast +the wind is, you want a different blade + + align:start position:0% +the wind is, you want a different blade + + + align:start position:0% +the wind is, you want a different blade +pitch. Um, and they're now really + + align:start position:0% +pitch. Um, and they're now really + + + align:start position:0% +pitch. Um, and they're now really +insanely huge. + + align:start position:0% +insanely huge. + + + align:start position:0% +insanely huge. +So + + align:start position:0% +So + + + align:start position:0% +So +this is an insanely huge um se seven + + align:start position:0% +this is an insanely huge um se seven + + + align:start position:0% +this is an insanely huge um se seven +megawatt turbine which um I think you + + align:start position:0% +megawatt turbine which um I think you + + + align:start position:0% +megawatt turbine which um I think you +can sort of see like + + align:start position:0% +can sort of see like + + + align:start position:0% +can sort of see like +is there a truck down there or anything? + + align:start position:0% +is there a truck down there or anything? + + + align:start position:0% +is there a truck down there or anything? +It's it's hard to get scale when it gets + + align:start position:0% +It's it's hard to get scale when it gets + + + align:start position:0% +It's it's hard to get scale when it gets +this big but it's ridiculous. And some + + align:start position:0% +this big but it's ridiculous. And some + + + align:start position:0% +this big but it's ridiculous. And some +of the challenges you can imagine in + + align:start position:0% +of the challenges you can imagine in + + + align:start position:0% +of the challenges you can imagine in +building this thing is just getting all + + align:start position:0% +building this thing is just getting all + + + align:start position:0% +building this thing is just getting all +the materials to the site because you're + + align:start position:0% +the materials to the site because you're + + + align:start position:0% +the materials to the site because you're +probably not going to build your + + align:start position:0% +probably not going to build your + + + align:start position:0% +probably not going to build your +manufacturing plant of how how you build + + align:start position:0% +manufacturing plant of how how you build + + + align:start position:0% +manufacturing plant of how how you build +your your uh + + align:start position:0% + + + + align:start position:0% + +I'm still a little off the long blade + + align:start position:0% +I'm still a little off the long blade + + + align:start position:0% +I'm still a little off the long blade +blade. Thank you. + + align:start position:0% +blade. Thank you. + + + align:start position:0% +blade. Thank you. +You know, you're not going to build your + + align:start position:0% +You know, you're not going to build your + + + align:start position:0% +You know, you're not going to build your +blade right on the site where you're + + align:start position:0% +blade right on the site where you're + + + align:start position:0% +blade right on the site where you're +going to want to install your turbine + + align:start position:0% +going to want to install your turbine + + + align:start position:0% +going to want to install your turbine +probably. So then you have to get your + + align:start position:0% +probably. So then you have to get your + + + align:start position:0% +probably. So then you have to get your +blade there. So then you're actually + + align:start position:0% +blade there. So then you're actually + + + align:start position:0% +blade there. So then you're actually +limited by like the size of a train + + align:start position:0% +limited by like the size of a train + + + align:start position:0% +limited by like the size of a train +railroad car or a large truck or + + align:start position:0% +railroad car or a large truck or + + + align:start position:0% +railroad car or a large truck or +whatever. So there's all these crazy + + align:start position:0% +whatever. So there's all these crazy + + + align:start position:0% +whatever. So there's all these crazy +limits when you're getting up to be this + + align:start position:0% +limits when you're getting up to be this + + + align:start position:0% +limits when you're getting up to be this +enormous. Um + + align:start position:0% +enormous. Um + + + align:start position:0% +enormous. Um +so it's uh kind of remarkable and + + align:start position:0% +so it's uh kind of remarkable and + + + align:start position:0% +so it's uh kind of remarkable and +challenging and this is on of a scale + + align:start position:0% +challenging and this is on of a scale + + + align:start position:0% +challenging and this is on of a scale +that we're not going to be touching of + + align:start position:0% +that we're not going to be touching of + + + align:start position:0% +that we're not going to be touching of +course. Um but it's nice to sort of see + + align:start position:0% +course. Um but it's nice to sort of see + + + align:start position:0% +course. Um but it's nice to sort of see +the extreme of of what is out there. Um, + + align:start position:0% +the extreme of of what is out there. Um, + + + align:start position:0% +the extreme of of what is out there. Um, +so this is a 7 megawatt turbine that's + + align:start position:0% +so this is a 7 megawatt turbine that's + + + align:start position:0% +so this is a 7 megawatt turbine that's +actually running now, I believe, and + + align:start position:0% +actually running now, I believe, and + + + align:start position:0% +actually running now, I believe, and +they're currently building a 10 megawatt + + align:start position:0% +they're currently building a 10 megawatt + + + align:start position:0% +they're currently building a 10 megawatt +that'll be in production in a year or + + align:start position:0% +that'll be in production in a year or + + + align:start position:0% +that'll be in production in a year or +running in a year or two. So, um, which + + align:start position:0% +running in a year or two. So, um, which + + + align:start position:0% +running in a year or two. So, um, which +is a pretty big jump, 7 to 10. So, um, + + align:start position:0% +is a pretty big jump, 7 to 10. So, um, + + + align:start position:0% +is a pretty big jump, 7 to 10. So, um, +yeah, it's it's definitely an area + + align:start position:0% +yeah, it's it's definitely an area + + + align:start position:0% +yeah, it's it's definitely an area +that's taking off. Um, so how + + align:start position:0% +that's taking off. Um, so how + + + align:start position:0% +that's taking off. Um, so how +this is just classic sort of Berni + + align:start position:0% +this is just classic sort of Berni + + + align:start position:0% +this is just classic sort of Berni +drawing um to remind you how they're + + align:start position:0% +drawing um to remind you how they're + + + align:start position:0% +drawing um to remind you how they're +spinning in the wind and that the the + + align:start position:0% +spinning in the wind and that the the + + + align:start position:0% +spinning in the wind and that the the +motion is really dominated by lift not + + align:start position:0% +motion is really dominated by lift not + + + align:start position:0% +motion is really dominated by lift not +drag. Um, one thing to think about is + + align:start position:0% +drag. Um, one thing to think about is + + + align:start position:0% +drag. Um, one thing to think about is +the need to control the spin rate. Um, + + align:start position:0% +the need to control the spin rate. Um, + + + align:start position:0% +the need to control the spin rate. Um, +so you can imagine on days where there's + + align:start position:0% +so you can imagine on days where there's + + + align:start position:0% +so you can imagine on days where there's +not much wind, you might want to change + + align:start position:0% +not much wind, you might want to change + + + align:start position:0% +not much wind, you might want to change +the pitch of the blade to make sure + + align:start position:0% +the pitch of the blade to make sure + + + align:start position:0% +the pitch of the blade to make sure +you're maximizing um the wind you're + + align:start position:0% +you're maximizing um the wind you're + + + align:start position:0% +you're maximizing um the wind you're +capturing. But on hurricane days, you um + + align:start position:0% +capturing. But on hurricane days, you um + + + align:start position:0% +capturing. But on hurricane days, you um +have to make sure that your your wind + + align:start position:0% +have to make sure that your your wind + + + align:start position:0% +have to make sure that your your wind +turbine doesn't completely uh just spin + + align:start position:0% +turbine doesn't completely uh just spin + + + align:start position:0% +turbine doesn't completely uh just spin +out of control. And so this is a really + + align:start position:0% +out of control. And so this is a really + + + align:start position:0% +out of control. And so this is a really +nice relatively simple way to do it. So + + align:start position:0% +nice relatively simple way to do it. So + + + align:start position:0% +nice relatively simple way to do it. So +you can do it mechanically or um + + align:start position:0% +you can do it mechanically or um + + + align:start position:0% +you can do it mechanically or um +electrically or you can do it like + + align:start position:0% +electrically or you can do it like + + + align:start position:0% +electrically or you can do it like +manually. So like old wind turbines from + + align:start position:0% +manually. So like old wind turbines from + + + align:start position:0% +manually. So like old wind turbines from +wind windmills from you know 100 or 200 + + align:start position:0% +wind windmills from you know 100 or 200 + + + align:start position:0% +wind windmills from you know 100 or 200 +years ago there was some poor guy whose + + align:start position:0% +years ago there was some poor guy whose + + + align:start position:0% +years ago there was some poor guy whose +job it was is to turn the turbine into + + align:start position:0% +job it was is to turn the turbine into + + + align:start position:0% +job it was is to turn the turbine into +the wind mill into the wind or not + + align:start position:0% +the wind mill into the wind or not + + + align:start position:0% +the wind mill into the wind or not +depending on how fast it was. So + + align:start position:0% +depending on how fast it was. So + + + align:start position:0% +depending on how fast it was. So +thankfully that there's been ways to + + align:start position:0% +thankfully that there's been ways to + + + align:start position:0% +thankfully that there's been ways to +optimize that either mechanically or + + align:start position:0% +optimize that either mechanically or + + + align:start position:0% +optimize that either mechanically or +um electrically. So this is a method + + align:start position:0% +um electrically. So this is a method + + + align:start position:0% +um electrically. So this is a method +where basically the + + align:start position:0% +where basically the + + + align:start position:0% +where basically the +weight of the tail and the turbine + + align:start position:0% +weight of the tail and the turbine + + + align:start position:0% +weight of the tail and the turbine +allows the tail to um stay connected to + + align:start position:0% +allows the tail to um stay connected to + + + align:start position:0% +allows the tail to um stay connected to +the the turbine so that the tail I'm + + align:start position:0% +the the turbine so that the tail I'm + + + align:start position:0% +the the turbine so that the tail I'm +getting lots of cute faces so I'll go + + align:start position:0% +getting lots of cute faces so I'll go + + + align:start position:0% +getting lots of cute faces so I'll go +slowly. Um so the turbine generally + + align:start position:0% +slowly. Um so the turbine generally + + + align:start position:0% +slowly. Um so the turbine generally +has a tail that's exactly + + align:start position:0% +has a tail that's exactly + + + align:start position:0% +has a tail that's exactly +um + + align:start position:0% +um + + + align:start position:0% +um +perpendicular. So this plane and the + + align:start position:0% +perpendicular. So this plane and the + + + align:start position:0% +perpendicular. So this plane and the +plane of the tail are perpendicular, + + align:start position:0% +plane of the tail are perpendicular, + + + align:start position:0% +plane of the tail are perpendicular, +right? So that the tail make sure it's + + align:start position:0% +right? So that the tail make sure it's + + + align:start position:0% +right? So that the tail make sure it's +always pointing into the wind, which is + + align:start position:0% +always pointing into the wind, which is + + + align:start position:0% +always pointing into the wind, which is +what you want, except when you're going + + align:start position:0% +what you want, except when you're going + + + align:start position:0% +what you want, except when you're going +too fast. Now you need the tail and the + + align:start position:0% +too fast. Now you need the tail and the + + + align:start position:0% +too fast. Now you need the tail and the +front of the turbine to not be + + align:start position:0% +front of the turbine to not be + + + align:start position:0% +front of the turbine to not be +perpendicular, but to start to to if + + align:start position:0% +perpendicular, but to start to to if + + + align:start position:0% +perpendicular, but to start to to if +hypothetically if you're in gales, you + + align:start position:0% +hypothetically if you're in gales, you + + + align:start position:0% +hypothetically if you're in gales, you +need it to be 100, you know, completely + + align:start position:0% +need it to be 100, you know, completely + + + align:start position:0% +need it to be 100, you know, completely +um rotated so that the wind is just + + align:start position:0% +um rotated so that the wind is just + + + align:start position:0% +um rotated so that the wind is just +passing by the turbine. or if you're in + + align:start position:0% +passing by the turbine. or if you're in + + + align:start position:0% +passing by the turbine. or if you're in +a moderate wind where it's too fast for + + align:start position:0% +a moderate wind where it's too fast for + + + align:start position:0% +a moderate wind where it's too fast for +the turbine but still um usable, you + + align:start position:0% +the turbine but still um usable, you + + + align:start position:0% +the turbine but still um usable, you +want it to be off a little bit. And so + + align:start position:0% +want it to be off a little bit. And so + + + align:start position:0% +want it to be off a little bit. And so +the way this works is that when the wind + + align:start position:0% +the way this works is that when the wind + + + align:start position:0% +the way this works is that when the wind +speed gets high enough, you get some + + align:start position:0% +speed gets high enough, you get some + + + align:start position:0% +speed gets high enough, you get some +lift in either the tail or the turbine. + + align:start position:0% +lift in either the tail or the turbine. + + + align:start position:0% +lift in either the tail or the turbine. +I forget how how it operates exactly. + + align:start position:0% +I forget how how it operates exactly. + + + align:start position:0% +I forget how how it operates exactly. +And so that allows this tail stop to be + + align:start position:0% +And so that allows this tail stop to be + + + align:start position:0% +And so that allows this tail stop to be +disengaged. So then the turbine rotates + + align:start position:0% +disengaged. So then the turbine rotates + + + align:start position:0% +disengaged. So then the turbine rotates +a little bit which you can sort of see + + align:start position:0% +a little bit which you can sort of see + + + align:start position:0% +a little bit which you can sort of see +from this top view. These are the front + + align:start position:0% +from this top view. These are the front + + + align:start position:0% +from this top view. These are the front +views and this is the top view. So then + + align:start position:0% +views and this is the top view. So then + + + align:start position:0% +views and this is the top view. So then +the turbine rotates a little bit and + + align:start position:0% +the turbine rotates a little bit and + + + align:start position:0% +the turbine rotates a little bit and +then the weight balances out and so then + + align:start position:0% +then the weight balances out and so then + + + align:start position:0% +then the weight balances out and so then +the top engages again and then it + + align:start position:0% +the top engages again and then it + + + align:start position:0% +the top engages again and then it +maintains this angle of orientation and + + align:start position:0% +maintains this angle of orientation and + + + align:start position:0% +maintains this angle of orientation and +then if the wind speed gets even higher + + align:start position:0% +then if the wind speed gets even higher + + + align:start position:0% +then if the wind speed gets even higher +it will again the weights will get out + + align:start position:0% +it will again the weights will get out + + + align:start position:0% +it will again the weights will get out +of balance, things will lift, the stop + + align:start position:0% +of balance, things will lift, the stop + + + align:start position:0% +of balance, things will lift, the stop +will disengage. So it's a really cool + + align:start position:0% +will disengage. So it's a really cool + + + align:start position:0% +will disengage. So it's a really cool +system um to keep keep your device safe. + + align:start position:0% +system um to keep keep your device safe. + + + align:start position:0% +system um to keep keep your device safe. +Um, and there's a lot of a lot of them + + align:start position:0% +Um, and there's a lot of a lot of them + + + align:start position:0% +Um, and there's a lot of a lot of them +out there. Uh, and so + + align:start position:0% +out there. Uh, and so + + + align:start position:0% +out there. Uh, and so +I just wanted to show an example of what + + align:start position:0% +I just wanted to show an example of what + + + align:start position:0% +I just wanted to show an example of what +happens when you don't remember where's + + align:start position:0% +happens when you don't remember where's + + + align:start position:0% +happens when you don't remember where's +my mouse + + align:start position:0% +my mouse + + + align:start position:0% +my mouse +to include that or don't do it right. + + align:start position:0% +to include that or don't do it right. + + + align:start position:0% +to include that or don't do it right. +Um, so watch carefully. + + align:start position:0% + + + + align:start position:0% + +So, + + align:start position:0% +So, + + + align:start position:0% +So, +that was an expensive day and they're + + align:start position:0% +that was an expensive day and they're + + + align:start position:0% +that was an expensive day and they're +really lucky that no one um was under + + align:start position:0% +really lucky that no one um was under + + + align:start position:0% +really lucky that no one um was under +there. Um so, I'll put it back so you + + align:start position:0% +there. Um so, I'll put it back so you + + + align:start position:0% +there. Um so, I'll put it back so you +can watch it again. + + align:start position:0% +can watch it again. + + + align:start position:0% +can watch it again. +Can you see? Were you saying you + + align:start position:0% +Can you see? Were you saying you + + + align:start position:0% +Can you see? Were you saying you +couldn't see it? Just did you make it + + align:start position:0% +couldn't see it? Just did you make it + + + align:start position:0% +couldn't see it? Just did you make it +work or + + align:start position:0% +work or + + + align:start position:0% +work or +So, what + + align:start position:0% +So, what + + + align:start position:0% +So, what +did the blade just fall off? Like did it + + align:start position:0% +did the blade just fall off? Like did it + + + align:start position:0% +did the blade just fall off? Like did it +just like + + align:start position:0% +just like + + + align:start position:0% +just like +so it rotated so fast that I believe one + + align:start position:0% +so it rotated so fast that I believe one + + + align:start position:0% +so it rotated so fast that I believe one +of the blades broke off and then once + + align:start position:0% +of the blades broke off and then once + + + align:start position:0% +of the blades broke off and then once +one breaks it's totally out of balance + + align:start position:0% +one breaks it's totally out of balance + + + align:start position:0% +one breaks it's totally out of balance +and the whole thing just falls apart and + + align:start position:0% +and the whole thing just falls apart and + + + align:start position:0% +and the whole thing just falls apart and +it's moving at such fast speed that + + align:start position:0% +it's moving at such fast speed that + + + align:start position:0% +it's moving at such fast speed that +really crazy dynamics are going on. Um + + align:start position:0% +really crazy dynamics are going on. Um + + + align:start position:0% +really crazy dynamics are going on. Um +so yeah, so there's really solid reasons + + align:start position:0% +so yeah, so there's really solid reasons + + + align:start position:0% +so yeah, so there's really solid reasons +to design these, right? Um especially + + align:start position:0% +to design these, right? Um especially + + + align:start position:0% +to design these, right? Um especially +when you're talking big scale, but even + + align:start position:0% +when you're talking big scale, but even + + + align:start position:0% +when you're talking big scale, but even +small scale. Um you can imagine in a + + align:start position:0% +small scale. Um you can imagine in a + + + align:start position:0% +small scale. Um you can imagine in a +hurricane it's not going to be a safe + + align:start position:0% +hurricane it's not going to be a safe + + + align:start position:0% +hurricane it's not going to be a safe +thing to be near. Um and the small ones + + align:start position:0% +thing to be near. Um and the small ones + + + align:start position:0% +thing to be near. Um and the small ones +are often + + align:start position:0% +are often + + + align:start position:0% +are often +near people. + + align:start position:0% + + + + align:start position:0% + +Okay. So the typical components + + align:start position:0% +Okay. So the typical components + + + align:start position:0% +Okay. So the typical components +of a wind turbine, you have your rotor, + + align:start position:0% +of a wind turbine, you have your rotor, + + + align:start position:0% +of a wind turbine, you have your rotor, +you have your blades, + + align:start position:0% +you have your blades, + + + align:start position:0% +you have your blades, +you have a brake um because you want the + + align:start position:0% +you have a brake um because you want the + + + align:start position:0% +you have a brake um because you want the +turbine to be turning at a certain speed + + align:start position:0% +turbine to be turning at a certain speed + + + align:start position:0% +turbine to be turning at a certain speed +ideally and so you may need to break + + align:start position:0% +ideally and so you may need to break + + + align:start position:0% +ideally and so you may need to break +provide braking before you're providing + + align:start position:0% +provide braking before you're providing + + + align:start position:0% +provide braking before you're providing +rotation out of the wind. That's another + + align:start position:0% +rotation out of the wind. That's another + + + align:start position:0% +rotation out of the wind. That's another +you know smaller step you can take. Um, + + align:start position:0% +you know smaller step you can take. Um, + + + align:start position:0% +you know smaller step you can take. Um, +you have a gear box to get the speed to + + align:start position:0% +you have a gear box to get the speed to + + + align:start position:0% +you have a gear box to get the speed to +the right speed to power your generator. + + align:start position:0% +the right speed to power your generator. + + + align:start position:0% +the right speed to power your generator. +Um, typically on a fancier wind turbine, + + align:start position:0% +Um, typically on a fancier wind turbine, + + + align:start position:0% +Um, typically on a fancier wind turbine, +there's an anometer that provides the + + align:start position:0% +there's an anometer that provides the + + + align:start position:0% +there's an anometer that provides the +electrical control with these yaw drives + + align:start position:0% +electrical control with these yaw drives + + + align:start position:0% +electrical control with these yaw drives +and motors to rotate the um, turbine + + align:start position:0% +and motors to rotate the um, turbine + + + align:start position:0% +and motors to rotate the um, turbine +into the wind or out of the wind to + + align:start position:0% +into the wind or out of the wind to + + + align:start position:0% +into the wind or out of the wind to +maximize uh, the speed of your turbine + + align:start position:0% +maximize uh, the speed of your turbine + + + align:start position:0% +maximize uh, the speed of your turbine +and then your tower. And then so all the + + align:start position:0% +and then your tower. And then so all the + + + align:start position:0% +and then your tower. And then so all the +uh electricity is being generated in + + align:start position:0% +uh electricity is being generated in + + + align:start position:0% +uh electricity is being generated in +this part of the body and then the power + + align:start position:0% +this part of the body and then the power + + + align:start position:0% +this part of the body and then the power +is just going down the um the tower and + + align:start position:0% +is just going down the um the tower and + + + align:start position:0% +is just going down the um the tower and +you can imagine the challenge of when + + align:start position:0% +you can imagine the challenge of when + + + align:start position:0% +you can imagine the challenge of when +you need to do maintenance on this and + + align:start position:0% +you need to do maintenance on this and + + + align:start position:0% +you need to do maintenance on this and +you're talking about something really + + align:start position:0% +you're talking about something really + + + align:start position:0% +you're talking about something really +high up that you have to deal with it. + + align:start position:0% +high up that you have to deal with it. + + + align:start position:0% +high up that you have to deal with it. +So, the smaller turbine or turbines that + + align:start position:0% +So, the smaller turbine or turbines that + + + align:start position:0% +So, the smaller turbine or turbines that +we'll be looking at, they're all on + + align:start position:0% +we'll be looking at, they're all on + + + align:start position:0% +we'll be looking at, they're all on +guide wires and on a pivot so that you + + align:start position:0% +guide wires and on a pivot so that you + + + align:start position:0% +guide wires and on a pivot so that you +can rotate them down so you don't have + + align:start position:0% +can rotate them down so you don't have + + + align:start position:0% +can rotate them down so you don't have +to climb up to do maintenance because + + align:start position:0% +to climb up to do maintenance because + + + align:start position:0% +to climb up to do maintenance because +that requires a much sturdier tower and + + align:start position:0% +that requires a much sturdier tower and + + + align:start position:0% +that requires a much sturdier tower and +is a much more dangerous job. + + align:start position:0% +is a much more dangerous job. + + + align:start position:0% +is a much more dangerous job. +Um, some installation considerations + + align:start position:0% +Um, some installation considerations + + + align:start position:0% +Um, some installation considerations +that one would think would be obvious + + align:start position:0% +that one would think would be obvious + + + align:start position:0% +that one would think would be obvious +but aren't always. So, this is a a wind + + align:start position:0% +but aren't always. So, this is a a wind + + + align:start position:0% +but aren't always. So, this is a a wind +turbine that's been installed basically + + align:start position:0% +turbine that's been installed basically + + + align:start position:0% +turbine that's been installed basically +on a rooftop um by some trees. So, it's + + align:start position:0% +on a rooftop um by some trees. So, it's + + + align:start position:0% +on a rooftop um by some trees. So, it's +got two types of uh + + align:start position:0% +got two types of uh + + + align:start position:0% +got two types of uh +objects that are blocking the wind + + align:start position:0% +objects that are blocking the wind + + + align:start position:0% +objects that are blocking the wind +entirely. So, this, you know, was a many + + align:start position:0% +entirely. So, this, you know, was a many + + + align:start position:0% +entirely. So, this, you know, was a many +thousand installation that's probably + + align:start position:0% +thousand installation that's probably + + + align:start position:0% +thousand installation that's probably +providing zero electricity because it + + align:start position:0% +providing zero electricity because it + + + align:start position:0% +providing zero electricity because it +the wind may be sufficient 30 meters up, + + align:start position:0% +the wind may be sufficient 30 meters up, + + + align:start position:0% +the wind may be sufficient 30 meters up, +but right there is never going to be + + align:start position:0% +but right there is never going to be + + + align:start position:0% +but right there is never going to be +sufficient. Um, so the good 30 meters, + + align:start position:0% +sufficient. Um, so the good 30 meters, + + + align:start position:0% +sufficient. Um, so the good 30 meters, +30 feet. Um, a good rule of thumb is you + + align:start position:0% +30 feet. Um, a good rule of thumb is you + + + align:start position:0% +30 feet. Um, a good rule of thumb is you +want your turbine to be 30 feet above + + align:start position:0% +want your turbine to be 30 feet above + + + align:start position:0% +want your turbine to be 30 feet above +any obstruction within 300 ft. Um, and + + align:start position:0% +any obstruction within 300 ft. Um, and + + + align:start position:0% +any obstruction within 300 ft. Um, and +so obstructions include like houses and + + align:start position:0% +so obstructions include like houses and + + + align:start position:0% +so obstructions include like houses and +plants and anything else that might be + + align:start position:0% +plants and anything else that might be + + + align:start position:0% +plants and anything else that might be +in the way. So, next up is vertical + + align:start position:0% +in the way. So, next up is vertical + + + align:start position:0% +in the way. So, next up is vertical +access wind turbines. And you can see + + align:start position:0% +access wind turbines. And you can see + + + align:start position:0% +access wind turbines. And you can see +there's a huge range of them. Um, and + + align:start position:0% +there's a huge range of them. Um, and + + + align:start position:0% +there's a huge range of them. Um, and +you probably haven't seen most of these + + align:start position:0% +you probably haven't seen most of these + + + align:start position:0% +you probably haven't seen most of these +in production because again, they're + + align:start position:0% +in production because again, they're + + + align:start position:0% +in production because again, they're +they're not um + + align:start position:0% +they're not um + + + align:start position:0% +they're not um +they don't have the same level of + + align:start position:0% +they don't have the same level of + + + align:start position:0% +they don't have the same level of +efficiencies and benefits that um + + align:start position:0% +efficiencies and benefits that um + + + align:start position:0% +efficiencies and benefits that um +horizontal axis wind turbines have, but + + align:start position:0% +horizontal axis wind turbines have, but + + + align:start position:0% +horizontal axis wind turbines have, but +they're a whole lot cheaper and easier + + align:start position:0% +they're a whole lot cheaper and easier + + + align:start position:0% +they're a whole lot cheaper and easier +to build. So, for small scale solutions, + + align:start position:0% +to build. So, for small scale solutions, + + + align:start position:0% +to build. So, for small scale solutions, +they're they can be really ideal. + + align:start position:0% +they're they can be really ideal. + + + align:start position:0% +they're they can be really ideal. +There's a bunch of different names of + + align:start position:0% +There's a bunch of different names of + + + align:start position:0% +There's a bunch of different names of +these different types. So, for example, + + align:start position:0% +these different types. So, for example, + + + align:start position:0% +these different types. So, for example, +this is called a Darius wind turbine. + + align:start position:0% +this is called a Darius wind turbine. + + + align:start position:0% +this is called a Darius wind turbine. +This is a Savonius wind turbine, which + + align:start position:0% +This is a Savonius wind turbine, which + + + align:start position:0% +This is a Savonius wind turbine, which +you'll be building on Friday. Um, and + + align:start position:0% +you'll be building on Friday. Um, and + + + align:start position:0% +you'll be building on Friday. Um, and +this is a cool combo. Savonius, Darius. + + align:start position:0% +this is a cool combo. Savonius, Darius. + + + align:start position:0% +this is a cool combo. Savonius, Darius. +Um, this the Savonius will start up + + align:start position:0% +Um, this the Savonius will start up + + + align:start position:0% +Um, this the Savonius will start up +automatically in wind and the Darius + + align:start position:0% +automatically in wind and the Darius + + + align:start position:0% +automatically in wind and the Darius +won't, but the Darius gets a little bit + + align:start position:0% +won't, but the Darius gets a little bit + + + align:start position:0% +won't, but the Darius gets a little bit +better efficiency. So, the combining + + align:start position:0% +better efficiency. So, the combining + + + align:start position:0% +better efficiency. So, the combining +sort of gets gets you the best of both + + align:start position:0% +sort of gets gets you the best of both + + + align:start position:0% +sort of gets gets you the best of both +worlds with some drawbacks of course + + align:start position:0% +worlds with some drawbacks of course + + + align:start position:0% +worlds with some drawbacks of course +too. Um, and so these power traffic + + align:start position:0% +too. Um, and so these power traffic + + + align:start position:0% +too. Um, and so these power traffic +lights in Taiwan. Um, so there are + + align:start position:0% +lights in Taiwan. Um, so there are + + + align:start position:0% +lights in Taiwan. Um, so there are +places where these are installed + + align:start position:0% +places where these are installed + + + align:start position:0% +places where these are installed +effectively. Um, + + align:start position:0% +effectively. Um, + + + align:start position:0% +effectively. Um, +and they're kind of cool. Um because as + + align:start position:0% +and they're kind of cool. Um because as + + + align:start position:0% +and they're kind of cool. Um because as +you can see here + + align:start position:0% +you can see here + + + align:start position:0% +you can see here +um you can almost build them out of + + align:start position:0% +um you can almost build them out of + + + align:start position:0% +um you can almost build them out of +anything and you will build them out of + + align:start position:0% +anything and you will build them out of + + + align:start position:0% +anything and you will build them out of +anything on Friday. Hey Amit, do we have + + align:start position:0% +anything on Friday. Hey Amit, do we have + + + align:start position:0% +anything on Friday. Hey Amit, do we have +enough plastic bottles? Speaking of + + align:start position:0% +enough plastic bottles? Speaking of + + + align:start position:0% +enough plastic bottles? Speaking of +which, for Friday. + + align:start position:0% +which, for Friday. + + + align:start position:0% +which, for Friday. +So + + align:start position:0% +So + + + align:start position:0% +So +added to your homework is on Friday you + + align:start position:0% +added to your homework is on Friday you + + + align:start position:0% +added to your homework is on Friday you +need to bring in a plastic bottle like a + + align:start position:0% +need to bring in a plastic bottle like a + + + align:start position:0% +need to bring in a plastic bottle like a +Gatorade bottle, a 2 liter bottle, + + align:start position:0% +Gatorade bottle, a 2 liter bottle, + + + align:start position:0% +Gatorade bottle, a 2 liter bottle, +whatever. Um it doesn't it doesn't have + + align:start position:0% +whatever. Um it doesn't it doesn't have + + + align:start position:0% +whatever. Um it doesn't it doesn't have +to be two liters. It can be one liter or + + align:start position:0% +to be two liters. It can be one liter or + + + align:start position:0% +to be two liters. It can be one liter or +h you know like a 20 oz can uh bottle. + + align:start position:0% +h you know like a 20 oz can uh bottle. + + + align:start position:0% +h you know like a 20 oz can uh bottle. +But we need plastic bottles. If everyone + + align:start position:0% +But we need plastic bottles. If everyone + + + align:start position:0% +But we need plastic bottles. If everyone +bring brings one, we'll be in good + + align:start position:0% +bring brings one, we'll be in good + + + align:start position:0% +bring brings one, we'll be in good +shape. Is that doable? If you check the + + align:start position:0% +shape. Is that doable? If you check the + + + align:start position:0% +shape. Is that doable? If you check the +recycling bins walking to class, you'll + + align:start position:0% +recycling bins walking to class, you'll + + + align:start position:0% +recycling bins walking to class, you'll +find one. Um, cool. So, + + align:start position:0% +find one. Um, cool. So, + + + align:start position:0% +find one. Um, cool. So, +the some of the advantages, they're + + align:start position:0% +the some of the advantages, they're + + + align:start position:0% +the some of the advantages, they're +close to the ground, so you don't have + + align:start position:0% +close to the ground, so you don't have + + + align:start position:0% +close to the ground, so you don't have +any line losses um associ comparative to + + align:start position:0% +any line losses um associ comparative to + + + align:start position:0% +any line losses um associ comparative to +the horizontal axis wind turbine. Um, + + align:start position:0% +the horizontal axis wind turbine. Um, + + + align:start position:0% +the horizontal axis wind turbine. Um, +you don't need any yaw or pitch control + + align:start position:0% +you don't need any yaw or pitch control + + + align:start position:0% +you don't need any yaw or pitch control +because they're just in the wind. + + align:start position:0% +because they're just in the wind. + + + align:start position:0% +because they're just in the wind. +They're intended to be in the wind and + + align:start position:0% +They're intended to be in the wind and + + + align:start position:0% +They're intended to be in the wind and +that works. Um, so they work for and + + align:start position:0% +that works. Um, so they work for and + + + align:start position:0% +that works. Um, so they work for and +they work generally for lower wind + + align:start position:0% +they work generally for lower wind + + + align:start position:0% +they work generally for lower wind +speeds, which is means lower heights. + + align:start position:0% +speeds, which is means lower heights. + + + align:start position:0% +speeds, which is means lower heights. +They're often much less noisy than wind + + align:start position:0% +They're often much less noisy than wind + + + align:start position:0% +They're often much less noisy than wind +turbines, uh, horizontal axis wind + + align:start position:0% +turbines, uh, horizontal axis wind + + + align:start position:0% +turbines, uh, horizontal axis wind +turbines, and they can often start at + + align:start position:0% +turbines, and they can often start at + + + align:start position:0% +turbines, and they can often start at +lower speeds. Um, + + align:start position:0% +lower speeds. Um, + + + align:start position:0% +lower speeds. Um, +but some of the advantage disadvantages, + + align:start position:0% +but some of the advantage disadvantages, + + + align:start position:0% +but some of the advantage disadvantages, +they're hard to scale up. So you're + + align:start position:0% +they're hard to scale up. So you're + + + align:start position:0% +they're hard to scale up. So you're +never going to get a + + align:start position:0% +never going to get a + + + align:start position:0% +never going to get a +seven megawatt um, vertical axis wind + + align:start position:0% +seven megawatt um, vertical axis wind + + + align:start position:0% +seven megawatt um, vertical axis wind +turbine. that's just not viable. Um + + align:start position:0% +turbine. that's just not viable. Um + + + align:start position:0% +turbine. that's just not viable. Um +they're generally less efficient and + + align:start position:0% +they're generally less efficient and + + + align:start position:0% +they're generally less efficient and +they're more prone to fatigue. So they + + align:start position:0% +they're more prone to fatigue. So they + + + align:start position:0% +they're more prone to fatigue. So they +do wear out um more easily because + + align:start position:0% +do wear out um more easily because + + + align:start position:0% +do wear out um more easily because +they're capturing so much more of of the + + align:start position:0% +they're capturing so much more of of the + + + align:start position:0% +they're capturing so much more of of the +wind typically. Um but they um for our + + align:start position:0% +wind typically. Um but they um for our + + + align:start position:0% +wind typically. Um but they um for our +purposes they're definitely a + + align:start position:0% +purposes they're definitely a + + + align:start position:0% +purposes they're definitely a +possibility to look at um for anything. + + align:start position:0% +possibility to look at um for anything. + + + align:start position:0% +possibility to look at um for anything. +Just a reminder + + align:start position:0% +Just a reminder + + + align:start position:0% +Just a reminder +of + + align:start position:0% +of + + + align:start position:0% +of +the equations we're thinking about. So + + align:start position:0% +the equations we're thinking about. So + + + align:start position:0% +the equations we're thinking about. So +the force + + align:start position:0% +the force + + + align:start position:0% +the force +is um that you're receiving is + + align:start position:0% +is um that you're receiving is + + + align:start position:0% +is um that you're receiving is +equivalent to uh 12 * row a v ^ 2. So v + + align:start position:0% +equivalent to uh 12 * row a v ^ 2. So v + + + align:start position:0% +equivalent to uh 12 * row a v ^ 2. So v +is obviously the velocity of the wind, + + align:start position:0% +is obviously the velocity of the wind, + + + align:start position:0% +is obviously the velocity of the wind, +the crosssectional area swept and the + + align:start position:0% +the crosssectional area swept and the + + + align:start position:0% +the crosssectional area swept and the +density of the wind. um + + align:start position:0% +density of the wind. um + + + align:start position:0% +density of the wind. um +the maximum possible + + align:start position:0% +the maximum possible + + + align:start position:0% +the maximum possible +power extraction + + align:start position:0% +power extraction + + + align:start position:0% +power extraction +uh is + + align:start position:0% +uh is + + + align:start position:0% +uh is +uh def dominated by the velocity cubed. + + align:start position:0% +uh def dominated by the velocity cubed. + + + align:start position:0% +uh def dominated by the velocity cubed. +So obviously velocity is going to be you + + align:start position:0% +So obviously velocity is going to be you + + + align:start position:0% +So obviously velocity is going to be you +velocity is really going to be what you + + align:start position:0% +velocity is really going to be what you + + + align:start position:0% +velocity is really going to be what you +worry about when you're designing. Um so + + align:start position:0% +worry about when you're designing. Um so + + + align:start position:0% +worry about when you're designing. Um so +area is important obviously but the cube + + align:start position:0% +area is important obviously but the cube + + + align:start position:0% +area is important obviously but the cube +velocity velocity is cubed so the wind + + align:start position:0% +velocity velocity is cubed so the wind + + + align:start position:0% +velocity velocity is cubed so the wind +speed is huge. Um so whenever you're + + align:start position:0% +speed is huge. Um so whenever you're + + + align:start position:0% +speed is huge. Um so whenever you're +thinking is this a place where the veloc + + align:start position:0% +thinking is this a place where the veloc + + + align:start position:0% +thinking is this a place where the veloc +where is a wind turbine appropriate the + + align:start position:0% +where is a wind turbine appropriate the + + + align:start position:0% +where is a wind turbine appropriate the +first question is well what's the wind + + align:start position:0% +first question is well what's the wind + + + align:start position:0% +first question is well what's the wind +speed? Um and then there's a coefficient + + align:start position:0% +speed? Um and then there's a coefficient + + + align:start position:0% +speed? Um and then there's a coefficient +of performance which just um + + align:start position:0% +of performance which just um + + + align:start position:0% +of performance which just um +is a reality that um wind turbines are + + align:start position:0% +is a reality that um wind turbines are + + + align:start position:0% +is a reality that um wind turbines are +not perfect. Um and so there's a + + align:start position:0% +not perfect. Um and so there's a + + + align:start position:0% +not perfect. Um and so there's a +hypothetical limit and you if you Google + + align:start position:0% +hypothetical limit and you if you Google + + + align:start position:0% +hypothetical limit and you if you Google +the bets limit you can find the proof if + + align:start position:0% +the bets limit you can find the proof if + + + align:start position:0% +the bets limit you can find the proof if +uh that's appealing. It's kind of cool. + + align:start position:0% +uh that's appealing. It's kind of cool. + + + align:start position:0% +uh that's appealing. It's kind of cool. +um of point almost 6 is your + + align:start position:0% +um of point almost 6 is your + + + align:start position:0% +um of point almost 6 is your +hypothetical maximum efficiency. And + + align:start position:0% +hypothetical maximum efficiency. And + + + align:start position:0% +hypothetical maximum efficiency. And +then a typical limit in reality is + + align:start position:0% +then a typical limit in reality is + + + align:start position:0% +then a typical limit in reality is +anywhere from a half for a really sweet + + align:start position:0% +anywhere from a half for a really sweet + + + align:start position:0% +anywhere from a half for a really sweet +horizontal axis wind turbine to less + + align:start position:0% +horizontal axis wind turbine to less + + + align:start position:0% +horizontal axis wind turbine to less +than um a tenth for um a a vertical axis + + align:start position:0% +than um a tenth for um a a vertical axis + + + align:start position:0% +than um a tenth for um a a vertical axis +wind turbine that um I'll show you + + align:start position:0% +wind turbine that um I'll show you + + + align:start position:0% +wind turbine that um I'll show you +later. That's really old school um but + + align:start position:0% +later. That's really old school um but + + + align:start position:0% +later. That's really old school um but +does the job when you need it. + + align:start position:0% +does the job when you need it. + + + align:start position:0% +does the job when you need it. +Um, so the other equation that you want + + align:start position:0% +Um, so the other equation that you want + + + align:start position:0% +Um, so the other equation that you want +to think about is the capacity factor. + + align:start position:0% +to think about is the capacity factor. + + + align:start position:0% +to think about is the capacity factor. +So I've seen some websites that say + + align:start position:0% +So I've seen some websites that say + + + align:start position:0% +So I've seen some websites that say +like, you know, wind is so much better + + align:start position:0% +like, you know, wind is so much better + + + align:start position:0% +like, you know, wind is so much better +than solar because wind is 24/7. Well, + + align:start position:0% +than solar because wind is 24/7. Well, + + + align:start position:0% +than solar because wind is 24/7. Well, +not really. Like unless you're getting + + align:start position:0% +not really. Like unless you're getting + + + align:start position:0% +not really. Like unless you're getting +up way into the atmosphere and even then + + align:start position:0% +up way into the atmosphere and even then + + + align:start position:0% +up way into the atmosphere and even then +there's a lot of variation. You're not + + align:start position:0% +there's a lot of variation. You're not + + + align:start position:0% +there's a lot of variation. You're not +wind is not 247. There's a tremendous + + align:start position:0% +wind is not 247. There's a tremendous + + + align:start position:0% +wind is not 247. There's a tremendous +amount of variation. And so it's + + align:start position:0% +amount of variation. And so it's + + + align:start position:0% +amount of variation. And so it's +generally 20 to 40% of the time is how + + align:start position:0% +generally 20 to 40% of the time is how + + + align:start position:0% +generally 20 to 40% of the time is how +often your turbine is um provide + + align:start position:0% +often your turbine is um provide + + + align:start position:0% +often your turbine is um provide +generating power which is sounding + + align:start position:0% +generating power which is sounding + + + align:start position:0% +generating power which is sounding +starting to sound more like solar + + align:start position:0% +starting to sound more like solar + + + align:start position:0% +starting to sound more like solar +actually. Um so that's one thing to + + align:start position:0% +actually. Um so that's one thing to + + + align:start position:0% +actually. Um so that's one thing to +definitely keep in mind. + + align:start position:0% +definitely keep in mind. + + + align:start position:0% +definitely keep in mind. +Um + + align:start position:0% +Um + + + align:start position:0% +Um +okay. So a typical C power curve. So at + + align:start position:0% +okay. So a typical C power curve. So at + + + align:start position:0% +okay. So a typical C power curve. So at +some point at some given speed um is + + align:start position:0% +some point at some given speed um is + + + align:start position:0% +some point at some given speed um is +when the turbine starts actually turning + + align:start position:0% +when the turbine starts actually turning + + + align:start position:0% +when the turbine starts actually turning +because up until then it can't + + align:start position:0% +because up until then it can't + + + align:start position:0% +because up until then it can't +physically turn because the wind forces + + align:start position:0% +physically turn because the wind forces + + + align:start position:0% +physically turn because the wind forces +aren't high enough. And then your output + + align:start position:0% +aren't high enough. And then your output + + + align:start position:0% +aren't high enough. And then your output +in terms of uh power is very very low. + + align:start position:0% +in terms of uh power is very very low. + + + align:start position:0% +in terms of uh power is very very low. +And then you have an average wind speeds + + align:start position:0% +And then you have an average wind speeds + + + align:start position:0% +And then you have an average wind speeds +generally somewhere around here which is + + align:start position:0% +generally somewhere around here which is + + + align:start position:0% +generally somewhere around here which is +giving you half of the wind power or the + + align:start position:0% +giving you half of the wind power or the + + + align:start position:0% +giving you half of the wind power or the +power that you'd like. And then you have + + align:start position:0% +power that you'd like. And then you have + + + align:start position:0% +power that you'd like. And then you have +a maximum wind speed and then you're + + align:start position:0% +a maximum wind speed and then you're + + + align:start position:0% +a maximum wind speed and then you're +happy happy happy and then at some point + + align:start position:0% +happy happy happy and then at some point + + + align:start position:0% +happy happy happy and then at some point +it gets so high that you have to shut + + align:start position:0% +it gets so high that you have to shut + + + align:start position:0% +it gets so high that you have to shut +the turbine down or else you're in + + align:start position:0% +the turbine down or else you're in + + + align:start position:0% +the turbine down or else you're in +trouble. So, um, + + align:start position:0% +trouble. So, um, + + + align:start position:0% +trouble. So, um, +that's just a a good general way to + + align:start position:0% +that's just a a good general way to + + + align:start position:0% +that's just a a good general way to +think about what's happening over + + align:start position:0% +think about what's happening over + + + align:start position:0% +think about what's happening over +different speeds because you're I'll + + align:start position:0% +different speeds because you're I'll + + + align:start position:0% +different speeds because you're I'll +show you later. We're going to look at + + align:start position:0% +show you later. We're going to look at + + + align:start position:0% +show you later. We're going to look at +data that shows you the different, um, + + align:start position:0% +data that shows you the different, um, + + + align:start position:0% +data that shows you the different, um, +speeds. + + align:start position:0% +speeds. + + + align:start position:0% +speeds. +So, uh, + + align:start position:0% +So, uh, + + + align:start position:0% +So, uh, +these are, uh, maps from NASA that show + + align:start position:0% +these are, uh, maps from NASA that show + + + align:start position:0% +these are, uh, maps from NASA that show +wind speed across the entire globe. Um, + + align:start position:0% +wind speed across the entire globe. Um, + + + align:start position:0% +wind speed across the entire globe. Um, +and you can see if it's um very dark, + + align:start position:0% +and you can see if it's um very dark, + + + align:start position:0% +and you can see if it's um very dark, +it's very low wind speed. And if it's + + align:start position:0% +it's very low wind speed. And if it's + + + align:start position:0% +it's very low wind speed. And if it's +very light, it's higher wind speed. Um, + + align:start position:0% +very light, it's higher wind speed. Um, + + + align:start position:0% +very light, it's higher wind speed. Um, +so if we could just fill this part of + + align:start position:0% +so if we could just fill this part of + + + align:start position:0% +so if we could just fill this part of +the ocean with wind turbines, that would + + align:start position:0% +the ocean with wind turbines, that would + + + align:start position:0% +the ocean with wind turbines, that would +be pretty sweet. But you can actually + + align:start position:0% +be pretty sweet. But you can actually + + + align:start position:0% +be pretty sweet. But you can actually +see um in Nicaragua, which is right over + + align:start position:0% +see um in Nicaragua, which is right over + + + align:start position:0% +see um in Nicaragua, which is right over +here, um you're getting pretty decent + + align:start position:0% +here, um you're getting pretty decent + + + align:start position:0% +here, um you're getting pretty decent +wind um compared to say if we were + + align:start position:0% +wind um compared to say if we were + + + align:start position:0% +wind um compared to say if we were +working in um these parts of Africa or + + align:start position:0% +working in um these parts of Africa or + + + align:start position:0% +working in um these parts of Africa or +up up here in Russia or something. we we + + align:start position:0% +up up here in Russia or something. we we + + + align:start position:0% +up up here in Russia or something. we we +wouldn't be thinking win turbines at + + align:start position:0% +wouldn't be thinking win turbines at + + + align:start position:0% +wouldn't be thinking win turbines at +all. Um, and you can see how much + + align:start position:0% +all. Um, and you can see how much + + + align:start position:0% +all. Um, and you can see how much +variation there is between January and + + align:start position:0% +variation there is between January and + + + align:start position:0% +variation there is between January and +July. And so, of course, there's a lot + + align:start position:0% +July. And so, of course, there's a lot + + + align:start position:0% +July. And so, of course, there's a lot +of seasonal variation no matter what. + + align:start position:0% +of seasonal variation no matter what. + + + align:start position:0% +of seasonal variation no matter what. +Um, and you can see like this blue is 7 + + align:start position:0% +Um, and you can see like this blue is 7 + + + align:start position:0% +Um, and you can see like this blue is 7 +meters/s, which is getting to be useful. + + align:start position:0% +meters/s, which is getting to be useful. + + + align:start position:0% +meters/s, which is getting to be useful. +Um, for horizontal axis wind turbine, + + align:start position:0% +Um, for horizontal axis wind turbine, + + + align:start position:0% +Um, for horizontal axis wind turbine, +you need 5 meters/s. Um, for vertical, + + align:start position:0% +you need 5 meters/s. Um, for vertical, + + + align:start position:0% +you need 5 meters/s. Um, for vertical, +you can go a little bit lower, but five + + align:start position:0% +you can go a little bit lower, but five + + + align:start position:0% +you can go a little bit lower, but five +is a good rule of thumb. + + align:start position:0% +is a good rule of thumb. + + + align:start position:0% +is a good rule of thumb. +Um, and again, why we're looking at + + align:start position:0% +Um, and again, why we're looking at + + + align:start position:0% +Um, and again, why we're looking at +velocity over everything else is because + + align:start position:0% +velocity over everything else is because + + + align:start position:0% +velocity over everything else is because +velocity is cubed for your power + + align:start position:0% +velocity is cubed for your power + + + align:start position:0% +velocity is cubed for your power +equation. + + align:start position:0% +equation. + + + align:start position:0% +equation. +So, great, I've told you wind speeds. + + align:start position:0% +So, great, I've told you wind speeds. + + + align:start position:0% +So, great, I've told you wind speeds. +I've showed you a NASA map of the entire + + align:start position:0% +I've showed you a NASA map of the entire + + + align:start position:0% +I've showed you a NASA map of the entire +Earth, but that doesn't tell you much + + align:start position:0% +Earth, but that doesn't tell you much + + + align:start position:0% +Earth, but that doesn't tell you much +for a given location. So, one way to get + + align:start position:0% +for a given location. So, one way to get + + + align:start position:0% +for a given location. So, one way to get +a really rough estimate of wind speed is + + align:start position:0% +a really rough estimate of wind speed is + + + align:start position:0% +a really rough estimate of wind speed is +this Bowford scale, which was developed + + align:start position:0% +this Bowford scale, which was developed + + + align:start position:0% +this Bowford scale, which was developed +in the 1800s. Um, and it correlates what + + align:start position:0% +in the 1800s. Um, and it correlates what + + + align:start position:0% +in the 1800s. Um, and it correlates what +you can visually see and what kind of + + align:start position:0% +you can visually see and what kind of + + + align:start position:0% +you can visually see and what kind of +damage you're seeing to the speed. Some + + align:start position:0% +damage you're seeing to the speed. Some + + + align:start position:0% +damage you're seeing to the speed. Some +of the caveats on this are number one, + + align:start position:0% +of the caveats on this are number one, + + + align:start position:0% +of the caveats on this are number one, +it's pretty rough. Um, and especially if + + align:start position:0% +it's pretty rough. Um, and especially if + + + align:start position:0% +it's pretty rough. Um, and especially if +you're talking to people in a community + + align:start position:0% +you're talking to people in a community + + + align:start position:0% +you're talking to people in a community +saying like, you know, tell me about + + align:start position:0% +saying like, you know, tell me about + + + align:start position:0% +saying like, you know, tell me about +wind speed and giving them examples. + + align:start position:0% +wind speed and giving them examples. + + + align:start position:0% +wind speed and giving them examples. +It's hard to remember exactly what the + + align:start position:0% +It's hard to remember exactly what the + + + align:start position:0% +It's hard to remember exactly what the +wind is like. Like, can you tell me what + + align:start position:0% +wind is like. Like, can you tell me what + + + align:start position:0% +wind is like. Like, can you tell me what +the Bowford scale was today walking + + align:start position:0% +the Bowford scale was today walking + + + align:start position:0% +the Bowford scale was today walking +here? + + align:start position:0% +here? + + + align:start position:0% +here? +I can't like I don't remember. I don't + + align:start position:0% +I can't like I don't remember. I don't + + + align:start position:0% +I can't like I don't remember. I don't +really pay attention to the wind that + + align:start position:0% +really pay attention to the wind that + + + align:start position:0% +really pay attention to the wind that +much. Um, if you're working with + + align:start position:0% +much. Um, if you're working with + + + align:start position:0% +much. Um, if you're working with +farmers, they're probably a little bit + + align:start position:0% +farmers, they're probably a little bit + + + align:start position:0% +farmers, they're probably a little bit +more aware of it than you and I might + + align:start position:0% +more aware of it than you and I might + + + align:start position:0% +more aware of it than you and I might +be, but still, um, it's challenging. And + + align:start position:0% +be, but still, um, it's challenging. And + + + align:start position:0% +be, but still, um, it's challenging. And +the other thing is that a lot of these + + align:start position:0% +the other thing is that a lot of these + + + align:start position:0% +the other thing is that a lot of these +metrics are on the ground and we're + + align:start position:0% +metrics are on the ground and we're + + + align:start position:0% +metrics are on the ground and we're +probably talking about significantly + + align:start position:0% +probably talking about significantly + + + align:start position:0% +probably talking about significantly +higher than the ground depending on what + + align:start position:0% +higher than the ground depending on what + + + align:start position:0% +higher than the ground depending on what +kind of turbine you're implementing. And + + align:start position:0% +kind of turbine you're implementing. And + + + align:start position:0% +kind of turbine you're implementing. And +so again, that that only helps you. So, + + align:start position:0% +so again, that that only helps you. So, + + + align:start position:0% +so again, that that only helps you. So, +if you're finding out that you're + + align:start position:0% +if you're finding out that you're + + + align:start position:0% +if you're finding out that you're +probably at um 4 m an hour, which is 2 + + align:start position:0% +probably at um 4 m an hour, which is 2 + + + align:start position:0% +probably at um 4 m an hour, which is 2 +m/s and really low, but at the very + + align:start position:0% +m/s and really low, but at the very + + + align:start position:0% +m/s and really low, but at the very +ground level and you're building a + + align:start position:0% +ground level and you're building a + + + align:start position:0% +ground level and you're building a +turbine that's 30 m up, maybe uh 30 ft + + align:start position:0% +turbine that's 30 m up, maybe uh 30 ft + + + align:start position:0% +turbine that's 30 m up, maybe uh 30 ft +up, maybe you have a shot um of getting + + align:start position:0% +up, maybe you have a shot um of getting + + + align:start position:0% +up, maybe you have a shot um of getting +enough wind. Yeah. + + align:start position:0% +enough wind. Yeah. + + + align:start position:0% +enough wind. Yeah. +Is there like a uniform um scale from + + align:start position:0% +Is there like a uniform um scale from + + + align:start position:0% +Is there like a uniform um scale from +like what the wind speed at the ground + + align:start position:0% +like what the wind speed at the ground + + + align:start position:0% +like what the wind speed at the ground +level is and then how how it changes + + align:start position:0% +level is and then how how it changes + + + align:start position:0% +level is and then how how it changes +vertically? + + align:start position:0% +vertically? + + + align:start position:0% +vertically? +So, or is that a regional thing? What's + + align:start position:0% +So, or is that a regional thing? What's + + + align:start position:0% +So, or is that a regional thing? What's +up? Well, so it's both. So, yes, there + + align:start position:0% +up? Well, so it's both. So, yes, there + + + align:start position:0% +up? Well, so it's both. So, yes, there +are some scales that can help you + + align:start position:0% +are some scales that can help you + + + align:start position:0% +are some scales that can help you +estimate if you know what the ground is, + + align:start position:0% +estimate if you know what the ground is, + + + align:start position:0% +estimate if you know what the ground is, +what it is up above, but it also is + + align:start position:0% +what it is up above, but it also is + + + align:start position:0% +what it is up above, but it also is +really dependent on what's around. And + + align:start position:0% +really dependent on what's around. And + + + align:start position:0% +really dependent on what's around. And +so, I'm about to show you a tool that + + align:start position:0% +so, I'm about to show you a tool that + + + align:start position:0% +so, I'm about to show you a tool that +helps a little bit with that, but it's + + align:start position:0% +helps a little bit with that, but it's + + + align:start position:0% +helps a little bit with that, but it's +still very imperfect. Um, ideally you'd + + align:start position:0% +still very imperfect. Um, ideally you'd + + + align:start position:0% +still very imperfect. Um, ideally you'd +have an animometer and you leave it up + + align:start position:0% +have an animometer and you leave it up + + + align:start position:0% +have an animometer and you leave it up +for five years and you'd have it at, you + + align:start position:0% +for five years and you'd have it at, you + + + align:start position:0% +for five years and you'd have it at, you +know, 10 different heights, you know, 10 + + align:start position:0% +know, 10 different heights, you know, 10 + + + align:start position:0% +know, 10 different heights, you know, 10 +different anominers, 10 different + + align:start position:0% +different anominers, 10 different + + + align:start position:0% +different anominers, 10 different +heights and that would get you actual + + align:start position:0% +heights and that would get you actual + + + align:start position:0% +heights and that would get you actual +real data that you'd be psyched for. But + + align:start position:0% +real data that you'd be psyched for. But + + + align:start position:0% +real data that you'd be psyched for. But +that would be a really ridiculously slow + + align:start position:0% +that would be a really ridiculously slow + + + align:start position:0% +that would be a really ridiculously slow +expensive project. And so a lot of this + + align:start position:0% +expensive project. And so a lot of this + + + align:start position:0% +expensive project. And so a lot of this +is just estimations and doing your best + + align:start position:0% +is just estimations and doing your best + + + align:start position:0% +is just estimations and doing your best +guesses. Um, so this I'm sorry for the + + align:start position:0% +guesses. Um, so this I'm sorry for the + + + align:start position:0% +guesses. Um, so this I'm sorry for the +web link. As you'll see, this website is + + align:start position:0% +web link. As you'll see, this website is + + + align:start position:0% +web link. As you'll see, this website is +like web. It's not even web 1.0. It's + + align:start position:0% +like web. It's not even web 1.0. It's + + + align:start position:0% +like web. It's not even web 1.0. It's +like web 0.5, but it has like awesome + + align:start position:0% +like web 0.5, but it has like awesome + + + align:start position:0% +like web 0.5, but it has like awesome +data um from NASA. So, + + align:start position:0% +data um from NASA. So, + + + align:start position:0% +data um from NASA. So, +you go to this website with that awful + + align:start position:0% +you go to this website with that awful + + + align:start position:0% +you go to this website with that awful +link and then there's a bunch of + + align:start position:0% +link and then there's a bunch of + + + align:start position:0% +link and then there's a bunch of +different ways to get this data. And + + align:start position:0% +different ways to get this data. And + + + align:start position:0% +different ways to get this data. And +this is actually for both useful for + + align:start position:0% +this is actually for both useful for + + + align:start position:0% +this is actually for both useful for +solar and wind. So, if you're worrying + + align:start position:0% +solar and wind. So, if you're worrying + + + align:start position:0% +solar and wind. So, if you're worrying +about solar data, too, this is really + + align:start position:0% +about solar data, too, this is really + + + align:start position:0% +about solar data, too, this is really +useful. So, if you don't know where you + + align:start position:0% +useful. So, if you don't know where you + + + align:start position:0% +useful. So, if you don't know where you +want to, you don't know your latitude + + align:start position:0% +want to, you don't know your latitude + + + align:start position:0% +want to, you don't know your latitude +and longitude, you can click use a map + + align:start position:0% +and longitude, you can click use a map + + + align:start position:0% +and longitude, you can click use a map +to click. Um, every time you do this, + + align:start position:0% +to click. Um, every time you do this, + + + align:start position:0% +to click. Um, every time you do this, +you have to log in. Um, but there's it's + + align:start position:0% +you have to log in. Um, but there's it's + + + align:start position:0% +you have to log in. Um, but there's it's +very easy to um join because you just + + align:start position:0% +very easy to um join because you just + + + align:start position:0% +very easy to um join because you just +type your password twice instead of once + + align:start position:0% +type your password twice instead of once + + + align:start position:0% +type your password twice instead of once +once you become a member. Um, + + align:start position:0% + + + + align:start position:0% + +and then it's slow, but uh it's it looks + + align:start position:0% +and then it's slow, but uh it's it looks + + + align:start position:0% +and then it's slow, but uh it's it looks +so clunky that I was afraid you'd be + + align:start position:0% +so clunky that I was afraid you'd be + + + align:start position:0% +so clunky that I was afraid you'd be +turned off by it. And it has good enough + + align:start position:0% +turned off by it. And it has good enough + + + align:start position:0% +turned off by it. And it has good enough +data that I wanted to go through showing + + align:start position:0% +data that I wanted to go through showing + + + align:start position:0% +data that I wanted to go through showing +you um it. So, you have this map of the + + align:start position:0% +you um it. So, you have this map of the + + + align:start position:0% +you um it. So, you have this map of the +Earth. You click in the part of the + + align:start position:0% +Earth. You click in the part of the + + + align:start position:0% +Earth. You click in the part of the +Earth that you care about to center it. + + align:start position:0% +Earth that you care about to center it. + + + align:start position:0% +Earth that you care about to center it. +You click to zoom. + + align:start position:0% +You click to zoom. + + + align:start position:0% +You click to zoom. +Um, we're in the wrong part of the + + align:start position:0% +Um, we're in the wrong part of the + + + align:start position:0% +Um, we're in the wrong part of the +world, but we're getting there. + + align:start position:0% +world, but we're getting there. + + + align:start position:0% +world, but we're getting there. +Uh, I'm going to zoom in again. + + align:start position:0% + + + + align:start position:0% + +All right. And you can see like this is + + align:start position:0% +All right. And you can see like this is + + + align:start position:0% +All right. And you can see like this is +data for a region, not for a small town. + + align:start position:0% +data for a region, not for a small town. + + + align:start position:0% +data for a region, not for a small town. +So there's all sorts of limits to this + + align:start position:0% +So there's all sorts of limits to this + + + align:start position:0% +So there's all sorts of limits to this +data, but it's useful. And so now you + + align:start position:0% +data, but it's useful. And so now you + + + align:start position:0% +data, but it's useful. And so now you +can finally get your data and now you + + align:start position:0% +can finally get your data and now you + + + align:start position:0% +can finally get your data and now you +can get crazy information. So parameters + + align:start position:0% +can get crazy information. So parameters + + + align:start position:0% +can get crazy information. So parameters +for solar cooking, for solar panels, um + + align:start position:0% +for solar cooking, for solar panels, um + + + align:start position:0% +for solar cooking, for solar panels, um +cloud information, which can be really + + align:start position:0% +cloud information, which can be really + + + align:start position:0% +cloud information, which can be really +useful, temperature, which can be really + + align:start position:0% +useful, temperature, which can be really + + + align:start position:0% +useful, temperature, which can be really +useful. Um and now we're getting to + + align:start position:0% +useful. Um and now we're getting to + + + align:start position:0% +useful. Um and now we're getting to +wind. So you can see the variety. So you + + align:start position:0% +wind. So you can see the variety. So you + + + align:start position:0% +wind. So you can see the variety. So you +can get 50 meter and 10 meter but + + align:start position:0% +can get 50 meter and 10 meter but + + + align:start position:0% +can get 50 meter and 10 meter but +because this is all satellite data or + + align:start position:0% +because this is all satellite data or + + + align:start position:0% +because this is all satellite data or +airport data. Um so 50 m is pretty high + + align:start position:0% +airport data. Um so 50 m is pretty high + + + align:start position:0% +airport data. Um so 50 m is pretty high +for anything we're talking about and + + align:start position:0% +for anything we're talking about and + + + align:start position:0% +for anything we're talking about and +then 10 m for terrain similar to the + + align:start position:0% +then 10 m for terrain similar to the + + + align:start position:0% +then 10 m for terrain similar to the +airport because they're measuring at the + + align:start position:0% +airport because they're measuring at the + + + align:start position:0% +airport because they're measuring at the +airport because that's the place where + + align:start position:0% +airport because that's the place where + + + align:start position:0% +airport because that's the place where +they have an animomer. So all of this + + align:start position:0% +they have an animomer. So all of this + + + align:start position:0% +they have an animomer. So all of this +data you again you have to take with a + + align:start position:0% +data you again you have to take with a + + + align:start position:0% +data you again you have to take with a +grain of salt but it's good to you know + + align:start position:0% +grain of salt but it's good to you know + + + align:start position:0% +grain of salt but it's good to you know +if you use that in conjunction with your + + align:start position:0% +if you use that in conjunction with your + + + align:start position:0% +if you use that in conjunction with your +own visual observations and talking to + + align:start position:0% +own visual observations and talking to + + + align:start position:0% +own visual observations and talking to +people it's it's better than nothing. um + + align:start position:0% +people it's it's better than nothing. um + + + align:start position:0% +people it's it's better than nothing. um +which is the alternative or you know a + + align:start position:0% +which is the alternative or you know a + + + align:start position:0% +which is the alternative or you know a +million-dollar 10-year study which um + + align:start position:0% +million-dollar 10-year study which um + + + align:start position:0% +million-dollar 10-year study which um +isn't viable either. So we're gonna just + + align:start position:0% +isn't viable either. So we're gonna just + + + align:start position:0% +isn't viable either. So we're gonna just +look at wind speed at 50 uh meters + + align:start position:0% + + + + align:start position:0% + +for that area of Nicaragua I just + + align:start position:0% +for that area of Nicaragua I just + + + align:start position:0% +for that area of Nicaragua I just +selected. + + align:start position:0% + + + + align:start position:0% + +And you can see the like a 10-year + + align:start position:0% +And you can see the like a 10-year + + + align:start position:0% +And you can see the like a 10-year +average and a minimum and maximum + + align:start position:0% +average and a minimum and maximum + + + align:start position:0% +average and a minimum and maximum +variation. So, it's pretty helpful just + + align:start position:0% +variation. So, it's pretty helpful just + + + align:start position:0% +variation. So, it's pretty helpful just +to get get you into the ballpark of do I + + align:start position:0% +to get get you into the ballpark of do I + + + align:start position:0% +to get get you into the ballpark of do I +have a shot of thinking this might work? + + align:start position:0% +have a shot of thinking this might work? + + + align:start position:0% +have a shot of thinking this might work? +And then some of the other things uh + + align:start position:0% +And then some of the other things uh + + + align:start position:0% +And then some of the other things uh +that you can select for are like, you + + align:start position:0% +that you can select for are like, you + + + align:start position:0% +that you can select for are like, you +know, what how high you are. Um, so + + align:start position:0% +know, what how high you are. Um, so + + + align:start position:0% +know, what how high you are. Um, so +Jessica, this is getting to what you + + align:start position:0% +Jessica, this is getting to what you + + + align:start position:0% +Jessica, this is getting to what you +were interested in. Um, like an an + + align:start position:0% +were interested in. Um, like an an + + + align:start position:0% +were interested in. Um, like an an +estimate of where you are and what your + + align:start position:0% +estimate of where you are and what your + + + align:start position:0% +estimate of where you are and what your +ground cover is and then it sort of + + align:start position:0% +ground cover is and then it sort of + + + align:start position:0% +ground cover is and then it sort of +extrapolates what the what the wind will + + align:start position:0% +extrapolates what the what the wind will + + + align:start position:0% +extrapolates what the what the wind will +be. So, it's pretty useful um and + + align:start position:0% +be. So, it's pretty useful um and + + + align:start position:0% +be. So, it's pretty useful um and +powerful. Is it 100% accurate given that + + align:start position:0% +powerful. Is it 100% accurate given that + + + align:start position:0% +powerful. Is it 100% accurate given that +it's doing really broadbased readings? + + align:start position:0% +it's doing really broadbased readings? + + + align:start position:0% +it's doing really broadbased readings? +Of course not. But it's a start. Um so + + align:start position:0% +Of course not. But it's a start. Um so + + + align:start position:0% +Of course not. But it's a start. Um so +it's nice it's it's a nice uh resource + + align:start position:0% +it's nice it's it's a nice uh resource + + + align:start position:0% +it's nice it's it's a nice uh resource +to know about. + + align:start position:0% +to know about. + + + align:start position:0% +to know about. +Uh so now I want to spend a little time + + align:start position:0% +Uh so now I want to spend a little time + + + align:start position:0% +Uh so now I want to spend a little time +to talk about examples of wind power in + + align:start position:0% +to talk about examples of wind power in + + + align:start position:0% +to talk about examples of wind power in +developing countries. + + align:start position:0% +developing countries. + + + align:start position:0% +developing countries. +So, one is the humdinger wing belt, + + align:start position:0% +So, one is the humdinger wing belt, + + + align:start position:0% +So, one is the humdinger wing belt, +which is totally different from what + + align:start position:0% +which is totally different from what + + + align:start position:0% +which is totally different from what +you're used to seeing and was developed + + align:start position:0% +you're used to seeing and was developed + + + align:start position:0% +you're used to seeing and was developed +by a student who actually took one of + + align:start position:0% +by a student who actually took one of + + + align:start position:0% +by a student who actually took one of +the first DAB classes um when it was + + align:start position:0% +the first DAB classes um when it was + + + align:start position:0% +the first DAB classes um when it was +back when it was the Haiti class. Um, + + align:start position:0% +back when it was the Haiti class. Um, + + + align:start position:0% +back when it was the Haiti class. Um, +and we have a wind belt here, but I + + align:start position:0% +and we have a wind belt here, but I + + + align:start position:0% +and we have a wind belt here, but I +couldn't find it. So, maybe during break + + align:start position:0% +couldn't find it. So, maybe during break + + + align:start position:0% +couldn't find it. So, maybe during break +I'll be able to dig it up or if not, + + align:start position:0% +I'll be able to dig it up or if not, + + + align:start position:0% +I'll be able to dig it up or if not, +maybe we can bring it up by Friday and + + align:start position:0% +maybe we can bring it up by Friday and + + + align:start position:0% +maybe we can bring it up by Friday and +show it in lab on Friday. Um, so the way + + align:start position:0% +show it in lab on Friday. Um, so the way + + + align:start position:0% +show it in lab on Friday. Um, so the way +the wind belt works is that instead of a + + align:start position:0% +the wind belt works is that instead of a + + + align:start position:0% +the wind belt works is that instead of a +rotation, it just uses um the vibration + + align:start position:0% +rotation, it just uses um the vibration + + + align:start position:0% +rotation, it just uses um the vibration +of the belt very similar to I don't know + + align:start position:0% +of the belt very similar to I don't know + + + align:start position:0% +of the belt very similar to I don't know +if you if you guys can remember the um + + align:start position:0% +if you if you guys can remember the um + + + align:start position:0% +if you if you guys can remember the um +the name of the the bridge that um + + align:start position:0% +the name of the the bridge that um + + + align:start position:0% +the name of the the bridge that um +collapsed. + + align:start position:0% +collapsed. + + + align:start position:0% +collapsed. +Yeah. Does everyone know the Tacoma + + align:start position:0% +Yeah. Does everyone know the Tacoma + + + align:start position:0% +Yeah. Does everyone know the Tacoma +Bridge? Yeah. So uh well Google it + + align:start position:0% +Bridge? Yeah. So uh well Google it + + + align:start position:0% +Bridge? Yeah. So uh well Google it +because you can see videos and it's + + align:start position:0% +because you can see videos and it's + + + align:start position:0% +because you can see videos and it's +awesome if you haven't. So, + + align:start position:0% +awesome if you haven't. So, + + + align:start position:0% +awesome if you haven't. So, +um yeah, it is totally scary, especially + + align:start position:0% +um yeah, it is totally scary, especially + + + align:start position:0% +um yeah, it is totally scary, especially +because um + + align:start position:0% +because um + + + align:start position:0% +because um +I have a friend who did some research + + align:start position:0% +I have a friend who did some research + + + align:start position:0% +I have a friend who did some research +into it and so this bridge um was a + + align:start position:0% +into it and so this bridge um was a + + + align:start position:0% +into it and so this bridge um was a +super long bridge and uh it just had + + align:start position:0% +super long bridge and uh it just had + + + align:start position:0% +super long bridge and uh it just had +natural frequencies at the same uh rate + + align:start position:0% +natural frequencies at the same uh rate + + + align:start position:0% +natural frequencies at the same uh rate +as the wind was off and blowing. And so + + align:start position:0% +as the wind was off and blowing. And so + + + align:start position:0% +as the wind was off and blowing. And so +the bridge would just go up and down and + + align:start position:0% +the bridge would just go up and down and + + + align:start position:0% +the bridge would just go up and down and +up and down crazily. And eventually one + + align:start position:0% +up and down crazily. And eventually one + + + align:start position:0% +up and down crazily. And eventually one +day it got so bad that it completely + + align:start position:0% +day it got so bad that it completely + + + align:start position:0% +day it got so bad that it completely +broke apart. And the crazy thing is that + + align:start position:0% +broke apart. And the crazy thing is that + + + align:start position:0% +broke apart. And the crazy thing is that +people used to hang out on the bridge on + + align:start position:0% +people used to hang out on the bridge on + + + align:start position:0% +people used to hang out on the bridge on +the really windy days because it was so + + align:start position:0% +the really windy days because it was so + + + align:start position:0% +the really windy days because it was so +fun like you know it's like a roller + + align:start position:0% +fun like you know it's like a roller + + + align:start position:0% +fun like you know it's like a roller +coaster. So it's extra scary thinking + + align:start position:0% +coaster. So it's extra scary thinking + + + align:start position:0% +coaster. So it's extra scary thinking +about that. So anyway, but this this was + + align:start position:0% +about that. So anyway, but this this was + + + align:start position:0% +about that. So anyway, but this this was +the sort of the inspiration um for the + + align:start position:0% +the sort of the inspiration um for the + + + align:start position:0% +the sort of the inspiration um for the +humdinger which just has a really + + align:start position:0% +humdinger which just has a really + + + align:start position:0% +humdinger which just has a really +tightly pulled belt in the middle um of + + align:start position:0% +tightly pulled belt in the middle um of + + + align:start position:0% +tightly pulled belt in the middle um of +a support structure so that the and you + + align:start position:0% +a support structure so that the and you + + + align:start position:0% +a support structure so that the and you +put this wind so the wind is going + + align:start position:0% +put this wind so the wind is going + + + align:start position:0% +put this wind so the wind is going +perpendicular to the board. And so that + + align:start position:0% +perpendicular to the board. And so that + + + align:start position:0% +perpendicular to the board. And so that +hits the natural frequencies of the belt + + align:start position:0% +hits the natural frequencies of the belt + + + align:start position:0% +hits the natural frequencies of the belt +and causes it to vibrate. And then you + + align:start position:0% +and causes it to vibrate. And then you + + + align:start position:0% +and causes it to vibrate. And then you +just have some magnets next to a coil on + + align:start position:0% +just have some magnets next to a coil on + + + align:start position:0% +just have some magnets next to a coil on +the corner that allow you to generate + + align:start position:0% +the corner that allow you to generate + + + align:start position:0% +the corner that allow you to generate +electricity. So for um certain + + align:start position:0% +electricity. So for um certain + + + align:start position:0% +electricity. So for um certain +applications, this can be a really + + align:start position:0% +applications, this can be a really + + + align:start position:0% +applications, this can be a really +lowcost way to provide electricity and + + align:start position:0% +lowcost way to provide electricity and + + + align:start position:0% +lowcost way to provide electricity and +you can you this is a pretty relatively + + align:start position:0% +you can you this is a pretty relatively + + + align:start position:0% +you can you this is a pretty relatively +fancy way of building it. But you can + + align:start position:0% +fancy way of building it. But you can + + + align:start position:0% +fancy way of building it. But you can +imagine and they have building it out of + + align:start position:0% +imagine and they have building it out of + + + align:start position:0% +imagine and they have building it out of +like a PVC pipe um which you can get + + align:start position:0% +like a PVC pipe um which you can get + + + align:start position:0% +like a PVC pipe um which you can get +anywhere um and build building it really + + align:start position:0% +anywhere um and build building it really + + + align:start position:0% +anywhere um and build building it really +simply and because there's no very few + + align:start position:0% +simply and because there's no very few + + + align:start position:0% +simply and because there's no very few +moving parts and nothing rotating it's + + align:start position:0% +moving parts and nothing rotating it's + + + align:start position:0% +moving parts and nothing rotating it's +much easier to build than even a + + align:start position:0% +much easier to build than even a + + + align:start position:0% +much easier to build than even a +vertical axis wind turbine. Um and so + + align:start position:0% +vertical axis wind turbine. Um and so + + + align:start position:0% +vertical axis wind turbine. Um and so +it's a really neat application and you + + align:start position:0% +it's a really neat application and you + + + align:start position:0% +it's a really neat application and you +know hypothetically you could imagine + + align:start position:0% +know hypothetically you could imagine + + + align:start position:0% +know hypothetically you could imagine +building it into structures like um + + align:start position:0% +building it into structures like um + + + align:start position:0% +building it into structures like um +railings on buildings and stuff um in + + align:start position:0% +railings on buildings and stuff um in + + + align:start position:0% +railings on buildings and stuff um in +order to uh power different things. So + + align:start position:0% +order to uh power different things. So + + + align:start position:0% +order to uh power different things. So +this is one example and we do have at + + align:start position:0% +this is one example and we do have at + + + align:start position:0% +this is one example and we do have at +least a couple at DAB so we'll make sure + + align:start position:0% +least a couple at DAB so we'll make sure + + + align:start position:0% +least a couple at DAB so we'll make sure +to show you them later today or + + align:start position:0% +to show you them later today or + + + align:start position:0% +to show you them later today or +tomorrow. + + align:start position:0% +tomorrow. + + + align:start position:0% +tomorrow. +Um another example is there sort of the + + align:start position:0% +Um another example is there sort of the + + + align:start position:0% +Um another example is there sort of the +classic um wind turbine in developing + + align:start position:0% +classic um wind turbine in developing + + + align:start position:0% +classic um wind turbine in developing +countries was designed by Hugh Pigot. Um + + align:start position:0% +countries was designed by Hugh Pigot. Um + + + align:start position:0% +countries was designed by Hugh Pigot. Um +and + + align:start position:0% +and + + + align:start position:0% +and +these are pictures of work being done at + + align:start position:0% +these are pictures of work being done at + + + align:start position:0% +these are pictures of work being done at +Blue Energy on which is in Blue Fields + + align:start position:0% +Blue Energy on which is in Blue Fields + + + align:start position:0% +Blue Energy on which is in Blue Fields +in Nicaragua and we worked with them + + align:start position:0% +in Nicaragua and we worked with them + + + align:start position:0% +in Nicaragua and we worked with them +last year. Um and they build all these + + align:start position:0% +last year. Um and they build all these + + + align:start position:0% +last year. Um and they build all these +turbines. So you can see there's the the + + align:start position:0% +turbines. So you can see there's the the + + + align:start position:0% +turbines. So you can see there's the the +support wires and that you can rotate + + align:start position:0% +support wires and that you can rotate + + + align:start position:0% +support wires and that you can rotate +the uh the turbine down so that you can + + align:start position:0% +the uh the turbine down so that you can + + + align:start position:0% +the uh the turbine down so that you can +um do maintenance on it. Um which is a + + align:start position:0% +um do maintenance on it. Um which is a + + + align:start position:0% +um do maintenance on it. Um which is a +really nice feature. So that's one sort + + align:start position:0% +really nice feature. So that's one sort + + + align:start position:0% +really nice feature. So that's one sort +of classic design that's pretty common + + align:start position:0% +of classic design that's pretty common + + + align:start position:0% +of classic design that's pretty common +in developing countries. Um and then a + + align:start position:0% +in developing countries. Um and then a + + + align:start position:0% +in developing countries. Um and then a +lot of people have heard of William + + align:start position:0% +lot of people have heard of William + + + align:start position:0% +lot of people have heard of William +Kamwamba. Oh, there's the wind belt. So + + align:start position:0% +Kamwamba. Oh, there's the wind belt. So + + + align:start position:0% +Kamwamba. Oh, there's the wind belt. So +let me go back to that. So I'll pass + + align:start position:0% +let me go back to that. So I'll pass + + + align:start position:0% +let me go back to that. So I'll pass +this around but you and the belt is not + + align:start position:0% +this around but you and the belt is not + + + align:start position:0% +this around but you and the belt is not +exactly taught at the moment. Um, but + + align:start position:0% +exactly taught at the moment. Um, but + + + align:start position:0% +exactly taught at the moment. Um, but +you can see just the belt, + + align:start position:0% +you can see just the belt, + + + align:start position:0% +you can see just the belt, +the magnet on the belt that goes against + + align:start position:0% +the magnet on the belt that goes against + + + align:start position:0% +the magnet on the belt that goes against +the coil, and that's really all there is + + align:start position:0% +the coil, and that's really all there is + + + align:start position:0% +the coil, and that's really all there is +to it. And then a little bit of + + align:start position:0% +to it. And then a little bit of + + + align:start position:0% +to it. And then a little bit of +circuitry in order to generate power, + + align:start position:0% +circuitry in order to generate power, + + + align:start position:0% +circuitry in order to generate power, +which is a really simple way to do + + align:start position:0% +which is a really simple way to do + + + align:start position:0% +which is a really simple way to do +things. + + align:start position:0% +things. + + + align:start position:0% +things. +So, what's the idea? The wind goes + + align:start position:0% +So, what's the idea? The wind goes + + + align:start position:0% +So, what's the idea? The wind goes +through the tape there. + + align:start position:0% +through the tape there. + + + align:start position:0% +through the tape there. +Yeah. + + align:start position:0% +Yeah. + + + align:start position:0% +Yeah. +And the tape vibrates because it hits + + align:start position:0% +And the tape vibrates because it hits + + + align:start position:0% +And the tape vibrates because it hits +natural frequencies and the vibration + + align:start position:0% +natural frequencies and the vibration + + + align:start position:0% +natural frequencies and the vibration +allows you to generate electricity. It's + + align:start position:0% +allows you to generate electricity. It's + + + align:start position:0% +allows you to generate electricity. It's +movement is all you need. + + align:start position:0% + + + + align:start position:0% + +Thanks. + + align:start position:0% +Thanks. + + + align:start position:0% +Thanks. +Um, so William Kamwamba + + align:start position:0% +Um, so William Kamwamba + + + align:start position:0% +Um, so William Kamwamba +um was this guy. + + align:start position:0% +um was this guy. + + + align:start position:0% +um was this guy. +Where did he live? Did I write it down? + + align:start position:0% +Where did he live? Did I write it down? + + + align:start position:0% +Where did he live? Did I write it down? +in Malawi and he just got really + + align:start position:0% +in Malawi and he just got really + + + align:start position:0% +in Malawi and he just got really +interested in how how he could get + + align:start position:0% +interested in how how he could get + + + align:start position:0% +interested in how how he could get +electricity at his house and went to the + + align:start position:0% +electricity at his house and went to the + + + align:start position:0% +electricity at his house and went to the +library and read a bunch of books and + + align:start position:0% +library and read a bunch of books and + + + align:start position:0% +library and read a bunch of books and +got inspired and built his own um wind + + align:start position:0% +got inspired and built his own um wind + + + align:start position:0% +got inspired and built his own um wind +turbine which doesn't look like your + + align:start position:0% +turbine which doesn't look like your + + + align:start position:0% +turbine which doesn't look like your +traditional wind turbine. Um there are a + + align:start position:0% +traditional wind turbine. Um there are a + + + align:start position:0% +traditional wind turbine. Um there are a +few design improvements that could be + + align:start position:0% +few design improvements that could be + + + align:start position:0% +few design improvements that could be +made, especially with better resources. + + align:start position:0% +made, especially with better resources. + + + align:start position:0% +made, especially with better resources. +um but worked well enough for him to + + align:start position:0% +um but worked well enough for him to + + + align:start position:0% +um but worked well enough for him to +power a radio at his house and charge + + align:start position:0% +power a radio at his house and charge + + + align:start position:0% +power a radio at his house and charge +cell phones which got people really + + align:start position:0% +cell phones which got people really + + + align:start position:0% +cell phones which got people really +excited so that then he could they would + + align:start position:0% +excited so that then he could they would + + + align:start position:0% +excited so that then he could they would +start paying him so he could start + + align:start position:0% +start paying him so he could start + + + align:start position:0% +start paying him so he could start +building um more and more um turbines. + + align:start position:0% +building um more and more um turbines. + + + align:start position:0% +building um more and more um turbines. +So it's a really cool + + align:start position:0% +So it's a really cool + + + align:start position:0% +So it's a really cool +story and now he's at Dartmouth um doing + + align:start position:0% +story and now he's at Dartmouth um doing + + + align:start position:0% +story and now he's at Dartmouth um doing +in school which he never could have done + + align:start position:0% +in school which he never could have done + + + align:start position:0% +in school which he never could have done +had he not um built this turbine. So + + align:start position:0% +had he not um built this turbine. So + + + align:start position:0% +had he not um built this turbine. So +he's a cool guy. Um, we may be able to + + align:start position:0% +he's a cool guy. Um, we may be able to + + + align:start position:0% +he's a cool guy. Um, we may be able to +get him to come down to talk to our + + align:start position:0% +get him to come down to talk to our + + + align:start position:0% +get him to come down to talk to our +class this year. We'll see. I'm trying. + + align:start position:0% +class this year. We'll see. I'm trying. + + + align:start position:0% +class this year. We'll see. I'm trying. +Um, but his adviser at Dartmouth is very + + align:start position:0% +Um, but his adviser at Dartmouth is very + + + align:start position:0% +Um, but his adviser at Dartmouth is very +reluctant to let him travel. I'm sorry. + + align:start position:0% +reluctant to let him travel. I'm sorry. + + + align:start position:0% +reluctant to let him travel. I'm sorry. +Yeah. So, but because he didn't grow up + + align:start position:0% +Yeah. So, but because he didn't grow up + + + align:start position:0% +Yeah. So, but because he didn't grow up +here, like he's getting very um parented + + align:start position:0% +here, like he's getting very um parented + + + align:start position:0% +here, like he's getting very um parented +at a different level than um you guys + + align:start position:0% +at a different level than um you guys + + + align:start position:0% +at a different level than um you guys +are. + + align:start position:0% +are. + + + align:start position:0% +are. +So, um by by the professor at Dartmouth. + + align:start position:0% +So, um by by the professor at Dartmouth. + + + align:start position:0% +So, um by by the professor at Dartmouth. +Um so anyway uh so just a cool example + + align:start position:0% +Um so anyway uh so just a cool example + + + align:start position:0% +Um so anyway uh so just a cool example +of something very low tech that worked + + align:start position:0% +of something very low tech that worked + + + align:start position:0% +of something very low tech that worked +really well and u made a remarkable + + align:start position:0% +really well and u made a remarkable + + + align:start position:0% +really well and u made a remarkable +change for this guy and also um his + + align:start position:0% +change for this guy and also um his + + + align:start position:0% +change for this guy and also um his +village. Um and then working all the way + + align:start position:0% +village. Um and then working all the way + + + align:start position:0% +village. Um and then working all the way +down to the really simplest wind + + align:start position:0% +down to the really simplest wind + + + align:start position:0% +down to the really simplest wind +turbine. So, this is a I don't know if + + align:start position:0% +turbine. So, this is a I don't know if + + + align:start position:0% +turbine. So, this is a I don't know if +you say it as Panem or Panamone, but one + + align:start position:0% +you say it as Panem or Panamone, but one + + + align:start position:0% +you say it as Panem or Panamone, but one +of those um wind turbine, which is + + align:start position:0% +of those um wind turbine, which is + + + align:start position:0% +of those um wind turbine, which is +incredibly old technology that was this + + align:start position:0% +incredibly old technology that was this + + + align:start position:0% +incredibly old technology that was this +is the like 10,000 BC technology that + + align:start position:0% +is the like 10,000 BC technology that + + + align:start position:0% +is the like 10,000 BC technology that +we're talking about. And it's just sails + + align:start position:0% +we're talking about. And it's just sails + + + align:start position:0% +we're talking about. And it's just sails +um that rotate. The sails actually each + + align:start position:0% +um that rotate. The sails actually each + + + align:start position:0% +um that rotate. The sails actually each +one rotates 180 degrees. So, they're + + align:start position:0% +one rotates 180 degrees. So, they're + + + align:start position:0% +one rotates 180 degrees. So, they're +always moving in the wind. Um and this + + align:start position:0% +always moving in the wind. Um and this + + + align:start position:0% +always moving in the wind. Um and this +is this is not a turbine. This is a a + + align:start position:0% +is this is not a turbine. This is a a + + + align:start position:0% +is this is not a turbine. This is a a +mill. So, the act of it spinning pulls + + align:start position:0% +mill. So, the act of it spinning pulls + + + align:start position:0% +mill. So, the act of it spinning pulls +this rope pump. Maybe if I turn off the + + align:start position:0% +this rope pump. Maybe if I turn off the + + + align:start position:0% +this rope pump. Maybe if I turn off the +light so it'll be easier to see. + + align:start position:0% + + + + align:start position:0% + +So, there's a rope pump here. And the + + align:start position:0% +So, there's a rope pump here. And the + + + align:start position:0% +So, there's a rope pump here. And the +way a rope pump works is incredibly + + align:start position:0% +way a rope pump works is incredibly + + + align:start position:0% +way a rope pump works is incredibly +simple. So, you just have a rope inside + + align:start position:0% +simple. So, you just have a rope inside + + + align:start position:0% +simple. So, you just have a rope inside +a tube + + align:start position:0% + + + + align:start position:0% + +um that goes down into the water um + + align:start position:0% +um that goes down into the water um + + + align:start position:0% +um that goes down into the water um +table so that you're you're filling um + + align:start position:0% +table so that you're you're filling um + + + align:start position:0% +table so that you're you're filling um +you're getting water um + + align:start position:0% +you're getting water um + + + align:start position:0% +you're getting water um +through holes in the in the tube. And + + align:start position:0% +through holes in the in the tube. And + + + align:start position:0% +through holes in the in the tube. And +then you either have knots in the rope + + align:start position:0% +then you either have knots in the rope + + + align:start position:0% +then you either have knots in the rope +or if you can find them, rubber washers + + align:start position:0% +or if you can find them, rubber washers + + + align:start position:0% +or if you can find them, rubber washers +like every foot along the tube. And this + + align:start position:0% +like every foot along the tube. And this + + + align:start position:0% +like every foot along the tube. And this +is obviously not to scale in any way. + + align:start position:0% +is obviously not to scale in any way. + + + align:start position:0% +is obviously not to scale in any way. +Um, and so the water gets trapped + + align:start position:0% +Um, and so the water gets trapped + + + align:start position:0% +Um, and so the water gets trapped +between the washers and you pull up the + + align:start position:0% +between the washers and you pull up the + + + align:start position:0% +between the washers and you pull up the +water that way. And so this is really + + align:start position:0% +water that way. And so this is really + + + align:start position:0% +water that way. And so this is really +simple. Again, we're talking about + + align:start position:0% +simple. Again, we're talking about + + + align:start position:0% +simple. Again, we're talking about +ridiculously low efficiencies, but if + + align:start position:0% +ridiculously low efficiencies, but if + + + align:start position:0% +ridiculously low efficiencies, but if +you need to irrigate, this is a way to + + align:start position:0% +you need to irrigate, this is a way to + + + align:start position:0% +you need to irrigate, this is a way to +do it that just uses the wind. Um, it + + align:start position:0% +do it that just uses the wind. Um, it + + + align:start position:0% +do it that just uses the wind. Um, it +works really well. So, and this was + + align:start position:0% +works really well. So, and this was + + + align:start position:0% +works really well. So, and this was +built for $40. So which is ridiculously + + align:start position:0% +built for $40. So which is ridiculously + + + align:start position:0% +built for $40. So which is ridiculously +inexpensive compared to even like a Hugh + + align:start position:0% +inexpensive compared to even like a Hugh + + + align:start position:0% +inexpensive compared to even like a Hugh +Pigot wind turbine which is you know in + + align:start position:0% +Pigot wind turbine which is you know in + + + align:start position:0% +Pigot wind turbine which is you know in +the thousands of dollars. So there are + + align:start position:0% +the thousands of dollars. So there are + + + align:start position:0% +the thousands of dollars. So there are +opportunities for a whole range of + + align:start position:0% +opportunities for a whole range of + + + align:start position:0% +opportunities for a whole range of +possibilities. And then yeah there's + + align:start position:0% +possibilities. And then yeah there's + + + align:start position:0% +possibilities. And then yeah there's +just so many different types out there. + + align:start position:0% +just so many different types out there. + + + align:start position:0% +just so many different types out there. +So if you look into it wind is one of + + align:start position:0% +So if you look into it wind is one of + + + align:start position:0% +So if you look into it wind is one of +the areas where people get really + + align:start position:0% +the areas where people get really + + + align:start position:0% +the areas where people get really +excited and like to build their own + + align:start position:0% +excited and like to build their own + + + align:start position:0% +excited and like to build their own +stuff. And so you can see a huge v + + align:start position:0% +stuff. And so you can see a huge v + + + align:start position:0% +stuff. And so you can see a huge v +variety of designs in the world. + + align:start position:0% +variety of designs in the world. + + + align:start position:0% +variety of designs in the world. +So that's wind in a very fast nutshell. + + align:start position:0% +So that's wind in a very fast nutshell. + + + align:start position:0% +So that's wind in a very fast nutshell. +Are there any questions about that? + + align:start position:0% + + + + align:start position:0% + +Okay, so uh next is micro hydro. Um and + + align:start position:0% +Okay, so uh next is micro hydro. Um and + + + align:start position:0% +Okay, so uh next is micro hydro. Um and +microhydro is kind of funny because it's + + align:start position:0% +microhydro is kind of funny because it's + + + align:start position:0% +microhydro is kind of funny because it's +harder to find really good examples of + + align:start position:0% +harder to find really good examples of + + + align:start position:0% +harder to find really good examples of +installations in the developing world + + align:start position:0% +installations in the developing world + + + align:start position:0% +installations in the developing world +because they tend to be just built but + + align:start position:0% +because they tend to be just built but + + + align:start position:0% +because they tend to be just built but +not well documented is what I'm finding. + + align:start position:0% +not well documented is what I'm finding. + + + align:start position:0% +not well documented is what I'm finding. +So, um, so I'm going to talk more about + + align:start position:0% +So, um, so I'm going to talk more about + + + align:start position:0% +So, um, so I'm going to talk more about +how you would, + + align:start position:0% +how you would, + + + align:start position:0% +how you would, +uh, determine if a microhydro + + align:start position:0% +uh, determine if a microhydro + + + align:start position:0% +uh, determine if a microhydro +installation would be appropriate, and I + + align:start position:0% +installation would be appropriate, and I + + + align:start position:0% +installation would be appropriate, and I +don't have as many good examples of + + align:start position:0% +don't have as many good examples of + + + align:start position:0% +don't have as many good examples of +installations that are successful, but + + align:start position:0% +installations that are successful, but + + + align:start position:0% +installations that are successful, but +um, they're certainly out there. Uh, so + + align:start position:0% +um, they're certainly out there. Uh, so + + + align:start position:0% +um, they're certainly out there. Uh, so +hydro power is just using the + + align:start position:0% +hydro power is just using the + + + align:start position:0% +hydro power is just using the +gravitational flow of water to generate + + align:start position:0% +gravitational flow of water to generate + + + align:start position:0% +gravitational flow of water to generate +power. Um, considering both the the two + + align:start position:0% +power. Um, considering both the the two + + + align:start position:0% +power. Um, considering both the the two +terms I'm going to use are head and flow + + align:start position:0% +terms I'm going to use are head and flow + + + align:start position:0% +terms I'm going to use are head and flow +rate. So head is the distance that the + + align:start position:0% +rate. So head is the distance that the + + + align:start position:0% +rate. So head is the distance that the +water falls and flow rate is how quickly + + align:start position:0% +water falls and flow rate is how quickly + + + align:start position:0% +water falls and flow rate is how quickly +the water is moving. Um and so hydro + + align:start position:0% +the water is moving. Um and so hydro + + + align:start position:0% +the water is moving. Um and so hydro +power can be at you know two megawws and + + align:start position:0% +power can be at you know two megawws and + + + align:start position:0% +power can be at you know two megawws and +much beyond and can be a sizable um is a + + align:start position:0% +much beyond and can be a sizable um is a + + + align:start position:0% +much beyond and can be a sizable um is a +sizable impact on our nation's + + align:start position:0% +sizable impact on our nation's + + + align:start position:0% +sizable impact on our nation's +electricity supply for example all the + + align:start position:0% +electricity supply for example all the + + + align:start position:0% +electricity supply for example all the +way down to a 200 watt um turbine or + + align:start position:0% +way down to a 200 watt um turbine or + + + align:start position:0% +way down to a 200 watt um turbine or +smaller. Um so I'm saying micro hydro + + align:start position:0% +smaller. Um so I'm saying micro hydro + + + align:start position:0% +smaller. Um so I'm saying micro hydro +for this lecture. probably some of the + + align:start position:0% +for this lecture. probably some of the + + + align:start position:0% +for this lecture. probably some of the +stuff I'm talking about is actually pico + + align:start position:0% +stuff I'm talking about is actually pico + + + align:start position:0% +stuff I'm talking about is actually pico +or mini um ranging um it's and everyone + + align:start position:0% +or mini um ranging um it's and everyone + + + align:start position:0% +or mini um ranging um it's and everyone +defines these differently. So if you + + align:start position:0% +defines these differently. So if you + + + align:start position:0% +defines these differently. So if you +look up what pico hydro is you'll see 10 + + align:start position:0% +look up what pico hydro is you'll see 10 + + + align:start position:0% +look up what pico hydro is you'll see 10 +different definitions. So it's not + + align:start position:0% +different definitions. So it's not + + + align:start position:0% +different definitions. So it's not +critical that you're getting exactly and + + align:start position:0% +critical that you're getting exactly and + + + align:start position:0% +critical that you're getting exactly and +you can even see I + + align:start position:0% +you can even see I + + + align:start position:0% +you can even see I +there's there's uh between pico and + + align:start position:0% +there's there's uh between pico and + + + align:start position:0% +there's there's uh between pico and +micro there's something right. + + align:start position:0% +micro there's something right. + + + align:start position:0% +micro there's something right. +So according to this definition um + + align:start position:0% + + + + align:start position:0% + +yeah so and this is with water power + + align:start position:0% +yeah so and this is with water power + + + align:start position:0% +yeah so and this is with water power +it's the same um as wind in terms of + + align:start position:0% +it's the same um as wind in terms of + + + align:start position:0% +it's the same um as wind in terms of +there's mills and there's turbines so + + align:start position:0% +there's mills and there's turbines so + + + align:start position:0% +there's mills and there's turbines so +you can think of the the o old grist + + align:start position:0% +you can think of the the o old grist + + + align:start position:0% +you can think of the the o old grist +mills and other things that you can see + + align:start position:0% +mills and other things that you can see + + + align:start position:0% +mills and other things that you can see +in parts of New England still um + + align:start position:0% +in parts of New England still um + + + align:start position:0% +in parts of New England still um +they're again they're low velocity high + + align:start position:0% +they're again they're low velocity high + + + align:start position:0% +they're again they're low velocity high +torque delivering mechanical power + + align:start position:0% +torque delivering mechanical power + + + align:start position:0% +torque delivering mechanical power +directly + + align:start position:0% +directly + + + align:start position:0% +directly +um + + align:start position:0% +um + + + align:start position:0% +um +as opposed to a turbine which is higher + + align:start position:0% +as opposed to a turbine which is higher + + + align:start position:0% +as opposed to a turbine which is higher +much higher velocity much lower torque + + align:start position:0% +much higher velocity much lower torque + + + align:start position:0% +much higher velocity much lower torque +to allow you to generate electricity. So + + align:start position:0% +to allow you to generate electricity. So + + + align:start position:0% +to allow you to generate electricity. So +those are the two extremes. Um yeah + + align:start position:0% + + + + align:start position:0% + +in terms of micro or hydro power there's + + align:start position:0% +in terms of micro or hydro power there's + + + align:start position:0% +in terms of micro or hydro power there's +two methods. So, one is called run of + + align:start position:0% +two methods. So, one is called run of + + + align:start position:0% +two methods. So, one is called run of +the river, and that means that you're + + align:start position:0% +the river, and that means that you're + + + align:start position:0% +the river, and that means that you're +just taking a chunk of the river um and + + align:start position:0% +just taking a chunk of the river um and + + + align:start position:0% +just taking a chunk of the river um and +siphoning it siphoning it off into a + + align:start position:0% +siphoning it siphoning it off into a + + + align:start position:0% +siphoning it siphoning it off into a +tube that goes directly into your + + align:start position:0% +tube that goes directly into your + + + align:start position:0% +tube that goes directly into your +turbine. Um the as and the other option + + align:start position:0% +turbine. Um the as and the other option + + + align:start position:0% +turbine. Um the as and the other option +is a dam. So, the benefits of this are + + align:start position:0% +is a dam. So, the benefits of this are + + + align:start position:0% +is a dam. So, the benefits of this are +that it's relatively simple. You can + + align:start position:0% +that it's relatively simple. You can + + + align:start position:0% +that it's relatively simple. You can +build it locally um compared to a dam is + + align:start position:0% +build it locally um compared to a dam is + + + align:start position:0% +build it locally um compared to a dam is +much harder harder to build generally. + + align:start position:0% +much harder harder to build generally. + + + align:start position:0% +much harder harder to build generally. +Um it's comparatively lower much lower + + align:start position:0% +Um it's comparatively lower much lower + + + align:start position:0% +Um it's comparatively lower much lower +environmental impact than a dam. um + + align:start position:0% +environmental impact than a dam. um + + + align:start position:0% +environmental impact than a dam. um +they're relatively affordable. Um but + + align:start position:0% +they're relatively affordable. Um but + + + align:start position:0% +they're relatively affordable. Um but +when you have a drought, you don't have + + align:start position:0% +when you have a drought, you don't have + + + align:start position:0% +when you have a drought, you don't have +any storage like you have with a dam. So + + align:start position:0% +any storage like you have with a dam. So + + + align:start position:0% +any storage like you have with a dam. So +that's the drawback. Uh + + align:start position:0% +that's the drawback. Uh + + + align:start position:0% +that's the drawback. Uh +and the dam is, you know, the reverse + + align:start position:0% +and the dam is, you know, the reverse + + + align:start position:0% +and the dam is, you know, the reverse +that you can accumulate your rainfall, + + align:start position:0% +that you can accumulate your rainfall, + + + align:start position:0% +that you can accumulate your rainfall, +which is great, but it's relatively + + align:start position:0% +which is great, but it's relatively + + + align:start position:0% +which is great, but it's relatively +expensive and there's a greater + + align:start position:0% +expensive and there's a greater + + + align:start position:0% +expensive and there's a greater +environmental impact on the negative. Um + + align:start position:0% +environmental impact on the negative. Um + + + align:start position:0% +environmental impact on the negative. Um +because damning up water affects the + + align:start position:0% +because damning up water affects the + + + align:start position:0% +because damning up water affects the +local environment from the fish to just + + align:start position:0% +local environment from the fish to just + + + align:start position:0% +local environment from the fish to just +what the fields look like etc etc. Um + + align:start position:0% +what the fields look like etc etc. Um + + + align:start position:0% +what the fields look like etc etc. Um +I'm sure you've heard of dams in China + + align:start position:0% +I'm sure you've heard of dams in China + + + align:start position:0% +I'm sure you've heard of dams in China +or similar that um you know have + + align:start position:0% +or similar that um you know have + + + align:start position:0% +or similar that um you know have +destroyed entire like many entire + + align:start position:0% +destroyed entire like many entire + + + align:start position:0% +destroyed entire like many entire +communities um for building dams on a + + align:start position:0% +communities um for building dams on a + + + align:start position:0% +communities um for building dams on a +very very large scale. Um and then + + align:start position:0% + + + + align:start position:0% + +yeah and there's more maintenance + + align:start position:0% +yeah and there's more maintenance + + + align:start position:0% +yeah and there's more maintenance +associated with the dam too in terms of + + align:start position:0% +associated with the dam too in terms of + + + align:start position:0% +associated with the dam too in terms of +silt silt accumulation. It's it's + + align:start position:0% +silt silt accumulation. It's it's + + + align:start position:0% +silt silt accumulation. It's it's +challenging. Um so we're just going to + + align:start position:0% +challenging. Um so we're just going to + + + align:start position:0% +challenging. Um so we're just going to +talk about the run of the river model. + + align:start position:0% +talk about the run of the river model. + + + align:start position:0% +talk about the run of the river model. +So the components that you have is + + align:start position:0% +So the components that you have is + + + align:start position:0% +So the components that you have is +something called a wear that diverts a + + align:start position:0% +something called a wear that diverts a + + + align:start position:0% +something called a wear that diverts a +chunk of the water into your tube. Um + + align:start position:0% +chunk of the water into your tube. Um + + + align:start position:0% +chunk of the water into your tube. Um +you generally have a settling basin so + + align:start position:0% +you generally have a settling basin so + + + align:start position:0% +you generally have a settling basin so +that any debris um settles out uh + + align:start position:0% +that any debris um settles out uh + + + align:start position:0% +that any debris um settles out uh +because you don't want it going into + + align:start position:0% +because you don't want it going into + + + align:start position:0% +because you don't want it going into +your turbine because you'll destroy your + + align:start position:0% +your turbine because you'll destroy your + + + align:start position:0% +your turbine because you'll destroy your +turbine. Um a for bay which is a small + + align:start position:0% +turbine. Um a for bay which is a small + + + align:start position:0% +turbine. Um a for bay which is a small +holding tank so you're getting reserve + + align:start position:0% +holding tank so you're getting reserve + + + align:start position:0% +holding tank so you're getting reserve +capacity that way but that's talking + + align:start position:0% +capacity that way but that's talking + + + align:start position:0% +capacity that way but that's talking +about like variation on the order of + + align:start position:0% +about like variation on the order of + + + align:start position:0% +about like variation on the order of +seconds or minutes not days or months. + + align:start position:0% +seconds or minutes not days or months. + + + align:start position:0% +seconds or minutes not days or months. +uh pentock, which is a closed pipe + + align:start position:0% +uh pentock, which is a closed pipe + + + align:start position:0% +uh pentock, which is a closed pipe +flowing downhill um that feeds directly + + align:start position:0% +flowing downhill um that feeds directly + + + align:start position:0% +flowing downhill um that feeds directly +into your turbine um that then generates + + align:start position:0% +into your turbine um that then generates + + + align:start position:0% +into your turbine um that then generates +your electricity and then the water is + + align:start position:0% +your electricity and then the water is + + + align:start position:0% +your electricity and then the water is +returned back to the river. There's a + + align:start position:0% +returned back to the river. There's a + + + align:start position:0% +returned back to the river. There's a +lot of different turbine types. Um so + + align:start position:0% +lot of different turbine types. Um so + + + align:start position:0% +lot of different turbine types. Um so +the one of the most efficient, if not + + align:start position:0% +the one of the most efficient, if not + + + align:start position:0% +the one of the most efficient, if not +the most efficient, is called a Pelton + + align:start position:0% +the most efficient, is called a Pelton + + + align:start position:0% +the most efficient, is called a Pelton +wheel. And you can see it's it's got a + + align:start position:0% +wheel. And you can see it's it's got a + + + align:start position:0% +wheel. And you can see it's it's got a +relatively complex geometry. Um and so + + align:start position:0% +relatively complex geometry. Um and so + + + align:start position:0% +relatively complex geometry. Um and so +relatively expensive and challenging to + + align:start position:0% +relatively expensive and challenging to + + + align:start position:0% +relatively expensive and challenging to +build. Um but if you do um it's it's + + align:start position:0% +build. Um but if you do um it's it's + + + align:start position:0% +build. Um but if you do um it's it's +very efficient. Um it works well for a + + align:start position:0% +very efficient. Um it works well for a + + + align:start position:0% +very efficient. Um it works well for a +high head low flow situation. So again + + align:start position:0% +high head low flow situation. So again + + + align:start position:0% +high head low flow situation. So again +head is how far the water is dropping. + + align:start position:0% +head is how far the water is dropping. + + + align:start position:0% +head is how far the water is dropping. +Um Francis wheels which work better for + + align:start position:0% +Um Francis wheels which work better for + + + align:start position:0% +Um Francis wheels which work better for +lower head higher flow. Um which has a + + align:start position:0% +lower head higher flow. Um which has a + + + align:start position:0% +lower head higher flow. Um which has a +high a spiral casing where the water + + align:start position:0% +high a spiral casing where the water + + + align:start position:0% +high a spiral casing where the water +comes in and spins this turbine and then + + align:start position:0% +comes in and spins this turbine and then + + + align:start position:0% +comes in and spins this turbine and then +comes out. uh + + align:start position:0% +comes out. uh + + + align:start position:0% +comes out. uh +cross flow where the water flows over + + align:start position:0% +cross flow where the water flows over + + + align:start position:0% +cross flow where the water flows over +this um cylinder which has a bunch of + + align:start position:0% +this um cylinder which has a bunch of + + + align:start position:0% +this um cylinder which has a bunch of +blades on it and that's what spins the + + align:start position:0% +blades on it and that's what spins the + + + align:start position:0% +blades on it and that's what spins the +spins the ro the shaft to generate + + align:start position:0% +spins the ro the shaft to generate + + + align:start position:0% +spins the ro the shaft to generate +electricity. A propeller which literally + + align:start position:0% +electricity. A propeller which literally + + + align:start position:0% +electricity. A propeller which literally +uses a ship's propeller um and instead + + align:start position:0% +uses a ship's propeller um and instead + + + align:start position:0% +uses a ship's propeller um and instead +of the ship's propeller being powered in + + align:start position:0% +of the ship's propeller being powered in + + + align:start position:0% +of the ship's propeller being powered in +order to move the boat it's it's using + + align:start position:0% +order to move the boat it's it's using + + + align:start position:0% +order to move the boat it's it's using +it in the exact opposite way. Um and you + + align:start position:0% +it in the exact opposite way. Um and you + + + align:start position:0% +it in the exact opposite way. Um and you +can see that these, you know, you need + + align:start position:0% +can see that these, you know, you need + + + align:start position:0% +can see that these, you know, you need +different um types of turbines for + + align:start position:0% +different um types of turbines for + + + align:start position:0% +different um types of turbines for +different flow and head situations. Um + + align:start position:0% +different flow and head situations. Um + + + align:start position:0% +different flow and head situations. Um +and then + + align:start position:0% +and then + + + align:start position:0% +and then +one example is just literally putting + + align:start position:0% +one example is just literally putting + + + align:start position:0% +one example is just literally putting +something in the river, skipping that + + align:start position:0% +something in the river, skipping that + + + align:start position:0% +something in the river, skipping that +all that extra stuff of filtering um of + + align:start position:0% +all that extra stuff of filtering um of + + + align:start position:0% +all that extra stuff of filtering um of +of siphoning off the water and just + + align:start position:0% +of siphoning off the water and just + + + align:start position:0% +of siphoning off the water and just +putting something on top of the water. + + align:start position:0% +putting something on top of the water. + + + align:start position:0% +putting something on top of the water. +Um which seems really simple and great + + align:start position:0% +Um which seems really simple and great + + + align:start position:0% +Um which seems really simple and great +until you think about like all the + + align:start position:0% +until you think about like all the + + + align:start position:0% +until you think about like all the +challenges in terms of flooding and + + align:start position:0% +challenges in terms of flooding and + + + align:start position:0% +challenges in terms of flooding and +debris in the water and etc., etc. This + + align:start position:0% +debris in the water and etc., etc. This + + + align:start position:0% +debris in the water and etc., etc. This +this is a + + align:start position:0% +this is a + + + align:start position:0% +this is a +a device that is really prone to + + align:start position:0% +a device that is really prone to + + + align:start position:0% +a device that is really prone to +failure. Um + + align:start position:0% +failure. Um + + + align:start position:0% +failure. Um +but it works in areas where that's your + + align:start position:0% +but it works in areas where that's your + + + align:start position:0% +but it works in areas where that's your +only option. Um or it can work. Uh yeah. + + align:start position:0% +only option. Um or it can work. Uh yeah. + + + align:start position:0% +only option. Um or it can work. Uh yeah. +So some of the considerations you need + + align:start position:0% +So some of the considerations you need + + + align:start position:0% +So some of the considerations you need +for microhydro + + align:start position:0% +for microhydro + + + align:start position:0% +for microhydro +one is + + align:start position:0% +one is + + + align:start position:0% +one is +uh that + + align:start position:0% +uh that + + + align:start position:0% +uh that +the minimum um head and flow you need is + + align:start position:0% +the minimum um head and flow you need is + + + align:start position:0% +the minimum um head and flow you need is +3 ft of head and 20 gallons per minute + + align:start position:0% +3 ft of head and 20 gallons per minute + + + align:start position:0% +3 ft of head and 20 gallons per minute +of flow. Um so that would be the minimum + + align:start position:0% +of flow. Um so that would be the minimum + + + align:start position:0% +of flow. Um so that would be the minimum +head you need and + + align:start position:0% +head you need and + + + align:start position:0% +head you need and +um + + align:start position:0% +um + + + align:start position:0% +um +if you have more head either bonus you + + align:start position:0% +if you have more head either bonus you + + + align:start position:0% +if you have more head either bonus you +get more power or you can therefore have + + align:start position:0% +get more power or you can therefore have + + + align:start position:0% +get more power or you can therefore have +reduced flow because the the power + + align:start position:0% +reduced flow because the the power + + + align:start position:0% +reduced flow because the the power +equation here is again a coefficient of + + align:start position:0% +equation here is again a coefficient of + + + align:start position:0% +equation here is again a coefficient of +efficiency uh times the water density + + align:start position:0% +efficiency uh times the water density + + + align:start position:0% +efficiency uh times the water density +and gravity times the height which is + + align:start position:0% +and gravity times the height which is + + + align:start position:0% +and gravity times the height which is +your head and Q which is your flow rate. + + align:start position:0% +your head and Q which is your flow rate. + + + align:start position:0% +your head and Q which is your flow rate. +So you can see that HQ you can keep + + align:start position:0% +So you can see that HQ you can keep + + + align:start position:0% +So you can see that HQ you can keep +constant if you you know if you increase + + align:start position:0% +constant if you you know if you increase + + + align:start position:0% +constant if you you know if you increase +your head you can lower your velocity + + align:start position:0% +your head you can lower your velocity + + + align:start position:0% +your head you can lower your velocity +and keep your power constant. Uh + + align:start position:0% +and keep your power constant. Uh + + + align:start position:0% +and keep your power constant. Uh +one nice just rule of thumb is if you + + align:start position:0% +one nice just rule of thumb is if you + + + align:start position:0% +one nice just rule of thumb is if you +stick with SI units row G is about 10. + + align:start position:0% +stick with SI units row G is about 10. + + + align:start position:0% +stick with SI units row G is about 10. +So you can just plug that in rather than + + align:start position:0% +So you can just plug that in rather than + + + align:start position:0% +So you can just plug that in rather than +having to remember the density of water + + align:start position:0% +having to remember the density of water + + + align:start position:0% +having to remember the density of water +and gravity. Though in SI units that's + + align:start position:0% +and gravity. Though in SI units that's + + + align:start position:0% +and gravity. Though in SI units that's +relatively easy but if um + + align:start position:0% +relatively easy but if um + + + align:start position:0% +relatively easy but if um +10 is a nice way to just remember it. Um + + align:start position:0% +10 is a nice way to just remember it. Um + + + align:start position:0% +10 is a nice way to just remember it. Um +and then efficiency is somewhere be + + align:start position:0% +and then efficiency is somewhere be + + + align:start position:0% +and then efficiency is somewhere be +generally between 40 and 70%. + + align:start position:0% +generally between 40 and 70%. + + + align:start position:0% +generally between 40 and 70%. +Uh one other thing to think about is + + align:start position:0% +Uh one other thing to think about is + + + align:start position:0% +Uh one other thing to think about is +just when you have your uh pentock + + align:start position:0% +just when you have your uh pentock + + + align:start position:0% +just when you have your uh pentock +go so that's the water going through the + + align:start position:0% +go so that's the water going through the + + + align:start position:0% +go so that's the water going through the +pipe to get from the top of the river + + align:start position:0% +pipe to get from the top of the river + + + align:start position:0% +pipe to get from the top of the river +down to your generator. Um if your pipe + + align:start position:0% +down to your generator. Um if your pipe + + + align:start position:0% +down to your generator. Um if your pipe +diameter is too small the you're going + + align:start position:0% +diameter is too small the you're going + + + align:start position:0% +diameter is too small the you're going +to have frictional losses in the pipe + + align:start position:0% +to have frictional losses in the pipe + + + align:start position:0% +to have frictional losses in the pipe +that dominate and slow your water down + + align:start position:0% +that dominate and slow your water down + + + align:start position:0% +that dominate and slow your water down +so much that it's problematic. So that's + + align:start position:0% +so much that it's problematic. So that's + + + align:start position:0% +so much that it's problematic. So that's +another thing just to remember. um + + align:start position:0% +another thing just to remember. um + + + align:start position:0% +another thing just to remember. um +because it's tempting to use small + + align:start position:0% +because it's tempting to use small + + + align:start position:0% +because it's tempting to use small +diameter pipe um for a variety of + + align:start position:0% +diameter pipe um for a variety of + + + align:start position:0% +diameter pipe um for a variety of +reasons, but that's dangerous. Um + + align:start position:0% +reasons, but that's dangerous. Um + + + align:start position:0% +reasons, but that's dangerous. Um +so how do you figure out if a air of a + + align:start position:0% +so how do you figure out if a air of a + + + align:start position:0% +so how do you figure out if a air of a +river is appropriate for using um + + align:start position:0% +river is appropriate for using um + + + align:start position:0% +river is appropriate for using um +microhydro? So the two things you need + + align:start position:0% +microhydro? So the two things you need + + + align:start position:0% +microhydro? So the two things you need +to know again are flow and head. So the + + align:start position:0% +to know again are flow and head. So the + + + align:start position:0% +to know again are flow and head. So the +simplest method I can find for measuring + + align:start position:0% +simplest method I can find for measuring + + + align:start position:0% +simplest method I can find for measuring +flow um is called a float method. And + + align:start position:0% +flow um is called a float method. And + + + align:start position:0% +flow um is called a float method. And +you can imagine actually doing this in a + + align:start position:0% +you can imagine actually doing this in a + + + align:start position:0% +you can imagine actually doing this in a +river would be challenging. So it's not + + align:start position:0% +river would be challenging. So it's not + + + align:start position:0% +river would be challenging. So it's not +trivial, but it is possible. Um, so you + + align:start position:0% +trivial, but it is possible. Um, so you + + + align:start position:0% +trivial, but it is possible. Um, so you +mark about a 100 feet along a length + + align:start position:0% +mark about a 100 feet along a length + + + align:start position:0% +mark about a 100 feet along a length +that's ideally straight with uniform + + align:start position:0% +that's ideally straight with uniform + + + align:start position:0% +that's ideally straight with uniform +length and depth or width and depth. Um, + + align:start position:0% +length and depth or width and depth. Um, + + + align:start position:0% +length and depth or width and depth. Um, +which is comical to find in a river, + + align:start position:0% +which is comical to find in a river, + + + align:start position:0% +which is comical to find in a river, +right? Like I've never found a river + + align:start position:0% +right? Like I've never found a river + + + align:start position:0% +right? Like I've never found a river +that has 100 feet of uniform width and + + align:start position:0% +that has 100 feet of uniform width and + + + align:start position:0% +that has 100 feet of uniform width and +depth, but you do your best. Um, and + + align:start position:0% +depth, but you do your best. Um, and + + + align:start position:0% +depth, but you do your best. Um, and +then you calculate your cross-sectional + + align:start position:0% +then you calculate your cross-sectional + + + align:start position:0% +then you calculate your cross-sectional +area. A people usually model it as um a + + align:start position:0% +area. A people usually model it as um a + + + align:start position:0% +area. A people usually model it as um a +semicircle or a trapezoid or even just a + + align:start position:0% +semicircle or a trapezoid or even just a + + + align:start position:0% +semicircle or a trapezoid or even just a +rectangle. Um calculate that + + align:start position:0% +rectangle. Um calculate that + + + align:start position:0% +rectangle. Um calculate that +cross-sectional area. You place a marker + + align:start position:0% +cross-sectional area. You place a marker + + + align:start position:0% +cross-sectional area. You place a marker +at the start and end of your 100 ft and + + align:start position:0% +at the start and end of your 100 ft and + + + align:start position:0% +at the start and end of your 100 ft and +then you put floats in the river at the + + align:start position:0% +then you put floats in the river at the + + + align:start position:0% +then you put floats in the river at the +center of the stream um and time them to + + align:start position:0% +center of the stream um and time them to + + + align:start position:0% +center of the stream um and time them to +find out how long it takes for them to + + align:start position:0% +find out how long it takes for them to + + + align:start position:0% +find out how long it takes for them to +get from one end to the other. If you + + align:start position:0% +get from one end to the other. If you + + + align:start position:0% +get from one end to the other. If you +want to get complicated, you can uh put + + align:start position:0% +want to get complicated, you can uh put + + + align:start position:0% +want to get complicated, you can uh put +them all along a bunch of different + + align:start position:0% +them all along a bunch of different + + + align:start position:0% +them all along a bunch of different +points at different levels to worry + + align:start position:0% +points at different levels to worry + + + align:start position:0% +points at different levels to worry +about friction losses, but you don't + + align:start position:0% +about friction losses, but you don't + + + align:start position:0% +about friction losses, but you don't +actually have to do that to get a a + + align:start position:0% +actually have to do that to get a a + + + align:start position:0% +actually have to do that to get a a +ballpark measurement. You can just do it + + align:start position:0% +ballpark measurement. You can just do it + + + align:start position:0% +ballpark measurement. You can just do it +in the center. Um and so and good floats + + align:start position:0% +in the center. Um and so and good floats + + + align:start position:0% +in the center. Um and so and good floats +could be a tennis ball, could be an + + align:start position:0% +could be a tennis ball, could be an + + + align:start position:0% +could be a tennis ball, could be an +apple or something like that, whatever + + align:start position:0% +apple or something like that, whatever + + + align:start position:0% +apple or something like that, whatever +you can find that floats. Um, and then + + align:start position:0% +you can find that floats. Um, and then + + + align:start position:0% +you can find that floats. Um, and then +you do have to use a conversion factor + + align:start position:0% +you do have to use a conversion factor + + + align:start position:0% +you do have to use a conversion factor +because your water's flowing faster at + + align:start position:0% +because your water's flowing faster at + + + align:start position:0% +because your water's flowing faster at +the top of the water than in the the + + align:start position:0% +the top of the water than in the the + + + align:start position:0% +the top of the water than in the the +river than in the center because um + + align:start position:0% +river than in the center because um + + + align:start position:0% +river than in the center because um +because of the friction associated with + + align:start position:0% +because of the friction associated with + + + align:start position:0% +because of the friction associated with +the the base of the river. Uh, and so + + align:start position:0% +the the base of the river. Uh, and so + + + align:start position:0% +the the base of the river. Uh, and so +you have to um you can use a coefficient + + align:start position:0% +you have to um you can use a coefficient + + + align:start position:0% +you have to um you can use a coefficient +just to correct and then you get your + + align:start position:0% +just to correct and then you get your + + + align:start position:0% +just to correct and then you get your +flow rate. Yay. So that was a lot of + + align:start position:0% +flow rate. Yay. So that was a lot of + + + align:start position:0% +flow rate. Yay. So that was a lot of +work and all you have is a flow rate for + + align:start position:0% +work and all you have is a flow rate for + + + align:start position:0% +work and all you have is a flow rate for +one day and water varies like flow rate + + align:start position:0% +one day and water varies like flow rate + + + align:start position:0% +one day and water varies like flow rate +varies tremendously during the season. + + align:start position:0% +varies tremendously during the season. + + + align:start position:0% +varies tremendously during the season. +So again you can do your 10 10ear study + + align:start position:0% +So again you can do your 10 10ear study + + + align:start position:0% +So again you can do your 10 10ear study +or you can just um get some data on + + align:start position:0% +or you can just um get some data on + + + align:start position:0% +or you can just um get some data on +annual precipitation and when is the + + align:start position:0% +annual precipitation and when is the + + + align:start position:0% +annual precipitation and when is the +rainy season the dry season and do your + + align:start position:0% +rainy season the dry season and do your + + + align:start position:0% +rainy season the dry season and do your +best to estimate. Um but yeah so that's + + align:start position:0% +best to estimate. Um but yeah so that's + + + align:start position:0% +best to estimate. Um but yeah so that's +how you'd get your flow rate. + + align:start position:0% +how you'd get your flow rate. + + + align:start position:0% +how you'd get your flow rate. +And then in terms of head, the simplest + + align:start position:0% +And then in terms of head, the simplest + + + align:start position:0% +And then in terms of head, the simplest +method that again that I found that's + + align:start position:0% +method that again that I found that's + + + align:start position:0% +method that again that I found that's +used is you take a yard stick or a stick + + align:start position:0% +used is you take a yard stick or a stick + + + align:start position:0% +used is you take a yard stick or a stick +of known length. It doesn't need to be a + + align:start position:0% +of known length. It doesn't need to be a + + + align:start position:0% +of known length. It doesn't need to be a +yard stick. And you put on it just a + + align:start position:0% +yard stick. And you put on it just a + + + align:start position:0% +yard stick. And you put on it just a +tube that's clear that has the ends + + align:start position:0% +tube that's clear that has the ends + + + align:start position:0% +tube that's clear that has the ends +capped that's half full of water. And + + align:start position:0% +capped that's half full of water. And + + + align:start position:0% +capped that's half full of water. And +that's a really cheap level. Um, + + align:start position:0% +that's a really cheap level. Um, + + + align:start position:0% +that's a really cheap level. Um, +basically uh or you can get a real level + + align:start position:0% +basically uh or you can get a real level + + + align:start position:0% +basically uh or you can get a real level +if you have a real level. But if you + + align:start position:0% +if you have a real level. But if you + + + align:start position:0% +if you have a real level. But if you +don't have a real level, you can just + + align:start position:0% +don't have a real level, you can just + + + align:start position:0% +don't have a real level, you can just +use a cheap level. And then you + + align:start position:0% +use a cheap level. And then you + + + align:start position:0% +use a cheap level. And then you +hopefully with two people you put the + + align:start position:0% +hopefully with two people you put the + + + align:start position:0% +hopefully with two people you put the +stick at the bottom or the top and then + + align:start position:0% +stick at the bottom or the top and then + + + align:start position:0% +stick at the bottom or the top and then +just keep moving it over and over again + + align:start position:0% +just keep moving it over and over again + + + align:start position:0% +just keep moving it over and over again +until you measure your head which is a + + align:start position:0% +until you measure your head which is a + + + align:start position:0% +until you measure your head which is a +pain but people do it and it works. Um + + align:start position:0% +pain but people do it and it works. Um + + + align:start position:0% +pain but people do it and it works. Um +and actual surveying equipment is really + + align:start position:0% +and actual surveying equipment is really + + + align:start position:0% +and actual surveying equipment is really +expensive and so you're unlikely to have + + align:start position:0% +expensive and so you're unlikely to have + + + align:start position:0% +expensive and so you're unlikely to have +that in the field. So if a community + + align:start position:0% +that in the field. So if a community + + + align:start position:0% +that in the field. So if a community +partner asked about this you have a + + align:start position:0% +partner asked about this you have a + + + align:start position:0% +partner asked about this you have a +method to measure that's plausible. + + align:start position:0% +method to measure that's plausible. + + + align:start position:0% +method to measure that's plausible. +Yeah. Sorry. What the heck was the drop + + align:start position:0% +Yeah. Sorry. What the heck was the drop + + + align:start position:0% +Yeah. Sorry. What the heck was the drop +of the water? + + align:start position:0% +of the water? + + + align:start position:0% +of the water? +Right. So, you're putting this in the + + align:start position:0% +Right. So, you're putting this in the + + + align:start position:0% +Right. So, you're putting this in the +river + + align:start position:0% +river + + + align:start position:0% +river +this way. + + align:start position:0% +this way. + + + align:start position:0% +this way. +So, for the flow measurement, you're + + align:start position:0% +So, for the flow measurement, you're + + + align:start position:0% +So, for the flow measurement, you're +putting the the your floats in the water + + align:start position:0% +putting the the your floats in the water + + + align:start position:0% +putting the the your floats in the water +and watching how long it takes to get + + align:start position:0% +and watching how long it takes to get + + + align:start position:0% +and watching how long it takes to get +from one end to the other. And that'll + + align:start position:0% +from one end to the other. And that'll + + + align:start position:0% +from one end to the other. And that'll +give you a measure of flow. And then + + align:start position:0% +give you a measure of flow. And then + + + align:start position:0% +give you a measure of flow. And then +your river ideally + + align:start position:0% +your river ideally + + + align:start position:0% +your river ideally +is, let me get a picture instead of + + align:start position:0% +is, let me get a picture instead of + + + align:start position:0% +is, let me get a picture instead of +trying to draw a bad picture. + + align:start position:0% + + + + align:start position:0% + +So your river is hypothetically going + + align:start position:0% +So your river is hypothetically going + + + align:start position:0% +So your river is hypothetically going +down the mountain here and sort of doing + + align:start position:0% +down the mountain here and sort of doing + + + align:start position:0% +down the mountain here and sort of doing +a curve. And so you're saying, okay, + + align:start position:0% +a curve. And so you're saying, okay, + + + align:start position:0% +a curve. And so you're saying, okay, +well, I'm going to put my um weir and + + align:start position:0% +well, I'm going to put my um weir and + + + align:start position:0% +well, I'm going to put my um weir and +everything up here, and I'm going to put + + align:start position:0% +everything up here, and I'm going to put + + + align:start position:0% +everything up here, and I'm going to put +my uh location where I'm going to + + align:start position:0% +my uh location where I'm going to + + + align:start position:0% +my uh location where I'm going to +actually generate the power down here. + + align:start position:0% +actually generate the power down here. + + + align:start position:0% +actually generate the power down here. +So I need to calculate the height from + + align:start position:0% +So I need to calculate the height from + + + align:start position:0% +So I need to calculate the height from +right here to right here to get my head + + align:start position:0% +right here to right here to get my head + + + align:start position:0% +right here to right here to get my head +height. So now I need to, you know, very + + align:start position:0% +height. So now I need to, you know, very + + + align:start position:0% +height. So now I need to, you know, very +painfully go up the mountain in order to + + align:start position:0% +painfully go up the mountain in order to + + + align:start position:0% +painfully go up the mountain in order to +figure out exactly how high this + + align:start position:0% +figure out exactly how high this + + + align:start position:0% +figure out exactly how high this +distance is. Does that clear it up? + + align:start position:0% +distance is. Does that clear it up? + + + align:start position:0% +distance is. Does that clear it up? +Okay. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +So, that wraps up microhydro. Are there + + align:start position:0% +So, that wraps up microhydro. Are there + + + align:start position:0% +So, that wraps up microhydro. Are there +any questions + + align:start position:0% +any questions + + + align:start position:0% +any questions +in addition? + + align:start position:0% + + + + align:start position:0% + +Okay. So, trip. Uh I want to start + + align:start position:0% +Okay. So, trip. Uh I want to start + + + align:start position:0% +Okay. So, trip. Uh I want to start +talking about the trip uh and spend + + align:start position:0% +talking about the trip uh and spend + + + align:start position:0% +talking about the trip uh and spend +actually the rest of the time talking + + align:start position:0% +actually the rest of the time talking + + + align:start position:0% +actually the rest of the time talking +about it. So + + align:start position:0% +about it. So + + + align:start position:0% +about it. So +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +uh so let's do that. Um so one um change + + align:start position:0% +uh so let's do that. Um so one um change + + + align:start position:0% +uh so let's do that. Um so one um change +is that one group of students is going + + align:start position:0% +is that one group of students is going + + + align:start position:0% +is that one group of students is going +to go to El Salvador now instead of + + align:start position:0% +to go to El Salvador now instead of + + + align:start position:0% +to go to El Salvador now instead of +Nicaragua. And the reason for that is + + align:start position:0% +Nicaragua. And the reason for that is + + + align:start position:0% +Nicaragua. And the reason for that is +Amy Smith just came back from a trip to + + align:start position:0% +Amy Smith just came back from a trip to + + + align:start position:0% +Amy Smith just came back from a trip to +El Salvador where she found a community + + align:start position:0% +El Salvador where she found a community + + + align:start position:0% +El Salvador where she found a community +partner that's really interested in us + + align:start position:0% +partner that's really interested in us + + + align:start position:0% +partner that's really interested in us +and we think they're doing great work + + align:start position:0% +and we think they're doing great work + + + align:start position:0% +and we think they're doing great work +and are a solid connection and um so we + + align:start position:0% +and are a solid connection and um so we + + + align:start position:0% +and are a solid connection and um so we +decided to see if we could add Necar or + + align:start position:0% +decided to see if we could add Necar or + + + align:start position:0% +decided to see if we could add Necar or +El Salvador and we're able to in about 2 + + align:start position:0% +El Salvador and we're able to in about 2 + + + align:start position:0% +El Salvador and we're able to in about 2 +hours which is remarkably fast compared + + align:start position:0% +hours which is remarkably fast compared + + + align:start position:0% +hours which is remarkably fast compared +to like the months it takes to develop + + align:start position:0% +to like the months it takes to develop + + + align:start position:0% +to like the months it takes to develop +relations with other community partners. + + align:start position:0% +relations with other community partners. + + + align:start position:0% +relations with other community partners. +So hopefully that's a good sign. Um, and + + align:start position:0% +So hopefully that's a good sign. Um, and + + + align:start position:0% +So hopefully that's a good sign. Um, and +they're really interested in charcoal, + + align:start position:0% +they're really interested in charcoal, + + + align:start position:0% +they're really interested in charcoal, +which, um, is something you'll be + + align:start position:0% +which, um, is something you'll be + + + align:start position:0% +which, um, is something you'll be +trained in next week. So, it just seemed + + align:start position:0% +trained in next week. So, it just seemed + + + align:start position:0% +trained in next week. So, it just seemed +like a good fit. So, u, and you've + + align:start position:0% +like a good fit. So, u, and you've + + + align:start position:0% +like a good fit. So, u, and you've +already know about this group, so I'll + + align:start position:0% +already know about this group, so I'll + + + align:start position:0% +already know about this group, so I'll +talk to you offline if you want about + + align:start position:0% +talk to you offline if you want about + + + align:start position:0% +talk to you offline if you want about +it. Um, but yeah, so we're excited to be + + align:start position:0% +it. Um, but yeah, so we're excited to be + + + align:start position:0% +it. Um, but yeah, so we're excited to be +working with them. So, one group of + + align:start position:0% +working with them. So, one group of + + + align:start position:0% +working with them. So, one group of +students is going to be going to El + + align:start position:0% +students is going to be going to El + + + align:start position:0% +students is going to be going to El +Salvador and then two teams will be + + align:start position:0% +Salvador and then two teams will be + + + align:start position:0% +Salvador and then two teams will be +going to Nicaragua. Um, and El Salvador + + align:start position:0% +going to Nicaragua. Um, and El Salvador + + + align:start position:0% +going to Nicaragua. Um, and El Salvador +doesn't border Nicaragua, but it's + + align:start position:0% +doesn't border Nicaragua, but it's + + + align:start position:0% +doesn't border Nicaragua, but it's +pretty close. So, we're not that spread + + align:start position:0% +pretty close. So, we're not that spread + + + align:start position:0% +pretty close. So, we're not that spread +out yet. Uh we're not we're not + + align:start position:0% +out yet. Uh we're not we're not + + + align:start position:0% +out yet. Uh we're not we're not +approaching DAB development quite yet. + + align:start position:0% +approaching DAB development quite yet. + + + align:start position:0% +approaching DAB development quite yet. +So the teams are as follows. So OSO + + align:start position:0% +So the teams are as follows. So OSO + + + align:start position:0% +So the teams are as follows. So OSO +Phoenix will be going to um well Boss + + align:start position:0% +Phoenix will be going to um well Boss + + + align:start position:0% +Phoenix will be going to um well Boss +Roser and Briana will be going to OSO + + align:start position:0% +Roser and Briana will be going to OSO + + + align:start position:0% +Roser and Briana will be going to OSO +Phoenix and um Carter you'll be working + + align:start position:0% +Phoenix and um Carter you'll be working + + + align:start position:0% +Phoenix and um Carter you'll be working +with them um for the start of the term. + + align:start position:0% +with them um for the start of the term. + + + align:start position:0% +with them um for the start of the term. +Just I don't know if I've mentioned + + align:start position:0% +Just I don't know if I've mentioned + + + align:start position:0% +Just I don't know if I've mentioned +this, the teams that you go with to like + + align:start position:0% +this, the teams that you go with to like + + + align:start position:0% +this, the teams that you go with to like +and the projects you work on at for the + + align:start position:0% +and the projects you work on at for the + + + align:start position:0% +and the projects you work on at for the +for the spring break trip may or may not + + align:start position:0% +for the spring break trip may or may not + + + align:start position:0% +for the spring break trip may or may not +be what you end up working on + + align:start position:0% +be what you end up working on + + + align:start position:0% +be what you end up working on +afterwards. So what happens is the week + + align:start position:0% +afterwards. So what happens is the week + + + align:start position:0% +afterwards. So what happens is the week +after you get back from spring break, we + + align:start position:0% +after you get back from spring break, we + + + align:start position:0% +after you get back from spring break, we +sort of figure out what projects are + + align:start position:0% +sort of figure out what projects are + + + align:start position:0% +sort of figure out what projects are +going to happen. You tell me what you + + align:start position:0% +going to happen. You tell me what you + + + align:start position:0% +going to happen. You tell me what you +prefer to work on. And some students are + + align:start position:0% +prefer to work on. And some students are + + + align:start position:0% +prefer to work on. And some students are +really psyched to stay on the project + + align:start position:0% +really psyched to stay on the project + + + align:start position:0% +really psyched to stay on the project +that you went on spring break. And + + align:start position:0% +that you went on spring break. And + + + align:start position:0% +that you went on spring break. And +naturally, I'm going to try to make you + + align:start position:0% +naturally, I'm going to try to make you + + + align:start position:0% +naturally, I'm going to try to make you +or m make it possible for you to stay on + + align:start position:0% +or m make it possible for you to stay on + + + align:start position:0% +or m make it possible for you to stay on +the project you're really psyched about. + + align:start position:0% +the project you're really psyched about. + + + align:start position:0% +the project you're really psyched about. +Um, and especially if you're + + align:start position:0% +Um, and especially if you're + + + align:start position:0% +Um, and especially if you're +knowledgeable about it because you just + + align:start position:0% +knowledgeable about it because you just + + + align:start position:0% +knowledgeable about it because you just +went on a spring break drip, great. Um, + + align:start position:0% +went on a spring break drip, great. Um, + + + align:start position:0% +went on a spring break drip, great. Um, +but if for whatever reason you're like, + + align:start position:0% +but if for whatever reason you're like, + + + align:start position:0% +but if for whatever reason you're like, +you know what, I can't stand Phoenix. I + + align:start position:0% +you know what, I can't stand Phoenix. I + + + align:start position:0% +you know what, I can't stand Phoenix. I +don't want to work with them or any of + + align:start position:0% +don't want to work with them or any of + + + align:start position:0% +don't want to work with them or any of +their projects ever again, I'm not going + + align:start position:0% +their projects ever again, I'm not going + + + align:start position:0% +their projects ever again, I'm not going +to force you. I'm hopefully not going to + + align:start position:0% +to force you. I'm hopefully not going to + + + align:start position:0% +to force you. I'm hopefully not going to +be have to force you to stay on that. + + align:start position:0% +be have to force you to stay on that. + + + align:start position:0% +be have to force you to stay on that. +So, there may be a little shuffling. So, + + align:start position:0% +So, there may be a little shuffling. So, + + + align:start position:0% +So, there may be a little shuffling. So, +especially the people who aren't + + align:start position:0% +especially the people who aren't + + + align:start position:0% +especially the people who aren't +traveling, um, there's variation. And + + align:start position:0% +traveling, um, there's variation. And + + + align:start position:0% +traveling, um, there's variation. And +I'm pretty sure Eric has dropped the + + align:start position:0% +I'm pretty sure Eric has dropped the + + + align:start position:0% +I'm pretty sure Eric has dropped the +class. So, but if he hasn't, um, he, uh, + + align:start position:0% +class. So, but if he hasn't, um, he, uh, + + + align:start position:0% +class. So, but if he hasn't, um, he, uh, +would be on this group. So, the projects + + align:start position:0% +would be on this group. So, the projects + + + align:start position:0% +would be on this group. So, the projects +that you're going to be working on, um, + + align:start position:0% +that you're going to be working on, um, + + + align:start position:0% +that you're going to be working on, um, +one is, uh, last year the students + + align:start position:0% +one is, uh, last year the students + + + align:start position:0% +one is, uh, last year the students +worked on the OJ bag sealer. And so, one + + align:start position:0% +worked on the OJ bag sealer. And so, one + + + align:start position:0% +worked on the OJ bag sealer. And so, one +thing is delivering that bag sealer, + + align:start position:0% +thing is delivering that bag sealer, + + + align:start position:0% +thing is delivering that bag sealer, +which ideally means reading the final + + align:start position:0% +which ideally means reading the final + + + align:start position:0% +which ideally means reading the final +report from last year and learning how + + align:start position:0% +report from last year and learning how + + + align:start position:0% +report from last year and learning how +it works so you can show it to us + + align:start position:0% +it works so you can show it to us + + + align:start position:0% +it works so you can show it to us +Phoenix staff when you get there. Um, + + align:start position:0% +Phoenix staff when you get there. Um, + + + align:start position:0% +Phoenix staff when you get there. Um, +and that's sort of like the side + + align:start position:0% +and that's sort of like the side + + + align:start position:0% +and that's sort of like the side +servicey project as opposed to the + + align:start position:0% +servicey project as opposed to the + + + align:start position:0% +servicey project as opposed to the +investigative parts of the work. And + + align:start position:0% +investigative parts of the work. And + + + align:start position:0% +investigative parts of the work. And +then the one, two, and three are the + + align:start position:0% +then the one, two, and three are the + + + align:start position:0% +then the one, two, and three are the +projects that you're going to be + + align:start position:0% +projects that you're going to be + + + align:start position:0% +projects that you're going to be +investigating. So one is the + + align:start position:0% +investigating. So one is the + + + align:start position:0% +investigating. So one is the +biodigestertor, which is um they have + + align:start position:0% +biodigestertor, which is um they have + + + align:start position:0% +biodigestertor, which is um they have +biodigesttors and they want to be able + + align:start position:0% +biodigesttors and they want to be able + + + align:start position:0% +biodigesttors and they want to be able +to mix internally um so that the slooh + + align:start position:0% +to mix internally um so that the slooh + + + align:start position:0% +to mix internally um so that the slooh +um provides better digestion. Um and + + align:start position:0% +um provides better digestion. Um and + + + align:start position:0% +um provides better digestion. Um and +they're looking at either hand or + + align:start position:0% +they're looking at either hand or + + + align:start position:0% +they're looking at either hand or +bicycle power. Um and they have both + + align:start position:0% +bicycle power. Um and they have both + + + align:start position:0% +bicycle power. Um and they have both +concrete and plastic biodigesttors. + + align:start position:0% +concrete and plastic biodigesttors. + + + align:start position:0% +concrete and plastic biodigesttors. +Uh the second is a feed chopper + + align:start position:0% +Uh the second is a feed chopper + + + align:start position:0% +Uh the second is a feed chopper +mechanism using bicycle power and I can + + align:start position:0% +mechanism using bicycle power and I can + + + align:start position:0% +mechanism using bicycle power and I can +show you video of the feed chopper. And + + align:start position:0% +show you video of the feed chopper. And + + + align:start position:0% +show you video of the feed chopper. And +third is a washing machine. DAB actually + + align:start position:0% +third is a washing machine. DAB actually + + + align:start position:0% +third is a washing machine. DAB actually +has done a lot of work on washing + + align:start position:0% +has done a lot of work on washing + + + align:start position:0% +has done a lot of work on washing +machines and so this is one area where + + align:start position:0% +machines and so this is one area where + + + align:start position:0% +machines and so this is one area where +you can learn about the existing washing + + align:start position:0% +you can learn about the existing washing + + + align:start position:0% +you can learn about the existing washing +machines designs and then potentially + + align:start position:0% +machines designs and then potentially + + + align:start position:0% +machines designs and then potentially +bring them down and even build one while + + align:start position:0% +bring them down and even build one while + + + align:start position:0% +bring them down and even build one while +you're there um is a possibility. + + align:start position:0% +you're there um is a possibility. + + + align:start position:0% +you're there um is a possibility. +Um, and I at the end of going through + + align:start position:0% +Um, and I at the end of going through + + + align:start position:0% +Um, and I at the end of going through +all this, I'm going to + + align:start position:0% +all this, I'm going to + + + align:start position:0% +all this, I'm going to +talk about what you need to do with this + + align:start position:0% +talk about what you need to do with this + + + align:start position:0% +talk about what you need to do with this +information in the next few weeks. And + + align:start position:0% +information in the next few weeks. And + + + align:start position:0% +information in the next few weeks. And +then um, you'll have time to work with + + align:start position:0% +then um, you'll have time to work with + + + align:start position:0% +then um, you'll have time to work with +your teams, talk to me a little bit, + + align:start position:0% +your teams, talk to me a little bit, + + + align:start position:0% +your teams, talk to me a little bit, +your mentor if will show up at two to + + align:start position:0% +your mentor if will show up at two to + + + align:start position:0% +your mentor if will show up at two to +work with you a little bit on all of + + align:start position:0% +work with you a little bit on all of + + + align:start position:0% +work with you a little bit on all of +this. Um, + + align:start position:0% +this. Um, + + + align:start position:0% +this. Um, +the second group of one, Jessica, + + align:start position:0% +the second group of one, Jessica, + + + align:start position:0% +the second group of one, Jessica, +Elizabeth, Vivian, + + align:start position:0% +Elizabeth, Vivian, + + + align:start position:0% +Elizabeth, Vivian, +Sid, and Kurt is going to group of + + align:start position:0% +Sid, and Kurt is going to group of + + + align:start position:0% +Sid, and Kurt is going to group of +Phoenix. Um, Amelia Servey is your trip + + align:start position:0% +Phoenix. Um, Amelia Servey is your trip + + + align:start position:0% +Phoenix. Um, Amelia Servey is your trip +leader. She took the class this class + + align:start position:0% +leader. She took the class this class + + + align:start position:0% +leader. She took the class this class +last year um and did a summers + + align:start position:0% +last year um and did a summers + + + align:start position:0% +last year um and did a summers +fellowship at Group of Phoenix and so + + align:start position:0% +fellowship at Group of Phoenix and so + + + align:start position:0% +fellowship at Group of Phoenix and so +she knows them pretty well. Um + + align:start position:0% +she knows them pretty well. Um + + + align:start position:0% +she knows them pretty well. Um +and she's a grad student now. Um and so + + align:start position:0% +and she's a grad student now. Um and so + + + align:start position:0% +and she's a grad student now. Um and so +the projects are number one they're + + align:start position:0% +the projects are number one they're + + + align:start position:0% +the projects are number one they're +really interested in charcoal both um + + align:start position:0% +really interested in charcoal both um + + + align:start position:0% +really interested in charcoal both um +the stove and a stove project that was + + align:start position:0% +the stove and a stove project that was + + + align:start position:0% +the stove and a stove project that was +worked on last year on making charcoal + + align:start position:0% +worked on last year on making charcoal + + + align:start position:0% +worked on last year on making charcoal +generally. So working with them on + + align:start position:0% +generally. So working with them on + + + align:start position:0% +generally. So working with them on +charcoal. Um two solar cell phone + + align:start position:0% +charcoal. Um two solar cell phone + + + align:start position:0% +charcoal. Um two solar cell phone +chargers um to develop more affordable + + align:start position:0% +chargers um to develop more affordable + + + align:start position:0% +chargers um to develop more affordable +um version for production. Um they + + align:start position:0% +um version for production. Um they + + + align:start position:0% +um version for production. Um they +currently are working on developing a + + align:start position:0% +currently are working on developing a + + + align:start position:0% +currently are working on developing a +cell phone charger. I can show you the + + align:start position:0% +cell phone charger. I can show you the + + + align:start position:0% +cell phone charger. I can show you the +battery charger they have and it's + + align:start position:0% +battery charger they have and it's + + + align:start position:0% +battery charger they have and it's +pretty rudimentary and partly that's a + + align:start position:0% +pretty rudimentary and partly that's a + + + align:start position:0% +pretty rudimentary and partly that's a +function of their poverty and + + align:start position:0% +function of their poverty and + + + align:start position:0% +function of their poverty and +availability of materials but there is + + align:start position:0% +availability of materials but there is + + + align:start position:0% +availability of materials but there is +opportunity to improve it. Um and they + + align:start position:0% +opportunity to improve it. Um and they + + + align:start position:0% +opportunity to improve it. Um and they +would like to have a really good solar + + align:start position:0% +would like to have a really good solar + + + align:start position:0% +would like to have a really good solar +cell phone charger. Um, and then three, + + align:start position:0% +cell phone charger. Um, and then three, + + + align:start position:0% +cell phone charger. Um, and then three, +they have a solar cooker that's really + + align:start position:0% +they have a solar cooker that's really + + + align:start position:0% +they have a solar cooker that's really +expensive. I'll talk about it next week + + align:start position:0% +expensive. I'll talk about it next week + + + align:start position:0% +expensive. I'll talk about it next week +some. Um, and there's a lot of + + align:start position:0% +some. Um, and there's a lot of + + + align:start position:0% +some. Um, and there's a lot of +opportunity for improvement there to + + align:start position:0% +opportunity for improvement there to + + + align:start position:0% +opportunity for improvement there to +make it more affordable to produce and + + align:start position:0% +make it more affordable to produce and + + + align:start position:0% +make it more affordable to produce and +more aesthetically pleasing and um, more + + align:start position:0% +more aesthetically pleasing and um, more + + + align:start position:0% +more aesthetically pleasing and um, more +functional too. Uh, we have some data on + + align:start position:0% +functional too. Uh, we have some data on + + + align:start position:0% +functional too. Uh, we have some data on +there. And then the third group um, in + + align:start position:0% +there. And then the third group um, in + + + align:start position:0% +there. And then the third group um, in +El Salvador is called Asoproar. And so + + align:start position:0% +El Salvador is called Asoproar. And so + + + align:start position:0% +El Salvador is called Asoproar. And so +Benzy, Missy, and Julia will be going + + align:start position:0% +Benzy, Missy, and Julia will be going + + + align:start position:0% +Benzy, Missy, and Julia will be going +there. and Adrian and Benji, you'll be + + align:start position:0% +there. and Adrian and Benji, you'll be + + + align:start position:0% +there. and Adrian and Benji, you'll be +on that team, too. Um, and so the + + align:start position:0% +on that team, too. Um, and so the + + + align:start position:0% +on that team, too. Um, and so the +projects, so they're interested in a + + align:start position:0% +projects, so they're interested in a + + + align:start position:0% +projects, so they're interested in a +charcoal training, and that again, so + + align:start position:0% +charcoal training, and that again, so + + + align:start position:0% +charcoal training, and that again, so +that would be sort of the service part. + + align:start position:0% +that would be sort of the service part. + + + align:start position:0% +that would be sort of the service part. +Um, better ventilation for smoke in the + + align:start position:0% +Um, better ventilation for smoke in the + + + align:start position:0% +Um, better ventilation for smoke in the +home is one area of interest we believe. + + align:start position:0% +home is one area of interest we believe. + + + align:start position:0% +home is one area of interest we believe. +Um, secondly is we think charcoal stoves + + align:start position:0% +Um, secondly is we think charcoal stoves + + + align:start position:0% +Um, secondly is we think charcoal stoves +will be relevant in El Salvador based on + + align:start position:0% +will be relevant in El Salvador based on + + + align:start position:0% +will be relevant in El Salvador based on +what I remember of my trip there. I'm + + align:start position:0% +what I remember of my trip there. I'm + + + align:start position:0% +what I remember of my trip there. I'm +pretty sure they cook with adobe stoves + + align:start position:0% +pretty sure they cook with adobe stoves + + + align:start position:0% +pretty sure they cook with adobe stoves +just like they do in Nicaragua. So, + + align:start position:0% +just like they do in Nicaragua. So, + + + align:start position:0% +just like they do in Nicaragua. So, +it'll be relevant to work on the stove + + align:start position:0% +it'll be relevant to work on the stove + + + align:start position:0% +it'll be relevant to work on the stove +project there. And then potentially + + align:start position:0% +project there. And then potentially + + + align:start position:0% +project there. And then potentially +better lighting um opportunities, too. + + align:start position:0% +better lighting um opportunities, too. + + + align:start position:0% +better lighting um opportunities, too. +Um and a lot of these are sort of have a + + align:start position:0% +Um and a lot of these are sort of have a + + + align:start position:0% +Um and a lot of these are sort of have a +bit of an architectural bent, which we + + align:start position:0% +bit of an architectural bent, which we + + + align:start position:0% +bit of an architectural bent, which we +haven't focused on much in this class, + + align:start position:0% +haven't focused on much in this class, + + + align:start position:0% +haven't focused on much in this class, +but Julia is a grad student + + align:start position:0% +but Julia is a grad student + + + align:start position:0% +but Julia is a grad student +architecture, so she's going to help um + + align:start position:0% +architecture, so she's going to help um + + + align:start position:0% +architecture, so she's going to help um +with that aspect of things. Um guess + + align:start position:0% +with that aspect of things. Um guess + + + align:start position:0% +with that aspect of things. Um guess +what? Uh uh so yeah, so we're excited + + align:start position:0% +what? Uh uh so yeah, so we're excited + + + align:start position:0% +what? Uh uh so yeah, so we're excited +about that project and thanks for the + + align:start position:0% +about that project and thanks for the + + + align:start position:0% +about that project and thanks for the +people who are rolling with just being + + align:start position:0% +people who are rolling with just being + + + align:start position:0% +people who are rolling with just being +sent to a new country with very little + + align:start position:0% +sent to a new country with very little + + + align:start position:0% +sent to a new country with very little +notice. Um so what do you have to do + + align:start position:0% +notice. Um so what do you have to do + + + align:start position:0% +notice. Um so what do you have to do +with all this? Um, so right now and by + + align:start position:0% +with all this? Um, so right now and by + + + align:start position:0% +with all this? Um, so right now and by +right now I mean in the next two hours. + + align:start position:0% +right now I mean in the next two hours. + + + align:start position:0% +right now I mean in the next two hours. +Um, talk to me um, and do some + + align:start position:0% +Um, talk to me um, and do some + + + align:start position:0% +Um, talk to me um, and do some +brainstorming of ideas. + + align:start position:0% +brainstorming of ideas. + + + align:start position:0% +brainstorming of ideas. +Um, and your deliverable for this step + + align:start position:0% +Um, and your deliverable for this step + + + align:start position:0% +Um, and your deliverable for this step +is two annotated pictures from each team + + align:start position:0% +is two annotated pictures from each team + + + align:start position:0% +is two annotated pictures from each team +member. Um, and so there's a lot of + + align:start position:0% +member. Um, and so there's a lot of + + + align:start position:0% +member. Um, and so there's a lot of +different deadlines for all these + + align:start position:0% +different deadlines for all these + + + align:start position:0% +different deadlines for all these +different things. I'm just trying to + + align:start position:0% +different things. I'm just trying to + + + align:start position:0% +different things. I'm just trying to +help you get through the next couple of + + align:start position:0% +help you get through the next couple of + + + align:start position:0% +help you get through the next couple of +weeks in a way that you actually get + + align:start position:0% +weeks in a way that you actually get + + + align:start position:0% +weeks in a way that you actually get +output and don't save it all to the last + + align:start position:0% +output and don't save it all to the last + + + align:start position:0% +output and don't save it all to the last +night, which will lead to really weak + + align:start position:0% +night, which will lead to really weak + + + align:start position:0% +night, which will lead to really weak +both packing and um help for your + + align:start position:0% +both packing and um help for your + + + align:start position:0% +both packing and um help for your +community partner. Um so this is all + + align:start position:0% +community partner. Um so this is all + + + align:start position:0% +community partner. Um so this is all +hopefully in preparation so that you can + + align:start position:0% +hopefully in preparation so that you can + + + align:start position:0% +hopefully in preparation so that you can +maximize the value to you and your + + align:start position:0% +maximize the value to you and your + + + align:start position:0% +maximize the value to you and your +community partner for the spring break + + align:start position:0% +community partner for the spring break + + + align:start position:0% +community partner for the spring break +trip. Um, and for people who aren't + + align:start position:0% +trip. Um, and for people who aren't + + + align:start position:0% +trip. Um, and for people who aren't +traveling, you're helping make sure + + align:start position:0% +traveling, you're helping make sure + + + align:start position:0% +traveling, you're helping make sure +they're maximizing their their work and + + align:start position:0% +they're maximizing their their work and + + + align:start position:0% +they're maximizing their their work and +it's also getting you prepared for doing + + align:start position:0% +it's also getting you prepared for doing + + + align:start position:0% +it's also getting you prepared for doing +the project work after the spring break. + + align:start position:0% +the project work after the spring break. + + + align:start position:0% +the project work after the spring break. +So, I don't think this is busy work for + + align:start position:0% +So, I don't think this is busy work for + + + align:start position:0% +So, I don't think this is busy work for +you in any way. Um, + + align:start position:0% +you in any way. Um, + + + align:start position:0% +you in any way. Um, +so, so that's one is doing a + + align:start position:0% +so, so that's one is doing a + + + align:start position:0% +so, so that's one is doing a +brainstorming effort and I'm going to + + align:start position:0% +brainstorming effort and I'm going to + + + align:start position:0% +brainstorming effort and I'm going to +talk a little bit about brainstorming in + + align:start position:0% +talk a little bit about brainstorming in + + + align:start position:0% +talk a little bit about brainstorming in +a minute. So, you have some guidelines + + align:start position:0% +a minute. So, you have some guidelines + + + align:start position:0% +a minute. So, you have some guidelines +there. Yeah. + + align:start position:0% +there. Yeah. + + + align:start position:0% +there. Yeah. +I pictures you mean find examples of + + align:start position:0% +I pictures you mean find examples of + + + align:start position:0% +I pictures you mean find examples of +existing technology or like do sketches? + + align:start position:0% +existing technology or like do sketches? + + + align:start position:0% +existing technology or like do sketches? +No, just sketches. So, yeah. So, + + align:start position:0% +No, just sketches. So, yeah. So, + + + align:start position:0% +No, just sketches. So, yeah. So, +basically, I'll I'll show you this in a + + align:start position:0% +basically, I'll I'll show you this in a + + + align:start position:0% +basically, I'll I'll show you this in a +minute, but when you do a brainstorm, + + align:start position:0% +minute, but when you do a brainstorm, + + + align:start position:0% +minute, but when you do a brainstorm, +like if I was brainstorming wind + + align:start position:0% +like if I was brainstorming wind + + + align:start position:0% +like if I was brainstorming wind +turbines, I might do a picture that + + align:start position:0% +turbines, I might do a picture that + + + align:start position:0% +turbines, I might do a picture that +looks like that, you know, like takes me + + align:start position:0% +looks like that, you know, like takes me + + + align:start position:0% +looks like that, you know, like takes me +10 seconds to draw tops. Um, and for the + + align:start position:0% +10 seconds to draw tops. Um, and for the + + + align:start position:0% +10 seconds to draw tops. Um, and for the +pictures you and that would be really + + align:start position:0% +pictures you and that would be really + + + align:start position:0% +pictures you and that would be really +appropriate in a brainstorming session + + align:start position:0% +appropriate in a brainstorming session + + + align:start position:0% +appropriate in a brainstorming session +for the pictures you turn in, I'd want + + align:start position:0% +for the pictures you turn in, I'd want + + + align:start position:0% +for the pictures you turn in, I'd want +it to be a little more refined so that + + align:start position:0% +it to be a little more refined so that + + + align:start position:0% +it to be a little more refined so that +um, this is everything is drawn a little + + align:start position:0% +um, this is everything is drawn a little + + + align:start position:0% +um, this is everything is drawn a little +bit more carefully. Um, there's a few + + align:start position:0% +bit more carefully. Um, there's a few + + + align:start position:0% +bit more carefully. Um, there's a few +more elements that actually make this a + + align:start position:0% +more elements that actually make this a + + + align:start position:0% +more elements that actually make this a +real device rather than just something + + align:start position:0% +real device rather than just something + + + align:start position:0% +real device rather than just something +disembodied in air, whatever is + + align:start position:0% +disembodied in air, whatever is + + + align:start position:0% +disembodied in air, whatever is +appropriate. Um, + + align:start position:0% +appropriate. Um, + + + align:start position:0% +appropriate. Um, +not many if any of you are artists, + + align:start position:0% +not many if any of you are artists, + + + align:start position:0% +not many if any of you are artists, +right, or techn graphic designers. And + + align:start position:0% +right, or techn graphic designers. And + + + align:start position:0% +right, or techn graphic designers. And +so I'm not looking for an amazing sketch + + align:start position:0% +so I'm not looking for an amazing sketch + + + align:start position:0% +so I'm not looking for an amazing sketch +that was done by a graphic designer or + + align:start position:0% +that was done by a graphic designer or + + + align:start position:0% +that was done by a graphic designer or +artist. Um, I'm not one either. But um, + + align:start position:0% +artist. Um, I'm not one either. But um, + + + align:start position:0% +artist. Um, I'm not one either. But um, +if you just draw relatively slowly and + + align:start position:0% +if you just draw relatively slowly and + + + align:start position:0% +if you just draw relatively slowly and +carefully, you know, maybe do a couple + + align:start position:0% +carefully, you know, maybe do a couple + + + align:start position:0% +carefully, you know, maybe do a couple +tries, you should be able to get a + + align:start position:0% +tries, you should be able to get a + + + align:start position:0% +tries, you should be able to get a +drawing that looks decent enough that + + align:start position:0% +drawing that looks decent enough that + + + align:start position:0% +drawing that looks decent enough that +it's understandable, which is all I'm + + align:start position:0% +it's understandable, which is all I'm + + + align:start position:0% +it's understandable, which is all I'm +really looking for. + + align:start position:0% +really looking for. + + + align:start position:0% +really looking for. +Um, so then the second thing is a + + align:start position:0% +Um, so then the second thing is a + + + align:start position:0% +Um, so then the second thing is a +literature search on the topic, which + + align:start position:0% +literature search on the topic, which + + + align:start position:0% +literature search on the topic, which +you may have time for as well, but I + + align:start position:0% +you may have time for as well, but I + + + align:start position:0% +you may have time for as well, but I +want you to do a brainstorm initially + + align:start position:0% +want you to do a brainstorm initially + + + align:start position:0% +want you to do a brainstorm initially +just to sort of get creative before you + + align:start position:0% +just to sort of get creative before you + + + align:start position:0% +just to sort of get creative before you +know what's out there necessarily. Um so + + align:start position:0% +know what's out there necessarily. Um so + + + align:start position:0% +know what's out there necessarily. Um so +then so that's why we're doing the + + align:start position:0% +then so that's why we're doing the + + + align:start position:0% +then so that's why we're doing the +brainstorm one brainstorming first but + + align:start position:0% +brainstorm one brainstorming first but + + + align:start position:0% +brainstorm one brainstorming first but +then a second set which you may have + + align:start position:0% +then a second set which you may have + + + align:start position:0% +then a second set which you may have +time to do some today if you brought + + align:start position:0% +time to do some today if you brought + + + align:start position:0% +time to do some today if you brought +laptops or what have you um + + align:start position:0% +laptops or what have you um + + + align:start position:0% +laptops or what have you um +is to get some information on what's out + + align:start position:0% +is to get some information on what's out + + + align:start position:0% +is to get some information on what's out +there um so that you're more informed uh + + align:start position:0% +there um so that you're more informed uh + + + align:start position:0% +there um so that you're more informed uh +about whatever you need to be u whatever + + align:start position:0% +about whatever you need to be u whatever + + + align:start position:0% +about whatever you need to be u whatever +your project is um there's and so the + + align:start position:0% +your project is um there's and so the + + + align:start position:0% +your project is um there's and so the +what I think would be a good deliverable + + align:start position:0% +what I think would be a good deliverable + + + align:start position:0% +what I think would be a good deliverable +for this is an annotated bibliography + + align:start position:0% +for this is an annotated bibliography + + + align:start position:0% +for this is an annotated bibliography +Um, and there's guidelines right there + + align:start position:0% +Um, and there's guidelines right there + + + align:start position:0% +Um, and there's guidelines right there +on how to write an annotated + + align:start position:0% +on how to write an annotated + + + align:start position:0% +on how to write an annotated +bibliography. + + align:start position:0% +bibliography. + + + align:start position:0% +bibliography. +The guidelines for annotated + + align:start position:0% +The guidelines for annotated + + + align:start position:0% +The guidelines for annotated +biblographies are generally on the like + + align:start position:0% +biblographies are generally on the like + + + align:start position:0% +biblographies are generally on the like +liberal arts side of things. And so they + + align:start position:0% +liberal arts side of things. And so they + + + align:start position:0% +liberal arts side of things. And so they +talk about summarizing what was the + + align:start position:0% +talk about summarizing what was the + + + align:start position:0% +talk about summarizing what was the +content, reflecting on whether it was + + align:start position:0% +content, reflecting on whether it was + + + align:start position:0% +content, reflecting on whether it was +useful and assessing the quality of the + + align:start position:0% +useful and assessing the quality of the + + + align:start position:0% +useful and assessing the quality of the +source. And all those things are are + + align:start position:0% +source. And all those things are are + + + align:start position:0% +source. And all those things are are +good things, but basically I want you to + + align:start position:0% +good things, but basically I want you to + + + align:start position:0% +good things, but basically I want you to +focus on summarizing what was there and + + align:start position:0% +focus on summarizing what was there and + + + align:start position:0% +focus on summarizing what was there and +reflecting on how it's relevant to your + + align:start position:0% +reflecting on how it's relevant to your + + + align:start position:0% +reflecting on how it's relevant to your +project for for each annotation and + + align:start position:0% +project for for each annotation and + + + align:start position:0% +project for for each annotation and +assessing the quality of the source. If + + align:start position:0% +assessing the quality of the source. If + + + align:start position:0% +assessing the quality of the source. If +it's a crappy source, just don't include + + align:start position:0% +it's a crappy source, just don't include + + + align:start position:0% +it's a crappy source, just don't include +it in the bibliography. And if it's a + + align:start position:0% +it in the bibliography. And if it's a + + + align:start position:0% +it in the bibliography. And if it's a +great source, include it. Um, and if + + align:start position:0% +great source, include it. Um, and if + + + align:start position:0% +great source, include it. Um, and if +there is something to assess that you + + align:start position:0% +there is something to assess that you + + + align:start position:0% +there is something to assess that you +want to note, don't don't hesitate to, + + align:start position:0% +want to note, don't don't hesitate to, + + + align:start position:0% +want to note, don't don't hesitate to, +but otherwise, you don't really have to + + align:start position:0% +but otherwise, you don't really have to + + + align:start position:0% +but otherwise, you don't really have to +time spend time assessing the source um + + align:start position:0% +time spend time assessing the source um + + + align:start position:0% +time spend time assessing the source um +in a written form. Um, so third is + + align:start position:0% +in a written form. Um, so third is + + + align:start position:0% +in a written form. Um, so third is +developing project specifications. And + + align:start position:0% +developing project specifications. And + + + align:start position:0% +developing project specifications. And +29 does a really nice job of defining + + align:start position:0% +29 does a really nice job of defining + + + align:start position:0% +29 does a really nice job of defining +what a project specification is. So I've + + align:start position:0% +what a project specification is. So I've + + + align:start position:0% +what a project specification is. So I've +provided links to their lecture and + + align:start position:0% +provided links to their lecture and + + + align:start position:0% +provided links to their lecture and +examples. Um, and so you're going to + + align:start position:0% +examples. Um, and so you're going to + + + align:start position:0% +examples. Um, and so you're going to +provide project specifications for each + + align:start position:0% +provide project specifications for each + + + align:start position:0% +provide project specifications for each +project using the 209 format. So that + + align:start position:0% +project using the 209 format. So that + + + align:start position:0% +project using the 209 format. So that +would mean an attribute, a metric, a + + align:start position:0% +would mean an attribute, a metric, a + + + align:start position:0% +would mean an attribute, a metric, a +unit, and a value. And you'll see the + + align:start position:0% +unit, and a value. And you'll see the + + + align:start position:0% +unit, and a value. And you'll see the +definitions there. The value is an + + align:start position:0% +definitions there. The value is an + + + align:start position:0% +definitions there. The value is an +actual number. Like it needs like a + + align:start position:0% +actual number. Like it needs like a + + + align:start position:0% +actual number. Like it needs like a +three or a seven. And a lot of those + + align:start position:0% +three or a seven. And a lot of those + + + align:start position:0% +three or a seven. And a lot of those +numbers you probably won't be able to + + align:start position:0% +numbers you probably won't be able to + + + align:start position:0% +numbers you probably won't be able to +fill in until after your trip. And + + align:start position:0% +fill in until after your trip. And + + + align:start position:0% +fill in until after your trip. And +that's fine. But I would, what I would + + align:start position:0% +that's fine. But I would, what I would + + + align:start position:0% +that's fine. But I would, what I would +like you to do is come up with a best + + align:start position:0% +like you to do is come up with a best + + + align:start position:0% +like you to do is come up with a best +guess. Even if it's a range of a couple + + align:start position:0% +guess. Even if it's a range of a couple + + + align:start position:0% +guess. Even if it's a range of a couple +of orders of magnitude, come with the + + align:start position:0% +of orders of magnitude, come with the + + + align:start position:0% +of orders of magnitude, come with the +best guess so that when you talk to your + + align:start position:0% +best guess so that when you talk to your + + + align:start position:0% +best guess so that when you talk to your +community partner who often don't have a + + align:start position:0% +community partner who often don't have a + + + align:start position:0% +community partner who often don't have a +lot of um comfort with numbers and may + + align:start position:0% +lot of um comfort with numbers and may + + + align:start position:0% +lot of um comfort with numbers and may +give you really wacky numbers, if + + align:start position:0% +give you really wacky numbers, if + + + align:start position:0% +give you really wacky numbers, if +they're giving you numbers that are + + align:start position:0% +they're giving you numbers that are + + + align:start position:0% +they're giving you numbers that are +completely different from what you're + + align:start position:0% +completely different from what you're + + + align:start position:0% +completely different from what you're +expecting, that's a really good + + align:start position:0% +expecting, that's a really good + + + align:start position:0% +expecting, that's a really good +indicator to you that you need to keep + + align:start position:0% +indicator to you that you need to keep + + + align:start position:0% +indicator to you that you need to keep +asking questions so that either you + + align:start position:0% +asking questions so that either you + + + align:start position:0% +asking questions so that either you +learn that your assumptions are totally + + align:start position:0% +learn that your assumptions are totally + + + align:start position:0% +learn that your assumptions are totally +off, um which is a really important + + align:start position:0% +off, um which is a really important + + + align:start position:0% +off, um which is a really important +thing to learn, or that your community + + align:start position:0% +thing to learn, or that your community + + + align:start position:0% +thing to learn, or that your community +partner isn't really understanding the + + align:start position:0% +partner isn't really understanding the + + + align:start position:0% +partner isn't really understanding the +question or doesn't have the um + + align:start position:0% +question or doesn't have the um + + + align:start position:0% +question or doesn't have the um +educational background around to be able + + align:start position:0% +educational background around to be able + + + align:start position:0% +educational background around to be able +to give you a useful number and you have + + align:start position:0% +to give you a useful number and you have + + + align:start position:0% +to give you a useful number and you have +to work in a few different guises to + + align:start position:0% +to work in a few different guises to + + + align:start position:0% +to work in a few different guises to +actually get to that number and we'll + + align:start position:0% +actually get to that number and we'll + + + align:start position:0% +actually get to that number and we'll +talk about that on the trip prep week of + + align:start position:0% +talk about that on the trip prep week of + + + align:start position:0% +talk about that on the trip prep week of +how you actually do that process of + + align:start position:0% +how you actually do that process of + + + align:start position:0% +how you actually do that process of +getting that information. + + align:start position:0% + + + + align:start position:0% + +Um, and then the next aspects are doing + + align:start position:0% +Um, and then the next aspects are doing + + + align:start position:0% +Um, and then the next aspects are doing +a second brainstorm. Um, and it's up to + + align:start position:0% +a second brainstorm. Um, and it's up to + + + align:start position:0% +a second brainstorm. Um, and it's up to +you as a team if you want to do this in + + align:start position:0% +you as a team if you want to do this in + + + align:start position:0% +you as a team if you want to do this in +two stages. So sometimes people like to + + align:start position:0% +two stages. So sometimes people like to + + + align:start position:0% +two stages. So sometimes people like to +brainstorm on their own for a bit and + + align:start position:0% +brainstorm on their own for a bit and + + + align:start position:0% +brainstorm on their own for a bit and +then come together and bring those ideas + + align:start position:0% +then come together and bring those ideas + + + align:start position:0% +then come together and bring those ideas +to a brainstorm and also build on more + + align:start position:0% +to a brainstorm and also build on more + + + align:start position:0% +to a brainstorm and also build on more +in a group brainstorm session. Some + + align:start position:0% +in a group brainstorm session. Some + + + align:start position:0% +in a group brainstorm session. Some +people prefer just to do a group + + align:start position:0% +people prefer just to do a group + + + align:start position:0% +people prefer just to do a group +brainstorming session. So it's up to + + align:start position:0% +brainstorming session. So it's up to + + + align:start position:0% +brainstorming session. So it's up to +you. But the second brainstorm should at + + align:start position:0% +you. But the second brainstorm should at + + + align:start position:0% +you. But the second brainstorm should at +least have a group component. Um and for + + align:start position:0% +least have a group component. Um and for + + + align:start position:0% +least have a group component. Um and for +those it's just two animated annotated + + align:start position:0% +those it's just two animated annotated + + + align:start position:0% +those it's just two animated annotated +pictures for each project. And so it's + + align:start position:0% +pictures for each project. And so it's + + + align:start position:0% +pictures for each project. And so it's +fewer pictures because it's it's not per + + align:start position:0% +fewer pictures because it's it's not per + + + align:start position:0% +fewer pictures because it's it's not per +team member. And so um you guys can just + + align:start position:0% +team member. And so um you guys can just + + + align:start position:0% +team member. And so um you guys can just +figure out how you want to split those + + align:start position:0% +figure out how you want to split those + + + align:start position:0% +figure out how you want to split those +up. Uh, another thing is the big + + align:start position:0% +up. Uh, another thing is the big + + + align:start position:0% +up. Uh, another thing is the big +questions you have that you want to make + + align:start position:0% +questions you have that you want to make + + + align:start position:0% +questions you have that you want to make +sure you get answered that you have + + align:start position:0% +sure you get answered that you have + + + align:start position:0% +sure you get answered that you have +those in mind so that you make sure by + + align:start position:0% +those in mind so that you make sure by + + + align:start position:0% +those in mind so that you make sure by +the end of the trip you've gotten + + align:start position:0% +the end of the trip you've gotten + + + align:start position:0% +the end of the trip you've gotten +answers to those questions. Um, and all + + align:start position:0% +answers to those questions. Um, and all + + + align:start position:0% +answers to those questions. Um, and all +of these questions are related to + + align:start position:0% +of these questions are related to + + + align:start position:0% +of these questions are related to +figuring out can you actually work on + + align:start position:0% +figuring out can you actually work on + + + align:start position:0% +figuring out can you actually work on +this project? Is this a good project? + + align:start position:0% +this project? Is this a good project? + + + align:start position:0% +this project? Is this a good project? +And if you are going to work on it, what + + align:start position:0% +And if you are going to work on it, what + + + align:start position:0% +And if you are going to work on it, what +what is the appropriate deliverable? + + align:start position:0% +what is the appropriate deliverable? + + + align:start position:0% +what is the appropriate deliverable? +That's the type of questions. Um, a + + align:start position:0% +That's the type of questions. Um, a + + + align:start position:0% +That's the type of questions. Um, a +materials list for the trip. So, you may + + align:start position:0% +materials list for the trip. So, you may + + + align:start position:0% +materials list for the trip. So, you may +well need some materials if you're going + + align:start position:0% +well need some materials if you're going + + + align:start position:0% +well need some materials if you're going +to do a charcoal demonstration. If + + align:start position:0% +to do a charcoal demonstration. If + + + align:start position:0% +to do a charcoal demonstration. If +you're going to try to build a washing + + align:start position:0% +you're going to try to build a washing + + + align:start position:0% +you're going to try to build a washing +machine, if you have a great idea for um + + align:start position:0% +machine, if you have a great idea for um + + + align:start position:0% +machine, if you have a great idea for um +a project and you want to try to + + align:start position:0% +a project and you want to try to + + + align:start position:0% +a project and you want to try to +actually implement either a prototype or + + align:start position:0% +actually implement either a prototype or + + + align:start position:0% +actually implement either a prototype or +something in the field, your community + + align:start position:0% +something in the field, your community + + + align:start position:0% +something in the field, your community +partner needs to know so that they can + + align:start position:0% +partner needs to know so that they can + + + align:start position:0% +partner needs to know so that they can +provide the materials andor we need to + + align:start position:0% +provide the materials andor we need to + + + align:start position:0% +provide the materials andor we need to +get them here so that we can bring them + + align:start position:0% +get them here so that we can bring them + + + align:start position:0% +get them here so that we can bring them +down. And so, um + + align:start position:0% +down. And so, um + + + align:start position:0% +down. And so, um +I put that you don't need this until the + + align:start position:0% +I put that you don't need this until the + + + align:start position:0% +I put that you don't need this until the +16th, which is right before the trip. + + align:start position:0% +16th, which is right before the trip. + + + align:start position:0% +16th, which is right before the trip. +And that's only if like that's the last + + align:start position:0% +And that's only if like that's the last + + + align:start position:0% +And that's only if like that's the last +desperate time. If you can define them + + align:start position:0% +desperate time. If you can define them + + + align:start position:0% +desperate time. If you can define them +sooner, that's better so that your + + align:start position:0% +sooner, that's better so that your + + + align:start position:0% +sooner, that's better so that your +community partner has time to get them + + align:start position:0% +community partner has time to get them + + + align:start position:0% +community partner has time to get them +and or we have time to get them if you + + align:start position:0% +and or we have time to get them if you + + + align:start position:0% +and or we have time to get them if you +need help. Um, + + align:start position:0% +need help. Um, + + + align:start position:0% +need help. Um, +oh no, that was questions. Materials is + + align:start position:0% +oh no, that was questions. Materials is + + + align:start position:0% +oh no, that was questions. Materials is +earlier. Okay, good. That makes more + + align:start position:0% +earlier. Okay, good. That makes more + + + align:start position:0% +earlier. Okay, good. That makes more +sense. And then finally on the 16th + + align:start position:0% +sense. And then finally on the 16th + + + align:start position:0% +sense. And then finally on the 16th +you're going to do about a 15inute + + align:start position:0% +you're going to do about a 15inute + + + align:start position:0% +you're going to do about a 15inute +presentation um on your literature + + align:start position:0% +presentation um on your literature + + + align:start position:0% +presentation um on your literature +literature search findings your project + + align:start position:0% +literature search findings your project + + + align:start position:0% +literature search findings your project +specifications the annotated pictures + + align:start position:0% +specifications the annotated pictures + + + align:start position:0% +specifications the annotated pictures +the key questions and your key expected + + align:start position:0% +the key questions and your key expected + + + align:start position:0% +the key questions and your key expected +activities just so that you're well + + align:start position:0% +activities just so that you're well + + + align:start position:0% +activities just so that you're well +prepared for the trip. So that's + + align:start position:0% +prepared for the trip. So that's + + + align:start position:0% +prepared for the trip. So that's +basically the assignments apart from a + + align:start position:0% +basically the assignments apart from a + + + align:start position:0% +basically the assignments apart from a +little bit of reading for the next few + + align:start position:0% +little bit of reading for the next few + + + align:start position:0% +little bit of reading for the next few +weeks um which again violates the + + align:start position:0% +weeks um which again violates the + + + align:start position:0% +weeks um which again violates the +syllabus but um hopefully will work out. + + align:start position:0% +syllabus but um hopefully will work out. + + + align:start position:0% +syllabus but um hopefully will work out. +So, um, or be okay with you guys. Um, + + align:start position:0% +So, um, or be okay with you guys. Um, + + + align:start position:0% +So, um, or be okay with you guys. Um, +but I didn't want to add problem sets on + + align:start position:0% +but I didn't want to add problem sets on + + + align:start position:0% +but I didn't want to add problem sets on +top of this because this is a lot of + + align:start position:0% +top of this because this is a lot of + + + align:start position:0% +top of this because this is a lot of +work. Um, are there any questions about + + align:start position:0% +work. Um, are there any questions about + + + align:start position:0% +work. Um, are there any questions about +all of this? I have it, um, printed out + + align:start position:0% +all of this? I have it, um, printed out + + + align:start position:0% +all of this? I have it, um, printed out +so that when you're working on it today, + + align:start position:0% +so that when you're working on it today, + + + align:start position:0% +so that when you're working on it today, +you have something to refer to. Um, + + align:start position:0% +you have something to refer to. Um, + + + align:start position:0% +you have something to refer to. Um, +yeah. + + align:start position:0% +yeah. + + + align:start position:0% +yeah. +Did you get the dates for the flight? + + align:start position:0% +Did you get the dates for the flight? + + + align:start position:0% +Did you get the dates for the flight? +Yeah. Um, so most people are flying on + + align:start position:0% +Yeah. Um, so most people are flying on + + + align:start position:0% +Yeah. Um, so most people are flying on +Well, are people So people going to + + align:start position:0% +Well, are people So people going to + + + align:start position:0% +Well, are people So people going to +Nicaragua are flying on Sunday and + + align:start position:0% +Nicaragua are flying on Sunday and + + + align:start position:0% +Nicaragua are flying on Sunday and +getting back on the following Sunday. + + align:start position:0% +getting back on the following Sunday. + + + align:start position:0% +getting back on the following Sunday. +Um, what about El Salvador? Unless So, + + align:start position:0% +Um, what about El Salvador? Unless So, + + + align:start position:0% +Um, what about El Salvador? Unless So, +uh, Juan and Jessica have personal + + align:start position:0% +uh, Juan and Jessica have personal + + + align:start position:0% +uh, Juan and Jessica have personal +commitments, so they're flying back on + + align:start position:0% +commitments, so they're flying back on + + + align:start position:0% +commitments, so they're flying back on +Friday. + + align:start position:0% + + + + align:start position:0% + +And do you know what El Salvador is + + align:start position:0% +And do you know what El Salvador is + + + align:start position:0% +And do you know what El Salvador is +doing yet? Am + + align:start position:0% +doing yet? Am + + + align:start position:0% +doing yet? Am +Saturday. + + align:start position:0% +Saturday. + + + align:start position:0% +Saturday. +Okay. So, El Salvador may be traveling a + + align:start position:0% +Okay. So, El Salvador may be traveling a + + + align:start position:0% +Okay. So, El Salvador may be traveling a +day early. + + align:start position:0% +day early. + + + align:start position:0% +day early. +So, + + align:start position:0% +So, + + + align:start position:0% +So, +whatever the days are, + + align:start position:0% +whatever the days are, + + + align:start position:0% +whatever the days are, +I think so. + + align:start position:0% +I think so. + + + align:start position:0% +I think so. +Yeah. The 18th is the Friday. So, the + + align:start position:0% +Yeah. The 18th is the Friday. So, the + + + align:start position:0% +Yeah. The 18th is the Friday. So, the +Sunday would be the 20th. Um, and we'll + + align:start position:0% +Sunday would be the 20th. Um, and we'll + + + align:start position:0% +Sunday would be the 20th. Um, and we'll +send out your actual itinerary soon. + + align:start position:0% +send out your actual itinerary soon. + + + align:start position:0% +send out your actual itinerary soon. +Some of the tickets are booked, others + + align:start position:0% +Some of the tickets are booked, others + + + align:start position:0% +Some of the tickets are booked, others +are just reserved and we'll be booking + + align:start position:0% +are just reserved and we'll be booking + + + align:start position:0% +are just reserved and we'll be booking +them today. Um, so there's a couple of + + align:start position:0% +them today. Um, so there's a couple of + + + align:start position:0% +them today. Um, so there's a couple of +reading assignments um that'll be up on + + align:start position:0% +reading assignments um that'll be up on + + + align:start position:0% +reading assignments um that'll be up on +Stellar shortly. Um, this is just a + + align:start position:0% +Stellar shortly. Um, this is just a + + + align:start position:0% +Stellar shortly. Um, this is just a +somewhat different perspective from the + + align:start position:0% +somewhat different perspective from the + + + align:start position:0% +somewhat different perspective from the +Paul Pak reading you did. Um, and then + + align:start position:0% +Paul Pak reading you did. Um, and then + + + align:start position:0% +Paul Pak reading you did. Um, and then +this is directions on on charcoal + + align:start position:0% +this is directions on on charcoal + + + align:start position:0% +this is directions on on charcoal +making. So, both are are quite short. + + align:start position:0% +making. So, both are are quite short. + + + align:start position:0% +making. So, both are are quite short. +So, I know it might be seeming like a + + align:start position:0% +So, I know it might be seeming like a + + + align:start position:0% +So, I know it might be seeming like a +lot, but these are very manageable um to + + align:start position:0% +lot, but these are very manageable um to + + + align:start position:0% +lot, but these are very manageable um to +get done. + + align:start position:0% +get done. + + + align:start position:0% +get done. +So, um, now I just want to go over how + + align:start position:0% +So, um, now I just want to go over how + + + align:start position:0% +So, um, now I just want to go over how +to do brainstorming and then we can take + + align:start position:0% +to do brainstorming and then we can take + + + align:start position:0% +to do brainstorming and then we can take +a break and then you can get into your + + align:start position:0% +a break and then you can get into your + + + align:start position:0% +a break and then you can get into your +project groups and do brainstorming and + + align:start position:0% +project groups and do brainstorming and + + + align:start position:0% +project groups and do brainstorming and +start talking about the trip. Um, and + + align:start position:0% +start talking about the trip. Um, and + + + align:start position:0% +start talking about the trip. Um, and +then at two uh your mentors will show up + + align:start position:0% +then at two uh your mentors will show up + + + align:start position:0% +then at two uh your mentors will show up +unless your mentor is on meet. He's + + align:start position:0% +unless your mentor is on meet. He's + + + align:start position:0% +unless your mentor is on meet. He's +already here. Um, or trip trip leader um + + align:start position:0% +already here. Um, or trip trip leader um + + + align:start position:0% +already here. Um, or trip trip leader um +and uh so you can get support from them + + align:start position:0% +and uh so you can get support from them + + + align:start position:0% +and uh so you can get support from them +as well and and get to know them. So + + align:start position:0% +as well and and get to know them. So + + + align:start position:0% +as well and and get to know them. So +um effective and fun brainstorming you + + align:start position:0% +um effective and fun brainstorming you + + + align:start position:0% +um effective and fun brainstorming you +require a clear problem statement. So + + align:start position:0% +require a clear problem statement. So + + + align:start position:0% +require a clear problem statement. So +for this case um + + align:start position:0% + + + + align:start position:0% + +you're it's whatever the project idea is + + align:start position:0% +you're it's whatever the project idea is + + + align:start position:0% +you're it's whatever the project idea is +for your community partner project. Um + + align:start position:0% +for your community partner project. Um + + + align:start position:0% +for your community partner project. Um +after the + + align:start position:0% +after the + + + align:start position:0% +after the +after you get back from spring break, + + align:start position:0% +after you get back from spring break, + + + align:start position:0% +after you get back from spring break, +you have about four weeks of building + + align:start position:0% +you have about four weeks of building + + + align:start position:0% +you have about four weeks of building +and you have about a $500 budget. So, + + align:start position:0% +and you have about a $500 budget. So, + + + align:start position:0% +and you have about a $500 budget. So, +while you'll see I'm going to encourage + + align:start position:0% +while you'll see I'm going to encourage + + + align:start position:0% +while you'll see I'm going to encourage +you to have really wild ideas. + + align:start position:0% +you to have really wild ideas. + + + align:start position:0% +you to have really wild ideas. +And so, if you come up with a idea that + + align:start position:0% +And so, if you come up with a idea that + + + align:start position:0% +And so, if you come up with a idea that +completely violates the four weeks of + + align:start position:0% +completely violates the four weeks of + + + align:start position:0% +completely violates the four weeks of +building in the 500 budgets, still throw + + align:start position:0% +building in the 500 budgets, still throw + + + align:start position:0% +building in the 500 budgets, still throw +it out there. It's nice to have in your + + align:start position:0% +it out there. It's nice to have in your + + + align:start position:0% +it out there. It's nice to have in your +mind a general sense of these sorts of + + align:start position:0% +mind a general sense of these sorts of + + + align:start position:0% +mind a general sense of these sorts of +things so that you're not only + + align:start position:0% +things so that you're not only + + + align:start position:0% +things so that you're not only +brainstorming things that are in the + + align:start position:0% +brainstorming things that are in the + + + align:start position:0% +brainstorming things that are in the +like 7 megawatt wind turbine category. + + align:start position:0% +like 7 megawatt wind turbine category. + + + align:start position:0% +like 7 megawatt wind turbine category. +um if you're thinking about wind power. + + align:start position:0% +um if you're thinking about wind power. + + + align:start position:0% +um if you're thinking about wind power. +Um so for fun and effective + + align:start position:0% +Um so for fun and effective + + + align:start position:0% +Um so for fun and effective +brainstorming um you're trying to + + align:start position:0% +brainstorming um you're trying to + + + align:start position:0% +brainstorming um you're trying to +generate as many ideas as you can in 15 + + align:start position:0% +generate as many ideas as you can in 15 + + + align:start position:0% +generate as many ideas as you can in 15 +minutes. Um + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +15 minutes is a good length of time. + + align:start position:0% +15 minutes is a good length of time. + + + align:start position:0% +15 minutes is a good length of time. +Sometimes you need a little more a + + align:start position:0% +Sometimes you need a little more a + + + align:start position:0% +Sometimes you need a little more a +little le less but around that time for + + align:start position:0% +little le less but around that time for + + + align:start position:0% +little le less but around that time for +any particular project statement. and + + align:start position:0% +any particular project statement. and + + + align:start position:0% +any particular project statement. and +then you can say take a break, take a + + align:start position:0% +then you can say take a break, take a + + + align:start position:0% +then you can say take a break, take a +stretch, and then come back and work on + + align:start position:0% +stretch, and then come back and work on + + + align:start position:0% +stretch, and then come back and work on +the next problem statement. Um, you want + + align:start position:0% +the next problem statement. Um, you want + + + align:start position:0% +the next problem statement. Um, you want +your sketch to really be a picture with + + align:start position:0% +your sketch to really be a picture with + + + align:start position:0% +your sketch to really be a picture with +a few words. So, a lot of people, if you + + align:start position:0% +a few words. So, a lot of people, if you + + + align:start position:0% +a few words. So, a lot of people, if you +know they're brainstorming weapons of + + align:start position:0% +know they're brainstorming weapons of + + + align:start position:0% +know they're brainstorming weapons of +war + + align:start position:0% +war + + + align:start position:0% +war +and you have your eight and a half piece + + align:start position:0% +and you have your eight and a half piece + + + align:start position:0% +and you have your eight and a half piece +of paper, might draw + + align:start position:0% +of paper, might draw + + + align:start position:0% +of paper, might draw +this. + + align:start position:0% + + + + align:start position:0% + +And I would say that this picture is a + + align:start position:0% +And I would say that this picture is a + + + align:start position:0% +And I would say that this picture is a +lot more evocative of what your idea is + + align:start position:0% +lot more evocative of what your idea is + + + align:start position:0% +lot more evocative of what your idea is +than using the words big and the, you + + align:start position:0% +than using the words big and the, you + + + align:start position:0% +than using the words big and the, you +know, just a tiny drawing. And those of + + align:start position:0% +know, just a tiny drawing. And those of + + + align:start position:0% +know, just a tiny drawing. And those of +us who are not so good at drawing, and + + align:start position:0% +us who are not so good at drawing, and + + + align:start position:0% +us who are not so good at drawing, and +I'm one of them, are tempted to draw + + align:start position:0% +I'm one of them, are tempted to draw + + + align:start position:0% +I'm one of them, are tempted to draw +really small because you don't want to + + align:start position:0% +really small because you don't want to + + + align:start position:0% +really small because you don't want to +show in really big format just how bad + + align:start position:0% +show in really big format just how bad + + + align:start position:0% +show in really big format just how bad +your drawing is. But even being a weak + + align:start position:0% +your drawing is. But even being a weak + + + align:start position:0% +your drawing is. But even being a weak +drawer, you can still get your idea + + align:start position:0% +drawer, you can still get your idea + + + align:start position:0% +drawer, you can still get your idea +across pretty well. This is like a + + align:start position:0% +across pretty well. This is like a + + + align:start position:0% +across pretty well. This is like a +threeinut sketch for an artist. So none + + align:start position:0% +threeinut sketch for an artist. So none + + + align:start position:0% +threeinut sketch for an artist. So none +of your brainstorm ideas are going to + + align:start position:0% +of your brainstorm ideas are going to + + + align:start position:0% +of your brainstorm ideas are going to +look this crafted. This might be some + + align:start position:0% +look this crafted. This might be some + + + align:start position:0% +look this crafted. This might be some +the actual annotated sketch that you + + align:start position:0% +the actual annotated sketch that you + + + align:start position:0% +the actual annotated sketch that you +turn in that you actually refine and + + align:start position:0% +turn in that you actually refine and + + + align:start position:0% +turn in that you actually refine and +spend some time on. So, you know, the + + align:start position:0% +spend some time on. So, you know, the + + + align:start position:0% +spend some time on. So, you know, the +10-second version is going to be a guy + + align:start position:0% +10-second version is going to be a guy + + + align:start position:0% +10-second version is going to be a guy +and you have a guy and he's shooting + + align:start position:0% +and you have a guy and he's shooting + + + align:start position:0% +and you have a guy and he's shooting +stuff and here's the person who's + + align:start position:0% +stuff and here's the person who's + + + align:start position:0% +stuff and here's the person who's +unhappy getting shot at. And then here's + + align:start position:0% +unhappy getting shot at. And then here's + + + align:start position:0% +unhappy getting shot at. And then here's +the wheel that's moving your wall of + + align:start position:0% +the wheel that's moving your wall of + + + align:start position:0% +the wheel that's moving your wall of +doom. Right? So, this is a really fast + + align:start position:0% +doom. Right? So, this is a really fast + + + align:start position:0% +doom. Right? So, this is a really fast +version of that sketch. And um so that's + + align:start position:0% +version of that sketch. And um so that's + + + align:start position:0% +version of that sketch. And um so that's +what I'm looking for, not that. But I + + align:start position:0% +what I'm looking for, not that. But I + + + align:start position:0% +what I'm looking for, not that. But I +just wanted to emphasize it's most + + align:start position:0% +just wanted to emphasize it's most + + + align:start position:0% +just wanted to emphasize it's most +people start out you doing this and you + + align:start position:0% +people start out you doing this and you + + + align:start position:0% +people start out you doing this and you +really want to force yourself to do that + + align:start position:0% +really want to force yourself to do that + + + align:start position:0% +really want to force yourself to do that +with maybe you know the description at + + align:start position:0% +with maybe you know the description at + + + align:start position:0% +with maybe you know the description at +the top or the bottom but the picture + + align:start position:0% +the top or the bottom but the picture + + + align:start position:0% +the top or the bottom but the picture +should dominate not the words. + + align:start position:0% +should dominate not the words. + + + align:start position:0% +should dominate not the words. +Yeah. + + align:start position:0% +Yeah. + + + align:start position:0% +Yeah. +So I'm still a little confused as to how + + align:start position:0% +So I'm still a little confused as to how + + + align:start position:0% +So I'm still a little confused as to how +like the three projects that you listed + + align:start position:0% +like the three projects that you listed + + + align:start position:0% +like the three projects that you listed +on each slide relate to like the + + align:start position:0% +on each slide relate to like the + + + align:start position:0% +on each slide relate to like the +brainstorming and the + + align:start position:0% +brainstorming and the + + + align:start position:0% +brainstorming and the +Yeah. So the three projects, so if one + + align:start position:0% +Yeah. So the three projects, so if one + + + align:start position:0% +Yeah. So the three projects, so if one +of your projects was the feed shopper, + + align:start position:0% +of your projects was the feed shopper, + + + align:start position:0% +of your projects was the feed shopper, +right? Now you know nothing about that + + align:start position:0% +right? Now you know nothing about that + + + align:start position:0% +right? Now you know nothing about that +project, right? So you may not be able + + align:start position:0% +project, right? So you may not be able + + + align:start position:0% +project, right? So you may not be able +to brainstorm that at all until you come + + align:start position:0% +to brainstorm that at all until you come + + + align:start position:0% +to brainstorm that at all until you come +talk to me, which is part of what you + + align:start position:0% +talk to me, which is part of what you + + + align:start position:0% +talk to me, which is part of what you +need to do in the next hour and a half + + align:start position:0% +need to do in the next hour and a half + + + align:start position:0% +need to do in the next hour and a half +um is come talk to me so I can give each + + align:start position:0% +um is come talk to me so I can give each + + + align:start position:0% +um is come talk to me so I can give each +team a little bit more detail about + + align:start position:0% +team a little bit more detail about + + + align:start position:0% +team a little bit more detail about +their three projects. Um but one of them + + align:start position:0% +their three projects. Um but one of them + + + align:start position:0% +their three projects. Um but one of them +like might be something you you can + + align:start position:0% +like might be something you you can + + + align:start position:0% +like might be something you you can +brainstorm on initially um if there's a + + align:start position:0% +brainstorm on initially um if there's a + + + align:start position:0% +brainstorm on initially um if there's a +cue to wait for me. But either way, once + + align:start position:0% +cue to wait for me. But either way, once + + + align:start position:0% +cue to wait for me. But either way, once +you know a little bit about the feed + + align:start position:0% +you know a little bit about the feed + + + align:start position:0% +you know a little bit about the feed +chopper, then that'll be one of your + + align:start position:0% +chopper, then that'll be one of your + + + align:start position:0% +chopper, then that'll be one of your +brainstorming assignments is the the + + align:start position:0% +brainstorming assignments is the the + + + align:start position:0% +brainstorming assignments is the the +project the the community partner needs + + align:start position:0% +project the the community partner needs + + + align:start position:0% +project the the community partner needs +this this um mechanization of the feed + + align:start position:0% +this this um mechanization of the feed + + + align:start position:0% +this this um mechanization of the feed +chopper and let's brainstorm ways to + + align:start position:0% +chopper and let's brainstorm ways to + + + align:start position:0% +chopper and let's brainstorm ways to +mechanize that feed chopper. Um and just + + align:start position:0% +mechanize that feed chopper. Um and just + + + align:start position:0% +mechanize that feed chopper. Um and just +put out as many ideas as you can in 15 + + align:start position:0% +put out as many ideas as you can in 15 + + + align:start position:0% +put out as many ideas as you can in 15 +minutes. Um, and a good goal is to be + + align:start position:0% +minutes. Um, and a good goal is to be + + + align:start position:0% +minutes. Um, and a good goal is to be +generating like at least three ideas per + + align:start position:0% +generating like at least three ideas per + + + align:start position:0% +generating like at least three ideas per +minute, which doesn't sound like that + + align:start position:0% +minute, which doesn't sound like that + + + align:start position:0% +minute, which doesn't sound like that +many, but it's pretty challenging. Um, + + align:start position:0% +many, but it's pretty challenging. Um, + + + align:start position:0% +many, but it's pretty challenging. Um, +but that is sort of something to keep in + + align:start position:0% +but that is sort of something to keep in + + + align:start position:0% +but that is sort of something to keep in +your mind is I should be generating + + align:start position:0% +your mind is I should be generating + + + align:start position:0% +your mind is I should be generating +three ideas per minute. And so, if I'm + + align:start position:0% +three ideas per minute. And so, if I'm + + + align:start position:0% +three ideas per minute. And so, if I'm +not, I need to get crazier probably um, + + align:start position:0% +not, I need to get crazier probably um, + + + align:start position:0% +not, I need to get crazier probably um, +and less inhibited in order to + + align:start position:0% +and less inhibited in order to + + + align:start position:0% +and less inhibited in order to +successfully do it. Um, and so when once + + align:start position:0% +successfully do it. Um, and so when once + + + align:start position:0% +successfully do it. Um, and so when once +you draw this beautiful picture with + + align:start position:0% +you draw this beautiful picture with + + + align:start position:0% +you draw this beautiful picture with +your group, what you do is everyone's + + align:start position:0% +your group, what you do is everyone's + + + align:start position:0% +your group, what you do is everyone's +hopefully drawing and you just say, "Hey + + align:start position:0% +hopefully drawing and you just say, "Hey + + + align:start position:0% +hopefully drawing and you just say, "Hey +guys, my idea is an advancing wall of + + align:start position:0% +guys, my idea is an advancing wall of + + + align:start position:0% +guys, my idea is an advancing wall of +doom." Um, and then you grab a piece of + + align:start position:0% +doom." Um, and then you grab a piece of + + + align:start position:0% +doom." Um, and then you grab a piece of +tape and we're going to use the um the + + align:start position:0% +tape and we're going to use the um the + + + align:start position:0% +tape and we're going to use the um the +three fume hoods as our our boards. So + + align:start position:0% +three fume hoods as our our boards. So + + + align:start position:0% +three fume hoods as our our boards. So +each group will be around a fume hood. + + align:start position:0% +each group will be around a fume hood. + + + align:start position:0% +each group will be around a fume hood. +And so just tape your idea up on the + + align:start position:0% +And so just tape your idea up on the + + + align:start position:0% +And so just tape your idea up on the +wall and then get back on drawing. And + + align:start position:0% +wall and then get back on drawing. And + + + align:start position:0% +wall and then get back on drawing. And +if Kurt, you had said this advancing + + align:start position:0% +if Kurt, you had said this advancing + + + align:start position:0% +if Kurt, you had said this advancing +wall of doom, and I love that idea, I + + align:start position:0% +wall of doom, and I love that idea, I + + + align:start position:0% +wall of doom, and I love that idea, I +can say, yeah, it's going to be an + + align:start position:0% +can say, yeah, it's going to be an + + + align:start position:0% +can say, yeah, it's going to be an +advancing wall of doom, but instead of + + align:start position:0% +advancing wall of doom, but instead of + + + align:start position:0% +advancing wall of doom, but instead of +being wheelpowered, it's going to be um + + align:start position:0% +being wheelpowered, it's going to be um + + + align:start position:0% +being wheelpowered, it's going to be um +on on a big wheelpowered, it's going to + + align:start position:0% +on on a big wheelpowered, it's going to + + + align:start position:0% +on on a big wheelpowered, it's going to +be on a bunch of little wheels. And so + + align:start position:0% +be on a bunch of little wheels. And so + + + align:start position:0% +be on a bunch of little wheels. And so +in other circles, that might be + + align:start position:0% +in other circles, that might be + + + align:start position:0% +in other circles, that might be +considered theft, right? And you'd be + + align:start position:0% +considered theft, right? And you'd be + + + align:start position:0% +considered theft, right? And you'd be +really mad at me for stealing your idea. + + align:start position:0% +really mad at me for stealing your idea. + + + align:start position:0% +really mad at me for stealing your idea. +But in brainstorming, that's really + + align:start position:0% +But in brainstorming, that's really + + + align:start position:0% +But in brainstorming, that's really +encouraged is to quote steal people's + + align:start position:0% +encouraged is to quote steal people's + + + align:start position:0% +encouraged is to quote steal people's +ideas. So have no worry about that. Um + + align:start position:0% +ideas. So have no worry about that. Um + + + align:start position:0% +ideas. So have no worry about that. Um +you guys can work out your patent rights + + align:start position:0% +you guys can work out your patent rights + + + align:start position:0% +you guys can work out your patent rights +if you become millionaires over over + + align:start position:0% +if you become millionaires over over + + + align:start position:0% +if you become millionaires over over +your advancing wall of doom um later. + + align:start position:0% +your advancing wall of doom um later. + + + align:start position:0% +your advancing wall of doom um later. +Um so what are the rules of the game? So + + align:start position:0% +Um so what are the rules of the game? So + + + align:start position:0% +Um so what are the rules of the game? So +one is deferred judgment. So + + align:start position:0% +one is deferred judgment. So + + + align:start position:0% +one is deferred judgment. So +when I propose that I want to make a + + align:start position:0% +when I propose that I want to make a + + + align:start position:0% +when I propose that I want to make a +wind turbine that's just going to float + + align:start position:0% +wind turbine that's just going to float + + + align:start position:0% +wind turbine that's just going to float +in the air magically with helium + + align:start position:0% +in the air magically with helium + + + align:start position:0% +in the air magically with helium +balloons and you see a few flaws in that + + align:start position:0% +balloons and you see a few flaws in that + + + align:start position:0% +balloons and you see a few flaws in that +idea. um you just have to bite your + + align:start position:0% +idea. um you just have to bite your + + + align:start position:0% +idea. um you just have to bite your +tongue, right? Um and the one way you + + align:start position:0% +tongue, right? Um and the one way you + + + align:start position:0% +tongue, right? Um and the one way you +can manage that is by saying, "Okay, I'm + + align:start position:0% +can manage that is by saying, "Okay, I'm + + + align:start position:0% +can manage that is by saying, "Okay, I'm +gonna still take your, you know, I'm + + align:start position:0% +gonna still take your, you know, I'm + + + align:start position:0% +gonna still take your, you know, I'm +gonna build on your idea and instead of + + align:start position:0% +gonna build on your idea and instead of + + + align:start position:0% +gonna build on your idea and instead of +helium balloons, we're going to use a + + align:start position:0% +helium balloons, we're going to use a + + + align:start position:0% +helium balloons, we're going to use a +post that's attached to the ground." Um + + align:start position:0% +post that's attached to the ground." Um + + + align:start position:0% +post that's attached to the ground." Um +so, um but defer judgment even of your + + align:start position:0% +so, um but defer judgment even of your + + + align:start position:0% +so, um but defer judgment even of your +own ideas and of anyone else's. You + + align:start position:0% +own ideas and of anyone else's. You + + + align:start position:0% +own ideas and of anyone else's. You +know, if you're showing your idea, no + + align:start position:0% +know, if you're showing your idea, no + + + align:start position:0% +know, if you're showing your idea, no +saying this is really stupid, but here + + align:start position:0% +saying this is really stupid, but here + + + align:start position:0% +saying this is really stupid, but here +it is. Just say what it is. Um hopefully + + align:start position:0% +it is. Just say what it is. Um hopefully + + + align:start position:0% +it is. Just say what it is. Um hopefully +everyone is coming up with some really + + align:start position:0% +everyone is coming up with some really + + + align:start position:0% +everyone is coming up with some really +terrible ideas as well as really really + + align:start position:0% +terrible ideas as well as really really + + + align:start position:0% +terrible ideas as well as really really +good ones. And some of those really + + align:start position:0% +good ones. And some of those really + + + align:start position:0% +good ones. And some of those really +terrible ones have a kernel of + + align:start position:0% +terrible ones have a kernel of + + + align:start position:0% +terrible ones have a kernel of +awesomeness in them. And so that's why + + align:start position:0% +awesomeness in them. And so that's why + + + align:start position:0% +awesomeness in them. And so that's why +it's worth it to get them out. Um one at + + align:start position:0% +it's worth it to get them out. Um one at + + + align:start position:0% +it's worth it to get them out. Um one at +a time. So if everyone is talking at + + align:start position:0% +a time. So if everyone is talking at + + + align:start position:0% +a time. So if everyone is talking at +once, it's ineffective. So post them up + + align:start position:0% +once, it's ineffective. So post them up + + + align:start position:0% +once, it's ineffective. So post them up +one at a time. And you shouldn't draw + + align:start position:0% +one at a time. And you shouldn't draw + + + align:start position:0% +one at a time. And you shouldn't draw +like three ideas on three pieces of on + + align:start position:0% +like three ideas on three pieces of on + + + align:start position:0% +like three ideas on three pieces of on +one piece of paper. You should have each + + align:start position:0% +one piece of paper. You should have each + + + align:start position:0% +one piece of paper. You should have each +piece of paper for each idea. Um as I + + align:start position:0% +piece of paper for each idea. Um as I + + + align:start position:0% +piece of paper for each idea. Um as I +mentioned, so building on ideas. So + + align:start position:0% +mentioned, so building on ideas. So + + + align:start position:0% +mentioned, so building on ideas. So +theft is encouraged. Um don't be afraid + + align:start position:0% +theft is encouraged. Um don't be afraid + + + align:start position:0% +theft is encouraged. Um don't be afraid +of that. Try to stay focused, which can + + align:start position:0% +of that. Try to stay focused, which can + + + align:start position:0% +of that. Try to stay focused, which can +be hard. Spending 15 minutes trying to + + align:start position:0% +be hard. Spending 15 minutes trying to + + + align:start position:0% +be hard. Spending 15 minutes trying to +generate three ideas per minute. That's + + align:start position:0% +generate three ideas per minute. That's + + + align:start position:0% +generate three ideas per minute. That's +a lot of ideas. Um, but do try to do + + align:start position:0% +a lot of ideas. Um, but do try to do + + + align:start position:0% +a lot of ideas. Um, but do try to do +that. And then, um, as I mentioned, be + + align:start position:0% +that. And then, um, as I mentioned, be + + + align:start position:0% +that. And then, um, as I mentioned, be +visual. + + align:start position:0% +visual. + + + align:start position:0% +visual. +Um, and encourage, use wild ideas. Don't + + align:start position:0% +Um, and encourage, use wild ideas. Don't + + + align:start position:0% +Um, and encourage, use wild ideas. Don't +be afraid to be like, uh, yeah, wall of + + align:start position:0% +be afraid to be like, uh, yeah, wall of + + + align:start position:0% +be afraid to be like, uh, yeah, wall of +doom, but it's going to be made out of + + align:start position:0% +doom, but it's going to be made out of + + + align:start position:0% +doom, but it's going to be made out of +peanut butter. Like something that + + align:start position:0% +peanut butter. Like something that + + + align:start position:0% +peanut butter. Like something that +ridiculous, um, you know, just pops in + + align:start position:0% +ridiculous, um, you know, just pops in + + + align:start position:0% +ridiculous, um, you know, just pops in +your head, throw it out there because it + + align:start position:0% +your head, throw it out there because it + + + align:start position:0% +your head, throw it out there because it +may inspire someone to say, well, not + + align:start position:0% +may inspire someone to say, well, not + + + align:start position:0% +may inspire someone to say, well, not +peanut butter, but what about peanut + + align:start position:0% +peanut butter, but what about peanut + + + align:start position:0% +peanut butter, but what about peanut +shells? That would be a really lowcost + + align:start position:0% +shells? That would be a really lowcost + + + align:start position:0% +shells? That would be a really lowcost +way to make it, right? And all of a + + align:start position:0% +way to make it, right? And all of a + + + align:start position:0% +way to make it, right? And all of a +sudden that's a slightly useful idea for + + align:start position:0% +sudden that's a slightly useful idea for + + + align:start position:0% +sudden that's a slightly useful idea for +this ridiculous wall of doom. Um yeah, + + align:start position:0% +this ridiculous wall of doom. Um yeah, + + + align:start position:0% +this ridiculous wall of doom. Um yeah, +and then once you're done, um you can + + align:start position:0% +and then once you're done, um you can + + + align:start position:0% +and then once you're done, um you can +sort the pile + + align:start position:0% +sort the pile + + + align:start position:0% +sort the pile +to + + align:start position:0% +to + + + align:start position:0% +to +um divide + + align:start position:0% +um divide + + + align:start position:0% +um divide +to to get them into themes. So you can + + align:start position:0% +to to get them into themes. So you can + + + align:start position:0% +to to get them into themes. So you can +sort of, you know, just figure out what + + align:start position:0% +sort of, you know, just figure out what + + + align:start position:0% +sort of, you know, just figure out what +are your themes or what are your + + align:start position:0% +are your themes or what are your + + + align:start position:0% +are your themes or what are your +combinations. + + align:start position:0% +combinations. + + + align:start position:0% +combinations. +um figure out do those themes actually + + align:start position:0% +um figure out do those themes actually + + + align:start position:0% +um figure out do those themes actually +make sense and then often refine and + + align:start position:0% +make sense and then often refine and + + + align:start position:0% +make sense and then often refine and +combine the best. So those two ideas + + align:start position:0% +combine the best. So those two ideas + + + align:start position:0% +combine the best. So those two ideas +from each group don't necessarily have + + align:start position:0% +from each group don't necessarily have + + + align:start position:0% +from each group don't necessarily have +to be the ones you came up with but um + + align:start position:0% +to be the ones you came up with but um + + + align:start position:0% +to be the ones you came up with but um +ones that you think are some of the best + + align:start position:0% +ones that you think are some of the best + + + align:start position:0% +ones that you think are some of the best +of the what you came up with. Do you + + align:start position:0% +of the what you came up with. Do you + + + align:start position:0% +of the what you came up with. Do you +guys have questions on that? I went over + + align:start position:0% +guys have questions on that? I went over + + + align:start position:0% +guys have questions on that? I went over +that kind of fast. So + + align:start position:0% +that kind of fast. So + + + align:start position:0% +that kind of fast. So +but yeah. Okay. So then um for the next + + align:start position:0% +but yeah. Okay. So then um for the next + + + align:start position:0% +but yeah. Okay. So then um for the next +hour and a half, you guys can like take + + align:start position:0% +hour and a half, you guys can like take + + + align:start position:0% +hour and a half, you guys can like take +your 10-minute break and then come back + + align:start position:0% +your 10-minute break and then come back + + + align:start position:0% +your 10-minute break and then come back +and do the brainstorming, meet with me. + + align:start position:0% +and do the brainstorming, meet with me. + + + align:start position:0% +and do the brainstorming, meet with me. +Um and then please remember to fill out + + align:start position:0% +Um and then please remember to fill out + + + align:start position:0% +Um and then please remember to fill out +your muddy cards and include the hours + + align:start position:0% +your muddy cards and include the hours + + + align:start position:0% +your muddy cards and include the hours +per week um on them so that uh that you + + align:start position:0% +per week um on them so that uh that you + + + align:start position:0% +per week um on them so that uh that you +think you're spending on the class so + + align:start position:0% +think you're spending on the class so + + + align:start position:0% +think you're spending on the class so +that I I just have a sense of how that's + + align:start position:0% +that I I just have a sense of how that's + + + align:start position:0% +that I I just have a sense of how that's +going. + + align:start position:0% + + + + align:start position:0% + +But it's sort of a big blue box with a + + align:start position:0% +But it's sort of a big blue box with a + + + align:start position:0% +But it's sort of a big blue box with a +lid that you can open and it has like a + + align:start position:0% +lid that you can open and it has like a + + + align:start position:0% +lid that you can open and it has like a +table built in that sits on. + + align:start position:0% +table built in that sits on. + + + align:start position:0% +table built in that sits on. +Wait, so how big is a bunch of + + align:start position:0% +Wait, so how big is a bunch of + + + align:start position:0% +Wait, so how big is a bunch of +um They make them in different size, but + + align:start position:0% +um They make them in different size, but + + + align:start position:0% +um They make them in different size, but +it's basically like this. + + align:start position:0% +it's basically like this. + + + align:start position:0% +it's basically like this. +No, I'm doing a better drawing. + + align:start position:0% + + + + align:start position:0% + +Go. + + align:start position:0% +Go. + + + align:start position:0% +Go. +Wait, it doesn't make sense. It's + + align:start position:0% +Wait, it doesn't make sense. It's + + + align:start position:0% +Wait, it doesn't make sense. It's +supposed to be parabola and it's + + align:start position:0% +supposed to be parabola and it's + + + align:start position:0% +supposed to be parabola and it's +supposed to make + + align:start position:0% +supposed to make + + + align:start position:0% +supposed to make +it look like a funnel. + + align:start position:0% +it look like a funnel. + + + align:start position:0% +it look like a funnel. +I like it. + + align:start position:0% + + + + align:start position:0% + +Steal your idea. I'm trying to make a + + align:start position:0% +Steal your idea. I'm trying to make a + + + align:start position:0% +Steal your idea. I'm trying to make a +parabola. + + align:start position:0% +parabola. + + + align:start position:0% +parabola. +Well, then make it. + + align:start position:0% +Well, then make it. + + + align:start position:0% +Well, then make it. +Wait, hold on. Let me explain what it + + align:start position:0% +Wait, hold on. Let me explain what it + + + align:start position:0% +Wait, hold on. Let me explain what it +is, though. + + align:start position:0% +is, though. + + + align:start position:0% +is, though. +Oh, yeah. + + align:start position:0% +Oh, yeah. + + + align:start position:0% +Oh, yeah. +Oh, I'm trying to make a parabola. So, + + align:start position:0% +Oh, I'm trying to make a parabola. So, + + + align:start position:0% +Oh, I'm trying to make a parabola. So, +it's a parabolic solar cooker. + + align:start position:0% +it's a parabolic solar cooker. + + + align:start position:0% +it's a parabolic solar cooker. +I had thought of parabola. Let me just + + align:start position:0% +I had thought of parabola. Let me just + + + align:start position:0% +I had thought of parabola. Let me just +say + + align:start position:0% +say + + + align:start position:0% +say +that's why that's why you scratch it out + + align:start position:0% +that's why that's why you scratch it out + + + align:start position:0% +that's why that's why you scratch it out +so I could throw out a parabola with + + align:start position:0% +so I could throw out a parabola with + + + align:start position:0% +so I could throw out a parabola with +basically kind of stealing the idea from + + align:start position:0% +basically kind of stealing the idea from + + + align:start position:0% +basically kind of stealing the idea from +I don't know you guys source. They do + + align:start position:0% +I don't know you guys source. They do + + + align:start position:0% +I don't know you guys source. They do +solar cookers and they're in the + + align:start position:0% +solar cookers and they're in the + + + align:start position:0% +solar cookers and they're in the +Himalayas and they're really they use + + align:start position:0% +Himalayas and they're really they use + + + align:start position:0% +Himalayas and they're really they use +they're really mobile. You can fold them + + align:start position:0% +they're really mobile. You can fold them + + + align:start position:0% +they're really mobile. You can fold them +up and carry them around. So that was + + align:start position:0% +up and carry them around. So that was + + + align:start position:0% +up and carry them around. So that was +the idea. + + align:start position:0% +the idea. + + + align:start position:0% +the idea. +That's a redrawing. + + align:start position:0% +That's a redrawing. + + + align:start position:0% +That's a redrawing. +No, I'm trying to drop. + + align:start position:0% +No, I'm trying to drop. + + + align:start position:0% +No, I'm trying to drop. +You're like fine. Whatever. + + align:start position:0% +You're like fine. Whatever. + + + align:start position:0% +You're like fine. Whatever. +You can like redraw the poster over if + + align:start position:0% +You can like redraw the poster over if + + + align:start position:0% +You can like redraw the poster over if +you really want. + + align:start position:0% +you really want. + + + align:start position:0% +you really want. +Um my plan is to email us + + align:start position:0% +Um my plan is to email us + + + align:start position:0% +Um my plan is to email us +combination box and + + align:start position:0% +combination box and + + + align:start position:0% +combination box and +parabolic solar thing heating some kind + + align:start position:0% +parabolic solar thing heating some kind + + + align:start position:0% +parabolic solar thing heating some kind +of heating element then is + + align:start position:0% +of heating element then is + + + align:start position:0% +of heating element then is +So would that be like a liquid? Yeah, + + align:start position:0% +So would that be like a liquid? Yeah, + + + align:start position:0% +So would that be like a liquid? Yeah, +that's a liquid and Oh. Oh, shoot. + + align:start position:0% +that's a liquid and Oh. Oh, shoot. + + + align:start position:0% +that's a liquid and Oh. Oh, shoot. +Shoot. So, it'll have to cycle back. \ No newline at end of file diff --git a/yBgKkYcoPgM.txt b/yBgKkYcoPgM.txt new file mode 100644 index 0000000000000000000000000000000000000000..7a1a524cb3b649ca058824d3d56edc739e87658c --- /dev/null +++ b/yBgKkYcoPgM.txt @@ -0,0 +1,627 @@ +align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +Let's boil the 3,000year history of work + + align:start position:0% +Let's boil the 3,000year history of work + + + align:start position:0% +Let's boil the 3,000year history of work +down to 3 minutes. First, there were + + align:start position:0% +down to 3 minutes. First, there were + + + align:start position:0% +down to 3 minutes. First, there were +hunters and gatherers. Everyone + + align:start position:0% +hunters and gatherers. Everyone + + + align:start position:0% +hunters and gatherers. Everyone +contributed, and their business was + + align:start position:0% +contributed, and their business was + + + align:start position:0% +contributed, and their business was +basically to survive. Eventually, people + + align:start position:0% +basically to survive. Eventually, people + + + align:start position:0% +basically to survive. Eventually, people +began to tame plants and animals, + + align:start position:0% +began to tame plants and animals, + + + align:start position:0% +began to tame plants and animals, +allowing for larger and larger + + align:start position:0% +allowing for larger and larger + + + align:start position:0% +allowing for larger and larger +settlements. This opened up new kinds of + + align:start position:0% +settlements. This opened up new kinds of + + + align:start position:0% +settlements. This opened up new kinds of +work, and if you were lucky, leisure. In + + align:start position:0% +work, and if you were lucky, leisure. In + + + align:start position:0% +work, and if you were lucky, leisure. In +these agricultural civilizations, + + align:start position:0% +these agricultural civilizations, + + + align:start position:0% +these agricultural civilizations, +powerful ruling classes emerged for the + + align:start position:0% +powerful ruling classes emerged for the + + + align:start position:0% +powerful ruling classes emerged for the +first time. In some cultures, hard work + + align:start position:0% +first time. In some cultures, hard work + + + align:start position:0% +first time. In some cultures, hard work +was seen as undignified, so it was + + align:start position:0% +was seen as undignified, so it was + + + align:start position:0% +was seen as undignified, so it was +outsourced to slaves, servants, and + + align:start position:0% +outsourced to slaves, servants, and + + + align:start position:0% +outsourced to slaves, servants, and +serfs, even though hard work made those + + align:start position:0% +serfs, even though hard work made those + + + align:start position:0% +serfs, even though hard work made those +rich lifestyles possible. + + align:start position:0% +rich lifestyles possible. + + + align:start position:0% +rich lifestyles possible. +In other places, hard work was seen as a + + align:start position:0% +In other places, hard work was seen as a + + + align:start position:0% +In other places, hard work was seen as a +virtue, one that signified a person's + + align:start position:0% +virtue, one that signified a person's + + + align:start position:0% +virtue, one that signified a person's +contribution to society, promoted group + + align:start position:0% +contribution to society, promoted group + + + align:start position:0% +contribution to society, promoted group +harmony, or pleased the gods. For some, + + align:start position:0% +harmony, or pleased the gods. For some, + + + align:start position:0% +harmony, or pleased the gods. For some, +working hard became synonymous with + + align:start position:0% +working hard became synonymous with + + + align:start position:0% +working hard became synonymous with +doing good and repenting for one's sins. + + align:start position:0% +doing good and repenting for one's sins. + + + align:start position:0% +doing good and repenting for one's sins. +Where land was cheap and plentiful, + + align:start position:0% +Where land was cheap and plentiful, + + + align:start position:0% +Where land was cheap and plentiful, +families could establish their own + + align:start position:0% +families could establish their own + + + align:start position:0% +families could establish their own +farms. Working the land took on a sense + + align:start position:0% +farms. Working the land took on a sense + + + align:start position:0% +farms. Working the land took on a sense +of community. All family members pitched + + align:start position:0% +of community. All family members pitched + + + align:start position:0% +of community. All family members pitched +in, depended on each other, and their + + align:start position:0% +in, depended on each other, and their + + + align:start position:0% +in, depended on each other, and their +work was never done. + + align:start position:0% +work was never done. + + + align:start position:0% +work was never done. +In many parts of the world, agricultural + + align:start position:0% +In many parts of the world, agricultural + + + align:start position:0% +In many parts of the world, agricultural +improvements enabled surplus crops to + + align:start position:0% +improvements enabled surplus crops to + + + align:start position:0% +improvements enabled surplus crops to +feed more and more artisans living in + + align:start position:0% +feed more and more artisans living in + + + align:start position:0% +feed more and more artisans living in +cities and towns. And so came the craft + + align:start position:0% +cities and towns. And so came the craft + + + align:start position:0% +cities and towns. And so came the craft +stage of work like shoemakers and + + align:start position:0% +stage of work like shoemakers and + + + align:start position:0% +stage of work like shoemakers and +carpenters all very skilled and + + align:start position:0% +carpenters all very skilled and + + + align:start position:0% +carpenters all very skilled and +specialized. + + align:start position:0% +specialized. + + + align:start position:0% +specialized. +Then industrial and capitalist + + align:start position:0% +Then industrial and capitalist + + + align:start position:0% +Then industrial and capitalist +revolutions changed everything and + + align:start position:0% +revolutions changed everything and + + + align:start position:0% +revolutions changed everything and +brought with them mass production. New + + align:start position:0% +brought with them mass production. New + + + align:start position:0% +brought with them mass production. New +kinds of factories demanded new kinds of + + align:start position:0% +kinds of factories demanded new kinds of + + + align:start position:0% +kinds of factories demanded new kinds of +workers all eager to earn a living + + align:start position:0% +workers all eager to earn a living + + + align:start position:0% +workers all eager to earn a living +however they could in a rapidly changing + + align:start position:0% +however they could in a rapidly changing + + + align:start position:0% +however they could in a rapidly changing +world. + + align:start position:0% +world. + + + align:start position:0% +world. +Some workers banded together and took + + align:start position:0% +Some workers banded together and took + + + align:start position:0% +Some workers banded together and took +historic stands for humane work + + align:start position:0% +historic stands for humane work + + + align:start position:0% +historic stands for humane work +conditions and demanded all kinds of + + align:start position:0% +conditions and demanded all kinds of + + + align:start position:0% +conditions and demanded all kinds of +fundamental rights, including the + + align:start position:0% +fundamental rights, including the + + + align:start position:0% +fundamental rights, including the +40-hour work week. + + align:start position:0% +40-hour work week. + + + align:start position:0% +40-hour work week. +The development of computers, the + + align:start position:0% +The development of computers, the + + + align:start position:0% +The development of computers, the +worldwide web, and widespread education + + align:start position:0% +worldwide web, and widespread education + + + align:start position:0% +worldwide web, and widespread education +ushered us into the knowledge-based + + align:start position:0% +ushered us into the knowledge-based + + + align:start position:0% +ushered us into the knowledge-based +economy. While new opportunities are + + align:start position:0% +economy. While new opportunities are + + + align:start position:0% +economy. While new opportunities are +available for some, globalization and + + align:start position:0% +available for some, globalization and + + + align:start position:0% +available for some, globalization and +other forces are leaving other workers + + align:start position:0% +other forces are leaving other workers + + + align:start position:0% +other forces are leaving other workers +behind, feeling like they can't get + + align:start position:0% +behind, feeling like they can't get + + + align:start position:0% +behind, feeling like they can't get +ahead, no matter how hard they try. + + align:start position:0% +ahead, no matter how hard they try. + + + align:start position:0% +ahead, no matter how hard they try. +As fewer people and fewer hours are + + align:start position:0% +As fewer people and fewer hours are + + + align:start position:0% +As fewer people and fewer hours are +needed to do the work of yesterday, + + align:start position:0% +needed to do the work of yesterday, + + + align:start position:0% +needed to do the work of yesterday, +people are adapting again. So, here we + + align:start position:0% +people are adapting again. So, here we + + + align:start position:0% +people are adapting again. So, here we +are. Is this the end of work's + + align:start position:0% +are. Is this the end of work's + + + align:start position:0% +are. Is this the end of work's +evolution? No. + + align:start position:0% +evolution? No. + + + align:start position:0% +evolution? No. +How you live and work will invent the + + align:start position:0% +How you live and work will invent the + + + align:start position:0% +How you live and work will invent the +future. You will work in order to eat. + + align:start position:0% +future. You will work in order to eat. + + + align:start position:0% +future. You will work in order to eat. +You'll eat by outsourcing food + + align:start position:0% +You'll eat by outsourcing food + + + align:start position:0% +You'll eat by outsourcing food +production to other workers. You'll tap + + align:start position:0% +production to other workers. You'll tap + + + align:start position:0% +production to other workers. You'll tap +into a deep human drive to work on + + align:start position:0% +into a deep human drive to work on + + + align:start position:0% +into a deep human drive to work on +something and to make a genuine + + align:start position:0% +something and to make a genuine + + + align:start position:0% +something and to make a genuine +difference doing it. You'll rely on your + + align:start position:0% +difference doing it. You'll rely on your + + + align:start position:0% +difference doing it. You'll rely on your +networks and connections to help you + + align:start position:0% +networks and connections to help you + + + align:start position:0% +networks and connections to help you +out. and you'll help others, too. Maybe + + align:start position:0% +out. and you'll help others, too. Maybe + + + align:start position:0% +out. and you'll help others, too. Maybe +you'll specialize in something no one + + align:start position:0% +you'll specialize in something no one + + + align:start position:0% +you'll specialize in something no one +has thought of before using technology + + align:start position:0% +has thought of before using technology + + + align:start position:0% +has thought of before using technology +no one's seen before. Maybe you'll make + + align:start position:0% +no one's seen before. Maybe you'll make + + + align:start position:0% +no one's seen before. Maybe you'll make +your voice heard among those who find + + align:start position:0% +your voice heard among those who find + + + align:start position:0% +your voice heard among those who find +themselves excluded from today's + + align:start position:0% +themselves excluded from today's + + + align:start position:0% +themselves excluded from today's +economy. + + align:start position:0% +economy. + + + align:start position:0% +economy. +So, keep on working, creating, and + + align:start position:0% +So, keep on working, creating, and + + + align:start position:0% +So, keep on working, creating, and +inventing the future of work. + + align:start position:0% + + + + align:start position:0% + +[Music] \ No newline at end of file diff --git a/yG4bJnFT5-o.txt b/yG4bJnFT5-o.txt new file mode 100644 index 0000000000000000000000000000000000000000..b22ce2685c0dd4a1ed2addd1503e729e471872c0 --- /dev/null +++ b/yG4bJnFT5-o.txt @@ -0,0 +1,10771 @@ +align:start position:0% + +last time. One of the things we we did + + align:start position:0% +last time. One of the things we we did + + + align:start position:0% +last time. One of the things we we did +were we proved two mean value + + align:start position:0% +were we proved two mean value + + + align:start position:0% +were we proved two mean value +inequalities. + + align:start position:0% + + + + align:start position:0% + +So we proved two mean value inequality + + align:start position:0% +So we proved two mean value inequality + + + align:start position:0% +So we proved two mean value inequality +and let me call those + + align:start position:0% + + + + align:start position:0% + +And the first one was that. So if you + + align:start position:0% +And the first one was that. So if you + + + align:start position:0% +And the first one was that. So if you +had a function f on some interval from a + + align:start position:0% +had a function f on some interval from a + + + align:start position:0% +had a function f on some interval from a +to b into r and this function uh f is + + align:start position:0% +to b into r and this function uh f is + + + align:start position:0% +to b into r and this function uh f is +differentiable. + + align:start position:0% + + + + align:start position:0% + +Then it said that there exist some x0 + + align:start position:0% +Then it said that there exist some x0 + + + align:start position:0% +Then it said that there exist some x0 +with uh x0 between strictly between a + + align:start position:0% +with uh x0 between strictly between a + + + align:start position:0% +with uh x0 between strictly between a +and b. So that the derivative + + align:start position:0% +and b. So that the derivative + + + align:start position:0% +and b. So that the derivative +at x0 is equal to uh the average of the + + align:start position:0% +at x0 is equal to uh the average of the + + + align:start position:0% +at x0 is equal to uh the average of the +function or the average of the function + + align:start position:0% +function or the average of the function + + + align:start position:0% +function or the average of the function +at the end points. So this is the + + align:start position:0% +at the end points. So this is the + + + align:start position:0% +at the end points. So this is the +average on the end points divide. So + + align:start position:0% +average on the end points divide. So + + + align:start position:0% +average on the end points divide. So +it's it's average over the length of the + + align:start position:0% +it's it's average over the length of the + + + align:start position:0% +it's it's average over the length of the +interval. So + + align:start position:0% +interval. So + + + align:start position:0% +interval. So +so this is what the mean value theorem + + align:start position:0% +so this is what the mean value theorem + + + align:start position:0% +so this is what the mean value theorem +said. + + align:start position:0% +said. + + + align:start position:0% +said. +And then there was a second mean value + + align:start position:0% +And then there was a second mean value + + + align:start position:0% +And then there was a second mean value +theorem and that was the cush mean value + + align:start position:0% +theorem and that was the cush mean value + + + align:start position:0% +theorem and that was the cush mean value +theorem. + + align:start position:0% +theorem. + + + align:start position:0% +theorem. +So the cushy bean museum + + align:start position:0% + + + + align:start position:0% + +and that was where you had two functions + + align:start position:0% +and that was where you had two functions + + + align:start position:0% +and that was where you had two functions +f and g + + align:start position:0% +f and g + + + align:start position:0% +f and g +on this interval + + align:start position:0% +on this interval + + + align:start position:0% +on this interval +into r and they are both assumed to be + + align:start position:0% +into r and they are both assumed to be + + + align:start position:0% +into r and they are both assumed to be +differentiable. + + align:start position:0% + + + + align:start position:0% + +And then again it was that there exist + + align:start position:0% +And then again it was that there exist + + + align:start position:0% +And then again it was that there exist +some x0 + + align:start position:0% +some x0 + + + align:start position:0% +some x0 +strictly between + + align:start position:0% +strictly between + + + align:start position:0% +strictly between +uh a and b. + + align:start position:0% + + + + align:start position:0% + +And uh if you take the derivative + + align:start position:0% +And uh if you take the derivative + + + align:start position:0% +And uh if you take the derivative +uh at x0 of f + + align:start position:0% +uh at x0 of f + + + align:start position:0% +uh at x0 of f +times the value + + align:start position:0% +times the value + + + align:start position:0% +times the value +uh the difference in value of G at the + + align:start position:0% +uh the difference in value of G at the + + + align:start position:0% +uh the difference in value of G at the +end points. + + align:start position:0% +end points. + + + align:start position:0% +end points. +Then this is equal to the derivative of + + align:start position:0% +Then this is equal to the derivative of + + + align:start position:0% +Then this is equal to the derivative of +G at X0 + + align:start position:0% +G at X0 + + + align:start position:0% +G at X0 +times the difference in value of F at + + align:start position:0% +times the difference in value of F at + + + align:start position:0% +times the difference in value of F at +the end points. + + align:start position:0% + + + + align:start position:0% + +Right? So that was the Kushim man + + align:start position:0% +Right? So that was the Kushim man + + + align:start position:0% +Right? So that was the Kushim man +theorem. So it was a little bit more + + align:start position:0% +theorem. So it was a little bit more + + + align:start position:0% +theorem. So it was a little bit more +complicated than the actual minium + + align:start position:0% +complicated than the actual minium + + + align:start position:0% +complicated than the actual minium +because you had two functions at the + + align:start position:0% +because you had two functions at the + + + align:start position:0% +because you had two functions at the +same time and the point here was that + + align:start position:0% +same time and the point here was that + + + align:start position:0% +same time and the point here was that +you could arrange this x0 to work for + + align:start position:0% +you could arrange this x0 to work for + + + align:start position:0% +you could arrange this x0 to work for +both points for both functions. + + align:start position:0% +both points for both functions. + + + align:start position:0% +both points for both functions. +Let me just make an observation + + align:start position:0% + + + + align:start position:0% + +that if um so if we're looking at so so + + align:start position:0% +that if um so if we're looking at so so + + + align:start position:0% +that if um so if we're looking at so so +so + + align:start position:0% + + + + align:start position:0% + +right so the cushim seems like a more + + align:start position:0% +right so the cushim seems like a more + + + align:start position:0% +right so the cushim seems like a more +elaborate version of the mean value + + align:start position:0% +elaborate version of the mean value + + + align:start position:0% +elaborate version of the mean value +theorem and it really is because if you + + align:start position:0% +theorem and it really is because if you + + + align:start position:0% +theorem and it really is because if you +if you suppose that g here was the + + align:start position:0% +if you suppose that g here was the + + + align:start position:0% +if you suppose that g here was the +function + + align:start position:0% +function + + + align:start position:0% +function +uh that is equal to x. So g of x is + + align:start position:0% +uh that is equal to x. So g of x is + + + align:start position:0% +uh that is equal to x. So g of x is +equal to x. + + align:start position:0% + + + + align:start position:0% + +I have f here on the integral from a to + + align:start position:0% +I have f here on the integral from a to + + + align:start position:0% +I have f here on the integral from a to +b. + + align:start position:0% +b. + + + align:start position:0% +b. +This is again differentiable. + + align:start position:0% + + + + align:start position:0% + +Well, if the other function was just + + align:start position:0% +Well, if the other function was just + + + align:start position:0% +Well, if the other function was just +this sort of rather trivial function G, + + align:start position:0% +this sort of rather trivial function G, + + + align:start position:0% +this sort of rather trivial function G, +of course, G is also differentiable and + + align:start position:0% +of course, G is also differentiable and + + + align:start position:0% +of course, G is also differentiable and +we even know that the derivative of G at + + align:start position:0% +we even know that the derivative of G at + + + align:start position:0% +we even know that the derivative of G at +all points is one, right? So if you are + + align:start position:0% +all points is one, right? So if you are + + + align:start position:0% +all points is one, right? So if you are +now applying the cushy mean then it say + + align:start position:0% +now applying the cushy mean then it say + + + align:start position:0% +now applying the cushy mean then it say +that by the cushy mean + + align:start position:0% + + + + align:start position:0% + +right? there exist some x0 + + align:start position:0% +right? there exist some x0 + + + align:start position:0% +right? there exist some x0 +with uh x0 strictly between a and b + + align:start position:0% +with uh x0 strictly between a and b + + + align:start position:0% +with uh x0 strictly between a and b +and so that the derivative of f so + + align:start position:0% +and so that the derivative of f so + + + align:start position:0% +and so that the derivative of f so +that's whatever that is that's the + + align:start position:0% +that's whatever that is that's the + + + align:start position:0% +that's whatever that is that's the +derivative of f at x0 + + align:start position:0% +derivative of f at x0 + + + align:start position:0% +derivative of f at x0 +the value of g at these two end points + + align:start position:0% +the value of g at these two end points + + + align:start position:0% +the value of g at these two end points +where g is just a function x so this is + + align:start position:0% +where g is just a function x so this is + + + align:start position:0% +where g is just a function x so this is +just b minus a + + align:start position:0% +just b minus a + + + align:start position:0% +just b minus a +and the derivative of g is one + + align:start position:0% +and the derivative of g is one + + + align:start position:0% +and the derivative of g is one +h and then it's the difference in value + + align:start position:0% +h and then it's the difference in value + + + align:start position:0% +h and then it's the difference in value +of f at the end point + + align:start position:0% +of f at the end point + + + align:start position:0% +of f at the end point +right and so now if you just divide by b + + align:start position:0% +right and so now if you just divide by b + + + align:start position:0% +right and so now if you just divide by b +minus a so this of course imply that + + align:start position:0% +minus a so this of course imply that + + + align:start position:0% +minus a so this of course imply that +frime of x0 is equal to f of b minus f + + align:start position:0% +frime of x0 is equal to f of b minus f + + + align:start position:0% +frime of x0 is equal to f of b minus f +of a divided by b minus a. So in other + + align:start position:0% +of a divided by b minus a. So in other + + + align:start position:0% +of a divided by b minus a. So in other +words and so you see this here gives you + + align:start position:0% +words and so you see this here gives you + + + align:start position:0% +words and so you see this here gives you +uh this here gives you this the more + + align:start position:0% +uh this here gives you this the more + + + align:start position:0% +uh this here gives you this the more +standard mean value inequalities. So in + + align:start position:0% +standard mean value inequalities. So in + + + align:start position:0% +standard mean value inequalities. So in +other words, the cushive mean man + + align:start position:0% +other words, the cushive mean man + + + align:start position:0% +other words, the cushive mean man +theorem is more general than the than + + align:start position:0% +theorem is more general than the than + + + align:start position:0% +theorem is more general than the than +than this mean value inequality, right? + + align:start position:0% +than this mean value inequality, right? + + + align:start position:0% +than this mean value inequality, right? +Because you recover this if you just let + + align:start position:0% +Because you recover this if you just let + + + align:start position:0% +Because you recover this if you just let +one of the two functions be just a + + align:start position:0% +one of the two functions be just a + + + align:start position:0% +one of the two functions be just a +trivial function x, right? + + align:start position:0% + + + + align:start position:0% + +Um + + align:start position:0% + + + + align:start position:0% + +okay, so that was just an observation. + + align:start position:0% +okay, so that was just an observation. + + + align:start position:0% +okay, so that was just an observation. +The second thing I want to talk about uh + + align:start position:0% +The second thing I want to talk about uh + + + align:start position:0% +The second thing I want to talk about uh +is something we didn't get to uh last + + align:start position:0% +is something we didn't get to uh last + + + align:start position:0% +is something we didn't get to uh last +time and this is uh this is this uh + + align:start position:0% +time and this is uh this is this uh + + + align:start position:0% +time and this is uh this is this uh +op uh rule + + align:start position:0% + + + + align:start position:0% + +and I'm just going to state one version + + align:start position:0% +and I'm just going to state one version + + + align:start position:0% +and I'm just going to state one version +of it. There are two versions + + align:start position:0% +of it. There are two versions + + + align:start position:0% +of it. There are two versions +and they're both in the notes but I will + + align:start position:0% +and they're both in the notes but I will + + + align:start position:0% +and they're both in the notes but I will +just state one of them. Uh and so this + + align:start position:0% +just state one of them. Uh and so this + + + align:start position:0% +just state one of them. Uh and so this +is so you have so the situation here is + + align:start position:0% +is so you have so the situation here is + + + align:start position:0% +is so you have so the situation here is +that you have two function uh f and g + + align:start position:0% +that you have two function uh f and g + + + align:start position:0% +that you have two function uh f and g +uh and they are defined on some interval + + align:start position:0% +uh and they are defined on some interval + + + align:start position:0% +uh and they are defined on some interval +say from a to b into r + + align:start position:0% +say from a to b into r + + + align:start position:0% +say from a to b into r +uh uh the interval does not include the + + align:start position:0% +uh uh the interval does not include the + + + align:start position:0% +uh uh the interval does not include the +end point. Okay, so these are + + align:start position:0% +end point. Okay, so these are + + + align:start position:0% +end point. Okay, so these are +differentiable. + + align:start position:0% + + + + align:start position:0% + +Uh and then we assume that uh the limit + + align:start position:0% +Uh and then we assume that uh the limit + + + align:start position:0% +Uh and then we assume that uh the limit +here we assume that g sorry uh of x is + + align:start position:0% +here we assume that g sorry uh of x is + + + align:start position:0% +here we assume that g sorry uh of x is +uh and not only g of x but also g prime + + align:start position:0% +uh and not only g of x but also g prime + + + align:start position:0% +uh and not only g of x but also g prime +of x + + align:start position:0% +of x + + + align:start position:0% +of x +are not equal to zero for all + + align:start position:0% + + + + align:start position:0% + +x. + + align:start position:0% + + + + align:start position:0% + +And then we assume that the limit here + + align:start position:0% +And then we assume that the limit here + + + align:start position:0% +And then we assume that the limit here +of g of x as x goes to a + + align:start position:0% +of g of x as x goes to a + + + align:start position:0% +of g of x as x goes to a +that this here is zero. And the same + + align:start position:0% +that this here is zero. And the same + + + align:start position:0% +that this here is zero. And the same +hold for the function + + align:start position:0% +hold for the function + + + align:start position:0% +hold for the function +uh f. + + align:start position:0% + + + + align:start position:0% + +So let's here + + align:start position:0% +So let's here + + + align:start position:0% +So let's here +and then what you're interested in is + + align:start position:0% +and then what you're interested in is + + + align:start position:0% +and then what you're interested in is +what you're interested in is that you're + + align:start position:0% +what you're interested in is that you're + + + align:start position:0% +what you're interested in is that you're +interested in looking at uh f ofx + + align:start position:0% +interested in looking at uh f ofx + + + align:start position:0% +interested in looking at uh f ofx +divided by g of x. Right? So this here + + align:start position:0% +divided by g of x. Right? So this here + + + align:start position:0% +divided by g of x. Right? So this here +makes sense. g doesn't vanish. So this + + align:start position:0% +makes sense. g doesn't vanish. So this + + + align:start position:0% +makes sense. g doesn't vanish. So this +here makes sense. And you are interested + + align:start position:0% +here makes sense. And you are interested + + + align:start position:0% +here makes sense. And you are interested +in looking at this + + align:start position:0% +in looking at this + + + align:start position:0% +in looking at this +fraction here + + align:start position:0% +fraction here + + + align:start position:0% +fraction here +as x go to a right. If x go to a then + + align:start position:0% +as x go to a right. If x go to a then + + + align:start position:0% +as x go to a right. If x go to a then +the denominator go to zero and the + + align:start position:0% +the denominator go to zero and the + + + align:start position:0% +the denominator go to zero and the +nominator also go to zero right and the + + align:start position:0% +nominator also go to zero right and the + + + align:start position:0% +nominator also go to zero right and the +question is does it has have a limit or + + align:start position:0% +question is does it has have a limit or + + + align:start position:0% +question is does it has have a limit or +not right and so there's one more + + align:start position:0% +not right and so there's one more + + + align:start position:0% +not right and so there's one more +assumption here that you need and that + + align:start position:0% +assumption here that you need and that + + + align:start position:0% +assumption here that you need and that +is that um that if you're looking at the + + align:start position:0% +is that um that if you're looking at the + + + align:start position:0% +is that um that if you're looking at the +Assume also + + align:start position:0% + + + + align:start position:0% + +that uh that's the limit here uh as x go + + align:start position:0% +that uh that's the limit here uh as x go + + + align:start position:0% +that uh that's the limit here uh as x go +to a + + align:start position:0% +to a + + + align:start position:0% +to a +of frime of x / g prime assume that this + + align:start position:0% +of frime of x / g prime assume that this + + + align:start position:0% +of frime of x / g prime assume that this +here exist + + align:start position:0% +here exist + + + align:start position:0% +here exist +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +and is equal to some l. Okay. + + align:start position:0% + + + + align:start position:0% + +And then the claim is that then so the + + align:start position:0% +And then the claim is that then so the + + + align:start position:0% +And then the claim is that then so the +claim here is + + align:start position:0% + + + + align:start position:0% + +that the this fraction here f ofx / g of + + align:start position:0% +that the this fraction here f ofx / g of + + + align:start position:0% +that the this fraction here f ofx / g of +x + + align:start position:0% +x + + + align:start position:0% +x +that this does have a limit as x go to a + + align:start position:0% +that this does have a limit as x go to a + + + align:start position:0% +that this does have a limit as x go to a +and that limit is is actually l. + + align:start position:0% + + + + align:start position:0% + +So this is uh this is one version of of + + align:start position:0% +So this is uh this is one version of of + + + align:start position:0% +So this is uh this is one version of of +of of this rule. Okay. And there's a + + align:start position:0% +of of this rule. Okay. And there's a + + + align:start position:0% +of of this rule. Okay. And there's a +there's another one very similar. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +And so so we want to prove this. So uh + + align:start position:0% +And so so we want to prove this. So uh + + + align:start position:0% +And so so we want to prove this. So uh +we looking at so + + align:start position:0% + + + + align:start position:0% + +so we have we want to uh apply the + + align:start position:0% +so we have we want to uh apply the + + + align:start position:0% +so we have we want to uh apply the +Kushim mean value theorem to to prove + + align:start position:0% +Kushim mean value theorem to to prove + + + align:start position:0% +Kushim mean value theorem to to prove +this theorem and so we're looking at a + + align:start position:0% +this theorem and so we're looking at a + + + align:start position:0% +this theorem and so we're looking at a +interval here. + + align:start position:0% +interval here. + + + align:start position:0% +interval here. +Uh so you're looking at at uh say y. So + + align:start position:0% +Uh so you're looking at at uh say y. So + + + align:start position:0% +Uh so you're looking at at uh say y. So +here you have + + align:start position:0% +here you have + + + align:start position:0% +here you have +a + + align:start position:0% +a + + + align:start position:0% +a +here you have uh x and then here you + + align:start position:0% +here you have uh x and then here you + + + align:start position:0% +here you have uh x and then here you +have y and here you have b right and I'm + + align:start position:0% +have y and here you have b right and I'm + + + align:start position:0% +have y and here you have b right and I'm +now going to apply so we will apply the + + align:start position:0% + + + + align:start position:0% + +so apply + + align:start position:0% +so apply + + + align:start position:0% +so apply +the kushimi value + + align:start position:0% + + + + align:start position:0% + +But we are applying it on on this + + align:start position:0% +But we are applying it on on this + + + align:start position:0% +But we are applying it on on this +interval here + + align:start position:0% +interval here + + + align:start position:0% +interval here +between uh so so y here is less than x + + align:start position:0% +between uh so so y here is less than x + + + align:start position:0% +between uh so so y here is less than x +but it's strictly bigger than a and this + + align:start position:0% +but it's strictly bigger than a and this + + + align:start position:0% +but it's strictly bigger than a and this +is x is strictly less than than x right + + align:start position:0% +is x is strictly less than than x right + + + align:start position:0% +is x is strictly less than than x right +so the function was differentiable on + + align:start position:0% +so the function was differentiable on + + + align:start position:0% +so the function was differentiable on +this open interval. So of course it's + + align:start position:0% +this open interval. So of course it's + + + align:start position:0% +this open interval. So of course it's +differentiable or both functions are + + align:start position:0% +differentiable or both functions are + + + align:start position:0% +differentiable or both functions are +differentiable on this closed interval. + + align:start position:0% +differentiable on this closed interval. + + + align:start position:0% +differentiable on this closed interval. +So we can apply it and so we get that uh + + align:start position:0% +So we can apply it and so we get that uh + + + align:start position:0% +So we can apply it and so we get that uh +fprime at some intermediate point + + align:start position:0% +fprime at some intermediate point + + + align:start position:0% +fprime at some intermediate point +uh x0 + + align:start position:0% + + + + align:start position:0% + +uh times uh g + + align:start position:0% +uh times uh g + + + align:start position:0% +uh times uh g +of uh uh x minus g of y. + + align:start position:0% + + + + align:start position:0% + +This is equal to g prime again x0 here + + align:start position:0% +This is equal to g prime again x0 here + + + align:start position:0% +This is equal to g prime again x0 here +is like is some intermediate point in + + align:start position:0% +is like is some intermediate point in + + + align:start position:0% +is like is some intermediate point in +lie between these two + + align:start position:0% +lie between these two + + + align:start position:0% +lie between these two +uh g prime at x0 + + align:start position:0% +uh g prime at x0 + + + align:start position:0% +uh g prime at x0 +times uh f of x minus g of x g of y + + align:start position:0% +times uh f of x minus g of x g of y + + + align:start position:0% +times uh f of x minus g of x g of y +sorry like that + + align:start position:0% +sorry like that + + + align:start position:0% +sorry like that +right this is just uh applying the cushy + + align:start position:0% +right this is just uh applying the cushy + + + align:start position:0% +right this is just uh applying the cushy +mean value + + align:start position:0% +mean value + + + align:start position:0% +mean value +Okay. + + align:start position:0% + + + + align:start position:0% + +>> Uh what what did you say? Oh, yeah. + + align:start position:0% +>> Uh what what did you say? Oh, yeah. + + + align:start position:0% +>> Uh what what did you say? Oh, yeah. +Yeah. Yeah. Sorry about that. Thanks. + + align:start position:0% +Yeah. Yeah. Sorry about that. Thanks. + + + align:start position:0% +Yeah. Yeah. Sorry about that. Thanks. +Yeah. Thank you. + + align:start position:0% +Yeah. Thank you. + + + align:start position:0% +Yeah. Thank you. +Right. And so now I just divide. Of + + align:start position:0% +Right. And so now I just divide. Of + + + align:start position:0% +Right. And so now I just divide. Of +course, this here is supposed to be uh + + align:start position:0% +course, this here is supposed to be uh + + + align:start position:0% +course, this here is supposed to be uh +non zero. So I can just divide. + + align:start position:0% +non zero. So I can just divide. + + + align:start position:0% +non zero. So I can just divide. +Um so so we have that + + align:start position:0% +Um so so we have that + + + align:start position:0% +Um so so we have that +uh that fprime of x0 + + align:start position:0% +uh that fprime of x0 + + + align:start position:0% +uh that fprime of x0 +divided by uh + + align:start position:0% +divided by uh + + + align:start position:0% +divided by uh +by g prime of x0 + + align:start position:0% +by g prime of x0 + + + align:start position:0% +by g prime of x0 +and then I will I want to divide by this + + align:start position:0% +and then I will I want to divide by this + + + align:start position:0% +and then I will I want to divide by this +but I just need to make sure that this + + align:start position:0% +but I just need to make sure that this + + + align:start position:0% +but I just need to make sure that this +here is + + align:start position:0% +here is + + + align:start position:0% +here is +um is + + align:start position:0% +um is + + + align:start position:0% +um is +um + + align:start position:0% +um + + + align:start position:0% +um +that I can divide by right that it's not + + align:start position:0% +that I can divide by right that it's not + + + align:start position:0% +that I can divide by right that it's not +zero this thing here. So I have this + + align:start position:0% + + + + align:start position:0% + +now think about X is being fixed and do + + align:start position:0% +now think about X is being fixed and do + + + align:start position:0% +now think about X is being fixed and do +this for all Y. Right? If I do this, if + + align:start position:0% +this for all Y. Right? If I do this, if + + + align:start position:0% +this for all Y. Right? If I do this, if +I do this for y where y is very very + + align:start position:0% +I do this for y where y is very very + + + align:start position:0% +I do this for y where y is very very +close to a, this here becomes really + + align:start position:0% +close to a, this here becomes really + + + align:start position:0% +close to a, this here becomes really +really close to zero. Right? This here + + align:start position:0% +really close to zero. Right? This here + + + align:start position:0% +really close to zero. Right? This here +is fixed and it's it's not equal to + + align:start position:0% +is fixed and it's it's not equal to + + + align:start position:0% +is fixed and it's it's not equal to +zero. Right? So this here is very close + + align:start position:0% +zero. Right? So this here is very close + + + align:start position:0% +zero. Right? So this here is very close +to zero. This is not equal to zero. So + + align:start position:0% +to zero. This is not equal to zero. So + + + align:start position:0% +to zero. This is not equal to zero. So +this here if y is really close if x is + + align:start position:0% +this here if y is really close if x is + + + align:start position:0% +this here if y is really close if x is +fixed y is really close to a. This is + + align:start position:0% +fixed y is really close to a. This is + + + align:start position:0% +fixed y is really close to a. This is +definitely not zero. Right? So I can + + align:start position:0% +definitely not zero. Right? So I can + + + align:start position:0% +definitely not zero. Right? So I can +divide by it right. + + align:start position:0% +divide by it right. + + + align:start position:0% +divide by it right. +So for + + align:start position:0% +So for + + + align:start position:0% +So for +for x fixed + + align:start position:0% +for x fixed + + + align:start position:0% +for x fixed +and + + align:start position:0% +and + + + align:start position:0% +and +y sufficiently close + + align:start position:0% + + + + align:start position:0% + +close to zero. + + align:start position:0% + + + + align:start position:0% + +then you have then uh + + align:start position:0% +then you have then uh + + + align:start position:0% +then you have then uh +then g of x minus g of y + + align:start position:0% +then g of x minus g of y + + + align:start position:0% +then g of x minus g of y +is not equal to zero. Right? And so I + + align:start position:0% +is not equal to zero. Right? And so I + + + align:start position:0% +is not equal to zero. Right? And so I +can so I get that uh fprime + + align:start position:0% +can so I get that uh fprime + + + align:start position:0% +can so I get that uh fprime +at this intermediate point divided by g + + align:start position:0% +at this intermediate point divided by g + + + align:start position:0% +at this intermediate point divided by g +prime at the same intermediate point is + + align:start position:0% +prime at the same intermediate point is + + + align:start position:0% +prime at the same intermediate point is +equal to f ofx - f of y / g of x minus g + + align:start position:0% +equal to f ofx - f of y / g of x minus g + + + align:start position:0% +equal to f ofx - f of y / g of x minus g +of y + + align:start position:0% +of y + + + align:start position:0% +of y +and now you see that as y here goes to + + align:start position:0% +and now you see that as y here goes to + + + align:start position:0% +and now you see that as y here goes to +zero right so x is fixed still as y goes + + align:start position:0% +zero right so x is fixed still as y goes + + + align:start position:0% +zero right so x is fixed still as y goes +to sorry not to zero But to a this here + + align:start position:0% +to sorry not to zero But to a this here + + + align:start position:0% +to sorry not to zero But to a this here +goes to zero by assumption. This here + + align:start position:0% +goes to zero by assumption. This here + + + align:start position:0% +goes to zero by assumption. This here +goes to zero. So the whole thing goes to + + align:start position:0% +goes to zero. So the whole thing goes to + + + align:start position:0% +goes to zero. So the whole thing goes to +f ofx + + align:start position:0% +f ofx + + + align:start position:0% +f ofx +divided by g of x. + + align:start position:0% +divided by g of x. + + + align:start position:0% +divided by g of x. +Right? + + align:start position:0% +Right? + + + align:start position:0% +Right? +Now the thing is that if you + + align:start position:0% + + + + align:start position:0% + +so this is for all x fixed + + align:start position:0% + + + + align:start position:0% + +Right. So now if you if you + + align:start position:0% +Right. So now if you if you + + + align:start position:0% +Right. So now if you if you +So now we want to use So now you since + + align:start position:0% + + + + align:start position:0% + +uh fprime + + align:start position:0% +uh fprime + + + align:start position:0% +uh fprime +at at say set divided by g prime at set + + align:start position:0% +at at say set divided by g prime at set + + + align:start position:0% +at at say set divided by g prime at set +since this fraction here as set go to a + + align:start position:0% +since this fraction here as set go to a + + + align:start position:0% +since this fraction here as set go to a +this is assumed to go to l right. So + + align:start position:0% +this is assumed to go to l right. So + + + align:start position:0% +this is assumed to go to l right. So +this means that that uh given + + align:start position:0% +this means that that uh given + + + align:start position:0% +this means that that uh given +given epsilon greater than zero there + + align:start position:0% +given epsilon greater than zero there + + + align:start position:0% +given epsilon greater than zero there +exist a delta + + align:start position:0% +exist a delta + + + align:start position:0% +exist a delta +greater than zero. So that if uh if if + + align:start position:0% +greater than zero. So that if uh if if + + + align:start position:0% +greater than zero. So that if uh if if +um set here is uh is less than a plus + + align:start position:0% +um set here is uh is less than a plus + + + align:start position:0% +um set here is uh is less than a plus +delta + + align:start position:0% +delta + + + align:start position:0% +delta +then this fraction here then f prime of + + align:start position:0% +then this fraction here then f prime of + + + align:start position:0% +then this fraction here then f prime of +set minus g prime + + align:start position:0% +set minus g prime + + + align:start position:0% +set minus g prime +of set is minus l + + align:start position:0% +of set is minus l + + + align:start position:0% +of set is minus l +is less than epsilon. + + align:start position:0% +is less than epsilon. + + + align:start position:0% +is less than epsilon. +Right? + + align:start position:0% +Right? + + + align:start position:0% +Right? +So now coming back here + + align:start position:0% +So now coming back here + + + align:start position:0% +So now coming back here +if you were starting with so this here + + align:start position:0% +if you were starting with so this here + + + align:start position:0% +if you were starting with so this here +again was for all fixed x + + align:start position:0% +again was for all fixed x + + + align:start position:0% +again was for all fixed x +right + + align:start position:0% +right + + + align:start position:0% +right +uh you had this statement right and + + align:start position:0% +uh you had this statement right and + + + align:start position:0% +uh you had this statement right and +again + + align:start position:0% +again + + + align:start position:0% +again +uh x0 was between y and x right so now + + align:start position:0% +uh x0 was between y and x right so now + + + align:start position:0% +uh x0 was between y and x right so now +if you so if + + align:start position:0% +if you so if + + + align:start position:0% +if you so if +if this x here If x is + + align:start position:0% + + + + align:start position:0% + +is delta close to the left end point of + + align:start position:0% +is delta close to the left end point of + + + align:start position:0% +is delta close to the left end point of +the interval, right? + + align:start position:0% +the interval, right? + + + align:start position:0% +the interval, right? +Then you would have that + + align:start position:0% +Then you would have that + + + align:start position:0% +Then you would have that +x0, right? But x0 remember that x0 is + + align:start position:0% +x0, right? But x0 remember that x0 is + + + align:start position:0% +x0, right? But x0 remember that x0 is +lying here, right? So since + + align:start position:0% +lying here, right? So since + + + align:start position:0% +lying here, right? So since +x0 would lie here, this means that also + + align:start position:0% +x0 would lie here, this means that also + + + align:start position:0% +x0 would lie here, this means that also +x0 here is uh white is is is + + align:start position:0% +x0 here is uh white is is is + + + align:start position:0% +x0 here is uh white is is is +uh in this interval here, + + align:start position:0% +uh in this interval here, + + + align:start position:0% +uh in this interval here, +right? + + align:start position:0% +right? + + + align:start position:0% +right? +And so this means that this thing this + + align:start position:0% +And so this means that this thing this + + + align:start position:0% +And so this means that this thing this +number here you get is is L with up to + + align:start position:0% +number here you get is is L with up to + + + align:start position:0% +number here you get is is L with up to +some you know it's it's L up to some + + align:start position:0% +some you know it's it's L up to some + + + align:start position:0% +some you know it's it's L up to some +error of like epsilon right + + align:start position:0% +error of like epsilon right + + + align:start position:0% +error of like epsilon right +so this here is almost equal to L and so + + align:start position:0% +so this here is almost equal to L and so + + + align:start position:0% +so this here is almost equal to L and so +this means that this limit here right is + + align:start position:0% +this means that this limit here right is + + + align:start position:0% +this means that this limit here right is +almost equal to L within a error of + + align:start position:0% +almost equal to L within a error of + + + align:start position:0% +almost equal to L within a error of +epsilon right okay so this proof this + + align:start position:0% +epsilon right okay so this proof this + + + align:start position:0% +epsilon right okay so this proof this +version of the + + align:start position:0% +version of the + + + align:start position:0% +version of the +rule and there's a second version and + + align:start position:0% +rule and there's a second version and + + + align:start position:0% +rule and there's a second version and +that's in the notes but uh I'll skip it + + align:start position:0% +that's in the notes but uh I'll skip it + + + align:start position:0% +that's in the notes but uh I'll skip it +actually for now just because you know + + align:start position:0% +actually for now just because you know + + + align:start position:0% +actually for now just because you know +there was sort of from the last lecture + + align:start position:0% +there was sort of from the last lecture + + + align:start position:0% +there was sort of from the last lecture +and it's very similar to this yeah + + align:start position:0% + + + + align:start position:0% + +>> sorry why + + align:start position:0% + + + + align:start position:0% + +Yeah. Okay. So this is because um + + align:start position:0% +Yeah. Okay. So this is because um + + + align:start position:0% +Yeah. Okay. So this is because um +g + + align:start position:0% +g + + + align:start position:0% +g +of x is for is supposed to be not equal + + align:start position:0% +of x is for is supposed to be not equal + + + align:start position:0% +of x is for is supposed to be not equal +to x for all x. + + align:start position:0% + + + + align:start position:0% + +Right? And now I'm fixing x. Okay? So + + align:start position:0% +Right? And now I'm fixing x. Okay? So + + + align:start position:0% +Right? And now I'm fixing x. Okay? So +this here is non zero. Then I'm letting + + align:start position:0% +this here is non zero. Then I'm letting + + + align:start position:0% +this here is non zero. Then I'm letting +y go to a but then this here goes to + + align:start position:0% +y go to a but then this here goes to + + + align:start position:0% +y go to a but then this here goes to +zero by assumption. + + align:start position:0% +zero by assumption. + + + align:start position:0% +zero by assumption. +Right? So you see that if you're fixing + + align:start position:0% +Right? So you see that if you're fixing + + + align:start position:0% +Right? So you see that if you're fixing +X and you just take a Y sufficiently + + align:start position:0% +X and you just take a Y sufficiently + + + align:start position:0% +X and you just take a Y sufficiently +close to A, then this denominator is + + align:start position:0% +close to A, then this denominator is + + + align:start position:0% +close to A, then this denominator is +definitely not zero. Right? You really + + align:start position:0% +definitely not zero. Right? You really + + + align:start position:0% +definitely not zero. Right? You really +want to let this you want to let Y goes + + align:start position:0% +want to let this you want to let Y goes + + + align:start position:0% +want to let this you want to let Y goes +to A because then this here is + + align:start position:0% +to A because then this here is + + + align:start position:0% +to A because then this here is +eliminated, right? This is not part of + + align:start position:0% +eliminated, right? This is not part of + + + align:start position:0% +eliminated, right? This is not part of +the statement the G of Y, right? Okay. + + align:start position:0% +the statement the G of Y, right? Okay. + + + align:start position:0% +the statement the G of Y, right? Okay. +And so again, as long as we started with + + align:start position:0% +And so again, as long as we started with + + + align:start position:0% +And so again, as long as we started with +a x that was sufficiently close to if x + + align:start position:0% +a x that was sufficiently close to if x + + + align:start position:0% +a x that was sufficiently close to if x +was in this interval, then x0 is even + + align:start position:0% +was in this interval, then x0 is even + + + align:start position:0% +was in this interval, then x0 is even +further to the left. So this is also in + + align:start position:0% +further to the left. So this is also in + + + align:start position:0% +further to the left. So this is also in +this interval. We don't know exactly + + align:start position:0% +this interval. We don't know exactly + + + align:start position:0% +this interval. We don't know exactly +what x0 is, but it is in that interval. + + align:start position:0% +what x0 is, but it is in that interval. + + + align:start position:0% +what x0 is, but it is in that interval. +And so this means that this is strictly + + align:start position:0% +And so this means that this is strictly + + + align:start position:0% +And so this means that this is strictly +smaller than epsilon. + + align:start position:0% + + + + align:start position:0% + +Okay. So, + + align:start position:0% +Okay. So, + + + align:start position:0% +Okay. So, +another thing we talked about last time + + align:start position:0% +another thing we talked about last time + + + align:start position:0% +another thing we talked about last time +was this with the tail expansion. + + align:start position:0% +was this with the tail expansion. + + + align:start position:0% +was this with the tail expansion. +Uh, + + align:start position:0% +Uh, + + + align:start position:0% +Uh, +and right and that all of these things + + align:start position:0% +and right and that all of these things + + + align:start position:0% +and right and that all of these things +really came out of this uh bodice + + align:start position:0% +really came out of this uh bodice + + + align:start position:0% +really came out of this uh bodice +theorem + + align:start position:0% +theorem + + + align:start position:0% +theorem +uh and and and that was also the case + + align:start position:0% +uh and and and that was also the case + + + align:start position:0% +uh and and and that was also the case +for the tail expansion. + + align:start position:0% +for the tail expansion. + + + align:start position:0% +for the tail expansion. +So, you have a function f. So this is + + align:start position:0% +So, you have a function f. So this is + + + align:start position:0% +So, you have a function f. So this is +just to remind you about the tail + + align:start position:0% +just to remind you about the tail + + + align:start position:0% +just to remind you about the tail +expansion. + + align:start position:0% + + + + align:start position:0% + +So you have a function + + align:start position:0% +So you have a function + + + align:start position:0% +So you have a function +uh f + + align:start position:0% + + + + align:start position:0% + +and let's say that is defined on some + + align:start position:0% +and let's say that is defined on some + + + align:start position:0% +and let's say that is defined on some +interval here + + align:start position:0% +interval here + + + align:start position:0% +interval here +into r and the function is so f here is + + align:start position:0% +into r and the function is so f here is + + + align:start position:0% +into r and the function is so f here is +uh k times + + align:start position:0% + + + + align:start position:0% + +differentiable + + align:start position:0% + + + + align:start position:0% + +So this means that that fprime exist + + align:start position:0% +So this means that that fprime exist + + + align:start position:0% +So this means that that fprime exist +fprime up to + + align:start position:0% +fprime up to + + + align:start position:0% +fprime up to +the k derivative right. So they all + + align:start position:0% +the k derivative right. So they all + + + align:start position:0% +the k derivative right. So they all +exist. + + align:start position:0% + + + + align:start position:0% + +Uh and then the + + align:start position:0% +Uh and then the + + + align:start position:0% +Uh and then the +statement was so then you looked at the + + align:start position:0% +statement was so then you looked at the + + + align:start position:0% +statement was so then you looked at the +k minus one this is the k minus one + + align:start position:0% + + + + align:start position:0% + +tail polomium + + align:start position:0% + + + + align:start position:0% + +and uh and it was given by that k minus + + align:start position:0% +and uh and it was given by that k minus + + + align:start position:0% +and uh and it was given by that k minus +one of x is equal to and now you're + + align:start position:0% +one of x is equal to and now you're + + + align:start position:0% +one of x is equal to and now you're +summing here from i =0 to k minus one + + align:start position:0% +summing here from i =0 to k minus one + + + align:start position:0% +summing here from i =0 to k minus one +and you take the i derivative this is + + align:start position:0% +and you take the i derivative this is + + + align:start position:0% +and you take the i derivative this is +sorry this is the i derivative + + align:start position:0% +sorry this is the i derivative + + + align:start position:0% +sorry this is the i derivative +uh of f and you do this in a and you + + align:start position:0% +uh of f and you do this in a and you + + + align:start position:0% +uh of f and you do this in a and you +divide by a factorial and then you're + + align:start position:0% +divide by a factorial and then you're + + + align:start position:0% +divide by a factorial and then you're +looking at uh at x - a to the power i + + align:start position:0% +looking at uh at x - a to the power i + + + align:start position:0% +looking at uh at x - a to the power i +right So this was this was the k minus + + align:start position:0% +right So this was this was the k minus + + + align:start position:0% +right So this was this was the k minus +one tail + + align:start position:0% + + + + align:start position:0% + +and then uh the tail expansion + + align:start position:0% +and then uh the tail expansion + + + align:start position:0% +and then uh the tail expansion +tail expansion just told you that uh + + align:start position:0% +tail expansion just told you that uh + + + align:start position:0% +tail expansion just told you that uh +that um + + align:start position:0% +that um + + + align:start position:0% +that um +that uh f here + + align:start position:0% +that uh f here + + + align:start position:0% +that uh f here +at some x was equal to + + align:start position:0% +at some x was equal to + + + align:start position:0% +at some x was equal to +uh p + + align:start position:0% +uh p + + + align:start position:0% +uh p +k minus one it's tail up polinomial plus + + align:start position:0% +k minus one it's tail up polinomial plus + + + align:start position:0% +k minus one it's tail up polinomial plus +and then this is what is usually + + align:start position:0% +and then this is what is usually + + + align:start position:0% +and then this is what is usually +referred to as a remainder term + + align:start position:0% + + + + align:start position:0% + +and this was uh the this looked very + + align:start position:0% +and this was uh the this looked very + + + align:start position:0% +and this was uh the this looked very +similar to one of these terms. It was + + align:start position:0% +similar to one of these terms. It was + + + align:start position:0% +similar to one of these terms. It was +the k derivative + + align:start position:0% + + + + align:start position:0% + +of f but then it was evaluated at a + + align:start position:0% +of f but then it was evaluated at a + + + align:start position:0% +of f but then it was evaluated at a +point c + + align:start position:0% +point c + + + align:start position:0% +point c +uh divided by k factorial + + align:start position:0% +uh divided by k factorial + + + align:start position:0% +uh divided by k factorial +time uh time um x minus + + align:start position:0% +time uh time um x minus + + + align:start position:0% +time uh time um x minus +uh a to the power k + + align:start position:0% +uh a to the power k + + + align:start position:0% +uh a to the power k +and c here was supposed to lie between a + + align:start position:0% +and c here was supposed to lie between a + + + align:start position:0% +and c here was supposed to lie between a +and X. + + align:start position:0% +and X. + + + align:start position:0% +and X. +Okay. So that was the this was the this + + align:start position:0% +Okay. So that was the this was the this + + + align:start position:0% +Okay. So that was the this was the this +is the tail expansion theorem right + + align:start position:0% +is the tail expansion theorem right + + + align:start position:0% +is the tail expansion theorem right +and and so the thing is that so why is + + align:start position:0% +and and so the thing is that so why is + + + align:start position:0% +and and so the thing is that so why is +this so useful and it is extremely + + align:start position:0% +this so useful and it is extremely + + + align:start position:0% +this so useful and it is extremely +useful uh in many different settings + + align:start position:0% +useful uh in many different settings + + + align:start position:0% +useful uh in many different settings +also in much more general settings than + + align:start position:0% +also in much more general settings than + + + align:start position:0% +also in much more general settings than +what I'm describing here and that is + + align:start position:0% +what I'm describing here and that is + + + align:start position:0% +what I'm describing here and that is +because that if you take a function here + + align:start position:0% +because that if you take a function here + + + align:start position:0% +because that if you take a function here +then um and it may be a very complicated + + align:start position:0% +then um and it may be a very complicated + + + align:start position:0% +then um and it may be a very complicated +function but this tail expansion theorem + + align:start position:0% +function but this tail expansion theorem + + + align:start position:0% +function but this tail expansion theorem +tells you that it is it is close to if + + align:start position:0% +tells you that it is it is close to if + + + align:start position:0% +tells you that it is it is close to if +you want to evaluate it at some X + + align:start position:0% +you want to evaluate it at some X + + + align:start position:0% +you want to evaluate it at some X +you can evaluate the tail polinom that's + + align:start position:0% +you can evaluate the tail polinom that's + + + align:start position:0% +you can evaluate the tail polinom that's +after all just a polinomial so that's + + align:start position:0% +after all just a polinomial so that's + + + align:start position:0% +after all just a polinomial so that's +easy to evaluate + + align:start position:0% +easy to evaluate + + + align:start position:0% +easy to evaluate +and then you get within this remainder + + align:start position:0% +and then you get within this remainder + + + align:start position:0% +and then you get within this remainder +term of the right answer okay so that's + + align:start position:0% +term of the right answer okay so that's + + + align:start position:0% +term of the right answer okay so that's +how it always is used + + align:start position:0% +how it always is used + + + align:start position:0% +how it always is used +and so the question is now the natural + + align:start position:0% +and so the question is now the natural + + + align:start position:0% +and so the question is now the natural +question is how well does the tail + + align:start position:0% +question is how well does the tail + + + align:start position:0% +question is how well does the tail +polomial + + align:start position:0% +polomial + + + align:start position:0% +polomial +uh approximate + + align:start position:0% +uh approximate + + + align:start position:0% +uh approximate +the value of the given function. + + align:start position:0% + + + + align:start position:0% + +Right? So, so how + + align:start position:0% +Right? So, so how + + + align:start position:0% +Right? So, so how +well + + align:start position:0% +well + + + align:start position:0% +well +does the tail upon + + align:start position:0% + + + + align:start position:0% + +uh approximate + + align:start position:0% + + + + align:start position:0% + +the the function. + + align:start position:0% + + + + align:start position:0% + +Okay. and and of course to to um to + + align:start position:0% +Okay. and and of course to to um to + + + align:start position:0% +Okay. and and of course to to um to +understand that you need to estimate the + + align:start position:0% +understand that you need to estimate the + + + align:start position:0% +understand that you need to estimate the +remainder term. Let me write the + + align:start position:0% +remainder term. Let me write the + + + align:start position:0% +remainder term. Let me write the +remainder term here. So this the + + align:start position:0% +remainder term here. So this the + + + align:start position:0% +remainder term here. So this the +remainder term + + align:start position:0% +remainder term + + + align:start position:0% +remainder term +um + + align:start position:0% +um + + + align:start position:0% +um +right so the remainder term is + + align:start position:0% +right so the remainder term is + + + align:start position:0% +right so the remainder term is +um so I write this here as uh so it + + align:start position:0% +um so I write this here as uh so it + + + align:start position:0% +um so I write this here as uh so it +really depends on on on x also right but + + align:start position:0% +really depends on on on x also right but + + + align:start position:0% +really depends on on on x also right but +I would just write it like this thing + + align:start position:0% +I would just write it like this thing + + + align:start position:0% +I would just write it like this thing +here so by this I mean the k derivative + + align:start position:0% +here so by this I mean the k derivative + + + align:start position:0% +here so by this I mean the k derivative +of f + + align:start position:0% +of f + + + align:start position:0% +of f +in c divided by k factorial and then x + + align:start position:0% +in c divided by k factorial and then x + + + align:start position:0% +in c divided by k factorial and then x +minus a to the power k. + + align:start position:0% +minus a to the power k. + + + align:start position:0% +minus a to the power k. +So again it depends on really also on + + align:start position:0% +So again it depends on really also on + + + align:start position:0% +So again it depends on really also on +it. Of course it depend on a but it also + + align:start position:0% +it. Of course it depend on a but it also + + + align:start position:0% +it. Of course it depend on a but it also +depends on x right and it's this thing + + align:start position:0% +depends on x right and it's this thing + + + align:start position:0% +depends on x right and it's this thing +here. The thing the the catch here is + + align:start position:0% +here. The thing the the catch here is + + + align:start position:0% +here. The thing the the catch here is +that you don't really know what c is + + align:start position:0% +that you don't really know what c is + + + align:start position:0% +that you don't really know what c is +right the only thing you know about c is + + align:start position:0% +right the only thing you know about c is + + + align:start position:0% +right the only thing you know about c is +that c is lying between uh a and x. So + + align:start position:0% +that c is lying between uh a and x. So + + + align:start position:0% +that c is lying between uh a and x. So +this is essentially all you need, all + + align:start position:0% +this is essentially all you need, all + + + align:start position:0% +this is essentially all you need, all +you know + + align:start position:0% + + + + align:start position:0% + +about C. + + align:start position:0% +about C. + + + align:start position:0% +about C. +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +So now let's look at some examples. + + align:start position:0% +So now let's look at some examples. + + + align:start position:0% +So now let's look at some examples. +Let's look at two examples. So the the + + align:start position:0% +Let's look at two examples. So the the + + + align:start position:0% +Let's look at two examples. So the the +first one is like a promising example + + align:start position:0% +first one is like a promising example + + + align:start position:0% +first one is like a promising example +and the second one is much less + + align:start position:0% +and the second one is much less + + + align:start position:0% +and the second one is much less +promising. Uh and so uh but and so the + + align:start position:0% +promising. Uh and so uh but and so the + + + align:start position:0% +promising. Uh and so uh but and so the +thing is that that how well it + + align:start position:0% +thing is that that how well it + + + align:start position:0% +thing is that that how well it +approximate really depends on the + + align:start position:0% +approximate really depends on the + + + align:start position:0% +approximate really depends on the +function. Okay. But the first one is is + + align:start position:0% +function. Okay. But the first one is is + + + align:start position:0% +function. Okay. But the first one is is +quite typical though example. + + align:start position:0% +quite typical though example. + + + align:start position:0% +quite typical though example. +So suppose that the function f ofx is + + align:start position:0% +So suppose that the function f ofx is + + + align:start position:0% +So suppose that the function f ofx is +the exponential function. + + align:start position:0% +the exponential function. + + + align:start position:0% +the exponential function. +Um and then we have that the derivative + + align:start position:0% +Um and then we have that the derivative + + + align:start position:0% +Um and then we have that the derivative +is just the exponential function itself. + + align:start position:0% +is just the exponential function itself. + + + align:start position:0% +is just the exponential function itself. +So this means that if you take the + + align:start position:0% +So this means that if you take the + + + align:start position:0% +So this means that if you take the +derivative k times + + align:start position:0% + + + + align:start position:0% + +then you just get the function itself. + + align:start position:0% + + + + align:start position:0% + +So this means that the k minus one + + align:start position:0% +So this means that the k minus one + + + align:start position:0% +So this means that the k minus one +this means that a k minus one tail + + align:start position:0% +this means that a k minus one tail + + + align:start position:0% +this means that a k minus one tail +polinomial + + align:start position:0% +polinomial + + + align:start position:0% +polinomial +right this is just the value of the + + align:start position:0% +right this is just the value of the + + + align:start position:0% +right this is just the value of the +function I'll just write it out here so + + align:start position:0% +function I'll just write it out here so + + + align:start position:0% +function I'll just write it out here so +this is the value and now I do it uh I + + align:start position:0% +this is the value and now I do it uh I + + + align:start position:0% +this is the value and now I do it uh I +do it for a equal to uh zero + + align:start position:0% +do it for a equal to uh zero + + + align:start position:0% +do it for a equal to uh zero +and I'm assuming that b here so I'm + + align:start position:0% +and I'm assuming that b here so I'm + + + align:start position:0% +and I'm assuming that b here so I'm +thinking about I will think about this + + align:start position:0% +thinking about I will think about this + + + align:start position:0% +thinking about I will think about this +function here f ofx + + align:start position:0% +function here f ofx + + + align:start position:0% +function here f ofx +uh on on the this function the + + align:start position:0% +uh on on the this function the + + + align:start position:0% +uh on on the this function the +exponential function I'm going to sing + + align:start position:0% +exponential function I'm going to sing + + + align:start position:0% +exponential function I'm going to sing +about it on the interval say from uh + + align:start position:0% +about it on the interval say from uh + + + align:start position:0% +about it on the interval say from uh +minus1 to one + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% + + + + align:start position:0% + +um into r maybe maybe I will maybe I'll + + align:start position:0% +um into r maybe maybe I will maybe I'll + + + align:start position:0% +um into r maybe maybe I will maybe I'll +just take it from zero to one into r + + align:start position:0% +just take it from zero to one into r + + + align:start position:0% +just take it from zero to one into r +Um okay so the and the tail polinomial + + align:start position:0% +Um okay so the and the tail polinomial + + + align:start position:0% +Um okay so the and the tail polinomial +so I'm going to so so so the tailum one + + align:start position:0% +so I'm going to so so so the tailum one + + + align:start position:0% +so I'm going to so so so the tailum one +also talk about that this + + align:start position:0% +also talk about that this + + + align:start position:0% +also talk about that this +tail polinomium is expanded around a + + align:start position:0% +tail polinomium is expanded around a + + + align:start position:0% +tail polinomium is expanded around a +okay so we talk about that the tail + + align:start position:0% +okay so we talk about that the tail + + + align:start position:0% +okay so we talk about that the tail +polom so we talk about tail expansion + + align:start position:0% + + + + align:start position:0% + +around + + align:start position:0% + + + + align:start position:0% + +uh A. Okay. And this just refer to that + + align:start position:0% +uh A. Okay. And this just refer to that + + + align:start position:0% +uh A. Okay. And this just refer to that +when when you plug in A here, well then + + align:start position:0% +when when you plug in A here, well then + + + align:start position:0% +when when you plug in A here, well then +of course you have exact equality, + + align:start position:0% +of course you have exact equality, + + + align:start position:0% +of course you have exact equality, +right? And that all of the derivative + + align:start position:0% +right? And that all of the derivative + + + align:start position:0% +right? And that all of the derivative +are evaluated at A. Okay? So it's really + + align:start position:0% +are evaluated at A. Okay? So it's really + + + align:start position:0% +are evaluated at A. Okay? So it's really +like the tail polom. It's only a good + + align:start position:0% +like the tail polom. It's only a good + + + align:start position:0% +like the tail polom. It's only a good +approximation near A. Right? So I want + + align:start position:0% +approximation near A. Right? So I want + + + align:start position:0% +approximation near A. Right? So I want +now to tail expand + + align:start position:0% +now to tail expand + + + align:start position:0% +now to tail expand +uh near uh the zero + + align:start position:0% +uh near uh the zero + + + align:start position:0% +uh near uh the zero +and so um so right so the value here of + + align:start position:0% +and so um so right so the value here of + + + align:start position:0% +and so um so right so the value here of +the function is one at zero the + + align:start position:0% +the function is one at zero the + + + align:start position:0% +the function is one at zero the +derivative is right so it's the + + align:start position:0% +derivative is right so it's the + + + align:start position:0% +derivative is right so it's the +derivative is also one because it's just + + align:start position:0% +derivative is also one because it's just + + + align:start position:0% +derivative is also one because it's just +a function itself and so this is so you + + align:start position:0% +a function itself and so this is so you + + + align:start position:0% +a function itself and so this is so you +get x and then you get the next Uh the + + align:start position:0% +get x and then you get the next Uh the + + + align:start position:0% +get x and then you get the next Uh the +next uh element in the tail expansion is + + align:start position:0% +next uh element in the tail expansion is + + + align:start position:0% +next uh element in the tail expansion is +x^2 / 2 + x^2 + + align:start position:0% +x^2 / 2 + x^2 + + + align:start position:0% +x^2 / 2 + x^2 +over 3 factorial + + align:start position:0% +over 3 factorial + + + align:start position:0% +over 3 factorial +and then uh x 4 over 4 factorial etc up + + align:start position:0% +and then uh x 4 over 4 factorial etc up + + + align:start position:0% +and then uh x 4 over 4 factorial etc up +to x ^ k minus one over u uh k minus one + + align:start position:0% +to x ^ k minus one over u uh k minus one + + + align:start position:0% +to x ^ k minus one over u uh k minus one +factorial right so this is the a tail + + align:start position:0% +factorial right so this is the a tail + + + align:start position:0% +factorial right so this is the a tail +expansion + + align:start position:0% +expansion + + + align:start position:0% +expansion +or take k minus one tail polomial + + align:start position:0% +or take k minus one tail polomial + + + align:start position:0% +or take k minus one tail polomial +uh around zero. Okay. + + align:start position:0% +uh around zero. Okay. + + + align:start position:0% +uh around zero. Okay. +And so now if you're interested in + + align:start position:0% +And so now if you're interested in + + + align:start position:0% +And so now if you're interested in +evaluating + + align:start position:0% +evaluating + + + align:start position:0% +evaluating +p you want to say how well does this + + align:start position:0% +p you want to say how well does this + + + align:start position:0% +p you want to say how well does this +here approximate + + align:start position:0% +here approximate + + + align:start position:0% +here approximate +uh the original function the exponential + + align:start position:0% +uh the original function the exponential + + + align:start position:0% +uh the original function the exponential +function. So you want to bound this + + align:start position:0% +function. So you want to bound this + + + align:start position:0% +function. So you want to bound this +thing here right? So you want to have a + + align:start position:0% +thing here right? So you want to have a + + + align:start position:0% +thing here right? So you want to have a +bound for that. Well the thing again is + + align:start position:0% +bound for that. Well the thing again is + + + align:start position:0% +bound for that. Well the thing again is +that f ofx you know that f ofx is equal + + align:start position:0% +that f ofx you know that f ofx is equal + + + align:start position:0% +that f ofx you know that f ofx is equal +to this tail polomial + + align:start position:0% +to this tail polomial + + + align:start position:0% +to this tail polomial +and then plus this remainder term + + align:start position:0% +and then plus this remainder term + + + align:start position:0% +and then plus this remainder term +right in the c right + + align:start position:0% +right in the c right + + + align:start position:0% +right in the c right +now c again has to lie will c will lie + + align:start position:0% +now c again has to lie will c will lie + + + align:start position:0% +now c again has to lie will c will lie +between + + align:start position:0% +between + + + align:start position:0% +between +a and x. In this case a is zero. + + align:start position:0% +a and x. In this case a is zero. + + + align:start position:0% +a and x. In this case a is zero. +So it means that c here. + + align:start position:0% + + + + align:start position:0% + +So this means that here here c here is + + align:start position:0% +So this means that here here c here is + + + align:start position:0% +So this means that here here c here is +between zero and x. Right? + + align:start position:0% +between zero and x. Right? + + + align:start position:0% +between zero and x. Right? +And the remainder term here + + align:start position:0% +And the remainder term here + + + align:start position:0% +And the remainder term here +this here was + + align:start position:0% +this here was + + + align:start position:0% +this here was +was equal to that you took the k + + align:start position:0% +was equal to that you took the k + + + align:start position:0% +was equal to that you took the k +derivative of the function. So in this + + align:start position:0% +derivative of the function. So in this + + + align:start position:0% +derivative of the function. So in this +case the k derivative of the function is + + align:start position:0% +case the k derivative of the function is + + + align:start position:0% +case the k derivative of the function is +the function itself. So this here is the + + align:start position:0% +the function itself. So this here is the + + + align:start position:0% +the function itself. So this here is the +value of the k derivative and this is uh + + align:start position:0% +value of the k derivative and this is uh + + + align:start position:0% +value of the k derivative and this is uh +at c this is the k derivative of the + + align:start position:0% +at c this is the k derivative of the + + + align:start position:0% +at c this is the k derivative of the +original function and then you have to + + align:start position:0% +original function and then you have to + + + align:start position:0% +original function and then you have to +divide by a k factorial and then it's x + + align:start position:0% +divide by a k factorial and then it's x + + + align:start position:0% +divide by a k factorial and then it's x +to the power + + align:start position:0% +to the power + + + align:start position:0% +to the power +uh k like that + + align:start position:0% +uh k like that + + + align:start position:0% +uh k like that +right + + align:start position:0% +right + + + align:start position:0% +right +and so you see that if if x here is now + + align:start position:0% +and so you see that if if x here is now + + + align:start position:0% +and so you see that if if x here is now +between zero and one. This means that + + align:start position:0% +between zero and one. This means that + + + align:start position:0% +between zero and one. This means that +this thing here, this + + align:start position:0% +this thing here, this + + + align:start position:0% +this thing here, this +remainder term here, the absolute value + + align:start position:0% +remainder term here, the absolute value + + + align:start position:0% +remainder term here, the absolute value +is so c here is less than one. So this + + align:start position:0% +is so c here is less than one. So this + + + align:start position:0% +is so c here is less than one. So this +means that this thing here is less than + + align:start position:0% +means that this thing here is less than + + + align:start position:0% +means that this thing here is less than +e. So it's less or equal to e divided by + + align:start position:0% +e. So it's less or equal to e divided by + + + align:start position:0% +e. So it's less or equal to e divided by +k factorial. This here is bounded by + + align:start position:0% +k factorial. This here is bounded by + + + align:start position:0% +k factorial. This here is bounded by +since x is bounded by one, this is + + align:start position:0% +since x is bounded by one, this is + + + align:start position:0% +since x is bounded by one, this is +bounded by one. So you're getting this + + align:start position:0% +bounded by one. So you're getting this + + + align:start position:0% +bounded by one. So you're getting this +inequality here, right? And so you see + + align:start position:0% +inequality here, right? And so you see + + + align:start position:0% +inequality here, right? And so you see +that if K is is very large, this is a + + align:start position:0% +that if K is is very large, this is a + + + align:start position:0% +that if K is is very large, this is a +tiny number, right? So it's a really + + align:start position:0% +tiny number, right? So it's a really + + + align:start position:0% +tiny number, right? So it's a really +good approximation. I mean, you don't + + align:start position:0% +good approximation. I mean, you don't + + + align:start position:0% +good approximation. I mean, you don't +even need to make K very large because + + align:start position:0% +even need to make K very large because + + + align:start position:0% +even need to make K very large because +it's exponential, right? Not + + align:start position:0% +it's exponential, right? Not + + + align:start position:0% +it's exponential, right? Not +exponential, it's factorial. Yeah. + + align:start position:0% +exponential, it's factorial. Yeah. + + + align:start position:0% +exponential, it's factorial. Yeah. +Right. + + align:start position:0% + + + + align:start position:0% + +Okay. So that's a kind of encouraging + + align:start position:0% +Okay. So that's a kind of encouraging + + + align:start position:0% +Okay. So that's a kind of encouraging +example. Let's say that the the tail + + align:start position:0% +example. Let's say that the the tail + + + align:start position:0% +example. Let's say that the the tail +expansion uh is is a very in this case + + align:start position:0% +expansion uh is is a very in this case + + + align:start position:0% +expansion uh is is a very in this case +is a very good approximation to the + + align:start position:0% +is a very good approximation to the + + + align:start position:0% +is a very good approximation to the +function. + + align:start position:0% +function. + + + align:start position:0% +function. +Uh the another example that is less + + align:start position:0% +Uh the another example that is less + + + align:start position:0% +Uh the another example that is less +encouraging and so again the moral is + + align:start position:0% +encouraging and so again the moral is + + + align:start position:0% +encouraging and so again the moral is +that how well the tail expansion + + align:start position:0% +that how well the tail expansion + + + align:start position:0% +that how well the tail expansion +approximate the function depend on the + + align:start position:0% +approximate the function depend on the + + + align:start position:0% +approximate the function depend on the +function. So suppose that the function + + align:start position:0% +function. So suppose that the function + + + align:start position:0% +function. So suppose that the function +here was + + align:start position:0% +here was + + + align:start position:0% +here was +uh was a function that was zero here. + + align:start position:0% +uh was a function that was zero here. + + + align:start position:0% +uh was a function that was zero here. +When x is less than zero less or equal + + align:start position:0% +When x is less than zero less or equal + + + align:start position:0% +When x is less than zero less or equal +to zero and when x is bigger than zero + + align:start position:0% +to zero and when x is bigger than zero + + + align:start position:0% +to zero and when x is bigger than zero +then it is e to the minus 1 /x^2. + + align:start position:0% +then it is e to the minus 1 /x^2. + + + align:start position:0% +then it is e to the minus 1 /x^2. +Okay. So you see that when x becomes + + align:start position:0% +Okay. So you see that when x becomes + + + align:start position:0% +Okay. So you see that when x becomes +very very small + + align:start position:0% +very very small + + + align:start position:0% +very very small +you are looking at one over this + + align:start position:0% +you are looking at one over this + + + align:start position:0% +you are looking at one over this +squared. So this here is huge + + align:start position:0% +squared. So this here is huge + + + align:start position:0% +squared. So this here is huge +right but now it's with a minus sign. So + + align:start position:0% +right but now it's with a minus sign. So + + + align:start position:0% +right but now it's with a minus sign. So +this means that this thing here is + + align:start position:0% +this means that this thing here is + + + align:start position:0% +this means that this thing here is +incredibly small right and so it's + + align:start position:0% +incredibly small right and so it's + + + align:start position:0% +incredibly small right and so it's +clearly it's clear that this function + + align:start position:0% +clearly it's clear that this function + + + align:start position:0% +clearly it's clear that this function +here is continuous at zero. It's clearly + + align:start position:0% +here is continuous at zero. It's clearly + + + align:start position:0% +here is continuous at zero. It's clearly +continuous everywhere else. But actually + + align:start position:0% +continuous everywhere else. But actually + + + align:start position:0% +continuous everywhere else. But actually +it's you know sort of using in this sort + + align:start position:0% +it's you know sort of using in this sort + + + align:start position:0% +it's you know sort of using in this sort +of argument it's easy to see that this + + align:start position:0% +of argument it's easy to see that this + + + align:start position:0% +of argument it's easy to see that this +function f here is uh infinite + + align:start position:0% +function f here is uh infinite + + + align:start position:0% +function f here is uh infinite +differentiable. + + align:start position:0% +differentiable. + + + align:start position:0% +differentiable. +So it's you can differentiate it + + align:start position:0% +So it's you can differentiate it + + + align:start position:0% +So it's you can differentiate it +infinitely many times and even at zero. + + align:start position:0% +infinitely many times and even at zero. + + + align:start position:0% +infinitely many times and even at zero. +Okay. + + align:start position:0% + + + + align:start position:0% + +and and by it and of course the + + align:start position:0% +and and by it and of course the + + + align:start position:0% +and and by it and of course the +derivative + + align:start position:0% +derivative + + + align:start position:0% +derivative +uh the derivative is right so it's an + + align:start position:0% +uh the derivative is right so it's an + + + align:start position:0% +uh the derivative is right so it's an +example of a function that looks like + + align:start position:0% +example of a function that looks like + + + align:start position:0% +example of a function that looks like +this is zero until zero and then it goes + + align:start position:0% +this is zero until zero and then it goes + + + align:start position:0% +this is zero until zero and then it goes +up like this right and so the derivative + + align:start position:0% +up like this right and so the derivative + + + align:start position:0% +up like this right and so the derivative +at zero + + align:start position:0% +at zero + + + align:start position:0% +at zero +is zero any derivative however many + + align:start position:0% +is zero any derivative however many + + + align:start position:0% +is zero any derivative however many +times you take the derivative of this + + align:start position:0% +times you take the derivative of this + + + align:start position:0% +times you take the derivative of this +function + + align:start position:0% +function + + + align:start position:0% +function +sorry + + align:start position:0% +sorry + + + align:start position:0% +sorry +this thing here + + align:start position:0% +this thing here + + + align:start position:0% +this thing here +if you take any derivative and you + + align:start position:0% +if you take any derivative and you + + + align:start position:0% +if you take any derivative and you +evaluate at zero, you always get zero, + + align:start position:0% +evaluate at zero, you always get zero, + + + align:start position:0% +evaluate at zero, you always get zero, +right? + + align:start position:0% + + + + align:start position:0% + +So, so this means that if you're looking + + align:start position:0% +So, so this means that if you're looking + + + align:start position:0% +So, so this means that if you're looking +at the tail expansion + + align:start position:0% + + + + align:start position:0% + +at zero, so you're looking at this k + + align:start position:0% +at zero, so you're looking at this k + + + align:start position:0% +at zero, so you're looking at this k +minus one tailor polomial. + + align:start position:0% + + + + align:start position:0% + +This polomial is all of the coefficient + + align:start position:0% +This polomial is all of the coefficient + + + align:start position:0% +This polomial is all of the coefficient +in the polinomial are zero right. So + + align:start position:0% +in the polinomial are zero right. So + + + align:start position:0% +in the polinomial are zero right. So +this polinomial is just zero. So this + + align:start position:0% +this polinomial is just zero. So this + + + align:start position:0% +this polinomial is just zero. So this +means that + + align:start position:0% +means that + + + align:start position:0% +means that +if you're looking at + + align:start position:0% +if you're looking at + + + align:start position:0% +if you're looking at +f ofx + + align:start position:0% +f ofx + + + align:start position:0% +f ofx +well f of x is actually equal to this + + align:start position:0% +well f of x is actually equal to this + + + align:start position:0% +well f of x is actually equal to this +remainder term right. So it's somehow + + align:start position:0% +remainder term right. So it's somehow + + + align:start position:0% +remainder term right. So it's somehow +you know the teleport number is like too + + align:start position:0% +you know the teleport number is like too + + + align:start position:0% +you know the teleport number is like too +trivial. It doesn't really help you all + + align:start position:0% +trivial. It doesn't really help you all + + + align:start position:0% +trivial. It doesn't really help you all +that much. Right? So it's equal to this + + align:start position:0% +that much. Right? So it's equal to this + + + align:start position:0% +that much. Right? So it's equal to this +remainder term. + + align:start position:0% +remainder term. + + + align:start position:0% +remainder term. +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +Yeah. + + align:start position:0% +Yeah. + + + align:start position:0% +Yeah. +>> Is there a way of um so like the + + align:start position:0% +>> Is there a way of um so like the + + + align:start position:0% +>> Is there a way of um so like the +remainder like bounding this helps us + + align:start position:0% +remainder like bounding this helps us + + + align:start position:0% +remainder like bounding this helps us +figure out how well the expansion + + align:start position:0% +figure out how well the expansion + + + align:start position:0% +figure out how well the expansion +approximates the actual function. Is + + align:start position:0% +approximates the actual function. Is + + + align:start position:0% +approximates the actual function. Is +there a way to determine like how far + + align:start position:0% +there a way to determine like how far + + + align:start position:0% +there a way to determine like how far +from the point you're approximating like + + align:start position:0% +from the point you're approximating like + + + align:start position:0% +from the point you're approximating like +a or zero in this case you can go a + + align:start position:0% +a or zero in this case you can go a + + + align:start position:0% +a or zero in this case you can go a +>> Yeah. by it. That's right. I mean, so + + align:start position:0% +>> Yeah. by it. That's right. I mean, so + + + align:start position:0% +>> Yeah. by it. That's right. I mean, so +you're asking, right? So you're asking + + align:start position:0% +you're asking, right? So you're asking + + + align:start position:0% +you're asking, right? So you're asking +suppose and you definitely could do + + align:start position:0% +suppose and you definitely could do + + + align:start position:0% +suppose and you definitely could do +this, right? You you asking + + align:start position:0% +this, right? You you asking + + + align:start position:0% +this, right? You you asking +you you you're thinking that you have + + align:start position:0% +you you you're thinking that you have + + + align:start position:0% +you you you're thinking that you have +you have a + + align:start position:0% +you have a + + + align:start position:0% +you have a +you you you're thinking a slightly + + align:start position:0% +you you you're thinking a slightly + + + align:start position:0% +you you you're thinking a slightly +different situation than here but + + align:start position:0% +different situation than here but + + + align:start position:0% +different situation than here but +closely related that you have some a + + align:start position:0% +closely related that you have some a + + + align:start position:0% +closely related that you have some a +here + + align:start position:0% +here + + + align:start position:0% +here +and you have a function f and and you + + align:start position:0% +and you have a function f and and you + + + align:start position:0% +and you have a function f and and you +want to and you are willing to maybe uh + + align:start position:0% +want to and you are willing to maybe uh + + + align:start position:0% +want to and you are willing to maybe uh +look at you're willing to + + align:start position:0% +look at you're willing to + + + align:start position:0% +look at you're willing to +take some fixed large k and then you're + + align:start position:0% +take some fixed large k and then you're + + + align:start position:0% +take some fixed large k and then you're +asking + + align:start position:0% +asking + + + align:start position:0% +asking +um what I'm interested in how well does + + align:start position:0% +um what I'm interested in how well does + + + align:start position:0% +um what I'm interested in how well does +this how well does this function this + + align:start position:0% +this how well does this function this + + + align:start position:0% +this how well does this function this +polomial approximate this but I want it + + align:start position:0% +polomial approximate this but I want it + + + align:start position:0% +polomial approximate this but I want it +within an error certain area right so + + align:start position:0% +within an error certain area right so + + + align:start position:0% +within an error certain area right so +it's a given epsilon and you're + + align:start position:0% +it's a given epsilon and you're + + + align:start position:0% +it's a given epsilon and you're +interested in how far away can you go + + align:start position:0% +interested in how far away can you go + + + align:start position:0% +interested in how far away can you go +from a so that this here is less than + + align:start position:0% +from a so that this here is less than + + + align:start position:0% +from a so that this here is less than +epsilon and so this is so so this + + align:start position:0% +epsilon and so this is so so this + + + align:start position:0% +epsilon and so this is so so this +becomes a question of this remainder + + align:start position:0% +becomes a question of this remainder + + + align:start position:0% +becomes a question of this remainder +term, right? So this becomes a question + + align:start position:0% +term, right? So this becomes a question + + + align:start position:0% +term, right? So this becomes a question +of this remainder term. When can you + + align:start position:0% +of this remainder term. When can you + + + align:start position:0% +of this remainder term. When can you +always say that this remainder term is + + align:start position:0% +always say that this remainder term is + + + align:start position:0% +always say that this remainder term is +less than epsilon + + align:start position:0% +less than epsilon + + + align:start position:0% +less than epsilon +and so like in this particular you would + + align:start position:0% +and so like in this particular you would + + + align:start position:0% +and so like in this particular you would +have to do it on a casebyase basis. Uh + + align:start position:0% +have to do it on a casebyase basis. Uh + + + align:start position:0% +have to do it on a casebyase basis. Uh +but in this particular case the + + align:start position:0% +but in this particular case the + + + align:start position:0% +but in this particular case the +remainder term is right if this interval + + align:start position:0% +remainder term is right if this interval + + + align:start position:0% +remainder term is right if this interval +here in the in that example over there + + align:start position:0% +here in the in that example over there + + + align:start position:0% +here in the in that example over there +if if you if you have here zero this was + + align:start position:0% +if if you if you have here zero this was + + + align:start position:0% +if if you if you have here zero this was +a in our example and then you want to go + + align:start position:0% +a in our example and then you want to go + + + align:start position:0% +a in our example and then you want to go +out here to some x + + align:start position:0% +out here to some x + + + align:start position:0% +out here to some x +and now you know that c here is between + + align:start position:0% +and now you know that c here is between + + + align:start position:0% +and now you know that c here is between +zero and x but you don't really know + + align:start position:0% +zero and x but you don't really know + + + align:start position:0% +zero and x but you don't really know +anything else right so then it's like + + align:start position:0% +anything else right so then it's like + + + align:start position:0% +anything else right so then it's like +this remainder term you will have this + + align:start position:0% +this remainder term you will have this + + + align:start position:0% +this remainder term you will have this +remainder term in this example + + align:start position:0% +remainder term in this example + + + align:start position:0% +remainder term in this example +uh at this c here this again was equal + + align:start position:0% +uh at this c here this again was equal + + + align:start position:0% +uh at this c here this again was equal +to this thing here over k factorial + + align:start position:0% + + + + align:start position:0% + +and so you would have that you would + + align:start position:0% +and so you would have that you would + + + align:start position:0% +and so you would have that you would +want this thing here + + align:start position:0% +want this thing here + + + align:start position:0% +want this thing here +r k + + align:start position:0% +r k + + + align:start position:0% +r k +you would want this to be less than + + align:start position:0% +you would want this to be less than + + + align:start position:0% +you would want this to be less than +epsilon and so you would have that this + + align:start position:0% +epsilon and so you would have that this + + + align:start position:0% +epsilon and so you would have that this +thing here the the only the only thing + + align:start position:0% +thing here the the only the only thing + + + align:start position:0% +thing here the the only the only thing +you can really do is that you can say + + align:start position:0% +you can really do is that you can say + + + align:start position:0% +you can really do is that you can say +that C is less or equal to to X for C. + + align:start position:0% +that C is less or equal to to X for C. + + + align:start position:0% +that C is less or equal to to X for C. +>> Yeah, that's right. But that no so so + + align:start position:0% +>> Yeah, that's right. But that no so so + + + align:start position:0% +>> Yeah, that's right. But that no so so +you would do so what you would do here + + align:start position:0% +you would do so what you would do here + + + align:start position:0% +you would do so what you would do here +is you would say R K C this here has to + + align:start position:0% +is you would say R K C this here has to + + + align:start position:0% +is you would say R K C this here has to +be bounded by by because XC is less than + + align:start position:0% +be bounded by by because XC is less than + + + align:start position:0% +be bounded by by because XC is less than +X. So this is E to the X you have to + + align:start position:0% +X. So this is E to the X you have to + + + align:start position:0% +X. So this is E to the X you have to +eliminate C. So, so, so you would do + + align:start position:0% +eliminate C. So, so, so you would do + + + align:start position:0% +eliminate C. So, so, so you would do +like this k factorial * x ^ k you have + + align:start position:0% +like this k factorial * x ^ k you have + + + align:start position:0% +like this k factorial * x ^ k you have +to eliminate uh c right because you + + align:start position:0% +to eliminate uh c right because you + + + align:start position:0% +to eliminate uh c right because you +don't know anything really about c and + + align:start position:0% +don't know anything really about c and + + + align:start position:0% +don't know anything really about c and +so this here now has to be less than + + align:start position:0% +so this here now has to be less than + + + align:start position:0% +so this here now has to be less than +epsilon so now you only have you know + + align:start position:0% +epsilon so now you only have you know + + + align:start position:0% +epsilon so now you only have you know +you have fixed your k and so now you + + align:start position:0% +you have fixed your k and so now you + + + align:start position:0% +you have fixed your k and so now you +only have one variable and you can solve + + align:start position:0% +only have one variable and you can solve + + + align:start position:0% +only have one variable and you can solve +that but you you you really have to + + align:start position:0% +that but you you you really have to + + + align:start position:0% +that but you you you really have to +eliminate change yeah + + align:start position:0% + + + + align:start position:0% + +uh Okay. + + align:start position:0% +uh Okay. + + + align:start position:0% +uh Okay. +Uh so so so again so so the how well the + + align:start position:0% +Uh so so so again so so the how well the + + + align:start position:0% +Uh so so so again so so the how well the +tail expansion approximate depends on + + align:start position:0% +tail expansion approximate depends on + + + align:start position:0% +tail expansion approximate depends on +the function. + + align:start position:0% +the function. + + + align:start position:0% +the function. +Okay. The next topic is another + + align:start position:0% +Okay. The next topic is another + + + align:start position:0% +Okay. The next topic is another +important topic and so this is uh + + align:start position:0% +important topic and so this is uh + + + align:start position:0% +important topic and so this is uh +integrals + + align:start position:0% +integrals + + + align:start position:0% +integrals +and there are + + align:start position:0% +and there are + + + align:start position:0% +and there are +different ways of + + align:start position:0% +different ways of + + + align:start position:0% +different ways of +of um defining integrals. + + align:start position:0% + + + + align:start position:0% + +This here is + + align:start position:0% +This here is + + + align:start position:0% +This here is +um + + align:start position:0% + + + + align:start position:0% + +this here is certainly one of the maybe + + align:start position:0% +this here is certainly one of the maybe + + + align:start position:0% +this here is certainly one of the maybe +the most natural one. + + align:start position:0% +the most natural one. + + + align:start position:0% +the most natural one. +Uh and so this is what's called + + align:start position:0% +Uh and so this is what's called + + + align:start position:0% +Uh and so this is what's called +reman. So it's after German + + align:start position:0% +reman. So it's after German + + + align:start position:0% +reman. So it's after German +mathematicians reman + + align:start position:0% +mathematicians reman + + + align:start position:0% +mathematicians reman +uh integrals. + + align:start position:0% + + + + align:start position:0% + +And so the thing is that here now you + + align:start position:0% +And so the thing is that here now you + + + align:start position:0% +And so the thing is that here now you +look at a function + + align:start position:0% +look at a function + + + align:start position:0% +look at a function +you have a function on some interval + + align:start position:0% +you have a function on some interval + + + align:start position:0% +you have a function on some interval +from a to b + + align:start position:0% +from a to b + + + align:start position:0% +from a to b +into r and this function f here is um is + + align:start position:0% +into r and this function f here is um is + + + align:start position:0% +into r and this function f here is um is +bounded + + align:start position:0% + + + + align:start position:0% + +and the idea is so the idea is for + + align:start position:0% +and the idea is so the idea is for + + + align:start position:0% +and the idea is so the idea is for +integrals is + + align:start position:0% + + + + align:start position:0% + +that so you have a function function + + align:start position:0% +that so you have a function function + + + align:start position:0% +that so you have a function function +and you want to be able to define. So + + align:start position:0% +and you want to be able to define. So + + + align:start position:0% +and you want to be able to define. So +define + + align:start position:0% + + + + align:start position:0% + +uh area + + align:start position:0% + + + + align:start position:0% + +below + + align:start position:0% +below + + + align:start position:0% +below +graph. + + align:start position:0% + + + + align:start position:0% + +So so if this is a function you want to + + align:start position:0% +So so if this is a function you want to + + + align:start position:0% +So so if this is a function you want to +be able to calculate + + align:start position:0% +be able to calculate + + + align:start position:0% +be able to calculate +what is this area. Okay. Now, if the + + align:start position:0% +what is this area. Okay. Now, if the + + + align:start position:0% +what is this area. Okay. Now, if the +function was to if the function was to + + align:start position:0% +function was to if the function was to + + + align:start position:0% +function was to if the function was to +have crossed + + align:start position:0% +have crossed + + + align:start position:0% +have crossed +um the x-axis, then this area here would + + align:start position:0% +um the x-axis, then this area here would + + + align:start position:0% +um the x-axis, then this area here would +count negatively and this area here + + align:start position:0% +count negatively and this area here + + + align:start position:0% +count negatively and this area here +would count positively. Anyway, so this + + align:start position:0% +would count positively. Anyway, so this + + + align:start position:0% +would count positively. Anyway, so this +is this is what you want to do + + align:start position:0% +is this is what you want to do + + + align:start position:0% +is this is what you want to do +and and you always starting with a + + align:start position:0% +and and you always starting with a + + + align:start position:0% +and and you always starting with a +bounded function. + + align:start position:0% +bounded function. + + + align:start position:0% +bounded function. +Now, to do that, right? And so so you + + align:start position:0% +Now, to do that, right? And so so you + + + align:start position:0% +Now, to do that, right? And so so you +want to define that the only thing that + + align:start position:0% +want to define that the only thing that + + + align:start position:0% +want to define that the only thing that +you know for sure is + + align:start position:0% + + + + align:start position:0% + +so so there's only like one ingredient + + align:start position:0% +so so there's only like one ingredient + + + align:start position:0% +so so there's only like one ingredient +you have. + + align:start position:0% + + + + align:start position:0% + +So, + + align:start position:0% + + + + align:start position:0% + +so only + + align:start position:0% +so only + + + align:start position:0% +so only +only thing + + align:start position:0% + + + + align:start position:0% + +uh no you know + + align:start position:0% +uh no you know + + + align:start position:0% +uh no you know +at the outset. + + align:start position:0% + + + + align:start position:0% + +So the only thing you know is that if + + align:start position:0% +So the only thing you know is that if + + + align:start position:0% +So the only thing you know is that if +you take a right angle so if this length + + align:start position:0% +you take a right angle so if this length + + + align:start position:0% +you take a right angle so if this length +here is + + align:start position:0% +here is + + + align:start position:0% +here is +um uh is let's call it D and this here + + align:start position:0% +um uh is let's call it D and this here + + + align:start position:0% +um uh is let's call it D and this here +is E right then you know that the area + + align:start position:0% +is E right then you know that the area + + + align:start position:0% +is E right then you know that the area +here + + align:start position:0% +here + + + align:start position:0% +here +so area + + align:start position:0% + + + + align:start position:0% + +is D * E right okay that's that's the + + align:start position:0% +is D * E right okay that's that's the + + + align:start position:0% +is D * E right okay that's that's the +only thing we have so Now + + align:start position:0% +only thing we have so Now + + + align:start position:0% +only thing we have so Now +how do we define the the area below the + + align:start position:0% +how do we define the the area below the + + + align:start position:0% +how do we define the the area below the +graph? And to do that we first need to + + align:start position:0% +graph? And to do that we first need to + + + align:start position:0% +graph? And to do that we first need to +talk about partitions. + + align:start position:0% + + + + align:start position:0% + +So partition. + + align:start position:0% + + + + align:start position:0% + +So suppose I have a + + align:start position:0% +So suppose I have a + + + align:start position:0% +So suppose I have a +interval here. A and b are real numbers. + + align:start position:0% +interval here. A and b are real numbers. + + + align:start position:0% +interval here. A and b are real numbers. +So I have an interval here. Then I talk + + align:start position:0% +So I have an interval here. Then I talk + + + align:start position:0% +So I have an interval here. Then I talk +about a partition + + align:start position:0% + + + + align:start position:0% + +and and it's useful to have a notation + + align:start position:0% +and and it's useful to have a notation + + + align:start position:0% +and and it's useful to have a notation +for a partition. So I call it P of of + + align:start position:0% +for a partition. So I call it P of of + + + align:start position:0% +for a partition. So I call it P of of +this interval here. + + align:start position:0% +this interval here. + + + align:start position:0% +this interval here. +This is finite is finally many + + align:start position:0% + + + + align:start position:0% + +many dividing points + + align:start position:0% + + + + align:start position:0% + +and the dividing points always have to + + align:start position:0% +and the dividing points always have to + + + align:start position:0% +and the dividing points always have to +start at A and end at B. So you have + + align:start position:0% +start at A and end at B. So you have + + + align:start position:0% +start at A and end at B. So you have +finally many let's say k many and you're + + align:start position:0% +finally many let's say k many and you're + + + align:start position:0% +finally many let's say k many and you're +looking at okay take I'll write it k + + + align:start position:0% +looking at okay take I'll write it k + + + + align:start position:0% +looking at okay take I'll write it k + +one many. So uh the first one has to be + + align:start position:0% +one many. So uh the first one has to be + + + align:start position:0% +one many. So uh the first one has to be +a + + align:start position:0% +a + + + align:start position:0% +a +and then you have uh x1 + + align:start position:0% +and then you have uh x1 + + + align:start position:0% +and then you have uh x1 +up to the last one + + align:start position:0% +up to the last one + + + align:start position:0% +up to the last one +and that has to be b. + + align:start position:0% +and that has to be b. + + + align:start position:0% +and that has to be b. +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +And so + + align:start position:0% +And so + + + align:start position:0% +And so +so what you're thinking about is so you + + align:start position:0% +so what you're thinking about is so you + + + align:start position:0% +so what you're thinking about is so you +have this interval here from a to b and + + align:start position:0% +have this interval here from a to b and + + + align:start position:0% +have this interval here from a to b and +you have these dividing points + + align:start position:0% +you have these dividing points + + + align:start position:0% +you have these dividing points +and you are thinking about dividing the + + align:start position:0% +and you are thinking about dividing the + + + align:start position:0% +and you are thinking about dividing the +the original interval into these sub + + align:start position:0% +the original interval into these sub + + + align:start position:0% +the original interval into these sub +intervals. Right? So these are the sub + + align:start position:0% +intervals. Right? So these are the sub + + + align:start position:0% +intervals. Right? So these are the sub +intervals. Right? So you divide + + align:start position:0% + + + + align:start position:0% + +the original + + align:start position:0% + + + + align:start position:0% + +interval + + align:start position:0% + + + + align:start position:0% + +into + + align:start position:0% +into + + + align:start position:0% +into +sub intervals + + align:start position:0% + + + + align:start position:0% + +and the sub intervals are I'll do it + + align:start position:0% +and the sub intervals are I'll do it + + + align:start position:0% +and the sub intervals are I'll do it +like this. I will do it the where I take + + align:start position:0% +like this. I will do it the where I take + + + align:start position:0% +like this. I will do it the where I take +from it's always from you know one to + + align:start position:0% +from it's always from you know one to + + + align:start position:0% +from it's always from you know one to +the next and I will write it typically + + align:start position:0% +the next and I will write it typically + + + align:start position:0% +the next and I will write it typically +where I'm starting where I'm ending at I + + align:start position:0% +where I'm starting where I'm ending at I + + + align:start position:0% +where I'm starting where I'm ending at I +and beginning at I minus one. + + align:start position:0% +and beginning at I minus one. + + + align:start position:0% +and beginning at I minus one. +So + + align:start position:0% +So + + + align:start position:0% +So +right so I'm dividing it into these sub + + align:start position:0% +right so I'm dividing it into these sub + + + align:start position:0% +right so I'm dividing it into these sub +intervals and so in this case here in + + align:start position:0% +intervals and so in this case here in + + + align:start position:0% +intervals and so in this case here in +this case here where this is x0 + + align:start position:0% +this case here where this is x0 + + + align:start position:0% +this case here where this is x0 +uh there's going to be + + align:start position:0% +uh there's going to be + + + align:start position:0% +uh there's going to be +uh k uh sub intervals okay and it's you + + align:start position:0% +uh k uh sub intervals okay and it's you + + + align:start position:0% +uh k uh sub intervals okay and it's you +know you only + + align:start position:0% +know you only + + + align:start position:0% +know you only +always go from one to the next right so + + align:start position:0% +always go from one to the next right so + + + align:start position:0% +always go from one to the next right so +so that's a partition + + align:start position:0% +so that's a partition + + + align:start position:0% +so that's a partition +and now we need a second notion + + align:start position:0% +and now we need a second notion + + + align:start position:0% +and now we need a second notion +related to this and this is a sub + + align:start position:0% +related to this and this is a sub + + + align:start position:0% +related to this and this is a sub +partition. + + align:start position:0% + + + + align:start position:0% + +So subartetition + + align:start position:0% + + + + align:start position:0% + +subartetition this is also sometime + + align:start position:0% +subartetition this is also sometime + + + align:start position:0% +subartetition this is also sometime +called uh sometimes called + + align:start position:0% + + + + align:start position:0% + +uh + + align:start position:0% +uh + + + align:start position:0% +uh +refinement. + + align:start position:0% + + + + align:start position:0% + +So a sub partition is so if you have a + + align:start position:0% +So a sub partition is so if you have a + + + align:start position:0% +So a sub partition is so if you have a +partition so P1 is a partition + + align:start position:0% + + + + align:start position:0% + +and then P2 is a sub partition of + + align:start position:0% +and then P2 is a sub partition of + + + align:start position:0% +and then P2 is a sub partition of +refinement. + + align:start position:0% + + + + align:start position:0% + +If if + + align:start position:0% +If if + + + align:start position:0% +If if +P2 + + align:start position:0% +P2 + + + align:start position:0% +P2 +has all + + align:start position:0% +has all + + + align:start position:0% +has all +the dividing points + + align:start position:0% + + + + align:start position:0% + +of P1 and then some and then some I mean + + align:start position:0% +of P1 and then some and then some I mean + + + align:start position:0% +of P1 and then some and then some I mean +it right right I mean of course it could + + align:start position:0% +it right right I mean of course it could + + + align:start position:0% +it right right I mean of course it could +be a trivial sub partition where P1 and + + align:start position:0% +be a trivial sub partition where P1 and + + + align:start position:0% +be a trivial sub partition where P1 and +P2 are the same. That's okay. But in + + align:start position:0% +P2 are the same. That's okay. But in + + + align:start position:0% +P2 are the same. That's okay. But in +general, it would have some more points + + align:start position:0% +general, it would have some more points + + + align:start position:0% +general, it would have some more points +also, some more dividing points. Okay. + + align:start position:0% + + + + align:start position:0% + +Now, + + align:start position:0% +Now, + + + align:start position:0% +Now, +um, right. So, now let me look at uh, so + + align:start position:0% +um, right. So, now let me look at uh, so + + + align:start position:0% +um, right. So, now let me look at uh, so +what is then? + + align:start position:0% +what is then? + + + align:start position:0% +what is then? +So, so now let's try to get closer to + + align:start position:0% +So, so now let's try to get closer to + + + align:start position:0% +So, so now let's try to get closer to +try to define this with the area below + + align:start position:0% +try to define this with the area below + + + align:start position:0% +try to define this with the area below +the graph. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% + + + + align:start position:0% + +So again we have we have a function f + + align:start position:0% +So again we have we have a function f + + + align:start position:0% +So again we have we have a function f +from a to b + + align:start position:0% +from a to b + + + align:start position:0% +from a to b +into r. We assume that this is so uh + + align:start position:0% +into r. We assume that this is so uh + + + align:start position:0% +into r. We assume that this is so uh +that is bounded. + + align:start position:0% + + + + align:start position:0% + +We have P here is a partition + + align:start position:0% + + + + align:start position:0% + +of of this interval here. + + align:start position:0% + + + + align:start position:0% + +Then we defined a upper and a lower sum. + + align:start position:0% +Then we defined a upper and a lower sum. + + + align:start position:0% +Then we defined a upper and a lower sum. +Then we define + + align:start position:0% + + + + align:start position:0% + +upper + + align:start position:0% +upper + + + align:start position:0% +upper +and lower sums. + + align:start position:0% + + + + align:start position:0% + +as follows + + align:start position:0% +as follows + + + align:start position:0% +as follows +right so again you have a given function + + align:start position:0% +right so again you have a given function + + + align:start position:0% +right so again you have a given function +that is bounded and you have a partition + + align:start position:0% +that is bounded and you have a partition + + + align:start position:0% +that is bounded and you have a partition +and so we define upper and lower sums + + align:start position:0% +and so we define upper and lower sums + + + align:start position:0% +and so we define upper and lower sums +and the upper and lower sum I will + + align:start position:0% +and the upper and lower sum I will + + + align:start position:0% +and the upper and lower sum I will +denote like this it depends on the + + align:start position:0% +denote like this it depends on the + + + align:start position:0% +denote like this it depends on the +function of course and then on the + + align:start position:0% +function of course and then on the + + + align:start position:0% +function of course and then on the +partition that's a upper sum and the + + align:start position:0% +partition that's a upper sum and the + + + align:start position:0% +partition that's a upper sum and the +lower sum similar I would denote like + + align:start position:0% +lower sum similar I would denote like + + + align:start position:0% +lower sum similar I would denote like +this + + align:start position:0% + + + + align:start position:0% + +and so how are these defined? + + align:start position:0% + + + + align:start position:0% + +So they are defined as follow + + align:start position:0% + + + + align:start position:0% + +that you have here you have your + + align:start position:0% +that you have here you have your + + + align:start position:0% +that you have here you have your +interval from a to b. + + align:start position:0% +interval from a to b. + + + align:start position:0% +interval from a to b. +Then you have this here is x0 here I + + align:start position:0% +Then you have this here is x0 here I + + + align:start position:0% +Then you have this here is x0 here I +have x1 and here I have maybe x2 and + + align:start position:0% +have x1 and here I have maybe x2 and + + + align:start position:0% +have x1 and here I have maybe x2 and +then this thing here is then x3. + + align:start position:0% + + + + align:start position:0% + +So I take uh I look at one of these + + align:start position:0% +So I take uh I look at one of these + + + align:start position:0% +So I take uh I look at one of these +intervals + + align:start position:0% +intervals + + + align:start position:0% +intervals +or it could be this one here. that's + + align:start position:0% +or it could be this one here. that's + + + align:start position:0% +or it could be this one here. that's +between in this case it would be between + + align:start position:0% +between in this case it would be between + + + align:start position:0% +between in this case it would be between +uh x1 and x2 + + align:start position:0% +uh x1 and x2 + + + align:start position:0% +uh x1 and x2 +and I would look at the function in this + + align:start position:0% +and I would look at the function in this + + + align:start position:0% +and I would look at the function in this +interval here and I would so the + + align:start position:0% +interval here and I would so the + + + align:start position:0% +interval here and I would so the +contribution from this here would be + + align:start position:0% +contribution from this here would be + + + align:start position:0% +contribution from this here would be +that I would take so for the upper for + + align:start position:0% +that I would take so for the upper for + + + align:start position:0% +that I would take so for the upper for +the upper + + align:start position:0% +the upper + + + align:start position:0% +the upper +sum + + align:start position:0% +sum + + + align:start position:0% +sum +with respect to this partition the one + + align:start position:0% +with respect to this partition the one + + + align:start position:0% +with respect to this partition the one +that comes from this sub interval here + + align:start position:0% +that comes from this sub interval here + + + align:start position:0% +that comes from this sub interval here +would be um would be + + align:start position:0% +would be um would be + + + align:start position:0% +would be um would be +uh the soup + + align:start position:0% +uh the soup + + + align:start position:0% +uh the soup +of f on this sub interval here. + + align:start position:0% + + + + align:start position:0% + +So the soup of the function + + align:start position:0% +So the soup of the function + + + align:start position:0% +So the soup of the function +times the length of the interval + + align:start position:0% + + + + align:start position:0% + +like that. So this would be the value + + align:start position:0% +like that. So this would be the value + + + align:start position:0% +like that. So this would be the value +that in the upper that would come uh in + + align:start position:0% +that in the upper that would come uh in + + + align:start position:0% +that in the upper that would come uh in +a minute I'll write it out more more + + align:start position:0% +a minute I'll write it out more more + + + align:start position:0% +a minute I'll write it out more more +clearly but this would be what is coming + + align:start position:0% +clearly but this would be what is coming + + + align:start position:0% +clearly but this would be what is coming +from here and likewise + + align:start position:0% +from here and likewise + + + align:start position:0% +from here and likewise +uh for the lower one + + align:start position:0% +uh for the lower one + + + align:start position:0% +uh for the lower one +um the contribution from this little + + align:start position:0% +um the contribution from this little + + + align:start position:0% +um the contribution from this little +interval here would be the in of f + + align:start position:0% + + + + align:start position:0% + +and then times and The idea right is + + align:start position:0% +and then times and The idea right is + + + align:start position:0% +and then times and The idea right is +okay. So that would be the contribution. + + align:start position:0% +okay. So that would be the contribution. + + + align:start position:0% +okay. So that would be the contribution. +Um the idea of course is that you have + + align:start position:0% + + + + align:start position:0% + +but the only thing we knew was this with + + align:start position:0% +but the only thing we knew was this with + + + align:start position:0% +but the only thing we knew was this with +the area of a right angle. + + align:start position:0% +the area of a right angle. + + + align:start position:0% +the area of a right angle. +Right? + + align:start position:0% +Right? + + + align:start position:0% +Right? +And so you have this function here and + + align:start position:0% +And so you have this function here and + + + align:start position:0% +And so you have this function here and +you have some little interval here + + align:start position:0% +you have some little interval here + + + align:start position:0% +you have some little interval here +between x i and x i - uh sorry x i - one + + align:start position:0% +between x i and x i - uh sorry x i - one + + + align:start position:0% +between x i and x i - uh sorry x i - one +and x i right + + align:start position:0% +and x i right + + + align:start position:0% +and x i right +and you're focusing on this little + + align:start position:0% +and you're focusing on this little + + + align:start position:0% +and you're focusing on this little +interval here + + align:start position:0% +interval here + + + align:start position:0% +interval here +and you're looking at the function the + + align:start position:0% +and you're looking at the function the + + + align:start position:0% +and you're looking at the function the +function was bounded so there is a soup + + align:start position:0% +function was bounded so there is a soup + + + align:start position:0% +function was bounded so there is a soup +on this and you try to look at the + + align:start position:0% +on this and you try to look at the + + + align:start position:0% +on this and you try to look at the +smallest red angle angle that kind of + + align:start position:0% +smallest red angle angle that kind of + + + align:start position:0% +smallest red angle angle that kind of +have the graph that fits where the graph + + align:start position:0% +have the graph that fits where the graph + + + align:start position:0% +have the graph that fits where the graph +fits inside that right and then you're + + align:start position:0% +fits inside that right and then you're + + + align:start position:0% +fits inside that right and then you're +looking at so this this is the + + align:start position:0% +looking at so this this is the + + + align:start position:0% +looking at so this this is the +contribution + + align:start position:0% +contribution + + + align:start position:0% +contribution +from this little interval + + align:start position:0% +from this little interval + + + align:start position:0% +from this little interval +to P to to the upper sum and then you + + align:start position:0% +to P to to the upper sum and then you + + + align:start position:0% +to P to to the upper sum and then you +have right that you're looking at the + + align:start position:0% +have right that you're looking at the + + + align:start position:0% +have right that you're looking at the +largest right angle like this that fits + + align:start position:0% +largest right angle like this that fits + + + align:start position:0% +largest right angle like this that fits +under the graph and that's then + + align:start position:0% +under the graph and that's then + + + align:start position:0% +under the graph and that's then +contribution to the lower one. + + align:start position:0% +contribution to the lower one. + + + align:start position:0% +contribution to the lower one. +Right? And the idea is that if the + + align:start position:0% +Right? And the idea is that if the + + + align:start position:0% +Right? And the idea is that if the +function is reasonable, if you're + + align:start position:0% +function is reasonable, if you're + + + align:start position:0% +function is reasonable, if you're +looking at finer and finer partition, + + align:start position:0% +looking at finer and finer partition, + + + align:start position:0% +looking at finer and finer partition, +then you should you should certainly get + + align:start position:0% +then you should you should certainly get + + + align:start position:0% +then you should you should certainly get +a better a better approximation to the + + align:start position:0% +a better a better approximation to the + + + align:start position:0% +a better a better approximation to the +area below the graph, right? I mean, and + + align:start position:0% +area below the graph, right? I mean, and + + + align:start position:0% +area below the graph, right? I mean, and +and and if the function is reasonable, + + align:start position:0% +and and if the function is reasonable, + + + align:start position:0% +and and if the function is reasonable, +these two Okay, so now what is then the + + align:start position:0% +these two Okay, so now what is then the + + + align:start position:0% +these two Okay, so now what is then the +uh let me just define this. + + align:start position:0% +uh let me just define this. + + + align:start position:0% +uh let me just define this. +So this thing here + + align:start position:0% +So this thing here + + + align:start position:0% +So this thing here +it would be convenient to to the length + + align:start position:0% +it would be convenient to to the length + + + align:start position:0% +it would be convenient to to the length +of this interval to denote it by by + + align:start position:0% +of this interval to denote it by by + + + align:start position:0% +of this interval to denote it by by +this. So this is x i x i minus one. This + + align:start position:0% +this. So this is x i x i minus one. This + + + align:start position:0% +this. So this is x i x i minus one. This +just the length of that interval. + + align:start position:0% +just the length of that interval. + + + align:start position:0% +just the length of that interval. +Okay. And so now written out this thing + + align:start position:0% +Okay. And so now written out this thing + + + align:start position:0% +Okay. And so now written out this thing +and okay let me make one other notation. + + align:start position:0% +and okay let me make one other notation. + + + align:start position:0% +and okay let me make one other notation. +MI is the soup of f on x i minus one x i + + align:start position:0% +MI is the soup of f on x i minus one x i + + + align:start position:0% +MI is the soup of f on x i minus one x i +that's m capital mi and little mi is + + align:start position:0% +that's m capital mi and little mi is + + + align:start position:0% +that's m capital mi and little mi is +then the in on the same interval + + align:start position:0% + + + + align:start position:0% + +like that. And so the upper sum + + align:start position:0% +like that. And so the upper sum + + + align:start position:0% +like that. And so the upper sum +for this partition this is the sum from + + align:start position:0% +for this partition this is the sum from + + + align:start position:0% +for this partition this is the sum from +i = uh one to k + + align:start position:0% +i = uh one to k + + + align:start position:0% +i = uh one to k +of m i * delta xi. + + align:start position:0% +of m i * delta xi. + + + align:start position:0% +of m i * delta xi. +That's the upper sum. And the lower sum + + align:start position:0% +That's the upper sum. And the lower sum + + + align:start position:0% +That's the upper sum. And the lower sum +is then the sum + + align:start position:0% +is then the sum + + + align:start position:0% +is then the sum +from i = 1 to k of mi delta xi. + + align:start position:0% +from i = 1 to k of mi delta xi. + + + align:start position:0% +from i = 1 to k of mi delta xi. +Okay. So that's the upper and the lower + + align:start position:0% +Okay. So that's the upper and the lower + + + align:start position:0% +Okay. So that's the upper and the lower +sum. Okay. The first thing you observe + + align:start position:0% +sum. Okay. The first thing you observe + + + align:start position:0% +sum. Okay. The first thing you observe +is the first thing you observe is is a + + align:start position:0% +is the first thing you observe is is a + + + align:start position:0% +is the first thing you observe is is a +trivial fact + + align:start position:0% +trivial fact + + + align:start position:0% +trivial fact +and it's you know that really should be + + align:start position:0% +and it's you know that really should be + + + align:start position:0% +and it's you know that really should be +the case because one is like what fits + + align:start position:0% +the case because one is like what fits + + + align:start position:0% +the case because one is like what fits +inside the graph uh below the graph the + + align:start position:0% +inside the graph uh below the graph the + + + align:start position:0% +inside the graph uh below the graph the +other is you know where the graph fits + + align:start position:0% +other is you know where the graph fits + + + align:start position:0% +other is you know where the graph fits +below the right angle. So you clearly + + align:start position:0% +below the right angle. So you clearly + + + align:start position:0% +below the right angle. So you clearly +have just be and this is just because + + align:start position:0% +have just be and this is just because + + + align:start position:0% +have just be and this is just because +this number here is the in this is the + + align:start position:0% +this number here is the in this is the + + + align:start position:0% +this number here is the in this is the +soup on the same interval. So you + + align:start position:0% +soup on the same interval. So you + + + align:start position:0% +soup on the same interval. So you +clearly have + + align:start position:0% +clearly have + + + align:start position:0% +clearly have +that uh L F + + align:start position:0% +that uh L F + + + align:start position:0% +that uh L F +is less or equal to U FP. Right? So this + + align:start position:0% +is less or equal to U FP. Right? So this + + + align:start position:0% +is less or equal to U FP. Right? So this +is + + align:start position:0% + + + + align:start position:0% + +so this is clear. Right? + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +Let's look at uh + + align:start position:0% +Let's look at uh + + + align:start position:0% +Let's look at uh +let's look at an a couple of examples. + + align:start position:0% + + + + align:start position:0% + +So just to make sure that this is + + align:start position:0% +So just to make sure that this is + + + align:start position:0% +So just to make sure that this is +totally clear + + align:start position:0% +totally clear + + + align:start position:0% +totally clear +uh let me look at a couple example. + + align:start position:0% + + + + align:start position:0% + +So uh + + align:start position:0% +So uh + + + align:start position:0% +So uh +the um + + align:start position:0% + + + + align:start position:0% + +the first example is so I take a + + align:start position:0% +the first example is so I take a + + + align:start position:0% +the first example is so I take a +function + + align:start position:0% +function + + + align:start position:0% +function +f ofx = 2x^2 + 1 + + align:start position:0% + + + + align:start position:0% + +and my partition and the interval here + + align:start position:0% +and my partition and the interval here + + + align:start position:0% +and my partition and the interval here +I'm going to think about this as a + + align:start position:0% +I'm going to think about this as a + + + align:start position:0% +I'm going to think about this as a +function on minus2 two + + align:start position:0% +function on minus2 two + + + align:start position:0% +function on minus2 two +to two + + align:start position:0% +to two + + + align:start position:0% +to two +into R. + + align:start position:0% +into R. + + + align:start position:0% +into R. +And my partition here + + align:start position:0% +And my partition here + + + align:start position:0% +And my partition here +is going to be min -2 -1 0 1 and two + + align:start position:0% +is going to be min -2 -1 0 1 and two + + + align:start position:0% +is going to be min -2 -1 0 1 and two +um and um right and so you have so let's + + align:start position:0% +um and um right and so you have so let's + + + align:start position:0% +um and um right and so you have so let's +see so this so this here so if I draw + + align:start position:0% +see so this so this here so if I draw + + + align:start position:0% +see so this so this here so if I draw +the function + + align:start position:0% +the function + + + align:start position:0% +the function +then this is looks like if this here is + + align:start position:0% +then this is looks like if this here is + + + align:start position:0% +then this is looks like if this here is +one + + align:start position:0% +one + + + align:start position:0% +one +uh here you have one + + align:start position:0% +uh here you have one + + + align:start position:0% +uh here you have one +then it looks sort of like this. Uh + + align:start position:0% +then it looks sort of like this. Uh + + + align:start position:0% +then it looks sort of like this. Uh +doesn't more or less like this. + + align:start position:0% +doesn't more or less like this. + + + align:start position:0% +doesn't more or less like this. +Okay. And so this means that here and + + align:start position:0% +Okay. And so this means that here and + + + align:start position:0% +Okay. And so this means that here and +here you have two + + align:start position:0% +here you have two + + + align:start position:0% +here you have two +uh and this here is minus one + + align:start position:0% +uh and this here is minus one + + + align:start position:0% +uh and this here is minus one +um and + + align:start position:0% +um and + + + align:start position:0% +um and +um + + align:start position:0% + + + + align:start position:0% + +and uh and here you have uh minus two. + + align:start position:0% +and uh and here you have uh minus two. + + + align:start position:0% +and uh and here you have uh minus two. +So now if you're looking at so that the + + align:start position:0% +So now if you're looking at so that the + + + align:start position:0% +So now if you're looking at so that the +um right so so this means here that so + + align:start position:0% +um right so so this means here that so + + + align:start position:0% +um right so so this means here that so +this is my partition so this means that + + align:start position:0% +this is my partition so this means that + + + align:start position:0% +this is my partition so this means that +x0 is uh equal to minus2 + + align:start position:0% +x0 is uh equal to minus2 + + + align:start position:0% +x0 is uh equal to minus2 +x1 that's the next one is minus one x3 + + align:start position:0% +x1 that's the next one is minus one x3 + + + align:start position:0% +x1 that's the next one is minus one x3 +is the next one + + align:start position:0% +is the next one + + + align:start position:0% +is the next one +that's zero x4 + + align:start position:0% +that's zero x4 + + + align:start position:0% +that's zero x4 +is uh one and x5 y is two, right? And so + + align:start position:0% +is uh one and x5 y is two, right? And so + + + align:start position:0% +is uh one and x5 y is two, right? And so +of course all of these intervals here, + + align:start position:0% +of course all of these intervals here, + + + align:start position:0% +of course all of these intervals here, +right? They all have the same length in + + align:start position:0% +right? They all have the same length in + + + align:start position:0% +right? They all have the same length in +this case. So x i - x i -1. This was + + align:start position:0% +this case. So x i - x i -1. This was + + + align:start position:0% +this case. So x i - x i -1. This was +what we call delta x i. This here is for + + align:start position:0% +what we call delta x i. This here is for + + + align:start position:0% +what we call delta x i. This here is for +each of these is equal to one. + + align:start position:0% + + + + align:start position:0% + +And now we have that the + + align:start position:0% + + + + align:start position:0% + +and we have that the + + align:start position:0% +and we have that the + + + align:start position:0% +and we have that the +when you're looking between minus2 and + + align:start position:0% +when you're looking between minus2 and + + + align:start position:0% +when you're looking between minus2 and +two and sorry minus2 and minus one. So + + align:start position:0% +two and sorry minus2 and minus one. So + + + align:start position:0% +two and sorry minus2 and minus one. So +on this interval here + + align:start position:0% +on this interval here + + + align:start position:0% +on this interval here +um the function is the function on this + + align:start position:0% +um the function is the function on this + + + align:start position:0% +um the function is the function on this +interval here is decreasing. So the + + align:start position:0% +interval here is decreasing. So the + + + align:start position:0% +interval here is decreasing. So the +largest value is achieved at this point + + align:start position:0% +largest value is achieved at this point + + + align:start position:0% +largest value is achieved at this point +here. Right? Uh so uh m + + align:start position:0% + + + + align:start position:0% + +M1 this is the same as a soup of f + + align:start position:0% +M1 this is the same as a soup of f + + + align:start position:0% +M1 this is the same as a soup of f +between uh x0 + + align:start position:0% +between uh x0 + + + align:start position:0% +between uh x0 +and x1. And so this is the same as the + + align:start position:0% +and x1. And so this is the same as the + + + align:start position:0% +and x1. And so this is the same as the +soup of minus2 to minus1 right of f and + + align:start position:0% +soup of minus2 to minus1 right of f and + + + align:start position:0% +soup of minus2 to minus1 right of f and +the function was decreasing so the li on + + align:start position:0% +the function was decreasing so the li on + + + align:start position:0% +the function was decreasing so the li on +this interval so the largest value is + + align:start position:0% +this interval so the largest value is + + + align:start position:0% +this interval so the largest value is +achieved here and that's five + + align:start position:0% +achieved here and that's five + + + align:start position:0% +achieved here and that's five +right so this would be five + + align:start position:0% +right so this would be five + + + align:start position:0% +right so this would be five +and uh on the second interval here + + align:start position:0% +and uh on the second interval here + + + align:start position:0% +and uh on the second interval here +right so this is between minus1 and zero + + align:start position:0% +right so this is between minus1 and zero + + + align:start position:0% +right so this is between minus1 and zero +still decreasing So the value is the + + align:start position:0% +still decreasing So the value is the + + + align:start position:0% +still decreasing So the value is the +largest value is here where it's two. So + + align:start position:0% +largest value is here where it's two. So + + + align:start position:0% +largest value is here where it's two. So +this here is is two and m3 + + align:start position:0% +this here is is two and m3 + + + align:start position:0% +this here is is two and m3 +this is now uh between zero and one. So + + align:start position:0% +this is now uh between zero and one. So + + + align:start position:0% +this is now uh between zero and one. So +now it's increasing. So the large value + + align:start position:0% +now it's increasing. So the large value + + + align:start position:0% +now it's increasing. So the large value +is over here. So that's again two. + + align:start position:0% +is over here. So that's again two. + + + align:start position:0% +is over here. So that's again two. +And then the last one is is is again + + align:start position:0% +And then the last one is is is again + + + align:start position:0% +And then the last one is is is again +five. Right? + + align:start position:0% +five. Right? + + + align:start position:0% +five. Right? +And then likewise for the the the ones + + align:start position:0% +And then likewise for the the the ones + + + align:start position:0% +And then likewise for the the the ones +that are the info. So the first one m1 + + align:start position:0% +that are the info. So the first one m1 + + + align:start position:0% +that are the info. So the first one m1 +well the function was decreasing. So the + + align:start position:0% +well the function was decreasing. So the + + + align:start position:0% +well the function was decreasing. So the +smallest value is over at this end point + + align:start position:0% +smallest value is over at this end point + + + align:start position:0% +smallest value is over at this end point +there. The value is true. + + align:start position:0% +there. The value is true. + + + align:start position:0% +there. The value is true. +So you're getting uh this here is is + + align:start position:0% +So you're getting uh this here is is + + + align:start position:0% +So you're getting uh this here is is +two. + + align:start position:0% +two. + + + align:start position:0% +two. +And then between + + align:start position:0% +And then between + + + align:start position:0% +And then between +between minus1 and zero it's still + + align:start position:0% +between minus1 and zero it's still + + + align:start position:0% +between minus1 and zero it's still +decreasing. So there the smallest is at + + align:start position:0% +decreasing. So there the smallest is at + + + align:start position:0% +decreasing. So there the smallest is at +this point where it's one. So this is m2 + + align:start position:0% + + + + align:start position:0% + +and then m3 + + align:start position:0% +and then m3 + + + align:start position:0% +and then m3 +this is now here the function is + + align:start position:0% +this is now here the function is + + + align:start position:0% +this is now here the function is +increasing. So it's still the value + + align:start position:0% +increasing. So it's still the value + + + align:start position:0% +increasing. So it's still the value +here. So it's still one. And then the + + align:start position:0% +here. So it's still one. And then the + + + align:start position:0% +here. So it's still one. And then the +last one + + align:start position:0% +last one + + + align:start position:0% +last one +um is between one and two and there it's + + align:start position:0% +um is between one and two and there it's + + + align:start position:0% +um is between one and two and there it's +the infreom is the value here. So that's + + align:start position:0% +the infreom is the value here. So that's + + + align:start position:0% +the infreom is the value here. So that's +two right + + align:start position:0% + + + + align:start position:0% + +and so you see that in this case the + + align:start position:0% +and so you see that in this case the + + + align:start position:0% +and so you see that in this case the +upper + + align:start position:0% +upper + + + align:start position:0% +upper +for this function + + align:start position:0% +for this function + + + align:start position:0% +for this function +uh for this partition + + align:start position:0% +uh for this partition + + + align:start position:0% +uh for this partition +it's this right all of the intervals + + align:start position:0% +it's this right all of the intervals + + + align:start position:0% +it's this right all of the intervals +have length these small interval have + + align:start position:0% +have length these small interval have + + + align:start position:0% +have length these small interval have +length one so it's just the sum of these + + align:start position:0% +length one so it's just the sum of these + + + align:start position:0% +length one so it's just the sum of these +guys right so this is just equal to five + + align:start position:0% +guys right so this is just equal to five + + + align:start position:0% +guys right so this is just equal to five +if you will it's 5 * 1 that was length + + align:start position:0% +if you will it's 5 * 1 that was length + + + align:start position:0% +if you will it's 5 * 1 that was length +of the interval plus 2 * 1 + uh 2 * 1 + + + align:start position:0% +of the interval plus 2 * 1 + uh 2 * 1 + + + + align:start position:0% +of the interval plus 2 * 1 + uh 2 * 1 + +5 * 1. So in other words, you get here + + align:start position:0% +5 * 1. So in other words, you get here + + + align:start position:0% +5 * 1. So in other words, you get here +14. And for the lower ones, + + align:start position:0% +14. And for the lower ones, + + + align:start position:0% +14. And for the lower ones, +it's again this time I want rise times + + align:start position:0% +it's again this time I want rise times + + + align:start position:0% +it's again this time I want rise times +one. It's a sum of those guys and that's + + align:start position:0% +one. It's a sum of those guys and that's + + + align:start position:0% +one. It's a sum of those guys and that's +actually six, right? + + align:start position:0% +actually six, right? + + + align:start position:0% +actually six, right? +So So that's upper and lower sum. Okay. + + align:start position:0% +So So that's upper and lower sum. Okay. + + + align:start position:0% +So So that's upper and lower sum. Okay. +Now, uh and we had we had one um one + + align:start position:0% +Now, uh and we had we had one um one + + + align:start position:0% +Now, uh and we had we had one um one +observation that was a an immediate + + align:start position:0% +observation that was a an immediate + + + align:start position:0% +observation that was a an immediate +observation and that was uh this thing + + align:start position:0% +observation and that was uh this thing + + + align:start position:0% +observation and that was uh this thing +here. + + align:start position:0% +here. + + + align:start position:0% +here. +Now, + + align:start position:0% + + + + align:start position:0% + +what is useful is that you starting with + + align:start position:0% +what is useful is that you starting with + + + align:start position:0% +what is useful is that you starting with +a partition and then you you have a + + align:start position:0% +a partition and then you you have a + + + align:start position:0% +a partition and then you you have a +subartition. So the next one is so I + + align:start position:0% +subartition. So the next one is so I + + + align:start position:0% +subartition. So the next one is so I +take a function f on some interval from + + align:start position:0% +take a function f on some interval from + + + align:start position:0% +take a function f on some interval from +a to b and this function here is bounded + + align:start position:0% + + + + align:start position:0% + +and then I have p is a partition p1 say + + align:start position:0% +and then I have p is a partition p1 say + + + align:start position:0% +and then I have p is a partition p1 say +is a partition + + align:start position:0% + + + + align:start position:0% + +and then p2 + + align:start position:0% +and then p2 + + + align:start position:0% +and then p2 +is a sub partition. + + align:start position:0% + + + + align:start position:0% + +of P1. + + align:start position:0% +of P1. + + + align:start position:0% +of P1. +And now the thing that is uh useful is + + align:start position:0% +And now the thing that is uh useful is + + + align:start position:0% +And now the thing that is uh useful is +the following. + + align:start position:0% +the following. + + + align:start position:0% +the following. +[Applause] + + align:start position:0% + + + + align:start position:0% + +that. So, + + align:start position:0% +that. So, + + + align:start position:0% +that. So, +so the following claim, the following + + align:start position:0% +so the following claim, the following + + + align:start position:0% +so the following claim, the following +leham + + align:start position:0% + + + + align:start position:0% + +that if you take a sub partition then I + + align:start position:0% +that if you take a sub partition then I + + + align:start position:0% +that if you take a sub partition then I +claim that the value of the upper sum go + + align:start position:0% +claim that the value of the upper sum go + + + align:start position:0% +claim that the value of the upper sum go +down and the value of the lower go up. + + align:start position:0% +down and the value of the lower go up. + + + align:start position:0% +down and the value of the lower go up. +So this is the following. So uh so lower + + align:start position:0% +So this is the following. So uh so lower + + + align:start position:0% +So this is the following. So uh so lower +of f * p1. + + align:start position:0% +of f * p1. + + + align:start position:0% +of f * p1. +This is less or equal to the lower of f + + align:start position:0% +This is less or equal to the lower of f + + + align:start position:0% +This is less or equal to the lower of f +of p2. We already proved that this thing + + align:start position:0% +of p2. We already proved that this thing + + + align:start position:0% +of p2. We already proved that this thing +here, this one here, this this + + align:start position:0% +here, this one here, this this + + + align:start position:0% +here, this one here, this this +inequality we haven't proved yet. But + + align:start position:0% +inequality we haven't proved yet. But + + + align:start position:0% +inequality we haven't proved yet. But +this one here, we have that this is less + + align:start position:0% +this one here, we have that this is less + + + align:start position:0% +this one here, we have that this is less +than + + align:start position:0% +than + + + align:start position:0% +than +than the upper one for the same + + align:start position:0% +than the upper one for the same + + + align:start position:0% +than the upper one for the same +partition. And the second claim is that + + align:start position:0% +partition. And the second claim is that + + + align:start position:0% +partition. And the second claim is that +this here is then less than the upper + + align:start position:0% +this here is then less than the upper + + + align:start position:0% +this here is then less than the upper +one for the first. + + align:start position:0% +one for the first. + + + align:start position:0% +one for the first. +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +Now why is this the case? This is also + + align:start position:0% +Now why is this the case? This is also + + + align:start position:0% +Now why is this the case? This is also +actually a trivial statement but it's + + align:start position:0% +actually a trivial statement but it's + + + align:start position:0% +actually a trivial statement but it's +very useful statement. + + align:start position:0% +very useful statement. + + + align:start position:0% +very useful statement. +So imagine that you have your partition + + align:start position:0% +So imagine that you have your partition + + + align:start position:0% +So imagine that you have your partition +P1 here and then you have the dividing + + align:start position:0% +P1 here and then you have the dividing + + + align:start position:0% +P1 here and then you have the dividing +points I minus one + + align:start position:0% +points I minus one + + + align:start position:0% +points I minus one +and here you have I + + align:start position:0% +and here you have I + + + align:start position:0% +and here you have I +right and P2 is a sub partition. So + + align:start position:0% +right and P2 is a sub partition. So + + + align:start position:0% +right and P2 is a sub partition. So +there may be intervals like this where + + align:start position:0% +there may be intervals like this where + + + align:start position:0% +there may be intervals like this where +there are no further dividing points + + align:start position:0% +there are no further dividing points + + + align:start position:0% +there are no further dividing points +right but in that case the what you the + + align:start position:0% +right but in that case the what you the + + + align:start position:0% +right but in that case the what you the +contribution that for the lower and + + align:start position:0% +contribution that for the lower and + + + align:start position:0% +contribution that for the lower and +upper is the same for the two partitions + + align:start position:0% +upper is the same for the two partitions + + + align:start position:0% +upper is the same for the two partitions +right but should there be one or more + + align:start position:0% +right but should there be one or more + + + align:start position:0% +right but should there be one or more +let's just say there's one right then + + align:start position:0% +let's just say there's one right then + + + align:start position:0% +let's just say there's one right then +for the upper one you would look at you + + align:start position:0% +for the upper one you would look at you + + + align:start position:0% +for the upper one you would look at you +would then get so you would get a a a + + align:start position:0% +would then get so you would get a a a + + + align:start position:0% +would then get so you would get a a a +new dividing point. Let's call it y. + + align:start position:0% +new dividing point. Let's call it y. + + + align:start position:0% +new dividing point. Let's call it y. +And then you would get for the new one, + + align:start position:0% +And then you would get for the new one, + + + align:start position:0% +And then you would get for the new one, +you would have you would look at the + + align:start position:0% +you would have you would look at the + + + align:start position:0% +you would have you would look at the +soup here on this interval here, right? + + align:start position:0% +soup here on this interval here, right? + + + align:start position:0% +soup here on this interval here, right? +But the soup on this interval here of + + align:start position:0% +But the soup on this interval here of + + + align:start position:0% +But the soup on this interval here of +the function is less than the soup on + + align:start position:0% +the function is less than the soup on + + + align:start position:0% +the function is less than the soup on +the larger interval. So you would get a + + align:start position:0% +the larger interval. So you would get a + + + align:start position:0% +the larger interval. So you would get a +soup of f on the interval from i -1 to y + + align:start position:0% +soup of f on the interval from i -1 to y + + + align:start position:0% +soup of f on the interval from i -1 to y +of f + + align:start position:0% +of f + + + align:start position:0% +of f +you get that and then you would get + + align:start position:0% +you get that and then you would get + + + align:start position:0% +you get that and then you would get +times the length of the interval that's + + align:start position:0% +times the length of the interval that's + + + align:start position:0% +times the length of the interval that's +y - x i -1 + + align:start position:0% +y - x i -1 + + + align:start position:0% +y - x i -1 +and then you would get a second soup but + + align:start position:0% +and then you would get a second soup but + + + align:start position:0% +and then you would get a second soup but +this is now from from y to x I of f and + + align:start position:0% +this is now from from y to x I of f and + + + align:start position:0% +this is now from from y to x I of f and +then you would have multiple by the + + align:start position:0% +then you would have multiple by the + + + align:start position:0% +then you would have multiple by the +length of this interval. So this is this + + align:start position:0% +length of this interval. So this is this + + + align:start position:0% +length of this interval. So this is this +here is then from x i to y. Okay. + + align:start position:0% +here is then from x i to y. Okay. + + + align:start position:0% +here is then from x i to y. Okay. +So this is this is what you get from the + + align:start position:0% +So this is this is what you get from the + + + align:start position:0% +So this is this is what you get from the +new petition. the contribution from the + + align:start position:0% +new petition. the contribution from the + + + align:start position:0% +new petition. the contribution from the +from the second + + align:start position:0% +from the second + + + align:start position:0% +from the second +from the this is what this is the + + align:start position:0% +from the this is what this is the + + + align:start position:0% +from the this is what this is the +contribution that you get from the upper + + align:start position:0% +contribution that you get from the upper + + + align:start position:0% +contribution that you get from the upper +sum for this partition P2 from this part + + align:start position:0% +sum for this partition P2 from this part + + + align:start position:0% +sum for this partition P2 from this part +right but now you see that this thing + + align:start position:0% +right but now you see that this thing + + + align:start position:0% +right but now you see that this thing +here the soup over this little interval + + align:start position:0% +here the soup over this little interval + + + align:start position:0% +here the soup over this little interval +well that of course is less than the + + align:start position:0% +well that of course is less than the + + + align:start position:0% +well that of course is less than the +soup over the larger interval so This is + + align:start position:0% +soup over the larger interval so This is + + + align:start position:0% +soup over the larger interval so This is +less than m i and I just keep this one + + align:start position:0% +less than m i and I just keep this one + + + align:start position:0% +less than m i and I just keep this one +here + + align:start position:0% +here + + + align:start position:0% +here +and this one here is also a sub interval + + align:start position:0% +and this one here is also a sub interval + + + align:start position:0% +and this one here is also a sub interval +of this larger interval. So this is less + + align:start position:0% +of this larger interval. So this is less + + + align:start position:0% +of this larger interval. So this is less +than m i again time x i - x y. + + align:start position:0% +than m i again time x i - x y. + + + align:start position:0% +than m i again time x i - x y. +But now you can factor out the mi. So + + align:start position:0% +But now you can factor out the mi. So + + + align:start position:0% +But now you can factor out the mi. So +you're getting MI and you're getting the + + align:start position:0% +you're getting MI and you're getting the + + + align:start position:0% +you're getting MI and you're getting the +sum of these two Y - X I - one + + + align:start position:0% +sum of these two Y - X I - one + + + + align:start position:0% +sum of these two Y - X I - one + +uh X I - Y. And so you see that this + + align:start position:0% +uh X I - Y. And so you see that this + + + align:start position:0% +uh X I - Y. And so you see that this +here is exactly MI * X I - X I - one. + + align:start position:0% +here is exactly MI * X I - X I - one. + + + align:start position:0% +here is exactly MI * X I - X I - one. +Right? + + align:start position:0% +Right? + + + align:start position:0% +Right? +And so you see that the + + align:start position:0% +And so you see that the + + + align:start position:0% +And so you see that the +contribution that we get here to the + + align:start position:0% +contribution that we get here to the + + + align:start position:0% +contribution that we get here to the +upper sum from this part here + + align:start position:0% +upper sum from this part here + + + align:start position:0% +upper sum from this part here +that was this and this those two things + + align:start position:0% +that was this and this those two things + + + align:start position:0% +that was this and this those two things +this is less than the contribution we + + align:start position:0% +this is less than the contribution we + + + align:start position:0% +this is less than the contribution we +get from the upper sum from the first + + align:start position:0% +get from the upper sum from the first + + + align:start position:0% +get from the upper sum from the first +partition. Right? And so this prove this + + align:start position:0% +partition. Right? And so this prove this + + + align:start position:0% +partition. Right? And so this prove this +proves this inequality here + + align:start position:0% +proves this inequality here + + + align:start position:0% +proves this inequality here +and this inequality is just similar. + + align:start position:0% +and this inequality is just similar. + + + align:start position:0% +and this inequality is just similar. +It's just with the instead of the soups. + + align:start position:0% +It's just with the instead of the soups. + + + align:start position:0% +It's just with the instead of the soups. +Okay. So this is this is a this is like + + align:start position:0% +Okay. So this is this is a this is like + + + align:start position:0% +Okay. So this is this is a this is like +a key point. It's a you know each of + + align:start position:0% +a key point. It's a you know each of + + + align:start position:0% +a key point. It's a you know each of +these steps is like completely trivial. + + align:start position:0% +these steps is like completely trivial. + + + align:start position:0% +these steps is like completely trivial. +Uh but together it it actually means + + align:start position:0% +Uh but together it it actually means + + + align:start position:0% +Uh but together it it actually means +that you can really define something + + align:start position:0% +that you can really define something + + + align:start position:0% +that you can really define something +non-trivial. + + align:start position:0% +non-trivial. + + + align:start position:0% +non-trivial. +Okay. So now um and this may seem + + align:start position:0% +Okay. So now um and this may seem + + + align:start position:0% +Okay. So now um and this may seem +cheating. Now we uh well first of all we + + align:start position:0% +cheating. Now we uh well first of all we + + + align:start position:0% +cheating. Now we uh well first of all we +define the upper and lower integrals. + + align:start position:0% +define the upper and lower integrals. + + + align:start position:0% +define the upper and lower integrals. +So we have upper and lower sum and now + + align:start position:0% +So we have upper and lower sum and now + + + align:start position:0% +So we have upper and lower sum and now +we define the upper and lower intervals. + + align:start position:0% + + + + align:start position:0% + +So our + + align:start position:0% + + + + align:start position:0% + +and lower instruments. + + align:start position:0% + + + + align:start position:0% + +Okay. Um so the upper lower integral so + + align:start position:0% +Okay. Um so the upper lower integral so + + + align:start position:0% +Okay. Um so the upper lower integral so +the upper here is denoted like this. + + align:start position:0% +the upper here is denoted like this. + + + align:start position:0% +the upper here is denoted like this. +We take a bar over this and this is the + + align:start position:0% +We take a bar over this and this is the + + + align:start position:0% +We take a bar over this and this is the +upper lower integral. So this is the + + align:start position:0% +upper lower integral. So this is the + + + align:start position:0% +upper lower integral. So this is the +integral. This is the function. And then + + align:start position:0% +integral. This is the function. And then + + + align:start position:0% +integral. This is the function. And then +you write this. + + align:start position:0% +you write this. + + + align:start position:0% +you write this. +And so this is simply defined to be the + + align:start position:0% +And so this is simply defined to be the + + + align:start position:0% +And so this is simply defined to be the +info + + align:start position:0% +info + + + align:start position:0% +info +over all partitions + + align:start position:0% +over all partitions + + + align:start position:0% +over all partitions +of the upper integral + + align:start position:0% +of the upper integral + + + align:start position:0% +of the upper integral +upper sum. Sorry. + + align:start position:0% +upper sum. Sorry. + + + align:start position:0% +upper sum. Sorry. +Right. And so remember again that if you + + align:start position:0% +Right. And so remember again that if you + + + align:start position:0% +Right. And so remember again that if you +take a partition and you refined it, if + + align:start position:0% +take a partition and you refined it, if + + + align:start position:0% +take a partition and you refined it, if +you're looking at a subartition of the + + align:start position:0% +you're looking at a subartition of the + + + align:start position:0% +you're looking at a subartition of the +given partition, then this number here + + align:start position:0% +given partition, then this number here + + + align:start position:0% +given partition, then this number here +goes down, right? I mean it may stay the + + align:start position:0% +goes down, right? I mean it may stay the + + + align:start position:0% +goes down, right? I mean it may stay the +same, but it's certainly not bigger, + + align:start position:0% +same, but it's certainly not bigger, + + + align:start position:0% +same, but it's certainly not bigger, +right? So so this is so so the idea here + + align:start position:0% +right? So so this is so so the idea here + + + align:start position:0% +right? So so this is so so the idea here +is that essentially this number here you + + align:start position:0% +is that essentially this number here you + + + align:start position:0% +is that essentially this number here you +get by looking at finer and finer + + align:start position:0% +get by looking at finer and finer + + + align:start position:0% +get by looking at finer and finer +partition, right? So idea + + align:start position:0% +partition, right? So idea + + + align:start position:0% +partition, right? So idea +is that + + align:start position:0% +is that + + + align:start position:0% +is that +uh the infirmum uh that this is that + + align:start position:0% +uh the infirmum uh that this is that + + + align:start position:0% +uh the infirmum uh that this is that +this + + align:start position:0% +this + + + align:start position:0% +this +is a limit + + align:start position:0% +is a limit + + + align:start position:0% +is a limit +over finer and final partition. + + align:start position:0% + + + + align:start position:0% + +Right? So that's the idea sort of the + + align:start position:0% +Right? So that's the idea sort of the + + + align:start position:0% +Right? So that's the idea sort of the +the but the precise statement is is is + + align:start position:0% +the but the precise statement is is is + + + align:start position:0% +the but the precise statement is is is +that it's just the info right. So this + + align:start position:0% +that it's just the info right. So this + + + align:start position:0% +that it's just the info right. So this +is the upper integral and then likewise + + align:start position:0% +is the upper integral and then likewise + + + align:start position:0% +is the upper integral and then likewise +we define the lower integral + + align:start position:0% + + + + align:start position:0% + +>> asset + + align:start position:0% +>> asset + + + align:start position:0% +>> asset +many + + align:start position:0% +many + + + align:start position:0% +many +obviously + + align:start position:0% +obviously + + + align:start position:0% +obviously +>> right there it's it's not you know but + + align:start position:0% +>> right there it's it's not you know but + + + align:start position:0% +>> right there it's it's not you know but +there is a a key assumption is that we + + align:start position:0% +there is a a key assumption is that we + + + align:start position:0% +there is a a key assumption is that we +that for each partitions there are only + + align:start position:0% +that for each partitions there are only + + + align:start position:0% +that for each partitions there are only +finitely many divisions + + align:start position:0% +finitely many divisions + + + align:start position:0% +finitely many divisions +but there's not a but it's but but there + + align:start position:0% +but there's not a but it's but but there + + + align:start position:0% +but there's not a but it's but but there +are infinite many partitions. So it's + + align:start position:0% +are infinite many partitions. So it's + + + align:start position:0% +are infinite many partitions. So it's +really and so so when I say that it's a + + align:start position:0% +really and so so when I say that it's a + + + align:start position:0% +really and so so when I say that it's a +limit over uh finer and finer partitions + + align:start position:0% +limit over uh finer and finer partitions + + + align:start position:0% +limit over uh finer and finer partitions +you should really think about that in + + align:start position:0% +you should really think about that in + + + align:start position:0% +you should really think about that in +sort of quotation mark this not very + + align:start position:0% +sort of quotation mark this not very + + + align:start position:0% +sort of quotation mark this not very +precise statements okay so but the + + align:start position:0% +precise statements okay so but the + + + align:start position:0% +precise statements okay so but the +precise statement is just that it's + + align:start position:0% +precise statement is just that it's + + + align:start position:0% +precise statement is just that it's +infome all partitions + + align:start position:0% +infome all partitions + + + align:start position:0% +infome all partitions +and so + + align:start position:0% +and so + + + align:start position:0% +and so +so + + align:start position:0% + + + + align:start position:0% + +I mean you can make that precise but + + align:start position:0% +I mean you can make that precise but + + + align:start position:0% +I mean you can make that precise but +then that require a lot of stuff uh that + + align:start position:0% +then that require a lot of stuff uh that + + + align:start position:0% +then that require a lot of stuff uh that +we don't want to do here. Uh and there's + + align:start position:0% +we don't want to do here. Uh and there's + + + align:start position:0% +we don't want to do here. Uh and there's +no reason to it because there's a + + align:start position:0% +no reason to it because there's a + + + align:start position:0% +no reason to it because there's a +perfectly reasonable way of defining it. + + align:start position:0% +perfectly reasonable way of defining it. + + + align:start position:0% +perfectly reasonable way of defining it. +And so that was the upper integral. So + + align:start position:0% +And so that was the upper integral. So + + + align:start position:0% +And so that was the upper integral. So +this is the upper integral. + + align:start position:0% + + + + align:start position:0% + +And then similarly the lower integral + + align:start position:0% + + + + align:start position:0% + +the lower integral. And there I'm just + + align:start position:0% +the lower integral. And there I'm just + + + align:start position:0% +the lower integral. And there I'm just +putting the bar below. + + align:start position:0% + + + + align:start position:0% + +And you refine it like this. + + align:start position:0% +And you refine it like this. + + + align:start position:0% +And you refine it like this. +And this is now the soup, right? Because + + align:start position:0% +And this is now the soup, right? Because + + + align:start position:0% +And this is now the soup, right? Because +remember that if you took a partition + + align:start position:0% +remember that if you took a partition + + + align:start position:0% +remember that if you took a partition +and then you take a sub partition, then + + align:start position:0% +and then you take a sub partition, then + + + align:start position:0% +and then you take a sub partition, then +this lower sum actually went up. So it's + + align:start position:0% +this lower sum actually went up. So it's + + + align:start position:0% +this lower sum actually went up. So it's +a soup of all partitions of these lower + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +Right. And so now we say that uh and + + align:start position:0% +Right. And so now we say that uh and + + + align:start position:0% +Right. And so now we say that uh and +then we say that + + align:start position:0% +then we say that + + + align:start position:0% +then we say that +so now here's the the definition. And + + align:start position:0% +so now here's the the definition. And + + + align:start position:0% +so now here's the the definition. And +again this may initially seem like kind + + align:start position:0% +again this may initially seem like kind + + + align:start position:0% +again this may initially seem like kind +of we are uh wimping out uh because but + + align:start position:0% +of we are uh wimping out uh because but + + + align:start position:0% +of we are uh wimping out uh because but +but but it but in a minute we will then + + align:start position:0% +but but it but in a minute we will then + + + align:start position:0% +but but it but in a minute we will then +determine when this is the case. So we + + align:start position:0% +determine when this is the case. So we + + + align:start position:0% +determine when this is the case. So we +define so so f here. So if you have a + + align:start position:0% +define so so f here. So if you have a + + + align:start position:0% +define so so f here. So if you have a +bounded function like this + + align:start position:0% + + + + align:start position:0% + +then we say that + + align:start position:0% + + + + align:start position:0% + +that uh f is reman integral. + + align:start position:0% +that uh f is reman integral. + + + align:start position:0% +that uh f is reman integral. +So + + align:start position:0% + + + + align:start position:0% + +if uh if the lower sum + + align:start position:0% + + + + align:start position:0% + +is equal to the upper sum. + + align:start position:0% + + + + align:start position:0% + +So if this has the case + + align:start position:0% + + + + align:start position:0% + +um and and uh and and in that case + + align:start position:0% +um and and uh and and in that case + + + align:start position:0% +um and and uh and and in that case +and then + + align:start position:0% +and then + + + align:start position:0% +and then +the reman integral + + align:start position:0% + + + + align:start position:0% + +is this this common uh so the reman is + + align:start position:0% +is this this common uh so the reman is + + + align:start position:0% +is this this common uh so the reman is +written like + + align:start position:0% + + + + align:start position:0% + +And this is just + + align:start position:0% +And this is just + + + align:start position:0% +And this is just +this this common value. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +Now, uh one thing I just want to remark + + align:start position:0% +Now, uh one thing I just want to remark + + + align:start position:0% +Now, uh one thing I just want to remark +um is + + align:start position:0% +um is + + + align:start position:0% +um is +that + + align:start position:0% +that + + + align:start position:0% +that +that we have you always have + + align:start position:0% +that we have you always have + + + align:start position:0% +that we have you always have +That's the + + align:start position:0% + + + + align:start position:0% + +so one remark is that so + + align:start position:0% +so one remark is that so + + + align:start position:0% +so one remark is that so +so note + + align:start position:0% + + + + align:start position:0% + +that so first of all we had this trivial + + align:start position:0% +that so first of all we had this trivial + + + align:start position:0% +that so first of all we had this trivial +statement that if you take a partition + + align:start position:0% +statement that if you take a partition + + + align:start position:0% +statement that if you take a partition +then the lower sum is less or equal to + + align:start position:0% +then the lower sum is less or equal to + + + align:start position:0% +then the lower sum is less or equal to +the upper sum Fine. Then we had that if + + align:start position:0% +the upper sum Fine. Then we had that if + + + align:start position:0% +the upper sum Fine. Then we had that if +you took a sub partition, if this here + + align:start position:0% +you took a sub partition, if this here + + + align:start position:0% +you took a sub partition, if this here +was a sub partition + + align:start position:0% + + + + align:start position:0% + +of P1. Then this lower sum here + + align:start position:0% +of P1. Then this lower sum here + + + align:start position:0% +of P1. Then this lower sum here +under a sub partition, the lower sum + + align:start position:0% +under a sub partition, the lower sum + + + align:start position:0% +under a sub partition, the lower sum +went up, + + align:start position:0% +went up, + + + align:start position:0% +went up, +but it's still staying below + + align:start position:0% + + + + align:start position:0% + +So you have this inequality here. Okay. + + align:start position:0% +So you have this inequality here. Okay. + + + align:start position:0% +So you have this inequality here. Okay. +Now what what is this useful form? + + align:start position:0% +Now what what is this useful form? + + + align:start position:0% +Now what what is this useful form? +So as a consequence of this we get that + + align:start position:0% +So as a consequence of this we get that + + + align:start position:0% +So as a consequence of this we get that +the you know whether or not the function + + align:start position:0% +the you know whether or not the function + + + align:start position:0% +the you know whether or not the function +is rem integral you always have that the + + align:start position:0% +is rem integral you always have that the + + + align:start position:0% +is rem integral you always have that the +lower integral here of f dx is less or + + align:start position:0% +lower integral here of f dx is less or + + + align:start position:0% +lower integral here of f dx is less or +equal to the upper integral. + + align:start position:0% + + + + align:start position:0% + +So this here is for all functions. And + + align:start position:0% +So this here is for all functions. And + + + align:start position:0% +So this here is for all functions. And +why is this the case? This is because if + + align:start position:0% +why is this the case? This is because if + + + align:start position:0% +why is this the case? This is because if +you take this here is the soup + + align:start position:0% +you take this here is the soup + + + align:start position:0% +you take this here is the soup +of these lower partitions, right? + + align:start position:0% +of these lower partitions, right? + + + align:start position:0% +of these lower partitions, right? +But if you take any given partition, + + align:start position:0% +But if you take any given partition, + + + align:start position:0% +But if you take any given partition, +then this lower thing here is less than + + align:start position:0% +then this lower thing here is less than + + + align:start position:0% +then this lower thing here is less than +than the upper one, + + align:start position:0% + + + + align:start position:0% + +right? + + align:start position:0% +right? + + + align:start position:0% +right? +And so now so now imagine that you take + + align:start position:0% +And so now so now imagine that you take + + + align:start position:0% +And so now so now imagine that you take +so if you take a lower partition + + align:start position:0% +so if you take a lower partition + + + align:start position:0% +so if you take a lower partition +right suppose sorry suppose now that you + + align:start position:0% +right suppose sorry suppose now that you + + + align:start position:0% +right suppose sorry suppose now that you +take the soup over all partitions then + + align:start position:0% +take the soup over all partitions then + + + align:start position:0% +take the soup over all partitions then +it means that there is one partition so + + align:start position:0% +it means that there is one partition so + + + align:start position:0% +it means that there is one partition so +that this value here is close to the + + align:start position:0% +that this value here is close to the + + + align:start position:0% +that this value here is close to the +soup. + + align:start position:0% +soup. + + + align:start position:0% +soup. +But uh but for this one here right you + + align:start position:0% +But uh but for this one here right you + + + align:start position:0% +But uh but for this one here right you +have this inequality here right and so + + align:start position:0% +have this inequality here right and so + + + align:start position:0% +have this inequality here right and so +in fact but in fact if you take any so + + align:start position:0% +in fact but in fact if you take any so + + + align:start position:0% +in fact but in fact if you take any so +any other partition you can think about + + align:start position:0% +any other partition you can think about + + + align:start position:0% +any other partition you can think about +maybe I'll explain this more detail next + + align:start position:0% +maybe I'll explain this more detail next + + + align:start position:0% +maybe I'll explain this more detail next +time because I only have a minute but + + align:start position:0% +time because I only have a minute but + + + align:start position:0% +time because I only have a minute but +but it basically come from this + + align:start position:0% +but it basically come from this + + + align:start position:0% +but it basically come from this +inequality here is coming from from from + + align:start position:0% +inequality here is coming from from from + + + align:start position:0% +inequality here is coming from from from +uh from this this inequality here it + + align:start position:0% +uh from this this inequality here it + + + align:start position:0% +uh from this this inequality here it +will take just a few minutes to explain + + align:start position:0% +will take just a few minutes to explain + + + align:start position:0% +will take just a few minutes to explain +it clearly. So maybe I'll just leave it + + align:start position:0% +it clearly. So maybe I'll just leave it + + + align:start position:0% +it clearly. So maybe I'll just leave it +here. But but but a key point here is + + align:start position:0% +here. But but but a key point here is + + + align:start position:0% +here. But but but a key point here is +that you have this inequality here and + + align:start position:0% +that you have this inequality here and + + + align:start position:0% +that you have this inequality here and +it comes from that + + align:start position:0% +it comes from that + + + align:start position:0% +it comes from that +and but but we return to that next time + + align:start position:0% +and but but we return to that next time + + + align:start position:0% +and but but we return to that next time +because it's to make it really clear it + + align:start position:0% +because it's to make it really clear it + + + align:start position:0% +because it's to make it really clear it +it would take a few minutes. + + align:start position:0% +it would take a few minutes. + + + align:start position:0% +it would take a few minutes. +Now the last thing I want to say in the + + align:start position:0% +Now the last thing I want to say in the + + + align:start position:0% +Now the last thing I want to say in the +is that so this so you may think that we + + align:start position:0% +is that so this so you may think that we + + + align:start position:0% +is that so this so you may think that we +sort of whimped out of saying when this + + align:start position:0% +sort of whimped out of saying when this + + + align:start position:0% +sort of whimped out of saying when this +uh right because we just define it we + + align:start position:0% +uh right because we just define it we + + + align:start position:0% +uh right because we just define it we +just say that it's reman integraable if + + align:start position:0% +just say that it's reman integraable if + + + align:start position:0% +just say that it's reman integraable if +if uh those two things are equal right + + align:start position:0% +if uh those two things are equal right + + + align:start position:0% +if uh those two things are equal right +and so but then the question of course + + align:start position:0% +and so but then the question of course + + + align:start position:0% +and so but then the question of course +become when are those two things equal + + align:start position:0% +become when are those two things equal + + + align:start position:0% +become when are those two things equal +right so that's the key question so the + + align:start position:0% +right so that's the key question so the + + + align:start position:0% +right so that's the key question so the +key question is + + align:start position:0% + + + + align:start position:0% + +when are they equal? + + align:start position:0% + + + + align:start position:0% + +And and we'll answer this next time. + + align:start position:0% +And and we'll answer this next time. + + + align:start position:0% +And and we'll answer this next time. +Um where we will show that if f is + + align:start position:0% +Um where we will show that if f is + + + align:start position:0% +Um where we will show that if f is +continuous + + align:start position:0% + + + + align:start position:0% + +then then they are equal. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +And so uh so anyways I'll return to + + align:start position:0% +And so uh so anyways I'll return to + + + align:start position:0% +And so uh so anyways I'll return to +this. I will first um um you know we + + align:start position:0% +this. I will first um um you know we + + + align:start position:0% +this. I will first um um you know we +need anyway some more information about + + align:start position:0% +need anyway some more information about + + + align:start position:0% +need anyway some more information about +this upper and lower integral and I will + + align:start position:0% +this upper and lower integral and I will + + + align:start position:0% +this upper and lower integral and I will +first show why the lower one is less or + + align:start position:0% +first show why the lower one is less or + + + align:start position:0% +first show why the lower one is less or +equal to the lower one is lesser equal + + align:start position:0% +equal to the lower one is lesser equal + + + align:start position:0% +equal to the lower one is lesser equal +to the upper one always and then we will + + align:start position:0% +to the upper one always and then we will + + + align:start position:0% +to the upper one always and then we will +talk about you know some criteria for + + align:start position:0% +talk about you know some criteria for + + + align:start position:0% +talk about you know some criteria for +when they are equal and then we will + + align:start position:0% +when they are equal and then we will + + + align:start position:0% +when they are equal and then we will +prove this for continuous functions + + align:start position:0% +prove this for continuous functions + + + align:start position:0% +prove this for continuous functions +>> is that only + + align:start position:0% +>> is that only + + + align:start position:0% +>> is that only +>> no no no it's not it's not it's Not it's + + align:start position:0% +>> no no no it's not it's not it's Not it's + + + align:start position:0% +>> no no no it's not it's not it's Not it's +um it's uh yeah it's not a total answer. + + align:start position:0% +um it's uh yeah it's not a total answer. + + + align:start position:0% +um it's uh yeah it's not a total answer. +It's it's a it's a good initial answer + + align:start position:0% +It's it's a it's a good initial answer + + + align:start position:0% +It's it's a it's a good initial answer +but there are many functions that are + + align:start position:0% +but there are many functions that are + + + align:start position:0% +but there are many functions that are +not continuous that are very worth you + + align:start position:0% +not continuous that are very worth you + + + align:start position:0% +not continuous that are very worth you +know that plays in key roles and they're + + align:start position:0% +know that plays in key roles and they're + + + align:start position:0% +know that plays in key roles and they're +still + + align:start position:0% +still + + + align:start position:0% +still +um and we will also look at an example + + align:start position:0% +um and we will also look at an example + + + align:start position:0% +um and we will also look at an example +it's in the notes but I didn't get to + + align:start position:0% +it's in the notes but I didn't get to + + + align:start position:0% +it's in the notes but I didn't get to +it. we look at an example of a function + + align:start position:0% +it. we look at an example of a function + + + align:start position:0% +it. we look at an example of a function +that is u that is not where where you + + align:start position:0% +that is u that is not where where you + + + align:start position:0% +that is u that is not where where you +don't have this equality and this is + + align:start position:0% +don't have this equality and this is + + + align:start position:0% +don't have this equality and this is +like an old \ No newline at end of file diff --git a/yI4E3ieyu9o.txt b/yI4E3ieyu9o.txt new file mode 100644 index 0000000000000000000000000000000000000000..6b021a9b36670a2009fc42c42fdf3c980899ac35 --- /dev/null +++ b/yI4E3ieyu9o.txt @@ -0,0 +1,18739 @@ +align:start position:0% + +The following content is provided under + + align:start position:0% +The following content is provided under + + + align:start position:0% +The following content is provided under +a creative common license. Your support + + align:start position:0% +a creative common license. Your support + + + align:start position:0% +a creative common license. Your support +will help MIT Open Courseware continue + + align:start position:0% +will help MIT Open Courseware continue + + + align:start position:0% +will help MIT Open Courseware continue +to offer high-quality educational + + align:start position:0% +to offer high-quality educational + + + align:start position:0% +to offer high-quality educational +resources for free. To make a donation + + align:start position:0% +resources for free. To make a donation + + + align:start position:0% +resources for free. To make a donation +or view additional materials from + + align:start position:0% +or view additional materials from + + + align:start position:0% +or view additional materials from +hundreds of MIT courses, visit MIT Open + + align:start position:0% +hundreds of MIT courses, visit MIT Open + + + align:start position:0% +hundreds of MIT courses, visit MIT Open +Courseware at ocw.mmit.edu. + + align:start position:0% + + + + align:start position:0% + +Some content in this audio is not + + align:start position:0% +Some content in this audio is not + + + align:start position:0% +Some content in this audio is not +covered under our creative common + + align:start position:0% +covered under our creative common + + + align:start position:0% +covered under our creative common +license. For more information, see the + + align:start position:0% +license. For more information, see the + + + align:start position:0% +license. For more information, see the +course materials on the MIT Open + + align:start position:0% +course materials on the MIT Open + + + align:start position:0% +course materials on the MIT Open +Courseware website + + align:start position:0% +Courseware website + + + align:start position:0% +Courseware website +>> to a uh who's going to uh uh give us a + + align:start position:0% +>> to a uh who's going to uh uh give us a + + + align:start position:0% +>> to a uh who's going to uh uh give us a +guest lecture on on art games. And uh + + align:start position:0% +guest lecture on on art games. And uh + + + align:start position:0% +guest lecture on on art games. And uh +today's reading uh the the proc reading + + align:start position:0% +today's reading uh the the proc reading + + + align:start position:0% +today's reading uh the the proc reading +is kind of like part two of a lot of + + align:start position:0% +is kind of like part two of a lot of + + + align:start position:0% +is kind of like part two of a lot of +things that uh Jason Begley talked about + + align:start position:0% +things that uh Jason Begley talked about + + + align:start position:0% +things that uh Jason Begley talked about +uh when we did simulations. So um kind + + align:start position:0% +uh when we did simulations. So um kind + + + align:start position:0% +uh when we did simulations. So um kind +if you guys remember his talk while you + + align:start position:0% +if you guys remember his talk while you + + + align:start position:0% +if you guys remember his talk while you +were reading that that that sequest and + + align:start position:0% +were reading that that that sequest and + + + align:start position:0% +were reading that that that sequest and +what that came from. Um, one thing that + + align:start position:0% +what that came from. Um, one thing that + + + align:start position:0% +what that came from. Um, one thing that +I actually forgot to address was that + + align:start position:0% +I actually forgot to address was that + + + align:start position:0% +I actually forgot to address was that +there are actually a couple of uh + + align:start position:0% +there are actually a couple of uh + + + align:start position:0% +there are actually a couple of uh +responses to that uh to that article. If + + align:start position:0% +responses to that uh to that article. If + + + align:start position:0% +responses to that uh to that article. If +you scroll all the way down to the + + align:start position:0% +you scroll all the way down to the + + + align:start position:0% +you scroll all the way down to the +bottom of the article, there's these + + align:start position:0% +bottom of the article, there's these + + + align:start position:0% +bottom of the article, there's these +responses by Arisman and Mizuki and him + + align:start position:0% +responses by Arisman and Mizuki and him + + + align:start position:0% +responses by Arisman and Mizuki and him +back to them. And uh those are kind of + + align:start position:0% +back to them. And uh those are kind of + + + align:start position:0% +back to them. And uh those are kind of +interesting uh you know because it just + + align:start position:0% +interesting uh you know because it just + + + align:start position:0% +interesting uh you know because it just +sort of carries on a conversation and + + align:start position:0% +sort of carries on a conversation and + + + align:start position:0% +sort of carries on a conversation and +people are actually just sort of turning + + align:start position:0% +people are actually just sort of turning + + + align:start position:0% +people are actually just sort of turning +his article into basically a blog post + + align:start position:0% +his article into basically a blog post + + + align:start position:0% +his article into basically a blog post +and then writing comments. um and they + + align:start position:0% +and then writing comments. um and they + + + align:start position:0% +and then writing comments. um and they +were pretty good but a lot of that was + + align:start position:0% +were pretty good but a lot of that was + + + align:start position:0% +were pretty good but a lot of that was +kind of the state of art game discussion + + align:start position:0% +kind of the state of art game discussion + + + align:start position:0% +kind of the state of art game discussion +back in 999 I think I think it's a + + align:start position:0% +back in 999 I think I think it's a + + + align:start position:0% +back in 999 I think I think it's a +pretty old article um where they were + + align:start position:0% +pretty old article um where they were + + + align:start position:0% +pretty old article um where they were +very much thinking about you know games + + align:start position:0% +very much thinking about you know games + + + align:start position:0% +very much thinking about you know games +can games have to be simulations you + + align:start position:0% +can games have to be simulations you + + + align:start position:0% +can games have to be simulations you +know games and narratives uh you know + + align:start position:0% +know games and narratives uh you know + + + align:start position:0% +know games and narratives uh you know +storytelling is like some other mediums + + align:start position:0% +storytelling is like some other mediums + + + align:start position:0% +storytelling is like some other mediums +do uh medium domain it's all about the + + align:start position:0% +do uh medium domain it's all about the + + + align:start position:0% +do uh medium domain it's all about the +simulation um and um and arguably at + + align:start position:0% +simulation um and um and arguably at + + + align:start position:0% +simulation um and um and arguably at +that time there wasn't a big discussion + + align:start position:0% +that time there wasn't a big discussion + + + align:start position:0% +that time there wasn't a big discussion +of an art games movement. There were + + align:start position:0% +of an art games movement. There were + + + align:start position:0% +of an art games movement. There were +other games movements like new games + + align:start position:0% +other games movements like new games + + + align:start position:0% +other games movements like new games +like like like new games which were + + align:start position:0% +like like like new games which were + + + align:start position:0% +like like like new games which were +really more about uh people interacting + + align:start position:0% +really more about uh people interacting + + + align:start position:0% +really more about uh people interacting +with trying to get games to where people + + align:start position:0% +with trying to get games to where people + + + align:start position:0% +with trying to get games to where people +were more cooperative, less competitive + + align:start position:0% +were more cooperative, less competitive + + + align:start position:0% +were more cooperative, less competitive +and less cut through. Um there were + + align:start position:0% +and less cut through. Um there were + + + align:start position:0% +and less cut through. Um there were +other mo there were movements about um + + align:start position:0% +other mo there were movements about um + + + align:start position:0% +other mo there were movements about um +people um there were probably + + align:start position:0% +people um there were probably + + + align:start position:0% +people um there were probably +advertising game movements and there + + align:start position:0% +advertising game movements and there + + + align:start position:0% +advertising game movements and there +were there were a lot there was a lot of + + align:start position:0% +were there were a lot there was a lot of + + + align:start position:0% +were there were a lot there was a lot of +work in people making mods of computer + + align:start position:0% +work in people making mods of computer + + + align:start position:0% +work in people making mods of computer +games that effectively made it + + align:start position:0% +games that effectively made it + + + align:start position:0% +games that effectively made it +unplayable but made really pretty images + + align:start position:0% +unplayable but made really pretty images + + + align:start position:0% +unplayable but made really pretty images +in the process. Um so that there was a + + align:start position:0% +in the process. Um so that there was a + + + align:start position:0% +in the process. Um so that there was a +Doom hack for instance where everything + + align:start position:0% +Doom hack for instance where everything + + + align:start position:0% +Doom hack for instance where everything +becomes black and white and and is + + align:start position:0% +becomes black and white and and is + + + align:start position:0% +becomes black and white and and is +striped including the monsters. It's + + align:start position:0% +striped including the monsters. It's + + + align:start position:0% +striped including the monsters. It's +like there's no way they can see what + + align:start position:0% +like there's no way they can see what + + + align:start position:0% +like there's no way they can see what +the hell's going on but they look pretty + + align:start position:0% +the hell's going on but they look pretty + + + align:start position:0% +the hell's going on but they look pretty +cool. Um, + + align:start position:0% +cool. Um, + + + align:start position:0% +cool. Um, +>> yep. + + align:start position:0% +>> yep. + + + align:start position:0% +>> yep. +>> Have you seen I think it's 96 kilobytes. + + align:start position:0% +>> Have you seen I think it's 96 kilobytes. + + + align:start position:0% +>> Have you seen I think it's 96 kilobytes. +>> There was a competition to make a full + + align:start position:0% +>> There was a competition to make a full + + + align:start position:0% +>> There was a competition to make a full +game in a really really small size. No, + + align:start position:0% +game in a really really small size. No, + + + align:start position:0% +game in a really really small size. No, +it's 4 kilobytes I think and it's a 4 + + align:start position:0% +it's 4 kilobytes I think and it's a 4 + + + align:start position:0% +it's 4 kilobytes I think and it's a 4 +kilob game in full 3D with multiple + + align:start position:0% +kilob game in full 3D with multiple + + + align:start position:0% +kilob game in full 3D with multiple +levels and they have extremely cle + + align:start position:0% +levels and they have extremely cle + + + align:start position:0% +levels and they have extremely cle +including the music and everything + + align:start position:0% +including the music and everything + + + align:start position:0% +including the music and everything +>> like Yeah. + + align:start position:0% +>> like Yeah. + + + align:start position:0% +>> like Yeah. +>> And have you ever heard of this or seen? + + align:start position:0% +>> And have you ever heard of this or seen? + + + align:start position:0% +>> And have you ever heard of this or seen? +>> There are a couple of those u and a lot + + align:start position:0% +>> There are a couple of those u and a lot + + + align:start position:0% +>> There are a couple of those u and a lot +of those come out from the demo scene. + + align:start position:0% +of those come out from the demo scene. + + + align:start position:0% +of those come out from the demo scene. +Uh the demo scene uh which I will put + + align:start position:0% +Uh the demo scene uh which I will put + + + align:start position:0% +Uh the demo scene uh which I will put +off to some other + + align:start position:0% +off to some other + + + align:start position:0% +off to some other +>> very artsy too. It's like very + + align:start position:0% +>> very artsy too. It's like very + + + align:start position:0% +>> very artsy too. It's like very +>> Yeah. It it it's kind of this weird + + align:start position:0% +>> Yeah. It it it's kind of this weird + + + align:start position:0% +>> Yeah. It it it's kind of this weird +thing of like computer hacking, really + + align:start position:0% +thing of like computer hacking, really + + + align:start position:0% +thing of like computer hacking, really +really fast and really really compact + + align:start position:0% +really fast and really really compact + + + align:start position:0% +really fast and really really compact +coding and visual aesthetics and music. + + align:start position:0% +coding and visual aesthetics and music. + + + align:start position:0% +coding and visual aesthetics and music. +Uh which you know it's more of like a + + align:start position:0% +Uh which you know it's more of like a + + + align:start position:0% +Uh which you know it's more of like a +digital music video. Um only there was + + align:start position:0% +digital music video. Um only there was + + + align:start position:0% +digital music video. Um only there was +some people who added a mouse control + + align:start position:0% +some people who added a mouse control + + + align:start position:0% +some people who added a mouse control +and gameplay into it and made these tiny + + align:start position:0% +and gameplay into it and made these tiny + + + align:start position:0% +and gameplay into it and made these tiny +little games. Um but uh that that was + + align:start position:0% +little games. Um but uh that that was + + + align:start position:0% +little games. Um but uh that that was +pretty much art that that's very + + align:start position:0% +pretty much art that that's very + + + align:start position:0% +pretty much art that that's very +different from the art game scene that + + align:start position:0% +different from the art game scene that + + + align:start position:0% +different from the art game scene that +we have today or at least what is + + align:start position:0% +we have today or at least what is + + + align:start position:0% +we have today or at least what is +commonly described as our games. So, uh, + + align:start position:0% +commonly described as our games. So, uh, + + + align:start position:0% +commonly described as our games. So, uh, +I, um, I'd like to aid to talk about + + align:start position:0% +I, um, I'd like to aid to talk about + + + align:start position:0% +I, um, I'd like to aid to talk about +kind of what happened from, um, since + + align:start position:0% +kind of what happened from, um, since + + + align:start position:0% +kind of what happened from, um, since +then, since, uh, since 99. + + align:start position:0% +then, since, uh, since 99. + + + align:start position:0% +then, since, uh, since 99. +>> Yeah. + + align:start position:0% +>> Yeah. + + + align:start position:0% +>> Yeah. +>> Yeah. So, hi guys. I'm I'm, uh, Abe. Uh, + + align:start position:0% +>> Yeah. So, hi guys. I'm I'm, uh, Abe. Uh, + + + align:start position:0% +>> Yeah. So, hi guys. I'm I'm, uh, Abe. Uh, +I work here at the lab. I've played a + + align:start position:0% +I work here at the lab. I've played a + + + align:start position:0% +I work here at the lab. I've played a +bunch of your games. I've met a bunch of + + align:start position:0% +bunch of your games. I've met a bunch of + + + align:start position:0% +bunch of your games. I've met a bunch of +you. Um, so it's it's nice to be here. + + align:start position:0% +you. Um, so it's it's nice to be here. + + + align:start position:0% +you. Um, so it's it's nice to be here. +Philip uh, asked me to come in to talk + + align:start position:0% +Philip uh, asked me to come in to talk + + + align:start position:0% +Philip uh, asked me to come in to talk +about, uh, quote unquote art games. Uh I + + align:start position:0% +about, uh, quote unquote art games. Uh I + + + align:start position:0% +about, uh, quote unquote art games. Uh I +think largely because it's a kind of um + + align:start position:0% +think largely because it's a kind of um + + + align:start position:0% +think largely because it's a kind of um +uh I'll say sector of kind of game + + align:start position:0% +uh I'll say sector of kind of game + + + align:start position:0% +uh I'll say sector of kind of game +development that uh my work at Gambit + + align:start position:0% +development that uh my work at Gambit + + + align:start position:0% +development that uh my work at Gambit +tends to intersect with um especially + + align:start position:0% +tends to intersect with um especially + + + align:start position:0% +tends to intersect with um especially +recently. Um and I think too that it's + + align:start position:0% +recently. Um and I think too that it's + + + align:start position:0% +recently. Um and I think too that it's +um + + align:start position:0% +um + + + align:start position:0% +um +>> sorry + + align:start position:0% + + + + align:start position:0% + +I don't know. I think too that it's um I + + align:start position:0% +I don't know. I think too that it's um I + + + align:start position:0% +I don't know. I think too that it's um I +think too that it's a uh it's kind of a + + align:start position:0% +think too that it's a uh it's kind of a + + + align:start position:0% +think too that it's a uh it's kind of a +sector that's that's a little bit + + align:start position:0% +sector that's that's a little bit + + + align:start position:0% +sector that's that's a little bit +confused and um and possibly confusing + + align:start position:0% +confused and um and possibly confusing + + + align:start position:0% +confused and um and possibly confusing +too. And so um just to give you guys a + + align:start position:0% +too. And so um just to give you guys a + + + align:start position:0% +too. And so um just to give you guys a +sense um you know when he asked me about + + align:start position:0% +sense um you know when he asked me about + + + align:start position:0% +sense um you know when he asked me about +this it actually made me it kind of made + + align:start position:0% +this it actually made me it kind of made + + + align:start position:0% +this it actually made me it kind of made +me think cuz I was like oh yeah cool. + + align:start position:0% +me think cuz I was like oh yeah cool. + + + align:start position:0% +me think cuz I was like oh yeah cool. +I'll talk about like this art games + + align:start position:0% +I'll talk about like this art games + + + align:start position:0% +I'll talk about like this art games +movement or whatever but you know then + + align:start position:0% +movement or whatever but you know then + + + align:start position:0% +movement or whatever but you know then +of course um wait I'm locked into some + + align:start position:0% +of course um wait I'm locked into some + + + align:start position:0% +of course um wait I'm locked into some +kind of weird mode right now. + + align:start position:0% +kind of weird mode right now. + + + align:start position:0% +kind of weird mode right now. +Sorry. Okay. Um that brings up this + + align:start position:0% +Sorry. Okay. Um that brings up this + + + align:start position:0% +Sorry. Okay. Um that brings up this +question which is which is our games + + align:start position:0% +question which is which is our games + + + align:start position:0% +question which is which is our games +art. And just to um just to kind of give + + align:start position:0% +art. And just to um just to kind of give + + + align:start position:0% +art. And just to um just to kind of give +you a a sense for how this this little + + align:start position:0% +you a a sense for how this this little + + + align:start position:0% +you a a sense for how this this little +talk thing whatever is going to go um + + align:start position:0% +talk thing whatever is going to go um + + + align:start position:0% +talk thing whatever is going to go um +I'm going to talk a little bit about + + align:start position:0% +I'm going to talk a little bit about + + + align:start position:0% +I'm going to talk a little bit about +this question um give you kind of + + align:start position:0% +this question um give you kind of + + + align:start position:0% +this question um give you kind of +examples of what people have said about + + align:start position:0% +examples of what people have said about + + + align:start position:0% +examples of what people have said about +this um and opinions that I think are + + align:start position:0% +this um and opinions that I think are + + + align:start position:0% +this um and opinions that I think are +particularly important particularly + + align:start position:0% +particularly important particularly + + + align:start position:0% +particularly important particularly +valid on this subject. Um I also after + + align:start position:0% +valid on this subject. Um I also after + + + align:start position:0% +valid on this subject. Um I also after +that want to show you some examples um + + align:start position:0% +that want to show you some examples um + + + align:start position:0% +that want to show you some examples um +some historical and then kind of moving + + align:start position:0% +some historical and then kind of moving + + + align:start position:0% +some historical and then kind of moving +forward examples. I'm actually going to + + align:start position:0% +forward examples. I'm actually going to + + + align:start position:0% +forward examples. I'm actually going to +get some of you guys to to just come up + + align:start position:0% +get some of you guys to to just come up + + + align:start position:0% +get some of you guys to to just come up +here and maybe even play some of these + + align:start position:0% +here and maybe even play some of these + + + align:start position:0% +here and maybe even play some of these +examples that I think are particularly + + align:start position:0% +examples that I think are particularly + + + align:start position:0% +examples that I think are particularly +important. And and I'd really like it if + + align:start position:0% +important. And and I'd really like it if + + + align:start position:0% +important. And and I'd really like it if +we can kind of keep this less of a uh me + + align:start position:0% +we can kind of keep this less of a uh me + + + align:start position:0% +we can kind of keep this less of a uh me +talking at you and and you engaging me + + align:start position:0% +talking at you and and you engaging me + + + align:start position:0% +talking at you and and you engaging me +as you have questions on this because I + + align:start position:0% +as you have questions on this because I + + + align:start position:0% +as you have questions on this because I +it's really like me you know blabbing at + + align:start position:0% +it's really like me you know blabbing at + + + align:start position:0% +it's really like me you know blabbing at +you as you fall asleep is is um you know + + align:start position:0% +you as you fall asleep is is um you know + + + align:start position:0% +you as you fall asleep is is um you know +maybe good for a nap but less useful for + + align:start position:0% +maybe good for a nap but less useful for + + + align:start position:0% +maybe good for a nap but less useful for +um you know getting anything out of + + align:start position:0% +um you know getting anything out of + + + align:start position:0% +um you know getting anything out of +this. Um, so we'll try to structure this + + align:start position:0% +this. Um, so we'll try to structure this + + + align:start position:0% +this. Um, so we'll try to structure this +as a conversation and and I'll I'll try + + align:start position:0% +as a conversation and and I'll I'll try + + + align:start position:0% +as a conversation and and I'll I'll try +to pull back hearken back to any of my + + align:start position:0% +to pull back hearken back to any of my + + + align:start position:0% +to pull back hearken back to any of my +teacher instincts and see if I can get + + align:start position:0% +teacher instincts and see if I can get + + + align:start position:0% +teacher instincts and see if I can get +you engaged, but we'll see. Um, so our + + align:start position:0% +you engaged, but we'll see. Um, so our + + + align:start position:0% +you engaged, but we'll see. Um, so our +game's art I um I hate this question. + + align:start position:0% +game's art I um I hate this question. + + + align:start position:0% +game's art I um I hate this question. +Uh, I will start off by saying that I + + align:start position:0% +Uh, I will start off by saying that I + + + align:start position:0% +Uh, I will start off by saying that I +fundamentally and I find it abhorent and + + align:start position:0% +fundamentally and I find it abhorent and + + + align:start position:0% +fundamentally and I find it abhorent and +I hear it all the time. Um, and it's + + align:start position:0% +I hear it all the time. Um, and it's + + + align:start position:0% +I hear it all the time. Um, and it's +aggravating to me because I think it's + + align:start position:0% +aggravating to me because I think it's + + + align:start position:0% +aggravating to me because I think it's +it's incontrovertibly yes. Um I think + + align:start position:0% +it's incontrovertibly yes. Um I think + + + align:start position:0% +it's incontrovertibly yes. Um I think +that you can't possibly come up with any + + align:start position:0% +that you can't possibly come up with any + + + align:start position:0% +that you can't possibly come up with any +other answer other than yes, games are + + align:start position:0% +other answer other than yes, games are + + + align:start position:0% +other answer other than yes, games are +art, games have art. Yes. Yes. Yes. + + align:start position:0% +art, games have art. Yes. Yes. Yes. + + + align:start position:0% +art, games have art. Yes. Yes. Yes. +Right. But um it keeps coming up and it + + align:start position:0% +Right. But um it keeps coming up and it + + + align:start position:0% +Right. But um it keeps coming up and it +keeps kind of becoming a question. And I + + align:start position:0% +keeps kind of becoming a question. And I + + + align:start position:0% +keeps kind of becoming a question. And I +should say too that this is a um this is + + align:start position:0% +should say too that this is a um this is + + + align:start position:0% +should say too that this is a um this is +a wholly biased and uh slanted talk. + + align:start position:0% +a wholly biased and uh slanted talk. + + + align:start position:0% +a wholly biased and uh slanted talk. +This is this is my perspective on this + + align:start position:0% +This is this is my perspective on this + + + align:start position:0% +This is this is my perspective on this +and hopefully by the time you're done + + align:start position:0% +and hopefully by the time you're done + + + align:start position:0% +and hopefully by the time you're done +you'll be like wow he is absolutely + + align:start position:0% +you'll be like wow he is absolutely + + + align:start position:0% +you'll be like wow he is absolutely +right. There is no way that games could + + align:start position:0% +right. There is no way that games could + + + align:start position:0% +right. There is no way that games could +be anything but art. Um or at least they + + align:start position:0% +be anything but art. Um or at least they + + + align:start position:0% +be anything but art. Um or at least they +are art and then some. Um, so, um, this + + align:start position:0% +are art and then some. Um, so, um, this + + + align:start position:0% +are art and then some. Um, so, um, this +guy, um, who's a little hard to see + + align:start position:0% +guy, um, who's a little hard to see + + + align:start position:0% +guy, um, who's a little hard to see +right now, but he's totally blown up. + + align:start position:0% +right now, but he's totally blown up. + + + align:start position:0% +right now, but he's totally blown up. +Um, recently brought this into the for + + align:start position:0% +Um, recently brought this into the for + + + align:start position:0% +Um, recently brought this into the for +um, and that's, uh, that's Roger Eert + + align:start position:0% +um, and that's, uh, that's Roger Eert + + + align:start position:0% +um, and that's, uh, that's Roger Eert +of, uh, Eert System Eert fame, or since + + align:start position:0% +of, uh, Eert System Eert fame, or since + + + align:start position:0% +of, uh, Eert System Eert fame, or since +you guys are some of you younger than + + align:start position:0% +you guys are some of you younger than + + + align:start position:0% +you guys are some of you younger than +me, probably Eert and Roer. Um, and he + + align:start position:0% +me, probably Eert and Roer. Um, and he + + + align:start position:0% +me, probably Eert and Roer. Um, and he +had some interesting and controversial + + align:start position:0% +had some interesting and controversial + + + align:start position:0% +had some interesting and controversial +comments recently. Um, and I I pulled + + align:start position:0% +comments recently. Um, and I I pulled + + + align:start position:0% +comments recently. Um, and I I pulled +this quote. Nevertheless, I remain + + align:start position:0% +this quote. Nevertheless, I remain + + + align:start position:0% +this quote. Nevertheless, I remain +convinced that in principle, I love that + + align:start position:0% +convinced that in principle, I love that + + + align:start position:0% +convinced that in principle, I love that +he put that in uh italics. Video games + + align:start position:0% +he put that in uh italics. Video games + + + align:start position:0% +he put that in uh italics. Video games +cannot be art. Perhaps it is foolish of + + align:start position:0% +cannot be art. Perhaps it is foolish of + + + align:start position:0% +cannot be art. Perhaps it is foolish of +me to say never because never, as Rick + + align:start position:0% +me to say never because never, as Rick + + + align:start position:0% +me to say never because never, as Rick +Wakeakeman informs us, is a long, long + + align:start position:0% +Wakeakeman informs us, is a long, long + + + align:start position:0% +Wakeakeman informs us, is a long, long +time. Let me just say that no video + + align:start position:0% +time. Let me just say that no video + + + align:start position:0% +time. Let me just say that no video +gamer now living will survive long + + align:start position:0% +gamer now living will survive long + + + align:start position:0% +gamer now living will survive long +enough to experience the medium as an + + align:start position:0% +enough to experience the medium as an + + + align:start position:0% +enough to experience the medium as an +art form. Um, so apparently we should + + align:start position:0% +art form. Um, so apparently we should + + + align:start position:0% +art form. Um, so apparently we should +all be dead already, um, according to + + align:start position:0% +all be dead already, um, according to + + + align:start position:0% +all be dead already, um, according to +Eert because we wouldn't have lived long + + align:start position:0% +Eert because we wouldn't have lived long + + + align:start position:0% +Eert because we wouldn't have lived long +enough to experience the medium as an + + align:start position:0% +enough to experience the medium as an + + + align:start position:0% +enough to experience the medium as an +art form. But here's a guy who um even + + align:start position:0% +art form. But here's a guy who um even + + + align:start position:0% +art form. But here's a guy who um even +though I don't think he's a particularly + + align:start position:0% +though I don't think he's a particularly + + + align:start position:0% +though I don't think he's a particularly +good film critic, he's a popular film + + align:start position:0% +good film critic, he's a popular film + + + align:start position:0% +good film critic, he's a popular film +critic and he's kind of weighing in on a + + align:start position:0% +critic and he's kind of weighing in on a + + + align:start position:0% +critic and he's kind of weighing in on a +medium that he doesn't particularly + + align:start position:0% +medium that he doesn't particularly + + + align:start position:0% +medium that he doesn't particularly +understand. And I think it's important + + align:start position:0% +understand. And I think it's important + + + align:start position:0% +understand. And I think it's important +to look at what exactly is he doing when + + align:start position:0% +to look at what exactly is he doing when + + + align:start position:0% +to look at what exactly is he doing when +he makes this statement. And so he's in + + align:start position:0% +he makes this statement. And so he's in + + + align:start position:0% +he makes this statement. And so he's in +this kind of business of classification, + + align:start position:0% +this kind of business of classification, + + + align:start position:0% +this kind of business of classification, +right? He's in this business of saying, + + align:start position:0% +right? He's in this business of saying, + + + align:start position:0% +right? He's in this business of saying, +"All right, well, we've got this subject + + align:start position:0% +"All right, well, we've got this subject + + + align:start position:0% +"All right, well, we've got this subject +called art. What can we say falls under + + align:start position:0% +called art. What can we say falls under + + + align:start position:0% +called art. What can we say falls under +that subset and what what what does + + align:start position:0% +that subset and what what what does + + + align:start position:0% +that subset and what what what does +not?" And so, you know, he says things + + align:start position:0% +not?" And so, you know, he says things + + + align:start position:0% +not?" And so, you know, he says things +like painting, sculpture, dance, opera, + + align:start position:0% +like painting, sculpture, dance, opera, + + + align:start position:0% +like painting, sculpture, dance, opera, +literature, film um can all be + + align:start position:0% +literature, film um can all be + + + align:start position:0% +literature, film um can all be +classified as art and and that games um + + align:start position:0% +classified as art and and that games um + + + align:start position:0% +classified as art and and that games um +games are not. Um probably some other + + align:start position:0% +games are not. Um probably some other + + + align:start position:0% +games are not. Um probably some other +things. I don't know where he stands on + + align:start position:0% +things. I don't know where he stands on + + + align:start position:0% +things. I don't know where he stands on +comic books. I don't think he's written + + align:start position:0% +comic books. I don't think he's written + + + align:start position:0% +comic books. I don't think he's written +about it yet, but I'm sure he can + + align:start position:0% +about it yet, but I'm sure he can + + + align:start position:0% +about it yet, but I'm sure he can +probably I don't know where he what he + + align:start position:0% +probably I don't know where he what he + + + align:start position:0% +probably I don't know where he what he +thinks about pornography. Um although + + align:start position:0% +thinks about pornography. Um although + + + align:start position:0% +thinks about pornography. Um although +since it's in film form, maybe he does + + align:start position:0% +since it's in film form, maybe he does + + + align:start position:0% +since it's in film form, maybe he does +think it's art. It's unclear. He hasn't + + align:start position:0% +think it's art. It's unclear. He hasn't + + + align:start position:0% +think it's art. It's unclear. He hasn't +he hasn't weighed in on that yet. Um but + + align:start position:0% +he hasn't weighed in on that yet. Um but + + + align:start position:0% +he hasn't weighed in on that yet. Um but +the interesting thing about this is this + + align:start position:0% +the interesting thing about this is this + + + align:start position:0% +the interesting thing about this is this +is not this is not new, right? This is + + align:start position:0% +is not this is not new, right? This is + + + align:start position:0% +is not this is not new, right? This is +like a high culture, low culture debate + + align:start position:0% +like a high culture, low culture debate + + + align:start position:0% +like a high culture, low culture debate +that's been going on for a really long + + align:start position:0% +that's been going on for a really long + + + align:start position:0% +that's been going on for a really long +time. And I think it's particularly + + align:start position:0% +time. And I think it's particularly + + + align:start position:0% +time. And I think it's particularly +hilarious because he reviews films and + + align:start position:0% +hilarious because he reviews films and + + + align:start position:0% +hilarious because he reviews films and +films had to fight out of the low + + align:start position:0% +films had to fight out of the low + + + align:start position:0% +films had to fight out of the low +culture phenomenon to gain respect as a + + align:start position:0% +culture phenomenon to gain respect as a + + + align:start position:0% +culture phenomenon to gain respect as a +high culture medium, right? And so he's + + align:start position:0% +high culture medium, right? And so he's + + + align:start position:0% +high culture medium, right? And so he's +he's working reviewing a medium that + + align:start position:0% +he's working reviewing a medium that + + + align:start position:0% +he's working reviewing a medium that +that was once conceived as low culture, + + align:start position:0% +that was once conceived as low culture, + + + align:start position:0% +that was once conceived as low culture, +had to work really hard to be considered + + align:start position:0% +had to work really hard to be considered + + + align:start position:0% +had to work really hard to be considered +high culture. And now he's saying, + + align:start position:0% +high culture. And now he's saying, + + + align:start position:0% +high culture. And now he's saying, +"Look, my films are high culture, your + + align:start position:0% +"Look, my films are high culture, your + + + align:start position:0% +"Look, my films are high culture, your +video games are low culture." um which + + align:start position:0% +video games are low culture." um which + + + align:start position:0% +video games are low culture." um which +is totally hilarious because you know in + + align:start position:0% +is totally hilarious because you know in + + + align:start position:0% +is totally hilarious because you know in +the past 50 years um this has been + + align:start position:0% +the past 50 years um this has been + + + align:start position:0% +the past 50 years um this has been +completely collapsed by postmodernism + + align:start position:0% +completely collapsed by postmodernism + + + align:start position:0% +completely collapsed by postmodernism +right but this is a this is that's a + + align:start position:0% +right but this is a this is that's a + + + align:start position:0% +right but this is a this is that's a +whole another talk alto together right + + align:start position:0% +whole another talk alto together right + + + align:start position:0% +whole another talk alto together right +like maybe high culture and low culture + + align:start position:0% +like maybe high culture and low culture + + + align:start position:0% +like maybe high culture and low culture +don't even exist anymore um so Ebert + + align:start position:0% +don't even exist anymore um so Ebert + + + align:start position:0% +don't even exist anymore um so Ebert +brings this all back and he get + + align:start position:0% +brings this all back and he get + + + align:start position:0% +brings this all back and he get +everybody upset and a bunch of trolls + + align:start position:0% +everybody upset and a bunch of trolls + + + align:start position:0% +everybody upset and a bunch of trolls +are on his website saying really + + align:start position:0% +are on his website saying really + + + align:start position:0% +are on his website saying really +terrible things about him and about what + + align:start position:0% +terrible things about him and about what + + + align:start position:0% +terrible things about him and about what +he said but he he kind of reinvigorated + + align:start position:0% +he said but he he kind of reinvigorated + + + align:start position:0% +he said but he he kind of reinvigorated +this talk um and so a new scientist + + align:start position:0% +this talk um and so a new scientist + + + align:start position:0% +this talk um and so a new scientist +inspired by this eert controversy and + + align:start position:0% +inspired by this eert controversy and + + + align:start position:0% +inspired by this eert controversy and +looking for content um on culture lab + + align:start position:0% +looking for content um on culture lab + + + align:start position:0% +looking for content um on culture lab +asked the question can games VR and they + + align:start position:0% +asked the question can games VR and they + + + align:start position:0% +asked the question can games VR and they +sent it out to a bunch of game scholars + + align:start position:0% +sent it out to a bunch of game scholars + + + align:start position:0% +sent it out to a bunch of game scholars +saying what what is your opinion on + + align:start position:0% +saying what what is your opinion on + + + align:start position:0% +saying what what is your opinion on +this? Um and Ian Bogost is is a is a + + align:start position:0% +this? Um and Ian Bogost is is a is a + + + align:start position:0% +this? Um and Ian Bogost is is a is a +very smart guy and and said says you + + align:start position:0% +very smart guy and and said says you + + + align:start position:0% +very smart guy and and said says you +know some really interesting things. + + align:start position:0% +know some really interesting things. + + + align:start position:0% +know some really interesting things. +This is really long. I'm not going to + + align:start position:0% +This is really long. I'm not going to + + + align:start position:0% +This is really long. I'm not going to +read the whole thing but in the first + + align:start position:0% +read the whole thing but in the first + + + align:start position:0% +read the whole thing but in the first +paragraph you know he brings up things + + align:start position:0% +paragraph you know he brings up things + + + align:start position:0% +paragraph you know he brings up things +like fountain uh by Marcel Duchamp which + + align:start position:0% +like fountain uh by Marcel Duchamp which + + + align:start position:0% +like fountain uh by Marcel Duchamp which +is you know a urinal um in a museum for + + align:start position:0% +is you know a urinal um in a museum for + + + align:start position:0% +is you know a urinal um in a museum for +those of you who don't know about it. + + align:start position:0% +those of you who don't know about it. + + + align:start position:0% +those of you who don't know about it. +And that was, you know, that was a + + align:start position:0% +And that was, you know, that was a + + + align:start position:0% +And that was, you know, that was a +statement, a piece of art that he was + + align:start position:0% +statement, a piece of art that he was + + + align:start position:0% +statement, a piece of art that he was +literally trying to confront what what + + align:start position:0% +literally trying to confront what what + + + align:start position:0% +literally trying to confront what what +high culture defines as art by taking + + align:start position:0% +high culture defines as art by taking + + + align:start position:0% +high culture defines as art by taking +literally a urinal, putting it upside + + align:start position:0% +literally a urinal, putting it upside + + + align:start position:0% +literally a urinal, putting it upside +down on art and titling it fountain, + + align:start position:0% +down on art and titling it fountain, + + + align:start position:0% +down on art and titling it fountain, +upside down on a pedal and titling it + + align:start position:0% +upside down on a pedal and titling it + + + align:start position:0% +upside down on a pedal and titling it +fountain and putting it in a museum, + + align:start position:0% +fountain and putting it in a museum, + + + align:start position:0% +fountain and putting it in a museum, +which is the pinnacle of high culture, + + align:start position:0% +which is the pinnacle of high culture, + + + align:start position:0% +which is the pinnacle of high culture, +right? If you can make it in a museum, + + align:start position:0% +right? If you can make it in a museum, + + + align:start position:0% +right? If you can make it in a museum, +your art. Um, and so, you know, this is + + align:start position:0% +your art. Um, and so, you know, this is + + + align:start position:0% +your art. Um, and so, you know, this is +something that, you know, that he did. + + align:start position:0% +something that, you know, that he did. + + + align:start position:0% +something that, you know, that he did. +He he mentions Yoko Ono's performance + + align:start position:0% +He he mentions Yoko Ono's performance + + + align:start position:0% +He he mentions Yoko Ono's performance +art where, um, she's sitting in a chair + + align:start position:0% +art where, um, she's sitting in a chair + + + align:start position:0% +art where, um, she's sitting in a chair +um, and she has scissors next to her and + + align:start position:0% +um, and she has scissors next to her and + + + align:start position:0% +um, and she has scissors next to her and +the audience is invited to come uh, cut + + align:start position:0% +the audience is invited to come uh, cut + + + align:start position:0% +the audience is invited to come uh, cut +her clothes off one piece at a time. um + + align:start position:0% +her clothes off one piece at a time. um + + + align:start position:0% +her clothes off one piece at a time. um +you know a lot of this kind of stuff you + + align:start position:0% +you know a lot of this kind of stuff you + + + align:start position:0% +you know a lot of this kind of stuff you +know uh Andy Warhol pop culture + + align:start position:0% +know uh Andy Warhol pop culture + + + align:start position:0% +know uh Andy Warhol pop culture +paintings um you know Mandrean's uh kind + + align:start position:0% +paintings um you know Mandrean's uh kind + + + align:start position:0% +paintings um you know Mandrean's uh kind +of uh you know abstract paintings and + + align:start position:0% +of uh you know abstract paintings and + + + align:start position:0% +of uh you know abstract paintings and +and um you know he says a lot in that + + align:start position:0% +and um you know he says a lot in that + + + align:start position:0% +and um you know he says a lot in that +first paragraph but I think this this + + align:start position:0% +first paragraph but I think this this + + + align:start position:0% +first paragraph but I think this this +interesting part that I sort of pseudo + + align:start position:0% +interesting part that I sort of pseudo + + + align:start position:0% +interesting part that I sort of pseudo +highlighted down here is interesting um + + align:start position:0% +highlighted down here is interesting um + + + align:start position:0% +highlighted down here is interesting um +starting in the middle he says if the + + align:start position:0% +starting in the middle he says if the + + + align:start position:0% +starting in the middle he says if the +purpose of art is indeed to force us to + + align:start position:0% +purpose of art is indeed to force us to + + + align:start position:0% +purpose of art is indeed to force us to +see something we thought we understood + + align:start position:0% +see something we thought we understood + + + align:start position:0% +see something we thought we understood +in a new light perhaps the most + + align:start position:0% +in a new light perhaps the most + + + align:start position:0% +in a new light perhaps the most +fundamental move video games have made + + align:start position:0% +fundamental move video games have made + + + align:start position:0% +fundamental move video games have made +in the artistic tradition is in the very + + align:start position:0% +in the artistic tradition is in the very + + + align:start position:0% +in the artistic tradition is in the very +eliciting of the question can video + + align:start position:0% +eliciting of the question can video + + + align:start position:0% +eliciting of the question can video +games be art I I think that's really + + align:start position:0% +games be art I I think that's really + + + align:start position:0% +games be art I I think that's really +interesting, right? So, the fact that + + align:start position:0% +interesting, right? So, the fact that + + + align:start position:0% +interesting, right? So, the fact that +people are even asking this question + + align:start position:0% +people are even asking this question + + + align:start position:0% +people are even asking this question +suggests that video games are doing + + align:start position:0% +suggests that video games are doing + + + align:start position:0% +suggests that video games are doing +something that aren't we traditionally + + align:start position:0% +something that aren't we traditionally + + + align:start position:0% +something that aren't we traditionally +conceive of aren't doing. Um, and so + + align:start position:0% +conceive of aren't doing. Um, and so + + + align:start position:0% +conceive of aren't doing. Um, and so +that's, you know, that's I think a + + align:start position:0% +that's, you know, that's I think a + + + align:start position:0% +that's, you know, that's I think a +really kind of powerful statement that + + align:start position:0% +really kind of powerful statement that + + + align:start position:0% +really kind of powerful statement that +that we're even having this discussion. + + align:start position:0% +that we're even having this discussion. + + + align:start position:0% +that we're even having this discussion. +It kind of renders the question question + + align:start position:0% +It kind of renders the question question + + + align:start position:0% +It kind of renders the question question +moot in some senses, which which is, you + + align:start position:0% +moot in some senses, which which is, you + + + align:start position:0% +moot in some senses, which which is, you +know, kind of I would say classic Bosian + + align:start position:0% +know, kind of I would say classic Bosian + + + align:start position:0% +know, kind of I would say classic Bosian +um word play. Um, I think I just made + + align:start position:0% +um word play. Um, I think I just made + + + align:start position:0% +um word play. Um, I think I just made +something up called Bosian. + + align:start position:0% +something up called Bosian. + + + align:start position:0% +something up called Bosian. +tweet him about. Um, so John Sharp from + + align:start position:0% +tweet him about. Um, so John Sharp from + + + align:start position:0% +tweet him about. Um, so John Sharp from +the Savannah College of Art Design um + + align:start position:0% +the Savannah College of Art Design um + + + align:start position:0% +the Savannah College of Art Design um +has had a lot of kind of thoughts on + + align:start position:0% +has had a lot of kind of thoughts on + + + align:start position:0% +has had a lot of kind of thoughts on +this. He's and he's actually a great + + align:start position:0% +this. He's and he's actually a great + + + align:start position:0% +this. He's and he's actually a great +person to talk about this because he + + align:start position:0% +person to talk about this because he + + + align:start position:0% +person to talk about this because he +studies video games, but he does it from + + align:start position:0% +studies video games, but he does it from + + + align:start position:0% +studies video games, but he does it from +an art history background as well, + + align:start position:0% +an art history background as well, + + + align:start position:0% +an art history background as well, +right? And that's particularly useful. + + align:start position:0% +right? And that's particularly useful. + + + align:start position:0% +right? And that's particularly useful. +Um, and uh, you know, he talks about + + align:start position:0% +Um, and uh, you know, he talks about + + + align:start position:0% +Um, and uh, you know, he talks about +some interesting things here. He talks + + align:start position:0% +some interesting things here. He talks + + + align:start position:0% +some interesting things here. He talks +about, you know, similarly similarly to + + align:start position:0% +about, you know, similarly similarly to + + + align:start position:0% +about, you know, similarly similarly to +what Ian was doing. He's talking a bit + + align:start position:0% +what Ian was doing. He's talking a bit + + + align:start position:0% +what Ian was doing. He's talking a bit +about how um you know video games and + + align:start position:0% +about how um you know video games and + + + align:start position:0% +about how um you know video games and +art are are kind of doing some similar + + align:start position:0% +art are are kind of doing some similar + + + align:start position:0% +art are are kind of doing some similar +things at times and yet games you know + + align:start position:0% +things at times and yet games you know + + + align:start position:0% +things at times and yet games you know +have certain affordances that other + + align:start position:0% +have certain affordances that other + + + align:start position:0% +have certain affordances that other +media do not. Um and so uh he says at + + align:start position:0% +media do not. Um and so uh he says at + + + align:start position:0% +media do not. Um and so uh he says at +the end here which I think is + + align:start position:0% +the end here which I think is + + + align:start position:0% +the end here which I think is +interesting all this poses the question + + align:start position:0% +interesting all this poses the question + + + align:start position:0% +interesting all this poses the question +of why are we concerned with giving + + align:start position:0% +of why are we concerned with giving + + + align:start position:0% +of why are we concerned with giving +video games the status of art? This is + + align:start position:0% +video games the status of art? This is + + + align:start position:0% +video games the status of art? This is +one of the reasons why I hate this + + align:start position:0% +one of the reasons why I hate this + + + align:start position:0% +one of the reasons why I hate this +question. Are we simply trying to + + align:start position:0% +question. Are we simply trying to + + + align:start position:0% +question. Are we simply trying to +legitimize them? Does being called quote + + align:start position:0% +legitimize them? Does being called quote + + + align:start position:0% +legitimize them? Does being called quote +unquote art change the qualities of + + align:start position:0% +unquote art change the qualities of + + + align:start position:0% +unquote art change the qualities of +video games? Um only if we can answer + + align:start position:0% +video games? Um only if we can answer + + + align:start position:0% +video games? Um only if we can answer +these questions can we move the + + align:start position:0% +these questions can we move the + + + align:start position:0% +these questions can we move the +conversation forward? And I I think he's + + align:start position:0% +conversation forward? And I I think he's + + + align:start position:0% +conversation forward? And I I think he's +you know he's reacting here to the + + align:start position:0% +you know he's reacting here to the + + + align:start position:0% +you know he's reacting here to the +question itself. Actually he and Ian + + align:start position:0% +question itself. Actually he and Ian + + + align:start position:0% +question itself. Actually he and Ian +both are kind of reacting to the + + align:start position:0% +both are kind of reacting to the + + + align:start position:0% +both are kind of reacting to the +question. Ian saying the question + + align:start position:0% +question. Ian saying the question + + + align:start position:0% +question. Ian saying the question +invalidates itself and John Sharp now + + align:start position:0% +invalidates itself and John Sharp now + + + align:start position:0% +invalidates itself and John Sharp now +saying that we need this question it's + + align:start position:0% +saying that we need this question it's + + + align:start position:0% +saying that we need this question it's +not helping us asking you know how does + + align:start position:0% +not helping us asking you know how does + + + align:start position:0% +not helping us asking you know how does +calling it art what does that do for the + + align:start position:0% +calling it art what does that do for the + + + align:start position:0% +calling it art what does that do for the +medium? That's the important question + + align:start position:0% +medium? That's the important question + + + align:start position:0% +medium? That's the important question +right and so here's some some thoughts + + align:start position:0% +right and so here's some some thoughts + + + align:start position:0% +right and so here's some some thoughts +about the question and and some kind of + + align:start position:0% +about the question and and some kind of + + + align:start position:0% +about the question and and some kind of +more evidence for why I think the + + align:start position:0% +more evidence for why I think the + + + align:start position:0% +more evidence for why I think the +question are video games art is just h + + align:start position:0% +question are video games art is just h + + + align:start position:0% +question are video games art is just h +makes my spine problem. Um, Mary + + align:start position:0% +makes my spine problem. Um, Mary + + + align:start position:0% +makes my spine problem. Um, Mary +Flanigan uh sort of takes it uh takes it + + align:start position:0% +Flanigan uh sort of takes it uh takes it + + + align:start position:0% +Flanigan uh sort of takes it uh takes it +as being assumed that video games are + + align:start position:0% +as being assumed that video games are + + + align:start position:0% +as being assumed that video games are +art, which I think is actually great. In + + align:start position:0% +art, which I think is actually great. In + + + align:start position:0% +art, which I think is actually great. In +Critical Play, she doesn't go to great + + align:start position:0% +Critical Play, she doesn't go to great + + + align:start position:0% +Critical Play, she doesn't go to great +lengths to define video games as art. + + align:start position:0% +lengths to define video games as art. + + + align:start position:0% +lengths to define video games as art. +She just looks at art and she looks at + + align:start position:0% +She just looks at art and she looks at + + + align:start position:0% +She just looks at art and she looks at +games and and compares them. Um, and she + + align:start position:0% +games and and compares them. Um, and she + + + align:start position:0% +games and and compares them. Um, and she +just kind of assumes that this is so and + + align:start position:0% +just kind of assumes that this is so and + + + align:start position:0% +just kind of assumes that this is so and +I think this is a really nice quote from + + align:start position:0% +I think this is a really nice quote from + + + align:start position:0% +I think this is a really nice quote from +from really the beginning of her + + align:start position:0% +from really the beginning of her + + + align:start position:0% +from really the beginning of her +critical playbook. Um, where she says, + + align:start position:0% +critical playbook. Um, where she says, + + + align:start position:0% +critical playbook. Um, where she says, +"Critical play is built on the premise + + align:start position:0% +"Critical play is built on the premise + + + align:start position:0% +"Critical play is built on the premise +that as with other media, games carry + + align:start position:0% +that as with other media, games carry + + + align:start position:0% +that as with other media, games carry +beliefs within their representation + + align:start position:0% +beliefs within their representation + + + align:start position:0% +beliefs within their representation +systems and mechanics." This is really + + align:start position:0% +systems and mechanics." This is really + + + align:start position:0% +systems and mechanics." This is really +important. artists using games as a + + align:start position:0% +important. artists using games as a + + + align:start position:0% +important. artists using games as a +medium of expression. Again, good use of + + align:start position:0% +medium of expression. Again, good use of + + + align:start position:0% +medium of expression. Again, good use of +italics. Um, then manipulate elements + + align:start position:0% +italics. Um, then manipulate elements + + + align:start position:0% +italics. Um, then manipulate elements +common to games, representation, systems + + align:start position:0% +common to games, representation, systems + + + align:start position:0% +common to games, representation, systems +and styles, rules of progress, codes of + + align:start position:0% +and styles, rules of progress, codes of + + + align:start position:0% +and styles, rules of progress, codes of +conduct, context of perception, winning + + align:start position:0% +conduct, context of perception, winning + + + align:start position:0% +conduct, context of perception, winning +and losing paradigms, ways of + + align:start position:0% +and losing paradigms, ways of + + + align:start position:0% +and losing paradigms, ways of +interacting in a game. For they are the + + align:start position:0% +interacting in a game. For they are the + + + align:start position:0% +interacting in a game. For they are the +material properties of game, much like + + align:start position:0% +material properties of game, much like + + + align:start position:0% +material properties of game, much like +marble and chisel or pen and ink bring + + align:start position:0% +marble and chisel or pen and ink bring + + + align:start position:0% +marble and chisel or pen and ink bring +with them their own intended + + align:start position:0% +with them their own intended + + + align:start position:0% +with them their own intended +possibilities, limitations, and + + align:start position:0% +possibilities, limitations, and + + + align:start position:0% +possibilities, limitations, and +conventions. It's a great point. You + + align:start position:0% +conventions. It's a great point. You + + + align:start position:0% +conventions. It's a great point. You +would have a really hard time making a + + align:start position:0% +would have a really hard time making a + + + align:start position:0% +would have a really hard time making a +painting with a chisel um and no paint, + + align:start position:0% +painting with a chisel um and no paint, + + + align:start position:0% +painting with a chisel um and no paint, +right? Like if you were using marble and + + align:start position:0% +right? Like if you were using marble and + + + align:start position:0% +right? Like if you were using marble and +a chisel and you were trying to make a + + align:start position:0% +a chisel and you were trying to make a + + + align:start position:0% +a chisel and you were trying to make a +painting, right? Two different things. + + align:start position:0% +painting, right? Two different things. + + + align:start position:0% +painting, right? Two different things. +Both are art. It's the same thing with + + align:start position:0% +Both are art. It's the same thing with + + + align:start position:0% +Both are art. It's the same thing with +games, right? Games have rule sets. + + align:start position:0% +games, right? Games have rule sets. + + + align:start position:0% +games, right? Games have rule sets. +Games have systems. Uh games have, you + + align:start position:0% +Games have systems. Uh games have, you + + + align:start position:0% +Games have systems. Uh games have, you +know, win loss paradigms. They have all + + align:start position:0% +know, win loss paradigms. They have all + + + align:start position:0% +know, win loss paradigms. They have all +these things that are um kind of + + align:start position:0% +these things that are um kind of + + + align:start position:0% +these things that are um kind of +conventions and and things that we + + align:start position:0% +conventions and and things that we + + + align:start position:0% +conventions and and things that we +associate with with even our definition + + align:start position:0% +associate with with even our definition + + + align:start position:0% +associate with with even our definition +of what a game is, which is at times + + align:start position:0% +of what a game is, which is at times + + + align:start position:0% +of what a game is, which is at times +faulty. Um but but those are our tools. + + align:start position:0% +faulty. Um but but those are our tools. + + + align:start position:0% +faulty. Um but but those are our tools. +Those are how we communicate things. And + + align:start position:0% +Those are how we communicate things. And + + + align:start position:0% +Those are how we communicate things. And +I think her first sentence is really + + align:start position:0% +I think her first sentence is really + + + align:start position:0% +I think her first sentence is really +important. And um I'm guessing with the + + align:start position:0% +important. And um I'm guessing with the + + + align:start position:0% +important. And um I'm guessing with the +with the stuff that you've been talking + + align:start position:0% +with the stuff that you've been talking + + + align:start position:0% +with the stuff that you've been talking +about with them and Gonzalo Frasa um you + + align:start position:0% +about with them and Gonzalo Frasa um you + + + align:start position:0% +about with them and Gonzalo Frasa um you +know that that's kind of coming through + + align:start position:0% +know that that's kind of coming through + + + align:start position:0% +know that that's kind of coming through +and and I actually see that in your + + align:start position:0% +and and I actually see that in your + + + align:start position:0% +and and I actually see that in your +games right you're trying to so for + + align:start position:0% +games right you're trying to so for + + + align:start position:0% +games right you're trying to so for +example I I play tested that FedEx game + + align:start position:0% +example I I play tested that FedEx game + + + align:start position:0% +example I I play tested that FedEx game +and I play tested um the game about + + align:start position:0% +and I play tested um the game about + + + align:start position:0% +and I play tested um the game about +marriage right and there's there's all + + align:start position:0% +marriage right and there's there's all + + + align:start position:0% +marriage right and there's there's all +kinds of meaning in those systems and + + align:start position:0% +kinds of meaning in those systems and + + + align:start position:0% +kinds of meaning in those systems and +meanings in those choices that you get + + align:start position:0% +meanings in those choices that you get + + + align:start position:0% +meanings in those choices that you get +um that that are being communicated and + + align:start position:0% +um that that are being communicated and + + + align:start position:0% +um that that are being communicated and +that's that's very similar to what an + + align:start position:0% +that's that's very similar to what an + + + align:start position:0% +that's that's very similar to what an +artist would do with with any other + + align:start position:0% +artist would do with with any other + + + align:start position:0% +artist would do with with any other +medium right you're you're communicating + + align:start position:0% +medium right you're you're communicating + + + align:start position:0% +medium right you're you're communicating +a message through those and and and + + align:start position:0% +a message through those and and and + + + align:start position:0% +a message through those and and and +sometimes we do it accidentally it's + + align:start position:0% +sometimes we do it accidentally it's + + + align:start position:0% +sometimes we do it accidentally it's +it's not always explicit Right. It's + + align:start position:0% +it's not always explicit Right. It's + + + align:start position:0% +it's not always explicit Right. It's +like we we make something. I I always + + align:start position:0% +like we we make something. I I always + + + align:start position:0% +like we we make something. I I always +say that the the um the graveyard and + + align:start position:0% +say that the the um the graveyard and + + + align:start position:0% +say that the the um the graveyard and +when you get divorced and you put your + + align:start position:0% +when you get divorced and you put your + + + align:start position:0% +when you get divorced and you put your +your divorced person in the graveyard + + align:start position:0% +your divorced person in the graveyard + + + align:start position:0% +your divorced person in the graveyard +was an interesting choice for me because + + align:start position:0% +was an interesting choice for me because + + + align:start position:0% +was an interesting choice for me because +it was creating an equivalence between + + align:start position:0% +it was creating an equivalence between + + + align:start position:0% +it was creating an equivalence between +divorce and death which I think is kind + + align:start position:0% +divorce and death which I think is kind + + + align:start position:0% +divorce and death which I think is kind +of interesting. Um so that's just you + + align:start position:0% +of interesting. Um so that's just you + + + align:start position:0% +of interesting. Um so that's just you +know kind of one interesting example. Um + + align:start position:0% +know kind of one interesting example. Um + + + align:start position:0% +know kind of one interesting example. Um +so Mary Flang in her book talks about + + align:start position:0% +so Mary Flang in her book talks about + + + align:start position:0% +so Mary Flang in her book talks about +this art movement called Plexus. Before + + align:start position:0% +this art movement called Plexus. Before + + + align:start position:0% +this art movement called Plexus. Before +I go on any kind of thoughts or + + align:start position:0% +I go on any kind of thoughts or + + + align:start position:0% +I go on any kind of thoughts or +questions does anybody else think does + + align:start position:0% +questions does anybody else think does + + + align:start position:0% +questions does anybody else think does +anybody think video games aren't art + + align:start position:0% +anybody think video games aren't art + + + align:start position:0% +anybody think video games aren't art +still? It's okay. Oh crap, I'm gonna + + align:start position:0% +still? It's okay. Oh crap, I'm gonna + + + align:start position:0% +still? It's okay. Oh crap, I'm gonna +fight. + + align:start position:0% +fight. + + + align:start position:0% +fight. +>> Totally different. Like when we were + + align:start position:0% +>> Totally different. Like when we were + + + align:start position:0% +>> Totally different. Like when we were +designing our so our project now is you + + align:start position:0% +designing our so our project now is you + + + align:start position:0% +designing our so our project now is you +have to choose a real world + + align:start position:0% +have to choose a real world + + + align:start position:0% +have to choose a real world +>> system and emulate it. + + align:start position:0% +>> system and emulate it. + + + align:start position:0% +>> system and emulate it. +>> That's what we're all working on. + + align:start position:0% +>> That's what we're all working on. + + + align:start position:0% +>> That's what we're all working on. +>> Yeah. + + align:start position:0% +>> Yeah. + + + align:start position:0% +>> Yeah. +>> And one of the big things like that + + align:start position:0% +>> And one of the big things like that + + + align:start position:0% +>> And one of the big things like that +really helped us get started was like + + align:start position:0% +really helped us get started was like + + + align:start position:0% +really helped us get started was like +what is the message we want to get + + align:start position:0% +what is the message we want to get + + + align:start position:0% +what is the message we want to get +across? So we chose evolution was what + + align:start position:0% +across? So we chose evolution was what + + + align:start position:0% +across? So we chose evolution was what +is it about evolution? Do you want to + + align:start position:0% +is it about evolution? Do you want to + + + align:start position:0% +is it about evolution? Do you want to +say that it's random? Do you want to say + + align:start position:0% +say that it's random? Do you want to say + + + align:start position:0% +say that it's random? Do you want to say +that as this? And how do we express + + align:start position:0% +that as this? And how do we express + + + align:start position:0% +that as this? And how do we express +that? How we got into it. + + align:start position:0% +that? How we got into it. + + + align:start position:0% +that? How we got into it. +>> Yeah. No, totally. And it gets even it + + align:start position:0% +>> Yeah. No, totally. And it gets even it + + + align:start position:0% +>> Yeah. No, totally. And it gets even it +gets even crazier when you take when you + + align:start position:0% +gets even crazier when you take when you + + + align:start position:0% +gets even crazier when you take when you +try to look at systems that are not + + align:start position:0% +try to look at systems that are not + + + align:start position:0% +try to look at systems that are not +particularly tangible, right? So, you + + align:start position:0% +particularly tangible, right? So, you + + + align:start position:0% +particularly tangible, right? So, you +know, um maybe you've looked at it, but + + align:start position:0% +know, um maybe you've looked at it, but + + + align:start position:0% +know, um maybe you've looked at it, but +um you know uh Elude is a game about + + align:start position:0% +um you know uh Elude is a game about + + + align:start position:0% +um you know uh Elude is a game about +depression, right? Like there there + + align:start position:0% +depression, right? Like there there + + + align:start position:0% +depression, right? Like there there +there aren't exactly tangible kind of + + align:start position:0% +there aren't exactly tangible kind of + + + align:start position:0% +there aren't exactly tangible kind of +road maps the way there are with like + + align:start position:0% +road maps the way there are with like + + + align:start position:0% +road maps the way there are with like +FedEx systems for for clinical + + align:start position:0% +FedEx systems for for clinical + + + align:start position:0% +FedEx systems for for clinical +depression, right? And yet yet if you're + + align:start position:0% +depression, right? And yet yet if you're + + + align:start position:0% +depression, right? And yet yet if you're +looking at things like emotions, + + align:start position:0% +looking at things like emotions, + + + align:start position:0% +looking at things like emotions, +feelings, um stuff like that that we + + align:start position:0% +feelings, um stuff like that that we + + + align:start position:0% +feelings, um stuff like that that we +might we might call abstract or or um + + align:start position:0% +might we might call abstract or or um + + + align:start position:0% +might we might call abstract or or um +just non- immediate um how do you how do + + align:start position:0% +just non- immediate um how do you how do + + + align:start position:0% +just non- immediate um how do you how do +you uh how do you communicate those in + + align:start position:0% +you uh how do you communicate those in + + + align:start position:0% +you uh how do you communicate those in +systems? Right. It's really tricky. + + align:start position:0% +systems? Right. It's really tricky. + + + align:start position:0% +systems? Right. It's really tricky. +>> I find this is a tougher argument for + + align:start position:0% +>> I find this is a tougher argument for + + + align:start position:0% +>> I find this is a tougher argument for +games which are like more games of + + align:start position:0% +games which are like more games of + + + align:start position:0% +games which are like more games of +chance or more abstract + + align:start position:0% +chance or more abstract + + + align:start position:0% +chance or more abstract +zoker art. + + align:start position:0% +zoker art. + + + align:start position:0% +zoker art. +>> Yeah, I mean it's it's a really good + + align:start position:0% +>> Yeah, I mean it's it's a really good + + + align:start position:0% +>> Yeah, I mean it's it's a really good +question. + + align:start position:0% +question. + + + align:start position:0% +question. +>> What do you what do you say about that? + + align:start position:0% +>> What do you what do you say about that? + + + align:start position:0% +>> What do you what do you say about that? +Yeah. I mean, and I think that falls + + align:start position:0% +Yeah. I mean, and I think that falls + + + align:start position:0% +Yeah. I mean, and I think that falls +along the same lines as like, you know, + + align:start position:0% +along the same lines as like, you know, + + + align:start position:0% +along the same lines as like, you know, +like like I said, I mean, does does + + align:start position:0% +like like I said, I mean, does does + + + align:start position:0% +like like I said, I mean, does does +Ebert consider pornography art? I mean, + + align:start position:0% +Ebert consider pornography art? I mean, + + + align:start position:0% +Ebert consider pornography art? I mean, +it's it's like a really difficult + + align:start position:0% +it's it's like a really difficult + + + align:start position:0% +it's it's like a really difficult +question. And that's that's such a much + + align:start position:0% +question. And that's that's such a much + + + align:start position:0% +question. And that's that's such a much +kind of a much larger kind of art + + align:start position:0% +kind of a much larger kind of art + + + align:start position:0% +kind of a much larger kind of art +history debate, right? About like about + + align:start position:0% +history debate, right? About like about + + + align:start position:0% +history debate, right? About like about +has high culture and low culture + + align:start position:0% +has high culture and low culture + + + align:start position:0% +has high culture and low culture +completely collapsed? Has mass media + + align:start position:0% +completely collapsed? Has mass media + + + align:start position:0% +completely collapsed? Has mass media +proliferation like deteriorated + + align:start position:0% +proliferation like deteriorated + + + align:start position:0% +proliferation like deteriorated +conceptions of, you know, of what, you + + align:start position:0% +conceptions of, you know, of what, you + + + align:start position:0% +conceptions of, you know, of what, you +know, really high culture art are versus + + align:start position:0% +know, really high culture art are versus + + + align:start position:0% +know, really high culture art are versus +low culture? And and and I think that's + + align:start position:0% +low culture? And and and I think that's + + + align:start position:0% +low culture? And and and I think that's +um I I don't have particularly good + + align:start position:0% +um I I don't have particularly good + + + align:start position:0% +um I I don't have particularly good +answers for that. You know, I think just + + align:start position:0% +answers for that. You know, I think just + + + align:start position:0% +answers for that. You know, I think just +as as all of the other media that we + + align:start position:0% +as as all of the other media that we + + + align:start position:0% +as as all of the other media that we +look at, like does a Jerry Brookheimr + + align:start position:0% +look at, like does a Jerry Brookheimr + + + align:start position:0% +look at, like does a Jerry Brookheimr +film count as art, right? Just like we + + align:start position:0% +film count as art, right? Just like we + + + align:start position:0% +film count as art, right? Just like we +would look at that and ask that + + align:start position:0% +would look at that and ask that + + + align:start position:0% +would look at that and ask that +question. Um, we don't then, you know, + + align:start position:0% +question. Um, we don't then, you know, + + + align:start position:0% +question. Um, we don't then, you know, +deny the entire medium of film from from + + align:start position:0% +deny the entire medium of film from from + + + align:start position:0% +deny the entire medium of film from from +the possibility of being artistic. Um + + align:start position:0% +the possibility of being artistic. Um + + + align:start position:0% +the possibility of being artistic. Um +there seems to be this desire because + + align:start position:0% +there seems to be this desire because + + + align:start position:0% +there seems to be this desire because +the majority of games in our sector um + + align:start position:0% +the majority of games in our sector um + + + align:start position:0% +the majority of games in our sector um +which I actually completely disagree + + align:start position:0% +which I actually completely disagree + + + align:start position:0% +which I actually completely disagree +with too because if you go far back + + align:start position:0% +with too because if you go far back + + + align:start position:0% +with too because if you go far back +there they're most I should say video + + align:start position:0% +there they're most I should say video + + + align:start position:0% +there they're most I should say video +games but um because most video games + + align:start position:0% +games but um because most video games + + + align:start position:0% +games but um because most video games +are are kind of commercially intended + + align:start position:0% +are are kind of commercially intended + + + align:start position:0% +are are kind of commercially intended +and involve you know fairly similar + + align:start position:0% +and involve you know fairly similar + + + align:start position:0% +and involve you know fairly similar +themes right does that you know preclude + + align:start position:0% +themes right does that you know preclude + + + align:start position:0% +themes right does that you know preclude +the medium from the possibility of being + + align:start position:0% +the medium from the possibility of being + + + align:start position:0% +the medium from the possibility of being +artistic um you know and I go back to + + align:start position:0% +artistic um you know and I go back to + + + align:start position:0% +artistic um you know and I go back to +that Eber kind of comment about like you + + align:start position:0% +that Eber kind of comment about like you + + + align:start position:0% +that Eber kind of comment about like you +know he he he says they they they can't + + align:start position:0% +know he he he says they they they can't + + + align:start position:0% +know he he he says they they they can't +possibly be or at least you know he says + + align:start position:0% +possibly be or at least you know he says + + + align:start position:0% +possibly be or at least you know he says +never is a long time but not in our + + align:start position:0% +never is a long time but not in our + + + align:start position:0% +never is a long time but not in our +lifetime apparently. Is it possible? So, + + align:start position:0% +lifetime apparently. Is it possible? So, + + + align:start position:0% +lifetime apparently. Is it possible? So, +no, it's a good point. Good question. + + align:start position:0% +no, it's a good point. Good question. + + + align:start position:0% +no, it's a good point. Good question. +>> So, there was actually an interesting uh + + align:start position:0% +>> So, there was actually an interesting uh + + + align:start position:0% +>> So, there was actually an interesting uh +effects with us the game that we're + + align:start position:0% +effects with us the game that we're + + + align:start position:0% +effects with us the game that we're +designing, which is essentially like + + align:start position:0% +designing, which is essentially like + + + align:start position:0% +designing, which is essentially like +city building and city creation in in + + align:start position:0% +city building and city creation in in + + + align:start position:0% +city building and city creation in in +the time of like the Roman Empire. + + align:start position:0% +the time of like the Roman Empire. + + + align:start position:0% +the time of like the Roman Empire. +>> Uh, and we actually didn't intend to + + align:start position:0% +>> Uh, and we actually didn't intend to + + + align:start position:0% +>> Uh, and we actually didn't intend to +like instill any meaning in the game, + + align:start position:0% +like instill any meaning in the game, + + + align:start position:0% +like instill any meaning in the game, +but once we actually designed the + + align:start position:0% +but once we actually designed the + + + align:start position:0% +but once we actually designed the +mechanics and stuff, we realized that it + + align:start position:0% +mechanics and stuff, we realized that it + + + align:start position:0% +mechanics and stuff, we realized that it +was essentially a game about the rich + + align:start position:0% +was essentially a game about the rich + + + align:start position:0% +was essentially a game about the rich +getting richer and trying to control the + + align:start position:0% +getting richer and trying to control the + + + align:start position:0% +getting richer and trying to control the +poor. So, it's like there's almost this + + align:start position:0% +poor. So, it's like there's almost this + + + align:start position:0% +poor. So, it's like there's almost this +like inherent meaning that came out from + + align:start position:0% +like inherent meaning that came out from + + + align:start position:0% +like inherent meaning that came out from +just designing the game. + + align:start position:0% +just designing the game. + + + align:start position:0% +just designing the game. +>> Yeah. Yeah. And you almost can't help, + + align:start position:0% +>> Yeah. Yeah. And you almost can't help, + + + align:start position:0% +>> Yeah. Yeah. And you almost can't help, +right, but but have it happen in some + + align:start position:0% +right, but but have it happen in some + + + align:start position:0% +right, but but have it happen in some +instances. It reminds me of a good thing + + align:start position:0% +instances. It reminds me of a good thing + + + align:start position:0% +instances. It reminds me of a good thing +of um that uh Brenda Brathweight put in + + align:start position:0% +of um that uh Brenda Brathweight put in + + + align:start position:0% +of um that uh Brenda Brathweight put in +one of her talks once which was about + + align:start position:0% +one of her talks once which was about + + + align:start position:0% +one of her talks once which was about +the game uh civilization the the mod + + align:start position:0% +the game uh civilization the the mod + + + align:start position:0% +the game uh civilization the the mod +colonization for Civ 4 which is a great + + align:start position:0% +colonization for Civ 4 which is a great + + + align:start position:0% +colonization for Civ 4 which is a great +mod in which you play one of the + + align:start position:0% +mod in which you play one of the + + + align:start position:0% +mod in which you play one of the +European colonizers and you come over to + + align:start position:0% +European colonizers and you come over to + + + align:start position:0% +European colonizers and you come over to +the new world and um you know there's uh + + align:start position:0% +the new world and um you know there's uh + + + align:start position:0% +the new world and um you know there's uh +there's indigenous peoples there and you + + align:start position:0% +there's indigenous peoples there and you + + + align:start position:0% +there's indigenous peoples there and you +have to kind of negotiate with them at + + align:start position:0% +have to kind of negotiate with them at + + + align:start position:0% +have to kind of negotiate with them at +first but eventually they just kind of + + align:start position:0% +first but eventually they just kind of + + + align:start position:0% +first but eventually they just kind of +um you either beat them up and take + + align:start position:0% +um you either beat them up and take + + + align:start position:0% +um you either beat them up and take +their land or they just give it to you + + align:start position:0% +their land or they just give it to you + + + align:start position:0% +their land or they just give it to you +because you're more powerful than they + + align:start position:0% +because you're more powerful than they + + + align:start position:0% +because you're more powerful than they +are. She was making the point, you know, + + align:start position:0% +are. She was making the point, you know, + + + align:start position:0% +are. She was making the point, you know, +there's this great box art with like the + + align:start position:0% +there's this great box art with like the + + + align:start position:0% +there's this great box art with like the +Native Americans in the corners and like + + align:start position:0% +Native Americans in the corners and like + + + align:start position:0% +Native Americans in the corners and like +the concistador in the middle, you know, + + align:start position:0% +the concistador in the middle, you know, + + + align:start position:0% +the concistador in the middle, you know, +the Spanish and the Dutch. And it's + + align:start position:0% +the Spanish and the Dutch. And it's + + + align:start position:0% +the Spanish and the Dutch. And it's +like, if you were a Native American, how + + align:start position:0% +like, if you were a Native American, how + + + align:start position:0% +like, if you were a Native American, how +would you respond to this game, right? I + + align:start position:0% +would you respond to this game, right? I + + + align:start position:0% +would you respond to this game, right? I +mean, it's like I'm like, "Yeah, I'm I'm + + align:start position:0% +mean, it's like I'm like, "Yeah, I'm I'm + + + align:start position:0% +mean, it's like I'm like, "Yeah, I'm I'm +totally making America again, you know, + + align:start position:0% +totally making America again, you know, + + + align:start position:0% +totally making America again, you know, +and other people would be like, "Oh my + + align:start position:0% +and other people would be like, "Oh my + + + align:start position:0% +and other people would be like, "Oh my +god, you basically just, you know, wiped + + align:start position:0% +god, you basically just, you know, wiped + + + align:start position:0% +god, you basically just, you know, wiped +out my ancestors. Thanks." Um, so it it + + align:start position:0% +out my ancestors. Thanks." Um, so it it + + + align:start position:0% +out my ancestors. Thanks." Um, so it it +it's true. I mean, you kind of sometimes + + align:start position:0% +it's true. I mean, you kind of sometimes + + + align:start position:0% +it's true. I mean, you kind of sometimes +you fall into meaning. It's it's + + align:start position:0% +you fall into meaning. It's it's + + + align:start position:0% +you fall into meaning. It's it's +something that does. And I think, you + + align:start position:0% +something that does. And I think, you + + + align:start position:0% +something that does. And I think, you +know, again, a lot of art does that, + + align:start position:0% +know, again, a lot of art does that, + + + align:start position:0% +know, again, a lot of art does that, +right? And some art did it quite + + align:start position:0% +right? And some art did it quite + + + align:start position:0% +right? And some art did it quite +purposely. um you know where they + + align:start position:0% +purposely. um you know where they + + + align:start position:0% +purposely. um you know where they +weren't divulging the meaning they were + + align:start position:0% +weren't divulging the meaning they were + + + align:start position:0% +weren't divulging the meaning they were +inviting readings of it. Um so Fluxus + + align:start position:0% +inviting readings of it. Um so Fluxus + + + align:start position:0% +inviting readings of it. Um so Fluxus +Fluxus is this um this really + + align:start position:0% +Fluxus is this um this really + + + align:start position:0% +Fluxus is this um this really +interesting uh mid- 20th century art uh + + align:start position:0% +interesting uh mid- 20th century art uh + + + align:start position:0% +interesting uh mid- 20th century art uh +they they rejected the term movement. + + align:start position:0% +they they rejected the term movement. + + + align:start position:0% +they they rejected the term movement. +They called it an attitude. Um that Mary + + align:start position:0% +They called it an attitude. Um that Mary + + + align:start position:0% +They called it an attitude. Um that Mary +Flame talks about a bit in her in her + + align:start position:0% +Flame talks about a bit in her in her + + + align:start position:0% +Flame talks about a bit in her in her +critical playbook and it's actually + + align:start position:0% +critical playbook and it's actually + + + align:start position:0% +critical playbook and it's actually +quite interesting. It's it really starts + + align:start position:0% +quite interesting. It's it really starts + + + align:start position:0% +quite interesting. It's it really starts +out early with with John Cage. Have you + + align:start position:0% +out early with with John Cage. Have you + + + align:start position:0% +out early with with John Cage. Have you +guys heard of him? The composer. Um he's + + align:start position:0% +guys heard of him? The composer. Um he's + + + align:start position:0% +guys heard of him? The composer. Um he's +most famous for this piece of music that + + align:start position:0% +most famous for this piece of music that + + + align:start position:0% +most famous for this piece of music that +he wrote where I forget the duration. + + align:start position:0% +he wrote where I forget the duration. + + + align:start position:0% +he wrote where I forget the duration. +It's like 633. + + align:start position:0% +It's like 633. + + + align:start position:0% +It's like 633. +>> It's four 4 minutes and 33 seconds of + + align:start position:0% +>> It's four 4 minutes and 33 seconds of + + + align:start position:0% +>> It's four 4 minutes and 33 seconds of +not well like not playing. Right. Like + + align:start position:0% +not well like not playing. Right. Like + + + align:start position:0% +not well like not playing. Right. Like +Yeah. He rests. Exactly. So you'd sit + + align:start position:0% +Yeah. He rests. Exactly. So you'd sit + + + align:start position:0% +Yeah. He rests. Exactly. So you'd sit +down at the piano and you'd pull out the + + align:start position:0% +down at the piano and you'd pull out the + + + align:start position:0% +down at the piano and you'd pull out the +music and everyone would hush and then + + align:start position:0% +music and everyone would hush and then + + + align:start position:0% +music and everyone would hush and then +for 4 minutes and 33 seconds you'd sit + + align:start position:0% +for 4 minutes and 33 seconds you'd sit + + + align:start position:0% +for 4 minutes and 33 seconds you'd sit +there possibly with your hands on the + + align:start position:0% +there possibly with your hands on the + + + align:start position:0% +there possibly with your hands on the +keys and then after the time you would + + align:start position:0% +keys and then after the time you would + + + align:start position:0% +keys and then after the time you would +stand up, you'd take your bow and the + + align:start position:0% +stand up, you'd take your bow and the + + + align:start position:0% +stand up, you'd take your bow and the +audience would erupt into you know + + align:start position:0% +audience would erupt into you know + + + align:start position:0% +audience would erupt into you know +incredible applause. Um but he was + + align:start position:0% +incredible applause. Um but he was + + + align:start position:0% +incredible applause. Um but he was +really kind of testing the idea of what + + align:start position:0% +really kind of testing the idea of what + + + align:start position:0% +really kind of testing the idea of what +they what they eventually kind of called + + align:start position:0% +they what they eventually kind of called + + + align:start position:0% +they what they eventually kind of called +scores or event scores, right? This idea + + align:start position:0% +scores or event scores, right? This idea + + + align:start position:0% +scores or event scores, right? This idea +that like music um music is an art form + + align:start position:0% +that like music um music is an art form + + + align:start position:0% +that like music um music is an art form +where you can kind of uh write it down + + align:start position:0% +where you can kind of uh write it down + + + align:start position:0% +where you can kind of uh write it down +and then it becomes performable, right? + + align:start position:0% +and then it becomes performable, right? + + + align:start position:0% +and then it becomes performable, right? +it becomes this kind of thing um that + + align:start position:0% +it becomes this kind of thing um that + + + align:start position:0% +it becomes this kind of thing um that +someone can engage with and and um we + + align:start position:0% +someone can engage with and and um we + + + align:start position:0% +someone can engage with and and um we +don't think of paintings that way. We + + align:start position:0% +don't think of paintings that way. We + + + align:start position:0% +don't think of paintings that way. We +don't think of paintings as having a + + align:start position:0% +don't think of paintings as having a + + + align:start position:0% +don't think of paintings as having a +score, having some kind of you know how + + align:start position:0% +score, having some kind of you know how + + + align:start position:0% +score, having some kind of you know how +do I engage with this, right? It sounds + + align:start position:0% +do I engage with this, right? It sounds + + + align:start position:0% +do I engage with this, right? It sounds +kind of like games. They're they're you + + align:start position:0% +kind of like games. They're they're you + + + align:start position:0% +kind of like games. They're they're you +know figuring out how does interactivity + + align:start position:0% +know figuring out how does interactivity + + + align:start position:0% +know figuring out how does interactivity +work in artistic mediums? Um really + + align:start position:0% +work in artistic mediums? Um really + + + align:start position:0% +work in artistic mediums? Um really +interested in indeterminacy too. Um I + + align:start position:0% +interested in indeterminacy too. Um I + + + align:start position:0% +interested in indeterminacy too. Um I +mean I think you'll see in some of these + + align:start position:0% +mean I think you'll see in some of these + + + align:start position:0% +mean I think you'll see in some of these +examples that they're they're really + + align:start position:0% +examples that they're they're really + + + align:start position:0% +examples that they're they're really +kind of pushing on the boundaries of + + align:start position:0% +kind of pushing on the boundaries of + + + align:start position:0% +kind of pushing on the boundaries of +what um of what what art has been doing + + align:start position:0% +what um of what what art has been doing + + + align:start position:0% +what um of what what art has been doing +to this point. Uh they call it + + align:start position:0% +to this point. Uh they call it + + + align:start position:0% +to this point. Uh they call it +intermedia uh meaning that the more kind + + align:start position:0% +intermedia uh meaning that the more kind + + + align:start position:0% +intermedia uh meaning that the more kind +of um multiple modes that you can use + + align:start position:0% +of um multiple modes that you can use + + + align:start position:0% +of um multiple modes that you can use +for for communicating it. Um was really + + align:start position:0% +for for communicating it. Um was really + + + align:start position:0% +for for communicating it. Um was really +important to the to the attitude. Um + + align:start position:0% +important to the to the attitude. Um + + + align:start position:0% +important to the to the attitude. Um +simplicity was really big right having + + align:start position:0% +simplicity was really big right having + + + align:start position:0% +simplicity was really big right having +you know having kind of basic basic + + align:start position:0% +you know having kind of basic basic + + + align:start position:0% +you know having kind of basic basic +systems and and basic kind of scores. + + align:start position:0% +systems and and basic kind of scores. + + + align:start position:0% +systems and and basic kind of scores. +And then this idea of play um was really + + align:start position:0% +And then this idea of play um was really + + + align:start position:0% +And then this idea of play um was really +kind of important. Um Yoko Ono, it's + + align:start position:0% +kind of important. Um Yoko Ono, it's + + + align:start position:0% +kind of important. Um Yoko Ono, it's +funny, you know, we sort of just + + align:start position:0% +funny, you know, we sort of just + + + align:start position:0% +funny, you know, we sort of just +attached her to John Lennin, but she she + + align:start position:0% +attached her to John Lennin, but she she + + + align:start position:0% +attached her to John Lennin, but she she +was an artist before she was um you + + align:start position:0% +was an artist before she was um you + + + align:start position:0% +was an artist before she was um you +know, just in a relationship with him, + + align:start position:0% +know, just in a relationship with him, + + + align:start position:0% +know, just in a relationship with him, +and she's actually kind of well known as + + align:start position:0% +and she's actually kind of well known as + + + align:start position:0% +and she's actually kind of well known as +one of these kind of Fluxus + + align:start position:0% +one of these kind of Fluxus + + + align:start position:0% +one of these kind of Fluxus +practitioners. Um this is interesting. + + align:start position:0% +practitioners. Um this is interesting. + + + align:start position:0% +practitioners. Um this is interesting. +This is the Fluxus manifesto. Um I kind + + align:start position:0% +This is the Fluxus manifesto. Um I kind + + + align:start position:0% +This is the Fluxus manifesto. Um I kind +of wanted to just put this up because I + + align:start position:0% +of wanted to just put this up because I + + + align:start position:0% +of wanted to just put this up because I +think you can get a little bit of a + + align:start position:0% +think you can get a little bit of a + + + align:start position:0% +think you can get a little bit of a +sense for what they were trying to go + + align:start position:0% +sense for what they were trying to go + + + align:start position:0% +sense for what they were trying to go +for. So um you know they were taking the + + align:start position:0% +for. So um you know they were taking the + + + align:start position:0% +for. So um you know they were taking the +word fluxus and or flux and you know + + align:start position:0% +word fluxus and or flux and you know + + + align:start position:0% +word fluxus and or flux and you know +putting the definition but then they + + align:start position:0% +putting the definition but then they + + + align:start position:0% +putting the definition but then they +were kind of amending it here. So you + + align:start position:0% +were kind of amending it here. So you + + + align:start position:0% +were kind of amending it here. So you +know purge the world of bourgeoa + + align:start position:0% +know purge the world of bourgeoa + + + align:start position:0% +know purge the world of bourgeoa +sickness uh intellectual professional + + align:start position:0% +sickness uh intellectual professional + + + align:start position:0% +sickness uh intellectual professional +and commercialized culture. Purge the + + align:start position:0% +and commercialized culture. Purge the + + + align:start position:0% +and commercialized culture. Purge the +world of dead art, imitation, artificial + + align:start position:0% +world of dead art, imitation, artificial + + + align:start position:0% +world of dead art, imitation, artificial +art, abstract art, illusionistic art, + + align:start position:0% +art, abstract art, illusionistic art, + + + align:start position:0% +art, abstract art, illusionistic art, +mathematical art. I like this. Purge the + + align:start position:0% +mathematical art. I like this. Purge the + + + align:start position:0% +mathematical art. I like this. Purge the +world of Europeanism. + + align:start position:0% +world of Europeanism. + + + align:start position:0% +world of Europeanism. +Don't even know if that's a word. Um + + align:start position:0% +Don't even know if that's a word. Um + + + align:start position:0% +Don't even know if that's a word. Um +>> yeah. Promote a revolutionary flood and + + align:start position:0% +>> yeah. Promote a revolutionary flood and + + + align:start position:0% +>> yeah. Promote a revolutionary flood and +tide in art. um promoting art, anti-art, + + align:start position:0% +tide in art. um promoting art, anti-art, + + + align:start position:0% +tide in art. um promoting art, anti-art, +non-art reality. I mean, these things + + align:start position:0% +non-art reality. I mean, these things + + + align:start position:0% +non-art reality. I mean, these things +these things sound like totally crazy, + + align:start position:0% +these things sound like totally crazy, + + + align:start position:0% +these things sound like totally crazy, +right? I love the I love the to be fully + + align:start position:0% +right? I love the I love the to be fully + + + align:start position:0% +right? I love the I love the to be fully +grasped, but then it crosses out fully, + + align:start position:0% +grasped, but then it crosses out fully, + + + align:start position:0% +grasped, but then it crosses out fully, +right? And and that I don't doubt that + + align:start position:0% +right? And and that I don't doubt that + + + align:start position:0% +right? And and that I don't doubt that +that was completely intentional. Or if + + align:start position:0% +that was completely intentional. Or if + + + align:start position:0% +that was completely intentional. Or if +they wrote fully grass, we're like, "Oh, + + align:start position:0% +they wrote fully grass, we're like, "Oh, + + + align:start position:0% +they wrote fully grass, we're like, "Oh, +this is going to be great, right? I'm + + align:start position:0% +this is going to be great, right? I'm + + + align:start position:0% +this is going to be great, right? I'm +crossing out so you can see that I + + align:start position:0% +crossing out so you can see that I + + + align:start position:0% +crossing out so you can see that I +crossed out fully grasped." We want it + + align:start position:0% +crossed out fully grasped." We want it + + + align:start position:0% +crossed out fully grasped." We want it +to be not fully grasped, you know? We + + align:start position:0% +to be not fully grasped, you know? We + + + align:start position:0% +to be not fully grasped, you know? We +want to be partially grasped by all + + align:start position:0% +want to be partially grasped by all + + + align:start position:0% +want to be partially grasped by all +people. Um not only critics, um talks + + align:start position:0% +people. Um not only critics, um talks + + + align:start position:0% +people. Um not only critics, um talks +and professionals. So, um and it's just + + align:start position:0% +and professionals. So, um and it's just + + + align:start position:0% +and professionals. So, um and it's just +a really interesting thing. And this + + align:start position:0% +a really interesting thing. And this + + + align:start position:0% +a really interesting thing. And this +sort of like screams kind of the avant + + align:start position:0% +sort of like screams kind of the avant + + + align:start position:0% +sort of like screams kind of the avant +guard, right? They were trying to like + + align:start position:0% +guard, right? They were trying to like + + + align:start position:0% +guard, right? They were trying to like +push against boundaries. They're trying + + align:start position:0% +push against boundaries. They're trying + + + align:start position:0% +push against boundaries. They're trying +to figure out what is the edge of the + + align:start position:0% +to figure out what is the edge of the + + + align:start position:0% +to figure out what is the edge of the +medium and then how can we how can we + + align:start position:0% +medium and then how can we how can we + + + align:start position:0% +medium and then how can we how can we +just like, you know, jump way off it. + + align:start position:0% +just like, you know, jump way off it. + + + align:start position:0% +just like, you know, jump way off it. +And um + + align:start position:0% +And um + + + align:start position:0% +And um +some of the classic fluxist works were + + align:start position:0% +some of the classic fluxist works were + + + align:start position:0% +some of the classic fluxist works were +these things called flux boxes or flux + + align:start position:0% +these things called flux boxes or flux + + + align:start position:0% +these things called flux boxes or flux +kits. Um and flux kits tended to have + + align:start position:0% +kits. Um and flux kits tended to have + + + align:start position:0% +kits. Um and flux kits tended to have +event scores. This is one of the most + + align:start position:0% +event scores. This is one of the most + + + align:start position:0% +event scores. This is one of the most +famous called Water Yam by George Breck. + + align:start position:0% +famous called Water Yam by George Breck. + + + align:start position:0% +famous called Water Yam by George Breck. +Um and basically this is a box with 70 + + align:start position:0% +Um and basically this is a box with 70 + + + align:start position:0% +Um and basically this is a box with 70 +event scores. Um, and these are an + + align:start position:0% +event scores. Um, and these are an + + + align:start position:0% +event scores. Um, and these are an +example of kind of event scores. And and + + align:start position:0% +example of kind of event scores. And and + + + align:start position:0% +example of kind of event scores. And and +it's interesting. I mean, event scores + + align:start position:0% +it's interesting. I mean, event scores + + + align:start position:0% +it's interesting. I mean, event scores +really seem like rule systems, right? + + align:start position:0% +really seem like rule systems, right? + + + align:start position:0% +really seem like rule systems, right? +Like they're like the instructions to + + align:start position:0% +Like they're like the instructions to + + + align:start position:0% +Like they're like the instructions to +your board game. Um, except they're + + align:start position:0% +your board game. Um, except they're + + + align:start position:0% +your board game. Um, except they're +they're kind of wacky. I mean, if you + + align:start position:0% +they're kind of wacky. I mean, if you + + + align:start position:0% +they're kind of wacky. I mean, if you +look at you look at air conditioning, + + align:start position:0% +look at you look at air conditioning, + + + align:start position:0% +look at you look at air conditioning, +um, the the rule is move through the + + align:start position:0% +um, the the rule is move through the + + + align:start position:0% +um, the the rule is move through the +place. Um, which is really interesting. + + align:start position:0% +place. Um, which is really interesting. + + + align:start position:0% +place. Um, which is really interesting. +I mean, if you encounter this game and + + align:start position:0% +I mean, if you encounter this game and + + + align:start position:0% +I mean, if you encounter this game and +you're like, "All right, I'm going to + + align:start position:0% +you're like, "All right, I'm going to + + + align:start position:0% +you're like, "All right, I'm going to +play water jam." And then you pull out + + align:start position:0% +play water jam." And then you pull out + + + align:start position:0% +play water jam." And then you pull out +air conditioning, you're like, "Move + + align:start position:0% +air conditioning, you're like, "Move + + + align:start position:0% +air conditioning, you're like, "Move +through the place." Um, and I think + + align:start position:0% +through the place." Um, and I think + + + align:start position:0% +through the place." Um, and I think +that's kind of, you know, pretty + + align:start position:0% +that's kind of, you know, pretty + + + align:start position:0% +that's kind of, you know, pretty +characteristic of the movement, right? + + align:start position:0% +characteristic of the movement, right? + + + align:start position:0% +characteristic of the movement, right? +present you with some sort of objective + + align:start position:0% +present you with some sort of objective + + + align:start position:0% +present you with some sort of objective +or some sort of um some sort of + + align:start position:0% +or some sort of um some sort of + + + align:start position:0% +or some sort of um some sort of +requirement, but one that is kind of uh + + align:start position:0% +requirement, but one that is kind of uh + + + align:start position:0% +requirement, but one that is kind of uh +abstract or nebulous or just, you know, + + align:start position:0% +abstract or nebulous or just, you know, + + + align:start position:0% +abstract or nebulous or just, you know, +kind of strange. This one's even better. + + align:start position:0% +kind of strange. This one's even better. + + + align:start position:0% +kind of strange. This one's even better. +Um on a white chair, a great tape + + align:start position:0% +Um on a white chair, a great tape + + + align:start position:0% +Um on a white chair, a great tape +measure, alphabet, flag, black, and + + align:start position:0% +measure, alphabet, flag, black, and + + + align:start position:0% +measure, alphabet, flag, black, and +spectral colors. Um in this instance, + + align:start position:0% +spectral colors. Um in this instance, + + + align:start position:0% +spectral colors. Um in this instance, +it's not even clear what you're + + align:start position:0% +it's not even clear what you're + + + align:start position:0% +it's not even clear what you're +necessarily supposed to do. Are you + + align:start position:0% +necessarily supposed to do. Are you + + + align:start position:0% +necessarily supposed to do. Are you +supposed to compile these things on a + + align:start position:0% +supposed to compile these things on a + + + align:start position:0% +supposed to compile these things on a +white chair? Um you know, are you + + align:start position:0% +white chair? Um you know, are you + + + align:start position:0% +white chair? Um you know, are you +supposed to sit on a white chair and + + align:start position:0% +supposed to sit on a white chair and + + + align:start position:0% +supposed to sit on a white chair and +hold all of these things? Um it's not + + align:start position:0% +hold all of these things? Um it's not + + + align:start position:0% +hold all of these things? Um it's not +it's not particularly clear. And um and + + align:start position:0% +it's not particularly clear. And um and + + + align:start position:0% +it's not particularly clear. And um and +this is this is you know this is the + + align:start position:0% +this is this is you know this is the + + + align:start position:0% +this is this is you know this is the +playfulness of this movement. This is + + align:start position:0% +playfulness of this movement. This is + + + align:start position:0% +playfulness of this movement. This is +kind of the the energy of this kind of + + align:start position:0% +kind of the the energy of this kind of + + + align:start position:0% +kind of the the energy of this kind of +uh avantgard movement. Um + + align:start position:0% +uh avantgard movement. Um + + + align:start position:0% +uh avantgard movement. Um +you can see kind of the relationship I I + + align:start position:0% +you can see kind of the relationship I I + + + align:start position:0% +you can see kind of the relationship I I +hope between kind of rule systems and + + align:start position:0% +hope between kind of rule systems and + + + align:start position:0% +hope between kind of rule systems and +these the next example is I think + + align:start position:0% +these the next example is I think + + + align:start position:0% +these the next example is I think +another one but but you can see how + + align:start position:0% +another one but but you can see how + + + align:start position:0% +another one but but you can see how +they're kind of playing around with + + align:start position:0% +they're kind of playing around with + + + align:start position:0% +they're kind of playing around with +these ideas. At least they're + + align:start position:0% +these ideas. At least they're + + + align:start position:0% +these ideas. At least they're +incorporating interactivity into these + + align:start position:0% +incorporating interactivity into these + + + align:start position:0% +incorporating interactivity into these +art pieces, right? And keep in mind + + align:start position:0% +art pieces, right? And keep in mind + + + align:start position:0% +art pieces, right? And keep in mind +these are these are being shown in + + align:start position:0% +these are these are being shown in + + + align:start position:0% +these are these are being shown in +galleries. These are being shown in high + + align:start position:0% +galleries. These are being shown in high + + + align:start position:0% +galleries. These are being shown in high +art places, right? These are um being + + align:start position:0% +art places, right? These are um being + + + align:start position:0% +art places, right? These are um being +sent out to their friends as as works of + + align:start position:0% +sent out to their friends as as works of + + + align:start position:0% +sent out to their friends as as works of +of art. Um this one's great. Um this is + + align:start position:0% +of art. Um this one's great. Um this is + + + align:start position:0% +of art. Um this one's great. Um this is +white chess by Yokoono and and it's + + align:start position:0% +white chess by Yokoono and and it's + + + align:start position:0% +white chess by Yokoono and and it's +often kind of depicted on its own and + + align:start position:0% +often kind of depicted on its own and + + + align:start position:0% +often kind of depicted on its own and +you have to imagine what the rules are, + + align:start position:0% +you have to imagine what the rules are, + + + align:start position:0% +you have to imagine what the rules are, +but I actually think her rules as they + + align:start position:0% +but I actually think her rules as they + + + align:start position:0% +but I actually think her rules as they +are written are actually pretty + + align:start position:0% +are written are actually pretty + + + align:start position:0% +are written are actually pretty +important to it. So she says, "Play it + + align:start position:0% +important to it. So she says, "Play it + + + align:start position:0% +important to it. So she says, "Play it +for as long as you can remember who is + + align:start position:0% +for as long as you can remember who is + + + align:start position:0% +for as long as you can remember who is +your opponent and who is your own self." + + align:start position:0% +your opponent and who is your own self." + + + align:start position:0% +your opponent and who is your own self." +Um very interesting wordage, but um so + + align:start position:0% +Um very interesting wordage, but um so + + + align:start position:0% +Um very interesting wordage, but um so +what are the comp what are the + + align:start position:0% +what are the comp what are the + + + align:start position:0% +what are the comp what are the +complications with white chess? Anyone? + + align:start position:0% +complications with white chess? Anyone? + + + align:start position:0% +complications with white chess? Anyone? +Any thoughts based on your perceptions + + align:start position:0% +Any thoughts based on your perceptions + + + align:start position:0% +Any thoughts based on your perceptions +of nonwhite chess or white and black + + align:start position:0% +of nonwhite chess or white and black + + + align:start position:0% +of nonwhite chess or white and black +chess? + + align:start position:0% +chess? + + + align:start position:0% +chess? +>> Yeah. Begin to argue, but that was my + + align:start position:0% +>> Yeah. Begin to argue, but that was my + + + align:start position:0% +>> Yeah. Begin to argue, but that was my +pawn. + + align:start position:0% +pawn. + + + align:start position:0% +pawn. +>> Yes. Yes. You definitely will be hard to + + align:start position:0% +>> Yes. Yes. You definitely will be hard to + + + align:start position:0% +>> Yes. Yes. You definitely will be hard to +keep track of, I would think. Yeah. I + + align:start position:0% +keep track of, I would think. Yeah. I + + + align:start position:0% +keep track of, I would think. Yeah. I +mean, that's why she said as long as you + + align:start position:0% +mean, that's why she said as long as you + + + align:start position:0% +mean, that's why she said as long as you +can remember. Any other um any other + + align:start position:0% +can remember. Any other um any other + + + align:start position:0% +can remember. Any other um any other +kind of weirdness from this? + + align:start position:0% +kind of weirdness from this? + + + align:start position:0% +kind of weirdness from this? +>> Who is friend and who enemy? + + align:start position:0% +>> Who is friend and who enemy? + + + align:start position:0% +>> Who is friend and who enemy? +>> Yeah. I mean, certainly, right? I mean, + + align:start position:0% +>> Yeah. I mean, certainly, right? I mean, + + + align:start position:0% +>> Yeah. I mean, certainly, right? I mean, +this is sort of like, wait, was that my + + align:start position:0% +this is sort of like, wait, was that my + + + align:start position:0% +this is sort of like, wait, was that my +piece? Was that your piece? Not only + + align:start position:0% +piece? Was that your piece? Not only + + + align:start position:0% +piece? Was that your piece? Not only +does that complicate your relationship + + align:start position:0% +does that complicate your relationship + + + align:start position:0% +does that complicate your relationship +to the other player, right? But but now + + align:start position:0% +to the other player, right? But but now + + + align:start position:0% +to the other player, right? But but now +it's like to the game itself, it's like, + + align:start position:0% +it's like to the game itself, it's like, + + + align:start position:0% +it's like to the game itself, it's like, +wait, what was the strategy I was doing? + + align:start position:0% +wait, what was the strategy I was doing? + + + align:start position:0% +wait, what was the strategy I was doing? +>> Friendly fire. + + align:start position:0% +>> Friendly fire. + + + align:start position:0% +>> Friendly fire. +>> Yeah. I mean, it's really hard to keep + + align:start position:0% +>> Yeah. I mean, it's really hard to keep + + + align:start position:0% +>> Yeah. I mean, it's really hard to keep +track of stuff in chess. What about the + + align:start position:0% +track of stuff in chess. What about the + + + align:start position:0% +track of stuff in chess. What about the +board? + + align:start position:0% +board? + + + align:start position:0% +board? +>> You might swap the king and the queen by + + align:start position:0% +>> You might swap the king and the queen by + + + align:start position:0% +>> You might swap the king and the queen by +mistake because you don't have + + align:start position:0% +mistake because you don't have + + + align:start position:0% +mistake because you don't have +>> there's not really any like actual boxes + + align:start position:0% +>> there's not really any like actual boxes + + + align:start position:0% +>> there's not really any like actual boxes +on the board. + + align:start position:0% + + + + align:start position:0% + +>> Yeah, they're all they're all white, + + align:start position:0% +>> Yeah, they're all they're all white, + + + align:start position:0% +>> Yeah, they're all they're all white, +right? So, I mean, that sort of + + align:start position:0% +right? So, I mean, that sort of + + + align:start position:0% +right? So, I mean, that sort of +complicates things a little bit too, + + align:start position:0% +complicates things a little bit too, + + + align:start position:0% +complicates things a little bit too, +right? Because you need to kind of + + align:start position:0% +right? Because you need to kind of + + + align:start position:0% +right? Because you need to kind of +remember how you were moving. This one's + + align:start position:0% +remember how you were moving. This one's + + + align:start position:0% +remember how you were moving. This one's +really big. This is like a garden + + align:start position:0% +really big. This is like a garden + + + align:start position:0% +really big. This is like a garden +installment of of white chess. And I + + align:start position:0% +installment of of white chess. And I + + + align:start position:0% +installment of of white chess. And I +think the cool thing too, I mean this is + + align:start position:0% +think the cool thing too, I mean this is + + + align:start position:0% +think the cool thing too, I mean this is +another example of kind of the movement, + + align:start position:0% +another example of kind of the movement, + + + align:start position:0% +another example of kind of the movement, +right? Um, as long as you have the + + align:start position:0% +right? Um, as long as you have the + + + align:start position:0% +right? Um, as long as you have the +components, you could play this game. + + align:start position:0% +components, you could play this game. + + + align:start position:0% +components, you could play this game. +You could create this art piece. I think + + align:start position:0% +You could create this art piece. I think + + + align:start position:0% +You could create this art piece. I think +for Yokoa, the sense is not go play my + + align:start position:0% +for Yokoa, the sense is not go play my + + + align:start position:0% +for Yokoa, the sense is not go play my +installation of white chess. It's that + + align:start position:0% +installation of white chess. It's that + + + align:start position:0% +installation of white chess. It's that +this is the rules. These are the pieces. + + align:start position:0% +this is the rules. These are the pieces. + + + align:start position:0% +this is the rules. These are the pieces. +It can be played. And that screams game, + + align:start position:0% +It can be played. And that screams game, + + + align:start position:0% +It can be played. And that screams game, +right? I mean, that that that screams + + align:start position:0% +right? I mean, that that that screams + + + align:start position:0% +right? I mean, that that that screams +that kind of portability of a game. Um, + + align:start position:0% +that kind of portability of a game. Um, + + + align:start position:0% +that kind of portability of a game. Um, +and but again, you know, this was this + + align:start position:0% +and but again, you know, this was this + + + align:start position:0% +and but again, you know, this was this +wasn't considered anything but art + + align:start position:0% +wasn't considered anything but art + + + align:start position:0% +wasn't considered anything but art +except probably by people who, you know, + + align:start position:0% +except probably by people who, you know, + + + align:start position:0% +except probably by people who, you know, +turned their nose at this sort of thing + + align:start position:0% +turned their nose at this sort of thing + + + align:start position:0% +turned their nose at this sort of thing +anyway. stuff. Um + + align:start position:0% +anyway. stuff. Um + + + align:start position:0% +anyway. stuff. Um +any thoughts on um any thoughts on what + + align:start position:0% +any thoughts on um any thoughts on what + + + align:start position:0% +any thoughts on um any thoughts on what +what white chess could be uh you know + + align:start position:0% +what white chess could be uh you know + + + align:start position:0% +what white chess could be uh you know +kind of about in a in a + + align:start position:0% +kind of about in a in a + + + align:start position:0% +kind of about in a in a +>> two different sides between one and + + align:start position:0% +>> two different sides between one and + + + align:start position:0% +>> two different sides between one and +>> to + + align:start position:0% +>> to + + + align:start position:0% +>> to +eventually get why am I fighting? Why + + align:start position:0% +eventually get why am I fighting? Why + + + align:start position:0% +eventually get why am I fighting? Why +who is my enemy in this situation? + + align:start position:0% +who is my enemy in this situation? + + + align:start position:0% +who is my enemy in this situation? +>> Sure. Sure. Any other thoughts? + + align:start position:0% +>> Sure. Sure. Any other thoughts? + + + align:start position:0% +>> Sure. Sure. Any other thoughts? +>> Yeah. + + align:start position:0% +>> Yeah. + + + align:start position:0% +>> Yeah. +>> Racial relations. + + align:start position:0% +>> Racial relations. + + + align:start position:0% +>> Racial relations. +>> Sure. Racial relations. I mean, there's + + align:start position:0% +>> Sure. Racial relations. I mean, there's + + + align:start position:0% +>> Sure. Racial relations. I mean, there's +probably like a whole anti-war thing of + + align:start position:0% +probably like a whole anti-war thing of + + + align:start position:0% +probably like a whole anti-war thing of +like, you know, are we actually + + align:start position:0% +like, you know, are we actually + + + align:start position:0% +like, you know, are we actually +destroying ourselves? + + align:start position:0% +destroying ourselves? + + + align:start position:0% +destroying ourselves? +>> Yeah. And and I mean, that's so that's + + align:start position:0% +>> Yeah. And and I mean, that's so that's + + + align:start position:0% +>> Yeah. And and I mean, that's so that's +an interesting thing. Yokoono was a + + align:start position:0% +an interesting thing. Yokoono was a + + + align:start position:0% +an interesting thing. Yokoono was a +decidedly um a decidedly kind of + + align:start position:0% +decidedly um a decidedly kind of + + + align:start position:0% +decidedly um a decidedly kind of +anti-war activist in the time that she + + align:start position:0% +anti-war activist in the time that she + + + align:start position:0% +anti-war activist in the time that she +was making this in the early 60s. I + + align:start position:0% +was making this in the early 60s. I + + + align:start position:0% +was making this in the early 60s. I +mean, one thing that you can't take + + align:start position:0% +mean, one thing that you can't take + + + align:start position:0% +mean, one thing that you can't take +anything for granted. The pieces aren't + + align:start position:0% +anything for granted. The pieces aren't + + + align:start position:0% +anything for granted. The pieces aren't +all black, right? They're they're all + + align:start position:0% +all black, right? They're they're all + + + align:start position:0% +all black, right? They're they're all +white. So, I think the race thing does + + align:start position:0% +white. So, I think the race thing does + + + align:start position:0% +white. So, I think the race thing does +kind of play a factor. The inability to + + align:start position:0% +kind of play a factor. The inability to + + + align:start position:0% +kind of play a factor. The inability to +remember who you're attacking and and + + align:start position:0% +remember who you're attacking and and + + + align:start position:0% +remember who you're attacking and and +who who you are even. And I think that's + + align:start position:0% +who who you are even. And I think that's + + + align:start position:0% +who who you are even. And I think that's +actually why I really like her words + + align:start position:0% +actually why I really like her words + + + align:start position:0% +actually why I really like her words +because for as long as you can remember + + align:start position:0% +because for as long as you can remember + + + align:start position:0% +because for as long as you can remember +who is your opponent and who is your own + + align:start position:0% +who is your opponent and who is your own + + + align:start position:0% +who is your opponent and who is your own +self. There's something about + + align:start position:0% +self. There's something about + + + align:start position:0% +self. There's something about +incorporating your own self in there. + + align:start position:0% +incorporating your own self in there. + + + align:start position:0% +incorporating your own self in there. +Not just saying who you know what your + + align:start position:0% +Not just saying who you know what your + + + align:start position:0% +Not just saying who you know what your +pieces are, right? She's not saying can + + align:start position:0% +pieces are, right? She's not saying can + + + align:start position:0% +pieces are, right? She's not saying can +you remember what your pieces are. She's + + align:start position:0% +you remember what your pieces are. She's + + + align:start position:0% +you remember what your pieces are. She's +saying you know remember who you're + + align:start position:0% +saying you know remember who you're + + + align:start position:0% +saying you know remember who you're +playing against versus who you are. Um + + align:start position:0% +playing against versus who you are. Um + + + align:start position:0% +playing against versus who you are. Um +that's very different verbiage. Um and + + align:start position:0% +that's very different verbiage. Um and + + + align:start position:0% +that's very different verbiage. Um and +so it's it's it's I I think it's very + + align:start position:0% +so it's it's it's I I think it's very + + + align:start position:0% +so it's it's it's I I think it's very +much a game about about who are you + + align:start position:0% +much a game about about who are you + + + align:start position:0% +much a game about about who are you +fighting anyway? Um you know what is the + + align:start position:0% +fighting anyway? Um you know what is the + + + align:start position:0% +fighting anyway? Um you know what is the +point of war? What is the purpose of + + align:start position:0% +point of war? What is the purpose of + + + align:start position:0% +point of war? What is the purpose of +war? Um and how how does war + + align:start position:0% +war? Um and how how does war + + + align:start position:0% +war? Um and how how does war +particularly function? Um, and in the + + align:start position:0% +particularly function? Um, and in the + + + align:start position:0% +particularly function? Um, and in the +rhetoric of the time it it makes a lot + + align:start position:0% +rhetoric of the time it it makes a lot + + + align:start position:0% +rhetoric of the time it it makes a lot +of sense, right? Um, so that's Yoko's + + align:start position:0% +of sense, right? Um, so that's Yoko's + + + align:start position:0% +of sense, right? Um, so that's Yoko's +white chess, which is which is part of + + align:start position:0% +white chess, which is which is part of + + + align:start position:0% +white chess, which is which is part of +the Flexus movement. Yeah, it's it's + + align:start position:0% +the Flexus movement. Yeah, it's it's + + + align:start position:0% +the Flexus movement. Yeah, it's it's +pretty it's pretty cool. And actually, + + align:start position:0% +pretty it's pretty cool. And actually, + + + align:start position:0% +pretty it's pretty cool. And actually, +Fluxus and and artists in this period + + align:start position:0% +Fluxus and and artists in this period + + + align:start position:0% +Fluxus and and artists in this period +have a really interesting relationship + + align:start position:0% +have a really interesting relationship + + + align:start position:0% +have a really interesting relationship +with chess. There's like some quote, and + + align:start position:0% +with chess. There's like some quote, and + + + align:start position:0% +with chess. There's like some quote, and +I'm going to butcher it, but it was um I + + align:start position:0% +I'm going to butcher it, but it was um I + + + align:start position:0% +I'm going to butcher it, but it was um I +think it was Marcel Duchamp saying that + + align:start position:0% +think it was Marcel Duchamp saying that + + + align:start position:0% +think it was Marcel Duchamp saying that +not um not all chess players are + + align:start position:0% +not um not all chess players are + + + align:start position:0% +not um not all chess players are +artists, but all artists are chess + + align:start position:0% +artists, but all artists are chess + + + align:start position:0% +artists, but all artists are chess +players or something like that. he was + + align:start position:0% +players or something like that. he was + + + align:start position:0% +players or something like that. he was +particularly fascinated with chess and + + align:start position:0% +particularly fascinated with chess and + + + align:start position:0% +particularly fascinated with chess and +and you could see elements of chess in + + align:start position:0% +and you could see elements of chess in + + + align:start position:0% +and you could see elements of chess in +his um in his work, you know, either + + align:start position:0% +his um in his work, you know, either + + + align:start position:0% +his um in his work, you know, either +being, you know, painted or whatever. + + align:start position:0% +being, you know, painted or whatever. + + + align:start position:0% +being, you know, painted or whatever. +And so + + align:start position:0% +And so + + + align:start position:0% +And so +>> he was completely obsessed with chess. + + align:start position:0% +>> he was completely obsessed with chess. + + + align:start position:0% +>> he was completely obsessed with chess. +He he was a he was he played it really + + align:start position:0% +He he was a he was he played it really + + + align:start position:0% +He he was a he was he played it really +hard. He wasn't necessarily a very good + + align:start position:0% +hard. He wasn't necessarily a very good + + + align:start position:0% +hard. He wasn't necessarily a very good +player, but he played it a lot. + + align:start position:0% +player, but he played it a lot. + + + align:start position:0% +player, but he played it a lot. +>> Very into it. Um, so now I'm going to + + align:start position:0% +>> Very into it. Um, so now I'm going to + + + align:start position:0% +>> Very into it. Um, so now I'm going to +kind of move out of this sort of Plexus + + align:start position:0% +kind of move out of this sort of Plexus + + + align:start position:0% +kind of move out of this sort of Plexus +move and I just wanted to show you a + + align:start position:0% +move and I just wanted to show you a + + + align:start position:0% +move and I just wanted to show you a +couple examples, but I think this next + + align:start position:0% +couple examples, but I think this next + + + align:start position:0% +couple examples, but I think this next +one is actually sort of an interesting + + align:start position:0% +one is actually sort of an interesting + + + align:start position:0% +one is actually sort of an interesting +this is a current game that I'm really + + align:start position:0% +this is a current game that I'm really + + + align:start position:0% +this is a current game that I'm really +excited about, which is called um 16 + + align:start position:0% +excited about, which is called um 16 + + + align:start position:0% +excited about, which is called um 16 +Tons. Um, and this is a game I + + align:start position:0% +Tons. Um, and this is a game I + + + align:start position:0% +Tons. Um, and this is a game I +unfortunately have not been able to play + + align:start position:0% +unfortunately have not been able to play + + + align:start position:0% +unfortunately have not been able to play +yet, but I've I've witnessed play + + align:start position:0% +yet, but I've I've witnessed play + + + align:start position:0% +yet, but I've I've witnessed play +because it's it's a game for four + + align:start position:0% +because it's it's a game for four + + + align:start position:0% +because it's it's a game for four +players, but this was created by Eric + + align:start position:0% +players, but this was created by Eric + + + align:start position:0% +players, but this was created by Eric +Zimmerman and Natalie Py. And it's um so + + align:start position:0% +Zimmerman and Natalie Py. And it's um so + + + align:start position:0% +Zimmerman and Natalie Py. And it's um so +it's a really interesting game. It's a + + align:start position:0% +it's a really interesting game. It's a + + + align:start position:0% +it's a really interesting game. It's a +little hard to see from these pictures, + + align:start position:0% +little hard to see from these pictures, + + + align:start position:0% +little hard to see from these pictures, +but it's this giant circle, I would say, + + align:start position:0% +but it's this giant circle, I would say, + + + align:start position:0% +but it's this giant circle, I would say, +almost the size of this room of + + align:start position:0% +almost the size of this room of + + + align:start position:0% +almost the size of this room of +corrugated cardboard. Maybe even bigger, + + align:start position:0% +corrugated cardboard. Maybe even bigger, + + + align:start position:0% +corrugated cardboard. Maybe even bigger, +a little bit bigger than this room. But, + + align:start position:0% +a little bit bigger than this room. But, + + + align:start position:0% +a little bit bigger than this room. But, +um, inside you've got this kind of array + + align:start position:0% +um, inside you've got this kind of array + + + align:start position:0% +um, inside you've got this kind of array +of colored um array of colored circles + + align:start position:0% +of colored um array of colored circles + + + align:start position:0% +of colored um array of colored circles +in these pretty hefty steel uh steel + + align:start position:0% +in these pretty hefty steel uh steel + + + align:start position:0% +in these pretty hefty steel uh steel +tubes that have color. Um, and let's + + align:start position:0% +tubes that have color. Um, and let's + + + align:start position:0% +tubes that have color. Um, and let's +like let's go through the rules. I mean, + + align:start position:0% +like let's go through the rules. I mean, + + + align:start position:0% +like let's go through the rules. I mean, +the first thing to notice is that they + + align:start position:0% +the first thing to notice is that they + + + align:start position:0% +the first thing to notice is that they +they contextualize the title 16 tons + + align:start position:0% +they contextualize the title 16 tons + + + align:start position:0% +they contextualize the title 16 tons +with a quote from the from the song. Um, + + align:start position:0% +with a quote from the from the song. Um, + + + align:start position:0% +with a quote from the from the song. Um, +you load 16 tons and what do you get? + + align:start position:0% +you load 16 tons and what do you get? + + + align:start position:0% +you load 16 tons and what do you get? +another day older and deeper in debt. + + align:start position:0% +another day older and deeper in debt. + + + align:start position:0% +another day older and deeper in debt. +Um, so this is doing an interesting + + align:start position:0% +Um, so this is doing an interesting + + + align:start position:0% +Um, so this is doing an interesting +thing that that actually, you know, John + + align:start position:0% +thing that that actually, you know, John + + + align:start position:0% +thing that that actually, you know, John +Sharp, who you can actually see in the + + align:start position:0% +Sharp, who you can actually see in the + + + align:start position:0% +Sharp, who you can actually see in the +middle, thinks is actually particularly + + align:start position:0% +middle, thinks is actually particularly + + + align:start position:0% +middle, thinks is actually particularly +important for for games and games that + + align:start position:0% +important for for games and games that + + + align:start position:0% +important for for games and games that +are kind of working in this art + + align:start position:0% +are kind of working in this art + + + align:start position:0% +are kind of working in this art +movement, is that they declare their + + align:start position:0% +movement, is that they declare their + + + align:start position:0% +movement, is that they declare their +intentionality. Um, whether they declare + + align:start position:0% +intentionality. Um, whether they declare + + + align:start position:0% +intentionality. Um, whether they declare +what what their meaning is or not is + + align:start position:0% +what what their meaning is or not is + + + align:start position:0% +what what their meaning is or not is +less important, but they to be taken + + align:start position:0% +less important, but they to be taken + + + align:start position:0% +less important, but they to be taken +seriously, you need to take yourself + + align:start position:0% +seriously, you need to take yourself + + + align:start position:0% +seriously, you need to take yourself +seriously, I think, was one of the + + align:start position:0% +seriously, I think, was one of the + + + align:start position:0% +seriously, I think, was one of the +things he said. And and I think um, you + + align:start position:0% +things he said. And and I think um, you + + + align:start position:0% +things he said. And and I think um, you +know, this is another great example. We + + align:start position:0% +know, this is another great example. We + + + align:start position:0% +know, this is another great example. We +can talk about how other games maybe in + + align:start position:0% +can talk about how other games maybe in + + + align:start position:0% +can talk about how other games maybe in +the digital space do this, but right now + + align:start position:0% +the digital space do this, but right now + + + align:start position:0% +the digital space do this, but right now +they're already kind of priming you for + + align:start position:0% +they're already kind of priming you for + + + align:start position:0% +they're already kind of priming you for +reading the rules in a way that is + + align:start position:0% +reading the rules in a way that is + + + align:start position:0% +reading the rules in a way that is +different than just oo let's play, + + align:start position:0% +different than just oo let's play, + + + align:start position:0% +different than just oo let's play, +right? I mean, could you imagine if + + align:start position:0% +right? I mean, could you imagine if + + + align:start position:0% +right? I mean, could you imagine if +Monopoly had some sort of um you know, + + align:start position:0% +Monopoly had some sort of um you know, + + + align:start position:0% +Monopoly had some sort of um you know, +like Marxist quote in the front of it or + + align:start position:0% +like Marxist quote in the front of it or + + + align:start position:0% +like Marxist quote in the front of it or +something like that, right? Your + + align:start position:0% +something like that, right? Your + + + align:start position:0% +something like that, right? Your +experience of it would be completely + + align:start position:0% +experience of it would be completely + + + align:start position:0% +experience of it would be completely +different. So, um you set up, you put + + align:start position:0% +different. So, um you set up, you put + + + align:start position:0% +different. So, um you set up, you put +the pieces kind of in this array. Um you + + align:start position:0% +the pieces kind of in this array. Um you + + + align:start position:0% +the pieces kind of in this array. Um you +stand on a number and that indicates + + align:start position:0% +stand on a number and that indicates + + + align:start position:0% +stand on a number and that indicates +what color you are. And this is great. + + align:start position:0% +what color you are. And this is great. + + + align:start position:0% +what color you are. And this is great. +You take out $3. Although you can see in + + align:start position:0% +You take out $3. Although you can see in + + + align:start position:0% +You take out $3. Although you can see in +uh in this second picture, they're + + align:start position:0% +uh in this second picture, they're + + + align:start position:0% +uh in this second picture, they're +playing um what uh what Eric, the + + align:start position:0% +playing um what uh what Eric, the + + + align:start position:0% +playing um what uh what Eric, the +designer, has deemed high stakes uh 16 + + align:start position:0% +designer, has deemed high stakes uh 16 + + + align:start position:0% +designer, has deemed high stakes uh 16 +times where you pull out three $5 bills. + + align:start position:0% +times where you pull out three $5 bills. + + + align:start position:0% +times where you pull out three $5 bills. +Um and so it says how to win. You win + + align:start position:0% +Um and so it says how to win. You win + + + align:start position:0% +Um and so it says how to win. You win +when the two pieces of your color are + + align:start position:0% +when the two pieces of your color are + + + align:start position:0% +when the two pieces of your color are +directly adjacent to each other. Um so + + align:start position:0% +directly adjacent to each other. Um so + + + align:start position:0% +directly adjacent to each other. Um so +diagonally adjacent does not count for a + + align:start position:0% +diagonally adjacent does not count for a + + + align:start position:0% +diagonally adjacent does not count for a +win. The way you play is players take + + align:start position:0% +win. The way you play is players take + + + align:start position:0% +win. The way you play is players take +turns starting with player one. When + + align:start position:0% +turns starting with player one. When + + + align:start position:0% +turns starting with player one. When +it's your turn, you say, "Put me to + + align:start position:0% +it's your turn, you say, "Put me to + + + align:start position:0% +it's your turn, you say, "Put me to +work." Uh players may then offer to pay + + align:start position:0% +work." Uh players may then offer to pay + + + align:start position:0% +work." Uh players may then offer to pay +you one or more dollars in any order. So + + align:start position:0% +you one or more dollars in any order. So + + + align:start position:0% +you one or more dollars in any order. So +anyone can just say, "I'll give you + + align:start position:0% +anyone can just say, "I'll give you + + + align:start position:0% +anyone can just say, "I'll give you +this." um you have to accept the highest + + align:start position:0% +this." um you have to accept the highest + + + align:start position:0% +this." um you have to accept the highest +payment except if there's a tie, right? + + align:start position:0% +payment except if there's a tie, right? + + + align:start position:0% +payment except if there's a tie, right? +Because with, you know, with specific + + align:start position:0% +Because with, you know, with specific + + + align:start position:0% +Because with, you know, with specific +denominations there's very likely to be + + align:start position:0% +denominations there's very likely to be + + + align:start position:0% +denominations there's very likely to be +a tie. Then you get to choose which of + + align:start position:0% +a tie. Then you get to choose which of + + + align:start position:0% +a tie. Then you get to choose which of +the highest biders um you can take and + + align:start position:0% +the highest biders um you can take and + + + align:start position:0% +the highest biders um you can take and +the the person who pays then tells you + + align:start position:0% +the the person who pays then tells you + + + align:start position:0% +the the person who pays then tells you +what move to make. Um and if no one + + align:start position:0% +what move to make. Um and if no one + + + align:start position:0% +what move to make. Um and if no one +offers to pay you, you get to decide + + align:start position:0% +offers to pay you, you get to decide + + + align:start position:0% +offers to pay you, you get to decide +what to do. Um and then it's the next + + align:start position:0% +what to do. Um and then it's the next + + + align:start position:0% +what to do. Um and then it's the next +player's turn and you continue until one + + align:start position:0% +player's turn and you continue until one + + + align:start position:0% +player's turn and you continue until one +player wins. Um, + + align:start position:0% +player wins. Um, + + + align:start position:0% +player wins. Um, +just off the top of your heads, having + + align:start position:0% +just off the top of your heads, having + + + align:start position:0% +just off the top of your heads, having +not even played it, um, it's tough to + + align:start position:0% +not even played it, um, it's tough to + + + align:start position:0% +not even played it, um, it's tough to +critique games when you haven't played, + + align:start position:0% +critique games when you haven't played, + + + align:start position:0% +critique games when you haven't played, +but just looking at the rules and + + align:start position:0% +but just looking at the rules and + + + align:start position:0% +but just looking at the rules and +hearing about it and even kind of I love + + align:start position:0% +hearing about it and even kind of I love + + + align:start position:0% +hearing about it and even kind of I love +that picture on the left because it it + + align:start position:0% +that picture on the left because it it + + + align:start position:0% +that picture on the left because it it +embodies some of the kind of spirit of + + align:start position:0% +embodies some of the kind of spirit of + + + align:start position:0% +embodies some of the kind of spirit of +the play, too. But, um, what are some + + align:start position:0% +the play, too. But, um, what are some + + + align:start position:0% +the play, too. But, um, what are some +interesting things about this rule set + + align:start position:0% +interesting things about this rule set + + + align:start position:0% +interesting things about this rule set +that you notice? + + align:start position:0% +that you notice? + + + align:start position:0% +that you notice? +>> You play with money, but you don't win + + align:start position:0% +>> You play with money, but you don't win + + + align:start position:0% +>> You play with money, but you don't win +money. + + align:start position:0% +money. + + + align:start position:0% +money. +>> Well, that's an interesting question. + + align:start position:0% +>> Well, that's an interesting question. + + + align:start position:0% +>> Well, that's an interesting question. +Uh, what happens to the money at the end + + align:start position:0% +Uh, what happens to the money at the end + + + align:start position:0% +Uh, what happens to the money at the end +of the game? Who knows? Do you keep it? + + align:start position:0% +of the game? Who knows? Do you keep it? + + + align:start position:0% +of the game? Who knows? Do you keep it? +That's unclear. + + align:start position:0% +That's unclear. + + + align:start position:0% +That's unclear. +>> Very, very unclear. And that's one of + + align:start position:0% +>> Very, very unclear. And that's one of + + + align:start position:0% +>> Very, very unclear. And that's one of +the things that's really great about + + align:start position:0% +the things that's really great about + + + align:start position:0% +the things that's really great about +this game, right? Is that that it puts + + align:start position:0% +this game, right? Is that that it puts + + + align:start position:0% +this game, right? Is that that it puts +you into these social situations where + + align:start position:0% +you into these social situations where + + + align:start position:0% +you into these social situations where +now you're playing with real currency + + align:start position:0% +now you're playing with real currency + + + align:start position:0% +now you're playing with real currency +that was your own. And now it's like, + + align:start position:0% +that was your own. And now it's like, + + + align:start position:0% +that was your own. And now it's like, +well, what what happens to this, right? + + align:start position:0% +well, what what happens to this, right? + + + align:start position:0% +well, what what happens to this, right? +And and so it says you win if your + + align:start position:0% +And and so it says you win if your + + + align:start position:0% +And and so it says you win if your +piece, but maybe you you feel like you + + align:start position:0% +piece, but maybe you you feel like you + + + align:start position:0% +piece, but maybe you you feel like you +win if you move the most pieces and you + + align:start position:0% +win if you move the most pieces and you + + + align:start position:0% +win if you move the most pieces and you +have the most money at the end of the + + align:start position:0% +have the most money at the end of the + + + align:start position:0% +have the most money at the end of the +game, right? I mean, you've got this + + align:start position:0% +game, right? I mean, you've got this + + + align:start position:0% +game, right? I mean, you've got this +kind of weird economy in here. Um, and I + + align:start position:0% +kind of weird economy in here. Um, and I + + + align:start position:0% +kind of weird economy in here. Um, and I +think the fact that it's not explicit um + + align:start position:0% +think the fact that it's not explicit um + + + align:start position:0% +think the fact that it's not explicit um +in this rule set is great, right? Right. + + align:start position:0% +in this rule set is great, right? Right. + + + align:start position:0% +in this rule set is great, right? Right. +I mean, that's that's what creates this + + align:start position:0% +I mean, that's that's what creates this + + + align:start position:0% +I mean, that's that's what creates this +sort of potential for kind of an + + align:start position:0% +sort of potential for kind of an + + + align:start position:0% +sort of potential for kind of an +interesting social dynamic. Other things + + align:start position:0% +interesting social dynamic. Other things + + + align:start position:0% +interesting social dynamic. Other things +that are interesting about this game, if + + align:start position:0% +that are interesting about this game, if + + + align:start position:0% +that are interesting about this game, if +you're the only person who has money, + + align:start position:0% +you're the only person who has money, + + + align:start position:0% +you're the only person who has money, +then you basically you can basically win + + align:start position:0% +then you basically you can basically win + + + align:start position:0% +then you basically you can basically win +if you're the only person who has money. + + align:start position:0% +if you're the only person who has money. + + + align:start position:0% +if you're the only person who has money. +Yeah. So, it does require a little bit + + align:start position:0% +Yeah. So, it does require a little bit + + + align:start position:0% +Yeah. So, it does require a little bit +of strategy, too. Um, + + align:start position:0% +of strategy, too. Um, + + + align:start position:0% +of strategy, too. Um, +>> technically from this that setup, could + + align:start position:0% +>> technically from this that setup, could + + + align:start position:0% +>> technically from this that setup, could +you win on the first turn? Because it + + align:start position:0% +you win on the first turn? Because it + + + align:start position:0% +you win on the first turn? Because it +seems you only have do you have two only + + align:start position:0% +seems you only have do you have two only + + + align:start position:0% +seems you only have do you have two only +two pieces of a certain color? + + align:start position:0% +two pieces of a certain color? + + + align:start position:0% +two pieces of a certain color? +>> Yeah, but up on the right assume the + + align:start position:0% +>> Yeah, but up on the right assume the + + + align:start position:0% +>> Yeah, but up on the right assume the +starting position. + + align:start position:0% +starting position. + + + align:start position:0% +starting position. +>> Yeah, I know. And so you so on your turn + + align:start position:0% +>> Yeah, I know. And so you so on your turn + + + align:start position:0% +>> Yeah, I know. And so you so on your turn +you could take one p your piece and and + + align:start position:0% +you could take one p your piece and and + + + align:start position:0% +you could take one p your piece and and +have it be moved to the square right + + align:start position:0% +have it be moved to the square right + + + align:start position:0% +have it be moved to the square right +next to yours. + + align:start position:0% +next to yours. + + + align:start position:0% +next to yours. +>> No move to any Oh. Oh, you have to move + + align:start position:0% +>> No move to any Oh. Oh, you have to move + + + align:start position:0% +>> No move to any Oh. Oh, you have to move +it. + + align:start position:0% +it. + + + align:start position:0% +it. +>> Read the red. + + align:start position:0% +>> Read the red. + + + align:start position:0% +>> Read the red. +>> Oh, any adjacent note. Okay. + + align:start position:0% +>> Oh, any adjacent note. Okay. + + + align:start position:0% +>> Oh, any adjacent note. Okay. +>> I didn't read the adjacent adjacent + + align:start position:0% +>> I didn't read the adjacent adjacent + + + align:start position:0% +>> I didn't read the adjacent adjacent +empty square. Um + + align:start position:0% +empty square. Um + + + align:start position:0% +empty square. Um +>> that's actually really interesting. + + align:start position:0% +>> that's actually really interesting. + + + align:start position:0% +>> that's actually really interesting. +>> Yeah, it's a really weird I mean there I + + align:start position:0% +>> Yeah, it's a really weird I mean there I + + + align:start position:0% +>> Yeah, it's a really weird I mean there I +think the I also think the the you're + + align:start position:0% +think the I also think the the you're + + + align:start position:0% +think the I also think the the you're +you're not you're the agency you have in + + align:start position:0% +you're not you're the agency you have in + + + align:start position:0% +you're not you're the agency you have in +the game to to win is not by moving your + + align:start position:0% +the game to to win is not by moving your + + + align:start position:0% +the game to to win is not by moving your +own pieces. It's by paying someone to do + + align:start position:0% +own pieces. It's by paying someone to do + + + align:start position:0% +own pieces. It's by paying someone to do +the work for you, right? And so then we + + align:start position:0% +the work for you, right? And so then we + + + align:start position:0% +the work for you, right? And so then we +kind of get back to this quote at the + + align:start position:0% +kind of get back to this quote at the + + + align:start position:0% +kind of get back to this quote at the +beginning of the ego is 16 tons and what + + align:start position:0% +beginning of the ego is 16 tons and what + + + align:start position:0% +beginning of the ego is 16 tons and what +do you get another day in deeper debt? + + align:start position:0% +do you get another day in deeper debt? + + + align:start position:0% +do you get another day in deeper debt? +It's like what what is this game about? + + align:start position:0% +It's like what what is this game about? + + + align:start position:0% +It's like what what is this game about? +I mean, it could be about a lot of + + align:start position:0% +I mean, it could be about a lot of + + + align:start position:0% +I mean, it could be about a lot of +things. And I mean, we we we honestly + + align:start position:0% +things. And I mean, we we we honestly + + + align:start position:0% +things. And I mean, we we we honestly +probably shouldn't dissect it until + + align:start position:0% +probably shouldn't dissect it until + + + align:start position:0% +probably shouldn't dissect it until +we've played it. Um I think too the kind + + align:start position:0% +we've played it. Um I think too the kind + + + align:start position:0% +we've played it. Um I think too the kind +of corrugated cardboard, it gets hot + + align:start position:0% +of corrugated cardboard, it gets hot + + + align:start position:0% +of corrugated cardboard, it gets hot +inside of there if you're not outside. + + align:start position:0% +inside of there if you're not outside. + + + align:start position:0% +inside of there if you're not outside. +And that's a really interesting thing + + align:start position:0% +And that's a really interesting thing + + + align:start position:0% +And that's a really interesting thing +too, right? like you're in there, it's + + align:start position:0% +too, right? like you're in there, it's + + + align:start position:0% +too, right? like you're in there, it's +hot, it's sweaty, you've got dirty money + + align:start position:0% +hot, it's sweaty, you've got dirty money + + + align:start position:0% +hot, it's sweaty, you've got dirty money +in your hands, you're moving around + + align:start position:0% +in your hands, you're moving around + + + align:start position:0% +in your hands, you're moving around +these fair, you know, sizable, they have + + align:start position:0% +these fair, you know, sizable, they have + + + align:start position:0% +these fair, you know, sizable, they have +weight to them. That was really + + align:start position:0% +weight to them. That was really + + + align:start position:0% +weight to them. That was really +important, too, right? I mean, this + + align:start position:0% +important, too, right? I mean, this + + + align:start position:0% +important, too, right? I mean, this +could have been played around a table + + align:start position:0% +could have been played around a table + + + align:start position:0% +could have been played around a table +with, you know, go pieces or something, + + align:start position:0% +with, you know, go pieces or something, + + + align:start position:0% +with, you know, go pieces or something, +you know, painted go pieces, but these + + align:start position:0% +you know, painted go pieces, but these + + + align:start position:0% +you know, painted go pieces, but these +are like, you know, these are + + align:start position:0% +are like, you know, these are + + + align:start position:0% +are like, you know, these are +substantial steel pieces that you've got + + align:start position:0% +substantial steel pieces that you've got + + + align:start position:0% +substantial steel pieces that you've got +to pick up and move. Um, and, you know, + + align:start position:0% +to pick up and move. Um, and, you know, + + + align:start position:0% +to pick up and move. Um, and, you know, +obviously the well, the song was about + + align:start position:0% +obviously the well, the song was about + + + align:start position:0% +obviously the well, the song was about +kind of manual labor. Um, + + align:start position:0% +kind of manual labor. Um, + + + align:start position:0% +kind of manual labor. Um, +so this is a really interesting game. + + align:start position:0% +so this is a really interesting game. + + + align:start position:0% +so this is a really interesting game. +This was this was released at the art + + align:start position:0% +This was this was released at the art + + + align:start position:0% +This was this was released at the art +history of games conference last year + + align:start position:0% +history of games conference last year + + + align:start position:0% +history of games conference last year +and it did well at indicate this year it + + align:start position:0% +and it did well at indicate this year it + + + align:start position:0% +and it did well at indicate this year it +won the uh developers choice award. Um + + align:start position:0% +won the uh developers choice award. Um + + + align:start position:0% +won the uh developers choice award. Um +and it's it's it's really cool. I want + + align:start position:0% +and it's it's it's really cool. I want + + + align:start position:0% +and it's it's it's really cool. I want +to try to get it up to MIT so that we + + align:start position:0% +to try to get it up to MIT so that we + + + align:start position:0% +to try to get it up to MIT so that we +can all play it. + + align:start position:0% +can all play it. + + + align:start position:0% +can all play it. +>> It occurs to me that you could if you + + align:start position:0% +>> It occurs to me that you could if you + + + align:start position:0% +>> It occurs to me that you could if you +play by rules where you keep the money + + align:start position:0% +play by rules where you keep the money + + + align:start position:0% +play by rules where you keep the money +you get at the end of the game. You + + align:start position:0% +you get at the end of the game. You + + + align:start position:0% +you get at the end of the game. You +basically could throw the game to get + + align:start position:0% +basically could throw the game to get + + + align:start position:0% +basically could throw the game to get +all the money. + + align:start position:0% +all the money. + + + align:start position:0% +all the money. +>> Yeah. I mean you could try you could try + + align:start position:0% +>> Yeah. I mean you could try you could try + + + align:start position:0% +>> Yeah. I mean you could try you could try +right but but you know people are going + + align:start position:0% +right but but you know people are going + + + align:start position:0% +right but but you know people are going +to know what you're doing you know and + + align:start position:0% +to know what you're doing you know and + + + align:start position:0% +to know what you're doing you know and +people are going to see your strategy. + + align:start position:0% +people are going to see your strategy. + + + align:start position:0% +people are going to see your strategy. +So it's it's + + align:start position:0% +So it's it's + + + align:start position:0% +So it's it's +>> not going to pay you Jack. + + align:start position:0% +>> not going to pay you Jack. + + + align:start position:0% +>> not going to pay you Jack. +>> Yeah. Yeah, I mean the multiplayer gets + + align:start position:0% +>> Yeah. Yeah, I mean the multiplayer gets + + + align:start position:0% +>> Yeah. Yeah, I mean the multiplayer gets +the multi multiplayer the you know the + + align:start position:0% +the multi multiplayer the you know the + + + align:start position:0% +the multi multiplayer the you know the +game gets in this. Um so I mean again + + align:start position:0% +game gets in this. Um so I mean again + + + align:start position:0% +game gets in this. Um so I mean again +like just kind of cycling back to what + + align:start position:0% +like just kind of cycling back to what + + + align:start position:0% +like just kind of cycling back to what +we're talking about. I mean is this art + + align:start position:0% +we're talking about. I mean is this art + + + align:start position:0% +we're talking about. I mean is this art +you know it would be hard for me to call + + align:start position:0% +you know it would be hard for me to call + + + align:start position:0% +you know it would be hard for me to call +it much of anything else. Um + + align:start position:0% +it much of anything else. Um + + + align:start position:0% +it much of anything else. Um +so this is like one of my one of my + + align:start position:0% +so this is like one of my one of my + + + align:start position:0% +so this is like one of my one of my +favorite games. Uh it's certainly my + + align:start position:0% +favorite games. Uh it's certainly my + + + align:start position:0% +favorite games. Uh it's certainly my +favorite Jason Norade. Who's played + + align:start position:0% +favorite Jason Norade. Who's played + + + align:start position:0% +favorite Jason Norade. Who's played +gravitation here? A couple of you. All + + align:start position:0% +gravitation here? A couple of you. All + + + align:start position:0% +gravitation here? A couple of you. All +right cool. And a bunch of you haven't. + + align:start position:0% +right cool. And a bunch of you haven't. + + + align:start position:0% +right cool. And a bunch of you haven't. +That's awesome. So I'll get one of you + + align:start position:0% +That's awesome. So I'll get one of you + + + align:start position:0% +That's awesome. So I'll get one of you +to play it. Um, one thing I want to + + align:start position:0% +to play it. Um, one thing I want to + + + align:start position:0% +to play it. Um, one thing I want to +point out with this, I mean, we can talk + + align:start position:0% +point out with this, I mean, we can talk + + + align:start position:0% +point out with this, I mean, we can talk +after someone's played Gravitation a + + align:start position:0% +after someone's played Gravitation a + + + align:start position:0% +after someone's played Gravitation a +little bit about um, uh, about, you + + align:start position:0% +little bit about um, uh, about, you + + + align:start position:0% +little bit about um, uh, about, you +know, what we think about the game + + align:start position:0% +know, what we think about the game + + + align:start position:0% +know, what we think about the game +itself, but but I think this quote is + + align:start position:0% +itself, but but I think this quote is + + + align:start position:0% +itself, but but I think this quote is +interesting. You know, he has artist + + align:start position:0% +interesting. You know, he has artist + + + align:start position:0% +interesting. You know, he has artist +statements with all of his games. Um, + + align:start position:0% +statements with all of his games. Um, + + + align:start position:0% +statements with all of his games. Um, +some of them say more, some of them say + + align:start position:0% +some of them say more, some of them say + + + align:start position:0% +some of them say more, some of them say +less. This one responded because this + + align:start position:0% +less. This one responded because this + + + align:start position:0% +less. This one responded because this +was after Passage was released, and I + + align:start position:0% +was after Passage was released, and I + + + align:start position:0% +was after Passage was released, and I +think you guys have all seen Passage, + + align:start position:0% +think you guys have all seen Passage, + + + align:start position:0% +think you guys have all seen Passage, +right? And you can you can immediately + + align:start position:0% +right? And you can you can immediately + + + align:start position:0% +right? And you can you can immediately +identify the aesthetic similarities + + align:start position:0% +identify the aesthetic similarities + + + align:start position:0% +identify the aesthetic similarities +because the character is exactly the + + align:start position:0% +because the character is exactly the + + + align:start position:0% +because the character is exactly the +same. Um, and he was responding to + + align:start position:0% +same. Um, and he was responding to + + + align:start position:0% +same. Um, and he was responding to +criticism from people about his pixel + + align:start position:0% +criticism from people about his pixel + + + align:start position:0% +criticism from people about his pixel +art and why did he go for pixel art? Um, + + align:start position:0% +art and why did he go for pixel art? Um, + + + align:start position:0% +art and why did he go for pixel art? Um, +but he says, "I now see ultra- lowres + + align:start position:0% +but he says, "I now see ultra- lowres + + + align:start position:0% +but he says, "I now see ultra- lowres +pixel art as a kind of digital + + align:start position:0% +pixel art as a kind of digital + + + align:start position:0% +pixel art as a kind of digital +cartooning. It stands right on the line + + align:start position:0% +cartooning. It stands right on the line + + + align:start position:0% +cartooning. It stands right on the line +between the symbolic and the + + align:start position:0% +between the symbolic and the + + + align:start position:0% +between the symbolic and the +representational, leaving plenty of room + + align:start position:0% +representational, leaving plenty of room + + + align:start position:0% +representational, leaving plenty of room +for viewer interpretation. Why draw + + align:start position:0% +for viewer interpretation. Why draw + + + align:start position:0% +for viewer interpretation. Why draw +sideburns when the viewers can imagine + + align:start position:0% +sideburns when the viewers can imagine + + + align:start position:0% +sideburns when the viewers can imagine +sideburns on their own? You just need to + + align:start position:0% +sideburns on their own? You just need to + + + align:start position:0% +sideburns on their own? You just need to +give them something to pin their + + align:start position:0% +give them something to pin their + + + align:start position:0% +give them something to pin their +imagination on, something to guide them + + align:start position:0% +imagination on, something to guide them + + + align:start position:0% +imagination on, something to guide them +a bit. Cartoons are perfect for that." + + align:start position:0% +a bit. Cartoons are perfect for that." + + + align:start position:0% +a bit. Cartoons are perfect for that." +And and I think that's a really + + align:start position:0% +And and I think that's a really + + + align:start position:0% +And and I think that's a really +interesting point. And I think what he's + + align:start position:0% +interesting point. And I think what he's + + + align:start position:0% +interesting point. And I think what he's +what he's also suggesting here, which is + + align:start position:0% +what he's also suggesting here, which is + + + align:start position:0% +what he's also suggesting here, which is +maybe not clear, is that this is doing a + + align:start position:0% +maybe not clear, is that this is doing a + + + align:start position:0% +maybe not clear, is that this is doing a +similar thing to what that quote from + + align:start position:0% +similar thing to what that quote from + + + align:start position:0% +similar thing to what that quote from +the music does. It's priming your + + align:start position:0% +the music does. It's priming your + + + align:start position:0% +the music does. It's priming your +experience of the play. Right? You load + + align:start position:0% +experience of the play. Right? You load + + + align:start position:0% +experience of the play. Right? You load +up this game, you see that it's got this + + align:start position:0% +up this game, you see that it's got this + + + align:start position:0% +up this game, you see that it's got this +low res pixel art that we now associate + + align:start position:0% +low res pixel art that we now associate + + + align:start position:0% +low res pixel art that we now associate +with this kind of art, game movement, + + align:start position:0% +with this kind of art, game movement, + + + align:start position:0% +with this kind of art, game movement, +and you're ready to read this in another + + align:start position:0% +and you're ready to read this in another + + + align:start position:0% +and you're ready to read this in another +way. Um, if I gave you a firsterson + + align:start position:0% +way. Um, if I gave you a firsterson + + + align:start position:0% +way. Um, if I gave you a firsterson +shooter, um, and told you nothing about + + align:start position:0% +shooter, um, and told you nothing about + + + align:start position:0% +shooter, um, and told you nothing about +it except that it was going to be the + + align:start position:0% +it except that it was going to be the + + + align:start position:0% +it except that it was going to be the +fastest, awesomest multiplayer + + align:start position:0% +fastest, awesomest multiplayer + + + align:start position:0% +fastest, awesomest multiplayer +first-person shooter experience, but it + + align:start position:0% +first-person shooter experience, but it + + + align:start position:0% +first-person shooter experience, but it +looked like this. Um, + + align:start position:0% +looked like this. Um, + + + align:start position:0% +looked like this. Um, +you know, would you be inclined to read + + align:start position:0% +you know, would you be inclined to read + + + align:start position:0% +you know, would you be inclined to read +it like an art game? I mean, I I don't + + align:start position:0% +it like an art game? I mean, I I don't + + + align:start position:0% +it like an art game? I mean, I I don't +know. Um, but but certainly in this + + align:start position:0% +know. Um, but but certainly in this + + + align:start position:0% +know. Um, but but certainly in this +instance with these kind of little + + align:start position:0% +instance with these kind of little + + + align:start position:0% +instance with these kind of little +games, right, this this sort of pixel + + align:start position:0% +games, right, this this sort of pixel + + + align:start position:0% +games, right, this this sort of pixel +art aesthetic um that you see being + + align:start position:0% +art aesthetic um that you see being + + + align:start position:0% +art aesthetic um that you see being +duplicated in a lot of places is is sort + + align:start position:0% +duplicated in a lot of places is is sort + + + align:start position:0% +duplicated in a lot of places is is sort +of um I don't know, priming the pump. + + align:start position:0% +of um I don't know, priming the pump. + + + align:start position:0% +of um I don't know, priming the pump. +It's it's establishing some sort of + + align:start position:0% +It's it's establishing some sort of + + + align:start position:0% +It's it's establishing some sort of +context in which you can read this game. + + align:start position:0% +context in which you can read this game. + + + align:start position:0% +context in which you can read this game. +Um, so who wants to play uh gravitation? + + align:start position:0% +Um, so who wants to play uh gravitation? + + + align:start position:0% +Um, so who wants to play uh gravitation? +Actually, let me Oops. No, that's not + + align:start position:0% +Actually, let me Oops. No, that's not + + + align:start position:0% +Actually, let me Oops. No, that's not +supposed to happen. I wanted to click on + + align:start position:0% +supposed to happen. I wanted to click on + + + align:start position:0% +supposed to happen. I wanted to click on +the link. Oh, because I clicked on my + + align:start position:0% +the link. Oh, because I clicked on my + + + align:start position:0% +the link. Oh, because I clicked on my +screen, not this screen. And all it does + + align:start position:0% +screen, not this screen. And all it does + + + align:start position:0% +screen, not this screen. And all it does +is take me out of here. + + align:start position:0% +is take me out of here. + + + align:start position:0% +is take me out of here. +>> Me not being mirrored might be a + + align:start position:0% +>> Me not being mirrored might be a + + + align:start position:0% +>> Me not being mirrored might be a +problem. Let's see. + + align:start position:0% +problem. Let's see. + + + align:start position:0% +problem. Let's see. +Let's see what screen this loads up on. + + align:start position:0% +Let's see what screen this loads up on. + + + align:start position:0% +Let's see what screen this loads up on. +Both one. Crap. Okay, hold on one sec. I + + align:start position:0% +Both one. Crap. Okay, hold on one sec. I + + + align:start position:0% +Both one. Crap. Okay, hold on one sec. I +got to mirror my screen. + + align:start position:0% + + + + align:start position:0% + +Um, I I should not be choosing who plays + + align:start position:0% +Um, I I should not be choosing who plays + + + align:start position:0% +Um, I I should not be choosing who plays +who wants to. Uh, I can't make a choice. + + align:start position:0% +who wants to. Uh, I can't make a choice. + + + align:start position:0% +who wants to. Uh, I can't make a choice. +Who wants to do it? + + align:start position:0% +Who wants to do it? + + + align:start position:0% +Who wants to do it? +>> Interesting that it's a version zero. + + align:start position:0% +>> Interesting that it's a version zero. + + + align:start position:0% +>> Interesting that it's a version zero. +>> Yes. + + align:start position:0% +>> Yes. + + + align:start position:0% +>> Yes. +>> I have to explicitly make that the case. + + align:start position:0% +>> I have to explicitly make that the case. + + + align:start position:0% +>> I have to explicitly make that the case. +>> Uh, + + align:start position:0% +>> Uh, + + + align:start position:0% +>> Uh, +>> anybody. It's It's free. It's free to + + align:start position:0% +>> anybody. It's It's free. It's free to + + + align:start position:0% +>> anybody. It's It's free. It's free to +download. So, if you don't play it now, + + align:start position:0% +download. So, if you don't play it now, + + + align:start position:0% +download. So, if you don't play it now, +you can play it on your own. + + align:start position:0% +you can play it on your own. + + + align:start position:0% +you can play it on your own. +>> We have a few games, right? So, what's + + align:start position:0% +>> We have a few games, right? So, what's + + + align:start position:0% +>> We have a few games, right? So, what's +that? + + align:start position:0% +that? + + + align:start position:0% +that? +>> We have a few games, right? So, + + align:start position:0% +>> We have a few games, right? So, + + + align:start position:0% +>> We have a few games, right? So, +>> Oh, yeah. We have a few. So, yeah. + + align:start position:0% +>> Oh, yeah. We have a few. So, yeah. + + + align:start position:0% +>> Oh, yeah. We have a few. So, yeah. +Getting a few different opportunities to + + align:start position:0% +Getting a few different opportunities to + + + align:start position:0% +Getting a few different opportunities to +play. So, anybody jump over and and like + + align:start position:0% +play. So, anybody jump over and and like + + + align:start position:0% +play. So, anybody jump over and and like +>> we'll start with Jason and then we'll do + + align:start position:0% +>> we'll start with Jason and then we'll do + + + align:start position:0% +>> we'll start with Jason and then we'll do +kind of jumping into + + align:start position:0% +kind of jumping into + + + align:start position:0% +kind of jumping into +>> and actually if you wouldn't mind + + align:start position:0% +>> and actually if you wouldn't mind + + + align:start position:0% +>> and actually if you wouldn't mind +talking about your experience of playing + + align:start position:0% +talking about your experience of playing + + + align:start position:0% +talking about your experience of playing +Gravitation as you play it, you know, + + align:start position:0% +Gravitation as you play it, you know, + + + align:start position:0% +Gravitation as you play it, you know, +like like let's play the + + align:start position:0% +like like let's play the + + + align:start position:0% +like like let's play the +>> the live gravitation. + + align:start position:0% +>> the live gravitation. + + + align:start position:0% +>> the live gravitation. +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +>> Okay. Oh, I seem to have restricted you + + align:start position:0% +>> Okay. Oh, I seem to have restricted you + + + align:start position:0% +>> Okay. Oh, I seem to have restricted you +and it's falling. + + align:start position:0% +and it's falling. + + + align:start position:0% +and it's falling. +>> Oh, it is falling. + + align:start position:0% +>> Oh, it is falling. + + + align:start position:0% +>> Oh, it is falling. +>> Oh, wait. Oh, I + + align:start position:0% +>> Oh, wait. Oh, I + + + align:start position:0% +>> Oh, wait. Oh, I +>> Oh, I know. + + align:start position:0% +>> Oh, I know. + + + align:start position:0% +>> Oh, I know. +>> Oh, never mind. + + align:start position:0% +>> Oh, never mind. + + + align:start position:0% +>> Oh, never mind. +She stole your ball. Oh, she plays with + + align:start position:0% +She stole your ball. Oh, she plays with + + + align:start position:0% +She stole your ball. Oh, she plays with +you. She stole it. + + align:start position:0% +you. She stole it. + + + align:start position:0% +you. She stole it. +>> I hate her. I stole her ball. + + align:start position:0% +>> I hate her. I stole her ball. + + + align:start position:0% +>> I hate her. I stole her ball. +>> She seemed to like you, but she stole it + + align:start position:0% +>> She seemed to like you, but she stole it + + + align:start position:0% +>> She seemed to like you, but she stole it +for a little bit, but now she seems to + + align:start position:0% +for a little bit, but now she seems to + + + align:start position:0% +for a little bit, but now she seems to +be playing, which is better. + + align:start position:0% +be playing, which is better. + + + align:start position:0% +be playing, which is better. +>> Yes. Hurry up. + + align:start position:0% +>> Yes. Hurry up. + + + align:start position:0% +>> Yes. Hurry up. +>> We seem to be bouncing it back and + + align:start position:0% +>> We seem to be bouncing it back and + + + align:start position:0% +>> We seem to be bouncing it back and +forth. My screen gets bigger whenever I + + align:start position:0% +forth. My screen gets bigger whenever I + + + align:start position:0% +forth. My screen gets bigger whenever I +successfully do so. And it's getting + + align:start position:0% +successfully do so. And it's getting + + + align:start position:0% +successfully do so. And it's getting +brighter than earlier. + + align:start position:0% +brighter than earlier. + + + align:start position:0% +brighter than earlier. +>> A gets bigger when she loves you. + + align:start position:0% +>> A gets bigger when she loves you. + + + align:start position:0% +>> A gets bigger when she loves you. +>> Screaming thing + + align:start position:0% +>> Screaming thing + + + align:start position:0% +>> Screaming thing +more. Yay. + + align:start position:0% +more. Yay. + + + align:start position:0% +more. Yay. +>> Hit it up there. + + align:start position:0% +>> Hit it up there. + + + align:start position:0% +>> Hit it up there. +>> What happens when + + align:start position:0% +>> What happens when + + + align:start position:0% +>> What happens when +>> you're on fire? + + align:start position:0% + + + + align:start position:0% + +>> You're on fire. This seems bad. + + align:start position:0% +>> You're on fire. This seems bad. + + + align:start position:0% +>> You're on fire. This seems bad. +>> Really confused. + + align:start position:0% +>> Really confused. + + + align:start position:0% +>> Really confused. +>> You should go to the furnace. + + align:start position:0% + + + + align:start position:0% + +>> Oh, now you're not on fire. That makes + + align:start position:0% +>> Oh, now you're not on fire. That makes + + + align:start position:0% +>> Oh, now you're not on fire. That makes +sense. + + align:start position:0% + + + + align:start position:0% + +Whoa. + + align:start position:0% +Whoa. + + + align:start position:0% +Whoa. +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +Wait, can you bounce the ball up there? + + align:start position:0% +Wait, can you bounce the ball up there? + + + align:start position:0% +Wait, can you bounce the ball up there? +>> I didn't see people jump high. How do I + + align:start position:0% +>> I didn't see people jump high. How do I + + + align:start position:0% +>> I didn't see people jump high. How do I +get up there? + + align:start position:0% +get up there? + + + align:start position:0% +get up there? +>> Oh, there we go. + + align:start position:0% +>> Oh, there we go. + + + align:start position:0% +>> Oh, there we go. +>> Not always the case. + + align:start position:0% +>> Not always the case. + + + align:start position:0% +>> Not always the case. +>> Whoa. + + align:start position:0% +>> Whoa. + + + align:start position:0% +>> Whoa. +>> What's that star? + + align:start position:0% +>> What's that star? + + + align:start position:0% +>> What's that star? +>> Or wall jump. + + align:start position:0% +>> Or wall jump. + + + align:start position:0% +>> Or wall jump. +>> Uh-oh. Well, now you can bounce the + + align:start position:0% +>> Uh-oh. Well, now you can bounce the + + + align:start position:0% +>> Uh-oh. Well, now you can bounce the +ball. + + align:start position:0% +ball. + + + align:start position:0% +ball. +>> Oh, you can jump higher when she size of + + align:start position:0% +>> Oh, you can jump higher when she size of + + + align:start position:0% +>> Oh, you can jump higher when she size of +the screen dictates how high you can + + align:start position:0% +the screen dictates how high you can + + + align:start position:0% +the screen dictates how high you can +jump. + + align:start position:0% +jump. + + + align:start position:0% +jump. +>> Okay, so I guess you'll bounce it more. + + align:start position:0% + + + + align:start position:0% + +Oh, is gra Oh, there. + + align:start position:0% +Oh, is gra Oh, there. + + + align:start position:0% +Oh, is gra Oh, there. +>> You're just using her. + + align:start position:0% +>> You're just using her. + + + align:start position:0% +>> You're just using her. +>> I'm on fire again. + + align:start position:0% +>> I'm on fire again. + + + align:start position:0% +>> I'm on fire again. +>> How could you? + + align:start position:0% +>> How could you? + + + align:start position:0% +>> How could you? +>> Oh, but you're not on fire. + + align:start position:0% +>> Oh, but you're not on fire. + + + align:start position:0% +>> Oh, but you're not on fire. +>> She's not going to love you very soon. + + align:start position:0% +>> She's not going to love you very soon. + + + align:start position:0% +>> She's not going to love you very soon. +>> Yeah, apparently + + align:start position:0% +>> Yeah, apparently + + + align:start position:0% +>> Yeah, apparently +star is is also good. + + align:start position:0% +star is is also good. + + + align:start position:0% +star is is also good. +>> At least not she presumably loves me. + + align:start position:0% +>> At least not she presumably loves me. + + + align:start position:0% +>> At least not she presumably loves me. +>> Oh, no. + + align:start position:0% +>> Oh, no. + + + align:start position:0% +>> Oh, no. +>> Yeah, but it's faster and faster the + + align:start position:0% +>> Yeah, but it's faster and faster the + + + align:start position:0% +>> Yeah, but it's faster and faster the +higher up you get, I think. + + align:start position:0% +higher up you get, I think. + + + align:start position:0% +higher up you get, I think. +>> Yeah. + + align:start position:0% +>> Yeah. + + + align:start position:0% +>> Yeah. +>> Weird. Or maybe the more stars you eat. + + align:start position:0% +>> Weird. Or maybe the more stars you eat. + + + align:start position:0% +>> Weird. Or maybe the more stars you eat. +>> And now it's all ice. + + align:start position:0% +>> And now it's all ice. + + + align:start position:0% +>> And now it's all ice. +>> Oh. + + align:start position:0% +>> Oh. + + + align:start position:0% +>> Oh. +>> Oh, yes. Because she was getting happier + + align:start position:0% +>> Oh, yes. Because she was getting happier + + + align:start position:0% +>> Oh, yes. Because she was getting happier +when I bounced the ball. I guess she + + align:start position:0% +when I bounced the ball. I guess she + + + align:start position:0% +when I bounced the ball. I guess she +doesn't get cold. + + align:start position:0% +doesn't get cold. + + + align:start position:0% +doesn't get cold. +>> Oh my god. + + align:start position:0% +>> Oh my god. + + + align:start position:0% +>> Oh my god. +>> Oh no. + + align:start position:0% +>> Oh no. + + + align:start position:0% +>> Oh no. +>> Oh, it's blocking the um + + align:start position:0% +>> Oh, it's blocking the um + + + align:start position:0% +>> Oh, it's blocking the um +>> There's fire though. + + align:start position:0% +>> There's fire though. + + + align:start position:0% +>> There's fire though. +>> I think it maybe push the stars into the + + align:start position:0% +>> I think it maybe push the stars into the + + + align:start position:0% +>> I think it maybe push the stars into the +fire so that they melt or something. + + align:start position:0% +fire so that they melt or something. + + + align:start position:0% +fire so that they melt or something. +>> Arrow pointing. + + align:start position:0% +>> Arrow pointing. + + + align:start position:0% +>> Arrow pointing. +>> Oh, now it's a star. + + align:start position:0% +>> Oh, now it's a star. + + + align:start position:0% +>> Oh, now it's a star. +>> Interesting. + + align:start position:0% +>> Interesting. + + + align:start position:0% +>> Interesting. +>> Well, there's been a star there the + + align:start position:0% +>> Well, there's been a star there the + + + align:start position:0% +>> Well, there's been a star there the +entire time. + + align:start position:0% +entire time. + + + align:start position:0% +entire time. +>> What? + + align:start position:0% +>> What? + + + align:start position:0% +>> What? +All right, go push. Start with + + align:start position:0% +All right, go push. Start with + + + align:start position:0% +All right, go push. Start with +>> Oh, I see you have a hammer. + + align:start position:0% +>> Oh, I see you have a hammer. + + + align:start position:0% +>> Oh, I see you have a hammer. +>> Yeah. + + align:start position:0% +>> Yeah. + + + align:start position:0% +>> Yeah. +>> Yeah, you're dead. + + align:start position:0% + + + + align:start position:0% + +>> It's cuz you're on fire. + + align:start position:0% +>> It's cuz you're on fire. + + + align:start position:0% +>> It's cuz you're on fire. +>> The numbers on the stars are all + + align:start position:0% +>> The numbers on the stars are all + + + align:start position:0% +>> The numbers on the stars are all +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +>> the ball can't get to you. It says that. + + align:start position:0% +>> the ball can't get to you. It says that. + + + align:start position:0% +>> the ball can't get to you. It says that. +>> But now I can probably what? + + align:start position:0% +>> But now I can probably what? + + + align:start position:0% +>> But now I can probably what? +>> Push the ice into the fire. And the um + + align:start position:0% +>> Push the ice into the fire. And the um + + + align:start position:0% +>> Push the ice into the fire. And the um +the number on the top goes up every time + + align:start position:0% +the number on the top goes up every time + + + align:start position:0% +the number on the top goes up every time +you Yeah. The numbers on the star + + align:start position:0% +you Yeah. The numbers on the star + + + align:start position:0% +you Yeah. The numbers on the star +correspond to how many like + + align:start position:0% +correspond to how many like + + + align:start position:0% +correspond to how many like +>> you get + + align:start position:0% +>> you get + + + align:start position:0% +>> you get +>> being on fire seems like it would be + + align:start position:0% +>> being on fire seems like it would be + + + align:start position:0% +>> being on fire seems like it would be +bad. + + align:start position:0% + + + + align:start position:0% + +>> A + + align:start position:0% +>> A + + + align:start position:0% +>> A +[Music] + + align:start position:0% + + + + align:start position:0% + +tried to get rid of the ice. Can we put + + align:start position:0% +tried to get rid of the ice. Can we put + + + align:start position:0% +tried to get rid of the ice. Can we put +the lid? Okay. + + align:start position:0% +the lid? Okay. + + + align:start position:0% +the lid? Okay. +Wait, she doesn't want to play. + + align:start position:0% +Wait, she doesn't want to play. + + + align:start position:0% +Wait, she doesn't want to play. +>> That's because I got rid of the ice and + + align:start position:0% +>> That's because I got rid of the ice and + + + align:start position:0% +>> That's because I got rid of the ice and +he was happy, I think. + + align:start position:0% +he was happy, I think. + + + align:start position:0% +he was happy, I think. +>> Oh, it's getting icy, though. + + align:start position:0% +>> Oh, it's getting icy, though. + + + align:start position:0% +>> Oh, it's getting icy, though. +It's getting colder. + + align:start position:0% +It's getting colder. + + + align:start position:0% +It's getting colder. +>> There's no more stars to recharge my + + align:start position:0% +>> There's no more stars to recharge my + + + align:start position:0% +>> There's no more stars to recharge my +thing, though. + + align:start position:0% +thing, though. + + + align:start position:0% +thing, though. +>> I think you just have to go hard. This + + align:start position:0% +>> I think you just have to go hard. This + + + align:start position:0% +>> I think you just have to go hard. This +is where you were last time, I think. + + align:start position:0% +is where you were last time, I think. + + + align:start position:0% +is where you were last time, I think. +Yeah, there. + + align:start position:0% +Yeah, there. + + + align:start position:0% +Yeah, there. +>> Get the star. + + align:start position:0% + + + + align:start position:0% + +Oh no, no. + + align:start position:0% + + + + align:start position:0% + +It's really + + align:start position:0% + + + + align:start position:0% + +you get this too fast and your hair is + + align:start position:0% +you get this too fast and your hair is + + + align:start position:0% +you get this too fast and your hair is +burning. That means you're just getting + + align:start position:0% +burning. That means you're just getting + + + align:start position:0% +burning. That means you're just getting +too much love and it like starts falling + + align:start position:0% +too much love and it like starts falling + + + align:start position:0% +too much love and it like starts falling +really fast. + + align:start position:0% +really fast. + + + align:start position:0% +really fast. +>> Oh no. + + align:start position:0% +>> Oh no. + + + align:start position:0% +>> Oh no. +>> Oh no. Oh, no. + + align:start position:0% +>> Oh no. Oh, no. + + + align:start position:0% +>> Oh no. Oh, no. +>> But there's a there's a there's a + + align:start position:0% +>> But there's a there's a there's a + + + align:start position:0% +>> But there's a there's a there's a +counter on the ice blocks of the stars, + + align:start position:0% +counter on the ice blocks of the stars, + + + align:start position:0% +counter on the ice blocks of the stars, +and you get more points if you get them + + align:start position:0% +and you get more points if you get them + + + align:start position:0% +and you get more points if you get them +into the furnace faster. + + align:start position:0% +into the furnace faster. + + + align:start position:0% +into the furnace faster. +>> I think they went down when he started + + align:start position:0% +>> I think they went down when he started + + + align:start position:0% +>> I think they went down when he started +warming up in the furnace. So, the + + align:start position:0% +warming up in the furnace. So, the + + + align:start position:0% +warming up in the furnace. So, the +warmer the world is less points you get + + align:start position:0% +warmer the world is less points you get + + + align:start position:0% +warmer the world is less points you get +for the icing. Is this about global + + align:start position:0% +for the icing. Is this about global + + + align:start position:0% +for the icing. Is this about global +warming? + + align:start position:0% + + + + align:start position:0% + +>> Okay, so this + + align:start position:0% +>> Okay, so this + + + align:start position:0% +>> Okay, so this +>> I think it's about drugs. He gets love + + align:start position:0% +>> I think it's about drugs. He gets love + + + align:start position:0% +>> I think it's about drugs. He gets love +from this girl and then like I think + + align:start position:0% +from this girl and then like I think + + + align:start position:0% +from this girl and then like I think +make him happy, but only for a little + + align:start position:0% +make him happy, but only for a little + + + align:start position:0% +make him happy, but only for a little +bit. + + align:start position:0% +bit. + + + align:start position:0% +bit. +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +Yeah. + + align:start position:0% +Yeah. + + + align:start position:0% +Yeah. +>> What? + + align:start position:0% +>> What? + + + align:start position:0% +>> What? +>> Yeah. + + align:start position:0% +>> Yeah. + + + align:start position:0% +>> Yeah. +Yeah. + + align:start position:0% +Yeah. + + + align:start position:0% +Yeah. +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +>> So, if I'm on fire, it seems to reduce + + align:start position:0% +>> So, if I'm on fire, it seems to reduce + + + align:start position:0% +>> So, if I'm on fire, it seems to reduce +at a much faster rate. + + align:start position:0% +at a much faster rate. + + + align:start position:0% +at a much faster rate. +[Music] + + align:start position:0% + + + + align:start position:0% + +should avoid burning by not eating too + + align:start position:0% +should avoid burning by not eating too + + + align:start position:0% +should avoid burning by not eating too +many stars at a time. + + align:start position:0% +many stars at a time. + + + align:start position:0% +many stars at a time. +>> Just hit all + + align:start position:0% +>> Just hit all + + + align:start position:0% +>> Just hit all +>> everything is about drugs. + + align:start position:0% +>> everything is about drugs. + + + align:start position:0% +>> everything is about drugs. +>> I think everything's about drugs. + + align:start position:0% +>> I think everything's about drugs. + + + align:start position:0% +>> I think everything's about drugs. +>> I mean, yeah, obviously I'm crazy. + + align:start position:0% + + + + align:start position:0% + +>> You can actually catch a triple dragon + + align:start position:0% +>> You can actually catch a triple dragon + + + align:start position:0% +>> You can actually catch a triple dragon +in that case. + + align:start position:0% +in that case. + + + align:start position:0% +in that case. +>> Oh no. + + align:start position:0% +>> Oh no. + + + align:start position:0% +>> Oh no. +Uh two. + + align:start position:0% +Uh two. + + + align:start position:0% +Uh two. +>> Oh no. + + align:start position:0% +>> Oh no. + + + align:start position:0% +>> Oh no. +>> Really stupid design. Go all the way + + align:start position:0% +>> Really stupid design. Go all the way + + + align:start position:0% +>> Really stupid design. Go all the way +back down. + + align:start position:0% +back down. + + + align:start position:0% +back down. +>> There's a column on the right. You can + + align:start position:0% +>> There's a column on the right. You can + + + align:start position:0% +>> There's a column on the right. You can +fall fast. + + align:start position:0% +fall fast. + + + align:start position:0% +fall fast. +>> Oh, really? + + align:start position:0% +>> Oh, really? + + + align:start position:0% +>> Oh, really? +>> Yeah. + + align:start position:0% +>> Yeah. + + + align:start position:0% +>> Yeah. +>> The high you climb the further fall. + + align:start position:0% +>> The high you climb the further fall. + + + align:start position:0% +>> The high you climb the further fall. +>> Poetic. + + align:start position:0% +>> Poetic. + + + align:start position:0% +>> Poetic. +>> Now I probably don't have any stars. So + + align:start position:0% +>> Now I probably don't have any stars. So + + + align:start position:0% +>> Now I probably don't have any stars. So +I think we need to play + + align:start position:0% +I think we need to play + + + align:start position:0% +I think we need to play +>> Oh, she's gone. She's dead. + + align:start position:0% +>> Oh, she's gone. She's dead. + + + align:start position:0% +>> Oh, she's gone. She's dead. +>> You killed her. + + align:start position:0% +>> You killed her. + + + align:start position:0% +>> You killed her. +>> That's too sad. And there's not much + + align:start position:0% +>> That's too sad. And there's not much + + + align:start position:0% +>> That's too sad. And there's not much +fire left. + + align:start position:0% +fire left. + + + align:start position:0% +fire left. +>> Oh no. And the fire isn't bringing + + align:start position:0% +>> Oh no. And the fire isn't bringing + + + align:start position:0% +>> Oh no. And the fire isn't bringing +things back. + + align:start position:0% +things back. + + + align:start position:0% +things back. +>> Oh my god. You didn't get any stars + + align:start position:0% +>> Oh my god. You didn't get any stars + + + align:start position:0% +>> Oh my god. You didn't get any stars +first, so she died. + + align:start position:0% +first, so she died. + + + align:start position:0% +first, so she died. +>> Oh, + + align:start position:0% +>> Oh, + + + align:start position:0% +>> Oh, +>> she eats stars. + + align:start position:0% +>> she eats stars. + + + align:start position:0% +>> she eats stars. +>> Oh, there you go. + + align:start position:0% +>> Oh, there you go. + + + align:start position:0% +>> Oh, there you go. +>> There you go. Oh, is she there now? The + + align:start position:0% +>> There you go. Oh, is she there now? The + + + align:start position:0% +>> There you go. Oh, is she there now? The +fire started warming you again. + + align:start position:0% +fire started warming you again. + + + align:start position:0% +fire started warming you again. +>> Therapy. + + align:start position:0% +>> Therapy. + + + align:start position:0% +>> Therapy. +No. + + align:start position:0% +No. + + + align:start position:0% +No. +>> No, she's gone forever. + + align:start position:0% +>> No, she's gone forever. + + + align:start position:0% +>> No, she's gone forever. +>> You can't play ball alone. + + align:start position:0% +>> You can't play ball alone. + + + align:start position:0% +>> You can't play ball alone. +>> Well, she's going Oh, you're going to + + align:start position:0% +>> Well, she's going Oh, you're going to + + + align:start position:0% +>> Well, she's going Oh, you're going to +go. + + align:start position:0% +go. + + + align:start position:0% +go. +>> Maybe she only comes in the spring. + + align:start position:0% +>> Maybe she only comes in the spring. + + + align:start position:0% +>> Maybe she only comes in the spring. +Maybe winter's too cold. So maybe if I + + align:start position:0% +Maybe winter's too cold. So maybe if I + + + align:start position:0% +Maybe winter's too cold. So maybe if I +wait by the fire. + + align:start position:0% +wait by the fire. + + + align:start position:0% +wait by the fire. +>> Does it go faster? + + align:start position:0% + + + + align:start position:0% + +>> Yeah. What? Why is it getting bigger? + + align:start position:0% +>> Yeah. What? Why is it getting bigger? + + + align:start position:0% +>> Yeah. What? Why is it getting bigger? +>> Cuz he's by the fire. It's getting + + align:start position:0% +>> Cuz he's by the fire. It's getting + + + align:start position:0% +>> Cuz he's by the fire. It's getting +warmer. But that wasn't working earlier. + + align:start position:0% +warmer. But that wasn't working earlier. + + + align:start position:0% +warmer. But that wasn't working earlier. +>> Now it is. + + align:start position:0% +>> Now it is. + + + align:start position:0% +>> Now it is. +>> Go faster. + + align:start position:0% +>> Go faster. + + + align:start position:0% +>> Go faster. +>> He's a rock bottom. It's like spring. + + align:start position:0% +>> He's a rock bottom. It's like spring. + + + align:start position:0% +>> He's a rock bottom. It's like spring. +>> But + + align:start position:0% +>> But + + + align:start position:0% +>> But +she How high can you jump right now? + + align:start position:0% +she How high can you jump right now? + + + align:start position:0% +she How high can you jump right now? +>> Can you hit the ball? + + align:start position:0% +>> Can you hit the ball? + + + align:start position:0% +>> Can you hit the ball? +>> Pretty high. That's a lot of jumps. + + align:start position:0% +>> Pretty high. That's a lot of jumps. + + + align:start position:0% +>> Pretty high. That's a lot of jumps. +>> No, I can't hit the ball. + + align:start position:0% +>> No, I can't hit the ball. + + + align:start position:0% +>> No, I can't hit the ball. +>> Only she can lift the ball. + + align:start position:0% +>> Only she can lift the ball. + + + align:start position:0% +>> Only she can lift the ball. +>> Well, while you're increasing, you + + align:start position:0% +>> Well, while you're increasing, you + + + align:start position:0% +>> Well, while you're increasing, you +should probably go up and get the stars. + + align:start position:0% +should probably go up and get the stars. + + + align:start position:0% +should probably go up and get the stars. +>> Go up. Go up. + + align:start position:0% +>> Go up. Go up. + + + align:start position:0% +>> Go up. Go up. +>> There we go. + + align:start position:0% +>> There we go. + + + align:start position:0% +>> There we go. +>> Stop expanding. + + align:start position:0% +>> Stop expanding. + + + align:start position:0% +>> Stop expanding. +>> Isn't it Is it the stars? + + align:start position:0% +>> Isn't it Is it the stars? + + + align:start position:0% +>> Isn't it Is it the stars? +>> Stop contracting, too. + + align:start position:0% +>> Stop contracting, too. + + + align:start position:0% +>> Stop contracting, too. +>> Oh, you're even on fire now. + + align:start position:0% +>> Oh, you're even on fire now. + + + align:start position:0% +>> Oh, you're even on fire now. +>> He's on fire. + + align:start position:0% +>> He's on fire. + + + align:start position:0% +>> He's on fire. +>> Can you go infinitely high if you're on + + align:start position:0% +>> Can you go infinitely high if you're on + + + align:start position:0% +>> Can you go infinitely high if you're on +fire? + + align:start position:0% + + + + align:start position:0% + +>> Pretty darn high. That was like pretty. + + align:start position:0% +>> Pretty darn high. That was like pretty. + + + align:start position:0% +>> Pretty darn high. That was like pretty. +Uhoh. + + align:start position:0% +Uhoh. + + + align:start position:0% +Uhoh. +>> Four stars. + + align:start position:0% +>> Four stars. + + + align:start position:0% +>> Four stars. +>> Are you getting all of them? Oh, I Oh, + + align:start position:0% +>> Are you getting all of them? Oh, I Oh, + + + align:start position:0% +>> Are you getting all of them? Oh, I Oh, +>> that might have been a bit of an + + align:start position:0% +>> that might have been a bit of an + + + align:start position:0% +>> that might have been a bit of an +overdose. + + align:start position:0% +overdose. + + + align:start position:0% +overdose. +>> No. + + align:start position:0% +>> No. + + + align:start position:0% +>> No. +>> Yeah, you totally ODed on stars just + + align:start position:0% +>> Yeah, you totally ODed on stars just + + + align:start position:0% +>> Yeah, you totally ODed on stars just +there + + align:start position:0% +there + + + align:start position:0% +there +>> cuz you can always get stars as you go + + align:start position:0% +>> cuz you can always get stars as you go + + + align:start position:0% +>> cuz you can always get stars as you go +back. + + align:start position:0% +back. + + + align:start position:0% +back. +>> Or you can only hold four and then it + + align:start position:0% +>> Or you can only hold four and then it + + + align:start position:0% +>> Or you can only hold four and then it +retracts when you get four and then it + + align:start position:0% +retracts when you get four and then it + + + align:start position:0% +retracts when you get four and then it +turns ice blocks. + + align:start position:0% +turns ice blocks. + + + align:start position:0% +turns ice blocks. +>> What? + + align:start position:0% +>> What? + + + align:start position:0% +>> What? +>> That was intense. + + align:start position:0% + + + + align:start position:0% + +>> They're worth so much. + + align:start position:0% +>> They're worth so much. + + + align:start position:0% +>> They're worth so much. +Wait, + + align:start position:0% +Wait, + + + align:start position:0% +Wait, +>> and + + align:start position:0% +>> and + + + align:start position:0% +>> and +when + + align:start position:0% + + + + align:start position:0% + +>> you won, + + align:start position:0% +>> you won, + + + align:start position:0% +>> you won, +>> y + + align:start position:0% +>> y + + + align:start position:0% +>> y +>> what you want is a good question. + + align:start position:0% +>> what you want is a good question. + + + align:start position:0% +>> what you want is a good question. +>> That's gravitation. And actually, I + + align:start position:0% +>> That's gravitation. And actually, I + + + align:start position:0% +>> That's gravitation. And actually, I +mean, I'm not even kidding. That's + + align:start position:0% +mean, I'm not even kidding. That's + + + align:start position:0% +mean, I'm not even kidding. That's +that's certainly my favorite Jason game. + + align:start position:0% +that's certainly my favorite Jason game. + + + align:start position:0% +that's certainly my favorite Jason game. +It's it's one of + + align:start position:0% +It's it's one of + + + align:start position:0% +It's it's one of +>> it's one of my favorite games. And and I + + align:start position:0% +>> it's one of my favorite games. And and I + + + align:start position:0% +>> it's one of my favorite games. And and I +think even just the example of you guys + + align:start position:0% +think even just the example of you guys + + + align:start position:0% +think even just the example of you guys +playing is great, right? because because + + align:start position:0% +playing is great, right? because because + + + align:start position:0% +playing is great, right? because because +you're just kind of shouting out all + + align:start position:0% +you're just kind of shouting out all + + + align:start position:0% +you're just kind of shouting out all +these different ideas for what it could + + align:start position:0% +these different ideas for what it could + + + align:start position:0% +these different ideas for what it could +be about. Um and um you know there's + + align:start position:0% +be about. Um and um you know there's + + + align:start position:0% +be about. Um and um you know there's +some clear intentionality in in in his + + align:start position:0% +some clear intentionality in in in his + + + align:start position:0% +some clear intentionality in in in his +uh in his design um with this game, + + align:start position:0% +uh in his design um with this game, + + + align:start position:0% +uh in his design um with this game, +right? In terms of the systems trying to + + align:start position:0% +right? In terms of the systems trying to + + + align:start position:0% +right? In terms of the systems trying to +communicate something that's other than + + align:start position:0% +communicate something that's other than + + + align:start position:0% +communicate something that's other than +just, you know, engagement um or or I + + align:start position:0% +just, you know, engagement um or or I + + + align:start position:0% +just, you know, engagement um or or I +don't know, God, fun. Um I was it fun? + + align:start position:0% +don't know, God, fun. Um I was it fun? + + + align:start position:0% +don't know, God, fun. Um I was it fun? +>> Yeah. Oh, all right. Cool. Um yeah, + + align:start position:0% +>> Yeah. Oh, all right. Cool. Um yeah, + + + align:start position:0% +>> Yeah. Oh, all right. Cool. Um yeah, +that's pretty good. Um thoughts on what + + align:start position:0% +that's pretty good. Um thoughts on what + + + align:start position:0% +that's pretty good. Um thoughts on what +it's about? I heard a couple people be + + align:start position:0% +it's about? I heard a couple people be + + + align:start position:0% +it's about? I heard a couple people be +like drugs. + + align:start position:0% +like drugs. + + + align:start position:0% +like drugs. +>> Definitely drugs. + + align:start position:0% +>> Definitely drugs. + + + align:start position:0% +>> Definitely drugs. +>> Definitely drugs. + + align:start position:0% +>> Definitely drugs. + + + align:start position:0% +>> Definitely drugs. +>> Tons of analogies. Yeah. + + align:start position:0% +>> Tons of analogies. Yeah. + + + align:start position:0% +>> Tons of analogies. Yeah. +>> Yeah. It's kind of like drugs. + + align:start position:0% +>> Yeah. It's kind of like drugs. + + + align:start position:0% +>> Yeah. It's kind of like drugs. +>> Well, look, + + align:start position:0% +>> Well, look, + + + align:start position:0% +>> Well, look, +>> love is a relationship versus like + + align:start position:0% +>> love is a relationship versus like + + + align:start position:0% +>> love is a relationship versus like +whatever you're trying to do, your + + align:start position:0% +whatever you're trying to do, your + + + align:start position:0% +whatever you're trying to do, your +career, your + + align:start position:0% +career, your + + + align:start position:0% +career, your +>> Yeah. + + align:start position:0% +>> Yeah. + + + align:start position:0% +>> Yeah. +>> Yeah. I actually I call this like in + + align:start position:0% +>> Yeah. I actually I call this like in + + + align:start position:0% +>> Yeah. I actually I call this like in +life. + + align:start position:0% +life. + + + align:start position:0% +life. +>> I think it's like the ultimate MIT game. + + align:start position:0% +>> I think it's like the ultimate MIT game. + + + align:start position:0% +>> I think it's like the ultimate MIT game. +Um if I uh if I uh told you that this + + align:start position:0% +Um if I uh if I uh told you that this + + + align:start position:0% +Um if I uh if I uh told you that this +was his daughter, + + align:start position:0% +was his daughter, + + + align:start position:0% +was his daughter, +>> um would it change your interpretations + + align:start position:0% +>> um would it change your interpretations + + + align:start position:0% +>> um would it change your interpretations +of of the game and what happened? + + align:start position:0% +of of the game and what happened? + + + align:start position:0% +of of the game and what happened? +>> Yeah. So, so, so now if you know that + + align:start position:0% +>> Yeah. So, so, so now if you know that + + + align:start position:0% +>> Yeah. So, so, so now if you know that +this is his daughter, what do you think + + align:start position:0% +this is his daughter, what do you think + + + align:start position:0% +this is his daughter, what do you think +it's about? + + align:start position:0% +it's about? + + + align:start position:0% +it's about? +>> His job, + + align:start position:0% +>> His job, + + + align:start position:0% +>> His job, +>> neglect, + + align:start position:0% +>> neglect, + + + align:start position:0% +>> neglect, +>> work, neglect, job versus family, right? + + align:start position:0% +>> work, neglect, job versus family, right? + + + align:start position:0% +>> work, neglect, job versus family, right? +You know, he kind of + + align:start position:0% +You know, he kind of + + + align:start position:0% +You know, he kind of +>> um he says he says explicitly like + + align:start position:0% +>> um he says he says explicitly like + + + align:start position:0% +>> um he says he says explicitly like +before you played that this is a game + + align:start position:0% +before you played that this is a game + + + align:start position:0% +before you played that this is a game +about motivation. Um and he doesn't go + + align:start position:0% +about motivation. Um and he doesn't go + + + align:start position:0% +about motivation. Um and he doesn't go +doesn't go too far into telling you what + + align:start position:0% +doesn't go too far into telling you what + + + align:start position:0% +doesn't go too far into telling you what +the game is specifically about. And I + + align:start position:0% +the game is specifically about. And I + + + align:start position:0% +the game is specifically about. And I +think playing through it a couple times, + + align:start position:0% +think playing through it a couple times, + + + align:start position:0% +think playing through it a couple times, +but I mean I will tell you the first + + align:start position:0% +but I mean I will tell you the first + + + align:start position:0% +but I mean I will tell you the first +time I played and I came back out and + + align:start position:0% +time I played and I came back out and + + + align:start position:0% +time I played and I came back out and +she was gone, it was very upsetting for + + align:start position:0% +she was gone, it was very upsetting for + + + align:start position:0% +she was gone, it was very upsetting for +me. I was like, you know, and I don't + + align:start position:0% +me. I was like, you know, and I don't + + + align:start position:0% +me. I was like, you know, and I don't +know if it's just, you know, just, you + + align:start position:0% +know if it's just, you know, just, you + + + align:start position:0% +know if it's just, you know, just, you +know, I was, you know, ready to play it + + align:start position:0% +know, I was, you know, ready to play it + + + align:start position:0% +know, I was, you know, ready to play it +that way or my life stage or something + + align:start position:0% +that way or my life stage or something + + + align:start position:0% +that way or my life stage or something +like that. But the the idea of, you + + align:start position:0% +like that. But the the idea of, you + + + align:start position:0% +like that. But the the idea of, you +know, he's he's playing with his + + align:start position:0% +know, he's he's playing with his + + + align:start position:0% +know, he's he's playing with his +daughter that inspires him. You know, he + + align:start position:0% +daughter that inspires him. You know, he + + + align:start position:0% +daughter that inspires him. You know, he +travels and then, you know, one of these + + align:start position:0% +travels and then, you know, one of these + + + align:start position:0% +travels and then, you know, one of these +days if you're gone too long, she grows + + align:start position:0% +days if you're gone too long, she grows + + + align:start position:0% +days if you're gone too long, she grows +up. I mean, I don't know if she dies, + + align:start position:0% +up. I mean, I don't know if she dies, + + + align:start position:0% +up. I mean, I don't know if she dies, +but but you know, + + align:start position:0% +but but you know, + + + align:start position:0% +but but you know, +>> you didn't bring her any money, + + align:start position:0% +>> you didn't bring her any money, + + + align:start position:0% +>> you didn't bring her any money, +>> right? She cuz she had no money. Yeah, + + align:start position:0% +>> right? She cuz she had no money. Yeah, + + + align:start position:0% +>> right? She cuz she had no money. Yeah, +>> she died. + + align:start position:0% +>> she died. + + + align:start position:0% +>> she died. +>> So, I think this is a really really game + + align:start position:0% +>> So, I think this is a really really game + + + align:start position:0% +>> So, I think this is a really really game +and a game about motivation. + + align:start position:0% +and a game about motivation. + + + align:start position:0% +and a game about motivation. +>> It is. Yeah. or she wish she owed you on + + align:start position:0% +>> It is. Yeah. or she wish she owed you on + + + align:start position:0% +>> It is. Yeah. or she wish she owed you on +drugs. + + align:start position:0% +drugs. + + + align:start position:0% +drugs. +>> So, it's free. If you just Google search + + align:start position:0% +>> So, it's free. If you just Google search + + + align:start position:0% +>> So, it's free. If you just Google search +gravitation Jason, you'll you'll find + + align:start position:0% +gravitation Jason, you'll you'll find + + + align:start position:0% +gravitation Jason, you'll you'll find +the links to it. You'll find his artist + + align:start position:0% +the links to it. You'll find his artist + + + align:start position:0% +the links to it. You'll find his artist +statement, which I think is really kind + + align:start position:0% +statement, which I think is really kind + + + align:start position:0% +statement, which I think is really kind +of good to read. Um, again, with John + + align:start position:0% +of good to read. Um, again, with John + + + align:start position:0% +of good to read. Um, again, with John +Sharp's kind of point about like, you + + align:start position:0% +Sharp's kind of point about like, you + + + align:start position:0% +Sharp's kind of point about like, you +know, declaring your intentionality, + + align:start position:0% +know, declaring your intentionality, + + + align:start position:0% +know, declaring your intentionality, +whether you say what the game's about is + + align:start position:0% +whether you say what the game's about is + + + align:start position:0% +whether you say what the game's about is +important. Um, again, I I think I think + + align:start position:0% +important. Um, again, I I think I think + + + align:start position:0% +important. Um, again, I I think I think +this qualifies, at least for me, as art. + + align:start position:0% +this qualifies, at least for me, as art. + + + align:start position:0% +this qualifies, at least for me, as art. +Um, it's doing things that that I see + + align:start position:0% +Um, it's doing things that that I see + + + align:start position:0% +Um, it's doing things that that I see +other pieces of art doing. Um, okay. So, + + align:start position:0% +other pieces of art doing. Um, okay. So, + + + align:start position:0% +other pieces of art doing. Um, okay. So, +Paulo Percini, how many of your time? + + align:start position:0% +Paulo Percini, how many of your time? + + + align:start position:0% +Paulo Percini, how many of your time? +Um, uh, Paulo Percini is is one of my + + align:start position:0% +Um, uh, Paulo Percini is is one of my + + + align:start position:0% +Um, uh, Paulo Percini is is one of my +favorite game designers right now, and + + align:start position:0% +favorite game designers right now, and + + + align:start position:0% +favorite game designers right now, and +this this game actually is is is one of + + align:start position:0% +this this game actually is is is one of + + + align:start position:0% +this this game actually is is is one of +his newest ones, and I think it's I + + align:start position:0% +his newest ones, and I think it's I + + + align:start position:0% +his newest ones, and I think it's I +think it's hilarious and great. Um, and + + align:start position:0% +think it's hilarious and great. Um, and + + + align:start position:0% +think it's hilarious and great. Um, and +it's called Memory Reloaded: The + + align:start position:0% +it's called Memory Reloaded: The + + + align:start position:0% +it's called Memory Reloaded: The +Downfall. Test your concentration with + + align:start position:0% +Downfall. Test your concentration with + + + align:start position:0% +Downfall. Test your concentration with +Memory Reloaded, a matching game for + + align:start position:0% +Memory Reloaded, a matching game for + + + align:start position:0% +Memory Reloaded, a matching game for +these unstable times. History may be + + align:start position:0% +these unstable times. History may be + + + align:start position:0% +these unstable times. History may be +different from that which you remember. + + align:start position:0% +different from that which you remember. + + + align:start position:0% +different from that which you remember. +And who would like to play Memory + + align:start position:0% +And who would like to play Memory + + + align:start position:0% +And who would like to play Memory +Reloaded? I'm laughing already because + + align:start position:0% +Reloaded? I'm laughing already because + + + align:start position:0% +Reloaded? I'm laughing already because +it's funny. Has anybody played it? I + + align:start position:0% +it's funny. Has anybody played it? I + + + align:start position:0% +it's funny. Has anybody played it? I +need someone who's not played it. Okay, + + align:start position:0% +need someone who's not played it. Okay, + + + align:start position:0% +need someone who's not played it. Okay, +good. Jeremy, you want to do it? + + align:start position:0% +good. Jeremy, you want to do it? + + + align:start position:0% +good. Jeremy, you want to do it? +>> Sure. + + align:start position:0% +>> Sure. + + + align:start position:0% +>> Sure. +>> Awesome. + + align:start position:0% + + + + align:start position:0% + +This presentation is so cool. + + align:start position:0% +This presentation is so cool. + + + align:start position:0% +This presentation is so cool. +>> Okay, you're up. + + align:start position:0% +>> Okay, you're up. + + + align:start position:0% +>> Okay, you're up. +>> I will click. + + align:start position:0% +>> I will click. + + + align:start position:0% +>> I will click. +>> Don't do it. + + align:start position:0% +>> Don't do it. + + + align:start position:0% +>> Don't do it. +>> Oh, you're out. + + align:start position:0% +>> Oh, you're out. + + + align:start position:0% +>> Oh, you're out. +>> You're done. You lost already. + + align:start position:0% +>> You're done. You lost already. + + + align:start position:0% +>> You're done. You lost already. +>> No way. That's kind of scary. All right. + + align:start position:0% +>> No way. That's kind of scary. All right. + + + align:start position:0% +>> No way. That's kind of scary. All right. +Oh, I can already see what they're going + + align:start position:0% +Oh, I can already see what they're going + + + align:start position:0% +Oh, I can already see what they're going +to do. They're You're going to play + + align:start position:0% +to do. They're You're going to play + + + align:start position:0% +to do. They're You're going to play +Switch on me. All right. Afghan freedom + + align:start position:0% +Switch on me. All right. Afghan freedom + + + align:start position:0% +Switch on me. All right. Afghan freedom +fighter. He's going to be a terrorist + + align:start position:0% +fighter. He's going to be a terrorist + + + align:start position:0% +fighter. He's going to be a terrorist +later. + + align:start position:0% +later. + + + align:start position:0% +later. +>> Migrant workforce. + + align:start position:0% +>> Migrant workforce. + + + align:start position:0% +>> Migrant workforce. +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +Life for the workforce. Yay. Nick. Yay. + + align:start position:0% +Life for the workforce. Yay. Nick. Yay. + + + align:start position:0% +Life for the workforce. Yay. Nick. Yay. +>> Iraqi oil. Afghan freedom fighter. + + align:start position:0% +>> Iraqi oil. Afghan freedom fighter. + + + align:start position:0% +>> Iraqi oil. Afghan freedom fighter. +>> I bet if you grab Iraqi oil before + + align:start position:0% +>> I bet if you grab Iraqi oil before + + + align:start position:0% +>> I bet if you grab Iraqi oil before +Afghan freedom fighter, he becomes a + + align:start position:0% +Afghan freedom fighter, he becomes a + + + align:start position:0% +Afghan freedom fighter, he becomes a +terrorist. + + align:start position:0% + + + + align:start position:0% + +>> Global inequality. Peace and + + align:start position:0% +>> Global inequality. Peace and + + + align:start position:0% +>> Global inequality. Peace and +>> global inequality. + + align:start position:0% +>> global inequality. + + + align:start position:0% +>> global inequality. +>> Global inequality. + + align:start position:0% +>> Global inequality. + + + align:start position:0% +>> Global inequality. +>> Global inequality. + + align:start position:0% +>> Global inequality. + + + align:start position:0% +>> Global inequality. +>> Yes. + + align:start position:0% +>> Yes. + + + align:start position:0% +>> Yes. +>> Yes. Global inequality. + + align:start position:0% +>> Yes. Global inequality. + + + align:start position:0% +>> Yes. Global inequality. +>> Yes. + + align:start position:0% +>> Yes. + + + align:start position:0% +>> Yes. +>> All right. + + align:start position:0% +>> All right. + + + align:start position:0% +>> All right. +I'm doing well. Ruthless maker + + align:start position:0% +I'm doing well. Ruthless maker + + + align:start position:0% +I'm doing well. Ruthless maker +>> loan chart. Rocky was Rocky here. + + align:start position:0% +>> loan chart. Rocky was Rocky here. + + + align:start position:0% +>> loan chart. Rocky was Rocky here. +[Music] + + align:start position:0% + + + + align:start position:0% + +>> Awkward. All right. Universal + + align:start position:0% +>> Awkward. All right. Universal + + + align:start position:0% +>> Awkward. All right. Universal +healthcare. Man-made global warming. + + align:start position:0% +healthcare. Man-made global warming. + + + align:start position:0% +healthcare. Man-made global warming. +>> Man-made natural. + + align:start position:0% + + + + align:start position:0% + +>> Hey, not cool. Universal healthcare. + + align:start position:0% +>> Hey, not cool. Universal healthcare. + + + align:start position:0% +>> Hey, not cool. Universal healthcare. +>> Universal healthcare. Sweet. + + align:start position:0% +>> Universal healthcare. Sweet. + + + align:start position:0% +>> Universal healthcare. Sweet. +>> Oh, + + align:start position:0% +>> Oh, + + + align:start position:0% +>> Oh, +one over there. + + align:start position:0% +one over there. + + + align:start position:0% +one over there. +>> Yeah. + + align:start position:0% +>> Yeah. + + + align:start position:0% +>> Yeah. +Nice. Hooray. Right under Valentine. + + align:start position:0% +Nice. Hooray. Right under Valentine. + + + align:start position:0% +Nice. Hooray. Right under Valentine. +>> Well, natural. Come on. + + align:start position:0% +>> Well, natural. Come on. + + + align:start position:0% +>> Well, natural. Come on. +>> Wait. What? + + align:start position:0% +>> Wait. What? + + + align:start position:0% +>> Wait. What? +>> Why? Needy maker. Ruthless maker. + + align:start position:0% +>> Why? Needy maker. Ruthless maker. + + + align:start position:0% +>> Why? Needy maker. Ruthless maker. +>> Oh, that's the order. You click them in. + + align:start position:0% +>> Oh, that's the order. You click them in. + + + align:start position:0% +>> Oh, that's the order. You click them in. +>> Ruthless maker. What? + + align:start position:0% +>> Ruthless maker. What? + + + align:start position:0% +>> Ruthless maker. What? +>> What? What are the other ones now? + + align:start position:0% +>> What? What are the other ones now? + + + align:start position:0% +>> What? What are the other ones now? +>> Yeah. + + align:start position:0% +>> Yeah. + + + align:start position:0% +>> Yeah. +>> Oh, there we go. + + align:start position:0% +>> Oh, there we go. + + + align:start position:0% +>> Oh, there we go. +>> Nice. + + align:start position:0% +>> Nice. + + + align:start position:0% +>> Nice. +>> So, that means now let's see. + + align:start position:0% +>> So, that means now let's see. + + + align:start position:0% +>> So, that means now let's see. +Hey. He's never a satisfied baker. + + align:start position:0% +Hey. He's never a satisfied baker. + + + align:start position:0% +Hey. He's never a satisfied baker. +>> Where? + + align:start position:0% +>> Where? + + + align:start position:0% +>> Where? +>> What the hell? + + align:start position:0% +>> What the hell? + + + align:start position:0% +>> What the hell? +>> Oh dear. Did we shoot + + align:start position:0% +>> Oh dear. Did we shoot + + + align:start position:0% +>> Oh dear. Did we shoot +>> better move? + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +>> Oh, I get it. + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +That's fine. Is it the entire game? + + align:start position:0% +That's fine. Is it the entire game? + + + align:start position:0% +That's fine. Is it the entire game? +>> Yes, that that is the the whole game. Of + + align:start position:0% +>> Yes, that that is the the whole game. Of + + + align:start position:0% +>> Yes, that that is the the whole game. Of +course, you can get different outcomes, + + align:start position:0% +course, you can get different outcomes, + + + align:start position:0% +course, you can get different outcomes, +but uh but yeah, that's the idea. Um + + align:start position:0% +but uh but yeah, that's the idea. Um + + + align:start position:0% +but uh but yeah, that's the idea. Um +>> so I think you guys have seen some of uh + + align:start position:0% +>> so I think you guys have seen some of uh + + + align:start position:0% +>> so I think you guys have seen some of uh +some of Mullet Mysteria's other work + + align:start position:0% +some of Mullet Mysteria's other work + + + align:start position:0% +some of Mullet Mysteria's other work +that you guys saw every day the same + + align:start position:0% +that you guys saw every day the same + + + align:start position:0% +that you guys saw every day the same +dream. I like that + + align:start position:0% +dream. I like that + + + align:start position:0% +dream. I like that +>> which is interesting. Um yeah, that that + + align:start position:0% +>> which is interesting. Um yeah, that that + + + align:start position:0% +>> which is interesting. Um yeah, that that +one's that one's also one of my favorite + + align:start position:0% +one's that one's also one of my favorite + + + align:start position:0% +one's that one's also one of my favorite +games. Um but this is, you know, this is + + align:start position:0% +games. Um but this is, you know, this is + + + align:start position:0% +games. Um but this is, you know, this is +kind of uh this is this is kind of + + align:start position:0% +kind of uh this is this is kind of + + + align:start position:0% +kind of uh this is this is kind of +looking at another kind of sector of + + align:start position:0% +looking at another kind of sector of + + + align:start position:0% +looking at another kind of sector of +art, right? The kind of activist + + align:start position:0% +art, right? The kind of activist + + + align:start position:0% +art, right? The kind of activist +political statement sector of art and + + align:start position:0% +political statement sector of art and + + + align:start position:0% +political statement sector of art and +doing that through games and and it's + + align:start position:0% +doing that through games and and it's + + + align:start position:0% +doing that through games and and it's +something that this music + + align:start position:0% +something that this music + + + align:start position:0% +something that this music +um something that um that he does + + align:start position:0% +um something that um that he does + + + align:start position:0% +um something that um that he does +particularly well with his games and I + + align:start position:0% +particularly well with his games and I + + + align:start position:0% +particularly well with his games and I +think this one's this one's particularly + + align:start position:0% +think this one's this one's particularly + + + align:start position:0% +think this one's this one's particularly +um interesting and kind of funny. I love + + align:start position:0% +um interesting and kind of funny. I love + + + align:start position:0% +um interesting and kind of funny. I love +I love the um + + align:start position:0% +I love the um + + + align:start position:0% +I love the um +the kind of reworking of a really + + align:start position:0% +the kind of reworking of a really + + + align:start position:0% +the kind of reworking of a really +classic game mechanic, right? Like + + align:start position:0% +classic game mechanic, right? Like + + + align:start position:0% +classic game mechanic, right? Like +memory the the entire point of memory is + + align:start position:0% +memory the the entire point of memory is + + + align:start position:0% +memory the the entire point of memory is +your expectation that they would be the + + align:start position:0% +your expectation that they would be the + + + align:start position:0% +your expectation that they would be the +same the second time you turn it over. + + align:start position:0% +same the second time you turn it over. + + + align:start position:0% +same the second time you turn it over. +And when it changes on you, it + + align:start position:0% +And when it changes on you, it + + + align:start position:0% +And when it changes on you, it +reinforces that kind of uh that kind of + + align:start position:0% +reinforces that kind of uh that kind of + + + align:start position:0% +reinforces that kind of uh that kind of +perspective uh I suppose imbalance um + + align:start position:0% +perspective uh I suppose imbalance um + + + align:start position:0% +perspective uh I suppose imbalance um +that can exist when you're not just + + align:start position:0% +that can exist when you're not just + + + align:start position:0% +that can exist when you're not just +turning over, you know, toad stools and + + align:start position:0% +turning over, you know, toad stools and + + + align:start position:0% +turning over, you know, toad stools and +and Bowsers, but you know, actual kind + + align:start position:0% +and Bowsers, but you know, actual kind + + + align:start position:0% +and Bowsers, but you know, actual kind +of interesting things. I really I love + + align:start position:0% +of interesting things. I really I love + + + align:start position:0% +of interesting things. I really I love +the the crying sweating polar bear um + + align:start position:0% +the the crying sweating polar bear um + + + align:start position:0% +the the crying sweating polar bear um +and and the well with like a beach chair + + align:start position:0% +and and the well with like a beach chair + + + align:start position:0% +and and the well with like a beach chair +actually cracks me down. Um and I think + + align:start position:0% +actually cracks me down. Um and I think + + + align:start position:0% +actually cracks me down. Um and I think +humor is actually something that + + align:start position:0% +humor is actually something that + + + align:start position:0% +humor is actually something that +shouldn't be ignored here, right? I + + align:start position:0% +shouldn't be ignored here, right? I + + + align:start position:0% +shouldn't be ignored here, right? I +mean, if we remember that was one of the + + align:start position:0% +mean, if we remember that was one of the + + + align:start position:0% +mean, if we remember that was one of the +kind of the central flux things, this + + align:start position:0% +kind of the central flux things, this + + + align:start position:0% +kind of the central flux things, this +idea of like satire, humor is important. + + align:start position:0% +idea of like satire, humor is important. + + + align:start position:0% +idea of like satire, humor is important. +Um and so, uh I really I I think + + align:start position:0% +Um and so, uh I really I I think + + + align:start position:0% +Um and so, uh I really I I think +Paulini's work is really awesome. And + + align:start position:0% +Paulini's work is really awesome. And + + + align:start position:0% +Paulini's work is really awesome. And +again, I for me it's certainly arc + + align:start position:0% +again, I for me it's certainly arc + + + align:start position:0% +again, I for me it's certainly arc +enough. Um this game is really cool. Uh + + align:start position:0% +enough. Um this game is really cool. Uh + + + align:start position:0% +enough. Um this game is really cool. Uh +who's played love? We have a few people + + align:start position:0% +who's played love? We have a few people + + + align:start position:0% +who's played love? We have a few people +that's played Love. All right, cool. Um + + align:start position:0% +that's played Love. All right, cool. Um + + + align:start position:0% +that's played Love. All right, cool. Um +I'd love someone who has not played Love + + align:start position:0% +I'd love someone who has not played Love + + + align:start position:0% +I'd love someone who has not played Love +to to play it for a little bit. I don't + + align:start position:0% +to to play it for a little bit. I don't + + + align:start position:0% +to to play it for a little bit. I don't +know if we can play the whole game. Um, + + align:start position:0% +know if we can play the whole game. Um, + + + align:start position:0% +know if we can play the whole game. Um, +but uh this is actually a game that I I + + align:start position:0% +but uh this is actually a game that I I + + + align:start position:0% +but uh this is actually a game that I I +really don't like. Um but I like the + + align:start position:0% +really don't like. Um but I like the + + + align:start position:0% +really don't like. Um but I like the +things that it does, if that makes any + + align:start position:0% +things that it does, if that makes any + + + align:start position:0% +things that it does, if that makes any +sense. Like I it bothers me for some + + align:start position:0% +sense. Like I it bothers me for some + + + align:start position:0% +sense. Like I it bothers me for some +reason. Um and yet + + align:start position:0% +reason. Um and yet + + + align:start position:0% +reason. Um and yet +it's such an articulate statement. This + + align:start position:0% +it's such an articulate statement. This + + + align:start position:0% +it's such an articulate statement. This +game bothers me. Um but + + align:start position:0% +game bothers me. Um but + + + align:start position:0% +game bothers me. Um but +>> but I think it's worth looking at + + align:start position:0% +>> but I think it's worth looking at + + + align:start position:0% +>> but I think it's worth looking at +because he's he's doing particularly + + align:start position:0% +because he's he's doing particularly + + + align:start position:0% +because he's he's doing particularly +interesting things. + + align:start position:0% +interesting things. + + + align:start position:0% +interesting things. +Alexander has oius. Aus + + align:start position:0% + + + + align:start position:0% + +top right. + + align:start position:0% +top right. + + + align:start position:0% +top right. +>> No, you are a girl. Okay. I'm a girl. + + align:start position:0% +>> No, you are a girl. Okay. I'm a girl. + + + align:start position:0% +>> No, you are a girl. Okay. I'm a girl. +[Music] + + align:start position:0% + + + + align:start position:0% + +If you say yes, will he like not teach + + align:start position:0% +If you say yes, will he like not teach + + + align:start position:0% +If you say yes, will he like not teach +you how to play? + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +>> Yeah. + + align:start position:0% + + + + align:start position:0% + +Don't touch the bones. + + align:start position:0% + + + + align:start position:0% + +It's like Sonic. + + align:start position:0% + + + + align:start position:0% + +>> What? + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +>> There's two paths. + + align:start position:0% +>> There's two paths. + + + align:start position:0% +>> There's two paths. +I best way of playing like this. + + align:start position:0% + + + + align:start position:0% + +>> Can you use that? That's what I was + + align:start position:0% +>> Can you use that? That's what I was + + + align:start position:0% +>> Can you use that? That's what I was +going to do. I make a mistake. + + align:start position:0% +going to do. I make a mistake. + + + align:start position:0% +going to do. I make a mistake. +>> Travel the lower. + + align:start position:0% + + + + align:start position:0% + +>> Wait, what's appearing? + + align:start position:0% + + + + align:start position:0% + +We need to slow down. + + align:start position:0% + + + + align:start position:0% + +I'm totally disabled. + + align:start position:0% +I'm totally disabled. + + + align:start position:0% +I'm totally disabled. +>> What? I can't hit the red blocks now. + + align:start position:0% +>> What? I can't hit the red blocks now. + + + align:start position:0% +>> What? I can't hit the red blocks now. +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +>> Disgusting. + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +>> This game is not only hard, it's also + + align:start position:0% +>> This game is not only hard, it's also + + + align:start position:0% +>> This game is not only hard, it's also +positive. + + align:start position:0% +positive. + + + align:start position:0% +positive. +This is our + + align:start position:0% +This is our + + + align:start position:0% +This is our +>> patience. + + align:start position:0% + + + + align:start position:0% + +Yay. + + align:start position:0% +Yay. + + + align:start position:0% +Yay. +>> Those are red. + + align:start position:0% +>> Those are red. + + + align:start position:0% +>> Those are red. +>> I know. That means I can't touch him. + + align:start position:0% +>> I know. That means I can't touch him. + + + align:start position:0% +>> I know. That means I can't touch him. +>> Yay. + + align:start position:0% +>> Yay. + + + align:start position:0% +>> Yay. +>> Don't do it. Don't do it, dude. + + align:start position:0% +>> Don't do it. Don't do it, dude. + + + align:start position:0% +>> Don't do it. Don't do it, dude. +>> Do it. + + align:start position:0% +>> Do it. + + + align:start position:0% +>> Do it. +>> Do it. + + align:start position:0% +>> Do it. + + + align:start position:0% +>> Do it. +>> Do it. + + align:start position:0% +>> Do it. + + + align:start position:0% +>> Do it. +>> Do it. + + align:start position:0% +>> Do it. + + + align:start position:0% +>> Do it. +>> You're just going to have to go back to + + align:start position:0% +>> You're just going to have to go back to + + + align:start position:0% +>> You're just going to have to go back to +the part that was just hard. + + align:start position:0% + + + + align:start position:0% + +See, + + align:start position:0% +See, + + + align:start position:0% +See, +there's no red blocks. You get red + + align:start position:0% +there's no red blocks. You get red + + + align:start position:0% +there's no red blocks. You get red +blocks when you disobey. + + align:start position:0% +blocks when you disobey. + + + align:start position:0% +blocks when you disobey. +>> Yeah. + + align:start position:0% +>> Yeah. + + + align:start position:0% +>> Yeah. +You still can't touch + + align:start position:0% +You still can't touch + + + align:start position:0% +You still can't touch +the yellow card. + + align:start position:0% +the yellow card. + + + align:start position:0% +the yellow card. +>> So, if you disobey, it hides from you + + align:start position:0% +>> So, if you disobey, it hides from you + + + align:start position:0% +>> So, if you disobey, it hides from you +what things actually are + + align:start position:0% + + + + align:start position:0% + +>> or or if you obey, they're getting + + align:start position:0% +>> or or if you obey, they're getting + + + align:start position:0% +>> or or if you obey, they're getting +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +It's so hard. So little buttons to + + align:start position:0% +It's so hard. So little buttons to + + + align:start position:0% +It's so hard. So little buttons to +press. + + align:start position:0% +press. + + + align:start position:0% +press. +>> Wait, what are the controls? + + align:start position:0% +>> Wait, what are the controls? + + + align:start position:0% +>> Wait, what are the controls? +>> The keys. + + align:start position:0% +>> The keys. + + + align:start position:0% +>> The keys. +>> Right, left. + + align:start position:0% +>> Right, left. + + + align:start position:0% +>> Right, left. +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +>> Should this have made + + align:start position:0% +>> Should this have made + + + align:start position:0% +>> Should this have made +>> What? Can you no longer jump? + + align:start position:0% +>> What? Can you no longer jump? + + + align:start position:0% +>> What? Can you no longer jump? +>> I was just screaming out. + + align:start position:0% +>> I was just screaming out. + + + align:start position:0% +>> I was just screaming out. +>> He's doing crouch. Crouch. + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +risky. Oh, I thought that was bad. + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +>> Yeah, but that kind of looks like you. + + align:start position:0% +>> Yeah, but that kind of looks like you. + + + align:start position:0% +>> Yeah, but that kind of looks like you. +>> This game is well aggravatingly tuned + + align:start position:0% +>> This game is well aggravatingly tuned + + + align:start position:0% +>> This game is well aggravatingly tuned +because it's like just build it up. + + align:start position:0% +because it's like just build it up. + + + align:start position:0% +because it's like just build it up. +>> Uh + + align:start position:0% + + + + align:start position:0% + +uh + + align:start position:0% +uh + + + align:start position:0% +uh +>> crouch crouch. + + align:start position:0% + + + + align:start position:0% + +>> Why you doing that professionally? I + + align:start position:0% +>> Why you doing that professionally? I + + + align:start position:0% +>> Why you doing that professionally? I +just like + + align:start position:0% + + + + align:start position:0% + +>> So, it's actually a pretty long game. Um + + align:start position:0% +>> So, it's actually a pretty long game. Um + + + align:start position:0% +>> So, it's actually a pretty long game. Um +I I encourage you guys to uh it's pretty + + align:start position:0% +I I encourage you guys to uh it's pretty + + + align:start position:0% +I I encourage you guys to uh it's pretty +it's all flashbased. + + align:start position:0% +it's all flashbased. + + + align:start position:0% +it's all flashbased. +>> What's the message? + + align:start position:0% +>> What's the message? + + + align:start position:0% +>> What's the message? +>> Uh that's a really good question. Let me + + align:start position:0% +>> Uh that's a really good question. Let me + + + align:start position:0% +>> Uh that's a really good question. Let me +uh let me just jump in and go back. + + align:start position:0% +uh let me just jump in and go back. + + + align:start position:0% +uh let me just jump in and go back. +>> Thank you for playing. + + align:start position:0% +>> Thank you for playing. + + + align:start position:0% +>> Thank you for playing. +>> Thank you for playing. + + align:start position:0% +>> Thank you for playing. + + + align:start position:0% +>> Thank you for playing. +>> Disgusting. + + align:start position:0% +>> Disgusting. + + + align:start position:0% +>> Disgusting. +>> You are a changed person because of it. + + align:start position:0% +>> You are a changed person because of it. + + + align:start position:0% +>> You are a changed person because of it. +>> Disgusting. + + align:start position:0% +>> Disgusting. + + + align:start position:0% +>> Disgusting. +>> So yeah. So the question then becomes + + align:start position:0% +>> So yeah. So the question then becomes + + + align:start position:0% +>> So yeah. So the question then becomes +what the point which you know already + + align:start position:0% +what the point which you know already + + + align:start position:0% +what the point which you know already +we're in a position now where we're + + align:start position:0% +we're in a position now where we're + + + align:start position:0% +we're in a position now where we're +asking questions like that which is you + + align:start position:0% +asking questions like that which is you + + + align:start position:0% +asking questions like that which is you +know if you were playing Modern Warfare + + align:start position:0% +know if you were playing Modern Warfare + + + align:start position:0% +know if you were playing Modern Warfare +2 you might say what's the point like + + align:start position:0% +2 you might say what's the point like + + + align:start position:0% +2 you might say what's the point like +would be to blow a lot of stuff up + + align:start position:0% +would be to blow a lot of stuff up + + + align:start position:0% +would be to blow a lot of stuff up +right? So um this is + + align:start position:0% +right? So um this is + + + align:start position:0% +right? So um this is +>> this is a response he had in one of his + + align:start position:0% +>> this is a response he had in one of his + + + align:start position:0% +>> this is a response he had in one of his +interviews he gave after it was + + align:start position:0% +interviews he gave after it was + + + align:start position:0% +interviews he gave after it was +released. He said, "I wanted to get + + align:start position:0% +released. He said, "I wanted to get + + + align:start position:0% +released. He said, "I wanted to get +people to wake up and think about the + + align:start position:0% +people to wake up and think about the + + + align:start position:0% +people to wake up and think about the +games they are playing. Much of the + + align:start position:0% +games they are playing. Much of the + + + align:start position:0% +games they are playing. Much of the +industry appears to be pushing in the + + align:start position:0% +industry appears to be pushing in the + + + align:start position:0% +industry appears to be pushing in the +opposite direction. Essay long + + align:start position:0% +opposite direction. Essay long + + + align:start position:0% +opposite direction. Essay long +tutorials, holding your hand from + + align:start position:0% +tutorials, holding your hand from + + + align:start position:0% +tutorials, holding your hand from +beginning to end in subtext, screamed + + align:start position:0% +beginning to end in subtext, screamed + + + align:start position:0% +beginning to end in subtext, screamed +through pointless exposition. It is + + align:start position:0% +through pointless exposition. It is + + + align:start position:0% +through pointless exposition. It is +treating players like idiots is + + align:start position:0% +treating players like idiots is + + + align:start position:0% +treating players like idiots is +absolutely infuriating." Um, when you + + align:start position:0% +absolutely infuriating." Um, when you + + + align:start position:0% +absolutely infuriating." Um, when you +think about it in terms of a tutorial, + + align:start position:0% +think about it in terms of a tutorial, + + + align:start position:0% +think about it in terms of a tutorial, +right, if this is the tutorial for + + align:start position:0% +right, if this is the tutorial for + + + align:start position:0% +right, if this is the tutorial for +playing the game, it's pretty obnoxious. + + align:start position:0% +playing the game, it's pretty obnoxious. + + + align:start position:0% +playing the game, it's pretty obnoxious. +Um, but it's not that much different + + align:start position:0% +Um, but it's not that much different + + + align:start position:0% +Um, but it's not that much different +than the kind of tutorials that we + + align:start position:0% +than the kind of tutorials that we + + + align:start position:0% +than the kind of tutorials that we +encounter in a lot of games, right? That + + align:start position:0% +encounter in a lot of games, right? That + + + align:start position:0% +encounter in a lot of games, right? That +just basically hold your hand and tell + + align:start position:0% +just basically hold your hand and tell + + + align:start position:0% +just basically hold your hand and tell +you how to do everything. Um, so I think + + align:start position:0% +you how to do everything. Um, so I think + + + align:start position:0% +you how to do everything. Um, so I think +he's really kind of confronting that. + + align:start position:0% +he's really kind of confronting that. + + + align:start position:0% +he's really kind of confronting that. +Um, I guess if I were to say the reasons + + align:start position:0% +Um, I guess if I were to say the reasons + + + align:start position:0% +Um, I guess if I were to say the reasons +that I don't like this game, uh, I think + + align:start position:0% +that I don't like this game, uh, I think + + + align:start position:0% +that I don't like this game, uh, I think +the control scheme is is actually it's a + + align:start position:0% +the control scheme is is actually it's a + + + align:start position:0% +the control scheme is is actually it's a +weakness. The game is so hard that I + + align:start position:0% +weakness. The game is so hard that I + + + align:start position:0% +weakness. The game is so hard that I +mean, you saw like, you know, you + + align:start position:0% +mean, you saw like, you know, you + + + align:start position:0% +mean, you saw like, you know, you +couldn't even get to the things that he + + align:start position:0% +couldn't even get to the things that he + + + align:start position:0% +couldn't even get to the things that he +was trying to communicate. It gets + + align:start position:0% +was trying to communicate. It gets + + + align:start position:0% +was trying to communicate. It gets +weirder the farther along you get. I can + + align:start position:0% +weirder the farther along you get. I can + + + align:start position:0% +weirder the farther along you get. I can +I can promise you it's just it's like + + align:start position:0% +I can promise you it's just it's like + + + align:start position:0% +I can promise you it's just it's like +you have to get really skilled at doing + + align:start position:0% +you have to get really skilled at doing + + + align:start position:0% +you have to get really skilled at doing +it. Um, so there's there's kind of like + + align:start position:0% +it. Um, so there's there's kind of like + + + align:start position:0% +it. Um, so there's there's kind of like +a play barrier for entry on it. Um uh + + align:start position:0% +a play barrier for entry on it. Um uh + + + align:start position:0% +a play barrier for entry on it. Um uh +it's also it also for me I think + + align:start position:0% +it's also it also for me I think + + + align:start position:0% +it's also it also for me I think +dare I say it almost gets like too + + align:start position:0% +dare I say it almost gets like too + + + align:start position:0% +dare I say it almost gets like too +abstract for me at certain points um + + align:start position:0% +abstract for me at certain points um + + + align:start position:0% +abstract for me at certain points um +where I'm I'm it's clear that he's + + align:start position:0% +where I'm I'm it's clear that he's + + + align:start position:0% +where I'm I'm it's clear that he's +trying to say something but there's + + align:start position:0% +trying to say something but there's + + + align:start position:0% +trying to say something but there's +nothing I can latch on to to understand + + align:start position:0% +nothing I can latch on to to understand + + + align:start position:0% +nothing I can latch on to to understand +what it is and it's entirely his + + align:start position:0% +what it is and it's entirely his + + + align:start position:0% +what it is and it's entirely his +prerogative but for me that's I'm just + + align:start position:0% +prerogative but for me that's I'm just + + + align:start position:0% +prerogative but for me that's I'm just +like what like I have no clue what what + + align:start position:0% +like what like I have no clue what what + + + align:start position:0% +like what like I have no clue what what +this is about at all. Um so so that's a + + align:start position:0% +this is about at all. Um so so that's a + + + align:start position:0% +this is about at all. Um so so that's a +little tricky. + + align:start position:0% +little tricky. + + + align:start position:0% +little tricky. +>> He's not you are not fully grasping. + + align:start position:0% +>> He's not you are not fully grasping. + + + align:start position:0% +>> He's not you are not fully grasping. +>> I'm not apparently I'm not. Yeah. I'm + + align:start position:0% +>> I'm not apparently I'm not. Yeah. I'm + + + align:start position:0% +>> I'm not apparently I'm not. Yeah. I'm +partially. So yeah, it's like the + + align:start position:0% +partially. So yeah, it's like the + + + align:start position:0% +partially. So yeah, it's like the +perfect Fluxus piece of art. So um okay, + + align:start position:0% +perfect Fluxus piece of art. So um okay, + + + align:start position:0% +perfect Fluxus piece of art. So um okay, +so I've only got a couple more to talk + + align:start position:0% +so I've only got a couple more to talk + + + align:start position:0% +so I've only got a couple more to talk +about and I got about 15 minutes. This I + + align:start position:0% +about and I got about 15 minutes. This I + + + align:start position:0% +about and I got about 15 minutes. This I +think is actually one of the most + + align:start position:0% +think is actually one of the most + + + align:start position:0% +think is actually one of the most +important games that we can talk about + + align:start position:0% +important games that we can talk about + + + align:start position:0% +important games that we can talk about +today, which is Cow Clicker, who's + + align:start position:0% +today, which is Cow Clicker, who's + + + align:start position:0% +today, which is Cow Clicker, who's +played Cow Clicker. Yay. Um so this is + + align:start position:0% +played Cow Clicker. Yay. Um so this is + + + align:start position:0% +played Cow Clicker. Yay. Um so this is +um by Ian Bogos, the guy we saw earlier. + + align:start position:0% +um by Ian Bogos, the guy we saw earlier. + + + align:start position:0% +um by Ian Bogos, the guy we saw earlier. +Um and he said, "Cow Clicker is a + + align:start position:0% +Um and he said, "Cow Clicker is a + + + align:start position:0% +Um and he said, "Cow Clicker is a +Facebook game about Facebook games. It's + + align:start position:0% +Facebook game about Facebook games. It's + + + align:start position:0% +Facebook game about Facebook games. It's +partly a satire and partly a playable + + align:start position:0% +partly a satire and partly a playable + + + align:start position:0% +partly a satire and partly a playable +theory of today's social games and + + align:start position:0% +theory of today's social games and + + + align:start position:0% +theory of today's social games and +partly an earnest example of that + + align:start position:0% +partly an earnest example of that + + + align:start position:0% +partly an earnest example of that +genre." Um, so this is kind of like a + + align:start position:0% +genre." Um, so this is kind of like a + + + align:start position:0% +genre." Um, so this is kind of like a +classic sort of art thing to do, right? + + align:start position:0% +classic sort of art thing to do, right? + + + align:start position:0% +classic sort of art thing to do, right? +You take something that you're going to + + align:start position:0% +You take something that you're going to + + + align:start position:0% +You take something that you're going to +satire and you make a version of that + + align:start position:0% +satire and you make a version of that + + + align:start position:0% +satire and you make a version of that +that that maybe does some things + + align:start position:0% +that that maybe does some things + + + align:start position:0% +that that maybe does some things +differently, but is fundamentally what + + align:start position:0% +differently, but is fundamentally what + + + align:start position:0% +differently, but is fundamentally what +you are satiring. It's like the Andy + + align:start position:0% +you are satiring. It's like the Andy + + + align:start position:0% +you are satiring. It's like the Andy +Kaufman comedic kind of style, right? + + align:start position:0% +Kaufman comedic kind of style, right? + + + align:start position:0% +Kaufman comedic kind of style, right? +Where you like you just assume that that + + align:start position:0% +Where you like you just assume that that + + + align:start position:0% +Where you like you just assume that that +kind of character or role. And it's it's + + align:start position:0% +kind of character or role. And it's it's + + + align:start position:0% +kind of character or role. And it's it's +it's something that I think is like kind + + align:start position:0% +it's something that I think is like kind + + + align:start position:0% +it's something that I think is like kind +of like joyfully subversive um in in in + + align:start position:0% +of like joyfully subversive um in in in + + + align:start position:0% +of like joyfully subversive um in in in +doing satire. So hopefully I'm logged + + align:start position:0% +doing satire. So hopefully I'm logged + + + align:start position:0% +doing satire. So hopefully I'm logged +into Facebook so you can see and I + + align:start position:0% +into Facebook so you can see and I + + + align:start position:0% +into Facebook so you can see and I +haven't clicked recently so you guys can + + align:start position:0% +haven't clicked recently so you guys can + + + align:start position:0% +haven't clicked recently so you guys can +witness um one of my clicks. Am I + + align:start position:0% + + + + align:start position:0% + +>> Facebook is down? Facebook is canled + + align:start position:0% +>> Facebook is down? Facebook is canled + + + align:start position:0% +>> Facebook is down? Facebook is canled +forever. + + align:start position:0% +forever. + + + align:start position:0% +forever. +>> Yes. + + align:start position:0% + + + + align:start position:0% + +>> Has no friends. + + align:start position:0% +>> Has no friends. + + + align:start position:0% +>> Has no friends. +>> It's also possible that the wireless + + align:start position:0% +>> It's also possible that the wireless + + + align:start position:0% +>> It's also possible that the wireless +Yeah, the wireless in this in that + + align:start position:0% +Yeah, the wireless in this in that + + + align:start position:0% +Yeah, the wireless in this in that +corner is kind of bad. + + align:start position:0% +corner is kind of bad. + + + align:start position:0% +corner is kind of bad. +>> Oh, should I switch to Google? + + align:start position:0% +>> Oh, should I switch to Google? + + + align:start position:0% +>> Oh, should I switch to Google? +Oh. + + align:start position:0% +Oh. + + + align:start position:0% +Oh. +Um, + + align:start position:0% +Um, + + + align:start position:0% +Um, +so I can actually kind of before we even + + align:start position:0% +so I can actually kind of before we even + + + align:start position:0% +so I can actually kind of before we even +see it, I can talk a little bit about + + align:start position:0% +see it, I can talk a little bit about + + + align:start position:0% +see it, I can talk a little bit about +the sort of interesting controversy that + + align:start position:0% +the sort of interesting controversy that + + + align:start position:0% +the sort of interesting controversy that +Cal Clicker is is creating. Um, it's + + align:start position:0% +Cal Clicker is is creating. Um, it's + + + align:start position:0% +Cal Clicker is is creating. Um, it's +it's making money. + + align:start position:0% +it's making money. + + + align:start position:0% +it's making money. +>> MacBook Airs don't have Let me try + + align:start position:0% +>> MacBook Airs don't have Let me try + + + align:start position:0% +>> MacBook Airs don't have Let me try +Google. + + align:start position:0% +Google. + + + align:start position:0% +Google. +>> Yeah. + + align:start position:0% +>> Yeah. + + + align:start position:0% +>> Yeah. +>> Um, + + align:start position:0% +>> Um, + + + align:start position:0% +>> Um, +I'm not connected. How about now? + + align:start position:0% +I'm not connected. How about now? + + + align:start position:0% +I'm not connected. How about now? +It seems to be working better. + + align:start position:0% + + + + align:start position:0% + +>> Um, so the last part of his statement is + + align:start position:0% +>> Um, so the last part of his statement is + + + align:start position:0% +>> Um, so the last part of his statement is +about an earnest effort in a game. It it + + align:start position:0% +about an earnest effort in a game. It it + + + align:start position:0% +about an earnest effort in a game. It it +it is fundamentally a Facebook game. So + + align:start position:0% +it is fundamentally a Facebook game. So + + + align:start position:0% +it is fundamentally a Facebook game. So +you can see I've got um I've got five + + align:start position:0% +you can see I've got um I've got five + + + align:start position:0% +you can see I've got um I've got five +Mooney. Um my next click is in a minute + + align:start position:0% +Mooney. Um my next click is in a minute + + + align:start position:0% +Mooney. Um my next click is in a minute +and 40. Oh man, I missed one of my + + align:start position:0% +and 40. Oh man, I missed one of my + + + align:start position:0% +and 40. Oh man, I missed one of my +clicks. But maybe if I if we wait while + + align:start position:0% +clicks. But maybe if I if we wait while + + + align:start position:0% +clicks. But maybe if I if we wait while +I talk about it, you can witness one of + + align:start position:0% +I talk about it, you can witness one of + + + align:start position:0% +I talk about it, you can witness one of +my clicks. Um oh wait, I actually have + + align:start position:0% +my clicks. Um oh wait, I actually have + + + align:start position:0% +my clicks. Um oh wait, I actually have +some clicks left. I've got uh I've got, + + align:start position:0% +some clicks left. I've got uh I've got, + + + align:start position:0% +some clicks left. I've got uh I've got, +you know, one this week. But that's in + + align:start position:0% +you know, one this week. But that's in + + + align:start position:0% +you know, one this week. But that's in +two hours. + + align:start position:0% +two hours. + + + align:start position:0% +two hours. +>> Uh, + + align:start position:0% +>> Uh, + + + align:start position:0% +>> Uh, +>> yeah, it looks like that's when I get my + + align:start position:0% +>> yeah, it looks like that's when I get my + + + align:start position:0% +>> yeah, it looks like that's when I get my +next one. So, um, so basically you can + + align:start position:0% +next one. So, um, so basically you can + + + align:start position:0% +next one. So, um, so basically you can +click your cow, + + align:start position:0% +click your cow, + + + align:start position:0% +click your cow, +which + + align:start position:0% +which + + + align:start position:0% +which +why can I not click my cow? + + align:start position:0% +why can I not click my cow? + + + align:start position:0% +why can I not click my cow? +Um, well, you can click your cow and + + align:start position:0% +Um, well, you can click your cow and + + + align:start position:0% +Um, well, you can click your cow and +then you can Oh, it's because I'm on + + align:start position:0% +then you can Oh, it's because I'm on + + + align:start position:0% +then you can Oh, it's because I'm on +scrolling. + + align:start position:0% +scrolling. + + + align:start position:0% +scrolling. +I don't know. Um anyway, you can click + + align:start position:0% +I don't know. Um anyway, you can click + + + align:start position:0% +I don't know. Um anyway, you can click +your cow and then you can use your + + align:start position:0% +your cow and then you can use your + + + align:start position:0% +your cow and then you can use your +mooney uh to buy new cows um that are + + align:start position:0% +mooney uh to buy new cows um that are + + + align:start position:0% +mooney uh to buy new cows um that are +fundamentally the same thing as other + + align:start position:0% +fundamentally the same thing as other + + + align:start position:0% +fundamentally the same thing as other +cows just with aesthetic differences. Um + + align:start position:0% +cows just with aesthetic differences. Um + + + align:start position:0% +cows just with aesthetic differences. Um +so plain cow. Um oh these are the cows I + + align:start position:0% +so plain cow. Um oh these are the cows I + + + align:start position:0% +so plain cow. Um oh these are the cows I +have. I have a plain cow and a steel + + align:start position:0% +have. I have a plain cow and a steel + + + align:start position:0% +have. I have a plain cow and a steel +cow. I haven't been playing a lot of cow + + align:start position:0% +cow. I haven't been playing a lot of cow + + + align:start position:0% +cow. I haven't been playing a lot of cow +clicker. Um if I go to buy a cow, I + + align:start position:0% +clicker. Um if I go to buy a cow, I + + + align:start position:0% +clicker. Um if I go to buy a cow, I +could buy a new cow. Um + + align:start position:0% +could buy a new cow. Um + + + align:start position:0% +could buy a new cow. Um +uh so you can see lots of different cows + + align:start position:0% +uh so you can see lots of different cows + + + align:start position:0% +uh so you can see lots of different cows +um that cost you in-game currency. Um, + + align:start position:0% +um that cost you in-game currency. Um, + + + align:start position:0% +um that cost you in-game currency. Um, +>> paisley cow. + + align:start position:0% +>> paisley cow. + + + align:start position:0% +>> paisley cow. +>> Yeah. Holy cow. + + align:start position:0% +>> Yeah. Holy cow. + + + align:start position:0% +>> Yeah. Holy cow. +Um, oil cow cow retire. Sad. It's got a + + align:start position:0% +Um, oil cow cow retire. Sad. It's got a + + + align:start position:0% +Um, oil cow cow retire. Sad. It's got a +BP logo. It's cute. Um, + + align:start position:0% +BP logo. It's cute. Um, + + + align:start position:0% +BP logo. It's cute. Um, +>> I like BSD cow. Yeah, that's pretty + + align:start position:0% +>> I like BSD cow. Yeah, that's pretty + + + align:start position:0% +>> I like BSD cow. Yeah, that's pretty +good. Um, so there's lots of different + + align:start position:0% +good. Um, so there's lots of different + + + align:start position:0% +good. Um, so there's lots of different +cows and you can buy cows. You can give + + align:start position:0% +cows and you can buy cows. You can give + + + align:start position:0% +cows and you can buy cows. You can give +cows. You can invite a cow. Um, there's + + align:start position:0% +cows. You can invite a cow. Um, there's + + + align:start position:0% +cows. You can invite a cow. Um, there's +cow rankings. Um, + + align:start position:0% +cow rankings. Um, + + + align:start position:0% +cow rankings. Um, +>> invite a cow. + + align:start position:0% +>> invite a cow. + + + align:start position:0% +>> invite a cow. +>> Uh, you can So you can see, you know, + + align:start position:0% +>> Uh, you can So you can see, you know, + + + align:start position:0% +>> Uh, you can So you can see, you know, +Mooney is actually pretty inflated at + + align:start position:0% +Mooney is actually pretty inflated at + + + align:start position:0% +Mooney is actually pretty inflated at +this point. You can get 10 Mooney for 50 + + align:start position:0% +this point. You can get 10 Mooney for 50 + + + align:start position:0% +this point. You can get 10 Mooney for 50 +cents, which is pretty great. Thousand + + align:start position:0% +cents, which is pretty great. Thousand + + + align:start position:0% +cents, which is pretty great. Thousand +for $10, which is kind of awesome. um + + align:start position:0% +for $10, which is kind of awesome. um + + + align:start position:0% +for $10, which is kind of awesome. um +and you know collect a lot of cows and + + align:start position:0% +and you know collect a lot of cows and + + + align:start position:0% +and you know collect a lot of cows and +you can trade cows and you know you can + + align:start position:0% +you can trade cows and you know you can + + + align:start position:0% +you can trade cows and you know you can +go to your friends barns and see how + + align:start position:0% +go to your friends barns and see how + + + align:start position:0% +go to your friends barns and see how +many cows they have and um and you can + + align:start position:0% +many cows they have and um and you can + + + align:start position:0% +many cows they have and um and you can +click on your cows when you make make + + align:start position:0% +click on your cows when you make make + + + align:start position:0% +click on your cows when you make make +your appointment to actually cow. Um so + + align:start position:0% +your appointment to actually cow. Um so + + + align:start position:0% +your appointment to actually cow. Um so +I mean I think you can see how he's + + align:start position:0% +I mean I think you can see how he's + + + align:start position:0% +I mean I think you can see how he's +poking fun at um things like Farmville + + align:start position:0% +poking fun at um things like Farmville + + + align:start position:0% +poking fun at um things like Farmville +uh things like Ravenwood Fair which I'm + + align:start position:0% +uh things like Ravenwood Fair which I'm + + + align:start position:0% +uh things like Ravenwood Fair which I'm +obsessed with now actually. um these + + align:start position:0% +obsessed with now actually. um these + + + align:start position:0% +obsessed with now actually. um these +kind of games where all you're + + align:start position:0% +kind of games where all you're + + + align:start position:0% +kind of games where all you're +fundamentally doing is clicking uh and + + align:start position:0% +fundamentally doing is clicking uh and + + + align:start position:0% +fundamentally doing is clicking uh and +acquiring an in-game currency that you + + align:start position:0% +acquiring an in-game currency that you + + + align:start position:0% +acquiring an in-game currency that you +can then use for in-game goods. Um but + + align:start position:0% +can then use for in-game goods. Um but + + + align:start position:0% +can then use for in-game goods. Um but +then of course you reach this barrier + + align:start position:0% +then of course you reach this barrier + + + align:start position:0% +then of course you reach this barrier +where you don't have enough in-game + + align:start position:0% +where you don't have enough in-game + + + align:start position:0% +where you don't have enough in-game +currency and you need to use real + + align:start position:0% +currency and you need to use real + + + align:start position:0% +currency and you need to use real +currency. Of course, the interesting + + align:start position:0% +currency. Of course, the interesting + + + align:start position:0% +currency. Of course, the interesting +thing is like there are like I don't + + align:start position:0% +thing is like there are like I don't + + + align:start position:0% +thing is like there are like I don't +know 500,000 people playing this or I + + align:start position:0% +know 500,000 people playing this or I + + + align:start position:0% +know 500,000 people playing this or I +don't know if it's that many. It's a + + align:start position:0% +don't know if it's that many. It's a + + + align:start position:0% +don't know if it's that many. It's a +lot. Um here if we go to the cow clicker + + align:start position:0% +lot. Um here if we go to the cow clicker + + + align:start position:0% +lot. Um here if we go to the cow clicker +front page, right, it'll tell us oh Jera + + align:start position:0% +front page, right, it'll tell us oh Jera + + + align:start position:0% +front page, right, it'll tell us oh Jera +was at St. Barthol. + + align:start position:0% +was at St. Barthol. + + + align:start position:0% +was at St. Barthol. +>> Um where does it say how many players + + align:start position:0% +>> Um where does it say how many players + + + align:start position:0% +>> Um where does it say how many players +there are? ranking. + + align:start position:0% +there are? ranking. + + + align:start position:0% +there are? ranking. +>> Ranking. Yeah, + + align:start position:0% +>> Ranking. Yeah, + + + align:start position:0% +>> Ranking. Yeah, +>> I did that on board news. + + align:start position:0% +>> I did that on board news. + + + align:start position:0% +>> I did that on board news. +>> Who's milking the cow clicker? + + align:start position:0% +>> Who's milking the cow clicker? + + + align:start position:0% +>> Who's milking the cow clicker? +>> You can see this person's Monica's + + align:start position:0% +>> You can see this person's Monica's + + + align:start position:0% +>> You can see this person's Monica's +>> no count. + + align:start position:0% +>> no count. + + + align:start position:0% +>> no count. +>> Oh, + + align:start position:0% +>> Oh, + + + align:start position:0% +>> Oh, +>> um + + align:start position:0% +>> um + + + align:start position:0% +>> um +>> yeah, maybe all clicks or this week. + + align:start position:0% +>> yeah, maybe all clicks or this week. + + + align:start position:0% +>> yeah, maybe all clicks or this week. +>> Is there like a Oh, + + align:start position:0% +>> Is there like a Oh, + + + align:start position:0% +>> Is there like a Oh, +>> here we go. Yeah. Yeah. + + align:start position:0% +>> here we go. Yeah. Yeah. + + + align:start position:0% +>> here we go. Yeah. Yeah. +>> Um + + align:start position:0% +>> Um + + + align:start position:0% +>> Um +>> 12,000 + + align:start position:0% +>> 12,000 + + + align:start position:0% +>> 12,000 +>> 12,000 monthly active users. Yes. + + align:start position:0% +>> 12,000 monthly active users. Yes. + + + align:start position:0% +>> 12,000 monthly active users. Yes. +500,000 a bit of a stretch, but um but + + align:start position:0% +500,000 a bit of a stretch, but um but + + + align:start position:0% +500,000 a bit of a stretch, but um but +that's a lot of people and he's making + + align:start position:0% +that's a lot of people and he's making + + + align:start position:0% +that's a lot of people and he's making +some interesting money on it. And I + + align:start position:0% +some interesting money on it. And I + + + align:start position:0% +some interesting money on it. And I +think one of the things that was + + align:start position:0% +think one of the things that was + + + align:start position:0% +think one of the things that was +important that he did is there's kind of + + align:start position:0% +important that he did is there's kind of + + + align:start position:0% +important that he did is there's kind of +an active forum where people can kind of + + align:start position:0% +an active forum where people can kind of + + + align:start position:0% +an active forum where people can kind of +talk about it and so it is a little bit + + align:start position:0% +talk about it and so it is a little bit + + + align:start position:0% +talk about it and so it is a little bit +weirdly controversial, right? Because he + + align:start position:0% +weirdly controversial, right? Because he + + + align:start position:0% +weirdly controversial, right? Because he +made this game that is, you know, poking + + align:start position:0% +made this game that is, you know, poking + + + align:start position:0% +made this game that is, you know, poking +fun at Facebook games and yet it is a + + align:start position:0% +fun at Facebook games and yet it is a + + + align:start position:0% +fun at Facebook games and yet it is a +Facebook game and it's, you know, + + align:start position:0% +Facebook game and it's, you know, + + + align:start position:0% +Facebook game and it's, you know, +presumably making some money, too. So, + + align:start position:0% +presumably making some money, too. So, + + + align:start position:0% +presumably making some money, too. So, +um but I think it's really good. I think + + align:start position:0% +um but I think it's really good. I think + + + align:start position:0% +um but I think it's really good. I think +it's, you know, this is the kind of art + + align:start position:0% +it's, you know, this is the kind of art + + + align:start position:0% +it's, you know, this is the kind of art +that's also important where it's like + + align:start position:0% +that's also important where it's like + + + align:start position:0% +that's also important where it's like +taking what we do and purposely looking + + align:start position:0% +taking what we do and purposely looking + + + align:start position:0% +taking what we do and purposely looking +at at at how is it constructed and how + + align:start position:0% +at at at how is it constructed and how + + + align:start position:0% +at at at how is it constructed and how +is it set up and and satiring it and + + align:start position:0% +is it set up and and satiring it and + + + align:start position:0% +is it set up and and satiring it and +forcing us to kind of be introspective + + align:start position:0% +forcing us to kind of be introspective + + + align:start position:0% +forcing us to kind of be introspective +about the things that we do in the way + + align:start position:0% +about the things that we do in the way + + + align:start position:0% +about the things that we do in the way +that we engage. Um, and so this is a + + align:start position:0% +that we engage. Um, and so this is a + + + align:start position:0% +that we engage. Um, and so this is a +kind of subversive game design that I + + align:start position:0% +kind of subversive game design that I + + + align:start position:0% +kind of subversive game design that I +think you know along the lines of Paulo + + align:start position:0% +think you know along the lines of Paulo + + + align:start position:0% +think you know along the lines of Paulo +Pedroini's work and um and even Galafa + + align:start position:0% +Pedroini's work and um and even Galafa + + + align:start position:0% +Pedroini's work and um and even Galafa +is kind of forcing us to look at how we + + align:start position:0% +is kind of forcing us to look at how we + + + align:start position:0% +is kind of forcing us to look at how we +interact. Um, and cow clicker cow + + align:start position:0% +interact. Um, and cow clicker cow + + + align:start position:0% +interact. Um, and cow clicker cow +clicker is really fun. Um uh so that's + + align:start position:0% +clicker is really fun. Um uh so that's + + + align:start position:0% +clicker is really fun. Um uh so that's +that one and I've got like 15 minutes. + + align:start position:0% +that one and I've got like 15 minutes. + + + align:start position:0% +that one and I've got like 15 minutes. +Philip asked me to talk a little bit + + align:start position:0% +Philip asked me to talk a little bit + + + align:start position:0% +Philip asked me to talk a little bit +about um some work that I'm doing in + + align:start position:0% +about um some work that I'm doing in + + + align:start position:0% +about um some work that I'm doing in +this space. Um so I'm going to talk to + + align:start position:0% +this space. Um so I'm going to talk to + + + align:start position:0% +this space. Um so I'm going to talk to +you about a game uh that I'm it's a work + + align:start position:0% +you about a game uh that I'm it's a work + + + align:start position:0% +you about a game uh that I'm it's a work +in progress. It's tenatively titled + + align:start position:0% +in progress. It's tenatively titled + + + align:start position:0% +in progress. It's tenatively titled +before and ends now. Um and it's by me. + + align:start position:0% +before and ends now. Um and it's by me. + + + align:start position:0% +before and ends now. Um and it's by me. +Um and the idea from it is it's inspired + + align:start position:0% +Um and the idea from it is it's inspired + + + align:start position:0% +Um and the idea from it is it's inspired +a bit by Flexus boxes. Um and those kind + + align:start position:0% +a bit by Flexus boxes. Um and those kind + + + align:start position:0% +a bit by Flexus boxes. Um and those kind +of flux kits. Um, I wanted to I'm really + + align:start position:0% +of flux kits. Um, I wanted to I'm really + + + align:start position:0% +of flux kits. Um, I wanted to I'm really +interested in in like physically + + align:start position:0% +interested in in like physically + + + align:start position:0% +interested in in like physically +tangible games. I don't know why I'm uh + + align:start position:0% +tangible games. I don't know why I'm uh + + + align:start position:0% +tangible games. I don't know why I'm uh +all of a sudden kind of obsessed with + + align:start position:0% +all of a sudden kind of obsessed with + + + align:start position:0% +all of a sudden kind of obsessed with +with holding something, but I was at + + align:start position:0% +with holding something, but I was at + + + align:start position:0% +with holding something, but I was at +indicate and I heard again and it this + + align:start position:0% +indicate and I heard again and it this + + + align:start position:0% +indicate and I heard again and it this +is like the question that drives me more + + align:start position:0% +is like the question that drives me more + + + align:start position:0% +is like the question that drives me more +nuts than than the um than the are video + + align:start position:0% +nuts than than the um than the are video + + + align:start position:0% +nuts than than the um than the are video +games art question, although they're + + align:start position:0% +games art question, although they're + + + align:start position:0% +games art question, although they're +interestingly related, but it's, you + + align:start position:0% +interestingly related, but it's, you + + + align:start position:0% +interestingly related, but it's, you +know, when will we have the citizen cane + + align:start position:0% +know, when will we have the citizen cane + + + align:start position:0% +know, when will we have the citizen cane +in video games? It drives me absolutely + + align:start position:0% +in video games? It drives me absolutely + + + align:start position:0% +in video games? It drives me absolutely +nuts. I think uh 80% of the time the + + align:start position:0% +nuts. I think uh 80% of the time the + + + align:start position:0% +nuts. I think uh 80% of the time the +people who say that have never seen + + align:start position:0% +people who say that have never seen + + + align:start position:0% +people who say that have never seen +citizen cane. Um so I don't really know + + align:start position:0% +citizen cane. Um so I don't really know + + + align:start position:0% +citizen cane. Um so I don't really know +what that means. Um, but I had heard it + + align:start position:0% +what that means. Um, but I had heard it + + + align:start position:0% +what that means. Um, but I had heard it +like for the eenth time in Indie Kane + + align:start position:0% +like for the eenth time in Indie Kane + + + align:start position:0% +like for the eenth time in Indie Kane +and I wanted to throw the television in + + align:start position:0% +and I wanted to throw the television in + + + align:start position:0% +and I wanted to throw the television in +my out of my hotel room window and I was + + align:start position:0% +my out of my hotel room window and I was + + + align:start position:0% +my out of my hotel room window and I was +like I was going nuts and I was like, + + align:start position:0% +like I was going nuts and I was like, + + + align:start position:0% +like I was going nuts and I was like, +"All right, well well what is Citizen + + align:start position:0% +"All right, well well what is Citizen + + + align:start position:0% +"All right, well well what is Citizen +Kane about?" And I don't want to spoil + + align:start position:0% +Kane about?" And I don't want to spoil + + + align:start position:0% +Kane about?" And I don't want to spoil +it. Who's seen Citizen Kane in this + + align:start position:0% +it. Who's seen Citizen Kane in this + + + align:start position:0% +it. Who's seen Citizen Kane in this +room? Actually, a handful of people. All + + align:start position:0% +room? Actually, a handful of people. All + + + align:start position:0% +room? Actually, a handful of people. All +right, good. Um, + + align:start position:0% +right, good. Um, + + + align:start position:0% +right, good. Um, +>> so so I, you know, I see Citizen Kane + + align:start position:0% +>> so so I, you know, I see Citizen Kane + + + align:start position:0% +>> so so I, you know, I see Citizen Kane +and it's about this very kind of, you + + align:start position:0% +and it's about this very kind of, you + + + align:start position:0% +and it's about this very kind of, you +know, interesting + + align:start position:0% +know, interesting + + + align:start position:0% +know, interesting +um idea about, you know, presence and + + align:start position:0% +um idea about, you know, presence and + + + align:start position:0% +um idea about, you know, presence and +and momentos and and happiness uh in a + + align:start position:0% +and momentos and and happiness uh in a + + + align:start position:0% +and momentos and and happiness uh in a +very kind of real way and like the + + align:start position:0% +very kind of real way and like the + + + align:start position:0% +very kind of real way and like the +temporality of happiness, right? Like + + align:start position:0% +temporality of happiness, right? Like + + + align:start position:0% +temporality of happiness, right? Like +are you happy now? Were you happy then? + + align:start position:0% +are you happy now? Were you happy then? + + + align:start position:0% +are you happy now? Were you happy then? +Do you remember being happy? When when + + align:start position:0% +Do you remember being happy? When when + + + align:start position:0% +Do you remember being happy? When when +is happiness? Um, and so I was like, + + align:start position:0% +is happiness? Um, and so I was like, + + + align:start position:0% +is happiness? Um, and so I was like, +well, I'm going to make a Citizen Cane + + align:start position:0% +well, I'm going to make a Citizen Cane + + + align:start position:0% +well, I'm going to make a Citizen Cane +of video games, but it's not going to be + + align:start position:0% +of video games, but it's not going to be + + + align:start position:0% +of video games, but it's not going to be +it's not going to be known for being uh + + align:start position:0% +it's not going to be known for being uh + + + align:start position:0% +it's not going to be known for being uh +uh epically innovative, you know, with + + align:start position:0% +uh epically innovative, you know, with + + + align:start position:0% +uh epically innovative, you know, with +camera movement. Um, it's it's going to + + align:start position:0% +camera movement. Um, it's it's going to + + + align:start position:0% +camera movement. Um, it's it's going to +be about the things I think Citizen Cane + + align:start position:0% +be about the things I think Citizen Cane + + + align:start position:0% +be about the things I think Citizen Cane +are about. Um, so it's it's basically um + + align:start position:0% +are about. Um, so it's it's basically um + + + align:start position:0% +are about. Um, so it's it's basically um +you know in this form uh although I'm + + align:start position:0% +you know in this form uh although I'm + + + align:start position:0% +you know in this form uh although I'm +I'm rethinking what kind of box it's + + align:start position:0% +I'm rethinking what kind of box it's + + + align:start position:0% +I'm rethinking what kind of box it's +going to be in but in this form it's a + + align:start position:0% +going to be in but in this form it's a + + + align:start position:0% +going to be in but in this form it's a +box and inside of it are various objects + + align:start position:0% +box and inside of it are various objects + + + align:start position:0% +box and inside of it are various objects +that start out as uh the starting + + align:start position:0% +that start out as uh the starting + + + align:start position:0% +that start out as uh the starting +objects for the box are things that have + + align:start position:0% +objects for the box are things that have + + + align:start position:0% +objects for the box are things that have +personal significance to me. Um and one + + align:start position:0% +personal significance to me. Um and one + + + align:start position:0% +personal significance to me. Um and one +of the rules of the game in fact I think + + align:start position:0% +of the rules of the game in fact I think + + + align:start position:0% +of the rules of the game in fact I think +the most important rule of the game uh + + align:start position:0% +the most important rule of the game uh + + + align:start position:0% +the most important rule of the game uh +is this one. Rule number one you may + + align:start position:0% +is this one. Rule number one you may + + + align:start position:0% +is this one. Rule number one you may +permanently exchange an object of + + align:start position:0% +permanently exchange an object of + + + align:start position:0% +permanently exchange an object of +personal significance for any object of + + align:start position:0% +personal significance for any object of + + + align:start position:0% +personal significance for any object of +equal value. So when you're playing this + + align:start position:0% +equal value. So when you're playing this + + + align:start position:0% +equal value. So when you're playing this +game, you can take something that + + align:start position:0% +game, you can take something that + + + align:start position:0% +game, you can take something that +belongs to you and you can exchange it + + align:start position:0% +belongs to you and you can exchange it + + + align:start position:0% +belongs to you and you can exchange it +for anything in the box. Um and then of + + align:start position:0% +for anything in the box. Um and then of + + + align:start position:0% +for anything in the box. Um and then of +course the interesting thing is these + + align:start position:0% +course the interesting thing is these + + + align:start position:0% +course the interesting thing is these +these um these objects in the box are of + + align:start position:0% +these um these objects in the box are of + + + align:start position:0% +these um these objects in the box are of +varying uh degrees of interactivity, + + align:start position:0% +varying uh degrees of interactivity, + + + align:start position:0% +varying uh degrees of interactivity, +right? Like you can do them in Etcha + + align:start position:0% +right? Like you can do them in Etcha + + + align:start position:0% +right? Like you can do them in Etcha +Sketch. So you can draw something on the + + align:start position:0% +Sketch. So you can draw something on the + + + align:start position:0% +Sketch. So you can draw something on the +Etcha sketch. Um and um you know the + + align:start position:0% +Etcha sketch. Um and um you know the + + + align:start position:0% +Etcha sketch. Um and um you know the +rules are kind of veiled in this moment + + align:start position:0% +rules are kind of veiled in this moment + + + align:start position:0% +rules are kind of veiled in this moment +now where there's like a couple other + + align:start position:0% +now where there's like a couple other + + + align:start position:0% +now where there's like a couple other +rules that you know are causing you to + + align:start position:0% +rules that you know are causing you to + + + align:start position:0% +rules that you know are causing you to +reflect. This is actually an extension + + align:start position:0% +reflect. This is actually an extension + + + align:start position:0% +reflect. This is actually an extension +of uh Yet One Word, which was a project + + align:start position:0% +of uh Yet One Word, which was a project + + + align:start position:0% +of uh Yet One Word, which was a project +we worked on in the summer, which was a + + align:start position:0% +we worked on in the summer, which was a + + + align:start position:0% +we worked on in the summer, which was a +game that um as you're playing, it's a + + align:start position:0% +game that um as you're playing, it's a + + + align:start position:0% +game that um as you're playing, it's a +platformer, and you're typing, the game + + align:start position:0% +platformer, and you're typing, the game + + + align:start position:0% +platformer, and you're typing, the game +stops and asks you personal questions. + + align:start position:0% +stops and asks you personal questions. + + + align:start position:0% +stops and asks you personal questions. +And what I really liked about that is it + + align:start position:0% +And what I really liked about that is it + + + align:start position:0% +And what I really liked about that is it +was doing something that I was kind of + + align:start position:0% +was doing something that I was kind of + + + align:start position:0% +was doing something that I was kind of +referring to as a um as a mechanic of + + align:start position:0% +referring to as a um as a mechanic of + + + align:start position:0% +referring to as a um as a mechanic of +reflection where where the the the + + align:start position:0% +reflection where where the the the + + + align:start position:0% +reflection where where the the the +activity of play is is reflecting, is + + align:start position:0% +activity of play is is reflecting, is + + + align:start position:0% +activity of play is is reflecting, is +thinking, is you know, just + + align:start position:0% +thinking, is you know, just + + + align:start position:0% +thinking, is you know, just +contemplating. Um it's not interactive + + align:start position:0% +contemplating. Um it's not interactive + + + align:start position:0% +contemplating. Um it's not interactive +in a very kind of, you know, active way + + align:start position:0% +in a very kind of, you know, active way + + + align:start position:0% +in a very kind of, you know, active way +as we think of it. It's more reflective. + + align:start position:0% +as we think of it. It's more reflective. + + + align:start position:0% +as we think of it. It's more reflective. +I I liken it to the moments in chess + + align:start position:0% +I I liken it to the moments in chess + + + align:start position:0% +I I liken it to the moments in chess +where you're planning your move. There's + + align:start position:0% +where you're planning your move. There's + + + align:start position:0% +where you're planning your move. There's +not a lot of action in chess. There's a + + align:start position:0% +not a lot of action in chess. There's a + + + align:start position:0% +not a lot of action in chess. There's a +lot of contemplation in chess. Um so if + + align:start position:0% +lot of contemplation in chess. Um so if + + + align:start position:0% +lot of contemplation in chess. Um so if +it's personal, you know what if that + + align:start position:0% +it's personal, you know what if that + + + align:start position:0% +it's personal, you know what if that +were what if that were personal? And so + + align:start position:0% +were what if that were personal? And so + + + align:start position:0% +were what if that were personal? And so +what I what I don't particularly care + + align:start position:0% +what I what I don't particularly care + + + align:start position:0% +what I what I don't particularly care +about with yet one word is that it + + align:start position:0% +about with yet one word is that it + + + align:start position:0% +about with yet one word is that it +doesn't it it it inspires you to + + align:start position:0% +doesn't it it it inspires you to + + + align:start position:0% +doesn't it it it inspires you to +reflect, but it doesn't do it with with + + align:start position:0% +reflect, but it doesn't do it with with + + + align:start position:0% +reflect, but it doesn't do it with with +tremendous grace. It just asks you a + + align:start position:0% +tremendous grace. It just asks you a + + + align:start position:0% +tremendous grace. It just asks you a +question. It just comes out, you know, + + align:start position:0% +question. It just comes out, you know, + + + align:start position:0% +question. It just comes out, you know, +kind of out of the blue and says, "Hey, + + align:start position:0% +kind of out of the blue and says, "Hey, + + + align:start position:0% +kind of out of the blue and says, "Hey, +you know, when was the last time you + + align:start position:0% +you know, when was the last time you + + + align:start position:0% +you know, when was the last time you +lied?" Um, and if you, you know, + + align:start position:0% +lied?" Um, and if you, you know, + + + align:start position:0% +lied?" Um, and if you, you know, +sometimes you're surprised by that and + + align:start position:0% +sometimes you're surprised by that and + + + align:start position:0% +sometimes you're surprised by that and +that's a good effect, but it's also not, + + align:start position:0% +that's a good effect, but it's also not, + + + align:start position:0% +that's a good effect, but it's also not, +um, subtle. Um, and so I'm trying to + + align:start position:0% +um, subtle. Um, and so I'm trying to + + + align:start position:0% +um, subtle. Um, and so I'm trying to +explore how can we be subtle in in + + align:start position:0% +explore how can we be subtle in in + + + align:start position:0% +explore how can we be subtle in in +causing reflection. And so there are a + + align:start position:0% +causing reflection. And so there are a + + + align:start position:0% +causing reflection. And so there are a +few things here. I mean, the value + + align:start position:0% +few things here. I mean, the value + + + align:start position:0% +few things here. I mean, the value +question is interesting. How do you know + + align:start position:0% +question is interesting. How do you know + + + align:start position:0% +question is interesting. How do you know +what the value of the object is in the + + align:start position:0% +what the value of the object is in the + + + align:start position:0% +what the value of the object is in the +box? Um, do you think of it as a + + align:start position:0% +box? Um, do you think of it as a + + + align:start position:0% +box? Um, do you think of it as a +monetary value? Do you think of it as + + align:start position:0% +monetary value? Do you think of it as + + + align:start position:0% +monetary value? Do you think of it as +value in terms of significance to the + + align:start position:0% +value in terms of significance to the + + + align:start position:0% +value in terms of significance to the +person who put that in there? Um, why is + + align:start position:0% +person who put that in there? Um, why is + + + align:start position:0% +person who put that in there? Um, why is +it significant to the person who put + + align:start position:0% +it significant to the person who put + + + align:start position:0% +it significant to the person who put +that in there? Like what is this thing? + + align:start position:0% +that in there? Like what is this thing? + + + align:start position:0% +that in there? Like what is this thing? +Right? you can look at and reflect and + + align:start position:0% +Right? you can look at and reflect and + + + align:start position:0% +Right? you can look at and reflect and +and then when you leave a trace of + + align:start position:0% +and then when you leave a trace of + + + align:start position:0% +and then when you leave a trace of +yourself in this box, the next person + + align:start position:0% +yourself in this box, the next person + + + align:start position:0% +yourself in this box, the next person +who comes and plays is is going to see + + align:start position:0% +who comes and plays is is going to see + + + align:start position:0% +who comes and plays is is going to see +that and they're going to wonder what + + align:start position:0% +that and they're going to wonder what + + + align:start position:0% +that and they're going to wonder what +was what was that? And so I'm also kind + + align:start position:0% +was what was that? And so I'm also kind + + + align:start position:0% +was what was that? And so I'm also kind +of interested in like um the organicness + + align:start position:0% +of interested in like um the organicness + + + align:start position:0% +of interested in like um the organicness +uh the kind of uh uh the in the the + + align:start position:0% +uh the kind of uh uh the in the the + + + align:start position:0% +uh the kind of uh uh the in the the +never- ending interminable nature of a + + align:start position:0% +never- ending interminable nature of a + + + align:start position:0% +never- ending interminable nature of a +game that that carries the effect of a + + align:start position:0% +game that that carries the effect of a + + + align:start position:0% +game that that carries the effect of a +person who's played it kind of on and on + + align:start position:0% +person who's played it kind of on and on + + + align:start position:0% +person who's played it kind of on and on +and on. Um, the next iteration of this + + align:start position:0% +and on. Um, the next iteration of this + + + align:start position:0% +and on. Um, the next iteration of this +that I want to do, actually, this was an + + align:start position:0% +that I want to do, actually, this was an + + + align:start position:0% +that I want to do, actually, this was an +idea that Jason Bean gave me was to use + + align:start position:0% +idea that Jason Bean gave me was to use + + + align:start position:0% +idea that Jason Bean gave me was to use +um an apothecary chest. Um, because one + + align:start position:0% +um an apothecary chest. Um, because one + + + align:start position:0% +um an apothecary chest. Um, because one +of the things that we play tested it + + align:start position:0% +of the things that we play tested it + + + align:start position:0% +of the things that we play tested it +here with, I left it out for like two + + align:start position:0% +here with, I left it out for like two + + + align:start position:0% +here with, I left it out for like two +weeks and and people, you probably saw + + align:start position:0% +weeks and and people, you probably saw + + + align:start position:0% +weeks and and people, you probably saw +it, it was right there. Um, you know, + + align:start position:0% +it, it was right there. Um, you know, + + + align:start position:0% +it, it was right there. Um, you know, +people were engaging. And this is + + align:start position:0% +people were engaging. And this is + + + align:start position:0% +people were engaging. And this is +actually this is like a photo with + + align:start position:0% +actually this is like a photo with + + + align:start position:0% +actually this is like a photo with +objects that people had left in. So, it + + align:start position:0% +objects that people had left in. So, it + + + align:start position:0% +objects that people had left in. So, it +was really fun for me after two weeks to + + align:start position:0% +was really fun for me after two weeks to + + + align:start position:0% +was really fun for me after two weeks to +kind of go into this box and be like, + + align:start position:0% +kind of go into this box and be like, + + + align:start position:0% +kind of go into this box and be like, +what is all this stuff? You know, like + + align:start position:0% +what is all this stuff? You know, like + + + align:start position:0% +what is all this stuff? You know, like +like what got left? I was actually + + align:start position:0% +like what got left? I was actually + + + align:start position:0% +like what got left? I was actually +surprised the sketch, you know, was left + + align:start position:0% +surprised the sketch, you know, was left + + + align:start position:0% +surprised the sketch, you know, was left +and then but I was like, wow, what is + + align:start position:0% +and then but I was like, wow, what is + + + align:start position:0% +and then but I was like, wow, what is +this stuff? Um, and and to give you one + + align:start position:0% +this stuff? Um, and and to give you one + + + align:start position:0% +this stuff? Um, and and to give you one +really good example, um, one person at + + align:start position:0% +really good example, um, one person at + + + align:start position:0% +really good example, um, one person at +the lab put in a Nintendo DS flash card, + + align:start position:0% +the lab put in a Nintendo DS flash card, + + + align:start position:0% +the lab put in a Nintendo DS flash card, +um, which was really like a wrapped DS + + align:start position:0% +um, which was really like a wrapped DS + + + align:start position:0% +um, which was really like a wrapped DS +flash card. And so now there's this kind + + align:start position:0% +flash card. And so now there's this kind + + + align:start position:0% +flash card. And so now there's this kind +of this kind of next level. The game has + + align:start position:0% +of this kind of next level. The game has + + + align:start position:0% +of this kind of next level. The game has +changed with another level of + + align:start position:0% +changed with another level of + + + align:start position:0% +changed with another level of +interactivity where it's like if I want + + align:start position:0% +interactivity where it's like if I want + + + align:start position:0% +interactivity where it's like if I want +to kind of get at what was the uh, what + + align:start position:0% +to kind of get at what was the uh, what + + + align:start position:0% +to kind of get at what was the uh, what +was the significance of this object to + + align:start position:0% +was the significance of this object to + + + align:start position:0% +was the significance of this object to +this person, I need to I need to get a + + align:start position:0% +this person, I need to I need to get a + + + align:start position:0% +this person, I need to I need to get a +DS and play this, right? Right. So then + + align:start position:0% +DS and play this, right? Right. So then + + + align:start position:0% +DS and play this, right? Right. So then +I open up the and it's got it's got + + align:start position:0% +I open up the and it's got it's got + + + align:start position:0% +I open up the and it's got it's got +folders and it's got um you know a copy + + align:start position:0% +folders and it's got um you know a copy + + + align:start position:0% +folders and it's got um you know a copy +of the game Lemmings. It's got some + + align:start position:0% +of the game Lemmings. It's got some + + + align:start position:0% +of the game Lemmings. It's got some +music in it. Right. And so now it's kind + + align:start position:0% +music in it. Right. And so now it's kind + + + align:start position:0% +music in it. Right. And so now it's kind +of like you've you've like uncovered + + align:start position:0% +of like you've you've like uncovered + + + align:start position:0% +of like you've you've like uncovered +this next layer and it's like you know + + align:start position:0% +this next layer and it's like you know + + + align:start position:0% +this next layer and it's like you know +the interesting traces of the people who + + align:start position:0% +the interesting traces of the people who + + + align:start position:0% +the interesting traces of the people who +have played this game are are now you + + align:start position:0% +have played this game are are now you + + + align:start position:0% +have played this game are are now you +know uh you know marked onto this onto + + align:start position:0% +know uh you know marked onto this onto + + + align:start position:0% +know uh you know marked onto this onto +this box forever. Marley even said to me + + align:start position:0% +this box forever. Marley even said to me + + + align:start position:0% +this box forever. Marley even said to me +I was like talking to her about her play + + align:start position:0% +I was like talking to her about her play + + + align:start position:0% +I was like talking to her about her play +after she had done it and I was like um + + align:start position:0% +after she had done it and I was like um + + + align:start position:0% +after she had done it and I was like um +she told me she wanted to take the + + align:start position:0% +she told me she wanted to take the + + + align:start position:0% +she told me she wanted to take the +instructions. um she wanted to take the + + align:start position:0% +instructions. um she wanted to take the + + + align:start position:0% +instructions. um she wanted to take the +rules as one of the objects that she + + align:start position:0% +rules as one of the objects that she + + + align:start position:0% +rules as one of the objects that she +could take out of that. And I told her I + + align:start position:0% +could take out of that. And I told her I + + + align:start position:0% +could take out of that. And I told her I +had thought about that actually when I + + align:start position:0% +had thought about that actually when I + + + align:start position:0% +had thought about that actually when I +was designing it that someone might be + + align:start position:0% +was designing it that someone might be + + + align:start position:0% +was designing it that someone might be +like, "Ha, I'm going to take the rules." + + align:start position:0% +like, "Ha, I'm going to take the rules." + + + align:start position:0% +like, "Ha, I'm going to take the rules." +And and I was going to put in a rule + + align:start position:0% +And and I was going to put in a rule + + + align:start position:0% +And and I was going to put in a rule +that said, you know, you can turn the + + align:start position:0% +that said, you know, you can turn the + + + align:start position:0% +that said, you know, you can turn the +exchange for an object that's not the + + align:start position:0% +exchange for an object that's not the + + + align:start position:0% +exchange for an object that's not the +rule is so that the game could persist. + + align:start position:0% +rule is so that the game could persist. + + + align:start position:0% +rule is so that the game could persist. +But I but I didn't want I didn't want to + + align:start position:0% +But I but I didn't want I didn't want to + + + align:start position:0% +But I but I didn't want I didn't want to +artificially impose that if someone + + align:start position:0% +artificially impose that if someone + + + align:start position:0% +artificially impose that if someone +takes the rules because that's what they + + align:start position:0% +takes the rules because that's what they + + + align:start position:0% +takes the rules because that's what they +want. That's what and now the game is + + align:start position:0% +want. That's what and now the game is + + + align:start position:0% +want. That's what and now the game is +the game has changed. And maybe someone + + align:start position:0% +the game has changed. And maybe someone + + + align:start position:0% +the game has changed. And maybe someone +comes along later and and modifies it. + + align:start position:0% +comes along later and and modifies it. + + + align:start position:0% +comes along later and and modifies it. +Maybe they put something in that makes + + align:start position:0% +Maybe they put something in that makes + + + align:start position:0% +Maybe they put something in that makes +it a whole new different game. And and I + + align:start position:0% +it a whole new different game. And and I + + + align:start position:0% +it a whole new different game. And and I +really like the idea that you can + + align:start position:0% +really like the idea that you can + + + align:start position:0% +really like the idea that you can +encounter this game and that it's going + + align:start position:0% +encounter this game and that it's going + + + align:start position:0% +encounter this game and that it's going +to be kind of in this state of flux, I + + align:start position:0% +to be kind of in this state of flux, I + + + align:start position:0% +to be kind of in this state of flux, I +guess you could say. Um, and so that's + + align:start position:0% +guess you could say. Um, and so that's + + + align:start position:0% +guess you could say. Um, and so that's +what I'm that's what I'm working on now. + + align:start position:0% +what I'm that's what I'm working on now. + + + align:start position:0% +what I'm that's what I'm working on now. +And like I said, it's going to I think + + align:start position:0% +And like I said, it's going to I think + + + align:start position:0% +And like I said, it's going to I think +one of the things I didn't like is that + + align:start position:0% +one of the things I didn't like is that + + + align:start position:0% +one of the things I didn't like is that +all of the objects are accessible all at + + align:start position:0% +all of the objects are accessible all at + + + align:start position:0% +all of the objects are accessible all at +once. Um, so if it's an apothecary chest + + align:start position:0% +once. Um, so if it's an apothecary chest + + + align:start position:0% +once. Um, so if it's an apothecary chest +with lots of drawers, this was Jason + + align:start position:0% +with lots of drawers, this was Jason + + + align:start position:0% +with lots of drawers, this was Jason +Bean's idea, then you kind of have to do + + align:start position:0% +Bean's idea, then you kind of have to do + + + align:start position:0% +Bean's idea, then you kind of have to do +a little exploring. Um, and maybe the + + align:start position:0% +a little exploring. Um, and maybe the + + + align:start position:0% +a little exploring. Um, and maybe the +rules are in one of those drawers. And + + align:start position:0% +rules are in one of those drawers. And + + + align:start position:0% +rules are in one of those drawers. And +maybe you see the rules first, maybe you + + align:start position:0% +maybe you see the rules first, maybe you + + + align:start position:0% +maybe you see the rules first, maybe you +see the rules way after you've looked at + + align:start position:0% +see the rules way after you've looked at + + + align:start position:0% +see the rules way after you've looked at +a lot of stuff. And then you now you've + + align:start position:0% +a lot of stuff. And then you now you've + + + align:start position:0% +a lot of stuff. And then you now you've +seen all this stuff and played with it + + align:start position:0% +seen all this stuff and played with it + + + align:start position:0% +seen all this stuff and played with it +all and you really like something and + + align:start position:0% +all and you really like something and + + + align:start position:0% +all and you really like something and +now it's like what do I trade? Um + + align:start position:0% +now it's like what do I trade? Um + + + align:start position:0% +now it's like what do I trade? Um +and um and yeah, so I also am trying to + + align:start position:0% +and um and yeah, so I also am trying to + + + align:start position:0% +and um and yeah, so I also am trying to +find a way to give the box a a history + + align:start position:0% +find a way to give the box a a history + + + align:start position:0% +find a way to give the box a a history +as well. I've contemplated some ideas of + + align:start position:0% +as well. I've contemplated some ideas of + + + align:start position:0% +as well. I've contemplated some ideas of +putting in some some kind of clues that + + align:start position:0% +putting in some some kind of clues that + + + align:start position:0% +putting in some some kind of clues that +you could then if you felt if you + + align:start position:0% +you could then if you felt if you + + + align:start position:0% +you could then if you felt if you +thought about it or looked it up, you + + align:start position:0% +thought about it or looked it up, you + + + align:start position:0% +thought about it or looked it up, you +might be able to find a story to this + + align:start position:0% +might be able to find a story to this + + + align:start position:0% +might be able to find a story to this +box. Like if you did an internet search, + + align:start position:0% +box. Like if you did an internet search, + + + align:start position:0% +box. Like if you did an internet search, +you might come upon a fake website. uh + + align:start position:0% +you might come upon a fake website. uh + + + align:start position:0% +you might come upon a fake website. uh +wouldn't be fake. It' just be a website, + + align:start position:0% +wouldn't be fake. It' just be a website, + + + align:start position:0% +wouldn't be fake. It' just be a website, +but a website with a fake story that + + align:start position:0% +but a website with a fake story that + + + align:start position:0% +but a website with a fake story that +kind of tells you a little bit about + + align:start position:0% +kind of tells you a little bit about + + + align:start position:0% +kind of tells you a little bit about +this box and maybe gives you a few more + + align:start position:0% +this box and maybe gives you a few more + + + align:start position:0% +this box and maybe gives you a few more +hooks into what the meaning of this game + + align:start position:0% +hooks into what the meaning of this game + + + align:start position:0% +hooks into what the meaning of this game +or what the inspiration for this game + + align:start position:0% +or what the inspiration for this game + + + align:start position:0% +or what the inspiration for this game +inspiration for this game was. And so + + align:start position:0% +inspiration for this game was. And so + + + align:start position:0% +inspiration for this game was. And so +this is kind of one of my projects that + + align:start position:0% +this is kind of one of my projects that + + + align:start position:0% +this is kind of one of my projects that +I'm working on right now. Like I said, + + align:start position:0% +I'm working on right now. Like I said, + + + align:start position:0% +I'm working on right now. Like I said, +I'm kind of I'm interested in + + align:start position:0% +I'm kind of I'm interested in + + + align:start position:0% +I'm kind of I'm interested in +tangibility, but but you can see where a + + align:start position:0% +tangibility, but but you can see where a + + + align:start position:0% +tangibility, but but you can see where a +lot of the other things that I was + + align:start position:0% +lot of the other things that I was + + + align:start position:0% +lot of the other things that I was +talking about are kind of inspiring + + align:start position:0% +talking about are kind of inspiring + + + align:start position:0% +talking about are kind of inspiring +inspiring this this work. Um and so we + + align:start position:0% +inspiring this this work. Um and so we + + + align:start position:0% +inspiring this this work. Um and so we +kind of come back to that question of + + align:start position:0% +kind of come back to that question of + + + align:start position:0% +kind of come back to that question of +are games art and whether it's even a + + align:start position:0% +are games art and whether it's even a + + + align:start position:0% +are games art and whether it's even a +valid question. We only have five + + align:start position:0% +valid question. We only have five + + + align:start position:0% +valid question. We only have five +minutes. I don't know if you guys have + + align:start position:0% +minutes. I don't know if you guys have + + + align:start position:0% +minutes. I don't know if you guys have +administrative stuff afterwards, but um + + align:start position:0% +administrative stuff afterwards, but um + + + align:start position:0% +administrative stuff afterwards, but um +this is like I said, this is sort of my + + align:start position:0% +this is like I said, this is sort of my + + + align:start position:0% +this is like I said, this is sort of my +viewpoint and I I it's certainly shared + + align:start position:0% +viewpoint and I I it's certainly shared + + + align:start position:0% +viewpoint and I I it's certainly shared +with a lot of other people. Um but it's + + align:start position:0% +with a lot of other people. Um but it's + + + align:start position:0% +with a lot of other people. Um but it's +not um this is not guaranteed truth. + + align:start position:0% +not um this is not guaranteed truth. + + + align:start position:0% +not um this is not guaranteed truth. +It's this is an opinion that I have just + + align:start position:0% +It's this is an opinion that I have just + + + align:start position:0% +It's this is an opinion that I have just +shared. So, um, but any thoughts you + + align:start position:0% +shared. So, um, but any thoughts you + + + align:start position:0% +shared. So, um, but any thoughts you +guys have about this subject or these + + align:start position:0% +guys have about this subject or these + + + align:start position:0% +guys have about this subject or these +ideas of these games or + + align:start position:0% +ideas of these games or + + + align:start position:0% +ideas of these games or +anything at all? + + align:start position:0% +anything at all? + + + align:start position:0% +anything at all? +Yesterday's football game. + + align:start position:0% + + + + align:start position:0% + +>> Well, cool. Well, I hope this was + + align:start position:0% +>> Well, cool. Well, I hope this was + + + align:start position:0% +>> Well, cool. Well, I hope this was +useful. I hope it was helpful. Um, you + + align:start position:0% +useful. I hope it was helpful. Um, you + + + align:start position:0% +useful. I hope it was helpful. Um, you +know, I think it if if at the very least + + align:start position:0% +know, I think it if if at the very least + + + align:start position:0% +know, I think it if if at the very least +it causes you to continue to think + + align:start position:0% +it causes you to continue to think + + + align:start position:0% +it causes you to continue to think +about, you know, your own games that + + align:start position:0% +about, you know, your own games that + + + align:start position:0% +about, you know, your own games that +you're developing and how meaning can be + + align:start position:0% +you're developing and how meaning can be + + + align:start position:0% +you're developing and how meaning can be +embed in in the play that you might not + + align:start position:0% +embed in in the play that you might not + + + align:start position:0% +embed in in the play that you might not +even realize is there. Um, but also just + + align:start position:0% +even realize is there. Um, but also just + + + align:start position:0% +even realize is there. Um, but also just +kind of the possibility space. I I + + align:start position:0% +kind of the possibility space. I I + + + align:start position:0% +kind of the possibility space. I I +really am excited by I'm discouraged by + + align:start position:0% +really am excited by I'm discouraged by + + + align:start position:0% +really am excited by I'm discouraged by +the safe choices that a lot of + + align:start position:0% +the safe choices that a lot of + + + align:start position:0% +the safe choices that a lot of +independent game developers make and + + align:start position:0% +independent game developers make and + + + align:start position:0% +independent game developers make and +excited when some game developers really + + align:start position:0% +excited when some game developers really + + + align:start position:0% +excited when some game developers really +push on the edge. I don't think we have + + align:start position:0% +push on the edge. I don't think we have + + + align:start position:0% +push on the edge. I don't think we have +a I don't think we have a clear + + align:start position:0% +a I don't think we have a clear + + + align:start position:0% +a I don't think we have a clear +understanding of what the rules are or + + align:start position:0% +understanding of what the rules are or + + + align:start position:0% +understanding of what the rules are or +what even constitutes a game or what + + align:start position:0% +what even constitutes a game or what + + + align:start position:0% +what even constitutes a game or what +what degree of interactivity is + + align:start position:0% +what degree of interactivity is + + + align:start position:0% +what degree of interactivity is +appropriate for a you know quote unquote + + align:start position:0% +appropriate for a you know quote unquote + + + align:start position:0% +appropriate for a you know quote unquote +game. And I think I think some of these + + align:start position:0% +game. And I think I think some of these + + + align:start position:0% +game. And I think I think some of these +designers are really testing the waters + + align:start position:0% +designers are really testing the waters + + + align:start position:0% +designers are really testing the waters +of the medium. You know, what can we + + align:start position:0% +of the medium. You know, what can we + + + align:start position:0% +of the medium. You know, what can we +really do with this? You know, where + + align:start position:0% +really do with this? You know, where + + + align:start position:0% +really do with this? You know, where +where can we go? How edgy and satirical + + align:start position:0% +where can we go? How edgy and satirical + + + align:start position:0% +where can we go? How edgy and satirical +and on guard can we be? Um, + + align:start position:0% +and on guard can we be? Um, + + + align:start position:0% +and on guard can we be? Um, +I think that's always good. + + align:start position:0% +I think that's always good. + + + align:start position:0% +I think that's always good. +So, I'm a revolutionary + + align:start position:0% +So, I'm a revolutionary + + + align:start position:0% +So, I'm a revolutionary +crazy person. + + align:start position:0% +crazy person. + + + align:start position:0% +crazy person. +>> Crazy person. + + align:start position:0% +>> Crazy person. + + + align:start position:0% +>> Crazy person. +That's good to hear. + + align:start position:0% + + + + align:start position:0% + +>> Folks, um if folks haven't played uh yet + + align:start position:0% +>> Folks, um if folks haven't played uh yet + + + align:start position:0% +>> Folks, um if folks haven't played uh yet +one word this year, which were some of + + align:start position:0% +one word this year, which were some of + + + align:start position:0% +one word this year, which were some of +the games that uh Abe um worked with the + + align:start position:0% +the games that uh Abe um worked with the + + + align:start position:0% +the games that uh Abe um worked with the +team on over the summer, uh those are on + + align:start position:0% +team on over the summer, uh those are on + + + align:start position:0% +team on over the summer, uh those are on +our gamut website uh just opened 2010 + + align:start position:0% +our gamut website uh just opened 2010 + + + align:start position:0% +our gamut website uh just opened 2010 +and and you see yet one more in Sier + + align:start position:0% +and and you see yet one more in Sier + + + align:start position:0% +and and you see yet one more in Sier +which were booked about this summer. We + + align:start position:0% +which were booked about this summer. We + + + align:start position:0% +which were booked about this summer. We +saw us like try to see some of the + + align:start position:0% +saw us like try to see some of the + + + align:start position:0% +saw us like try to see some of the +digital. + + align:start position:0% +digital. + + + align:start position:0% +digital. +>> Yeah. And please play them and give us + + align:start position:0% +>> Yeah. And please play them and give us + + + align:start position:0% +>> Yeah. And please play them and give us +feedback too, right? Because that's the + + align:start position:0% +feedback too, right? Because that's the + + + align:start position:0% +feedback too, right? Because that's the +other thing like these are not perfect + + align:start position:0% +other thing like these are not perfect + + + align:start position:0% +other thing like these are not perfect +articulations of of game is is the pure + + align:start position:0% +articulations of of game is is the pure + + + align:start position:0% +articulations of of game is is the pure +art form, right? Like we're constantly + + align:start position:0% +art form, right? Like we're constantly + + + align:start position:0% +art form, right? Like we're constantly +evolving and trying to improve and so + + align:start position:0% +evolving and trying to improve and so + + + align:start position:0% +evolving and trying to improve and so +any feedback you can give us on this + + align:start position:0% +any feedback you can give us on this + + + align:start position:0% +any feedback you can give us on this +stuff is greatly appreciated. + + align:start position:0% +stuff is greatly appreciated. + + + align:start position:0% +stuff is greatly appreciated. +>> I have one question. + + align:start position:0% +>> I have one question. + + + align:start position:0% +>> I have one question. +>> Do you still have that box like + + align:start position:0% +>> Do you still have that box like + + + align:start position:0% +>> Do you still have that box like +somewhere? + + align:start position:0% +somewhere? + + + align:start position:0% +somewhere? +>> Yeah. Yeah, it's in my office. Yeah. + + align:start position:0% +>> Yeah. Yeah, it's in my office. Yeah. + + + align:start position:0% +>> Yeah. Yeah, it's in my office. Yeah. +Yeah. Yeah. Totally. Yeah. I have a box + + align:start position:0% +Yeah. Yeah. Totally. Yeah. I have a box + + + align:start position:0% +Yeah. Yeah. Totally. Yeah. I have a box +and I need to I'm I'm So the other part + + align:start position:0% +and I need to I'm I'm So the other part + + + align:start position:0% +and I need to I'm I'm So the other part +of it is is when I do the second version + + align:start position:0% +of it is is when I do the second version + + + align:start position:0% +of it is is when I do the second version +of it in the apothecary kind of chest, + + align:start position:0% +of it in the apothecary kind of chest, + + + align:start position:0% +of it in the apothecary kind of chest, +uh, one thing that's important to me is + + align:start position:0% +uh, one thing that's important to me is + + + align:start position:0% +uh, one thing that's important to me is +that each of the I sort of for the + + align:start position:0% +that each of the I sort of for the + + + align:start position:0% +that each of the I sort of for the +prototype, I just sort of threw some + + align:start position:0% +prototype, I just sort of threw some + + + align:start position:0% +prototype, I just sort of threw some +like reasonably meaningful objects in + + align:start position:0% +like reasonably meaningful objects in + + + align:start position:0% +like reasonably meaningful objects in +there, but I I I want it to be populated + + align:start position:0% +there, but I I I want it to be populated + + + align:start position:0% +there, but I I I want it to be populated +with objects that are personally + + align:start position:0% +with objects that are personally + + + align:start position:0% +with objects that are personally +significant to myself or symbolic to + + align:start position:0% +significant to myself or symbolic to + + + align:start position:0% +significant to myself or symbolic to +myself. and um and populating that box + + align:start position:0% +myself. and um and populating that box + + + align:start position:0% +myself. and um and populating that box +at the outset with meaningful objects I + + align:start position:0% +at the outset with meaningful objects I + + + align:start position:0% +at the outset with meaningful objects I +think is important because it it's you + + align:start position:0% +think is important because it it's you + + + align:start position:0% +think is important because it it's you +know sort of once it's once it's quote + + align:start position:0% +know sort of once it's once it's quote + + + align:start position:0% +know sort of once it's once it's quote +unquote released into the world for play + + align:start position:0% +unquote released into the world for play + + + align:start position:0% +unquote released into the world for play +right then it's it's constantly changing + + align:start position:0% +right then it's it's constantly changing + + + align:start position:0% +right then it's it's constantly changing +and so that first that first instant + + align:start position:0% +and so that first that first instant + + + align:start position:0% +and so that first that first instant +instantiation of the game is is the one + + align:start position:0% +instantiation of the game is is the one + + + align:start position:0% +instantiation of the game is is the one +that is is kind of about me in some sort + + align:start position:0% +that is is kind of about me in some sort + + + align:start position:0% +that is is kind of about me in some sort +of sense and about my experiences and + + align:start position:0% +of sense and about my experiences and + + + align:start position:0% +of sense and about my experiences and +then it becomes the world which is play. + + align:start position:0% +then it becomes the world which is play. + + + align:start position:0% +then it becomes the world which is play. +So, the way that your games kind of + + align:start position:0% +So, the way that your games kind of + + + align:start position:0% +So, the way that your games kind of +reminds me of is I'm pretty sure I heard + + align:start position:0% +reminds me of is I'm pretty sure I heard + + + align:start position:0% +reminds me of is I'm pretty sure I heard +this similar that some person uh had a + + align:start position:0% +this similar that some person uh had a + + + align:start position:0% +this similar that some person uh had a +pen and so he just kept he started with + + align:start position:0% +pen and so he just kept he started with + + + align:start position:0% +pen and so he just kept he started with +a pen and he kept trading and made + + align:start position:0% +a pen and he kept trading and made + + + align:start position:0% +a pen and he kept trading and made +>> red paper. + + align:start position:0% +>> red paper. + + + align:start position:0% +>> red paper. +>> Oh, no. Well, no, no, this is a + + align:start position:0% +>> Oh, no. Well, no, no, this is a + + + align:start position:0% +>> Oh, no. Well, no, no, this is a +different one. Not the red paper clip + + align:start position:0% +different one. Not the red paper clip + + + align:start position:0% +different one. Not the red paper clip +for I heard I think it was someone had + + align:start position:0% +for I heard I think it was someone had + + + align:start position:0% +for I heard I think it was someone had +started with a pen or something and kept + + align:start position:0% +started with a pen or something and kept + + + align:start position:0% +started with a pen or something and kept +trading it and over the course of like a + + align:start position:0% +trading it and over the course of like a + + + align:start position:0% +trading it and over the course of like a +year or two he eventually trade got with + + align:start position:0% +year or two he eventually trade got with + + + align:start position:0% +year or two he eventually trade got with +that init from that initial pen he was + + align:start position:0% +that init from that initial pen he was + + + align:start position:0% +that init from that initial pen he was +able to trade for a house or something. + + align:start position:0% +able to trade for a house or something. + + + align:start position:0% +able to trade for a house or something. +It was okay. + + align:start position:0% +It was okay. + + + align:start position:0% +It was okay. +>> Yeah. No, totally. I mean, and that was + + align:start position:0% +>> Yeah. No, totally. I mean, and that was + + + align:start position:0% +>> Yeah. No, totally. I mean, and that was +like sort of an interesting what I like. + + align:start position:0% +like sort of an interesting what I like. + + + align:start position:0% +like sort of an interesting what I like. +I think it was on eBay, too, right? Or + + align:start position:0% +I think it was on eBay, too, right? Or + + + align:start position:0% +I think it was on eBay, too, right? Or +something like that. And that's even + + align:start position:0% +something like that. And that's even + + + align:start position:0% +something like that. And that's even +using a a pretty well-designed game + + align:start position:0% +using a a pretty well-designed game + + + align:start position:0% +using a a pretty well-designed game +system because eBay is totally a game. + + align:start position:0% +system because eBay is totally a game. + + + align:start position:0% +system because eBay is totally a game. +Um, and using a game system to and + + align:start position:0% +Um, and using a game system to and + + + align:start position:0% +Um, and using a game system to and +subverting the system itself to do + + align:start position:0% +subverting the system itself to do + + + align:start position:0% +subverting the system itself to do +something really kind of interesting. + + align:start position:0% +something really kind of interesting. + + + align:start position:0% +something really kind of interesting. +And so, I mean, yeah, that's a that's a + + align:start position:0% +And so, I mean, yeah, that's a that's a + + + align:start position:0% +And so, I mean, yeah, that's a that's a +really kind of great it's like a game + + align:start position:0% +really kind of great it's like a game + + + align:start position:0% +really kind of great it's like a game +inside of a game, right? And I love + + align:start position:0% +inside of a game, right? And I love + + + align:start position:0% +inside of a game, right? And I love +that. That's it's kind of like the cow + + align:start position:0% +that. That's it's kind of like the cow + + + align:start position:0% +that. That's it's kind of like the cow +clickers, right? like making a game + + align:start position:0% +clickers, right? like making a game + + + align:start position:0% +clickers, right? like making a game +inside of the game that subverts the + + align:start position:0% +inside of the game that subverts the + + + align:start position:0% +inside of the game that subverts the +>> Are you familiar with the concept of + + align:start position:0% +>> Are you familiar with the concept of + + + align:start position:0% +>> Are you familiar with the concept of +geocaching? + + align:start position:0% +geocaching? + + + align:start position:0% +geocaching? +>> Uh because what when I first saw what + + align:start position:0% +>> Uh because what when I first saw what + + + align:start position:0% +>> Uh because what when I first saw what +the game you were talking about that you + + align:start position:0% +the game you were talking about that you + + + align:start position:0% +the game you were talking about that you +designed it really reminded me of it. Uh + + align:start position:0% +designed it really reminded me of it. Uh + + + align:start position:0% +designed it really reminded me of it. Uh +so initially what it was is when GPS's + + align:start position:0% +so initially what it was is when GPS's + + + align:start position:0% +so initially what it was is when GPS's +first came out, people were like, "Oh, + + align:start position:0% +first came out, people were like, "Oh, + + + align:start position:0% +first came out, people were like, "Oh, +hey, this is really cool technology. We + + align:start position:0% +hey, this is really cool technology. We + + + align:start position:0% +hey, this is really cool technology. We +should think of something fun to do with + + align:start position:0% +should think of something fun to do with + + + align:start position:0% +should think of something fun to do with +it." So what they did was uh these + + align:start position:0% +it." So what they did was uh these + + + align:start position:0% +it." So what they did was uh these +people hid started hiding um like empty + + align:start position:0% +people hid started hiding um like empty + + + align:start position:0% +people hid started hiding um like empty +tins of like little trinkets and stuff + + align:start position:0% +tins of like little trinkets and stuff + + + align:start position:0% +tins of like little trinkets and stuff +at various like on hiking trails or + + align:start position:0% +at various like on hiking trails or + + + align:start position:0% +at various like on hiking trails or +other And you would look up the + + align:start position:0% +other And you would look up the + + + align:start position:0% +other And you would look up the +coordinates on your GPS finder and you + + align:start position:0% +coordinates on your GPS finder and you + + + align:start position:0% +coordinates on your GPS finder and you +would find this box and what you would + + align:start position:0% +would find this box and what you would + + + align:start position:0% +would find this box and what you would +do is you you trade a trinket and you + + align:start position:0% +do is you you trade a trinket and you + + + align:start position:0% +do is you you trade a trinket and you +get a trinket. + + align:start position:0% +get a trinket. + + + align:start position:0% +get a trinket. +>> And you keep like traveling to these + + align:start position:0% +>> And you keep like traveling to these + + + align:start position:0% +>> And you keep like traveling to these +other + + align:start position:0% +other + + + align:start position:0% +other +>> Yeah. And in that sense like this this + + align:start position:0% +>> Yeah. And in that sense like this this + + + align:start position:0% +>> Yeah. And in that sense like this this +whole worldwide game becomes really kind + + align:start position:0% +whole worldwide game becomes really kind + + + align:start position:0% +whole worldwide game becomes really kind +of changed. Yeah. You know there's + + align:start position:0% +of changed. Yeah. You know there's + + + align:start position:0% +of changed. Yeah. You know there's +there's there's some sh there's some + + align:start position:0% +there's there's some sh there's some + + + align:start position:0% +there's there's some sh there's some +shared ideas with some location based + + align:start position:0% +shared ideas with some location based + + + align:start position:0% +shared ideas with some location based +games that do some really interesting + + align:start position:0% +games that do some really interesting + + + align:start position:0% +games that do some really interesting +things with with that where um you know + + align:start position:0% +things with with that where um you know + + + align:start position:0% +things with with that where um you know +whether it's alternative reality but but + + align:start position:0% +whether it's alternative reality but but + + + align:start position:0% +whether it's alternative reality but but +maybe not even with a with a narrative. + + align:start position:0% +maybe not even with a with a narrative. + + + align:start position:0% +maybe not even with a with a narrative. +There was one I was reading about um + + align:start position:0% +There was one I was reading about um + + + align:start position:0% +There was one I was reading about um +that was at uh it was like come out and + + align:start position:0% +that was at uh it was like come out and + + + align:start position:0% +that was at uh it was like come out and +play I think in New York City at one + + align:start position:0% +play I think in New York City at one + + + align:start position:0% +play I think in New York City at one +point but it was cruel to be kind. uh it + + align:start position:0% +point but it was cruel to be kind. uh it + + + align:start position:0% +point but it was cruel to be kind. uh it +was called. It was a game where um you + + align:start position:0% +was called. It was a game where um you + + + align:start position:0% +was called. It was a game where um you +don't you don't know who's playing, you + + align:start position:0% +don't you don't know who's playing, you + + + align:start position:0% +don't you don't know who's playing, you +know who's on what team, but you use you + + align:start position:0% +know who's on what team, but you use you + + + align:start position:0% +know who's on what team, but you use you +use you get missions and you get a + + align:start position:0% +use you get missions and you get a + + + align:start position:0% +use you get missions and you get a +weapon that's a compliment like um you + + align:start position:0% +weapon that's a compliment like um you + + + align:start position:0% +weapon that's a compliment like um you +know to kill someone who's on the other + + align:start position:0% +know to kill someone who's on the other + + + align:start position:0% +know to kill someone who's on the other +team, mistake them for a celebrity or + + align:start position:0% +team, mistake them for a celebrity or + + + align:start position:0% +team, mistake them for a celebrity or +something like that, right? And so + + align:start position:0% +something like that, right? And so + + + align:start position:0% +something like that, right? And so +you're using these kind of random acts + + align:start position:0% +you're using these kind of random acts + + + align:start position:0% +you're using these kind of random acts +of kindness, you know, helping someone + + align:start position:0% +of kindness, you know, helping someone + + + align:start position:0% +of kindness, you know, helping someone +across the street and you don't know if + + align:start position:0% +across the street and you don't know if + + + align:start position:0% +across the street and you don't know if +it's like in New York City, so you don't + + align:start position:0% +it's like in New York City, so you don't + + + align:start position:0% +it's like in New York City, so you don't +know if someone's playing the game. So + + align:start position:0% +know if someone's playing the game. So + + + align:start position:0% +know if someone's playing the game. So +now all of a sudden you're kind of + + align:start position:0% +now all of a sudden you're kind of + + + align:start position:0% +now all of a sudden you're kind of +wandering around doing really nice + + align:start position:0% +wandering around doing really nice + + + align:start position:0% +wandering around doing really nice +things for people on the chance that you + + align:start position:0% +things for people on the chance that you + + + align:start position:0% +things for people on the chance that you +know on a hunch that you have that maybe + + align:start position:0% +know on a hunch that you have that maybe + + + align:start position:0% +know on a hunch that you have that maybe +they're playing the game and maybe + + align:start position:0% +they're playing the game and maybe + + + align:start position:0% +they're playing the game and maybe +they're not. And so you just help + + align:start position:0% +they're not. And so you just help + + + align:start position:0% +they're not. And so you just help +somebody across the street which is + + align:start position:0% +somebody across the street which is + + + align:start position:0% +somebody across the street which is +totally nice and and it kind of comes to + + align:start position:0% +totally nice and and it kind of comes to + + + align:start position:0% +totally nice and and it kind of comes to +this massive conclusion where you just + + align:start position:0% +this massive conclusion where you just + + + align:start position:0% +this massive conclusion where you just +have these two giant teams who meet up + + align:start position:0% +have these two giant teams who meet up + + + align:start position:0% +have these two giant teams who meet up +at a location to nice each other to + + align:start position:0% +at a location to nice each other to + + + align:start position:0% +at a location to nice each other to +death basically. Um and so you know + + align:start position:0% +death basically. Um and so you know + + + align:start position:0% +death basically. Um and so you know +there there's a lot of really really + + align:start position:0% +there there's a lot of really really + + + align:start position:0% +there there's a lot of really really +kind of interesting stuff especially in + + align:start position:0% +kind of interesting stuff especially in + + + align:start position:0% +kind of interesting stuff especially in +the the kind of location based + + align:start position:0% +the the kind of location based + + + align:start position:0% +the the kind of location based +>> realm. Big big games are really cool. + + align:start position:0% +>> realm. Big big games are really cool. + + + align:start position:0% +>> realm. Big big games are really cool. +There's a lot of people doing really + + align:start position:0% +There's a lot of people doing really + + + align:start position:0% +There's a lot of people doing really +neat stuff with with big games. + + align:start position:0% +neat stuff with with big games. + + + align:start position:0% +neat stuff with with big games. +>> Yeah. So, I I I think like in particular + + align:start position:0% +>> Yeah. So, I I I think like in particular + + + align:start position:0% +>> Yeah. So, I I I think like in particular +with you know, the box and the + + align:start position:0% +with you know, the box and the + + + align:start position:0% +with you know, the box and the +geocaching idea, it's and and you know, + + align:start position:0% +geocaching idea, it's and and you know, + + + align:start position:0% +geocaching idea, it's and and you know, +talking about the paperclip for a house + + align:start position:0% +talking about the paperclip for a house + + + align:start position:0% +talking about the paperclip for a house +thing. + + align:start position:0% +thing. + + + align:start position:0% +thing. +>> It's really interesting like what how + + align:start position:0% +>> It's really interesting like what how + + + align:start position:0% +>> It's really interesting like what how +people value things. + + align:start position:0% +people value things. + + + align:start position:0% +people value things. +>> Yeah. + + align:start position:0% +>> Yeah. + + + align:start position:0% +>> Yeah. +>> Like in particular, you know, you have + + align:start position:0% +>> Like in particular, you know, you have + + + align:start position:0% +>> Like in particular, you know, you have +this very vague rule in it that just + + align:start position:0% +this very vague rule in it that just + + + align:start position:0% +this very vague rule in it that just +says, you know, something of of equal + + align:start position:0% +says, you know, something of of equal + + + align:start position:0% +says, you know, something of of equal +value. Like what does it actually mean? + + align:start position:0% +value. Like what does it actually mean? + + + align:start position:0% +value. Like what does it actually mean? +>> Value or + + align:start position:0% +>> Value or + + + align:start position:0% +>> Value or +>> Yeah, exactly. It's kind of interesting + + align:start position:0% +>> Yeah, exactly. It's kind of interesting + + + align:start position:0% +>> Yeah, exactly. It's kind of interesting +like what someone is willing to trade + + align:start position:0% +like what someone is willing to trade + + + align:start position:0% +like what someone is willing to trade +for for something else. + + align:start position:0% +for for something else. + + + align:start position:0% +for for something else. +>> Yeah. And those are those are the kind + + align:start position:0% +>> Yeah. And those are those are the kind + + + align:start position:0% +>> Yeah. And those are those are the kind +of implicit rules like you see in 16 + + align:start position:0% +of implicit rules like you see in 16 + + + align:start position:0% +of implicit rules like you see in 16 +tons, right? Where it's like what + + align:start position:0% +tons, right? Where it's like what + + + align:start position:0% +tons, right? Where it's like what +happens with the money, you know, and + + align:start position:0% +happens with the money, you know, and + + + align:start position:0% +happens with the money, you know, and +and and that's, you know, Jason me + + align:start position:0% +and and that's, you know, Jason me + + + align:start position:0% +and and that's, you know, Jason me +really pointed out because he was + + align:start position:0% +really pointed out because he was + + + align:start position:0% +really pointed out because he was +thinking about value when he was doing + + align:start position:0% +thinking about value when he was doing + + + align:start position:0% +thinking about value when he was doing +the training and it's such a good word, + + align:start position:0% +the training and it's such a good word, + + + align:start position:0% +the training and it's such a good word, +right? Because value is such a different + + align:start position:0% +right? Because value is such a different + + + align:start position:0% +right? Because value is such a different +thing to different people and someone + + align:start position:0% +thing to different people and someone + + + align:start position:0% +thing to different people and someone +might see the like the the flash card + + align:start position:0% +might see the like the the flash card + + + align:start position:0% +might see the like the the flash card +for the DS, right, which has a very + + align:start position:0% +for the DS, right, which has a very + + + align:start position:0% +for the DS, right, which has a very +clear higher monetary value than than an + + align:start position:0% +clear higher monetary value than than an + + + align:start position:0% +clear higher monetary value than than an +etch sketch. Um, and yet maybe you + + align:start position:0% +etch sketch. Um, and yet maybe you + + + align:start position:0% +etch sketch. Um, and yet maybe you +played with an etch sketch when you were + + align:start position:0% +played with an etch sketch when you were + + + align:start position:0% +played with an etch sketch when you were +a kid and all of a sudden it floods back + + align:start position:0% +a kid and all of a sudden it floods back + + + align:start position:0% +a kid and all of a sudden it floods back +these memories that you have. Um, + + align:start position:0% +these memories that you have. Um, + + + align:start position:0% +these memories that you have. Um, +there's also there's another component + + align:start position:0% +there's also there's another component + + + align:start position:0% +there's also there's another component +to it that I didn't really talk about, + + align:start position:0% +to it that I didn't really talk about, + + + align:start position:0% +to it that I didn't really talk about, +which is like the sacrificing of an + + align:start position:0% +which is like the sacrificing of an + + + align:start position:0% +which is like the sacrificing of an +object. And and I think too that it's + + align:start position:0% +object. And and I think too that it's + + + align:start position:0% +object. And and I think too that it's +it's we we tend to be beholden to our + + align:start position:0% +it's we we tend to be beholden to our + + + align:start position:0% +it's we we tend to be beholden to our +material objects um too much um in in in + + align:start position:0% +material objects um too much um in in in + + + align:start position:0% +material objects um too much um in in in +giving it up in in sacrificing it to + + align:start position:0% +giving it up in in sacrificing it to + + + align:start position:0% +giving it up in in sacrificing it to +this game so that you don't have it + + align:start position:0% +this game so that you don't have it + + + align:start position:0% +this game so that you don't have it +anymore. If it's something of personal + + align:start position:0% +anymore. If it's something of personal + + + align:start position:0% +anymore. If it's something of personal +significance, you're you're letting go + + align:start position:0% +significance, you're you're letting go + + + align:start position:0% +significance, you're you're letting go +and and being able to say, "Okay, the + + align:start position:0% +and and being able to say, "Okay, the + + + align:start position:0% +and and being able to say, "Okay, the +memory is one thing. I don't need to." + + align:start position:0% +memory is one thing. I don't need to." + + + align:start position:0% +memory is one thing. I don't need to." +And that's that's how it relates a bit + + align:start position:0% +And that's that's how it relates a bit + + + align:start position:0% +And that's that's how it relates a bit +back to Citizen Kane, which is a movie + + align:start position:0% +back to Citizen Kane, which is a movie + + + align:start position:0% +back to Citizen Kane, which is a movie +you should see because it is good. + + align:start position:0% +you should see because it is good. + + + align:start position:0% +you should see because it is good. +It's everything they said it is, + + align:start position:0% +It's everything they said it is, + + + align:start position:0% +It's everything they said it is, +>> depending on who they are. + + align:start position:0% + + + + align:start position:0% + +>> Cool. Thanks, guys. + + align:start position:0% +>> Cool. Thanks, guys. + + + align:start position:0% +>> Cool. Thanks, guys. +>> Thanks. \ No newline at end of file diff --git a/yP1S37BiEsQ.txt b/yP1S37BiEsQ.txt new file mode 100644 index 0000000000000000000000000000000000000000..e2b601afaabe141f10d0d4e41ee4f4d2a63c463c --- /dev/null +++ b/yP1S37BiEsQ.txt @@ -0,0 +1,13131 @@ +align:start position:0% + +The following content is provided under + + align:start position:0% +The following content is provided under + + + align:start position:0% +The following content is provided under +a Creative Common License. Your support + + align:start position:0% +a Creative Common License. Your support + + + align:start position:0% +a Creative Common License. Your support +will help MIT Open Courseware continue + + align:start position:0% +will help MIT Open Courseware continue + + + align:start position:0% +will help MIT Open Courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free. To make a donation + + align:start position:0% +resources for free. To make a donation + + + align:start position:0% +resources for free. To make a donation +or to view additional materials from + + align:start position:0% +or to view additional materials from + + + align:start position:0% +or to view additional materials from +hundreds of MIT courses, visit MIT + + align:start position:0% +hundreds of MIT courses, visit MIT + + + align:start position:0% +hundreds of MIT courses, visit MIT +OpenCourseware at ocw.mit.edu. + + align:start position:0% + + + + align:start position:0% + +It's because if I was not, this would be + + align:start position:0% +It's because if I was not, this would be + + + align:start position:0% +It's because if I was not, this would be +basically the last topic we would ever + + align:start position:0% +basically the last topic we would ever + + + align:start position:0% +basically the last topic we would ever +see. And this is arguably probably the + + align:start position:0% +see. And this is arguably probably the + + + align:start position:0% +see. And this is arguably probably the +most important topic in statistics or at + + align:start position:0% +most important topic in statistics or at + + + align:start position:0% +most important topic in statistics or at +least that's probably the reason why + + align:start position:0% +least that's probably the reason why + + + align:start position:0% +least that's probably the reason why +most of you are taking this class + + align:start position:0% +most of you are taking this class + + + align:start position:0% +most of you are taking this class +because regression + + align:start position:0% +because regression + + + align:start position:0% +because regression +implies prediction and prediction is + + align:start position:0% +implies prediction and prediction is + + + align:start position:0% +implies prediction and prediction is +what people are all after now, right? + + align:start position:0% +what people are all after now, right? + + + align:start position:0% +what people are all after now, right? +You don't need to understand what the + + align:start position:0% +You don't need to understand what the + + + align:start position:0% +You don't need to understand what the +model for the financial market is. If + + align:start position:0% +model for the financial market is. If + + + align:start position:0% +model for the financial market is. If +you actually have a formula to predict + + align:start position:0% +you actually have a formula to predict + + + align:start position:0% +you actually have a formula to predict +what uh the stock prices are going to be + + align:start position:0% +what uh the stock prices are going to be + + + align:start position:0% +what uh the stock prices are going to be +tomorrow and regression in a way allows + + align:start position:0% +tomorrow and regression in a way allows + + + align:start position:0% +tomorrow and regression in a way allows +us to do that. And we'll start with a + + align:start position:0% +us to do that. And we'll start with a + + + align:start position:0% +us to do that. And we'll start with a +very simple version of regression which + + align:start position:0% +very simple version of regression which + + + align:start position:0% +very simple version of regression which +is linear regression which is the most + + align:start position:0% +is linear regression which is the most + + + align:start position:0% +is linear regression which is the most +standard one. And then we'll move on to + + align:start position:0% +standard one. And then we'll move on to + + + align:start position:0% +standard one. And then we'll move on to +slightly more advanced notions such as + + align:start position:0% +slightly more advanced notions such as + + + align:start position:0% +slightly more advanced notions such as +nonparametric regression. At least we're + + align:start position:0% +nonparametric regression. At least we're + + + align:start position:0% +nonparametric regression. At least we're +going to see the principles behind it. + + align:start position:0% +going to see the principles behind it. + + + align:start position:0% +going to see the principles behind it. +And uh I'll touch upon a little bit of + + align:start position:0% +And uh I'll touch upon a little bit of + + + align:start position:0% +And uh I'll touch upon a little bit of +high dimensional regression which is + + align:start position:0% +high dimensional regression which is + + + align:start position:0% +high dimensional regression which is +what people are doing today. + + align:start position:0% +what people are doing today. + + + align:start position:0% +what people are doing today. +So the goal of regression is to try to + + align:start position:0% +So the goal of regression is to try to + + + align:start position:0% +So the goal of regression is to try to +predict one variable based on another + + align:start position:0% +predict one variable based on another + + + align:start position:0% +predict one variable based on another +variable. All right. So here the + + align:start position:0% +variable. All right. So here the + + + align:start position:0% +variable. All right. So here the +notation is very important. It's + + align:start position:0% +notation is very important. It's + + + align:start position:0% +notation is very important. It's +extremely standard. It goes from one uh + + align:start position:0% +extremely standard. It goes from one uh + + + align:start position:0% +extremely standard. It goes from one uh +it goes everywhere essentially and + + align:start position:0% +it goes everywhere essentially and + + + align:start position:0% +it goes everywhere essentially and +essentially you have you're trying to + + align:start position:0% +essentially you have you're trying to + + + align:start position:0% +essentially you have you're trying to +explain y as a function of x. Okay, + + align:start position:0% +explain y as a function of x. Okay, + + + align:start position:0% +explain y as a function of x. Okay, +which is the usual yals f ofx question + + align:start position:0% +which is the usual yals f ofx question + + + align:start position:0% +which is the usual yals f ofx question +except that you know if you look at a + + align:start position:0% +except that you know if you look at a + + + align:start position:0% +except that you know if you look at a +calculus class, people tell you yals f + + align:start position:0% +calculus class, people tell you yals f + + + align:start position:0% +calculus class, people tell you yals f +ofx + + align:start position:0% +ofx + + + align:start position:0% +ofx +and they give you a specific form for f + + align:start position:0% +and they give you a specific form for f + + + align:start position:0% +and they give you a specific form for f +and then you do something. Here we're + + align:start position:0% +and then you do something. Here we're + + + align:start position:0% +and then you do something. Here we're +just going to try to estimate what this + + align:start position:0% +just going to try to estimate what this + + + align:start position:0% +just going to try to estimate what this +link function is. And this is why we + + align:start position:0% +link function is. And this is why we + + + align:start position:0% +link function is. And this is why we +often call uh y the explained variable + + align:start position:0% +often call uh y the explained variable + + + align:start position:0% +often call uh y the explained variable +and x the explanatory variable. All + + align:start position:0% +and x the explanatory variable. All + + + align:start position:0% +and x the explanatory variable. All +right. So um we're statisticians. So we + + align:start position:0% +right. So um we're statisticians. So we + + + align:start position:0% +right. So um we're statisticians. So we +start with data. All right. And what + + align:start position:0% +start with data. All right. And what + + + align:start position:0% +start with data. All right. And what +does our data look like? Well, it looks + + align:start position:0% +does our data look like? Well, it looks + + + align:start position:0% +does our data look like? Well, it looks +like a bunch of input output to this + + align:start position:0% +like a bunch of input output to this + + + align:start position:0% +like a bunch of input output to this +relationship. All right. So we have a + + align:start position:0% +relationship. All right. So we have a + + + align:start position:0% +relationship. All right. So we have a +bunch of xi yi. Those are pairs. And I + + align:start position:0% +bunch of xi yi. Those are pairs. And I + + + align:start position:0% +bunch of xi yi. Those are pairs. And I +can do a scatter plot of those guys. + + align:start position:0% +can do a scatter plot of those guys. + + + align:start position:0% +can do a scatter plot of those guys. +Right? So each point here has a x + + align:start position:0% +Right? So each point here has a x + + + align:start position:0% +Right? So each point here has a x +coordinate which is x i and a + + align:start position:0% +coordinate which is x i and a + + + align:start position:0% +coordinate which is x i and a +ycoordinate which is y i. And here I + + align:start position:0% +ycoordinate which is y i. And here I + + + align:start position:0% +ycoordinate which is y i. And here I +have a bunch of end points and I just + + align:start position:0% +have a bunch of end points and I just + + + align:start position:0% +have a bunch of end points and I just +draw them like that. Now if so the + + align:start position:0% +draw them like that. Now if so the + + + align:start position:0% +draw them like that. Now if so the +functions we're going to be interested + + align:start position:0% +functions we're going to be interested + + + align:start position:0% +functions we're going to be interested +in are often function of the form y = a + + align:start position:0% +in are often function of the form y = a + + + align:start position:0% +in are often function of the form y = a ++ b * x. Okay. And that means that this + + align:start position:0% ++ b * x. Okay. And that means that this + + + align:start position:0% ++ b * x. Okay. And that means that this +function looks like this. + + align:start position:0% + + + + align:start position:0% + +So if I do x and y, this function looks + + align:start position:0% +So if I do x and y, this function looks + + + align:start position:0% +So if I do x and y, this function looks +exactly like a line and clearly those + + align:start position:0% +exactly like a line and clearly those + + + align:start position:0% +exactly like a line and clearly those +points are not on a line and it will + + align:start position:0% +points are not on a line and it will + + + align:start position:0% +points are not on a line and it will +basically never happen that those points + + align:start position:0% +basically never happen that those points + + + align:start position:0% +basically never happen that those points +are on a line. There's a famous uh + + align:start position:0% +are on a line. There's a famous uh + + + align:start position:0% +are on a line. There's a famous uh +t-shirt from I think UC Berkeley stats + + align:start position:0% +t-shirt from I think UC Berkeley stats + + + align:start position:0% +t-shirt from I think UC Berkeley stats +department that shows this picture and + + align:start position:0% +department that shows this picture and + + + align:start position:0% +department that shows this picture and +put a line in between them like we're + + align:start position:0% +put a line in between them like we're + + + align:start position:0% +put a line in between them like we're +going to see it and it says uh + + align:start position:0% +going to see it and it says uh + + + align:start position:0% +going to see it and it says uh +statisticians so many points and you + + align:start position:0% +statisticians so many points and you + + + align:start position:0% +statisticians so many points and you +still managed to miss all of them and uh + + align:start position:0% +still managed to miss all of them and uh + + + align:start position:0% +still managed to miss all of them and uh +and so basically essentially we don't + + align:start position:0% +and so basically essentially we don't + + + align:start position:0% +and so basically essentially we don't +believe that this relationship y is + + align:start position:0% +believe that this relationship y is + + + align:start position:0% +believe that this relationship y is +equal to a plus bx is true but maybe up + + align:start position:0% +equal to a plus bx is true but maybe up + + + align:start position:0% +equal to a plus bx is true but maybe up +to some noise and that's where the + + align:start position:0% +to some noise and that's where the + + + align:start position:0% +to some noise and that's where the +statistics is going to come into play. + + align:start position:0% +statistics is going to come into play. + + + align:start position:0% +statistics is going to come into play. +there's going to be some random noise + + align:start position:0% +there's going to be some random noise + + + align:start position:0% +there's going to be some random noise +that's going to play out and hopefully + + align:start position:0% +that's going to play out and hopefully + + + align:start position:0% +that's going to play out and hopefully +the noise is going to be spread out + + align:start position:0% +the noise is going to be spread out + + + align:start position:0% +the noise is going to be spread out +evenly so that we can average it uh if + + align:start position:0% +evenly so that we can average it uh if + + + align:start position:0% +evenly so that we can average it uh if +we have enough points average it out. + + align:start position:0% +we have enough points average it out. + + + align:start position:0% +we have enough points average it out. +Okay. And so this epsilon here is not + + align:start position:0% +Okay. And so this epsilon here is not + + + align:start position:0% +Okay. And so this epsilon here is not +necessarily due to randomness but again + + align:start position:0% +necessarily due to randomness but again + + + align:start position:0% +necessarily due to randomness but again +just like we did modeling in the first + + align:start position:0% +just like we did modeling in the first + + + align:start position:0% +just like we did modeling in the first +place it essentially accounts for + + align:start position:0% +place it essentially accounts for + + + align:start position:0% +place it essentially accounts for +everything we don't understand about + + align:start position:0% +everything we don't understand about + + + align:start position:0% +everything we don't understand about +this relationship. All right. So for + + align:start position:0% +this relationship. All right. So for + + + align:start position:0% +this relationship. All right. So for +example + + align:start position:0% +example + + + align:start position:0% +example +uh uh so here I'm not going to be uh so + + align:start position:0% +uh uh so here I'm not going to be uh so + + + align:start position:0% +uh uh so here I'm not going to be uh so +okay give me one second. So uh I'll see + + align:start position:0% +okay give me one second. So uh I'll see + + + align:start position:0% +okay give me one second. So uh I'll see +we'll see an example in a second. But + + align:start position:0% +we'll see an example in a second. But + + + align:start position:0% +we'll see an example in a second. But +the idea here is that if you have data + + align:start position:0% +the idea here is that if you have data + + + align:start position:0% +the idea here is that if you have data +and if you believe that it's of the form + + align:start position:0% +and if you believe that it's of the form + + + align:start position:0% +and if you believe that it's of the form +a plus bx plus some noise, you're trying + + align:start position:0% +a plus bx plus some noise, you're trying + + + align:start position:0% +a plus bx plus some noise, you're trying +to find the line that will explain your + + align:start position:0% +to find the line that will explain your + + + align:start position:0% +to find the line that will explain your +data the best. Right? In the terminology + + align:start position:0% +data the best. Right? In the terminology + + + align:start position:0% +data the best. Right? In the terminology +we've been using before. This would be + + align:start position:0% +we've been using before. This would be + + + align:start position:0% +we've been using before. This would be +the most likely line that explains the + + align:start position:0% +the most likely line that explains the + + + align:start position:0% +the most likely line that explains the +data. So we can see that it's lately + + align:start position:0% +data. So we can see that it's lately + + + align:start position:0% +data. So we can see that it's lately +we've just added another dimension to + + align:start position:0% +we've just added another dimension to + + + align:start position:0% +we've just added another dimension to +our statistical problem. We don't have + + align:start position:0% +our statistical problem. We don't have + + + align:start position:0% +our statistical problem. We don't have +just x's, but we have y's, and we're + + align:start position:0% +just x's, but we have y's, and we're + + + align:start position:0% +just x's, but we have y's, and we're +trying to find the most likely + + align:start position:0% +trying to find the most likely + + + align:start position:0% +trying to find the most likely +explanation of the relationship between + + align:start position:0% +explanation of the relationship between + + + align:start position:0% +explanation of the relationship between +y and x. All right? And so + + align:start position:0% +y and x. All right? And so + + + align:start position:0% +y and x. All right? And so +in practice, the way it's going to look + + align:start position:0% +in practice, the way it's going to look + + + align:start position:0% +in practice, the way it's going to look +like is that we're going to have + + align:start position:0% +like is that we're going to have + + + align:start position:0% +like is that we're going to have +basically two parameters to find the + + align:start position:0% +basically two parameters to find the + + + align:start position:0% +basically two parameters to find the +slope b and the intercept a. And given + + align:start position:0% +slope b and the intercept a. And given + + + align:start position:0% +slope b and the intercept a. And given +data, the goal is going to be to try to + + align:start position:0% +data, the goal is going to be to try to + + + align:start position:0% +data, the goal is going to be to try to +find the best possible line. All right? + + align:start position:0% +find the best possible line. All right? + + + align:start position:0% +find the best possible line. All right? +So what we're going to find is not + + align:start position:0% +So what we're going to find is not + + + align:start position:0% +So what we're going to find is not +exactly A and B the ones that actually + + align:start position:0% +exactly A and B the ones that actually + + + align:start position:0% +exactly A and B the ones that actually +generate the data but some estim est est + + align:start position:0% + + + + align:start position:0% +est est est est est est est est est est +est est est est est est est est est est + + align:start position:0% + + + + align:start position:0% +est est est est est est est est est est +est est est est est est est estimators + + align:start position:0% +est est est est est est est estimators + + + align:start position:0% +est est est est est est est estimators +of those parameters a hat and b hat + + align:start position:0% +of those parameters a hat and b hat + + + align:start position:0% +of those parameters a hat and b hat +constructed from the data all right so + + align:start position:0% +constructed from the data all right so + + + align:start position:0% +constructed from the data all right so +we'll see that more generally but we're + + align:start position:0% +we'll see that more generally but we're + + + align:start position:0% +we'll see that more generally but we're +not going to go too much in the details + + align:start position:0% +not going to go too much in the details + + + align:start position:0% +not going to go too much in the details +of this it there's actually quite a bit + + align:start position:0% +of this it there's actually quite a bit + + + align:start position:0% +of this it there's actually quite a bit +that you can understand if you do what's + + align:start position:0% +that you can understand if you do what's + + + align:start position:0% +that you can understand if you do what's +called univariate regression when x is + + align:start position:0% +called univariate regression when x is + + + align:start position:0% +called univariate regression when x is +actually a real valued uh random + + align:start position:0% +actually a real valued uh random + + + align:start position:0% +actually a real valued uh random +variable so when this happens this is + + align:start position:0% +variable so when this happens this is + + + align:start position:0% +variable so when this happens this is +called univariate regression + + align:start position:0% +called univariate regression + + + align:start position:0% +called univariate regression +[Applause] + + align:start position:0% + + + + align:start position:0% + +And when X is in RP + + align:start position:0% +And when X is in RP + + + align:start position:0% +And when X is in RP +for P larger than or equal to two, this + + align:start position:0% +for P larger than or equal to two, this + + + align:start position:0% +for P larger than or equal to two, this +is called multivariate regression. + + align:start position:0% + + + + align:start position:0% + +Okay. And so here we're just trying to + + align:start position:0% +Okay. And so here we're just trying to + + + align:start position:0% +Okay. And so here we're just trying to +explain y is a + b x plus epsilon. And + + align:start position:0% +explain y is a + b x plus epsilon. And + + + align:start position:0% +explain y is a + b x plus epsilon. And +here we're going to have something more + + align:start position:0% +here we're going to have something more + + + align:start position:0% +here we're going to have something more +complicated. We're going to have y, + + align:start position:0% +complicated. We're going to have y, + + + align:start position:0% +complicated. We're going to have y, +which is equal to a + b1 x1 + b2 + + align:start position:0% +which is equal to a + b1 x1 + b2 + + + align:start position:0% +which is equal to a + b1 x1 + b2 +x2 + b p xp + + align:start position:0% +x2 + b p xp + + + align:start position:0% +x2 + b p xp +plus epsilon where x is equal to the + + align:start position:0% +plus epsilon where x is equal to the + + + align:start position:0% +plus epsilon where x is equal to the +coordinates of x are given by x1 2xp or + + align:start position:0% +coordinates of x are given by x1 2xp or + + + align:start position:0% +coordinates of x are given by x1 2xp or +p. Okay, so it's still linear, right? + + align:start position:0% +p. Okay, so it's still linear, right? + + + align:start position:0% +p. Okay, so it's still linear, right? +they still add all the coordinates of x + + align:start position:0% +they still add all the coordinates of x + + + align:start position:0% +they still add all the coordinates of x +with a coefficient in front of them but + + align:start position:0% +with a coefficient in front of them but + + + align:start position:0% +with a coefficient in front of them but +it's a bit more complicated than just + + align:start position:0% +it's a bit more complicated than just + + + align:start position:0% +it's a bit more complicated than just +one coefficient for one coordinate of x. + + align:start position:0% +one coefficient for one coordinate of x. + + + align:start position:0% +one coefficient for one coordinate of x. +Okay. So we'll come back to multivate + + align:start position:0% +Okay. So we'll come back to multivate + + + align:start position:0% +Okay. So we'll come back to multivate +regression. Uh there's a of course you + + align:start position:0% +regression. Uh there's a of course you + + + align:start position:0% +regression. Uh there's a of course you +can write this as a uh uh xrpose b + + align:start position:0% +can write this as a uh uh xrpose b + + + align:start position:0% +can write this as a uh uh xrpose b +right. So this entire thing here + + align:start position:0% + + + + align:start position:0% + +this linear combination is of the form + + align:start position:0% +this linear combination is of the form + + + align:start position:0% +this linear combination is of the form +xrpose b where b is the vector that has + + align:start position:0% +xrpose b where b is the vector that has + + + align:start position:0% +xrpose b where b is the vector that has +coordinates b1 to bp. + + align:start position:0% +coordinates b1 to bp. + + + align:start position:0% +coordinates b1 to bp. +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +Uh sorry here it's in our d + + align:start position:0% +Uh sorry here it's in our d + + + align:start position:0% +Uh sorry here it's in our d +p is the natural notation. + + align:start position:0% +p is the natural notation. + + + align:start position:0% +p is the natural notation. +All right. So our goal here in the + + align:start position:0% +All right. So our goal here in the + + + align:start position:0% +All right. So our goal here in the +univariate one is to try to write a + + align:start position:0% +univariate one is to try to write a + + + align:start position:0% +univariate one is to try to write a +model make sense of this little twiddle + + align:start position:0% +model make sense of this little twiddle + + + align:start position:0% +model make sense of this little twiddle +here essentially from a statistical + + align:start position:0% +here essentially from a statistical + + + align:start position:0% +here essentially from a statistical +modeling question is going to be able to + + align:start position:0% +modeling question is going to be able to + + + align:start position:0% +modeling question is going to be able to +the question is going to be what + + align:start position:0% +the question is going to be what + + + align:start position:0% +the question is going to be what +distributional assumptions do you want + + align:start position:0% +distributional assumptions do you want + + + align:start position:0% +distributional assumptions do you want +to put on epsilon are you going to say + + align:start position:0% +to put on epsilon are you going to say + + + align:start position:0% +to put on epsilon are you going to say +they're Gaussian or you going to say + + align:start position:0% +they're Gaussian or you going to say + + + align:start position:0% +they're Gaussian or you going to say +they are + + align:start position:0% +they are + + + align:start position:0% +they are +binomial uh + + align:start position:0% + + + + align:start position:0% + +okay um are you going to say they're + + align:start position:0% +okay um are you going to say they're + + + align:start position:0% +okay um are you going to say they're +binomial? Are you going to say they're + + align:start position:0% +binomial? Are you going to say they're + + + align:start position:0% +binomial? Are you going to say they're +Bernly? Uh so that's going to be uh what + + align:start position:0% +Bernly? Uh so that's going to be uh what + + + align:start position:0% +Bernly? Uh so that's going to be uh what +we're going to make sense. And then + + align:start position:0% +we're going to make sense. And then + + + align:start position:0% +we're going to make sense. And then +we're going to try to find a method to + + align:start position:0% +we're going to try to find a method to + + + align:start position:0% +we're going to try to find a method to +estimate A and B. And then maybe we're + + align:start position:0% +estimate A and B. And then maybe we're + + + align:start position:0% +estimate A and B. And then maybe we're +going to try to do some inference about + + align:start position:0% +going to try to do some inference about + + + align:start position:0% +going to try to do some inference about +A and B. Maybe test if A and B take + + align:start position:0% +A and B. Maybe test if A and B take + + + align:start position:0% +A and B. Maybe test if A and B take +certain values if they're less than + + align:start position:0% +certain values if they're less than + + + align:start position:0% +certain values if they're less than +something. Maybe find some confidence + + align:start position:0% +something. Maybe find some confidence + + + align:start position:0% +something. Maybe find some confidence +regions for A and B. All right. + + align:start position:0% +regions for A and B. All right. + + + align:start position:0% +regions for A and B. All right. +So why would you want to do this? Well, + + align:start position:0% +So why would you want to do this? Well, + + + align:start position:0% +So why would you want to do this? Well, +I'm sure all of you have an application + + align:start position:0% +I'm sure all of you have an application + + + align:start position:0% +I'm sure all of you have an application +why. If I give you some X, you're trying + + align:start position:0% +why. If I give you some X, you're trying + + + align:start position:0% +why. If I give you some X, you're trying +to predict what Y is. Machine learning + + align:start position:0% +to predict what Y is. Machine learning + + + align:start position:0% +to predict what Y is. Machine learning +is all about doing this, right? Without + + align:start position:0% +is all about doing this, right? Without + + + align:start position:0% +is all about doing this, right? Without +maybe trying to even understand the + + align:start position:0% +maybe trying to even understand the + + + align:start position:0% +maybe trying to even understand the +physics behind this. They're saying, + + align:start position:0% +physics behind this. They're saying, + + + align:start position:0% +physics behind this. They're saying, +well, you give me a bag of words. I want + + align:start position:0% +well, you give me a bag of words. I want + + + align:start position:0% +well, you give me a bag of words. I want +to understand whether it's going to be a + + align:start position:0% +to understand whether it's going to be a + + + align:start position:0% +to understand whether it's going to be a +spam or not. You give me a bunch of + + align:start position:0% +spam or not. You give me a bunch of + + + align:start position:0% +spam or not. You give me a bunch of +indic economic indicators. I want you to + + align:start position:0% +indic economic indicators. I want you to + + + align:start position:0% +indic economic indicators. I want you to +tell me how much I should be selling my + + align:start position:0% +tell me how much I should be selling my + + + align:start position:0% +tell me how much I should be selling my +car for. uh you give me a bunch of uh uh + + align:start position:0% +car for. uh you give me a bunch of uh uh + + + align:start position:0% +car for. uh you give me a bunch of uh uh +uh measurements on some patient. I want + + align:start position:0% +uh measurements on some patient. I want + + + align:start position:0% +uh measurements on some patient. I want +you to predict how this person is going + + align:start position:0% +you to predict how this person is going + + + align:start position:0% +you to predict how this person is going +to respond to my drug and things like + + align:start position:0% +to respond to my drug and things like + + + align:start position:0% +to respond to my drug and things like +this. All right? And so + + align:start position:0% +this. All right? And so + + + align:start position:0% +this. All right? And so +often we actually don't have much + + align:start position:0% +often we actually don't have much + + + align:start position:0% +often we actually don't have much +modeling intuition about what the + + align:start position:0% +modeling intuition about what the + + + align:start position:0% +modeling intuition about what the +relationship between X and Y is. And + + align:start position:0% +relationship between X and Y is. And + + + align:start position:0% +relationship between X and Y is. And +this linear thing is basically the + + align:start position:0% +this linear thing is basically the + + + align:start position:0% +this linear thing is basically the +simplest function we can think of. + + align:start position:0% +simplest function we can think of. + + + align:start position:0% +simplest function we can think of. +Arguably + + align:start position:0% +Arguably + + + align:start position:0% +Arguably +linear functions are the simplest + + align:start position:0% +linear functions are the simplest + + + align:start position:0% +linear functions are the simplest +functions that are not trivial. + + align:start position:0% +functions that are not trivial. + + + align:start position:0% +functions that are not trivial. +Otherwise, we would just say, well, + + align:start position:0% +Otherwise, we would just say, well, + + + align:start position:0% +Otherwise, we would just say, well, +let's just predict X Y to be a constant, + + align:start position:0% +let's just predict X Y to be a constant, + + + align:start position:0% +let's just predict X Y to be a constant, +meaning it does not depend on X. But if + + align:start position:0% +meaning it does not depend on X. But if + + + align:start position:0% +meaning it does not depend on X. But if +you wanted to depend on X, linear + + align:start position:0% +you wanted to depend on X, linear + + + align:start position:0% +you wanted to depend on X, linear +functions are basically as simple as it + + align:start position:0% +functions are basically as simple as it + + + align:start position:0% +functions are basically as simple as it +gets. Turns out, amazingly, this does + + align:start position:0% +gets. Turns out, amazingly, this does + + + align:start position:0% +gets. Turns out, amazingly, this does +the trick quite often. All right, so for + + align:start position:0% +the trick quite often. All right, so for + + + align:start position:0% +the trick quite often. All right, so for +example, if you look at economics, you + + align:start position:0% +example, if you look at economics, you + + + align:start position:0% +example, if you look at economics, you +might want to assume that the demand is + + align:start position:0% +might want to assume that the demand is + + + align:start position:0% +might want to assume that the demand is +a linear function of the price. All + + align:start position:0% +a linear function of the price. All + + + align:start position:0% +a linear function of the price. All +right, so if your price is zero, there's + + align:start position:0% +right, so if your price is zero, there's + + + align:start position:0% +right, so if your price is zero, there's +going to be a certain demand, and as the + + align:start position:0% +going to be a certain demand, and as the + + + align:start position:0% +going to be a certain demand, and as the +price increases, the demand is going to + + align:start position:0% +price increases, the demand is going to + + + align:start position:0% +price increases, the demand is going to +move. Do you think B is going to be + + align:start position:0% +move. Do you think B is going to be + + + align:start position:0% +move. Do you think B is going to be +positive or negative here? + + align:start position:0% + + + + align:start position:0% + +What? + + align:start position:0% +What? + + + align:start position:0% +What? +Typically, it's negative. Unless we're + + align:start position:0% +Typically, it's negative. Unless we're + + + align:start position:0% +Typically, it's negative. Unless we're +talking about maybe luxury goods. Uh + + align:start position:0% +talking about maybe luxury goods. Uh + + + align:start position:0% +talking about maybe luxury goods. Uh +where, you know, the more expensive the + + align:start position:0% +where, you know, the more expensive the + + + align:start position:0% +where, you know, the more expensive the +more people actually want it. Uh I mean, + + align:start position:0% +more people actually want it. Uh I mean, + + + align:start position:0% +more people actually want it. Uh I mean, +if we're talking about actual economic + + align:start position:0% +if we're talking about actual economic + + + align:start position:0% +if we're talking about actual economic +demand, it's probably uh definitely + + align:start position:0% +demand, it's probably uh definitely + + + align:start position:0% +demand, it's probably uh definitely +negative. All right. Uh it doesn't have + + align:start position:0% +negative. All right. Uh it doesn't have + + + align:start position:0% +negative. All right. Uh it doesn't have +to be, you know, clearly + + align:start position:0% +to be, you know, clearly + + + align:start position:0% +to be, you know, clearly +uh uh linear so that you can actually + + align:start position:0% +uh uh linear so that you can actually + + + align:start position:0% +uh uh linear so that you can actually +make it linear, transform it into some + + align:start position:0% +make it linear, transform it into some + + + align:start position:0% +make it linear, transform it into some +linear. So for for example you have this + + align:start position:0% +linear. So for for example you have this + + + align:start position:0% +linear. So for for example you have this +like multiplicative relationship right P + + align:start position:0% +like multiplicative relationship right P + + + align:start position:0% +like multiplicative relationship right P +uh you know PV equals NRT which is the + + align:start position:0% +uh you know PV equals NRT which is the + + + align:start position:0% +uh you know PV equals NRT which is the +IDS ga ideal gas law. uh if you want to + + align:start position:0% +IDS ga ideal gas law. uh if you want to + + + align:start position:0% +IDS ga ideal gas law. uh if you want to +actually write this relationship if you + + align:start position:0% +actually write this relationship if you + + + align:start position:0% +actually write this relationship if you +want to predict what the pressure is + + align:start position:0% +want to predict what the pressure is + + + align:start position:0% +want to predict what the pressure is +going to be as a function of the volume + + align:start position:0% +going to be as a function of the volume + + + align:start position:0% +going to be as a function of the volume +and the temperature + + align:start position:0% +and the temperature + + + align:start position:0% +and the temperature +uh and uh well let's assume that the uh + + align:start position:0% +uh and uh well let's assume that the uh + + + align:start position:0% +uh and uh well let's assume that the uh +so n is the avagadra constant and let's + + align:start position:0% +so n is the avagadra constant and let's + + + align:start position:0% +so n is the avagadra constant and let's +assume that the the radius is actually + + align:start position:0% +assume that the the radius is actually + + + align:start position:0% +assume that the the radius is actually +uh fixed then uh you have basically you + + align:start position:0% +uh fixed then uh you have basically you + + + align:start position:0% +uh fixed then uh you have basically you +take the log on each side right so you + + align:start position:0% +take the log on each side right so you + + + align:start position:0% +take the log on each side right so you +get pv equals nrt + + align:start position:0% + + + + align:start position:0% + +Okay. So, + + align:start position:0% + + + + align:start position:0% + +so what that means is that log PV is + + align:start position:0% +so what that means is that log PV is + + + align:start position:0% +so what that means is that log PV is +equal to log n RT. + + align:start position:0% +equal to log n RT. + + + align:start position:0% +equal to log n RT. +So that means that log P + + align:start position:0% +So that means that log P + + + align:start position:0% +So that means that log P +plus log V is equal to log + + align:start position:0% +plus log V is equal to log + + + align:start position:0% +plus log V is equal to log +N R + + align:start position:0% +N R + + + align:start position:0% +N R +plus log T. + + align:start position:0% +plus log T. + + + align:start position:0% +plus log T. +Okay. So this here we said that R is + + align:start position:0% +Okay. So this here we said that R is + + + align:start position:0% +Okay. So this here we said that R is +constant. So this is actually a + + align:start position:0% +constant. So this is actually a + + + align:start position:0% +constant. So this is actually a +constant. I'm going to call it A. + + align:start position:0% +constant. I'm going to call it A. + + + align:start position:0% +constant. I'm going to call it A. +And then that means that log P + + align:start position:0% +And then that means that log P + + + align:start position:0% +And then that means that log P +is equal to minus log B. + + align:start position:0% +is equal to minus log B. + + + align:start position:0% +is equal to minus log B. +Seriously uh + + align:start position:0% + + + + align:start position:0% + +that log p is equal to a + + align:start position:0% +that log p is equal to a + + + align:start position:0% +that log p is equal to a +uh minus log v + + align:start position:0% +uh minus log v + + + align:start position:0% +uh minus log v +plus log t. + + align:start position:0% +plus log t. + + + align:start position:0% +plus log t. +Okay. And so in particular if I write b + + align:start position:0% +Okay. And so in particular if I write b + + + align:start position:0% +Okay. And so in particular if I write b +uh equal to -1 and c equal to + one this + + align:start position:0% +uh equal to -1 and c equal to + one this + + + align:start position:0% +uh equal to -1 and c equal to + one this +gives me the formula that I have here. + + align:start position:0% +gives me the formula that I have here. + + + align:start position:0% +gives me the formula that I have here. +Now again it might be the case that you + + align:start position:0% +Now again it might be the case that you + + + align:start position:0% +Now again it might be the case that you +know this is the ideal gas law. So in + + align:start position:0% +know this is the ideal gas law. So in + + + align:start position:0% +know this is the ideal gas law. So in +practice if I start recording pressure + + align:start position:0% +practice if I start recording pressure + + + align:start position:0% +practice if I start recording pressure +and temperature and volume those things + + align:start position:0% +and temperature and volume those things + + + align:start position:0% +and temperature and volume those things +I might make measurement errors it might + + align:start position:0% +I might make measurement errors it might + + + align:start position:0% +I might make measurement errors it might +be slightly different conditions in such + + align:start position:0% +be slightly different conditions in such + + + align:start position:0% +be slightly different conditions in such +a way that I'm not going to get exactly + + align:start position:0% +a way that I'm not going to get exactly + + + align:start position:0% +a way that I'm not going to get exactly +those and I'm just going to put this + + align:start position:0% +those and I'm just going to put this + + + align:start position:0% +those and I'm just going to put this +little twiddle to account for the fact + + align:start position:0% +little twiddle to account for the fact + + + align:start position:0% +little twiddle to account for the fact +that the points that I'm going to be + + align:start position:0% +that the points that I'm going to be + + + align:start position:0% +that the points that I'm going to be +recording for log pressure log volume + + align:start position:0% +recording for log pressure log volume + + + align:start position:0% +recording for log pressure log volume +and log temperature are not going to be + + align:start position:0% +and log temperature are not going to be + + + align:start position:0% +and log temperature are not going to be +exactly on one line. Okay, they're going + + align:start position:0% +exactly on one line. Okay, they're going + + + align:start position:0% +exactly on one line. Okay, they're going +to be close. Actually, in those physics + + align:start position:0% +to be close. Actually, in those physics + + + align:start position:0% +to be close. Actually, in those physics +experiments, usually they're very close. + + align:start position:0% +experiments, usually they're very close. + + + align:start position:0% +experiments, usually they're very close. +It's actually because the conditions are + + align:start position:0% +It's actually because the conditions are + + + align:start position:0% +It's actually because the conditions are +controlled in under lab experiments. So, + + align:start position:0% +controlled in under lab experiments. So, + + + align:start position:0% +controlled in under lab experiments. So, +it means that the noise is very small. + + align:start position:0% +it means that the noise is very small. + + + align:start position:0% +it means that the noise is very small. +And uh but for other cases like demand + + align:start position:0% +And uh but for other cases like demand + + + align:start position:0% +And uh but for other cases like demand +and price, this is not a law of physics. + + align:start position:0% +and price, this is not a law of physics. + + + align:start position:0% +and price, this is not a law of physics. +And so, this might change. Uh even the + + align:start position:0% +And so, this might change. Uh even the + + + align:start position:0% +And so, this might change. Uh even the +linear structure is probably not clear, + + align:start position:0% +linear structure is probably not clear, + + + align:start position:0% +linear structure is probably not clear, +right? At some point, there's probably + + align:start position:0% +right? At some point, there's probably + + + align:start position:0% +right? At some point, there's probably +going to be some weird curvature + + align:start position:0% +going to be some weird curvature + + + align:start position:0% +going to be some weird curvature +happening. All right. So this slide is + + align:start position:0% +happening. All right. So this slide is + + + align:start position:0% +happening. All right. So this slide is +just to tell you maybe you don't have + + align:start position:0% +just to tell you maybe you don't have + + + align:start position:0% +just to tell you maybe you don't have +obviously a linear relationship but + + align:start position:0% +obviously a linear relationship but + + + align:start position:0% +obviously a linear relationship but +maybe you do if you start taking logs + + align:start position:0% +maybe you do if you start taking logs + + + align:start position:0% +maybe you do if you start taking logs +expect uh exponentials squares you can + + align:start position:0% +expect uh exponentials squares you can + + + align:start position:0% +expect uh exponentials squares you can +sometimes take the product of two + + align:start position:0% +sometimes take the product of two + + + align:start position:0% +sometimes take the product of two +variables things like this right so this + + align:start position:0% +variables things like this right so this + + + align:start position:0% +variables things like this right so this +is variable transformation and it's + + align:start position:0% +is variable transformation and it's + + + align:start position:0% +is variable transformation and it's +mostly domain specific so we're not + + align:start position:0% +mostly domain specific so we're not + + + align:start position:0% +mostly domain specific so we're not +going to go into much details of this + + align:start position:0% +going to go into much details of this + + + align:start position:0% +going to go into much details of this +any questions. + + align:start position:0% + + + + align:start position:0% + +All right. So, um, now I'm going to be + + align:start position:0% +All right. So, um, now I'm going to be + + + align:start position:0% +All right. So, um, now I'm going to be +given, uh, um, so if we start thinking a + + align:start position:0% +given, uh, um, so if we start thinking a + + + align:start position:0% +given, uh, um, so if we start thinking a +little more about what those + + align:start position:0% +little more about what those + + + align:start position:0% +little more about what those +coefficients should be. Well, remember, + + align:start position:0% +coefficients should be. Well, remember, + + + align:start position:0% +coefficients should be. Well, remember, +so just everybody's clear why I don't + + align:start position:0% +so just everybody's clear why I don't + + + align:start position:0% +so just everybody's clear why I don't +put the little i here, + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +right? I don't put the little i because + + align:start position:0% +right? I don't put the little i because + + + align:start position:0% +right? I don't put the little i because +I'm just talking about a generic x and a + + align:start position:0% +I'm just talking about a generic x and a + + + align:start position:0% +I'm just talking about a generic x and a +generic y, but the observations are x1, + + align:start position:0% +generic y, but the observations are x1, + + + align:start position:0% +generic y, but the observations are x1, +y1, right? So typically on the + + align:start position:0% +y1, right? So typically on the + + + align:start position:0% +y1, right? So typically on the +blackboard I'm often going to write only + + align:start position:0% +blackboard I'm often going to write only + + + align:start position:0% +blackboard I'm often going to write only +XY + + align:start position:0% +XY + + + align:start position:0% +XY +but the data really is + + align:start position:0% + + + + align:start position:0% + +X1 Y1 + + align:start position:0% +X1 Y1 + + + align:start position:0% +X1 Y1 +all the way to XN YN. Right? So those + + align:start position:0% +all the way to XN YN. Right? So those + + + align:start position:0% +all the way to XN YN. Right? So those +are this points in this two-dimensional + + align:start position:0% +are this points in this two-dimensional + + + align:start position:0% +are this points in this two-dimensional +plot. And uh but I think of those as + + align:start position:0% +plot. And uh but I think of those as + + + align:start position:0% +plot. And uh but I think of those as +being copies independent copies of + + align:start position:0% + + + + align:start position:0% + +of the pair XY. Okay, + + align:start position:0% +of the pair XY. Okay, + + + align:start position:0% +of the pair XY. Okay, +they have to have the the to contain the + + align:start position:0% +they have to have the the to contain the + + + align:start position:0% +they have to have the the to contain the +relationship. And so when I talk about + + align:start position:0% +relationship. And so when I talk about + + + align:start position:0% +relationship. And so when I talk about +distribution of those random variables, + + align:start position:0% +distribution of those random variables, + + + align:start position:0% +distribution of those random variables, +I can only I talk about the distribution + + align:start position:0% +I can only I talk about the distribution + + + align:start position:0% +I can only I talk about the distribution +of XY and that's the same. Right? So the + + align:start position:0% +of XY and that's the same. Right? So the + + + align:start position:0% +of XY and that's the same. Right? So the +first thing you might want to ask is, + + align:start position:0% +first thing you might want to ask is, + + + align:start position:0% +first thing you might want to ask is, +well, if I have an infinite amount of + + align:start position:0% +well, if I have an infinite amount of + + + align:start position:0% +well, if I have an infinite amount of +data, + + align:start position:0% +data, + + + align:start position:0% +data, +what do I what what can I hope to get + + align:start position:0% +what do I what what can I hope to get + + + align:start position:0% +what do I what what can I hope to get +for A and B, right? If my sample size + + align:start position:0% +for A and B, right? If my sample size + + + align:start position:0% +for A and B, right? If my sample size +goes to infinity, then I should actually + + align:start position:0% +goes to infinity, then I should actually + + + align:start position:0% +goes to infinity, then I should actually +know exactly what the distribution of XY + + align:start position:0% +know exactly what the distribution of XY + + + align:start position:0% +know exactly what the distribution of XY +is. And so there should be an A and a B + + align:start position:0% +is. And so there should be an A and a B + + + align:start position:0% +is. And so there should be an A and a B +that captures this linear relationship + + align:start position:0% +that captures this linear relationship + + + align:start position:0% +that captures this linear relationship +between Y and X. Okay? And so in + + align:start position:0% +between Y and X. Okay? And so in + + + align:start position:0% +between Y and X. Okay? And so in +particular, we're going to try to ask + + align:start position:0% +particular, we're going to try to ask + + + align:start position:0% +particular, we're going to try to ask +the population or theoretic values of A + + align:start position:0% +the population or theoretic values of A + + + align:start position:0% +the population or theoretic values of A +and B. And you can see that you can + + align:start position:0% +and B. And you can see that you can + + + align:start position:0% +and B. And you can see that you can +actually compute them explicitly. So + + align:start position:0% +actually compute them explicitly. So + + + align:start position:0% +actually compute them explicitly. So +let's just try to find how. So as I + + align:start position:0% +let's just try to find how. So as I + + + align:start position:0% +let's just try to find how. So as I +said, we have a bunch of points on this + + align:start position:0% +said, we have a bunch of points on this + + + align:start position:0% +said, we have a bunch of points on this +line + + align:start position:0% +line + + + align:start position:0% +line +close to a line. + + align:start position:0% +close to a line. + + + align:start position:0% +close to a line. +And I'm trying to find the best fit. + + align:start position:0% +And I'm trying to find the best fit. + + + align:start position:0% +And I'm trying to find the best fit. +All right? So this guy is not a good + + align:start position:0% +All right? So this guy is not a good + + + align:start position:0% +All right? So this guy is not a good +fit. This guy is not a good fit. And we + + align:start position:0% +fit. This guy is not a good fit. And we + + + align:start position:0% +fit. This guy is not a good fit. And we +know that this guy is a good fit + + align:start position:0% +know that this guy is a good fit + + + align:start position:0% +know that this guy is a good fit +somehow. So we need to mathematically + + align:start position:0% +somehow. So we need to mathematically + + + align:start position:0% +somehow. So we need to mathematically +formulate the fact that this line here + + align:start position:0% +formulate the fact that this line here + + + align:start position:0% +formulate the fact that this line here +is better than this line here or better + + align:start position:0% +is better than this line here or better + + + align:start position:0% +is better than this line here or better +than this line here. So what we're + + align:start position:0% +than this line here. So what we're + + + align:start position:0% +than this line here. So what we're +trying to do is to create a function + + align:start position:0% +trying to do is to create a function + + + align:start position:0% +trying to do is to create a function +that has values that are smaller for + + align:start position:0% +that has values that are smaller for + + + align:start position:0% +that has values that are smaller for +this curve and larger for these two + + align:start position:0% +this curve and larger for these two + + + align:start position:0% +this curve and larger for these two +curves. And the way we do it is by + + align:start position:0% +curves. And the way we do it is by + + + align:start position:0% +curves. And the way we do it is by +measuring the fit. And the fit is + + align:start position:0% +measuring the fit. And the fit is + + + align:start position:0% +measuring the fit. And the fit is +essentially the aggregate distance of + + align:start position:0% +essentially the aggregate distance of + + + align:start position:0% +essentially the aggregate distance of +all the points to the curve. All right? + + align:start position:0% +all the points to the curve. All right? + + + align:start position:0% +all the points to the curve. All right? +And there's many ways I can measure the + + align:start position:0% +And there's many ways I can measure the + + + align:start position:0% +And there's many ways I can measure the +distance to a curve, right? So if I want + + align:start position:0% +distance to a curve, right? So if I want + + + align:start position:0% +distance to a curve, right? So if I want +to find, so let's just open a + + align:start position:0% +to find, so let's just open a + + + align:start position:0% +to find, so let's just open a +parenthesis. If I have a point here, so + + align:start position:0% +parenthesis. If I have a point here, so + + + align:start position:0% +parenthesis. If I have a point here, so +we're going to do it for one point at a + + align:start position:0% +we're going to do it for one point at a + + + align:start position:0% +we're going to do it for one point at a +time. So if I have a point, there's many + + align:start position:0% +time. So if I have a point, there's many + + + align:start position:0% +time. So if I have a point, there's many +ways I can measure it distance to the + + align:start position:0% +ways I can measure it distance to the + + + align:start position:0% +ways I can measure it distance to the +curve, right? I can measure it like + + align:start position:0% +curve, right? I can measure it like + + + align:start position:0% +curve, right? I can measure it like +that. + + align:start position:0% +that. + + + align:start position:0% +that. +That is one distance to the curve. I can + + align:start position:0% +That is one distance to the curve. I can + + + align:start position:0% +That is one distance to the curve. I can +measure it like that by having a right + + align:start position:0% +measure it like that by having a right + + + align:start position:0% +measure it like that by having a right +angle here. That is one distance to the + + align:start position:0% +angle here. That is one distance to the + + + align:start position:0% +angle here. That is one distance to the +curve. Or I can measure it like that. + + align:start position:0% +curve. Or I can measure it like that. + + + align:start position:0% +curve. Or I can measure it like that. +that is another distance to the curve, + + align:start position:0% +that is another distance to the curve, + + + align:start position:0% +that is another distance to the curve, +right? + + align:start position:0% +right? + + + align:start position:0% +right? +There's many ways I can go for it. It + + align:start position:0% +There's many ways I can go for it. It + + + align:start position:0% +There's many ways I can go for it. It +turns out that one is actually going to + + align:start position:0% +turns out that one is actually going to + + + align:start position:0% +turns out that one is actually going to +be fairly convenient for us and that's + + align:start position:0% +be fairly convenient for us and that's + + + align:start position:0% +be fairly convenient for us and that's +the one that says let's look at the + + align:start position:0% +the one that says let's look at the + + + align:start position:0% +the one that says let's look at the +square of the value of x on the curve. + + align:start position:0% +square of the value of x on the curve. + + + align:start position:0% +square of the value of x on the curve. +Right? So if this is the curve + + align:start position:0% +Right? So if this is the curve + + + align:start position:0% +Right? So if this is the curve +y is equal to a + bx. + + align:start position:0% + + + + align:start position:0% + +Now I'm going to think of this point as + + align:start position:0% +Now I'm going to think of this point as + + + align:start position:0% +Now I'm going to think of this point as +a random point capital X capital Y. + + align:start position:0% +a random point capital X capital Y. + + + align:start position:0% +a random point capital X capital Y. +Okay. And so that means that it's going + + align:start position:0% +Okay. And so that means that it's going + + + align:start position:0% +Okay. And so that means that it's going +to be instant. It's going to be X1 X Y1 + + align:start position:0% +to be instant. It's going to be X1 X Y1 + + + align:start position:0% +to be instant. It's going to be X1 X Y1 +or X2 Y2 etc. Now I want to measure the + + align:start position:0% +or X2 Y2 etc. Now I want to measure the + + + align:start position:0% +or X2 Y2 etc. Now I want to measure the +distance. Can somebody tell me which of + + align:start position:0% +distance. Can somebody tell me which of + + + align:start position:0% +distance. Can somebody tell me which of +the three the first one the second one + + align:start position:0% +the three the first one the second one + + + align:start position:0% +the three the first one the second one +or the third one this formula + + align:start position:0% +or the third one this formula + + + align:start position:0% +or the third one this formula +expectation of y - a minus bx^2 is is is + + align:start position:0% +expectation of y - a minus bx^2 is is is + + + align:start position:0% +expectation of y - a minus bx^2 is is is +which of the three is it representing? + + align:start position:0% + + + + align:start position:0% + +The second one where I have the right + + align:start position:0% +The second one where I have the right + + + align:start position:0% +The second one where I have the right +angle. + + align:start position:0% +angle. + + + align:start position:0% +angle. +Okay. Everybody agrees with this. + + align:start position:0% +Okay. Everybody agrees with this. + + + align:start position:0% +Okay. Everybody agrees with this. +Anybody wants to vote for something + + align:start position:0% +Anybody wants to vote for something + + + align:start position:0% +Anybody wants to vote for something +else? Yeah. The third one. Who? + + align:start position:0% +else? Yeah. The third one. Who? + + + align:start position:0% +else? Yeah. The third one. Who? +Everybody agrees with the third one. So, + + align:start position:0% +Everybody agrees with the third one. So, + + + align:start position:0% +Everybody agrees with the third one. So, +by default, everybody's on the first + + align:start position:0% +by default, everybody's on the first + + + align:start position:0% +by default, everybody's on the first +one. Yeah. + + align:start position:0% +one. Yeah. + + + align:start position:0% +one. Yeah. +Yeah. It is the vertical distance + + align:start position:0% +Yeah. It is the vertical distance + + + align:start position:0% +Yeah. It is the vertical distance +actually. Right. So, and the reason is + + align:start position:0% +actually. Right. So, and the reason is + + + align:start position:0% +actually. Right. So, and the reason is +if it was the one with the straight + + align:start position:0% +if it was the one with the straight + + + align:start position:0% +if it was the one with the straight +angle with the right angle, it would + + align:start position:0% +angle with the right angle, it would + + + align:start position:0% +angle with the right angle, it would +actually be very complicated + + align:start position:0% +actually be very complicated + + + align:start position:0% +actually be very complicated +mathematical formula. So let's just see + + align:start position:0% +mathematical formula. So let's just see + + + align:start position:0% +mathematical formula. So let's just see +why, right? So and by y I mean y okay so + + align:start position:0% +why, right? So and by y I mean y okay so + + + align:start position:0% +why, right? So and by y I mean y okay so +uh this is this means that this is my x + + align:start position:0% +uh this is this means that this is my x + + + align:start position:0% +uh this is this means that this is my x +okay and this is my y + + align:start position:0% + + + + align:start position:0% + +right so that means that this point is + + align:start position:0% +right so that means that this point is + + + align:start position:0% +right so that means that this point is +xy + + align:start position:0% +xy + + + align:start position:0% +xy +so what I'm measuring is the difference + + align:start position:0% +so what I'm measuring is the difference + + + align:start position:0% +so what I'm measuring is the difference +between y + + align:start position:0% +between y + + + align:start position:0% +between y +minus a + b * x right + + align:start position:0% +minus a + b * x right + + + align:start position:0% +minus a + b * x right +this is the thing I'm going to take the + + align:start position:0% +this is the thing I'm going to take the + + + align:start position:0% +this is the thing I'm going to take the +expectation of the square and then the + + align:start position:0% +expectation of the square and then the + + + align:start position:0% +expectation of the square and then the +expect So a + b * x if this is this line + + align:start position:0% +expect So a + b * x if this is this line + + + align:start position:0% +expect So a + b * x if this is this line +this is this point. So that's this value + + align:start position:0% +this is this point. So that's this value + + + align:start position:0% +this is this point. So that's this value +here. + + align:start position:0% +here. + + + align:start position:0% +here. +This value here is a + + align:start position:0% +This value here is a + + + align:start position:0% +This value here is a +plus bx. Right? + + align:start position:0% +plus bx. Right? + + + align:start position:0% +plus bx. Right? +So what I'm really measuring is the + + align:start position:0% +So what I'm really measuring is the + + + align:start position:0% +So what I'm really measuring is the +difference between y and m plus bx which + + align:start position:0% +difference between y and m plus bx which + + + align:start position:0% +difference between y and m plus bx which +is this distance here. + + align:start position:0% + + + + align:start position:0% + +And since I like things like Pythagoras + + align:start position:0% +And since I like things like Pythagoras + + + align:start position:0% +And since I like things like Pythagoras +theorem, uh I'm actually going to put a + + align:start position:0% +theorem, uh I'm actually going to put a + + + align:start position:0% +theorem, uh I'm actually going to put a +square here before I take the + + align:start position:0% +square here before I take the + + + align:start position:0% +square here before I take the +expectation. + + align:start position:0% +expectation. + + + align:start position:0% +expectation. +Okay, so now this is a random variable. + + align:start position:0% +Okay, so now this is a random variable. + + + align:start position:0% +Okay, so now this is a random variable. +This is this random variable. And so I + + align:start position:0% +This is this random variable. And so I + + + align:start position:0% +This is this random variable. And so I +want a number. So I'm going to turn it + + align:start position:0% +want a number. So I'm going to turn it + + + align:start position:0% +want a number. So I'm going to turn it +into a deterministic number. And the way + + align:start position:0% +into a deterministic number. And the way + + + align:start position:0% +into a deterministic number. And the way +I do this is by taking expectation. + + align:start position:0% +I do this is by taking expectation. + + + align:start position:0% +I do this is by taking expectation. +Okay? And doing expectation. If you + + align:start position:0% +Okay? And doing expectation. If you + + + align:start position:0% +Okay? And doing expectation. If you +think expectation should be close to + + align:start position:0% +think expectation should be close to + + + align:start position:0% +think expectation should be close to +average, this is the same thing as + + align:start position:0% +average, this is the same thing as + + + align:start position:0% +average, this is the same thing as +saying I want that in average the y's + + align:start position:0% +saying I want that in average the y's + + + align:start position:0% +saying I want that in average the y's +are close to the a plus bx, right? So + + align:start position:0% +are close to the a plus bx, right? So + + + align:start position:0% +are close to the a plus bx, right? So +we're doing it in expectation, but + + align:start position:0% +we're doing it in expectation, but + + + align:start position:0% +we're doing it in expectation, but +that's going to translate into doing it + + align:start position:0% +that's going to translate into doing it + + + align:start position:0% +that's going to translate into doing it +in average for all the points. All + + align:start position:0% +in average for all the points. All + + + align:start position:0% +in average for all the points. All +right. So this is the thing I want to + + align:start position:0% +right. So this is the thing I want to + + + align:start position:0% +right. So this is the thing I want to +measure. So that's this vertical + + align:start position:0% +measure. So that's this vertical + + + align:start position:0% +measure. So that's this vertical +distance. Yeah. + + align:start position:0% +distance. Yeah. + + + align:start position:0% +distance. Yeah. +Oh, again. Okay. Sorry. I'm just uh + + align:start position:0% + + + + align:start position:0% + +this is my fault actually. Um + + align:start position:0% +this is my fault actually. Um + + + align:start position:0% +this is my fault actually. Um +maybe we should close those shades. + + align:start position:0% + + + + align:start position:0% + +Okay. I cannot I cannot do just uh one + + align:start position:0% +Okay. I cannot I cannot do just uh one + + + align:start position:0% +Okay. I cannot I cannot do just uh one +at a time. Sorry. + + align:start position:0% + + + + align:start position:0% + +Okay. So + + align:start position:0% +Okay. So + + + align:start position:0% +Okay. So +the uh um + + align:start position:0% + + + + align:start position:0% + +All right. So now that I do those uh + + align:start position:0% +All right. So now that I do those uh + + + align:start position:0% +All right. So now that I do those uh +vertical distances, I can I can ask well + + align:start position:0% +vertical distances, I can I can ask well + + + align:start position:0% +vertical distances, I can I can ask well +now I have this function, right? to have + + align:start position:0% +now I have this function, right? to have + + + align:start position:0% +now I have this function, right? to have +a function that takes two parameters a + + align:start position:0% +a function that takes two parameters a + + + align:start position:0% +a function that takes two parameters a +and b maps it to the expectation of y - + + align:start position:0% +and b maps it to the expectation of y - + + + align:start position:0% +and b maps it to the expectation of y - +a + b x^2 + + align:start position:0% +a + b x^2 + + + align:start position:0% +a + b x^2 +sorry the square is here and I can ask + + align:start position:0% +sorry the square is here and I can ask + + + align:start position:0% +sorry the square is here and I can ask +well this is a function that measures + + align:start position:0% +well this is a function that measures + + + align:start position:0% +well this is a function that measures +the fit of the parameters a and b right + + align:start position:0% +the fit of the parameters a and b right + + + align:start position:0% +the fit of the parameters a and b right +this function should be small the value + + align:start position:0% +this function should be small the value + + + align:start position:0% +this function should be small the value +of this function here + + align:start position:0% +of this function here + + + align:start position:0% +of this function here +function + + align:start position:0% +function + + + align:start position:0% +function +of a and E + + align:start position:0% +of a and E + + + align:start position:0% +of a and E +that measures + + align:start position:0% + + + + align:start position:0% + +how close + + align:start position:0% + + + + align:start position:0% + +the + + align:start position:0% +the + + + align:start position:0% +the +um point + + align:start position:0% +um point + + + align:start position:0% +um point +xy + + align:start position:0% +xy + + + align:start position:0% +xy +is to the line + + align:start position:0% + + + + align:start position:0% + +a + b * x. Well, y is equal a + b * x. + + align:start position:0% +a + b * x. Well, y is equal a + b * x. + + + align:start position:0% +a + b * x. Well, y is equal a + b * x. +uh in expectation. + + align:start position:0% + + + + align:start position:0% + +Okay, agreed? This is what we we just + + align:start position:0% +Okay, agreed? This is what we we just + + + align:start position:0% +Okay, agreed? This is what we we just +said. And you can think if again if + + align:start position:0% +said. And you can think if again if + + + align:start position:0% +said. And you can think if again if +you're not comfortable with the reason + + align:start position:0% +you're not comfortable with the reason + + + align:start position:0% +you're not comfortable with the reason +why to expectations, just think about + + align:start position:0% +why to expectations, just think about + + + align:start position:0% +why to expectations, just think about +having data points and taking the + + align:start position:0% +having data points and taking the + + + align:start position:0% +having data points and taking the +average value for this guy. So it's + + align:start position:0% +average value for this guy. So it's + + + align:start position:0% +average value for this guy. So it's +basically an aggregate distance of the + + align:start position:0% +basically an aggregate distance of the + + + align:start position:0% +basically an aggregate distance of the +points uh to their uh to the uh the the + + align:start position:0% +points uh to their uh to the uh the the + + + align:start position:0% +points uh to their uh to the uh the the +line. Okay, everybody agrees this is a + + align:start position:0% +line. Okay, everybody agrees this is a + + + align:start position:0% +line. Okay, everybody agrees this is a +legitimate measure. If all my points + + align:start position:0% +legitimate measure. If all my points + + + align:start position:0% +legitimate measure. If all my points +were on the line, if my distribution, if + + align:start position:0% +were on the line, if my distribution, if + + + align:start position:0% +were on the line, if my distribution, if +y was actually equal to a plus bx for + + align:start position:0% +y was actually equal to a plus bx for + + + align:start position:0% +y was actually equal to a plus bx for +some a and b, then this function would + + align:start position:0% +some a and b, then this function would + + + align:start position:0% +some a and b, then this function would +be equal to zero for the correct a and + + align:start position:0% +be equal to zero for the correct a and + + + align:start position:0% +be equal to zero for the correct a and +b, right? + + align:start position:0% +b, right? + + + align:start position:0% +b, right? +If they're far, well, it's going to + + align:start position:0% +If they're far, well, it's going to + + + align:start position:0% +If they're far, well, it's going to +depend on how much noise I'm getting. + + align:start position:0% +depend on how much noise I'm getting. + + + align:start position:0% +depend on how much noise I'm getting. +But it's still going to be minimized for + + align:start position:0% +But it's still going to be minimized for + + + align:start position:0% +But it's still going to be minimized for +the best one. So, let's minimize this + + align:start position:0% +the best one. So, let's minimize this + + + align:start position:0% +the best one. So, let's minimize this +thing. + + align:start position:0% +thing. + + + align:start position:0% +thing. +So + + align:start position:0% +So + + + align:start position:0% +So +here I don't make any uh again sorry uh + + align:start position:0% +here I don't make any uh again sorry uh + + + align:start position:0% +here I don't make any uh again sorry uh +I don't make any assumption on um on uh + + align:start position:0% +I don't make any assumption on um on uh + + + align:start position:0% +I don't make any assumption on um on uh +uh the distribution of x or y here I + + align:start position:0% +uh the distribution of x or y here I + + + align:start position:0% +uh the distribution of x or y here I +assume somehow that the variance of x + + align:start position:0% + + + + align:start position:0% + +is not equal to zero. Can somebody tell + + align:start position:0% +is not equal to zero. Can somebody tell + + + align:start position:0% +is not equal to zero. Can somebody tell +me why? Yeah. + + align:start position:0% + + + + align:start position:0% + +No, here I've actually written the + + align:start position:0% +No, here I've actually written the + + + align:start position:0% +No, here I've actually written the +expectation of the square. + + align:start position:0% +expectation of the square. + + + align:start position:0% +expectation of the square. +If I wanted to write the square of the + + align:start position:0% +If I wanted to write the square of the + + + align:start position:0% +If I wanted to write the square of the +expectation, I would just do this. + + align:start position:0% +expectation, I would just do this. + + + align:start position:0% +expectation, I would just do this. +So, so let's just make it clear, + + align:start position:0% + + + + align:start position:0% + +right? Do you want me to put an extra + + align:start position:0% +right? Do you want me to put an extra + + + align:start position:0% +right? Do you want me to put an extra +set of parenthesis? That's what you want + + align:start position:0% +set of parenthesis? That's what you want + + + align:start position:0% +set of parenthesis? That's what you want +me to do. + + align:start position:0% +me to do. + + + align:start position:0% +me to do. +Yeah. + + align:start position:0% + + + + align:start position:0% + +Okay. That's the one that makes sense. + + align:start position:0% +Okay. That's the one that makes sense. + + + align:start position:0% +Okay. That's the one that makes sense. +So, the square of the expectation. + + align:start position:0% +So, the square of the expectation. + + + align:start position:0% +So, the square of the expectation. +Yeah. + + align:start position:0% +Yeah. + + + align:start position:0% +Yeah. +The expectation of the square. Sorry. + + align:start position:0% + + + + align:start position:0% + +Yeah. Dyslexia. All right. Uh, any + + align:start position:0% +Yeah. Dyslexia. All right. Uh, any + + + align:start position:0% +Yeah. Dyslexia. All right. Uh, any +question? + + align:start position:0% +question? + + + align:start position:0% +question? +Yeah. + + align:start position:0% +Yeah. + + + align:start position:0% +Yeah. +Does this assume that the error is + + align:start position:0% +Does this assume that the error is + + + align:start position:0% +Does this assume that the error is +Gaussian? + + align:start position:0% +Gaussian? + + + align:start position:0% +Gaussian? +No. + + align:start position:0% + + + + align:start position:0% + +I mean in the sense that like if we knew + + align:start position:0% +I mean in the sense that like if we knew + + + align:start position:0% +I mean in the sense that like if we knew +that the error was like + + align:start position:0% +that the error was like + + + align:start position:0% +that the error was like +follow + + align:start position:0% + + + + align:start position:0% + +we want to minimize the + + align:start position:0% +we want to minimize the + + + align:start position:0% +we want to minimize the +y + + align:start position:0% + + + + align:start position:0% + +why + + align:start position:0% + + + + align:start position:0% + +so you know the answer to your question + + align:start position:0% +so you know the answer to your question + + + align:start position:0% +so you know the answer to your question +so I just want you to use the words that + + align:start position:0% +so I just want you to use the words that + + + align:start position:0% +so I just want you to use the words that +uh right so why would you want to use + + align:start position:0% +uh right so why would you want to use + + + align:start position:0% +uh right so why would you want to use +the fourth power + + align:start position:0% +the fourth power + + + align:start position:0% +the fourth power +because like we want more + + align:start position:0% +because like we want more + + + align:start position:0% +because like we want more +expectations + + align:start position:0% +expectations + + + align:start position:0% +expectations +to be very rare + + align:start position:0% +to be very rare + + + align:start position:0% +to be very rare +or more rare than + + align:start position:0% +or more rare than + + + align:start position:0% +or more rare than +yeah so + + align:start position:0% +yeah so + + + align:start position:0% +yeah so +that would be the maximum likelihood + + align:start position:0% +that would be the maximum likelihood + + + align:start position:0% +that would be the maximum likelihood +estimator that you're describing to me + + align:start position:0% +estimator that you're describing to me + + + align:start position:0% +estimator that you're describing to me +right I can actually write the + + align:start position:0% +right I can actually write the + + + align:start position:0% +right I can actually write the +likelihood of a pair of numbers AB and + + align:start position:0% +likelihood of a pair of numbers AB and + + + align:start position:0% +likelihood of a pair of numbers AB and +if I know this that's actually what's + + align:start position:0% +if I know this that's actually what's + + + align:start position:0% +if I know this that's actually what's +going to come into it because I know + + align:start position:0% +going to come into it because I know + + + align:start position:0% +going to come into it because I know +that the density + + align:start position:0% +that the density + + + align:start position:0% +that the density +is going to come in into play when I + + align:start position:0% +is going to come in into play when I + + + align:start position:0% +is going to come in into play when I +talk about the but here I'm just talking + + align:start position:0% +talk about the but here I'm just talking + + + align:start position:0% +talk about the but here I'm just talking +about a this is a mechanical tool I'm + + align:start position:0% +about a this is a mechanical tool I'm + + + align:start position:0% +about a this is a mechanical tool I'm +just saying let's minimize the distance + + align:start position:0% +just saying let's minimize the distance + + + align:start position:0% +just saying let's minimize the distance +to the curve another thing I could have + + align:start position:0% +to the curve another thing I could have + + + align:start position:0% +to the curve another thing I could have +done is take the absolute value of this + + align:start position:0% +done is take the absolute value of this + + + align:start position:0% +done is take the absolute value of this +thing for example I just decided to take + + align:start position:0% +thing for example I just decided to take + + + align:start position:0% +thing for example I just decided to take +the square before I did it okay so + + align:start position:0% +the square before I did it okay so + + + align:start position:0% +the square before I did it okay so +regardless of what I'm doing I'm just + + align:start position:0% +regardless of what I'm doing I'm just + + + align:start position:0% +regardless of what I'm doing I'm just +taking the squares because that's just + + align:start position:0% +taking the squares because that's just + + + align:start position:0% +taking the squares because that's just +going to be convenient for me to do my + + align:start position:0% +going to be convenient for me to do my + + + align:start position:0% +going to be convenient for me to do my +computations for now but we don't have + + align:start position:0% +computations for now but we don't have + + + align:start position:0% +computations for now but we don't have +any statistical model at this point + + align:start position:0% +any statistical model at this point + + + align:start position:0% +any statistical model at this point +right I didn't say anything that y + + align:start position:0% +right I didn't say anything that y + + + align:start position:0% +right I didn't say anything that y +follows this x follows this. I'm just + + align:start position:0% +follows this x follows this. I'm just + + + align:start position:0% +follows this x follows this. I'm just +doing minimal assumptions as we go. All + + align:start position:0% +doing minimal assumptions as we go. All + + + align:start position:0% +doing minimal assumptions as we go. All +right. + + align:start position:0% +right. + + + align:start position:0% +right. +So, the variance of x is not equal to + + align:start position:0% +So, the variance of x is not equal to + + + align:start position:0% +So, the variance of x is not equal to +zero. Can somebody tell me why? + + align:start position:0% + + + + align:start position:0% + +What would happen in my what would my + + align:start position:0% +What would happen in my what would my + + + align:start position:0% +What would happen in my what would my +point cloud point look like if the + + align:start position:0% +point cloud point look like if the + + + align:start position:0% +point cloud point look like if the +variance of x was equal to zero? Yeah, + + align:start position:0% +variance of x was equal to zero? Yeah, + + + align:start position:0% +variance of x was equal to zero? Yeah, +they would all be at the same point. So, + + align:start position:0% +they would all be at the same point. So, + + + align:start position:0% +they would all be at the same point. So, +it's going to be hard for me to start + + align:start position:0% +it's going to be hard for me to start + + + align:start position:0% +it's going to be hard for me to start +fitting a line, right? I mean, best case + + align:start position:0% +fitting a line, right? I mean, best case + + + align:start position:0% +fitting a line, right? I mean, best case +scenario, I have this x, it has variance + + align:start position:0% +scenario, I have this x, it has variance + + + align:start position:0% +scenario, I have this x, it has variance +zero. So, this is the expectation of x + + align:start position:0% +zero. So, this is the expectation of x + + + align:start position:0% +zero. So, this is the expectation of x +and all my points + + align:start position:0% +and all my points + + + align:start position:0% +and all my points +have the same expectation + + align:start position:0% +have the same expectation + + + align:start position:0% +have the same expectation +then so yes I could probably fit that + + align:start position:0% +then so yes I could probably fit that + + + align:start position:0% +then so yes I could probably fit that +line but uh that wouldn't help very much + + align:start position:0% +line but uh that wouldn't help very much + + + align:start position:0% +line but uh that wouldn't help very much +for other x's right so I need a bit of + + align:start position:0% +for other x's right so I need a bit of + + + align:start position:0% +for other x's right so I need a bit of +variance so that things spread out a + + align:start position:0% +variance so that things spread out a + + + align:start position:0% +variance so that things spread out a +little bit and um and uh + + align:start position:0% +little bit and um and uh + + + align:start position:0% +little bit and um and uh +okay I'm going to have to do this + + align:start position:0% +okay I'm going to have to do this + + + align:start position:0% +okay I'm going to have to do this +I think it's just my um + + align:start position:0% + + + + align:start position:0% + +Okay, let's hope I'm gonna + + align:start position:0% + + + + align:start position:0% + +All right, so I'm going to put a little + + align:start position:0% +All right, so I'm going to put a little + + + align:start position:0% +All right, so I'm going to put a little +bit of less variance and the other thing + + align:start position:0% +bit of less variance and the other thing + + + align:start position:0% +bit of less variance and the other thing +is here I don't want to do much more but + + align:start position:0% +is here I don't want to do much more but + + + align:start position:0% +is here I don't want to do much more but +I'm actually going to think of X as + + align:start position:0% +I'm actually going to think of X as + + + align:start position:0% +I'm actually going to think of X as +having + + align:start position:0% +having + + + align:start position:0% +having +uh mean zero and the way I do this is as + + align:start position:0% +uh mean zero and the way I do this is as + + + align:start position:0% +uh mean zero and the way I do this is as +follows. Let's define X tilda which is X + + align:start position:0% +follows. Let's define X tilda which is X + + + align:start position:0% +follows. Let's define X tilda which is X +minus the expectation of X. + + align:start position:0% +minus the expectation of X. + + + align:start position:0% +minus the expectation of X. +Okay. So definitely the expectation of X + + align:start position:0% +Okay. So definitely the expectation of X + + + align:start position:0% +Okay. So definitely the expectation of X +tilda is what? + + align:start position:0% +tilda is what? + + + align:start position:0% +tilda is what? +Zero. Okay. And so now I want to + + align:start position:0% +Zero. Okay. And so now I want to + + + align:start position:0% +Zero. Okay. And so now I want to +minimize + + align:start position:0% +minimize + + + align:start position:0% +minimize +in AB + + align:start position:0% +in AB + + + align:start position:0% +in AB +expectation of Y + + align:start position:0% +expectation of Y + + + align:start position:0% +expectation of Y +minus A + B X + + align:start position:0% + + + + align:start position:0% + +squared. + + align:start position:0% +squared. + + + align:start position:0% +squared. +And what I'm going to the way I'm going + + align:start position:0% +And what I'm going to the way I'm going + + + align:start position:0% +And what I'm going to the way I'm going +to do this + + align:start position:0% + + + + align:start position:0% + +is by turning X into X tilda and + + align:start position:0% +is by turning X into X tilda and + + + align:start position:0% +is by turning X into X tilda and +stuffing the extra + + align:start position:0% +stuffing the extra + + + align:start position:0% +stuffing the extra +um and and putting the extra uh um uh + + align:start position:0% +um and and putting the extra uh um uh + + + align:start position:0% +um and and putting the extra uh um uh +expectation of X into the A. Okay. So + + align:start position:0% +expectation of X into the A. Okay. So + + + align:start position:0% +expectation of X into the A. Okay. So +I'm going to write this as expectation + + align:start position:0% +I'm going to write this as expectation + + + align:start position:0% +I'm going to write this as expectation +of y minus + + align:start position:0% +of y minus + + + align:start position:0% +of y minus +a plus b + + align:start position:0% +a plus b + + + align:start position:0% +a plus b +uh expectation of x + + align:start position:0% +uh expectation of x + + + align:start position:0% +uh expectation of x +which I'm going to call a tilda + + align:start position:0% +which I'm going to call a tilda + + + align:start position:0% +which I'm going to call a tilda +and plus b xtilda. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +And uh everybody agrees with this. So + + align:start position:0% +And uh everybody agrees with this. So + + + align:start position:0% +And uh everybody agrees with this. So +now I have two parameters a tilda and b. + + align:start position:0% +now I have two parameters a tilda and b. + + + align:start position:0% +now I have two parameters a tilda and b. +And I'm gonna pretend that now X so now + + align:start position:0% +And I'm gonna pretend that now X so now + + + align:start position:0% +And I'm gonna pretend that now X so now +it's the role of X is played by X tilda + + align:start position:0% +it's the role of X is played by X tilda + + + align:start position:0% +it's the role of X is played by X tilda +which is now a uh which is now a + + align:start position:0% +which is now a uh which is now a + + + align:start position:0% +which is now a uh which is now a +centered random variable. Okay. So I'm + + align:start position:0% +centered random variable. Okay. So I'm + + + align:start position:0% +centered random variable. Okay. So I'm +going to call this guy a tilda. But for + + align:start position:0% +going to call this guy a tilda. But for + + + align:start position:0% +going to call this guy a tilda. But for +for my computations I'm going to call it + + align:start position:0% +for my computations I'm going to call it + + + align:start position:0% +for my computations I'm going to call it +a. So how do I find the minimum of this + + align:start position:0% +a. So how do I find the minimum of this + + + align:start position:0% +a. So how do I find the minimum of this +thing? + + align:start position:0% + + + + align:start position:0% + +Derivative equal to zero. Right? So here + + align:start position:0% +Derivative equal to zero. Right? So here + + + align:start position:0% +Derivative equal to zero. Right? So here +it's a quadratic thing. It's going to be + + align:start position:0% +it's a quadratic thing. It's going to be + + + align:start position:0% +it's a quadratic thing. It's going to be +like that. I take the derivative set it + + align:start position:0% +like that. I take the derivative set it + + + align:start position:0% +like that. I take the derivative set it +to zero. So I'm first going to take the + + align:start position:0% +to zero. So I'm first going to take the + + + align:start position:0% +to zero. So I'm first going to take the +derivative with respect to a and set it + + align:start position:0% +derivative with respect to a and set it + + + align:start position:0% +derivative with respect to a and set it +equal to zero. So that's equivalent to + + align:start position:0% +equal to zero. So that's equivalent to + + + align:start position:0% +equal to zero. So that's equivalent to +saying that the expectation of well here + + align:start position:0% +saying that the expectation of well here + + + align:start position:0% +saying that the expectation of well here +I'm going to pick up a two + + align:start position:0% +I'm going to pick up a two + + + align:start position:0% +I'm going to pick up a two +y minus + + align:start position:0% +y minus + + + align:start position:0% +y minus +um a + b x + + align:start position:0% +um a + b x + + + align:start position:0% +um a + b x +tilda + + align:start position:0% + + + + align:start position:0% + +is equal to zero. And then I also have + + align:start position:0% +is equal to zero. And then I also have + + + align:start position:0% +is equal to zero. And then I also have +that the derivative with respect to b is + + align:start position:0% +that the derivative with respect to b is + + + align:start position:0% +that the derivative with respect to b is +equal to zero which is equivalent to the + + align:start position:0% +equal to zero which is equivalent to the + + + align:start position:0% +equal to zero which is equivalent to the +expectation of well I have a negative + + align:start position:0% +expectation of well I have a negative + + + align:start position:0% +expectation of well I have a negative +sign somewhere so let me put it here - + + align:start position:0% +sign somewhere so let me put it here - + + + align:start position:0% +sign somewhere so let me put it here - +2x tilda y - + + align:start position:0% +2x tilda y - + + + align:start position:0% +2x tilda y - +a + b x tilda. + + align:start position:0% + + + + align:start position:0% + +Okay. See that's why I don't want to put + + align:start position:0% +Okay. See that's why I don't want to put + + + align:start position:0% +Okay. See that's why I don't want to put +too many parenthesis. Uh + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so I just took the derivative with + + align:start position:0% +so I just took the derivative with + + + align:start position:0% +so I just took the derivative with +respect to a which is just basically the + + align:start position:0% +respect to a which is just basically the + + + align:start position:0% +respect to a which is just basically the +square and then I have a negative one + + align:start position:0% +square and then I have a negative one + + + align:start position:0% +square and then I have a negative one +that comes out from inside and then I + + align:start position:0% +that comes out from inside and then I + + + align:start position:0% +that comes out from inside and then I +take the derivative with respect to b + + align:start position:0% +take the derivative with respect to b + + + align:start position:0% +take the derivative with respect to b +and I have since b has x tilda in factor + + align:start position:0% +and I have since b has x tilda in factor + + + align:start position:0% +and I have since b has x tilda in factor +it comes out as well right so the + + align:start position:0% +it comes out as well right so the + + + align:start position:0% +it comes out as well right so the +minus2's really won't matter for me + + align:start position:0% +minus2's really won't matter for me + + + align:start position:0% +minus2's really won't matter for me +and so now I have two equations the + + align:start position:0% +and so now I have two equations the + + + align:start position:0% +and so now I have two equations the +first equation well it's pretty simple + + align:start position:0% +first equation well it's pretty simple + + + align:start position:0% +first equation well it's pretty simple +It's just telling me that the + + align:start position:0% +It's just telling me that the + + + align:start position:0% +It's just telling me that the +expectation of y minus a is equal to + + align:start position:0% +expectation of y minus a is equal to + + + align:start position:0% +expectation of y minus a is equal to +zero. So what I know is that a is equal + + align:start position:0% +zero. So what I know is that a is equal + + + align:start position:0% +zero. So what I know is that a is equal +to the expectation + + align:start position:0% +to the expectation + + + align:start position:0% +to the expectation +of + + align:start position:0% +of + + + align:start position:0% +of +y. And really that was a tilda which + + align:start position:0% +y. And really that was a tilda which + + + align:start position:0% +y. And really that was a tilda which +implies that the a I want is actually + + align:start position:0% +implies that the a I want is actually + + + align:start position:0% +implies that the a I want is actually +equal to the expectation + + align:start position:0% +equal to the expectation + + + align:start position:0% +equal to the expectation +of uh + + align:start position:0% +of uh + + + align:start position:0% +of uh +y + + align:start position:0% + + + + align:start position:0% + +minus b * the expectation + + align:start position:0% +minus b * the expectation + + + align:start position:0% +minus b * the expectation +of x. + + align:start position:0% +of x. + + + align:start position:0% +of x. +Okay. + + align:start position:0% + + + + align:start position:0% + +just because a tilda is a plus b times + + align:start position:0% +just because a tilda is a plus b times + + + align:start position:0% +just because a tilda is a plus b times +the expectation of x. + + align:start position:0% + + + + align:start position:0% + +So that's for my a and then for my b I + + align:start position:0% +So that's for my a and then for my b I + + + align:start position:0% +So that's for my a and then for my b I +use the second one. So the second one + + align:start position:0% +use the second one. So the second one + + + align:start position:0% +use the second one. So the second one +tells me that the expectation of x tilda + + align:start position:0% +tells me that the expectation of x tilda + + + align:start position:0% +tells me that the expectation of x tilda +y + + align:start position:0% +y + + + align:start position:0% +y +is equal to a + b * the expectation of x + + align:start position:0% +is equal to a + b * the expectation of x + + + align:start position:0% +is equal to a + b * the expectation of x +tilda which is zero. Right? + + align:start position:0% + + + + align:start position:0% + +Okay. But this a is actually a tilda in + + align:start position:0% +Okay. But this a is actually a tilda in + + + align:start position:0% +Okay. But this a is actually a tilda in +this problem. So it's actually a plus b + + align:start position:0% +this problem. So it's actually a plus b + + + align:start position:0% +this problem. So it's actually a plus b +expectation of x. + + align:start position:0% + + + + align:start position:0% + +Now this is the expectation of the + + align:start position:0% +Now this is the expectation of the + + + align:start position:0% +Now this is the expectation of the +product of two random variables but x + + align:start position:0% +product of two random variables but x + + + align:start position:0% +product of two random variables but x +tilda is centered right? It's x minus + + align:start position:0% +tilda is centered right? It's x minus + + + align:start position:0% +tilda is centered right? It's x minus +expectation of x. So this thing is + + align:start position:0% +expectation of x. So this thing is + + + align:start position:0% +expectation of x. So this thing is +actually equal to the coariance between + + align:start position:0% +actually equal to the coariance between + + + align:start position:0% +actually equal to the coariance between +x and y by definition of coariance. + + align:start position:0% + + + + align:start position:0% + +So now I have everything I need, right? + + align:start position:0% +So now I have everything I need, right? + + + align:start position:0% +So now I have everything I need, right? +How do I just + + align:start position:0% +How do I just + + + align:start position:0% +How do I just +I'm sorry about that. Uh so I have + + align:start position:0% +I'm sorry about that. Uh so I have + + + align:start position:0% +I'm sorry about that. Uh so I have +everything I need. Now I'm just I have + + align:start position:0% +everything I need. Now I'm just I have + + + align:start position:0% +everything I need. Now I'm just I have +two equations with two unknowns. And uh + + align:start position:0% +two equations with two unknowns. And uh + + + align:start position:0% +two equations with two unknowns. And uh +all I have to do is to basically plug it + + align:start position:0% +all I have to do is to basically plug it + + + align:start position:0% +all I have to do is to basically plug it +in. So it's essentially telling me that + + align:start position:0% +in. So it's essentially telling me that + + + align:start position:0% +in. So it's essentially telling me that +the coariance of XY. So the first + + align:start position:0% +the coariance of XY. So the first + + + align:start position:0% +the coariance of XY. So the first +equation tells me that the coariance of + + align:start position:0% +equation tells me that the coariance of + + + align:start position:0% +equation tells me that the coariance of +XY is equal to A plus B expectation of + + align:start position:0% +XY is equal to A plus B expectation of + + + align:start position:0% +XY is equal to A plus B expectation of +X. But a is expectation of y minus b + + align:start position:0% +X. But a is expectation of y minus b + + + align:start position:0% +X. But a is expectation of y minus b +expectation of x. So uh + + align:start position:0% +expectation of x. So uh + + + align:start position:0% +expectation of x. So uh +it's well actually maybe I should start + + align:start position:0% +it's well actually maybe I should start + + + align:start position:0% +it's well actually maybe I should start +with b. + + align:start position:0% + + + + align:start position:0% + +Oh sorry sorry sorry. Okay I forgot one + + align:start position:0% +Oh sorry sorry sorry. Okay I forgot one + + + align:start position:0% +Oh sorry sorry sorry. Okay I forgot one +thing. Sorry this is not true. Right? I + + align:start position:0% +thing. Sorry this is not true. Right? I + + + align:start position:0% +thing. Sorry this is not true. Right? I +forgot this term. X tilda multiplies X + + align:start position:0% +forgot this term. X tilda multiplies X + + + align:start position:0% +forgot this term. X tilda multiplies X +tilda here. So what I'm left with is + + align:start position:0% +tilda here. So what I'm left with is + + + align:start position:0% +tilda here. So what I'm left with is +Xtilda. It's minus B times the + + align:start position:0% +Xtilda. It's minus B times the + + + align:start position:0% +Xtilda. It's minus B times the +expectation of X tilda squared. So + + align:start position:0% +expectation of X tilda squared. So + + + align:start position:0% +expectation of X tilda squared. So +that's actually minus B times the + + align:start position:0% +that's actually minus B times the + + + align:start position:0% +that's actually minus B times the +variance of X tilda because XTilda is + + align:start position:0% +variance of X tilda because XTilda is + + + align:start position:0% +variance of X tilda because XTilda is +already centered. Okay, which is + + align:start position:0% +already centered. Okay, which is + + + align:start position:0% +already centered. Okay, which is +actually the variance of X. + + align:start position:0% + + + + align:start position:0% + +Okay. So now I have that this thing is + + align:start position:0% +Okay. So now I have that this thing is + + + align:start position:0% +Okay. So now I have that this thing is +actually a plus b expectation of x minus + + align:start position:0% +actually a plus b expectation of x minus + + + align:start position:0% +actually a plus b expectation of x minus +b variance + + align:start position:0% +b variance + + + align:start position:0% +b variance +of x. + + align:start position:0% +of x. + + + align:start position:0% +of x. +And I also have that a + + align:start position:0% +And I also have that a + + + align:start position:0% +And I also have that a +is equal to expectation of y + + align:start position:0% +is equal to expectation of y + + + align:start position:0% +is equal to expectation of y +minus b expectation of x. + + align:start position:0% + + + + align:start position:0% + +Okay. So if I sum the two + + align:start position:0% +Okay. So if I sum the two + + + align:start position:0% +Okay. So if I sum the two +Right? So if I sum the two, those guys + + align:start position:0% +Right? So if I sum the two, those guys + + + align:start position:0% +Right? So if I sum the two, those guys +are going to cancel. + + align:start position:0% +are going to cancel. + + + align:start position:0% +are going to cancel. +Those guys are going to cancel. + + align:start position:0% +Those guys are going to cancel. + + + align:start position:0% +Those guys are going to cancel. +And so what I'm going to be left with is + + align:start position:0% +And so what I'm going to be left with is + + + align:start position:0% +And so what I'm going to be left with is +coariance of XY is equal to expectation + + align:start position:0% +coariance of XY is equal to expectation + + + align:start position:0% +coariance of XY is equal to expectation +of X, expectation of Y. + + align:start position:0% +of X, expectation of Y. + + + align:start position:0% +of X, expectation of Y. +And then I'm left with this term here + + align:start position:0% +And then I'm left with this term here + + + align:start position:0% +And then I'm left with this term here +minus B times the variance of X. + + align:start position:0% + + + + align:start position:0% + +And so that tells me that B, + + align:start position:0% +And so that tells me that B, + + + align:start position:0% +And so that tells me that B, +why do I still have the variance there? + + align:start position:0% + + + + align:start position:0% + +Y + + align:start position:0% + + + + align:start position:0% + +but sex still the center right so you + + align:start position:0% +but sex still the center right so you + + + align:start position:0% +but sex still the center right so you +just you just need to have one that's + + align:start position:0% +just you just need to have one that's + + + align:start position:0% +just you just need to have one that's +centered for this to work + + align:start position:0% +centered for this to work + + + align:start position:0% +centered for this to work +oh I see + + align:start position:0% +oh I see + + + align:start position:0% +oh I see +um + + align:start position:0% +um + + + align:start position:0% +um +right I mean you can check it but uh + + align:start position:0% +right I mean you can check it but uh + + + align:start position:0% +right I mean you can check it but uh +basically when you're going to have the + + align:start position:0% +basically when you're going to have the + + + align:start position:0% +basically when you're going to have the +product of the expectations you only + + align:start position:0% +product of the expectations you only + + + align:start position:0% +product of the expectations you only +need one of the two in the product to be + + align:start position:0% +need one of the two in the product to be + + + align:start position:0% +need one of the two in the product to be +zero so the product is zero so um okay + + align:start position:0% +zero so the product is zero so um okay + + + align:start position:0% +zero so the product is zero so um okay +why do kept my uh so I get a a and then + + align:start position:0% +why do kept my uh so I get a a and then + + + align:start position:0% +why do kept my uh so I get a a and then +the b expectation. Okay, so that's + + align:start position:0% +the b expectation. Okay, so that's + + + align:start position:0% +the b expectation. Okay, so that's +probably earlier that I made a mistake. + + align:start position:0% + + + + align:start position:0% + +So I get a So this was a tilda + + align:start position:0% +So I get a So this was a tilda + + + align:start position:0% +So I get a So this was a tilda +clear about the + + align:start position:0% + + + + align:start position:0% + +So that tells me that a tilda maybe it's + + align:start position:0% +So that tells me that a tilda maybe it's + + + align:start position:0% +So that tells me that a tilda maybe it's +not super fair of me to + + align:start position:0% + + + + align:start position:0% + +yeah okay I think I know where I made a + + align:start position:0% +yeah okay I think I know where I made a + + + align:start position:0% +yeah okay I think I know where I made a +mistake I should not have centered I + + align:start position:0% +mistake I should not have centered I + + + align:start position:0% +mistake I should not have centered I +wanted to make my life easier and I + + align:start position:0% +wanted to make my life easier and I + + + align:start position:0% +wanted to make my life easier and I +should not have done that and the reason + + align:start position:0% +should not have done that and the reason + + + align:start position:0% +should not have done that and the reason +is a tilda depends on b so when I take + + align:start position:0% +is a tilda depends on b so when I take + + + align:start position:0% +is a tilda depends on b so when I take +the derivative with respect to b what + + align:start position:0% +the derivative with respect to b what + + + align:start position:0% +the derivative with respect to b what +I'm left with here since a tilda depends + + align:start position:0% +I'm left with here since a tilda depends + + + align:start position:0% +I'm left with here since a tilda depends +on b when I take the derivative of this + + align:start position:0% +on b when I take the derivative of this + + + align:start position:0% +on b when I take the derivative of this +guy I actually don't get a tilda here + + align:start position:0% +guy I actually don't get a tilda here + + + align:start position:0% +guy I actually don't get a tilda here +but I really get um + + align:start position:0% + + + + align:start position:0% + +sorry so again this was not uh + + align:start position:0% +sorry so again this was not uh + + + align:start position:0% +sorry so again this was not uh +so that's the first one yeah so + + align:start position:0% + + + + align:start position:0% + +this is actually here, + + align:start position:0% +this is actually here, + + + align:start position:0% +this is actually here, +right? When I take the derivative with + + align:start position:0% +right? When I take the derivative with + + + align:start position:0% +right? When I take the derivative with +respect to B. + + align:start position:0% +respect to B. + + + align:start position:0% +respect to B. +And so now what I'm left with is that + + align:start position:0% +And so now what I'm left with is that + + + align:start position:0% +And so now what I'm left with is that +the expectation. So yeah, I'm basically + + align:start position:0% +the expectation. So yeah, I'm basically + + + align:start position:0% +the expectation. So yeah, I'm basically +left with nothing that helps. So um I'm + + align:start position:0% +left with nothing that helps. So um I'm + + + align:start position:0% +left with nothing that helps. So um I'm +sorry about that. Let's start from the + + align:start position:0% +sorry about that. Let's start from the + + + align:start position:0% +sorry about that. Let's start from the +the beginning because this is not + + align:start position:0% +the beginning because this is not + + + align:start position:0% +the beginning because this is not +getting us anywhere and any and a fix is + + align:start position:0% +getting us anywhere and any and a fix is + + + align:start position:0% +getting us anywhere and any and a fix is +not going to help. So let's just do it + + align:start position:0% +not going to help. So let's just do it + + + align:start position:0% +not going to help. So let's just do it +again. Sorry about that. So let's not + + align:start position:0% +again. Sorry about that. So let's not + + + align:start position:0% +again. Sorry about that. So let's not +center anything and just just do it + + align:start position:0% +center anything and just just do it + + + align:start position:0% +center anything and just just do it +brute force because we're gonna b x^ + + align:start position:0% +brute force because we're gonna b x^ + + + align:start position:0% +brute force because we're gonna b x^ +squ. All right, + + align:start position:0% +squ. All right, + + + align:start position:0% +squ. All right, +partial with respect to a is giving + + align:start position:0% +partial with respect to a is giving + + + align:start position:0% +partial with respect to a is giving +equals zero is equivalent. So my minus + + align:start position:0% +equals zero is equivalent. So my minus + + + align:start position:0% +equals zero is equivalent. So my minus +two is going to cancel, right? So I'm + + align:start position:0% +two is going to cancel, right? So I'm + + + align:start position:0% +two is going to cancel, right? So I'm +going to actually forget about this. So + + align:start position:0% +going to actually forget about this. So + + + align:start position:0% +going to actually forget about this. So +it's actually telling me that the + + align:start position:0% +it's actually telling me that the + + + align:start position:0% +it's actually telling me that the +expectation of y + + align:start position:0% +expectation of y + + + align:start position:0% +expectation of y +minus + + align:start position:0% +minus + + + align:start position:0% +minus +a + b x is equal to zero which is + + align:start position:0% +a + b x is equal to zero which is + + + align:start position:0% +a + b x is equal to zero which is +equivalent to a + b expectation of x is + + align:start position:0% +equivalent to a + b expectation of x is + + + align:start position:0% +equivalent to a + b expectation of x is +equal to the expectation of y. Now, if I + + align:start position:0% +equal to the expectation of y. Now, if I + + + align:start position:0% +equal to the expectation of y. Now, if I +take the derivative with respect to B + + align:start position:0% +take the derivative with respect to B + + + align:start position:0% +take the derivative with respect to B +and set it equal to zero, this is + + align:start position:0% +and set it equal to zero, this is + + + align:start position:0% +and set it equal to zero, this is +telling me that the expectation of uh + + align:start position:0% +telling me that the expectation of uh + + + align:start position:0% +telling me that the expectation of uh +well, it's the same thing except that + + align:start position:0% +well, it's the same thing except that + + + align:start position:0% +well, it's the same thing except that +this time I'm going to pull out an x. + + align:start position:0% + + + + align:start position:0% + +This guy is equal to zero. + + align:start position:0% +This guy is equal to zero. + + + align:start position:0% +This guy is equal to zero. +This guy is not here. And so that + + align:start position:0% +This guy is not here. And so that + + + align:start position:0% +This guy is not here. And so that +implies that the expectation + + align:start position:0% +implies that the expectation + + + align:start position:0% +implies that the expectation +of XY + + align:start position:0% + + + + align:start position:0% + +is equal + + align:start position:0% +is equal + + + align:start position:0% +is equal +to A * the expectation of X plus B times + + align:start position:0% +to A * the expectation of X plus B times + + + align:start position:0% +to A * the expectation of X plus B times +the expectation + + align:start position:0% +the expectation + + + align:start position:0% +the expectation +of X squ. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% + + + + align:start position:0% + +All right. So the first one is actually + + align:start position:0% +All right. So the first one is actually + + + align:start position:0% +All right. So the first one is actually +uh not giving me much. So I need to + + align:start position:0% +uh not giving me much. So I need to + + + align:start position:0% +uh not giving me much. So I need to +actually work with the two of those + + align:start position:0% +actually work with the two of those + + + align:start position:0% +actually work with the two of those +guys. So I'm going to take the first. So + + align:start position:0% +guys. So I'm going to take the first. So + + + align:start position:0% +guys. So I'm going to take the first. So +let me rewrite those two equal + + align:start position:0% +let me rewrite those two equal + + + align:start position:0% +let me rewrite those two equal +inequalities that I have. I have a plus + + align:start position:0% +inequalities that I have. I have a plus + + + align:start position:0% +inequalities that I have. I have a plus +b e of x is equal to e of y + + align:start position:0% +b e of x is equal to e of y + + + align:start position:0% +b e of x is equal to e of y +and then I have e of xy. + + align:start position:0% + + + + align:start position:0% + +Okay. And now the what I do is that I + + align:start position:0% +Okay. And now the what I do is that I + + + align:start position:0% +Okay. And now the what I do is that I +take the I multiply + + align:start position:0% +take the I multiply + + + align:start position:0% +take the I multiply +um + + align:start position:0% + + + + align:start position:0% + +this guy. So I want to cancel one of + + align:start position:0% +this guy. So I want to cancel one of + + + align:start position:0% +this guy. So I want to cancel one of +these things, right? So what I'm going + + align:start position:0% +these things, right? So what I'm going + + + align:start position:0% +these things, right? So what I'm going +to + + align:start position:0% +to + + + align:start position:0% +to +uh + + align:start position:0% + + + + align:start position:0% + +yeah, so I'm going to take this guy and + + align:start position:0% +yeah, so I'm going to take this guy and + + + align:start position:0% +yeah, so I'm going to take this guy and +I'm going to multiply it by E of X and + + align:start position:0% +I'm going to multiply it by E of X and + + + align:start position:0% +I'm going to multiply it by E of X and +take the difference. + + align:start position:0% +take the difference. + + + align:start position:0% +take the difference. +Okay. So I do times E of X and then I + + align:start position:0% +Okay. So I do times E of X and then I + + + align:start position:0% +Okay. So I do times E of X and then I +take the diff I take the I take the sum + + align:start position:0% +take the diff I take the I take the sum + + + align:start position:0% +take the diff I take the I take the sum +of those two and then those two terms + + align:start position:0% +of those two and then those two terms + + + align:start position:0% +of those two and then those two terms +are going to cancel. Okay. So then that + + align:start position:0% +are going to cancel. Okay. So then that + + + align:start position:0% +are going to cancel. Okay. So then that +tells me that B * E of X^ + + align:start position:0% +tells me that B * E of X^ + + + align:start position:0% +tells me that B * E of X^ +squared plus the expectation + + align:start position:0% +squared plus the expectation + + + align:start position:0% +squared plus the expectation +of X Y is equal to. + + align:start position:0% +of X Y is equal to. + + + align:start position:0% +of X Y is equal to. +So this guy uh is the one that + + align:start position:0% +So this guy uh is the one that + + + align:start position:0% +So this guy uh is the one that +cancelled. + + align:start position:0% + + + + align:start position:0% + +Then I get this guy here expectation of + + align:start position:0% +Then I get this guy here expectation of + + + align:start position:0% +Then I get this guy here expectation of +X times expectation of Y plus uh the guy + + align:start position:0% +X times expectation of Y plus uh the guy + + + align:start position:0% +X times expectation of Y plus uh the guy +that remains here which is uh B times + + align:start position:0% +that remains here which is uh B times + + + align:start position:0% +that remains here which is uh B times +the expectation of X^2. + + align:start position:0% + + + + align:start position:0% + +So here I have B expectation of X the + + align:start position:0% +So here I have B expectation of X the + + + align:start position:0% +So here I have B expectation of X the +whole thing squared and here I have B + + align:start position:0% +whole thing squared and here I have B + + + align:start position:0% +whole thing squared and here I have B +expectation of X squar. So if I pull + + align:start position:0% +expectation of X squar. So if I pull + + + align:start position:0% +expectation of X squar. So if I pull +this guy here what do I get? + + align:start position:0% +this guy here what do I get? + + + align:start position:0% +this guy here what do I get? +B times the variance of X. Okay so I'm + + align:start position:0% +B times the variance of X. Okay so I'm + + + align:start position:0% +B times the variance of X. Okay so I'm +going to move here and this guy here. + + align:start position:0% +going to move here and this guy here. + + + align:start position:0% +going to move here and this guy here. +When I move this guy here I get + + align:start position:0% +When I move this guy here I get + + + align:start position:0% +When I move this guy here I get +expectation of X time Y minus the + + align:start position:0% +expectation of X time Y minus the + + + align:start position:0% +expectation of X time Y minus the +expectation of X times the expectation + + align:start position:0% +expectation of X times the expectation + + + align:start position:0% +expectation of X times the expectation +of Y. So this is actually telling me + + align:start position:0% +of Y. So this is actually telling me + + + align:start position:0% +of Y. So this is actually telling me +that the covariance of X and Y is equal + + align:start position:0% +that the covariance of X and Y is equal + + + align:start position:0% +that the covariance of X and Y is equal +to B * the variance of X. + + align:start position:0% +to B * the variance of X. + + + align:start position:0% +to B * the variance of X. +And so that then that tells me that B + + align:start position:0% +And so that then that tells me that B + + + align:start position:0% +And so that then that tells me that B +is equal to uh coariance + + align:start position:0% +is equal to uh coariance + + + align:start position:0% +is equal to uh coariance +of XY divided by the variance of X. And + + align:start position:0% +of XY divided by the variance of X. And + + + align:start position:0% +of XY divided by the variance of X. And +that's why I actually need the variance + + align:start position:0% +that's why I actually need the variance + + + align:start position:0% +that's why I actually need the variance +of X to be non zero because I couldn't + + align:start position:0% +of X to be non zero because I couldn't + + + align:start position:0% +of X to be non zero because I couldn't +do that otherwise. + + align:start position:0% +do that otherwise. + + + align:start position:0% +do that otherwise. +And because if it was, it would mean + + align:start position:0% +And because if it was, it would mean + + + align:start position:0% +And because if it was, it would mean +that B should be plus infinity, which is + + align:start position:0% +that B should be plus infinity, which is + + + align:start position:0% +that B should be plus infinity, which is +what the limit of this guy is when the + + align:start position:0% +what the limit of this guy is when the + + + align:start position:0% +what the limit of this guy is when the +variance goes to zero. Okay? Or negative + + align:start position:0% +variance goes to zero. Okay? Or negative + + + align:start position:0% +variance goes to zero. Okay? Or negative +infinity. I cannot sort them out. + + align:start position:0% +infinity. I cannot sort them out. + + + align:start position:0% +infinity. I cannot sort them out. +All right? So I'm sorry about the mess, + + align:start position:0% +All right? So I'm sorry about the mess, + + + align:start position:0% +All right? So I'm sorry about the mess, +but uh that should be uh more clear. + + align:start position:0% +but uh that should be uh more clear. + + + align:start position:0% +but uh that should be uh more clear. +Then a of course you can write it as a + + align:start position:0% +Then a of course you can write it as a + + + align:start position:0% +Then a of course you can write it as a +by plugging in the value of b. So you + + align:start position:0% +by plugging in the value of b. So you + + + align:start position:0% +by plugging in the value of b. So you +know it it's only a function of your + + align:start position:0% +know it it's only a function of your + + + align:start position:0% +know it it's only a function of your +distribution, right? So what are the + + align:start position:0% +distribution, right? So what are the + + + align:start position:0% +distribution, right? So what are the +characteristics of the distri? So + + align:start position:0% +characteristics of the distri? So + + + align:start position:0% +characteristics of the distri? So +distribution can have a bunch of things. + + align:start position:0% +distribution can have a bunch of things. + + + align:start position:0% +distribution can have a bunch of things. +It can have moments of order four of + + align:start position:0% +It can have moments of order four of + + + align:start position:0% +It can have moments of order four of +order 26. It can have heavy tails or + + align:start position:0% +order 26. It can have heavy tails or + + + align:start position:0% +order 26. It can have heavy tails or +light tails. But when you compute le + + align:start position:0% +light tails. But when you compute le + + + align:start position:0% +light tails. But when you compute le +squares, the only thing that matters are + + align:start position:0% +squares, the only thing that matters are + + + align:start position:0% +squares, the only thing that matters are +the variance of x, the expectation of + + align:start position:0% +the variance of x, the expectation of + + + align:start position:0% +the variance of x, the expectation of +the individual ones. And really what + + align:start position:0% +the individual ones. And really what + + + align:start position:0% +the individual ones. And really what +captures how y changes when you change x + + align:start position:0% +captures how y changes when you change x + + + align:start position:0% +captures how y changes when you change x +is is captured in the coariance. The + + align:start position:0% +is is captured in the coariance. The + + + align:start position:0% +is is captured in the coariance. The +rest is really just normalization, + + align:start position:0% +rest is really just normalization, + + + align:start position:0% +rest is really just normalization, +right? It's just telling you I want + + align:start position:0% +right? It's just telling you I want + + + align:start position:0% +right? It's just telling you I want +things to cross the y-axis at the right + + align:start position:0% +things to cross the y-axis at the right + + + align:start position:0% +things to cross the y-axis at the right +place. I want things to cross the x-axis + + align:start position:0% +place. I want things to cross the x-axis + + + align:start position:0% +place. I want things to cross the x-axis +at the right place. But the slope is + + align:start position:0% +at the right place. But the slope is + + + align:start position:0% +at the right place. But the slope is +really captured by how much more + + align:start position:0% +really captured by how much more + + + align:start position:0% +really captured by how much more +coariance you have relative to the + + align:start position:0% +coariance you have relative to the + + + align:start position:0% +coariance you have relative to the +variance of x. Okay. So this is + + align:start position:0% +variance of x. Okay. So this is + + + align:start position:0% +variance of x. Okay. So this is +essentially setting the scale for the + + align:start position:0% +essentially setting the scale for the + + + align:start position:0% +essentially setting the scale for the +x-axis and this is telling you for a + + align:start position:0% +x-axis and this is telling you for a + + + align:start position:0% +x-axis and this is telling you for a +unit scale. This is the uh unit of y + + align:start position:0% +unit scale. This is the uh unit of y + + + align:start position:0% +unit scale. This is the uh unit of y +that you're changing. + + align:start position:0% +that you're changing. + + + align:start position:0% +that you're changing. +Okay. So we have explicit forms and what + + align:start position:0% +Okay. So we have explicit forms and what + + + align:start position:0% +Okay. So we have explicit forms and what +I could do if I wanted to estimate those + + align:start position:0% +I could do if I wanted to estimate those + + + align:start position:0% +I could do if I wanted to estimate those +things is just say well again we have + + align:start position:0% +things is just say well again we have + + + align:start position:0% +things is just say well again we have +expectations right the coariance is the + + align:start position:0% +expectations right the coariance is the + + + align:start position:0% +expectations right the coariance is the +expectation of XY minus the product of + + align:start position:0% +expectation of XY minus the product of + + + align:start position:0% +expectation of XY minus the product of +the expectations I could replace + + align:start position:0% +the expectations I could replace + + + align:start position:0% +the expectations I could replace +expectations by averages and get an + + align:start position:0% +expectations by averages and get an + + + align:start position:0% +expectations by averages and get an +empirical coariance just like we can + + align:start position:0% +empirical coariance just like we can + + + align:start position:0% +empirical coariance just like we can +replace the expectations for the + + align:start position:0% +replace the expectations for the + + + align:start position:0% +replace the expectations for the +variance and get a sample coariance and + + align:start position:0% +variance and get a sample coariance and + + + align:start position:0% +variance and get a sample coariance and +this is basically what we're going to be + + align:start position:0% +this is basically what we're going to be + + + align:start position:0% +this is basically what we're going to be +doing all right this is essentially what + + align:start position:0% +doing all right this is essentially what + + + align:start position:0% +doing all right this is essentially what +you want the problem is that if you view + + align:start position:0% +you want the problem is that if you view + + + align:start position:0% +you want the problem is that if you view +it that way you sort of prevent yourself + + align:start position:0% +it that way you sort of prevent yourself + + + align:start position:0% +it that way you sort of prevent yourself +from being able to solve the multivaried + + align:start position:0% +from being able to solve the multivaried + + + align:start position:0% +from being able to solve the multivaried +problem because it's only in the + + align:start position:0% +problem because it's only in the + + + align:start position:0% +problem because it's only in the +univaried problem that you have closed + + align:start position:0% +univaried problem that you have closed + + + align:start position:0% +univaried problem that you have closed +form solutions for your problem. But if + + align:start position:0% +form solutions for your problem. But if + + + align:start position:0% +form solutions for your problem. But if +you actually go to multivariate, this is + + align:start position:0% +you actually go to multivariate, this is + + + align:start position:0% +you actually go to multivariate, this is +not where you want to replace + + align:start position:0% +not where you want to replace + + + align:start position:0% +not where you want to replace +expectations by averages. You actually + + align:start position:0% +expectations by averages. You actually + + + align:start position:0% +expectations by averages. You actually +want to replace expectation by averages + + align:start position:0% +want to replace expectation by averages + + + align:start position:0% +want to replace expectation by averages +here. + + align:start position:0% + + + + align:start position:0% + +And once you do it here, then you can + + align:start position:0% +And once you do it here, then you can + + + align:start position:0% +And once you do it here, then you can +actually just solve the minimization + + align:start position:0% +actually just solve the minimization + + + align:start position:0% +actually just solve the minimization +problem. All right. + + align:start position:0% + + + + align:start position:0% + +Okay. So, um, + + align:start position:0% +Okay. So, um, + + + align:start position:0% +Okay. So, um, +one thing that arises from this guy + + align:start position:0% +one thing that arises from this guy + + + align:start position:0% +one thing that arises from this guy +is that + + align:start position:0% + + + + align:start position:0% + +this is an interesting formula, + + align:start position:0% + + + + align:start position:0% + +right? Think about it. If I if I have + + align:start position:0% + + + + align:start position:0% + +that y is a + b x plus some noise. Now + + align:start position:0% +that y is a + b x plus some noise. Now + + + align:start position:0% +that y is a + b x plus some noise. Now +not things are no longer on the on + + align:start position:0% +not things are no longer on the on + + + align:start position:0% +not things are no longer on the on +something. I have that y is equal to a + + + align:start position:0% +something. I have that y is equal to a + + + + align:start position:0% +something. I have that y is equal to a + +bx plus some noise which is usually + + align:start position:0% +bx plus some noise which is usually + + + align:start position:0% +bx plus some noise which is usually +denoted by epsilon. So that's the + + align:start position:0% +denoted by epsilon. So that's the + + + align:start position:0% +denoted by epsilon. So that's the +distribution right? If I tell you the + + align:start position:0% +distribution right? If I tell you the + + + align:start position:0% +distribution right? If I tell you the +distribution of X and I say Y is a plus + + align:start position:0% +distribution of X and I say Y is a plus + + + align:start position:0% +distribution of X and I say Y is a plus +bx plus epsilon I tell you the + + align:start position:0% +bx plus epsilon I tell you the + + + align:start position:0% +bx plus epsilon I tell you the +distribution of Y and if maybe that + + align:start position:0% +distribution of Y and if maybe that + + + align:start position:0% +distribution of Y and if maybe that +those two are independent you have a + + align:start position:0% +those two are independent you have a + + + align:start position:0% +those two are independent you have a +distribution on Y. + + align:start position:0% +distribution on Y. + + + align:start position:0% +distribution on Y. +So what happens is that I can actually + + align:start position:0% +So what happens is that I can actually + + + align:start position:0% +So what happens is that I can actually +always say well you know this is + + align:start position:0% +always say well you know this is + + + align:start position:0% +always say well you know this is +equivalent to saying that epsilon is + + align:start position:0% +equivalent to saying that epsilon is + + + align:start position:0% +equivalent to saying that epsilon is +equal to y minus a plus bx right + + align:start position:0% +equal to y minus a plus bx right + + + align:start position:0% +equal to y minus a plus bx right +I can always write this it's just uh I + + align:start position:0% +I can always write this it's just uh I + + + align:start position:0% +I can always write this it's just uh I +mean it's the tology + + align:start position:0% +mean it's the tology + + + align:start position:0% +mean it's the tology +but here for those guys this is not for + + align:start position:0% +but here for those guys this is not for + + + align:start position:0% +but here for those guys this is not for +any guy right this is really for the + + align:start position:0% +any guy right this is really for the + + + align:start position:0% +any guy right this is really for the +best fit a and b those ones that satisfy + + align:start position:0% +best fit a and b those ones that satisfy + + + align:start position:0% +best fit a and b those ones that satisfy +this gradient is equal to zero thing + + align:start position:0% +this gradient is equal to zero thing + + + align:start position:0% +this gradient is equal to zero thing +then what we had is that the expectation + + align:start position:0% +then what we had is that the expectation + + + align:start position:0% +then what we had is that the expectation +of epsilon + + align:start position:0% +of epsilon + + + align:start position:0% +of epsilon +was equal to expectation of y minus a + + + align:start position:0% +was equal to expectation of y minus a + + + + align:start position:0% +was equal to expectation of y minus a + +b expectation of x right by linearity of + + align:start position:0% +b expectation of x right by linearity of + + + align:start position:0% +b expectation of x right by linearity of +the expectation which was equal to zero. + + align:start position:0% +the expectation which was equal to zero. + + + align:start position:0% +the expectation which was equal to zero. +So for this best fit + + align:start position:0% +So for this best fit + + + align:start position:0% +So for this best fit +we have zero. + + align:start position:0% +we have zero. + + + align:start position:0% +we have zero. +Now the coariance between x and y + + align:start position:0% + + + + align:start position:0% + +uh between sorry x and epsilon + + align:start position:0% +uh between sorry x and epsilon + + + align:start position:0% +uh between sorry x and epsilon +is what? Well, it's the coariance + + align:start position:0% +is what? Well, it's the coariance + + + align:start position:0% +is what? Well, it's the coariance +between X and well epsilon was Y minus A + + align:start position:0% +between X and well epsilon was Y minus A + + + align:start position:0% +between X and well epsilon was Y minus A ++ B X. + + align:start position:0% ++ B X. + + + align:start position:0% ++ B X. +Okay. Now the coariance is by linear. So + + align:start position:0% +Okay. Now the coariance is by linear. So + + + align:start position:0% +Okay. Now the coariance is by linear. So +what I have is that the coariance of + + align:start position:0% +what I have is that the coariance of + + + align:start position:0% +what I have is that the coariance of +this is the coariance of X and time Y + + align:start position:0% +this is the coariance of X and time Y + + + align:start position:0% +this is the coariance of X and time Y +sorry of X and Y minus the coariance + + align:start position:0% +sorry of X and Y minus the coariance + + + align:start position:0% +sorry of X and Y minus the coariance +well minus A + B coariance + + align:start position:0% +well minus A + B coariance + + + align:start position:0% +well minus A + B coariance +of X and X + + align:start position:0% +of X and X + + + align:start position:0% +of X and X +which is + + align:start position:0% + + + + align:start position:0% + +the variance of X + + align:start position:0% + + + + align:start position:0% + +coariance of XY minus A plus be co + + align:start position:0% +coariance of XY minus A plus be co + + + align:start position:0% +coariance of XY minus A plus be co +variance of x + + align:start position:0% +variance of x + + + align:start position:0% +variance of x +and let + + align:start position:0% + + + + align:start position:0% + +coariance of uh okay I didn't write it + + align:start position:0% +coariance of uh okay I didn't write it + + + align:start position:0% +coariance of uh okay I didn't write it +so here I have coariance of xy is equal + + align:start position:0% +so here I have coariance of xy is equal + + + align:start position:0% +so here I have coariance of xy is equal +to b variance of x right + + align:start position:0% +to b variance of x right + + + align:start position:0% +to b variance of x right +uh so + + align:start position:0% + + + + align:start position:0% + +why uh what did Okay. + + align:start position:0% + + + + align:start position:0% + +Coance of XY. Yeah, that's because I + + align:start position:0% +Coance of XY. Yeah, that's because I + + + align:start position:0% +Coance of XY. Yeah, that's because I +cannot do that with the coariance. Um, + + align:start position:0% + + + + align:start position:0% + +yeah, I have those averages again. Um, + + align:start position:0% +yeah, I have those averages again. Um, + + + align:start position:0% +yeah, I have those averages again. Um, +no, because this is centered, right? + + align:start position:0% +no, because this is centered, right? + + + align:start position:0% +no, because this is centered, right? +Sorry, this is centered. So this is + + align:start position:0% +Sorry, this is centered. So this is + + + align:start position:0% +Sorry, this is centered. So this is +actually equal to the expectation of x * + + align:start position:0% +actually equal to the expectation of x * + + + align:start position:0% +actually equal to the expectation of x * +y - a + bx + + align:start position:0% + + + + align:start position:0% + +right the the coariance is equal to the + + align:start position:0% +right the the coariance is equal to the + + + align:start position:0% +right the the coariance is equal to the +product just because this right hand + + align:start position:0% +product just because this right hand + + + align:start position:0% +product just because this right hand +side is actually centered. So this is + + align:start position:0% +side is actually centered. So this is + + + align:start position:0% +side is actually centered. So this is +the expectation of x * y + + align:start position:0% +the expectation of x * y + + + align:start position:0% +the expectation of x * y +minus + + align:start position:0% +minus + + + align:start position:0% +minus +the expectation of a uh * x + + align:start position:0% +the expectation of a uh * x + + + align:start position:0% +the expectation of a uh * x +a * the expectation of x plus b + + align:start position:0% +a * the expectation of x plus b + + + align:start position:0% +a * the expectation of x plus b +minus b * the expectation of x^2. + + align:start position:0% + + + + align:start position:0% + +Well actually maybe I should not really + + align:start position:0% +Well actually maybe I should not really + + + align:start position:0% +Well actually maybe I should not really +go too far. + + align:start position:0% + + + + align:start position:0% + +So this is actually the one that I need. + + align:start position:0% +So this is actually the one that I need. + + + align:start position:0% +So this is actually the one that I need. +But if I stop here, + + align:start position:0% + + + + align:start position:0% + +this is actually equal to zero, right? + + align:start position:0% +this is actually equal to zero, right? + + + align:start position:0% +this is actually equal to zero, right? +Those are the same equations. + + align:start position:0% + + + + align:start position:0% + +Okay. Yeah. + + align:start position:0% + + + + align:start position:0% + +So we're just saying that if I actually + + align:start position:0% +So we're just saying that if I actually + + + align:start position:0% +So we're just saying that if I actually +believed that this best fit was the one + + align:start position:0% +believed that this best fit was the one + + + align:start position:0% +believed that this best fit was the one +that gave me the right parameters, what + + align:start position:0% +that gave me the right parameters, what + + + align:start position:0% +that gave me the right parameters, what +would that imply on the noise itself on + + align:start position:0% +would that imply on the noise itself on + + + align:start position:0% +would that imply on the noise itself on +this epsilon? So here we're actually + + align:start position:0% +this epsilon? So here we're actually + + + align:start position:0% +this epsilon? So here we're actually +just trying to find some necessary + + align:start position:0% +just trying to find some necessary + + + align:start position:0% +just trying to find some necessary +condition for the noise to hold for the + + align:start position:0% +condition for the noise to hold for the + + + align:start position:0% +condition for the noise to hold for the +noise. And so those conditions are that + + align:start position:0% +noise. And so those conditions are that + + + align:start position:0% +noise. And so those conditions are that +first the expectation is zero. That's + + align:start position:0% +first the expectation is zero. That's + + + align:start position:0% +first the expectation is zero. That's +what we got here. And then that the + + align:start position:0% +what we got here. And then that the + + + align:start position:0% +what we got here. And then that the +coariance between the noise and x has to + + align:start position:0% +coariance between the noise and x has to + + + align:start position:0% +coariance between the noise and x has to +be zero as well. Okay. So those are + + align:start position:0% +be zero as well. Okay. So those are + + + align:start position:0% +be zero as well. Okay. So those are +actually conditions that the noise must + + align:start position:0% +actually conditions that the noise must + + + align:start position:0% +actually conditions that the noise must +satisfy. But the noise was just not + + align:start position:0% +satisfy. But the noise was just not + + + align:start position:0% +satisfy. But the noise was just not +really defined as noise itself. We were + + align:start position:0% +really defined as noise itself. We were + + + align:start position:0% +really defined as noise itself. We were +just saying okay if we're going to put + + align:start position:0% +just saying okay if we're going to put + + + align:start position:0% +just saying okay if we're going to put +some assumptions on X on the epsilon + + align:start position:0% +some assumptions on X on the epsilon + + + align:start position:0% +some assumptions on X on the epsilon +what do we better have? So the first one + + align:start position:0% +what do we better have? So the first one + + + align:start position:0% +what do we better have? So the first one +is that it's centered which is good + + align:start position:0% +is that it's centered which is good + + + align:start position:0% +is that it's centered which is good +because otherwise the noise would shift + + align:start position:0% +because otherwise the noise would shift + + + align:start position:0% +because otherwise the noise would shift +everything. So now when you look at a a + + align:start position:0% +everything. So now when you look at a a + + + align:start position:0% +everything. So now when you look at a a +a linear regression model typically if + + align:start position:0% +a linear regression model typically if + + + align:start position:0% +a linear regression model typically if +you look if you open a book it doesn't + + align:start position:0% +you look if you open a book it doesn't + + + align:start position:0% +you look if you open a book it doesn't +start by saying let the noise be the + + align:start position:0% +start by saying let the noise be the + + + align:start position:0% +start by saying let the noise be the +difference between y and what I actually + + align:start position:0% +difference between y and what I actually + + + align:start position:0% +difference between y and what I actually +want y to be. It says let y be a plus bx + + align:start position:0% +want y to be. It says let y be a plus bx + + + align:start position:0% +want y to be. It says let y be a plus bx +plus epsilon. So conversely if we assume + + align:start position:0% +plus epsilon. So conversely if we assume + + + align:start position:0% +plus epsilon. So conversely if we assume +that this is the model that we have + + align:start position:0% +that this is the model that we have + + + align:start position:0% +that this is the model that we have +then we're going to have to assume that + + align:start position:0% +then we're going to have to assume that + + + align:start position:0% +then we're going to have to assume that +epsilon we're going to assume that + + align:start position:0% +epsilon we're going to assume that + + + align:start position:0% +epsilon we're going to assume that +epsilon is centered and that the + + align:start position:0% +epsilon is centered and that the + + + align:start position:0% +epsilon is centered and that the +coariance between x and epsilon is zero. + + align:start position:0% +coariance between x and epsilon is zero. + + + align:start position:0% +coariance between x and epsilon is zero. +Actually often we're going to assume + + align:start position:0% +Actually often we're going to assume + + + align:start position:0% +Actually often we're going to assume +much more. And one way to ensure that + + align:start position:0% +much more. And one way to ensure that + + + align:start position:0% +much more. And one way to ensure that +those two things are satisfied is to + + align:start position:0% +those two things are satisfied is to + + + align:start position:0% +those two things are satisfied is to +assume that x is independent of epsilon. + + align:start position:0% +assume that x is independent of epsilon. + + + align:start position:0% +assume that x is independent of epsilon. +For example, if you assume that X is + + align:start position:0% +For example, if you assume that X is + + + align:start position:0% +For example, if you assume that X is +independent of epsilon, of course, the + + align:start position:0% +independent of epsilon, of course, the + + + align:start position:0% +independent of epsilon, of course, the +coariance is going to be zero + + align:start position:0% +coariance is going to be zero + + + align:start position:0% +coariance is going to be zero +or we might assume that the conditional + + align:start position:0% +or we might assume that the conditional + + + align:start position:0% +or we might assume that the conditional +expectation of e of epsilon given x is + + align:start position:0% +expectation of e of epsilon given x is + + + align:start position:0% +expectation of e of epsilon given x is +equal to zero. Then that implies that + + align:start position:0% +equal to zero. Then that implies that + + + align:start position:0% +equal to zero. Then that implies that +okay now the fact that it's centered is + + align:start position:0% +okay now the fact that it's centered is + + + align:start position:0% +okay now the fact that it's centered is +one thing. So if we make this + + align:start position:0% +one thing. So if we make this + + + align:start position:0% +one thing. So if we make this +assumption, + + align:start position:0% +assumption, + + + align:start position:0% +assumption, +what the only thing it's telling us is + + align:start position:0% +what the only thing it's telling us is + + + align:start position:0% +what the only thing it's telling us is +that those abs that come right, we + + align:start position:0% +that those abs that come right, we + + + align:start position:0% +that those abs that come right, we +started from there. Y is equal to A plus + + align:start position:0% +started from there. Y is equal to A plus + + + align:start position:0% +started from there. Y is equal to A plus +B X plus some epsilon for some A and + + align:start position:0% +B X plus some epsilon for some A and + + + align:start position:0% +B X plus some epsilon for some A and +some B. What it turns out is that those + + align:start position:0% +some B. What it turns out is that those + + + align:start position:0% +some B. What it turns out is that those +ep's and B's are actually the ones that + + align:start position:0% +ep's and B's are actually the ones that + + + align:start position:0% +ep's and B's are actually the ones that +you would get by solving this + + align:start position:0% +you would get by solving this + + + align:start position:0% +you would get by solving this +expectation of square thing. + + align:start position:0% +expectation of square thing. + + + align:start position:0% +expectation of square thing. +All right. So when you asked back when + + align:start position:0% +All right. So when you asked back when + + + align:start position:0% +All right. So when you asked back when +you were following Yeah. So uh when you + + align:start position:0% +you were following Yeah. So uh when you + + + align:start position:0% +you were following Yeah. So uh when you +asked uh you know why don't we take the + + align:start position:0% +asked uh you know why don't we take the + + + align:start position:0% +asked uh you know why don't we take the +square for example or the power four or + + align:start position:0% +square for example or the power four or + + + align:start position:0% +square for example or the power four or +something like this then here I'm saying + + align:start position:0% +something like this then here I'm saying + + + align:start position:0% +something like this then here I'm saying +well if I have y is equal to a plus bx I + + align:start position:0% +well if I have y is equal to a plus bx I + + + align:start position:0% +well if I have y is equal to a plus bx I +don't actually need to put too much + + align:start position:0% +don't actually need to put too much + + + align:start position:0% +don't actually need to put too much +assumptions on epsilon if epsilon is + + align:start position:0% +assumptions on epsilon if epsilon is + + + align:start position:0% +assumptions on epsilon if epsilon is +actually satisfying those two things + + align:start position:0% +actually satisfying those two things + + + align:start position:0% +actually satisfying those two things +expectation is equal to zero and + + align:start position:0% +expectation is equal to zero and + + + align:start position:0% +expectation is equal to zero and +coariance with x is equal to zero then + + align:start position:0% +coariance with x is equal to zero then + + + align:start position:0% +coariance with x is equal to zero then +the right a and b that I'm looking for + + align:start position:0% +the right a and b that I'm looking for + + + align:start position:0% +the right a and b that I'm looking for +actually the ones that come with the + + align:start position:0% +actually the ones that come with the + + + align:start position:0% +actually the ones that come with the +square not with power four or power 25. + + align:start position:0% +square not with power four or power 25. + + + align:start position:0% +square not with power four or power 25. +Okay, so those are actually pretty weak + + align:start position:0% +Okay, so those are actually pretty weak + + + align:start position:0% +Okay, so those are actually pretty weak +assumptions. If we want to do inference, + + align:start position:0% +assumptions. If we want to do inference, + + + align:start position:0% +assumptions. If we want to do inference, +we're going to have to assume slightly + + align:start position:0% +we're going to have to assume slightly + + + align:start position:0% +we're going to have to assume slightly +more. If we want to use t distributions + + align:start position:0% +more. If we want to use t distributions + + + align:start position:0% +more. If we want to use t distributions +at some point, for example, and we will, + + align:start position:0% +at some point, for example, and we will, + + + align:start position:0% +at some point, for example, and we will, +we're going to have to assume that + + align:start position:0% +we're going to have to assume that + + + align:start position:0% +we're going to have to assume that +epsilon has a Gaussian distribution. So + + align:start position:0% +epsilon has a Gaussian distribution. So + + + align:start position:0% +epsilon has a Gaussian distribution. So +if you want to start doing more + + align:start position:0% +if you want to start doing more + + + align:start position:0% +if you want to start doing more +statistics beyond just like doing this + + align:start position:0% +statistics beyond just like doing this + + + align:start position:0% +statistics beyond just like doing this +le square thing, which is minimizing the + + align:start position:0% +le square thing, which is minimizing the + + + align:start position:0% +le square thing, which is minimizing the +square criterion, you're actually going + + align:start position:0% +square criterion, you're actually going + + + align:start position:0% +square criterion, you're actually going +to have to put more assumptions. But + + align:start position:0% +to have to put more assumptions. But + + + align:start position:0% +to have to put more assumptions. But +right now, we did not need them. we only + + align:start position:0% +right now, we did not need them. we only + + + align:start position:0% +right now, we did not need them. we only +need that epsilon has mean zero and + + align:start position:0% +need that epsilon has mean zero and + + + align:start position:0% +need that epsilon has mean zero and +coariance zero with x. + + align:start position:0% + + + + align:start position:0% + +Okay, so let's start with so that was + + align:start position:0% +Okay, so let's start with so that was + + + align:start position:0% +Okay, so let's start with so that was +basically probabilistic, right? We're + + align:start position:0% +basically probabilistic, right? We're + + + align:start position:0% +basically probabilistic, right? We're +trying to say if I were to do + + align:start position:0% +trying to say if I were to do + + + align:start position:0% +trying to say if I were to do +probability and I were trying to model + + align:start position:0% +probability and I were trying to model + + + align:start position:0% +probability and I were trying to model +the relationship between two random + + align:start position:0% +the relationship between two random + + + align:start position:0% +the relationship between two random +variables x and y in the form y is a + + align:start position:0% +variables x and y in the form y is a + + + align:start position:0% +variables x and y in the form y is a +plus bx plus some noise. This is what + + align:start position:0% +plus bx plus some noise. This is what + + + align:start position:0% +plus bx plus some noise. This is what +would come out. Everything was + + align:start position:0% +would come out. Everything was + + + align:start position:0% +would come out. Everything was +expectations. There was no data + + align:start position:0% +expectations. There was no data + + + align:start position:0% +expectations. There was no data +involved. So now let's go to the data + + align:start position:0% +involved. So now let's go to the data + + + align:start position:0% +involved. So now let's go to the data +problem which is now I do not have I do + + align:start position:0% +problem which is now I do not have I do + + + align:start position:0% +problem which is now I do not have I do +not know what the expectations are in + + align:start position:0% +not know what the expectations are in + + + align:start position:0% +not know what the expectations are in +particular I don't know what the + + align:start position:0% +particular I don't know what the + + + align:start position:0% +particular I don't know what the +coariance of x and y is and I don't know + + align:start position:0% +coariance of x and y is and I don't know + + + align:start position:0% +coariance of x and y is and I don't know +what the expectation of x and the + + align:start position:0% +what the expectation of x and the + + + align:start position:0% +what the expectation of x and the +expectation of y of y are so I have data + + align:start position:0% +expectation of y of y are so I have data + + + align:start position:0% +expectation of y of y are so I have data +to do that so how am I going to do this + + align:start position:0% + + + + align:start position:0% + +well I'm just going to say well if I + + align:start position:0% +well I'm just going to say well if I + + + align:start position:0% +well I'm just going to say well if I +want x1 y1 + + align:start position:0% + + + + align:start position:0% + +xn and yn and I'm going to assume that + + align:start position:0% +xn and yn and I'm going to assume that + + + align:start position:0% +xn and yn and I'm going to assume that +they're iid + + align:start position:0% +they're iid + + + align:start position:0% +they're iid +and I'm actually going to assume that + + align:start position:0% +and I'm actually going to assume that + + + align:start position:0% +and I'm actually going to assume that +they have some model right so I'm going + + align:start position:0% +they have some model right so I'm going + + + align:start position:0% +they have some model right so I'm going +to assume that I have that a so that yi + + align:start position:0% +to assume that I have that a so that yi + + + align:start position:0% +to assume that I have that a so that yi +follows the same model + + align:start position:0% + + + + align:start position:0% + +so epsilon i and I want say that epsil + + align:start position:0% +so epsilon i and I want say that epsil + + + align:start position:0% +so epsilon i and I want say that epsil +expectation of epsilon i is zero and + + align:start position:0% +expectation of epsilon i is zero and + + + align:start position:0% +expectation of epsilon i is zero and +coariance of x i ep epsilon i is equal + + align:start position:0% +coariance of x i ep epsilon i is equal + + + align:start position:0% +coariance of x i ep epsilon i is equal +to zero so I'm going to put the same + + align:start position:0% +to zero so I'm going to put the same + + + align:start position:0% +to zero so I'm going to put the same +model on all the data. So you can see + + align:start position:0% +model on all the data. So you can see + + + align:start position:0% +model on all the data. So you can see +that A is not AI and B is not BI. It's + + align:start position:0% +that A is not AI and B is not BI. It's + + + align:start position:0% +that A is not AI and B is not BI. It's +the same. So as my data increases, I + + align:start position:0% +the same. So as my data increases, I + + + align:start position:0% +the same. So as my data increases, I +should be able to recover the correct + + align:start position:0% +should be able to recover the correct + + + align:start position:0% +should be able to recover the correct +things as the size of my data increases. + + align:start position:0% +things as the size of my data increases. + + + align:start position:0% +things as the size of my data increases. +Okay, so this is what uh the statistical + + align:start position:0% +Okay, so this is what uh the statistical + + + align:start position:0% +Okay, so this is what uh the statistical +problem look like. You're given the + + align:start position:0% +problem look like. You're given the + + + align:start position:0% +problem look like. You're given the +points. + + align:start position:0% +points. + + + align:start position:0% +points. +There is a true line from which this + + align:start position:0% +There is a true line from which this + + + align:start position:0% +There is a true line from which this +point was generated, right? There was + + align:start position:0% +point was generated, right? There was + + + align:start position:0% +point was generated, right? There was +this line. There was a true AB + + align:start position:0% +this line. There was a true AB + + + align:start position:0% +this line. There was a true AB +that I used to draw this plot and that + + align:start position:0% +that I used to draw this plot and that + + + align:start position:0% +that I used to draw this plot and that +was the line. So first I picked an x say + + align:start position:0% +was the line. So first I picked an x say + + + align:start position:0% +was the line. So first I picked an x say +uniformly at random on this interval 0 + + align:start position:0% +uniformly at random on this interval 0 + + + align:start position:0% +uniformly at random on this interval 0 +to two. Let's say that was this one. + + align:start position:0% +to two. Let's say that was this one. + + + align:start position:0% +to two. Let's say that was this one. +Then I I said well I want y to be a plus + + align:start position:0% +Then I I said well I want y to be a plus + + + align:start position:0% +Then I I said well I want y to be a plus +bx. So it should be here. But then I'm + + align:start position:0% +bx. So it should be here. But then I'm + + + align:start position:0% +bx. So it should be here. But then I'm +going to add some noise epsilon to go + + align:start position:0% +going to add some noise epsilon to go + + + align:start position:0% +going to add some noise epsilon to go +away again back from this line. + + align:start position:0% +away again back from this line. + + + align:start position:0% +away again back from this line. +And actually that's actually mean here. + + align:start position:0% +And actually that's actually mean here. + + + align:start position:0% +And actually that's actually mean here. +We actually got two points correct on + + align:start position:0% +We actually got two points correct on + + + align:start position:0% +We actually got two points correct on +this line. So there's basically two + + align:start position:0% +this line. So there's basically two + + + align:start position:0% +this line. So there's basically two +epsilons that were small enough that the + + align:start position:0% +epsilons that were small enough that the + + + align:start position:0% +epsilons that were small enough that the +dots actually look like they're on the + + align:start position:0% +dots actually look like they're on the + + + align:start position:0% +dots actually look like they're on the +line. Everybody's clear about what I'm + + align:start position:0% +line. Everybody's clear about what I'm + + + align:start position:0% +line. Everybody's clear about what I'm +drawing? So now, of course, if you're a + + align:start position:0% +drawing? So now, of course, if you're a + + + align:start position:0% +drawing? So now, of course, if you're a +statistician, you don't see this. You + + align:start position:0% +statistician, you don't see this. You + + + align:start position:0% +statistician, you don't see this. You +only see this. And you have to recover + + align:start position:0% +only see this. And you have to recover + + + align:start position:0% +only see this. And you have to recover +this guy. And it's going to look like + + align:start position:0% +this guy. And it's going to look like + + + align:start position:0% +this guy. And it's going to look like +this, right? You're going to have an + + align:start position:0% +this, right? You're going to have an + + + align:start position:0% +this, right? You're going to have an +estimated line, which is the red one, + + align:start position:0% +estimated line, which is the red one, + + + align:start position:0% +estimated line, which is the red one, +and the blue line, which is the uh uh uh + + align:start position:0% +and the blue line, which is the uh uh uh + + + align:start position:0% +and the blue line, which is the uh uh uh +the true one, the one that actually + + align:start position:0% +the true one, the one that actually + + + align:start position:0% +the true one, the one that actually +generated the data. And your question + + align:start position:0% +generated the data. And your question + + + align:start position:0% +generated the data. And your question +is, well, this line corresponds to some + + align:start position:0% +is, well, this line corresponds to some + + + align:start position:0% +is, well, this line corresponds to some +parameters a hat and b hat. How can I + + align:start position:0% +parameters a hat and b hat. How can I + + + align:start position:0% +parameters a hat and b hat. How can I +make sure that those two lines, how far + + align:start position:0% +make sure that those two lines, how far + + + align:start position:0% +make sure that those two lines, how far +those two lines are? And one way to + + align:start position:0% +those two lines are? And one way to + + + align:start position:0% +those two lines are? And one way to +address this question is to say how far + + align:start position:0% +address this question is to say how far + + + align:start position:0% +address this question is to say how far +is a from a hat and how far is b from b + + align:start position:0% +is a from a hat and how far is b from b + + + align:start position:0% +is a from a hat and how far is b from b +hat. Okay, another question of course + + align:start position:0% +hat. Okay, another question of course + + + align:start position:0% +hat. Okay, another question of course +that you ask is how do you find a hat + + align:start position:0% +that you ask is how do you find a hat + + + align:start position:0% +that you ask is how do you find a hat +and b hat? + + align:start position:0% +and b hat? + + + align:start position:0% +and b hat? +And as you can see it's basically the + + align:start position:0% +And as you can see it's basically the + + + align:start position:0% +And as you can see it's basically the +same thing. Remember what was a? So b + + align:start position:0% +same thing. Remember what was a? So b + + + align:start position:0% +same thing. Remember what was a? So b +was + + align:start position:0% +was + + + align:start position:0% +was +uh the coariance + + align:start position:0% +uh the coariance + + + align:start position:0% +uh the coariance +between x and y + + align:start position:0% +between x and y + + + align:start position:0% +between x and y +divided by the variance of x right we + + align:start position:0% +divided by the variance of x right we + + + align:start position:0% +divided by the variance of x right we +which I can rewrite as the expectation + + align:start position:0% +which I can rewrite as the expectation + + + align:start position:0% +which I can rewrite as the expectation +of xy minus expectation of x time + + align:start position:0% +of xy minus expectation of x time + + + align:start position:0% +of xy minus expectation of x time +expectation of y + + align:start position:0% +expectation of y + + + align:start position:0% +expectation of y +divided by expectation of x^2 + + align:start position:0% +divided by expectation of x^2 + + + align:start position:0% +divided by expectation of x^2 +minus expectation of x the whole thing + + align:start position:0% +minus expectation of x the whole thing + + + align:start position:0% +minus expectation of x the whole thing +square. Okay, + + align:start position:0% +square. Okay, + + + align:start position:0% +square. Okay, +if you look at the expression for B hat, + + align:start position:0% +if you look at the expression for B hat, + + + align:start position:0% +if you look at the expression for B hat, +I basically replaced all the + + align:start position:0% +I basically replaced all the + + + align:start position:0% +I basically replaced all the +expectations by bars, + + align:start position:0% +expectations by bars, + + + align:start position:0% +expectations by bars, +right? So I said, well, this guy I'm + + align:start position:0% +right? So I said, well, this guy I'm + + + align:start position:0% +right? So I said, well, this guy I'm +going to estimate by an average. + + align:start position:0% +going to estimate by an average. + + + align:start position:0% +going to estimate by an average. +So that's the so xy bar + + align:start position:0% +So that's the so xy bar + + + align:start position:0% +So that's the so xy bar +is 1 / n sum from i= 1 to n of x i * yi. + + align:start position:0% +is 1 / n sum from i= 1 to n of x i * yi. + + + align:start position:0% +is 1 / n sum from i= 1 to n of x i * yi. +XAR of course is just the one that we're + + align:start position:0% +XAR of course is just the one that we're + + + align:start position:0% +XAR of course is just the one that we're +used to. + + align:start position:0% + + + + align:start position:0% + +And same for Y bar. X squar bar, the one + + align:start position:0% +And same for Y bar. X squar bar, the one + + + align:start position:0% +And same for Y bar. X squar bar, the one +that's here, + + align:start position:0% + + + + align:start position:0% + +is the average of the squares. And XAR + + align:start position:0% +is the average of the squares. And XAR + + + align:start position:0% +is the average of the squares. And XAR +square is the square of the average. + + align:start position:0% + + + + align:start position:0% + +Okay, so you just basically replace + + align:start position:0% +Okay, so you just basically replace + + + align:start position:0% +Okay, so you just basically replace +this guy by Xbar, this guy by Y bar, + + align:start position:0% +this guy by Xbar, this guy by Y bar, + + + align:start position:0% +this guy by Xbar, this guy by Y bar, +this guy by X² bar, and this guy by Xar + + align:start position:0% +this guy by X² bar, and this guy by Xar + + + align:start position:0% +this guy by X² bar, and this guy by Xar +in the square. Okay, so that's basically + + align:start position:0% +in the square. Okay, so that's basically + + + align:start position:0% +in the square. Okay, so that's basically +one way to do it. Everywhere you see an + + align:start position:0% +one way to do it. Everywhere you see an + + + align:start position:0% +one way to do it. Everywhere you see an +expectation, you replace it by an + + align:start position:0% +expectation, you replace it by an + + + align:start position:0% +expectation, you replace it by an +average. That's the usual statistical + + align:start position:0% +average. That's the usual statistical + + + align:start position:0% +average. That's the usual statistical +hammer. You can actually be slightly + + align:start position:0% +hammer. You can actually be slightly + + + align:start position:0% +hammer. You can actually be slightly +more subtle about this. + + align:start position:0% + + + + align:start position:0% + +And as an exercise, I invite you to just + + align:start position:0% +And as an exercise, I invite you to just + + + align:start position:0% +And as an exercise, I invite you to just +to make sure that you know how to do + + align:start position:0% +to make sure that you know how to do + + + align:start position:0% +to make sure that you know how to do +this computation. It's going to be + + align:start position:0% +this computation. It's going to be + + + align:start position:0% +this computation. It's going to be +exactly the same kind of computations + + align:start position:0% +exactly the same kind of computations + + + align:start position:0% +exactly the same kind of computations +that we've done. But uh as an exercise, + + align:start position:0% +that we've done. But uh as an exercise, + + + align:start position:0% +that we've done. But uh as an exercise, +you can check that if you actually look + + align:start position:0% +you can check that if you actually look + + + align:start position:0% +you can check that if you actually look +at say well what I wanted to minimize + + align:start position:0% +at say well what I wanted to minimize + + + align:start position:0% +at say well what I wanted to minimize +here, I had an expectation, right? + + align:start position:0% + + + + align:start position:0% + +And I said, let's minimize this thing. + + align:start position:0% +And I said, let's minimize this thing. + + + align:start position:0% +And I said, let's minimize this thing. +Well, + + align:start position:0% + + + + align:start position:0% + +let's replace this by an average first + + align:start position:0% + + + + align:start position:0% + +and now minimize. + + align:start position:0% +and now minimize. + + + align:start position:0% +and now minimize. +Okay. So if I do this, it turns out I'm + + align:start position:0% +Okay. So if I do this, it turns out I'm + + + align:start position:0% +Okay. So if I do this, it turns out I'm +going to actually get the same result. + + align:start position:0% +going to actually get the same result. + + + align:start position:0% +going to actually get the same result. +The minimum of the average is basically + + align:start position:0% +The minimum of the average is basically + + + align:start position:0% +The minimum of the average is basically +this when I replace the average by the + + align:start position:0% +this when I replace the average by the + + + align:start position:0% +this when I replace the average by the +sorry when I replace the expectation by + + align:start position:0% +sorry when I replace the expectation by + + + align:start position:0% +sorry when I replace the expectation by +the average and then minimize it's the + + align:start position:0% +the average and then minimize it's the + + + align:start position:0% +the average and then minimize it's the +same thing as first minimizing and then + + align:start position:0% +same thing as first minimizing and then + + + align:start position:0% +same thing as first minimizing and then +replacing expectation by averages in + + align:start position:0% +replacing expectation by averages in + + + align:start position:0% +replacing expectation by averages in +this case. + + align:start position:0% +this case. + + + align:start position:0% +this case. +Again, this is a much more general + + align:start position:0% +Again, this is a much more general + + + align:start position:0% +Again, this is a much more general +principle because if you don't have a + + align:start position:0% +principle because if you don't have a + + + align:start position:0% +principle because if you don't have a +closed form for the minimum like for + + align:start position:0% +closed form for the minimum like for + + + align:start position:0% +closed form for the minimum like for +some say likelihood problems, well, you + + align:start position:0% +some say likelihood problems, well, you + + + align:start position:0% +some say likelihood problems, well, you +might not actually have a possibility to + + align:start position:0% +might not actually have a possibility to + + + align:start position:0% +might not actually have a possibility to +just look at what the formula looks + + align:start position:0% +just look at what the formula looks + + + align:start position:0% +just look at what the formula looks +like, see where the expectations show up + + align:start position:0% +like, see where the expectations show up + + + align:start position:0% +like, see where the expectations show up +and then just plug in the averages + + align:start position:0% +and then just plug in the averages + + + align:start position:0% +and then just plug in the averages +instead. So, you might this is the one + + align:start position:0% +instead. So, you might this is the one + + + align:start position:0% +instead. So, you might this is the one +you want to keep in mind. And again as + + align:start position:0% +you want to keep in mind. And again as + + + align:start position:0% +you want to keep in mind. And again as +an exercise. + + align:start position:0% + + + + align:start position:0% + +Okay. So here and then you do + + align:start position:0% +Okay. So here and then you do + + + align:start position:0% +Okay. So here and then you do +expectation replace by averages + + align:start position:0% + + + + align:start position:0% + +and then that's the same answer and I + + align:start position:0% +and then that's the same answer and I + + + align:start position:0% +and then that's the same answer and I +I encourage you to solve the exercise. + + align:start position:0% +I encourage you to solve the exercise. + + + align:start position:0% +I encourage you to solve the exercise. +Okay, everybody's clear that this is + + align:start position:0% +Okay, everybody's clear that this is + + + align:start position:0% +Okay, everybody's clear that this is +actually the same expression for a hat + + align:start position:0% +actually the same expression for a hat + + + align:start position:0% +actually the same expression for a hat +and b hat that we had before where we + + align:start position:0% +and b hat that we had before where we + + + align:start position:0% +and b hat that we had before where we +that we had for a and b when we replace + + align:start position:0% +that we had for a and b when we replace + + + align:start position:0% +that we had for a and b when we replace +the expectations by averages + + align:start position:0% +the expectations by averages + + + align:start position:0% +the expectations by averages +here. By the way, I minimize the sum + + align:start position:0% +here. By the way, I minimize the sum + + + align:start position:0% +here. By the way, I minimize the sum +rather than the average. It's clear to + + align:start position:0% +rather than the average. It's clear to + + + align:start position:0% +rather than the average. It's clear to +everyone that this is the same thing. + + align:start position:0% +everyone that this is the same thing. + + + align:start position:0% +everyone that this is the same thing. +Right? + + align:start position:0% + + + + align:start position:0% + +Yeah. + + align:start position:0% + + + + align:start position:0% + +So we did switch the derivative and the + + align:start position:0% +So we did switch the derivative and the + + + align:start position:0% +So we did switch the derivative and the +expectation + + align:start position:0% + + + + align:start position:0% + +before you came I think. + + align:start position:0% +before you came I think. + + + align:start position:0% +before you came I think. +Um all right so indeed the picture was + + align:start position:0% +Um all right so indeed the picture was + + + align:start position:0% +Um all right so indeed the picture was +the one that we said. So visually this + + align:start position:0% +the one that we said. So visually this + + + align:start position:0% +the one that we said. So visually this +is what we're doing. We're looking among + + align:start position:0% +is what we're doing. We're looking among + + + align:start position:0% +is what we're doing. We're looking among +all the lines. For each line, we compute + + align:start position:0% +all the lines. For each line, we compute + + + align:start position:0% +all the lines. For each line, we compute +this distance, right? So, if I gave you + + align:start position:0% +this distance, right? So, if I gave you + + + align:start position:0% +this distance, right? So, if I gave you +another line, there would be another set + + align:start position:0% +another line, there would be another set + + + align:start position:0% +another line, there would be another set +of arrows. You look at their length. You + + align:start position:0% +of arrows. You look at their length. You + + + align:start position:0% +of arrows. You look at their length. You +square it, and then you sum it all, and + + align:start position:0% +square it, and then you sum it all, and + + + align:start position:0% +square it, and then you sum it all, and +you find the line that has the minimum + + align:start position:0% +you find the line that has the minimum + + + align:start position:0% +you find the line that has the minimum +sum of squared length of the arrows. All + + align:start position:0% +sum of squared length of the arrows. All + + + align:start position:0% +sum of squared length of the arrows. All +right? And those are the arrows that + + align:start position:0% +right? And those are the arrows that + + + align:start position:0% +right? And those are the arrows that +we're looking at. But again, you could + + align:start position:0% +we're looking at. But again, you could + + + align:start position:0% +we're looking at. But again, you could +actually think of other distances and + + align:start position:0% +actually think of other distances and + + + align:start position:0% +actually think of other distances and +you would actually get different uh you + + align:start position:0% +you would actually get different uh you + + + align:start position:0% +you would actually get different uh you +could actually get different solutions, + + align:start position:0% +could actually get different solutions, + + + align:start position:0% +could actually get different solutions, +right? So there's something called mean + + align:start position:0% +right? So there's something called mean + + + align:start position:0% +right? So there's something called mean +absolute deviation which rather than + + align:start position:0% +absolute deviation which rather than + + + align:start position:0% +absolute deviation which rather than +minimizing this thing is actually + + align:start position:0% +minimizing this thing is actually + + + align:start position:0% +minimizing this thing is actually +minimizing the sum from i= 1 to n of the + + align:start position:0% +minimizing the sum from i= 1 to n of the + + + align:start position:0% +minimizing the sum from i= 1 to n of the +absolute value of y minus a + bx i + + align:start position:0% +absolute value of y minus a + bx i + + + align:start position:0% +absolute value of y minus a + bx i +and that will that's not something for + + align:start position:0% +and that will that's not something for + + + align:start position:0% +and that will that's not something for +which you're going to have a closed form + + align:start position:0% +which you're going to have a closed form + + + align:start position:0% +which you're going to have a closed form +as you can imagine uh you might have + + align:start position:0% +as you can imagine uh you might have + + + align:start position:0% +as you can imagine uh you might have +something that's sort of implicit uh but + + align:start position:0% +something that's sort of implicit uh but + + + align:start position:0% +something that's sort of implicit uh but +you can actually still solve it + + align:start position:0% +you can actually still solve it + + + align:start position:0% +you can actually still solve it +numerically and this is something that + + align:start position:0% +numerically and this is something that + + + align:start position:0% +numerically and this is something that +people also like to use but way way less + + align:start position:0% +people also like to use but way way less + + + align:start position:0% +people also like to use but way way less +than the le squares + + align:start position:0% + + + + align:start position:0% + +What did I just what? + + align:start position:0% + + + + align:start position:0% + +The sum of the absolute values of y i + + align:start position:0% +The sum of the absolute values of y i + + + align:start position:0% +The sum of the absolute values of y i +minus a plus bx i. + + align:start position:0% +minus a plus bx i. + + + align:start position:0% +minus a plus bx i. +So it's the same except that I don't + + align:start position:0% +So it's the same except that I don't + + + align:start position:0% +So it's the same except that I don't +have the square here. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% + + + + align:start position:0% + +So arguably, you know, predicting uh + + align:start position:0% +So arguably, you know, predicting uh + + + align:start position:0% +So arguably, you know, predicting uh +price uh a demand based on price is a + + align:start position:0% +price uh a demand based on price is a + + + align:start position:0% +price uh a demand based on price is a +fairly naive problem. Typically, what we + + align:start position:0% +fairly naive problem. Typically, what we + + + align:start position:0% +fairly naive problem. Typically, what we +have is a bunch of data that we've + + align:start position:0% +have is a bunch of data that we've + + + align:start position:0% +have is a bunch of data that we've +collected and we're hoping that together + + align:start position:0% +collected and we're hoping that together + + + align:start position:0% +collected and we're hoping that together +they can help us do a better prediction. + + align:start position:0% +they can help us do a better prediction. + + + align:start position:0% +they can help us do a better prediction. +All right, so maybe I don't have only + + align:start position:0% +All right, so maybe I don't have only + + + align:start position:0% +All right, so maybe I don't have only +the price, but uh maybe I have a bunch + + align:start position:0% +the price, but uh maybe I have a bunch + + + align:start position:0% +the price, but uh maybe I have a bunch +of other social uh indicators. Maybe I + + align:start position:0% +of other social uh indicators. Maybe I + + + align:start position:0% +of other social uh indicators. Maybe I +know the competi competition, the price + + align:start position:0% +know the competi competition, the price + + + align:start position:0% +know the competi competition, the price +of the competition. Maybe I know a bunch + + align:start position:0% +of the competition. Maybe I know a bunch + + + align:start position:0% +of the competition. Maybe I know a bunch +of other things that are actually + + align:start position:0% +of other things that are actually + + + align:start position:0% +of other things that are actually +relevant. And so I'm trying to find a + + align:start position:0% +relevant. And so I'm trying to find a + + + align:start position:0% +relevant. And so I'm trying to find a +way to combine a bunch of points, a + + align:start position:0% +way to combine a bunch of points, a + + + align:start position:0% +way to combine a bunch of points, a +bunch of measures. Let's say for + + align:start position:0% +bunch of measures. Let's say for + + + align:start position:0% +bunch of measures. Let's say for +example, there's a nice example that I + + align:start position:0% +example, there's a nice example that I + + + align:start position:0% +example, there's a nice example that I +like, which is uh uh people were trying + + align:start position:0% +like, which is uh uh people were trying + + + align:start position:0% +like, which is uh uh people were trying +to measure um something related to uh + + align:start position:0% +to measure um something related to uh + + + align:start position:0% +to measure um something related to uh +your body mass index. It's so basically + + align:start position:0% +your body mass index. It's so basically + + + align:start position:0% +your body mass index. It's so basically +the volume of your the density of your + + align:start position:0% +the volume of your the density of your + + + align:start position:0% +the volume of your the density of your +body and the way you can do this is by + + align:start position:0% +body and the way you can do this is by + + + align:start position:0% +body and the way you can do this is by +just you know really weighing someone + + align:start position:0% +just you know really weighing someone + + + align:start position:0% +just you know really weighing someone +and also putting them in some you know + + align:start position:0% +and also putting them in some you know + + + align:start position:0% +and also putting them in some you know +cubic meter of water and see how much + + align:start position:0% +cubic meter of water and see how much + + + align:start position:0% +cubic meter of water and see how much +overflows and then you have both the + + align:start position:0% +overflows and then you have both the + + + align:start position:0% +overflows and then you have both the +volume and the uh and um uh uh and the + + align:start position:0% +volume and the uh and um uh uh and the + + + align:start position:0% +volume and the uh and um uh uh and the +mass of this person and you can you know + + align:start position:0% +mass of this person and you can you know + + + align:start position:0% +mass of this person and you can you know +start computing density but uh as you + + align:start position:0% +start computing density but uh as you + + + align:start position:0% +start computing density but uh as you +can imagine you know I would not + + align:start position:0% +can imagine you know I would not + + + align:start position:0% +can imagine you know I would not +personally like to go to a gym where the + + align:start position:0% +personally like to go to a gym where the + + + align:start position:0% +personally like to go to a gym where the +first thing they ask is to just go in + + align:start position:0% +first thing they ask is to just go in + + + align:start position:0% +first thing they ask is to just go in +some uh uh bucket of water. And so + + align:start position:0% +some uh uh bucket of water. And so + + + align:start position:0% +some uh uh bucket of water. And so +people try to find ways to measure this + + align:start position:0% +people try to find ways to measure this + + + align:start position:0% +people try to find ways to measure this +based on other indicators that are much + + align:start position:0% +based on other indicators that are much + + + align:start position:0% +based on other indicators that are much +easier to measure. For example, I don't + + align:start position:0% +easier to measure. For example, I don't + + + align:start position:0% +easier to measure. For example, I don't +know, the length of my forearm and the + + align:start position:0% +know, the length of my forearm and the + + + align:start position:0% +know, the length of my forearm and the +circumference of my head and maybe from + + align:start position:0% +circumference of my head and maybe from + + + align:start position:0% +circumference of my head and maybe from +maybe my my belly would probably be more + + align:start position:0% +maybe my my belly would probably be more + + + align:start position:0% +maybe my my belly would probably be more +appropriate here. And so, you know, they + + align:start position:0% +appropriate here. And so, you know, they + + + align:start position:0% +appropriate here. And so, you know, they +just try to find something that actually + + align:start position:0% +just try to find something that actually + + + align:start position:0% +just try to find something that actually +makes sense. And so there's actually a + + align:start position:0% +makes sense. And so there's actually a + + + align:start position:0% +makes sense. And so there's actually a +nice example where you can show that if + + align:start position:0% +nice example where you can show that if + + + align:start position:0% +nice example where you can show that if +you measure I think one of the most + + align:start position:0% +you measure I think one of the most + + + align:start position:0% +you measure I think one of the most +significant was with the circumference + + align:start position:0% +significant was with the circumference + + + align:start position:0% +significant was with the circumference +of your wrist. This is actually a very + + align:start position:0% +of your wrist. This is actually a very + + + align:start position:0% +of your wrist. This is actually a very +good indicator of uh your uh your uh + + align:start position:0% +good indicator of uh your uh your uh + + + align:start position:0% +good indicator of uh your uh your uh +body density. And uh it turns out that + + align:start position:0% +body density. And uh it turns out that + + + align:start position:0% +body density. And uh it turns out that +um if you stuff all the bunch of things + + align:start position:0% +um if you stuff all the bunch of things + + + align:start position:0% +um if you stuff all the bunch of things +together, you might actually get a very + + align:start position:0% +together, you might actually get a very + + + align:start position:0% +together, you might actually get a very +good formula that explains things. All + + align:start position:0% +good formula that explains things. All + + + align:start position:0% +good formula that explains things. All +right. So what we're going to do is + + align:start position:0% +right. So what we're going to do is + + + align:start position:0% +right. So what we're going to do is +rather than saying we have only one x to + + align:start position:0% +rather than saying we have only one x to + + + align:start position:0% +rather than saying we have only one x to +explain y's, let's say we have 20 x's + + align:start position:0% +explain y's, let's say we have 20 x's + + + align:start position:0% +explain y's, let's say we have 20 x's +that we're trying to combine to explain + + align:start position:0% +that we're trying to combine to explain + + + align:start position:0% +that we're trying to combine to explain +why. And again, just like assuming + + align:start position:0% +why. And again, just like assuming + + + align:start position:0% +why. And again, just like assuming +something of the form y is a plus b * x + + align:start position:0% +something of the form y is a plus b * x + + + align:start position:0% +something of the form y is a plus b * x +was the simplest thing we could do here. + + align:start position:0% +was the simplest thing we could do here. + + + align:start position:0% +was the simplest thing we could do here. +We're just going to assume that we have + + align:start position:0% +We're just going to assume that we have + + + align:start position:0% +We're just going to assume that we have +y is a + b1 x1 plus b2 x2 plus b3 x3. + + align:start position:0% +y is a + b1 x1 plus b2 x2 plus b3 x3. + + + align:start position:0% +y is a + b1 x1 plus b2 x2 plus b3 x3. +And we can write it in a vector form by + + align:start position:0% +And we can write it in a vector form by + + + align:start position:0% +And we can write it in a vector form by +writing that yi is x i transpose b which + + align:start position:0% +writing that yi is x i transpose b which + + + align:start position:0% +writing that yi is x i transpose b which +is now a vector plus epsilon i. Okay. + + align:start position:0% +is now a vector plus epsilon i. Okay. + + + align:start position:0% +is now a vector plus epsilon i. Okay. +And here on the board I'm going to have + + align:start position:0% +And here on the board I'm going to have + + + align:start position:0% +And here on the board I'm going to have +a right hard time doing boldface but all + + align:start position:0% +a right hard time doing boldface but all + + + align:start position:0% +a right hard time doing boldface but all +these things are vectors right except + + align:start position:0% +these things are vectors right except + + + align:start position:0% +these things are vectors right except +for y + + align:start position:0% +for y + + + align:start position:0% +for y +which is a number right? Yi is a number. + + align:start position:0% +which is a number right? Yi is a number. + + + align:start position:0% +which is a number right? Yi is a number. +it's always the value of my y-axis. + + align:start position:0% +it's always the value of my y-axis. + + + align:start position:0% +it's always the value of my y-axis. +Okay? So even if my x-axis lives on this + + align:start position:0% +Okay? So even if my x-axis lives on this + + + align:start position:0% +Okay? So even if my x-axis lives on this +is x1 and this is x2, y is really just + + align:start position:0% +is x1 and this is x2, y is really just + + + align:start position:0% +is x1 and this is x2, y is really just +the real valued function. And so I'm + + align:start position:0% +the real valued function. And so I'm + + + align:start position:0% +the real valued function. And so I'm +going to get a bunch of points x1 y1 and + + align:start position:0% +going to get a bunch of points x1 y1 and + + + align:start position:0% +going to get a bunch of points x1 y1 and +I'm going to see how much they respond. + + align:start position:0% +I'm going to see how much they respond. + + + align:start position:0% +I'm going to see how much they respond. +Right? So for example, it's the my body + + align:start position:0% +Right? So for example, it's the my body + + + align:start position:0% +Right? So for example, it's the my body +density is y and then all the x's are a + + align:start position:0% +density is y and then all the x's are a + + + align:start position:0% +density is y and then all the x's are a +bunch of other things. Agreed with that? + + align:start position:0% +bunch of other things. Agreed with that? + + + align:start position:0% +bunch of other things. Agreed with that? +So this is an equation that holds on the + + align:start position:0% +So this is an equation that holds on the + + + align:start position:0% +So this is an equation that holds on the +real line. But this guy here is in R + + align:start position:0% +real line. But this guy here is in R + + + align:start position:0% +real line. But this guy here is in R +P + + align:start position:0% +P + + + align:start position:0% +P +and this guy is in RP. + + align:start position:0% +and this guy is in RP. + + + align:start position:0% +and this guy is in RP. +It's actually common to talk to to call + + align:start position:0% +It's actually common to talk to to call + + + align:start position:0% +It's actually common to talk to to call +B beta when it's a vector and that's the + + align:start position:0% +B beta when it's a vector and that's the + + + align:start position:0% +B beta when it's a vector and that's the +usual + + align:start position:0% +usual + + + align:start position:0% +usual +that's the usual linear regression + + align:start position:0% +that's the usual linear regression + + + align:start position:0% +that's the usual linear regression +notation. Y is X beta plus epsilon. + + align:start position:0% +notation. Y is X beta plus epsilon. + + + align:start position:0% +notation. Y is X beta plus epsilon. +So X's are called explanatory variables. + + align:start position:0% +So X's are called explanatory variables. + + + align:start position:0% +So X's are called explanatory variables. +Y is called explain variable or + + align:start position:0% +Y is called explain variable or + + + align:start position:0% +Y is called explain variable or +dependent variable + + align:start position:0% +dependent variable + + + align:start position:0% +dependent variable +uh or response variable. It has a bunch + + align:start position:0% +uh or response variable. It has a bunch + + + align:start position:0% +uh or response variable. It has a bunch +of names. You can use whatever you think + + align:start position:0% +of names. You can use whatever you think + + + align:start position:0% +of names. You can use whatever you think +feel more comfortable with. They should + + align:start position:0% +feel more comfortable with. They should + + + align:start position:0% +feel more comfortable with. They should +it should actually be explicit, right? + + align:start position:0% +it should actually be explicit, right? + + + align:start position:0% +it should actually be explicit, right? +So that's all you care about. Um + + align:start position:0% +So that's all you care about. Um + + + align:start position:0% +So that's all you care about. Um +now + + align:start position:0% +now + + + align:start position:0% +now +what we typically do is that rather so + + align:start position:0% +what we typically do is that rather so + + + align:start position:0% +what we typically do is that rather so +you notice here that there's actually no + + align:start position:0% +you notice here that there's actually no + + + align:start position:0% +you notice here that there's actually no +intercept. If I actually fold that back + + align:start position:0% +intercept. If I actually fold that back + + + align:start position:0% +intercept. If I actually fold that back +down to one dimension, there's actually + + align:start position:0% +down to one dimension, there's actually + + + align:start position:0% +down to one dimension, there's actually +a is equal to zero. Right? If I go back + + align:start position:0% +a is equal to zero. Right? If I go back + + + align:start position:0% +a is equal to zero. Right? If I go back +to P is equal to 1, + + align:start position:0% +to P is equal to 1, + + + align:start position:0% +to P is equal to 1, +that would imply that yi is well say + + align:start position:0% +that would imply that yi is well say + + + align:start position:0% +that would imply that yi is well say +beta * x plus epsilon i. And that's not + + align:start position:0% +beta * x plus epsilon i. And that's not + + + align:start position:0% +beta * x plus epsilon i. And that's not +good. I want to have an intercept. And + + align:start position:0% +good. I want to have an intercept. And + + + align:start position:0% +good. I want to have an intercept. And +the way I do this rather than writing a + + align:start position:0% +the way I do this rather than writing a + + + align:start position:0% +the way I do this rather than writing a +plus this and you know just have like a + + align:start position:0% +plus this and you know just have like a + + + align:start position:0% +plus this and you know just have like a +an overload of notation. What I'm + + align:start position:0% +an overload of notation. What I'm + + + align:start position:0% +an overload of notation. What I'm +actually doing is that I fold back I + + align:start position:0% +actually doing is that I fold back I + + + align:start position:0% +actually doing is that I fold back I +fold my intercept back into my x. + + align:start position:0% +fold my intercept back into my x. + + + align:start position:0% +fold my intercept back into my x. +And so if I measure 20 variables, I'm + + align:start position:0% +And so if I measure 20 variables, I'm + + + align:start position:0% +And so if I measure 20 variables, I'm +going to create a 21st variable which is + + align:start position:0% +going to create a 21st variable which is + + + align:start position:0% +going to create a 21st variable which is +always equal to one. Okay? So you should + + align:start position:0% +always equal to one. Okay? So you should + + + align:start position:0% +always equal to one. Okay? So you should +need to think of x as being one and then + + align:start position:0% +need to think of x as being one and then + + + align:start position:0% +need to think of x as being one and then +x1 + + align:start position:0% +x1 + + + align:start position:0% +x1 +x p and now sorry xp minus one I guess. + + align:start position:0% +x p and now sorry xp minus one I guess. + + + align:start position:0% +x p and now sorry xp minus one I guess. +Okay. And now this is in RP. + + align:start position:0% +Okay. And now this is in RP. + + + align:start position:0% +Okay. And now this is in RP. +Okay. So the we I'm always going to + + align:start position:0% +Okay. So the we I'm always going to + + + align:start position:0% +Okay. So the we I'm always going to +assume that the first one is one. I can + + align:start position:0% +assume that the first one is one. I can + + + align:start position:0% +assume that the first one is one. I can +always do that. If I have a table of + + align:start position:0% +always do that. If I have a table of + + + align:start position:0% +always do that. If I have a table of +data, if my data is given to me in an + + align:start position:0% +data, if my data is given to me in an + + + align:start position:0% +data, if my data is given to me in an +Excel spreadsheet + + align:start position:0% +Excel spreadsheet + + + align:start position:0% +Excel spreadsheet +and here I have the density that I + + align:start position:0% +and here I have the density that I + + + align:start position:0% +and here I have the density that I +measured on my data and then maybe here + + align:start position:0% +measured on my data and then maybe here + + + align:start position:0% +measured on my data and then maybe here +I have the height and here I have the + + align:start position:0% +I have the height and here I have the + + + align:start position:0% +I have the height and here I have the +wrists circumference. And I have all + + align:start position:0% +wrists circumference. And I have all + + + align:start position:0% +wrists circumference. And I have all +these things. All I have to do is to + + align:start position:0% +these things. All I have to do is to + + + align:start position:0% +these things. All I have to do is to +create another column here of ones. I + + align:start position:0% +create another column here of ones. I + + + align:start position:0% +create another column here of ones. I +just put one, one, one, one, one, one. + + align:start position:0% +just put one, one, one, one, one, one. + + + align:start position:0% +just put one, one, one, one, one, one. +Okay, that's all I have to do to create + + align:start position:0% +Okay, that's all I have to do to create + + + align:start position:0% +Okay, that's all I have to do to create +this guy. Agreed? + + align:start position:0% +this guy. Agreed? + + + align:start position:0% +this guy. Agreed? +And now my x is going to be just one of + + align:start position:0% +And now my x is going to be just one of + + + align:start position:0% +And now my x is going to be just one of +those rows. + + align:start position:0% +those rows. + + + align:start position:0% +those rows. +Okay, so that's this is x i this entire + + align:start position:0% +Okay, so that's this is x i this entire + + + align:start position:0% +Okay, so that's this is x i this entire +row and this entry here is yi. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% + + + + align:start position:0% + +So now for my noise coefficients, I'm + + align:start position:0% +So now for my noise coefficients, I'm + + + align:start position:0% +So now for my noise coefficients, I'm +still going to assume ask for the same + + align:start position:0% +still going to assume ask for the same + + + align:start position:0% +still going to assume ask for the same +thing except that here the covariance is + + align:start position:0% +thing except that here the covariance is + + + align:start position:0% +thing except that here the covariance is +not between X between one random + + align:start position:0% +not between X between one random + + + align:start position:0% +not between X between one random +variable and and another random variable + + align:start position:0% +variable and and another random variable + + + align:start position:0% +variable and and another random variable +is between a random vector and a random + + align:start position:0% +is between a random vector and a random + + + align:start position:0% +is between a random vector and a random +variable. + + align:start position:0% +variable. + + + align:start position:0% +variable. +Okay, how do I measure the coariance + + align:start position:0% +Okay, how do I measure the coariance + + + align:start position:0% +Okay, how do I measure the coariance +between a vector and a random variable? + + align:start position:0% + + + + align:start position:0% + +Yeah. So basically well okay uh + + align:start position:0% + + + + align:start position:0% + +yeah so yeah I mean you know coance + + align:start position:0% +yeah so yeah I mean you know coance + + + align:start position:0% +yeah so yeah I mean you know coance +vector is equal to zero is the same + + align:start position:0% +vector is equal to zero is the same + + + align:start position:0% +vector is equal to zero is the same +thing as it norm equal to zero but yeah + + align:start position:0% +thing as it norm equal to zero but yeah + + + align:start position:0% +thing as it norm equal to zero but yeah +this is basically thought of entry-wise + + align:start position:0% +this is basically thought of entry-wise + + + align:start position:0% +this is basically thought of entry-wise +for each coordinate of x I want that the + + align:start position:0% +for each coordinate of x I want that the + + + align:start position:0% +for each coordinate of x I want that the +coariance between epsilon and this co + + align:start position:0% +coariance between epsilon and this co + + + align:start position:0% +coariance between epsilon and this co +this coordinate of x is equal to zero so + + align:start position:0% +this coordinate of x is equal to zero so + + + align:start position:0% +this coordinate of x is equal to zero so +I'm just asking this for all coordinates + + align:start position:0% +I'm just asking this for all coordinates + + + align:start position:0% +I'm just asking this for all coordinates +again in most instances we're going to + + align:start position:0% +again in most instances we're going to + + + align:start position:0% +again in most instances we're going to +think that epsilon is independent of x + + align:start position:0% +think that epsilon is independent of x + + + align:start position:0% +think that epsilon is independent of x +and that's something we can understand + + align:start position:0% +and that's something we can understand + + + align:start position:0% +and that's something we can understand +without thinking about coordinates. + + align:start position:0% +without thinking about coordinates. + + + align:start position:0% +without thinking about coordinates. +All right. So, yeah. + + align:start position:0% + + + + align:start position:0% + +I'm sorry. Can you repeat the question? + + align:start position:0% +I'm sorry. Can you repeat the question? + + + align:start position:0% +I'm sorry. Can you repeat the question? +I didn't hear. + + align:start position:0% +I didn't hear. + + + align:start position:0% +I didn't hear. +Yeah, beta is the parameter we're + + align:start position:0% +Yeah, beta is the parameter we're + + + align:start position:0% +Yeah, beta is the parameter we're +looking for, right? Just like it was a + + align:start position:0% +looking for, right? Just like it was a + + + align:start position:0% +looking for, right? Just like it was a +and the pair above the whole vector beta + + align:start position:0% +and the pair above the whole vector beta + + + align:start position:0% +and the pair above the whole vector beta +now. + + align:start position:0% + + + + align:start position:0% + +So there's no well you can you think of + + align:start position:0% +So there's no well you can you think of + + + align:start position:0% +So there's no well you can you think of +an intercept of a function that takes I + + align:start position:0% +an intercept of a function that takes I + + + align:start position:0% +an intercept of a function that takes I +mean there is there is one actually + + align:start position:0% +mean there is there is one actually + + + align:start position:0% +mean there is there is one actually +that's the one for which betas all the + + align:start position:0% +that's the one for which betas all the + + + align:start position:0% +that's the one for which betas all the +betas that don't correspond to the + + align:start position:0% +betas that don't correspond to the + + + align:start position:0% +betas that don't correspond to the +vector of all ones. So the intercept is + + align:start position:0% +vector of all ones. So the intercept is + + + align:start position:0% +vector of all ones. So the intercept is +really the the weight that I put on this + + align:start position:0% +really the the weight that I put on this + + + align:start position:0% +really the the weight that I put on this +guy. That's the beta that's going to + + align:start position:0% +guy. That's the beta that's going to + + + align:start position:0% +guy. That's the beta that's going to +come to this guy. But we don't really + + align:start position:0% +come to this guy. But we don't really + + + align:start position:0% +come to this guy. But we don't really +talk about intercept in two dimensions. + + align:start position:0% +talk about intercept in two dimensions. + + + align:start position:0% +talk about intercept in two dimensions. +If sorry if x lives in two dimensions. + + align:start position:0% +If sorry if x lives in two dimensions. + + + align:start position:0% +If sorry if x lives in two dimensions. +Uh the way you want to think about this + + align:start position:0% +Uh the way you want to think about this + + + align:start position:0% +Uh the way you want to think about this +is uh you take a sheet of paper like + + align:start position:0% +is uh you take a sheet of paper like + + + align:start position:0% +is uh you take a sheet of paper like +that. Right? So I have now I have points + + align:start position:0% +that. Right? So I have now I have points + + + align:start position:0% +that. Right? So I have now I have points +that live in three dimensions. Right? So + + align:start position:0% +that live in three dimensions. Right? So + + + align:start position:0% +that live in three dimensions. Right? So +let's say one direction here is x1. This + + align:start position:0% +let's say one direction here is x1. This + + + align:start position:0% +let's say one direction here is x1. This +direction is x2 and this direction is y. + + align:start position:0% +direction is x2 and this direction is y. + + + align:start position:0% +direction is x2 and this direction is y. +Okay. And so what's going to happen is + + align:start position:0% +Okay. And so what's going to happen is + + + align:start position:0% +Okay. And so what's going to happen is +that I'm going to have like my points + + align:start position:0% +that I'm going to have like my points + + + align:start position:0% +that I'm going to have like my points +that live in this threedimensional + + align:start position:0% +that live in this threedimensional + + + align:start position:0% +that live in this threedimensional +space. And what I'm trying to do when + + align:start position:0% +space. And what I'm trying to do when + + + align:start position:0% +space. And what I'm trying to do when +I'm trying to do a linear model for + + align:start position:0% +I'm trying to do a linear model for + + + align:start position:0% +I'm trying to do a linear model for +those guys when I assume a linear model, + + align:start position:0% +those guys when I assume a linear model, + + + align:start position:0% +those guys when I assume a linear model, +what I assume is that there's a plane in + + align:start position:0% +what I assume is that there's a plane in + + + align:start position:0% +what I assume is that there's a plane in +those three dimensions. So think of this + + align:start position:0% +those three dimensions. So think of this + + + align:start position:0% +those three dimensions. So think of this +guy as being going everywhere and + + align:start position:0% +guy as being going everywhere and + + + align:start position:0% +guy as being going everywhere and +there's a plane al close to which all my + + align:start position:0% +there's a plane al close to which all my + + + align:start position:0% +there's a plane al close to which all my +points should be. Right? That's what's + + align:start position:0% +points should be. Right? That's what's + + + align:start position:0% +points should be. Right? That's what's +happening in two dimensions. If you see + + align:start position:0% +happening in two dimensions. If you see + + + align:start position:0% +happening in two dimensions. If you see +higher dimensions, then congratulations + + align:start position:0% +higher dimensions, then congratulations + + + align:start position:0% +higher dimensions, then congratulations +to you. But uh I can't. All right? So um + + align:start position:0% +to you. But uh I can't. All right? So um + + + align:start position:0% +to you. But uh I can't. All right? So um +uh but you know you can definitely + + align:start position:0% +uh but you know you can definitely + + + align:start position:0% +uh but you know you can definitely +formalize that fairly easily + + align:start position:0% +formalize that fairly easily + + + align:start position:0% +formalize that fairly easily +mathematically and just talk about + + align:start position:0% +mathematically and just talk about + + + align:start position:0% +mathematically and just talk about +vectors right + + align:start position:0% +vectors right + + + align:start position:0% +vectors right +so now here if I talk about the le + + align:start position:0% +so now here if I talk about the le + + + align:start position:0% +so now here if I talk about the le +squared error estimator or just the le + + align:start position:0% +squared error estimator or just the le + + + align:start position:0% +squared error estimator or just the le +squares estimator of beta it's simply + + align:start position:0% +squares estimator of beta it's simply + + + align:start position:0% +squares estimator of beta it's simply +the same thing as before just like we + + align:start position:0% +the same thing as before just like we + + + align:start position:0% +the same thing as before just like we +said + + align:start position:0% +said + + + align:start position:0% +said +so remember you should think of b as + + align:start position:0% +so remember you should think of b as + + + align:start position:0% +so remember you should think of b as +being as beta as being both the pair ab + + align:start position:0% +being as beta as being both the pair ab + + + align:start position:0% +being as beta as being both the pair ab +generalized okay so we said, "Oh, we + + align:start position:0% +generalized okay so we said, "Oh, we + + + align:start position:0% +generalized okay so we said, "Oh, we +wanted to minimize the expectation of y + + align:start position:0% +wanted to minimize the expectation of y + + + align:start position:0% +wanted to minimize the expectation of y +minus + + align:start position:0% +minus + + + align:start position:0% +minus +a + b x^ + + align:start position:0% + + + + align:start position:0% + +squar right now. So that's in for p is + + align:start position:0% +squar right now. So that's in for p is + + + align:start position:0% +squar right now. So that's in for p is +equal to 1. Now for p larger than or + + align:start position:0% +equal to 1. Now for p larger than or + + + align:start position:0% +equal to 1. Now for p larger than or +equal to two, we're just going to write + + align:start position:0% +equal to two, we're just going to write + + + align:start position:0% +equal to two, we're just going to write +it as y - x transpose + + align:start position:0% +it as y - x transpose + + + align:start position:0% +it as y - x transpose +beta + + align:start position:0% +beta + + + align:start position:0% +beta +squared + + align:start position:0% +squared + + + align:start position:0% +squared +Uh + + align:start position:0% +Uh + + + align:start position:0% +Uh +okay. So I'm just trying to minimize + + align:start position:0% +okay. So I'm just trying to minimize + + + align:start position:0% +okay. So I'm just trying to minimize +this quantity. Of course I don't have + + align:start position:0% +this quantity. Of course I don't have + + + align:start position:0% +this quantity. Of course I don't have +access to this. So what I'm going to do + + align:start position:0% +access to this. So what I'm going to do + + + align:start position:0% +access to this. So what I'm going to do +is I'm going to replace my expectation + + align:start position:0% +is I'm going to replace my expectation + + + align:start position:0% +is I'm going to replace my expectation +by an average. + + align:start position:0% +by an average. + + + align:start position:0% +by an average. +[Applause] + + align:start position:0% + + + + align:start position:0% + +So here I'm using the notation t because + + align:start position:0% +So here I'm using the notation t because + + + align:start position:0% +So here I'm using the notation t because +beta is the true one and I don't want to + + align:start position:0% +beta is the true one and I don't want to + + + align:start position:0% +beta is the true one and I don't want to +to just so here I have a variable t + + align:start position:0% +to just so here I have a variable t + + + align:start position:0% +to just so here I have a variable t +that's just moving around and so now I'm + + align:start position:0% +that's just moving around and so now I'm + + + align:start position:0% +that's just moving around and so now I'm +going to take the square of this thing + + align:start position:0% +going to take the square of this thing + + + align:start position:0% +going to take the square of this thing +and when I minimize this overall t in + + align:start position:0% +and when I minimize this overall t in + + + align:start position:0% +and when I minimize this overall t in +our p the arg min the minimum is + + align:start position:0% +our p the arg min the minimum is + + + align:start position:0% +our p the arg min the minimum is +attained + + align:start position:0% + + + + align:start position:0% + +at beta hat which is my estimator. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% + + + + align:start position:0% + +So if I want to actually compute Yeah. + + align:start position:0% + + + + align:start position:0% + +Uh you mean the previous slide? + + align:start position:0% +Uh you mean the previous slide? + + + align:start position:0% +Uh you mean the previous slide? +So again I'm just defining an estimator + + align:start position:0% +So again I'm just defining an estimator + + + align:start position:0% +So again I'm just defining an estimator +just like I would tell you just take the + + align:start position:0% +just like I would tell you just take the + + + align:start position:0% +just like I would tell you just take the +estimator that has coordinates four + + align:start position:0% +estimator that has coordinates four + + + align:start position:0% +estimator that has coordinates four +everywhere. + + align:start position:0% + + + + align:start position:0% + +Yeah. So + + align:start position:0% + + + + align:start position:0% + +um so + + align:start position:0% +um so + + + align:start position:0% +um so +um + + align:start position:0% + + + + align:start position:0% + +yes. So the answer is yes. I'm I I was + + align:start position:0% +yes. So the answer is yes. I'm I I was + + + align:start position:0% +yes. So the answer is yes. I'm I I was +just trying to think if this was + + align:start position:0% +just trying to think if this was + + + align:start position:0% +just trying to think if this was +captured. So it is not captured in this + + align:start position:0% +captured. So it is not captured in this + + + align:start position:0% +captured. So it is not captured in this +guy because this is just telling me that + + align:start position:0% +guy because this is just telling me that + + + align:start position:0% +guy because this is just telling me that +the expectation of + + align:start position:0% +the expectation of + + + align:start position:0% +the expectation of +epsilon i minus expectation of epsilon i + + align:start position:0% +epsilon i minus expectation of epsilon i + + + align:start position:0% +epsilon i minus expectation of epsilon i +is equal to zero. Okay. Yeah. So yes I + + align:start position:0% +is equal to zero. Okay. Yeah. So yes I + + + align:start position:0% +is equal to zero. Okay. Yeah. So yes I +need to have that epsilon i has mean + + align:start position:0% +need to have that epsilon i has mean + + + align:start position:0% +need to have that epsilon i has mean +zero for let's assume that expectation + + align:start position:0% +zero for let's assume that expectation + + + align:start position:0% +zero for let's assume that expectation +of epsilon i is zero for this problem. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +Um, + + align:start position:0% + + + + align:start position:0% + +and we also need we're going to need + + align:start position:0% +and we also need we're going to need + + + align:start position:0% +and we also need we're going to need +something about some sort of question + + align:start position:0% +something about some sort of question + + + align:start position:0% +something about some sort of question +about the variance being not equal to + + align:start position:0% +about the variance being not equal to + + + align:start position:0% +about the variance being not equal to +zero, right? But this is going to come + + align:start position:0% +zero, right? But this is going to come + + + align:start position:0% +zero, right? But this is going to come +up later. So let's think for one second + + align:start position:0% +up later. So let's think for one second + + + align:start position:0% +up later. So let's think for one second +about doing the same approach as we did + + align:start position:0% +about doing the same approach as we did + + + align:start position:0% +about doing the same approach as we did +before. Take the partial derivative with + + align:start position:0% +before. Take the partial derivative with + + + align:start position:0% +before. Take the partial derivative with +respect to the first coordinate of t + + align:start position:0% +respect to the first coordinate of t + + + align:start position:0% +respect to the first coordinate of t +with respect to the second coordinate of + + align:start position:0% +with respect to the second coordinate of + + + align:start position:0% +with respect to the second coordinate of +t with respect to the third coordinate + + align:start position:0% +t with respect to the third coordinate + + + align:start position:0% +t with respect to the third coordinate +of t, etc. So that's what we did before. + + align:start position:0% +of t, etc. So that's what we did before. + + + align:start position:0% +of t, etc. So that's what we did before. +We had two equations and we reconciled + + align:start position:0% +We had two equations and we reconciled + + + align:start position:0% +We had two equations and we reconciled +them because it was fairly easy to + + align:start position:0% +them because it was fairly easy to + + + align:start position:0% +them because it was fairly easy to +solve, right? + + align:start position:0% +solve, right? + + + align:start position:0% +solve, right? +But in general, what's going to happen + + align:start position:0% +But in general, what's going to happen + + + align:start position:0% +But in general, what's going to happen +is we're going to have a system of + + align:start position:0% +is we're going to have a system of + + + align:start position:0% +is we're going to have a system of +equations. We're going to have a system + + align:start position:0% +equations. We're going to have a system + + + align:start position:0% +equations. We're going to have a system +of P equations, one for each of the + + align:start position:0% +of P equations, one for each of the + + + align:start position:0% +of P equations, one for each of the +coordinates of T. And we're going to + + align:start position:0% +coordinates of T. And we're going to + + + align:start position:0% +coordinates of T. And we're going to +have P uh unknowns each coordinate of T. + + align:start position:0% +have P uh unknowns each coordinate of T. + + + align:start position:0% +have P uh unknowns each coordinate of T. +And so we're going to have the system to + + align:start position:0% +And so we're going to have the system to + + + align:start position:0% +And so we're going to have the system to +solve. Actually, turns out it's going to + + align:start position:0% +solve. Actually, turns out it's going to + + + align:start position:0% +solve. Actually, turns out it's going to +be a linear system, but it's not going + + align:start position:0% +be a linear system, but it's not going + + + align:start position:0% +be a linear system, but it's not going +to be something that we're going to be + + align:start position:0% +to be something that we're going to be + + + align:start position:0% +to be something that we're going to be +able to solve coordinate by coordinate. + + align:start position:0% +able to solve coordinate by coordinate. + + + align:start position:0% +able to solve coordinate by coordinate. +It's going to be annoying to solve. You + + align:start position:0% +It's going to be annoying to solve. You + + + align:start position:0% +It's going to be annoying to solve. You +know, you can guess that what's going to + + align:start position:0% +know, you can guess that what's going to + + + align:start position:0% +know, you can guess that what's going to +happen, right? We here it involved the + + align:start position:0% +happen, right? We here it involved the + + + align:start position:0% +happen, right? We here it involved the +coariance between X and epsilon right + + align:start position:0% +coariance between X and epsilon right + + + align:start position:0% +coariance between X and epsilon right +that's what it involved to understand um + + align:start position:0% +that's what it involved to understand um + + + align:start position:0% +that's what it involved to understand um +sorry the coordinate the the correlation + + align:start position:0% +sorry the coordinate the the correlation + + + align:start position:0% +sorry the coordinate the the correlation +between X and Y to understand how this + + align:start position:0% +between X and Y to understand how this + + + align:start position:0% +between X and Y to understand how this +the solution of this problem was in this + + align:start position:0% +the solution of this problem was in this + + + align:start position:0% +the solution of this problem was in this +case there's going to be not only the + + align:start position:0% +case there's going to be not only the + + + align:start position:0% +case there's going to be not only the +correlation sorry the coariance between + + align:start position:0% +correlation sorry the coariance between + + + align:start position:0% +correlation sorry the coariance between +X1 and Y X2 and Y X3 etc all the way to + + align:start position:0% +X1 and Y X2 and Y X3 etc all the way to + + + align:start position:0% +X1 and Y X2 and Y X3 etc all the way to +XP and Y but there's also going to be + + align:start position:0% +XP and Y but there's also going to be + + + align:start position:0% +XP and Y but there's also going to be +all the cross coariances between XJ and + + align:start position:0% +all the cross coariances between XJ and + + + align:start position:0% +all the cross coariances between XJ and +X K and so this is going to be a + + align:start position:0% +X K and so this is going to be a + + + align:start position:0% +X K and so this is going to be a +nightmare to solve + + align:start position:0% +nightmare to solve + + + align:start position:0% +nightmare to solve +like in this system and what we do is + + align:start position:0% +like in this system and what we do is + + + align:start position:0% +like in this system and what we do is +that we go on to using a matrix notation + + align:start position:0% +that we go on to using a matrix notation + + + align:start position:0% +that we go on to using a matrix notation +so that when we take derivatives we take + + align:start position:0% +so that when we take derivatives we take + + + align:start position:0% +so that when we take derivatives we take +derivative we we talk about gradients + + align:start position:0% +derivative we we talk about gradients + + + align:start position:0% +derivative we we talk about gradients +and then we can invert matrices and + + align:start position:0% +and then we can invert matrices and + + + align:start position:0% +and then we can invert matrices and +solve linear systems in a somewhat + + align:start position:0% +solve linear systems in a somewhat + + + align:start position:0% +solve linear systems in a somewhat +formal manner by just saying that if I + + align:start position:0% +formal manner by just saying that if I + + + align:start position:0% +formal manner by just saying that if I +want to solve the system ax= + + align:start position:0% +want to solve the system ax= + + + align:start position:0% +want to solve the system ax= +b rather than actually solving this for + + align:start position:0% +b rather than actually solving this for + + + align:start position:0% +b rather than actually solving this for +each coordinate of x individually I just + + align:start position:0% +each coordinate of x individually I just + + + align:start position:0% +each coordinate of x individually I just +say that x is equal to a inverse time b + + align:start position:0% +say that x is equal to a inverse time b + + + align:start position:0% +say that x is equal to a inverse time b +right so that's really what why we're + + align:start position:0% +right so that's really what why we're + + + align:start position:0% +right so that's really what why we're +going to the the equation one because we + + align:start position:0% +going to the the equation one because we + + + align:start position:0% +going to the the equation one because we +have a formalism to write the that X is + + align:start position:0% +have a formalism to write the that X is + + + align:start position:0% +have a formalism to write the that X is +the solution of this system. I'm not + + align:start position:0% +the solution of this system. I'm not + + + align:start position:0% +the solution of this system. I'm not +telling you that this is going to be + + align:start position:0% +telling you that this is going to be + + + align:start position:0% +telling you that this is going to be +easy to solve numerically, but at least + + align:start position:0% +easy to solve numerically, but at least + + + align:start position:0% +easy to solve numerically, but at least +I can write it. Okay? And so here's how + + align:start position:0% +I can write it. Okay? And so here's how + + + align:start position:0% +I can write it. Okay? And so here's how +it goes. I have a bunch of vectors. + + align:start position:0% +it goes. I have a bunch of vectors. + + + align:start position:0% +it goes. I have a bunch of vectors. +I have So what are my vectors? Right? So + + align:start position:0% +I have So what are my vectors? Right? So + + + align:start position:0% +I have So what are my vectors? Right? So +I have X1. Oh, by the way, I didn't + + align:start position:0% +I have X1. Oh, by the way, I didn't + + + align:start position:0% +I have X1. Oh, by the way, I didn't +actually mention that when I put the + + align:start position:0% +actually mention that when I put the + + + align:start position:0% +actually mention that when I put the +lowercase, when I put the subscript, I'm + + align:start position:0% +lowercase, when I put the subscript, I'm + + + align:start position:0% +lowercase, when I put the subscript, I'm +talking about the observation. And when + + align:start position:0% +talking about the observation. And when + + + align:start position:0% +talking about the observation. And when +I put the superscript, I'm talking about + + align:start position:0% +I put the superscript, I'm talking about + + + align:start position:0% +I put the superscript, I'm talking about +the coordinates, right? So I have x1 + + align:start position:0% +the coordinates, right? So I have x1 + + + align:start position:0% +the coordinates, right? So I have x1 +which is equal to one x x11 + + align:start position:0% +which is equal to one x x11 + + + align:start position:0% +which is equal to one x x11 +x uh one p + + align:start position:0% +x uh one p + + + align:start position:0% +x uh one p +x2 which is one x21 + + align:start position:0% +x2 which is one x21 + + + align:start position:0% +x2 which is one x21 +x2 p + + align:start position:0% +x2 p + + + align:start position:0% +x2 p +all the way to xn which is one + + align:start position:0% +all the way to xn which is one + + + align:start position:0% +all the way to xn which is one +x n1 + + align:start position:0% +x n1 + + + align:start position:0% +x n1 +xnp. All right. Right? So those are my n + + align:start position:0% +xnp. All right. Right? So those are my n + + + align:start position:0% +xnp. All right. Right? So those are my n +observed x's and then I have another y1 + + align:start position:0% +observed x's and then I have another y1 + + + align:start position:0% +observed x's and then I have another y1 +y2 yn that comes paired with those guys. + + align:start position:0% +y2 yn that comes paired with those guys. + + + align:start position:0% +y2 yn that comes paired with those guys. +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +So the first thing is that I'm going to + + align:start position:0% +So the first thing is that I'm going to + + + align:start position:0% +So the first thing is that I'm going to +stack those guys into some vector that + + align:start position:0% +stack those guys into some vector that + + + align:start position:0% +stack those guys into some vector that +I'm going to call y. So maybe I should + + align:start position:0% +I'm going to call y. So maybe I should + + + align:start position:0% +I'm going to call y. So maybe I should +put an arrow for the purpose of the + + align:start position:0% +put an arrow for the purpose of the + + + align:start position:0% +put an arrow for the purpose of the +blackboard and it's just y1 to yn. Okay. + + align:start position:0% +blackboard and it's just y1 to yn. Okay. + + + align:start position:0% +blackboard and it's just y1 to yn. Okay. +So this is a vector in rn. + + align:start position:0% +So this is a vector in rn. + + + align:start position:0% +So this is a vector in rn. +Now, if I want to stack those guys + + align:start position:0% +Now, if I want to stack those guys + + + align:start position:0% +Now, if I want to stack those guys +together, I can either create a long + + align:start position:0% +together, I can either create a long + + + align:start position:0% +together, I can either create a long +vector of size n times p, but the + + align:start position:0% +vector of size n times p, but the + + + align:start position:0% +vector of size n times p, but the +problem is that I lose the role of who's + + align:start position:0% +problem is that I lose the role of who's + + + align:start position:0% +problem is that I lose the role of who's +a coordinate and who's uh who's an + + align:start position:0% +a coordinate and who's uh who's an + + + align:start position:0% +a coordinate and who's uh who's an +observation. And so, it's actually nicer + + align:start position:0% +observation. And so, it's actually nicer + + + align:start position:0% +observation. And so, it's actually nicer +for me to just put those guys next to + + align:start position:0% +for me to just put those guys next to + + + align:start position:0% +for me to just put those guys next to +each other and create one new uh + + align:start position:0% +each other and create one new uh + + + align:start position:0% +each other and create one new uh +variable. And so, the way I'm going to + + align:start position:0% +variable. And so, the way I'm going to + + + align:start position:0% +variable. And so, the way I'm going to +do this is rather than actually stacking + + align:start position:0% +do this is rather than actually stacking + + + align:start position:0% +do this is rather than actually stacking +those guys like that, I'm going to take + + align:start position:0% +those guys like that, I'm going to take + + + align:start position:0% +those guys like that, I'm going to take +their transpose and stack them as rows + + align:start position:0% +their transpose and stack them as rows + + + align:start position:0% +their transpose and stack them as rows +of a matrix. Okay? So I'm going to + + align:start position:0% +of a matrix. Okay? So I'm going to + + + align:start position:0% +of a matrix. Okay? So I'm going to +create a matrix which here is denoted + + align:start position:0% +create a matrix which here is denoted + + + align:start position:0% +create a matrix which here is denoted +typically by I'm going to write x + + align:start position:0% +typically by I'm going to write x + + + align:start position:0% +typically by I'm going to write x +doubleb bar + + align:start position:0% +doubleb bar + + + align:start position:0% +doubleb bar +and here I'm going to actually just so + + align:start position:0% +and here I'm going to actually just so + + + align:start position:0% +and here I'm going to actually just so +since I'm taking those guys like this + + align:start position:0% +since I'm taking those guys like this + + + align:start position:0% +since I'm taking those guys like this +the first column is going to be only + + align:start position:0% +the first column is going to be only + + + align:start position:0% +the first column is going to be only +ones + + align:start position:0% + + + + align:start position:0% + +and then I'm going to have uh well x11 + + align:start position:0% +and then I'm going to have uh well x11 + + + align:start position:0% +and then I'm going to have uh well x11 +x1 p and here I'm going to have x n1 + + align:start position:0% +x1 p and here I'm going to have x n1 + + + align:start position:0% +x1 p and here I'm going to have x n1 +x np + + align:start position:0% +x np + + + align:start position:0% +x np +okay so here The number of rows is n and + + align:start position:0% +okay so here The number of rows is n and + + + align:start position:0% +okay so here The number of rows is n and +the number of columns is p. One row per + + align:start position:0% +the number of columns is p. One row per + + + align:start position:0% +the number of columns is p. One row per +observation, one column per coordinate. + + align:start position:0% + + + + align:start position:0% + +And again, I uh make your life + + align:start position:0% +And again, I uh make your life + + + align:start position:0% +And again, I uh make your life +miserable. Uh because this really should + + align:start position:0% +miserable. Uh because this really should + + + align:start position:0% +miserable. Uh because this really should +be p minus one because I already used + + align:start position:0% +be p minus one because I already used + + + align:start position:0% +be p minus one because I already used +the first one for this guy. I'm sorry + + align:start position:0% +the first one for this guy. I'm sorry + + + align:start position:0% +the first one for this guy. I'm sorry +about that. It's a bit painful. Uh so + + align:start position:0% +about that. It's a bit painful. Uh so + + + align:start position:0% +about that. It's a bit painful. Uh so +usually we don't even write what's in + + align:start position:0% +usually we don't even write what's in + + + align:start position:0% +usually we don't even write what's in +there so we don't have to think about + + align:start position:0% +there so we don't have to think about + + + align:start position:0% +there so we don't have to think about +it. Those are just vectors of size p. + + align:start position:0% +it. Those are just vectors of size p. + + + align:start position:0% +it. Those are just vectors of size p. +Okay, so now that I create this thing, I + + align:start position:0% +Okay, so now that I create this thing, I + + + align:start position:0% +Okay, so now that I create this thing, I +can actually just basically stack up all + + align:start position:0% +can actually just basically stack up all + + + align:start position:0% +can actually just basically stack up all +my models. So y i equals x i transpose + + align:start position:0% +my models. So y i equals x i transpose + + + align:start position:0% +my models. So y i equals x i transpose +beta plus epsilon i for all i = 1 to n. + + align:start position:0% +beta plus epsilon i for all i = 1 to n. + + + align:start position:0% +beta plus epsilon i for all i = 1 to n. +This transforms into this is equivalent + + align:start position:0% +This transforms into this is equivalent + + + align:start position:0% +This transforms into this is equivalent +to saying that the vector Y is equal to + + align:start position:0% +to saying that the vector Y is equal to + + + align:start position:0% +to saying that the vector Y is equal to +the matrix X time beta plus a matrix + + align:start position:0% +the matrix X time beta plus a matrix + + + align:start position:0% +the matrix X time beta plus a matrix +plus a vector epsilon where epsilon is + + align:start position:0% +plus a vector epsilon where epsilon is + + + align:start position:0% +plus a vector epsilon where epsilon is +just epsilon 1 to epsilon N. + + align:start position:0% +just epsilon 1 to epsilon N. + + + align:start position:0% +just epsilon 1 to epsilon N. +Right? So I have just this system which + + align:start position:0% +Right? So I have just this system which + + + align:start position:0% +Right? So I have just this system which +I write as a matrix which really just + + align:start position:0% +I write as a matrix which really just + + + align:start position:0% +I write as a matrix which really just +consists in stacking up all these + + align:start position:0% +consists in stacking up all these + + + align:start position:0% +consists in stacking up all these +equations next to each other. + + align:start position:0% + + + + align:start position:0% + +All right. + + align:start position:0% +All right. + + + align:start position:0% +All right. +So now that I have this model, this is + + align:start position:0% +So now that I have this model, this is + + + align:start position:0% +So now that I have this model, this is +the usual le squares model. And here + + align:start position:0% +the usual le squares model. And here + + + align:start position:0% +the usual le squares model. And here +when I want to write my le squares + + align:start position:0% +when I want to write my le squares + + + align:start position:0% +when I want to write my le squares +criterion in terms of matrices, right? + + align:start position:0% +criterion in terms of matrices, right? + + + align:start position:0% +criterion in terms of matrices, right? +My le squares criterion remember was sum + + align:start position:0% +My le squares criterion remember was sum + + + align:start position:0% +My le squares criterion remember was sum +from i= 1 to n of yi minus x i transpose + + align:start position:0% +from i= 1 to n of yi minus x i transpose + + + align:start position:0% +from i= 1 to n of yi minus x i transpose +beta squared. Well, here it's really + + align:start position:0% +beta squared. Well, here it's really + + + align:start position:0% +beta squared. Well, here it's really +just the sum of the square of the + + align:start position:0% +just the sum of the square of the + + + align:start position:0% +just the sum of the square of the +coefficients of the of the vector y - x + + align:start position:0% +coefficients of the of the vector y - x + + + align:start position:0% +coefficients of the of the vector y - x +beta. So this is actually equal to the + + align:start position:0% +beta. So this is actually equal to the + + + align:start position:0% +beta. So this is actually equal to the +norm squar of y - x beta^ 2. + + align:start position:0% + + + + align:start position:0% + +That's just the square norm is by + + align:start position:0% +That's just the square norm is by + + + align:start position:0% +That's just the square norm is by +definition the sum of the square of the + + align:start position:0% +definition the sum of the square of the + + + align:start position:0% +definition the sum of the square of the +coordinates. + + align:start position:0% +coordinates. + + + align:start position:0% +coordinates. +And so now I can actually talk about + + align:start position:0% +And so now I can actually talk about + + + align:start position:0% +And so now I can actually talk about +minimizing a norm squared. And here it's + + align:start position:0% +minimizing a norm squared. And here it's + + + align:start position:0% +minimizing a norm squared. And here it's +going to be easier for me to take + + align:start position:0% +going to be easier for me to take + + + align:start position:0% +going to be easier for me to take +derivatives. All right. So we'll do that + + align:start position:0% +derivatives. All right. So we'll do that + + + align:start position:0% +derivatives. All right. So we'll do that +uh next time. \ No newline at end of file diff --git a/zD6tTb74KdU.txt b/zD6tTb74KdU.txt new file mode 100644 index 0000000000000000000000000000000000000000..2c810910c6fadc32ca7afc1a421baeb94af6bfea --- /dev/null +++ b/zD6tTb74KdU.txt @@ -0,0 +1,739 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT OpenCourseWare continue to + + align:start position:0% +will help MIT OpenCourseWare continue to + + + align:start position:0% +will help MIT OpenCourseWare continue to +offer high quality educational resources + + align:start position:0% +offer high quality educational resources + + + align:start position:0% +offer high quality educational resources +for free + + align:start position:0% +for free + + + align:start position:0% +for free +to make a donation or view additional + + align:start position:0% +to make a donation or view additional + + + align:start position:0% +to make a donation or view additional +materials from hundreds of MIT courses + + align:start position:0% +materials from hundreds of MIT courses + + + align:start position:0% +materials from hundreds of MIT courses +visit MIT opencourseware at ocw.mit.edu + + align:start position:0% +visit MIT opencourseware at ocw.mit.edu + + + align:start position:0% +visit MIT opencourseware at ocw.mit.edu +in a previous demonstration on two beam + + align:start position:0% +in a previous demonstration on two beam + + + align:start position:0% +in a previous demonstration on two beam +interference we saw that the fringe + + align:start position:0% +interference we saw that the fringe + + + align:start position:0% +interference we saw that the fringe +pattern was a series of vertical lines + + align:start position:0% +pattern was a series of vertical lines + + + align:start position:0% +pattern was a series of vertical lines +the reason was that two the two beams + + align:start position:0% +the reason was that two the two beams + + + align:start position:0% +the reason was that two the two beams +were plane waves and the lines were due + + align:start position:0% +were plane waves and the lines were due + + + align:start position:0% +were plane waves and the lines were due +to the interference of two plane waves + + align:start position:0% +to the interference of two plane waves + + + align:start position:0% +to the interference of two plane waves +with a slight angle between them in this + + align:start position:0% +with a slight angle between them in this + + + align:start position:0% +with a slight angle between them in this +demonstration we're going to show that + + align:start position:0% +demonstration we're going to show that + + + align:start position:0% +demonstration we're going to show that +you can get all kinds of shapes in the + + align:start position:0% +you can get all kinds of shapes in the + + + align:start position:0% +you can get all kinds of shapes in the +fringe pattern by simply placing a lens + + align:start position:0% +fringe pattern by simply placing a lens + + + align:start position:0% +fringe pattern by simply placing a lens +in the setup and here is the setup as + + align:start position:0% +in the setup and here is the setup as + + + align:start position:0% +in the setup and here is the setup as +you may recall here's the laser is the + + align:start position:0% +you may recall here's the laser is the + + + align:start position:0% +you may recall here's the laser is the +beam from the laser being reflected by + + align:start position:0% +beam from the laser being reflected by + + + align:start position:0% +beam from the laser being reflected by +this mirror and here we're going to add + + align:start position:0% +this mirror and here we're going to add + + + align:start position:0% +this mirror and here we're going to add +a lens the light coming out of the lens + + align:start position:0% +a lens the light coming out of the lens + + + align:start position:0% +a lens the light coming out of the lens +and reflected by this mirror here will + + align:start position:0% +and reflected by this mirror here will + + + align:start position:0% +and reflected by this mirror here will +have some curvature now and when it + + align:start position:0% +have some curvature now and when it + + + align:start position:0% +have some curvature now and when it +enters the Michelson interferometer here + + align:start position:0% +enters the Michelson interferometer here + + + align:start position:0% +enters the Michelson interferometer here +the the beam going to this arm being the + + align:start position:0% +the the beam going to this arm being the + + + align:start position:0% +the the beam going to this arm being the +longer arm slightly longer arm will have + + align:start position:0% +longer arm slightly longer arm will have + + + align:start position:0% +longer arm slightly longer arm will have +slightly different curvature when it + + align:start position:0% +slightly different curvature when it + + + align:start position:0% +slightly different curvature when it +interferes with the beam coming from + + align:start position:0% +interferes with the beam coming from + + + align:start position:0% +interferes with the beam coming from +this arm because the path length here is + + align:start position:0% +this arm because the path length here is + + + align:start position:0% +this arm because the path length here is +shorter than this one the two beams will + + align:start position:0% +shorter than this one the two beams will + + + align:start position:0% +shorter than this one the two beams will +interfere and pass along this direction + + align:start position:0% +interfere and pass along this direction + + + align:start position:0% +interfere and pass along this direction +then then they will get reflected at + + align:start position:0% +then then they will get reflected at + + + align:start position:0% +then then they will get reflected at +this mirror through the lens and then + + align:start position:0% +this mirror through the lens and then + + + align:start position:0% +this mirror through the lens and then +onto the screen so now if we take a + + align:start position:0% +onto the screen so now if we take a + + + align:start position:0% +onto the screen so now if we take a +close-up at the at the fringe pattern we + + align:start position:0% +close-up at the at the fringe pattern we + + + align:start position:0% +close-up at the at the fringe pattern we +will see that we have circular fringes + + align:start position:0% +will see that we have circular fringes + + + align:start position:0% +will see that we have circular fringes +and what's interesting about the + + align:start position:0% +and what's interesting about the + + + align:start position:0% +and what's interesting about the +circular fringes is that the spacing + + align:start position:0% +circular fringes is that the spacing + + + align:start position:0% +circular fringes is that the spacing +between the fringes can be changed by + + align:start position:0% +between the fringes can be changed by + + + align:start position:0% +between the fringes can be changed by +disturbing the setup for example if I + + align:start position:0% +disturbing the setup for example if I + + + align:start position:0% +disturbing the setup for example if I +change the length of of the of this arm + + align:start position:0% +change the length of of the of this arm + + + align:start position:0% +change the length of of the of this arm +here I can change the spacing between + + align:start position:0% +here I can change the spacing between + + + align:start position:0% +here I can change the spacing between +which + + align:start position:0% +which + + + align:start position:0% +which +the fringes because I'm getting closer + + align:start position:0% +the fringes because I'm getting closer + + + align:start position:0% +the fringes because I'm getting closer +and closer to the same curvature as in + + align:start position:0% +and closer to the same curvature as in + + + align:start position:0% +and closer to the same curvature as in +the as in the other arm if I go further + + align:start position:0% +the as in the other arm if I go further + + + align:start position:0% +the as in the other arm if I go further +again we can see that I can increase the + + align:start position:0% +again we can see that I can increase the + + + align:start position:0% +again we can see that I can increase the +number of fringes showing that again the + + align:start position:0% +number of fringes showing that again the + + + align:start position:0% +number of fringes showing that again the +curvature has changed relative to this + + align:start position:0% +curvature has changed relative to this + + + align:start position:0% +curvature has changed relative to this +fixed arm over here now I'm going to + + align:start position:0% +fixed arm over here now I'm going to + + + align:start position:0% +fixed arm over here now I'm going to +show the effect of misalignment on the + + align:start position:0% +show the effect of misalignment on the + + + align:start position:0% +show the effect of misalignment on the +on the circular fringes if I adjust this + + align:start position:0% +on the circular fringes if I adjust this + + + align:start position:0% +on the circular fringes if I adjust this +mirror to here and then let's again look + + align:start position:0% +mirror to here and then let's again look + + + align:start position:0% +mirror to here and then let's again look +at the fringes and then you can see that + + align:start position:0% +at the fringes and then you can see that + + + align:start position:0% +at the fringes and then you can see that +by mr. lining this mirror I can get arcs + + align:start position:0% +by mr. lining this mirror I can get arcs + + + align:start position:0% +by mr. lining this mirror I can get arcs +instead of instead of the bull's eye and + + align:start position:0% +instead of instead of the bull's eye and + + + align:start position:0% +instead of instead of the bull's eye and +in fact if I'm if I look closely at the + + align:start position:0% +in fact if I'm if I look closely at the + + + align:start position:0% +in fact if I'm if I look closely at the +arcs I can tell which way the beams are + + align:start position:0% +arcs I can tell which way the beams are + + + align:start position:0% +arcs I can tell which way the beams are +are misaligned + + align:start position:0% + + + + align:start position:0% + +alright now what I'll try and do is to + + align:start position:0% +alright now what I'll try and do is to + + + align:start position:0% +alright now what I'll try and do is to +try and make the field go all dark or + + align:start position:0% +try and make the field go all dark or + + + align:start position:0% +try and make the field go all dark or +alright by making the two paths as + + align:start position:0% +alright by making the two paths as + + + align:start position:0% +alright by making the two paths as +identical as possible now you can see I + + align:start position:0% +identical as possible now you can see I + + + align:start position:0% +identical as possible now you can see I +only have about a couple of fringes an + + align:start position:0% +only have about a couple of fringes an + + + align:start position:0% +only have about a couple of fringes an +interference pattern they slightly + + align:start position:0% +interference pattern they slightly + + + align:start position:0% +interference pattern they slightly +misaligned and now I have them look a + + align:start position:0% +misaligned and now I have them look a + + + align:start position:0% +misaligned and now I have them look a +little bit better centered so now let me + + align:start position:0% +little bit better centered so now let me + + + align:start position:0% +little bit better centered so now let me +close in one path and then see if I can + + align:start position:0% +close in one path and then see if I can + + + align:start position:0% +close in one path and then see if I can +get complete darkness or complete + + align:start position:0% +get complete darkness or complete + + + align:start position:0% +get complete darkness or complete +brightness let me just the alignment as + + align:start position:0% +brightness let me just the alignment as + + + align:start position:0% +brightness let me just the alignment as +I move in + + align:start position:0% + + + + align:start position:0% + +here you can see I'm getting close to + + align:start position:0% +here you can see I'm getting close to + + + align:start position:0% +here you can see I'm getting close to +equal path a little bit more + + align:start position:0% + + + + align:start position:0% + +not quite + + align:start position:0% + + + + align:start position:0% + +that's almost we're almost we're almost + + align:start position:0% +that's almost we're almost we're almost + + + align:start position:0% +that's almost we're almost we're almost +there you can see if I press on the + + align:start position:0% +there you can see if I press on the + + + align:start position:0% +there you can see if I press on the +table and see screen going bright and + + align:start position:0% +table and see screen going bright and + + + align:start position:0% +table and see screen going bright and +dark and I think I have a little bit to + + align:start position:0% +dark and I think I have a little bit to + + + align:start position:0% +dark and I think I have a little bit to +go and maybe we can get complete + + align:start position:0% + + + + align:start position:0% + +extinction + + align:start position:0% + + + + align:start position:0% + +let's see this is + + align:start position:0% + + + + align:start position:0% + +see pre is pretty pretty close to + + align:start position:0% +see pre is pretty pretty close to + + + align:start position:0% +see pre is pretty pretty close to +complete + + align:start position:0% + + + + align:start position:0% + +a complete extinction so in this brief + + align:start position:0% +a complete extinction so in this brief + + + align:start position:0% +a complete extinction so in this brief +demonstration then we've shown that you + + align:start position:0% +demonstration then we've shown that you + + + align:start position:0% +demonstration then we've shown that you +can get circular fringes bullseye arcs + + align:start position:0% +can get circular fringes bullseye arcs + + + align:start position:0% +can get circular fringes bullseye arcs +and what-have-you by simply making the + + align:start position:0% +and what-have-you by simply making the + + + align:start position:0% +and what-have-you by simply making the +input beam to the interferometer have + + align:start position:0% +input beam to the interferometer have + + + align:start position:0% +input beam to the interferometer have +some curvature and by adjusting the path + + align:start position:0% +some curvature and by adjusting the path + + + align:start position:0% +some curvature and by adjusting the path +length difference between the two arms + + align:start position:0% +length difference between the two arms + + + align:start position:0% +length difference between the two arms +you can get a variety of free systems \ No newline at end of file diff --git a/zZfr7Zqfqm4.txt b/zZfr7Zqfqm4.txt new file mode 100644 index 0000000000000000000000000000000000000000..f5f5c141afa5c633ebf5339d4907034b3c50dfe7 --- /dev/null +++ b/zZfr7Zqfqm4.txt @@ -0,0 +1,1195 @@ +align:start position:0% + +instead of building all of our logic + + align:start position:0% +instead of building all of our logic + + + align:start position:0% +instead of building all of our logic +functions directly in CMOS it is easier + + align:start position:0% +functions directly in CMOS it is easier + + + align:start position:0% +functions directly in CMOS it is easier +for us to create a higher level of + + align:start position:0% +for us to create a higher level of + + + align:start position:0% +for us to create a higher level of +abstraction known as boolean gates which + + align:start position:0% +abstraction known as boolean gates which + + + align:start position:0% +abstraction known as boolean gates which +represent CMOS gates each gate is + + align:start position:0% +represent CMOS gates each gate is + + + align:start position:0% +represent CMOS gates each gate is +assigned a symbol which can then be used + + align:start position:0% +assigned a symbol which can then be used + + + align:start position:0% +assigned a symbol which can then be used +in schematic diagrams that combine + + align:start position:0% +in schematic diagrams that combine + + + align:start position:0% +in schematic diagrams that combine +multiple logic gates together in order + + align:start position:0% +multiple logic gates together in order + + + align:start position:0% +multiple logic gates together in order +to be able to understand what function + + align:start position:0% +to be able to understand what function + + + align:start position:0% +to be able to understand what function +any combination of logic gates will + + align:start position:0% +any combination of logic gates will + + + align:start position:0% +any combination of logic gates will +produce we will begin by reviewing the + + align:start position:0% +produce we will begin by reviewing the + + + align:start position:0% +produce we will begin by reviewing the +basic gates together with the truth + + align:start position:0% +basic gates together with the truth + + + align:start position:0% +basic gates together with the truth +tables that define their logic we begin + + align:start position:0% +tables that define their logic we begin + + + align:start position:0% +tables that define their logic we begin +with an inverter an inverter is a gate + + align:start position:0% +with an inverter an inverter is a gate + + + align:start position:0% +with an inverter an inverter is a gate +that has a single input and a single + + align:start position:0% +that has a single input and a single + + + align:start position:0% +that has a single input and a single +output the output is simply the inverse + + align:start position:0% +output the output is simply the inverse + + + align:start position:0% +output the output is simply the inverse +of the input when a equals 0 y equals 1 + + align:start position:0% +of the input when a equals 0 y equals 1 + + + align:start position:0% +of the input when a equals 0 y equals 1 +and when a equals 1 y equals 0 next we + + align:start position:0% +and when a equals 1 y equals 0 next we + + + align:start position:0% +and when a equals 1 y equals 0 next we +examine and and or gates the and + + align:start position:0% +examine and and or gates the and + + + align:start position:0% +examine and and or gates the and +function expects all of its inputs to be + + align:start position:0% +function expects all of its inputs to be + + + align:start position:0% +function expects all of its inputs to be +true or 1 in order to produce a 1 as its + + align:start position:0% +true or 1 in order to produce a 1 as its + + + align:start position:0% +true or 1 in order to produce a 1 as its +output so its truth table is for a B + + align:start position:0% +output so its truth table is for a B + + + align:start position:0% +output so its truth table is for a B +equals 0 0 y equals 0 for a B equals 0 1 + + align:start position:0% +equals 0 0 y equals 0 for a B equals 0 1 + + + align:start position:0% +equals 0 0 y equals 0 for a B equals 0 1 +y equals 0 for a B equals 1 0 y equals 0 + + align:start position:0% +y equals 0 for a B equals 1 0 y equals 0 + + + align:start position:0% +y equals 0 for a B equals 1 0 y equals 0 +and for a B equal 1 1 y equals 1 the or + + align:start position:0% +and for a B equal 1 1 y equals 1 the or + + + align:start position:0% +and for a B equal 1 1 y equals 1 the or +function just expects at least one of + + align:start position:0% +function just expects at least one of + + + align:start position:0% +function just expects at least one of +its inputs to be true in order to + + align:start position:0% +its inputs to be true in order to + + + align:start position:0% +its inputs to be true in order to +produce a 1 as its output so for a b + + align:start position:0% +produce a 1 as its output so for a b + + + align:start position:0% +produce a 1 as its output so for a b +equals 0 0 y equals 0 but for the other + + align:start position:0% +equals 0 0 y equals 0 but for the other + + + align:start position:0% +equals 0 0 y equals 0 but for the other +3 combinations y equals 1 NAND and nor + + align:start position:0% +3 combinations y equals 1 NAND and nor + + + align:start position:0% +3 combinations y equals 1 NAND and nor +gates simply produce the inverse of and + + align:start position:0% +gates simply produce the inverse of and + + + align:start position:0% +gates simply produce the inverse of and +and or the reason that we like to work + + align:start position:0% +and or the reason that we like to work + + + align:start position:0% +and or the reason that we like to work +with nand and nor gates is because they + + align:start position:0% +with nand and nor gates is because they + + + align:start position:0% +with nand and nor gates is because they +are inverting gates and they can be + + align:start position:0% +are inverting gates and they can be + + + align:start position:0% +are inverting gates and they can be +implemented as a single CMOS gate + + align:start position:0% +implemented as a single CMOS gate + + + align:start position:0% +implemented as a single CMOS gate +whereas the and and or gates cannot + + align:start position:0% +whereas the and and or gates cannot + + + align:start position:0% +whereas the and and or gates cannot +finally the last basic gate is an + + align:start position:0% +finally the last basic gate is an + + + align:start position:0% +finally the last basic gate is an +exclusive or the exclusive or produces a + + align:start position:0% +exclusive or the exclusive or produces a + + + align:start position:0% +exclusive or the exclusive or produces a +1 output if exactly one of its two + + align:start position:0% +1 output if exactly one of its two + + + align:start position:0% +1 output if exactly one of its two +inputs is a 1 and 0 otherwise so for a B + + align:start position:0% +inputs is a 1 and 0 otherwise so for a B + + + align:start position:0% +inputs is a 1 and 0 otherwise so for a B +equals 0 0 y equals 0 for a B equals 0 1 + + align:start position:0% +equals 0 0 y equals 0 for a B equals 0 1 + + + align:start position:0% +equals 0 0 y equals 0 for a B equals 0 1 +y equals 1 + + align:start position:0% +y equals 1 + + + align:start position:0% +y equals 1 +a B equal to 1 0 y equals 1 and for a be + + align:start position:0% +a B equal to 1 0 y equals 1 and for a be + + + align:start position:0% +a B equal to 1 0 y equals 1 and for a be +equals to 1 1 y equals 0 + + align:start position:0% +equals to 1 1 y equals 0 + + + align:start position:0% +equals to 1 1 y equals 0 +the output of 1 bullion gate can be used + + align:start position:0% +the output of 1 bullion gate can be used + + + align:start position:0% +the output of 1 bullion gate can be used +as an input to another bullion gate so + + align:start position:0% +as an input to another bullion gate so + + + align:start position:0% +as an input to another bullion gate so +multiple gates can be used to generate + + align:start position:0% +multiple gates can be used to generate + + + align:start position:0% +multiple gates can be used to generate +more complex functions for example here + + align:start position:0% +more complex functions for example here + + + align:start position:0% +more complex functions for example here +we have a circuit that consists of 2 + + align:start position:0% +we have a circuit that consists of 2 + + + align:start position:0% +we have a circuit that consists of 2 +inputs and 6 gates which are an inverter + + align:start position:0% +inputs and 6 gates which are an inverter + + + align:start position:0% +inputs and 6 gates which are an inverter +and and gate and or gate 2 nor gates and + + align:start position:0% +and and gate and or gate 2 nor gates and + + + align:start position:0% +and and gate and or gate 2 nor gates and +one NAND gate in order to figure out + + align:start position:0% +one NAND gate in order to figure out + + + align:start position:0% +one NAND gate in order to figure out +what this combination of gates produces + + align:start position:0% +what this combination of gates produces + + + align:start position:0% +what this combination of gates produces +as its output we can work incrementally + + align:start position:0% +as its output we can work incrementally + + + align:start position:0% +as its output we can work incrementally +through the circuit we begin by + + align:start position:0% +through the circuit we begin by + + + align:start position:0% +through the circuit we begin by +enumerated of inputs for a and B we know + + align:start position:0% +enumerated of inputs for a and B we know + + + align:start position:0% +enumerated of inputs for a and B we know +that the output of the inverter is the + + align:start position:0% +that the output of the inverter is the + + + align:start position:0% +that the output of the inverter is the +complement of B the and and or gates use + + align:start position:0% +complement of B the and and or gates use + + + align:start position:0% +complement of B the and and or gates use +the a and B inputs directly so since we + + align:start position:0% +the a and B inputs directly so since we + + + align:start position:0% +the a and B inputs directly so since we +just reviewed what and and or gates + + align:start position:0% +just reviewed what and and or gates + + + align:start position:0% +just reviewed what and and or gates +produce we can fill in these columns as + + align:start position:0% +produce we can fill in these columns as + + + align:start position:0% +produce we can fill in these columns as +well next we want to see what our first + + align:start position:0% +well next we want to see what our first + + + align:start position:0% +well next we want to see what our first +nor gate produces its inputs are a and + + align:start position:0% +nor gate produces its inputs are a and + + + align:start position:0% +nor gate produces its inputs are a and +the complement of B we walk through each + + align:start position:0% +the complement of B we walk through each + + + align:start position:0% +the complement of B we walk through each +of the input combinations and determine + + align:start position:0% +of the input combinations and determine + + + align:start position:0% +of the input combinations and determine +the corresponding output for that gate + + align:start position:0% +the corresponding output for that gate + + + align:start position:0% +the corresponding output for that gate +for input 0 1 the output is 0 for 0 0 + + align:start position:0% +for input 0 1 the output is 0 for 0 0 + + + align:start position:0% +for input 0 1 the output is 0 for 0 0 +the output is 1 for inputs 1 1 the + + align:start position:0% +the output is 1 for inputs 1 1 the + + + align:start position:0% +the output is 1 for inputs 1 1 the +output is 0 and for input 1 0 the output + + align:start position:0% +output is 0 and for input 1 0 the output + + + align:start position:0% +output is 0 and for input 1 0 the output +is 0 in the same manner we evaluate the + + align:start position:0% +is 0 in the same manner we evaluate the + + + align:start position:0% +is 0 in the same manner we evaluate the +outputs for our second nor gate its + + align:start position:0% +outputs for our second nor gate its + + + align:start position:0% +outputs for our second nor gate its +inputs are the outputs of the first nor + + align:start position:0% +inputs are the outputs of the first nor + + + align:start position:0% +inputs are the outputs of the first nor +gate and the and gate again we simply + + align:start position:0% +gate and the and gate again we simply + + + align:start position:0% +gate and the and gate again we simply +walk through each combination of inputs + + align:start position:0% +walk through each combination of inputs + + + align:start position:0% +walk through each combination of inputs +and specify the outputs produced by the + + align:start position:0% +and specify the outputs produced by the + + + align:start position:0% +and specify the outputs produced by the +second or gate when both inputs are 0 + + align:start position:0% +second or gate when both inputs are 0 + + + align:start position:0% +second or gate when both inputs are 0 +the output is 1 when one input is 0 and + + align:start position:0% +the output is 1 when one input is 0 and + + + align:start position:0% +the output is 1 when one input is 0 and +the other is a 1 the output is a 0 + + align:start position:0% +the other is a 1 the output is a 0 + + + align:start position:0% +the other is a 1 the output is a 0 +finally we take those outputs together + + align:start position:0% +finally we take those outputs together + + + align:start position:0% +finally we take those outputs together +with the outputs of the or gate and + + align:start position:0% +with the outputs of the or gate and + + + align:start position:0% +with the outputs of the or gate and +generate the final output of the circuit + + align:start position:0% +generate the final output of the circuit + + + align:start position:0% +generate the final output of the circuit +at the output of the NAND gate here when + + align:start position:0% +at the output of the NAND gate here when + + + align:start position:0% +at the output of the NAND gate here when +both inputs are 1 we get a 0 output + + align:start position:0% +both inputs are 1 we get a 0 output + + + align:start position:0% +both inputs are 1 we get a 0 output +otherwise the output is a 1 + + align:start position:0% +otherwise the output is a 1 + + + align:start position:0% +otherwise the output is a 1 +this nand column of our truth table is + + align:start position:0% +this nand column of our truth table is + + + align:start position:0% +this nand column of our truth table is +the resulting output H now that we have + + align:start position:0% +the resulting output H now that we have + + + align:start position:0% +the resulting output H now that we have +evaluated what our output H is equal to + + align:start position:0% +evaluated what our output H is equal to + + + align:start position:0% +evaluated what our output H is equal to +for each combination of a and B we can + + align:start position:0% +for each combination of a and B we can + + + align:start position:0% +for each combination of a and B we can +represent the circuit as a single truth + + align:start position:0% +represent the circuit as a single truth + + + align:start position:0% +represent the circuit as a single truth +table whose inputs are a and B and whose + + align:start position:0% +table whose inputs are a and B and whose + + + align:start position:0% +table whose inputs are a and B and whose +output is H at this point we can express + + align:start position:0% +output is H at this point we can express + + + align:start position:0% +output is H at this point we can express +the function H as a combination of all + + align:start position:0% +the function H as a combination of all + + + align:start position:0% +the function H as a combination of all +the cases that make H equal to 1 this + + align:start position:0% +the cases that make H equal to 1 this + + + align:start position:0% +the cases that make H equal to 1 this +occurs if a and B are both equal to 0 or + + align:start position:0% +occurs if a and B are both equal to 0 or + + + align:start position:0% +occurs if a and B are both equal to 0 or +if a equals 0 and B equals 1 or if a and + + align:start position:0% +if a equals 0 and B equals 1 or if a and + + + align:start position:0% +if a equals 0 and B equals 1 or if a and +B are both equal to 1 this can be + + align:start position:0% +B are both equal to 1 this can be + + + align:start position:0% +B are both equal to 1 this can be +expressed as a boolean logic expression + + align:start position:0% +expressed as a boolean logic expression + + + align:start position:0% +expressed as a boolean logic expression +as follows H equals not a not B or not a + + align:start position:0% +as follows H equals not a not B or not a + + + align:start position:0% +as follows H equals not a not B or not a +B or a B this notation is called the sum + + align:start position:0% +B or a B this notation is called the sum + + + align:start position:0% +B or a B this notation is called the sum +of products notation any sum of products + + align:start position:0% +of products notation any sum of products + + + align:start position:0% +of products notation any sum of products +can be converted into a simple game or + + align:start position:0% +can be converted into a simple game or + + + align:start position:0% +can be converted into a simple game or +presentation of the function using only + + align:start position:0% +presentation of the function using only + + + align:start position:0% +presentation of the function using only +inverters and and or gates by having one + + align:start position:0% +inverters and and or gates by having one + + + align:start position:0% +inverters and and or gates by having one +large or gate that receives as input one + + align:start position:0% +large or gate that receives as input one + + + align:start position:0% +large or gate that receives as input one +and gate per product term inverters are + + align:start position:0% +and gate per product term inverters are + + + align:start position:0% +and gate per product term inverters are +used as needed to compliment the inputs + + align:start position:0% +used as needed to compliment the inputs + + + align:start position:0% +used as needed to compliment the inputs +to the and gates one thing that's + + align:start position:0% +to the and gates one thing that's + + + align:start position:0% +to the and gates one thing that's +interesting to note about this + + align:start position:0% +interesting to note about this + + + align:start position:0% +interesting to note about this +combination of gates is that it can + + align:start position:0% +combination of gates is that it can + + + align:start position:0% +combination of gates is that it can +easily be converted into a circuit that + + align:start position:0% +easily be converted into a circuit that + + + align:start position:0% +easily be converted into a circuit that +consists purely of NAND gates the way to + + align:start position:0% +consists purely of NAND gates the way to + + + align:start position:0% +consists purely of NAND gates the way to +do this is to realize that if you take + + align:start position:0% +do this is to realize that if you take + + + align:start position:0% +do this is to realize that if you take +the output of a gate and invert it twice + + align:start position:0% +the output of a gate and invert it twice + + + align:start position:0% +the output of a gate and invert it twice +you produce the original output this + + align:start position:0% +you produce the original output this + + + align:start position:0% +you produce the original output this +means that we can add two inverters + + align:start position:0% +means that we can add two inverters + + + align:start position:0% +means that we can add two inverters +between each and output and/or input we + + align:start position:0% +between each and output and/or input we + + + align:start position:0% +between each and output and/or input we +can draw these inverters as bubbles + + align:start position:0% +can draw these inverters as bubbles + + + align:start position:0% +can draw these inverters as bubbles +which represent inversion where replace + + align:start position:0% +which represent inversion where replace + + + align:start position:0% +which represent inversion where replace +one bubble on the output of the and gate + + align:start position:0% +one bubble on the output of the and gate + + + align:start position:0% +one bubble on the output of the and gate +and the other bubble at the inputs of + + align:start position:0% +and the other bubble at the inputs of + + + align:start position:0% +and the other bubble at the inputs of +the or gate we know that an and gate + + align:start position:0% +the or gate we know that an and gate + + + align:start position:0% +the or gate we know that an and gate +followed by an inversion is simply a + + align:start position:0% +followed by an inversion is simply a + + + align:start position:0% +followed by an inversion is simply a +NAND gate we also know that an inverter + + align:start position:0% +NAND gate we also know that an inverter + + + align:start position:0% +NAND gate we also know that an inverter +is equivalent to a NAND gate with both + + align:start position:0% +is equivalent to a NAND gate with both + + + align:start position:0% +is equivalent to a NAND gate with both +of its inputs tied together in addition + + align:start position:0% +of its inputs tied together in addition + + + align:start position:0% +of its inputs tied together in addition +using demorgan's law we know that not a + + align:start position:0% +using demorgan's law we know that not a + + + align:start position:0% +using demorgan's law we know that not a +or not + + align:start position:0% +or not + + + align:start position:0% +or not +B is equivalent to not of a and B this + + align:start position:0% +B is equivalent to not of a and B this + + + align:start position:0% +B is equivalent to not of a and B this +means that the bubbles followed by the + + align:start position:0% +means that the bubbles followed by the + + + align:start position:0% +means that the bubbles followed by the +or gate can also be replaced with a NAND + + align:start position:0% +or gate can also be replaced with a NAND + + + align:start position:0% +or gate can also be replaced with a NAND +gate + + align:start position:0% +gate + + + align:start position:0% +gate +thus arriving at our equivalent circuit + + align:start position:0% +thus arriving at our equivalent circuit + + + align:start position:0% +thus arriving at our equivalent circuit +representation consisting purely of NAND + + align:start position:0% +representation consisting purely of NAND + + + align:start position:0% +representation consisting purely of NAND +gates the advantage of using NAND gates + + align:start position:0% +gates the advantage of using NAND gates + + + align:start position:0% +gates the advantage of using NAND gates +to implement the circuit is that NAND + + align:start position:0% +to implement the circuit is that NAND + + + align:start position:0% +to implement the circuit is that NAND +gates are inverting logic where each + + align:start position:0% +gates are inverting logic where each + + + align:start position:0% +gates are inverting logic where each +gate can be implemented as a single CMOS + + align:start position:0% +gate can be implemented as a single CMOS + + + align:start position:0% +gate can be implemented as a single CMOS +gate all functions can be expressed as a + + align:start position:0% +gate all functions can be expressed as a + + + align:start position:0% +gate all functions can be expressed as a +combination of NAND gates so a NAND gate + + align:start position:0% +combination of NAND gates so a NAND gate + + + align:start position:0% +combination of NAND gates so a NAND gate +is considered a universal gate nor gates + + align:start position:0% +is considered a universal gate nor gates + + + align:start position:0% +is considered a universal gate nor gates +are also universal and can be used to + + align:start position:0% +are also universal and can be used to + + + align:start position:0% +are also universal and can be used to +express any function furthermore any + + align:start position:0% +express any function furthermore any + + + align:start position:0% +express any function furthermore any +circuit that can be used to implement + + align:start position:0% +circuit that can be used to implement + + + align:start position:0% +circuit that can be used to implement +any other function is also considered + + align:start position:0% +any other function is also considered + + + align:start position:0% +any other function is also considered +universal to determine if a gate G is + + align:start position:0% +universal to determine if a gate G is + + + align:start position:0% +universal to determine if a gate G is +universal one needs to check if one can + + align:start position:0% +universal one needs to check if one can + + + align:start position:0% +universal one needs to check if one can +convert G into either a NAND or nor gate + + align:start position:0% +convert G into either a NAND or nor gate + + + align:start position:0% +convert G into either a NAND or nor gate +by simply using one or more copies of G + + align:start position:0% +by simply using one or more copies of G + + + align:start position:0% +by simply using one or more copies of G +together with low and high constant + + align:start position:0% +together with low and high constant + + + align:start position:0% +together with low and high constant +inputs \ No newline at end of file diff --git a/zjUDy6a5vx4.txt b/zjUDy6a5vx4.txt new file mode 100644 index 0000000000000000000000000000000000000000..30f7d6d28d5484760bb9e730aee5290f683e5911 --- /dev/null +++ b/zjUDy6a5vx4.txt @@ -0,0 +1,3911 @@ +The last lecture of 6.046. +We are here today to talk more + +about cache oblivious +algorithms. + +Last class, we saw several +cache oblivious algorithms, + +although none of them quite too +difficult. + +Today we will see two difficult +cache oblivious algorithms, + +a little bit more advanced. +I figure we should do something + +advanced for the last class just +to get to some exciting climax. + +So without further ado, +let's get started. + +Last time, we looked at the +binary search problem. + +Or, we looked at binary search, +rather. + +And so, the binary search did +not do so well in the cache + +oblivious context. +And, some people asked me after + +class, is it possible to do +binary search while cache + +obliviously? +And, indeed it is with + +something called static search +trees. + +So, this is really binary +search. + +So, I mean, the abstract +problem is I give you N items, + +say presorted, +build some static data + +structure so that you can search +among those N items quickly. + +And quickly, +I claim, means log base B of N. + +We know that with B trees, +our goal is to get log base B + +of N. +We know that we can achieve + +that with B trees when we know +B. + +We'd like to do that when we +don't know B. + +And that's what cache oblivious +static search trees achieve. + +So here's what we're going to +do. + +As you might suspect, +we're going to use a tree. + +So, we're going to store our N +elements in a complete binary + +tree. +We can't use B trees because we + +don't know what B is. +So, we'll use a binary tree. + +And the key is how we lay out a +binary tree. + +The binary tree will have N +nodes. + +Or, you can put the data in the +leaves. + +It doesn't really matter. +So, here's our tree. + +There are the N nodes. +And we're storing them, + +I didn't say, +in order, you know, + +in the usual way, +in order in a binary tree, + +which makes it a binary search +tree. + +So we now had a search in this +thing. + +So, the search will just start +at the root and a walk down some + +root-to-leaf path. +OK, and each point you know + +whether to go left or to go +right because things are in + +order. +So we're assuming here that we + +have an ordered universe of +keys. + +So that's easy. +We know that that will take log + +N time. +The question is how many memory + +transfers? +We'd like a lot of the nodes + +near the root to be somehow +closer and one block. + +But we don't know what the +block size is. + +So are going to do is carve the +tree in the middle level. + +We're going to use divide and +conquer for our layout of the + +tree, how we order the nodes in +memory. + +And the divide and conquer is +based on cutting in the middle, + +which is a bit weird. +It's not our usual divide and + +conquer. +And we'll see this more than + +once today. +So, when you cut on the middle + +level, if the height of your +original tree is log N, + +maybe log N plus one or +something, it's roughly log N, + +then the top half will be log N +over two. + +And at the height of the bottom +pieces will be log N over two. + +How many nodes will there be in +the top tree? + +N over two? +Not quite. + +Two to the log N over two, +square root of N. + +OK, so it would be about root N +nodes over here. + +And therefore, +there will be about root N + +subtrees down here, +one for each, + +or a couple for each leaf. +OK, so we have these subtrees + +of root N, and there are about +root N of them. + +OK, this is how we are carving +our tree. + +Now, we're going to recurse on +each of the pieces. + +I'd like to redraw this +slightly, sorry, + +just to make it a little bit +clearer. + +These triangles are really +trees, and they are connected by + +edges to this tree up here. +So what we are really doing is + +carving in the middle level of +edges in the tree. + +And if N is not exactly a power +of two, you have to round your + +level by taking floors or +ceilings. + +But you cut roughly in the +middle level of edges. + +There is a lot of edges here. +You conceptually slice there. + +That gives you a top tree and +the bottom tree, + +several bottom trees, +each of size roughly root N. + +OK, and then we are going to +recursively layout these root N + +plus one subtrees, +and then concatenate. + +So, this is the idea of the +recursive layout. + +We sought recursive layouts +with matrices last time. + +This is doing the same thing +for a tree. + +So, I want to recursively +layout the top tree. + +So here's the top tree. +And I imagine it being somehow + +squashed down into a linear +array recursively. + +And then I do the same thing +for each of the bottom trees. + +So here are all the bottom +trees. + +And I squashed each of them +down into some linear order. + +And then I concatenate those +linear orders. + +That's the linear order of the +street. + +And you need a base case. +And the base case, + +just a single node, +is stored in the only order of + +a single node there is. +OK, so that's a recursive + +layout of a binary search tree. +It turns out this works really + +well. +And let's quickly do a little + +example just so it's completely +clear what this layout is + +because it's a bit bizarre maybe +the first time you see it. + +So let me draw my favorite +picture. + +So here's a tree of height four +or three depending on how you + +count. +We divide in the middle level, + +and we say, OK, +that's the top tree. + +And then these are the bottom +trees. + +So there's four bottom trees. +So there are four children + +hanging off the root tree. +They each have the same size in + +this case. +They should all roughly be the + +same size. +And the first we layout the top + +thing where we divide on the +middle level. + +We say, OK, this comes first. +And then, the bottom subtrees + +come next, two and three. +So, I'm writing down the order + +in which these nodes are stored +in an array. + +And then, we visit this tree so +we get four, five, + +six. +And then we visit this one so + +we get seven, +eight, nine. + +And then the subtree, +10, 11, 12, and then the last + +subtree. +So that's the order in which + +you store these 15 nodes. +And you can build that up + +recursively. +OK, so the structure is fairly + +simple, just a binary structure +which we know and love, + +but store it in this funny +order. + +This is not depth research +order or level order, + +lots of natural things you +might try, none of which work in + +cache oblivious context. +This is pretty much the only + +thing that works. +And the intuition as, + +well, we are trying to mimic +all kinds of B trees. + +So, if you want a binary tree, +well, that's the original tree. + +It doesn't matter how you store +things. + +If you want a tree where the +branching factor is four, + +well, then here it is. +These blocks give you a + +branching factor of four. +If we had more leaves down + +here, there would be four +children hanging off of that + +node. +And these are all clustered + +together consecutively in +memory. + +So, if your block size happens +to be three, then this is a + +perfect way to store things for +a block size of three. + +If you're block size happens to +be probably 15, + +right, if we count the number +of, right, the number of nodes + +in here is 15, +if you're block size happens to + +be 15, then this recursion will +give you a perfect blocking in + +terms of 15. +And in general, + +it's actually mimicking block +sizes of 2^K-1. + +Think powers of two. +OK, that's the intuition. + +Let me give you the formal +analysis to make it clearer. + +So, we claim that there are +order, log base B of N memory + +transfers. +That's what we want to prove no + +matter what B is. +So here's what we're going to + +do. +You may recall last time when + +we analyzed divide and conquer +algorithms, we wrote our + +recurrence, and that the base +case was the key. + +Here, in fact, +we are only going to think + +about the base case in a certain +sense. + +We don't have, +really, recursion in the + +algorithm. +The algorithm is just walking + +down some root-to-leaf path. +We only have a recursion in a + +definition of the layout. +So, we can be a little bit more + +flexible. +We don't have to look at our + +recurrence. +We are just going to think + +about the base case. +I want to imagine, + +you start with the big +triangle. + +That you cut it in the middle; +you get smaller triangles. + +Imagine the point at which you +keep recursively cutting. + +So imagine this process. +Big triangles halve in height + +each time. +They're getting smaller and + +smaller, stop cutting at the +point where a triangle fits in a + +block. +OK, and look at that time. + +OK, the recursion actually goes +all the way, but in the analysis + +let's think about the point +where the chunk fits in a block + +in one of these triangles, +one of these boxes fits in a + +block. +So, I'm going to call this a + +recursive level. +So, I'm imagining expanding all + +of the recursions in parallel. +This is some level of detail, + +some level of refinement of the +trees at which the tree you're + +looking at, the triangle, +has size. + +In other words, +there is a number of nodes in + +that triangle is less than or +equal to B. + +OK, so let me draw a picture. +So, I want to draw sort of this + +picture but where instead of +nodes, I have little triangles + +of size, at most, +B. + +So, the picture looks something +like this. + +We have a little triangle of +size, at most, + +B. +It has a bunch of children + +which are subtrees of size, +at most, B, the same size. + +And then, these are in a chunk, +and then we have other chunks + +that look like that in recursion +potentially. + +OK, so I haven't drawn +everything. + +There would be a whole bunch +of, between B and B^2, + +in fact, subtrees, +other squares of this size. + +So here, I had to refine the +entire tree here. + +And then I refined each of the +subtrees here and here at these + +levels. +And then it turned out after + +these two recursive levels, +everything fits in a block. + +Everything has the same size, +so at some point they will all + +fit within a block. +And they might actually be + +quite a bit smaller than the +block. + +How small? +So, what I'm doing is cutting + +the number of levels and half at +each point. + +And I stop when the height of +one of these trees is + +essentially at most log B +because that's when the number + +of nodes at there will be B +roughly. + +So, how small can the height +be? + +I keep dividing at half and +stopping when it's, + +at most, log B. +Log B over two. + +So it's, at most, +log B, it's at least half log + +B. +Therefore, the number of nodes + +it here could be between the +square root of B and B. + +So, this could be a lot smaller +and less than a constant factor + +of a block, a claim that doesn't +matter. + +It's OK. +This could be a small square + +root of B. +I'm not even going to write + +that it could be a small square +root of B because that doesn't + +play a role in the analysis. +It's a worry, + +but it's OK essentially because +our bound only involves log B. + +It doesn't involve B. +So, here's what we do. + +We know that each of the height +of one of these triangles of + +size, at most, +B is at least a half log B. + +And therefore, +if you look at a search path, + +so, when we do a search in this +tree, we're going to start up + +here. +And I'm going to mess up the + +diagram now. +We're going to follow some + +path, maybe I should have drawn +it going down here. + +We visit through some of these +triangles, but it's a + +root-to-node path in the tree. +So, how many of the triangles + +could it visit? +Well, the height of the tree + +divided by the height of one of +the triangles. + +So, this visits, +at most, log N over half log B + +triangles, which looks good. +This is log base B of N, + +mind you off factor of two. +Now, what we worry about is how + +many blocks does a triangle +occupy? + +One of these triangles should +fit in a block. + +We know by the recursive +layout, it is stored in a + +consecutive region in memory. +So, how many blocks could + +occupy? +Two, because of alignment, + +it might fall across the +boundary of a block, + +but at most, +one boundary. + +So, it fits in two blocks. +So, each triangle fits in one + +block, but is in, +at most, two blocks, + +memory blocks, +size B depending on alignment. + +So, the number of memory +transfers, in other words, + +a number of blocks we read, +because all we are doing here + +is reading in a search, +is at most two blocks per + +triangle. +There are this many triangles, + +so it's at most, +4 log base B of N, + +OK, which is order log base B +of N. + +And there are papers about +decreasing this constant 4 with + +more sophisticated data +structures. + +You can get it down to a little +bit less than two I think. + +So, there you go. +So not quite as good as B trees + +in terms of the constant, +but pretty good. + +And what's good is that this +data structure works for all B + +at the same time. +This analysis works for all B. + +So, we have a multilevel memory +hierarchy, no problem. + +Any questions about this data +structure? + +This is already pretty +sophisticated, + +but we are going to get even +more sophisticated. + +Next, OK, good, +no questions. + +This is either perfectly clear, +or a little bit difficult, + +or both. +So, now, I debated with myself + +what exactly I would cover next. +There are two natural things I + +could cover, both of which are +complicated. + +My first result in the cache +oblivious world is making this + +data structure dynamic. +So, there is a dynamic B tree + +that's cache oblivious that +works for all values of B. + +And it gets log base B of N, +insert, delete, + +and search. +So, this just gets search in + +log base B of N. +That data structure, + +our first paper was damn +complicated, and then it got + +simplified. +It's now not too hard, + +but it takes a couple of +lectures in an advanced + +algorithms class to teach it. +So, I'm not going to do that. + +But there you go. +It exists. + +Instead, we're going to cover +our favorite problem sorting in + +the cache oblivious context. +And this is quite complicated, + +more than you'd expect, +OK, much more complicated than + +it is in a multithreaded setting +to get the right answer, + +anyway. +Maybe to get the best answer in + +a multithreaded setting is also +complicated. + +The version we got last week +was pretty easy. + +But before we go to cache +oblivious sorting, + +let me talk about cache aware +sorting because we need to know + +what bound we are aiming for. +And just to warn you, + +I may not get to the full +analysis of the full cache + +oblivious sorting. +But I want to give you an idea + +of what goes into it because +it's pretty cool, + +I think, a lot of ideas. +So, how might you sort? + +So, cache aware, +we assume we can do everything. + +Basically, this means we have B +trees. + +That's the only other structure +we know. + +How would you sort N numbers, +given that that's the only data + +structure you have? +Right, just add them into the B + +tree, and then do an in-order +traversal. + +That's one way to sort, +perfectly reasonable. + +We'll call it repeated +insertion into a B tree. + +OK, we know in the usual +setting, and the BST sort, + +where you use a balanced binary +search tree, like red-black + +trees, that takes N log N time, +log N per operation, + +and that's an optimal sorting +algorithm in the comparison + +model, only thinking about +comparison model here. + +So, how many memory transfers +does this data structure takes? + +Sorry, this algorithm for +sorting? + +The number of memory transfers +is a function of N, + +and B_M of N is? +This is easy. + +N insertions, +OK, you have to think about N + +order traversal. +You have to remember back your + +analysis of B trees, +but this is not too hard. + +How long does the insertion +take, the N insertions? + +N log base B of N. +How long does the traversal + +take? +Less time. + +If we think about it, +you can get away with N over B + +memory transfers, +so quite a bit less than this. + +This is bigger than N, +which is actually pretty bad. + +N memory transfers means +essentially you're doing random + +access, visiting every element +in some random order. + +It's even worse. +There's even a log factor. + +Now, the log factor goes down +by this log B factor. + +But, this is actually a really +bad sorting bound. + +So, unlike normal algorithms, +where using a search tree is a + +good way to sort, +in cache oblivious or cache + +aware sorting it's really, +really bad. + +So, what's another natural +algorithm you might try, + +given what we know for sorting? +And, even cache oblivious, + +all the algorithms we've seen +are cache oblivious. + +So, what's a good one to try? +Merge sort. + +OK, we did merge sort in +multithreaded algorithms. + +Let's try a merge sort, +a good divide and conquer + +thing. +So, I'm going to call it binary + +merge sort because it splits the +array into two pieces, + +and it recurses on the two +pieces. + +So, you get a binary recursion +tree. + +So, let's analyze it. +So the number of memory + +transfers on N elements, +so I mean it has a pretty good + +recursive layout, +right? + +The two subarrays that we get +what we partition our array are + +consecutive. +So, we're recursing on this, + +recursing on this. +So, it's a nice cache oblivious + +layout. +And this is even for cache + +aware. +This is a pretty good + +algorithm, a lot better than +this one, as we'll see. + +But, what is the recurrence we +get? + +So, here we have to go back to +last lecture when we were + +thinking about recurrences for +recursive cache oblivious + +algorithms. + +I mean, the first part should +be pretty easy. + +There's an O. +Well, OK, let's put the O at + +the end, the divide and the +conquer part at the end. + +The recursion is 2MT of N over +two, good. + +All right, that's just like the +merge sort recurrence, + +and that's the additive term +that you're thinking about. + +OK, so normally, +we would pay a linear additive + +term here, order N because +merging takes order N time. + +Now, we are merging, +which is three parallel scans, + +the two inputs and the output. +OK, they're not quite parallel + +interleaved. +They're a bit funnily + +interleaved, but as long as your +cache stores at least three + +blocks, this is also linear time +in this setting, + +which means you visit each +block a constant number of + +times. +OK, that's the recurrence. + +Now, we also need a base case, +of course. + +We've seen two base cases, +one MT of B, + +and the other, +MT of whatever fits in cache. + +So, let's look at that one +because it's better. + +So, for some constant, +C, if I have an array of size + +M, this fits in cache, +actually, probably C is one + +here, but I'll just be careful. +For some constant, + +this fits in cache. +A problem of this size fits in + +cache, and in that case, +the number of memory transfers + +is, anyone remember? +We've used this base case more + +than once before. +Do you remember? + +Sorry? +CM over B. + +I've got a big O, +so M over B. + +Order M over B because this is +the size of the data. + +So, I mean, just to read it all +in takes M over B. + +Once it's in cache, +it doesn't really matter what I + +do as long as I use linear space +for the right constant here. + +As long as I use linear space +in that algorithm, + +I'll stay in cache, +and therefore, + +not have to write anything out +until the very end and I spend M + +over B to write it out. +OK, so I can't really spend + +more than M over B almost no +matter what algorithm I have, + +so long as it uses linear +space. + +So, this is a base case that's +useful pretty much in any + +algorithm. +OK, that's a recurrence. + +Now we just have to solve it. +OK, let's see how good binary + +merge sort is. +OK, and again, + +I'm going to just give the +intuition behind the solution to + +this recurrence. +And I won't use the + +substitution method to prove it +formally. + +But this one's actually pretty +simple. + +So, we have, +at the top, actually I'm going + +to write it over here. +Otherwise I won't be able to + +see. +So, at the top of the + +recursion, we have N over B +costs. + +I'll ignore the constants. +There is probably also on + +additive one, +which I'm ignoring here. + +Then we split into two problems +of half the size. + +So, we get a half N over B, +and a half N over B. + +OK, usually this was N, +half N, half N. + +You should regard it as from +lecture one. + +So, the total on this level is +N over B. + +The total on this level is N +over B. + +And, you can prove by +induction, that every level is N + +over B. +The question is how many levels + +are there? +Well, at the bottom, + +so, dot, dot, +dot, at the bottom of this + +recursion tree we should get +something of size M, + +and then we're paying M over B. +Actually here we're paying M + +over B. +So, it's a good thing those + +match. +They should. + +So here, we have a bunch of +leaves, all the size M over B. + +You can also compute the number +of leaves here is N over M. + +If you want to be extra sure, +you should always check the + +leaf level. +It's a good idea. + +So we have N over M leaves, +each costing M over B. + +This is an M. +So, this is N over B also. + +So, every level here is N over +B memory transfers. + +And the number of levels is one +N over B? + +Log N over B. +Yep, that's right. + +I just didn't hear it right. +OK, we are starting at N. + +We're getting down to M. +So, you can think of it as log + +N, the whole binary tree minus +the subtrees log M, + +and that's the same as log N +over M, OK, or however you want + +to think about it. +The point is that this is a log + +base two. +That's where we are not doing + +so great. +So this is actually a pretty + +good algorithm. +So let me write the solution + +over here. +So, the number of memory + +transfers on N items is going to +be the number of levels times + +the cost of each level. +So, this is N over B times log + +base two of N over M, +which is a lot better than + +repeated insertion into a B +tree. + +Here, we were getting N times +log N over log B, + +OK, so N log N over log B. +We're getting a log B savings + +over not proving anything, +and here we are getting a + +factor of B savings, +N log N over B. + +In fact, we even made it a +little bit smaller by dividing + +this N by M. +That doesn't matter too much. + +This dividing by B is a big +one. + +OK, so we're almost there. +This is almost an optimal + +algorithm. +It's even cache oblivious, + +which is pretty cool. +And that extra little step, + +which is that you should be +able to get on other log B + +factor improvement, +I want to combine these two + +ideas. +I want to keep this factor B + +improvement over N log N, +and I want to keep this factor + +log B improvement over N log N, +and get them together. + +So, first, before we do that +cache obliviously, + +let's do it cache aware. +So, this is the third cache + +aware algorithm. +This one was also cache + +oblivious. +So, how should I modify a merge + +sort in order to do better? +I mean, I have this log base + +two, and I want a log base B, +more or less. + +So, how would I do that with +merge sort? + +Yeah? +Split into B subarrays, + +yeah. +Instead of doing binary merge + +sort, this is what I was hinting +at here, instead of splitting it + +into two pieces, +and recursing on the two + +pieces, and then merging them, +I could split potentially into + +more pieces. +OK, and to do that, + +I'm going to use my cache. +So the idea is B pieces. + +This is actually not the best +thing to do, although B pieces + +does work. +And, it's what I was hinting at + +because I was saying I want a +log B. + +It's actually not quite log B. +It's log M over B. + +OK, but let's see. +So, what is the most pieces I + +could split into? +Right, well, + +I could split into N pieces. +That would be good, + +wouldn't it, +at only one recursive level? + +I can't split into N pieces. +Why? + +What happens wrong when I split +into N pieces? + +That would be the ultimate. +You can't merge, + +exactly. +So, if I have N pieces, + +you can't merge in cache. +I mean, so in order to merge in + +cache, what I need is to be able +to store an entire block from + +each of the lists that I'm +merging. + +If I can store an entire block +in cache for each of the lists, + +then it's a bunch of parallel +scans. + +So this is like testing the +limit of parallel scanning + +technology. +If you have K parallel scans, + +and you can fit K blocks in +cache, then all is well because + +you can scan through each of +those K arrays, + +and have one block from each of +the K arrays in cache at the + +same time. +So, that's the idea. + +Now, how many blocks can I fit +in cache? + +M over B. +That's the biggest I could do. + +So this will give the best +running time among these kinds + +of merge sort algorithms. +This is an M over B way merge + +sort. +OK, so now we get somewhat + +better recurrence. +We split into M over B + +subproblems now, +each of size, + +well, it's N divided by M over +B without thinking. + +And, the claim is that the +merge time is still linear + +because we have barely enough, +OK, maybe I should describe + +this algorithm. +So, we divide, + +because we've never really done +non-binary merge sort. + +We divide into M over B equal +size subarrays instead of two. + +Here, we are clearly doing a +cache aware algorithm. + +We are assuming we know what M +over B is. + +So, then we recursively sort +each subarray, + +and then we conquer. +We merge. + +And, the reason merge works is +because we can afford one block + +in cache. +So, let's call it one cache + +block per subarray. +OK, actually, + +if you're careful, +you also need one block for the + +output of the merged array +before you write it out. + +So, it should be M over B minus +one. + +But, let's ignore some additive +constants. + +OK, so this is the recurrence +we get. + +The base case is the same. +And, what improves here? + +I mean, the per level cost +doesn't change, + +I claim, because at the top we +get N over B. + +This does before. +Then we split into M over B + +subproblems, each of which costs +a one over M over B factor times + +N over B. +OK, so you add all those up, + +you still get N over B because +we are not decreasing the number + +of elements. +We're just splitting them. + +There's now M over B +subproblems, each of one over M + +over B the size. +So, just like before, + +each level will sum to N over +B. + +What changes is the number of +levels because now we have + +bigger branching factor. +Instead of log base two, + +it's now log base the branching +factor. + +So, the height of this tree is +log base M over B of N over M, + +I believe. +Let me make sure that agrees + +with me. +Yeah. + +OK, and if you're careful, +this counts not quite the + +number of levels, +but the number of levels minus + +one. +So, I'm going to one plus one + +here. +And the reason why is this is + +not quite the bound that I want. +So, we have log base M over B. + +What I really want, +actually, is N over B. + +I claim that these are the same +because we have minus, + +yeah, that's good. +OK, this should come as rather + +mysterious, but it's because I +know what the sorting bound + +should be as I'm doing this +arithmetic. + +So, I'm taking log base M over +B of N over M. + +I'm not changing the base of +the log. + +I'm just saying, +well, N over M, + +that is N over B divided by M +over B because then the B's + +cancel, and the M goes on the +bottom. + +So, if I do that in the logs, +I get log of N over B minus log + +of M over B minus, +because I'm dividing. + +OK, now, log base M over B of M +over B is one. + +So, these cancel, +and I get log base M over B, + +N over B, which is what I was +aiming for. + +Why? +Because that's the right bound + +as it's normally written. +OK, that's what we will be + +trying to get cache obliviously. +So, that's the height of the + +search tree, and at each level +we are paying N over B memory + +transfers. +So, the overall number of + +memory transfers for this M over +B way merge sort is the sorting + +bound. + +This is, I'll put it in a box. +This is the sorting bound, + +and it's very special because +it is the optimal number of + +memory transfers for sorting N +items cache aware. + +This has been known since, +like, 1983. + +OK, this is the best thing to +do. + +It's a really weird bound, +but if you ignore all the + +divided by B's, +it's sort of like N times log + +base M of N. +So, that's little bit more + +reasonable. +But, there's lots of divided by + +B's. +So, the number of the blocks in + +the input times log base the +number of blocks in the cache of + +the number of blocks in the +input. + +That's a little bit more +intuitive. + +That is the bound. +And that's what we are aiming + +for. +So, this algorithm, + +crucially, assume that we knew +what M over B was. + +Now, we are going to try and do +it without knowing M over B, + +do it cache obliviously. +And that is the result of only + +a few years ago. +Are you ready? + +Everything clear so far? +It's a pretty natural + +algorithm. +We were going to try to mimic + +it essentially and do a merge +sort, but not M over B way merge + +sort because we don't know how. +We're going to try and do it + +essentially a square root of N +way merge sort. + +If you play around, +that's the natural thing to do. + +The tricky part is that it's +hard to merge square root of N + +lists at the same time, +in a cache efficient way. + +We know that if the square root +of N is bigger than M over B, + +you're hosed if you just do a +straightforward merge. + +So, we need a fancy merge. +We are going to do a divide and + +conquer merge. +It's a lot like the + +multithreaded algorithms of last +week, try and do a divide and + +conquer merge so that no matter +how many lists are merging, + +as long as it's less than the +square root of N, + +or actually cubed root of N, +we can do it cache efficiently, + +OK? +So, we'll do this, + +we need a bit of setup. +But that's where we're going, + +cache oblivious sorting. +So, we want to get the sorting + +bound, and, yeah. +It turns out, + +to do cache oblivious sorting, +you need an assumption about + +the cache size. +This is kind of annoying, + +because we said, +well, cache oblivious + +algorithms should work for all +values of B and all values of M. + +But, you can actually prove you +need an additional assumption in + +order to get this bound cache +obliviously. + +That's the result of, +like, last year by Garrett + +Brodel. +So, and the assumption is, + +well, the assumption is fairly +weak. + +That's the good news. +OK, we've actually made an + +assumption several times. +We said, well, + +assuming the cache can store at +least three blocks, + +or assuming the cache can store +at least four blocks, + +yeah, it's reasonable to say +the cache can store at least + +four blocks, or at least any +constant number of blocks. + +This is that the number of +blocks that your cache can store + +is at least B to the epsilon +blocks. + +This is saying your cache +isn't, like, really narrow. + +It's about as tall as it is +wide. + +This actually gives you a lot +of sloth. + +And, we're going to use a +simple version of this + +assumption that M is at least +B^2. + +OK, this is pretty natural. +It's saying that your cache is + +at least as tall as it is wide +where these are the blocks. + +OK, the number of blocks is it +least the size of a block. + +That's a pretty reasonable +assumption, and if you look at + +caches these days, +they all satisfy this, + +at least for some epsilon. +Pretty much universally, + +M is at least B^2 or so. +OK, and in fact, + +if you think from our speed of +light arguments from last time, + +B^2 or B^3 is actually the +right thing to do. + +As you go out, +I guess in 3-D, + +B^2 would be the surface area +of the sphere out there. + +OK, so this is actually the +natural thing of how much space + +you should have at a particular +distance. + +Assuming we live in a constant +dimensional space, + +that assumption would be true. +This even allows going up to 42 + +dimensions or whatever, +OK, so a pretty reasonable + +assumption. +Good. + +Now, we are going to achieve +this bound. + +And what we are going to try to +do is use an N to the epsilon + +way merge sort for some epsilon. +And, if we assume that M is at + +least B^2, the epsilon will be +one third, it turns out. + +So, we are going to do the +cubed root of N way merge sort. + +I'll start by giving you and +analyzing the sorting + +algorithms, assuming that we +know how to do merge in a + +particular bound. +OK, then we'll do the merge. + +The merge is the hard part. +OK, so the merge, + +I'm going to give you the black +box first of all. + +First of all, +what does merge do? + +The K way merger is called the +K funnel just because it looks + +like a funnel, +which you'll see. + +So, a K funnel is a data +structure, or is an algorithm, + +let's say, that looks like a +data structure. + +And it merges K sorted lists. +So, supposing you already have + +K lists, and they're sorted, +and assuming that the lists are + +relatively long, +so we need some additional + +assumptions for this black box +to work, and we'll be able to + +get them as we sort. +We want the total size of those + +lists. +You add up all the elements, + +and all the lists should have +size at least K^3 is the + +assumption. +Then, it merges these lists + +using essentially the sorting +bound. + +Actually, I should really say +theta K^3. + +I also don't want to be too +much bigger than K^3. + +Sorry about that. +So, the number of memory + +transfers that this funnel +merger uses is the sorting bound + +on K^3, so K^3 over B, +log base M over B of K^3 over + +B, plus another K memory +transfers. + +Now, K memory transfers is +pretty reasonable. + +You've got to at least start +reading each list, + +so you got to pay one memory +transfer per list. + +OK, but our challenge in some +sense will be getting rid of + +this plus K. +This is how fast we can merge. + +We'll do that after. +Now, assuming we have this, + +let me tell you how to sort. +This is, eventually enough, + +called funnel sort. +But in a certain sense, + +it's really cubed root of N way +merge sort. + +OK, but we'll analyze it using +this. + +OK, so funnel sort, +we are going to define K to be + +N to the one third, +and apply this merger. + +So, what do we do? +It's just like here. + +We're going to divide our array +into N to the one third. + +I mean, it they should be +consecutive subarrays. + +I'll call them segments of the +array. + +OK, for cache oblivious, +it's really crucial how these + +things are laid out. +We're going to cut and get + +consecutive chunks of the array, +N to the one third of them. + +Then I'm going to recursively +sort them, and then I'm going to + +merge. +OK, and I'm going to merge + +using the K funnel, +the N to the one third funnel + +because, now, +why do I use one third? + +Well, because of this three. +OK, in order to use the N to + +the one third funnel, +I need to guarantee that the + +total number of elements that +I'm merging is at least the cube + +of this number, +K^3. + +The cube of this number is N. +That's exactly how many + +elements I have in total. +OK, so this is exactly what I + +can apply the funnel. +It's going to require that I + +have it least K^3 elements, +so that I can only use an N to + +the one third funnel. +I mean, if it didn't have this + +requirement, I could just say, +well, I have N lists each of + +size one. +OK, that's clearly not going to + +work very well for our merger, +I mean, intuitively because + +this plus K will kill you. +That will be a plus M which is + +way too big. +But we can use an N to the one + +third funnel, +and this is how we would sort. + +So, let's analyze this +algorithm. + +Hopefully, it will give the +sorting bound if I did + +everything correctly. +OK, this is pretty easy. + +The only thing that makes this +messy as I have to write the + +sorting bound over and over. +OK, this is the cost of the + +merge. +So that's at the root. + +But K^3 in this case is N. +So at the root of the + +recursion, let me write the +recurrence first. + +Sorry. +So, we have memory transfers on + +N elements is N to the one +third. + +Let me get this right. +Yeah, N to the one third + +recursions, each of size N to +the two thirds, + +OK, plus this time, +except K^3 is N. + +So, this is plus N over B, +log base M over B of N over B + +plus cubed root of M. +This is additive plus K term. + +OK, so that's my recurrence. +The base case will be the + +usual. +MT is some constant times M is + +order M over B. +So, we sort of know what we + +should get here. +Well, not really. + +So, in all the previous +recurrence is, + +we have the same costs at every +level, and that's where we got + +our log factor. +Now, we already have a log + +factor, so we better not get +another one. + +Right, this is the bound we +want to prove. + +So, let me cheat here for a +second. + +All right, indeed. +You may already be wondering, + +this N to the one third seems +rather large. + +If it's bigger than this, +we are already in trouble at + +the very top level of the +recursion. + +So, I claim that that's OK. +Let's look at N to the one + +third. +OK, there is a base case here + +which covers all values of N +that are, at most, + +some constant times N. +So, if I'm in this case, + +I know that N is at least as +big as the cache up to some + +constant. +OK, now the cache is it least + +B^2, we've assumed. +And you can do this with B to + +the one plus epsilon if you're +more careful. + +So, N is at least B^2, +OK? + +And then, I always have trouble +with these. + +So this means that N divided by +B is omega root N. + +OK, there's many things you +could say here, + +and only one of them is right. +So, why? + +So this says that the square +root of N is at least B, + +and so N divided by B is at +most N divided by square root of + +N. +So that's at least the square + +root of N if you check that all +out. + +I'm going to go through this +arithmetic relatively quickly + +because it's tedious but +necessary. + +OK, the square root of N is +strictly bigger than cubed root + +of N. +OK, so that means that N over B + +is strictly bigger than N to the +one third. + +Here we have N over B times +something that's bigger than + +one. +So this term definitely + +dominates this term in this +case. + +As long as I'm not in the base +case, I know N is at least order + +M. +This term disappears from my + +recurrence. +OK, so, good. + +That was a bit close. +Now, what we want to get is + +this running time overall. +So, the recursive cost better + +be small, better be less than +the constant factor increase + +over this. +So, let's write the recurrence. + +So, we get N over B, +log base M over B, + +N over B at the root. +Then, we split into a lot of + +subproblems, N to the one third +subproblems here, + +and each one costs essentially +this but with N replaced by N to + +the two thirds. +OK, so N to the two thirds log + +base M over B, +oops I forgot to divide it by B + +out here, of N to the two thirds +divided by B. + +That's the cost of one of these +nodes, N to the one third of + +them. +What should they add up to? + +Well, there is N to the one +third, and there's an N to the + +two thirds here that multiplies +out to N. + +So, we get N over B. +This looks bad. + +This looks the same. +And we don't want to lose + +another log factor. +But the good news is we have + +two thirds in here. +OK, this is what we get in + +total at this level. +It looks like the sorting + +bound, but in the log there's +still a two thirds. + +Now, a power of two thirds and +a log comes out as a multiple of + +two thirds. +So, this is in fact two thirds + +times N over B, +log base M over B of N over B, + +the sorting bound. +So, this is two thirds of the + +sorting bound. +And this is the sorting bound, + +one times the sorting bound. +So, it's going down + +geometrically, +yea! + +OK, I'm not going to prove it, +but it's true. + +This went down by a factor of +two thirds. + +The next one will also go down +by a factor of two thirds by + +induction. +OK, if you prove it at one + +level, it should be true at all +of them. + +And I'm going to skip the +details there. + +So, we could check the leaf +level just to make sure. + +That's always a good sanity +check. + +At the leaves, +we know our cost is M over B. + +OK, and how many leaves are +there? + +Just like before, +in some sense, + +we have N/M leaves. +OK, so in fact the total cost + +at the bottom is N over B. +And it turns out that that's + +what you get. +So, you essentially, + +it looks funny, +because you'd think that this + +would actually be smaller than +this at some intuitive level. + +It's not. +In fact, what's happening is + +you have this N over B times +this log thing, + +whatever the log thing is. +We don't care too much. + +Let's just call it log. +What you are taking at the next + +level is two thirds times that +log. + +And at the next level, +it's four ninths times that log + +and so on. +So, it's geometrically + +decreasing until the log gets +down to one. + +And then you stop the +recursion. + +And that's what you get N over +B here with no log. + +So, what you're doing is +decreasing the log, + +not the N over B stuff. +The two thirds should really be + +over here. +In fact, the number of levels + +here is log, log N. +It's the number of times you + +have to divide a log by three +halves before you get down to + +one, OK? +So, we don't actually need + +that. +We don't care how many levels + +are because it's geometrically +decreasing. + +It could be infinitely many +levels. + +It's geometrically decreasing, +and we get this as our running + +time. +MT of N is the sorting bound + +for funnel sort. +So, this is great. + +As long as we can get a funnel +that merges this quickly, + +we get a sorting algorithm that +sorts as fast as it possibly + +can. +I didn't write that on the + +board that this is +asymptotically optimal. + +Even if you knew what B and M +were, this is the best that you + +could hope to do. +And here, we are doing it no + +matter what, B and M are. +Good. + +Get ready for the funnel. +The funnel will be another + +recursion. +So, this is a recursive + +algorithm in a recursive +algorithm. + +It's another divide and +conquer, kind of like the static + +search trees we saw at the +beginning of this lecture. + +So, these all tie together. + +All right, the K funnel, +so, I'm calling it K funnel + +because I want to think of it at +some recursive level, + +not just N to the one third. +OK, we're going to recursively + +use, in fact, +the square root of K funnel. + +So, here's, and I need to +achieve that bound. + +So, the recursion is like the +static search tree, + +and a little bit hard to draw +on one board, + +but here we go. +So, we have a square root of K + +funnel. +Recursively, + +we have a buffer up here. +This is called the output + +buffer, and it has size K^3, +and just for kicks, + +let's suppose it that filled up +a little bit. + +And, we have some more buffers. +And, let's suppose they've been + +filled up by different amounts. +And each of these has size K to + +the three halves, +of course. + +Halves, these are called +buffers, let's say, + +with the intermediate buffers. +And, then hanging off of them, + +we have more funnels, +the square root of K funnel + +here, and a square root of K +funnel here, one for each + +buffer, one for each child of +this funnel. + +OK, and then hanging off of +these funnels are the input + +arrays. + +OK, I'm not going to draw all K +of them, but there are K input + +arrays, input lists let's call +them down at the bottom. + +OK, so the idea is we are going +to merge bottom-up in this + +picture. +We start with our K input + +arrays of total size at least +K^3. + +That's what we're assuming we +have up here. + +We are clustering them into +groups of size square root of K, + +so, the square root of K +groups, throw each of them into + +a square root of K funnel that +recursively merges those square + +root of K lists. +The output of those funnels we + +are putting into a buffer to +sort of accumulate what the + +answer should be. +These buffers have besides + +exactly K to the three halves, +which might not be perfect + +because we know that on average, +there should be K to the three + +halves elements in each of these +because there's K^3 total, + +and the square root of K +groups. + +So, it should be K^3 divided by +the square root of K, + +which is K to the three halves +on average. + +But some of these will be +bigger. + +Some of them will be smaller. +I've drawn it here. + +Some of them had emptied a bit +more depending on how you merge + +things. +But on average, + +these will all fill at the same +time. + +And then, we plug them into a +square root of K funnel, + +and that we get the output of +size K^3. + +So, that is roughly what we +should have happen. + +OK, but in fact, +some of these might fill first, + +and we have to do some merging +in order to empty a buffer, + +make room for more stuff coming +up. + +That's the picture. +Now, before I actually tell you + +what the algorithm is, +or analyze the algorithm, + +let's first just think about +space, a very simple warm-up + +analysis. +So, let's look at the space + +excluding the inputs and +outputs, those buffers. + +OK, why do I want to exclude +input and output buffers? + +Well, because I want to only +count each buffer once, + +and this buffer is actually the +input to this one and the output + +to this one. +So, in order to recursively + +count all the buffers exactly +once, I'm only going to count + +these middle buffers. +And then separately, + +I'm going to have to think of +the overall output and input + +buffers. +But those are sort of given. + +I mean, I need K^3 for the +output. + +I need K^3 for the input. +So ignore those overall. + +And that if I count the middle +buffers recursively, + +I'll get all the buffers. +So, then we get a very simple + +recurrence for space. +S of K is roughly square root + +of K plus one times S of square +root of K plus order K^2, + +K^2 because we have the square +root of K of these buffers, + +each of size K to the three +halves. + +Work that out, +does that sound right? + +That sounds an awful lot like +K^3, but maybe, + +all right. +Oh, no, that's right. + +It's K to the three halves +times the square root of K, + +which is K to the three halves +plus a half, which is K to the + +four halves, which is K^2. +Phew, OK, good. + +I'm just bad with my arithmetic +here. + +OK, so K^2 total buffering +here. + +You add them up for each level, +each recursion, + +and the plus one here is to +take into account the top guy, + +the square root of K bottom +guys, so the square root of K + +plus one. +If this were, + +well, let me just draw the +recurrence tree. + +There's many ways you could +solve this recurrence. + +A natural one is instead of +looking at K, + +you look at log K, +because here at log K is + +getting divided by two. +I just going to draw the + +recursion trees, +so you can see the intuition. + +But if you are going to solve +it, you should probably take the + +logs, substitute by log. +So, we have the square root of + +K. +plus one branching factor. + +And then, the problem is size +square root of K, + +so this is going to be K, +I believe, for each of these. + +This is square root of K +squared is the cost of these + +levels. +And, you keep going. + +I don't particularly care what +the bottom looks like because at + +the top we have K^2. +That we have K times root K + +plus one cost at the next level. +This is K to the three halves + +plus K. +OK, so we go from K^2 to K to + +the three halves plus K. +This is a super-geometric. + +It's like an exponential +geometric decrease. + +This is decreasing really fast. +So, it's order K^2. + +That's my hand-waving argument. +OK, so the cost is basically + +the size of the buffers at the +top level, the total space. + +We're going to need this. +It's actually theta K^2 because + +I have a theta K^2 here. +We are going to be this in + +order to analyze the time. +That's why it mentioned it. + +It's not just a good feeling +that the space is not too big. + +In fact, the funnel is a lot +smaller than a total input size. + +The input size is K^3. +But that's not so crucial. + +What's crucial is that it's +K^2, and we'll use that in the + +analysis. +OK, naturally, + +this thing is laid out +recursively. + +You recursively store the +funnel, top funnel. + +Then, for example, +you write out each buffer as a + +consecutive array, +in this case. + +There's no recursion there. +So just write them all out one + +by one. +Don't interleave them or + +anything. +Store them in order. + +And that, you write out +recursively these funnels, + +the bottom funnels. +OK, any way you do it + +recursively, as long as each +funnel remains a consecutive + +chunk of memory, +each buffer remains a + +consecutive chuck of memory, +the time analysis that we are + +about to do will work. + +OK, let me actually give you +the algorithm that we're + +analyzing. +In order to make the funnel go, + +what we do is say, +initially, all the buffers are + +empty. +Everything is at the bottom. + +And what we are going to do is, +say, fill the root buffer. + +Fill this one. +And, that's a recursive + +algorithm, which I'll define in +a second, how to fill a buffer. + +Once it's filled, +that means everything has been + +pulled up, and then it's merged. +OK, so that's how we get + +started. +So, merge means to merge + +algorithm is fill the topmost +buffer, the topmost output + +buffer. +OK, and now, + +here's how you fill a buffer. +So, in general, + +if you expand out this +recursion all the way, + +in the base case, +I didn't mention you sort of + +get a little node there. +So, if you look at an arbitrary + +buffer in this picture that you +want to fill, + +so this one's empty and you +want to fill it, + +then immediately below it will +be a vertex who has two + +children, two other buffers. +OK, maybe they look like this. + +You have no idea how big they +are, except they are the same + +size. +It could be a lot smaller than + +this one, a lot bigger, +we don't know. + +But in the end, +you do get a binary structure + +out of this just like we did +with the binary search tree at + +the beginning. +So, how do we fill this buffer? + +Well, we just merge these two +child buffers as long as we can. + +So, we merge the two children +buffers as long as they are both + +non-empty. +So, in general, + +the invariant will be that this +buffer, let me write down a + +sentence. +As long as a buffer is + +non-empty, or whatever is in +that buffer, and hasn't been + +used already, +it's a prefix of the merged + +output of the entire subtree +beneath it. + +OK, so this is a partially +merged subsequence of everything + +down here. +This is a partially merged + +subsequence of everything down +here. + +I can just merge element by +element off the top, + +and that will give me outputs +to put there until one of them + +gets emptied. +And, we have no idea which one + +will empty first just because it +depends on the order. + +OK, whenever one of them +empties, we recursively fill it, + +and that's it. +That's the algorithm. + +Whenever one empties -- + +-- we recursively fill it. +And at the base case at the + +leaves, there's sort of nothing +to do. + +I believe you just sort of +directly read from an input + +list. +So, at the very bottom, + +if you have some note here +that's trying to merge between + +these two, that's just a +straightforward merge between + +two lists. +We know how to do that with two + +parallel scans. +So, in fact, + +we can merge the entire thing +here and just spit it out to the + +buffer. +Well, it depends how big the + +buffer is. +We can only merge it until the + +buffer fills. +Whenever a buffer is full, + +we stop and we pop up the +recursive layers. + +OK, so we keep doing this merge +until the buffer we are trying + +to fill fills, +and that we stop, + +pop up. +OK, that's the algorithm for + +merging. +Now, we just have to analyze + +the algorithm. +It's actually not too hard, + +but it's a pretty clever +analysis. + +And, to top it off, +it's an amortization, + +your favorite. +OK, so we get one last practice + +at amortized analysis in the +context of cache oblivious + +algorithms. +So, this is going to be a bit + +sophisticated. +We are going to combine all the + +ideas we've seen. +The main analysis idea we've + +seen is that we are doing this +recursion in the construction, + +and if we imagine, +we take our K funnel, + +we split it in the middle +level, make a whole bunch of + +square root of K funnels, +and so on, and then we cut + +those in the middle level, +get fourth root of K funnels, + +and so on, and so on, +at some point the funnel we + +look at fits in cache. +OK, before we said if it's in a + +block. +Now, we're going to say that at + +some point, one of these funnels +will fit in cache. + +Each of the funnels at that +recursive level of detail will + +fit in cache. +We are going to analyze that + +level. +We'll call that level J. + +So, consider the first +recursive level of detail, + +and I'll call it J, +at which every J funnel we have + +fits, let's say, +not only does it fit in cache, + +but four of them fit in cache. +It fits in one quarter of the + +cache. +OK, but we need to leave some + +cache extra for doing other +things. + +But I want to make sure that +the J funnel fits. + +OK, now what does that mean? +Well, we've analyzed space. + +We know that the space of a J +funnel is about J^2, + +some constant times J^2. +We'll call it C times J^2. + +OK, so this is saying that C +times J^2 is at most, + +M over 4, one quarter of the +cache. + +OK, that means a J funnel that +happens at the size sits in the + +quarter of the cache. +OK, at some point in the + +recursion, we'll have this big +tree of J funnels, + +with all sorts of buffers in +between them, + +and each of the J funnels will +fit. + +So, let's think about one of +those J funnels. + +Suppose J is like the square +root of K. + +So, this is the picture because +otherwise I have to draw a + +bigger one. +So, suppose this is a J funnel. + +It has a bunch of input +buffers, has one output buffer. + +So, we just want to think about +how the J funnel executes. + +And, for a long time, +as long as these buffers are + +all full, this is just a merger. +It's doing something + +recursively, but we don't really +care. + +As soon as this whole thing +swaps in, and actually, + +I should be drawing this, +as soon as the funnel, + +the output buffer, +and the input buffer swap in, + +in other words, +you bring all those blocks in, + +you can just merge, +and you can go on your merry + +way merging until something +empties or you fill the output. + +So, let's analyze that. +Suppose everything is in + +memory, because we know it fits. +OK, well I have to be a little + +bit careful. +The input buffers are actually + +pretty big in total size because +the total size is K to the three + +halves here versus K to the one +half. + +Actually, this is of size K. +Let me draw a general picture. + +We have a J funnel, +because otherwise the + +arithmetic is going to get +messy. + +We have a J funnel. +Its size is C times J^2, + +we're supposing. +The number of inputs is J, + +and the size of them is pretty +big. + +Where did we define that? +We have a K funnel. + +The total input size is K^3. +So, the total input size here + +would be J^3. +We can't afford to put all that + +in cache. +That's an extra factor of J. + +But, we can afford to one block +per input. + +And for merging, +that's all we need. + +I claim that I can fit the +first block of each of these + +input arrays in cash at the same +time along with the J funnel. + +And so, for that duration, +as long as all of that is in + +cache, this thing can merge at +full speed just like we were + +doing parallel scans. +You use up all the blocks down + +here, and one of them empties. +You go to the next block in the + +input buffer and so on, +just like the normal merge + +analysis of parallel arrays, +at this point we assume that + +everything here is fitting in +cache. + +So, it's just like before. +Of course, in fact, + +it's recursive but we are +analyzing it at this level. + +OK, I need to prove that you +can fit one block per input. + +It's not hard. +It's just computation. + +And, it's basically the way +that these funnels were designed + +was so that you could fit one +block per input buffer. + +And, here's the argument. +So, the claim is you can also + +fit one memory block in the +cache per input buffer. + +So, this is in addition to one +J funnel. + +You could also fit one block +for each of its input buffers. + +OK, this is of the J funnel. +It's not any funnel because + +bigger funnels are way too big. +OK, so here's how we prove + +that. +J^2 is at most a quarter M. + +That's what we assumed here, +actually CJ2. + +I'm not going to bother with +the C because that's going to + +make my life even harder. +OK, I think this is even a + +weaker constraint. +So, the size of our funnel + +proves about J^2. +That's at most a quarter of the + +cache. +That implies that J, + +if we take square roots of both +sides, is at most a half square + +root of M. +OK, also, we know that B is at + +most square root of M because M +is at least B squared. + +So, we put these together, +and we get J times B is at most + +a half M. +OK, now I claim that what we + +are asking for here is J times B +because in a J funnel, + +there are J input arrays. +And so, if you want one block + +each, that costs a space of B +each. + +So, for each input buffer we +have one block of size B, + +and the claim is that that +whole thing fits in half the + +cache. +And, we've only used a quarter + +of the cache. +So in total, + +we use three quarters of the +cache and that's all we'll use. + +OK, so that's good news. +We can also fit one more block + +to the output. +Not too big a deal. + +So now, as long as this J +funnel is running, + +if it's all in cache, +all is well. + +What does that mean? +Let me first analyze how long + +it takes for us to swap in this +funnel. + +OK, so how long does it take +for us to read all the stuff in + +a J funnel and one block per +input buffer? + +That's what it would take to +get started. + +So, this is swapping in a J +funnel, which means reading the + +J funnel in its entirety, +and reading one block per input + +buffer. +OK, the cost of the swap in is + +pretty natural. +The size of the buffer divided + +by B, because that's just sort +of a linear scan to read it in, + +and we need to read one block +per buffer. + +These buffers could be all over +the place because they're pretty + +big. +So, let's say we pay one memory + +transfer for each input buffer +just to get started to read the + +first block. +OK, the claim is, + +and here we need to do some +more arithmetic. + +This is, at most, +J^3 over B. + +OK, why is it, +at most, J^3 over B? + +Well, this was the first level +at which things fit in cache. + +That means the next level +bigger, which is J^2, + +which has size J^4, +should be bigger than cache. + +Otherwise we would have stopped +then. + +OK, so this is just more +arithmetic. + +You can either believe me or +follow the arithmetic. + +We know that J^4 is at least M. +So, this means that, + +and we know that M is at least +B^2. + +Therefore, J^2, +instead of J^4, + +we take the square root of both +sides, J^2 is at least B. + +OK, so certainly J^2 over B is +at most J^3 over B. + +But also J is at most J^3 over +B because J^2 is at least B. + +Hopefully that should be clear. +That's just algebra. + +OK, so we're not going to use +this bound because that's kind + +of complicated. +We're just going to say, + +well, it causes J^3 over B to +get swapped in. + +Now, why is J^3 over B a good +thing? + +Because we know the total size +of inputs to the J funnel is + +J^3. +So, to read all of the inputs + +to the J funnel takes J^3 over +B. + +So, this is really just a +linear extra cost to get the + +whole thing swapped in. +It sounds good. + +To do the merging would also +cost J^3 over B. + +So, the swap-in causes J^3 over +B to merge all these J^3 + +elements. +If they were all there in the + +inputs, it would take J^3 over B +because once everything is + +there, you're merging at full +speed, one per B items per + +memory transfer on average. +OK, the problem is you're going + +to swap out, which you may have +imagined. + +As soon as one of your input +buffers empties, + +let's say this one's almost +gone, as soon as it empties, + +you're going to totally +obliterate that funnel and swap + +in this one in order to merge +all the stuff there, + +and fill this buffer back up. +This is where the amortization + +comes in. +And this is where the log + +factor comes in because so far +it we've basically paid a linear + +cost. +We are almost done. + +So, we charge, +sorry, I'm jumping ahead of + +myself. +So, when an input buffer + +empties, we swap out. +And we recursively fill that + +buffer. +OK, I'm going to assume that + +there is absolutely no reuse, +that is recursive filling + +completely swapped everything +out and I have to start from + +scratch for this funnel. +So, when that happens, + +I feel this buffer, +and then I come back and I say, + +well, I go swap it back in. +So when the recursive call + +finishes, I swap back in. +OK, so I recursively fill, + +and then I swap back in. +And, at the swapping back in + +costs J^3 over B. +I'm going to charge that cost + +to the elements that just got +filled. + +So this is an amortized +charging argument. + +How many are there? +It's the only question. + +It turns out, +things are really good, + +like here, for the square root +of K funnel, we have each buffer + +has size K to the three halves. +OK, so this is a bit + +complicated. +But I claim that the number of + +elements here that fill the +buffer is J^3. + +So, if you have a J funnel, +each of the input buffers has + +size J^3. +It should be correct if you + +work it out. +So, we're charging this J^3 + +over B cost to J^3 elements, +which sounds like you're + +charging, essentially, +one over B to each element. + +Sounds great. +That means that, + +so you're thinking overall, +I mean, there are N elements, + +and to each one you charge a +one over B cost. + +That sounds like the total +running time is N over B. + +It's a bit too fast for +sorting. + +We lost the log factor. +So, what's going on is that + +we're actually charging to one +element more than once. + +And, this is something that we +don't normally do, + +never done it in this class, +but you can do it as long as + +you bound that the number of +times you charge. + +OK, and wherever you do a +charging argument, + +you say, well, +this doesn't happen too many + +times because whenever this +happens, this happens. + +You should say, +you should prove that the thing + +that you're charging to, +Ito charged to that think very + +many times. +So here, I have a quantifiable + +thing that I'm charging to: +elements. + +So, I'm saying that for each +element that happened to come + +into this buffer, +I'm going to charge it a one + +over B cost. +How many times does one element + +get charged? +Well, each time it gets charged + +to, it's moved into a new +buffer. + +How many buffers could it move +through? + +Well, it's just going up all +the time. + +Merging always goes up. +So, we start here and you go to + +the next buffer, +and you go to the next buffer. + +The number of buffers you visit +is the right log, + +it turns out. +I don't know which log that is. + +So, the number of charges of a +one over B cost to each element + +is the number of buffers it +visits, and that's a log factor. + +That's where we get an extra +log factor on the running time. + +It is, this is the number of +levels of J funnels that you can + +visit. +So, it's log K divided by log + +J, if I got it right. +OK, and we're almost done. + +Let's wrap up a bit. +Just a little bit more + +arithmetic, unfortunately. +So, log K over log J. + +Now, J^2 is like M, +roughly. + +It might be square root of M. +But, log J is basically log M. + +There's some constants there. +So, the number of charges here + +is theta, log K over log M. +So, now this is a bit, + +we haven't seen this in +amortization necessarily, + +but we just need to count up +total amount of charging. + +All work gets charged to +somebody, except we didn't + +charge the very initial swapping +in to everybody. + +But, every time we do some +swapping in, we charge it to + +someone. +So, how many times does + +everything it charged? +Well, there are N elements. + +Each gets charged to a one over +B cost, and the number of times + +it gets charged is its log K +over log M. + +So therefore, +the total cost is number of + +elements times a one over B +times this log thing. + +OK, it's actually plus K. +We forgot about a plus K, + +but that's just to get started +in the very beginning, + +and start on all of the input +lists. + +OK, this is an amortization +analysis to prove this bound. + +Sorry, what was N here? +I assumed that I started out + +with K cubed elements at the +bottom. + +The total number of elements in +the bottom was K^3 theta. + +OK, so I should have written +K^3 not M. + +This should be almost the same +as this, OK, but not quite. + +This is log based M of K, +and if you do a little bit of + +arithmetic, this should be K^3 +over B times log base M over B + +of K over B plus K. +That's what I want to prove. + +Actually there's a K^3 here +instead of a K, + +but that's just a factor of +three. + +And this follows because we +assume we are not in the base + +case. +So, K is at least M, + +which is at least B^2, +and therefore K over B is omega + +square root of K. +OK, so K over B is basically + +the same as K when you put it in +a log. + +So here we have log base M. +I turned it into log base M + +over B. +That's even worse. + +It doesn't matter. +And, I have log of K. + +I replaced it with K over B, +but K over B is basically + +square root of K. +So in a log, + +that's just a factor of a half. +So that concludes the analysis + +of the funnel. +We get this crazy running time, + +which is basically sorting +bound plus a little bit. + +We plug that into our funnel +sort, and we get, + +magically, optimal cache +oblivious sorting just in time. + +Tuesday is the final. +The final is more in the style + +of quiz one, so not too much +creativity, mostly mastery of + +material. +It covers everything. + +You don't have to worry about +the details of funnel sort, + +but everything else. +So it's like quiz one but for + +the entire class. +It's three hours long, + +and good luck. +It's been a pleasure having + +you, all the students. +I'm sure Charles agrees, + +so thanks everyone. +It was a lot of fun. \ No newline at end of file